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Biomedical subjects

L Tatò

Publications and source records attributed to L Tatò.

At least 19 recordsLinked to original sources
PubMed1997

Growth hormone bioactivity and levels of growth hormone, growth hormone-binding protein, insulinlike growth factor I, and insulinlike growth factor-binding proteins in premature and full-term newborns during the first month of life.

OBJECTIVE: To assess the pattern of growth hormone bioactivity (GH-BIO) and the levels of GH-binding protein (GH-BP), insulin-like growth factor I (IGF-I), and insulin-like growth factor-binding proteins (IGFBPs) in the first month of life in premature and full-term (FT) newborns. PATIENTS AND METHODS: Serum samples were collected from 9 premature newborns who were small for gestational age, 18 premature newborns who were of appropriate size for gestational age, and 20 FT newborns on the 4th and 30th days of life to evaluate the GH-BIO using the Nb2 cell bioassay, the GH levels using a radio-immunoassay (GH-RIA), and the levels of GH-BP, IGF-I and IGFBPs. RESULTS: On day 4, the GH-RIA and GH-BIO values were increased in all newborns (P < .05) compared with values in the prepubertal control subjects. The GH-BP levels were low in all newborns, with the lowest values (P < .05) found in the premature newborns and positively correlated with gestational age (P < .001). The IGF-I levels were also low, with lower values (than those found in the FT newborns) (P < .005) found in the premature group and positively correlated with the GH-BP levels (P < .001) and gestational age (P < .001). The levels of IGFBP-1 and IGFBP-2 were high, with higher values found in the premature newborns than in the FT newborns (P < .05) and negatively correlated with gestational age (P < .005). The IGFBP-3 level was lower in the premature (P < .05) than in the FT newborns and positively correlated with gestational age (P < .005). During the first month of life, the GH-RIA and GH-BIO values were significantly decreased in all newborns (P < .001), while the IGF-I level was increased in the premature newborns (P < .005). The GH-BP levels were increased only in the FT newborns (P < .001). CONCLUSIONS: The elevated bioactive GH level seen in the first few days of life seemed to be attributable to a low IGF-I level secondary to a decreased number and/or function of the GH receptors. The decrease in the serum GH level observed thereafter seemed to be secondary to an increase in the IGF-I level in the premature newborns; however, other factors may have been involved in the FT newborns in whom no increase in the IGF-I level was observed.

Aging↗
PubMed1997

Growth deficiency in polytransfused beta-thalassaemia patients is not growth hormone dependent.

OBJECTIVE: Growth deficiency is commonly seen in polytransfused beta-thalassaemia patients, especially in adolescence. It is not completely dependent on the lack of their pubertal growth spurt. GH impairment at different levels (hypothalamic or pituitary) and/or a reduced IGF-1 synthesis have been suggested the main causes of stunted growth in these patients. We evaluated the relationship between GH reserve and growth in short beta-thalassaemia patients. PATIENTS: Twenty-nine short patients (height < -1.8 SDS for chronological age) were divided into two groups (low and normal responders) on the basis of their GH peak during insulin and clonidine tests (< or = and > 20 mU/l, respectively). All but one low responders underwent the GHRH test to exclude the impairment of somatotroph function and in eight of them an IGF-1 generation test was also performed. The two groups were compared with each other with respect to growth (height deficiency, height velocity, bone age and bone delay), haematological characteristics (serum ferritin levels, age at the start both of low (subcutaneous) s.c. infusion of desferrioxamine and of transfusional therapy) and serum IGF-1 and IGF-1 binding protein 3 levels. RESULTS: Thirteen patients (45%) (11 males, two females) were low responders, all but two having serum IGF-1 < 5th centile (< 0.1 centile in 42%); the GHRH test excluded the impairment of somatotroph function in 8/12. Height deficiency, serum ferritin levels, and age at the start of s.c. chelating therapy did not differ in low compared to normal responders. Height was negatively correlated both with the age at the start of s.c. chelating therapy and with serum ferritin levels. CONCLUSION: The reduction of GH reserve, more frequently due to a hypothalamic than to a pituitary dysfunction, is frequent in polytransfused beta-thalassaemia patients, especially in males. The height function is not related to the GH reserve, given the current methods for testing GH reserve. Late start of s.c. chelating therapy as well as haemosiderosis seem to play a role in the height deficiency, but not in GH reserve. Impairment of GH secretory reserve, therefore, cannot be considered the main cause of height deficiency in these patients.

Adolescent↗
PubMed1997

[Graves' disease].

