Circulating ceramide levels and ratios in Emirati youth under 18 years: associations with cardiometabolic risk factors.

BACKGROUND: Circulating ceramide (Cer) drives various pathological processes associated with cardiovascular diseases, liver illness, and diabetes mellitus. Although recognized as predictors of cardiometabolic diseases (CMD) in research and clinical settings, their potential for predicting CMD risk in individuals under 18 remains unexplored. OBJECTIVES: This study was designed to utilize Liquid Chromatography-Mass Spectrometry (LC-MS/MS) methodology to determine the biological reference ranges for Cer in plasma samples of Emirati children and develop a risk assessment score (CERT-1) based on Cer concentrations. METHODS: Using LC-MS/MS, we developed a method to measure five Cer species in plasma samples of 582 Emirati participants aged 5-17. We used the circulating concentrations of these Cer to determine their reference intervals in this population. We employed traditional statistical analyses to develop a risk score (CERT-1) and assess the association between Cer levels and conventional biomarkers of CMD. RESULTS: We validated a high-throughput methodology using LC-MS/MS to quantify five Cer species in human plasma. Reference values for this population (n = 582) were quantified: CerC16:0 (0.12-0.29 µmol/L), CerC18:0 (0.019-0.067 µmol/L), CerC22:0 (0.102-0.525 µmol/L), CerC24:0 (0.65-1.54 µmol/L) and CerC24:1 (0.212-0.945 µmol/L). We devised a risk assessment score (CERT-1) based on plasma Cer content in the study participants, showing that 72.5% have low to moderate risk and 9.3% are at a higher risk of developing CMD. Our analyses also revealed a significant correlation (P < 0.05) between this score and the conventional risk factors linked to CMD, indicating its potential clinical implication. CONCLUSION: This study presents a clinical-scaled LC-MS/MS methodology for assessing clinically relevant Cer, setting reference ranges, and developing a risk score (CERT-1) for young Emirati individuals. Our findings can enhance primary risk prediction and inform the management and follow-up of CMD from an early age.

Association of variants in PTPN22, CTLA-4, IL2-RA, and INS genes with type 1 diabetes in Emiratis.

Type 1 diabetes (T1D) is a chronic autoimmune disease with a complex interrelation of genetic and environmental factors. Genetic studies have reported HLA and non-HLA loci as significant contributors to T1D. However, the genetic basis of T1D among Emiratis is unexplored. This study aims to determine the contribution of four genes PTPN22, CTLA-4, IL2-RA, and INS to T1D risk among Emiratis. The association between variants in PTPN22 (rs2476601, rs1310182), CTLA-4 (rs11571316, rs231775, rs3087243, rs1427676, and rs231727), IL2-RA (rs7090530), and INS (rs7111341) with T1D was tested in 310 Emiratis (139 T1D patients and 171 controls). A significant association was found at rs1310182, and rs2476601 both in PTPN22, rs3087243, and rs231775 both in CTLA-4, and rs12251307 in IL2-RA. Moreover, a haplotype constituted from GG and AG genotypes at rs231727 and rs231775, respectively, in CTLA-4 was significantly associated with an increased T1D risk. The cumulative effects of risk alleles for all significantly associated SNPs showed 11.8 higher relative risk for T1D for those who carry 5-6 compared to 0-1 risk alleles. This study illustrated that PTPN22, CTLA-4, and IL2-RA gene variants could confer risk alleles for T1D among the Emirati population.

Life-threatening arrhythmias with autosomal recessive TECRL variants.

AIMS: Sudden death and aborted sudden death have been observed in patients with biallelic variants in TECRL. However, phenotypes have only begun to be described and no data are available on medical therapy after long-term follow-up. METHODS AND RESULTS: An international, multi-centre retrospective review was conducted. We report new cases associated with TECRL variants and long-term follow-up from previously published cases. We present 10 cases and 37 asymptomatic heterozygous carriers. Median age at onset of cardiac symptoms was 8 years (range 1-22 years) and cases were followed for an average of 10.3 years (standard deviation 8.3), right censored by death in three cases. All patients on metoprolol, bisoprolol, or atenolol were transitioned to nadolol or propranolol due to failure of therapy. Phenotypes typical of both long QT syndrome and catecholaminergic polymorphic ventricular tachycardia (CPVT) were observed. We also observed divergent phenotypes in some cases despite identical homozygous variants. None of 37 heterozygous family members had a cardiac phenotype. CONCLUSION: Patients with biallelic pathogenic TECRL variants present with variable cardiac arrhythmia phenotypes, including those typical of long QT syndrome and CPVT. Nadolol and propranolol may be superior beta-blockers in this setting. No cardiac disease or sudden death was present in patients with a heterozygous genotype.

