Study finds potential way to make an AIDS vaccine

WASHINGTON - The discovery of immune system particles that attack the AIDS virus may finally open a way to make a vaccine that could protect people against the deadly and incurable infection, U.S. researchers said on Thursday.

They used new technology to troll through the blood of 1,800 people infected with the AIDS virus and identified two immune system compounds called antibodies that could neutralize the virus.

And they found a new part of the virus that the antibodies attack, offering a new way to design a vaccine, they reported in the journal Science.

"So now we may have a better chance of designing a vaccine that will elicit such broadly neutralizing antibodies, which we think are key to successful vaccine development," said Dennis Burton of The Scripps Research Institute in La Jolla, California, who led the study.

"The findings themselves are an exciting advance toward the goal of an effective AIDS vaccine because now we've got a new, potentially better target on HIV to focus our efforts for vaccine design," added Wayne Koff of the International AIDS Vaccine Initiative, or IAVI, which sponsored the study.

Since the AIDS pandemic started in the early 1980s, more than 25 million people globally have died from the virus. The World Health Organization estimates that 33 million are currently infected.

There is no cure, although a cocktail of drugs can help keep the virus under control. Efforts to make a vaccine have failed almost completely.

MUTABLE VIRUS

Part of this is because the virus mutates so much that any one person is infected with millions of different versions, each one appearing different to the immune system.

In addition, the virus infects the very immune cells that are supposed to help protect the body. And if even one virus gets past the immune defense, it appears to set up a lifelong infection. No drug has been able to eradicate it.

IAVI director Dr. Seth Berkley said the findings will not lead directly to a vaccine, but show that there are new and better ways to design one.

He said 10 percent of the patients whose blood was screened had a strong antibody response to the virus. "We have people with even more potent serum out there. We will probably see more," he said in a telephone interview.

It may also be possible to use such antibodies as therapy themselves -- such as the gamma globulin used for hepatitis virus. But the eventual goal, Berkley said, is a vaccine that produces antibodies that could stop the virus from ever infecting a person in the first place.

"We haven't been able to do that because we haven't been able to find the right kind of response," Berkley said.

Most vaccines elicit an antibody response, priming the body to make antibodies that will recognize and attack an invader such as a bacteria or virus.

The two antibodies, called PG9 and PG16, are the first new HIV antibodies to have been identified in more than 10 years. They target a region of the spike the virus uses to infect cells, the researchers wrote.

A team at South San Francisco-based Monogram Biosciences Inc screened the blood for the ability to neutralize HIV. Theraclone Sciences used its technology to identify the antibodies involved.

North Carolina-based Laboratory Corp of America Holdings acquired Monogram in July.

Source: Reuters

Obesity Ages the Brain and Reduces Life Span

Overall, about two-thirds of adults in the U.S. are either overweight or obese and about 6 percent are extremely obese, putting them at an increased risk for diabetes, hypertension, heart disease, osteoarthritis, stroke, gallbladder disease, sleep apnea, respiratory problems and even certain cancers. Researchers have also discovered that obesity increases the risk for dementia, and a new study detailed in the online edition of the journal Human Brain Mapping may help to explain why.

When researchers at UCLA and the University of Pittsburgh scanned the brains of 94 people in the 70s, they found that the obese individuals had 8 percent less brain tissue than their normal-weight peers, and their brains looked 16 years older than the brains of lean people—evidence of “severe brain degeneration,” according to study author Paul Thompson, a UCLA professor of neurology. Those classified as overweight had 4 percent less brain tissue and their brains appeared to have aged prematurely by eight years.

For obese people, the areas of significant shrinkage was in the frontal and temporal lobes, areas of the brain critical for reasoning and judgment; the anterior cingulate gyrus, key to attention and decision-making; the hippocampus, which processes long-term memories; and basal ganglia, from which movement is initiated. Overweight people showed shrinkage in the basal ganglia and the parietal lobe, where we integrate sensory input, and in the corona radiata, which helps speed messages among regions of the brain that must work together for proper functioning. 

While the participants of the study showed no outward signs of cognitive impairment at the time of the study, the researchers predicted that the premature aging and loss of brain volume will put the heavier subjects at greater risk of developing Alzheimer’s disease and other degenerative brain diseases. “That’s a big loss of tissue and it depletes your cognitive reserves, putting you at much greater risk of Alzheimer’s and other diseases that attack the brain,” Thompson said. 

