Uphononongo lwamawele akutsha nje lubonise iindlela ezintsha zokuhlaziya intliziyo eyonakeleyo
Ukusilela kwentliziyo kuchaphazela ubuncinane abantu abazizigidi ezingama-26 kwihlabathi liphela kwaye kukhokelela ekufeni kwabantu abaninzi. Ngenxa yokwanda kwabantu abalupheleyo, ukunyamekela intliziyo kuya kuba yimfuneko ekhokelela ekwandeni kweendleko. Kukho inkqubela phambili ebalulekileyo kunyango lwentliziyo kwaye kuthathwa amanyathelo amaninzi okuthintela, nangona kunjalo, ukufa kunye nokugula kusephezulu kakhulu. Zimbalwa iindlela zonyango ezikhoyo kwaye uninzi lwazo luxhomekeke ekufakweni kwentliziyo kwizigulana ezikwinqanaba lokugqibela kwaye ziqhubela phambili ekusileleni kwentliziyo ngokupheleleyo.
Imizimba yethu inamandla angaqhelekanga okuziphilisa, umzekelo, isibindi sinokuvuselelwa xa sonakele, ulusu lwethu lukwahlala ixesha elide kwaye intso enye ingathatha umsebenzi wabantu ababini. Ngelishwa, oku akunjalo kumalungu ethu amaninzi - kuquka intliziyo. Xa intliziyo yomntu yonakele - ngenxa yesifo okanye ukwenzakala - umonakalo uhlala uhleli. Umzekelo, emva kokuhlaselwa yintliziyo, izigidi okanye izigidi zeeseli zemisipha yentliziyo zinokulahleka ngonaphakade. Oku kulahlekelwa kuyenza buthathaka intliziyo kancinci kancinci kwaye kukhokelela kwiimeko ezinzulu ezifana nokusilela kwentliziyo, okanye amanxeba entliziyweni anokubulala. Ukusilela kwentliziyo kudla ngokubangelwa kukuba ii-cardiomyocytes (uhlobo lweeseli) ziswele. Ngokungafaniyo nee-newts kunye nee-salamanders, abantu abadala abanakukwazi ukuphinda bakhule amalungu awonakeleyo njengentliziyo. Kwi-embryo yomntu okanye xa umntwana ekhula esibelekweni, iiseli zentliziyo ziyahlukana kwaye ziyanda nto leyo enceda intliziyo ukuba ikhule kwaye iphuhle kangangeenyanga ezilithoba. Kodwa izilwanyana ezincancisayo kuquka nabantu azinawo amandla okuphinda zivelise intliziyo njengoko zilahlekelwa leli khono emva koko kwaye ngokupheleleyo emva kweveki yokuzalwa. Iiseli zemisipha yentliziyo ziyalahlekelwa ngamandla azo okwahlukana nokwanda kwaye ngenxa yoko azinakuphinda zivelise. Oku kuyinyaniso nakwezinye iiseli zabantu – ingqondo, umqolo njl.njl. Ekubeni ezi seli zabantu abadala zingenako ukwahlukana, umzimba womntu awunakuthatha indawo yeeseli ezonakeleyo okanye ezilahlekileyo kwaye oku kukhokelela kwizifo. Nangona le ikwayisizathu sokuba kungabikho thumba lentliziyo – iithumba zibangelwa kukukhula okungalawulekiyo kweeseli. Nangona kunjalo, ukuba kunokwenzeka ukuba ezi seli zahlukane kwakhona, oku kunokukhokelela “ekuvuselelweni kwakhona” kwezicubu ezininzi kwaye kuncede ekulungiseni ilungu.
Eyona ndlela inye umntu anokuba nayo xa ehlushwa yintliziyo ebuthathaka okanye eyonakeleyo okanye isifo sentliziyo kukufakelwa intliziyo. Oku kunemiba emininzi echaphazela ukufakelwa kwentliziyo ekubeni yinto eyenzekayo kwizigulane ezininzi. Okokuqala, intliziyo enikelwa "ngumnikeli" kufuneka ibe yintliziyo ephilileyo ngaphambi kokuba umnikeli asweleke, oko kuthetha ukuba intliziyo kufuneka ithathwe kubantu abancinci abasweleke ngenxa yokugula okanye ukwenzakala kwaye ezi meko azizange zichaphazele intliziyo yabo nangayiphi na indlela. Isigulana esiza kufumana unyango kufuneka silingane nentliziyo yomnikeli ukuze sifumane ukufakelwa kwentliziyo. Oku kuthetha ukulinda ixesha elide. Njengenye indlela enokwenzeka, amandla okukwazi ukudala izihlunu ezintsha entliziyweni ngokwahlulahlula iiseli anokunika ithemba kwizigidi ezinentliziyo eyonakeleyo. Iinkqubo ezininzi ziye zavavanywa luluntu lwezenzululwazi, nangona kunjalo, iziphumo aziphumelelanga ukuza kuthi ga ngoku.
