FROM CNN SHILLS


Exposure to bisphenol-A (BPA), a controversial chemical found in hard, clear plastics, is thought to increase the risk of birth defects, early puberty, obesity, brain damage, and some forms of cancer.

Add another potential problem to the list: A new study of Chinese factory workers suggests that very high levels of BPA exposure may decrease sperm count and contribute to other sperm-related problems in men.

The findings aren't surprising. BPA—which can be found in some baby bottles and water bottles, as well the linings of food and beverage cans—is known to be a so-called endocrine disruptor that functions "like a weak estrogen" and blocks male sex hormones (including testosterone), says the lead author of the study, De-Kun Li, M.D., a reproductive and perinatal epidemiologist at Kaiser Permanente's division of research, in Oakland, California.

But the study is notable because it's one of the first in humans to link BPA with reproductive problems. Until very recently, most of the evidence implicating BPA in health problems has come from animal or laboratory studies. (BPA has been associated with reduced sperm count in mice and rats, for instance.)

"Human studies have been the missing link,"  Li says.

In the new study, which appears in the journal Fertility and Sterility, Li and his colleagues collected urine and semen samples from 218 factory workers, some of whom worked in facilities that make BPA or epoxy resin and were therefore regularly exposed to very high levels of the chemical.

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Research proves 'gender-bending' chemicals affect reproduction

October 26, 2010
New research has provided the first evidence that 'gender bending' chemicals which find their way from human products into rivers and oceans can have a significant impact on the ability of fish to breed in UK Rivers.

The findings from the four year study, led by the universities of Exeter and Brunel, has important implications for understanding the impacts of these chemicals on ecosystem health and possibly on humans.

Endocrine disrupting chemicals (EDCs) disrupt the ways that hormones work in the bodies of vertebrates (animals with backbones), including humans.
They can be found in everything from female contraceptive drugs and hormone replacement therapy pills, to washing up liquid, with the most well studied EDCs being those that mimic oestrogen (female hormone).

EDCs have been seeping into rivers through the sewage system for decades and have an observed effect on fish, altering male biology to make them more female – hence the 'gender bending' reputation of these chemicals.
Until now, there has been no solid evidence to show the long-term impact of this effect on fish in the wild - but the new research focusing on wild roach in two UK rivers (Bourne and Arun) has provided new evidence.

Two large-scale breeding studies assessed the ability of fish to breed by using a genetic technique (DNA microsatellites) to match offspring produced to their parents.
It was found that intersex fish – those that had their sexuality compromised by EDCs and which contain both male (sperm) and female (eggs) sex cells – had their reproductive performance reduced by up to 76%.

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An artificial ovary An engineered honeycomb of cultured theca cells (top row) envelopes spheres of granulosa cells (GC). The bottom row shows the tissue after 48 hours (left) and after five days. (Credit: Carson Lab / Brown University)


FROM SCIENCE DAILY

'Artificial Ovary' Develops Oocytes Into Mature Human Eggs ScienceDaily (Sep. 14, 2010) —

Researchers at Brown University and Women & Infants Hospital have invented the first artificial human ovary, an advance that provides a potentially powerful new means for conducting fertility research and could also yield infertility treatments for cancer patients. The team has already used the lab-grown organ to mature human eggs.

"An ovary is composed of three main cell types, and this is the first time that anyone has created a 3-D tissue structure with triple cell line," said Sandra Carson, professor of obstetrics and gynecology at the Warren Alpert Medical School of Brown University and director of the Division of Reproductive Endocrinology and Infertility at Women & Infants Hospital. Carson is a senior author of a recent article in the Journal of Assisted Reproduction and Genetics that describes the innovation.

Carson said that the ovary not only provides a living laboratory for investigating fundamental questions about how healthy ovaries work, but also can act as a testbed for seeing how problems, such as exposure to toxins or other chemicals, can disrupt egg maturation and health.

Clinically, the artificial ovary could play a role in preserving the fertility of women facing cancer treatment in the future, said Stephan Krotz, a Houston fertility doctor who is the paper's lead author and a former fellow in Carson's lab. Immature eggs could be salvaged and frozen before the onset of chemotherapy or radiation, he said, and then matured outside the patient in the artificial ovary.

Building an ovary

What makes the artificial ovary a functional tissue, rather than just a cell culture, is that it brings all three ovarian cell types into a 3-D arrangement similar to a real ovary in the body. The means for making such compositions of cells was invented in the lab of Jeffrey Morgan, associate professor of medical science and engineering, who is a co-author of the paper published online Aug. 25. His so-called 3D Petri dishes are made of a moldable agarose gel that provides a nurturing template to encourage cells to assemble into specific shapes.

To create the ovary, the researchers formed honeycombs of theca cells, one of two key types in the ovary, donated by reproductive-age (25-46) patients at the hospital. After the theca cells grew into the honeycomb shape, spherical clumps of donated granulosa cells were inserted into the holes of the honeycomb together with human egg cells, known as oocytes. In a couple days the theca cells enveloped the granulosa and eggs, mimicking a real ovary.

The big test, however, was whether the structure could function like an ovary -- namely to mature eggs. In experiments the structure was able to nurture eggs from the "early antral follicle" stage to full maturity.

"[This] represents the first success in using 3-D tissue engineering principles for in vitro oocyte maturation," the researchers wrote in the journal article.

Carson said her goal was never to invent an artificial organ, per se, but merely to create a research environment in which she could study how theca and granulosa cells and oocytes interact. When she learned of Morgan's 3-D Petri dishes, they began to collaborate on creating an organ. Morgan said this is the first fully functional tissue to be made using the method.

To help fund the work, Morgan and Carson applied for and won a Collaborative Research Award from the Rhode Island Science and Technology Advisory Council (STAC). STAC grants encourage research with commercial potential. Morgan has recently founded a local Rhode Island startup, MicroTissues Inc. The company will begin selling these micro-mold tools in about a month to researchers looking to engineer 3-D tissues. Other funding came from Women & Infants Hospital.


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