Sperm pretreatment with glutathione improves IVF embryos development through increasing the viability and antioxidative capacity of sex-sorted and unsorted bull semen

The antioxidant of reduced glutathione（GSH） is the most abundant thiol in cells for the maintenance of the intracellular redox balance. The study aimed to assay the effect of sperm treatment with GSH before incubation with oocytes on the development potential of embryos obtained by in vitro fertilization（IVF）. Also the mitochondrial membrane potential（ΔΨm）, plasma membrane integrity（viability）, DNA fragmentation, reactive oxygen species（ROS） content, superoxide dismutase（SOD）, catalase（CAT） and glutathione peroxidase（GPx） activities, methane dicarboxylic aldehyde（MDA） level as indices of lipid peroxidation in sex-sorted and unsorted sperm from three bulls were investigated using flow cytometry and enzyme-labeled instrument individually. The results showed that 2 mm ol L^–1 GSH increased significantly the cleavage rate（86.68% vs. 82.78%）, 4- to 8-cell rate（82.30% vs. 73.43%） and blastocyst rate（43.15% vs. 35.24%） of IVF embryos compared with untreated group. Furthermore, addition of GSH increased significantly the ΔΨm and viability, decreased the ratio of DNA fragmentation in sex-sorted or unsorted semen（P〈0.05）, except the sex-sorted semen from bull 019. Similarly, activities of SOD, CAT and GPx were increased significantly. However, the contents of MDA were decreased significantly both in sex-sorted and unsorted semen treated with GSH（P〈0.05）. These results suggest that sperm pretreatment with GSH during IVF can maintain better the viability and fertility of sperm through reducing apoptosis and increasing the antioxidant capacity, which improves the IVF embryos development.

Corrigendum: Activation of autophagy by Citri Reticulatae Semen extract ameliorates amyloid-beta-induced cell death and cognition deficits in Alzheimer’s disease

In the article titled“Activation of autophagy by Citri Reticulatae Semen extract ameliorates amyloid-beta-induced cell death and cognition deficits in Alzheimer’s disease”published on pages 2467-2479,Issue 11,Volume 19 of Neural Regeneration Research(Tang et al.,2024),there are some errors in selecting the appropriate images in Figure 7 by authors during assembling the images.

Activation of autophagy by Citri Reticulatae Semen extract ameliorates amyloid-beta-induced cell death and cognition deficits in Alzheimer’s disease

Amyloid-beta-induced neuronal cell death contributes to cognitive decline in Alzheimer’s disease.Citri Reticulatae Semen has diverse beneficial effects on neurodegenerative diseases,including Parkinson’s and Huntington’s diseases,however,the effect of Citri Reticulatae Semen on Alzheimer’s disease remains unelucidated.In the current study,the anti-apoptotic and autophagic roles of Citri Reticulatae Semen extract on amyloid-beta-induced apoptosis in PC12 cells were first investigated.Citri Reticulatae Semen extract protected PC12 cells from amyloid-beta-induced apoptosis by attenuating the Bax/Bcl-2 ratio via activation of autophagy.In addition,Citri Reticulatae Semen extract was confirmed to bind amyloid-beta as revealed by biolayer interferometry in vitro,and suppress amyloid-beta-induced pathology such as paralysis,in a transgenic Caenorhabditis elegans in vivo model.Moreover,genetically defective Caenorhabditis elegans further confirmed that the neuroprotective effect of Citri Reticulatae Semen extract was autophagy-dependent.Most importantly,Citri Reticulatae Semen extract was confirmed to improve cognitive impairment,neuronal injury and amyloid-beta burden in 3×Tg Alzheimer’s disease mice.As revealed by both in vitro and in vivo models,these results suggest that Citri Reticulatae Semen extract is a potential natural therapeutic agent for Alzheimer’s disease via its neuroprotective autophagic effects.

