bluuebunny/crossref_metadata_2025 huggingface dataset:
Dual sampling for the detection of female Chlamydia trachomatis infection with a polymerase chain reaction test
Authors: Watson P G , Wilson B H
Published: March 2004

Using a polymerase chain reaction method of detection, the value of taking urethral and endocervical specimens to screen for female Chlamydia trachomatis infection and to test for cure of that infection was audited. In the population of 130 women being screened, 19 (14.6%) had a positive result in either or both specimens. Eighteen infections (94.7%) were detected on the urethral sample and 16 (84.2%) on the endocervical sample. In the population of 40 women being tested for cure, C. trachomatis was detected in nine. The urethral sample was positive in 9/9 (100%) and the endocervical sample in 7/9 (77.8%). Analysis of those nine cases showed that seven had failed to take their treatment properly or had been at risk of re-infection.
Management of sexually acquired reactive arthritis in 19 North Thames GUM clinics
Authors: Bell Charlotte , Brook Gary , Jones Karen , Carlin Elizabeth , Daniels David , Forster Greta , Miller Robert ,   on behalf of the North Thames GUM/HIV Audit Group
Published: March 2004

Our objective was to describe how genitourinary medicine (GUM) clinics in the North Thames region manage sexually acquired reactive arthritis (SARA), and to compare management with national guidelines. A self-completed questionnaire survey and retrospective case note review was conducted between September and October 2001. Clinicians in 33 clinics were asked to describe their clinic's policy on the management of SARA, and to review the last five cases seen or the last cases seen in the preceding two years, if less than five.

Nineteen (58%) clinics took part. There were inter-clinic variations in the investigation and management of patients, with only 63% (12/19) of clinics offering non-steroidal anti-inflammatory drugs (NSAIDs) and 58% (11/19) giving doxycycline 1001mg. twice daily for two weeks for urethritis - the rest using any of three other antibiotic regimens. There was no consistent policy of referral between other specialties and GUM for genital screening and partner notification. A total of 36 male and female case notes were reviewed. Patients without arthritis or joint swelling (5/38, 13%), or with non-typical symptoms such as diarrhoea (5/38, 13%) were diagnosed inappropriately with SARA.

Only 33 (87%) had evidence of a sexually transmitted infection (STI) with at least two (5%) of patients being treated with antibiotics despite no apparent indication being present. Only 21 (55%) had documented NSAID therapy. Case identification was difficult due to the lack of a national disease code (KC60) for SARA.

The data suggest that a diagnosis of SARA is sometimes being made with no identifiable STI, or where symptoms are more suggestive that another route of infection is likely. A clear guideline within clinics to standardize prescribing of antibiotics is needed and collaborative policies with GUM are needed for other specialties to use when investigating and managing patients with seronegative arthritis. GUM should consider re-introducing a KC60 code for SARA for better case identification.
A case of condyloma acuminata with giant and multiple lesions on the vulva and breast: successfully treated with surgical operations
Authors: Zhao Liang , Fang Fang , Carey Fiona , Wang Qian-Qiu
Published: March 2004

We report a case of a 24-year-old female patient with a history of giant and multiple lesions of condylomata acuminata on the vulva and breasts which were treated by surgical excision.
Extensive genital warts associated with HTLV-I infection
Authors: Radja Neelam , Lau Richard
Published: March 2004

This is the first report of infection with HTLV-I associated with severe condylomatosis. Assessment of atypical or extensive genital warts should include testing for this retroviral infection.
The antecedents of identification: A rhetorical analysis of British Muslim activists' constructions of community and identity
Authors: Hopkins Nick , Kahani‐Hopkins Vered
Published: March 2004

This paper takes as its focus the perception of community. This is analysed through reference to the literature concerning the adoption of more inclusive, superordinate social categories. Whilst most research tends to focus on the consequences of these social categories for self and other perception, we focus on their antecedents. These are typically hypothesized to include such issues as the perception of the subordinate groups' common fate and factors affecting their perceptual differentiation (e.g. their similarity and entitativity). However, rather than conceiving of such issues as pre‐given antecedent variables, we explore how these issues (and others) are actively constructed in and through discourse. More specifically, we explore how such issues are sites of contestation as activists with different political projects seek to construct quite different versions of the relevant superordinate community identity. Our data are qualitative and are drawn from contemporary debates amongst British Muslims concerning their relations with non‐Muslim Britons and non‐British Muslims across the globe. A key issue in these deliberations concerns the nature of British Muslims' identity and the superordinate identifications that best facilitate its expression and realization. We suggest that constructions of common fate, similarity, entitativity etc., far from being ‘givens’, are the means through which different definitions of Muslim identity are constructed and different forms of collective action mobilized.
Social identity, self‐evaluation and in‐group bias: The relative importance of particular domains of self‐esteem to the in‐group
Authors: Hunter John A. , Kypri Kypros , Stokell Natalie M. , Boyes Mike , O'Brien Kerry S. , McMenamin Kathleen E.
Published: March 2004

This investigation sought to assess the link between in‐group bias and domain‐specific self‐esteem. Two experiments were carried out. Experiment 1 revealed that social category members (i.e. Christians), manifested an increase in that domain of self‐esteem judged to be relatively more important to the in‐group (i.e. physical self‐esteem), following the display of in‐group bias. A second experiment which sought to examine an alternative explanation for these findings, in terms of enhanced social identity salience, produced identical findings. Domains of self‐esteem relatively less important to the in‐group (i.e. mathematical self‐esteem) were unaffected in each experiment. Consistent with recent revisions to the second corollary of the self‐esteem hypothesis, Experiment 2 further revealed that category members with low public collective self‐esteem (who believed that Christians were evaluated negatively by Atheists) showed more pronounced in‐group bias.
Women's collective constructions of embodied practices through memory work: Cartesian dualism in memories of sweating and pain
Authors: Gillies Val , Harden Angela , Johnson Katherine , Reavey Paula , Strange Vicki , Willig Carla
Published: March 2004

The research presented in this paper uses memory work as a method to explore six women's collective constructions of two embodied practices, sweating and pain. The paper identifies limitations in the ways in which social constructionist research has theorized the relationship between discourse and materiality, and it proposes an approach to the study of embodiment which enjoins, rather than bridges, the discursive and the non‐discursive. The paper presents an analysis of 25 memories of sweating and pain which suggests that Cartesian dualism is central to the women's accounts of their experiences. However, such dualism does not operate as a stable organizing principle. Rather, it offers two strategies for the performance of a split between mind and body. The paper traces the ways in which dualism can be both functional and restrictive, and explores the tensions between these two forms. The paper concludes by identifiying opportunities and limitations associated with memory work as a method for studying embodiment.
Surfing the money tides: Understanding the foreign exchange market through metaphors
Authors: Oberlechner Thomas , Slunecko Thomas , Kronberger Nicole
Published: March 2004

This study describes metaphorical conceptualizations of the foreign exchange market held by market participants and examines how these metaphors socially construct the financial market. Findings are based on 55 semi‐structured interviews with senior foreign exchange experts at banks and at financial news providers in Europe. We analysed interview transcripts by metaphor analysis, a method based on cognitive linguistics. Results indicate that market participants' understanding of financial markets revolves around seven metaphors, namely the market as a bazaar, as a machine, as gambling, as sports, as war, as a living being and as an ocean. Each of these metaphors highlights and conceals certain aspects of the foreign exchange market and entails a different set of implications on crucial market dimensions, such as the role of other market participants and market predictability. A correspondence analysis supports our assumption that metaphorical thinking corresponds with implicit assumptions about market predictability. A comparison of deliberately generated and implicitly used metaphors reveals notable differences. In particular, implicit metaphors are predominantly organic rather than mechanical. In contrast to academic models, interactive and organic metaphors, and not the machine metaphor, dominate the market accounts of participants.
The psychometric properties of the short version of the Cybernetic Coping Scale: A multigroup confirmatory factor analysis across four samples
Authors: Guppy Andrew , Edwards Julian A. , Brough Paula , Peters‐Bean Kyron M. , Sale Craig , Short Emma
Published: March 2004

Throughout the literature, there appears to be little support for the psychometric characteristics of scales measuring coping behaviour. This article explores the psychometric properties of the 20‐item version of the Cybernetic Coping Scale (CCS; Edwards & Baglioni, 1993). Initially, confirmatory factor analysis and internal reliability analysis were conducted on large samples of data from four different studies in order to conduct an exhaustive examination of the scale. Results provided moderate support for the 20‐item version of the CCS. However, improved model modification produced moderate to strong support for a 15‐item version. Multigroup confirmatory factor analysis was then conducted on the 15‐item version of the CCS in order to cross‐validate the measurement model across groups. Findings revealed a wellfitting model with a stable factor structure and partial measurement invariance. Both versions produced acceptable to high internal reliability. Findings indicate support for the use of the 15‐item version of the CCS and suggest that this short version of the CCS is the best fitting model of all the other previously developed CCS scales.
Impact of variable risk preferences on the effectiveness of control by pay
Authors: Deckop John R. , Merriman Kimberly K. , Blau Gary
Published: March 2004

Pay for performance is an organizational control mechanism intended to align the interests of employer and employee. We investigated whether employee risk preference interferes with the effects of this ‘control by pay’ on attitudinal and behavioural outcomes. We found that the degree of consistency between risk preference and control by pay affected withdrawal intentions, contingent pay satisfaction and organizational citizenship behaviour, as hypothesized. The results suggest that the use of pay for performance as a control mechanism should take into account employee risk preference, and that this concern should apply broadly in the organization, not just at the executive level.
The congruence problem in John Holland's theory of vocational decisions
Authors: Arnold John
Published: March 2004

John Holland's theory of vocational choice has been a dominant one in careers psychology for many years, especially in North America. A key construct in the theory is congruence between person and environment. Yet research has failed to find as strong a link as might be expected between congruence and outcomes such as satisfaction and performance. This could present a major challenge to the theory. Fourteen possible reasons for the weak associations between congruence and outcome measures are identified and discussed under three broad headings: the theory, the research and the world. It is concluded that the most important reasons are (1) that Holland's measures of people and environments partially neglect some important constructs; (2) that environments have not been conceptualized or measured entirely appropriately; and (3) the data that are used in the calculation of congruence indices are insufficiently precise or comprehensive. It is suggested that Holland's theory and associated measures should be developed further, and that the processual elements of it need more attention.
Is there an FSH-releasing factor?
Authors: Padmanabhan V , McNeilly AS
Published: March 2004

