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Biomedical subjects

F Severi

Publications and source records attributed to F Severi.

At least 91 records · Page 5Linked to original sources
PubMed1989

Autoimmunity, HLA, Gm and Km polymorphisms in Turner's syndrome.

Considering the high frequency of autoimmune disorders in Turner's syndrome and the close relationship between autoimmunity, HLA and immunoglobulin constant region gene polymorphisms, we studied 46 patients with Turner's syndrome, by determination of autoantibodies, HLA histoglobulins and Gm and Km allotypes. OSA and in particular PCA resulted significantly more frequent in patients than in the controls. A higher frequency of HLA-A31, B38 antigens and of blanks at HLA-A locus was found in Turner's subjects than in the controls. A31 was significantly more frequent in autoantibody positive patients while B38 was more frequent in autoantibody negative Turner's subjects than in the controls. DR4 antigen was present only in autoantibody negative patients. Gm 3; 23; 5* phenotype was significantly less frequent, while Gm 3;..; 5* phenotype was more frequent in patients than in controls. Our data confirm the higher incidence of autoimmunity disorders in Turner's syndrome than in normal subjects. Particular HLA and immunoglobulin types seem to mark this condition. The increase in the blank frequency at A locus could be explained by the presence of a rare antigen at HLA-A locus or a particularly elevated homozygous condition in these subjects.

Adolescent↗
PubMed1989

[Contribution of pelvic ultrasonography in the diagnosis and follow-up of Turner's syndrome].

Between 1983 and 1988, 40 patients with Turner's syndrome, aged 8 to 26 years, underwent serial pelvic ultrasonography, in order to evaluate the morphofunctional parameters of the internal genital apparatus and correlate them with the karyotype and gonadotropin levels. Correlation of uterine and gonadal sonograms (site, size and echogenic potential) with the karyotype and the gonadotropin assays, permits the definition of each case and a personalized therapeutic approach as well as a control of its efficacy and/or its side-effects.

Adolescent↗
PubMed1988

Effectiveness of growth hormone (GH) therapy in GH-deficient children and non-GH-deficient short children.

The growth response during short-term growth hormone (GH) treatment was evaluated in eight prepubertal non-GH-deficient (non-GHD) children and compared with six prepubertal GH-deficient (GHD) patients. Standard doses of GH can improve growth rate in GHD and in some non-GHD patients. In neither group the growth response can be predicted by the acute increase in Thymidine Activity or Somatomedin-C levels. A diagnostic trial of GH treatment may be the only certain method of selecting the short non-GHD patients who may benefit from long-term GH therapy.

Adolescent↗
PubMed1988

Italian extended HLA haplotypes in congenital adrenal hyperplasia.

In order to complete the data on human 21-Hydroxylase deficiency, we present a study on HLA markers in 35 Italian families (14 from Northern, eight from Central and 13 from Southern Italy) with one affected child. Three children from the issue of first cousin marriages were homozygous for the whole HLA haplotype. Extended haplotypes shared by unrelated patients were not found, and a total absence of the HLA Bw47 allele among the haplotypes carrying the disease as well as normal haplotypes was observed. The absence of A1 Cw7 B8 BfS C4AQ0 C4B1 DR3 extended haplotype was instead confirmed. Allele frequencies in the different clinical forms were analyzed: BfSO7 allele frequency was significantly increased on haplotypes of the salt-wasting form (p less than 0.01). We noticed two duplications (C4B1-2) of C4B genes, on haplotypes involved in the disease. Allele distribution in the regions studied showed that Bw22 (w55), Cw3 and DR2 were characteristic of Northern patients, while B15 was found in patients from Central Italy.

Adrenal Hyperplasia, Congenital↗
PubMed1988

Impairment of the opioidergic control of luteinizing hormone secretion in Turner's syndrome: lack of effect of gonadal steroid therapy.

