NBME 1 Block 1

1-b

      His prolonged productive cough, hemoptysis, weight loss, and cavitary lesions on CXR is consistent with pulmonary tuberculosis

2-c

     He has signs of possible abuse on physical exam.

     I know in the ER they typically do C. and it sounds best. You wouldn’t want to confront the patient’s family because you don’t know for sure.  You wouldn’t just remove him because you don’t know who is actually abusing him or if he even is. Social services could look into it and something can be done without jumping to conclusions and blaming people

3-b

       Sudden death due to pulmonary embolism. DVT from being bedridden was source of emboli.

       Being bedridden puts her at risk for DVTs.  Cancer in general can create a procoagulable state. With two risk factors for DVT it seems like the most likely diagnosis.  Additionally it correlates well with the clinical scenario of a sudden onset of dyspnea and chest pain and the quick death.

      Virchow’s Triad:

        1. stasis

        2. hypercoagulability

        3. endothelial damage

4-e

      Symptoms are consistent with GERD which is due to malfunction of LES

      Esophagitis is associated with reflux, HSV-1, CMV, candida, or chemical ingestion.

A. Cockscrew esophagus.       

B Failure to relax is achalasia and results in uncoordinated peristalsis, dysphagia,à Bird’s  Beak. Also increased risk of carcinoma. 

    C. Cause of peptic ulcer disease, gastritis, increased risk of cancer, but is not really associated with esphagael problems.

   GERD is also associated with regurg upon laying down and after meals.  People with 

GERD typically have prolonged or inappropriate relaxation of their LES

5-b

    with decreased oxygen available there is first diminished oxidative phosphorylation in the mitochondria with subsequent decrease in ATP

. Sudden occlusion of CA aerobic or mitochondrial metabolism shifts to anaerobic glycolysis (depleated glycogen granules) within seconds.  Mitochondrial metabolism is most effected and a oxidative phosphorylation stops resulting in decrease in ATP which stimulated glycolysis.   Decreased ATP results in Na/K atpase shut down which leads to cell swelling.

6-a

  Symptoms consistent with Parkinson’s Disease

7-i
the patient’s chronic HTN -> LVH -> S4

8-e

Increased enzyme activity of phosphoribosylpyrophosphate synthetase is responsible for purine overproduction and gout.

9-a
The symptoms described are characteristic of myotonic dystrophy. It is an autosomal dominant trinucleotide repeat disorder. The disease exhibits a highly variable age of onset which decreases with successive generations. Thus, the disease shows at an earlier age in successive generations which is a phenomenon known as anticipation

10-e
low C peptide due to insulin abuse; low blood glucose should suppress insulin in normal pt
Hypoglycemia is commonly caused by treated diabetes patients and rarely occurs in insulin producing tumours.  Decreased C-peptide suggests inability to make insulin (such as diabetes Type I.)Insulinoma would have hypoglycemia, high insulin levels, and high C-peptide levels. Type I diabetes would have decreased insulin and c-peptide.  The high insulin and low C-peptide (precursor to insulin)suggests that she is ingesting insulin.psych consult?

11-d
At high stringency duplexes form only between strands with perfect one-to-one complementary. Low stringency allows annealing between strands with some degree of mismatch between bases.
So when they renature they reanneal together. High stringency means that the conditions are strict and they won’t accept bad mismatches.  So mismatched dna hybridization will be prevented

12-e
mother has oligohydramnios which can be due to problems with development of kidneys or urinary tract which causes little urine production and leads to low amniotic fluid level Baby’s renal system produces amnionic fluid

13-b
seemed the most appropriate
acknowledge that she is upset, but don’t dismiss her she obviously came for a reason

14-b
Diphenhydramine is an over the counter medication with side effects including confusion, urinary retention, and mild constipation.
Diphenhydramine causes urinary retention and confusion especially in older adults

15-b
Hot nodules are more likely benign than malignant. Follicular adenomas are the most common cause of solitary nodule. They usually present as a painless mass. The patient’s nodule was found during a routine exam so it is likely a painless mass.

16-d
toxoplasmosis with ring enhancing lesion on radiograph (necrotic abscess)

cryptococcall meninge common in aids patients- mening symptoms stiff neck, headache, nausea, etc.

CMV-viral especially eye

Pneumocystis carinii= pneumonia in aids

Toxoplasma- encephalitis – parasite seen in aids

Treponema pallidum –neurosyphyllis most common in aids think tabes dorsalis

Image looks more like encephalitis than meninge.  Can see the dura

17-a

  adenomatous polyp associated with mAPC and risk of adenocarcinoma

A.tubulovillus adenoma

18-b

Edema is excess fluid outflow into the interstitium commonly caused by increased capillary pressure, decreased plasma proteins, increased capillary permeability, and increased interstitial fluid colloid osmotic pressure

19-c

Mineralcorticoid increases K loss and feedback inhibition on renin

Orthostatic hypotension is defined as a reduction of 20  mmhg in systolic and 10 in diastolic.  It occurs in a large number of elderly people.  It is a gc which has a lot of mineralcorticoid activity.  Its effects are pretty much identical to aldosterone.  It results in an increase in ECF and volume and increase in K+ in secretion by increasing the activity of the N/K ATPase  and absorbs more Na+. Aldostorone stimululates the renin angiotensin system. Thus by increasing the activity, after aldosterone feedback inhibition will decrease plasma renin.

20-b

She has symptoms of PID. On bimanual it is most likely that the mass felt was the fallopian tube

the fallopian tube is the most common place for pelvic inflammatory disease

21-c

not NADPH oxidase because hydroxyl radical and hydrogen peroxide are made at normal levels.

Not superoxide dismutase because catalyzes conversion of superoxide into oxygen and hydrogen peroxide…hydrogen peroxide and oxygen are at normal levels.

Not catalase because catalase does conversion of hydrogen peroxide to water and oxygen…and those values are normal.

Not glutathione peroxidase because (reduces free hydrogen peroxidase to water), and not involved in opsonization.

Myeloperoxidase – acts on hydrogen peroxide and chloride ions to produce hypochlorite (OCL-). We are told that HOCL production is decreased.

After opsonization, myeloperoxidase and NADPH oxidase are used.

22-c

Nitrates activate guanylate cyclase and increase cyclic guanine nucleotides. (increase cyclic GMP levels)

23-e

Pick’s disease is a frontotemporal neurodegenerative disease…frontal release signs (grasp, snout)

24-c

Digeorge syndrome. So mediastinal window (thymus) is narrow. Peripheral lymphocytes will be decreased. Gamma globulins are normal bec B cells make these, and not affected by thymus

25-a

Catalase does destruction of hydrogen peroxide

26-e

180/1000 divided by 120/1500 === 2.25

27-f

leukoplakia is precursor cancer for squamous cell carcinoma

Kaposi sarcoma – red or purple patches under the skin

Aphthous ulcer – canker sore, HSV or autoimmune

Burkitt’s lymphoma – would be larger

Candida – white thrush-y, not leukoplakia

Mixed tumor of parotid gland – roof of mouth

Warthin’s tumor – painless swelling in lower portion of parotid gland

28-a

Given to mother of premature babies to prevent hyaline membrane disease(NRDS)

29-d

Has to be on the right bec that’s what is affected by occlusion and so renin will be released on right side. Renin will be released by the vein, not artery, bec renin is from JG cells and will go to vein, not upstream to the artery

30-d

• “Severe 21-hydroxylase deficiency causes salt-wasting CAH, with life-threatening vomiting and dehydration occurring within the first few weeks of life. Severe 21-hydroxylase deficiency is also the most common cause of ambiguous genitalia due to prenatal virilization of genetically female (XX) infants.
• Moderate 21-hydroxylase deficiency is referred to as simple virilizing CAH; and typically is recognized as causing virilization of prepubertal children.
• Still milder forms of 21-hydroxylase deficiency are referred to as non-classical CAH and can cause androgen effects and infertility in adolescent and adult women.

31-d

Hemolytic uremic syndrome (microangiopathic hemolytic anemia, acute renal failure and a low platelet count (thrombocytopenia).)  we would see the narrowing of the capillary wall by fibrin deposition.

The classic childhood case of HUS occurs after bloody diarrhea caused by E. coli O157:H7, a strain of E. coli that expresses verotoxin (also called Shiga toxin). The toxin enters the bloodstream, attaches to renal endothelium and initiates an inflammatory reaction leading to acute renal failure (ARF) and disseminated intravascular coagulation (DIC). The fibrin mesh destroys red blood cells and captures thrombocytes, leading to a decrease of both on complete blood count. The usual age of onset is between 2 and adolescence

32-d
Cleft lip and palate is nonsyndromic, so multifactorial

33-a
Candida is common in diabetes. The rest are std’s. also, the image is definitely candida

34-h

BSE is a prion disorder (protein, infectious). So not DNA, RNA, but it is protein

35-a

Arginine is necessary for NO production

36-e

Alcoholics get portal htn, leading to esoph varices, which can rupture.

37-a

http://en.wikipedia.org/wiki/Hyperparathyroidism

38-d

Lots of SIGECAPS

39-b

Salycylism

40-b
Not a straight line, but still a positive correlation

41-e

FDA

REGULATES BOTH Efficacy and safety of drugs

Preclinical animal studies:

Results include Data on

1.     organ system toxicity

2.     mutagenic<AMES test> and carcinogenic potential

3.     effect on reproductive performance

4.     effectiveness of drug

clinical testing:

after IND exemption

  Phase 1: safety:

 The drug is tested in a few healthy volunteers . pharmacokinetic properties

  Phase 2: does it work/effectiveness

100/more pts in comparision with placebo/+control

Single/double blinded

  Phase 3:how well does it work/common side effects

 The drug is typically tested in 1000/ more pts , in comparision with placebo and positive control usually double-blind

Phase 4:follows a NDA, a request for marketing approval, and involves pms of adverse effects.

