ANSWERS LATEST 2023-2024 (usmle step 1)MEDICAL
EXAMINATION/NBME CBSE REAL EXAM 200
QUESTIONS AND ANSWERS LATEST (usmle step
1)MEDICAL EXAMINATION
70yo M dies in a motor vehicle collision. Was undergoing evaluation for occult
blood in the stool. Photo of transverse colon shown. Dx? - ✔✔ANSWER✔✔-
Tubular adenoma or villous polyp. GI blood loss suggests a risk for malignancy
38yo M truck driver with 1-week hx of watery, itchy eyes and a runny nose.
Physical shows inflamed nasal mucosa. No congestion in lower lung.
Pharmacotherapy? - ✔✔ANSWER✔✔-Loratadine--> less sedating
antihistamine
16yo girl with 3-day hx of fever, nonproductive cough, and fatigue. T 38.3, P
88/min, BP 102-70. PE shows pale conjunctivae. CXR shows bilateral interstitial
infiltrates. Blood spontaenously agglutinates while awaiting transport to the
laboratory. Antibody isotypes causing agglutination? - ✔✔ANSWER✔✔-IgM
(mono and mycoplasma)
24yo M with small tender blisters on his penis 3 days after unprotected sex.
Photograph shown. Causal agent? - ✔✔ANSWER✔✔-HSV-2
42yo F with 3-year hx of an intermittent facial rash, including the forehead,
eyelids, nose, and cheeks. Rash seems to be getting worse since she moved
from New York to Florida last year. Spicy foods precipitate a flushing reaction
,that seems to exacerbate the rash. PE shows erythema over the nose and
cheeks, with scattered telangiectasias and a few papules. Dx? -
✔✔ANSWER✔✔-Rosacea
53yo M returned from Africa, has fever, headache, and abdominal discomfort.
Received appropriate vaccinations prior to the trip. T 39.4C. A wright-stained
peripheral smear shown (ring forms in RBCs). Dx? - ✔✔ANSWER✔✔-Malaria
68yo F with T2DM and hypertension that has been poorly controlled despite
hydrochlorothiazide treatment. BP 150/96, Labs show serum glucose
concentration of 130 and proteinuria. In addition to current Rx, which is most
appropriate pharmacotherapy? - ✔✔ANSWER✔✔-ACE I (Lisinopril)
66yo M with stage IV colon cancer with 3-day hx of severe diarrhea after
receiving chemotherapy with flourouracil, leucovorin, and irinotecan.
Prescribed opioid antidiarrheal agent with no CNS effects. Which med? -
✔✔ANSWER✔✔-Loperamide
35yo M in ED with 2-hour hx of sever fatigue and dizziness. Had profuse,
watery diarrhea for 8 hours despite a lack of oral intake. Recently returned
from a medical relief trip to a remove village in Honduras. T 36.7 C, P 122/min,
BP 90/50. PE shows dry skin and decreased capillary refill. Stool for occult
blood is negative; stool is gray and turbid. Gram stain shows gram-negative,
comma-shaped bacteria; no erythrocytes of leukocytes. MOA of toxin? -
✔✔ANSWER✔✔-V. Cholerae--> activates AC
59yo F with gradual onset of lack of muscle control in her left arm and leg. Sx 1
mo ago after dx with metastatic breast cancer. PE shows ataxia of left upper
and lower extremities. Muscle strength, DTR, sensation, proprioception
normal. Metastatic tumor in which location? - ✔✔ANSWER✔✔-Cerebellum
,Newborn delivered at 38 weeks' gestation weighs 1800 g. PE shows petechial
rash, microcephaly, and hepatosplenomegaly. Serologic test for CMV: IgG + in
mother, + in newborn; IGM - in mother, + in newborn. Explanation? -
✔✔ANSWER✔✔-Congenital CMV infection
Female newborn is delivered at 38 weeks' gestation. Apgar 8 and 8 at 1/5 min.
PE shows a bulging, fluod0filled mass approximately 5 cm in diameter in the
midline over the lumbosacral region. No spontaneous movements of the lower
extremities. Abnormality most likely occurred because of abnormal
development during which periods of postconception (in days)? -
✔✔ANSWER✔✔-15-40; neutral tube closes at about 4 weeks
64yo M in ED 3 hours after SOB with exertion and extreme fatigue. Has
ischemic heart disease. P 125/min, BP 105/60. ECG shows atrial fibrillation.
Intravenous ibutilide is administered. Ten minutes later, ECG shows normal
sinus rhythm. Risk for which drug effect in the next 6 hours? -
✔✔ANSWER✔✔-Torsades de pointes
65yo F with 20-year hx of osteoarthritis of the hands now has pain radiating
down the distal anterior thigh, knee, medial leg, and food. Bony outgrowth of
vertebrae compressing one of the spinal nerves is suspected. Nerve root in
which intervertebral foramina is effected? - ✔✔ANSWER✔✔-L3 to L4
38yo M with 3-year hx of T2DM. Taking an oral antihyperglycemic agent, he
has tried diet and exercise. BMI 32. PE normal. Hb A1c is 10%. Physician
recommends initiation of insulin injections. Responds, "I know that insulin
would help control my blood sugar. But a lot of people in my family have
diabetes, and insulin made them really sick at times. Patient is at which stage
of change? - ✔✔ANSWER✔✔-Contemplation
24yo M with 2-day history of an itchy rash on his arms and legs. Returned from
a camping trip in the woods 5 days ago. PE shows edematous, erythematous
, rash with linear vesicles. Cause is activation of which cell types? -
✔✔ANSWER✔✔-T-lymphocytes (type IV HS)
70yo M from china with poorly differentiated monoclonal carcinoma of the
nasopharynx. DNA probes of neoplastic cells are most likely to detect genome
of which virus? - ✔✔ANSWER✔✔-EBV
24yo M with hx of IVDA could not be aroused. Friend reports that the patient
injected himself with a drug 6 hours ago. Labs show drug concentration of 0.3.
Assuming first-order one-compartment kinetics, has a half-life of 2 hours, and
a volume of distribution of 200 L in this patient. What is quantity of drug (in
mg) injected? - ✔✔ANSWER✔✔-= 200 (0.3) =60
3 half-lives = 120, 240, 480
Compound is taken up by bacterial cells. No energy is necessary for uptake,
and the compound is not concentrated in the cell. Which describes this
mechanism of transport? - ✔✔ANSWER✔✔-Carrier-mediated diffusion
Newborn has male genital ducts but female external genitalia. Cytogenetic
analysis shows a 46,XY karyotype, and genetic testing shows a mutation of the
gene encoding 5alpha-reductase. In absence of this mutation, labia majora
would have been? - ✔✔ANSWER✔✔-Scrotum
Corresponded to penis shaft? - ✔✔ANSWER✔✔-Labia minora
Study designed to evaluate the efficacy of coenzyme Q10 in improving cardiac
output in patients with CHF. Sixty patients with CHF are recruited. Each
assigned by coin toss to one of tw groups. Design? - ✔✔ANSWER✔✔-RCT