Respiratory changes of the P loop in the Frank vectorcardiogram

(1) Frank vectorcardiographic P loops of 25 healthy males were recorded at deep inspiration and expiration by using a minicomputer system with an averaging technique. Respiratory changes in 21 P parameters were quantitatively investigated. (2) The maximal left component of the P loop, the magnitude of the horizontal maximal vector and the magnitude of the P polar vector significantly decreased at deep inspiration as compared with those at expiration. The frontal and the spatial maximal vectors were significantly deviated vertically at deep inspiration as compared to those at expiration. (3) It was considered to be better to obtain P loops at a particular phase of respiration or to use those obtained by an averaging technique in order to analyse P loop in detail in various heart diseases, especially in the exercise stress test associated with rapid deep respiration. (4) The mechanism of respiratory P loop changes was discussed.

Diagnostic value of body surface map in myocardial infarction: assessment of location, size and ejection fraction as compared with coronary cineangiography and 201Tl myocardial scintigraphy

The diagnosis of the location and size of old myocardial infarction was made by the map and various indices obtained from the map were correlated with coronary arteriography, left ventriculography, and 201Tl myocardial scintigraphy. Diseased coronary arteries were presumed from Q30, Q40 area and/or peak voltage map and left ventricular wall motion was estimated from subtraction map. There were significant correlations between ejection fraction and sigma R in anterolateral MI (r = 0.51, p less than 0.001) and between ejection fraction and nQ30 in anterolateral (r = -0.47, p less than 0.001) and inferoposterior (r = -0.63, p less than 0.01) MI. Negative correlation was observed between myocardial uptake ratio (MUR) and nQ30 (r = -0.69, p less than 0.001) and positive correlation between MUR and sigma R (r = 0.50 p less than 0.01) in anterolateral MI. Those cases which could not be diagnosed by either ECG or 201Tl scintigraphy were correctly diagnosed by the map and it proved to have an excellent diagnostic accuracy for myocardial infarction.

The determination of molecular weights of Streptomyces subtilisin inhibitor and the complex of Streptomyces subtilisin inhibitor and subtilisin BPN' by sedimentation equilibrium

The molecular weight of Streptomyces subtilisin inhibitor (SSI), a protein proteinase inhibitor, and that of the complex of SSI and subtilisin BPN' [EC 3.4.21.14] were determined by a sedimentation equilibrium method in 25 mM phosphate buffer, at pH 7.0, ionic strength 0.1 M (NaCl), 25.0 degrees C. The molecular weight of SSI was found to be 23,000 over a wide concentration range, 0.01-10 mg/ml, the range used for inhibitory, spectrophotometric, and kinetic measurements. Based on the amino acid sequence, the molecular weight of SSI has been calculated to be 11,500 (Ikenaka, T., et al. (1974) J. Biochem. 76, 1191-1209); therefore, the molecular weight of 23,000 obtained above suggests that SSI is in a dimeric form under usual conditions in the concentration range of 5 X 10(-7)-5 X 10(-4) M. The molecular weight of the subtilisin BPN'-SSI complex was determined to be 78,000 in the concentration range of 0.03-5.0 mg/ml by sedimentation equilibrium of the crystallized preparation and by that of a mixture of subtilisin BPN' and SSI treated as a multicomponent-polydisperse system. The molecular weight obtained here, combined with the results of binding stoichiometry (Inouye, K., et al. (1977) J. Biochem. 82, 961-967) that showed that one mol of SSI (molecular weight, 11,500) and one mol of the enzyme (molecular weight, 27,500) are tightly bound (Kd less than 1 nM), demonstrate that one mol of dimeric SSI binds two mol of the enzyme to form a stable complex, E2I2.

Determination of Functionality Distributions in Telechelic Prepolymers by Thin-Layer Chromatography

Functionality distributions of telechelic prepolymers have been determined by thin layer chromatography (TLC). Commercially available 1,2-polybutadienes having either carboxyl or hydroxyl groups were examined. TLC with p-xylene as the developer made it possible to separate the sample into a nonfunctional component and a mixture of mono- and difunctional components. Complete separation of the sample into the three components was achieved by selecting the developer and development procedure appropriately. Quantification of the chromatograms was performed successfully in a TLC apparatus equipped with a flame ionisation detector. A simple method for the determination of the functionality distribution was proposed.