test #38 4.28 Flashcards
triple test (maternal serum)
- AFP
- estriol
- hCG
between weeks 16-18
abnormal values –> ultrasound
if no abnormalities found –> amniocentesis
AFH in triple test? elevated? low?
synthesized by fetal liver, GI tract, and yolk sac (early gestation only).
maternal serum aFP levels increase w/ gestation age
elevated:
- dating error (underestimation)
- neural tube defects
- anterior abdominal wall defects (omaphalocele, gastrochisis)
- multiple gestatoin
decrease: Down’s syndrome
most common cause of elevated AFP in triple test?
dating error (underestimation of gestational age).
confirm w/ ultrasound
estriol levels in triple test? decreased levels suggest?
reflect placental and fetal function (both necessary for synthesis)
decrease:
1. placental insufficiency
hCG in triple test? increased levels associated w/?
synthesized by trophoblastic tissue.
increased levels:
- multiple gestation,
- hydatidiform mole,
- choriocarcinoma
- down’s syndrome
placental abnormalities & intrauterine growth retardation are associated w/ decreased..
estriol
placental insufficiency!
infection, pain, and sleep deprivation all increase..
blood glucose!
stress: increase catecholamines
decreased insulin, increase glycogenolysis, increased gluconeogenesis
isolation (defense mechanism
removing disturbing feelings from an event.
combat veterans who describes friends dying in cold and distant tones. isolating the fear and sadness from event
bifid carotid pulse w/ brisk upstroke “spike & dome” associated w.
hypertrophic obstructive cardiomyopathy
collapse in pulse, followed by secondary rise
three cytogenetic abnormalities that can lead to downs syndrome
- trisomy 21: meotic nondisjunction (usu mama)
- unbalanced robertsonian translocations (2-3%)
- normal number of chromosomes, but extra arm of chromosome 21 is attached to another chromosome - mosaicism: one w/ normal genotype, one with trisomy 21
- postfertilization mitotic error
uniparental disomy
when fetus inherits two copies of homologous chromosomes from one parent and no copy from other parent
(occurs in complete hydatidiform mole)
consider when child inherits a recessive condition when only 1 parent is carrer
heterodisomy and isodisomy
heterodisomy: uniparental disomy in meiosis I
isodisomy (homozygous): in meiosis II or postzygotic duplicatino of one & deletion in one
cytokines involved in asthma
IL4: class-switch to IgE
IL5: recruit eosinophils
IL10: block Th1, encourage Th2
charcot-leyden crystals
asthma sputum: eosinophil membrane protein
TGF-beta is important for..
tissue regeneration and repair
anti-inflammatory cytokines
IL-10 and TGF-beta
loss of CNIII to the eye results in.. (3)
somatic:
1. ptosis (levator palpebrae)
2. down & out (only maintain superior oblique and lateral rectus)
- loss of iris spincter
(fixed dilated) - loss of acommodation
describe light pathway (reflex)
afferent in one eye:
ipsilateral optic nerve -> bilateral post optic chiasm -> bilateral pretectal area -> bilateral edingerwestphal nucleus
efferent:
bilateral edingerwestphal nucleus -> travel w/ oculomotor n -> bilateral ciliary ganglion -> bilateral pupillary sphincter
2 ways to get lung abscess
- aspiration of oropharyngeal contents (most common)
2. right sided endocarditis -> septic emboli
Marcus Gunn pupil
defect in CN II
“swinging flashlight test”
affected eye will have consensual pupillary constriction, but will appear to ‘dilate’ when light is on affected eye
– can’t detect light
differentiate lesion in LGN and optic tract
both will have contralateral hemianopsia
optic tract: has Marcus Gunn pupil (loss of direct pupillary constriction w/ light)
LGN: light reflex should be fine (does not go through LGN, instead straight to pretectal -> edingerwestphal -> ciliary ganglion -> iris sphincter
Marcus-Gunn pupil in optic nerve lesion? optic tract?
optic nerve: marcus gunn pupil when light is shone into affected eye (IPSILATERAL relative afferent pupillary defect)
optic tract: marcus gunn pupil when light is shone on eye CONTRALATERAL to side of lesion.