Exploring the relationship between ambient sulfur dioxide and semen quality parameters:A systematic review and meta-analysis

Objective:To investigate the relationship between ambient sulfur dioxide(SO2)exposure and semen quality parameters.Methods:A systematic literature search was conducted to identify relevant studies investigating the association between SO2 exposure and semen quality parameters.This search encompassed the timeframe from January 2000 to May 2023 and included electronic databases such as Web of Science,Google Scholar,PubMed,Cochrane,and Scopus.Pooled effect estimates with 95%confidence intervals(CI)were calculated using percent changes(PC).The meta-analysis included seven studies with 6711 participants and 15087 semen samples.Results:The results revealed a significant negative association between ambient SO2 exposure and certain semen quality parameters.In particular,SO2 exposure was associated with a significant decrease in progressive motility(PC=0.032;95%CI:-0.063 to-0.001;P=0.044)and sperm concentration(PC=-0.020;95%CI:-0.036 to-0.005;P=0.012).However,no statistically significant associations were observed for total sperm count(PC=-0.038;95%CI:-0.079 to 0.003;P=0.070),seminal fluid volume(PC=-0.009;95%CI:-0.048 to-0.030;P=0.662)and sperm motility(PC=-0.17;95%CI:-0.363 to 0.022;P=0.830).In addition,the results of the subgroup analysis revealed specific variables that were associated with the decrease in relevant sperm parameters.Conclusions:This systematic review and meta-analysis provides compelling evidence supporting a consistent negative association between exposure to ambient SO2 and semen quality parameters.

Adding chitosan nanoparticles of green tea extract in diluent and thawing temperatures ameliorate the post-thawed quality of Boer buck semen

Objective:To improve the quality of post-thawing Boer buck semen for artificial insemination by adding green tea extract chitosan nanoparticles to skimmed egg yolk diluent,and the proper thawing temperature.Methods:The ejaculate of Boer buck was added to skimmed egg yolk diluent without(the control group)and with adding 1μg of chitosan nanoparticles of green tea extract per mL of diluent(the treatment group).Then,the diluted semen was filled in French mini straws containing 60×106 live sperm per straw,frozen in a standard protocol,and stored as frozen semen at−196℃for a week.Six replicates from each group were diluted for 30 s at 37℃or 39℃sterile water to evaluate the semen quality.Results:Post-thawing(at 37℃or 39℃)of live sperm,progressive motility,and plasma membrane integrity were lower compared to those of the pre-freezing stage(P<0.05).Thawing at 37℃resulted in no significant difference in live sperm,progressive motility,and plasma membrane between the control group and the treatment group(P>0.05).The live sperm,progressive motility,and plasma membrane of the treatment group in the pre-freezing stage,and post-thawed at 39℃were higher compared to those of the control group(P<0.05).There was no significant difference in malondialdehyde(MDA)concentration,DNA fragmentation,and catalase concentration of thawing at 37℃compared to those of 39℃in the same group.The MDA concentration and DNA fragmentation in thawing at 37℃and 39℃of the treatment group were significantly lower than those of the control group(P<0.05).However,the catalase concentration in thawing at 37℃and 39℃of the treatment group was not significantly different than the control group(P>0.05).Conclusions:Higher quality post-thawing Boer buck semen is achieved by adding 1μg/mL of chitosan nanoparticles of green tea extract to the skimmed egg yolk diluent and thawing at 39℃.

Patterns of alteration in boar semen quality from 9 to 37 months old and improvement by protocatechuic acid

Background Comprehending the patterns of alteration in boar semen quality and identifying effective nutritional interventions are crucial for enhancing the productivity of commercial pig systems.This study aimed to examine the alteration in semen quality in boars,and assess the impact of protocatechuic acid(PCA)on semen quality during the phase of declining semen quality.Methods In Exp.1,a total of 38 Pig Improvement Company(PIC)boars were selected and their semen quality data were recorded from the age of 9 to 37 months.In Exp.2,18 PIC boars(28 months old)were randomly assigned into three groups(n=6)and fed a basal diet,a basal diet containing 500 or 1,000 mg/kg PCA,respectively.The experiment lasted for 12 weeks.Results The semen volume,concentration,and total number of spermatozoa in boars exhibited an increase from 9 to 19 months old and showed a significant linear decreased trend in 28,24,and 22 months old.Sperm motility displayed an upward trajectory,reaching its peak at 20 months of age,and showed a significant linear decreased trend at 20 months old.Dietary supplementation of PCA demonstrated an effect to mitigate the decrease in semen volume,concentration of spermatozoa,total number of spermatozoa(P>0.05),and significantly increased the sperm motility(P<0.05).Moreover,supplementation of 1,000 mg/kg PCA significantly increased the sperm viability(P<0.05).Analysis on cellular signaling pathways revealed that PCA restored serum testosterone levels and alleviated oxidative damage by upregulating the expression of HO-1,SOD2,and NQO1 in testicular stromal cells.Notably,PCA can enhance phosphorylation by selectively binding to AMP-activated protein kinase(AMPK)protein,thereby improving sperm mitochondrial function and augmenting sperm motility via PGC-1/Nrf1.Conclusions These data elucidated the pattern of semen quality variation in boars within the age range of 9 to 37 months old,and PCA has the potential to be a natural antioxidant to enhance sperm quality through modulation of the AMPK/PGC-1/Nrf1 signaling pathway.

