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Biomedical subjects

G Tamura

Publications and source records attributed to G Tamura.

At least 145 records · Page 8Linked to original sources

Adenomyoepithelioma (myoepithelioma) of the breast in a male.

Adenomyoepithelioma (myoepithelioma) of the breast in a 47-year-old man is reported. The tumor consisted of a prominent proliferation of spindle cells surrounding mammary ducts. Immunohistochemical and electron microscopic observations confirmed the myoepithelial origin of these spindle cells. This is the first report of an adenomyoepithelioma of the breast that developed in a male.

Breast Neoplasms↗

The effect of an oral leukotriene antagonist, ONO-1078, on allergen-induced immediate bronchoconstriction in asthmatic subjects.

BACKGROUND: Cysteinyl leukotrienes are potent contractile agonists for airway smooth muscle. To examine the relative role of cysteinyl leukotrienes in immediate airway obstruction in human subjects with asthma after allergen challenge, we investigated the effect of ONO-1078, a potent receptor antagonist of cysteinyl leukotrienes, on the response. METHODS: ONO-1078 and an inactive placebo, in 150-mg capsule form, were administered every 12 hours for 1 week, in a double-blind, cross-over fashion. To examine the effect on the early part of the response, total respiratory resistance (Rrs) was continuously evaluated for 10 minutes after the start of a 1-minute exposure to an appropriate concentration of allergen. Rrs and FEV1.0 were estimated every 10 minutes for 60 minutes after the exposure. RESULTS: ONO-1078 significantly reduced percent changes in Rrs and FEV1.0 from 20 to 60 minutes after the exposure, as well as percent maximum changes in these indices, although the treatment did not alter the time from the start of allergen exposure to the beginning of elevation of Rrs, the time from the start to the point at which total respiratory conductance decreased by 35% from its baseline value, or percent changes in Rrs or FEV1.0 10 minutes after the exposure. CONCLUSIONS: Therefore, we conclude that cysteinyl leukotrienes primarily mediate a later part of immediate airway obstruction after allergen exposure.

Administration, Oral↗

Primary gastric carcinoma cells frequently lose heterozygosity at the APC and MCC genetic loci.

Loss of heterozygosity (LOH) at APC and MCC gene loci (both mapped to 5q21) was investigated in 24 surgical specimens of primary gastric carcinomas using the polymerase chain reaction after tumor cell enrichment by cell sorting based on differences in DNA content. LOH at APC and/or MCC was detected in 87% (13/15) of the cases; at the APC in 86% (12/14) and at the MCC locus in 100% (7/7). LOH at the APC locus was always accompanied by LOH at the MCC locus. LOH at the APC and/or MCC was found in both differentiated and undifferentiated types in both early and advanced stages of gastric carcinoma. Thus, LOH at APC and/or MCC is considered to be one of the most prevalent genetic alterations in human gastric carcinoma and occurs at an early stage of the carcinogenesis.

Base Sequence↗

Mutations of the p53 gene in carcinomas of the urinary system.

Deletion of p53, which is an anti-oncogene located on chromosome 17p, was reported to be present at a high incidence in tumor cells of colorectal carcinoma, as well as osteosarcoma of the familial cancer syndrome. Mutations of the p53 gene were investigated in 59 surgical specimens of primary carcinomas of the urinary system from 57 patients, using the polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis. The PCR products were sequenced using the dideoxy chain termination method or the DNA sequencer. The tumors examined were 20 transitional cell carcinomas (TCC) and 39 renal cell carcinomas (RCC). Mutations of the p53 gene were detected in 20.0% (4/20) of TCC and were present in 16.7% (1/6) of the tumors invading the muscular layer. In two patients with simultaneous double bladder TCC, the mutations were found only in the larger tumors. In RCC, mutations were detected in 7.7% (3/39) of patients. No significant correlation between the presence of the mutation and the clinicopathologic parameters was found in RCC except that the three tumors with p53 gene mutations were clear cell carcinomas. These results suggest that p53 gene mutations play a possible role in both carcinogenesis and progression of TCC, but the p53 gene mutations may not be significant in development of RCC.

Aged↗

[Effect of AS-35 aerosol on bronchoconstriction induced by specific antigens in macacus rhesus monkeys].

