NBME 11, step-1 questions, need help/answers.

[highscore]

The answer indicated by the filled-in circle is mine, which is wrong. Please give explanations for the right answers, if possible. Thank You...

A 76-year-old woman comes to the physician because of severe back pain for the past 2 weeks. She has no history of smoking. She has been taking prednisone (30 mg/day) for rheumatoid arthritis for the past 6 months and has received hormone replacement therapy with estrogen and progesterone for the past 15 years. Calcium and vitamin D intake are adequate. X-rays of the spine show a vertebral fracture. Which of the following is the most likely cause of the fracture?​

A. Decreased bone formation due to decreased calcium absorption
B. Decreased bone formation due to inhibition of osteoblast differentiation
C. Increased bone resorption due to decreased calcium absorption
D. Increased bone resorption due to decreased serum parathyroid hormone concentration
E. Increased bone resorption due to estrogen receptor defect

A 49-year-old woman comes to the emergency department because of a 3-day history of fever, shortness of breath, and confusion. She is a postal worker. Her temperature is 38.4°C (101.2°F), respirations are 28/min, and blood pressure is 100/60 mm Hg. Physical examination shows nuchal rigidity. Breath sounds are decreased on the right side of the chest. A lumbar puncture is done. Analysis of cerebrospinal fluid (CSF) shows:​

Glucose: 18 mg/dL
Total protein: 138 mg/dL
Leukocyte count: 638/mm3
Segmented neutrophils: 87%
Monocytes: 13%
RBC: 2300/mm3

A Gram stain of CSF shows large, gram-positive, spore-forming bacilli. A chest x-ray shows marked widening of the mediastinum. Which of the following extracellular virulence factors most likely enables the causal organism to evade phagocytosis?​

A. Alginate
B. Glucuronoxylomannan
C. Hyaluronic acid
D. Polyglutamic acid
E. Polyribitol phosphate

A 45-year-old man with recently diagnosed early-onset Parkinson disease comes to the physician for a follow-up examination. He has a long history of major depressive disorder successfully treated with fluoxetine. Treatment with which of the following antiparkinsonian drugs is contraindicated in this patient?​

A. Amantadine
B. Benztropine
C. Levodopa
D. Ropinirole
E. Selegiline

A 37-year-old man comes to the emergency department because of a 10-day history of yellow skin, vague abdominal discomfort, and fatigue. His vital signs are within normal limits. Physical examination shows generalized icterus. Serum studies show:​

AST: 320 U/L
ALT: 340 U/L
Hepatitis B surface antigen(HBsAg): positiveIgM
anti-hepatitis B core antigen(HBcAg): positive
Anti-hepatitis D virus: negative

Direct damage to infected hepatocytes in this patient is most likely mediated predominantly by which of the following?​

A. Antibody against HBcAg
B. Antibody against HBsAg
C. Complement via the alternate pathway
D. Cytotoxic T lymphocytes
E. Viral cytopathic effect

A 6-year-old girl is brought to the physician by her mother because of a 2-week history of increased thirst and a 3-kg (6.6-lb) weight loss. Her mother says that the patient is constantly drinking water. She is at the 75th percentile for height and 50th percentile for weight. Physical examination shows tachypnea and dehydration. Laboratory studies show hyperglycemia, metabolic acidosis, and ketonemia. If a biopsy specimen were obtained from this patient's pancreas, which of the following findings in islet cells would now be most likely?​

A. Basement membrane thickening of capillaries
B. Cellular necrosis and lymphocytic infiltration
C. Decrease in mass and deposition of amyloid
D. Large β cells and nuclei
E. Marked atrophy and fibrosis

Two programs for the treatment of patients with newly detected hypercholesterolemia were tried in a community. Program A was used in one district of the community, and Program B was used in another. After four years, 45% of the 2200 patients on Program A and 49% of the 1900 patients on Program B had been successfully treated for hypercholesterolemia. The difference between the success rates for the two programs was statistically significant (p < .01). Health officials, however, decided not to change to Program B in the first district because the magnitude of the difference was so small. Which of the following best explains their decision?​

A. They attributed the difference in success rates to chance alone
B. They distinguished between statistical significance and practical importance of the difference in success rates
C. They felt the p value was too small to justify a decision in favor of Program B
D. They felt the samples were too small to justify a decision in favor of Program B

