Medical Notes: Answers to Various Health-Related Questions, Exams of Nursing

Download Medical Notes: Answers to Various Health-Related Questions and more Exams Nursing in PDF only on Docsity! NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. 3 types of benign colonic polyps - ansHyperplastic polyps (saw-toothed pattern) Juvenile polyp Peutz-Jeghers polyps 3 types of neoplastic polyps (adenoma) - ansTubular adenoma (pedunculated, most common) Tubulovillous adenoma (pedunculated) Villous adenoma (sessile, most malignant potential) 6yo boy from Russia with unstable gait and incoordination for 2 weeks. Pale, bulky stools for 4 years and two episodes of bacterial pneumonia and chronic cough since age 1 year. 3%ile for height/weight. Neuro exam shows ataxia, no DTRs, loss of proprioception. Stool shows inc fat concentration. Vitamin deficient? - ansE fragility of erythrocytes (hemolytic anemia) muscle weakness neurodysfunction poor joint sensation and ataxia 6yo boy with recurrent systemic infections with Neisseria meningitidis but healthy otherwise. What lab test is likely to be abnormal in this child? - ansTotal hemolytic complement concentration C5-C9 deficiency causes failure of formation of membrane attack complex (MAC) which causes susceptibility to Neisseria 8 weeks after recovering from pneumococcal pneumonia, CXR shows no abnormalities. What allowed this resolution to occur? - ansMaintenance of basement membrane integrity 14yo boy with daily headaches (bilateral aching in temples). "Not been himself", more confused, forgetting things. Clumsy with frequent falls. Broad-based ataxic gait. Slow to answer questions. Chronic abuse of what substance cause these symptoms? - ansInhaled glue 15yo girl emigrated from India and with several lesions on neck for 2 weeks. Physical exam shows hypopigmented, hypoesthetic area on left side of forehead and 4-cm lesions on neck. Biopsy shows acid- fast bacilli. Best explanation why the organism results in dermal rather than visceral infections? - ansTemperature sensitivity Mycobacterium leprae is non-motile acid-fast bacili that likes cool temperature. Reservoirs is amadillos. Cutaneous nodules with hypopigmentation, erythematous plaques with central hypopigmentation, peripheral neuropathy, lion-like facies 16yo girl with intermittent fainting while standing. Plasma studies show undetectable NE/Epi concentration and marked increase in dopamine concentration when rising from a supine position to standing Deficiency in what enzyme? - ansDopamine B-hydroxylase A rare form of dysautonomia. Dopamine is released as a false neurotransmitter in place of NE and Epi 17yo woman just ran a marathon. 1 day later has SOB, weakness, muscle tenderness, fever, tachypnea, edema, pulmonary crackles. Cr 4, UA with 3+ protein and 4+ hemoglobin NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. Release of what substance causes her symptoms? - ansMyoglobin Rhabdomyelysis -- Breakdown of muscles releases intracellular contents. Myoglobin causes renal tubular obstruction causing AKI, with proteinuria and myoglobinuria (which can be mistaken for hemoglobinuria) 25yo F with 3-year hx of irregular menses. Menarche was at age of 14 years. PE shows increased hair growth on the face and chest. Pelvic exam shows clitoromegaly and a normal-appearing uterus. Serum shows increased 17-hydroxyprogesterone and androstenedione. Deficiency of? - ans21-hydroxylase "Congenital adrenal hyperplasia" 25yo woman 6-month history of joint pain poorly responsive to aspirin. Physical exam: bilateral swelling of proximal interphalangeal joints, metacarpophalangeal joints, and wrists; weakness of grasp. Small nodules palpated beneath skin around joints of fingers. Dx? - ansRheumatoid arthritis 32yo M with 3-month hx of swelling and breast tenderness. Receiving thyroid hormone and steroid replacements since removal of pituitary adenoma 2 years ago. Began hCG injections 4 months ago. Most likely binding site of hCG causing gynecomastia? - ansTesticle --> estradiol production 35yo man with recurrent sinusitis and bronchitis throughout his life. One sister has similar history. Married with no children. Cardiac exam shows PMI on the right midclavicular 4th intercostal, hepatic margin on the left. Endoscopy shows nasal polyps, biopsy shows thickened, ciliated, pseudostratified epithelium with small patches of squamous metaplasia and mild lymphoid infiltration What disease and what structure would be missing on electron microscopy? - ansPrimary ciliary dyskinesia/Kartagener syndrome Dynein arms is missing or damaged --> cilia not working Triad of: situs inversus, chronic sinusitis, bronchiectasis For males, reduced fertility because low sperm motility 38yo M with 1-week hx of watery, itchy eyes and a runny nose. Physical shows inflamed nasal mucosa. No congestion in lower lung. Pharmacotherapy? - ansLoratadine First gen H1 blocker has strong sedative action and anticholinergic effects, and not recommended for people operating heavy machineries. Second gen H1 blocker is non-sedative (Loratidine, Cetirizine, Azelastine, Fexofenadine) 40yo M with extreme sensitivity to sunlight. Exposure to sun causes formation of vesicles and blisters on skin, which takes weeks to heal. He is diagnosed with a disorder caused by increased synthesis of compounds in the skin that are subject to excitation by visible light. What pathway is defective? - ansHeme synthesis Porphyria cutanea tarda is caused by defect in uroporphyrinogen decarboxylase in heme synthesis --> accumulation of uroporphyrin 1 Sx: blistering cutaneous photosensitivity caused by hepatotoxic triggers (alcohol, estrogens). Most common type or porphyria NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. DIC labs? PT/INR: aPTT: Platelet count: Fibrinogen: Fibrin degradation products: D-Dimer: Antithromibin III: - ansPT/INR: increased aPTT: increased Platelet count: down Fibrinogen: down Fibrin degradation products: up D-Dimer: positive Antithromibin III: low Etiology of congenital diaphragmatic hernia? - ansIncomplete formation of pleuroperitoneal membrane Ezetimibe MOA - ansinhibits sterol transporter at the small intestine brush border, preventing the absorption of cholesterol First sign of puberty in females? Males? - ansFemales: breast bud development Males: testicular enlargement Fracture of the jaw would affect what nerve? - ansInferior alveolar nerve Gentamicin MOA - ansBinds to 30S --> block initiation, slow initiated synthesis, induces incorporation of wrong amino-acid Hemochromatosis caused by? - ansIncreased intestinal iron absorption (HFE mutation --> liver falsely sensed low iron --> enterocytes upregulate DMT1 iron transporter to bring more iron in) Hemophilia A deficient in what factor? - ansVIII Hemophilia B deficient in what factor? - ansIX Hormones of Posterior Pituitary - ansADH and oxytocin Hormones of the Anterior Pituitary - ansLH, FSH, ACTH, TSH, Prolactin, GH Ibutilide adverse effects - ansTorsades de pointes In pts with DKA, what hormone stimulated hormone-sensitive lipase in adipocytes that results in accumulation of ketones? - ansEpinephrine Leydig cells is stimulated by what pituitary hormone to produce testosterone? - ansLH (testosterone is negative feedback on hypothalamus to inhibit GnRH secretion) NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. (FSH stimulates Sertoli cells which increase synthesis of androgen binding proteins, as well as inhibin that acts as negative feedback on pituitary) Lyme disease treatment - ansDoxycycline, amoxicillin, or cefuroxime have all been shown to have equivalent efficacy for treatment