Search PubMed⌕ Search

Biomedical subjects

T Masaki

Publications and source records attributed to T Masaki.

At least 523 records · Page 29Linked to original sources
PubMed1983

[Effect of cefotaxime in the treatment of infections associated with hematologic diseases].

Twenty patients suffering from severe infections (9 with respiratory tract infection, 9 with urinary tract infection, 2 with pharyngitis, 1 with enteritis and 4 with fever of unknown origin (FUO] were treated by intravenous infusing CTX 2 g over 30 to 40 minutes 2 or 3 times daily for 4 to 10 days. Other antibiotics were concomitantly used in 9 cases. Response to CTX was proved good in 15 cases (75%), fair in 3 cases and poor in 2 cases. No adverse reactions were observed.

Adolescent↗
PubMed1982

Isoforms of C-protein in adult chicken skeletal muscle: detection with monoclonal antibodies.

Monoclonal antibodies (McAbs) specific for the C-proteins of chicken pectoralis major and anterior latissimus dorsi (ALD) muscles have been produced and characterized. Antibody specificity was demonstrated by solid phase radioimmunoassay (RIA), immunoblots, and immunofluorescence cytochemistry. Both McAbs MF-1 (or MF-21) and ALD-66 bound to myofibrillar proteins of approximately 150,000 daltons; the former antibody reacted with pectoralis but not ALD myofibrils, whereas the latter recognized ALD but not pectoralis myofibrils. Chromatographic elution of the antigens from DEAE-Sephadex, and their distribution in the A-band, support the conclusion that both of these antibodies recognize variant isoforms of C-protein. Since both McAbs react with a protein of similar molecular weight in the A-band of all myofibrils of the posterior latissimus dorsi (PLD) muscle, we suggest that either another isoform of C-protein exists in the PLD muscle or both pectoralis and ALD-like isoforms coexist in the A-bands of PLD muscle.

Animals↗
PubMed1982

Immunochemical analysis of myosin heavy chain during avian myogenesis in vivo and in vitro.

Monoclonal antibodies (McAbs) against the myosin heavy chain (MHC) of adult chicken pectoralis muscle have been tested for reactivity with pectoralis myosin at selected stages of chick development in vivo and in vitro. Three such McAbs, MF 20 and MF 14, which bind to light meromyosin, and MF 30, which binds to myosin subfragment two (S2), were used to assay the appearance and accumulation of specific MHC epitopes with: (a) indirect, solid phase radioimmune assay (RIA), (b) immunoautoradiography, (c) immunofluorescence microscopy. McAb MF 20 bound strongly and equivalently to MHC at all stages of embryonic development in vivo. In contrast, the MF 30 epitope was barely detectable at 12 d of incubation but its concentration rose rapidly just before hatching. No detectable binding of MF 14 to pectoralis myosin could be measured during myogenesis in vivo until 1 wk after hatching. Immunofluorescence studies revealed that all three epitopes accumulate in the same myocytes of the developing pectoralis muscle. Since all three McAbs bound with high activity to native and denatured forms of myosin, it is unlikely that differential antibody reactivity can be explained by conformational changes in myosin during development in vivo. When myogenesis in vitro was monitored using the same McAbs, MF 20 bound to the MHC at all stages tested while reactivity of MF 30 and MF 14 with myosin from cultured muscle was never observed. Thus, this study demonstrates three different immunochemical states of the MHC during development in vivo of chick pectoralis muscle and the absence of later occurring immunochemical transitions in the MHC of cultured embryonic muscle.

Animals↗
PubMed1982

Changes in myosin isozymes during development of chicken breast muscle.

The patterns of myosin isozymes in embryonic and adult chicken pectoralis muscle were examined by electrophoresis in a non-denaturing gel system (pyrophosphate acrylamide gel electrophoresis), and both light chains and heavy chains of embryonic and adult myosin isozymes were compared. In pyrophosphate acrylamide gel electrophoresis, the predominant isozyme component in embryonic pectoralis myosin could be clearly distinguished from adult myosin isozymes. SDS-polyacrylamide gel electrophoresis indicated that the light chain composition of embryonic myosin was also different from that of adult myosin. The pattern of peptide fragments produced by myosin digestion with a-chymotrypsin differed significantly between embryonic and adult skeletal myosin. These results suggest that myosin in the embryonic pectoralis muscle is different in both light and heavy chain composition from myosin in the same adult tissue.

