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1.
An assessment of fertility in boron-exposed turkish subpopulations   总被引:3,自引:0,他引:3  
Summary In order to assess the effects of boron and its compounds on human health in a country with the world’s largest deposits, investigations were carried out on fertility and reproduction in the most highly exposed populations. The 927 probands, 697 male and 230 female, interviewed in the field were selected from six different areas of Turkey, in the provinces of Balikesir, Eskisehir, and Kutahya, with the highest boron deposits. These people are exposed to boron environmentally or occupationally or both. The drinking waters of high-boron soils contain 0.7–29 mg B/L compared with 0.05-0.45 mg B/L of low-boron soils. By the so-called pedigree technique 5,934 marriages were ascertained over three generations from all study areas. Childless families among 911 probands were 29 in number and 3.17% in frequency with minor variations from one area to the next, and 3.0% averaged over the generations. Infertility rates in a boron-free community near Ankara with 625 families studied over three generations was 4.48%, and in a larger population of 49,856 families randomly investigated by us throughout the country was 3.84%. No significant differences were observed in terms of marital status and childbearing between 222 and 399 occupationally boron-unrelated and boron-related men, respectively. Nor was there any difference with respect to other aspects studied. It was concluded that, within the limitations of this study, there was no evidence that boron interferes with human fertility and reproduction.  相似文献   

2.
In order to rule out the possibility of omitting some individuals in the study at field visits described in previous articles, either because of the reluctance of the subject or because of his appointment elsewhere, fertility and infertility states of borate workers of the Borax and Acid Plants in Bandirma, Balikesir are given. Balikesir is one of the four provinces with large borate deposits of Turkey, and Bandirma is 1 of its 19 districts. This county is relatively far away from borate deposits, and drinking water piped out through the springs has a boron amount between 0.10 and 0.82 ppm B. That the participants are occupationally exposed to the mineral in essence is therefore conceivable. At the first phase of the investigation, 191 workers were interviewed, as detailed previously. Among these, there were six infertiles of the primary type with a rate 3.1%. Boron-unrelated infertile couples among sibs were found to be 2.6–3.6%, and 3.2% for three-generation marriages—none being higher than those revealed in different sets of controls. In the second stage of work, computerized files of all workers of the facility and all employees of the general management sharing the same location were checked without an interview. Twenty-four subjects (3.4%) out of 712 workers were childless versus 2.7% among 108 employees, and 2.2% among 91 workers of a distantly located sulfuric acid plant of the same complex. The differences were not significant, and these recent findings support the conclusion already reached almost unambiguously that boron exposure at the present levels does not interfere with human reproduction.  相似文献   

3.

Infertility is regarded as a global health problem affecting 8–12% of couples. Male factors are regarded as the main cause of infertility in 40% of infertile couples and contribute to this condition in combination with female factors in another 20% of cases. Abnormal sperm parameters such as oligospermia, asthenospermia, and teratozoospermia result in male factor infertility. Several studies have shown the deteriorative impact of heavy metals on sperm parameters and fertility in human subjects or animal models. Other studies have pointed to the role of antioxidants in counteracting the detrimental effects of heavy metals. In the currents study, we summarize the main outcomes of studies that assessed the counteracting impacts of heavy metal and antioxidants on male fertility. Based on the provided data from animal studies, it seems rational to administrate appropriate antioxidants in persons who suffer from abnormal sperm parameters and infertility due to exposure to toxic elements. Yet, further human studies are needed to approve the beneficial effects of these antioxidants.

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4.
Molecular insights into the causes of male infertility   总被引:6,自引:0,他引:6  
Infertility is a reproductive health problem that affects many couples in the human population. About 13–18% of couple suffers from it and approximately one-half of all cases can be traced to either partner. Regardless of whether it is primary or secondary infertility, affected couples suffer from enormous emotional and psychological trauma and it can constitute a major life crisis in the social context. Many cases of idiopathic infertility have a genetic or molecular basis. The knowledge of the molecular genetics of male infertility is developing rapidly, new “spermatogenic genes” are being discovered and molecular diagnostic approaches (DNA chips) established. This will immensely help diagnostic and therapeutic approaches to alleviate human infertility. The present review provides an overview of the causes of human infertility, particularly the molecular basis of male infertility and its implications for clinical practice.  相似文献   

