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Biomedical subjects

R Virdis

Publications and source records attributed to R Virdis.

At least 55 records · Page 3Linked to original sources

Blood pressure behaviour and control in Turner syndrome.

UNLABELLED: Adult Turner syndrome (TS) patients frequently present hypertension. To clarify the pathogenesis of this hypertension we examined the blood pressure (BP) behaviour and the renin-angiotensin-aldosterone system in 31 TS patients (2-22 years of age). BP levels were occasionally elevated in 47% of the subjects and constantly elevated in 23%. Most of the patients were on estrogen replacement therapy, but 26% of them presented with elevated levels since childhood. Supine and upright plasma renin activity (PRA) values were higher in TS compared to controls and more elevated in hypertensive TS than in the normotensive ones. At Captopril challenge TS showed different PRA responses regardless of the karyotype and clinical features. Patients on estrogen therapy, however, exhibited higher increments of PRA after Captopril. CONCLUSIONS: TS patients show high frequency of hypertension in pediatric age. Estrogen therapy is an outbreaking and worsening factor. An estrogen independent role of the renin-angiotensin-aldosterone system in the pathogenesis of TS hypertension is still uncertain.

Adolescent↗

Precocious puberty in a male with Prader-Labhart-Willi syndrome.

True precocious puberty is reported in a male child with Prader-Labhart-Willi syndrome. The diagnosis of precocious puberty was made at 8 6/12 years of age when a spontaneous migration of previously unpalpable testes (mean volume = 5 ml), an increase in penis length (from 2 to 6 cm) and a growth spurt (8.4 cm/year) occurred. The follow-up until 13 years of age (bone age 15 years) showed a progressive pubertal development, facial acne (10 years), frequent spontaneous erections and ejaculations (11 years). Repeated endocrine and neuroradiological investigations were consistent with an idiopathic form of precocious puberty.

Adolescent↗

"De Novo" trisomy 20p with macroorchidism in a prepuberal boy.

A 9-year-old prepuberal boy with trisomy 20p syndrome and previously undescribed macroorchidism is presented. This is the second report of trisomy 20p originated "de novo" supporting a frequency rate of about the 10% for this etiological mechanism. Reviewing the most common clinical findings of all 19 previous patients, a typical phenotype with a recognizable face can be carried out in several cases. If prepuberal macroorchidism is confirmed in further patients, trisomy 20p could be taken into account in the differential diagnosis with the sex-linked syndromes with mental retardation and abnormal testicular increase.

Abnormalities, Multiple↗

Congenital adrenal hypoplasia: two new cases.

Two male adolescents with the X-linked form of congenital adrenal hypoplasia are described. Both grew slowly during childhood and adolescence and did not undergo pubertal development because of hypogonadotropic hypogonadism associated with the congenital adrenal hypoplasia. The severely delayed bone age in childhood is probably due to the adrenal androgen deficiency and suggests a role of these hormones in the prepubertal skeletal maturation. The failure of gonadotropin secretion still remains unexplained. A hypothalamic defect has been suggested, but further studies are necessary to clarify this hypothesis.

Adolescent↗

[Unilateral monorchidism and cryptorchism. Clinical and biological findings useful in the differential diagnosis].

Eighteen prepuberal children with only one testis palpable in the scrotum were studied in order to review the clinical and endocrinological data useful for differentiating monorchidism from unilateral cryptorchidism. Compensatory testicular hypertrophy, high LH and FSH response to LH-RH (100 micrograms/1.73 m2) and well preserved Leydig cell function after HCG (5,000 IU/m2) should lead to the diagnosis of monorchidism, either both congenital or secondary to severe atrophy of the unpalpable testis. When these findings are lacking the diagnosis of unilateral cryptorchidism should be considered.

Child↗

HLA genotypes and HLA-linked genetic markers in Italian patients with classical 21-hydroxylase deficiency.

HLA genotype and HLA-linked marker data for 40 unrelated patients from central Italy and 2 unrelated patients from Sardinia with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21-OH-def) were analyzed. The results confirm that the HLA-linked 21-OH-def gene is associated with several different HLA determinants and complete HLA haplotypes, although the only determinant with significantly increased frequency was the complement C2 allele C2B. The HLA antigens B8 and DR3 were found in significantly decreased frequencies. The haplotype A3, Cw6, Bw47, BfF, DR7, which is exceptionally rare in the general population but which has been found in many other 21-OH-def patients from diverse geographical origins, was also found in one of the Italian patients. This and other HLA haplotype associations found among the Italian patients may represent mutations that have occurred on HLA haplotypes with genetic linkage disequilibrium or, alternatively, may represent mutations that have not yet had time to become randomly associated with different HLA complex determinants. The marked negative associations with B8 and DR3 could, however, result from an interaction between the gene products of the HLA complex and the 21-OH-def phenotype.

