Search PubMed⌕ Search

Biomedical subjects

M Schachner

Publications and source records attributed to M Schachner.

At least 487 records · Page 27Linked to original sources
PubMed1977

Expression of nervous system antigen-3 by lines of mouse fibroblasts and kidney cells and continued expression in hybrid cells.

In a survey of the expression on cultured mouse cells of the cell surface antigen known as nervous system antigen-3 (NS-3), it was found that RAG, a renal adenocarcinoma line, expressed that antigen. It was also observed that 3T3, a fibroblast line of unknown tissue origin, expressed NS-3. Cells of these two lines were hybridized with cells of two mouse L cell lines that did not express NS-3. Four hybrid clones were tested for both the 3T3 X L cell cross and the RAG X L cell cross, and all the hybrids were found to be NS-3 positive. All the hybrids had at least 40% as much activity as the NS-3 positive parent. Of the four parental mouse cell lines used, only 3T3 expressed Thy-1.2 antigen on the cell surface. In contrast to the continued expression of NS-3 on hybrid cells, Thy-1.2 antigen was not detectable on two clones of 3T3 X L cell hybrids that were tested.

Adenocarcinoma↗
PubMed1977

Ultrastructural localization of glial fibrillary acidic protein in mouse cerebellum by immunoperoxidase labeling.

Glial fibrillary acidic protein was localized at the electron microscope level in the cerebellum of adult mice by indirect immunoperoxidase histology. In confirmation of previous studies at the light microscope level, the antigen was detectable in astrocytes and their processes, but not in neurons or their processes, or in oligodendroglia. Astrocytic processes were stained in white matter, in the granular layet surrounding synaptic glomerular complexes, and in the molecular layer in the form of radially oriented fibers and of sheaths surrounding Purkinje cell dendrites. Astrocytic endfeet impinging on meninges and perivascular membranes were also antigen positive. In astrocytic perikarya and processes, the immunohistochemical reaction product appears both as a diffuse cytoplasmic label and as elongated strands, which by their distribution and frequency could be considered glial filaments.

Animals↗
PubMed1977

Immune responses to mouse neuroblastoma C1300. I. Preliminary observations on cell-mediated immune responses.

In vitro cell-mediated cytotoxicity (CMC) for [3H]proline-labeled target cells was demonstrated with the use of unfractionated populations of regional lymph node, spleen, and peritoneal cells (RLNC's, SPC's, PC's, respectively) from C57BL/6 and strain A mice. Syngeneic and allogeneic hosts were immunized sc or ip with C1300 tumor or syngeneic SPC's. The syngeneic and allogeneic host effector lymphoid cells showed various degrees of cytotoxicity for C1300 target cells 3-9 days after one immunization with C1300, whereas the effector lymphoid cells of hosts immunized with syngeneic SPC's generally showed less CMC for C1300 and frequently increased the growth of C1300 target cells when compared to C1300 targets plus media controls. Effector cells obtained from lymphoid organs in the region nearest the immunization (i.e., RLNC from sc-inoculated hosts) demonstrated significantly more CMC than did effector cells from more remote lymphoid organs. The PC's and SPC's of C1300 ip hyperimmunized allogeneic hosts produced greater CMC than did those of mice immunized once. This was not observed if syngeneic C1300 or SPC's were used as hyperimmunizing antigens. The CMC of nonimmunized host effector lymphoid cells for syngeneic labeled target cells was demonstrated.

Animals↗
PubMed1977

Partial characterization of nervous system-specific cell surface antigen(s) NS-2.

Partial biochemical characterization of several neural tissue specific antigens isolated from a murine glioblastoma cell line was accomplished by means of radioiodination of intact cells followed by immunoprecipitation of the cell lysate with a rabbit serum specific for neural tissue antigens. Polyacrylamide gel electrophoresis of the immunoprecipitate in sodium dodecyl sulfate resolved the labeled antigens into several major components: two proteins (or glycoproteins) having apparent m.w.'s of 84,000 and 120,000 and lipid associated components which may be heterogeneous. The protein and lipid associated components apparently possess independent antigenicity because after chloroformmethanol extraction the protein components can be immunoprecipitated from the aqueous phase and the lipid associated component can be immunoprecipitated from the organic phase. Despite their independent antigenicity it is not known whether the components may be noncovalently associated on the cell surface. Although some of these antigens can be isolated from brain or glioma cells (a related tumor), non can be demonstrated in lymphoid tissues or C1300 neuroblastoma cells using identical methods. Therefore, these studies confirm our previous findings concerning the specificity of the anti-NS-2 antiserum by using cytotoxicity tests.

Animals↗
PubMed1976

Nervous system antigen-5, an antigenic cell surface component of neuroectodermal origin.

