December 31, 2010
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Just a couple papers to squeeze in this year before the clock strikes 12. I look forward to 2011 and the research it will bring in the Canadian realm. For those readers heading out tonight for some fun on the city, enjoy! More science reviews to come in the new year..
Porcine Adenovirus PAV3, A Novel and Promising Candidate for H5N1 Protection
National Microbiology Laboratory, Winnipeg ♦ Published in PLoS ONE, Dec. 16, 2010
Researchers have provided evidence that suggests a porcine adenovirus, PAV3, has greater vaccine efficacy than the human adenovirus AdHu5 in protecting against H5N1. An avian influenza H5N1 mouse model was used to compare immune response and protection following vaccination with the two different vectors. Mice that were vaccinated with a replication defective PAV3 vector carrying an H5N1 antigen expressed higher concentrations of neutralizing antibody post-vaccination and had stronger cellular immune responses than mice vaccinated with AdHu5. After challenging vaccinated mice with H5N1 infection, Dr. Gary Kobinger and his team demonstrated that mice inoculated with PAV3 showed higher overall survival. Another notable finding was that the porcine adenovirus did not become significantly neutralized when exposed to a pool of antibodies generated from 10,000 humans.
Study of Human Heart Microsomes Gives Insight into Cardiac CYP450s
University of Montreal ♦ Published in PLoS ONE, Dec. 14, 2010
Enzymes from the cytochrome P450 (CYP450) superfamily play an important role in drug metabolism. Variation in CYP450 isoforms can lead to inter-subject and inter-organ variability in drug metabolism, thus their study is crucial to understanding the metabolism of specific drugs. Dr. Jacques Turgeon and his colleagues at the University of Montreal gathered data on CYP450 mRNA levels in left and right ventricular samples taken from the explanted hearts of patients with end-stage heart failure. Samples were processed in the lab to extract microsomes, small vesicle-like structures composed of endoplasmic reticulum that contain large quantities of CYP450s. Among the interesting findings of this body of work is that CYP2J2 was the most abundant isoform found in cardiac tissue samples. Levels of CYP450 mRNA were similar across ischemic and non-ischemic samples and between left and right ventricles. Another principal and interesting finding was that the stereoselectivity of cardiac CYP450s was reversed compared to those in the liver. After exposing heart microsomes to the calcium channel blocker verapamil, higher levels of CYP450-dependent metabolites were observed in the presence of the R-enantiomer.
Ontario confirms 13 new cases as of Wednesday afternoon, bringing the total to 49 in the province, all considered mild. A lot of the public health messaging over the last 48 hours has been advising people not to relax too much.
Today also saw an interesting Canadian development on the scientific front. Although commentary around the different numbers of flu deaths in Mexico versus other areas has included the possibility that there are genetic variations in the virus, genetic differences do not appear to be responsible. Researchers at the National Microbiology Lab in Winnipeg sequenced Mexican and Canadian isolates and found no significant differences. According to Dr. Frank Plummer, the chief science adviser of the national lab:
“Essentially, what it appears to suggest, is that there is nothing at the genetic level that differentiates this virus that we got from Mexico and those from Nova Scotia and Ontario, that explains apparent differences in disease severity between Mexico and Canada and the United States.”
Also, speaking of not relaxing too much, the FDA just announced that they have approved a new Sanofi Pasteur vaccine manufacturing facility in Swiftwater, PA.
April 8, 2009
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Things that surprised me this week: