Search results for "sperm"
showing 10 items of 658 documents
Data from: Inbreeding reveals mode of past selection on male reproductive characters in Drosophila melanogaster
2013
Directional dominance is a prerequisite of inbreeding depression. Directionality arises when selection drives alleles that increase fitness to fixation and eliminates dominant deleterious alleles, while deleterious recessives are hidden from it and maintained at low frequencies. Traits under directional selection (i.e., fitness traits) are expected to show directional dominance and therefore an increased susceptibility to inbreeding depression. In contrast, traits under stabilizing selection or weakly linked to fitness are predicted to exhibit little-to-no inbreeding depression. Here, we quantify the extent of inbreeding depression in a range of male reproductive characters and then infer t…
Protandric hermaphrodite peculiarities in Amphiprion frenatus Brevoort (Teleostei, Pomacentridae)
1990
Electron microscopy of the male phase of the ovotestis of Amphiprion frenatus, a protandric hermaphrodite, showed no connective tissue between male and female areas and, as the basal lamina was lacking both along the seminiferous tubules and round the previtellogenic oocytes, the male and female germ cells were only separated by their respective surrounding somatic cells (Sertoli and follicle cells). Besides previtellogenic oocytes, oocytes in meiotic prophase and very small (young) previtellogenic oocytes, were detected in the ovarian part, as spermatogenesis proceeded, revealing oogenetic activity. Degeneration of some previtellogenic oocytes and their follicle cells was discernible.
Angiographien im Kleinkindes- und Kindesalter
1993
Between 1973 and 1991 we performed 160 percutaneous angiograms (130 arteriograms, 30 phlebograms) in children and infants; 12 patients were less than one year and 52 less than ten years old. 44 of the examinations were done by a DSA technique. The examinations were carried out under general anaesthesia except in 8 cases. In 50.7% an arteriogram was carried out for the investigation of a suspected or known tumour, in 9.3% an arteriogram was required following trauma. The most common phlebographic examination was for the demonstration of the spermatic vein; in 27 patients this was done for cryptorchidism or a varicocele. The only complication following a diagnostic angiogram was perforation o…
Substance P inactivation by transglutaminase in vitro.
1992
Gamma(glutamyl5)spermine derivative of substance P (Spm-SP) was synthesized in vitro in the presence of purified guinea pig liver transglutaminase and Ca2+. The spermine adduct of the neuropeptide was purified by HPLC on a reversed-phase column and characterized by fast atom bombardment mass spectrometry. The biological activities of Spm-SP were tested by assaying, in comparison with substance P, its ability to induce both the contractions of smooth muscle in vitro and the edema formation in vivo. Spm-SP was shown not to elicit contractile responses in the isolated rat stomach strip and duodenum and not to antagonize the spasmogenic effect evoked by the native neuropeptide. Furthermore, Spm…
Predictors of live birth in women with a history of biochemical pregnancies after assisted reproduction treatment
2020
Abstract Objectives To ascertain whether women with a history of biochemical pregnancies (BPs) in in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment cycles have decreased chances of live birth (LB); and (2) to build a predictive model for LB in this particular population of infertile women. Methods In order to achieve the first objective, data from 1536 women that had a LB using autologous fresh or frozen embryos, or dropped out of further IVF/ICSI treatments after completing one to three unsuccessful treatment cycles were retrospectively analyzed. A subpopulation of 90 women that experienced one or more BPs in our assisted reproduction unit were selected to buil…
Additive effect of factors related to assisted conception on the reduction of maternal serum pregnancy-associated plasma protein A concentrations and…
2013
Objective To analyze whether assisted conceptions need adjustments in first-trimester Down syndrome screening and why modifications in screening markers occur. Design Eleven-year cohort retrospective analysis. Setting Maternal-fetal medicine unit. Patient(s) Two thousand eleven naturally conceived normal singleton pregnancies and 2,042 normal singleton pregnancies achieved with assisted conception: 350 by IUI and 1,692 with IVF (n = 328) or intracytoplasmic sperm injection (ICSI; n=1,364), using nondonor (n = 1,086) or donated ova (n = 606), with fresh (n = 1,432) or frozen (n = 260) embryos. Intervention(s) Comparison of ultrasound and biochemical markers of first-trimester Down syndrome s…
Oxygen consumption is a quality marker for human oocyte competence conditioned by ovarian stimulation regimens.
2011
Objective To evaluate the effect of different ovarian stimulation protocols on oocyte respiration and to investigate the relationship between oocyte oxygen consumption and reproductive outcome. Design Prospective observational cohort study. Setting Infertility clinic in a university hospital. Patient(s) A total of 349 oocytes from 56 IVF treatment cycles in our oocyte donation program. Intervention(s) None. Main Outcome Measure(s) Average oocyte oxygen consumption rate in fmol/s. We correlated oxygen consumption values with ovarian stimulation features, fertilization, embryo quality on days 2 and 3, and implantation. Result(s) Differences in the measured oxygen consumption rates were found …
Processing Sperm Samples in HIV-Positive Patients
2013
Human immunodeficiency virus is an important public health problem; about 40 million people around the world are actually infected with HIV type 1 virus. Furthermore, prolonged survival of patients under highly active antiretroviral therapy has given rise to a new demand from SDC couples who wish to have children. HIV serodiscordant couples with the male infected wish to make use of assisted reproduction techniques in combination with semen washing in order to decrease the risk of transmission to the partner or to the newborn. Thus it is essential to test the effectiveness of techniques aimed at reducing HIV and HCV loads in infected semen using molecular biology tests. Nevertheless, its ef…
66 RELATIONSHIP BETWEEN PLASMA CHLORIDE LEVELS AND FOLLICLE DIAMETER IN CYCLING SPANISH PUREBRED MARES
2014
Several studies in cows have shown that plasma levels of chloride are positively correlated with the diameter of the preovulatory follicle (FD), establishing at the same time a significant positive association between plasma levels and intraoviducal concentration of this electrolyte (Hugentobler et al. 2007). These relationships may reflect the influence of changes in systemic metabolic plasma on follicular fluid, physiological events that might be closely related to the quality of the oocyte and granulosa cells of the preovulatory follicle (LeRoy et al. 2004). However, these mechanisms remain unknown in the mare. The objective of this research was to investigate the relationship between p…
A time to look back: analysis of morphokinetic characteristics of human embryo development.
2013
Objective To describe the times associated with the morphological changes that occur in the embryo during preimplantation development based on the largest sample size described with time lapse. Design Cohort study. Setting University-affiliated private center. Patient(s) A total of 9,530 embryos from 1,806 intracytoplasmic sperm injection (ICSI) cycles. Intervention(s) None. Main Outcome Measure(s) Using a time-lapse system, embryo images were acquired for at least 68 hours, in some cases reaching 120–130 hours. Embryo cleavage time points up to 8-cell-stage (t2–t8) as well as morulae (tM) and blastocyst formation (tB) were registered in hours after ICSI. Additionally, duration of the cell …