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Alcohol metabolism related clinical problems (Multiple choice questions with brief answers)
A. Iron and folic acid
B. High protein diet
C. Ketogenic diet
D. Supplementation with carnitine
E. Folic acid and B12
2) – A 50-year-old homeless man was brought to the emergency room in a stuporous state. Below are his lab results, Bicarbonate 10mEq/L (22-28), pH 7.2 (7.35-7.45), PCO2 25mmHg (35-45), Alcohol 40mmol/L (0), Osmolality 370mOsm/L (280-295), Glucose 50mg/dl (65-110) BUN 40mg/dl (8-25). What is the acid-base status?
A. Metabolic acidosis and metabolic alkalosis
B. Metabolic acidosis with partial respiratory compensation
C. Respiratory acidosis and partial metabolic compensation
D. Respiratory acidosis
E. Metabolic alkalosis.
3) – A 3-year-old girl was brought into the Emergency Room. She was cold and clammy and was breathing rapidly. She was obviously confused and lethargic. Her mother indicated that she had accidentally ingested automobile antifreeze while playing in the garage. Following gastrointestinal lavage and activated charcoal administration, a nasogastric tube for ethanol was administered. How will ethanol help in relieving the symptoms?
A. Conjugate with ethylene glycol to form a soluble compound
B. Inhibit the activity of alcohol dehydrogenase
C. Inhibit the binding of ethylene glycol to alcohol dehydrogenase
D. Promote the excretion of metabolite of ethylene glycol
E. Stimulate the activity of acetaldehyde dehydrogenase.
4) – After excessive drinking over an extended period of time while eating poorly, a middle-aged man is admitted to the hospital with “high output” heart failure. Which of the following enzymes is most likely inhibited?
B. Citrate synthase
C. Isocitrate dehydrogenase
D. α-Ketoglutarate dehydrogenase
E. Succinate thiokinase
5)- Asians and Native Americans may flush and feel ill after drinking a small amount of ethanol in alcoholic beverages. This reaction is due to genetic variation in an enzyme that metabolizes the liver metabolite of alcohol, which is-
6) – A 25-year-old man is brought to the emergency room after a motor vehicle accident. He has a dislocated hip, rib fractures and a facial laceration. Toxicology screen shows a high level of ethanol in his blood. Oxidation of ethanol produces acetaldehyde and NADH. A high level of NADH relative to NAD + promotes the conversion of which of the following reactions?
A. Dihydroxyacetone phosphate to glycerol-3-P
B. Citrate to Isocitrate
C. Pyruvate to Acetyl co A
D. Malate to oxaloacetate
E. Succinate to Fumarate
7) – A 57-year-old alcoholic is transported to the emergency room after sustaining an injury in a motor vehicle accident. A comprehensive metabolic panel and a serum γ- glutamyl transferase (GGT) level are ordered. The GGT is shown to be dramatically elevated. Apart from its role as a marker of alcoholism, this enzyme is also important for which of the following digestive processes?
A. Recycling of bile salts
B. Absorption of carbohydrates
C. Digestion of triglycerides
D. Absorption of amino acids
E. Digestion of carbohydrates
8) – A 55-year-old chronic alcoholic was brought to emergency by his friends. During their night-time gathering in the local bar he fell unconscious and they had been unable to revive him. The attending physician ordered for I/V Glucose and an injection of Thiamine. The patient was well oriented and alert next morning, his vital signs were stable, blood glucose was normal and he was discharged from the hospital. Which of the following enzymes is thiamine dependent and vital for glucose oxidation in brain?
