High 1-h glucose in youths with obesity as marker of prediabetes and cardiovascular risk

PURPOSE

Testing 1-h glucose (1HG) concentration during oral glucose tolerance test is cost-effective to identify individuals at risk of incident type 2 diabetes. Aim of the study was to define 1HG cutoffs diagnostic of incident impaired glucose tolerance (IGT) in youths with obesity, and to evaluate prevalence and association of cutoffs identified in the cohort and from the literature (133 and 155 mg/dl) to cardiovascular disease (CVD) in a population of youths with obesity.

METHODS

This is a longitudinal study of 154 youths to identify 1HG cutoffs, and cross-sectional study of 2295 youths to estimate prevalence of high 1HG and association to CVD. Receiver-operating characteristic curves (ROC) were used to establish 1HG cutoffs, and univariate regression analyses to test association of 1HG to blood pressure, lipids and aminotransferases.

RESULTS

ROC analysis identified the 1HG cutoff of 159 mg/dl as having diagnostic accuracy of IGT with area under the ROC 0.82 (95% CI 0.66-0.98), sensitivity 0.86% and specificity 0.79%. In the cross-sectional population, prevalence of high 1HG was 36% and 15% for 133 and 155 mg/dl cutoffs, respectively, and 17% for the 159 mg/dl value. All the examined cutoffs were significantly associated with worse lipid profile, liver function test, reduced insulin sensitivity, secretion and disposition index.

CONCLUSION

High 1HG is marker of persistent IGT and increased risk of metabolic abnormalities in youths. The 155 mg/dl cutoff is a convenient estimate in young people but longitudinal studies with retinopathy and overt diabetes as end points are advised to verify the 1HG cutoff with the best diagnostic accuracy.

Autoimmune polyendocrine syndrome type 1: an Italian survey on 158 patients

BACKGROUND

Autoimmune Polyglandular Syndrome type 1 (APS-1) is a rare recessive inherited disease, caused by AutoImmune Regulator (AIRE) gene mutations and characterized by three major manifestations: chronic mucocutaneous candidiasis (CMC), chronic hypoparathyroidism (CH) and Addison's disease (AD).

METHODS

Autoimmune conditions and associated autoantibodies (Abs) were analyzed in 158 Italian patients (103 females and 55 males; F/M 1.9/1) at the onset and during a follow-up of 23.7 ± 15.1 years. AIRE mutations were determined.

RESULTS

The prevalence of APS-1 was 2.6 cases/million (range 0.5-17 in different regions). At the onset 93% of patients presented with one or more components of the classical triad and 7% with other components. At the end of follow-up, 86.1% had CH, 77.2% AD, 74.7% CMC, 49.5% premature menopause, 29.7% autoimmune intestinal dysfunction, 27.8% autoimmune thyroid diseases, 25.9% autoimmune gastritis/pernicious anemia, 25.3% ectodermal dystrophy, 24% alopecia, 21.5% autoimmune hepatitis, 17% vitiligo, 13.3% cholelithiasis, 5.7% connective diseases, 4.4% asplenia, 2.5% celiac disease and 13.9% cancer. Overall, 991 diseases (6.3 diseases/patient) were found. Interferon-ω Abs (IFNωAbs) were positive in 91.1% of patients. Overall mortality was 14.6%. The AIRE mutation R139X was found in 21.3% of tested alleles, R257X in 11.8%, W78R in 11.4%, C322fsX372 in 8.8%, T16M in 6.2%, R203X in 4%, and A21V in 2.9%. Less frequent mutations were present in 12.9%, very rare in 9.6% while no mutations in 11% of the cases.

CONCLUSIONS

In Italy, APS-1 is a rare disorder presenting with the three major manifestations and associated with different AIRE gene mutations. IFNωAbs are markers of APS-1 and other organ-specific autoantibodies are markers of clinical, subclinical or potential autoimmune conditions.

Exercise-induced GH secretion is related to puberty

PURPOSE

Exercise represents a physiological stimulus that initiates the coordinated responses of hypothalamic-pituitary axis and sympathetic nervous system. Aims of the study were: 1) to analyze the response of GH, cortisol and prolactin to acute exercise in healthy children with normal GH response to stimulation tests 2) to evaluate the reliability of physical exercise as a screening test for GH secretion.

METHODS

Forty-four children (mean age 9.35 ± 2.69 years, range 4-13.7) underwent standardized Bruce's test on treadmill. Twenty-nine children were pre-pubertal (nine females and 20 males) and 15 children were pubertal (ten females and five males).

RESULTS

Exercise elicited a peak secretion of all the analyzed hormones. GH showed the highest mean percentage increase (558%), followed by prolactin (178%) and cortisol (23%). In 19/44 children (43.2%), GH peak did not reach the cut-off level of 8 ng/ml, considered as the normal GH response to stimulation tests. Despite a wide inter-individual variability, both GH peak and GH increase from baseline were higher in pubertal children than in pre-pubertal ones (GH peak: 13.49 ± 10.28 ng/ml versus 6.6 ± 4.09 ng/ml-p < 0.001; GH increase: 12.02 ± 10.30 ng/ml versus 5.28 ± 3.97 ng/ml-p < 0.001). The impact of puberty on both GH peak and GH increase was independent of sex, age, BMI SDS and VO₂max. No differences related to sex or pubertal status were found in cortisol and prolactin responses.

CONCLUSION

Exercise-induced GH secretion should not be considered a valuable screening tool in the diagnostic work-up of GH deficiency, due to the wide inter-individual variability in GH response. As described for standard GH stimulation tests, puberty represents the key factor that enhances GH secretion in healthy children.

Wrist circumference is a biomarker of adipose tissue dysfunction and cardiovascular risk in children with obesity

PURPOSE

To evaluate the relationship between wrist circumference, markers of adipose dysfunction, and cardiovascular risk in youths with obesity.

METHODS

In this cross-sectional study, we measured body mass composition by dual-energy X-ray absorptiometry, wrist circumference, waist-to-height ratio, fasting blood insulin, glucose, lipid profile, adiponectin, and leptin in 280 children with overweight/obesity and without diabetes (age: 7-18 years). Cardiovascular risk was estimated by "metabolic syndrome score" (MetS score).

RESULTS

Study participants had median [25th-75th percentile] wrist circumference of 17.5 [16.7-18.5] cm and waist-to-height ratio of 0.62 [0.59-0.67]. Lower adiponectin-leptin ratio was found among subjects in the upper 50th percentiles of wrist circumference [0.17 (0.09-0.36) vs. 0.38 (0.16-0.79); p < 0.001]. Wrist circumference was independently associated with MetS score (r = 0.5 p < 0.001). Among MetS score components, an independent association between wrist circumference HDLc, triglycerides, and systolic blood pressure was found (r = - 0.253 p < 0.001; r =+ 0.204 p < 0.001; r = + 0.403 p = < 0.001, respectively). The coefficient of determination for MetS score was nominally higher when considering wrist circumference as independent variable (Adj-R² = 0.30) then when considering body mass index SD (Adj-R² = 0.28), waist-to-height ratio (Adj-R² = 0.26) or truncal fat percentage (Adj-R² = 0.01). The addition of wrist circumference in age and gender adjusted models, accounting to any other anthropometric parameters, resulted in a significant improvement of the Adj-R² (p < 0.001 for all).

CONCLUSIONS

Our study shows that wrist circumference independently relates to adiponectin-leptin ratio and to the prediction of cardiovascular risk, suggesting it as an efficient and adjunctive anthropometric marker of cardiometabolic risk in children with obesity.

25OH vitamin D levels in pediatric patients affected by Prader-Willi syndrome

PURPOSE

Obesity, insulin resistance, and puberty seem to influence and been inversely associated with 25-hydroxy vitamin D (25OHD) levels. To our knowledge, a study on 25OHD in children and adolescents with Prader-Willi syndrome (PWS), a genetic form of obesity, is not yet available.

OBJECTIVE

To analyze the 25OHD values in pediatric PWS subjects in comparison with a control group (CNT), highlighting the possible correlations with IR, BMD, body composition, pubertal stage, and GH therapy (GHT).

METHODS

Auxological and laboratory parameters, HOMA-IR, Vitamin D status, and bone density and body composition by DEXA scan were analyzed in 52 PWS and 110 controls (CNT), gender-, age-, and BMI-SD matched. None of them was on calcium or vitamin D. 20 PWS were on growth hormone (GH) therapy and 32 were previously treated.

