One gene to change sexes

Faulty gene linked to disorders of sexual development

Scientists have discovered that the  alteration of a single gene could cause some male embryos to develop as females.

"These conditions occur when the testis or ovary does not develop properly in the embryo, causing genital abnormalities in one6 in 4500 babies."

 

The breakthrough will improve diagnosis and clinical management of patients with disorders of sex development (DSD). These conditions occur when the testis or ovary does not develop properly in the embryo, causing genital abnormalities in one in 4500 babies.

An international team including University of Melbourne researchers at the Murdoch Childrens Research Institute identified the gene alteration in a group of patients including two families with several affected members.

The alteration occurred in a gene called MAP3K1, which plays a role in switching on genes that direct the gonad to become a testis. Males normally have one X and one Y chromosome and females have two X chromosomes. But researchers found that the alteration of the MAP3K1 gene disrupted the normal process of testis development, resulting in a male XY embryo developing female characteristics including female genitalia and an overall feminine appearance.

Professor Andrew Sinclair, lead researcher from the University of Melbourne and Murdoch Childrens Research Institute said the discovery showed the underlying cause of testis failure in these patients, which would help provide a diagnosis and guide clinical management of cases in the future.

“To date, we know of only a small number of genes that are involved in gonad development, and can only diagnose about 20 per cent of DSD patients,” he said.

“Based on our study, we believe mutation of the MAP3K1 gene could be responsible for a further 20 per cent of XY DSD cases. This is a major breakthrough as the MAP3K1 gene provides new insights into normal testis development and significantly increases the number of DSD cases we can diagnose in the future.”

The study, published in Dec 7 2010 in the American Journal of Human Genetics, was undertaken in collaboration with the Women’s and Children’s Hospital, Adelaide, New York University School of Medicine, MRC Mammalian Genetics Unit, UK, Centre Hospitalier Universitaire de Nantes, France.

Birth Control for Women Over 30

Finding the right contraceptive

Fallen out of love with your birth control? Maybe you’re put off by side effects. Or remembering to pop a pill isn’t your strong suit.

Problem is, going without isn’t a good choice, even as you get older: Nearly 40% of pregnancies among women in their 40s, for instance, are unplanned.

Which one is best for you? We’ve assembled some popular choices here. (However, there are other methods, such as the diaphragm, female condom, NuvaRing, and the Patch, that we didn't include).

Combo pill
: Who can try it?

Almost all women.

Sur­prised? Truth is, a growing body of research debunks some myths surrounding this 99%–effective form of contraception—like the notion that it brings on menopause or ups the risk for some cancers.

The Pill can ease maddening peri­menopausal symptoms like hot flashes, hormonal mood swings, and irregular bleeding.

What’s more, it may help prevent ovarian and uterine cancers.

Combo pill
: Who should avoid it?

If you’re a migraine sufferer, you may want to steer clear; the Pill is thought to trigger headaches and raise the risk of stroke in some migraineurs. (Experts aren’t sure why, but the dip in estrogen during the “off week” is one suspect.)

And smokers older than 35—that includes the I-only-light-up-when-I-drink crowd—should avoid the Pill, as both estrogen and smoking cause blood to clot more easily.

Progestin-only pill
: Who can try it?

Women who are breast-feeding (this oral contraceptive will not lower milk supply), or those who can’t take estrogen-based pills due to cardiovascular disease or blood-clot risks, or because they smoke.

Like the combo type, this “mini-Pill” protects against pregnancy via a low dose of hormones, but it’s estrogen-free.

Note: The progestin-only Pill is slightly less failure-proof than the combo kind.


Progestin-only pill
: Who should avoid it?

If you’re schedule-challenged, take heed: Progestin-only pills must be taken every day at the same time to be fully effective; use a backup method if you get off-schedule.

Extended-cycle pill
: Who can try it?

Women who really loathe their periods.

If you suffer from severe PMS, or if your period exacerbates an existing condition such as endometriosis or anemia, these pills may be your new best friend.

Two brands, Seasonale and Seasonique, allow you to go three months without menstruating—you’ll have just four periods a year.

Another brand, Lybrel, stops periods for an entire year, but you do have to take a pill every day, year-round. Like combo pills, all of these contain estrogen and progestin.


