[Medicalstudyzone.com] NBME 22 Q.pdf

. A 49-year-old man comes to the physician because of increasingly severe pain in his left hip during the past 2 months. He was recently discharged from a rehabilitation facility for treatment of alcoholism. He says , "The pain gets so bad at times that it even hurts my golf game. " He has...

. A 49-year-old man comes to the physician because of increasingly severe pain in his left hip during the past 2 months. He was recently discharged from a rehabilitation facility for treatment of alcoholism. He says , "The pain gets so bad at times that it even hurts my golf game. " He has pain with weight bearing. Physical examination shows limited active and passive range of motion of the left hip. Hip x-rays show no abnormalities A coronal Trweighted MRI is shown. Which of the following is the most likely cause of this patient's pain? A) Avascular necrosis B) Hyperparathyroidism C) Osteitis deformans D) Septic arthritis E) Tuberculous osteomyelitis A 16-year -old girl has pain and tingling in her left hand when she goes backpacking. The symptoms resolve 5 minutes after she takes off her backpack. Which of the following abnormalities is the most likely cause? A) C-7 to T-1 congenital fusion B) Cervical rib C) Diastematomyelia D) Hemivertebra E) Spina bifida occulta of C-7 A 48-year -old man comes to the physician because of fatigue, increasing shortness of breath on exertion, and decreased exercise tolerance over the past 4 months. An x-ray of the chest shows cardiac enlargement and prominent pulmonary vasculature. He is treated pharmacologically but subsequently develops glucose intolerance, evidence of liver dysfunction , and mild to moderate ascites. An older brother died at age 52 years with similar symptoms. Which of the following are the most important screening tests to perform on this patient and his family? A) Fasting serum gastrin and insulin measurements B) Hepatitis B and hepatitis C antibody assays C) HLA class I and class II typing D) Serum thyroid-stimulating hormone and thyroxine (T measurements E) ^ Transferrin saturation and serum ferritin measurements A 32 - year - old woman begins to hyperventilate and then develops blurred vision and numbness around her mouth after being told her best friend has suddenly died. Her pulse is 95/min and blood pressure is 120/80 mm Hg. Which of the following is most likely decreased in this woman? A) Arterial blood oxygen concentration B) Arterial blood Po 2 C) Arterial pressure D) Cerebral blood flow E) Cerebral tissue pH A 2-month-old boy is brought to the physician because of a 7-day history of hoarseness His mother has AIDS and used cocaine throughout her pregnancy. Physical examination shows no abnormalities A fiberoptic laryngoscopic examination shows a nodule on the left vocal cord. Which of the following viruses is the most likely cause of this nodule? A) Cytomegalovirus B) Herpes simplex virus C) HIV D) Human papillomavirus E) Varicella-zoster virus A 16-year-old girl is brought to the physician because of excessive dieting, constant studying, and social withdrawal during the past 3 weeks. She is 168 cm (5 ft 6 in) tall and weighs 48 kg (106 lb); BMI is 17 kg/m 2. Her blood pressure is 95/66 mm Hg Physical examination shows dry skin and fine hair growth. Laboratory studies show : Serum Na * 138 mEq/L K+ 2.2 mEq/L Cl- 90 mEq/L HCO 3- 36 mEq/L Urea nitrogen 25 mg/dL Creatinine 1.2 mg/dL Arterial blood gas analysis on room air pH 7.48 Pco 2 48 mm Hg Po, 97 mm Hg This patient has most likely been abusing which of the following substances? A) Alcohol B) Amphetamines C) Diuretics D) Laxatives E) Thyroid hormone A 67-year - old woman comes to the physician because of a 1-year history of a nonproductive cough and progressive shortness of breath with exertion. She has not had fever or any other symptoms. She has no history of serious illness and takes no medications. She does not smoke. Vital signs are within normal limits. Pulse oximetry on room air shows an oxygen saturation of 92%. Fine, dry crackles are heard at both lung bases. Physical examination shows clubbing of the hands. There is no peripheral edema. A chest x-ray shows fine linear opacities in the lower third of the lungs bilaterally. A CT scan of the chest shows bibasilar interstitial reticulonodular markings with interlobular septal thickening Pulmonary function tests show a normal FEVt an FVC of 48% of predicted, and diffusion capacity of the lung for carbon monoxide of 55% of predicted. Which of the following is the most likely diagnosis? A) Allergic granulomatous angiitis (Churg-Strauss syndrome) B) Bronchoalveolar carcinoma C) Emphysema D) Idiopathic pulmonary fibrosis E) Lupus pneumonitis A 17-year - old boy is brought to the emergency department 45 minutes after he collapsed while competing in a high school wrestling competition He is 178 cm (5 ft 10 in) tall and normally weighs 61 kg (135 lb), but he competes in the 58-kg (128-lb) weight class. On arrival, he is alert. His pulse is 104/min, and blood pressure is 90/55 mm Hg Physical examination shows pallor and diaphoresis. After administration of intravenous fluids, he says he feels "back to normal.” On further questioning , he says that he was afraid that he would not qualify to compete in his weight class, so he took a long steam bath and used a laxative prior to the match to quickly lose 2.3 kg (5 lb). Laboratory studies are most likely to show which of the following? A) Hypercalcemia B) Hyperuricemia C) Hypokalemia D) Hyponatremia E) Hypophosphatemia A 12-year - old girl is referred to the emergency department by her physician because she has been unable to walk for 5 days. Her parents appear very anxious , but she seems unconcerned about her symptoms. Her temperature is 37 0°C (98.6°F), pulse is 70/min, and blood pressure is 115/70 mm Hg. Deep tendon reflexes in the lower extremities are equal bilaterally. Sensation to pain and to light touch is variable. Which of the following is the most likely diagnosis? A) Brief psychotic disorder B) Conversion disorder C) Depersonalization/derealization disorder D) Illness anxiety disorder (hypochondriasis) E) Post-traumatic stress disorder An 85-year -old woman is diagnosed with a fracture of the right femur and begins treatment with morphine by patient-controlled analgesic pump Three