60 research outputs found
Carbon nanospheres mediated delivery of nuclear matrix protein SMAR 1 to direct experimental autoimmune encephalomyelitis in mice
Owing to the suppression of immune responses and associated side effects, steroid based treatments for inflammatory encephalitis disease can be detrimental. Here, we demonstrate a novel carbon nanosphere (CNP) based treatment regime for encephalomyelitis in mice by exploiting the functional property of the nuclear matrix binding protein SMAR1. A truncated part of SMAR1 ie, the DNA binding domain was conjugated with hydrothermally synthesized CNPs. When administered intravenously, the conjugate suppressed experimental animal encephalomyelitis in T cell specific conditional SMAR1 knockout mice (SMAR-/-). Further, CNP-SMAR1 conjugate delayed the onset of the disease and reduced the demyelination significantly. There was a significant decrease in the production of IL-17 after re-stimulation with MOG. Altogether, our findings suggest a potential carbon nanomaterial based therapeutic intervention to combat Th17 mediated autoimmune diseases including experimental autoimmune encephalomyelitis
Evaluation of the effect of lycopene on lipid profile, serum antioxidant enzymes and blood sugar level in New Zealand white rabbits
Background: Dyslipidaemias are the major cause of increased atherogenesis. Lycopene is a pigment that imparts red colour to fruits and vegetables like tomatoes. Risk of cardiovascular diseases has been shown to decrease with dietary intake of tomatoes. Although the antioxidant and hypolipidaemic properties of tomatoes have been studied extensively, beneficial effect of pure lycopene supplement as hypolipidaemic is still debatable So, we aimed to evaluate the effect of pure lycopene powder on lipid profile, serum antioxidant enzymes and blood sugar level in hyperlipidaemic rabbits.Methods: Adult male New Zealand White rabbits (1.5-2.5kg) were divided into three groups of six each. Group I-High Fat Diet (HFD) (5ml/kg). Group II-HFD (5ml/kg) + lycopene (10mg/kg) orally. Group III-HFD (5ml/kg) + lycopene (20mg/kg) orally. Blood samples were taken from all rabbits for baseline estimations of serum lipids, serum superoxide dismutase (SOD) and blood sugar. Same tests were performed after six weeks.Results: There was significant decrease in the levels of serum TC, LDL-C, TG and VLDL and an increase in serum HDL-C and antioxidant SOD with lycopene administration. However, significant increase in HDL was not seen with lycopene 10mg. TG and VLDL levels were significantly less with 20mg lycopene compared to 10mg lycopene. There was however no change in blood sugar level with lycopene.Conclusions: Pure lycopene supplement showed significant hypolipidaemic and antioxidant activity. However, it did not show significant effect on blood glucose levels
Density functional investigations of defect induced mid-gap states in graphane
We have carried out ab initio electronic structure calculations on graphane
(hydrogenated graphene) with single and double vacancy defects. Our analysis of
the density of states reveal that such vacancies induce the mid gap states and
modify the band gap. The induced states are due to the unpaired electrons on
carbon atoms. Interestingly the placement and the number of such states is
found to be sensitive to the distance between the vacancies. Furthermore we
also found that in most of the cases the vacancies induce a local magnetic
moment.Comment: 15 page
Study of effects of donepezil and aspirin on working memory in rats using electroconvulsive shock model
Background: Memory is the most common cognitive ability lost with dementia commonly seen in Alzheimer’s disease (AD). Donepezil was the first cholinesterase inhibitor to be licensed in UK for AD. There is preliminary evidence that aspirin decreases the risk and delays the onset of AD. Low dose aspirin users had numerically lower prevalence of Alzheimer’s dementia and had better cognitive function than non-users.Methods: Retention of conditioned avoidance response (CAR) was assessed by using repeated electroconvulsive shocks (ECS) in rats. Rats were divided into five groups: control (pretreated with distilled water), ECS (150 V, 50 Hz, with intensity of 210 mA for 0.5 sec) pretreated, combined aspirin (6.75 mg/kg) and pretreated ECS, combined donepezil (0.32 mg/kg) and pretreated ECS, combined aspirin, donepezil and pretreated ECS groups. Data were analyzed using the Chi-square test and ANOVA.Results: Findings show that administration of ECS daily for 8 days results in transient amnesia and disruption of retention of CAR. Aspirin and donepezil administration significantly increased the retention of CAR in comparison to ECS. However, aspirin failed to show an increase in the retention of CAR as compared to donepezil. The combination of the two drugs showed statistically significant increase in the retention of CAR than either of these drugs given alone.Conclusion: Neuroinflammation plays an important role in the pathophysiology of neurodegenerative disorder like AD. Combination of aspirin with donepezil increased the nootropic and neuroprotective effect of aspirin and thus may hold great clinical significance in such disorders
