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At least 19 recordsLinked to original sources
PubMed1979

Lithium transport across red cell membrane: a cell membrane abnormality in manic-depressive illness.

In the families of manic-depressive patients, relatives with a history of affective disorders had a significantly higher ratio of mean red cell lithium to plasma lithium in vitro than relatives with no such history. A genetically controlled abnormality in lithium-sodium transport, the mechanism that determines the lithium ratio, may play a role in the etiology of some forms of affective disorders.

Biological Transport↗
PubMed1977

Separation of the Moloney leukemia virus-determined cell surface antigen (MCSA) from known virion proteins associated with the cell membrane.

Cell membranes of Moloney lymphoma cells (YAC, of strain A origin) were solubilized by NP40. The antigenicity of the solubilized protein fraction was assayed by inhibition of the corresponding cytotoxic reaction against YAC target cells. The Moloney leukemia virus (MLV)-determined cell surface antigen (MCSA) was detected with mouse antisera, produced by the repeated inoculation of heavily irradiated YAC cells into syngeneic mice. Virion proteins gp71, p30, p15, p12 and p10 were identified with goat or rabbit antisera against purified Rauscher and Friend leukemia virus proteins. MCSA was found to bind to Con-A--Sepharose and was eluted by mannoside together with H-2A AND GP71. In contrast, p30, p12, p10 and part of p15 and p15(E), were not retained on the column and could be separated from MCSA. Passage of the glycoprotein fraction through Sephadex G-200 led to the separation of MCSA activity from gp71 and H-2A. MCSA eluted between the immunoglobulin (IgG) and the bovine serum albumin (BSA) size markers. MCSA could be also separated from the known viral proteins and from H-2 by velocity centrifugation in sucrose gradients. It sedimented with approximately 6.6 S ahead of gp71 (4.4 S) and H-2 (3.2 S). It is suggested that MCSA may be a glycoprotein with an approximate molecular weight of 110,000 and distinct from the known viral proteins gp71, p30, p15(E), p12, p10 and from H-2.

Animals↗
PubMed1976

Cell membrane and cell junctions in differentiation of preimplanted mouse embryos.

Cell membrane and cell junctions in differentiation of preimplanted mouse embryos, (membrana celular y uniones celulares en la diferenciación del embrión de ratón antes de la implantación). Arch. Biol. Med. Exper. 10: 130-134, 1976. The development of cell junctions that seal the peripheral blastomeres could be a decisive step in the differentiation of morulae into blastocysts. The appearance of these junctions is studied by electron microscopy of late morulae and initial blastocysts. Zonulae occludentes as well as impermeability to lanthanum emulsion precedes the appearance of the blastocel and hence might be considered as one of its necessary causes.

Animals↗
PubMed1978

F20C, a new fluorescent membrane probe, moves more slowly in malignant and mitogen-transformed cell membranes than in normal cell membranes.

New fluorescent probes of membrane mobility can be introduced into cell membranes at single points with particles of a membrane mobility agent, A2C. The initial entry of fluorescence from the particle into the cell membrane and the subsequent lateral spread of fluorescence have been observed for cells in suspension. A dramatic difference between the behavior of normal lymphocytes and that of mitogen-transformed and mastocytoma cells is found. Both the initial entry and the spreading of fluorescence are much slower in the transformed and tumor cells than in the normal cells at 18 degrees C. Entry and spread of fluorescence in normal cells become slow enough to be observed only at 12 degrees C or below.

Cell Line↗
PubMed1975

Some characteristics of monocarboxylic acid transfer across the cell membrane of epithelial cells from rat small intestine.

1. The translocation of monovalent organic anions (pyruvate, propionate, acetate and butyrate) across the cell membrane of isolated epithelial cells from rat small intestine was studied by measuring competitive inhibition kinetics, exchange diffusion and temperature dependence of the efflux rate. A possible function of a monocarboxylate carrier in intestine will be discussed. 2. Earlier studies on the inhibition of pyruvate transport of fatty acids were extended to propionate and found to show the same characteristics. The kinetics, however, appeared to be more complex by the contribution of several diffusion pathways for propionate. 3. The mechanism of countertransport was most compatible with an "accelerated exchange diffusion" and could be studied at both sides of the membrane. This exchange diffusion exhibited saturation kinetics. It is proposed that different monocarboxylate anions may have different affinities for a common carrier. 4. Temperature dependence of the efflux of pyruvate and propionate was studied. Arrhenius plots obtained were not found to be linear between 0 and 5 degrees C. Between 5 and 15 degrees C activation energies for pyruvate and propionate efflux rates were found to be 19.6 and 12.6 kcal/mol, respectively.

