Further investigation on the role of selenium deficiency in the aetiology and pathogenesis of Keshan disease.

Selenium supplements were not able to restore the ultrastructural changes in the myocardium of latent Keshan disease patients taken by using cardiac catheter endomyocardial biopsy. Observations on the changes of selenium status and the incidence of Keshan disease showed that new latent and naturally-occurring chronic cases were found in the endemic area even after selenium levels had been elevated in the residents to the levels typical in the non-endemic area. These results indicate that although selenium deficiency might be a primary pathogenetic geogen in the occurrence of Keshan disease, it is rather a conditional predisposing factor than a specific or initiative aetiologic factor for the occurrence of Keshan disease. Selenium supplementation could apparently alleviate the higher platelet responsiveness of residents in the endemic area, which might contribute to eliminating the basis for the occurrence of the multifocal perivascular necroses in myocardium of acute and subacute Keshan disease.

The synthesis of protective fragments of alpha-human atrial natriuretic polypeptide (alpha-hANP).

In this paper the synthesis of alpha-human atrial natriuretic polypeptide fragments (positions, 1-4, 5-10, 11-16, 17-22, 23-28) by solution method is reported. In the synthesis of some peptides, the results from mixed anhydride procedure and active ester procedure are compared. In the synthesis of other peptides, the effects of reaction temperature, basicity of catalyst, and reaction time on the specific rotations and yields of these compounds are observed. The sequence of amino acids of all the protective polypeptides is confirmed by FAB-MS.