Adrenal Hyperplasia, Congenital↗

Genetic and hormonal characterization of cryptic 21-hydroxylase deficiency.

Cryptic 21-hydroxylase deficiency has been previously described in asymptomatic family members of patients with classical congenital adrenal hyperplasia (CAH). These family members were detected by high baseline 17-hydroxyprogesterone levels found in the course of family studies. The hormonal responses to ACTH of the family members with cryptic 21-hydroxylase deficiency were determined and compared to the responses of patients with CAH, patients with acquired adrenal hyperplasia, family members predicted to be heterozygous for CAH, family members predicted to be unaffected, and the general population. The ACTH-stimulated levels of 17-hydroxyprogesterone and delta 4-androstenedione in the cryptic family members were elevated above the level of the general population or family members heterozygous for classical CAH, but below that of patients with CAH. The hormonal profile of patients with cryptic 21-hydroxylase deficiency is similar to that of patients with acquired adrenal hyperplasia. The response of family members heterozygous for the cryptic gene (21-OH CRYPTIC/21-OH NORMAL) was indistinguishable from that of family members heterozygous for the classical CAH gene (21-OH CAH/21-OH NORMAL). These studies support our previous proposal that patients with cryptic 21-hydroxylase deficiency are genetic compounds, having one gene for a severe enzyme deficiency and one gene for a mild 21-hydroxylase deficiency. Thus, the 21-hydroxylase genotype in cryptic 21-hydroxylase deficiency is 21-OH CAH/21-OH CRYPTIC.

Adolescent↗

Cryptic 21-hydroxylase deficiency in families of patients with classical congenital adrenal hyperplasia.

Serum androgens and 17-hydroxyprogesterone concentrations and HLA genotypes were determined in 124 families of patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH). In 8 pedigrees, we discovered 16 pubertal or postpubertal family members of either sex who had biochemical evidence of 21-hydroxylase deficiency but were without clinical symptoms of excess virilism, amenorrhea, or infertility. We designated these family members as individuals with cryptic 21-hydroxylase deficiency. Within each generation, the family members with cryptic 21-hydroxylase deficiency were HLA identical. It is proposed that these family members are genetic compounds, having 21-hydroxylase deficiency as a result of two recessive gene defects: 1) a severe 21-hydroxylase gene defect present in the index case with classical CAH (21-OHCAH) and 2) a mild 21-hydroxylase gene defect (21-OHCRYPTIC). Thus, the CAH genotype in the family members with cryptic 21-hydroxylase deficiency is 21-OHCAH/21-OHCRYPTIC. Lod score analysis for linkage between the cryptogenic 21-OH trait and HLA gave a combined Lod score for males and females of theta = 0.00 of 3.409. Close genetic linkage between HLA and 21-OHCRYPTIC was thus established. This study provides support for the previously reported heterogeneity of 21-hydroxylase deficiency which may result from allelic variability at the locus for steroid 21-hydroxylase.

17-alpha-Hydroxypregnenolone↗

Effects of human growth hormone on blood polyamines in hypopituitarism.

Blood levels of polyamines were evaluated in hypopituitary patients after i.m. injection of human growth hormone (hGH). After hGH administration polyamine concentration increased significantly in the first 60 minutes. The concentration of spermidine and spermine increases more in patients previously untreated or treated intermittently with hGH than in patients under continuous treatment. The results suggest that in human as well as in experimental models, polyamines could be involved in the growth process and that hGH probably stimulates polyamine synthesis.

Adolescent↗

[Evaluation of the pituitary reserve of gonadotropins and seminal function of the testis in subjects operated for cryptorchism].

