Nestorone: clinical applications for contraception and HRT

The 19-nor derivatives of progesterone are referred to as "pure" progestational molecules as they bind almost exclusively to the progesterone receptor (PR) without interfering with receptors of other steroids. In this category is Nestorone, which has strong progestational activity and antiovulatory potency with no androgenic or estrogenic activity in vivo. These properties make it highly suitable for use in contraception and hormonal therapy (HT). Due to its high potency, very low doses of Nestorone may be delivered via long-term sustained-release delivery systems. Nestorone, 75 or 100 microg per day, released by vaginal ring has suppressed ovulation in women, with inhibition of follicular maturation. A vaginal ring releasing both 150 microg of Nestorone and 15 microg of ethinyl estradiol per day has effectively suppressed ovulation for 13 consecutive cycles. Nestorone has also been used effectively in a single implant for contraception in breastfeeding women and shows promise for use in transdermal systems as a contraceptive or for HT when combined with estrogen.     

Vaginal rings for contraception in lactating women

Contraceptive methods for breastfeeding women should be safe for the mother and infant and should not interfere with lactation. Progestin-only methods meet these conditions and can be used from the sixth week postpartum. Because all progestins are excreted in milk, those that are insufficiently active by the oral route are preferable to avoid any possible effect on the baby. These steroids, however, must be administered to the mother by a non-oral route. Initially, progesterone was administered subdermally to test this concept. Subsequently, a progesterone vaginal ring was developed to be used continuously for 3 to 4 months and replaced with a new device, as needed, until weaning. Clinical trials have shown a high contraceptive efficacy (over 98.5%) and safety. The gross continuation rate of this method is approximately 40% at 12 months of use, with use-related problems being the main reason for discontinuation (26.8%). Currently, a Nestorone vaginal ring is under development, delivering 50 microg of Nestorone per day. It may be used continuously for up to one year, even if weaning occurs earlier. Both of these progestin-only rings prolong lactational amenorrhea to 10 to 12 months, which represents a health benefit and convenience for many women. The registration of the progesterone vaginal ring, developed as a contraceptive method to be used exclusively during lactation, has been approved in Chile and Perú. The fact that it is a user-controlled long-term contraceptive that delivers a natural hormone makes it an attractive option for many women.     

Nestorone: a progestin with a unique pharmacological profile

Nestorone(R) (Nestorone 16-methylene-17alpha-acetoxy-19-norpregn-4-ene-3,20-dione), formerly referred to as ST 1435, is a potent progestin when given parenterally via sustained release formulations. The pharmacological profile of Nestorone was compared with that of levonorgestrel and 3-keto-desogestrel by steroid receptor binding studies and by in vivo bioassays in rats and rabbits. 3-Keto-desogestrel showed the highest binding affinity to progesterone receptors (PR) followed by Nestorone, levonorgestrel, and progesterone. The binding affinity of Nestorone to androgen receptors (AR) was 500- to 600-fold less than that of testosterone. However, both levonorgestrel and 3-keto-desogestrel showed significant binding (40 to 70% of testosterone) to AR. None of the progestins bound to estrogen receptors (ER). The progestational activity of Nestorone, levonorgestrel, and progesterone was compared using McPhail index in immature rabbits and pregnancy maintenance and ovulation inhibition tests in rats after subcutaneous (s.c.) administration. In all three tests, Nestorone was the most potent progestin. The progestational activity of Nestorone was also compared after oral and s.c. administration in rabbits. The potency of Nestorone was over 100-fold higher upon s.c. administration than via the oral route. The androgenic activity of progestins, based on the stimulation of ventral prostate (androgenic target) and levator ani (anabolic target) growth in castrated immature rats, showed good correlation with their binding affinity to AR. Nestorone showed no androgenic or anabolic activity. Nestorone did not bind to sex hormone binding globulin (SHBG), whereas both levonorgestrel and 3-keto-desogestrel showed significant binding to SHBG. The estrogenic/antiestrogenic activity of Nestorone was investigated in immature ovariectomized rats. In contrast to estradiol and levonorgestrel, Nestorone showed no uterotropic activity in ovariectomized rats. Despite significant binding to glucocorticoid receptors (GR), Nestorone showed no glucocorticoid activity in vivo. It is concluded that a strong progestational activity, combined with lack of androgenic, estrogenic, and glucocorticoid-like activities, confer special advantages to Nestorone for use in contraception and hormone replacement therapy.     

