UWorld Test 5/15/2014

Question 1

Lambert Eaton Myasthenic Syndrome ppts with? Differente from MG in what way?

Answer 1

Proximal muscle weakness, autonomic symtpoms, small cell lung cancer, ocular bulbar involvment (ptosis, diplopia). Diff from MG in that LEMS: autonomic symtpoms, iMPROVES with use, hypo/arreflexia

Question 2

What is cretinism?

Answer 2

Congenital hypothyroidism due to maternal hypothyroidism, thyroid agenesis or thyroid dysgenesis (most common cause in US), iodine deficiency, dyshormogenic goiter (congenital defect in thyroid hormon production). PPts with: pot-bellied, hypotonia, jaundice, poor feeding, umbilical hernia, macroglossia (protuberant tongue). poor brain development!!! should catch early to prevent mental retardation

Question 3

Inaled particles smaller than 2 micrometers are cleared by?

Answer 3

They reach alveoli and are cleared by macrophages that release IGF and PDGF, stimulate fibroblasts/connective tissue growth. Pneumoconioses are diseaes that arise from the inhalation of dust particles.

Question 4

Which viruses are known to invade dorsal root sensory ganglia

Answer 4

HSV-1, HSV-2, VZV

Question 5

Foreign double stranded DNA fragments in neuron bodies of 22yo female’s sacral sensory ganglia are a/w?

Answer 5

Recurrent genital rash. HSV-2 tends to hang out sacral. HSV-1 tends to hang out above waist as does VZV

Question 6

What is the tx of digitalis toxicity?

Answer 6

Management of hyperkalemia with insulin, kayexalate or hemodialysis, oral activated charcoal as GI decontaminant, esp in suicide attempts, digoxin specific antibody fragments to bind digoxin in both tissues and vascular spacies.

Question 7

What electrolyte imbalance occurs in acute digitalis toxicity?

Answer 7

Hyperkalemia because you block na/k pump

Question 8

What electrolytic imbalance predisposes you to digitalis toxicity?

Answer 8

Hypokalemia beause this is permissive for digitalis binding.

Question 9

What are clues for psychogenic causes of erectile dysfunction

Answer 9

Suddent onset and presence of morning erections. Men suffering from organic causes typically have intermittent ED that later becomes more persistent

Question 10

Alcohlic patients should receive what before dextrose administration?

Answer 10

Thiamine/Vitamin B1..otherwise it might worsen/ppt wernicke encephalopathy

Question 11

Genetic abnormality in hemochromatisis is what? Affects what?

Answer 11

C282Y or H63D mutaiton on HFE gene, chromosome 6. A/w HLA A3. Affects intestinal absorption of iron => disrupts iron regulation

Question 12

If you see abdominal trauma in vignette think

Answer 12

SPLENIC RUPTURE

Question 13

Intestinal atresia distal to the duodenum arises due to?

Answer 13

Vascular accidents in utero. If SMA is obstructed, “apple peel atresia,” spirals around ileocolic vessel occurs. This manifests in blind ending proximal jejunum pouch with absence of a long length of the small bowel and dorsal mesentery. Terminal ileum distal to the atresia assumes apple peel.

Question 14

Bilous vomiting AFTER first 24 hours is indicative of?

Answer 14

Intestinal stenosis and atresia / below the second part of the dudodenum.

Question 15

In lung transplantations, what is primarily damaged in chronic rejection?

Answer 15

The small airways - causing bronchiolitis obliterans syndrome. Symptoms include dyspnea and wheezing.

Question 16

Deletion or insertion of any number of nucleotides that are no multiples of three is called what?

Answer 16

Frameshift mutation. Results in entirely different kind of protein. Often premature stop codon.

Question 17

What is the key difference between benign lymph node hyperplasia and malignant lymph node?

Answer 17

In benign lymph node hyperplasia, there is polyclonal proliferation. In malignant lymph node hyperplasia, it is usually a MONOCLONAL proliferation. Monoclonal re-arrangement of genes for immunoglobulin variable/TCR regions is highly suggestive of a B cell lymphoma.

Question 18

What is the pathogenesis/biology of primary pulmonary arterial hypertension?

Answer 18

Abnormal BMPR2 gene that increases predisposition to pulmonary vascular disease. Second insult then activates disease process, resulting in vascular smooth muscle proliferation, thrombosis of pulmonary arterioles, endothelial cell growth, elevated pulmonary pressures. Eventually, leads to right ventricle hypertrophy and core pulmonale.

Question 19

Polydipsia, polyuria, bipolar disorder sounds LIKE WHAT?

Answer 19

LITHIUM induced nephrogenic diabetes inspidus in which lithium acts like ADH antagonist in the collecting ducts of the system.

Question 20

What are interferon alpha and beta? How do they work?

Answer 20

Interferon alpha and beta are type I interferons that are produced by virally infected cells. These then act on locally uninfected syncells, and primes them for infection. These primed cells synthesis RNALigase L which degrades viral and host mRNA and protein kinase R which inhibits viral AND HOST protein synthesis. it basically results in apoptosis. these are different from type 2 interferon - interferon gamma which is secreted by Th1 cells for macrophage activation and induction of MHC Class II

Question 21

KNOW HOW TO FREAKING SEE AUER RODS. What disease are they seen in? What do they stain?

Answer 21

Acute myelocytic leukemia, epsecially of the M3 subtype. Auer rods are cytoplasmic inclusion rods, azurophliic, that are peroxidase positive.

Question 22

What is terminal deoxynucleotidyl transferase?

Answer 22

Responsible for adding nucleotides to VDJ regions of the antibody gene for antibody diversity. It is a marker for immature B and T lymphocytes. Found in ALL.

Question 23

Hypokalemia, low plasma renin and hypertension is indicative of what?

Answer 23

Primary aldonsteronism. Condition characterized by hypokalemia, metabolic alkolosis.

Question 24

Why is hypernatremia not seen in primary aldosteronism?

Answer 24

Tihis is the aldosterone escape. The increased Na+ and Cl reabsorption leads to hypervolemia. This in turn triggers the release of ANP which promotes diuresis and eventual sodium excretion.

Question 25

Which cells divert some of their glycolysis intermediates to reaction catalyzed by biphosphoglycerate mutase rather than use the intermediate for energy?

Answer 25

RBCS. They go through this pathway to make 2,3 BPG which is important in enabling RBCs to deliver O2 to itissues in the periphery with low blood O2 concentration because 2,3 BPG decreases affinity of Hb for oxygen.

Question 26

Platelets predominiantly express which COX enzyme.

Answer 26

COX 1. Therefore celecoxib would not have anti platelet actions.

Question 27

What humanized IgG1 monoclonal antibody that binds with IGE is used to prevent allergic reactions

Answer 27

Omalizumab

Question 28

Which picornavirus are acid labile?

Answer 28

Rhinovirus - therefore can’t colonize the GI tract