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At least 37 records · Page 2Linked to original sources
PubMed1986

Gonadal tumor and H-Y antigen in 46,XY pure gonadal dysgenesis.

Six cases of Swyer's syndrome (46,XY pure gonadal dysgenesis) are reported. Three patients, without gonadal tumor, had female H-Y antigen. Three patients, after gonadal tumor ablation, had intermediate H-Y antigen levels. Repeated blood samples were obtained from two siblings. H-Y antigen level in the first sibling, who presented with a gonadoblastoma and underwent a gonadectomy before the H-Y assays, was intermediate, and did not show any significant variation for 21 months. H-Y antigen level in the second sibling showed an increase in the male range, presumably due to the presence of gonadoblastomas. After resection of the tumors, H-Y antigen level became intermediate. These findings suggest a relation between the tumorization potentiality of the gonadal remnants and the H-Y antigen levels in 46,XY pure gonadal dysgenesis.

Adolescent↗
PubMed2002

Complete XY gonadal dysgenesis and aspects of the SRYgenotype and gonadal tumor formation.

XY gonadal dysgenesis can be classified as either complete or incomplete according to gonadal morphology. The disease is a sex-reversal disorder resulting from embryonic testicular regression sequences and is induced by mutations in the sex-determining region Y ( SRY) gene. The incidence of SRY mutations is thought to be approximately 20%. As the disease is characterized by a frequent complication of gonadal tumors, patients are usually advised to undergo prophylactic gonadectomy. In this study, we searched for mutations in SRY open reading frames from three patients with the complete form of XY gonadal dysgenesis, and detected missense mutations in two patients. Combined with the results of our previous study, in which SRY abnormalities were also detected in two out of three complete-type patients, the final incidence of SRY abnormalities was 67% (four of six patients), which is much higher than previously thought. The incidence of gonadal tumor formation in patients with SRY abnormalities was 50% (two of four patients), which is similar to the result of a metanalysis of patients with SRY abnormalities that revealed an incidence of 52.5%. Therefore, it is possible that the lower incidences of SRY abnormalities previously reported were caused by the inclusion of patients with the incomplete form or other sex-reversal disorders. Moreover, our results suggest that clinicians should carefully examine patients with SRY abnormalities.

Adolescent↗
PubMedDate not supplied

Microsatellite instability in gonadal tumors of XY pure gonadal dysgenesis patients.

To investigate genetic alternation accompanied by malignant transformation in gonadal tumors of XY pure gonadal dysgenesis patients, we investigated microsatellite instability in the hMSH1, hMSH2, TP53, and DCC loci, and ras mutations in two patients. The gonadal tumors from the patients were combined gonadoblastoma and dysgerminoma. Microsatellite instability and/or loss of heterozygotes (LOH) at hMSH1, hMSH2, and TP53 were detected in the dysgerminoma lesions of the both patients, but were not observed in any normal tissues. In the analyses of the H-, K-, or N-ras genes, where specific mutations have been frequently reported, no mutations were observed in the tumors. It is suggested therefore that microsatellite instability plays an important role in malignant transformation of gonadal tumors in patients with XY pure gonadal dysgenesis.

Adolescent↗
PubMed1999

Gonadal stage-dependent effects of gonadal steroids on gonadotropin II secretion in the Atlantic croaker (Micropogonias undulatus).

