Natural killer cells and reproductive failure--theory, practice and prejudice

The relationship between peripheral blood natural killer (NK) cells and reproductive failure is one of the most controversial areas in reproductive medicine. Amidst much publicity, peripheral blood NK cell testing is being promoted as a useful diagnostic test to guide the initiation of a variety of immunosuppressive therapies amongst patients with either recurrent miscarriage or infertility. We contend (i) that at present there is no scientific basis for the introduction of NK cell testing into routine clinical practice, and (ii) that the use of immunosuppressant agents based on the results of such testing may potentially be harmful.     

Feeding and locomotion responses to centrally injected nociceptin/orphanin FQ in chicks

Nociceptin/orphanin FQ (N/OFQ), the endogenous ligand of the opioid receptor-like receptor or nociceptin receptor (NOP), has been shown to induce feeding, locomotion, anti-stress and anxiolytic effects in rodents after central nervous system injection. In this study, the effect of intracerebroventricular (icv) injection of N/OFQ on feeding and locomotion behavior was evaluated in male broiler-type chickens. The icv injection of N/OFQ caused a moderate but significant increase in feed intake similar to the classical opioid peptides in rats. It also increased feed pecking frequency and feeding time 1 h after injection. Stepping, wing flapping and preening were not affected by N/OFQ. These results suggest that N/OFQ can act within the central nervous system of chickens to increase feed intake.     

Capacitation-dependent concentration of lipid rafts in the apical ridge head area of porcine sperm cells

Lipid architecture of the plasma membrane plays an important role in the capacitation process of the sperm cell. During this process, an increase in membrane fluidity takes place, which coincides with a redistribution of cholesterol to the apical region of the head plasma membrane and subsequently an efflux of cholesterol. Cholesterol is also a major player in the formation of lipid rafts or microdomains in the membrane. Lipid rafts favour specific protein-protein interactions by concentrating certain proteins in these microdomains while excluding others. In this study, we investigated the organization of lipid rafts during in vitro capacitation of boar sperm cells. We report on the presence of the lipid raft-specific proteins caveolin-1 and flotillin-1 in sperm cells. Capacitation induced a change in membrane distribution of these proteins. Lipid analysis on detergent-resistant membranes (DRMs) of sperm cells indicated that capacitation induces a lipid raft concentration rather than a disintegration of lipid rafts, because the total amount of lipid in the DRM fraction remained unaltered. Using a proteomic approach, we identified several major DRM proteins, including proteins involved in capacitation-dependent processes and zona pellucida binding. Our data indicate that sperm raft reorganization may facilitate capacitation-specific signalling events and binding to the zona pellucida.     

Experimental vitrification of human compacted morulae and early blastocysts using fine diameter plastic micropipettes

BACKGROUND: Vitrification of human blastocysts has been successfully applied using grids, straws and cryoloops. We assessed the survival rate of human compacted morulae and early blastocysts vitrified in pipette tips with a smaller inner diameter and solution volume than the previously described open pulled straw (OPS) method. METHODS: Excess day 5 human embryos (n = 63) were experimentally vitrified in vessels. Embryos were incubated at 37 degrees C with sperm preparation medium (SPM) for 1 min, SPM + 7.5% ethylene glycol (EG)/dimethylsulphoxide (DMSO) for 3 min, and SPM + 16.5% EG + 16.5% DMSO + 0.67 mol/l sucrose for 25 s. They were then aspirated (0.5 microl) into a plastic micropipette tip (0.36 mm inner diameter), exposed to liquid nitrogen (LN(2)) vapour for 2 min before being placed into a pre-cooled cryotube, which was then closed and plunged into LN(2). Embryos were warmed and diluted using 0.33 mol/l and 0.2 mol/l sucrose. RESULTS: The survival rate for compacted morulae was 73% (22/30) and 82% (27/33) for early blastocysts. CONCLUSIONS: The survival rates of human compacted morulae and early blastocysts after vitrification with this simple technique are similar to those reported in the literature achieved by slow cooling and other vitrification protocols.     