bc nasal fibers contribute more to prectal afferents. optic tract will have more contralateral ‘nasal’ fibers. less afferents
both have contralateral homonymous hemianopsia
rabies virus is..
killed vaccine
Live vaccines (6)
live! small yellow chickens get vaccinated w/ mmr and sabin’s polio! it’s INcredibly
- smallpox
- yellow fever
- VZV chicken pox
- MMR (measles, mumps, rubella)
- sabin’s polio (IgA and IgG)
- infuenza intranasal
Killed vaccines (4)
SalK = killed
RIP Always
- rabies
- influenza (intramuscular)
- salk polio
- hepatitis A
recombinant vaccines (2)
- HBV (recombinant HBsAg)
2. HPV (6, 11, 16, 18)
path of rabies viruses
deposit in wound:
rabies binds to nicotinic AchR in striated muscle -> binds NCAM -> enters motor neuron // DRG?
- rabies virus travels retrograde via peripheral nerves to DRG
- then to brain
- massive replication in CNS
- rabies then spreads to other organs via neural pathways
recommendation for rabies vaccine
prophylatic for certain populations: veterinarians, 30+ days in country w/ lots of rabid dogs)
inactivated (killed) virus w/ beta-propiolactone
clinical presentation of rabies
restlessness, agitation, dysphagia progressing to coma 30-50 days following exposure
chromosome of NF2
chr. 22
chromosome of p53
chr. 17
breast, sarcoma, brain tumor, leukemia, adrenocortical tumor
gene implicated in NF-1
von Reclinghausen disease, chr. 17
tumor supressor gene: neurofibromin
(cafe au lait, neurofibromas, lisch nodules)
gene implicated in NF-2
central neurofibromatosis, chr. 22
tumor supressor gene: merlin
bilateral acoustic neuromas
chromosome of APC
chr. 5
chromosome of Rb
chr. 13
osteoscarcoma, retinoblastoma
chromosome of VHL
chr. 3
renal cysts, renal cell carcinoma, hemangioblastoma of cerebellum and retina
ureteral constriction / obstruction causes..
decreased GFR, normal RPF = decreased filtration fraction
FF = GFR/RPF
amino acid w/ 3 titratable protons (3 pKA) (7)
histidine, arginine, lysine, aspartic acid, glutamic acid, cysteine, tyrosine
histidinemia
rare autosomal recessive disorder
deficience of histidase (required for catabolism of histidine)
speech defects, psychomotor & generalized retardation, emotional disturbance
most frequent inborn metabolic error in Japan
how much coronary blood flow occurs in systole
30%
critical factor in determining coronary blood flow, esp in exercise
duration of diastole
single most important risk factor for development of aortic dissection
hypertension!
next: cystic medial degeneration, connective tissue disorder
diabetes mellitus is an important risk factor for developing which 2 major diseases
- atherosclerosis
2. hypertension
most impt factor for development of aortic aneurysm?
atherosclerosis (high cholesterol)
what 4 things increase risk for atherosclerosis (2)
- high cholesterol
- smoking
- HTN
- diabetes mellitus
t. pallidium infects what part of aorta
vasa vasorum in adventitia of ascending thoracic aorta
weakens wall -> predispose to ascending aortic aneursym
dissection = rare w/ syphillis
rx for status epilepticus (4 steps)
1st line: IV lorazepam
2nd. simultaneous phenytoin.
if still seizing:
3rd: phenobarbital
if still seizing
4: intubate / general anesthesia
definition of status epilepticus?
generalized tonic clonic seizure lasting for more than 30min w/o return to consciousness.
mechanism of valproic acid
increase Na+ channel inactivation
block NMDA receptor
affect K+ current
GABA Cl- receptors
rx for myoclonic seizure
valproate -> first line
definition of myoclonic seizure
repetitive seizures, consisting of brief, symmetric muscular contractions w/ loss of body tone causing patient to fall or slump forward.
usu morning and ppt by stress / sleep deprivation
myoclonic seziure vs. tourette tics
tourette: motor tics are nonrhythmic, temporarily suppressible, often preceeded by urge to make stereotyped movement
rx for tourette
typical & atypical antipsychotics, like haloperidol
describe tonic clonic
generalized tonic extension, followed by clonic rhythmic motions
rx: PVC
which DNA pol has 5’-3’ exonuclease activity
DNA pol I (remove primer)
also have 3’-5’ corrective abilities
cyanide toxicity
binds to many iron containing enzymes.
most importantly: cytochrome a-a3 complex (in complex IV)
toxicity: inhibits aerobic metabolism –> rapid death
complex I of ETC is known as? inhibited by?
