Ovarian cancer(OC) is the seventh most commonly diagnosed cancer among women in the world and the tenth most common in China. Epithelial OC is the most predominant pathologic subtype, with five major histotypes that d...Ovarian cancer(OC) is the seventh most commonly diagnosed cancer among women in the world and the tenth most common in China. Epithelial OC is the most predominant pathologic subtype, with five major histotypes that differ in origination,pathogenesis, molecular alterations, risk factors, and prognosis. Genetic susceptibility is manifested by rare inherited mutations with high to moderate penetrance. Genome-wide association studies have additionally identified 29 common susceptibility alleles for OC, including 14 subtype-specific alleles. Several reproductive and hormonal factors may lower risk, including parity, oral contraceptive use, and lactation, while others such as older age at menopause and hormone replacement therapy confer increased risks. These associations differ by histotype, especially for mucinous OC, likely reflecting differences in etiology. Endometrioid and clear cell OC share a similar, unique pattern of associations with increased risks among women with endometriosis and decreased risks associated with tubal ligation. OC risks associated with other gynecological conditions and procedures, such as hysterectomy,pelvic inflammatory disease, and polycystic ovarian syndrome, are less clear. Other possible risk factors include environmental and lifestyle factors such as asbestos and talc powder exposures, and cigarette smoking. The epidemiology provides clues on etiology,primary prevention, early detection, and possibly even therapeutic strategies.展开更多
Invertase （INV） hydrolyzes sucrose into glucose and fructose, thereby playing key roles in primary metabolism and plant development. Based on their pH optima and sub-cellular locations, INVs are categorized into cel...Invertase （INV） hydrolyzes sucrose into glucose and fructose, thereby playing key roles in primary metabolism and plant development. Based on their pH optima and sub-cellular locations, INVs are categorized into cell wall, cytoplasmic, and vacuolar subgroups, abbreviated as CWlN, CIN, and VlN, respectively. The broad importance and implications of INVs in plant development and crop productivity have attracted enormous interest to examine INV function and regulation from multiple perspectives. Here, we review some exciting advances in this area over the last two decades, focusing on （1） new or emerging roles of INV in plant development and regulation at the post-translational level through interaction with inhibitors, （2） cross-talk between INV-mediated sugar signaling and hormonal control of development, and （3） sugar- and INV-mediated responses to drought and heat stresses and their impact on seed and fruit set. Finally, we discuss major questions arising from this new progress and outline future directions for unraveling mechanisms underlying INV-mediated plant development and their potential applications in plant biotechnology and agriculture.展开更多
The worldwide distribution and extensive genetic diversity of the whitefly,Bemisia tabaci,has long been recognized.However,the levels of separation within B.tabaci and the nomenclature of the various genetic groups ha...The worldwide distribution and extensive genetic diversity of the whitefly,Bemisia tabaci,has long been recognized.However,the levels of separation within B.tabaci and the nomenclature of the various genetic groups have been a subject of debate.Recent phylogenetic analyses indicate that B.tabaci is a complex composed of 28 morphologically indistinguishable species.In this article,we first review the debate and difficulties associated with B.tabaci＇s taxonomy and systematics,and argue for the need to apply the biological species concept in order to elucidate B.tabaci＇s systematics.We summarize the accumulated genetic and behavioural data on reproductive incompatibilities evident amongst phylogenetic mtCOI groups of B.tabaci.Crossing studies have been conducted with 14 of the 28 putative species covering 54 reciprocal inter-species pairs,and observations on mating behaviour have been conducted for seven species pairs.Data from both crossing trials and behavioural observations indicate a consistent pattern of reproductive isolation among the putative species.We then discuss the technical and conceptual complexities associated with crossing experiments and behavioural observations designed to reveal reproductive incompatibility.Finally,we elaborate on a strategy for further clarifying the pattern of reproductive isolation between B.tabaci groups and propose future research directions on the systematics of this complex.展开更多
Sperm DNA damage is prevalent among infertile men and is known to influence natural reproduction. However, the impact of sperm DNA damage on assisted reproduction outcomes remains controversial. Here, we conducted a m...Sperm DNA damage is prevalent among infertile men and is known to influence natural reproduction. However, the impact of sperm DNA damage on assisted reproduction outcomes remains controversial. Here, we conducted a meta-analysis of studies on sperm DNA damage （assessed by SCSA, TUNEL, SCD, or Comet assay） and clinical pregnancy after IVF and/or ICSI treatment from MEDLINE, EMBASE, and PUBMED database searches for this analysis. We identified 41 articles （with a total of 56 studies） including 16 IVF studies, 24 ICSI studies, and 16 mixed （IVF ＋ ICSI） studies. These studies measured DNA damage （by one of four assays： 23 SCSA, 18 TUNEL, 8 SCD, and 7 Comet） and included a total of 8068 treatment cycles （3734 IVF, 2282 ICSI, and 2052 mixed IVF ＋ ICSI）. The combined OR of 1.68 （95% Ch 1.49-1.89; P 〈 0.0001） indicates that sperm DNA damage affects clinical pregnancy following IVF and/or ICSI treatment. In addition, the combined OR estimates of IVF （16 estimates, OR = 1.65; 95% CI： 1.34-2.04; P 〈 0.0001）, ICSI （24 estimates, OR = 1.31; 95% Ch 1.08-1.59; P = 0.0068）, and mixed IVF ＋ ICSI studies （16 estimates, OR = 2.37; 95% Ch 1.89-2.97; P〈 0.0001） were also statistically significant. There is sufficient evidence in the existing literature suggesting that sperm DNA damage has a negative effect on clinical pregnancy following IVF and/or ICSI treatment.展开更多