Acetates↗
PubMed1976

Characteristics of cell membranes from somatic cell hybrids between rat hepatoma and mouse L-cells.

Cell membranes from mouse L-cells (L-B82), rat hepatoma (HTC-H1), and three clones of their somatic cell hybrids (07, V4a, and V5) showing different degrees of density-dependent inhibition of growth were analyzed by polyacrylamide gel electrophoresis. The membrane polypeptides of the hybrid clones were all similar and all showed higher proportions of polypeptides with molecular weights of 56,000 and 45,000 than their parents of their normal counterparts. The major glycoprotein form cell hybrids appeared to be identical with that of rat liver or rat hepatoma cells and different from that of L-cells. One hybrid showed density-dependent inhibition growth; the other two, like both parents, did not. All produced tumors in nude mice, although tumor production by the hybrids was delayed. A large external protein (M.W. 240,000) iodinated by lactoperoxidase-catalyzed reaction was virtually missing in the parents but was present at high levels in all their hybrid clones. Thus, there was a lack of correlation between the presence of this protein, growth control in vitro, and tumorigenicity. Furthermore, no correlation was seen between agglutination of these cells by concanavalin A and tumorigenicity. The factors controlling these membrane properties thus are independent of density-dependent inhibition of growth and of those controlling the expression of cancer.

Agglutination↗
PubMedDate not supplied

Membrane cell markers in human leukemias and lymphomas.

The availability of B- and T-cell membrane markers has provided new approaches and concepts in the study of lymphoproliferative diseases; The present status of knowledge in monoclonal B-cell proliferations, T-cell proliferations such as the Sézary syndrome and chronic lymphocytic leukemia of T-cell origin, acute lymphoblastic leukemias and non-Hodgkin lymphomas is briefly reviewed.

Antibody Formation↗
PubMed1975

Analysis of soluble melanoma cell membrane antigens in metastatic cells of various organs and further studies of antigens present in primary melanoma.

In malignant melanoma, using Sephadex G-200 chromatography and polyacrylamide gel electrophoresis (PAGE), it has been possible to separate two types of skin reactive antigens. The first, found in Sephadex fraction II and PAGE region a appears specific for melanoma. Allogeneic extracts have produced positive reactions in many patients with skin or ocular melanoma, and have given negative reactions in patients with other types of cancer or in patients with ocular lesions simulating melanoma. The second group of antigens, in Sephadex fraction III and PAGE region b were less specific. These antigens produced positive skin reactions in some patients with breast cancer, as well as in patients with melanoma. Reactivity to PAGE region a appeared to be confined to one protein band, but three different bands in region b gave positive reactions. A study was made of the presence or absence of similar antigens in metastatic deposits of malignant melanoma. Metastatic lesions in the following tissues were analyzed: liver, lung, adrenal, skin, and colon. These were compared with pooled primary skin melanomas by skin testing in the same patients. The tumor-associated melanoma antigen, found in Sephadex fraction II and PAGE region a appeared to be strongest in adrenal, lung, and liver metastases. It was found that the protein yield in this region was not indicative of the strength of the antigen. Therefore, a careful, detailed analysis of the protein bands present in PAGE regions a and b from primary skin melanoma was conducted. Only one band in PAGE region a was found to be responsible for positive skin reactivity. This band was found to be a glycolipoprotein. Further studies were also conducted in order to determine whether or not some of the antigens present might be fetal antigens. Some of the protein bands present in Sephadex fraction III and PAGE region b of melanoma appeared to be similar to some of the PAGE region b proteins present in fetal skin cells. Two bands from fetal skin also had the same location on PAGE as two bands from ductal breast cancer, although the relationship to melanoma region b antigens was not exact. These fetal proteins, which seemed to be present both in ductal breast cancer cell membranes and in melanoma cell membranes, might account for the positive skin reactivity seen in this region, and also for the cross reactivity of skin tests with this antigen.

Adrenal Gland Neoplasms↗
PubMed1975

T-cell membrane characteristics of "mycosis cells" in the skin and lymph node.

