新型超声快速处理活检标本保存不同年限对DNA质量的影响

背景:新型超声组织处理技术越来越多地被用来进行分子生物学分析,研究新型超声处理不同存储年限组织DNA的质量,对进一步分子检测的标本质控具有重要意义。目的:探讨新型超声处理活检标本存储不同年限对DNA质量的影响,以期为分子检测探索最佳的标本存储时间。方法:收集40例乳腺穿刺小活检组织,采用超声技术制作石蜡标本,按照存储年限分为4组:<1年组、1-3年组、>3-5年组及>5年组,每组10例,对石蜡标本进行切片,每张切片厚3μm,切片10-15张,提取DNA后通过Nanophotometer N60超微量分光光度计和Qubit 4.0荧光计检测DNA的质量浓度,记录A_(260)/A_(280)比值判定DNA的纯度,利用全自动毛细管电泳核酸分析仪(Qsep 100)检测DNA片段完整性,以评估DNA片段的质量。结果与结论:4组样本A_(260)/A_(280)均值在1.8-2.0之间,达到纯度要求,无明显差异。4组样本的DNA质量浓度(Qubit浓度)均值分别为30.39,14.33,2.52,1.95 ng/μL;DNA的平均N/Q比值分别为6.48,14.18,24.56,29.86;DNA质量数均值分别为5.64,1.76,1.24,0.80;大片段占比均值分别为56.08%,17.72%,12.68%,7.90%。PCR检测内控基因Ct均值分别为15.32,17.09,18.39,21.24。与<1年组相比,其余3组DNA浓度显著降低,N/Q比值显著增加,DNA质量数和大片段占比均值显著降低,Ct值升高,差异有显著性意义(P<0.05)。实验结果表明,对于新型超声处理活检标本,应优先选择存储<1年的样本进行日常分子检测,储存3年内的样本可满足二代测序等检测要求,5年内样本仅可尝试进行PCR等检测,存储超过5年的样本不建议进行后续分子检测。

基于中医证候与精液质量相关参数构建精子DNA碎片预测模型与验证

背景:中医证候与精液质量相关参数相结合,共同预测精子DNA碎片指数(DNA fragmentation index,DFI)异常增高的发生并绘制列线图,能显著提高临床的实操性与应用效能,为临床全面评估精液质量,采取积极干预措施以改善临床结局及制定个体化医疗方案提供依据。目的:探讨基于中医证候与精液质量相关参数构建精子DNA碎片的预测模型与验证。方法:回顾性分析2019年7月至2021年7月在广西壮族自治区南溪山医院中医男科接受中医证候诊断及精子DNA碎片率检查的不育患者共420例,据《人类精液检查与处理实验室手册》(第6版),将其中137例精子DFI>30%患者纳入精子DFI异常增高组,将283例精子DFI≤30%作为对照组;首先采用单因素分析筛选精子DFI异常增高的影响因素,然后采用套索算法(LASSO)校正因子共线性问题并筛选出最佳匹配因子后,将其纳入多因素向前逐步Logistic回归找出其独立影响因素并绘制列线图,最后采用受试者工作曲线、校准曲线、临床决策曲线、临床影响曲线对该预测模型进行区分度与准确度及临床应用效能验证。结果与结论:①单因素分析结果显示,年龄、体质量指数、前向运动率、精子总活率、精子浓度、精子形态学、肾阳虚衰证、湿热下注证、肾精不足证为引发精子DFI异常增高的影响因子(P<0.05);②通过LASSO回归进一步筛选出的最佳匹配因素为年龄、体质量指数、精子总活率、精子浓度、精子形态学、肾阳虚衰证、湿热下注证、肾精不足证(P<0.05);③多因素向前逐步Logistic回归结果显示年龄、体质量指数、精子浓度、精子总活率、湿热下注证、肾阳虚衰证共6项为引发精子DFI异常增高的独立影响因素;④受试者工作曲线显示,模型组曲线下面积为0.760(0.713,0.806),验证组曲线下面积为0.745(0.714,0.776),说明该预测模型具有较好的区分度;⑤校准曲线平均绝对误差0.040,Hosmer-Lemeshow检验P>0.05,表明该模型预测发生精子DFI异常增高的概率与实际发生精子DFI异常增高的概率无显著统计学差异,证实该模型具有较好的准确度;⑥临床决策曲线与临床影响曲线显示,模型组与验证组分别在阈概率值为0.08-0.84与0.09-0.78时具有临床最大净获益,且在该阈概率范围内具有较好的临床应用效能;⑦结果表明,年龄、体质量指数、精子浓度、精子总活率、湿热下注证、肾阳虚衰证为引发精子DFI异常增高的独立影响因素,通过其构建的临床预测模型列线图具有较好的临床预测价值与临床应用效能,可为临床全面评估精液质量、预后与干预及个体化医疗服务提供依据。