of Lyme disease. Male newborn has macrocephaly with poor skull mineralization, shortened extremities with misshaped long bones, and several fx. Defect in which? - ansCollage (Type I) Osteogenesis imperfecta: blue sclera, multiple fractures, hearing loss, dental abnormalities Mechanism of action of cholera toxin - ansActivates adenylate cyclase → increased cAMP → increased chloride efflux + decreased sodium reabsorption → massive, watery diarrhea; also induces mucin ejection by goblet cells Mechanism of wound healing after burn. Two weeks after injury, there is increased fibroblast migration and proliferation, increased synthesis of collagen and fibronectin, and decreased degradation of extracellular matrix by metalloproteinases. These changes were caused by enhanced cellular production of which factor? - ansTGF-B **Note: wound healing mediated by growth factors in general (TGF-a, FGF, etc.) Menopause is caused by - ansfailure of ovaries to secrete 17B-estradiol Missing C1 esterase inhibitor causes what? - ansHereditary angioedema ACE inhibitors are contraindicated Unregulated activation of kallikrein by complement system leading to increased bradykinin activity Missing C3 factor causes what? - ansRecurrent infection by pyogenic bacteria (2/2 lack of immune complex and pathologic bacterial clearance) Increased susceptibility to type III hypersensitivity reactions Missing CD55 causes what? - ansParoxysmal nocturnal hemoglobinuria Due to unregulated activation of complements leading to lysis of RBCs MOA of methyphenidate - ansIncreased release of dopamine and NE Name of opioid antidiarrheal agent with little or no ability to produce CNS effects? - ansLoperamide/diphenoxylase Agonist at mu opioid receptor Nasopharyngeal cancer is associated with what virus? - ansEBV Neural tube closure occurs when? - ansDay 15-40 (around 4 weeks average) NSAID use in patients with HTN and bilateral renal artery stenosis would have a bump in creatinine due to what mechanism? - ansInhibition of vasodilating prostaglandins at the afferent arteriole NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. In contrast to ACEi/ARBs, which inhibit vasoconstriction at the efferent arteriole Odds ratio equation - ansOR = (ad)/(bc) Phases of clinical trials - ansPhase 1: small number of healthy volunteers to measure safety, toxicity, and pharmacokinetics Phase 2: small number of sick volunteers with disease of interest to measure treatment efficacy, optimal dosing, and adverse effects Phase 3: large number of randomly assigned either to treatment under investigation of to the best available treatment (or to placebo group to compare the new treatment to the current standard of care or placebo Phase 4: Postmarketing surveillance trial of patients after approval to detect rare or long-term adverse effects rash on arms and legs after camping trip in woods, edematous, erythematous rash with linear vesicles, activation of what cells? - ansT-lymphocytes -- Type IV hypersensitivity reaction with activation of Th1 cells after exposure to poison ivy Sildenafil MOA - ansInhibition of cGMP phosphodiesterase type 5 (PDE5)--> increased cGMP level --> drives smooth muscle relaxation in corpus cavernosum --> increased blood flow to penis Swimming in cold water up tot he neck. What happens to: - central blood volume - ADH - ANP - ans- Central blood volume: increased - ADH: decreased - ANP: increased symptoms of beriberi - ansperipheral neuropathy and weakness, muscle pain and tenderness, enlargement of the heart, difficulty breathing, edema, anorexia, weight loss, poor memory and confusion Symptoms of pellagra? - ans3 D's of niacin deficiency dementia, dermatitis, diarrhea, / death Symptoms of salicylate poisoning - ansearly: brain sx -tinnitus -vertigo -nausea/vomiting -resp alkalosis b/c taking deep breaths late: -hyperpyrexia -anion gap acidosis -obtunded NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. 15yo girl emigrated from India and with several lesions on neck for 2 weeks. Physical exam shows hypopigmented, hypoesthetic area on left side of forehead and 4-cm lesions on neck. Biopsy shows acid- fast bacilli. Best explanation why the organism results in dermal rather than visceral infections? - ansTemperature sensitivity Mycobacterium leprae is non-motile acid-fast bacili that likes cool temperature. Reservoirs is amadillos. Cutaneous nodules with hypopigmentation, erythematous plaques with central hypopigmentation, peripheral neuropathy, lion-like facies 16yo girl with intermittent fainting while standing. Plasma studies show undetectable NE/Epi concentration and marked increase in dopamine concentration when rising from a supine position to standing Deficiency in what enzyme? - ansDopamine B-hydroxylase A rare form of dysautonomia. Dopamine is released as a false neurotransmitter in place of NE and Epi 17yo woman just ran a marathon. 1 day later has SOB, weakness, muscle tenderness, fever, tachypnea, edema, pulmonary crackles. Cr 4, UA with 3+ protein and 4+ hemoglobin Release of what substance causes her symptoms? - ansMyoglobin Rhabdomyelysis -- Breakdown of muscles releases intracellular contents. Myoglobin causes renal tubular obstruction causing AKI, with proteinuria and myoglobinuria (which can be mistaken for hemoglobinuria) 25yo F with 3-year hx of irregular menses. Menarche was at age of 14 years. PE shows increased hair growth on the face and chest. Pelvic exam shows clitoromegaly and a normal-appearing uterus. Serum shows increased 17-hydroxyprogesterone and androstenedione. Deficiency of? - ans21-hydroxylase "Congenital adrenal hyperplasia" 25yo woman 6-month history of joint pain poorly responsive to aspirin. Physical exam: bilateral swelling of proximal interphalangeal joints, metacarpophalangeal joints, and wrists; weakness of grasp. Small nodules palpated beneath skin around joints of fingers. Dx? - ansRheumatoid arthritis 32yo M with 3-month hx of swelling and breast tenderness. Receiving thyroid hormone and steroid replacements since removal of pituitary adenoma 2 years ago. Began hCG injections 4 months ago. Most likely binding site of hCG causing gynecomastia? - ansTesticle --> estradiol production 35yo man with recurrent sinusitis and bronchitis throughout his life. One sister has similar history. Married with no children. Cardiac exam shows PMI on the right midclavicular 4th intercostal, hepatic margin on the left. Endoscopy shows nasal polyps, biopsy shows thickened, ciliated, pseudostratified epithelium with small patches of squamous metaplasia and mild lymphoid infiltration What disease and what structure would be missing on electron microscopy? - ansPrimary ciliary dyskinesia/Kartagener syndrome Dynein arms is missing or damaged --> cilia not working Triad of: situs inversus, chronic sinusitis, bronchiectasis For males, reduced fertility because low sperm motility NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. 