In some patients with mycosis fungoides atypical cells ("mycosis cells") are found in the blood. Recently the T-cell membrane characteristics of these atypical cells have been described. In this paper the results of a study of the atypical cells isolated from the lymph nodes and the skin lesions of three patients with mycosis fungoides are presented. Using electron microscopy, it could be demonstrated that the atypical cells formed rosettes with uncoated sheep red blood cells, but not with antibody-complement-coated sheep erythrocytes, indicating the T-cell membrane characteristics of the atypical cells.

Aged↗
PubMed1978

Rabbit antiserum against Daudi-cell membrane fractions detects cell surface antigens present on subpopulations of human lymphocytes.

An antiserum was produced by immunization of rabbits with membrane preparations of a human lymphoblastoid B cell line, Daudi. After absorption with a human endometrial carcinoma cell line, this antiserum appeared to be specific for antigen(s) present on adult and fetal thymocytes as well as on tonsillar lymphocytes but absent, or present in very small amounts, on normal or phytohemagglutinin- (PHA) stimulated peripheral blood lymphocytes (PBL). When T and B cell-enriched fractions from tonsillar lymphocytes were tested with the anti-Daudi serum, the reactivity was equally distributed in each population. Among 13 human lymphoblastoid cell lines tested, reactivity was demonstrated on three out of four T cell lines, and on four out of nine B cell lines. The positive reacting B cell lines were derived from two African and two American Burkitt lymphomas. The antigen(s) described does not seem to be related either to human Ia-type antigens or to Epstein-Barr virus-associated antigens because these antigens are not present on fetal or adult thymocytes. Reciprocal absorption experiments indicate that this anti-Daudi serum detects the same antigenic structures present on certain subpopulations of T and B lymphocytes.

Absorption↗
PubMed1977

Reconstitution of catecholamine-sensitive adenylate cyclase activity: interaction of components following cell-cell and membrane-cell fusion.

Heterokaryons formed by the fusion of adenylate cyclase-deficient S49 cells and beta-adrenergic receptor-deficient B82 cells in the presence of cycloheximide display a catecholamine-sensitive adenylate cyclase activity. Similar complementation can be observed when receptor-replete membranes from the cyclase-deficient cell are fused with intact B82 cells. Using the cell fusion technique it can be demonstrated that the uncoupled S49 cell variant has a functional beta-adrenergic receptor but that this variant and the adenylate cyclase-deficient variant are not complementary. Hypothetically, both clones may share a common defect in regulatory components of adenylate cyclase or both may lack a specific coupling factor.

Adenylyl Cyclases↗
PubMed1978

Fluorescent labelling of cell membranes and cytoplasmic proteins in living cells.

Primary amino groups may be selectively labelled in living cell cytoplasmic components by staining with the covalently binding fluorochrome reagent fluorescamine. The reaction is extremely rapid and occurs at very low reagent concentrations. Cells survive such treatment and gradually remove or metabolize the labelled substances. Nuclei and nucleoli are not labelled, while lamellar cytoplasm, which contains little actual cytoplasm, is well demarcated, thus indicating that the method is useful for studies of cell membrane components. Labelled cell membranes can be prepared for further purification after preliminary external fixation of cell membranes with a supravital polyaldehyde fixative. The use of dimethylsulfoxide as a solvent for fluorescamine allows much longer survival of the cells than the use of acetone as a solvent. In addition, the use of high pH and borate buffer was not necessary to the labelling phenomenon.

Animals↗
PubMed1979

Human cell membrane components dominant in T cell lineage: identification and characterization of human TL-like antigens.

Cell membrane components that contain beta 2-microglobulin were purified from cells of a human T cell-type leukemia cell line, HPB-ALL. They contained membrane components that have the same molecular size and the same subunit structure as HLA(A,B,C) antigens but are separable from the typical beta 2-microglobulin-containing cell membrane components, i.e., the HLA (A,B,C) antigens, by xenoantibody reagents. A sensitive radioimmunoassay was constructed for detection of the T cell membrane components. The assay revealed that the cell membrane components are expressed exclusively on cells of T cell-type leukemia cell lines among the human lymphoid cell lines tested, predominantly in thymus, among the human organs and tissues tested. They were not present on cells of human B cell-type cell lines or on cells of nonlymphoid organs and tissues. No alloantibodies directed to the T cell membrane components, the putative human homologues of mouse TL antigens, were found in any of the human tissue typing sera tested.

Animals↗