Amboss Hints

Question 1

Lambert-Eaton myasthenic syndrome (LEMS) pathophysiology?

Answer 1

Autoantibodies agains P/Q voltage-gated calcium channels at the myoneural junction that impair the release of acetylcholine

Question 2

Why clinical signs of cyanosis occurs as a result of inhaled NO?
(The mainstay treatment for PPHN)

Answer 2

Because NO causes oxidation of ferrous iron (Fe2+) to ferric iron (Fe3+) at high levels, resulting in the formation of methemoglobin

Question 3

What is the most common upper extremity neuropathy?

Answer 3

CTS

Carpal tunnel syndrome

Question 4

What conditions are associated with carpal tunnel syndrome?

Answer 4

Pregnancy
hypothyroidism
rheumatoid arthritis
acromegaly

Question 5

Ulnar nerve entrapment occurs at…….?

Answer 5

1) cubital tunnel in the elbow

2) ulnar tunnel (Guyon’s canal) in the hand

Question 6

What nerve injury causes wrist drop?

Answer 6

posterior interosseous nerve (PIN), a branch of the radial nerve

Question 7

Key features for differentiating HHS and DKA?

Answer 7

1)DKA:ketones are formed because there is no endogenous insulin
HHS برعکس
2)DKA: lower Bicarbonate

Question 8

B2 deficiency symptoms?

Answer 8

seborrheic dermatitis (erythematous rash with fine yellow scales)
pharyngeal hyperemia
glossitis, cheilitis, angular stomatitis,
normocytic-normochromic anemia The increased activity coefficient of erythrocyte glutathione reductase confirms this diagnosis.

Question 9

riboflavin (vitamin B2) serves as a redox cofactor for various enzymes, including …..?

Answer 9

pyruvate dehydrogenase α-ketoglutarate dehydrogenase succinate dehydrogenase glutathione reductase

Question 10

Vitamin B5 deficiency symptoms

Answer 10

Adrenal insufficiency
Enteritis
Alopecia
Neurological symptoms (paresthesias, numbness)

Question 11

Pyridoxal phosphate, the active form of vitamin B6, is used as a cofactor, for ….?

Answer 11

cysthathione synthesis, protein catabolism, and heme synthesis

Question 12

Vitamin B6 deficiency symptoms?

Answer 12

stomatitis, cheilosis
seborrheic dermatitis
sideroblastic anemia due to impaired heme synthesis, which is microcytic, not normocytic. Diagnosis is confirmed by direct measurement of plasma pyridoxal phosphate concentration

Question 13

Niacin deficiency is confirmed by measuring …

Answer 13

serum levels of tryptophan or erythrocyte NAD/NADP ratio.

Question 14

Diagnosis of B1 deficidncy can be confirmed by …

Answer 14

measuring the transketolase activity in RBCs following administration of thiamine.

Question 15

What is the most common side effect of topical corticosteroid use

Answer 15

Skin thinning

Question 16

What is the MOA of corticosteroids?

Answer 16

bind to intracellular glucocorticoid receptors, forming a complex that translocates into the nucleus, where it interacts with specific DNA sequences. The complex :
1)activates IκB, which inhibits the function of NF-κB, a transcription factor that normally promotes expression of numerous pro-inflammatory cytokine genes. 2)It also inhibits production of arachidonic acid derivatives by inhibiting phospholipase A2.

Question 17

Chronic, systemic corticosteroid use is associated with increased risk of developing cutaneous SCC and BCC but not dysplastic nevi or melanoma.

Answer 17

Topical corticosteroid use is not known to increase the risk of any skin cancer type.

Question 18

What translocation can be seen in 75% of Burkitt lymphoma?

Risk factors?

Answer 18

t(8;14) , which results in c-myc gene dysregulation on chromosome 8. C-myc is a proto-oncogene .

1) chronic EBV infection predisposes to translocation t(8;14).
2) Sporadic Burkitt lymphoma is associated with HIV

Question 19

Diseases due to translocations?

Answer 19

8,14 burkitt
14,18 follicular lymphoma
9,22 CML
11,14 mantle cell lymphoma
11,22 Ewing sarcoma
15,17 acute promyelocytic leukemia (APL)
12,21 ALL

Question 20

Anemia in vitamin deficiency

Answer 20

B2 normocytic
B6 microcytic
B9,B12 macrocytic