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Biomedical subjects

M Miyazawa

Publications and source records attributed to M Miyazawa.

At least 19 recordsLinked to original sources
PubMed1997

Antimutagenic effect of resveratrol against Trp-P-1.

The methanol extract of Yucca schidigera (YE) showed a suppressive effect on umu gene expression of the SOS response induced by 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) in Salmonella typhimurium TA1535/pSK1002. The suppressive effect of YE was also observed for 2-aminoanthracene and activated Trp-P-1, without a significant effect on bacterial growth. The extract exhibited a weak suppressive effect on SOS-induction by N-methyl-N'-nitro-N-nitrosoguanidine, but not by furylfuramide or 4-nitroquinoline-1-oxide. The antimutagenic activity of YE against Trp-P-1 was demonstrated by Ames assay using Salmonella typhimurium TA98. Isolation and purification of the active component of YE was carried out using SiO2 column chromatography, and 275 mg of antimutagenic compound was isolated from 2.5 kg of dried chips of yucca roots and branches. The compound was identified as 3,4',5-trihydroxystilbene (THS). The SOS suppression and antimutagenicity of THS against Trp-P-1 was determined by umu test and Ames test.

4-Nitroquinoline-1-oxide↗
PubMed1997

[Primary cutaneous lymphoma--mycosis fungoides].

Malignant lymphoma of the skin is a type of extranodal lymphoma with a benign prognosis, in which the main organ involved is the skin. Some 80-90% of the cases in Japan show a T-cell phenotype. Mycosis fungoides and Sézary syndrome are common T-cell lymphomas of the skin. The tumor cells of mycosis fungoides, small and medium-sized cells with cerebriform nuclei, are detected in an epidermo-dermo junction. The tumor cells show CD3, CD4 and CLA, (cutaneous lymphocyte associated antigen) positivity. Various forms of topical therapy, such as topical steroid, photochemotherapy (PUVA), and interferons, have been indicated for the good-risk group (stages I A, I B and II A). Electron-beam irradiation, various chemotherapy, such as low-dose etoposide, low-dose MTX and CPT-11 and deoxy coformycin (DCF) plus IFNs, have been indicated for intermediate-risk group (stage II B, III and IV A). BRMs plus low-dose etoposide, electron-beam irradiation and a multiagent combination chemotherapy, such as MACOP-B, M-BACOD or ProMACE-CytaBOM, have been indicated for the high-risk group (stages IV A and IV B). Cutaneous B cell lymphoma (CBCL) can be diagnosed using a molecular biological assay. The tumor cells of CBCL do not express T-cell antigens such as CD2, CD3 and CD43 and show B-cell antigens such as sIg, CD19, CD20 and CD22. Electron-beam irradiation has been indicated for early-stage CBCL (stages I and II). An effective multiagent combination chemotherapy, such as MACOP-B, M-BACOD or ProMACE-CytaBOM, is required for patients with advanced stage CBCL (stages III and IV).

Antigens, CD↗
PubMed1996

O-demethylation of 7,7'-epoxylignans by Aspergillus niger.

Biotransformation of the 7,7'-epoxylignans, (+)-veraguensin, (+)-galbelgin and galgravin by Aspergillus niger has been investigated. These lignans were converted to their corresponding 4,4'-O-demethyl derivatives, (+)-verrucosin, (+)-fragransin A2 and nectandrin B.

Aspergillus niger↗
PubMed1996

Is postoperative radiotherapy for thymoma effective?

