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Biomedical subjects

G Radetti

Publications and source records attributed to G Radetti.

88 records · Page 5Linked to original sources

Thyrotropin (TSH) secretion in L-thyroxine treated children: assessment by a ultrasensitive TSH immunoradiometric assay.

The clinical usefulness of the measurement of basal TSH by an ultrasensitive assay (IRMA) versus the TRH test has been challenged in 49 children treated with L-thyroxine. They were given suppressive or replacement therapy depending on the underlying disease. An absent response of TSH to TRH could be predicted from a basal TSH value less than 0.1 mU/l in 88.8% of the cases, while only in 77.7% from a basal TSH value = 0.1 mU/l. A basal TSH value found in the range of the normal children always predicted a normal TRH test. We conclude that a sensitive TSH assay has some clinical application in monitoring L-thyroxine therapy, but can not absolutely replace the TRH test.

Adolescent↗

Down's syndrome, hypothyroidism and insulin-dependent diabetes mellitus.

We describe a child with Down's syndrome who developed an insulin-dependent diabetes mellitus at the age of 8 years and hypothyroidism at the age of 17 years. Because of the well known tendency to autoimmune diseases of patients with Down's syndrome, an autoantibody screening was undertaken. Only a low titre for gastric parietal cell antibodies was repeatedly found, but a gastric biopsy did not reveal chronic atrophic gastritis. Thyroid function should be checked periodically in patients with Down's syndrome since they might suffer from hypothyroidism which may not be recognized for a long time because of its latent onset.

Child↗

Thyroid function in type 1 juvenile diabetes mellitus: tendency to the low T3 syndrome.

We have evaluated the thyroid function in 30 children and adolescents (average age 13 2/12 +/- 3 10/12 years) suffering from type 1 insulin-dependent diabetes (average duration of illness 5 +/- 3 3/12 years). We divided them into group A (good control) and group B (poor control), according to whether they had presented an HbA1C value lower or higher than 10%. The results obtained have been compared with a group of 30 normal patients of the same age. Both groups of diabetics presented T4 values which were notably lower than the control group (P less than 0.05). T3 was appreciably diminished both in group A (P less than 0.05) and in group B (P less than 0.01) and presented a negative correlation with HbA1C, only in group A however. The rT3/T3 ratio, on the other hand, was significantly increased in group B with respect to the controls. No significant differences were found with regard to FT3 and FT4, nor any correlations among thyroid hormones, C peptide, duration of illness, and daily insulin requirement. Our results indicated that the tendency to the low T3 syndrome, already described in adult diabetics, is also identifiable in young diabetics, particularly if poorly controlled.

Adolescent↗

[Neonatal spasms caused by cerebral hemorrhage in alpha 1-anti-trypsin deficiency].

This paper describes a case of late neonatal convulsions due to intracranial haemorrhage in a newborn with cholestatic hepatopathy due to PiZZ homozygote alpha-1-antitrypsin deficiency. The deficiency of vitamin K dependent clotting factors, responsible for the haemorrhage, seems to be due to the cholestasis and might have been aggravated by the non-administration of vitamin K at birth and by breast feeding. The response to vitamin K therapy was good.

Cerebral Hemorrhage↗

Hypophyso-gonadal function in the diabetic child.

14 diabetic boys (five with a family history of diabetes and nine without) and 29 "short normal" boys were studied. A gonadal function test (2.000 IU of hCG i.m. for 3 days and plasma testosterone assay before and after the hCG administration) as well as an LH-RH test (50 microgram i.v.) were carried out. While basal testosterone level turned out to be similar in the two groups of children, it was significantly lower (p less than 0.01) after hCG than the mean value of the control group. This difference was mainly observed in those patients with a family history of diabetes. In the diabetic children, basal LH level was normal and the pituitary LH reserve was lower than in the control group. Both basal FSH level and FSH pituitary reserve were lower than in normal children. These data show that an alteration in the hypothalamus-pituitary-gonadal function is already evident in the diabetic child.

