Altered insulin secretion dynamics relate to oxidative stress and inflammasome activation in children with obesity and insulin resistance.

BACKGROUND: Insulin resistance (IR) is considered the main driver of obesity related metabolic complications, and is related to oxidative stress and inflammation, which in turn promote each other. There is currently no specific definition of IR in children, rather, that for adult population is used by pediatric endocrinologists instead. Altered insulin secretion dynamics are associated with worse metabolic profiles and type 2 diabetes mellitus development, thus we aimed to test whether insulin response relates to oxidative stress and inflammation in children. METHODS: We conducted a case-control study, including 132 children classified as follows: 33 children without obesity (Lean); 42 with obesity but no IR according to the American Diabetes Association criteria for adults (OBIR-); 25 with obesity and IR and an early insulin response to an oral glucose tolerance test (OGTT) (EP-OBIR +); 32 with obesity, IR, and a late insulin peak (LP-OBIR +); and studied variables associated with lipid and carbohydrate metabolism, oxidative stress, inflammation and inflammasome activation. RESULTS: The measured parameters of children with obesity, IR, and an early insulin response were similar to those of children with obesity but without IR. It was late responders who presented an impaired antioxidant system and elevated oxidative damage in erythrocytes and plasma, and inflammasome activation at their white blood cells, despite lower classical inflammation markers. Increased uric acid levels seems to be one of the underlying mechanisms for inflammasome activation. CONCLUSIONS: It is insulin response to an OGTT that identifies children with obesity suffering oxidative stress and inflammasome activation more specifically. Uric acid could be mediating this pathological inflammatory response by activating NLRP3 in peripheral blood mononuclear cells.

Assessment of the perception of vertical subjectivity in children born preterm.

Children born preterm have increased rates of paediatric mortality and morbidity. Prematurity has been associated with impaired visual perception and visuo-motor integration. The alteration of the perception of verticality translates into alterations of the vestibular system at central and/or peripheral level, which may manifest itself in symptoms such as imbalance, dizziness or even vertigo. The aim of this study was to compare subjective visual vertical (SVV) test scores in children born preterm with those of children born at term at ages between 7 and 10. One hundred ten children with no neurodevelopmental disorder of 7 to 10 years of age were studied using a mobile application on a smartphone attached to a wall by means of a rotating plate. The SVV test was compared between two groups: a group of 55 preterm children (53 very preterm children born under 32 weeks of gestational age and 2 preterm with very low birth weight) and another group of 55 children born at term (after 37 weeks of gestational age). The SVV results were analysed for comparison with respect to prematurity, sex and age. We found no significant differences in the SVV study in the comparison between preterm and term children. In addition, no significant differences were observed regarding sex or age between 7 and 10 years.  Conclusion: We found no alterations in the perception of vertical subjectivity in children between 7 and 10 years of age, with antecedents of very preterm birth and/or very low birth weight. What is Known: • The different studies published so far suggest the existence of balance disorders in premature children, although in most of these studies the children are examined at an age when the vestibular system is not mature and with non-specific tests for the study of the vestibular system. What is New: • We compared the results of the subjective visual vertical (SVV) test in a group of 55 preterm children (53 very preterm children born under 32 weeks of gestational age and 2 preterm with very low weight at birth) and in a group of 55 children born at term (after 37 weeks of gestational age), at the ages of 7 to 10 years and observed no differences. • We conclude that, if there had been any vestibular alterations due to very premature birth, these must have been compensated by the age of 7.

Test-retest of the Subjective Visual Vertical Test performed using a mobile application with the smartphone anchored to a turntable.

