Form 20 Questions/Concepts
A 24 year old man comes to the physician 8 hours after the onset of severe pain of his lower back that radiates down his left leg. He started a weight-lifting regimen earlier in the day during which he tried to lift a bar loaded with 200lb from the group to over his head. The pain began almost immediately after this attempt. What is the most likely cause of this patient's pain?
Rupture of an intervertebral disc
A 55 year old man with DM2, HTN, and hyperlipidemia develops severe myalgias with weakness. Serum creatinine kinase activity is increased, and urine is positive for myoglobin. What drug is most likely responsible for these symptoms?
Statins
A 61-year-old man has erectile dysfunction due to spinal cord injury at L-2. Sildenafil is likely to markedly correct the dysfunction by acting at which of the following labeled structures in the penis?
Structure D
A 19 year old man who is a college student is brought to the ER because of sudden onset of right sided chest pain and difficulty breathing after an accident in which he was thrown from his bicycle. He has difficulty walking and cannot climb stairs because of pain and SOB. He is slightly cyanotic, afebrile, and tachypneic. What is most suggestive that fractured ribs caused the respiratory problem?
Subcutaneous crepitus
A 4 week old infant is brought to the emergency department because he has vomited after every feeding for the past 2 days. The most recent episode of vomiting was very forceful, with regurgitation through the nostrils. Physical examination shows mild abdominal distention with visible peristalsis. Which of the following is the most likely explanation for these findings?
hypertrophic pyloric stenosis
What is most likely to decrease the likelihood of making a beta error?
increase the sample size
A patient takes methanol. Now their pupils are dilated with a diminished pupillary reflex. The most likely cause of this patient's visual symptoms is an excess of what metabolite?
formic acid
A biopsy of a lymph node that has been infected with bartonella henselae from a kitten will show what histologic pattern?
granulomas containing stellate microabscesses
A 31 year old man has a large, yellow, soft mass deeply infiltrating the gluteus maximus muscle. Microscopic examination of the excised mass shows irregular vacuolated cells and clear cells with frequent mitoses. What is the most likely diagnosis?
liposarcoma
What organ is the most likely site of C-reactive protein biosynthesis?
liver
red ragged fibers
mitochondrial diseases
Genetic testing shows a mutation in the CBFA1 gene. What cell type is directly affected by the mutation?
osteoblasts
An 80-year-old man with DM2 is brought to the physician because of a 2 month history of severe constipation. Use of over-the-counter laxatives has not relieved his symptoms. Abdominal examination shows distension. Colonoscopy shows no abnormalities. This patient most likely has dysfunction in what nerves?
pelvic splanchnic
What procedure during an operation is most likely to produce an iatrogenic chylothorax?
placement of the central line via the left internal jugular vein
A 72-year-old woman with dysphagia is undergoing surgical evaluation of a mass in the posterior mediastinum. During this procedure, the thoracic duct is inadvertently damaged near the mass. This injury is most likely to impair the normal lymphatic return of what structure?
right kidney
A 62-year-old man with alcohol-induced liver disease develops massive ascites. Infection is ruled out. The most appropriate diuretic treatment, in addition to loop diuretics, includes what drug?
spironolactone
The short gastric arteries branch from what arteries?
splenic
A 23-year-old man has had fever, hypotension, and DIC for 24 hours. She has a history of splenectomy following trauma. Which of the following bacteria is the most likely cause of this overwhelming sepsis?
strep. pneumo
A 60 year old woman has prolonged apnea following general anesthesia. Plasma cholinesterase activity is abnormal. Which of the following agents is most likely responsible for the prolonged apnea in this patient?
succinylcholine
The antibody in preparation for inflammatory bowel disease is most likely to be directed against what component?
tumor necrosis factor
Statins are most likely to decrease a patient's serum cholesterol concentration by what mechanism?
upregulation of the LDL receptors
Monoclonality of neoplastic cells in endometrial carcinoma can be best determined by analysis of what?
x chromosome-linked isoenzymes
When intensive multidrug chemotherapy is planned, before treatment is initiated to decrease the patient's risk for kidney failure, it is most appropriate to administer a drug that inhibits what?
xanthine oxidase
A 32 year old woman has had fecal incontinence since giving birth to her first child 1 year ago. What is the most likely cause of the fecal incontinence in this patient?
Damage to the anal sphincter
A patient with a 1 week history of diarrhea has reduced tissue turgor. Arterial pH is .3; serum bicarbonate concentration is 15. This patient is also likely to have what?