days later, her respirations are 6/min. Physical examination shows pinpoint pupils. Her serum creatinine concentration is 1.8 mg/dL. Which of the following best explains this patient's clinical deterioration after the initiation of morphine therapy? A) Chronic dosing of morphine decreases its bioavailability B) Morphine bioavailability increases with chronic dosing C) Morphine downregulates p-opioid receptors with chronic dosing D) Morphine inhibits its own metabolism E) Morphine is metabolized to active metabolites that accumulate A 50-year - old man who is a college professor has had an increasing cough for 6 months and hemoptysis for 1 week He has smoked 1 pack of cigarettes per day for the past 32 years. He plays squash twice a week and swims 3 times a week. An x-ray of the chest shows a 3 * 4 -cm hilar mass. Cytologic examination of sputum shows non-small cell carcinoma. The physician tells the patient he has lung cancer. The patient responds, "How can this be happening to me? I eat right and exercise.” Which of the following responses by the physician is most appropriate? A) "Don't worry. I will be there for you and make sure everything turns out the way you want." B) "Eating right and exercising will not help prevent cancer." C) "In fact , as you probably know, the major risk for lung cancer is smoking. " D) "It must be difficult for you to accept this diagnosis when you feel healthy." E) "Regardless of your good habits, it's time to realize that you have lung cancer."  B, C, D , and ^tfn VAensrtiv ^^ ^^ ^ f0 ® n itMtVan^ oTeach cutoflpol'nt '' ^^ EX the cancer? ^ specif ity re p otted gra 100 - 1 1 > B c D E C A 500), and plasma HIV viral load greater than 1 million copies/mL. Results of a serum HIV antibody test are negative. Which of the following best explains this patient's condition? A) Acute retroviral infection B) HIV-2 infection C) HTLV infection D) Late-stage AIDS A 50-year - old man is admitted to the hospital because of severe chest pain for 30 minutes. An ECG shows ST-segment elevation in the anterior chest leads. Serum studies show increased creatine kinase activity and troponin I concentration. Compared with the electrolyte content of normal myocardiocytes found in a healthy, asymptomatic 50-year-old man which of the following best reflects the electrolyte content of the myocardiocytes that produced the increased enzymes in this patient? Intracellular [Na +] Intracellular [K +] Intracellular [Ca 2+] A) Decreased decreased decreased B) Decreased decreased increased C) Decreased increased increased D) Increased decreased decreased E) Increased decreased increased F) Increased increased increased A 43- year - old man is brought to the emergency department 1 hour after forcible eversion of his left foot while jogging on uneven ground. Walking is limited by pain. He rates the pain as 7 on a 10-point scale His vital signs are within normal limits Physical examination shows tenderness and swelling over the lateral malleolus. An x-ray of the left lower extremity shows a fracture of the fibula above the distal tibiofibular articulation Contraction of which of the following muscles most likely caused this patient's pain at the fracture? A) Extensor digitorum longus B) Fibularis (peroneus) brevis C) Fibularis (peroneus) tertius D) Flexor digitorum longus E) Tibialis anterior F) Tibialis posterior A 28-year - old man who is seropositive for HIV has numerous nonulcerated purple nodules on the skin. Examination of tissue obtained on biopsy of a lesion is most likely to show which of the following? A) Aggregates of large atypical lymphocytes B) Granulation tissue containing pseudohyphae and budding yeasts C) Intracellular yeasts in macrophages D) Macrophages containing acid-fast bacilli E) Multinuclear cells containing intranuclear inclusions F) Slit-like vascular spaces with plump spindle-shaped stromal cells A 73-year-old man comes to the physician with his wife because of a 3-year history of daytime sleepiness His wife says that he snores loudly. He is 183 cm (6 ft) tall and weighs 113 kg (250 lb); BMI is 34 kg/m 2. His pulse is 84/min , respirations are 18/min, and blood pressure is 175/105 mm Hg. Physical examination shows congested conjunctivae and centripetal obesity. Serum studies show a glucose concentration of 250 mg/dL, creatinine concentration of 2 mg/dL, and uric acid concentration of 10.1 mg/dL Polysomnography confirms the diagnosis, and treatment with nasal continuous positive airway pressure at night is started. This therapy will most likely cause a decrease in which of the following? A) Blood pressure B) Pulse rate C) Serum creatinine concentration D) Serum glucose concentration E) Serum uric acid concentration  A 30-year-old man and a 24-year-old woman (indicated by the arrows) request preconceptional counseling because the man's brother has type I oculocutaneous albinism. This is an autosomal recessive, single gene disorder thought to occur about once in every 40 , 000 persons in the general population Assume that the alleles are in equilibrium in the population, that the woman' s family history is negative for this disorder, and that the two probands have neither shared relatives nor common ethnicity A pedigree is shown Which of the following is the best estimate 6 that their child will be affected with oculocutaneous albinism? i A) 1 in 4 B) 1 in 100 C) 1 in 200 * * D) 1 in 600 E) 1 in 40, 000 A 65-year - old man starts using topical fluorouracil for treatment of actinic keratoses on his scalp. Fluorouracil is most likely effective for this patient because it inhibits which of the following enzymes? A) Thymidine kinase B) Thymidine reductase C) Thymidylate synthase D) Uracil phosphoribosyltransferase E) Uracil reductase A 73- year - old man has difficulty urinating and frequent urination. Improvement of these symptoms is most likely to result from treatment with a drug that blocks which of the following labeled sites? Tyrosine *4 DOPA Choline 4i » Storage ** granule m Acetylcholine Bti I c Q Acetylcholinesterase Reuptake carrier -® rn — f Acelylchollne receptor H O A) OB) O C) O D) O E) OF) O G) OH) O I) A 32 - year - old man comes to the physician because of a 2-week history of persistent thrush. He has been receiving a multidrug regimen including zidovudine (AZT) for 3 years, but he has had