38yo M with 1-week hx of watery, itchy eyes and a runny nose. Physical shows inflamed nasal mucosa. No congestion in lower lung. Pharmacotherapy? - ansLoratadine First gen H1 blocker has strong sedative action and anticholinergic effects, and not recommended for people operating heavy machineries. Second gen H1 blocker is non-sedative (Loratidine, Cetirizine, Azelastine, Fexofenadine) 40yo M with extreme sensitivity to sunlight. Exposure to sun causes formation of vesicles and blisters on skin, which takes weeks to heal. He is diagnosed with a disorder caused by increased synthesis of compounds in the skin that are subject to excitation by visible light. What pathway is defective? - ansHeme synthesis Porphyria cutanea tarda is caused by defect in uroporphyrinogen decarboxylase in heme synthesis --> accumulation of uroporphyrin 1 Sx: blistering cutaneous photosensitivity caused by hepatotoxic triggers (alcohol, estrogens). Most common type or porphyria 40yo M with interstitial pulmonary fibrosis has greater maximal expiratory flow rate than predicted. Which best explains this? - ansIncreased radial traction on airway The connective tissue that surrounds the airways of the lungs are called the parenchyma. This forms a sort of scaffold around the airways, keeping them open with a force known as "radial traction". Radial traction is the "spring" that bounce back to force air out. Fibrosis increases radial traction 44-year-old woman comes to the physician for a follow-up examination after two separate Pap smears showed atypical squamous cells of undetermined significance. Results of a molecular diagnostic test show the presence of the viral E6 protein of human papillomavirus. This protein is known to promote cell growth and malignancy by causing cellular p53 protein degradation. This degradation most likely begins when the p53 protein is targeted to which of the following types of cellular enzymes? - ansUbiquitin ligase protein degradation 56yo M 4 hours after sudden onset of uncontrollable irregular movements of the left side of the body. PE shows flailing movements of the proximal appendicular muscles on the left. Nuclei damaged? - ansRight subthalamic Hemiballismus is flinging/flailing movement of one side, caused by damage to the CONTRALATERAL subthalamic nucleus. Likely 2/2 to lacunar infarct 60yo M flow cytometry of peripheral lymphocytes show: CD3 50% CD4 40% CD8 10% CD20 50% Surface kappa 47% Surface lamba 3% What is predictive of a clonal lymphoid proliferation? - anssurface kappa:surface lambda ratio NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. Each plasma cell can only make either kappa or lambda. Normal ratio about 3:1. If one is much higher than the other, that means there is MONOCLONAL proliferation (instead of the normal polyclonal), such as in multiple myeloma 60yo M shipyard worker with progressive SOB pas 3 months. Xray of chest shows reticulonodular pulmonary infiltrates consistent with interstitial fibrosis. Microscopic exam of sputum shows occasional elongate structures (golden-brown fusiform rods). The fibrosis was most likely initiated by interaction of these structures with which cell type? - ansAlveolar macrophage Asbestosis - increased risk of bronchogenic carcinoma and mesothelioma 60yo M sudden onset of acute abdominal pain and tenderness, n/v, bloody diarrhea for 2 hours. History of cirrhosis and HCC. BP 99/50. Rigid abdominal pain with loss of bowel sounds. Half of small intestine is found to have a dark purple-red hemorrhagic appearance. What is the cause? - ansMesenteric venous thrombosis 60yo peanut farmer in China with sxs of hepatocellular carcinoma. No alcohol, negative Hep B/C. What is the cause? - ansAflatoxin (released by Aspergillus, contained in maize, peanuts, cotton seeds, tree nuts) 62yo M with pericardial friction rub 3 days after acute myocardial infarction. Cause of rub? - ansFibrinous pericarditis (Dressler syndrome) 65yo M emigrated from Brazil with 8-month history of shortness of breath and fatigue, edema of lower ext. CXR shows cardiomegaly. endomyocardial biopsy specimen shows myofiber necrosis with a mixed inflammatory infiltrate of PMNs, T lymphos, m.phages, and eosinophils. Causal org? - ansTrypanosoma cruzi 65yo woman with progressive vulvar itching not relieved with miconazole. Atrophy of labia minora and thin, parchment-like skin over vulva and around anus. Dx? - ansLichen sclerosus chronic inflammatory disease with characteristic white, atrophic plaques. Tx: topical steroids 68yo M difficulty swallowing solids, with history of dilated cardiomyopathy. Xray of esophagus with barium show indentation and posterior displacement of the esophagus. Enlargement of which heart chamber is the cause? - ansLeft atrium 70yo M from China has poorly differentiated monoclonal carcinoma of the nasopharynx. DNA probes of neoplastic cells most likely to detect what viral genome? - ansEBV A farmer is taking itraconazole for histoplasmosis acquired after contact with chicken coop. He still shows persistent symptoms despite 4 wks of therapy. Other medications include: HTCZ, enalapril, atenolol, omeprazole, metoclopramide. What drug causes lack of effect of itraconazole? - ansOmeprazole Itraconazole and other triazole antifungals comes in a capsule that requires acidic pH in the stomach to be absorbed in the duodenum. Omeprazole reduces acids --> low absorption of itraconazole NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. Missing CD55 causes what? - ansParoxysmal nocturnal hemoglobinuria Due to unregulated activation of complements leading to lysis of RBCs MOA of methyphenidate - ansIncreased release of dopamine and NE Name of opioid antidiarrheal agent with little or no ability to produce CNS effects? - ansLoperamide/diphenoxylase Agonist at mu opioid receptor Nasopharyngeal cancer is associated with what virus? - ansEBV Neural tube closure occurs when? - ansDay 15-40 (around 4 weeks average) NSAID use in patients with HTN and bilateral renal artery stenosis would have a bump in creatinine due to what mechanism? - ansInhibition of vasodilating prostaglandins at the afferent arteriole In contrast to ACEi/ARBs, which inhibit vasoconstriction at the efferent arteriole Odds ratio equation - ansOR = (ad)/(bc) Phases of clinical trials - ansPhase 1: small number of healthy volunteers to measure safety, toxicity, and pharmacokinetics Phase 2: small number of sick volunteers with disease of interest to measure treatment efficacy, optimal dosing, and adverse effects Phase 3: large number of randomly assigned either to treatment under investigation of to the best available treatment (or to placebo group to compare the new treatment to the current standard of care or placebo Phase 4: Postmarketing surveillance trial of patients after approval to detect rare or long-term adverse effects rash on arms and legs after camping trip in woods, edematous, erythematous rash with linear vesicles, activation of what cells? - ansT-lymphocytes -- Type IV hypersensitivity reaction with activation of Th1 cells after exposure to poison ivy Sildenafil MOA - ansInhibition of cGMP phosphodiesterase type 5 (PDE5)--> increased cGMP level --> drives smooth muscle relaxation in corpus cavernosum --> increased blood flow to penis Swimming in cold water up tot he neck. What happens to: - central blood volume - ADH - ANP - ans- Central blood volume: increased - ADH: decreased - ANP: increased NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. symptoms of beriberi - ansperipheral neuropathy and weakness, muscle pain and tenderness, enlargement of the heart, difficulty breathing, edema, anorexia, weight loss, poor memory and confusion Symptoms of pellagra? - ans3 D's of niacin deficiency dementia, dermatitis, diarrhea, / death Symptoms of salicylate poisoning - ansearly: brain sx -tinnitus -vertigo -nausea/vomiting -resp alkalosis b/c taking deep breaths late: -hyperpyrexia -anion gap acidosis -obtunded Treatment for PE and MOA? - ansHeparin -- potentiates the action of antithrombin III, which inactivates several factors. Warfarin -- inhibits hepatic synthesis of Vit K-dependent factors Treatment of inflammatory bowel disease and MOA? - ansInfliximab - TNF-alpha monoclonal antibody Mesalamine - 5-ASA (COX inhibitor) Sulfasalazine - Combo of 5-ASA (COX