Source and level of dietary iron influence semen quality by affecting inflammation, oxidative stress and iron utilization levels in boars

Background Boars fed a mixed form of inorganic and organic iron in excess of the NRC recommended levels still develop anemia,which suggested that the current level and form of iron supplementation in boar diets may be inappropriate.Therefore,56 healthy Topeka E line boars aged 15–21 months were randomly divided into 5 groups:basal diet supplemented with 96 mg/kg ferrous sulfate(FeSO_(4))and 54 mg/kg glycine chelated iron(Gly-Fe,control);80 mg/kg or 115 mg/kg Gly-Fe;80 mg/kg or 115 mg/kg methionine hydroxyl analogue chelated iron(MHA-Fe,from CalimetFe)for 16 weeks.The effects of dietary iron supplementation with different sources and levels on semen quality in boars were investigated.Results 1)Serum Fe and hemoglobin concentrations were not affected by reduced dietary iron levels in the 80 mg/kg or 115 mg/kg Gly-Fe and MHA-Fe groups compared with the control group(P>0.05).2)Serum interleukin-6(IL-6)and sperm malondialdehyde(MDA)levels in the 80 mg/kg or 115 mg/kg MHA-Fe groups were lower than those in the control group(P<0.05),and higher serum superoxide dismutase levels and lower MDA levels in the 115 mg/kg MHA-Fe group(P<0.05).3)Boars in the 80 mg/kg or 115 mg/kg Gly-Fe and MHA-Fe groups had lower serum hepcidin(P<0.01),ferritin(P<0.05),and transferrin receptor(P<0.01)concentrations,and boars in the 115 mg/kg MHA-Fe group had higher seminal plasma Fe concentrations compared with the control group.4)Boars in the 80 mg/kg and 115 mg/kg MHA-Fe groups had lower abnormal sperm rate and in situ oscillating sperm ratio compared to the control group at weeks 12 and/or 16 of the trial.However,the effect of Gly-Fe on improving semen quality in boars was not evident.5)Serum IL-6 level was positively correlated with hepcidin concentration(P<0.05),which in turn was significantly positively correlated with abnormal sperm rate(P<0.05).Furthermore,significant correlations were also found between indicators of iron status and oxidative stress and semen quality parameters.Conclusions Dietary supplementation with 80 mg/kg or 115 mg/kg MHA-Fe did not induce iron deficiency,but rather reduced serum inflammatory levels and hepcidin concentration,alleviated oxidative stress,increased body iron utilization,and improved semen quality in adult boars.

The Effects of Age and Ejaculatory Abstinence on Semen Quality and Reproductive Hormones in Africa and the Middle East

The aim of this study was to retrospectively evaluate the effects of male age and ejaculatory abstinence on semen parameters and reproductive hormones among men residing in Africa and the Middle East. A total of 70,142 semen analysis results were analysed and grouped according to the age intervals (16 - 20, 21 - 30, 31 - 40, 41 - 50, 51 - 60, >60) and ejaculatory abstinence (<2 days, 2 - 5 days and >5 days). Semen parameters i.e. volume, concentration, progressive motility, total progressively motile count, morphology, total normal sperm count, DNA fragmentation, viability, sORP, normed sORP were specifically evaluated. Additionally, for each age interval, reproductive hormones i.e. estradiol, luteinizing hormone, follicle stimulating hormone, testosterone and prolactin were evaluated. Semen volume, total progressively motile count, sperm morphology and total normal sperm count constantly decrease significantly after the age of 30 years. Sperm concentration started declining significantly after the age of 50 years. There was a constant age- related increase in number of spermatozoa with damaged DNA. sORP constantly increased up to 60 years. Furthermore, constantage-related decreases in FSH, serum testosterone and prolact in were observed from patients aged between 16 years and 60 years. Semen volume, sperm concentration, progressive motility and normal morphology were significantly higher in patients having > 5 days of abstinence. Patients having > 5 days of abstinence had the lowest normed sORP. Male age significantly affects sperm parameters and reproductive hormones in fertile and infertile men residing in Africa and the Middle East. Prolonged abstinence days provides better semen quality.

