Please help me with the answer fof these Questions. this is the First NBME exam I took & scored 410/200. I am freaked out ... I have few more but this is what i can type after a looong day ..here they are.. I really appreciate your time in advance.

1- A 32-years old Woman receives a dose of warfarin orally for a large deep venous thrombus of the right led. She is currently taking an oral contraceptive. Her prothrombin time is 12 sec(INR 1.0). Two hours after administration of the warfarin, her prothrombin time remains 12 sec(INR 1.0). Which of the following best explains why this patient’s prothrombin time did not change?
A. The large thrombus increases the dose of warfarin required.
B. Oral contraceptives accelerate the clearance of warfarin.
C. Preexisting circulating coagulation factors have not been cleared.
D. Prothrombin times is not a measure of the efficacy of warfarin.
E. Warfarin should have been administered intravenously.

2- During Development, a neural precursors migrate from yjr bowel into organs that develop from the primordial gut. As a result, which of the following organs is most likely to contain ganglia innervated enteric neurons?
A. Adrenal Gland
B. Kidney
C. Pancreas
D. Spleen
E. Ureter

3-A case control study is performed to determine the association between brain tumors and cell phone use. The results show an odds ratio of4.3(95% confidence interval: 0.9-8.2) for an association between brain tumors and cell phone use. Assume that 99% confidence interval was computed rather than 95% confidence interval. Which of the following statement best describes the size of the 99% confidence interval compared to the 95% confidence interval?
A. Larger
B. Smaller
C. The same
D. Can not be determined from the information given.

4- A 22- years old woman participates in a clinical study of putative protein hormone that is synthesized in the liver in response to the decrease in the blood platelet concentration. Injection of the hormone causes an increase in platelet production. Which of the following is the most likely location of the receptor that accounts for the increase in platelet count?
A. In the cytoplasm of hepatocytes.
B. In the cytoplasm of megakaryocytes
C. In the nucleus of hepatocytes
D. In the nucleus of megakaryocytes
E. On the cell membrane of hepatocytes

5-A study is done to determine the efficacy of fish oil in preventing progression of renal disease in patients with lgA nephropathy. 100 consecutive patients with newly diagnosed lgA nephropathy are entered into the study. The odd numbered patients are treated with fish oil and the even numbered patients are treated with olive oil, an inactive fatty acid. Over the next 5 years, all patients are followed for the development of end-stage renal disease. Results are shown:
. #reaching end Stage Renal Disease
Fish oil Group (n=50) 3
Olive oil Group (n=50) 17

The incidence of end stage renal disease in the fish oil group was significantly lower than in the Olive oil group (p<0.01). which of the following best describes the Study?
A. Case- Control
B. Case Series
C. Cohort
D. Controlled Trial
E. Crossover
F. Cross-Section

1. C. Factor 2,7,9,10 have half lives of 6-80 hrs ,so the anticogulant effect will only be observed after the preformed factors are eliminated.
2. C. Pancreas .It contains ganglia of enteric neurons (I hope I have got the question right!)
3. A. Larger ,because 99% CI is always wider than 95% CI.
4. B. cytoplasm of megakaryocytes, the hormone is Thrombopoeitin (TPO) synthesized by the liver cells to stimulate maturation of megakaryocytes into platelets.
5. C. cohort (incidence study).

I think 5. should be A because cases got fish oil and controls got olive oil

I think 5. should be A because cases got fish oil and controls got olive oil[/quote]

But case control study is Retrospective...u see what happened?
and in cohort u see what will happen?

THANK YOU so much Wiwi... I have got some more below.. i think this is a great way for all of you guys to participate in answering these questions. everyoen will benefit. here are some more, Please tell me what arte your thoughts:

6-An investigator is evaluating the outcome of the coronary artery bypass grafting conducted by two surgeons in the community in the past year. Surgeon X, who operates exclusively at a tertiary-care facility, has 30 day operative mortality of 3%. Surgeon Y, who operates exclusively at a community care facility, has a 30 day operative mortality of 1%. The difference in operative mortality between surgeon X and Y is significant(p<0.05). the invistigator conclude that patients should have care at the community care facility. Which of the following raises the most concern regarding the validity of the conclusion?
A. Lack of control of case complexity
B. Lack of control of patient cholesterol data
C. Lack of control of patient follow up.
D. Lack of control of patient recuperation
E. Unequal sample size between surgeons

