Search PubMed⌕ Search

Biomedical subjects

G Chiumello

Publications and source records attributed to G Chiumello.

At least 19 recordsLinked to original sources
PubMed1999

Comparison of tissue transglutaminase-specific antibody assays with established antibody measurements for coeliac disease.

Tissue transglutaminase C has recently been identified as one of the auto-antigens of endomysial antibodies found in coeliac disease. In this study we have cloned the human autoantigen and developed immunoassays measuring antibodies to transglutaminase in order to compare their diagnostic performance to that of established markers of the disease. A radiobinding assay using in vitro transcribed and translated 35S-methionine-labelled transglutaminase detected IgG antibodies in 110 and IgA antibodies in 109 of 112 patients at diagnosis of coeliac disease and in three and four of 92 control subjects, respectively. A radiobinding assay measuring both IgG and IgA transglutaminase antibodies identified 111 (99.1%) of the patients and 4 (4.3%) control subjects. Concordance of this assay with the IgA endomysial antibody test was found in 108 patients and 89 control subjects: two patients who had IgA deficiency and a third patient without IgA deficiency were only detected in the radiobinding assay; one patient had weak IgA endomysial antibodies only, and three of the control subjects with weak transglutaminase antibodies by radiobinding assay were undetectable in the IgA endomysial antibody assay. IgA and IgG ELISA using guinea pig transglutaminase and commercial ELISA measuring anti-gliadin antibodies had lower sensitivity and specificity than the radiobinding assays or the IgA endomysial antibody assay. This study confirms tissue transglutaminase C as a major autoantigen in coeliac disease and describes novel radiobinding assays for large scale testing to identify cases of coeliac disease.

Adolescent↗
PubMed1999

Bone density and bone metabolism are normal after long-term gluten-free diet in young celiac patients.

OBJECTIVES: Osteoporosis and alterations of bone metabolism are frequent complications of celiac disease. We evaluated the impact of long-term gluten-free diet (GFD) initiated during childhood and adolescence on bone mineralization and bone metabolism. METHODS: We studied 30 celiac patients on GFD for > or = 5 yr. The mean age at diagnosis was 11.4+/-5.0 yr, and the mean duration of GFD was 10.7+/-4.3 yr. Results were compared with those obtained in 240 healthy controls. Bone mineral density (BMD) was measured in the lumbar spine and in the whole skeleton by dual-energy x-ray absorptiometry. Serum levels of bone-specific alkaline phosphatase (BALP) and N-terminal propeptide of type I procollagen (PINP) were measured as bone formation indices, and urine levels of N-telopeptide of type I collagen (NTx) as bone resorption index. RESULTS: BMD measurements of celiac patients (lumbar spine: 1.131+/-0.121 g/cm2; total body: 1.145+/-0.184 g/cm2) did not differ from those of control subjects (lumbar spine: 1.131+/-0.184 g/cm2; total body: 1.159+/-0.118 g/cm2). The levels of BALP, PINP, and NTx of celiac patients did not differ from those of controls. Patients who started GFD before puberty had BMD and bone metabolism measurements comparable to those of patients who started GFD during puberty. CONCLUSIONS: Our data show that long-term dietary treatment ensures normal mineralization and bone turnover.

Absorptiometry, Photon↗
PubMed1998

Comparison of clinical-radiological and molecular findings in hypochondroplasia.

Hypochondroplasia is an autosomal dominant skeletal dysplasia characterized by disproportionate short stature. A mutation (N540K) in the fibroblast growth factor receptor 3 (FGFR3) gene was described in some patients with this condition. The aims of the study were to identify the frequency of the FGFR3 gene mutation, to define the salient clinical and radiological abnormalities of the affected subjects, and to verify the contribution of molecular findings to the clinical and radiological definition of hypochondroplasia. Based on the most common radiological criteria, we selected 18 patients with a phenotype compatible with hypochondroplasia. Height, sitting height, and cranial circumference were measured in all patients. Radiographs of the lumbar spine, left leg, pelvis, and left hand were also obtained. The presence of the N540K mutation was verified by restriction enzyme digestions. Half of our patients carried the N540K mutation. Although similar in phenotype to the patients without the mutation, they showed in addition relative macrocephaly. The association of the unchanged/narrow interpedicular distance with the fibula longer than the tibia was more common in patients with gene mutation. Although we did not find a firm correlation between genotype and phenotype, in our study the N540K mutation was most often associated with disproportionate short stature, macrocephaly, and with radiological findings of unchanged/narrow interpedicular distance and fibula longer than tibia.

