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

If Dodgers keep winning, season could get historic in a hurry

first_imgLess believable, he said, “is more of the way everything worked out.”Wednesday’s 5-4 win over the Chicago White Sox was the 10th game the Dodgers have won in their final at-bat this season. The 10 game-winning RBIs have come from nine different players. (Trivia answer: Yasiel Puig, Kyle Farmer, Justin Turner, Cody Bellinger, Chris Taylor, Corey Seager, Logan Forsythe, Austin Barnes and Adrian Gonzalez.)The Dodgers have yet to lose a game they led after eight innings this season, but they have won eight times when trailing after eight.“It’s been a wild couple months, that’s for sure,” Bellinger said.What lies ahead could get historic in a hurry. The implications of an 85-34 record with six weeks left on the schedule are staggering. The websites FanGraphs.com and BaseballProspectus.com both project the Dodgers to finish the season 111-51. The franchise record for wins is 105, set in 1953 in Brooklyn. The Dodgers can go 21-22 to end the regular season and still break that record.This is the franchise’s 134th year of existence. Consider that the Dodgers have played more than 20,000 games since Year 1 – 1884 – and raised their winning percentage from .526 to .527 in less than five months.But how do the 2017 Dodgers compare to all major league teams, ever?The 1906 Chicago Cubs and 2001 Seattle Mariners share the all-time record of 116 regular-season wins. To equal that mark, the Dodgers must finish the season 31-12, a .721 clip that would require they slow down a bit. The Dodgers are 30-5 (.857) since July 4. The post-World War I record for highest winning percentage in a season (.721 by the 1954 Cleveland Indians) is also within reach.A team’s “magic number” is the minimum number of games that must be played in order to clinch a berth. The Dodgers’ magic number to clinch a playoff berth is 19. The Dodgers could seal their fate as early as Aug. 27, a home game against the Milwaukee Brewers.The Dodgers’ magic number to clinch the National League West is 24. The earliest they could clinch a division title is Aug. 30, a road game against the Arizona Diamondbacks.The New York Yankees established a modern record by clinching a playoff berth on Aug. 30, 1998. The Cincinnati Reds became the NL West champions on Sept. 7, 1975, the earliest a team has ever clinched a division title.For all the attention the Chicago Cubs garnered while ending their World Series drought last year, they did not clinch a playoff berth until Sept. 14. They won the NL Central the following day.Already, the Dodgers have a target on their backs, Manager Dave Roberts said.“When you’re an elite team and you look at what we’ve done, certainly every time they see us on the schedule they’re going to bring their best,” he said after Wednesday’s win. “Absolutely. I think our guys have set the bar for the league, and rightfully so.” LOS ANGELES >> Imagine going to spring training to watch the Dodgers, coming home, then going into a slumber for four months. You open your eyes in the middle of August and the Dodgers lead the National League West by 18 1/2 games. They can clinch their fifth straight division title before September and, by winning 32 of their final 43 games, break the all-time record for most wins in a season.Rob Segedin is not Rip Van Winkle, but his circumstances are illustrative. When injuries to his foot and wrist sent Segedin to the disabled list on April 19, the Dodgers were 8-8. They were 9-11 by April 24, the day before Cody Bellinger was recalled from Triple-A Oklahoma City. Since then they’ve gone 76-23; the Houston Astros have baseball’s second-best record during that time at 61-40.Segedin said he spent many a late night awake in Arizona, on rehab, watching the drama play out on TV.“I would’ve believed it,” Segedin said of the Dodgers’ record.center_img Newsroom GuidelinesNews TipsContact UsReport an Errorlast_img read more