精子形态与精子运动参数关系研究

目的:探讨精子形态与精子运动参数关系。方法:783例不育患者,采用精子自动分析系统分析精子运动参数,采用精子形态检测系统下人工修正方法进行精子形态分析。精子形态正常组241例,异常组542例。结果:精子形态异常组精子曲线速度(VCL)、摆动性(WOB)、平均路径速度(VAP)均显著高于精子形态正常组(P<0.05,P<0.001),而精子形态异常组精子平均移动角度(MAD)、直线性(LIN)、前向性(STR)均显著低于精子形态正常组(P<0.05,P<0.001);形态正常精子百分率与MAD、LIN、WOB、STR有显著正相关性,而与侧摆幅度(ALH)有显著负相关。结论:精子形态异常和运动能力弱相伴产生,形态异常对精子运动的影响可能只是这一现象产生的次要原因,而一些共同作用于精子形态和运动能力的因素也许是导致这一现象产生的主要原因。     

精子形态与精子功能关系研究进展

回顾近年来精子形态方面的相关文献,阐明精子形态分析在男性生育力评价中的重要价值。分析了精子形态分析技术的现状,阐述了各种精子功能试验与精子形态的关系。尽管精子形态分析技术尚待完善,但基于精子功能与精子形态间的密切关系,以及精子形态分析在辅助生殖领域中体现出的巨大预测价值,显示出精子形态分析的重要地位。     

精索静脉曲张对精子染色质结构及运动能力的影响

目的:探讨精索静脉曲张对精子染色质结构及运动能力的影响。方法:对精索静脉曲张组(无慢性疾病及生殖系统病史者,n=74)和对照组(n=89)进行精子染色质结构分析(SCSA)和精液常规分析(精液量、粘稠度、pH值、精子顶体完整率、精子存活率、畸形率、精子密度、活动率及各运动参数)。结果:精索静脉曲张组精子密度、a+b级精子百分率和精子存活率[分别为(41.4±38.7)×106/ml,(31.7±16.9)%,(62.8±22.2)%]显著低于对照组[分别为(80.9±63.1)×106/ml,(46.8±20.5)%,(77.2±17.5)%],P均<0.05;精子运动参数VCL、VSL、VAP精索静脉曲张组分别为(37.4±12.5)、(23.4±7.8)、(26.5±8.2)μm/s,对照组分别为(42.4±10.7)、(27.3±7.3)、(30.7±7.8)μm/s,精索静脉曲张组与对照组相比显著降低(P均<0.05),而MAD显著增加(P<0.01),SCSACOMPαt值精索静脉曲张组(为23.2±16.2)明显高于对照组(为14.1±11.8)(P<0.05)。结论:精索静脉曲张引起精子DNA损伤和精子运动能力的改变,可能是导致男性不育的主要原因之一。     

CatSper与精子超活化

精子超活化是受精前精子运动方式发生改变的过程,Ca2+参与这一过程,诱导精子鞭毛发生不对称运动。CatSper是近来发现的一类仅存于精子鞭毛上的阳离子通道,作为Ca2+内流的通道参与精子超活化过程。现就目前CatSper在小鼠上的研究现状,对其蛋白结构、分布、在精子超活化过程中调节Ca2+的作用以及尚待解决的问题作一综述。     

Sperm chromatin

Available data on dry and hydrated nuclear volume of mammalian spermatozoa indicate that available volume is clearly insufficient to contain sperm chromatin packed in nucleosome-like structures. Therefore, sperm DNA-protein complexes must be packed differently than somatic DNA-protein complexes. Packing of DNA in fixed, dehydrated mammalian sperm approaches the physical limits of molecular compaction, making mammalian sperm chromatin the most condensed eukaryotic DNA known. The fundamental packaging unit of sperm chromatin is a toroid approximately 900-A outer diameter. 200-A thickness, and 150-A diameter hole. Each toroid contains 60 kilobases of DNA and is linked to other toroids by uncoiled DNA stretches. The factors that contribute to mammalian chromatin structuration are still under study. The role of protamines in sperm chromatin condensation and nuclear shaping has been overstressed to the exclusion of other possible factors. Chromatin organization in sperm nuclei is maintained during sperm condensation by tight interactions with the nuclear matrix at fixed sites, inducing the formation of individual toroid-shaped DNA loop stuctures. Observations that abnormal manchettes affect sperm head shape and chromatin organization inducing sterility speak about manchette importance during chromatin organization. The presence in sperm chromatin of regions packaged in specific ways with several types of protamines or even with histones, indicates that nuclear shaping and chromatin organization must be under DNA control. The structural properties that distinguish sperm DNA from somatic DNA may play the most important role in chromatin organization.     