Adolescent↗

Cardiovascular effects of high-dose growth hormone treatment in growth hormone-deficient children.

Growth hormone (GH) hypersecretion is associated with an increased incidence of cardiac hypertrophy and subclinical abnormalities of left ventricular (LV) function. The unlimited availability of biosynthetic GH has led to progressively increased dosage when treating GH-deficient children, raising the question of its cardiovascular effects during long-term therapy. We compared 22 children (8 girls, 14 boys), mean age 12.1 years (range 3-17 years) with GH deficiency who were receiving chronic GH treatment (GH group) with 22 normal controls matched for sex and body size in order to evaluate: (1) LV volume, mass, and systolic function by two-dimensional guided M-mode echocardiography; (2) LV diastolic function by pulsed-wave Doppler sampling of the transmitral flow; and (3) cardiac output and systemic vascular resistance by Doppler echocardiography. All patients had been on chronic GH therapy for 13.8 +/- 7.6 months (range 5-30 months) with an average dose of 0.95 +/- 0.12 IU/kg per week (range 0.69-1.17 IU/kg per week). Blood pressure did not differ between the two groups. LV volume, mass, ejection fraction, and mean velocity of circumferential shortening did not differ significantly between the GH group and controls; nor did the peak- and end-systolic meridional stress. All patients had a normal contractile state as estimated by the relation between mean velocity of circumferential shortening and end-systolic meridional stress. The LV filling parameters did not differ between the two groups, and there was no difference in cardiac index and systemic vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Growth hormone bioactivity and immunoactivity in tall children.

In subjects with constitutional tall stature, both low and high GH response to stimulation tests have been observed when measured by commercial kits. To investigate the reason for these conflicting results, we evaluated growth hormone (GH) secretion using different assays as well as GH-binding protein and insulin-like growth factor-I (IGF-I) concentrations in tall children. Serum samples were collected from 22 prepubertal constitutionally tall children, aged 2.87-13.25 years, during two pharmacological tests to evaluate serum GH levels measured by both immunofluorometric assay (IFMA) and the Nb2 cell bioassay. Serum IGF-I values were evaluated by RIA. Circulating low affinity (LA) and high affinity (HA) GH-binding proteins (GHBPs) were evaluated by FPLC gel filtration. Considering the highest serum GH levels as measured by IFMA, the 22 tall subjects were divided into two groups: group A including 16 children with blunted serum GH peak levels (5.78+/-0.68 ng/ml) and group B including 6 subjects with normal serum GH peak values (15.73+/-1.56 ng/ml). No differences were observed in serum GH peak levels as measured by the Nb2 cell bioassay between group A (14.77+/-1.54 ng/ml) and group B (16.03+/-1.96 ng/ml), and between both groups and 11 age-and sex-matched controls (12.25+/-1.19 ng/ml). In group A, the Nb2 cell bioassay/IFMA ratio of serum GH peak levels (0.29+/-0.08) was significantly higher (p<0.05) than in group B (0.07+/-0.01). No differences were found in serum LA-GHBP and HA-GHBP as well as in IGF-I concentrations between the 16 patients of group A and the 6 of group B. Likewise, no difference in auxological parameters was found between the two groups. The biological activity of GH evaluated using the Nb2 cell bioassay is similar in tall children with a low GH response as measured by IFMA in comparison with those with a normal GH response, and is in agreement with both the auxological data and serum IGF-I concentrations.

Adolescent↗

Age-related variation in left ventricular myocardial contractile state expressed by the stress velocity relation.

