May 12, 2008, 9:45 PM CT
Women who breastfeed for more than a year
Women who breast feed for longer have a smaller chance of getting rheumatoid arthritis, suggests a study published online ahead of print in the Annals of the Rheumatic Diseases.
The study also observed that taking oral contraceptives, which are suspected to protect against the disease because they contain hormones that are raised in pregnancy, did not have the same effect. Also, simply having children and not breast feeding also did not seem to be protective.
The scientists compared 136 women with rheumatoid arthritis with 544 women of a similar age without the disease. They observed that that those who had breast fed for longer were much less likely to get rheumatoid arthritis.
Women who had breastfed for 13 months or more were half as likely to get rheumatoid arthritis as those who had never breast fed. Those who had breast fed for one to 12 months were 25 per cent less likely to get the disease.
The proportion of women breast feeding for more than six months has increased dramatically over the past 30 years. The authors concluded that it was difficult to say whether there was a correlation between higher rates of breast feeding and a corresponding fall in the number of women affected by rheumatoid arthritis, but that the results of the study provided yet another reason why women should continue breast feeding.........
Posted by: Janet Read more Source
May 12, 2008, 9:43 PM CT
Physical activity prevent breast cancer
Physically active women are 25 per cent less likely to get breast cancer, but certain groups are more likely to see these benefits than others, finds a review of research published online ahead of print in the British Journal of Sports Medicine.
The type of activity undertaken, at what time in life and the womans body mass index (BMI) will determine how protective the activity is against the disease.
Lean women who play sport or undertake other physically active things in their spare time, particularly if they have been through the menopause, have the lowest risk of breast cancer.
The scientists evaluated the literature and analysed 62 studies looking at the impact of physical activity on breast cancer risk. They then examined the findings to find out how breast cancer risk appeared to be affected by type of activity, intensity of activity, when in life the activity waccording toformed and other factors.
They found the most physically active women were least likely to get breast cancer. All types of activity reduced breast cancer risk but recreational activity reduced the risk more than physical activity undertaken as part of a job or looking after the house. Moderate and vigorous activity had equal benefits.
Women who had undertaken a lot of physical activity throughout their life had the lowest risk of breast cancer, and activity performed after the menopause had a greater effect than that performed earlier in life.........
Posted by: Janet Read more Source
May 12, 2008, 9:41 PM CT
What's the difference between a human and a fruit fly?
Fruit flies are dramatically different from humans not in their number of genes, but in the number of protein interactions in their bodies, as per researchers who have developed a new way of estimating the total number of interactions between proteins in any organism.
The new research, published recently (13 May 2008) in the Proceedings of the National Academy of Sciences journal, shows that humans have approximately 10 times more protein interactions than the simple fruit fly, and 20 times as a number of as simple, single-cell yeast organisms.
This contradicts comparisons between the numbers of genes in different organisms, which yield surprising results: humans have approximately 24,000 genes, but fruit flies are not far behind, with approximately 14,000 genes.
The interaction between different proteins is behind all physiological systems in the human body. When the body digests food, responds to a change in temperature, or fights off an infection, numerous combinations of protein interactions are involved. However, until now it has been impossible to calculate the numbers of interactions that take place within different organisms.
Professor Michael Stumpf from Imperial College Londons Department of Life Sciences, one of the papers authors, explains the significance of the new study, saying:........
Posted by: Scott Read more Source
May 12, 2008, 9:34 PM CT
Seeing Alzheimer's amyloids
A-beta peptide fibril shown using electron microscopy.
Credit: Nikolaus Grigorieff, Brandeis University
In an important step toward demystifying the role protein clumps play in the development of neurodegenerative disease, scientists have created a stunning three-dimensional picture of an Alzheimers peptide aggregate using electron microscopy. The study, in this weeks issue of the Proceedings of the National Academy of Sciences, reports that scientists from Brandeis University in Waltham, Mass., and the Leibniz Institut in Jena, Gera number of, have shownfor the first timehow A-beta peptide, found in the brains of Alzheimers patients, forms a spaghetti-like protein mass called an amyloid fibril.