Experts say people can greatly reduce their risk for Alzheimer’s and related diseases by exercising, eating healthily and keeping their weight under control. “A brain healthy diet is one that is heavy on fruits and nuts and low in fat and cholesterol,” says Lou-Ellen Barkan, president and CEO of the New York City chapter of the Alzheimer’s Association. “Obesity is definitely not a good thing for a healthy brain.”

But researchers say obesity isn’t just causing the brain to shrink—it is also trimming years off people’s lives. Economists at RTI International, a non-profit research organization in Research Triangle Park, N.C., analyzed data on 366,000 people and found that extremely obese people, those with a body mass index of 40 or greater, live three to 12 years less than their normal-weight peers. And extremely obese people who smoke live an average of 21 years less than non-smokers of normal weight. For instance, an 18-year-old white male who is of normal weight and does not smoke can expect to live to age 81, but if he’s extremely obese and a smoker, his life expectancy fall to 60. The researchers estimate that overall, Americans lost roughly 95 million years in 2008 by carrying around excess weight. 

However, the study found that just being overweight or moderately obese has little or no effect on life span. Non-smokers who are overweight—meaning they have a body mass index of 29 or less—do not have shortened lives, and non-smokers who are obese — those with a BMI of 30 to 39—lose about a year or less off their lives. Lead author Eric Finkelstein says that may be because there are effective treatments to manage many of the health problems that often stem from extra pounds, such as hypertension, high cholesterol and diabetes. For example, 10 of the top 25 most prescribed medications target the three aforementioned diseases. 

Findings of the RTI study are published online in the journal Obesity.

Hormone Therapy Could Be Risky for Some Prostate Cancer Patients

Prostate cancer is one of the most common cancers among men, affecting about one in six men in the United States. It is usually a very slow-growing disease, taking years to spread beyond the gland and pose a serious health threat. Once the cancer has spread beyond the prostate gland it can no longer be cured, but it can be slowed down by injecting the patient with drugs that block the supply of testosterone, a male hormone that directly stimulates the growth of both normal prostate tissue and prostate cancer cells. The treatment, known as hormone therapy or HT, can increase survival in more advanced cases of prostate cancer when used with surgery or radiation. But the side effects are unpleasant: hot flashes, erectile dysfunction, bone loss, memory problems, fatigue and loss of interest in sex. And, according to a new study, it may be dangerous for some men with heart disease—doubling their risk of death.

Dr. Anthony D’Amico of Brigham and Women’s Hospital and the Dana-Farber Cancer Institute in Boston and colleagues studied 5,077 cases of men, average of about 70, diagnosed with localized or locally advanced prostate cancer between 1997 and 2006. All the men were treated with radiation therapy and 30 percent of them also took HT for an average of four months. Over a median follow-up of five years, 419 of the men died. Of those, 200 had no underlying cardiac conditions or risk factors, 176 had one coronary artery disease factor, such as high blood cholesterol, and 43 had suffered from heart failure or had a heart attack.

Analysis of the data showed that, when considering comorbidity groups separately, HT caused no increased risk of all-cause mortality in men with no co-existing conditions (9.6 percent vs. 6.7 percent) or those with a single coronary artery disease risk factor (10.7 percent vs. 7.0 percent). However, for those with a history of serious heart problems, HT was associated with nearly twice the risk of all-cause mortality (26.3 percent vs. 11.2 percent). “Our results should heighten awareness about the potential for harm with hormonal therapy for men with pre-existing heart disease,” said study author Dr. Akash Nanda of the Harvard Radiation Oncology Program in Boston. “The risks need to be balanced with the benefits. For more advanced disease, the primary treatment is a combination of hormone therapy and radiation. So, for them, it becomes a little more tricky.” 

Some experts agree that co-existing heart conditions should be taken into account when deciding which treatment best suits a patient. “I think this is going to make people even more conservative in their use of hormones than when researchers started to identify who benefited,” said Dr. Eric M. Horwitz, acting chairman of the radiation oncology department at Fox Chase Cancer Center in Philadelphia. “We had always thought that there might be cardiac problems with long-term use of hormones, but this shows that even a short course can be harmful.”

For other experts, the findings weren’t unexpected. “For those who’ve been following the field, this is not surprising at all,” said Dr. Stephen Freedland, a Duke University prostate cancer specialist. He said that although some patients benefit from hormone therapy, it’s dangerous in the wrong patients—increasing insulin resistance, raising cholesterol, and increasing fat—likening it to the opposite of performance-enhancing drugs some athletes have taken. “You take away the muscles and give him fat,” Freedland said. 

The study is published in the Journal of the American Medical Association. 

