test #30 4.20 Flashcards
opsoclonus-myoclonus syndrome
non-rhythmic conjugate eye movement w/ myoclonus
non-rhythmic conjugate eye movement w/ myoclonus?
opsoclonus-myoclonus
most common extracranial childhood tumor
neuroblastoma, usu from adrenal medulla
Wilm’s tumor vs. neuroblastoma
neuroblastoma: firm, irregular mass. cross midline.
wilm’s tumor: smooth and unilateral
presentation of neuroblastoma?
child ~2y/o. retroperitoneal mass, HTN.
neuroblastoma mets
invasion of epidural space: “dumbbell tumor” spinal cord compression
bone: pancytopenia
liver: hepatomegaly
skin: palpable nodules
periorbital: proptosis, periorbital ecchymoses
paraneoplasic: opsoclonus, myoclonus, truncal ataxia
urine w/ neuroblastoma
increased HVA in urine
genetics of neuroblastoma
n-myc amplification
prognosis
better if <1 y/o
worse with higher n-myc amplification
formation of annular pancreas
ventral pancreatic bud cleaves into two parts, fuse w/ dorsal bud on either side – can compress duodenal lumen
heteroplasmy
mixture of two types of genetic material (i.e. inherit some normal & mutated mitochondria)
mitochondria inheritance
ovum has many mtDNA. few copies in sperm are lost during fertilization.
variability bc during mitosis, mitochondria are RANDOMLY distributed between daughter cells
characterestics of mitochondrial diseases
- affect both male & female w/ equal frequency
2. variable degrees of severity: due to heteroplasmy
three mitochondrial diseases
- leber hereditary optic neuropathy
- myoclonic epilepsy w/ ragged red fibers MERRF
- mitochondrial encephalomyopathy w/ lactic acidosis and stroke-like episodes MELAS
myoclonic seizures and myopathy associated w/ exercise. skeletal biopsy w/ irregularly shapped muscle fibers (ragged red)
myoclonic epilepsy w/ ragged red fibers.
mitochondrial disease
leber hereditary optic neuropathy
mitochondrial disease.
bilateral vision loss
seizure disorder, several stroke-like episodes, increase lactic acidosis.
affected siblings w/ variable degrees of severity
MELAS
mitochondrial encephalopmyopathy w/ lactic acidosis & stroke-like episodes (MELAS)
variable expressivity vs. variable degrees of severity
variable expressivity: differences in severity of autosomal dominant disorders. i.e. Marfan w/ only tall stature, others w/ also root dilation.
NOT a feature of mitochondrial diseases (variable degree of SEVERITY)
gram negative lactose non-fermenters?
oxidase positive: p. aeruginoas
oxidase negative: shigella, salmonella, proteus
differentiate shigella vs. salmonella & proteus in culture
all non-lactose fermenters, oxidase negative.
salmonella & proteus: (1) H2S production (black on TSI agar) (2) mobile
shigella: (1) NO H2S production, not black (2) NOT mobile
essential pathogenic mechanism for shigella
musocal invasion!
via M cells in peyer’s patches
induces apoptosis of host cell and spreads to adjacent ones via protrustions (via host cell-actin polymerization)
less important in pathogenesis: also releases shiga toxin. A subunit inactives 60s ribosome (halts protein synthesis).
does NOT colonize in intestine. only there during active infection.
does NOT cause bacteremia. survives within mucosal layer of intestine
which enteric bacteria penetrate mucosa & proliferate in mesenteric nodes?
salmonella typhi and yersenia enterocolitica.
which bacteria causes pseudoappendicitis?
yersenia enterocolitica. mesenteric lymph node infection, RLQ pain.
work of breathing is a balance between..
against elastic resistance of lung and against airflow resistance
when is work done against elastic resistance HIGH?
high tidal volumes
when is work done against airway resistance HIGH
respiratory frequency
relationship of elastic resistance and air flow on work of breathing.
inverse relationship.
elastic recoil favors low tidal volume (high respiratory rate)
airflow resistance favors high tidal volume (low respiratory rate)
COPD / asthma (high airway resistance) minimize work of breathing by..
have increased airway resistance, so increase TV, minimize RR
pulmonary fibrosis / edema (stiff lungs: high elastic resistance) minmize work of breathing by
rapid shallow breaths (low TV, high RR)
fate of mRNA once it leaves cytoplasm (2)
(1) associate w/ ribosomes = translation
(2) associate w/ P body proteins: distinct foci in eukaryotic cytoplasm, involved w/ mRNA regulation & turnover. role in translation repression and mRNA decay, contains numerous proteins and RNA exonucleases, mRNA decapping enzymes, constituents involved in mRNA quality control and microRNA-induced mRNA silencing. also: mRNA storage (for later use)
polyadenylation sequence
3’ end of RNA
no need for templatte. recognition sequence AAUAAA
5’ cap on mRNA?
