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K J Halbhuber

Publications and source records attributed to K J Halbhuber.

At least 109 records · Page 6Linked to original sources
PubMed1980

[Immunological and enzymatical activity after dimiimidoester fixation (author's transl)].

The paper is concerned with the capability of diimidoesteras as histochemical fixatives. findings of diimidoester-fixed human erythrocytes show the receptor activity these cells had retained. Due to these properties amidinated red cells proved well suited as storable immunosorbens for ensuing tests of haemagglutination. Following immunisation with horseradish peroxidase of rats, diimidoester-fixed plasma cells were highly reactive towards HRP in contrast to only moderately stained glutaraldehyde fixed cells.

Animals↗
PubMed1980

[Conformation preserving methods of fixation (author's transl)].

For immune- and enzymehistochemical studies it is necessary to preserve biological activities of fixed cells and tissues. Aldehyde fixed biological materials give not in all cases results to provide for the needs in histochemistry, because aldehydes depressed by conformational changes of macromolecules strongly their antigen-, antibody- and enzyme-activity. Thus, it is successful a fixation by mild cross linking fixatives. Carbodiimides, diimidate compounds as well as other bifunctional reagents are excellent reagents, which can preserve in the most parts the genuine biological peculiarities of the cells. Several examples of their histochemical employment are introduced and are further discussed.

Animals↗
PubMed1979

Rat endo- and mesothelium lack Fc receptors.

The present study is concerned with the interaction of rat endo- and mesothelium with homologous erythrocytes under various conditions of pretreatment and incubation. Its findings show rat endo- and mesothelial cells a) nonadhesive to native or pretreated erythrocytes irrespective of the presence of gamma-globulin in the medium, b) devoid of primary or cryptic receptors sensitive to the Fc segment of the IgG molecule, and c) provided with binding sites at the oxidized glycocalyx which together with receptor groups of modified erythrocytes share the same class of IgG.

Agglutination↗
PubMed1979

[Electron microscopic autoradiography on semithin sections (author's transl)].

The present study applies semithin sections for electron microscopic autoradiography. Due to (a) the decrease of exposition time, and (b) lower intensity of isotope labelling, low power electron microscopic autoradiography on semithin sections is favoured in comparison with conventional (ultrathin section high power) electron microscopic autoradiography, and due to (c) more precise localization of silver granules, and (d) ease of quantitative evaluation of autoradiography, it is superior to ordinary (thick section) light microscopic autoradiography.

Animals↗
PubMed1979

[Sialic acid content and IgG binding of the glycocalyx of preserved erythrocytes].

Fractions of light and heavy erythrocytes were separated by centrifugation from blood samples banked in ACD-AG medium at 4 degrees C for periods up to 6 weeks. Both light and heavy erythrocytes have lost about 4,9% of their content of sialic acids during banking for 6 weeks. This reduction is in accord with a 6%-decrease of their agglutination by means of alcian blue. It is, however, a variance with the inhibition of agglutination by anti-IgG sera. The present findings provide evidence for the role alterations of the red cell membrane may play in the process of recognition and phagocytosis of banked erythrocytes. With regard to these alterations we suggest two types of rapid elimination of transfused banked erythrocytes: a) Primary elimination refers to cells primarily loaded with immunoglobulins such as to get recognized and phagocytized by macrophages. b) Secondary elimination accounts for rigid erythrocytes suffering from additional degradation while retained in the spleen prior to their loading with immunoglobulins and ensuing phagocytosis. Secondary elimination is considered a process more relevant to reutilisation of banked blood.

Binding Sites, Antibody↗
PubMed1978

[Accumulation of phosphate ions in biological materials, phosphate ion diffusion and electron microscopical investigations of phosphohydrolases (author's transl)].

Isolated unfixed nuclei of mouse liver accumulate different amounts of phosphate ions dependent on pH, temperature and concentration of phosphate ions. At 37 degrees C and pH = 7.2, 8.5 X 10(9) binding places and a stability constant of 2.0 +/- 0,5 . 10(4) l/mol were calculated, the data at 30 degrees C and pH = 6.5 are 4 X 10(9) Nucleus-1 and 6 X 10(3) l/mol. Nuclei fixed by formaldehyde-ethanol or glutaraldehyde do not accumulated phosphate ions. Under conditions of nearly undisturbed diffusion phosphate ions taken up by the nuclei and precipitated by the help of lead ions are detected electron microscopically in the nuclear envelope, preferently in intracisternal space. Nucleoprotein structures do not show enrichments of crystals. These structures are also not stained after precipitation of phosphate ions under conditions of diminuation of diffusion. A possible mode of phosphate binding in cell nuclei and the influence of adsorbed phosphate ions on localization of enzymatic activities are discussed.

