环境内分泌干扰物对男性生殖的影响

环境内分泌干扰物是一种可以干扰激素行为的外源性化学物,广泛存在于日常生活中。它可以结合人体内不同的受体,通过多种机制增强或抑制机体内正常的内分泌功能,进而引起多种疾病的发生。本文就内分泌干扰物对男性生殖的影响,分别从内分泌干扰物与男性生殖疾病的关系及相关作用机制等方面进行论述,总结了内分泌干扰物与男性生殖的关系。     

环境内分泌干扰物引致儿童性早熟的临床分析

目的研究环境内分泌干扰物对儿童性早熟的影响。方法回顾性分析笔者所在医院收治的108例性早熟患儿的病历资料,对其作出总结和探讨。结果其中21例为真性性早熟,54例为假性性早熟,33例为部分性性早熟,多数发病病因和环境内分泌干扰物有不同程度的关联。结论环境内分泌干扰物与儿童性早熟确实存在密切的关系,需引起重视。     

尿道下裂大鼠模型的建立及莠去津对大鼠尿道下裂发病率的影响

目的建立SD大鼠尿道下裂动物模型,探讨莠去津对大鼠尿道下裂的发病率有无影响。方法将受孕的SD大鼠120只,随机分为6组,每组20只。于孕期第11～16天时,每天分别给予莠去津25mg/kg、莠去津100mg/kg、莠去津200mg/kg、植物油1ml/kg、非那雄胺10mg/kg、非那雄胺20mg/kg。给药后即刻观察并记录动物的反应情况,于孕期第0、3、6、9、12、15、18、20天称重以调整剂量。于仔鼠出生后第21天,检测其有无尿道下裂,并记录其肛生殖窦距离及其体重。结果200mg/kg莠去津组、10mg/kg非那雄胺组、20mg/kg非那雄胺组仔鼠出生时尿道下裂发生率分别为10.23%、28.30%、67.03%;25mg/kg莠去津组中有2只母鼠的胚胎着床后发育停滞。各组雄性仔鼠的肛生殖窦距离（AGD）与其体重存在正相关关系。结论①大鼠仔鼠尿道下裂表现为阴茎头和（或）阴茎腹侧裂开、尿道口异位,并有肛生殖窦距离的变窄,SD大鼠孕期第11～16天管饲每天10mg/kg及20mg/kg非那雄胺,可以建立尿道下裂动物模型。②莠去津对SD大鼠是一种胚胎致畸物。     

环境内分泌干扰物对男性生殖健康影响的研究进展

近年来,环境内分泌干扰物(EDCs)对人类的生物学效应日益引起关注,大量实验及流行病学资料表明EDCs具有生殖和发育毒性,能导致男性精子质量下降、生殖系统发育异常及肿瘤,其作用机制非常复杂。深入研究EDCs与男性生殖健康的关系,是关系到人类繁衍的重大问题。     

内分泌干扰物对精液质量的影响

内分泌干扰化合物(endocrine disrupting chemicals,EDCs)是指外源性的能干扰人类或动物内分泌系统诸环节并导致异常效应,或使其后代内分泌功能发生改变的化学物质。EDCs种类繁多,广泛存在于土壤、水、甚至食物中。本文从农药、塑料增塑剂和洗涤剂这3类常见EDCs着手,从流行病学和生物学角度阐述了其对人类及动物精液质量的影响。     

尿道下裂相关影响因素分析

尿道下裂是男性小儿泌尿生殖系统最常见的先天性畸形之一,其病因复杂,发病率呈逐年上升趋势.目前其病因学研究提示尿道下裂的发生是复杂的遗传因素、环境因素、内分泌因素及其他因素综合作用的结果.     

减少Duckett手术治疗尿道下裂并发症发生的体会

目的 探讨提高Duckett术式治疗尿道下裂手术成功率的技术要点.方法 2000至2008年采用Duckett手术1期治疗尿道下裂共57例病例.分A组(2000年至2005年手术的)和B组(2006年至2008年手术的)进行手术成功率、尿瘘及尿道狭窄发生率的分析比较.结果 B组手术成功率高于A组,尿瘘和尿道狭窄等并发症发生率更低(P<0.05).结论 Duckett手术要注意带血管蒂皮瓣的分离层面以及尿道管的缝合技术.血管蒂筋膜覆盖尿道管可以减少尿瘘发生.术中要注意消灭创面死腔.尿道吻合口和尿道外口缝合要宽敞.熟练掌握并灵活运用Duckett术式可以减少尿道F裂并发症的发生.     

