The Malaysian Insider :: Features
The Malaysian Insider :: Features |
| Experts grow mouse sperm to help with human infertility Posted: 05 Aug 2011 08:06 AM PDT  Baby mice born from sperm produced from stem cells are seen in this handout photo taken by Kyoto University professor Michinori Saito on November 8, 2010, and released to Reuters on August 5, 2011. — Reuters/Michinori Saitou-Kyoto University pic The finding, published in the journal Cell, marks a step forward for using stem cells for regenerative medicine. Stem cells are the body's master cells and source of all cells and tissues. Because they can grow into different types of cells and multiply, experts hope to harness them to treat diseases and disorders, including cancer and diabetes. Scientists at Kyoto University removed stem cells from mouse embryos and managed to coax them into a type of precursor cell known to grow into either mouse eggs or sperm. They then transplanted these cells into the testes of infertile male mice — which apparently went on to produce healthy sperm. "The sperm were removed directly from the testes and fertilized with eggs (on laboratory dishes)," said lead author Mitinori Saitou, a professor at Kyoto University's department of anatomy and cell biology. "After insemination, we made two set of embryos and these were transferred into the uterus of the foster mother and they derived healthy mice (that went on to reproduce normally)." Possible to grow human sperm The experiment showed scientists how they can prepare precursor cells to eventually grow into sperm or egg. "We have huge materials to work with now and . . . we can accelerate our study into the cause of human infertility," Saitou told Reuters by telephone. Saitou's team believes it may be possible to use adult human stem cells to grow human sperm. "We can possibly use this knowledge to induce human primordial germ cells (cells that grow into eggs or sperm)," he said. More work was needed, he said, because of the gulf between animal and human research. For the moment, the team was trying to repeat their feat by producing mouse eggs using stem cells, he said. — Reuters Full Feed Generated by Get Full RSS, sponsored by Used Car Search. |
| Experts study what parasites eat to find ways to kill them Posted: 05 Aug 2011 08:00 AM PDT HONG KONG, Aug 5 — Researchers in Australia are working on a technique that will allow them to starve to death parasites that are proving harder to destroy using existing drugs. The parasite they used in the study was the leishmania, which is transmitted by the bite of the phlebotomine sandfly. After a period of incubation, the parasite causes huge skin sores, fever and anaemia, and damages the spleen and liver. It affects 12 million people worldwide and has become more resistant to current drugs. The scientists exposed the parasite to a large variety of food sources. Using highly sensitive equipment, they tracked how these nutrients were broken down and absorbed into the bodies of the parasites. "Using this technique we found that Leishmania parasites are very dependent on the use of sugars for energy and growth," wrote lead author Malcolm McConville, a biochemistry and molecular biology professor at the University of Melbourne. "This was surprising as previous studies suggested that these parasites may be able to use a range of other nutrients for growth (such as amino acids and fats). "They are therefore far more picky than we thought and therefore more vulnerable to therapeutic attack," he wrote in reply to questions from Reuters. The team is hoping to use this food source as a way in to attack the parasite, which blights much of the Americas, Middle East and parts of Asia. "We are interested in seeing whether we can develop new drugs that inhibit parasite sugar metabolism. These drugs would not only prevent parasites from growing and infecting new tissues, but would also make them vulnerable to host immune response," McConville added. "The latter effect is important as Leishmania parasites can often induce a long-term chronic infection that is very difficult to clear with current drugs. There is therefore a need to develop new drugs." By observing how pathogens behave and thrive, scientists can explore ways to disrupt these processes to kill them. For example, there are certain anti-flu drugs to block viruses from entering and infecting human cells, and other drugs to stop newly-replicated flu viruses being released from infected cells. In this experiment, McConville and colleagues observed what parasites ate, so they could seek ways to kill them by starving them of the very nutrients they need. "It is directly applicable to looking at metabolism in other pathogens. For example, we are currently using it to investigate metabolism of the malarial parasite," McConville said. The study was published in the current issue of the international Journal of Biological Chemistry. — Reuters Full Feed Generated by Get Full RSS, sponsored by Used Car Search. |
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