Ucwaningo lwamawele lwakamuva lubonise izindlela ezintsha zokuvuselela inhliziyo eyonakele
Ukwehluleka kwenhliziyo kuthinta okungenani abantu abayizigidi ezingama-26 emhlabeni wonke futhi kuyimbangela yokufa kwabantu abaningi. Ngenxa yokwanda kwabantu asebekhulile, ukunakekela i inhliziyo kuba yisidingo esiholela ekwenyukeni kwezindleko. Kube nentuthuko enkulu ekwelashweni kwesifo inhliziyo futhi ziningi izinyathelo zokuvimbela ezithathwayo, nokho, ukufa nokugula kusephezulu kakhulu. Zimbalwa kakhulu izindlela zokwelashwa ezitholakalayo futhi ikakhulukazi zisekelwe ekufakelweni kwenhliziyo ezigulini ezisesigabeni sokugcina futhi ezithuthukela ekuhlulekeni kwenhliziyo okuphelele.
Imizimba yethu inawo amandla angavamile okuziphilisa, isibonelo isibindi singakwazi ukuvuselelwa lapho sonakele, isikhumba sethu naso isikhathi esiningi kanye nenso eyodwa ingakwazi ukusebenza izikhathi ezimbili. Ngeshwa, lokhu akulona iqiniso eziningi zezitho zethu ezibalulekile - kuhlanganise nenhliziyo. Uma inhliziyo yomuntu ilimele - okubangelwa yisifo noma ukulimala - umonakalo uhlala unomphela. Isibonelo, ngemva kokuhlaselwa yinhliziyo, izigidi noma izigidigidi zamangqamuzana emisipha yenhliziyo zingalahleka unomphela. Lokhu kulahlekelwa kwenza inhliziyo ibe buthakathaka kancane kancane futhi kuholele ezimeni ezimbi njengokuhluleka kwenhliziyo, noma izibazi enhliziyweni ezingase zibulale. Ukwehluleka kwenhliziyo kuvame ukuvela lapho i-cardiomyocyte (uhlobo lwamaseli) luntula. Ngokungafani nama-newt nama-salamanders, abantu abadala abakwazi ukuphinda bakhule ngokuzenzekelayo izitho ezilimele njengenhliziyo. Ku-embryo yomuntu noma lapho umntwana ekhula esibelethweni, inhliziyo amaseli ayahlukana aphindaphindeke okusiza inhliziyo ukuthi ikhule futhi ithuthuke izinyanga eziyisishiyagalolunye. Kodwa izilwane ezincelisayo kuhlanganise nabantu abanalo ikhono lokuvuselela inhliziyo njengoba zilahlekelwa leli khono kamuva futhi ngokuphelele ngemva kwesonto lonke zizelwe. Amaseli emisipha yenhliziyo alahlekelwa amandla awo okuhlukana nokuphindaphindeka futhi ngenxa yalokho awakwazi ukuvuselela. Lokhu kuyiqiniso nakwamanye amangqamuzana omuntu - ubuchopho, umgogodla njll. Njengoba la maseli amadala engakwazi ukuhlukana, umzimba womuntu awukwazi ukuthatha indawo yamaseli alimele noma alahlekile futhi lokhu kuholela ezifweni. Nakuba lesi futhi kuyisizathu esenza kungabi khona isimila senhliziyo - izimila zibangelwa ukukhula okungalawuleki kwamaseli. Nokho, uma kungenzeka ukuthi la mangqamuzana aphinde ahlukane, lokhu kungase kubangele “ukuvuselelwa” kwenani lezicubu futhi kusize ukulungisa isitho.
Okuwukuphela kwenketho ubani anayo lapho ehlushwa ubuthaka noma inhliziyo eyonakele noma isifo senhliziyo ukuthola ukufakelwa inhliziyo. Lokhu kunezici eziningi ngokuvamile ezithinta ukufakelwa ukuthi kube ngokoqobo ezigulini eziningi. Okokuqala, inhliziyo enikelwa “ngomnikeli” kufanele ibe yinhliziyo enempilo ngaphambi kokuthi lowo onikeleyo adlule emhlabeni, okusho ukuthi inhliziyo idinga ukuvunwa kubantu abasha abashonile ngenxa yokugula noma ukulimala futhi lezi zimo azizange zibathinte. inhliziyo nganoma iyiphi indlela. Ozoba yisiguli kufanele afane nenhliziyo yomnikeli ukuze athole ukufakelwa. Lokhu kusho ukulinda isikhathi eside. Njengenye indlela engenzeka, amandla okukwazi ukudala umsipha omusha enhliziyweni ngokuhlukana kwamangqamuzana anganikeza ithemba ezigidini ezinenhliziyo ezilimele. Izinqubo eziningi zizanyiwe futhi zahlolwa umphakathi wesayensi, nokho, imiphumela kuze kube manje ayisebenzi.
