Word: sperm
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...biological functions: the ability to reproduce. The chemicals allegedly disrupt the action of hormones, those all-important molecular messengers that regulate just about all bodily activities, including growth and reproduction. The result may be a variety of harmful effects that could decrease fertility. Among them: testicular cancer and reduced sperm counts in men, uterine abnormalities and miscarriages in women. While there is no hard evidence that pollution is affecting human fertility in the U.S. or anywhere else, the theory is likely to grab the attention of millions of couples who have trouble conceiving...
...simply by breathing, drinking and especially eating. Some of the suspect chemicals have physiological effects similar to those of estrogen and other sex hormones, or they at least interact with them; they might reasonably be expected to interfere with processes involving these hormones, such as the menstrual cycle and sperm production...
Finally, several hormone-related human disorders, including low sperm counts, testicular and breast cancers and endometriosis (a painful condition in which uterine cells migrate to other parts of the pelvic area), have arguably been on the rise in the decades since DDT, dioxin and the like first entered the food chain. Says Thomas Burke of the Johns Hopkins School of Public Health: "What we have now is identification of a potential hazard, and that's all we have. What the implications are we don't know yet, and we need to clarify that...
...copies of adults by taking genetic information from, say, a skin cell and placing it in a fertilized egg stripped of its own DNA. But cloning like that performed by the George Washington doctors would be allowed. Because the eggs they used had been fertilized by more than one sperm, the embryos were destined to die within a few days anyway...
While treading cautiously in many areas, the NIH panel is supportive of several innovative lines of research. For example, biologists have learned how to trick unfertilized animal eggs into developing as if they had been fertilized. Without the sperm's DNA, however, these so-called parthenotes quickly perish. One tentative NIH proposal would allow scientists to produce parthenotes from human eggs. Such experiments could yield information on how embryonic cells influence each other's growth...