A thorough understanding of the factors that regulate the secretion of FSH is critical for the development of efficient methods for fertility regulation. The purpose of this review is to evaluate what is currently known about the existence of FSH-releasing factor(s). It considers the obstacles encountered in understanding the control of FSH secretion, current knowledge of the nature of FSH secretion and the mechanisms involved in controlling FSH secretion, the arguments that have been posed against the need for an FSH-releasing factor and finally the evidence available to date supporting the existence of FSH-releasing factor(s).
DNA repair mechanisms and gametogenesis
Authors: Baarends WM , van der Laan R , Grootegoed JA
Published: March 2004

In mammals, there is a complex and intriguing relationship between DNA repair and gametogenesis. DNA repair mechanisms are involved not only in the repair of different types of DNA damage in developing germline cells, but also take part in the meiotic recombination process. Furthermore, the DNA repair mechanisms should tolerate mutations occurring during gametogenesis, to a limited extent. In the present review, several gametogenic aspects of DNA mismatch repair, homologous recombination repair and postreplication repair are discussed. In addition, the role of DNA damage-induced cell cycle checkpoint control is considered briefly. It appears that many genes encoding proteins that take part in DNA repair mechanisms show enhanced or specialized expression during mammalian gametogenesis, and several gene knockout mouse models show male or female infertility. On the basis of such knowledge and models, future experiments may provide more information about the precise relationship between DNA repair, chromatin dynamics, and genomic stability versus instability during gametogenesis.
Induction of final maturation by sperm penetration in canine oocytes
Authors: Saint-Dizier M , Renard JP , Chastant-Maillard S
Published: March 2004

In contrast to oocytes of most mammals, the canine oocyte is at the germinal vesicle stage at ovulation. Moreover, the bitch is receptive to mating while immature oocytes are present in the oviducts. The aims of this study were to examine the influence of fertilization in immature oocytes on the resumption of meiosis, and the modification of both male and female chromatin in fertilized oocytes. Canine cumulus-oocyte complexes collected from routine ovariectomies were cultured in medium 199 with 20% fetal calf serum for 24 h, incubated in the same medium with fresh semen for 24 h, washed, cultured for a further 24 h and fixed. Control oocytes were cultured in the same medium but without spermatozoa for 24, 48 or 72 h. After fixation, chromatin was stained with propidium iodide and examined using laser scanning confocal microscopy. The data indicate that sperm penetration can occur in immature canine oocytes and that it induces resumption of meiosis. After 72 h of culture, the percentage of oocytes at the germinal vesicle stage was significantly lower in fertilized oocytes (40% versus 60.3% for control oocytes; P < 0.05) and the percentage of oocytes beyond metaphase I was significantly greater in fertilized oocytes (28.3% metaphase I and II, and two pronuclei versus 10.2% metaphase I and II for control oocytes; P < 0.01). Observation and measurement of the area of chromatin in fertilized oocytes showed an overall parallel condensation-decondensation of both female and male chromatin from the germinal vesicle stage to the pronuclear stage.
Development of cultured bovine embryos after exposure to high temperatures in the physiological range
Authors: Rivera RM , Hansen PJ
Published: March 2004

Embryonic development is inhibited by exposure of cultured embryos to high temperatures. However, culture temperatures used to demonstrate the effects of heat on development have been higher than the body temperatures experienced typically by heat-stressed cows. The aim of this study was to determine whether exposing bovine oocytes and embryos to temperatures characteristic of body temperatures of heat-stressed cows would affect embryonic development in vitro. The CO2 percentage of the gas phase was adjusted in all experiments to prevent pH changes in the medium caused by decreased solubility of CO2 at high temperatures. Fertilization of oocytes at 41.0 degrees C reduced cleavage rate and the percentage of oocytes that became blastocysts compared with at 38.5 degrees C. There was no deleterious effect of fertilization at 40.0 degrees C. When putative zygotes and two-cell embryos were exposed to a range of temperatures from 38.5 to 41.0 degrees C for 3, 6, 9 or 12 h, heat shock reduced the number that developed to the blastocyst stage but only after exposure to 41.0 degrees C for 9 or 12 h. In addition, it was tested whether low O2 tension would reduce the detrimental effects of heat shock. The deleterious effect of 41.0 degrees C was not dependent upon oxygen content or the gas mixture used for culture (5% versus 20.95% O2), indicating that the deleterious effects of heat shock did not depend upon a high O2 environment. In the final experiment, embryos were exposed to 24 h fluctuations in temperature designed to mimic the rectal temperatures of cows exposed to heat stress. Exposure of embryos to this pattern of temperatures starting after fertilization reduced development when embryos were exposed to this environment for 8 days but not when embryos were exposed for 1 day only. These findings indicate that embryonic development can be disrupted by a short-term severe or a prolonged mild heat shock and that the effects of heat shock are not artefacts of changes in pH or high oxygen tension.
Effect of gonadotrophins on the ovarian interstitial tissue of the wood mouse, Apodemus sylvaticus
Authors: Clarke J , Brook F
Published: March 2004