The relationship between DNA fragmentation and the intensity of morphologically abnormal human spermatozoa

Objective:To determine the relationship between teratozoospermia and sperm DNA fragmentation(SDF)in the human ejaculate.Methods:This retrospective study included 100 normozoospermic men as a control cohort(abnormal forms>14%),210 patients with a high level of abnormal forms(≤4%)and 65 patients presenting with a moderate level of abnormal forms(>4%to≤14%)based on the World Health Organization definitions.Sperm morphology was assessed using bright field microscopy.Sperm DNA fragmentation was assessed using the sperm chromatin dispersion assay.Non-parametric analyses were conducted to examine the relationship between abnormal sperm morphology and sperm DNA fragmentation;receiver operating characteristic(ROC)analyses were conducted to assess sensitivity and specificity of this relationship.Results:A correlation analysis revealed that the higher the proportion of abnormal spermatozoa in the ejaculate,the higher the level of SDF(Spearman's Rho=-0.230;P<0.001).Significant differences in the proportion of SDF were found when all cohorts were compared(P<0.001);these significant differences were also retained when the different cohorts were compared pairwise.ROC analysis showed a moderate but significant predictive value for SDF to differentiate patients with different levels of teratozoospemia.Conclusions:Although analysis of a more continuous range of values for teratozoospermia would help further clarify any causal relationship with SDF,there is clearly a synergistic or coincident affiliation between these variables that needs to be acknowledged by the clinician when interpreting the spermiogram.

基于活产建立体外受精-胚胎移植精子DNA碎片指数的参考阈值及子代短期安全性

背景:精子DNA碎片指数与受精、胚胎发育潜能、胚胎植入、流产及子代安全性等存在显著的相关性。然而,其临床参考值受多种因素的影响,导致临床意义极其有限,该研究以活产为结局,通过倾向评分匹配校正其他混杂因素后,构建精子DNA碎片指数与活产的最佳临床截断值,并对其进行内外部验证,具有较好的预测价值及临床应用效能。目的:探讨基于活产建立体外受精-胚胎移植精子DNA碎片指数的参考阈值及子代短期安全性。方法:选取2019年5月至2021年5月于常州市妇幼保健院接受体外受精-胚胎移植患者1921例,以倾向匹配容差0.02为标准,1∶1进行倾向评分匹配,结果活产组与非活产组各成功匹配540例,以此建立模型组;通过选取同时期广西壮族自治区南溪山医院接受体外受精-胚胎移植患者135例作为外部验证组;采用受试者工作曲线探求精子DNA碎片指数对活产的临床最佳截断值,分别采用限制性立方样条曲线、标准曲线、临床决策曲线、临床影响曲线及内外部验证等方法,对该截断值的准确性及临床应用效能进行评估。结果与结论:(1)非活产组精子DNA碎片指数显著高于活产组且与活产存在显著的负相关性(r=-0.444,P<0.001);(2)受试者工作曲线结果显示,DNA碎片指数对活产的最佳截断值为24.33%,曲线下面积为0.775(0.746,0.804),特异度为72.60%,敏感度为78.90%,准确度为75.70%;(3)限制性立方样条曲线拟合Logistic回归结果显示,当精子DNA碎片指数大于24.57%时,临床非活产的风险呈趋势性增涨;(4)Logistic回归概率分析结果显示,精子DNA碎片指数为活产的危险因素[OR(95%CI)=0.916(0.904,0.928),P<0.001],且当精子DNA碎片指数大于27.78%时,临床活产发生的概率将小于50%,随着精子DNA碎片指数每增高1个单位,活产的概率下降8.4%;(5)内外部对该临床截断值的验证均显示,该截点具有一定的临床预测价值及准确性;(6)临床决策曲线与临床影响曲线显示,以该临床截断值建立的预测模型在阈概率为0.22-0.73时具有临床最大净获益值,且在该阈概率范围内损失与获益的比值始终小于1,证实该预测模型具有较好的临床应用效能;(7)精子DNA碎片指数与子代短期安全性分析结果显示,精子DNA碎片指数与出生儿早产、体质量、畸形、性别差异无显著性;(8)结果表明,精子DNA碎片指数对体外受精-胚胎移植活产的最佳临床截断值为24.33%,以此建立的临床预测模型具有较好的区分度、准确度与临床应用效能,精子DNA碎片指数对子代短期安全性影响并不显著,但仍需大样本及长期的追踪评估。

