Et Cetera

Postmenopausal women often get osteoporosis, a weakening of the bones that can lead to easy fracture. A report in Science may explain why. A drop-off in the hormone estrogen leads to an overproduction of osteoclasts, cells whose job is to scour away aging bone cells. Trouble is, other cells called osteoblasts, which fill in the holes left by osteoclasts, don't increase proportionately. If humans respond the same way as lab mice, new drugs could supersede current estrogen-replacement therapy, which can cause fluid retention and leg cramps.