The ovarian interstitial tissue of the wood mouse (Apodemus sylvaticus) is extensively developed. The effect of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) on ovarian interstitial tissue was investigated in wood mice from a laboratory stock. The tissue was assessed by measuring the relative size of the cells, cell nucleus diameter and (in adults) nuclear shape. Hormone-treated wood mice had larger interstitial cells and larger cell nuclei than untreated animals. In addition, the cell nuclei of adult hormone-treated wood mice had a smooth round or oval outline, whereas those of untreated animals had an irregular outline with spiky projections. Electron microscopy showed that the irregular spiky outline of the cell nuclei in untreated wood mice was caused by distortions of the nuclear membrane by a large number of intracellular lipid droplets; the droplets were less abundant in the hormone-treated animals. These experiments indicate that the cells of the interstitial tissue of the wood mouse are under the control of gonadotrophins, and that these cells are likely to be a site of the synthesis and release of steroid hormones. The methods used in this study to assess the state of the cells could be applied to animals from the field to investigate the role of interstitial tissue in the reproductive biology of wood mice.
Effect of a single dose of ibuprofen lysinate before embryo transfer on pregnancy rates in cows
Authors: Elli M , Gaffuri B , Frigerio A , Zanardelli M , Covini D , Candiani M , Vignali M
Published: March 2004

Embryo implantation is a critical step in both cows and humans. The use of ibuprofen lysinate to enhance implantation has been investigated in cattle with the specific aim of improving pregnancy rates after embryo transfer. In this study, heifers (n = 100) were assigned randomly to one of two groups: one group was treated i.m. with 5 mg ibuprofen lysinate kg(-1) body weight 1 h before embryo transfer and a control group received vehicle only. A single embryo was transferred into each recipient cow. There was a significant difference in the number of pregnancies after embryo transfer between cows in the treated (41 of 50; 82%) and control (28 of 50; 56%) groups (P < 0.05). These data indicate that ibuprofen lysinate may be an effective adjunctive treatment for assisted reproduction in cattle. Further studies are needed to clarify whether this effect is associated with the reduction of cyclooxygenase enzyme isoforms during embryo transfer or whether other mechanisms are involved.
Effects of genistein on the periovulatory expression of messenger ribonucleic acid for matrix metalloproteinases and tissue inhibitors of metalloproteinases in the rat ovary
Authors: Komar CM , Matousek M , Mitsube K , Mikuni M , Brannstrom M , Curry TE
Published: March 2004

The matrix metalloproteinases (MMPs) play critical roles in the ovulatory process. Their expression and activity, together with those of the endogenous tissue inhibitors of metalloproteinases (TIMPs), are stimulated by LH. The LH surge initiates a cascade of events resulting in ovulation and formation of the corpus luteum via activation of protein kinases A and C, as well as tyrosine kinases. In vitro perfused rat ovaries were untreated, or treated with LH (0.2 microg ml(-1)) plus 0.2 mmol 3-isobutyl-1-methylxanthine l(-1) with 0, 10 or 100 micromol genistein l(-1) (an inhibitor of tyrosine kinases) to assess whether tyrosine kinases are mediators of the LH-stimulated increase in ovarian expression of the MMPs and TIMPs. After 10 h of perfusion, ovaries were collected and frozen until RNA isolation. Northern and RNase protection analyses were used to measure mRNA encoding collagenase 3, gelatinases A and B, and TIMPs-1, -2 and -3. Treatment with LH plus 3-isobutyl-1-methylxanthine resulted in a two- and fivefold increase in mRNA encoding collagenase 3 and TIMP-1, respectively (P < 0.05). Treatment with 100 micromol genistein l(-1) blocked the LH-stimulated increase in collagenase 3 (0.012 +/- 0.002 versus 0.028 +/- 0.005 relative units for 100 micromol genistein l(-1) versus LH; P < 0.05), whereas neither dose of genistein affected LH-induced TIMP-1 expression. LH alone or with genistein did not alter the expression of mRNA encoding TIMP-2 and TIMP-3, or mRNA encoding gelatinases A and B. These data indicate that tyrosine kinases play a role in the LH-induced tissue remodelling required for ovulation by mediating the LH-stimulated expression of collagenase 3.
Characterization of northern pintail (Anas acuta) ejaculate and the effect of sperm preservation on fertility
Authors: Penfold LM , Harnal V , Lynch W , Bird D , Derrickson SR , Wildt DE
Published: March 2004

