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【medical-news】糖尿病“被干细胞阻拦”
04/11/07 -- People with the condition are known as insulin-dependent, and require regular shots of the hormone.
But 14 out of 15 young people newly diagnosed with the condition no longer needed injections - sometimes for years - following the stem cell treatment.
However, experts warned the Journal of the American Medical Association study was preliminary and inconclusive.
Type 1 diabetes is caused by the patient's own immune system destroying insulin-producing cells in the pancreas.
The researchers, from the University of Sao Paulo, gave the patients powerful drugs to suppress their immune systems in an attempt to stop further destruction of pancreatic cells.
This was followed by transfusions of stem cells taken from their own blood, in effect designed to restart the immune system.
Some patients reacted more quickly to the treatment than others, and the length of the effect also varied.
One patient was able to survive without insulin injections for 35 months, and four others for at least 21 months.
Two patients who responded late did not have to inject themselves for one and five months.
Mechanism unclear
Previous studies have suggested stem cell therapy might be a promising approach for type 1 diabetes.
Stem cells are immature cells which can become different types of adult tissue.
It is thought that in this instance the stem cells may have generated new immune cells which do not target the pancreas, helping to safeguard what remaining insulin-producing cells the patient has left.
However, it is also possible that the treatment may have led to the growth of new insulin-producing beta cells in the pancreas.
A third possibility is that the treatment stimulated an as yet unknown mechanism which stopped existing beta cells being destroyed.
The results do throw up the possibility that stem cell therapy could have a dramatic impact.
'Preliminary study'
But the study was small, did not monitor the patients for very long and did not compare them with similar patients who were given alternative therapy or remained untreated.
Dr Iain Frame, of the charity Diabetes UK, warned against raising people's hopes on the basis of a "very preliminary" study.
"It is well known that there is often a honeymoon period of relative remission after the onset of Type 1 diabetes that complicates the interpretation of results such as the ones shown in this study.
"All these issues need to be addressed through more research before there are any conclusive findings in this area."
Dr Richard Burt, of Northwestern University, Chicago, who worked on the study, said: "I do not use the word cure, or the word breakthrough, but this is a step forward.
"It is the first time in which a stem cell therapy has been used effectively in this disease."
Previous research has suggested that stem cell therapy can benefit patients with other auto-immune diseases, such as rheumatoid arthritis and Crohn's.
Of the 2.2 million people with diabetes in the UK, only around 300,000 have the type 1 disease.
However, for unknown reasons, the number of British children under the age of five developing type 1 diabetes has risen five-fold in the last 20 years.
Source: *** News
http://www.bio.com/newsfeatures/newsfeatures_research.jhtml;jsessionid=W1D0WMZYLLMPHR3FQLMCFEWHUWBNSIV0?cid=28200038 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领。 干细胞可以“阻止”糖尿病
04/11/07 胰岛素依赖的糖尿病患者需要规律的注射胰岛素。但是15个新诊断的年轻人中有14人在采用干细胞移植后几年内不需要注射胰岛素。
但是，专家提醒我们美国医学协会杂志的研究是最初的研究，尚没有一致性结论。
1型糖尿病的病因是自身免疫系统破坏了胰腺内胰岛素分泌细胞。
圣保罗大学的研究者先采用大量免疫抑制剂，试图阻止胰腺细胞的进一步破坏。接着将从患者自体血细胞内得到的干细胞输入体内，这样实际上是有意再次激活患者的免疫系统。
一些患者对治疗发生了比别人要早的反应。疗效持续的时间也各不相同。
其中一个病人不需要胰岛素治疗时间长达35个月，4个病人持续了21个月。
2个病人发生了延迟反应，分别于1月和5月后再次开始应用胰岛素。
目前机制尚不清楚。
以前的研究认为干细胞有希望用于治疗1型糖尿病。
干细胞是未成熟细胞，它可以分化为多种成体细胞。
本研究认为干细胞可能产生了新的、不作用于胰腺的免疫细胞，有利于保护胰腺剩余的胰岛素分泌细胞。
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作者:admin@医学,生命科学 2011-03-01 17:11
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