Random USMLE Facts volume 2-8

Rahul's Noteblog Notes on USMLE facts, Exam Tips, and USMLE Lab Values Random USMLE Facts volume 2-8

Random USMLE Facts volume 2-8:

USMLE Facts 1	USMLE Facts 2	USMLE Facts 3	USMLE Facts 4	USMLE Facts 5
USMLE Facts 6	USMLE Facts 7	USMLE Facts 8	USMLE Facts 9	USMLE Facts 10

What is the most important virulence factor of E. coli?

Fimbrial antigen.

What are the most common causes and findings in homocystinuria / homocystinemia?

Causes: Cobalamin (vitamin B12 deficiency). There is decreased conversion of homocystine and methyltetrahydrofolate to methionine and tetrahydrofolate.
Findings: Poor feeding, developmental delay, megaloblastic anemia, high plasma homocystine levels.

What are the findings and causes of T3 syndrome (euthyroid sick syndrome)?

T4 and TSH are normal, but T3 is low. This happens due to systemic illnesses like pneumonia or septicemia, surgery, malnutrition, or starvation.

What is the most common complication of preeclampsia in pregnancy?

Cerebral hemorrhage and adult respiratory distress syndrome.

Discuss the two types of severe combined immunodeficiency syndromes (SCID):

• X-linked: defective IL-2 receptor (most common).
• Adenosine deaminase deficiency: decreased activity of ribonucleotide reductase (second most common).

What are Downey cells?

These are seen in infectious mononucleosis (caused by EBV or CMV). They are atypical reactive lymphocytes. EBV is confirmed by heterophile antibody test.

What is a virus that cannot infect without its coat?

Reovirus - it is not active in the absence of its polymerase enzyme.

How is the diagnosis of NSAID-induced(?) chronic gastritis made?

By administering pentagastrin; this compound results in less-than-expected increase in gastric acid secretion.

Digestive tumors and their draining:

• Tumors of penis, vagina, anal canal: superficial group of inguinal lymph nodes.
• Tumors from ascending colon: mesenteric nodes.
• Tumors duodenum: do not metastasize, but spread to lymph nodes around duodenum, pancreas, stomach, liver.
• Tumors of stomach: left supraclavicular nodes.
• Tumors from transverse colon: mesenteric nodes.

What is the difference between carcinoid syndrome and pheochromocytoma?

• Carcinoid syndrome: diarrhea, flushing, wheezing; increased 5-HIAA. Tumor symptoms may be triggered by excessive eating and/or drinking alcohol. Affects right side of the heart; may lead to pulmonic stenosis or restrictive cardiomyopathy.
• Pheochromocytoma: hypertension, palpitations, headache, vomiting; increased VMA; cold clammy skin.

What fatal complication may occur one week after an acute myocardial infarction? What's Beck's triad?

Rupture of the free left ventricular wall. After rupture, cardiac tamponade occurs and the patient dies of cardiogenic shock. Beck's triad: cardiac tamponade, jugulovenous distension, muffled heart sounds. Arrhythmia is also a fatal complication of acute myocardial infarction, but there is no Beck's triad.

What metabolic disorder occurs after cardiopulmonary arrest?

Mixed acidosis. There is lactic acidosis (metabolic acidosis) due to poorly perused tissues, together with respiratory acidosis due to ventilatory malfunction.

USMLE Facts 1	USMLE Facts 2	USMLE Facts 3	USMLE Facts 4	USMLE Facts 5
USMLE Facts 6	USMLE Facts 7	USMLE Facts 8	USMLE Facts 9	USMLE Facts 10

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