Extended-cycle pill
: Who should avoid it?

If you’re not a candidate for the combo Pill, don’t go the extended-cycle route.

Ditto if you tend to be cautious about new medical trends: Although there’s no evidence suggesting that it’s dangerous not to have regular periods, there is less long-term research behind extended-cycle pills than the combo type.

Intrauterine device (IUD)
: Who can try it?

Women who don’t want to think about birth control for a long, long time.

The IUD is more than 99% effective and lasts for up to 12 years—get one at 40 and you’re set until menopause.

The traditional IUD is a small, T-shaped plastic device that’s inserted into the uterus to block egg fertilization. Insertion can cause mild discomfort for some women, but that doesn’t last.

Downsides: possibly, heavy periods and increased menstrual cramping. That’s where Mirena—a newer model that also delivers a steady dose of progestin—wins points. Though it taps out after five years, you can expect lighter bleeding over time.

Intrauterine device (IUD)
: Who should avoid it?

If you think you’ll want a baby in a year, other methods may be better.

You’ll be unprotected as soon as you remove the IUD, but its cost—ranging from $150 to $500—can make it a bad investment for short-term contraception.

Implant
: Who can try it?

Women looking for no-fuss, long-term (three years) contraception, or those who aren’t a fit for the combo Pill.

A matchstick-size plastic rod called “Implanon” is inserted in your upper arm, where it releases progestin to suppress ovulation.

Effectiveness? Nearly 100%. Your insurer may cover the $400-to-$800 cost.


Implant
: Who should avoid it?

If you take the herb St. John's wort or are significantly overweight, be warned: Implanon may not work as well for you.



Condoms
: Who can try them?

Women 40 and older who aren’t monogamous and haven’t finished menopause.

Unlike other forms of birth control, condoms protect against most STDs and HIV, and are up to 98% effective at preventing pregnancy when used correctly.

This method also is an easy (and cheap) choice if you’re not all that busy in bed.


Condoms
: Who should avoid them?

If you’re younger than 40, condoms simply aren’t the most foolproof pregnancy-protection, unless they’re paired with another contraceptive (such as the Pill or an IUD).

Sterilization
: Who can try it?

Women older than 35 who are done having kids but OK with having a period.

There are two kinds of permanent sterilization. Tubal ligation is a surgical procedure in which the Fallopian tubes are blocked by an incision, clamp, or cauterization.

And a newer option, called “Essure”, is less invasive and involves the placement of a small metal insert to obstruct the Fallopian tubes.

Sterilization
: Who should avoid it?

Ask yourself some hard questions: If you remarried or lost your only child, would you want the option to have another?

If you’re not 100% sure, a long-term, reversible method such as an IUD may be better.

Emergency contraception

Plan B—emergency contraception—uses a high dose of progestin to halt ovulation or fertilization, or prevent a fertilized egg from attaching to the uterus.

It’s designed as a backup if you forget to take your oral contraception, have a condom malfunction, or fear an unwanted pregnancy for another reason. Like other birth control, Plan B prevents pregnancy.

Although it’s called the morning-after pill, Plan B is effective up to five days after intercourse.

The sooner it’s started, the more effective it will be.

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First Aid: Fact or Fiction?

Four of these common misconceptions will worry you needlessly. One fact may save someone's life.

You Can Call 911 on a Cell phone That Isn't Activated

Fact. Cell phone companies are required by law to put 911 calls through from any phone that has power and can receive a signal. For this reason, an old cell phone is an excellent addition to the first-aid kits you keep in your car and boat (remember to recharge the battery from time to time). Just be aware that because there is no number assigned to the phone, there's no way for 911 to reach you should you be disconnected; you'll have to redial.

Seizure Victims Can Swallow Their Tongues

Fiction. Despite what Hollywood has taught us, it's physically impossible to swallow one's own tongue, and forcing your fingers or a spoon or spatula into someone's mouth is only going to injure you and the victim. At times, a seizure sufferer may sound like he's gagging on his tongue, but by rolling him onto his side, you'll help keep his airways clear.

If Someone with a Head Injury Falls Asleep, They Could Go into a Coma

Fiction. The only reason to keep a person with a head injury awake is to observe her symptoms, say the experts at the American College of Emergency Physicians. And if you're too worried about the victim's symptoms to let her go to sleep, then you should take her to the ER. Otherwise, wish her good night and sweet dreams.