In a previous in vitro study, 9-[(4-acetyl-3-hydroxy-2-n-propylphenoxy) methyl]-3-(1H-tetrazol-5-yl)-4H- pyrido[1,2-a]pyrimidin-4-one (AS-35) was shown to have an inhibitory effect on antigen-induced mediator release and an antagonistic effect on leukotriene C4 and D4 receptors. In the present study, therefore, we investigated the effect of AS-35 aerosol on allergen-induced bronchoconstriction, using 6 female Macacus rhesus monkeys sensitized with DNP-Ascaris extracts (DNP-As). After treatment with an inactive placebo, inhalation challenge with DNP-As increased total lung resistance and decreased dynamic lung compliance dose-dependently 1 week after sensitization with DNP-As. Treatment with AS-35 aerosol, however, significantly inhibited allergen-induced bronchoconstriction dose-dependently 2 weeks after the sensitization. The inhibitory effect was about ten times more potent than that of DSCG. Because we confirmed that DNP-As evoked almost the same bronchoconstriction 1 and 2 weeks after sensitization and also that AS-35 did not inhibit histamine-induced bronchoconstriction at all, we inferred that AS-35 diminished allergen-induced bronchoconstriction by inhibiting allergen-induced mediator release from the cells in the airway.

Aerosols↗

[Fat necrosis arising in the perinerhrium].

The patient was a 74-year-old woman. During the investigation for abdominal pain, a mass lesion was detected adjacent to the left kidney using ultrasound. The left radical nephrectomy was performed under a clinical diagnosis of liposarcoma. Histological examination revealed fat necrosis with hemorrhage arising in the perinephrium. No tumor cells were confirmed microscopically. We reviewed the literature, but there found, no case reports of fat necrosis arising in the perinephrium, except for reports in rats or cows.

Aged↗

[Induction of granule release by intracellular application of Ca and GTP gamma S in human eosinophils].

The roles of Ca and G proteins in granule release from human eosinophils were examined using a patch-clamp technique in single cells. The morphological changes and the release of eosinophil peroxidase (EPO) from single cells were simultaneously observed. The intracellular application of Ca, and GTP-gamma-S induced fusion of EPO containing granules with the surface membrane which was associated with a marked increase in membrane capacitance. Ca alone caused a rapid granule release at an early stage of cell dialysis, but most granules still remained in a cluster. GTP-gamma-S alone caused a gradual degranulation. Northern blot analysis revealed the definite expression of smg p21 mRNA with no appreciable expression of smg p25A in human eosinophils.

Calcium↗

Association of oriC region of Escherichia coli chromosome with outer membrane: effects of culture condition.

We isolated complexes containing oriC region DNA and outer membrane, named origin complex heavy and origin complex light, from the cells of Escherichia coli cultured in media with poor or rich of nutrients, and found the different nature of association between origin DNA and outer membrane. The ratio of origin complex light to origin complex heavy prepared from the cells cultured in rich media was lower than that of those from minimal medium culture. Outer membrane preparations from the cells grown in nutritious media had high abilities of association with origin complex light in the presence of magnesium. These results indicated that the number of binding sites on outer membrane with origin region DNA increase, or the binding between outer membrane and origin region DNA become more rigid, when cells grow faster and DNA replication initiate more frequently in a nutritious medium.

Binding Sites↗

Prognostic assessment of superficial squamous cell carcinoma of the esophagus using karyometric analysis and nucleolar organizer regions.

To investigate prognostic values for squamous cell carcinoma, we measured nuclear area (NA), nuclear shape factor (NSF), DNA content and mean number of nucleolar organizer regions (NOR), using formalin-fixed, paraffin-embedded tissue sections from 39 patients with superficial squamous cell carcinoma of the esophagus. NA and DNA content were significantly higher in patients with lymph node metastasis than in those without metastasis. NA and the NOR number were also significantly higher in patients with recurrence than in those surviving for more than 3 years without recurrence. To determine the optimal combination of these parameters for prognostic assessment, we used a stepwise discriminant analysis to obtain two linear discriminant functions. One (f = 0.331 x NA + 6.64 x NSF + 9.85) gave an accuracy of 87.2% in predicting lymph node metastasis, and the other (f = -0.071 x NA - 2.34 x NOR + 13.0) yielded an overall accuracy of 88.9% in classifying patients into two groups with a better and worse prognosis. These results suggest that karyometric analysis and determination of the NOR number are useful for the prediction of disease outcome in patients with superficial squamous cell carcinoma of the esophagus.