Involvement of gonadal steroids in the control of gonadotropin II (GTH II) (homologous to LH) secretion was investigated in the Atlantic croaker (Micropogonias undulatus) using gonadectomy (Gx) and steroid replacement paradigms. Gonadectomy in males and females during the late gonadal recrudescence phase elicited significant increases in the gonadotropin response to stimulation by an LHRH analog (LHRHa), without altering basal GTH II secretion. Slow-release silicone elastomer implants of testosterone or estradiol significantly inhibited LHRHa-induced GTH II secretion in gonad-intact and Gx males, and in Gx females, whereas 5alpha-dihydrotestosterone, a nonaromatizable androgen, was ineffective. Pretreatment of fish with an aromatase inhibitor, 1,4, 6-androstatrien-3,17-dione, 2 days before the administration of testosterone implants, completely blocked the negative effect of testosterone on LHRHa-induced GTH II secretion in males, but only partially restored it in females. This suggests that the negative feedback of testosterone in males is primarily mediated by its conversion to estradiol at the level of the hypothalamus and/or pituitary gland, while in females the androgen may also exert a direct inhibitory effect on GTH II secretion, probably mediated via an androgen receptor. In addition, estradiol and testosterone exerted positive effects on basal and LHRHa-induced GTH II secretion during the early-recrudescence phase of the gonadal cycle. The steroids switched to a negative effect on LHRHa-induced GTH II secretion once the fish had fully developed gonads, possibly as a mechanism that prevents a precocious surge in GTH II secretion and final gamete maturation until gametogenesis is complete and the environmental conditions are appropriate for spawning.

Animals↗
PubMed1991

Role of gonadal dysgenesis in gonadoblastoma induction in 46, XY individuals. The Leuven experience in 46, XY pure gonadal dysgenesis and testicular feminization syndromes.

To stress the importance of gonadal dysgenesis in the genesis of gonadoblastoma in the presence of the Y-chromosome, the authors report their experience on 7 patients with 46, XY Pure Gonadal Dysgenesis (PGD) and 14 patients with complete or incomplete forms of Testicular Feminization (TF) syndrome. The diagnostic criteria and the clinical and pathological findings are reviewed. Four patients with PGD were found to be affected by bilateral (1 patient) or unilateral (1 patient) gonadoblastomas, and by extragonadal (1 patient) or gonadal (1 patient) dysgerminoma, whereas no gonadal tumors were encountered in testes of patients with complete (CTF) or incomplete (ITF) forms of TF, underlining the pathogenic role of the gonadal dysgenesis.

Adolescent↗
PubMed2005

Differential expression of neural and gonadal aromatase enzymatic activities in relation to gonadal development in Japanese eel, Anguilla japonica.

The objectives of the present study were to investigate the enzymatic characteristics of brain aromatase in Japanese eel, Anguilla japonica, as well as the correlations between aromatase activities in various tissues (brain regions, pituitary, and gonads) and ovarian development. Eel brain aromatase exhibited a K(m) of 75 nM and a V(max) of 1.14 fmol/min mg protein (91.5 fmol/h mg protein), indicating an enzymatic activity much lower than in other teleosts but similar to that in mammals. This supports the hypothesis of the occurrence of a single aromatase gene in eels (representative of an ancient group of teleosts, Elopomorphs), as in mammals, but unlike what is observed in more recent teleosts. Aromatase inhibitors could significantly suppress brain and pituitary aromatase activity. There was no significant sex difference in aromatase activity in the forebrain, midbrain, hindbrain, or pituitary, but there was in the gonads, where aromatase could be detected in the ovaries but not in the testes, in accordance with the role of this enzyme in ovarian differentiation. Comparison with another teleost, black porgy (Percomorph), under the same experimental conditions, further confirmed the low activity of aromatase in the eel. We investigated variations in brain, pituitary, and gonad aromatase activity in relation to ovarian development in control female eels (gonadosomatic index, GSI, 0.1-1.6%) as well as in eels treated with pituitary extract (experimental ovarian maturation; GSI up to 25%). Differential expression of neural and gonadal aromatase was observed in relation to the course of gonadal development. Pituitary aromatase activity increased with GSI at all stages. Brain (specially forebrain) aromatase activity significantly increased in early vitellogenic control eels (GSI>0.8%) and in treated eels. The low activity of eel aromatase may be related to the characteristic life cycle of the eel, in which there is a long delay of the onset of puberty before oceanic reproductive migration.

Androstenedione↗
PubMed1984

Gonadal tumors in patients with gonadal dysgenesis and sex chromosomal rings and fragments.