Effect of Moringa oleifera on semen quality profiles in endangered Teressa goat under tropical humid island ecosystem

Objective:To investigate the effect of Moringa oleifera leaf extract on semen quality parameters in Teressa goat buck.Methods:A total of 25 semen samples from six bucks were selected for the study.Spermatozoa of 150×10^(6) were incubated in 0,300,500 and 700μg of leaf extract as groupⅠ,Ⅱ,Ⅲ and Ⅳ,respectively.Liquid stored semen samples were analysed for motility,viability,total sperm abnormalities,plasma membrane,acrosomal and nuclear integrities,seminal plasma intracellular enzymes[aspartate aminotransferase(AST),alanine aminotransferase(ALT)and lactate dehydrogenase(LDH)]and total antioxidant capacity(TAC)and spermatozoa malondialdehyde(MDA)and cholesterol efflux in comparison with the control group(groupⅠ)for up to 72 h.Results:Moringa oleifera leaf extract(500μg/150×10^(6) spermatozoa)-treated semen had significantly higher motility,viability,plasma membrane,acrosomal and nuclear integrities,and TAC(P<0.05),and had significantly lower total sperm abnormalities,AST,ALT,LDH,MDA production and cholesterol efflux compared to those in other Moringa oleifera leaf extract treated(300 or 700μg/150×10^(6) spermatozoa)and control groups at different hours of liquid storage(P<0.05).Semen quality parameters and TAC showed an increasing trend and total sperm abnormalities,MDA production,leakage of intra-cellular enzymes and cholesterol efflux showed a decreasing trend from group Ⅰto group Ⅲand then an opposite trend from group Ⅲ to group Ⅳ at different hours of liquid storage.Conclusions:Moringa oleifera leaf extract 500μg/150×10^(6) spermatozoa can be used for liquid semen preservation in Teressa goat at Andaman and Nicobar Islands.

Study on the Quality of Boar Semen in Kandal Province,Cambodia

In pig production,the selection of parent stock with high capacity and quality is a very important factor in order to obtain high-yield offspring.Therefore,a“study on the quality of boar semen in Kandal province”was conducted for the purpose of comparing and evaluating the quality of boar semen(VAC:Volume Activity Concentration)between Duroc breeds,Yorkshire breeds and Landrace breeds.The study was carried out according to an observation study by selecting three breeds of boars around 3 years old,including two Duroc,two Yorkshire and two Landrace.Each boar was observed in three months,three times a month,and the interval was three to four days.The study took place in Takhmao City,Kandal Province,Cambodia.The results showed that the semen volume per ejaculate per head obtained from Yorkshire boar was an average of 250±76.16 mL,which was higher than the semen volume of Landrace with an average of 173.33±59.73 mL.And the semen volume of Duroc was an average of 149.44±72.70 mL.This value indicates that the semen volume per ejaculate per head was significantly different(p<0.01).The activity or mobility of spermatozoa in the semen between the three breeds differed with slightly significant difference(p<0.05),with the spermatozoa scored from the Yorkshire being 0.76±0.06,Landrace being 0.79±0.05 and Duroc being 0.83±0.03.The semen concentration showed that the Yorkshire had an average spermatozoa concentration of 568.89×10^(6) sperm cells/mL,and the Landrace had an average spermatozoa concentration of 321.11×10^(6) sperm cells/mL and the Duroc an average spermatozoa concentration of 568.86×10^(6) sperm cells/mL,which further confirmed that there was a significant difference in the statistical meaning(p<0.001).The semen quality(VAC)per one ejaculate between the three breeds showed significant difference(p<0.05),in which the VAC of the Yorkshire was 39.31×10^(9) sperms per ejaculate,Landrace was 44.54×10^(9) sperm cells per ejaculate and Duroc was 70.28×10^(9) sperm cells per ejaculate.Based on the above results,we can conclude that the semen quality(VAC)values of the three breeds of pigs are good,which can save the breeding because it shows the excellent quality of each breed.

