test #23 4.12 Flashcards Preview

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Flashcards in test #23 4.12 Deck (88):
1

congenital lactase deficiency

rare autosomal recessive. caused by gene near (but separate from) lactase gene

2

bacterial fermentation of undigested lactose leads to..

fermentation, producting short-chain fatty acids and excess hydrogen ---> acidic stool

3

stool osmotic gap

most stool osmolality --> Na and K. gap = colonic fermentation products.

when mostly electrolytes, osmotic gap low (< 50mOsm/kg).
when poorly absorbable substances present, osmotic gap large > 100mOsm/Kg

4

D-xylose absorption test

absorption of D-xylose diminished in numerous malabsorptive conditions. like celiac sprue. not associated w/ lactose intolerance.

D-xylose, a monosaccharide that does not require digestion for absorption; just needs an intact mucosa.

can distinguish between musocal & nonmucosal causes of malabsorption (i.e. celiac vs. pancreatic insufficiency)

5

lactose deficiency individuals have... (3)

increased stool osmotic gap, increased breath hydrogen content, and decreased stool pH upon lactose challenge.

6

pancreatic location in abdomen

head, neck, body retroperitoneal. tail is intraperitoneal.

head overlies L2. body overlies L1 and L2. posteriorly contacts aorta, superior mesenteric vessels, left kidney. tail courses w/ splenorenal ligament alongside splenic vessels

7

anthax most commonly acquired via

exposure to infected animals / animal products OR use as a biological weapon

not person-to-person

8

forms of anthrax (3)

(1) cutaneous, most common
(2) pulmonary, 5% (but nearly 100% mortality)
(3) gastrointestinal, rare

9

ERB-B2 gene aka.. expressed in..

Her-2/Neu.

overexpressed in breast cancer, adenocarcinoma of ovary, stomach, lung, salivary glands.

codes for transmembrane glycoprotein w/ tyrosine kinase activity.

normally expressed in small amounts.

10

n-myc associated with..

neuroblastoma and small cell carinoma of lung

11

sis proto-oncogene codes for.. overexpressed in?

platelet-derived growth factor. overexpressed in astrocytoma and osteosarcomas

12

rx for cryptococcus meningitis

amphotericin B + flucytosine. long-term maintenance w/ fluconazole

13

schizoid vs. avoidant

avoidant strongly desires acceptance. schizoid do not care.

avoidant: inadequacy, timidity, fear of rejection

14

diffuse esophageal spasms

periodic, non-peristaltic contractions of esophagus.

usu painful. "cork-screw" on barium esophogram.

intermittent dysphagia w/ occasional chest pain. can mimic UNSTABLE ANGINA. rule out w/ complete cardiac work-up

15

symptom of GERD

heartburn: burning, central pain frequently after meal or night. DES = crampy, not burn

16

digital rectal exam of BPH vs. prostate cancer.

BPH: rubbery.
cancer: nodular & firm

17

changes resulting from BPH upstream

bladder wall hypertrophies: increase contractile force.

ureter, pelvis, calyces dilate (hydronephrosis)

renal parenchyma atrophic and scarred due to reflux of urine & damage.

18

3rd pharyngeal puch

inferior parathyroid glands & thymus

19

pharyngeal pouches

1, 2, 3, 4
ears, tonsils, bottom to, top
ears, palatine tonsils, inferior parathyroid & thymus, superior parathyroid & ultimobranchial body

20

thyroid diverticulum from

floor of the foregut

21

laryngeal cartilage originates from

4th and 6th pharyngeal arches

22

mutation in polycythemia vera

clonal myeloproliferative disease of pluripotent hematopoietic stem cells. 95% have V617F mutation involving JAK2 gene.

replaces a valine w/ phenylalanine at 617 --> makes hematopoetic cells more sensitive to growth factors (like EPO and TPO)

23

EPO producing tumors

hepatocellular carcinoma, renal cell carcinoma

24

shigellosis can be caused by..

shigella dysenteriae, flexneri, boydii, sonnei.

80% are sonnei in US

25

shigella entry into body

M cells in peyer's patches in mucosa of ileum

26

substrates in urea cycle

ordinarily, careless crappers are also frivolous at urination

in mito: ornithine + carbamoyl, citrulline,

in cytosol: aspartate, arginosuccinate, fumarate, arginine, urea (and regenerate ornithine)

27

N acetylglutamate is needed for

activity of carbamoyl synthetase II. to convert NH3 + CO2 + ATP ---> carbamoyl phosphate

28

myasthenia gravis particularly affects

waxing & waning progressive weakness of voluntary muscles, particularly those innervated by motor nuclei of brainstem (ocular, masticatory, facial, deglutitional (swallowing), and lingual movement)

29

what happens when anti-nAChR binds in myasthenia gravis?

receptor internalization & complement fixation (degradation).

less opening of nicotinic cation channels --> reduced end plate potential

30

classic presentation of multiple sclerosis

SIIN
- scanning speech, internuclear opthalmoplegia, intention tremor, incontinence, nystagmus

31

eye findings w/ multiple sclerosis

optic neuritis: sudden loss of vision resulting in Marcus Gunn pupil. internuclear opthalmoplegia.

