Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Feminization”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,711 records · Page 95Linked to original sources
PubMed1988

Hepatic testosterone metabolism in male rats with portal bypass.

This study was performed to ascertain whether testosterone metabolism is altered in male rats with portal bypass, and whether such changes could contribute to the reduction in serum testosterone concentration and raised serum estrogen levels that are observed in this situation. The metabolic clearance rate of testosterone was determined by a prime-dose constant-infusion technique in male rats subjected to complete portal vein ligation and in sham-operated controls. Testosterone clearance was similar in rats with portal vein ligation and control rats (9.01 +/- 2.29 and 8.26 +/- 2.83 ml/min, respectively) but the clearance per gram of liver was greater in rats with portal vein ligation than in controls (1.18 +/- 0.18 versus 0.68 +/- 0.24 ml/min.g liver, p less than 0.0001). After 180 min of [3H]testosterone infusion, [3H]estradiol comprised 1.2% of plasma total radioactivity in male controls but was increased to 11% in rats with portal vein ligation (p less than 0.005). Similarly, biliary excretion of [3H]estradiol was eightfold greater in male rats with portal vein ligation compared with controls (p less than 0.001). In control male rats, the major metabolites of testosterone present in bile were 2 alpha-hydroxytestosterone, 16 alpha-hydroxytestosterone, and 7 alpha-hydroxytestosterone. Portal bypass was associated with reduced biliary excretion of 2 alpha-hydroxytestosterone and 16 alpha-hydroxytestosterone to approximately 50% of control, but there was no change in the excretion of 7 alpha-hydroxytestosterone. Conversely, portal bypass was associated with increased formation of dihydrotestosterone, indicating stimulated activity of testosterone 5 alpha-reductase. It is concluded that portal bypass in male rats is associated with altered pathways of testosterone metabolism and, in particular, with increased aromatization of testosterone to estradiol. The site of such estradiol formation has not been determined by this in vivo study. However, selective changes occurred in the regiospecific and stereospecific hydroxylation pathways of testosterone and in 5 alpha-reductase activity after portal bypass in male rats. It is concluded that portal bypass, in the absence of parenchymal liver damage, results in demasculinization and feminization of C19 steroid metabolism in the male rat liver. These metabolic changes could be revelant to the pathogenesis of changes in sexual characteristics in cirrhosis.

Animals↗
PubMed1992

In utero and lactational exposure of male rats to 2,3,7,8-tetrachlorodibenzo-p-dioxin. 2. Effects on sexual behavior and the regulation of luteinizing hormone secretion in adulthood.

When administered to postpubescent male rats, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) decreases plasma androgen concentrations. If such an androgenic deficiency were produced prenatally and/or early postnatally it could impair sexual differentiation of the central nervous system (CNS) and thereby alter male reproductive function. To examine this possibility, sexually dimorphic functions were assessed in male rats born to dams given TCDD (0.064, 0.16, 0.40, and 1.0 micrograms/kg, po) or vehicle on Day 15 of gestation. Masculine sexual behavior was assessed at approximately 60, 75, and 115 days of age. When TCDD-exposed males were caged with receptive control females their mount, intromission, and ejaculation latencies were far longer than normal; these effects were dose-related and were statistically significant at maternal doses as low as 0.16, 0.064, and 0.16 micrograms TCDD/kg, respectively. The numbers of mounts and intromissions to ejaculation were slightly increased by TCDD, while copulatory rates [(mounts+intromissions)/min] were significantly decreased at the three highest maternal doses. Except for a modest increase at the higher doses, TCDD had little effect on the postejaculatory interval. Following assessment of their masculine sexual behavior, the males were castrated and 6 weeks later tested for feminine sexual behavior (lordosis). After being primed with estradiol benzoate and treated with progesterone, males displayed dose-related increases in lordosis quotient and lordosis intensity in response to being mounted by another male. These effects were statistically significant at maternal doses as low as 0.16 and 0.40 micrograms TCDD/kg, respectively. To determine if perinatal TCDD exposure alters the sexually dimorphic regulation of luteinizing hormone (LH) secretion, the LH secretory responsiveness of the hypothalamic/pituitary axis to ovarian steroids was assessed. In unexposed, gonadectomized female rats primed with estradiol benzoate, progesterone injection produced a surge in plasma LH concentrations, whereas in similarly treated control males, plasma LH concentrations were unaffected by progesterone. In castrated, estradiol benzoate-primed male rats that were perinatally exposed to TCDD, progesterone treatment produced dose-related increases in plasma LH concentrations that were statistically significant at the two highest maternal doses. We conclude that in utero and lactational exposure to small amounts of TCDD demasculinizes and feminizes male rats. These effects cannot be accounted for by TCDD-induced hypophagia, modest reductions in adult plasma androgen concentrations, possible nonspecific changes in motor activity, or possible reductions in penile sensitivity to sexual stimulation. The altered sexual behaviors and LH secretion were observed when nearly all TCDD had been excreted (as evidenced by uninduced hepatic ethoxyresorufin-O-deethylase activity).(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed2005

