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Biomedical subjects

T Osawa

Publications and source records attributed to T Osawa.

At least 199 records · Page 11Linked to original sources
PubMed1992

Effects of postnatal electroshock convulsions on epileptogenesis of the amygdala and hippocampus in adult rats.

Adult rats which received repeated electroshock convulsions (ESCs) during postnatal development underwent electrical kindling of the amygdala (AM) and hippocampus (HIPP). Completion of kindling, especially AM kindling, was significantly faster in the groups with ESCs from the neonatal to late infantile age than in the control group. It is discussed that especially the late infantile age in the postnatal development was supposed to play an important role in the faster kindling brought about by postnatal convulsions and that the faster kindling was due in part to abbreviation of the partial seizure process. However, the neonatal ESC group showed significantly delayed completion of HIPP kindling.

Amygdala↗
PubMed1992

Synthesis and anti-inflammatory activity of antioxidants, 4-alkylthio-o-anisidine derivatives.

In order to search for anti-inflammatory agents against autoimmune diseases, we synthesized 4-alkylthio-o-anisidine derivatives possessing antioxidant activity, and tested them for anti-inflammatory activity against the Arthus reaction in mice. Experimental inflammations, including the Arthus reaction, concanavalin A, phorbol ester and pyrophosphate-induced edemas in rats were inhibited by 4-propylthio-o-anisidine, which inhibited autoxidation of rat brain homogenate and suppressed the lipopolysaccharide-induced increase in the plasma malondialdehyde level in mice. An antioxidant may be an effective agent in immune complex type inflammation where active oxygen species play an important role.

Aniline Compounds↗
PubMed1992

Lipid peroxidation of liposome induced by glucosone.

Lipid peroxidation of liposome made of egg lecithin was induced by glucosone (D-arabino-hexos-2-ulose), a secondary product of Maillard reaction or glycation of protein. Lipid peroxidation was assessed with measurement of TBARS (thiobarbituric acid reacting substances), POV (peroxide value), and HPLC measurement of MDA (malondialdehyde). EDTA and DTPA (diethylenetriamine-pentaacetic acid) inhibited the lipid peroxidation assessed by each method described above, indicating involvement of metal ions. The observed reduction of Fe3+ to Fe2+ by glucosone might be a critical step of the lipid peroxidation. Our findings suggest a possible role of lipid peroxidation of low-density lipoproteins (LDL) induced by glucosone in atherosis caused by diabetes mellitus.

Chromatography, High Pressure Liquid↗
PubMed1992

[Intraoperative blood recovery in transurethral resection of prostate (TURP)].

Blood collected from irrigating fluid in TURP was studied if it was appropriate blood as autologous transfusion or not. TURP was performed aided by continuous irrigation through suprapubic cystostomy. The cystostomy tube was connected to the Shiley STAT or Haemonetics Cell Saver in 15 patients. The average weight of resected adenoma was 36 g per patient. The product of washed blood gave an average yield of 440 ml per patient with an average RBC count of 469 x 10(3)/mm3, hemoglobin of 14.6 g/dl, hematocrit of 44.8%, platelets of 15400/mm3. The half-life of collected red blood cells tagged with 55Cr was 22 days. The urine in 10 patients (67%) were contaminated with bacteria before TURP, and 3 of collected blood were contaminated with bacteria (20%). As for carcinoma cells, cultured urinary bladder carcinoma cells (T24) and renal carcinoma cells (ACHN) were completely eliminated after filtration through leukocyte removal filter Sepacell or Pall RC. As results, the intraoperatively collected blood from irrigating fluid in TURP was useful and safe as autologous blood transfusion.

Blood Transfusion, Autologous↗
PubMed1992

[Autologous blood retransfusion in transurethral resection of prostate (TURP)].

UNLABELLED: Blood collected from the irrigation fluid used during TURP was retransfused in 17 patients. Of the 17 patients, 8 cases were also transfused preoperatively reserved blood. The weight of resected adenoma (g), resection time (minutes), the volume of salvaged blood (ml) of 9 cases who were transfused only salvaged autologous blood were 30.6 g, 63 min. and 355 ml, respectively, and those of 8 patients who were given both salvaged and preoperatively reserved autologous blood were 46.1 g, 78 min. and 703 ml, respectively. No patient was transfused homologous blood. Preoperative urine cultures showed contamination of bacteria in 12 cases (70.6%), and the blood concentrated from irrigated fluid was positive for bacteria in 2 cases (11.8%). Blood count (RBC, Hb, Ht) just after TURP, after blood retransfusion, at the next and the 7th day after the operation were compared to those of just before TURP (Blood Count Ratio). The ratio of the 9 cases who received only salvaged blood were 83.5%, 96.8%, 90.9%, 85.2% each and the ratio of the 8 cases who were transfused both salvaged and preserved blood were 86.9%, 102.6%, 101.4%, 97.5% each. There were no adverse effects due to the autologous blood retransfusion. CONCLUSION: Retransfusion of salvaged autologous blood from the irrigating fluid of TURP was clinically safe and effective. No homologous blood was transfused in TURP when salvaged autologous blood with or without preserved blood was retransfused to the patient.