Subdermal contraceptive implants

Subdermal contraceptive implants involve the delivery of a steroid progestin from polymer capsules or rods placed under the skin. The hormone diffuses out slowly at a stable rate, providing contraceptive effectiveness for 1–5 years. The period of protection depends upon the specific progestin and the type of polymer. Advantages of progestin implants include long term contraceptive action without requiring the user's or provider's attention, low dose of highly effective contraception without the use of estrogen, and fertility is readily reversible after the removal of implants. The levonorgestrel implant Norplant R system is the only one that has been approved for distribution. The contraceptive efficacy of Norplant is the highest observed amongst the most effective methods with an annual pregnancy rate of 0.2 during the first and second year and 1.1 on the fifth year. Menstrual problems are the main reason for the discontinuation of Norplant and 9% of women stopped using it during the first year of treatment. Other implants are still under development trying to simplify the method by reducing the number of units and to introduce other progestins that may minimize side effects. Norplant-2 was designed to release the same dose of progestin from only two covered rods. Evaluation of 1400 women enrolled, indicates that over 2 years the cumulative pregnancy rate is below 0.5 per 100 women. There are three single implants under development: Nestorone, 3-Keto-desogestrel and Uniplant that are expected to be effective for 1–2 years. Phase II clinical trials with Nestorone have been completed and no pregnancies have been observed in 1570 woman-months of use. Bleeding irregularities occurred in 20–30% of the women but there were only four terminations because of bleeding problems. A multricentric study is ongoing with a newly designed 3-keto-desogestrel implant named Implanon, which releases approx. 60 μg/day of the hormone. The objectives of this study are to assess contraceptive efficacy, safety and acceptability of Implanon. Another multricentric study is ongoing with Uniplant, which releases nomegestrol acetate with a duration of action for only 1 year. The objectives of the trial are to study the endocrine profile of Uniplant users and to evaluate the efficacy and acceptability of the method.     

阴道菌群移植治疗细菌性阴道炎的发展现状及展望

细菌性阴道炎 (Bacterial vaginosis,BV) 是由患者阴道内菌群失调导致的一类疾病。当前常规的抗生素疗法可进一步加剧阴道菌群失衡、破坏阴道酸性环境、导致耐药,因此其对BV治愈率低,复发率高。作为一种新兴的活菌疗法,阴道菌群移植 (Vaginal microbiota transplantation,VMT) 直接将健康妇女完整的阴道菌群“嫁接”给患者,可迅速恢复患者阴道菌群的平衡,改善患者的整体健康。文中对VMT的发展历程进行了回顾,讨论了VMT发展过程中面临的难题及发展方向,以期寻求新的治疗BV的策略,加速VMT的临床应用。     

定君生调整自然分娩后阴道菌群失调的临床探讨

目的了解自然分娩后阴道菌群的改变及其危害,探讨定君生用于恢复自然分娩后阴道菌群失调的效果。方法分别对57例正常体检妇女、50例晚期妊娠妇女和45例自然分娩产后妇女进行阴道pH检测,同时取阴道分泌物进行细菌培养。另外,选择产后42d来我院复查的产妇72例,随机分为两组,定君生组42例,连续应用定君生10d,对照组30例,对其中已存在阴道感染的患者应用达克宁栓或复方甲硝唑栓进行治疗,疗程均为10d,对比分析两组的阴道炎发生情况。结果产后阴道乳酸杆菌检出率明显低于孕前期和妊娠期（P〈0．01）,产后阴道pH高于孕前期,两者之间差异有非常显著性（P〈0．01）。产后阴道厌氧菌的比例下降,非正常菌和条件致病菌增多。产后42d细菌和念珠菌性阴道病的发生率为15．3％,产后3个月定君生组细菌和念珠菌性阴道病的发生率均明显低于对照组（P〈0．05）。结论自然分娩可导致阴道菌群失调,使产后妇女易患细菌和念珠菌性阴道病,应用定君生可恢复阴道内乳酸杆菌的优势地位,对于防治产后细菌和念珠菌性阴道病具有重要作用。     

