RUT NON V I TRNGTc rut S tc nghn h thng d dy rut c th xy ra bt k v tr no, nhng thng xy ra rut non v khu knh tng i hp. Theo thng k, cc tc nghn c hc nh thot v rut, dnh rut, lng rut, xon rut chim 80%, trong khi nguyn nhn khi u v hoi t chim 10 -15% tc nghn rut non. Nhng triu chng lm sng ca tc rut bao gm au bng, chng bng, nn v to bn. Ch nh phu thut thng c t ra vi nhng trng hp tc rut c hc hoc hoi t rut nng. Thot v rut Bt k im yu hoc khim khuyt ca cc l t nhin ca thnh bng u c th cho php cc ti mng bng chui qua gi l ti thot v. Thot v ch yu xy ra thnh bng trc, qua bn, ng i hoc rn hoc so vt m. y l nhng nguyn nhn ca thot v ni tng (thot v ngoi). iu ny phn no ng vi thot v bn, ni c nhng l v h bn rng. Cc quai rut non thng hay b nhng khng phi tt c, c mc treo rut v mt phn i trng cng c th b thot v v b nght. p lc vng c ti c th lm gim dn lu v ca tnh mch. Kt qu l gy ra mu v ph phn ln nhng trng hp thot v rut, dn n c nh, nght hoc lu hn, gy nght cc ng mch v tnh mch dn n hoi t. Hnh 17-23: Tc rut. A: 1 phn ca rut b tc nghn trong thot v bn. Lu cc mng sm mu v xut huyt cho thy c tn thng thiu mu cc b. B: Xon rut do u. Lp ngoi cng ca rut b mt, l ra lp th 2 ca nim mc.. C mt khi u (u thc s) nh ca ti thot v. So snh vi hnh 17-22. Dnh rut Do phu thut, nhim trng hoc nhiu nguyn nhn dn n vim phc mc nh bnh mng trong t cung dn n nguy c dnh cc quai rut, vi thnh bng v v tr phu thut. Hnh thnh cc cu ni x gia cc on rut ni m cc tng khc c th chui qua v b nght, dn n thot v rut. Cc bin chng bo gm tc nghn v nght cc mch mu cng nhiu nh l thot v ngoi. Him gp hn, nhng x dnh rut c th l bm sinh, bi vy thot v rut phi c ch thm ch trong tin s khng c vim phc mc hoc phu thut. Xon rut Mt xon rut hon chnh da trn trc mc treo ca chng lin kt vi nhau v to ra 2 ng v tc nghn mch mu. Bi vy, xon rut c c trng bi s tc nghn v hoi t. Xon rut thng xy ra i trng xch ma, sau 1

n manh trng, rut non, d dy, him gp hn l i trng ngang. Do him xy ra nn lm sng thng b qua. Lng rut Lng rut xy ra khi 1 on ca rut b bp nght bi sng nhu ng, lng vo nhau 1 im. on lng, sng nhu ng y on rut trn chui vo on rut pha di v ko theo c mc treo rut. Nu khng c iu tr, lng rut c th tin trin thnh tc rut, ng mch mc treo v hoi t. Khi xy ra tr s sinh hoc tr nh, chng thng khng c bt thng no, bnh nhn thng khe mnh, mc d mt s trng hp c kt hp vi nhim rotavirus. tr ln v ngi trng thnh mt khi trong lng ng hoc u thng l im ko gy ra lng rut. (Hnh 17 -23B). Tht barrit c tc dng lm gim lng rut tr s sinh v tr nh, nhng can thip phu thut thng cn thit i vi bnh nhn ln tui hn.

BNH THIU MU CC B RUTH thng d dy rut c cung cp mu chnh t ng mch ch bng (celiac), ng mch mc treo trng trn v ng mch mc treo trng di. Khi2

chng tin n gn thnh rut th cc ng mch mc treo trng trn v di s chia nhnh to thnh m ri mch mc treo. S chia nhnh gia cc ng mch, cng nh nhnh tch ra t ng mch ch bng, ng mch sinh dc v tun hon vng xng chu, c th lm cho rut non v i trng b thiu mu cung cp t 1 ng mch. Ngc li, mt tn thng cp tnh ca bt k ng mch chnh no cng c th dn n nhi mu mt vi on rut. Tn thng c th bt u t nim mch, xu hng i su hn di c nim, dn n nhi mu nim mc hoc di nim mc, dn n nhi mu c 3 lp ca thnh rut. Trong khi nhi mu thnh hay nhi mu nim mc thng l th pht dn n gim dch (hypoperfusion) cp hoc mn tnh, nguyn nhn ca nhi mu thng l do tc nch cp. Nhng nguyn nhn tc nhng ng mch cp quan trng nh x va ng mch (hnh thnh mch mc treo), phnh ng mch ch, tnh trng tng ng mu, s dng thuc trnh thai ung, v huyt khi ca cc cardiac vegetation v huyt khi ng mch ch. Gim dch rut c th kt hp vi suy tim, shock, mt nc v cc loi thuc co mch. H thng mch, nh vim a u mch , xut huyt Schonlein Henock, huyt khi, hay vim ht Wegener u c th gy tn thng ng mch rut. Huyt khi mch mc treo c th dn n bnh thiu mu cc b, thng khng ph bin nhng c th l hu qu ca tnh trng tng ng mu di truyn hoc mc phi, u di cn, x gan, vt thng, hoc cc khi u bng gy cn tr s lu thng. Sinh bnh hc p ng ca rut vi s thiu mu din ra qua 2 giai on. Ban u, S gim oxy lm tn thng mch rut. Trong khi mt vi tn thng xy ra trong sut pha ny, nhng t bo biu m lt ca rut p ng li vi s gim oxy. giai on 2, hi phc tn thng, c bt u bng cch khi phc li vic cung cp mu v thi im ny hay xy ra tn thng nht. Mt vi trng hp nghim trng, iu ny c th khi ng cho tn thng nhiu c quan. Trong khi cc c ch ca tn thng hi phc cha c hiu r, chng lin quan n nhng sn phm c bn, thm nhim bch cu a nhn trung tnh, v gii phng nhiu cht ha hc ca phn ng vim nh b th v TNF. Hot ha cc cht ha hc ni bo v cc yu t vn chuyn nh HIF -1, v NF-B, cng gp phn dn n thiu mu cc b rut hi phc tn thng. Cc mc nghim trng ca s gim lu thng mch, khung thi gian m n pht trin, v cc tu b nh hng l nhng yu t quan trng trong bnh thiu mu cc b rut. Hai c im gii phu ca ng mch rut cng gp phn vo s phn b ca tn thng thiu mu cc b. - on rut cui ngun cung cp ca ng mch tng ng rt d b thiu mu cc b. Nhng on gp khc nh on gc lch (l ni tn ht3

-

ca ng mch mc treo trng trn v di), v thp hn, on i trng xigma v trc trng (ni tn ht ca ng mch mc treo trng di, ng mch sinh dc v ng mch chu). Cn phi phn bit bnh thiu mu cc b vi tn thng khu tr do h huyt p v gim oxy mu, v vim i trng gc lch khu tr hoc ct on i trng. Cc mao mch rut chy song song vi cc tuyn, t khe ln b mt, trc khi r ngang trn b mt rut vo cc tnh mch sau mao mch. iu ny cho php oxy mu cung cp cho cc khe tuyn nhng cc t bo biu m b mt rt d b thiu mu cc b. c im gii phu ny bo v cc khe tuyn, l ni c cha cc t bo sinh sn cn thit phc hi lp biu m b mt. Bi vy, teo lp biu m b mt, thm ch hoi t v lot, vi nhng khe tuyn bnh thng hoc tng sn l du hiu hnh thi ca bnh thiu mu cc b.

