Applications of emerging technologies to the study and conservation of threatened and endangered species

Sustaining viable populations of all wildlife species requires the maintenance of habitat, as well as an understanding of the behaviour and physiology of individual species. Despite substantial efforts, there are thousands of species threatened by extinction, often because of complex factors related to politics, social and environmental conditions and economic needs. When species become critically endangered, ex situ recovery programmes that include reproductive scientists are the usual first line of defence. Despite the potential of reproductive technologies for rapidly increasing numbers in such small populations, there are few examples of success. This is not the result of a failure on the part of the technologies per se, but rather is due to a lack of knowledge about the fundamental biology of the species in question, information essential for allowing reproductive technologies to be effective in the production of offspring. In addition, modern conservation concepts correctly emphasise the importance of maintaining heterozygosity to sustain genetic vigour, thereby limiting the practical usefulness of some procedures (such as nuclear transfer). However, because of the goal of maintaining all extant gene diversity and because, inevitably, many species are (or will become) 'critically endangered', it is necessary to explore every avenue for a potential contributory role. There are many 'emerging technologies' emanating from the study of livestock and laboratory animals. We predict that a subset of these may have application to the rescue of valuable genes from individual endangered species and eventually to the genetic management of entire populations or species. The present paper reviews the potential candidate techniques and their potential value (and limitations) to the study and conservation of rare wildlife species.     

Which reproductive technologies are most relevant to studying, managing and conserving wildlife?

The advent of in vitro fertilisation (IVF) and embryo transfer in the 1970s led to speculation about the potential value of these and other 'reproductive technologies' to conserving endangered species. So far, and for the most part, assisted breeding techniques that are routine in domesticated species are not easily adapted to wildlife. Species differences in reproductive form (anatomy/morphology) and function (mechanisms regulating reproductive success) limit the practical applicability for offspring production. Thus, the limiting factor is the lack of basic knowledge about thousands of unstudied species, the foundation that is essential to allowing reproduction to be enhanced and/or controlled. There now is excellent evidence that reproductive technologies are most useful as tools for studying how different species reproduce, especially defining novel and unique mechanisms. The present paper reviews the status and relevance of various reproductive technologies that are useful or have potential for wildlife. Modern examples of progress are provided indicating how these tools are being used to understand ways that wildlife species reproduce and, in some cases, how such knowledge has been used for successful assisted breeding, improved management and conservation.     

人类辅助生殖技术研究进展

自从世界上第1例"试管婴儿"诞生以来,人类辅助生殖技术已经走过了30年的发展历程。随着人们对配子与胚胎培养条件的不断优化,辅助生殖技术的成功率显著提高,现已成为治疗不孕不育症的理想治疗措施之一。近年来,一系列辅助生殖相关技术,如卵子体外成熟、移植前遗传学诊断、单胚胎移植以及冷冻技术等获得了较大的发展,为降低常规体外受精—胚胎移植的费用、风险等提供了可能。该文主要就当前临床及实验性辅助生殖技术的相关研究进展作以综述。     

辅助生殖技术基础研究新进展

辅助生殖技术是近年解决不孕不育的重要手段.辅助生殖技术在卵母细胞的体外培养、卵巢及卵母细胞的冻存、卵巢的激活、胚胎的体外培育及移植等诸多方面已取得了不小的成绩,为人类生殖做出了巨大贡献.但辅助生殖技术仍存在许多问题,如胎儿出生后遗传印记的缺失,其机制还有待进一步研究.辅助生殖技术远期安全性也是值得重视的问题.辅助生殖技术有广阔的发展前景,值得辅助生殖工作者进行大量深入的研究并不断完善.现就辅助生殖技术在基础研究方面的新进展和亟待解决的问题进行综述.     

接受辅助生殖技术治疗患者的心理健康状况及其心理干预措施的研究进展

目前,辅助生殖技术(ART)是治疗不孕不育最有效的方法。不孕不育患者在接受ART治疗的不同阶段均面临不同的心理压力。接受ART治疗患者的临床成功妊娠率与其心理健康水平相关,若心理压力过大,可降低妊娠率和成功分娩率。因此,对接受ART治疗患者的心理干预,是ART治疗过程中重要的组成部分。笔者拟对接受ART治疗患者的心理健康状况及其心理干预措施的研究进展进行综述。     

