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The application of postmodern thought to the clinical practice of psychoanalytic psychotherapy.

The purpose of this article has been to acquaint psychoanalysts and psychoanalytically oriented psychotherapists with some of the most current ideas in philosophy and psychology, which have crucial implications for our professional organizations and our clinical work. The basic stance of this postmodern thinking constitutes a challenge to what is called foundationalism, which dominated scientific and philosophical thought until recently. In place of foundationalism, even in the production of scientific or philosophical works, we could hope for an ongoing dialogue between a king or queen who states the basic theoretical orientation, the loyal opposition that looks for inconsistencies and kinks in it, the jester who deconstructs the whole thing and introduces parenthetical digressions, and finally, a secret society of organization that functions to hold the adherents of the theory together and provide them with a unifying ego ideal. Postmodern thought is described and there is some discussion of its "four horsemen," Derrida, Rorty, Foucault, and Lyotard, who in general question the possibility of whether any form of interpretation can be thought of as related to reality or the truth. My own point of view is that an intermediate position is necessary rather than a binary opposition between nihilism and foundationalism or more specifically, postmodernism and traditional psychoanalysis. That is to say, within certain horizons and with an understanding of the cultural and historical referents that always affect and delimit both the patient and the therapist, it is still possible to reach conceptions about what is going on both in the psychoanalytic process and the psyche of the patient that have at least a tentative "truth." Careful attention to the patient's material following an interpretation can provide clues about the validity of our conception at the time. But the horizons and historicity that delimit all "truth" reduce the authority and the stature of the analyst, make the analyst less of an arbiter of what is "reality," and focus greater attention on the therapist-patient dyad, which is consistent with the modern trend in psychoanalytic treatment anyway. The notion of social constructions as constituting the psychoanalytic process was discussed and it was suggested that this notion suffers from the lack of sufficient attention to the historical determinants of how a given individual reacts in a given situation. A patient will react differently to different therapists, depending on the transference or projective identifications that the patient brings to the treatment, regardless of the interpersonal interaction. This is in opposition to the idea that transference is primarily an effect of the therapist-patient dyad, and preserves a major aspect of traditional Freudian theory. The dangers of postmodern thought disintegrating into nihilism are described, and the limitations of so-called postmodern thought are discussed, including the intrinsic paradoxical nature of any postmodern proposition. At the same time, postmodern thought is useful in calling attention to the "space of the Other" in human affairs, to the tendency to form binary oppositions in which the second element in each binary pair is part of the Other and is depreciated, and to remind us that there are always further interpretations of the narrative that emerges from the psychoanalytic situation. The feminization of psychotherapy and its relationship to feminism are important current issues. Postmodern thought is valuable in responding to the common complaint of feminists about Nietzsche's attitude toward women; postmodernist approaches emphasize the ambiguous and the allegorical aspects of Nietzsche's thought, to the extreme orf Derrida's contention that Nietzsche is not really interpretable at all. At the same time feminists legitimately object to postmodernist erosion of the grounds for political action. (ABSTRACT TRUNCATED)

Female↗

Disturbances in sexual differentiation of rat foetuses following spironolactone treatment.

Pregnant rats were treated with 40 mg spironolactone (sp) po from the 13th to the 21st day p.c. The foetuses were prepared and histologically examined on day 22. The male foetuses showed distinct signs of feminization especially of the external genitalia. The anogenital distance was nearly 48% shorter than that of the controls. The prostatic utricle persisted more distinctly, and the number and size of the prostatic buds were significantly reduced. The degree of feminization of the male foetuses which is achieved under the influence of sp (40 mg/day) is the same as that which can be induced by 1--3 mg cyproterone acetate.

Animals↗

Effects of hypothalamic deafferentation at different levels on metabolism of hepatic steroids in rats.