Hnh thi hc Mc d nhng vng gp khc d b tn thng, nhng nhi mu nim mc v nhi mu thnh c th xy ra bt k v tr no t d dy n hu mn. Nhng tn thng ny c th lin tc nhng thng l tng on cch qung. Nim mc b xut huyt v c th c lot, mu thm hoc tm l hu qu ca xut huyt. Thnh rut thng dy do b ph nim mc, xu hng lan ti lp di nim mc v lp c. mc nng, c xut huyt v hoi t nim mc v di nim mc, nhng xut huyt v vim thanh dch thng khng thy. Mt phn ng k ca rut thng lin quan n transmural infarction bi s tc ng mch cp tnh. Bi nhng nguyn nhn m t trn, on gc lch l on c nguy c cao nht. Cn phn bit r rng gia rut bnh thng v rut thiu mu, rut thiu mu ban u thng c sung huyt mnh, thm mu dn ri n tm . Sau , s tng tit v tch t dch trong m k lm cho thnh rut tr nn ph n, dy v n hi. Xut hin hoi t ng mu ca cc l c trong vng 1 4 ngy v c th dn n thng rut. Vim thanh dch, c th xut hin ni bt vi dch m v lng ng fibrin. Trong trng hp huyt khi tnh mch mc treo, ng mch vn lu thng bnh thng trong mt khong thi gian dn n bin i t t t nh hng n tiu ha. Tuy nhin, s di chuyn ca cc huyt khi c th gy hi th pht n cc c quan khc. Kt qu cui cng cng tng t nh hu qu ca tc ng mch cp tnh bi v s gim lu thng tnh mch dn n cn tr oxy trong mu ng mch i vo cc mao mch.4

c im vi th ca thiu mu cc b rut biu hin bi teo hoc ng vy (sloughing) ca biu m b mt. Ngc li, cc khe tuyn c th tng sn. Xm nhp vim thng khng xut hin lc u thiu mu cc b cp, nhng trong vi gi u ca giai on hi phc thng hay c bch cu a nhn trung tnh. Thiu mu cc b mn tnh khng ph bin, thng kt hp vi cc b x ca m m, v hnh thnh cht hp. giai on cp tnh ca tn thng thiu mu cc b bi nhim vi khun v gii phng c t rut c th hnh thnh gi mc ging nh Clostridium difficile hnh thnh vim i trng gi mc ( cp sau). c im lm sng Bnh thiu mu cc b rut c xu hng xy ra nhng ngi gi c bnh l tim hoc mch. Nhi mu cp tnh in hnh thng xut hin t ngt, au bng d di, v tenderness, i khi km theo bun nn, nn, tiu chy ra mu, hoc i ngoi phn en. Bnh nhn c th tin trin ti shock, try mch trong vi gi ging nh mt mu. Nhu ng rut gim hoc mt, v co tht cc c thnh bng (bng cng nh g). Bi v cc triu chng ging nh cc triu chng ca bng cp tnh khc nh vim rut tha cp, thng lot, vim ti mt cp nn chn on hoi t rut c th b tr hon hoc b qua, vi nhng hu qu tai hi. Khi hng ro nim mc b ph v, vi khun i vo mu v gy nhim trng huyt, t l t vong ln ti hn 50%. S tin trin chung ca rut thiu mu cc b ph thuc vo nguyn nhn v mc nghim trng ca tn thng. - T nhi mu nim mc hoc nhi mu thnh c th khng gy t vong. Tuy nhin iu ny c th dn n nhi mu ln hn nu cc mch mu cung cp khng c khi phc bng cch sa cha nhng tn thng hoc trong bnh mn tnh bng cch pht trin cc tun hon ph. Chn on phn bit gia bnh thiu mu cc b rut v vim i trng c th kh khn bi cc triu chng ca bng khng c hiu bao gm tiu chy c mu v gi tc rut. - Nhi mu mn tnh c th nhm ln nh bnh vim rut vi nhng giai on tiu chy c mu xen ln giai on khi. - Nhim CMV c th gy bnh nhi mu d dy rut do i lc v nhim virus ca cc t bo ni m. Nhim CMV, c th l bin chng ca liu php iu tr c ch min dch, s c tho lun trm trong chng 8. - Vim rut bc x xy ra khi ng rut b chiu x. Ngoi tn thng biu m, bc x cn gy ra tn thng ng k cc mch mu v gy ra nhng bin i tng t nh bnh thiu mu cc b. Ngoi bnh s lm sng, s c mt ca cc nguyn bo si bc x k l trong m m c5

-

th cung cp mt u mi quan trng cho nguyn nhn gy bnh ny. Vim rut bc x cp c biu hin l chn n, au bng nhiu, tiu chy gim hp thu, trong khi vim rut bc x mn tnh thng khng au nhiu hoc c biu hin nh ca vim i trng thng thng. Vim rut hoi t (NEC) l mt ri lon cp tnh ca rut non v rut gi, c th dn n hoi t rut lan rng. y l mt cp cu d dy rut bt buc ca tr s sinh, c bit l tr non hoc nh cn, v thng xy ra vo thi im cho n ung. NEC s c tho lun chi tit hn trong chng 10, nhng c nhc n y v tn thng thiu mu cc b c coi l gp phn vo c ch bnh sinh ca bnh ny.

6

LON SN MCH (Angiodysplasia)Lon sn mch c c trng bi s hnh thnh cc mch mu nim mc v di nim mc. Bnh c th xy ra tt c cc v tr nhng thng manh trng, v i trng phi, thng xut hin sau 6 thng sau sinh. Mc d t l ca lon sn mch l t hn 1% dn s trng thnh, n chim 20% cc triu chng chnh ca xut huyt tiu ha thp; xut huyt tiu ha c th mn tnh, bn cp hoc cp tnh v t. Bnh sinh ca lon sn mch cha r nhng c cho l do yu t c hc v bm sinh. Bnh thng chng bng v co tht lin tc c th gy chn p cc tnh mch di nim mc do p qua lp c v c th dn n gin cc b hoc gp khc hoc nm ln cc mch mu ca lp nim mc v di nim mc. Bi v manh trng c khu knh ln nht ca rut gi, n pht trin thnh rut cng rng nht. iu ny gii thch s pht trin tn thng lon sn mch hay gp nht manh trng v i trng phi. Nhng bin i mch mu lin quan n s lo ha cng c mt s vai tr. Cui cng, mt s d liu lin kt gia lon sn mch vi hp ng mch v ti tha Meckel, gi cho thy c s pht trin ca tn thng ny. Nhng tn thng lon sn mch c ectatic ca cc tnh mch, tnh mch nh v mao mch. Cc mch mu c th ngn cch vi cc quai rut ch bng thnh mch v mt hng ni m di mnh, tn thng nh cng c th gy xut huyt ng k.

7

CHNG KM HP THU V TIU CHY Chng km hp thu xy ra hy ht cc trng hp tiu chy mn tnh, c c trng bi s ri lon hp thu cht bo, cc vitamin tan trong nc v trong du, carbonhydrate, cc cht in gii, mui khong v nc. Chng km hp thu mn tnh c th i km vi st cn, chn n, chng bng, si bng, nhc c. Du hiu nhn bit chng km hp thu l c m trong phn, c trng bi nhng git m trong phn, to th, c bt, phn mu vng hoc mu t st. Ri lon km hp thu mn tnh M hu ht xy ra nhng ngi suy ty, bnh ni tng hoc bnh Crohn. Thi ghp (Intestinal graft-versus-host disease) l mt nguyn nhn quan trng ca chng km hp thu v tiu chy bnh nhn cy ghp ty xng. TABLE 17-6 -- nh hng ca chng km hp thu v bnh tiu chy Tiu ha trong lng ng ti Terminal Digestion + + + + + + + + + + + + + +8

Bnh Bnh ni tng Km hp thu vng nhit i Vim ty mn tnh X - nang Km hp thu acid bile nguyn pht Hi chng ung th biu m Bnh km hp thu t min Thiu Disaccharidase Bnh Whipple Abetalipoproteinemia Vim d dy rut virus Vim d dy rut vi khun Vim d dy rut k sinh

Vn chuyn Vn chuyn qua qua lp biu mch bch m huyt + +

+

+ + +

Bnh trng Bnh vim rut

Tiu ha trong lng ng ti +

Terminal Digestion +

Vn chuyn Vn chuyn qua qua lp biu mch bch m huyt +

+ Ch nh cho nhng TH bt thng ca bnh. Nhng TH khc khng b nh hng.. Chng km hp thu l hu qu ca ri lon t nht 1 trong 4 giai on ca qu trnh hp thu cht dinh dng. (1) Tiu ha trong ng tiu ha, ni m cc protein, carbon hydrate v cht ko c nghin nh c th hp thu c. (2) terminal digestion, lin quan n s phn ct lin kt hydro ca cc phn t carbonhydrate v peptide bi cc enzym disaccharidases and peptidases rim bn chi ca rut non. (3) Vn chuyn qua lp biu m: cht dinh dng, cht lng, in gii c vn chuyn qua lp biu m ca rut non. (4) Vn chuyn qua bch mch ch yu l cc cht bo. nhiu trng hp km hp thu ri lon mt trong nhng giai on k trn chim u th, nhng thng l do ri lon nhiu giai on. Kt qu l, hi chng km hp thu ging nhau nhiu hn chng khc nhau. Cc triu chng thng gp bao gm tiu chy (do ri lon hp thu cht dinh dng, s tng ch tit rut), trung tin, au bng v st cn. Gim hp thu cc vitamin v khong cht c th dn n thiu mu v vim nim mc do thiu pyridoxine, folate, hoc vitamin B12; chy mu do thiu ht vitamin K; chi xng v chut rt do thiu magi, canxi, hoc vitamin D hoc bnh thn kinh ngoi vi do thiu vitamin A, B12. Mt lot cc ri lon ni tit v da cng c th xy ra. Tiu chy c nh ngha l s gia tng khi lng phn, tn s, hoc lng, thng ln hn 200 g/ngy. Trong trng hp nghim trng th tch phn c th vt qu 14 L/ngy v nu khng hi phc nc c th dn n t vong. au bng qun, a mu, mt rn c gi l bnh l. Tiu chy c th c phn loi thnh bn nhm chnh: - Tiu chy th pht c c trng bi phn ng trng v tn ti trong mt thi gian ngn. - Tiu chy thm thu, v d nh do thiu latase, lm tng p lc thm thu nh xy ra do thiu ht lactase, l nguyn nhn lm tng p lc thm thu dn n dch trong lng ng tiu ha khng c ti hp thu. Dch tiu chy hn 50 mOsm thng tp trung nhiu huyt thanh v thng mt nhanh. - Tiu chy hp thu xy ra sau ri lon hp thu dinh dng v thng kt hp vi a m v thuyn gim nhanh.9

-

Tiu chy tit dch thng l do cc bnh vim v c trng bi phn c mu, m, din ra trong mt thi gian ngn.

X ha nang (CYSTIC FIBROSIS) X ha nang s c tho lun chi tit hn chng khc (chng 10). y ch cp n x ha nang v chng km hp thu. Do khng c biu m iu chnh dn xuyn mng x nang (CFTR), kt hp vi nang x ha rut c ri lon bi tit ion clorua. iu ny cn tr bi tit bicarbobate, natri, v nc, cui cng dn n ri lon hydrat ha ng tiu ha. Hnh thnh cc cht kt ta trong ng dn, c th bt u trong t cung, dn n tc nghn ng dn, t tiu mn tnh mc thp ca ty, v cui cng dn n suy ty ngoi tit hn 80% bnh nhn. Kt qu l ri lon giai on hp th cht dinh dng trong lng ng tiu ha, c th c iu tr hiu qu bng b sung thm cc enzym ng ung. Bnh ri lon hp thu m (CELIAC DISEASE) Bnh ri lon hp thu m cn c bit n l bnh km hp thu m hay bnh rut nhy cm gluten. N l mt bnh rut min dch qua trung gian c kch hot bi s tiu ha ca gluten c trong ng cc, nh la m, la mch en, hoc la mch, nhng ngi b bnh di truyn. Bnh ph bin nhng nc ngi da trng gc chu u, vi mt t l mc c tnh l 0,5% n 1%. Sinh bnh hc Bnh ri lon hp thu m l bnh ri lon min dch ng rut duy nht gy bi cht kt ta ca mi trng, c bit n l gltuen. Gluten l protein lu tr chnh trong la m v cc loi ng cc tng t, v mt phn ru ha tan ca gluten, gliadin, cha hu ht cc thnh phn gy bnh. Gluten c tiu ha bi luminal v enzym ca rim bn chi rut thnh cc axit amin v peptide, bao gm mt peptide 33-amino acid -gliadin,l cht c kh nng chng li s tiu ha ca d dy, ty, rut v proteases ca rut non (Hnh 17-25). H thng phn ng min dch vi gliadin c cho l dn n bnh ri lon hp thu m c minh ha di y. Mt s peptide gliadin kch thch t bo biu m tit ra IL 15, gy kch hot v tng sinh cc t bo lympho T CD8 trong biu m lympho, gy hot ha NKG2D, mt yu t dit t nhin. Nhng t bo lympho gy c t bo v ph hy cc t bo rut bc l MIC A b mt, mt HLA lp I ging nh mt protein hot ha trong p ng vi stress. NKG2D l th th ca MIC-A. V vy, khng ging nh cc t bo T CD4, cc t bo T CD8+, NKG2D+ khng nhn ra gliadin. Kt qu tn thng biu m c th gp phn vo qu trnh phn ct cc gliadin khc bi enzym transglutaminase m. Enzym phn ct gliadin sau c th tng tc10

vi HLA-DQ2 hoc HLA DQ8-on trong qu trnh trnh din khng nguyn t bo cho t bo T CD4. Cc t bo T sn xut cytokine gp phn vo tn thng m v nim mc bnh l c trng. Trong khi gn nh tt c mi ngi n ng cc v tip xc vi gluten v gliadin, hu ht khng pht trin bnh ri lon hp thu m. Nh vy, yu t vt ch c xc nh xem l pht trin bnh. Trong s ny, protein HLA hnh nh quan trng, v hu nh tt c nhng ngi b bnh ri lon hp thu m u mang HLA lp II-DQ2 hay allen HLA-DQ8. Tuy nhin, locus HLA chim t hn mt na s gen di truyn ca bnh ri lon hp thu m. Cc yu t di truyn cn li bao gm s a hnh ca cc gen iu tit min dch, nh nhng gen IL-2, IL-21, CCR3, v SH2B3, [46] v cc gen xc nh cc tnh biu m. [47] [48] Ngoi ra cn c mt s hi chng bnh ri lon hp thu m vi cc bnh min dch khc bao gm tiu ng loi 1, vim tuyn gip, v hi chng Sjogren, cng nh mt iu ha, t k, trm cm, mt s hnh thi ca bnh ng kinh, bnh thn IgA, hi chng Down v hi chng Turner. Hnh thi hc Bnh phm sinh thit on hai ca t trng hoc on rut gn, ni c tip xc vi nng cao nht ca ch n gluten, thng chn on bnh km hp thu m. M bnh hc c c trng bi s tng s lng biu m ca lympho T CD 8+ trong biu m(tn thng lympho biu m (intraepithelial lymphocytosis)), qu sn khe tuyn, v teo cc nhung mao (Hnh 17-26). Mt biu m v dim bn chi b mt nim mc cho thy ri lon km hp thu. Thm vo , tc thay th biu m cao, biu hin bng mt nhn chia khe tuyn cao, c th hn ch kh nng ti hp thu ca t bo rut dn n nh hng n qu trnh tiu ha giai on cui (terminal digestion) v vn chuyn qua mng biu m (transepithelial transport). c im khc phn nh y s pht trin bnh ri lon hp thu m l s s lng cc tng bo, t bo mast, bch cu a acid, c bit l pha trn ca m m. Vi sng lc huyt thanh thng xuyn v pht hin sm cc bnh lin quan n khng th, hin nay ngi ta nh gi cao s gia tng s lng t bo lympho biu m, c bit trong sinh thit nhung mao l mt du hiu t quan trng trong bnh ri lon hp thu m.[49 Tuy nhin., tn thng lympho biu m v teo nhung mao khng c hiu cho bnh ri lon hp thu m m c th xut hin trong cc bnh khc, bao gm c vim rut virus. S kt hp ca m hc v huyt thanh hc l c hiu nht chn on bnh ri lon hp thu m c im lm sng ngi trng thnh, bnh celiac xut hin ph bin tui t 30 n 60. Tuy nhin, nhiu trng hp khng c ch trn lm sng trong mt thi gian di bi11

s xut hin khng in hnh. Mt s bnh nhn c th mc bnh celiac im lng, c nh ngha l c huyt thanh dng tnh v teo nhung mao m khng c triu chng, hoc dng bnh tim n, trong c huyt thanh dng tnh nhng khng km theo teo nhung mao. Triu chng bnh celiac ngi ln thng kt hp vi bnh thiu mu, tiu chy mn tnh, y hi, hay mt mi ko di. Mc d khng c s phn bit v gii, bnh ri lon hp thu m c pht hin ph bin hn ph n t 2 n 3 ln, c l do chy mu kinh nguyt hng thng lm tng nhu cu v st v cc vitamin v ni bt nh hng ca s hp th km. Bnh ri lon hp thu m tr em, c nh hng n nam v n nh nhau, c th xut hin vi cc triu chng km hp thu hoc triu chng khng in hnh nh hng n bt k c quan no[50] Trong nhng triu chng kinh in, bnh in hnh thng bt u t tui t 6 n 24 thng, sau khi xut hin gluten trong ch n ung. , v bao gm kh chu, chng bng, chn n, tiu chy mn tnh, khng pht trin mnh, gim cn, hoc nhc c. [50] Tr em c cc triu chng khng c in c xu hng xut hin cc la tui ln hn vi cc triu chng ca au bng, bun nn, nn, y hi, hoc to bn. Nhng kh chu ngoi rut thng c vim khp, au khp, ri lon co git, vim lot p t ming, thiu mu thiu st, chm dy th, v chiu cao thp. Mt c im khc nh nga, rp da, vim da dng herpes, c th xut hin khong 10% bnh nhn, v t l mc vim d dy lympho v vim i trng lympho cng tng ln. Tht khng may, phng php iu tr duy nht hin nay cho cc bnh ri lon hp thu m l mt ch n king khng gluten, nhng, bt chp nhng thch thc ca vic tn trng ch n ung ny, n dn n ci thin triu chng cho hu ht cc bnh nhn. Mt ch n khng gluten cng ng thi lm gim nguy c bin chng lu di bao gm thiu mu, v sinh n, long xng, v ung th. Xt nghim huyt thanh chn on khng xm nhp thng c thc hin trc khi sinh thit. [51] Cc xt nghim nhy cm nht l s hin din ca khng th IgA vn chuyn m hay khng th IgA hoc IgG thy phn gliadin. Khng th khng endomysial rt c hiu nhng nhy thp hn so vi cc khng th khc. Trong trng hp c xt nghim m tnh IgA, thiu ht IgA, l ph bin hn nhng bnh nhn ri lon hp thu m, nn c loi tr. Nu xut hin thiu ht IgA,nn o chun khng th IgG cho vn chuyn m v thy phn gliadin. S khng c mt ca HLA-DQ2 hoc HLA DQ8-rt gi tr cho d on m tnh cao , nhng s hin din ca alen ny khng hu ch trong vic khng nh chn on.12