Global Gene Expression Associated with Hepatocarcinogenesis in Adult Male Mice Induced by in Utero Arsenic Exposure
Our previous work has shown that exposure to inorganic arsenic in utero produces hepatocellular carcinoma (HCC) in adult male mice. To explore further the molecular mechanisms of transplacental arsenic hepatocarcinogenesis, we conducted a second arsenic transplacental carcinogenesis study and used a genomewide microarray to profile arsenic-induced aberrant gene expression more extensively. Briefly, pregnant C3H mice were given drinking water containing 85 ppm arsenic as sodium arsenite or unaltered water from days 8 to 18 of gestation. The incidence of HCC in adult male offspring was increased 4-fold and tumor multiplicity 3-fold after transplacental arsenic exposure. Samples of normal liver and liver tumors were taken at autopsy for genomic analysis. Arsenic exposure in utero resulted in significant alterations (p < 0.001) in the expression of 2,010 genes in arsenic-exposed liver samples and in the expression of 2,540 genes in arsenic-induced HCC. Ingenuity Pathway Analysis revealed that significant alterations in gene expression occurred in a number of biological networks, and Myc plays a critical role in one of the primary networks. Real-time reverse transcriptase–polymerase chain reaction and Western blot analysis of selected genes/proteins showed > 90% concordance. Arsenic-altered gene expression included activation of oncogenes and HCC biomarkers, and increased expression of cell proliferation–related genes, stress proteins, and insulin-like growth factors and genes involved in cell–cell communications. Liver feminization was evidenced by increased expression of estrogen-linked genes and altered expression of genes that encode gender-related metabolic enzymes. These novel findings are in agreement with the biology and histology of arsenic-induced HCC, thereby indicating that multiple genetic events are associated with transplacental arsenic hepatocarcinogenesis
Human P2Y 6 Receptor: Molecular Modeling Leads to the Rational Design of a Novel Agonist Based on a Unique Conformational Preference
Combining molecular dynamics (MD) in a hydrated phospholipids (DOPC) bilayer, Monte Carlo search, and synthesis of locked nucleotide analogues we discovered that the Southern conformation of the ribose is preferred for ligand recognition by the P2Y6 receptor. 2′-Deoxy-(S)-methanocarbaUDP was found to be a full agonist of the receptor and displayed a 10-fold higher potency than the corresponding flexible 2′-deoxyUDP. MD results also suggested a conformational change of the second extracellular loop consequent to agonist binding
Positive Inotropic Effects by Uridine Triphosphate (UTP) and Uridine Diphosphate (UDP) via P2Y2 and P2Y6 Receptors on Cardiomyocytes and Release of UTP in Man During Myocardial Infarction
The aim of this study was to examine a possible role for extracellular pyrimidines as inotropic factors for the heart. First, nucleotide plasma levels were measured to evaluate whether UTP is released in patients with coronary heart disease. Then, inotropic effects of pyrimidines were examined in isolated mouse cardiomyocytes. Finally, expression of pyrimidine-selective receptors (a subgroup of the P2 receptors) was studied in human and mouse heart, using real time polymerase chain reaction, Western blot, and immunohistochemistry. Venous plasma levels of UTP were increased (57%) in patients with myocardial infarction. In electrically stimulated cardiomyocytes the stable P2Y2/4 agonist UTPγS increased contraction by 52%, similar to β1-adrenergic stimulation with isoproterenol (65%). The P2Y6-agonist UDPγS also increased cardiomyocyte contraction (35%), an effect abolished by the P2Y6-blocker MRS2578. The phospholipase C inhibitor {"type":"entrez-nucleotide","attrs":{"text":"U73122","term_id":"4098075","term_text":"U73122"}}U73122 inhibited both the UDPγS and the UTPγS-induced inotropic effect, indicating an