Chemical Liposuction and Tracking the Flu

A fat-reducing drug, Adipotide, that can reverse obesity in monkeys has been successfully tested by US scientists.

The agent, which was injected daily over a four week study period into a group of naturally obese baboons, macaques and rhesus primates, contains of a short string of amino acids that cause the drug to lock selectively onto the walls of blood vessels that supply adipose tissue. Linked to this short, blood vessel-targeting protein sequence is a further chemical signal that causes cells that are exposed to it to commit suicide. This it achieves by triggering structures called mitochondria, which are essential energy-generating components inside cells, to break down. In this way the agent causes the chemical equivalent of liposuction, culling fat cells and causing weight loss.

Compared control animals, the treated monkeys showed weight reductions of up to 14% and an average fat mass reduction of almost 40%. This translated into a body mass index (BMI) reduction of up to 20% and, just as overweight humans develop an insulin-resistant state that often leads to diabetes, the treated animals showed significantly lower insulin levels afterwards.

Surprisingly, the treated animals showed no signs of altered blood cholesterol or fatty acid levels while receiving the new agent, and there were no obvious behavioural side effects or evidence of altered eating behaviours during the study. The only thing that was picked up during the trial was a trend towards increased urine output and dehydration in animals receiving higher doses of the drug, although the relevance of this finding remains to be shown. The results offer a promising lead in the development of treatments to combat global obesity, which now affects up to one in five adults in many developed countries and carries a cancer risk elevation equivalent to being a regular smoker.

According to co-author Renata Pasqualini, "Development of this compound for human use would provide a non-surgical way to actually reduce accumulated white fat, in contrast to current weight-loss drugs that attempt to control appetite or prevent absorption of dietary fat." The team are now about to commence a human clinical trial involving a 28-day administration of the agent to patients with prostate cancer to determine whether their disease improves alongside the ensuing weight loss.

Two gas clouds containing pristine samples of the gas spawned by the Big Bang has been spotted by astronomers.

Using the powerful, Hawaii-based Keck I telescope, University of California Santa Cruz graduate student Michele Fumagalli and his colleagues focused on two distant quasars, called J1134+5742 and Q0956+122. Quasars are intense light sources produced by superheated matter falling into massive black holes at the centres of galaxies. To reach Earth, the light from them has to pass through any clouds of gas that are in their paths.

By looking at the light that arrives, researchers can work out what is in the gas because different chemical elements absorb discrete wavelengths of light, producing a unique chemical fingerprint. But prior to now all of the gas clouds that have ever been reported have always shown signs of significant contamination with metals. These can only have come from early stars, which produce heavier elements by fusing lighter substances, like hydrogen, together.

This means that the compositions of these contaminated gas clouds cannot be relied upon to test theories about the Big Bang, and the sorts of elements and in what ratios, it produced. Current models of the Big Bang suggest that, after about 8 minutes, the newborn Universe cooled from a sizzling one billion Kelvin to about 500 million Kelvin, which is hot enough for new elements to be born and yet cool enough for them to be stable.

The result, theoreticians think, was a mixture comprising mainly hydrogen and its isotope deuterium, together with a bit of helium and a trace of lithium. Yet without some of the resulting gas to study, the model remained unsupported by experimental evidence.

But the new findings, which are published this week by the journal Science and reveal gas clouds that date back to about 2 billion years after the Big Bang and are devoid of any metal contamination, change all that.

"The lack of metals tell us this gas is pristine," says Fumagalli. "It's quite exciting because it's the first evidence that fully matches the composition of the primordial gas predicted by the Big Bang theory."

Apart from validating existing hypotheses, the new findings also shed light on how the early galaxies were forming. Theoretical models predict that these nascent galaxies were growing by pulling in massive streams of cold gas, but these "cold flows" as they are known, have never been seen. Fumagalli is speculating that the pristine clouds he has spotted might just be them...