Wednesday, November 23, 2011
Saturday, November 12, 2011
Unlike women -- who have all the eggs they will ever have when they’re born -- men produce sperm all day long. Sperm takes about two to three months to fully mature, so a guy’s behaviour during the past 90 days will affect the baby he makes today, or whether he can make one at all, said Dr. Sijo Parekattil, director of urology at Winter Haven Hospital, where he specializes in male infertility.
Although society tends to focus on women when couples can’t conceive, about half the time it’s the guy’s fault, said Parekattil, who will be among several infertility and adoption experts speaking Saturday at a free conference in Lake Mary, Fla.
Among the more common sperm-killing behaviours guys engage in are keeping cellphones in pants pockets, and working with laptops on their laps, which raises sperm temperature.
Other behaviours not conducive to fatherhood are smoking; excessive drinking; frequenting saunas and hot tubs; wearing tight underwear; using recreational drugs, including marijuana; taking male supplements; and getting sick. Studies show that such behaviours can reduce sperm quality and quantity.
Ashok Agarwal, director of the Center for Reproductive Medicine at the Cleveland Clinic, has conducted several studies on the effects of cellphone radiation on sperm. In one lab study, he found that the viability of sperm exposed to cellphone radiation for one hour dropped by 11 per cent compared with control samples.
His research also found that sperm count, motility and viability dropped more as cellphone exposure went up.
"Cellphones emit radiation, which can potentially harm the sperm in men who carry their phones in their pockets or on their belts," Agarwal said. "We believe these harmful effects are due to the proximity of the phones to the groin area."
A bout with the flu can lower sperm count, too, which is why experts recommend that men trying to have children get flu shots. Chronic diseases, such as high blood pressure and diabetes, also take their toll. Obesity can foster low sperm counts because excess fat causes men to produce more female hormones, Parekattil said.
When men take male supplements, including anabolic steroids, their bodies think they’re making too much testosterone and shut down the testicles, which actually atrophy, Parekattil said. Once guys stop taking supplements, sperm production can take a year to resume.
"A man’s lifestyle can impact the DNA organization inside the sperm and the surface properties of the sperm, which are critical for penetrating the egg, fertilizing it and helping the embryo get to full term," said Dr. Michael Witt, a urologist and male-fertility specialist who divides his time between Winter Park, Fla., and Atlanta.
Avoiding these sperm-unfriendly behaviours and conditions are sometimes all men need to do to give their sperm a boost, Witt said.
Besides having a better understanding of how lifestyle and anatomical stresses can affect sperm, men trying to become dads also benefit from another advance in male infertility: in-home sperm-test kits.
Although the home tests aren’t as sensitive as those in the urologist’s office, they’re a lot more convenient and less embarrassing than giving a sample at the doctor’s office.
A normal sperm count is about 40 million motile sperm per ejaculation, according to the World Health Organization. Most men produce that well into their 70s. However, of those men who have problems with infertility, about 10 per cent to 15 per cent make no sperm, and an additional 30 per cent have low sperm.
Among all men, about one in seven has a varicocele, in which excess blood vessels impair the count and quality of sperm, Witt said. Surgery to remove the veins often restores fertility.
Like 15 per cent of American couples, Clay and Wendi Harris of Orlando, Fla., couldn’t have a baby, despite trying for five years.
"We were tested seven ways to Sunday" to look for the cause, Clay Harris said.
After five failed rounds of in vitro fertilization, they had just about given up. Then tests showed that Harris, 38, had a sperm count in "the midrange." However, Witt reviewed Harris’ sample and thought the sperm quality would improve if he had varicocele surgery.
In November 2010, Harris had the surgery, and afterward, "my sperm count went through the roof. It skyrocketed to 90 million."
Now, the Harrises are expecting a baby boy in early February.
"When we go for our weekly ultrasound," said Clay Harris, "we just stare at the baby on the monitor and hold hands."
SOURCE: VANCOUVER SUN
Friday, August 26, 2011
FOR years, scientists thought they understood the skeleton. It serves as structural support for the body. It stores calcium and phosphate. It contributes to blood-cell development. And it serves, indispensably, as the creepy mascot of horror movies.
