Review Topics

Question 1

Tay-Sachs disease is due to a deficiency of _________, leading to accumulation of __________

Answer 1

Hexosaminidase A; GM2 ganglioside

Question 2

In the case of gas gangrene caused an organism that when cultured on blood agar shows a double zone of hemolysis, the causative organism is most likely ____________, which possesses ______ as a virulence factor responsible for erythema, necrosis, warmth, crepitus, and strong odor associated with the wound

Answer 2

Clostridium perfringens; alpha toxin

[MOA of alpha toxin is lysis of phospholipids]

Question 3

What amino acid is essential in the diet of a patient with phenylketonuria?

Answer 3

Tyrosine

[treatment of PKU includes elimination of phenylalanine from the diet and supplementation of tyrosine because pts are no longer able to synthesize tyrosine]

Question 4

A mutation in the DNA mismatch repair system leads to increased risk of __________

Answer 4

Colon cancer

[Hereditary nonpolyposis colorectal cancer (HNCC)]

Question 5

Karyotype of a partial mole vs. complete mole

Answer 5

Partial mole = 69,XXY or 69, XXX

Complete mole = 46, XX or 46 XY

Question 6

Vitamin that is an essential component of coenzyme A

Answer 6

Pantothenate (Vit B5)

Question 7

______ = bacteriophage mediated transfer of genetic material between 2 prokaryotes

Answer 7

Transduction

Question 8

Morphology of HPV

Answer 8

Non-enveloped double-stranded circular DNA virus

Question 9

Increased intracranial pressure, dry skin, alopecia, sore throat, and hepatomegaly are symptoms of vitamin _____ excess

Answer 9

Vitamin A (retinol)

Question 10

Vitamin B12 deficiency can cause a macrocytic anemia. Lab results show increased _____ and _____

Answer 10

Homocysteine; methylmalonyl coA

Question 11

Actinomyces israelii causes extensive fibrosis and eventually a lumpy jaw with a wooden consistency during its chronic phase. Describe the growth of this organism during the chronic phase

Answer 11

Forms communicating sinus tracts that release sulfur granules

Question 12

Teratogenic antiseizure drug that interferes with folate absorption in the GI tract leading to potential neural tube defects

Answer 12

Valproic acid

Question 13

Oral medication for MRSA and its MOA

Answer 13

Linezolid

Binds 23s RNA and interacts with the bacterial initiation complex

Question 14

MOA of mirtazapine

Answer 14

Alpha-2 antagonist

Question 15

Acute colonic pseudo-obstruction with signs, symptoms, and radiographic appearance of a large bowel obstruction, but with no mechanical cause of obstruction; commonly seen in elderly males after major surgery

Answer 15

Ogilvie’s syndrome

[management = correction of underlying condition, anticholinesterases, and colonic decompression]

Question 16

IV medication used to decrease intracranial pressure in the setting of diffuse intracerebral hemorrhage; works through inhibition of the sodium channels and water reabsorption at the proximal tubule as well as both parts of the loop of henle

Answer 16

IV mannitol

[pulls water via osmosis from tissues such as cerebral parenchyma into the blood and then into the urine where it can be eliminated, resulting in a decreased intracerebral pressure]

Question 17

Erb-Duchenne palsy clinical features and etiology

Answer 17

Etiology = damage to C5 and C6 nerve roots

Clinical features = paralysis of abductors, lateral rotators, and biceps brachii —> arm is pronated and medially rotated

Question 18

Mechanism of resistance to methicillin in MRSA

Answer 18

Methicillin resistance in S.aureus is encoded by the mecA gene, which encodes the enzyme PBP2a, an ALTERED PENICILLIN BINDING PROTEIN that has reduced affinity for beta-lactam antibiotics

Question 19

A popliteal artery aneurysm may cause symptoms due to a mass effect on other structures that lie in the popliteal fossa, such as the popliteal vein and the tibial nerve. If the tibial nerve is damaged, what 2 motor and 2 sensory areas would be affected?

Answer 19

Plantar flexion
Foot inversion

Sensation along posterior calf and sole of the foot

Question 20

4 classical clinical features of minimal change disease (most common cause of childhood nephrotic syndrome)

Answer 20

1. Nephrotic range proteinuria (>50mg/kg/day or 4+)
2. Hypoalbuminemia (<30g/L)
3. Edema
4. Hyperlipidemia

Question 21

Biochemical process affected by G6PD deficiency

Answer 21

Fatty acid synthesis

Question 22

MOA of bacillus anthracis toxin

Answer 22

Anthrax edema toxin is an adenylate cyclase that increases intracellular cAMP

Question 23

Anthrax edema toxin is an adenylate cyclase that increases intracellular cAMP. What 2 other bacteria have a toxin that is most similar?

Answer 23

Bordetella pertussis
Vibrio cholerae

[MOA of their toxin is to activate adenylate cyclase]

Question 24

MOA of toxin associated with Corynebacterium diphtheria and Pseudomonas aeruginosa

Answer 24

ADP-ribosylation of EF-2

Question 25

MOA of toxin associated with C.botulinum

Answer 25

Inhibits release of ACh at synaptic vesicles

Question 26

MOA of toxin associated with C.tetani

Answer 26

Inhibits release of GABA and glycine

Question 27

What 2 bacteria have a toxin that inhibits protein synthesis by degrading ribosome subunit 60S?

Answer 27

Shigella dysenteriae E.coli O157:H7

Question 28

MOA of the 2 toxins associated with S.aureus

Answer 28

Alpha toxin forms holes in membrane Beta toxin degrades sphingomyelin

Question 29

________ is administered with chemotherapeutic agent Doxorubicin to prevent the worrisome side effect of _________

Answer 29

Dexrazoxane; cardiotoxicity [can cause CHF, dilated cardiomyopathy, and death in dose-dependent manner]

Question 30

In the setting of carcinoid syndrome, patients are at risk of what vitamin deficiency?

Answer 30

Vitamin B3 (niacin) [this is because tryptophan (precursor to both niacin and serotonin) is shunted to serotonin synthesis, thus leading to a niacin deficiency]

Question 31

Tapeworm that causes cysts in organs, especially the liver (hydatid disease)

Answer 31

Echinococcus granulosus

Question 32

Dopamine agonists, such as __________ and ________, inhibit prolactin secretion and cause shrinkage of prolactin-producing adenomas

Answer 32

Cabergoline; bromocriptine

Question 33

The presence of _______ and _______ in the urine are indicative of lead poisoning

Answer 33

Coproporphyrin; d-aminolevulinic acid [this is because ingested lead interferes with heme synthesis by blocking both ferrochelatase and aminolevulinic acid dehydratase]

Question 34

_______ is a MAO-B inhibitor utilized in parkinsons that slows the metabolism of levodopa, enhancing its effect, but can increase side effects caused by levodopa

Answer 34

Selegiline

Question 35

Irinotecan has been used either as monotherapy or in conjunction with 5-FU with or without leucovorin for treatment of advanced colorectal cancer. What is the MOA of irinotecan?

Answer 35

Inhibition of topoisomerase I

Question 36

A primary lesion in left temporal lobe would cause what pattern of visual loss?

Answer 36

Right upper quadrantic anopia

Question 37

Gaucher’s disease is due to a deficiency of ____________, leading to an accumulation of __________. Pts can have hepatosplenomegaly, anemia, thrombocytopenia, osteopenia, and avascular necrosis. Gaucher’s cells are macrophages with lipid accumulation that give appearance of wrinkled paper

Answer 37

Beta-glucocerebrosidase; glucocerebroside

Question 38

Krabbe’s disease is caused by a deficiency of ______, leading to elevated levels of ________. Pts present with peripheral neuropathy, atrophy of the optic nerve, and developmental delay

Answer 38

Galactocerebrosidase; galactocerebroside

Question 39

The long thoracic n. innervates the serratus anterior m. and may be injured during a mastectomy. PE findings generally include “winging” of the scapula and difficulty with what action?

Answer 39

Abduction of the arm past 90 degrees

Question 40

First line treatment for Giardia infection

Answer 40

Metronidazole [can cause disulfuram reaction with alcohol; other drugs that do this include griseofulvin (antifungal), some of the cephalosporins, and sulfonylureas]

Question 41

Side effect most commonly seen with medication used to treat mucormycosis (caused by Mucor, Rhizopus, or Absidia)

Answer 41

Nephrotoxicity [caused by Amphotericin B; other adverse effects include infusion reaction (fever, chills, and myalgias)]

Question 42

Pain and inability to rotate the shoulder medially indicate injury to what rotator cuff muscle?

Answer 42

Subscapularis [subscapularis also does adduction]

Question 43

Nephritic syndrome that presents as hematuria (gross or microscopic) discovered within 1-3 days of an upper respiratory or gastrointestinal infection

Answer 43

IgA nephropathy (aka Berger’s disease) [Note: key difference with acute poststreptococcal glomerulonephritis (another nephritic syndrome associated with hematuria following a URI) is TIMING. While Berger’s disease has hematuria within 1-3 days of URI, acute PSGN has hematuria 1-3 weeks after URI. Acute PSGN also appears as “lumpy bumpy” on light microscopy with low C3 levels]

Question 44

_______ is an autosomal recessive genetic disorder that leads to hexagonal-shaped crystals in the urine, often causing bilateral renal stones at an early age. Treatment includes ______, which alkalizes the urine, thereby preventing precipitation of these crystals

Answer 44

Cystinuria; acetazolamide

Question 45

Most likely location for aspirated foreign bodies while pt is upright/seated vs. supine

Answer 45

Seated = posterobasal segment of right lower lobe Supine = superior segment of right lower lobe

Question 46

What cells release CCK?

Answer 46

I cells

Question 47

____ cells release somatostatin hormone, responsible for decreasing gastric acid and pepsinogen secretion, pancreatic and small intestine fluid secretion, gallbladder contraction, and insulin and glucagon release

Answer 47

D

Question 48

_____ cells are located in the antrum of the stomach and release gastrin, which is responsible for increasing ______ secretion, growth of gastric mucosa, and gastric motility

Answer 48

G; gastric H+

Question 49

S cells are responsible for releasing ______ in response to increased levels of acid in the lumen of the duodenum; other functions include increasing bicarbonate and bile secretion, as well as decreasing gastric acid secretion

Answer 49

Secretin

Question 50

How is renal reabsorption rate of a substance calculated?

Answer 50

Reabsorption rate = (Filtered Load) - (Excretion) Filtered load = GFR x plasma concentration Excretion = urine flow rate x urine concentration

Question 51

What autonomic receptors are considered Gs-linked?

