[Virology, diagnostic tests, epidemiology and transmission mechanisms of hepatitis C virus infection]. / Virología, pruebas diagnósticas, epidemiología y mecanismos de transmisión del VHC.

The hepatitis C virus is a human virus, classified within a third type (Hepacivirus) of the Flaviviridae family. It is a spherical virus, of approximately 50 nm in diameter, with a glycoprotein covering that contains lipids, and its genome is a simple chain RNA molecule. It is characterised by a high degree of genomic heterogeneity, whose evolutionary consequence in the long term is the appearance of genetically different viral groups, genotypes and quasispecies. There are different diagnostic techniques for detecting hepatitis C virus infection. Serological assays: the detection of specific IgG against HCV by means of enzyme immunoassays is the most practical method for diagnosing infection by this virus. Supplementary immunblot tests are employed to confirm the specificity of the results of the EIA test. Molecular assays: qualitative and quantitative techniques have been developed for detecting RNA-HCV, based on the direct detection of the virions. The pathogeny of hepatitis C is not well understood. Its world prevalence is estimated at some 3%, which is why routine screening for its detection is not recommended. HCV transmission basically occurs through percutaneous exposure to infected blood, with higher rates observed in imprisoned persons, vagabonds, intravenous drug addicts, haemophiliacs and patients on haemodialysis. Although it can be transmitted sexually, it seems that this path is not very efficient, with a greater prevalence observed in persons with multiple sexual partners. Vertical transmission is estimated at some 2%, reaching 20% in cases of maternal coinfection with HIV.

[Dysphagia as an unusual form of presentation of malignant pleural mesothelioma]. / Disfagia como forma de presentación inusual en mesotelioma pleural maligno.

Dysphagia is an unusual presenting symptom as of extradigestive tumors. Malignant mesothelioma, is a rare tumor localized in the pleural cavity in 80% of all cases and it rarely appears with dysphagia as first symptom. We describe the case of a 74-year-old woman admitted with progressive dysphagia for solid and liquid food, atypical epigastric pain, with in conclusive endoscopic and radiologic studies. Nuclear Magnetic Resonance established the diagnostic suspicion of malignant mesothelioma which was confirmed by the histologic study of a biopsy taken by thoracotomy. We think of interest to report this case of paraesophageal mesothelioma because of its unusual localization and presentation.

[Complications and possible risk factors in endoscopic polypectomy of the colon]. / Complicaciones y eventuales factores de riesgo en la polipectomía endoscópica del colon.

We review the incidence of iatrogenic complications in a serie of 661 patients who underwent endoscopic polypectomy, performed by the same team of endoscopists and using similar technique. We discuss the role of age, sex, associated diseases, coagulation abnormalities and polyp features (size, location, shape and malignancy) in the development of complications. Five severe complications (0.75%, 3 hemorrhages and 2 perforations) were detected. Two patients required blood transfusion and two other patients surgical treatment. Recovery was successful in all patients. In eight patients (1.21%) mild complications which did not required further treatment were present. According to previously published data, these results are satisfactory. Polyp size proved to be the only risk factor with statistical significance; 23.36 +/- 14.17 mm. in complicated polypectomies vs 8.12 +/- 4.21 mm. in non-complicated cases (p less than 0.001). The remaining parameters analyzed showed no significance and therefore no predictive value.

[Primary biliary cirrhosis in Navarra]. / Cirrosis biliar primaria en Navarra.

50 cases of PBC registered in Navarra during 1974-1987 were studied retrospectively. 38% of the diagnosis were carried out in the non-symptomatic period. There were no histological differences between symptomatic (2.24 +/- 1.16) periods. In the first group the delay in diagnosis was very high: 28.21 months, the jaundice being followed by itching of 11.65 months duration. The rate of PBC has increased progressively, rising to a global incidence of 25.15/million and 78.03/million for women over 25 years old. There figures are 3 and 9 times higher than those published in spanish and most foreign literature. We did not find any significant differences between the several health service areas in Navarra, nor between rural or urban areas. Our paper brings to the fore this question: is Navarra an area of especial prevalence of PBC or does it simply offer better diagnosis conditions?