Effect of low-density lipoproteins, spermatozoa concentration and glycerol on functional and motility parameters of bull spermatozoa during storage at 4 °C

An extender has been developed with low-density lipoproteins (LDLs) that eliminates the microbial risks associated with the use of whole egg yolk. The objective of this study was to assess the effects of substituting egg yolk with LDLs for use as an extender in sperm preservation at 4 °C, as well as on spermatozoa motility, plasma membrane and acrosome integrity, at two different concentrations (80×10(6) and 240×10(6) sperm per ml) for 8 days and to evaluate glycerol toxicity in both extenders. A total of 12 ejaculates were collected from three bulls. Spermatozoa motility was examined using computer-assisted semen analysis. Plasma membrane integrity was determined using the hypo-osmotic swelling test and acrosome integrity with the fluorescein isothiocyanate-Pisum sativum agglutinin test. The semen was subsequently divided into four aliquots and diluted with Tris-egg yolk-glycerol (TEG), Tris-egg yolk without glycerol (TE), LDL with glycerol (LDL(+)) and LDL without glycerol (LDL(-)), at 80×10(6) and 240×10(6) sperm per ml. This study showed that the LDL(+) and LDL(-) extenders were more effective at preserving spermatozoa motility, plasma membrane integrity and acrosome integrity than TEG and TE (P<0.05) during 8 days of incubation. After 3 days of incubation, a toxicity of glycerol was observed in TEG, whereas no significant difference was observed between LDL(+) and LDL(-). We can therefore conclude that the LDL extender can be used to refrigerate semen at 4 °C instead of TEG and TE at 80×10(6) and 240×10(6) sperm per ml for elite bulls. This finding can be used to define a policy for the storage of high-quality bull semen.     

Fertilization of in vitro matured human oocytes by intracytoplasmic sperm injection （ICSI） using ejaculated and testicular spermatozoa

AIM: To evaluate the fertilization competence of spermatozoa from ejaculates and testicle when the oocytes were matured in vitro following intracytoplasmic sperm injection (ICSI). METHODS: Fifty-six completed cycles in 46 women with polycystic ovarian syndrome were grouped according to the semen parameters of their male partners. Group 1 was 47 cycles that presented motile and normal morphology spermatozoa in ejaculates and Group 2 was the other nine cycles where male partners were diagnosed as obstructive azoospermia and spermatozoa could only be found in testicular tissue fragment. All female patients received minimal stimulation with gonadotropin. Immature oocytes were matured in vitro and inseminated by ICSI. The spermatozoa from testes were retrieved by testicular fine needle aspiration. RESULTS: A total of 449 and 78 immature oocytes were collected and cultured for 48 hours, 75.5 % (339/449) and 84.6 % (66/78) oocytes were matured in Groups 1 and 2, respectively. The percentage of oocytes achieving normal fertilization was significantly higher in Group 1 than that in Group 2 (72.9 % vs. 54.5 %, P 0.05). There were no significant differences in the rates of oocytes cleavage and clinical pregnancies in these two groups [87.4 % (216/247) vs. 88.9 % (32/36); 21.3 % (10/47) vs. 44.4 % (4/9)]. A total of 15 babies in the two groups were healthy delivered at term. CONCLUSION: It appears that IVM combined with ICSI using testicular spermatozoa can produce healthy infants, while the normal fertilization rate of in vitro matured oocytes after ICSI using testicular spermatozoa was significantly lower than using the ejaculated spermatozoa.     

Cryopreservation of cynomolgus monkey （Macacafascicularis） spermatozoa in a chemically defined extender