辅助生殖技术中精子DNA损伤的研究现状

精子DNA完整性对受精卵的形成至关重要,精子DNA损伤可能影响辅助生殖技术(assisted reproductive technology,ART)的成功率。精子DNA损伤主要包括单链和双链损伤,这些损伤可能在受精、胚胎质量和着床能力等多个方面影响ART的成功率。精子DNA损伤的因素主要包括氧化应激、年龄、激素以及环境等。同时,卵母细胞对精子DNA损伤的修复能力也至关重要。目前临床和实验室主要通过药物干预、优化精子选择来降低精子DNA碎片指数(DNA fragmentation index,DFI),从而改善ART的临床治疗结局。综述精子DNA损伤的研究现状,分析其对ART治疗结局的影响,并提出了可能的改进精液制备方法。

精浆氧化还原电位与精子DNA碎片指数、高DNA着色性及运动参数的相关性研究

目的研究精浆氧化还原电位(ORP)和归一化氧化还原电位(nORP)与精子DNA碎片指数(DFI)、高DNA着色性(HDS)及运动参数的相关性,探讨其是否能作为评估男性生育潜能的生物标志物。方法选取2023年10月至12月于中国人民解放军北部战区总医院生殖医学科男科门诊就诊的309例男性作为研究对象。采用电极法检测精浆ORP、nORP,分析其与DFI、HDS、年龄、禁欲时间、精液量、精子总数、精子浓度、前向运动精子数、前向运动精子百分率、非前向精子数、非前向精子百分率、不动精子数、不动精子百分率、精子活动率、曲线速度(VCL)、直线速度(VSL)、平均速度(VAP)、线性指数(LIN)、直性指数(STR)及振动指数(WOB)的相关性;对nORP结果进行三等分,比较其与上述参数的差异。采用广义线性回归探讨nORP与HDS的关系,同时生成HDS与nORP的平滑曲线拟合。结果Pearson相关性及Spearman相关性分析显示,ORP和nORP均与精液量、不动精子百分率及DFI呈正相关,与前向运动精子数、前向运动精子百分率、精子活动率、VSL、VAP呈负相关(P<0.05);不同的是ORP还与禁欲时间、不动精子数呈正相关(P<0.05),与LIN、STR及WOB呈负相关(P<0.05),而nORP还与HDS呈正相关(P<0.05),与精子总数、精子浓度、非前向精子数、非前向精子百分率、不动精子数、VCL呈负相关(P<0.05)。nORP分组结果显示,精液量、精子总数、精子浓度、前向运动精子数、前向运动精子百分率、非前向精子数、非前向精子百分率、不动精子数、不动精子百分率、精子活动率、VCL、VSL、VAP、DFI、HDS组间比较差异有统计学意义(P<0.05);将nORP与HDS制作曲线拟合,对年龄及禁欲时间进行了调整。随着HDS的增加,nORP呈线性上升趋势。结论ORP、nORP都与精子DFI和主要运动参数相关,但nORP还与代表精子成熟度的HDS相关,更能反映精液质量,可作为评估男性生育潜能的生物标志物。