RESULTS AND CONCLUSION

Altogether, PWS had similar values of 25OHD compared to CNT.16 PWS (30.7%) and 27 CNT (24.5%) had low 25OHD levels (< 20 ng/ml) (p = NS). 25OHD of PWS on GHT were comparable to those previously treated. In both groups, univariate analysis showed a negative correlation between 25OHD and fat mass% (FM%). GH therapy and pubertal stage were positively correlated with bone parameters analyzed by DXA. Multivariate regression confirmed only FM% as negative predictor of 25HOD in PWS patients, as previously described. GHT does not seem to influence 25OHD in PWS.

CONCLUSION

Our data showed that PWS had similar values of 25OHD compared to CNT. As already described, FM seems to be the only parameter influencing 25OHD levels. Finally, GHT does not seem to influence 25OHD metabolism in PWS.

Growth hormone treatment improves final height and nutritional status of children with chronic kidney disease and growth deceleration

PURPOSE

Growth retardation is a common complication of chronic kidney disease (CKD) in children. Treatment with recombinant human growth hormone (rhGH) has been used to help short children with CKD to attain a height more in keeping with their age group, but the scientific evidence regarding the effect of rhGH on final height is scarce.

METHODS

Final heights of children with CKD receiving rhGH treatment (cases) were compared with final heights of a matched cohort of children with CKD that did not receive rhGH therapy (controls).

RESULTS

Sixty-eight rhGH-treated cases (44 boys) were compared with 92 untreated controls (60 boys). Mean duration of rhGH therapy was 4.2 ± 0.9 years; rhGH dose was 0.3 ± 0.07 mg/kg/week. Height SDS at baseline was lower in rhGH-treated patients than in controls (-2.00 ± 1.02 versus -0.96 ± 1.11, p < 0.001). Baseline height SDS was significantly lower than target height SDS in both groups. Height SDS significantly improved from baseline to final height attainment in rhGH-treated patients, while it slightly decreased in controls (mean SDS variation 0.69 ± 1.05 in rhGH-treated cases versus -0.15 ± 1.2 in controls). Final height SDS was -1.25 ± 1.06 in rhGH-treated cases and -1.06 ± 1.17 in controls (p = 0.29). Target adjusted final height SDS was -0.91 ± 1.03 in rhGH-treated cases and -0.61 ± 1.17 in controls (p = 0.1).

CONCLUSIONS

Long-term rhGH therapy is able to reduce the linear growth deceleration of children with CKD, and ultimately to improve their final height, reducing the difference with target height.

Family history and ethnicity influencing clinical presentation of type 1 diabetes in childhood

BACKGROUND

A different clinical presentation of type 1 diabetes (T1DM) could be supposed in children belonging to different ethnicities, with or without family history of autoimmunity.

OBJECTIVE

This study investigates the effect of ethnicity and family history of T1DM on clinical characteristics at presentation in a group of T1DM children.

METHODS

One hundred ninety-six T1DM children <18 years, consecutively diagnosed during the years 2011-2014, were studied including 91 % of Caucasians of Italian ancestry and 9 % of non-Caucasian origin.

RESULTS

Children with 1st or 2nd degree relatives affected by T1DM were younger at disease onset (p = 0.005) and showed lower HbA1C levels (p = 0.002), and higher IAA levels (p = 0.01). Non-Caucasian children were younger at disease onset (p = 0.029), and showed more severe hyperglycemia (p = 0.008) and ketoacidosis (pH p < 0.001). HbA1C levels were negatively related to positive family history of T1DM (p = 0.01), fasting C-peptide levels (p = 0.003), IAA levels (p = 0.03), and IA-2 levels (p = 0.003). The level of pH was positively influenced by fasting C-peptide (p = 0.004), and negatively impacted by C-reactive protein (p = 0.01) and non-Caucasian ethnicity (p = 0.03).

CONCLUSION

The milder metabolic decompensation in children with a positive family history of T1DM is probably explained by the awareness of the families in terms of early symptoms of T1DM, while the younger age at onset and the higher levels of autoantibodies may suggest a stronger genetic susceptibility, associated with a more aggressive autoimmune process. The younger age in non-Caucasian children is probably explained by the higher genetic susceptibility in subjects belonging to ethnic groups with a low T1DM incidence. Social aspects and poor living conditions probably predominate in determining the increased severity of metabolic decompensation at onset in children from non-Caucasian ethnicities.

Early retesting by GHRH + arginine test shows normal GH response in most children with idiopathic GH deficiency

PURPOSE

Most children with idiopathic isolated GH deficiency (IGHD) normalize GH response to stimulation tests when retested at the completion of growth. The objective of this study was to test the effectiveness of early retesting in challenging the diagnosis of idiopathic IGHD and critically review the diagnostic workup leading to this diagnosis in children with short stature.

METHODS

We cross-sectionally retested 38 children with idiopathic IGHD and still on GH treatment. The initial diagnosis of idiopathic IGHD was based on subnormal GH responses to two stimulation tests and normal brain imaging or minor/nonspecific findings at magnetic resonance. The GH response normalization at retesting was considered as the main outcome measure. Clinical features of children who were falsely classified as idiopathic IGHD based on first GH testing were retrospectively analyzed.

RESULTS

GH secretion was normal in 36/38 children (95%). Two children showed slightly reduced peak GH responses and normal IGF-I levels. Fourteen children underwent GH retesting before puberty, 24 children during puberty.

CONCLUSION

The diagnostic process should be improved to minimize the rate of false positive at GH testing and, in case of unsatisfactory response to GH treatment, the diagnosis of isolated idiopathic GHD should be challenged with early retesting.

Metabolic syndrome and diabetes mellitus in childhood cancer survivors

BACKGROUND

The survival of children with cancer has grown considerably in recent years resulting in a marked increase of endocrine complications. increasingly recognized problems are metabolic syndrome and diabetes mellitus.

DATA SOURCES

We critically analysed the most recent literature about the prevalence and molecular mechanisms of metabolic dysregulation and long-term cardio-metabolic risk in this population.

RESULTS

Hypothalamic irradiation determines growth hormone deficiency and hypogonadism; moreover it is able to disrupt the appetite regulating centre leading to hyperphagia and progressive obesity. These conditions determine an insulin resistant state, contributing to the development of metabolic syndrome and diabetes mellitus. Irradiation and/or chemotherapy may lead to an insulin secretory defect through a direct damage of pancreatic beta cells.

CONCLUSION

Metabolic syndrome and diabetes mellitus represent increasingly recognized long-term complications of childhood cancer treatment. The different impact of insulin resistance and secretory defects on the onset and progression of metabolic syndrome and diabetes mellitus remains unclear.

Minimal incidence of neonatal/infancy onset diabetes in Italy is 1:90,000 live births

Until early 2000, permanent and transient neonatal diabetes mellitus (NDM), defined as diabetes with onset within 6 weeks from birth that requires insulin therapy for at least 2 weeks, were considered exceedingly rare conditions, with a global incidence of 1:500,000-1:400,000 live births. The new definition of NDM recently adopted, that includes patients with diabetes onset within 6 months of age, has prompted studies that have set the incidence of the permanent form alone between 1:210,000 and 1:260,000 live births. Aim of the present work was to ascertain the incidence of NDM (i.e. permanent + transient form) in Italy for years 2005-2010. Patients referred to the Italian reference laboratory for NDM between years 2005 and 2010 and screened for mutations in common NDM genes (KCNJ11, ABCC8, and INS) and for uniparental isodisomy of chromosome 6 (UDP6) were reviewed. A questionnaire aimed at identifying NDM cases investigated in other laboratories was sent to 54 Italian reference centers for pediatric diabetes. Twenty-seven patients with NDM born between 2005 and 2010 were referred to the reference laboratory. In this group, a mutation of either KCNJ11, ABCC8 or INS was found in 18 patients, and a case with UDP6 was identified. Questionnaires revealed 4 additional cases with transient neonatal diabetes due to UDP6. Incidence of NDM was calculated at 1:90,000 (CI: 1:63,000-1:132,000) live births. Thus, with the definition currently in use, about 6 new cases with NDM are expected to be born in Italy each year.

Receptor binding mode and pharmacological characterization of a potent and selective dual CXCR1/CXCR2 non-competitive allosteric inhibitor

BACKGROUND AND PURPOSE

DF 2156A is a new dual inhibitor of IL-8 receptors CXCR1 and CXCR2 with an optimal pharmacokinetic profile. We characterized its binding mode, molecular mechanism of action and selectivity, and evaluated its therapeutic potential.