7-methylguanosine. unique 5’ to 5’ linkage.
cytoplasmic P bodies
impt role in mRNA translation regulation, degradation and storage
likelihood ratio positive
sensitivty / 1-specificity
test w/ LR+ greater than 10 significantly increases likelihood that patient will have disease for which they are being tested
right brachiocephali is forned by union off..
right subclavian and right internal jugular.
right external jugular drains into right subclavian
brachiocephalic obstruction vs. SVC obstruction?
right side only vs. both sides of face & arms
guyon’s canal
between hook of hamate and pisiform bone. cause ulnar n. (dysesthesia on ulnar side of hand and weakness of intrinsic muscles of hand)
axillary n. innervates
deltoid and teres minor.
affected w/ fracture of surgical neck of humerus
brown pigment stones in gallbladder
(asian) usu arise secondary to infection of biliary tract, which results in release of B-GLUCORONIDASE by injured hepatocytes & bacteria. –> h
ydrolysis of bilirubin glucoronides and increased amount of UNCONJUGATED BILIRUBIN in bile.
recall unconjugated bilirubin = not water soluble!
7-alpha-hydroxlase
converts cholesterol into bile acids.
vassopressin. ADH receptor actions (2)
primary inhibitor of free water excretion
V1: vasoconstriction & prostaglandin release
V2: increase H20 permeability urea
how does vasopressin maximally concentrate urine
(1) express aquaporin receptors in collecting duct.
(2) increases number of passive urea transporters in inner medullary collecting duct (allows substantial number of highly concentrated urea to enter medullary interstitium)
when ADH = high, urea resorption contributes 50% of total osmolarity of medulla
which infections increase risk of brown pigment stones?
bacteria w/ beta-glucoronidase to unconjugate bilirubin in gallbladder OR damage heptocytes to release beta-glucoronidase.
biliary infection w/ (1) e. coli (2) ascaris lumbricoides (3) liver fluke Opisthorchis sinensis
how is copper normally excreted?
into BILE
via hepatocyte copper transporting ATPase (ATP7B gene
wilson’s disease: 2 pathogenesis
autosomal recessive, chr. 13.
(1) defect in Cu2+ excretion into bile (ATPase transporter in hepatocytes)
(2) failure of copper to enter circulation as ceruloplasmin
all leads to copper accumulation in liver, brain, cornea, kidney, and joints
manifestations of wilson’s disease
Copper is Hella BAD
C: decreased ceruloplasmin cirrhosis corneal deposits (kayser-flesicher rings) copper accumulation carcinoma (hepatocellular)
H:
hemolytic anemia
B:
basal ganglia degeneration (parkinsonian symptoms
A:
asterixis
D:
dementia, dyskinesia, dysarthria
kernicterus
billirubin-induced brain damage. often in (1) basal ganglia (2) auditory nucleus (3) oculomotor nucleus
where can urea be reabsorbed (3)
(1) PCT – (reabsorbs about half of filtered load)
(2) thin ascending loop of henle
(3) medullary collecting duct – ADH sensitive
differentiate atypical CD8+ lymphocytes in infectious mononucleosis vs. immature blasts?
atypical CD8+ lymphocytes: abundant blue cytoplasm, basophilic rim <3 RBCs.
immature blasts: less cytoplasm, no bizzarre nuclear changes
EBV increases risk of what 3 things
(1) Hodgkin’s lymphoma
(2) non-hodgkin’s – Burtkitt
(3) nasopharyngeal carcinoma
which macrolide does not inhibit CP450?
azithromycin
which statin is not metabolized by p450 (so less at risk for drug intxn)
pravastatin
hepatitis B viral replication process
DNA hepadnavirus
partially DS
polymerase has DNA polymerase & RNA-reverse transcriptase dependent properties
- partially DS DNA enters nucleus
- viral polymerase finishes –> DS DNA (dna-dep-dna pol)
- host RNA pol makes viral transcripts
- viral polymerase reverse transcribes viral transcripts – DNA (dna-dep rna pol)
viral class for hep A?
RNA picornavirus (naked icosahedral)
viral class for hep E?
RNA hepevirus (naked icosahedral)
viral class for hep C?
RNA flavivirus (enveloped icosahedral)
viral class for hep D?
delta virus
- SS circular
- uncertain capsid
- requires hep B coinfection
viral class for hep B?
DNA hepadnavirus
- enveloped icosahedral
- circular partial DS DNA