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Biomedical subjects

K Tomonari

Publications and source records attributed to K Tomonari.

67 records · Page 4Linked to original sources
PubMed1985

T-cell receptor expressed on an autoreactive T-cell clone, clone 4. I. Induction of various T-receptor functions by anti-T idiotypic antibodies.

Three monoclonal antibodies (1G3, 2H11, and 3G12) specific for a syngeneic Ek-specific T-cell clone, clone 4, have been established. The antibodies specifically blocked not only the activation of the clone in response to the specific antigen Ek but also the activation by IL-2. Kinetic studies of the blocking activity revealed that the antibodies blocked activation not only through steric hindrance of the antigen-binding site of the receptor but also via inhibition of DNA synthesis. The antibodies induced unresponsiveness of the clone to the specific antigen Ek, but not to nonspecific activation by IL-2. The state of unresponsiveness induced by 1G3 continued for 14 days, the longest time so far examined. The recovery from the unresponsiveness (tolerance) was not observed unless the clone cells proliferated vigorously in response to IL-2. The idiotope recognised by 1G3 was different from that by 2H11 and/or 3G12. This might explain some functional differences elicited by the antibodies.

Animals↗
PubMed1984

Expression of H-Y antigen by female mice carrying Sxr.

The minor transplantation antigen H-Y can cause graft rejection and can stimulate the generation of H-2-restricted T cell responses. We have used both responses to type karyotypically abnormal mice for the presence of H-Y antigen, in order to investigate the role of H-Y in sex determination. The mice under scrutiny were Sxr5-carrying females derived by crossing females carrying the T(16;X)16H translocation with Sxr carrying males. These females were fully fertile and were H-Y positive. These results are consistent with the testis determining gene, Tdy, which may or may not be H-Y, having a threshold effect on testis differentiation during embryogenesis. They also show that the presence of H-Y in adult females does not impair reproduction.

Animals↗
PubMed1983

Antigen and MHC restriction specificity of two types of cloned male-specific T cell lines.

Two types of H-Y antigen-specific cloned T cell lines were established. Clone 2-1 is an IAb restricted proliferating T cell line and clone 10-2 is an H-2Db restricted proliferating and cytotoxic T cell line. Clone 2-1 proliferated in response to H-Y antigen with an IAb restriction in the absence of IL 2. IAb mutant B6.C-H-2bm12 (bm12) mice did not stimulate this clone. This defect may be the cause of the unresponsiveness to H-Y antigen with cytotoxic T lymphocytes (CTL) in bm 12 mice (i.e., the failure of activation of H-Y-specific helper T cells). Although (B10.A X bm12)F1 mice are known to show functional complementation, as demonstrated by the presentation of insulin to helper T cells and the H-Y-specific CTL response, the F1 male cells could not stimulate this clone. The IA determinant restricting H-Y antigen presentation to helper T cells and/or the H-Y antigenic determinant seems to differ between C57BL/6 (B6) and the F1 mice. Monoclonal anti-IAb antibodies but not anti-H-Y antibodies blocked the proliferation of this clone. The clone had no cytotoxic activity unless Con A was added to the cytotoxicity assay culture. Clone 10-2 proliferated in response to H-Y antigen with an H-2Db restriction. Proliferation was not observed unless specific stimulator cells and IL 2 were supplied to the culture; IL 2 alone could not support this clone. The clone did not respond to male cells from the H-2Db mutant B6.C-H-2bm14 (bm14). The clone had cytotoxic activity against male H-2Db+ cells but not against male bm14 cells. This evidence indicates that the mutation of bm14 occurred in the structural gene coding for a molecule on which a determinant restricting the recognition of H-Y antigen by B6 CTL exists. The phenotypes of clone 2-1 were Thy-1.2+, Ly-1.2-, Ly-2.2-, IAb-, and H-2Kb+, and the phenotypes of clone 10-2 were Thy-1.2+, Ly-1.2-, Ly-2.2+, IAb-, and H-2Kb+.

Animals↗
PubMed1980

Cytotoxic T cells generated in the autologous mixed lymphocyte reaction. I. Primary autologous mixed lymphocyte reaction.

In the course of the culture of an autologous mixed lymphocyte reaction (AMLR), T cells proliferated in response to autologous non-T cells, and differentiated to cytotoxic T cells (AMLR killers). DNA synthesis was necessary to generate AMLR killers, as the elimination of autoreactive proliferating cells with BUdR and UV light completely abrogated AMLR killer cytolysis. Amlr killers lysed various lymphoid cell lines, including autologous B cell lines, autologous or allogeneic mitogen blasts stimulated by Con A, PHA, or pokeweed mitogen, variious nonlymphoid cell lines derived from human, mouse, or rat, and weakly normal autologous or allogeneic non-T cells. KMT-17, methylcholanthrene-induced rat fibrosarcoma, was the only resistant cell line to have been tested. AMLR killers had characteristics similar to NK cells, Major histocompatibility antigens were not the target antigens for AMLR killers. AMLR killers distinguished the blasts stimulated by alloantigens as self from the blasts stimulated by mitogens as non-self.

Animals↗
PubMed1980

Self recognition by autologous mixed lymphocyte reaction-primed cells.

