Scientific developments
- AIDS protein hope
- Amino acid implicated in stroke, Alzheimer's
- Breast cancer: critical gene identified
- Cancer protein unravelled by Australian researchers
- Hepatitis C sufferers to benefit from new drug treatment
- Malaria genome sequenced
- Ovarian cancer test
- Parkinson's disease treatment?
- Stem cells can boost motor skills
AIDS protein hope
27 September - US scientists have identified a protein which enables HIV positive patients to remain healthy for many years after being infected with the AIDS virus. For some time researchers have been interested in the approximately 5% of people infected with HIV who live for over 10 years with no damage to their immune system. They have been searching for the factors present in these patients which help them survive. This latest finding, published in Science magazine, identifies three alpha-defensin proteins. These proteins are usually used by the body to help kill bacteria. Now, researchers hope they will lead to new treatments for the disease. However, other researchers are sceptical about the result, claiming to have already ruled out a role for defensins as protectors from AIDS progression. Additionally, defensins are hard to manufacture, suggesting it will be some time before they are used in medication.
[Source: New York Times - Andrew Pollack]
Amino acid implicated in stroke, Alzheimer's
3 October - A new risk factor has been suggested for diseases such as stroke and Alzheimer's. The factor is the amino acid homocysteine, which if present in high levels, could substantially increase the risk for these diseases. In this new research, homocysteine levels were measured in people who had either experienced a stroke, developed Alzheimer's or had vascular dementia. When compared with healthy older people, those who had had a stroke were more than five times as likely to have elevated levels of homocysteine. Additionally, elevated homocysteine raised the risk of Alzheimer's threefold. Although the research does not prove a direct link between the amino acid and the disease risk, with other risk factors also being relevant, evidence is significant enough to encourage people to take vitamins such as vitam B and folate to control their homocysteine levels. The researchers are now planning placebo-controlled trials to investigate the impact of taking vitamin supplements.
[Source: Reuters Health - Merritt McKinney]
Breast cancer: critical gene identified
8 October - US researchers have identified a gene which is inactivated or completely missing in 60% of non-hereditary (sporadic) breast cancers and 50% of lung cancers. The gene, DBC2, is apparently critical for preventing the onset of cancer. In finding the gene, researchers compared the genetic makeup of breast cancer and normal cells. Frequent differences were noted in one area on chromosome eight, which was then narrowed down to the DBC2 gene deletion. Compared with a 100% expression of the gene in healthy cells, only 19% of breast cancer cells were shown to express the gene. Further, forcing cancer cells to express the gene inhibited the cancer's growth. Although the gene's usual role has yet to be elucidated, the finding suggests that cancers may be treated by "switching on" the gene if it is found to be silenced.
[Source: New Scientist - Emma Young ]
Cancer protein unravelled by Australian researchers
26 September - Australian researchers have deduced the three-dimensional structure of a significant protein found on the surface of cancer cells, a finding that could lead to new cancer-fighting drugs. Researchers at the Ludwig Institute, the Walter and Eliza Hall Institute and CSIRO Health Sciences and Nutrition (all members of the CRC for Cellular Growth Factors) collaborated to investigate the structure of the epidermal growth factor receptor, which was discovered 20 years ago. Their findings, published in the prestigious journal Cell , centre around how the receptor recognises the epidermal growth factor protein, and how it transmits the signal to cancer cells to enable them to grow. The researchers hope to discover how to prevent the receptor from recognising the protein, which in turn will stop cancer cells growing. Patient trials of a candidate drug are slated for 2004.