Aged↗

High level expression of the synthetic human lysozyme gene in Aspergillus oryzae.

Aspergillus oryzae was transformed with a synthetic gene consisting of a chicken lysozyme signal sequence and a mature human lysozyme (HLY) sequence. The transformants secreted active HLY (about 1.2 mg/l) when the HLY gene was expressed under the control of the Taka-amylase A gene (amyB) promoter. Western blot analysis suggested that the secreted protein was immunoreactive with anti-human lysozyme antibody and the signal peptide was correctly cleavaged off in the A. oryzae transformants. The transcriptional level of the HLY gene was investigated by Northern blot analysis using a probe that was equivalently specific to both the HLY gene and the amyB gene. The HLY gene was expressed at a higher level compared with the amyB gene because of its multi-copy integration. The efficient transcription of the HLY gene suggested that A. oryzae is a promising host for production of heterologous proteins from higher eukaryotes.

Amylases↗

Functional elements of the promoter region of the Aspergillus oryzae glaA gene encoding glucoamylase.

Analysis was made of the promoter region of the Aspergillus oryzae glaA gene encoding glucoamylase. Northern blots using a glucoamylase cDNA as a probe indicated that the amount of mRNA corresponding to the glaA gene increased when expression was induced by starch or maltose. The promoter region of the glaA gene was fused to the Escherichia coli uidA gene, encoding beta-glucuronidase (GUS), and the resultant plasmid was introduced into A. oryzae. Expression of GUS protein in the A. oryzae transformants was induced by maltose, indicating that the glaA-GUS gene was regulated at the level of transcription in the presence of maltose. The nucleotide sequence 1.1 kb upstream of the glaA coding region was determined. A comparison of the nucleotide sequence of the A. oryzae glaA promoter with those of A. oryzae amyB, encoding alpha-amylase, and A. niger glaA showed two regions with similar sequences. Deletion and site-specific mutation analysis of these homologous regions indicated that both are essential for direct high-level expression when grown on maltose.

Aspergillus niger↗

Induction of granule release by intracellular application of calcium and guanosine-5'-O-(3-thiotriphosphate) in human eosinophils.

The roles of Ca and G proteins in granule release from human eosinophils were examined by use of a patch-clamp technique in single cells. The morphologic changes and the release of eosinophil peroxidase (EPO) from single cells were simultaneously observed. In addition, the expression of small molecular weight guanine nucleotide binding protein (small G protein) mRNA (smg p25A [rab 3] and smg p21 [rab 1]) was investigated. The intracellular application of Ca, 10 mumol/L, and guanosine-5'-O-(3-thiotriphosphate) (GTP-gamma-S), 100 mumol/L, induced fusion of EPO containing granules with the surface membrane, which was associated with a marked increase in membrane capacitance. Ca alone caused a rapid granule release at an early stage of cell dialysis, but most granules still remained in a cluster. GTP-gamma-S alone caused a gradual degranulation. Northern blot analysis revealed the definite expression of smg p21 mRNA with no appreciable expression of smg p25A. These results provide direct evidence of granule fusion by intracellular application of Ca and GTP-gamma-S. In addition, Ca dependent proteins and G proteins act cooperatively in granule release, and these proteins likely regulate the different processes of degranulation. Furthermore, a protein, encoded by smg p21, may be involved in the granule release process in human eosinophils.

Calcium↗

Infrequent mutation of p53 gene in human renal cell carcinoma detected by polymerase chain reaction single-strand conformation polymorphism analysis.

Mutation of the p53 gene, which plays an important role in the genesis of diverse human cancers, was investigated in 23 surgical specimens of human renal cell carcinoma using the polymerase chain reaction single-strand conformation polymorphism method of analysis. Only one of the 23 tumors (4.3%) carried a mutated p53 gene, which was present in exons 7-8. Direct DNA sequencing confirmed a point mutation at codon 276 (GCC to CCC) resulting in a substitution of alanine for proline. No specific clinicopathological characteristics were observed in the case with the p53 gene mutation in human renal cell carcinoma. These observations suggest that mutation of the p53 gene is rare and thus does not contribute significantly to the genesis of this tumor.