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Antithyroid Agents↗
PubMed1996

Postnatal variations of growth hormone bioactivity and of growth hormone-dependent factors.

OBJECTIVE: To evaluate whether the low insulinlike growth factor I (IGF-I) levels that are observed in the neonate depend on the biological inactivity of the molecular forms of growth hormone (GH) or on the immaturity of the hepatic GH receptors during the early postnatal period. MATERIALS AND METHODS: Serum samples were collected from 60 normal full-term neonates on day 5 and at 1 and 4 months of age to evaluate the GH concentrations by using both an immunofluorometric assay and Nb2 cell bioassay, as well as the GH-binding protein, IGF-I, and IGF-binding protein 3 values by radioimmunoassay. RESULTS: Five-day-old neonates showed significantly higher (P < .001) mean +/- SEM GH levels that were measured by using the immunofluorometric assay (27.22 +/- 1.62 micrograms/L) and Nb2 cell bioassay (3.56 +/- 0.14 U/mL) compared with those levels in 11 prepubertal children who were studied as control subjects (1.26 +/- 0.28 micrograms/L and 0.74 +/- 0.08 U/mL, respectively). At 1 and 4 months of age, GH values that were measured by using both the immunofluorometric assay (9.15 +/- 0.89 and 2.58 +/- 0.32 micrograms/L, respectively) and Nb2 cell bioassay (2.52 +/- 0.11 and 1.71 +/- 0.15 U/mL, respectively) were decreased significantly (P < .001). In 5-day-old neonates, we observed significantly lower (P < .001) serum GH-binding protein (9.73% +/- 0.42%), IGF-I (67.63 +/- 5.20 ng/mL), and IGF-binding protein 3 (1.46 +/- 0.17 mg/L) concentrations compared with those in the prepubertal children (30.74% +/- 2.01%, 210 +/- 25 ng/mL, and 3.08 +/- 0.22 mg/L, respectively). At 1 month of age, serum GH-binding protein (16.00% +/- 0.70%) and IGF-binding protein 3 (2.96 +/- 0.30 mg/L) values were increased significantly (P < .001), while IGF-I levels (72.55 +/- 7.6 ng/mL, P = .09) were not increased. Serum IGF-I values were increased significantly (P < .005) at 4 months of age (97.94 +/- 9.68 ng/mL). CONCLUSION: The interaction of bioactive molecular forms of GH with the increased hepatic GH receptors induces the rise in postnatal IGF-I levels in early infancy.

Age Factors↗
PubMed1996

Epidemiological survey of goiter and iodine deficiency in Veneto region.

The aim of this paper was to determine goiter prevalence and urinary iodine excretion in the Veneto region. It is known since ancient times that goiter prevalence has affected mainly the mountainous areas in Italy. An extensive epidemiological survey was carried out in school-aged children, visiting 5,439 students and testing 1,883 urinary samples. A goiter prevalence of 8.8% was found in the Region; 7.7% of grade 1A and 1.1% of grade 1B respectively; in the pre-mountainous area the prevalence was higher than 10% (11.7% in the Treviso area and 12.7% in the Vicenza area). Urinary iodine excretion was less than 100 mcg/cr in about 45% of all examined children, with a peak of 20% under 50 mcg/cr in the Vicenza district. According to the WHO criteria, the goiter prevalence in the Veneto area can be considered under the limits of epidemic standards. Nevertheless we feel that in light of the urinary data a prophylaxis with iodine added salt should be recommended in any case.

Child↗
PubMed1996

Gonadal function and response to growth hormone (GH) in boys with isolated GH deficiency and to GH and gonadotropins in boys with multiple pituitary hormone deficiencies.

OBJECTIVE: [corrected] To evaluate spermatogenesis in patients with isolated GH deficiency and multiple pituitary hormone deficiencies. DESIGN: Treatment of isolated GH-deficient patients with recombinant human GH (weekly dose of 0.7 IU/kg) for 5.3 +/- 0.4 (mean +/- SD) years and cotreatment of multiple pituitary deficient patients with GH at the same dosage for 8.0 +/- 0.4 years and hCG (2,000 IU, three times per week) and hMG (500 IU, two times per week) for 13.7 +/- 1.1 months. SETTING: Endocrine Pediatric Unit. PATIENTS: Eight patients affected by isolated GH deficiency and seven by multiple pituitary hormone deficiencies. MAIN OUTCOME MEASURES: Serum LH, FSH, and T, testicular volume, semen volume, density, count, and motility. RESULTS: Patients with isolated GH deficiency completed their pubertal development in 19.0 +/- 3.5 months and patients with multiple pituitary hormone deficiencies in 13.7 +/- 1.1 months. At the end of puberty, the two groups of patients had similar testicular volume, penis size, sperm concentration, motility, and morphology, although T levels and seminal volume were lower in isolated GH-deficient patients than in multiple pituitary deficient patients. CONCLUSIONS: The two groups of patients, treated specifically for their identified hormonal deficiencies, in the end had similar satisfactory reproductive results.