Assisted reproduction in male cancer survivors: fertility treatment and outcome in 67 couples

BACKGROUND: Many male cancer survivors experience fertility problems due to antineoplastic treatment. We report the fertility outcome in 67 couples referred to assisted reproduction treatment (ART) because of male factor infertility due to cancer. METHODS: This was a retrospective study assessing the following parameters: diagnosis, cancer treatment, type of fertility treatment and type of sperm used, number of pregnancies and pregnancy outcome. RESULTS: Testicular cancer and lymphomas were the most prevalent diagnoses. Adjuvant treatment with chemo- and/or radiation therapy had been given to 90% of the men. Semen was cryopreserved in 82% of the men prior to treatment. Following antineoplastic treatment, 43% of the men had motile spermatozoa in the ejaculate, but 57% were azoospermic. A total of 151 ART cycles were performed [55 intra-uterine insemination (IUI), 82 ICSI and 14 ICSI-frozen embryo replacement (FER)]. The clinical pregnancy rate per cycle was 14.8% after IUI, 38.6% after ICSI and 25% after ICSI-FER. The corresponding delivery rates were 11.1, 30.5 and 21%. Cryopreserved semen was used in 58% of the pregnancies. The delivery rate per cycle was similar after use of fresh or cryopreserved spermatozoa. CONCLUSIONS: Male cancer survivors have a good chance of fathering a child by using either fresh ejaculated sperm or cryopreserved sperm.     

Caspase-dependent and -independent DNA fragmentation in Sertoli and germ cells from men with primary testicular failure: relationship with histological diagnosis

BACKGROUND: Germ cell elimination and sperm DNA fragmentationin men with primary testiculopathies involve apoptosis-relatedprocesses whose mechanisms are poorly understood. This studyexamines the participation of typical (caspase-dependent) andatypical (caspase-independent) pathways in these processes.METHODS: Caspase activity and DNA fragmentation were evaluatedin Sertoli and germ cells from 63 men with non-obstructive azoospermiaand with different histological diagnoses who were undergoingtesticular biopsy for an assisted reproduction attempt. In eightof these men, phosphatidylserine externalization was also examined.RESULTS: The percentage of Sertoli cells showing caspase activityand DNA fragmentation was low and uniform in all diagnoses.In germ cells that remained tightly associated with Sertolicells despite vigorous mechanical treatment, the incidence ofboth caspase activity and DNA fragmentation was high, particularlyin men with maturation arrest. In Sertoli cell-free germ cells,high incidence of DNA fragmentation contrasted with low incidenceof caspase activity and phosphatidylserine externalization.CONCLUSIONS: In men with primary testicular failure, apoptosisof Sertoli cells is insignificant. Some germ cells undergo caspase-dependentapoptosis, show phosphatidylserine externalization and are tightlyassociated with Sertoli cells. Other germ cells show caspase-independentDNA fragmentation, do not externalize phosphatidylserine andlack a tight association with Sertoli cells.     

高压氧对人重症牙周炎牙龈血流量、血流速度和血浓度作用及机理研究

目的 :探讨高压氧 (HBO)对人重症牙周炎牙龈血流量 (GBF)、血流速度 (BCV)和血浓度 (BC)的作用及HBO治疗牙周炎的机理。方法 :选自口腔中心门诊的 3 0例重症牙周炎患者 ,随机分为二组 ,即治疗组和对照组 ,治疗组用HBO治疗 ,对照组用漱口液漱口。用激光多普勒血流仪测定二组治疗前后的GBF、BCV和BC。结果 :HBO能使牙周炎患者GBF增加 2 .1倍 ,BCV增加 6.7倍 ,BC降低为治疗前的 5 8.2 % ,与对照组比均有非常显著性差异 (P <0 .0 1)。结论 :HBO能使牙周炎患者GBF和BCV增加 ,BC减少 ,能改善牙龈微循环 ,对治疗牙周炎有积极意义     

Osteopontin affects the persistence of beta-glucan-induced hepatic granuloma formation and tissue injury through two distinct mechanisms

