Search PubMed⌕ Search

Biomedical subjects

G Klein

Publications and source records attributed to G Klein.

At least 793 records · Page 44Linked to original sources
PubMed1982

High-resolution analysis of chromosome markers in Burkitt lymphoma cell lines.

Using a high-resolution chromosome banding technique, which provided more elongated and distinctly banded chromosomes, some new evidence was obtained for localization of break points in Burkitt lymphoma marker chromosomes. As a result, the characteristic translocation between chromosomes 8 and 14 was designated as t(8;14) (q24.1;q32.5) and the deletion of chromosome 15 was designated as del(15) (q13q15).

Burkitt Lymphoma↗
PubMed1982

Different T-cell subtypes are associated with pathologically distinct forms of Moloney leukemia virus (M-MuLV)-induced lymphoma.

The T-cell enzyme markers, terminal deoxy-nucleotidyltransferase (TDT) and 20 alpha hydroxysteroid dehydrogenase (20 alpha SDH), were used to classify lymphomas induced by the Moloney leukemia virus (M-MuLV). Different subtypes of T cells were shown to be involved in different types of lymphoma. Thymomas were TdT-positive and grew as subcutaneous solid tumors at the site of inoculation. Spleen cells from mice with generalized lymphoma were of two types. In the majority of cases the lymphomas consisted of 20 alpha SDH-positive cells that homed to spleen and lymph nodes upon transplantation. In a few cases the cells of enlarged spleens were TdT-positive and, like the TdT-positive thymomas, could be transplanted as subcutaneous tumors. Thus, TdT-positive and 20 alpha SDH-positive T-cell lymphomas can be distinguished by their homing properties. Preleukemic thymus cells from M-MuLV inoculated mice can, after transfer to 400 -R irradiated syngeneic hosts, induce new lymphomas by virus release or grow in an autonomous fashion in the recipients. Whether of donor or recipient type, these lymphomas are TdT-positive. In contrast, preleukemic bone marrow cells give lymphomas of donor type which are as heterogeneous for T-cell enzymes as are lymphomas induced by neonatal inoculation of M-MuLV.

20-Hydroxysteroid Dehydrogenases↗
PubMed1982

Epstein-Barr virus (EBV) receptor implantation onto human B lymphocytes changes immunoglobulin secretion patterns induced by EBV infection.

Mosaic membrane vesicles containing both Epstein-Barr virus (EBV) receptors and Sendai virus envelope proteins were allowed to form by the previously described membrane solubilization and co-reconstitution technique. The vesicles were allowed to fuse with the membranes of normal human B lymphocytes, whereafter the cells were infected with transforming EBV (B95-8 substrain). Compared to similarly infected but otherwise unmanipulated cells, the receptor-implanted lymphocytes responded with a larger number of EBV-determined nuclear antigen positive and immunoglobulin-secreting plaque-forming cells (PFC). Moreover, there was a clear increase of the IgG/IgM PFC ratio in the receptor-implanted B lymphocytes. These results show that not all human B lymphocytes that can potentially be activated by EBV express functional EBV receptors. B lymphocytes programmed to secrete IgG appear to be more defective in this respect than IgM secretors.

Antibody-Producing Cells↗
PubMed1982

Cytogenetic replication studies on murine T-cell leukemias with special consideration to chromosome 15.

Chromosomal replication was studied by means of the BrdU-Höchst-Giemsa-technique in three minute T-cell leukemias with special regard to chromosome 15. In all the three leukemic cell lines the normally early replicating band 15 E was undetectable whereas late replication in this region is completely unaltered. Furthermore, R-banding, the structural homologue of early replication banding, remains unchanged. This observation is interpreted as a shift in the time point of replication during the S-phase of region 15 E, though the exact timing of replication of this region in tumor chromosomes remains unresolved.

Animals↗
PubMed1982

[Advantages and disadvantages of regional anesthesia in comparison with general anesthesia].

The advantages and disadvantages of different anaesthetic techniques are based upon important premises, such as specific effects on the vital functions of the organism, the relationship of these effects to the general condition of the patient, the specific risk of complications due to a particular anaesthetic technique and the decision of the patient. Only with these points in mind can advantages and disadvantages of the different anaesthetic techniques be determined respective to the individual cases. The choice of a suitable anaesthetic technique should depend upon this determination.

Anesthesia, Conduction↗
PubMed1982

Human T cell growth factor (TCGF) produced by repeated stimulation of non-adherent human lymphocytes.

T cell growth factor (TCGF) has become a valuable means of maintaining T lymphocytes in long-term culture and of studying T cell function. Numerous problems have been met in the production of TCGF of consistently good quality and in the maintenance of human T cell lines over long periods. We have investigated optimal conditions for TCGF production, and simplified assay systems for TCGF activity. The best TCGF production was obtained by short-term treatment with high concentrations of phytohemagglutinin (PHA). The TCGF producing lymphocytes could be re-used for TCGF production up to 1 month after the first treatment course. Human cultured T cell lines, fresh lymphocytes, short-term PHA stimulated lymphocytes and cultured marmoset T lymphocyte lines were all used for assay of TCGF. We recommend PHA stimulation of human lymphocytes for this assay on a routine basis, comparing results with a standard TCGF batch and calculating a growth index. Adherent cells impair TCGF production. Optimal TCGF production was seen when lymphocyte preparations without adherent cells from different donors were used.

