African strain of Zika virus shown to act more quickly than Asian strain
March 20--Every two weeks, we gather some of the most interesting and intriguing studies from health researchers around the world. Here are the latest:
New research from the University of Missouri offers insight into how the Zika virus infects placental cells in pregnant mothers, often altering fetal development.
Zika virus is primarily spread by mosquitoes, and in 2016, it infected more than 1,500 pregnant women in the U.S., according to the Centers for Disease Control and Prevention. The University of Missouri study looked at two strains of the Zika virus -- the African strain as well as the Asian strain, the latter of which has been linked to a neurological defect called microcephaly in human babies.
Researchers used stem cells to create placental cells, and then infected two separate groups of those cells with the Asian or the African strain of the Zika virus, according to a news release about the study, which was published in the Proceedings of the National Academy of Sciences.
The Asian strain of the virus entered the cell and replicated within the cells, but did not kill the cells, according to the release.
"Our research suggests that the Asian strain infects the placenta in the early stages of pregnancy and essentially 'lies in wait' where it is then transmitted to the fetus causing neurological disorders in infants such as microcephaly," said Megan Sheridan, a graduate student who worked on the study, in a statement.
The African strain of the Zika virus, on the other hand, killed the placental cells in 40 to 48 hours, indicating that African strain of Zika could possibly cause abortions in infected mothers.
"African Zika, while less prevalent, could be much more deadly during early pregnancy," said Michael Roberts, lead author, in a statement. "The findings suggest that the developing fetus could be most vulnerable to infection by Zika virus and other pathogens during a relatively narrow window within the first trimester of pregnancy."
Placenta may reveal autism early
Two studies out of UC Davis this month suggest the placenta may reveal signs of autism spectrum disorder.
One study identified a region of the placenta where many of the genes underwent a structural change called methylation. Previous studies suggest an association between methylation and autism spectrum disorder.
The second study sought to investigate the causes of methylation in placental cells. Looking at 47 placentas from children with autism, researchers found that placentas of women who were exposed to professionally applied pesticides showed the most methylation. They also studied the women's smoking habits, maternal body mass index and vitamin intake.
"(The placenta) is thought to control differentiation versus proliferation in neurons, which happens to be one of the suspect areas in autism," said Rebecca Schmidt, co-author on the second paper, in a news release.
Researchers believe placental tissue, which is usually discarded at birth, could help diagnose autism and other conditions in the future.
"The placenta provides a time capsule of what the fetus was exposed to during pregnancy," said Janine LaSalle, principal investigator on both studies, in the release. "If we could assess (autism spectrum disorder) risk at birth, the early behavioral interventions with young, high-risk kids could really improve their quality of life."
Sammy Caiola: 916-321-1636, @SammyCaiola