inhibitor) and sulfapyridine (suppress B cells) Uterine artery is a branch of what artery? - ansInternal iliac artery warfarin decreases what factors? - ansFactor II, VII, IX, X Protein C and S (which gets depleted first --> warfarin-associated tissue necrosis) What cancers is EBV associated with? - ansNasopharyngeal carcinoma in Asians Burkitt lymphoma in endemic areas CNS lymphoma in AIDS What cytokines are released to cause fever and inflammation? - ansIL-1 and TNF-a What diuretics should be used in addition to loop diuretic for pts with ascites - ansSpironolactone Actually more efficacious than loop diuretic in ascites. If use furosemide, then need to be used in conjunction with spironolactone What does the liver biopsy show in alcoholic liver disease? - ansneutrophil infiltration, hepatocyte ballooning and Mallory bodies/hyaline What happens to calcium level in sarcoidosis? - ansincreased serum calcium secondary to increased conversion of 25-hydroxyvitamin D (calcidiol) to 1,25-dihydroxyvitamin D3 (calcitriol) by 1-alpha hydroxylase produced by the macrophages of granulomas. NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. What is the mechanism of continued CK-MB and troponin I increase after coronary stenting? - ansMembrane lipid peroxidation (due to reperfusion injury which causes free radicals) What is the next step in newborn with possible fatty acid oxidation defect? - ansMeasure serum acylcarnitine concentrations Carnitine deficiency results in toxic accumulation of LCFA in the cytoplasm of myocytes and other cells. Patients present with hypoketotic hypoglycemia, fatty liver, myopathy, hypotonia, and fatigue. Treatment consists of oral supplementation of the amino acid carnitine. What kind of kidney stones cause staghorn calculi with urine pH=8? - ansStruvite (due to urease-producing bacteria -- Proteus mirabilis, Staph saphrophryticus, Klebsiella -- causing basic urine pH and precipitation of struvite) What marker to monitor thyroid cancer recurrence? - ansCalcitonin What month in normal child development includes using pincer grasp, finger feeding, standing while holding onto a table, and playing peekaboo? - ans9 months What tissue is choriocarcinoma made of? - ansTrophoblastic tissue Often presents after incomplete removal of hydatidiform mole, normal pregnancy, or abortion. Elevated B- hCG. Metastasize hematogenously commonly to lungs. Tx: methotrexate What two organs have gluconeogenesis - ansLiver and kidney Where is the AV node located? - ansinteratrial septum near the opening of the coronary sinus Where is the SA node located? - ansjunction of superior vena cava and right atrium Which vaccine cause conversion of T-independent antigens to T-dependent forms to enhance protection in young children? - ansH flu type b 3 types of benign colonic polyps - ansHyperplastic polyps (saw-toothed pattern) Juvenile polyp Peutz-Jeghers polyps 3 types of neoplastic polyps (adenoma) - ansTubular adenoma (pedunculated, most common) Tubulovillous adenoma (pedunculated) Villous adenoma (sessile, most malignant potential) 6yo boy from Russia with unstable gait and incoordination for 2 weeks. Pale, bulky stools for 4 years and two episodes of bacterial pneumonia and chronic cough since age 1 year. 3%ile for height/weight. Neuro exam shows ataxia, no DTRs, loss of proprioception. Stool shows inc fat concentration. Vitamin deficient? - ansE fragility of erythrocytes (hemolytic anemia) muscle weakness neurodysfunction NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. 56yo M 4 hours after sudden onset of uncontrollable irregular movements of the left side of the body. PE shows flailing movements of the proximal appendicular muscles on the left. Nuclei damaged? - ansRight subthalamic Hemiballismus is flinging/flailing movement of one side, caused by damage to the CONTRALATERAL subthalamic nucleus. Likely 2/2 to lacunar infarct 60yo M flow cytometry of peripheral lymphocytes show: CD3 50% CD4 40% CD8 10% CD20 50% Surface kappa 47% Surface lamba 3% What is predictive of a clonal lymphoid proliferation? - anssurface kappa:surface lambda ratio Each plasma cell can only make either kappa or lambda. Normal ratio about 3:1. If one is much higher than the other, that means there is MONOCLONAL proliferation (instead of the normal polyclonal), such as in multiple myeloma 60yo M shipyard worker with progressive SOB pas 3 months. Xray of chest shows reticulonodular pulmonary infiltrates consistent with interstitial fibrosis. Microscopic exam of sputum shows occasional elongate structures (golden-brown fusiform rods). The fibrosis was most likely initiated by interaction of these structures with which cell type? - ansAlveolar macrophage Asbestosis - increased risk of bronchogenic carcinoma and mesothelioma 60yo M sudden onset of acute abdominal pain and tenderness, n/v, bloody diarrhea for 2 hours. History of cirrhosis and HCC. BP 99/50. Rigid abdominal pain with loss of bowel sounds. Half of small intestine is found to have a dark purple-red hemorrhagic appearance. What is the cause? - ansMesenteric venous thrombosis 60yo peanut farmer in China with sxs of hepatocellular carcinoma. No alcohol, negative Hep B/C. What is the cause? - ansAflatoxin (released by Aspergillus, contained in maize, peanuts, cotton seeds, tree nuts) 62yo M with pericardial friction rub 3 days after acute myocardial infarction. Cause of rub? - ansFibrinous pericarditis (Dressler syndrome) 65yo M emigrated from Brazil with 8-month history of shortness of breath and fatigue, edema of lower ext. CXR shows cardiomegaly. endomyocardial biopsy specimen shows myofiber necrosis with a mixed inflammatory infiltrate of PMNs, T lymphos, m.phages, and eosinophils. Causal org? - ansTrypanosoma cruzi 65yo woman with progressive vulvar itching not relieved with miconazole. Atrophy of labia minora and thin, parchment-like skin over vulva and around anus. Dx? - ansLichen sclerosus chronic inflammatory disease with characteristic white, atrophic plaques. Tx: topical steroids NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. 68yo M difficulty swallowing solids, with history of dilated cardiomyopathy. Xray of esophagus with barium show indentation and posterior displacement of the esophagus. Enlargement of which heart chamber is the cause? - ansLeft atrium 70yo M from China has poorly differentiated monoclonal carcinoma of the nasopharynx. DNA probes of neoplastic cells most likely to detect what viral genome? - ansEBV A farmer is taking itraconazole for histoplasmosis acquired after contact with chicken coop. He still shows persistent symptoms despite 4 wks of therapy. Other medications include: HTCZ, enalapril, atenolol, omeprazole, metoclopramide. What drug causes lack of effect of itraconazole? - ansOmeprazole Itraconazole and other triazole antifungals comes in a capsule that requires acidic pH in the stomach to be absorbed in the duodenum. Omeprazole reduces acids --> low absorption of itraconazole A pregnant women with abd pain for 12 hrs and upper quadrant pain. her labs show decreased platelets and hemoglobin and elevated liver enzymes. what would you expect on peripheral blood smear? - ansSchistocytes HELLP syndrome is preeclampsia Hemolysis, Elevated LFTs, Low Platelets. Peripheral blood smear shows schistocytes due to hemolysis Alendronate MOA - ansinhibition of osteoclast-mediation bone resorption Blood agglutination is caused by what antibody isotype? - ansIgM Boy with anemia since birth with splenomegaly. Splenectomy is indicated if the anemia is caused by which disorders? - ansHereditary spherocytosis Cyclophosphamide MOA - ansAlkylating agent --> crosslinking of DNA --> inhibits DNA replication Cyclosporin decreases transplant rejection by what mechanism? - ansSuppressing early response of T lymphocytes to activation DIC labs? PT/INR: aPTT: Platelet count: Fibrinogen: Fibrin degradation products: D-Dimer: Antithromibin III: - ansPT/INR: increased aPTT: increased Platelet count: down Fibrinogen: down Fibrin degradation products: up D-Dimer: positive NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. Antithromibin III: low Etiology of congenital diaphragmatic hernia? - ansIncomplete formation of pleuroperitoneal membrane Ezetimibe MOA - ansinhibits sterol transporter at the small intestine brush border, preventing the absorption of cholesterol First sign of puberty in females? Males? - ansFemales: breast bud development Males: testicular enlargement Fracture of the jaw would affect what nerve? - ansInferior alveolar nerve Gentamicin MOA - ansBinds to 30S --> block initiation, slow initiated synthesis, induces incorporation of wrong amino-acid Hemochromatosis caused by? - ansIncreased intestinal iron absorption (HFE mutation --> liver falsely sensed low iron --> enterocytes upregulate DMT1 iron transporter to bring more iron in) Hemophilia A deficient in what factor? - ansVIII Hemophilia B deficient in what factor? - ansIX Hormones of Posterior Pituitary - ansADH and oxytocin Hormones of the Anterior Pituitary - ansLH, FSH, ACTH, TSH, Prolactin, GH Ibutilide adverse effects - ansTorsades de pointes In pts with DKA, what hormone stimulated hormone-sensitive lipase in adipocytes that results in accumulation of ketones? - ansEpinephrine Leydig cells is stimulated by what pituitary hormone to produce testosterone? - ansLH (testosterone is negative feedback on hypothalamus to inhibit GnRH secretion) (FSH stimulates Sertoli cells which increase synthesis of androgen binding proteins, as well as inhibin that acts as negative feedback on pituitary) Lyme disease treatment - ansDoxycycline, amoxicillin, or cefuroxime have all been shown to have equivalent efficacy for treatment of Lyme disease. Male newborn has macrocephaly with poor skull mineralization, shortened extremities with misshaped long bones, and several fx. Defect in which? - ansCollage (Type I) Osteogenesis imperfecta: blue sclera, multiple fractures, hearing loss, dental abnormalities Mechanism of action of cholera toxin - ansActivates adenylate cyclase → increased cAMP → increased chloride efflux + decreased sodium reabsorption → massive, watery diarrhea; also induces mucin ejection by goblet cells NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. What cytokines are released to cause fever and inflammation? - ansIL-1 and TNF-a What diuretics should be used in addition to loop diuretic for pts with ascites - ansSpironolactone Actually more efficacious than loop diuretic in ascites. If use furosemide, then need to be used in conjunction with spironolactone What does the liver biopsy show in alcoholic liver disease? - ansneutrophil infiltration, hepatocyte ballooning and Mallory bodies/hyaline What happens to calcium level in sarcoidosis? - ansincreased serum calcium secondary to increased conversion of 25-hydroxyvitamin D (calcidiol) to 1,25-dihydroxyvitamin D3 (calcitriol) by 1-alpha hydroxylase produced by the macrophages of granulomas. What is the mechanism of continued CK-MB and troponin I increase after coronary stenting? - ansMembrane lipid peroxidation (due to reperfusion injury which causes free radicals) What is the next step in newborn with possible fatty acid oxidation defect? - ansMeasure serum acylcarnitine concentrations Carnitine deficiency results in toxic accumulation of LCFA in the cytoplasm of myocytes and other cells. Patients present with hypoketotic hypoglycemia, fatty liver, myopathy, hypotonia, and fatigue. Treatment consists of oral supplementation of the amino acid carnitine. What kind of kidney stones cause staghorn calculi with urine pH=8? - ansStruvite (due to urease-producing bacteria -- Proteus mirabilis, Staph saphrophryticus, Klebsiella -- causing basic urine pH and precipitation of struvite) What marker to monitor thyroid cancer recurrence? - ansCalcitonin What month in normal child development includes using pincer grasp, finger feeding, standing while holding onto a table, and playing peekaboo? - ans9 months What tissue is choriocarcinoma made of? - ansTrophoblastic tissue Often presents after incomplete removal of hydatidiform mole, normal pregnancy, or abortion. Elevated B- hCG. Metastasize hematogenously commonly to lungs. Tx: methotrexate What two organs have gluconeogenesis - ansLiver and kidney Where is the AV node located? - ansinteratrial septum near the opening of the coronary sinus Where is the SA node located? - ansjunction of superior vena cava and right atrium Which vaccine cause conversion of T-independent antigens to T-dependent forms to enhance protection in young children? - ansH flu type b NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. 3 types of benign colonic polyps - ansHyperplastic polyps (saw-toothed pattern) Juvenile polyp Peutz-Jeghers polyps 3 types of neoplastic polyps (adenoma) - ansTubular adenoma (pedunculated, most common) Tubulovillous adenoma (pedunculated) Villous adenoma (sessile, most malignant potential) 6yo boy from Russia with unstable gait and incoordination for 2 weeks. Pale, bulky stools for 4 years and two episodes of bacterial pneumonia and chronic cough since age 1 year. 3%ile for height/weight. Neuro exam shows ataxia, no DTRs, loss of proprioception. Stool shows inc fat concentration. Vitamin deficient? - ansE fragility of erythrocytes (hemolytic anemia) muscle weakness neurodysfunction poor joint sensation and ataxia 6yo boy with recurrent systemic infections with Neisseria meningitidis but healthy otherwise. What lab test is likely to be abnormal in this child? - ansTotal hemolytic complement concentration C5-C9 deficiency causes failure of formation of membrane attack complex (MAC) which causes susceptibility to Neisseria 8 weeks after recovering from pneumococcal pneumonia, CXR shows no abnormalities. What allowed this resolution to occur? - ansMaintenance of basement membrane integrity 14yo boy with daily headaches (bilateral aching in temples). "Not been himself", more confused, forgetting things. Clumsy with frequent falls. Broad-based ataxic gait. Slow to answer questions. Chronic abuse of what substance cause these symptoms? - ansInhaled glue 15yo girl emigrated from India and with several lesions on neck for 2 weeks. Physical exam shows hypopigmented, hypoesthetic area on left side of forehead and 4-cm lesions on neck. Biopsy shows acid- fast bacilli. Best explanation why the organism results in dermal rather than visceral infections? - ansTemperature sensitivity Mycobacterium leprae is non-motile acid-fast bacili that likes cool temperature. Reservoirs is amadillos. Cutaneous nodules with hypopigmentation, erythematous plaques with central hypopigmentation, peripheral neuropathy, lion-like facies 16yo girl with intermittent fainting while standing. Plasma studies show undetectable NE/Epi concentration and marked increase in dopamine concentration when rising from a supine position to standing Deficiency in what enzyme? - ansDopamine B-hydroxylase A rare form of dysautonomia. Dopamine is released as a false neurotransmitter in place of NE and Epi 17yo woman just ran a marathon. 