UWORLD Flashcards
How do Corynebacterium acquire the ability to cause severe pseudomembranous pharyngitis?
The acquire the Tox gene (exotoxin) via lysogenization by a temperate bacteriophage (phage incorporates into bacterial chromosome)
a. What happens if there are no Sertoli cells during gestation?
b. What if there are no Leydig cells?
a. The Sertoli cells secrete MIF and cause mullerian ducts to involute –> without them the paramesonephric ducts develop into internal female genitalia
b. The Leydig cells secrete testosterone that stimulate formation of mesonephric ducts into internal male genitalia
(Testosterone is converted to DHT which causes formation of male external genitalia)
What is the NPV
The probability that a patient truly does not have a disease if she tests negative for the disease
True negatives/Total negative tests
Inversely proportional to prevalence of disease
Features of Edwards syndrome (Trisomy 18)
Small jaws (micrognathia) Small eyes (microopthalmia) Malformed, low-set ears Rocker-bottom feet (also Trisomy 13) Clenched hands with overlapping fingers (Distinguishing)
What is Heteroplasmy?
Describes the presence of normal and mutated mtDNA –> results in variable expression in mitochondrially inherited disease
- Example is MELAS
- Mitochondria inherited exclusively from maternal
What is route that Neisseria meningitidis causes meningitis?
Spread via respiratory and oral secretions –> pharynx –> blood –> choroid plexus –> meninges
Medications that can cause hyperkalemia
Nonselective beta-adrenergic blockers (interfere with Beta 2 mediated intracellular K uptake) ACE inhibitors (inhibit Ang II formation with subsequent decrease in aldosterone secretion) ARBs (decreasing aldosterone secretion) K+ sparing diuretics (block ENaC or aldosterone receptor) Cardiac glycosides (inhibit Na/K/ATPase pump) NSAIDs (impaired local prostaglandin synthesis reduces renin and aldosterone secretion
Examples of stimulus control treatment for insomnia
Leave bedroom when unable to sleep
Use bed only for sleep and sexual activity
Go to bed only when sleepy
Fixed wake-up time, including weekends
High systolic pressure gradient between left ventricle and aorta
Left ventricular outflow obstruction
Aortic stenosis
a. Which artery supplies anterior and left lateral surfaces of heart?
b. What does right dominant circulation mean?
c. Which artery supplies inferior wall of left ventricle (diaphragmatic surface of heart)?
a. Left Anterior Descending and Left Circumflex Coronary artery
b. Right coronary artery gives rise to PDA (85%)
c. Posterior Descending/Interventricular Artery (PDA)
Which nerve is the first arch associated with?
Abnormalities include malformation of which bones?
Trigeminal nerve
Mandible, maxilla, malleus, incus, temporal bone, incus, palate
Which amyloid is associated with Alzheimer disease? What is it a product of?
AB amyloid
Product synthesized by cleavage of APP
What kind of auto-antibodies are helpful in diagnosis of RA?
Anti-citrullinated peptides
How might a patient receiving multiple blood transfusions develop hypocalcemia and paresthesias?
Whole blood collections contain citrate that can chelate serum calcium and cause hypocalcemia
How does a Prolactinoma cause impotence in males?
Prolactin suppresses GnRH –> decreased LH and decreased testosterone
A. Cushing syndrome with elevated ACTH levels that are suppressed by high dose but not low dose dexamethasone
B. Cushing syndrome with elevated ACTH levels that are NOT suppressed by high or low dose Dexamethasone
a. Pituitary adenoma
b. Ectopic ACTH secreting tumor
Argatroban
Direct Thrombin inhibitor that can be used instead of Heparin/LMWH to treat HIT
a. Nerve roots of Pudendal nerve
b. Provides sensory innervation to:
c. Motor innervation
d. Anatomic landmarks
a. S2-S4
b. Perineum and genitals
c. Urethrae and external anal sphincter
d. Palpate intravaginally for the ischial spine
What kind of receptor does insulin bind and what are the effects?
Insulin binds tyrosine kinase receptor that causes phosphorlyation and leads to a citation of protein phosphatase
- Protein phosphatase dephosphorylates glycoen synthase –> activating it and promoting glycogen synthesis
- Protein phosphatase dephosphorylates fructose 1,6 bisphosphatase –> inactivating it and inhibiting gluconeogenesis
What kind of receptor does insulin bind and what are the effects?
Insulin binds tyrosine kinase receptor that causes phosphorlyation and leads to a citation of protein phosphatase
- Protein phosphatase dephosphorylates glycogen synthase –> activating it and promoting glycogen synthesis
- Protein phosphatase dephosphorylates fructose 1,6 bisphosphatase –> inactivating it and inhibiting gluconeogenesis
How can Strep pneumo obtain genetic material to make it virulent?