The metabolism of 4-[4-14C]androstene-3,17-dione in the microsomal fraction of livers from male and female rats was investigated after hypothalamic deafferentation at two levels. It was found that frontal deafferentation at the retrochiasmatic level caused a complete 'feminization' of hepatic steroid metabolism in the male rat but was without effect in the female animal. Transection rostral to the suprachiasmatic nuclei was without effect in both sexes. A complete transition from male to female hepatic steroid metabolism after retrochiasmatic deafferentation was reached on day 4 after the operation and persisted for at least 10 weeks. The present results, taken together with previous investigations, indicate that the release of a 'feminizing' factor from the pituitary gland of the male rat is inhibited by a factor produced in, or transported through, the periventricular anterior hypothalamic region including the suprachiasmatic area. No effect on the hepatic steroid metabolism was observed after binding of the rats suggesting that a diurnal rhythm is not essential to this control mechanism.

Androstenedione↗

[Endocrine disturbances in liver cirrhosis--focused on sex hormones].

Various endocrine disturbances are often observed in the patients with liver cirrhosis. We focused this paper on the sex hormones. Clinical features of male cirrhotic subjects are feminization(gynecomastia etc) and hypogonadism(testicular atrophy, reduced fertility, loss of libido, impotence etc). Chief abnormalities of sex hormones are a decrease in serum testosterone levels and an increase in serum estrogen levels accompanied by an increase in ratio of estrogen to testosterone in the patients with severe liver cirrhosis associated with the severity of hepatic dysfunction. Hyperestrogenization may be related with feminization of male cirrhotic subjects, whereas hypogonadism is the result of alcohol abuse per se, rather than the indirect consequence of liver cirrhosis.

Estrogens↗

Transabdominal pelvic sonography in the preoperative evaluation of patients with congenital adrenal hyperplasia.

PURPOSE: We assessed the clinical value of transabdominal pelvic sonography in the preoperative evaluation of patients with congenital adrenal hyperplasia (CAH) who required feminizing genitoplasty. METHODS: From 1987 to 1998, 31 patients with female pseudohermaphroditism due to CAH underwent feminizing genitoplasty. The median age of the patients was 9 months (range, 1-18 years). Radiologic evaluation performed before surgical reconstruction included retrograde genitography in the first 10 patients and sonographic examination in all 31 patients. Imaging was used to evaluate the anatomic positions and the length of the vagina, whether the junction of the vagina and the urogenital sinus occurred distal or proximal to the pelvic floor, and the presence of internal genitalia. RESULTS: Abdominal sonography identified internal female genitalia in all 31 patients, identified the anatomic shape and position of the vagina in 30 patients (97%), and confirmed the site of communication between the vagina and the urogenital sinus relative to the pelvic floor in 28 patients (90%). Sonographic findings were confirmed by intraoperative panendoscopy. Genitography was less useful than sonography, identifying the site of communication between the vagina and urogenital sinus in only 6 (60%) of 10 patients. CONCLUSIONS: In patients with CAH undergoing vaginal reconstruction, sonography provides adequate information about the anatomy of the vagina and urogenital sinus for surgical decision-making.

Adolescent↗

Hormonal perturbations in patients with testicular cancer treated with cisplatin.