PURPOSE: The alterations of the Subjective visual vertical test are related to vestibular pathology. Our previously validated method to distinguish between healthy and pathological individuals measures the deviation from the Subjective visual vertical using a mobile application installed on a smartphone fixed to a turntable anchored to the wall. The aim of this study was evaluating the intra-observer reliability of our method in individuals with or without vestibular pathology. METHODS: Participants were recruited consecutively. In each individual two measurements with an interval of 2 h were made. Both tests were performed by the same examiner. A total of 91 patients were included in this study, of which 25 were healthy and 66 diseased. Intra-observer reliability was evaluated using the intraclass correlation coefficient (ICC). To assess the clinical accuracy of the measurement, we calculated the standard error of the measurement (SEM) and the minimum detectable change (MDC) with a 95% confidence interval. RESULTS: Intra-observer reliability was excellent with an ICC 0.95 (0.92-0.97) in the whole sample, in healthy patients 0.91 (0.80-0.96) and in pathological patients 0.92 (0.87-0.95). The SEM was calculated to be 0.59 for the whole sample (0.26 in the "healthy" group, and 0.67 in the pathological group). Likewise, the sample's MDC was 1.16, being 0.52 and 1.36 for the healthy and the pathological group, respectively. CONCLUSIONS: Considering the results, our method presents an excellent intraobserver reliability. Furthermore, changes in deviation greater than 0.52 in healthy individuals and 1.36 in pathological individuals can be considered a real change in deviation.

Growth hormone treatment does not to lead to insulin resistance nor excessive rise in IGF-1 levels, while improving height in patients small for gestational age A long-term observational study.

OBJECTIVE: In children born small for gestational age (SGA), the relationship between growth hormone (GH) treatment and insulin resistance (IR) has only been investigated for a short period, necessitating a longer observation period. This study aimed to evaluate the long-term (10 years) effect of GH to SGA-children on IR and safety during treatment. DESIGN: This was a multicenter observational study. PATIENTS: SGA-children who received GH treatment in Spain (stratified by Tanner-stage and age at GH onset [two groups: ≤6 years old or >6 years old]). MEASUREMENTS: The analysed variables (yearly measures) included auxologic, metabolic (insulin-like growth factor-1 (IGF-1), height velocity [HV], weight and homeostatic model assessment-IR [HOMA-IR]) and safety data. Data were collected prospectively (since the study approval: 2007) and retrospectively (since the initiation of GH treatment: 2005-2007). RESULTS: A total of 389 SGA children (369 Tanner-I) were recruited from 27 centres. The mean age (standard deviation) of the children at GH treatment onset was 7.2 (2.8) years old. IGF-1 (standard deviation score [SDS]) and HOMA-IR values tended to increase until the sixth year of GH-treatment, with significant differences being observed only during the first year, while these remained stable in the later years (within normal ranges). Height (SDS) increased significantly (basal: -3.0; tenth year: -1.13), and the maximum HV (SDS) occurred during the first year (2.75 ± 2.39). CONCLUSIONS: HOMA-IR values increased significantly in SGA-children during the first year of GH-treatment, remained stable and were within normal ranges in all cases. Our 10-year data suggests that long-term GH treatment does not promote IR and is well-tolerated, safe and effective.

Toxicity Induced by Cytokines, Glucose, and Lipids Increase Apoptosis and Hamper Insulin Secretion in the 1.1E7 Beta Cell-Line.

Basic research on types 1 and 2 diabetes mellitus require early stage studies using beta cells or cell lines, ideally of human origin and with preserved insulin secretion in response to glucose. The 1.1E7 cells are a hybrid cell line resulting from the electrofusion of dispersed human islets and PANC-1 cells, capable of secreting insulin in response to glucose, but their survival and function under toxic conditions remains untested. This characterization is the purpose of the present study. We treated these cells with a cytokine mix, high glucose, palmitate, and the latter two combined. Under these conditions, we measured cell viability and apoptosis (MTT, Caspase Glo and TUNEL assays, as well as caspase-8 and -9 levels by Western blotting), endoplasmic reticulum stress markers (EIF2AK3, HSPA4, EIF2a, and HSPA5) by real-time PCR, and insulin secretion with a glucose challenge. All of these stimuli (i) induce apoptosis and ER stress markers expression, (ii) reduce mRNA amounts of 2-5 components of genes involved in the insulin secretory pathway, and (iii) abrogate the insulin release capability of 1.1E7 cells in response to glucose. The most pronounced effects were observed with cytokines and with palmitate and high glucose combined. This characterization may well serve as the starting point for those choosing this cell line for future basic research on certain aspects of diabetes.

