Uworld 8 Flashcards
What is seen on duodenal biopsy for celiac disease?
crypt hyperplasia, villous atrophy, and intraepithelial lymphocyte infiltration.
What is amyloid precursor protein? (APP) What happens with abnormal APP processing?
APP gene is located on c.21 and encodes a cell-surface protein that can be degraded into beta amylid.
Abnormal APP processing, impaired beta-amyloid clearance, and production of higher levels of APP are associated with the increased formation of the neurotoxin plaques that characterize ALzheimer dementia.
MOA of selective serotonin reuptake inhibitors
Inhibition of serotonin reuptake by blocking the serotonin transporter
What is the main adverse effects seen with nitrate therapy?
Headache and cutaneous flushing along with lightheadedness and hypotension due to systemic vasodilation
The great saphenous vein drains into?
Th femoral vein within the region of the femoral triangle, a few centimeters inferolateral to the pubic tubercle.
The great saphenous vein is a superficial vein of the leg that originates on the medial side of the foot, courses anterior to the medial malleolus, and then travels up the medial aspect of the leg and thigh.
Oncogenesis in pancreatic ductal adenocarcinoma is almost always due to?
An early activating mutation in the KRAS oncogene, which produces a constitutively active protein that allows for uncontrolled proliferation of tumor cells.
What is obstructive sleep apnea due to?
Due to relaxation of oropharyngeal muscle tone with occlusion of the upper airway.
Sx: daytime sleepiness, headaches, and depression.
Complications: systemic and pulmonary HTN, right heart failure, and an increased risk for cardiac events
CMV can cause what in AIDS patients?
CMV is a common cause of colitis in patients with advanced AIDS.
It is the second most common CMV reactivation disease in this population (CMV retinitis is the most common).
Patients with CMV colitis often have abdominal pain, fever, diarrhea, and weight loss.
Colonoscopy usually shows erythema, erosions, and ulcerations; colonic biopsy typically reveals large cells with prominent basophilic intranuclear inclusions.
Protease inhibitors block?
viral protease from cleaving gag-pol polyproteins, which results in the formation of immature virions that are noninfectious.
Decompensated heart failure is a common cause of which murmur?
Common cause of secondary (functional) mitral valve regurgitation.
Increased left ventricular end-diastolic volume causes dilation of the mitral vale annulus and restricted movement of the chordae tendineae with subsequent regurgitation.
Txt: diuretics and vasodilators can improve heart failure induced MR.
What is a common side effect of atropine?
increased intraocular pressure.
It may precipitate acute closed-angle glaucoma in susceptible individuals.
Atropine is indicated for the txt of?
Bradycardia as it decreases vagal influence on the SA and AV nodes
Hepatic encephalopathy is caused by?
Increased levels of ammonia and other neurotoxins in the circulation that lead to increased inhibitory neurotransmission and impaired excitatory neurotransmitter release.
Frequently precipitated by a stressor (eg, GI bleeding, infx) that increases blood ammonia levels.
What response does inactivated (killed or component) viral vaccines primarily generate?
Primarily generate a humoral immune response against extracellular viral antigens, preventing viral entry into the cell.
Live attenuated viral vaccines can generate what kind of response?
A strong cell mediated immune response that can kill virally-infected cells, in addition to providing humoral immunity.
Pain due to diabetic neuropathy may be difficult to control and require multiple medications. To reduce the risk of adverse effects and improve pain control, medications should work through different mechanisms. One such combination may include?
a tricyclic antidepressant (eg nortriptyline) and an anticonvulsant (eg, gabapentin)
Mutations in factor V Leiden predisposes to?
Heterozygote carriers of a mutation in factor V Leiden, which is modified to resist activated protein C, have a hypercoagulable state that predisposes to deep vein thromboses (the source of most pulmonary emboli)
Malignant pleural effusions are usually exudative by Light criteria and can occur via several mechanisms, including?
An inflammation-induced increase in vascular permeability (leading to increased inflow) and blockage of pleural fluid reabsorption by parietal pleura lymphatics (leading to decreased outflow)
S3, a third heart sound occurs due to?
Sudden limitation of ventricular movement during passive ventricular filling in diastole.