Osteopontin (OPN) plays a pivotal role in various immune responses and inflammatory diseases. OPN is expressed in various granulomatous diseases; however, the cellular and molecular role of OPN in these diseases is not well known. We analyzed the role of OPN in a beta-glucan-induced hepatic granuloma model. First, we found that neither OPN deficiency nor overexpression of OPN affected the number and the size of hepatic granulomas at day 7, indicating that OPN is not involved in the formation of hepatic granulomas at the early stages. Importantly, OPN did not influence the liver tissue damage as defined by alanine aminotransferase and aspartate aminotransferase levels at early stages. Second, OPN deficiency resulted in the reduction of IL-12 and IFN-gamma production at early stages. Third, at late stages, OPN deficiency resulted in a decrease in the number and size of hepatic granulomas, and a reduction of liver tissue injury. This was due to the reduction of the cellular recruitment including macrophages, CD4 T cells and dendritic cells into the liver, and the reduction of tumor necrosis factor (TNF)-alpha production in the liver. In contrast, overexpression of OPN resulted in the persistence of granuloma formation. These data suggest that OPN affects the persistence of hepatic granuloma formation. Our results indicate that OPN up-regulates the production of IL-12 and IFN-gamma within the granulomas at early stages, and OPN has an additional role in the regulation of cellular recruitment and TNF-alpha production at late stages that determine the severity of liver tissue injury.     

A combination of interleukin-6 and its soluble receptor impairs sperm motility: implications in infertility associated with endometriosis

BACKGROUND: We previously reported that the level of interleukin (IL)-6 is increased in the peritoneal fluid of women with endometriosis. This study was undertaken to assess the effects of IL-6 and soluble IL-6 receptor (sIL-6R) on in vitro sperm motility. METHODS: Sperm (n = 20) were cultured with IL-6 or sIL-6R, or with a combination of both. After 24 h cultures, sperm motility was evaluated using a computer-assisted semen analysis system. Gene and protein expressions of IL-6, IL-6 receptor (IL-6R), and glycoprotein 130 (gp130) were examined in sperm by RT-PCR analysis and western blot analysis. RESULTS: Addition of IL-6 or sIL-6R individually to the culture media had no affect on sperm motion. However, adding a combination of IL-6 and sIL-6R dose-dependently reduced the percentage of motile and rapidly moving sperm. Adding anti-IL-6R antibody abolished these adverse effects. Sperm expressed the gp130 gene and protein, but not IL-6 or IL-6R. CONCLUSIONS: A combination of IL-6 and sIL-6R may be associated with gp130 expressed in the sperm and reduce sperm motility. IL-6 and sIL-6R may contribute to the pathogenesis of endometriosis-associated infertility.     

Chloride transport in the renal proximal tubule

The renal proximal tubule is responsible for most of the renal sodium, chloride, and bicarbonate reabsorption. Micropuncture studies and electrophysiological techniques have furnished the bulk of our knowledge about the physiology of this tubular segment. As a consequence of the leakiness of this epithelium, paracellular ionic transport--in particular that of Cl(-)--is of considerable importance in this first part of the nephron. It was long accepted that proximal Cl(-) reabsorption proceeds solely paracellularly, but it is now known that transcellular Cl(-) transport also exists. Cl(-) channels and Cl(-)-coupled transporters are involved in transcellular Cl(-) transport. In the apical membrane, Cl(-)/anion (formate, oxalate and bicarbonate) exchangers represent the first step in transcellular Cl(-) reabsorption. A basolateral Cl(-)/HCO(3)(-) exchanger, involved in HCO(3)(-) reclamation, participates in the rise of intracellular Cl(-) activity above its equilibrium value, and thus also contributes to the creation of an outwardly directed electrochemical Cl(-) gradient across the cell membranes. This driving force favours Cl(-) diffusion from the cell to the lumen and to the interstitium. In the basolateral membrane, the main mechanism for transcellular Cl(-) reabsorption is a Cl(-) conductance, but a Na(+)-driven Cl(-)/HCO(3)(-) exchanger may also participate in Cl(-) reabsorption.