Prevalence and behavioural risk factors for hepatitis B in Upper Dolpo,Nepal

Journal of Public Health - Nepal is a country of low endemicity for chronic hepatitis B, with a prevalence of 0.9%. However, in Dolpo District, a higher prevalence of hepatitis B virus (HBV) was...     

Positive inotropic effects of epigallocatechin-3-gallate (EGCG) involve activation of Na+/H+ and Na+/Ca2+ exchangers

BACKGROUND: There is evidence that the tea catechin epigallocatechin-3-gallate (EGCG) modulates myocardial contractility. However, the underlying mechanisms remain to be determined. AIMS: To study potential signalling pathways involved in EGCG-induced contractile parameters. METHODS AND RESULTS: EGCG increased fractional shortening in rat cardiac myocytes and enhanced intracellular systolic Ca2+ concentrations. In isolated rat hearts, perfusion with EGCG resulted in significant, dose-dependent increase in peak systolic left ventricular pressure, as well as in contraction and relaxation velocities. Heart rate did not change. Inhibition of the beta1-receptor with metoprolol had no influence on the contractile effects of EGCG. Furthermore, levels of cAMP and phosphorylation of phospholamban did not change with EGCG, indicating that the beta-receptor pathway is not involved. The L-type Ca2+ channel inhibitors, nifedipine and gallopamil, failed to modulate EGCG-induced increase in contractility. However, the myocardial effects and intracellular calcium transients stimulated by EGCG were significantly reduced by the antagonist of the Na+/H+ exchanger (NHE) methyl-N-isobutyl amiloride (MIA), and by blocking of the reverse mode of the Na+/Ca2+ exchanger (NCX) by KB-R7943. CONCLUSION: These results indicate that Ca2+-dependent positive inotropic and lusitropic effects of EGCG are mediated in part via activation of the Na+/H+ exchanger and the reverse mode of the Na+/Ca2+ exchanger in the rat myocardium.     

Cognitive impairment after acute supratentorial stroke: a 6-month follow-up clinical and computed tomographic study

Summary To document the occurrence, time course, and predictors of global cognitive impairment following a supratentorial stroke, we prospectively studied 41 consecutive patients with acute cerebral ischemia and no evidence of pre-existing intellectual disturbances. The Graded Neurologic Scale and Mattis Dementia Rating Scale were used to assess neurologic and cognitive deficits within the first week, 3 weeks and 6 months after the onset of symptoms. CT was performed at each examination and semiquantitative measurements of infarct volumes and brain atrophy were obtained. Sixty-one percent of patients were found to be cognitively impaired within the first week. After 6 months this deficit had resolved in 24%, but was still present in 37% of individuals. Initial findings associated with a high risk of longterm intellectual dysfunction were: 1. moderately severe cognitive impairment, 2. diminished alertness in the acute stroke stage, 3. infarction involving the temporal lobe, 4. evidence of multiple brain infarcts and 5. pronounced ventricular enlargement. Logistic regression analysis revealed temporal infarcts and evidence of multiple ischemic lesions as the most powerful predictors of persistent cognitive impairment. By these two factors alone, 85.4% of study participants could be correctly classified regarding their cognitive outcome. These results suggest cognitive dysfunction to be a frequent sequela of supratentorial stroke. Its long-term persistence may be predicted on the basis of certain features.     

A single and multiple dose pharmacokinetic and metabolism study of meclofenamate sodium

A single and multiple oral dose administration study of meclofenamate sodium (Meclomen) was conducted in ten healthy male volunteers. An initial 300 mg oral dose on day 1 was followed by a 100 mg every 8 h dosage regimen on study days 4 through 18. Intensive plasma and urine sample collection was carried out over the first three study days, and for 120 h following administration of the final dose on day 18. Plasma and urine specimens were analyzed by a specific HPLC assay for unconjugated meclofenamic acid and metabolites I and II of meclofenamic acid before and after sample incubation with beta-glucuronidase. Meclofenamic acid was rapidly absorbed following oral dose administration. Concentrations of meclofenamic acid existed primarily as unconjugated drug in plasma, with only a small amount present in the conjugated form. Meclofenamic acid was rapidly eliminated, with an elimination half-life of approximately 1.3 h. This resulted in no detectable accumulation upon multiple dose administration. Metabolite I, which is one-fifth as active as meclofenamic acid in in vitro inhibition of cyclooxygenase, was present in unconjugated form at steady state in concentrations approximately 50 per cent of those of meclofenamic acid, as unconjugated drug. The majority of metabolite I in plasma existed as glucuronide conjugate. Metabolite II, which is inactive, was present in very significant concentrations in unconjugated form. Plasma protein binding determinations conducted on meclofenamic acid and metabolite I indicated that the free fraction of metabolite I was 8.7 to 10.9 times higher than that of meclofenamic acid. When the lower activity and lower steady state concentrations, but higher free fraction, are considered, it would appear that metabolite I may contribute significantly to the in vivo inhibition of cyclooxygenase activity seen after administration of meclofenamic acid.     

Effect of π-π charge-transfer complexation on distribution of some aromatics between water and 2,2,4-trimethylpentane

π-π charge-transfer complexation between an electron acceptor (tetracyanoethylene) and some aromatic electron donors has been found to significantly increase the distribution of tetracyanoethylene between pH 7 phosphate buffer and 2,2,4-trimethylpentane. Agreement between values derived using a theoretical model and experimental values, indicates that for the systems studied the apparent liquid-liquid distribution coefficient of a species is related directly to its charge-transfer complexation constant (with a second complexing species) and the concentration of this second species.     

Altitudinal hemianopia caused by occipital infarctions. Clinical and computerized tomographic correlations

Two patients with altitudinal homonymous hemianopia caused by bilateral occipital infarctions were studied. Their clinical-computerized tomographic correlations showed the anatomic representation of the superior and inferior visual fields in the lower and upper banks of the calcarine fissure, respectively. The patient with the superior-field defect was unusual because he retained normal color vision and facial recognition abilities, despite having bilateral lesions that have classically produced central achromatopsia and prosopagnosia.     

Thermodynamics and extrathermodynamics of organic solute liquid-liquid distribution between water and 2,2,4-trimethylpentane

The temperature dependencies of the distribution of substituted benzenes and methylbenzoates between aqueous phosphate buffer (pH 7.0) and 2,2,4-trimethylpentane have been determined using a rapid mix/filter probe system which enables short equilibration and measurement times to be achieved. Except for nitrosubstituted compounds, distribution increases with temperature. A single unique relationship between distribution coefficients and enthalpies of distribution could be described which indicates true linear enthalpy-entropy compensation, the origin of which is suggested as being almost entirely due to the properties of water. Examination of the theory implicit in the use of van 't Hoff operators, indicates that it is inappropriate to obtain thermodynamic quantities from a study of the temperature dependency of distribution when the solvent pair studied have: (i) high mutual solubility; and (ii) various intermolecular and molecular states which are temperature sensitive. The water/octan-l-ol system is exemplified as suffering from these limitations and linear enthalpy-entropy compensation previously reported for this system is shown to be due to probable statistical and experimental effects.