Study on the regulatory effect of liver X receptor in HEK293 cells by six main diterpene esters in Semen Euphorbiae

Background:To study the effects of the main diterpene esters in Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)on the transcriptional activity and protein expression of liver X receptor(LXR).Methods:The effect of the main diterpene ester components in Semen Euphorbiae on the viability of HEK293 cells were studied by MTT assay.The LXR-Luc plasmid vector was transfected into HEK293 cells and treated with Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)for 24 h.The effect of the main diterpene ester components of Semen Euphorbiae on LXR-Luc luciferase activity was investigated by dual luciferase reporter gene system,and the expression of LXRαprotein was detected by Western Blot.Results:Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)could significantly reduce the relative luciferase activity(RLU)of LXRα,and the expression level of LXRαprotein was significantly down-regulated.Conclusion:Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)can inhibit the expression of LXR protein level,which may be achieved by inhibiting the transcriptional activity of LXR.

Changes in Blood and Semen Quality of Bulls after Artificial Infection with Mycoplasma wenyonii

[Objective]This study aimed to investigate the effects of Mycoplasma wenyoni on blood and semen quality of breeding bul s. [Method] Ten 10 healthy breeding bul s of Luxi cattle were randomly divided into two groups. Breeding bul s in experimental group were injected intravenously with M. wenyoni on Day 0 and Day 28. Effects of Mycoplasma wenyoni on breeding bul s were evaluated compre-hensively based on clinical symptoms, blood smears, blood physiological and bio-chemical properties, semen quality and scrotal changes. [Result] In addition to indi-vidual indices, the experimental group exhibited basical y normal clinical examination results without significant abnormal blood and semen quality. [Conclusion] This study suggests that M. wenyoni has low virulence and pathogenicity to breeding bul s af-ter artificial infection, leading to no significant changes in blood and semen quality.

精囊凝胶蛋白Semenogelin Ⅰ的研究进展

精液的凝固和液化过程亦是精子获能的过程,是精子取得前向运动所必需的。射精后的人类精液最初呈凝固状态,主要是由于精囊特异性分泌的精液凝胶蛋白SemenogelinⅠ(SgⅠ)的作用,在随后精液液化过程中被前列腺分泌的前列腺特异性抗原(PSA)水解,产生许多相对分子质量较小的具有各种生物学活性的肽段,这些肽段被发现存在于精子的表面或被精子利用,调控精子获能和向前运动的能力。文中对SgⅠ的生理功能研究进展进行了综述。