5.
Unexplained infertility affects about one-third of infertile couples and is defined as the failure to identify the cause of infertility despite extensive evaluation of the male and female partners. Therefore, there is a need for a multiparametric approach to study sperm function. Recently, we developed a Fluorescence-Based Ratiometric Analysis of Sperm Centrioles (FRAC) assay to determine sperm centriole quality. Here, we perform a pilot study of sperm from 10 fertile men and 10 men in couples with unexplained infertility, using three centriolar biomarkers measured at three sperm locations from two sperm fractions, representing high and low sperm quality. We found that FRAC can identify men from couples with unexplained infertility as the likely source of infertility. Higher quality fractions from 10 fertile individuals were the reference population. All 180 studied FRAC values in the 10 fertile individuals fell within the reference population range. Eleven of the 180 studied FRAC values in the 10 infertile patients were outliers beyond the 95% confidence intervals (P = 0.0008). Three men with unexplained infertility had outlier FRAC values in their higher quality sperm fraction, while four had outlier FRAC values in their lower quality sperm fraction (3/10 and 4/10, P = 0.060 and P = 0.025, respectively), suggesting that these four individuals are infertile due, in part, to centriolar defects. We propose that a larger scale study should be performed to determine the ability of FRAC to identify male factor infertility and its potential contribution to sperm multiparametric analysis.  相似文献   

6.
A genetic study of Hirschsprung disease   总被引:27,自引:5,他引:22       下载免费PDF全文
Hirschsprung disease, or congenital aganglionic megacolon, is commonly assumed to be a sex-modified multifactorial trait. To test this hypothesis, complex segregation analysis was performed on data on 487 probands and their families. Demographic information on probands and the recurrence risk to relatives of probands are presented. An increased sex ratio (3.9 male:female) and an elevated risk to sibs (4%), as compared with the population incidence (0.02%), are observed, with the sex ratio decreasing and the recurrence risk to sibs increasing as the aganglionosis becomes more extensive. Down syndrome was found at an increased frequency among affected individuals but not among their unaffected sibs, and the increase was not associated with maternal age. Complex segregation analysis was performed on these family data. The families were classified into separate categories by extent of aganglionosis. For cases with aganglionosis beyond the sigmoid colon, the mode of inheritance is compatible with a dominant gene with incomplete penetrance, while for cases with aganglionosis extending no farther than the sigmoid colon, the inheritance pattern is equally likely to be either multifactorial or due to a recessive gene with very low penetrance. A model of gene action with random effects during morphogenesis is compatible with our observations.  相似文献   

7.
1 Correspondence address. E-mail: akandewole{at}yahoo.com Infertility in developing countries is pervasive and a seriousconcern. In addition to the personal grief and suffering itcauses, the inability to have children especially in poor communitiescan create broader problems, particularly for the woman. Infertilityservices in developing countries span the spectrum from preventionto treatment. From a societal and public health standpoint,prevention is cost–effective and is considered by manygovernments and public health care providers to be a priorityfor service delivery. While prevention remains paramount, takenalone it ignores the plight of infertile couples, includingthose with non-infectious causes of infertility. Two key argumentsare frequently used to challenge the development of new reproductivetechnologies in developing countries: overpopulation and limitedresources. Evidence supports the conclusion that there is acompelling need for infertility treatment beyond prevention.In many instances, assisted reproductive technologies (ART)are the last hope or the only means to achieve a child for couples.In an effort to make much needed ART to developing countriesaccessible and affordable, developing countries should lookto public–private partnerships. Governments have a responsibilityto ensure safe and effective services including the controlof standards for clinical procedures and the regulation of professionalpractice.  相似文献   

8.
Genetic differences among the three species of Sphyraena with two gill rakers from East Asia (S. iburiensis, S. obtusata, and S. pinguis, defined recently as the S. obtusata group), were investigated using 799-bp sequences of the mitochondrial cytochrome b gene. Pairwise sequence differences within each of the three species were 0.0–0.4% (S. iburiensis), 0.0–0.4% (S. obtusata), and 0.0–0.6% (S. pinguis), respectively, pairwise sequence differences among the three species being 18.3–18.6% (S. iburiensis vs. S. obtusata), 14.9–15.4% (S. iburiensis vs. S. pinguis), and 17.6–18.3% (S. obtusata vs. S. pinguis), respectively. The extent of the latter were comparable to those among four other congeneric species, S. africana, S. forsteri, S. helleri, and S. japonica (16.0–24.5%). Phylogenetic analysis using the maximum-likelihood method indicated reciprocal monophyly of the three species, each clade being supported by a bootstrap value of 100%. These findings fully supported the taxonomic status of these species, recently elucidated by detailed morphological comparisons. In addition, the S. obtusata group formed a strongly supported clade against the four other congeneric species.  相似文献   

