Flashcards in test #30 4.20 Deck (146)
non-rhythmic conjugate eye movement w/ myoclonus
non-rhythmic conjugate eye movement w/ 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.
invasion of epidural space: "dumbbell tumor" spinal cord compression
skin: palpable nodules
periorbital: proptosis, periorbital ecchymoses
paraneoplasic: opsoclonus, myoclonus, truncal ataxia
urine w/ neuroblastoma
increased HVA in urine
genetics of neuroblastoma
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
mixture of two types of genetic material (i.e. inherit some normal & mutated mitochondria)
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
1. affect both male & female w/ equal frequency
2. variable degrees of severity: due to heteroplasmy
three mitochondrial diseases
1. leber hereditary optic neuropathy
2. myoclonic epilepsy w/ ragged red fibers MERRF
3. 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.
leber hereditary optic neuropathy
bilateral vision loss
seizure disorder, several stroke-like episodes, increase lactic acidosis.
affected siblings w/ variable degrees of severity
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
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
relationship of elastic resistance and air flow on work of breathing.
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)