The assessment of ventricular function plays an important role in the pre- and postoperative management of many congenital heart abnormalities. Normal ranges in left ventricular systolic function indices have been defined during childhood and age-related alterations in left ventricular myocardial contractile state have recently been reported. This study was carried out to investigate the developmental changes in left ventricular contractile state expressed by the endsystolic meridional stress (ESS)/rate-corrected velocity of circumferential fiber shortening (VCFc) relation, calculated by echo in normal children and young adults. We examined 146 healthy subjects (80 males and 66 females), mean age 70.85 +/- 63.89 months (range 0.5-228) and body surface area (BSA) 0.807 +/- 0. 47 (range 0.18-2.01) with no clinical and echocardiographic evidence of cardiac disease and with normal blood pressure. The subjects were divided into three groups according to age: <6 months (group 1, n = 32), 6-36 months (group 2, n = 34), and >36 months (group 3, n = 80). Enddiastolic volume and mass (M) of the left ventricle were measured by M-mode Echo. ESS was considered as an index of afterload and the VCFc as an index of systolic ventricular function. The left ventricular ejection time used for the calculation of VCFc was measured from aortic flow obtained by PW-Doppler. The ESS/VCFc relation was used to assess left ventricular contractility. Systolic blood pressure, volume, and mass of the left ventricle increase with age. The gradual increase in pressure despite a stable mass/volume ratio [M/V = 0.900 + (0.0007 x age); r = 0.27, p < 0.005] resulted in a substantial increase of afterload [ESS = 29.78 + (0.116 x age); r = 0.58, p < 0.0001]. VCFc showed an inverse hyperbolic regression with afterload [VCFc = 1.01 + (7.598/ESS); r = 0.59, p < 0.0001]. The regression lines (best linear fit) between VCFc and ESS are significantly different in the three groups. The Y intercept was higher and the slope steeper in group 1 [VCFc = 1.74 - (0.017 x ESS); r = 0.65, p < 0.0005] vs group 2 [VCFc = 1.54 - (0.008 x ESS); r = 0.58, p < 0.001] and group 3 [VCFc = 1.52 - (0.007 x ESS); r = 0.57, p < 0.0001]. These data indicate that, in children, the volume and mass of the left ventricle increase, whereas the M/V ratio remains relatively constant; the progressive increase in arterial blood pressure explains the increase of afterload. The VCFc is higher in the first few years of life compared to that seen in older children due to reduced afterload and increased contractile state. Left ventricular contractility, expressed as ESS/VCFc relation, is thus inversely proportional to age. In the first months of life the left ventricular myocardium exhibits a higher basal contractile state and a greater sensitivity to changes in afterload. For obtaining an accurate assessment of left ventricular function, the ESS/VCFc relation in different age groups should be measured.

Adolescent↗

Possible role of plasma neurotensin on growth hormone regulation in neonates.

OBJECTIVE: To evaluate secretion of plasma neurotensin (NT) which could be involved as a peripheral signal in growth hormone (GH) regulation, NT release was measured during early postnatal life, a period of striking changes in GH secretion. METHODS: Blood samples were collected from 19 normal full-term neonates on day 5 and at 3 months of age to evaluate plasma NT concentrations by radioimmunoassay, serum growth hormone (GH) levels using an immunofluorometric assay, and serum insulin-like growth factor-I (IGF-I) values by radioimmunoassay. RESULTS: Five day-old neonates showed significantly higher (p < 0.001) mean (+/- SEM) plasma NT levels (83.55 +/- 12.07 fmol/ml) compared with those in 11 prepubertal children and those in 14 adults who were studied as control subjects (13.30 +/- 2.90 and 9.70 +/- 1.10 fmol/ml, respectively). In 5 day-old neonates we observed significantly higher (p < 0.001) serum GH levels (29.53 +/- 3.40 ng/ml) compared with those in the prepubertal children (1.26 +/- 0.28 ng/ml). Five day-old neonates showed significantly lower (p < 0.001) serum IGF-I concentrations (27.01 +/- 0.77 ng/ml) than those in the prepubertal children (210 +/- 25 ng/ml). At 3 months of age, plasma NT levels (59.37 +/- 7.47 fmol/ml) and serum GH values (4.40 +/- 0.60 ng/ml) were significantly decreased (p < 0.001). At the 3rd month of life, serum IGF-I levels (44.88 +/- 4.30 ng/ml) were increased significantly (p < 0.001). CONCLUSIONS: The human neonate showed very high concentrations of NT and GH in comparison with those observed in control subjects. The postnatal rise in IGF-I values is presumed to determine the fall in serum GH concentrations by stimulating somatostatin secretion. Neurotensin could be involved as a peripheral signal in the inhibitory mechanisms mediated by release of somatostatin.