C. Lactate dehydrogenase
D. Pyruvate dehydrogenase complex
E. Citrate synthase.
9) A 42-year-old executive complained of fatigue and some recent alterations in mental status, such as forgetting appointments. He traveled outside the United States 2 months ago on a business meeting. He had vague right upper quadrant pain on deep palpation and borderline enlargement of the liver. Lab findings include-Serum AST = 120 U/L, ALT = 80 U/L, ALP = 68 U/L , GGT = 170U/L, Total bilirubin = 0.8mg/dL, Blood glucose = 60 mg/dL, Serum uric acid = 9.8 mg/dL, CBC and urinalysis results are normal. The patient is suffering from alcohol related liver disease. Which of the enzyme estimations is most diagnostic for alcohol related liver disease?
10) A 45 -year-old male was brought to the emergency department after a family member found him extremely confused and disoriented. He had an unsteady gait and strange irregular eye movements. The patient had been a known heavy drinker from the past 6 years.
There was no history of any known medical problem and he denied any other drug usage. On examination, he was afebrile with a pulse of 90 beats per minute and a normal blood pressure of 110/80 mmHg. Chest and abdominal examination were normal. He was extremely disoriented and agitated. Horizontal rapid eye movements on lateral gaze were noted bilaterally. His gait was very unsteady. The remainder of his examination was normal. The urine drug screen was negative and he had a positive blood alcohol level. Blood pyruvate and lactate levels were high. Which of the following nutrients might help in relieving the symptoms of this patient?
A. High carbohydrate diet
B. Ketogenic diet
C. Supplementation with Thiamine
D. Both A and B
E. Both B and C.
Key to answers
1) – E- Folic acid and B12
Most probably the patient is suffering from megaloblastic anemia due to cobalamine deficiency. The cause for this anemia is dietary deficiency which is very common in chronic alcoholics. Abstinence from alcohol and supplementation with B12 and folate.
2) – B- Metabolic acidosis with partial respiratory compensation.
Low pH and low bicarbonate are indicative of metabolic acidosis, which is usually compensated by hyperventilation to maintain the bicarbonate to carbonic acid ratio. The pCO2 is not very low in this patient, signifying partial compensation. The patient is alcoholic and has hypoglycemia, thus the underlying cause for metabolic acidosis is apparently lactic acidosis and ketoacidosis.
3) – C. Inhibit the binding of ethylene glycol to alcohol dehydrogenase.
Ethylene glycol is metabolized by the same enzyme system as ethanol to form toxic products that can cause severe acidosis and renal damage. Ethanol with least km is a true substrate for alcohol dehydrogenase and hence given as an antidote, it inhibit the binding of ethylene glycol to enzyme. The metabolism of ethylene glycol is thus inhibited.
4) – D. α-Ketoglutarate dehydrogenase.
The patient is most probably suffering from cardiac beriberi. The above said patient is a known alcoholic, mal nourished, and has heart failure .The probable diagnosis is Thiamine deficiency, which can be confirmed by Erythrocyte transketolase activity. In the given list of enzymes, α-Ketoglutarate dehydrogenase is the only enzyme which is Thiamine dependent. It is a multienzyme complex, requiring thiamine, lipoic acid, pantothenic acid, riboflavin and niacin as coenzymes.
5) – C. Acetaldehyde.
In some Asian populations and Native Americans, alcohol consumption results in increased adverse reactions to acetaldehyde owing to a genetic defect of mitochondrial aldehyde dehydrogenase. The acetaldehyde formed from alcohol is oxidized in the liver in a reaction catalyzed by mitochondrial NAD-dependent aldehyde dehydrogenase (ALDH).
6) – A. – Dihydroxyacetone-P to Glycerol-3-P
Alcohol is metabolized in two steps by two NAD + requiring enzymes. Chronic alcohol consumption leads to build up of NADH, that changes the redox state of the hepatocytes. As a result the equilibrium of many reactions is shifted towards regeneration of NAD +. Out of the given list, its only the conversion of dihydroxyacetone-P which is likely to be effective.
7) – D. Absorption of amino acids
8) D- Pyruvate dehydrogenase complex
10) – E- Both B and C- Ketogenic diet and thiamine supplementation
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