The lead content of hair in workers occupationally exposed was correlated with the blood lead concentration. Determinations of lead in blood and hair were performed by electrothermal atomic absorption spectrophotometry in two exposed groups and a control group. A significant correlation was observed between the blood lead and hair lead concentrations, and a regression analysis showed an exponential accumulation of the lead content in hair, simultaneously with the increase of the values in blood. The colour of the hair and the age of the subject did not influence the lead accumulation in hair in the occupationally exposed subjects. The assessment of lead in hair is considered a useful screening test in estimating occupational exposure.During recent years a series of studies have pointed to the use of the content of lead in hair as an index of occupational exposure indicator.'-5 Modem analytical techniques now allow the metal content to be measured in sequential segments of hair.26The present study aimed to follow up the examination of lead in a single hair in workers occupationally exposed and to correlate this with the blood lead concentration. Materials and methodsTwo groups of male workers with differing occupational experience were studied: group 1 comprised 31 subjects exposed to high concentrations of lead in air and group 2, 33 subjects with low exposure. The ages and years of exposure of these two groups are presented in tables 1 and 2. Blood samples were collected on heparin from each exposed person together with five hairs, including the root. Before the analysis the hair was washed in acetone, ethylic ether, and 1*5% solution of sodium lauryl sulphate in order to degrease it and remove exogenous lead, particles7; segments of exactly 1 cm in length, measured from the root, were then taken. To verify the cleanliness of the surface, three hairs (before washing, after a single washing,

Pretreatments of B. subtilis and S. aureus cells with lower concentrations of fixative agents, led to modifications in bacteriolytic effect exerted by polyarginine and protamine: Glutaraldehyde blocked polycation bacteriolysis while formaldehyde and osmium tetroxide (OSO4) having no influence on polyarginine action, increased constantly the cell sensitivity to protamine in lower doses otherwise nonlytic; the sensitizing action also resulted in the extension of protamine bacteriolytic pattern including several staphylococcal strains; higher bacteriolytic doses of protamine were contrastively unable to lyse OSO4 prefixed cells and gave an inconstant lytic value with formaldehyde treated bacteria. With higher concentrations, OSO4 preserved intactly its sensitizing action while formaldehyde displayed a decrease in its ability to sensitize B. subtilis cells to the lytic effect of protamine. Scaning electron microscopy of polycation treated cells showed prelytic lesions as surface granulations, shape and size modifications and cell splits. The interpretation of the results in terms of intra-and intermolecular adducts accompanied by con­ formational changes in surface macromolecules is discussed. It is concluded that the results match the model of polycation bacteriolysis by wall multizonal picnosis leading to surface splits and thereby triggering cell-lysis.

We compared the immunohistochemical expression of putrescine (PUT), spermine (SPM), ornithine decarboxylase (ODC), and diamine oxidase (DAO) in bioptic samples of canine colonic mucosa with chronic inflammation (i.e., granulomatous colitis and lymphoplasmacytic colitis) or neoplasia. Single and total polyamines levels were significantly higher in neoplastic tissue than in normal samples. Samples with different degrees of inflammation showed a general decrease expression of ODC if compared to controls; SPM was practically not expressed in control samples and very low in samples with chronic-granulomatous inflammation. In carcinomatous samples, the ODC activity was higher with respect to controls and samples with inflammation. This is the first description of polyamines expression in dog colonic mucosa in normal and in different pathological conditions, suggesting that the balance between polyamine degradation and biosynthesis is evidently disengaged during neoplasia.

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