32

selective muscarinic antagonist for abdominal cramping, nausea, sweating, diarrhea

scopolamine and hyoscyamine

33

which symptoms may persist in wernicke-Korsakoff?

memory loss (korsakoff syndrome). can persist after fixing oculomotor dysfunction & ataxia in Wernicke-Korsakoff

34

which brain regions are damaged in korsakoff syndrome?

anterior & dorsomedial thalamic nuclei -- leads to memory loss and confabulation. when unsure of fact, fill in memory gap with fabricated story they believe to be true.

35

presentation of wernicke-korsakoff (3)

thiamine deficiency leads to impaired neuronal energy utilization --> cell death & atrophy

1. oculomotor dysfxn: damage to CN III CN VI, and vestibular nuclei. rapidly reversible w/ thiamine
2. ataxia: cerebellar cortex & vestibular nuclei damage. takes longer to resolve, can be permanent
3. mental status change: disorientation, apathy, decreased attn respond well. memory & learning abnormalities often persist --> korsakoff syndrome (mamillary body)

36

rxn catalyzed by HMG CoA reductase

HMG CoA --> mevalonate. rate limiting step in cholesterol synthesis

37

how do bile acid resins affect bile acid secretion (i.e. cholestyramine)

increase bile acid production and secretion 10-fold

38

describe amount of bile acid in body & cycles

4 grams of bile acid in body. circulated 6-8 x 1 day

39

how does niacin work

1. inhibits adipocyte lipolysis 2. inhibits VLDL production by liver

40

how do fibrates work?

1. activate LPL to decrease triglycerides 2. increase production of HDL my liver

41

tremulousness after a few days in an alcoholic?

due to alcohol withdrawal, rx: long lasting benzodiazepines [diazepam or chlordiazepoxide]

lorazepam use in patients w/ advanced liver disease (short-acting)

long term alcohol: down-regulate GABA receptors

42

describe alcohol withdrawal

begins 8-12 hours after last drink.

insomnia, tremulousness, mild anxiety, headache, autonomic hyperactivity (variable BP, diaphoresis, tachycardia)

if untreated: delirium tremens (generalized tonic-clonic seizures and hallucinations) may develop around day 3

rx: long lasting benzo (diazepam chlordiazepoxide)

life threatening!

43

baclofen

agonist of GABAb. treat spastic conditions

44

5 different categories of xanthomas

1. eruptive xanthoma: yellow papules abruptly appear when plasma triglycerides and lipids arise
2. tuberous / tendinous: latter on achilles tendons and extensor tendons of finger.
3. plane xanthomas (linear lesions in skin folds strongly associated w/ primary biliary cirrhosis
4. xathelasma: soft eyelid or periorbital plaques with no associated lipid abnormalities in 50% of affected individuals

45

histology of xanthoma

benign macrophages packed w/ finely vacuolated, "foamy" cytoplasm. contains high levels of cholesterol, phospholipids, and triglycerides. lipid-laden macrophage frequently associated w/ inflammatory cells and fibrotic stroma.

46

p. aeruginosa toxins

EXOTOXIN A (inactivates EF-2 via ADP ribosylation). major virulence factor

also collagenase, elastase, fibrinolysin, phospholipase C, DNAse

47

how does v. cholera increase cAMP?

Gs ADP ribosylation ACTIVATES adenylate cyclase.

48

how does b. pertussis increase cAMP?

Gi ADP ribosylation DISINHIBITS adenylate cyclase

49

acute serositis in SLE

fibrinous exudation. usu pleuritis and pericarditis.

50

common presenting features of SLE. demographic

usu women 20-40. malar facial rash, photosensitivty w/ exacerbation of cutaneous disease after sun exposure, arthralgia. constitutional symptoms: fever, malaise, weight loss. renal involvement. serositis (pleuritis, pericarditis)

51

3 layers of GI mucosa

epithelium, lamina propria, muscularis mucosa

52

erosion vs. ulcer

erosion is just mucosa (can't penetrate through muscularis mucosae). ulcer penetrates & extend into submucosal & muscularis propria

53

causes of acute erosive gastropathy? symptoms?

NSAID, surgical stress, head trauma (cushing ulcer) , burns (curling ulcer) smoking, alcohol.

range of symptoms: asymptomatic, life threatening upper GI bleed (melena). epigastric discomfort, pain, nausea, vomitting.

symptoms withdrawl when remove offending agent

54

1st most common cause of gastric ulcer? 2nd?