精子质量与胚胎质量

衡量男性的生殖能力一般采用WHO的精液分析标准,包括精子的活力、密度、畸形率等,然后结合女方的一些相关检查,为夫妇选择适应的妊娠方式.对于婚后1年规律性生活仍未怀孕者,则认为是不孕,应选择合适的助孕治疗.随着卵胞浆内单精子注射(ICSI)的发展,男性不育得到了有效的治疗,但ICSI却使精子的自然选择作用消失,操作过程中有可能选择了质量差的精子进行受精,其胚胎的发育和质量、妊娠率及妊娠结局不能达到期望的水平.     

Evaluation of Sperm Counts and Total Sperm Counts in 2543 Men Requesting Vasectomy

Bei 2.543 Männern, die bei der "Geplante Elternschaft" in Houston urn eine Vasektomie gebeten hatten, wurden Spermaanalysen durchgeführt; die Ergebnisse wurden mit denen früherer Mitteilungen über fertile Männer verglichen. Die Vergleiche ergeben, daß die Mittelwerte der Spermatozoenzahl und der Totalspermatozoenzahl signifikant niedriger liegen als sie 1951 publiziert wurden. Darüber hinaus wurde ein Wechsel in der Häufigkeitsverteilung der Spermatozoendichte und der Gesamtspermatozoenzahl pro Ejakulat festgestellt.
In dem jetzigen Bericht und in anderen neueren Mitteilungen wurden höhere Prozentsätze von Männern mit einer Spermatozoendichte unter 20 Mill./ml und einer Gesamtspermatozoendichte unter 100 Mill./ml gefunden als 1951 publiziert. Diese Befunde weisen daher darauf hin, daß die Standards, wie sie 1951 für die Infertilität des Mannes vorgeschlagen wurden, nicht mehr länger annehmbar sind.     

人类精子的趋化性:接触前的精-卵通讯

已经通过各种实验证实了人类和鼠类精子在卵泡液中具有趋化性。业己发现在给定的精子群中只有一小部分 (平均 10 %左右 )具有趋化性应答 ,这一小部分精子构成了获能精子。精子的趋化性应答和获能状态都是短暂的 (寿命在 5 0min到 4h) ,它们在精子的一生中只出现一次。已有人提出 ,精子趋化性在哺乳动物 (至少在人类 )所起的作用是获能精子为使卵子受精的选择性募集现象。趋化性或获能精子的不断置换可延长其在女性生殖道内有效的时间。精子化学引诱剂至今尚未被鉴定出来 ,但它们可能是一些对热稳定的肽。尚不清楚精子趋化性在体内的定位 ,但许多可能的位置将在本文中讨论     

重组人睾丸精子结合蛋白对人精子运动参数的影响

目的:探讨重组人睾丸精子结合蛋白(TSBP)对体外培养人精子运动参数的影响。方法:将22例生育男性的精液经Percoll密度梯度离心后,分别与0.01mg/ml及0.1mg/ml的重组His6-TSBP在体外共同孵育1h或3h,同时设立对照组,Western印迹检测重组His6-TSBP与精子膜的结合情况,计算机辅助精液分析(CASA)系统测定重组His6-TSBP对精子运动参数的影响。将12例弱精子症患者的精液按同样方法处理,检测重组His6-TSBP对弱精子症患者精子运动参数的影响。结果:0.1mg/ml重组His6-TSBP与生育男性精子作用1h可以提高体外培养精子的前向运动百分率(a+b级精子百分率),培养3h后前向运动百分率和活率均有所提高,差异具有显著性(P<0.05);0.01mg/ml重组His6-TSBP对检测各指标均无显著性影响。0.1mg/ml重组His6-TSBP与弱精子症患者精子作用3h可以提高精子前向运动百分率(P<0.05),但对活率无显著影响。结论:0.1mg/ml的重组His6-TSBP在体外可以提高生育男性精子的前向运动百分率和活率及弱精子症患者精子的前向运动百分率。     

