Publications by authors named "SULTAN C"

Background: The androgen sensitivity test used in male pseudohermaphroditism for clinical assessment of the androgen sensitivity and prediction of penile development is an important element in choice of gender. However, there is a wide range of testosterone dosage and no standardized test.

Methods And Patients: Two doses (2.

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Finasteride is a potent 5 alpha-reductase inhibitor which has proven useful in the clinical management of benign prostatic hyperplasia. To determine a potential mode of action for finasteride in prostatic cell proliferation, we have studied the incorporation of [3H]-thymidine into the DNA of cultured epithelial and stromal cells from normal and hyperplastic human prostates. The effects of short treatment with 10(-9) M and 10(-6) M finasteride (48 hrs.

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Androgen activity in the central nervous system, as in other tissues, is mediated by the androgen receptor. We performed the precise localization of the androgen receptor in spinal cord of male and female adult rats by immunohistochemistry using polyclonal antibodies. Light microscopy indicated immunoreactivity in the anterior horn with a strong staining in motoneurons, but staining was also observed in the posterior horn.

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A wide spectrum of androgen receptor (AR) gene mutations has been reported in complete androgen insensitivity syndromes. The molecular basis of androgen resistance was investigated in a female newborn with complete testicular feminization. Sequencing identified a point mutation in exon 4 responsible for a leucine (CTG) to arginine (CGG) replacement at codon 707.

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In two families with complete androgen insensitivity, we have identified naturally occurring point mutations in the human androgen receptor gene that encode amino acid substitutions within the DNA-binding domain. The two amino acid substitutions, a valine to phenylalanine and a leucine to proline, occur at positions 581 and 616, respectively, of the androgen receptor. The mutations were recreated by site-directed mutagenesis.

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Benign prostatic hyperplasia (BPH) is the most common benign proliferative disorder of unknown etiology found in men. Because insulin-like growth factors (IGFs) with their binding proteins (IGFBPs) are involved in the control of cellular proliferation, differentiation, and metabolism, we compared their secretion by prostatic epithelial and stromal cells in primary culture from the four different zones of normal prostate and from hyperplastic tissue to assess their contributions to the hyperplastic development. IGF-I could not be detected in the conditioned medium from either epithelial or stromal cells from normal and BPH tissues.

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Benign prostatic hyperplasia (BPH) is the most common benign proliferative disorder of unknown etiology found in men. Dysregulation of testosterone conversion to dihydrotestosterone (DHT) by 5 alpha-reductase has been described as a key step in the development of BPH. We investigated the 5 alpha-reductase activity in primary cultures of epithelial and stromal cells from the four different regions (periurethral, transition, central and peripheral zones) of normal and hyperplastic human prostates.

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Unlabelled: The molecular basis for male pseudohermaphroditism produced by the 5 alpha-reductase deficiency is becoming increasingly understood.

Objective: We have performed biochemical and molecular analyses of the 5 alpha-reductase type 2 gene in a Turkish family with a 5 alpha-reductase deficiency.

Patient: A 46,XY prepubertal Turkish patient with female phenotype showing clitoral hypertrophy, high plasma testosterone and dihydrotestosterone, and normally differentiated and developed testosterone-dependent internal genitalia.

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The molecular basis of 5 alpha-reductase (5 alpha R) deficiency was investigated in four patients from three European families. In the French family, the first patient was raised as a female, and gonadectomy was performed before puberty. The second sibling, also raised as female, differed in that gonadal removal was performed after the onset of pubertal masculinization.

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We studied the androgen receptor gene in a large kindred with complete androgen insensitivity syndrome and negative receptor-binding activity, single-strand conformation polymorphism (SSCP) analysis and sequencing identified a 13 base pair deletion within exon 4. This was responsible for a predictive frameshift in the open reading frame and introduction of a premature stop codon at position 783 instead of 919. The deletion was reproduced in androgen receptor wildtype cDNA and transfected into mammalian cells.

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The various processes involved in sexual differentiation have been considerably clarified over the last few years through advances in biochemistry and molecular genetics. The cloning of the gene responsible for testicular determination SRY, of the anti-Müllerian hormone and anti-Müllerian hormone receptor genes, of the several steroidogenic enzymes genes, of the 5 alpha-reductase type 2 gene and of the androgen receptor gene has permitted to elucidate the molecular defects causing abnormal sexual differentiation. These data have brought a substantial impact on the understanding of human male sexual differentiation and its main disorders.

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We studied the effect of testosterone on the growth of a 20- methylcholanthrene-induced transplanted fibrosarcoma and assayed androgen receptors in this tumor. The effect of an antiandrogen in male rats and the comparative tumor growth in females confirmed the androgen sensitivity. A synthetic androgen that strongly binds to the androgen receptor was used to characterize the binding activity in nuclear extracts of tumor.