Blood Transfusion, Autologous↗
PubMed1992

[Sequential methotrexate and 5-fluorouracil, doxorubicin, and cisplatin for advanced urothelial cancer].

Twenty cases (fourteen males, six females, mean age 66.0) with locally advanced (T2-4 N0, M0, n = 9) or metastatic (N2-3 or M1, n = 11) urothelial cancer were treated sequentially with methotrexate (MTX) and 5-fluorouracil (5-FU), Doxorubicin (ADM), and cisplatin (CDDP) since August, 1988. Primary tumors were in the bladder in fifteen patients and in the renal pelvis or ureter in five cases. Histological findings were adenocarcinoma in one and transitional cell carcinoma in the other cases. Histological grades were grade 2 in four, grade 3 in fifteen, poorly differentiated adenocarcinoma in one. Seven patients were treated by neoadjuvant chemotherapy. Three were treated for recurrent lesions. Ten were treated for the unresectable disease. The patients received one to four cycles of this regimen (average: 2.8 cycles). Complete clinical response was observed in seven of twenty patients (35%) with measurable indicator lesions. Seven patients (35%) had a partial clinical response. Significant tumor regression was noted in fourteen of twenty patients (70%) in total, in eight of ten (80%) treated with full dose chemotherapy. The group of full dose chemotherapy showed an improved trend in survival rate as compared with the group treated by 80% and less dose chemotherapy. Toxicity was relatively mild, with anemia, leukopenia, thrombocytopenia, and no drug related death. The results suggest that the combined chemotherapy with sequential MTX and 5-FU, ADM, and CDDP is remarkably effective on advanced urothelial cancer.

Adenocarcinoma↗
PubMed1991

Enhancement by IL-1 beta and IFN-gamma of platelet activation: adhesion to leukocytes via GMP-140/PADGEM protein (CD62).

We have examined the effect of inflammatory cytokines on the platelet activation. IL-1 beta and IFN-gamma were found to enhance the adhesion of thrombin-treated platelets to monocytic leukemia cells (U937), when the adhesion was assayed by platelet-mediated cell agglutination. The agglutination was inhibited by a monoclonal anti-GMP140 antibody or EDTA, suggesting that the enhanced platelet adhesion to the leukemic cells was mediated by GMP140. In addition, these cytokines also increased the release of 5-HT from platelets in the presence of a low concentration of thrombin. These data suggest that platelet functions are regulated by the cytokines and that activated platelets participate in inflammatory process.

Blood Platelets↗
PubMed1991

Purification and characterization of a carbohydrate-binding peptide from Bauhinia purpurea lectin.

In order to examine the correlation between the amino acid sequence and sugar binding specificity of Bauhinia purpurea lectin (BPA), a galactose and lactose binding lectin, a peptide which interacts with lactose was purified from an Asp-N endoproteinase digest of BPA by means of affinity chromatography on a column of lactose-Sepharose. The amino acid sequence of this peptide is Asp-Thr-Trp-Pro-Asn-Thr-Glu-Trp-Ser. A tryptic fragment having the ability to interact with lactose was also purified and found to contain the above sequence, consisting of 9 amino acids. The chemical synthesis of this peptide was carried out by the solid-phase method and the synthetic peptide was found to exhibit lactose binding activity in the presence of calcium.

Amino Acid Sequence↗
PubMed1991

Inhibitory effect of lichen constituents on mutagenicity induced by heterocyclic amines.

Physodic acid, one of the main constituents of Hypogymnia enteromorpha, inhibited the mutagenicity of indirect mutagens, including benzo[a]pyrene and heterocyclic amines in Salmonella typhimurium TA 98. In contrast, it was not effective against direct mutagens such as 6-nitropiperonal and adriamycin. Its antimutagenicity was not associated with free-radical scavenging or antioxidative activities. Physodic acid seemed to inhibit the formation of reactive metabolites, such as N-hydroxy-Trp-P-2, by blocking the hepatic microsomal oxidation systems. Another component of H. enteromorpha, physodalic acid, also inhibited mutagenicity of a heterocyclic amine, Trp-P-2, in S. typhimurium TA 98, even though it was reportedly mutagenic in S. typhimurium TA 100.