Northern pintail duck semen and sperm traits were characterized, and the fertility of cold-stored spermatozoa was investigated using artificial insemination. Excellent quality ejaculates containing high proportions of motile spermatozoa were collected from drakes within 20 s by a massage technique. Semen was collected in Beltsville poultry semen extender, pooled and cold-stored (4 degrees C) for 0, 24, 48 or 72 h. Hens were inseminated with 100 microl twice a week, and eggs were assessed for fertilization and hatch success. Fertilization success was similar (P > 0.05) for semen cold-stored for 0 (51.6%), 24 (51.5%), 48 (41.1%) and 72 h (22.3%; P > 0.05). Similar (P > 0.05) percentages of fertilized eggs hatched to live offspring (73.1, 71.4, 87.0 and 80.0%, respectively). Fresh semen was also equilibrated with 1 or 4% dimethylsulphoxide or glycerol, and cryopreserved at the following rates: (1) approximately 60 degrees C min(-1) (in liquid nitrogen [LN(2)] vapour) for 10 min; (2) 1 degrees C min(-1) to -20 degrees C, LN(2) vapour for 10 min; and (3) 1 degrees C min(-1) to -35 degrees C, all followed by immersion in LN(2). After thawing for 30 s at 37 degrees C or 20 min at 4 degrees C, sperm motility and viability were assessed. The highest numbers of motile spermatozoa were recovered after slow-fast freezing (2) and thawing at 0 degrees C (P < 0.05), but survival was inadequate to allow artificial insemination. Nonetheless, cold storage provides an effective means of short-term storage with no loss of fertility in this waterfowl species.
Ovarian steroid hormone production in a multiple ovulating male line and a single ovulating traditional line of turkeys
Authors: Buchanan S , Robertson GW , Hocking PM
Published: March 2004

Ovarian production of oestradiol and progesterone was investigated in a single ovulating traditional line and a multiple ovulating male line of turkeys. The oestradiol output from small follicles in response to LH stimulation and the aromatase activity of the residual ovary were also compared. The multiple hierarchy of follicles in the male line was shown to consist of a series of follicles of a similar size and stage of physiological maturation. The follicles of the traditional line produced significantly greater quantities of oestradiol than those of the male line. Impaired oestradiol production may have resulted in the lower plasma oestradiol concentration observed in the male line. There was no difference in follicular progesterone output between the traditional-line and male-line turkeys. The oestradiol output of whole small white follicles in response to LH stimulation was similar in the two lines and the depressed steroidogenesis of the male line was not changed. The aromatase activity of the small follicles was also lower in the male line, and there was no evidence that the male line ovary produced oestradiol in quantities proportional to its size. The results demonstrated that the hierarchy of follicles in the male line consisted of groups of follicles of similar mass and hormone output and indicated that selection for increased meat yield may have resulted in reduced ovarian steroidogenesis in male-line turkeys, in comparison with traditional, unselected turkeys.
Leucocyte proliferation in the bovine corpus luteum
Authors: Bauer M , Reibiger I , Spanel-Borowski K
Published: March 2004

Leucocytes vary in type and number during the lifespan of a corpus luteum. The aim of this study was to determine whether there is an increase in the number of lymphocytes and macrophages as a result of local proliferation. Bovine corpora lutea were classified into stages of development, secretion and regression. A new double immunolabelling method was established for nuclear Ki-67 antigen (a marker for cell proliferation) and for leucocyte surface antigens (detection of CD2-, CD3-, CD4-, CD8-positive lymphocytes and CD14-positive monocytes). Differential cell counting was performed. Between the stages of development and regression there was an increase in the number of T-lymphocytes and macrophages. The percentage of proliferating leucocytes in relation to the total number of proliferating cells was approximately 20% at the stage of advanced secretion and 70% at late regression. The increase in the number of proliferating leucocytes at late regression was due to CD14-positive macrophages. These macrophages migrated from small blood vessels into the septa of corpora lutea at the early stage of regression. Macrophages showed local proliferation in the late stage of regression when capillaries were no longer present. It is concluded that the physiological involution of the corpus luteum is an inflammatory-like condition, which includes local proliferation of monocytes.
Effects of feeding tuna oil on the lipid composition of pig spermatozoa and in vitro characteristics of semen
Authors: Rooke JA , Shao CC , Speake BK
Published: March 2004

The aim of the present study was to characterize the effects of feeding tuna oil on the lipid and fatty acid composition of boar spermatozoa and to relate changes in composition to boar semen characteristics. Ten boars were paired by age and allocated to one of two diets (five boars per diet). The diets, which were offered for 6 weeks, consisted of a basal diet that was either unsupplemented or supplemented with 30 g tuna oil kg(-1) diet. Adding tuna oil to the diet increased the ether extract concentration of the diets fed from 65 to 92 g kg(-1) dry matter and supplied 10.5 g long chain polyunsaturated (n-3) fatty acids per 100 g total fatty acids. There were no changes in semen fatty acid composition after 3 weeks of feeding tuna oil. However, after 5 and 6 weeks, the proportions (g per 100 g total fatty acids) of 22:6(n-3) in sperm phospholipid fatty acids were increased from 34.5 to 42.9 g by feeding tuna oil and 22:5(n-6) decreased from 29.8 to 17.9 g. No changes were observed in other sperm lipids or seminal plasma phospholipids as a result of the diets fed. Feeding tuna oil increased the proportion of spermatozoa with progressive motility and with a normal acrosome score and reduced the proportion of spermatozoa with abnormal morphologies.
Effects of bilateral ganglionectomy and melatonin replacement on seasonal rhythm of testicular activity in Zembra Island wild rabbits (Oryctolagus cuniculus)
Authors: Ben Saad MM , Maurel D
Published: March 2004