This study examined the misdiagnosis and delayed diagnosis factors for ectopic pregnancy（EP） and heterotopic pregnancy（HP） after in vitro fertilization and embryo transfer（IVF-ET） in an attempt to reduce the dia...This study examined the misdiagnosis and delayed diagnosis factors for ectopic pregnancy（EP） and heterotopic pregnancy（HP） after in vitro fertilization and embryo transfer（IVF-ET） in an attempt to reduce the diagnostic error. Clinical data of patients who underwent IVF-ET treatment and had clinical pregnancy from 12463 cycles were retrospectively analyzed. Their findings of serum β-hCG test and transvaginal ultrasonography were also obtained during follow-up. These patients were divided into two groups according to the diagnosis accuracy of EP/HP： early diagnosis and misdiagnosis/delayed diagnosis. The results showed that the incidence of EP and HP was 3.8%（125/3286） and 0.8%（27/3286） respectively for IVF/ICSI-ET cycle, and 3.8%（55/1431） and 0.7%（10/1431） respectively for frozen-thawed embryo transfer（FET） cycle. Ruptured EP occurred in 28 patients due to initial misdiagnosis or delayed diagnosis. Related factors fell in 3 categories：（1） clinician factors： misunderstanding of patients＇ medical history, insufficient training in ultrasonography and unawareness of EP and HP;（2） patient factors： noncompliance with medical orders and lack of communication with clinicians;（3） complicated conditions of EP： atypical symptoms, delayed elevation of serum β-hCG level, early rupture of cornual EP, asymptomatic in early gestation and pregnancy of unknown location. All the factors were interwoven, contributing to the occurrence of EP and HP. It was concluded that complicated conditions are more likely to affect the diagnosis accuracy of EP/HP after IVF-ET. Transvaginal ultrasonography should be performed at 5 weeks of gestation. Intensive follow-up including repeated ultrasonography and serial serum β-hCG tests should be performed in patients with a suspicious diagnosis at admission.展开更多
Objective： To provide an evidence-based, consistent assessment of the burden of breast cancer attributable to reproductive factors （RFs, including nulliparity, mean number of children, age at first birth and breastf...Objective： To provide an evidence-based, consistent assessment of the burden of breast cancer attributable to reproductive factors （RFs, including nulliparity, mean number of children, age at first birth and breastfeeding）, use of oral contraceptives （OCs, restricted to the age group of 15-49 years）, and hormone replacement therapy （HRT）, as well as of the burden of ovarian cancer attributable to the mean number of children in China in 2005. Methods： We derived the prevalence of these risk factors and the relative risk of breast and ovarian cancer from national surveys or large-scale studies conducted in China. In the case of RFs, we compared the exposure distributions in 2001 and counterfactual exposure. Results： Exposure of RFs in 2002 was found to account for 6.74% of breast cancer, corresponding to 9,617 cases and 2,769 deaths, and for 2.78% of ovarian cancer （712 cases, 294 deaths）. The decrease in mean number of children alone was responsible for 1.47% of breast cancer and 2.78% of ovarian cancer. The prevalence of OC use was 1.74% and the population attributable fraction （PAF） of breast cancer was 0.71%, corresponding to 310 cases and 90 deaths. The PAF of breast cancer due to HRT was 0.31%, resulting in 297 cases and 85 deaths. Conclusion： RFs changes in China contributed to a sizable fraction of breast and ovarian cancer incidence and mortality, whereas HRT and OCs accounted for relatively low incidence of breast cancer in China.展开更多
Diagnosis of male infertility has mainly been based on the World Health Organization （WHO） manual-based semen parameter＇s concentration, motility and morphology. It has, however, become apparent that none of these ...Diagnosis of male infertility has mainly been based on the World Health Organization （WHO） manual-based semen parameter＇s concentration, motility and morphology. It has, however, become apparent that none of these parameters are reliable markers for evaluation of the fertility potential of a couple. A search for better markers has led to an increased focus on sperm chromatin integrity testing in fertility work-up and assisted reproductive techniques. During the last couple of decades, numerous sperm DNA integrity tests have been developed. These are claimed to be characterized by a lower intraindividual variation, less intralaboratory and interlaboratory variation and thus less subjective than the conventional sperm analysis. However, not all the sperm chromatin integrity tests have yet been shown to be of clinical value. So far, the test that has been found to have the most stable clinical threshold values in relation to fertility is the sperm chromatin structure assay （SCSA）, a flow cytometric test that measures the susceptibility of sperm DNA to acid-induced DNA denaturation in situ. Sperm DNA fragmentation as measured by SCSA has shown to be an independent predictor of successful pregnancy in first pregnancy planners as well as in couples undergoing intrauterine insemination, and can be used as a tool in investigation, counseling and treatment of involuntary childlessness. More conflicting data exist regarding the role of sperm DNA fragmentation in relation to fertilization, pre-embryo development and pregnancy outcome in in vitro fertilization and intracytoplasmic sperm injection （ICSI）.展开更多
Abstract： With the rapid development of assisted reproductive technology, various reproductive disorders have been effectively addressed. Acupuncture-like therapies, including electroacupuncture （EA） and transcutan...Abstract： With the rapid development of assisted reproductive technology, various reproductive disorders have been effectively addressed. Acupuncture-like therapies, including electroacupuncture （EA） and transcutaneous electrical acupoint stimulation （TEAS）, become more popular world-wide. Increasing evidence has demonstrated that EA and TEAS are effective in treating gynecological disorders, especially infertility. This present paper describes how to select acupoints for the treatment of infertility from the view of theories of traditional Chinese medicine and how to determine critical parameters of electric pulses of ENTEAS based on results from animal and clinical studies. It summarizes the principles of clinical application of EA/rEAS in treating various kinds of reproductive disorders, such as polycystic ovary syndrome （PCOS）, pain induced by oocyte retrieval, diminished ovarian reserve, embryo transfer, and oligosperrnia/ asthenospermia. The possible underlying mechanisms mediating the therapeutic effects of EA/TEAS in reproductive medicine are also examined.展开更多
