本帖最後由 goodcat1111 於 2009-4-30 14:53 編輯
作者：Laurie Barclay, MD
出處：WebMD醫學新聞
April 15, 2009 — 根據發表於4月15日美國醫學會期刊的一篇回顧文獻，人類胰島細胞的細胞生物研究，對於發展糖尿病患治療選項與提供預防發生此一疾病是相當重要的。雖然本文是針對醫師、基礎科學研究者、分配胰島細胞研究資金的執政者，器官勸募者也可藉此鼓勵捐贈者家人授權同意研究。
加州希望之城國家醫學中心的John S. Kaddis等人寫道，胰島細胞研究的主要目標是治癒糖尿病。或許此類研究最顯著的臨床運用是細胞取代治療。除了1例運用在第2型糖尿病患，胰島移植主要用於第1型糖尿病患，目前顯示可以改善葡萄糖控制，在少數案例中，可獲得免除對胰島素的依賴。
可以使用beta細胞和細胞線、人類或非人類的胰臟衍生分離胰島來研究人類胰島的生物學。為了增加beta細胞量，可以在實驗和臨床使用胰島與類胰島細胞，研究與治療用的胰臟胰島需要量增加。捐贈胰腺以產生人類胰島的需求增加。
國家胰島資源(ICR)中心聯合會的目標，是供應人類胰島運用於糖尿病研究，與幫助發展更佳的胰島分離與移植技術。它成立於2001年，之後此聯合會提供給151名國內與國際科學家29,760萬個胰島供臨床與實驗室研究之用。在2008年8月，182 個臨床與基礎科學計畫申請此聯合會的協助。
獲得胰腺所需的高花費已經成為生產胰島的阻礙。根據ICR中心聯合會的資料，2001至2008年獲得的665個胰腺中，獲得的費用從600美元到39,800美元不等。
人類胰島對於糖尿病研究的重要性，可以從ICR中心聯合會在質量與運送頻率的資料窺見，以及從使用這些胰島進行的beta細胞計畫與發表和資金得知。在2001年9月至2008年8月間，14個ICR實驗室生產了29,760萬個胰島，其中67%用於基礎科學研究、31%用於治療用途。
這篇回顧討論人類胰島研究與治療用途的固有限制。胰島移植顯示可免於發生糖尿病長期併發症，顯著改善生活品質。不過，其他臨床成功的阻礙包括移植期有限、長期免疫抑制、人類胰島供應不一致，這些在進行胰島移植前都需釐清，以及仔細篩選病患進行標準照護。
已經建立胰島分享網絡以加速對胰島實驗室和臨床科學家與實驗學者的供應，未來的挑戰應正視胰島配送中心的分布。
回顧作者寫道，這些分布網絡對於糖尿病研究有整體影響力，但是得面對維持獲得人類胰島以滿足日益增加的需求的經濟阻力。人類胰島細胞對於重建糖尿病患的beta細胞功能是至關重要的。即使有適當的資金，供應人類胰島細胞以成功探究治療此慢性疾病依舊是個挑戰。
國家研究資源中心(NCRR)以及美國國家健康研究中心的國家糖尿病與消化道、腎臟疾病研究中心、青少年糖尿病研究基金會支持本研究。研究作者中有5人接受NCRR的資金支持。
More Research on Pancreatic Islet Cells Needed for Diabetes Treatment, Prevention Options
By Laurie Barclay, MD
Medscape Medical News
April 15, 2009 — Research to clarify the cellular biology of human pancreatic islet cells is vital to developing therapeutic options for patients with diabetes and to efforts aimed at preventing development of this disease, according to an overview article published in the April 15 issue of the Journal of the American Medical Association. Although the article is aimed at clinicians, basic science researchers, and policy makers who allocate funding for islet cell research, organ procurement coordinators may also benefit from this information when encouraging donor families to give research consent.
"The primary objective of islet-based research is to cure diabetes," write John S. Kaddis, BS, from the City of Hope National Medical Center in Duarte, California, and colleagues."Perhaps the most prominent clinical application of this research is currently in the form of cell replacement therapy. With the exception of 1 report in a type 2 diabetic cohort, islet transplantation has been used exclusively for a subset of individuals with type 1 diabetes mellitus and was shown, at least temporarily, to improve glucose control and, in a few cases, to lead to insulin independence."
The biology of human islets can be studied using surrogate beta cells and cell lines or pancreas-derived isolated islets from human or nonhuman sources. To increase beta-cell mass, islets and islet-like cells have been used experimentally and clinically, and demand for pancreatic islets has been increasing both for research and for treatment. Growing numbers of donor pancreata are needed for production of human islets.
The goals of the national Islet Cell Resource (ICR) Center Consortium are to supply human pancreatic islets for diabetes research and to help develop better technologies for islet isolation and transplantation. Since it was founded in 2001, this consortium has provided 151 national and international scientists with 297.6 million islet equivalents for use in clinical and laboratory research. Through August 2008, 182 clinical and basic science projects were submitted to the consortium for support.
The high cost of acquiring pancreata has posed a substantial obstacle to islet production. For 665 pancreata acquired from 2001 to 2008, standard acquisition charges varied from as low as $600 to as high as $39,800, according to data from the ICR Center Consortium.
The importance of human islets for diabetes research is confirmed by data on the volume, quality, and frequency of shipments by the ICR Center Consortium, as well as by the number of funded grants for beta-cell projects and publications directly resulting from research using these islets. Between September 2001 and August 2008, 297.6 million islets were produced by 14 ICR laboratories, of which 67% were used for basic science studies and 31% for therapeutic purposes.
The review discusses limitations inherent in human islet research and therapeutic use. Islet transplantation has been shown to protect against development of long-term complications of diabetes and to improve quality of life significantly. However, remaining obstacles to clinical success include limited engraftment, chronic immunosuppression, and inconsistent supply of human islets, which must be addressed before islet transplantation can be considered the standard of care in carefully selected patients.
Islet sharing networks have been established to facilitate supply to islet laboratories and clinical and laboratory scientists, but future challenges confronting islet distribution centers must be addressed.
"These distribution networks have had a global influence on diabetes research but face economic obstacles in preserving the availability of human islets in a growing research community," the review authors write. "Human pancreatic islets will be critical for restoration of beta-cell function in patients with diabetes. Even given adequate funding levels, the ongoing challenges to supplying human islets must be addressed for the successful exploration of therapeutic options for this chronic and debilitating disease."
The National Center for Research Resources (NCRR) and the National Institute of Diabetes and Digestive and Kidney Diseases, components of the US National Institutes of Health, supported this study, along with contributions from the Juvenile Diabetes Research Foundation. Five of the study authors are supported by grants from NCRR.
JAMA. 2009;301:1580–1587. |
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