Bnh nhn c bnh ri lon hp thu m c t l cao hn bnh thng nhng bnh c tnh (Individuals with celiac disease have a higher than normal rate of malignancy). Nhng bnh ung th ph bin nht lin quan n bnh celiac l u lympho T-cell kt hp bnh rut, l mt ung th hch c tnh ca lympho T ni biu m. Ung th biu m tuyn rut non cng l thng xut hin nhng ngi mc bnh ri lon hp thu m. V vy, khi c cc triu chng nh au bng, tiu chy, v gim pht trin cn nng mc d mt c mt ch n ung khng gluten nghim khc, ung th hoc a m kh iu tr, trong tht bi p ng vi ch n khng gluten, phi c xem xt. tuy nhin, iu quan trng cn nh rng vic khng tun th mt ch n king khng gluten l nguyn nhn ph bin nht ca ti pht cc triu chng, v rng hu ht nhng ngi b ri lon hp thu m thc hin tt ch n king v cht v nhng nguyn nhn khng lin quan. Tiu chy m nhit i (TROPICAL SPRUE) Tiu chy m nhit i l mt hi chng km hp thu hu nh ch xy ra nhng ngi sng trong hoc i thm cc vng nhit i, bao gm Puerto Rico, vng Caribbean,Bc Nam M, Ty Phi, n , v ng Nam . Khng gii thch c v sao bnh li khng ph bin Jamaica. Bnh thng c xy ra a phng, mc d dch bnh xy ra. Nhng thay i m hc ca a m nhit i tng t nh bnh ri lon hp thu m, nhng tng s lng nhung mao teo khng nhiu, v a chy nhit i c xu hng lin quan n rut non xa. Sau c th gii thch s xut hin nhn ln (nguyn hng cu khng l) trong cc t bo biu m, gi hnh nh ca trong bnh thiu mu c tnh l do thng xuyn thiu acid folic v vitamin B12. Chng km hp thu thng tr nn r rng trong vi ngy hoc mt vi tun trong tiu chy nhim khun cp tnh. Mc d khng xc nh c vi khun gy bnh, c s liu thu thp v s pht trin qu mc ca vi khun hiu kh ng rut, v thuc khng sinh ph rng thng hiu qu phc hi nhanh chng. Nhng nhim khun khc nhau, gm Cyclospora hoc enterotoxigenic c cp n l nhng yu t gy bnh. Bnh rut t min (AUTOIMMUNE ENTEROPATHY) Bnh rut t min dch l mt ri lon lin kt vi NST X c trng bi tiu chy lin tc nng v bnh t min, thng xy ra tr nh. Mt dng bnh c tnh gia nh r, gi l IPEX, mt t vit tt ca immune dysregulation(mt iu ha min dch), polyendocrinopathy (a ni tit), enteropathy (bnh rut), and X-linkage13

(nm trn NST X), l do t bin gen dng mm trong FOXP3, nm trn nhim sc th X. [52] FOXP3 l mt yu t phin m biu hin trong t bo T CD4 +, [53] v c nhn c IPEX v t bin FOXP3 c khim khuyt chc nng qun T. Cc khuyt tt khc trong chc nng qun t bo T cng c lin kt vi nhng dng bnh rut t min t nghim trng hn. T khng th khng li t bo rut v t bo hnh chn l ph bin, v mt s bnh nhn c th c khng th vi cc t bo thnh hoc t bo khng cn. Cc t bo lympho ni biu m rut non c th tng ln, nhng cha n mc nhiu nh trong bnh ri lon hp thu m, v thng c bch cu trung tnh. Liu php iu tr bao gm cc thuc c ch min dch nh cyclosporin, v trong trng hp him hoi, cy ghp ty xng. [54] Bnh thiu ht lactase (disaccharidases) (LACTASE (DISACCHARIDASE)) Cc disaccharidases, bao gm lactase, nm dim bn chi ca nhung mao ca cc t bo biu m hp thu. Bi v nhng khim khuyt ny l sinh ha nn sinh thit m hc ni chung khng ng k. Thiu lactase l hai loi: Thiu lactase bm sinh, gy ra bi mt t bin trong gen m ha lactase, [55] l mt ri lon gen ln trn NST thng. Bnh ny him gp v biu hin l mt tiu chy d di vi nhiu nc, phn c bt v chng bng khi ung sa. Cc triu chng ny mt khi khng tip xc vi sa v cc sn phm ca sa, bi vy loi b lactose thm thu nhng khng hp thu t cc khoang. Thiu lactase mc phi c gy ra do gim hot ng ca gen lactase, bnh thng ph bin cc th dn chu M, ngi M gc chu Phi, v Trung Quc. Bnh biu hin ngay sau khi sinh, c l phn nh mt thc t l, trc khi nui bng sa ng vt, lactase l khng cn thit, sau khi tr ngng ung sa m. Khi u ca s thiu ht lactose mc phi l i khi kt hp vi nhim trng ng rut do virus hoc vi khun. Cc triu chng bao gm y bng, tiu chy, v y hi, do qu trnh ln men ca ng khng c hp thu bi cc vi khun rut, c kch hot bng ung cc sn phm sa c cha lactose. ABETALIPOPROTEINEMIA Abetalipoproteinemia l mt bnh him gp gen ln nm trn NST thng c trng bi s khng c kh nng tit lipoprotein giu triglyceride. N c gy ra bi mt t bin trong protein vn chuyn triglyceride (MTP) l cht xc tc vn chuyn triglyceride, este cholesterol, v phospholipid. T bo rut thiu MTP khng c kh nng bi xut lipoprotein v acid bo t do. Kt qu l, cc monoglyceride khng th c lp rp vo cc chylomicron v cc triglyceride c tch ly trong cc t bo biu m. Chng km hp thu abetalipoproteinemia l mt tht bi ca vn chuyn qua mng14

biu m. Cc hc lipid nh trong cc t bo biu m ng rut hin r di knh hin vi quang hc v c th c hin r bng cc phng php nhum c bit, chng hn nh du mu -O, c bit l sau mt ba n nhiu cht bo. Abetalipoproteinemia xut hin giai on s sinh v cc hnh nh lm sng ch yu l khng pht trin mnh, tiu chy, v a m. Bnh nhn ng thi khng c cc lipoprotein trong huyt tng bao gm cc apolipoprotein B, mc d nhng gen m ha apolipoprotein B khng b nh hng. Khng hp th axit bo thit yu dn ti s thiu ht cc vitamin tan trong cht bo cng nh cc khuyt tt mng lipid c th c nhn ra bi s hin din ca cc t bo acantho (t bo burr) trong mu ngoi vi.

BNH VIM RUT NHIM KHUN(Infectious Enterocolitis)Vim rut c th xut hienj vi mt lot cc triu chng nh tiu chy, au bng, cp tnh, kh chu quanh hu mn, khng kim sot, v xut huyt (Bng 17-7). Vn ton cu ny c trch nhim vi hn 12.000 ngi cht mi ngy tr em ti cc nc ang pht trin v mt na s ca t vong trc 5 tui trn ton th gii. Nhim trng do vi khun, chng hn nh vi khun Escherichia coli c t rut, nhng cc tc nhn gy bnh ph bin nht thay i theo tui tc, dinh dng, v tnh trng min dch ca vt ch cng nh nh hng mi trng (Bng 17-7). V d, dch bnh ca bnh t l ph bin cc khu vc c v sinh km, hoc l kt qu ca cc bin php y t cng cng khng y , hoc nh l mt hu qu ca thin tai, chin tranh. Bnh tiu chy nhim khun tr em, c th dn n mt nc nghim trng v toan chuyn ha, thng gy ra bi virus. TABLE 17-7 -- c im ca vim rut nhim khunLoi nhim Khu vc khun a l Ngun cha Ly truyn Dch t nh hng GI Triu chng Bin chng

15

T

n , Phn Tm, L t hoc Rut Chu ming, cua, s thnh dch non Phi nc L t, tr i em, khch trng du lch.

