Phenylthiazolones (PTAs) of arginine and its homologs and analogs, homoarginine, norarginine (alpha-amino-gamma-guanidinobutyric acid), canavanine, and gamma-hydroxyarginine, were prepared. A steady-state kinetic analysis of the trypsin [EC 3.4.21.4]-catalyzed hydrolysis reactions was carried out and the kinetic parameters for these internal thioesters were compared with those for normal linear ester substrates. PTA-gamma-hydroxyarginine was so labile that hydrolysis by the enzyme could not be followed. PTA-arginine has a specificity constant (Kcat/Km) comparable to that for the Nalpha-unblocked arginine ester substrate, though the value is about 0.1% of that for a specific ester substrate, Nalpha-tosylarginine methyl ester. PTA derivatives of canavanine and homoarginine were hydrolyzed with Kcat/Km walues of the same order of magnitude as that for PTA-arginine. However, PTA-noraginine was much less susceptible to tryptic hydrolysis that PTA-homoarginine, while the linear esters of norarginine are known to be more susceptible than those of homoarginine.

Arginine↗

PubMed1978

Properties of the erythrocyte receptors for influenza C virus.

Properties of the receptor for influenza C virus were studied. Although the receptor for influenza C virus on chicken erythrocytes was destroyed by the homologous virion, neuraminidase activity could not be detected in any of the influenza C virus strains tested. The receptor activity of chicken erythrocytes for influenza C virus was diminished by formaldehyde treatment but not by periodate oxidation. There was a considerable variation in the pattern and the titer of hemagglutination of influenza C virus when human erythrocytes of different blood types were used; the virus agglutinated most type B erythrocytes but not type A erythrocytes. By using human type B erythrocytes, differences among strains of influenza C virus in the hemagglutinating activity were also demonstrated. These results showed that both the receptor for and the receptor-destroying activity of influenza C virus were completely different from those of influenza A or B virus and also that carbohydrates were not involved in the receptor for influenza C virus.

ABO Blood-Group System↗

PubMedDate not supplied

Carcinomas involving the esophagogastric junction.

In order to avoid confusion in categorizing malignant lesions for surgical treatment, a definition and criteria of carcinomas significantly involving the esophagogastric junction (ECJ-Ca) and those of gastric cardia less significantly involving the esophagogastric junction (eC-Ca) are proposed, devised as this study was from a practical viewpoint. A comparative analysis of carcinomas of these groups was carried out, the control group being those carcinomas situated mainly in the upper third segment of the stomach but not involving the esophagogastric junction (C-Ca). Carcinomas of these regions can be determined by the EGJ-Index (EGJ-I) calculated through the following formula: EGJ-Index = [( Length of the esophageal portion of the lesions)/(length of the of the esophageal portion + gastric portion of the lesion])x1,000. Thus lesions of these regions are easily and practically classified as follows: [I]: EGJ-Ca 250 less than or equal to EGJ-I less than or equal to 750, 59 cases; ( II]: eC-Ca 0 less than or equal to EGJ-I less than 250, 88 cases; [III]: C-Ca 0 = EGJ-I, 208 cases. We found these categories quite suitable for practical use.

Carcinoma↗