Esifundweni esisha esishicilelwe ku- Iseli, abacwaningi eNyuvesi yaseCalifornia, eSan Francisco, eU.SA ngokokuqala ngqá baye basungula indlela ephumelelayo nezinzile ezifanekisweni zezilwane ukuze benze amangqamuzana enhliziyo yabantu abadala (i-cardiomyocyte) ahlukanise futhi ngaleyo ndlela akwazi ukulungisa ingxenye eyonakele yenhliziyo.1. Ababhali bahlonze izakhi zofuzo ezine ezibandakanyeka ekuhlukaniseni amaseli (okungamaseli aziphindaphinda ngokwawo). Lapho lezi zakhi zofuzo zihlanganiswa nezakhi zofuzo ezibangela ukuthi i-cardiomyocyte evuthiwe iphinde ingene emjikelezweni weseli, babona ukuthi amangqamuzana ayahlukana futhi azalana. Ngakho, lapho umsebenzi walezi zakhi zofuzo ezine ezibalulekile uthuthukiswa, i inhliziyo izicubu zabonisa ukuvuselelwa. Ngemuva kokuhluleka kwenhliziyo esigulini, le nhlanganisela ithuthukisa ukusebenza kwenhliziyo. Ama-cardiomyocyte abonise ukuhlukaniswa kwamaphesenti angu-15-20 ocwaningweni lwamanje (uma kuqhathaniswa nephesenti elingu-1 ezifundweni zangaphambili) okuqinisa ukwethembeka nokusebenza kahle kwalolu cwaningo. Lolu cwaningo lunganwetshwa ngokobuchwepheshe ezinye izitho ngoba lezi zakhi zofuzo ezine ziyisici esivamile. Lona umsebenzi ofanele kakhulu ngoba noma yiluphi ucwaningo ku inhliziyo okokuqala kuyinkimbinkimbi kakhulu futhi okwesibili ukulethwa kwezakhi zofuzo kufanele kwenziwe ngokucophelela ukuze kungabangela noma yiziphi izimila emzimbeni. Lo msebenzi ungaphenduka ube yindlela enamandla kakhulu yokuvuselela inhliziyo nezinye izitho.
Olunye ucwaningo olwenziwe yi-Stem Cell Institute, eNyuvesi yaseCambridge, e-UK, selusungule indlela entsha yokulungisa inhliziyo izicubu ngendlela yokuthi onikelayo angadingeki nhlobo2. Basebenzise ama-stem cells ukuze bakhulise ama-patches aphilayo “emisipha yenhliziyo” elabhorethri engamasentimitha-skwele angu-2.5 kuphela kodwa abukeka njengethuluzi elinamandla lokwelapha iziguli ezinesifo senhliziyo. Lawa ma-patches anethuba elikhanyayo lokutholwa ngokwemvelo esigulini inhliziyo okungukuthi "izicubu ezisebenza ngokugcwele" ezishaya futhi zifinyele njengomsipha wenhliziyo ojwayelekile. Indlela yokuqala yokujova ama-stem cell emzimbeni ukuze alungise inhliziyo ayiphumelelanga ngoba ama-stem cells awazange ahlale ku-stem cell. inhliziyo umsipha kodwa esikhundleni salokho walahleka egazini. Isiqephu samanje siyizicubu zenhliziyo “eziphilayo” kanye “ezishayayo” ezingaxhunywa esithweni (kulokhu inhliziyo) futhi ngaleyo ndlela noma yimuphi umonakalo ungalungiswa. Ama-patches anjalo angakhuliswa lapho kunesidingo sesiguli. Lokhu kuzodlula isidingo sokulinda umnikezeli ofanayo. Lezi ziqephu zingatshalwa kusetshenziswa i- inhliziyo amangqamuzana esiguli siqu asusa izingozi ezihilelekile ekufakeni isitho somzimba. Ukuhlanganisa isiqephu sibe yi-a inhliziyo eyonakele kuyinqubo ehlaselayo futhi idinga ama-impulses alungile kagesi ukwenza inhliziyo i-beat ehlanganiswe kahle ne-patch. Kodwa izingozi ezihilelekile kulolu hlobo lwenqubo zingcono kunokufakelwa kwenhliziyo okuphelele okuhlasela kakhulu. Ithimba lilungiselela ukuhlolwa kwezilwane kanye nokuhlolwa komtholampilo phakathi neminyaka emi-5 ngaphambi kokuthi lokhu kusetshenziswe kabanzi inhliziyo iziguli.
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{Ungafunda iphepha lokuqala locwaningo ngokuchofoza isixhumanisi se-DOI esinikezwe ngezansi ohlwini lwemithombo ekhonjiwe}
Umthombo (s)
1. U-Mohamed et al. 2018,. Ukulawulwa Komjikelezo Weseli Ukuze Ukhuthaze Ukukhula Kwe-Cardiomyocyte Yabantu Abadala kanye Nokuvuselelwa Kwenhliziyo. Iseli. https://doi.org/10.1016/j.cell.2018.02.014
2. University of Cambridge 2018. Ukuhlanganisa inhliziyo ephukile. http://www.cam.ac.uk/research/features/patching-up-a-broken-heart. [Kufinyelelwe ngoMeyi 1 2018]
