[MCQs] Megaloblastic Anemias - Part 4

I. Start the exam by click the “Start” button

Megaloblastic Anemias- Part 4

Please wait while the activity loads.
If this activity does not load, try refreshing your browser. Also, this page requires javascript. Please visit using a browser with javascript enabled.

If loading fails, click here to try again

Start

Congratulations - you have completed Megaloblastic Anemias- Part 4. You scored %%SCORE%% out of %%TOTAL%%. Your performance has been rated as %%RATING%%

Your answers are highlighted below.

Question 1

Conditions that increase demand of folic acid are all except ?

A	Chronic hemolytic anemias
B	Pregnancy
C	Hemodialysis
D	Tropical sprue

Question 1 Explanation:

The mechanism of folic acid deficiency in tropical sprue is malabsorption. Rest of the above conditions lead to increased folic acid requirements and cause megaloblastic anemia

Question 2

Folate deficiency frequently occurs in which of the following ?

A	Sickle cell disease
B	Autoimmune hemolytic anemia
C	Congenital spherocytosis
D	All of the above

Question 2 Explanation:

Folate deficiency frequently occurs in chronic hemolytic anemia, particularly in sickle cell disease, autoimmune hemolytic anemia, and congenital spherocytosis.

Question 3

Alcohol causes folic acid deficiency by which of the following mechnism ?

A	Inadequate intake
B	Increased requirements
C	Malabsorption
D	Impaired metabolism

Question 3 Explanation:

Alcohol interferes with folate metabolism. Distilled spirits are devoid of folic acid, while beer and wine do not contain enough of vitamin for daily requirement.

Question 4

Which of the following drugs is an inhibitor of dihydrofolate reductase ?

A	Zidovudine
B	Methotrexate
C	Azathioprine
D	All of the above

Question 5

Which of the following drugs is an inhibitor of dihydrofolate reductase ?

A	Pentamidine
B	Trimethoprim
C	Pyrimethamine
D	All of the above

Question 5 Explanation:

Drugs that inhibit DHF reductase include methotrexate, pyrimethamine & trimethoprim. Methotrexate has the most powerful action against the human enzyme, whereas trimethoprim is most active against the bacterial enzyme and is only likely to cause megaloblastic anemia when used in conjunction with sulphamethoxazole in patients with preexisting folate or cobalamin deficiency. The activity of pyrimethamine is intermediate

Question 6

In megaloblastic anemia due to folate antagonists, which of the following is given ?

A	Folic acid
B	Folinic acid
C	Pyridoxine
D	All of the above

Question 6 Explanation:

Megaloblastic anemia due to folate antagonists that inhibit dihydrofolate reductase can be counteracted by folinic acid [5-formyl tetrahydrofolate (THF)] in a dose of 100 to 200 mg/day, which circumvents the block in folate metabolism by providing a form of folate that can be converted to 5,10-methylene THF. For the megaloblastic forms of sideroblastic anemia, pyridoxine in pharmacologic doses (~300 mg/day) can be tried. Folinic Acid (5-Formyl-THF) is a stable form of fully reduced folate. It is given orally or parenterally to overcome the toxic effects of methotrexate or other DHF reductase inhibitors.

Question 7

The normal range of cobalamin in serum is ?

A	5 to 100 ng/L
B	100 to 200 ng/L
C	160 to 1000 ng/L
D	1000 to 2500 ng/L

Question 7 Explanation:

The normal range of serum cobalamin in serum is 160 - 1000 ng/L. Values between 100 & 200 ng/L are regarded as borderline.

Question 8

Serum homocysteine is raised in all except ?

A	Chronic renal disease
B	Hyperthyroidism
C	Alcoholism
D	Pyridoxine deficiency

Question 8 Explanation:

Serum homocysteine is raised in early cobalamin & folate deficiency, CKD, alcoholism, smoking, pyridoxine deficiency, hypothyroidism, steroid & cyclosporine therapy. Levels are higher in serum than in plasma, in men than in premenopausal women, in women taking HRT or oral contraceptives. Homocysteine levels are not used for diagnosis of cobalamin or folate deficiency.

Question 9

Levels of which of the following is raised in patients with cobalamin deficiency ?

A	Calcium
B	Iron
C	Serum methylmalonate (MMA)
D	Glycine

Question 9 Explanation:

Glycine

Question 10

Normal serum folic acid levels are ?