Adolescent↗
PubMed1998

Parameters associated with residual insulin secretion during the first year of disease in children and adolescents with Type 1 diabetes mellitus.

Factors associated with residual insulin secretion and spontaneous remission in Type 1 diabetic patients are important in the evaluation of treatment aimed at modifying the natural history of Type 1 DM. We investigated the effect of parameters at onset on residual beta cell function in 215 Type 1 DM children and adolescents. Blood gas analysis, HLA, GAD and IA-2 antibodies before the start of insulin treatment were recorded for each patient. Residual C-peptide secretion was assessed by the glucagon test, and parameters of metabolic control (HbA1c and insulin dose U kg(-1) day(-1)) were examined at disease onset and after 3, 6, and 12 months. Residual C-peptide secretion throughout the first year of disease was significantly reduced in patients with disease onset before age 5. Multiple regression analysis showed that low pH at onset showed a significant and independent association with reduced C-peptide at 3 months (p = 0.02) and that the detection of GAD antibodies had a significant independent association with decreased C-peptide secretion at 6 months of follow-up (p = 0.02). Insulin requirement was higher in the youngest patients group and in patients with GAD antibodies. Spontaneous insulin remission (HbA1c <6% and insulin <0.3 U kg(-1) day(-1)) occurred in 22/192 (11%) patients at 3 months of follow-up, in 15/190 (8%) patients at 6 months and in 8/169 (5%) patient at 12 months. Remission was more prevalent in older patients (p = 0.01) and in patients without detectable GAD antibodies: (14/64 vs 8/128, p = 0.001). Sex, IA-2 antibodies and HLA DR were not independently associated with C-peptide secretion, insulin requirement or remission in the first year of Type 1 DM. This study confirms the association of young age, severe acidosis at disease onset, and GAD antibodies with decreased residual beta-cell function and spontaneous remission during the first year of insulin treatment. These factors should be considered in trials evaluating therapies to retain beta-cell function and induce remission at and after disease onset.

Adolescent↗
PubMed1998

Prader-Willi syndrome: relationship of adiposity to plasma leptin levels.

OBJECTIVE: Prader-Willi syndrome (PWS) is an autosomal dominant disorder involving the proximal long arm of chromosome 15, in which obesity is common. However, there is limited information on the underlying physiological mechanisms promoting obesity in this population. We tested whether there was a significant positive association between leptin and total body fat (TBF) in subjects with PWS, and whether this association was stronger among subjects with than without PWS. RESEARCH METHODS AND PROCEDURES: We studied 21 PWS patients and 64 non-PWS controls on whom we measured serum leptin, total body fat, glucose, insulin, and resting energy expenditure. We tested whether the slope of the regression line between leptin and TBF (in kg), measured by dual energy X-ray absorptiometry, was the same for PWS patients and non-PWS controls. RESULTS: Regression analyses indicated that the leptin-TBF association was significantly stronger among PWS patients. In contrast, the slope of the leptin-body mass index association did not significantly differ between PWS patients and non-PWS controls. None of the other outcome variables showed associations with leptin. DISCUSSION: Results suggest that the role of leptin in promoting obesity may be greater among subjects with PWS than among non-PWS controls.

Absorptiometry, Photon↗
PubMed1998

Urinary markers of bone turnover in healthy children and adolescents: age-related changes and effect of puberty.