提高辅助生殖技术的成功率

在世界范围内,约10%～15%的育龄夫妇受到不孕症的困扰。自1978年首例试管婴儿诞生以来,辅助生殖技术（ART）呈蓬勃发展之势,并由此引发相关领域在临床医学和分子生物学、分子遗传学等方面的快速进展。但至今,ART的成功率并不理想,且进步缓慢。探讨影响ART成功率的因素,并予以相应的改进,以改善ART成功率是临床医生和科研工作者不断追求的目标和努力的方向。选择适宜的促排卵方案、深入研究导致不孕症的病因、降低ART的并发症,将有助于ART的发展,更好地服务于患者。     

Possibilities and limits of assisted reproduction

The term assisted reproductive technologies (ART) describes all treatment procedures which include more than the natural intercourse to conceive. The most invasive procedure is intracytoplasmic sperm injection (ICSI), which was introduced in 1993. By ICSI the successful treatment of couples with severe male factor infertility, even in cases of azoospermia, became possible. In cases where only immature forms of spermatogenesis are present in the testicular tissue, pregnancies could also be achieved. The limiting factor with greatest influence on the success rate of ART procedures is the female's age. In this context the treatment of postmenopausal women by oocyte donation, as well as ooplasma donation to overcome the negative influence of the female's age on oocyte quality are extreme examples of ethically questionable ART procedures. Until now several 100,000 children worldwide have been born subsequent to ART and especially in vitro fertilisation. No increase in the malformation rate neither after IVF nor after IVF/ICSI have been reported so far. However, because of the lack of prospective controlled studies using standardised evaluation procedures and having enough statistical power to prove the security of ICSI for the newborn children, the German statutory health insurance bodies have ceased to pay ICSI costs as of July 1999. The data on the success of ICSI, the known data on the newborn and developing children and the decisions of the medical services of the German statutory health insurance bodies are presented in discussed in this paper.     

Preconception Care and Treatment with Assisted Reproductive Technologies

Couples with fertility problems seeking treatment with assisted reproductive technologies (ART) such as in vitro fertilization should receive preconception counseling on all factors that are provided when counseling patients without fertility problems. Additional counseling should address success rates and possible risks from ART therapies. Success rates from ART are improving, with the highest live birth rates averaging about 40% per cycle among women less than 35 years old. A woman’s age lowers the chance of achieving a live birth, as do smoking, obesity, and infertility diagnoses such as hydrosalpinx, uterine leiomyoma, or male factor infertility. Singletons conceived with ART may have lower birth weights. Animal studies suggest that genetic imprinting disorders may be induced by certain embryo culture conditions. The major risk from ovarian stimulation is multiple gestation. About one-third of live-birth deliveries from ART have more than one infant, and twins represent 85% of these multiple-birth children. There are more complications in multiple gestation pregnancies, infants are more likely to be born preterm and with other health problems, and families caring for multiples experience more stress. Transferring fewer embryos per cycle reduces the multiple birth rate from ART, but the patient may have to pay for additional cycles of ART because of a lower likelihood of pregnancy.

     

Cloning in companion animal, non-domestic and endangered species: can the technology become a practical reality?

Somatic cell nuclear transfer (SCNT) can provide a unique alternative for the preservation of valuable individuals, breeds and species. However, with the exception of a handful of domestic animal species, successful production of healthy cloned offspring has been challenging. Progress in species that have little commercial or research interest, including many companion animal, non-domestic and endangered species (CANDES), has lagged behind. In this review, we discuss the current and future status of SCNT in CANDES and the problems that must be overcome to improve pre- and post-implantation embryo survival in order for this technology to be considered a viable tool for assisted reproduction in these species.     

Access to assisted reproductive technologies in France: the emergence of the patients’ voice

Is there any ethical justification for limiting the reproductive autonomy and not make assisted reproductive technologies available to certain prospective parents? We present and discuss the results of an interdisciplinary clinical ethics study concerning access to assisted reproductive technologies (ART) in situations which are considered as ethically problematic in France (overage or sick parents, surrogate motherhood). The study focused on the arguments that people in these situations put forward when requesting access to ART. It shows that requester’s arguments are based on sound ethical values, and that their legitimacy is at least as strong as that of those used by doctors to question access to ART. Results reveal that the three implicit normative arguments that founded the law in 1994, which are still in force after the bioethics law revision in July 2011—the welfare of the child, the illegitimacy of a “right to a child,” and the defense of the so called “social order”—are challenged on several grounds by requesters as reasons for limiting their reproductive autonomy. Although these results are limited to exceptional situations, they are of special interest insofar as they give voice to the requesters’ own ethical concerns in the ongoing political debate over access to ART.     

