Acta Medica Okayama 41巻 5号

Thirty-eight patients were operated on for mitral stenosis between March 1979 and September 1981. Thirty-six of them were examined as to their age, symptom duration, chest roentgenograms, electrocardiograms and echocardiograms to obtain various indices of left ventricular function. The usefulness of these indices as preoperative risk factors for predicting postoperative low cardiac output syndrome (LOS) was investigated. Cases which had values of ejection fraction, cardiac index, percent fiber shortening or mean velocity of circumferential fiber shortening less than 0.45, 2.0 l/min/m2, 25% and 0.80 circ/sec, respectively, in the preoperative echocardiographic examination were associated with a greater chance of postoperative LOS. Each of these factors was independently useful as a risk factor in cardiac surgery for mitral stenosis. Moreover, it was revealed that the combination of a preoperative percent fractional shortening (%FS) of less than 30% and a cardiac index smaller than 2.0 l/min/m2 indicated a strong predisposition toward postoperative LOS.

A rapid method was devised for the detection of virus particles in wart specimens. The upper layer of warts was cut perpendicularly to the surface, and the freshly cut surface was lightly touched to an electron microscope grid. The grid was then stained with a small drop of phosphotungstate and observed electron microscopically. On the specimen grid thus prepared, papillomavirus particles were easily discriminated from tissue debris. Papillomavirus particles were detected in 71% of verrucae plantares, 78% of verrucae palmares, 50% of verrucae vulgares and 75% of condylomata acuminata by the present method.

Protection of Escherichia coli NIHJ and C57BL mice from the effects of 60Co gamma-rays provided by S-alk(en)yl-L-cysteines and their hydantoin derivatives was examined. E. coli (10(6) cells/ml) suspended in a 20 mM aqueous solution of one of the drugs was irradiated with 60 Gy of gamma-rays. Five week-old male mice were exposed to 5.0-9.5 Gy of gamma-rays after a single intraperitoneal injection of 0.75 mmol/kg body weight of each compound. In both E. coli and mice, S-allyl compounds afforded more effective radioprotection than S-propyl compounds. The replacement of the alpha-hydrogen of S-substituted cysteines by methyl groups decreased the radioprotective effect. Hydantoin derivatives were much more radioprotective than the original sulfur-containing amino acids. Especially, DL-5-allylthiomethyl-5-methylhydantoin had a remarkable radioprotective effect in mice. The gamma-radiolysis mechanism of thiomethylhydantoin derivatives was discussed in connection with the radioprotective effect of the drugs.

Antibody-dependent macrophage-mediated cytotoxicity was studied to determine the significance of cytophilic anti-thyroglobulin antibody (ATgA) present in the sera of patients with Hashimoto's thyroiditis. Effector cells were normal human monocytes or guinea-pig peritoneal exudate cells, and target cells were human thyroglobulin(Tg)-coated chicken erythrocytes. Cytotoxicity was evaluated by morphological observation and by 51Cr-releasing assay. Normal human monocytes rapidly destroyed ATgA-bound Tg-coated chicken erythrocytes by extracellular cytolysis and by phagocytosis. On the contrary, human monocytes "armed" with cytophilic ATgA destroyed Tg-coated chicken erythrocytes slowly and to a lesser extent, and only by extracellular cytolysis. When normal monocytes or peritoneal exudate cells were incubated with Tg-coated chicken erythrocytes in the presence of the sera of patients with Hashimoto's thyroiditis, phagocytosis occurred rapidly, but extracellular cytolysis developed rather slowly. These data suggest the possibility that human monocytes participate in antibody-dependent cell-mediated cytotoxicity (ADCC) in vivo, which may be an important destructive mechanism in Hashimoto's thyroiditis. It is also possible that ATgA cytophilic for monocytes render non-immune peripheral monocytes cytotoxic against Tg-bearing cells.

To investigate factors involved in excision repair DNA synthesis, a soluble extract was prepared from permeable mouse sarcoma (SR-C3H/He) cells by homogenization and ultracentrifugation. DNA synthesis measured by using native calf thymus DNA as the template-primer and the extract as the polymerase source showed low activity. The DNA synthesis was enhanced more than ten-fold by the addition of an appropriate concentration of bleomycin, a radiomimetic DNA-damaging drug. Using selective inhibitors of DNA polymerases, it was shown that the DNA polymerase involved in the bleomycin-induced DNA synthesis was DNA polymerase beta. In addition to DNA polymerase beta, an exonuclease which converts bleomycin-damaged DNA into suitable template-primers for repair DNA synthesis appeared to be present in the permeable cell extract.

The difference in the physiological condition of drivers of manual transmission buses (MTB) and automatic transmission buses (ATB) was examined from the viewpoint of occupational health. This study was based on a self-administered questionnaire which involved items concerning subjective fatigue complaints. No differences in the mental fatigue and stress between MTB drivers and ATB drivers were observed. Although ATB drivers tended to feel less physical fatigue than MTB drivers, the difference was not statistically significant. From these results, it was suggested that there was little difference in the subjective fatigue between ATB drivers and MTB drivers.

The palmar metacarpal arteries in monkey hands were studied. The palmar metacarpal arteries arose from the deep palmar arch or catella palmaris proximalis and descended in the deep palm, forming the catella palmaris distalis at the distal end of the metacarpus. The palmar metacarpal arteries could be classified into four kinds in relation to the interosseous muscles and metacarpal bones: (i) the superficial palmar metacarpal (sM) arteries descending on the palmar surfaces of the interosseous muscles along the metacarpal bones, (ii) the superficial palmar intermetacarpal (sI) arteries descending on the palmar surfaces of the interosseous muscles along the intermetacarpal spaces, (iii) the deep palmar metacarpal (dM) arteries descending deep in the interosseous muscles along the metacarpal bones, and (iv) the deep palmar intermetacarpal (dI) arteries descending deep in the interosseous muscles along the intermetacarpal spaces. These findings largely coincide with those obtained from studies of the human hand by Murakami (1969).