Normal Cerebellar Growth by Using Three-dimensional US in the Preterm Infant from Birth to Term-corrected Age.

Purpose To establish cross-sectional and longitudinal reference values for cerebellar size in preterm infants with normal neuroimaging findings and normal 2-year neurodevelopmental outcome by using cranial ultrasonography (US). Materials and Methods This prospective study consecutively enrolled preterm infants admitted to a neonatal intensive care unit from June 2011 to June 2014 with a birth weight of less than or equal to 1500 g and/or gestational age (GA) of less than or equal to 32 weeks. They underwent weekly cranial US from birth to term-equivalent age and magnetic resonance (MR) imaging at term-equivalent age. The infants underwent neurodevelopmental assessments at age 2 years with Bayley Scales of Infant and Toddler Development, 3rd edition (BSID-III). Patients with adverse outcomes (death or abnormal neuroimaging findings and/or BSID-III score of <85) were excluded. The following measurements were performed: vermis height, craniocaudal diameter, superior width, inferior width, vermis area, and transcerebellar diameter. Statistical analyses were conducted by using multilevel analyses. Results A total of 137 infants with a mean GA at birth of 29.4 weeks (range, 25-32 weeks) were included. Transcerebellar diameter increased by 1.04 mm per week on average; vermis height and craniocaudal diameter increased by 0.55 mm and 0.59 mm, respectively. Superior vermian width increased by an average of 0.45 mm, whereas inferior vermian width increased by an average of 0.51 mm per week. Vermis area was found to increase by 0.22 cm2 per week on average. The sex effect was significant (female lower than male) for vermis height (P < .05), craniocaudal diameter (P < .05), inferior vermian width (P <. 05), and vermis area (P <. 05). Conclusion Cross-sectional and longitudinal reference values were established for cerebellar growth in preterm infants, which may be included in routine cranial US.

Ghrelin mitigates ß-cell mass loss during insulitis in an animal model of autoimmune diabetes mellitus, the BioBreeding/Worcester rat.

BACKGROUND: Ghrelin is a peptide hormone with pleiotropic effects. It stimulates cell proliferation and inhibits apoptosis-mediated cell death. It prevents diabetes mellitus in several models of chemical, surgical and biological toxic insults to pancreas in both in vivo and in vitro models and promotes glucose-stimulated insulin secretion under cytotoxic conditions. It has not yet been tested in vivo in an autoimmune model of diabetes with a persistent insult to the ß-cell. Given the immunomodulating effects of ghrelin and its trophic effects on ß-cells, we hypothesized that ghrelin treatment during the early stages of insulitis would delay diabetes onset. METHODS: BioBreeding/Worcester male rats received ghrelin (10 ng/kg/day) before insulitis development. Glucose metabolism was characterized by glucose and insulin tolerance tests. ß-cell mass, islet area, islet number, ß-cell clusters, proliferation and apoptosis and degree of insulitis were analysed by histomorphometry. A Kaplan-Meier survival curve was plotted and analysed applying the log-rank (Mantel-Cox) test. RESULTS: Ghrelin treatment significantly reduced the probability of developing diabetes in our model (p < 0.0001). It decreased islet infiltration and partially prevented ß-cell mass loss, enabling the maintenance of ß-cell neogenesis and proliferation rates. Furthermore, ghrelin treatment did not induce any metabolic perturbations. CONCLUSIONS: These findings support the hypothesis that ghrelin delays the development of autoimmune diabetes by attenuating insulitis and supporting ß-cell mass. GENERAL SIGNIFICANCE: Ghrelin promotes ß-cell viability and function through diverse mechanisms that may have significant implications for diabetes prevention, therapy and also transplant success of both islets and complete pancreas. Copyright © 2016 John Wiley & Sons, Ltd.

