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Flashcards in H. pylori and diarrhea intro Deck (58)
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1
Q

H. pylori causes..

A
gastric carcinoma (80%)
esophageal SqCC
non-NSAID type B gastric/duod ulcers
PUD
gastritis stuff/polyps
a fib
2
Q

genetic polymorphisms assoc. with gastric ca

A

IL-1B, IL-1B receptor, TNF-a, IL-10

3
Q

H. pylori

A

G- curved rod, microaerophilic, oxidase positive, acid-tolerant, facultative IC organism
>50% cagA and vacA positive

4
Q

H. pylori: cagA

A

cytotoxin-assoc. gene A
most imp. virulence factor, inc. risk of gastric cancer with chronic gastritis
effector protein: inj. directly into host cell (type 4 secretion)–>invades stem-like cells–>translocates into gastric epi cells–>rearrrang. host cytoskel and alters cell signaling, perturbs cell cycle control
induce expression of a DNA-editing enzyme–>mutations in p53

5
Q

H. pylori: vacA

A

cytotoxin, req. for ulcer formation, dysfunc. autophagy: hinders fusion of autophago with lysosome–>accel. H. pylori replication

6
Q

H. pylori: LPS

A

affects production of acid and secretion of pepsinogen

7
Q

H. pylori: Urease

A

essential for virulence and survival, cleaves urea–>ammonia and CO2, raises pH of v. acidic stomach, more livable

8
Q

enterohepatic Helicobacter spp. (EHS)

A

extragastric: hepatobiliary tract
H. hepaticus, H. bilis, H rapipini, H. ganmani, H. pullorum
chr. pancreatitis, pancr. ca, and IBD: + for EHS

9
Q

about ?? of world’s pop infected with H. pylori
affects who
15-20% will develop

A

50%
low SES
PUD, gastric ca

10
Q

H. pylori transmission, etc

A
fecal-oral, gastric-oral, oral-oral
intrafam spread, humans main reservoir
inc. with age, 
not gender related
no seasonality
11
Q

H. pylori risk factors

A
crowding
being a gastroent.
fam contact
certain MHC-II genotype 
*HLA-DR* haplotype via cross-reaction, molecular mimicry
12
Q

H. pylori s/s

A
gradual onset (wks-mos) burning (epigastric) ulcer when empty
sometimes: N/V/anorexia, bloody or tar-like stools, vomiting bood, hemoptysis
13
Q

H. pylori can also cause ??? anemia

not assoc. with ??

A

sideropenic (refractory) iron-deficiency anemia and anemia of pregnancy
vomiting up or shitting out blood (absence of active GI bleed)
dec. response to iron therapy (eradicate pylori to inc. response)

14
Q

relationship btw ??? and H. pylori (hint: blood)
mechanism?
tx?

A

idiopathic thrombocytopenic purpura (ITP)
molecular mimicry btw antiplatelet Abs and CagA
eradicate w/ abx to show platelet response
also similar link to: lichen planes and rosacea

15
Q

other H. pylori + assoc.

A
vascular disease (w. CagA+)
idiopathic parkinsonism
coronary instability (CagA+)
dopa dysfunc, dec. PUFAs, inflamm, homocysteine alterations-->dev. of shizo
16
Q

H. pylori - assoc.

A

childhood asthma

MS risk and severity in women

17
Q

H. pylori assoc. dopa dysfunc, dec. PUFAs, inflamm, homocysteine alterations may play a role in dev. of

A

schizophrenia

18
Q

H. pylori dir/indirectly raises ??? levels (think obesity) as it regulates ???
also cause ???

A

HbA1c
leptin/ghrelin
gastric inflammation–>metabolic syndrome

19
Q

H. pylori is invasively dx by..

A

endoscopic biopsy: histo studies, brush biopsy
Cx (80% sn)
CLO test for urease

20
Q

H. pylori is non-invasively dx by..

A

breath test w. 13C urea, meas. 13CO2 (esp kiddos

21
Q

ddx H. pylori

A

steroids, NSAIDS, etOH

NSAIDS but NOT ASA inc. risk PU bleed if H. pylori present

22
Q

H. pylori tx

A

triple threat: PPI, amoxicillin, clarithromycin

confirmed efficacy if dec. H. pylori IgG 1-3 mos post-tx

23
Q

H. pylori ppx

A

soap and H2O, not etOH hand san

24
Q

acute diarrhea
persistent if ???
chronic if ??

