Tuesday, February 19, 2008

A step towards three-parent babies?

Scientists at the University of Newcastle are developing a technique that they hope will enable women with a group of devastating hereditary illnesses - known as mitochondrial diseases - to have children without passing on their genetic disorders. Because the method involves sperm from one man and two eggs from different women it has been dubbed by the press as the creation of 'three-parent' embryos.
Mitochondria are tiny structures that provide cells with energy. Every cell in the body has between 1000 and 10,000 mitochondria. Whilst the vast majority of a cell's DNA is contained inside its nucleus, a handful of genes are found in the mitochondria - just 37 genes out of around 25,000 genes in total. Mutations in mitochondrial genes cause a range of disorders that affect one person in every 6,500 and include fatal liver failure, stroke-like episodes, blindness, deafness, diabetes and forms of epilepsy and muscular dystrophy. Sperm do not contribute any mitochondria to the embryo (as they are all present within the tail, which falls off after fertilisation) and, consequently, children inherit all their mitochondrial genes from their mother.
The Newcastle researchers are working on a technique that takes the DNA from the nucleus of a newly-fertilised egg, and transplants it into an egg from another woman which has had all of its nuclear DNA removed. The resulting embryo would have mitochondria from one woman, but its remaining 25,000 or so genes would come from the mother and father who provided the fertilised egg. In this way, a mother could have a child without passing on her faulty mitochondrial genes.
The work is as yet unpublished, but at a recent scientific meeting of the researchers reported successful transplants in ten embryos, which were then grown in the laboratory for five days before they were destroyed. However, all these experiments were done by exchanging DNA between two 'failed' embryos left-over from IVF, which have abnormal amounts of nuclear DNA and so are inappropriate for implantation. It is not yet known if the technique will work with healthy embryos and eggs, although experiments in mice have been successful. Team leader Professor Patrick Chinnery said: 'there are still a number of scientific issues we've got to resolve, in terms of efficiency, and in terms of whether we can do this in eggs rather than in other embryos'.

Monday, February 18, 2008

Egg-Sperm Interaction



The present era of infertility management is characterized by an increasing interest in defects of sperm-egg interactions. When the spermatozoon meets the egg, it must first react with the enveloping coat which controls sperm access to the cell surface of the oocyte. Adequate sperm motility is a major condition for penetration through the egg investments. The ability of spermatozoa to respond to physiological stimuli by a timely acrosome reaction is another necessary prerequisite for this event, as well as for sperm fusion with the oocyte.
A precise understanding in the functional competence of mammalian sperm is essential to generate clinical advances for the treatment of infertility and novel contraceptive strategies. The fundamental knowledge on the controlling parameters for spermatozoal activation process will help in the identifying the causes in fertilization failure due to male factor as well as in developing male contraceptive methodologies. The defects in the sperm-egg interaction seem to be one of the controlling mechanisms, however, none of the presently available methods for the evaluation of the fertilizing ability of sperm precisely indicates the reason for the failure or the success of sperm entry into egg. Adequate number of motile spermatozoa with normal morphology and timely occurrence of acrosome reaction are presumably the major prerequisites for the penetration through the egg investments.
Fertilization is the sum of the cellular mechanisms that pass the genome from one generation to the next and initiate development of a new organism. A typical, ovulated mammalian egg is enclosed by two layers: an outer layer of ~5000 cumulus cells and an inner, thick extracellular matrix, the zona pellucida. To reach the egg plasma membrane, sperm must penetrate both layers in steps requiring sperm motility, sperm surface enzymes, and probably sperm-secreted enzymes. Sperm also bind transiently to the egg zona pellucida and the egg plasma membrane and then fuse. Signaling in the sperm is induced by sperm adhesion to the zona pellucida, and signaling in the egg by gamete fusion. The gamete molecules and molecular interactions with essential roles in these events are gradually being discovered.

Sunday, February 17, 2008

Printed Toilet Paper Flushes Humanity Down the Tubes, Again



This toilet paper printed with manga, trivia and astronomy facts has the potential to change civilization as we know it, affecting generations to come and catapulting Humanity to the Stars. Or maybe destroy the planet. It can go either way, really. It's Japan-only for now, but we demand this ingenious way to educate millions of people while disposing off their metabolism byproducts- gets marketed worldwide at once. And yes, the porn version is probably coming sooner than later.

