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Biomedical subjects

G Geyer

Publications and source records attributed to G Geyer.

At least 145 records · Page 8Linked to original sources
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

[Nasal application of a synthetic alpha1-18 corticotropin: an effective form of ACTH treatment (author's transl)].

The absorption of a synthetic ACTH-peptide (alpha1-18 corticotropin, Ba 41.795) via the nasal mucosa was investigated in twelve probands. After application of 1 mg into each nostril a rapid increase of the plasma cortisol was observed which returned to the initial value only after 7 hours. In two patients with rheumatoid arthritis and two patients with bronchial asthma who had been treated with regular steroid injections an attempt was made to replace the injections by nasal application. The same therapeutic effects could be obtained, but larger doses were required than when using injection therapy.

Administration, Intranasal↗
PubMed1976

Inverse localization of Ca2+ and La3+ high affinity binding sites of the red cell membrane.

Glutaraldehyde fixation in the presence of both 90 mM La3+ resulted in opaque deposits were also seen in specimens fixed in a glutaraldehyde-CaCl2 medium devoid of La3+. In that case only small amounts of a moderately opaque substance had accumulated or remained at the external surface of the erythrocyte membrane. Specimens previously fixed with Ca2+, La3+ supplemented glutaraldehyde lost their internal deposits completely during postifixation with OsO4. The findings provide evidence of Ca2+ high affinity binding sites at the internal surface of the erythrocyte membrane presumably identical with the filamentous matrix. Glycocalyx constituents are considered external Ca2+ low affinity binding sites, however, capable of accumulating high amounts of La3+ during glutaraldehyde fixation.

Binding Sites↗
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

Calcium binding to the erythrocyte membrane.

Calcium binding sites of human red blood cells were localized by means of a method according to OSCHMAN and WALL (1972). The procedure resulted in multiple opaque deposits at the inner surface of the erythrocyte membrane.

Binding Sites↗
PubMed1976

l-Alpha-acetylmethadol (LAAM): prognostic considerations.

The authors studied the responses of 28 adult male volunteers who were openly changed from methadone to l-alpha-acetylmethadol (LAAM) maintenance. They found that patients who had been receiving middle-range doses (50-70 mg) of methadone required a significantly lower mean increase in LAAM than patients who had been receiving either high or low methadone doses and that the patients who accepted LAAM differed significantly from those who did not in MMPI 2-point-code ratings and mean social adjustment scale scores. These findings may provide prognostic indicators for response to LAAM, a possible alternative to methadone.

Heroin Dependence↗
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↗
PubMed1976

[The correlation of human erythrocyte shape with dark-field light scattering intensity].

This study was concerned with the quantitative evaluation of dark field light scattering by sedimented erythrocytes of banked human blood samples. Due to considerable variability of both appearance and amount of scattered light the discocyte group had to be subdivided into discocyte I and discocyte II. The mean intensity of scattered light increased about three fold from discocyte II to echinocytes I, II, III, sphaeroechinocyte, and sphaerocyte. On the other hand the average light scattering intensity of discocytes I exceeded that of discocytes II about 2.5 times, with individual data varying over a wide range. There was a rapid disappearing of discocytes I correlated with time of storage. Therefore it is concluded that discocytes I represent the initial stage of erythrocytes transforming under banking conditions.

Blood Preservation↗
PubMed1976

["Sugar-agglutinability"].

Haemagglutination induced by saccharose is shown to go parallel with a binding of autologous isohaemagglutinin to the surface of erythrocytes. Under suitable conditions, i.e. in the presence of anorganic ions and health, haemagglutinin may be largely separated from the cell surface and the saccharose agglutination may be inhibited. Haemagglutination induced by saccharose will re-appear after agglutinins being re-adsorbed at low incubation temperatures and prolonged incubation time in non-ional as well as ional media. Therefore it is assumed that in the inert non-ional atmosphere the autologous haemagglutinin will produce a phenomenon of agglutination in non-homologous erythrocytes similar to that in homologous cells.

Erythrocytes↗
PubMed1975

[Studies on the osmotic resistance and the viability of amidinated erythrocytes].

The present studies are concerned with properties of amidinated erythrocytes. The reactions of dimethyladipimidate with proteins in solution and red blood cells, respectively, result in an intermolecular cross-linking. Following an amidination of human serum albumin or human gamma-globulin cross-linked products of increased molecular weight have been demonstrated by polyacrylamide gel and immune electrophoresis. Human erythrocytes previously amidinated intensely, exhibit a restricted motility of membrane particles and cross-linked hemoglobin. Intensely amidinated erythrocytes are resistant against distilled water, and they do no longer agglutinate. The findings presumably indicate an increased permeability of the amidinated red cell membrane. The glycolytic activity was found to be normal in moderately amidinated erythrocytes. In comparison with normal red blood cells, previously moderately amidinated erythrocytes of the rat become sequestered more quickly after re-injection into the vascular system.

Amidines↗
PubMed1975

Porosity and surface area of anionic resins: limitations in the employment of model substrates for the colloidal iron reaction.

Quantitative evaluations of the uptake of an acid ferric hydroxide sol revealed the iron binding of model substrates unrelated to their ion binding capacity. Electron microscopy showed iron particles bound exclusively or mainly to the surfaces of model substrates. Morphometric estimations resulted in a good agreement of the surface/volume ratio with the amount of bound iron. The results are discussed with regard to the steric hindrance of the colloidal iron reaction resulting in a nonstoichiometric interaction.

Anion Exchange Resins↗