Tuesday, March 18, 2008

Viagra could harm sperm and reduce fertility

Two new studies have identified factors that could be causing a decline in male fertility. Research published in the journal Fertility and Sterility on the anti-impotence drug Viagra concluded that men taking the drug could be damaging their sperm and lowering their ability to conceive. Another study, published in the environmental journal the Ends Report, suggests that pollution from chemicals such as dioxin can lower a man's sperm count.
The first study, led by Dr David Glenn at Queen's University Belfast, , treated sperm in vitro with Viagra, and found treated sperm to be more active than untreated sperm, but also that the 'acrosome', which produces enzymes that help the sperm penetrate the egg, was damaged by the drug. Tests in mice showed that sperm treated with Viagra produced 40 per cent
less embryos than untreated. Dr Glenn is concerned that the drug is being prescribed to couples seeking help for fertility problems, and says that 'giving male partners something that could make the problem worse is scarcely the right approach'. He has also raised issues with younger males using the drug recreationally, who may be harming their chances of starting
a family in the future. The second study identified another factor thought to influence male fertility rates: pollution from chemicals such as dioxin, released through industrial processes and found in the atmosphere. A chemical explosion in
Italy in 1976 exposed people to a cloud of highly toxic dioxin. A study 22 years later of male volunteers who were exposed found that men who were aged under nine at the time of the explosion had 43 per cent lower sperm counts than a control group. Men who were aged between ten and 17 when exposed, however, had sperm counts 62 per cent higher, and men who were over 17 were unaffected. The findings suggest that dioxin is a potential factor responsible for falling sperm counts, and also puts a question mark over other industrial chemicals.
Endocrine-disrupting chemicals are also thought to be affecting fertility rates. Three such chemicals have been investigated by scientists at the National Food Institute, Technical University of Denmark. When the chemicals were administered separately, they were harmless. Concurrent exposure, however, resulted in malformed sexual organs in the fetuses, showing potential cocktail effects of chemicals should be taken into account when investigating their effects on fertility rates. In Denmark, just under five per cent of boys are born with a certain malformation of their sexual organs. Meanwhile, new hope was given to infertile couples in Australia, where Menevit, the 'first ever drug to for male infertility', has been developed. It contains antioxidants and works by acting on free radicals that fragment sperm, the main cause of infertility. In a preliminary study of 60 infertile men, the rate of pregnancy was increased significantly, but larger clinical trials are required before the drug can be merited.

Monday, March 17, 2008

Defective Sperm Cells Inside The Body Tagged By Quality Control Mechanism

Defective sperm cells do not pass through the body unnoticed. A new University of Missouri study provides evidence that the body recognizes and tags defective sperm cells while they undergo maturation in the epididymis, a sperm storage gland attached to the testis. According to researchers, only the best sperm that have the highest chance of succeeding in fertilization will survive the production process without a "tag."

A small protein called ubiquitin marks abnormal sperm cells, including cells that have two heads, two tails or are otherwise misshaped. This "recycling tag" on the sperm cell tells the body which cells need to be broken back down into amino acids. This provides evidence that there is an active removal process or marking of defective sperm during the epididymal passage.

"Fertilization is, in a way, a numbers game," said Peter Sutovsky, associate professor of animal sciences, clinical obstetrics and gynecology in the MU College of Agriculture, Food and Natural Resources. "You need a certain number of normal sperm cells to reach the egg. If too many are tagged with ubiquitin, there may be not enough to fertilize an egg."

This study suggests that the male reproductive system must be able to evaluate and control the quality of the sperm to insure an optimal chance of fertilization. High levels of ubiquitin in the sperm can indicate low-sperm count or infertility. This process of quality control has been found in both humans and other mammals including bulls, boars and rats.

"In many cases, the cells that are tagged with ubiquitin are obviously abnormal with two tails or two heads, but many of them look like they don't have defects," Sutovsky said. "Oftentimes, these cells may look normal but lack proteins that are important to fertility."

Once sperm cells are tagged as defective, it is unlikely that the process can be reversed. Sutovsky stresses the importance of a healthy lifestyle to reduce the likelihood of abnormal sperm cells. He suggests avoiding exposure to toxic chemicals, abstaining from smoking and maintaining a healthy diet. He suggests people who work with toxins on a daily basis should minimize their exposure by wearing protective clothing and respirators.

Sunday, March 16, 2008

The Cardiac Surgeon & The Mechanic

A mechanic was removing the cylinder heads from the motor of a car when he spotted the famous heart surgeon in his shop, who was standing off to the side, waiting for the service manager to come to take a look at his car. The mechanic shouted across the garage,"Hello Doctor!! Please come over here for a minute." The famous surgeon, a bit surprised, walked over to
the mechanic.

The mechanic straightened up, wiped his hands on a rag and asked argumentatively, "So doctor, look at this. I also open hearts, take valves out, grind 'em, put in new parts, and when I finish this will work as a new one. So how come you get the big money, when you and me is doing basically the same work? "


The doctor leaned over and whispered to the mechanic.....

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He said: "Try to do it when the engine is running".

Foot-in-the-mouth Disease

Thursday, March 13, 2008

Happiness isn't what you are, it's who you are

British and Australian scientists have found that a person's genes can predispose them towards happiness. Reporting in the journal Psychological Science, the researchers found that genes account for 50 per cent of the factors contributing to an individual's satisfaction with life, with external influences such as health, wealth, relationships and career accounting for the other 50 per cent.
The team, from the University of Edinburgh and the Queensland Institute for Medical Research, conducted a study on more than 900 pairs of twins aged from 25 to 75 years old. Happiness was assessed through a questionnaire designed to determine certain personality traits such as a tendency not to worry excessively, or being sociable or conscientious. Previous research has indicated that these traits contribute towards an overall sense of contentment and well-being. By comparing the results from identical twins (who have exactly the same genes) and non-identical, fraternal twins (who share on average 50 per cent of their genes), the researchers were able to estimate how much genes influence certain characteristics compared to nurture and up-bringing. What they found 'was that the identical twins in a family were very similar in personality and in well-being and, by contrast, the fraternal twins were only around half as similar', said Dr Tim Bates, one of the Edinburgh researchers. He concluded: 'that strongly implicates genes'.
Importantly, the study found that with identical twins, the siblings' similar outlook on life did not depend on their current life circumstances. So even if one twin could be perceived as being more successful than the other, or as living a more desirable lifestyle, they would both nonetheless feel similarly contented with their lot. Their shared genetic make-up inclines them towards similar levels of satisfaction, regardless of differing life situations. Dr Bates explained: 'it is a genetic link to
personality, rather than a particular happiness gene...which is partly responsible for our levels of happiness'. The researchers believe that certain genetically-defined characteristics may make a person more or less able to take stressful or difficult times in their stride. Those genetically predisposed towards contentment may find it easier to get through these times and find future happiness. Dr Alexander Weiss, also of the Edinburgh team, summarised: 'although happiness is subject to a wide range of external influences we have found that there is a heritable component of happiness which can be entirely explained by the genetic architecture of personality'. Although these findings are important, other psychologists have emphasised that it does not mean a person's state of mind is set in stone by their genes. Dr Carol Craig of the Centre for Confidence and Wellbeing in
Glasgow told The Scotsman newspaper: 'genes may be significant, but there are things everyone can do to improve their happiness'.