EXPERIMENTAL APPROACH

The binding mode, molecular mechanism of action and selectivity were investigated using chemotaxis of L1.2 transfectants and human leucocytes, in addition to radioligand and [(35) S]-GTPγS binding approaches. The therapeutic potential of DF 2156A was evaluated in acute (liver ischaemia and reperfusion) and chronic (sponge-induced angiogenesis) experimental models of inflammation.

KEY RESULTS

A network of polar interactions stabilized by a direct ionic bond between DF 2156A and Lys(99) on CXCR1 and the non-conserved residue Asp(293) on CXCR2 are the key determinants of DF 2156A binding. DF 2156A acted as a non-competitive allosteric inhibitor blocking the signal transduction leading to chemotaxis without altering the binding affinity of natural ligands. DF 2156A effectively and selectively inhibited CXCR1/CXCR2-mediated chemotaxis of L1.2 transfectants and leucocytes. In a murine model of sponge-induced angiogenesis, DF 2156A reduced leucocyte influx, TNF-α production and neovessel formation. In vitro, DF 2156A prevented proliferation, migration and capillary-like organization of HUVECs in response to human IL-8. In a rat model of liver ischaemia and reperfusion (I/R) injury, DF 2156A decreased PMN and monocyte-macrophage infiltration and associated hepatocellular injury.

CONCLUSION AND IMPLICATIONS

DF 2156A is a non-competitive allosteric inhibitor of both IL-8 receptors CXCR1 and CXCR2. It prevented experimental angiogenesis and hepatic I/R injury in vivo and, therefore, has therapeutic potential for acute and chronic inflammatory diseases.

Is subclinical adrenal failure in adrenoleukodystrophy/adrenomyeloneuropathy reversible?

BACKGROUND

X-linked adrenoleukodystrophy/adrenomieloneuropathy (ALD/AMN) is a progressive neurodegenerative disorder due to mutations in the ABCD1 gene encoding the ABC transporter ALDP. Mutations in ALDP impair peroxisomal β-oxidation of very long chain fatty acids (VLCFA), resulting in elevated levels of VLCFA in plasma, nervous system, and adrenals. Lorenzo's oil, combined with VLCFA- poor diet, normalizes plasma VLCFA within 1 month, but it does not prevent the progression of pre-existing neurological symptoms. No previous study analyzed the effect of Lorenzo's oil therapy on adrenal function.

AIM

To investigate short-term effects of Lorenzo's oil, combined with VLCFA- poor diet, on adrenal function of AMN patients with early subclinical signs of adrenal failure.

SUBJECTS AND METHODS

Seven AMN subjects underwent VLCFA-restricted diet combined with Lorenzo's oil (45 ml/day po), without steroid therapy, for 6 months.

RESULTS

All patients had elevated ACTH at baseline, and a significant reduction was evident after 6 months (median ACTH at baseline: 1300 pg/ml, range: 720- 2100; median ACTH at 6 months: 186 pg/ml, range: 109-320, p: 0.0156). Cortisol was normal both at baseline and after 6 months. VLCFA dropped in all patients during the 6- month follow-up, and no patient required glucocorticoid replacement therapy.

CONCLUSIONS

Adrenal insufficiency in ALD/AMN is probably due to a defective adrenal response to ACTH, related to VLCFA accumulation with progressive disruption of the adrenal cell membrane functions. In an early phase, Lorenzo's oil therapy may be able to improve VLCFA clearance and restore a normal ACTH receptor activity, and hypoadrenalism may be potentially reversible.

Permanent diabetes during the first year of life: multiple gene screening in 54 patients

AIMS/HYPOTHESIS

The aim of this study was to investigate the genetic aetiology of permanent diabetes mellitus with onset in the first 12 months of age.

METHODS

We studied 46 probands with permanent, insulin-requiring diabetes with onset within the first 6 months of life (permanent neonatal diabetes mellitus [PNDM]/monogenic diabetes of infancy [MDI]) (group 1) and eight participants with diabetes diagnosed between 7 and 12 months of age (group 2). KCNJ11, INS and ABCC8 genes were sequentially sequenced in all patients. For those who were negative in the initial screening, we examined ERN1, CHGA, CHGB and NKX6-1 genes and, in selected probands, CACNA1C, GCK, FOXP3, NEUROG3 and CDK4. The incidence rate for PNDM/MDI was calculated using a database of Italian patients collected from 1995 to 2009.

RESULTS

In group 1 we found mutations in KCNJ11, INS and ABCC8 genes in 23 (50%), 9 (19.5%) and 4 (8.6%) patients respectively, and a single homozygous mutation in GCK (2.1%). In group 2, we identified one incidence of a KCNJ11 mutation. No genetic defects were detected in other loci. The incidence rate of PNDM/MDI in Italy is estimated to be 1:210,287.

CONCLUSIONS/INTERPRETATION

Genetic mutations were identified in ~75% of non-consanguineous probands with PNDM/MDI, using sequential screening of KCNJ11, INS and ABCC8 genes in infants diagnosed within the first 6 months of age. This percentage decreased to 12% in those with diabetes diagnosed between 7 and 12 months. Patients belonging to the latter group may either carry mutations in genes different from those commonly found in PNDM/MDI or have developed an early-onset form of autoimmune diabetes.

Dumping syndrome: an unusual cause of severe hyperinsulinemic hypoglycemia in neurologically impaired children with gastrostomy

This paper describes severe hyperinsulinemic hypoglycemia during bolus enteral feeding in two neurologically impaired children. Both children were affected by dysphagia with swallowing difficulties; caloric intake was inadequate. For these reasons, percutaneous endoscopic gastrostomy had been positioned during the first months of life. In one patient due to persisting vomiting, after a few months, a gastrojejunal tube (PEG-J) was inserted. Hypoglycemia was revealed by routine blood tests, without evidence of specific symptoms. Continuous subcutaneous glucose monitoring showed wide glucose excursions, ranging from hypoglycemia to hyperglycemia. Extremely high levels of insulin were detected at the time of hypoglycemia. A diagnosis of dumping syndrome (DS) was suspected in both children. In the child with PEG, the tip of the gastrostomy catheter was found to be lying in the bulbus duodeni. Once this had been pulled back, hypoglycemic episodes disappeared. The child with PEG-J needed continuous enteral feeding to reach a normal glucose balance. DS is a relatively common complication in children with gastrostomy, but extremely irregular glucose levels, ranging from hypoglycemia to hyperglycemia, and increased insulin secretion had not been previously demonstrated. The incidence of DS is probably underestimated in children receiving enteral feeding for neurological impairment. In these patients intensive monitoring of blood glucose levels should be performed to calibrate meals. Repeated underestimated hypoglycemic episodes could worsen neurological damage and cause a deterioration in clinical conditions.

Computer use, free time activities and metabolic control in patients with type 1 diabetes

We investigated the influence of computer's use on metabolic control in 115 patients with type 1 diabetes (DM1). Multiple linear regression showed that HbA1c% was not related to age, DM1 duration, TV watching or computer use but was independently and negatively related to the weekly hours spent on physical exercise.

Growth hormone response to physical exercise in growing patients with classic congenital adrenal hyperplasia

Glucocorticoid over-treatment in children with congenital adrenal hyperplasia (CAH) may suppress GH secretion and growth. Aims of our study were: 1) to evaluate post-exercise GH response in patients affected by CAH due to 21-hydroxylase deficiency, in comparison with a group of healthy subjects; 2) to investigate the relationship between the hormonal markers of adequate steroid therapy and GH secretion. We evaluated GH secretion every 6 months in 20 young CAH patients (8 girls, 12 boys). Mean follow-up was 4.6+/-0.9 yr (107 tests performed, 5.35+/-2.05 repeated tests for each patient). Forty-four healthy subjects (25 boys, 19 girls) were selected as a control group. The range of post-exercise GH peak was very wide, but medians were not statistically different in cases and controls (p=0.570). Multivariate analysis showed that post-exercise GH peak was not related to age (p=0.743), gender (p=0.296) or pubertal status (p=0.440) in both groups. GH increase from baseline showed the same behavior (p=0.265, 0.639 and 0.105, respectively). In CAH patients, GH peak and GH increase were both directly related to 17-OH-progesterone levels [GH peak: p=0.032--95% confidence interval (CI): 0.01-0.34--beta=0.18; GH increase: p=0.008--95% CI: 0.06-0.35--beta=0.20]. The negative effect of glucocorticoid therapy on GH secretion seems to be dominant in CAH. The most effective approach to adjust treatment remains monitoring growth. Relying on hormonal markers to adequate steroid therapy may result in over-treatment, GH suppression, and finally poor linear growth.

