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M Aihara

Publications and source records attributed to M Aihara.

At least 199 records · Page 11Linked to original sources
PubMed1987

Comparison of the effects of Fe2+ and Cu2+ on prostaglandin synthesis in rabbit kidney medulla slices.

The effects of Fe2+ and Cu2+ on the generation of medullary prostaglandins E2 and F2 alpha have been compared. Fe2+ markedly promoted the lipid peroxidation of rabbit kidney medulla slices. The lipid peroxidation induced by Fe2+ inhibited both prostaglandin E2 and prostaglandin F2 alpha formation to a similar extent. While Cu2+ produced only a small increase in lipid peroxidation, it had a powerful inhibitory effect on prostaglandin E2 formation. Simultaneously, prostaglandin F2 alpha production was increased. In the presence of Cu2+ the net increased amount of prostaglandin F2 alpha was much smaller than the net decreased amount of prostaglandin E2 (15-20%). These results suggest that Cu2+ has the potential to modulate prostaglandins E2 and F2 alpha synthesis by affecting endoperoxide E2 isomerase or endoperoxide reductase independent of its peroxidative action.

Animals↗
PubMed1987

Effect of pyridoxine on prostaglandin synthesis in rabbit kidney medulla slices.

Pyridoxine stimulated the generation of prostaglandin E2 in rabbit kidney medulla slices. Moreover, pyridoxine in the presence of aspirin reduced the release of linoleic acid, but enhanced the release of arachidonic acid from the medulla slices as compared with aspirin alone, indicating that the enhancement of prostaglandin E2 formation elicited by pyridoxine may be ascribed to an increased conversion of linoleic acid to arachidonic acid. These results suggest that pyridoxine can be an important modulating factor in prostaglandin synthesis by the kidney.

Animals↗
PubMed1987

Two affinity immunoelectrophoretic methods for studying collagen interaction with von Willebrand factor antigen.

Two new immunoelectrophoretic methods are described for studying the interaction of collagen fibrils with von Willebrand factor antigen (vWF: Ag). In the first, the sample was electrophoresed through a collagen-agarose wedge into an antibody-agarose area, and immunoprecipitin lines was detected by staining. Different immunoprecipitin patterns were obtained with the vWF: Ag of normal plasma, commercial FVIII preparations, and von Willebrand disease (vWD) type IIa plasma as the result of collagen binding of vWF: Ag. In the other method, the sample was electrophoresed into agarose for preliminary separation of forms, followed by migration in the second dimension through a collagen spacer gel into an antibody-agarose area. This method demonstrated preferential binding of high molecular weight forms of vWF: Ag in normal plasma and slight binding of the lower molecular weight forms of antigen found in vWD type IIa plasma. The affinity wedge method is a convenient general method for finding quickly a useful concentration of affinity reagent.

Antigens↗
PubMed1987

[Bilateral renal cell carcinoma: report of two cases].

Two cases of bilateral renal cell carcinoma are reported. The first case is of a 54-year-old male who visited our hospital on March 7, 1984 complaining of colicky pain in his left flank. Intravenous urography showed a large mass in the upper pole of the left kidney causing deformity and dislocation of the upper calyces. There were no remarkable findings in the right kidney. Abdominal CT-scan and arteriography revealed a round and hypervascular tumor with soft tissue mass density in the upper pole of both kidneys. Nephrectomy of the left and segmental resection of the upper pole of the right kidney were performed on April 11, 1984. The second case is a 47-year-old male who visited our hospital complaining of total gross hematuria. Intravenous urography showed a large soft tissue mass at the lower pole of the left kidney. Abdominal CT-scan revealed a large tumor mass associated with central necrosis in the left kidney and also a small tumor lesion at the center of the contralateral kidney. Bilateral nephrectomy was performed on December 19, 1984, and the patient was referred to hemodialysis treatment. The cut section of the nephrectomized right kidney specimen revealed multiple minor accessory tumors. Both patients have been doing well without any evidence of recurrence or metastasis.

Carcinoma, Renal Cell↗
PubMed1986

Effect of fibronectin and von Willebrand factor on the adhesion of human fixed washed platelets to collagen immobilized beads.

