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Biomedical subjects

M Matsuyama

Publications and source records attributed to M Matsuyama.

At least 73 records · Page 4Linked to original sources
PubMed1994

Autocrine factor enhancing the secretion of M(r) 95,000 gelatinase (matrix metalloproteinase 9) in serum-free medium conditioned with murine metastatic colon carcinoma cells.

We previously reported that murine tumor cells with a high spontaneous metastatic potential to the lung secrete higher amounts of M(r) 95,000 gelatinase (matrix metalloproteinase 9, MMP9) than do poorly metastatic cells. The present study, conducted to clarify the mechanisms underlying the increase in MMP9, revealed an autocrine factor that enhances the secretion of M(r) 95,000 gelatinase (MMP9). The secretion of MMP9 by highly metastatic colon carcinoma LuM1 cells, detected by zymography, was augmented 10-fold when cultured in medium supplemented with serum-free medium conditioned with LuM1 cells. Because the secretion of M(r) 60,000 gelatinase (MMP2), as well as total protein, by the same cells was not affected under these conditions, the augmentation appears specific for MMP9. The steady-state level of MMP9 mRNA was elevated in LuM1 cells cultured in the presence of the supernatant. The amount of the factor in the culture medium increased with time in culture, indicating that it was produced by the LuM1 cells. It was found to be heat stable but sensitive to trypsin digestion. Conditioned medium from poorly metastatic NM11 cells did not stimulate the secretion of gelatinases by NM11 cells, suggesting that autocrine stimulation of MMP9 secretion is a characteristic of metastatic cells. This factor could account for the augmented secretion of MMP9 by murine tumor cells with spontaneous metastatic potential to the lung.

Animals↗
PubMed1994

Tissue distribution of ERp61 and association of its increased expression with IgG production in hybridoma cells.

A protein of molecular weight 60 kDa was purified from the culture medium of a murine colon carcinoma cell line, colon26, and its partial amino-acid sequence determined. Extremely high homology was found with the deduced sequence from cDNA of rat ERp61, earlier found to be an endoplasmic reticulum (ER)-resident protein with redox activity and a similar structure to protein disulfide isomerase (PDI). Western blotting analysis showed that colon26 cells secrete a significant amount of ERp61 into culture medium, although most remains intracellular. The thiol:protein disulfide oxidoreductase activity of the purified mouse ERp61 was demonstrated by insulin-reduction assay. The ER location of the protein in fibroblasts was immunocytochemically confirmed by double staining for ERp61 and another ER-resident protein, PDI or Hsp47. Immunohistochemical studies of murine tissues showed a ubiquitous distribution of ERp61 in a wide variety of cell types. However, it was particularly abundant in plasma cells, mucus-secreting cells in various tissues, neuroendocrine cells including neurons, and follicular epithelia of thyroid gland that actively synthesize and secrete proteins containing cysteine residues. Furthermore, a high correlation was observed between intracellular amounts of ERp61 and immunoglobulin production by hybridoma cells. These results indicate that ERp61 may be involved in disulfide bond formation for such proteins.

Amino Acid Sequence↗
PubMed1994

Germ line mutations of the ret proto-oncogene in Japanese patients with multiple endocrine neoplasia type 2A and type 2B.

We investigated mutations of the ret proto-oncogene in Japanese patients with multiple endocrine neoplasia (MEN) type 2A and type 2B. DNAs from pheochromocytomas and/or medullary thyroid carcinomas (MTCs) of five MEN 2A and three MEN 2B patients were amplified by a polymerase chain reaction (PCR) and analyzed. Tumors of four MEN 2A patients had missense mutations in Cys 634 in the extracellular domain of the ret proto-oncogene. The same mutations were detected in normal tissues of the patients, indicating that the mutations had arisen in the germ line. Using a reverse transcriptase(RT)-PCR, both normal and mutant transcripts of the ret proto-oncogene were detected in a tumor of one patient with MEN 2A mutation. In addition, three MEN 2B patients examined had the same point mutation (ATG-->ACG) at codon 918 in the tyrosine kinase domain of the ret proto-oncogene. Since all mutations identified in this study generated new restriction enzyme sites or eliminated a restriction site, the mutant alleles of affected family members could be readily detected without sequencing.

