病毒感染与男性不育关系的研究进展

近年来研究发现病毒感染与不孕不育存在一定的联系,人类免疫缺陷病毒、乙肝病毒等感染不仅损伤生殖系统的功能、影响生育能力,而且也能够通过性接触传播而导致不育,病毒的遗传物质可通过干扰精卵正常受精或影响胚胎的正常着床导致不孕。在男性不育方面,病毒主要通过损伤睾丸功能和影响精子浓度、活力、形态以及DNA完整性使精子质量降低,影响正常精卵结合,进而导致男性生育能力下降甚至不育。本文就相关病毒感染与男性不育的关系做一综述。     

移动电话电离辐射体外诱导人精子产生活性氧物质损伤精子DNA

近年来有很多关于电离辐射影响人类健康的争论。自从有研究认为使用移动电话产生的电离辐射与精液质量存在相关性后，移动电话电离辐射对人类生殖功能的影响便成了主要的争论点之一。其作用机理至今不清楚，然而人类精子容易被氧化应激产生的氧自由基攻击和自身缺乏抗氧化物酶而受到损伤，氧化应激诱导不仅影响精子受精能力，而且还使精子DNA损伤，导致低生育能力、增加流产率以及后代的疾病发生率包括小儿肿瘤等。     

精子形态学与动力学参数间的相关性研究

正近年来由于环境污染加剧、社会压力增大、生活节奏增快等原因,男性的生育能力日趋下降[1,2]。对男性不孕不育的诊断已经不能仅仅依靠常规的精子动力学检查来完成了,精子形态学的分析被越来越受到重视。有研究[3,4]表明精子的正常形态率与男性的生育能力存在一定的相关性。精子形态学参数与精子动力学参数是否存在着相关性、精子形态学的异常是     

精子DNA损伤在男性不育症中的研究进展

男性不育症是现今困扰我国不孕不育夫妇的一个严重问题。目前临床上对于男性不育的筛查主要取决于精液常规的检查。但由于精液本身的易干扰性,导致其已不能对精子的受精能力及男性的生育能力进行准确的评价。近年来,精子DNA损伤作为一项新的评价精子功能的指标,逐渐成为男性不育症的研究热点。本文就精子DNA损伤的原因、机制及在男性不育症中的研究进展作一综述,为男性不育症的诊断和治疗研究提供依据。     

锌硒宝对少弱精子症的疗效观察

精液中活动精子的比例及数量对男子的生育力起决定性的作用。精子的质量与人体必需的锌、镁、硒、镉等多种微量元素密切相关。近年来，随着生活方式的改变和环境的日益恶化，男性精子质量逐渐下降，由男性精液质量异常导致的不育症发病率逐渐升高，而作为促进精子发生、成熟、维持精子正常功能的微量元素特别是锌和硒在男性生育能力中发挥着重要的作用。本研究通过对138例患有少弱精子症的患者服用锌硒宝片剂疗效的观察，讨论锌硒宝在治疗男性少弱精子症导致的不育方面的作用。     

人类精子冷冻保存技术的研究进展

精子冷冻保存技术是保留男性生育能力的重要方式,在人类辅助生殖领域应用广泛。然而长时间的冷冻会损伤精子的结构和功能,因此寻找合适的冷冻保存技术是目前的研究重点之一。本文就近年来国内外精子冷冻保护剂和冷冻保存方式的研究新进展进行综述。     

4种精液处理方法精子形态学分析的比较

正有研究表明,近十五年来中国男性的精液质量下降,唤起了社会对男性生殖健康的重视[1]。故临床需借助一些精子功能检查实验以评估男性生育能力,其中精子形态染色分析就是近年来才得以重视的用于评价精子质量的实验之一[2]。并且,近年来随着生殖医学及人类辅助生殖技术的发展,精子形态学分析已经成为临床例行检查的一部分,在评价生育力及预测体外受精的成功率方面有着重要意义[3]。尽管精子形态学分析至关重要,但有关于精     

精子形态学检查的研究进展

据报道,世界范围内约有15％～20％的育龄夫妇不能生育,且近半个世纪以来,随着全球污染问题的日益严重,社会竞争压力的日趋增加,生活步伐节奏的不断加快,男性生殖健康正受到严重威胁,男性精子数量几乎减少了一半,并且,还以每年2.1％的速度在减少.同时,畸形、劣质精子比例逐渐增多,精子活力、穿透力、致孕率在不断下降,致使男性不育的比例正在逐年上升.精液分析在诊断男性不育及辅助生殖方面起到越来越重要的作用,精液分析主要包括了精子形态、精子活力和精子密度等.随着染色技术的发展和畸形精子分类体系的形成,精子形态学检查对不孕不育症诊断、生育能力预测以及基础或者公共健康研究有重要意义,比精子密度、精液质量和运动性更能在受孕中起到预测作用[1].本文主要从精子形态学检查的发展历史、方法学比较、分类标准和临床意义等方面进行综述.     