The adhesion of human fixed washed platelets (FWP) to collagen was measured using collagen immobilized beads. The addition of normal plasma or severe von Willebrand disease (VWD) plasma to FWP decreased the adhesion, suggesting the presence of some inhibitors of platelet adhesion in human plasma. Although the adhesion of FWP in severe VWD plasma was not different from that of FWP in normal plasma, the addition of purified von Willebrand factor (vWF, 1-2 mu/ml ristocetin cofactor) to FWP in buffer increased the FWP adhesion at higher flow rates, and the percent of adhesion in the absence of vWF was 10% (collagen 500 micrograms) and 30% (collagen 1,000 micrograms) of that in the presence of vWF at 10 ml/min. The enhancing effect of the vWF on FWP adhesion was also observed by pretreatment of the collagen column with vWF suggesting the important role of bound vWF to the collagen; adhesion 72% to the collagen column (1,600 micrograms) treated with vWF and 16% to the collagen column without the pretreatment at 10 ml/min. The promoting effect of vWF was also present in some commercial factor VIII preparations which had no large or intermediate multimers of vWF antigen. The adhesion of FWP was inhibited by fibronectin (FN) and the binding of ristocetin cofactor (vWF:RCo) to collagen fiber was also inhibited by FN; bound vWF:RCo to 50 micrograms/ml collagen in the absence or presence of 125 micrograms/ml FN were 60% and 8% respectively. It is suggested that vWF, even small multimer of vWF:Ag, is involved in the initial platelet-collagen interaction at high flow rates, while plasma FN acts as one of anti-adhesion factor.

Adult↗
PubMed1986

Visualization of von Willebrand factor multimers by immunoenzymatic stain using avidin-biotin peroxidase complex.

A technique for the detection of von Willebrand factor multimers separated by discontinuous SDS agarose electrophoresis has been developed using non-radioactive compounds. The multimeric patterns were visualized by monospecific anti-human vWF:Ag followed by incubation with biotinylated antibody. After addition of avidin-biotin-peroxidase complex, the peroxidase activity was detected by 4-chloro-1-naphthol, giving sharp bands with a clear background. By this method, the differences of vWF:Ag multimers could be easily observed between normal plasma and the plasmas from variant type vWD (IIA, IIB, platelet-type). Large and intermediate multimers were absent in the plasma with vWD type IIA, while only large multimers were absent in the plasma with vWD IIB and platelet-type. The absence of large multimers was also observed in two commercial FVIII preparations having the ratio of vWF/vWF:Ag 0.18 and 0.63. The preparation with the ratio of 0.63 showed the presence of larger intermediate multimers. Electrophoresis in SDS 1.5% agarose gel revealed triplet structure of each small multimer, and a relative increase of the smallest subband was observed in vWD IIA plasma, platelet-type vWD plasma and commercial FVIII preparations. The procedures described are easy and safe to perform and are useful for screening or classifying cases with vWD in general laboratories.

Avidin↗
PubMed1986

An attempt to produce "pre-T" cell hybridomas and to identify their antigens.

With the aim of identifying some of the stages in the development of pre-T cells (cells of the T cell lineage before they enter the thymus), we have produced a large number of hybridomas by the fusion of BALB/c bone marrow cells, bone marrow cells from BALB/c-nu/nu mice, BALB/c fetal liver cells and BALB/c fetal thymocytes with the AKR thymoma BW5147. The hybridomas were selected for the expression of the Thy-1.2 antigen of the normal cell donor and for their ability to produce interleukin 2 (IL 2) upon co-culture with irradiated normal spleen cells. A set of these hybridomas is described in this communication. The hybridomas were then used to immunize rats and to generate monoclonal antibody-producing B cell hybridomas. Most, if not all, of the immunizing hybridomas were derived from pre-T cells as evidenced by the fact that they produce IL 2, and express some of the T cell markers (the Thy-1.2, Ly-1, Ly-2 or L3T4 antigens). The monoclonal antibodies were tested on a panel of pre-T cell hybridomas and on normal cells obtained from spleen, lymph nodes, thymus and bone marrow. The testing was carried out by the microcytotoxicity assay and flow cytometric analysis. Three groups of antibodies could be distinguished. Some antibodies were broadly reactive, being positive with virtually all the clones in the pre-T cell panel and with a substantial fraction of normal lymphoid cells. The identity of the antigens detected by these antibodies remains unknown but they do not seem to correspond to any of the known cell surface markers. Other antibodies reacted only with some of the pre-T cell clones and did not react at all with normal lymphoid cells obtained from adult animals. Finally, other antibodies still reacted only with a minor subpopulation of thymocytes or of thymocytes and bone marrow cells, as well as some of the pre-T cell clones; they did not react with spleen and lymph node cells. These antibodies might be specific for cells in the prethymic phase of the T cell differentiation pathway. They should prove useful for the identification of pre-T cell markers and hence for the isolation of pre-T cells and their functional analysis.

Animals↗