Animals↗
PubMed1991

TNF-mediated cytotoxicity. Importance of intracellular cGMP level for determining TNF-sensitivity.

Previous work on the cytolytic action of activated macrophages indicated that tumor necrosis factor (TNF) showed synergistic cytolytic activity with NO, which has been shown to act as a cyclic GMP (cGMP) generator [Higuchi et al., J. Immun. 144, 1425-1431, (1990)]. In this study, we investigated the relationship between the accumulation of intracellular cGMP and the cytotoxic action of TNF. It was demonstrated that TNF-mediated cell lysis was closely related to the background level of intracellular cGMP, and that the accumulation of cGMP within TNF resistant cells induced TNF sensitivity. We reached these conclusions on the basis of the following results; (1) agents (sodium nitroprusside and isobutylmethylxantine) that cause the accumulation of cGMP intracellularly increased the TNF-sensitivity of TNF-resistant cells; (2) the addition of dibutyryl cGMP to TNF-resistant cells increased the TNF-sensitivity; and (3) treatment at 40 degrees C or agents such as interferon gamma and actinomycin D, that synergistically kill tumor cells together with TNF, potentially increased the cGMP level. Therefore, intracellular cGMP may be one of the key molecules that lead to cell death caused by TNF.

Animals↗
PubMed1991

Neurotropin inhibits experimental allergic encephalomyelitis (EAE) in Lewis rats.

The effects of Neurotropin, a substance extracted from the inflammatory dermis of rabbits inoculated with Vaccinia virus, for experimental allergic encephalomyelitis (EAE) in Lewis rats, a model for human multiple sclerosis (MS), was studied. The peptide defined by residues 68-84 (MB 68-84) which corresponds to the encephalitogenic portion of the guinea pig myelin basic protein (MBP) in complete adjuvant H37Ra (CFA) was injected into the hind foot pad of each rat. Neurotropin significantly suppressed the clinical and histological expression of actively induced EAE when administered i.p. daily from day 0 to day 6 after immunization. In addition, passive EAE induced by precultured spleen cells from rats immunized with MB 68-84 in CFA was also suppressed by daily administration of Neurotropin after cell transfer. Neurotropin treatment significantly suppressed the delayed-type hypersensitivity (DTH) response to MB 68-84. Furthermore, the ability of spleen cells from Neurotropin-treated rats to transfer EAE was significantly lower than that of saline-treated rats. It seemed that the suppression may be due to the inhibition of the activation by MB 68-84 of sensitized spleen cells, as demonstrated by proliferative response to MB 68-84. However, no difference was observed in Con A-induced proliferative response of the spleen cells between Neurotropin- and saline-treated rats. These findings indicate that Neurotropin inhibits EAE by suppressing the immune responses to encephalitogenic MBP with little non-specific suppression.

Animals↗
PubMed1991

The primary structures of two types of the Ulex europeus seed lectin.

The complete amino acid sequences of the Ulex europeus anti-H(O) lectins I and II were determined by using a protein sequencer. After digestion with endoproteinases Lys-C and Asp-N of the lectins reduced with 2-mercaptoethanol and modified with iodoacetamide, the resulting peptides were purified by reversed-phase high-performance liquid chromatography and subjected to sequence analysis. The complete primary structures of these two Ulex lectins I and II were compared with those of nine lectins already determined, including that of Lotus tetragonolobus anti-H(O) lectin which we have determined. Extensive homologies were found among them.

Amino Acid Sequence↗
PubMed1991

Identification of human galactoprotein b3, an oncogenic transformation-induced membrane glycoprotein, as VLA-3 alpha subunit: the primary structure of human integrin alpha 3.