Patients with testicular cancer treated with cisplatin can undergo feminization that is understood poorly. Rat model studies recently showed that cisplatin can feminize in part the profile of hepatic steroid-metabolizing enzymes and circulating hormone levels. This study was undertaken to determine whether cisplatin similarly might contribute to the perturbations in gonadotropin or steroid hormone levels that can occur in patients undergoing cisplatin-based treatment for testicular cancer. Analysis of serum free testosterone, total testosterone, and androstenedione levels revealed that these hormones were not altered significantly in patients during a 38-week period of cisplatin-based treatment and follow-up. Estradiol levels were elevated before chemotherapy and were reduced to normal levels during treatment. This reduction was attributed to the cytotoxic effect of chemotherapy on the tumors and the resultant reduction in serum chorionic gonadotropin levels. Serum dihydrotestosterone (DHT) levels were normal before chemotherapy but progressively became elevated during treatment with cisplatin in five of ten patients examined. The rise in DHT may relate to the previously described increase in hepatic androgen 5 alpha-reductase activity in cisplatin-treated rats. Levels of the gonadotropins, luteinizing hormone, and follicle-stimulating hormone (FSH) were normal before cisplatin-based treatment was administered; however, FSH was elevated selectively during chemotherapy. This selective induction of FSH may reflect an effect of cisplatin on the hypothalamic secretion of gonadotropin-releasing hormone. Taken together, these findings suggest that cisplatin contributes to the perturbation of steroid and peptide hormone levels in patients with testicular cancer and perhaps in others undergoing cisplatin-based chemotherapy.

Adult↗

The hierarchical relation between X-chromosomes and autosomal sex determining genes in Drosophila.

The classical balance concept of sex determination in Drosophila states that the X-chromosome carries dispersed female-determining factors. Besides, a number of autosomal genes are known that, when mutant, transform chromosomal females (XX) into pseudomales (tra), or intersexes (ix, dsx, dsx). To test whether large duplications of the X-chromosome have a feminizing effect on the sexual phenotype of these mutants, we constructed flies that were mutant for ix, dsx, dsx or tra and had two X-chromosomes plus either a distal or a proximal half of an X-chromosome. These or even smaller X-chromosomal fragments had a strong feminizing effect when added to triploid intersexes (XX; AAA). In the mutants, however, no shift towards femaleness was apparent. We conclude that enhancing the female determining signal is ineffective in flies that are mutant for an autosomal sex determining gene, and therefore, that these genes are under hierarchical control of the signal given by the X:A ratio. Parallels between sex-determining and homeotic genes are drawn.

Journal Article↗

Role of peanut-lectin-affinity molecules (PLAM) on primordial germ cells in the initial determination of sex in anura.

Peanut lectin (PNA) or N-acetylgalactosamine (galNA, a part of the disaccharide unit which is recognized by PNA) was injected into the coelomic cavity of anuran larvae at the developmental stages during which the genital ridges were growing, and the effect of these compounds on the initial determination of gonadal sex was examined. The treatment with PNA tended to inhibit (or perturb) the expression of feminizing gene(s) in Rana japonica, and of both feminizing and masculinizing genes in R. nigromaculata. In contrast, treatment with galNA suppressed the expression of masculinizing gene(s) considerably. In terms of the initial determination of gonadal sex during normal development, these results suggest that the PNA-affinity molecule (PLAM) of primordial germ cells acts as a trigger for the expression of genes that control sexual differentiation of somatic cells. Furthermore, the somatic cells (perhaps mesenchymal and/or epithelial cells), which respond to the stimulus via the PLAM of primordial germ cells, may differ in terms of the threshold for such a response between genetic males and females. This result suggests the mesenchymal and/or epithelial cells are not sexually predetermined, but rather that sexual determination follows the response to some signal(s) mediated by the PLAM.

Acetylgalactosamine↗

Mushroom bodies are not required for courtship behavior by normal and sexually mosaic Drosophila.

To elucidate the effect of feminization of male Drosophila brain cells on courtship control, we performed a large scale screening of expression drivers that can suppress male-specific behavior with transformer gene expression. Two drivers caused essentially total courtship suppression. The expression pattern of these drivers did not show any correlation with the mushroom bodies or the antennal lobes, the regions that have been suggested to play important roles in courtship. Ablation of mushroom bodies using hydroxyurea treatment did not affect this courtship suppression. The ablation did not change either wild-type heterosexual behavior or bisexual behavior caused by transformer expression driven by the same drivers used in the previous studies to suggest the involvement of the mushroom bodies in courtship. Our results show that feminization of different nonoverlapping cells in other parts of the protocerebrum was sufficient to cause the same bisexual or suppressed-courtship phenotype. Thus, contrary to previous assumptions, the mushroom bodies are not required for the control of courtship. Present evidence supports its mediation by other distributed protocerebral regions.

