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BACKGROUND: An increased risk for intrauterine growth restriction in the affected member of like-sex twin pairs discordant for hypospadias has been reported. The purpose of this study was to document patterns of birth weight disparities in like-sex twins discordant for a variety of structural defects in order to determine if this is a general phenomenon seen in twins who are discordant for any malformation, is seen only in pairs discordant for certain specific malformations, or is unique to hypospadias. METHODS: Data were extracted from the Latin American Collaborative Study of Congenital Malformations (ECLAMC). Between 1967 and 1999, all like-sex twin pairs discordant for hypospadias or any other isolated defect that met the criteria of at least 5 discordant pairs for which birth weight was available on both twins were selected. All nonmalformed like-sex twin pairs in the ECLAMC data base collected over the same study years were selected as controls. RESULTS: A total of 216 discordant malformed like-sex twin pairs in 13 defect categories and 328 nonmalformed like-sex twin pairs met the criteria for inclusion. The proportion of affected infants who were > or =20% smaller than their co-twin was statistically significantly different from controls for hypospadias, heart defects, anencephaly, and esophageal atresia. CONCLUSIONS: Intrauterine growth restriction seen in the affected member of like-sex twin pairs discordant for hypospadias is not unique, but occurs as well in at least 3 additional structural malformations.  相似文献   

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  总被引:10,自引:0,他引:10  
BACKGROUND: The possible excess of congenital malformations in infants born after in vitro fertilization (IVF) has been much discussed in the literature, with controversial conclusions. This population based study is aimed at analyzing the presence of congenital malformations in a large group of infants born after IVF and to compare malformation risk both with that of all infants born and according to IVF method used. METHODS: Infants born after IVF during the period 1982-2001 were ascertained from all IVF clinics in Sweden. The presence of congenital malformations was identified from three national health registers: the Swedish Medical Birth Register, the Swedish Registry of Congenital Malformations, and the Swedish Hospital Discharge Register. The IVF children were compared with all children born in Sweden during the same period and recorded in the Swedish Medical Birth Register. RESULTS: Among 16,280 IVF children (30% conceived after intracytoplasmatic sperm injection [ICSI]) a 42% excess of any congenital malformation was found, explainable by parental characteristics and in some cases by the high rate of multiple births. Among these children, 8% had a congenital malformation, and 5% had a relatively severe condition. For neural tube defects, choanal atresia, and alimentary tract atresia, an additional risk increase was seen. There was no difference in malformation rate according to IVF method except for an excess of hypospadias after ICSI. CONCLUSIONS: An increased risk for congenital malformations occurs after IVF, similar for the different IVF techniques used, and mainly a consequence of parental characteristics. A few specific conditions show an extra increase in risk.  相似文献   

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The bladder exstrophy‐epispadias complex (BEEC) represents an anterior midline defect with variable expression comprising a spectrum of anomalies involving the abdominal wall, pelvis, urinary tract, genitalia, and occasionally the spine and anus. The vast majority of BEEC cases are classified as non‐syndromic and the etiology of this malformation is still unknown. This review presents the current state of knowledge on this multifactorial disorder, including historical retrospect, phenotypic and anatomical characterization, epidemiology, proposed developmental mechanisms, existing animal models, and implicated genetic and environmental components. These published lines of evidence argue strongly that BEEC occurs as a result of strong genetic predisposition that is yet to be deciphered. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

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Pregnancy loss is a common obstetric problem. Significant causes of miscarriage include genetic and epigenetic disorders of the embryo, immunological and endocrine factors, uterine malformations, improper embryo selection, and lifestyle. Perhaps a hitherto underappreciated cause of miscarriage may be an abnormal microbiota composition of the female reproductive system. Lactobacillus spp. is the most common bacteria within the reproductive tract. However, the protective role of Lactobacilli in the vagina has been well described in the literature, while it is still unknown what function Lactobacilli may have in the uterus. Moreover, new research shows that Lactobacillus spp. can have a role in miscarriage. However, both molecular and immunological mechanisms of host-Lactobacillus spp. interactions are not fully understood. Understanding these relationships will help address the importance and extent of the protective role of Lactobacillus spp. in miscarriage.  相似文献   

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The major genital responses of arousal in women are vasocongestion, resulting in tumescence of the vaginal walls, and vaginal lubrication, facilitating penile intromission and thrusting. During orgasm, several involuntary muscular reactions occur, the most adaptive being in the outer third of the vagina and the uterus. Uterine suction of the ejaculate seems to occur when the reproductive apparatus is functioning at full efficiency. Coitus may result in reflex ovulation. Indices of female nonhuman primate orgasm thus far proposed include rhythmic vaginal and anal contractions, hyperventilation, involuntary muscle tension, arm and leg spasms, grimacing, and uterine contractions. Orgasm in our species may exist as a result of phylogenetic inertia, not as a novel response selected during protohominid or hominid evolution. A theory for the evolutionary nature of orgasm in women states that the orgasmic vaginal contractions stimulate ejaculation. Reasons for the common asynchrony of this adaptive pattern are the usually lowered ejaculatory threshold because of non-species-typical orgasmic frequency in the male, and the frequently delayed female orgasm because of psychological inhibition and/or inadequate control and development of the pubococcygeus.  相似文献   