1 day later has SOB, weakness, muscle tenderness, fever, tachypnea, edema, pulmonary crackles. Cr 4, UA with 3+ protein and 4+ hemoglobin NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. Release of what substance causes her symptoms? - ansMyoglobin Rhabdomyelysis -- Breakdown of muscles releases intracellular contents. Myoglobin causes renal tubular obstruction causing AKI, with proteinuria and myoglobinuria (which can be mistaken for hemoglobinuria) 25yo F with 3-year hx of irregular menses. Menarche was at age of 14 years. PE shows increased hair growth on the face and chest. Pelvic exam shows clitoromegaly and a normal-appearing uterus. Serum shows increased 17-hydroxyprogesterone and androstenedione. Deficiency of? - ans21-hydroxylase "Congenital adrenal hyperplasia" 25yo woman 6-month history of joint pain poorly responsive to aspirin. Physical exam: bilateral swelling of proximal interphalangeal joints, metacarpophalangeal joints, and wrists; weakness of grasp. Small nodules palpated beneath skin around joints of fingers. Dx? - ansRheumatoid arthritis 32yo M with 3-month hx of swelling and breast tenderness. Receiving thyroid hormone and steroid replacements since removal of pituitary adenoma 2 years ago. Began hCG injections 4 months ago. Most likely binding site of hCG causing gynecomastia? - ansTesticle --> estradiol production 35yo man with recurrent sinusitis and bronchitis throughout his life. One sister has similar history. Married with no children. Cardiac exam shows PMI on the right midclavicular 4th intercostal, hepatic margin on the left. Endoscopy shows nasal polyps, biopsy shows thickened, ciliated, pseudostratified epithelium with small patches of squamous metaplasia and mild lymphoid infiltration What disease and what structure would be missing on electron microscopy? - ansPrimary ciliary dyskinesia/Kartagener syndrome Dynein arms is missing or damaged --> cilia not working Triad of: situs inversus, chronic sinusitis, bronchiectasis For males, reduced fertility because low sperm motility 38yo M with 1-week hx of watery, itchy eyes and a runny nose. Physical shows inflamed nasal mucosa. No congestion in lower lung. Pharmacotherapy? - ansLoratadine First gen H1 blocker has strong sedative action and anticholinergic effects, and not recommended for people operating heavy machineries. Second gen H1 blocker is non-sedative (Loratidine, Cetirizine, Azelastine, Fexofenadine) 40yo M with extreme sensitivity to sunlight. Exposure to sun causes formation of vesicles and blisters on skin, which takes weeks to heal. He is diagnosed with a disorder caused by increased synthesis of compounds in the skin that are subject to excitation by visible light. What pathway is defective? - ansHeme synthesis Porphyria cutanea tarda is caused by defect in uroporphyrinogen decarboxylase in heme synthesis --> accumulation of uroporphyrin 1 Sx: blistering cutaneous photosensitivity caused by hepatotoxic triggers (alcohol, estrogens). Most common type or porphyria NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. DIC labs? PT/INR: aPTT: Platelet count: Fibrinogen: Fibrin degradation products: D-Dimer: Antithromibin III: - ansPT/INR: increased aPTT: increased Platelet count: down Fibrinogen: down Fibrin degradation products: up D-Dimer: positive Antithromibin III: low Etiology of congenital diaphragmatic hernia? - ansIncomplete formation of pleuroperitoneal membrane Ezetimibe MOA - ansinhibits sterol transporter at the small intestine brush border, preventing the absorption of cholesterol First sign of puberty in females? Males? - ansFemales: breast bud development Males: testicular enlargement Fracture of the jaw would affect what nerve? - ansInferior alveolar nerve Gentamicin MOA - ansBinds to 30S --> block initiation, slow initiated synthesis, induces incorporation of wrong amino-acid Hemochromatosis caused by? - ansIncreased intestinal iron absorption (HFE mutation --> liver falsely sensed low iron --> enterocytes upregulate DMT1 iron transporter to bring more iron in) Hemophilia A deficient in what factor? - ansVIII Hemophilia B deficient in what factor? - ansIX Hormones of Posterior Pituitary - ansADH and oxytocin Hormones of the Anterior Pituitary - ansLH, FSH, ACTH, TSH, Prolactin, GH Ibutilide adverse effects - ansTorsades de pointes In pts with DKA, what hormone stimulated hormone-sensitive lipase in adipocytes that results in accumulation of ketones? - ansEpinephrine Leydig cells is stimulated by what pituitary hormone to produce testosterone? - ansLH (testosterone is negative feedback on hypothalamus to inhibit GnRH secretion) NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. (FSH stimulates Sertoli cells which increase synthesis of androgen binding proteins, as well as inhibin that acts as negative feedback on pituitary) Lyme disease treatment - ansDoxycycline, amoxicillin, or cefuroxime have all been shown to have equivalent efficacy for treatment of Lyme disease. Male newborn has macrocephaly with poor skull mineralization, shortened extremities with misshaped long bones, and several fx. Defect in which? - ansCollage (Type I) Osteogenesis imperfecta: blue sclera, multiple fractures, hearing loss, dental abnormalities Mechanism of action of cholera toxin - ansActivates adenylate cyclase → increased cAMP → increased chloride efflux + decreased sodium reabsorption → massive, watery diarrhea; also induces mucin ejection by goblet cells Mechanism of wound healing after burn. Two weeks after injury, there is increased fibroblast migration and proliferation, increased synthesis of collagen and fibronectin, and decreased degradation of extracellular matrix by metalloproteinases. These changes were caused by enhanced cellular production of which factor? - ansTGF-B **Note: wound healing mediated by growth factors in general (TGF-a, FGF, etc.) Menopause is caused by - ansfailure of ovaries to secrete 17B-estradiol Missing C1 esterase inhibitor causes what? - ansHereditary angioedema ACE inhibitors are contraindicated Unregulated activation of kallikrein by complement system leading to increased bradykinin activity Missing C3 factor causes what? - ansRecurrent infection by pyogenic bacteria (2/2 lack of immune complex and pathologic bacterial clearance) Increased susceptibility to type III hypersensitivity reactions Missing CD55 causes what? - ansParoxysmal nocturnal hemoglobinuria Due to unregulated activation of complements leading to lysis of RBCs MOA of methyphenidate - ansIncreased release of dopamine and NE Name of opioid antidiarrheal agent with little or no ability to produce CNS effects? - ansLoperamide/diphenoxylase Agonist at mu opioid receptor Nasopharyngeal cancer is associated with what virus? - ansEBV Neural tube closure occurs when? - ansDay 15-40 (around 4 weeks average) NSAID use in patients with HTN and bilateral renal artery stenosis would have a bump in creatinine due to what mechanism? - ansInhibition of vasodilating prostaglandins at the afferent arteriole NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. In contrast to ACEi/ARBs, which inhibit vasoconstriction at the efferent arteriole Odds ratio equation - ansOR = (ad)/(bc) Phases of clinical trials - ansPhase 1: small number of healthy volunteers to measure safety, toxicity, and pharmacokinetics Phase 2: small number of sick volunteers with disease of interest to measure treatment efficacy, optimal dosing, and adverse effects Phase 3: large number of randomly assigned either to treatment under investigation of to the best available treatment (or to placebo group to compare the new treatment to the current standard of care or placebo Phase 4: Postmarketing surveillance trial of patients after approval to detect rare or long-term adverse effects rash on arms and legs after camping trip in woods, edematous, erythematous rash with linear vesicles, activation of what cells? - ansT-lymphocytes -- Type IV hypersensitivity reaction with activation of Th1 cells after exposure to poison ivy Sildenafil MOA - ansInhibition of cGMP phosphodiesterase type 5 (PDE5)--> increased cGMP level --> drives smooth muscle relaxation in corpus cavernosum --> increased blood flow to penis Swimming in cold water up tot he neck. What happens to: - central blood volume - ADH - ANP - ans- Central blood volume: increased - ADH: decreased - ANP: increased symptoms of beriberi - ansperipheral neuropathy and weakness, muscle pain and tenderness, enlargement of the heart, difficulty breathing, edema, anorexia, weight loss, poor memory and confusion Symptoms of pellagra? - ans3 D's of niacin deficiency dementia, dermatitis, diarrhea, / death Symptoms of salicylate poisoning - ansearly: brain sx -tinnitus -vertigo -nausea/vomiting -resp alkalosis b/c taking deep breaths late: -hyperpyrexia -anion gap acidosis -obtunded NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. 