Ultrasound lineal measurements predict ventricular volume in posthaemorrhagic ventricular dilatation in preterm infants.

AIM: Posthaemorrhagic ventricular dilatation (PHVD) is monitored by conventional two-dimensional ultrasound (2DUS). The aims of this study were to determine the volume of the lateral ventricles using three-dimensional ultrasound (3DUS) in preterm infants with PHVD and to evaluate the relationship between volume and linear measurements. METHODS: Serial 2DUSs and 3DUSs were performed on preterm infants with PHVD admitted to the neonatal intensive care unit at Puerta del Mar Hospital, Cádiz, Spain, from January 2013 to December 2014. The ventricular index, anterior horn width and thalamo-occipital distance were used as ventricular lineal measurements. Ventricular volume was calculated offline. RESULTS: Serial ultrasounds from seven preterm infants were measured. Each linear measurement was significantly associated with volume, and an equation was obtained through a significant multilevel mixed-effects lineal regression model: ventricular volume (cm3 ) = -11.02 + 0.668*VI + 0.817*AHW + 0.256*TOD. Intra-observer and interobserver agreement was excellent with an intraclass correlation coefficient of 0.99. CONCLUSION: Lateral ventricular volumes of preterm infants with PHVD could be reliably determined using 3DUS. Ventricular volume could be accurately estimated using three lineal measurements. More studies are needed to address the importance of volume determination in PHVD.

Supraventricular tachycardia after withdrawal of prolonged dexmedetomidine infusion in a paediatric patient without heart disease.

WHAT IS KNOWN AND OBJECTIVE: Dexmedetomidine (DEX) has been reported to be safe in paediatric patients. CASE DESCRIPTION: We present the case of a girl without heart disease admitted at our PICU due to an influenza A acute respiratory distress syndrome, who suffered a paroxysmal supraventricular tachycardia (PSVT) twelve hours after DEX progressive withdrawal was completed. WHAT IS NEW AND CONCLUSION: This is the first report of PSVT as an adverse reaction to DEX in a paediatric patient without heart disease.

Safety and Effectiveness of a Biosimilar Recombinant Human Growth Hormone in Children Requiring Growth Hormone Treatment: Analysis of Final Data from PATRO Children, an International, Post-Marketing Surveillance Study.

Purpose: Omnitrope® (somatropin) was approved as a biosimilar recombinant human growth hormone (rhGH) in 2006. Here, we report final data from the PAtients TReated with Omnitrope® (PATRO) Children study, a post-marketing surveillance study designed to monitor the long-term safety and effectiveness of this treatment in pediatric patients. Methods: The study population included all pediatric patients treated with Omnitrope® (biosimilar rhGH), administered via daily injection, in routine clinical practice. The primary objective was to assess long-term safety, with effectiveness assessed as a secondary objective. Results: In total, 7359 patients were enrolled and treated in the PATRO Children study; 86.0% were treatment-naïve at baseline. Growth hormone deficiency was the most frequent indication (57.9%), followed by patients born small for gestational age (SGA; 26.6%). The mean (SD) duration of exposure to biosimilar rhGH was 3.66 years (2.39). A total of 16,628 adverse events (AEs) were reported in 3981 (54.1%) patients, most of which were mild/moderate. AEs suspected to be treatment related occurred in 8.3% of patients, most frequently headache (1.6%), injection-site pain (1.1%), or injection-site hematoma (1.1%). The incidence rate (IR) of type 2 diabetes mellitus was 0.11 per 1000 person-years (PY) across all patients, and 0.13 per 1000 PY in patients born SGA. The IR of newly diagnosed primary malignancies was 0.22 per 1000 PY across all patients. In the 6589 patients included in the effectiveness population, a sustained catch-up growth was observed across all indications. After 5 years of treatment, height SDS increased from baseline by a median (range) of +1.79 (-3.7 to 6.2) in treatment-naïve patients and +0.73 (-1.4 to 3.7) in pretreated patients. Conclusion: This final analysis of the PATRO Children study indicates that biosimilar rhGH is well tolerated and effective in real-world clinical practice. These data are consistent with the well-characterized safety profile of rhGH treatment in pediatric patients.

