Search results for "Sperm"
showing 10 items of 658 documents
Structural characterization and primary in vitro cell culture of locust male germline stem cells and their niche
2011
AbstractThe establishment of in vitro culture systems to expand stem cells and to elucidate the niche/stem cell interaction is among the most sought-after culture systems of our time. To further investigate niche/stem cell interactions, we evaluated in vitro cultures of isolated intact male germline–niche complexes (i.e., apical complexes), complexes with empty niche spaces, and completely empty niches (i.e., isolated apical cells) from the testes of Locusta migratoria and the interaction of these complexes with isolated germline stem cells, spermatogonia (of transit-amplifying stages), cyst progenitor cells, cyst progenitor cell-like cells, cyst cells, and follicle envelope cells. The stru…
PSCDGs of mouse multipotent adult germline stem cells can enter and progress through meiosis to form haploid male germ cells in vitro
2010
Spermatogonial stem cells (SSCs) provide the basis for spermatogenesis throughout adult life by undergoing self-renewal and differentiation into sperm. SSC-derived cell lines called multipotent adult germline stem cells (maGSCs) were recently shown to be pluripotent and to have the same potential as embryonic stem cells (ESCs). In a differentiation protocol using retinoic acid (RA) and based on a double selection strategy, we have shown that ESCs are able to undergo meiosis and produce haploid male germ cells in vitro. Using this differentiation protocol we have now succeeded to generate haploid male germ cells from maGSCs in vitro. maGSCs derived from a Stra8-EGFP transgenic mouse line wer…
Sexual size dimorphism predicts rates of sequence evolution of SPerm Adhesion Molecule 1 (SPAM1, also PH-20) in monkeys, but not in hominoids (apes i…
2010
Based on a dataset comprising coding DNA sequences of 23 anthropoid primates, we herein investigate if rates of sequence evolution of SPerm Adhesion Molecule 1 (SPAM1, also PH-20), which participates in sperm–egg interaction, is lower in more sexually dimorphic species. For comparison, we analyze sequence evolution of apolipoprotein A-IV (APOA4) and apolipoprotein A-V (APOA5), which should evolve under less or even no sexual selection given their expression in blood, digestive tract, liver, and lungs. Regression analyses provides significant support for a negative dependence of SPAM1 derived branch-specific ratios of non-synonymous to synonymous substitution rates (dN/dS) on sexual size dim…
CEP63 deficiency promotes p53-dependent microcephaly and reveals a role for the centrosome in meiotic recombination
2015
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM
Acrosin, the peculiar sperm-specific serine protease.
1991
The sperm enzyme acrosin has long been known as one of the key enzymes in the mammalian fertilization process. Elucidation of primary structures of preproacrosin from various species have allowed a deeper insight into the structural organization and the complex evolution of the sperm proteinase acrosin. In addition to the typical elements of serine proteases, the acrosin molecule possesses one novel domain that might convey DNA-binding properties.
Inhibition of Trypanosoma cruzi by plant extracts used in Chinese medicine.
2004
In this work, we assessed the effect of extracts obtained from 17 plants used in traditional Chinese medicine. These extracts were tested in vitro with the epimastigote form of Trypanosoma cruzi, clone Bra C(15) C(2), at 27 degrees C in F-29 medium at a concentration of 100 microg/ml in axenic cultures. Allopurinol was used as reference drug. Seven plant extracts showed inhibitory activities lower than 25%. Pueraria lobata, Mahonia beaei, Dictamus dasycarpus, Kochia scoparia, Sophora flavescens and Ligustrum lucidum showed effects with inhibition values between 25% and 60%, whereas Lithospermum erythrorhizon, Saussurea lappa, Melia toosendan and Cinnamomum cassia showed the greatest inhibit…
Ethnobotanical survey and cytotoxicity testing of plants of South-western Nigeria used to treat cancer, with isolation of cytotoxic constituents from…
2010
Abstract Ethnopharmacological relevance There is only scant literature on the anticancer components of medicinal plants from Nigeria, yet traditional healers in the area under study claim to have been managing the disease in their patients with some success using the species studied. Aim of study To document plants commonly used to treat cancer in South-western Nigeria and to test the scientific basis of the claims using in vitro cytotoxicity tests. Methods Structured questionnaires were used to explore the ethnobotanical practices amongst the traditional healers. Methanol extracts of the most common species cited were screened for cytotoxicity using the sulforhodamine B (SRB) assay in both…
Ten years' experience with an external quality control program for semen analysis
2012
To gauge the performance of laboratories and impact of the German semen analysis external quality control program (QuaDeGA) over its first 10 years.Retrospective analysis of QuaDeGA's twice yearly distribution of fixed semen samples and electronic material documenting sperm motility. Ranking of each participant's responses was determined according to their relation to a "target window."Multicenter. PAITENT(S): Healthy donors.None.Laboratory performance, World Health Organization (WHO) adherence.Over 19 runs, there was a steady increase of participants (280 laboratories), the largest group being private urologic practices. Although use of WHO-recommended Neubauer chamber (from 33% to 55%) an…
Can We Clinically Distinguish Anejaculation From Retrograde Ejaculation in Patients on α1A-Blockers Therapy for Lower Urinary Tract Symptoms?
2019
To investigate the physiopathology of ejaculatory disorders (EjD) and discriminate between retrograde ejaculation (REj) and anejaculation (AEj) induced by α1A-blockers, through the association between the mean postorgasm seminal vesicle volume and the presence of sperm in midstream urine, in patients with moderate-to-severe lower urinary tract symptoms (LUTS) secondary to benign prostatic enlargement.Therapy-naïve male patients with LUTS and without previous EjD were treated with α1A-blockers. Pre- and post-treatment EjD were investigated through question 4 of the 4-item Male Sexual Function questionnaire and the Male Sexual Health Questionnaire for Ejaculatory Dysfunction Short Form (MSHQ-…