[Source: ABC Science Online - Danny Kingsley]
Hepatitis C sufferers to benefit from new drug treatment
25 September - An experimental form of the drug interferon has been shown to be more effective at preventing the progression of hepatitis C than more conventional treatments. The finding, published in the New England Journal of Medicine , could improve the treatment of over 170m people worldwide who suffer with the disease. If left untreated, the disease can significantly damage vital organs such as the liver and can even cause death. In a trial of the long-acting form of the drug, peginterferon alpha-2a plus in conjunction with the anti-viral ribavirin, 56% of participants showed no trace of hepatitis C in their blood 24 weeks after receiving their final dose. The success rate was slightly lower in patients who received the standard form. Some of the side-effects experienced with the traditional form of Interferon were also substantially lessened. The long-acting form of the drug, marketed under the brand-name Pegasys, was approved for sale in Europe in June this year. Hoffman-LaRoche, the drug's manufacturer, hope to receive US FDA approval by December.
[Source: Reuters - Gene Emery]
Malaria genome sequenced
2 October - A worldwide collaboration of researchers has sequenced the genetic code of the parasite causing the most deadly form of malaria. The disease, which kills one child every 20 seconds, is caused by the parasite Plasmodium falciparum. Hailed as a significant advance in the fight against the disease, the sequence will be used to investigate new targets for drugs and vaccines. The genome, published in Nature, was announced in conjunction with the genetic map of the mosquito that transmits the parasite to humans. This latter sequence was published in Science .
The malaria genome was shown to consist of 14 chromosomes and 5,279 genes. Yet although relatively small, the genome was challenging to sequence as much of its DNA is unstable and would break apart as researchers were investigating it. The function of around 60% of the genes is known, and further knowledge is expected to arise about the parasite's metabolism and how it becomes resistant to drugs.
[Source: Reuters - Patricia Reaney]
Ovarian cancer test
26 September - Researchers at Melbourne's Prince Henry Institute of Medical Research, in conjunction with Monash University's Department of Obstetrics and Gynaecology, have developed a new diagnostic tool for ovarian cancer. The tool measures inhibin, a hormone normally involved in regulating fertility, which is produced by some ovarian cancers. Measuring the levels of inhibin in a woman's bloodstream could therefore indicate the presence of ovarian cancer. Additionally, the researchers have discovered that inhibin was able to detect the majority of ovarian cancers when measured with another ovarian cancer marker, CA125. An improved form of the inhibin assay is now being developed by a diagnostic company for clinical use.
[Source: Prince Henry's Institute Research News]
Parkinson's disease treatment?
27 September - New research with mice indicates that two experimental drugs, ifithrin-alpha (PFT) and Z-1-117, may be able to prevent the kinds of brain damage and motor dysfunction typically associated with Parkinson's disease in humans. The drugs appear to protect dopamine-producing nerve cells from damage, which could slow or even halt the progression of the disease. Dopamine is an essential chemical in the brain to prevent the onset of Parkinson's.
In the study, nerve cells in mice treated with the two drugs were more resistant to being killed by environmental toxins and pesticides. Such toxins are suspected as being involved in the development of Parkinson's in humans. The drugs were also useful in preserving motor function in mice exposed to such toxins. Investigators suspect the drugs work by blocking the action of the p53 protein, which is thought to promote the death of nerve cells. In understanding the pathway by which p53 kills nerve cells, researchers also hope to investigate the causes of other neurological diseases. The researchers report that although translating drug studies in animals to humans is sometimes difficult, the overwhelming response and good tolerance observed in animals is encouraging that a similar response will be seen in humans.
[Source: ScienceDaily]
Stem cells can boost motor skills
3 October - New research in mice indicates that stem cells could be used to treat brain injury. US researchers have shown that when mice have neural stem cells injected into their brains shortly after an injury, motor skills significantly improved. As there is currently no treatment for acquired brain injury in humans, the results of the study are significant. After the cells were injected, it was shown that they could migrate towards the damaged area of the brain and differentiate to replace the damaged cells. However, cognitive and mental skills of the injured mice did not improve. The researchers now plan to observe the mice over a longer period of time to examine the effects of the treatment. They also plan to investigate how long after injury a treatment can be administered and still be effective.
[Source: Reuters Health - Merritt McKinney]