difficulty with compliance. Laboratory studies show a CD4+ T-lymphocyte count of 100/mm 3 (N > 500) and plasma HIV viral load of 100,000 copies/mL. HIV genotyping shows a mutation consistent with zidovudine resistance. This mutation is most likely in which of the following viral genes? A) DNA polymerase B) Glycoprotein 41 C) Glycoprotein 120 D) Integrase E) Protease F) Reverse transcriptase G) Thymidine kinase A 29-year-old woman is brought to the emergency department 1 hour after being injured in a motor vehicle collision. Abdominal examination shows tenderness with rebound. Vital signs are stable. A CT scan of the abdomen shows no abnormalities except for a small amount of intraperitoneal fluid. After 6 hours of observation, an exploratory laparotomy is done because of continuing severe abdominal pain No abnormalities are seen until the surgeon gently slides his hand behind the liver; there is a sudden massive hemorrhage from the region of the hand, and the patient's blood pressure becomes undetectable within 1 minute Which of the following underlying lesions is most likely associated with the hemorrhage? A) Avulsion of celiac trunk from the aorta B) Avulsion of hepatic veins from the inferior vena cava C) Traumatic transection of the aorta D) Traumatic transection of the hepatic artery E) Traumatic transection of the portal vein A 26-year - old woman develops hypotension and hemoglobinuria after receiving 1 unit of packed red blood cells. Which of the following are most likely to be involved in her condition? A) Antibody, complement C5-9 B) Circulating immune complexes, complement C5a, neutrophils C) Cytotoxic T lymphocytes D) IgE, mast cells , histamine, cytokines E) Lymphocytes, cytokines, macrophages A 74 - year - old man with emphysema and lung cancer is brought to the clinic by a social worker because of his wasted appearance. His wife of 50 years died 8 months ago He is impoverished, and his diet consists primarily of cereal and toast. He has lost 13.6 kg (30 lb) in the past 6 months. He has temporal muscle wasting , sunken eyes , loose skin , and edema of the lower extremities. He appears despondent and withdrawn. Serum albumin concentration is 2.5 g/dL. An x-ray of the chest shows a large mass in the hilum of the right lung. Which of the following best explains the edema? A) Anabolic state B) Glycogen depletion C) Lipolysis D) Negative nitrogen balance E) Starvation ketosis A 22-year - old woman who is at 16 weeks' gestation has decreased serum concentrations of a-fetoprotein and unconjugated estriol and an increased serum concentration of human chorionic gonadotropin. Which of the following disorders affecting the fetus is most likely? A) Angelman syndrome B) Beckwith-Wiedemann syndrome C) Down syndrome D) Fragile X syndrome E) Myotonic dystrophy F) Prader-Willi syndrome A 50-year - old man comes to the physician 3 days after his first generalized tonic-clonic seizure. He has a 1-month history of frequent episodes of a pins-and-needles sensation around the mouth and in the hands and feet. He also has had occasional episodes of involuntary contraction of the muscles of the hands or feet leading to wrist flexion or foot plantar flexion. His pulse is 80/min, and blood pressure is 150/ 90 mm Hg Neurologic examination shows mild, diffuse hyperreflexia. An abnormality of which of the following serum electrolyte concentrations is the most likely explanation for his symptoms? A) Bicarbonate B) Calcium C) Chloride D) Potassium E) Sodium A 50-year - old man who has smoked 2 packs of cigarettes a day for 34 years has experienced gradually increasing shortness of breath on exertion , chronic cough productive of thick sputum, and frequent episodes of wheezing The anteroposterior diameter of his chest is increased Diminished breath sounds and scattered rhonchi are audible throughout the lung fields. Which of the following laboratory abnormalities is expected? A) Decreased blood Pco 2 B) Increased blood HC03- C) Increased blood pH D) Increased urinary excretion of HC03- E) Increased urinary pH  I severe ankle injury. Physical examination shows weak extension or m< nerve injury at which of the following labeled locations in the diagram? An unimmunized 1-year -old boy is admitted to the hospital because of fever, irritability, and a stiff neck. Cultures of the nasopharynx and cerebrospinal fluid grow gram-negative coccobacilli. Electron microscopic examination shows the presence of pili on the bacteria recovered from the nasopharynx, but absence of pili on the bacteria of the same species recovered from the cerebrospinal fluid Which of the following processes shuts off expression of pili in this bacterium following invasion? A) Horizontal gene transfer B) Phase variation C) Plasmid acquisition D) Point mutation E) Transposon mutagenesis A previously healthy 7-year -old girl is brought to the physician by her parents because of a 1 -month history of excessive urination; she also has had a 2.3-kg (5-lb) weight loss during this period. Her pulse is 110/min , and blood pressure is 92/58 mm Hg. Physical examination shows poor skin turgor and a fruity odor on her breath. Her blood glucose concentration is 612 mg/dL. Laboratory studies are most likely to show an increase in which of the following? A) Arterial pH B) Serum bicarbonate concentration C) Serum chloride concentration D) Serum potassium concentration E) Serum sodium concentration A previously healthy 12-year -old boy is brought to the emergency department because of a 6-hour history of severe diarrhea. His temperature is 37.0° C (98.6°F), pulse is 100/min, respirations are 16/min, and blood pressure is 110/70 mm Hg. He appears markedly dehydrated. Physical examination shows no other abnormalities. The most appropriate treatment for this patient is an oral rehydration solution containing which of the following sets of ingredients? A) Bicarbonate and potassium B) Bicarbonate and sodium C) Glucose and insulin D) Glucose and sodium E) Lactate and bicarbonate F) Lactate and potassium A 4-month-old boy is brought to the office by his parents because of his small size, and difficulty feeding from a bottle. His mother states that he was recently adopted from a developing country, and his medical history is unknown. His vital signs are within normal limits. He is at the 10th percentile for