维生素D与冻融胚胎移植结局关系的研究进展

冻融胚胎移植（FET）因可提高累积妊娠率,降低多胎率,预防卵巢过度刺激综合征的发生,目前已广泛应用于辅助生殖技术（ART）当中。关于FET妊娠结局的影响因素一直是临床研究关注的热点。近年,随着对维生素D的研究逐渐深入,发现维生素D除参与钙磷代谢、维持骨骼稳态外,还参与卵泡的发育、性激素的产生及胚胎的种植过程。维生素D的缺乏与多种妇科疾病有关,如子宫内膜异位症和多囊卵巢综合征等。目前维生素D在FET领域的研究并不多,且与FET结局之间的关系也尚未明确,本文对近年来维生素D与FET结局关系的研究进展进行综述。     

植入前遗传学诊断研究进展

近年来 ,随着辅助生殖技术如体外受精 胚胎移植技术 ,显微操作技术如卵胞浆内单精子注射技术的发展 ,因其携带遗传性缺陷的风险和生殖细胞畸变的比率明显高于正常人群 ,故在此基础上发展了植入前遗传学诊断技术。目前 ,此项技术已在国内外各生殖中心迅速开展 ,现对其研究进展作一综述。     

Ex vivo early embryo development and effects on gene expression and imprinting

The environment to which the mammalian embryo is exposed during the preimplantation period of development has a profound effect on the physiology and viability of the conceptus. It has been demonstrated that conditions that alter gene expression, and in some instances the imprinting status of specific genes, have all previously been shown to adversely affect cell physiology. Thus, questions are raised regarding the aetiology of abnormal gene expression and altered imprinting patterns, and whether problems can be averted by using more physiological culture conditions. It is also of note that the sensitivity of the embryo to its surroundings decreases as development proceeds. Post compaction, environmental conditions have a lesser effect on gene function. This, therefore, has implications regarding the conditions used for IVF and the culture of the cleavage stage embryo. The developmental competence of the oocyte also impacts gene expression in the embryo, and therefore superovulation has been implicated in abnormal methylation and imprinting in the resultant embryo. Furthermore, the genetics and dietary status of the mother have a profound impact on embryo development and gene expression. The significance of specific animal models for human assisted reproductive technologies (ART) is questioned, given that most cattle data have been obtained from in vitro-matured oocytes and that genes imprinted in domestic and laboratory animals are not necessarily imprinted in the human. Patients treated with ART have fertility problems, which in turn may predispose their gametes or embryos to greater sensitivities to the process of ART. Whether this is from the drugs involved in the ovulation induction or from the IVF, intracytoplasmic sperm injection or culture procedures themselves remains to be determined. Alternatively, it may be that epigenetic alterations are associated with infertility and symptoms are subsequently revealed through ART. Whatever the aetiology, continued long-term monitoring of the children conceived through ART is warranted.     

胚胎质量评估方法的研究进展

选择植入发育潜能更高的胚胎是辅助生殖技术(ART)中最主要的挑战之一。形态学评分法是目前运用最为广泛的胚胎质量评估方法,但是由于存在观察者的人为误差,导致该方法评价胚胎质量并不准确。近十年,代谢组学和蛋白质组学不断发展,结合傅立叶变换红外(FTIR)光谱、近红外光谱(NIR)、¹H-质子核磁共振(¹H-NMR)光谱、拉曼光谱技术等新技术的临床应用,可以精确检测胚胎培养液中的各种代谢产物,如丙酮酸、氨基酸、人类白细胞抗原(HLA)-G等。研究结果表明,妊娠组胚胎培养液代谢产物与未妊娠组不同。因此,无创性代谢组学及蛋白质组学对于胚胎质量的评估,或许可被运用于临床指导体外受精(IVF)方案的调整,选择最优质的移植胚胎。然而,形态学评分法、代谢组学和蛋白质组学均不能检测胚胎染色体异常,基因组学可弥补这一缺憾。通过胚胎移植前基因组检测和筛查,可以排除非整倍体性胚胎,从而提高ART助孕成功率。笔者拟就胚胎质量评估方法研究的最新进展进行阐述。     

中国青少年青春期生殖健康教育现状分析

目的 了解中国青少年的生殖健康教育现状并提出相应策略。方法 复习7年来在中国杂志及会议件汇编中刊登过的有关青少年生殖健康教育的章,并分析部分城市的中期引产案例。结果 北京绝大部分被调查的少女不了解女性生殖系统的解剖和生理。约半数北京青年不了解性传播疾病的预防知识。中国青少年中婚前性率及中期人工流产率较高,大部分农村高中生缺乏基本的性生理知识,不经常洗外生殖器,结论 中国青少年的生殖健康教育亟等加强,校内教育应与校外教育（家庭教育,社会教育）相结合。“青春期星光自护行动”,“健康少女课堂”等活动是成功的尝试,值得推广,应建立生殖健康教育促进学校网络。     