Bacteriophage WO in Wolbachia infecting terrestrial isopods.

Wolbachia are maternally inherited intracellular alpha-proteobacteria that infect a wide range of arthropods. They are associated with a number of different reproductive phenotypes in arthropods and nematodes. In isopod crustacean, Wolbachia are responsible for feminization of genetic males in many species, and for cytoplasmic incompatibility in two species. In this paper, we report the first detection of phage WO from Wolbachia infecting terrestrial isopods. All Wolbachia strains tested in this study were infected with phage WO. Based on the orf7 phage sequence, we identified three different phage sequences in four Wolbachia strains. The phage of Wolbachia infecting Armadillidium vulgare seems to be not active, unlike other phages WO previously described in arthropods.

Animals↗
PubMed2005

Transmission and burden and the impact of temperature on two species of vertically transmitted microsporidia.

Microsporidia are unusual amongst eukaryotic parasites in that they utilize both vertical and horizontal transmission and vertically transmitted species can cause sex ratio distortion in their host. Here we study vertical transmission in two species of feminising microsporidia, Nosema granulosis and Dictyocoela duebenum, infecting a single population of the crustacean host Gammarus duebeni and measure the effect of temperature on parasite transmission and replication. N. granulosis was vertically transmitted to 82% of the host embryos and D. duebenum was transmitted to 72% of host embryos. For both parasites, we report relatively low parasite burdens in developing host embryos. However, the parasites differ in their pattern of replication and burden within developing embryos. Whilst N. granulosis undergoes replication during host development, the burden of D. duebenum declines, leading us to propose that parasite dosage and feminisation efficiency underlie the different parasite frequencies in the field. We also examine the effect of temperature on parasite transmission and replication. Temperature does not affect the percentage of young that inherit the infection. However, low temperatures inhibit parasite replication relative to host cell division, resulting in a reduction in parasite burden in infected embryos. The reduced parasite burden at low temperatures may underpin reduced feminization at low temperatures and so limit the spread of sex ratio distorters through the host population.

Amphipoda↗
PubMed2005

Spatial memory performance in androgen insensitive male rats.

Masculinization of the developing rodent brain critically depends on the process of aromatization of circulating testosterone (T) to its estrogenic metabolite 17beta-estradiol, which subsequently interacts with estrogen receptors to permanently masculinize the brain. However, it remains unclear what role other androgenic mechanisms may play in the process of masculinization. A novel way of examining this is through the study of male rats that express the tfm mutation of the androgen receptor (AR) gene; such males are fully androgen insensitive and manifest a female phenotype due to a failure of AR-mediated masculinization of peripheral structures. Because tfm-affected males develop secretory testes and have near-normal T titers during development, aromatization would be expected to proceed normally, and brain mechanisms may be developmentally masculinized despite the feminized periphery. We compared tfm-affected males (X(tfm)Y) with normal males and females in the Morris Water Maze, a task in which males typically perform better than females. Performance of tfm-affected males was intermediate between that of normal males and females. While an overall male superiority was found in the task, the X(tfm)Y group reached male-typical escape latencies faster than females. Furthermore, in the X(tfm)Y group, the granule cell layer of the dentate gyrus was significantly larger than in females. These results support the suggestion that that AR mediated mechanisms contribute to the masculinization of spatial behaviours and hippocampal morphology, and this may be independent of estrogenic processes.

Analysis of Variance↗
PubMed2006

Putting at risk what we know: reflecting on the drug-using subject in harm reduction and its political implications.

