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At least 19 recordsLinked to original sources
PubMed1975

Laparoscopy in endocrine and genetic disorders of the gonads.

The guideline of this work is to examine the diagnostic value of laparoscopy in some endocrine and genetic syndromes connected with gonadal pathology or abnormal sexual development in relation to the various hormonal and cytogenetic techniques usually utilized by the endocrinologist. After a brief introduction, Chapter 1 stresses our purpose to examine the advantages and limits of laparoscopy by investigating the most significant cases that came to our observation. Attention is drawn in Chapter 2 to the application of laparoscopy in a particular form of amenorrhea (uterus absence), admittedly of great endocrinologic interest. In particular, the results obtained by the application of this technique are reported in cases of uterus agenesis and the testicular feminization syndrome. The clinical, cytogenetic and hormonologic study of one case of uterus agenesis is reported together with that of four cases of the testicular feminization syndrome with the view to discussing the differential diagnosis between these two syndromes and the particular diagnostic problems connected with the latter. Our conclusion is that laparoscopy, although usually having only a confirmatory value in these syndromes, may assume in certain cases major diagnostic importance (the post-puberal testicular feminization syndrome without palpable gonads, the pre-puberal testicular feminization syndrome, rare cases of the testicular feminization syndrome associated with chromosome aberrations). Chapter 3 discusses the application of laparoscopy in female gonadal dysgenesis on the basis of three cases of Turner's syndrome with different diagnostic problems and one of pure gonadal dysgenesis. It is stressed that, although in the majority of cases of Turner's syndrome the laparoscopic findings are quite characteristic (streak gonads), in some cases the gonads may also present the aspect of hypoplastic ovaries. This finding is observed in two cases of Turner's syndrome with XO/XX mosaicism, of which one case with spontaneous menarche. The diagnostic value of laparoscopy is discussed in the cases of pure gonadal dysgenesis and in variants of Turner's syndrome chromatin-positive with X chromosome partial monosomy and chromatin-negative with a Y chromosome. Our conclusion is that laparoscopy assumes particular diagnostic value in cases of pure gonadal dysgenesis without chromosome aberrations, because chromosome aberrations may be absent in this syndrome, as well as in chromatin-negative variants with a Y chromosome because the gonads and gonaducts differentiation may be variable.

Adolescent↗
PubMed1975

Studies of in vitro steroid metabolism by testis tissue from 'complete' and 'incomplete' forms of testicular feminization.

The in vitro steroid metabolism of testicular tissue from seven cases of testicular feminization was studied. Using radioactive steroid substrates of both C21 and C19 configurations, kinetic studies of these tissues showed that the major pathway of testosterone production was via the delta5 pathway, i.e. pregnenolone leads to 17 alpha-hydroxypregnenolone leads to dehydroepiandrosterone leads to androstenedione and androstenediol leads to testosterone, with the accumulation of dehydroepiandrosterone and androstenediol. This accumulation of dehydroepiandrosterone and androstenediol does not occur in similar incubations of normal human testis tissue. The seven cases of testicular feminization were classified as 'complete' or 'incomplete' forms of the syndrome by reference to clinical data and the histology of the testicular tissue. It was concluded that the biochemical differences between the two forms of the syndrome were the greater production and accumulation of C21 and C19 delta 4 steroids from the C21 and C19 delta 5 steroid precursors indicating the relatively greater activity of the C21-3beta-hydroxysteroid dehydrogenase-isomerase enzyme in the 'incomplete' form.

17-alpha-Hydroxypregnenolone↗
PubMed1975

Genetic and hormonal control of male sexual differentiation.

Phenotypic sexual differentiation during embryogenesis is a complex process involving the action of at least 18 genes. These genes regulate gonadal differentiation, gonadal hormone formation, and in the male the cellular action of three necessary hormones, namely mullerian regression factor, testosterone, and dihydrotestosterone. Analysis of two of the mutations affecting sexual development is consistent with the thesis that the two androgens testosterone and dihydrotestosterone have separate and specific roles in virilization of the male urogenital tract, testosterone stimulating wolffian duct development and dihydrotestosterone mediating development of the urogenital sinus and external genitalia. In the disorder familial incomplete male pseudohermphroditism, type 2, deficient dihydrotestosterone formation is associated with a selective failure of virilization of the urogenital sinus and external genitalia, whereas the wolffian duct derivatives develop normally. On the other hand, in the testicular feminization syndrome there is a complete failure in the development of the male phenotype, indicating that the primary defect involves an abnormality in some biochemical step that is common to the action of both androgens. Evidence from studies in the submandibular gland of the mouse with testicular feminization suggest that the fundamental defect lies in the translocation and/or nuclear binding of the cytoplasmic androgen receptor. It remains to be proven whether these events in the postnatal, sexually dimorphic submandibular gland of the testicular feminization mouse reflect prenatal events occurring in the urogenital tissues during embryogenesis.

