step 1 Flashcards
1
Q
What substance depends on Ca2+ and is responsible for cell adhesion?
A
Cadherins (desmogleins, desmocollins, E-cadherin).
- Loss = metastasis
- binding forms adheren junction and desmosomes
2
Q
What type of virus is the Molluscum contagiosum? What would biopsy show?
A
- Poxvirus
- biopsy= eosinophilia cytoplasmic inclusions (mulluscum bodies)
3
Q
Knee dislocation posterior and anterior, put what structure at especially high risk of damage?
A
Popliteal artery (continuation of femoral artery) damage = diminished posterior tibialis and dorsalis pedis pulses
4
Q
What happens when a ligand binds to tyrosine kinase? What ligand bind to tyrosine kinase?
A
- Causes dimerization, each subunit phosphorylates the other
- Insulin, epidural growth factor, platelet derived growth factor, and vascular endothelial growth factor
5
Q
What happens to GFR after a unilateral nephrectomy?
A
- Immediately after surgery : 50%
- Six weeks after surgery: 80%
6
Q
Phosphodiestrase 5 inhibitor (sildenadil) treat erectile dysfunction how?
A
Increase cGMP in vascular smooth muscle of corpora cavernous= smooth muscle relaxation = engorgement
7
Q
Carniopharyngiomas cause what?
A
Bitemporal hemianopia, suprasellar optic chiasm
8
Q
Acute stress disorder vs PTSD
A
- Acute stress disorder lasts > or equal to 3 days and < 1 month
- PTSD symptoms greater than a month
9
Q
Schizophreniform disorder versus schizoaffective disorder
A
- Schizophreniform disorder: > 1 month and < 6 months
- schizoaffective disorder: concurrent mood symptoms, at least 2 weeks delusions or hallucinations with absence mood symptoms
10
Q
False positive eqn
A
1- specificity
11
Q
Relative risk eqn
A
Risk of people with mutation getting disease/ risk people without mutation getting disease
12
Q
What is the most common cause of viral encephalitis ?
A
Herpes simplex virus, effects temporal lobe
- causes olfactory hallucinations and bizarre behavior
13
Q
Patient presents with intermittent reddish brown urine that darkens when in light. No dysuria and no increase in frequency. She also has abdominal pain and aggressive outbursts. Diagnosis?
A
- Acute intermittent porphyria
- defect PGB deaminase = increase PGB and ALA
- autosomal dominate
- no photosensitivity
14
Q
What is the most common porphyria?
A
- uroporphyrinogen decarboxylase deficiency
- Associated with exposure to aromatic hydrocarbons, estrogen, hepatitis C
- Causes cutaneous photosensitivity
15
Q
Rb is a what? What is it a/w?
A
- Tumor suppressor gene (need 2 hit)
- a/w retinoblastoma and osteosarcoma
- Inhibit E2F, blocks G to S phase
16
Q
Patient has low CD3, but normal CD20. Exam shows dysmorphic face and cleft palate. Patient also has recurrent white patches on inside of cheeks. What is the diagnosis?
A
DiGeorge Syndrome
- 22q11 deletion
- failed 3rd and 4th pouche development
- hypocalcemia
17
Q
Patient is in diabetic ketoacidosis, what is the potassium, sodium and glucose level?
A
High potassium, low-sodium, high glucose
18
Q
Male with testicular atrophy.
- Low testosterone, high LH, and high estrogen
- high FSH
- diagnosis?
A
Klinefelter syndrome, 47 XXY
19
Q
Male hypogonadism. Decreased FSH, LH, testosterone. Diagnosis?
A
- Kallmann
- defect migration GnRH releasing neurons
20
Q
Inhibit B function
A
Inhibit FSH
21
Q
A patient has pheochromocytoma, what do you give before surgery to prevent hypertensive crisis?
A
Phenoxybenzamine
22
Q
Cisplatin SAE
A
Ototoxicity, damage stereocilia on hair cells
23
Q
Etoposide SAE
A
Alopecia, GI irritation and myelosuppression
24
Q
Doxorubicin SAE
A
Alopecia, myocardial damage and myelosuppresion
25
Methotrexate SAE
* myelosuppression and fatty change liver
* pulmonary fibrosis
26
Amiodarone SAE
* interstitial **pneumonitis**, slow progressive dyspnea, and nonproductive cough
* arrhythmias, hepatic injury, thyroid abnormalities, and blue-gray skin discoloration
27
How misoprostol works?