Animals↗

A risk assessment of atrazine use in California: human health and ecological aspects.

A risk assessment of the triazine herbicide atrazine has been conducted by first analyzing the toxicity database and subsequently estimating exposure. Margins of safety (MOS) were then calculated. Toxicity was assessed in animal studies and exposure was estimated from occupational and dietary sources. In acute toxicity studies, atrazine caused developmental toxicity in the rabbit [no observed effect level (NOEL) 5 mg kg(-1) day(-1)] and cardiotoxicity in a dog chronic study (NOEL 0.5 mg kg(-1) day(-1)); cancer (mammary glands) resulted from lifetime exposure. The mammary tumors, which occurred specifically in female Sprague-Dawley rats, were malignant, increased in a dose-dependent manner and were also observed with other, related triazines. Evidence for a genotoxic basis for these tumors was either equivocal or negative. Triazines have been shown to be clastogenic in Chinese hamster ovary cells, in vitro, but without showing a convincing dose/response relationship. Atrazine can be converted into genotoxic N-nitrosoatrazine in the environment or the digestive system, suggesting that N-nitrosamines derived from triazines could be oncogenic. However, it was concluded that N-nitrosotriazines are unlikely to play a significant role in triazine-induced rat mammary gland tumors. An endocrine basis for the mammary tumors, involving premature aging of the female SD rat reproductive system, has been proposed. A suppression of the luteinizing hormone surge during the estrus cycle by atrazine leads to the maintenance of elevated blood levels of 17beta-estradiol (E2) and prolactin. The mechanism for tumor development may include one or more of the following: the induction of aromatase (CYP19) and/or other P450 oxygenases, an antagonist action at the estrogen feedback receptor in the hypothalamus, an agonist action at the mammary gland estrogen receptor or an effect on adrenergic neurons in the hypothalamic-pituitary pathway. None of these has been excluded as a target because there has been a lack of a rigorous attempt to address the mechanism of action for mammary tumors at the molecular level. The potential occupational exposure to atrazine was assessed during mixing, loading and application. Absorbed daily dosage values were 1.8-6.1 microg kg(-1) day(-1). The MOS values (animal NOEL/human exposure) for short-term (acute) exposure were 820-2800. Longer-term occupational exposure and risk were also calculated. Detectable crop residues are generally absent at harvest. Theoretical calculations of acute dietary exposure used tolerance levels, along with secondary residues, and water, for which there is a maximum contamination level; atrazine plus the three main chlorotriazine metabolites were combined. MOS values were above 2000 for all population subgroups. Dietary exposure to atrazine is therefore extremely unlikely to result in human health hazard. Recent publications have reported a possible feminization of frogs, measured in laboratory and field studies. This is assumed to be due to the induction of aromatase, but no measurements of enzyme activity have been reported. In field studies, the water bodies with the greatest numbers of deformed frogs sometimes had the lowest concentrations of atrazine. Other studies have also cast doubt on the feminization theory, except perhaps at very high levels of atrazine. Epidemiology studies have investigated the possibility that atrazine may result in adverse effects in humans. Although some studies have claimed that atrazine exposure results in an elevated risk of prostate cancer, the published literature is inconclusive with respect to cancer incidence.

Animals↗

On the control of oocyte meiotic maturation and ovulation in Caenorhabditis elegans.