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In this study, evidence of novel, important interactions between a hyperactive Tn5 transposon recognition end sequence and hyperactive Tn5 transposase (Tnp) are presented. A hyperactive Tn5 end sequence, the mosaic end (ME), was isolated previously. The ME and a wild-type end sequence, the outside end (OE), differ at only three positions, yet transposition on the ME is tenfold higher than on the OE in vivo. Also, transposition on the ME is much more efficient than transposition on the OE in vitro. Here, we show that the decreased activity observed for the OE is caused by a defect in paired ends complex (PEC) formation resulting from the orientation of the A-T base-pair at position 4 of this end. Efficient PEC formation requires an interaction between the C5-methyl group (C5-Me) on the non-transferred strand thymine base at position 4 (T4) and Tnp. PEC formation on nicked substrates is much less affected by the orientation of the A-T base-pair at position 4, indicating that the C5-Me group is important only for steps preceding nicking. A recently determined co-crystal structure of Tn5 Tnp with the ME is discussed and a model explaining possible roles for the base-pair at position 4 is explored.  相似文献   

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Lauri Kangas  Mikko Unkila 《Steroids》2013,78(12-13):1273-1280
The multifactorial consequences of menopausal estrogen deficiency affect numerous tissues throughout the body. Supplemental hormonal therapies carry the burden of a risk/benefit ratio that must be highly individualized. Selective estrogen receptor modulators (SERMs) are estrogen receptor (ER) agonist/antagonists designed to induce benefits comparable with estrogen while minimizing adverse effects. Here, we review the estrogen agonist/antagonist profile of ospemifene, a novel triphenylethylene derivative recently approved to treat dyspareunia, a symptom of vulvar and vaginal atrophy (VVA) due to menopause, both preclinically and clinically. Ospemifene binds ERα and ERβ with approximately equal affinities. In preclinical models, ospemifene increased vaginal and uterine epithelial thickness and mucification to the same extent as estrogen. Ospemifene did not induce endometrial hyperplasia in animal models; there also was no stimulatory effect on endometrial cells. In rat and human mammary cells in vitro, ospemifene evokes a dose-dependent inhibition on estrogen-induced cell responses and cell proliferation, supporting an antiestrogenic effect in breast. In contrast, ospemifene has an estrogenic effect on bone, as seen by improved bone mineral density, strength, mass, and histomorphometry in preclinical models, consistent with improvements in markers of bone resorption and formation in postmenopausal women. Based on the preclinical evidence, ospemifene has beneficial estrogen-like effects on the vaginal epithelium, preliminary evidence to support a neutral endometrial profile, antiproliferative effects in breast, and estrogenic effects in bone. Taken together, especially regarding estrogen-like effects on the vaginal epithelium, ospemifene presents a profile of tissue-specific effects that appear novel among available SERMs and well-suited for the treatment of VVA.  相似文献   

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Videolaparoscopy was used to visualize the reproductive tract contractility of the squirrel monkey, Saimiri sciureus. This technique gives information on the nature, direction of propagation, duration, and frequency of contractions. At the times of ovulation, and embryo entry to the uterus, contractile activity was observed in both the uterus and oviduct, with the latter being more frequent. The dominant direction of propagation was towards the utero-tubal junction, and simultaneous contractions were frequently observed in both uterus and oviduct. © 1992 Wiley-Liss, Inc.  相似文献   

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目的 探讨乳酸菌阴道胶囊对妊娠中晚期外阴阴道假丝酵母菌病(VVC)患者不良妊娠结局的预防作用。方法 将136例妊娠中晚期VVC患者随机分为联合组和对照组各68例。联合组患者予以乳酸菌阴道胶囊(0.25 g/晚)及制霉菌素(50万IU/晚)联合阴道上药治疗(两药使用间隔4~6 h);对照组患者予以单纯的制霉菌素阴道上药治疗,剂量及用法同联合组,两组均连用10 d。观察并记录两组治疗后的临床效果,并比较两组不良妊娠结局。结果 治疗结束后1个月,在临床总有效率方面联合组患者明显优于对照组(92.65% vs 80.88%)(χ2=4.10,P0.05)。结论 乳酸菌阴道胶囊辅助治疗妊娠中晚期VVC的疗效较确切,能明显改善其临床症状及特征,对早产、胎膜早破和产褥病等不良妊娠结局具有良好的预防作用。  相似文献   

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