* **PGE1** analog binds prostaglandin receptor in **parietal cell.**
* increase mucus and decrease acid secretion
28
How cimetidine and ranitidine work?
block H2 receptor in parietal cells in stomach
29
Aspirin exacerbated Airway disease
Asthma + aspirin = nasal congestion and bronchospasm
* dysregulation arachidonic acid down 5-lipoxygenase pathway = increase leukotriene
30
Nitrates what do they do?
* Systemic vasodilation (mainly **venodilation**)
* **decrease left ventricular volume** and wall stress
* **decrease O2** demand
* **reflex** **tachycardia**
31
Cystic fibrosis pathophysiology
**CFTR** encodes **ATP-gated Cl** channel
* **_secretes_ Cl** in **_lungs and GI tract_** **and slow down Na reabsorption**, **_reabsorbs_ Cl** in **_sweat glands_** and aids in **Na secretion**
* misfolded protein= **retain in RER**
* **Chr 7**
* Increase immunoreactive **trypsinogen** (newborn screen)
Complications
* **Recurrent pulmonary infections** (S. Aureus, infant) (P. aeruginosa, adolescent), CXR **reticulonodular pattern**
* pancreatic insufficency, **steatorrhea** (fat soluble deficiency)
* **liver disease**
* **infertility** men (no vas), subfertility women
* nasal polys, **nail clubbing**
****treatment
* albuterol, **DNase**, **hypertonic saline** facilitate mucus clearance, **azithromycin** (anti-inflammatory), **ibuprofen** (slow disease progress)
* **lumacaftor** (correct misfolded protein), **ivacaftor** (opens Cl channels) = Phe508 deletion
32
Five-year-old boy has recurrent **muscle spasms** in his hand. On exam he has prominent skeletal abnormalities, including **short stature, short 4th and 5th fingers,** and a round face. Serum **calcium** level is **low**, and **serum phosphorus and parathyroid hormone levels are elevated.** Creatinine is normal. What is diagnosis?
Pseudohypoparathyroidism (Albright hereditary osteodystrophy)
* **End organ resistance to PTH**, due **defect** PTH **receptor** (defective Gs)
* **AD**, defect inherited mother due **imprinting**
33
Pathogenesis of bronchial asthma
Eosinophil + mast cells = leukotrienes C4,D4, and E4 = broncospasms + increase bronchial mucus
* Montelukast antagonize D4
34
ELISA steps
1. Add antigen attached to well
2. Add patient serum, then wash
3. add anti-human immunoglobulin antibodies, then wash
4. substrate then cause color change added
35
Mechanism of acquired antibiotic resistance
Bacterial antibiotic efflux pumps are powered by moving protons across concentration gradient out of cells coupled with expelling antibiotic out of bacteria
* require energy (created by proton gradient)
* adding protons eliminates gradient, so inhibit efflux pumps
36
Patient has had circumference at 90th percentile, midface hypoplasia, and femoral and humeral shortening. Patient has a space between the third and fourth digits. What is the most likely cause of the patients presentation?
Achondroplasia
* **FGFR3** , **gain of function point mutation**
* restricted **chondrocyte** proliferation at growth plate
* 90% de novo mutations, 10% inherited
* increase risk **spinal stenosis**
37
Infant has recurrent infections and is diagnosed with an intracellular messaging abnormality. The abnormal gene codes for a tyrosine kinase. What is the disorder?
X-linked (Bruton) agammaglobulinemia
* BTK defect = no B cell maturation
* XR
* decrease maternal IgG, at 6 months
38
Ribosomes bind to mRNA in cytosol and translation initiates. Which proteins go to the RER?
Mostly hydrophobic Proteins with **N terminal peptide signal sequences** are recognized by signal recognition particle (**SRPs**), brought to RER
39
Newborn has increased alpha keto acids in blood and urine. Patient has problems feeding and occasionally vomits. What is the diagnosis? What branched amino acids will accumulate?
**Isoleucine, leucin, valine** (I Love Vermont maple syrup from maple trees (with b1ranches)
* need B1 = **thiamine**
* maple syrup urine diseas (AR)
40
Two parents from Thailand coming with the history of blood disorders. They are told that prognosis of future children would be fatal. What do these parents have? What would show on blood smear?