Early Treatment off COPD May Increase Life Expectancy

reating chronic obstructive pulmonary disease (COPD) during early stages may slow the progression of the disease, and allow those who suffer from the illness to live longer and suffer less. New research on a promising  anti-inflammatory drug, as well as a study on an already well-known anticholinergic drug, offer renewed hope for those who have been diagnosed with COPD.

Now the fourth leading cause of death in the United States, COPD is a progressive disease that causes irreversible damage to the lungs and is most commonly caused by years of smoking. An estimated 24 million Americans suffer from COPD. Symptoms of the illness may include shortness of breath, a persistent cough, mucus production, wheezing, chest tightness, and tiredness.

In the first of three reports on COPD published in the August 29th issue of the journal The Lancet, patients who began early treatment with the inhaled drug Spiriva (tiotropium) experienced improved outcomes in comparison to patients who remained untreated. According to lead researcher Dr. Marc Decramer, a professor in the department of pathophysiology at University Hospital of the University of Leuven in Belgium, “If you treat moderate disease with these anticholinergic drugs, you get clear improvements in lung function, health-related quality of life, exacerbations and even, maybe, in mortality.” As for the improvement in mortality, Decramer said that although this was not found to be statistically significant, there was a trend observed. He also pointed out that the treatments “seem to reduce the rate at which the disease progresses.”

Decramer and colleagues monitored 2,376 early stage COPD patients who were randomly assigned to receive Spiriva or a placebo. After following the progress of the participants for four years, the researchers found the rate of decline in lung function to be 12 percent lower among the recipients of Spiriva compared to those who received the placebo. In addition, patients taking Spiriva had 18 percent less flare-ups of their COPD, leading to a reduction of 26 percent in hospitalizations due to flare-ups. Decramer explained that it is highly important that COPD be diagnosed in the early stages, and that aggressive treatment begins upon diagnosis to attain the best possible outcomes.

The remaining two reports in The Lancet established the benefits of the new anti-inflammatory drug called Daxas (roflumilast) in the treatment of COPD. The drug is still undergoing the approval process of the U.S. Food and Drug Administration (FDA).

In the first study, Dr. Leonardo Fabbri of the University of Modena in Italy and his team followed 3,091 patients who suffered from severe COPD after randomly assigning then to receive either Daxas or a placebo. After monitoring the patients for one year, findings revealed that those patients taking Daxas gained improved lung function and experienced 17 percent less flare-ups of their COPD than did patients taking the placebo. In their report, the researchers conclude, “These results suggest that different subsets of patients exist within the broad range of COPD, and that targeted specific therapies could improve disease management.”

Dr. Klaus F. Rabe, of Leiden University Medical Center in the Netherlands led the second study in which Daxas was used in addition to the standard COPD treatments with long-acting bronchodilators or anticholinergics. A total of 1,677 patients having moderate-to-severe COPD took either Daxas or a placebo for a 24-week period. Those patients who were randomly assigned to receive Daxas also received the bronchodilator Serevent (salmeterol) or Spiriva. The results showed that patients who took Daxas with either Serevent or Spiriva experienced a greater improvement in lung function than they would have by taking Serevent or Spiriva alone.

A decrease in respiratory symptoms was another benefit observed in patients who were treated for COPD with Daxas. However, in both trials, patients taking Daxas experience side effects including nausea, diarrhea and weight loss.

The researchers concluded, “Roflumilast improves lung function in patients with moderate-to-severe COPD who are already being treated with long-acting bronchodilators [or anticholinergic drugs], although with expected class-specific adverse events. Roflumilast could become an important, concomitant treatment for these patients.”
 

New “liquid condom” to protect women from transmitted diseases including HIV

The new “liquid condom” developed by the scientists will not only empower women by aiding in controlling their pregnancy without their partner’s permission it will also protect them from sexually transmitted diseases including HIV.

The new contraceptive gel can trap semen as well as any particles wider than 50 nanometres, which include the HIV, herpes and papilloma viruses.

The new "molecular condom" gel changes in response to changes in pH - acidity or alkalinity - in the vagina caused by the introduction of semen during sex.

It remains in liquid form while in contact with acidity levels normally found in the vagina but it turns into semisolid when it encounters semen which his alkaline, forming a mesh of "crosslinked" molecules.

Lead researcher, Patrick Kiser, and assistant professor at the University of Utah in Salt Lake City says that the chemical bonds between the two polymers constantly attach and detach at normal, acidic vaginal pHs of about 4.8, allowing the gel to flow. But at a pH of 7.6 - the slightly alkaline condition when semen enters the vagina - the PBA and SHA polymers "crosslink" and stick tightly together.