Answer 51

``` Beta 1 Beta 2 D1 H2 V2 ``` [alpha 1, M1, and M3 are Gq-linked. D2 and M2 are Gi-linked]

Question 52

What are 3 options for prophylactic treatment for mycobacterium infections?

Answer 52

Isoniazid Azithromycin Clarithromycin

Question 53

_______ is used for moderate-to-severe persistent asthma in pts who react to perennial allergens wherein symptoms are not controlled by inhaled corticosteroids

Answer 53

Omalizumab

Question 54

Most common helminthic infection worldwide; usually asymptomatic, but some patients present with pulmonary and GI complaints. Stool microscopy shows characteristic thick shelled parasitic eggs.

Answer 54

Ascaris lumbricoides [nematode/roundworm]

Question 55

Cold agglutinin disease is an autoimmune disease characterized by the presence of high concentrations of circulating _____ antibodies directed against RBCs. Patients will have low levels of circulating _____ due to consumption of that protein

Answer 55

IgM; C3b [Note: IgG is associated with warm agglutinins]

Question 56

______ poisoning inhibits the ETC in the mitochondria, inhibiting ATP production via oxidative phosphorylation. Exposure can lead to altered mental status, new onset seizures, hepatic failure, and rhabdomyolysis leading to renal failure. Early in the course, pts have flushed skin with tachycardia, tachypnea, and HTN. Later, pts may have cyanosis, bradycardia, bradypnea, and hypotension. Treatment involvees IV administration of either a mixture of sodium nitrite and sodium thiosulfate, or hydroxocobalamin

Answer 56

Cyanide

Question 57

Parasitic infection with clinical manifestations including periorbital swelling, myalgia, and myositis involving facial and neck muscles, conjuntival hemorrhage, and splinter hemorrhages. Muscle biopsy will show encysted larvae.

Answer 57

Trichinella spiralis

Question 58

Interferon-alfa combined with ribavirin and a NS3/4A protease inhibitor is occasionally used to treat chronic hepatitis C if other drugs are not available. What are the 3 major side effects of this treatment?

Answer 58

Flu-like symptoms Neutropenia Depression

Question 59

Where is the right mainstem bronchus in relation to the right pulmonary artery?

Answer 59

Posterior [mnemonic RALS to remember positions of pulmonary arteries in relation to their respective bronchi: Right pulmonary a. is Anterior, Left pulmonary a. is Superior]

Question 60

How is renal potassium metabolism altered in the case of respiratory acidosis?

Answer 60

Potassium secretion in the distal tubules is decreased [explanation: High concentrations of H+ in the ECF cause H+ to enter cells in exchange for K+. This reduces the intracellular K+ concentration, resulting in hyperkalemia. Secretion in the distal tubules is reduced by any factor that reduces the intracellular K+ concentration]

Question 61

T/F: anabolic steroid use may lead to prostatic hyperplasia

Answer 61

True [the prostate is a testosterone dependent gland and may increase in size due to steroid’s androgenic effects]

Question 62

Four basic factors that cause a right-shift of oxygen-hemoglobin dissociation curve

Answer 62

Decrease in pH Increase in 2,3-BPG Increase in PCO2 Increase in temperature

Question 63

Parkinsonian features, visual hallucinations, and waxing/waning mental status are characteristic of what type of dementia?

Answer 63

Lewy body dementia

Question 64

Hematuria, mild proteinuria, fever, eosinophilia, nausea, vomiting, and rash are all features of __________________, which can occur within a few days of administration of an offending agent such as penicillin.

Answer 64

Acute interstitial nephritis [Note: difference in acute tubular necrosis is that there are muddy brown casts in the urine and eosinophilia is not a feature]

Question 65

______________ is a paraneoplastic syndrome characterized by development of antibodies to presynaptic voltage gated calcium channels, leading to decreased release of ACh at the NMJ. Pts present with symmetric muscle weakness, most prominently in the proximal muscles of the lower extremities. It is associated with __________ cancer, so a ________ should be included in the workup

Answer 65

Lambert-Eaton Syndrome; Small cell lung cancer; CXR

Question 66

___________ media is the culture media of choice for growth of Neisseria gonorrhea. It contains _____ to inhibit gram-positive bacterial growth, _______ to inhibit gram-negatives other than Neisseria, and ______ to inhibit fungal growth

Answer 66

Thayer-Martin Vancomycin; Polymyxin; Nystatin [Thayer-Martin = VPN media]

Question 67

Vitamin B1 is essential for the synthesis of thiamine pyrophosphate (TPP), which is an active carrier of aldehydes and enzymes use it to transfer aldehydes to another molecule during the reaction. The enzyme ______ is involved in the hexose monophosphate shunt and uses TPP as its sole cofactor

Answer 67

Transketolase

Question 68

During which phase of bacterial growth does spore formation begin — lag phase, log phase, stationary phase, or death phase?

Answer 68

Stationary phase [Lag phase = metabolic activity w/o division; log phase = rapid cell division; death phase = period of prolonged nutrient depletion and buildup of metabolic waste products leading to death]

Question 69

Breakdown products of disaccharides lactose, sucrose, and maltose

Answer 69

Lactose = Glucose + Galactose Sucrose = Glucose + Fructose Maltose = Glucose + Glucose

Question 70

Head lice is typically treated with topical _______. However, resistance to topical medications has grown. When resistance occurs, systemic treatment may be initiated, and ______ is the best option

Answer 70

Permethrin; ivermectin

Question 71

N.meningitidis is a gram-negative diplococci that has a _______ capsule and ferments ______ and ______

Answer 71

Polysaccharide; glucose; maltose

Question 72

3 features of irreversible cell injury

Answer 72

Severe membrane damage Calcium influx Release of intracellular enzymes (i.e., lysosomal rupture)

Question 73

3 treatment options for heparin-induced thrombocytopenia (HIT) upon discontinuation of heparin

Answer 73

Lepirudin Argatroban Fondaparinux [Lepirudin and Argatroban are direct thrombin inhibitors, and Fondaparinux catalyzes the pt’s endogenous antithrombin to inhibit factor X (indirect factor X inhibitor)]

Question 74

How do functional residual capacity (FRC), vital capacity, and total lung capacity (TLC) change in interstitial lung disease?

Answer 74

All decrease

Question 75

Are acetyl-CoA carboxylase, arginase I, and PEP carboxykinase enzymes found in the mitochondria or the cytosol?

Answer 75

Cytosol

Question 76

Are citrate synthase, carbamoyl phosphate synthetase I, and pyruvate carboxylase found in the mitochondria or the cytosol?

Answer 76

Mitochondria

Question 77

When treating a patient with pheochromocytoma for hypertension, phenoxybenzamine may be used. What is the MOA?

Answer 77

Irreversible alpha adrenergic antagonist

Question 78

Biliary complication associated with ulcerative colitis

Answer 78

Primary Sclerosing Cholangitis [Causes inflammation, fibrosis, and stricturing of medium and large-sized ducts in the intrahepatic and extrahepatic biliary tree. Clinically presents with fatigue and pruritis. Histology shows fibrous obliteration of epithelium and CT replacement in an onion-skin pattern]

Question 79

Tumor marker for pancreatic cancer

Answer 79

CA 19-9

Question 80

Tumor marker for colon cancer

Answer 80

CEA

Question 81

Nontender testicular mass, elevated serum placental alkaline phosphatase, sheets of relatively uniform tumor cells with prominent nucleoli and clear cytoplasm — What type of tumor?

Answer 81

Seminoma

Question 82

Wilson disease can affect the kidneys leading to what complication and subsequent electrolyte abnormality?

Answer 82

Renal tubular acidosis type II Results in hypokalemic, hyperchloremic nonanion gap metabolic acidosis

Question 83

Diabetic cataracts are an end-organ consequence of uncontrolled DM. Glucose can enter cells via facilitated glucose transporters of GLUT family. Once in the cell it can be phosphorylated to glucose-6-phosphate by either glucokinase or hexokinase. Glucose-6-phosphate cannot leave the cell and can enter glycolysis. In the lens, nerve, and kidney cells glucose can also be converted to _________, a reaction accomplished by the enzyme _______ ______ using cofactor NADPH.

Answer 83

Sorbitol; aldose reductase

Question 84

2 primary treatment options for bacterial vaginosis due to Gardnerella vaginalis infection

Answer 84

Metronidazole Clindamycin

Question 85

Acid-base disturbance caused by hyperventilation

Answer 85

Respiratory alkalosis

Question 86

T/F: the membrane potential of the postsynaptic membrane does not change as a result of rocuronium for anesthesia induction

Answer 86

True — Rocuronium is a non-depolarizing muscle relaxant that acts as a competitive antagonist at the NMJ causing muscle paralysis without membrane depolarization

Question 87

MOA of Metformin

Answer 87

Decreases hepatic glucose production by inhibition of liver gluconeogenesis [can also decrease intestinal glucose absorption and increase insulin sensitivity]

Question 88

Where is intrinsic factor produced?

Answer 88

Parietal cells within the gastric mucosa

Question 89

CML is most commonly associated with a _______ translocation, usually resulting in the ______ fusion gene, which leads to constitutional activation of ________ _______ activity

Answer 89

t(9;22); BCR-ABL; Tyrosine kinase

Question 90

Treatment agent of choice for CML

Answer 90

Imatinib (tyrosine kinase inhibitor) [this is because BCR-ABL fusion gene leads to constitutive activity of a tyrosine kinase!!]

Question 91

Self-limited hypothyroidism that is typically seen following a viral, flu-like illness. Initially presents as transient hyperthyroidism as well as tender, enlarged thyroid gland with referred jaw pain

Answer 91

de Quervain thyroiditis

Question 92

Spinal cord somatosensory pathway that conveys light touch, vibration, and proprioception

Answer 92

Posterior column

Question 93

Spinal cord somatosensory pathway that conveys pain, temperature, and crude touch

Answer 93

Spinothalamic tract

Question 94

The de novo synthesis of pyrimidines relies on the enzymatic conversion of orotic acid to _______ ________

Answer 94

Uridine monophosphate

Question 95

In ________ palsy, pts have paralysis of the ipsilateral hand and Horner’s syndrome on the ipsilateral face. This is due to damage to _____ and _____ nerve roots

Answer 95

Klumpke; C8, T1

Question 96

Cori’s disease is an inherited glycogen storage disease caused by a deficiency of __________, an enzyme responsible for debranching of glycogen during glycogenolysis. While not the most severe glycogen storage disease, pts still experience fasting hypoglycemia due to inability to use stored glycogen. As a result, gluconeogenesis is upregulated. The regulation of gluconeogenesis occurs at several key steps, but only ________ serves as an allosteric activator. This allosteric activation occurs with the reaction catalyzed by pyruvate carboxylase, which converts pyruvate to OAA. This reaction also requires ______ as a source of energy, and _____ as a cofactor, but these are not allosteric regulators of the enzyme.

Answer 96

Alpha 1,6-glucosidase Acetyl-CoA ATP; Biotin

Question 97

Croup may present on X ray with narrowing of the trachea d/t inflammation, called “steeple sign”. What is the most common cause of croup?

Answer 97

Parainfluenza virus

Question 98

Which of the following is not found in the outpouching of tissue associated with a Zenker’s diverticulum? ``` A. Lamina propria B. Muscularis mucosa C. Muscularis propria D. Submucosa E. This is a true diverticulum and contains all of the above layers ```

Answer 98

C. Muscularis propria [Zenker’s diverticulum is a pseudodiverticulum, so it does not contain all mucosal tissue layers. It has mucosal and submucosal tissue, but not the muscularis propria]

Question 99

Mitochondrial disorder that causes painless progressive loss of central vision. Other clinical manifestations include dystonia, pseudobulbar palsy, intellectual deterioration, and muscle weakness. Many patients also have Wolff-Parkinson-White syndrome.

Answer 99

Leber hereditary optic neuropathy [Caused by mtDNA mutations that encode subunits of ETC complex I. Biopsy shows loss of retinal ganglion cells and degeneration of papillomacular bundle]

Question 100

Dobutamine may be used to enhance contractile ability of the heart in pts with CHF exacerbation. It exerts its effect primarily on _____ receptors, which are GPCRs of the ______ subtype.

Answer 100

Beta-1; Gs

Question 101

__________ presents in infancy with symptoms of lethargy, vomiting, jaundice, hepatomegaly, and bilateral cataracts while taking breast milk

Answer 101

Galactosemia [deficiency in galactose-1-phosphate uridyltransferase]

Question 102

Disease and enzyme deficiency associated with the following clinical presentation: 11 year old girl of Ashkenazi Jewish descent presenting with hepatosplenomegaly, anemia, thrombocytopenia, osteopenia, and avascular necrosis

Answer 102

Gaucher’s diease Deficiency of beta-glucocerebrosidase [note: diagnostic histologic finding = lipid-filled macrophages with wrinkled-paper appearance]

Question 103

What effect do competitive inhibitors have on Km and Vmax?

Answer 103

Km increases Vmax stays the same

Question 104

Which of the following inhibits microtubule depolymerization? ``` A. 6-mercaptopurine B. Vincristine C. Cyclophosphamide D. Cisplatin E. Paclitaxel ```

Answer 104

E. Paclitaxel [note: vincristine inhibits microtubule POLYMERIZATION while paclitaxel inhibits microtubule DEPOLYMERIZATION]

Question 105

The urea cycle is the pathway responsible for synthesis of what amino acid?

Answer 105

Arginine

Question 106

Vertebral levels at which the celiac trunk, SMA, and gonadal artery arise from the abdominal aorta

Answer 106

Celiac trunk = T12 SMA = L1 Gonadal = L2

Question 107

The inferior mesenteric artery arises from the abdominal aorta at vertebral level _______. The bifurcation of the aorta occurs at vertebral level ______.

Answer 107

L3; L4

Question 108

Embryonic origin of prostate gland

Answer 108

Urogenital sinus

Question 109

Brugada syndrome is a condition associated with a high risk of _____ _______ _____ in young adults

Answer 109

Sudden cardiac death

Question 110

______ ______ presents on ECG as persistent ST elevations in leads V1-V3 with RBBB +/- terminal S waves in lateral leads (associated with typical RBBB); may also see prolongation of PR interval

Answer 110

Brugada syndrome [Note: Pts with Brugada syndrome may present with normal ECGs, with abnormalities appearing when pt has a fever, takes a Na-channel blocker, takes a TCA, or uses cocaine. Adrenergic stimulating decreases the ST elevation, while vagal stimulation worsens it]

Question 111

__________ testicular tumors present in early childhood and secrete alpha-fetoprotein, but not hCG. They have a number of morphologic variants, but ___________ are diagnostic for these tumors, resembling primitive glomeruli

Answer 111

Yolk sac; Schiller-Duvall

Question 112

What is the only apolipoprotein associated with LDL, binding LDL receptor on the liver?

Answer 112

Apolipoprotein B-100

Question 113

Most abundant amino acid in collagen

Answer 113

Glycine

Question 114

_______ ______ occurs due to deficiency of acid maltase. Thus, glycogen accumulates in lysosomes and cytoplasm, leading to cardiomyopathy, hypotonia, and hepatomegaly. Pts may present in the first few months of life or later in adulthood. When presenting in infancy, children commonly have respiratory distress, difficulty with feeds, and cardiomegaly

Answer 114

Pompe’s disease

Question 115

Nitroprusside is a potent arterio- and venodilator indicated when rapid reduction of blood pressure is desired, as in the case of malignant hypertension. However, nitroprusside is converted to ______ in the bloodstream, and thus has the potential to cause toxicity, particularly in the setting of prolonged exposure.

Answer 115

Cyanide

Question 116

3 serious adverse reactions that need to be monitored for in patients taking methimazole (antithyroid medication)

Answer 116

Agranulocytosis Aplastic anemia Hepatotoxicity

Question 117

Benztropine is an _______ medication that is used to decrease the resting tremor and rigidity associated with Parkinson’s disease. It does not have any impact on bradykinesia.

Answer 117

Anticholinergic

Question 118

Most common site of renal stone obstruction in children

Answer 118

Ureteropelvic junction

Question 119

Abciximab functions by inhibiting a platelet integrin called ___________. This is the same molecule is defective in _______ _________ (disease)

Answer 119

GP IIb/IIIa Glanzmann Thrombasthenia

Question 120

How does emphysema affect compliance and FRC?

Answer 120

Both are increased

Question 121

What is Conn Syndrome?

Answer 121

Primary aldosteronism caused by hyperaldosteronism originating in the adrenal gland Characterized by HTN secondary to sodium retention, hypokalemia, and decreased renin secretion due to negative feedback of increased BP on renin secretion

Question 122

Congenital condition affecting capillaries leading to port-wine stain, leptomeningeal angioma, seizures, glaucoma, and mental retardation

Answer 122

Sturge-Weber syndrome

Question 123

The ganglionic destruction in achalasia begins with irreversible of the esophageal myenteric neruons, ultimately leading to fibrosis and scarring of Auerbach’s plexus. In particular, the neurons destroyed are important in secretion of ______ ______, thus secretion of this substance is decreased in achalasia

Answer 123

Nitric oxide

Question 124

Which class of anti-asthma drugs exhibits hepatotoxicity?

Answer 124

Antileukotrienes (e.g., Zileuton)

Question 125

A lesion in the ______ ______ will lead to a right or left upper quadrantic anopia

Answer 125

Temporal lobe

Question 126

Anticoagulant treatment for atrial fibrillation that does not require monitoring through routine blood draws

Answer 126

Dabigatran (direct thrombin inhibitor)

Question 127

Inheritance of Marfan syndrome

Answer 127

Autosomal dominant

Question 128

Is the IVC intraperitoneal or retroperitoneal?

Answer 128

Retroperitoneal

Question 129

Is the pancreas intraperitoneal or retroperitoneal?

Answer 129

The head, neck, and body are retroperitoneal The tail is intraperitoneal (located in splenorenal ligament)

Question 130

Of the 4-drug regimen used to treat mycobacterium tuberculosis infection, _________ frequently produces visual problems due to retrobulbar neuritis, including laack of acuity and color blindness. The mechanism of action of this medication is to inhibit _______ _______, interfering with the mycobacterial cell wall

Answer 130

Ethambutol; arabinosyl transferase

Question 131

3 types of antibody associated with antiphospholipid antibody syndrome

Answer 131

Lupus anticoagulant Anti-cardiolipin Anti-beta2-glycoprotein

Question 132

Lesions within the ______ ______ cause contralateral hemiballismus

Answer 132

Subthalamic nucleus

Question 133

MOA of heparin

Answer 133

Potentiates pt’s endogenous antithrombin [thus inactivating thrombin and factor Xa]

Question 134

What causes impaired vision in the case of giant cell arteritis?

Answer 134

Occlusion of the ophthalmic artery

Question 135

Triad associated with Plummer Vinson syndrome

Answer 135

Esophageal webs Glossitis Iron deficiency anemia

Question 136

Pyruvate kinase is responsible for conversion of phosphoenolpyruvate to pyruvate, a reaction that produces 2 ATP molecules. Without functioning enzymes (e.g., Pyruvate Kinase Deficiency), phosphoenolpyruvate builds up and is shunted to an alternative pathway, generating ________________ which results in increased tendency for hemoglobin to release oxygen

Answer 136

2,3-bisphosphoglycerate (2,3-BPG)

Question 137

________ is a chemotherapeutic that may cause myelosuppression due to inhibition of thymidylate synthase. The rescue for this myelosuppression is _______

Answer 137

5-FU; thymidine

Question 138

The head of the pancreas is supplied by the __________ artery, which is a primary branch of the _______ ______ artery

Answer 138

Pancreaticoduodenal; superior mesenteric

Question 139

Nerve roots associated with radial nerve

Answer 139

C5, C6, C7, C8, T1

Question 140

Apolipoprotein B-48 is found in ______ and helps facilitate their secretion

Answer 140

Chylomicrons

Question 141

Hydralazine may increase the risk of drug-induced lupus, which presents with myalgias, arthralgias, and red scaly rash. What genetic abnormality may predispose pts to drug-induced lupus with lipid soluble drugs?

Answer 141

Polymorphisms in the genes for phase II reactions of lipid-soluble drugs — like glucuronidation, sulfurization, or acetylation

Question 142

Hereditary or acquired defect in the PCT that occurs almost exclusively in caucasian males which results in losses of glucose, sodium, phosphate, protein, and other solutes in the urine

Answer 142

Fanconi syndrome

Question 143

What complication of hyperparathyroidism is characterized by “brown tumors” that form in bone leading to increased risk of fracture; the lesions are cysts filled with blood, fibrous tissue, and osteoclasts

Answer 143

Osteitis fibrosa cystica

Question 144

The ______ ______ contains the primary motor cortex and so damage to this region would cause major motor deficits such as hemiparesis

Answer 144

Precentral gyrus

Question 145

Side effect most likely to limit patient’s ability to tolerate a fibrate for hyperlipidemia

Answer 145

Myalgia [Fibrates activate PPARs and can cause muscle damage, especially when combined with statins]

Question 146

The scleroderma variant associated with CREST syndrome has a positive ____________ antibody

Answer 146

Anti-centromere

Question 147

Depletion of ________ is responsible for the reduction of glycolysis in the setting of lactate dehydrogenase deficiency

Answer 147

NAD+ [if skeletal muscle lacks lactate dehydrogenase, NADH can not be oxidized to NAD+ and the cori cycle cannot provide the glucose input. Thus ATP production via anaerobic fermentation is reduced, ATP production drops, and muscle activity decreases]

Question 148

Yellow fever virus is a type of _________ found in the saliva of the Aedes aeqypti mosquito typically found in South America and sub-Saharan Africa. These viruses are enveloped, single-stranded, positive-sense, linear RNA viruses.

Answer 148

Flavivirus

Question 149

______ is a recognized tumor-suppressor gene and has been shown to be down-regulated in extranodal NK/T cell lymphoma. When expressed, it inhibits cell growth through activation of apoptosis as well as arrest of the cell cycle. When it is down-regulated, there is decreased apoptosis of the malignant cells

Answer 149

FOXO3

Question 150

Acute severe lead intoxication can be treated by _______ or CaNa2EDTA

Answer 150

Dimercaprol

Question 151

Drug of choice for absence seizures

Answer 151

Ethosuximide [blocks T-type Ca++ channels in the thalamus]

Question 152

Major side effects of the chemotherapeutic _________ include myelosuppression, GI upset, and hepatotoxicity. Allopurinol inhibits xanthine oxidase, the enzyme that metabolizes this drug, so concurrent allopurinol therapy increases the risk of side effects.

Answer 152

6-mercaptopurine

Question 153

________ _______ can mimic acute coronary syndrome, including ST elevation in precordial leads (V1-V4) and ballooning of the heart’s apex and midventricular hypokinesis on echocardiography, and often follows a severe physical or psychosocial stressor

Answer 153

Takotsubo cardiomyopathy

Question 154

_______, _______, and _______ all stimulate parietal cells within the stomach to produce acid to decrease the stomach’s pH

Answer 154

Histamine, Acetylcholine, and Gastrin

Question 155

What organelle are the CYP450 enzymes found in?

Answer 155

Smooth ER

Question 156

Most patients with anticholinergic toxicity can be treated with supportive care only until the effects of the drug wear off; however, ________ is indicated when one of the following is present: (1) tachydysrrhythmias with hemodynamic compromise, (2) intractable seizures, or (3) severe agitation or psychosis

Answer 156

Physostigmine

Question 157

What organ is affected most in mercury exposure?

Answer 157

Kidneys [Mercury exposure can cause membranous glomerulonephritis, leading to NEPHROTIC syndrome]

Question 158

Heme, which is synthesized from porphyrin, is dependent upon sufficient quantities of amino acid _______ for its synthesis. Deficiency would result in a non-iron deficiency anemia

Answer 158

Glycine

Question 159

To avoid chronic lactic acidosis in pyruvate dehydrogenase complex deficiency, a diet rich in what 2 amino acids is recommended?

Answer 159

Lysine Leucine [these are the 2 purely ketogenic amino acids]

Question 160

______________ artery aneurysms can lead to visual disturbances due to compression of the optic nerve

Answer 160

Anterior communicating artery

Question 161

The inability to rotate the shoulder medially indicates injury to what rotator cuff muscle?

Answer 161

Subscapularis [Infraspinatus does lateral rotation, Teres minor adducts and laterally rotates, supraspinatus helps deltoid abduct]

Question 162

What type of heart murmur would you expect in a pt with longstanding ankylosing spondylitis?

Answer 162

Aortic regurgitation (soft, high-pitched early diastolic murmur)

Question 163

Autosomal recessive enzyme deficiency in which diagnosis is established by identifying lab abnormalities, including anion gap metabolic acidosis, hypoketotic hypoglycemia, and the presence of dicarboxylic acids in the urine

Answer 163

Acyl-CoA dehydrogenase deficiency

Question 164

4 most common primary tumor sites that metastasize to the lungs

Answer 164

Colon Breast Prostate Bladder

Question 165

Typical antipsychotics primarily block the _____ receptor. Atypical antipsychotics offer a more favorable side effect profile than typical antipsychotics due to additional antagonism at the _____ receptor

Answer 165

D2; 5-HT2

Question 166

Blood supply to the proximal 1/3, middle, and distal 1/3 of the ureter

Answer 166

Proximal 1/3 = Renal a. Middle = Small branches from common iliac a. Distal 1/3 = Superior vesical a.

Question 167

In a patient with a history of transplant over 100 days ago, typical findings of _____________ include erythema, hyper/hypopigmentation, induration, atrophy, and skin thickening. Patients also complain of ocular involvement, including aqueous tear deficiency, cataracts, conjunctival hyperemia, and corneal epithelial staining. Hair and nail dystrophy can also occur. The liver is affected in about half of patients, most commonly manifesting as liver function test abnormalities

Answer 167

Chronic graft-versus-host disease

Question 168

The most commonly used prophylactic agent in the prevention of chronic graft-vs-host disease is _________. This is a potent immunosuppressive that can lead to severe renal insufficiency and hyperbilirubinemia. In patients with significant side effects, ________ can be given as a rescue regimen

Answer 168

Methotrexate; leucovorin [leucovorin is a reduced form of folic acid]

Question 169

_________ are tumors that are most commonly found within the cerebellum, arising from the vasculature. Patients may present with symptoms of cerebellar ataxia (i.e., wide based gait). Most are sporadic, but they can be seen in association with __________ syndrome, in which case there may be multiple throughout the CNS. Surgical resection is warranted because bleeding from these tumors can be fatal

Answer 169

Hemangioblastomas; VHL

Question 170

Treatment for Tourette’s syndrome

Answer 170

Atypical and typical neuroleptics, like haloperidol

Question 171

_______ _______ _______ is characterized by repetitive seizures consisting of brief, often symmetric, muscular contractions with loss of body tone causing the patient to fall or slump forward. Seizures usually occur in the morning and are precipitated by stress and sleep deprivation. ________ ______ is often used to treat these seizures

Answer 171

Juvenile myoclonic epilepsy; Valproic acid

Question 172

What characteristic of HCV leads to its high genetic heterogeneity?

Answer 172

HCV lacks RNA polymerase proofreading exonuclease

Question 173

When used in the treatment of HIV, maraviroc antagonizes the ______ receptor on white blood cells, preventing its interaction with the ______ protein of HIV.

Answer 173

CCR5; gp120

Question 174

________ ________ is due to a deficiency in galactocerebrosidase, leading to accumulation of galactocerebroside. Clinical features include peripheral neuropathy, optic atrophy, and developmental delay in infancy. ______ cells can be seen in the white matter of the CNS; these cells are macrophages clustered near blood vessels that have numerous nuclei and enlarged cytoplasm

Answer 174

Krabbe’s disease; Globoid [Krabbe’s disease = Globoid cell leukodystrophy]

Question 175

Chronic carriers of HBV infection have increased chances of malignant transformation to hepatocellular carcinoma. This develops independently of the progression to cirrhosis, so what is the mechanism of carcinogenesis?

Answer 175

HBV viral incorporation into the hepatocellular genome, leading to genomic instability

Question 176

Parasitic roundworm found in tropical climates (such as Southeast Asia) that can present with vague GI complaints as well as pulmonary and dermatologic problems. With chronic infection, dermal migration of larvae becomes apparent as serpiginous eruptions in the skin

Answer 176

Strongyloides stercoralis

Question 177

Inheritance of Hemophilia A and B

Answer 177

X-linked recessive

Question 178

Local anesthetics include the ester family (benzocaine, cocaine, procaine, and tetracaine) and the amide family (bupivacaine, lidocaine, mepivacaine, prilocaine). The local anesthetics in the _______ family are more allergenic because they are metabolized by the plasma pseudocholinesterases while _______ drugs are metabolized by the CYP450 system

Answer 178

Ester; amide

Question 179

Symptoms of chronic infection with ________ _________ (parasitic infection) are typically isolated to the heart and GI systems. In the heart, the disease can cause arrhythmias and 3rd degree BBB. Symptoms include syncope, lightheadedness, and palpitations. It can also cause CHF and stroke. In the GI tract, it typically causes achalasia and megacolon.

Answer 179

Trypanosoma cruzi (Chagas disease)

Question 180

Etiology of Rocky Mountain Spotted Fever and how this organism causes the rash

Answer 180

Rickettsia rickettsii R.rickettsii is an obligate intracellular organism that causes rash by invading vascular endothelial cells, resulting in increased vascular permeability, hypovolemia, and hypotension

Question 181

_______ cells have Reinke crystalloids (hexagonal prisms by EM) and produce testosterone in response to LH. ________ cells have Charcot-Bottcher crystalloids (bundles of microfilament) and form the blood-testis barrier

Answer 181

Leydig Sertoli

Question 182

________ are a class of drugs that increase insulin release from beta cells of the pancreas. Hypoglycemia is a prominent side effect due to possibility of overstimulation of insulin release

Answer 182

Sulfonylureas

Question 183

Amantadine was originally developed to treat ________, but recently has been used to treat Parkinson’s disease

Answer 183

Influenza

Question 184

Proteus mirabilis is a gram-negative bacterium that produces urease, which alkalinizes the urine. This can lead to what complication specific to UTI caused by this organism?

Answer 184

Alkalinization causes precipitation of magnesium ammonium phosphate crystals, which can lead to formation of struvite kidney stones

Question 185

Broca’s aphasia is typically due to a lesion located where?

Answer 185

Dominant frontal lobe, affecting the inferior frontal gyrus

Question 186

Ito cells are lipid-containing stellate cells in the liver which store ________ in the quiescent state and secrete _______ in the activated state

Answer 186

Vitamin A; collagen

Question 187

Patients with ____________ typically have circulating antinuclear and anti-smooth muscle antibodies, jaundice, hepatosplenomegaly, and elevated transaminases

Answer 187

Autoimmune hepatitis

Question 188

_______ _____ tumors lead to blockage of the aqueduct, leading to damage to CN III, CN IV, and Edinger-Westphal nucleus. As a result, pts have impaired pupillary response to light but intact accommodation. Mass effect on the superior colliculi can lead to impaired conjugate vertical gaze as well as deviation of the eyes downward. This is also known as _______ syndrome

Answer 188

Pineal gland; Parinaud’s

Question 189

The abducens nerve begins at the junction of the pons and medulla. From there, it moves anteriorly through the skull, going through the ________________ with the oculomotor nerve, trochlear nerve, opthalmic and maxillary branches of the trigeminal nerves, and the internal carotid artery. It then passes through the ____________ before innervating the lateral rectus m.

Answer 189

Cavernous sinus; superior orbital fissure

Question 190

By what mechanism do beta blockers reduce blood pressure?

Answer 190

Beta blockers inhibit release of renin from renal JG cells through antagonism of beta-1 receptors on these cells

Question 191

Niacin can be obtained through dietary intake or synthesized endogenously from _______

Answer 191

Tryptophan

Question 192

Cystic fibrosis is most commonly due to a 3-base pair deletion in the CFTR gene at amino acid position F508. How does this mutation affect CFTR?

Answer 192

This mutation IMPAIRS POST-TRANSLATIONAL PROCESSING of CFTR, resulting in shunting of CFTR toward the proteasome, with complete absence of the protein on the cell surface

Question 193

Meningeal signs, confusion, and trophozoites in the CSF raise strong suspicion for primary amebic meningoencephalitis, which is caused by ______ ______, a free-living, motile protozoan parasite that lives in warm water and soil worldwide. Exposure primarily occurs when humans inadvertently inhale the organism during recreational water activities. Most individuals do not become ill, but a minority develop fatal meningoencephalitis after the organism penetrates the olfactory mucosa, crosses the cribriform plate, and invades the olfactory bulb

Answer 193

Naegleria fowleri

Question 194

For the embryologic development of the kidney, the _____ _____ ultimately gives rise to the collecting system - including the collecting tubules and ducts, major and minor calyces, renal pelvis, and the ureters. The ______ ______ gives rise to the glomeruli, Bowman’s space, proximal tubules, loop of henle, and distal convoluted tubules

Answer 194

Ureteric bud; metanephric mesoderm (blastema)

Question 195

Heme synthesis occurs partly in the _________ and partly in the cytoplasm of erythrocytes

Answer 195

Mitochondria

Question 196

Excess ________ secretion due to a pancreatic islet cell tumor can result in watery diarrhea, hypokalemia, and achlorhydria (WDHA syndrome aka pancreatic cholera)

Answer 196

VIP [this is a VIPoma]

Question 197

A positive tuberculin skin test is characterized by significant skin induration around the injection site at 48 hours. What 2 immune effector cells are most important for control of the tuberculosis?

Answer 197

CD4 T cells Macrophages

Question 198

T/F: failed gallbladder visualization on radionuclide biliary scan is specific to acute cholecystitis

Answer 198

True — acute cholecystitis is most often caused by gallstones obstructing the cystic duct. In acute or chronic cholecystitis, the radiotracer will be taken up by the liver with progressive excretion into the common bile duct and proximal small bowel, but the gallbladder will NOT be visualized due to the obstruction

Question 199

Viruses with segmented genomes are capable of genetic shifts through reassortment. What 4 viral classes have segmented genomes?

Answer 199

Bunyavirus Orthomyxovirus Arenavirus Reovirus

Question 200

________ is a potent immunosuppressive agent that works via inhibition of calcineurin activation, resulting in decreased IL-2 production; often used in transplant pts. Serum levels should be monitored closely, and patients should be routinely checked for _____ toxicity

Answer 200

Cyclosporin; renal

Question 201

AR or X-linked disorder affecting several genes that alter a multi-protein complex required for DNA repair; Typically presents in early childhood with signs of pancytopenia in addition to congenital malformations. Short stature, cafe-au-lait spots or hypopigmentation, dysplastic thumbs, microcephaly, and hypogonadism may be seen

Answer 201

Fanconi anemia

Question 202

Malignant ovarian tumors with “fried egg” appearance, normal serum AFP, but beta-hCG and LDH are commonly elevated; frequently seen on streak gonads, which can occur in Turner’s syndrome

Answer 202

Dysgerminomas

Question 203

_________ is a zoonotic illness that is transmitted directly to humans through contact with infected animals (like veteranarians or farmers) or via ingestion of unpasteurized milk or cheese products. Symptoms include persistent, undulating fever and joint pain

Answer 203

Brucellosis

Question 204

_______ is a chemotherapeutic primarily used in NHL, breast, and ovarian cancers that carries the risk of hemorrhagic cystitis due to irritation of the bladder by its metabolite acrolein. MOA is alkylation of nitrogenous bases in nucleic acids. A few medications have been used with efficacy for preventing this damage, and each of these bind to acrolein. The most frequently used is _______, because it does not decrease the efficacy of the chemotherapeutic. Other agents used include N-acetylcysteine, amifostine, and pentosan polysulfate

Answer 204

Cyclophosphamide Mesna (2-mercaptoethanesulfonate sodium)

Question 205

A pt presenting with hypertension, hematuria, proteinuria, and edema likely has a _________ syndrome. One potential cause is ____________, an immune-complex mediated disease that occurs 2-4 weeks after exposure to group A beta hemolytic streptococcus.

Answer 205

Nephritic PSGN

Question 206

The most highly oxygenated blood in the fetus is carried by the ___________, which flows directly into the __________ via the ___________

Answer 206

Umbilical vein; IVC; ductus venosus

Question 207

The strain phase of valsalva, abrupt standing, and nitroglycerin administration will _________ the intensity of the murmur associated with hypertrophic cardiomyopathy. Sustained hand grip, squatting, and passive leg raise will ________ the intensity of the murmur associated with hypertrophic cardiomyopathy

Answer 207

Increase Decrease

Question 208

Most common cause of viral gastroenteritis

Answer 208

Norovirus

Question 209

Neurophysins are carrier proteins for _______ and _________. Thus, point mutations in neurophysin II underlie most cases of hereditary hypothalamic __________ __________

Answer 209

Oxytocin; ADH; diabetes insipidus

Question 210

Sitagliptin, an oral antidiabetic agent, functions by inhibiting the enzyme ______, which is responsible for the inactivation of incretins. This results in increased active incretin levels, leading to increased secretion of insulin and decreased secretion of glucagon

Answer 210

Dipeptidyl peptidase IV (DDP-IV)

Question 211

______ is an inhaled anesthetic associated with mild hepatotoxicity and more fulminant hepatitis

Answer 211

Halothane

Question 212

Cyanide is an inhibitor of what enzyme affecting oxidative phosphorylation?

Answer 212

Cyanide is an inhibitor of cytochrome c oxidase (part of 4th complex of ETC) It increases venous O2 saturation by preventing the body from using O2

Question 213

A deficiency in vitamin C would most affect the synthesis of which of the following neurotransmitters? ``` A. ACh B. Dopamine C. Glutamate D. Histamine E. Norepinephrine ```

Answer 213

E. Norepinephrine [Vitamin C is required for the conversion of dopamine to NE by the enzyme dopamine-beta-hydroxylase]

Question 214

Autosomal recessive disorder that affects the metabolism of methionine; manifests clinically with mental retardation, osteoporosis, tall stature, kyphosis, and atherosclerosis leading to stroke and MI at a young age

Answer 214

Homocysteinuria

Question 215

Diffuse esophageal spasm can cause retrosternal chest pain that is typically precipitated by cold or hot food; the pain can be intermittent and is not situation-dependent. It can show ______ pattern on barium swallow (but barium swallow can also be negative). This can ultimately lead to functional obstruction due to increased esophageal wall stress. What is first line treatment for diffuse esophageal spasm?

Answer 215

Corkscrew First line is CCBs like nifedipine, which act on L-type calcium channels of both cardiac and smooth muscle

Question 216

Transthyretin is a protein responsible for transporting vitamin A and thyroxine. Transthyretin ______ is an autosomal dominant condition, and an important subtype affects the heart, causing a restrictive cardiomyopathy

Answer 216

Amyloidosis

Question 217

Adenocarcinoma of the lung (NSCLC) is associated with mutation on the _____gene

Answer 217

K-ras

Question 218

Metachromatic leukodystrophy is due to a deficiency of __________, leading to accumulation of __________, which causes demyelination. Patients present with cognitive impairment, ataxia, and optic atrophy

Answer 218

Arylsulfatase A; cerebroside sulfate

Question 219

In essential fructosuria, _______ is able to phosphorylate fructose to fructose-6-phosphate, shunting it to glycolysis

Answer 219

Hexokinase

Question 220

Long-term uncontrolled diabetes can lead to diabetic hyporeninism, which causes RTA type ____, which presents with hyperkalemia.

Answer 220

RTA type IV [Other causes of RTA type IV include ACE inhibitors, ARBs, NSAIDs, and adrenal insufficiency. RTA types I and II present with hypokalemia. Causes of RTA type I include analgesic nephropathy and amphotericin toxicity in severe fungal infections. Causes of RTA type II include Fanconi syndrome and Acetazolamide]

Question 221

An intention tremor in the right arm indicates a lesion in which of the following? ``` A. Cerebellar vermis B. Left cerebellar hemisphere C. Left subthalamic nucleus D. Right cerebellar hemisphere E. Right subthalamic nucleus ```

Answer 221

D. Right cerebellar hemisphere [Lesions in cerebellar hemispheres can cause ataxia and intention tremors in ipsilateral limbs. Pts with lesions in the subthalamic nuclei present with contralateral hemiballismus]

Question 222

WAGR syndrome is due to a chromosomal deletion of the WT1 gene. What are the clinical features?

Answer 222

Wilms tumor Aniridia Genitourinary abnormalities Mental retardation

Question 223

Most effective class of medications to lower triglycerides

Answer 223

Fibrates

Question 224

______ ______ = description of anomalies including pulmonary hypoplasia, clubbed feet, and cranial abnormalities due to oligohydramnios

Answer 224

Potter sequence [classically due to bilateral renal agenesis; other causes include polycystic kidney disease, hydronephrosis, and any other cause of ureter obstruction]

Question 225

Most common cardiac defect seen in DiGeorge syndrome patients

Answer 225

Tetralogy of Fallot

Question 226

Disease characterized by rheumatoid nodules surrounded by pigmented cells in the lungs. It is specifically seen in rheumatoid arthritis patients who also have one of the pneumoconiosis

Answer 226

Caplan’s syndrome

Question 227

Beck’s triad of cardiac tamponade

Answer 227

1. Jugular venous distention 2. Hypotension (with pulsus paradoxus) 3. Diminished heart sounds

Question 228

Ehlers-Danlos syndrome is a group of CT disorders involving a defect in _____ synthesis

Answer 228

Collagen

Question 229

Small intestinal bacterial overgrowth (SIBO) is characterized by overproduction of _______ and _______, associated with nausea, bloating, abdominal discomfort, and malabsorption

Answer 229

Vitamin K; Folate

Question 230

Light microscopy revealing several small, ovoid bodies within a macrophage raise strong suspicion for ______ ________, a dimorphic fungus transmitted by inhalation. Patients with impaired immunity (e.g., advanced AIDS) are at risk for dissemination through the ___________ system; common manifestations include hepatosplenomegaly, lymphadenopathy, pancytopenia, and ulcerated lesions on the tongue

Answer 230

Histoplasma capsulatum; reticuloendothelial

Question 231

Microtubule-associated, ATP-powered motor protein that facilitates the anterograde transport of neurotransmitter-containing secretory vesicles down axons to synaptic terminals

Answer 231

Kinesin

Question 232

Which one causes transcriptional repression: acetylation of histones or deacetylation of histones?

Answer 232

Deacetylation of histones [This is the mechanism behind Huntington disease — abnormal huntingtin gene causes increased histone deacetylation, silencing the genes necessary for neuron survival]

Question 233

Pulmonary artery catheters are used to diagnose pulmonary HTN and occasionally for management of critically ill pts. The pressure measured at the catheter tip is called the pulmonary artery occlusion pressure (aka pulmonary capillary wedge pressure), and closely reflects the end-diastolic pressure in what heart chamber(s)?

Answer 233

Left atrium Left ventricle

Question 234

What triad of changes are seen on ECG with Wolff-Parkinson-White syndrome?

Answer 234

Shortened PR interval (<0.12s) Early upslope of QRS (delta wave) Widened QRS complex

Question 235

Treatment of choice for CMV

Answer 235

IV Ganciclovir [Works by competitively inhibiting incorporation of dGTP by viral DNA polymerase. Other options to tx CMV include oral valganciclovir, IV foscarnet, or IV cidofovir]

Question 236

2 most common causes of pulsus paradoxus without pericardial effusion

Answer 236

Asthma | COPD

Question 237

Farmer’s lung is a hypersensitivity pneumonitis caused by inhalation of thermophylic Actinomyces found in the dust from moldy hay. Initial treatment involves giving _______ to decrease the inflammatory response. Afterwards, avoiding exposure to offending agent and wearing a mask when exposure is possible

Answer 237

Corticosteroids

Question 238

_______ _______ are calcifications found in several benign or malignant tumors including papillary thyroid carcinoma, serous cystadenocarcinoma of the ovary, meningioma, and mesothelioma

Answer 238

Psammoma bodies

Question 239

Nerve roots associated with long thoracic n.

Answer 239

C5-7

Question 240

What is the most common enzyme deficiency associated with congenital adrenal hyperplasia, manifesting with hyponatremia, hyperkalemia, hypotension, and ambiguous external genitalia?

Answer 240

21-beta-hydroxylase deficiency

Question 241

What ligament prevents posterior translation of the tibia relative to the femur, and when ruptured the tibia rests in a more posterior position than usual?

Answer 241

Posterior cruciate ligament

Question 242

Which of the following is the treatment for carcinoid syndrome? ``` A. Hydroxyurea B. Leuprolide C. Octreotide D. Phentolamine E. Somatropin ```

Answer 242

C. Octreotide

Question 243

________ herniations result in ptosis, mydriasis, lateral strabismus, and contralateral hemiparesis of the extremities

Answer 243

Uncal

Question 244

Brown-Sequard syndrome results from a hemisection of the spinal cord. It is characterized by _________ spastic paralysis below the lesion, ________ loss of touch and vibration sensations below the lesion, and _________ loss of pain and temperature sensation below the lesion. [ipsilateral/contralateral/bilateral]

Answer 244

Ipsilateral; ipsilateral; contralateral

Question 245

Henoch-Schonlein purpura, a _____ (small/medium/large) vasculitis that occurs in children. It is a type _____ hypersensitivity characterized by ___________ on vessel walls

Answer 245

Small; III; IgA immune complexes

Question 246

CLL is associated with _______ about 10% of the time, which is an anemia characterized by an elevated reticulocyte count, a reduced haptoglobin level, and a positive Coombs test, as well as the presence of ______ on peripheral smear

Answer 246

Autoimmune hemolytic anemia (AIHA); spherocytes [Note: the differential diagnosis for spherocytosis includes hereditary spherocytosis and autoimmune hemolytic anemia]

Question 247

New-onset seizures in adults justify MRI to exclude the possibility of an intracranial neoplasm. __________ are most commonly located in the frontal lobes, and examination will reveal the presence of rounded cells with perinuclear halos giving them “fried egg” appearance. They also have the presence of finely branching capillaries, which looks like “chicken wire”

Answer 247

Oligodendrogliomas

Question 248

A lesion in which hypothalamic nucleus would lead to difficulty lowering body temperature?

Answer 248

Anterior [lesion in dorsomedial nucleus leads to decreased aggression and feeding, lesion in lateral nucleus leads to decreased feeding, lesion in supraoptic nucleus leads to DI, lesion in ventromedial nucleus leads to increased feeding

Question 249

Pronator syndrome occurs when the _____ nerve is compressed

Answer 249

Median

Question 250

A biopsy of a breast lesion shows large, atypical adenocarcinoma cells with pale to clear cytoplasm that infiltrate below the epidermis; when in the context of scaly, raw, and sometimes ulcerated lesions of the nipple associated with pain, burning, and pruritis, this biopsy is indicative of what condition?

Answer 250

Paget disease

Question 251

What is the etiology of hypercortisolism if a low-dose dexamethasone suppression test fails to suppress cortisol levels, but a high-dose dexamethasone suppression test decreases cortisol levels?

Answer 251

Cushing disease (pituitary ACTH-secreting adenoma)

Question 252

Marfan syndrome is an autosomal dominant disease caused by point mutations in the FBN1 gene on chromosome _____

Answer 252

15

Question 253

How does asbestosis show up on lung biopsy?

Answer 253

Interstitial fibrosis with occasional ferruginous bodies (arise from iron and protein coating with inhaled fibers)

Question 254

Which of the following is associated with AE of galactorrhea? ``` A. Fluoxetine B. Haloperidol C. Lithium D. Nortriptyline E. Phenelzine ```

Answer 254

B. Haloperidol [This drug is a dopamine antagonist]

Question 255

Autosomal dominant genetic condition characterized by the constellation of mucosal neuromas, marfanoid body habitus, medullary thyroid carcinoma, and pheochromocytoma

Answer 255

MEN2B

Question 256

3 findings in MEN1

Answer 256

Pituitary adenoma Parathyroid hyperplasia Pancreatic tumors (e.g., gastrinoma, insulinoma, vipoma, glucagonoma)

Question 257

3 findings in MEN2A

Answer 257

Parathyroid hyperplasia Medullary thyroid carcinoma Pheochromocytoma

Question 258

Most common non-epithelial benign neoplasm of the GI tract; symptoms include early satiety and abdominal bloating. When these tumors contain KIT mutations, they almost always display spindle-shaped cells on biopsy

Answer 258

Gastrointestinal stromal tumor (GIST)

Question 259

Gene mutation associated with Peutz-Jegher’s syndrome

Answer 259

STK11

Question 260

Which of the following presents as painful vaginal bleeding in the 2nd or 3rd trimester and is associated with increased risk due to HTN, smoking, and use of cocaine? ``` A. Ectopic pregnancy B. Incomplete abortion C. Placental abruption D. Placenta accreta E. Placenta previa ```

Answer 260

C. Placental abruption [note that placenta previa presents with PAINLESS vaginal bleeding during 2nd or 3rd trimester with risk factors of previous C section and multiparity]

Question 261

The levator scapulae muscle is innervated by a nerve supply from the roots of ______

Answer 261

C3-5

Question 262

In persons with schizophrenia resistant to multiple trials of both 2nd and 1st generation antipsychotics, the atypical antipsychotic ________ has been found to be an effective treatment. The most serious and potentially life threatening side effect of this medication is ________

Answer 262

Clozapine; agranulocytosis [Other AEs of clozapine include weight gain, diabetes, hyperlipidemia, seizure, myocarditis, salivation, and sedation]

Question 263

How do aldosterone levels change in pregnancy?

Answer 263

Aldosterone levels increase due to increased activation of RAAS

Question 264

Polycythemia vera is associated with _____ serum erythropoietin concentrations

Answer 264

Low — due to negative feedback effect

Question 265

Artery involved in stroke leading to ipsilateral face analgesia, contralateral body analgesia, dysarthria, dysphagia, and ataxia

