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Biomedical subjects

V Amice

Publications and source records attributed to V Amice.

10 recordsLinked to original sources

Sex chromosome mosaicism in couples undergoing intracytoplasmic sperm injection.

BACKGROUND: Several studies have shown an increased frequency of constitutional chromosome aberrations in male and female partners of couples examined prior to ICSI. We conducted a cohort study to determine whether there was an increase in numerical sex chromosome mosaicism among couples undergoing ICSI compared with fertile couples. METHODS: Cytogenetic investigations were performed in 228 females and 208 males seen for ICSI between January 1997 and March 2001. They were matched to control females and males. RESULTS: Sex chromosome loss or gain was observed in at least one cell from 24.1% of ICSI women in comparison with 22% of controls (not significant). A significant difference between these two groups was found when X chromosome loss in at least two cells was considered, 9.6% for ICSI females versus 4.8% for controls (P = 0.01). No significant difference was observed between male groups concerning loss or gain of the X or Y chromosome. CONCLUSION: Our results support previously published studies indicating that the loss of an X chromosome in a single cell in females undergoing ICSI is probably an artefact. However, they suggest that a woman could have true sex chromosome mosaicism when two 45,X0 cells are found.

Adult↗

[Serologically detected HY antigen and its regulation].

The serologically detected, male predominant s HY Ag is a surface glycoprotein. The structural gene would be located on the 6th chromosome and regulated by gonosomal genes. The presence of testes (or testicular remenants) is linked to the s HY antigen expression in most abnormalities of sexual differentiation. However, the basal s HY Ag value is sometimes increased in the absence of any testicular tissue, as in virilized females (21-hydroxylase deficiency, idiopathic or ovarian hirsutism). Homogametic sex s HY Ag may increase to heterogametic sex values under the action of androgens in mammals and that of oestrogens in birds.

Female↗

Increase in H-Y antigen-positive lymphocytes in hirsute women: effects of cyproterone acetate and estradiol treatment.

To investigate a possible relationship between lymphocyte H-Y antigen expression and plasma androgen concentrations in hirsute women, 27 hirsute women were studied. A significant increase in the percentage of H-Y-positive lymphocytes was found in both hirsute women with idiopathic hirsutism [13.4 +/- 2.9% (+/- SD); n = 15] and hirsute women with the polycystic ovary syndrome (13.0 +/- 2.8%; n = 12) compared to that in normal women (10.0 +/- 1.9%; n = 30; P less than 0.0005). Plasma testosterone and androstenedione concentrations, % H-Y+ lymphocytes, and hirsutism scores diminished during oral cyproterone acetate (50 mg/day) and percutaneous estradiol (3 mg/day) treatment. Significant correlations between % H-Y+ lymphocytes and hirsutism scores (P less than 0.001), % H-Y+ lymphocytes and plasma T concentrations (P less than 0.01) were found. We conclude that 1) women can produce H-Y antigen in the same way as men; 2) hirsutism is associated with an increase in H-Y antigen; and 3) the antiandrogen cyproterone acetate reduces H-Y antigen expression on lymphocytes.

Adult↗

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↗

Increase of lymphocytic H-Y antigen in female 21-hydroxylase deficiency.

H-Y antigen was found to be increased in lymphocytes from 10 female 21-hydroxylase deficiencies, suggesting a correlation between the degree of virilization of these patients and their H-Y + lymphocytes proportions. Furthermore, these findings demonstrate the ability of a 46,XX female subject to produce, in some circumstances, an excess of H-Y antigen.

Adrenal Hyperplasia, Congenital↗

[Y-chromosome polysomy and expression of the H-Y antigen].

The sex-differentiation H-Y antigen was studied in 5 males subjects with Y-chromosome polysomy. All had gonadal deficiency and significant decrease of H-Y antigen as compared with 77 normal 46, XY male controls. Men with additional Y-gonosomes may be hypogonadic or, more often, fertile, as was probably the case with the 3 patients with very high H-Y antigen titers previously described by other research workers. The phenotypic polymorphism of these subjects therefore seems to be parallel with their H-Y antigen polymorphism and there may be, in our 5 subjects, a relationship between abnormal spermatogenesis and H-Y antigen deficiency.

Adult↗

Allogeneic responses in vitro induced by fetomaternal alloimmunization.

The present study was undertaken in order to determine what type(s) of pregnancy-induced allogeneic reaction could alter MLC (mixed lymphocyte culture) reactivity in routine HLA-D typing of lymphocytes in multiparous women (MW) possessing antibodies against paternal HLA-DR antigens. Unresponsiveness to homozygous typing cells (HTC) representing a paternal and probably fetal HLA-DR determinant was frequently observed. Kinetics experiments ruled out an early secondary proliferative response to HTC representing the paternal HLA-D determinant, which would be missed in a classical long-term mixed lymphocyte culture. Direct cytotoxicity against paternal or panel target cells was not always associated with inhibition of proliferative response to the same stimulator cell. Specific anti-HLA-DR blocking activity (antibodies?) in the supernates of restimulation reactions of lymphocytes from MW could be responsible for this inhibitory effect. Moreover, the study points to the existence of suppressor cells in the immunized MW acting independently of specific restimulation. The in vitro suppression appeared to be selective, restricted to cells sharing HLA-D linked structures with the suppressor cells, and suggests that auto-regulator mechanisms could be induced in pregnancy in order to modulate antibody production.

Antibodies↗