34例胎膜早破孕妇妊娠晚期阴道微生态及免疫因子变化状况分析

目的：胎膜早破是一种常见但发生机制十分复杂的妊娠并发症。在所有的早产儿中,孕妇胎膜早破的比例高达33％。本研究针对胎膜早破产妇妊娠晚期阴道微生态及免疫因子的变化情况,分析阴道内茵群失调或局部免疫反应与胎膜早破的关系,为临床研究提供实验数据。方法：回顾性分析我院于2010年7月-2013年3月收治的34例胎膜早破孕妇的临床资料,同时选取于我院进行健康体检的妇女及产前检查的健康孕妇各34例作为对照。采集所有研究对象的阴道分泌物,对比分析各组样本中病原微生物的分布及免疫因子的浓度。结果：胎膜早破组乳酸杆菌的检出率要明显低于健康妇女组与健康孕妇组（79．4％VS70．6％VS34．1,X2=8．438,P〈0．05）,三组研究对象其他茵属分布的差异比较无统计学意义（P〉0．05）;胎膜早破组阴道分泌物IL-6浓度与TNF．仪浓度要显著高于健康妇女组与健康孕妇组（P〈0．05）。结论：胎膜早破产妇阴道内的菌群分布与健康女性及孕妇有所不同,阴道内茵群失调及局部的免疫反应可能会导致胎膜旱破的发生。     

Synthesis and biological activity of a new progestogen, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3, 20-dione acetate

The progestational activity of second- and third-generation progestins in oral contraceptives were markedly increased by addition of an 18-methyl group. A new progestin, the 18-methyl analog of Nestorone, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3,2 0-dione acetate (10), was synthesized. The relative binding affinity and biologic activity of 10 was compared with Nestorone, levonorgestrel, and progesterone using a binding assay for rat progesterone receptors, the Clauberg assay in the rabbit, and by assessing pregnancy maintenance in the rat. These studies, as summarized in Table 4, show that 10 is three to ten times more potent than Nestorone. The addition of the 18-methyl group to Nestorone markedly increased its potency as noted above, but is unlikely to change its rate of delivery from sustained release systems. 10 should be ideally suited for administration by implants or small skin patches.     

Effects of a One Year Reusable Contraceptive Vaginal Ring on Vaginal Microflora and the Risk of Vaginal Infection: An Open-Label Prospective Evaluation

Background

A contraceptive vaginal ring (CVR) containing Nestorone® (NES) and ethinyl estradiol (EE) that is reusable for 1- year (13 cycles) is under development. This study assessed effects of this investigational CVR on the incidence of vaginal infections and change in vaginal microflora.

Methods

There were 120 women enrolled into a NES/EE CVR Phase III trial and a microbiology sub-study for up to 1- year of cyclic product use. Gynecological examinations were conducted at baseline, the first week of cycle 6 and last week of cycle 13 (or during early discontinuation visits). Vaginal swabs were obtained for wet mount microscopy, Gram stain and culture. The CVR was removed from the vagina at the last study visit and cultured. Semi-quantitative cultures for Lactobacillus, Gardnerella vaginalis, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, anaerobic gram negative rods (GNRs), Candida albicans and other yeasts were performed on vaginal and CVR samples. Vaginal infections were documented throughout the study.

Results

Over 1- year of use, 3.3% of subjects were clinically diagnosed with bacterial vaginosis, 15.0% with vulvovaginal candidiasis, and 0.8% with trichomoniasis. The detection rate of these three infections did not change significantly from baseline to either Cycle 6 or 13. Nugent scores remained stable. H₂O₂-positive Lactobacillus dominated vaginal flora with a non-significant prevalence increase from 76.7% at baseline to 82.7% at cycle 6 and 90.2% at cycle 13, and a median concentration of 10⁷ colony forming units (cfu) per gram. Although anaerobic GNRs prevalence increased significantly, the median concentration decreased slightly (10⁴ to 10³cfu per gram). There were no significant changes in frequency or concentrations of other pathogens. High levels of agreement between vaginal and ring surface microbiota were observed.

