Publications by authors named "Nazareth Loreti"

Article Synopsis
  • Variations in the carbohydrate structure of follicle-stimulating hormone (FSH) significantly influence the behavior and function of Sertoli cells during sexual maturation, which is crucial for male reproductive health.
  • The study examined how different forms of recombinant human FSH (rhFSH) affect the production of inhibin, particularly how the oligosaccharide structure interacts with other gonadal factors during Sertoli cell development stages.
  • Results showed that less acidic rhFSH variants were most effective in stimulating inhibin production, with more mature Sertoli cells responding positively to all rhFSH forms, highlighting the importance of FSH glycosylation in male gonadal function.
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Background: Combined pituitary hormone deficiency (CPHD) presents a wide spectrum of pituitary gland disorders. The postnatal gonadotropic surge provides a useful period to explore the gonadotropic axis for assessing the presence of congenital hypogonadotropic hypogonadism (CHH).

Aim: To explore the functioning of the hypothalamic-pituitary-gonadal axis in the postnatal gonadotropic surge for an early diagnosis of CHH in newborns or infants suspected of having CPHD.

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In early fetal development, the testis secretes - independent of pituitary gonadotropins - androgens and anti-Müllerian hormone (AMH) that are essential for male sex differentiation. In the second half of fetal life, the hypothalamic-pituitary axis gains control of testicular hormone secretion. Follicle-stimulating hormone (FSH) controls Sertoli cell proliferation, responsible for testis volume increase and AMH and inhibin B secretion, whereas luteinizing hormone (LH) regulates Leydig cell androgen and INSL3 secretion, involved in the growth and trophism of male external genitalia and in testis descent.

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Aim: Conflicting results regarding testicular function in adults with type 1 diabetes (T1D) have been reported, but little is known about Leydig and Sertoli cell function during puberty in boys treated with multiple daily insulin doses. Our aim was to assess testicular function in boys with T1D.

Methods: Pubertal boys with T1D (n = 71) and healthy control boys (Control group; n = 104) who were 10-18 years were studied.

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The aim of this study was to analyse the biological response to different recombinant human FSH (rhFSH) glycosylation variants on the endocrine activity and gene expression at whole-genome scale in human granulosa-like tumor cell line, KGN. The effects of differences in rhFSH sialylation and oligosaccharide complexity were determined on steroid hormone and inhibin production. A microarray approach was used to explore gene expression patterns induced by rhFSH glycosylation variants.

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Granulosa cell (GC) inhibin A and B production is regulated by FSH and gonadal factors. This gonadotrophin is released as a mixture of glycoforms, which induce different biological responses in vivo and in vitro. Our aim was to determine the effect of recombinant human FSH (rhFSH) glycosylation variants on inhibin A and B production by rat GCs.

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During childhood, the pituitary-testicular axis is partially dormant: testosterone secretion decreases following a drop in luteinising hormone levels; follicle-stimulating hormone (FSH) levels also go down. Conversely, Sertoli cells are most active, as revealed by the circulating levels of anti-Müllerian hormone (AMH) and inhibin B. Therefore, hypogonadism can best be evidenced, without stimulation tests, if Sertoli cell function is assessed.

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Context: The biphasic ontogeny of serum gonadotrophins observed in normal children also exists in girls with gonadal dysgenesis, although with higher levels. However, limited data exist in prepubertal boys with anorchia.

Objective: To investigate whether the existence of testicular tissue is required for gonadotrophin downregulation in boys.

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The aim of the present study was to determine the endocrine activity of cultured early antral follicles (EAF) isolated from prepubertal diethylstilbestrol-treated rats. The effect of steroidogenic substrates and FSH on steroid, inhibin A and B, Pro-alphaC and activin A production was evaluated. Androsterone was the predominant steroid produced by EAF.

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Background: FSH is synthesized and secreted in multiple glycosylation variants with different oligosaccharide structures; the endocrine milieu regulates the composition of FSH carbohydrate moiety.

Objectives: To characterize serum FSH isoforms according to their sialic acid content and oligosaccharide complexity in regularly menstruating women and in depot medroxyprogesterone acetate (DMPA) users during the menopausal transition. Subjects and methods Ten regularly menstruating perimenopausal women aged 45-52, with mid-follicular phase FSH levels < or =10 IU/l and 10 regularly menstruating women, aged 20-39, were included.

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