a Social, Genetic, Developmental & Psychiatry Centre, Institute of Psychiatry, King's College London, London SE5 8AF, United Kingdom b School of Education, University of Delaware, Newark, DE 19716 USA c Psychology Department, Logan Hall 160, University of New Mexico, MSC03 2220 Albuquerque, NM 87131 USA d Department of Pathology, School of Medicine, University of New Mexico, MSCO8 4640, Albuque...

Several recent studies have shown that the fecundity of a man decreases progressively with sperm concentrations below 40 million spermatozoa per mL. Therefore, it is unfortunate that the new World Health Organization guidelines for semen analysis recommend lowering the lower cutoff value for normal sperm concentration from 20 to 15 million spermatozoa per mL. As a result large groups of subfert...

Bulls vary greatly in semen quality, both among bulls and among ejaculates within a bull. Therefore, semen is evaluated routinely using those characteristics that are known to affect fertility. These include general appearance of the semen, volume of the ejaculate, concentration of sperm, motility, metabolic activity, percent live/dead and morphological abnormalities. The minimum levels for a s...

background: exposures to lead above the threshold value of 50–60 μg/dl have been linked to diminished semen quality parameters. worldwide, the lead exposure has been diminished during the last years. therefore, it has become of a great concern to examine the effects of lead exposures on semen quality at low levels of exposure. objective: to evaluate the effect of low level (<20 μg/dl) blood lea...

the purpose of this study was to evaluate the probable effects of the vitamin e addition in different levels to the extender of chicken semen on spermatozoa quality during storage of semen at 4°c for 0, 3, 6, 10 and 24 hours. eight young ross broiler breeder strain 308 roosters were used in this experiment. the collected semen from all roosters was mixed together and diluted with modified a rin...

BACKGROUND The population of healthy Polish men has not been frequently and systematically investigated for fertility status. The aim of this study was to assess the quality of semen in a randomly recruited population of young males. The most important task was to find a relationship between semen parameters, sex hormones, and AR gene polymorphism. MATERIAL AND METHODS Semen and blood samples...

Multiple studies from around the world have suggested that semen quality is declining globally. However, all studies suffer from variable semen sampling criteria, selection bias with respect to the types of men volunteering to participate, and a bias with respect to a tendency to examine only samples from high-income countries. This heterogeneity in approaches, especially given the undersamplin...

BACKGROUND Oligoasthenoteratozoospermia (OAT) syndrome is the most frequently seen phenotype in male infertility. Spermatogenesis relies closely on hormone regulation. The aim of this study was to assess the correlation between hormone profile and semen parameters in infertile men with idiopathic or varicocele-related OAT syndrome. We tried to illustrate the correlative factors for better semen...