Prior to fertilization, oocytes undergo meiotic maturation (cell cycle progression) and ovulation (expulsion from the ovary). To begin the study of these processes in Caenorhabditis elegans, we have defined a time line of germline and somatic events by video microscopy. As the oocyte matures, its nuclear envelope breaks down and its cell cortex rearranges. Immediately thereafter, the oocyte is ovulated by increasing contraction of the myoepithelial gonadal sheath and relaxation of the distal spermatheca. By systematically altering the germ cell contents of the hermaphrodite using mutant strains, we have uncovered evidence of four cell-cell interactions that regulate maturation and ovulation. (1) Both spermatids and spermatozoa induce oocyte maturation. In animals with a feminized germline, maturation is inhibited and oocytes arrest in diakinesis. The introduction of sperm by mating restores maturation. (2) Sperm also directly promote sheath contraction. In animals with a feminized or tumorous germline, contractions are infrequent, whereas in animals with a masculinized germline or with sperm introduced by mating, contractions are frequent. (3 and 4) The maturing oocyte both induces spermathecal dilation and modulates sheath contractions at ovulation; dilation of the distal spermatheca and sharp increases in sheath contraction rates are only observed in the presence of a maturing oocyte.

Animals↗

mag-1, a homolog of Drosophila mago nashi, regulates hermaphrodite germ-line sex determination in Caenorhabditis elegans.

The Caenorhabditis elegans gene mag-1 can substitute functionally for its homolog mago nashi in Drosophila and is predicted to encode a protein that exhibits 80% identity and 88% similarity to Mago nashi (P. A. Newmark et al., 1997, Development 120, 3197-3207). We have used RNA-mediated interference (RNAi) to analyze the phenotypic consequences of impairing mag-1 function in C. elegans. We show here that mag-1(RNAi) causes masculinization of the germ line (Mog phenotype) in RNA-injected hermaphrodites, suggesting that mag-1 is involved in hermaphrodite germ-line sex determination. Epistasis analysis shows that ectopic sperm production caused by mag-1(RNAi) is prevented by loss-of-function (lf) mutations in fog-2, gld-1, fem-1, fem-2, fem-3, and fog-1, all of which cause germ-line feminization in XX hermaphrodites, but not by a her-1(lf) mutation which causes germ-line feminization only in XO males. These results suggest that mag-1 interacts with the fog, fem, and gld genes and acts independently of her-1. We propose that mag-1 normally allows oogenesis by inhibiting function of one or more of these masculinizing genes, which act during the fourth larval stage to promote transient sperm production in the hermaphrodite germ line. When the Mog phenotype is suppressed by a fog-2(lf) mutation, mag-1(RNAi) also causes lethality in the progeny embryos of RNA-injected, mated hermaphrodites, suggesting an essential role for mag-1 during embryogenesis. The defective embryos arrest during morphogenesis with an apparent elongation defect. The distribution pattern of a JAM-1::GFP reporter, which is localized to boundaries of hypodermal cells, shows that hypodermis is disorganized in these embryos. The temporal expression pattern of the mag-1 gene prior to and during morphogenesis appears to be consistent with an essential role of mag-1 in embryonic hypodermal organization and elongation.

Animals↗

Effect of dichlorodiphenyltrichloroethane on sex determination of the common snapping turtle (Chelydra serpentina serpentina).

Recent evidence indicates that 1,1,1-trichloro-2, 2-bis(p-chlorophenyl)ethane (DDT) and some of its metabolites alter reproductive and endocrine function in wildlife. Exposure to such endocrine-disrupting compounds during embryonic development can affect sexual differentiation. The authors tested the hypothesis that dichlorodiphenyltrichloroethane (p,p'-DDE) causes feminization of the common snapping turtle (Chelydra s. serpentina), a species with temperature-dependent sex determination, during embryonic development. Eggs from eight clutches (total eggs tested=237) were incubated at a male-producing temperature (26 degrees C). At stage 14 of embryonic development, p,p'-DDE was applied topically at four concentrations and estrogen (estradiol-17 beta) was applied as a positive control. Although application of estrogen did induce female development at this temperature, application of p,p'-DDE did not affect sex determination at the exposure levels used. Residue analysis indicated that the amount of p,p'-DDE detected in the eggs 72 h after application was considerably less than the concentrations applied. However, the amounts that penetrated the shells were comparable to levels which have been found in moderately contaminated sites in the Great Lakes. These results indicate that p, p'-DDE, at levels that exist in the environment in the Great Lakes, does not cause the feminization of snapping turtles during embryonic development.

