Azoospermia in rabbits following an intravas injection of Vasalgel ™

Background

Vasectomy is currently the only long-acting contraceptive option available for men, despite increasing demand and potentially significant positive impacts on human health of additional male contraceptive options. Vasalgel ? is a high molecular weight hydrogel polymer being developed as a non-hormonal long-acting reversible male contraceptive. Vasalgel consists of styrene-alt-maleic acid dissolved in dimethyl sulfoxide, which is distinct from styrene-alt-maleic anhydride materials previously studied.

Methods

The goal of the study was to determine the contraceptive efficacy of two test articles with different levels of styrene maleic acid (100 %, and 80 % acid/20 % anhydride). The test articles were injected bilaterally in the vasa deferentia of mature male rabbits. Post-implantation analyses of semen parameters were completed over a 12 month period and compared to baseline measures of sperm concentration, motility and forward progression.

Results

Both test articles were effective in blocking the passage of spermatozoa through the vasa deferentia in the 12 subjects completing the study. A significant decrease in sperm concentration occurred following implantation of the test material, with no measurable sperm concentration except for a few samples in one animal that were markedly oligospermic. Vasalgel produced a rapid onset of azoospermia, with no sperm in semen samples collected as early as 29–36 days post-implantation, and was durable over a 12 month period.

Conclusion

This study indicated that Vasalgel is an effective non-hormonal long-acting male contraceptive in a rabbit model.

     

135例无精症患者的细胞遗传学分析:附一例世界首报染色体异常核型 Cytogenetic Studies of 135 Cases with Azoospermia

本文对来我室咨询的135例无精症患者进行了细胞遗传学分析,发现异常核型38例,其中47.XXY,t(6;9)(p21;p22)为世界首报核型。本文对异常核型与无精症之间的关系进行探讨。 Abstract:Cytogenetic studies have been done on 135 cases with azoospermia,and 38 cases of abnormal karyotypes were discovered.Among which,one abnormal karyotype was the first reported in the world.It is 47,XXY,t(6;9)(p21;q22).The relationship between abnormal karyotypes and azoospermia is discussed.