uWorld 21 Flashcards
what is renal osteodystrophy
abnormal bone path seen in chronic kidney disease
PTH increase mobilizes calcium from bones by bone formation, causing OSTEOPENIA and pathologic bone changes similar to those seen in primary hyperthyroidism (OSTEOFIBROSA CYSTICA)
pts can also develop PTH resistance, resulting in low-turnover aplastic bone disease and OSTEOMALACIA
small intestinal bacterial overgrowth is characterized by what
overproduction of VITAMIN K and FOLATE, associated with nausea, bloating, abdominal discomfort, and malabsorption
B12, iron, zinc and fat soluble vitamins (except K) all decreased
what happens in the closed-ended gastroducodenal limb that occurs in a gastric bypass surgery
bacteria can proliferate (small intestinal bacterial overgrowth) and ferment any food that may be diverted into this segment
what enzyme plays a crucial role in imprinting
S-adenosyl-methionine (SAM)- a methyl donor
CYTOSINE methylation
what is an epigenetic process by which eukaryotic organisms modify genes expression without altering genetic code
DNA methylation (DNA methyltransferase)
methylation of cytosine-guanine dinucelotide repeats (CpGs) in the promoter region of genes effectively silences transcription of those genes
how does DNA methylation play a role in fragile X
methylation happens at CG repeats and fragile X is CGG trinucleotide repeats lead to hypermethylation of cytosine residues and FMR1 inactivation
what is epistasis
a phenomenon in which the allele of one gene affects the phenotypic expression of alleles in another gene
what is first-line treatment of major depressive disorder that DOES NOT cause sexual dysfunction
BUPROPION
norepi and dopamine reuptake inhibitor
also good for treating depression associated with hypersomnia and low energy
what is escitalopram
SSRI
what is a highly sedating antidepressant that can be helpful for patients with insomnia
TRAZODONE
the dorsal pancreatic bud forms what
pancreatic tail, body, most of the head, and the small ACCESSORY DUCT
the ventral pancreatic bud forms what
uncinate process, portion of the pancreatic head, and the proximal portion of the MAIN PANCREATIC DUCT
how is the main pancreatic duct (of Wirsung) created
fusion of the remainder of the accessory duct with the ventral duct
what is PANCREATIC DIVISUM
when ventral and dorsal pancreatic buds fail to fuse (usually occurs in week 8); the pancreatic secretions are instead drained via two separate duct systems
dominant dorsal duct (of SANTORINI) opens into the duodenum via the minor papilla, and is responsible for draining the majority of the pancreas
smaller ventral duct (of Wirsung) opens into he major papilla, and functions to drain the inferior/posterior portion of the head and unite process
how is pancreatic divisum diagnosed
can cause recurrent pancreatitis
normally incidental finding on imagining studies or at autopsy
what removes RNA primer as well as damaged DNA segments
5’ → 3’ exonuclease activity
what performs proofreading function that removes and replaces mismatched nucleotides on the newly formed daughter strands
3’ → 5’ exonuclease
defective in LYnch Syndrome (HNPCC)
what does an AP endonuclease do
cleaves 5’ end
used in base-excision repair
important repair of spontaneous/toxic deamination
how do nitrites cause poisoning
inducing conversion of heme iron into OXIDIZED ferric iron → methemoglobin formation
what does methemoglobinemia do to the skin and O2 in the blood
DUSKY discoloration (similar to cyanosis)
unable to carry oxygen, state of functional anemia is induced
pyruvate kinase deficiency causes what
chronic hemolytic anemia
splenomegaly
iron overload
result of impaired erythrocyte survival
what is acid maltase and what does a deficiency cause
ALPHA-1,4-GLUCOSIDASE deficiency Pompe Disease (type II glycogen storage disease)
cardiomegaly, macroglossia, hepatomegaly, and profound muscular hypotonia
blood glucose levels normal
abnormal GLYCOGEN ACCUMULATION in LYSOSOMES vesicles is seen on muscle biopsy
what is von Gierke disease (Type I glycogen storage disease)
GLUCOSE-6-PHOSPHATASE deficiency hepatomegaly and steatosis fasting hypoglycemia lactic acidosis hyperuricemia and hyperlipidemia
what is Cori Disease (type III glycogen storage disease)
DEBRANCHING ENZYME (alpha-1,4-transferase and alpha-1,6-glucosidase) deficiency
hepatomegaly
ketotic hypoglycemia
hypotonia and weakness
abnormal glycogen with very short outer chains
what is McArdle disease (Type V glycogen storage disease)
GLYCOGEN PHOSPHORYLASE deficiency
muscle phosphorylase deficiency
weakness and fatigue with exercise
no rise in blood lactate levels after exercise
glycogen accumulation within lysosomal vacuoles is specific for what glycogen storage disease
Pompe
acid alpha-glucosidase deficicency
what is the GERMINAL MATRIX
highly cellular and vascularized layer in the subventricualr zone from which neurons and glial cells mirgrare out during brain development
contains numerous thin-walled vessels lacking the glial fibers that support other blood vessels throughout the brain
what are the common complications of prematurity
respiratory distress syndrome patent ductus arteriosus bronchopulmonary dysplasia intraventricular hemorrhage (Germinal Matrix) necrotizing enterocolitis retinopathy of prematurity
intraventricular hemorrhage is a common complication of prematurity, where does it usually originate
GERMINAL MATRIX
vulnerable to hemodynamic instability as premature infants can have impaired autoregulation of cerebral blood flow
b/w 24-31 weeks gestation, germinal matrix becomes less prominent and its cellularity and vascularity decrease (reducing the risk of IVH)
berry aneurysms are associated with what disease states
Elhers-Danlos syndrome
AD polycystic kidney disease
how do infants get subdural hemotoma
rupture of cortical bridging veins
shaken baby syndrome (violent shaking)
what are the central effects of dopamine caused by L-dopa regardless of whether carbidopa is added to levodopa treatment
anxiety and agitation (hallucination, delusions, confusion, insomnia)
can actually be increased due to more dopamine in the brain
reducing dose can reverse these
how does carbidopa work
inhibits DOPA decarboxylase in the periphery
reduces arrhythmias, nausea, postural hypotension, hot flashes, and vomiting associated with levodopa
also increases compliance
where is concentration of PAH the lowest
Bowman’s Space (conc is similar to plasma)
majority is secreted in PROXIMAL TUBULE via carrier-mediated active transport
PAH is NOT REABSORBED by any portion of the nephron
what are the causes of erectile dysfunction
psychogenic stressors performance anxiety or depression mediaciones (SSRI, sympathetic blockers- methyldopa, clonidine, beta-blockers) vascular or neurological impairment genitourinary trauma (prostatectomy)
what is an important clue to psychogenic impotence
rapid onset
men who had no sexual difficulty until “one night when they could not have an erection” followed by persistent ED
NO LOSS OF MORNING WOOD
organic causes of impotence will complain of failure occurring intermittently and later became more persistence
in men what happens to sexual desire with age
does not decrease sexual desire
longer refractory period and take longer to get an erection
vasectomy does not cause ED but what medical conditions can
prostate surgery
pelvic trauma
priapism
1-week history of hemiplegia and expressive aphasia w/ CT showing hypo density in brain- what cell type would histological findings after staining for lipids lipids
MICROGLIA (come in 3-5 days after the onset of ischemia)
macrophages (microglia) phagocytize myelin and therefore stain for lipids
when are astrocytes seen in brain repair after ischemia
within 2 weeks of injury
as necrotic tissue is resorbed, a cystic space forms that is then surrounded by astrocytes and newly formed capillaries
enlargement and proliferation of astrocytes peripherally around the area of necrosis is called GLIOSIS (glial scare formation)
when are neutrophils seen following ischemia in the heart
24-48 hours after interruption of blood supply
do not phagocytize myelin remnants and therefore do not stain of lipids
what drug used for treating mixed hyperlipidemia can precipitate GOUT
NIACIN
decreases renal excretion of URIC ACID, leading to elevated blood levels and increased risk for ACUTE GOUTY ARTHRITIS
what is the most effective agent for RAISING HDL LEVELS
NIACIN
however, it has not been shown to reduce the risk of cardiac events, it is primarily used in patients who have failed other lipid-lowering drugs
what lipid lowering drug can cause hypertriglyceridemia
BILE ACID-BINDING RESINS
GI upset and impaired absorption of nutrients also seen
why lipid lowering drug can cause CHOLESTEROL GALLSTONES
FIBRATES
also severe myopathy w/ statins
what testing should patients with Zollinger Ellison (gastrinoma) undergo and why
serum calcium, prolactin levels, many more
MULTIPLE ENDOCRINE NEOPLASIA (MEN) TYPE I
what is a somatostatinoma
rare tumor of the pancreatic D cells that present with:
diabetes mellitus (diminished insulin secretion)
cholelithiasis (inhibition of CCK)
diarrhea/steatorrhea (inhibition of pancreatic enzyme/bicarbonate secretion)
what are the contact precautions (infection control measures) of MDR organisms (MRSA, VRE), enteric organisms (C. diff), and scabies
hand hygiene (SOAP AND WATER for C Diff)
NONSTERILE gloves
GOWN
private room preferred
dedicated BP cuff and stethoscope should be left in the pts room
what organisms require droplet precautions (wearing a simple facemark when within 6-10 feet of affected people)
Neisseria meningitides influenza Bordetella pertussis mycoplasma pneumonias RSV
gloves and gowns not required
what are and when would airborne precautions be used
isolated room with negative pressure ventilation and a respiratory mask with filtering capacity (N95 mask)
TB and varicella (respiratory droplets that chill in air for a long time)
the glossopharyngeal nerve proves general sensory to what
tympanic membrane (inner surface) eustachian tube posterior third of tongue tonsillar region upper pharynx (afferent portion of gag reflex) carotid body carotid sinus
what is the IFN-gamma release assay (IGRA)
test for LATENT TB infection by measuring the response of T lymphocytes when exposed to antigens unique to TB
similar to TB skin tests, measure cell-mediated immunity, but lack of BCG cross-reactivity
what findings suggest Toxo encephalitis in HIV patient
headaches, seizures, and multiple ring-enhancing CNS lesions
5 year-old with difficulty breathing, dysphagia, drooling, fever (103)
white count of 23,000 with many bands (left shift)
swollen and CHERRY-RED EPIGLOTTIS on laryngoscopy
da fuq he got?
H. flu
either not vaccinated or missed a vaccination
inspiratory STRIDOR
older children would have sore throat proly not dysphagia and fever
when prescribing opioids and suspecting abuse what should one do
validate the patients concern about pain control
engage the pt in a nonjudgmental, COLLABORATIVE DISCUSSION of how he is using the mediation; and EXPLORE REASONS for his ESCALATING USE
what is Crigler-Najjar syndrome type 1
AR disorder of bilirubin metabolism caused by genetic lack of UGT enzyme needed to catalyze bile glucuronidaiton
build up of UNCONGUJATED bilirubin that is BOUND to ALBUMIN
can cross BBB and cause KERNICTERUS (bilirubin encephalopathy)- potentially fatal causing jaundice and neuralgic impairment (rigidity, lethargy, seizures)
deficient bilirubin excretion into bile canaliculi is seen in what disease
DUBIN-JOHNSON SYNDROME (AR)
absence of biliary transport protein, MRP2 (multi drug resistance protein 2), used in hepatocellular excretion of bilirubin glucuronides into bile canaliculi
darkly pigmented liver and asymptomatic
conjugated hyperbilirubinemia
impaired canalicular bile transit is seen in what disease
ROTOR SNYDROME (AR)
asymptomatic conjugated hyperbilirubinemia
often jaundiced but normal life expectancies
what (and how) can anaerobes and Staph Aureus deconjugate bile acids
removal of glycine and taurine
results in lipid malabsorption b/c they less soluble and less able to form micelles
what is stercobilin
urobilinogens that remain in the colon and are excreted
contribute dark color to stool
exposure to aminoglycosides in utero can cause what
cranial nerve VIII problems
sensorineural hearing loss
vestibular instability and ataxia
what odes exposure to ACEI do to fetus
impaired fetal renal function and cause fetal anuria and oligohydramnios
what should be used to treat LYME in PREGNANT WOMEN
AMOXICILLIN
acute painless PERMANENT monocular vision loss is characteristic of what
CENTRAL RETINAL ARTERY OCCLUSION (CRAO)
vision loss includes entire visual field and is often permanent
fundoscopic findings: PALE RETINA (due to ischemia and edema) and CHERRY-RED MACULA (fovea and fovea are thin and have a separate blood supply from the choroid artery; red choroid is easily visible underneath))
what is the most common cause of central retinal artery occlusion (CRAO)
ATHERO- and THROMBOEMBOLISM
predisposing conditions are AFIB and CAROTID ARTERY STENOSIS or vasculitis (giant cell arteritis)
what is amaurosis fugax
painless, transient, monocular vision loss caused by a small embolus to the ophthalmic artery
usually does not last more than a few seconds
how does diabetic retinopathy manifest
blurry vision black spots floaters decreased peripheral vision acute visual loss may occur in the setting of a complication such a vitreous hemorrhage
NEOVASCUALRIZATION and HEMORRHAGE
temporal lobe stroke can cause what visual defects
MEYERS LOOOP (GENICULOCALCARINE TRACT) fucked up
carries impulses from the lower retina