During growth, bones change their dimensions rapidly with the changes involving both formation and resorption processes. Small cross-linked peptides coming from type I collagen molecules are excreted in urine when bone is resorbed. To date, conflicting results have been presented concerning the age- and puberty-related changes of urinary markers. The purpose of the present study was to verify the effect of age, gender, and puberty on the urinary excretion of type I collagen degradation products in healthy children and adolescents. Timed spot urines from 176 children (4-20 years old) and 50 young adults were analyzed. The concentrations of N-telopeptides of type I collagen (NTx), pyridinolines (Pyr), and deoxypyridinolines (Dpyr) were measured, and the results were normalized to creatinine. Age-related changes in cross-links excretion were observed. The levels decreased with age, and a peak of excretion was shown at the beginning of adolescence. Prepubertal levels of all the markers were four- to five-fold higher than in adults, and they decreased towards adult levels in late puberty. Girls had significantly higher levels of all biochemical markers than boys at pubertal stage 2. We also observed a remarkable effect of puberty on the levels of bone degradation products that was independent of age and gender. Our results indicate that bone resorption is high in children relative to that in adults, and that urinary levels of NTx, Pyr, and Dpyr change as a function of age, gender, and puberty.

Adolescent↗
PubMed1998

Assessment of skeletal maturation in infants: comparison between two methods in hypothyroid patients.

BACKGROUND: Conventional skeletal radiography is the standard technique for assessing skeletal age. However, radiography cannot demonstrate cartilage and is therefore of lesser value in infancy when the ossification centres are composed mainly of cartilage. By comparison, US clearly demonstrates cartilage and bone. OBJECTIVE: In the present study, we compared radiography and sonography for the assessment of skeletal age in neonates and infants. MATERIALS AND METHODS: Because delayed skeletal maturation is a feature of congenital hypothyroidism and assessment of skeletal age is routinely performed in our centre, we studied 55 hypothyroid infants (aged 7-66 days). AP radiographs and sonograms, acquired using high-frequency scanners, were obtained and dimensions of the distal femoral epiphyseal ossification centre (DFE) were compared. RESULTS: Measurements of DFE by the two methods showed excellent correlation (R = 0.94, P = 0.0001). Radiographs did not demonstrate a DFE in 11 infants, and US did not show it in 6. In no infant did radiography demonstrate DFE not seen by US. Moreover, DFE dimensions on US were larger than those measured on radiographs. Infants with absent thyroid gland had a DFE significantly smaller than those infants with ectopic or normally placed glands (P < 0.001), on both radiographs and sonograms. CONCLUSION: Our data suggest that sonography is a valid alternative to standard radiography for the assessment of skeletal age in infants.

Age Determination by Skeleton↗
PubMed1998

Residual beta-cell function and spontaneous clinical remission in type 1 diabetes mellitus: the role of puberty.

To investigate the role of puberty on spontaneous clinical remission and on secretion of residual C-peptide during the first year of type 1 diabetes mellitus, we studied 77 pre-pubertal, 39 pubertal and 41 post-pubertal type 1 diabetic patients. Spontaneous partial clinical remission (HbA1c within the normal range and insulin dose less than 0.3 U x kg(-1) body weight x day(-1) lasting for at least 10 days) decreased with duration of diabetes: months 3 vs 6 vs 12, respectively 13 vs 7 vs 4% (P<0.025). Remission was higher in post-pubertal than pubertal and prepubertal patients: month 6 respectively 20 vs 5 vs 1% (P<0.001). Secretion of C-peptide was significantly lower in pre-pubertal than the other two groups of patients. Basal and stimulated C-peptide secretion were higher in patients in clinical remission than in those who were not: basal value 0.4 (0.26-0.53) vs 0.28 (0.14-0.4) nmol/l (P<0.05); stimulated value 0.63 (0.5-0.95) vs 0.56 (0.31-0.74) nmol/l (P<0.05). Spontaneous remission is less frequent in children and adolescent patients than in adult post-pubertal patients, but different mechanisms may be involved. Low residual insulin secretion seems implicated in children meanwhile low insulin sensitivity could be more important in pubertal patients.

Adolescent↗
PubMed1998

Body mass index as a measure of adiposity among children and adolescents: a validation study.