Patients with female phenotypes and dysgenetic gonads harboring testicular tissue have a markedly increased risk of developing gonadal tumors. Cytogenetic demonstration of Y chromatin is the currently accepted criterion for performing prophylactic gonadectomies in these women. We studied four patients with dysgenetic gonads containing either testicular tissue or germ cell tumors. All had small sex chromosomal fragments which could not be characterized by conventional cytogenetic studies. Clinical features, DNA replication studies, and immunologic assays of Xga and H-Y antigens failed to correlate consistently with the gonadal histology. We recommend prophylactic gonadectomies and subsequent hormone replacement in all patients with female phenotypes, gonadal dysgenesis, and cytogenetically indeterminate sex chromosomal fragments.

Adolescent↗
PubMed1989

Catecholamine effects on testicular testosterone production in the gonadally active and the gonadally regressed adult golden hamster.

Several lines of evidence support a role of testicular innervation and peripheral catecholamines in the control of male gonadal function, particularly before puberty. It was therefore of interest to compare the effects of catecholamines on androgen production during the periods of gonadal activity and quiescence in a seasonally breeding species. We have examined direct effects of epinephrine (EPI), norepinephrine (NE), the beta-adrenergic agonist isoproterenol (ISO), and the alpha-adrenergic agonist phenylephrine (PHE) on testicular testosterone (T) production in hamsters with gonadal regression induced by 12 wk exposure to short photoperiod (SD) and in gonadally active hamsters maintained in long photoperiod (LD). Fragments of decapsulated testes were incubated with various combinations of these catecholamines (10(-5)-10(-9) M), human chorionic gonadotropin (hCG; 3.1 mIU/ml), the beta-receptor antagonist propranolol (10(-5) M) and the alpha-l-receptor antagonist prazosin (10(-5) M), for 6 h. In the incubations of testes from LD hamsters, the accumulation of T in the medium was stimulated by hCG but not affected by either catecholamine. However, EPI, NE, and PHE at 10(-5) M, but not ISO, augmented the stimulation of T by hCG. In sharp contrast to these findings, T production by the regressed testes of SD animals was stimulated by EPI (at 10(-8)-10(-5) M), NE (at 10(-6)-10(-5) M), and PHE (at 10(-6)-10(-5) M) in a dose-related manner, but unaffected by ISO. These stimulatory effects were prevented by prazosin, but not by propranolol. Moreover, 10(-5) M of EPI, NE, and PHE augmented the stimulatory effect of hCG on T production. We conclude that the seasonal transition from gonadal activity to quiescence in the adult golden hamster is accompanied by a major increase in the responsiveness of testicular steroidogenesis to catecholamines acting via the alpha-1-adrenoreceptor and that catecholamines can modulate Leydig cell response to gonadotropins in this species. These findings could be related to up-regulation of the alpha-1-receptor in the testis of the SD animal and suggest that catecholamines may be involved in the regulation of the testis during physiological suppression of gonadotropin release and during stress.

Animals↗
PubMed1976

Gonadal calcification. Indication for gonadectomy in gonadal dysgenesis.

Germ cell tumors, including gonadoblastoma, are usually found in patients with gonadal dysgenesis who have Y chromatin in their genotype. Diffuse calcification is a common finding in gonadoblastomas. Bilateral calcifications in the gonadal sites were seen on the intravenous pyelogram of a patient with 46,XX pure gonadal dysgenesis. Although the calcification was present in the fimbria of the fallopian tube, we suggest that gonadectomy is indicated in the patient with gonadal dysgenesis and probably gonadal calcification.

Adolescent↗
PubMed1979

A patient with pure gonadal dysgenesis, gonadal tumour and virilisation.

A phenotypic female, karyotype XY presented with virilisation and amenorrhoea. The gonads showed evidence of oestrogen and testosterone production and, in view of the risk of malignancy, a laparotomy was performed. A streak gonad was present on one side with a streak gonad containing discrete tumours on the other. The uterus and Fallopian tubes were present. Removal of the gonads and uterus and subsequent oestrogen replacement therapy have produced a satisfactory clinical result.

Adult↗
PubMed1981

Production of testosterone and estrogen in vitro by gonadal tissue from a 46,XY true hermaphrodite with gonadal failure and gonadoblastoma.