AIM: To establish a method for cynomolgus monkey sperm cryopreservation in a chemically defined extender. METHODS: Semen samples were collected by electro-ejaculation from four sexually mature male cynomolgus monkeys. The spermatozoa were frozen in straws by liquid nitrogen vapor using egg-yolk-free Tes-Tris mTTE synthetic extender and glycerol as cryoprotectant. The effects of glycerol concentration (1 %, 3 %, 5 %, 10 % and 15 % [v/v]) and its equilibration time (10 min, 30 min, 60 min and 90 min) on post-thaw spermatozoa were examined by sperm motility and sperm head membrane integrity. RESULTS: The post-thaw motility and head membrane integrity of spermatozoa were significantly higher (P0.05) for 5 % glycerol (42.95 +/- 2.55 and 50.39+/- 2.42, respectively) than those of the other groups (1%: 19.19 +/- 3.22 and 24.84 +/- 3.64; 3%: 34.23 +/- 3.43 and 41.37 +/- 3.42; 10%:15.68 +/- 2.36 and 21.39 +/- 3.14; 15%: 7.47 +/- 1.44 and 12.90 +/- 2.18). The parameters for 30 min equilibration(42.95 +/- 2.55 and 50.39 +/- 2.42) were better (P0.05) than those of the other groups (10 min: 31.33 +/- 3.06 and 38.98 +/- 3.31; 60 min: 32.49 +/- 3.86 and 40.01 +/- 4.18; 90 min: 31.16 +/- 3.66 and 38.30 +/- 3.78). Five percent glycerol and 30 min equilibration yielded the highest post-thaw sperm motility and head membrane integrity. CONCLUSION: Cynomolgus monkey spermatozoa can be successfully cryopreserved in a chemically defined extender, which is related to the concentration and the equilibration time of glycerol.     

The protective effects of α-ketoacids against oxidative stress on rat spermatozoa in vitro

The aim of this study was to determine the effects of antioxidants,including α-ketoacids （α-ketoglutarate and pyruvate）,lactate and glutamate/malate combination,against oxidative stress on rat spermatozoa. Our results showed that H2O2 （250 μmol L^-1）-induced damages,such as impaired motility,adenosine triphosphate （ATP） depletion,inhibition of sperm protein phosphorylation,reduced acrosome reaction and decreased viability,could be significantly prevented by incubation of the spermatozoa with α-ketoglutarate （4 mmol L^-1） or pyruvate （4 mmol L^-1）. Without exogenous H2O2 in the medium,the addition of pyruvate （4 mmol L^-1） significantly increased the superoxide anion （O2^-·） level in sperm suspension （P≤0.01）,whereas the addition of α-ketoglutarate （4 mmol L^-1） and lactate （4 mmol L^-1） significantly enhanced tyrosine-phosphorylated proteins with the size of 95 kDa （P≤0.04）. At the same time,α-ketoglutarate,pyruvate,lactate,glutamate and malate supplemented in media can be used as important energy sources and supply ATP for sperm motility. In conclusion,the present results show that α-ketoacids could be effective antioxidants for protecting rat spermatozoa from H2O2 attack and could be effective components to improve the antioxidant capacity ofBiggers,Whitten and Whittingham media.     

Dimensions of human ejaculated spermatozoa in Papanicolaou- stained seminal and swim-up smears obtained from the Integrated Semen Analysis System （ISAS）

Objective measurements are required for computer-aided sperm morphometric analysis （CASMA） machines to distinguish normal from abnormal sperm heads. The morphometric characteristics of spermatozoa in 72 samples of semen and of spermatozoa from 72 other semen samples after swim-up were quantified by the semi-automated Integrated Sperm Analysis System （ISAS） computer-aided system, which measured the sperm head parameters length （L）, width （W）, area （A）, perimeter （P）, acrosomal area （Ac）, and the derived values L/W and P/A. For each man a homogeneous population of distributions characterized seminal spermatozoa （7 942 cells： median values L 4.4 μm, W 2.8μm A 9.8 μm^2, P 12.5 μm, Ac 47.5%, L/W 1.57, P/A 1.27）, and there was no significant difference in within- and among-individual variation. Different men could have spermatozoa of significantly different dimensions. Head dimensions for swim-up spermatozoa from different men （4 812 cells） were similar to those in semen, differing only by 2%-5%. The values of L, Wand L/W fell within the limits given by the World Health Organization （WHO）. Although these samples were not biologically matched, linear mixed-effects statistical analyses permitted valid comparison of the groups. A subpopulation of 404 spermatozoa considered to fit the stringent criteria of WHO ‘normal＇ seminal spermatozoa from both semen and swim-up were characterized by median values （and 95% confidence intervals） of L, 4.3 μm （3.8-4.9）, W, 2.9 μm （2.6-3.3）, A, 10.2μm^2 （8.5-12.2）, P, 12.4μm （11.3-13.9）, Ac, 49% （36-60）, L/W, 1.49 （1.32-1.67） and P/A, 1.22 （1.11-1.35）. These median values fall within the 95th centile confidence limits given by WHO, but the confidence intervals for L and W were larger. Although these differences in head dimensions among men and after swim-up could be detected by CASMA, the small differences make it unlikely that technicians would be able to distinguish them. The values could be used as default sperm head values for the CASMA machine used here.     

