Nonobstructive azoospermia (NOA) is characterized by the complete absence of sperm in the ejaculate due to testicular failure. The evaluation and management of patients with NOA offer a challenge to the reproductive urologist. In the era of in vitro fertilization with intracytoplasmic sperm injection, surgical sperm extraction techniques can afford men with NOA biologic paternity. To provide a ...

Although sperm are typically thought to be small, tadpole-like cells produced in vast quantities, sperm size, form and number all vary tremendously across species. Sperm form ranges from amoeboid or discoid to multiflagellate elongated structures [1]. Even within the more familiar uniflagellate spermatozoa, length varies by several orders of magnitude, from the tiny 28μm long porcupine sperm to...

introduction: pyrethroids are important insecticides because of their high activity and low mammalian toxicity. some studies have demonstrated that these insecticides, especially compounds with an -cyano group, produce toxic effects on various biological systems. deltamethrin (dtm) is a type ii synthetic pyrethroid insecticide containing -cyano group and is used worldwide in agriculture, home...

background: to determine any correlation between infertility and semen quality with concentrations of l-carnitine in human seminal plasma. methods: this case-control study performed in fatemieh hospital in hamadan, iran. seminal plasma of 72 infertile men and 80 men with proved fertility as a control group was investigated and l-carnitine level was determined using uv enzymatic test at 340 nm. ...

background: recurrent spontaneous abortion impacts almost 1% of couples. the sera from women with unexplained recurrent spontaneous abortion (ursa) have toxic effects on embryos that grow in the uterus. therefore, the abnormal condition of the uterus may also affect sperm qualities. objective: the objectives of this study were to search if these sera could induce dna denaturation in sperm nucle...

background: sperm preparation is a fundamental step in art and attempt for developing new methods to be continued. objective: to evaluate the efficacy of upstream method for separation of human spermatozoa and its effects on sperm parameters including: motility morphology and concentration. materials and methods: semen samples from 17 men who referred to infertility clinic for evaluating their ...

the purpose of this study was to evaluate the efficiency of intracytoplasmic sperm injection (icsi) and piezo-assisted sperm injection after pretreatment with calcium ionophore (cai) on the mouse embryo development. methods: in this study, the conventional icsi and piezo-icsi procedures were used. the efficacy of the methods was examined after mouse matured oocytes were fertilized with or witho...

Sperm conjugation occurs when two or more sperm physically unite for motility or transport through the female reproductive tract. In many muroid rodent species, sperm conjugates have been shown to form by a single, conspicuous apical hook located on the sperm head. These sperm "trains" have been reported to be highly variable in size and, despite all the heads pointing in roughly the same direc...

BACKGROUND Cystatin C (CST3), a cysteine protease inhibitor in seminal plasma, is expressed in animal uteri. However, its expression in the human female reproductive tract and its effect on human sperm capacitation are unclear. METHODS The cellular localization of CST3 was observed using immunohistochemistry. The binding of CST3 to sperm was examined using immunocytochemistry. Sperm motility ...

Sperm competition theory predicts that when males are certain of sperm competition, they should decrease sperm investment in matings with an increasing number of competing ejaculates. How males should allocate sperm when competing with differently sized ejaculates, however, has not yet been examined. Here, we report the outcomes of two models assuming variation in males' sperm reserves and male...