This paper provides a poststructuralist analysis of the cultural inscription of drug-using subjects in the neo-liberal discourses of contemporary harm reduction. We argue that although neo-liberal discourses downplay material constraints on individual human agency, divert policy and practice away from structural issues, limit the conception of effective strategies for harm reduction and ignore alternative formulations of the subject, they are also potentially empowering for drug users. Approximating the neo-liberal subject offers political benefits in terms of recognition, trust and legitimation, even as those values assume and reproduce understandings of behaviour, thought and sociality that fit only poorly the realities faced by many drug users. We explore this dilemma and consider three available directions in formulating the subject of harm reduction: (1) embracing the neo-liberal subject; (2) employing a more contextualised version of the neo-liberal subject; and (3) adopting alternative notions of subjectivity, extending the critique of the neo-liberal subject to all citizens, not solely drug users. To clarify some of these issues surrounding this strategic process, the paper considers another field in which struggles over the nature of the subject have been conducted--feminism. The intention is not to resolve the question of the most appropriate subject for harm reduction, but to sketch the political consequences of adopting particular models of the subject as a stimulus to further discussion and debate.

Culture↗
PubMed2003

Sexual and olfactory preference in noncopulating male rats.

In some species including rats, mice, gerbils, and rams, apparently normal males fail to copulate when repeatedly tested with receptive females. These animals are called "noncopulators (NC)," and the cause of this behavioral deficit is unknown. It has been shown that NC rats do not have hormonal alterations or deficits in the mechanisms that control penile function. The present study was designed to examine (Experiment 1) whether NC male rats prefer receptive females to sexually active males. In addition, the olfactory preference for bedding soiled from estrous or for anestrous bedding was investigated. These tests were performed in NC and copulating (C) male rats when the subjects were intact, gonadectomized (GDX), or GDX and treated with high doses of testosterone propionate (TP). Our results demonstrate that NC rats do not display sexual behavior even after high TP treatment. While C male rats have a clear preference for receptive females as opposed to a sexually active male, NC rats do not. In all hormonal conditions, the preference shown by NC rats for estrous bedding was significantly reduced in comparison to that seen in C rats. TP treatment in NC rats did not modify either partner or odor preference. In Experiment 2, we evaluated if NC rats are feminized and if it could be easier to induce feminine-like behavior by hormone treatment with estradiol benzoate (EB) or with EB plus progesterone (P) (EB+P). Odor preference for estrous or male bedding under these hormonal conditions was also compared. No differences between NC and C rats were found in feminine sexual behavior. In the olfactory test, we found that NC rats prefer odors from receptive females as opposed to male odors, but this preference is reduced compared to that of C rats. Males treated with EB or EB+P show no preference for female odors. These results demonstrate that treatment with EB or EB+P does not increase feminine sexual behavior in NC rats.

Animals↗
PubMed1999

A proposed multigeneration protocol for Japanese medaka (Oryzias latipes) to evaluate effects of endocrine disruptors.

Definitive data on reproductive impairment of chronically exposed populations may be required to assess the appropriateness of the existing test methods for hazard identification and prioritization of endocrine modulators. Multigeneration toxicity testing protocols for wildlife receptors are lacking. To help address this gap we describe a multigeneration fish assay using the freshwater fish, Japanese medake (Oryzias latipes). This test species has been used for the evaluation of carcinogenic, teratogenic and reproductive effects and is sensitive to estrogen exposure producing ovo-testis, altered biochemical parameters and phenotypic characteristics. Due to the short life cycle, a multigeneration test with medaka can be conducted in 1 year. Endpoints evaluated include: survival, growth, sex ratio, fecundity, embryonic lesion occurrence, embryonic stage development, gonadal and hepatic somatic indices, histopathology and biochemical parameters. As new endpoints are developed they can be incorporated into the protocol. Results of a positive control (17 beta-estradiol) study are presented to give an indication of the baseline associated with various test endpoints and to highlight the importance of nutrition in the experimental design. 17 beta-Estradiol treatment induced vitellogenin production in male and female medaka, feminized males, and disrupted egg production. The proposed protocol provides researchers with an effective multigeneration fish test that can be used to examine potential effects of stressors at the population, individual, cellular and subcellular level.

