Nucleotide regulation of vascular system

Previously, acyl derivatives of CoA were shown to antagonise human native and recombinant P2Y1 purine receptors. The main aim of this thesis was to study the effect of these endogenous nucleotide derivatives at endogenous P2Y1 receptors in blood vessels. Using isometric tension recordings, CoA, acetyl-CoA and palmitoyl-CoA (PaCoA) appeared to show selectivity for P2Y1 receptors (over P2Y2 and adenosine receptors) in the rat isolated thoracic aorta, with PaCoA being the most potent of the CoA derivatives used. In porcine isolated mesenteric arteries (PMA) and porcine isolated coronary arteries (PCA), isometric tension recordings indicated that ADP mediated endothelium-dependent and endothelium-independent relaxations, respectively. Relaxations in PMA were blocked by the P2Y1 receptor antagonist MRS2500 and PaCoA, whilst these were ineffective against ADP relaxations in the PCA. A FlexStation was used to monitor calcium responses in native HEK293 cells expressing P2Y1 and P2Y2 receptors using ADP and UTP, respectively. Responses to UTP were not significantly altered in the presence of PaCoA. In contrast, ADP-evoked responses were significantly inhibited in the presence of either MRS2500 or PaCoA. These data raise the possibility of an endogenous selective antagonism of P2Y1 receptors via CoA compounds, irrespective of species or cellular environment. Nicotinamide adenine dinucleotide (NAD) is an intracellular nucleotide which has been identified as an agonist at P2Y1, P2Y11, P2X and adenosine receptors. NAD evoked endothelium-independent concentration-dependent contractions of the pre-contracted PMA, which were unaltered in the presence of PaCoA. In contrast, αβ-methylene ATP (a desensitizing P2X receptor agonist) significantly reduced these responses suggesting the involvement of P2X1-like receptors. In both RTA and PCA, NAD evoked endothelium-independent concentration-dependent relaxations of the pre-contracted vessels, which were attenuated by SCH58261, but not PaCoA, which suggests the involvement of smooth muscle A2A receptors. These results together emphasise the possibility of a tissue and receptor-specific role of NAD as an endogenous extracellular nucleotide in purinergic signalling

Effects of NAD at purine receptors in isolated blood vessels

Nicotinamide adenine dinucleotide (NAD) belongs to the family of naturally occurring adenine dinucleotides, best known for their various intracellular roles. However, there is evidence that they can also be released from cells to act as novel extracellular signalling molecules. Relatively little is known about the extracellular actions of NAD, especially in the cardiovascular system. The present study investigated the actions of NAD in the rat thoracic aorta, porcine coronary artery and porcine mesenteric arteries, mounted in organ baths for isometric tension recording. In the rat thoracic aorta and porcine coronary artery, NAD caused endothelium-independent concentration-dependent vasorelaxations which were unaffected by palmitoylCoA, a P2Y1 receptor antagonist, but which were blocked by CGS15943, a non-selective adenosine receptor antagonist. In the porcine coronary artery, NAD-evoked relaxations were abolished by SCH58261, a selective A2A receptor antagonist. In the rat thoracic aorta, NAD-evoked relaxations were attenuated by A2A receptor antagonism with SCH58261 but were unaffected by an A2B receptor antagonist, MRS1754. In contrast, in the porcine mesenteric artery, NAD-evoked endothelium-independent contractions, which were unaffected by a P2 receptor antagonist, suramin, or by NF449, a P2X1 receptor antagonist, but were attenuated following P2X receptor desensitisation with αβ-meATP. In conclusion, the present results show that NAD can alter vascular tone through actions at purine receptors in three different arteries from two species; its molecular targets differ according to the type of blood vessel

Awareness and prevalence of metabolic syndrome among high-risk individuals attending internal medicine clinics across Jordan

Purpose: To examine the prevalence and awareness of metabolic syndrome (MetS) in high-risk individuals attending 30 internal medicine clinics in Amman, Jordan, and also to evaluate the various factors associated with increased risk of MetS among them.Methods: This retrospective cross-sectional study was carried out across Amman, Jordan from October to December 2014. During the study period, 900 high-risk individuals (with hypertension, diabetes, central obesity and/or dyslipidemia) were recruited from thirty internal medicine clinics in Amman, Jordan. Data collection forms were filled based on patient interview and medical case file.Results: The prevalence of MetS among high-risk individuals was around 40 % (361/900), with around 79 % (284/361) of MetS patients unaware of their condition. Older age, lower income and family history of premature cardiovascular diseases were associated with a higher prevalence of MetS.Conclusion: Although MetS was found to be highly prevalent among high-risk individuals in this study, the awareness of the condition in this group is very poor. These findings support the need for educational programs that involve both health care providers and patients. These programs should especially target those at risk of MetS, in order to improve awareness of the concept of MetS.Keywords: Prevalence, Metabolic syndrome, Jordan, Awareness, Risk factor