This study examined the effects of subcutaneous melatonin implants on testicular activity (testis volume and plasma testosterone) in wild rabbits (Oryctolagus cuniculus) captured on Zembra Island (North Tunisia) and maintained in natural temperature and photoperiod conditions. The period of testicular activity was 2 months longer in intact animals with melatonin implants than in intact animals without melatonin implants. After bilateral superior cervical ganglionectomy, testicular activity was inhibited and no spontaneous recrudescence in gonadal function was observed during the 13 months of the experiment, demonstrating the absence of an endogenous circannual rhythm of reproductive function in this species. Renewed testicular activity was observed 2 months after the insertion of melatonin implants in ganglionectomized animals. These results confirm that testicular activity is stimulated by short days in late autumn and that melatonin reactivates the reproductive axis in this species. This finding is in contrast to that in continental populations of wild rabbits in which reproduction is inhibited by short days or melatonin. These results are discussed in terms of insularity and may reflect the geographical isolation of this population.
Maternal-conceptus signalling during early pregnancy in mares: oestrogen and insulin-like growth factor I
Authors: Walters KW , Roser JF , Anderson GB
Published: March 2004

Embryonic production of oestrogen is thought to play an important role in conceptus-maternal signalling during early pregnancy in mares, and may be regulated in an autocrine or paracrine fashion by insulin-like growth factor I (IGF-I). In this study, the hypothesis that IGF-I stimulates embryonic oestrogen synthesis, which in turn stimulates uterine IGF-I secretion was tested. Specific sources of IGF-I in the uterine lumen were characterized. Preimplantation embryos, uterine biopsies, and uterine flush fluids were collected on day 13 of pregnancy. Embryos were cultured whole for 24 h, or dispersed and incubated in serum-free culture medium supplemented with androstenedione or testosterone (0-10 microg ml(-1)) and IGF-I (0-100 microg ml(-1)). Oestrogen synthesis was increased by addition of androgen, but there was no dose-dependent effect of IGF-I. Endometrial explants were cultured for 24, 48 and 72 h in serum-free medium supplemented with oestradiol. IGF-I was measured by radioimmunoassay in embryo-conditioned medium, explant culture medium, blastocoelic fluid, concentrated (x 100) uterine flush fluid and endometrial-tissue homogenate. Both the embryo and endometrium produced significant quantities of IGF-I, indicating a role for this growth factor in autocrine-paracrine signalling during early pregnancy. However, secretion of IGF-I by endometrial explants was not modulated by oestrogen.
Proliferation and differentiation of spermatogonial stem cells
Authors: de Rooij DG
Published: March 2004

Spermatogonial stem cells (A(s) spermatogonia) are single cells that either renew themselves or produce A(pr) (paired) spermatogonia predestined to differentiate. In turn, the A(pr) divide into chains of A(al) (aligned) spermatogonia that also divide. The ratio between self-renewal and differentiation of the stem cells is regulated by glial cell line-derived neurotrophic factor produced by Sertoli cells, while the receptors are expressed in stem cells. A(s), A(pr) and A(al) spermatogonia proliferate during part of the epithelial cycle forming many A(al) spermatogonia. During epithelial stage VIII, almost all A(al) spermatogonia, few A(pr) and very few A(s) spermatogonia differentiate into A1 spermatogonia. A number of molecules are involved in this differentiation step including the stem cell factor-c-kit system, the Dazl RNA binding protein, cyclin D(2) and retinoic acid. There is no fine regulation of the density of spermatogonial stem cells and consequently, in some areas, many A1 and, in other areas, few A1 spermatogonia are formed. An equal density of spermatocytes is then obtained by the apoptosis of A2, A3 or A4 spermatogonia to remove the surplus cells. The Bcl-2 family members Bax and Bcl-x(L) are involved in this density regulation. Several mechanisms are available to cope with major or minor shortages in germ cell production. After severe cell loss, stem cell renewal is preferred above differentiation and the period of proliferation of A(s), A(pr) and A(al) spermatogonia is extended. Minor shortages are dealt with, at least in part, by less apoptosis among A2-A4 spermatogonia.
Regulation and manipulation of angiogenesis in the primate corpus luteum
Authors: Fraser HM , Lunn SF
Published: March 2004

Intense physiological angiogenesis occurs during the early stages of luteal development, providing a model in which the complex processes regulating the angiogenic pathway may be studied. Here, a working hypothesis is presented to explain the diverse changes in the vasculature of the corpus luteum that occur over a short period, based around changes in vascular endothelial growth factor, the angiopoietins and matrix metalloproteinases. An illustration is given of how angiogenesis can be monitored in a primate model and how the role of individual angiogenic factors such as vascular endothelial growth factor may be explored in vivo. Because of the marked effect of inhibition of angiogenesis on luteal function, it is predicted that the normal processes of follicular development, ovulation and luteal function could all be profoundly influenced by the manipulation of angiogenesis.
Pituitary tumours
Authors: Davis  , Farrell WE , Clayton RN
Published: March 2004