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We have reviewed our experience with four of the entities that are included under the generic term chronic myeloid leukaemia (CML), namely the classic Ph+ CGL, both BCR+ and BCR-, aCML and CMML. We have developed a statistical model that confirms that CGL, aCML and CMML can be distinguished from each other with reasonable success employing five quantitative parameters (WBC, percentage immature granulocytes, percentage monocytes, percentage basophils, percentage erythroid precursors in bone marrow) and one qualitative parameter (granulocytic dysplasia). It is hoped that these detailed recommendations will enable investigators to improve their diagnostic accuracy.

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The androgen receptor belongs to the family of nuclear receptors and contains three functional domains: a carboxy-terminal hormone binding region, a central cystein rich DNA binding region and an amino-terminal region involved in the expression of androgen regulated genes. Cloning of the complementary DNA encoding the androgen receptor enabled the characterization of the molecular defects associated with androgen insensitivity syndromes, X-linked disorders resulting from androgen action defects in target cells. Moreover, androgen receptor gene alterations have been recently described in two unrelated diseases: male breast cancer and spinal and bulbar muscular atrophy.

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In a large family with Reifenstein syndrome, we previously performed molecular analysis of the androgen receptor gene. Direct sequencing showed a G-A point mutation at position 2818 of exon 7, which was responsible for an arginine-histidine substitution at position 840 of the androgen receptor. In this family, the proband's mother became pregnant and wished to know whether she was carrying an unaffected fetus.

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The development of high-grade non-Hodgkin's lymphomas in HIV-positive patients and patients with acquired immune deficiency syndrome (AIDS) is a well known phenomenon. The proper classification of these neoplasms often requires a multiparameter approach, including the interpretation of a large panel of immunologic markers analyzed by flow cytometry. The availability of individuals with the required expertise to properly interpret these marker studies is limited.

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In understanding Turner's syndrome, spontaneous adult height is a prerequisite for an accurate assessment of the therapeutic efficiency of growth hormone treatment. The heights described in the literature reveal significant differences (136-147 cm). Our collaborative study pooled results from 16 pediatric endocrinology centers and obtained a large number of spontaneous adult heights (n = 216).

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Objective: Partial androgen insensitivity syndromes are the cause of genital ambiguity that is at times quite severe; there is, therefore, a high demand for prenatal diagnosis in families already afflicted with this syndrome. When the mutation has not been identified, the diagnosis can be made by the study of the polymorphisms of the androgen receptor gene. To perform molecular prenatal diagnosis in a family with partial androgen insensitivity syndrome, we studied the Hind III polymorphism of the androgen receptor gene on the trophoblastic DNA.

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Turner syndrome is a complex human phenotype most commonly seen in association with a 45,X karyotype and it has been proposed that the phenotype is the result of monosomy for genes common to the X and Y chromosomes. Detection of unrecognized Y derived material is now possible by PCR of the SRY gene. Its presence is correlated with the presence of testicular tissue, known to increase the risk of developing gonadal neoplasia.

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We screened thirteen male breast cancers for the presence of germline mutations in exons 2 and 3 encoding the DNA-binding domain of the androgen receptor. These two exons were amplified from genomic DNA extracted from patients' white blood cells. In one of these thirteen patients, single strand conformation polymorphism and direct sequencing detected a guanine-adenine point mutation at nucleotide 2185 that changes Arg608 into Lys in a highly conserved region of the second zinc finger of the androgen receptor.

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The androgen receptor belongs to the family of steroid-thyroid hormone-retinoid nuclear receptors. It contains 3 major domains: a hormone-binding region, a DNA-binding region and an amino-terminal region. Cloning of the cDNA encoding the androgen receptor and elucidation of the androgen receptor gene structure enabled the characterization of the molecular defects associated with androgen insensitivity.

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Objective: To study the androgen receptor gene in a large kindred with complete androgen insensitivity syndrome and positive receptor-binding activity.

Design: Enzymatic amplification coupled with single strand conformation polymorphism and DNA sequencing were used.

Results: In all the affected members, single strand conformation polymorphism showed a mobility shift in exon 2, suggesting a sequence alteration.

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Familial isolated growth hormone deficiency (IGHD) has been associated with complete deletions of the hGH-N gene encoding the pituitary growth hormone (GH) in a large number of cases. However, there is still no alternative empirical explanation for the remaining familial or non-familial IGHD cases. We studied a large kindred including five IGHD-affected first cousins to determine possible IGHD inheritance and whether the hGH-N gene was the cause of IGHD in this pedigree.

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