Search PubMed⌕ Search

Biomedical subjects

G Klein

Publications and source records attributed to G Klein.

At least 1,063 records · Page 59Linked to original sources
PubMed1977

Immunization of mice with syngeneic Moloney lymphoma cells induces separate antibodies against virion envelope glycoprotein and virus-induced cell surface antigens.

Immunization of mice with heavily irradiated syngeneic Moloney lymphoma cells evokes antibodies against the major viral envelope antigen, gp71, and the Moloney virus-induced cell surface antigen (MCSA). A9HT cells, an L-cell subline, react with the antibodies against the viral envelope antigen only; this reaction can be completely inhibited by virus or purified gp71. Reactivity to Moloney lymphoma cells (YAC) was only partially inhibited (maximum 30%) or not at all. This can be attributed to the reaction of the YAC cells with antibodies directed against MCSA, a nonvirion cell surface component according to both biological and biochemical evidence. Antibody-induced capping of gp71 or p15(E) did not change the membrane distribution of MCSA or H-2, indicating that these antigens represent distinct entities on the cell surface. MCSA showed only minimal capping and thereby differed in behavior from both H-2 and virion antigens. gp71 could be capped by the mouse antiserum as revealed by subsequent staining with monospecific anti-gp71 antiserum. Under ordinary test conditions this reactivity is overshadowed by the reaction against MCSA. The lack of MCSA capping reflects a difference in anchorage of this antigen.

Antibodies, Viral↗
PubMed1977

Relationship between the Epstein-Barr virus and undifferentiated nasopharyngeal carcinoma: correlated nucleic acid hybridization and histopathological examination.

In order to examine critically the closeness of association between Epstein-Barr virus (EBV) DNA and nasopharyngeal carcinoma (NPC) a correlated histopathological and nucleic acid hybridization study was performed on 51 undifferentiated NPC, 4 NPC with some signs of squamous differentiation, 7 nasophayngeal tumors of other histological types and 14 head and neck carcinomas located outside the nasopharynx. All 51 undifferentiated NPCs contained significant numbers of EBV-genome copies per cell. Two of the somewhat differentiated NPCs were also EBV-DNA-positive, whereas 2 were negative. Of the 7 other nasopharyngeal tumors, 1 was EBV-DNA-positive. Histological examination, however, showed that this was a typical Burkitt lymphoma. The other 6 tumors were all EBV-DNA-negative lymphoproliferative malignancies. All 14 had head and neck carcinomas located outside the nasopharynx were EBV-DNA-negative. The sera of undifferentiated NPC patients had elevated antibody titers against the EBV-determined antigens, the EA (D) componet in particular. These findings confirm that there is a regular association between EBV-DNA and undifferentiated NPC.

DNA, Viral↗
PubMed1977

Membrane receptor stripping confirms the association between EBV receptors and complement receptors on the surface of human B lymphoma lines.

Complement (C3) receptors, EBV receptors, Fc receptors, membrane IgM and beta2microglobulin (beta 2m) were individually stripped from the surface of human B lymphoma lines. The cells were subsequently tested for their ability to absorb infectious EB virus. Stripping of Fc receptors, IgM and beta2m did not reduce EBV absorption. Stripping of either EBV receptors or C3 receptors eliminated or drastically reduced EBV-absorptive capacity. The results confirm the distinctive association between EBV receptors and C3 receptors on human lymphoma cells.

Burkitt Lymphoma↗
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↗
PubMed1977

Column separation of viral capsid antigen (VCA)-positive cells from VCA-negative cells in an Epstein-Barr virus (EBV)-producing lymphoid line,.

Virus producing, VCA (viral capsid antigen)-positive cells could be selectively removed from Epstein-Barr virus (EBV)-carrying, virus-producer P3HR-1 cultures by two different methods of column passage. In the first, the virus-producing cells were covered with human EBV antibody and subsequently passaged through anti-human-Ig columns. In the second methods, untreated P3HR-1 cells were allowed to pass through columns of EBV receptor-positive cell lines or, as controls, EBV receptor-positive cell lines or, as controls, EBV receptor-negative cells. The majority of the VCA-positive cells were selectively removed by both techniques. The second method involves the attachment of EBV-producer cells, known to accumulate viral envelope material in their plasma membrane, to EBV receptors. In view of recent evidence indicating an association between EBV and complement receptors, human and mouse complement were tested for their ability to block this attachment. Fresh mouse and human complement regularly exerted blocking activity, whereas heat-inactivated human serum did not block. Heat-inactivated mouse serum did block occasionally, but the effect was more irregular than with fresh mouse serum. Trypsin treatment of the EBV-receptor colum abolished its ability to retain VCA-positive cells.