But as it turns out, there might be still more to bone.
A few years ago, researchers at Columbia University Medical Centre discovered, to everyone's surprise, that the skeleton seems to help regulate blood sugar. Now the team, led by a geneticist and endocrinologist at the university, Dr Gerard Karsenty, has found that bone might also play an unexpected role in reproduction. If the work pans out, it might help to explain some cases of low fertility in men.
''It's definitely an attention-grabber,'' says Dr William Crowley, of Harvard Medical School, who was not part of the research.
It is well known that the hormones oestrogen and testosterone, produced in the ovaries and testes, help to regulate bone growth. When women reach menopause, oestrogen levels decrease along with bone mass, putting them at increased risk of osteoporosis. As men age, their testosterone and oestrogen levels also decline. Men lose bone but much more slowly than women do. ''We thought that if the sex organs talk to the skeleton, then the skeleton should talk back to the sex organs,'' Karsenty says.
And, apparently, it does.
Early this year, Karsenty's team published a study demonstrating that in mice a protein called osteocalcin, which is produced by bone-forming cells called osteoblasts, binds to a specific receptor on cells of the testes. Male mice that were unable to make osteocalcin (due to genetic manipulation) produced less testosterone and were less fertile. When they mated, they had fewer and smaller offspring.
Fertility in female mice, on the other hand, was not affected by osteocalcin. Cells in their ovaries lacked the receptors to which the bone hormone binds. ''We were surprised by that,'' Karsenty says. ''We thought we'd find a hormone that regulated fertility in both sexes.'' Another compound, as yet unknown, might play the analogous role in females. Human testicular cells also have receptors for the hormone osteocalcin, Karsenty has found.
''I don't know of any hormone that functions in mice but not to some extent in humans,'' says a researcher at Maryland's Johns Hopkins University, Thomas Clemens. Still, the magnitude of the effect might not be the same as in mice.
The main hormone that stimulates testosterone production, in mice and men, is luteinizing, a protein made in the brain. Luteinizing hormone is ''the on-off switch'' for testosterone, Crowley says. Osteocalcin, on the other hand, looks more like a ''dimmer switch'' that modulates the process.
The question is, is it a critical mechanism or a back-up system? Does osteocalcin play a large role in problems such as low sperm count and low testosterone, or is it more peripheral?
Scientists now plan to study men with these problems and to measure their osteocalcin levels, Crowley says. Some of them might have a defect in osteocalcin that underlies their condition.
But, he says: ''I suspect this will turn out to be one chapter in an interesting and more complicated mystery.''
Karsenty has long argued that bone plays a central role in regulating body physiology. ''The body is not an assembly of silos that don't speak to each other but is full of surprising examples of crosstalk,'' he says.
In 2007, he showed that bone helps to regulate blood sugar, a result that startled hormone specialists. Working with mice, he reported that osteocalcin boosts insulin production in the pancreas and increases insulin sensitivity. Insulin, in turn, acts to lower blood sugar.
That work could prove relevant to diabetes, in which the body either does not produce enough insulin or stops heeding it.
Now, Karsenty hopes to unravel the complicated links binding the skeleton, sugar and gender. Bone mass tends to decline with age, he notes, as do blood-sugar control and fertility.
''One idea is that bone might not just be a victim of ageing. It might also be a contributor.''
The New York Times
Thursday, August 11, 2011
Male infertility may soon be a thing of the past according to mice. This week new research has been released that Japanese scientists have used laboratory-made sperm, using embryonic cells, to restore fertility in sterile mice. This may open up new avenues for researching and treating infertility in people. For example, men may be able to reprogram cells from the skin to act like sperm producing entities. Read on for details.
Historically, researchers have tried for years to make sperm and eggs in a dish, with limited success and some controversy. In 2003, several groups of scientists showed that it was possible to transform mouse embryonic stem cells into both sperm and eggs, but pregnancy failed.
In 2006 another team used lab-grown sperm to produce six mice, but the animals suffered genetic abnormalities and all died early and in 2009, researchers at Newcastle University made headlines by reporting the creation of human sperm in a test tube. Their paper was retracted weeks later on charges of plagiarism.
Now, the researchers added growth factors and other chemicals that are known to control activities such as cell proliferation and differentiation to mouse embryonic stem cells which had the effect of turning the embryonic cells into epiblast-like cells in a lab dish. These cell types are deposited early in embryogenesis in developing organs and persist in several organs into adulthood.
Next, by replicating the signaling process learned from the 2009 experiment, they coaxed the epiblast-like cells to become primordial germ cells. These primitive germ cells were transplanted into the testes of 7-day-old mice that were sterile and therefore couldn't produce sperm naturally. But they now produced normal-looking sperm. Quite the breakthrough.
The lab-made sperm were used to fertilize eggs in a dish, creating 214 embryos, each comprising two cells. The embryos were transplanted into several female mice, which gave birth to a total of 65 healthy male and female pups.
Dr. Saitou, the research team leader stated:
"The mouse babies are just fine and they've had normal, fertile babies of their own. The pregnancy rate achieved in the mice was comparable to what's typically seen using naturally produced sperm and artificial insemination."
Now this exact process can't be identically replicated in adult male humans, but it may be possible to reprogram a man's mature cells into an embryonic-like state, and coax those cells to become healthy sperm in a dish.
The Japanese scientists did just that. They got reprogrammed mouse cells to turn into lab-made sperm, and then used the sperm to fertilize eggs and produce babies in the mice.
The ability to reprogram cells into an embryonic-like state is one of the most exciting advances in biology. But it is still an unreliable technique since it often requires the use of viruses that can trigger tumors. Not surprisingly, the Kyoto scientists found that 20% of the baby mice produced via reprogramming died prematurely, some from tumors.
George Daley, director of the stem-cell transplantation program at Children's Hospital Boston commented:
"It's a brilliant set of experiments. They restored fertility in the mice. It lays the groundwork for major insights into sperm development and fertility. It would be a monumental achievement since there's currently no method for restoring female fertility."
Monday, May 23, 2011
"Our findings were a little bit puzzling," says Rany Shamloul, a postdoctoral fellow in the Department of Pharmacology and Toxicology and lead researcher on the project. "We were expecting to find different results, but the results we did find suggest that there could be some intriguing mechanisms at work."
The research team discovered that men who reported cell phone use had higher levels of circulating testosterone but they also had lower levels of luteinizing hormone (LH), an important reproductive hormone that is secreted by the pituitary gland in the brain.
The researchers hypothesize that electromagnetic waves (EMW) emitted by cell phones may have a dual action on male hormone levels and fertility. EMW may increase the number of cells in the testes that produce testosterone; however, by lowering the levels of LH excreted by the pituitary gland, EMW may also block the conversion of this basic circulating type of testosterone to the more active, potent form of testosterone associated with sperm production and fertility.
More in-depth research is needed to determine the exact ways in which EMW affects male fertility.
Saturday, May 7, 2011
Males who use laptops on their laps are likely to experience scrotal hyperthermia - elevated temperatures in their testicles - which can significantly affect the quality of their sperm, and consequently their fertility, US scientists report in the medical journal Fertility and Sterility. The authors add that even if they protect their laps with a lap pad, scrotal hyperthermia still occurs. The only way a male can be sure to protect his fertility when using a laptop is by placing it on a desk, using it with legs apart while using a lap pad for no longer than 28 minutes, or using the laptop on his lap with knees together for very short periods.
Yelim Sheynkin, M.D. (urologist) and team from the State University of New York at Stony Brook set out to evaluate how to prevent scrotal hyperthermia among male laptop users. Their study involved 29 health male volunteers.
The scientists measured the temperatures of the left and right side of the scrotum, as well as the laptop and lap pad during three separate 60-minute sessions - all the participants were using a laptop in the following ways:
· Sitting with their knees together (approximated legs) and the laptop on their laps
· Sitting with their knees together, laptop on lap, and with lap pad between their laptops and their laps
· Sitting with their legs apart at a 70° angle, laptop on lap, and with lap pad between their laptops and their laps
Their goal was to measure any rise in scrotal temperatures.