Many advances in genetic selection, nutrition, housing and disease control have been incorporated into modern pork production since the 1950s resulting in highly prolific females and practices and technologies, which ...Many advances in genetic selection, nutrition, housing and disease control have been incorporated into modern pork production since the 1950s resulting in highly prolific females and practices and technologies, which significantly increased efficiency of reproduction in the breeding herd. The objective of this manuscript is to review the literature and current industry practices employed for reproductive management. In particular the authors focus on assisted reproduction technologies and their application for enhanced productivity. Modern maternal line genotypes have lower appetites and exceptional lean growth potential compared to females of 20 yr ago. Thus, nutrient requirements and management techniques and technologies, which affect gilt development and sow longevity, require continuous updating. Failure to detect estrus accurately has the greatest impact on farrowing rate and litter size. Yet, even accurate estrus detection will not compensate for the variability in the interval between onset of estrus and actual time of ovulation. However, administration of GnRH analogs in weaned sows and in gilts after withdrawal of altrenogest do overcome this variability and thereby synchronize ovulation, which makes fixed-time AI practical. Seasonal infertility, mediated by temperature and photoperiod, is a persistent problem. Training workers in the art of stockmanship is of increasing importance as consumers become more interested in humane animal care. Altrenogest, is used to synchronize the estrous cycle of gilts, to prolong gestation for 2-3 d to synchronize farrowing and to postpone post-weaning estrus. P.G. 600~ is used for induction of estrus in pre-pubertal gilts and as a treatment to overcome seasonal anestrous. Sperm cell numbers/dose of semen is significantly less for post cervical AI than for cervical AI. Real-time ultrasonography is used to determine pregnancy during wk 3-5. PGF2a effectively induces farrowing when administered within two d of normal gestation length. Ovulation synchronization, single fix展开更多
Aims In this study,we examined the extent to which between-species leaf size variation relates to variation in the intensity of leaf production in herbaceous angiosperms.Leaf size variation has been most commonly inte...Aims In this study,we examined the extent to which between-species leaf size variation relates to variation in the intensity of leaf production in herbaceous angiosperms.Leaf size variation has been most commonly interpreted in terms of biomechanical constraints(e.g.affected by plant size limitations)or in terms of direct adaptation associated with leaf size effects in optimizing important physiological functions of individual leaves along environmental gradients(e.g.involving temperature and moisture).An additional interpretation is explored here,where adaptation may be more directly associated with the number of leaves produced and where relatively small leaf size then results as a trade-off of high‘leafing intensity’—i.e.number of leaves produced per unit plant body size.Methods The relationships between mean individual leaf mass,number of leaves and plant body size were examined for 127 species of herbaceous angiosperms collected from natural populations in southern Ontario,Canada.Important Findings In all,88%of the variation in mean individual leaf mass across species,spanning four orders of magnitude,is accounted for by a negative isometric(proportional)trade-off relationship with leafing intensity.These results parallel those reported in recent studies of woody species.Because each leaf is normally associated with an axillary bud or meristem,having a high leafing intensity is equivalent to having a greater number of meristems per unit body size—i.e.a larger‘bud bank’.According to the‘leafing intensity premium’hypothesis,because an axillary meristem represents the potential to produce either a new shoot or a reproductive structure,high leafing intensity should confer greater architectural and/or reproductive plasticity(with relatively small leaf size required as a trade-off).This greater plasticity,we suggest,should be especially important for smaller species since they are likely to suffer greater suppression of growth and reproduction from competition within multi-species vegetation.Accord展开更多
Background:With the development of assisted reproductive technology(ART)and its increasing success rate in the mainland of China,more attention has been paid to the safety of ART.In this study,we explored the associat...Background:With the development of assisted reproductive technology(ART)and its increasing success rate in the mainland of China,more attention has been paid to the safety of ART.In this study,we explored the associations between conception by ART and pregnancy/perinatal complications,and neonatal outcomes compared with similar outcomes following spontaneous conception.Methods:This retrospective cohort study of pregnancies over a 3-year period(2013-2015)was performed at Beijing Obstetrics and Gynecology Hospital,Beijing,China.Subjects were divided into two groups:conception by ART(n=2256)or spontaneous conception(n=6768).According to different fertilization modes,the ART group was divided into in vitro fertilization(IVF,n=1873)and intracytoplasmic sperm injection(ICSI,n=383)subgroups.The ART group was also divided into two different embryo transfer methods;fresh embryo transfer(ET,n=1583)and frozen embryo transfer(FET,n=673)subgroups.Pregnancy complications,perinatal complications,and neonatal outcomes of the enrolled subjects were investigated and analyzed by univariate analysis and multivariate logistic regression.Results:After adjustment for maternal age,gravidity,parity,maternal education,smoking,alcohol consumption,and body mass index(BMI),pregnancies conceived by ART were associated with a significantly increased incidence of gestational diabetes mellitus(GDM;OR 1.88,95%CI 1.56-2.27),gestational hypertension(OR 2.18,95%CI 1.83-2.60),and intrahepatic cholestasis of pregnancy(ICP)(OR 2.79,95%CI 2.15-3.64),compared with spontaneous conception.These associations were similar for the singleton group.In the twin group,only the incidence of ICP was significantly higher than in controls.We found that pregnancies conceived by ART were associated with perinatal complications,including placental abruption(OR 2.14,95%CI 1.33-3.45),premature rupture of membranes(PROM;OR 1.24,95%CI 1.06-1.45),postpartum hemorrhage(OR 2.89,95%CI 2.33-3.59)and polyhydramnios(OR 2.01,95%CI 1.29-3.16).The singleton group had a similar result展开更多
