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PubMed2002

Cortical involvement in temporal reproduction: evidence for differential roles of the hemispheres.

Only few studies have addressed temporal processing for durations longer than 1 s, and even fewer studies have investigated cortical involvement in time perception, in particular temporal production and reproduction. The present study investigated temporal reproduction in healthy control subjects and patients with anterior or posterior cortical lesions in the left or right hemisphere, or with subcortical left-hemispheric lesions. The paradigm involved presentation of either auditory or visual stimuli of 10 different standard intervals ranging from 1 to 5.5 seconds duration. Participants were required to reproduce the duration of a stimulus. Our results show that: (1) temporal reproduction across this temporal range can be better described with two separate linear regressions (bilinear approach) than with one single linear regression, thus contrasting the scalar timing concept; (2) that patients can, regardless of the hemisphere lesioned, perform reproductions of durations smaller than 2-3 s with reasonable accuracy; and (3) that patients with right-hemispheric lesions appear to be impaired in reproductions of stimuli longer than 2-3 s. Since attention appeared not to be impaired in the patients tested, the findings suggest that the integrity of the right hemisphere seems to be critical for temporal reproduction of intervals longer than 2-3 s.

Adult↗

PubMed1999

Control of reproductive and energetic status by environmental cues in a desert rodent, Shaw's jird.

The photoperiod is the controller of reproductive cycles in temperate climates for most mammalian species. Several nonphotoperiodic cues appear to control reproductive status at lower latitudes. We tested the roles of the photoperiod or water availability on the reproductive status of the desert-dwelling Shaw's jird (Meriones shawi) trapped from a moderately temperate climate (approximately 30 degrees N in Egypt). Males and females were transported to the laboratory and, in Experiment 1, were housed in either the longest (LDs) or shortest (SDs) photoperiod that occurs naturally at this latitude (14 h light, 10 h dark, and 10 h light, 14 h dark, respectively). In Experiment 2, LD-housed male jirds were subjected to a water availability schedule that inhibits reproductive status in a closely related species (Meriones unguiculatus). Specifically, one group had no free water, but had lettuce available once a week for 24 h (control jirds received free water for 10-60 min/day). Neither photoperiod nor free-water deprivation affected reproductive status of male or female jirds. That is, neither testes mass nor spermatogenetic activity (males), nor uterine mass nor folliculogenesis (females) were affected by either condition. In addition, photoperiod did not affect body or white adipose tissue (WAT) masses, although SDs decreased carcass lipid in males. Free-water deprivation decreased body and WAT pad masses, and all carcass components. Collectively, these results suggest that changes in day length or water availability alone do not affect reproductive status in Shaw's jird.

Adaptation, Physiological↗

PubMedDate not supplied

Men in Australia Telephone Survey (MATeS): a national survey of the reproductive health and concerns of middle-aged and older Australian men.

BACKGROUND: The Men in Australia Telephone Survey (MATeS) describes the prevalence of self-reported reproductive health disorders as well as related concerns and health behaviours among middle-aged and older Australian men. METHODS: A representative sample population (n=5990) of Australian men (>or=40 years) was obtained by contacting a random selection of households with unbiased sampling, stratified by age and state. A 20-min computer-assisted telephone interview was done to assess reproductive health and related knowledge and beliefs, sociodemographic factors, general health, and lifestyle factors. FINDINGS: A response rate of 78% (5990/7636) was achieved. 34% (1627/4737) of men surveyed reported one or more reproductive health disorder, all of which were most common in the oldest age group. Age-standardised prevalence of significant lower urinary tract symptoms was 16%, erectile dysfunction was 21%, and prostate disease was 14%. About 50% of participants reported having had a prostate cancer test whereas only 30% (300/1012) of men with erectile dysfunction sought medical help. Willingness to seek medical help for erectile dysfunction was related to age and ethnic origin. Although men aged 40-69 years expressed a moderate or high level of concern about prostate cancer and loss of erectile function, concern about reproductive health was less in the oldest age group (>or=70 years). INTERPRETATION: The high prevalence of reproductive health disorders and associated concerns in middle-aged and older Australian men draws attention to the need to develop appropriate services and education strategies specifically directed to improving reproductive health in these men.