Animals↗
PubMed1978

[Environmentally dependent erythrocyte membrane permeability as a source of error in the determination of hematocrit].

The volume of human red blood cells (RBC) was evaluated by means of the centrifugation method (hematocrit) and 131-J-labelled human serum albumin, respectively. Both of the methods yielded an identical volume of about 107 micron3 of the single RBC, provided the evaluation was performed in autologous plasma. Contrary to the 131-J-albumin method the results of which were found independent of various pretreatments of RBC, the centrifugation hematocrits of RBC previously washed with PBS and resuspended in PBS or saline protein media resulted in a mean cell volume of about 86 micron3. The decrease of the cell volume was associated with an efflux of K+ ions. If the RBC are centrifuged at 800 g instead of 15000 g, their volume will remain unchanged. The assessment of cytodeformability has shown, that RBC in PBS by loss of cell volume could enter a 2.3 micron micropipette completely. RBC in plasma, though traversing a 2.9 micron micropipette were incapable of entering a 2.3 micron channel completely. With pressures ranging from 300 to 350 mm H2O the processes of these cells undergo microspherulation.

Cell Membrane Permeability↗
PubMed1978

Glutaraldehyde mediated echinocyte/discocyte transformation is Ca2+ dependent.

Echinocytes, which were produced from freshly banked blood by repeated washes in phosphate buffered saline, undergo a transformation to the discoid shape within less than 30 seconds of incubation in isotonic 0.05% glutaraldehyde pH 7.4. This echinocyte/discocyte transformation is not associated with a change of cell volume or critical hemolysis volume although a slight decrease of cellular deformability and a 4-8 fold increase of K+ efflux within 1 hour after glutaraldehyde incubation provide evidence of the fixative's attack on the cell membrane. Trypsination prior to the incubation in isotonic glutaraldehyde could not inhibit the shape change. Hypertonic glutaraldehyde solutions partially prevent the E/D transformation with regard to both the osmolarity of the medium and the permeability of the cell membrane. The glutaraldehyde stimulated transformation is entirely inhibited in the presence of a chelating agent the efficiency of which is overcome by addition of a more-than-equivalent amount of Ca2+. The mutual action of either agent is discussed, however, the mechanism of the phenomenon remains unclear.

Aldehydes↗
PubMed1977

Reversible conformational changes of plasmalemmal glycoproteins.

Repeated incubations of human red blood cells in low ionic isotonic sucrose result in an instantaneous agglutination. In the same medium which had caused the agglutination, erythrocytes completely disagglutinate within 60 to 90 min. Disagglutination is accompanied by the efflux of cellular ions, which causes a 500-fold increase of extracellular K+. Decomposition of agglutinates occurs at once upon addition to the medium of about 3 mM KCL. It will be inhibited for hours, if the medium is renewed twice an hour. Erythrocytes washed successively with phosphate buffered saline and isotonic sucrose are devoid of adhering blood plasma proteins. If these cells were fixed with glutaraldehyde in isotonic sucrose they had lost a) their anisotropic staining with toluidine blue, and b) most of their colloidal iron binding capacity. The staining with ruthenium red and the electrophoretic velocity of these erythrocytes apparently were identical with the controls. The findings are considered evidence of the reversible unfolding of glycocalyx glycoproteins in the low ionic medium.

Animals↗
PubMed1977

[Agglutination of the red blood cells after experimental glycolytic alteration].

The present findings proved Alcian Blue as hemagglutinin suitable for the specific demonstration of negatively charged sites of the cell surface. Erythrocytes with reduced surface charge because of previous trypsination or desialization exhibited decreased Alcian Blue agglutination. On the other hand, Alcian Blue agglutinates more intensely red blood cells with a high surface charge (reticulocytes). Findings with A antiserum or the lectins prepared from Lens culinaris and Helix pomatia indicate a masking of glycolipidic group A receptors by glycoproteins of the erythrocyte membrane. Effects of enzymatic degradation (neuraminidase, trpysin, pronase) combined with incubation in NaF-medium for the deprivation of ATP could be explained by a rearrangement of receptors resulting in altered agglutinability of erythrocytes.

