NBME 1 Block 2

1-e
type II  pneumocytes help regeneration after injury

2-a

- no hemolysis since retics normal.  not folate since not macrocytic.  marrow aplasia only with myelophthisis late in disease.  Fe/TIBC = 25/150 = 16.7%, so either anemia of chronic disease or iron deficiency.  since cancer is a chronic disease, likely abnormal utilization of iron.

3-a

it is cocaine toxicity

4-c

Recombination- exchange of genetic material

5-c

Sulfonylureas-->Closing of the K channels --->depolarization-->release of insulin via Calcium influx--> hypoglycemia

6-e

unable to determine because the question did not give us that specific year to calulate for that year

7-f

8-d
membranous glomerulonephrities is caused by drugs like Penicillamine,Gold ,NSAID

9-d

10-a

11-a

The situation describes cardiac tamponade with hypotension, neck vein distension, and pulsus paradox. The other options don’t make sense. Other conditions with PP include COPD and asthma

12-d

MHC I is associated with endogenous antigen. MHC II is associated with exogenous antigensThe two clues are: 1) it's a subunit vaccine (as opposed to a live-attenuated virus, in which case the answer would be C), and 2) The nonresponders have a certain HLA type.

The B-cell receptor is an antibody derived from DNA splicing of VDJ genes, it has nothing to do with HLA type. The genes are on completely different chromosomes. Similar reasoning for why the T-cell receptor is not the correct answer.
Since the virus is a subunit vaccine, it does not replicate inside cells, and therefore MHC I plays no role. Therefore, the answer must be that MHC II does not properly present the peptide

13-a

This is a childhood hemangioma. Though called "birthmarks", they often do not become noticeable until a few days to weeks after birth. Hemangiomas grow in size for about 6-12 months and then involute over a period of years. Most hemangiomas do not cause problems and thus do not need treatment.

14-c

The patient has squamous cell carcinoma as seen by the keratin “pearls” in the lesion biopsy. UV-B radiation plays a role in this pathogenesis and exposure can be avoided by using sunscreen cream.

15-d

Interleukin-1 (IL-1), a monokine, has a variety of functions. IL-1 fulfills its role mainly in inflammatory and in the immune response. During inflammation, injury, immunological challenge or infection, IL-1 seems to mediate, in part, the pathogenesis of disease. IL-1 is mainly released by macrophages. IL-1 also induces the production of Interleukin-2 by T-cells that have been stimulated by antigen or mitogen.
16-h
The question asks for the location of the MYOTOME. I is the dermatome and G is the sclerotome. You can see the myotome enveloping the developing sclerotome.

17-a

Fragile X is a triplet repeat disorder with variable repeats of the CGG trinucleotide. Other trinucleotide repeat disorders to know for the boards are Huntington’s Disease, Myotonic Dystrophy, and Friedreich’s Ataxia

18-c

Enalapril is an ACE inhibitor. It is the only class of drugs among the options given, that can cause serious embryopathy

19-g

The only option that is consistent with all the characteristics given is Wegener’s. The necrotizing arteritis should be a big tip-off.

20-b

The patient has Hashimoto’s thyroiditis. Her TFTs point to hypothyroidism. Hashimoto’s is associated with non-tender thyromegaly. Upon histology, you can see a lymphocytic infiltrate with germinal centers. Also remember Hashimoto = Hurthle cells.She is still producing T4 so A can be ruled out. Noncaseating granulomas point to de Quervain’s thyroiditis which is a self-limited hypothyroid state following a flu-like illness. This process is more acute and would present with a very tender thyroid gland. D is Graves’ and E is toxic MNG, which both lead to hyperthyroidism

21-b

Heparin binds AT-III which then inactivates thrombin and factor Xa.

22-c

codon on mRNA 5’ to 3’ will be GCU

23-d

Dantrolene block Ca²⁺ inflow to muscle and is the only option that makes sense here.