9.
The present study was carried out in order to assess the genetic component in a group of sterile or infertile couples from a latin american population. During a six-year-period, 258 patients were investigated. Sixty two per cent of the cases were studied for sterility and 38% for infertility. It was found that 34% had genetic pathology. In infertile couples the frequency of chromosome abnormalities was 2.8%; when sterility was also considered this frequency was 11.6%. Chromosome variants were found in 11.4% of the sterile patients and in 8.8% of the infertile cases.  相似文献   

10.
Approximately 48.2% of couples of 15 to 49 years of age practice family planning methods in India. Female sterilization accounts for 34.2%, with male sterilization declining from 3·4% in 1992–93 to 1·9% in 1998–99. Use of the condom increased to 3·1% from 2·4%. There is an urgent need for research to develop new contraceptive modalities especially for men and also for women and to make existing methods more safe, affordable and acceptable. Current efforts in India to develop a male contraceptive are mainly directed towards (i) development of antispermatogenic agents to suppress sperm production, (ii) prevention of sperm maturation, (iii) prevention of sperm transport through vas deferens or rendering these sperm infertile and (iv) prevention of sperm deposition. Research work in the field of prevention of sperm transport through vas deferens has made significant advances. Styrene maleic anhydride (SMA) disturbed the electrical charge of spermatozoa leading to acrosome rupture and consequent loss in fertilizing ability of sperm. A multicentre phase-III clinical trial using SMA is continuing and it is hoped that the SMA approach would be available in the near future as an indigenously developed injectable intra-vasal male contraceptive. The safety and efficacy of available oral contraceptives were evaluated. An indigenously developed oral contraceptive ‘Centchorman’, which is a nonsteroidal, weakly estrogenic but potently antiestrogenic, was found to be safe and effective and is now being marketed in India since 1991 as a ‘once a week’ pill. Cyclofem and Mesigyna have been recommended as injectable contraceptives with proper counselling and service delivery by Indian studies. It has been recommended that these injectable contraceptives be added to the existing range of contraceptive methods available in the National Family Planning Programme. Based on the Indian studies CuT 200 was also recommended. Studies have indicated the advantage of intrauterine devices (IUD); they are long acting, relatively easily removed and fertility returns rapidly after their removal. Recent studies have recommended CuT 200 for use up to 5 years. The combination of some plant products i.e.Embelia ribes, Borax andPiper longum has been found to be safe and effective as a female contraceptive and the results of phase-I clinical trials are encouraging. Research work is going on in the country in various areas with special reference to hormonal contraceptive — a three monthly injectable contraceptive, immuno-contraceptives, antiprogestins, etc.  相似文献   

11.
 We investigated population-based vital records of the seventeenth and eighteenth century French Canadian population to assess the effects of marriage season on the outcome of the first births under natural fertility conditions (n=21,698 marriages). Promptness of the first successful conception after marriage differed according to marriage season; the proportion of marriages with a marriage-first birth interval of 8.0–10.0 months was lowest (34%) for marriages in August–October (P=0.001). Although the male/female sex ratio of the babies born with an interval of 8.0–10.0 months was generally higher (1.10) than those with an interval of 10.0–24.0 months (1.05), the marriages in August–October resulted in a significantly reduced sex ratio (0.96) among only the prompt conceptions (P=0.026). We discuss whether this seasonal reduction of the sex ratio could be partly explained by a clustered pregnancy loss of male zygotes in early pregnancy. Received: 5 January 1998 / Accepted: 9 September 1998  相似文献   

12.
OBJECTIVE--To evaluate guidelines for general practice management and referral of infertile couples. Guidelines were implemented with a disease specific reminder at the time of consultation (the guidelines were embedded within a structured infertility management sheet for each couple). DESIGN--Pragmatic randomised controlled trial. Participating practices were randomised to a group that received the guidelines and a control group. SETTING--82 general practices in Grampian region. SUBJECTS--100 couples referred by general practitioners receiving the guideline and 100 couples referred by control general practitioners. MAIN OUTCOME MEASURES--Whether the general practitioner had taken a full sexual history and examined and investigated both partners appropriately. RESULTS--Characteristics of patients referred by study and control general practitioners did not differ significantly at baseline. Compliance with the guidelines increased for all targeted activities. General practitioners in the study group were more likely to take a sexual history (for example, couples'' use of fertile period, 85% v 69%, p < 0.01); examine both partners (female partner, 68% v 52%, p < 0.05; male partner 39% v 13%, p < 0.01); and investigate both partners (day 21 progesterone, 72% v 41%, p < 0.001; semen analysis, 51% v 41%, p > 0.05). Improvements were greater when general practitioners used the disease specific reminder. CONCLUSION--Receiving guidelines led to improvements in the process of care of infertile couples within general practice. This effect was enhanced when the guidelines were embedded in a structured infertility management sheet for each couple.  相似文献   