An S3 in patients age>40 suggest?
abnormal ventricular cavity enlargemnt such as occurs in chronic severe mitral regurg, chronic aortic regurg, or dilated cardiomyopathy
Transudative effusions are characterized by?
Low protein and lactate dehydrogenase content compared to serum values.
Heart failure can cause what type of pleural effusion?
Transudative pleural effusion due to an increase in pulmonary capillary hydrostatic pressure
Burkitt lymphoma is associated with which translocation?
Translocations of the MYC gene on chromosome 8 to the immuniglobin heavy chain region of c.14 (t8;14), resulting in MYC over expression.
Presents with rapidly growing mass (eg, jaw) and histo: starry sky appearance, with numerous mitotic figures and apoptotic bodies
Pregnant women with severe preelampsia can develop?
HELLP (hemolysis, elevated liver enzymes, low platelet count) syndrome.
Nausea/vomitting and RUQ pain occur due to liver ischemia and/or hemorrhage (eg subcapsular hematoma).
Also at risk for seizure, renal insufficiency, and disseminated intravascular coagulation due to widespread endothelial dysfunction
What is the MOA of class IC antiarrhythmics such as flecainide?
Potent sodium channel blockers that have increased effect at faster heart rates (use-dependence).
This makes them more effective at treating tachyarrhythmias, but can also cause prolonged QRS duration (a proarrhythmic effect) at higher heart rates
What is asthma characterized by?
Chronic airway inflammation, which leads to airway remodeling, airway hyperresponsiveness, and bronchoconstriction.
Treatment for asthma
Corticosterioids reduce airway inflammation and are used for both chronic asthma management (inhaled adminstration) and acute exacerbations (systemic adminstration).
What are the most prominent organisms in intraabdominal infections?
Bacteroides fragilis and E. coli
Cardiac auscultation in patients with mitral stenosis reveals?
A loud first heart sound, an early diastolic opening snap after the second heart sound, and a low-pitched diastolic rumble best heard at the cardiac apex
The opening snap is caused by the sudden opening of the mitral valve leaflets when the left ventricular pressure falls below the left atrial pressure at the beginning of diastole.
ACTH regulates which zones in the adrenal?
ACTH is the major trophic hormone of the zona fasciculata and reticularis
Zona glomerulosa is regulated by?
angiotensin II
Excess production of ACTH causes?
increased cortisol synthesis within the zona fasciculata (Cushing’s manifestations) and increased androgen production within the zona reticularis (irregular menstruation, hirsutism in women)
A deformation anomaly is caused by?
Abnormal extrinsic forces on a developing fetus.
Talipes equinovarus (clubfoot) is an anomaly in which the foot is plantarflexed and pointed inward due to restricted in utero movement.
Transudative pleural effusions result from?
Increased intracapillary pressure (eg, heart failure)
Exudative effusions develop from?
Inflammatory disruption of the vascular membrane
What are the labs for transudative pleural effusions?
Transudative pleural effusions have low fluid/serum ratios of total protein and lactate dehydrogenase and low absolute levels of lactate dehydrogenase compared to exudative effusions
Methanol and ethylene glycol have relatively little direct toxicity (similar to ethanol) but are metabolized into highly toxic compounds by alcohol and aldehyde dehydrogenase. Treatment involves?
Adminstration of fomepizole, a competitive inhibitor of alcohol dehydrogenase (increases Km without reducing Vmax)
Parkinson disease is caused by?
bradykinesia, resting tremor, and rigidity are features of Parkinson disease, which is caused by dopaminergic neurodegeneration.
Traumatic brain injuries can accelerate neurodegeneration, leading to a higher incidence and earlier onset of Parkinson disease
Acute cardiac transplant rejection usually occurs weeks to months following transplantation and is primarily a cell-mediated process. In acute cellular rejection, endomyocardial biopsy shows?
An interstitial lymphocytic infiltrate with myocyte damage.
What is renal ammoniagenesis?
Acidosis stimulates renal ammoniagenesis, a process by which renal tubular epithelial cells metabolize glutamine to glutamate, generating ammonium that is excreted in the urine and bicarbonate that is absorbed into the blood.
This process is responsible for the vast majority of renal acid excretion in chronic acidotic states.