邻苯二甲酸二丁酯诱导雄性大鼠发生尿道下裂的分子作用机制

目的探讨邻苯二甲酸二丁酯（DBP）孕晚期染毒诱导雄性大鼠发生尿道下裂的分子作用机制。方法雌鼠怀孕（GD）第14—18天，每天分别灌胃予大豆油，DBP500或每日800mg／kg体重，雄性仔鼠出生后（PND）第1天，鉴别出DBP染毒组中发生尿道下裂的雄性仔鼠，分组为雄性仔鼠对照组（A组），每日500mg／kg体重（H）（B组）和每日800mg／kg体重（H）（C组）。用实时定量逆转录-聚合酶链反应（RT-PCR）方法检测阴茎组织中Shh，骨形态发生蛋白4（Bmp4）和雄激素受体（Ar）mRNA表达水平。用Westernblot测量阴茎组织中Ar蛋白表达水平。用放射免疫分析法测定血清睾酮（T）水平。结果B组在mRNA（Shh，Ar）表达水平和血清睾酮水平较对照组有明显的降低（P〈0．05），C组在mRNA（Shh，Bmp4，Ar）和蛋白（Ar）表达水平以及血清睾酮水平都较对照组有明显的降低（P〈0．05）。结论DBP通过对生殖结节（GT）生长发育早期的Shh信号系统，以及晚期的雄激素信号系统发生作用而影响GT的生长发育，诱导尿道下裂的发生。     

尿道下裂修复中非手术技术因素对疗效的影响

目的:探讨尿道下裂手术修复中的非手术技术因素对手术效果的影响。方法:将1999年1月~2006年1月收治的285例尿道下裂患者,以2003年1月为界限分为两组,比较两组的手术效果,分析非手术技术与疗效的关系。结果:2003前组治疗尿道下裂165例,平均住院时间18d;出现尿瘘17例,并发尿道外口狭窄6例、吻合口狭窄3例、尿道长段狭窄1例,尿囊形成5例。总手术成功率为81%。2003后组共治疗尿道下裂120例,平均住院时间12d;术后近期出现尿瘘5例,其中3例在术后3个月内自行愈合;并发尿道外口狭窄并尿囊形成1例,尿道外口狭窄2例、吻合口狭窄1例。总手术成功率为95%。结论:术中优化非手术技术因素(如:废除膀胱造瘘,容易更换敷料,不用拆线等)能减轻患者痛苦,提高手术成功率。     

尿道下裂的手术治疗

目的:探讨多种手术方式在治疗尿道下裂中的价值。方法:通过对150例尿道下裂的手术治疗的成功率、并发症等进行分析。结果:本组应用分期手术即Ⅰ期阴茎伸直术,Ⅱ期Denis Browne尿道成形术,成功率64.6％。应用Ⅰ期手术成功率达到67.4％。结论:治疗尿道下裂应首选Ⅰ期手术,其中无阴茎下弯的尿道下裂应选用MAGPⅠ、Mathieu及onlay islandflap术式,有阴茎下弯的尿下裂应首选Duckett术式。     

Endocrine disruptors, genital development, and hypospadias

Hypospadias is one of the most common congenital anomalies in the United States, occurring in approximately 1 in 125 live male births. Embryological studies have demonstrated that, depending on where the urethral development arrests, the meatal opening can be anywhere along the shaft of the penis or, in more severe forms, within the scrotum or in the perineum. Currently, the only available treatment is surgery. If left uncorrected, especially in its severe form, there is risk of infertility and psychological effects, such as avoidance of intimate relationships. The cause of hypospadias is largely unknown; however, current epidemiology and laboratory studies have shed new light into the etiology of hypospadias. With recent advancements in molecular biology and microarray technology, it appears that hypospadias is potentially related to disrupted gene expression. Specifically, some of the environmental chemicals are acting as antiandrogens and interfere directly with the action of testosterone-related gene expression. In this paper, we briefly review the normal development of male external genitalia and the prevalence and environmental risk factors related to hypospadias. In addition, we discuss some of the recent laboratory findings that contribute to our current understanding of this disease.     