Animals↗
PubMed2004

Multihormonal control of vitellogenesis in lower vertebrates.

The comparative approach on how and when vitellogenesis occurs in the diverse reproductive strategies displayed by aquatic and terrestrial lower vertebrates is presented in this chapter; moreover, attention has been paid to the multihormonal control of hepatic vitellogenin synthesis as it is related to seasonal changes and to vitellogenin use by growing oocytes. The hormonal mechanisms regulating vitellogenin synthesis are also considered, and the effects of environmental estrogens on the feminization process in wildlife and humans have been reported. It is then considered how fundamental nonmammalian models appear to be, for vitellogenesis research, addressed to clarifying the yolkless egg and the evolution of eutherian viviparity.

Amphibians↗
PubMed1996

Feminist psychodynamic psychotherapy of eating disorders. Theoretic integration informing clinical practice.

Ideas derived from feminism and psychoanalytic theory can be combined for the integrated treatment of eating disorder patients. For a large subgroup of patients who continue to have a poor quality of life or inadequate symptom control (despite customary psychopharmacologic and cognitive behavioral interventions), feminist psychodynamic psychotherapy may prove lifesaving. This article explores how the patient may come to grasp more deeply the multiple roles her symptom has played in her psychological survival. Practical suggestions to enrich the psychotherapy as the patient traverses the natural struggles of adult life are emphasized. The importance of understanding and working with transference and countertransference issues while helping the patient accept life's paradoxes, ambiguities, and potential avenues for growth are underscored. The author reviews eight specific areas that warrant attention in psychotherapeutic exploration from a feminist psychoanalytic perspective (Culture as Bedrock Issue; Gender as Organizer of Behavior, Ownership of Body; Moral Development; Development of Personal Voice; Emphasis on Adult Development; Sexual Concerns; and Aggressive Conflicts).

Culture↗
PubMed1997

Nurse education: a feminist approach.

Nursing is predominantly a female profession. This paper seeks to explore the implications of this for curriculum design and suggests that insights from feminist theory should be applied to curricula. To insert the 'subject' of feminism into the curriculum is different from allowing its theories to affect the design of the curriculum itself. The paper seeks to justify such a change and asks what the resulting characteristics would be. Would such a curriculum change succeed and what would be its limitations? The paper concludes by highlighting the implications for nurse education.

Curriculum↗
PubMed2001

From salvation to civics: service to the sick in nursing discourse.

This paper explores the emergence of civics discourse in early 20th-century nursing. It foregrounds this discussion with an analysis of the attempt to secularise nursing that occurred in 1789 during the French Revolution. It then examines the discursive displacement of religious vocational fervour by civic and patriotic imperatives during the first two decades of the 20th century. Contemporary scholars have portrayed nursing's professional development as characterised by tension between the professional elitist agenda of the nursing leadership, and the rank and file positioning of nursing as a female occupation. By contrast, this paper focuses on the porosity of nursing to broader trends such as civic discourse, the labour movement, feminism and socialism, and works to shift our understanding of nursing's professional history from a dialectical model (professional versus industrial), to one of multiplicity in political and ethical values. It argues that civic and patriotic discourse provided the framing for the secular nurse's subjectivity and the mechanism by which nurses negotiated the moral dangers of care of the sick and male bodies without the protection of vow or veil.

Christianity↗
PubMed2003

Post-diagnostic abortion in Germany: reproduction gone awry, again?

Routine use of prenatal diagnostic technologies (PDTs) such as ultrasound and amniocentesis result in the detection of a small percentage of fetal anomalies. For those women faced with the diagnosis of fetal disability, a decision must be made to continue or terminate the pregnancy. When the diagnosis is merely hypothetical, the discursive specter of post-diagnostic abortion is shaped by social and historical contexts in which interested discourses (regional, political, ethical, and religious) weigh in with varying degrees of authority and influence. However, when the diagnosis is actual, in this sample population of women, an estimated minimum of 90% opt to terminate their pregnancies. Data collected at two German hospitals-one in former East Germany, one in former West Germany-illuminate rates of PDT use and provide data with which to discuss the specter of post-diagnostic abortion in relation to mainstream medical discourses, Germany's divided history, abortion politics, feminism, disability activism, and religion. These data demonstrate how reproductive discourses are shaped by ideological and historical contingencies, even when women's ultimate reproductive decisions are not.