辅酶Q_(10)的生物学功能及其对精子质量的影响

过氧化损伤是导致精子质量下降的重要原因之一,辅酶Q10是一种存在于线粒体中的脂溶性抗氧化剂,其在精浆和精子中的水平对男性生殖系统的抗氧化损伤能力具有重要影响。外源性补充辅酶Q10有利于改善精子质量,提高不育患者生育能力,对男性不育具有一定的辅助治疗作用。现就辅酶Q10的生物学功能及其对精子质量的影响,以及对男性不育的辅助治疗作用等方面作一综述。     

抗精子抗体对生育力影响的研究进展

从70年代起有众多的研究表明,抗精子抗体(AsAb)对人类生育能力有较大影响,但其影响程度与不育的直接关系随着近年来辅助生育技术的临床应用在不同的生育环节逐渐暴露出来。由于抗精子抗体的免疫抗原众多、成分复杂、检测方法多样,因     

精子缺陷和受精失败

不育症是当今一个重要的健康问题,有大约15％的夫妇都在为生育寻求临床治疗。在所有不能自然受孕的夫妇中,多达三分之二的夫妇是由男性生育力的下降导致的。尽管我们在生物学和生理学上对于受精的认识已有很大进步,但仍然不能解释受精失败的潜在原因。即使是在不育的男性中发现有精索静脉曲张、生殖器感染或抗精子抗体,这些因素对于不育症病因的解释价值尚不明确。     

Urogenital infection and sperm motility

Male accessory sex gland infections are considered as potential hazards to male fertility. Various pathophysiological concepts have evolved from experimental and clinical studies that begin to explain the effects of bacteria and immunological events on the function of spermatozoa and sperm motility in particular. Besides direct influences of pathogenic bacteria on spermatozoa whose impact on the motility of human spermatozoa is reviewed herein, recent studies have identified and evaluated infectious mediators that appear to be responsible for specific molecular processes in infections that particularly affect the motility of spermatozoa. This review will focus in detail on direct bacterial effects of sperm motility, the role of seminal leucocytes and the impact of pro-inflammatory cytokines on the motility of spermatozoa.     

Apoptosis and kinematics of ejaculated spermatozoa in patients with varicocele

Increased DNA fragmentation is found in sperm from infertile men. Varicocele is an important cause of male infertility, even though it is present in 15% of men who father children. Semen analysis does not always identify infertility in these patients. Sperm motility is strongly correlated with male fertility potential. The goal of this study was to determine the correlation between apoptosis and kinematics in the ejaculated spermatozoa of patients affected by varicocele. Fresh semen samples were obtained from 30 patients with varicocele and 15 fertile controls. These samples were compared using computer-assisted semen analysis and were assayed to determine the degree of sperm apoptosis. The apoptotic index (AI) was calculated by dividing the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine-5'-triphosphate nick end labeling (TUNEL) stained spermatozoa by the total number of Hoechst 33258-stained sperm cells for 300 sperm. Five microscopic fields were analyzed to obtain 5 AIs for each individual. Results demonstrated no significant difference in semen quality and sperm motion characteristics; however, a significantly higher AI (23.05% +/- 4.07%: mean difference +/- SE, 95% CI, 15.06%-31.03%, P <.0001) was identified in the varicocele group than in the fertile controls. We concluded that sperm apoptosis does not seem to correlate with semen quality and sperm kinematics and that apoptosis is increased in ejaculated spermatozoa in patients with varicocele compared to normal fertile men.     

Nicotinic infertility: assessing DNA and plasma membrane integrity of human spermatozoa

Infertility remains a major problem in society, with recent data suggesting its presence in one of four couples. The objective of the present study was to evaluate the impact of nicotine (0.25, 0.5 and 0.75 mm), as a major component of cigarette smoke, in vitro, on sperm membrane [by spermatocrit and lipoperoxidation (LPO) tests], DNA integrity (by Comet assay), and viability of spermatozoa (by eosin staining) from normozoospermic men. Sperm samples were washed and diluted with phosphate-buffered saline. A drop in spermatocrit values and an increase in thiobarbituric acid-reactive substances/LPO rate was observed with the addition of nicotine, predominantly at a concentration of 0.75 mm, indicating a deleterious effect of nicotine on sperm membrane intactness. There was also a strong negative correlation between LPO rate and percentage viable sperm cell (r = -0.990). Data obtained from Comet assay technique revealed that nicotine could induce double-stranded DNA breaks (11% in 0.75 mm concentration) in the sperm nuclei. The value of r between LPO rate and percentage Comets was found to be +0.976. Taken together, nicotine proved to be a potential oxidant agent in the category of environmental factors to the integrity of sperm plasma membrane and DNA.     