During a 5-year study at a hospital, data about antimicrobial drug use for respiratory infections and antimicrobial susceptibility for respiratory isolates are compiled. At the end of 5 years, the data show that levofloxacin was the most common drug used to treat respiratory infections and that its usage increased significantly since the beginning of the study. Resistance of Klebsiella pneumoniae to levofloxacin increased from 20% to 54% during the 5-year period. Based on these data, there is a greater likelihood of detecting which of the following in the latter isolates compared with the bacteria recovered at the beginning of the study?​

A. Expression of AmpC &#946;-lactamases
B. Expression of carbapenemase
C. Expression of extended-spectrum &#946;-lactamases
D. Mutation of the gene encoding dihydrofolate reductase
E. Mutation of the gene encoding elongation factor-2
F. Mutation of the gene encoding topoisomerase II

The graph shows the response elicited by different concentrations of drug X in a system containing spare receptors in the absence (solid curve) and presence (dashed curves) of two different concentrations of drug Y. Drug Y alone has no effect.
​

Which of the following best describes drug Y?
A. Competitive reversible antagonist
B. Full agonist
C. Inverse agonist
D. Noncompetitive antagonist
E. Partial agonist

A 42-year-old woman comes for a routine follow-up examination. She has an 8-year history of hypertension treated with a thiazide diuretic. She reports that she tires easily with exertion because of her weight but is otherwise asymptomatic. She drinks one to two glasses of wine weekly. There is no family history of liver disease. She is 163 cm (5 ft 4 in) tall and weighs 77 kg (170 lb); BMI is 29 kg/m2. Her blood pressure is 140/90 mm Hg. Examination shows no other abnormalities except for truncal obesity with no abdominal striae. Serum studies show:​

Urea nitrogen: 19 mg/dL
Glucose: 117 mg/dL
Creatinine: 1 mg/dL
Total cholesterol: 227 mg/dL
HDL-cholesterol: 32 mg/dL
Triglycerides: 347 mg/dL
AST: 87 U/L
ALT: 85 U/L
Which of the following is the most likely cause of this patient's increased serum liver enzyme activity?
A. Alcoholic hepatitis
B. Hemochromatosis
C. Hepatitis A
D. Nonalcoholic steatohepatitis
E. Porphyria cutanea tarda

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[rashy]

The answer indicated by the filled-in circle is mine, which is wrong. Please give explanations for the right answers, if possible. Thank You...

A 76-year-old woman comes to the physician because of severe back pain for the past 2 weeks. She has no history of smoking. She has been taking prednisone (30 mg/day) for rheumatoid arthritis for the past 6 months and has received hormone replacement therapy with estrogen and progesterone for the past 15 years. Calcium and vitamin D intake are adequate. X-rays of the spine show a vertebral fracture. Which of the following is the most likely cause of the fracture?​

A. Decreased bone formation due to decreased calcium absorption
B. Decreased bone formation due to inhibition of osteoblast differentiation -> Effect of the corticosteroids?
C. Increased bone resorption due to decreased calcium absorption
D. Increased bone resorption due to decreased serum parathyroid hormone concentration
E. Increased bone resorption due to estrogen receptor defect

A 49-year-old woman comes to the emergency department because of a 3-day history of fever, shortness of breath, and confusion. She is a postal worker. Her temperature is 38.4°C (101.2°F), respirations are 28/min, and blood pressure is 100/60 mm Hg. Physical examination shows nuchal rigidity. Breath sounds are decreased on the right side of the chest. A lumbar puncture is done. Analysis of cerebrospinal fluid (CSF) shows:​

Glucose: 18 mg/dL
Total protein: 138 mg/dL
Leukocyte count: 638/mm3
Segmented neutrophils: 87%
Monocytes: 13%
RBC: 2300/mm3

A Gram stain of CSF shows large, gram-positive, spore-forming bacilli. A chest x-ray shows marked widening of the mediastinum. Which of the following extracellular virulence factors most likely enables the causal organism to evade phagocytosis?​

A. Alginate
B. Glucuronoxylomannan
C. Hyaluronic acid
D. Polyglutamic acid -> Unique of B. anthracis. (+gram-positive, spore-forming bacilli and widening mediastinum gives you the definite diagnosis)
E. Polyribitol phosphate