Young elite athletes of different sport disciplines present with an increase in pulsatile secretion of growth hormone compared with non-elite athletes and sedentary subjects

Acute exercise is a well-known stimulus for GH secretion but the effect of chronic training on GH secretion still remains equivocal. The aim of our study was to analyse spontaneous pulsatile GH secretion (during a period of 2 hours in the morning) in a group of young elite athletes (EA) compared with non-elite athletes (NEA), and sedentary subjects (SS). Mean and peak GH levels proved significantly higher in EA than in NEA and SS (p=0.0004 and p<0.0001, respectively). The same differences in mean and peak GH levels were also demonstrated in males and females when considered separately (males: p=0.0062 and p=0.0025; females: p=0.0056 and p=0.0032). In addition, GH levels (mean and peak) were higher in females than in males in SS while no differences were demonstrated between the 2 sexes in the EA and NEA groups. IGF-I levels were within the normal range for age in all the subjects with no difference between the 3 groups. Body mass index (BMI) exhibited no difference between groups, while EA showed higher lean mass (p=0.0063) and lower fat mass (p=0.0139) than NEA and SS measured by dual-energy x-ray absorptiometry. A strong positive correlation between GH levels (mean and peak) and hours of training a week was demonstrated (p=0.0101; r2=0.1184; p=0.0022; r2=0.1640, respectively). In conclusion, GH levels were higher in EA than NEA and SS without any modification of IGF-I levels; a strong positive correlation was present between GH levels and intensity of training. An increase in the knowledge of the effect of chronic training on GH secretion could improve the training programme to elicit the greatest exercise- induced GH response.

Blockade of the chemokine receptor CXCR2 ameliorates adjuvant-induced arthritis in rats

BACKGROUND AND PURPOSE

Chemokine receptors CXCR1 and CXCR2 may mediate influx of neutrophils in models of acute and chronic inflammation. The potential benefits of oral administration of a CXCR1/2 inhibitor, DF 2162, in adjuvant-induced polyarthritis (AIA) were investigated.

EXPERIMENTAL APPROACH

A model of AIA in rats was used to compare the therapeutic effects of the treatment with DF2162, anti-TNF or anti-CINC-1 antibodies on joint inflammation and local production of cytokines and chemokines.

KEY RESULTS

DF2162 prevented chemotaxis of rat and human neutrophils induced by chemokines acting on CXCR1/2. DF2162 was orally bioavailable and metabolized to two major metabolites. Only metabolite 1 retained CXCR1/2 blocking activity. Treatment with DF2162 (15 mg kg(-1), twice daily) or metabolite 1, but not metabolite 2, starting on day 10 after arthritis induction diminished histological score, the increase in paw volume, neutrophil influx and local production of TNF, IL-1beta, CCL2 and CCL5. The effects of DF2162 were similar to those of anti-TNF, and more effective than those of anti-CINC-1, antibodies. DF2162 prevented disease progression even when started 13 days after arthritis induction.

CONCLUSIONS AND IMPLICATIONS

DF 2162, a novel orally-active non-competitive allosteric inhibitor of CXCR1 and CXCR2, significantly ameliorates AIA in rats, an effect quantitatively and qualitatively similar to those of anti-TNF antibody treatment. These findings highlight the contribution of CXCR2 in the pathophysiology of AIA and suggest that blockade of CXCR1/2 may be a valid therapeutic target for further studies aiming at the development of new drugs for treatment of rheumatoid arthritis.

Basal insulin supplementation in Type 1 diabetic children: a long-term comparative observational study between continuous subcutaneous insulin infusion and glargine insulin

No long-term data are available on the efficacy of glargine insulin in comparison with continuous sc insulin infusion (CSII) in children and adolescents affected by Type 1 diabetes (T1D). Our aim was to compare the 2-yr efficacy of the 2 insulin approaches, in order to know how to best supply basal insulin in these patients. Thirty-six 9 to 18-yr-old consecutive children with at least 3 yr previous T1D diagnosis were enrolled. As part of routine clinical care, the patients consecutively changed their previous insulin scheme (isophane insulin at bedtime and human regular insulin at meals) and were randomly selected in order to receive either multiple daily injections (MDI) treatment with once-daily glargine and human regular insulin at meals, or CSII with aspart or lispro insulin. Both groups showed a significant decrease in glycosylated hemoglobin (HbA1c) values during the 1st year of therapy, though only in the CSII treated children was the decrease also observed during the 2nd year. The overall insulin requirement significantly decreased only in the CSII group and exclusively during the 1st year, while no significant differences were observed concerning body mass index SD score, severe hypoglycemic episodes and basal insulin supplementation. The work illustrates the first long-term study comparing the efficacy of CSII to MDI using glargine as basal insulin in children. Only with CSII were better HbA1c values obtained for prolonged periods of time, so that CSII might be considered the gold standard of intensive insulin therapy also for long-term follow-ups.

Metabolic factors affecting residual beta cell function assessed by C-peptide secretion in patients with newly diagnosed type 1 diabetes

BACKGROUND

In recent onset of type 1 diabetes, the residual beta cell function, assessed by baseline and/or stimulated C-peptide secretion, can be a useful parameter to establish the extension of beta cell destruction. How metabolic parameters at diagnosis influence residual C-peptide secretion is not well established.

PATIENTS AND METHODS

We analyzed 553 consecutive patients with recent onset (<4 weeks) of type 1 diabetes (250 females and 303 males, mean age 15+/-8 years). Baseline and stimulated C-peptide by i.v. glucagon were evaluated using a highly sensitive radio-immunoassay. Metabolic parameters including blood glucose, HbA1c, insulin dose, and BMI were also evaluated.

RESULTS

Baseline and stimulated C-peptide were 0.26+/-0.22 and 0.47+/-0.38 nmol/l and correlated positively with age (p<0.001). There was no significant correlation between C-peptide and blood glucose at diagnosis. BMI was positively correlated with both baseline and stimulated C-peptide secretion (p<0.001). By contrast, HbA1c levels inversely correlated with both baseline and stimulated C-peptide secretion (p<0.001).

CONCLUSION

In type 1 diabetes at diagnosis, baseline and stimulated C-peptide are higher in pubertal and young adult patients compared with pre-pubertal patients suggesting that such parameter can be used as an end point marker for studies aimed at protecting and/or restoring beta cells in patients with substantial beta cell function. High levels of HbA1c and lower BMI are dependent variables of C-peptide values.

The effects of calcitriol and nicotinamide on residual pancreatic beta-cell function in patients with recent-onset Type 1 diabetes (IMDIAB XI)

BACKGROUND

A number of recent studies underline the importance of vitamin D in the pathogenesis of Type 1 diabetes (T1D).

AIMS

The aim of this study was to investigate whether supplementation with the active form of vitamin D (calcitriol) in subjects with recent-onset T1D protects residual pancreatic beta-cell function and improves glycaemic control (HbA(1c) and insulin requirement).

METHODS

In this open-label randomized trial, 70 subjects with recent-onset T1D, mean age 13.6 years +/- 7.6 sd were randomized to calcitriol (0.25 microg on alternate days) or nicotinamide (25 mg/kg daily) and followed up for 1 year. Intensive insulin therapy was implemented with three daily injections of regular insulin + NPH insulin at bedtime.

RESULTS

No significant differences were observed between calcitriol and nicotinamide groups in respect of baseline/stimulated C-peptide or HbA1c 1 year after diagnosis, but the insulin dose at 3 and 6 months was significantly reduced in the calcitriol group.

CONCLUSIONS

At the dosage used, calcitriol has a modest effect on residual pancreatic beta-cell function and only temporarily reduces the insulin dose.