Adult↗

PubMed1999

Angiotensin II: a reproductive hormone too?

It has long been known that angiotensin II (Ang II) can affect reproductive tissues such as the uterus. However, the existence of a local renin-angiotensin system (RAS) in female as well as male reproductive tissues is a relatively recent observation. Of great interest is the discovery that all components of the RAS are present in the ovary, that the ovary secretes components of the RAS into the bloodstream, and that the ovary itself is responsive to Ang II. Recent studies suggest that the primary role of Ang II in the ovary is to cause atresia in non-ovulatory follicles; however, there is also compelling data to suggest that Ang II facilitates ovulation. Male reproductive structures also contain all of the components of the RAS, gonadotropins regulate the activity of these components, and these tissues have Ang II receptors. Of great interest is the expression of testis-specific angiotensin-converting enzyme (ACE), which is located on germ cells. Recent studies using gene knock-out techniques indicate that testis ACE plays an important role in male fertility. However, the overall significance of the RAS for normal reproductive function remains questionable. There is now a body of evidence implicating the RAS in pathophysiologies associated with reproductive function, which gives rise to the possibility that drugs acting on the RAS might ameliorate some of these disorders. Considerable work remains to determine the role of Ang II in reproductive functions.

Angiotensin II↗

PubMed1996

Growth, phenology and reproduction of an arid-environment winter ephemeral Dimorphotheca pluvialis in response to combined increases in CO2 and UV-B radiation.

The winter ephemeral Dimorphotheca pluvialis was grown in open-top chambers in ambient or elevated CO2 (350 or 650 micromol mol(-1)), combined with ambient (2.39 to 7.59 kJ m(-2) d(-1)) or increased (4.94 to 11.13 kJ m(-2) d(-1)) UV-B radiation. Net CO2 assimilation rate and leaf water use efficiency increased in elevated CO2, but increased UV-B did not affect gas exchange. Leaf biomass was greater under increased UV-B, but vegetative biomass was unaffected in elevated CO2. Initiation of reproduction was delayed, and proportional investment in reproductive biomass at harvest was reduced in elevated CO2. Increased UV-B stimulated reproduction, particularly in ambient CO2, but also in elevated CO2 at a later stage. Changes in reproductive phenology and prolonged development in elevated CO2 during the stressful late season could indirectly be detrimental to reproductive success of D. pluvialis, but stimulation of reproduction by enhanced UV-B may to some extent mitigate this.

Journal Article↗

PubMed1997

Effects of a randomized health education intervention on aspects of reproductive health knowledge and reported behaviour among adolescents in Zimbabwe.

Unwanted teenage pregnancy and the attendant morbidity and mortality necessitate an understanding of the factors influencing adolescent sexuality and the implementation of programmes designed to improve their knowledge and reproductive behaviour. A randomized controlled study on reproductive health knowledge and behaviour was undertaken among adolescent pupils drawn from a multi-stage random cluster sample. A self-administered questionnaire was used to assess aspects of reproductive health knowledge and behaviour at baseline followed by a health education intervention, except for control schools. Results are based on 1689 responses made up of 1159 intervention and 530 control respondents. There was a significant increase in correct knowledge about aspects of menstruation in intervention as compared with control schools [odds ratio (OR) = 4.5, 95% confidence interval (CI) = 3.4-6.1). Significantly, (OR = 2.0, 95%CI = 1.1-3.9) more pupils from intervention than control schools scored correctly on practice relating to menstruation. Pupils from intervention schools were more likely (P < 0.001) to know that a boy experiencing wet dreams could make a girl pregnant and that a girl could get pregnant at her first sexual intercourse (OR = 1.4, 95%CI = 1.1-1.9). Knowledge of family planning was low in both groups at baseline but was high at five months follow-up in the intervention schools. The findings point to the need for early school-based reproductive health education programmes, incorporating correct information on reproductive biology and the subsequent prevention of reproductive ill health.

Adolescent↗

PubMed1998

Outcomes and effectiveness in reproductive health.

