No abstract

No abstract

Heat-induced gelling characteristics of myosin-actin from cardiac and skeletal muscle were investigated under various conditions in a model system. The interaction between actin and myosin at weight ratios of 1 : 15~1 : 9 from cardiac or skeletal muscle seemed to contribute to heat-induced gel strength at pH 6.0, but such interaction seemed to carry little significance in gel formation at pH 5.4.A decrease in gel rigidity of chemically modified myosin (PCMB-treated) and actomyosin (TNBS-treated actin and PCMB-treated myosin) suggested that certain thiol (SH) group ofcysteine residues in myosinand s-NH2groups of lysine residues in actin were involved in the development of gel on heating. However, the magnitude of difference in gel strength at pH 6.0 (< 1,000dyn/cm2) and at pH 5.4 (9,000dyn/cm2) of SH-blocked myosin was indicative of the major contribution of electrostatic interactions in the gelation of myosin. The effects of ATPon the gelation of myosin and actomyosin were also pH dependent. Total rod and LMMsub fragments of cardiac myosin formed respectively 2.6 times and 2-times stronger gel than produced by HMMsub fragments at identical conditions in the model system, but S-l sub fragment formed extremely weak gels under those conditions, which suggested the importance of the "tail" segment of the myosin molecule in the heat-induced gelation process.Amonganimal proteins, the gelling of col-lagen^and skeletal muscle actomyosin2~4) have been studied intensively in theory and practice. While collagen can form thermally reversible gels in a wide pH range and has no specific ionic requirement,5} myosin and actomyosin form irreversible gels on heating to a certain temperature and require specific pH and ionic conditions.6'7) Even the myosin from different types of skeletal muscle appears to vary in its requirements for forming gels of appreciable strength.8) However, information was altogether lacking on the heat-induced 63 gel formability of cardiac myosin and actomyosin complex.Our preceding paper9) provides information on the influence of pH, temperature, actin, and ionic and protein concentration on the heatinduced gel formation of cardiac myosin. This series describes the effects of ATP, SH-groups of myosin, and £-NH2 groups of actin on the gelling potential of cardiac myosin and actomyosih complexes. Wealso a compared the gel strength of myosin and reconstituted actomyosin from cardiac and skeletal muscle under various conditions in a model system.

No abstract

To develop the checking system for prescription of injections by pharmacists,a questionnaire of intravenous admixture on nurses of 7 hospitals in Yamaguchi Prefecture was carried out.It became clear that nurses had many problems in the ward which is not clean.It seems dengerous for the nurses to mix many injections,because they must perform with various other works.The nurses strongly expected pharmacists admix injections.The information such as easily incompatible injections,adverse reaction for injections when those are administered, has been required.