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Biomedical subjects

A Ziegler

Publications and source records attributed to A Ziegler.

At least 343 records · Page 19Linked to original sources
PubMed1980

Rapid preparation of multiple cell samples for immunofluorescence analysis using microtiter plates.

A method is described which allows incubation, washing and staining of cells for immunofluorescence analysis to be carried out in microtiter plates. Comparison of this procedure with the conventional protocol, carried out on normal and leukemic human peripheral blood cells, reveals 5 major advantages. (1) Only 2.5 X 10(5) viable cells are needed for testing a particular antiserum. (2) The amount of reagents needed is 1/4 of that used in the conventional method. (3) Damage to cells is reduced to a minimum by shorter processing times and gentler centrifugation steps. (4) A large number of samples can be processed at the same time in an identical and reproducible manner. (5) The cost of an experiment is considerable reduced.

Antibody Specificity↗
PubMed1980

Accumulation of drugs by guinea pig isolated atria. Quantitative correlations.

The time course of the tissue accumulation of 16 neutral, cationic, and anionic drugs by resting and 2-Hz stimulated atria of the guinea pig was measured. The accumulation of the substances was quantified by means of their tissue to medium ratios (T/M). Auricles driven with 2 Hz accumulated the drugs faster and during a long period of time to a greater extent than resting atria. By extrapolation of the binding characteristics, the final equilibrium T/M values were estimated. The variance in these accumulation data at equilibrium (log T/M) Could be best described by a linear combination of log P (octanol/water) and the ability of the drugs to bind to atrial homogenate (log percent bound/percent free). A parameter calculated from protein binding appeared less significant. Comparable results were obtained for the accumulation data measured in resting and 2-Hz stimulated atrial muscles. It is suggested that the degree of accumulation of drugs into atrial tissue is determined by the facility of their penetration of the plasma membrane and the extent of their intracellular binding.

Animals↗
PubMed1980

Studies on biosynthesis, assembly and expression of human major transplantation antigens.

Biosynthesis and regulation of expression of transplantation as detected by a monoclonal antibody to HLA-A,B,C antigens (human leucocytic antigen) and a polyclonal antiserum to beta 2-microglobulin have been investigated using radioactive amino acids and sugars to label human lymphoid cells. We found unbalanced synthesis of HLA heavy chains and beta 2-microglobulin, the latter being in excess and secreted to the extracellular medium. In DAUDI cells, which are defective in beta 2-microglobulin, no HLA-A,B,C could be detected intracellularly even in the presence of added beta 2-microglobulin. Treatment of BRI-8 cells with tunicamycin, an antibiotic which inhibits glycosylation of polypeptides, almost had no effect on the levels of beta 2-microglobulin, while it markedly decreased that of HLA heavy chains, both on the cell surface and intracellularly. Glycosylation of the HLA heavy chains appeared to be an essential requirement for the normal expression of HLA-A,B,C antigens. The translation in vitro in a messenger-dependent reticulocyte system with total polysomes obtained from BRI-8 cells showed that beta 2-microglobulin was synthesized as a precursor. This larger polypeptide was converted into mature beta 2-microglobulin when protein synthesis was performed with microsomes instead of polysomes.

Beta-Globulins↗
PubMed1980

[Clinical use of lyophilized dura in diaphragmatic defects].

A short survey about pathology and clinic of diaphragmatic defects and injuries is given. The different operative possibilities of plastic diaphragmatic defect surgery are discussed. Direct, autoplastic, alloplastic and homoioplastic closure of diaphragmatic defects are used today. We report about two patients. In both cases we used lyophilized human dura for closing the diaphragmatic defect with success.

Aged↗
PubMed1979

Accumulation of drugs by resting or beating cardiac tissue.

The rate and degree of accumulation of 12 neutral, anionic and cationic drugs were studied in resting and 2 Hz-stimulated isolated left auricles of the guinea pig. The uptake process was accelerated in muscles driven electrically. The time needed to reach equilibrium was related to the extent of accumulation which in turn corresponded with the lipophilicity of the drug. The frequency-induced changes in the kinetics of the accumulation disappeared under reduced mechanical activity of the muscle. It is suggested that the increased mechanical activity enhances drug disposition within the extracellular space, so that more drug is available for transmembrane penetration.