Galactoprotein b3 is one of the cell membrane glycoproteins of fibroblasts showing enhanced expression in association with oncogenic transformation. Analysis of cDNA for this glycoprotein from hamster fibroblasts indicated that the glycoprotein is a member of the integrin superfamily [Tsuji, T., Yamamoto, F., Miura, Y., Takio, K., Titani, K., Pawar, S., Osawa, T., & hakomori, S. (1990) J. Biol. Chem. 265, 7016-7021]. In the present study, we examined the change in the amounts of mRNA for the mouse and human counterparts in fibroblasts after oncogenic transformation by Northern blot analysis using hamster galactoprotein b3 cDNA as a probe. In both human and murine fibroblasts transformed with SV-40, the homologous mRNA to galactoprotein b3 was also found to increase as compared with the progenitor cells. The human homologue of galactoprotein b3 cDNA was cloned from human bladder carcinoma cell line (T24) cDNA library. The cDNA codes for a single polypeptide of which the N-terminal sequence (21 amino acids) is identical with that of human VLA-3 alpha subunit. Based on this sequence identity and the structural similarities (i.e. the positions of most cysteine residues, the presence of a transmembrane domain near the C-terminus and the presence of metal binding sequences) with other integrins so far cloned, we conclude that human galactoprotein b3 is an integrin alpha 3 subunit. The mature integrin alpha 3 polypeptide was composed of 1,019 amino acid residues, and the overall structure was quite similar to the hamster counterpart.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1991

cDNA cloning and expression of Bauhinia purpurea lectin.

Bauhinia purpurea lectin (BPA) was purified from seeds of B. purpurea alba. The purified lectin was digested with an endoproteinase, Asp-N, or trypsin and then the amino acid sequences of the resultant fragments were analyzed. Furthermore, a cDNA library for BPA was constructed using RNA isolated from germinated Bauhinia purpurea seeds. By gene cloning, the nucleotide sequence of BPA cDNA and its deduced amino acid sequence were analyzed. The cloned BPA cDNA comprised 1,152 nucleotides and the open reading frame of the cDNA encodes a polypeptide of 290 amino acids including a signal peptide composed of 28 amino acids. BPA expressed in Escherichia coli showed a relative molecular mass of 29 kDa on sodium dodecyl sulfate-polyacrylamide gel. On comparison of its sequence with those of other leguminous seed lectins, BPA showed high homology to the others.

Amino Acid Sequence↗
PubMed1991

Human monocytes in a long-term culture with interleukin-2 show high tumoricidal activity against various tumor cells.

We compared the tumoricidal activity of human monocytes cultured with interleukin-2 (IL-2) or human recombinant interferon-gamma (IFN-gamma) alone, or IFN-gamma in combination with a small amount of lipopolysaccharides (LPS). Human monocytes cultured with IL-2 for 7 days or longer, termed lymphokine-activated macrophages (LAMs), showed higher tumoricidal activity than those cultured for 1 day. In contrast, monocytes cultured with IFN-gamma alone or in combination with LPS for 7 days or longer showed lower tumoricidal activity. LAMs were identified as macrophages by nonspecific esterase staining and immunofluorescence staining with anti-CD14 antibody. LAMs were not induced in fetal calf serum-containing medium, but they were induced when colony-stimulating factor-1 was added to the medium. LAMs showed high tumoricidal activity against all human and murine tumor cell lines tested, although they showed no cytotoxic activity against human normal cells. During incubation with IL-2, tumoricidal activity of LAMs was maximal at days 8-16 and was sustained until day 28. The difference in tumoricidal mechanism between LAMs and lymphokine-activated killer (LAK) cells was also shown by using two kinds of cytotoxic assay systems. LAMs require a long incubation time to kill tumor cells, but LAK cells can kill them immediately. Furthermore, LAMs kill tumor cells with complete DNA degradation, whereas LAK cells can induce significant but not complete DNA degradation. These results indicate that LAMs and LAK cells have different tumoricidal mechanisms for killing target cells, although they were induced by incubation with the same lymphokine, IL-2.

Animals↗
PubMed1991

Macrophage migration inhibitory factor (MIF) produced by a human T cell hybridoma clone.

A human T cell hybridoma clone, F5, producing high levels of macrophage migration inhibitory factor (MIF) was established by the emetine-actinomycin D selection method. This clone produced two species of MIF which were separated on a Phenyl Sepharose column. We purified MIF-2 (the more hydrophobic species of the two) to homogeneity from the conditioned medium of stimulated F5 cells by a series of steps that included hydrophobic chromatography, ion-exchange chromatography. Ricinus communis lectin affinity chromatography, and high-performance liquid chromatography on anion exchange and reverse-phase columns. Purified MIF was digested with endoproteinase Lys-C and Asp-N. The amino acid sequences of the generated peptides were determined. No sequence similarity with any other protein was found. The molecular weight of MIF-2 was estimated to be 45 kDa from sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of immunoprecipitates with anti-peptide antibodies. These results show that F5MIF-2 is a novel cytokine.

Amino Acid Sequence↗