Conclusion

Sustained use of the NES/EE CVR did not increase the risk of vaginal infection and was not disruptive to the vaginal ecosystem.

Trial Registration

ClinicalTrials.gov NCT00263341, NCT00455156     

Endothelial function across an oral contraceptive cycle in women using levonorgestrel and ethinyl estradiol

Oral contraceptive pills (OCPs) are a popular contraception method. Currently, lower-dose ethinyl estradiol formulations are most commonly prescribed, although they have been linked to increased arterial vascular risk. The aim of this study was to investigate endothelial function in healthy young women using lower-dose ethinyl estradiol OCPs. We examined flow-mediated, endothelium-dependent and nitroglycerin-mediated, endothelium-independent vasodilation of the brachial artery, comparing two doses of ethinyl estradiol/levonorgestrel OCPs in 15 healthy young women on two study days: once during the active phase and once during the placebo phase of an OCP cycle. Group low dose (LD) (n=7) active pills contained 150 microg levonorgestrel/30 microg ethinyl estradiol versus Group very low dose (VLD) (n=8) with 100 microg levonorgestrel/20 microg ethinyl estradiol. Endothelium-dependent vasodilation was lower during the active phase in Group VLD (5.33 +/- 1.77% vs. 7.23 +/- 2.60%; P=0.024). This phase difference was not observed in Group LD (8.00 +/- 0.970% vs. 7.61 +/- 1.07%; P=0.647). Endothelium-independent vasodilation did not differ between phases in either group. Finally, we measured endothelium-dependent vasodilation in two additional women who received 10 microg of unopposed ethinyl estradiol. Endothelium-dependent vasodilation was increased by unopposed ethinyl estradiol compared with the placebo phase (10.88 +/- 2.34% vs. 6.97 +/- 1.83%). These results suggest that levonorgestrel may antagonize the activity of ethinyl estradiol. Thus both the progestin type and estradiol dose need to be considered when assessing arterial vascular risk of OCP use in women.     

A Temperature-Monitoring Vaginal Ring for Measuring Adherence

BackgroundProduct adherence is a pivotal issue in the development of effective vaginal microbicides to reduce sexual transmission of HIV. To date, the six Phase III studies of vaginal gel products have relied primarily on self-reporting of adherence. Accurate and reliable methods for monitoring user adherence to microbicide-releasing vaginal rings have yet to be established.MethodsA silicone elastomer vaginal ring prototype containing an embedded, miniature temperature logger has been developed and tested in vitro and in cynomolgus macaques for its potential to continuously monitor environmental temperature and accurately determine episodes of ring insertion and removal.ResultsIn vitro studies demonstrated that DST nano-T temperature loggers encapsulated in medical grade silicone elastomer were able to accurately and continuously measure environmental temperature. The devices responded quickly to temperature changes despite being embedded in different thickness of silicone elastomer. Prototype vaginal rings measured higher temperatures compared with a subcutaneously implanted device, showed high sensitivity to diurnal fluctuations in vaginal temperature, and accurately detected periods of ring removal when tested in macaques.ConclusionsVaginal rings containing embedded temperature loggers may be useful in the assessment of product adherence in late-stage clinical trials.     

Biomechanical and morphological properties of the multiparous ovine vagina and effect of subsequent pregnancy