Adolescent↗
PubMed1996

[Precocious puberty].

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Antineoplastic Agents, Hormonal↗
PubMed1995

Use of the gonadotropin-releasing hormone agonist triptorelin in the diagnosis of delayed puberty in boys.

To differentiate gonadotropin deficiency from delayed puberty in teenage boys, 0.1 mg/m2 of triptorelin, a gonadotropin-releasing hormone agonist, was administered subcutaneously at 4 AM. Serum gonadotropins and testosterone levels were determined at baseline and 4 hours after the injection. The increase in blood gonadotropin and testosterone levels was significantly greater in patients with delayed puberty than in those with gonadotropin deficiency.

Adolescent↗
PubMed1995

Use of combined Gn-RH agonist and hGH therapy for better attining the goals in precocious puberty treatment.

We studied 30 girls (age 6.36 +/- 1.21 years, range 4.6-8.8) affected by idiopathic precocious puberty with significant reduction of height velocity (below the 25th centile) at the end of 1 year of Gn-RHa (triptorelin intramuscular depot) treatment, to evaluate GH-IGF-I axis activity and the effects of combined Gn-RHa plus hGH therapy. After 12 months, 15 patients continued Gn-RHa and started hGH therapy for 12 months, while 15 continued treatment with Gn-RHa alone (control group). We evaluated height velocity, bone age, urinary GH, serum IGF-I and IGFBP-3 levels throughout the study; plasma GHBP levels were determined only in the first 12 months of Gn-RHa treatment. Height velocity decreased significantly during Gn-RHa treatment; it increased significantly and became higher than the control group after 12 months of Gn-RHa plus hGH treatment. During Gn-RHa therapy alone, bone age progressed less than chronological age, while in the 12 months of Gn-RHa plus hGH treatment there was a slight nonsignificant increase in bone age progression in comparison to controls. Serum IGF-I and IGFBP-3 levels decreased significantly at 12 months of Gn-RHa therapy and increased significantly after Gn-RHa plus hGH treatment. Urinary GH levels showed the same behavior. Plasma GH binding to peak II-BP, slightly lower than the prepubertal normal range before treatment, significantly increased after 12 months of Gn-RHa treatment. Therefore, in these girls, during Gn-RHa treatment alone, we have a reduction in GH-IGF-I axis activity. During Gn-RHa plus hGH therapy there was a significant increase in height velocity, in urinary GH levels, in serum IGF-I and IGFBP-3 levels. Bone age did not seem to advance faster than chronological age and this may imply a better prediction in adult height. In our opinion, only in a small percentage of patients affected by precocious puberty (with a very low predicted adult height or an important reduction of growth velocity during Gn-RHa treatment) may an association with hGH therapy be useful.

Body Height↗
PubMed1995

Bone mineral metabolism in girls with precocious puberty during gonadotrophin-releasing hormone agonist treatment.

Bone mineral metabolism and mineralization before and during treatment were studied in 10 girls aged 6.9-8.4 years affected by central precocious puberty and treated with gonadotrophin-releasing hormone agonist (GnRHa) leuprolide acetate depot, in order to understand better the consequences of oestrogen deficiency and the reduction of growth hormone (GH)-insulin-like growth factor I (IGF-I) axis activity. Before and after 12 months of therapy, the patients underwent a clonidine stimulation test and a 4-day calcitriol osteoblast stimulation test. On day 0, day 5 and at 3-month intervals thereafter, serum calcium, phosphate, alkaline phosphatase, IGF-I, IGF binding protein 3 (IGFBP-3), GH, GH binding protein and osteocalcin levels were measured; urinary calcium, phosphate and hydroxyproline levels were evaluated in fasting spot samples. Trabecular and cortical bone mass variations, measured by dual X-ray absorptiometry in the lumbar spine and by dual photon absorptiometry in the radius, respectively were evaluated before the start and after 12 months of therapy. During treatment, a decrease of serum oestradiol levels from pubertal to prepubertal levels was observed. The GH peak following clonidine diminished significantly after 1 year. Growth hormone binding protein showed a slight increase, and IGF-I and IGFBP-3 decreased, although not significantly. Osteocalcin levels decreased significantly after 9 and 12 months of treatment, but they did not change significantly after calcitriol load, either before or after GnRHa therapy. Urinary hydroxyproline decreased significantly after 12 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Height↗
PubMed1994

Capillary zone electrophoresis determination of phenylalanine in serum: a rapid, inexpensive and simple method for the diagnosis of phenylketonuria.

