Category: Health (page 19 of 27)

stem cells from urine?

These neural progenitor cells were generated by reprogramming cells from kidney tubules that were found in urine.

That’s not quite the best description of what this is. From Popular Science:

In their study, the researchers harvested kidney cells from the urine samples of three human donors and converted the cells directly to neural progenitors. Rather than using a genetically engineered virus to reprogram the cells, they used a small piece of bacterial DNA that can replicate in the cellular cytoplasm, a technique that eliminates the need to tamper directly with the chromosome (in theory, at least, this should reduce mutations) while also speeding up the entire process. After growing their progenitors into mature neurons and glial cells, the researchers transplanted the progenitors into the brains of newborn rats. A month later, the cells were still alive in the rats’ brains, though it is not yet clear that they can survive for extended periods or mesh with the brain’s wiring to become functioning parts of the neural machine.

There’s still a lot of research to be done on this method of course, but the researchers think it may provide a way to take cells gathered non-invasively and quickly and efficiently convert them into neural cells while reducing the likelihood of genetic mutations.

sperm count is falling

Illustration of sperm fertilizing an egg cell

A new French study finds sperm counts falling by about 2% each year over a 16 year period. From Popular Science:

A biggest-of-its-kind study suggests that sperm counts are falling. By a lot. Researchers studied French men from 1989 to 2005, measuring their sperm counts regularly, and found that counts fell about one third in that 16-year period, from 74 million per milliliter to about 50 million. A steady yearly decrease of about 2 percent took it that low.

For the study, out today in the journal Human Reproduction, researchers used a database of 126 fertility clinics in France, then took that data and narrowed it down to 26,600 samples from men unlikely to have existing infertility problems. Along with a major dip in sperm count, the study also found an increase in the amount of misshapen sperm (i.e. bad swimmers) in the men, who were 35 years old on average.

That’s a big dip, obviously, but it still falls in the normal sperm-count range–the World Health Organization puts that number at anything more than 15 million per milliliter. That doesn’t sound so bad, but the researchers argue that the 2-percent-decrease is cause enough for concern, and point out that any decrease can hurt men’s chances of conceiving children.

is carbonated water bad for you?

In a word:  no. But Monica Reinagel, answers this question and a few more related onese at Quick and Dirty tips.