精液保存和优化处理方法对精子DNA完整性的影响

目的:探讨不同精液保存和处理方法对精子DNA完整性的影响。方法:筛选2015年1~12月就诊的100例精液正常志愿者,将每例志愿者的精液混匀后分别对其进行不同的保存和优化处理;保存方法包括直接冷冻法、试剂冷冻法、室温保存4 h和24 h等,优化处理方法包括简单洗涤法、直接上游法和非连续密度梯度离心法。保存和处理后均采用精子染色体扩散实验(SCD)分析其精子DNA碎片指数(DFI);优化处理各组继续培养24 h,培养后再分析其精子活动率和DFI。结果:精液保存条件两两组间分析显示,直接冷冻法、试剂冷冻法和室温保存4 h的精子DFI分别为(27.3±6.4)%、(26.9±6.1)%和(24.7±6.8)%,结果无显著性差异(P0.05),而室温保存24 h则显著增加精子DFI[(35.6±9.0)%](P0.05)。与简单洗涤法的精子DFI[(13.7±2.0)%]相比,直接上游法的精子DFI[(9.1±1.3)%]和非连续密度梯度离心法的精子DFI[(8.0±2.5)%]均显著降低(P0.05);再培养24 h后,非连续密度梯度离心法处理的精子DFI[(11.5±4.2)%]最低(P0.05)。结论:保存条件和优化处理方法对精子DNA完整性有影响,临床工作中需选取最合适的精液处理方法。     

精液分析标准化的重要性与紧迫性

精液分析是一项十分重要的用于评估男性生殖能力的临床检验项目。然而,最近的报告提示精液分析的结 果并不可靠。男科学实验室的质控常常被认为是存在有问题的,在进行精液分析时许多实验室并不按常规进行质 量控制。质量保证工作在男科实验室常常被忽略。男科实验室室间检验能力验证计划还未被推广,最近几个项目 检测的结果表明,室间检验结果存在很大的变异。各实验室间执行着不同的标准使得一个实验室与另一个实验间 难以进行结果比对。通过执行以下几点建议可以获得可靠的精液分析结果:①所有实验室应该采用普遍接受的检 测标准和指标,②所有实验室应该参加室间测评计划,③实验室应该执行有效的室内质控和质量保证计划,以保证 报告结果准确和可重复,④临床医生应该指定患者在严格执行上述建议的实验室接受精液分析,或只认可这些实 验室提供的精液分析结果。     

The opening of maitotoxin-sensitive calcium channels induces the acrosome reaction in human spermatozoa： differences from the zona pellucida

The acrosome reaction (AR), an absolute requirement for spermatozoa and egg fusion, requires the influx of Ca²⁺ into the spermatozoa through voltage-dependent Ca²⁺ channels and store-operated channels. Maitotoxin (MTx), a Ca²⁺-mobilizing agent, has been shown to be a potent inducer of the mouse sperm AR, with a pharmacology similar to that of the zona pellucida (ZP), possibly suggesting a common pathway for both inducers. Using recombinant human ZP3 (rhZP3), mouse ZP and two MTx channel blockers ({"type":"entrez-nucleotide","attrs":{"text":"U73122","term_id":"4098075","term_text":"U73122"}}U73122 and {"type":"entrez-nucleotide","attrs":{"text":"U73343","term_id":"1688125"}}U73343), we investigated and compared the MTx- and ZP-induced ARs in human and mouse spermatozoa. Herein, we report that MTx induced AR and elevated intracellular Ca²⁺ ([Ca²⁺]_i) in human spermatozoa, both of which were blocked by {"type":"entrez-nucleotide","attrs":{"text":"U73122","term_id":"4098075","term_text":"U73122"}}U73122 and {"type":"entrez-nucleotide","attrs":{"text":"U73343","term_id":"1688125"}}U73343. These two compounds also inhibited the MTx-induced AR in mouse spermatozoa. In disagreement with our previous proposal, the AR triggered by rhZP3 or mouse ZP was not blocked by {"type":"entrez-nucleotide","attrs":{"text":"U73343","term_id":"1688125"}}U73343, indicating that in human and mouse spermatozoa, the AR induction by the physiological ligands or by MTx occurred through distinct pathways. {"type":"entrez-nucleotide","attrs":{"text":"U73122","term_id":"4098075","term_text":"U73122"}}U73122, but not {"type":"entrez-nucleotide","attrs":{"text":"U73343","term_id":"1688125"}}U73343 (inactive analogue), can block phospholipase C (PLC). Another PLC inhibitor, edelfosine, also blocked the rhZP3- and ZP-induced ARs. These findings confirmed the participation of a PLC-dependent signalling pathway in human and mouse zona protein-induced AR. Notably, edelfosine also inhibited the MTx-induced mouse sperm AR but not that of the human, suggesting that toxin-induced AR is PLC-dependent in mice and PLC-independent in humans.     