Decreased arterial Pco2
A 13 year old girl has an episode of severe cellular rejection necessitating maximal immunosuppression 6 months after a cadaveric renal transplant. Two weeks later, she develops lymphadenopathy and hepatosplenomegaly. Examination of lymph node tissue obtained on biopsy shows a monomorphous population of B lymphocytes. What finding is most likely on further evaluation of these cells?
Epstein-Barr virus genome
A patient is at increased risk of a child with Down syndrome is she has which of the following sets of ultrasound and serum findings? Fetal ultrasound nuchal translucency Pregnancy associated plasma protein HCG
Fetal ultrasound nuchal translucency: increased Pregnancy associated plasma protein: decreased HCG: Increased
What is the reason for a decreased platelet count after administering heparin?
HIT Antiplatelet antibodies
What is a change in the cardiovascular system that occurs with normal aging?
Increased basal systolic blood pressure
A 37 year old nurse is accidentally stuck with a needle used to obtain blood from a patient who is HIV positive. Because of the severity of the exposure, she receives three antiretroviral agents. Four weeks later, she develops anemia and neutropenia. What best describes the MOA of these antiretroviral agents that is most likely responsible for the anemia and neutropenia?
Inhibits reverse transcriptase
What best describes the role of ethnicity when the appropriate medication is selected for a patient?
It should play a role because the efficacy of certain classes of medications varies among different ethnicities
An 18 year old boy has just been diagnosed with schizophrenia. His identical twin brother is unaffected, but he and his parents are concerned about his likelihood of developing the disorder. What represents the brother's risk for developing schizophrenia?
50%
A 35-year-old man comes to the physician to discuss donating a kidney to his 39 year old sister who has DM1 and chronic renal failure. HE has no history of major medical illness, and physical examination shows no abnormalities. What best describes the likelihood that this donor's human leukocyte antigen type will match that of this sister?
1:4
During an experiment, an investigator isolates an abnormal elastin with unusual instability from the connective tissue of mice. Analysis of the elastin shows a decreased number of desmosine cross-links. Upon amino acid analysis, the concentration of which of the following amino acids in the abnormal protein would be most likely different when compared with normal elastin?
Lysine
A 33 year old woman comes to the emergency department 1 hour after she slipped on an icy sidewalk and fell onto her outstretched hand. Physical exam shows swelling and tenderness to palpitation centrally of the palmar side of the right wrist. Palpation of the right anatomical snuffbox and the remaining portion of the wrist elicits no pain. The most likely cause of the findings in this patient is dislocation of which bone?
Lunate
A 25 year old woman comes to the physician because of a 2 day history of fever, malaise, and a rash. She had a single painless lesion on her labia 3 weeks ago, but it resolved spontaneously. She is sexually active, but she and her partner do not use condoms consistently. Her temp is 100.4 and physical exam shows a diffuse erythematous rash that includes the palms and soles. A sensitive but nonspecific rapid serologic screening test that uses what reagents is most likely to support a diagnosis?
A phosphlipid (cardiolipin) on charcoal particles
What is the mode of inheritance for hereditary spherocytosis? Defect?
AD (therefore patient will be heterozygous!) Defect: ankyrin, spectrin, or band 3 Spherocytes with loss of central pallor Increased RDW and increased MCHC Diagnosed via osmotic fragility test
A 70 year old woman is transferred to a rehab service 2 days after operative repair of a fracture of the right femus. She weights 143lbs. What is the most important predictor of success in the rehab of this patient
Activity level before the fracture
In accordance with intention to treat analysis, how should the data pertaining to all individuals who did not adhere to the instructions be treated?
Analyze all nonadherent participants according to the group of the study to which each was randomized
At a postnatal checkup, a 6 week old female newborn weighs 20 ounces less than at delivery. Her mother says she vomits and regurgitates bile tinged fluid after every feeding. What is the most likely cause of this abnormality?
Annular pancreas
What does LTB4 do?
Attracts and activates neutrophils
A 30 year old woman develops serum sickness following parental administration of penicillin. A plasma sample is found to contain a mediator that stimulates histamine release from mast cells. Which of the following mediators was most likely found in this patient's plasma?
C3a
A 77 year old woman has been having difficulty fastening buttons. She has weakness of the intrinsic muscles of the hands and loss of sensation in the little fingers. What is the most likely cause of these findings?