OBJECTIVES: To test the hypothesis that in a healthy pediatric population body mass index (BMI) (kilograms per meter square) is a valid measure of fatness that is independent of age for both sexes. METHODS: Total body fat (TBF) (in kilograms) and percent of body weight as fat (PBF) were estimated by dual energy x-ray absorptiometry (DXA) in 198 healthy Italian children and adolescents between 5 and 19 years of age. We developed multiple regression analysis models with TBF and percent body fat as dependent variables and BMI, age, and interaction terms as independent variables. Separate analyses were conducted for boys and girls. RESULTS: BMI was strongly associated with TBF (R2 = 0.85 and 0.89 for boys and girls, respectively) and PBF (R2 =0.63 and 0.69 for boys and girls, respectively). Confidence limits on BMI-fatness association were wide, with individuals of similar BMI showing large differences in TBF and in PBF. Age was a significant covariate in all regression models. Addition of nonlinear terms for BMI did not substantially increase the R2 for TBF and PBF models in boys and girls. CONCLUSION: Our results support the use of BMI as a fatness measure in groups of children and adolescents, although interpretation should be cautious when comparing BMI across groups that differ in age or when predicting a specific individual's TBF or PBF.

Absorptiometry, Photon↗
PubMed1998

Appendicular skeletal muscle mass: prediction from multiple frequency segmental bioimpedance analysis.

OBJECTIVES: Bioimpedance analysis (BIA) methods have potential to predict appendicular skeletal muscle mass (SM), although available 50 kHz prediction models include, in addition to impedance (Z), an independent age term. An age term in models is undesirable as it reflects incomplete understanding of underlying conduction physiology. This study tested the hypothesis, based on fluid distribution models related to aging, that appendicular SM bioimpedance analysis (BIA) prediction models would no longer include an independent age term, after first controlling for stature-adjusted appendicular impedance (height2/Z), at injected frequencies greater than 50 kHz. DESIGN: Cross-sectional evaluation of adults who had segmental Z and phase angle (phi) measured with multiple frequency BIA, and arm and leg SM with dual-energy X-ray absorptiometry (DXA). Skeletal muscle prediction models were developed with appendicular SM as dependent variable and height2/Z, gender, age and phi as potential independent variables. RESULTS: Examination of hypothesis in 49 subjects indicated: both arm and leg SM were highly correlated with height2/segmental Z at frequencies ranging from 1-300 kHz; gender was significant covariate in prediction models only at 1 kHz; age remained a significant covariate after controlling for height2/segmental Z at all frequencies; phi did not add significantly to models; and SM prediction models gave maximum R2 at 50 kHz for arm but R2 continued to rise up to 300 kHz for leg. CONCLUSION: Although multifrequency BIA did not eliminate SM prediction model age term, our findings suggest injected frequencies up to 300 kHz may have advantages for evaluating leg SM over conventional 50 kHz method.

Adult↗
PubMed1998

Dexamethasone in the diagnostic work-up of growth hormone deficiency.

OBJECTIVE: Acute administration of dexamethasone (dexa) has recently been shown to induce growth hormone (GH) release. To ascertain the efficacy of this stimulus in assessing GH secretory status in children, we tested it in a large group of patients with short stature. METHODS: We administered dexamethasone at the dose of 2 mg/m2 to 44 short normal children and 19 GH deficient (GHD) children, either orally or intravenously and compared the results of the dexa-test to the more classical clonidine test. RESULTS: The oral dexa-test induced a GH peak similar to the clonidine test (clo) (controls clo: 23.8 +/- 7.8 mU/l, median 22.8, range 15.2-45.4 vs. control dexa: 20.6 +/- 10.8, median 16.8, range 8-47, P = 0.2. GHD clo: 9.8 +/- 2.6, median 9.2, range 6.4-13.4 vs. GHD dexa: 9.4 +/- 3.4, median 10.2, range 4.6-14, P = 0.8). Its sensitivity and specificity with respect to the clonidine test were 91% (10/11 GHD) and 65% (15/23 controls), respectively. The GH peak after i.v. dexa was smaller than that after clonidine (control clo: 30.6 +/- 14 micrograms/l, median 24.8, range 14.2-62.4 vs. control dexa: 21.6 +/- 5.4, median 21.6, range 11.2-33, P = 0.01. GHD clo: 7.4 +/- 4.2, median 8.8, range 0.4-11.8 vs. GHD dexa: 6.4 +/- 5.6, median 5.8, range 0.4-16.2, P = 0.17) with sensitivity and specificity of 87% (7/8 GHD) and 90% (19/21 controls), respectively. The lower potency of dexamethasone could account for these figures, since when a different cut-off was used (12 mU/l and 11 mU/l for the oral and i.v. route) both sensitivity and specificity were improved. More data are needed to support these findings and establish a clear cut-off. In the control group, no difference was found between GH peak after oral or i.v. dexa but GH-area under the curve (AUC) was larger for i.v. than for oral dexa. No side effects were noted. CONCLUSIONS: Intravenous dexamethasone appears to be a promising stimulus for the detection of GH deficiency in children, particularly for use in outpatients.