7-A 50 year old man comes to the physician because of fever, muscle pain, sore throat and nonproductive cough for 7 days. He has had two episodes of similar symptoms during the past year. He has smoked 2 paks of cigaretts daily for 30 years. His temperature is 38.9C (102F). rhonchi and crackles are heard on auscultation of the chest. Chest x-ray shows consolidation f=of the right lower lobe. Which of the followingmechanisms if the most likely cause of these clinical finding?
A. Inactivation of muramyl dipeptide
B. Induction of acidification of endosomes in alveolar macrophages
C. Injury to the mucociliary escalator
D. Stimulation of lgM to lgA switching
E. Suppression of cough reflex
8- A 35 year old man has the sudden onset of headaches and partial loss of vision. He has history of rheumatic heart disease and atrial fibrillation. He has left homonymous hemianopia with partial macular sparing. The most likely explanation for these finding is occlusion of which of the following arteries?
A. Lenticulostriate
B. Middle Cerebral
C. Posterior cerebral
D. Thalamoperforate
E. Vertebral

9- A Married 78 year old man is brought to the ER after ingesting ten 15-mg temazepam tablets. After he is stabilized medically, he undergoes psychiatric evaluation. Which of the following is most important in assessing his risk of suicide?
A. Early morning awakening with decreased appetite.
B. Family history of suicide
C. Male gender
D. Marital status
E. Patient’s belief that temazepam would kill him


10-In nucleotides, the sugars are attached ti the nitrogen- containing bases by which of the following?
A. Electrostatic Interactions
B. Hydrogen bonds
C. N-glycosidic bonds
D. Phosphodiester Bonds.
E. Stacking interactions

These are the answers which Im sure about:

8. C. Post cerebral artery,left homonymous hemianopia with macular sparing is the clue.(I have never heard of PARTIAL macular sparing and I think they mean the same because its hemianopia so only half of the visual field is lost and half of the macula is spared)
9. C. Male Gender ( among all the risk factors,this is number1)
10. C. N glycosidic bond (sugar to nitrogen)

And now the answers which Im guessing:

6.A. Lack of control of case complexity(pt cholestrol data is very speicifc thing and if it was related to CABG or the mortality,I think this should have been the topic of research ;since the patients are dying so there is no need for follow up or recuperation;and they havent told us the numbr of ppl,only percentages are given so unequal sample size doesnt seem to me an issue)
7.C. Injury to mucociliary escalator...this is the only thing that is going well with 60 pack yrs of smoking...though Im very doubtful about his diagnosis I mean fever, muscle pain with unproductive cough is going with viral or may be chronic bronchitis but then lobar pneumonia?!
*Inactivation of muramyl dipeptide...its a penicillin
*Induction of acidification of endosomes in alveolar macrophages...its to kill to the organism,not to cause the symptoms
*Suppression of cough reflex...he wouldnt be coughing at all then,and I never heard of cough suppresssion in a smoker.
*Stimulation of lgM to lgA switching....this shud be the protective mechanism not the cause of symptoms!

Correct me where Im wrong...and GL!
*

[quote=wiwi18024815]I think 5. should be A because cases got fish oil and controls got olive oil[/quote]

But case control study is Retrospective...u see what happened?
and in cohort u see what will happen?[/quote]

Case control studies look for a difference between cases and control groups. They can be both retro and prospective
edited by aquresh1 on 5/15/2011

Ok. Here's my take on this:
6. Patients presenting at tertiary care centers are generally more complicated so I agree with A. The explanation is just that. They are more complicated and more likely to die anyway.
7. Poor mucociliary elevator function does occur in smokers and is responsible for development of lung infection in this population.
8. C
9. A. This man could be severely depressed which could cause suicidal ideation; he is not divorced or a widower--that risk of suicide increases among elderly males who have lost their wives and are suffering from loneliness. Women cope better!
10. C.

Case control studies look for a difference between cases and control groups. They can be both retro and prospective
edited by aquresh1 on 5/15/2011[/quote]

thanxs for correcting me,ur right case control can be both retrospective and prospective, but right now im using kaplan behavioral notes and it says that u cant assess incidence or prevalance in case control,whereas in cohort outcome is disease incidnce...Im a little confused now...can u please elaborate or give a proper reference for that?

@aquresh1

well behavioral questions are always tricky to pick and its always better to discuss rather than keeping it to urself...so here it is about question 9.

I was actually thinking about the numbers:
"Suicide was the seventh leading cause of death for males and the fifteenth leading cause of death for females in 2007.
Almost four times as many males as females die by suicide."
This is what they say on National Institute of Mental Health website.
so i agree what ur saying but the option 'Male' in the list is again doubtful for me.

