Kwabaningi ososayensi, impilo iyonke mayelana nokukhiqiza. Ngezinga lezinto eziphilayo, izilwane ezinjengabantu, isikhunta, izitshalo, nama-bacteria zingacatshangwa njengezindlela eziphambili zeprotheni ezisekelwe ku-deoxyribonucleic acid (i-DNA) ukuzikopisha ngokwengeziwe.
Empeleni, ukushayela ukukhiqiza ngisho nokudlulisa ngaphandle kwezinto eziphilayo. Ama-virus anesibonelo se-limbo engavamile phakathi kwabaphilayo nabangabikho.
Ngandlela-thile, igciwane lingaphezu komshini wokuzala. Ezimweni ezithile zegciwane, njenge-virus immunodeficiency virus (i- HIV ), i-DNA ayiyona i-molecule eqhuba ukukhiqiza. Enye i-nucleotide, i-RNA (ribonucleic acid), iyisici sokushayela.
Kuyini Isifo Se-Prion?
Ama-Prions (ama-pree-on eyaziwa e-US, ama-pry-on e-UK) aphinde asuswe eminye indlela eqondwa kangcono yokukhiqiza okubandakanya i-DNA ne-RNA. I-DNA ne-RNA yi-nucleotides, isakhi samakhemikhali esetshenziselwa ukwenza amaprotheni, izakhi zokwakha eziphilayo ezihloselwe ukuqinisekisa ukukhiqizwa okuphumelelayo. I-prion iphrotheni engadingi i-nucleotide ukuba ibelethe-i-prion ingaphezu kokukwazi ukuzizinakekela.
Uma iphrotheni ephepheni engavamile egijimela iphrotheni evamile, iphrotheni evamile iguqula ibe yinye i-prion ephazamisa izifo ezingavamile. Umphumela uwukuhlaselwa okungapheli kweprotheyini eguquguqukayo.
Ezimweni zezifo ze-prion ezizuzwe njengefa, kungukushintshashintsha kwezakhi zofuzo okubangela ukufakwa okungavamile kweprothini ye-prion. Ngeshwa, lawa amaprotheni afanayo asetshenziswa amangqamuzana obuchopho ukuze asebenze kahle, futhi amangqamuzana amaningi anesisindo afe ngenxa yalokho, okuholela ekumenikeni kwengqondo okuqhubekayo ngokushesha. Ngenkathi i-prion edala izifo ingase ibeke isikhathi eside, lapho izimpawu zigcina zibonakala, ukufa kungase kulandele ngokushesha ezinyangeni ezimbalwa.
Kunezinhlobo ezinhlanu eziyinhloko zezifo ze-prion ezibonakalayo kubantu: i- Creutzfeldt-Jakob isifo (CJD), i-Creutzfeldt-Jakob isifo (vCJD), i-kuru, i-Ger, i-Gerstmann-Straussler-Scheinker syndrome (GSS), nokulala nokushaywa komzimba okubulalayo (FFI). Noma kunjalo, kutholakala izinhlobo ezintsha zezifo ze-prion.
Indlela Abathuthukisa ngayo
Izifo ze-Prion zingatholakala ngezindlela ezintathu: ezomndeni, ezitholakalayo, noma ezincane. Indlela ejwayelekile kakhulu yokuthuthukisa isifo se-prion kubonakala sengathi ikhona, ngaphandle komthombo wesifo noma ifa. Cishe eyodwa kubantu abayizigidi bahlakulela leli fomu elivame kakhulu lesifo se-prion. Ezinye izifo ze-prion, njenge-CJD, i-GSS, ne-FFI, zingazuzwa njengefa. Ezinye zisakazwa ngokuxhumana okufutshane neprothini ye-prion. Isibonelo, i-kuru yasakazwa yizinkolelo ezingenasidingo eNew Guinea. Lapho ubuchopho budliwa njengengxenye yesiko, ama-prions ayengenwa, futhi lesi sifo sasiyosakazeka. Isibonelo esingavamile kakhulu i-vCJD, eyaziwa ukuthi isakazeka ezilwaneni kubantu uma sidla inyama. Lokhu kuvame ukubizwa ngokuthi "isifo sezinkomo," futhi kwenzeka lapho i-prion ikhona enkabeni ephilayo. Ezinye izilwane, ezinjenge-elk nezimvu, nazo zitholakale ngezinye izikhathi ziphethe izifo ze-prion. Nakuba kungavamile, izifo ze-prion nazo zingasakazwa ezindaweni zokuhlinzwa.
Izimpawu
Nakuba zonke izifo ze-prion zidala izimpawu ezihlukile, zonke izikhonkwane zibonakala zithandwa kakhulu ohlelweni lwezinzwa. Nakuba ukutheleleka kwama-bacteria noma ama-virus okuvame ukuzwa ezinxenyeni eziningi zomzimba-kuhlanganise nezifo zobuchopho-prion kubonakala sengathi kubangela izimpawu ze-neurological kubantu, nakuba amaprotheni ngokwabo angatholakala ezinhlobonhlobo eziningi zomzimba. Isikhathi singabonisa ukuthi indlela efana no-prion ilandela izifo ezingaphandle kobuchopho.
Umthelela ohlelweni lwezinzwa luyinkimbinkimbi. Izifo eziningi ze-prion zidala ukuthi yini eyaziwa ngokuthi i-spongiform encephalopathy.
Igama elithi spongiform lisho ukuthi lesi sifo siphuca izicubu zobuchopho, kudala izimbobo ezincane ezenza izicubu zibukeke njengeponji. Ngokuvamile, umphumela wokuphela ukukhula komqondo okuqhubekayo okuqhubekayo, okusho ukuthi isisulu silahlekelwa ikhono lakhe lokucabanga njengoba ayevame ezinyangeni ezinyangeni ezimbalwa. Ezinye izimpawu zihlanganisa ukuxuba (i- ataxia ), ukunyakaza okungavamile okufana ne-chorea noma ukuzamazama , nokushintsha amaphethini okulala.
Enye yezinto ezesabekayo mayelana nesifo se-prion yukuthi kungase kube nesikhathi eside sokukhulelwa phakathi komuntu lapho evezwa ku-prion nalapho eqala izimpawu. Abantu bangase bahambe iminyaka ngaphambi kokuba izikhwama ezithwalayo ziveze, nezinkinga ezijwayelekile zezinzwa.
Ukwelapha
Ngeshwa, akukho ukwelashwa kwezifo ze-prion. Ngcono kakhulu, odokotela bangazama ukusiza ukulawula izimpawu ezibangelwa ukungahambi kahle. Esicwaningweni esincane saseYurophu, imithi eyabangela iFlupirtine (ayitholakali e-United States) ngokuthobeka yenza ngcono ukucabanga ezigulini ezine-CJD kodwa ayizange ithuthukise ukuphila kwabo. Ukuhlolwa kwezidakamizwa ze-chlorpromazine ne-quinacrin akubonanga ngcono. Ngalesi sikhathi, izifo ze-prion zihlala zibulalayo emhlabeni jikelele.
Imithombo:
Geschwind MD, Shu H, Hamani A, Sejvar JJ, Miller BL. Ukucindezeleka okusheshayo okuqhubekayo. Ama-Annal of Neurology 2008; 64: 97-108.
I-AH Ropper, ama-Samuels MA. Adams kanye Nemigomo kaVictor ye-Neurology, 9th ed: The McGraw-Hill Companies, Inc., 2009