Parental views of antibiotic use in children with upper respiratory tract infections in Jordan

Purpose: To assess the knowledge, attitudes and practices of parents towards antibiotics use for upper respiratory tract infections (URTIs) in Jordan.Methods: A cross-sectional study was carried out at 10 private outpatients’ pediatric clinics across Amman-Jordan from September to December 2013. During the study period, 1329 parents of young children who fulfilled the inclusion criteria and agreed to participate were interviewed, and completed a validated structured questionnaire.Results: A large proportion of parents (903, 68 %) believed that weather change was the main cause of acute URTIs in their children. Although 1098 (82.8 %) of parents were aware that the recurrent use of antibiotics leads to a decrease in effectiveness due to bacterial resistance, 859 (64.6 %) of the respondents reported that they would give antibiotics without prescription. Fathers (135, 40.2 %), were significantly more aware that URTIs follow its natural course without antibiotic administration compared to mothers (N = 327, 32.9 %), respectively (p = 0.005).Conclusion: There is a lack of adequate parental knowledge concerning the use and misuse of antibiotics in children in Jordan. National publicity campaign should be mounted to improve awareness. Furthermore, existing laws should be enforced to prevent parents from purchasing antibiotics over-thecounter (OTC).Keywords: Antibiotics, Attitude, Knowledge, Parents, Upper respiratory tract infections, Publicity campaig

Factors associated with lipid control in outpatients with heart failure

BackgroundDyslipidemia is common among patients with heart failure, and it negatively impacts clinical outcomes. Limited data regarding the factors associated with poor lipid control in patients with HF patients. Therefore, this study aimed to evaluate lipid control and to explore the factors associated with poor lipid control in patients with HF.MethodsThe current cross-sectional study was conducted at outpatient cardiology clinics at two major hospitals in Jordan. Variables including socio-demographics, biomedical variables, in addition to disease and medication characteristics were collected using medical records and custom-designed questionnaire. Medication adherence was assessed using the validated 4-item Medication Adherence Scale. Binary logistic regression analysis was conducted to explore significant and independent predictors of poor lipid control among the study participants.ResultsA total of 428 HF patients participated in the study. Results showed that 78% of the participants had poor lipid control. The predictors that were associated with poor lipid control included uncontrolled BP (OR = 0.552; 95% CI: 0.330–0.923; P < 0.05), higher Hb levels (OR = 1.178; 95% CI: 1.013–1.369; P < 0.05), and higher WBC (OR = 1.133; 95% CI: 1.031–1.246; P < 0.05).ConclusionsThis study revealed poor lipid control among patients with HF. Future intervention programs should focus on blood pressure control in order to improve health outcomes among HF patients with dyslipidemia

Structural and Electrical Remodeling of the Sinoatrial Node in Diabetes: New Dimensions and Perspectives

The sinoatrial node (SAN) is composed of highly specialized cells that mandate the spontaneous beating of the heart through self-generation of an action potential (AP). Despite this automaticity, the SAN is under the modulation of the autonomic nervous system (ANS). In diabetes mellitus (DM), heart rate variability (HRV) manifests as a hallmark of diabetic cardiomyopathy. This is paralleled by an impaired regulation of the ANS, and by a pathological remodeling of the pacemaker structure and function. The direct effect of diabetes on the molecular signatures underscoring this pathology remains ill-defined. The recent focus on the electrical currents of the SAN in diabetes revealed a repressed firing rate of the AP and an elongation of its tracing, along with conduction abnormalities and contractile failure. These changes are blamed on the decreased expression of ion transporters and cell-cell communication ports at the SAN (i.e., HCN4, calcium and potassium channels, connexins 40, 45, and 46) which further promotes arrhythmias. Molecular analysis crystallized the RGS4 (regulator of potassium currents), mitochondrial thioredoxin-2 (reactive oxygen species; ROS scavenger), and the calcium-dependent calmodulin kinase II (CaMKII) as metabolic culprits of relaying the pathological remodeling of the SAN cells (SANCs) structure and function. A special attention is given to the oxidation of CaMKII and the generation of ROS that induce cell damage and apoptosis of diabetic SANCs. Consequently, the diabetic SAN contains a reduced number of cells with significant infiltration of fibrotic tissues that further delay the conduction of the AP between the SANCs. Failure of a genuine generation of AP and conduction of their derivative waves to the neighboring atrial myocardium may also occur as a result of the anti-diabetic regiment (both acute and/or chronic treatments). All together, these changes pose a challenge in the field of cardiology and call for further investigations to understand the etiology of the structural/functional remodeling of the SANCs in diabetes. Such an understanding may lead to more adequate therapies that can optimize glycemic control and improve health-related outcomes in patients with diabetes