Pelvic floor soft tissues undergo changes during the pregnancy. However, the degree and nature of this process is not completely characterized. This study investigates the effect of subsequent pregnancy on biomechanical and structural properties of ovine vagina. Vaginal wall from virgin, pregnant (in their third pregnancy) and parous (one year after third vaginal delivery) Swifter sheep (n = 5 each) was harvested. Samples for biomechanics and histology, were cut in longitudinal axis (proximal and distal regions). Outcome measurements describing Young’s modulus, ultimate stress and elongation were obtained from stress-strain curves. For histology samples were stained with Miller's Elastica staining. Collagen, elastin and muscle cells and myofibroblasts contents were estimated, using image processing techniques. Statistical analyses were performed in order to determine significant differences among experimental groups. Significant regional differences were identified. The proximal vagina was stiffer than distal, irrespective the reproductive status. During the pregnancy proximal vagina become more compliant than in parous (+47.45%) or virgin sheep (+64.35%). This coincided with lower collagen (−15 to −21%), higher elastin (+30 to +60%), and more smooth muscle cells (+17 to +37%). Vaginal tissue from parous ewes was weaker than of virgins, coinciding with lower collagen (−10%), higher elastin (+50%), more smooth muscle cells (+20%). It could be proposed that after pregnancy biomechanical properties of vagina do not recover to those of virgins. Since elastin has a significant influence on the compliance of soft tissues and collagen is the main “actor” regarding strength, histological analysis performed in this study justifies the mechanical behavior observed.     

Immunoglobulin G, Plasma Cells, and Lymphocytes in the Murine Vagina after Vaginal or Parenteral Immunization with Attenuated Herpes Simplex Virus Type 2

This investigation evaluated immunity to vaginal herpes simplex virus type 2 (HSV-2) infection after local or parenteral immunization with attenuated HSV-2. Vaginal immunization induced sterilizing immunity against challenge with a high dose of wild-type virus, whereas parenteral immunizations protected against neurologic disease but did not entirely prevent infection of the vagina. Vaginal immunization caused 86- and 31-fold increases in the numbers of immunoglobulin G (IgG) plasma cells in the vagina at 6 weeks and 10 months after immunization, whereas parenteral immunizations did not increase plasma cell numbers in the vagina. Vaginal secretion/serum titer ratios and specific antibody activities in vaginal secretions and serum indicated that IgG viral antibody was produced in the vagina and released into vaginal secretions at 6 weeks and 10 months after vaginal immunization but not after parenteral immunizations. In contrast to the case for plasma cells, the numbers of T and B lymphocytes in the vagina were similar in vaginally and parenterally immunized mice. Also, lymphocyte numbers in the vagina were markedly but similarly increased by vaginal challenge with HSV-2 in both vaginally and parenterally immunized mice. Lymphocyte recruitment to the vagina after virus challenge appeared to involve memory lymphocytes, because it was not observed in nonimmunized mice. Thus, local vaginal immunization with attenuated HSV-2 increased the number of IgG plasma cells in the vagina and increased vaginal secretion/serum titer ratios to 3.0- to 4.7-fold higher than in parenterally immunized groups but caused little if any selective homing of T and B lymphocytes to the vagina.     

阴道消毒治疗护理器的临床应用

目的:探讨妇科手术后病人的阴道护理的新方法、新手段,旨在提高临床疗效。方法:随机选取398例妇科手术后的病人做常规会阴护理,对其中172例使用阴道消毒治疗器做阴道护理。结果:试验组的172例术后病人在尿路感染率、阴道炎、宫颈炎、息肉发生率明显低于常规组。结论:妇科手术后病人在应用新式阴道消毒治疗器后,不但能弥补传统阴道护理方法的不足,还明显扩大了会阴护理的消毒范围,减少妇科手术后阴道、尿道逆行感染的发生率,有效的提高临床疗效。新式阴道消毒护理器应是目前临床应用中的较理想的护理方法和手段。     

Development and evaluation of a vaginal ring device for sustained delivery of HIV microbicides to non-human primates

Background  There is considerable interest in developing coitally independent, sustained release formulations for long-term administration of HIV microbicides. Vaginal ring devices are at the forefront of this formulation strategy.
Methods  Non-medicated silicone elastomer vaginal rings were prepared having a range of appropriate dimensions for testing vaginal fit in pig-tailed and Chinese rhesus macaques. Cervicovaginal proinflammatory markers were evaluated. Compression testing was performed to compare the relative flexibility of various macaque and commercial human rings.
Results  All rings remained in place during the study period and no tissue irritation or significant induction of cervicovaginal proinflammatory markers or signs of physical discomfort were observed during the 8-week study period.
Conclusions  Qualitative evaluation suggests that the 25 × 5-mm ring provided optimal fit in both macaque species. Based on the results presented here, low-consistency silicone elastomers do not cause irritation in macaques and are proposed as suitable materials for the manufacture of microbicide-loaded vaginal rings.     