15yo girl emigrated from India and with several lesions on neck for 2 weeks. Physical exam shows hypopigmented, hypoesthetic area on left side of forehead and 4-cm lesions on neck. Biopsy shows acid- fast bacilli. Best explanation why the organism results in dermal rather than visceral infections? - ansTemperature sensitivity Mycobacterium leprae is non-motile acid-fast bacili that likes cool temperature. Reservoirs is amadillos. Cutaneous nodules with hypopigmentation, erythematous plaques with central hypopigmentation, peripheral neuropathy, lion-like facies 16yo girl with intermittent fainting while standing. Plasma studies show undetectable NE/Epi concentration and marked increase in dopamine concentration when rising from a supine position to standing Deficiency in what enzyme? - ansDopamine B-hydroxylase A rare form of dysautonomia. Dopamine is released as a false neurotransmitter in place of NE and Epi 17yo woman just ran a marathon. 1 day later has SOB, weakness, muscle tenderness, fever, tachypnea, edema, pulmonary crackles. Cr 4, UA with 3+ protein and 4+ hemoglobin Release of what substance causes her symptoms? - ansMyoglobin Rhabdomyelysis -- Breakdown of muscles releases intracellular contents. Myoglobin causes renal tubular obstruction causing AKI, with proteinuria and myoglobinuria (which can be mistaken for hemoglobinuria) 25yo F with 3-year hx of irregular menses. Menarche was at age of 14 years. PE shows increased hair growth on the face and chest. Pelvic exam shows clitoromegaly and a normal-appearing uterus. Serum shows increased 17-hydroxyprogesterone and androstenedione. Deficiency of? - ans21-hydroxylase "Congenital adrenal hyperplasia" 25yo woman 6-month history of joint pain poorly responsive to aspirin. Physical exam: bilateral swelling of proximal interphalangeal joints, metacarpophalangeal joints, and wrists; weakness of grasp. Small nodules palpated beneath skin around joints of fingers. Dx? - ansRheumatoid arthritis 32yo M with 3-month hx of swelling and breast tenderness. Receiving thyroid hormone and steroid replacements since removal of pituitary adenoma 2 years ago. Began hCG injections 4 months ago. Most likely binding site of hCG causing gynecomastia? - ansTesticle --> estradiol production 35yo man with recurrent sinusitis and bronchitis throughout his life. One sister has similar history. Married with no children. Cardiac exam shows PMI on the right midclavicular 4th intercostal, hepatic margin on the left. Endoscopy shows nasal polyps, biopsy shows thickened, ciliated, pseudostratified epithelium with small patches of squamous metaplasia and mild lymphoid infiltration What disease and what structure would be missing on electron microscopy? - ansPrimary ciliary dyskinesia/Kartagener syndrome Dynein arms is missing or damaged --> cilia not working Triad of: situs inversus, chronic sinusitis, bronchiectasis For males, reduced fertility because low sperm motility NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. 38yo M with 1-week hx of watery, itchy eyes and a runny nose. Physical shows inflamed nasal mucosa. No congestion in lower lung. Pharmacotherapy? - ansLoratadine First gen H1 blocker has strong sedative action and anticholinergic effects, and not recommended for people operating heavy machineries. Second gen H1 blocker is non-sedative (Loratidine, Cetirizine, Azelastine, Fexofenadine) 40yo M with extreme sensitivity to sunlight. Exposure to sun causes formation of vesicles and blisters on skin, which takes weeks to heal. He is diagnosed with a disorder caused by increased synthesis of compounds in the skin that are subject to excitation by visible light. What pathway is defective? - ansHeme synthesis Porphyria cutanea tarda is caused by defect in uroporphyrinogen decarboxylase in heme synthesis --> accumulation of uroporphyrin 1 Sx: blistering cutaneous photosensitivity caused by hepatotoxic triggers (alcohol, estrogens). Most common type or porphyria 40yo M with interstitial pulmonary fibrosis has greater maximal expiratory flow rate than predicted. Which best explains this? - ansIncreased radial traction on airway The connective tissue that surrounds the airways of the lungs are called the parenchyma. This forms a sort of scaffold around the airways, keeping them open with a force known as "radial traction". Radial traction is the "spring" that bounce back to force air out. Fibrosis increases radial traction 44-year-old woman comes to the physician for a follow-up examination after two separate Pap smears showed atypical squamous cells of undetermined significance. Results of a molecular diagnostic test show the presence of the viral E6 protein of human papillomavirus. This protein is known to promote cell growth and malignancy by causing cellular p53 protein degradation. This degradation most likely begins when the p53 protein is targeted to which of the following types of cellular enzymes? - ansUbiquitin ligase protein degradation 56yo M 4 hours after sudden onset of uncontrollable irregular movements of the left side of the body. PE shows flailing movements of the proximal appendicular muscles on the left. Nuclei damaged? - ansRight subthalamic Hemiballismus is flinging/flailing movement of one side, caused by damage to the CONTRALATERAL subthalamic nucleus. Likely 2/2 to lacunar infarct 60yo M flow cytometry of peripheral lymphocytes show: CD3 50% CD4 40% CD8 10% CD20 50% Surface kappa 47% Surface lamba 3% What is predictive of a clonal lymphoid proliferation? - anssurface kappa:surface lambda ratio NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. Each plasma cell can only make either kappa or lambda. Normal ratio about 3:1. If one is much higher than the other, that means there is MONOCLONAL proliferation (instead of the normal polyclonal), such as in multiple myeloma 60yo M shipyard worker with progressive SOB pas 3 months. Xray of chest shows reticulonodular pulmonary infiltrates consistent with interstitial fibrosis. Microscopic exam of sputum shows occasional elongate structures (golden-brown fusiform rods). The fibrosis was most likely initiated by interaction of these structures with which cell type? - ansAlveolar macrophage Asbestosis - increased risk of bronchogenic carcinoma and mesothelioma 60yo M sudden onset of acute abdominal pain and tenderness, n/v, bloody diarrhea for 2 hours. History of cirrhosis and HCC. BP 99/50. Rigid abdominal pain with loss of bowel sounds. Half of small intestine is found to have a dark purple-red hemorrhagic appearance. What is