OBJECTIVE: The authors determined the effect of postoperative mediastinal irradiation in preventing local and pleural recurrence of thymoma. SUMMARY BACKGROUND DATA: The role of mediastinal irradiation after incomplete resection or biopsy of an invasive thymoma is well established. However, routine use of adjuvant mediastinal irradiation for patients with thymoma after complete resection remains controversial. METHODS: During the 19-year period from 1973 to 1992, operations were performed on 89 patients with thymoma. Of these 89 patients, 80 patients who underwent gross complete tumor resection including adjacent tissues that appeared to be invaded by tumor were selected for this study. The effects of postoperative mediastinal irradiation on the recurrence rate of thymoma were analyzed according to histologic type, clinical stage, and whether adhesions to or invasion of the pleura or pericardium were present. RESULTS: Recurrence of thymoma was observed in 13 of 80 (16.3%) patients. No recurrence was observed in 23 patients with noninvasive thymoma. In patients with invasive thymoma whose tumor was macroscopically adherent to the pleura but not microscopically invasive (p1), recurrence was observed in 4 of 11 patients (36.4%) when mediastinal irradiation was not performed, but in none of 10 patients who received mediastinal irradiation. However, in patients with microscopic pleural invasion (p2), a high recurrence rate was observed with mediastinal irradiation (40%, 6/15 patients) or without mediastinal irradiation (30%, 3/10 patients). Postoperative mediastinal irradiation for patients with microscopical invasion to pericardium (c2) did not decrease the recurrence rate. Analysis of the mode of recurrence showed that mediastinal irradiation may have been effective in preventing local recurrence, but it did not control the pleural dissemination that was observed in 12 of 13 recurrent cases. CONCLUSIONS: Mediastinal irradiation is not necessary for patients with noninvasive thymoma. In patients with invasive thymoma, postoperative mediastinal irradiation is effective in preventing recurrence in patients with p1 thymoma, but not in patients with p2 or c2 tumors. Further adjuvant therapy should be performed to supplement mediastinal irradiation in patients with p2 or c2 thymoma, even after complete resection.

Adolescent↗
PubMed1996

Characterization of novel monoclonal antibodies raised against formalin-fixed, paraffin-embedded human ameloblastoma.

To obtain monoclonal antibodies reactive with odontogenic but not other types of epithelium, mice were immunized with homogenates of fixed ameloblastoma tissues, and monoclonal antibodies Y4 and M11 were produced. Y4 reacted immunohistochemically with odontogenic epithelial components but not with those of squamous differentiation, while M11 reacted with odontogenic epithelial components and a part of keratotic epithelial tissues. Immunoglobulin isotypes of both antibodies were IgM as determined by Ouchterlony immunodiffusion and enzyme-linked immunosorbent assays. Western blotting revealed that the antigen recognized by Y4 had a molecular mass of approximately 66 kDa; however, the antigen reactive with M11 was not identified by Western blotting in spite of various attempts in changing reaction conditions. These antibodies may be beneficial to histological analyses of odontogenic tissues and their related lesions.

Ameloblastoma↗
PubMed1996

The effect of Helicobacter pylori on gastric acid secretion by isolated parietal cells from a guinea pig. Association with production of vacuolating toxin by H. pylori.

BACKGROUND: One of the features of Helicobacter pylori infection in the human stomach seems to be disordered gastric acid secretion. The effect of vacuolating toxin (VT) produced by H. pylori on gastric acid secretion was examined. METHODS: VT(+)(toxigenic) and VT(-)(nontoxigenic) strains of H. pylori were cultured in brucella broth. The culture supernatant was added to isolated parietal cells, and acid secretion and intracellular adenosine 3'5'-cyclic phosphate (cAMP) and Ca2+ levels were measured with the 14C-aminopyrine (14C-AP) method, with 125I radioimmunoassay (RIA), and with the fura-2 fluorescence method, respectively. RESULTS: In the VT(+) strain a considerable inhibitory effect on 14C-AP accumulation was observed. However, the VT(-) strain had no significant effect on intracellular c-AMP and Ca2+. CONCLUSIONS: The VT(+) strain of H. pylori has an inhibitory effect on gastric acid secretion, whereas the VT(-) strain does not. This inhibitory effect was not associated with the response of second messengers. It is speculated that VT produced by H. pylori has a direct action on H(+)-K+ adenosine triphosphatase in parietal cells.

