Vectorcardiograms in aortic and mitral regurgitation -- a comparative study

Thirteen patients with aortic regurgitation (AR) and 13 with mitral regurgitation (MR) were compared quantitatively from the standpoint of their vector-cardiograms (VCG). Vectorcardiographic parameters were also compared with left ventricular angiographic parameters. The QR time interval was longer and the magnitude of the spatial maximum QRS vector was larger in the AR group, but these differences were thought to be attributed to the differences in length of the left ventricular long axis and the left ventricular end diastolic volume (LVEDV). In the AR group, the ratio of the width to the long axis of the QRS loop in the horizontal plane correlated well with the length of the left ventricular long axis and the angle made by the axis from the middle of the aortic valve to the left ventricular apex and the horizontal axis in the lateral view of the angiogram. In the MR group, these correlations were poor.

Studies on transfer ribonucleic acids and related compounds. 8(1). Further studies on aromatic phosphoramidates as a protecting group for phosphomonoesters

Stability of aromatic phosphoramidates was studied using 2',3'-O-dibenzoyluridine 5'-phosphoramidates and N,2',3'-O-tribenzoylcytidine 5'-phosphate. The effect of dicyclohexylcarbodiimide in this mixture was investigated. Decomposition of the anilidate was slower in the presence of DCC. Substituted anilidates of uridine 5'-phosphate were synthesized and the stability of these amidates in anhydrous pyridine was studied.2'-O-Benzoyluridine 3'-phosphoranilidate and the corresponding beta-naphthylidate were compared in their stabilities in anhydrous pyridine, 50% aqueous pyridine and 80% acetic acid. 2'-O-Benzoyluridine 3'-phosphoro-beta-naphthylidate was used for synthesis of dinucleotides.