中年男性精子DNA碎片率对体外受精-胚胎移植妊娠结局的影响

目的探讨中年男性精子DNA碎片率(DFI)与精液质量和体外受精-胚胎移植妊娠结局的关系。方法共收集180例接受常规体外受精-胚胎移植治疗且男性年龄>38岁的精液标本。根据DFI的阈值分成(<30%和≥30%)两组。主要测量指标包括:常规精液参数、激素水平、DFI、受精率、优质胚胎率、临床妊娠率等。结果通过比较分析发现,DFI与男性卵泡刺激素(FSH)、精子活力、精子形态密切相关,且精子活力随着DFI水平的升高而下降(P<0.05);当DFI≥30%时,优质胚胎率下降(P<0.05),但两组的临床妊娠率差异无显著性(P>0.05)。结论DFI可以作为中年男性精液常规分析的重要参考指标,虽然DFI影响优质胚胎率,但与辅助生殖治疗的临床妊娠结局无关。

精液优化处理后DNA碎片指数与IVF-ET胚胎质量及妊娠结局的关系

目的:评估经密度梯度离心联合上游法优化处理后的精子DNA碎片指数(DFI)与辅助生殖体外受精-胚胎移植(IVF-ET)胚胎质量及妊娠结局的关系。方法:回顾性分析2022年4月至12月在郑州大学第一附属医院生殖医学中心因单纯输卵管因素行IVF-ET的257个周期,比较男方精液优化前后精液参数和精子DFI;按优化后精子DFI将其分为高DFI组(DFI>5)与低DFI组(DFI≤5),比较两组的胚胎发育及妊娠结局;根据临床妊娠情况分为妊娠组与非妊娠组、持续妊娠组及早期流产组,比较精子DFI情况。结果:与处理前相比,精液优化处理后前向运动精子及正常形态精子百分比提高,精子DFI下降(P<0.001)。精子优化处理后高DFI组的早期流产率高于低DFI组(P<0.05)。105例临床妊娠周期中早期流产组精液优化处理前、后DFI均高于持续妊娠组(P<0.05)。结论:密度梯度离心联合上游优化处理是一种有效的精液制备方法,可提高精子前向运动能力和正常形态精子比例,降低精子DFI;优化后精子高DFI可能增加临床妊娠后早期流产的风险。

生殖道解脲支原体感染及男性年龄对精子DNA碎片指数、精液常规参数的影响

目的探讨生殖道解脲支原体(Uu)感染及男性年龄对精子DNA碎片指数(DFI)及精液常规参数的影响。方法收集2019年1月至2023年7月于深圳市宝安区妇幼保健院体检科和生殖健康科进行婚前或孕前保健检查的男性7106例为研究对象,所有研究对象进行精液常规参数检查,并采用培养法和流式细胞术分别进行精液Uu检测与精子DFI分析。依据年龄截点将研究对象分成3组(<30岁、30~35岁、>35岁),分析Uu检出情况及Uu阳性男性中不同年龄组间精液常规参数和精子DFI差异。结果近5年男性生殖道Uu总体检出率为11.89%(845/7106),除2020年检出率略有下降外,整体呈逐年上升趋势;生殖道Uu检出率无明显的年龄和季节性差异。Uu阳性男性不同年龄组间比较发现,相比<30岁和30~35岁组,>35岁组的精子存活率、前向运动精子百分率、精子总数显著降低(P<0.05),精子DFI显著增高(P<0.05)。Uu阳性男性年龄与精子DFI呈正相关关系(r=0.26,P=0.0002)。Logistic回归分析结果显示,年龄[OR=1.393,95%CI(1.002,1.935),P=0.040]、精子存活率[OR=0.746,95%CI(0.608,0.916),P=0.005]和精子总数[OR=0.984,95%CI(0.968,0.999),P=0.040]是Uu阳性男性精子DFI的独立影响因素(P<0.05)。结论生殖道Uu阳性的高龄男性精液常规参数欠佳,且精子DFI显著增加。Uu检测可作为孕前男性精液质量筛查的候选指标,为全面客观评价男性生育力提供更多实验室证据。