Thanks aquresh1 & Wiwi, you guys are a great help. I really appreciate it.

here are some more for the best of everyone:


1- A 31 years old man with AIDS is receiving highly active antiretroviral Therapy(HAART). Lab Study shows significant myelosuppression and a decreased plasma HIV-mRNA Burden. To counteract this toxicity (rather than modify his antiretroviral therapy), he begins treatment with a hematopoietic growth factor. Thirty minutes later, he develops dyspnen, severe muscle pain, vomiting and sinus tachycardia, his blood preasure is 80/40 mm HG. Which of the following hematopoietic growth factors most likely caused these new findings?
A. Erythropoietin
B. Filgrastim(G-CSF)
C. Platelet-derived growth factor
D. Sargramostim(GM-CSF)
E. Thrombopoietin

2- A 55 years old woman comes to the Dr. because of 3 month history of Chronic back pain & Difficalty walking. Neurologic examination shows tenderness of the spine and footdrop. As the lumber disc herniates into the spinal canal, which of the following ligaments is pushed into the spinal root nerves?
A. Anterior longitudinal ligament
B. Cruciform ligament
C. Interspinous ligament
D. Ligamentum flavum
E. Posterior longitudinal ligament
F. Supraspinous ligament


3- The table shows survival of patients who had an operation for a particular form of cancer:

# of Patients # of patients who % of patients
at the beginning died during the surviving
Interval of the interval interval this interval
0-1 year 300 115 62
1-2 years 185 37 80
2-3 years 148 24 84
3-4 years 124 18 85
4-5 years 106 25 76

If a patient survives 2 years after the operation, which of the following is probability of surviving at least 4 years?

A) 0.8
B) 0.85
C) .84 X .85
D) .62 X .80 X .84 X .85
E) .85 -.80

4- in a 24 years old woman, which of the following is most likely to induce a shift in the normal balance of bone accretion and resorption toward net bone loss?
A. Bodybuilding and use of anabolic steroids.
B. Eating a high calcium diet
C. Living on a space stationfor the past 6 months
D. Metabolic alkalosis and chronic vomiting
E. Running1 to 2 miles, 3 times weekly



5-
# of Childdren tract infections # of urinary
25 0
30 1
10 2
35 3


Which of the following is the median # of episodes of UTI for Children (n=100) in the sample shown above?

A) 0
B) 1
C) 2
D) 3
E) Cannot be determined from the Data

May be wrong here, but I think This is a Controlled Trial. This is comparing a treatment(fish oil)to a placebo(control:mentions inactive FA). Or even if it isn't a placebo, it's still comparing two potential treatments. A Cohort which would be the other possibility would be assessing Risk factor.

I didn't see if anyone else said this above, so apologies if this opinion was already explained.

[quote=wiwi18024815]Case control studies look for a difference between cases and control groups. They can be both retro and prospective
edited by aquresh1 on 5/15/2011[/quote]

thanxs for correcting me,ur right case control can be both retrospective and prospective, but right now im using kaplan behavioral notes and it says that u cant assess incidence or prevalance in case control,whereas in cohort outcome is disease incidnce...Im a little confused now...can u please elaborate or give a proper reference for that?[/quote]

Look for the post by mkirkwood . he explained it better.

[quote=wiwi18024815]I think 5. should be A because cases got fish oil and controls got olive oil[/quote]

But case control study is Retrospective...u see what happened?
and in cohort u see what will happen?[/quote]

Agree as well.

In case control, you start with disease and see what happens based on exposure, i.e., Do persons with Crohn's Disease who eat a vegetarian diet have fewer exacerbations each week vs meat eaters?

In cohort, start with exposure and see if disease happened/happens, i.e, are persons who eat a vegetarian diet less likely to have/get Crohn's Disease?

In a controlled trial, the controlling part refers to the study design and trial refers to the intervention. Using the example above, if you believe that eating a vegetarian diet will reduce the symptoms of Crohn's, this hypothesis could be tested using a controlled trial. Persons participating would chosen in some manner to receive intervention (veggie diet) or control (meat diet) then those persons symptoms could be tracked to see if the intervention worked (compare the outcomes of the groups).

Hope that helps.

You're right. These questions are tricky. First of all, he is an elderly man who is probably getting treated for insomnia or even some other chronic pain/physical illness. Secondly, he overdosed on a prescription medication so is he trying to commit suicide? Is it possible that he can't cope any longer with what he has? Finally, what should the physician be concerned about? If you look at it this way, male gender is a better option than symptoms of depression. On the other hand, Temazepam is contraindicated in patients with depression and suicidal tendencies...and if this patient has demonstrated suicidal ideation should we now determine what was his risk factor for this? Sounds like...would u like to shoot yourself? Take my gun.... lol
edited by aquresh1 on 5/16/2011
edited by aquresh1 on 5/16/2011

[quote=mkirkwood][quote=Drmnicola]


May be wrong here, but I think This is a Controlled Trial. This is comparing a treatment(fish oil)to a placebo(control:mentions inactive FA). Or even if it isn't a placebo, it's still comparing two potential treatments. A Cohort which would be the other possibility would be assessing Risk factor.

