3 ms·

here's the paper I beleive they are referring to, http://www.biorxiv.org/content/biorxiv/early/2016/04/13/048538.full.pdf http://www.biorxiv.org/content/biorxiv

by tudorw 9y ago

here's the paper I beleive they are referring to, http://www.biorxiv.org/content/biorxiv/early/2016/04/13/048538.full.pdf http://www.biorxiv.org/content/biorxiv/early/2016/04/13/0485... "A Possible Link Between Pyriproxyfen and Microcephaly Dan Evans, Fred Nijhout† , Raphael Parens∗ , Alfredo J. Morales∗ and Yaneer Bar-Yam∗ ∗New England Complex Systems Institute, 210 Broadway Suite 101, Cambridge MA 02139, †Department of Biology, Duke University, Durham, NC 27708 (Dated: April 13, 2016) The Zika virus is the primary suspect in the large increase in microcephaly cases in 2015-6 in Brazil, however its role is unconfirmed despite individual cases of viral infections found in neural tissue. Here we consider the alternative that the insecticide pyriproxyfen, used in Brazilian drinking water for mosquito control, may actually be the cause. Pyriproxifen is an analog of juvenile hormone, which corresponds in mammals to regulatory molecules including retinoic acid, a vitamin A metabolite, with which it has cross-reactivity and whose application during development causes microcephaly. Methoprene, another juvenile hormone analog approved as an insecticide has metabolites that bind to the retinoid X receptor, and causes developmental disorders in mammals. Isotretinoin is another example of a retinoid causing microcephaly in human babies via activation of the retinoid X receptor. Moreover, tests of pyriproxyfen by the manufacturer, Sumitomo, widely quoted as giving no evidence for developmental toxicity, actually found some evidence for such an effect, including low brain mass and arhinencephaly—incomplete formation of the anterior cerebral hemispheres—in rat pups. Finally, the pyriproxyfen use in Brazil is unprecedented—it has never before been applied to a water supply on such a scale. Claims that it is not being used in Recife, the epicenter of microcephaly cases, do not distinguish the metropolitan area of Recife, where it is widely used, and the municipality, where it is not. Given this combination of information we strongly recommend that the use of pyriproxyfen in Brazil be suspended pending further investigation. "

tudorw 9y ago
I'm not sure about the credentials of the 'New England Complex Systems Institute', though the authors have written other papers. On the question of what pyriproxyfen does, I came across this, "Pyriproxyfen is a potent suppressor of embryogenesis and later development that competes for juvenile hormone receptor binding sites and disrupts the transition from one developmental stage to another [6]–[8]. The mode of action of pyriproxyfen is not fully understood due to the lack of a known signalling pathway and/or a receptor molecule. " from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275616/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275616/ So if this is still the case, people do not fully understand how pyriproxyfen does what it does, which is not that great.
- tudorw 9y ago
  "The WHO has congruently pointed to the use of insecticides – particularly larvicides – on sizeable containers of water to aid in mosquito eradication (87). Conversely and controversially, the Argentine-based group Physicians in the Crop-Sprayed Villages has implicated the larvicide known as pyriproxyfen as the source of the soaring rate of microcephaly in Brazil rather than 18 ZIKV itself (83). The report states that by quickly connecting microcephaly in newborns to the spread of ZIKV, the Brazilian Ministry of Health, PAHO, and WHO have put the commercial interests of the chemical industry above the well-being of the environment and the people, failing to identify that the areas where this larvicide has been introduced into drinking water are the same regions where microcephaly has exploded (81). The group supports their claims by affirming that no birth defects were found to be associated with previous ZIKV epidemics, and that in countries such as Colombia, there have been thousands of ZIKV cases but no documented instances of babies born with microcephaly (81). Based on previous examples of negligence in identifying the causes and scope of illnesses described in this analysis (AIDS and Lyme disease), there are evident hazards in allowing the supposed experts to dispose of a claim rather than investigating additional possibilities (55). However, in this situation, while it is still imperative to retain an open mind and not reject any factors that may play a role in the disorder – particularly when business and chemicals are involved – empirical findings suggest that ZIKV is likely the primary culprit in the upswing in microcephaly (83). " Nature's Games: Will the Global Medical Community Triumph Over Zika Virus? file:///F:/Chrome%20Downloads/eScholarship%20UC%20item%205n01487n.pdf
  - tudorw 9y ago
    https://www.nature.com/articles/srep40067 https://www.nature.com/articles/srep40067 04 January 2017 "Our data indicate that pyriproxyfen does not affect central nervous system development in zebrafish, suggesting that this larvicide on its own, may not be correlated with the increase in microcephaly cases reported recently."

by tudorw 9y ago

tudorw 9y ago

I'm not sure about the credentials of the 'New England Complex Systems Institute', though the authors have written other papers. On the question of what pyriproxyfen does, I came across this, "Pyriproxyfen is a potent suppressor of embryogenesis and later development that competes for juvenile hormone receptor binding sites and disrupts the transition from one developmental stage to another [6]–[8]. The mode of action of pyriproxyfen is not fully understood due to the lack of a known signalling pathway and/or a receptor molecule. " from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275616/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275616/ So if this is still the case, people do not fully understand how pyriproxyfen does what it does, which is not that great.

tudorw 9y ago
"The WHO has congruently pointed to the use of insecticides – particularly larvicides – on sizeable containers of water to aid in mosquito eradication (87). Conversely and controversially, the Argentine-based group Physicians in the Crop-Sprayed Villages has implicated the larvicide known as pyriproxyfen as the source of the soaring rate of microcephaly in Brazil rather than 18 ZIKV itself (83). The report states that by quickly connecting microcephaly in newborns to the spread of ZIKV, the Brazilian Ministry of Health, PAHO, and WHO have put the commercial interests of the chemical industry above the well-being of the environment and the people, failing to identify that the areas where this larvicide has been introduced into drinking water are the same regions where microcephaly has exploded (81). The group supports their claims by affirming that no birth defects were found to be associated with previous ZIKV epidemics, and that in countries such as Colombia, there have been thousands of ZIKV cases but no documented instances of babies born with microcephaly (81). Based on previous examples of negligence in identifying the causes and scope of illnesses described in this analysis (AIDS and Lyme disease), there are evident hazards in allowing the supposed experts to dispose of a claim rather than investigating additional possibilities (55). However, in this situation, while it is still imperative to retain an open mind and not reject any factors that may play a role in the disorder – particularly when business and chemicals are involved – empirical findings suggest that ZIKV is likely the primary culprit in the upswing in microcephaly (83). " Nature's Games: Will the Global Medical Community Triumph Over Zika Virus? file:///F:/Chrome%20Downloads/eScholarship%20UC%20item%205n01487n.pdf
- tudorw 9y ago
  https://www.nature.com/articles/srep40067 https://www.nature.com/articles/srep40067 04 January 2017 "Our data indicate that pyriproxyfen does not affect central nervous system development in zebrafish, suggesting that this larvicide on its own, may not be correlated with the increase in microcephaly cases reported recently."