A 37-year-old man comes to the emergency department because of a 10-day history of yellow skin, vague abdominal discomfort, and fatigue. His vital signs are within normal limits. Physical examination shows generalized icterus. Serum studies show:[/LEFT]
AST: 320 U/L
ALT: 340 U/L
Hepatitis B surface antigen(HBsAg): positiveIgM
anti-hepatitis B core antigen(HBcAg): positive
Anti-hepatitis D virus: negative

Direct damage to infected hepatocytes in this patient is most likely mediated predominantly by which of the following?​

A. Antibody against HBcAg
B. Antibody against HBsAg
C. Complement via the alternate pathway
D. Cytotoxic T lymphocytes -> pathogenesis of HVB -> Immunesystems kills our cells..
E. Viral cytopathic effect

A 6-year-old girl is brought to the physician by her mother because of a 2-week history of increased thirst and a 3-kg (6.6-lb) weight loss. Her mother says that the patient is constantly drinking water. She is at the 75th percentile for height and 50th percentile for weight. Physical examination shows tachypnea and dehydration. Laboratory studies show hyperglycemia, metabolic acidosis, and ketonemia. If a biopsy specimen were obtained from this patient's pancreas, which of the following findings in islet cells would now be most likely?​

A. Basement membrane thickening of capillaries
B. Cellular necrosis and lymphocytic infiltration -> Diabetes type 1
C. Decrease in mass and deposition of amyloid
D. Large &#946; cells and nuclei
E. Marked atrophy and fibrosis

Two programs for the treatment of patients with newly detected hypercholesterolemia were tried in a community. Program A was used in one district of the community, and Program B was used in another. After four years, 45% of the 2200 patients on Program A and 49% of the 1900 patients on Program B had been successfully treated for hypercholesterolemia. The difference between the success rates for the two programs was statistically significant (p < .01). Health officials, however, decided not to change to Program B in the first district because the magnitude of the difference was so small. Which of the following best explains their decision?​

A. They attributed the difference in success rates to chance alone
B. They distinguished between statistical significance and practical importance of the difference in success rates -> Just makes sense.. Something can be statistically significant, but it doesn't mean that it has to be CLINICALLY significant as well..
C. They felt the p value was too small to justify a decision in favor of Program B
D. They felt the samples were too small to justify a decision in favor of Program B

During a 5-year study at a hospital, data about antimicrobial drug use for respiratory infections and antimicrobial susceptibility for respiratory isolates are compiled. At the end of 5 years, the data show that levofloxacin was the most common drug used to treat respiratory infections and that its usage increased significantly since the beginning of the study. Resistance of Klebsiella pneumoniae to levofloxacin increased from 20% to 54% during the 5-year period. Based on these data, there is a greater likelihood of detecting which of the following in the latter isolates compared with the bacteria recovered at the beginning of the study?​

A. Expression of AmpC &#946;-lactamases
B. Expression of carbapenemase
C. Expression of extended-spectrum &#946;-lactamases
D. Mutation of the gene encoding dihydrofolate reductase
E. Mutation of the gene encoding elongation factor-2
F. Mutation of the gene encoding topoisomerase II -> Because Levofloxacin is a fluoroquinolone.

​

 

[jfgavina]

did this sucker yesterday, found it pretty exhausting but in the end it was not so hard. It's all in FA folks, you just need to interpret what they're asking! we shall not panic

 

[highscore]

The answer indicated by the filled-in circle is mine, which is wrong. Please give explanations for the right answers, if possible. Thank You...

A 76-year-old woman comes to the physician because of severe back pain for the past 2 weeks. She has no history of smoking. She has been taking prednisone (30 mg/day) for rheumatoid arthritis for the past 6 months and has received hormone replacement therapy with estrogen and progesterone for the past 15 years. Calcium and vitamin D intake are adequate. X-rays of the spine show a vertebral fracture. Which of the following is the most likely cause of the fracture?​

A. Decreased bone formation due to decreased calcium absorption
B. Decreased bone formation due to inhibition of osteoblast differentiation -> Effect of the corticosteroids?
C. Increased bone resorption due to decreased calcium absorption
D. Increased bone resorption due to decreased serum parathyroid hormone concentration
E. Increased bone resorption due to estrogen receptor defect

Thanks Rashy for your response. For this above question, I do understand that corticosteroids decrease bone mass. So, could it be C?
​

 

[rashy]

Whups, my mistake. I meant answer C. What I found on this though is: "Corticosteroids impair the action of vitamin D on intestinal calcium absorption and increase renal loss of calcium. Both effects lower the ambient serum calcium level and trigger a secondary hyperparathyroid state that might increase bone resorption. However, this is a subject of controversy and data are lacking." But it's probably still Answer C...
Also, take a look at this graph: http://www.musculoskeletalnetwork.com/image/image_gallery?img_id=1628797&t=1280510799517

 

[jfgavina]

what's the right answer after all? in FA it says that it is due to decreased bone formation. I think its due to cellular induction of apoptosis and decreased blastogenesis, thus answer B!

 

[tootheye]

Chr corticosterid therapy--->Osteoporosis
Mech: 1. Decreased absorption of Vit D----> Increased Urinary loss of Calcium
2. Decreased bone mass due to reduced collagen synthesis by o.blasts
3. Decreased GnRH
both 1 & 2 seem to fit here but 1 seems a better answer ( differentiation by o.blasts?) !
&#12288;
HBV - Hepatocye association
2 phases- 1.Proliferation phase- CD8-Tcells destroy hepatocytes--> injury
2.Integration phase- Viral DNA integrated into genome of survived hepatocytes--> Hepatocellular ca

Dose response curves-
Its a non competetive antagonist
- shift to right= Antagonist, ? <ED 50= Non competetive

Just read a few yesterday- from my annotated notes.

 

[jfgavina]

according to FA is due to decreased bone formation, just see the endocrine chapter. it doesn't mean that the other choices are incorrect, because glucocorticoids also decrease calcium absorption via inhibition of vit D but the question asks "most likely" so you've got to pick the main reason which is inhibition of osteoblasts. FA is the bible, so if it says that is due to decreased bone formation I believe in it and do my best in trying to apply those concepts in the actual test, so if it is listed there that its due to decreased bone formation I think about what forms bones, which are osteoblasts, so the only option I could see was option B when I was doing my nbme11 yesterday! I figured out how they ask questions, it's a multi-step thinking folks! don't disagree with NBME and FA LOL

 

[jfgavina]

http://www.endocrine-abstracts.org/ea/0020/ea0020s10.2.htm and btw read this

 

[norealname]

Hey jfgav, I got all these questions right on my NBME11 (didn't get them wrong in my extended feedback). Here are the answers I've chosen. Let me know if you need an explanation for any of the answers.

B. Decreased bone formation due to inhibition of osteoblast differentiation

D. Polyglutamic acid

E. Selegiline

D. Cytotoxic T-lymphocytes

B. Cellular necrosis and lymphocytic infiltration

B. They distinguished between statistical significance and practical importance of the difference in success rates.

F. Mutation of gene encoding topoisomerase II

D. Noncompetitive antagonist

D. Nonalcoholic steatohepatitis

 

[jfgavina]

thanks no real! I was actually supporting the theory that corticosteroids inhibit osteoblast diff because I've choosen that one on the actual test and it didn't appear in my expanded feedback..

just for curiosity, how many questions you got wrong and what was your score?

 

[norealname]

You're welcome man. I had 8 wrong questions, which was equivalent to 266.

 

[jfgavina]

do you have your results in hand?

 

[norealname]

You mean my USMLE results? I just wrote mine last week. It should be out in the next 2 weeks I'm hoping.

 

[ctizzle13498]

Hey jfgav, I got all these questions right on my NBME11 (didn't get them wrong in my extended feedback). Here are the answers I've chosen. Let me know if you need an explanation for any of the answers.

B. Decreased bone formation due to inhibition of osteoblast differentiation

D. Polyglutamic acid

E. Selegiline

D. Cytotoxic T-lymphocytes

B. Cellular necrosis and lymphocytic infiltration

B. They distinguished between statistical significance and practical importance of the difference in success rates.

F. Mutation of gene encoding topoisomerase II

D. Noncompetitive antagonist

D. Nonalcoholic steatohepatitis

can u explain this please

 

[norealname]

Hey ctizzle,
That question is actually somewhat easy if you read the question slowly. You don't even need to know how corticosteroids affect different body functions. If you read the question, you will find that the patient is following practices that should actually maintain her bone mass, except for one thing which is the use of corticosteroids. I'll list the other options in the question and tell you why you should eliminate all of them. This is how I got to the right answer as well.