weight and 40th percentile for length. Physical examination shows the findings in the photograph. The most likely cause of the facial finding involving the lip in this patient is a failure of normal fusion of which of the following pairs of structures? A) Lateral nasal and mandibular prominences B) Lateral nasal and maxillary prominences C) Lateral nasal and medial nasal prominences D) Mandibular and maxillary prominences E) Mandibular and medial nasal prominences F) Maxillary and medial nasal prominences A 24-year - old woman, gravida 1, para 1, comes to the physician because of nervousness and tremor since delivering a healthy female newborn 6 weeks ago. She also has had a 5- kg ( 11-lb) weight loss during this period. She has a history of panic disorder and carpal tunnel syndrome. Her temperature is 37°C ( 98.6°F), pulse is 100/min, and blood pressure is , 140/80 mm Hg. Physical examination shows a firm thyroid gland that is twice the normal size. Serum studies show a free thyroxine (FT, ) concentration of 2.4 ng/dL (N=0.8-2.4), thyroid-stimulating hormone concentration of less than 0.03 pU/ mL, and 24-hour thyroid radioactive iodine uptake of 1% (N=8-25%). Which of the following is the most likely explanation for this patient's symptoms? A) Anaplastic thyroid carcinoma B) Hypothyroidism C) Release of stored thyroid hormone from a thyroid gland infiltrated by lymphocytes D) Release of thyroid hormone from a lymphomatous thyroid gland E) Release of thyroid hormone from a thyroid gland stimulated by antibodies !. A 10-year - old girl has a slightly painful 2-mm subcutaneous nodule on her chin. Ten weeks ago, she required sutures after she | 4 lacerated her chin playing basketball. A photomicrograph of tissue obtained on biopsy of the nodule is shown. Which of the '. * n. *> * 8 following best describes the pathologic features? / m V i , >; % 1 vI , A) B) Amyloid Granulation tissue t / C) Granuloma ) D) Lymphocytic infiltrate E) Neutrophilic infiltrate A 5-year-old boy with mental retardation is grossly obese and has facial features of Prader-Willi syndrome (PWS). Karyotyping and fluorescent in situ hybridization studies do not show deletion in the usual site on chromosome 15. Which of the following findings is most likely to confirm PWS in this child? A) Deletion in the short arm of chromosome 15 B) Duplication within chromosome 15 C) Large trinucleotide repeat expansion in the PWS area of chromosome 15 D) Maternal origin of both chromosomes 15 E) Translocation in the short arm of chromosome 15 A 45-year- old man who is HIV positive comes to the physician because of a 1-week history of headaches and blurred vision. A lumbar puncture is done. Laboratory studies show: Serum glucose 95 mg/dL Cerebrospinal fluid Appearance cloudy, straw-colored Leukocyte count 400/mm 3 (100% lymphocytes) Erythrocyte count 50/mm 3 Glucose concentration 30 mg/dL Total protein concentration 68 mg/dL Fungal stain positive for yeast The most appropriate treatment for this patient is a drug with which of the following mechanisms of action? A) Antagonism of murein hydrolase B) Blockade of microtubule polymerization C) Disruption of the pathogen cell membrane D) Induction of cytochrome P450 enzymes E) Inhibition of pathogen cell wall synthesis In patients with adenosine deaminase deficiency, there is a 50- to 100- fold increase in dATP concentration in T lymphocytes. This increase in dATP inhibits which of the following enzymes , thus compromising DNA synthesis? A) DNA ligase B) DNA polymerase I C) Nucleoside monophosphate kinase D) Ribonucleotide reductase E) Thymidylate synthase Patients with mucolipidosis II (l-cell disease) lack the phosphotransferase required for the formation of mannose 6-phosphate residues that are normally attached to enzymes destined for the lysosome. The mannose 6-phosphate sorting signal is normally added to proteins in the c/s-Golgi. Which of the following most likely occurs to the lysosomal enzymes in these patients? A) Degraded in the lysosome B) Imported into the nucleus C) Retained in the rough endoplasmic reticulum D) Secreted from the cells E) Sorted into the mitochondria A 37-year - old man comes to the physician for a follow -up examination. He has a 1-year history of hypertension. Despite aggressive pharmacotherapy, his blood pressure has averaged 188/131 mm Hg. His blood pressure today is 190/135 mm Hg Funduscopic examination shows multiple flame hemorrhages with severe arteriolar narrowing. Which of the following disorders of blood vessels is most likely to be caused by this condition? A) Berry aneurysm B) Fusiform aneurysm C) Hyperplastic arteriolosclerosis D) Medial arterial calcification (Monckeberg arteriosclerosis ) E) Temporal arteritis A case-control study is conducted to assess the relationship between exposure to environmental tobacco smoke and sinusitis. The table shows the results of the study Cases Controls Exposed to smoke 20 25 Not exposed to smoke 5 100 Which of the following is the prevalence of sinusitis in the general population? A) 16% B) 40% C) 50% D) 80% E) Cannot be determined from the data given A 52-year - old man with metastatic oat cell carcinoma begins to receive hospice care. Treatment with narcotic medication is initiated for severe bone pain. Which of the following actions by the physician regarding this treatment is most appropriate? A) Begin with minimal amounts of pain medication to monitor any adverse effects B) Carefully monitor the administration of this pain medication to avoid patient addiction C) Ensure that the patient receives enough medication to control his pain D) Make sure that the patient does not have direct access to the pain medication to avoid intentional overdose E) Regularly assess the patient for respiratory depression due to the pain medication A healthy 25-year - old man eats a meal consisting of 60% carbohydrates, 30% fat, and 10% protein. His serum insulin concentration is increased after the meal. Which of the following is the most likely mechanism of pancreatic secretion of insulin in this man? A) Diffusion of insulin across the plasma membrane by an increase in intracellular bicarbonate concentration B) Diffusion of insulin across the plasma membrane through a glucose transporter C) Diffusion of insulin across the plasma membrane through a protein transporter