基于氧化应激效应探讨精索静脉曲张患者显微结扎术对精子DNA碎片及试管婴儿临床结局的影响指数

目的:探讨精索静脉显微结扎术对精索静脉曲张(VC)患者精子DNA碎片指数(DFI)及临床结局的影响。方法:选取VC伴有精子DNA碎片异常并行辅助生殖技术治疗的患者80例,按照随机数字表法分成观察组和对照组,每组40例。观察组行精索静脉显微结扎术,术后联合左卡尼汀口服溶液治疗;对照组单纯采用左卡尼汀口服溶液治疗。疗程3个月。治疗后,观察两组患者精子DNA碎片指数(DFI)、精子浓度、前向运动精子百分比(PR)及临床结局指标的变化。结果:治疗后,观察组总有效率高于对照组(P<0.05);观察组DNA碎片指数明显低于对照组(P<0.05),观察组精子浓度、PR明显高于对照组(P<0.01)。观察组受精率、卵裂率、优质胚胎率、养囊成功率及妊娠率均高于对照组(P<0.05)。结论:精索静脉曲张结扎术后联合左卡尼汀口服溶液能明显改善精索静脉曲张患者的精子质量,同时能修复患者精子DNA的完整结构,对体外受精(IVF)的临床结局有促进作用,疗效优于单纯运用左卡尼汀口服溶液治疗。

时差成像胚胎培养系统观察精子DNA碎片化指数对卵胞浆内单精子显微注射的胚胎发育及临床结局的影响

目的使用时差成像(time-lapse imagining,TLI)胚胎培养系统观察精子DNA碎片化指数(DNA fragmentation index,DFI)对卵胞浆内单精子显微注射(intracytoplasmic sperm injection,ICSI)的胚胎发育指标及临床结局的影响。方法选取2023年1月至6月在上海交通大学医学院附属国际和平妇幼保健院辅助生殖科接受ICSI技术助孕的392对夫妇为研究对象,分为常规培养组284周期和TLI组108周期,再根据DFI≤15%、>15%~<30%、≥30%进一步分为正常组、临界组、异常组。比较各组的临床资料以及临床妊娠结局。统计学方法采用t检验、单因素方差分析、χ^(2)检验或Fisher确切概率法。结果6组的女方年龄、基础促卵泡激素(follicle stimulating hormone,FSH)、身体质量指数(body mass index,BMI)及获卵数比较,差异均无统计学意义(P值均>0.05);男方精液常规指标中,浓度和正常形态率比较,差异均无统计学意义(P值均>0.05);常规正常组、常规临界组、常规异常组、TLI正常组、TLI临界组和TLI异常组的前向运动精子率分别为(46.5±16.5)%、(31.0±14.2)%、(14.8±8.4)%、(41.6±16.2)%、(32.5±14.4)%、(19.3±11.1)%,常规异常组和TLI异常组的前向运动精子率分别低于常规正常组、常规临界组、TLI正常组和TLI临界组(P值均<0.05)。6组的卵裂率和囊胚形成率比较,差异无统计学意义(P>0.05)。常规正常组、常规临界组、常规异常组、TLI正常组、TIL临界组和TLI异常组的受精率分别为(77.3±18.6)%、(78.6±17.1)%、(68.3±22.7)%、(77.4±14.5)%、(74.5±13.1)%、(63.1±25.4)%;常规异常组的受精率低于常规正常组、常规临界组、TLI正常组(P值均<0.05);TLI异常组的受精率低于常规正常组、常规临界组、TLI正常组、TLI临界组(P值均<0.05)。常规正常组、常规临界组、常规异常组的妊娠率分别为57.4%(39/68)、54.5%(24/44)、27.3%(6/22),异常组低于正常组和临界组(P值均<0.05)。TLI正常组、TLI临界组和TLI异常组3组的妊娠率比较,差异无统计学意义(P>0.05)。常规组3组之间以及TLI 3组之间的早期流产率比较,差异无统计学意义(P>0.05)。结论精子DFI值的升高会影响精子前向运动率,还会影响胚胎的受精率,高DFI精子进行ICSI助孕时使用TLI胚胎培养系统可以获得稳定的妊娠率。

Early apoptotic changes in human spermatozoa and their relationships with conventional semen parameters and sperm DNA fragmentation

