Science and Medicine

Chemicals in Mother’s Blood Contribute to Child’s Obesity, Study Suggests



Babies whose mothers had relatively high levels of the chemical DDE in their blood were more likely to both grow rapidly during their first 6 months and to have a high body mass index (BMI) by 14 months, according to a team of scientists based in Barcelona, Spain. DDE, an endocrine disruptor, is a by-product of the pesticide DDT.

Published online October 5 ahead of print in the peer-reviewed journal Environmental Health Perspectives (EHP), the study examined data collected between 2004 and 2006 on a representative sample of 518 Spanish women in their first trimester of pregnancy. Among babies whose mothers were normal weight prepregnancy, those babies whose mothers had DDE levels in the top 75 percent of exposure were twice as likely to grow rapidly during their first 6 months as babies whose mothers had the lowest DDE levels. Infants in the top 50 percent of exposure were three times more likely to have high BMI scores at 14 months. The researchers did not observe an association between DDE and weight for babies of mothers who were overweight before pregnancy.

Two other human studies have shown an association between prenatal DDE exposure and obesity later in life.

“However, this analysis suggests, to our knowledge, for the first time, that fetal DDE exposure may promote rapid growth starting in the immediate postnatal period,” said lead author and epidemiologist Michelle A. Mendez, of the Centre for Research in Environmental Epidemiology, and her colleagues.

Laboratory studies have suggested that “exposure to chemicals with endocrine-disrupting properties might promote shifts in appetite regulation, but may also promote obesity through metabolic changes,” Mendez said.

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Adult Stem Cells That Do Not Age



Biomedical researchers at the University at Buffalo have engineered adult stem cells that scientists can grow continuously in culture. (Credit: Douglas Levere, University at Buffalo)

Biomedical researchers at the University at Buffalo have engineered adult stem cells that scientists can grow continuously in culture, a discovery that could speed development of cost-effective treatments for diseases including heart disease, diabetes, immune disorders and neurodegenerative diseases.

UB scientists created the new cell lines—named “MSC Universal”—by genetically altering mesenchymal stem cells, which are found in bone marrow and can differentiate into cell types including bone, cartilage, muscle, fat, and beta-pancreatic islet cells.

The researchers say the breakthrough overcomes a frustrating barrier to progress in the field of regenerative medicine: the difficulty of growing adult stem cells for clinical applications.

Because mesenchymal stem cells have a limited life span in laboratory cultures, scientists and doctors who use the cells in research and treatments must continuously obtain fresh samples from bone marrow donors, a process both expensive and time-consuming. In addition, mesenchymal stem cells from different donors can vary in performance.

The cells that UB researchers modified show no signs of aging in culture, but otherwise appear to function as regular mesenchymal stem cells do—including by conferring therapeutic benefits in an animal study of heart disease. Despite their propensity to proliferate in the laboratory, MSC-Universal cells did not form tumors in animal testing.

“Our stem cell research is application-driven,” says Techung Lee, PhD, UB associate professor of biochemistry and biomedical engineering in the School of Medicine and Biomedical Sciences and the School of Engineering and Applied Sciences, who led the project. “If you want to make stem cell therapies feasible, affordable and reproducible, we know you have to overcome a few hurdles. Part of the problem in our health care industry is that you have a treatment, but it often costs too much. In the case of stem cell treatments, isolating stem cells is very expensive. The cells we have engineered grow continuously in the laboratory, which brings down the price of treatments.”

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Researchers Find Evidence of Teeth Loss in Ancestor of Whales



Genomic record matches fossil record in the whales’ common ancestor, say UC Riverside biologists

RIVERSIDE, Calif.—In contrast to a toothed whale, which retains teeth that aid in capturing prey, a living baleen whale (blue whale, fin whale, humpback, bowhead) has lost its teeth and must sift zooplankton and small fish from ocean waters with baleen or whalebone, a sieve-like structure in the upper jaw that filters food from large mouthfuls of seawater.

Based on previous anatomical and fossil data studies, scientists have widely believed that both the origin of baleen and the loss of teeth occurred in the common ancestor of baleen whales about 25 million years ago. Genetic evidence for these, however, was lacking.

Now biologists at the University of California, Riverside provide the first genetic evidence for the loss of mineralized teeth in the common ancestor of baleen whales. This genomic record, they argue, is fully compatible with the available fossil record showing that the origin of baleen and the loss of teeth both occurred in the common ancestor of modern baleen whales.

“We show that the genetic toolkit for enamel production was inactivated in the common ancestor of baleen whales,” said Mark Springer, a professor of biology, who led the research. “The loss of teeth in baleen whales marks an important transition in the evolutionary history of mammals, with the origin of baleen laying the foundation for the evolution of the largest animals on Earth.”

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