Amino Acid Sequence↗

p53 gene mutations in esophageal cancer detected by polymerase chain reaction single-strand conformation polymorphism analysis.

Mutations of the p53 gene play an important role in the development of common human malignancies. We investigated mutations of this gene in 26 surgical specimens of esophageal cancer using the polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis. The results were correlated with histological findings, DNA ploidy and the short-term relapse of the disease. PCR-SSCP analysis detected mutations of the p53 gene in 10 tumors (38%), eight in exons 5-6 and two in exons 7-8. A higher incidence of lymph node metastasis, poorly differentiated tumor, DNA aneuploidy and short-term relapse of the disease was observed in cases with p53 gene mutations, although the findings were not statistically significant.

Base Sequence↗

Sensitive detection of p53 gene mutations in esophageal endoscopic biopsy specimens by cell sorting combined with polymerase chain reaction single-strand conformation polymorphism analysis.

For the rapid and sensitive detection of p53 gene mutations in esophageal endoscopic biopsy specimens, we combined cell sorting with the polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) analysis. Mutations in exons 5-8 of the p53 gene were investigated by PCR-SSCP analysis using 10(3) sorted nuclei obtained from each endoscopic biopsy specimen of 16 patients with esophageal cancer. DNAs extracted from their respective surgical specimens were investigated by a conventional method of PCR-SSCP analysis. Mutations in the biopsy specimens were detected in 6 of the 12 aneuploid tumors but in none of the 4 diploid tumors. After tumor cell enrichment by cell sorting, one mutation in exon 8 became apparent, which could not be detected from the surgical specimen by a conventional method of PCR-SSCP analysis. This method should improve the sensitivity of detecting p53 gene mutations, and provides additional information concerning the DNA ploidy pattern in the tumors.

Aged↗

Airway epithelial cells enhance eosinophil survival.

Guinea pig and human eosinophils were co-cultured with or without epithelial cells (controls). Eosinophil survival was enhanced in the presence of the cultured epithelial cells in a number-dependent fashion. Further, supernatants from cultured epithelial cells also enhanced eosinophil survival. Both a monoclonal antibody to GM-CSF and indomethacin inhibited these epithelial-cell-mediated effects, and GM-CSF and PGE2 were shown to prolong eosinophil survival. These findings indicate that airway epithelial cells can enhance eosinophil survival. It is suggested that the mechanism may involve GM-CSF and PGE2 generation.

Animals↗

Human lung mast cells and pulmonary macrophages produce tumor necrosis factor-alpha in sensitized lung tissue after IgE receptor triggering.

Tumor necrosis factor (TNF) is considered to play a key role in the pathogenesis of allergic disorders. We examined TNF production in human lung fragments after IgE receptor triggering at mRNA and protein levels. IgE receptor triggering was performed by sensitizing lung fragments with monoclonal human IgE and then exposing them to anti-human IgE antibody. Cytotoxic activity against L929 cells appeared in the culture supernatant of lung fragments 2 h after IgE receptor triggering and increased for up to 4 h. This cytotoxic activity was completely neutralized by anti-human TNF antibody. Northern blot analysis demonstrated that 1.8-kb TNF mRNA transcripts in sensitized lung fragments were expressed as early as 1 h after IgE receptor triggering and continued up to 4 h. Immunohistochemical analysis revealed TNF localization in tissue mast cells, alveolar macrophages, tissue macrophages, and bronchial epithelial cells. Double staining with anti-TNF antibody and alcian blue clearly identified that lung mast cells are one of the TNF-positive cell types in the pulmonary tissue. With immunoelectron microscopy, TNF immunoreactivity was detected in the rough endoplasmic reticulum and the perinuclear spaces in tissue macrophages, and in the cytosol and the perinuclear spaces in bronchial epithelial cells. In addition, IgE was detected on the cell surface of mast cells, tissue macrophages, and alveolar macrophages. These results suggest that TNF is released from mast cells and pulmonary macrophages through IgE receptor triggering and may play a key role in the allergic reaction in human airway.

Animals↗