Measuring reproductive health is problematic. Awareness of the problems needs to be raised both among those collecting and those using data on reproductive health. This paper discusses two major measurement questions--one related to ascertainment and the other to attribution. The first question is to what extent the observed levels and patterns of reproductive health outcomes in women are valid as opposed to artefacts of the data sources and the data collection methods? The second question is can lack of evidence of effectiveness for any reproductive health intervention ever confidently be separated into no effects vs an inability to measure effects? Determining the effectiveness of health interventions is notoriously difficult. Reproductive health may not be a case for special pleading in the competition for scarce resources, but equally it should not be a case for special standards of proof of the effectiveness of interventions--standards which have not indeed been met by many other, and yet unquestioned, health care priorities. "What works" in reproductive health should in fact be judged from at least four different perspectives: from that of women and their families, health professionals, the scientific community, and national and international policy-makers.

Data Collection↗

PubMed2000

Influence of a natural stressor (predator odor) on locomotor activity in the meadow vole (Microtus pennsylvanicus): modulation by sex, reproductive condition and gonadal hormones.

Sex differences in a variety of non-reproductive behaviors have been indicated to occur in seasonally breeding polygynous promiscuous rodents such as the meadow vole, Microtus pennsylvanicus. The present study was designed to assess the effects of reproductive and hormonal status on the locomotor responses of meadow voles following brief exposure to the odors of a natural predator, the Red fox (Vulpes vulpes). Adult male and female meadow voles, which are seasonal photoperiodically-induced breeders, were housed in either mixed sex pairs under a long, reproductively stimulatory photoperiod (simulating breeding: long light cycle, paired: LLC + P) or in same-sex pairs under a short, reproductively inhibitory photoperiod (simulated non-breeding: short light cycle, non-paired: SLC-NP). On 2 consecutive days following 1 day of baseline activity monitoring, voles were exposed individually for 3 min to fox odor and a novel pungent control odor (extract of almond). The levels of various measures of activity that were displayed by the voles were assessed by an automated Digiscan activity monitoring system. LLC + P (simulated breeding) voles displayed higher basal levels of activity relative to SLC + NP (simulated non-breeding) voles, with males displaying greater activity than females. LLC + P (simulated breeding) males displayed a significant reduction in activity levels following exposure to fox odor relative to control odor. The reductions in activity following fox odor exposure were related to plasma testosterone levels such that a larger behavioral response (i.e. greater reduction) was associated with higher levels of testosterone. Furthermore, dividing males into high and low testosterone groups based on the median levels of testosterone revealed that high but not low testosterone males displayed reductions in activity following exposure to fox odor relative to control odor. No changes in activity levels following exposure to fox odor were noted in SLC-NP males, and either SLC-NP or LLC + P females. These results show that this sexually dimorphic non-reproductive behavior is significantly influenced by reproductive condition and gonadal hormone levels.

Animals↗

PubMed2001

Adult female prairie voles and meadow voles do not suppress reproduction in their daughters.

Reproductive suppression of young females by conspecific females has been reported from laboratory studies on several species of rodents, including the prairie vole, Microtus ochrogaster, but not meadow voles, M. pennsylvanicus. We exposed female prairie voles and meadow voles to two treatments: a mother and one 23-26-day-old daughter paired with a strange male and a 23-26-day-old daughter paired with a different strange male. We found no differences in the proportion of daughters breeding or the time to sexual maturation for daughters raised in the two treatments for either species. Thus, we have no indication that mothers had any adverse effect on reproductive efforts of their daughters. These results differ from previous studies that concluded young female prairie voles were reproductively suppressed by female relatives. The difference between our and previous studies on reproductive suppression is that we examined breeding in young females rather than proximate measures of growth and reproductive development. We question the evolutionary significance of reproductive suppression among related female microtine rodents, especially in that it has not been documented from field populations.

Journal Article↗

PubMed2000

Absence of structural or functional alterations in male and female reproductive organs of F1 and F2 generations derived from female mice exposed to 3'-azido-3'-deoxythymidine during pregnancy.