Transformation - direct uptake of naked DNA from environment
Through this mechanism, nonvirulent, non-capsule strains of S. pneumo can acquire genes that code the capsule and gain virulence
What is a koilocyte?
Sign of infection with HPV; an immature squamous cell with dense, irregularly staining cytoplasm and perinuclear clearing resulting in a halo
What are Clue cells?
Seen in Pap smear specimens from women with bacterial vaginosis (Gardnerella vaginalis); they are squamous cells covered with bacilli
a. Gram negative oxidase-positive, non-lactose fermenting motile rods that produce pigment
b. What disease does it cause?
a. Pseudomonas
b. Hot tub folliculitis - diffuse pruritic papulopustular rash
a. Anti-apoptotic proteins
b. Pro-apoptotic proteins
c. Released from mitochondria during apoptosis
a. Bcl-2, Bcl-x
b. Bak, Bax, Bim
c. Cytochrome C –> activate caspases
a. What kind of drugs lead to increased lithium levels?
b. What are signs of lithium toxicity?
a. Thiazide diuretics, ACE inhibitors, NSAIDs (lithium is excreted almost exclusively by the kidneys - filtration and resorption in the proximal tubule follows sodium reabsorption)
b. Tremors, agitation, ataxia, delirium, neuromuscular excitability
What drugs are used in asthma provocation test?
Methacholine - muscarinic cholienrgic agonist that causes bronchoconstriction and increased airway secretions
Histamine
Exercise
Cold air inhalation
What is Isoproterenol?
Nonspecific beta-adrenergic agonist that causes bronchodilation
What is Scopolamine?
Antagonist of muscarinic cholinergic receptors used for motion sickness
Prophylaxis of Mycobacterium Avium Complex
Azithromycin
Pharmacologic treatment of Restless Leg Syndrome
Dopamine agonist - Pramiprexole
S/E of Colchicine
Diarrhea
N/V
Abdominal pain
(disrupts microtubule formation in GI mucosal cells)
What is seen on small intestine biopsy of Celiac disease patient?
Flattening of mucosa with loss of villi and chronic inflammatory infiltration of the lamina propria
a. Three main causes of HIV-associated esophagitis
b. Endoscopic findings in each
a. Candida, CMV, Herpes
b. Candida - patches of adherent, gray/white pseudomembranes, Herpes - Small vesicles that evolve into typical punched out ulcers, CMV - linear ulceration
How is Isoniazid metabolized?
By acetylation
How are Azathioprine and 6-mercaptopurine metabolized?
Methylation
Important allosteric activator of gluconeogenesis that acts by increasing the activity of pyruvate carboxylase
Acetyl-CoA
a. What kind of collagen is found in mature scars?
b. What else does this collagen form?
a. Type I collagen
b. Bone, tendon, dermis, ligament, dentin, cornea, blood vessels
a. Echocardiogram of aorta lying to the right and anterior of the pulmonary artery
b. Caused by?
a. Transposition of the great arteries
b. failure of the fetal aorticopulmonary septum to spiral normally during septation of the truncus arteriosus
a. Vitamin B1?
b. Associated with?
a. Thiamine
b. Dry beriberi (symmetrical peripheral neuropathy with sensory/motor impairments of distal extremities), wet beriberi (neuropathy + dilated cardiomyopathy, CHF, peripheral edema), Wernicke-Korsakoff syndrome
Majority of Down’s syndrome cases occur due to:
Maternal meiotic non-disjunction
-Robertsonian translocations account for 3-4% (t14:21 or t21;22)
Why does administration of glucose to alcoholics cause Wernicke encephalopathy (confusion, ataxia, opthalmoplegia)?
Many alcoholics are deficient in thiamine and thiamine is necessary for the TCA cycle because it is a cofactor of alpha keto glutarate dehydrogenase
Why does administration of glucose to alcoholics cause Wernicke encephalopathy (confusion, ataxia, opthalmoplegia)?
Many alcoholics are deficient in thiamine and thiamine is necessary for the TCA cycle because it is a cofactor of alpha keto glutarate dehydrogenase
What are effects of Sotalol on heart?
It blocks beta adrenergic receptors and K channel receptors to cause bradycardia (prolonged PR interval) and prolonged QT interval
What are effects of Sotalol on heart?
It blocks beta adrenergic receptors and K channel receptors to cause bradycardia (prolonged PR interval) and prolonged QT interval
Complicates asthma and results in recurrent pulmonary infiltrates, eosinophilia and proximal bronchiectasis
Asperillus fumigatus - causes Allergic bronchopulmonary aspergillosis
Complicates asthma and results in recurrent pulmonary infiltrates, eosinophilia and proximal bronchiectasis
Asperillus fumigatus - causes Allergic bronchopulmonary aspergillosis (also associated with CF)
Complicates asthma and results in recurrent pulmonary infiltrates, eosinophilia and proximal bronchiectasis
Asperillus fumigatus - causes Allergic bronchopulmonary aspergillosis (also associated with CF)
Lymph from the testes drains to…
Lymph from the scrotum drains to…
- para-aortic nodes
- superficial inguinal nodes
Lymph from the testes drains to…
Lymph from the scrotum drains to…
- para-aortic nodes
- superficial inguinal nodes
In the true pelvis, the left ureter is anterolateral to which structure?