Clinical effects of early treatment with insulin glargine in patients with cystic fibrosis and impaired glucose tolerance

Diabetes mellitus is an increasing complication of cystic fibrosis (CF), as a result of the improved life expectancy. There is clear association between diabetes and increased morbidity and mortality. Lung function and clinical status deteriorate up to 2-4 yr before the diagnosis of CF-related diabetes (CFRD). The aim of our study was to evaluate the effects, on glucose homeostasis and clinical status, of the early treatment with insulin glargine in CF patients with impaired glucose tolerance (IGT). We selected six subjects with IGT diagnosed at oral glucose tolerance test (OGTT). Median age was 18.12 yr (range 9.2-27.8). Insulin glargine was administered at the median dosage of 0.3 U/kg/day (range 0.2-0.5). After the initial adjustment of the dosage, no patient manifested hypoglycemia during treatment. Median glycosylated hemoglobin (HbA1c) did not show any significant variation during treatment: it was 5.9% at baseline (range 5.5-6.2) and 6.1% (range 5.0-6.7) at the end of follow-up (p=0.496). Median body mass index (BMI) z-score significantly increased during treatment, from -0.95 (range -3.2-+0.6) at baseline to -0.5. (range -3.0-+0.9) at the end of follow-up (p=0.026). Lung function, measured by median forced expiratory volume in the first second (FEV1%), showed a mild but significant improvement during insulin treatment. It was 72.7% at baseline (range 41.5-98.4) and 76.7% (range 42.0-106.8) at the end of follow-up (p=0.027). No significant variation was found between the number of hospitalizations for clinical exacerbation (no./patient/yr) in the last 2 yr before treatment and during follow-up. Median number at baseline was 1.95/patient/yr (range 1-3) and 2.0/patient/yr (range 1-3) at follow-up (p=0.715). Our data seem to indicate that early insulin therapy can be safe, no patient manifested hypoglycemia or other adverse effects during treatment. Insulin is an anabolic hormone implicated in both lipid and protein metabolism. The appearance of IGT out of infections can indicate an early insulin deficiency, with a potential impact on the nutritional and clinical status of the patient, even before the appearance of overt diabetes. Larger controlled trials are necessary to verify if early insulin therapy is able to reduce the deterioration of nutritional status and lung function associated with the onset of IGT.

Plasma levels of adrenomedullin in patients with adrenoleukodystrophy/adrenomyeloneuropathy

BACKGROUND/AIMS

Adrenomedullin (AM) is a recently purified hypotensive peptide and its encoding gene has been sequenced from a human pheochromocytoma. High levels of AM have been shown in Addison's disease (AD). X-linked adrenoleukodystrophy/adrenomyeloneuropathy (ALD/AMN) is a peculiar adrenal insufficiency due to an accumulation of very-long chain fatty acid in adrenal cells and it is very often associated with a devastating demyelination of the central nervous system.

METHODS

We studied the AM plasma levels of 22 patients with ALD/AMN (18 with hypoadrenalism, ALDa, and 4 with normal adrenal function, ALDb) and compared them with 18 males with classical AD and 16 normal male subjects. All patients with hyposurrenalism were studied before treatment with hydrocortisone.

RESULTS

Both patients with ALD/AMN and AD showed increased levels of AM and all of them showed a significant difference from the control group (p < 0.0001). The plasma renin activity was higher in all patient groups than in the control group (p <0.001 ALDa, ALDb and AD vs. control group). The aldosterone levels were higher in ALDa and ALDb groups than AD (ALDa vs. AD p < 0.01; ALDb vs. control group p < 0.05; AD vs. controls p < 0.01). ACTH plasma levels were higher in ALDa and AD than ALDb and the control group (ALDa vs. AD not significant while ALDa and AD vs. control p <0.0001).

CONCLUSIONS

Our data indicate that plasma AM levels in ALDa, ALDb and AD are higher than controls. These results were previously described in untreated AD. While classical AD patients show complete adrenal insufficiency (both mineralocorticoid and glucocorticoid defects), ALD/AMN patients show a less compromised glomerular function, indicating that AM is not completely correlated with mineralocorticoid insufficiency, and that the exact mechanism responsible for the increased AM levels in ALD/AMN is still unknown.

XK-aprosencephaly and related entities

We offer further biological characterization of the XK atelen/aprosencephaly syndrome in two infants, one with prolonged survival, the other presenting prenatally with apparent hydranencephaly and an orbital tumor (OS). Familial occurrence in the former born to presumably nonconsanguineous Lybian parents may represent parental germinal mosaicism or autosomal recessive inheritance. Both had apparently normal chromosomes; however, the Lybian infant had slightly increased induced chromosome breakage suggesting that this rare multiple congenital anomalies syndrome may involve a DNA repair defect. Virtual absence of atelen/aprosencephalic structures may lead to an arthrogryposis-like prenatal movement disorder. The orbital tumor in the Utah infant consisted of dystopic neural tissue compressing a rudimentary globe and was connected by a thin bridge of neural tissue to the small mass of disorganized brain tissue usually found in atelen/aprosencephalic infants and fetuses. No evidence of an encephaloclastic process was found in the autopsied Utah infant.

Targeting C5a: Recent Advances in Drug Discovery

Activation of complement via the innate and adaptive immune system is vital to the body's defences in fighting infections. Unregulated complement activation is likely to play a crucial role in the pathogenesis of several diseases including psoriasis, adult (acute) respiratory distress syndrome (ARDS), bullous pemphigoid (BP), rheumatoid arthritis (RA) and ischemia-reperfusion (I/R) injury. The 74 amino acid peptide C5a is released after complement activation at sites of inflammation and is a potent chemoattractant for neutrophils, basophils, eosinophils, leukocytes, monocytes and macrophages. Recombinant proteins and humanized anti-C5 antibodies have been recently developed for blocking specific proteins of the complement system bringing renewed attention towards complement inhibition. Pharmacological studies have been highlighting the complement fragment C5a as an interesting target for the management of complement mediated diseases. Specific inhibition of C5a biological activity could gain therapeutic benefit without affecting the protective immune response. In the last few years several peptide and non-peptide antagonists of C5a have been discovered and tested in relevant pharmacological models; the availability of orally active compounds is rapidly helping to delineate the precise role of C5a in immunoinflammatory disorders. Moreover, mutagenesis data for the C5a/C5a receptor (C5aR) couple make C5aR a valuable model for mechanistic studies of peptidergic G-protein coupled receptors (GPCRs). The aim of this review is to outline the recent advances in C5a inhibition, especially highlighting the value of a multidisciplinary integrated approach in drug discovery.

Voiding dysfunction in x-linked adrenoleukodystrophy: symptom score and urodynamic findings

PURPOSE

Adrenoleukodystrophy is an x-linked genetic disorder characterized by the breakdown of the myelin sheath surrounding nerve cells in the brain and progressive dysfunction of the adrenal gland with 6 possible phenotypes. Lower urinary tract symptoms affect the quality of life of these patients but only sporadic cases have been previously studied by urodynamics. We report to our knowledge the first series in the literature looking at the prevalent pattern.

MATERIALS AND METHODS

A total of 14 children and adults 8 to 53 years old (average age 30) with different phenotypes were referred for evaluation. Of the patients 6 had adrenomyeloneuropathy without cerebral involvement (C-) 3 had the adult cerebral form, 3 had the childhood cerebral form, 1 had cerebral involvement (C+) and 1 was asymptomatic. All patients were submitted to a screening protocol, consisting of the self-administered short form questionnaire International Conference on Incontinence Questionnaire-Short Form (ICIQ-SF) and a 3-day voiding diary. Patients were divided in group 1-no urinary symptoms, ICIQ-SF score 0 and no further investigation (3); group 2-frequency/urgency, ICIQ-SF score 1 to 5, uroflowmetry and post-voiding residual urine (4); and group 3-voiding symptoms and incontinence, ICIQ-SF score greater than 5, standard urodynamic examination (7).

RESULTS

A neurogenic overactive bladder was the prevalent urodynamic finding (6 of 7 patients), while hypocontractility was found in 1 case.

CONCLUSIONS

Vesicosphincteric dysfunction can be explained by spinal and/or cerebral involvement in the different neurological forms of adrenoleukodystrophy. Attempts at treatment with anticholinergics and neuromodulation in 4 of our patients provided temporary benefit with clear subjective amelioration of symptoms and improved quality of life.

A randomized trial of nicotinamide and vitamin E in children with recent onset type 1 diabetes (IMDIAB IX)

OBJECTIVE

Various adjuvant therapies have been introduced along with intensive insulin therapy in patients with recent onset type 1 diabetes. Nicotinamide (NA), administered at diagnosis of the disease, can have beneficial effects on the clinical remission rate, improve metabolic control and preserve or slightly increase beta-cell function, probably by reducing toxicity due to free oxygen radicals. Vitamin E, a known antioxidant, inhibits lipid peroxidation; this can lead to protection of islet beta cells from the combined effects of interleukin 1, tumor necrosis factor and gamma interferon. The aim of the present study was to investigate whether the addition of vitamin E to NA could improve metabolic control and the residual beta-cell function, as measured by C-peptide secretion, in children and adolescents with recent onset type 1 diabetes; patients were followed-up for 2 years after diagnosis.

PATIENTS AND STUDY DESIGN

Recent onset type 1 diabetes patients (n=64, mean age 8.8 years) were recruited by participating centres of the IMDIAB group. Thirty-two patients were randomized to NA (25 mg/kg body weight) plus vitamin E (15 mg/kg body weight); 32 patients acted as controls and received NA only at the same dose as above. Intensive insulin therapy was applied to both treatment groups.

