First Study Begins To Treat Retinoblastoma Using Gene Therapy

A new technique using gene therapy to save the sight of children with retinoblastoma is under study at Texas Children's Cancer Center. Retinoblastoma is a rare tumor of the eye, most often striking children under age 3. It causes blindness and may in some cases be life threatening.

"The traditional treatment has been to remove one or both of the diseased eyes. Treatment might also involve chemotherapy and/or radiation, but the toxicity often produces a second cancer in the bone surrounding the eye," says Dr. Richard Hurwitz, principal investigator of the study and associate professor of pediatrics at Baylor College of Medicine. "Our technique reduces or eliminates these devastating effects."

Researchers will inject a portion of a viral gene into the tumor. The gene will infect the tumor so the cells become susceptible to an anti-virus drug. The anti-virus drug injected into the tumor kills the genetically altered cells and shrinks the tumor. According to Dr. Hurwitz, the patient receives only a segment of the virus and is in no danger of contracting the virus.

"The gene and the drug work in combination to start a suicide process within the tumor. Similar treatments have been used to treat patients with prostate cancer and brain tumors, but this will be the first time that the technique will be studied to treat retinoblastoma," Dr. Hurwitz says. The shrunken tumor can later be removed through laser surgery or by cryosurgery, a technique to freeze the tumor.

Cancer center researchers and physicians will work cooperatively with a team of ophthamologic specialists at Baylor.

"It's exciting that this treatment may save most of a child's eyesight, avoid facial deformities from the removal of one or both eyes, and eliminate the risk of a second cancer," Dr. Hurwitz says.

- From the Texas Children's Cancer Center

Periodontal Treatment That's Easy to Swallow

Drugs for the treatment of periodontal disease are helping many patients avoid costly, invasive surgery. In the last year, three new medications which attack gum disease right at the source have become available.

Atridox(tm) is a gel impregnated with a powerful antibiotic. It's injected into the pocket and hardens, releasing the drug over seven to 10 days to destroy periodontal bacteria. It is used on moderate to severe gum disease.

PerioChip(tm) is a tiny square containing chlorhexidine, a common agent in prescription mouthwashes. The chip is inserted into the perio pocket and dissolves, releasing a concentrated dose. Clinical trials have shown significant reduction in the size of the pockets, making overall gum maintenance much easier.

Periostat(tm), which comes in pill form, contains a low dose of an antibiotic that blocks the body's production of collagenase, an enzyme produced by inflammation which destroys collagen, the main component of gum tissue. It is taken daily for two to three months after scaling and root planing, and can decrease the size of perio pockets by up to 67 percent.

Raul Caffesse, D.D.S., M.S., chairman of the periodontics division at The University of Texas-Houston Dental Branch, says that while these new drugs are improving the outcome of periodontal treatment, they do not replace the traditional methods of tartar removal with dental instruments.

- From The University of Texas-Houston Health Science Center

Study Tests Use of Drug to Stop Ectopic Pregnancy

A new study will examine the effectiveness of a drug designed to dissolve an ectopic pregnancy, a condition where a fertilized egg begins to develop outside the uterus.

Occurring around the time of the first missed period, the egg is usually stuck in a fallopian tube. If a rupture occurs, it can be life threatening. A new pilot study at Baylor College of Medicine will determine how much of the drug, methotrexate, is needed to dissolve the pregnancy, and avoid surgery.

"The key to saving the life of a woman with an ectopic pregnancy is early diagnosis," says Dr. Sandra Carson, director of Baylor's Assisted Reproductive Technology (ART) program. "We believe this drug will be effective, and might one day do away with the need for surgery, which sometimes hurts a woman's chances to have children down the road."

Women have about a one in 300 chance of having an ectopic pregnancy. Symptoms include bleeding, a pain in the side, and lightheadedness before the pregnancy ruptures. Those who have had tubal surgery, pelvic infections, numerous miscarriages, or used fertility drugs are at greater risk of having this type of pregnancy.

- From Baylor College of Medicine

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©2006 Texas Medical Center

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