To investigate the effects of in utero exposure to 3'-azido-3'-deoxythymidine (AZT) on male and female reproductive system development, pregnant CD-1 mice were given daily intragastric doses of 25.0 mg AZT during days 12 through 18 of gestation. The offspring were examined at birth, as well as at pubertal, young adult and adult stages of development, for reproductive organ endpoints including anogenital distance, onset of testicular descent, latency to vaginal opening, and proportion of time for each of the stages of estrous cycle. These reproductive endpoints remained mostly unchanged in AZT-treated offspring as compared to the controls. Males and females exposed in utero to AZT (F1 generation) were fertile when mated to untreated females and males, respectively, and their liveborn F2 offspring showed no adverse effects for any of the reproductive parameters tested. Thus, no evidence of developmental reproductive toxicity was noted either in the F1 mice exposed to AZT during the critical period of male and female reproductive system development, or in the F2 mice born of matings between the AZT-exposed F1 mice and unexposed animals.

Abnormalities, Drug-Induced↗

PubMed2001

Images of the body and the reproductive system among men and women living in Shantytowns in Porto Alegre, Brazil.

This paper presents the results of anthropological research on graphic and verbal images of the reproductive system carried out among 99 women and 103 men living in four shantytowns in Porto Alegre, Brazil. Interviewers were instructed to ask for the drawings in the course of interviews lasting 12-20 hours. Some 55 drawings of the female reproductive system by men and 99 by women were produced and are analysed here together with information from the interviews and observational data. The majority of the men's drawings of women's reproductive system tended to include 'external' body parts only, in contrast with the 'hidden' nature of the internal body parts, which were commonly depicted by the women. Women have been more exposed to the health system than men and the majority made basic biomedical types of drawings. However, their verbal representations were sometimes informed by other notions and values and their physical experience of their bodies. Lack of contact with the health system does not fully account for the men's apparent lack of knowledge about the reproductive body. Rather, biomedical knowledge was simply not a point of reference for the men's understandings of the body. The majority of drawings made by men of the female reproductive body portrayed the primacy of sexuality in their view of the reproductive system.

Adolescent↗

PubMed2003

Physiology, diagnosis, and diseases of the avian reproductive tract.

Disorders of the reproductive system represent a large portion of both large and small domestic animal medicine. Although some disorders of this system have been extensively studied in birds, this science is still in its infancy, when compared to mammalian reproductive medicine. This may be due to several reasons, but the simple fact that birds are oviparous renders knowledge of mammalian reproductive anatomy, histology, physiology, and disease process, inapplicable to avian patients. Nevertheless, several specific diseases or conditions affecting the reproductive system of birds have been described. By integrating information about the comparative anatomy and physiology of birds, reports of the most common reproductive diseases of birds and utilizing the latest diagnostic techniques, especially videoendoscopy, the avian practitioner should be able to diagnose and properly treat a high percentage of the avian reproductive diseases.

Animals↗

PubMed1998

The long-term dynamics of tuberculosis and other diseases with long serial intervals: implications of and for changing reproduction numbers.

The net and basic reproduction numbers are among the most widely-applied concepts in infectious disease epidemiology. A net reproduction number (the average number of secondary infectious cases resulting from each case in a given population) of above 1 is conventionally associated with an increase in incidence; the basic reproduction number (defined analogously for a 'totally susceptible' population) provides a standard measure of the 'transmission potential' of an infection. Using a model of the epidemiology of tuberculosis in England and Wales since 1900, we demonstrate that these measures are difficult to apply if disease can follow reinfection, and that they lose their conventional interpretations if important epidemiological parameters, such as the rate of contact between individuals, change over the time interval between successive cases in a chain of transmission (the serial interval). The net reproduction number for tuberculosis in England and Wales appears to have been approximately 1 from 1900 until 1950, despite concurrent declines in morbidity and mortality rates, and it declined rapidly in the second half of this century. The basic reproduction number declined from about 3 in 1900, reached 2 by 1950, and first fell below 1 in about 1960. Reductions in effective contact between individuals over this period, measured in terms of the average number of individuals to whom each case could transmit the infection, meant that the conventional basic reproduction number measure (which does not consider subsequent changes in epidemiological parameters) for a given year failed to reflect the 'actual transmission potential' of the infection. This latter property is better described by a variant of the conventional measure which takes secular trends in contact into account. These results are relevant for the interpretation of trends in any infectious disease for which epidemiological parameters change over time periods comparable to the infectious period, incubation period or serial interval.