Review findings included diminished coronary flow reserve after surgery in children with congenital heart disease and inflammation.

AIM: The aim of this review was to develop a deeper knowledge of the physiology of coronary blood flow and coronary flow reserve in young patients with congenital heart disease and inflammatory diseases. METHODS: We searched for papers published in English on coronary blood flow and coronary flow reserve using the PubMed and Google search databases. This identified 42 papers extending back to 1976 and a book from 2008 (Davis et al. Microcirculation. Boston, MA: Elsevier, 2008: 161-284). RESULTS: Our review showed that the implications of coronary blood flow and coronary flow reserve in paediatric patients with congenital heart disease and inflammatory diseases are still not fully understood. However, a key finding was that coronary flow reserve was diminished in patients with congenital heart disease and inflammation after surgery, with or without a cardiopulmonary bypass. Other findings discussed by this review relate to volume and pressure overload in acyanotic congenital heart disease, reduced myocardial perfusion and cyanotic congenital heart disease. CONCLUSION: We still have much to discover about paediatric patients with congenital heart disease and inflammatory diseases. Understanding the pathophysiology of coronary blood flow could help the postoperative treatment of such patients.

4-Aminopyridine, A Blocker of Voltage-Dependent K+ Channels, Restores Blood Pressure and Improves Survival in the Wistar Rat Model of Anaphylactic Shock.

OBJECTIVES: Anaphylactic shock is associated with severe hypotension. Potassium channel blockers, such as 4-aminopyridine, induce vasoconstriction. The objective of this study was to test the ability of 4-aminopyridine to restore blood pressure and increase survival in anaphylactic shock. DESIGN: Experimental study. SETTING: Physiology laboratory. SUBJECTS: Adult male Wistar rats. INTERVENTIONS: Rats were sensitized with ovalbumin (1 mg SC), and anaphylactic shock was induced by IV injection of ovalbumin (1 mg). Experimental groups included non-allergic rats (NA) (n = 6); allergic rats (Controls) (n = 6); allergic rats treated with 4-aminopyridine (4-aminopyridine) (1 mg/kg) (n = 6); and allergic rats treated with epinephrine (EPI) (10 µg/kg) (n = 6). Treatments were administered 1 minute after induction of anaphylactic shock. MEASUREMENTS AND MAIN RESULTS: Mean arterial blood pressure, heart rate, and survival were measured for 60 minutes. Plasma levels of histamine, leukotriene B4, prostaglandin E2, prostaglandin F2, pH, and HCO3 were measured. Mean arterial blood pressure was normal in the NA group; severe hypotension and high mortality were observed in controls; normalization of mean arterial blood pressure, heart rate, and increased survival were observed in 4-aminopyridine and EPI groups. All allergic 4-aminopyridine-treated rats survived after the induction of anaphylactic shock. Histamine level was higher in controls and the 4-aminopyridine group but reduced in the EPI group. Prostaglandin E2 increased in controls and EPI group and decreased in 4-aminopyridine group; prostaglandin F2 increased in controls but decreased in 4-aminopyridine and EPI groups. Leukotriene B4 decreased in 4-aminopyridine and EPI groups. Metabolic acidosis was prevented in the 4-aminopyridine group. CONCLUSIONS: Our data suggest that voltage-dependent K+ channel inhibition with 4-aminopyridine treatment restores blood pressure and increases survival in the Wistar rat model of anaphylactic shock. 4-aminopyridine or related voltage-dependent K channel blockers could be a useful additional therapeutic approach to treatment of refractory anaphylactic shock.

Factors influencing medical students' self-assessment of examination performance accuracy: A United Arab Emirates study.