Animals↗

Sensitive stages for the effects of temperature on gonadal aromatase activity in embryos of the marine turtle Dermochelys coriacea.

Many data suggest an involvement of estrogens in gonadal differentiation in reptiles with temperature-dependent sex determination (TSD). However, the site of estrogen synthesis in two species of freshwater turtles is unclear. In Emys orbicularis, estrogens were shown to be produced by the gonads, whereas in Trachemys scripta, gonadal steroids were not detected. The marine turtle Dermochelys coriacea exhibits TSD but in gonadal development, ovarian differentiation is delayed. Gonadal aromatase activity and estrogen content in this species were measured in embryos incubated at 27 degrees and in embryos incubated at 30.5 degrees, respectively, masculinizing and feminizing temperatures within the range of temperatures found in natural nests. At all stages studied, aromatase activity was present and found to be higher at 30.5 degrees than at 27 degrees. Estrogens were only found at 30.5 degrees. The effects of temperature shifts on gonadal aromatase activity were then examined. Eggs were shifted from 27 to 35 degrees (feminizing temperature) at different embryonic stages and exposed to 35 degrees for 6 days. An increase in gonadal aromatase activity, although with significant individual variations, was seen only when eggs were shifted between stages 23 and 27. These stages are in the range of the thermosensitive stages for sexual differentiation of the gonads determined in other turtles. These results are similar to those previously obtained in E. orbicularis and agree with a key role for endogenous estrogens in gonadal differentiation of reptiles with TSD.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Wolbachia bacteria effects after experimental interspecific transfers in terrestrial isopods.

Wolbachia bacteria are intracellular parasites, vertically transmitted from mothers to offspring through the cytoplasm of the eggs. They manipulate the reproduction of their hosts to increase in frequency in host populations. In terrestrial isopods for example, Wolbachia are responsible for the full feminization of putative males, therefore increasing the proportion of females, the sex by which they are transmitted. Vertical transmission, however, is not the only means for Wolbachia propagation. Infectious (i.e., horizontal) transmission between different host species or taxa is required to explain the fact that the phylogeny of Wolbachia does not parallel that of their hosts. The aim of this study was to investigate, by experimental transinfections, whether Wolbachia strains could be successfully transferred to a different, previously uninfected isopod host. While Wolbachia survived in all the studied recipient species, vertical transmission was efficient only in cases where donor and recipient species were closely related. Even in this case, Wolbachia strains did not always keep their ability to entirely feminize their host, a deficiency that can be link to a low bacterial density in the host tissues. In addition, Wolbachia infection was associated with a decrease in host fertility, except when the bacterial strain came from the same host population as the recipient animals. This suggest that Wolbachia could be adapted to local host populations. It therefore seems that isopod Wolbachia are highly adapted to their host and can hardly infect another species of hosts. The successful infection of a given Wolbachia strain into a new isopod host species therefore probably requires a strong selection on bacterial variants.

Animals↗

The disparate maternal aunt-uncle ratio in male transsexuals: an explanation invoking genomic imprinting.