* Alpha thalassemia minor (2 missing genes)
* Mild microcytic anemia, hypochromic
* Future children at risk for hemoglobin Barts (4 gamma chains= hydros fetalis (anasarca, ascites, effusion))
41
Normal testosterone and LH concentration and serum, but low testosterone in seminferous tubules and epididymis. What types of cells have dysfunction causing this?
**sertoli cells** produce **androgen binding protein**, which **maintains testosterone level in seminiferous tubule** by making it less lipophilic to **reduce diffusion out**
* FSH stimulate Sertoli cells to produce ABP and secrete into seminiferous tubule lumen
42
Glucagon acts through which proteins in hepatocytes?
GPCR, **Gs protein = cAMP**
43
Sweating is controlled by what?
44
Red safranin O stains what red and what blue?
Red= cartilage, mast cells, and mucin
blue= bine
45
A patient with an epinephrine secreting tumor will have what elevated in their urine and plasma?
* Epinephrine converted to **metanephrine** and then **vanillymandelic acid** (via monoamine oxidase)
* cause **episodic HTN**
* derived from **chromaffin cells** (from **neural crest**)
46
A patient has a pulmonary embolism, what happens to their blood gases and pH?
* V/Q mismatch = hypoxemia = hyperventilation
* **Respiratory alkalosis** (increase pH, decreased PaCO2)
47
Patient has right ventricular hypertrophy and SOB, what caused this?
Pulmonary endothelial dysfunction = pulmonary arterial hypertension
48
Patient has hypoglycemia after prolonged fasting with inappropriately low Ketone bodies suggests what diagnosis?
**Impaired beta oxidation**, medium chain **acyl-CoA dehydrogenase deficiency**
49
BRACA1, cyclin D, c-myc, p53, Ras, and Rb. Name function and associated cancer
* **BRACA1** : tumor gene, **DNA** **repair** protein ; breast, ovarian, pancreatic cancer
* **cyclin D:** **promoter G1 to S** transition cell cycle
* **c-myc**: oncogene; **transcription factor**; **Burkett lymphoma**
* **p53**: tumor suppressor, **blocks G1 to S** phase; **Li-Fraumeni** syndrome (breast, leukemia, adrenal gland, sarcoma), only need one hit because first hit germline
* **Ras**: oncogene, **GTPase (signal tranducing**); **colon, lung and pancreatic** cancer
* **Rb**: tumor suppressor (hypophosphorylated =active), **blocks G1 to S** phase; **retinoblastoma**, osteosarcoma
50
A patient comes in with chronic diarrhea, facial flushing, and tachycardia. He also has a lower quadrant tumor. What drug would help manage this patient’s symptoms?
Octreotide, somatostatin analog
51
How does cells undergoing apoptosis get the proteins necessary to complete apoptosis, if the eukaryotic intrinsic factor (iIFs), that binds ribosome to 5’ cap for translation, is degraded?
Internal ribosome entry, allows translation to begin in middle mRNA instead of at AUG
52
How does Thiazolidinediones (pioglitazone, rosiglitazone) work?
* Treat diabetes (decrease insulin resistance)
* Up regulate GLUT4
* up regulate adiponectin
53
What medications inhibit CYP450? What medications induce CYP450?
(warfarin metabolized by)
* Inhibitors (increase effect of drugs metabolized by)0000000086024968
* Acetaminophen, NSAIDs
* antibiotics/antifungals (-azoles)
* amiodarone
* cimetidine
* vit E, cranberry juice
* omeprazole
* thyroif hormone
* SSRI (fluoxetine)
Inducer CYP450 (decrease effect of drugs metabolized by)
* Carbamazepine, phenytoin
* ginseng, St. John’s wort
* oral contraceptive
* phenobarbital
* rifampin
54
Patient has hepatic encephalopathy, what will improve confusion symptoms?
Lactulose acidified content GI, converting NH3 to NH4
55
Patient is having asthma attack and is treated. What protein does the drug bind to to stimulate reaction?
Drug was a beta 2 agonist= Gs, cAMP
56
76-year-old complains of bone pain and weakness. He prepares his own meals, which are mainly prepackage processed foods. He spends little time outdoors and prefers to watch movies. This patient most likely has impaired mineralization of which component of bone? What would an x-ray show? Labs?
Osteomalacia
* Impaired mineralization of osteoid
* Xray show osteopenia and loose zones with pseudofractures
* labs: Low vitamin D, low serum calcium, high PTH, low serum PO4, high Alkaline phosphatase(hyperactive osteoblasts)
57
Dilation of aortic arch can result in damage to what?