Aim： To investigate whether early apoptotic changes in spermatozoa can be significant markers for sperm quality. Methods： Two early apoptotic changes in the semen of 56 men were assessed using Annexin V （AN）/propidium iodide （PI） staining for phosphatidylserine externalization and JC-1 staining for mitochondrial membrane potential （MMP）. The results were compared with conventional semen parameters and DNA fragmentation identified using the TUNEL assay. Results： The different labeling patterns in the bivariate Annexin V/PI analysis identified four distinctive spermatozoa populations. The percentage of AN^-/PI^- spermatozoa positively correlated with conventional semen parameters and MMP, but negatively correlated with TUNEL （＋） spermatozoa. As for the AN^-/PI^＋ fraction, we found an opposite result in comparison to AN^-/PI^- spermatozoa. The level of early apoptotic AN^＋/PI^- spermatozoa negatively correlated with MMP and sperm motility. The level of late apoptotic AN^＋/PI^＋ spermatozoa negatively correlated with conventional semen parameters and MMP, and positively correlated with TUNEL （＋） spermatozoa. MMP positively correlated with conventional semen parameters, but negatively correlated with TUNEL （＋） spermatozoa. Conclusion： Although early apoptotic AN^＋/PI^- spermatozoa only negatively correlates with sperm motility, the differences in proportion of each subpopulation of spermatozoa （especially, the percentage of AN^-/PI^- spermatozoa）, and decreased MMP might be significant markers for diagnosing male infertility. They possibly bring additional information to predict the outcome of in vitro fertilization. （Asian J Androl 2008 Mar; 10： 227-235）

Diagnostic value of sperm DNA fragmentation and sperm high-magnification for predicting outcome of assisted reproduction treatment

Over the last years, major improvements in the field of male infertility diagnosis have been achieved. The aim of this study was to determine the diagnostic usefulness of sperm DNA integrity and sperm vacuolisation for predicting outcome in infertile couples undergoing in vitroferti lisation （IVF） and intracytoplasmic sperm injection （ICSI） treatments. A cohort study from 152 infertile couples undergoing sperm DNA fragmentation and high-magnification tests prior to an assisted reproduction treatment was designed. We found that the most predictive cutoff for pregnancy was 25.5% of DNA fragmentation with a negative predictive value of 72.7% （P=0.02）. For the degree of vacuolisation, the best predictor of pregnancy was 73.5% of vacuolated sperm grades Ⅲ ＋ Ⅳ with a negative predictive value of 39.4% （P=0.09）, which was not statistically significant. In conclusion, sperm DNA fragmentation greater than 25.5% could be associated with higher probability of failure IVF treatment. Regarding the results of the sperm analysis at high magnification, they do not allow us to predict whether or not oatients will become pregnant.

DNA fragmentation in apoptosis

Cleavage of chromosomal DNA into oligonucleosomal size fragments is an integral part of apoptosis. Elegant biochemical work identified the DNA fragmentation factor (DFF) as a major apoptotic endonuclease for DNA fragmentation in vitro. Genetic studies in mice support the importance of DFF in DNA fragmentation and possibly in apoptosis in vivo. Recent work also suggests the existence of additional endonucleases for DNA degradation. Understanding the roles of individual endonucleases in apoptosis, and how they might coordinate to degrade DNA in different tissues during normal development and homeostasis, as well as in various diseased states, will be a major research focus in the near future.

Can DNA fragmentation of neat or swim-up spermatozoa be used to predict pregnancy following ICSI of fertile oocyte donors？

This study compared the potential of assessing sperm DNA fragmentation （SDF） from neat semen and the subsequent swim-up （SU） procedure to predict pregnancy when conducting ICSI of fertile donor oocytes. Infertile females （n=81） were transferred embryos resulting from intracytoplasmic sperm injection （ICSI） of their partner＇s spermatozoa and proven donor oocytes. This model normalized the impact of female factor in putative sperm DNA repair. Semen was blindly assessed for SDF using Halosperm immediately following ejaculation （NS） and after swim-up at the time of ICSI fertilisation. There was a decrease in SDF values of the ejaculated semen sample following the swim-up protocol （P=0.000）. Interestingly, pregnancy could be equally predicted from SDF values derived from either neat or swim-up semen samples. Receiver operator curves and the derived Youden＇s indices determined SDF cutoff values for NS and SU of 24.8% and 17.5%, respectively. Prediction of pregnancy from NS SDF had a sensitivity of 75% and a specificity of 69%, whereas for SU SDF was 78% and 73%, respectively. While increased levels of SDF negatively impact reproductive outcome, we have shown that a reduction in SDF following sperm selection using ICSI with proven donor oocytes is not mandatory for achieving pregnancy. This suggests that a certain level of DNA damage that is not detectable using current technologies could be impacting on the relative success of assisted reproductive technology （ART） procedures. Consequently, we propose a modification of the so called ＇iceberg model＇ as a possible rationale for understanding the role of SDF in reproductive outcome.

