Socioeconomic status and transient ischaemic attack/stroke: a prospective observational study.

BACKGROUND: Lower socioeconomic status (SES) is associated with an increased risk of stroke but the mechanisms are unclear. We aimed to determine whether low-SES stroke/transient ischaemic attack (TIA) patients have a greater burden of vascular risk factors/co-morbidity and reduced health care access. METHODS: We prospectively studied 467 consecutive stroke and TIA patients from 3 Scottish hospitals (outpatients and inpatients) during 2007/2008. We recorded vascular risk factors, stroke severity, co-morbidity measures, investigations and health service utilisation. SES was derived from postcodes using Scottish Neighbourhood Statistics and analysed in quartiles. RESULTS: TIA/stroke patients in the lowest SES quartile were younger (64 years, SD 14.1) than those in the highest quartile (72 years, SD 12.9; p < 0.0001). They were more likely to be current smokers (42 vs. 22%; p = 0.001) but there was no association with other vascular risk factors/co-morbidity. There was a trend for those with lower SES to have a more severe stroke [modified National Institutes of Health Stroke Scale score and interquartile range: 4 (2-6) vs. 3 (1-5); multivariate p = 0.05]. Lower SES groups were less likely to have neuro-imaging (82 vs. 90%; p = 0.036) or an electrocardiogram (72 vs. 87%; p = 0.003), but differences were no longer significant on multivariate analysis. However, there was equal access to stroke unit care. CONCLUSIONS: Low-SES TIA and stroke patients are younger and have a more severe deficit; an increased prevalence of smoking is likely to be a major contributor. We found equal access to stroke unit care for low-SES patients.

Cotinine, thioether, and glucuronide excretion among active and passive bidi smokers in India.

The authors examined biomarkers for environmental tobacco smoke exposure (ETS) from bidis (Indian cigarettes) among male smokers, their nonsmoking female family members (passive smokers), and an unexposed control group (N = 66). The 3 parameters used to determine the magnitude of exposure were cotinine (a tobacco-specific alkaloid indicating nicotine exposure) and thioethers and glucuronides (indicators of electrophilic burden). Urinary excretion of cotinine was significantly higher among active smokers (4.30 +/- 1.18), compared with passive smokers (wives = 1.76 +/- 0.50; daughters = 0.50 +/- 0.26). Similar trends were noted for thioethers and glucuronides. The authors found that cotinine and glucuronide levels were correlated significantly with exposure to ETS among both active and passive bidi smokers.

Ab initio and density functional theoretical design and screening of model crown ether based ligand (host) for extraction of lithium metal ion (guest): effect of donor and electronic induction.

The structures, energetic and thermodynamic parameters of model crown ethers with different donor, cavity and electron donating/ withdrawing functional group have been determined with ab initio MP2 and density functional theory in gas and solvent phase. The calculated values of binding energy/ enthalpy for lithium ion complexation are marginally higher for hard donor based aza and oxa crown compared to soft donor based thia and phospha crown. The calculated values of binding enthalpy for lithium metal ion with 12C4 at MP2 level of theory is in good agreement with the available experimental result. The binding energy is altered due to the inductive effect imparted by the electron donating/ withdrawing group in crown ether, which is well correlated with the values of electron transfer. The role of entropy for extraction of hydrated lithium metal ion by different donor and functional group based ligand has been demonstrated. The HOMO-LUMO gap is decreased and dipole moment of the ligand is increased from gas phase to organic phase because of the dielectric constant of the solvent. The gas phase binding energy is reduced in solvent phase as the solvent molecules weaken the metal-ligand binding. The theoretical values of extraction energy for LiCl salt from aqueous solution in different organic solvent is validated by the experimental trend. The study presented here should contribute to the design of model host ligand and screening of solvent for metal ion recognition and thus can contribute in planning the experiments.

DFT modeling on the suitable crown ether architecture for complexation with Cs⁺ and Sr²âº metal ions.

Crown ether architectures were explored for the inclusion of Cs(+) and Sr(2+) ions within nano-cavity of macrocyclic crown ethers using density functional theory (DFT) modeling. The modeling was undertaken to gain insight into the mechanism of the complexation of Cs(+) and Sr(2+) ion with this ligand experimentally. The selectivity of Cs(+) and Sr(2+) ions for a particular size of crown ether has been explained based on the fitting and binding interaction of the guest ions in the narrow cavity of crown ethers. Although, Di-Benzo-18-Crown-6 (DB18C6) and Di-Benzo-21-Crown-7 (DB21C7) provide suitable host architecture for Sr(2+) and Cs(+) ions respectively as the ion size match with the cavity of the host, but consideration of binding interaction along with the cavity matching both DB18C6 and DB21C7 prefers Sr(2+) ion. The calculated values of binding enthalpy of Cs metal ion with the crown ethers were found to be in good agreement with the experimental results. The gas phase binding enthalpy for Sr(2+) ion with crown ether was higher than Cs metal ion. The ion exchange reaction between Sr and Cs always favors the selection of Sr metal ion both in the gas and in micro-solvated systems. The gas phase selectivity remains unchanged in micro-solvated phase. We have demonstrated the effect of micro-solvation on the binding interaction between the metal ions (Cs(+) and Sr(2+)) and the macrocyclic crown ethers by considering micro-solvated metal ions up to eight water molecules directly attached to the metal ion and also by considering two water molecules attached to metal-ion-crown ether complexes. A metal ion exchange reaction involving the replacement of strontium ion in metal ion-crown ether complexes with cesium ion contained within a metal ion-water cluster serves as the basis for modeling binding preferences in solution. The calculated O-H stretching frequency of H(2)O molecule in micro-solvated metal ion-crown complexes is more red-shifted in comparison to hydrated metal ions. The calculated IR spectra can be compared with an experimental spectrum to determine the presence of micro-solvated metal ion-crown ether complexes in extractant phase.

Stroke presentation in Type 2 diabetes and the metabolic syndrome.

INTRODUCTION: The metabolic syndrome (MetS) is associated with macrovascular disease and an altered pattern of cerebrovascular disease. We investigated stroke subtype presentation in Type 2 diabetic (T2D) patients, and analysed patients with and without the MetS. METHODS: We performed a retrospective analysis of 243 T2D patients with first presentation of stroke from our Diabetes Centre database. The MetS was diagnosed in patients with T2D and two or more additional risk factors (obesity, low HDL cholesterol, elevated triglycerides or hypertension). We analysed the clinical stroke subtype presentation, using the Oxford classification of stroke, into cortical and lacunar (small vessel disease) stroke. RESULTS: The MetS was diagnosed in 151 T2D patients (62%), with 86 male and 65 female patients (age: 71.8+/-9.7). Comparing the MetS and non-MetS groups, the distribution of stroke subtypes adjusted for age and sex were: cortical stroke (13.2% versus 15.2%; P=0.56), lacunar stroke (43.7% versus 43.5%; P=0.87) and TIA (38.4% versus 39.1%; P=0.98). Lacunar stroke incidence was significantly higher compared to cortical stroke in both groups (P<0.001). CONCLUSION: In this study of T2D patients, lacunar stroke (small vessel disease) was the most common stroke subtype in both patients with and without the MetS.