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Biomedical subjects

N Tamura

Publications and source records attributed to N Tamura.

At least 343 records · Page 19Linked to original sources

Pneumatosis cystoides intestinalis: Report of 3 cases with special reference to its non-surgical treatment.

Three patients with pneumatosis cystoides intestinalis had been reported. All patients are females with lesions in the left and sigmoid colon, grouped as idiopathic etiology. Two patients are in middle age, workers in the manufacturing plant for electric apparatus. One patient received surgical resection of the affected segment. After oral antibiotics treatment, one patient was resected only the intensely affected segment, so that many cysts were still remained, but they disappeared after 3 weeks. One patient was treated with lactobacillus preparations and lactulose. Her subjective symptoms and fecal occult blood disappeared, and X-ray studies and endoscopic examination revealed an almost complete recovery.

Adult↗

Binding of activated properdin to untreated erythrocytes: a new function of activated properdin.

Activated human properdin was found to be capable of binding to rabbit and sheep erythrocytes to form new intermediate cells of the alternative pathway of the complement system. The intermediate cells, termed EP, can react with B, D and C3 to form other intermediate cells, tentatively termed EPB(D)C3, which can be lysed by the subsequent action of six late-acting complement components, C3 to C9. The possibility of participation of C3, B, D or immunoglobulin in the formation of EP cells was neglected by the experiments in which the inhibition of the reactivities of P or EP by antisera to P, C3, B, D or immunoglobulins were investigated. The reduction in reactivities of P to E, or of EP to B, D and C3 was observed only when pretreated with antiserum to P. Furthermore, EP cells were agglutinated only by anti-P, not by antisera to C3 or IgG. The other possibility of participation of the classical complement components such as antibody, C1, C4 and C2 in the formation of EPB(D)C3 was excluded by the non-reactivities of EP with C4 and C2 and of EAC1 with B, D and C3. Thus, activated properdin is likely to function not only as modulator of preformed enzyme such as C3bBb but also as one of early-acting components of the alternative pathway.

Agglutination↗

Influence of aromatic compounds on the interaction of activated C4 with EAC1.

The influence of amino acids and their derivatives on the formation of SAC14 from SAC1 and C4 were investigated. Among the compounds tested, aromatic amino acids containing phenolic hydroxyl group or carbobenzoxyl group inhibited the formation of SAC14. When aromatic compounds other than amino acids were tested, the inhibitory capacities of these compounds were found to relate to the substituent group incorporated in the aromatic ring. Aromatic compounds with subsituent groups with negative Hammett's substituent constant showed stronger inhibition. Conversely, compounds with group with positive constant showed weaker inhibition. These results may suggest that the increased electron density in the aromatic ring is responsible for the inhibition. Regardless of inhibition of SAC14 formation, these inhibitors did not affect the enzymatic action of EAC1 or C1 on C4 but inhibited the binding of activated C4 to EAC1.

Agglutination Tests↗

Complement system in human colostrum: presence of nine complement components and factors of alternative pathway in human colostrum.

Evidence has been obtained for the presence in human colostrum of all nine components of complement (C), C1 through C9, and factors of the alternative pathway. Samples of colostrums collected from five women at 1-4 days after normal parturition were assayed for the haemolytic activities of individual components. As compared with normal human sera, the activities of each component ranged from 0.03 to 7% of those in sera. The activities of C4, C7 and C9 were relatively high, while that of C1 was extremely low. In most of the cases, the activities of individual components gradually increased following delivery, when expressed as the activity per unit weight (g) of protein in the colostrum. When the colostrums were treated with cobra venom factor, most of the colostrums showed 10-20% reduction in the C3 activity. This finding indicates the presence of factors such as B and D which are involved in the activation of C through the alternative pathway. The role as a defense factor of the C system in human colostrum and milk is discussed in connection with the ability of secretory IgA to react with C.

Colostrum↗

Reaction of an activated complex of guinea-pig complement components, C56, with unsensitized erythrocytes and with erythrocytes carrying C3b molecule.

During the interaction of guinea-pig complement intermediate cells, EAC423, with guinea-pig C5 and C6, an activated complex of C5 and C6, C56, was demonstrated in the fluid phase of the reaction mixture. C56 also was eluted from EAC42356 which had been generated by the interaction of EAC423 with C5 and C6. Both preparations of C56 showed quite similar characteristics and were not distinguished from one another. Both were capable of reacting with unsensitized erythrocytes (E) in the presence of C7 to form EC567. Further, they were able to react with EAC43 in the absence of C7 to form EAC43568 but did react with EAC43 pretreated with C3b inactivator, dithiothreitol or N-bromosuccinimide. These results indicate that guinea-pig C56 generated on EAC423 has a tendency to dissociate into the fluid phase. Nevertheless, the dissociated C56 can bind again to intact C3b molecule on the cells. The ability of cell-bound C3b to combine with C56 may lead to localization of C56 to the cell membrane carrying C3b, resulting in acceleration of attachment of C567 to the membrane. This assumption could be supported by the finding that the replacement of E by EAC43 increased the susceptibility of the cells to lytic action of complement induced by cobra venom factor. Thus, a new function of cell-bound C3b as localizing C56 to the membrane of sensitized cells was indicated.

Animals↗

Preparation and effects of an anti-B cell serum.

An heterologous antiserum specific for bone marrow-derived cells (B cells) was prepared by immunizing rabbits with lymph node cells from nude mice. After absorption with mouse red blood and thymus cells, the antiserum killed a population of cells from various lymphoid organs and the cytotoxic effects were inversely related to those of anti-theta antibody. When bone marrow or spleen cells were treated with the antiserum and guinea pig complement before transfer into irradiated mice, the number of plaque-forming cells was greatly reduced in the spleen of the recipient. Pretreatment of thymus cells with the antiserum in a similar way resulted in no inhibition of hemolytic plaque. When spleen cells from mice previously immunized with sheep red blood cells were treated with the antiserum and complement, the formation of hemolytic plaque was not affected. These findings indicated that the antiserum was specific for B cells and that the number of antigenic determinants on B cells to which the antiserum reacted decreases during differentiation into antibody-forming cells.

Absorption↗