Sél punca: Béda antarrépisi

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Stem cells, however, are already used extensively in research, and some scientists do not see cell therapy as the first goal of the research, but see the investigation of stem cells as a goal worthy in itself. <ref>{{cite web | author = Wade N | title = Some Scientists See Shift in Stem Cell Hopes | publisher = New York Times | url=http://www.nytimes.com/2006/08/14/washington/14stem.html | date=2006-08-14 | accessdate=2006-12-28}}</ref>.
Stem cells, however, are already used extensively in research, and some scientists do not see cell therapy as the first goal of the research, but see the investigation of stem cells as a goal worthy in itself. <ref>{{cite web | author = Wade N | title = Some Scientists See Shift in Stem Cell Hopes | publisher = New York Times | url=http://www.nytimes.com/2006/08/14/washington/14stem.html | date=2006-08-14 | accessdate=2006-12-28}}</ref>.


==Kontroversi panalungtikan sél sirung==
==Controversy surrounding stem cell research==
⚫
Panalungtikan sél sirung téh ti anggalna mula teu weléh dirungrum ku kontroversi, utamana mah dina téhnis nyipta jeung migunakeun sél sirungna. Panalungtikan [[sél sirung émbrionik]] research is particularly controversial because, with the present state of technology, starting a [[stem cell line]] requires the destruction of a [[embryo|human embryo]] and/or [[therapeutic cloning]]. Opponents of the research argue that this practice is a [[slippery slope]] to [[reproductive cloning]] and tantamount to the [[instrumentalization]] of a [[human being]]. Contrarily, medical researchers in the field argue that it is necessary to pursue embryonic stem cell research because the resultant technologies are expected to have significant medical potential, and that the embryos used for research are only those meant for destruction anyway (as a product of [[invitro fertilisation]]). This in turn, conflicts with opponents holding an [[anti-abortion]] stance, who argue that an embryo is a human being and therefore entitled to dignity even if legally slated for destruction. The ensuing debate has prompted authorities around the world to seek regulatory frameworks and highlighted the fact that stem cell research represents a [[social]] and [[ethical]] challenge.-->
{{main|Stem cell controversy}}
⚫
There exists a widespread controversy over stem cell research that emanates from the techniques used in the creation and usage of stem cells. [[Embryonic stem cell]] research is particularly controversial because, with the present state of technology, starting a [[stem cell line]] requires the destruction of a [[embryo|human embryo]] and/or [[therapeutic cloning]]. Opponents of the research argue that this practice is a [[slippery slope]] to [[reproductive cloning]] and tantamount to the [[instrumentalization]] of a [[human being]]. Contrarily, medical researchers in the field argue that it is necessary to pursue embryonic stem cell research because the resultant technologies are expected to have significant medical potential, and that the embryos used for research are only those meant for destruction anyway (as a product of [[invitro fertilisation]]). This in turn, conflicts with opponents holding an [[anti-abortion]] stance, who argue that an embryo is a human being and therefore entitled to dignity even if legally slated for destruction. The ensuing debate has prompted authorities around the world to seek regulatory frameworks and highlighted the fact that stem cell research represents a [[social]] and [[ethical]] challenge.-->


==Hambalan penting dina panalungtikan sél sirung==
==Hambalan penting dina panalungtikan sél sirung==

Révisi nurutkeun 17 Januari 2007 04.44

Sél sirung émbrionik beurit maké panyiri fluoreséns.

Sél sirung (stem cells) hartina sél mimiti nu ilaharna aya di sakabéh organisme multisél nu mibanda kamampuh nganyarkeun manéh ku cara meulah diri sarta bisa dididefensiasi jadi rupa-rupa tipe sél. Panalungtikan dina widang sél sirung manusa dimimitian ku papanggihan élmuwan Kanada, Ernest A. McCulloch jeung James E. Till taun 1960-an.[1][2]

Sél sirung mamalia sacara umum dibagi kana dua kategori: sél sirung émbrionik (diturunkeun tina blastosis) jeung sél sirung sawawa (tina jaringan mamalia sawawa). Dina émbrio nu keur mekar, sél sirung bisa ngalaman diferensiasi jadi sagala rupa jaringan émbrio. Dina organisme sawawa, sél sirung jeung sél turunanana meta salaku sistim omé pikeun sél-sél dina awak.

Kusabab bisa tumuwuh sarta dirobah jadi jaringan husus modél otot atawa saraf, sél sirung ditalungtik kabisana pikeun natambaan kasakit genetik. Kandidat utamana mah nyaéta garis sél émbrionik, sél sirung émbrionik otolog nu dihasilkeun tina kloning terapeutik, sarta sél sirung tina getih ari atawa sungsum tulang.[3]

Pasipatan sél sirung

Pasipatan panangtu

Ambahan harti sél sirung anu lega diwatesan ku dua pasipatan:

  • Nganyarkeun manéh (self-renewal) - bisa ngalaman sababaraha kali daur meulah sél bari teu ngalaman diferensiasi.
  • Poténsi tanpa wates (unlimited potency) - bisa ngalaman diferensiasi jadi tipe sél sawawa naon baé.

Pedaran poténsi

Sél sirung émbrionik pluripotén salaku sél massa jero dina blastosis. Sél sirung bisa jadi jaringan naon baé dina awak, iwal bali. Ukur sél morula nu totipotén nu bisa jadi sagala rupa sél kaasup bali.

Poténsi ngécéskeun poténsial diferensiasi (poténsi pikeun ngalaman diferensiasi jadi rupa-rupa tipe sél) sél sirungna.

  • Sél sirung totipotén dihasilkeun tina ngahijina sél endog jeung spérma. Sél nu dihasilkeun tina sababaraha beulahan awal endog nu geus dibuahan ogé masih totipotén. Sél-sél ieu bisa ngalaman diferensiasi jadi tipe-tipe sél émbrionik jeung ékstraémbrionik.
  • Sél sirung pluripotén diturunkeun tina sél totipotén nu bisa ngalaman diferensiasi jadi sél-sél nu diturunkeun tina tilu germ layer.
  • Sél sirung multipotén ukur bisa ngahasilkeun sél anu sakulawarga deukeut kénéh (misalna sél sirung hématopoietik ngalaman diferensiasi jadi sél getih beureum, sél getih bodas, platélét, jsb.).
  • Sél unipotén ukur bisa ngahasilkeun hiji tipe sél, tapi masih boga pasipatan nganyarkeun manéh nu ngabédakeun éta sél ti sél non-sirung.

Hambalan penting dina panalungtikan sél sirung

  • 1960-an - Joseph Altman jeung Gopal Das némbongkeun bukti neurogenesis sawawa, kagiatan sél sirung dina uteuk; laporan aranjeunna patukang tonggong jeung dogma "euweuh neuron anyar"-na Cajal, sahingga harita mah teu dianggap
  • 1963 - McCulloch jeung Till ngagambarkeun ayana sél nu nganyarkeun manéh dina sungsum tulang beurit
  • 1968 - cangkok sungsum tulang antara dua adi-lanceuk kabukti bisa natambaan SCID
  • 1978 - Sél sirung Hématopoietik kapanggih dina getih ari manusa
  • 1981 - Sél sirung émbrionik beurit diturunkeun tina massa sél jero
  • 1992 - Sél sirung saraf/neural dibudidayakeun in vitro salaku neurosfir
  • 1995 - Présidén Bill Clinton nyatujuan Amandemén Dickey nu nyaram ayana anggaran federal pikeun kagiatan panalungtikan anu maké émbrio manusa.
  • 1997 - Leukemia kapanggih asalna tina sél sirung hématopoietik, bukti munggaran ayana sél sirung kangker
  • 1998 - James Thomson saparakanca ngembangkeun garis sél sirung émbrionik munggaran di Universitas Wisconsin-Madison.
  • 2000-an - Sababaraha laporan ngeunaan plastisitas sél sirung sawawa dipublikasi.
  • 2003 - Dr. Songtao Shi ti NIH manggihan sumber anyar sél sirung sawawa tina huntu susu[4]
  • 02 Nopémber 2004 - California nyatujuan Proposisi 71 nu nyadiakeun anggaran nagara $3 miliar pikeun panalungtikan sél sirung émbrionik manusa.
  • 2004-2005 - Panalungtik Koréa Hwang Woo-Suk ngaku geus ngembangkeun sababaraha garis sél sirung émbrionik manusa tina oosit manusa nu can dibuahan. Kadieunakeun kabuktian garis sél éta palsu.
  • 2005 - Para panalungtik ti Universitas Kingston, Inggris ngaku geus manggihan sResearchers atl sirung kategori tilu, nu dilandih cord-blood-derived embryoniclike stem cells (CBEs, sél sirung mirip émbrionik), diturunkeun tina getih ari-ari. Kelompok ieu nyebutkeun yén sél-sél ieu bisa didiferensiasi jadi rupa-rupa tipe sél nu leuwih lengkep batan sél sirung sawawa.
  • 2001-2006 - Présidén George W. Bush ngadukung Kongres pikeun nyadiakeun anggaran féderal pikeun panalungtikan sél sirung émbrionik nu kabéhna ampir $100 juta.

Rujukan

  • Stem cell, Wikipédia édisi basa Inggris (per 16 Januari 2007)
  1. ↑ Becker AJ, McCulloch EA, Till JE (1963). "Cytological demonstration of the clonal nature of spleen colonies derived from transplanted mouse marrow cells". Nature 197: 452-4. PMID 13970094. 
  2. ↑ Siminovitch L, McCulloch EA, Till JE (1963). "The distribution of colony-forming cells among spleen colonies". Journal of Cellular and Comparative Physiology 62: 327-36. PMID 14086156. 
  3. ↑ Tuch B (2006). "Stem cells--a clinical update.". Aust Fam Physician 35 (9): 719-21. PMID 16969445. 
  4. ↑ Shostak S (2006). "(Re)defining stem cells". Bioessays 28 (3): 301-8. PMID 16479584. 

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