Search results for "Sperm"
showing 10 items of 658 documents
Fetuin-B, a liver-derived plasma protein is essential for fertilization.
2013
SummaryThe zona pellucida (ZP) is a glycoprotein matrix surrounding mammalian oocytes. Upon fertilization, ZP hardening prevents sperm from binding to and penetrating the ZP. Here, we report that targeted gene deletion of the liver-derived plasma protein fetuin-B causes premature ZP hardening and, consequently, female infertility. Transplanting fetuin-B-deficient ovaries into wild-type recipients restores fertility, indicating that plasma fetuin-B is necessary and sufficient for fertilization. In vitro fertilization of oocytes from fetuin-B-deficient mice only worked after rendering the ZP penetrable by laser perforation. Mechanistically, fetuin-B sustains fertility by inhibiting ovastacin,…
Polyamines are increased in obese children and are related to markers of oxidative/nitrosative stress and angiogenesis.
2011
Polyamines (putrescine, spermidine, and spermine) are polycationic amines derived from arginine, which is the precursor of nitric oxide (NO). Due to the close relationship between the metabolism of polyamines and NO metabolism, the alteration in polyamine homeostasis can affect the NO bioavailability at the endothelium.The objective of the study was to test the hypothesis that childhood obesity is associated with a significant modification of blood polyamines and to investigate the presence of correlation between these molecules, circulating markers of oxidative and nitrosative stress, and endothelial dysfunction.This was an observational analytical case-control study conducted at one terti…
Assisted reproductive techniques and risk of exstrophy-epispadias complex: a German case-control study.
2012
We assessed the risk of exstrophy-epispadias complex in children conceived by in vitro fertilization or intracytoplasmic sperm injection.Data from the German Network for Congenital Uro-REctal malformations were compared to nationwide data from the German In Vitro Fertilization Register and the German Federal Statistical Office. Odds ratios (95% CI) were determined to quantify associations using logistic regression.A total of 123 patients with exstrophy-epispadias complex born in Germany between 1997 and 2011 were recruited through participating departments of pediatric urology and pediatric surgery throughout the country as well as the German self-help organizations Blasenekstrophie/Epispad…
Seminal plasma-induced suppression of the respiratory burst of polymorphonuclear leukocytes and monocytes.
1984
Summary: Based on recent findings indicating suppression of lymphocytic functions by seminal plasma (SP) we tested the effects of SP from men with normo- and oligozoospermia (n = 7, each) on the generation of luminol-enhanced chemiluminescence (CL) of polymorphonuclear leukocytes (PMN) and monocytes (Mo) stimulated in vitro with zymosan. We found a complete suppression of CL of PMN and Mo by undiluted SP's, 1,000-fold dilutions still induced ≥ 20 percent inhibition. There was no difference between normo- and oligozoospermic men in inhibition of CL both with PMN and Mo. Protein concentrations of SP's were closely the same; all SP were free of the complement components C4 and C3c. After dialy…
A comparison of the effects of bilateral efferent duct ligation and of partial epididymectomy on the testes of rats.
1990
Testis weight as a percentage of body weight did not change following bilateral ligation of the efferent ducts (EDL) close to the epididymis, whereas following removal of part of the epididymis between the site of ligation and a point close to the junction between the caput and corpus (PCE), testis weight first rose linearly until Day 4 and then showed an exponential decrease between Days 4 and 28. After EDL, the perimeter of the seminiferous tubules rose for the first 7 days and then remained elevated, whereas after PCE, there was a linear decrease between Days 4 and 28. Following EDL, the percentage of altered and degenerated tubular cross-sections rose to about 30% and 10%, respectively,…
Spermatocyte chromosome analysis of Helicella virgata (Pulmonata: Helicidae): silver-stained and C-banded chromosomes.
1991
Chromosome numbers of the snail Helicella virgata from the fields of Castellammare del Golfo (Sicily) are n = 26 and 2n = 52. Silver-staining analyses of testicular cells suggest that both mitotic and meiotic chromosomes are involved in nucleolus organization. A within-individual variability in NOR-banding pattern is present in each of the 20 specimens analyzed.
Failures (with some successes) of assisted reproduction and gamete donation programs
2013
Although the possibilities for the treatment of infertility have been improved tremendously, not every couple will be treated successfully.Crude overall pregnancy rates of 50-65% per patient can be achieved nowadays, irrespective of the type of profertility treatment applied first.IVF only accounts for about 20% of the pregnancies achieved. Dropout is an important reason for not reaching the estimated pregnancy rate. Even after failed IVF, spontaneous pregnancies do occur. Sperm and oocyte donation (OD) offer additional chances to subfertile couples. Severity of the male factor (in sperm donation) and young donor age (in OD) are important determinants of success.Analysis of assisted reprodu…
Effect of inhibiting carnitine biosynthesis on male rat sexual performance.
2008
l-carnitine has a documented role as a cofactor in cellular energy metabolism and fatty acid beta-oxidation pathways and it has also been considered to function in reproductive biology. We investigated whether decreasing concentrations of L-carnitine using an inhibitor of its biosynthesis, mildronate (3-(2,2,2-trimethylhydrazinium)-propionate), would influence the sexual behavior or sperm quality in male rats. Mildronate treatment induced a significant decrease in carnitine concentration and an increase in gamma-butyrobetaine (GBB) concentration in both plasma and testes extracts. However, the expression of carnitine palmitoyltransferase I in testes and testosterone concentration in plasma …
In vivo studies on the antiandrogenic effects of cimetidine versus cyproterone acetate in rats
1981
To investigate the antiandrogenic action of cimetidine in vivo, prostatic androgen uptake and metabolism, spermatogenesis, morphology of the prostate and testes, and plasma hormone levels were studied using Sprague-Dawley rats, and the results were compared with the effects of cyproterone acetate or castration. Cimetidine and cyproterone acetate caused significant reduction in the weights of the ventral prostate and testes. The changes of ventral prostate were accompanied by a dose-related epithelial atrophy. No adverse effect on spermatogenesis was observed after treatment with cimetidine at daily doses of 50 mg/kg or cyproterone acetate of 10 mg/kg. Although cimetidine treatment induced a…
Full in vitro fertilization laboratory mechanization: toward robotic assisted reproduction?
2011
Objective To describe the current efforts made to standardize different steps of assisted reproductive technology processes by the introduction of new technologies for the nonsubjective sperm selection process, oocyte denudation by mechanical removal of cumulus cells, oocyte positioning, sperm motility screening, fertilization, embryo culture, media replacement by microfluidics, and monitoring of embryo development by time-lapse photography, embryo secretions, and/or O 2 consumption. These technologies could be integrated in a unique and fully automated device. Design Pubmed database and research and development data from authors. Setting University-affiliated private center. Patient(s) Non…