Lethal effect and apoptotic DNA fragmentation in response of D-GalN-treated mice to bacterial LPS can be suppressed by pre-exposure to minute amount of bacterial LPS: Dual role of TNF receptor 1

AIM: To investigate whether induction of tolerance of mice to lipopolysaccharide (LPS) was able to inhibit apoptotic reaction in terms of characteristic DNA fragmentation and protect mice from lethal effect. METHODS: Experimental groups of mice were pretreated with non-lethal amount of LPS (0.05 μg). Both control and experimental groups simultaneously were challenged with LPS plus D-GaIN for 6-7 h. The evaluations of both DNA fragmentations from the livers and the protection efficacy against lethality to mice through induction of tolerance to LPS were conducted. RESULTS: In the naive mice challenge with LPS plus D-GaIN resulted in complete death in 24 h, whereas a characteristic apoptotic DNA fragmentation was exclusively seen in the livers of mice receiving LPS in combination with D-GaIN. The mortality in the affected mice was closely correlated to the onset of DNA fragmentation. By contrast, in the mice pre-exposed to LPS, both lethal effect and apoptotic DNA fragmentation were suppressed when challenged with LPS/D-GalN. In addition to LPS, the induction of mouse tolerance to TNF also enabled mice to cross-react against death and apoptotic DNA fragmentation when challenged with TNF and/or LPS in the presence of D-GaIN. Moreover, this protection effect by LPS could last up to 24 h. TNFR1 rather than TNFR2 played a dual role in signaling pathway of either induction of tolerance to LPS for the protection of mice from mortality or inducing morbidity leading to the death of mice. CONCLUSION: The mortality of D-GalN-treated mice in response to LPS was exceedingly correlated to the onset of apoptosis in the liver, which can be effectively suppressed by brief exposure of mice to a minute amount of LPS. The induced tolerance status was mediated not only by LPS but also by TNF. The developed tolerance to either LPS or TNF can be reciprocally cross-reacted between LPS and TNF challenges, whereas the signaling of induction of tolerance and promotion of apoptosis was through TNFR1, rather than TNFR2.

Genetic alterations of hepatocellular carcinoma by random amplified polymorphic DNA analysis and cloning sequencing of tumor differential DNA fragment

AIM: To study the genetic alterations and their association with clinicopathological characteristics of hepatocellular carcinoma (HCC), and to find the tumor related DNA fragments.METHODS: DNA isolated from tumors and corresponding noncancerous liver tissues of 56 HCC patients was amplified by random amplified polymorphic DNA (RAPD)with 10 random 10-mer arbitrary primers. The RAPD bands showing obvious differences in tumor tissue DNA corresponding to that of normal tissue were separated,purified, cloned and sequenced. DNA sequences were analyzed and compared with GenBank data.RESULTS: A total of 56 cases of HCC were demonstrated to have genetic alterations, which were detected by at least one primer. The detestability of genetic alterations ranged from 20% to 70% in each case, and 17.9% to 50% in each primer. Serum HBV infection, tumor size,histological grade, tumor capsule, as well as tumor intrahepatic metastasis, might be correlated with genetic alterations on certain primers. A band with a higher intensity of 480 bp or so amplified fragments in tumor DNA relative to normal DNA could be seen in 27 of 56 tumor samples using primer 4. Sequence analysis of these fragments showed 91% homology with Homo sapiens double homeobox protein DUX10 gene.CONCLUSION: Genetic alterations are a frequent event in HCC, and tumor related DNA fragments have been found in this study, which may be associated with hepatocarcinogenesis. RAPD is an effective method for the identification and analysis of genetic alterations in HCC, and may provide new information for further evaluating the molecular mechanism of hepatocarcinogenesis.