IP3-mediated effect via P2Y6 receptors. The P2Y14 agonist UDP-glucose was without effect. Quantification of mRNA with real time polymerase chain reaction revealed P2Y2 as the most abundant pyrimidine receptor expressed in cardiomyocytes from man. Presence of P2Y6 receptor mRNA was detected in both species and confirmed at protein level with Western blot and immunohistochemistry in man. In conclusion, UTP levels are increased in humans during myocardial infarction, giving the first evidence for UTP release in man. UTP is a cardiac inotropic factor most likely by activation of P2Y2 receptors in man. For the first time we demonstrate inotropic effects of UDP, mediated by P2Y6 receptors via an IP3-dependent pathway. Thus, the extracellular pyrimidines (UTP and UDP) could be important inotropic factors involved in the development of cardiac disease
Antiaggregatory activity in human platelets of potent antagonists of the P2Y1 receptor
Activation of the P2Y1 nucleotide receptor in platelets by ADP causes changes in shape and aggregation, mediated by activation of phospholipase C (PLC). Recently, MRS2500 (2-iodo-N6-methyl-(N)-methanocarba-2′-deoxyadenosine-3′,5′-bisphosphate) was introduced as a highly potent and selective antagonist for this receptor. We have studied the actions of MRS2500 in human platelets and compared these effects with the effects of two acyclic nucleotide analogues, a bisphosphate MRS2298 and a bisphosphonate derivative MRS2496, which act as P2Y1 receptor antagonists, although less potently than MRS2500. Improved synthetic methods for MRS2500 and MRS2496 were devised. The bisphosphonate is predicted to be more stable in general in biological systems than phosphate antagonists due to the non-hydrolyzable C–P bond. MRS2500 inhibited the ADP-induced aggregation of human platelets with an IC50 value of 0.95 nM. MRS2298 and MRS2496 also both inhibited the ADP-induced aggregation of human platelets with IC50 values of 62.8 nM and 1.5 μM, respectively. A similar order of potency was observed for the three antagonists in binding to the recombinant human P2Y1 receptor and in inhibition of ADP-induced shape change and ADP-induced rise in intracellular Ca2+. No substantial antagonism of the pathway linked to the inhibition of cyclic AMP was observed for the nucleotide derivatives, indicating no interaction of these three P2Y1 receptor antagonists with the proaggregatory P2Y12 receptor, which is also activated by ADP. Thus, all three of the bisphosphate derivatives are highly selective antagonists of the platelet P2Y1 receptor, and MRS2500 is the most potent such antagonist yet reported
Molecular recognition in the P2Y14 receptor: Probing the structurally permissive terminal sugar moiety of uridine-5′-diphosphoglucose
The P2Y14 receptor, a nucleotide signaling protein, is activated by uridine-5′-diphosphoglucose 1 and other uracil nucleotides. We have determined that the glucose moiety of 1 is the most structurally permissive region for designing analogues of this P2Y14 agonist. For example, the carboxylate group of uridine-5′-diphosphoglucuronic acid proved to be suitable for flexible substitution by chain extension through an amide linkage. Functionalized congeners containing terminal 2-acylaminoethylamides prepared by this stratgegy retained P2Y14 activity, and molecular modeling predicted close proximity of this chain to the 2nd extracellular loop of the receptor. In addition, replacement of glucose with other sugars did not diminish P2Y14 potency. For example, the [5″]ribose derivative had an EC50 of 0.24 μM. Selective monofluorination of the glucose moiety indicated a role for the 2″- and 6″-hydroxyl groups of 1 in receptor recognition. The β-glucoside was 2-fold less potent than the native α-isomer, but methylene replacement of the 1″-oxygen abolished activity. Replacement of the ribose ring system with cyclopentyl or rigid bicyclo[3.1.0]hexane groups abolished activity. Uridine-5′-diphosphoglucose also activates the P2Y2 receptor, but the 2-thio analogue and several of the potent modified-glucose analogues were P2Y14-selective
Global, regional, and national burden of stroke and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019
Background
Regularly updated data on stroke and its pathological types, including data on their incidence, prevalence, mortality, disability, risk factors, and epidemiological trends, are important for evidence-based stroke care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) aims to provide a standardised and comprehensive measurement of these metrics at global, regional, and national levels.