76 patients (prepuberal, puberal and adults) who had undergone surgery for monolateral (35) or bilateral (41) cryptorchidism in childhood were studied. Testicular volume (76 cases), seminiferal function (18 cases) and pituitary gonadotropin reserve (51 cases) were evaluated. We obtained the following results: 1) the prepuberal patients had a normal testicular volume, while 70% of the puberal and adult patients had a mean testicular volume below normal levels. 2) 55.6% of the adults who underwent spermiogram had a pathological seminiferal function. 3) The number of patients whith exagerated gonadotropin response to GnRH-test increases with increasing puberal stage and reaches its highest significance after complete puberal development. These data confirm that: 1) the long permanence of one or both testis out of their natural position has a negative influence on their trophism; 2) the long-term prognosis of the tubular function of the testis after orchidopessis is poor in a high percentage of cases. 3) the endocrine anomalies which follow the early morphologic and functional changes of the cryptorchid testis are more easily detected during puberty as a reduced hypothalamic feedback of the gonadotropin secretion.

Adolescent↗

Endocrine studies in a pubertal male pseudohermaphrodite with 17-ketosteroid reductase deficiency.

UNLABELLED: A 12 year old child (46,XY) with 17-ketosteroid reductase deficiency was investigated. The patient, reared as a female, was first noted to have clitoromegaly at 10 years of age. Increased facial hair, deepening of the voice, acne, increased body hair and minimal breast development were noted at 12 years. delta4-Androstenedione (delta4) in peripheral blood was markedly elevated (1913 ng/100 ml) whereas testosterone (T) was in the male range of Tanner III puberty (240 ng/100 ml). Thus, delta4/T in this patient was 9.4, compared to a normal ration of 0.15 to 0.25. T/DHT was normal (10.5). Oestrone (Oe1) level was slightly elevated (6 ng/100 ml, normal: 2.5-4.5 ng/100 ml). Oestradiol (Oe2) was normal (1.7 ng/100 ml, normal: 1.5-3 ng/100 ml. Oe1/Oe2 was slightly elevated (3.6, normal: 1-2). At laparotomy, testes were found and spermatic vein blood was obtained prior to castration. Androgen determinations of spermatic vein blood demonstrated extremely high delta4 levels (283 microgram/100 ml) and low levels of T (16 microgram/100 ml). delta4/T in spermatic vein was 17, higher than in the peripheral blood, suggesting intact peripheral conversion of delta4 to T. Incubation of testes slices with delta4 demonstrated severely impaired conversion to T. Conversion of Oe1 to Oe2 was impaired to a lesser degree. CONCLUSION: 17-ketosteroid reductase deficiency was documented in vivo by impaired conversion of precursor hormones resulting in higher than normal delta4T and Oe1/Oe2 ratios in blood. In vitro studies with testes slices confirmed the enzymatic defect.

17-Hydroxysteroid Dehydrogenases↗

[Leydig cell function in cryptorchid boys (author's transl)].

Testicular endocrine function was assessed in 54 cryptorchid boys, 9 of whom had previously been treated with human chorionic gonadotrophin (HCG). Two different HCG tests were used, the first being short (5,000 IU/m2) and the second more prolonged (3 x 1,500 IU). The testosterone response to the two tests is both quantitatively and qualitatively different. HCG therapy abolishes the differences between cryptorchid boys and controls, which may explain the conflicting results of HCG tests in literature. The results also suggest that the absence of the late testosterone response during the short test in the cryptorchid boys not treated with HCG is due to a reduced and exhaustable Leydig cell function.

Child↗

[Treatment by human chorionic gonadotropin in maldescended testes. (Synthesis of our experience)].

87 prepuberal children, 2-15 years old, 58 with unilateral and 29 with bilateral cryptorchidism, were treated intramuscularly with Human Chorionic Gonadotropin (HCG). HCG was administered in 16 children in single dose (5.000 IU/m2), in 11 children every other day for one week (3 x 1,500 IU) and in 60 children twice a week (2 x 1,000 IU) for 3-7 weeks. Treatment was successful in 31% of children. The most effective HCG dosage ranged between 10,000 and 14,000 IU (2 x 1,000 IU once a week for 5-7 weeks). The best therapeutic response was obtained in inguinal cryptorchid testes (39,3%), in unilateral cryptorchidism (34,5%) and in children aged 5-10 years (42,3%). The observed androgenic side effects (32%) subsided within 3-12 months after therapy suspension. The HCG therapy appears of particular value in cryptorchidism treatment. Surgical management is indicated in cases of true ectopic testes and after failure of HCG therapy.

Adolescent↗