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Gene therapy moves forward
Despite their promise, technologies to correct defective genes have been plagued by safety problems leading to unintended — and sometimes fatal — outcomes. But scientists are inching toward safer, more effective gene therapies that may one day treat a range of diseases, from psychiatric disorders to autoimmune diseases to cancers.
Studies in animals and isolated cells in the lab are showing promise. In mice, correcting gene function reverses depression-like behaviors (SN: 11/20/10, p. 14), blindness (SN: 7/17/10, p. 11) and type 1 diabetes.
Researchers have also pushed forward on tests of gene therapy in humans. Small clinical trials have had preliminary success in treating several rare disorders, though not without risks. A study published in the July 22 New England Journal of Medicine reports that eight to 11 years after nine children underwent gene therapy for severe combined immunodeficiency (widely known as bubble boy syndrome), seven of the children had improved immune systems. Four of the children, however, developed leukemia, and one died.
Researchers also report in the Nov. 11 New England Journal the successful treatment of two boys with a rare immune disease called Wiskott-Aldrich syndrome. Introducing a functional copy of the disease-causing gene improved the boys’ symptoms, and both were doing well more than two years after the therapy.
Gene therapy still faces many hurdles before it can become a common, safe and effective treatment, but today things look more hopeful, researchers say. “We’re certainly in much better shape than we were 10 or 15 years ago,” says Cynthia Dunbar of the National Institutes of Health in Bethesda, Md. “Things looked pretty grim in the 1990s, but now there are clear clinical advances moving us forward.”
Stroke timing Magnetic resonance imaging done promptly when a patient arrives at a hospital could pinpoint when a stroke began, rendering more patients eligible for clot-busting therapy that can limit brain damage (SN: 12/4/10, p. 12).
Heartburned Proton pump inhibitors are great at blocking stomach acid, but their overuse could pose health risks (SN: 12/4/10, p. 30).
Aha! Sudden insight occurs when neurons in the brain alter their activity all at once (SN: 6/5/10, p. 9).
Early detection High levels of the protein EGFR can show up 17 months before breast cancer is diagnosed (SN: 5/22/10, p. 15).
Whisker therapy A study in rats suggests that rubbing a stroke victim’s face or fingers right after onset might reduce brain damage (SN: 12/4/10, p. 14).
Artificial eye A new type of prosthetic retina can analyze patterns of cell activity to reproduce images similar to those produced in normal vision (SN: 12/4/10, p. 14).
Beyond a buzz Components in marijuana (left) show potential against pain, multiple sclerosis, Crohn’s disease and even cancer (SN: 6/19/10, p. 16).
Barrier builders The blood-brain barrier, which keeps both bacteria and some drugs out of the brain, relies on cells called pericytes, a discovery that scientists hope to exploit to better understand brain diseases and trauma (SN Online: 10/13/10).
HDL booster A new drug called anacetrapib more than doubles “good” cholesterol and lowers bad forms in study volunteers, paving the way for a large clinical trial (SN: 12/18/10, p. 14).
So sleepy A survey finds that only 7.6 percent of U.S. teens get the ideal quota of sleep most nights — and about 16 percent average no more than five hours (SN Online: 1/8/10).
Years in the making In pancreatic cancer, a decade can elapse from the first cancer-related mutation to tumor formation, and several more years pass before the disease spreads to other organs. The work raises the possibility that an often deadly malignancy can be treated before it’s too late (SN: 11/20/10, p. 9).
Marburg vaccine An experimental vaccine can waylay the deadly tropical virus even after exposure, tests in monkeys show (SN: 7/31/10, p. 12).
MicroRNAs anonymous Increasing levels of the microRNA miR-212 in rats’ brains helps protect the rodents from cocaine addiction (SN: 7/31/10, p. 11).
Tossing and turning Violent dreams can precede brain disorders by decades (SN: 8/28/10, p. 9).
Insulin insight Renal failure in people with diabetes may be linked to poor insulin uptake by kidney cells called podocytes (SN: 11/6/10, p. 11).
Not-so-total recall Older mice lose genetic packaging that helps activate genes involved in making memories (SN: 6/5/10, p. 8).
Medical roach Ground-up brain tissue from cockroaches and locusts contains antibacterial compounds that might lead to new drugs for fighting infectious diseases in humans (SN: 10/9/10, p. 14).
Taste cells all over Taste receptors throughout the gut, not just on the tongue, help activate the digestive system in response to incoming food (SN: 3/27/10, p. 22). In the lungs, taste receptors open airways in response to acrid gases, perhaps to ventilate infected tissue (SN: 11/20/10, p. 8).
Say what? Teen hearing-loss rates have risen by a third since tests in the 1980s and ’90s (SN: 9/11/10, p. 14).
New stem cell source Injecting stem cells harvested from fat tissue into coronary arteries could limit damage after a heart attack (SN: 12/18/10, p. 15).
Disease transplants Organ donors can unwittingly share a toxic bonus, such as brain-seeking amoebas, case reports reveal (SN Online: 9/24/10).
Muscle memory Muscles store memories of past fitness in the form of extra nuclei (bright green, below) that allow muscle cells to rebound quickly after a period of disuse. The find suggests that working out early in life could help stave off frailness later (SN: 9/11/10, p. 15).
HIV advances Giving an antiretroviral drug mix to men at high risk of HIV may help prevent infection (SN: 12/18/10, p. 16). For women not already infected, a new vaginal gel shows promise as a preventive (SN: 8/14/10, p. 9). Research also shows that HIV drugs could prevent millions of TB cases in Africa (SN Online: 2/21/10). Scientists find that having high levels of the tumor-suppressing protein p21 may fend off HIV (SN: 11/20/10, p. 9). What’s more, people infected with HIV but able to keep the virus in check often make a variant form of the HLA-B protein (above), new work shows (SN: 6/5/10, p. 8; SN: 12/4/10, p. 12).
Genetic TB prognosis Profiles of gene activity in the blood of people infected with tuberculosis can help predict who will get sick, and possibly head off lung damage or save people from unnecessary treatments (SN: 9/11/10, p. 15).