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Medical Edge Newspaper Column from Mayo Clinic

‘BIOLOGICAL CLOCK’ A REAL FACTOR TO CONSIDER

DEAR MAYO CLINIC: My wife and I are in our early 30s and not yet ready to start a family — though we agree we both want one. My wife’s internist told her that if she was planning to have children, she should change her career plans and start trying to conceive now! This shocked us. We also know all kinds of people in their 40s having children. We’ve even considered freezing eggs now for use later, but friends say this is risky. Is it? Should we have our fertility tested? — Atlanta

ANSWER: Yes. Freezing eggs is currently a developing technique with very low success rates. It’s not usually offered as a way to preserve fertility. However, freezing embryos created during the in vitro fertilization process is a viable option with good success. This is currently the most common technique offered to women before they undergo radiation or chemotherapy treatments for cancer — which are potentially sterilizing.

IVF (with freezing of excess embryos) is used for many reasons. They include fallopian-tube damage, endometriosis, pelvic adhesions, sperm problems and unexplained infertility. It is the most successful of all fertility techniques in terms of pregnancy rate per cycle.

Your wife’s internist is giving her the correct biological information. The “biological clock” is very real. A woman’s peak fertility is in her late 20s. While it’s true that pregnancies do occur as women get older, overall, there are fewer pregnancies. There are also higher rates of miscarriage in older pregnant women and more birth defects in their children.

We usually recommend undergoing fertility testing under the following conditions: 1) if you are over 35 and have not gotten pregnant after six months of trying; or 2) if you are under 35 and have not gotten pregnant after one year of trying. Following testing, you will work with your doctor to develop an appropriate treatment plan. IVF is just one of several treatment options.

Anita Singh, M.D., Reproductive Endocrinology and Infertility; Mayo Clinic, Scottsdale, Ariz.

Additional Resources:
Fertility
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DEAR MAYO CLINIC: Why is it so hard to find a cure for HIV/AIDS? — Houston

ANSWER: There is no single, easy answer to your question. But from a virologist’s point of view, one of the most difficult aspects of controlling the HIV virus is the problem of the “latent reservoir.”

The latent reservoir is the ability of the HIV virus to exist in cells that are in a resting, or latent, state. Our current HIV drugs work only on cells that are replicating — not on those that are resting. Thus, the latent HIV virus “hides” in the body to form a pool — or reservoir — of potential infection that can be activated later. As a result, the resting reservoir serves as a kind of HIV time bomb that can detonate if a patient stops HIV treatment or becomes resistant to current drugs.

In my view, any true cure for HIV infection and AIDS will have to overcome the problem of the latent reservoir. Researchers worldwide are investigating this problem and producing encouraging findings. Such approaches include both existing and experimental drugs (including one called prostratin derived from a Samoan herbal remedy) that activate the latent cells, theoretically making these cells sensitive to current anti-HIV drugs.

Alternatively, some researchers have developed antibodies that are engineered to contain a toxin. Such synthetic antibody-toxin hybrids are designed to specifically target both actively and latently infected cells with the help of the antibody portion of the molecule, and then kill the cells with the help of the toxin portion.

Another approach uses a natural molecule called TRAIL. Early laboratory results suggest that TRAIL has potential to treat HIV in the resting reservoir. TRAIL is interesting because it seeks out abnormal cells, such as cancer, as well as some virally infected cells, such as HIV. Then, after identifying abnormal cells, TRAIL sends signals to them that prompt the cells to commit suicide. Importantly, the message to self-destruct is given selectively — which means TRAIL leaves healthy cells unharmed.

This seek-and-destroy ability of TRAIL also is under investigation for the treatment of certain cancers. It is just one example of the many novel approaches researchers are pursuing to stop this deadly virus and the suffering it causes.

Andrew Badley, M.D., Immunovirology; Mayo Clinic, Rochester, Minn.

Additional Resources:
Treatment of HIV/AIDS
Appointment Information
HIV/AIDS Information
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Medical Edge from Mayo Clinic is an educational resource and doesn’t replace regular medical care. To e-mail a question, go to www.mayoclinic.org, or write: Medical Edge from Mayo Clinic, c/o TMS, 2225 Kenmore Ave., Suite 114, Buffalo, N.Y., 14207. For health information, visit www.mayoclinic.com.