Methods
We applied GBD 2019 analytical tools to calculate stroke incidence, prevalence, mortality, disability-adjusted life-years (DALYs), and the population attributable fraction (PAF) of DALYs (with corresponding 95% uncertainty intervals [UIs]) associated with 19 risk factors, for 204 countries and territories from 1990 to 2019. These estimates were provided for ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and all strokes combined, and stratified by sex, age group, and World Bank country income level.
Findings
In 2019, there were 12·2 million (95% UI 11·0–13·6) incident cases of stroke, 101 million (93·2–111) prevalent cases of stroke, 143 million (133–153) DALYs due to stroke, and 6·55 million (6·00–7·02) deaths from stroke. Globally, stroke remained the second-leading cause of death (11·6% [10·8–12·2] of total deaths) and the third-leading cause of death and disability combined (5·7% [5·1–6·2] of total DALYs) in 2019. From 1990 to 2019, the absolute number of incident strokes increased by 70·0% (67·0–73·0), prevalent strokes increased by 85·0% (83·0–88·0), deaths from stroke increased by 43·0% (31·0–55·0), and DALYs due to stroke increased by 32·0% (22·0–42·0). During the same period, age-standardised rates of stroke incidence decreased by 17·0% (15·0–18·0), mortality decreased by 36·0% (31·0–42·0), prevalence decreased by 6·0% (5·0–7·0), and DALYs decreased by 36·0% (31·0–42·0). However, among people younger than 70 years, prevalence rates increased by 22·0% (21·0–24·0) and incidence rates increased by 15·0% (12·0–18·0). In 2019, the age-standardised stroke-related mortality rate was 3·6 (3·5–3·8) times higher in the World Bank low-income group than in the World Bank high-income group, and the age-standardised stroke-related DALY rate was 3·7 (3·5–3·9) times higher in the low-income group than the high-income group. Ischaemic stroke constituted 62·4% of all incident strokes in 2019 (7·63 million [6·57–8·96]), while intracerebral haemorrhage constituted 27·9% (3·41 million [2·97–3·91]) and subarachnoid haemorrhage constituted 9·7% (1·18 million [1·01–1·39]). In 2019, the five leading risk factors for stroke were high systolic blood pressure (contributing to 79·6 million [67·7–90·8] DALYs or 55·5% [48·2–62·0] of total stroke DALYs), high body-mass index (34·9 million [22·3–48·6] DALYs or 24·3% [15·7–33·2]), high fasting plasma glucose (28·9 million [19·8–41·5] DALYs or 20·2% [13·8–29·1]), ambient particulate matter pollution (28·7 million [23·4–33·4] DALYs or 20·1% [16·6–23·0]), and smoking (25·3 million [22·6–28·2] DALYs or 17·6% [16·4–19·0]).
Interpretation
The annual number of strokes and deaths due to stroke increased substantially from 1990 to 2019, despite substantial reductions in age-standardised rates, particularly among people older than 70 years. The highest age-standardised stroke-related mortality and DALY rates were in the World Bank low-income group. The fastest-growing risk factor for stroke between 1990 and 2019 was high body-mass index. Without urgent implementation of effective primary prevention strategies, the stroke burden will probably continue to grow across the world, particularly in low-income countries.publishedVersio
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