NADH oxidase
inhibited by: rotenone
complex II of ETC is known as? inhibited by?
succinate dehydrogenase
nothing!
complex III of ETC is known as? inhibited by?
has coenzyme Q
blocked by amtimycin A
complex IV of ETC known as?
inhibited by?
has cytochrome C (between it and complex III)
cyanide + CO
cytochrome a a-a3 complex blocked by cyanide
complex V also known as? inhibited by?
ATP synthase
oligomycin
why make methemeglobin in cyanide toxicity (w/ nitrites)
methemoglobin can’t bind oxygen, but can bind & sequester cyanide (keeps poision away from mitochondria, etc)
cyanide binds ferric iron more than mitochondrial cytochrome enzymes
Dubin-Johnson problem? gross? histology?
defect in hepatic excretion of (conjugated) bilirubin across canalicular membrane.
gross: liver is black
histology: features are normal, though dense pigment of epinephrine metabolites within lysosomes can be seen
histology of liver: dense pigments of epinephrine metabolites in lysosomes?
dubin-johnson
diagnosis of dubin johnson
conjugated hyperbilirubinemia w/ direct bilirubin > 50%
otherwise normal liver function profile must be present
confirmation: unusually high levels of coproporphyrin I
Ras-MAP kinase signalling cascade
growth factor
autophosphorylation of RTK
–> interact w/ SH2 domain protein & SOS protein
leads to Ras activation (G protein) + GTP
–> phosphorylates Raf kinase
all leads to MAP kinase (enters nucleus to influence gene transcription
what kind of protein is Ras
G-protein, activated w/ RTK
PI3K pathway associated w.
PI3K / Akt / mTOR
activation and inactivation of RAS
activated by RTK
inactivated by GAP (GTPase activating protein) 00> hydrolysis
ETEC toxin is like..
cholera toxin, especially heat labile
(heat labile & stabile toxin)
plasmid encoded
LT – like cholera (activates Gs –> adenylate cyclase –> cAMP)
ST – increase cGMP (binds & activates guanylate cyclase on apical membranes of gut mocsal cells)
FIMBRIAE // pilli allow for adhesion
watery diarrhea
invasive gastroenteritis (5)
Salmonella Shigella EIEC Camplyobacter jejuni Entamoeba histolytica
stacked-brick intestinal adhesion
characterestic of enteroaggregative E. coli
EAEC
adhere to jejunal, ileal, and colonic mucosa
do not invade
persistent diarrhea in infants in developing countries
2 risks w/ fibrates
- myositis (esp w/ statin)
- cholesterol stones
use to treat hypertriglyceridemia
side effect w/ ezetimibe?
rare LFT increase, diarrhea
side effect w/ cholestyramine?
taste bad
GI discomfort
decrease absorption of fat soluble vitamins
maybe cholesterol gallstones
statin toxicity
hepatoxicity
myositis (esp w/ niacin & fibrates)
what combination of lipid lowering agents increases myositis
statin + fibrate + niacin
hydroxymethylglutaryl coenzyme A reductase
HMG CoA reductase
convert HMG CoA to cholesterol
statin w/ highest myopathy
simvastatin
jimson weed is similar to
atropine! causes gardener’s mydriasis (anticholinergic crisis)
blind as a bat, mad as a hatter, red as a beet, hot as a hare, dry as a bone, the bowel and bladder loose their tone, and the heart runs alone
anticholinergic crisis
- mydriasis & cylcloplegia
- CNS hallucinations, agitation, delirium
- hyperthermia –> cutaneous vasodilation
- loss of secretions (salvation, lacrimation, sweating)
- decreased GI motility & secretion, urinary retention via detrusor relaxation & constriction of external urethral sphincter
- tachycardia (diminshed vagal tone)
clasp knife spasticity
sign of upper motor neuron lesion:
initial jerking resistance to passive extension followed by sudden release of resistence
due to lack of UMN inhibitory control on spine muscle stretch reflex arc
cortisospinal tracts of spinal cord, medulla, pons & midbrain, internal capsule, precentral gyrus
‘watershed areas’ of bowel (2)
splenic flexure: between SMA and IMA
distal sigmoid colon: between IMA and hypogastric
side effects of colchicine?
