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Amid an obesity epidemic, the approval of two new obesity drugs might revamp the clinical landscape of obesity treatment.

In June, the FDA approved lorcaserin (Belviq), a prescription weight-loss drug developed by Arena Pharmaceuticals that induces satiety through the activation of the 5HT2C receptor, a subtype of serotonin receptors found only in the brain. In 2010, the FDA had rejected lorcaserin because of evidence that it increased cancer incidence in rats and because its modest efficacy did not outweigh safety concerns. New data presented by the company changed the views of the FDA advisory panel, which concluded that the cancer findings did not apply to humans

The FDA's approval in July of Qsymia, developed by the small drug company Vivus, may signal a greater willingness of the FDA to tolerate certain side effects in an antiobesity drug. Qsymia is a combination of two older drugs, phentermine and topiramate, that reduces hunger by targeting different neurotransmitter systems, mainly norepinephrine but also dopamine and serotonin. Whereas this drug seems to induce more weight loss than lorcaserin in a similar target population (an average of 8.9% at the highest dose compared to placebo), it may cause more serious side effects, including an increased heart rate and increased risk of birth defects.

Antibiotics linked to fat buildup

Antibiotics may plump up cows, pigs, chickens, mice and humans alike, new research suggests.
For decades, low doses of antibiotics have been given to livestock to make the animals grow and bulk up faster, but no one really knew how the drugs promoted growth. Now, researchers led by microbiologist Martin Blaser at the New York University School of Medicine report online August 22 in Nature that antibiotics alter the mix of bacteria in the intestines of mice and cause the rodents to build up more fat than normal.
In a separate study, published online August 21 in the International Journal of Obesity, Blaser’s group found a link between antibiotic use in babies younger than 6 months old and being overweight at age 3. Together, the studies suggest that medications that alter the mix of friendly bacteria in the gut may have lasting effects on body weight.

Although antibiotics are meant to kill bacteria, the researchers found that the total number of bacteria in the mice’s guts didn’t change. But the mix of the microbes did. Mice on antibiotics had more of a type of bacteria called Firmicutes and fewer Bacteroidetes bacteria than did mice in the no-antibiotics group. That shift in the composition of gut bacteria is similar to the mix of microbes previously found in obese people, says study coauthor Ilseung Cho, a gastroenterologist at NYU.

Gut microbes in antibiotic-ingesting mice produced more short-chain fatty acids, a type of fat that cells use for energy. “Essentially you’re getting more fuel from the same amount of starting material,” Cho says.

Arctic sea ice set to hit record low within days

As Arctic summers go, 2012 is on track to be a record breaker. Both the sea ice and the Greenland ice sheet are shrinking to new lows this year.

We reported last week that the Arctic sea ice is melting more than any previous year on record. September 2007 currently holds the record for the lowest extent of Arctic sea ice, at least since satellite records began in 1979, and probably before. The melt made headlines that year, as it opened the fabled Northwest Passage - which runs north of Canada and Alaska.Researchers blamed a combination of long-term climate change and unusual weather patterns.

2007 has become the benchmark for low Arctic ice cover, until now. Ice extent is currently smaller than it was in late August 2007. Based on the latest data from the US National Snow & Ice Data Center in Boulder, Colorado, it could shrink below the 2007 minimum within days. There's another few weeks to go before the annual summer minimum is reached and cooling autumn temperatures allow the ice cap to grow back for the winter.

Greenland low, too

The ice sheet that sits on Greenland is also melting at a record pace. A new analysis of satellite data by Marco Tedesco of the City College of New York shows that it has already melted more than any summer since records began. The previous record year was 2010, but this year the ice sheet reached the 2010 minimum on 8 August.

The ice will bounce back once winter sets in, but the record lows are telling indicators that climate change is radically transforming the Arctic

Nutrient-boosted foods protect against blindness

THERE'S a new weapon in the battle against blindness, and it's bright orange. A sweet potato bred naturally to contain loads more beta carotene than its traditional counterparts has helped stave off vitamin A deficiency in thousands of Ugandans. The announcement comes as other results confirm that beta-carotene-packed genetically modified rice can also boost dietary vitamin A effectively. Beta carotene is converted into vitamin A in the body.

About half a million children in Africa and Asia go blind every year because their diet contains too little vitamin A, which is vital for vision and the immune system. Of those who lose their sight, two-thirds die within months.

see also: Editorial: "Nutrient-boosted Golden Rice should be embraced"

Court Blocks E.P.A. Rule on Cross-State Pollution by CO2, SO2, & NO

The agency was trying to address a problem that has vexed the air pollution control system for at least three decades: how to deal with states whose own air meets standards but whose power plants, refineries and other industrial plants emit sulfur dioxide and nitrogen oxide pollutants that — wind-aided — prevent neighboring states from attaining the level of cleanliness required under federal law.

In a 2-to-1 ruling, a panel of the United States Court of Appeals for the District of Columbia said the E.P.A. had exceeded its authority in the way it apportioned the cleanup work among 28 upwind states.