Structural and functional analysis of APOA5 mutations identified in patients with severe hypertriglyceridemia.

During the diagnosis of three unrelated patients with severe hypertriglyceridemia, three APOA5 mutations [p.(Ser232_Leu235)del, p.Leu253Pro, and p.Asp332ValfsX4] were found without evidence of concomitant LPL, APOC2, or GPIHBP1 mutations. The molecular mechanisms by which APOA5 mutations result in severe hypertriglyceridemia remain poorly understood, and the functional impairment/s induced by these specific mutations was not obvious. Therefore, we performed a thorough structural and functional analysis that included follow-up of patients and their closest relatives, measurement of apoA-V serum concentrations, and sequencing of the APOA5 gene in 200 nonhyperlipidemic controls. Further, we cloned, overexpressed, and purified both wild-type and mutant apoA-V variants and characterized their capacity to activate LPL. The interactions of recombinant wild-type and mutated apoA-V variants with liposomes of different composition, heparin, LRP1, sortilin, and SorLA/LR11 were also analyzed. Finally, to explore the possible structural consequences of these mutations, we developed a three-dimensional model of full-length, lipid-free human apoA-V. A complex, wide array of impairments was found in each of the three mutants, suggesting that the specific residues affected are critical structural determinants for apoA-V function in lipoprotein metabolism and, therefore, that these APOA5 mutations are a direct cause of hypertriglyceridemia.

Hepatocyte growth factor as an indicator of neonatal maturity.

Hepatocyte growth factor (HGF) is a potent mitogen and morphogen expressed in fetal organs. It requires activation by specific serine proteases. The role of activated HGF during fetal development has not been evaluated. We hypothesized that the serum levels of activated HGF would be increased in preterm neonates. Cord blood total HGF and activated HGF levels were measured in 19 preterm (gestational age, 28.04±2.39 weeks) and 24 term (gestational age, 39.37±0.95 weeks) newborns. Anthropometric parameters and metabolic indices were evaluated. Activated HGF was higher in preterm than in term neonates (0.81±0.05 vs. 0.61±0.06 ng/mL, p<0.05), whereas total HGF levels did not differ significantly between groups. In addition, total and activated HGF further increased by ∼40% in preterm neonates 12 h after birth. Finally, activated HGF correlated inversely with gestational age (r=-0.369; p=0.015) and birth weight (r=-0.440; p=0.003). Our study demonstrates that regulation of HGF activity and circulating HGF levels differ between term and preterm neonates along fetal development.

Increased Aß production prompts the onset of glucose intolerance and insulin resistance.

Type 2 diabetes (T2D) mellitus and Alzheimer's disease (AD) are two prevalent diseases with comparable pathophysiological features and genetic predisposition. Patients with AD are more susceptible to develop T2D. However, the molecular mechanism linking AD and T2D remains elusive. In this study, we have generated a new mouse model to test the hypothesis that AD would prompt the onset of T2D in mice. To test our hypothesis, we crossed Alzheimer APPswe/PS1dE9 (APP/PS1) transgenic mice with mice partially deficient in leptin signaling (db/+). Body weight, plasma glucose, and insulin levels were monitored. Phenotypic characterization of glucose metabolism was performed using glucose and insulin tolerance tests. ß-Cell mass, islet volume, and islet number were analyzed by histomorphometry. APP/PS1 coexpression in mice with intact leptin receptor signaling did not show any metabolic perturbations in glucose metabolism or insulin sensitivity. In contrast, APP/PS1 coexpression in db/+ mice resulted in nonfasting hyperglycemia, hyperinsulinemia, and hypercholesterolemia without changes in body weight. Conversely, fasting blood glucose and cholesterol levels remained unchanged. Coinciding with altered glucose metabolism, APP/PS1 coexpression in db/+ mice resulted in glucose intolerance, insulin resistance, and impaired insulin signaling. In addition, histomorphometric analysis of pancreata revealed augmented ß-cell mass. Taken together, these findings provide experimental evidence to support the notion that aberrant Aß production might be a mechanistic link underlying the pathology of insulin resistance and T2D in AD.