binds to tublin & blocks its polymerization
GI ISSUES: many get diarrhea. some, nausea and vomiting (effects on gastric mucosa)
recommended for patients who cannot take NSAIDs (i.e. renal failure, peptic ulcer disease)
which drugs are contraindicated in acute gouty arthritis?
probenecid and allopurinol!
can ppt acute attacks!
describe thiopental mechanism
used for INDUCTION.
highly lipid soluble.
equilibrates w/ brain within 1 minute.
accumulation in brain followed by rapid “redistribution” into skeletal muscles & adipose tissue (within 5-10min)
what is responsible for rapid awakening after thiopental
REDISTRIBUTION (into skeletal and adipose tissue)
NOT metabolism.
carcinoid tumor on histology
eosinophilic cytoplasm, oval-to-round nuclei
minimal to no variation in shape and size of tumor cells.
gland, nests, rows, or sheets may form
EM: dense core granules
ECL cells
APUD system
Amine Precursor Uptake and Decarboxylation
the ECL cells (that become malignantly transformed into carcinoid tumors)
most common location for carcnoid tumor
ileum.
also appendix and rectum.
meningiomas arise from cells of..
arachnoid villi
Arnold-Chiari malformation.
type I vs. type II
congenital issue
underdeveloped posterior fossa
parts of cerebellum & medulla herniate through foramen magnum
type 1:
- low lying cerebellar TONSILS extend below foramen magnum into vertebral canal
- infant: asymptomatic
- adult: headache & ataxia
type 2
- more severe; evident in neonate
- abnormally formed cerebellum & medulla
- TONSIL and VERMIS herniate through
- hydrocephalous (aqueductal stenosis) & lumbosacral myelomeningocele (paralysis)
- medulla compression: dysphagia, dysphonia, stridor, apnea
Dandy walker
agenesis of cerebellar vermis w/ cystic enlargement of 4th ventricle (occupies the enlarged posterior fossa)
associated w/ spina bifida and hydrocephalous
all antidepressants carry risk of..
inducing mania in susceptible patients!
especially TCA and venlafaxine
carbamazepine, lithium and valproate as all
mood stabilizers!
used in acute mania and maintence of bipolar disorder
genetic components of type I and type II diabetes
DM2: strong, but we don’t know gene
DM1: weak, but we know MHC related
twin studies
50% DM1
80% DM2
genes:
DM1: polymorphism in MHC (HLA-DQ and DR)
DM2: polygenic, unknown
HLA-DQ & DR associated with
type 1 diabetes mellitus
type 2: polygenic, unknown
genetics of friedrich’s ataxia
autosomal recessive
chr. 9
frataxin protein – essential for normal mitochondrial fxn
trinucleotide repeats in frataxin gene -> diminished levels pf protein
presentation of friedrich’s ataxia
- ascending / descending spinocerebellar tract degeneration –> ATAXIA
- degeneration of dorsal columns and DRG –> loss of position & vibration sensation
- kyphoscoliosis and foot abnormalities: characteristic skeletal deformity
- hypertrophic cardiomyopathy
- DM in 10%
diffuse medium-sized lymphocytes & high proliferation index (represented by high Ki-67 fraction –> 100%)
burkit lymphoma
EBV related
t(8,14) overexpression of c-MYC
50% of B-cell lymphoma and almost all primary CNS lymphoma in HIV infxn associated w/
Burkitt Lymphoma
4 stages of syphillis
PRIMARY: chancre
1-3wks after contact
resolves in 3-6 wks
SECONDARY: bacteremic stage.
