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Biomedical subjects

M Namba

Publications and source records attributed to M Namba.

At least 199 records · Page 11Linked to original sources
PubMed1990

Enhancing effect of S-(1,2-dicarboxyethyl)glutathione on epidermal growth factor-stimulated DNA synthesis in primary cultures of adult rat hepatocytes.

A tripeptide S-(1,2-dicarboxyethyl)glutathione (DCE-GS) has been reported to be present in the lens, liver, and heart. Effects of DCE-GS and its derivatives and analogues on hepatocyte deoxyribonucleic acid (DNA) synthesis were examined using primary cultures of adult-rat hepatocytes. DCE-GS alone had no effect on DNA synthesis of hepatocytes. However, when DCE-GS was added with epidermal growth factor (EGF), the tripeptide effectively enhanced EGF-stimulated DNA synthesis of hepatocytes under the culture conditions of low cell density, but not high cell density. On the other hand, some esters and amides of DCE-GS and DCE-GS analogues showed a suppressive effect on DNA synthesis of hepatocytes in the absence of EGF. The derivatives and analogues together with EGF had no effect or rather a suppressive effect on stimulation of hepatocyte DNA synthesis by EGF. Therefore, the two carboxy groups in the substituent probably play an important role in the stimulative activity of DCE-GS. In addition, it seems likely that one of in vivo physiological roles of DCE-GS is related to liver regeneration.

Animals↗
PubMed1990

Class II major histocompatibility antigen expression on coronary arterial endothelium in a patient with Kawasaki disease.

To investigate the class II major histocompatibility antigen expression on coronary arterial endothelium of Kawasaki disease and immunophenotypes of the infiltrating cells in the coronary vascular lesions, myocardial sections from a patient who died during the acute stage of Kawasaki disease were studied using an immunoperoxidase technique. The mononuclear cells in the lesions mainly consisted of macrophages and T cells, whereas B cells and NK/K cells were not seen. The majority of T cells reacted with Leu-3a antibodies, and only a few reacted with Leu-2a antibodies. Cells bearing the interleukin-2 receptor, indicative of activated T cells, were also found in the lesions. To determine the distribution of class II antigen, we used anti-HLA-DR antibodies. The massive expression of HLA-DR antigen on mononuclear cells was found in the lesions. In addition, the HLA-DR activation antigen was expressed on the coronary arterial endothelium at the infiltrates in which macrophages and T cells coexisted. In contrast, coronary arterial endothelium did not express HLA-DR antigens in the myocardial tissues of controls (n = 4). HLA-DR+ endothelial cells may play an important role in the development of Kawasaki vasculitis.

Coronary Vessels↗
PubMed1990

Cytokeratin expression in human cell lines derived from liver tumors.

Immunohistochemical staining of cell lines derived from human liver tumours showed that five cell lines derived from hepatocellular carcinoma (HCC) and hepatoblastoma were stained positively with monoclonal keratin antibodies, CK-5 (Ker-18-specific) and KL-1 (broad specificity), but not with CK-7 (Ker-7-specific). On the other hand, four carcinoma cell lines derived from the biliary system were stained positively with not only CK-5 and KL-1, but also CK-7.

Albumins↗
PubMed1990

Mutagenic effects of ferric nitrilotriacetate (Fe-NTA) on V79 Chinese hamster cells and its inhibitory effects on cell-cell communication.

Ferric nitrilotriacetate (Fe-NTA) induced dose- and time-dependent mutation of V79 Chinese hamster cells to 6-thioguanine resistance. It also caused dose-related inhibition of metabolic cooperation. However, no significant induction of chromosome aberrations was detected in cells treated with Fe-NTA up to 100 micrograms Fe/ml of the drug even after treatment for 3 days. Our results indicate that Fe-NTA has mutagenic effects on V79 cells and inhibitory effects on cell--cell communication, and these effects may contribute to NTA-Fe-induced neoplastic transformation of mammalian cells.

Acetates↗
PubMed1990

[A case of penicillin-resistant pneumococcal meningitis and antibiotic susceptibility of Streptococcus pneumoniae isolated from children].

Recently, isolation of penicillin-resistant S. pneumoniae has been increasing. The first Japanese case of penicillin-resistant pneumococcal meningitis was reported in 1988. We experienced a case of a one-year-old boy with penicillin-resistant pneumococcal meningitis who dead on arrival on his third day of illness. Minimal inhibitory concentration (MIC) of penicillin G or S. pneumoniae isolated from cerebrospinal fluid and blood was 0.6 micrograms/ml. We evaluated the antibiotic susceptibility of 163 strains of S. pneumoniae isolated from children from 1985 to 1988. Penicillin G (PCG), ampicillin (ABPC), cefotaxime (CTX), imipenem (IPM), and vancomycin (VCM) had good susceptibilities to S. pneumoniae. Twelve of the 163 isolates (7.3%) were penicillin-resistant strains whose MIC of PCG were more than 0.1 microgram/ml, and all of them were intermediately resistant. The annual penicillin-resistant rates were 12.5% in 1985, 1.3% in 1986, 0% in 1986, and 19.0% in 1988. We also evaluated the MIC distribution and MIC90 of antibiotics available for meningitis against penicillin-sensitive and -resistant S. pneumoniae. MIC90 of PCG and ABPC against penicillin-resistant strains was 1.56 micrograms/ml, and it might be dangerous to use PCG or ABPC for central nervous system pneumococcal infections. MIC90 of IPM against penicillin-resistant strains was 0.1 microgram/ml, and that of VCM was 0.4 micrograms/ml. There was little fall of susceptibilities of resistant strains in IPM and VCM. We evaluated the MIC distribution and MIC70 of antibiotics for oral usage against penicillin-sensitive and -resistant S. pneumoniae. Although there were falls of susceptibilities of resistant strains in PCG and ABPC, these two antibiotics had the best susceptibilities among the oral antibiotics.

