uWorld 49 Flashcards
hyper IgM is inherited in what pattern
X-LINKED RECESSIVE
problem in class switching (CD40-CD40L interaction)
sinopulmonary, GI, and opportunistic infections (Pneumocystis, Cryptosporidium)
what changes in B cell class switching
SPACING out DNA coding for different types of the HEAVY CHAIN CONSTANT REGION until the desired isotope is reached. the VARIABLE REGION, and therefore the antigenic specificity of the antibody, the the same
exceptions to confidentiality include what
suspected child or elder abuse
knife or gunshot wounds
diagnosing reportable communicable disease
threats to hear self or others and reasonable ability to carry out the threat in the near future
what happens to hormone levels in menopause
FSH INCREASED due to resistant ovarian follicles and lack of feedback inhibition
menopause is lack of menses for 12 months (average age is 51)
associated with HYPOESTROGENIC SYMPTOMS (hot flashes, vaginal dryness)
what are the main factors influencing CEREBRAL BLOOD FLOW
SYSTEMIC BLOOD PRESSURE
- above 150 causes ↑ cerebral BLOOD FLOW and ↑ ICP
- below 50 causes hypo perfusion and potential cerebral ischemia
ARTERIAL BLOOD GASS LEVELS
- DROP in PCO2 due to hyperventilation causes VASOCONSTRICTION, increasing VASCULAR RESISTANCE and reducing cerebral blood flow
- lowering PCO2 is one of the measures to REDUCE ICP in MECHANICALLY VENTILATED patients with CEREBRAL EDEMA
inducing sedation and therapeutic hypothermia can decreased BRAIN METABOLIC DEMAND, exerting what kind of effect
NEUROPROTECTIVE and improving ICP by reducing cerebral blood flow
what is the thecal sac
sheath of dura mater surrounding the spinal cord that contains CSF
increased ICP can cause displacement of CSP form the brain into the thecal sac
pCO2 has what effect on the brain
POTENT VASODILATOR of cerebral VASCULATURE
TACHYPNEA causes HYPOCAPNIA and cerebral VASOCONSTRICTION, thereby decreasing cerebral blood flow and intracranial pressure
what is seen histologically in reflux esophagitis
elongation of papillae
basal cell hypertrophy
intraepithelial eosinophils
fever, jaundice, anorexia, and IV drug use suggests what
VIRAL HEPATITIS
what is seen histologically in viral hepatitis
pan lobular lymphocytic infiltrates, ballooning hepatocytes, hepatocyte necrosis and hepatocyte apoptosis
apoptotic heptoctes form round ACIDOPHILIC bodies known as COUNCILMAN BODIES or apoptotic bodies
whats the only specific therapy known to reduce pulmonary vascular resistance
NITRIC OXIDE
what is the only ligament of the uterus that extends posteriorly
UTEROSACRAL ligament
pelvic splanchnic nerves run on top of it
what causes infertility in CF patients
ABSENT VAS DEFERENS bilaterally (AZOOSPERMIA)
what could cause the liver to appear shrunken and atrophies on autopsy in a patient who recently had surgery in a foreign country
DRUG-INDUCED LIVER INJURY from inhaled anesthetic (HALOTHANE, used in foreign countries still)
HEPATOCELLULAR PATTERN OF INJURY0 can range from mild asymptomatic ↑ LFT to FULMINANT HEPATITIS (50% mortality rate)
extensive haptocellular damage can cause the liver to rapidly atrophy and appear SHRUNKEN on autopsy
widespread CENTRILOBULAR NECROSIS and inflammation of the PORTAL TRACTS and PARENCHYMA are obsessed, making the condition indistinguishable from fulminant viral hepatitis
thought to be a hypersensitivity reaction to the drug that causes and immune-mediated attack against hepatocytes
fever, anorexia, nausea, myalgia, arthralgias, ↑ LFTS, PROLONGED PROTHROMBIN TIME, leukocytosis, eosinophilia
what happens to albumin levels in acute liver injury
NOTHING (20 day half life)
what drugs are associated with osteoporotic fractures
anticonvulsants that induce CYP450 (phenobarbital, phenytoin, carbamazepine)- ↑ Vitamin D catabolism
aromatase inhibitors, medroxypregestrerone- ↓ estrogen
GnRH agonists- ↓ testosterone and estrogen
PPIs ↓ calcium absorption
glucocorticoids, unfractioned hep, thiazolidinediones- ↓ bone formation
what defines a pathologic fracture
fracture due to a force significantly less than that required to fracture a normal bone
PROXIMAL TUBULAR cell BALLOONING and VACUOLAR DEGENERATION in a patient with acute renal failure is consistent with what
ACUTE TUBULAR NECROSIS
presence of OXALATE CRYSTALS in the tubular lumen is highly suggestive of what
ETHYLENE GLYCOL poisoning thus the damage and renal failure is due to TOXIC RENAL INJURY
what is hepatorenal syndrome
advanced liver disease with portal hypertension and ascites may causing renal failure
hallmark of this condition is RENAL VASOCONSTRICTION
histologically the kidney is NORMAL and function goes back to normal once the liver is transplanted
what is seen in ethylene glycol poisoning
TOXIC, acute tubular necoriss with VACUOLAR DEGENERATION and BALLOONING of the PROXIMAL TUBULAR cells
high anion gap metabolic acidosis
increased osmolar gap
calcium OXYLATE CRYSTALS in urine
MID-SHAFT humerus break will fuck up what nerve and artery
RADIAL NERVE
DEEP BRACHIAL ARTERY (aka profunda brachii artery)
the radial nerve innervates what msucles
FOREARM EXTENSORS (TRICEPS)
HAND EXTENSORS at the wrist
extensors of the digits
BRACHIORADIALIS and SUPINATOR MUSCLES
the brachial artery gets injured in what kind of injury
SUPRACONDYLAR FRACTURE (anteromedial displacement) or in the cubital fossa/distal humerus
with the MEIDAN NERVE
injury to the SURGICAL NECK of the HUMERUS may damage what artery and nerve
ACILLARY NERVE and POSTERIOR CIRCUMFLEX ARTERY
first pass elimination is based on what blood flow
LIVER BLOOD FLOW (not intestinal blood flow)
in coronary steal pneomenon drugs like adenosine of DIPYRIDAMOLE do waht
selectively VASODILATOR CORONARY VESSELS
causes redistribution of blood flow through collateral micro vessels and coronary arterioles that can reduce collateral blood flow
arterioles within ischemic areas already maximally delated prior to drug admin so vasodilation occurs in nonischmic areas only causing MORE ISCHEMIA
what kind of rash in seen in pseudomonas hot tub folliculitis
pruritic, papulopustuar rash
etoposide is a derivative of what
plant alkaloid podophyllotixin, targets topoisomerase II
whats the diff b/w topoisomerase I and II
topoisomerase I causes single-stranded nicks to relieve NEGATIVE supercoiling
topoisomerase II- induces transient breaks in BOTH DNA strands simultaneously to relive BOTH POSITIVE and NEGATIVE supercoiling
what drug blocks thymidylate synthase
5-FU
it does not work on DHFR thats methotrexate
irinotecan and topotecan do what
inhibit topoisomerase I (single-stranded breaks in DNA to relieve negative supercoiling
PNEUMATOSIS INTESTINALIS (air in the bowel- curvilinear areas of lucency that parallel the bowel wall lumen) in an infant with abdominal distention and BLOODY STOOLS is diagnostic for what
NECROTIZING ENTEROCOLITIS (NEC)
one of most frequent GI emergencies in newborns (mainly PRETERM INTENTS secondary to GI and immunologic immaturity)
upon feeding bacteria proliferate excessively and impaired mucosal barrier function allows the bacteria to invade the bowel wall, causing inflammation and ischemic necrosis of terminal ileum and colon
bowel becomes congested and gangrenous with the formation o INTRAMURAL GAS COLLECTIONS
30% die but survivors at risk for STRICTURES and BOWEL OBSTRUCTION
what type of epithelium is found in the different parts of the female reproductive tract
ovary- simple cuboidal i.e. germinal (rapidly proliferate to pre air ovulatory surface defects)
fallopian tube- simple columnar (ciliated cells transport egg/embryo, damage can cause infertility, hydrosalpinx, entropic pregnancy)
uterus- simple columnar (stratum FUCNTIONALIS sloughs off during menstruation, prolonged estrogen exposure prevents shedding- hyperplasia/malignacny)
vagina- stratified squamous non-keratinized (maintains acidic environment to prevent infection)
cervix:
- ectrocervis: stratified squamous non-keratinized
- endocervix: simple columnar
- cervical glands secrete mucus- (thin and watery during ovulation, mucus plug in pregnancy)
- HPV infraction predisposes to cervical malignancy
what bugs are pyrrolidonyl arylamidase (PYR) positive
Strep progenes
enterococci
describe HEREDITARY OROTIC ACIDURIA
AR disorder of de novo pyrimidine synthesis
defect in URIDINE 5’MONOPHOSPHATE (UMP) SYNTHASE
PHYSICAL and MENTAL RETARDATION (low height/weight, developmental milestones)