Internal iliac artery
In the true pelvis, the left ureter is anterolateral to which structure?
Internal iliac artery
What allows for binding of myosin to actin?
Upon release from SR, Calcium binds Troponin C on thin filaments. This causes conformational change and tropomyosin shifts so the myosin binding sites on actin are exposed.
What allows for binding of myosin to actin?
Upon release from SR, Calcium binds Troponin C on thin filaments. This causes conformational change and tropomyosin shifts so the myosin binding sites on actin are exposed.
Gram negative, oxidase positive rod that grows well on alkaline media
Vibrio cholerae
Gram negative, oxidase positive rod that grows well on alkaline media
Vibrio cholerae
Why is Ceftriaxone not successful in treating Chlamydia infections?
They have a cell wall but it does not have peptidoglycan.
Why is Ceftriaxone not successful in treating Chlamydia infections?
They have a cell wall but it does not have peptidoglycan.
Little boy losing motor skills, hepatosplenomegaly, cherry red spot on macula, sphingomyelin accumulated in leukocytes
Niemann Pick Disease
Little boy losing motor skills, hepatosplenomegaly, cherry red spot on macula, sphingomyelin accumulated in leukocytes
Niemann Pick Disease
GM2 ganglioside accumulation
Tay Sachs
Deficiency of Hexoaminidase A
GM2 ganglioside accumulation
Tay Sachs
Deficiency of Hexoaminidase A
How does Hartnup disease cause Pellagra?
The intestinal and renal absorption of Tryptophan is defective –> Tryptophan is necessary for Niacin
How does Hartnup disease cause Pellagra?
The intestinal and renal absorption of Tryptophan is defective –> Tryptophan is necessary for Niacin
What kind of blood cell can increase after administration of glucocorticoids?
Neutrophils; as a result of demargination of leukocytes previously attached to vascular wall
What kind of blood cell can increase after administration of glucocorticoids?
Neutrophils; as a result of demargination of leukocytes previously attached to vessel wall
What kind of blood cell can increase after administration of glucocorticoids?
Neutrophils; as a result of demargination of leukocytes previously attached to vessel wall
What is the mechanism of Acarbose?
Alpha-glucosidase inhibitor that decreases the activity of disaccharidases on the intestinal brush border; disaccharidases are membrane bound enzymes
What is the mechanism of Acarbose?
Alpha-glucosidase inhibitor that decreases the activity of disaccharidases on the intestinal brush border; disaccharidases are membrane bound enzymes –> inhibits carbohydrate absorption because carbohydrates are absorbed as monosaccharides
What is the mechanism of Acarbose?
Alpha-glucosidase inhibitor that decreases the activity of disaccharidases on the intestinal brush border; disaccharidases are membrane bound enzymes –> inhibits carbohydrate absorption because carbohydrates are absorbed as monosaccharides
What does positive VDRL of the spinal fluid indicate?
Neurosyphilis
What does positive VDRL of the spinal fluid indicate?
Neurosyphilis (causes damage to dorsal roots and dorsal columns)
Cause of Xanthomas in familial hypercholesterolemia
Decreased LDL receptors
Difference in murmurs caused by infective endocarditis vs. rheumatic fever
Rheumatic fever - can cause mitral stenosis - low pitched mid diastolic murmur (or mitral regurgitation)
Infective endocarditis - causes mitral or tricuspid regurgitation (holosystolic murmur)
Pigmented mucocutaneous macules and multiple GI hamartomas
Peutz-Jeghers syndrome
Autosomal dominant; increased risk of many cancers
Pathogenesis of Pemphigus Vulgaris
Symptoms
IgG antibodies against Desmoglein 1 and 3 that make up desmosomes that adhere epithelial keratinocytes together
Painful flaccid bullae that appear in oropharynx, trunk and extremities
What do cervical spinal cord lesions cause?
Pain, distal sensory dysthesias and muscular weakness (respiratory insufficiency, difficulty swallowing)
-Ocular dysfunction is NOT typically present
How can a woman with Turner syndrome become pregnant?
In vitro fertilization
Most women have ovarian failure
Diagnosis of Diabetes Insipidus
Polyuria
Polydipsia
Urine specific gravity 290mOsm/kg
Polyuria and polydipsia in a Psych patient
Could be Nephrogenic DI from Lithium treatment (impairs vasopressin stimulated collecting duct water reabsorption and renal concentrating ability)