Saturday, February 16, 2008

Sweetner Shocker

Using an artificial, no-calorie sweetener rather than sugar may make it tougher, not easier, to lose weight, U.S. researchers said Sunday. Scientists at Purdue University in West Lafayette, Indiana, studied rats that were fed food with the artificial sweetener saccharin and rats fed food with glucose, a natural sugar. In comparison to rats given yogurt sweetened with glucose, those that ate yogurt sweetened with saccharin went on to consume more calories and put on more weight and body fat.
The researchers said sweet foods may prompt the body to get ready to take in a lot of calories, but when sweetness in the form of artificial sweeteners is not followed by a large amount of calories, the body gets confused, which may lead to eating more or expending less energy than normal. "The data clearly indicate that consuming a food sweetened with no-calorie saccharin can lead to greater body-weight gain and adiposity than would consuming the same food sweetened with high-calorie sugar," Purdue researchers Susan Swithers and Terry Davidson wrote in the journal Behavioral Neuroscience, published by the American Psychological Association. "Such an outcome may seem counterintuitive, if not an anathema, to human clinical researchers and health care practitioners who have long recommended the use of low- and no-calorie sweeteners as a means of weight control." Other artificial sweeteners such as aspartame that also taste sweet but do not lead to the delivery of calories may have similar effects, the researchers said.

"Animals may use sweet taste to predict the caloric contents of food. Eating sweet noncaloric substances may degrade this predictive relationship," the researchers wrote. "With the growing use of noncaloric sweeteners in the current food environment, millions of people are being exposed to sweet tastes that are not associated with caloric or nutritive consequences," the researchers added. The research was the latest to examine the question of whether artificial sweeteners -- used in many soft drinks and other foods — help or thwart those trying to lose weight. Various studies have offered mixed results.

The new research drew criticism from the food industry. "This study oversimplifies the causes of obesity," Beth Hubrich, a dietitian with the Calorie Control Council, an industry association representing companies that make low- and reduced-calorie foods and beverages, said in a statement. "The causes of obesity are multi-factorial. Although surveys have shown that there has been an increase in the use of 'sugar-free' foods over the years, portion sizes of foods have also increased, physical activity has decreased and overall calorie intake has increased," Hubrich added.

Any comments ye blogeurs?

Friday, February 15, 2008

Ten years' pain, 15 IVF attempts, £64,000... One Miracle

A British couple are celebrating the birth of a baby girl after ten years of trying to conceive using IVF, at an estimated cost of about £64,000. Their daughter, Olivia, was conceived on the couple's 15th attempt at IVF and was born last month.
Delina and Simon Tree, who are both 40 years old and from Sevenoaks in Kent, were told that they only had approximately a five per cent chance of success with IVF, due to the number of treatments they had previously had. Despite this, they kept on trying, and theirs is now thought to be one of the longest 'IVF marathons' to have ever taken place in the UK. According to fertility experts, most couple will either conceive on the fifth or sixth attempt or will give up trying, and seek alternatives, at about the same point.
The couple originally turned to IVF after Mrs Tree had had to have a Fallopian tube removed after a natural pregnancy was ectopic. She has since been examined by dozens of consultants across the country and none of them have been able to explain why her eggs, fertilised outside the body with her husband's sperm, had failed to develop once they had been re-implanted. Mrs Tree was encouraged by their family doctor to undergo a 15th IVF cycle last year. 'For the first four months I was terrified', she said. 'When friends congratulated me it didn't sink in. I would even go for extra private scans to make sure that the baby was OK', she added.
During the couple's extended period of treatment, which required them to remortgage their house - twice - and work lots of extra hours as overtime in order to be able to pay for it, they previously conceived, but suffered an early miscarriage, and also looked into adoption as an alternative. Delina Tree said all their efforts had been totally worthwhile: ' All that time, effort and money was definitely worth it in the end', she said, adding: 'We are so happy'.
The couple hope that 'going public' with their experiences will give encouragement to other couples undergoing IVF, particularly those who may be feeling disillusioned after a failed attempt. Each time they were unsuccessful - at a cost of about £4,000 - they felt that they were 'pouring money down the drain', said Mrs Tree. She explained that the couple had taken out bank loans, remortgaged, asked their parents for money and that she had stayed in a job she hated and that her husband, a carpenter, had 'worked evenings and weekends just so we had enough money for the IVF'.

