Giovanni Porcelli

Gel filtration of ABH blood group substances. I. Fractionation of ABH substances of human saliva.

Human saliva from secretors of groups A, B, O and AB was gel filtered on Sephadex G-200 and G-100 columns, and on thin layers and the eluates were tested for A, B and H antigens by the haemagglutination inhibition method. A main excluded fraction (fraction 1) was detected in all the samples examined. A part of this fraction was also excluded from Sepharose 4B. The molecular weight of this fractions can be assumed to be between 2·105 and 5·106. In some samples of saliva, one or two group-specific subfractions were identified (fractions 2 and 3). Fraction 2 is excluded from Sephadex G-50 and probably has a molecular weight between 10 000 and 13 000. Fraction 3 is dialysable and has a lower molecular weight, probably no greater than 1500–2000. Fraction 1 is water-soluble and can be precipitated in alcohol, while fractions 2 and 3 are both water- and alcohol-soluble.

Effects of environmental lead levels on the urinary kallikrein excretion of exposed workers.

Ten men, working in a factory making car batteries, were hospitalized in order to establish the diagnosis of lead intoxication. The urinary kallikrein activity, determined in their 24-hr urines, was found to be lower than that of a control group. Kallikrein activity was then determined in morning urines of another group of 25 lead exposed men working in the same factory. The urines of this group were collected before and after some environmental improvements which reduced lead concentration in the factory ambient air. The urinary kallikrein excretion of exposed workers was very low before environmental improvements. After the lead reduction in the environmental air, the urinary kallikrein excretion of the same workers was significantly increased; nevertheless, it remained still lower than the control group.

Investigations on ficin : III. Purification of ficin by gel filtration and the characterization of other protein fractions of ficuslatex

Purified ficin obtained by repeated precipitation with ammonium sulphate was passed through a column packed with Sephadex G-100. Ficin and other protein fractions were obtained. The first two fractions by heat effect (37°), give rise to proteolytic active fraction.