can cause contralateral upper quadrantanopsia ("pie in the sky" visual defect)left frontal lobe lesions have an association with what
APATHY
DEPRESSION
right frontal lobe lesions have an association with what
DISINHIBITED BEHAVIOR
the frontal lobe is primarily responsible for what
EXECUTIVE FUNCTION (ability to perform complex tasks and includes motivation, organization, planning an d purposeful action) and PERSONALITY
lesions: social and emotional behavior, sexual disinhibition and emotional lability to apathy and depression
what happens when the corpus callous is injured
“split brain” syndrome
appear normal in general social situations but have inter hemispheric transfer of information
(pt unable to retrieve with one hand an object palpated with the other)
parietal lobe lesions result in what
difficulties with spatial and visual perception
non-dominant lobe lesions (most commonly right-sided) can realist in HEMI-NEGLECT, constructional APRAXIA, and DENIAL OF PROBLEM
dominant lesions (commonly left-sided): GERSTMANN SYNDROME w/ right-left confusion and difficulty with writing and mathematics (AGRAPHIA and ACALCULIA, FINGER AGNOSIA, LEFT-RIGHT DISORIENTATION)
what is Kluver-Bucy Syndrome
disinhibited behavior: hyperorality, hyperphagia, hypersexuality
bilateral amygdala lesion
associated with HSV-1 encephalitis
what happens with non dominant (usually right-sided) lesions of the temporal lobe cause what
affect nonverbal memory, including musical ability
what happens with dominant (usually left-sided) lesions of the temporal lobe cause what
verbal memory (word recognition)
it is recommended that tratemtn of friends occur when
only in EMERGENCY SITUAwTIONs when NO OTHER PHYSICIAN is AVAILABLE
the SMA and IMA are connected by what 2 anastomosis
MARGINAL ARTERY OF DRUMMOND (principal anastomosis) and inconsistency persistent ARC of RIOLAN (mesenteric meandering artery)
protect intestines from ischemia
what two arteries branch off the external iliac artery before it becomes the femoral artery
inferior epigastric artery
deep circumflex iliac artery
the IVC drains what part of the intestinwes
rectum (inferior and middle rectal veins drain into the internal iliac vein
cyclosporine is metabolized how
liver by CYP3A ISOENZYMES
grapefruit juice can slow the breakdown of drugs metabolized by this pathway
what is calcineurin inhibitor nephrotoxicity
new-onset hypertension and elevated levels of serum creatinine and cyclosporine
what suggests fat embolism
acute-onset NEURALGIC abnormalities
HYPOXIA
PETECHIAL RASH
seen in pts 24-72 hours after (but can be as much as 2 weeks) LONG BONE AND/OR PELVIC FRACTURE
when would one see a RED THROMBUS lodged in the pulmonary artery
thromboemoblim from a deep venous source
non neurologic impairment or petechial rash like w/ fat embolism
what should be started in all HF patients with left ventricular (LV) systolic dysfunction (decompensated systolic HF) to improve survival
BETA-BLOCKERS (carvedilol, metoprolol)
decreases cardiac work and levels of circulating vasoconstriction hormones (norepi, renin, endothelin)
not used in unstable HF and should be introduced slowly to avoid worsening of the patient’s condition by further impairing cardiac output
persistent back pain, fatiguability, constipation with atrophic tubules which contain large, obstructing, intensely eosinophilic, and elevated serum proteins casts suggests what
MULTIPLE MYELOMA
fatiguability (anemia)
constipation (hypercalcemia)
bone pain- back and ribs (bone lysis due to production of osteoclast-activating factor by myeloma cells)
elevated serum proteins (monoclonal proteins)
renal failure
AL AMYLOIDOSIS
what si myeloma cast nephropathy (“myeloma kidney”)
excess excretion of free light chains (BENCE JONES PROTEINS) is the most common form of nephropathy
the light chains precipitate with Tamm Horsfall protein and for casts that cause TUBULAR OBSTRUCTION and EPITHELIAL INJURY
deposition of light chain fragments in the glomerular mesangium and capillary loops can also cause renal failure (AL AMYLOIDOSIS)
hypersensitivity interstitial nephritis causes what
STERILE PYURIA
often ongoing exposure to an offending drug
eosinophilia and eosinophiluria may help confirm the diagnosis
how does ischemic tubular necrosis classically present
muddy brown, granular, and epithelial cell casts and free tubular epithelial cells in the urine
what does chronic lead intoxication due to the kidney
chronic tubulointerstitial nephritis (interstitial fibrosis and tubular atrophy seen on light microscopy) that leads to renal failure
