A joint Japanese-U.S. medical research team has developed a new method for detecting malfunctioning sperm that may be contributing to male infertility problems.
The team, led by Yukihiro Terada, assistant professor of obstetrics and gynecology at Tohoku University in Sendai, and Gerald Schatten, a research scientist at Oregon Health Sciences University in Portland, Ore., released the findings in an article published in Human Reproduction, the journal of the European Society of Human Reproduction and Embryology.
While still in its research phase, the new method developed by the team is expected to cast a spotlight on the causes of male infertility -- a side of the fertility equation that has long been ignored compared with female infertility.
If applied, the method may lessen the need for unnecessary and expensive tests and treatments on women, scientists say.
The method makes use of the protein ubiquitin, a catalyst involved in the degradation of proteins for which the human body has no use. The Terada-Schatten team found that an infertile sperm tends to have a large formation of ubiquitin on its surface compared with healthier sperm.
From that observation, the research team developed an infertility detection method using an antibody that combines exclusively with ubiquitin.
In infertility tests conducted at state-run Tohoku University Hospital on 17 male patients who complained of infertility, the research team found a large concentration of ubiquitin on the surface of sperm taken from 13 of them.
Previous infertility tests conducted on eight of those 13 through conventional methods proved inconclusive, the article says.