the cause? - ansMesenteric venous thrombosis 60yo peanut farmer in China with sxs of hepatocellular carcinoma. No alcohol, negative Hep B/C. What is the cause? - ansAflatoxin (released by Aspergillus, contained in maize, peanuts, cotton seeds, tree nuts) 62yo M with pericardial friction rub 3 days after acute myocardial infarction. Cause of rub? - ansFibrinous pericarditis (Dressler syndrome) 65yo M emigrated from Brazil with 8-month history of shortness of breath and fatigue, edema of lower ext. CXR shows cardiomegaly. endomyocardial biopsy specimen shows myofiber necrosis with a mixed inflammatory infiltrate of PMNs, T lymphos, m.phages, and eosinophils. Causal org? - ansTrypanosoma cruzi 65yo woman with progressive vulvar itching not relieved with miconazole. Atrophy of labia minora and thin, parchment-like skin over vulva and around anus. Dx? - ansLichen sclerosus chronic inflammatory disease with characteristic white, atrophic plaques. Tx: topical steroids 68yo M difficulty swallowing solids, with history of dilated cardiomyopathy. Xray of esophagus with barium show indentation and posterior displacement of the esophagus. Enlargement of which heart chamber is the cause? - ansLeft atrium 70yo M from China has poorly differentiated monoclonal carcinoma of the nasopharynx. DNA probes of neoplastic cells most likely to detect what viral genome? - ansEBV A farmer is taking itraconazole for histoplasmosis acquired after contact with chicken coop. He still shows persistent symptoms despite 4 wks of therapy. Other medications include: HTCZ, enalapril, atenolol, omeprazole, metoclopramide. What drug causes lack of effect of itraconazole? - ansOmeprazole Itraconazole and other triazole antifungals comes in a capsule that requires acidic pH in the stomach to be absorbed in the duodenum. Omeprazole reduces acids --> low absorption of itraconazole NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. Missing CD55 causes what? - ansParoxysmal nocturnal hemoglobinuria Due to unregulated activation of complements leading to lysis of RBCs MOA of methyphenidate - ansIncreased release of dopamine and NE Name of opioid antidiarrheal agent with little or no ability to produce CNS effects? - ansLoperamide/diphenoxylase Agonist at mu opioid receptor Nasopharyngeal cancer is associated with what virus? - ansEBV Neural tube closure occurs when? - ansDay 15-40 (around 4 weeks average) NSAID use in patients with HTN and bilateral renal artery stenosis would have a bump in creatinine due to what mechanism? - ansInhibition of vasodilating prostaglandins at the afferent arteriole In contrast to ACEi/ARBs, which inhibit vasoconstriction at the efferent arteriole Odds ratio equation - ansOR = (ad)/(bc) Phases of clinical trials - ansPhase 1: small number of healthy volunteers to measure safety, toxicity, and pharmacokinetics Phase 2: small number of sick volunteers with disease of interest to measure treatment efficacy, optimal dosing, and adverse effects Phase 3: large number of randomly assigned either to treatment under investigation of to the best available treatment (or to placebo group to compare the new treatment to the current standard of care or placebo Phase 4: Postmarketing surveillance trial of patients after approval to detect rare or long-term adverse effects rash on arms and legs after camping trip in woods, edematous, erythematous rash with linear vesicles, activation of what cells? - ansT-lymphocytes -- Type IV hypersensitivity reaction with activation of Th1 cells after exposure to poison ivy Sildenafil MOA - ansInhibition of cGMP phosphodiesterase type 5 (PDE5)--> increased cGMP level --> drives smooth muscle relaxation in corpus cavernosum --> increased blood flow to penis Swimming in cold water up tot he neck. What happens to: - central blood volume - ADH - ANP - ans- Central blood volume: increased - ADH: decreased - ANP: increased NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. symptoms of beriberi - ansperipheral neuropathy and weakness, muscle pain and tenderness, enlargement of the heart, difficulty breathing, edema, anorexia, weight loss, poor memory and confusion Symptoms of pellagra? - ans3 D's of niacin deficiency dementia, dermatitis, diarrhea, / death Symptoms of salicylate poisoning - ansearly: brain sx -tinnitus -vertigo -nausea/vomiting -resp alkalosis b/c taking deep breaths late: -hyperpyrexia -anion gap acidosis -obtunded Treatment for PE and MOA? - ansHeparin -- potentiates the action of antithrombin III, which inactivates several factors. Warfarin -- inhibits hepatic synthesis of Vit K-dependent factors Treatment of inflammatory bowel disease and MOA? - ansInfliximab - TNF-alpha monoclonal antibody Mesalamine - 5-ASA (COX inhibitor) Sulfasalazine - Combo of 5-ASA (COX inhibitor) and sulfapyridine (suppress B cells) Uterine artery is a branch of what artery? - ansInternal iliac artery warfarin decreases what factors? - ansFactor II, VII, IX, X Protein C and S (which gets depleted first --> warfarin-associated tissue necrosis) What cancers is EBV associated with? - ansNasopharyngeal carcinoma in Asians Burkitt lymphoma in endemic areas CNS lymphoma in AIDS What cytokines are released to cause fever and inflammation? - ansIL-1 and TNF-a What diuretics should be used in addition to loop diuretic for pts with ascites - ansSpironolactone Actually more efficacious than loop diuretic in ascites. If use furosemide, then need to be used in conjunction with spironolactone What does the liver biopsy show in alcoholic liver disease? - ansneutrophil infiltration, hepatocyte ballooning and Mallory bodies/hyaline What happens to calcium level in sarcoidosis? - ansincreased serum calcium secondary to increased conversion of 25-hydroxyvitamin D (calcidiol) to 1,25-dihydroxyvitamin D3 (calcitriol) by 1-alpha hydroxylase produced by the macrophages of granulomas. NBME CBSE ACTUAL EXAM 200 QUESTIONS AND ANSWERS LATEST (USMLE STEP 1) MEDICAL EXAMINATION LATEST UPDATED MAY 2023 A+ GRADE. What is the mechanism of continued CK-MB and troponin I increase after coronary stenting? - ansMembrane lipid peroxidation (due to reperfusion injury which causes free radicals) What is the next step in newborn with possible fatty acid oxidation defect? - ansMeasure serum acylcarnitine concentrations Carnitine deficiency results in toxic accumulation of LCFA in the cytoplasm of myocytes and other cells. Patients present with hypoketotic hypoglycemia, fatty liver, myopathy, hypotonia, and fatigue. Treatment consists of oral supplementation of the amino acid carnitine. What kind of kidney stones cause staghorn calculi with urine pH=8? - ansStruvite (due to urease-producing bacteria -- Proteus mirabilis, Staph saphrophryticus, Klebsiella -- causing basic urine pH and precipitation of struvite) What marker to monitor thyroid cancer recurrence? - ansCalcitonin What month in normal child development includes using pincer grasp, finger feeding, standing while holding onto a table, and playing peekaboo? - ans9 months What tissue is choriocarcinoma made of? - ansTrophoblastic tissue Often presents after incomplete removal of hydatidiform mole, normal pregnancy, or abortion. Elevated B- hCG. Metastasize hematogenously commonly to lungs. Tx: methotrexate What two organs have gluconeogenesis - ansLiver and kidney Where is the AV node located? - ansinteratrial septum near the opening of the coronary sinus Where is the SA node located? - ansjunction of superior vena cava and right atrium Which vaccine cause conversion of T-independent antigens to T-dependent forms to enhance protection in young children? - ansH flu type b