The antigenic cell surface component NS-5 (nervous system antigen-5) is recognized by antiserum raised in C3H.SW/Sn mice against cerebellum of 4-day-old C57BL/6J mice. When analyzed in the cytotoxicity test the antiserum detects a cell surface antigen or set of antigens present not only an cerebellum but also other parts of the central nervous system, including retina, as well as on mature spermatozoa and to a lesser degree on kidney. All other non-neural tissues tested, liver, splee, thymocytes, muscle, testis, adrenal gland and epidermis do not express detectable amounts of the antigen. Among seven murine tumors of the nervous system, medulloepithelioma shows high levels of NS-5 expression, whereas neuroblastoma Cl300, glioma G26, glioblastome, ependymoblastoma, ependymoblastoma EPA and glioblastoma G26l do not carry detectable NS-5. All mouse strains tested (C57BL/6J, C3H.SW/Sn, C3H/HeDiSn, A/J, AKR/J, BALB/cJ and DBA/2) express similar levels of NS-5. The antigen is demonstrable not only on postnatal day 4 neural tissue, but also in lower amounts on adult nervous system. On embryonic day 9, the earliest stage tested, and at all subsequent stages during embryonic development, NS-K is already present in brain and spinal cord, but not in gut.

Age Factors↗
PubMed1976

Central nervous system antigen (NS-5) and its presence during murine ontogenesis.

An antiserum raised by immunization of C3H.SW/Sn mice with cerebellum from 4-day-old C57BL/6J mice recognizes a cell surface component(s) [NS-5] present in different degrees on various parts of the mouse central nervous system. When analyzed by an antiserum- and complement-mediated cell cytotoxicity test and by the ability of various tissuesto absorb anti-NS-5 antiserum activity, the antigen(s) was detectable on cerebellum, retina, olfactory bulb, cortex, basal ganglia, and medulla but not on nonneural tissues with the exception of mature spermatozoa and 4-day-old kidney. The antigen(s) detected by the anti-NS-5 antiserum was found in similar quantities on young and adult rat and mouse cerebellum; however, it was not detectable on any of 16 clonal cell lines derived from the rat central nervous system. During preimplantation stages of murine development, the antigen could be detected on all cells of (2-4)-cell and (8-16)-cell stages and on the trophoblastic cells of blastocysts by indirect immunofluorescence, Embryos on day 9 of gestation, the earliest tested after implantation, expressed the antigen(s), but expression was restricted to the nervous system.

Animals↗
PubMed1976

Biochemistry of the filaments of brain.

Intermediate filaments-cytoplasmic filaments with a diameter of 8-9 nm-have been described in a large variety of cell types. In this study, the subunit protein of the neurofilament and the presumptive subunit of the astroglial filament are compared by immunological and biochemical methods and are found to be very similar. Strong crossreactions are also found between these proteins in a variety of mammalian species. These results suggest that the intermediate filaments may, like microtubules and microfilaments, represent a highly conserved and widely distributed fibrous protein system.

Animals↗
PubMed1975

Biochemically differentiated mouse glial lines carrying a nervous system specific cell surface antigen (NS-1).

Six biochemically differentiated clonal lines have been established from a transplantable glioma (tg26) of the C57BL/6 inbred mouse strain. Antibodies have been previously raised against G26 tumor cells, which define a cell surface component(s), NS-1 (nervous system antigen-1), found exclusively in the nervous system. NS-1 concentrations approximate the levels of the original G26 tumor when the clonal lines are grown as clonal tumors in vivo, but are reduced when the cells are grown in vitro. NS-1 concentrations are further reduced in vitro upon incubation of the cells with 1 mM dibutyryl 3:5-cyclic AMP. H-2 histocompatibility antigen concentration, in contrast, is unaffected by dibutyryl cAMP. In addition to expressing NS-1, the neuroectodermal origin of these cell lines is further confirmed by their synthesis of the nervous system specific acidic protein S-100 and by the high specific activity of the enzyme 2:3-cyclic nucleotide 3-phosphohydrolase. In addition, they respond to catecholamines by the elevation of intracellular 3:5-cyclic AMP levels. Whereas expression of S-100 protein is high under in vitro conditions but negligible after one passage in vivo, 2:3-cyclic nucleotide 3-phosphohydrolase is not detectable in vitro but becomes detectable again in vivo. The two membrane-bound constituents, NS-1 and 2:3-cyclic nucleotide 3-phosphohydrolase, therefore seem to be subjected to different regulatory mechanisms from that of the soluble, intracellular S-100 protein.

Animals↗
PubMed1974

NS-1 (nervous system antigen-1), a glial-cell-specific antigenic component of the surface membrane.

A methylcholanthrene-induced glioblastoma of the C57BL/6 inbred mouse strain was used to raise antibodies in C57BL/6 and C57BL/10 inbred mice and in (C57BL/6 x DBA/2) and (C57BL/6 x Balb/c) F(1) hybrids. When examined by the cytotoxicity test, these antibodies define a cell-surface component (or components) found exclusively on brain tissue of all mouse strains studied and of several other mammalian species including man. The antigen, named NS-1 (nervous system antigen-1), is present on cells of three of the four mouse-glial-cell tumors tested, but not on the C1300 neuroblastoma, a tumor of neuronal origin. NS-1 occurs in higher concentration in regions of the nervous system richer in white than in gray matter, and in lower than normal concentrations in brains of myelindeficient neurological mutant mice. The concentration of NS-1 gradually increases postnatally and reaches the adult level between the third and fourth week. The existence of more than one allele or genetic locus controlling NS-1 activity is suggested by the occurrence of higher amounts of NS-1 in brains of the A and C57BL/6 than of the Balb/c and DBA/2 mouse strains. NS-1 is the first cellsurface component to be described that is not only unique to nervous tissue, but specific for glial cells.

Age Factors↗