Animals↗
PubMed1979

[Clinical experience in 80 patients with intramedullary trochanteric nailing].

Report on the clinical experience in 80 patients with the intramedullary trochanteric nailfixation according to KUNTSCHER of pertrochanteric, or subtrochanteric femur fractures. This procedure in our opinion enlarges the operative methods for treatment of fractures of the trochanteric region in elderly patients with a high operative risk.

Aged↗
PubMed1979

[Importance of hormones and free fatty acids in the pathogenesis of carbohydrate metabolic disorders in myocardial infarct].

The increase in the content of the somatotropic hormone and cortisol in blood plasma as well as the increase in the content of free fatty acids in serum in the acute period of myocardial infarction are more marked in patients with impaired tolerance than in those with normal tolerance. The authors believe that free fatty acids are of utmost importance among the factors causing the development of insulin resistance in patients with acute myocardial infarction. Their increased concentration is due to hypersecretion of catecholamines, somatotropic hormone, and cortisole.

Acute Disease↗
PubMed1978

Production of monoclonal antibodies to group A erythrocytes, HLA and other human cell surface antigens-new tools for genetic analysis.

Antibody-secreting hybrid cells have been derived from a fusion between mouse myeloma cells and spleen cells from a mouse immunized with membrane from human tonsil lymphocyte preparations. Hybrids secreting antibodies to cell surface antigens were detected by assaying culture supernatants for antibody binding to human tonsil cells. Six different antibodies (called W6/1, /28, /32, /34, /45 and /46 were analyzed. These were either against antigens of wide tissue distribution (W6/32, /34, and /46) or mainly on erythrocytes (W6/1 and W6/28). One of the anti-erythrocyte antibodies (W6/1) detected a polymorphic antigen, since blood group A1 and A2 erythrocytes were labeled while B and O were not. Antibodies W6/34, /45 and /46 were all against antigens which were mapped to the short arm of chromosome 11 by segregation analysis of mouse-human hybrids. Immunoprecipitation studies suggest that W6/45 antigen may be a protein of 16,000 dalton, apparent molecular weight, while W6/34 and /46 antigens could not be detected by this technique. Antibody W6/32 is against a determinant common to most, if not all, of the 43,000 dalton molecular weight chains of HLA-A, B and C antigens. This was established by somatic cell genetic techniques and by immunoprecipitation analysis. Tonsil leucocytes bound 370,000 W6/32 antibody molecules per cell at saturation. The hybrid myelomas W6/32 and W6/34 have been cloned, and both secrete an IgG2 antibody. W6/32 cells were grown in mice, and the serum of the tumor-bearing animals contained greater than 10 mg/ml of monoclonal antibody. The experiments established the usefulness of the bybrid myeloma technique in preparing monospecific antibodies against human cell surface antigens. In particular, this study highlights the possibilities not only of obtaining reagents for somatic cell genetics, but also of obtaining mouse antibodies detecting human antigenic polymorphisms.

Antibody Formation↗
PubMed1978

Monoclonal antibodies as probes for differentiation and tumor-associated antigens: a Forssman specificity on teratocarcinoma stem cells.

A set of monoclonal antibodies derived by fusing P3-NS1/1-Ag4-1 myeloma cells with spleen cells from a rat immunized with mouse spleen were screened for activity against a tumor cell panel. One of these antibodies was found to react only with mouse embryonal carcinoma cells and no other tumor cell type tested, including differentiated derivatives of teratocarcinomas. In the adult mouse, this antigen is expressed by subpopulations of cells in the spleen, bone marrow, lymph node, brain, kidney and testes, although not in liver and thymus. This antigen has a species and tissue distribution consistent with that of Forssman antigen. The molecules which carry this specificity on the embryonal carcinoma cells appear to be glycolipids.

Antibodies↗