Contraception with progestogens and progesterone during lactation

The growth and development of breastfed infants whose mothers used the contraceptive implants Norplant® containing levonorgestrel and the injectable containing norethisterone enanthate were studied. Each group comprised of 120 women who initiated the use during the 5th to 7th week postpartum and were compared with a similar number of IUD using mothers. The breastfeeding performance did not differ between groups. The infants of the three groups performed similarly as regards their physical growth and health as well as the time of acquisition of the various milestones of psychomental development. A vaginal ring releasing 10 mg of the “natural” progesterone per 24 h was tested in breastfeeding mothers. The continuous use of the ring produced a serum level of progesterone around 4 ng/ml. This was effective in augmenting lactational infertility even through the later phases of breastfeeding when such an effect starts to wane off. The use of the ring proved to be acceptable and had no ill-effect on breastfeeding or infant growth or health. Using the natural progesterone as a contraceptive adds a new measure of safety, since the amount of the steroid secreted in the mother's milk will not be effectively absorbed from the infant's gut. These studies suggest the possibility of using two new methods for breastfeeding mothers; Norplant and the progesterone vaginal contraceptive ring. These can be initiated early postpartum, whenever this is considered needed.     

纵向研究妊娠期妇女的阴道微生态状况

目的分析妊娠期妇女阴道微生态状况的纵向变化。方法选择健康无症状单胎妊娠期妇女50例,分别于孕早期（10.2±2.1）周、孕中期（24.6±3.7）周、孕晚期（33.2±3.4）周,取其阴道分泌物,进行pH、H2O2含量检测及细菌培养,并经革兰染色后在油镜下观察,进行阴道微生态（阴道菌群的密集度、多样性、优势菌、炎症反应状况等）状况评价。结果 （1）50例孕妇中,孕早期38例（76%）阴道微生态正常,其中31例（81.58%）整个孕期维持阴道微生态正常,7例（18.42%）孕妇于孕中期或孕晚期转变为阴道微生态失调;12例（24%）孕早期阴道微生态失调,其中6例（50%）于孕中期或孕晚期转变为阴道微生态正常。（2）无症状性细菌性阴道病随着孕周增加部分可自然消退40%（2/5）。（3）H2O2阳性、阴道pH低者易从阴道微生态失调转为阴道微生态正常。结论妊娠期阴道微生态是动态变化的,部分细菌性阴道炎可自然消退,H2O2阳性及低阴道pH为维持正常阴道微生态的重要因素。     

乳杆菌治疗女性阴道炎相关研究进展

健康妇女的阴道中存在黏膜免疫系统及乳杆菌与其它微生物群的动态平衡,对维持其自净及宿主健康起重要作用。乳杆菌在阴道内具有抵抗内源性和外源性病原菌生长繁殖的作用。当这种平衡被打破时,乳杆菌减少而其他微生物大量繁殖,造成阴道炎的发生。对于阴道炎的治疗,临床可以采用微生态治疗——合理使用抗生素和微生态调节剂的应用,从而起到杀菌、修复阴道上皮和恢复阴道微生态环境的作用。     

阴道微生态失调与早产相关性研究进展

健康育龄妇女的阴道微生态环境呈现多样性,阴道内微生物菌群以乳杆菌为主。乳杆菌可维持妇女阴道微环境平衡和保持阴道酸性环境以抑制致病性病原体生长。当乳杆菌比例低至致病阈值以下或无乳杆菌存在时,阴道微环境的菌群组成转变成以兼性需氧及厌氧菌为主。越来越多的证据表明,怀孕期间阴道菌群的异常与早产、及因早产和围产期结局不佳导致的潜在新生儿后遗症有关。本文综述了妊娠期阴道菌群的变化、细菌性阴道炎与早产发生风险等方面的问题,目的是帮助临床医生确定怀孕期间有阴道炎症状女性是否可接受治疗,从而降低早产、早产胎膜早破、绒毛膜羊膜炎和母胎传染病的发病率。