- #1
Doug Huffman
Gold Member
- 807
- 111
Sleeping sickness traps Kazakh town in waking nightmare
Scientists are baffled by a mysterious illness that has sent hundreds of people into days-long slumbers
http://www.telegraph.co.uk/news/wor...ss-traps-Kazakh-town-in-waking-nightmare.html
ProMED is my first professional news source that I consult every morning after three vulgar news sources. I am an occasional contributor as an 'interested layman'.
http://www.promedmail.org/
Published Date: 2014-09-14 20:13:11
Subject: PRO/AH/EDR> Undiagnosed cerebral disease - Kazakhstan (03)
Archive Number: 20140914.2772224
https://en.wikipedia.org/wiki/Encephalitis_lethargica
http://www.ninds.nih.gov/disorders/encephalitis_lethargica/encephalitis_lethargica.htm
The relationship between encephalitis lethargica and influenza: A critical analysis
Conclusions
It is frustrating that after almost a century of effort, we know very little about the etiology of
EL. Pertaining to the influenza hypothesis, it is invariably difficult to prove a negative case.
There are myriad technical limitations that potentially could cause experimental false
negatives. Contemporary morgues were not refrigerated so autolysis likely caused viral
degradation, after which brain is notoriously difficult to fix, and formalin fixation is suboptimal
for molecular studies. A 1-day delay of formalin fixation reduces measurable mRNA 99% and
the ratio between measured quantities of different genes could vary over 10-fold. This effect
is most pronounced for large amplicons; reducing the amplicon from 497 to 136 bp increased
quantifiable mRNA 100-fold (Abrahamsen et al, 2003; Smolinski et al, 2005). Additionally,
there is the difficulty of lysate processing from formalin-fixed, paraffin-embedded tissue and
the common problem of PCR inhibitors. All of these factors may adversely affect sensitivity.
Furthermore, cellular housekeeping mRNAs may be more plentiful and therefore statistically
more likely to survive postmortem degradation in amplifiable lengths than influenza RNA.
This effect might lower the power of negative RT-PCR studies such as those of McCall et al
and Lo et al. Most available cases had clinical courses long enough before their death that an
acute viral infection might no longer be detectable.
Influenza causation might provide a convenient explanation for EL’s disappearance because
the 1918-like influenza strains ceased human circulation sometime before 1933 when the first
human strain was cultured (Taubenberger, 2006). Empirical studies provide little evidence of
influenza causation; but, as we have demonstrated, technical limitations and the shortage of
appropriate material for testing limit the degree of confidence. Therefore, unless another cause
of classical EL is positively identified, its return in the context of another influenza pandemic
remains formally possible. Such a recurrence would provide an opportunity to establish the
etiology of EL using modern methods.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2778472/pdf/nihms156516.pdf
Scientists are baffled by a mysterious illness that has sent hundreds of people into days-long slumbers
http://www.telegraph.co.uk/news/wor...ss-traps-Kazakh-town-in-waking-nightmare.html
ProMED is my first professional news source that I consult every morning after three vulgar news sources. I am an occasional contributor as an 'interested layman'.
http://www.promedmail.org/
Published Date: 2014-09-14 20:13:11
Subject: PRO/AH/EDR> Undiagnosed cerebral disease - Kazakhstan (03)
Archive Number: 20140914.2772224
https://en.wikipedia.org/wiki/Encephalitis_lethargica
http://www.ninds.nih.gov/disorders/encephalitis_lethargica/encephalitis_lethargica.htm
The relationship between encephalitis lethargica and influenza: A critical analysis
Conclusions
It is frustrating that after almost a century of effort, we know very little about the etiology of
EL. Pertaining to the influenza hypothesis, it is invariably difficult to prove a negative case.
There are myriad technical limitations that potentially could cause experimental false
negatives. Contemporary morgues were not refrigerated so autolysis likely caused viral
degradation, after which brain is notoriously difficult to fix, and formalin fixation is suboptimal
for molecular studies. A 1-day delay of formalin fixation reduces measurable mRNA 99% and
the ratio between measured quantities of different genes could vary over 10-fold. This effect
is most pronounced for large amplicons; reducing the amplicon from 497 to 136 bp increased
quantifiable mRNA 100-fold (Abrahamsen et al, 2003; Smolinski et al, 2005). Additionally,
there is the difficulty of lysate processing from formalin-fixed, paraffin-embedded tissue and
the common problem of PCR inhibitors. All of these factors may adversely affect sensitivity.
Furthermore, cellular housekeeping mRNAs may be more plentiful and therefore statistically
more likely to survive postmortem degradation in amplifiable lengths than influenza RNA.
This effect might lower the power of negative RT-PCR studies such as those of McCall et al
and Lo et al. Most available cases had clinical courses long enough before their death that an
acute viral infection might no longer be detectable.
Influenza causation might provide a convenient explanation for EL’s disappearance because
the 1918-like influenza strains ceased human circulation sometime before 1933 when the first
human strain was cultured (Taubenberger, 2006). Empirical studies provide little evidence of
influenza causation; but, as we have demonstrated, technical limitations and the shortage of
appropriate material for testing limit the degree of confidence. Therefore, unless another cause
of classical EL is positively identified, its return in the context of another influenza pandemic
remains formally possible. Such a recurrence would provide an opportunity to establish the
etiology of EL using modern methods.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2778472/pdf/nihms156516.pdf
Last edited:
