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At least 19 recordsLinked to original sources
PubMed1977

Investigations on trace elements in normal and senile cataractous lenses. Activation analysis of copper, zinc, manganese, cobalt, rubidium, scandium, and nickel.

A total of 125 human lenses (97 senile cataractous and 28 clear) were analyzed by means of neutron activation analysis for trace element concentrations of copper, zinc, manganese, cobalt, rubidium, scandium, and nickel. Tt was found that the rubidium concentration remarkably decreased and the copper concentration moderately increased with the progression of cataract. The concentrations of manganese, zinc, and cobalt showed some fluctuations without a definite increase or decrease, and the scandium and nickel content was found to be very low.

Age Factors↗
PubMed1984

Studies of the antibacterial effect of the scandium complex of enterochelin.

The scandium complex of enterochelin is known to be assimilated and degraded by enterobacterial pathogens, liberating intracellular scandium. Macromolecular synthesis was inhibited in the order RNA, protein, DNA and phospholipid. Some component of heat-inactivated serum acts in concert with the complex inducing RNA degradation and killing. Both processes are inhibited by dinitrophenol. These biochemical changes resemble those found during complement mediated killing. An examination of the effect on synchronously growing cells suggests that the complex may exert its primary effect during the initiation of chromosome replication.

Anti-Bacterial Agents↗
PubMed1983

Antibacterial effect of the scandium complex of enterochelin. Studies of the mechanism of action.

There is good evidence to show that ferric enterochelin is an essential growth factor for a number of Gram-negative pathogenic bacteria exposed to the host iron binding proteins, transferrin and lactoferrin. Tests of nineteen complexes of enterochelin as potential antibacterial agents showed that only those containing either indium (In3+) or scandium (Sc3+) inhibited bacterial growth. In this study, further evidence is presented which demonstrates a competition between the Sc3+ and Fe3+ complexes. The uptake of both complexes is energy dependent and is also repressed in iron-replete cells. The Sc3+ complex accumulates within the cells at 20% of the rate of the Fe3+ complex. The main components of the ferric enterochelin transport system are required for the transport of the Sc3+ complex although some Sc3+ appears to enter the cell by another route. The accumulation, within the cell, of 14C-labelled enterochelin complexes depends on the growth medium. The relationship of the size of the metal ion to the biological activity of the complex is discussed and possible mechanisms of action of the Sc3+ complex are considered.

Anti-Bacterial Agents↗
PubMed1975

Trace element concentration in human brain. Activation analysis of cobalt, iron, rubidium, selenium, zinc, chromium, silver, cesium, antimony and scandium.

Up to 60 tissue samples were dissected from 13 human brains in defined regions and were analysed by means of neutron activation analysis for trace element concentration of cobalt, iron, rubidium, selesium, zinc, chromium, silver, cesium, antimony and scandium. It was shown that the variation in concentration of the non-essential elements in the different brain regions was greater than the corresponding variations in concentration of the essential elements. The mean values of Fe and Rb concentrations were higher in the basal ganglia than in the cortex areas. With increasing age the Fe concentration in the human brain was found to increase and that of Rb to decrease. Comparison of the trace element concentration in corresponding areas of the right and left hemispheres showed highly significant positive correlations for the essential elements. The concentration of each of the essential elements Fe, Rb and Zn was also found to differ significantly between defined functional regions. The characteristic distribution of essential trace elements in different areas is discussed in the light of known metabolic functions of these elements.

Adult↗
PubMed1982

Antibacterial effect of the scandium and indium complexes of enterochelin on Escherichia coli.

Enterochelin, the iron chelator produced by a number of pathogenic enterobacteria, appears to be an essential metabolite for multiplication within the host, where it transports iron from the host iron-binding proteins to the bacteria. Previous work showed that complexes of enterochelin containing either scandium (Sc3+) or indium (In3+) exerted a bacteriostatic effect on Klebsiella pneumoniae in serum, whilst the Sc3+ complex exerted a significant therapeutic effect on mice infected with K. pneumoniae. These observations have now been extended to a number of pathogenic serotypes of Escherichia coli including those carrying either the K1 antigen or the ColV plasmid. The Sc3+ and In3+ complexes each exert a bacteriostatic effect on these organisms growing in either whole serum or media containing an iron-binding protein. Evidence is presented that the Sc3+ complex may act as a competitive inhibitor of the Fe3+ complex. In contrast to their effects on K. pneumoniae, sideramines other than enterochelin fail to reverse the bacteriostatic effect of the Sc3+ complex of enterochelin in E. coli, suggesting that the complex produces a more profound derangement of metabolism in this organism. The Sc3+ complex exerts a significant therapeutic effect on E. coli infections in mice although the In3+ complex is less active.

Animals↗
PubMed1991

Complexes of mycobactin from Mycobacterium smegmatis with scandium, yttrium and lanthanum.

The interaction of cations of group IIIb elements (Sc, Y, La) with mycobactin S in ethanol leads to the formation of 1:1 complexes which closely resemble the known aluminium compound with respect to ultraviolet absorption and fluorescence emission spectra. Determination of molar stoichiometry by spectrophotometry shows that this method can be conveniently applied to the estimation of purity in mycobactin samples. Hydrolytic dissociation measurements based on aqueous extraction of the labelled complexes in heterogeneous phase indicate a pronounced gradation in cation-binding stability, which increases from La (rapid and complete dissociation) to sc (approximately 24% dissociation under similar conditions). The observed properties of the complexes are rationalized by semi-empirical model calculations, which suggest that ionic radius effects resulting from interaction of the IIIb cations with mycobactin S would not favour octahedral coordination of these elements as in the stable Fe(III) complex.

Kinetics↗