Adolescent↗

PubMed2001

Consanguinity and advanced maternal age as risk factors for reproductive losses in Alexandria, Egypt.

BACKGROUND: Consanguinity has been a long-standing social habit among Egyptians. Estimates of consanguinity ratios in different parts of Egypt ranged from 29 to 50%. This study aimed at delineating the role of consanguinity and advanced maternal age on reproductive losses in Alexandria, Egypt. METHODS: A case-control study, on 730 couples with history of reproductive losses and 2,081 normal couples, was done during the period October, 1998 until August, 2000. RESULTS: Of the 730 couples with reproductive losses, consanguinity frequency was 68.8% with 56.2% first cousins. Prenatal loss and infant deaths were highly encountered among consanguineous marriages (p < 0.0001). In a multivariate logistic regression analysis, consanguinity between couples increased the relative risk of repeated abortion (OR: 3.95; 95% CI: 3.04-5.14), stillbirths (OR: 10.6; 95% CI: 6.7-17.0), neonatal death (OR: 17.2; 95% CI: 10.8-27.3), post-neonatal death (OR: 14.5; 95% CI: 10.6-19.9) and total reproductive losses (OR: 8.3; 95% CI: 6.9-10.1). A positive association was found between advanced maternal age and repeated abortion (OR: 3.19; 95% CI: 2.04-4.97) as well as total reproductive losses (OR: 2.37; 95% CI: 1.74-3.2). CONCLUSION: This study, the largest-reported case-control study on reproductive losses in Alexandria, strongly suggests that consanguinity may play a major role in the high rates of prenatal and infant mortality while advanced maternal age has a significant role in the causation of repeated abortion, and they must be taken into account for genetic counseling in Egypt. Because of the possibility of controlling, the study gives clear indications for prevention.

Adult↗

PubMed2026

The importance of integrating genetic testing into reproductive medicine: a retrospective observational study investigating the monogenic causes of human infertility in couples considering ICSI.

The genetic landscape of human infertility is complex with diverse etiologies. Identifying the underlying etiology is crucial for guiding reproductive decisions and improving management for infertile couples. Here, we aim to report on the molecular spectrum of monogenic genetic causes of reproductive failure. Over a 3-year period, we recruited all infertile couples considering assisted reproductive technologies (ART) for whom the underlying genetic cause had been identified, in either partner, using exome sequencing (ES). Clinical data of all participants along with their hormonal profiles, sonographic findings and spermograms were recorded. The study included 50 couples with primary infertility. Clinically, male factor infertility was documented in 26 patients, female factor infertility in 10, while reproductive failure was unexplained in the remaining 14 couples. All participating couples had potentially disease-causing variants in infertility genes. ES identified variants related to male infertility in 26 men, while variants in female infertility-related genes were detected in the remaining couples (n = 24). According to ACMG classification criteria, 78% (39/50) of couples harbored pathogenic/likely pathogenic (P/LP) variants, whereas 22% (11/50) carried variants of uncertain significance (VUS). In view of the identified genetic etiologies, the cohort was stratified into two groups based on the predicted reproductive outcome: (1) couples with significantly impaired reproductive potential, and (2) couples who can have biological children using appropriate medical interventions. However, classifications involving VUS were interpreted cautiously and considered exploratory. This study provides further evidence for the molecular heterogeneity of human infertility and highlights the usefulness of genetic testing for infertile couples pursuing ARTs.

Humans↗

PubMed2002

Lymphocytes and T lymphocyte subsets are regionally distributed in the female goat reproductive tract: influence of the stage of the oestrous cycle.

