No abstract

Ihstrcrcr:The in vitro antiproliferative activity and in i t v o phototoxicity of some methyl derivatives of ~-methoxypsoraleit ,~n d 5-methoxyangelicin, i.e. 4,4'-dimethyl-5-methoxyangelicin (compound I), 3,4'-dimethyl-5-methoxyangelicin (compound 11). 4,4'-dimethyl-5-methoxypsoralen (compound 111); and 3.4'-dirnethyl-S-methoxypsoralen (compound lV), have been investigated. The effects of the compounds were evaluated in vi/ru on HL60 and A43 I cells, using 5-niethoxypsoralen ; I S the reference compound. In both cell lines compound 1, 11 and 111 showed better antiproliferative activity than coinpound 1V and 5-methoxypsordlen. Scanning electron microscopy revealed [hat all the compounds induced the formation of blebs and blisters on a A431 cell surface. Significant variations in the nuclear area strictly related to the toxicity of the compounds have been shown in both cell lines. Skin Irritancy in viiw was evaluated by mean of histopathological responses on guinea-pig skin. For each compound a damage index was determined by morphometrical analysis of empty spaces in the epidermis. Histopathology revealed skin phototoxicity of compounds which lacked erythemogenic activity by visual ,coring. By coupling cytotoxicity data in virro to skin sensitization ones in viva. compound I proved a promising candidate for use in clinical trials since due to a high inhibitory effect on the growth of human cell lines coupled to low skin phototoxicity.

We analysed the molecular properties of the immunodominant protein of different orf virus strains isolated in Italy. The F1L encoding genes and the deduced amino acid sequences of all strains were determined and compared, and they showed several mutations. Structural analysis was carried out in order to assess the influence of amino acid variations on protein structure demonstrating a conservation of the secondary structure. Western blot analysis and immunogold electron microscopy showed that all orf virus strains were antigenically identical. The results of our study confirmed the immunogenicity of the F1L protein; furthermore, our data suggest a possible involvement of the protein in the virus cycle.

No abstract

In order to define safety profiles and proper handling procedures for new industrial products, it is essential to determine their potential for ocular irritation. The Draize test is normally employed but it involves using rabbits. There is today a great need for all researchers to limit the use of animals for laboratory experiments and to encourage the development and adoption of alternative in vitro methods to evaluate the potential toxicity of new products. This study proposes a three-dimensional model of bovine corneal stroma and epithelium that is not only easy to reproduce but may also be used in the toxicological field as an alternative to animal experimentation. The data presented here show that this model allows the growth of epithelium similar in features to in vivo epithelium. Basal cells are cube-shaped, whereas superficial areas are horizontally longer; desmosomes and 64 kDa keratin, as a marker for differentiation of corneal epithelial cells, are both expressed; the basal lamina is synthesised also. The 3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide (MTT) assay was carried out on the model to evaluate the toxicity of some surfactants: benzalkonium chloride, Triton X-100, sodium dodecylsulphate and Tween 20. Since the in vitro data fit very well the results of the Draize test in vivo as reported in the literature, the three-dimensional culture may be used to predict the potential cytotoxicity of surfactants.

No abstract

All of the data supported a neoplastic process producing perivascular wall tumours. Immunoreactivity to smooth muscle actin and the ultrastructural features were indicative of a pericyte origin (haemangiopericytoma). This is the first report dealing with Hikui disease that has achieved a conclusive diagnosis. The neoplastic nature of this condition suggests the potential usefulness of a surgical approach in the clinical management of less severe cases.

The effect of 4-hydroxymethyl-6,7,8,9-tetrahydro-2H-benzofuro-[3,2-g]-1-benzo piran-2-one (compound 1) and 4-hydroxymethyl-2H-benzofuro-[3,2g]-1-benzopiran-2-one (compound 2), two new benzopsoralen derivatives, was tested on HL60 and HeLa cell lines in the dark and by UVA irradiation; 8-methoxypsoralen was used as a reference compound. The action of the compounds was evaluated by means of the neutral red uptake assay, by means of ultrastructure, morphometry and interaction with human erythrocytes membrane. In both HL60 and HeLa cell lines benzopsoralen derivatives showed more antiproliferative activity after UVA irradiation, however less than 8-methoxypsoralen. Compound 1 was more effective than compound 2 both in the dark and after UVA irradiation. The ultrastructure showed a morphological rank damage caused by these compounds: compound 2 induced slight modifications in the cytoplasm organization, compound 1 induced some vacuolizations and 8-methoxypsoralen generated plenty of vacuoles and an empty space around the nucleus. Morphometrical data in HL60 cells turned out to be in accordance with the different action mechanisms existing between 8-methoxypsoralen and the two benzopsoralen derivatives; in HeLa cells we noted an increase in the nuclear area induced by all the three compounds. Only compound 1 caused the formation of echinocytes both in the dark and after UVA irradiation, suggesting the involvement of a mechanism not strictly related to DNA interaction and singlet oxygen production.