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Biomedical subjects

A Ito

Publications and source records attributed to A Ito.

At least 721 records · Page 40Linked to original sources

[A case report of primary liver cancer with cerebral metastasis after hepatic resection].

A 67-year-old male, who had a left hepatectomy for hepatocellular carcinoma, was readmitted to our hospital because of a left hemiparesis. A brain computed tomography scan and an r-carotid angiogram revealed a large mass involving the right parietal area, and thus a brain tumor removal was performed. A histological diagnosis of the removed brain tumor found it to be a metastatic, hepatocellular carcinoma. The patient died of pulmonary congestion due to lung metastasis, approximately 2 years and seven months after hepatectomy, and 1 year and three months after the removal of this metastatic brain tumor. In selected cases, the removal of a metastatic brain tumor seems to bring about improvements in the quality and duration of life.

Aged↗

Procollagenase activator produced by rabbit uterine cervical fibroblasts.

Culture medium from rabbit uterine cervical fibroblasts contained a procollagenase and a neutral proproteinase which acts as a procollagenase activator. These two proenzymes have been purified by a combination of ion-exchange, affinity and gel chromatographies. The purified neutral proproteinase showed Mr 60,000 with sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. This neutral proproteinase was activated by trypsin, 4-aminophenylmercuric acetate (APMA) and plasmin, and the active species of the proteinase had Mr 53,000 when activated by APMA; kallikrein and urokinase did not activate this proproteinase. The purified neutral proteinase was inhibited by EDTA, 1,10-phenanthroline and rabbit plasma, but not by serine proteinase inhibitors, suggesting that this proteinase is a metal-dependent proteinase. The purified enzyme could also degrade gelatin, casein, proteoglycan and type IV procollagen. The purified procollagenase had Mr 55,000 and was activated by trypsin, APMA and the active neutral proteinase. These activations were accompanied by decrease in Mr, and the activated species had an Mr which was approx. 10,000 less than that of the procollagenase. In particular, procollagenase activation with neutral proteinase depended on incubation time and proteolytic activity of proteinase. These results indicate that activation of procollagenase by the rabbit uterine neutral proteinase is related to limited proteolysis in the procollagenase molecule.

Animals↗

Collagenase-like (CL) peptidase activity in synovial fluid from patients with rheumatoid arthritis.

We found the presence of collagenase-like (CL) peptidase in synovial fluid by a highly sensitive fluorescence assay using (succinyl-Gly-Pro-Leu-Gly-Pro)-4-methyl-coumaryl-7-amide (Suc-GPLGP-MCA) as a substrate. Suc-GPLGP-MCA is hydrolyzed at the Leu-Gly bond by CL-peptidase. The CL-peptidase activity in synovial fluid was significantly higher in patients with rheumatoid arthritis (RA) than in patients with osteoarthritis (OA) and in arthropathy-free controls. No significant difference in CL-peptidase activity in synovial fluid was found between patients with OA and arthropathy-free controls.

Arthritis, Rheumatoid↗

Synthesis of heterogeneous mRNA-like RNA and low-molecular-weight RNA before the midblastula transition in embryos of Xenopus laevis.

It has been proposed and is now widely accepted that in Xenopus laevis embryogenesis RNA synthesis starts only at and after 12 rounds of cleavage, at the time of the midblastula transition (MBT). In this report, however, we provide evidence that RNA synthesis takes place prior to the MBT stage in normally developing Xenopus embryos. In the present experiments, we cultured fertilized eggs in 80 mM phosphate buffer and loosened the adhesion between blastomeres, so that [3H]uridine could be incorporated into blastomeres from the surrounding medium. By this method and also by microinjection of [3H]GTP, we found that embryos synthesize heterogeneous, nonribosomal, high-molecular-weight RNAs and a relatively small amount of low-molecular-weight RNA as early as the sixth cleavage. RNAs synthesized were not of mitochondrial origin, and the synthesis was sensitive to actinomycin D and alpha-amanitin. From these results we conclude that mRNA-like RNA and low-molecular-weight RNA start to be synthesized during the cleavage stage.

Amanitins↗