Antibodies↗
PubMed1977

[Treatment of arterial hypertension with sotalol, a beta-blocker (author's transl)].

Plasma concentrations and the effect of sotalol, a beta blocker, on arterial blood pressure and other haemodynamic variables (determined by echocardiography) were measured in 15 patients with arterial hypertension of different severity, after acute administration and during long-term treatment for 3 to 16 months. Sotalol absorption was relatively constant, the correlation coefficient between plasma concentrations and administered dose being r=0.67. The biological half-life was about eight hours, The effects of the drug on blood pressure, heart rate and other haemodynamic variables were small after acute administration. But in ten patients blood pressure returned to normal during chronic treatment with sotalol alone, while in five others it was necessary to combine sotalol with a diuretic and dihydralazine. These results show that sotalol is suitable for long-term treatment of arterial hypertension.

Adult↗
PubMed1977

Tumorigenicity of human hematopoietic cell lines in athymic nude mice.

Human hematopoietic cell lines, which had been classified on the basis of studies on clonality, and morphological, chromosomal and functional parameters as lymphoblastoid cell lines (LCL) of presumed non-neoplastic origin, and lymphoma, myeloma and leukemia lines of proven malignant origin, were tested for tumorigenic potential on subcutaneous transplantation to nude mice and for capacity to grow in semi-solid medium in vitro. Recently established LCL failed to grow both in nude mice and in agarose. In contrast, some of the LCL which had developed secondary chromosomal alterations during continuous cultivation for periods exceeding several years were tumorigenic and/or had the capacity to form colonies in agarose. Most lymphoma lines formed colonies in agarose and tumors in the mice. One of the two myeloma lines formed subcutaneous tumor which, however, showed no progressive growth. The other myeloma line failed to grow. Both myeloma lines, however, formed colonies in agarose. The myeloid leukemia line was tumorigenic while two of the three tested lymphocytic leukemia lines failed to grow in the mice. All leukemia lines formed colonies in agarose. We conclude from this study that: (1) Of the two types of Epstein-Barr virus containing cell lines [LCL and Burkitt lymphoma (BL) lines], only BL lines were shown to form tumors when inoculated subcutaneously in nude mice and had the capacity to grow in agarose in vitro. This shows that EBV transformation per se does not necessarily render lymphocytes tumorigenic in nude mice. The capacity to form colonies in agarose is not acquired either. (2) Changes of the karyotype and several phenotypic characteristics which occur in the originally diploid LCL during prolonged cultivation in vitro may be accompanied by the acquisition of the potential to grow subcutaneously in nude mice and in agarose in vitro. (3) The inconsistency with regard to the capacity of come of the neoplastic cell lines to grow in nude mice or in agarose seems to underline that neither of the two tests is a reliable criterion for malignancy of human lymphoma, leukemia and myeloma cell lines.

Animals↗
PubMed1977

[Pathogenetic concept of experimental mycoplasma arthritis].

Biochemical studies of rats with mycoplasma arthritis revealed new findings in pathogenesis and pathophysiology. Mycoplasma infection which resembles rheumatoid arthritis, leads to an inhibition of the DNA-repair. We were able to proof this enzyme--kinetically and autoradiographically. We also observed for the first time the occurrence of DNA-antibodies in this type of arthritis. It is possible that there is a relation between inhibition of DNA-repair and the occurrence of DNA-antibodies. Thus mycoplasma infection seems to influence DNA-metabolism. There are interesting parallels concerning DNA-antibodies and DNA-repair between experimental mycoplasma arthritis and human systemic lupus erythematosus and rheumatoid arthritis.

Animals↗
PubMed1977

Separation of cells with different histocompatibility (H-2) antigens by passage through cellular immunoadsorbent columns.

The anti-Ig column technique of Wigzell et al. (Scand. J. Immunol. 1972. 1:75) was adapted to the separation of mouse cells with different H-2 antigens. Fractionation was achieved by a two-step procedure: first the cells were treated with anti-H-2 sera, and thereafter passed over anti-mouse Ig columns. Antibody-coated cells were selectively retained in the anti-Ig column. The method could be applied to the separation of normal mouse lymphocytes or lymphoma cells with different H-2 antigen complexes and for the selective isolation of H-2 loss variants from a mouse carcinoma/fibroblast hybrid.