A. Decreased bone formation due to decreased calcium absorption
-This answer is wrong simply because the patient is taking both calcium and vitamin D supplements, which should maintain her calcium absorption in a healthy state, and bone formation should therefore be normal

C. Increased bone resorption due to decreased calcium absorption
-Again, same as above, her calcium absorption is fine. It's the corticosteroids that are to blame.

D. Increased bone resorption due to decreased serum parathyroid hormone concentration
-There is no reason for having elevated PTH in this patient. She is not at risk of hypocalcemia to have her PTH elevated

E. Increased bone resorption due to estrogen receptor defect
-Something like an estrogen receptor defect should have manifested way earlier in her life, not when she's in her mid 70's.

So you don't really need to know what glucocorticoids do in order to cause osteoporosis. However, just in case you need something extra, NEJM had an article quite recently actually about this. The article is Glucocorticoid-Induced Bone Disease, by Robert S. Weinstein, M.D. The article mentions that corticosteroids reduce differentiation of osteoblasts while prolonging the life of existing osteoclasts, which reduces bone deposition, leading to secondary osteoporosis and all its complications.

 

[highscore]

Thanx guyz for all your responses. The explanations really help.

 

[brokemedstudent]

The answer indicated by the filled-in circle is mine, which is wrong. Please give explanations for the right answers, if possible. Thank You...

A 76-year-old woman comes to the physician because of severe back pain for the past 2 weeks. She has no history of smoking. She has been taking prednisone (30 mg/day) for rheumatoid arthritis for the past 6 months and has received hormone replacement therapy with estrogen and progesterone for the past 15 years. Calcium and vitamin D intake are adequate. X-rays of the spine show a vertebral fracture. Which of the following is the most likely cause of the fracture?​

A. Decreased bone formation due to decreased calcium absorption
B. Decreased bone formation due to inhibition of osteoblast differentiation
C. Increased bone resorption due to decreased calcium absorption
D. Increased bone resorption due to decreased serum parathyroid hormone concentration
E. Increased bone resorption due to estrogen receptor defect

A 49-year-old woman comes to the emergency department because of a 3-day history of fever, shortness of breath, and confusion. She is a postal worker. Her temperature is 38.4°C (101.2°F), respirations are 28/min, and blood pressure is 100/60 mm Hg. Physical examination shows nuchal rigidity. Breath sounds are decreased on the right side of the chest. A lumbar puncture is done. Analysis of cerebrospinal fluid (CSF) shows:​

Glucose: 18 mg/dL
Total protein: 138 mg/dL
Leukocyte count: 638/mm3
Segmented neutrophils: 87%
Monocytes: 13%
RBC: 2300/mm3

A Gram stain of CSF shows large, gram-positive, spore-forming bacilli. A chest x-ray shows marked widening of the mediastinum. Which of the following extracellular virulence factors most likely enables the causal organism to evade phagocytosis?​

A. Alginate
B. Glucuronoxylomannan
C. Hyaluronic acid
D. Polyglutamic acid
E. Polyribitol phosphate

A 45-year-old man with recently diagnosed early-onset Parkinson disease comes to the physician for a follow-up examination. He has a long history of major depressive disorder successfully treated with fluoxetine. Treatment with which of the following antiparkinsonian drugs is contraindicated in this patient?​

A. Amantadine
B. Benztropine
C. Levodopa
D. Ropinirole
E. Selegiline

A 37-year-old man comes to the emergency department because of a 10-day history of yellow skin, vague abdominal discomfort, and fatigue. His vital signs are within normal limits. Physical examination shows generalized icterus. Serum studies show:​

AST: 320 U/L
ALT: 340 U/L
Hepatitis B surface antigen(HBsAg): positiveIgM
anti-hepatitis B core antigen(HBcAg): positive
Anti-hepatitis D virus: negative

Direct damage to infected hepatocytes in this patient is most likely mediated predominantly by which of the following?​