酸枣仁提取物调控miR-7b-3p/5-羟色胺1A受体表达促进骨生长

背景:前期研究发现,酸枣仁提取物通过提高脑组织5-羟色胺1A受体(serotonin 1A receptor,5-HT1AR)表达,使之与5-羟色胺结合,延长小鼠慢波睡眠,促进生长激素的分泌,从而使骨生长。5-HT1AR作为一种蛋白质,其表达丰度受到miRNA的调控。作者推测酸枣仁提取物可能通过miRNA调控5-HT1AR的表达从而发挥药物作用。目的:观察酸枣仁提取物通过干预小鼠脑组织中miR-7b-3p/5-HT1AR通路对骨骼生长的影响。方法:①将昆明种小鼠分为正常对照组、用药组(灌胃酸枣仁提取物0.320 mg/g),阳性对照组(灌胃酸枣仁皂甙0.013 mg/g)和酸枣仁提取物+5-HT1AR抑制剂组(灌胃酸枣仁提取物最后3 d同时每天侧脑室注射5-HT1AR选择性抑制剂P-MPPF 8μg),25 d后观察酸枣仁提取物对小鼠骨生长、血清生长激素水平及脑组织5-HT1AR表达的影响;②基因芯片法筛选由酸枣仁提取物引起的骨生长小鼠与普通小鼠脑组织差异表达的miRNAs,并通过PCR验证和双荧光素酶报告基因实验证实筛选的miR-7b-3p与5-HT1AR的调控关系;③体外培养小鼠脑皮质细胞并鉴定,利用Western blot法观察酸枣仁提取物对脑皮质细胞中5-HT1AR表达的影响;④将昆明种小鼠分为正常对照组、用药组、miR-7b-3p inhibitor组、用药+miR-7b-3p mimics组、阳性对照组,观察各组小鼠脑组织5-HT1AR表达及5-羟色胺与5-HT1AR结合活性;⑤将SD大鼠分为正常对照组、用药组、miR-7b-3p inhibitor组、用药+miR-7b-3p mimics组、阳性对照组,观察各组大鼠慢波睡眠的变化。结果与结论:①酸枣仁提取物可以促进小鼠体长、胫骨增长,促进生长激素分泌,提高脑组织5-HT1AR含量;②基因芯片筛选出差异表达的miRNAs个数为16个,其中上调有13个,下调有3个;生物信息学预测下调miR-7b-3p可以调控5-HT1AR表达,且双荧光素酶报告基因实验证实二者有直接调控关系;③酸枣仁提取物和沉默脑皮质细胞中miR-7b-3p表达可以引起5-HT1AR高表达;沉默miR-7b-3p后小鼠脑组织5-HT1AR表达、5-羟色胺与5-HT1AR结合活性及生长激素分泌均升高;过表达miR-7b-3p后小鼠脑组织5-HT1AR表达、5-羟色胺与5-HT1AR结合活性及生长激素分泌均降低;大鼠慢波睡眠期也相应延长或缩短。结果表明,酸枣仁提取物能够降低脑组织的miR-7b-3p水平,同时增加5-HT1AR的表达量。这种机制有助于延长慢波睡眠周期,并且促进生长激素的生成,对骨骼生长有积极影响,为使用酸枣仁提取物作为促进骨骼生长的潜在手段提供了科学依据。

Association of 25-hydroxy-vitamin D levels with semen and hormonal parameters

Vitamin D levels have been linked to various health outcomes including reproductive disorders. The purpose of this study was to explore the association between serum vitamin D level （25-hydroxy-vitamin D, or 250HD） and semen and hormonal parameters. This is a cross-sectional study that included 170 healthy men recruited for the study of spermatogenesis from the general population. Men completed general and reproductive health questionnaires, and donated blood and semen samples. The main measures were hormonal （total and free testosterone, sex hormone-binding globulin, estradiol, follicle-stimulating hormone and luteinizing hormone） and semen parameters, adjusted （n= 147） for age, body mass index （BMI）, season, alcohol intake and smoking, in relation to categories of vitamin D levels, determined apriori. The mean age of the study population was 29.0±8.5 years and mean BMI was 24.3±3.2 kg m-2. The mean 250HD was 34.1± 15.06 ng m1-1. BMI showed a negative association with 250HD. Sperm concentration, sperm progressive motility, sperm morphology, and total progressively motile sperm count were lower in men with ‘250HD ≥ 50 ng ml-1＇ when compared to men with‘20 ng ml-1 ≤ 250H D〈 50 ng ml-1,. Total sperm count and total progressive motile sperm count were lower in men with ‘250HD〈20 ng ml-1＇ when compared to men with‘20 ng ml-1≤250HD〈50 ng ml-1＇. The adjusted means of various hormonal parameters did not show statistical difference in the different categories of 250HD. In conclusion, serum vitamin D levels at high and low levels can be negatively associated with semen parameters.

A survey on the status of semen analysis in 118 laboratories in China

Collecting baseline information on how laboratories perform testing is a reasonable first step towards establishing intra- and inter-laboratory standardization and quality control for semen analysis. We carried out a survey of the laboratories performing the testing in China's Mainland. A questionnaire, composed of 36 questions covering all aspects of semen analysis, was designed, and a copy was distributed to each of the 145 laboratories. Of these, 118 laboratories completed the questionnaires. The survey results showed that semen volume was measured visually in 53.6% （59/110） of the responding laboratories, and 70.9% （73/103） of laboratories analysed incompletely liquefied semen without any treatment. In addition, both manual-microscopic and computer-assisted semen-analysis systems were applied to analyse sperm concentration, motility and morphology. However, more than five methods were employed in routine sperm staining. An enzyme-linked immunosorbent assay was commonly used for determining whether antisperm antibodies were present. Several seminal biochemical markers were analysed in only 27.1% （32/118） of the responding laboratories. Generally, there was a lack of intra- and inter-laboratory quality control measures for semen analysis in all laboratories responding to this survey. In conclusion, the methods of semen analysis and the interpretation of test results in the surveyed laboratories differed markedly. In particular, many laboratories employed methods other than those recommended by the World Health Organization Laboratory Manual for the Examination of Human Semen and Sperm- cervical Mucus Interaction （1999）. These findings suggest an urgent need for the standardization of semen analysis with acceptable quality controls for each parameter to make the results repeatable and meaningful.

