Bovine cumulus-oocyte disconnection in vitro

Summary Cumulus-oocyte complexes were obtained from cows by aspiration of small (1–6 mm in diameter) antral follicles after slaughter. Complexes with a compact multilayered cumulus investment were cultured and processed for transmission electron microscopy after different periods of culture including a 0 h control group. In 0 h control oocytes the cumulus cells had numerous projections which penetrated the zona pellucida and established gap junctions with the oolemma. A partial loss of these junctions was noticed as an early event of oocyte maturation occurring within the first 3 h of culture. A low frequency of gap junctions was maintained until 12–18 h of culture where the junctional contact was completely disrupted. This decrease in intercellular communication was parallelled by resumption of oocyte meiosis.     

rhGM—CSF对小鼠口腔粘膜损伤的防治作用

目的：观察rhGM-CSF对TMX致实验性小鼠口腔粘膜损伤的疗效。方法：按随机分组原则将501只昆明种小白鼠分成8组，分别在相应时间给予不同药物（MTX，CF或rhGM-CSF）的处理因素，于第1－10天光镜下观察小鼠口腔粘膜的病理改变和积分情况。结果：IDMTX致口腔粘膜损伤病变率（45％－63％）和积分率（19．4％－56％）较其它组高，且死亡率很低（小于5％）；IDMTX＋GM0（或GM2）组的口腔粘膜损伤病变率（30．53％和30．99％）和积分率（19．47％和17．25％）比IDMTX组（55．56％和36．31％）明显减少，且溃疡严重程度较轻，二者相差显著（P＜0．01）。结论：IDMTX致小鼠口腔粘膜损伤模型可以用于粘膜损伤的研究；rhGM-CSF可以减少MTX致小鼠口腔粘膜损伤，并促进粘膜损伤恢复。     

964天冷冻保存的马来微丝蚴的生物学特性

参照Ham等的二步冷冻法,在含有5％DMSO和20％小牛血清的台氏液中,马来微丝蚴冷冻保存(-196℃)964天,复苏后仍具有活力,其平均存活率达94.2％,平均正常外貌达71.4％,平均活动等级达2.45。对中华按蚊的感染率为18.4％,感染度为2.36条/只。     

深低温冷冻肌腱细胞活性的研究

目的研究深低温冷冻方法对肌腱细胞活性的影响,比较程序性降温和普通深低温冷冻法对腱细胞活性的影响.方法纯种SD大鼠24只（出生21 d）,随机分为3组,取双侧跟腱.新鲜肌腱对照组（A）,常规深低温冷冻组（B）,程序性降温深低温冷冻组（C）.采用相同的方法对3组肌腱细胞进行细胞培养.相差显微镜观察原代和传代后细胞的生长,绘制细胞的生长曲线,考察细胞的活性;对细胞进行成纤维细胞染色、胶原染色和对细胞进行形态观察（扫描电镜）;水解法定量分析细胞培养基中羟脯氨酸浓度的变化,检测细胞合成胶原的能力.结果原代细胞培养时A组细胞的生长速度快于B组和C组（P＜0.01）,C组细胞的生长速度快于B组（P＜0.01）,这种生长速度的差异在细胞传代后消失.细胞的形态学和组织学符合成纤维细胞形态.3组细胞培养基中羟脯氨酸浓度变化的差异无统计意义（P＞0.05）.结论经深低温冷冻处理的肌腱中仍存在具有活性的腱细胞,但数量显著少于新鲜肌腱中活细胞的数量.应用计算机控制程序性慢速降温方法处理的肌腱其活细胞的数量有所提高,但仍低于新鲜肌腱中活细胞的数量.     

Fertility in patients with multiple sclerosis: current knowledge and future perspectives

Abstract The issue of fertility in patients with multiple sclerosis (MS) has not been exhaustively studied. Epidemiological data have suggested that spontaneous fecundity might be reduced; several endocrine and sexual disturbances potentially interfering with reproduction have been evidenced in MS patients of both sexes. Moreover, some medical treatments used in MS (e. g., mitoxantrone, cyclophosphamide) may exert detrimental effects on spermatozoa as well as on oocytes, leading to early impairment of fertility. This review illustrates the factors potentially interfering with fertility in MS and discusses the therapeutic tools that may be used to promote fertility in these patients. The safety of hormonal therapies in MS is also examined. The current applications of assisted reproductive technology (ART) are discussed, including in vitro fertilisation (IVF) techniques. Currently available methods to preserve fertility in patients that undergo cytotoxic treatments by means of sperm/oocyte cryostorage or by ovarian fragment cryopreservation and autografting are considered.     