Aim： To promote the provision of reproductive health services to young people by exploring the attitudes and perceptions of university students in Shanghai, China, toward reproductive health. Methods： From July 2004...Aim： To promote the provision of reproductive health services to young people by exploring the attitudes and perceptions of university students in Shanghai, China, toward reproductive health. Methods： From July 2004 to May 2006, 5 243 students from 14 universities in Shanghai took part in our survey. Topics covered the demands of reproductive health-care services, attitudes towards and experience with sex, exposure to pornographic material, and knowledge on sexual health and sexually transmitted infections （STIs）/AIDS. Results： Of the 5 067 students who provided valid answer sheets, 50.05% were female and 49.95% were male, 14.86% were medical students, and 85.14% had non-medical backgrounds. A total of 38.4% of respondents had received reproductive health education previously. The majority of students supported school-based reproductive health education, and also acquired information about sex predominantly from books, schoolmates, and the Internet. Premarital sexual behavior was opposed by 17.7% of survey participants, and 37.5% could identify all the three types of STIs listed in the questionnaire. Although 83.7% knew how HIV is transmitted, only 55.7% knew when to use a condom and 57.8% knew that the use of condoms could reduce the risk of HIV infection. Conclusion： The reproductive health service is lagging behind current attitudes and demands of university students. Although students＇ attitudes towards sexual matters are liberal, their knowledge about reproductive health and STIs/AIDS is still limited. It is therefore necessary to provide effective and confidential reproductive health services to young people.展开更多
Aim： To investigate the effect of formaldehyde （FA） on testes and the protective effect of vitamin E （VE） against oxidative damage by FA in the testes of adult rats. Methods： Thirty rats were randomly divided in...Aim： To investigate the effect of formaldehyde （FA） on testes and the protective effect of vitamin E （VE） against oxidative damage by FA in the testes of adult rats. Methods： Thirty rats were randomly divided into three groups： （1） control; （2） FA treatment group （FAt）; and （3） FAt ＋ VE group. FAt and FAt ＋ VE groups were exposed to FA by inhalation at a concentration of 10 mg/m^3 for 2 weeks. In addition, FAt ＋ VE group were orally administered VE during the 2-week FA treatment. After the treatment, the histopathological and biochemical changes in testes, as well as the quantity and quality of sperm, were observed. Results： The testicular weight, the quantity and quality of sperm, the activities of superoxide dismutase （SOD）, glutathione peroxidase （GSH-Px） and glutathione （GSH） were significantly decreased whereas the level of malondialdehyde （MDA） was significantly increased in testes of rats in FAt group compared with those in the control group. VE treatment restored these parameters in FAt ＋ VE group. In addition, microscopy with hematoxylin-eosin （HE） staining showed that seminiferous tubules atrophied, seminiferous epithelial cells disintegrated and shed in rats in FAt group and VE treatment significantly improved the testicular structure in FAt ＋ VE group. Conclusion： FA destroys the testicular structure and function in adult rats by inducing oxidative stress, and this damage could be partially reversed by VE.展开更多
This study was conducted to investigate the effects of dietary supplementation with yeast culture(YC)and organic selenium(Se)during late gestation and lactation on reproductive performance,milk quality,piglet preweani...This study was conducted to investigate the effects of dietary supplementation with yeast culture(YC)and organic selenium(Se)during late gestation and lactation on reproductive performance,milk quality,piglet preweaning performance,antioxidant capacity,and secretion of immunoglobulin in multiparous sows.A total of 160 healthy cross-bred sows(Landrace×Yorkshire,mean parity 4.1±0.3)were randomly assigned to 4 groups as follows:1)high nutrient(HN),3,420 kcal/kg digestible energy(DE)and 18.0%crude protein(CP);2)low nutrient(LN),3,240 kcal/kg DE and 16.0%CP;3)LN+YC,LN diet+10 g/kg YC;4)LN+YC+Se,LN diet+10 g/kg YC+organic Se(1 mg/kg Se).Feeding trials of sows started from d 85 of pregnancy to d 35 of lactation.Compared with sows in the LN group,sows fed the LN+YC+Se diet had greater litter weaning weight,average litter gain,and milk fat content(14-d and25-d milk)(P<0.05).The content of malonaldehyde(MDA)(colostrum and 14-d milk)was lesser,and the activity of glutathione peroxidase(GSH-Px)(colostrum and 25-d milk)was greater when sows were fed the LN+YC+Se diet,compared with sows fed the LN diet(P<0.05).Supplementation of YC and organic Se in the nutrient-restricted diet improved sows’reproductive performance and pig weaning body weight by enhancing the antioxidant capacity and fat content in milk.展开更多
Research concerning the psychosocial aspects of infertility and infertility treatment focuses more often on women than men. The aim of this review was to synthesize the English-language evidence related to the psychol...Research concerning the psychosocial aspects of infertility and infertility treatment focuses more often on women than men. The aim of this review was to synthesize the English-language evidence related to the psychological and social aspects of infertility in men and discuss the implications of these reports for clinical care and future research. A structured search identified 73 studies that reported data concerning the desire for fatherhood and the psychological and social aspects of diagnosis, assisted reproductive technology （ART） treatment and unsuccessful treatment among men with fertility difficulties. The studies are diverse in conceptualisation, design, setting and data collection, but the findings were reasonably consistent. These studies indicated that fertile and infertile childless men of reproductive age have desires to experience parenthood that are similar to those of their female counterparts; in addition, diagnosis and initiation of treatment are associated with elevated infertility-specific anxiety, and unsuccessful treatment can lead to a state of lasting sadness. However, rates of clinically significant mental health problems among this patient population are no higher than in the general population. Infertile men who are socially isolated, have an avoidant coping style and appraise stressful events as overwhelming, are more vulnerable to severe anxiety than men without these characteristics. Men prefer oral to written treatment information and prefer to receive emotional support from infertility clinicians rather than from mental health professionals, self-help support groups or friends. Nevertheless, structured, facilitated psycho-educational groups that are didactic but permit informal sharing of experiences might be beneficial. There are gaps in knowledge about factors governing seeking, persisting with and deciding to cease treatment; experiences of invasive procedures; parenting after assisted conception; adoption and infertility-related grief and shame among men. Few resource-cons展开更多
