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Summary. Hepatitis C virus (HCV) is a worldwide health problem. No vaccine is available against this pathogen and therapeutic treatments currently in use are of limited efficacy. In the present study, the immunogenicity of the therapeutic vaccine candidate CIGB-230, based on the mixture of pIDKE2, a plasmid expressing HCV structural antigens, with a recombinant HCV core protein, Co.120, was evaluated. CIGB-230 was administered by intramuscular injection on weeks 0, 4, 8, 12, 16 and 20 to 15 HCV-chronically infected individuals, non-responders to previous treatment with interferon (IFN) plus ribavirin. Interestingly, following the final immunization, neutralizing antibody responses against heterologous viral pseudoparticles were modified in eight individuals, including six de novo responders. In addition, 73% of vaccinees exhibited specific T cell proliferative response and T cell IFN-gamma secretory response 24 weeks after primary immunization with CIGB-230. Furthermore, 33.3% of individuals developed de novo cellular immune response against HCV core and the number of patients (46.7% at the end of treatment) with cellular immune response against more than one HCV structural antigen increased during vaccination (P = 0.046). In addition, despite persistent detection of HCV RNA, more than 40% percent of vaccinated individuals improved or stabilized liver histology, particularly reducing fibrosis, which correlated with cellular immune response against more than one HCV antigen (P = 0.0053). In conclusion, CIGB-230 is a promising candidate for effective therapeutic interventions based on its ability for enhancing the immune response in HCV chronically infected individuals.

Interferon alfa (IFN-alpha) is the only approved treatment for chronic hepatitis B (HBV) infection. In a non-controlled study 33 pediatric patients infected with HBV and in chronic phase of the disease were included and treated with 3 to 5 x 10(6) IU/m2 body surface of Interferon alpha 2b, 3 times per week, during 4 months. The objective was to evaluate the efficacy of the treatment in terms of the histological, biochemical and viral markers evolution of the patients. The patients were evaluated carrying out determinations of alanine aminotransferase (ALAT), HBsAg and HBeAg before treatment, at the end of the treatment and every 4 months during one year of follow-up. Liver biopsy and Knodell index determination were carried out at the beginning and upon concluding the follow-up. 39.3% of the patients concluded the treatment with normal ALAT values; 7% became HBsAg negative and 14.3% became HBsAg negative. These values ascended after follow-up to 51.5%, 11% and 37.5% respectively. The histological analysis evidenced a decrease of the Knodell index in 69% of the patients, an increase in 14.2%, and 13.8% did not show variation. Correlating the biochemical and histological responses, a favorable outcome was obtained in 36.4% of the patients, evidencing a remarkable reduction of the hepatic cytolysis. The treatment was well tolerated, being the fever the most frequent adverse events. The results confirm that interferon alfa seems to be an effective treatment for children with chronic hepatitis B.

Seven patients with active chronic hepatitis who received Interferon Alfa showed a marked humoral and histological improvement one year after the treatment was concluded, in 3 patients the hepatic histology was almost normal, 2 evolved to a persistent chronic hepatitis and only one showed deterioration. These results differed from those obtained immediately after the treatment (p 0.05). Interferon Alfa proves to be of the most usefulness in this disease, studies should be continued up to one year after the treatment has ended.

The method of cytologic samples by aspirative punction was successfully used in lesions that are accessible with common needles. The digestive tract's lesions are of more difficult access, and that is the reason why we do not known any antecedent with this method in the literature. Since 1978 we have thought about some way of taking the sample by fiberoptic devices in endoscopic explorations, adjusting to a polyethylene tube of suitable measure, as to exceed the colonoscopy, in the distal extreme, a little trocar and on its proximal extreme the adjustable part of the trocar for the adaptation of the syringe that makes the aspiration. It crosses through the biopsy channel of the colonoscope, puncturing the lesion and extracting the material by aspiration to prepare the cytologic smear, and fixing it for its further coloration and microscopic observation. We present the result of the aspirative cytology in 100 cases of tumoral or elevated lesions detected in the course of a colonoscopy, performing a comparative study with the exfoliative cytology and biopsy of the same cases, to compare the diagnostic positivity index between all the tree methods. We have studied 77 adenocarcinomas, 9 villous adenomas or polyps, 5 elevated lesions in long-evolution idiopathic ulcerative colitis and 3 inflammatory lesions. The aspirative cytology had greater positivity than the exfoliative one, complementing the judgement of biopsy studies in cases of malign neoplasia with great necrotic component. It must be underlined the utility of aspirative cytology method due to its simplicity, innocuousness and diagnostic security.

Fine structure and function are closely related in the cells of the different tissues. For this reason a comparative study combining histochemical techniques and scanning electron microscopy can result a potentially useful tool in the search for cell markers of preneoplastic stages of the colon mucosa. With this purpose, samples of normal colon mucosa, adenomatous polyps and adenocarcinomas obtained by colonoscopy were studied by histochemical techniques for the detection of epithelial mucosubstances and by scanning electron microscopy. Differences were shown in the architectural arrangement of the colon epithelium between the normal mucosa, the adenocarcinoma and the polyps studied, while between tubular an tubulovillous adenomas no marked differential ultrastructural features were found. Acid mucosubstances distribution pattern showed that sialomucin predominated in the colon mucosa harboring a carcinoma and in the tubulo-villous polyps as well as in the mucosa remote from adenocarcinoma and from the two cases of familial polyposis coli histologically considered as tubulo-villous adenomas. On the other hand tubular adenomas and normal mucosa showed a predominance of sulfomucin.