Administration, Oral↗
PubMed1998

Reversal of low bone density with a gluten-free diet in children and adolescents with celiac disease.

Osteoporosis is a common finding in adult celiac disease patients; however, there are still few data regarding children and adolescents. In the present study we measured the bone mineral density (BMD) in children and adolescents at diagnosis of celiac disease and after approximately 1 y of a gluten-free diet. BMD was measured at the lumbar spine and in the whole skeleton by dual-energy X-ray absorptiometry in 44 celiac disease patients aged 2.58-20.42 y at diagnosis. BMD was also measured in a subset of 25 patients after 1.4 +/- 0.04 y of a gluten-free diet. BMD was compared with that of 177 healthy control subjects aged 1.52-20.99 y. Lumbar spine and whole-body BMD values at diagnosis of celiac disease were significantly lower than in control subjects (P = 0.015 and P = 0.0001, respectively) after differences in age and anthropomorphic variables were controlled for. The subjects studied after the gluten-free diet had BMD values not significantly different from those of control subjects. In conclusion, children and adolescents with celiac disease have remarkably reduced lumbar spine and whole-body bone density. A gluten-free diet promotes a rapid increase of BMD that leads to a complete recovery of bone mineralization. These results emphasize the need for an early diagnosis and treatment in patients with celiac disease to obtain an adequate peak bone mass at the end of puberty.

Absorptiometry, Photon↗
PubMed1998

Neonatal transient hypothyroidism: aetiological study. Italian Collaborative Study on Transient Hypothyroidism.

AIMS: To define the aetiology of neonatal transient hypothyroidism (NTH) and recommend preventive measures. METHODS: Maternal and perinatal clinical data on the use of antiseptics, drugs, and contrast agents containing iodine were collected from 40 subjects. Thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroxine (T4), thyroglobulin (TG), TSH receptor antibodies, thyroid peroxidase antibodies and urinary iodine were measured in random neonatal samples. In the mothers with known or suspected thyroid disorders, TSH, FT4, TSH receptor antibodies and thyroid peroxidase antibodies were also measured. RESULTS: The NTH aetiology was identified in 85% of cases. More than 50% of the babies with transient hypothyroidism had been exposed to iodine; maternal transfer of antibodies had occurred in a third of them. CONCLUSIONS: It is suggested that the practice of using iodine containing disinfectants should be withdrawn, and chlorhexidine substituted instead; that pregnant women should be advised of the adverse effects of using iodine products; and that thyroid function should be monitored whenever iodine is used.

Adult↗
PubMed1998

Growth changes in children and adolescents with short-term diabetes.