Answer 265

Posterior inferior cerebellar artery [note that stroke affecting anterior inferior cerebellar artery also presents with ipsilateral face analgesia and contralateral body analgesia, but instead of dysarthria/dysphagia/ataxia, the additional findings are ipsilateral face hemiparesis and ipsilateral deafness]

Question 266

Artery involved in stroke leading to contralateral hemianesthesia, contralateral hemiplegia, contralateral homonymous hemianopia, ipsilateral horizontal gaze preference

Answer 266

Middle cerebral artery

Question 267

Innervation of the short head and long head of biceps femoris

Answer 267

Short head = common fibular branch of the sciatic n. (L5-S2) Long head = tibial branch of the sciatic n. (L5-S3)

Question 268

Lateral medullary syndrome typically includes ipsilateral ______ syndrome

Answer 268

Horner’s

Question 269

Condition characterized by abnormal proliferation of mast cells (often associated with mutations in the KIT receptor tyrosine kinase) and increased histamine release. Histamine causes hypersecretion of gastric acid by parietal cells in the stomach as well as a variety of other symptoms (e.g., hypotension, flushing, pruritis)

Answer 269

Systemic mastocytosis

Question 270

The brachial artery, median nerve, and radial nerve all run anterior to the elbow and may be injured in supracondylar humeral fractures. Of these, the ___________ is the structure most likely to be injured with lateral displacement of the proximal fracture fragment

Answer 270

Radial n

Question 271

What 2 classes of medications should be avoided in pts with hypertrophic cardiomyopathy?

Answer 271

Vasodilators (eg, dihydropyridine CCBs, nitroglycerin, ACE-Is) Diuretics [Pts with HCM have dynamic left ventricular outflow tract obstruction that worsens with decreased LV volume — so any meds that decrease preload and/or reduce systemic vascular resistance should be avoided]

Question 272

Obligate intracellular protozoa that mature in macrophages and can be identified on biopsy by the presence of rod-shaped kinetoplasts

Answer 272

Leishmania spp. [Transmission via infected sand flies —> syndrome of cutaneous leishmaniasis, characterized by chronic pinkish papule that evolves into nodule or plaque]

Question 273

Tay-Sachs and Niemann-Pick disease are very similar in that they both present with neurologic regression and cherry-red macular spots. The differentiating factor is the presence or absence of hepatosplenomegaly. Of the two, which one is associated with hepatosplenomegaly as an additional finding?

Answer 273

Niemann Pick

Question 274

CKD can cause hyperphosphatemia due to decreased renal excretion of phosphorus. Dietary phosphorus restriction is recommended, but oral phosphate binders are often needed. _______ is a nonabsorbable anion-exchange resin that binds intestinal phosphate to reduce absorption

Answer 274

Sevelamer

Question 275

T lymphocytes are important for the prevention of superficial candida infection, while ________ are the immune cells responsible for preventing its hematogenous spread

Answer 275

Neutrophils

Question 276

Which of the following causes the form of SCID in which flow cytometry demonstrates reduced levels of B-, T-, and NK-lymphocytes? A. Defect in DNA double-strand break repair enzymes B. Lack of NADPH oxidase C. Adenosine deaminase deficiency D. Defective CD40L signaling E. Defective neutrophil phagosome-lysosome fusion

Answer 276

C. Adenosine deaminase deficiency

Question 277

Thumb adduction is a function of the ______ nerve, and is the only thumb movement not controlled by the ______ nerve.

Answer 277

Ulnar; median

Question 278

Genetic testing techniques utilized in chromosome analysis include ___________ which detects presence/absence of specific DNA sequences in a specific chromosome location, and _________ which detects gross abnormalities in chromosomes

Answer 278

FISH; karyotyping

Question 279

ABCDE of Sarcoidosis

Answer 279

ABCDE of sarcoid = elevated ACE, bilateral hilar LAD, elevated Calcium, elevated vitamin D, Erythema nodosum

Question 280

Trazodone is an atypical antidepressant that also causes sedation and aids in weight loss. It is a weak inhibitor of the 5-HT2A receptor, as well as inhibitor of H1-receptor. It is commonly associated with what adverse effect?

Answer 280

Priapism

Question 281

Treatment for Actinomyces israelii

Answer 281

Penicillin [Since it is a gram-positive rod, A.israelii is very sensitive to beta-lactam drugs, such as penicillin, which inhibit peptidoglycan synthesis]

Question 282

What are the “ABC’s of anaerobes” to remember?

Answer 282

Actinomyces Bacteroides Clostridium

Question 283

Which of the following is associated with increased uric acid levels and potential to precipitate a gout attack? ``` A. Lisinopril B. Losartan C. Metformin D. Niacin E. Sulfonylurea ```

Answer 283

D. Niacin

Question 284

Which of the following is affected in an ovarian torsion? ``` A. Broad ligament B. Cardinal ligament C. Infundibulopelvic ligament D. Ovarian ligament E. Round ligament ```

Answer 284

C. Infundibulopelvic ligament [this is analagous to suspensory ligament of the ovary]

Question 285

__________ is the enzyme that converts testosterone to dihydrotestosterone. Deficiency is autosomal recessive and limited to genotypical males. When the enzyme is deficient, males have ambiguous genitalia until puberty because the development of male genitalia is dependent on high levels of androgens

Answer 285

5-alpha-reductase

Question 286

Alport syndrome presents with renal failure and hearing loss. It is caused by a defect in _____________, the type of collagen found in basement membranes

Answer 286

Type IV collagen

Question 287

___________ is an X-linked congenital immunodeficiency characterized by recurrent pyogenic infections and eczema due to IgM deficiency and IgA excess. It is associated with a mutation of the ______ gene on the X chromosome

Answer 287

Wiskott-Aldrich syndrome; WASp

Question 288

Drug of choice in treating acute Chagas disease

Answer 288

Nifurtimox

Question 289

Which of the following is an H2 inhibitor utilized to decrease gastric acidity? ``` A. Loratadine B. Misoprostol C. Odansetron D. Rabeprazole E. Ranitidine ```

Answer 289

E. Ranitidine [H2 blockers include cimetidine, ranitidine, nizatidine, and famotidine. Note that loratadine is an H1 blocker utilized for allergic rhinitis]

Question 290

Which of the following is most likely associated with a 21-hydroxylase deficiency? ``` A. Elevated angiotensin II B. Elevated BP C. Elevated glucocorticoids D. Hyperplasia of adrenal medulla E. Hypersecretion from the zona fasciculata ```

Answer 290

A. Elevated angiotensin II [21-hydroxylase deficiency leads to the inability of the adrenal cortex to produce glucocorticoids and mineralocorticoids. This is the most common form of CAH. This leads to hypotension (salt-wasting) and thus activation of the RAAS]

Question 291

The second-generation tetracyclines (doxycycline) and macrolides are the drugs of choice for Mycoplasma pneumoniae causing community-acquired pneumonia. Note that tetracyclines are teratogenic and thus contraindicated in pregnancy, in which case macrolide antibiotics such as Azithromycin would be preferred. What is the MOA of macrolides?

Answer 291

Binds 50S ribosomal subunit and blocks dissociation of peptidyl tRNA from ribosomes, ultimately arresting RNA-dependent protein synthesis

Question 292

What class of antibiotics can be used for outpatient tx of uncomplicated UTI, and are associated with the AE of QT prolongation and Torsade de pointes?

Answer 292

Fluoroquinolones

Question 293

_________ is a class IB antiarrhythmic that blocks sodium channels and preferentially slows depolarization in ischemic tissue. The most common adverse effects involve the CNS - including drowsiness, numbness, speech disturbance, and dizziness.

Answer 293

Lidocaine

Question 294

______ is a class III (blocks potassium channels) antiarrhythmic medication that is unique in that it also has powerful class I activity (blocks sodium channels), and ancillary class II (blocks beta-receptors) and class IV (blocks calcium channels). It is utilized for ventricular arrhythmias and works by prolonging the cardiac action potential

Answer 294

Amiodarone

Question 295

Which of the following is utilized as a part of HAART in HIV therapy and inhibits reverse transcriptase without incorporation into viral DNA? ``` A. Acyclovir B. Efavirenz C. Nelfinavir D. Saquinavir E. Zidovudine ```

Answer 295

B. Efavirenz [Other NNRTIs include delavirdine, nevirapine, and rilpivirine]

Question 296

The ______ is the primary rotator cuff muscle involved in external rotation of the upper extremity, assisted by another rotator cuff muscle _________, which is innervated by the _______ nerve

Answer 296

Infraspinatus; teres minor; axillary

Question 297

Which of the following is most likely to cause tardive dyskinesia? ``` A. Clozapine B. Fluphenazine C. Lithium D. Risperidone E. Selegiline ```

Answer 297

B. Fluphenazine [Long-term treatment with typical antipsychotics, such as haloperidol, trifluoperazine, fluphenazine, thioridazine, and chlorpromazine, can cause tardive dyskinesia]

Question 298

The mechanism of action of cyclosporine is that it binds to cyclophilins inhibiting ________ and thereby preventing the production of IL-2 and its receptors. This drug is used to suppress organ rejection after transplant surgeries. It can also cause nephrotoxicity, hirsutism, and gingival hyperplasia

Answer 298

Calcineurin

Question 299

Donepezil is utilized in the tx of Alzheimers disease. What is its MOA?

Answer 299

Acetylcholinesterase inhibitor

Question 300

Persistent inflammatory muscle disease that causes weakness of the skeletal muscles via cytotoxic T-cell mediated process directed against muscle fascicles. Presents with onset of proximal muscle weakness and possible complaints of difficulty with kneeling, climbing or descending stairs, raising arms, lifting objects, combing hair, and arising from seated position

Answer 300

Polymyositis [Note that lab studies reveal elevated serum creatine kinase, lactate dehydrogenase, and aldolase, as well as anti-Jo-1 antibodies in serum]

Question 301

Which of the following would most likely be positive in a pt with atypical pneumonia due to Mycoplasma pneumoniae? ``` A. Catalase test B. Coagulase test C. Cold agglutinin titer D. Maltose test E. Warm agglutinin titer ```

Answer 301

C. Cold agglutinin titer

Question 302

Infection with the nematode Loa loa may be asymptomatic, or may present with local hypersensitivity reaction causing episodic subcutaneous angioedema of the extremities with local pain and pruritis. Adult filarial worms may migrate into subconjunctival tissues of the eye where they can be easily observed. Loa loa infection is treated with ________, which is an antihelminthic agent that acts by inhibiting arachidonic acid metabolism in filarial microfilaria, which disrupts their membranes and makes them more susceptible to immune attack

Answer 302

Diethylcarbamazine

Question 303

Primary hyperaldosteronism (Conn syndrome) may show increased _____ levels which will help maintain normal serum sodium levels chronically, i.e., the “sodium escape” phenomenon, even in the face of increased aldosterone levels. Other features may include hypokalemia, lack of edema, hypomagnesemia, and metabolic alkalosis

Answer 303

ANP

Question 304

________, the most common cause of gastritis with watery diarrhea in infants, has a unique genome consisting of dsRNA

Answer 304

Rotavirus

Question 305

Sympathetic innervation of the testicles

Answer 305

T10-11

Question 306

One treatment option for BPH is tamsulosin, which is an _______________ that will inhibit smooth muscle contraction of the prostatic urethra, making urination more normal and improving pt quality of life. AEs include hypotension and dizziness

Answer 306

Alpha-1 antagonist

Question 307

_________ is a non-enveloped linear dsDNA virus that is stable in chlorinated water, and therefore can infect patients in swimming pools via contaminated respiratory secretions in the water

Answer 307

Adenovirus

Question 308

Which of the following is an adverse effect of amiodarone? ``` A. Bronchoconstriction B. Lower extremity edema C. Pulmonary fibrosis D. Reflex tachycardia E. Torsades de pointes ```

Answer 308

C. Pulmonary fibrosis [Others include thyroid dysfunction, hepatotoxicity, ocular changes, and skin reactions]

Question 309

Autosomal dominant trinucleotide expansion disease exhibiting repeats of CTG within DMPK gene, leading to myotonia (noted with sustained grasp), muscle wasting, frontal balding, cataracts, testicular atrophy, and arrhythmias.

Answer 309

Myotonic muscular dystrophy

Question 310

What is the advantage of using amoxicillin over ampicillin?

Answer 310

They are similar, but amoxicillin has better bioavailability from the GI tract due to greater stability in gastric acid — thus it has greater oral absorption

Question 311

A major side effect of phenytoin is a ________ anemia due to _______ deficiency, specifically due to inhibition of intestinal conjugase needed to convert this nutrient into the absorbable form

Answer 311

Megaloblastic; folate

Question 312

A patient with megaloblastic anemia due to folate deficiency caused by phenytoin therapy is at increased risk for which of the following: ``` A. Achlorhydria B. Demyelination of the spinal cord C. Direct myopathy D. Nystagmus E. Vessel thrombosis ```

Answer 312

E. Vessel thrombosis [pts with folate deficiency present with an elevated level of homocysteine — which leads to a state of hypercoagulability as well as destruction of arteries]

Question 313

Autosomal dominant condition characterized by the triad of eczema, eosinophilia, and recurrent skin and pulmonary infection; also associated with multiple connective tissue and skeletal abnormalities, including scoliosis, hyperextensibility, pathologic fractures, retained primary dentition, craniosynostosis, and vascular abnormalities

Answer 313

Hyperimmunoglobulinemia E (aka Job syndrome)

Question 314

Antibodies associated with Hashimoto thyroiditis

Answer 314

Anti-microsomal

Question 315

Of the rotator cuff muscles, the _____ and _____ externally rotate the arm, while the _______ acts to internally rotate the arm

Answer 315

Infraspinatus; teres minor; subscapularis

Question 316

The ulnar nerve arises from the ____ cord of the brachial plexus. The medial and lateral cords of the brachial plexus combine to give rise to the ______ nerve. The posterior cord of the brachial plexus give rise to the _____ and _____ nerves

Answer 316

Medial Median Axillary; radial

Question 317

Genetics associated with Wilms tumor

Answer 317

Deletion of WT1 gene on chromosome 11

Question 318

What water-soluble vitamin deficiency can occur secondary to poor diet, excessive raw egg white consumption, and congenital disorders of metabolism?

Answer 318

Biotin (vitamin B7) [Note that biotin is an important cofactor for several carboxylase enzymes. In the liver, the conversion of pyruvate to oxaloacetate for gluconeogenesis requires pyruvate carboxylase and biotin]

Question 319

The ______ of the cell is home to enzymes necessary for glycolysis, fatty acid synthesis, and the pentose phosphate pathway

Answer 319

Cytosol [Contrast with beta-oxidation of fatty acids, TCA cycle, and gluconeogenesis which occur in the mitochondria]

Question 320

Chronic lung transplant rejection is due primarily to progressive scarring of the small airways, leading to _______ _______. Manifestations occur months or years after transplantation and include obstructive lung disease (e.g., reduced FEV1) with dyspnea and dry cough

Answer 320

Bronchiolitis obliterans

Question 321

The ureters originate bilaterally at the renal pelvis and course inferiorly toward the bladder within the retroperitoneum just anterior to the psoas muscles. Midway from the kidney to the pelvic inlet, the ureters cross _______ to the gonadal artery and vein. The ureters then gain access to the pelvis by crossing _______ to the external iliac artery at, or just after, the bifurcation of the common iliac artery. At this point, the ureter lies ______ to the ovarian vessels, and ______ to the internal iliac artery.

Answer 321

Posterior; anterior Medial; anterior

Question 322

Key findings include fetal growth retardation, hypertonia (clenched hands with overlapping fingers), rocker bottom feet, and cardiac/GI/renal defects; most commonly the result of meiotic nondisjunction due to advanced maternal age

Answer 322

Trisomy 18 (Edwards syndrome) [Note that trisomy 13 (patau syndrome) presents with midline facial defects (e.g., holoprosencephaly, cleft lip/palate), MSK abnormalities (polydactyly), and GI anomalies (omphalocele, umbilical hernia); it is not associated with overlapping fingers]

Question 323

With Plasmodium (malaria) infection, erythrocytic forms of the parasite may be treated with antimalarials such as ________ (in non-resistant areas), _________, and _________. _______ is required to kill P vivax and P ovale liver hypnozoites

Answer 323

Chloroquine; atovaquone-proguanil; artemisinins Primaquine

Question 324

Deficiency of what vitamin is associated with complications from Measles virus (rubeola)?

Answer 324

Vitamin A [acute measles depletes vitamin A stores, resulting in risk of keratitis and corneal ulceration]

Question 325

Which of the following embryological events is most likely responsible for tetralogy of fallot? a. Anomalous pulmonary venous return b. Aortic arch constriction c. Deviation of the infundibular septum d. Endocardial cushion defect e. Linear development of the aorticopulmonary septum

Answer 325

c. Deviation of the infundibular septum [Tetralogy of Fallot results from anterior and cephalad deviation of the infundibular septum during embryologic development, resulting in a malaligned VSD with an overriding aorta]

Question 326

The Kozak consensus sequence occurs on eukaryotic mRNA and is defined by the following sequence: (gcc)gccRccAUGG, in which R is either ______ or ______. This sequence helps initiate translation at the methionine start codon (AUG), thus a substitution for one of the above nucleotides would impair initiation of translation

Answer 326

adenine; guanine

Question 327

Enzyme found in adipose tissue, where it functions to drive the breakdown of stored triglycerides into FFAs and glycerol. During times of starvation, this enzyme provides substrates for hepatic gluconeogenesis and ketone body formation

Answer 327

Hormone-sensitive lipase

Question 328

_________ is a cofactor used by hydroxyls enzymes in the synthesis of tyrosine, dopamine, and serotonin. PKU can result from a deficiency in this cofactor, and intellectual disability is the hallmark.

Answer 328

Tetrahydrobiopterin (BH4)

Question 329

Common fibular nerve injuries may result in what motor and sensory defects?

Answer 329

Weakness of dorsiflexion (deep fibular n) Weakness of eversion (superficial fibular n) Loss of sensation over the dorsum of the foot

Question 330

Autosomal recessive inherited defect in lipoprotein lipase (or ApoC-II) resulting in acute pancreatitis, lipemia retinalis (milky-appearing retinal vasculature), eruptive skin xanthomas, and HSM

Answer 330

Familial Chylomicronemia Syndrome (Type I hyperlipoproteinemia)

Question 331

How do the pupils react to light in the right vs. left eye when the left optic nerve is damaged?

Answer 331

When light is shined in the left eye (the eye with the damaged optic nerve), neither pupil will constrict because the nerve can’t sense the light. However, light in the right eye will cause both pupils to constrict because the motor pathways are intact

Question 332

Neurologic damage associated with vitamin B12 deficiency classically includes subacute combined degeneration of what 3 spinal cord tracts?

Answer 332

Dorsal columns (loss of position and vibration sense, sensory ataxia) Lateral corticospinal tracts (spastic paresis) Spinocerebellar tracts (contributes to ataxia)

Question 333

HIV attaches to host cells using the viral surface protein ______, which binds the CD4 molecule as the primary receptor and the chemokine receptor _______ as a coreceptor. Binding of the primary receptor and coreceptor induces a conformational change in the viral surface protein that exposes underlying transmembrane protein _____, which mediates viral fusion to the host cell and release of viral capsid into the cytoplasm

Answer 333

gp120; CCR5 gp41

Question 334

Congenital condition that is usually asymptomatic at birth but later infants present with constipation, lethargy, hypotonia, macroglossia, an umbilical hernia, and large anterior fontanelle

Answer 334

Congenital hypothyroidism (cretinism)

Question 335

T/F: nucleotide excision repair involves removal of deaminated bases by glycosylase

Answer 335

False — Nucleotide excision repair involves endonuclease nicking of the damaged DNA strand and typically occurs in the case of sunburn. Base excision repair involves removal of deaminated bases by glycosylase — this process may occur spontaneously or secondary to chemical exposure

Question 336

mRNA splicing is performed by spliceosomes, which remove introns containing _____ at the 5’ splice site, and _____ at the 3’ splice site. Splice site mutations may result in inappropriate removal of exons and retention of introns, leading to the formation of dysfunctional proteins

Answer 336

GU; AG

Question 337

Most common type of placentation in dizygotic vs. monozygotic twins

Answer 337

Dizygotic = dichorionic/diamnionic Monozygotic = monochorionic/diamnionic

Question 338

5 catalase positive organisms

Answer 338

Staphylococcus aureus Burkholderia cepacia Serratia marcescens Nocardia Aspergillus

Question 339

Beta-endorphin is one endogenous opioid peptide that is derived from proopiomelanocortin (POMC). POMC is a polypeptide precursor that goes through enzymatic cleavage and modification to produce not only beta-endorphins, but also _____ and ______.

Answer 339

ACTH; MSH

Question 340

_______ is a peptide that is structurally similar to insulin. Also referred to as insulin-like growth factor, this peptide is released in response to growth hormone and stimulates growth in target cells

Answer 340

Somatomedin C

Question 341

What syndrome typically occurs 2-8 weeks after exposure to high-risk drugs such as anticonvulsants (e.g., phenytoin, carbamazepine), allopurinol, sulfonamides (e.g., sulfasalazine), and antibiotics (e.g., minocycline, vancomycin). Patients typically develop fever, generalized LAD, facial edema, diffuse skin rash, eosinophilia, and internal organ dysfunction

Answer 341

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome

Question 342

The most classic clinical triad of congenital ______ includes congenital cataracts (white pupils), sensory-neural deafness, and a patent ductus arteriosus

Answer 342

Rubella [prevented with live attenuated rubella virus vaccine pre-conception]

Question 343

The bilateral _______ veins combine to form the SVC, and obstruction causes symptoms similar to those seen in SVC syndrome, but only on one side of the body

Answer 343

Brachiocephalic

Question 344

_______ converts androgens into estrogens in the ovaries, testes, placenta, and other peripheral tissues. Placental deficiency of this enzyme causes accumulation of androgens during pregnancy, resulting in ambiguous external genitalia in female infants and maternal virilization

Answer 344

Aromatase

Question 345

The __________ arteries supply the medial portions of the 2 hemispheres (frontal and parietal lobes). Occlusion can cause contralateral motor and sensory deficits of the lower extremities, behavioral changes, and urinary incontinence

Answer 345

Anterior cerebral aa.

Question 346

Which of the following has the lowest ID50 (requires the lowest number of bacteria to cause infection)? ``` A. Clostridium perfringens B. Enterotoxigenic E.coli C. Shigella flexneri D. Vibrio cholerae E. Vibrio parahaemolyticus ```

Answer 346

C. Shigella flexneri

Question 347

Activating mutations of the _____ gene lead to constitutive activation of the EGFR pathway, promoting increased cell proliferation and growth. Tumors harboring these mutations are resistant to treatment with anti-EGFR drugs (e.g., cetuximab, panitumumab)

Answer 347

KRAS

Question 348

IV drug use is a major risk factor for hepatitis B and C viral infection. Acute viral hepatitis is marked by panlobular inflammation and hepatocyte necrosis and ballooning. ________-mediated signals also cause hepatocyte apoptosis with the formation of intensely eosinophilic _______ bodies

Answer 348

CTL; Councilman

Question 349

In prokaryotes, ___________ has 5’ to 3’ exonuclease activity in addition to 5’ to 3’ polymerase and 3’ to 5’ exonuclease activities. This 5’ to 3’ exonuclease activity functions to remove the RNA primer created by RNA primase and repair damaged DNA sequences

Answer 349

DNA polymerase I

Question 350

G6PD deficiency is an X-linked recessive disorder resulting in episodic bouts of hemolysis when RBCs experience increased oxidative stress. G6PD is the rate-limiting step of _________________. It catalyzes the conversion of glucose-6-phosphate to 6-phosphogluconolactone, which is subsequently converted to _____________. The purpose of this pathway is to generate NADPH and ribose-5-phosphate. NADPH can be used to maintain a stead supply of glutathione.

Answer 350

Pentose phosphate pathway; 6-phosphogluconate

Question 351

Bullous impetigo is a superficial infection by Staphylococcus aureus that is most common in young children. It is characterized by a blistering skin rash with tan- to honey-colored crusts. The blistering in bullous impetigo is caused by __________, which targets _________ in epidermal cellular junctions and causes a loss of cell adhesion

Answer 351

Exfoliative toxin A; desmoglein 1 [Pemphigus vulgaris involves autoantibodies against desmosomes (desmogleins 1 and 3). Bullous pemphigoid involves autoantibodies against hemidesmosomes]

Question 352

_______ pneumonia is common in pts with advanced HIV and usually presents with slowly worsening cough, dyspnea, hypoxia, bilateral interstitial infiltrates, fever, and weight loss. Diagnosis requires visualizing the organism in respiratory secretions using special stains (e.g., methanamine silver stain). First-line treatment is __________

Answer 352