13.
Chromosomal anomalies may be a reason for both male and female infertility. The aim of this study was to investigate the contribution of chromosomal abnormalities in sterile couples from Kuwait. A total of 118 patients with clinical diagnosis of infertility was analyzed using cytogenetic banding techniques. Common chromosomal abnormalities were detected in 12 patients. We describe here one new case of an infertile male with the karyotype 46,XY, del(21)(pter;q11.2). The overall incidence of 11% abnormality indicates that routine chromosome analysis of infertile couples in Kuwait should be considered before the planning of intracytoplasmic sperm injection.  相似文献   

14.
The aim of this study was to screen infertile men for HFE H63D mutation in correlation with clinical characteristics of infertile men (sperm concentration, sperm motility, morphology, testicular volume, Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH) and total Testosterone levels) and find out if the HFE H63D mutation has an effect on male infertility. After excluding hormonal treatment, any scrotal pathology, having any systemic diseases such as diabetes mellitus, sickle cell anemia and microdeletions of the Y chromosome, a total of 148 infertile men with age range between 17 and 52-years-old (average age 29.6 ± 7.2) were enrolled into the study. Our analysis indicates that the mean FSH levels are significantly higher (6.3 ± 4.6 mIU/ml, P = 0.03), whereas sperm motility is significantly lower (36.6 ± 28.1%, P = 0.01) in the infertile men with the HFE H63D mutation compared with subjects lacking this mutation. Comparison of allele frequencies of the infertile men with Ts < 50% versus the infertile men with Ts > 50% revealed a significant difference as expected (P = 0.001, OR = 0.14, %95 CI = 0.04–0.44). Comparison of allele frequencies of infertile men with abnormal sperm motility versus infertile men with normal sperm motility revealed a highly significant difference (P = 0.005, OR = 3.11, %95 CI = 1.41–6.86). Thus, the HFE H63D mutation seems to be an important risk factor for impaired sperm motility and is clinically associated with male infertility.  相似文献   

15.
California sea lions, Zalophus californianus, were trained to elicit maximum voluntary breath holds during stationary underwater targeting, submerged swimming, and trained diving. Lowest heart rate during rest periods was 57 bpm. The heart rate profiles in all three protocols were dominated by a bradycardia of 20–50 bpm, and demonstrated that otariid diving heart rates were at or below resting heart rate. Venous blood samples were collected after submerged swimming periods of 1–3 min. Plasma lactate began to increase only after 2.3-min submersions. This rise in lactate and our inability to train sea lions to dive or swim submerged for periods longer than 3 min lead us to conclude that an aerobic limit had been reached. Due to the similarity of heart rate responses and swimming velocities recorded during submerged swimming and trained diving, this 2.3-min limit should approximate the aerobic dive limit in these 40-kg sea lions. Total body O2 stores, based on measurements of blood and muscle O2 stores in these animals, and prior lung O2 store analyses, were 37–43 ml O2 kg−1. The aerobic dive limit, calculated with these O2 stores and prior measurements of at-sea metabolic rates of sea lions, is 1.8–2 min, similar to that measured by the change in post-submersion lactate concentration. Accepted: 7 July 1996  相似文献   

16.
The effect of a 3-week exercise programme on performance and economy of walking was analysed in 16 male patients with chronic heart failure [mean age 51.8 (SD 6.9) years, height 174.9 (SD 6.3) cm, body mass 75.3 (SD 11.5) kg, ejection fraction 20.8 (SD 5.0)%]. They were submitted to a cardiopulmonary exercise test on a cycle ergometer and a 6-min walking test on a treadmill before and after the period of exercise training. The training programme consisted of interval cycle (five times a week for 15 min), and treadmill ergometer training (three times a week for 10 min) at approximately 70% cycling peak oxygen uptake (O2peak) and supplementary exercises (three times a week for 20 min). Compared to the pre values cycling O2peak [11.9 (SD 2.9) vs 14.0 (SD 2.3) ml ·  kg–1 · min–1], maximal self paced walking speed [0.68 (SD 0.33) vs 1.16 (SD 0.30) m · s–1], and net walking power [2.16 (SD 0.89) vs 2.73 (SD 0.91) W · kg–1] had increased (P < 0.01) while net energy cost [3.31 (SD 0.66) vs 2.33 (SD 0.38) J · kg–1 ·  m–1] had decreased (P < 0.001) after the training period. Approximately 42% of the increase of walking speed resulted from a higher walking power output, whereas approximately 58% corresponded to a positive effect on walking economy. The improvement in walking economy was a function of an increase in walking velocity itself and a result of a more efficient walking technique. These results would indicate that in patients with marked exercise intolerance, adequate exercise training programmes could contribute to favourable metabolic changes with positive effects on the economy of motion. Accepted: 29 August 1996  相似文献   

