Wednesday, September 12, 2007

MAVERICK GENOME SCIENTIST UNVEILS HIS GENETIC CODE


The scientist who lead the private effort to sequence the human genome has revealed his own complete genetic make-up. The race to decode the human genome may not be entirely over: the loser has come up with a new approach that may let him prevail in the end. In 2003, a US government-financed consortium of academic centers announced it had completed the human genome, fending off a determined challenge from the biologist J. Craig Venter. The consortium’s genome comprised just half the DNA contained in a normal cell, and the DNA used in the project came from a group of people from different racial and ethnic backgrounds. But the loser in the race, Dr. Venter, could still have the last word. In a paper published recently, his research team is announcing that it has decoded a new version of the human genome that some experts believe may be better than the consortium’s. Called a full, or diploid genome, it consists of the DNA in both sets of chromosomes, one from each parent, and it is the normal genome possessed by almost all the body’s cells. And the genome the team has decoded belongs to just one person: Dr. Venter.
Dr. Venter’s race with the consortium began in 1998 when he spotted a quicker method of decoding the human genome. He tried to wrest this rich scientific prize from his academic rivals by co-founding a genome-decoding company called Celera. By June 2000, the two sides were neck and neck preparing a draft sequence of the genome. But in January 2002, Dr. Venter was abruptly fired as president of Celera. The consortium went on to claim victory when it announced its completion of the genome the next year. But the consortium’s genome, though immensely useful to biologists, was full of gaps and only complete in the sense that it was the best that could be done with existing technology. Dr. Venter has spent the last five years and an extra $10 million of his institute’s money in improving the draft genome he prepared at Celera. That genome was based mostly on his own DNA, and the new diploid version is entirely so. His critics may accuse him of an egocentricity of considerable dimension, but by analyzing his own genome he has sidestepped the problems of privacy and consent that could have arisen with other people’s DNA when he made the whole sequence publicly available, as he is doing now.
Like James Watson, the co-discoverer of DNA, whose genome is also being decoded, Dr. Venter believes strongly in making individual DNA sequences public to advance knowledge and hasten the era of personalized genomic medicine.
The unveiling of J. Craig Venter's genome in the open access journal PloS Biology marks the first time that the complete DNA sequence of an individual has been published. In 2001, Venter's company Celera published a version of the human genome that was based on information from himself and four other individuals. At the same time, the publicly-funded Human Genome Project consortium released a consensus human genome, based on DNA samples from over 100 people.
The latest study shows that the amount of genetic variation between individuals is 5-7 times greater than previously suspected. In addition to the expected 3.2 million single DNA 'letter' changes known as SNPs, Venter's genome has nearly a million other variations, which involve small sections of missing, duplicated or 'flipped around' DNA. 'This is the first time that anyone has had an accurate representation of how much variation there is in a human genome', said co-author Stephen W. Scherer of Toronto University.
Commenting on the findings, Venter said that: 'each time we peer deeper into the human genome we uncover more valuable insight into our intricate biology', adding that 'only with additional sequencing of more individual
genomes will we garner a full understanding of how our genes influence our lives'. He also revealed that the results show he has a moderate risk of developing Alzheimer's disease, saying 'there are two groups of people out there, the half that really want to know about themselves and the half that's afraid to know because of all this genetic deterministic nonsense', adding 'knowing what is there will do nothing to change what is already going on in my body'.
The new genome sequence, dubbed HuRef, was pieced together using the 'whole genome shotgun' method previously used by Celera. However, several organisations are now working on faster, cheaper methods that will eventually enable the genome of many more people to be sequenced. DNA pioneer James Watson is the only other person currently having his genome decoded.

Tuesday, September 11, 2007

Believe It Or Not

It is little known that one Okhil Chandra Sen wrote this letter to the Sahibganj divisional railway office in 1909. It is on display at the Railway Museum in New Delhi. It was also reproduced under the caption "Travelers' Tales" in the Far Eastern Economic Review

Okhil Babu's letter to the Railway Department :

"I am arrive by passenger train Ahmedpur station and my belly is too much swelling with jackfruit. I am therefore went to privy. Just I doing the nuisance that guard making whistle blow for train to go off and I am running with 'lotah' in one hand and 'dhoti' in the next when I am fall over and expose all my shockings to man and female women on plateform. It is too much shame shame for me. Then I am got leaved at Ahmedpur station.

This too much bad, if passenger go to make dung that dam guard not wait train five minutes for him. I am therefore pray your honour to make big fine on that guard for public sake. Otherwise I am making big report to papers."