A	6 to 20 ng / mL
B	30 to 40 ng / mL
C	60 to 80 ng / mL
D	80 to 100 ng / mL

Question 11

Normal range of serum folate is ?

A	2 to 15 µg / L
B	12 to 25 µg / L
C	25 to 45 µg / L
D	42 to 75 µg / L

Question 11 Explanation:

Normal range of serum folate is 2 to 15 µg/L

Question 12

In folate deficiency due to drugs inhibiting dihydrofolate reductase, tissue folate concentrations are ?

A	Normal
B	Elevated
C	Reduced
D	Any of the above

Question 12 Explanation:

Various drugs can inhibit dihydrofolate reductase thereby producing folate deficiency. However, tissue folate concentrations remain normal.

Question 13

What value of folic acid is diagnostic of folate deficiency ?

A	<=1 ng/mL
B	<=2 ng/mL
C	<=3 ng/mL
D	<=4 ng/mL

Question 14

Which is a better index of folate stores ?

A	Serum folate level
B	RBC folate level
C	WBC folate level
D	Platelet folate level

Question 14 Explanation:

Normal serum folic acid ranges from 6 to 20 ng/mL. Values <=4 ng/mL are considered diagnostic of folate deficiency. Measurement of RBC folate level is not subject to short-term fluctuations in folate intake & is better than serum folate as an index of folate stores.

Question 15

For cobalamin maintenance therapy, 1000 µg of hydroxocobalamin IM is given ?

A	Once a month
B	Once every 2 months
C	Once every 3 months
D	Once every 6 months

Question 16

For cobalamin maintenance therapy, 1000 µg of cyanocobalamin IM is given ?

A	Once a month
B	Once every 2 months
C	Once every 3 months
D	Once every 6 months

Question 16 Explanation:

Replenishment of body stores of cobalamin is complete with six 1000-µg IM injections of hydroxocobalamin given at 3- to 7-day intervals. For maintenance therapy, 1000 µg hydroxocobalamin IM once every 3 months is satisfactory. Because of the poorer retention, cyanocobalamin is given 1000 µg IM, monthly.

Question 17

Oral dose of folic acid in folate deficiency is ?

A	5 - 15 mg for ~ 1 month
B	5 - 15 mg for ~ 4 months
C	5 - 15 mg for ~ 8 months
D	5 - 15 mg for ~ 12 months

Question 17 Explanation:

Oral dose of folic acid in folate deficiency is 5-15 mg daily for ~4 months because all folatedeficient RBC’s will be eliminated in this time.

Question 18

Long-term folic acid therapy is required in which of the following ?

A	Chronic dialysis
B	Hemolytic anemias
C	Gluten-induced enteropathy
D	All of the above

Question 18 Explanation:

Long-term folic acid therapy is required in chronic dialysis, hemolytic anemias and gluteninduced enteropathy that does not respond to gluten-free diet.

Question 19

Adenosylcobalamin is required for the conversion of ?

A	Methylmalonyl CoA to succinyl CoA
B	Succinyl CoA to Methylmalonyl CoA
C	Propionyl CoA to Methylmalonyl CoA
D	Methylmalonyl CoA to Propionyl CoA

Question 19 Explanation:

Adenosylcobalamin is required for the conversion of methylmalonyl CoA to succinyl CoA. Lack of this cofactor leads to large increases in the tissue levels of methylmalonyl CoA and its precursor, propionyl CoA. As a consequence, nonphysiologic fatty acids containing an odd number of carbon atoms are synthesized and incorporated into neuronal lipids. This biochemical abnormality may also contribute to the neurologic complications of cobalamin deficiency

Question 20

Pathway deranged in cobalamin deficiency is ?

A	Methyltetrahydrofolate to tetrahydrofolate
B	N5-methenyltetrahydrofolate to N5-methylenetetrahydrofolate
C	N5-methylenetetrahydrofolate to Dihydrofolate
D	Dihydrofolate to tetrahydrofolate

Question 20 Explanation:

Dihydrofolate to tetrahydrofolate

Question 21

Which of the following about cobalamin is false ?

A	Cobalamin is an essential cofactor for methionine synthase & methylmalonyl-CoA synthase
B	Methylcobalamin and adenosylcobalamin are metabolically active forms
C	Therapeutically available as cyanocobalamin
D	Cyanocobalamin is biologically active

Question 22

Cobalamin deficiency without anemia is common in ?