Human T cells were separated with neuraminidase-treated autologous erythrocytes into auto-rosette-forming cells (ARFC) and non-ARFC (N-ARFC). These 2 subsets were examined for reactivity to autologous non-T cells. When N-ARFC were stimulated by autologous non-T cells, blastogenesis was weak; ARFC, however, proliferated vigorously. ARFC were revealed to be the major subset that responded and proliferated in autologous mixed lymphocyte reaction (AMLR). AMLR-primed cells were restimulated by autologous or allogeneic non-T cells to study self recognition in relation to HLA complex. Self recognition by AMLR-primed cells was closely related to HLA complex, and absolute identity of HLA complex was necessary to recognize allogeneic cells as self. In addition, in respect to the responder cell difference between AMLR and allogeneic MLR, the reactivity of 2 kinds of cells (i.e., AMLR-primed cells and alloreactive cells) strongly suggested that autoreactive T cells were distinguished from alloreactive T cells.

Cell Division↗
PubMed1979

Induction of autoreactive cells by the preculture of human peripheral blood mononuclear cells with the autologous fresh plasma.

An AMLR in which precultured cells proliferated in response to fresh non-T cells is described. In our system, the responder is human peripheral blood mononuclear cells precultured in the autologous fresh plasma for up to 16 days, and the stimulator is fresh autologous non-T cells. Results suggested that there were two subpopulations of autoreactive cells obtained from the preculture; the high and low density small lymphocytes, both having ERF activity. The autoreactivity of low density cells was augmented when either macrophages or N-ERF-cells were depleted from PBM and thereafter precultures wre performed. A survey of the functional characteristics of the responding cells showed that the responding cells had NK activity against Molt-4 cells but had no significant ADCC activity against target CRBC. Mechanisms for the induction of autoreactive cells by the preculture in the presence of autologous fresh plasma are discussed.

Antibody-Dependent Cell Cytotoxicity↗
PubMedDate not supplied

Male sexual differentiation in mice lacking H-Y antigen.

The sexual phenotype of an adult mammal depends on whether the fetal gonad has differentiated as a testis or as an ovary. Because individuals of XY or XXY sex chromosome constitution develop as males, while XX and XO individuals develop as females, the presence of a Y chromosome seems normally to be required for testis differentiation and its absence to be necessary for differentiation of an ovary. The nature of the hypothetical Y-dependent substance responsible for masculinization of the indifferent gonad has been a matter for debate. A male-specific transplantation antigen, H-Y, has been known for many years and more recently a serologically detected antigen, also male-specific, has been reported. Those who believe that the two are antigenically distinct refer to the latter as SDM (serologically detected male) antigen, but many refer to both as H-Y antigen. The hypothesis that H-Y is itself the Y-dependent testis inducer, although supported by little or no direct evidence, is economical and hence attractive. H-Y antigen is frequently stated to be the substance responsible for primary sex determination (for example, see ref. 11). We report here that H-Y is absent from certain mice that develop testes and are of indisputably male phenotype, hence this transplantation antigen is unlikely to be responsible for testis determination.

Animals↗
PubMedDate not supplied

Root of the small-bowel mesentery: correlative anatomy and CT features of pathologic conditions.

The root of the small-bowel mesentery (SBM) is an important peritoneal fold that is contiguous to other peritoneal ligaments and mesocolons. Several pathologic conditions can occur in the SBM itself, and diseases that spread through the connections from adjacent organs frequently involve it. The root of the SBM is contiguous to the hepatoduodenal ligament around the superior mesenteric vein (SMV) and contiguous to the right side of the transverse mesocolon around the gastrocolic trunk. The inferior mesenteric vein, which is a landmark of the descending mesocolon, runs along the left side of the root of the SBM. Malignant neoplasms can spread to the SBM by means of direct extension, extension along the neural plexus, extension along neighboring ligaments, or extension along lymphatic vessels. Inflammatory conditions such as pancreatitis and perforation of a jejunal diverticulum can also spread to the SBM. Anomalies that can occur in the SBM include rotation anomalies and internal hernia. Vascular lesions of the SBM include thrombosis of the superior mesenteric artery (SMA), acute SMV thrombosis, SMA dissection, arterioportal fistula, and portal venous gas. Other pathologic conditions that can occur in the SBM are edema or congestion, mesenteric tear, mesenteric panniculitis, and tumors or tumorlike lesions.

Humans↗
PubMedDate not supplied

Leiomyoma of the parapharyngeal space.

A rare case of leiomyoma of the prestyloid parapharyngeal space is reported together with computed tomographic and magnetic resonance imaging findings. The tumor appeared as a well-circumscribed ovoid mass with some calcifications and lobulations. Because the attenuation, signal intensity, and shape of the mass were not specific and were similar to those of a pleomorhic adenoma, the most common tumor of the prestyloid parapharyngeal space, radiological differentiation of leiomyoma from pleomorphic adenoma of the prestyloid parapharyngeal space was difficult.

Adult↗
PubMedDate not supplied

Appendiceal abscess mimicking infected urachal cyst in a child with intestinal malrotation.

An appendiceal abscess with intestinal malrotation can occur anywhere in the abdomen, not only in the right lower quadrant. We report a case presenting a midline mass of the lower abdomen whose computed tomography (CT) and ultrasonography (US) findings mimicked a urachal abscess. A retrospective review of CT findings led to the correct diagnosis by showing malposition of the ascending colon.

Abscess↗