The possibility of using a recombinant fragment of the CagA (128 kDa protein) for the diagnosis of Helicobacter pylori infection was evaluated. Following cloning of the gene coding for the CagA, a recombinant fragment of it was expressed in Escherichia coli, purified and used in Western blot and an EIA to screen sera from 82 patients with gastroduodenal disease who underwent endoscopic examination. In Western blot, good correlation was found between the serological data obtained with the recombinant antigen and those obtained using non-purified extracts of Helicobacter pylori. The EIA using the antigen showed a sensitivity of 96.2% and a specificity of 96.6% compared with Western blot. These data indicate that the recombinant protein is a reliable antigen for detection of infections with Helicobacter pylori strains that are associated with disease. The EIA assay described may be used in follow-up of the progression of the illness and the results of therapy.

Antral biopsy culture supernatants from 14 subjects with chronic gastritis, known to have IgA antibodies to the 120 kilodalton protein, showed positive recognition of this antigen in western blots against a cytotoxin positive strain of Helicobacter pylori but gave negative reactions with two cytotoxin negative strains. Control immunoblots with culture supernatants from 13 non-responders to the protein were all negative. This indicates a direct association between expression of the 120 kilodalton protein in H pylon strains and cytotoxicity.

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We show that solid and liquid media, supplemented only with cyclodextrins and free of blood and its derivatives, support the growth of Helicobacter pyloyi. These media can be used for primary isolation of the bacteria from biopsy samples, routine laboratory growth, and large-scale industrial fermentation.

We have evaluated by means of immunocytochemistry the distribution of various cytoskeletal and contractile proteins (cytokeratins, vimentin, desmin and alpha-smooth muscle actin) in 23 salivary or lacrimal gland primary tumours (15 pleomorphic adenomas and 8 carcinomas in pleomorphic adenoma), one third of which contained areas of normal gland. Normal epithelial luminal cells were stained by cytokeratin antibodies with a general specificity, while myoepithelial cells were selectively stained by a monoclonal antibody (SK2-27) reacting in immunoblots with cytokeratin polypeptides 14, 16 and 17, according to the classification of Moll et al. (1982) and by an antibody directed against alpha-smooth muscle actin (Skalli et al. 1986). In pleomorphic adenomas, both epithelial and myoepithelial cells displayed typical topographic distributions; moreover, myoepithelial cells showed two distinct cytoskeletal phenotypes. These findings could account in part for the heterogeneity of aspects observed in this tumour. In carcinomas, malignant cells were always positive to cytokeratin antibodies with general specificity and myoepithelial cells were absent as judged by anticytokeratin SK2-27 and anti-alpha-smooth muscle actin immunostainings. However, interestingly, there was in all cases a strong positivity for alpha-smooth muscle actin in stromal cells, similarly to what has previously been described for mammary carcinoma (Skalli et al. 1986). Our findings may be useful for the interpretation of the histogenesis of salivary and lacrimal tumour and stromal cells.

No abstract

Polyclonal antibodies able to recognize protein-acetaldehyde conjugates were produced and characterized. The antibodies react with sodium cyanoborohydride-reduced Schiff's bases between acetaldehyde and a protein, independently of the nature of the macromolecule binding the acetaldehyde moiety. Only conjugates between acetaldehyde or propionaldehyde and a protein are recognized; conjugates obtained with other aldehydes are not reactive. Results conceming the formation of acetaldehyde adducts with carrot (Daucus carota L.) proteins are presented as well as the presence of such conjugates in ethanoltreated carrot cell cultures, a system highly sensitive to the presence of ethanol in the culture medium.

We report the immunization protocol used to produce high frequency of specific hybridomas secreting defined antibodies against soluble proteins. The two immunization schemes used consist in 1300 and 115 micrograms of protein distributed over a period of two weeks. The specific efficiency (SE) of positive clones recovered in eleven different fusion experiments ranged between 0.52 and 0.78. These values are referred to hybridomas secreting monoclonal antibodies (MAbs) against soluble proteins such as human chorionic somatomammotropin (hCS), human growth hormone (hGH), and human prostatic acid phosphatase (hPAP). Similar high SE were also recovered by immunizing mice with nonsoluble antigens such as intermediate filaments of cytoskeleton (IF).