D) Enzymatic hydrolysis of the plasma membrane E) Fusion of an intracellular vesicle with the plasma membrane i. A 60-year -old man comes to the physician because of progressive shortness of breath during the past 3 months. He states that for many years he has worked in a shipyard. His respirations are 25/min. Bilateral basilar crepitant crackles are heard. An x-ray of the chest shows reticulonodular pulmonary infiltrates consistent with interstitial fibrosis. Microscopic examination of sputum shows occasional elongate structures as shown. The fibrosis was most likely initiated by interaction of these structures with which of the following cell types? A) Alveolar capillary endothelial cell O F) Goblet cell B) Alveolar macrophage G G) Kulchitsky cell C) Chondrocyte O H) Squamous epithelial cell D) Ciliated columnar epithelial cell O I) Type I pneumocyte E) Clara cell G J) Type II pneumocyte A 65-year - old woman with a 20- year history of osteoarthritis of the hands now has pain radiating down the distal anterior thigh, knee, medial leg , and foot. Bony outgrowth of vertebrae compressing one of the spinal nerves is suspected. Compression of a nerve root in which of the following intervertebral foramina is the most likely cause of her symptoms? A) T-10 to 11 B) L-1 to 2 C) L-3 to 4 D) S-1 to 2 E) S-4 to 5  - A 15 year- old girl is brought to the physician by her mother because of a 1-day history of redness and painful skin following sunbathing. She reports that she used sunblock every few hours. She takes no medications Physical examination shows severe erythema of the back and extremities. There are no blisters Which of the following best describes her condition? A) Allergic reaction to the sun B) First-degree burn C) Rhus dermatitis D) Second-degree burn E) Third-degree burn A 48-year-old man begins furosemide therapy for pedal edema associated with biventricular failure and hypertension Five days later, the edema is not fully resolved, and his serum potassium concentration has decreased from 4.2 mEq/L to 3 mEq/L. A drug with which of the following actions should be added to this patient's medication regimen? A) Blocks basolateral K + channels in the collecting duct B) Decreases the luminal permeability to Na + in the collecting duct C) Increases the delivery of Na + and K + to the collecting duct D) Increases the negative charge of the luminal tubule fluid E) Stimulates Na +-K + ATPase in the collecting duct A 10-month-old girl is brought to the emergency department because she is pale and unresponsive. Her mother has given her 3 adult doses of loperamide over the past 6 hours for diarrhea. Her pulse is 120/min and respirations are 10/min. Examination shows marked abdominal distention. If medication is required , which of the following is the most appropriate therapy? A) Bethanechol B) Diphenhydramine C) Epinephrine D) Naloxone E) Physostigmine A 28-year -old woman is brought to the physician because of a 3-week history of double vision. One year ago, she had an episode of blurry vision in her left eye that gradually improved during the next 2 months without treatment Neurologic examination shows that the right eye does not adduct past the midline on horizontal gaze when looking to the left When convergence is tested , the right eye is able to adduct past the midline. Rightward horizontal gaze is normal. This patient most likely has a lesion involving which of the following labeled structures in the photograph of the brain stem shown? A 9-year-old boy is brought to the physician by his mother because of a 1-year history of cough productive of mucoid sputum, wheezing , and shortness of breath with exertion He has a history of recurrent upper respiratory tract and sinus infections since birth. He is at the 25th percentile for height and weight. The mother says that his younger sibling is beginning to develop similar problems. Physical examination shows mild clubbing of the fingers Laboratory studies show markedly increased sweat chloride and sodium concentrations. A defect of which of the following in this patient's bronchial epithelium is most likely causing these symptoms? A) Adrenoreceptors B) Membrane receptors C) Nuclear receptors D) Protein regulation E) Protein structure A 25-year - old woman is admitted to the hospital because of septic shock She underwent splenectomy 6 months ago after she sustained traumatic injury during a motor vehicle collision. Her temperature is 39 4°C (103'F), and blood pressure is 80/40 mm Hg Coarse tubular breath sounds are heard bilaterally, and egophony is heard at the right base. A chest x-ray shows bilateral pulmonary opacities, dense consolidation at the base of the right lung , and a possible right- sided effusion. Which of the following is the most likely causal organism? A) Actinomyces israelii B) Bacillus anthracis C) Klebsiella pneumoniae D) Pseudomonas aeruginosa E) Streptococcus pneumoniae fhrou l A) 10^ h e r a t e (i n Umin) mrough the aneurysm. The estimated cross-sectional area of the aneurysm is 2 cm 2 and the mean velocity of blood flow B) 2.4 C) 3.2 D) 3.6 E) 4.0 A 66-year -old man develops worsening shortness of breath and swelling of the legs. He had a myocardial infarction 6 months ago. Pulse is 120/min, and blood pressure is 135/ 82 mm Hg Examination shows distended jugular veins, bilateral crackles, and pitting edema in the lower extremities. Serum sodium concentration is 129 mEq/L. Which of the following is most likely responsible for the hyponatremia in this patient? A) Dilution of serum sodium due to ADH (vasopressin) secretion B) Increased urinary sodium excretion due to renal tubular dysfunction C) Increased urinary sodium excretion due to secretion of aldosterone D) Increased urinary sodium excretion due to secretion of atrial natriuretic peptide E) Restriction of dietary sodium intake ). A 30-year- old man comes to the physician because of a 2-day history of blood in his urine, dull flank pain, and voiding large amounts of urine. The patient states that his father died of an unknown kidney disease. His blood pressure is 150/100 mm Hg. Physical examination shows bilateral renal masses. Laboratory studies show proteinuria and gross hematuria A CT scan of the abdomen shows cystic masses in each of the kidneys; the right mass is larger than the left. A right