BACKGROUND: Assessment of one's academic capabilities is essential to being an effective, self-directed, life-long learner. The primary objective of this study was to analyze self-assessment accuracy of medical students attending the College of Medicine and Health Sciences, United Arab Emirates University, by examining their ability to assess their own performance on an MCQ examination. METHODS: 1 st and 2 nd year medical students (n = 235) self-assessed pre and post-examination performance were compared with objectively measured scores (actual examination performance). Associations between accuracy of score prediction (pre and post assessment), and students' gender, year of education, perceived preparation, confidence and anxiety were also determined. RESULTS: Expected mark correlated significantly with objectively assessed marks (r = 0.407; P < 0.01) but with low predictability (R 2 = 0.166). The average objectively determined mark was 69% and the average expected mark was equivalent to 83%; indicating that students significantly overestimate their examination performance. Self-assessed pre-examination score range was significantly different between males and females (P < 0.05) with females expecting higher marks. Preparation and confidence correlated significantly with actual examination score (P < 0.05; r = 0.459 and 0.569 respectively). DISCUSSION: Gender, self-reported preparation and confidence are associated with self-assessment accuracy. Findings reinforce existing evidence indicating that medical students are poor self-assessors. There are potentially multiple explanations for misjudgment of this multidimensional construct that require further investigation and change in learning cultures. The study offers clear targets for change aimed at optimizing self-assessment capabilities.

National growth charts for United Arab Emirates children with Down syndrome from birth to 15 years of age.

BACKGROUND: Specific centile growth charts for children with Down syndrome (DS) have been produced in many countries and are known to differ from those of normal children. Since growth assessment depends on the growth pattern characteristic for these conditions, disorder-specific charts are desirable for various ethnic groups. AIMS: To provide cross-sectional weight, height, and head circumference (HC) references for healthy United Arab Emirates (UAE) children with DS. METHODS: A retrospective and cross-sectional growth study of Emirati children with DS, aged 0 to 18 years old, was conducted. Height, weight, and HC were measured in each child. Cole's LMS statistical method was applied to estimate age-specific percentiles, and measurements were compared to UAE reference values for normal children. RESULTS: Incidence of DS in the UAE population is 1 in 374 live births (267 in 10 000 live births). We analyzed 1263 growth examinations of 182 children with DS born between 1994 and 2012. The male-to-female ratio was 1.6:1. Height, weight, and HC centile charts were constructed for ages 0 to 13 years. The prevalence of overweight and obesity in DS children aged 10 to 13 years of age was 32% and 19%, respectively. The DS children were significantly shorter and heavier than normal children in the UAE. CONCLUSIONS: Weight, height, and HC growth charts were created for children with DS. These can be used as a reference standard for the UAE children with DS. Overweight and obesity are quite common in DS children ≥ 10 years of age, as DS children tend to be shorter and heavier than non-DS children.

Inhibition of murine cardiomyocyte respiration by amine local anesthetics.

The hydrophobic amino acyl amide-linked local anesthetics (e.g., lidocaine and bupivacaine) impose potent cardiac toxicity and direct mitochondrial dysfunction. To investigate these adverse events, an in vitro system was employed to measure their effects on O2 consumption (cellular respiration) by murine myocardium. Specimens were collected from the ventricular myocardium and immediately immersed in ice-cold Krebs-Henseleit buffer saturated with 95 % O2:5 % CO2. O2 concentration was determined as a function of time from the phosphorescence decay rates of Pd(II)-meso-tetra-(4-sulfonatophenyl)-tetrabenzoporphyrin. Myocardial O2 consumption was linear with time (zero-order kinetics); its rate (k, in µM O2 min(-1)), thus, was the negative of the slope of [O2] vs. time. Cyanide inhibited O2 consumption, confirming the oxidation occurred in the respiratory chain. Lidocaine and bupivacaine produced immediate and sustained inhibition of cellular respiration at plasma concentrations of the drugs (low micromolar range). Bupivacaine was twice as potent as lidocaine. The inhibition was dose-dependent, saturating at concentrations ≥30 µM. At saturating doses, lidocaine produced ~20 % inhibition and bupivacaine ~40 % inhibition. Cellular ATP was also decreased in the presence of 30 µM lidocaine or bupivacaine. The studied amines inhibited myocardial cellular respiration. This effect is consistent with their known adverse events on mitochondrial function. The described approach allows accurate assessments and comparisons of the toxic effects of local anesthetics on heart tissue bioenergetics.

Association of Biomarkers for Dyslipidemia, Inflammation, and Oxidative Stress with Endothelial Dysfunction in Obese Youths: A Case-Control Study.

