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Biomedical subjects

A Paul

Publications and source records attributed to A Paul.

At least 235 records · Page 13Linked to original sources
PubMed1982

Incompatible blood-group A determinants in tumoral mucins. Isolation of oligosaccharides having a 2-acetamido-2-deoxy-alpha-D-galactopyranosyl group at the non-reducing end.

Two glycopeptide fractions were obtained from pseudomyxomatous mucins secreted by an ovarian cystadenocarcinoma from a female having blood-group B, and by an appendix tumor from a male having blood-group O. The carbohydrate and amino acid content of these fractions suggests the presence of numerous carbohydrate side-chains linked through O-glycosyl bonds to a peptide core rich in threonine and proline. The two glycopeptide fractions exhibit compatible B- and H-blood-group activities. They are reactive towards Dolichos biflorus lectin and human anti-A agglutinins, and so exhibit an incompatible A activity. Alkali-borohydride degradation of Pronase-digested glycopeptides gave dialyzable oligosaccharides that were purified and shown to possess 2-acetamido-2-deoxygalactitol at the terminal reducing-end. 2-Acetamido-2-deoxyglucose, galactose, fucose, and neuraminic acid were absent, or present, in variable proportions. Four oligosaccharides containing 2-acetamido-2-deoxy-D-galactose residues were reactive towards Dolichos biflorus lectin and human anti-A agglutinins, indicating the presence, at the nonreducing end, of a 2-acetamido-2-deoxy-alpha-D-galactopyranosyl group, responsible for blood-group A activity.

ABO Blood-Group System↗
PubMed1982

[Alpha-N-Acetylgalactosaminyl transferase activity in mucous ovarian tumors obtained from blood group O2 patients (author's transl)].

We have demonstrated, by the transfer of (1-14C) GalN Ac from exogenous UDP[ (1-14C) GalN Ac into a glycopeptide H-acceptor, the presence of an alpha-N-acetylgalactosaminyltransferase in the wall and fluid of ovarian tumors. The transfer occurs in the absence of exogenous acceptor but to a greater degree in the tumor wall and fluid obtained from blood group O patients, thereby indicating the presence of preferential endogenous acceptor(s) in tumors of these subjects.

ABO Blood-Group System↗
PubMed1980

Role of bacterial interactions in the colonization of oral surfaces of Actinomyces viscosus.

The effects of several microbial residents of human oral cavities on the attachment of Actinomyces viscosus T14V to tooth surfaces were assessed by using the saliva-coated hydroxyapatite (sHA) in vitro system. Attachment to sHA by A. viscosus T14V was not inhibited in the presence of Streptococcus mutans GS5, either in the presence or absence of sucrose. Precoating sHA beads with S. mutans in the presence of sucrose also did not retard strain T14V attachment. However, the presence of Streptococcus sanguis M5 during strain T14V attachment markedly inhibited the interaction of A. viscosus T14V with sHA, whereas another S. sanguis strain, strain G9B, produced relatively weak inhibition. The inhibitory effect of S. sanguis M5 appeared to result from the direct interaction of this organism with A. viscosus T14V. Conversely, the presence of strain T14V markedly increased the attachment of S. sanguis M5 to sHA while partially inhibiting the attachment of S. sanguis G9B. Moreover, sHA beads precoated with A. viscosus T14V bound much higher levels of S. sanguis M5 relative to uncoated sHA, whereas S. sanguis G9B attachment was only weakly inhibited. It was also observed that sHA beads precoated with either S. sanguis M5 or G9B inhibited subsequent attachment by strain T14V. These results suggest the possibility that the attachment sites for both S. sanguis strains partially overlap those for A. viscosus T14V. Streptococcus mitis weakly inhibited attachment of strain T14V to sHA, and both Streptococcus salivarius and Lactobacillus casei had little effect on attachment. In addition, both a radioisotope attachment assay and fluorescent microscopy demonstrated no significant attachment of A. viscosus T14V to human epithelial cells.

Actinomyces↗
PubMed1978

Factors influencing lactation performance in rural Gambian mothers.

Breast-milk consumption has been measured in a rural African community in which breast-feeding on demand is universally practised until the baby is 18 mos old. The mother's long-term capacity for breast-milk production is determined by the end of the second month of lactation, yield being closely correlated with the infant's birth-weight. Other factors significantly influencing output were parity, month of lactation, baby's weight-for-age, season, and maternal diet. Daily milk consumption was limited primarily by the amount delivered per feed, not the frequency of feeding.

Body Weight↗