RESUMEN
Plasma renin activity, angiotensin Ⅱ, Aldosterone and cortisol in 380 healthy subjects were measured by radioim-munoassay at 10, 3700 and 4300 metres above sea level. The results showed as follows: Firstly, no significant difference was noted between Tibetan and Han residents at high altitudes with reference to these four parameters. Secondly, the renin-angiotensin-aldosterone system and adrenocortical function in residents at high altitude revealed hypofunction. Thirdly, the responsiveness of aldosterone to renin declined gradually with increasing altitude, and slope declined as well. These changes might be considered as a chronic adaptive mechanism in residents at high altitude to hyposic environment.It may be suggested that appropriate use of adrenocorticosteroids may be of some clinical value in the prevention and treatment of some altitude-induced diseases.
RESUMEN
A method for on-line real-time estimation of myocardial contractility parameters at the isovolumetric period of the left ventricular pressure wave form using Maxwell mode of cardiac muscle is described. After simplifing the mathematical mode., we presented a new technique to calculate the Vmax using 1/Vce versus p linear regression, A measuring system based on IBM-PC/XT microcomputer was developed as well. The system is employed in physiological experiments for evaluation of myocardial contractility under control condi- tions, as well as after drug administration.
RESUMEN
Various chemical and gas-liquid chromatographic analyses indicate that the lipid A backbone of the lipopolysaccharide (LPS) isolated from Bacteriodes fragilis NCTC 9343 is chemically constituted by a ?1, 6-interlinked D-gluco-samine disaccharide. It is phosphorylated at its 1-position by a glycosidic-linkage while the ester-bound phosphate present generally in other lipid A is depleted. The lipid A is lower fatty acylated in the amount of 5.2 fatty acids per lipid A molecule (of which 0.73 forms 3-acyloxyacyl groups). The LPS containing such a lipid A component has been shown endowing with a weaker endotoxicity.