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S Mitani

Publications and source records attributed to S Mitani.

At least 73 records · Page 4Linked to original sources
PubMed1988

Expression of c-myc oncogene product and ras family oncogene products in various human malignant lymphomas defined by immunohistochemical techniques.

The authors studied the expression of c-myc and ras family oncogene products in 43 cases of malignant lymphoma (ML) using the immunoperoxidase method. Unfixed frozen sections of lymph nodes from four patients with Hodgkin's disease and 39 with non-Hodgkin's lymphoma, together with normal lymph nodes, were studied by the avidin-biotin-peroxidase complex (ABC) technique. Two monoclonal antibodies, MYC-2 raised against recombinant human c-myc protein (reacting specifically with the c-myc products P62 and P67) and RASK-4 (raised against recombinant P21 and reacting specifically with ras-family product P21) were used. The c-myc product was detected in nuclei of ML cells and some normal, mainly germinal center, lymphocytes. When the staining intensity shown by normal germinal-center lymphocytes was graded as positive (+) or weakly positive (+/-), a very intensely positive reaction ( to ++) was observed in 37 cases (86%) of ML, a positive reaction (+) in four cases (9.3%), and a weakly positive reaction (+/-) in two cases (4.7%). The ras family oncogene product reaction was intensely positive (++) in two cases (4.7%), positive (+) in 16 cases (37.2%), weakly positive (+/-) in 13 cases (30.2%), and negative in 12 cases (27.9%). Western blot analysis confirmed an elevated level of c-myc products in two cases, which showed intense MYC-2 staining, and of ras family products in one case, which demonstrated intense RASK-4 staining. The enhanced expression of these gene products may play an important role in lymphomagenesis of such cases.

Antibodies, Monoclonal↗
PubMed1988

Analysis of growth factors in renal cell carcinoma.

Tissue extracts prepared from human renal tissue, renal cell carcinoma and serum-free conditioned media of ACHN cells and A498 cells, cell line originated from human renal cell carcinoma, stimulated DNA synthesis of BALB/c 3T3 cells. The activity (growth factor activity) was significantly higher in renal cell carcinoma than in normal tissues. Radioreceptor assay revealed that the contents of epidermal growth factor and type alpha transforming growth factor in the tissue extracts from renal cell carcinoma and conditioned media from renal cell carcinoma cell lines were below detectable level. Most of growth factor activity of the tissue extracts and conditioned media showed high affinity for heparin-Ultrogel, indicating that the major growth factor activity was due to heparin-binding growth factor(s). In addition, renal cell carcinoma contained growth factor activity for ACHN cells, which did not show specific affinity for heparin-Ultrogel.

Binding, Competitive↗
PubMed1988

Monoclonal antibodies against larval nervous system of Xenopus laevis: their specificities and application to analysis of neural development.

Monoclonal antibodies were raised against larval tissues from Xenopus laevis. Two of them which bound to neural tissue were examined for their cytological specificities by indirect immunofluorescence on larval frozen sections. One of the monoclonal antibodies (NM1) had affinity for both neural and muscular tissues, while the other (N1) bound exclusively to neural tissue. NM1 was shown in the neural tissue to possess a high affinity for the axons from a large population of neurons and possibly the radial fibers from ependymal cells as well. On the other hand, N1 showed a high specificity for some cellular elements other than axons in the white matter, most likely dendrites. For both antibodies, binding to cell bodies could not be detected. The spatial and temporal distribution of the NM1 and N1 antigens was investigated. In the mid-trunk region the NM1 antigen in axons was first detected at stage 29/30, nearly 10 h earlier than the N1 antigen (stage 33/34). In a larva at stage 37/38, the axonal NM1 antigen was distributed throughout the nervous system, whereas the distribution of N1 antigen was restricted to the brainstem and the trunk spinal cord. The N1 antigen-positive area continued expanding rostrocaudally with increasing developmental age. The distribution of NM1 and N1 antigens, thus, follows patterns which are consistent with the previously shown general patterns of neuronal process development; the earlier outgrowth of axons than dendrites, and the rostrocaudal gradient in process development. We also examined the two monoclonal antibodies in a cell culture system derived from hatching larvae and found that cytological specificity was substantially conserved; NM1 possessed affinity for both neuronal and muscular cells and N1 bound exclusively to neuronal cells, though N1 bound to cell bodies as well as processes in culture.

Animals↗
PubMed1988

Increased immunoglobulin E Fc receptor bearing cells in germinal centers of hyperimmunoglobulinemia E patients.