文摘Ovarian cancer(OC) is the seventh most commonly diagnosed cancer among women in the world and the tenth most common in China. Epithelial OC is the most predominant pathologic subtype, with five major histotypes that differ in origination,pathogenesis, molecular alterations, risk factors, and prognosis. Genetic susceptibility is manifested by rare inherited mutations with high to moderate penetrance. Genome-wide association studies have additionally identified 29 common susceptibility alleles for OC, including 14 subtype-specific alleles. Several reproductive and hormonal factors may lower risk, including parity, oral contraceptive use, and lactation, while others such as older age at menopause and hormone replacement therapy confer increased risks. These associations differ by histotype, especially for mucinous OC, likely reflecting differences in etiology. Endometrioid and clear cell OC share a similar, unique pattern of associations with increased risks among women with endometriosis and decreased risks associated with tubal ligation. OC risks associated with other gynecological conditions and procedures, such as hysterectomy,pelvic inflammatory disease, and polycystic ovarian syndrome, are less clear. Other possible risk factors include environmental and lifestyle factors such as asbestos and talc powder exposures, and cigarette smoking. The epidemiology provides clues on etiology,primary prevention, early detection, and possibly even therapeutic strategies.
文摘Invertase （INV） hydrolyzes sucrose into glucose and fructose, thereby playing key roles in primary metabolism and plant development. Based on their pH optima and sub-cellular locations, INVs are categorized into cell wall, cytoplasmic, and vacuolar subgroups, abbreviated as CWlN, CIN, and VlN, respectively. The broad importance and implications of INVs in plant development and crop productivity have attracted enormous interest to examine INV function and regulation from multiple perspectives. Here, we review some exciting advances in this area over the last two decades, focusing on （1） new or emerging roles of INV in plant development and regulation at the post-translational level through interaction with inhibitors, （2） cross-talk between INV-mediated sugar signaling and hormonal control of development, and （3） sugar- and INV-mediated responses to drought and heat stresses and their impact on seed and fruit set. Finally, we discuss major questions arising from this new progress and outline future directions for unraveling mechanisms underlying INV-mediated plant development and their potential applications in plant biotechnology and agriculture.
基金funded by the National Basic Research Program of China(2009CB119203)the National NaturalScience Foundation of China(30730061)the ChinaAgriculture Research System(CARS-25-B-08)
文摘The worldwide distribution and extensive genetic diversity of the whitefly,Bemisia tabaci,has long been recognized.However,the levels of separation within B.tabaci and the nomenclature of the various genetic groups have been a subject of debate.Recent phylogenetic analyses indicate that B.tabaci is a complex composed of 28 morphologically indistinguishable species.In this article,we first review the debate and difficulties associated with B.tabaci＇s taxonomy and systematics,and argue for the need to apply the biological species concept in order to elucidate B.tabaci＇s systematics.We summarize the accumulated genetic and behavioural data on reproductive incompatibilities evident amongst phylogenetic mtCOI groups of B.tabaci.Crossing studies have been conducted with 14 of the 28 putative species covering 54 reciprocal inter-species pairs,and observations on mating behaviour have been conducted for seven species pairs.Data from both crossing trials and behavioural observations indicate a consistent pattern of reproductive isolation among the putative species.We then discuss the technical and conceptual complexities associated with crossing experiments and behavioural observations designed to reveal reproductive incompatibility.Finally,we elaborate on a strategy for further clarifying the pattern of reproductive isolation between B.tabaci groups and propose future research directions on the systematics of this complex.
文摘Sperm DNA damage is prevalent among infertile men and is known to influence natural reproduction. However, the impact of sperm DNA damage on assisted reproduction outcomes remains controversial. Here, we conducted a meta-analysis of studies on sperm DNA damage （assessed by SCSA, TUNEL, SCD, or Comet assay） and clinical pregnancy after IVF and/or ICSI treatment from MEDLINE, EMBASE, and PUBMED database searches for this analysis. We identified 41 articles （with a total of 56 studies） including 16 IVF studies, 24 ICSI studies, and 16 mixed （IVF ＋ ICSI） studies. These studies measured DNA damage （by one of four assays： 23 SCSA, 18 TUNEL, 8 SCD, and 7 Comet） and included a total of 8068 treatment cycles （3734 IVF, 2282 ICSI, and 2052 mixed IVF ＋ ICSI）. The combined OR of 1.68 （95% Ch 1.49-1.89; P 〈 0.0001） indicates that sperm DNA damage affects clinical pregnancy following IVF and/or ICSI treatment. In addition, the combined OR estimates of IVF （16 estimates, OR = 1.65; 95% CI： 1.34-2.04; P 〈 0.0001）, ICSI （24 estimates, OR = 1.31; 95% Ch 1.08-1.59; P = 0.0068）, and mixed IVF ＋ ICSI studies （16 estimates, OR = 2.37; 95% Ch 1.89-2.97; P〈 0.0001） were also statistically significant. There is sufficient evidence in the existing literature suggesting that sperm DNA damage has a negative effect on clinical pregnancy following IVF and/or ICSI treatment.