C7-T1 foraminal stenosis
An investigator is studying patients with West Nile virus infection. During a 5 year period, data are collected on 25 patients diagnosed with this condition as confirmed by testing at the CDC. Demographic information on the patients is reported as well as info about likely sources of infection. What best describes this study design?
Case series
A 55-year-old woman comes to the physician for a follow-up examination. She has a family history of skin cancer and rigorously avoids exposure to the sun. Her dietary intake of vit. D meets current recommendations. Physical examination shows no abnormalities. Serum studies show a decreased 25-hydroxycholecalciferol concentration. Decreased production of which of the following precursors in skin is most likely to occur in this patient?
Cholecalciferol
Drug that can be used to alter platelet function and providing direct arterial vasodilation Why would you use this drug?
Cilostazol Cilostazol is used to improve the symptoms of a certain blood flow problem in the legs (intermittent claudication). Cilostazol can decrease the muscle pain/cramps that occur during exercise/walking. Claudication pain is caused by too little oxygen getting to the muscles. Cilostazol can increase blood flow and the amount of oxygen that gets to the muscles
A 48 year old is brought to the ER 12 hours after taking a massive dose of ferrous sulfate. Serum sodium and potassium concentrations are within the reference range. Which of the set of serum concentrations is most consistent with this overdose Cl HCO3
Cl - 96 HCO3 - 8
An 8-year-old boy is evaluated for ventricular systolic overload. The standard-lead ECG shows severe left axis deviation of the main QRS vector (upward in lead I and downward in lead II) What is the most likely explanation for this patient's condition?
Coarctation of the aorta
A 55 year old man comes to the physician because of constipation since starting an OTC medication 2 weeks ago for a chronic cough and sinus congestion. What ingredient in the medication is the most likely cause of this patient's new syptoms?
Dextromethorphan
A 23 year old woman sustains significant blood loss in a MVC. She is given 3 units of blood and has an uneventful recovery. Four weeks later, she becomes jaundiced. She is afebrile. Laboratory evaluation shows anemia and reticulocytosis; there is no evidence of infection. Which additional study is likely to be most useful in establishing the diagnosis?
Direct antiglobulin test
A 16 year old student has uncontrollable sleepiness, falling asleep several times a day while sitting in class. The slightest noise or touch is enough to waken him. What most likely characterizes the onset of his sleep at night?
Direct transition from wakefulness to REM sleep
A 45 year old man has fever, chills, dysuria, and a tender, enlarged prostate. What is the most likely causal organism?
E. coli
A 10 year old boy has a palpable mass in the ventral midline of the neck just inferior to the hyoid bone. This structure most likely developed from what embryonic tissue?
Endoderm of foramen caecum
If amiodarone is administered, a patient is at greatest risk for what adverse effects?
Hypothyroidism
A 2 year old child undergoes resection of the right kidney because of chronic infections secondary to reflux. The left kidney is grossly normal. What structural adaptations will eventually occur in the left kidney?
Increase in glomerular size
A 3 month old boy is brought to the office by his mother because of a 1 week history of a lump on the right side of his groin. The mother says that when the patient cries, the bulge increases in size, and when he is quiet, it disappears. Physical examination of a soft mass in the right groin region that decreases easily. What best describes the relationship of the hernia sac?
Lateral to the inferior epigastric artery and superior to the inguinal ligament
A 35 year old man comes to the physican because of a 2 month history of inflamed thickened skin covered with silvery sclaes on the scalp, trunk, elbows, and knees. This condition has been poorly responsive to coal tar preparations, calcipotriene, and triamcinolone cream. What drug is the most appropriate next step in treatment.
Methotrexate
A 10 year old boy with mental retardation is brought to the physician by his parents because of a 2 week history of frequent staring spells. Examination of the skin shows pale oval shaped areas on the trunk. A CT scan of the head without contrast shows multiple calcified subependymal and cortical lesions. What is the most likely diagnosis?
Tuberous sclerosis
A 56 year old man with a 20 year history of chronic back pain undergoes operative placement of an electrode in his midbrain for pain management. Previous physical and neurologic examinations showed no abnormalities. When the implant is activated, the patient reports a marked decrease in pain. Administration of which of the following substances would most likely result in the return of this patient's pain? a) b endorphin b) enkephalin c) morphine d) naloxone e) oxycodone
Naloxone
A 45 year old woman develops proteinuria and hematuria. She has taken 3g of ibuprofen for headaches almost daily for the past 2 years. Which of the following findings is most likely in tissue obtained on renal biopsy?
Tubulointerstitial nephritis
A 27 year old woman comes to the physician because of a 3 month history of intermittent headaches and palpitations. Her initial BP is 125/80 while she sits in a chair. When asked to sit on the examination table, she has facial flushing, and her BP increases to 185/115. Physical exam shows no other abnormalities. What is the most likely diagnosis?
Pheochromocytoma
A 25 year old primigravid woman at 42 weeks gestation is admitted to the hospital for failure to begin spontaneous labor. She has no history of major medical illness. Pregnancy has been uncomplicated. Her vital signs are within normal limits. Intravenous infusion with oxytocin is initiated. Activation of which signaling pathway most likely mediates the therapeutic effect of this drug for this patient?
Phosphoinositide hydrolysis
Examination after cast removal on the left calf shows that it is smaller than the right calf. What process in that patient's myocytes is the most likely cause of this finding?
Polyubiquitination
A 22-year-old woman comes to the ER because of a 2 hour history of fever, chills, and muscle aches. Six hours ago, she received an injection of penicillin G benzathine for syphilis. Her temp is 102. Physical examination shows no other abnormalities. What best explains this patient's symptoms?
Release of bacterial products
A previously healthy 55 year old man has recently been diagnosed with HTN. He has not received any therapy. Lab studies show mild hypokalemia, metabolic alkalosis, and increased plasma renin activity and aldosterone concentration. Following administration of an ACE inhibitor, PRA increases further. What is the most likely cause of the HTN in this patient?
Renal artery stenosis
A 19 year old woman has severe refractory pustular acne that has been unresponsive to several topical and systemic therapies. Treatment with daily oral isotretinoin is begun. What pharmacologic effect of the drug is dependent on its binding to the RXR receptor?
Teratogenic effects in the embryo
Removal of the thymus at birth results in severely impaired immune responses. However, if the thymus is removed from adults, little if any deficit in immune responsiveness occurs because of what reason?
Thymic lymphocytes produced before thymectomy are long-lived
A 5 year old girl with AIDS develops a progressive generalized vesicular rash. High dose antiviral therapy for the agent that causes these lesions is ineffective, and the lesions become hyperkeratotic. The genetic mutation responsible for the absence of susceptibility to antiviral therapy involves the activity of what enzyme?
Thymidine kinase
A 2 month old girl is brought to the emergency department by her parents because of a 6 week history of constipation. She has also had poor feeding, sleepiness, and yellow skin during this period. Her parents are migrant workers, and she has not received routine medical care. Physical examination shows lethargy, hypotonia, jaundice, large fontanels, macroglossia, and an umbilial hernia. What is the most appropriate next step to establish the diagnosis?
Thyroid function tests
A previously healthy 16 year old girl comes to the physician because of a 4 day history of severe vaginal itching and a yellowish discharge. She is sexually active and uses condoms inconsistently. Pelvic exam shows a bubbly, yellowish vaginal discharge. Saline wet mount prep of the discharge and the vaginal wall scraping show motile organisms and numberous leukocytes. What is the most likely causal organism
Trichomonas vaginalis
A 51-year old man develops diaphoresis, tachycardia, and BP of 155/100 mmHg 24 hours after undergoing an abdominal operation. Two hours later, he has a generalized tonic-clonic seizure. What is most likely responsible for this adverse effect in the patient?
alcohol withdrawal
A mother who has toxoplasmosis gives birth to an asymptomatic female newborn. What following test on the newborn will indicate that the newborn has congenital Toxoplasma gondii infection?
antitoxoplasma IgM antibody concentrations
MOA of caspofungin
blocks B glucan carbohydrates in the cell wall
A 65 year old woman who has a 25-year history of chronic alcoholism is brought to the ER because she is vomiting blood. She eats little more than an occasional sandwich. Examination of the legs so perifollicular hyperkeratosis and hemorrhage. Abnormally decreased function of what metabolic pathways is most likely decreased in this patient?
hydroxylation of proline
A 57 year old man has a hemoglobin concentration of 18.5. This finding is most consistent with what disorder?
chronic obstructive pulmonary disease
Exposure to what type of air is most likely to precipitate an episode in a patient with exercise induced astham?
cold, dry air
Incomplete formation of pleuroperitoneal membrane
congenital diaphragmatic hernia
A 45 year old man is undergoing a surgical procedure. What maneuver by the anesthesiologist would result in an increase in intracranial pressure?
decreasing respiratory rate