PTH and others

Question 1

The best screening test for virilizing neoplasm in a woman( rapid development of androgenic sxs with virilization? Explain?

Answer 1

Serum Testosterone n DHEAS( sulfates DHEA).
- AS, DHEA, T r produced both in the ovaries n adrenals. DHEAS is predominantly produced by adrenals. Therefore, elevated testosterone with normal DHEAS indicates an ovarian source n nearly normal T with elevated DHEAS indicates an adrenal source

Question 2

A pt presented with dark urine after being treated for UTI. Urine stain for purssian blue is positive
What’s the dx?

Answer 2

G6PD deficiency causing hemolytic anemia.

- hemolytic episodes can b triggered by eg. sulfa drugs

Question 3

A pt presented with episodic flushing, secretory diarrhea, bronchospasm, valvular dis
What vitamin deficiency is expected ?

Answer 3

Carcinoid syndrome causes high serotonin production from tryptophan ( also required for niacin synthesis—> niacin deficiency)

Question 4

When parathyroid surgery is not possible, what meds will u give?

Answer 4

Cincalcet, which inhibits release of PTH

Question 5

Indications for PTH surgery in asymptomatic pts

Answer 5

1) serum Ca level>1 mg/dL above normal
2) age<50yr
3) bone mineral density
4) reduced renal function GFR<60x

Question 6

Most accurate test in diagnosing paget disease of the bones is

Answer 6

Nuclear bone scan

Question 7

Constipation, abdominal pain, polydipsia, polyuria

Answer 7

Hypercalcemia

Question 8

Hypomagnesemia causing hypocalcemia: what happens to phosphate level?

Answer 8

Inducing PTH resistance n decreasing PTH release

- phosphate stays normal or low.

Question 9

Rx of paget disease when asymptomatic or symptomatic

Answer 9

Asymptomatic- no Rx needed
Symptomatic- bisphosphonates ( inhibit osteoclasts)
2nd line Rx is calcitonin

Question 10

What effect does increased extracellular pH have on serum Ca level?

Answer 10

Increase the affinity of serum albumin to calcium-> decrease ionized Ca( the only physiologically active form)
This is how hyperventilation/resp alkalosis causes hypocalcemia

Question 11

Breast ca causes hypercalcemia most commonly by which mechanism?

Answer 11

By producing PTHrP

Question 12

The standard Rx for primary hyperparathyroidism is?

Answer 12

Surgical removal of the glands

Question 13

The most common cause of hypercalcemia is?

Answer 13

Primary hyperparathyroidism

Question 14

Hypercalcemia of malignancy is most commonly due to?

- other causes include?

Answer 14

PTHrP production in 80% of cases
Others include
- excess vit D production
- bone Mets with local cytokine release n bone resorption
- ectopic PTH production

Question 15

The most common presentation of paget disease of the bone is ?

Answer 15

Asymptomatic elevation of ALP.

When symptomatic, bone pain is the most common symptom.

Question 16

PCOS diagnostic criteria

Answer 16

1) androgen excess(biochemical or clinical) 2. Oligo/unovulation( menstrual irregularities)
3) U/S ( not a requirement, 2 of the above r enough to make the dx).

Question 17

1st line Rx for PCOS pt who’s not currently interested in child bearing?
1stline for ovulation induction?

Answer 17

Wt loss n combined OCPs

- clomiphen for ovulation induction

Question 18

Insulin resistance n DM r better detected using— test in PCOS

Answer 18

75g 2hr oral glucose tolerance test

Question 19

What’s the place of progesterone analogs in cancer Rx?

Answer 19

Appetite n weight improvement in Ca related anorexia/ cachexia syndrome

Question 20

Spontaneous early morning n REM Sleep erection rules out?

Answer 20

Organic causes of erectile dysfunction.