A

3+ stools/day of dec. form 2 wks
>1 mo
*most is self-limiting

25
Q

dysentery

A

intestinal inflammation (esp. colon) + pain, tenesmus, stools w. mucus and blood

26
Q

2 main mechs of diarrhea: intoxication and infection

A

intox: staph; pre-formed in food
infec: cholera, ETEC, Shigella, etc

27
Q

other mechs of diarrhea

A
hormone-sec. tumor
nutri. malabsorption
food allergy
DM, hemochromatosis, SLE, SCD, hemophilia
stress
28
Q

low infective dose exs

A

Shigella, Entamoeba, Giardia (Mt. range)

easily spreads from direct contact

29
Q

high infective does ex

A

Salmonella (Mt. peak),

everyone gets sick @ same time

30
Q

immunity in the intestinal epithelium: ??? can present Ag, express sec. component, and transport ??
?? act as cytotoxic cells

A

enterocytes
IgA
intraepithelial lymphocytes

31
Q

bacterial flora that cause inflammation and are associated with periodontal dis. and IBD

the alteration triggers ?? causing inflamm. and inc. IBC

A

prevotellaceae
bacterioidetes
TM7 phylum members

CCL5 secretion

32
Q

host protein ??? is assoc with healthy gut microbiota

if deficient, showed….

A

NLRP6

dec. levels IL-18 (pro-inflamm. cytokine) and alt. fecal microbiota

33
Q

higher use of abx usage in childhood linked to

A

allergic eczema, asthma

atopy, Crohn’s disease, IBD, DM obesity, autism

34
Q

if vomiting predom. symp

A

food-borne, viral (less common symp. than diarrhea)

35
Q

if large amount mucus in stools

A

invasive bac diarrhea

36
Q

blood in stool

A

inflammatory, cytotoxin, invasive (dysentery)

37
Q

watery diarrhea

A

small bowel

38
Q

fever**

A

invasive pathogen

39
Q

HUS

A

STEC, EHEC

40
Q

prodrome

A

campylobacteriosis

41
Q

dx

A

microscopic exam
#/types of WBCs-methylene blue
leuko-test for leukocyte esterase
tests for fecal lactoferrin

42
Q

WBCs present in

absent in

A

invasive bac. inf. and abx rel. diarrhea (C. diff)

viral, parasitic, enterotoxigenic bac (cholera, ETEC), FBIs

43
Q

routine stool Cx orgs

A

Salmonella, Shigella, Campylobacter, and enterohemorrhagic (sorbitol-negative) E. coli, Aeromonas/Plesiomonas

44
Q

special stool Cx orgs

A

Yersinia enterocolitica Vibrio cholerae Non-cholera vibrios Clostridium difficile Others (food borne)

45
Q

tests for O and P

A

Direct wet mount
Concentration procedure
Staining

46
Q

parasite immunoassay for

A

Giardia, Entamoeba, Cryptosporidium

47
Q

modified AF stain (parasites)

A

Cryptosporidium, Isospora, Cyclospora

48
Q

Trichome stain

A

Microsporidia

49
Q

PCR for

A

bac: Campylobacter, Clostridium difficile toxin A/B, Escherichia coli O157, enterotoxigenic E coli (ETEC) LT/ST, Salmonella, Shigella, and Shiga-like toxin producing E coli (STEC) stx 1/stx 2
viruses: (norovirus and rotavirus A)
parasites: (Cryptosporidium and Giardia).

50
Q

immunoassays

A

C. difficile toxins A and B Shiga (Vero) toxin Rotavirus

51
Q

electron microscopy for

A

viruses

52
Q

light microscopy/visual

A
acterial motility (vibrio, Campylobacter)
Flecks of mucus (rice water stools- V. cholerae) Occult blood or frank dysentery
53
Q

other assays

A

Fecal fat (steatorrhea)
Fecal leukocytes
Leukocyte esterase
Fecal lactoferrin

54
Q

blood tests for all pts (watery diarrhea)

A

Complete blood cell count with differential
Electrolyte levels
Albumin level
Prothrombin time
Folate concentration
Iron studies
Vitamin B12 concentration Thyroid-stimulating hormone level
Erythrocyte sedimentation rate or C-reactive protein level

55
Q

blood tests for select pts (watery diarrhea)

A

Celiac serologies Thyroid-stimulating hormone level
Amebic serology D-xylose (after 25-g load, urinary level also acceptable)
HIV (ELISA)

56
Q

fecal tests for all pts (watery diarrhea)

A

Culture and sensitivity Ova and parasites (3 specimens)
Giardia antigen ELISA Clostridium difficile toxin assay
Fecal occult blood
Fecal fat (qualitative)
Fecal leukocytes

57
Q

fecal tests for select pts (watery diarrhea)

A

α1-antitrypsin clearance ELISA

58
Q

diarrhea general tx

A

fluid/e-lytes
BRAT for kiddos

restr. use abx (Rifaximin for trav. diarrhea ppx)

probiotics (Lactobacillus rhamnus and L. reuteri)-kiddos and IBS adults

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