Man Free of HIV After Stem Cell Transplant

An American man living in Germany appears to have been free of both leukemia and the virus that causes AIDS since he had a stem cell transplant for his leukemia three years ago.

German researchers report in the medical journal Blood that the transplant patient now shows no sign of having leukemia or HIV, suggesting that the transplant cured him.

But scientists warn that the case does not have practical implications for the treatment of millions of HIV patients worldwide.

Doctors say that the stem cell donor had a rare gene mutation that protects him from being infected with the AIDS virus.

The patient, Timothy Ray Brown, had his own immune system weakened by high doses of chemo-therapy and had stopped anti-viral therapy to treat AIDS.

In 2007 a doctor in Berlin performed a bone marrow transplant on him, using stem cells from the HIV resistant donor.

The intervention is very risky and potentially deadly. But doctors say that after three years, the so-called “Berlin patient” shows no trace of either HIV or leukemia.

HIV researches say even though the procedure is too dangerous and therefore not widely applicable, it gives hope that a cure for HIV infections can be found.

Tags: Germany, HIV, US

Posted in "Europe"

干细胞移植消除了男子的艾滋病毒

杭州蓝翔生物科技有限公司, 干细胞研究所 郭品正 翻译

生活在德国的美国男子似乎已经同时治愈了白血病和艾滋病病毒，他三年前为治疗白血病做了干细胞移植。

德国研究人员在医学杂志血液学上报告说，移植病人现在没有显示出有白血病或艾滋病毒的迹象，这表明已经通过（干细胞）移植治愈了。

但科学家警告说，此案不具备为全世界数百万患者的艾滋病毒治疗的实际意义。

医生说，干细胞捐献者有一种罕见的基因突变，突变能保护被感染艾滋病病毒。

病人，蒂莫西瑞布朗（Timothy Ray Brown），自身的免疫系统因大剂量的化疗而遭到削弱，已经停止了抗病毒疗法来治疗艾滋病。

2007年在柏林的医生对他进行了骨髓移植手术，使用的干细胞来自于对艾滋病毒有抵抗力的供体。

干预是非常危险和潜在致命的。但医生说，三年后，所谓的“柏林病人“没有显示出任何艾滋病毒或白血病的痕迹。

艾滋病毒的研究说，即使该程序是太危险了，不能得到广泛的应用；但它给了希望—治愈艾滋病毒感染方法可以找到。
标签：德国，艾滋病病毒，美国

张贴在欧洲

标签：德国，艾滋病病毒，美国

张贴在“欧洲”

US Scientists Reverse Signs of Aging in Mice

Elderly mice restored to middle age

Jessica Berman | Washington, DC 01 December 2010

Harvard scientists say they were able to reverse signs of aging in mice by tweaking a gene which protects cells from the harmful, cumulative effects associated with growing old.

Scientists say they have reversed age-related degeneration in mice, resulting in an improvement in the rodents' fertility and the growth of new brain tissue. But it could be some time before the technique might be used in humans.

Fountain of youth

Scientists at Harvard University's Dana-Farber Cancer Institute in Boston report they were able to reverse signs of aging in mice by tweaking a gene that protects cells from the harmful, cumulative effects associated with growing old.

The gene is involved in the production of structures at the tips of DNA chromosomes called telomeres.

Telomeres are like the plastic caps on the ends of shoe laces that keep them from becoming frayed. In the case of chromosomes, the telomeres protect the strands of DNA from environmental assaults such as chemical and radiation exposure.

But every time a cell divides, its telemeres shorten, eventually leading to DNA damage and aging.

In studies with mice, researchers switched off the telomerase gene and watched the rodents rapidly develop age-related impairments.

Eternally young?

However, when they turned the genes back on on, the animals' declines reversed.

"Their fertility was restored. We also saw a big effect on the lining of the intestines and as well as in the brain, which was a little bit unexpected," says lead researcher Mariela Jaskelioff. "We actually saw a decrease in the size of the brains of these mice with premature aging. And we could reverse these by reactivating telomerase."

The mice in the study were at an age equivalent of an 80- or 90-year-old human. Researchers restored them to middle age by turning on the telomerase gene.

Despite the encouraging results, the genetic manipulation is not the secret to eternal youth for humans. Jaskelioff says the telomerase gene is involved in the growth of both normal and cancerous cells.

"The fear is that in humans, adult humans, we accumulate mutations all through our lifetimes," she says. "And if we were to reactivate telomerase in cells that have malignant mutations, then the propensity to develop cancer would probably be exacerbated."

However, according to Jaskelioff, it might be possible to stimulate the telomerase gene for short periods of time in people with a rare disorder which causes premature aging.

Scientists describe how they reversed aging in mice in an article published in the journal Nature Medicine.

Human testes cells may be turned into insulin-producing islet cells: study

LOS ANGELES, Dec. 12 -- Men with type 1 diabetes ( juvenile onset diabetes) may be able to grow their own insulin- producing cells from their testicular tissue, a new study suggests.

The research was conducted by Georgetown University Medical Center (GUMC), according to the American Association for the Advancement of Science (AAAS), which published the study findings on Sunday.

The research team took one gram of tissue from human testes and produced about 1 million stem cells in the laboratory. These cells showed many of the biological markers that characterize normal beta islet cells.

They then transplanted those cells into the back of immune deficient diabetic mice, and were able to decrease glucose levels in the mice for about a week, demonstrating the cells were producing enough insulin to reduce hyperglycemia.

While the effect lasted only week, newer research has shown the yield can be substantially increased, said the study's lead investigator, G. Ian Gallicano, Ph.D.

The researchers accomplished this feat without use of any of the extra genes now employed in most labs to turn adult stem cells into a tissue of choice, according to the report.

The study is a proof of principle that human spermatogonial stem cells (SSCs) extracted from testicular tissue can morph into insulin-secreting beta islet cells normally found in the pancreas, the report said.

"No stem cells, adult or embryonic, have been induced to secrete enough insulin yet to cure diabetes in humans, but we know SSCs have the potential to do what we want them to do, and we know how to improve their yield," said Gallicano, an associate professor in the Department of Cell Biology and Director of the Transgenic Core Facility at GUMC.

Given continuing progress, Gallicano said his strategy could provide a unique solution to treatment of individuals with type 1 diabetes.