5-10wks following chancre resolution
diffuse macular rash including palms and soles
condylomata lata
LATENT: asymptomatic period.
early latent: 1 year after resolution of secondary symptoms
late latent: more than 1 yr after asymptomatic state
TERTIARY: years after infection.
neurosyphillis: subacute meningoencephalitis, tabes dorsalis, etc
gummas: commonly cutaneous, but also subcut, bones, liver, etc
aortitis: vasovasorum of ascending sorta
painless induration on genitals w/ headaches & memory loss
NOT a chancre bc neuro involvement!
has to be a gumma
describe a chancre
painless ulceration w/ raised, indurated borders.
develops at site of t. pallidum inoculation in 1-3wks. resolves in 3-6 wks.
PRIMARY SYPHILLIS
condylomata lata
large gray wart-like growths that occur in genital / perineal regions
typical manifestation of secondary syphillis
gumma
painless, indurated granulomatous lesions that progress to white-rubbery lesions that may ulcerate.
commonly cutaneous, but also on subcutaneous tissue, bones, liver, other organs.
TERTIARY SYPHILLIS
positive VDRL and pleocytosis in CSF
diagnostic of NEUROSYPHILLIS (part of tertiary syphillis, w/ gummas)
NOT primary.
granuloma inguinale
STD
klebsiella granulomatis
inguinal swelling, ulcers, abscesses, fistulas.
gram stain: cells w/ rod-shaped intracytoplasmic inclusions: Donovan bodies
condyloma accuminata
anogenital wars by HPV (6, 11)
painless ulcer w/ painful lymphadenopathy
lymphogranuloma venerum
C. trachoatis (L1-L3)
chancroid
painful genital ulcer and inguinal adenopathy
haemophilus ducreyi
donovan bodies
granuloma inguinale
klebsiella granulomatis
interferon alpha & beta
innate host defect
secreted by virally infected HOST cells
act on locally unaffected cells “priming them” for viral defense
when infected, viral nucleic acids will activate
HALT PROTEIN SYNTHESIS
- RNAse L: degrade viral & host mRNA
- protein kinase: inhibit viral/host protein synthesis
essentially results in apoptosis (interrupting amplification)
type II interferon (IFN-gamma)
secreted by Th1 and NK cell mainl
promote th1 differentiation, increase expression of class II MHC on APC, and improve intracellular killing of macrophages
type 1 and 2 interferons generally.
increase MHC class I expression
increase NK cell
increase CD8+ cytotoxic
all aim to increase amt of virally infected cells that undergo apoptosis
local pleural thickening w/ calcification (particularly of parietal pleura of posterolateral mid-lung zones & diaphragm)
hallmark of asbestosis
pulmonary manifestation of silicosis
nodular densities & eggshell calcifications of hilar nodes
pulmonary berylliosis
closely resembles sarcoidosis
nodular infiltrates, enlarged lymph nodes, non-caseating granulomas
ITP in children vs. adult
children: acute & self-limited
adult: insidious & chronic course
ITP considered when you DON’T have
signs & symptoms of TTP/HUS, pancytopenia, marrow failure, or splenomegaly (would be sequestration)
what constitutes crescent in RPGN?
FIBRIN & monocytes
also: macrophages, proliferated glomerular parietal cells
eventually oblterate bowman’s space
influenza A infection
can affect 50-75% of school-aged children, often pass on to family.
- abrupt onset fever, headache, myalgia, malaise
- gradually improve over 2-5 days.
staph aureus pneumonia
bronchopneumonia:
most common cause of SECONDARY pneumonia
(bacterial pneumonia on top of influenza)
- recurrent fever, dyspnea, productive cough. see consolidation.
ELDERLY, particularly at risk.
most common agents responsible for secondary bacterial pneumonia
- strep pneumoniae
- staph aureus
- haemophilus influenzae
listeria in neonates
septicemia and purulent meningitis in neonates
klebsiella pneumonia is most commonly responsible for..
nosocomial UTI
nosocomial pneumonia
pneumonia in alcoholics & IV drug
mycobacterium scrofulaceum
cervical lymphadenitis in children
mycobacterium kanasasii
pulmonary TB like symptoms
effect modification
effect of main exposure on an outcome is modified by another variable
a chemo for breast cancer that only helps smokers
not a bias.
MCD is thought to be caused by..
primary defect in immunologic function
(associated w/ respiratory infection, immunization, atopic disorders; helped by steroids)
overproduction of IL-13 –> damage podocytes.
selective albuminuria