Quantifies common side effects,reveal less common and more severe toxicities that could warrant withdrawal

42-d

 First of all, most of the bacterial polysaccharides are T-lymphocyte independent antigens. Antipolysaccharide

immune response is characterised by lack of T-lymphocyte memory, isotype restriction and delayed ontogeny.

Children below 2 years of age and elderly respond poorly to polysaccharide antigens. Secondly, the wide structural heterogeneity among the polysaccharides within and between species is also a problem. Thirdly, some bacterial polysaccharides are poor immunogens in humans due to their structural similarities with glycolipids and glycoproteins present in man. The T-lymphocyte independent nature of a polysaccharide may be overcome by conjugating the native or depolymerised polysaccharide to a protein carrier. Such neoglycoconjugates have been proven to be efficient in inducing T-lymphocyte dependent immunity and to protect both infants as well as elderly from disease. Another approach to circumvent the T-lymphocyte independent property of polysaccharides is to select peptides mimicking the immunodominant structures. Several examples of such peptides have been described.

B lymphocytes recognize 5-6 amino acids in case of protein / 4-5 hexose units of polysacc

T lym recognize 10-20 amino acids in length on surface of MHC of APC

TH cells necessary for immunolo memory

So H. inf type b coupled to protein – N. men OMP / diphtheria toxoid

Polysacch capsule vaccines 0f N.men and S.pneu not administered with protein component

43-b

first step: which artery is involved? as seen in angiogram this artery arise form proximal portion of basilar artery, so this is anterior inferior cerebellar artery (AICA).

second step: which structures supply AICA. AICA supplies the caudal lateral pontine tegmentum, and inferior surface of the cerebellum.

third step: choose from given answer options which is characteristic for cerebellar dysfunction. a, d, e are characteristic for hemisphere

c. is characteristic for basal ganglia

only b. ataxic limb movements left, which is the correct answer

44-d
The reaction goes from Substrate to Product ,  S to P

When ∆ G is –, the reaction goes in direction from S to P

When ∆ G is + , the reaction goes from P to S

v-w-x-y-z

the reason being that G0 is spontaneous when it is negative.. these reacations are reversible. so y-->z is +5.7 so then z--->y is -5.7 meaning THAT IS THE MOST SPONTANEOUS REACTION and so you would accumulate Y..

if G is negative number reaction goes forward

if G is a positive number reaction cant occur and requires energy

so now from the values given u can easily go from v -w

w-x ,little energy is required

now x will be spontaneously converted to y becoz G is negative

but y-z requires a lot oh energy .......so y will accumulate.

- delta G means that reaction is favorable. More - delta G, more favorable reaction. +delta means that reaction is unfavourable. More + delta G, more unfavourable the reaction. So, V->W reaction (deltaG -4,0) very favourable, it will lead to accumulation of large quantitie of product W.

In the presence of large amount of W, second little unfavourable reaction (deltaG +0,4)

W->X will proceed.

X->Z reaction (deltaG -3,5) is also very favourable, and results in accumulation of product Y.

last reaction (deltaG +5,7) very unfavourable. so it would not occur at all.

So correct answer is D. Y will accumulate in the largest amount at equilibrium.

45-a

How many fatal recreational cases (1) to all recreational cases( 12 )

Case Fatality is number of deaths/ number of diagnosed patients  1/12

46-d

 Presence of viable sperm in ejaculate. The man must continue to use contraception (such as a condom) until an examination of his semen reveals that no sperm are present. The disappearance of sperm from the semen is not detectable by the patient. Only a specific laboratory and microscopic analysis of the semen can verify the total lack of sperm, which is the goal of the vasectomy surgery.

47-c

48-c
age and typical clinical picture

49-d

50-a
which goes to the pericardium and create hemopericardium that is why distant heart sounds and diffuse  wet inspiratory cracles

Pain radiates to the back , long history of poorly controlled hypertension

Blood pressure difference on R and L hands

Pseudohypotension (falsely low blood pressure measurement) may occur due to involvement of the brachiocephalic artery (supplying the right arm) or the left subclavian artery (supplying the left arm).

Early diastolic Aortic regurgitation The murmur is low intensity, high-pitched, best heard over the left sternal border or over the right second intercostal space, especially if the patient leans forward and holds breath in full expiration. The radiation is typically toward the apex. The configuration is usually decrescendo and has a blowing character. The presence of this murmur is a good positive predictor for AR and the absence of this murmur strongly suggests the absence of AR. An Austin Flint murmur is usually associated with significant aortic regurgitation