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Biomedical subjects

N Ikuta

Publications and source records attributed to N Ikuta.

At least 55 records · Page 3Linked to original sources
PubMed1990

The alpha-amylase gene as a marker for gene cloning: direct screening of recombinant clones.

We report the construction and use of a new system for the direct screening of recombinant clones after transformation. The system uses a Bacillus subtilis-Escherichia coli shuttle vector that carries the B. subtilis structural gene for alpha-amylase. Insertion of foreign DNA into this gene results in a loss of amylolytic activity in the host cells that can be assayed using a simple and inexpensive staining procedure.

Bacillus subtilis↗
PubMed1989

[Effect of azelastine on bronchial hyperresponsiveness].

We have investigated the effect of azelastine on bronchial responsiveness in 25 asthmatics, using methacholine inhalation challenge, (Astograph). Three parameters, initial respiratory resistance (RrsC), bronchial sensitivity (Dmin), and bronchial reactivity (SGrs/GrsC) were studied. After 8 weeks' treatment with 2 mg azelastine b.i.d., Dmin was increased significantly and after 4 weeks an insignificant increase was observed. RrsC and SGrs/GrsC did not change significantly during the 8 week treatment. Recent advances have revealed that various chemical mediators, especially leukotrienes, are closely related to bronchial hyperresponsiveness. Accordingly, the improvement of Dmin observed during azelastine treatment might be ascribed to its inhibitory action on the synthesis and release of leukotrienes.

Adult↗
PubMed1989

[A case of adenomatoid mesothelioma of the pleura].

A case of adenomatoid mesothelioma of the pleura was presented. The patient was a 69-year-old woman with diabetes mellitus. She was admitted to our hospital because of a chest roentgenographic abnormality, which was pointed out during her clinical course. Chest X-ray-film on admission revealed a semicircular lesion located in the left lower lung field. The physical examination and laboratory data showed no abnormalities. Left lower lobectomy was performed. The tumor was approximately, 3.0 x 3.0 x 3.0 cm, elastic soft, encapsulated, and originated from the pulmonary pleura. The histological findings of the tumor showed benign epithelial localized pleural mesothelioma. However histologically, the tumor tissue was not like the usual epithelial type. That is, most cells which had intracellular vacuoles, were similar to signet ring cell. The tumor was diagnosed as adenomatoid mesothelioma of the pleura.

Aged↗
PubMed1988

Pseudolymphoma of the thyroid.

An unusual case of pseudolymphoma of the thyroid is reported. The tumor was histologically characterized by good demarcation, mature lymphocytes with prominent follicle formation and germinal centers, and mature plasma cells. Immunohistochemical staining revealed a similar distribution of T- and B-cells to reactive lymph nodes and a polyclonal nature of the plasma cell infiltrate. These findings are closely related to the entity, pseudolymphoma in other organs. Differential diagnosis from follicular lymphoma or ectopic thymic tissue is discussed.

Female↗
PubMed1987

Primary T-cell lymphoma of the thyroid.

A rare case of non-Hodgkin's malignant T-cell lymphoma of the thyroid in a 79-year-old woman is reported. Light microscopically, the tumor showed diffuse proliferation of lymphoid cells, revealing prominent nuclear irregularity and occasional multilobulated nuclei, and was diagnosed as a diffuse lymphoma of medium-sized cell type. Electron microscopically, the tumor cells were seen to possess irregularly indented nuclei. Immunologic surface marker studies showed that the lymphoma cells were positive for T-lymphocyte-lineage antigens, OKT4 and OKT11, and did not react with B-lymphocyte-associated antigens. These findings indicated that the lymphoma had a T-cell phenotype.

Aged↗
PubMed1984

Immunohistologic localization and immune phenotypes of lymphocytes expressing Tac antigen in human lymphoid tissues.

A monoclonal anti-Tac antibody has been identified as a putative antibody against the human interleukin 2 (IL 2) receptor. In the present study, anti-Tac antibody was used to determine the location of cells expressing IL 2 receptors in frozen sections of human lymph nodes and tonsils by means of an immunoperoxidase technique. It was found that a substantial number of lymphoid cells reactive with anti-Tac antibody were present in these tissues. The majority of the Tac-positive cells were located in the paracortical and interfollicular regions of lymph nodes and tonsils, whereas only a few Tac-positive cells were scattered in the mantle zones and germinal centers of the secondary follicles. In contrast, no Tac-positive cells were demonstrated on cytocentrifuge preparations of peripheral blood lymphocytes from some of tissue donors, as evaluated by the same technique. In some experiments, a double-marker immunofluorescence analysis with the use of different fluorochromes, fluorescein isothiocyanate (FITC), and tetramethylrhodamine isothiocyanate (TRITC) was applied to characterize the phenotypes of cells expressing Tac antigen. Double staining with TRITC and FITC, respectively, for the identification of Tac-positive cells and T cells, showed that Tac-positive cells in lymph nodes and tonsils almost exclusively co-expressed a pan-T cell marker, Leu-1 antigen, that probably does not belong to non-T cell lineages. About 80% of Tac-positive cells were Leu-3 (helper/inducer) positive, and 20% of them Leu-2 (suppressor/cytotoxic) positive. These observations imply the plausible notion that an IL 2-mediated immune activation of T cells may actually occur in local lymphoid organs.