Animals↗
PubMed1996

Immunophenotypic characterization of Epstein-Barr virus-associated gastric carcinoma: massive infiltration by proliferating CD8+ T-lymphocytes.

A subset of gastric carcinoma carries Epstein-Barr virus (EBV). The immunophenotypic features of EBV-associated (EBV+) gastric carcinoma, which we have analyzed using 25 EBV+ cases, remain unclear. Frozen tissue samples were stained with antibodies to various immune cell markers. To evaluate the proliferative activity of CD8+ cells, we performed CD8/Ki-67 double staining on paraffin-embedded sections. The results were compared with those in EBV-negative (EBV-) gastric carcinomas. All EBV+ and EBV- gastric carcinoma cells expressed major histocompatibility complex class I, whereas major histocompatibility complex class II expression in tumor cells was more prominent in EBV+ cases. Intercellular adhesion molecule-1 and Fas/APO-1 expression was largely restricted to EBV+ cases. The lymphocytes that infiltrated EBV+ tumor nests were predominantly CD8+ T cells, many of which expressed perforin. Immunoelectron microscopy confirmed a close cell to cell contact between these CD8+ cells and carcinoma cells. CD8+ cells were CD11a+ and CD11b- by flow cytometry performed in one case. The labeling index of Ki-67, the proliferation-associated antigen, in CD8+ cells was 4 times higher in EBV+ cases than in EBV- cases. Our data suggest that these CD8+ cells, which bear a cytotoxic phenotype, are actively proliferating in close contact with EBV+ tumor cells and that the specificity of the CD8+ cells may be directed to EBV and/or cellular antigens expressed by the tumor. This is consistent with a generally favorable prognosis of EBV+ gastric carcinoma. Because the observed T-cell infiltration is insufficient to eradicate the tumor cells, certain immunosuppressive factors were speculated to allow the essentially immunogenic carcinoma cells to establish a macroscopic lesion.

Antigens, CD↗
PubMed1996

[Postoperative early complication of primary lung cancer].

We analyzed postoperative early complications of primary lung cancer in 321 cases during 1982 to 1993 in our hospital, and assessed the prevention and the treatment against these complications. In order of frequency the complications are, paroxymal supraventricular tachcarida (10.6%), atelectasis due to sputum (6.9%), pulmonary fistula for more than seven days (4.7%), hoarseness of voice due to recurrent nerve palsy (4.0%), chylothorax (2.5%), gastrointestinal tract complications (2.2%), reoperation due to massive bleeding (1.2%), wound dehiscence (0.9%), bronchial fistula (0.6%), rupture of ascending aorta (0.3%) and myocardial infarction (0.3%). The two cases of bronchial fistula after pneumonectomy, and one of myocardial infarction after lobectomy through the median approach died of early complications. The operative indication for primary lung cancer is extended to the patients with higher age and lower pulmonary function; so we should be careful for the pre and postoperative prevention and the rapid and appropriate treatment against these postoperative early complications.

Adult↗
PubMed1996

[A case of carcinoid tumor of left superior trunk treated by sleeve upper lobectomy].

A case of bronchial carcinoid was reported. A 39-year-old male was suffered from recurrent pneumonia. Bronchofiberscopy revealed a polipoid tumor nearly obstructing left superior bronchial trunk. CT scan showed a round tumor about 1 cm in diameter. Resection of the tumor was carried out by sleeve upper lobe loectomy. Histological diagnosis was typical carcinoid, and there was no lymph node matastasis. Postoperative course was uneventful. Granulation and stenosis were not observed at the part of anastomosis.

Adult↗
PubMed1996

[Standard range of peak expiratory flow in normal, healthy Japanese subjects].

