Random USMLE Facts volume 7-3

Rahul's Noteblog Notes on USMLE facts, Exam Tips, and USMLE Lab Values Random USMLE Facts volume 7-3

Random USMLE Facts volume 7-3:

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 happens to amino groups that are released during amino acid metabolism?

They are transferred to alpha-ketoglutarate to form glutamate, the primary carrier of ammonia from the liver.

What reaction is impaired in biotin deficiency?

Conversion of pyruvate to oxaloacetate.

What is the mechanism of action of anastrozole?

Decreased production of estrogen from aromatization of androgens.

What is haemophilus influenzae grown together with staphylococcus aureus?

Staphylococcus aureus provides haemophilus influenzae with the necessary NAD+ (factor V). Note that haemophilus influenzae also needs medium X (hematin) for growth.

Can maternal insulin be transferred to the fetus?

No. During maternal hyperglycemia, the fetus responds by making insulin on its own. However, after being born, the infant may experience transient hypoglycemia because insulin is continued to be produced.

What is the real meaning of positive and negative predictive values?

Positive and negative predictive values measure the prevalence of disease in a population. The more common a disease in a given population, the higher the positive predictive value, and lower the negative predictive value.

What are some side-effects of rifampin?

Red urine and red tears.

What is the significance of migratory thrombophlebitis?

Migratory thrombophlebitis means "cancer." Paraneoplastic syndrome resulting from adenocarcinomas of the pancrease, colon, and lungs, very commonly result in hypercoagulability, which causes migratory thrombophlebitis (Trousseau syndrome).

What are some different forms of heparin?

Hirudin, lepirudin, and argatroban. These drugs are direct thrombin inhibitors.

What is a factor in determining the severity of symptoms of sickle cell anemia?

The percentage of normal hemoglobin. Sickle cell patients with normal hemoglobin concentration (60% Hb A) display no symptoms except perhaps hematuria.

What is a major determinant of the ratio of forward-to-regurgitant left ventricular (LV) output in patients with mitral regurgitation (MR)?

Left ventricular afterload.

How is preload related to heart rate?

Decreased heart rate increases preload (left ventricular end diastolic volume). Thus, beta blockers can increase preload because they decrease the heart rate.

Why does hydronephrosis occur after surgery is performed around the abdominal area?

The ureter is ligated when surgery involves manipulation of the uterine artery, and this may cause hydronephrosis. Findings include flank pain and a palpable mass.

How is vitamin B₁₂ administered?

Parenterally.

How is creatine kinase released from injured cells?

When cells within the heart, brain, or skeletal muscle are injured, creatine kinase leaks across the damaged cell membrane and into circulation. Thus, cell membrane damage causes release of creatine kinase.

What is the significance of negative predictive value?

The patient tested negative truly doesn't have the disease.

What is the significance of positive predictive value?

The patient tested positive truly does have the disease.

Where is lipoprotein lipase manufactured within the body?

Uniloculated adipocytes. Note that deficiency of lipoprotein lipase causes familial hyperchylomicronemia (increased triglycerides).

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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