test #30 4.20 Flashcards Preview

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Flashcards in test #30 4.20 Deck (146)
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1

opsoclonus-myoclonus syndrome

non-rhythmic conjugate eye movement w/ myoclonus

2

non-rhythmic conjugate eye movement w/ myoclonus?

opsoclonus-myoclonus

3

most common extracranial childhood tumor

neuroblastoma, usu from adrenal medulla

4

Wilm's tumor vs. neuroblastoma

neuroblastoma: firm, irregular mass. cross midline.

wilm's tumor: smooth and unilateral

5

presentation of neuroblastoma?

child ~2y/o. retroperitoneal mass, HTN.

6

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

7

urine w/ neuroblastoma

increased HVA in urine

8

genetics of neuroblastoma

n-myc amplification

9

prognosis

better if <1 y/o
worse with higher n-myc amplification

10

formation of annular pancreas

ventral pancreatic bud cleaves into two parts, fuse w/ dorsal bud on either side -- can compress duodenal lumen

11

heteroplasmy

mixture of two types of genetic material (i.e. inherit some normal & mutated mitochondria)

12

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

13

characterestics of mitochondrial diseases

1. affect both male & female w/ equal frequency
2. variable degrees of severity: due to heteroplasmy

14

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

15

myoclonic seizures and myopathy associated w/ exercise. skeletal biopsy w/ irregularly shapped muscle fibers (ragged red)

myoclonic epilepsy w/ ragged red fibers.

mitochondrial disease

16

leber hereditary optic neuropathy

mitochondrial disease.

bilateral vision loss

17

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)

18

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)

19

gram negative lactose non-fermenters?

oxidase positive: p. aeruginoas

oxidase negative: shigella, salmonella, proteus

20

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

21

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

22

which enteric bacteria penetrate mucosa & proliferate in mesenteric nodes?

salmonella typhi and yersenia enterocolitica.

23

which bacteria causes pseudoappendicitis?

yersenia enterocolitica. mesenteric lymph node infection, RLQ pain.

24

work of breathing is a balance between..

against elastic resistance of lung and against airflow resistance

25

when is work done against elastic resistance HIGH?

high tidal volumes

26

when is work done against airway resistance HIGH

respiratory frequency

27

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)

28

COPD / asthma (high airway resistance) minimize work of breathing by..

have increased airway resistance, so increase TV, minimize RR

29

pulmonary fibrosis / edema (stiff lungs: high elastic resistance) minmize work of breathing by

rapid shallow breaths (low TV, high RR)

30

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)