Pneumocystis; TMP-SMX

Question 353

What 2 stool tests are utilized in the diagnoses of Clostridium difficile infection? Which one is most sensitive and specific?

Answer 353

Nucleic acid amplification test (NAAT) — uses PCR to detect genes present in toxigenic strains (e.g., toxin B-encoding gene). This test is highly sensitive and specific for toxigenic strains but does not distinguish active toxin production and may lead to overdiagnosis in asymptomatic carriers Enzyme immunoassays — use Abs to detect C diff antigens or toxins. Highly specific but poor sensitivity.

Question 354

What class of HIV antiretrovirals carry the side effect profile including hyperglycemia, lipodystrophy, and drug-drug interactions due to inhibition of CYP450?

Answer 354

Protease inhibitors

Question 355

Tumor cell lines can become resistant to therapy after exposure to various anticancer agents. These cells express a P-glycoprotein encoded for by the ____________ gene. This P-glycoprotein is a transmembrane ATP-dependent efflux pump protein that has a broad specificity for hydrophobic compounds. It can both reduce the influx of drugs into the cytosol and can increase efflux from the cytosol, thereby preventing the action of chemotherapeutic agents

Answer 355

MDR1 (human multidrug resistance gene)

Question 356

Familial dysbetalipoproteinemia (type III hyperlipoproteinemia) is an autosomal recessive disorder characterized by elevated cholesterol and triglyceride levels. It is caused by defects in ____ and _____, leading to decreased clearance of chylomicrons and VLDL remnants. Patients can develop eruptive and palmar xanthomas and premature atherosclerosis

Answer 356

ApoE3; ApoE4

Question 357

Blanching of a vein into which norepinephrine is being infused together with induration and pallor of the tissues surrounding the IV site are signs of NE extravasation and resulting vasoconstriction. Tissue necrosis is best prevented by local injection of a _______-blocking drug, such as _______

Answer 357

Alpha 1; phentolamine

Question 358

Nontypeable strains of Haemophilus influenzae are part of the normal upper respiratory tract flora and are a common cause of acute otitis media, sinusitis, and bronchitis. Because nontypeable strains do not form a _______________, immunity is not conferred by vaccination with the H influenzae type b vaccine

Answer 358

Polysaccharide capsule

Question 359

MOA of DPP-4 inhibitors (e.g., sitagliptin, saxagliptin) utilized in diabetes

Answer 359

Inhibit the degradation of GLP-1, prolonging its effects and leading to improved glycemic control [GLP-1 acts to slow gastric emptying, suppress glucagon secretion, and increase glucose-dependent insulin release] Major side effects include nasopharyngitis and other upper respiratory symptoms

Question 360

The candidal antigen skin test is used to determine the presence of cellular immunity through the detection of a delayed-type hypersensitivity reaction (type IV). What are the 3 key cells involved in the response with a positive test?

Answer 360

Macrophages CD4+ T cells CD8+ T cells

Question 361

The _______ _______ is a paired brainstem nucleus located in the posterior rostral pons near the lateral floor of the 4th ventricle. It projects to virtually all parts of the CNS and helps control mood, arousal (reticular activating system), sleep-wake states, cognition, and autonomic function. It functions as the principal site for _______ synthesis in the brain

Answer 361

Locus ceruleus; norepinephrine

Question 362

Hereditary pulmonary arterial hypertension is most often due to autosomal dominant inactivating mutation in BMPR2. How does this lead to the condition of Hereditary PAH?

Answer 362

Patients with this mutation have a predisposition for dysfunctional endothelial and smooth muscle cell proliferation An insult (e.g., infection, drugs) is thought to then activate the disease process. The end result is vasoconstriction with vascular smooth muscle proliferation, intimal thickening and fibrosis, increased pulmonary vascular resistance, and progressive pulmonary HTN.

Question 363

Lactose intolerance presents with flatulence, crampy abdominal pain, and watery diarrhea after dairy product consumption. Studies can show _______ breath hydrogen content, _______ stool pH, and _______ stool osmolality

Answer 363

Increased; decreased; increased

Question 364

What structures are associated with the first and second pharyngeal arches? What syndrome is associated with abnormal development of these 2 arches?

Answer 364

First pharyngeal arch = CN V, maxilla, zygoma, mandible, incus, malleus, masseter m., temporalis m. Second pharyngeal arch = CN VII, styloid process of temporal bone, lesser horn of hyoid, stapes, muscles of facial expression Abnormal development of the first and second arches —> Treacher-Collins syndrome, characterized by craniofacial abnormalities and conductive hearing loss

Question 365

Which of the following is characteristic of NSAID-induced kidney injury? A. Impaired afferent arteriolar vasodilation B. Impaired efferent arteriolar vasodilation C. Interstitial inflammation D. Toxic injury to the proximal tubules E. Vasculitis of the glomerular capillaries

Answer 365

A. Impaired afferent arteriolar vasodilation [NSAIDs inhibit prostaglandin synthesis, which can cause prerenal azotemia in at-risk patients. Patients with intravascular volume depletion (e.g., CHF, diarrhea, excess diuresis) and CKD depend on renal prostaglandin production to dilate the afferent glomerular arteriole and maintain GFR]

Question 366

How does pyruvate kinase deficiency cause splenomegaly?

Answer 366

Pyruvate kinase deficiency causes hemolytic anemia due to failure of glycolysis and resultant failure to generate sufficient ATP to maintain erythrocyte structure As reticuloendothelial cells in the splenic red pulp are involved in removal of damaged RBCs, their increased activity in the setting of pyruvate kinase deficiency causes them to undergo hyperplasia —> splenomegaly

Question 367

Occlusion of the __________ artery typically results in contralateral hemiparesis and hemisensory loss of the face and upper limb with relative preservation of lower limb function. If the occluded artery is in the dominant (usually left) hemisphere, aphasia may also occur.

Answer 367

Middle cerebral a.

Question 368

______________ is an autosomal dominant condition caused by porphobilinogen deaminase deficiency. Most patients remain asymptomatic, but a minority present with acute attacks characterized by abdominal pain and vomiting, peripheral neuropathy, neuropsychological symptoms, and reddish-brown urine. Treatment consists of IV glucose or heme preparations, which downregulate ____________ enzyme activity

Answer 368

Acute intermittent porphyria; ALA synthase

Question 369

________ syndrome results from damage to the angular gyrus of the dominant parietal lobe and is characterized by agraphia, acalculia, finger agnosia, and left-right disorientation

Answer 369

Gerstmann

Question 370

Histologically, GISTs are characterized by a proliferation of stromal or epithelioid type cells and stain positive for _______, an oncogene involved in the pathogenesis of the tumor. This gene encodes a tyrosine kinase that is involved in cell proliferation and differentiation

Answer 370

c-kit

Question 371

Test utilized in pts with malabsorption after an abnormal fecal fat test; reflects intestinal transport function and surface area, making it useful to differentiate between pancreatic disease and mucosal disease

Answer 371

D-xylose test [patients with pancreatic disease will have normal test because problem is with digestion, not absorption. Patients with mucosal disease will have abnormal test]

Question 372

What type of anemia is associated with SLE — cold hemolytic anemia or warm hemolytic anemia?

Answer 372

Warm hemolytic anemia — in which there is a positive Coombs test at 37 C but not at 4 C

Question 373

3rd gen cephalosporin used to treat Pseudomonas aeruginosa

Answer 373

Ceftazidime [other tx options include extended-spectrum penicillins (piperacillin, ticarcillin) and 4th gen cephalosporin Cefepime]

Question 374

antibodies present in CREST syndrome

Answer 374

Anti-centromere

Question 375

CN and pharyngeal arch associated with mandible, maxilla, zygoma, incus, and malleus; portion of maxillary a.

Answer 375

Arch 1; CN V

Question 376

CN and pharyngeal arch associated with stapes, styloid, lesser horn of hyoid

Answer 376

Arch 2; CN VII

Question 377

CN and pharyngeal arch associated with greater horn of hyoid, common carotid a., and proximal internal carotid a.

Answer 377

Arch 3; CN IX

Question 378

Milrinone is a _____ inhibitor that leads to decreased degradation of cAMP which results in increased contractility, vasodilation, _____ preload, and ____ afterload

Answer 378

PDE-3 inhibitor; decreased preload; decreased afterload

Question 379

________ is an inborn error of methionine metabolism, usually autosomal recessive deficiency in __________ enzyme (requires B6 cofactor) resulting in ectopia lentis, intellectual disability, marfanoid habitus, and risk of thromboembolic events

Answer 379

Homocystinuria; cystathionine beta synthase

Question 380

Vitamin B1 deficiency characterized by muscle wasting, hyporeflexia, decreased vibration and proprioception, and signs of heart failure

Answer 380

Beriberi

Question 381

Vasculitide associated with polymyalgia rheumatica

Answer 381

Giant cell arteritis

Question 382

Most common heart abnormality with fragile X syndrome

Answer 382

MVP

Question 383

Enzyme that breaks down triglycerides in chylomicrons and VLDL

Answer 383

Lipoprotein lipase

Question 384

Enzyme that breaks down triglycerides in adipose

Answer 384

Hormone-sensitive lipase

Question 385

Apolipoprotein that activates lecithin acyltransferase; found on HDL and chylomicrons

Answer 385

A-I

Question 386

Apolipoprotein that facilitates chylomicron secretion

Answer 386

ApoB48

Question 387

Apolipoprotein that facilitates uptake of chylomicron remnants; found on IDL but not LDL

Answer 387

ApoE

Question 388

Cystinuria is associated with defective reabsorption of ____, _____, _____, and ______ leading to hexagonal urine crystals and staghorn calculi

Answer 388

COAL Cystine, ornithine, arginine, lysine

Question 389

Vitamin deficiency with angular stomatitis, palpebritis, cheilosis, glossitis

Answer 389

Vitamin B2 def

Question 390

Mycoplasma pneumoniae has a triple-layered bacterial membrane containing sterols; what is the tx?

Answer 390

Ethambutol | Macrolide

Question 391

In utero exposure to lithium classically causes what fetal congenital heart defect?

Answer 391

Ebstein anomaly — tricuspid valve insufficiency

Question 392

________ syndrome affects capillary-sized blood vessels leading to port wine stain, leptomeningeal angiomatosis, seizures, and glaucoma

Answer 392

Sturge-weber

Question 393

3 major maninfestations of chronic chagas disease

Answer 393

Secondary achalasia Megacolon Dilated cardiomyopathy

Question 394

Hyperacute transplant rejection is what type of HSR?

Answer 394

Type II — due to preformed antidonor antibodies

Question 395

PDE inhibitor that inhibits platelet aggregation and acts as a direct arterial vasodilator; used to treat symptomatic peripheral artery disease (e.g., claudication)

Answer 395

Cilostazol

Question 396

Which antifungal is associated with renal toxicity manifesting as electrolyte abnormalities — hypokalemia, hypomagnesemia — as well as decreased EPO and n/n anemia?

Answer 396

Amphotericin B

Question 397

The concentrations of PAH, creatinine, inulin, and urea ______ as you travel along the kidney tubule

Answer 397

Increase [the concentrations of bicarb, glucose, and amino acids decrease]

Question 398

Metabolic acidosis leads to renal ammoniagenesis — in which renal epithelial cells metabolize ______ to generate ammonium and bicarb. The ammonium is then excreted in urine and bicarb is reabsorbed to buffer the blood

Answer 398

Glutamine

Question 399

Budding yeast with polysaccharide capsule

Answer 399

Cryptococcus neoformans

Question 400

Thick walled spherules packed with endospores

Answer 400

Coccidioides immitis

Question 401

Percentage of data included in 1, 2, and 3 standard deviations

Answer 401

1 SD = 68% 2 SD = 95% 3 SD = 99.7%

Question 402

Condition characterized by segmental, transmural inflammation of arterial wall with fibrinoid necrosis; associated with hepatitis B

Answer 402

Polyarteritis nodosa

Question 403

Differentiate topoisomerase I vs. topoisomerase II and give examples of chemotherapeutic inhibitors

Answer 403

Topoisomerase I induces single stranded breaks — inhibited by irenotecan and topotecan Topoisomerase II induces double stranded breaks — inhibited by etoposide (used in testicular and small cell lung ca)

Question 404

Thioamides methimazole and PTU inhibit thyroid peroxidase with what effects?

Answer 404

Decreased iodine organification and coupling of iodotyrosinases [PTU also inhibits peripheral conversion]

Question 405

Antibiotic that depolarizes cell membrane by creating transmembrane channels; primary adverse effect is myopathy (increased CPK)

Answer 405

Daptomycin

Question 406

Protozoan cause of watery (secretory) diarrhea that can be life-threatening in immunocompromised pts; dx by acid-fast stain showing cystic organisms and histological appearance of villous blunting, inflammatory infiltrate in LP, and basophilic cysts lining brush border of mucosal surface

Answer 406

Cryptosporidium parvum

Question 407

NRTI that is a thymidine analog that does not have a 3’OH group, so once added into DNA, synthesis is terminated

Answer 407

Zidovudine

Question 408

Mydriasis, abd pain, diarrhea, piloerection, lacrimation, yawning = _____ withdrawal

Answer 408

Opioid

Question 409

Young obese woman with daily headache that worsens with valsalva; b/l papilledema and transient visual disturbance d/t optic n. compression and impaired axoplasmic flow

Answer 409

Idiopathic intracranial HTN (pseudotumor cerebri)

Question 410

Rubella is in what family of viruses?

Answer 410

Togavirus [both rubella and rubeola (paramyxovirus) cause a rash that starts on the face and spreads down, but RUBELLA spreads faster and does not coalesce; also RUBELLA is more commonly associated with postauricular/occipital LAD]

Question 411

Rubeola is in what family of viruses?

Answer 411

Paramyxovirus

Question 412

Difference between concentric and eccentric LVH

Answer 412

Concentric = caused by pressure overload (chronic HTN, aortic stenosis); sarcomeres added in parallel Eccentric = caused by volume overload (AR, MR, ischemia, dilated cardiomyopathy); sarcomeres added in series

Question 413

Insulin resistance may occur d/t TNF alpha, catecholamines, glucocorticoids, and glucagon via phosphorylation of ____ or _____ residues of the insulin receptor

Answer 413

Serine; threonine

Question 414

Aortic arch associated with true aortic arch and subclavian aa.

Answer 414

Arch 4

Question 415

Aortic arch associated with pulmonary aa. and ductus arteriosus

Answer 415

Arch 6

Question 416

Selective peripheral D1 agonist used in hypertensive emergency, especially in pts with renal insufficiency; causes arteriolar dilation, increases renal perfusion, and promotes diuresis and natriuresis

Answer 416

Fenoldopam

Question 417

Segmented dsRNA virus that causes watery diarrhea with villous blunting, increased secretory crypt cells, and loss of brush border enzymes

Answer 417

Rotavirus

Question 418

Pharmacologic tx for portal HTN

Answer 418

Somatostatin and octreotide inhibit release of glucagon and VIP —> indirectly reduce portal blood flow Vasopressin —> direct splanchnnic vasoconstriction

Question 419

Lowest osmolarity (aka most dilute) segment of nephron

Answer 419

DCT [CD is most concentrated]

Question 420

Psychiatric condition in which neurologic symptoms are incompatible with known disease

Answer 420

Conversion disorder

Question 421

2nd gen antipsychotic that is the drug of choice for tx-resistant schizophrenia; AEs include agranulocytosis, seizures, myocarditis, and metabolic syndrome

Answer 421

Clozapine

Question 422

A stroke affecting which of the following arteries is associated with upper extremity problems, homonymous hemianopia, aphasia, and hemineglect? ``` A. ACA B. PCA C. PICA D. MCA E. AICA ```

Answer 422

D. MCA

Question 423

A stroke affecting which of the following arteries is associated with UMN signs and weakness affecting contralateral LE? ``` A. ACA B. PCA C. PICA D. MCA E. AICA ```

Answer 423

A. ACA

Question 424

A stroke affecting which of the following arteries is associated with contralateral hemiparesis (weakness in face, arm, leg) ``` A. ACA B. PCA C. PICA D. MCA E. AICA ```

Answer 424

B. PCA

Question 425

A stroke affecting which of the following arteries is associated with dysphagia, hoarseness, vestibulocerebellar symptoms? ``` A. ACA B. PCA C. PICA D. MCA E. AICA ```

Answer 425

C. PICA

Question 426

Women < 55 presenting with resistant HTN and CNS involvement (HA, TIA, stroke, aneurysm), fibromusclar webs alternating with areas of aneurysmal dilation, loss of internal elastic lamina, and renal artery stenosis

Answer 426

Fibromuscular dysplasia

Question 427

Antibodies associated with polymyositis

Answer 427

Anti-Jo-1 [anti-tRNA synthetase]

Question 428

Decorticate vs. decerebrate posturing

Answer 428

Decorticate = flexor — damage to neural structures above red nucleus (cerebral hemispheres, internal capsule) Decerebrate = extensor — damage to brainstem at or below level of red nucleus (midbrain tegmentum, pons)

Question 429

________ syndrome presents with infertility, gynecomastia, long lower extremities, and 47,XXY genotype. It is the most common cause of male hypogonadism and is characterized by progressive destruction and hyalinization of the seminiferous tubules, leading to small, firm testes. Serum inhibin levels are ______, testosterone levels are ______, FSH levels are ______, and LH levels are ______

Answer 429

Klinefelter Decreased; decreased; increased; increased

Question 430

Regardless of the patient’s hydration status, the majority of water reabsorption in the nephron occurs in the _________

Answer 430

Proximal tubule

Question 431

Serum albumin levels, serum bilirubin levels, and _________ are lab values reflective of liver function and are of greatest prognostic significance in patients with cirrhosis

Answer 431

Prothrombin time

Question 432

Large, sporulating gram-positive rod that is encased in an antiphagocytic polypeptide capsule composed of D-glutamic acid

Answer 432

Bacillus anthracis

Question 433

How does digoxin cause a reduction in heart rate?

Answer 433

By increasing parasympathetic tone, which leads to inhibition of AV nodal conduction

Question 434

Alpha 2 adrenergic receptors ______ insulin secretion, and beta 2 adrenergic receptors _______ insulin secretion. The _________ effect is generally predominant

Answer 434

Inhibit; stimulate Alpha 2

Question 435

Autosomal recessive disorder resulting from a defect in DNA-repair genes, making them hypersensitive to ionizing radiations. Manifestations include cerebellar ataxia, oculocutaneous telangiectasias, repeated sinopulmonary infections, and increased incidence of malignancy

Answer 435

Ataxia-telangiectasia

Question 436

Alzheimer disease has a strong genetic predisposition. What 3 gene mutations are associated with early-onset Alzheimers, and what genotype is associated with late-onset Alzheimers?

Answer 436

Early onset = APP (Chr21), presenilin 1 (Chr14), and presenilin 2 (Chr1) — thought to promote the production of A-beta-amyloid Late onset = apolipoprotein E4 genotype

Question 437

Renal clearance of which of the following would DECREASE following a dose of desmopressin? ``` A. Calcium B. Creatinine C. Glucose D. PAH E. Urea ```

Answer 437

E. Urea [Vasopressin and Desmopressin cause a V2 receptor-mediated increase in water and urea permeability at the inner medullary collecting duct. The resulting rise in urea reabsorption (decreased urea clearance) enhances the medullary osmotic gradient, allowing the production of maximally concentrated urine]

Question 438

Protein defect, elevated lipoproteins, and major manifestations for familial chylomycronemia (hyperlipoproteinemia type I)

Answer 438

Defect in lipoprotein lipase and ApoC-II Elevated chylomicrons Major manifestations = acute pancreatitis, lipemia retinalis, eruptive skin xanthomas, hepatosplenomegaly

Question 439

Protein defect, elevated lipoproteins, and major manifestations for familial cholesterolemia (hyperlipoproteinemia type II A)

Answer 439

Defect in LDL receptor and ApoB100 Elevated LDL Major manifestations = premature coronary artery disease, corneal arcus, TENDON xanthomas, and XANTHELASMAS

Question 440

Protein defect, elevated lipoproteins, and major manifestations for familial dysbetalipoproteinemia (hyperlipoproteinemia type III)

Answer 440

Defect in ApoE Elevated Chylomicron and VLDL remnants Major manifestations = premature coronary artery disease and peripheral vascular disease, tuboeruptive and PALMAR xanthomas

Question 441

Protein defect, elevated lipoproteins, and major manifestations for familial hypertriglyceridemia (hyperlipoproteinemia type IV)

Answer 441

Defect in ApoA-V Elevated VLDL Major manifestations = increased pancreatitis risk, associated with obesity and insulin resistance

Question 442

Autosomal dominant disease characterized by pigmented mucocutaneous macules and numerous hamartomatous polyps in the GI tract; usually benign but can present with abdominal pain due to intussusception, obstruction, or malignant transformation

Answer 442

Peutz-Jeghers syndrome [mutations in serine/threonine kinase 11 (STK11) gene on Chr 19]

Question 443

Wernicke encephalopathy is primarily associated with atrophy of the mammillary bodies. What is the classic triad it presents with?

Answer 443

Encephalopathy Oculomotor dysfunction (i.e., nystagmus) Ataia [Contrast with alcoholic cerebellar degeneration, which is due to loss of purkinje cells in the cerebellar vermis, leading to gait ataxia, truncal instability, and a rhythmic postural tremor of the fingers and hands]

Question 444

What type of diabetes insipidus is associated with Lithium use?

Answer 444

Nephrogenic diabetes insipidus [Lithium impairs aquaporin-2 water channels and reduces responsiveness to endogenous and exogenous vasopressin]

Question 445

A systolic murmur that increases in intensity with maneuvers that DECREASE LV blood volume is highly suggestive of hypertrophic cardiomyopathy. HCM is characterized by LV outflow obstruction that increases afterload and decreases cardiac output. The hypertrophy also leads to a small LV cavity and impaired relaxation of the LV walls with consequent diastolic dysfunction. The hypertrophied LV walls have high O2 demand that can exceed O2 supply and lead to exertional angina. T/F: HCM is associated with normal coronary arteries

Answer 445

True

Question 446

Concomitant family history of colon and endometrial cancer in first-degree relatives strongly suggests ________ syndrome, a ______ ______ inherited cancer syndrome that markedly increases the risk of colorectal, endometrial, ovarian, and other cancers. It is the second most common cause of hereditary ovarian cancer (after BRCA gene mutations), and it is the most common inherited cause of colon cancer. It is caused by a germline mutation involving mismatch repair genes, leading to _______ instability

Answer 446

Lynch; autosomal dominant; microsatellite

Question 447

Alkaptonuria is an autosomal recessive disorder due to a defect in homogentisic dioxygenase. Clinical features include darkening of urine after exposure to air, blue-black discoloration of cartilage and skin, and debilitating ____________

Answer 447

Osteoarthropathy

Question 448

Which of the following is most likely increased in the extracellular space of a region affected by ischemia? ``` A. Na+ B. Cl- C. K+ D. Ca++ E. HCO3- ```

Answer 448

C. K+ [all others decrease in extracellular concentration; intracellular accumulation of Ca++ is a hallmark of ischemic injury]

Question 449

In a normal mammalian kidney, densely immunostaining, protein-containing cells adjacent to the renal glomerulus are most likely ____________

Answer 449

JG cells in the JG apparatus

Question 450

A test is performed in which multiple wells containing mixtures of ethanol and amniotic fluid are shaken and then examined to find the highest value well that contains a ring of stable foam. What does this ring of stable foam represent?

Answer 450

Surfactant

Question 451

Marfanoid body habitus is defined by pectus deformity, tall stature, arachnodactyly, joint hyperlaxity, skin hyperelasticity, and scoliosis. The differential diagnosis includes Marfan syndrome, which is an autosomal dominant condition with distinguishing features including normal intellect, aortic root dilation, and upward lens dislocation. Also on the differential diagnosis is ________, an autosomal RECESSIVE mutation in the gene encoding _____________, resulting in intellectual disability, hypercoagulability, DOWNWARD lens dislocation, megaloblastic anemia, and a fair complexion

Answer 451

Homocystinuria; cystathionine-beta-synthase (CBS) [CBS is essential for degradation of methionine, and deficiency leads to buidup of both methionine and homocysteine]

Question 452

Heparin is a safer choice than warfarin in pregnancy because of: ``` A. High lipid solubility B. High water solubility C. Higher albumin binding D. Higher Vd E. Slow onset of action ```

Answer 452

B. High water solubility [rule of thumb — water soluble materials do not readily cross the placenta while lipophilic materials do!]

Question 453

________ describes the mixing of genomic segments in segmented viruses that infect the same host cell. This results in major antigenic shifts are are responsible for pandemics and epidemics of Influenza A. ________ refers to gene exchange that occurs through the crossing over of 2 dsDNA molecules. The resulting progeny can have recombined genomes with traits not present simultaneously in either parent virus

Answer 453

Reassortment Recombination

Question 454

Lesions causing cyanotic congenital heart disease (5 Ts)

Answer 454