Outcome of frozen embryo replacement cycles following elective cryopreservation of all embryos in women at risk of developing ovarian hyperstimulation syndrome

Aim: Our aim was to compare the outcome in subsequent frozen embryo replacement cycles in four groups of patients who had elective cryopreservation of all their embryos because they were considered to be at increased risk of developing severe ovarian hyperstimulation syndrome. Design: Sixty-two (91%) of 68 IVF cycles (68 patients) in which elective cryopreservation of all embryos was performed were analyzed. All patients continued on the GnRH agonist, buserelin, after oocyte recovery until the onset of vaginal bleeding. Frozen embryo replacement occurred in a hormone replacement cycle that started either on day 3 of the withdrawal bleed (group I;N=15) or after serum estradiol levels had fallen to <100 pmol/L (group II;N=16). The other patients commenced a frozen embryo replacement cycle several months later in either a hormone replacement (group III;N=15) or a natural (group IV;N=16) cycle. Results: Two patients developed severe ovarian hyperstimulation syndrome. There were no significant differences among the four groups regarding demographic variables, the dose of hMG used, and the clinical outcome. There was a higher but not significantly different clinical pregnancy rate in group I (26.7%), compared to group II (12.5%), group III (13.3%), and group IV (18.8%). Conclusions: Several options exist for the timing and protocol used for frozen embryo replacement in patients who had elective cryopreservation for the prevention of ovarian hyperstimulation syndrome, none of which was found to be clearly superior in this observational report.Presented at the 1994 Annual Conference of the American Fertility Society.     

Improvement in quality of cryopreserved human spermatozoa by swim-up before freezing

Selecting a population of spermatozoa by the swim-up technique yields, after freezing and thawing, a population of cells that contains proportionally more spermatozoa which are morphologically normal, fewer spermatozoa with damaged tail membranes, and a greater percentage of progressively motile spermatozoa with greater velocities and amplitudes of head displacement than those obtained after freezing and thawing the same semen samples in the normal way. This pattern was found for the semen from 10 patients and five volunteers. However, the cells selected by swim-up were as susceptible to the stresses caused by freezing and thawing as unselected spermatozoa in the original semen sample, and the improvement came from the better quality of the initial sample.     

深低温储皮后其抗原性改变的免疫学研究

以人皮和豚鼠皮新鲜及－１９６℃冷冻皮片匀浆做为抗原，研制出兔抗人和豚鼠的新鲜及－１９６℃冷冻皮片匀浆的可溶性蛋白高效价的免疫血清，并通过免疫电泳、火箭免疫电泳、免疫火箭扩散电泳及单相免疫扩散电泳等不同免疫学电泳的检测，分别对新鲜皮片及－１９６℃冷冻皮片抗原性改变的这一现象进行探讨与研究。结果表明：人皮、豚鼠皮其新鲜皮片的抗原成份、抗原决定簇及抗原量均显著高于相应的－１９６℃冷冻组皮片，因而证实了通过深低温冷冻的皮片其抗原性低于新鲜皮片的论断。     

降调节对卵子质量的影响

近10余年来，在体外受精一胚胎移植（IVF-ET）周期中应用促性腺激素释放激素激动剂（GnRH-a）进行控制性卵巢刺激（COS）已成为普遍采用的方法，其主要原因是GnRH-a可以促进卵巢内多个卵泡同步发育和成熟，抑制内源性黄体生成素（LH）峰，阻遏卵泡过早黄素化及卵子早熟。由于GnRH-a在IVF-ET进行降调节COS中的应用不同，可将COS方案分为长方案和短方案。[第一段]     

Mechanism of action of the epileptogenic drug pentylenetetrazol on a cloned neuronal potassium channel

The action of the epileptogenic agent pentylenetetrazol (PTZ) on a cloned potassium channel of the rat brain was studied. The Kv1.1 channel was expressed in oocytes ofXenopus laevis and potassium currents were investigated in outside-out and inside-out membrane patches. The results show that PTZ increased the multi-channel potassium currents at strongly negative potentials and decreased them at potentials positive to −35 mV both in outside-out and inside-out membrane patches. The extent and manner of PTZ action, the concentration dependence as well as the onset and time course of the PTZ effect were the same both in outside-out and inside-out membrane patches. The single-channel potassium currents showed an increase in open probability and frequency of opening and a decrease in close time at −50 mV and vice versa at 0 mV with application of PTZ. The amplitude of single-channel current, the open time and the latency to the first channel opening remained almost unchanged under PTZ. The results indicate that PTZ acts via the cell membrane and influences the membrane-associated part of the potassium channel. Thereby, PTZ accelerates the transition from the inactivated to the open state of the channel at strongly negative potentials and reduces it at slightly negative and positive potentials. This mechanism may be the basis for a gate function which is in favour of the development of epileptic discharges.