Tumor promoter stimulated irreversible binding of N-methylaminoazobenzene to polymorphonuclear leukocyte DNA.
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Biomedical subjects
Y Tsuruta
Publications and source records attributed to Y Tsuruta.
Peroxidase-mediated irreversible binding of arylamine carcinogens to DNA in intact polymorphonuclear leukocytes activated by a tumor promoter.
Addition of the tumor promoter phorbol myristate acetate to polymorphonuclear leukocytes results in the oxidation of the arylamine carcinogens; [14C]benzidine, N-[14C]methylaminoazobenzene and [14C]aminofluorene to reactive intermediate(s) that bind irreversibly to the leukocyte DNA. The binding was dependent on oxygen and was decreased by sulfhydryl inhibitors and phenolic antioxidants that inhibit the respiratory burst triggered by the phorbol myristate. Both the binding and the respiratory burst were increased by azide, presumably as a result of intracellular catalase inhibition. However higher concentrations of azide and cyanide prevented binding without affecting the respiratory burst indicating that myeloperoxidase is a catalyst for the binding. Granules isolated from the activated leukocytes and H2O2 catalyzed a cyanide sensitive benzidine binding to calf thymus DNA. Myeloperoxidase and H2O2 also catalysed extensive binding of these arylamines to calf thymus DNA. The leukocytes appear to be a useful model cell for studying one electron oxidation-catalyzed carcinogen activation.
Amines↗
Analysis of TCRAV and TCRBV repertoires in healthy individuals by microplate hybridization assay.
We have developed an adaptor ligation PCR-based microplate hybridization assay (MHA) for analysis of T cell receptor alpha chain variable region (TCRAV) and T cell receptor beta chain variable region (TCRBV) repertoires. Forty three TCRAV and thirty eight TCRBV-specific probes were immobilized onto microplate wells in water-soluble carbodiimide. After hybridization of 5'-biotinylated PCR products, quantitative ELISA was carried out and followed by automated colorimetric reading. The conditions for immobilization and hybridization were optimized using representative TCRBV-specific probes. The sensitivity of MHA allows us to detect as low as 40 pg of biotinylated PCR products. The frequencies of individual V segments obtained by MHA were consistent with those obtained by FACS analysis and reverse dot blot assays. Analysis of the entire TCRAV and TCRBV repertoires could be done using a single 96-well plate, and completed in less than 6 h. Simplicity and reproducibility of this method make it suitable for routine laboratory use. The expression of TCRAV and TCRBV segments was next studied in peripheral blood mononuclear cells (PBMC) of 14 healthy donors using the newly developed MHA method. TCRAV8S1, TCRAV23S1, TCRBV2S1, TCRBV3S1, TCRBV4S1, and TCRBV6S5 were highly expressed in PBMC. Further, the TCRAV repertoires among individuals were less variable compared to the TCRBV repertoires. Interestingly, considerable variations in the expression levels of BV3S1, BV4S1, and BV17S1 were observed among individuals. One polymorphic site was found at the coding region of BV4S1, and there were two alleles. These results suggest that variable expression among individuals may be associated with unknown allelic polymorphism in coding and/or regulatory regions of these TCRBV segments, or with disparity in HLA genes.
Flow Cytometry↗
Radiation therapy for primary non-Hodgkin's lymphoma of the head and neck.
From October 1977 through September 1986, a total of 77 patients (Stage I, 26; II, 35; and III-IV, 16) with primary non-Hodgkin's lymphoma (NHL) of the head and neck were treated with radiation therapy and chemotherapy (CVP or CHOP regimen) or radiation therapy alone. Actuarial 5-year survival rates by stage were 79% in Stage I, 35% in II, and 8% in III-IV. Significant prognostic factors were clinical stage (p = 0.0001), histological grade by the Working Formulation (p = 0.0089), and surface marker (T and B cell analysis) (p = 0.0001). In Stage II patients, the serum lactate dehydrogenase (LDH) level (p = 0.0286), the number of cervical lymph nodes involved (p less than 0.03), and maintenance chemotherapy after initial treatment (p = 0.0077) were significant prognostic factors. In conclusion, more intensive chemoradiotherapy is necessary as the first-line treatment in those with poor prognosis, especially those with T-cell type and high grade histology. In addition, maintenance chemotherapy after initial chemoradiotherapy is very important for Stage II NHL patients, especially those with a high LDH value or multiple cervical lymph node involvement.
Antineoplastic Combined Chemotherapy Protocols↗