Novel mutation in the epithelial sodium channel causing type I pseudohypoaldosteronism in a patient misdiagnosed with cystic fibrosis.

UNLABELLED: Cystic fibrosis (CF) is an inherited disorder with a devastating prognosis. Determination of chloride concentration in sweat has been the gold standard test for diagnosing CF for over 50 years and still remains the primary screening test. However, now that the genetic cause is known and can be studied, genetic confirmation is mandatory in every suspected patient. We present a patient who had been clinically diagnosed and whose genetic testing could not confirm CF, leading us to search for other options that may also give a positive sweat test. The patient turned out to suffer type 1 pseudohypoaldosteronism, a condition that may cause severe dehydration, hyponatremia and hyperkalemia episodes if not diagnosed and treated early with sodium supplementation. We found a genetic variation in the epithelial sodium channel gene which has not been reported previously, and we discuss the possibility of it being the cause of our patient's phenotype. CONCLUSION: this patient clearly illustrates the usefulness of genetic confirmation for CF for the diagnosis and genetic counselling, even when it is clinically oriented, and describes a novel mutation of the amiloride-sensitive epithelial sodium channel possibly causing type 1 pseudohypoaldosteronism.

Efficacy of the subjective visual vertical test performed using a mobile application to detect vestibular pathology.

BACKGROUND: The subjective visual vertical (SVV) test is a sensitive test of vestibular dysfunction that allows the evaluation of otolithic organs; however, with the current method, there are technical and logistical limitations that make the application of this test difficult in the conventional clinic. OBJECTIVE: The objective of this study is to assess the effectiveness of detecting vestibular pathology using the SVV via a new screening method. METHODS: A consecutive sample of 62 patients with suspected vestibular pathology was included in the study. The patients were clinically diagnosed according to the Barany Society criteria. An exploratory system was designed using a mobile application in Android that detects accelerometer oscillations and involves placing the smartphone on a rotating disk anchored to the wall. All patients underwent a SVV examination using the bucket method and the study test. A cut-off point of the ROC curve was calculated for each test, and its sensitivity, specificity, diagnostic accuracy and probability ratios for detecting vestibular pathology were analysed. The SVV results were compared using the bucket test and the study test. RESULTS: We observed significant differences in sensitivity between the two tests: 86.95% for the study test versus 67.4% for the bucket test (p < 0.01). In the ROC curve, an area under the curve of 0.90 was observed for the study test, with a cut-off of 2.43 for a sensitivity of 86.95% and a specificity of 93.75%. CONCLUSIONS: SVV testing using a smartphone placed on a rotating disk anchored to the wall offers greater diagnostic accuracy than SVV using the bucket test. Both methods are inexpensive, harmless and easily accepted by patients.

Adherence to Mediterranean Diet Is Associated With Better Glycemic Control in Children With Type 1 Diabetes: A Cross-Sectional Study.