OBJECTIVE: Height and weight changes during the first 3 years of diabetes were prospectively followed in 152 diabetic children and adolescents. RESEARCH DESIGN AND METHODS: The study sample consisted of 152 Caucasian diabetic patients (84 boys; 68 girls) followed from diabetes onset in the Paediatric Diabetes Unit and 80 Caucasian normal subjects (49 boys; 31 girls) assessed in the Outpatient General Paediatric Clinic of the same hospital for routine examination and not affected by problems that might influence growth. Diabetic patients and control subjects were consecutively enrolled in the study between 1989 and 1992; diabetic patients with positive markers for celiac disease (positive antiendomysial antibodies) and thyroid disease (positive antimicrosomial antibodies) or any other chronic disease were not considered in the study. Mean age of diabetic patients (8.9 +/- 4.1 years) and control subjects (8.5 +/- 4.2 years) at recruitment in the study was similar. RESULTS: At onset of diabetes, the mean height expressed as the height standard deviation score (HSDS) was significantly greater than the expected values (P < 0.0001) and was independent of sex and pubertal stage. During the first 3 years of diabetes, HSDS decreased significantly (F = 6.9; P < 0.001). Meanwhile, growth velocity as standard deviation score (SDS) decreased significantly between the 1st and 2nd year (-0.12 +/- 2.1; -0.76 +/- 2.6, respectively; P < 0.05), but it was similar between the 2nd and 3rd year of diabetes. Weight expressed as SDS increased significantly during the first 2 years of diabetes but not thereafter. Height changes during the study period were independent from pubertal stage and sex. Metabolic control and insulin requirement, in our series, were not clearly related to height and weight changes. CONCLUSIONS: Diabetic patients at onset of diabetes are taller than age- and sex-matched nondiabetic subjects. During the first years of the disease, linear growth decreases independently of metabolic control and weight changes.

Adolescent↗
PubMed1997

Bone modeling indexes at onset and during the first year of follow-Up in insulin-dependent diabetic children.

Osteopenia has been described as a complication of insulin-dependent diabetes mellitus (IDDM). We measured bone modeling indexes during the first year of IDDM. At each time point the values obtained from diabetic children have been compared with those of control subjects. We selected 27 prepubertal children with IDDM (6.35 +/- 2.16 years). We also enrolled 30 healthy prepubertal children of comparable age (5.85 +/- 3.05 years). Height, height standard deviation scores, glycated haemoglobin (HbA1C), basal c-peptide concentrations, insulin dose, serum concentrations of procollagen type I C-terminal propeptide (PICP), and collagen type I C-terminal telopeptide (ICTP) were measured at onset of IDDM and at 3, 6 and 12 months. ICTP was in the normal range at onset of IDDM and decreased during the follow-up to reach a significant difference compared to controls after 3, 6 and 12 months of insulin treatment (P < 0.04). PICP concentrations increased significantly at 3 months (P = 0.05) compared to onset. At 3 and 12 months PICP values were significantly higher than those of control children (P = 0.04). Correlations were found between PICP concentrations and HbA1C and c-peptide at onset of diabetes (r = -0.45 and r = 0.47, respectively). Bone formation at onset of IDDM is not impaired; the introduction of insulin therapy, together with the achievement of a good metabolic control, determines an increase of bone matrix formation coupled with a decrease of bone resorption, that determines a positive balance of bone modeling.

Adolescent↗
PubMed1997

Frequency and correlates of severe hypoglycaemia in children and adolescents with diabetes mellitus.

UNLABELLED: Frequency and correlates of severe hypoglycaemia have been retrospectively analysed in a cohort of diabetic children and adolescents with median (range) age 14.5 (3.2-25.5) years followed from the onset of the disease by the same diabetic clinic. During the years 1992-1994, 53 of the 187 patients reported 74 hypoglycaemic episodes: the average frequency of hypoglycaemia during the 3 years surveyed was 14.9 episodes/ 100 patients per year. Frequency of hypoglycaemia decreased significantly with age (chi 2 = 24.1; P < 0.0001) and was independent of duration of diabetes. Glycosylated haemoglobin and insulin dose were similar in patients with and without hypoglycaemia, matched for age and duration of diabetes. One out of two hypoglycaemic episodes occurred during sleep and no explanation was available for 50% of episodes. CONCLUSION: In this study severe hypoglycaemia was more frequent in young children than in adolescents and was independent of metabolic control and insulin dose.

Adolescent↗