Kaplan- Endo

Question 1

a 52 y.o. woman with heat intolerance, exopthalmos and sinus tachycardia likely has what disease
what is the mechanism?

Answer 1

Grave’s disease:

hyperthyroidism is caused by autoantibodies against TSH receptor that activate it

Question 2

how is Grave’s disease differentiated from Hashimoto’s thyroiditis in terms of symptomology and type of immune reaction

Answer 2

Grave’s causes hyperthyroidism, Hashimoto’s causes hypothyroidism

Graves is type II noncytotoxic hypersensitivity reaction
Hashimoto’s is a type IV cytotoxic hypersensitivity reaction

Question 3

what are the three P’s of multiple endocrine neoplasia type 1

Answer 3

neoplasias of the parathyroid, pituitary, and pancreas

Question 4

what’s the range of normal prolactin

Answer 4

normal prolactin < 20ng/mL

Question 5

which hormone is responsible for regulating plasma sodium concentration with varying salt intake

Answer 5

ADH, not aldosterone
ADH is very sensitive to changes in plasma sodium and responds rapidly to increase water reabsorption in response to increased sodium

aldosterone can only uptake salt and water and in equal amounts so this doesn’t help regulate conc.

Question 6

what is the thyroid gland like in Hashimoto’s

Answer 6

enlarged and uniformly firm due to chronic inflammation

Question 7

what antibodies characterize Hashimoto’s thyroiditis

Answer 7

anti-thyroid peroxidase and anti-thyroglobulin

Question 8

do angiofibromas and lipomas tend to occur more with MEN type 1 or 2
what about pituitary adenomas

Answer 8

angiofibromas and lipomas=type 1

pituitary adenomas=also type 1

Question 9

a child with short stature, shortened 4th and 5th metacarpals, low serum Ca2+, high serum phosphate and high serum PTH likely has a defect in what molecule
what’s the disease

Answer 9

stimulatory Gs protein PTH receptor leading to failure to raise cAMP in response to PTH

this disease is pseudohypoparathyroidism (defective PTH receptor leading to low Ca)

Question 10

what are normal levels for serum Ca2+

Answer 10

8.4-10.2 mg/dL

Question 11

what are Trousseau and Chvostek’s signs and what imbalance do they signify

Answer 11

Trousseau: carpal spasm after application of BP cuff
Chvostek: facial muscle upon tapping in front of the ear

these signs suggest hypocalcemia

Question 12

activity of which enzyme –that catalyzes the rate limiting step in fatty acid synthesis– is upregulated by insulin

Answer 12

acetyl CoA carboxylase

Question 13

why might a euthyroid pregnant woman with palpitations, heat intolerance and weight gain have high T4 and normal TSH

Answer 13

• estrogen in pregnancy causes an increase in TBG such that free T4 remains the same, but total serum T4 increases
• TSH is normal because free levels of thyroid influence its secretion, not bound levels
• palpitations and heat intolerance are normal in pregnancy

Question 14

what are four treatments that would be given to manage a patient with DKA

Answer 14

1. insulin therapy
2. IV fluids (to manage dehydration)
3. dextrose (to prevent hypoglycemia during Tx)
4. potassium (to prevent hypokalemia during Tx)

Question 15

what kind of diabetes monotherapy would you prefer to use in a patient with comorbid kidney disease and heart disease

Answer 15

a second generation sulfonylurea such as glipizide, glyburide or glimeburide
(can’t use metformin due to acidosis toxicity, can’t use glitazones/ thiazolidinediones due to cardiac tox)

Question 16

the presence of amyloid on FNA suggests what type of thyroid cancer?
what causes this amyloid to accumulate?
what cells proliferate?

Answer 16

medullary thyroid carcinoma;
neuroendocrine parafollicular cells proliferate, leading to build up of the precursor protein to calcitonin which then precipitates and forms amyloid sheets

Question 17

what are the sites of somatostatin release and what hormones does it inhibit

Answer 17

somatostatin is release from the hypothalamus, pancreas and GI mucosa

somatostatin inhibits GH and TSH

Question 18

a patient presenting with DKA and peaked T waves on EKG likely has what electrolyte imbalance

Answer 18

hyperkalemia (as well as low bicarb due to acidosis)

Question 19

up to what size is a lump in the breast of a pubertal boy no cause for concern

Answer 19

pubertal boys often get asymmetric lumps in the breast tissue
up to 4cm in diameter is normal

Question 20

what does cortisol do to glucose uptake, gluconeogenesis, lipolysis and amino acid levels in blood

Answer 20

cortisol decreases glucose uptake by muscle and adipocytes, increases gluconeogenesis, increases lipolysis and increases circulating amino acid levels

Question 21

would defective 11-beta-hydroxylase cause decreased or increased deoxycorticosterone

Answer 21

increased 11-deoxycorticosterone because 11-beta hydroxylase convertse deoxycorticosterone to corticosterone

Question 22

cutting off circulation between hypothalamus and pituitary would cause an increase in which hormone

Answer 22

prolactin:

dopamine from hypothalamus exerts negative regulation of pituitary lactotrophs

Question 23

would a patient with hyperparathyroidism secondary to end-stage renal disease have high or low Ca;
how would you treat the patient’s hyperparathyroidism

Answer 23

secondary hyperparathyroidism occurs in response to low Ca2+ (due to poor Ca2+ reabsorption in kidneys and calcium phosphate precipitation into urine)

treat with a sensitizer for Ca2+ receptor on parathyroid chief cells to downregulate PTH (i.e. Cinacalcet)

Question 24

a patient with defective ACTH receptor will have normal levels of what hormone secreted by the adrenal cortex
from what layer is it secreted?

Answer 24

aldosterone: secretion of aldosterone from the zona glomerulosa is unaffected by ACTH action

Question 25

which class of diabetes drugs are contraindicated in patients with heart failure and how do they work

Answer 25

glitazones/ thiazolidinediones work by sensitizing peripheral tissues to insulin via upregulation of PPAR-gamma activity (increasing adiponectin and decreasing resistin)

Question 26

a patient with a 2.5cm neckmass and increased serum calcitonin likely has what cancer; what genetic neoplastic syndrome could this patient have

Answer 26

medullary thryroid cancer
(hyperplastic parafollicular cells produce calcitonin)

often seen in MEN2a and 2b (along with pheos)

Question 27

what happens to PTH in acute vs. chronic hypomagnesemia

Answer 27

in acute hypomagnesemia PTH is increased; in chronic severe hypomagnesemia PTH is decreased