This study is a significant advance regarding our understanding of how these fibrils are built from the A-beta peptide (Alzheimer's peptide), said co-author Nikolaus Grigorieff, a biophysicist at Brandeis University and an investigator with the Howard Hughes Medical Institute. People have been guessing for decades what these fibrils look like, but now we have an actual 3D image.
In healthy people A-beta peptide does not aggregate, but in Alzheimers patients it clumps first and then forms long fibrils, like tentacles, in a so-called cross-beta structure. Researchers disagree whether it is the clumps that kill neurons in the brain or the fibrils. Grigorieff wants to discover which part of the amyloid structure is toxic; that would be an important step in designing drugs to prevent or treat disease.........
Posted by: Daniel Read more Source
May 11, 2008, 10:13 AM CT
Number Of Fat Cells Remains Constant In All Body Types
The radioactive carbon-14 produced by above-ground nuclear testing in the 1950s and '60s has helped scientists determine that the number of fat cells in a human's body, whether lean or obese, is established during the teenage years. Changes in fat mass in adulthood can be attributed mainly to changes in fat cell volume, not an increase in the actual number of fat cells.
These results could help scientists develop new pharmaceuticals to battle obesity as well as the accompanying diseases such as hypertension and diabetes.
A new study by Lawrence Livermore National Laboratory scientist Bruce Buchholz - along with colleagues from the Karolinska Institute in Sweden; Humboldt University Berlin, Foundation of Research and Technology in Greece; Karolinska University Hospital; and Stockholm University - applied carbon dating to DNA to discover that the number of fat cells stays constant in adulthood in lean and obese individuals, even after marked weight loss, indicating that the number of fat cells is set during childhood and adolescence.
Carbon dating is typically used in archaeology and paleontology to date the age of artifacts. However, in this application, which appeared in the May 4 early online edition of the journal, Nature, the researchers used the pulse of radiocarbon to analyze fat cell turnover in humans.........
Posted by: JoAnn Read more Source
May 11, 2008, 9:16 AM CT
Concerns over childhood and adolescent obesity
Study findings presented at the May 2008 Pediatric Academic Societies and Asian Society for Pediatric Research Joint Meeting indicate that childhood and adolescent obesity negatively impacts vascular endothelial function, which relates to cardiac health.
Obesity has been increasing rapidly in the U.S. during the past 20 years and obesity in adults has been associated with cardiovascular disease. The occurence rate of obesity in children is also increasing and a number of cardiovascular diseases that are manifested in adulthood may actually begin in childhood. It is known that healthy endothelium (a single cell layer that lines all blood vessels) is key to maintaining vascular health. Endothelial dysfunction is a primary contributor to atherosclerotic cardiovascular disease (the buildup of fatty deposits on the inside walls of arteries) in adults and is linked to increased risk of heart attacks, stroke, and congestive heart failure. Endothelial function can be measured non-invasively in children using venous occlusion plethysmography (VOP), a technique that measures responses of arm blood vessel responses to an inflatable cuff that externally halts and restarts blood flow. This method has been shown to correlate with coronary artery function in adults with heart disease.........
Posted by: JoAnn Read more Source
May 11, 2008, 9:12 AM CT
How body size is regulated?
Researchers are beginning to unravel the question why people distinctly vary in size. In cooperation with researchers of the HelmholtzZentrum München, an international genome-wide study has discovered ten new genes that influence body height and thus provides new insights into biological pathways that are important for human growth.
This meta-analysis, reported in the latest issue of Nature Genetics, is based on data from more than 26,000 study participants. It verifies two already known genes, but also discovered ten new genes. Altogether they explain a difference in body size of about 3.5 centimeters.
The analysis produced some biologically insightful findings. Several of the identified genes are targeted by the microRNA let-7, which affects the regulation of other genes. This connection was completely unknown until now. Several other SNPs may affect the structure of chromatin, the chromosome-surrounding proteins. Moreover, the results could have relevance for patients with inherited growth problems, or with problems in bone development, because some of the newly discovered genes have rare mutations, known to be linked to anomalous skeletal growth. Further functional studies are necessary to completely elucidate the biological mechanisms behind this growing list of genes correlation to height.........
Posted by: JoAnn Read more Source
May 11, 2008, 9:08 AM CT
UV lotion lights the way to cleaner facilities
A team of Canadian researchers using a lotion which glows under ultraviolet light have shown that up to a third of patient toilets are not properly cleaned. Their findings, published in BioMed Centrals journal, BMC Infectious Diseases, also show that spores from the nasty bacteria Clostridium difficile (C. difficile) linger in the loo even when it has been thoroughly wiped down.
Michelle Alfa and a team of researchers from Manitoba, Canada investigated the spread of so-called superbugs in hospitals. Hospital patients are thought to catch bugs like vancomycin resistant Enterococci (VRE), methicillin resistant Staphylococcus aureus (MRSA) and C. difficile because they are not eradicated from the hospital environment. These bugs may be transferred between patients through cross-contamination in the bathroom.
Various studies have looked at the most effective cleaning agents, but none of these studies considered whether housekeeping staff were actually cleaning the toilets properly, says Alfa. It is impossible to assess the effectiveness of any action against these bacteria unless you can be sure that cleaners comply with protocols.
Alfa's toilet inspectors smeared the UV lotion under the seats of 20 toilets and commodes being used by patients with diarrhoea at a hospital in Winnipeg. Seven of these patients had C. difficile infection, while 13 others did not. The toilets and commodes were tested every weekday for six months and checked using UV light to determine how well they had been cleaned. In addition, samples were taken from toilet surfaces to determine whether C difficile spores were present.........
Posted by: Mark Read more Source
May 11, 2008, 9:04 AM CT
Is divorce bad for the parents?
The elderly are cared for by their adult children regardless of their marital status. In a unique study funded by the Economic and Social Research Council, scientists found British adult children help their elderly parents as per current need (i.e. health) rather than past behaviour. This contrasts with other countries such as the US, where parents with a history of divorce see less of their children and receive less help from them.
So in the UK a parent that is living alone is more likely to receive help from children than parents with partners. Children also give more help as the parent ages. For every extra year of the parents age, he/she is 9% more likely to receive help from children not living at the same address. And parents with health problems are 75% more likely than those without health problems to be helped by their children. Curiously, divorced parents get more help from children than if they are widowed, but both groups receive more help than if they still have a partner. And it helps to have more children. Parents with more children receive more support; however, step children give step parents less support.
The research was carried out by a team from the Institute of Gerontology at Kings College London. They analysed data from an annual survey of over five thousand British households (British Household Panel Survey) from 1991 to 2003. They compared this information with a survey of over 3500 people at around retirement age (55-69 years) in 1988, and an Italian family survey.........
Posted by: JoAnn Read more Source
May 8, 2008, 9:13 PM CT
How slow growth as a fetus can cause diabetes as an adult
Intrauterine growth retardation (IUGR), which results in a baby having a low weight at birth, has been associated with the development of type 2 diabetes in adulthood. It has been suggested that this is because the expression of key genes is altered during fetal development and that this affects disease susceptibility during the later part of life. Evidence to support this hypothesis and indicating that the changes in gene expression might be permanent has now been provided by Rebecca Simmons and his colleagues, at the University of Pennsylvania, Philadelphia, using a rat model of IUGR.
Pervious studies using the rat model of IUGR have shown decreased fetal expression of the gene Pdx1, which is critical for the development and function of the cells that become defective in type 2 diabetes (pancreatic beta-cells), and adult onset of diabetes. In this study, expression of Pdx1 was found to be reduced in pancreatic beta-cells throughout life following IUGR. The molecular mechanisms (known as epigenetic mechanisms because they affect gene expression without altering the information in the gene) that reduced Pdx1 expression in pancreatic beta-cells were found to change during development. One mechanism was observed in the fetus, one following birth, and one after the onset of diabetes in adulthood. Of interest, the mechanisms reducing Pdx1 gene expression in the fetus and following birth could be reversed, whereas those reducing Pdx1 gene expression in the adult were irreversible. These data provide new insight into the mechanisms by which diabetes develops in adulthood following IUGR.........
Posted by: Emily Read more Source