The measurement and analysis of the standard range of peak expiratory flow (PEF) in normal, healthy Japanese is necessary at any cost to facilitate bringing the Japanese Guidelines for Bronchial Asthma smoothly into effect. In a study as part of The Bronchial Asthma Group of the Comprehensive Research Project (Terumasa Miyamoto, Chairman of the Planning and Evaluation Committee) under the auspices of the Ministry of Health and Welfare, we measured PEF in 2,785 healthy Japanese volunteers (1,407 males aged 15-84 years and 1,738 females aged 15-80 years) who had no history of smoking, respiratory and/or thoracic diseases, or wheezing with four different peak flow meters (e.g., mini-Wright, Assess, Personal Best and Vitalograph). As a result of comparing PEF measured by the four meters in the same subjects over a short interval of time, we noted significant differences on analysis of variance. Accordingly, the equation for prediction should account for variables in gender and the type of peak flow meter used. A comparison of cubic equations for prediction suggests that the PEF of both Japanese men and women is similar to that of the British but is different from that of the Chinese.

Adolescent↗
PubMed1996

Proliferation of macrophage-lineage cells in the bone marrow, severe thymic atrophy, and extramedullary hematopoiesis of possible donor origin in an autopsy case of post-transplantation graft-versus-host disease.

A case of proliferation of CD68-positive macrophage-lineage cells in the bone marrow accompanied by severe thymic atrophy associated with graft-versus-host disease (GVHD) in a boy given allogeneic bone marrow transplantation (BMT) is reported. A 7-year-old boy was treated for posthepatitic severe aplastic anemia by BMT from his HLA-identical, mixed lymphocyte reaction-negative sister. After the transplantation his peripheral blood group converted to the donor type. However, the patient suffered from acute and chronic GVHD and slowly progressive anemia, and he died of multiple organ failure 21 months after BMT. At the autopsy diffuse and monotonous proliferation of CD68-positive macrophage-lineage cells was found to be replacing the blood-forming cells in the bone marrow. The thymus was almost empty of T lymphocytes, and remaining strands of extremely atrophic epithelial cells showed focal cystic change. Extramedullary hematopoiesis was found in the spleen. Analyses of microsatellite markers suggested the hematopoietic cells in the spleen to be of donor origin.

Atrophy↗
PubMed1996

[Congenital esophago-bronchial fistula in the adult: a case report].

A 45-year-old female with congenital esophago-bronchial fistula was reported. She had suffered from common cold and recurrent bouts of coughing during meals since infancy. An esophago-bronchial fistula was detected by esophagography accidentally. The fistula was connected with right lower lobe bronchus (B6). CT scan showed the cystic change of the right lower lobe. The fistula was surgically removed and right lower lobe lobectomy was carried out. The adhesion of the lower lobe to the chest wall was recognized, but there were no inflammatory signs around the fistula. The isolation of the fistula was very easy. The postoperative course was uneventful.

Bronchial Fistula↗
PubMed1995

Immunization with a single T helper cell epitope abrogates Friend virus-induced early erythroid proliferation and prevents late leukemia development.

Synthetic peptide vaccines containing a single Th cell epitope identified in the gp70 envelope glycoprotein of Friend murine leukemia helper virus induced potent protective immunity against Friend virus infection. H-2a/b mice immunized by a single s.c. injection of the CFA emulsion containing a peptide that represented the N-terminal gp70 epitope recovered slowly from initial development of splenomegaly, and most did not develop late leukemia, whereas most of the control mice given an injection of CFA alone showed sustained leukemic splenomegaly after the challenge with Friend virus. The mice of the same genetic background immunized with the C-terminal Th cell epitope by a single injection of a separate synthetic peptide eliminated virus-producing cells from the spleen within 12 days after inoculation of Friend virus complex, and did not develop early splenomegaly or polycythemia. H-2a/a mice were not protected by immunization with either one of the two synthetic peptides. Earlier production and more rapid class switching of virus-neutralizing Abs were observed in H-2a/b mice immunized with the peptide vaccines after the challenge with Friend virus, compared with the responses of the control mice. Detailed kinetic and immunohistopathologic analyses suggested that Th cells might be directly involved in the growth inhibition and elimination of virus-infected erythroid precursor cells.