``` Tetralogy of Fallot Truncus arteriosus Transposition of the great arteries Total anomalous pulmonary venous connection Tricuspid atresia ```

Question 455

New mucosal intestinal epithelial cells differentiate from stem cells residing in what histological layer?

Answer 455

Crypts of Lieberkuhn

Question 456

A pt with chronic hepatitis B has a liver biopsy which shows spherical nodules within the confines of fibrous septae. The nodules are composed of what proliferating cell type?

Answer 456

Hepatocytes

Question 457

What is the mechanism causing tardive dyskinesia in the sitting of long-term use of antipsychotics?

Answer 457

Dopamine receptor upregulation due to long-term blockade of these receptors in the nigrostriatal dopamine pathway

Question 458

A congenital absence of dopamine beta-hydroxylase will impair synthesis of ______ and _______. Infants and small children may present with hypotension, ptosis, and hypothermia. Adults often present with postural/orthostatic hypotension, exercise intolerance, nasal congestion, and ejaculatory difficulties

Answer 458

Norepinephrine; epinephrine

Question 459

Massive pulmonary emboli (e.g. saddle embolus) with significant occlusion of both pulmonary arteries causes _______ shock. Thus in the setting of shock due to saddle embolus, central venous pressure will ________, cardiac output will ________, and systemic vascular resistance will _________

Answer 459

Obstructive Increase; decrease; increase

Question 460

Morphology and mechanism for adenovirus replication

Answer 460

dsDNA Utilize DNA-dependent DNA polymerase to replicate in the nucleus

Question 461

A major cause of postural hypotension is insufficient stimulation of __________ receptors upon standing

Answer 461

Alpha1 adrenergic

Question 462

Psoriasis is characterized by hyperkeratosis and epidermal hyperplasia. In predisposed pts, disruption of the normal skin barrier leads to activation of ________ cells, which induces recruitment and differentiation of _______ cells. The resulting inflammatory response stimulates local keratinocyte proliferation and production of antimicrobial peptides and inflammatory cytokines, leading to a self-amplifying inflammatory loop

Answer 462

Dendritic; CD4+ T cells (primarily Th17 and Th1)

Question 463

Medical therapy for weight loss is recommended for pts who are unable to lose weight with dietary modification and exercise and are obese, or overweight with weight-related complications. One potential medication is _______, which is an intestinal lipase inhibitor that reduces absorption of dietary fat. It has significant GI side effects including diarrhea, fecal incontinence, and oily spotting.

Answer 463

Orlistat

Question 464

Cancer of the rectum would spread hematogenously to the liver via what veinous pathway?

Answer 464

Rectum —> superior rectal v. —> inferior mesenteric v. —> portal venous system [note that the rectum ends at the dentate line; after the dentate line is the anus, which is drained by middle and inferior rectal vv. which drain into systemic circulation via the internal iliac v.]

Question 465

Insulin increases the intracellular concentration of which of the following? ``` A. 2,3 BPG B. 3-hydroxybutyrate C. Fructose-1-phosphate D. Fructose-2,6-bisphosphate E. Lactate ```

Answer 465

D. Fructose-2,6-bisphosphate Insulin and glucagon regulate glucose metabolism via the bifunctional PFK-2/F-2,6-BPase enzyme complex. Insulin activates the PFK-2 domain, which converts F-6P to F-2,6-BP, which then activates PFK-1, increasing the production of F-1,6-BP and driving the cell toward glycolysis. Glucagon activates F-2,6-BPase, which degrades F-2,6-BP, favoring gluconeogenesis

Question 466

Name the nonpolar/hydrophobic amino acids

Answer 466

``` Alanine Valine Leucine Isoleucine Phenylalanine Tryptophan Methionine Proline Glycine ``` [hydrophilic include arginine, histidine, lysine, aspartate, glutamate]

Question 467

Probenecid can be used to enhance penillin’s efficacy in certain clinical settings like penicillin resistance, gonorrhea, or neurosyphilis. What is the MOA of probenecid?

Answer 467

Blocks organic anion transporters on renal tubular cells to inhibit tubular secretion of certain antibiotics (e.g., penicillin)

Question 468

Cough syncope typically occurs in overweight male patients with COPD. What causes “cough syncope”?

Answer 468

Increased intrathoracic pressure during a coughing episode —> decreased venous return to the heart —> transient decrease in cardiac output and cerebral perfusion

Question 469

Morphology and location of replication of orthomyxovirus

Answer 469

Segmented, negative-sense, ssRNA Unique among RNA viruses in that it is the only one (other than retroviruses) that replicates in the nucleus

Question 470

A newborn with normal blood glucose, hyperammonemia, and increased urinary orotic acid most likely has a ________________ deficiency, the most common urea cycle disorder. Because of its location in the pathway, defects in this enzyme result in accumulation of orotic acid (an alternate metabolite of carbamoyl phosphate produced by the pyrimidine biosynthetic pathway) and decreased ________ production

Answer 470

Ornithin transcarbamylase (OTC) deficiency Citrulline

Question 471

Patients with 17-alpha hydroxylase deficiency present with lack of pubertal development and HTN due to insufficient production of sex hormones and cortisol, and overproduction of mineralocorticoids (deoxycorticosterone and corticosterone). What changes would be seen in LH, ACTH, and renin?

Answer 471

LH increases ACTH increases Renin decreases

Question 472

Inheritance pattern of medium-chain acyl-coA dehydrogenase (MCAD) deficiency

Answer 472

Autosomal recessive [note that heterozygotes have reduced enzyme function, while full disease manifestations of hypoketotic hypoglycemia are present in homozygotes]

Question 473

In acute respiratory distress syndrome, hypoxemia results from ventilation-perfusion mismatch; this is largely due to __________ physiologic shunting as the fluid-filled, nonventilated alveoli continue to receive blood. In addition, formation of microthrombi results in inadequate perfusion of the remaining well-ventilated alveoli, causing _______ physiologic dead space

Answer 473

Right-to-left; increased

Question 474

2 HIV antiretrovirals that act as allosteric RT inhibitors, inhibiting HIV DNA synthesis from RNA template by terminating DNA chain elongation

Answer 474

Efavirenz Nevirapine [NNRTIs]

Question 475

5 HIV antiretrovirals that act as competitive nucleoside/nucleotide RT inhibitors, thus inhibiting HIV DNA synthesis from RNA template by terminating DNA chain elongation

Answer 475

``` Tenofovir Abacavir Emtricitabine Lamivudine Zidovudine ``` [NRTIs]

Question 476

4 HIV antiretrovirals that inhibit HIV polyprotein cleavage

Answer 476

Atazanavir Darunavir Indinavir Ritonavir [protease inhibitors]

Question 477

2 HIV antiretrovirals that inhibit HIV DNA integration into host genome

Answer 477

Dolutegravir Raltegravir [integrase inhibitors]

Question 478

HIV antiretroviral that inhibits HIV fusion with target cell membrane by binding to HIV gp41

Answer 478

Enfuvirtide [fusion inhibitor]

Question 479

What is the difference between fibroadenoma and fibrocystic change in the breast?

