Word: profets
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...Profet arrived at her controversial theory by posing an age-old question: Why do women menstruate at all? As a means of disposing of unfertilized eggs and a plumped-up uterine lining, a monthly flow seems peculiarly wasteful. Women shed a great deal of blood and tissue, as well as valuable nutrients, particularly iron. "If menstruation were both costly and functionless," reasons Profet, "natural selection surely would have eliminated it long ago." Its persistence suggests that it offers some advantage...
What that advantage is, says Profet, came to her five years ago when she was awakened from a sound sleep one night by a neighbor's cat. "I'm in the middle of a dream," she recalls. "And I'm seeing those cartoons about menstruation, but now I'm seeing these black triangles in the endometrial lining, and I go, 'Whoa, those triangles are pathogens...
That dream evolved, after plenty of thought and research, into a full-blown thesis. Profet's reasoning begins with the observation that potentially harmful bacteria can catch a ride into the womb and Fallopian tubes by attaching themselves to sperm. The microbes can come from the male or get picked up in the vagina during sex. Menstruation eliminates the threatening intruders in two ways: the sloughed-off uterine lining carries the microbes off, and the blood itself is rich in immune cells ready to gobble up any alien invaders...
...what about women who are pregnant or have gone through menopause? Since they don't menstruate, how do they ward off bacteria? Profet notes that in the first six months of pregnancy and in some cases after menopause, the cervical entryway to the uterus is covered by a mucous plug. The mucus makes it hard for sperm -- and their nasty hitchhikers -- to enter the uterus, and thus reduces the need for a monthly blood flow. Profet suspects that doctors may be making a serious mistake by routinely regarding irregular bleeding as an endocrine problem to be stopped with hormone therapy...
...back her theory, Profet relies on electron-microscopy studies that show bacteria attached to the heads and tails of wriggling sperm. She also cites the existence of spiral-shaped arteries in the uterus. These specialized blood vessels constrict and dilate in a sequence timed to induce menstruation. And, she claims, the blood that washes over the uterine walls differs from blood that circulates throughout the rest of the body. Menstrual blood lacks ingredients that cause clotting and is rich in special immune cells called macrophages. Even so, says Debrovner, "there is no reason to believe that blood, no matter what...