24-c

Microglia are macrophages of the brain. They are derived from myeloid progenitor cells in the bone marrow. MPCs also develop into macrophages and dendritic cells.

25-c

Remember that the Topoisomerase inhibitors (etoposide, doxorubicin) and the microtubulin inhibitors (vincristine, vinblastine) are pumped out by P-glycoprotein. We didn’t learn about Dactinomycin but it is an anticancer agent used in childhood tumors such as Wilms’, Ewing’s and rhabdomyosarcoma. It is also pumped out of the cell

26-d

One has to go back to Embryology to figure this one out (yeah!). Remember that the embryonic “midgut” was supplied by the SMA and the embryonic “hindgut” was supplied by the IMA. The splenic flexure remained a watershed region. This will be affected the most if both the SMA and IMA supplies are attenuated.

27-d

Glucagon can á intracellular cAMP while averting the β-adrenergic receptor. Given when someone has a β-blocker overdose.

28-c

I remember Stein telling us that prevalence was essential in figuring out predictive value. Sensitivity and specificity don’t mean much without prevalence.as the prevalence increases,positive predictive value increases too

29-c

Remember any lesion after the optic chiasm will have homonymous hemianopsia 

30-b

Cyclooxygenases help in the production of TxA₂ and prostacyclin (PGI₂). Prostacyclin is the predominant prostaglandin produced by endothelial cells and inhibits platelet aggregation. It is also a potent vasodilator.

31-a
It is one of the four rotator cuff muscles and also abducts the arm at the shoulder. The spine of the scapula separates the supraspinatus muscle from the infraspinatus muscle, which originates below the spine

32-f
You can’t discuss the patient case in public place, because it will break the confidentiality

33-b

sensitive about negative criticismHe feels they will ridicule himPeople with AvPD often consider themselves to be personally unappealing, and avoid social interaction for fear of being ridiculed, humiliated, rejected, or disliked.AvPD is usually first noticed in early adulthood, and is associated with perceived or actual rejection by parents or peers during childhood. Whether the feeling of rejection is due to the extreme interpersonal monitoring attributed to people with the disorder is still disputed

34-c

Spermatids have 1N haploid

35-d

• This soluble molecule diffuses through the cytosol and

• binds to receptors on the endoplasmic reticulum causing

• the release of calcium ions (Ca²⁺) into the cytosol.

The rise in intracellular calcium triggers the response.

36-b

candida endocarditis in IV drug abuser

37-e

38-c

39-c

http://en.wikipedia.org/wiki/Cell_adhesion_moleculeIntegrins are receptors that mediate attachment between a cell and the tissues surrounding it, which may be other cells or the extracellular matrix (ECM)     http://en.wikipedia.org/wiki/Integrin
Also play a role in cell signaling; bind to cell surface and ECM components such as fibronectin, collagen and laminin.

40-a

Tamoxifen is an antagonist of the estrogen receptor in breast tissue. It has been the standard endocrine (anti-estrogen) therapy for hormone-positive early breast cancer in post-menopausal women.
effectiveness of tamoxifen for the prevention of breast cancerRaloxifene is currently used for the prevention and treatment of osteoporosis in postmenopausal women.Unlike tamoxifen, raloxifene doesn't exert estrogen-like effects on the uterus.

41-d

rebound tenderness is very specific for peritonitis or appendicitisRebound tenderness is also called Blumberg’s Sign Rebound tenderness is a clinical sign that a doctor may detect in physical examination of a patient's abdomen. It refers to pain upon removal of pressure rather than application of pressure to the abdomen. (The latter is referred to simply as abdominal tenderness.)  It represents aggravation of the parietal layer of peritoneum by stretching or moving. Rebound is regarded as one of the classic local signs of peritonitis

42-f

pleural effusion = dullness to percussion, decreased breath sounds, and decreased tactile fremitus
(http://www.emedicine.com/emerg/topic462.htm )