1st: h. pylori
2nd: NSAID (inhibit prostaglandin synthesis, reduced mucin and bicarb secretion & gastric perfusion, increase gastric acid secretion)

55

two roles of leptin on appetite and metabolism

released by adipocytes

1. decrease neuropeptide Y (NPY) production in arcuate nucleus of hypothalamus ---> DECREASED APPETITE

2. increase POMC production --> more a-MSH ---> INHIBIT FOOD INTAKE

56

incidence

number of new cases per year / total population AT RISK

(not people w/ disease already or dead

57

rx for warfarin toxicity (bleeding)

fresh frozen plasma first, then vitamin K (will take time to make new clotting factors)

58

rx for tPA overdose

aminocapropic acid and tranexamic acid (inhibit plasminogen activation)

59

antiphagocytic capsule is primary virulence factor for which 3 species?

step pneumo, h. flu, and neisseria

60

major virulence factor for staph aureus

protein A (bind to Fc portion of IgG)

61

filgrastim

granulocyte colony stimulating factor analogue

62

neurofibromatosis I

chromosome 17: von Recklinghausen's disease

63

neurofibromas are composed of..

schwann cells

64

troponins are situated. what does each subunit do?

small globular proteins situated alongside tropomyosin molecules. troponin composed of 3 subunits. troponin T, I and C.

troponin T: binds other troponins to tropomyosin
troponin I: binds complex to actin
troponin C: binds to calcium

65

what can cause drug-induced parkinsonism

D2 blockers (1st generation antipsychotics > 2nd) in the nigrostriatal pathway.

rx: antimuscarinics (trihyxyphenidyl or benztropine)

not dopa --> ppt psychosis

66

Kerley B lines

short horizontal lines situated perpendicular to the pleural surface that represent edema in interlobular septa

67

chest x-ray in acute left ventricular failure w/ pulmonary edema

cardiomegaly (heart > 1 hemithorax in size, pleural effusion (blunting of costophrenic angle), Kerley B lines, increased vascular shadowing (alveolar edema) bilaterally)

68

myelobasts go on to be

one of the granulocytes

69

chromosome 16 inversion associated with

M4Eo subtype of AML

70

bacterial vaginosis (gardernella) vs. trichomonas infection

trichomonas: vaginitis. yellow-green, foamy, foul smelling discharge. see motile trophozites with flagellae on wet mount microscopy

gardernella: non-painful. gray discharge w/ "fishy" odor. addition of KOH makes odor prominent: "positive whiff test". presence of clue cells (epithelial cells w/ bacteria on them) is characteristic

71

fanconi anemia

autosomal recessive, hypersensitivity to DNA cross-linking agents

72

bloom syndrome

autosomal recessive, hypersensitivity to UV damage and chemo

73

bulimia

recurrent binge eating w/ compensatory behaviors to prevent weight gain (either restrictive or purging). at least 2x/wk for 3 months.

74

body dysmorphic disorder

intense preoccupation w/ an imagined bodily defect that leads to functional impairment (i.e. overweight despite normal BMI)

75

binge-purge anorexia nervosa vs. bulimia

anorexia nervosa --> abnormally low body weight ( <17.5) and amenorrhea

76

factitious disorder vs. malingering

factitious disorder: intentional production or feigning of physical / psychological symptoms for purpose of assuming sick role.

malingering: voluntary fabrication of symptoms for purpose of obtaining an external reward.

77

what cells do renal clear cell carcinoma originate from

proximal convoluted cells

78

hemosiderin

iron-storage complex. see in bleeds or in hemochromatosis

79

how does gamma-carboxylation permit coagulation factors to functoin

creates calcium-binding sites on 2,7, 9, 10; allows for intxn w/ phospholipid

80

which 4 populations are susceptible to vitamin K deficiency?

(1) malabsorption syndromes

(2) broad-spectrum antibiotics

(3) neonates (limited hepatic reserve, unestabilished intestinal flora, limited bioavailability of vit K in breast milk

(4) those affected w/ generalized liver disease (healthy liver's recycle vitamin K such that little is required in diet)`

81

five symptoms of zinc deficiency

(1) delayed wound healing (2) alopecia (3) diarrhea (4) acrodermatitis eneteropathica (5) dysgeusia and anosmia

82

b2 (riboflavin) deficiency

FAD and FMN, redox rxn (succinate dehydrogenase)

cheilosis and corneal vascularization

83

B6 (pyridoxine) deficiency

(1) transamination (2) decarboxylation (3) glycogen phosphorylase

needed to synthesis: cystathionine, heme, niacin, histamine, neurotransmitters: 5-HT, epinephrine, norepinephrine, dopamine, GABA.

peripheral neuropathy, sideroblastic anemia (due to impaired hemoglobin synthesis and iron excess)

84

Zolpidem, Zalepon, esZopiclone

nonbenzo hypnotics, acts at BZI site on GABAa, reversed by flumenazil

85

short-acting benzo (3)

triazolam, oxazepam, midazolam

86

medium duration benzo (2)

temazepam and estazolam

87

cavernous hemangioma

birth or later. soft blue compressible mass (few cm). light microscopy --> large dilated vascular spaces.

88

conditions associated w/ avascular necrosis of femoral head

sickle cell, SLE, steroids & alcohol.

MRI most sensitive to diagnose