Animals↗
PubMed1982

Molecular properties and functions in vitro of chicken smooth-muscle alpha-actinin in comparison with those of striated-muscle alpha-actinins.

alpha-Actinin purified from chicken gizzard smooth muscle was characterized in comparison with alpha-actinins from chicken striated muscles, or fast-skeletal muscle, slow-skeletal muscle, and cardiac muscle. The gizzard alpha-actinin molecule consisted of two apparently identical subunits with a molecular weight of 100,000 on SDS-polyacrylamide gel electrophoresis, as do striated-muscle alpha-actinins. Its isoelectric points in the presence of urea were similar to the striated-muscle counterparts. Despite these similarities, distinctive amino acid sequences between smooth-muscle alpha-actinin and striated-muscle alpha-actinins were revealed by peptide mapping using limited proteolysis in SDS. Gizzard alpha-actinin was immunologically distinguished from striated-muscle alpha-actinins. Gizzard alpha-actinin formed bundles of gizzard F-actin as well as of skeletal-muscle F-actin, but could not form any cross-bridges between adjacent actin filaments under conditions where skeletal-muscle alpha-actinin could. Temperature-dependent competition between gizzard alpha-actinin and tropomyosin on binding to gizzard thin filaments was demonstrated by electron microscopic observations. Gizzard alpha-actinin promoted Mg2+-ATPase activity of reconstituted skeletal actomyosin, gizzard acto-skeletal myosin, and gizzard actomyosin. This promoting effect was depressed by the addition of gizzard tropomyosin. These findings imply that, despite structural differences between gizzard and striated-muscle alpha-actinin molecules, they function similarly in vitro, and that gizzard alpha-actinin can interact not only with smooth-muscle actin (gamma- and beta-actin) but also with skeletal-muscle actin (alpha-actin).

Actinin↗
PubMed1982

Reduction of experimentally produced acute myocardial infarction size by a new synthetic inhibitor, NCO-700, against calcium-activated neutral protease.

Calcium-activated neutral protease (CANP) might be involved in the irreversible degradation of myocardial proteins in the ischemic region, leading to the loss of contractility. The new compound, NCO-700, and its analogues were synthetized against CANP. Among these analogues, NCO-700 was the most potent to reduce the size of acute myocardial infarction, which was produced by coronary artery ligation in rabbits, in vivo, although it showed less powerful action to inhibit CANP activity in vitro. The new reagent, NCO-700 might be promising to reduce acute myocardial infarction size and beneficial for the clinical studies, because it had no action to reduce cardiac muscle contractility, compared with beta antagonist or calcium-channel blockades.

Animals↗
PubMed1982

[Combination chemotherapy with neocarzinostatin (NCS) and other antitumor agents for advanced carcinoma of the digestive organs--improved clinical effect with NFO therapy].

We have previously reported the clinical effect of NF therapy (NCS 5,000 units and 5-FU 500 mg intravenously; twice a week) on patients with advanced carcinoma of the digestive system. In the present study, NFO therapy (NCS 2,000 units and 5-FU 500 mg intravenously, Picibanil 1-2K. E. intramuscularly; twice a week) was applied for those patients to take advantage over NF modality. Treated were 62 patients with NFO and 48 were evaluated for its clinical effects. In comparison of NFO and NF, the antitumor effects were noted in 9 of 48 patients (18.8%) for NFO, and 2 of 27 (7.4%) for NF therapy judged by Koyama & Saito's criterion. If the Karnofsky's criterion was applied, I-A category or more were obtained in 10 of 48 patients (20.8%) for NFO and in 2 of 27 (7.4%) for NF therapy. In particular, NFO therapy resulted in the advantageous clinical effects on patients with hepatic and pancreatic carcinomas irrespective of primary or metastatic. The adverse effects of NFO were not more frequent than those of NF therapy. From these results, a new combination regimen, NFO, is thought to bring about a considerable benefit in the treatment of advanced carcinoma of the digestive organs.

Adult↗
PubMed1981

Studies on a new proteolytic enzyme from A chromobacter lyticus M497-1. I. Purification and some enzymatic properties.

