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Biomedical subjects

R Ceredig

Publications and source records attributed to R Ceredig.

100 records · Page 6Linked to original sources
PubMed1979

Comparison of natural killer cells induced by Kunjin virus and Corynebacterium parvum with those occurring naturally in nude mice.

Natural killer (NK) cells are rapidly elicited in the spleen and peritoneal cavity of mice inoculated intravenously or intraperitoneally with live Kunjin virus, and more slowly in the peritoneal cavity of mice inoculated intraperitoneally with Formalin-inactivated Corynebacterium parvum. NK cells induced by either agent display cytotoxicity for a similar spectrum of syngeneic, allogeneic, and xenogeneic cultured cell lines. By contrast, the cells occurring naturally in the spleen of congenitally athymic (nude) mice show substantially lower NK activity and are cytotoxic for a more restricted range of target cell lines. The distinction suggests that there may be more than one type of NK cell or that activation enhances the cytotoxicity and perhaps broadens the range of target specificity of endogenous NK cells.

Animals↗
PubMed1978

Ontogeny of actin and microsomal antigens in gastric parietal cells.

Six fetal and 10 neonatal rat or mouse stomachs and a 14-week human fetal stomach were examined for immunofluorescence reactivity with four sera containing parietal cell antibody (PCA) and four other sera containing smooth muscle antibody (SMA). In rat and mouse stomachs, parietal cells first reacted with PCA in 19-day fetal stomachs and with SMA in two-day neonatal rat stomachs or newly-born mouse stomachs. SMA reactivity with fetal rodent stomachs was restricted to the cytoplasm of smooth muscle, the apices of gastric mucosal cells, and the cytoplasm of fibroblasts surrounding invaginating gastric pits. In the 14-week human fetal stomach, parietal cells stained with PCA but not with SMA. Specificity of the staining reactions was established by the complete inhibition of PCA staining by serum absorption with a gastric microsomal fraction but not with actin. Conversely, the SMA staining was abolished by serum immunoabsorption with actin but not with microsomal fraction. These observations, indicating that the development of the parietal cell microsomal antigen precedes that of actin, may be used to distinguish between the staining of parietal cells by SMA and PCA.

Actins↗
PubMed1977

Sequential antitumour immunoreactivity and carcinoembryonic antigen levels as a guide to prognosis in colorectal carcinoma.

Twenty-five patients with colorectal carcinoma were tested for blood-lymphocyte anti-tumour cytotoxicity and carcinoembryonic antigen (CEA) levels at three-monthly intervals for eighteen months or more after resection, and examined clinically every three to six months. Twelve of the patients were followed for two years and one for four years. The six patients whose tumours recurred showed positive blood lymphocyte antitumour cytotoxicity and elevated plasma CEA levels at some time from six months after operation, usually well before the recurrence was clinically detectable.

Adenocarcinoma↗
PubMed1977

Reaction of human smooth muscle autoantibody with gastric parietal cells: a pitfall in the diagnosis of parietal cell autoantibody.

Thirteen smooth muscle antibody (SMA) sera obtained from patients with active chronic hepatitis were examined for immunofluorescence reactivity with gastric mucosal cells. Eight out of 13 sera stained the cytoplasm of gastric parietal cells in a pattern indistinguishable from that obtained with parietal cell autoantibody (PCA). The staining reaction was localised to parietal cells by the demonstration that the same cells stained with both SMA and PCA in double immunofluorescent tests. The SMA staining intensity for parietal cells was weaker than that for smooth muscle. Specificity of the staining reaction for actin was established by the observation that parietal cell staining by SMA was inhibition by serum absorption with skeletal muscle F-actin but not by a microsomal fraction derived from gastric mucosa.

Anemia, Pernicious↗
PubMed1977

Multiple myeloma and monoclonal IgA with anti-actin reactivity.

Serum containing a monoclonal IgA protein from a patient with multiple myeloma gave intense immunofluorescent staining of smooth muscle fibres and the striations of skeletal muscle, cardiac muscle and thymic myoid cells. It also gave a weaker reaction with hepatocytes in a 'polygonal' pattern, and with renal glomeruli in a diffuse pattern. In culture fibroblasts, the serum stained long, parallel cytoplasmic filaments. Specificity of the staining reactions for actin was established by their prevention on serum absorption with skeletal muscle actin, but not by skeletal muscle myosin, tropomyosin or troponin, and by the demonstration that eluates obtained by acid dissociation of the serum-actin precipitates gave the same staining reactions as the original serum. Localization of the anti-actin reactivity to the monoclonal IgA protein was established by the observation that the same staining reactions were obtained with a monospecific IgA conjugate, with the eluate derived from the gamma globulin band of a serumel ectrophoretic strip, and with a purified euglobulin (IgA) fraction; also, the eluates obtained by acid dissociation of the serum actin precipitates contained monoclonal IgA.

Actins↗
PubMedDate not supplied

Differentiation in vitro of Lyt 2+ thymocytes from embryonic Lyt 2- precursors.

In mice, the thymus is regarded as being the primary anatomical site for the generation of immunologically competent T lymphocytes. Such cells comprise approximately 20% of the cells in the thymus and share with T lymphocytes from peripheral lymphoid tissues certain phenotypic properties defined by anti-Lyt antibodies. Thus, most immunocompetent T cells are either Lyt 1+2+ or Lyt 1+2- with the former cells being restricted to recognizing antigen in association with class I (H-2K, D) major histocompatability complex (MHC) products and the latter to class II (H-21) MHC products. Although evidence suggests that Lyt 1+2+ cells are generated from Lyt 1+2- precursor the independent development of two separate Lyt-defined lineages of thymocytes could not be ruled out. Here, the acquisition of Lyt 2 antigen by Lyt 2- cells from late embryonic and early postnatal thymuses is directly demonstrated. Furthermore, by combining cell cycle and Lyt phenotype analysis on a flow microfluorometer, the role of cell division in this differentiation process has been investigated.

Age Factors↗
PubMedDate not supplied

Expression of interleukin-2 receptors as a differentiation marker on intrathymic stem cells.

The thymus is regarded as the primary site for T-cell lymphopoiesis, but very little is known about the lineage inter-relationships of cells within that organ. At least four subpopulations of mouse thymocytes can be defined on the basis of staining with monoclonal antibodies directed against the T-cell differentiation antigens Lyt-2 and L3T4 (ref. 2). Thus immunocompetent (medullary) thymocytes, like peripheral T cells, express either Lyt-2 (cytotoxic phenotype) or L3T4 (helper phenotype) but not both, whereas non-functional (cortical) thymocytes express both markers. In addition, a small subpopulation comprising 2-3% of cells in the thymus and expressing neither Lyt-2 nor L3T4 has recently been described. The latter cells have the properties of intrathymic 'stem cells' in that they are the first to appear in the embryonic thymus and at least some can be shown to give rise, both in vivo (ref. 4. and our unpublished data) and in vitro, to other thymocyte subpopulations. We show here that 50% of Lyt-2-/L3T4- cells in the adult thymus express receptors for the polypeptide growth hormone interleukin-2 (IL-2) whereas other cells in the thymus do not. Furthermore, immunohistochemical localization studies on frozen sections indicate a disperse distribution of IL-2 receptor-positive cells in both the cortex and medulla. These novel findings have potential implications in the context of current models of differentiation pathways within the thymus.

Age Factors↗