Age Factors↗
PubMed1975

Testicular androgen binding protein (ABP) - a parameter of Sertoli cell secretory function.

Using ABP as an index of Sertoli cell secretory function, several important features of the Sertoli cell have emerged: 1. The stimulation of ABP production by FSH clearly points to the Sertoli cell as a target cell for FSH (3,4,9-16,21,24). 2. The dramatic effects of androgens on ABP production both in immature and mature rats also suggest that the Sertoli cell is a target cell for androgen (3,12,14,16,25). 3. The striking reduction in ABP production in the cryptorchid testis raises the question whether impairment of Sertoli cell function is the primary reason for the loss of germ cells that occurs in this condition (20). 4. Drugs like nitrofurazone or ethionine, or X-irradiation only slightly affect the secretory function of the Sertoli cells (ABP production), indicating that these treatments most probably have direct effects on the germ cells as well. Thus, measurement of ABP production rate is a very important tool in order to evaluate how hormones, drugs and physical injuries might affect the secretory function of the Sertoli cell. This test system might be of great use in order to study the physiology and hormonal regulation of the Sertoli cells. It might also be valuable in pharmacological and toxicological studies.

Age Factors↗
PubMed1978

Effect of the mouse mutants testicular feminization and sex reversal on hormone-mediated induction and repression of enzymes.

The mouse mutants testicular feminization and sex reversal have been used to investigate hormone-mediated induction and repression of enzymes. Tfm/Y animals were already known to be androgen insensitive, rendering the androgen-inducible enzymes ADH and beta-glucuronidase noninducible because of an inherited deficiency of a cytosol androgen-receptor complex. The animals display female secondary sexual characteristics. Sxr/+,XX animals display male primary and secondary sexual characteristics with small testes. We demonstrate (1) that the Tfm mutation is pleiotropic, preventing repression of an androgen-repressible enzyme (ornithine aminotransferase) as well as induction of androgen-inducible enzymes, (2) that an estrogen-inducible enzyme (histidine decarboxylase) is not affected by the Tfm mutation, and (3) that Sxr/+,XX animals produce enough androgen for malelike activities of androgen-sensitive enzymes. It was also discovered that histidine decarboxylase repressed by androgen in normal animals, rather than being unaffected by it in Tfm/Y animals, is in fact induced. This unexpected phenomenon is discussed and an explanation is suggested for it.

Alcohol Oxidoreductases↗
PubMed1977

Mullerian inhibiting substance in human testes after birth.

Tiny testicular biopsies from humans were assayed for Mullerian inhibiting Substances using a graded organ culture technique. Mullerian Inhibiting Substance activity was high during the first year of life, declined during the second year of life, and then disappeared. Mullerian Inhibiting Substance activity is lower in boys with undescended testis than in children with normal or intersex testes at comparable ages under two years. It is possible that Mullerian Inhibiting Substance affects testicular descent as well as causing Mullerian duct regression.

Adolescent↗
PubMed1976

Studies in a phenotypic female with 17-alpha-hydroxylase deficiency.

In a 19-year-old phenotypic female (46, XY) with hypertension and hypokalemia, studies confirmed 17-alpha-hydroxylase deficiency. Prior to diagnosis she had been considered to have testicular feminization. Increased plasma progesterone and urinary pregnanediol levels were present before treatment. Increased secretion rates of deoxycorticosterone and corticosterone and abnormally low production of cortisol and aldosterone were present. Following treatment with hydrocortisone, plasma progesterone, serum potassium, and urinary pregnanediol levels and DOC and B secretions were normal. Aldosterone secretion six months after treatment remained low. Normal blood pressure measurements were achieved during treatment with hydrocortisone and oral estrogen with the patient at rest; however, mild elevations in blood pressure (130/90 mm Hg) have been noted despite continued hydrocortisone therapy.

Adult↗
PubMed1976

Androgen insensitivity in man: evidence for genetic heterogeneity.