A. Antibody against HBcAg
B. Antibody against HBsAg
C. Complement via the alternate pathway
D. Cytotoxic T lymphocytes
E. Viral cytopathic effect

A 6-year-old girl is brought to the physician by her mother because of a 2-week history of increased thirst and a 3-kg (6.6-lb) weight loss. Her mother says that the patient is constantly drinking water. She is at the 75th percentile for height and 50th percentile for weight. Physical examination shows tachypnea and dehydration. Laboratory studies show hyperglycemia, metabolic acidosis, and ketonemia. If a biopsy specimen were obtained from this patient's pancreas, which of the following findings in islet cells would now be most likely?​

A. Basement membrane thickening of capillaries
B. Cellular necrosis and lymphocytic infiltration
C. Decrease in mass and deposition of amyloid
D. Large &#946; cells and nuclei
E. Marked atrophy and fibrosis

Two programs for the treatment of patients with newly detected hypercholesterolemia were tried in a community. Program A was used in one district of the community, and Program B was used in another. After four years, 45% of the 2200 patients on Program A and 49% of the 1900 patients on Program B had been successfully treated for hypercholesterolemia. The difference between the success rates for the two programs was statistically significant (p < .01). Health officials, however, decided not to change to Program B in the first district because the magnitude of the difference was so small. Which of the following best explains their decision?​

A. They attributed the difference in success rates to chance alone
B. They distinguished between statistical significance and practical importance of the difference in success rates
C. They felt the p value was too small to justify a decision in favor of Program B
D. They felt the samples were too small to justify a decision in favor of Program B

During a 5-year study at a hospital, data about antimicrobial drug use for respiratory infections and antimicrobial susceptibility for respiratory isolates are compiled. At the end of 5 years, the data show that levofloxacin was the most common drug used to treat respiratory infections and that its usage increased significantly since the beginning of the study. Resistance of Klebsiella pneumoniae to levofloxacin increased from 20% to 54% during the 5-year period. Based on these data, there is a greater likelihood of detecting which of the following in the latter isolates compared with the bacteria recovered at the beginning of the study?​

A. Expression of AmpC &#946;-lactamases
B. Expression of carbapenemase
C. Expression of extended-spectrum &#946;-lactamases
D. Mutation of the gene encoding dihydrofolate reductase
E. Mutation of the gene encoding elongation factor-2
F. Mutation of the gene encoding topoisomerase II

The graph shows the response elicited by different concentrations of drug X in a system containing spare receptors in the absence (solid curve) and presence (dashed curves) of two different concentrations of drug Y. Drug Y alone has no effect.
​

Which of the following best describes drug Y?
A. Competitive reversible antagonist
B. Full agonist
C. Inverse agonist
D. Noncompetitive antagonist
E. Partial agonist

A 42-year-old woman comes for a routine follow-up examination. She has an 8-year history of hypertension treated with a thiazide diuretic. She reports that she tires easily with exertion because of her weight but is otherwise asymptomatic. She drinks one to two glasses of wine weekly. There is no family history of liver disease. She is 163 cm (5 ft 4 in) tall and weighs 77 kg (170 lb); BMI is 29 kg/m2. Her blood pressure is 140/90 mm Hg. Examination shows no other abnormalities except for truncal obesity with no abdominal striae. Serum studies show:​

Urea nitrogen: 19 mg/dL
Glucose: 117 mg/dL
Creatinine: 1 mg/dL
Total cholesterol: 227 mg/dL
HDL-cholesterol: 32 mg/dL
Triglycerides: 347 mg/dL
AST: 87 U/L
ALT: 85 U/L
Which of the following is the most likely cause of this patient's increased serum liver enzyme activity?
A. Alcoholic hepatitis
B. Hemochromatosis
C. Hepatitis A
D. Nonalcoholic steatohepatitis
E. Porphyria cutanea tarda

After entering the blood, the virus infects hepatocytes and viral antigens are displayed on the surface of the cells. Cytotoxic T cells mediate an immune attack against the viral antigens, and inflammation and necrosis occur. Immune attack against viral antigens on infected hepatocytes is mediated by cytotoxic T cells. The pathogenesis of hepatitis B is probably the result of this cell-mediated immune injury because HBV itself does not cause a cytopathic effect.