Electrocardiographic abnormalities in aluminium phosphide poisoning with special reference to its incidence, pathogenesis, mortality and histopathology

Ninety-five patients out of total 190 cases of aluminium phosphide (ALP) poisoning, who exhibited ECG changes were studied for incidence, type and pattern of ECG abnormalities, their effect on mortality and their relationship with histopathology of heart. Its incidence in the present study was 50%. The arrhythmias, conduction disturbances and ischaemic pattern occurred more or less in equal frequency. Certain ECG abnormalities which had not been reported previously ie, early repolarisation syndrome, varied sino-atrial blocks, bradycardia-tachycardia syndrome and electrical alternans were observed in this study. The clinical profile of these cases was similar irrespective of whether patients had ECG abnormalities or not. Shock was the cardinal feature. There was no effect of ECG abnormalities on mortality. The mortality which was otherwise high, depended upon severity of poisoning, dose of poison consumed, duration of shock, failure of response of shock to resuscitative measures and severe hypomagnesaemia. The pathogenesis of ECG abnormalities is still obscure. Hypomagnesaemia was observed in all the 18 cases studied, irrespective of ECG abnormalities. However, these were common when hypomagnesaemia was severe. Hypoxaemia and shock were not the contributory factors for these abnormalities. Autopsy revealed stereotyped histopathological changes of toxic myocarditis independent of ECG findings.     

Reversal of startle gating deficits in transgenic mice overexpressing corticotropin-releasing factor by antipsychotic drugs.

Chronically elevated levels of corticotropin-releasing factor (CRF) in transgenic mice overexpressing CRF in the brain (CRF-OE) appear to be associated with alterations commonly associated with major depressive disorder, as well as with sensorimotor gating deficits commonly associated with schizophrenia. In the present study, we tested the hypothesis that antipsychotics may be effective in normalizing prepulse inhibition (PPI) of acoustic startle in CRF-OE mice, which display impaired sensorimotor gating compared to wild-type (WT) mice. The typical antipsychotic haloperidol and atypical antipsychotic risperidone improved PPI in the CRF-OE mice, but were ineffective in WT mice. The atypical antipsychotic clozapine did not influence PPI in CRF-OE mice, but reduced gating in WT mice. This effect of clozapine in the CRF-OE mice may thus be regarded as a relative improvement, consistent with the observed effect of haloperidol and risperidone. As expected, the anxiolytic, nonantipsychotic chlordiazepoxide was devoid of any effect. All four compounds dose-dependently reduced the acoustic startle response irrespective of genotype. These results indicate that antipsychotic drugs are effective in improving startle gating deficits in the CRF-OE mice. Hence, the CRF-OE mouse model may represent an animal model for certain aspects of psychotic depression, and could be a valuable tool for research addressing the impact of chronically elevated levels of CRF on information processing.     

Block copolymers with bipyridine containing segments: Synthesis and self-organization by Cu(I) complexation

The synthesis and properties of segmented ABA triblock and (AB)_n multiblock copolymer systems with 6,6′-disubstituted 2,2′-bipyridine (bpy) building blocks B and poly(oxytetramethylene) soft segments A are described. The access to the disubstituted bipyridines in large scale quantities was achieved by modification of conventional synthetic routes. In the presence of copper(I) ions these polymers formed mononuclear [Cu(I)(bpy)₂] complexes in solution through self-assembly. The complexed copolymers were microphase separated systems in bulk with nano to mesoscopic superstructures consisting of copper-bpy complex aggregates in a polyether matrix. The thermal, mechanical and elastomer properties of the block copolymers varied with composition.