A	Infants
B	Adolescents
C	Adults
D	Elderly

Question 23

Which isoenzyme of plasma lactic acid dehydrogenase is increased in enhanced intramedullary destruction of erythroblasts ?

A	Isoenzyme 1
B	Isoenzyme 2
C	Isoenzyme 3
D	Isoenzyme 4

Question 24

Which of the following manifestations occur with cobalamin deficiency but not with folic acid deficiency ?

A	Gastrointestinal
B	Neurologic
C	Hematologic
D	All of the above

Question 24 Explanation:

All of the above

Question 25

Folic acid supplementation is required in patients on chronic hemodialysis because ?

A	Folate is lost in dialysate
B	Heparin reduces folate levels in blood
C	Protamine reduces folate levels in blood
D	All of the above

Question 25 Explanation:

Patients on chronic hemodialysis require folate supplementation to replace that lost in dialysate

Question 26

Normally, what percentage of RBC precursors are destroyed in bone marrow ?

A	10 - 15 %
B	25 - 30 %
C	50 - 60 %
D	75 - 80 %

Question 26 Explanation:

Megaloblastic anemias are characterized by ineffective erythropoiesis. In a severely megaloblastic patient, as many as 90% of RBC precursors may be destroyed before they are released into the bloodstream, compared with 10 to 15% in normal individuals

Question 27

Clinically significant deficiency of cobalamin is present when its levels are ?

A	< 100 pg / mL
B	< 200 pg / mL
C	< 300 pg / mL
D	< 400 pg / mL

Question 27 Explanation:

Values <200 pg/mL indicate clinically significant cobalamin deficienc

Question 28

Reticulocytosis after intramuscular cyanocobalamin therapy for megaloblastic anemia due to cobalamin deficiency peaks at about ?

A	Day 3
B	Day 5
C	Day 7
D	Day 10

Question 28 Explanation:

Reticulocytosis begins 4 to 5 days after intramuscular cyanocobalamin therapy is started & peaks at ~ day 7. If reticulocytosis does not occur, or if it is less brisk than expected from the level of hematocrit, other factors contributing to anemia (infection, coexisting iron and/or folate deficiency, or hypothyroidism) need to be looked.

Once you are finished, click the button below. Any items you have not completed will be marked incorrect. Get Results

There are 28 questions to complete.

←

List

→

Return

Shaded items are complete.

1	2	3	4	5
6	7	8	9	10
11	12	13	14	15
16	17	18	19	20
21	22	23	24	25
26	27	28	End

Return

See all quizzes of the Megaloblastic Anemias at here:

Megaloblastic Anemias – Part 1 | Megaloblastic Anemias – Part 2 | Megaloblastic Anemias – Part 3 | Megaloblastic Anemias – Part 4

II. Preview all questions below

1.Conditions that increase demand of folic acid are all except ?
A. Chronic hemolytic anemias
B. Pregnancy
C. Hemodialysis
D. Tropical sprue

2. Folate deficiency frequently occurs in which of the following ?
A. Sickle cell disease

B. Autoimmune hemolytic anemia
C. Congenital spherocytosis
D. All of the above

3. Alcohol causes folic acid deficiency by which of the following mechnism ?
A. Inadequate intake
B. Increased requirements
C. Malabsorption
D. Impaired metabolism

4. Which of the following drugs is an inhibitor of dihydrofolate reductase ?
A. Zidovudine
B. Methotrexate
C. Azathioprine
D. All of the above
5. Which of the following drugs is an inhibitor of dihydrofolate reductase ?
A. Pentamidine
B. Trimethoprim
C. Pyrimethamine
D. All of the above

6. In megaloblastic anemia due to folate antagonists, which of the following is given ?
A. Folic acid
B. Folinic acid
C. Pyridoxine
D. All of the above

7. The normal range of cobalamin in serum is ?
A. 5 to 100 ng/L
B. 100 to 200 ng/L
C. 160 to 1000 ng/L
D. 1000 to 2500 ng/L

8. Serum homocysteine is raised in all except ?
A. Chronic renal disease
B. Hyperthyroidism
C. Alcoholism
D. Pyridoxine deficiency

9. Levels of which of the following is raised in patients with cobalamin deficiency ?
A. Calcium
B. Iron
C. Serum methylmalonate (MMA)
D. Glycine