RESULTS

There were three drop outs during the 2-year follow-up period. Overall, patients assigned to the NA+vitamin E group or the NA group did not significantly differ in terms of glycated hemoglobin (HbA1c) levels, insulin requirement or baseline C-peptide secretion. Patients diagnosed at an age of less than 9 years showed significantly reduced C-peptide levels compared with those aged over 9 years at diagnosis and at the 2-year follow-up but there were no differences between the NA and NA+vitamin E treated groups. However at 6 months, patients over 9 years of age treated with NA+vitamin E showed significantly higher C-peptide compared with the NA group (P<0.003). In both age groups and in the different treatment groups, C-peptide levels found at diagnosis were preserved 2 years later.

CONCLUSIONS

The use of NA alone, or in combination with vitamin E, along with intensive insulin therapy is able to preserve baseline C-peptide secretion for up to 2 years after diagnosis. This finding is of particular interest for pre-pubertal children with type 1 diabetes and has never been reported before.

Maintenance of a normal meal-induced decrease in plasma ghrelin levels in children with Prader-Willi syndrome

Ghrelin is a 28-amino acid peptide recently identified in the stomach as the endogenous ligand for the growth hormone secretagogue receptor (GHS-R1a). Ghrelin is a potent stimulator of GH secretion. It was recently shown that circulating ghrelin levels in humans rise shortly before and fall shortly after every meal, and that ghrelin administration increases voluntary food intake. The hypothesis that ghrelin hypersecretion might contribute to genetic obesity has never been investigated. In this context, Prader-Willi syndrome is the most common form of human syndromic obesity. As ghrelin affects appetite as well as GH secretion and both are abnormal in PWS, it has been surmised that these alterations might be due to ghrelin dysregulation. The aim of the study was to investigate whether ghrelin is suppressed by the meals differently in PWS children than in PWS adults. Overnight circulating fasting ghrelin levels and ghrelin levels 120 min after breakfast were assayed in 7 PWS children (10.2 +/- 1.7 yr), 7 subjects with morbid obesity (10.3 +/- 1.3 yr), and 5 normal controls (8.4 +/- 1.4 yr). Because of the data spread, no statistical difference was observed in fasting ghrelin levels between PWS and control children (p = NS); anyway, fasting ghrelin levels were significantly lower in obese children than in the other groups (p < 0.05 vs. control and PWS children). Ghrelin levels were slightly suppressed by the meal in control subjects (mean fasting ghrelin: 160.2 +/- 82 pg/ml; after the meal, 141.2 +/- 57 pg/ml, p = NS); the meal failed to suppress ghrelin levels in obese children (mean fasting ghrelin: 126.4 +/- 8.5 pg/ml; after the meal, 119.1 +/- 8.3 pg/ml, p = NS). Interestingly, the meal markedly suppressed ghrelin levels in PWS children (mean fasting ghrelin: 229.5 +/- 70.4 pg/ml; after the meal, 155.8 +/- 34.2 pg/ml, p < 0.01). In conclusion, since a lack of decrease in circulating ghrelin induced by the meal was previously reported in PWS adults, the finding of a meal-induced decrease in ghrelin levels in our population of young PWS would imply that the regulation of the ghrelin system involved in the orexigenic effects of the peptide is operative during childhood, although it progressively deteriorates and is absent in adulthood when hyperphagia and obesity progressively worsen.

Selective inhibition of interleukin-8-induced neutrophil chemotaxis by ketoprofen isomers

Although it is commonly accepted that the anti-inflammatory effect of nonsteroidal anti-inflammatory drugs (NSAIDs) is mainly associated to their ability to inhibit the cyclooxygenase (COX) enzyme system, several results indicate that non-COX mechanisms could be important in the therapeutical effect of these drugs. The aim of this study was to define if NSAIDs could exert, at least in part, their anti-inflammatory effect by inhibiting the activities of human polymorphonuclear leukocytes (PMNs) triggered by chemotactic stimuli and, if so, to understand the relationship of this effect with COX inhibition. A unique opportunity to dissociate the inhibition of prostaglandin (PG) synthesis from other therapeutical properties of NSAIDs is constituted by ketoprofen isomers being the S-isomer 100 time more potent than R-isomer on COX inhibition. Our results show that R- and S-ketoprofen, independently of their potency as PG inhibitors, proved very efficacious in selective inhibition of interleukin-8 (IL-8) chemotaxis. Inhibition of IL-8 chemotaxis was not restricted to ketoprofen isomer as it could be observed also with drugs belonging to different classes of NSAIDs and it was obtained at drug concentration superimposable to plasma levels after therapeutic administration in patients. Reduction of IL-8 migration by ketoprofen isomers was paralleled by selective inhibition of PMN response in terms of intracellular calcium concentration ([Ca(2+)]i) increase and extracellular signal regulated kinase(ERK)-2 activation, two intracellular mediators reported to be critical for PMN activities. It is concluded that inhibition of IL-8 chemotaxis could represent a new clinical target for ketoprofen isomers and, in fact, contribute to the anti-inflammatory activity of NSAIDs.

Intradermal skin test with diabetes specific antigens in patients with type 1 diabetes

Cell mediated immune response in vitro to a number of antigens has been reported in patients with Type 1 diabetes. The aim of the present study was to develop an in vivo intradermal (delayed type hypersensitivity) skin test using antigens known to be recognized by lymphocytes of patients with Type 1 diabetes and to compare, where possible, the in vivo response to the in vitro T cell proliferation to the same antigens. The skin test was performed in the following group of patients: 55 with recent onset Type 1 diabetes; 16 patients with Type 1 diabetes of longer duration; 10 patients with autoimmune thyroid disease and 20 patients with Latent Autoimmune Diabetes in Adults (LADA). Type 1 diabetes specific antigens for the skin test included glutamic acid decarboxilase (GAD65), insulin and beta casein, whereas diabetes non specific antigens included tetanus toxoid, diphteria, proteus, tubercolin, streptococcus, and glycerol as control. A multitest device consisting of heads delivering intradermally 10 microl of solution containing the antigens was applied to the forearms; the specific antigens were injected in one forearm whereas the non specific antigens were injected in the other forearm. Reading of the reaction, which was considered positive in the presence of a nodule of 2 mm diameter was performed 48 h after the multitest application. The in vitro T cell response to diabetes specific antigens used in the multitest was studied using conventional proliferation assays in patients with recent onset Type 1 diabetes and in age matched normal subjects. Only recent onset Type 1 diabetes patients showed an in vivo positive response to GAD65, such response being detectable in 10 patients (18%). Two patients reacted also to beta casein and insulin, all other patient groups resulted negative but 2 patients with longer duration of Type 1 diabetes. There was no apparent link between the in vivo skin test and in vitro T cell proliferation to GAD65. We conclude that in vivo cell mediated immune reaction to GAD65, insulin and beta casein can be visualized in a minority of patients with recent onset Type 1 diabetes. Further studies are required to determine specificity and whether altering the dose can improve the sensitivity of the test.

Bovine beta-casein antibodies in breast- and bottle-fed infants: their relevance in Type 1 diabetes

BACKGROUND

Bovine beta-casein is a cow's milk protein that targets both humoral and cellular immune responses in patients with Type 1 diabetes and, to a lesser degree, also in normal subjects. In this study we aimed to determine whether the avoidance of cow's milk consumption early in life could prevent the development of antibody response to bovine beta-casein despite the mother being exposed on a daily basis to cow's milk consumption.

MATERIALS AND METHODS

We measured the antibody response to bovine beta-casein using an ELISA method in 28 healthy infants under 4 months of age, of whom 16 were exclusively breast-fed and 12 were bottle-fed with cow's milk. In addition, beta-casein antibodies were measured in 37 prepubertal children with Type 1 diabetes and in 31 healthy children who were exposed to cow's milk or dairy products to see whether differences in antibody titers exist in this young age group. Antibodies binding to beta-casein were also evaluated by immunoblotting analysis.

RESULTS

Elevated levels of beta-casein antibodies were found in bottle-fed infants compared to breast-fed infants (p<0.0001). Antibody levels to bovine beta-casein were also significantly higher in children with Type 1 diabetes compared to age-matched controls (p=0.03). By western blot analysis we confirmed specific binding to bovine beta-casein in bottle-fed infants, in children with Type 1 diabetes and in controls exposed to cow's milk, but not in infants who were exclusively breast-fed.

