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Biomedical subjects

P C Simons

Publications and source records attributed to P C Simons.

23 records · Page 2Linked to original sources
PubMed1980

Bilirubin binding to human liver ligandin (glutathione S-transferase).

The number of binding sites and the dissociation constants were determined for the binding of bilirubin to human liver ligandin and to human serum albumin. Albumin has a primary bilirubin binding site (KD = 0.03 microM), measured by the peroxidase procedure, and two apparently equivalent secondary binding sites (KD = 2 microM), determined by fluorescence quenching experiments. By contrast, ligandin does not have a corresponding high affinity site. The absence of this high affinity site was shown both by the peroxidase procedure and by direct competition between albumin and ligandin for bilirubin. Bilirubin binding to ligandin, measured by fluorescence quenching, is complex. At both pH 6.5 and 7.4, two interacting sites were observed with a Hill coefficient of 1.5, K' approximately 5 microM. Bilirubin binding to ligandin is not independent of glutathione S-transferase activity. Depending upon pH and upon the order with which the reactants are added, bilirubin can markedly alter the transferase activity. The results are interpreted in terms of kinetically stable conformational isomers of ligandin induced by bilirubin or by glutathione.

Bilirubin↗
PubMed1978

Twisted legs in broilers.

The effect of various factors on the incidence of leg abnormalities, with particular reference to twisted leg, in broilers was studied. The incidence of twisted legs was influenced by strain and for males was twice that for females. There was also a higher incidence in cages than on litter with the type of cage floor having an effect: broilers reared on floors of metal wire and perforated sheets had more leg problems than those reared on plastic mats and plastic-covered wire. Although vitamin and mineral supplementation had no effect on caged broilers, a restriction of metabolisable energy (ME) intake during the first 14 d after hatching halved the frequency of leg abnormalities compared with those fed ad libitum. Studies of cage size and location of water suggested that a lack of exercise increases the incidence of leg abnormalities.

Animals↗