Type 1 diabetes (T1D) is a chronic condition, with increased morbidity and mortality, due to a higher rate of cardiovascular disease among other factors. Cardiovascular risk increases with the worse glycemic profile. Nutrition has a deep impact on diabetes control. Adherence to the Mediterranean diet (MD) has been shown to decrease cardiovascular risk in children and adults with obesity and adults with type 2 diabetes, but its impact on T1D children has been scarcely analyzed. We hypothesized that the degree of adherence to MD could relate to the increased time in range in children with T1D. Patients and Methods: Cross-sectional analysis involving two university hospitals. We measured the adherence to MD with the Mediterranean Diet Quality Index for children and teenagers (KIDMED) questionnaire, which is a validated tool for this purpose. A score of <5 indicates poor adherence to MD, while a good adherence is indicated by a score of >7. Demographic and clinical data were registered on the same day that the questionnaire was taken, with informed consent. Additionally, the patients' ambulatory glucose profiles (AGPs), were registered from the participants' glucose monitors (continuous or flash devices), and daily insulin needs were recorded from patients' insulin pumps (n=28). Other cardiovascular risk factors such as lipid profile, vitamin D levels, and other biochemical parameters were registered from a blood test, performed 2 weeks before recruitment, as part of the patients' annual screening. Results: Ninety-seven patients (44 girls), with an average age of 11.4 years (± 3.01), were included. Seventy-one of them were on multiple daily injection regimens, and all had either continuous or flash glucose monitoring. Fifty-three had HbA1c levels of <7.5%, while only 21 had a time in range (TIR) of >70%. Contingency analysis showed that the odds of having HbA1c <7.5% increase in children with KIDMED score of >7 (O.R. 2.38; ICR 1.05-5.41; p = 0.036). Moreover, the KIDMED score and the HbA1c levels were negatively correlated (R: -0.245; p-value: 0.001), while the KIDMED score and TIR showed a positive correlation (R: 0.200; p-value: 0.009). Conclusions: Our data suggest that adherence to MD may contribute to better glycemic control in children. This should be taken into account at the time of nutritional education on T1D patients and their families.

Catalase post-translational modifications as key targets in the control of erythrocyte redox homeostasis in children with obesity and insulin resistance.

Insulin resistance (IR) is the most common metabolic disturbance in children with obesity. Children with obesity and insulin resistance (ObIR+) display a detriment in erythroid antioxidant defenses, caused by an impaired catalase activity and the increase in oxidative and pro-inflammatory markers. Therefore, erythrocytes from ObRI+ are more vulnerable to any oxidative stress elicitor. Since catalase is one of the erythrocytes' first antioxidant defenses, we intended to delve into the mechanisms underlying catalase's impaired activity. Given the lack of cellular organelles in erythrocytes, which prevents protein synthesis, we aimed study catalase post-translational modifications (PTMs) as targets of pro-inflammatory and pro-oxidant status of these cells in children with obesity and IR. Catalase levels of O-glycosylation, tyrosine nitration and S-glutathionylation were analyzed by Western blotting (WB) using immunoprecipitated catalase (IP-CAT) from erythrocyte lysates. Furthermore, Catalase was also identified by LC-MS/MS after isolation and enrichment of erythrocyte nitrosated proteins with a biotin switch approach. The results obtained suggest that catalase inhibition seen in children with obesity is partly due to the increase in the S-nitrosation of the enzyme. Indeed, exogenous administration of nitric oxide (NO) to cultured erythrocytes resulted in a decrease in catalase activity in all groups. Signals of other PTMs (O-glycosylation, Tyr-nitration and S-glutathionylation) were also detected in the erythrocyte catalase in every groups, although levels of catalase O-glycosylation and S-glutathionylation decreased in ObIR+. No evidence of differences in Tyr-nitration of catalase levels were found among groups. The study again highlights the role of erythrocytes as sensors of the inflammatory and pro-oxidant response to which these cells are subjected in children with obesity and insulin resistance.

Blunted Reducing Power Generation in Erythrocytes Contributes to Oxidative Stress in Prepubertal Obese Children with Insulin Resistance.

