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Biomedical subjects

G Köhler

Publications and source records attributed to G Köhler.

At least 235 records · Page 13Linked to original sources
PubMed1977

Derivation of hybrids between a thymoma line and spleen cells activated in a mixed leukocyte reaction.

We have established 16 independent hybrid lines derived from a fusion between an AKR thymoma and mixed leukocyte reaction-stimulated C57BL/6 spleen cells. The hybrids express both parental H-2 alleles and show hybrid glucose-6-phosphate isomerase activity. Two of the lines showed Fc receptor activity not expressed in the parental thymoma. The AKR Thy-1.1 allele was expressed in all hybrid lines, but no Thy-1.2 could be detected. No killing activity was retained in the hybrid cells, probably because Sendai virus-mediated fusion of killer cells resulted in the lysis of the thymoma fusion partner.

Animals↗
PubMed1977

Fusion of T and B cells.

Hybrid cells were prepared by fusin an immunoglobulin-secreting mouse myeloma lin e (B cell) with an allogenic T-cell lymphoma which expresses the surface antigen Thy 1. The resulting hybrids expressed H2 antigens of both parental cells and secreted the immunoblobulin of the myeloma parent but did not express the Thy 1 antigen of the lymphoma parent. Twenty-one hybrids were formed from fusion of the same myeloma line with TNP-SRBC-primed spleen cells. Most of the hybrid lines exhibited characteristics expected for the fusion of the myeloma to B lymphocytes. No hybrids between the myeloma line and spleen T cells were identified as none of the hybrids expressed the T-cell-specific antigen Thy 1. We discuss possible reasons for failure to produce hybrids with T-cell characteristics in these types of fusion.

Animals↗
PubMed1977

[Cesarean-section narcosis using Tricuran (Gallamine as a long-lasting muscle relaxans before delivery of the infant].

The use of long term non-depolarizing muscle relaxants facilitates the carrying out of anaesthesia at caesarean section. We compared the Apgar-score of two groups of 20 newborns after caesarean section, whose mothers got only succinylcholine or succinylcholine and gallamine before delivery by a hexobarbiturate - nitrous oxide - oxygen anaesthesia. The Apgar-score was practically identical in both groups. 70% of infants of the succinylcholine group and 75% of infants of the gallamine group showed an Apgar-score between 7 and 10 after 1 minute. A later decrease was noticed in no case. The use of gallamine is without danger for the newborn.

Adult↗
PubMed1977

[Course of immunoglobulins G and M in seriously burned patients].

IgM and IgM levels were measured in 108 burn patients. A marked decrease was evident in these immunoglobulins. The initial fall of IgG can be attributed to the loss of serum via the body surface, i.e. burn blisters. The loss of IgM may be taken as indication of the catabolic phase. Quantitative substitution was possible in almost all cases.

Adolescent↗
PubMed1976

Fusion between immunoglobulin-secreting and nonsecreting myeloma cell lines.

The defects in two nonsecreting variant clones of the mouse plasmacytoma MOPC 21 (P3) were studied by tissue culture methods. The variants (NSI and NSIII) do not synthesize detectable heavy chains. NSI synthesizes, but does not secrete, light chains and NSIII does not synthesize light chain. A screening procedure was used allowing the detection of revertant cells secreting immunoglobulin. The method is based on a hemolytic plaque assay using anti-immunoglobulin-coated red cells. No revertants were detected among 2 x 10(7) cells. Both variant lines were fused to another myeloma line (PI) which secretes a complete immunoglobulin and excess light chains. Analysis of the products by isoelectric focusing showed that in the hybrids there was no reactivation of synthesis of the nonexpressed chains. The defects leading to loss of synthesis cannot therefore be complemented in the hybrid lines. The secretion of light chain in NSI, on the other hand, could be complemented in the hybrid but the light chain was only secreted as part of a new immunoglobulin hybrid molecule.

Cell Fusion↗
PubMed1976

Frequency of precursor cells against the enzyme beta-galactosidase: an estimate of the BALB/c strain antibody repertoire.