nephrectomy is done; the surgical specimen is shown. The underlying defect most likely involves which of the following molecules? A) Desmocollin-1a B) E-cadherin C) Laminin receptor D) P-selectin E) Polycystin A 60-year - old woman comes to the physician because of a 2-month history of shortness of breath and cough and a 2-week history of progressive swelling of her face. The cough is productive of approximately V cup of mildly blood-tinged, white-to-yellow sputum daily. She has had a 2.3-kg (5-lb) weight loss over the past 4 months. She has a 15-year history of *. She has smoked 1 pack of cigarettes daily for 45 years. Her pulse is 90/min and regular, respirations are 20/min , and blood pressure is 135/90 hypertension treated with enalapril mm Hg. Physical examination shows edema of the face and neck and jugular venous distention. Breath sounds are mildly decreased throughout all lung fields, and there are no cardiac murmurs. Her serum sodium concentration is 125 mEq/ L. Which of the following is the most likely underlying cause of this patient's facial edema ? A) Angioedema B) Hyperthyroidism C) Hyponatremia D) Hypoparathyroidism E) Lung cancer A 57-year - old woman comes to the physician because of episodes of burning, shock-like pain on the left side of her face during the past 4 months. She has several episodes each day. usually caused by chewing. The pain lasts from 5 to 10 seconds. Neurologic examination shows no abnormalities. Which of the following is the most likely diagnosis? A) Cluster headache B) Migraine C) Multiple sclerosis D) Temporal arteritis E) Trigeminal neuralgia A 42-year -old man comes to the physician because of a 1-month history of fatigue, excessive thirst , and frequent urination with large volume. He is 178 cm (5 ft 10 in) tall and weighs 61 kg (135 lb); BMI is 19 kg/ m 2. His pulse is 96/min, and blood pressure is 104/60 mm Hg. Physical examination shows dehydration. Fasting laboratory studies show: Serum Glucose normal ADH (vasopressin) increased Osmolality increased Urine osmolality decreased In addition to a low- sodium diet, which of the following drugs is the most appropriate treatment for this patient? A) Acetazolamide B) Desmopressin C) Furosemide D) Hydrochlorothiazide E) Spironolactone A 1-year- old boy is found to have an impairment of the respiratory burst of phagocytes. He has a family history of immunodeficiency. This patient is at greatest risk for infection caused by which of the following organisms? A) Enterococcus faecium B) Escherichia coli C) Haemophilus influenzae D) Staphylococcus aureus E) Streptococcus pneumoniae F) Streptococcus pyogenes (group A) A 13-year - old girl is brought to the physician by her mother for a routine well-child examination. Neither the child nor the mother has any particular health concerns. The patient is doing well in school and participates in soccer and lacrosse in a local recreation league The physician wants to ask the patient about sexuality and sexual activity. Which of the following actions by the physician is most appropriate? A) Ask the mother to leave the room before asking the patient any questions B) Ask the patient to leave the room and then ask the mother about her daughter C) Ask the questions with both the mother and the patient present D) Give the patient a questionnaire that she can fill out at home E) Tell the patient that some sensitive questions are next and that only she can ask her mother to leave the room i. A 28-year-old man comes to the emergency department because of a 6-hour history of cramping and severe left midabdominal pain He had a single episode of vomiting. His temperature is 37°C (98.6°F). Abdominal examination shows a mass in the midabdomen. A CT scan of the abdomen with contrast is shown ; the abnormality is indicated by the arrows Intussusception of which of the following portions of the intestinal tract is the most likely cause of this patient’s pain? A) Appendix B) Cecum C) Duodenum D) Jejunum E) Stomach An Rh- negative woman, gravida 3, para 2, has had an increasing bilirubin concentration in amniotic fluid obtained between 22 and 29 weeks' gestation. Umbilical cord blood obtained at 29 weeks' gestation had a hematocrit of 6.2%. Transfusion of which of the following types of packed red cells to the fetus in utero should be used to correct the anemia'? A) A, Rh-negative B) A, Rh-positive C) AB , Rh-negative D) AB, Rh-positive E) B, Rh-negative F) B, Rh-positive G) O, Rh-negative H) O, Rh-positive A 35-year - old woman has weakness and fever When she was 25 years old, she was treated for Hodgkin disease with mechlorethamine, oncovin, procarbazine, and prednisone. She has had a splenectomy There is no evidence of lymphadenopathy. A peripheral blood smear shows numerous blast forms. Which of the following is the most likely explanation for these findings? A) Acute lymphocytic leukemia B) Acute myelocytic leukemia C) Chronic lymphocytic leukemia D) Lymphoma E) Recurrence of Hodgkin disease During an experiment , a 22-year-old man receives an infusion of histamine in his left brachial artery. Which of the following sets of microcirculatory changes will most likely occur in his left arm? Arteriolar Resistance Capillary Hydrostatic Pressure Capillary Filtration Rate A) B) C) T i D) T t E) i i F) i T G) i i H) i t A 25 - year -old woman comes to the physician because of easy bruising and bleeding from her gums over the past 2 days. She has been otherwise healthy and has never had abnormal bleeding. Laboratory studies show: Hemoglobin 13.2 g /dL Hematocrit 39.6% Leukocyte count 7000/mm 3 Platelet count 6000/mm 3 Prothrombin time 14 sec (INR=1.2) Partial thromboplastin time 30 sec Which of the following is the most likely cause of these findings? A) Disseminated intravascular coagulation B) Hypersplenism C) Immune thrombocytopenic purpura D) Iron deficiency E) Vitamin C deficiency F) von Willebrand disease An 11-year-old boy has had pain in his right mid-thigh for 2 weeks. Physical examination shows an area of warmth and tenderness around an ill-defined mass. X-ray of the femur shows a solitary mid-diaphyseal osteolytic lesion with permeative margins. The lesion is surrounded by concentric layers of reactive bone. Tissue obtained on biopsy of the mass is composed of poorly differentiated sheets of small, uniform, hyperchromatic