CONCLUSIONS

The results of this study indicate that breastfeeding within the first 4 months of life prevents the generation of antibody response to bovine beta-casein despite the mothers' consumption of cow's milk during the breastfeeding period. These findings may have relevance for disease prevention.

Neuroregulation of growth hormone during exercise in children

Physical exercise is an important physiological stimulus to growth hormone (GH) release in man. Many neurotransmitters are involved in GH regulation. We studied the effect of the cholinergic pathway on GH secretion induced by physical exercise. Particularly, we studied the effect of a cholinergic muscarinic agonist on GH-induced physical exercise, both in children and adults. Moreover, we investigated the refractoriness of GH secretion after a second physical exercise stimulus. Three different protocols were performed: 1) GH response to physical exercise in children and adults; 2) effect of pyridostigmine on exercise-induced GH secretion in children and adults; 3) GH response to two consecutive exercises in children and adults. Our data show that in children GH peak after physical exercise is higher than in adults. Pyridostigmine enhances GH release in children and in adults. Exercise stimulus was able to release GH in the second test only in children, while the refractory phase did not permit a new GH release in adults. The shift to a modality of neural control of GH secretion peculiar of adults is likely due to neuroregulatory mechanisms which may be partly dependent on long-term variation in hormonal milieu.

Characterization and properties of dominant-negative mutants of the ras-specific guanine nucleotide exchange factor CDC25(Mm)

Ras proteins are small GTPases playing a pivotal role in cell proliferation and differentiation. Their activation depends on the competing action of GTPase activating proteins and guanine nucleotide exchange factors (GEF). The properties of two dominant-negative mutants within the catalytic domains of the ras-specific GEF, CDC25(Mm), are described. In vitro, the mutant GEF(W1056E) and GEF(T1184E) proteins are catalytically inactive, are able to efficiently displace wild-type GEF from p21(ras), and strongly reduce affinity of the nucleotide-free ras x GEF complex for the incoming nucleotide, thus resulting in the formation of a stable ras.GEF binary complex. Consistent with their in vitro properties, the two mutant GEFs bring about a dramatic reduction in ras-dependent fos-luciferase activity in mouse fibroblasts. The stable ectopic expression of the GEF(W1056E) mutant in smooth muscle cells effectively reduced growth rate and DNA synthesis with no detectable morphological changes.

Somatostatin infusion withdrawal: studies in normal children and in children with growth hormone deficiency

Withdrawal of a somatostatin infusion (SSIW) is followed by a rebound rise of GH in both animals and normal adult men, a phenomenon likely mediated by endogenous GHRH function. In the present study, we have evaluated the GH response to SSIW in a group of 28 prepubertal children (18 boys and 10 girls; aged 3.7-11.1 yr). Six children had GH deficiency [GHD; GH responses to pyridostigmine (PD)+GHRH and to clonidine <20 and <7 microg/L, respectively], 4 children had GH neurosecretory dysfunction (GHND; GH responses to PD+GHRH and to clonidine > or =20 and >7 microg/L, respectively; mean integrated nighttime GH concentrations <3 microg/L), and 18 children were short normal children [normal controls (NC)]. All children received a constant infusion of SS at the dose of 3 microg/Kg x h for 90 min. SSIW elicited a clear-cut GH rise in NC children (13.7+/-1.0 microg/L), but not in GH-deficient children, regardless of the underlying etiology (GHD, 1.6+/-0.4 microg/L; GHND, 2.4+/-0.3 microg/L). The GH response to SSIW was similar between GHD and GHND children. There was no overlapping of the maximum SSIW-stimulated GH peaks between NC and GHD or GHND children. In conclusion, we have demonstrated that SSIW elicits a significant GH rise in NC children, but not in GH-deficient children, regardless of the underlying etiology (GHD or GHND). This resulted in complete discrimination of NC from GHD or GHND children. Were these present findings confirmed on a larger number of children, SSIW, because of its testing efficaciousness and safety, procedural simplicity, and economy holds promise of being a useful diagnostic tool for GH-dependent growth disorders.

T-cell mediated autoimmunity to the insulinoma-associated protein 2 islet tyrosine phosphatase in type 1 diabetes mellitus

The target molecules of the T-cell response in type 1 diabetes, despite their pathogenic importance, remain largely uncharacterized, especially in humans. Interestingly, molecules such as insulin and glutamic acid decarboxylase (GAD) have been shown to be a target not only of autoantibodies, but also of autoreactive T-lymphocytes both in man and in the non-obese diabetic (NOD) mouse. In the present study we aimed to determine the existence of a specific T-cell response towards the insulinoma-associated protein 2 (IA-2) islet tyrosine phosphatase, a recently identified autoantigen which is the target of autoantibodies strongly associated with diabetes development. Human recombinant IA-2 produced in Escherichia coli, was tested for its reactivity with peripheral blood lymphocytes obtained from 16 newly diagnosed type 1 diabetic patients and from 25 normal controls, 15 of whom were HLA-DR-matched. A T-cell proliferation assay was performed in triplicate employing freshly isolated cells in the absence or in the presence of the antigen to be tested (at two different concentrations: 2 microg/ml and 10 microg/ml). A specific T-cell proliferation (defined as a stimulation index (S.I.) >/=3) was observed against IA-2 used at a concentration of 10 microg/ml (but not of 2 microg/ml) in 8/16 diabetic patients, in 1/15 HLA-DR-matched control subjects (P<0.01 by Fisher exact test) and in 0/10 of the remaining normal individuals. A statistically significant difference (P<0.003 by Mann-Whitney U test) was also observed in S.I. values between patients (3.1+/-1.4) and HLA-DR-matched controls (1.7+/-0.54) employing IA-2 at a concentration of 10 microg/ml. However, when IA-2 was used at a concentration of 2 microg/ml, the difference in S. I. between patients (1.65+/-0.8) and controls (1.0+/-0.3) did not reach statistical significance. In conclusion, these data show the presence of a specific, dose-dependent T-lymphocyte response against the IA-2 islet tyrosine phosphatase at the onset of type 1 diabetes. Consequently, this molecule appears to be a target not only at the B-lymphocyte but also at the T-lymphocyte level, reinforcing the potential pathogenic role of this autoantigen in the islet destructive process.

Thioredoxin, a redox enzyme released in infection and inflammation, is a unique chemoattractant for neutrophils, monocytes, and T cells

Thioredoxin (Trx) is a ubiquitous intracellular protein disulfide oxidoreductase with a CXXC active site that can be released by various cell types upon activation. We show here that Trx is chemotactic for monocytes, polymorphonuclear leukocytes, and T lymphocytes, both in vitro in the standard micro Boyden chamber migration assay and in vivo in the mouse air pouch model. The potency of the chemotactic action of Trx for all leukocyte populations is in the nanomolar range, comparable with that of known chemokines. However, Trx does not increase intracellular Ca2+ and its activity is not inhibited by pertussis toxin. Thus, the chemotactic action of Trx differs from that of known chemokines in that it is G protein independent. Mutation of the active site cysteines resulted in loss of chemotactic activity, suggesting that the latter is mediated by the enzyme activity of Trx. Trx also accounted for part of the chemotactic activity released by human T lymphotropic virus (HTLV)-1-infected cells, which was inhibited by incubation with anti-Trx antibody. Since Trx production is induced by oxidants, it represents a link between oxidative stress and inflammation that is of particular interest because circulating Trx levels are elevated in inflammatory diseases and HIV infection.

Prognostic implications of hyperglycaemia in paediatric head injury

Fifty children with head injury were evaluated in an attempt to establish a correlation between post-traumatic hyperglycaemia and long-term outcome. In all the patients, the blood glucose level was measured on admission and on the days following the trauma (threshold of normal value set at 150 mg/dl). Hyperglycaemia was seen more frequently in children with severe head injury than in those with mild and moderate head injury. It was present in 87.5% of the patients with a Glasgow Coma Score (GCS) < or =8 (the average blood glucose level on admission was 237.8+/-92 mg/dl), in 60% of the patients with a GCS of 9-12 (178+/-78.7 mg/dl) and only in 25% of those with a GCS of 13-15 (131.5+/-39 mg/dl). A close correlation was also seen between the outcome and the blood glucose level. In fact, the blood glucose on admission was higher in the patients with a poor outcome, i.e. in those having a Glasgow Outcome Score (GOS) of 2 or 3 and in those who died (GOS 1), than in the patients with a good outcome (GOS of 4 or 5). Finally, hyperglycaemia persisted beyond the first 24 h after trauma in all the children who died or who survived with a poor outcome. Hyperglycaemia, and especially its persistence over time, appears to be an important negative prognostic factor in children with head injury.

Interaction between interleukin-1 and ciliary neurotrophic factor in the regulation of neuroblastoma cell functions

Human neuroblastoma cells SK-N-SH express significant numbers of IL-1R type I on their surface, as detected by saturation binding and RT-PCR, and are responsive to IL-1beta activation by producing inflammatory cytokines IL-6 and IL-8. IL-1beta can also have an indirect effect on nervous cell functions, since it is able to modulate the stimulus-induced increase of intracellular Ca++ levels, one of the first steps of the cell activation mechanism. In fact, on SK-N-SH neuroblastoma cells, IL-1beta can inhibit the Ca++ increase induced by stimulation of acetylcholine receptors with carbachol. In parallel to IL-1beta, the neurotrophic factor CNTF also shows an inhibitory effect on carbachol-stimulated Ca++ increase in CNTFRalpha-expressing SK-N-SH cells. However, when simultaneously present, the two cytokines cross-inhibit, thus allowing full cell activation in response to the cholinoceptor agonist. The inhibitory effect of CNTF on IL-1beta activities on nervous cells was confirmed in the IL-6 production assay. In fact, while CNTF could not induce IL-6 production, it could strongly inhibit cytokine production in response to IL-1beta in SK-N-SH cells. The down-modulation of IL-1 effects by CNTF could be one of the mechanisms controlling the extent of the inflammatory reaction at the nervous system level.

Inhibitory activity of IL-1 receptor antagonist depends on the balance between binding capacity for IL-1 receptor type 1 and IL-1 receptor type II

A series of mutants of human IL-1 receptor antagonist (IL-1ra) has been designed by comparison of IL-1ra and IL-1beta structures in order to increase receptor antagonist capacity. Upon in vitro and in vivo assay of IL-1 antagonism, the IL-1ra mutants DoB 0039 (N91--&gt;R), DoB 0040 (T109--&gt;A) and DoB 0041 (N91/T109--&gt;R/A) could inhibit IL-1beta effects more efficiently than wild-type IL-1ra, with DoB 0041 being the most active. Analysis of the receptor-binding capacity of the IL-1ra mutants showed that all three mutants could inhibit binding of IL-1alpha or IL-1beta to IL-1RI-bearing cells more efficiently than wild-type IL-1ra. Conversely, binding of IL-1beta to IL-1RII-bearing cells could be inhibited by DoB 0041 much less efficiently than by wild-type IL-1ra. It is known that the two types of IL-1 receptors (IL-1RI and IL-1RII) play different roles in the regulation of IL-1 activity, with IL-1RI being solely responsible for cell triggering upon IL-1 binding, whereas IL-1RII acts as a scavenger of IL-1 and can thus be considered as a natural IL-1 inhibitor. Thus, the enhanced inhibitory capacity of DoB 0041 as compared with wild-type IL-1ra is explained in terms of better binding to the activating receptor IL-1RI and poorer interaction with the inhibitory receptor IL-1RII.

Inhibitory activity of IL-1 receptor antagonist depends on the balance between binding capacity for IL-1 receptor type 1 and IL-1 receptor type II

A series of mutants of human IL-1 receptor antagonist (IL-1ra) has been designed by comparison of IL-1ra and IL-1beta structures in order to increase receptor antagonist capacity. Upon in vitro and in vivo assay of IL-1 antagonism, the IL-1ra mutants DoB 0039 (N91-->R), DoB 0040 (T109-->A) and DoB 0041 (N91/T109-->R/A) could inhibit IL-1beta effects more efficiently than wild-type IL-1ra, with DoB 0041 being the most active. Analysis of the receptor-binding capacity of the IL-1ra mutants showed that all three mutants could inhibit binding of IL-1alpha or IL-1beta to IL-1RI-bearing cells more efficiently than wild-type IL-1ra. Conversely, binding of IL-1beta to IL-1RII-bearing cells could be inhibited by DoB 0041 much less efficiently than by wild-type IL-1ra. It is known that the two types of IL-1 receptors (IL-1RI and IL-1RII) play different roles in the regulation of IL-1 activity, with IL-1RI being solely responsible for cell triggering upon IL-1 binding, whereas IL-1RII acts as a scavenger of IL-1 and can thus be considered as a natural IL-1 inhibitor. Thus, the enhanced inhibitory capacity of DoB 0041 as compared with wild-type IL-1ra is explained in terms of better binding to the activating receptor IL-1RI and poorer interaction with the inhibitory receptor IL-1RII.

Purification of human recombinant interleukin 1 receptor antagonist proteins upon Bacillus subtilis sporulation

Human interleukin 1 receptor antagonist (IL-1ra) and IL-1ra mutants were constitutively expressed in recombinant Bacillus subtilis in endocellular and active form. In order to optimize the purification of the recombinant proteins, a new method has been developed. After bacterial growth in fermenter, release of recombinant protein was achieved by starvation-induced sporulation. The sporulation supernatant was recovered by centrifugation, filtered, and subjected sequentially to cation- and anion-exchange chromatography. Alternatively, the fermenter's contents were directly subjected to expanded bed adsorption on a Streamline cation-exchange column, thus avoiding the centrifugation and filtration steps. Up to 88 mg of biological active purified recombinant protein per liter of culture was obtained, with a 72-79% recovery and 98% purity, depending on the molecule. By using the method described here, it is possible to achieve a spontaneous release of recombinant proteins expressed endocellularly at high levels in B. subtilis without need of a cell breakage step. Thus, this method could allow purification of the endocellular recombinant protein as if it were secreted. Furthermore, when using the expanded bed adsorption, highly purified protein was obtained in only two steps after sporulation. Among the advantages of the method, one of the most relevant is the possibility of keeping the system closed up to completion of the first purification step.

Incidence of insulin-dependent diabetes mellitus among Sardinian-heritage children born in Lazio region, Italy

BACKGROUND

The relative importance of genetic and environmental factors in causing insulin-dependent diabetes mellitus (IDDM) is unknown. We studied this question by assessing the incidence of the disease in children, born in a region with a low incidence of IDDM (Lazio), but whose parents came from a region with high incidence (Sardinia).

METHODS

We identified all IDDM cases that occurred between 1989 and 1994. We used as the denominator the number of children aged 0-14 born in Lazio of Sardinian parents to calculate incidence. We compared this rate with the incidences of IDDM in the populations of Lazio and Sardinia.

FINDINGS

The age-adjusted incidence of IDDM in Sardinian-heritage children born and living in Lazio was 33.8 per 100,000 per year (95% CI 7.0-99.0) for those with two Sardinian parents, and 15.9 (8.7-26.6) for those with only one parent from Sardinia. The former incidence was not different from that recorded in Sardinia (34.4, 31.3-37.9), but was fourtold that of Lazio-heritage children (7.9, 7.1-8.8).

INTERPRETATION

Our results show that two different ethnic groups living in the same region have a fourfold difference in incidence of IDDM. Children of Sardinian-heritage born in Lazio have the same incidence as the population of origin, which is genetically prone to the disease. Moreover, children with one Sardinian parent had a rate half that of Sardinians and double that of the indigenous population. We conclude that in a given population genetic susceptibility determines the frequency of IDDM in response to the environmental challenge.

IL-1 beta primes IL-8-activated human neutrophils for elastase release, phospholipase D activity, and calcium flux

Interleukin-8 (IL-8), the prototype of the alpha (e.i., C-X-C branch) chemokine family, induced elastase release in a concentration-dependent manner (50-1000 ng/mL) in cytochalasin B-treated human polymorphonuclear leukocytes (PMNs). This response was potentiated about twofold if PMNs were preexposed to interleukin-1 beta (IL-1 beta) at concentrations that were by themselves inactive. The effect of IL-1 beta was clearly observed after 5 min and was maximal after a 30-min preincubation of the cells. The effect was present over the whole active concentration range of IL-8 and was completely blocked by the presence of IL-1 receptor antagonist. Priming of elastase release by IL-1 beta was not associated with a change in receptor number or affinity for IL-8. On the contrary, it was correlated with priming of phospholipase D activity and calcium flux activated by IL-8. Preincubation of the cells with ethanol and/or La3+ inhibited IL-8-induced degranulations, suggesting that activation of phospholipase D and increase of [Ca2+]i were important for this response. In contrast, ethanol and La3+ did not decrease the priming effect of IL-1 beta. IL-8 and IL-1 beta have been shown to be released by the same cell types and may be concomitantly present at sites of inflammation, giving rise to an amplification of the inflammatory response.