A simple, rapid, and quantitative capillary zone electrophoresis method for phenylalanine analysis in serum has been developed, with the aim of providing an analytical tool, as an alternative to liquid and gas chromatography, for the routine laboratory diagnosis of phenylketonuria. Electrophoresis was carried out in a 65 cm long, 50 microns wide bare silica capillary, using 0.025 M borate (adjusted to pH 10 with 1 M NaOH) at a potential of 20 kV, with in-column UV detection at 214 nm. Under these conditions, the three aromatic amino acids (tryptophan, phenylalanine and tyrosine) migrated according to the pKs of the respective amine (and hydroxyl) groups. The efficiency of separation was about 150,000 plates/column for phenylalanine. Diprophylline was adopted as internal standard. The injection of ethanol-deproteinized normal control serum gave rise to only a few major peaks not interfering with phenylalanine; phenylalanine in serum at normal concentrations appeared in a clean region of the electropherogram as a symmetrical peak with a migration time of about 11 min. The sensitivity was > or = 3 micrograms/mL, with s/n ratio = 3. The linearity, in the range of 5-175 micrograms/mL, was described by the equation y = 1.407-0.583 x, r2 = 0.9998. Accuracy and precision were satisfactory, with intra-day and inter-day coefficients of variation lower than 4% and 7%, respectively. The injection of sera from five phenylketonuria patients gave electropherograms clearly showing huge peaks of phenylalanine, thus allowing an easy laboratory diagnosis of phenylketonuria.

Capillary Action↗
PubMed1994

[The therapy of congenital hypothyroidism].

In congenital hypothyroidism precocious diagnosis and consequent replacement therapy are necessary to prevent neurological irreversible damage caused by postnatal thyroid hormone deficiency. Synthetic L-thyroxine is the useful drug, that has to be administered in fasting condition to have the best absorption. Some points about the treatment are still discussed, such initial L-thyroxine dosage, biochemical control parameters and psycho-intellectual outcome in treated patients. The mean initial dosage in Italy increased from 7.5 +/- 2.2 micrograms/kg/day in 1987-90 period to 8.5 +/- 2.5 micrograms/kg/day in 1991, at a mean starting age of 34 and 26 days respectively. Therefore the dosage is modulated on the basis of serum levels of thyroid hormones and clinical signs. Some patients, in spite of a correct dosage of L-thyroxine, show a deficient suppression of TSH circulating level. In our experience this finding is sometimes due to the non-observance of the fasting condition when the drug is administered. Patients precociously identified by neonatal screening and correctly treated have a good mental and statural prognosis. In these patients, the psycho-intellectual development is better than in those diagnosed later clinically.

Child↗
PubMed1993

Effects of 1,25-dihydroxyvitamin D3 and growth hormone therapy on serum osteocalcin levels in children with growth hormone deficiency.

In order to investigate the influence on bone metabolism of growth hormone (GH), we evaluated the response to an acute load of 1,25(OH)2D3 (Rocaltrol) (1.5 micrograms/day for 4 days) in 16 growth hormone-deficient prepubertal children (11 boys and 5 girls, aged from 6.2 to 9.6 years) both before and after 1 month of human GH (hGH) therapy (0.1 IU/kg/day, 6 times per week). Before and after the 1,25(OH)2D3 load, serum IGF-I, osteocalcin, Ca, P, alkaline phosphatase (ALP) and urinary excretion of Ca and P were measured. The serum levels of osteocalcin rose significantly after the first 1,25(OH)2D3 load, without an increase in IGF-I values and with a slight non-significant increase in serum Ca and P. Almost superimposable increases of osteocalcin, Ca and P were observed after 1 month of hGH therapy, with a significant increase of IGF-I, but they did not rise further after the second 1,25(OH)2D3 load. On the basis of our results, 1,25(OH)2D3 seems to have a stimulatory action on osteoblastic activity even in the absence of normal levels of GH. However, there is no apparent additional stimulatory activity after administration of hGH. Osteocalcin level behaviour during our study might suggest that GH and 1,25(OH)2D3 have a common and easily saturable stimulatory pathway on osteoblastic function.