Achromobacter lyticus M497-1 produces three kinds of alkaline proteases (protease I, II and III) in culture medium along with the bacteriolytic enzyme (Masaki, T., Nakamura, K., Isono, M. and Soejima, M. (1978) Agric. Biol. Chem. 42, 1443--1445). Among these three proteases, Achromobacter protease I (EC 3.4.21.-) shows strict splitting for lysine residues at the carboxyl side of the splitting point. This enzyme was purified through a sequence of benzalkonium chloride treatment, acetone fractionation, CM-cellulose and DEAE-cellulose treatment chromatography on AH-Sepharose 4B and isoelectric focusing method. This form was shown to be homogeneous by polyacrylamide gel electrophoresis and ultracentrifugation analysis. The physicochemical properties of the enzyme were: Mr 30 500; partial specific volume (v), 0.717 ml/g; intrinsic viscosity (nu), 0.0385) dl/g; isoelectric point (pI) 6.9; and E1%1cm at 280 nm, 18.77. The enzyme was composed of 294 residues of amino acid per molecule, with glycine as NH2-terminal and lysine as COOH-terminal amino acids. The optimum pH values with casein, Bz-lys-pNA and Tos-Lys-OMe were 8.5--10.7, 9.0--9.5 and 7.8--8.2, respectively. The enzyme was inhibited by iPr2P-F, PhCH2SO2F and Tos-LysCH2Cl but not by Tos-ArgCH2Cl, EDTA, o-phenanthroline and PCMB.

Amino Acids↗
PubMed1981

Studies on a new proteolytic enzyme from Achromobacter lyticus M497-1. II. specificity and inhibition studies of Achromobacter protease I.

The unique specificity of Achromobacter protease I for lysine residue was investigated using synthetic and natural substrates, i.e., lysine derivatives, arginine derivatives, lysine vasopressin, substance P, ACTH and insulin. The enzyme cleaved only the -Lys-X- bonds in the above substrates. The binding affinity of alkylamines as determined by Ki was much stronger than that of the corresponding alkylguanidines.

Adrenocorticotropic Hormone↗
PubMed1981

Eu-actinin, a new structural protein of the Z-line of striated muscles.

A new protein component of the Z-line of striated muscles was isolated from chicken breast muscle. This protein has been designated as eu-actinin because of its close similarity in polypeptide molecular weight to actin. Eu-actinin was extracted from myosin-removed myofibrils at low ionic strength at pH 6.5 and purified by column chromatography on Sepharose 4B and DEAE-cellulose. Although the polypeptide molecular weight of eu-actinin measured by SDS-polyacrylamide gel electrophoresis is similar to that of actin, other physico-chemical properties of eu-actinin definitely differ from those of actin. The isoelectric point of eu-actinin was more acidic than that of actin. The amino acid composition of eu-actinin was found to be different from that of actin or those of other muscle structural proteins. The results of analytical gel filtration on Sepharose 4B indicated that eu-actinin forms dimers through non-covalent bonding under aqueous conditions. Eu-actinin has a low axial asymmetry under low-salt conditions, as judged from its intrinsic viscosity ([eta] = 6.4 ml/g for the dimer state) and exhibits a tendency to undergo self-association with increasing ionic strength. Interactions of eu-actinin with other muscle proteins were examined by the affinity column technique. It was shown that eu-actinin binds to actin and alpha-actinin. Eu-actinin exhibited strong seeding ability for the polymerization of actin. Antibody to eu-actinin was raised in a goat and purified by affinity chromatography. The specific antibody against eu-actinin did not form precipitine lines with actin or alpha-actinin. Immunofluorescence studies revealed that eu-actinin is localized at the Z-line of myofibrils. The FITC-conjugated antibody to eu-actinin also stained the Z-lines of rabbit skeletal muscle and chicken cardiac muscle. Therefore, it was concluded that eu-actinin is a new, ubiquitous constituent of Z-lines of striated muscles.

Actinin↗
PubMed1981

Increase in protein synthetic activity in chicken muscular dystrophy.

An increased level of protein synthesis was observed in an in vitro translation when the polyribosomes and postmicrosomal supernatant were prepared from dystrophic rather than normal muscle. This increment in protein synthetic activity was observed even in young dystrophic muscle in which no clinical and morphological abnormalities were detected. No specific increase in the rate of synthesis of any protein could be demonstrated in dystrophic muscle relative to normal muscle. Since a possible reason for the increment in protein synthetic activity was an increase in the activity of factor(s) in the postmicrosomal fraction, several of these were prepared from normal and dystrophic breast muscles and their activities were compared. Crude elongation factor (EF) from dystrophic muscle activated poly(U) directed polyphenylalanine synthesis more than the normal EF. This increase was shown to be due to higher levels of EF1 and EF2 in dystrophic than in normal muscle and not to a decrease in protease of RNase activity in the supernatant of dystrophic muscle relative to normal muscle. A comparison of the abilities of the postmicrosomal supernatants of normal and dystrophic muscle was made to support protein synthesis in vitro as a function of development age. The activity of aminoacyl-tRNA synthetase was also higher in the dystrophic supernatant than in the normal supernatant.

Amino Acyl-tRNA Synthetases↗