MEGALOBLASTIC ANEMIA
elevated urinary OROTIC ACID levels (also seen in ornithine transcarbamylase deficiency but they would also have failure to thrive and hyperammonemia encephalopathy from impaired urea synthesis)
TX: URIDINE SUPPLEMENTATION bypasses this enzymatic defect and improve symptoms as uridine is covered to UMP via nucleoside kinases
rheumatoid arthritis affects what part of the spine
CERVICAL SPINE (leading to SPINAL INSTABILITY and potentially to radiculopathy and cord compression)
arthritis in the thoracic and lumbar spine are usually due to what
thoracic: osteoarthritis or spondyloarthritis
lumbar: osteoarthritis
what electrolyte changes are seen in PRIMARY ADRENAL INSUFFICIENCY (ADDISON)
HYPERKALEMAI
HYPONATREMIA
HYPERCHLOREMIA
non-anion gap METABOLIC ACIDOSIS
horners syndrome can occurs from lesions where
lateral hypothalamus
hypothalamospinal tract
superior cervical ganglion (pan cost tumor)
internal carotid artery (carotid dissection)
rubber, amine-containing dyes, textiles, leather industry work puts you at higher risk for what kind of cancer
BLADDER
what are the risk factors for great cancer
early menarche
late menopause
NULLIPARITY
BRCA mutations
charred or fried foods as well as obesity put you at risk for what cancer
COLORECTAL
so does HNPCC, FAP, IBD
hemochromatosis put you at risk for what cancer
LIVER
so does Hep B and C, liver cirrhosis (any cause), aflatoxin
what is WHIPPLES TRIAD (symptomatic hypoglycemia)
symptoms of hypoglycemia( tremor, diaphoresis, confusion)
low blood glucose level
relief of hypoglycemic symptoms when the blood glucose is increased
what are brown and black pigment stones
BROWN: associated with biliary tract infections (microbes producing beta-glucoronidases)
BLACK: occur in setting of chronic hemolytic anemia (sickle cell disease) and increased enterohepatic cycling of bilirubin (Crohns disease)
what is biliary sludge
due to gallbladder HYPOMOTILITY
biliary STASIS results in bile concentration, promoting bile precipiaiotn and at the accumulation of particulate material (cholesterol monohydrate crystals, calcium bilirubinate, mucus)
know precursor to stone formation (especially cholesterol stones) and may be complicated by biliary colic, acute cholecystitis, cholangitis, and pancreatitis
what are risk factor for gallbaldder hypomotility and thus biliary sludge
pregnancy
rapid weight loss
high spinal cord injuries
prolonged use of total parenteral nutrition or octreotide
what is intertrigo
well-defined erythematous plaques with satellite vesicles or pustules in warm, moist skin areas (axillae, groin, skin folds)
usually do etude candida
what contributes to formation of PE
VIRCHOW TRIAD:
endothelial cell injury
venous statin
HYPER COAGULABLE STATE (particularly due to cancer)
crutch or satruday night palsy fucks up what nerve
RADIAL (proximal injury)
weakness or paralysis or forearm, hand, and finger EXTENSOR MUSCLES (wrist drop, absent triceps reflex)
(mid shaft humerus breaks spare the triceps)
a ventiatlion defect matched by a perfusion defect (matched defect) usually indicates what
lung collapse or consolidation
if its not matched (PE)
how does mismatch repair work
- starts with MutS homolog detecting mismatch on newly created daughter strand (done by creating nicks in the phosphodiester bonds)
- MutL homolog then recruited and slides along the DNA until it finds one of the nicks in the daughter strait
- EXONUCELASE 1 is then loaded onto and activated by the repair complex degrading the daughter strand BACKWARDS past the initial mismatch point, leaving a variable gap of ss-DNA the is stabilized by DNA-binding protein
ionizing radiation fucks DNA up how, what fixes it
double stranded breaks
repaired via end joining mechanisms (non-homologous is prone to more mutations than homologous recombination)
what is INSULITIS
infiltration of islet cells by inflammorty cells in early stages of T1DM
cell-mediated immunity causes destruction of beta islet cells not the antiboeis that are foudn
what is maturity-onset diabetes of the young
AD disease caused b mutations in GLUCOSE SENSING and INSULIN SECRETION by pancreatic beta cells
no-insulin dependent diabetes at a tong age (less than 25)