Base Sequence↗
PubMed1994

Experimental in vivo and in vitro formation of type VI collagen periodic fibrils in chorionic villi of human placenta.

The distribution of type VI collagen in the chorionic villi of normal human term placenta was studied. Since 100 nm periodic fibrils (type VI collagen periodic fibrils) are known to form in the tendon, cornea and cultured fibroblasts by incubation with acidic ATP solution, we incubated the placental tissue with 20 mM ATP, fixed it with Karnovsky's fixative and examined under an electron microscope. Type VI collagen periodic fibrils widely occurred in the interstitial connective tissue, especially close to the basal lamina. By cryo-immunoelectron microscopy, labeling for collagen type VI was found in the area between the trophoblastic basal lamina and the endothelial basal lamina. Furthermore, we extracted type VI collagen from the human placenta and brought both extract and residues into ATP treatment. Periodic structure formation was rare in extracted preparation compared with residues. The results served to clarify the mechanism of fibril formation in the tissue.

Adenosine Triphosphate↗
PubMed1994

Bacteriological evaluation of a new air turbine handpiece for preventing cross-contamination in dental procedures.

An autoclavable air turbine handpiece, Air Flushing Clean System (AFCS) (Osada Electric Co., Ltd., Tokyo, Japan) was developed for use in dentistry with the objective of reducing cross-contamination. Its potential for bacterial contamination was investigated in vitro using two bacterial strains (Streptococcus mutants ATCC 25175 and Staphylococcus aureus FDA 209 P). In theory, this device should prevent cross-contamination of the internal water and air lines of the handpiece, by maintaining an internal positive pressure even after the turbine is stopped. In the present study, this AFCS device was found to reduce the bacterial contamination within the air turbine handpiece more effectively than the conventional handpiece used according to accepted protocol. The reduction of such contamination by the AFCS is in keeping with the recent objective of the American Dental Association to reduce cross-contamination during dental procedures.

Bacteriological Techniques↗
PubMed1993

Inhibition of ret tyrosine kinase activity by herbimycin A.

We examined the effect of herbimycin A, a potent inhibitor of tyrosine kinases, on NIH(ret) cells and TPC-1 papillary thyroid carcinoma cells, both of which express the active ret genes. Herbimycin A reversed the morphology of NIH(ret) cells to flat cells with a concomitant reassembly of microfilament bundles. On the other hand, it did not induce a significant change in cell shape of TPC-1 cells. When tyrosine kinase activities of the active ret gene products in herbimycin A-treated NIH(ret) and TPC-1 cells were examined in immunocomplex kinase assays, they drastically decreased in both cells as compared with untreated cells. In addition, herbimycin A strongly inhibited tyrosine phosphorylation of 40 kDa and 31 kDa proteins present in the immunoprecipitates of both cells, suggesting that these proteins could associate with the Ret proteins.

Actins↗
PubMed1993

Tyrosine kinase activity of the ret proto-oncogene products in vitro.

We investigated tyrosine kinase activity of the ret proto-oncogene products (proto-Ret proteins), using a cell lysate of NB-39-nu neuroblastoma cells. The 150 kDa and 170 kDa proto-Ret proteins immunoprecipitated with antibodies against their carboxy-terminal 20 amino acids were shown to be phosphorylated predominantly on tyrosine residues in immunocomplex kinase assay. The level of tyrosine phosphorylation of the 150 kDa proto-Ret protein was approximately 10-fold higher than that of the 170 kDa proto-Ret protein, although both proteins were expressed at similar levels in neuroblastoma cells. This result was confirmed by using a lysate of SK-N-MC human primitive neuroectodermal tumor cells transfected with the ret proto-oncogene. The kinase activity of proto-Ret proteins was significantly inhibited by antibodies against their kinase domain, indicating that these antibodies recognize crucial epitopes for the enzymatic activity. On the other hand, the proto-Ret proteins were not phosphorylated in vivo in NB-39-nu cells and SK-N-MC transfectants.