Lymph nodes from 6 patients with hyperimmunoglobulinemia E (hyper-IgE; 4 with Kimura's disease, 1 with atopic dermatitis, and 1 with immunoblastic lymphadenopathy-like T cell lymphoma) and from 7 patients with normal IgE levels were studied to determine the localization of dendritic reticulum cells and of cells bearing Fc epsilon and C3d receptors and immunoglobulin E. The avidin-biotin-glucose oxidase method was used for unfixed biopsy specimens. To identify the above-mentioned cells, H107, a murine monoclonal antibody specific to the Fc epsilon receptor molecule, and corresponding antibodies specific to the other cell types were used. In 5 hyper-IgE patients (4 with Kimura's disease and 1 with atopic dermatitis) all germinal centers of the lymph nodes showed heavy reticular staining with H107, the dendritic reticulum cells being most intensely stained. In contrast, the germinal centers of the lymph nodes in the 7 patients with a normal IgE level only lightly or partially stained with H107. The staining pattern of anti-IgE was similar to that of H107 in the hyper-IgE cases. Likewise, C3d receptor and dendritic reticulum cell-related antigens were demonstrated very intensely in all germinal centers in lymph nodes of patients with hyper-IgE and normal IgE levels. These findings suggest that in a hyper-IgE state increased numbers of dendritic reticulum cells in a germinal center express the Fc epsilon receptor and that such cells may play a role in the differentiation of IgE-producing memory B cells.

Angiolymphoid Hyperplasia with Eosinophilia↗
PubMed1988

Effect of soft diets on craniofacial growth in mice.

The 300 C3H/He strain male mice were divided into 3 groups; solid, kneaded, and liquid diet groups. Each group was consisted of 5 cross-sectional subgroups, i.e. 3, 5, 7, 12 and 20 weeks subgroups. X-ray pictures of their craniofacial complex were measured to investigate the extent and time that growth retardation can be recognized in the cranium. As the results, soft diets could retard craniofacial growth, although it accelerated body growth. Increase of height and depth of distal part of mandible and all 3 dimensions of craniofacial complex were affected by taking soft diets through the growing period. Some of them were apparent even in weaning period. As the distal areas of both craniofacial complex and mandible are closely related to jaw function, growth retardation of this area could be explained as the skeletal adaptation to the soft diets.

Animals↗
PubMed1985

The reduction of calcium current associated with early differentiation of the murine embryo.

Membrane currents of intact oocytes and early embryos of the mouse and the hamster were analysed with voltage-clamp techniques. In both mouse and hamster the amplitude of Ca inward currents decreased with time during early development, and they were undetectable by the 8-cell stage, while the threshold potential, alkaline earth cation selectivity, and activation-inactivation kinetics remained unchanged. The reduction of Ca currents was further confirmed in the 2-cell embryo whose cleavage was arrested with use of cytochalasin D, but the process was slightly delayed by comparison with that of the intact embryo. Early differentiation of cytochalasin-D-treated embryos was comparable to that of the intact embryo in terms of intercellular couplings and intercellular fluid accumulation. But these processes were also delayed as in the case of Ca current reduction. The outward current in the hamster embryo which was reflected in the resting membrane conductance began to increase abruptly after the 2-cell stage and seemed to reach the maximum at the end of the 4-cell or 8-cell stage. The increase apparently occurred reciprocally with the decrease in Ca inward current. A similar but much smaller increase in resting membrane conductance also occurred in the cleavage-arrested mouse 2-cell embryo almost at the same development stage at which the abolition of Ca current was found. The possibility is discussed that Ca channels have a role in cell differentiation in early murine embryos.

Action Potentials↗
PubMed1982

Immunoglobulin E-suppressing and immunoglobulin G-enhancing tetanus toxoid prepared by conjugation with pullulan.

Immunoglobulin E (IgE) antibody response was found to be suppressed selectively and antigen specifically in mice given an antigen conjugated with pullulan, a linear copolymer of maltotriose, whereas IgM and IgG antibody responses were enhanced. On the basis of this finding, tetanus toxin was conjugated with pullulan by cyanuric chloride in the hope that the toxin would be detoxified by the conjugation procedure and could be used as an IgE-suppressing and IgG-enhancing toxoid without the aid of an aluminum adjuvant. This procedure of tetanus toxoid-pullulan conjugation apparently detoxified the toxin. Administration of the resulting tetanus toxoid, tetanus toxin-pullulan conjugate, to mice induced strong suppression of IgE antibody response with fairly good IgG response, whereas the alum-precipitated toxoid or plain toxoid, customarily used for vaccination, elicited high IgE antibody formation. The IgE antibody response was minimal, but the IgG antibody response was maximal in the conjugate-primed mice even after a booster injection with an IgE antibody-inducing dose of the alum-precipitated toxoid.

Animals↗