17.
Human Y chromosome is used as a tool in male infertility and population genetic studies. The aims of this research were to analyse the prevalence of Y chromosome microdeletions among infertile Latvian men, and to identify possible lineages of Y chromosome that may be at increased risk of developing infertility. A study encompassed 105 infertile men with different spermatogenic disturbances. Deletions on Y chromosome were detected in 5 out of 105 (∼5%) cases analysed in this study. Three of them carried deletion in AZFc region and two individuals had AZFa+b+c deletion. Study of Y chromosome haplogroups showed that N3a1 and R1a1 lineages were found less frequently in the infertile male group compared to ethnic Latvian group, however K* cluster was predominantly found in infertile male Y chromosomes. Conclusions: (1) Our study advocates running Y chromosome microdeletion analyses only in cases of severe form of infertility; (2) Ychromosome haplogroup analysis showed statistically significant tendencies that some haplogroups are more common in ethnic male group, but others are more common in infertile males.  相似文献   

18.
The chromosomal anomalies, microdeletions of AZF region of Y-chromosome and CFTR gene mutations have been studied among 80 infertile men with idiopathic spermatogenetic failure: 36 (45%) patients with aspermia, 19 (24%) patients with azoospermia and 25 (31%) patients with severe oligoasthenoteratozoospermia. In total 30% males with spermatogenetic failure genetic factor of infertility was observed. Karyotype anomalies were observed in 17.5% of infertile men, within 16.2% numerical and structural gonosomal anomalies and in 1.3%—Robertsonian translocation were revealed. In 11.25% males with spermatogenetic failure, Y-chromosome AZF region microdeletions were detected. The frequency of CFTR major mutation F508del among infertile men was 6.25%. 5T allele of polymorphic locus IVS8polyT was detected in 7.5% of examined men. The results obtained indicate the high complexity of cytogenetic and moleculargenetic studies of male infertility.  相似文献   

19.
Summary Development of asparagus microspores in cold-treated buds of varying sizes and shed microspores from these buds in in vitro culture were observed cytologically for the G459 genotype. Before cold pretreatment, more than 75% of the microspores in flower buds of the 1.4–1.6, 1.7–1.9, 2.0–2.2, 2.3–2.5, and 2.6–2.8 mm size classes were at the early-, mid-, late-uninucleate, early-, and late-binucleate stages, respectively. After 7 d in cold treatment, percentages of microspores at different stages changed in all flower buds. Most notable was the appearance of binucleate microspores resulting from symmetric rather than asymmetric division. For flower buds of 1.7–1.9, 2.0–2.2, and 2.3–2.5 mm size classes, 4.9%, 27.2%, and 11.4% of the microspores had divided symmetrically, respectively. When microspores from buds of each size category were cultured in androgenesis induction medium, only microspores completing symmetric pollen mitosis I during cold treatment were observed to divide further, and calluses were only obtained from microspores of flower bud size classes where symmetric divisions were observed after several days of cold treatment. Significant correlations existed among microspore callus yield, the percentage of late-uninucleate microspores in vivo before cold treatment, and the frequency of symmetric pollen mitosis I after 7 d of cold treatment. Consequently, asparagus microspore androgenesis may occur through one developmental pathway, where a symmetric first mitotic division is a prerequisite for continued development.  相似文献   

20.
This article argues that the rapid transfer of assisted conception technologies, such as in vitro fertilization, to India is not restricted merely to the modalities of offering potential biomedical resolution of infertility but includes, more crucially, how clinicians and infertile consumers assimilate the “Western technoscience” of conception. The article draws on a larger multisite ethnographic study of infertility and assisted conception in India’s five major cities and is principally based on narratives of clinicians and infertile couples and on clinic-based ethnographic observations. In this article I contend that the success or failure of assisted conception, when situated in the universe of Hindu faith, becomes a powerful critique of the “incompleteness” of the “Western” science of conception. Situating this contention in the broader context of a clinician’s faith, I assert that assisted conception—by conjoining seemingly disparate domains of the traditional and the modern, the sacred and the profane, the human and the superhuman, science and religion—produces clinical theodicies that help explain and contain the tentativeness permeating the conception technologies. The article concludes by arguing that this enchanted version of a thoroughly disenchanted worldview of biomedicine is part of a larger cultural process of indigenization of biomedicine in India.  相似文献   

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