Abortion, Eugenic↗
PubMed1997

Integrating lay and nurse-midwifery into the U.S. and Canadian health care systems.

The integration of midwifery into the health care systems in the U.S. and Canada has invoked scholars to speak of a "rise of midwifery". Despite the gains that the profession of midwifery has made in both countries, there are some interesting differences in how midwifery is organized and practised in these two settings. Briefly, in the U.S. midwifery currently exists as a profession divided between nurse- and non-nurse-midwives, or "lay" midwives, with greater acceptance and legitimacy garnered by the former, whereas midwifery in some jurisdictions in Canada has gained legitimacy as a unified profession separate from nursing. An analysis of the differences in the development and organization of lay and nurse-midwifery in Canada and the U.S. highlights the importance of differences in the system of health professions in these two countries, the role of the state in this system, and the relationship between feminism, midwifery and the state on the outcome of efforts to integrate midwifery.

Canada↗
PubMedDate not supplied

Women's health care: a new paradigm for the 21st century.

Oppression based on gender exists in all aspects of women's lives and transcends contemporary cultures, economic systems, and even health care services. Radical feminism provides an alternative philosophic framework of health care that is based on a women-centered viewpoint, with the experiences of women as its unifying philosophy. Midwifery is a means to apply this new philosophic approach to the health care of women. A partnership between midwifery and feminist philosophy will allow women's voices to be heard, while guiding research in women's health care in new directions, and illuminating new approaches to current health problems. The new millennium provides an opportunity to explore an alternative framework and philosophy that will change the current paradigm of women's health care.

Female↗
PubMed2000

A history of women and feminist perspectives in community psychology.

Using an historical framework, we document and assess efforts to include women, women's issues, and feminism in community psychology and in the Society for Community Research and Action (SCRA). Initiatives of the SCRA Task Force/Committee on Women are traced from its inception to present. We also chronicle the dilemmas and difficulties of moving toward a feminist community psychology. The history is divided into five phases. Each phase is described in terms of women's involvement in the field and efforts to integrate feminist content into research and practice of the field. Reflections on the qualities of contexts that have both supported and inhibited inclusion are identified. We look to this history to try to understand the observation that while women have been increasingly visible in leadership roles and women's professional development has been encouraged, less progress has been made toward building a feminist community psychology.

Community-Institutional Relations↗
PubMed2000

Feminist approaches to social science: epistemological and methodological tenets.

This paper is a primer for community psychologists on feminist research. Much like the field of community psychology, feminist scholarship is defined by its values and process. Informed by the political ideologies of the 1970s women's movement (liberal, radical, socialist feminism, and womanism), feminist scholars reinterpreted classic concepts in philosophy of science to create feminist epistemologies and methodologies. Feminist epistemologies, such as feminist empiricism, standpoint theory, and postmodernism, recognize women's lived experiences as legitimate sources of knowledge. Feminist methodologies attempt to eradicate sexist bias in research and find ways to capture women's voices that are consistent with feminist ideals. Practically, the process of feminist research is characterized by four primary features: (1) expanding methodologies to include both quantitative and qualitative methods, (2) connecting women for group-level data collection, (3) reducing the hierarchical relationship between researchers and their participants to facilitate trust and disclosure, and (4) recognizing and reflecting upon the emotionality of women's lives. Recommendations for how community psychologists can integrate feminist scholarship into their practice are discussed.

Community Mental Health Services↗
PubMed2000

Attitude toward women's societal roles moderates the effect of gender cues on target individuation.

In 4 studies, participants read trait descriptions and formed impressions of 2 male and 2 female targets. They then attempted to recall which traits had described each target. As predicted, participants with a "progressive" attitude toward women's rights and roles (J. T. Spence, R. L. Helmreich, & J. Stapp, 1973) made fewer within-group recall errors for female targets than for male targets, indicating greater individuation of the female targets, whereas participants with a "traditional" attitude made fewer errors for male targets. The findings of a 5th study suggested that progressive participants were motivated to individuate women by their belief that it is important to improve the status of women and other groups low in power and by their identification with women and feminism. Traditional participants' greater individuation of men was believed to stem from their perception of men's higher status (as confirmed by pretests) and their acceptance of the status quo.

Adult↗