Animals↗
PubMed1977

Genetic variation in antibody response and natural killer cell activity against a Moloney virus-induced lymphoma (YAC).

Antibody formation against the Moloney virus-determined surface antigen (MCSA) was found to be under genetic control. In the (A X C57BL)F1 cross one dominant gene played a major role, resulting in bimodal distribution of the antibody response. This gene showed no linkage to H-2, IgG heavy chain immunoglobulin allotype, the coat color markers B and C, and five different isozyme markers representing chromosome numbers 1, 4, 7, 8 and 9. Antibody response to MCSA was not correlated with antibody titers against the virion proteins, confirming that MCSA was an independent entity. There was no relationship between the segregation of natural killer cell activity and antibody response in a [(A X C57BL) X A] backcross population.

Animals↗
PubMed1977

Human B cell line deficient in the expression of B cell-specific glycoproteins (GP 27,35).

A human B lymphoid cell line, P3HR-1, expresses only low levels of the 27 000 and 35 000 mol.wt. B cell-specific glycoproteins (GP 27,35). Indirect antibody-binding and quantitative absorption tests with a xenoantiserum against the antigens showed that P3HR-1 cells have on their surface about 1% of the amount found on other human B lymphoblastoid cell lines. The deficit of the glycoproteins on the surface of P3HR-1 cells could be accounted for by a reduced rate of synthesis in these cells. A simple relationship between the reduced expression of GP 27,35 on P3HR-1 cells and their inability to bind Epstein-Barr virus (EBV) or express complement receptors was excluded because other B lymphoid cells which expressed neither virus-binding sites nor complement receptor had normal amounts of GP 27,35 on their surface. However, antibodies against GP 27,35 could block the absorption of EBV by EBV receptor-positive B cells.

B-Lymphocytes↗
PubMed1977

Establishment in continuous culture of a new type of lymphocyte from a "Burkitt like" malignant lymphoma (line D.G.-75).

The isolation and establishment in vitro of a hitherto undescribed type of lymphocyte designated D.G.-75 is reported. The original inoculum was derived from the pleural effusion of a child with a primary abdominal lymphoma, which clinically and histologically resembled Burkitt's lymphoma. In addition to the absence of the EBV genome and EBV receptors, this line possesses a number of other properties which distinguish it from previously described lymphoblastoid cell lines. It has different growth characteristics and morphology; does not form EAC or E rosettes (representative of B and T) cell surface markers, respectively); possesses IgM-kappa immunoglobulins on the cell surface (B lymphocyte), has an unusually high cap-forming ability and low agglutinability with fluorescent concanavalin A. One homologue of the No.14 chromosome pair possesses extra chromatin material as revealed on chromosome banding. This abnormal chromosome marker is similar to that described in biopsies and cultured tumor cells from patients with African Burkitt's lymphoma.

Agglutination Tests↗
PubMed1977

Somatic cell hybrids between human lymphoma lines. III. Surface markers.

Hybrids between two human lymphoma lines, Raji and Daudi (8A) and Raji BJAB (83) were examined for genetically determined and/or differentiation-related surface markers. HL-A B ce-l alloantigens, Fc and complement receptors, EBV receptors and beta2 microglobulin showed an autonomous ("co-dominant") expression in the hybrid. This is in contrast to most previous studies on other differentiation markers, involving as a rule crosses between cells of different lineages, where the differentiated pattern usually became "eclipsed" in the hybrid. Staining of activated complement and complement consumption tests showed intermediate or partially suppressed expression in the hybrids. This may be viewed in relation to the fact that these reactions do not merely depend on complement binding to the receptor, but also on subsequent activation and binding of the activated complement. A more complex interaction is also suggested for immunoglobulin production. Surface immunoglobulin showed a suppressive or intermediate pattern in both hybrids, whereas intracellular kappa chain production showed an amplification in the 83 hybrid. The beta2 microglobulin deficiency of the Daudi parent was corrected in the Raji/Daudi hybrid. Two new HL-A specificities,A10 and BW17, appeared on this hybrid which were not present on the parental lines. This suggests that the HL-A deficiency of the Daudi cell is due to its lack of beta2 microglobulin.

B-Lymphocytes↗