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

H. pylori causes..

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

2

genetic polymorphisms assoc. with gastric ca

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

3

H. pylori

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

4

H. pylori: cagA

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

H. pylori: vacA

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

6

H. pylori: LPS

affects production of acid and secretion of pepsinogen

7

H. pylori: Urease

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

8

enterohepatic Helicobacter spp. (EHS)

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

9

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

50%
low SES
PUD, gastric ca

10

H. pylori transmission, etc

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

11

H. pylori risk factors

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

12

H. pylori s/s

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

13

H. pylori can also cause ??? anemia
not assoc. with ??

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

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

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

other H. pylori + assoc.

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

16

H. pylori - assoc.

childhood asthma
MS risk and severity in women

17

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

schizophrenia

18

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

HbA1c
leptin/ghrelin
gastric inflammation-->metabolic syndrome

19

H. pylori is invasively dx by..

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

20

H. pylori is non-invasively dx by..

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

21

ddx H. pylori

steroids, NSAIDS, etOH
(NSAIDS but NOT ASA inc. risk PU bleed if H. pylori present)

22

H. pylori tx

triple threat: PPI, amoxicillin, clarithromycin
confirmed efficacy if dec. H. pylori IgG 1-3 mos post-tx

23

H. pylori ppx

soap and H2O, not etOH hand san

24

acute diarrhea
persistent if ???
chronic if ??

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

25

dysentery

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

26

2 main mechs of diarrhea: intoxication and infection

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

27

other mechs of diarrhea

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

28

low infective dose exs

Shigella, Entamoeba, Giardia (Mt. range)
easily spreads from direct contact

29

high infective does ex

Salmonella (Mt. peak),
everyone gets sick @ same time

30

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

enterocytes
IgA
intraepithelial lymphocytes

31

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


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

prevotellaceae
bacterioidetes
TM7 phylum members

CCL5 secretion

32

host protein ??? is assoc with healthy gut microbiota
if deficient, showed....

NLRP6
dec. levels IL-18 (pro-inflamm. cytokine) and alt. fecal microbiota

33

higher use of abx usage in childhood linked to

allergic eczema, asthma
atopy, Crohn's disease, IBD, DM obesity, autism

34

if vomiting predom. symp

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

35

if large amount mucus in stools

invasive bac diarrhea

36

blood in stool

inflammatory, cytotoxin, invasive (dysentery)

37

watery diarrhea

small bowel

38

fever**

invasive pathogen

39

HUS

STEC, EHEC

40

prodrome

campylobacteriosis

41

dx

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

42

WBCs present in
absent in

invasive bac. inf. and abx rel. diarrhea (C. diff)
viral, parasitic, enterotoxigenic bac (cholera, ETEC), FBIs

43

routine stool Cx orgs

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

44

special stool Cx orgs

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

45

tests for O and P

Direct wet mount
Concentration procedure
Staining

46

parasite immunoassay for

Giardia, Entamoeba, Cryptosporidium

47

modified AF stain (parasites)

Cryptosporidium, Isospora, Cyclospora

48

Trichome stain

Microsporidia

49

PCR for

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

immunoassays

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

51

electron microscopy for

viruses

52

light microscopy/visual

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

53

other assays

Fecal fat (steatorrhea)
Fecal leukocytes
Leukocyte esterase
Fecal lactoferrin

54

blood tests for all pts (watery diarrhea)

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

blood tests for select pts (watery diarrhea)

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

56

fecal tests for all pts (watery diarrhea)

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

57

fecal tests for select pts (watery diarrhea)

α1-antitrypsin clearance ELISA

58

diarrhea general tx

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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