Tiu chy nc nng

Mt nc, mt cn bng in gii

Gia cm, sa G, cu, v cc ln, gia thc suc phm khc Nc Phn Shigellosis ang ming, Ngi (L) pht thc n, trin nc Gia cm, Tht, Salmonellos Ton trang tri gia cm, is th gii nui ng trng, vt, b st sa n Phn St thng ,Mexi Ngi ming, hn co, nc Phillipin Nc Campyloba ang cter spp. pht trin Yersinia spp. Enteroxige nic (ETEC) (vi khun c t rut). Enterohem morrhagic(E HEC) (vi khun xut huyt rut) Enteroinva sive (EIEC) (VK xm nhp rut) Bawsv v Trung u Nc ang pht trin

Tiu Vim khp, hi chy chng Guillainnc Barr hoc mu Hi chng Reiter, hi chng i mu

Tr em

Hi trng, a mu i trng tri

Tr em, ngi ln

i Tiu chy trng v nc Nhim c, abcess rut non hoc mu St, a mu Nhim trng mn tnh, ngi lnh mang bnh, bnh no, vim c tim

Tr em, thanh nin, Rut khch du non lch Hi trng, Tht Mt nhm rut Ln ln, sa, nh tha, i nc trng phi Tr nh, Thc thanh nin, Rut Cha r n, Phn khch du non ming lch

au T min, Hi bng, st, chng Reiter tiu chy Tiu chy, mt Mt nc, mt cn nc bng in gii nng a mu Hi chng i mu

Ton Ph bin, L t hoc i B, sa th gii gia sc thnh dch trng Nc ang pht trin B, cc loi thc Cha r Tr nh n khc, nc Cha r

i trng

a mu

Cha r

Enteroagg Ton regative th gii (EAEC) Pseudomem branous colitis (C. difficile) Nc ang pht trin

Tr nh, thanh nin, i Cha r khch du trng lch

Con Khng iu tr c i ngi, sinh cho ch min trng bnh vin php dch, KS xut 16

Tiu chy khng Him thy mu, khng st Tiu Ti pht chy nc, st

Escherichia coli Bnh Whipple Nhim khun Mycobacteri al

hin TP Rural Ton th gii Rut non Rut iu tr c non Cha r Cha r ch min dch Cha r Cha r Him Km hp thu Km hp thu Vim khp, bnh CNS Vim phi v cc nhim trng khc

Bnh t (Choreal) Vi khun t c hnh du phy, l vi khun gram m gy bnh t, mt bnh ph bin vng thung lng sng Hng ca n v Bangladesh c lch s ghi li. T nm 1817, by i dch ln lan rng dc theo cc tuyn ng thng mai sang cc khu vc ln ca chu u, c v chu M, nhng v l do khng r, i dch ny c gii quyt v bnh t rt lui tr v thung lng sng Hng. Dch t cng tn ti vng vnh Mehico. Vi khun t ly truyn ch yu qua nc ung b nhim. Tuy nhin, n cng ng thi c mt trong thc n v gy ra cc trng hp bnh l t lin qua n hi sn Bc M. C mt s bin i theo ma r rt hu ht cc vng kh hu do s pht trin nhanh chng ca vi khun t nhit m; ch sng k sinh nhng loi ng vt c v v sinh vt ph du. C tng i t type huyt thanh gy bnh t, nhng cc loi khc ca vi khun Vibrio cng c kh nng gy bnh. V du, V.parahaemolyticus la nguyn nhn gy bnh ph bin bnh vim d dy rut lin quan n hi sn Bc M. Mc d tiu chy nng, vi khun Vibrio l sinh vt khng xm nhp v vn tn ti trong lng rut. Hnh thnh mt c t rut, c cht t, m ha bi mt th thc khun c lc v sinh ra bi cc vi khun Vibrio, gy ra bnh, nhng cc protein ui, c tham gia vo vic vn ng v kt dnh, l cn thit cho vi khun c tr hiu qu. Hemagglutinin, l mt metalloproteinase quan trng i vi vi khun v rng trong phn. C ch m c t gy ra bnh t l tiu chy cng c hiu r (Hnh 17-27). c t t l bao gm nm tiu n v B v mt n v A. Cc tiu n v B lin kt GM1 thn kinh trn b mt ca t bo biu m rut, v c vn chuyn bi cc khng bo n mng li ni cht, mt qu trnh gi l vn ti ngc. [58] y, cc tiu n v A l gim isomerase disulfua protein, v on mt ca Tiu n v A c m ra v thot c ch. on peptide ny sau c vn chuyn vo bo tng t bo ch bng cch s dng chuyn ng misfolded protein t mng li ni cht n bo tng. Nh vy bc l ra protein thng c x l thng qua cc proteasome, nhng cc tiu n v A gp li ln na trnh ging ha. Cc tiu n v gp li ln na sau tng tc vi cc yu t ribosylation cytosolic ADP (ARFs) ribo ha v kch hot Gs protein G kch thch. iu ny kch hot enzym adenylate cyclase v kt qu l lm tng cAMP trong t bo m iu chnh dn xuyn mng x nang, CFTR, trong vn chuyn17

cc ion clorua vo cc khoang. iu ny dn n nguyn nhn ca s tng bi xut bicarbonate, sodium, v nc, dn n tiu chy nng. V s hp th natri clorua cng b c ch bi cAMP. ng ch , sinh thit nim mc cho thy s thay i ch ti thiu. c im lm sng Hu ht cc c nhn b phi nhim khng triu chng hoc pht trin tiu chy nh. Trong nhng ngi c bnh nng c khi pht tiu chy cp t ngt v nn ma sau mt thi gian bnh t 1 n 5 ngy. Phn tng t nh nc go v i khi c m t l c mi tanh. Tc tiu chy c th t tc 1 lt / gi, dn n mt nc, h huyt p, c bp co tht, thiu niu, sc, mt thc, v cht. Hu ht cc ca t vong xy ra trong vng 24 gi u tin sau khi c biu hin bnh. Mc d t l t vong i vi bnh t nng l khong 50% nu khng diu tr, kp thi bi ph nc c th cu hn 99% bnh nhn. Thng ung b nc l . [59] . Bi trnh hiu bit tng ln v cc protein lin quan n vt ch v vi khun Vibrio, phng php iu tr mi ang c pht trin bao gm cc thuc c ch tit CFTR ngn chn bi xut clorua v phng nga tiu chy [60] t d phng tim phng l. mt mc tiu di hn. [61] Vim rut Campylobacter Campylobacter jejuni l vi khun gy bnh ng rut ph bin nht cc nc ang pht trin [57] v l mt nguyn nhn quan trng ca tiu chy du lch. Hu ht cc bnh nhim trng c lin quan n n tht g nu chn khng ng, nhng dch cng c th c gy ra bi sa cha c tit trng hoc nc b nhim. Bnh sinh Bnh sinh ca nhim khun Campylobacter vn cha c xc nh r rng, nhng bn c tnh c lc ln gp phn gy bnh l: di chuyn, kt dnh, sinh c t, v xm nhp. Roi cho php Campylobacter di ng. iu ny to iu kin kt dnh v chim ch i trng, mt yu t cn thit cho s xm nhp nim mc. c t t bo gy tn thng biu m v c t rut ging nh c t t cng c sinh ra bi mt s chng C. jejuni. Bnh l thng gn lin vi s xm nhp v ch xy ra vi mt nhm nh ca cc chng Campylobacter. St rut xy ra khi vi khun sinh si ny n trong l propria v cc hch bch huyt mc treo rut. Nhim Campylobacter c th dn n vim khp phn ng, ch yu nhng bnh nhn c HLA-B27. cc bin chng khc ngoi ng rut, bao gm ni ban v hi chng Guillain-Barr, mt dng lit mm do t min dch gy ra ca18

bnh vim dy thn kinh ngoi vi, khng lin kt HLA. [62] Sinh hc phn t c cho l lin quan n bnh sinh ca hi chng Guillain-Barr , nh cc khng th trong huyt thanh jejuni C. lipopolysaccharide xuyn phn ng vi h thng hch thn kinh ngoi vi v thn kinh trung ng. Hn na, 15% n 50% cc bnh nhn c hi chng Guillain-Barr c phn dng tnh hoc cc khng th khng Campylobacter lu hnh trong mu. [63] Tht may mn,. Guillain-Barr hi chng pht trin trong 0,1% hoc t hn ca nhng ngi nhim Campylobacter. Hnh thi hc Campylobacter l vi khun c hnh du phy, c roi, Gram m. Chn on ch yu l cy phn, kt qu sinh thit l khng c hiu, v biu l vim i trng cp tnh t gii hn vi cc c im ph bin cho nhiu dng vim i trng nhim khun[64] . Xm nhp nhiu bch cu trung tnh trong nim mc v trong lp biu m l c im ni bt, (Hnh 17 -28A); vim khe tuyn (bch cu trung tnh trong cc khe tuyn) v p-xe khe tuyn ( cc khe tuyn tch ly nhiu bch cu trung tnh) c th c. Quan trng hn, cu trc khe tuyn c bo tn (Hnh 17-28D), mc d iu ny c th kh khn nh gi trong cc trng hp c tn thng nim mc nghim trng. c im lm sng Khong 500 loi C. jejuni c th gy bnh sau mt thi gian bnh ca ln n 8 ngy. Tiu chy nc cp tnh hoc sau mt cc triu chng tin triu ging cm, l triu chng khi pht, v pht trin l 15% bnh nhn. Bnh nhn c th o thi vi khun trong 1 thng tr ln sau khi triu chng lm sng ht. iu tr khng sinh ni chung l khng cn thit.