Answer 479

Fibroadenoma = common estrogen-sensitive benign breast tumor in young women; typically presents as solitary nontender, firm, well-demarcated, spherical, and mobile nodule corresponding to an encapsulated proliferation of stromal and ductal elements Fibrocystic changes = most common cause of palpable nodular changes in breast; generally present as poorly defined, diffuse increase in cysts and fibrotic tissue THROUGHOUT; lesions are often numerous and PAINFUL, with maximal tenderness during the premenstrual phase

Question 480

Biopsy of a skin lesion demonstrates dermoepidermal junction aggregates of large cells that fuse with adjacent nests. The individual atypical cells have irregular nuclear contours, hyperchromasia, and are round or spindle shaped. A mutation of chromosome 9p21 is identified in atypical cells. This patient is most likely predisposed to which of the following? ``` A. Dermatofibrosarcoma protruberans B. Malignant fibrous histiocytoma C. Basal cell carcinoma D. Melanoma E. Neurofibroma ```

Answer 480

D. Melanoma [Histology described is a dysplastic nevus. Although most dysplastic nevi are clinically stable, some have the potential to evolve into melanoma. Mutations in the CDKN2A gene on chromosome 9p21 are associated with Dysplastic Nevi Syndrome]

Question 481

Embryologic brain precursor of cerebral hemispheres and lateral ventricles

Answer 481

Telencephalon [Prosencephalon divides into telencephalon and diencephalon]

Question 482

Embryologic brain precursor of midbrain and aqueduct

Answer 482

Mesencephalon

Question 483

During embryologic development, the rhombencephalon divides into the ___________ (which later forms the pons, cerebellum, and upper 4th ventricle) and the __________ (which later forms the medulla and lower 4th ventricle)

Answer 483

Metencephalon; myelencephalon

Question 484

Carbon dioxide is utilized in the de novo synthesis of pyrimidine and purine nucleobases. The first reaction for both of these processes occurs in the ______

Answer 484

Cytosol [for pyrimidines this invovles glutamine, CO2, and 2 molecules of ATP used to form carbamoyl phosphate via carbamoyl phosphate synthetase II. After initial synthesis in the cytosol, purine and pyrimidine nucleotides are utilized for DNA synthesis in the nucleus]

Question 485

Some antifungals act at the cell membrane, while some act at the cell wall. Cell membrane active agents include amphotericin B, nystatin, and azoles. What class of antifungals function by inhibiting CELL WALL synthesis?

Answer 485

Echinocandins (caspofungin)

Question 486

Complete molar pregnancy is an abnormal proliferation of ______ and ________ without fetal tissue. Due to paternal imprinting, staining with p57 is _________

Answer 486

Cytotrophoblasts; syncytiotrophoblasts; negative

Question 487

_________ is preferentially expressed in the liver and pancreatic beta cells, where it plays an important regulatory role in glycogen synthesis and insulin secretion, respectively. Mutations that impair expression of this enzyme raise the glucose threshold required for insulin release, leading to maturity-onset diabetes of the young (MODY)

Answer 487

Glukokinase

Question 488

CYP450 inhibitors

Answer 488

``` Acetaminophen/NSAIDs Antibiotics/antifungals (azoles) Amiodarone Cimetidine Cranberry juice, Gingko biloba, Vit E Omeprazole Thyroid hormone SSRIs (fluoxetine) ```

Question 489

CYP450 inducers

Answer 489

``` Carbamazepine, phenytoin Ginseng, St. John’s wort Oral contraceptives Phenobarbital Rifampin ```

Question 490

Gram negative rods may be cultured on MacConkey agar. Lactose fermenters form pink colonies, while non-lactose fermenters form white colonies. The lactose fermenters can be categorized based on fermentation speed. What are the fast fermenters vs. slow fermenters?

Answer 490

Fast = Klebsiella, E.coli, Enterobacter Slow = Citrobacter, Serratia

Question 491

Gram negative rods may be cultured on MacConkey agar. Lactose fermenters form pink colonies, while non-lactose fermenters form white colonies. The non-lactose fermenters can be further categorized based on whether they are oxidase positive or negative. If oxidase positive, it is ____________. If oxidase negative and there is no H2S production, it is _________. If oxidase negative and there is H2S production (black color), it is either _______ or ________

Answer 491

Pseudomonas; Shigella; Salmonella; Proteus

Question 492

How would the following parameters change in hypovolemic shock: arterial baroreceptor firing rate, systemic vascular resistance, pulmonary vascular resistance, and systemic capillary fluid transfer (filtration vs absorption)?

Answer 492

Decrease in arterial baroreceptor firing rate Increase in systemic vascular resistance Increase in pulmonary vascular resistance Systemic capillary fluid transfer favors absorption

Question 493

A young female presents with intermittent diarrhea, nausea, and a 4lb weight loss over the past month. Physical exam reveals a migrating serpiginous pruritic rash around the anus. WBC is 8000 with 19% eosinophils. Which of the following will most likely reveal the diagnosis? ``` A. KOH prep B. Skin biopsy C. Bone marrow biopsy D. Peripheral smear E. Stool microscopy ```

Answer 493

E. Stool microscopy

Question 494

A female presents with an ovarian mass and signs of virulization including hirsutism, male pattern baldness, breast atrophy, clitoral enlargement, and amenorrhea (last period was 5 months ago). What type of ovarian tumor is most likely?

Answer 494

Sertoli-Leydig cell tumor

Question 495

A patient who has overdosed on aspirin would most likely show what changes in their serum HCO3, arterial pH, and blood PCO2?

Answer 495

All decreased

Question 496

Vasopressin signaling occurs via _________

Answer 496

GPCR [V1 is Gq linked, and results in increased vascular smooth muscle contraction. V2 is Gs linked and results in increased H2O permeability and reabsorption via upregulation of aquaporin-2 in the collecting tubules of the kidney, as well as increased release of vWF]

Question 497

2 y/o male presents with developmental delay, small stature with large head, irritability, poor eye contact, and flapping of the hands. Which of the following is the most likely cause? ``` A. Creation of alternative splice site B. Trinucleotide repeat expansion C. Frameshift mutation D. Missense mutation E. Nonsense mutation ```

Answer 497

B. Trinucleotide repeate expansion

Question 498

Which of the following is true of RSV? A. DNA genome B. Double-stranded genome C. Mature virion lacking viral polymerase D. Mediation of cell entry via a fusion protein E. Viability on surfaces for several weeks

Answer 498

D. Mediation of cell entry via a fusion protein RSV (and all of the paramyxovirus family) contain surface F protein which causes respiratory epithelial cells to fuse and form multinucleated cells. Pavilizumab is a preventative monoclonal antibody against this fusion, used in premature infants

Question 499

T/F: administration of Rho(D) immune globulin prevents formation of antibodies to RhD in a Rh-negative mother

Answer 499

True

Question 500

A pt with a history of HTN and CKD on dialysis presents with SOB and confusion. EKG shows low voltage and electrical alternans, indicating possible pericardial effusion. What changes would be seen in BP, pulse, JVP, and pulsus paradoxus?

Answer 500

BP decreased Pulse increased (low voltage, electrical alternans, and tachycardia are classic triad of pericardial effusion) JVP increased Pulsus paradoxus increased

Question 501

Shoulder pain is reproduced with external rotation against resistance. Along with teres minor, what other muscle tendon is likely inflamed?

Answer 501

Infraspinatus

Question 502

Which of the following is used in the treatment of idiopathic chronic constipation? ``` A. Azathioprine B. Infliximab C. Lubiprostone D. Mesalamine E. Sulfasalazine ```

Answer 502

C. Lubiprostone [PGE1 derivative; activates chloride channels on the apical side of GI epithelial cells]

Question 503

Inheritance of DMD

Answer 503

X-linked disorder typically due to frameshift deletions or nonsense mutations [female carrier status is uncertain due to random X inactivation]

Question 504

A week old breast-fed male presents with poor weight gain, irritability, vomiting, jaundice, and hepatomegaly. A reducing substance test of the urine is positive, and a glucose oxidase result is negative. Which of the following is most likely present at increased concentrations in the liver? A. Fructose 1,6-bisphosphate B. Galactose 1-phosphate C. Glucose 1-phosphate D. Glucose 6-phosphate

Answer 504

B. Galactose 1-phosphate

Question 505

Circular dsDNA virus that affects transplant patients (potentially leading to allograft rejection), and commonly targets the kidneys

Answer 505

BK virus (a polyomavirus)

Question 506

Inheritance of cystic fibrosis

Answer 506

Autosomal recessive

Question 507

Squamous cell carcinoma at the apex of the tongue is most likely to spread to what lymph nodes first?

Answer 507

Submental

Question 508

A malignant anal mass below the dentate line is discovered. Which of the following lymph nodes should be evaluated first? ``` A. Internal iliac B. Popliteal C. Sacral D. Superficial inguinal E. Superior rectal ```

Answer 508

D. Superficial inguinal

Question 509

Abrupt onset gross hematuria in an otherwise healthy patient with a family history of sickle cell disease suggests a diagnosis of ___________________ due to underlying sickle cell trait.

Answer 509

Renal papillary necrosis [Conditions associated with RPN include SCD/trait, analgesic nephropathy, diabetes, pyelonephritis, and UTI]

Question 510

Viral cause of meningitis that may present with neuroinvasive disease characterized by asymmetric flaccid paralysis and/or parkinsonian features

Answer 510

West Nile Virus (ssRNA flavivirus)

Question 511

A patient sustains an injury to the arm when tackled mid-throw during a football game. On PE, there is flattening of the deltoid muscle and insensitivity of the overlying skin to pinprick. Peripheral pulses are intact. Which of the following is responsible? ``` A. AC joint subluxation B. Anterior dislocation of the humerus C. Posterior dislocation of the humerus D. Clavicular fracture E. Fracture of the coracoid process ```

Answer 511

B. Anterior dislocation of the humerus [Anterior dislocations are the most common, classically following a blow to an externally rotated and abducted arm (e.g., throwing a football). Results in flattening of deltoid prominence, protrusion of the acromion, and anterior axillary fullness]

Question 512

Absence of CD55 and CD59 on RBCs, hemolytic anemia, pancytopenia, thrombosis at atypical sites, and hemosiderosis (iron deposition in kidneys) indicate what diagnosis?

Answer 512

Paroxysmal nocturnal hemoglobinuria

Question 513

________ leprosy is associated with cell-mediated immunity (Th1 response) and a positive lepromin skin test _________ leprosy is associated with humoral immunity (Th2 response) and a negative lepromin skin test

Answer 513

Tuberculoid Lepromatous

Question 514

First-line pharmacotherapy for moderate-to-severe alcohol use disorder; works by preventing the reinforcing effects of alcohol use

Answer 514

Naltrexone — mu opioid antagonist [Another option is Acamprosate, which modulates glutamate neurotransmission at the NMDA receptor. Disulfuram is considered second-line due to poorer efficacy and dependence on supervised administration]

Question 515

Propionic acidemia is an autosomal recessive congenital deficiency in propionyl-CoA carboxylase, the enzyme responsible for conversion of propionyl-CoA to methylmalonyl-CoA. Deficiency results in excess propionic acid accumulation in the blood, causing severe metabolic acidosis. Hypoglycemia and ketosis frequently develop secondary to the acidosis. Affected patients present 1-2 weeks after birth with lethargy, poor feeding, vomiting, and hypotonia. Treatment involves starting a low-protein diet containing minimal amounts of what 4 amino acids?

Answer 515

Valine Isoleucine Methionine Threonine

Question 516

Most common cause of spontaneous lobar hemorrhage, particularly in the elderly; most common sites of hemorrhage include occipital and parietal lobes

Answer 516

Cerebral amyloid angiopathy

Question 517

Nonrhythmic conjugate eye movements and involuntary jerking movements of the trunk and limbs are features of opsoclonus-myoclonus syndrome, a paraneoplastic syndrome associated with ________, which is the most common extracranial solid neoplasm in children. The tumor typically arises from the _________ cells of the adrenal medulla and presents with an abdominal mass and elevated catecholamine breakdown products

Answer 517

Neuroblastoma; neural crest cells

Question 518

Major virulence factor of haemophilus influenzae type b is the polysaccharide capsule composed of ______ _______, which protects against phagocytosis and complement-mediated lysis by binding _________, a circulating regulator protein that normally prevents complement (C3b) deposition on host cells

Answer 518

Polyribosylribitol phosphate (PRP); factor H [the Hib vaccine is composed of PRP conjugated to a protein toxoid]

Question 519

Initiation of allopurinol would increase activity of which of the following? ``` A. Azathioprine B. Ganciclovir C. Prednisone D. Tacrolimus E. Trimethoprim ```

Answer 519

A. Azathioprine [allopurinol competitively inhibits xanthine oxidase, resulting in increased conversion of azathioprine to its active metabolite via HGPRT]

Question 520

What location is pacing the ventricles in a third degree AV block?

Answer 520

The AV node [in third degree block, the atria and ventricles are paced independently. The SA node paces the atria, while the AV node paces the ventricles]

Question 521

What 2 classes of antibiotics cause QT prolongation?

Answer 521

Macrolides Fluoroquinolones [other medication-induced causes include odansetron, azoles, antipsychotics, TCAs, class IA antiarrhythmics, class III antiarrhythmics]

Question 522

How does Crohn disease cause oxalate kidney stones?

Answer 522

Impaired bile absorption in the terminal ileum leads to loss of bile acids in stool with subsequent fat malabsorption. Intestinal lipids then bind calcium ions, and the resulting soap complex is excreted. Free oxalate (normally bound by calcium to form an unabsorbable complex) is absorbed and forms urinary calculi

Question 523

Electrolyte abnormality associated with Legionella

Answer 523

Hyponatremia

Question 524

A normal alveolar to arterial oxygen gradient is 5-15 mm Hg. What are 2 major causes of hypoxemia in the setting of a normal A-a gradient?

Answer 524

Hypoventilation (obesity hypoventilation syndrome, neuromuscular disorders) Low inspired fraction of O2 (high altitude)

Question 525

A normal alveolar to arterial oxygen gradient is 5-15 mm Hg. What are 3 major causes of hypoxemia in the setting of an elevated A-a gradient?

Answer 525

Right-to-left shunt (cardiac septal defects, pulmonary edema) V/P mismatch (pulmonary embolism, COPD) Impaired diffusion (interstitial lung disease)

Question 526

Streptococcus pyogenes is differentiated from other beta-hemolytic strep in that it is _______-positive and ________-sensitive

Answer 526

Pyrrolidonyl arylamidase (PYR); bacitracin

Question 527

What is the mechanism behind inhaled amyl nitrite as the antidote for cyanide poisoning?

Answer 527

Nitrites are oxidizing agents that induce methemoglobinemia, which contains ferric (Fe3+) rather than ferrous (Fe2+) iron Cyanide binds to ferric iron more avidly than to mitochondrial cytochrome enzymes, diminishing cyanide’s toxic effect

Question 528

Glomerulonephritis, a photosensitive skin rash, and arthralgias in a young woman are suggestive of SLE. Up to 30% of pts with SLE have _______ antibodies, which cause paradoxical aPTT prolongation and a false positive RPR/VDRL. These pts are at increased risk for venous and arterial thromboembolism and unexplained, recurrent pregnancy loss

Answer 528

Antiphospholipid antibodies

Question 529

What virulence factor of E.coli is most important for its ability to cause UTI?

Answer 529

P fimbriae [other virulence factors it has are: LPS leading to shock, K1 capsular polysaccharide leading to neonatal meningitis, Verotoxin leading to bloody gastroenteritis, and heat-stable/heat labile enterotoxins leading to watery gastroenteritis]

Question 530

Diabetic neuropathy may involve CN III, leading to ptosis, down-and-out gaze, and normal light and accommodation reflexes. Which of the following describes the mechanism by which this occurs? A. Nerve compression B. Nerve ischemia C. Nerve inflammation

Answer 530

B. Nerve ischemia [central ischemia affects somatic nerve fibers but spares peripheral parasympathetic fibers, which is why the pupillary size and reactivity is normal in diabetic CN III mononeuropathy]

Question 531

What type of vaccine protects against tetanus, and what type of immunity does it generate?

Answer 531

Tetanus toxoid vaccine (formaldehyde-inactivated tetanus toxin) Stimulates a humoral antibody response (antitoxin antibodies)

Question 532

The major virulence factor of Streptococcus pyogenes is M protein, an alpha helical protein that shares structural homology with tropomyosin and myosin. What is the purpose of this virulence factor?

Answer 532

Inhibits phagocytosis, prevents complement binding, and aids in epithelial attachment [Antibodies against M protein form shortly after acute infection, and may cross react with epitopes on myosin, leading to rheumatic carditis]

Question 533

What are the Light criteria defining an EXUDATIVE effusion regarding pleural fluid protein:serum protein ratio AND pleural fluid LDH:serum LDH ratio?

Answer 533

Pleural fluid protein:serum protein ratio >0.5 Pleural fluid LDH:serum LDH ratio > 0.6 [Or pleural fluid LDH > 2/3 upper limit of normal serum LDH; causes of exudative infusion include infection like PNA, malignancy, and rheumatologic disease]

Question 534

Lesions of the macula result in which of the following? ``` A. Homonymous hemianopsia B. Binasal hemianopsia C. Bitemporal hemianopsia D. Arcuate scotomas E. Central scotomas ```

Answer 534

E. Central scotomas

Question 535

Congenital ________ presents with chorioretinitis, hydrocephalus, jaundice, hepatosplenomegaly, and a placenta infiltrated with crescent-shaped organisms. Most cases in pregnant women arise due to consumption of undercooked, contaminated meat

Answer 535

Toxoplasmosis [other mechanism of acquiring infection is incidental ingestion of oocytes from cat feces (felines are definitive host)]

Question 536

P.aeruginosa is a gram-negative, opportunistic pathogen with multiple mechanisms of antibiotic resistance, including beta-lactamases, efflux pumps, and antibiotic-modifying enzymes. Antibiotic-modifying enzymes add chemical groups (e.g., acetyl, adenyl, phosphate) to a target drug and are the most common mechanisms of resistance of what class of antimicrobial?

Answer 536

Aminoglycosides (e.g., gentamicin) [Altered aminoglycosides have a reduced ability to bind to the 16S ribosomal RNA within the 30S ribosomal subunit]

Question 537

The most susceptible vascular regions to atherosclerosis involve bends and branch points that encourage turbulent blood flow, which disrupts vascular wall integrity and leads to endothelial cell dysfunction. The hemodynamics of what 2 vascular beds make them most susceptible to atherosclerosis of all the major vascular beds in the body?

Answer 537

Lower abdominal aorta Coronary arteries

Question 538

Recovery from a subarachnoid hemorrhage may be complicated by delayed cerebral ischemia due to cerebral vasospasm, typically manifesting within 3-12 days after the initial incident with altered mental status and/or focal neurologic deficits. What pharmacologic agent improves outcomes by preventing or reducing the extent of these deficits?

Answer 538

Nimodipine, a selective calcium-channel blocker [neuroprotective effect is due to combo of increased cerebral vasodilation and decreased calcium-dependent excitotoxicity]

Question 539

Glucose transport protein GLUT-4 is an insulin-sensitive glucose transporter expressed in _________ and ___________ that translocates the plasma membrane in response to increasing insulin levels

Answer 539

Skeletal muscle cells; adipocytes [In contrast, GLUT-1, 2, 3, and 5 are always present in the plasma membrane and constitutively transport glucose in an insulin-independent manner]

Question 540

What type of colon cancer can produce large quantities of prostaglandin E2, resulting in increased mucin production and a secretory diarrhea characterized by watery, mucinous stools?

Answer 540

Villous adenomas [mucin is a potassium-rich glycoprotein, note that excess production can result in hypoproteinemia and hypokalemia]

Question 541

When comparing Th1 vs. Th2 differentiation: _______ are involved in the pathogenesis of UC. They produce IL-5 and IL-13 which contribute to inflammation and damage of intestinal mucosa. ______ are involved in Crohns disease. They produce IL-2 and IFN-y, promoting further T cell response, activation of macrophages, and differentiation of macrophages into giant cells. Th17 are a subset of this type, and contribute to cell injury in CD

Answer 541

Th2 Th1

Question 542

Most common trigger for DIC in pregnancy

Answer 542

Release of tissue factor from injured placenta (e.g., placental abruption) into maternal circulation

Question 543

AEs of mood stabilizers in bipolar disorder: Diabetes insipidus, hypothyroidism, tremor, and ebstein anomaly are associated with ________ Aplastic anemia, SIADH, and neural tube defects are associated with _____

Answer 543

Lithium Carbamazepine

Question 544

Excessive bleeding in a patient with ESRD is due in part to uremic toxins in circulation. How would the following parameters change in this bleeding disorder: PT, aPTT, platelet count, bleeding time

Answer 544

PT normal aPTT normal Platelet count normal Bleeding time prolonged

Question 545

Most common infectious agent causing fetal hydrops; mom often complains of transient arthralgias during pregnancy

Answer 545

Parvovirus B19 [naked ssDNA virus]

Question 546

Innervation of gluteus medius

Answer 546

Superior gluteal n

Question 547

What 2 features are required for a diagnosis of TTP?

