Kule nkwenkwezi ezininzi, ubomi buye malunga nokuveliswa. Kwinqanaba lezinto eziphilayo, izinto ezinjengabantu, iifungi, izityalo kunye neebhaktheriya zinokucingwa njengeendlela eziphambili zeeprotheni zeendlela ze-deoxyribonucleic acid (DNA) ukuzikopisha ngokwaneleyo.
Enyanisweni, ukuqhuba ukuvelisa kwanokwandisa ngaphandle kwezinto eziphilayo. Iintsholongwane ngumzekelo we-limbo engaqhelekanga phakathi kwabaphilileyo nabangabikhoyo.
Ngendlela, intsholongwane ingaphantsi komatshini wokuzala. Kwiimeko zezinye iintsholongwane, njengegciwane lesandulela ngculazi (i- HIV ), i-DNA ayikho i-molecule eyenza ukuvelisa. Enye i-nucleotide, i-RNA (ribonucleic acid), yinto yokuqhuba.
Yiyiphi i-Prion Disease?
Iiproon (ezibizwa nge-pree-ons e-US, i-pry-ons e-UK) ziyakususwa kwakhona kwiindlela ezinokuqonda zokuvelisa ezibandakanya iDNA ne-RNA. I-DNA ne-RNA ziyi-nucleotides, isakhiwo seekhemikhali esetyenziselwa ukwenza iiprotheni, iibhloko zokwakha eziphilayo ezilungiselelwe ukuvelisa ngokuphumelelayo. I-prion yiprothini engadingi i-nucleotide ukuba ivelise-i-prion ingaphezu kokukwazi ukuzinyamekela.
Xa iprotheni ye-prion ephosakeleyo ingena kwiprothini eqhelekileyo, iprotheni eqhelekileyo iguqula ibe yinye into ebangela ukuba isifo esibangele isifo. Isiphumo sisininzi esingenasiphelo seprotheyini eguquguqukayo.
Kwiimeko zesifo se-prion esizuze njengefa, kukuguquka kwemfuyo ebangela ukulandelwa okungavamile kwiprotheni ye-prion. Ngelishwa, ezi zi-proteins ezifanayo ezisetyenziswe ngamaseli engqondo ukuze zisebenze ngokufanelekileyo, kwaye iiseliti ze-nerve ziyafa ngenxa yoko, ezikhokelela ekudemeni kwengqondo ngokukhawuleza. Nangona i-prion yokubangela isifo ikwazi ukulala iminyaka emininzi, xa iimpawu zigqibeleni zibonakala, ukufa kunokulandela ngokukhawuleza nje ngeenyanga ezimbalwa.
Kukho iintlobo ezi-5 eziphambili zezifo zokuqala ezibonakalayo kubantu: I- Creutzfeldt-Jakob isifo (CJD), isifo seCreutzfeldt-Jakob (vCJD), i-kuru, i-Ger, i-Gerstmann-Straussler-Scheinker syndrome (GSS), kunye nokufa kweentsapho ezibulalayo (FFI). Nangona kunjalo, iifom ezintsha ze-prion zifunyanwa.
Indlela abaphuhlisa ngayo
Izifo ze-Prion zingafumaneka ngeendlela ezintathu: zentsapho, zifunyenwe, okanye zenzekile. Indlela eqhelekileyo yokuhlakulela isifo se-prion ibonakala ihamba ngokukhawuleza, kungekho mthombo wentsholongwane okanye ilifa. Malunga nesinye kwisigidi abantu bahlakulela olu hlobo oluqhelekileyo lwesifo se-prion. Ezinye izifo ze-prion, njenge-CJD, i-GSS, ne-FFI, ingaba nefa. Abanye basasazwa ngokuqhagamshelana okufutshane kunye neprothini ye-prion. Ngokomzekelo, u-kuru wasasazwa ngamasiko angabikho kwiNew Guinea. Xa iibilini zidliwa njengenxalenye yesithethe, izibhononongo zatshiswa, kwaye eso sifo sasiza kusasazeka. Umzekelo omncinci kakhulu ngu-vCJD, owaziwayo ukusasazeka kwizilwanyana kubantu xa sisitya inyama. Oku kuyaziwa ngokuba "isifo seenkomo," kwaye kwenzeka xa i-prion ikhona kwinkomo ephilileyo. Ezinye izilwanyana, ezifana ne-elk kunye neegusha, ziye zafunyaniswa ngamanye amaxesha zihlala zizifo ze-prion. Nangona kungavamile, izifo ze-prion nazo zingasasazeka kwizixhobo zokucanda.
Iimpawu
Ngelixa zonke izifo ze-prion zibangele iimpawu ezahlukileyo, zonke iibhonononi zibonakala zinomdla okhethekileyo kwinkqubo ye-nervous. Nangona iintsholongwane zamagciwane okanye iintsholongwane ezivakalayo ezivakalayo kwiindawo ezininzi ezahlukeneyo zomzimba-kubandakanya izifo zengqondo-prion zibonakala zibangele kuphela iimpawu ze-neurological kubantu, nangona iiprotheyini ngokwazo zingatholakala kwiindawo ezahlukeneyo zomzimba. Ixesha linokubonisa ukuba indlela efana ne-prion isemva kwezifo ezingaphandle kwengqondo.
Igalelo kwinkqubo yeentlanzi iphawulekayo. Izifo ezininzi ze-prion zibangelwa oko kwaziwa ngokuba yi-spongiform encephalopathy.
Igama elithi spongiform lithetha ukuba lesi sifo siphuca izicubu zengqondo, kudala izimbobo ezincinci ezenza ukuba izicubu zibukeke njengentonga. Ngokuqhelekileyo, isiphumo sokugqibela sisifo sengqondo sokunyuka kwengqondo ngokukhawuleza, oku kuthetha ukuba ixhoba lilahlekelwa yikhono lakhe lokucinga njengoko wayesebenzisa kwinyanga ethile kwiminyaka embalwa. Ezinye iimpawu ziquka ukuxhamla ( ataxia ), ukunyuka okungavumelekanga okufana ne-chorea okanye intshukumo , kunye neendlela zokulala.
Enye yezinto eziyikrakra malunga nesifo se-prion kukuba kukho ixesha elide lokukhutshulwa phakathi kokuba umntu evelele kwi-prion kwaye xa ekhula iimpawu. Abantu banokuhamba iminyaka ngaphambi kokuba iibhonari eziye zithwele zibonakala zicacile, kunye neengxaki ze-neurological.
Unyango
Ngelishwa, akukho nonyango yesifo se-prion. Eyona nto ingcono, oogqirha banokuzama ukunceda ukulawula iimpawu ezibangelwa ukungahambi kakuhle. Kwisifundo esincinci saseYurophu, imithi eyenza iFlupirtine (ayifumaneki eUnited States) yaphucula ngcamango izigulane ngeCJD kodwa ayizange iphuculise ubomi babo. Uvavanyo lwezilwanyana ze-chlorpromazine kunye ne-quinacrin alubonanga uphuculo. Ngeli xesha, izifo ze-prion zihlala zifa.
Imithombo:
Geschwind MD, Shu H, Hamani A, Sejvar JJ, Miller BL. Ukugula kwengqondo ngokukhawulezayo. Ama-Annal of Neurology 2008; 64: 97-108.
AH Ropper, amaSamuels MA. I-Adams kunye neMigaqo yeVictor ye-Neurology, 9th: I-McGraw-Hill Companies, Inc., 2009