The reproductive tract of the female is a part of the mucosal system which protects from pathogens invasion. We have analysed the presence and distribution of total lymphocytes, plasma cells (antibody secreting B cells) and T lymphocytes subsets in the reproductive tract of the female goat. The influence of the oestrous cycle on the densities of lymphocytes and plasma cells of the cervix and uterus horn was evaluated in sections prepared for conventional histology. Immunocytochemistry was used for the study of lymphocyte subsets by confocal microscopy and immunoperoxidase techniques. Present results show that the reproductive tract of the goat is a site rich in lymphocytes. These cells were found mingled with the epithelial cells of the endometrium and distributed throughout the stroma. Lymphocyte aggregates were observed in the stroma. Lymphocyte but not plasma cell number changed depending on the reproductive stage of the goats. The impact of the hormonal environment was different for the cervix and uterine horn. Immunocytochemistry studies evidenced the presence of cells displaying immunoreactivity for both CD 4+ and CD 8+ antibodies in the epithelial layer and stroma of the cervix and uterine horn. These cells were more numerous in the cervix and were also found infiltrating the luminal epithelia of endometrial glands. Overall, our results indicate that lymphocyte distribution is different in the cervix and the horn, and is influenced by the stage of the reproductive cycle. In summary, CD 4+ and CD 8+ T lymphocytes subsets could be found in the endometrium of both the cervix and uterine horn of the goat reproductive tract.

Animals↗

PubMed2006

Mating-responsive genes in reproductive tissues of female Drosophila melanogaster.

Male-derived accessory gland proteins that are transferred to females during mating have profound effects on female reproductive physiology including increased ovulation, mating inhibition, and effects on sperm utilization and storage. The extreme rates of evolution seen in accessory gland proteins may be driven by sperm competition and sexual conflict, processes that may ultimately drive complex interactions between female- and male-derived molecules and sperm. However, little is known of how gene expression in female reproductive tissues changes in response to the presence of male molecules and sperm. To characterize this response, we conducted parallel genomic and proteomic analyses of gene expression in the reproductive tract of 3-day-old unmated and mated female Drosophila melanogaster. Using DNA microarrays, we identified 539 transcripts that are differentially expressed in unmated vs. mated females and revealed a striking peak in differential expression at 6 h postmating and a marked shift from primarily down-regulated to primarily up-regulated transcripts within 3 h after mating. Combining two-dimensional gel electrophoresis and liquid chromatography mass spectrometry analyses, we identified 84 differentially expressed proteins at 3 h postmating, including proteins that appeared to undergo posttranslational modification. Together, our observations define transcriptional and translational response to mating within the female reproductive tract and suggest a bimodal model of postmating gene expression initially correlated with mating and the final stages of female reproductive tract maturation and later with the declining presence of male reproductive molecules and with sperm maintenance and utilization.

Animals↗

PubMed2000

Reproductive systems and evolution in vascular plants.

Differences in the frequency with which offspring are produced asexually, through self-fertilization and through sexual outcrossing, are a predominant influence on the genetic structure of plant populations. Selfers and asexuals have fewer genotypes within populations than outcrossers with similar allele frequencies, and more genetic diversity in selfers and asexuals is a result of differences among populations than in sexual outcrossers. As a result of reduced levels of diversity, selfers and asexuals may be less able to respond adaptively to changing environments, and because genotypes are not mixed across family lineages, their populations may accumulate deleterious mutations more rapidly. Such differences suggest that selfing and asexual lineages may be evolutionarily short-lived and could explain why they often seem to be of recent origin. Nonetheless, the origin and maintenance of different reproductive modes must be linked to individual-level properties of survival and reproduction. Sexual outcrossers suffer from a cost of outcrossing that arises because they do not contribute to selfed or asexual progeny, whereas selfers and asexuals may contribute to outcrossed progeny. Selfing and asexual reproduction also may allow reproduction when circumstances reduce opportunities for a union of gametes produced by different individuals, a phenomenon known as reproductive assurance. Both the cost of outcrossing and reproductive assurance lead to an over-representation of selfers and asexuals in newly formed progeny, and unless sexual outcrossers are more likely to survive and reproduce, they eventually will be displaced from populations in which a selfing or asexual variant arises.

Journal Article↗