Animals↗
PubMed1982

Detection and characterization of EBV antigens by micro-ELISA and chromatofocusing.

A micro-ELISA technique was developed for the detection of Epstein-Barr virus (EBV)-determined antigens. The enzyme-linked immunosorbent assay (ELISA) was applied with peroxidase-protein A to detect the antigens adsorbed to micro-ELISA plates. Human and rabbit antisera containing antibodies to known EBV components were used as reagents. The early antigen (EA) complex, associated with the viral cycle, was readily detected in extracts of n-butyrate- or n-butyrate + TPA-induced cells. The nuclear antigen, EBNA, could be unequivocally detected only after the partial purification of the antigen by DNA cellulose chromatography. EA (and VCA) could be separated by chromatofocusing of induced cell extracts into several fractions detected by the micro-ELISA technique. This indicates that the purification of individual antigens of the EA complex can be monitored by ELISA.

Animals↗
PubMed1982

Hybrid resistance against a natural killer (NK) cell-resistant lymphoma (YWA) is mediated by a T cell-dependent mechanism.

Rejection of the Moloney virus-induced YAC lymphoma of strain A origin by semisynegeneic F1 hybrids has previously been shown to correlate with the levels of natural killer (NK) cell activity in the same F1 hybrids against this target cell line in vitro. In the present study, YAC and another Moloney virus-induced lymphoma,, YWA, derived from the A congenic A.SW strain, were tested for F1 hybrid resistance after s.c. inoculation of small numbers of cells into syngeneic and semisyngeneic F1 mice. While YAC cells invariably grew progressively once they formed a palpable tumor, regression of YWA tumors was frequently observed in both susceptible and resistant genotypes. The hybrid resistance pattern for YAC and YWA differed in one important respect: outcross of the syngeneic host to the A-congenic A.BY strain introduced a strong H-2b-associated resistance factor against YWA, but not against YAC. Compared to YAC, which is highly NK-sensitive and rapidly eliminated from mice with high NK activity, YWA was insensitive to NK-mediated lysis in vitro and [125I] UdR-labelled YWA cells were not eliminated more efficiently from the highly resistant (A.SW X A.BY) F1 then from the parental strain in short-term (4-18h) in vivo rejection assays. It was therefore concluded that the H-2b-associated resistance against YWA was independent of NK cells or other rapidly acting effector mechanisms. Moreover, thymectomy, followed by irradiation and fetal liver reconstitution, completely abolished the resistance against YWA but left the resistance against YAC virtually intact. These data suggest that two lymphomas induced by the same agent can be rejected by different effectors. The NK-resistant YWA lymphoma is rejected by a T-dependent mechanism, while the resistance against the inoculation of the highly NK-sensitive YAC line is T-independent and, in all probability, mediated by NK cells.

Animals↗
PubMed1982

Decreased sensitivity of immunoselected and NK-selected YAC lymphoma sublines to hybrid resistance in vivo.

Two sublines of the Moloney lymphoma YAC, selected by alternating in vitro exposure to anti-MCSA + complement and in vivo passage in preimmunized hosts, had a decreased or undetectable expression of MCSA. These 'immunoselected' sublines were compared with the original YAC line with regard to their ability to grow in a panel of semisyngeneic F1 hybrids. Natural hybrid resistance to YAC, previously found to be mediated by NK cells, affected the immunoselected sublines to a much smaller extent. This was further corroborated by the fact that the same sublines showed a decreased sensitivity to the in vitro lysis by NK cells from the same hybrid genotypes. Another set of YAC variants were produced by repeated in vitro exposure to NK cells and intermittent passage in highly NK-active F1 hosts. These 'NK-selected' sublines showed a permanently decreased sensitivity to NK lysis after 8-10 selections. When compared for in vivo growth with the parental YAC-1 tissue culture line in a spectrum of relatively resistant F1 hybrids, they had an increased frequency of takes. This is in line with recent findings which show a relationship between the target site for natural antibodies and anti-MCSA on the one hand, and between the natural antibody-binding site and the NK target site on the other.

Animals↗
PubMed1982

Truncated mu chain in a Burkitt lymphoma line (P3HR-1) and its fate in various hemapoietic somatic cell hybrids.

Hybrids obtained by the fusion of PUT, an ouabain and TG-resistant subline of the Burkitt lymphoma(BL)-derived P3HR-1 line, with hemopoietic cells of various differentiation types were tested for their membrane and intracellular immunoglobulin expression. PUT cells carry no membrane immunoglobulin, but contained intracellular 61K mu chain and kappa chain. The PUTKO-1 hybrid, derived from the fusion of PUT with the erythroleukemia line K562 contains no detectable immunoglobulin. NAMPUT, a hybrid between PUT and the IgM-lambda-producing BL line Namalwa, synthetizes cellular mu, lambda and kappa chains, but its surface-Ig is exclusively mu-lambda. Two different mu chains could be detected, both precipitated by either anti-mu or anti-lambda sera. Immunoprecipitation with anti-kappa precipitated neither kappa nor mu. PUTRAL was derived by fusing PUT with Rael, an unusual surface-IgG-lambda-carrying BL line. In this hybrid, the ability to synthesize gamma and lambda chains has been eclipsed, but two mu chains are present: one corresponding to the truncated 61K chain of PUT, and a normal-sized 74K. Between 20 and 30% of the cells stain for surface IgM.

Autoradiography↗