Rabies Requires a Series of Painful Shots to the Stomach

Fiction. Though you will get a series of injections, the treatment is far less distasteful these days. Remarkably, there's still no cure for rabies, and once an infection sets in, it's almost always fatal. The shots you'll get are antiviral: They're designed to keep the virus from taking hold. For that reason, they must be started as soon as possible after a bite. The first shot is given near the bite; over the next 28 days, you'll get 5 or 6 more shots in the arm. That sounds much better than 12 or 24 or 36 shots in the belly, as playground lore would have it.

Cuts Should Be Washed with Hydrogen Peroxide

Fiction. Leave that brown bottle on the shelf and clean cuts and scrapes with running water instead, then apply an antibiotic ointment. Peroxide does kill bacteria that may have invaded a cut, but it also knocks off cells working hard to knit your skin back together. In one study, wounds treated with hydrogen peroxide healed more slowly than those treated with an antibiotic ointment or with an ointment that didn't contain any germ-fighting ingredients. 

From: Instant Health Answers

Obesity Rates Keep Rising, Troubling Health Officials in United State

By DENISE GRADY

Published: August 3, 2010

Americans are continuing to get fatter and fatter, with obesity rates reaching 30 percent or more in nine states last year, as opposed to only three states in 2007, health officials reported on Tuesday.

The increases mean that 2.4 million more people became obese from 2007 to 2009, bringing the total to 72.5 million, or 26.7 percent of the population. The numbers are part of a continuing and ominous trend.

But the rates are probably underestimates because they are based on a phone survey in which 400,000 participants were asked their weight and height instead of having it measured by someone else, and people have a notorious tendency to describe themselves as taller and lighter than they really are.

“Over the past several decades, obesity has increased faster than anyone could have imagined it would,” said Dr. Thomas Frieden, the director of the Centers for Disease Control and Prevention, which issued a report on the prevalence of obesity. Obesity rates have doubled in adults and tripled in children in recent decades, Dr. Frieden said.

If the numbers keep going up, he added, “more people will get sick and die from the complications of obesity, such as heart disease, stroke, diabetes and cancer.”

The report estimates the medical costs of obesity to be as high as $147 billion a year, and notes that “past efforts and investments to prevent and control obesity have not been adequate.”

Researchers blame the usual suspects: too little exercise and too much of the wrong kind of food, which means not enough fruits and vegetables and too many high-calorie meals full of sugar and fat, like French fries, soda and other sweet drinks. Children do not get enough exercise during the school day; Dr. Frieden noted that even in gym classes, students are active for only about a third of the time.

A 5-foot-4-inch woman is obese if she weighs 174 pounds, as is a 5-foot-10-inch man who weights 209 or more, according to the disease centers. Both would have a body-mass index, or BMI, of 30; that index is calculated from height and weight, and scores of 30 or over are defined as obese.

The nine states with obesity rates of 30 percent or more are Alabama, Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Oklahoma, Tennessee and West Virginia. The highest rate, 34.4 percent, was in Mississippi.

People over 50 had higher rates of obesity than those who were younger. The aging of the population may account for some of the general increase in obesity, but not all of it, said Dr. Heidi Blanck, chief of the disease centers’ obesity branch of the division of nutrition, physical activity and obesity.

Non-Hispanic black women had the highest obesity rate, 41.9 percent. Over all, blacks and Hispanics were more likely than whites to be obese, and the more education people had, the less likely they were to be heavy.

Only Colorado and Washington, D.C., had obesity rates under 20 percent. Researchers are not sure why. Dr. William Dietz, director of the nutrition, physical activity and obesity division, said that Colorado had spent money from a state lottery on biking and walking trails and that many people were using them. The state seems to have “a culture of physical activity,” he said.

Dr. Dietz said the relatively low prevalence of obesity in Washington was harder to explain, particularly because the area has a large black population.

He said one explanation may be that many residents ride the subway; studies have shown that compared with people who drive, those who use public transportation tend to be thinner because it involves more walking. In addition, Dr. Dietz said, there is evidence of above-average fruit and vegetable consumption, and higher rates of breast-feeding, both of which are linked to lower rates of obesity.

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