Adherence to Azathioprine/6-Mercaptopurine in Children and Adolescents with Inflammatory Bowel Diseases: A Multimethod Study

Background: Measurement of the degree of adherence is a key element for the evaluation of treatment efficacy and safety; thus, adherence plays an important role in clinical research and practice. The aim of this study was to investigate medication adherence in children with inflammatory bowel disease (IBD) utilizing a multimethod assessment approach. A further aim was to examine factors that can influence adherence within this population. Methods: Medication adherence in 47 children (age range 3 to 17 years) with IBD in three centers in Northern Ireland and Jordan was assessed via subjective (parent and child versions of the Medication Adherence Report Scale (MARS) specific questionnaire) and objective methods, that is, high-performance liquid chromatography (HPLC) determination of the 6-mercaptopurine (6-MP) and azathioprine (AZA) metabolites in packed red blood cell samples taken during a clinic visit. Beliefs about prescribed medicines were also assessed in parents/guardians using the Beliefs about Medicines Questionnaire (BMQ). Results: An overall nonadherence to AZA/6-MP therapy in children with IBD was found to be 36.17% (17 out of 47 patients were classified as nonadherent using at least one of the assessment methods). A total of 41 patients (91.1%) were classified as adherent to AZA or 6-MP using the blood sampling, while adherence rates using the MARS questionnaire completed by children and parents/guardians were 60.6% and 72.7%, respectively. The latter provides a more longitudinal measure of adherence. Child self-reported nonadherence rates were significantly higher than parent/guardian reported rates (p=0.013). Binary logistic regression analysis identified age to be independently predictive of adherence, with adolescents (children aged ≥ 13 years old) more likely to be classified as nonadherent. Regarding the BMQ, when parental/guardian necessity beliefs outweighed concerns, that is, higher scores in the necessity-concern differential (NCD), adolescents were more likely to be classified as adherent. Conclusion: Results provide evidence for ongoing adherence challenges in the paediatric population with IBD. It is recommended that parents/guardians (particularly of older children) and older children themselves, should receive enhanced counselling and education about their prescribed medicines

Adherence to 6-Mercaptopurine in children and adolescents with Acute Lymphoblastic Leukemia

OBJECTIVE: Studies on children with Acute Lymphoblastic Leukemia (ALL) reported non-adherence in 2–54% of cases. The primary objective of this study was to assess rates of adherence to 6-MP using two different methods in children and adolescents with ALL. Secondary aim was to identify factors that influence adherence to 6-MP in children with ALL. METHODS: All eligible children with ALL who are (≤ 19) years old and receive 6-MP therapy for at least 1 month were approached to participate in the study. A total of 52 children with ALL and their primary caregivers were recruited. Adherence measures included an objective method (measuring 6-MP metabolites in packed Red Blood Cells (RBCs)) and a subjective method (using parent and child self-report via the Medication Adherence Report Scale; MARS; Adherence was defined as 90% or greater). RESULTS: Rates of adherence varied across the measurement methods. Packed RBCs sample analysis indicated forty-four patients (84.6%) to be adherent. Using the MARS questionnaires, a total of 49 children (94.2%) were classified as being adherent according to the parental MARS questionnaire scores, while all the 15 children (100%) who answered the MARS (child) questionnaire were classified as adherent. Overall adherence rate was 80.8% within the studied population. CONCLUSION: MARS scale was shown to overestimate adherence compared to measurement of 6-MP metabolites in the blood. A combination of both methods led to increased detection of non-adherence to thiopurine in children with ALL

Corrigendum: Evolution, ecology, and zoonotic transmission of betacoronaviruses: A review

In the published article, there was an error in the legend for Figure 1 as published. The figure legend did not indicate that it has been adapted from Plowright et al. (2017). Copyright permission was obtained from Springer Nature to adapt Figure 1 from Plowright et al. (2017). The corrected legend appears below. Figure 1. Zoonotic risk distribution, pathway to spillover, and the multimodal role of the determinants of spillover. The zoonotic risk is demonstrated by the accumulated distribution of reservoir hosts and vectors that play a role in the pathway to spillover. The risk of spillover is determined by a series of processes from the ecological dynamics of reservoir host distribution and density, to the susceptibility, replication and dissemination of the biological factors in the recipient host. This is also reflected in the multimodal role of the determinants of spillover, demonstrating the disciplines that are being used to study zoonotic transmission and the determinants of spillover. This figure was adapted from Figure 1 in Plowright et al. (2). Copyright permission was obtained with license number 55218980848529. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated