Measuring contraceptive values: An alternative approach

Previous assessments of individuals' values for various contraceptive consequences have employed one of four methodologies: free elicitation, direct ratings, multiple regression, or factor analysis. All four methodologies are flawed because they produce group rather than individual values, rely on rating scales, and fail to incorporate information regarding consequence trade-offs. Axiomatic conjoint measurement is proposed as an alternative methodology and used to determine individuals' values for a selected set of contraceptive consequences at two stages of the family-planning career.Preparation of this paper was supported in part by Grants HD-10802 and HD-14403 from the National Institute of Child Health and Human Development. Appreciation is due the Statistical Computing Facility of the University of California at Berkeley. Requests for reprints should be sent to the Publications Librarian, Center for Research on Judgment and Policy, Muenzinger Psychology Building, University of Colorado, Boulder, Colorado 80309-0344.     

Review article: Structure and function of the epididymis

Summary Testicular spermatozoa are functionally immature in that they cannot fertilize ova. It was first demonstrated by Young [171, 172] that spermatozoa undergo certain changes as they migrate through the epididymis. He proposed that spermatozoa ripen during epididymal transit. It is now known that specific maturational changes occur in spermatozoa during epididymal transit which result in their developing the ability to fertilize ova. Concomitant with this functional maturity are changes in spermatozoal morphology, motility, chemistry, permeability, density and metabolism. It is apparent that in some way not understood these changes are necessary for sperm to achieve the ability to complete the fertilization process. When these mechanisms are understood, we may be able to effectively treat conditions such as necrospermia or abnormally low sperm motility. Furthermore, with the development of the hamster-egg penetration test a new type of male infertility has become evident in recent years; the inability of otherwise normal sperm to penetrate an ovum. It is during epididymal transit that this ability is normally acquired. Thus, any insight into how sperm attain the capacity to penetrate an ovum could lead to an effective treatment of patients whose sperm do not have this ability. In addition, the epididymis holds significant promise as the site of action for a male contraceptive. Thus, it is the purpose of this review to describe the structure and function of the mammalian epididymis with particular emphasis on the factors regulating sperm maturation.     

长效可逆避孕措施在人工流产后即刻实施的效果评价

目的探究长效可逆避孕措施在人工流产后即刻实施的效果。方法从2017年7月-2018年7月,抽选在广州市增城区妇幼保健院行人工流产女性1200例,按照随机数字表法分为常规组(612例)和强化干预组(588例)。常规组给予常规流产后关爱(PAC)服务,强化干预组在常规PAC服务的基础上采用长效可逆避孕措施。对比两组长效可逆避孕措施使用情况、重复人工流产率以及避孕措施的持续时间情况。结果强化干预组的高效避孕措施使用率比常规组更高,同时重复人工流产率比常规组低,差异有统计学意义(P<0.05);强化干预组长效可逆避孕措施LARC(IUS/IUD)避孕术后6个月、1年使用率明显高于常规组,差异有统计学意义(P<0.05);复方口服避孕药优思悦(COC)避孕术后3个月、6个月、1年的使用率比常规组高,差异有统计学意义(P<0.05)。结论人工流产后即刻实施长效可逆避孕措施,可提升高效避孕措施的使用率,减少意外妊娠及再次人工流产的几率,值得推广。     

精子膜蛋白Cyritestin单抗对鼠精卵结合和融合的抑制作用及其意义

目的 通过观察精子膜蛋白Cyritestin单抗对体外鼠精－鼠结合和融合作用的影响,探讨该蛋白在受精过程中的作用。方法 应用鼠Cyritestin单抗,通过体外受精试验观察该单抗预孵育不同浓度精子后,对精－卵结合和融合功能的影响;应用免疫细胞化学方法确定Cyritestin在精子表面的特异性定位。结果 不同精子浓度下,Cyritestin单抗均可显著降低体外精－卵的结合和融合能力;可使精－卵结合指数降低37.18%－79.00%,平均60.33%;使精－卵融合的受精指数降低51.66%－77.01%,平均66.90%;受精率下降32.28%－76.15%,平均57.41%。在精子项体反应前后,Cytitestin在精子表面均特异性定位于精子头部赤道区域和项体内膜区域。结论 Cyritestin在精－卵的结合和融合中均发挥重要生理作用。该蛋白作为精子靶抗原开发避孕疫苗的可能性值得深入研究。     

Sexual and Reproductive Health （SRH） Problems among the Unmarried Youths in Sub-urban Shanghai： Needs for RH Education and Services

~~Subiects 6、Method A selj。dmtnl。ie)。ed ano。Iv。on。que。t。onna。,,e。u)。。。l。a.\.ondl。Jed among 7 304 youths aged betw。en j 7 and 24。n t。o to。n。V the sub。。。。ban a),。·l叶Shanghai.Results A total灯 18.4%叶。ubje’t。ha。,。/j。e,。sc。ual入e。po。。。enc。d,4%J/t)。lal。。had eoper。en。ed on。or more Indu。。d a/,o)t。on,a。。d cullZ].3yf V s。。bject。。ho j。。。,。。。。。tal八eI户erlence usedcontra’咛ti。es}-e只。liar八.Mult。var。ateLo厂。st。。e厂厂。。,l。…     

A Novel Contraceptive Vaccine： Design and Synthesis of the Chimeric Peptide Containing Multivalent Sperm-Specific Epitopes

