Fujita Y.,Womens Clinic OoizumiGakuen |
Shimada M.,Hiroshima University
Journal of Mammalian Ova Research | Year: 2014
The motility of frozen-thawed sperm is very different among not only species but also among individuals within the same species. Since the optimal protocol needs to be adjusted for each species produce good quality frozen sperm, we investigated the pretreatment, cooling, freezing and thawing methods of sperm cryopreservation. In the first part of sperm cryopreservation, we carried out either the isolation of sperm from human semen or the addition of a neutralizer to boar semen to protect the sperm from bacteria-released endotoxins. During the cooling and freezing processes, we determined the optimal combination of hyper-osmolality solution and low concentration of glycerol. Although the motility of the sperm immediately after thawing was very high after this novel freezing technique, the motility decreased in a time dependent manner due to the increase of intracellular Ca2+ in sperm. To suppress Ca2+ uptake just after thawing, we added the Ca2+chelator, EGTA to the sperm thawing media, which improved the post-thawed sperm motility and sperm membrane integrity, and decreased the rate of sperm DNA fragmentation. Using the frozen-thawed boar sperm, the conception rate and the number of pups per delivery were significantly greater than those of the conventional method. This method should contribute to human infertility care.
Negishi H.,Women's Clinic Ooizumigakuen |
Nakao K.,Women's Clinic Ooizumigakuen |
Kimura M.,Saitama Medical College |
Takenaka H.,Women's Clinic Ooizumigakuen |
Horikawa M.,Women's Clinic Ooizumigakuen
Reproductive Medicine and Biology | Year: 2015
Purpose: To determine the prevalence of insulin resistance (IR) and impaired glucose tolerance (IGT) in PCOS patients, the optimal screening method, and to compare our findings between nonobese and obese Japanese women with PCOS. Methods: Ninety-eight PCOS patients were included in this research from 2006 to 2013. Glucose tolerance test (OGTT) was performed. Serum glucose and insulin concentration were assayed before and 30, 60, and 120 min after taking 75 g of glucose. Results: All examined metabolic parameters were significantly favorable in the nonobese subjects, below 25 kg/m2. HOMA-IR, fasting insulin, glucose120, and insulin120 showed strong correlations with BMI. A total of 1.4 % of nonobese women had IR based on fasting insulin or HOMA-IR. However, 15.5 % (11/71) of nonobese women had IR as determined by a continuous increase of serum insulin level in OGTT. In comparison, the prevalence of IR among the obese women ranged from 41 to 59 %. AUCglucose, glucose60, glucose120, and insulin120 in nonobese women with a continuous insulin increase were higher than those without such a continuous increase. Conclusions: All examined metabolic parameters were significantly correlated with BMI. As the presence of a continuous increase of insulin level reflects to some degree poorer glucose tolerance, delayed insulin secretion, and enhanced insulin response compared with non-continuous insulin increase, OGTT might not been excluded to determine IR and IGT for nonobese women with PCOS. © 2015, Japan Society for Reproductive Medicine.