Insights into semen analysis： a Chinese perspective on the fifth edition of the WHO laboratory manual for the examination and processing of human semen

We are very glad to see that the Asian Journal of Andrology published a Special Issue on Semen Analysis in 21st Century Medicine, which well revealed some behind-the-scene controversies of the 5th edition of the WHO laboratory manual for the examination and processing of human semen [1]. Three articles from the special issue, two on the reference values of semen parameters [2, 3] and another presenting the investigation results of 118 laboratories performing semen analysis in Mainland China [4], are very thoughtprovoking and we would like to share some of our views on these topics.     

《世界卫生组织人类精液分析实验室技术手册》与我国男科实验室现状

2010年出版的《世界卫生组织人类精液分析实验室技术手册》第5版是最为全面的一次修订。本文结合我国男科实验室精液分析的现状,从包括精子计数、精子活力、精子形态学、精子功能、抗精子抗体和精浆生化、以及精液分析的质量保证与质量控制等7个方面,对新出版的WHO手册进行了评论。笔者认为,该手册对精子浓度分析方法和参考值下调的推荐缺乏循证医学依据;精子活力分级标准的修订和精子形态学的严格标准和较低的4%的正常参考值与我国男科实验室目前使用的标准差距较大;精子功能指标尚未完善;抗精子抗体和精浆生化指标的检测方法显然不适合我国男科实验室现状;但精液分析的质量保证和质量控制对我国男科实验室有重要指导作用。需要指出的是,WHO手册中并没有涉及来自占世界人口1/5的中国人的任何临床数据和资料。因此,尽管WHO手册非常重要,它能否适应中国人精液分析实验室参考,仍需要评估。     

The effectiveness and safety of acupuncture for poor semen quality in infertile males： a systematic review and meta-analysis

The aim of this review is to evaluate the effectiveness and safety of acupuncture for poor semen quality in infertile men. We searched for relevant trials registered up to May 2013 in 14 databases. We selected randomized controlled trials （RCTs） that compared acupuncture, with or without additional treatment, against placebo, sham, no treatment, or the same additional treatment. Two reviewers independently performed the study selection, data extraction, risk of bias and reporting quality appraisal. Risk of bias and reporting quality were appraised by the Cochrane risk of bias tool, the consolidated standards of reporting trials and Standards for Reporting Interventions in Clinical Trials of Acupuncture. The outcomes were sperm motility, sperm concentration, pregnancy rate, and adverse events. Pregnancy was defined as a positive pregnancy test. Four RCTs met the eligibility criteria. Acupuncture increased the percentage of sperm with rapid progression （mean difference - 6.35, 95% confidence interval （CI）. 4.38-8.32, P〈 0.00001） and sperm concentration （mean difference - 6.42, 95% CI. 4.91-7.92, P〈 0.00001）, but these two outcomes were substantially heterogeneous among the studies （F = 72% and 58%, respectively）. No differences in pregnancy rate were found between acupuncture and control groups （odds ratio 1.60, 95% CI. 0.70-3.69, P= 0.27, F = 0%）. No participants experienced adverse events. The current evidence showing that acupuncture might improve poor semen quality is insufficient because of the small number of studies, inadequacy of procedures and/or insufficient information for semen analysis, high levels of heterogeneity, high risk of bias, and poor quality of reporting. Further large, well-designed RCTs are required.     