Wednesday, February 13, 2008

Sperm Washing





If you are having difficulties becoming pregnant, you may have decided to try certain fertility treatments in order to increase your chances of conceiving. Intrauterine insemination (IUI) is often the first type of fertility treatment attempted by couples. In order to get sperm ready for the IUI procedure, it must first be washed. Sperm washing may sound strange, but it actually works to ensure that only the healthiest sperm are used during the procedure. Sperm washing can increase your chances of conception and may help you to welcome a new addition to your family. Sperm washing is a procedure used to prepare sperm for use in IUI. It allows your partner’s sperm a better chance for survival and fertilization. Sperm washing separates sperm cells from a man’s semen, helping to get rid of dead or slow-moving sperm as well as additional chemicals that may impair fertilization. Once sperm has been washed at your fertility clinic’s laboratory, it can be used during IUI to help achieve pregnancy. There are a variety of different sperm washing procedures.

Sperm must be washed in order to be used with IUI. Raw semen cannot be inserted directly into a woman’s uterus. This is because semen contains chemicals called prostaglandins. Prostaglandins cause muscular contractions and are responsible for cramps during menstruation and pregnancy. If raw semen is inserted directly into your uterus, rather than going through the cervix first, it could cause severe pain and cramping. It could also cause your uterus to collapse, causing severe complications.
Sperm is also washed in order to increase your chances of becoming pregnant. Sperm washing can remove dead sperm and those sperm with poor motility. This leaves behind sperm that can swim faster and that are more likely to fertilize your egg. Sperm washing can also get rid of the white blood cells, mucous and seminal fluid surrounding the sperm, which can also interfere with fertility.

Anyone who pursues IUI will receive the sperm washing procedure. However, the procedure can also benefit others, especially those with:

-unexplained infertility
-male-factor infertility
-women with endometriosis
-men with antisperm antibodies


The sperm wash procedure is actually relatively easy to prepare for. Your semen will be collected after you masturbate, or from a sample taken during surgical sperm retrieval. It is important to refrain from sexual intercourse for two days before your sperm is collected. However, do not go more than five days without intercourse. Certain antibiotics may also affect the quality of your sperm, so speak with your fertility physician if you are taking any medications.

There are three commonly-used sperm washing techniques:

Simple Sperm Wash
The simple sperm wash technique is the most basic way of washing and preparing sperm for IUI. Semen is diluted in a test tube with a special solution of antibiotics and protein supplements. It is then placed in a centrifuge, a machine that spins around at extremely high speeds. As the sperm mixture is spun, sperm cells fall to the bottom of the test tube, producing a mass of dense, highly active sperm. These sperm can then be removed from the test tube and used in IUI. A simple sperm wash takes about 20 to 40 minutes.

Density Gradient Sperm Wash
The density gradient sperm wash is one of the most popular sperm washing methods. This is because it also works to separate dead sperm cells, white blood cells, and other waste products from the sperm. A test tube is filled with multiple layers of liquids of different densities. Semen is then placed on the top layer of liquid and the test tube is spun in a centrifuge. After it is spun, active, healthy sperm will make their way to the very bottom layer of liquid in the test tube, while debris and dead sperm will get caught in the top two layers. These layers can be siphoned off in order to remove the active sperm from the test tube. This sperm is then used in the IUI procedure. Density gradient sperm washes take approximately 60 minutes.

Swim Up Technique
The swim up technique is rapidly becoming more and more popular throughout Indian fertility clinics. This technique revolves around the fact that sperm need to swim forwards and up in order to reach the uterus. Only the most powerful sperm will be able to do this. In order to retrieve this powerful sperm, semen is placed in a culture dish with a layer of media culture. Sperm are attracted to this culture, and will swim up to it. As the sperm swim up to the culture, they are collected. This technique takes about an hour in order to harvest enough sperm for use in IUI.

Success Rates
Success rates do increase when sperm washing is used with IUI. Because sperm washing ensures that only the most healthy and active sperm are used for fertilization, there is an increased chance that you will become pregnant when using washed sperm. However, success rates do depend on your partner’s overall sperm count. Typically, the lowest sperm count to be used with sperm washing is one million, however, success rates are significantly lower if your sperm count falls beneath five to ten million. The best sperm counts for use with sperm washing are those between 20 and 30 million.

Cost of the Procedure
The cost of sperm washing in itself is relatively low. A basic sperm wash typically costs only Rs.3000 or so. If you opt for one of the more advanced forms of sperm washing, it could cost you up to Rs.10000. However, sperm washing is only of use when combined with other fertility treatment procedures. One session of natural IUI typically costs under Rs.3000 while IUI with the use of fertility drugs and monitoring can cost anywhere between Rs 8000 and Rs 10,000.