NBME 12 questions! please help!!
1-A 2495-g (5-lb 8-oz) female newborn is delivered at term to a 30-year-old woman who had no prenatal care. Physical examination of the newborn shows jaundice, nasal flaring, and grunting. Laboratory studies show marked anemia and hyperbilirubinemia. Further testing shows that the newborn is blood group O, Rh-positive, and the mother is blood group O, Rh-negative. Which of the following most likely mediated the transplacental transfer of the maternal factor causing this newborn's symptoms?
A. C3b receptor
B. Fc receptor
C. Interleukin-2 (IL-2) receptor
D. T-lymphocyte receptor
E. Transferrin receptor
2-In a patient with chronic peripheral neuropathy, enzyme histochemical staining of a muscle biopsy shows fiber grouping. Which of the following is most likely cause of this finding?
a) altered expression of muscle enzyme due to damaged nerve fibers
b) altered trophic substance from the innervating neurons
c) regeneration of muscle fibers (WRONG ANSWER)
d) reinnervation of muscle fibers by regenerating axons
e) selective loss of nerve fibers to type II muscle fibers
3. A 24yo woman is brought to ER by roommate cause of vomiting for 4 hrs. Also has 2day history of fatigue adn dizziness on standing. severe heartburn past 3 months. Antacids help provide relief. Pulse 110, RR 25, BP 95/70, Physical exam shows marked pallor, Hb 6 and Hct is 18. What is decreased in this patient?
a. alveolar Po2
b. arterial O2 carrying capacity
c. Arterial oxyhemoglobin saturation
d. arterial p50
e. arterial Po2
4. A 9-year-old boy is brought to the emergency department because of a 6-hour history of fever, headache, and stiff neck. His temperature is 39°C (102.2°F). Physical examination shows nuchal rigidity and a diffuse nonblanching rash. A Gram stain of cerebrospinal fluid shows gram-negative intracellular diplococci. Which of the following components of this pathogen is used to determine serogroup specificity and is a component of the vaccine for this organism?
A. Capsule (Is it this??)
E. Porin Proteins
I chose D, because I read somewhere that said the vaccine against N.meningitidis is not effective because their pilli is in a constant change.. but that's antigenicity, not for the serogroup clasification, isn't it?
5. A male newborn delivered by c section at 28 weeks' gestation develops hyaline membrane disease. His mother was admitted to the hospital 2 days ago because of decreased fetal movement. She was treated with dexamethasome to promote synthesis of surfactant of fetal lung. Dexamethasome was the most appropriate treatment to promote the differentiation of surfactant-producing cells through specific binding to which of the following cellular components:
a/ clathrin-coated pits (WRONG) g/ nucleoporins
b/ golgi apparatus h/ occludins
c/ G protein linked receptors I/ peroxisomes
d/ microvilli J/ rough endoplasmic reticulum
e/ multilamellar bodies k/ tyrosine kinase - linked receptors
f/ nuclear receptors
As far as I know, Glucocorticoids bind to cytosolic receptors...
6. A study is conducted to assess the effectiveness of a registry for identifying patients 50 years old and older eligible for colon cancer screening. Medical practices are selected based on equal and proportional representation of both genders and socioeconomic and ethnic groups, including those who have medical insurance and those who do not. Half of the practices will use the registry for a 15-year period and the other half will provide usual care without the registry during the same period. Results show that the colon cancer mortality rate is decreased in the practices using the registry, and the researchers recommend use of a patient registry to decrease the number of deaths due to colon cancer. Which of the following study characteristics most directly supports the researchers' recommendation?
B. External validity
C. Face Validity
E is wrong
7. A 55-year-old man is admitted to the hospital because of a 2-day history of vomiting and severe abdominal pain in the right upper quadrant. He drinks six 12-ounce beers daily. Abdominal examination shows spider angiomata. The liver is hard and nodular on palpation. A CT scan of the abdomen is shown; the arrow indicates a mass. Hypertension of which of the following veins is most likely in this patient?
*their was a CT, and I dont know how to upload it
B Inferior phrenic
D Short gastric
A is wrong
8. During an experiment an investigator compares the immune response of a lymphocytes from a 2 month old mice with that of a 2 year old mice. There is a decrease in responses to the Chlamydophila pneumoniae in older mice. An age related change in which of the following cell types is the most likley cause of this decreased immune response?
A. B lymphocytes
D. Plasma Cells
E. T lymphocytes
I chose Macrophages.. but it seems to be E the right answer.. can somebody explain me this please??
One more question!
A 45-year-old man is admitted to the hospital for treatment of septic shock from a pneumoccocal infection. He is hypotensive for 12 hrs ans subsequently develpos increase in creatinine serum concentration with decreased in urine output. Despite apprpiate care, he dies 1 day later. At autopsy, examination of the kidneys shows necrosis of many of the renal tubular cells without damage of the underling stromal framework of the glomeruli. If this px had survived with healing of the kidneys, which of the following renal outcomes would have been most likely?
a- Diffuse renal scarring
b- renal atrophy
e- Normal arquitecture
It's E, but Why???
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