need answers for NBME1 questions

[hiran]

hi took nbme1 yesterday and have a doubt with these questions.can someone please answer with explanations
1)A man developed hypertension and on examination was found to have rt sided renal artery occlusion.he was posted for surgery.which of the following is the best predictor that this surgery to remove occlusion will benefit him.Inrease in renin concentration in
a)rt.renal artery b)R.renal vein c)L.renal artery D)L renal vein
2.)A neonate has ambiguous genitalia. In the first 48 hours of life, the neonate feeds poorly and becomes dehydrated. Which of the following is the most likely diagnosis?

A) Androgen insensitivity syndrome

B) 5α-Reductase deficiency

C) 17-Hydroxylase deficiency

D) 21-Hydroxylase deficiency

E) True hermaphroditism
3)
A 55-year-old man has had patchy leukoplakia of the anterior floor of his mouth for 4 years. He now has a raised, firm white lesion in the same area. Examination of tissue obtained on biopsy of this new lesion is most likely to show

A) aphthous ulcer
B) Burkitt's lymphoma
C) Candida infection
D) Kaposi's sarcoma
E) mixed tumor of the parotid gland
F) squamous cell carcinoma
G) Warthin's tumor
4)A homeless 38-year-old man has a 3-month history of decreased appetite, generalized wasting, a low-grade fever, and worsening cough productive of bloody, mucopurulent sputum. He has a 3-year history of alcohol abuse. X-*** films of the chest show consolidation and cavitary lesions in the apices of the lungs. Which of the following is the most likely inflammatory and/or immune response in the lung?

A) Endothelial cell proliferation, vascular budding, fibroblasts

B) Epithelioid cells, multinucleated giant cells, caseation necrosis
C) Fibroblasts, collagen deposition, replacement of intrinsic tissue
D) Macrophages, lymphocytes, hypergammaglobulinemia

E) Neutrophils, vascular congestion, exudates

5)A 25-year-old woman has had generalized bone pain for 9 years. She has frequent episodes of loose bulky stools. Examination shows muscle weakness and a distended abdomen. X-*** films show generalized demineralization of bones, absence of the lamina dura, and fracture-like lines in the bones of the feet. Which of the following sets of findings in serum is most likely in this patient?

Calcium/Phosphorus/Alkaline phosphatase/Parathyroid hormone

A) ↓ ↓ ↑ ↑

B) ↓ ↑ ↑ ↓

C) ↓ ↑ ↑ ↑

D) ↑ ↓ ↓ ↓

E) ↑ ↓ ↓ ↑
6)A 4-year-old girl is brought to the emergency department because of a 5-day history of fever, diffuse abdominal pain, nausea, vomiting, and diarrhea. Examination shows petechiae, hepatomegaly, and splenomegaly. Hemoglobin concentration is 8.7 g/dL and platelet count is 60,000/mm3. A peripheral blood smear shows erythrocyte fragmentation. Which of the following renal findings is most likely to be associated with her condition?

A) Glomerular crescent formation
B) IgG-associated glomerular basement membrane antibody
C) Membranoproliferative glomerulonephritis
D) Narrowing of the capillary wall by fibrin deposition
E) Periglomerular granuloma with giant cells
7)A 72-year-old man comes to the physician because of an 8-month history of feeling light-headed when he stands up. Blood pressure is 130/85 mm Hg while supine and 94/64 mm Hg while standing. High-dose fludrocortisone therapy is started. After 5 days of treatment, laboratory studies are most likely to show which of the following changes?


Serum Urine
K+ Renin K+ excretion

A) ↓ ↑ ↑

B) ↓ ↑ ↓

C) ↓ ↓ ↑

D) ↑ ↑ ↓

E) ↑ ↓ ↑

F) ↑ ↓ ↓
8)A 42-year-old man with pneumococcal pneumonia has acute fibrinous pleuritis. Which of the following proteolytic enzymes is required to eliminate the exudate and restore normal pleural anatomy?

A) Collagenase

B) Plasmin

C) Stromeolysin

D) Thrombin

E) Trypsin
9)A 25-year-old woman, gravida 1, para 0, who is Rh-negative, delivers a full-term Rh-positive neonate. The mother is given prophylactic anti-Rho(D) immune globulin immediately post partum. During her second pregnancy 3 years later, she is screened each trimester for Rho(D) antibodies. An indirect antiglobulin test done during the third trimester indicates the presence of anti-Rho(D) antibodies in her serum. Which of the following is the most likely mechanism for the occurrence of these maternal antibodies?

A) Anamnestic production of maternal anti-Rho(D) immunoglobulin

B) Intrauterine transplacental fetal-maternal hemorrhages during the second pregnancy

C) Residual circulating prophylactic anti-Rho(D) immunoglobulin

D) Transplacental passage of fetal IgG anti-Rho(D) antibodies

10)A 35 yr old woman developed temp103F and susternal chest pain following treatment with gingivitis.chest xray showed enlarged cardiac silhoutte and a pericardial fluid of ml was drawn which was cloudy and full of neutrophils. what is the most likely organism
a) acid fast bacillib) gr positive cocci c) gr neg bacilli d) budding yeast formse) dna virus

11)over the past 6 months, a 54-year-old woman has had several episodes of nervousness in which her heart pounds and her skin becomes clammy. She has also had difficulty sleeping and recently developed hypertension. The most likely cause is a neoplasm in which structure labeled on the cross-sectional drawing of the abdomen at the level of T-12 to L-1?

A) B) C) D) E) F) G) H) I)



12)An 85-year-old woman who was admitted to the hospital 3 days ago for myocardial infarction has a radionuclide scan that shows damage to the anterior wall of the left ventricle. Which of the following coronary vascular structures was most likely occluded?

A) Circumflex artery
B) Coronary sinus
C) Left anterior descending artery
D) Posterior descending artery
E) Right coronary artery
F) Right marginal artery

[jachica]

Hi ~
I believe the answer to number 12 is left anterior descending artery. It is the most common artery to be occluded which then causes infarction of the anterior wall of the left ventricle.
hope this helps!

Isn't #4 a case of TB? So B should be the answer I think

[guodon]

1) L. Renal Vein ( renin will increase in left renal vein since the feed-back mechanism is gone, its renin level was very low before the surgery.)

[guodon]

2) answer is D) 21-Hydroxylase deficiency.

The neonate is female pseudohermaphrodite. The key is dehydrated, which means aldosterone level decreased! others don't change aldosterone level.

[guodon]

3) answer is squamous cell carcinoma (F).

The man has leukoplakia that results from hyperkeratosis secondary to chronic irritatation. The lesion may represent dysplasis or carcinoma.

[guodon]

4) case is TB, answer is B.
The man had 3-month history of decreased appetite, generalized wasting, a low-grade fever. These are typical symptoms of TB.

[guodon]

5) amswer is A.

This woman has frequent episodes of loose bulky stools, which means Vitamin D deficiency. Calcium and Phosphorus absorb will be decreased. Both serum calcium and Phosphorus level will decrease. In resopnse to the low level serum calcium, PTH will be increased, osteoclastic and alkaline phosphate will be increased too.

[guodon]

6) the answer is D:Narrowing of the capillary wall by fibrin deposition

The little girl had Thrombotic thrombocytopenic purpura (TTP). TTP can result in renal insufficiency by deposit fibrin in the renal capillary.

[guodon]

7) the answer is C) ↓↓↑

The man has orthostatic hypotension. fludrocortisone will cause body Na+ and water retention and therefore increase blood pressure, serum renin will decrease. Cortisone also increase K+ and H+ excretion and cause hypokalemic alkalosis.