ABO Blood-Group System↗
PubMed1977

[Alcian blue induced mixed cell agglutination--short communication].

Because of its specific affinity to negatively charged sites of the cell surface, alcian blue is suitable to effect mixed cell agglutination between human erythrocytes and peritoneal macrophages of guinea pigs. This effect could be inhibited by adding heparin molecules which were negatively charged as well.

Agglutination↗
PubMed1977

[The possibility of use of amidinated human erythrocytes as agglutinin adsorbents in hemagglutination tests].

This study is concerned with the agglutinability of amidinated human erythrocytes. Amidinated erythrocytes behave like an immuno-adsorbent. Following the adsorption of an agglutinin, amidinated erythrocytes agglutinate specifically with native red blood cells or with native eukaryotic cells, if the glycocalyx of these native cells is provided with the respective agglutinin receptor groupings.

Amidines↗
PubMed1977

[Hemagglutination with Gal-N-Ac receptors in the hepatocyte membrane].

By means of mixed agglutination of isolated rat hepatocytes with human group A or rat erythrocytes, both of them were previously trypsinized and sialolyzed, respectively, a hepatocytic N-acetylgalactosamine-receptor was demonstrated. Gal-N-ac specifically inhibits this agglutination. Following oxidation with periodic acid red blood cells no more agglutinate with rat hepatocytes. This agglutination is not related to proteins adsorbed to hepatocytes. The agglutinability of erythrocytes and hepatocytes may bear some relevance to the elimination of old red blood cells.

Animals↗
PubMed1976

Spatial arrangement of some erythrocyte membrane receptor sites.

Alcian Blue proved to be a hemagglutinin specific for negatively charged receptors. Either sialylization or tryptic degradation of glycoproteins of human erythrocytes greatly diminished the agglutinability by Alcian Blue. Studies with group A antiserum, anti-AHP and the lectin of Lens culinaris demonstrated the masking efficiency of erythrocyte major glycoproteins. Previous proteolytic digestion enhanced the agglutinability of human red blood cells due to uncovering of what is considered glycolipidic group A receptors. The findings provide indirect evidence for the spatial arrangement of erythrocyte receptor sites.

Agglutinins↗
PubMed1976

[Intravital survival and deformability of weakly amidinated rat erythrocytes].

Rat erythrocytes previously labelled with 51Cr were treated with 0.1 mM and 0.5 mM dimethyladipic imidate (ADE) pH 9.5, respectively, or with borate buffer pH 9.5 for 15 minutes each. After reinjection into rats of amidinated or nonamidinated erythrocytes their elimination form the streaming blood was followed for 50 days (0.1 mM ADE) or 38 days (0.5 mM ADE). During the 1st day about 10% of amidinated erythrocytes were sequestered. There was no increased initial elimination rate of borate incubated red blood cells detectable. During the following period the elimination rate of erythrocytes amidinated with 0.5 mM ADE was slightly greater than in the case of erythrocytes treated with 0.1 mM ADE. The mean life span of 0.5 mM ADE-erythrocytes was shorter compared with the controls and with 0.1 mM ADE-erythrocytes. Red blood cells previously treated with 0.5 mM ADE are significantly less deformable. Presumably, the stiffness of amidinated erythrocytes causes their increased elimination rate.

Adipates↗
PubMed1976

[Mechanical resistance of amidinated human erythrocytes].

The amidination reactions by means of dimethyl adipimidate (0.25-10.0 mM) or dimethyldodecane-imidate (0.1-1.0 mM) cause an alteration of the mechanical resistance of red blood cells. Low amidination results in peripheral cross-links of erythrocytes whose mechanical resistance increase relative to borate buffer treated cells. Increasing cross-linking reduces the mechanical resistance of erythrocytes, which finally appears to have become restored. The final state, however, is characterized by an almost complete cross-linking of the cell, which than no longer behaves like an osmometer.

Amidines↗