基金supported by the National Natural Science Foundation of China(No.81170574)the National Key Basic Research Development Plan of China(973 Program)(No.2007CB948104)+1 种基金Key Science and Technology Projects of Guangzhou(No.11C22120737)Comprehensive Strategic Sciences Cooperation Projects of Guangdong Province and Chinese Academy(No.04020416)
文摘This study examined the misdiagnosis and delayed diagnosis factors for ectopic pregnancy（EP） and heterotopic pregnancy（HP） after in vitro fertilization and embryo transfer（IVF-ET） in an attempt to reduce the diagnostic error. Clinical data of patients who underwent IVF-ET treatment and had clinical pregnancy from 12463 cycles were retrospectively analyzed. Their findings of serum β-hCG test and transvaginal ultrasonography were also obtained during follow-up. These patients were divided into two groups according to the diagnosis accuracy of EP/HP： early diagnosis and misdiagnosis/delayed diagnosis. The results showed that the incidence of EP and HP was 3.8%（125/3286） and 0.8%（27/3286） respectively for IVF/ICSI-ET cycle, and 3.8%（55/1431） and 0.7%（10/1431） respectively for frozen-thawed embryo transfer（FET） cycle. Ruptured EP occurred in 28 patients due to initial misdiagnosis or delayed diagnosis. Related factors fell in 3 categories：（1） clinician factors： misunderstanding of patients＇ medical history, insufficient training in ultrasonography and unawareness of EP and HP;（2） patient factors： noncompliance with medical orders and lack of communication with clinicians;（3） complicated conditions of EP： atypical symptoms, delayed elevation of serum β-hCG level, early rupture of cornual EP, asymptomatic in early gestation and pregnancy of unknown location. All the factors were interwoven, contributing to the occurrence of EP and HP. It was concluded that complicated conditions are more likely to affect the diagnosis accuracy of EP/HP after IVF-ET. Transvaginal ultrasonography should be performed at 5 weeks of gestation. Intensive follow-up including repeated ultrasonography and serial serum β-hCG tests should be performed in patients with a suspicious diagnosis at admission.
基金supported by International Agency for Research on Cancer (Lyon, France) (No. CRA No GEE/08/19)supported in part by the Fogarty International Clinical Research Scholars and Fellows Program at Vanderbilt University (R24 TW007988)
文摘Objective： To provide an evidence-based, consistent assessment of the burden of breast cancer attributable to reproductive factors （RFs, including nulliparity, mean number of children, age at first birth and breastfeeding）, use of oral contraceptives （OCs, restricted to the age group of 15-49 years）, and hormone replacement therapy （HRT）, as well as of the burden of ovarian cancer attributable to the mean number of children in China in 2005. Methods： We derived the prevalence of these risk factors and the relative risk of breast and ovarian cancer from national surveys or large-scale studies conducted in China. In the case of RFs, we compared the exposure distributions in 2001 and counterfactual exposure. Results： Exposure of RFs in 2002 was found to account for 6.74% of breast cancer, corresponding to 9,617 cases and 2,769 deaths, and for 2.78% of ovarian cancer （712 cases, 294 deaths）. The decrease in mean number of children alone was responsible for 1.47% of breast cancer and 2.78% of ovarian cancer. The prevalence of OC use was 1.74% and the population attributable fraction （PAF） of breast cancer was 0.71%, corresponding to 310 cases and 90 deaths. The PAF of breast cancer due to HRT was 0.31%, resulting in 297 cases and 85 deaths. Conclusion： RFs changes in China contributed to a sizable fraction of breast and ovarian cancer incidence and mortality, whereas HRT and OCs accounted for relatively low incidence of breast cancer in China.
文摘Diagnosis of male infertility has mainly been based on the World Health Organization （WHO） manual-based semen parameter＇s concentration, motility and morphology. It has, however, become apparent that none of these parameters are reliable markers for evaluation of the fertility potential of a couple. A search for better markers has led to an increased focus on sperm chromatin integrity testing in fertility work-up and assisted reproductive techniques. During the last couple of decades, numerous sperm DNA integrity tests have been developed. These are claimed to be characterized by a lower intraindividual variation, less intralaboratory and interlaboratory variation and thus less subjective than the conventional sperm analysis. However, not all the sperm chromatin integrity tests have yet been shown to be of clinical value. So far, the test that has been found to have the most stable clinical threshold values in relation to fertility is the sperm chromatin structure assay （SCSA）, a flow cytometric test that measures the susceptibility of sperm DNA to acid-induced DNA denaturation in situ. Sperm DNA fragmentation as measured by SCSA has shown to be an independent predictor of successful pregnancy in first pregnancy planners as well as in couples undergoing intrauterine insemination, and can be used as a tool in investigation, counseling and treatment of involuntary childlessness. More conflicting data exist regarding the role of sperm DNA fragmentation in relation to fertilization, pre-embryo development and pregnancy outcome in in vitro fertilization and intracytoplasmic sperm injection （ICSI）.
基金Project supported by the Special Research Fund for the Public Welfare Industry of Health of China(No.201302013)
文摘Abstract： With the rapid development of assisted reproductive technology, various reproductive disorders have been effectively addressed. Acupuncture-like therapies, including electroacupuncture （EA） and transcutaneous electrical acupoint stimulation （TEAS）, become more popular world-wide. Increasing evidence has demonstrated that EA and TEAS are effective in treating gynecological disorders, especially infertility. This present paper describes how to select acupoints for the treatment of infertility from the view of theories of traditional Chinese medicine and how to determine critical parameters of electric pulses of ENTEAS based on results from animal and clinical studies. It summarizes the principles of clinical application of EA/rEAS in treating various kinds of reproductive disorders, such as polycystic ovary syndrome （PCOS）, pain induced by oocyte retrieval, diminished ovarian reserve, embryo transfer, and oligosperrnia/ asthenospermia. The possible underlying mechanisms mediating the therapeutic effects of EA/TEAS in reproductive medicine are also examined.