* Damage **left recurrent laryngeal nerve** branch off of vagus nerve, because it loops below aortic arch. It innervates intrinsic muscles of larynx, responsible of sound production, so get **hoarseness**
* left recurrent laryngeal nerve (posterior cricoartenoid, lateral cricoarytenoid, oblique arytenoid, transverse arytenoid, thyroarytenoid)
* external laryngeal n = cricothyroid
* internal laryngeal = supraglottic sensation
58
You shit comes in like two days of progressive fatigue and dyspnea. The patient is on medication for hypertension (amlodipine) and recently began treatment for uncomplicated prostatitis with trimethoprim/sulfamethoxazole. Every several years ago. Physical exam showed scleral icterus and mild splenomegaly. Hemoglobin 7.2 g/dL and reticuloctyes 8%
what does this patient have?
**Glucose 6 phosphate dehydrogenase deficiency**, caused by oxidant stress from trimethoprim/sulfamethoxazole
* Hemolysis
* methemoglobin formation
59
Unmyelinated nerve fibers are a component of what?
autonomic postganglionic nerve
60
MHC I (CD8) vs MHC II (CD4)
**MHC** **I**: presents **endogenously** synthesized **antigens** in **RER**, a/w beta2-microglobulin, expressed on **all nucleated cells**, APCs, not RBCs
**MHC II**: presents **exogenously** synthesized **antigens** in **acidified endosome,** a/w **invariant chain**, expressed on **APCs**
61
Reactive arthritis is a/w what HLA allele? What is it caused by?
* **HLA B27**
* **Deposition of immune complexes** involving bacterial antigens, however joint aspirate is **sterile**
* happen **post infection**
62
43-year-old patient comes in for with diarrhea. For the past two weeks, she has had a pruritic rash. For the last six months she has had watery diarrhea with abdominal bloating and weight loss. What is her diagnosis?
**_Celiac disease_**
* caused by **gliadins**
* small bowel **villous atrophy**
* a/w **dermatitis herpetiformis** on elbows and knees
* **cross reactivity anti-gliadin IgA antibodies and transglutaminase** at dermal basement membrane
63
Hypertrophy is a/w what in cardiac cells?
Increased myosin mRNA synthesis
64
Callus is thickening of what layer of skin?
Stratum cornermen, most superficial layer
65
Polycystic ovarian syndrome is caused by an increase in what hormone?
Increased testosterone
66
18month old boy with the developmental delay present with a habit of aggressively biting his fingers, tongue, and lips. Patient has high urinary uric acid. What enzyme is most likely deficient in this patient?
Lesch-Nyhan syndrome (XR)
* deficiency **hypoxanthine-guaniune phosphoribosyltransferase**
* Cause **nephrolithiasis** and **gout**
* treatment: **allopurinol**
67
Doxycycline MOA
tetracyclines bind to 30S ribosomal subunit and block aminoacyl-tRNA from entering ribosomal acceptor site
68
Acanthosis nigricans are a/w what?
Diabetes, obesity, Cushing syndrome and **gastric malignancy**
69
Tay-Sachs disease vs Niemann-Pick disease vs Gaucher disease vs Fabry disease
* **_Tay-Sachs disease_**: progressive neurogeneration, **cherry red spot**, **no hepatosplenomegaly**
* Deficient **hexosaminidase** A, accumulate **GM2 ganglioside**
* **AR**
**_Niemann-Pick disease_**: progressive neurodegeneration, **cherry red spot**, **hepatosplenomegaly**
* Deficient **Sphingomyelinase**, accumulate **sphingomyelin**
* **AR**
**_Gaucher disease_**: hepatosplenomegaly, osteoporosis, pancytopenia, Gaucher cells
* Defect **glucocerebrosidase**, accumulate **glucocerebroside**
* **AR**
**_Fabry disease_**: **episodic peripheral neuropathy**, angiokeratomas, hypohidrosis
* progressive **renal failure**, cardiovascular disease
* Deficient **alpha-galactosidase A**, accumulate **ceramide trihexoside**
* **XR**
70
Epinephrine messenger system?