BNH L SHIGELLA (SHIGELLOSIS) L trc khun Shigella Gram m m ban u c lp trong dch tiu chy Nht Bn nm1897. Bn chng ln hin nay c cng nhn. Shigella khng c v ngoi, khng ui, vi khun k kh ty thuc nhm Enterobacteriaceae v lin quan cht ch n enteroinvasive E. coli. Mc d con ngi mi ch bit n cha, Shigella spp. vn l mt trong nhng nguyn nhn ph bin nht ca tiu chy ra mu. Ngi ta c tnh rng 165.000.000 trng hp xy ra trn ton th gii mi nm. [65] Vi liu gy nhim trng t hn vi trm vi khun v c mt 10 vi khun trong mi gam phn trong bnh cp tnh, Shigella ly truyn cao qua ng phn -ming hoc nc v thc n b nhim.19

Ti Hoa K v Chu u, tr em nh tr, cng nhn nhp c, khch du lch n cc nc ang pht trin, v nhng ngi trong nh dng lo thng nh hng nhiu nht. [66,] [67] Hu ht nhim khun Shigella v t vong xy ra tr em di 5 tui , v nhng nc m vi khun Shigella l ph bin gy cho khong 10% ca tt c cc bnh tiu chy tr em v c n 75% ca t vong do tiu chy. [65,] [68] Bnh sinh Shigella khng vi cc mi trng axt cao ca d dy, c th gy bnh vi liu nhim trng cc thp. Mt khi vo trong rut, vi khun c a ln bi M, hoc microfold, cc t bo biu m, chuyn bt v trnh by cc khng nguyn. Shigella sinh si ny n trong t bo, thot vo propria l, v c thc bo bi cc i thc bo, trong chng s cht theo chng trnh. Cc tn thng ca qu trnh vim tip theo gy tn thng b mt biu m v cho php vi khun Shigella i vo trong thnh rut c tr thnh ca i trng, ch l b mt m thng qua nhim trng c th xy ra trong cc t bo biu m (khc vi cc t bo M). Tt c cc vi khun Shigella spp. plasmid mang c tnh, mt s trong m ha mt h thng bi tit loi III c kh nng trc tip bm protein ca vi khun vo trong bo tng ca t bo ch. L Shigella type huyt thanh 1 cng sn sinh cc c t Shiga STX, m c ch tng hp protein eukaryotic gy tn thng t bo ch v cht. [69] Hnh thi hc Nhim vi khun Shigella ni bt nht i trng tri, nhng cng c th hi trng c l phn nh s phong ph ca cc t bo M trong lp biu m bn trn mng Peyer. Nim mc b xut huyt v lot, c th c gi mc. c im m hc ca cc trng hp sm tng t nh cc trng hp vim i trng cp tnh t gii hn khc, chng hn nh vim i trng Campylobacter, nhng v nhng tropism cho M t bo, lot ap t-xut hin tng t nh trong bnh Crohn c th xy ra. Th tim n c th nhm ln vi bnh vim rut mn tnh, c bit nu c s bin dng ca cu trc khe tuyn. c im lm sng Sau mt thi gian bnh khon 4 ngy, Shigella gy ra bnh t gii hn c trng bi tiu chy, st, au bng khong 6 ngy. Ban u tiu chy nc tin ti giai on l khong 50% bnh nhn, v cc triu chng c th ko di khong 1 thng. Tiu chy bn cp xy ra mt s t ngi trng thnh c c im tiu chy phn vng khi ht tiu chy c th c vim lot nh i trng. [68] Thng xy ra trong hi gian thng ngn hn tr em nhng mc thng nng hn20

nhiu. Chn on xc nh nhim vi khun Shigella l tm thy vi khun trong phn. Cc bin chng ca nhim vi khun Shigella l khng ph bin v bao gm hi chng Reiter, mt b ba vim v khun ca khp, niu o, v kt mc v hay xy ra nhng ngi n ng HLA-B27- trong tui 20 n 40 tui. Hi chng tan huyt-ur huyt, thng lin quan ti enterohemorrhagic E. coli (EHEC), cng c th xy ra sau khi nhim bnh vi L Shigella type huyt thanh 1 tit ra c t Shiga [69] [70] [71]; ch Shigella tit ra c t c lin quan vi hi chng tan huytur huyt (chng 20). iu tr khng sinh rt ngn qu trnh lm sng v lm gim thi gian o thi ht vi khun qua phn, nhng chng ch nh thuc khng tiu chy bi v chng c th ko di cc triu chng v chm tr o thi Shigella. Bnh Salmonella Salmonella, c phn loi trong cc gia nh Enterobacteriaceae ca trc khun gram m, c chia thnh Salmonella typhi, tc nhn gy bnh st thng hn (c tho lun trong phn tip theo) v Salmonella nontyphoid. Nhim Salmonella nontyphoid thng gy ra bi S. enteritidis.; hn 1 triu trng hp xy ra mi nm M, v t l ny thm ch cn ln hn cc nc khc. Nhim trng thng gp nht tr nh v ngi cao tui, vi t l mc cao im vo ma h v ma thu. ng ly truyn thng l thng qua thc phm b nhim bn, tht sng hoc nu cha chn, c bit, gia cm, trng v sa. Bnh sinh Rt t loi Salmonella gy nhim trng, s khng c axit ca d dy, nh cc bnh nhn vim d dy teo hoc nhng ngi iu tr c ch acid, tim chng. Salmonella c gen c lc m ha mt h thng bi tit loi III c kh nng chuyn cc protein ca vi khun vo cc t bo M v t bo rut. Cc protein chuyn kch hot t bo ch lu tr t bo Rho GTPases, t kch hot sp xp li actin v cho php vi khun pht trin trong cc phagosome. Ngoi ra, roi, loi protein li ca vi khun, kch hot TLR5 trong t bo ch v lm tng phn ng vim ti ch. [72] Tng t nh vy, vi khun lipopolysaccharide kch hot TLR4, mc d mt s chng Salmonella sn xut mt yu t c lc ngn cn hot ha TLR4. Salmonella cng tit ra mt loi phn t khin cho biu m gii phng ra hepoxilin eicosanoid A3, qua a bch cu trung tnh vo trong lng rut v vic gy tn thng nim mc. [73] M in dch Th17 nim mc p ng hn ch nhim trng rut gi. Hnh thi hc21

c im vi th ca vim rut Salmonella l khng c hiu v tng t nh vim i trng cp tnh t gii hn ca Campylobacter v Shigella. Xt nghim phn tm vi khun chn on xc nh. c im lm sng Nhim Salmonella trn lm sng khng th phn bit vi nhng nguyn nhn gy bnh ng rut khc, v cc triu chng t phn lng n tiu chy d di nh bnh t v l. St thng ht trong vng 2 ngy, nhng tiu chy c th ko di mt tun v vi khun c o thai ra trong phn vi tun sau khi ht triu chng. Khng nen iu tr khng sinh trong hu ht cc trng hp, bi v n c th ko di tnh trng mang bnh hoc thm ch gy ti pht v khng rt ngn thi gian tiu chy. [74] Hu ht cc nhim khun Salmonella l t khi, nhng cng c th. Nguy c b bnh nng v bin chng tng bnh nhn c khi u c tnh, suy gim min dch, nghin ru, ri lon chc nng tim mch, bnh hng cu hnh lim, v tan huyt thiu mu. St thng hn St thng hn, hay cn gi l st rut, c gy ra bi vi khun Salmonella typhi v Salmonella paratyphi. Bnh nh hng ln n 30 triu ngi trn ton th gii mi nm. a s cc trng hp cc nc dch t l do S. typhi, trong khi nhim trng do S. paratyphi l ph bin hn khch du lch, [75] c l v khch du lch c xu hng s tim chng phng nga S. typhi (khng c vc xin c hiu lc vi S. paratyphi) . Ti cc vng dch t tr em v thanh thiu nin b nh hng nhiu nht, nhng khng c u th tui cc nc pht trin. Nhim trng lin quan cht ch vi du lch n n , Mexico, Philippines, Vit Nam, El Salvador, v Haiti [76]. Ging nh Shigella, con ngi l nhng cha duy nht ca S. typhi v S. paratyphi v ng ly truyn xy ra t ngi sang ngi hoc thng qua thc n hoc nc b nhim. S. typhi hoc S. paratyphi c tr ti mt c th c kt hp vi si mt v tnh trng mang mm bnh. Bnh sinh S. typhi c th sng st trong axit d dy v trong rut non, c a n v xm nhp cc t bo M. Cc vi khun ny sau c che lp bi cc t bo n nhn trong cc m bch huyt bn di. Khng ging nh S. enteritidis., S. typhi sau c th lan rng thng qua cc mch bch huyt v mu. iu ny lm tng sn phn ng ca i thc bo v cc m bch huyt khp c th. Hnh thi hc Tnh trng nhim trng lm cho cc mng Peyer ca on cui hi trng ph i hnh cao nguyn kch thc c th ln n 8 cm. Cc hch mc treo cng ng22