We studied the activity of endogenous opioid peptides in regulating LH secretion in patients with Turner's syndrome. To do so, we determined the LH secretory response to opiate receptor blockade by naloxone (0.08 mg/kg BW, iv) in 17 patients (age range, 9-23 yr). Eight patients were untreated (3 of whom had had spontaneous menarche), and 9 patients were taking ethinyl estradiol/medroxyprogesterone acetate treatment (5 of these patients were also studied before treatment). In addition, the plasma LH responses to GnRH (50 micrograms, iv) and placebo were determined in the patients as well as in 13 age-matched normal girls (6 prepubertal and 7 pubertal). Naloxone did not increase plasma LH levels in the amenorrheic untreated and treated patients with Turner's syndrome. However, in the 3 patients who had had spontaneous menarche and in normal pubertal girls naloxone increased plasma LH levels. GnRH was effective to the same extent in the patients and normal subjects. These results indicate that in patients with Turner's syndrome the opioidergic inhibition of LH secretion is impaired and is not restored by gonadal steroid replacement therapy. Moreover, the normal plasma LH responses to naloxone in the spontaneously menstruating patients with Turner's syndrome indicate both the clinical variability of this syndrome and the participation of endogenous opioid peptides in the regulation of normal menstrual function.

Adolescent↗
PubMed1987

Dexamethasone fails to suppress hyperendorphinaemia of obese children.

In order to evaluate the origin of hyperendorphinaemia in obese patients, plasma B-endorphin (B-EP), B-lipotropin (B-LPH) and cortisol levels were measured in basal conditions and after overnight treatment with 1 mg of dexamethasone. Thirteen obese children (weight excess ranging from 44 to 100%) and 10 normal weight controls were studied. Weight gain started in prepuberty and could not be explained by concurrent diseases. Hormone levels were measured by RIA, either directly in the plasma (cortisol) or after silicic acid extraction and Sephadex G-75 column chromatography (B-EP and B-LPH). Basal B-EP levels in the obese children (19.4 +/- 4.9 pmol/l, mean +/- SEM) were significantly higher than in the controls (7.8 +/- 1.2, P less than 0.01), whereas B-LPH and cortisol was within normal range. In the controls, post-dexamethasone morning and afternoon hormone levels were significantly suppressed. In the obese children, B-EP concentrations remained unaffected by the treatment (14.6 +/- 5.3 and 14.9 +/- 5.2 at 08.00 and 16.00 h, respectively), whereas both B-LPH and cortisol values were significantly decreased. These data demonstrate that a short-term dexamethasone treatment is unable to correct the increased B-EP levels which characterize obese children, whereas it is effective on B-LPH and cortisol concentrations. It can be concluded that circulating B-EP in this condition loses the control of CRH. However, the origin of hyperendorphinaemia in obese patients still remains to be investigated.

Adolescent↗
PubMed1986

Auto-immunity in children with diabetes mellitus and in their relatives.

Islet cell antibodies (ICA-IgG and complement-fixing-ICA), parietal cell antibodies (PCA), intestinal epithelial cell antibodies (IECA), thyroglobulin (TgA) and thyroid microsomal antibodies (MsA), antinuclear (ANA) and reticulin antibodies (RA), were studied in 55 insulin-dependent diabetic patients (30 males and 25 females), aged 2-19 years with diabetes from a few days up to 14 years. In 58% of the diabetics one or more autoantibodies were found: ICA-IgG (31%), CF-ICA (16%), PCA (34%), TgA (9%), MsA (9%), ANA (13%), RA (2%). Autoantibodies were significantly more frequent in females (76%) than in males (43%) (P less than 0.025). ICA-IgG, CF-ICA, PCA, ANA were significantly more frequent in patients than in controls. The frequency of ICA-IgG and CF-ICA was significantly higher during the first 3 years of disease than afterwards (P less than 0.001); a similar pattern was observed for PCA, TgA, MsA. Of the 87 parents and 30 siblings screened for ICA-IgG, CF-ICA, PCA, IECA, TgA, MsA, ANA and RA, 42 (44%) had one or more autoantibodies, which were more frequent in females than in males. Seven relatives (6%) were ICA-IgG positive (four mothers, two fathers and one brother), and only one mother, ICA-IgG negative, was CF-ICA positive. Other autoantibodies were also more frequent in parents than in controls. Autoantibody-positive relatives have been asymptomatic up to now.

Adolescent↗
PubMed1986

Synthetic growth hormone-releasing hormone (GHRH 1-44) in the differential diagnosis between hypothalamic and pituitary GH deficiency.