Alkaline Phosphatase↗
PubMed1993

Influence of dietary taurine on vitamin D absorption.

To evaluate the influence of dietary taurine supplementation on vitamin D absorption, we studied three groups of infants: 21 (11 preterm) were fed a taurine-free formula, 21 (10 preterm) were fed a taurine-supplemented formula (50 mg/100 g of powder) and 20 (9 preterm) were fed human, not heat-treated milk. Taurine, total bile acids, glyco-(GBA) and tauro-(TBA) conjugated bile acids, 25-hydroxyvitamin D3 (25OHD3) and 1,25-dihydroxyvitamin D3 (1,25OH2D3) were determined in all infants at birth in blood cord and at one and three months of life. In preterm infants fed a taurine-free formula, we found lower plasma taurine levels than in infants of other groups at one and three months of life. In these infants, GBA predominated, with a G/T ratio of 1.1 and 1.4 at one and three months of life, whereas in all other infants TBA predominated with a G/T ratio always < 1. Also, 25OHD3 and 1,25OH2D3 levels were significantly lower in preterm infants fed a taurine-free formula than in infants fed a taurine-enriched formula or human milk. Term infants fed a taurine-free formula did not show differences in the parameters studied in comparison to infants of other groups. Low taurine dietary intake appears to compromise vitamin D absorption in preterm infants, and therefore taurine supplementation of preterm infant formulas should be encouraged.

Bile Acids and Salts↗
PubMed1993

Bone mineral density in children and adolescent females treated with high doses of L-thyroxine.

Single-photon absorptiometry was used to assess forearm bone mineral content (BMC) at a proximal site (PBMC) and at a more distal site (DBMC) of the non-dominant distal forearm in 20 children and adolescent females taking high doses of L-thyroxine (120 micrograms/m2/day) for a period of 6-96 months for endemic goiter, Hashimoto's thyroiditis or thyroid cancer. PBMC was significantly reduced compared to controls (p < 0.002). No correlation was found between PBMC, the values of circulating thyroid hormones and the indices of tissue hyperthyroidism such as TSH and systolic time intervals (STI), suggesting that bone is a very sensitive target for thyroid hormones. Further studies are necessary to confirm our findings and to verify their clinical significance. At present, we believe that suppressive doses of L-thyroxine should be reserved for cancer patients only.

Adolescent↗
PubMed1993

Impaired response of free alpha-subunits after luteinizing hormone-releasing hormone and thyrotropin-releasing hormone stimulations in beta-thalassemia major.

In order to clarify whether the damage in gonadotropin secretion due to iron overload in patients with beta-thalassemia is of pituitary or hypothalamic origin, 14 euthyroid patients (8 females and 6 males, age 15-24 years) affected by beta-thalassemia major with hypogonadotropic hypogonadism were studied. Luteinizing-hormone (LH), follicle-stimulating hormone (FSH) and free alpha-subunit (FAS) were measured during LH-releasing hormone (LH-RH) stimulation test, and thyroid-stimulating hormone (TSH), prolactin (PRL) and FAS during thyrotropin-releasing hormone (TRH) stimulation test. During LH-RH stimulation, the mean basal LH, FSH and FAS levels were similar to those found in normal prepubertal children, but the peak values were lower than those found in such children. Also during TRH stimulation, the mean peak values of FAS were lower than those of normal prepubertal children, but the TSH response was normal. The lack of response of gonadotropins and FAS to LH-RH cannot exclude hypothalamic failure; however, the normal response of TSH to TRH, in spite of the poor response of FAS, indicates that the origin of hypogonadotropic hypogonadism is the pituitary damage concerning not only the gonadotroph but also the thyrotroph cells.

Adolescent↗
PubMed1992

Oral zinc as initial therapy in Wilson's disease: two years of continuous treatment in a 10-year-old child.

Two years of continuous therapy promoted a significant overall amelioration in a 10-year-old boy affected by an hepatic form of Wilson's disease in which zinc sulphate was the sole therapy. In particular, liver function returned to normal and hepatic histology also improved. The parameters characterizing copper metabolism were kept under good control, and a decrease in copper concentration was found in both erythrocytes and liver. The copper balance study performed during the 25th month of treatment showed that oral zinc was still efficiently inhibiting the intestinal absorption of copper. No side effects have been reported so far.

Administration, Oral↗