By ANN LUKITS
Researchers have developed a new vaccine to desensitize people with a cat allergy that is faster and safer than traditional immunotherapies, according to a study in the Journal of Allergy and Clinical Immunology. Cat allergy affects up to 10% of the general population and is a key trigger of childhood asthma. Standard treatment involves weekly injections of cat allergen in incremental doses for a year or more, but severe allergic reactions are a risk. The new vaccine, developed in Canada, uses synthetic versions of short peptides from the protein responsible for most cat allergies. The peptides are 1,000 times less allergenic than traditional cat allergen, researchers said. The vaccine was tested on 66 volunteers; another 22 received a placebo. Skin responses, an indicator of the severity of an allergy, were measured after eight hours and compared with reactions to cat allergen. Adverse responses in the vaccinated group were reduced by 40% and 10% in the placebo group. Researchers said the results are comparable to a year of traditional immunotherapy. The vaccine, which is in the final stage of development, is expected to require four shots at the same dose.
Caveat: Two vaccinated subjects and one in the placebo group had mild asthma symptoms, but no one withdrew from the study. A continuing study by a U.K. biopharmaceutical company is expected to determine the duration of the vaccine's effect.
HDL and cancer: A new technology that uses high-density lipoprotein, or good cholesterol, as a carrier for anti-cancer compounds significantly reduced the number and size of ovarian tumors in mice, according to a study in Neoplasia. Studies have shown that cancer cells produce an HDL receptor to seek out HDL particles circulating in the bloodstream, which help cancer cells to grow and multiply. By exploiting this unique relationship between good cholesterol and cancer cells, researchers in Texas used HDL to deliver small interfering RNA (siRNA) directly into mice tumors. Interfering RNA is known as silencing RNA because of its ability to shut off genes that are difficult to target using conventional approaches, such as antibodies or small molecule inhibitors. The technology was tested on two genes that are over-expressed in ovarian and other cancers, and reduced the number and size of mice tumors by 60% to 80%. Chemotherapy further reduced tumors by more than 90%. The technology could serve as the foundation for new cancer therapies, researchers said.
Caveat: The technology hasn't been tested on humans.
PMS and Vitamin B: Women can reduce their chances of developing PMS by eating foods rich in certain B vitamins. But supplements containing these vitamins don't offer the same benefit, according to a study in the American Journal of Clinical Nutrition. Premenstrual syndrome affects 1 in 6 U.S. women of childbearing age. From 1991 to 1999, researchers administered four food surveys to 3,025 women, of whom 1,057 had confirmed PMS and 1,968 were PMS-free. Their use of supplements also was surveyed. Women who consumed food containing about 2.5 milligrams of riboflavin a day had a 35% reduced risk of PMS compared with those who consumed 1.4 mg per day. A diet high in thiamine resulted in a 25% lower risk of PMS. Thiamine and riboflavin are found in fortified cereals, milk, red meat, seafood, beans, bananas and leafy green vegetables. There was no link between PMS and B-vitamin supplements or foods and supplements containing other B vitamins, such as niacin, vitamin B-6, folate, and vitamin B-12. Researchers said foods rich in B vitamins may have components not found in supplements that affect PMS risk.
Caveat: Any beneficial effects of vitamin B-6 may have been missed because the amount of this vitamin in the supplements used was very low, researchers said. A separate study in 2007 found a reduction in PMS symptoms in women who received vitamin B-6 supplements for three months.
Heart link to headaches: A common heart abnormality may contribute to migraine headaches in children, particularly those with visual disturbances called auras, according to a study in the Journal of Pediatrics. Between 10% and 25% of the general population has a small hole between the heart's upper chambers called patent foramen ovale (PFO). The gap is routine in a fetus to allow oxygen to flow directly from mother to baby, but is supposed to close after birth. Previous research has suggested a link between PFO and migraines in adults, but this is the first study to examine PFO in children with migraines. Heart scans were taken on 109 Utah children ages 6 to 18 who were diagnosed with migraines from 2008 to 2009. PFO was present in 50% of 38 children with migraine auras and 27% of 71 without auras. Researchers said PFO may cause a cardiac shunt or passage that allows metabolic triggers to bypass the lungs and flow into the brain, triggering migraines with auras. Assessing for PFO could become routine in children with migraines, they said.
Caveat: For ethical reasons and concerns regarding recruitment, researchers were unable to place intravenous lines in a healthy control group to determine the prevalence of PFO. Instead, the study data were compared to the upper end of the 10%-to-25% range for PFO prevalence in the general population, they said.
Psychotherapy vs. drugs: Antidepressants and psychotherapy each can be equally effective treatments for depression but only if the therapy is led by a licensed practitioner and based on established psychological principles, according to a study in the Journal of Nervous and Mental Disease. In the U.S., treatment with antidepressant medications has more than doubled in the past decade while the use of psychotherapy has declined. Most medications prescribed for depression belong to a newer class of drugs called second-generation antidepressants (SGA), which inhibit chemicals called neurotransmitters. Many studies have found psychotherapy and SGAs to be roughly equivalent therapies but methodologies varied widely. A meta-analysis of 15 studies comparing psychotherapy with SGAs in 1,975 patients found insignificant differences on depression scales or response, remission and study-completion rates, if the psychotherapy was bona fide or led by a trained therapist. The study found therapy led by health practitioners with minimal or unclear training in psychotherapy was statistically inferior to antidepressant medication and an inadequate treatment for depression.
Caveat: A number of trials included in the analysis excluded severely distressed individuals, didn't describe criteria used to exclude them, and didn't provide patients' history and severity of depression.
Medication mistakes in kids: Medication errors are common in homes with children who have chronic health conditions requiring complex medication regimens, according to a study in Archives of Diseases in Childhood. From 2007 to 2009, researchers from an academic health center in Massachusetts reviewed 280 medications prescribed for children with sickle cell disease and seizure disorders. During 52 home visits, they found 61 medication errors, including 31 that could harm the child and nine that prolonged a treatable condition. About one-fourth of the errors involved children missing more than half the required dose, 25% were administering mistakes, 16% involved expired medications, 16% involved medications forgotten at the pharmacy, 6.5% were incorrect doses, 6.5% were prescribing errors and 3.5% were due to language barriers. Mothers were responsible for administering medications in 36 of the 52 visits. Children self-administered their meds in 10 cases and fathers or nurses in six. The study found many parents lacked a calendar, pillbox, chalkboard or other reminder tool. More research is needed on how to prevent mistakes at home, researchers said.
Caveat: Some clinically serious errors could have been missed if a child had to be admitted to hospital, researchers said. Parents may have been more careful with medications due to the researchers' presence in their home. Future research at multiple locations may make the findings more generalizable, researchers said.