Kwisifundo esitsha esipapashwe kwiCell , abaphandi kwiYunivesithi yaseCalifornia, eSan Francisco, e-USA okokuqala baphuhlise indlela esebenzayo nezinzileyo kwiimodeli zezilwanyana ukwenza iiseli zentliziyo zabantu abadala (ii-cardiomyocytes) zahlukane kwaye ngaloo ndlela zinokulungisa inxalenye eyonakeleyo yentliziyo 1. Ababhali bachonge iijini ezine ezibandakanyeka kulwahlulo lweeseli (oko kukuthi iiseli eziphindaphindana ngokwazo). Xa ezi jini zadityaniswa neejini ezibangela ukuba ii-cardiomyocytes ezivuthiweyo zingene kwakhona kumjikelo weseli, babona ukuba iiseli zazahlula kwaye zizalana. Ke, xa umsebenzi wezi jini zine ezibalulekileyo waphuculwa, izicubu zentliziyo zabonisa ukuvuselelwa. Emva kokusilela kwentliziyo kwisigulana, olu nxibelelwano luphucula ukusebenza kwentliziyo. Ii-cardiomyocytes zibonise ulwahlulo lwe-15-20 ekhulwini kuphononongo lwangoku (xa kuthelekiswa ne-1 ekhulwini kwizifundo zangaphambili) eziqinisa ukuthembeka nokusebenza kakuhle kolu phononongo. Olu phononongo lunokwandiswa ngobuchwephesha kwezinye izitho kuba ezi jini zine luphawu oluqhelekileyo. Lo ngumsebenzi obalulekileyo kakhulu kuba naluphi na uphando entliziyweni okokuqala luyinkimbinkimbi kakhulu kwaye okwesibini ukuhanjiswa kweejini kufuneka kwenziwe ngononophelo ukuze kungabangela naziphi na iithumba emzimbeni. Lo msebenzi ungajika ube yindlela enamandla kakhulu yokuvuselela intliziyo kunye nezinye izitho zomzimba.
Olunye uphando olwenziwe yiStem Cell Institute, kwiYunivesithi yaseCambridge, e-UK, luphuhlise indlela entsha yokulungisa izicubu zentliziyo ngendlela yokuba kungadingeki umxhasi kwaphela . 2. Basebenzise ii-stem cells ukukhulisa iziqwenga eziphilayo "zemisipha yentliziyo" kwilebhu eziziisentimitha ezi-2.5 kuphela kodwa zibonakala njengesixhobo esinamandla sokunyanga izigulana ezinesifo sentliziyo. Ezi ziqwenga zinethuba eliqaqambileyo lokungena ngokwemvelo entliziyweni yesigulana oko kukuthi sisicwili "esisebenza ngokupheleleyo" esibetha kwaye sincipha njengesicwili sentliziyo esiqhelekileyo. Indlela yangaphambili yokufaka ii-stem cells emzimbeni ukulungisa intliziyo ayiphumelelanga kuba ii-stem cells azizange zihlale kwisicwili sentliziyo kodwa endaweni yoko zalahleka egazini. Isicwili sangoku sisicwili sentliziyo "esiphilayo" ne "esibethayo" esinokunamatheliswa kwilungu (kule meko intliziyo ) kwaye ngaloo ndlela nawuphi na umonakalo unokulungiswa. Ezi ziqwenga zinokukhuliswa xa kukho imfuneko yesigulana. Oku kuya kudlula isidingo sokulinda umxhasi ohambelanayo. Ezi patches zingakhuliswa kusetyenziswa iiseli zesigulana sentliziyo ukuze kususwe iingozi ezibandakanyeka ekufakweni kwezitho zomzimba. Ukufaka ipatches entliziyweni eyonakeleyo yinkqubo yokuhlasela kwaye kufuna iimpulselelo zombane ezifanelekileyo ukuze intliziyo ibethe kakuhle xa idibene nepatches. Kodwa iingozi ezibandakanyekayo kolu hlobo lwenkqubo zingcono kunokufakelwa intliziyo iyonke ehlaselayo kakhulu. Iqela lilungiselela iimvavanyo zezilwanyana kunye novavanyo lweklinikhi kwiminyaka emi-5 ngaphambi kokuba oku kusetyenziswe kakhulu kwizigulana zentliziyo.
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Umthombo (s)
1. UMohamed et al. 2018,. Ulawulo loMjikelo weeSeli ukuze kukhuthazwe ukwanda kweCardiomyocyte yabantu abadala kunye nokuvuselelwa kwentliziyo. Iseli . https://doi.org/10.1016/j.cell.2018.02.014
2. IYunivesithi yaseCambridge ngo-2018. Ukulungisa intliziyo ephukileyo. http://www.cam.ac.uk/research/features/patching-up-a-broken-heart . [Ifikelelwe ngoMeyi 1, 2018]
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