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epica

08/24/07 - 11:39 PM

For step 2 and 1

A 62-year-old man with a 20-year history of alcoholism is admitted to the hospital for treatment of alcoholic hepatitis. He appears disheveled and malnourished. He is 198 cm (6 ft 6 in) tall and weighs 70 kg (155 lb); BMI is 18 kg/m2. Examination shows jaundice and temporal wasting. Scattered rhonchi are heard throughout all lung fields. Cardiac examination shows no abnormalities. Bowel sounds are normal. The liver span is 16 cm. Sensation to pinprick and light touch is decreased over the feet. Deep tendon reflexes are decreased at the ankles. Laboratory studies show:

Hematocrit 33%

Platelet count 145,000/mm3

Serum

Na+ 131 mEq/L

Cl– 92 mEq/L

K+ 3.1 mEq/L

HCO3– 26 mEq/L

Mg2+ 0.8 mEq/L

Ca2+ 5.8 mg/dL

Urea nitrogen (BUN) 6 mg/dL

Creatinine 0.8 mg/dL

Test of the stool for occult blood is positive. Which of the following is the most likely mechanism of this patient's hypocalcemia?

A ) Chronic metabolic acidosis

B ) Hypomagnesemia

C ) Impaired hydroxylation of vitamin D

D ) Primary hyperparathyroidism

E ) Renal resistance to parathyroid hormone

new_n_lost
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08/25/07 - 12:03 AM

B ) Hypomagnesemia >> common in Alcohol Dependence ??

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new_n_lost
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08/25/07 - 12:07 AM

C ) Impaired hydroxylation of vitamin D

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epica

08/25/07 - 12:11 AM

Sorry,
B or C?

new_n_lost
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08/25/07 - 12:13 AM

new_n_lost wrote:
B ) Hypomagnesemia >> common in Alcohol Dependence ??

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"never argue with a fool, they'll bring you down to their level and beat you with experience" FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."

epica

08/25/07 - 12:15 AM

Ig F
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02/08/08 - 07:39 AM

chronic alcohol intake leads to Hypomagnesemia........but can some1 please explain the mechanism....

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pr20
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02/08/08 - 08:42 PM

PTH binds to Gs membrane receptor--->activates adenylate cyclase----->generates cAMP--->activates protein kinase A.
Magnesium is a cofactor for adenylate cyclase,which generates cAMP(required for PTH action)
So hypomagnesemia inhibits PTH activity.
It also inhibits synthesis and release of PTH.

Ig F
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02/09/08 - 08:00 AM

thanks pr20....

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