A phenotypic female patients with 46,XY true hermaphroditism and clitoromegaly was found at laparotomy to have normal müllerian structures with a right streak gonad and a left dysgenetic ovotestis that contained a gonadoblastoma. Karyotypes of peripheral lymphocytes and cells from labial skin and both gonads were all 46,XY, so an unrecognized mosaic or chimera was unlikely. Tissue from both gonads was studied in vitro and estrogen and testosterone production measured. The streak produced 186.6 pg/mg/24 hr of estrogen and 78 pg/mg/24 hr of testosterone, whereas the dysgenetic ovotestis produced 85.8 pg/mg/24 hr of estrogen and 184.6 pg/mg/24 hr of testosterone (more than double the testosterone produced by the streak). Comparisons between these data and those previously published suggest that dysgenetic streak gonadal tissue is more active steroidogenically than postmenopausal ovarian stroma.

Adolescent↗
PubMed2005

Proteome analysis of chicken embryonic gonads: identification of major proteins from cultured gonadal primordial germ cells.

The domestic chicken (Gallus gallus) is an important model for research in developmental biology because its embryonic development occurs in ovo. To examine the mechanism of embryonic germ cell development, we constructed proteome map of gonadal primordial germ cells (gPGCs) from chicken embryonic gonads. Embryonic gonads were collected from 500 embryos at 6 days of incubation, and the gPGCs were cultured in vitro until colony formed. After 7-10 days in culture, gPGC colonies were separated from gonadal stroma cells (GSCs). Soluble extracts of cultured gPGCs were then fractionated by two-dimensional gel electrophoresis (pH 4-7). A number of protein spots, including those that displayed significant expression levels, were then identified by use of matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry and LC-MS/MS. Of the 89 gPGC spots examined, 50 yielded mass spectra that matched avian proteins found in on-line databases. Proteome map of this type will serve as an important reference for germ cell biology and transgenic research.

Animals↗
PubMed1991

A 46,XY female with mixed gonadal dysgenesis and a 48,XY, +7, +i(12p) chromosome pattern in a primary gonadal tumor.

Cytogenetic analysis of a primary germ-cell tumor originating from the streak gonad of a 20-year-old phenotypic female with a 46,XY karyotype and mixed gonadal dysgenesis revealed a 48,XY, +7, +i(12p) chromosomal pattern. Germ-cell tumors originating from gonads of normal males are usually highly aneuploid. An isochromosome 12p as well as an overrepresentation of chromosome 7 material are among the specific changes most consistently observed. The present case shows that tumors of dysgenetic gonads, albeit being near-diploid, may exhibit similar chromosomal changes. This observation lends additional support to the hypothesis that these specific cytogenetic anomalies may play an important role in the pathogenesis of human germ-cell tumors.

Adult↗
PubMed2005

Mutations in SRY and WT1 genes required for gonadal development are not responsible for XY partial gonadal dysgenesis.

The WT1 transcription factor regulates SRY expression during the initial steps of the sex determination process in humans, activating a gene cascade leading to testis differentiation. In addition to causing Wilms' tumor, mutations in WT1 are often responsible for urogenital defects in men, while SRY mutations are mainly related to 46,XY pure gonadal dysgenesis. In order to evaluate their role in abnormal testicular organogenesis, we screened for SRY and WT1 gene mutations in 10 children with XY partial gonadal dysgenesis, 2 of whom with a history of Wilms' tumor. The open reading frame and 360 bp of the 5' flanking sequence of the SRY gene, and the ten exons and intron boundaries of the WT1 gene were amplified by PCR of genomic DNA. Single-strand conformation polymorphism was initially used for WT1 mutation screening. Since shifts in fragment migration were only observed for intron/exon 4, the ten WT1 exons from all patients were sequenced manually. No mutations were detected in the SRY 5' untranslated region or within SRY open-reading frame sequences. WT1 sequencing revealed one missense mutation (D396N) in the ninth exon of a patient who also had Wilms' tumor. In addition, two silent point mutations were found in the first exon including one described here for the first time. Some non-coding sequence variations were detected, representing one new (IVS4+85A>G) and two already described (-7ATG T>G, IVS9-49 T>C) single nucleotide polymorphisms. Therefore, mutations in two major genes required for gonadal development, SRY and WT1, are not responsible for XY partial gonadal dysgenesis.