GH response to an iv bolus of growth-hormone-releasing hormone (GHRH 1-44, 2 micrograms/kg iv) was evaluated in 17 prepubertal children with total GH deficiency (GHD), 6 with partial GHD and in 7 prepubertal normal but short children tested as control. GH response to conventional pharmacological (insulin and arginine or L-Dopa) and physiological stimuli (sleep test) and to GHRH test was also compared. GHRH-induced GH peak occurred at variable times and marked heterogeneity in magnitude of the individual responses to this peptide was observed in GHD patients and in controls. GH increases after GHRH with a peak greater than 10 ng/ml suggested an hypothalamic origin of the GHD in 12 patients (8 with total GHD and 4 with partial GHD). A significant difference (p less than 0.025) of GH peak mean following GHRH administration between total GHD children and normal short children was found. GH response to GHRH injection was usually higher than to conventional stimuli. Nevertheless GH peak following GHRH administration was lower than GH peak following conventional stimuli in 6 children (2 partial GHD children and 4 normal ones). A normal short child failed to respond to GHRH test performed twice. GHRH test is an important diagnostic tool in order to point out hypothalamic GHD.

Adolescent↗
PubMed1986

Effects of human growth hormone administration on growth rate and growth-stimulating activity of serum, measured by lymphocyte bioassay in hypopituitary children.

The acute effect of human growth hormone (hGH) upon the serum bioassayable growth-stimulating activity was compared to the long-term effects of hGH on growth rate in two groups of hypopituitary patients aged 2-18 years. 12 patients had complete GH deficiency with GH peak below 3.5 ng/ml at two stimulation tests. 15 others, having both GH peaks below 8 ng/ml and at least one above 3.5 ng/ml, were considered as having partial GH deficiency. The growth-stimulating activity of serum was measured by its effect at concentrations 0.03 to 1.25% upon thymidine incorporation into lectin-activated normal human lymphocytes, named thymidine activity (TA). In patients with complete GH deficiency, the pre-treatment TA was positively correlated with the peak response of GH to stimulation tests. The increase of TA after 3-4 days of hGH treatment was positively correlated with the pretreatment TA level, and negatively correlated with the peak GH level. The effect of a 6-12 months therapeutic course of hGH upon the growth rate was positively correlated with the acute increase of TA. No such correlations were found in patients with partial GH deficiency. Many works have discussed the relationship of acute somatomedin responses and long-term clinical results of treatment with hGH in GH-deficient children. The present data, using a highly sensitive bioassay of serum stimulating activity, suggest that the degree of GH deficiency is an important factor to be considered. The response of GH-dependent serum growth factors to acute treatment with hGH could have more predictive value in cases with total lack of growth hormone than in cases of partial deficiency.

Adolescent↗
PubMed1985

Urinary hydroxylysine and hydroxylysyl glycosides excretion in patients with Turner's syndrome.

Urinary excretion of 5-hydroxylysine (Hyl) and its two glycosides, a monoglycoside (Gal-Hyl) and a diglycoside (Glc-Gal-Hyl), and the ratio of the diglycoside to monoglycoside have been studied in 30 patients with Turner's syndrome and in 38 healthy controls. In patients, the urinary excretion of Hyl and its diglycoside was similar to that obtained in the controls, while the excretion of the monoglycoside was significantly lower before the age of 17 years. As a consequence, between 6 and 17 years of age the Glc-Gal-Hyl/Gal-Hyl ratio is significantly higher in patients with Turner's syndrome than in normal subjects. The results of our study seem to indicate a disturbance in the turnover of collagen in Turner's syndrome.

Adolescent↗
PubMed1985

Bioassay of growth-stimulating activity of serum: comparison of lymphocyte and cartilage assays in normal and growth hormone-deficient children.

The somatomedin and/or growth-stimulating activity of serum from hypopituitary children and short children with normal growth hormone (GH) response to stimulation tests were studied using different bioassays: thymidine incorporation into human activated lymphocytes; sulfate incorporation into chick embryo cartilage; and simultaneous thymidine uptake into the same cartilages. The results showed that lymphocyte assay is highly sensitive to small amounts of serum and is GH-dependent in children with low GH secretion. On the contrary, the cartilage assays need higher serum concentration and their GH-dependence appears only in subjects with normal or low-normal GH secretion. The lack of correlation between the results of the three bioassays suggests that they measure both somatomedins and different serum factors involved in the regulation of growth.

Adolescent↗