Changes in Porcine Sperm Lactate Dehydrogenase Isoenzymes During Sperm Maturation

The changes in sperm lactate dehydrogenase (LDH-lactate: NAD oxidoreductase, EC 1.1.1.27) activity and the relative occurrence of LDH isoenzymes during sperm maturation were studied using pubertal German improved Landrace boars. The LDH of spermatozoa liberated from the testis, caput epididymis, proximal and distal corpus epididymidis and cauda epididymidis was spectrophotometrically quantified while the LDH isoenzymes were separated on fine cellulose acetate membrane strips with the Sartorius Sartophor system. The LDH content of sperm dropped drastically as they moved from the testis to the caput epididymidis. Thereafter, only little and insignificant changes were observed. Testicular sperm was composed more of the fastest anodically-migrating isoenzyme (LDH1) while with sperm maturation, the least or slowest migrating isoenzymes (LDH4 and 5) became progressively more dominant. This loss in LDH content in sperm and the shifts in the LDH isoenzyme patterns indicate that the development of sperm during maturation is dependent on a delicate balance between lactate and pyruvate, such that the cathodic isoenzymes involved in the anaerobic energy-supplying metabolic processes are sufficiently available for sperm activity and survival.     

Postmortem Sperm Procurement

Purpose

We determined the prevalence of requests for postmortem sperm procurement and the degree to which procurement is performed by those working in the field of infertility.

Materials and Methods

Structured telephone interviews were conducted with personnel at 273 assisted reproductive facilities in the United States and Canada. The number of facilities reporting requests and the number of facilities reporting that they performed the procedure were determined.

Results

The prevalence of requests for postmortem sperm procurement was much greater than initially anticipated. A total of 82 requests was reported at 40 facilities in 22 different states between 1980 and 1995. More than half of the reported requests (43) were made between 1994 and 1995. Of the 82 requests 25 were honored at 14 facilities in 11 different states. No requests or procedures were reported from Canada.

Conclusions

Medical advances in postmortem sperm procurement, cryopreservation and in vitro fertilization permit retrieval of sperm after death for various purposes, including posthumous fatherhood. There are no explicit ethical guidelines, legislation or relevant case law, and fertility specialists must confront these issues before proceeding in a field fraught with moral and policy uncertainties.     

Sperm DNA fragmentation

Several techniques have been developed to measure the amount of sperm DNA damage in an effort to identify more objective parameters for evaluation of infertile men. The integrity of sperm DNA influences a couple's fertility and helps predict the chances of pregnancy and its successful outcome. The available tests of sperm DNA damage require additional large-scale clinical trails before their integration into routine clinical practice. The physiological/molecular integrity of sperm DNA is a novel parameter of semen quality and a potential fertility predictor. Although DNA integrity assessment appears to be a logical biomarker of sperm quality, it is not being assessed as a routine part of semen analysis by clinical andrologists. Extensive investigation has been conducted for the comparative evolution of these techniques. However, some of these techniques require expensive instrumentation for optimal and unbiased analysis, are labor intensive, or require the use of enzymes whose activity and accessibility to DNA breaks may be irregular. Thus, these techniques are recommended for basic research rather than for routine andrology laboratories. Sperm chromatin structure evaluation is applied to detect male factors that may affect the chance of success with IVF as well as natural fertility. Further research is needed to define the optimal test of sperm chromatin structure. The clinical application of this test will evolve as well.     

Sperm protein carbonylation

The cryopreservation of sperm is a well established technique that plays an essential role in dissemination of elite germplasm of livestock. Despite having numerous advantages, the cryopreservation induces certain stresses on sperm including structural and functional damages leading to impaired sperm quality and fertility, which might be associated with production of reactive oxygen species (ROS). In addition, the ROS upon reacting with sperm lipids, DNA and proteins may lead to a cascade of sperm damages. The sperm membrane contains a rich amount of polyunsaturated fatty acids, which increases their susceptibility to oxidative stress induced damages, leading to formation of secondary products. These secondary products result in oxidation of sperm proteins via carbonylation. The carbonylation could lead to disturbances in specific proteins that are involved in capacitation. The present review deals with sperm protein carbonylation.