A method has been developed for detecting anti-beta-galactosidase antibodies after isoelectric focusing in thin layers of polyacrylamide gel. By "staining" with wild-type enzyme, all antibodies against beta-galactosidase are detected, while a subset of antibodies able to activate a mutant enzyme is detected by staining with that enzyme. Limiting dilutions of beta-galactosidase-primed or unprimed spleen cells of BALB/c mice were transferred together with antigen into sublethally irradiated syngeneic hosts. The limiting role of the precursor B cells has been judged by the analysis of the clonal distribution of galactosidase-specific antibodies in recipient sera. The frequency of anti-wild-type beta-galactosidase precursor cells was one in 0.42 x 10(6) in the primed and one in 0.93 x 10(6) in the unprimed spleen. The frequency of precursor cells for antibodies activating the mutant enzyme was one in 1.5 x 10(6) in the primed and one in 4.6 x 10(6) in the unprimed spleen. Therefore four and five times less anti-M (mutant) than anti-B (wild-type) precursor cells exist in the spleens of primed and unprimed BALB/c mice, respectively. Comparing 51 clones derived from one primed donor mouse, it was possible to demonstrate that at least 43 different mutant-beta-galactosidase-activating antibodies can be produced in one mouse. Comparing these 43 clones with 27 clones derived from another donor mouse, only one clone seemed to be common to both mice. From this the repertoire of the BALB/c strain has been estimated to consist of over 1000 different mutant enzyme-activating antibodies.

Animals↗
PubMed1976

Derivation of specific antibody-producing tissue culture and tumor lines by cell fusion.

Cell fusion techniques have been used to produce hybrids between myeloma cells and antibody-producing cells. The hybrid lines derived are permanently adapted to grow in tissue culture and are capable of inducing antibody-producing tumors in mice. Spleens from mice immunized against sheep red blood cells (SRBC) were fused to an 8-azaguanine-resistant clone (X63-Ag8) of MOPC 21 myeloma. Over 50% of the derived hybrid lines produce and secrete immunoglobulins different from the MOPC 21 myeloma. About 10% of the hybrid lines exhibit anti-SRBC activity. The high proportion of antibody-producing hybrids suggests that the fusion involves a restricted fraction of the spleen cell population, probably cells committed to antibody production. In order to avoid the presence of the MOPC 21 heavy chain in the specific hybrids, another myeloma cell line (NSI/1-Ag4-1) has been used. This is a nonsecreting variant of the MOPC 21 myeloma which does not express heavy chains. Three anti-SRBC (probably of the mu, gamma2b and gamma1 classes, respectively) and two anti-2,4,6-trinitrophenyl (of the mu class) antibody-producing hybrids have been repeatedly cloned. By random selection and by selection of specific clones according to their lytic activity (clone plaque selection), a number of different lines have been constructed. Such lines express different combinations of the four possible chains of each hybrid line: the myeloma gamma and K chains and the specific antibody heavy and light chains. In three cases (Sp1, Sp2 and Sp7) it is shown that only the specific H and L combination has activity and that the myeloma chains are unable to substitute for them. In most cases lines have been derived which no longer express the MOPC 21 chains but only the specific antibody chains.

Animals↗
PubMed1975

Attenuation of beta-adrenergic cardiac responses in chronically hypoxic rats with right ventricular hypertrophy.

Rats were kept for 30 days in an O2-N2-mixture of gradually reduced O2 (18 leads to 6 Vol%) and constant CO2 (0.5 Vol percent). This induces a selective hypertrophy of the right ventricle and the ratio ventricular/body weight (g/kg) increased from 0.6 to 1.4 while it remained constant in the left heart. In the right and left ventricles of control animals the contents of myocardial ATP (4.0 muM/g) and of phosphocreatine (CP) (5.8 muM/g) were the same. These values were not significantly changed by hypertrophy. In the control animals, a single test-dose of isoproterenol (30 mg/kg), subcutaneously administered 2 hr before the heart was removed, caused a diminution of the ATP-content by 15 percent in the right ventricle and by 40 percent in the left. The CP-content was reduced by 40 percent on the right and by 50 percent on the left side. In the hypertrophied right ventricle, however, there was no major decrease in ATP and CP following the isoproterenol injection. In the nonhypertrophied left heart the response to isoproterenol was still detectable but much less than normal. As the chronotropic and hypotensive effects of isoproterenol were also lessened in the hypoxic animals it is concluded that a general reduction in the responsiveness to beta-adrenergic stimulation has occurred.

Animals↗