Sperm chromatin integrity in young men with no experiences of infertility and men from idiopathic infertility couples.

Damage to the genetic component of spermatozoa seems to play the main role in a majority of cases where current approaches fail to reveal the specific cause of male infertility. In this study, we compared semen quality in men assigned to two defined groups: men from couples with unexplained infertility - idiopathic infertility (A) and young men with no experiences of infertility (B). All samples were examined by standard ejaculate analysis and sperm chromatin structure assay (SCSA).

The role of p27(Kip1) in maintaining the levels of D-type cyclins in vivo.

This in vivo study employs p27-deficient mice to investigate the significance of p27 for the metabolism of D-type cyclins in differentiated cells. The absence of p27 results in decreased levels of cyclins D2 and/or D3 in some organs. As demonstrated on Leydig cells of testis, such dependency is only restricted to certain cell types including terminally differentiated ones, and the absence of p27 in these cells can interfere with their differentiation.

Effects of oral intake of nitrates on reproductive functions of bulls.

Effects of oral intake of nitrates on selected biochemical and endocrinological indices and its impact on reproductive functions were investigated in five feeder bulls aged 16-18 months. The bulls were tested prior to (30 days), during (30 days) and after (35 days) the period of the nitrate administration. The initial dose of 100 g potassium nitrate per day was increased at weekly intervals by 50 g up to 250 g per day.

[Testosterone production after in vitro stimulation of testicular cells with gonadotropins in bulls].

The response of bulls' testicular cells to the stimulation by serum gonadotropin ad us. vet. (Bioveta, Ivanovice in Haná) was investigated in in vitro tests.