cells with a very high nuclearcytoplasmic ratio, scant stroma, and no visible matrix. Which of the following is the most likely diagnosis? A) Chondrosarcoma B) Eosinophilic granuloma C) Ewing sarcoma D) Multiple myeloma E) Nephroblastoma (Wilms tumor) F) Osteosarcoma G) Small lymphocytic lymphoma A 35-year - old man with bronchial asthma starts taking albuterol Which of the following changes in second messenger levels is most likely in the cells affected by this treatment? A) Decrease in cAMP B) Decrease in cGMP C) Decrease in inositol 1, 4, 5-trisphosphate D) Increase in cAMP E) Increase in cGMP F) Increase in inositol 1,4,5-trisphosphate A 57- year - old woman comes to the physician 2 weeks after finding a lump in her left breast on self -examination Physical examination shows a 2-cm mass in the upper inner quadrant of the left breast. Carcinoma is suspected. X-rays show multiple lesions in the vertebral column, and metastatic disease is suspected. Which of the following veins draining the breast provides the most direct pathway for malignant cells to travel to the vertebral column? A) Axillary B) Cephalic C) Intercostal D) Internal thoracic (mammary) E) Lateral thoracic A 10-year - old boy receives a renal transplant from a living , related donor for cystic renal dysplasia. Three months later , there is tenderness at the site of the graft , and serum creatinine concentration increases from 1.0 to 2.0 mg/dL. Which of the following findings on renal biopsy is most likely to confirm a diagnosis of rejection? A) Arteriolar C 3 deposition B) Dilation of Bowman space C) Fibrous scars with plasma cells D) Glomerular neutrophils and necrosis E) Lymphocytes infiltrating tubular epithelium F) Red blood cell casts G) Subcortical necrosis An 18-year-old man comes to the physician 10 days after injuring his right hand during a game of tag football. He says that he was attempting to tag an opposing player when he inadvertently caught the tip of his ring finger on the other player's jersey. He felt a popping sensation at the tip of his finger and then immediately felt sharp pain localized to the finger. He noticed swelling of the finger several minutes later. Examination of the right hand shows mild tenderness over the palmar tip of the ring finger. He is unable to flex the distal interphalangeal joint of the right ring finger, but he is able to flex the metacarpophalangeal and proximal interphalangeal joints. This patient most likely injured a tendon whose muscle is supplied by fibers from which of the following nerve roots? A) C3 B) C4 C) C5 D) C6 E) C7 F) C8 A 35 - year - old man comes to the physician because of a 6-week history of pain in his right arm and tingling sensation in the fingers of his right hand Physical examination shows weakness of extension and pronation of the right forearm. The triceps muscle stretch reflex is decreased Which of the following nervous structures is most likely involved? A) C6 nerve root B) C7 nerve root C) C8 nerve root D) Median nerve E) Radial nerve A 27-year -old woman comes to the physician because of swelling in her left arm that began 10 days after a spontaneous abortion in the middle of her second trimester. A radiocontrast study shows axillary vein thrombosis. Laboratory studies show: Bleeding time normal Prothrombin time increased Partial thromboplastin time increased Thrombin time normal Which of the following is the most likely cause of this woman's condition? A) Antiphospholipid antibodies B) Antithrombin deficiency C) Dysfibrinogenemia D) Protein C deficiency E) Protein S deficiency The risk for hemorrhagic stroke from drug X is investigated by utilizing a questionnaire about drug use in 702 patients with hemorrhagic stroke and in 1376 control subjects contacted by random-digit dialing. Which of the following best describes this study design? A) Case-control study B) Cohort study C) Cross-sectional survey D) Randomized, double-blind experiment E) Randomized, single-blind experiment. A 4-year-old boy is brought to the physician by his parents because he has had two bacterial urinary tract infections during the past year. Physical examination shows no abnormalities Radiologic studies of the urinary tract show marked dilation of the left ureter and renal pelvis, and minimal left-sided renal function. A left nephrectomy is performed. A photograph of the resected specimen is shown. Microscopic examination of the renal parenchyma is most likely to show which of the following? A) Amyloidosis B) Interstitial inflammation C) Membranous glomerulonephritis D) Nephroblastomatosis E) Renal cell carcinoma Which of the following is required for the synthesis of glucosamine from fructose 6-phosphate? A) Arginine B) ATP C) Carbamoyl phosphate D) Glutamine E) A/-acetylglutamate A 25- year-old woman comes to the physician because of a 6-month history of irregular menstrual periods and progressive acne. Menses have occurred at irregular 25- to 42-day intervals. She is 170 cm (5 ft 7 in) tall and weighs 100 kg (220 lb); BMI is 35 kg/m 2. Her voice is deep Physical examination shows dark hair over the upper lip and chin, and open and closed comedones over the face, chest, and back. Serum studies are most likely to show which of the following in this patient? Fasting Luteinizing Insulin Testosterone Hormone A) Increased increased increased B) Increased increased decreased C) Increased decreased increased D) Decreased increased increased E) Decreased increased decreased F) Decreased decreased decreased A 56- year -old woman is brought to the emergency department by her husband because she has had headache , confusion, and difficulty speaking and walking for the past 2 days Mental status shows confusion and memory loss Her temperature is 38.9°C (102°F). Brudzinski and Kernig signs are absent. Analysis of cerebrospinal fluid shows: Opening pressure 260 mm Hp Leukocyte count (mostly lymphocytes) 208/mm 3 Protein 52 mg/dL Glucose 40 mg/dL An EEG shows abnormalities in the right temporal lobe and periodic lateralized epileptiform discharges. Which of the following is the most likely diagnosis? A) Aseptic meningitis B) Bacterial encephalitis C) Herpes encephalitis D) Neurosarcoidosis E) Tuberculous meningitis A 66-vear - old man comes to the physician because of a 2-month history of the inability to maintain an