Answer 547

MAHA | Thrombocytopenia

Question 548

What effects do ACE inhibitors have on GFR and serum K+?

Answer 548

Decreased GFR Hyperkalemia

Question 549

A 65 y/o man suffers an acute anterior MI. How would the following parameters change compared to a healthy man of the same age: systemic vascular resistance, pulmonary vascular reistance, pulmonary capillary wedge pressure

Answer 549

SVR increases PVR decreases PCWP increases

Question 550

The parotid duct passes through which of the following muscles to enter the oral cavity: ``` A. Buccinator B. Masseter C. Orbicularis oris D. Temporalis E. Zygomaticus major ```

Answer 550

A. Buccinator

Question 551

Commonly injured bones in a FOOSH include fracture of the ______ and/or dislocation of the ________ (which can present with acute carpal tunnel syndrome)

Answer 551

Scaphoid; lunate

Question 552

What class of HIV antiretrovirals is associated with lactic acidosis?

Answer 552

Nucleoside reverse transcriptase inhibitors

Question 553

Patients with osteogenesis imperfecta have an issue with what type of wound healing? ``` A. Cell migration B. Clot formation C. Granulation tissue deposition D. Inflammation E. Scar formation ```

Answer 553

E. Scar formation [Osteogenesis imperfecta have decreased production of type 1 collagen, which is important in late wound repair (scar formation)]

Question 554

A positive acidified serum test in the setting of anemia and “dark urine in the morning” indicates PNH. This is characterized by which of the following? ``` A. Abnormal cell morphology B. Decreased G6PD activity C. Defect in a cell membrane anchor protein D. Destabilization of cytoskeleton E. Underproduction of globin proteins ```

Answer 554

C. Defect in a cell membrane anchor protein [impaired synthesis of GPI ancho fro decay-accelerating factor (CD55) and membrane inhibitor of reactive lysis (CD59) that protects RBC from complement]

Question 555

What are the fibrous proteins that form the 2-dimensional network on the inner surface of the nuclear membrane?

Answer 555

Lamins

Question 556

Which of the following is a virus that forms plaques on human laryngeal cells but rapidly loses its ability to form plaques when dried or exposed to acidic pH? ``` A. Coronavirus B. Coxsackievirus C. Epstein Barr virus D. Norovirus E. Rotavirus ```

Answer 556

A. Coronavirus

Question 557

Male with gradually progressive weakness, anorexia, and weight loss over period of 6 months, BP is 75/41, skin is hyperpigmented, and morning cortisol is low. Which of the following? ``` A. Adrenocortical carcinoma B. Amyloidosis C. Autoimmune adrenalitis D. Basophilic pituitary adenoma E. Metastasis to adrenal gland ```

Answer 557

C. Autoimmune adrenalitis [aka Addisons disease]

Question 558

Total occlusion of blood flow by a tourniquet followed by removal of occlusion results in 50% increase in flow, then a return to baseline control values. What substance is responsible?

Answer 558

Adenosine

Question 559

HOX genes play a role in embryogenesis through regulation of ______

Answer 559

Transcription

Question 560

What serum marker is most likely elevated with a biliary tract obstruction, specifically a common bile duct obstruction?

Answer 560

Alkaline phosphatase

Question 561

What ion channel is blocked by tetradotoxin from a puffer fish?

Answer 561

Sodium channels

Question 562

Infectious mononucleosis results in atypical lymphocytes seen on peripheral smear. What type of cells are these?

Answer 562

Reactive CD8+ T lymphocytes [Not infected B cells!!!]

Question 563

Young pt with lethargy and mild hepatomegaly, hypoglycemia, lactic acidemia, ketonemia, and metabolic acidosis. IV administration of glycerol or fructose does not increase serum glucose. IV administration of galactose DOES increase serum glucose. What liver metabolic pathway is the cause of these findings?

Answer 563

Gluconeogenesis

Question 564

A 3 week period of bed rest results in what physiologic change? ``` A. Decreased blood volume B. Decreased plasma sodium C. Increased plasma aldosterone D. Increased plasma volume E. Increased sympathetic tone ```

Answer 564

A. Decreased blood volume

Question 565

A 55 y/o male with an acute MI, hypotension, elevated JVP, and pleural effusion results in what changes in PCWP, CO, and SVR?

Answer 565

PCWP increases CO decreases SVR increases

Question 566

In neonatal respiratory distress syndrome, supplemental O2 can result in complications of retinopathy of prematurity, intraventricular hemorrhage, and _____ _____

Answer 566

Bronchopulmonary dysplasia [lungs firm and poorly aerated, prominent interstitial fibrosis surrounding irregular, dilated airspaces with bronchiolar metaplasia]

Question 567

What veins allow for tumor cells in the breast to obtain access to vertebral bodies for metastasis?

Answer 567

Intercostal vv.

Question 568

What causes the increase in total serum T3/T4 in pregnancy?

Answer 568

Increased hepatic production of T4-binding globulin

Question 569

Sudden onset dysarthria, dysphagia, and dizziness; exam shows decreased pain sensation on right side of face and complete loss of pain sensation on left side of body. What blood vessel is affected?

Answer 569

Anterior inferior cerebellar artery (on right side)

Question 570

Which of the following explains hypokalemia of alcohol withdrawal? ``` A. Catecholamine-mediated intracellular shift of K+ B. Decreased dietary intake of K+ C. Decreased renin release D. Decreased urine flow rate E. Increased muscle breakdown ```

Answer 570

A. Catecholamine-mediated intracellular shift of K+

Question 571

Deficiency of vitamin ____ appears similar to Vit B12 deficiency with neurologic presentation including decreased position/vibration sense, but it does not show megaloblastic anemia or hypersegmented neutrophils

Answer 571

Vitamin E

Question 572

What stage of the cell cycle are cyclins made?

Answer 572

G2

Question 573

Loss of pain and temp on the right side of the face and the left side of the body, paralysis of vocal cord on the right, and absence of gag reflex on the right. Which of the folowing is damaged? ``` A. Left ventromedial medulla B. Right ventromedial medulla C. Left dorsolateral medulla D. Right dorsolateral medulla E. Left ventrolateral pons F. Right ventrolateral pons G. Left ventromedial midbrain E. Right ventromedial midbrain ```

Answer 573

D. Right dorsolateral medulla

Question 574

Breakdown of dipeptides and tripeptides into free amino acids takes place primarily in what area in the GI tract?

Answer 574

Intestinal mucosa

Question 575

Which of the following is the most likely cause of drug-induced bone marrow suppression in HAART? ``` A. Azithromycin B. Lamivudine C. Nelfinavir D. Pentamidine E. Zidovudine ```

Answer 575

E. Zidovudine

Question 576

17 y/o F who has never had a period, BMI is 15, breast development stage 5, pubic/axillary hair stage 1, pelvic exam shows blind vaginal pouch. Which of the following is most likely? ``` A. Decreased serum estrogen B. Decreased serum LH C. Hyperplastic adrenal cortices D. Increased serum testosterone E. Streak ovaries F. Uterus ```

Answer 576

D. Increased serum testosterone

Question 577

What artery maintains anastomotic supply to testicle if the testicular artery is ligated?

Answer 577

Artery of the ductus deferens

Question 578

19 y/o M reports 1 week of weakness in neck and extremities; position sense is also impaired. Bowel and bladder function normal. Which is most likely? ``` A. ALS B. Parkinson C. Poliomyelitis D. Polyneuropathy E. Syringomyelia ```

Answer 578

D. Polyneuropathy

Question 579

Which of the following are connected by desmosomes: ``` A. Basal keratinocyte:lamina lucida B. Basal keratinocyte:suprabasal keratinocyte C. Granular keratinocyte:stratum corneum D. Lamina lucida:lamina densa E. Melanocyte:basal keratinocyte ```

Answer 579

B. Basal keratinocyte:suprabasal keratinocyte

Question 580

A strain of bacteria sensitive to ampicillin is cultured with another type of bacteria that is resistant to ampicillin. After co-culturing, the initial bacteria is now resistant to ampicillin. What mode of bacterial genetic transfer occurred?

Answer 580

Conjugation

Question 581

2 initial substrates for heme synthesis

Answer 581

Glycine | Succinyl coA

Question 582

Inability to recognize objects unless touching them or hearing them (alexia) represents a lesion supplied by what artery?

Answer 582

Posterior cerebral a. (Affecting occipital lobe)

Question 583

Inability of alpha intercalated cells to secrete H+, so no new HCO3 is generated, resulting in metabolic acidosis Urine pH > 5.5 Serum K+ decreased

Answer 583

RTA type 1 (distal renal tubule) [causes: amphotericin B toxicity, analgesic nephropathy, congenital anomalies/obstruction, autoimmune disease like SLE]

Question 584

Defect in PCT HCO3 reabsorption resulting in metabolic acidosis Urine pH < 5.5 Serum K+ decreased

Answer 584

RTA type 2 (proximal renal tubule) [causes: fanconi syndrome, multiple myeloma, carbonic anhydrase inhibitors]

Question 585

Hypoaldosteronism or aldosterone resistance leading to hypokalemia, which results in decreased NH3 synthesis in PCT and subsequent decrease in NH4 secretion Urine pH <5.5 (or variable) Serum K+ increased

Answer 585

Type 4 RTA (hyperkalemic RTA) [causes: decreased aldosterone production due to diabetic hyporeninism, ACEIs, ARBs, NSAIDs, heparin, cyclosporin, adrenal insufficiency; or aldosterone resistance due to K+ sparing diuretics, nephropathy d/t obstruction, or TMPSMX]

Question 586

Herniation of abdominal contents into the left pleural cavity in a full term infant indicates maldevelopment of what structure

Answer 586

Left pleuroperitoneal membrane

Question 587

A genetic abnormality in what enzyme results in slow recovery from paralysis induced by a short-acting neuromuscular blocking agent?

Answer 587

Pseudocholinesterase

Question 588

Female infant with fever of 102, vomiting, diarrhea, and dehydration, exam of a stool suspension by negative stain electron microscopy shows viral particles with a wheel-like shape. What is the morphology of the involved virus?

Answer 588

Naked dsRNA, segmented icosahedral

Question 589

35 y/o man with severe midline back pain due to compression fractures at T10 and L1, 8 lb weight gain, and imaging shows a pituitary macroadenoma. The most likely cause of his symptoms is a tumor producing what hormone?

Answer 589

ACTH

Question 590

A prosthetic endograft is inserted in the femoral artery, threaded up the aorta, then expanded when in place. It extends from just below the renal arteries to the bifurcation of the aorta. Which of the following organs is most likely to lose its primary blood supply and now must rely on collateral circulation: ``` A. Adrenal gland B. Descending colon C. Pancreas D. Spleen E. Stomach ```

Answer 590

B. Descending colon

Question 591

A patient on alendronate, calcium carbonate, ezetimibe, HCTZ, and simvastatin is placed on ciprofloxacin for a UTI. Which of her medications most likely interfered with the efficacy of the antibiotic?

Answer 591

Calcium carbonate

Question 592

After a chemical attack, a patient is given atropine. What other drug is most appropriate to add?

Answer 592

Pralidoxime

Question 593

A 17 y/o male is short and thin. His FSH is 5 mlU/mL (N=4-25) and his testosterone is 8 nmol/L (N=10-35). Which of the following findings is most likely? A. Enlarged testes B. Excess body hair C. Gynecomastia D. Low pitched voice

Answer 593

C. Gynecomastia

Question 594

If all secondary causes of pericarditis are ruled out, which of the following is the most likely cause of a primary pericarditis? ``` A. Bacterium B. Fungus C. Parasite D. Tumor E. Virus ```

Answer 594

E. Virus

Question 595

5 y/o female with chronic cough worse at night and productive of thick green sputum. History of intermittent cramps in RLQ and frequent respiratory tract infections. Her 8 y/o bro is healthy. PE shows clubbing of the fingers and hyperresonance to percussion. Diffuse inspiratory crackles and pulmonary wheezing on expiration. CXR shows hyperinflation especially prominent in the right upper lobe. Which of the following represents the likelihood of her brother being a carrier? ``` A. 1/1 B. 1/2 C. 1/3 D. 1/4 E. 2/3 ```

Answer 595

E. 2/3

Question 596

If mom is taking valproic acid, the fetus would be at greatest risk for teratogenic effects at which stage of pregnancy? ``` A. 0-2 weeks B. 3-8 weeks C. 9-12 weeks D. 12-18 weeks E. 18-24 weeks ```

Answer 596

B. 3-8 weeks

Question 597

Following an operation, a 68 y/o patient has a lung region that is underventilated but well perfused. This would lead to an increase in which of the following: ``` A. Alveolar dead space B. Anatomic dead space C. Physiologic dead space D. Physiologic shunt E. PO2 ```

Answer 597

D. Physiologic shunt

Question 598

A pt who recently returned from Africa is started on oral chloroquine therapy for malaria caused by plasmodium vivax. His initial response is good, but he develops recurrent parasitemia 2 months later. Which of the following explains the recurrence? A. Chloroquine is ineffective on P.vivax B. Chloroquine is ineffective on the exoerythrocytic malarial tissue stages C. Chloroquine is only effective when combined with metronidazole D. The patient has a second previously occult malaria infection

Answer 598

B. Chloroquine is ineffective on the exoerythrocytic malarial tissue stages

Question 599

As an incidental finding, only 3 parathyroid glands are found on the posterior side of the thyroid gland, but one is missing from its usual superior location on the right. What embryological event led to this finding?

Answer 599

Abnormal migration of endoderm from the 4th pharyngeal pouch

Question 600

Following a 4 week course of radiation therapy for breast cancer, a patient develops bilateral patches of atelectasis in the upper lung fields. The atelectasis in this patient most likely developed because of which of the following: ``` A. Compression B. Consolidation C. Contraction D. Obstruction E. Resorption ```

Answer 600

C. Contraction

Question 601

Total cholesterol of 200, HDL of 50, and triglycerides of 550. Which lipid-lowering agent should be added?

Answer 601

Fenofibrate

Question 602

The presence of a lysine (k487) for a glutamate (E487) codes for the oriental variant of aldehyde dehydrogenase. What effect does this have on the enzyme?

Answer 602

Decreased catalytic efficiency of K487

Question 603

X linked recessive disease resulting in defective __________ leads to deafness, hematuria, and progressive renal failure

Answer 603

Type IV collagen

Question 604

Patient with group A strep pyogenes has a widespread, red, sandpaper-like rash over the extremities. What strep component is the cause of these skin findings?

Answer 604

Erythrogenic toxin

Question 605

A study designed to test effectiveness of a treatment divides 100 women into 2 groups. 48 receive the new drug, 52 receive standard therapy. The primary purpose of assigning patients to different groups is to create which of the following: A. Double blind study B. Single blind study C. 2 groups with similar sample size D. 2 groups with similar underlying characteristics

Answer 605

D. 2 groups with similar underlying characteristics

Question 606

Secretion of hormones from which cells causes contraction of the gallbladder?

Answer 606

Enteroendocrine cells of the small intestine

Question 607

6 month history of increased forearm bruising, extensive wrinkling, scaly erythematous patches on the face, and irregularly shaped brown macules on the face and forearms. Ecchymoses are of various stages of healing and more numerous on the right side. Labs are all normal. There is no gum bleeding noted. Which of the following is the most likely cause of ecchymoses? A. Exocytosis of lymphocytes B. Extensive solar elastosis C. Impaired platelet function D. UV destruction of langerhans cells

Answer 607

B. Extensive solar elastosis

Question 608

A man with normal renal function receives a heart transplant. One year later he has a BP of 170/110 and a serum creatinine of 2.1. What immunosuppressive drug most likely caused these findings?

Answer 608

Cyclosporine

Question 609

A pt with a PE is put on IV heparin and 24 hrs later warfarin is added. On day 2, PTT is prolonged and PT is WNL. Which of the following best explains the normal PT and INR? A. Heparin-warfarin interaction B. Long half life of factor II (prothrombin) C. Too low of a dose of warfarin D. Undetected liver disease

Answer 609

B. Long half life of factor II

Question 610

1 day of fever, chills, confusion, and memory loss after returning from the Gulf coast where pt walked barefoot on the beach. Hx of severe cirrhosis and portal HTN. Temp 102, BP 90/40, PE shows cellulitis of right LE with early blister formation. One day later cultures grow gram-negative lactose fermenting organism. What is the most likely causal organism?

Answer 610

Vibrio vulnificus

Question 611

Which of the following should pts with Raynauds avoid? ``` A. Acetaminophen B. Dextromethorphan C. Diphenhydramine D. Ibuprofen E. Phenylephrine ```

Answer 611

E. Phenylephrine

Question 612

During a study a pt with normal calcium, PO4, and PTH is given infusion of 2 g calcium chloride over 2 hours. His calcium concentration is now 11.5 mg/dL. Compared with pre-infusion level, which of the following substances is most likely increased? ``` A. 7-dehydrocholesterol B. 1,25-dihydroxycholecalciferol C. 24,25-dihydroxycholecalciferol D. Previtamin D3 E. Vitamin D3 ```

Answer 612

C. 24,25-dihydroxycholecalciferol

Question 613

10 y/o M with 4 day hx of nosebleeds and easy bruising. 3 weeks ago he had a URI. PE shows ecchymoses over upper and lower extremities. Labs show normal Hb and leukocyte count with decreased platelet count. Bone marrow smear shows increased megakaryocytes. Which of the following is most likely? A. Abs against gp IIb/IIIa complex B. Decreased binding of GpIa/IIa to collagen C. Decreased concentration of GpIa/IIa D. Decreased concentration of gp IIb/IIIa E. Decreased synthesis of thromboxane A2

Answer 613

A. Abs against gp IIb/IIIa complex

Question 614

Pt has severe hemorrhage and shock, xray shows fracture of left 9th and 10th ribs. What organ is injured?

Answer 614

Spleen

Question 615

Pt has 47, XXY karyotype and molecular genetic studies show one of the X chromosomes was inherited from the pts father. An error of chromosome segregation most likely occurred during anaphase at which stage of spermatogenesis in the pts father?

Answer 615

Primary spermatocyte

Question 616

39 y/o male with 1 week hx of red spots on shins, joint pain, and fatigue. PE shows purpura over lower extremities. Liver edge is 4 cm below R costal margin. Labs show elevated LFTs, positive Hep C Abs, cyroglobulins, decreased C4, proteinuria 4+, and numerous RBCs in urine. What type of HSR?

Answer 616

Type III

Question 617

Pt is fearful of being stuck with needle while awake. The most appropriate anesthesia administered by mask to anesthetize the pt quickly would have which of the following characteristics? ``` A. High blood solubility B. High CSF solubility C. High lipid solubility D. Low blood solublity E. Low lipid solubility ```

Answer 617

D. Low blood solubility

Question 618

Which of the following is the genetic mechanism of antigenic shift? ``` A. Amplification B. Frameshift C. Point mutation D. Reassortment E. Recombination ```

Answer 618

D. Reassortment