thi to ln. Bch cu trung tnh tch ly trong l propria ngoi, v i thc bo c cha vi khun, hng cu, v kt hp cc mnh v ht nhn vi cc t bo lympho v cc tng bo trong propria lamina. lot nim mc hnh bu dc, pht trin dc theo trc ca hi trng, c th thng. Cc hch bch huyt cng l ni n nu v to ln do tch ly cc i thc bo. Lch to ln v mm, vi nt mu nht ging nhau, du hiu b tc nang, v ni bt hin tng qu sn cc i thc bo. Gan cho thy nh, nhng nh ri rc ca hoi t nhu m trong t bo gan c thay th bng rt nhiu i thc bo, gi l nt thng hn, chng cng c th hnh thnh trong ty xng v cc hch bch huyt. c im lm sng Bnh nhn chn n, au bng, y hi, bun nn, nn v a mu sau mt giai on khng triu chng ngn cch a khun vo v st ging nh cm. [77] Xt nghim mu dng tnh hn 90% bnh nhn trong giai on st, nu iu tr kp thi bng khng sinh s ngn chn bnh tin trin xa hn. [76] nhng bnh nhn khng c iu tr giai on st sau 2 tun st cao ko di v au bng ging vi vim rut tha. Nt dng hoa hng, tn thng ban nh trn da, c th thy trn ngc v bng [77] Triu chng mt i sau vi tun nhng ngi sng st, mc d ti pht c th xy ra. [77] Lan rng ra ton h thng c th gy bin chng ngoi ng rut bao gm bnh no, vim mng no, ng kinh, vim ni tm mc, vim c tim, vim phi, v vim ti mt. Bnh nhn c bnh hng cu hnh lim rt d b vim ty xng Salmonella. Yersinia Ba chng Yersinia gy bnh ngi. Y. enterocolitica v Y. Pseudotuberculosis gy bnh d dy rut v c tho lun y; pestis Y. pestis, tc nhn ca vim phi v bnh dch hch, c tho lun trong Chng 8. Nhim Yersinia d dy rut ph bin chu u hn so vi Bc M v thng lin quan n n tht ln, sa ti, v nc b nhim. Y. enterocolitica l ph bin hn so vi Y pseudotuberculosis, v nhim trng c xu hng xy ra vo ma ng, lin quan n thc phm cha nu chn phc v ti cc bui l. Bnh sinh Yersinia xm nhp vo t bo M nh s dng cc protein kt dnh vi khun, adhesins, bm vo cc t bo ch 1. Mt yu t gy bnh m ha mt h thng hp thu st m lm trung gian vn chuyn v hp thu st; tng t nh h thng vn chuyn st, cng xut hin trong E. coli, Klebsiella, Salmonella, v enterobacteria. Trong nhim Yersinia, st tng cng c lc v kch thch h thng23

ly truyn, iu ny gii thch l do ti sao cc bnh nhn c thiu mu tan huyt hoc st s dn n nhim c v l yu t gy t vong cao. Hnh thi hc Nhim khun Yersinia hay lin quan n hi trng, rut tha, v i trng phi(Hnh 17-28B). Cc vi khun nhn ln ngoi t bo trong m bch huyt, dn n hch vng v mng Peyer tng sn v lm thnh rut dy ln. [79] Cc nim mc pha trn m bch huyt c th xut huyt, v c th xut hin lot dng p t, cng vi xm nhp bch cu trung tnh (xem hnh. 17-28B) v vim ht, d chn on nhm vi bnh Crohn. c im lm sng Ngi b nhim Yersinia thng c biu hin au bng, st v tiu chy. Bun nn, nn v au bng mm l ph bin, xm nhp mng Peyer cng vi s tham gia ca hch vng ging vi vim rut tha cp tnh thanh thiu nin v ngi ln. Vim rut v vim i trng chim u th tr em. Triu chng ngoi rut ca vim hng, au khp, v nt ban hay xy ra. Yersinia c th c pht hin phn trn mi trng thch hoc trong nhng trng hp vi bnh ngoi rut, xt nghim hoc mu [80] Bin chng sau nhim khun, bao gm vim khp v sinh, hi chng Reiter, vim c tim, vim cu thn, vim tuyn gip c ghi nhn. Escherichia coli Escherichia coli l trc khun Gram m sng k sinh ng rut ngi khe mnh, hu ht khng gy bnh, nhng l mt trong nhng nguyn nhn gy bnh cho ngi. Sau ny phn loi da trn hnh thi hc, c ch bnh sinh, v nui cy trong ng nghim. Cc phn nhm theo cc triu chng lm sng ch yu bao gm enterotoxigenic E. coli (ETEC), E. coli enterohemorrhagic (EHEC), E. coli enteroinvasive (EIEC), v E. coli enteroaggregative (EAEC). Enterotoxigenic E. Coli Vi khun ETEC l nguyn nhn chnh ca bnh tiu chy du lch v ly lan qua thc n v nc b nhim. Nhim trng thng gp khu vc km pht trin, v tr em di 2 tui c bit d mc. ETEC sn xut c t khng chu nhit (LT) v c t chu nhit (ST), v c hai lm tng bi tit clorua v nc trong khi c ch s hp thu rut. Cc c t LT cng tng t nh c t bnh t v kch hot adenylate cyclase, dn n tng cAMP trong t bo. iu ny kch thch bi tit clorua v ng thic ch hp thu. c t ST, c protein guanylin tng t ca ng vt c v, gn vi guanylate cyclase v tng cGMP trong t bo24

vi dn n kt qu v vn chuyn tng t nh nhng sn phm ca LT. Cng ging nh bnh t, c im m bnh hc ca nhim trng ETEC l hn ch. Lm sng triu chng bao gm s ch tit, tiu chy khng vim, mt nc v sc trong cc trng hp nng. Enterohemorrhagic E. Coli EHEC gm c 2 type huyt thanh gm E. coli O157: H7 v khng O157: H7. Nhng v dch ln ca E. coli O157: H7 cc pht pht trin c lin quan n vic n tht b nu cha chn, i khi t cc c s thc n nhanh. Sa b nhim v rau qu cng l tc nhn ca nhim trng. C hai tup O157: H7 v khng O157: H7 sn xut c t ging l, do vy hnh thi hc (xem hnh 17-28C.) v cc triu chng lm sng tng t nh l do Shigella. Typ O157: H7 ca chng EHEC c kh nng gy ra nhng v dch ln hn khng tup O157: H7, a mu, v hi chng tn huyt - ur huyt. Enteroinvasive E. Coli Vi khun EIEC l vi khun tng t nh vi khun Shigella v c ly truyn qua thc n, nc, hoc tip xc gia ngi vi ngi. Trong khi EIEC khng sn xut ra cht c, chng xm ln cc t bo biu m v gy ra cc triu chng hng c hiu ca vim i trng cp tnh t gii hn (xem hnh 17-28D.). Nhim EIEC thng gp tr nh cc nc ang pht trin v i khi gy ra nhng v dch cc nc ang pht trin. Enteroaggregative E. Coli Vi khun EAEC c xc nh trn c s s gn kt vi cc t bo biu m. Nhng vi khun ny c xc nhn l mt nguyn nhn gy ra tiu chy tr em v ngi ln cc nc pht trin cng nh cc nc ang pht trin. y cng c th l mt nguyn nhn gy ra tiu chy du lch. [81] EAEC kt dnh vo cc t bo rut bng cc fibriae adhesin v c h tr bi dispersin, mt protein b mt ca vi khun trung ha in tch m b mt ca lipopolysaccharide. Trong khi nhng vi khun ny sn xut ra c t c lin quan n vi khun Shigella v c t ETEC ST, tn thng m hc l ti thiu v cc tn thng ny ch c th nhn thy bng knh hin vi in t [82] Vi khun EAEC gy ra tiu chy khng c mu v c th ko di nhng bnh nhn c hi chng suy gim min dch mc phi (AIDS). Bnh vim i trng gi mc (PSEUDOMEMBRANOUS COLITIS) Vim i trng mng gi, thng gy ra bi Clostridium difficile, cn c gi l vim i trng lin quan n khng sinh hoc tiu chy lin quan n khng25