Desmosterol,the main sterol in rabbit semen： distribution among semen subfractions and its role in the in vitro spermatozoa acrosome reaction and motility

Sterols are essential components of the cell membrane lipid bilayer that include molecules such as cholesterol and desmosterol, which are significantly found in the spermatozoa of several animal species. However, the presence of desmosterol in rabbit semen has never been investigated. The aims of this study were to characterize the sterol composition of subfractions of ejaculated rabbit semen and evaluate the in vitro effects of sterol on the spermatozoa acrosome reaction and motility. Two sterols, occurring prevalently in the free form （94.3%）, were identified in whole semen collected from 10 fertile New Zealand White rabbits, specifically desmosterol （58.5% of total sterols） and cholesterol （35.9% of total sterols）. Desmosterol was the predominant sterol found in all subfractions of rabbit semen, varying from 56.7% （in the prostatic secretory granules, PSGs） to 63.8% （in the seminal plasma）. Spermatozoa contained an intermediate proportion of desmosterol （59.8%）, which was asymmetrically distributed between the heads （52.0% of the total content of sterols） and the tails （81.8%）. Results showed that both desmosterol and cholesterol can be transferred from the PSGs to the spermatozoa and are equally effective in inhibiting in vitro spermatozoa capacitation at a concentration higher than 1 mg L^-1. In contrast, neither desmosterol nor cholesterol had a significant effect on spermatozoa motility. Thus, it was concluded that, the various fractions of rabbit seminal fluid differ from each other in sterol composition and quantity, probably due to their different functional properties, and these fractions may undergo significant sterol changes depending on the stage of spermatozoa capacitation.     

Semen analysis standardization： is there any problem in Polish laboratories？

The aim of the study was to determine the degree of compliance of Polish laboratories with World Health Organization （WHO） recommendations, with regard to semen analysis methodology. A survey requesting information about methods of semen analysis was distributed to employees of 55 laboratories. Respondents who had participated in external seminological workshops （31%） were termed certified respondents （CR）, the remaining （69%）--non-certified respondents （NCR）. Only one laboratory （6%） in the CR group and none in the NCR were compliant with WHO guidelines for methods and equipment used to evaluate seminal volume, sperm motility, concentration, vitality and morphology. Most problems were of volume measurement （weighing method was reported by 17% of CR and 10% of NCR） and staining method for sperm morphology （Papanicolau or Diff-Quik were found in 33% of CR and 23% of NCR）. A three- or four-point grading of sperm motility was used by the majority of respondents; however, 17% of CR and 37% of NCR did not use a laboratory counter to tally spermatozoa. Although a haemocytometer method was used by 80% of laboratories in each group, the improved Neubauer chamber was used only by 42% of CR and 19% of NCR. In each group, 24% of laboratories did not perform a vitality test. Procedural errors and the interchangeable utilization of two or even three methods to analyse a given parameter was observed in both groups. The results indicate a need for standardisation of the methods and continuous, unified training in semen analysis in Polish laboratories.     

Semen analysis with regard to and functional aspects sperm number,sperm morphology

The new World Health Organization （WHO） Manual for Semen Analysis contains several improvements. One is that the 20 million spermatozoa per mL paradigm has been ousted in favour of proper calculations of lower reference limits for semen from men, whose partners had a time-to-pregnancy of 12 months or less. The recommendation to grade the progressive motility as described in the third and fourth editions of the WHO manual was not evidence-based, and WHO was therefore motivated to abandon it. However, the new recommendation is not evidence-based either, and it is difficult to understand the rational for the new assessment. It may have been a compromise to avoid returning to the rather robust system recommended in the first edition （1980）. The unconditional recommendation of the ＇Tygerberg strict criteria＇ is not evidence-based, and seems to be the result of an unfortunate bias in the composition of the Committee in favour of individuals known to support the ＇strict criteria＇ method. This recommendation will have negative effects on the develop- ment ofandrology as a scientific field. Given the importance of the WHO manual, it is unfortunate that the recommenda- tions for such important variables, as motility and morphology, lack evidence-based support.     

Clinical significance of the low normal sperm morphology value as proposed in the fifth edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen

The very low cut-off value for sperm morphology of 4% morphologically normal spermatozoa, as proposed in the new edition of the World Health Organization （WHO） manual on semen analysis, is in agreement with recently published values and reflects the trend of a decline in reported mean values for normal sperm morphology. The reduced value for morphologically normal spermatozoa over the years may be due to several factors. The first is the introduction of strict criteria for the evaluation of sperm morphology. Other reasons may include the introduction of additional criteria for sperm morphology abnormalities and the suggested decrease in semen parameters because of increasing negative environmental influences. Although on its own the newly proposed very low normal value may not provide the strong predictive value for a males＇ fertility potential, as originally reported for sperm morphology evaluated according to strict criteria, a good predictive value can still be obtained if the holistic, strict approach for sperm morphology evaluation is followed together with additional sperm morphology parameters now available, because certain morphology patterns and sperm abnormalities are now known to be of strong prognostic value. In addition, better international standardization of the technical methodology, consensus on the interpretation of sperm morphology evaluation criteria and standardized international external quality control （EQC） schemes, are of utmost importance to maintain the good predictive value of sperm morphology.     