LDFF,the large molecular weight DNA fragmentation factor,is responsible for the large molecular weight DNA degradation during apoptosis in Xenopus egg extracts

DNA degradation is a biochemical hallmark in apoptosis. It has been demonstrated in many cell types that there are two stages of DNA fragmentation during the apoptotic execution. In the early stage, chromatin DNA is cut into large molecular weight DNA fragments, although the responsible nuclease(s) has not been recognized. In the late stage, the chromatin DNA is cleaved further into short oligonucleosomal fragments by a well-characterized nuclease in apoptosis,the caspase-activated DNase (CAD/DFF40). In this study, we demonstrate that large molecular weight DNA fragmentation also occurs in Xenopus egg extracts in apoptosis. We show that the large molecular weight DNA fragmentation factor (LDFF) is not the Xenopus CAD homolog XCAD. LDFF is activated by caspase-3. The large molecular weight DNA fragmentation activity of LDFF is Mg2+-dependent and Ca2+-independent, can occur in both acidic and neutral pH conditions and can tolerate 45℃ treatment. These results indicate that LDFF in Xenopus egg extracts might be a new DNase (or DNases) responsible for the large DNA fragmentation.

Frequency of Monthly Ejaculation at Sexual Intercourse, DNA Fragmentation Index and Fertilization Rate among Sperm Donors and Fertility-Challenged Men in Sub-Saharan Africa: Paper 1

Introduction: In humans, the ideal ejaculation frequency depends on age, exercise and sexual potential. Natural ejaculation frequency balances the testosterone levels in the body. Materials and Methods: Semi-structured questionnaire was used to collect information from subjects. Semen samples were collected from sperm donors and sub-fertile men who presented for infertility challenges. Processing and analysis of semen samples were done according to World Health Organization guidelines. Sperm DNA fragmentation was evaluated using the Halosperm&#174;?kit. Results: A total of 114 subjects, including 19 sperm donors and 95 sub-fertile males were studied. There was a significant difference (t =?&#8722;5.96, P-value = 0.00001) in the mean [±sd] age of sperm donors (30.8 [8.1]) and that of sub-fertile men (42.3 [76]). There was a significant difference (t=?&#8722;4.10, P-value = 0.0005) in the mean monthly ejaculation during sexual intercourse (MESI) among sperm donors with DNA fragmentation index &#8722;2.20, P-value = 0.02) in MESI among sub-fertile men aged ≥40 years (8.9 [4.6]) than among those aged &#8722;0.67, SE = 0.28, t = &#8722;2.40, P-value = 0.02, 95% CI: &#8722;1.24,?&#8722;0.10). Conclusion: In men < 40 years, fewer MESI did not worsen the DFI. A higher number of professionals such as doctors, lawyers and engineers, reported lower monthly frequency of sexual ejaculations compared to entrepreneurs. Entrepreneurs and non-smokers had the highest frequencies of MESI.

Sperm DNA fragmentation does not affect the clinical outcomes in the cumulative transfers of an ICSI cycle along with blastocyst transfers in couples with normozoospermic male patients

Objective:To know whether sperm DNA fragmentation(SDF)affects the clinical outcomes in the cumulative transfers of an intracytoplasmic sperm injection(ICSI)cycle along with blastocyst transfers in couples with normozoospermic males.Methods:The study included 252 couples who underwent their first ICSI cycles along with blastocyst transfer and whose male partner semen samples were normozoospermic according to the World Health Organization 2010 criteria.All the couples were classified into two groups based on the SDF:the low SDF group(SDF≤30%,n=162)and the high SDF group(SDF>30%,n=90).Clinical as well as laboratory outcomes were correlated between the two groups.Sperm DNA fragmentation was assessed on the post-wash semen samples by acridine orange test.The main outcome measures were the live birth rate and miscarriage rate.Results:A significant decrease in the live birth rates was observed in the high SDF group compared to the low SDF group in fresh embryo transfer cycles(P<0.05).However,no significant difference was observed in the clinical outcomes either in the frozen embryo transfer cycles or in the overall cumulative transfer cycles(P>0.05).No significant difference was observed in the laboratory outcomes between the two SDF groups.A remarkable decrease in sperm motility was observed in the high SDF group compared to the low SDF group(P<0.05).Conclusions:Sperm DNA fragmentation does not affect the clinical outcomes in the cumulative transfers of an ICSI cycle along with blastocyst transfers in couples with normozoospermic males.