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Biomedical subjects

C Moreno

Publications and source records attributed to C Moreno.

At least 217 records · Page 12Linked to original sources
PubMed1977

Mechanism of the anti-tumour effect of glucans and fructosans: a comparison with C. parvum.

The anti-tumour activity induced by glucans (lentinan, yeast cell walls, pseudonigeran, dextran, DEAE-dextran and dextran sulphate) and fructosans (levan and carboxymethyl-levan) was compared with the activity of C. parvum. The following effects on tumour systems in CBA mice were assayed: (a) adjuvant activity on the immune response against tumour-specific transplantation antigens (TSTA) with a methylcholanthrene-induced fibrosarcoma; (b) cytostatic activity of peritoneal macrophages against radiation-induced leukaemia cells; and (c) inhibition of tumour nodule formation in the lungs following i.v. injection of fibrosarcoma cells. All the polysaccharides induced cytostatic macrophages, but the dextrans and levans did so only after i.p. and not i.v. injection. Only lentinan, yeast cell walls and pseudonigeran were active in the lung-nodule inhibition test; and only lentinan and dextran sulphate showed slight adjuvant activity for TSTA. It is concluded that the anti-tumour activity induced by these polysaccharides is predominantly non-specific macrophage-mediated and much weaker than that found with C. parvum.

Animals↗
PubMed1976

Blockade of specific antibody-forming cells in vivo by dextrans and levans.

Fractions of dextrian (DE) B512, DE B1355 and levan (LE) have been shown to induce a specific blockade of antibody-forming cells (AFC) when injected into previously immunized mice. Whereas specific blockade with DE B512 (450 000 daltons) was easily induced by as little as 10 mug, blockade to LE and DE B1355 was more resistant and required 1 and 10 mg, respectively. AFC blockade and tolerance are dissociable phenomena, as the former effect could be achieved with nontolerogenic low mol. wt DE B512 (10 000 daltons). Conversely, perennial rye grass fructosan (7600 daltons), which is tolerogenic for LE, did not induce a blockade. Furthermore, blockade of anti-DE response specific for alpha (1 leads to 3)-linked glucosyl determinants was achieved in BALB/c mice, whereas attempts to induce stable tolerance have been unsuccessful.

Animals↗
PubMed1971

Immunochemical studies on blood groups. LI. A comparative study of the reaction of A 1 and A 2 blood group glycoproteins with human anti-A.

The immunochemical properties of purified A(1) and A(2) glycoproteins have been compared to ascertain whether their antigenic determinants differ. Quantitative precipitin and complement-fixation studies using several anti-A sera as well as purified gammaG anti-A antibodies clearly showed a specificity difference. This was also supported by absorption studies: A(2) substance specifically removed antibodies reacting with A(2) substance leaving anti-A(1) activity. A(1) substance was more effective than A(2) substance in dissolving an A(1) anti-A(1)-specific precipitate. Purified gammaM anti-A hemolyzed A(1) cells more readily than A(2) cells. Inhibition studies using mono- and difucosyl type 2 A-active oligosaccharides showed that type 2 difucosyl receptors are present in A(2) substance. The structural basis for the specificity difference between A(1) and A(2) would appear to be that A(2) substances lack type 1 A determinants; this would account for the observed higher H and Le(b) activity in A(2) substances.

ABO Blood-Group System↗
PubMed1969

Studies on human antibodies. 8. Properties and association constants of human antibodies to blood group A substance purified with insoluble specific adsorbents and fractionally fluted with mono- and oligosaccharide.

Human antibodies to blood group A substance were purified by absorption on columns of insoluble polyleucyl hog blood group A + H substance and eluted first with N-acetylgalactosamine and then with an A active reduced pentasaccharide AR(L)0.52. The gammaM and gammaG antibodies in these eluates were separated by density gradient centrifugation. The antibodies were studied for their relative capacities to be inhibited by various blood group A active oligosaccharides. Antibodies eluted by the N-acetylgalactosamine could be inhibited by N-acetylgalactosamine, as well as by lower concentrations of A active tri- and pentasaccharides, while those eluted by the pentasaccharide AR(L)0.52 could only be inhibited by the two oligosaccharides, but not by N-acetylgalactosamine, indicating that the N-acetylgalactosamine eluate had more antibodies with smaller size combining sites than the AR(L)0.52 eluate. Measurements by equilibrium dialysis gave values ranging from 2 x 10(3) to 1 x 10(5)M(-1) and the values obtained with the AR(L)0.52 eluate were somewhat higher than those with the GalNAc eluate. Only one of three anti-A sera had gammaM anti-A in the AR(L)0.52 eluate, while all three had gammaM in the N-acetylgalactosamine eluate. Data on the precipitating, hemagglutinating, complement fixing, hemolytic properties of the eluted antibodies, and of their content of kappa and lambda light chains are given.

Adsorption↗