文摘Many advances in genetic selection, nutrition, housing and disease control have been incorporated into modern pork production since the 1950s resulting in highly prolific females and practices and technologies, which significantly increased efficiency of reproduction in the breeding herd. The objective of this manuscript is to review the literature and current industry practices employed for reproductive management. In particular the authors focus on assisted reproduction technologies and their application for enhanced productivity. Modern maternal line genotypes have lower appetites and exceptional lean growth potential compared to females of 20 yr ago. Thus, nutrient requirements and management techniques and technologies, which affect gilt development and sow longevity, require continuous updating. Failure to detect estrus accurately has the greatest impact on farrowing rate and litter size. Yet, even accurate estrus detection will not compensate for the variability in the interval between onset of estrus and actual time of ovulation. However, administration of GnRH analogs in weaned sows and in gilts after withdrawal of altrenogest do overcome this variability and thereby synchronize ovulation, which makes fixed-time AI practical. Seasonal infertility, mediated by temperature and photoperiod, is a persistent problem. Training workers in the art of stockmanship is of increasing importance as consumers become more interested in humane animal care. Altrenogest, is used to synchronize the estrous cycle of gilts, to prolong gestation for 2-3 d to synchronize farrowing and to postpone post-weaning estrus. P.G. 600~ is used for induction of estrus in pre-pubertal gilts and as a treatment to overcome seasonal anestrous. Sperm cell numbers/dose of semen is significantly less for post cervical AI than for cervical AI. Real-time ultrasonography is used to determine pregnancy during wk 3-5. PGF2a effectively induces farrowing when administered within two d of normal gestation length. Ovulation synchronization, single fix
基金Natural Sciences and Engineering Research Council of Canada Research Grant(14552 to L.W.A.),Undergraduate Student Research Award to T.W.
文摘Aims In this study,we examined the extent to which between-species leaf size variation relates to variation in the intensity of leaf production in herbaceous angiosperms.Leaf size variation has been most commonly interpreted in terms of biomechanical constraints(e.g.affected by plant size limitations)or in terms of direct adaptation associated with leaf size effects in optimizing important physiological functions of individual leaves along environmental gradients(e.g.involving temperature and moisture).An additional interpretation is explored here,where adaptation may be more directly associated with the number of leaves produced and where relatively small leaf size then results as a trade-off of high‘leafing intensity’—i.e.number of leaves produced per unit plant body size.Methods The relationships between mean individual leaf mass,number of leaves and plant body size were examined for 127 species of herbaceous angiosperms collected from natural populations in southern Ontario,Canada.Important Findings In all,88%of the variation in mean individual leaf mass across species,spanning four orders of magnitude,is accounted for by a negative isometric(proportional)trade-off relationship with leafing intensity.These results parallel those reported in recent studies of woody species.Because each leaf is normally associated with an axillary bud or meristem,having a high leafing intensity is equivalent to having a greater number of meristems per unit body size—i.e.a larger‘bud bank’.According to the‘leafing intensity premium’hypothesis,because an axillary meristem represents the potential to produce either a new shoot or a reproductive structure,high leafing intensity should confer greater architectural and/or reproductive plasticity(with relatively small leaf size required as a trade-off).This greater plasticity,we suggest,should be especially important for smaller species since they are likely to suffer greater suppression of growth and reproduction from competition within multi-species vegetation.Accord
文摘Background:With the development of assisted reproductive technology(ART)and its increasing success rate in the mainland of China,more attention has been paid to the safety of ART.In this study,we explored the associations between conception by ART and pregnancy/perinatal complications,and neonatal outcomes compared with similar outcomes following spontaneous conception.Methods:This retrospective cohort study of pregnancies over a 3-year period(2013-2015)was performed at Beijing Obstetrics and Gynecology Hospital,Beijing,China.Subjects were divided into two groups:conception by ART(n=2256)or spontaneous conception(n=6768).According to different fertilization modes,the ART group was divided into in vitro fertilization(IVF,n=1873)and intracytoplasmic sperm injection(ICSI,n=383)subgroups.The ART group was also divided into two different embryo transfer methods;fresh embryo transfer(ET,n=1583)and frozen embryo transfer(FET,n=673)subgroups.Pregnancy complications,perinatal complications,and neonatal outcomes of the enrolled subjects were investigated and analyzed by univariate analysis and multivariate logistic regression.Results:After adjustment for maternal age,gravidity,parity,maternal education,smoking,alcohol consumption,and body mass index(BMI),pregnancies conceived by ART were associated with a significantly increased incidence of gestational diabetes mellitus(GDM;OR 1.88,95%CI 1.56-2.27),gestational hypertension(OR 2.18,95%CI 1.83-2.60),and intrahepatic cholestasis of pregnancy(ICP)(OR 2.79,95%CI 2.15-3.64),compared with spontaneous conception.These associations were similar for the singleton group.In the twin group,only the incidence of ICP was significantly higher than in controls.We found that pregnancies conceived by ART were associated with perinatal complications,including placental abruption(OR 2.14,95%CI 1.33-3.45),premature rupture of membranes(PROM;OR 1.24,95%CI 1.06-1.45),postpartum hemorrhage(OR 2.89,95%CI 2.33-3.59)and polyhydramnios(OR 2.01,95%CI 1.29-3.16).The singleton group had a similar result
文摘Aim： To promote the provision of reproductive health services to young people by exploring the attitudes and perceptions of university students in Shanghai, China, toward reproductive health. Methods： From July 2004 to May 2006, 5 243 students from 14 universities in Shanghai took part in our survey. Topics covered the demands of reproductive health-care services, attitudes towards and experience with sex, exposure to pornographic material, and knowledge on sexual health and sexually transmitted infections （STIs）/AIDS. Results： Of the 5 067 students who provided valid answer sheets, 50.05% were female and 49.95% were male, 14.86% were medical students, and 85.14% had non-medical backgrounds. A total of 38.4% of respondents had received reproductive health education previously. The majority of students supported school-based reproductive health education, and also acquired information about sex predominantly from books, schoolmates, and the Internet. Premarital sexual behavior was opposed by 17.7% of survey participants, and 37.5% could identify all the three types of STIs listed in the questionnaire. Although 83.7% knew how HIV is transmitted, only 55.7% knew when to use a condom and 57.8% knew that the use of condoms could reduce the risk of HIV infection. Conclusion： The reproductive health service is lagging behind current attitudes and demands of university students. Although students＇ attitudes towards sexual matters are liberal, their knowledge about reproductive health and STIs/AIDS is still limited. It is therefore necessary to provide effective and confidential reproductive health services to young people.
