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Biomedical subjects

G F Springer

Publications and source records attributed to G F Springer.

At least 127 records · Page 7Linked to original sources
PubMed1970

Specific inhibition of endotoxin coating of red cells by a human erythrocyte membrane component.

We have isolated from human erythrocyte ghosts a fraction which prevents the attachment of unheated as well as heated lipopolysaccharides of gram-negative bacteria to red cells. This material has no significant inhibitory effect either toward the Vi antigen of gram-negative bacteria or towards the group and common antigens of the gram-positive bacteria investigated. We, therefore, named this fraction "lipopolysaccharide receptor." The receptor interacts with lipopolysaccharides and not with erythrocytes, it forms complexes with and blocks those groupings of lipopolysaccharides which attach to red cells. The effect of the receptor is physical and not enzymatic. The interaction of the receptor with the lipopolysaccharides is reversible, and the receptor removes lipopolysaccharides fixed to red cells. An equilibrium of lipopolysaccharide distribution between cells and receptor is established when receptor-lipopolysaccharide complexes are incubated with red cells. The receptor is labile toward heat and deviation of the hydrogen ion concentration from neutrality; aldehydes destroy its inhibitory activity.

Journal Article↗
PubMed1969

The relationship of the influenza virus inhibitory activity of glycoproteins to their molecular size and sialic acid content.

Twenty-four different glycoproteins were investigated for their ability to inhibit hemagglutination by the A/PRS and the B/Md influenza virus strains. A relationship between activity, the molecular size, and sialic acid content was found. This relationship was readily shown for the A/PR8 virus if the properties of the glycoproteins were compared with one another on a per cent basis. A proportion of approximately 1:1:1 for activity (weight basis) to moles sialic acid content to molecular weight existed for each inhibitory glycoprotein with more than 3 per cent sialic acid, on comparison with any other active glycoprotein.A 1:3 correspondence between viral subunit and sialic acid residues of the inhibitor ovine submaxillary mucin was found experimentally and confirmed by calculation on a molecular model. The most potent inhibitors, were the antigens of the human blood-group MN system and the Tamm-Horsfall urinary glycoprotein.

Glycoproteins↗
PubMed1969

Blood group isoantibody stimulation in man by feeding blood group-active bacteria.

It was investigated whether or not the human blood group isoantibodies A and B could be induced by immunogenic stimuli via natural routes with a kind of antigenic substance to which all humans are commonly exposed, or if the appearance of these antibodies is independent of antigenic stimuli as has long been believed. Escherichia coli O(86), which possess high human blood group B and faint A activity in vitro, were fed to healthy humans and those with intestinal disorders. 80% of the sick individuals of blood group O and A responded with a significant rise of anti-B antibodies which was frequently de novo in infants; significant increase of anti-A isoantibodies among blood group O individuals was less frequent. Over one-third of the healthy individuals also had a significant isoantibody increase. Intestinal lesions favor isoantibody stimulation by intestinal bacteria; this view was supported by the study of control infants. Persons of blood group A responded more frequently with anti-B and anti-E. coli O(86) antibody production than those of blood group O. Isoantibody increase was accompanied with antibody rise against E. coli O(86). Inhalation of E. coli O(86) or blood group AH(O)-specific hog mucin also evoked isoantibodies. The induced isoantibodies were specifically inhibited by small amounts of human blood group substances. E. coli O(86)-induced anti-blood group antibodies in germ-free chickens and preexisting blood group antibodies in ordinary chickens were neutralized by intravenous injection of E. coli O(86) lipopolysaccharide. This study demonstrates that human isoantibodies A and B are readily elicited via physiological routes, by blood group-active E. coli, provided the genetically determined apparatus of the host is responsive. Antibodies against a person's own blood group were not formed. Interpretation of these results permits some careful generalizations as to the origin of so-called natural antibodies.

ABO Blood-Group System↗
PubMed1968

Conformation of blood-group and virus receptor glycoproteins from red cells and secretions.

Optical rotatory dispersion of human blood-group and virus receptor glycoproteins from erythrocytes and secretions was studied in the far-ultraviolet. Erythrocyte membrane blood-group glycoproteins, with potent virus receptor activities, contained significant alpha-helical and extended beta conformations, whereas the glycoproteins of secretions were largely disordered. These conclusions were supported by determination of the Moffitt constants (b(0)) and by measurements of circular dichroism.

Antiviral Agents↗
PubMed1959

Origin of anti-human blood group B agglutinins in white Leghorn chicks.

While anti-human blood group B agglutinins are present in the majority of ordinary White Leghorn chicks by the age of 30 days, none could be demonstrated in germfree chicks up to the age of 60 days. Anti-B agglutinins in trace amounts were first found in germfree chicks 66 days old and increased to an average titer of about 1:2 by 91 days of age. This titer amounts to about 10 per cent of that found in ordinary chicks. The appearance of antibody in low titer is attributed to trace amounts of non-living antigenic contaminants penetrating the germfree barrier. The necessity of appropriate absorption in order to obtain well defined specificities was pointed out. Several means commonly used to differentiate between normal and immune antibodies were employed in this investigation. None showed a difference between anti-B agglutinins from ordinary chicks and from germfree chicks intentionally immunized with blood group B active E. coli O(86) or with B active preparations from human meconium. The implications of these findings on the origin of natural agglutinins are discussed. It is concluded, that measurable anti-human blood group B agglutinins in White Leghorn chicks are acquired early in life and are not inherited. The possibilities as well as limitations of present day germfree technique for this kind of immunological research have been considered.

Agglutinins↗
PubMedDate not supplied

Relation of human blood-groups MN to cancer cell surface antigens and to receptors for oncogenic viruses.

It has been shown by us that the human blood-group MN antigenic determinants are not the products of allelomorphic genes as believed so far, but that N is the precursor substance of M and that the allelomorph to the M gene is amorph. The determinant structure of the N antigen is branched and possesses as non-reducing termini beta-d-galactopyranosyl (Gal) and alpha-N-acetylneuraminic acid (NANA) linked to beta-Gal. The M substance differs from N only in that alpha-NANA covers the terminal beta-Gal of the N determinant. Vicia graminea anti-N reacts with terminal beta-Gal of the N antigen as well as its precursor. A human blood-group N-like antigen in the cell surface of the TA3 mammary adenocarcinoma (ascites form) has been found by us. The TA3 cancer occurs as the non-strain specific Ha subline and as the strain-specific St subline. This is the first description of an N-like antigen in a non-primate as well as a tumor. This antigen reacts with Vicia anti-N. In serological specificity the Vicia agglutinin is closely related to the Thomsen-Friedenreich anti-T agglutinin present in most human and animal sera. These sera plus complement kill ordinary TA3-St cells and sialidase-treated Ha cells to less than 95 percent. Untreated TA3-Ha cells are fully resistant even though they absorb cytotoxin. Beta-galactosidase treatment of either Ha or St cells abolishes the killing activity of the sera. The cancer cells absorb anti-T but they lose this capability after exposure to beta-galactosidase. An immunological cross-relationship between the human blood-group MN antigens and the receptor for an oncogenic virus, the avian subgroup B leukosis sarcoma virus has been observed.

Adenocarcinoma↗