43-a

Salbutamol (INN) or albuterol (USAN) is a short-acting β₂-adrenergic receptor agonist used for the relief of bronchospasm in conditions such as asthma and chronic obstructive pulmonary disease
Albuterol
Gs increase Adenylate cyclase and produce more cAMPBeta1and beta2 work through Gs
So the medication should work through beta 2 r-rs
The only choice here is Albuterol
BronchodilationBeclomethasone. prednisone—inhibit the synthesis of virtually all cytokines. Inactivale NF-KB, transcription faclor that induces the production of TNF-aipha
Theophylline—likely causes bronchodilation byinhibiting phosphodiesterase, thereby decrease cAMP hydrolysisalbuterol increases c AMP

44-a

BRANCHIAL CYSTS (or branchial cleft cysts)
Are congenital cysts, that arise in the lateral aspect of the neck when the second branchial cleft fails to close during embryonic development. At about the fourth week of embryonic life, 4 branchial (or pharyngeal) clefts develop between 5 ridges known as the branchial (or pharyngeal) arches. These arches and clefts contribute to the formation of various structures of the head and neck.
Are congenital cysts, that arise in the lateral aspect of the neck when the second branchial cleft fails to close during embryonic development. At about the fourth week of embryonic life, 4 branchial (or pharyngeal) clefts develop between 5 ridges known as the branchial (or pharyngeal) arches. These arches and clefts contribute to the formation of various structures of the head and neck.

45-c

CFTR is expressed in epithelia and functions as a Cl- channel regulated by cyclic adenosine monophosphate (cAMP)-dependent protein kinase and intracellular ATPCystic fibrosis transmembrane conductance regulator (CFTR) is a protein that in humans is encoded by the CFTR gene. CFTR is a ABC transporter-class ion channel that transports chloride and thiocyanate ions across epithelial cell membranes. Mutations of the CFTR gene affect functioning of the chloride ion channels in these cell membranes, leading to cystic fibrosis and congenital absence of the vas deferens
CFTR functions as a cAMP-activated ATP-gated anion channel, increasing the conductance for certain anions (e.g. Cl-) to flow down their electrochemical gradient.

46-a

during gametogenesis,mitochondria of sperm degenerate and only maternal mitochondria are inheretid

47-d
vit b12 need intrinsic factor and IF and acid are produced by the fundus and body of stomach.both of them in combination r absorbed in ileum

48-c

Tumors are more likely benign in women younger than 45 years of age.the lady in Q is 65.Genetic factors include,,,as follows
Mutations of BRCA1 and BRCA2 suppressor genes
Lynch syndrome
Turner's syndrome,,,,,,,,,,Increased risk for dysgerminoma
Peutz-Jeghers syndrome  ,,,,,,Increased incidence of sex cord tumors with annular tubules
Smoking cigarettes and
OCPs decrease risk ,,,it decreased number of ovulatory cycles
cancer marker is CA125

49-d
facia transversalis...
thin aponeurotic membrane which lies between the inner surface of the Transversus abdominis  and the extraperitoneal fascia.

It forms part of the general layer of fascia lining the abdominal parietes, and is directly continuous with the iliac and pelvic fasciae.

In the inguinal region, the transversalis fascia is thick and dense in structure and is joined by fibers from the aponeurosis of the Transversus, but it becomes thin as it ascends to the diaphragm, and blends with the fascia covering the under surface of this muscle.
Behind, it is lost in the fat which covers the posterior surfaces of the kidneys.

50-c
its an enzyme of glycolysis.

FA source:Regulation by F2,6BP

FBPase-2 and PFK-2 are part of the same complex but respond in opposite manner.s
to phosphorylation by protein kinase A.
Fasting state: inc  glucagon--- -> inc  cAMP--- -> inc protein kinase A -----> inc FBPase-2 and dec PFK2.
Fed state: inc insulin .......dec cAMP ----->  protein kinase A --------» dec FBPasc and incPFK-2.