A significant skewing in the sex ratio in favour of females has been reported for the families of homosexual men such that there are fewer maternal uncles than aunts. This finding is repeated for a large series of transsexual families in this study. Four hundred and seventeen male-to-female transsexuals and 96 female-to-male transsexuals were assessed. Male-to-female transsexuals have a significant excess of maternal aunts vs. uncles. No differences from the expected parity were found for female-to-male transsexuals or on the paternal side. A posited explanation for these findings invokes X inactivation and genes on the X chromosome that escape inactivation but may be imprinted. Our hypothesis incorporates the known familial traits in the families of homosexuals and transsexuals by way of retention of the grand parental epigenotype on the X chromosome. Generation one would be characterized by a failure to erase the paternal imprints on the paternal X chromosome. Daughters of this second generation would produce sons that are XpY and XmY. Since XpY expresses Xist, the X chromosome is silenced and half of the sons are lost at the earliest stages of pregnancy because of the normal requirement for paternal X expression in extra-embryonic tissues. Females survive by virtue of inheriting two X chromosomes, and therefore the possibility of X chromosome counting and choice during embryonic development. In generation three, sons inheriting the paternal X after its second passage through the female germline survive, but half would inherit the feminizing Xp imprinted genes. These genes could pre-dispose the sons to feminization and subsequent development of either homosexuality or transsexualism.

Family Characteristics↗

Effects of maternal exposure to a reconstituted mixture of polychlorinated biphenyls on sex-dependent behaviors and steroid hormone concentrations in rats: dose-response relationship.

In a previous experiment, maternal exposure to a polychlorinated biphenyl (PCB) mixture reconstituted according to the congener pattern found in human breast milk resulted in decreased aromatase activity in the brain of newborn male rats, together with feminization of sweet preference behavior in adult male littermates. Both mixtures led to similar reductions of serum testosterone and testes weights. The purpose of the present study was (1) to examine the dose-response relationship for the reconstituted mixture and (2) to study if the rewarding properties of testosterone are affected at levels sufficient to alter sweet preference behavior. Female rats were fed diets with 0, 5, 20, or 40 mg PCBs/kg diet, resulting in an average daily intake of 0, 0.5, 2, or 4 mg/kg body wt. Exposure started 50 days prior to mating and was continued until birth of the offspring. A dose-dependent elevation of sweet preference was found in adult male offspring, indicating feminization of this sexually dimorphic behavior. Examination of conditioned place preference revealed a preference for the testosterone-paired side at the highest exposure condition. In weanling female offspring, dose-dependent reductions of serum testosterone and estradiol concentrations were detected. In addition, testosterone concentrations were reduced in a dose-dependent manner in adult male littermates long after termination of exposure. PCB concentrations in adipose tissue from offspring of the low dose group (0.5 mg/kg body wt) were approximately 10 times higher than values at the upper margin of current human exposure. Taken together, results indicate long-lasting and dose-dependent changes in sex-dependent behaviors and levels of sex steroid hormones in rats following developmental exposure to a PCB mixture that resembles the breast milk pattern.

Animals↗

Daudi supernatant, unlike other H-Y antigen sources, exerts a sex-reversing effect on embryonic chick gonad differentiation.

In vitro cultures of intact chick gonads (organ cultures) and reaggregation cultures of dispersed gonad cells (roller cultures) were made. Gonads or gonad cells from 7-day-old chick embryos, at the stage when sex-specific differentiation begins, were cultured in the presence of presumed H-Y antigen-containing supernatants, or co-cultured in the presence of H-Y antigen-producing cell lines. The H-Y antigen-producing cells tested were of human, mouse, bovine and chicken origin. During organ culture, addition of supernatant of the human lymphoma cell line Daudi, or co-culture with Daudi cells, stimulated a clear proliferation of the germinal epithelium in male gonads, indicating feminization. A similar effect was obtained by treatment with estradiol. In reaggregation culture, the increase in nuclear size of germ cells was chosen as a parameter for feminization. A significant increase of germ cell nuclear size was observed in gonads cultured in the presence of Daudi supernatant. In both organ cultures and reaggregation cultures, other tested H-Y antigen sources and semi-purified H-Y antigen fractions did not exert significant effects on differentiation of the gonads or on the average area of the germ cell nuclei. These findings suggest that it is not H-Y antigen, but another protein produced by Daudi cells, that might be responsible for the sex-reversing effects.

Animals↗