Anti-Bacterial Agents↗
PubMed1990

Effects of antioxidants on V79 Chinese hamster cells treated with ferric nitrilotriacetate.

The cytotoxic effects of ferric nitrilotriacetate (Fe-NTA) have been considered to be caused by free radicals produced by the drug. The present study was carried out to determine whether or not cytotoxic effects of Fe-NTA on cell growth and lipoperoxide formation of Chinese hamster cells were reduced by antioxidants. Using a spin trapping technique, we found that hydroxyl radical formation in the cells increased in the presence of Fe-NTA. Antioxidants, with the exception of superoxide dismutase, slightly inhibited production of the hydroxyl radical. Mannitol significantly reduced lipoperoxide formation, but other antioxidants did not. However, the growth inhibitory effects of Fe-NTA were not attenuated by these antioxidants. These results indicated that the cytotoxic effects of Fe-NTA may be mostly due to unknown factors other than oxygen free radicals.

Animals↗
PubMed1989

Presence of glucagon-(1-21)-Like immunoreactive substance in the dog small intestinal mucosa.

By using an antiserum (K291) specifically directed to the C-terminal of glucagon-(1-21)-peptide, we demonstrated the presence of glucagon-(1-21)-like immunoreactivity (G21-IR) in the dog intestine. G21-IR was found to be widely distributed throughout the small intestine and colon in parallel with the distribution of glucagon-like immunoreactivity (GLI), measured by N-terminal glucagon antiserum (OAL196). The subsequent analyses by gel filtration and three HPLC columns (reverse phase, ion exchange and further reverse phase columns) showed that G21-IR consisted of three main peaks, and the smallest molecular form of G21-IR is identical to glucagon-(1-21)-peptide.

Amino Acid Sequence↗
PubMed1989

Establishment of five human myeloma cell lines.

Five human myeloma cell lines, KMM-1, KMS-5, KMS-11, KMS-12-PE, and KMS-12-BM, have been established at Kawasaki Medical School since 1980. As the KMS-12-PE and KMS-12-BM lines were obtained from the same patient, these five cell lines have been derived from four patients with multiple myeloma. The five myeloma cell lines are stably growing at present in RPMI 1640 medium supplemented with 10% fetal bovine serum. They can also grow in a defined culture medium without serum. That these cell lines were human myeloma cells was confirmed by the following findings. Ultrastructurally, all five cell lines showed features characteristic of plasma cells. KMM-1 and KMS-11 cells secreted lambda and kappa chains into the culture medium, respectively, but the other cell lines produced no immunoglobulins. KMM-1 expressed cytoplasmic lambda antigen, KMS-5 showed cytoplasmic delta, and KMS-11 expressed surface kappa, whereas KMS-12-PE and KMS-12-BM cells showed no surface or cytoplasmic immunoglobulins. Regarding reaction with a monoclonal plasma cell antibody (PCA-1), four of the five lines were positive, the exception being KMS-5. Another monoclonal antibody (CD38), which also recognizes plasma cells, responded to KMM-1, KMS-12-PE, and KSM-12-BM. KMS-5 cells expressed acute lymphoblastic leukemia antigens (CALLA). These data suggest that such lines as KMM-1, KMS-11, KMS-12-PE, and KMS-12-BM represent later stages of B-cell differentiation, and that KMS-5 represents a relatively early stage of B-cell differentiation. All the cell lines lacked Epstein-Barr virus nuclear antigen, showed abnormal karyotypes of human origin, and differed from each other in the isozyme patterns examined. Only KMS-5 was tumorigenic when transplanted subcutaneously into nude mice.

Aged↗
PubMed1989

A decrease in hyaluronic acid synthesis by aging human fibroblasts leading to heparan sulfate enrichment and growth reduction.

Cultured normal human fibroblasts during in vitro aging exhibited increased proportions of heparan sulfate (HS; a glycosaminoglycan (GAG) species) in the cell-associated GAG pool, coincident with decreased cell growth activity. An analysis of GAG metabolism demonstrated that human fibroblasts during aging became relatively rich in HS due to an alteration in the profile of GAG synthesis. HS became relatively enriched and hyaluronic acid (HA) relatively depleted through a decrease in HA synthase activity. An experimental enrichment of human fibroblast cultures with exogenous HS brought about an arrest of the cells in the G0/G1 phase and a decrease in the rate of S phase entry, coincident with aged cell growth behaviour. These results suggest that the change in HA synthesis is responsible, at least to some extent, for the growth reduction during aging of normal human fibroblasts.

