New Frontline Drug For Influenza
The ghost of a drug-resistant form of the deadly H5N1 avian influenza is haunting the public health officials world over. But now, a study published recently in the Proceedings of the National Academy of Sciences (PNAS) suggests that a new compound, one on the threshold of final testing in humans, may be more potent and safer for treating “bird flu” than the antiviral drug best known by the trade name Tamiflu.
Known as T-705, the compound even works several days after infection, according to Yoshihiro Kawaoka, a University of Wisconsin-Madison virologist and the senior author of the new PNAS study.
“H5N1 virus is so pathogenic even Tamiflu doesn’t protect all the infected animals,” explains Kawaoka, a professor of pathobiological sciences at the UW-Madison School of Veterinary Medicine and a world authority on influenza. This compound works much better, even three days after infection, he said.
The Wisconsin research was conducted in mice and demonstrated that the compound was effective and safe against H5N1 virus, the highly pathogenic bird flu virus, which some scientists fear could spark a global epidemic of deadly influenza. The compound is also effective against seasonal flu and more worrisome varieties such as the H1N1 virus, and has already been tested against circulating seasonal influenza in humans in Japan where it is on the brink of Phase III clinical trials in people.
The prospect of a new front-line drug for influenza, in particular highly pathogenic strains such as H5N1 virus, is important as there are few drugs capable of checking the shifty influenza virus. The new study showing the efficacy and safety of T-705 assumes more importance as instances of Tamiflu-resistant strains of H5N1 virus have recently been reported, raising concerns about the ability of current antiviral drugs to blunt a pandemic of deadly avian flu.
POSITIVE EMOTIONAL EXPERIENCE
Exploding the previous notions that individuals with depression show less brain activity in areas associated with positive emotion, a new study at the University of Wisconsin-Madison suggests the similar initial levels of activity, but an inability to sustain them over time. The new work was reported online in the Proceedings of the National Academy of Sciences.
“Anhedonia, the inability to experience pleasure in things normally rewarding, is a cardinal symptom of depression,” explains UW-Madison graduate student Aaron Heller, who led the project. Scientists have generally thought that anhedonia is associated with a general reduction of activity in brain areas thought to be important for positive emotion and reward. In fact, Heller found that depressed patients showed normal levels of activity early on in the experiment. However, towards the end of the experiment, those levels of activity dropped off precipitously.
“Those depressed subjects who were better able to sustain activity in brain regions related to positive emotion and reward also reported higher levels of positive emotion in their everyday experience,” said Heller. “Being able to sustain and even enhance one’s own positive emotional experience is a critical component of health and well-being,” notes the study’s senior author, Richard Davidson, professor of psychology and psychiatry and director of both the UW-Madison Center for Investigating Healthy Minds, and the Waisman Laboratory for Brain Imaging and Behavior.