erection He also has had fatigue and difficulty sleeping and concentrating during this period. Three months ago , he had a cerebral infarction with right hemiparesis that has gradually resolved. Physical examination shows no abnormalities. Which of the following additional pairs of findings in this patient is most likely on history taking? Libido Nocturnal Erections A) Normal normal B) Normal decreased C) Decreased normal D) Decreased decreased A 52-year -old man is brought to the emergency department 1 hour after he was found next to a faulty space heater He is confused. Physical examination shows reddish-tinged skin Arterial blood gas analysis on room air shows a Po 2 within the reference range and carboxyhemoglobin concentration of 40% (N=2%). He is intubated and mechanically ventilated with supplemental oxygen. Assuming no further carbon monoxide (CO) exposure, which of the following is the best estimate for the time it will take for the removal of all the CO-carrying erythrocytes from this patient's circulation? A) 1 Day B) 2 Weeks C) 1 Month D) 4 Months E) 1 Year A randomized controlled trial is conducted to assess the effect of diuretic therapy on the risk for cerebral infarction in patients with systolic hypertension. A total of 4736 patients with systolic blood pressure measurements greater than 140 mm Hg and diastolic blood pressure measurements ranging from 50 mm Hg to 85 mm Hg are randomly assigned to receive diuretic therapy or placebo. After 5 years, results show: Cerebral Infarction Yes No Total Diuretic Therapy 123 2242 2365 Placebo 194 2177 2371 Total 317 4419 4736 Which of the following best represents the absolute risk reduction for cerebral infarction in patients receiving diuretic therapy? A) (194/2177) - (123/2242) B) (194/2371) - (123/2365) C) (123/2242) / (194/2177) D) (123/2365) / (194/2371) E) (194/2177) / (123/2242) F) (194/2371) / (123/2365) A newborn has cyanosis, tachypnea , and retractions of the muscles of the chest wall during inspiration. She weighs 2500 g (5 lb 8 oz). Arterial blood gas values while she breathes room air are: pH 7.04 Pco 2 65 mm Hg Po 2 35 mm Hg HCO 3- 15 mEq/L Which of the following best describes her acid-base balance? A) Metabolic acidosis, uncompensated B) Metabolic alkalosis, uncompensated C) Respiratory acidosis , uncompensated D) Respiratory alkalosis, uncompensated E) Respiratory acidosis and metabolic acidosis F) Respiratory acidosis and metabolic alkalosis A 42-year-old woman with frequent heartburn has relief of symptoms with ranitidine treatment. The therapeutic effect of ranitidine is most likely mediated by a receptor whose activation increases which of the following in the parietal cells of the stomach? A) Calcium B) cAMP C) cGMP D) Gastrin E) Prostaglandin E, A physician is unable to communicate "bad news" to a patient because the patient reminds him of his older brother who always intimidated him. Which of the following terms best describes this reaction? A) Conversion B) Countertransference C) Regression D) Splitting E) Sublimation A 54 -year -old man who works in a delicatessen comes to the physician because of decreased sensation of the tip of his right index finger. Six months ago, he severed this finger while slicing meat and it was successfully reattached by prompt surgical repair. Examination of the finger shows muscle wasting. Which of the following cells is most likely blocking reinnervation of the muscles of this patient's finger? A) Fibrous astrocytes B) Microglial cells C) Oligodendrocytes D) Satellite cells E) Schwann cells  A previously healthy 28-year -old man comes to the physician's office because of severe abdominal pain accompanied by nausea, vomiting, and blood in the urine. Temperature is 36.7 C (98.1 F), pulse is 100/min, respirations are 20/min, and blood pressure is 140/90 mm Hg. The patient appears to be in distress and occasionally writhes in pain. Abdominal examination shows a flat abdomen with hypoactive bowel sounds. There is mild tenderness on palpation of the right middle and right lower quadrant of the abdomen and the right flank; there is no rebound or guarding. The testes are normal, and no hernia is palpable Which of the following is the most likely diagnosis? A) Acute cortical necrosis B) Acute papillary necrosis C) Acute tubular necrosis D) Cystitis E) Glomerulonephritis F) Hypernephroma G) Interstitial nephritis H) Nephrolithiasis I) Pyelonephritis A 29-year - old woman comes to the physician because of a 5-week history of fatigue and a 4-day history of heart palpitations and anxiety. She has primary hypothyroidism treated with triiodothyronine She says that she has doubled the dose of the medication over the past week because of fatigue. Her pulse is 112/min, and blood pressure is 126/70 mm Hg Physical examination shows a fine motor tremor of the hands. Deep tendon reflexes are brisk. Thyroid function testing is most likely to show which of the following sets of serum concentrations? Thyroid- stimulating Free Free Hormone Thyroxine Triiodothyronine A) Increased increased increased B) Increased increased decreased C) Increased decreased increased D) Decreased increased increased E) Decreased increased decreased F) Decreased decreased increased An 81-year -old man comes to the physician for ongoing management of hypertension of 20 years' duration. His temperature is 36.8°C (98.2°F), pulse is 80/min, respirations are 20/min, and blood pressure is 200/110 mm Hg. To reconfirm the patient's blood pressure, the physician places his index finger over the radial artery while inflating the sphygmomanometer cuff to just above the previously measured systolic blood pressure level At this point, the radial artery becomes nonpulsatile but remains easily palpable even as the cuff is further inflated Which of the following best explains this phenomenon? A) Atherosclerosis B) Connective tissue disease C) Left ventricular hypertrophy D) Thrombosis E) Vasculitis  4 A previously healthy 45-year-old woman has had fever, confusion , and decreased urine production for the past 2 days. Her temperature is O 38.3°C (101°F). Laboratory studies show : oe. Hemoglobin 9 g/dL Hematocrit 27% 0 Leukocyte count 10,500/ mm 3 v V Neutrophils 65% © Lymphocytes Monocytes 25% 8% '6 >/ < Eosinophils 2% Q Reticulocyte count Mean corpuscular volume 8% 95 pm 3 n o©