Cell Division↗
PubMed1989

Effect of glucagon-(1-21)-peptide on secretin-stimulated pancreatic exocrine secretion in anesthetized dogs.

The effects of glucagon-(1-21)-peptide on pancreatic exocrine secretion and plasma glucose levels were studied and compared with those of native glucagon in anesthetized dogs. Intravenous bolus administration of 1 nmol or 10 nmol/kg of glucagon-(1-21)-peptide evoked a significant inhibition of secretin-stimulated pancreatic juice secretion and protein output in a dose-dependent manner, as equimolar doses of glucagon did. Native glucagon induced an immediate and transient increase in pancreatic juice volume, which was followed by a significant inhibition. However, glucagon-(1-21)-peptide showed only the inhibitory action. Glucagon-(1-21)-peptide had no effect on plasma glucose levels even when a dose of 10 nmol/kg was given. The results suggest that the N-terminal amino-acid residues of glucagon play an important role in the inhibition of pancreatic exocrine secretion.

Animals↗
PubMed1989

Two human myeloma cell lines, amylase-producing KMS-12-PE and amylase-non-producing KMS-12-BM, were established from a patient, having the same chromosome marker, t(11;14)(q13;q32).

Two human myeloma cell lines, KMS-12-PE and KMS-12-BM, were established from a 64-year-old woman with a non-producing type of multiple myeloma. The KMS-12-PE line originated from the pleural effusion and the KMS-12-BM from the bone marrow. These two lines showed the same chromosome marker, t(11:14)(q13:q32). However, their phenotypes of surface markers differed from each other. KMS-12-BM cells were positive to CD20, CD38 and PCA-1. showing the plasmacytoid (immature plasma cell) stage of B-cell differentiation, while KMS-12-PE cells were positive to CD38 and PCA-1, but not to CD20, indicating the terminal differentiated stage of B-cells. As seen in the pleural effusion of the patient. KMS-12-PE cells ectopically produced a salivary type of amylase, but KMS-12-BM cells did not. Interestingly, the chromosome abnormality of del(1)(p22----pter) near the region of 1p21, where the amylase gene was assigned, was noticed in as many as 76% of KMS-12-PE cells.

Amylases↗
PubMed1989

Glucagonostatic and insulinotropic action of glucagonlike peptide I-(7-36)-amide.

We examined the effect of glucagonlike peptides (GLPs), which are cleaved from preproglucagon in the enteroglucagon cells, on rat endocrine pancreas with the isolated perfused system. GLP-I-(7-36)-amide, a truncated form of full-sequence GLP-I-(1-37), showed a potent inhibitory effect on glucagon secretion. This inhibitory effect of GLP-I-(7-36)-amide was demonstrated at concentrations of 0.25, 2.5, and 25 nM in 11.2 and 2.8 mM glucose. In contrast, insulin release was significantly stimulated by GLP-I-(7-36)-amide at its concentration from 0.025 to 25 nM in a high glucose concentration, whereas in a low glucose concentration, the stimulation was seen only at the highest concentration (25 nM). Neither GLP-I-(1-37) nor GLP-II showed any effect on glucagon and insulin release. Although several gastrointestinal hormones have been nominated as incretins, none of them may suppress the glucagon secretion. A truncated form of GLP-I, GLP-I-(7-36)-amide thus seems to be a unique incretin that exerts glucagonostatic action.

Animals↗
PubMed1989

[Plasma and tissue concentration of tegafur by a new soft capsule type suppository in colorectal carcinoma].

Plasma, tissue, and Lymph-node concentrations of tegafur and 5-FU were examined in 19 patients with colonic and rectal carcinoma after administration of tegafur by a new soft capsule type suppository: Plasma levels of tegafur and 5-FU after administration by soft capsule were much higher than those seen using supp. type suppositories. Tissue levels of 5-FU were high in tumor tissue compared to levels found in adjacent normal tissue. Lymph node levels of 5-FU were higher than plasma levels. Lymph node levels of 5-FU in the first-group lymph nodes were higher than in the second-group. These results suggest the clinical usefulness of administration of tegafur by soft-capsule suppository.

Aged↗
PubMed1989

[Establishment and characterization of five human myeloma cell lines].

Since 1980 five human myeloma cell lines, KMM-1, KMS-5, KMS-11, KMS-12-PE and KMS-12-BM, have been established in Kawasaki Medical School. Histologically, all the cell lines resembled plasma cells and were EBNA negative. KMM-1, KMS-11, KMS-12-PE and KMS-12-BM reacted with PCA-1, while KMM-1, KMS-12-PE and KMS-12-BM with CD38. KMM-1 and KMS-11 secreted immunoglobulins into culture medium. Karyologically, all the cell lines were abnormal. Only KMS-5 was tumorigenic when transplanted subcutaneously into nude mice.

Aged↗