The study results were presented as a poster at the American Academy of Dermatology ACADEMY 2004 meeting in New York. The results of this study suggest that continuous, weekly dosing of RAPTIVA provided sustained clinical benefit over 2 1/2 years.
Of the 159 subjects participating in the study who completed 30 months of treatment, a 75 percent or greater improvement on the Psoriasis Area Severity Index (PASI 75) was observed in 78 percent (124/159) of patients with weekly RAPTIVA therapy. Ninety-one percent (145/159) of patients achieved a PASI 50 response, and 45 percent of patients (71/159) achieved a 90 percent or greater PASI improvement (PASI 90).
"Given that psoriasis is a chronic condition, dermatologists are looking for treatment options that can provide these patients with continuous control of their disease over the long-term," said Craig Leonardi, M.D., associate clinical professor of dermatology at St. Louis University Medical School, St. Louis, Mo., and a study investigator. "These data represent the first 30-month data available for any advanced therapy for plaque psoriasis and support the continued use of RAPTIVA as an important treatment option for patients afflicted with this chronic disease."
gene
Most of the primates they examined showed evidence of what is known as positive selection, indicating that the gene has been under pressure to evolve throughout history. But lentiviruses ” the family of viruses to which HIV belongs ” have been found in only some of the primates studied and appear to be at most 1 million years old.
"What is novel about our findings is that scientists tend to study evolution of viruses but not the host proteins that work against them," said lead author Sara Sawyer, Ph.D., a postdoctoral-research fellow in Malik's lab.
"Based on how rapidly HIV changes, we assumed that we could learn something by focusing on Apobec3G," she said.
Sawyer and colleagues propose that Apobec3G's original enemy is a family of virus-like invaders of the genome called retrotransposons. Known as mobile genetic elements, these snippets of DNA are thought to be relics of ancient viral infections that insert themselves into many places in the genome, regardless of whether they may disrupt the genes that inhabit those locations. HIV and other lentiviruses are similar to these ancient genetic attackers in that they also insert themselves into the host genome after infection.
The researchers conducted a similar analysis of other mutation-inducing proteins closely related to Apobec3G and found that some of them also show signs of evolutionary pressure. These too may have arisen to defend the host genome against mobile genetic elements and may now play a role in defending against as-yet-unknown viruses.
Malik said that there is a good lesson to be learned from his lab's research approach.
"If you study what most people consider harmless oddities of the genome and host defenses against them, you may uncover some very interesting aspects of human disease."
The research was supported by funds from Fred Hutchinson Cancer Research Center and the National Institutes of Health.
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