Adult↗
PubMed1983

Effects of OKT3+, OKT4+ and OKT8+ T cell subsets on steady-state granulopoiesis in vitro.

The present study was undertaken to elucidate the role of T cell subsets in regulating the in vitro growth of human granulopoietic progenitor cells (CFU-C). Prior to CFU-C assay, mononuclear cells obtained from bone marrow and cord blood were depleted of T cells or functionally distinct T cell subsets by the method of complement-mediated cytolysis with the use of monoclonal antibodies, OKT3, OKT4 and OKT8. The depletion of any T cell subset of OKT3+, OKT4+ or OKT8+ cells from bone marrow and cord blood cells showed no significant alterations in the generation of CFU-C. The supplementation to the in vitro culture system of OKT4+ or OKT8+ cells, which had been negatively selected by complement-mediated cytolysis using the mutually exclusive monoclonal OKT8 or OKT4 antibody, respectively, did not alter the growth of CFU-C-derived colonies without mitogenic stimulation. In contrast, the production of colony-stimulating activity (CSA) in peripheral blood mononuclear cells was significantly reduced by removing not only OKT3+ cells but also OKT4+ or OKT8+ cell subsets. There were no significant differences in the degree of reduction between the different procedures. These results suggested that T cell subsets played an important role in the regulation of steady-state granulopoiesis through the stimulation of CSA production. The presence of a specific subset of T cells in CSA production was not demonstrated.

Antibodies, Monoclonal↗
PubMed1983

Kinetics of expression of T-cell "activation" antigens on in vivo- and in vitro-stimulated T cells.

The in vivo expression of T-cell activation antigens defined by means of an OKT series of monoclonal antibodies and the anti-Tac antibody was evaluated in peripheral T lymphocytes obtained from patients with infectious mononucleosis and in cerebrospinal fluid (CSF) cells collected from individuals with mumps meningitis by the immunoperoxidase method. Although Tac antigen was definitely expressed on about 10% of CSF cells in mumps meningitis, Tac+ T cells could not be identified on any peripheral blood T cells in infectious mononucleosis, which expressed OKIa 1+, OKT10+, and OKT9+ determinants, as a probable sign of in vivo activation. The coexpression of Ia+ antigens on a T-cell functional subset might be important for their functional properties. Our kinetic study and cell cycle analysis of the expression of these activation antigens suggested that Tac antigen might be expressed at the early stage of the G1 phase of the cell cycle; OKT9+ antigen at the late stage of the G1; and Ia+ and OKT10+ determinants might be expressed at the S phase or later on in vitro, probably one after another.

Acute Disease↗
PubMed1982

Expression of Ia-like antigens defined by monoclonal OKIal antibody of hemopoietic progenitor cells in cord blood: a comparison with human bone marrow.

Expression of Ia antigens on granulocyte/macrophage colony-forming cells (CFU-GM) in human cord blood was compared with that in bone marrow with the use of monoclonal OKIal antibody. Mononuclear cells prepared from cord blood and bone marrow were pretreated with OKIal antibody plus complement, and, thereafter, the ability of cord blood and bone marrow cells to form colonies of CFU-GM was assayed in semisolid agar culture. Consistent reduction in the number of CFU-GM in cord blood to 58.8% +/- 13.0% (mean +/- SD) of controls treated with complement alone was shown after elimination of Ia-antigen-bearing CFU-GM, but was significantly remarkable than that in bone marrow (18.0% +/- 5.6%). Although the reduction of both granulocyte (CFC-G) and macrophage colony (CFC-M) types of cord blood, characterized by the double staining for esterase activity, was shown following treatment with OKIal antibody plus complement, the relative inhibition of CFC-G weas significantly greater than that of CFC-M (p less than 0.02). These results suggest some differences in the characteristics of Ia-antigen-bearing CFU-GM between cord blood and bone marrow cells. Furthermore, it is suggested that Ia-dependent regulatory mechanisms might participate in the differentiation of CFU-GM to CFC-G and CFC-M.

Antibodies, Monoclonal↗