We have studied ten phenotypically similar patients with complete androgen insensitivity. All of the patients tested had significantly elevated serum luteinizing hormone and plasma androgens within or above the normal adult male range. On the basis of specific dihydrotestosterone binding by skin fibroblasts, we identified two subgroups. Six patients from five different families had undetectable dihydrotestosterone binding, while four patients from two families had normal binding activity. Our results indicate that within the clinical syndrome of androgen insensitivity there are at least two distinct genetic variants. These variants may result from allelic mutations of the same X-linked gene specifying the dihydrotestosterone receptor or, alternatively, from mutations of separate genes both being essential for androgen action in responsive cells.

Androgen-Insensitivity Syndrome↗
PubMed1976

Male pseudohermaphroditism presumably due to target organ unresponsiveness to androgens. Deficient 5alpha-dihydrotestosterone binding in cultured skin fibroblasts.

Maximum specific 5alpha-dihydrotestosterone (DHT) binding activity (Bmax) had been measured in intact confluent monolayers representing fibroblast strains derived form nongenital and genital (labium majus) skin of normal individuals and of 11 patients fulfilling the clinicogenetic criteria of complete testicular feminization (TF). Nine labium majus strains from adult females had a mean Bmax value three times greater than that of seven nongenital strains from adult females (33 vs. 11 fmol/mg cell protein). The Bmax results for 13 adult nongenital strains varied from 5.6 to 23.3 fmol/mg protein; the values for males and females had very similar means and ranges. The variation could not be correlated with the chronologic age of adult skin explant donors or with the in vitro age (mean population doubling level) of the cultures assayed. The Bmax activities of three nongenital strains from normal infants (two male, one female) did not exceed 5 fmol/mg protein. Seven of eight nongenital TF strains had Bmax values below 2 fmol/mg protein; the value for the eighth coincided with the lower limit of normal adults. The lower limit of DHT binding in normal labium majus strains was 15 fmol/mg protein. Three of five labial strains from patients with TF had Bmax values close to zero; the other two fell between 10 and 15 fmol/mg protein. It is apparant that labial skin fibroblast strains from clinically homogeneous patients with TF had highly variable degrees of DHT binding deficiency, and that they permit a more reliable diagnosis of severe and intermediate degrees of DHT binding deficiency than do strains of nongenital skin fibroblasts.

Adolescent↗
PubMed2024

Diverse phenotypes and fertility outcomes of patients with androgen insensitivity syndrome in a Chinese family harboring identical AR gene variant.

BACKGROUND: Androgen insensitivity syndrome (AIS) is a rare genetic disorder characterized by resistance to androgens, mainly due to mutations in the androgen receptor (AR) gene. It can manifest as complete AIS, partial AIS and mild AIS. While there have been studies linking specific AR gene mutations to AIS phenotypes, different clinical AIS phenotypes are also reported in patients with the same AR gene mutation. So far, the precise correlations between phenotypes and genotypes remain incompletely understood. METHODS: We conducted a thorough investigation involving four patients diagnosed with different types of AIS from a single Chinese family. Clinical manifestations, laboratory examinations, and fertility outcomes were well-documented. Furthermore, we performed genetic sequencing to detect possible pathogenetic variants. RESULTS: Whole exome sequencing identified a hemizygous missense variant (c.2263T > C; p.Phe755Leu) of AR gene in all four affected patients with different degrees of undermasculinisation and heterogeneous spermatogenesis. The proband, diagnosed with partial AIS, opted for treatment with donated sperm due to non-obstructive azoospermia, while their older sibling, diagnosed with complete AIS, was raised as a girl. His two maternal uncles were both diagnosed with mild AIS, the older uncle fathered two girls naturally, whereas the younger uncle utilized assisted reproductive technology to conceive a boy because of severe oligoasthenozoospermia. CONCLUSION: Our study first identified the same AR variant (c.2263T > C;p.Phe755Leu) in four affected patients displaying highly diverse phenotypes of AIS and fertility outcomes, thereby significantly expanding the phenotypic spectrum of AIS. Notably, we presented a clear insight into different fertility outcomes of AIS patients with identical AR (c.2263T > C;p.Phe755Leu) variant, which provided reliable evidence that males harboring this variant may obtain biological offspring naturally or in combination with assisted reproductive technology. Furthermore, our study underscored the potential role of androgen concentration in shaping the phenotypic diversity of AIS, warranting further investigation.

Adult↗