Amino Acids↗
PubMed1993

Irradiation effects on wound contraction using a connective tissue model.

To analyze irradiation effects on wound contraction, fibroblasts harvested from human oral mucosa were irradiated (single 2-, 4-, 6-, 8-, and 10-Gy exposures of x-rays). The irradiated fibroblasts were examined for growth ability, and they were cultured three-dimensionally in hydrated collagen gels. The irradiation inhibited growth of fibroblasts and contraction of collagen gels in a dose-dependent manner. In addition, inhibition depended on the duration after exposure. The organization of actin filaments of fibroblasts in this model was examined with fluorescent dye-conjugated phalloidin. Many elongated cell projections were formed in cells of the control group, but the cell projections were almost disrupted in the irradiated cells. X-ray irradiation is thus shown to inhibit wound contraction by affecting the organization of actin filaments in fibroblasts.

Actins↗
PubMed1993

Serious adverse effects induced by simultaneous administration of two nonsteroidal anti-inflammatory drugs.

We have described the case of a 58-year-old woman in whom acute hemolytic anemia, renal failure, and granulocytopenia developed after intake of mefenamic acid and diclofenac. Results of direct and indirect Coombs' tests were negative, but the lymphocyte transformation test was positive for these two nonsteroidal antiinflammatory drugs (NSAIDs). We suggest that the immune complex mechanism could have induced these adverse reactions. Although these drugs are very popular, simultaneous administration should be avoided because serious adverse effects can potentially occur.

Acute Kidney Injury↗
PubMed1993

Chromosomal mapping of genetic locus associated with thymus-size enlargement in BUF/Mna rats.

The thymoma-prone rat of the BUF/Mna strain is a useful model for human thymoma. In this strain thymoma development is regulated by a single autosomal susceptible gene, Tsr-1. At pre-thymoma age, BUF/Mna rats have extremely large thymuses, when compared to those of other strains of rats. Genetic studies in crosses between BUF/Mna rats with large thymuses and WKY/NCrj rats with small thymuses suggested the presence of a major autosomal gene, Ten-1, which contributes to thymus enlargement in a backcross population. Linkage studies between Ten-1 and microsatellite markers in backcross rats of (WKY/NCrj x BUF/Mna)F1 x BUF/Mna have led to the localization of Ten-1 in chromosome 1. This result may provide an approach to clone Tsr-1, which could be allelic to Ten-1.

Animals↗
PubMed1993

[UV-microspectrophotometric and flow cytometric analysis of the same samples using DAPI/HP staining].

A simple one-step double staining with DAPI and hematoporphyrin (HP) was used for UV-microspectrophotometric (UV-MSPM) and flow cytometry (FCM) analysis of the same samples. The specimens analyzed included fresh biopsy and/or surgical materials, trimmed 50 microns-thick paraffin sections and smears (with the latter not available for FCM). We provided the special technology for preserving the cytoplasm as far as possible to permit measurement of cell size and N/C ratio. DAPI indicates DNA content under 365 nm and HP of total protein content under 670 nm UV-MSPM. The DAPI can measure the nuclear size and the latter the cell size. DAPI/HP staining yielded much more accurate measurements than staining with FITC and PI. The use of both MSPM and FCM with cell sorting on the same samples is very helpful in cytology and histopathology for evaluating and differentiating borderline lesions and grade of malignancy, as well as oncostatic effectivity. Our goal is to combine this technology with the automated cytologic screening system CYBEST, which was developed by Tanaka et al, based on a morphometric device.

Adenocarcinoma↗
PubMed1993

Expression of proto-oncogenes and tumor suppressor genes in in vitro cell lines derived from a thymus, thymoma, and malignant thymoma of rats.