sinh. Nhng thut ng sau p dng cho tiu chy ang tin trin trong hoc sau mt qu trnh iu tr khng sinh v c th l do C. difficile cng nh Salmonella, C. perfringens typ A, hoc Staphylococcus aureus. Hai vi khun sau sn xut ra c t rut v l tc nhn ph bin ca ng c thc phm. Bnh sinh Ri lon h vi khun ng rut do thuc khng sinh to iu kin cho C. Difficile pht trin. Mc d hu ht cc khng sinh u c th gy ra, cephalosporin th h th ba lin quan nhiu nht. Suy gim min dch cng l mt yu t thun li ca bnh vim i trng C. difficile. c t c sinh ra bi C. difficile gy ra ribosylation ca GTPases nh, chng hn nh Rho, v dn n ri lon trong b khung t bo biu m, mt hng ro bo v, sn xut cytokine, v cht t bo. [83] Cc c ch theo cc qu trnh ny dn n cc c trng v hnh thi hc ca vim i trng gi mc vn khng hon ton c hiu r. Hnh thi hc Bnh vim a trng lin quan n C. difficile l mt dng ca vim i trng gi mc, hnh thnh s kt dnh ca cc t bo vim v dch ca nim mc i trng b tn thng. Trong khi vim ai trng gi mc khng c hiu v c th xy ra bnh nhn thiu mu cc b hoc nhim khun hoi t, m bnh hc ca vim i trng lin quan n C. difficile ni bt. B mt biu m b bong trt v lp m m bn di b xm nhp bi rt nhiu bch cu a nhn trung tnh v lng ng fibrin trong cc nh. Cc khe tuyn b tn thng b gin ra bi cha nhiu cht dch, hnh thnh nn tn thng gi nh dng ni la. Nhng khi dch tit ny hnh thnh nn gi mc c im lm sng Yu t nguy c ca vim i trng C. difficile-lin quan bao gm tui cao, bnh vin, v iu tr khng sinh. Vi khun ny c bit ph bin ti cc bnh vin, c n 30% bnh nhn ngi ln nhp vin phi nhim C. difficile (mt t l ln hn mi ln dn s ni chung), nhng hu ht bnh nhn phi nhim khng mc bnh. Nhng bnh nhn vim i trng C. difficile- c biu hin st, tng bch cu, au bng, au bng, khng d ng, tiu chy nc, v mt nc. Phn c th c bch cu v a mu vi th, a mu i th him xy ra. Chn on vim i trng lin quan C. difficile thng pht hin bng cch pht hin cc c t C. difficile, hn l xt nghim phn, v c h tr bi cc m bnh hc c trng. Metronidazole hoc vancomycin thng l liu php hiu qu, nhng khng khng sinh v tha vitamin cng nh C. difficile cng nh bnh ti pht ang ngy cng ph bin. [84] Bnh Whipple (WHIPPLE DISEASE)26

Whipple bnh l mt bnh mn tnh a ph tng him c m t u tin nh l lon dng lipid ng rut vo nm 1907 bi George Hoyt Whipple. A. 27 nm sau, nh gii phu bnh ny c nhn gii thng Nobel cho cng trnh ca ng v bnh thiu mu c tnh. ng cng cc ng nghip nhng khng c h hng l Allen Oldfather Whipple, cc bc s phu thut l nhng ngi i tin phong trong phu thut ct b khi t ty. Bnh sinh Trng hp bo co u tin ca Whipple c m t trn mt bnh nhn km hp thu, bnh ca hch bch huyt, v vim khp xut khng r ngun gc. Khm nghim t thi chng minh s hin din ca cc i thc bo bt v mt s lng ln cc mnh a argyron trong cc hch bch huyt, cung cp bng chng cho thy y l mt bnh nhim khun [85] Cc trc khun roi Gram dng, c t tn Tropheryma whippelii, c cho l gy ra bnh Whipple bnh c pht hin bng phng php PCR vo nm 1992 v cui cng c nui cy trong nm 2000. [86] Cc triu chng lm sng xy ra do cc i thc bo n vi khun tch ly trong m m ca rut non v cc hch mc treo rut, gy cn tr tun hon bch huyt. Nh vy, tiu chy km hp thu ca Whipple bnh l do vn chuyn bch huyt km. Hnh thi hc Cc du hiu hnh thi ca bnh Whipple l s tch ly cc i thc bo bt trong m m ca rut non (Hnh 17-30A). Cc i thc bo dng tnh vi phn ng periodic acid-Schiff (PAS), cc ht khng diastase tiu biu cho cc lysosome ang tiu ha mt phn vi khun (Hnh 17-30B). Trc khun hnh que cng c th c pht hin bng knh hin vi in t (Hnh 17-30c). Xm nhp ca cc i thc bo bt cng xut hin trong bnh lao ng rut (Hnh 17-30D), v c hai vi khun gy bnh u dng tnh vi PAS. Tuy nhin, phng php nhum axit nhanh c th c dng phn bit chng cc v cc mycobacteria s dng tnh(Hnh 17-30E) trong khi T. whippelii khng. S pht trin cc nhung mao gy ra bi thm nhim cc i thc bo dy c lm cho b mt nim mc tr nn th, x x. Gin cc nang bch huyt v lng ng lipid nim mc lm cho nim mc c nhng mng mu trng n mu vng c th nhn thy c qua ni soi thng thng. Trong bnh Whipple, i thc bo cha y vi khun c th tch ly trong cc hch bch huyt mc treo rut, mng hot dch khp b nh hng, van tim, no, v cc c quan khc. Cc biu hin lm sng ca bnh Whipple thng l mt b ba ca tiu chy, st cn, v km hp thu. Cc triu chng ngoi rut c th tn ti trong nhiu27

thng hoc nhiu nm trc khi c chng km hp thu, bao gm vim khp, au khp, st, bnh u tuyn hch, v thn kinh, tim, hoc bnh phi. Nhim mycobacteria c tho lun chi tit trong Chng 8. Vim d dy rut virus (VIRAL GASTROENTERITIS) Cc triu chng nhim virus ngi gy ra bi mt vi nhm khc nhau ca virus. Ph bin nht s c tho lun y. Norovirus Virus ny trc y c bit n nh virus ging Norwalk v l mt nguyn nhn thng gp ca vim d dy rut v khun. [87] y l loi virus kp nh vi mt b gen RNA si n thuc gia nh Caliciviridae. Norovirus gy ra khong mt na s v dch vim d dy rut trn ton th gii v l mt nguyn nhn thng gp ca vim d dy rut ri rc cc nc pht trin. Dch a phng thng lin quan n thc phm b nhim hoc nc, nhng ng ly truyn t ngi sang ngi l cn nguyn ca hu ht nhng v dch l t. Nhim trng ly lan d dng trong trng hc, bnh vin, nh dng lo v gn y nht l trn nhng tu du lch. Sau mt thi gian bnh ngn, bnh nhn b nhim s c biu hin bun nn, nn, tiu chy, v au bng. c im hnh thi hc trn sinh thit l khng c hiu. Khi pht hin cc bt thng r rut non bao gm cc nhung mao ngn, hc trong biu m, mt cc vi nhung mao ca dim bn chi, qu sn khe tuyn v xm nhp lympho trong m m (Hnh 17-31A). Bnh ny l bnh t gii hn. Rotavirus Virus c v ngoi mt b gen l on RNA si i gy nhim 140.000.000 ngi v gy ra ci cht ca 1triu ngi mi nm, khin cho rotavirus l nguyn nhn ph bin nht ca bnh tiu chy nng v t vong tr em trn ton th gii. Tr em t 6 n 24 thng tui d b mc nht. Min dch trong 6 thng u i c th l do s hin din ca cc khng th khng rotavirus trong sa m, trong khi min dch sau 2 tui l min dch hnh thnh sau cc nhim trng u tin [88] Dch hay xy ra ti cc bnh vin v cc trung tm gi tr v ly lan d dng, c tnh s ly nhim ch ti thiu 10 ht virus. Rotavirus ly nhim v ph hy c chn lc cc t bo rut trng thnh rut non, v cc nhung c phc hi l do cc t bo non sinh ra. iu ny dn n mt chc nng hp thu v bi tit nc v in gii, d ln trong mt tiu chy thm thu do khng hp th y cc cht dinh dng. Ging nh norovirus, rotavirus c thi gian bnh ngn sau, ch vi ngy xut hin nn v tiu chy. c vaccin v vic s dng chng c th s28

thay i dch t hc ca nhim rotavirus. Adenovirus Nguyn nhn th hai ph bin nht ca bnh tiu chy tr em (sau khi rotavirus), adenovirus cng nh hng n bnh nhn suy gim min dch. [89] Sinh thit rut non c th thy s thoi ha ca biu m nhng thng c teo nhung mao khng c hiu v b p bng tng sn cc khe tuyn.Nhn ca virus l khng ph bin. Bnh thng biu hin sau mt thi gian bnh khong1 tun vi cc triu chng khng c hiu bao gm tiu chy, nn v au bng. St v gim cn cng c th c. Cc triu chng thng mt i trong 10 ngy.

29