Causes and consequences of sperm mitochondrial dysfunction

Mitochondria have multiple functions, including synthesis of adenine triphosphate, production of reactive oxygen species, calcium signalling, thermogenesis and apoptosis. Mitochondria have a significant contribution in regulating the various physiological aspects of reproductive function, from spermatogenesis up to fertilisation. Mitochondrial functionality and intact mitochondrial membrane potential are a pre-requisite for sperm motility, hyperactivation, capacitation, acrosin activity, acrosome reaction and DNA integrity. Optimal mitochondrial activity is therefore crucial for human sperm function and semen quality. However, the precise role of mitochondria in spermatozoa remains to be fully explored. Defects in sperm mitochondrial function severely impair the maintenance of energy production required for sperm motility and may be an underlying cause of asthenozoospermia. Sperm mtDNA is susceptible to oxidative damage and mutations that could compromise sperm function leading to infertility. Males with abnormal semen parameters have increased mtDNA copy number and reduced mtDNA integrity. This review discusses the role of mitochondria in sperm function, along with the causes and impact of its dysfunction on male fertility. Greater understanding of sperm mitochondrial function and its correlation with sperm quality could provide further insights into their contribution in the assessment of the infertile male.     

Assessing human sperm morphology： top models,underdogs or biometrics？

The assessment of the percentage of spermatozoa having an ＇ideal＇ morphology using so-called strict method is the method recommended in the latest edition of the World Health Organization （WHO） laboratory manual for semen analysis. This recommendation is a result of the statistical association between ＇ideal＇ sperm morphology and fertility, and of the current general belief that sperm morphology assessment should be used primarily as a fertility tool. The notion of an ＇ideal＇ sperm morphology has persisted despite the very low percentage of such spermatozoa in the semen of fertile men, a subject of intense controversy. The detailed categorization of each abnormal spermatozoon has thus, for a long time, been considered optional and partially redundant, an idea which is reflected in the earlier editions of the WHO manual. However, several recent studies have shown the importance of carefully assessing abnormal sperm morphology for use in the diagnosis ＆infertility, to determine fertility prognosis, and for basic or public health studies. One approach, which combines videomicroscopy and computer vision, and is the only approach able to assess the continuum of sperm biometrics, has been used successfully in several recent clinical, basic and toxicology studies. In summary, the visual assessment of detailed sperm morphology--including the categorization of anomalies allowing arithmetically derived indices of teratozoospermia--and the more modern computer-based approaches, although often considered to be redundant, are in fact complementary. The choice of the most appropriate method depends on the field of investigation （clinical, research, toxicology） and the problem being addressed. Each approach has advantages as well as certain limitations, which will be discussed briefly herein.     

Clinical relevance of oxidative stress and sperm chromatin damage in male infertility: an evidence based analysis

Oxidative stress (OS) in the reproductive tract is now a real entity and concern due to the potential harmful effects of high levels of reactive oxygen species (ROS) on sperm number, motility, quality, and function including damage to sperm nuclear DNA. Evaluation of OS related damage to non-functional sperm is highly relevant as intracytoplasmic sperm injection (ICSI) technique, an effective therapy for severe male factor infertility, bypasses the majority of reproductive tract deficiencies. Despite the controversial findings in the existing literature, there is now enough evidence to show that sperm DNA damage is detrimental to reproductive outcomes. In addition, spermatozoa of infertile men are suggested to carry more DNA damage than do the spermatozoa from fertile men. Besides impairment of fertility such damage is likely to increase the transmission of genetic diseases during the assisted reproductive procedures. Standardization of protocols to assess reactive oxygen species and DNA damage is very important in introducing these tests in such clinical practice. Thus evaluation of seminal ROS levels and extent of sperm DNA damage especially in an infertile male may help develop new therapeutic strategies and improve success of assisted reproductive techniques (ART).     

Onco‐testicular sperm extraction: testicular sperm extraction in azoospermic and very severely oligozoospermic cancer patients

An increased risk of testicular cancer in men with infertility and poor semen quality has been reported. In view of the high cure rates for testicular germ cell tumours, increasing clinical importance is being placed on the protection of fertility. High‐dose cytostatic therapy may be expected to cause long‐term infertility. Thus, the standard procedure for fertility protection is the cryopreservation of ejaculated spermatozoa or testicular tissue before therapy. Four male patients with azoospermia and two patients with very severe oligozoospermia underwent onco‐testicular sperm extraction (TESE). We attempted onco‐TESE in patients with azoospermia and very severe oligozoospermia after orchiectomy. Of the patients with testicular germ cell tumours, four had spermatozoa in their testicular tissues. Sertoli cell‐only syndrome was found in one patient, and one patient showed maturation arrest without the detection of spermatozoa. Three of six showed seminomatous germ cell tumour, two of six had nonseminomatous germ cell tumour and one patient showed no malignancy. Two patients achieved clinical pregnancy. Fertility challenges in men with cancer are the most straightforward because of the relative ease of obtaining and cryopreserving sperm. Testicular sperm extraction is a useful technique for obtaining spermatozoa before cytotoxic therapy in azoospermic and very severely oligozoospermic cancer patients.