I didn't see if anyone else said this above, so apologies if this opinion was already explained.[/quote]

No this was not explained before ,and actually it makes sense,i was so used to using the word RCT that i dint actually pay attention to Controlled trials... and yes they are properly randomized and ur point about comparing the treatment is absolutely right, RCT is commonly used for that.

4- A 22- years old woman participates in a clinical study of putative protein hormone that is synthesized in the liver in response to the decrease in the blood platelet concentration. Injection of the hormone causes an increase in platelet production. Which of the following is the most likely location of the receptor that accounts for the increase in platelet count?
A. In the cytoplasm of hepatocytes.
B. In the cytoplasm of megakaryocytes
C. In the nucleus of hepatocytes
D. In the nucleus of megakaryocytes
E. On the cell membrane of hepatocytes



answer 4 there is another option which is missing in the question that is cell membrane of megakaryocytes there is a cmpl receptor so thrombopoeitin binds to these receptors present on cell membrane not inside the cytoplasm

Thank you. I believe that is correct.

Answers:
1. D
2. A
3. D
4. C
5. C

Yes you guys are right, I was a little confused too in picking the answer but actually TPO binds to the outside of the membrane receptor Mpl but its the cytoplasmic domain which works through JAK-STAT pathway!
Hope that helps!

2- A 55 years old woman comes to the Dr. because of 3 month history of Chronic back pain & Difficalty walking. Neurologic examination shows tenderness of the spine and footdrop. As the lumber disc herniates into the spinal canal, which of the following ligaments is pushed into the spinal root nerves?
A. Anterior longitudinal ligament
B. Cruciform ligament
C. Interspinous ligament
D. Ligamentum flavum
E. Posterior longitudinal ligament
F. Supraspinous ligament


I think the answer is E
spinal cord lies post to the vertebral bodies.
herniation of nucleus pulposus is almost always in posterolat direction.

1. A(its myelosuppresion so GM-CSF is a better option,G-CSF only increases neutrophils and both have same side effects)
2. D/E( cos anterior ligament is in front of the spine not in front of the spinal cord,and post ligament is doubtful for me cos it acually prevents the herniation and causes the hernaition to be postero lateral rather than posterior.)
3. D
4. c (effect of gravity is lost)
5. c (this seems to me pretty sraight forward but zero is making it a little doubtful)

and I would appreciate if some one explains the method of Q 3 again for me,I want to make sure Im not going wrong. Thanx in advance!

[quote=wiwi18024815][quote=aquresh1][quote=Drmnicola]here are some more for the best of everyone:




3- The table shows survival of patients who had an operation for a particular form of cancer:

# of Patients # of patients who % of patients
at the beginning died during the surviving
Interval of the interval interval this interval
0-1 year 300 115 62
1-2 years 185 37 80
2-3 years 148 24 84
3-4 years 124 18 85
4-5 years 106 25 76

If a patient survives 2 years after the operation, which of the following is probability of surviving at least 4 years?

A) 0.8
B) 0.85
C) .84 X .85
D) .62 X .80 X .84 X .85
E) .85 -.80



1. A(its myelosuppresion so GM-CSF is a better option,G-CSF only increases neutrophils and both have same side effects)
2. D/E( cos anterior ligament is in front of the spine not in front of the spinal cord,and post ligament is doubtful for me cos it acually prevents the herniation and causes the hernaition to be postero lateral rather than posterior.)
3. D
4. c (effect of gravity is lost)
5. c (this seems to me pretty sraight forward but zero is making it a little doubtful)

and I would appreciate if some one explains the method of Q 3 again for me,I want to make sure Im not going wrong. Thanx in advance![/quote]

Explanation:
Actually I apologize for the typo...the answer is C. NOT D.
If the patient has survived 2 years then he has to survive the 3rd before he can survive the fourth. So you multiply the probability of the 3rd year and the probability of the 4th to get the correct answer.

Remember that a number multiplied by zero is zero. So 25 * 0= 0

The first question was about toxicity of the drug. D. should be correct b/c these symptoms happen with the first dose of Sarg.[GM_CSF]...

Also about anatomy, I haven't read it. I'm thinking that the question is asking which ligament compresses spinal nerve roots. If the disc is herniating posterolaterally, then which lig. will push into that "empty" space? It should be something anterior, no?
edited by aquresh1 on 5/17/2011
edited by aquresh1 on 5/17/2011

@aquresh1

Thanx for explaining Q 3 again.

And i wrote A instead of D by mistake ...and filgastrim and sargramostim both have almost same side effects ,i figured it out cos in myelosuppression, u'll lose all of the cell lineages so GM-CSF would work better...and also there is a line in First Aid about it too probably in HIV section.

If you look at spinal cord ligaments in Netter's (or any other atlas that ur using) u'll clearly understand this issue.