Clinical pregnancies and livebirths achieved by intracytoplasmic injection of round headed acrosomeless spermatozoa with and without oocyte activation in familial globozoospermia： case report

We report the successful outcome of intracytoplasmic sperm injection （ICSI） treatment in two siblings with familial globozoospermia. After controlled ovarian hyperstimulation and oocyte pick-up, retrieved oocytes were mechanically activated before ICSI and a fertilization rate of 33.3% was achieved in the first case. The second couple underwent ICSI without oocyte activation and a 9.1% fertilization rate was obtained. The transfer of two grade I embryos in the first couple and one grade I embryo in the second couple resulted in clinical pregnancies with healthy livebirths. It was concluded that the main problem of cases with globozoospermia is a low fertilization rate, and even though ICSI and oocyte activation can increase this rate it is not necessarily needed to achieve a pregnancy. （Asian J Androl 2008 Mar; 10： 332-336）     

Is number of chiasmata an etiological factor of male infertility？

Azoospermia and/or severe oligozoospermia can be treated as principal factors of male infertility. Specifically, azoospermia that stands for 1% of males and 10% of infertile male population has been mostly unexplained （idiopathic）, however, it is suspected for its genetic and/or molecular background？ Pertaining to molecular background of severe oligo-astheno-teratozoospermia （OAT） - the meiotic abnormalities are suspected to reach almost 20%.2 Therefore, this potentially addresses a significant number of cases that could find a possible etiological factor. Meiotic abnormalities as the authors point out encompass combination of anomalies in the process of pairing,     

按WHO《人类精液检查与处理实验室手册》第5版标准探讨精子形态对IVF-ET助孕结局的预测价值

目的:按WHO《人类精液检查与处理实验室手册》第5版(《WHO5》)标准探讨正常形态精子百分率对常规体外受精-胚胎移植的助孕结局及新生儿健康状况的预测价值。方法:采用《WHO5》标准把研究对象789例分为畸形精子症组(正常形态精子百分率<4%,35例)和正常组(正常形态精子百分率≥4%,754例),比较两组间正常受精率、卵裂率、优胚率、种植率、临床妊娠率、流产率及新生儿情况。结果:①两组间患者年龄(男、女方)、获卵数、女方平均身高及平均体重指数差异不显著(P>0.05);畸形精子症组的正常受精率、卵裂率、优胚率、周期冷冻率、种植率及移植周期妊娠率略低于正常组,而其流产率略高于正常组,但两组间各指标差异均无统计学意义(P>0.05);②除外继续妊娠(畸形精子症组1例,正常组140例),随访789个移植周期已分娩228个婴儿,畸形精子症组15个(9单胎+3双胎),正常组213个(141单胎+36双胎),出生婴儿无先天性缺陷,两组间孕周、早产率、低体重发生率差异均无统计学意义(P>0.05)。结论:按《WHO5》标准仅通过精子形态预测体外受精-胚胎移植的助孕结局及新生儿情况具有一定局限性。     

Status of semen analysis comment on “A survey on the status of semen analysis in 118 laboratories in China” by Jin-Chun Lu et al. in Asian Journal of Andrology

The paper by Lu et al. [1] ＂A survey on the status of semen analysis in 118 laboratories in China＂ provides a major review of the current methods of semen analysis in mainland China. It involved a 36-item questionnaire completed by technicians in 118 of a possible 145 potential semen laboratories. Recruitment for the study was via contacts developed at Chinese Andrology meetings and training sessions between 2005 and 2007. It is not stated how comprehensive this strategy would be for accessing all semen laboratories in China. About half the participating laboratories were in general hospitals and the others in hospitals with academic affiliations or family planning institutes.     

Infertility treatment, a matter of a lovely sperm？

Nowadays, the efficiency of the infertil-ity treatment is relatively low. One of the cues to counteract this problem relies on the optimum selection of spermatozoa. We developed a new method （sperm selection assay （SSA）） based on the chemical attrac-tion of spermatozoa that are at the best functional state. Additionally, the SSA leads spermatozoa to complete and/or acquire the competence to fertilize the egg. These effects are equally observed either in nor-mal or subfertile semen samples. Those cap-abilities of SSA may improve the success of current infertility treatment.