基金grants from the SciTechnical Development Project of Shaanxi Province, China （2005K15-G2） Traditional Chinese Project of Shaanxi Province, China （2005024） Natural Science Foundation of Xi＇ an Jiaotong University （573026）.
文摘Aim： To investigate the effect of formaldehyde （FA） on testes and the protective effect of vitamin E （VE） against oxidative damage by FA in the testes of adult rats. Methods： Thirty rats were randomly divided into three groups： （1） control; （2） FA treatment group （FAt）; and （3） FAt ＋ VE group. FAt and FAt ＋ VE groups were exposed to FA by inhalation at a concentration of 10 mg/m^3 for 2 weeks. In addition, FAt ＋ VE group were orally administered VE during the 2-week FA treatment. After the treatment, the histopathological and biochemical changes in testes, as well as the quantity and quality of sperm, were observed. Results： The testicular weight, the quantity and quality of sperm, the activities of superoxide dismutase （SOD）, glutathione peroxidase （GSH-Px） and glutathione （GSH） were significantly decreased whereas the level of malondialdehyde （MDA） was significantly increased in testes of rats in FAt group compared with those in the control group. VE treatment restored these parameters in FAt ＋ VE group. In addition, microscopy with hematoxylin-eosin （HE） staining showed that seminiferous tubules atrophied, seminiferous epithelial cells disintegrated and shed in rats in FAt group and VE treatment significantly improved the testicular structure in FAt ＋ VE group. Conclusion： FA destroys the testicular structure and function in adult rats by inducing oxidative stress, and this damage could be partially reversed by VE.
基金supported by National Key R&D Program of China(No.2018YFD0500600)National Natural Science Foundation of the P.R.of China(No.31872364 and No.31802067)the Natural Science Foundation of Guangdong Province(No.2018A030310201)
文摘This study was conducted to investigate the effects of dietary supplementation with yeast culture(YC)and organic selenium(Se)during late gestation and lactation on reproductive performance,milk quality,piglet preweaning performance,antioxidant capacity,and secretion of immunoglobulin in multiparous sows.A total of 160 healthy cross-bred sows(Landrace×Yorkshire,mean parity 4.1±0.3)were randomly assigned to 4 groups as follows:1)high nutrient(HN),3,420 kcal/kg digestible energy(DE)and 18.0%crude protein(CP);2)low nutrient(LN),3,240 kcal/kg DE and 16.0%CP;3)LN+YC,LN diet+10 g/kg YC;4)LN+YC+Se,LN diet+10 g/kg YC+organic Se(1 mg/kg Se).Feeding trials of sows started from d 85 of pregnancy to d 35 of lactation.Compared with sows in the LN group,sows fed the LN+YC+Se diet had greater litter weaning weight,average litter gain,and milk fat content(14-d and25-d milk)(P<0.05).The content of malonaldehyde(MDA)(colostrum and 14-d milk)was lesser,and the activity of glutathione peroxidase(GSH-Px)(colostrum and 25-d milk)was greater when sows were fed the LN+YC+Se diet,compared with sows fed the LN diet(P<0.05).Supplementation of YC and organic Se in the nutrient-restricted diet improved sows’reproductive performance and pig weaning body weight by enhancing the antioxidant capacity and fat content in milk.
文摘Research concerning the psychosocial aspects of infertility and infertility treatment focuses more often on women than men. The aim of this review was to synthesize the English-language evidence related to the psychological and social aspects of infertility in men and discuss the implications of these reports for clinical care and future research. A structured search identified 73 studies that reported data concerning the desire for fatherhood and the psychological and social aspects of diagnosis, assisted reproductive technology （ART） treatment and unsuccessful treatment among men with fertility difficulties. The studies are diverse in conceptualisation, design, setting and data collection, but the findings were reasonably consistent. These studies indicated that fertile and infertile childless men of reproductive age have desires to experience parenthood that are similar to those of their female counterparts; in addition, diagnosis and initiation of treatment are associated with elevated infertility-specific anxiety, and unsuccessful treatment can lead to a state of lasting sadness. However, rates of clinically significant mental health problems among this patient population are no higher than in the general population. Infertile men who are socially isolated, have an avoidant coping style and appraise stressful events as overwhelming, are more vulnerable to severe anxiety than men without these characteristics. Men prefer oral to written treatment information and prefer to receive emotional support from infertility clinicians rather than from mental health professionals, self-help support groups or friends. Nevertheless, structured, facilitated psycho-educational groups that are didactic but permit informal sharing of experiences might be beneficial. There are gaps in knowledge about factors governing seeking, persisting with and deciding to cease treatment; experiences of invasive procedures; parenting after assisted conception; adoption and infertility-related grief and shame among men. Few resource-cons
