Lab study supports idea of ‘cytokine storm’ in H5N1 flu

first_img See also: Nov 16, 2005 (CIDRAP News) – A recent laboratory study has produced more evidence that infection of human lung cells with the H5N1 avian influenza virus leads to intense inflammation similar to what was seen in victims of the 1918 Spanish flu pandemic. The H5N1 viruses were “more potent inducers” of cytokines and chemokines—chemical messengers that trigger inflammation—than H1N1 viruses were, says the report by a team led by J.S.M. Peiris of the University of Hong Kong. A flood of inflammation-triggering chemicals released by the immune systems has been referred to as a “cytokine storm.” Autopsies of H5N1 avian flu victims in Vietnam and elsewhere have revealed lungs choked with debris from the excessive inflammation triggered by the virus. Similar severe lung damage was frequently reported in victims of the 1918 pandemic, which disproportionately killed people with the strongest immune systems—young, healthy adults. The Hong Kong researchers sought to test their hypothesis that the H5N1 virus’s ability to trigger a flood of cytokines may contribute to the unusually severe disease it causes in humans. They used H5N1 viruses isolated from a patient who died of the infection in Hong Kong in 1997 and from two Vietnamese patients who were infected in 2004, plus an ordinary H1N1 virus isolated in Hong Kong in 1998. Chan MCW, Cheung CY, Chui WH, et al. Proinflamatory cytokine responses induced by influenza A(H5N1) viruses in primary human alveolar and bronchial epithelial cells. Respir Res 2005 (published online Nov 11) [Abstract] Laboratory cultures of human alveolar cells and bronchial epithelial cells were exposed to these viruses. Using real-time polymerase chain reaction (RT-PCR), the researchers assessed the levels of various cytokines and chemokines at several time intervals after infection. “We have found that infection with H5N1 viruses led to the production of 10 times higher levels of cytokines from human cells than normal human flu viruses,” said Peiris, as quoted Nov 12 in The Standard, a Chinese business newspaper.center_img Researchers from Hong Kong report that lung cells growing in a laboratory responded much more intensely to the H5N1 virus than to an ordinary flu virus, even though the viruses reproduced at about the same rate, according to the report published online by Respiratory Research. They found that all the H5N1 viruses caused cells to secrete significantly higher levels of IP-10 (interferon-gamma-inducible protein 10), interferon beta, a type of T cell known as RANTES, and interleukin-6 than the H1N1 virus did. In addition, the 2004 versions of H5N1 caused cells to release more IP-10 at 6 hours than the 1997 version did. Oct 11 CIDRAP News story “Experts cite differences between H5N1 and ordinary flu” The different cytokine responses are not explained by different viral growth rates, because all three virus subtypes replicated with similar efficiency, the article says. “The cellular mechanisms underlying this differential cytokine hyper-induction by H5N1 viruses are presently poorly understood,” it states. The report says previous research has shown that patients with H5N1 disease have higher levels of IP-10 and other chemokines in their blood than do people infected with ordinary flu, a finding that parallels the present laboratory findings. In addition, the article says that studies of recombinant flu viruses carrying genes from the 1918 pandemic virus showed that the recombinant viruses were highly lethal and induced high levels of macrophage-derived chemokines in mice. However, it is not yet clear whether the increased chemokine levels were due to “hyper-induction” of the chemokines or just rapid growth of the virus.last_img read more

Perfect answers ‘minor labor law’ challenges

first_imgIndianapolis, In. — Legislation recently introduced by Indiana state senator Chip Perfect has unintentionally ignited a firestorm of negative coverage.Perfect, owner of Perfect North Slopes, employs about 400 minors, Holiday World employs about 600 minors. Because of this, they have invested a substantial amount of business capital to develop systems to ensure they pass state labor inspections. He says the cost of the investment is justified by properly employing minors and avoiding violations of the law.Perfect says, “We’re a citizen legislature that means we rely on the people that are the most “expert” in a particular subject to carry the legislation and carry it to the other members.”The goal of this legislation is to rewrite statutes codified in the 1930s up to date and make complying with labor laws for small businesses more manageable.Publications like the Indianapolis Star and Washington Post jumped on Perfect to point out a conflict of interest, despite exoneration from his colleagues. Curiously, just before the bill was heard in committee, members of the newspaper industry requested to be amended into a bill that would recognize their delivery personnel as independent contractors, similar designations given to people who participate in direct sales.The bill is likely headed to Summer Study.last_img read more

Discount plant sale set at Prairie High School

first_imgPrairie High School is hosting a discount plant sale Friday and Saturday benefiting the high school horticulture program.Vegetables, flower pots and flower baskets are on sale at prices ranging from 75 cents to $15. Students grow tens of thousands of plants each year, some of which are used in school landscaping projects.The sale runs from 3:30 to 5:30 p.m. Friday and 9 a.m. to noon Saturday in Prairie High School’s greenhouse, located at 11311 N.E. 119th St., Vancouver.last_img