Childhood obesity, and specifically its metabolic complications, are related to deficient antioxidant capacity and oxidative stress. Erythrocytes are constantly exposed to multiple sources of oxidative stress; hence, they are equipped with powerful antioxidant mechanisms requiring permanent reducing power generation and turnover. Glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) are two key enzymes on the pentose phosphate pathway. Both enzymes supply reducing power by generating NADPH, which is essential for maintaining the redox balance within the cell and the activity of other antioxidant enzymes. We hypothesized that obese children with insulin resistance would exhibit blunted G6PDH and 6PGDH activities, contributing to their erythrocytes' redox status imbalances. We studied 15 control and 24 obese prepubertal children, 12 of whom were insulin-resistant according to an oral glucose tolerance test (OGTT). We analyzed erythroid malondialdehyde (MDA) and carbonyl group levels as oxidative stress markers. NADP+/NADPH and GSH/GSSG were measured to determine redox status, and NADPH production by both G6PDH and 6PGDH was assayed spectrophotometrically to characterize pentose phosphate pathway activity. Finally, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GR) activities were also assessed. As expected, MDA and carbonyl groups levels were higher at baseline and along the OGTT in insulin-resistant children. Both redox indicators showed an imbalance in favor of the oxidized forms along the OGTT in the insulin-resistant obese group. Additionally, the NADPH synthesis, as well as GR activity, were decreased. H2O2 removing enzyme activities were depleted at baseline in both obese groups, although after sugar intake only metabolically healthy obese participants were able to maintain their catalase activity. No change was detected in SOD activity between groups. Our results show that obese children with insulin resistance present higher levels of oxidative damage, blunted capacity to generate reducing power, and hampered function of key NADPH-dependent antioxidant enzymes.

Hybrid Closed-Loop System Achieves Optimal Perioperative Glycemia in a Boy With Type 1 Diabetes: A Case Report.

The goal in type 1 diabetes (T1D) therapy is to maintain optimal glycemic control under any circumstance. Diabetes technology is in continuous development to achieve this goal. The most advanced Food and Drug Administration- and European Medicines Agency-approved devices are hybrid closed-loop (HCL) systems, which deliver insulin subcutaneously in response to glucose levels according to an automated algorithm. T1D is frequently encountered in the perioperative period. The latest international guidelines for the management of children with diabetes undergoing surgery include specific adjustments to the patient's insulin therapy, hourly blood glucose monitoring, and intravenous (IV) insulin infusion. However, these guidelines were published while the HCL systems were still marginal. We present a case of a 9-year-old boy with long-standing T1D, under HCL system therapy for the last 9 months, and needing surgery for an appendectomy. We agreed with the family, the surgical team, and the anesthesiologists to continue HCL insulin infusion, without further adjustments, hourly blood glucose checks or IV insulin, while monitoring closely. The HCL system was able to keep glycemia within range for the total duration of the overnight fast, the surgery, and the initial recovery, without any external intervention or correction bolus. This is, to the best of our knowledge, the first reported pediatric case to undergo major surgery using a HCL system, and the results were absolutely satisfactory for the patient, his family, and the medical team. We believe that technology is ripe enough to advocate for a "take your pump to surgery" message, minimizing the impact and our interventions. The medical team may discuss this possibility with the family and patients.

Respiratory adverse events during upper digestive endoscopies in children under ketamine sedation.

BACKGROUND: There is no evidence of the need for oxygen supplementation during upper digestive endoscopies under ketamine sedation in children, and the latest recommendations specifically state that it is not mandatory for the procedure. The aim of our study is to assess the incidence of respiratory adverse events during upper digestive endoscopies in children under Ketamine sedation when performed without oxygen supplementation, in accordance with the latest recommendations. METHODS: Eighty-eight children undergoing ketamine sedation for programmed upper digestive endoscopy at our Pediatric Intensive Care Unit were included. Patients needing other sedative agents different from ketamine were excluded. No patients received previous oxygen therapy. Suction equipment, oxygen, a bag-valve-mask, and age-appropriate equipment for advanced airway management were immediately available. The primary outcome measure was the incidence of desaturation episodes (i.e. FiO2 below 90% requiring an intervention). RESULTS: Fifty-five patients (62.5%) presented a desaturation episode during the procedure. Most desaturation episodes occurred during the endoscope introduction (78.2%), and 5 episodes were previous to the endoscope introduction (minute 0). Around sixty percent of patients (58.9%) required oxygen therapy and four patients required bag-mask ventilation. Once oxygen therapy was initiated, 34 patients (70.5%) required it during the complete procedure or part of it. CONCLUSIONS: Desaturation episodes occur frequently early on in the procedure. Our data suggest that the role of oxygen supplementation prior to, and during upper digestive endoscopies under ketamine sedation in children should be thoroughly assessed for future recommendations.