What Makes a Male?

Drs. Norbert Herzog & David Niesel

Drs. Norbert Herzog & David Niesel

Medical Discovery News 

Despite centuries of women being celebrated for siring sons, or scorned for failing to produce an heir, it is actually men who determine a baby’s gender. Women give each of their offspring an X chromosome, but the male can give an X or a Y chromosome to create a female (XX) or male (XY), respectively. But how much of the Y chromosome is required to make a male? It turns out only two genes are needed to create a male mouse, a species that determines gender the same as humans.

Humans have 23 pairs of chromosomes, one of which is the sex chromosome. Chromosomes contain lots and lots of genes, all which carry instructions that tell different parts of the body what to do. In males, the Y chromosome carries a gene called SRY that encodes the Sex-determining region Y (also abbreviated SRY) protein. This protein, as its name suggests, will decide the sex of future offspring. Consequently, this one single gene, SRY, is all that’s required to produce an anatomically male mouse. However, these male mice are infertile because they lack some of the genes involved in sperm production.

That’s where another gene called Eif2s3y comes in. With this second gene, male mice can at least generate sperm cell precursors known as round spermatids, but not mature sperm. To fully develop sperm, the mice need both copies of this gene. One is toward the end of the Y chromosome and the other version is on the X chromosome. Continue reading

4 key questions, 7 steps to health

Dr. Victor Sierpina

Dr. Victor Sierpina

The noted heart surgeon Christiaan Barnard once said that our goal in life should be “to die young, as late as possible.”

These words of wisdom suggest that we need to tend to those things that keep us young functionally, mind, body and spirit. As we ascend in age, our goal should be to postpone as long as we can the depredations of unhealthy aging, premature disease and loss of function.

At a recent national conference for the Osher Lifelong Learning Institutes, a nationwide organization including an OLLI here in Galveston that is dedicated to promoting healthy aging, I heard a terrific and highly practical presentation.

The keynote speaker was a friend of mine, Dr. Margaret Chesney, head of the University of California in San Francisco’s Osher Integrative Medicine Center and also former head of the National Institutes of Health National Center for Complementary and Alternative Medicine.

Dr. Chesney shared data that showed the answer to four simple questions can largely determine how healthy your lifestyle is.

The four questions were:
1. Are you a nonsmoker?
2. Is your Body Mass Index (BMI) less than 30?
3. Do you engage in mild or moderate physical activity at least 21⁄2 hours per week?
4. Do you eat at least five servings of fruits and vegetables daily?
Continue reading

Testosterone plays role in obesity for men

Dr. Victor Sierpina

Dr. Victor Sierpina

Men, there is now a simple medical biomarker at-home test for you called CYCYP.

Look straight down and see if you can see your … mmm, anatomy. If not, likely you are suffering from visceral or belly fat, or maybe you have a vision problem.

For many years, we guys have thought of the obesity issue as something that mainly troubled the fairer sex.

It seems it has always been culturally appropriate for the ladies to be concerned about their shapely figures and how to stay attractive for us guys.

We men rarely, if ever, seem to be concerned or even discuss such matters outside of the gym.

However, the surprising news is that obesity or overweight rates for men are at 72 percent and rising, and for women it is 64 percent and stable.

Men also have a higher risk of cancer, diabetes and heart disease with a life expectancy of 76 years compared to 81 for women. Continue reading