The role of excretory urography in patients with hypospadias

The routine use of excretory urography in asymptomatic patients with hypospadias is still a subject of controversy. In 169 patients with hypospadias we reviewed the indications for urographic evaluation and the radiographic results. Of the boys 67 had signs or symptoms of urological disorders, and 102 were asymptomatic and screened prospectively. Abnormalities in those patients with symptoms were significant, which supports the need to continue evaluating patients in this group radiographically. In those boys screened prospectively the incidence of upper tract abnormalities was low. Reflux was discovered in 10 per cent of these patients, although in the majority it was mild and of no surgical consequence. Over-all, reflux remains the single most common urographic abnormality in boys with hypospadias with or without symptoms.     

The role of pre-operative androgen stimulation in hypospadias surgery

The hormonal stimulation for the purpose of penile enlargement before the hypospadias repair has been commonly used, but rarely reported. In addition to functional outcome, dihydrotestosterone (DHT) pretreatment has been suggested to improve cosmetic outcome in a preliminary randomized study. Since the randomized and controlled clinical trials on this topic are insufficient, the hormonal agent, the route of administration, dosing schedule, and the timing of treatment has been remained controversial. In order to confirm the efficiency of hormonal treatment, further well designed randomized studies with a larger number of patients and a placebo group are warranted.     

The contemporary role of 1 vs. 2-stage repair for proximal hypospadias

This review discusses the most commonly employed techniques in the repair of proximal hypospadias, highlighting the advantages and disadvantages of single versus staged surgical techniques. Hypospadias can have a spectrum of severity with a urethral meatus ranging from the perineum to the glans. Associated abnormalities are commonly found with proximal hypospadias and encompass a large spectrum, including ventral curvature (VC) up to 50 degrees or more, ventral skin deficiency, a flattened glans, penile torsion and penoscrotal transposition. Our contemporary understanding of hypospadiology is comprised of a foundation built by experts who have described a number of techniques and their outcomes, combined with survey data detailing practice patterns. The two largest components of hypospadias repair include repair of VC and urethroplasty. VC greater than 20 degrees is considered clinically relevant to warrant surgical correction. To repair VC, the penis is first degloved—a procedure that may reduce or remove curvature by itself in some cases. Residual curvature is then repaired with dorsal plication techniques, transection of the urethral plate, and/or ventral lengthening techniques. Urethroplasty takes the form of 1- or 2-stage repairs. One-stage options include the tubularized incised urethroplasty (TIP) or various graft or flap-based techniques. Two-stage options also include grafts or flaps, including oral mucosal and preputial skin grafting. One stage repairs are an attractive option in that they may reduce cost, hospital stay, anesthetic risks, and time to the final result. The downside is that these repairs require mastery of multiple techniques may be more complex, and—depending on technique—have higher complication rates. Two-stage repairs are preferred by the majority of surveyed hypospadiologists. The 2-stage repair is versatile and has satisfactory outcomes, but necessitates a second procedure. Given the lack of clear high-quality evidence supporting the superiority of one approach over the others, hypospadiologists should develop their own algorithm, which gives them the best outcomes.     

Neoplasia as development gone awry: the role of endocrine disruptors

The hypothesis that prenatal exposure to endocrine disruptors might cause cancer arose from challenging two well-accepted notions: (i) mammalian development is merely the unfolding of a genetic programme and (ii) only mutagenic agents can cause cancer. This hypothesis required challenging genetic determinism. The ecological developmental biology (eco-devo) movement revitalized the concept of developmental plasticity through the occurrence of polyphenisms (a single genotype produces diverse phenotypes which are determined by environmental cues). Based on the principles of eco-devo and the tissue organization field theory of carcinogenesis and neoplasia, we tested the hypothesis that exposure to xenoestrogens during foetal development in rats increased the propensity to develop mammary cancer during adulthood. We chose exposure to bisphenol A (BPA) as a model for environmental oestrogen exposure. This endocrine disruptor induced the development of ductal hyperplasias and carcinoma in situ. These highly proliferative lesions contained an increased number of oestrogen receptor alpha-positive cells. Thus, foetal BPA exposure was sufficient to induce the development of oestrogen-sensitive pre-neoplastic and neoplastic lesions in the mammary gland in the absence of any additional treatment aimed at increasing tumour incidence.