Objective To develop a novel multivalent chimeric peptide vaccine for bisexual fertility regulation Materials & Methods On the basis of the amino acid sequence of the two peptides respectively selected from the mouse sperm/testis-specific proteins SP17 and Cyritestin, and one T cell epitope in bovine ribonuclease (RNase), a novel chimeric peptide consisting of 35 amino acid was designed and subsequently synthesized on the 430A peptide synthesizer. After being emulified with the equivalence Freund's adjuvant, the peptide with 35 amino acid residues was used to immunogenity the female BALB/c mice to investigate its immunity.Results The peptide was successfully synthesized, after being purified in high performance liquid chromatography (HPLC), its purity reached 95%. The specific antisera collected from the immunogenity mice could identify the corresponding proteins of testis tissues of mice, rats and human. The highest specific IgG titer in serum was 1:6 000, while the IgA titer in the washing of vaginal mucous membrane was 1:300.Conclusion The antibodies from the peptide with specific amino acid sequence can identify the original antigens, and stimulate powerful specific humoral immunity in mice. It provides a experimental bases for polyvalent contraceptive vaccine study.     

Contraception: Contraception with NORPLANT(R) implants

NORPLANT^® progestogen-only implant contraception providesseveral years of effective protection against pregnancy followinga single application. It is reversible whenever desired, withreturn to normal fertility. Drug release and concentrationsare maximal in the first month of use, when a set of six capsulesreleases 85/µg/day of levonorgestrel. Release is 25–30/µg/dayat 60 months. Circulating drug concentrations and pregnancyrates vary inversely with body weight at placement, but evenamong heavier women, failure rates are below those of oral contraceptivesin the general population. Side-effects are most marked at theinitiation of use. Disruption of normal menstrual patterns occursin 70–80% of recipients initially. Menstrual blood lossis decreased, however, and most women experience modest increasesin haemoglobin. Headache, acne, other skin or hair problems,changes of weight and of mood and abdominal pain, are the mostcommon side-effects attributed to NORPLANT^® contraception.The frequency of occurrence of side-effects diminishes withincreased duration of use. The comparative paucity of majorside-effects, coupled with the method‘s convenience andeffectiveness and its very long action have made NORPLANT^®implants highly acceptable in both developing and developedcountries.     

The recent saga of cardiovascular disease and safety of oral contraceptives

This review presents detailed risk estimates from relevant epidemiological and other studies on the comparative safety of second and third generation oral contraceptives (OC). Written with the intention of presenting a repository of the available information, it also discourses briefly into the symptomatology and diagnosis of diseases associated with OC use and presents some of the critical comments made about various epidemiological analyses. A general critique including observations and opinions of various investigators completes the review. We stress that our own opinions on the various studies, or an attempt to adjudge the relative safety of second and third generation OC, are not given since they form the substance of our second paper which completes this symposium.     

The public health implications of the 1995 'pill scare'

The warning issued by the UK Committee on Safety Medicines in October 1995, followed by their 'Dear Doctor' letter of October 18, 1995, that oral contraceptive pills containing gestodene or desogestrel were associated with a higher risk of venous thromboembolism has had a negative impact on public heath. A significant number of women either switched brands or ceased contraception altogether following the announcement. National data suggest a strong association between the pill scare and a substantial increase in the number of unintended pregnancies, particularly significant among younger women, with use of oral contraception falling from 40 to 27% of under 16s between 1995-1996 and 1996-1997. The resulting cost of the increase in births and abortions to the National Health Service has been estimated at about Pound Sterling 21 million for maternity care and from Pound Sterling 46 million for abortion provision. The level of risk should, in future, be more carefully assessed and advice more carefully presented in the interests of public health.     

The effects of feeding an Asian or Western diet on sperm numbers, sperm quality and serum hormone levels in cynomolgus monkeys (Macaca fascicularis) injected with testosterone enanthate (TE) plus depot medroxyprogesterone acetate (DMPA)

The aim of this study was to elucidate the effects of an Asian diet compared to a Western diet on sperm numbers and quality, and serum hormones in cynomolgus monkeys (Macaca fascicularis) injected with testosterone enanthate (TE) plus depot medroxyprogesterone acetate (DMPA). Thirty male monkeys were divided into three groups of ten animals each. The first group (control) was fed with standard diet 'monkey chow' (9% fat, 13% protein, 78% carbohydrate); the second group was fed an 'asian' diet (15% fat, 15% protein, 70% carbohydrate); the third group was fed a 'Western' diet (35% fat, 25% protein, 40% carbohydrate). These diets were administered from the beginning (adaptation) until the experiment was terminated. Three months after the adaptation period, all groups were injected with 20 mg TE (once per week) and 25 mg DMPA (once every 6 weeks) for 18 weeks, while TE injections were continued for another 6 weeks. There were no differences in sperm numbers and quality, or in hormone levels between the first and second groups. In both of these groups azoospermia was achieved in 100% of animals, while in the third group only 70% achieved azoospermia. In all 3 groups, spermatozoa were once again detectable by week 33. However, by the end of the study at week 39, sperm numbers in the first and second groups reached only severe oligozoospermia (two animals remained azoospermic in the first group) while in the third group, numbers had returned to normozoospermia. The quality of spermatozoa during and after the treatment in the third group was better than in the first and second groups. Hormone concentrations decreased more rapidly in both the first and second groups, compared to the third group, while the recovery period was slower in the first and second groups, compared to the third group. It is concluded that different formula diets result in differential decreases in sperm numbers and quality, and in hormone concentrations in M. fascicularis injected with TE in combination with DMPA. Animals fed with either monkey chow or an Asian diet exhibited more severe and prolonged decreases in these parameters than did animals fed with a Western diet.