Medical News from Johns Hopkins

This is a service for doctors worldwide from Johns Hopkins International.  To receive reports directly, please send e-mail to jhis@jhmi.edu or visit www.jhintl.net.

May 2004

1.  Zinc Therapy Accelerates Recovery from Pneumonia
2.  Tumor Suppressor Gene Family Linked to New Colon Cancer Drugs
3.  Urine Protein Test May Predict Kidney Transplant Rejection
4.  High Testosterone Linked to Increased Prostate Cancer Risk

1.  Zinc Therapy Accelerates Recovery from Pneumonia

Treating young children with zinc in addition to standard antibiotics greatly reduces the duration of severe pneumonia, according to researchers at Johns Hopkins and the International Centre for Diarrhoeal Disease Research, Bangladesh.  Pneumonia is a leading cause of illness and death among children under age 5, particularly in the developing world. The researchers believe zinc therapy could help reduce antimicrobial resistance by decreasing the exposure to multiple antibiotics and lessen the health complications and deaths worldwide caused by severe pneumonia. The study appears in the May 22, 2004, edition of The Lancet.

"Our study shows that adding zinc to the standard antibiotic treatment significantly reduces the recovery time and overall hospital stay of children with severe pneumonia," said lead author W. Abdullah Brooks, MD, MPH. "The children who received zinc were also less likely to need a change in the antibiotic being used. This could have significant implications for reducing antibiotic-resistant infections by decreasing antibiotic exposure," he said.

2.  Tumor Suppressor Gene Family Linked to New Colon Cancer Drugs

Scientists from Johns Hopkins and the Howard Hughes Medical Institute have discovered mutations in a family of genes linked to more than a quarter of colon cancers as well as several other common cancers, including breast and lung.  Their research, published in the May 21 issue of Science, reveals more options for creating personalized therapies tailored to counteract mutated gene pathways present in individual tumors.

"What makes this discovery significant is that we've found mutations that directly affect cancer development," says Victor Velculescu, M.D., Ph.D.  "Most gene discoveries today focus on finding increased or decreased activity of a gene that may not affect cancer progression, akin to passengers on a bus that can't control its speed or direction.  What we have found are the brakes of the bus. If a bus' brakes are broken and they can't be fixed, another way to slow it down is to let up on the accelerator," explains Velculescu.  "In this case, the faulty brakes are mutated tyrosine phosphatases and the accelerators are the tyrosine kinases."  Tyrosine kinases have been of critical value in the success of such cancer-fighting drugs as Gleevec, Iressa and Herceptin, which block proteins made by tyrosine kinase genes.

3.  Urine Protein Test May Predict Kidney Transplant Rejection

Hopkins researchers have developed the basis of an inexpensive, simple urine test that identifies impending kidney failure or rejection after transplant surgery.  Their work, presented last week in a special lecture to the American Transplant Congress in Boston, is based on proteins found in urine, and could lead to a urine test kit that may allow many patients to skip painful biopsies. 

"This has the potential to radically change the way transplant patients are managed," says study co-author Ernesto Molmenti, M.D., Ph.D.  "Frequent, noninvasive monitoring could allow doctors to better tailor immunosuppression drugs according to individual patient's needs, prescribing lower doses to more stable patients or increasing doses for patients who show early signs of rejection."  Molmenti estimates that the test, when developed, will be far less expensive, safer and much less painful than a standard biopsy.  Unlike kidney biopsy, a urine test is risk-free, presents no discomfort or restraints to the patients, and samples the entire kidney accurately.

4.  High Testosterone Linked to Increased Prostate Cancer Risk

Men over 50 with high levels of testosterone in their blood have a higher risk of prostate cancer say researchers at Johns Hopkins and the National Institute on Aging. The study was presented at the Annual Meeting of the American Urological Society in San Francisco.  The finding throws some doubt on the safety of testosterone replacement therapy, the investigators say.  The researchers measured several forms of testosterone in 3,000 blood samples.  One form called free testosterone, which is actually used by the prostate, was associated with increased prostate cancer risk, according to Hopkins urologist J. Kellogg Parsons, M.D., lead researcher of the study.  "Since testosterone replacement therapy increases the amount of free testosterone in the blood, older men considering or receiving testosterone replacement should be counseled as to the association until data from long-term clinical trials becomes available," says Parsons.