The role of animal studies in supporting human assisted reproductive technology

Although average success rates of human IVF have increased progressively during the past two decades, the efficiency of this technique, based on each embryo produced or transferred, is still low. High success rates are usually achieved by transferring several embryos to the patient, which is often associated with multiple pregnancies. The quality of in vitro produced embryos is a major area that needs attention. Because there is no in vivo database for human embryos, the properties of normal embryos are not known, and so it is difficult to know how to improve quality and viability. In addition, selection of the most viable embryos for transfer is a rather subjective process. The origins of human assisted reproductive technology (ART) are based on animal ART; however, the two areas of research (animal and human ART) appear to have become disconnected. Re-examination of progress in animal ART could help improve human embryo quality and thereby assist efforts to sustain high pregnancy rates with only one or two embryos transferred. Some key areas in which animal ART can help guide progress in human ART are discussed.     

Risk disparities in the globalisation of assisted reproductive technology: The case of Asia

This paper analyses the disparities in risks associated with biomedical technology focusing on the results of assisted reproductive technology (ART). ART among biomedical technologies transferred to Asia is a representative case that reveals in its clinical use and related scientific research the global politics of technology. This study notes the global politics at work in the recognition of and reaction to such risks. While many Asian countries aggressively pursue technological development, weak legislative and administrative regulations have created various problems and controversial cases. This study asserts that risks associated with technology are characterised as social facts not natural ones or mere ‘side effects’, since technological development and risk are closely intertwined.     

辅助生殖前子宫腺肌病合并不孕的治疗策略

目前已明确辅助生殖技术（assisted reproductive technology,ART）可以改善子宫腺肌病合并不孕患者的妊娠结局,但对于ART前需要采取何种治疗,尚无统一意见。从子宫腺肌病对ART妊娠结局影响的原因入手,重点综述能够改善子宫腺肌病ART结局的治疗措施,包括激素治疗,如促性腺激素释放激素激动剂（gonadotropin releasing hormone agonist,GnRHa）、米非司酮和孕三烯酮等,保守性手术治疗以及一些新手段,如子宫动脉栓塞术和高强度超声聚焦消融（high intensity focused ultrasound,HIFU）等。并针对目前存在的争议,如对药物治疗的具体用法、ART前是否需要腹腔镜手术切除病灶及手术的适应证和局限性、子宫动脉栓塞及HIFU等新手段对妊娠及新生儿有无影响、药物治疗或手术后ART方式及时机的选择等进行阐述。     

Non-adherence to antiretroviral treatment and unplanned treatment interruption among people living with HIV/AIDS in Cameroon: Individual and healthcare supply-related factors

In low-income countries, health system deficiencies may undermine treatment continuity and adherence to antiretroviral therapy (ART) that are crucial for the success of large-scale public ART programs. In addition to examining the effects of individual characteristics, on non-adherence to ART and treatment interruption behaviors – i.e. treatment interruption for more than 2 consecutive days during the previous 4 weeks, this study aims to extend our knowledge on the role played by healthcare supply-related characteristics in shaping these two treatment outcomes. These effects are examined using multilevel logistic models applied to a sub-sample of 2381 ART-treated patients followed-up in 27 treatment centers in Cameroon (ANRS-EVAL survey, 2006–2007).     

Suitability of the beagle dog as a test model for the tumorigenic potential of contraceptive steroids. "A short review".

The purpose of this short review is to assess the present state of knowledge on the suitability of the beagle dog as a test model for the tumorigenic potential of contraceptive steroids. The beagle dog differs markedly from other species, including man, as regards its reproductive physiology and endocrinology. Studies on the influence of contraceptive steroids on canine mammary gland, pituitary gland and uterus have led to the conclusion that the stimulation of development of mammary tumours in dogs by certain progestagens or progestagen-oestrogen combinations must be considered as being a species-specific effect, related to the high hormonal potency (progestational activity) of these compounds in the dog and their stimulatory effect on canine growth hormone. Based on the present state of our knowledge and because of the marked interspecies differences of action of contraceptive steroids in dog and man, the steroid-related canine mammary tumours, especially with regard to the doses necessary for contraception, are unlikely to be indicative of a potential hazard to the human female.