The authors wrote that scrotal temperatures went up considerably, in spite of the position of their legs and whether or not they used a lap pad.
Scrotal temperature did go up less and the rise occurred later when the men had their legs apart at a 70° angle. However, even then, the rise in scrotal temperature was cause for concern.
Below are some of the highlighted results:
· Knees together, laptop on lap (no lap pad)
Scrotal temperature rise - left side from 0.96C to 2.31C, right side from 0.91C to 2.56C.
The scrotum started rising in temperature within 11 minutes.
· Knees together, laptop on lap, using lap pad
Scrotal temperature rise - left side from 0.69C to 2.18C, right side from 0.72C to 2.06C.
The scrotum started rising in temperature within 14 minutes.
· Legs apart, laptop on lap, using lap pad
Scrotal temperature rise - left side from 0.66C to 1.41C, right side from 0.62C to 1.47C.
The scrotum started rising in temperature within 28 minutes.
The authors wrote in conclusion:
Sitting position with closely approximated legs is the major cause of scrotal hyperthermia. Scrotal shielding with a lap pad does not protect from scrotal temperature elevation. Prevention of scrotal hyperthermia in LC users presently is not feasible. However, scrotal hyperthermia may be reduced by a modified sitting position (legs apart) and significantly shorter use of LC.
Thursday, January 27, 2011
Couples who struggle to conceive could find baby-making help from antioxidants such as vitamin E and zinc, hints a new review of more than 30 studies.
The researchers focused on men who were subfertile — less fertile than average but still capable of making a baby — and found that those who took antioxidants were more than four times as likely to get their partners pregnant than subfertile men who did not take the supplements.
The New Zealand team stops short of saying that antioxidants actually improve fertility, however. More research is needed to be sure.
Subfertility affects one in 20 men and is responsible for half of delayed conceptions. Up to 80 percent of cases are thought to be due to the effects of oxidative stress on sperm cells, lowering both their numbers and their quality.
Oxidative stress happens when molecules known as free radicals, byproducts of cell metabolism, damage DNA and cells' ability to function. Antioxidants, including certain vitamins and nutrients, help to protect cells by stabilizing free radicals.
This has led some experts to wonder if antioxidants might help sperm stay swimmingly healthy.
"Oral supplementation with antioxidants may go some way to improve a couple's chance of conception," lead researcher Marian Showell of the University of Auckland, in New Zealand, told Reuters Health in an e-mail.
To see if the research to date backs up that idea, Showell and her colleagues reviewed 34 studies that involved nearly 3,000 couples undergoing fertility treatments, including in vitro fertilization and intrauterine insemination — two of the most commonly used methods of boosting conception odds when sperm-related issues are involved. Each study investigated the potential role of one or more antioxidants.
Based on 96 pregnancies among 964 couples in 15 of the studies, the researchers found that antioxidant use by the male partner increased the odds of conception four-fold.
Further, men taking antioxidants improved the likelihood of their partners giving birth to a live baby by a factor of five, the researchers report in The Cochrane Library. Only three of the studies contained data on live births, however.
"The findings of increased live birth rates with antioxidants are based on a total of only 20 births — a relatively small number," Dr. Mark Sigman of Brown University, in Providence, R.I., who was not involved in the review, told Reuters Health in an e-mail.
Sigman, whose research found no improvement in semen quality with the antioxidant carnitine, was cautious about making too much of the review's results.
The included studies did not use the same types or numbers of antioxidants, he added. As a result, the researchers could not determine the effectiveness of individual supplements.
In addition to oral supplements, antioxidants can be found in a range of foods, from cranberries to collard greens, tomatoes and mozzarella cheese.
Both Sigman and Showell cautioned that couples should not count on antioxidants to overcome their fertility challenges. Even if certain supplements prove effective, further research is needed to determine which couples could reap the specific benefits.
"It is unrealistic to think one treatment will be good for most couples," noted Sigman.
"There is no evidence that antioxidants cause harm," he added. "But since we also don't know which antioxidants or doses are beneficial, and none have FDA approval for infertility — consumers are left with purchasing these based on very limited data."