Does exposure to computers affect the routine parameters of semen quality?

Aim： To assess whether exposure to computers harms the semen quality of healthy young men. Methods： A total of 178 subjects were recruited from two maternity and children healthcare centers in Shanghai, 91 with a history of exposure to computers （i.e., exposure for 20 h or more per week in the last 2 years） and 87 persons to act as control （no or little exposure to computers）. Data on the history of exposure to computers and other characteristics were obtained by means of a structured questionnaire interview. Semen samples were collected by masturbation in the place where the semen samples were analyzed. Results： No differences in the distribution of the semen parameters （semen volume, sperm density, percentage of progressive sperm, sperm viability and percentage of normal form sperm） were found between the exposed group and the control group. Exposure to computers was not found to be a risk factor for inferior semen quality after adjusting for potential confounders, including abstinence days, testicle size, occupation, history of exposure to toxic substances. Conclusion： The present study did not find that healthy： men exposed to computers had inferior semen quality. （Asian J Andro12005 Sep; 7： 263-266）

Do Ureaplasma urealyticum infections in the genital tract affect semen quality?

Aim： To investigate the relationship between Ureaplasma urealyticum （UU） infection and semen quality. Methods： From 2001 to 2003, 346 eligible patients aged 20-45 years were invited from two hospitals in Shanghai, China, to participate in an investigation which included questionnaires about general and reproductive health, an external genital tract examination, UU culture and semen analysis. Multiple linear regression models were used to examine whether UU had a significant effect on semen quality after adjustment for confounding factors. Results： Findings suggested that UU infection was associated with higher semen viscosity and lower semen pH value. Sperm concentration was lower in UU positive subjects than that in UU negative subjects （54.04 × 10^6/mL vs.70.58 × 10^6/mL）. However, UU did not significantly affect other semen quality indexes. Conclusion： UU infection of the male genital tract could negatively influence semen quality.

Semen quality analysis and the idea of normal fertility

The World Health Organization （WHO） has extensively revised its manual for semen analysis, and seeks to provide reference limits for semen quality parameters. This raises the question of what is meant by ＇normal＇ （excluding the use of this term to denote a Gaussian distribution）. It could be taken in a purely statistical sense, using a biologically arbitrary cut-off point to denote an abnormal level, typically the extreme 5 percent of the population. Alternatively, ＇normal＇ could be defined according to the biological concept of normality and abnormality, in terms of the point at which biological function becomes impaired. Either of these can be used in descriptive epidemiology, for example, to study trends, but in the case of fertility, both semen quality and functional fertility （time to pregnancy） are continuous variables with no clear threshold. The WHO manual uses the biological meaning of normal, in that it provides the semen parameter distributions for men who have recently fathered pregnancies that took 12 months or less to conceive. However, what is really needed is the same information the other way around： given a particular semen test result, what should be expected in terms of ability to conceive, and how long it is likely to take. In considering epidemiological research, the focus has been mainly on internal comparisons, rather than reference limits, but it would be beneficial if more attention were paid to the absolute levels and to what these mean in terms of function--in other words, if the data were better calibrated biologically.

精液凝固蛋白Semenogelin对精子运动抑制机制的研究进展

精液的液化和精子的获能是精子取得向前运动的关键,精液凝固蛋白Semenogelin(Sg)在这个过程中起着至关重要的作用,它们直接参与了精液凝胶的形成,并协同其他一些来源于男性生殖道的蛋白酶类和金属离子等,与精子细胞表面发生作用,参与调控精液液化和精子获能,最终使精子取得向前运动。本文综述了当前Sg对精子活动抑制机制的研究进展。