5' Untranslated Regions↗
PubMed1999

Morphology of gonads in pure XY gonadal dysgenesis.

The authors gathered 20 patients having Swyer's syndrome and performed a bilateral gonadectomy and carried out a pathohistologic evaluation of the streak gonads. A more frequent occurrence of streak gonad tumors was found together with the possibility of tracing the merge gonadoblastoma into dysgerminoma (the youngest patient was 15 years old). In 95% of the streak gonads checked an ovary-like stroma was found. In 11 of the patients (55%) one of the above mentioned tumors was found. A frequent finding was the presence of Leydig-type cells, calcifications and the remains of Wolffian canals. In three streak gonads, the corpora albicans-like formations were found.

Adolescent↗
PubMed1976

[Evaluation of gonadotropic and gonadal secretions in primary abnormalities of the gonads and male pseudohermaphrodism before and after the age of puberty].

Blood levels of gonadotropins (FSH and LH) and gonadal steroids (testosterone or estradiol) have been evaluated in 72 children and adolescents with primary gonadal defects (45 agonadal patients, 7 with asymetrical gonadal dysgenesis, 9 with Klinefelter syndrome, 4 with partial testicular dysgenesis and 7 with partial ovarian dysgenesis) and in 17 cases of male pseudohermaphrodism. A LH-RH test has been performed in most cases, and a testicular stimulation test with chorionic gonadotropin in patients with testicular tissue. Agonadal subjects had increased blood and pituitary releasable gonadotropins: very high in infants and young children, much less from 7 to 11 years, a high spurt being observed at 12 years. This diphasic pattern relates to the varying sensitivity of hypothalamic receptors and suggests that adrenal steroids may restrain gonadotropic secretion at 7-8 years. As a diagnostic tool, the increase of gonadotropins may be missing in the 7-11 years group. In the 1-12 years patients with partially defective gonads, blood and pituitary releasable gonadotropins and blood steroids are usually normal, but testosterone response to chorionic gonadotropin may be already blunted. From 13 years the gonadotropic secretion is usually increased, even when testosterone secretion and reserve are within normal range. Most male pseudohermaphrodites showed normal gonadotropic and testicular secretions. But four patients had highly increased responses to LH-RH, suggesting a defect of testicular secretion or of receptors, and demonstrating some heterogeneity in the male pseudohermaphrodism group.

Adolescent↗
PubMed1996

Abnormal gonadal differentiation in two subjects with ambiguous genitalia, Mullerian structures, and normally developed testes: evidence for a defect in gonadal ridge development.

Among a group of patients with abnormal sexual differentiation, we have identified two subjects who had a 46,XY karyotype, ambiguous genitalia, and well-developed Müllerian structures, but normal appearing testes. The presence of ambiguous genitalia and persistent Müllerian structures implied both Leydig cell and Sertoli cell dysfunction, hence, gonadal dysgenesis. However, the normal testicular histology suggested that the underlying abnormality was not a defect in testis determination itself but an abnormality in timing of gonadal ridge and testis development. In one of the two subjects genomic DNA was available. The sequence of the SRY gene was normal. Because rare patients with partial androgen insensitivity may have a similar phenotype, the AR gene was evaluated by denaturing gradient gel electrophoresis (DGGE) and was normal. Some subjects with mutation of the WT1 gene or with deletion of the distal short arm of chromosome 9 may have similar phenotypes. The WT1 gene was studied by single-strand conformation polymorphism (SSCP) analysis and was normal. In addition, there was no loss of heterozygosity of polymorphic markers in distal 9p. The gene for Müllerian inhibiting substance (MIS) was also studied by SSCP and was normal. Although the exact mechanism for the defect in the two subjects is unknown, it may be due to an abnormality in a gene or genes involved in the timing of gonadal ridge development.

Cell Differentiation↗