* Alpha 1 receptor
* vasoconstriction
* Gq activated by phospholipase C =\> inositol triphosphaste (IP3) + diacylglycerol (DAG) =\> IP3 liberate Ca2+ and DAG activate PKC =\> smooth muscle contraction
71
Infliximab vs etanercerpt
Infliximab: anti- TNF-alpha antibody
entanercept: recombinant TNF receptor fusion protein
72
Imatinib
inhibits Bcr-Abl tyrosine kinase, a/w chronic myeloid leukemia
73
Tacrolimus
**suppresses T lymphocyte** activation by binding **FKBP-12**
* used in **transplant patients** and severe **atopic dermatitis**
74
How does prednisone work?
suppresses **polymorphonuclear leukocyte migration** and reverse increases **capillary** **permeability**
75
How aspirin work?
irreversibly **inhibit COX-1** in platelets, **preventing** synthesis **thromboxane** **A2**, a stimulator of platelet aggregation and vasoconstriction = cardioprotective
76
Newborn is going to have a catheter put through umbilical vein and into inferior Vena Cava. What must the catheter pass through to reach the IVC?
Ductus venosus to liver to IVC
77
17 year old girl f/u after miscarriage. She has a didelphys uterus, hypoplastic first digits. What mutation does she likely have?
Homeobox genes
* HOXA13
* hand-foot-genital syndrome
78
Patient has increased urine output and decreased urine osmolality. Patient does not appropriately respond to water deprivation. They have a aquaporin 2 gene mutation. What do they have? What will be elevated?
**Nephrogenic diabetes insipidus**,
* **Increased serum vasopressin** due to vasopressin **resistance in collecting ducts**
* **Sodium normal** (high in central Diabetes insipidus)
79
Decrease what to increase contraction velocity?
decrease afterload
80
Patient presents with flank pain, gross hematuria, and oliguria. The patient has a metabolic acidosis, what substance is responsible for these symptoms?
Ethylene glycol poisoning
* Microscopy would show envelop or dumbbell shaped calcium oxalate crystals
81
Which parts of sacromere change size and which do not?
The I band that contains the Z line: lengthens with relaxation and shortens with contraction
A band stays the same size
82
Murmur that is holosystolic, best heard left sterna border. Certain maneuvers make louder
VSD
83
32-year-old man comes into the emergency department with sharp chest pain that increases with deep inspiration‘s and decreases when he sits up. We had a mild respiratory illness one week ago. His blood pressure is 120/70 and his pulse is 110. What do you suspect?
Acute pericarditis. Patient should have a friction rub.
84
Predictive values are dependent on what?
**Prevalence** of disease, as prevalence increases the number of true positives increases (PPV)
85
A baby is born premature and has low dipalmitoylphosphatidylcholine, what should you give?
Corticosteroids increase surfactant production by accelerating maturation of type II pneumoncytes
86
Primary hyperparathyroidism. Labs? Imaging? Symptoms?
* **High** serum **calcium**, **low** serum **phosphate**, **high PTH**
* Imaging**: suberiosteal erosions** in digits hand, **granular** salt and pepper **skull**, **osteitis fibrosa cystica**
* high calcium sympyoms:
* **stones -** calcium phosphate stones
* **bones-** Strip calcium from compact bone
* **groans**- constipation
* **psychiatric overtones-** depression
87
A patient presents with hyperinflated lungs and bilateral wheezing. Patient have a normal heart size and prolonged expiration. What drug is most likely to provide immediate relief and how does it work?
* Beta adrenergic agonist
* Increase intracellular cAMP = bronchial smooth muscle relaxation
88
Clopidogrel does what? Treats what?
* **Inhibits ADH induced platelet aggregation.**
* tx: **atherosclerotic** **ischemic** **disease** and **prevent acute stent thrombosis** following percutaneous coronary intervention
89
How treat pulmonary HTN
Bosentan - endothelial (vasoconstrictor) receptor antagonist
90
How does diphenoxylate work? What does it treat?
* Opioids anti-diarrheal
* binds mu opiate receptors in GI and slows motility
91
Serotonin syndrome symptoms? How treat it?
* symptoms: **mental status changes, neuromuscular dysfunction,** and autonomic instability (**rapid** and large **changes** in **blood pressure and heart**).
* treatment: airway maintenance, hydration, temperature maintenance, and for severe cases **cyproheptadine** (histamine antagonist, nonspecific 5-HT1 and 5-HT2 receptor antagonist
92
How does streptomycin work? Isoniazid? Rifampin?
Streptomycin: Interfere with 30S subunit, is an aminoglycoside
isoniazid: inhibit mycolic acid synthesis (neurotoxicity, hepatotoxic)
rifampin: target DNA-dependent RNA polymerase (GI upset, rash, red-orange body fluids, cytopenias)
