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Virus and bioinformatics articles with some microbiology and immunology thrown in for good measure
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Effect of Formaldehyde Inactivation on Poliovirus

Inactivated polio vaccines, which have been used in many countries for more than 50 years, are produced by treating live poliovirus (PV) with formaldehyde. However, the molecular mechanisms underlying virus inactivation are not well understood. Infection by PV is initiated by virus binding to specific cell receptors, which results in viral particles undergoing sequential conformational changes that generate altered structural forms (135S and 80S particles) and leads to virus cell entry. We have analyzed the ability of inactivated PV to bind to the human poliovirus receptor (hPVR) using various techniques such as ultracentrifugation, fluorescence-activated cell sorting flow cytometry and real-time reverse transcription-PCR (RT-PCR). The results showed that although retaining the ability to bind to hPVR, inactivated PV bound less efficiently in comparison to live PV. We also found that inactivated PV showed resistance to structural conversion in vitro, as judged by measuring changes in antigenicity, the ability to bind to hPVR, and viral RNA release at high temperature. Furthermore, viral RNA from inactivated PV was shown to be modified, since cDNA yields obtained by RT-PCR amplification were severely reduced and no infectious virus was recovered after RNA transfection into susceptible cells.

 

Ed Rybicki's insight:

People have been treating poliovirus with formaldehyde for over 60 years - and it's only NOW that someone thought to study in detail what happens!

 

I love this stuff: analytical centrifugation could have been done any time in the last fifty years (and has been, in determining structural transitions) but the newer techniques such as flow cytometry and RT-PCR could not. Analytically determining now what was empirically observed to work when polio vaccines were first made, is a historically important vindication of pioneering work that has almost made the viruses go away.

 

Simple and obvious findings, essentially - it is obvious that methylene bridging between amino acids would affect structural transitions; so too that HCHO treatment would kill viral ssRNA - but it hadn't been DONE properly previously.  Great stuff!

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World Polio Day

World Polio Day | Virology and Bioinformatics from Virology.ca | Scoop.it
As a virologist who has worked on poliovirus since 1979, I would be remiss if I did not note that today, 24 October, is World Polio Day.

The polio eradication effort has made impressive progress towards eliminating polio from the planet. In 1988 it was estimated that there were a total of 350,000 cases of poliomyelitis (probably an underestimate); as of this writing there have been 301 cases in 2013, which is unfortunately already more than in all of 2012 (223). Some setbacks to the program include an outbreak in the Horn of Africa, the finding of wild poliovirus (but no paralytic cases) in Israel, and two suspected cases in Syria. Transmission of wild poliovirus has never been interrupted in three countries: Afghanistan, Nigeria, and Pakistan. The good news is that India remains polio-free, a remarkable achievement.

 


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Ed Rybicki's curator insight, October 25, 2013 2:55 AM

Thanks, Vincent!

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A Polio Outbreak In Pakistan Reveals Gaps In Vaccination : NPR

A Polio Outbreak In Pakistan Reveals Gaps In Vaccination : NPR | Virology and Bioinformatics from Virology.ca | Scoop.it

Pakistan has made a lot of progress this year in wiping out polio. There are signs that one type of poliovirus is gone and transmission of other strains seems to be slowing.

 

But a recent outbreak of polio there has health officials concerned about the overall effectiveness of the effort to eliminate polio in that country. The World Health Organization says 10 cases of so-called vaccine-derived polio were reported in Pakistan between the end of August and the end of October.

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Griffin Safety's curator insight, May 6, 2014 12:42 AM

Sky News reports an increase in polio in Pakistan, Afghanistan and Nigeria.

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Why polio just became a global health crisis | Vaccinews Blog

Though only 650 cases were recorded last year, the World Health Organization declared the disease an emergency, but its importance goes beyond public health.
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Implications of finding poliovirus in sewers of Brazil and Israel

Implications of finding poliovirus in sewers of Brazil and Israel | Virology and Bioinformatics from Virology.ca | Scoop.it
Why has wild poliovirus been detected in the sewers of Brazil and Israel, and what are the implications for the eradication effort?

Via Ed Rybicki
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Ed Rybicki's curator insight, July 2, 2014 5:12 AM

Not unexpectedly, a calm and thorough analysis of the potential problem from the "virology blog"!

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Polio Eradication: The Bad News Continues | Wired Science | Wired.com

Polio Eradication: The Bad News Continues | Wired Science | Wired.com | Virology and Bioinformatics from Virology.ca | Scoop.it
When last we left the long asymptote of polio eradication, nine health workers in Pakistan who had been administering polio vaccine had been murdered,
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Intracellular Vesicle Acidification Promotes Maturation of Infectious Poliovirus Particles

Intracellular Vesicle Acidification Promotes Maturation of Infectious Poliovirus Particles | Virology and Bioinformatics from Virology.ca | Scoop.it
The autophagic pathway acts as part of the immune response against a variety of pathogens. However, several pathogens subvert autophagic signaling to promote their own replication. In many cases it has been demonstrated that these pathogens inhibit or delay the degradative aspect of autophagy.
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Polio Outbreak in China

Cases of polio have been reported in China, the country’s first cases in more than 10 years :-(


Via AJCann
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