Any guesses why this letter was of historic value?

It apparently led to the introduction of toilets on trains.

Monday, September 10, 2007

Its All About Efficiency

Last week, we took some friends out to a new restaurant, and noticed that the waiter who took our order carried a spoon in his shirt pocket.

It seemed a little strange.

When the busboy brought our water and utensils, I noticed he also had a spoon in his shirt pocket. Then I looked around saw that all the staff had spoons in their pockets.

When the waiter came back to serve our soup, I asked, "Why the spoon?"

He explained: "The restaurant's owners hired Andersen Consulting to revamp all our processes. After several months of analysis, they concluded that the spoon was the most frequently dropped utensil. It represents a drop frequency of approximately 3 spoons per table per hour. If our personnel is better prepared, we can reduce the number of trips back to the kitchen and save 15 man-hours per shift."

As luck would have it, I dropped my spoon and he was able to replace it with his spare.

"I'll get another spoon next time I go to the kitchen instead of making an extra trip to get it right now."

I was impressed. I also noticed that there was a string hanging out of the waiter's fly. Looking round, I noticed that all the waiters had the same string hanging from their flies.

So before he walked off, I asked the waiter, "Excuse me, but can you tell me why you have that string right there?"

"Oh, certainly!" Then he lowered his voice. "Not everyone is so observant. That consulting firm I mentioned also found out that we can save time in the restroom. By tying this string to the tip of you-know-what, we can pull it out without touching it and eliminate the need to wash our hands, shortening the time spent in the restroom by 76.39 percent."

WOW!

I asked, "After you get it out, how do you put it back?"

"Well," he whispered, "I don't know about the others, but I use the spoon."

Sunday, September 9, 2007

Did These Subjects Survive?

Its a lazy Sunday. Just got up after a long long snooze. Thought would put up some cerebral photographs. These were forwarded to me with a caption saying: Their Last Photos.










Friday, September 7, 2007

God


Hi Friends,
Going away from Medicine to faith today, the following series of pictures was one of the best e-mail forwards I have received in my life!
God Bless

Thursday, September 6, 2007

The Viagra Alarm

Viagra, the 'wonder-drug' promoted for its ability to relieve impotence in men, may have some unwanted side-effects. Research presented recently in Cheltenham, UK, at the annual meeting of the British Fertility Society, suggests that men who are taking Viagra when trying to start a family may actually be decreasing their ability to father a child. However, Viagra manufacturers Pfizer deny that the drug causes fertility problems.
Viagra was designed to enable an increase of blood flow to the penis to overcome impotence problems. However, since its release it has increasingly been used 'recreationally', and is also used by fertility clinics in order to aid patients' semen production. Viagra is what is known as a 'phosphodiesterase inhibitor', a type of chemical known to affect sperm function, so the study looked at what effect the drug has on sperm. The researchers discovered that using Viagra speeds up chemical changes within sperm, rendering them infertile by the time they reach an egg. This chemical change, known as the acrosome reaction, normally only occurs when a sperm reaches an egg, and is when sperm release enzymes that break down the outer layer of the egg allowing the sperm head to penetrate it more easily. However, if the acrosome reaction occurs too early, the sperm become ineffective and unable to enter the egg, as they have no digestive enzymes left.
Scientists from the School of Medicine, Obstetrics and Gynaecology at Queen's University, Belfast, took 45 semen samples and split them into two groups. Half of the samples were treated with Viagra, while the other half was used as control. The research team found that while Viagra increased sperm motility, up to 79 per cent more sperm in the Viagra-treated samples had clearly undergone premature acrosome reactions. These findings lead the researchers to say they had 'significant concerns for Viagra use in assisted reproduction'. They added that the findings echo previous studies in mice that showed that the presence of Viagra meant that fewer eggs would be fertilised and fewer resulting embryos developed normally.
Dr Sheena Lewis, a member of the team, said that their 'message is that caution should be taken when using recreational drugs if you are hoping to start a family'. But a representative of the European Society for Sexual Medicine, Dr John Dean, said it was important that the study wasn't reported in an alarmist fashion, adding that sperm is highly sensitive in laboratory conditions. 'Childless couples - and the general population - should be aware that in the five years that Viagra has been around no overall detrimental effect on fertility has been observed', he said.
However, Pfizer says that there has been no evidence of Viagra affecting fertility following its use by 23 million men over six years. 'It's one study and it was in a test tube basically, not in real people', said spokesman David Watts.