Adult↗

[Bone density in swimmers].

Bone mineral density of the non-dominant forearm was measured by single-photon absorptiometry at a proximal site (PBMD) and at a more distal site (DBMC) in 9 competitive male swimmers, aged 18 to 23 years, who had been training for 12 +/- 2 years, 10.3 +/- 5.6 hours a week. The results were compared with 25 age-matched controls. PBMD was m +/- SD 0.57 +/- 0.02 g/cm2 in the swimmers and 0.57 +/- 0.05 g/cm2 in the controls. DBMD was 0.45 +/- 0.02 g/cm2 in the swimmers and 0.45 +/- 0.03 g/cm2 in the controls. No difference was found between the two groups. We can therefore conclude that swimming, in absence of gravity, didn't provide our athletes with an effective mechanical load capable to increase bone density of the forearm.

Absorptiometry, Photon↗

[Monitoring the treatment of precocious puberty with a GnRH-analog (buserelin): comparison of the GnRH-test with nocturnal pulsatility of LH, testosterone and 17-beta-estradiol].

We studied in 10 children (3 boys and 7 girls), affected by precocious puberty and treated for a period of more than 6 months with the GnRH-analog Buserelin, the efficacy of the GnRH test versus the study of spontaneous nocturnal secretion of LH, testosterone and 17 beta-estradiol as a means of testing the gonadotropin suppression. All the subjects have shown a total suppression of LH during the GnRH test as well as a nocturnal profile of LH, testosterone and 17 beta-estradiol of a prepubertal pattern. Clinically all the patients were treated successfully. Considering the effectiveness of both investigations, we conclude that the GnRH test combined with clinical observation is a single and valid means of testing the pharmacological treatment for precocious puberty.

Buserelin↗

[Tendency to low T3 syndrome in type 1 juvenile diabetes. Comparison of treatment with human and porcine insulin].

We investigated the serum thyroid hormones an the degree of diabetic control in 30 children and adolescents suffering from type 1 insulin-dependent diabetes, first while they were being treated with porcine insulin (group A) and then while 23 of them, random selected, were being treated with human insulin (group C). The purpose of our study was to evaluate if the change to human insulin would result in better metabolic control and disappearance of the tendency to the low T3 syndrome that was evidenced in group A. If we compare group A with group C, it can be seen that the degree of diabetic control is higher in group C (decrease in HbA1C), but that the tendency to the low T3 syndrome has not disappeared. Then we selected inside the groups A and C the patients in good metabolic control, and called them respectively group B and group D. If we compare group B with group D it can be seen that there is not any significant difference at all between them and that both groups show a tendency to the low T3 syndrome if compared with the control group (group K). In conclusion, we may state that substituting porcine with human insulin has not brought about any significant metabolic improvement in our patients, as can be seen from the persistent tendency to the low T3 syndrome.

Adolescent↗

[Leri-Weill syndrome (dyschondrosteosis). Description of 2 clinical cases].

We describe two children with Leri-Weill syndrome (Dyschondrosteosis), one of which showed the clinical features at very early age. Stature was moderately reduced in both, due to shortening of the bones of the legs. Furthermore were evident in them the clinical and radiological features of the propositus and of their affected parents are described. The problems concerning the early recognizing of the disease and the genetic inheritance are discussed.

Anthropometry↗