Amino Acid Sequence↗
PubMed1995

Biotransformation of an acyclic neolignan in rats.

The biotransformation of an acyclic neolignan, (+)-erythro-(4,7-dihydroxy-3-methoxy-1'-allyl-3',5'-dimethoxy)-8-O-4' neolignan, in rats has been investigated. After administration of (+)-erythro-(4,7-dihydroxy-3-methoxy-1'-allyl-3',5'-dimethoxy)-8-O-4'-++ +neolignan to rat by intraperitoneal injection, urine and faeces were collected. A small amount of (+)-erythro-(4,7-dihydroxy-3-methoxy-1'-allyl-3',5'- dimethoxy)-8-O-4'-neolignan and its metabolic product were obtained from an ethyl acetate extract of the urine, and the largest amount of the same metabolic product was obtained from a dichloromethane extract of the faeces. The sole metabolic product was identified as (+)-(4-hydroxy-3-methoxy-1'-allyl-3',5'-dimethoxy)-8-O-4'-neolignan++ + by spectroscopic methods. Furthermore, biotransformation of (+)-erythro-(4,7-dihydro-3-methoxy-1'-allyl-3',5'- dimethoxy)-8-O-4'-neolignan by intestinal bacteria in rat faeces was also investigated in vitro. Consequently, (+)-erythro-(4,7-dihydroxy-3-methoxy-1'-allyl-3',5'-dimethoxy)-8-O-4'-++ +neolignan was reduced to the same metabolic product and no other metabolic products were produced. These results suggested that intestinal bacteria were concerned in the specific dehydroxylation of (+)-erythro-(4,7-dihydroxy-3-methoxy-1'-allyl-3',5'-dimethoxy)-8-O-4'-++ +neolignan in rats.

Animals↗
PubMed1995

Low expression of adhesion molecules in a case of cutaneous T-cell lymphoma.

A case of cutaneous T-cell lymphoma (CTCL) with low expression of the adhesion molecules lymphocyte function-associated antigen-1 (LFA-1), intercellular adhesion molecule-1 (ICAM-1), and very late antigen-4 (VLA-4) is described. The patient was a 90-year-old man with red round homogeneous tumors on his scalp, trunk, and extremities. He had no history of definite erythema or plaque stage. A biopsy sample taken from a tumor revealed massive infiltration of atypical lymphocytes in the reticular dermis and subcutis with a definite clear zone. The atypical lymphocytes were medium-sized with slightly convoluted nuclei. Immunohistochemically, the infiltrates showed the phenotype of so-called memory T cells. On the basis of these features, the case was diagnosed as CTCL. Expression of LFA-1, ICAM-1 and VLA-4 on the infiltrates was 9%, 13% and 11%, respectively, which is much lower than that in classic mycosis fungoides. This finding suggests that loss of these adhesion molecules may contribute to loss of epidermotropism in the advanced stage of CTCL.

Aged↗
PubMed1995

A single retroviral gag precursor signal peptide recognized by FBL-3 tumor-specific cytotoxic T lymphocytes.

Several dominant T-cell receptors of cytotoxic T-lymphocyte (CTL) clones specific for FBL-3 tumor antigen were clonally amplified in mixed lymphocyte tumor cell cultures derived from an individual immune mouse. Every CTL clone analyzed had a common specificity for a single epitope in the precursor to cell membrane-associated nonstructural gag-encoded protein, Pr75gag, which can be minimally identified by nine amino acid residues, SIVLCCLCL. This epitope is located within the hydrophobic signal sequence motif that mediates translocation of the protein into the endoplasmic reticulum. These novel observations suggest that expression of Pr75gag in FBL-3 tumor cells led to the amplification of CTLs which recognize the signal sequence of the nonstructural gag-encoded glycoprotein precursor.

Amino Acid Sequence↗