To analyze the processes of the development of thymoma and malignant thymoma from normal thymic epithelial cells, we have examined the expression of 15 proto-oncogenes and tumor suppressor genes in seven in vitro epithelial cell lines established from a normal thymus (TuD1-1, TuD1-3, and TuD1-5), thymoma (TaD1-3 and TaD1-8), and malignant thymoma (MTHC-1 and MTHC-3) of rats. Northern blot analysis indicated that most of these genes examined were transcribed at similar levels. However, higher levels of transcription of epidermal growth factor receptor (EGFR) were observed in TuD1-1, TuD1-3, TuD1-5, TaD1-3, and TaD1-8 cells than in MTHC-1 and MTHC-3 cells. Conversely, four of the former five cell lines showed no TGF-beta transcription while the latter two cell lines had high levels of its expression. In addition, c-fos proto-oncogene was highly expressed in TuD1-5 cells, which showed the fastest growth rate among the seven cell lines. These results denote that some molecular changes in the regulation of gene expression occurred in the processes of malignant transformation of thymic epithelial cells.

Animals↗
PubMed1993

Checkup interval and cancers in automated multiphasic health testing and services.

The purpose of this study was to disclose which types of cancer and how many persons with cancer were detected among the AMHTS examinees of our AMHTS center by using the hospital information retrieval system, and to study the relationship between cancer and the number of examinees, checkup intervals, and frequency in AMHTS. The examinees who had checkups more than twice were divided into three groups based on their checkup intervals: within one year, one to two years, and over two years. The relationship between cancer ratios and checkup intervals was evaluated in each group of examinees. In those having checkups within one year and from one to two years the cancer rate was 2.9 patients per 1,000 persons. However, in those having checkups after a two-year period or longer, the cancer rate was 4.3, clearly greater than the rate of the other two groups.

Adult↗
PubMed1993

Characterization of the ret proto-oncogene products expressed in mouse L cells.

The ret proto-oncogene (proto-ret) encodes a receptor type tyrosine kinase with a cadherin-related sequence in the extracellular domain. To investigate whether the proto-Ret protein functions as a cell adhesion molecule like cadherins, we transfected the human proto-ret gene fused to the SV40 promoter or cytomegalovirus (CMV) promoter into mouse L cells in which cadherins are not expressed. Three transfectants with high levels of expression of the proto-Ret proteins were obtained. The proto-Ret proteins were expressed as 150 kDa and 170 kDa glycoproteins in transfectants as observed in human neuroblastoma cells. Cell fractionation experiments revealed that the 170 kDa protein but not the 150 kDa protein was detected predominantly in the plasma membrane fraction, indicating that the 170 kDa protein represents the mature glycosylated form of the proto-Ret protein present on the cell surface. Both 150 kDa and 170 kDa proto-Ret proteins showed tyrosine kinase activity in immunocomplex kinase assay. It is known that cadherins have Ca(2+)-dependent homophilic binding activity and are resistant to trypsinization in the presence of Ca2+. When L cells expressing the proto-Ret proteins were treated with trypsin in the presence of Ca2+, the 170 kDa protein was resistant to its digestion. On the other hand, it was completely digested in the presence of EGTA, suggesting the possibility that the proto-Ret protein interacts with Ca2+ like cadherins. However, the transfectants did not show clear adhesive properties in cell aggregation assays.

Animals↗
PubMed1992

RFP is a DNA binding protein associated with the nuclear matrix.

We reported that the RFP gene encodes a protein with putative zinc finger domains and was involved in the activation of the ret proto-oncogene. To further characterize the RFP protein, we developed a polyclonal antibody against the product synthesized from a fragment of the RFP cDNA expressed in Escherichia coli. Western blot analysis showed that RFP was identified as a 58 kDa protein in cell lysates from four human and rodent cell lines and from mouse testis. In addition, a unique 68 kDa protein was detected in the testis. Using AH7974 (rat ascites hepatoma) and Raji (human Burkitt lymphoma) cells, we demonstrated strong association of RFP with the nuclear matrix. Furthermore, RFP solubilized from the nuclear matrix had DNA-binding activity although it appears to bind more preferentially to double-stranded DNA than to single-stranded DNA. These results thus suggest that RFP may play a role in molecular processes which occur in the nuclear matrix.

Amino Acid Sequence↗