Pituitary tumours are a common type of intracranial neoplasm and, depending on the cell type of origin, have diverse endocrine and reproductive effects. The developmental biology of the different cell types is understood to result from a sequential activation of a cascade of transcription factors, and mutations in these factors result in various forms of hypopituitarism. Tumours in the pituitary gland arise from activation of dominantly acting oncogenes such as gsp, or from loss of function of a series of tumour suppressor genes such as MEN1. Abnormal patterns of DNA methylation may be implicated in the allelic losses that cause tumour suppressor gene silencing. The different clinically recognized types of pituitary tumour are currently treated by medical therapies such as dopamine and somatostatin agonists, surgery or radiotherapy. However, these treatments are not entirely satisfactory and recent advances in gene therapy may offer valuable new therapeutic opportunities for patients with aggressive tumours that fail to respond to traditional approaches.
In vitro maturation, fertilization and embryo development after ultrarapid freezing of immature human oocytes
Authors: Wu J , Zhang L , Wang X
Published: March 2004

The purpose of this study was to determine the rates of maturation, fertilization and embryo development of ultrarapidly frozen immature oocytes (immature cumulus-oocyte complexes; COCs) obtained from antral follicles in ovaries of patients with chocolate ovarian cysts. The COCs were cryopreserved by a vitrification method using 5.5 mol ethylene glycol l (-1) plus 1.0 mol sucrose l (-1) in Dulbecco's PBS (DPBS). The survival, maturation and fertilization rates, and the percentage of embryos developing to the two-cell stage were 59, 64, 70 and 71%, respectively. No significant differences were noted in the rates of maturation, fertilization and embryo development between control and cryopreserved oocytes. Two embryos that developed from cryopreserved oocytes of the oocyte donor programme were selected for transfer into the uterus of a recipient with premature ovarian failure, after the recipient had received steroid replacement. A biochemical pregnancy occurred in the recipient after embryo transfer. These results indicate that immature oocytes can survive after cryopreservation and subsequently can be cultured to mature oocytes that are capable of undergoing fertilization in vitro and developing into embryos.
Nitric oxide synthases in pregnant rat uterus
Authors: Farina M , Ribeiro ML , Franchi A
Published: March 2004

The conversion of [14C]arginine into [14C]citrulline as an indicator of nitric oxide synthesis was studied in uteri isolated from rats on different days of gestation, after labour and during dioestrus. Nitric oxide synthesis was present in uterine tissues isolated at each stage of gestation and also in tissues collected during dioestrus and after labour. Expression of neuronal nitric oxide synthase was not detectable at any of the stages studied. Endothelial nitric oxide synthase was present at all the stages studied, but there was a significant increase on day 13 of gestation and a decrease thereafter, with the lowest expression recorded on the day after labour. Inducible nitric oxide synthase expression in rat uteri increased substantially during pregnancy, with the highest expression on day 13 of gestation; expression decreased at term and after labour. The changes in expression of inducible nitric oxide synthase were coincident with the changes in nitric oxide synthase activity in uteri treated with aminoguanidine. Thus, these findings indicate that an increase in expression of inducible nitric oxide synthase in the uterus may be important for maintenance of uterine quiescence during pregnancy and its decrease near the time of labour could have an effect on the start of uterine contractility.
Effect of finadyne on oestradiol-induced ovarian oxytocin and uterine PGF2alpha secretory systems on day 15 after oestrus in ovarian autotransplanted ewes
Authors: Al-Matubsi HY , Fairclough RJ
Published: March 2004

This study was undertaken to determine whether induction of ovarian oxytocin after oestradiol treatment on day 15 after oestrus is mediated through prostaglandin secretion by blocking prostaglandin synthesis using finadyne, an inhibitor of the cyclo-oxygenase pathway. Nine ewes with ovarian autotransplants were assigned randomly to receive an i.m. injection of either oestradiol benzoate (50 microg) in peanut oil ( n= 5) or oestradiol benzoate plus finadyne (2.2 mg kg (-1)) ( n= 4) at 3 h intervals starting at the time of oestradiol injection. Blood samples were collected from the ovarian and contralateral jugular veins at 30 min intervals for 6 h before and at 15 min intervals for up to 9 h after the oestradiol and finadyne injections. The secretion rate of ovarian progesterone remained high in all ewes, thus indicating the presence of a functional corpus luteum. Peripheral oestradiol concentrations were significantly (P < 0.001) higher during the 9 h after oestradiol injection in both groups. None of the oestradiol-finadyne-treated ewes showed significant pulses in either ovarian oxytocin secretion or release of the prostaglandin F(2alpha) metabolite 13,14-dihydro-15-keto PGF(2alpha) (PGFM) after injections. In ewes treated with oestradiol only, at least one detectable pulse of ovarian oxytocin and jugular PGFM was observed with mean +/- SEM amplitude of 17.7 +/- 7.29 ng min (-1) and 237.18 +/- 43.13 pg ml (-1), respectively. The areas under the curve for ovarian oxytocin and jugular PGFM pulses were significantly increased after oestradiol treatment. These findings demonstrate that initiation of the arachidonic acid cascade is important for the secretion of oxytocin after oestrogen treatment.
Seasonal changes in bovine fertility: relation to developmental competence of oocytes, membrane properties and fatty acid composition of follicles
Authors: Zeron Y , Ocheretny A , Kedar O , Borochov A , Sklan D , Arav A
Published: March 2004