Objective: The United Arab Emirates (UAE), with its characteristic local population, geography, and history, presents several risk factors for cardiovascular diseases (CVDs) in obese individuals. Obesity and its associated complications, including diabetes, atherogenic dyslipidemia, and CVDs leading to significant health risks. In the present study, "Youths" defined as young people between 18 and 22 years. We assessed dyslipidemia, inflammation, and oxidative stress biomarker levels and their association with endothelial dysfunction (ED) in both overweight/obese and normal weight youths of UAE. Methods: There were 160 youths with overweight/obese (BMI ≥ 25 kg/m2) patients and healthy age- and sex-matched normal weight (BMI ≤ 24.9 kg/m2) as controls participated in this study. The anthropometric data and blood samples were collected to assess the biomarkers for dyslipidemia, inflammation, oxidative stress, ED from all the youths. Results: The overall mean age and male-to-female ratio were 20±1.5years and 1.0:1.2, respectively. There was statistically significant difference in HDL-C (p<0.001), triglycerides (TG) (p<0.001), ApoA (p=0.002), ApoB/ApoA ratio (p=0.009) between the overweight/obese and normal weight youths. Among, inflammatory markers: hs-CRP, IL-6, TNF-α also showed significant p<0.001 and oxidative stress markers: DNA/RNA Damage, catalase and nitric oxide (NO) showed significant p<0.001 between groups. Spearman correlation of ED markers with lipid profile markers showed Vitamin C levels positively correlated with HDL-C (p<0.001) and negatively correlated with glucose (p<0.001). ICAM-1showed significant negative correlation with HDL-C (p<0.01) and ApoA (p<0.001) but positive correlation with TG (p<0.01) and HbA1c (p<0.001) among groups. Spearman correlation of ED markers with inflammatory/oxidative stress biomarkers showed Vitamin C levels negatively correlated with ferritin (p < 0.001), NO (p < 0.001), GGT (p < 0.001), and ALT (p < 0.001) levels. The ICAM-1showed significant positive correlation with hs-CRP (p < 0.01), IL-6 (p < 0.001), TNF-α (p < 0.01), GGT (p < 0.05), and ALT (p < 0.05) in both groups. Conclusion: This study revealed a strong link between the biomarkers of dyslipidemia, inflammation, and oxidative stress with ED in overweight/obese patients. This study might be used to predict future cardiovascular events in this population.

Lipid profile, inflammatory biomarkers, endothelial dysfunction, and heart rate variability in adolescents with type 1 diabetes. A case-control study among UAE population.

Background: Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by the chronic inflammation and cause of endothelial dysfunction (ED). Heart rate variability (HRV) is a marker of sympathetic and parasympathetic autonomic nervous system dysfunction. We investigated the association of lipid profile, inflammatory biomarkers, endothelial dysfunction, and heart rate variability in adolescents with T1DM among UAE population. Method: In this case-control study we recruited 126 adolescents (13-22 years) from Abu Dhabi, UAE (United Arab Emirates). Demographic, anthropometric, blood and urine samples were collected after an overnight fasting. HRV measurements were determined per Task Force recommendations. Independent t-test or Mann-Whitney U test and Pearson's Chi-squared test were used to compare groups. Adjusted conditional logistic regression model was used to identify the determinants independently associated with T1DM. Results: The mean ages in control (n = 47) and patient (n = 79) groups were 17.5 ± 4.6 and 18.6 ± 4.8 years, respectively. A family history of diabetes and waist and hip circumferences significantly differed between the groups (p = 0.030 and 0.010). The patients with T1DM exhibited significantly higher levels of atherogenic markers than control. Endothelial dysfunction biomarkers such as levels of sICAM-1 (p < 0.001), adiponectin (p < 0.001) and 25-hydroxyvitamin D (p < 0.001) were significantly different in the control group compared with those in the T1DM group. There was a significant difference in SDNN intervals, NN50, pNN50, and SD1/SD2 among the two groups. In adjusted analysis, total cholesterol (adjusted Odds Ratio (aOR): 2.78, 95 % CI:1.37-5.64; p = 0.005), LDL (2.66, 95%CI:1.19-5.92; p = 0.017), and triglycerides (5.51, 95%CI:1.57-19.41; p = 0.008) were significantly associated with developing T1DM. The HRV indicators were significantly associated with decrease odds of T1DM after controlling for SBP, BMI, and family history of DM. Conclusion: In this study, adolescents with T1DM showed a significant association with lipid profile, ED, and HRV compared with controls. Thus, an early attention to diabetes control is required to reduce the risk of cardiac autonomic neuropathy leading to various cardiovascular diseases.