10. Normal serum folic acid levels are ?
A. 6 to 20 ng / mL
B. 30 to 40 ng / mL
C. 60 to 80 ng / mL
D. 80 to 100 ng / mL
11. Normal range of serum folate is ?
A. 2 to 15 µg / L
B. 12 to 25 µg / L
C. 25 to 45 µg / L
D. 42 to 75 µg / L

12. In folate deficiency due to drugs inhibiting dihydrofolate reductase, tissue folate concentrations are ?
A. Normal
B. Elevated
C. Reduced
D. Any of the above

13. What value of folic acid is diagnostic of folate deficiency ?
A. <=1 ng/mL
B. <=2 ng/mL
C. <=3 ng/mL
D. <=4 ng/mL
14. Which is a better index of folate stores ?
A. Serum folate level
B. RBC folate level

C. WBC folate level
D. Platelet folate level

15. For cobalamin maintenance therapy, 1000 µg of hydroxocobalamin IM is given ?
A. Once a month
B. Once every 2 months
C. Once every 3 months
D. Once every 6 months
16. For cobalamin maintenance therapy, 1000 µg of cyanocobalamin IM is given ?
A. Once a month
B. Once every 2 months
C. Once every 3 months
D. Once every 6 months

17. Oral dose of folic acid in folate deficiency is ?
A. 5 – 15 mg for ~ 1 month
B. 5 – 15 mg for ~ 4 months
C. 5 – 15 mg for ~ 8 months
D. 5 – 15 mg for ~ 12 months

18. Long-term folic acid therapy is required in which of the following ?
A. Chronic dialysis
B. Hemolytic anemias
C. Gluten-induced enteropathy
D. All of the above

19. Adenosylcobalamin is required for the conversion of ?
A. Methylmalonyl CoA to succinyl CoA
B. Succinyl CoA to Methylmalonyl CoA
C. Propionyl CoA to Methylmalonyl CoA
D. Methylmalonyl CoA to Propionyl CoA

20. Pathway deranged in cobalamin deficiency is ?

A. Methyltetrahydrofolate to tetrahydrofolate
B. N5-methenyltetrahydrofolate to N5-methylenetetrahydrofolate
C. N5-methylenetetrahydrofolate to Dihydrofolate
D. Dihydrofolate to tetrahydrofolate

21. Which of the following about cobalamin is false ?
A. Cobalamin is an essential cofactor for methionin synthase & methylmalonyl-CoA synthase
B. Methylcobalamin and adenosylcobalamin are metabolically active forms
C. Therapeutically available as cyanocobalamin
D. Cyanocobalamin is biologically active
22. Cobalamin deficiency without anemia is common in ?
A. Infants
B. Adolescents
C. Adults
D. Elderly
23. Which isoenzyme of plasma lactic acid dehydrogenase is increased in enhanced intramedullary destruction of erythroblasts ?
A. Isoenzyme 1
B. Isoenzyme 2
C. Isoenzyme 3
D. Isoenzyme 4

24. Which of the following manifestations occur with cobalamin deficiency but not with folic acid deficiency ?
A. Gastrointestinal
B. Neurologic
C. Hematologic
D. All of the above

25. Folic acid supplementation is required in patients on chronic hemodialysis because ?
A. Folate is lost in dialysate
B. Heparin reduces folate levels in blood
C. Protamine reduces folate levels in blood
D. All of the above

26. Normally, what percentage of RBC precursors are destroyed in bone marrow ?
A. 10 – 15 %
B. 25 – 30 %
C. 50 – 60 %
D. 75 – 80 %

27. Clinically significant deficiency of cobalamin is present when its levels are ?
A. < 100 pg / mL
B. < 200 pg / mL
C. < 300 pg / mL
D. < 400 pg / mL

28. Reticulocytosis after intramuscular cyanocobalamin therapy for megaloblastic anemia due to cobalamin deficiency peaks at about ?
A. Day 3
B. Day 5
C. Day 7
D. Day 10

[MCQs] Megaloblastic Anemias – Part 4

I. Start the exam by click the “Start” button

Megaloblastic Anemias- Part 4

See all quizzes of the Megaloblastic Anemias at here:

II. Preview all questions below

Share this:

Related

[MCQs] Megaloblastic Anemias- Part 3

[MCQs] Hemolytic Anemias and Anemia Due to Acute Blood Loss – Part 1

You may also like

Leave a Comment Cancel Reply