Uworld30 Flashcards
What is xeroderma pigmentosum?
develops due to a defect in nucleotide excision repair. This disease is characterized by increased sensitivity to ultraviolet radiation and a high incidence of cutaneous malignancy
What is the Romberg test?
a test of proprioception in which patients are observed for unsteadiness as they stand with their feet close together, arms to the sides, and eyes closed.
Failure to maintain this posture indicates sensory ataxia, which may be caused by defects in the posterior column or peripheral nerves (eg, tabes dorsalis, vitamin B12 def)
What is a bicuspid aortic valve?
a common cause of aortic stenosis in the US.
The classic auscultation of aortic stenosis is a harsh, crescendo-decrescendo systolic ejection murmur best heard at the right upper sternal border with radiation to the carotids.
What is cerebral palsy?
a non progressive neurologic injury that most commonly presents with delayed gross motor milestones, spasticity, and hyperreflexia. Premature infants are particularly susceptible due to periventricular leukomalacia (white matter necrosis)
In chronic obstructive pulmonary disease, air trapping leads to?
an increase in residual volume and total lung capacity, and increase in RV/TLC ratio.
Airway obstruction causes a decrease in forced vital capacity, forced expiratory volume in 1 second, and the FEV1/FVC ratio.
What is IgA nephropathy (Berger disease)
frequently presents as recurrent, self limited, painless hematuria; episodes often occur concurrently with an upper respiratory tract infection.
Kidney biopsy will show mesangial IgA deposits on immunofluorescence.
In contrast, poststreptococcal glomerulonephritis is seen 1-3 weeks after streptococcal pharyngitis and is usually not recurrent.
Pancreatic zymogens are normally converted into their active for by?
trypsin in the duodenal lumen.
Premature cleavage of trypsinogen to trypsin within the pancreas leads to uncontrolled activation of these zymogens, causing pancreatic autodigestion and acute pancreatitis.
MOA of 5-alpha reductase inhibitors (eg, finasteride, dutasteride)
block the conversion of testosterone to dihydrotestosterone in the prostate. These drugs reduce prostate volume in patients with benign prostatic hyperplasia and relieve the fixed component of bladder outlet obstruction.
Warfarin inhibits?
proteins C and S (natural anticoagulant present in blood), which can lead to skin necrosis, particularly in patients with protein C or S deficiency. This complication is usually seen in the first few days of warfarin therapy.
What is ductal carcinoma in situ?
The terminal duct lobular unit is the functional unit of the breast and the site of origin for most breast carcinomas.
Ductal carcinoma in situ is characterized by neoplastic epithelial cells (sometimes with pleomorphism and central necrosis) that fill the ducts/lobules.
What is trazodone?
a highly sedating antidepressant commonly used to treat insomnia.
Priapism is a rare but serious adverse effect.
What is responsible for biliary stones in patients with somatostatinoma?
Reduced gallbladder contractility, due to decreased cholecystokinin secretion, is responsible for biliary stones in patients with somatostatinoma.
What is colonic diverticula?
often involve the sigmoid colon and develop due to exaggerated contractions of colonic smooth muscle segments.
This results in increased intraluminal pressure, causing outpouching of the mucosa and submucosa through the muscularis (false diverticula).
Individuals (typically age>60) may be asymptomatic or have hematochezia or diverticulitis.
What is the difference between duodenal ulcers and ones in the stomach?
Duodenal ulcers are not associated with an increased risk of carcinoma in the same location.
In contrast, ulcers located in the esophagus, stomach (gastric), and colon may be malignant, and biopsy is required.
Where does the testes and scrotum drain?
Due to its intra-abdominal origin, lymphatic drainage of the testis is to the para-aortic lymph nodes.
Lymph drainage from the scrotum goes into the superficial inguinal lymph nodes.
Drug induced parkinsonism is an extrapyramidal side effect caused by meds that?
block D2 receptors (eg, antipsychotics).
Management strategies include decreasing or discontinuing the offending medication and treatment with an anticholinergic medication.
What is correlation analysis?
a statistical technique used to describe the strength and direction of a linear relationship between 2 quantitative variables.
What is diverticulitis?
characterized by inflammation of colonic diverticula. Patients have abdominal pain, nausea, vomiting, and changes in bowel habits. Low grade fever and leukocytosis are common, and physical examination may demonstrate a tender mass in the left lower quadrant.
What is xeroderma pigmentosum?
an autosomal recessive disorder characterized by defective nucleotide excision repair often caused by a deficiency in UV-specific endonuclease.
Affected children usually have severe photosensitivity, hyperpigmentation in sun-exposed areas, and a greatly increased risk for skin cancer.
What alzheimer disease?
a progressive dementia featuring diffuse cortical atrophy involving loss of cholinergic neurons.
Memory, cognitive, and functional impairments of AD are partially mediated by insufficient cholinergic output.
Cholinesterase inhibitors (eg, donepezil) enhance cholinergic neurotransmission to compensate for this defect.
The rubber-like properties of elastin are due to?
high content of nonpolar (hydrophobic) amino acids and extensive cross-linking between elastin monomers facilitated by lysyl oxidase.
Patients with alpha-1 antitrypsin deficiency can develop early onset, lower lobe predominant emphysema due to excessive alveolar elastin degradation.
What is central hypothyroidism?
low serum TSH and thyroxine (T4) levels and is due to hypothalamic-pituitary dysfunction.
What is Sheehan syndrome?
ischemic necrosis of the pituitary gland and is typically caused by systemic hypotension during delivery.
In addition to central hypothyroidism, patients may also develop deficiencies of other pituitary hormones (eg, ACTH, prolactin, gonadotropins).
What is the paired t-test?
compares with mean of 2 related groups. The test requires that a quantitative dependent variable (ie, outcome) be evaluated in 2 related (ie, matched, paired) groups.
What is refeeding syndrome?
occurs after the reintroduction of carbohydrates in patients with chronic malnourishment, which stimulates insulin secretion and drives phosphorus intracellularly in an effort to maintain cellular energy metabolism (eg, ATP production); this redistribution of phosphorus can result in severe hypophosphatemia.
Acute cardiogenic pulmonary edema results from?
increased pulmonary venous pressure. The alveolar capillaries become engorged with blood and there is a transudation of fluid plasma across the alveolar-capillary membrane, appearing pink, acellular material within the alveoli.
What is oral (PO) bioavailability?
is calculated by dividing the area under the PO curve by the area under the IV curve.
Bioavailability refers to the fraction of administered drug that reaches the systemic circulation. For a drug administered by any route other than IV, bioavailability is usually less than 100%.
What is the second most common cause of severe combined immunodeficiency?
autosomal recessive deficiency of adenosine deaminase, an enzyme necessary for the elimination of excess adenosine within cells.
Toxic levels of adenosine accumulate within lymphocytes in this condition, leading to lymphocyte cell death and resultant cellular and humoral immunodeficiency. Patients with this condition can be treated with hematopoietic cell transplantation or gene therapy.
What is bronchopulmonary dysplasia?
common in premature infants due to arrest of fetal lung development in the saccular stage.
histo: impaired alveolarization (ie, dilated alveoli with decreased septation) and abnormal vasculogenesis (ie, dysmorphic alveolar capillaries)
What is multiple sclerosis?
an autoimmune disorder of the central nervous system characterized by recurrent episodes of demyelination, leading to reduced saltatory conduction.
Internuclear ophthalmoplegia and optic neuritis are common manifestations.
What is the function of LH and FSH in men?
LH stimulates the release of testosterone from the Leydig cells of the testes; FSH stimulates the release of inhibin B from the Sertoli cells in the seminiferous tubules.
Testosterone and inhibin B induce negative feedback on LH and FSH production, respectively.
The release of prolactin is under inhibitory control by?
dopamine secretion from the hypothalamus. Disruption of dopaminergic pathways or blockade of dopamine D2 receptors can cause hyperprolactinemia.
What is antiphospholipid antibody syndrome?
Many patients with systemic lupus erythematosus have antiphospholipid antibodies, which can cause paradoxical PTT prolongation and false-positive RPR/VDRL results; antiphospholipid antibody syndrome is characterized by arterial or venous thrombosis and increased obstetric morbidity (eg, recurrent pregnancy loss)
What is Osler-Weber-Rendu syndrome (hereditary hemorrhagic telangiectasia)?
an autosomal dominant condition marked by the presence of telangiectasias in the skin as well as the mucous membranes of the lips, oronasopharynx, respiratory tract, gastrointestinal tract, and urinary tract.
Rupture of these telangiectasias may cause epistaxis, gastrointestinal bleeding, or hematuria.
MOA of ipratropium
Ipratropium, an anticholinergic agent and derivative of atropine, treats obstructive lung disease by blocking acetylcholine at muscarinic receptors, which prevents bronchoconstriction and reduces mucus secretion from tracheobronchial submucosal glands.
What is depersonalization/derealization disorder?
a dissociative disorder involving recurrent episodes of feeling detached from one’s body or surroundings and/or feelings of unreality.
What is the treatment of organophosphate poisoning?
Organophosphates inhibit acetylcholinesterase, leading to symptoms of muscarinic and nicotinic (neuromuscular dysfunction) cholinergic hyperstimulation.
Management includes atropine, a competitive inhibitor of acetylcholine at the muscarinic receptor (reverses muscarinic symptoms), followed by pralidoxime, a cholinesterase-reactivating agent that treats both nicotinic and muscarinic symptoms.
What is spasticity?
Spasticity can be caused by the loss of descending inhibitory signals from upper motor neurons, leading to a hyperactive stretch reflex that results in increased muscle tone.
Disruption of the afferent (sensory) arm of the stretch reflex through a selective dorsal rhizotomy can improve spasticity without causing paralysis.
What is liquefactive necrosis?
characterized by complete digestion and removal of necrotic tissue with formation of a cystic cavity.
Irreversible ischemic CNS injury is typically followed by liquefactive necrosis due to the release of lysosomal enzymes from inflammatory cells and damaged neurons.
What is tubal factor infertility?
Tubal factor infertility, which occurs due to tubal scarring and obstruction, is a complication of pelvic inflammatory disease.
The risk for permanent tubal scarring increases with inadequate antibiotic treatment due to persisting or prolonged infection of the upper genital tract.