Follicle dynamics and oocyte viability in Holstein primiparous and multiparous cows and the relationships between fertility and the biochemical and physical properties of oocyte membranes with season were examined. The conception rates of primiparous (n = 70 885) and multiparous (n = 143 490) cows differed, peaking in the winter and decreasing in the summer. The number of follicles 3-8 mm in diameter per ovary was higher in winter (19.6) compared with summer (12.0). However, in winter the percentage of ovaries with fewer than ten follicles per ovary was 16%, in contrast to 50% in summer. After aspiration of follicles, 7.5 oocytes per ovary were found in winter and 5.0 oocytes per ovary in summer. Cleavage to the two- to four-cell stage after chemical activation was greater in winter than in summer; this was enhanced at the morula stage and embryo development to the blastocyst stage was significantly higher in winter than in summer. Determination of the lipid phase transition in oocyte membranes revealed a shift of 6 degrees C between summer and winter. Fatty acid composition of phospholipids from follicular fluid, granulosa cells and oocytes indicated that there was a higher percentage of saturated fatty acids during the summer and that the percentages of mono-unsaturated and polyunsaturated fatty acids were higher in oocytes and granulosa cells during the winter. Oocytes and granulosa cells had similar fatty acid compositions, in contrast to follicular fluid. These results may explain the differences in the ability of oocytes to develop to the blastocyst stage at different seasons. Thus, temperature changes may lead to changes in membrane properties, which, in turn, can influence oocyte function and fertility.
Expression of mRNA for the LH and FSH receptors in mouse oocytes and preimplantation embryos
Authors: Patsoula E , Loutradis D , Drakakis P , Kallianidis K , Bletsa R , Michalas S
Published: March 2004

The gonadotrophins LH and FSH are known to regulate gonadal growth, and differentiation, endocrine function and gametogenesis. The LH receptor is expressed in ovarian theca, granulosa and luteal cells, and in testicular Leydig cells. The FSH receptor is expressed only in ovarian granulosa cells and in testicular Sertoli cells. The expression of the FSH and LH receptors was analysed by RT-PCR to study the role of these receptors in early mouse development. After reverse transcription, strategically designed nested primers were used for amplification from cDNA. Transcripts for the receptors were present in mouse oocytes and preimplantation embryos. The presence of mRNA for FSH and LH receptors in oocytes, zygotes and preimplantation embryos indicates a potential role for the gonadotrophins in the modulation of meiotic resumption and completion of oocyte maturation, as well as a beneficial effect on early embryonic development in mice.
Demonstration of 2-unsaturated C19-steroids in the urine of female Asian elephants, Elephas maximus, and their dependence on ovarian activity
Authors: Dehnhard M , Heistermann M , Goritz F , Hermes R , Hildebrandt T , Haber H
Published: March 2004

Air-borne volatile substances have been demonstrated to signal oestrus, induce ovulation and synchronize ovarian activity in different mammals. An oestrous-related pheromone of the female Asian elephant (Elephas maximus) is known to induce behavioural responses in elephant bulls. Additional data revealed that timing of oestrus in females with close social relationships tends to be synchronized. Therefore, urine from female Asian elephants might be expected to contain luteal phase-dependent volatile substances, which may function as additional chemical signals in this species. The aim of the present study was to identify such compounds and to investigate their pattern of excretion throughout the ovarian cycle. Urine samples were collected three times a week during the follicular phase and one to three times a week during the luteal phase from five adult female Asian elephants from a total of 13 non-conception cycles and one conception cycle, including the first 72 weeks of pregnancy. A simple headspace solid-phase microextraction method has been developed for quantification of urinary volatile substances and analysis was performed by gas chromatography. The comparison of urine collected during the follicular and the luteal phase indicated the presence of two luteal phase-dependent substances. Mass spectrometry was used to identify one substance as 5alpha-androst-2-en-17-one and a second substance as the corresponding alcoholic compound 5alpha-androst-2-en-17beta-ol. The 5alpha-androst-2-en-17beta-ol and -17-one profiles reflected cyclic ovarian activity with clear (10-20-fold) luteal phase increases. Furthermore, measurements of both compounds were correlated positively with the concentration of urinary pregnanetriol and indicated cycle duration (15.1 +/- 1.2 weeks) similar to that obtained from pregnanetriol measurements (15.2 +/- 1.6 weeks). The results demonstrate the presence of two luteal phase-specific steroidal volatile compounds in elephant urine. One of the substances, 5alpha-androst-2-en-17-one, has been demonstrated in human axillary bacterial isolates. The measurement of both volatile substances in elephant urine can be used for rapid detection of the stage of the ovarian cycle, as the analysis can be completed within 2 h.