Radiofrequency catheter ablation for the treatment of supraventricular tachycardias in children and adolescents

We report our experience in radiofrequency catheter ablation between April, 1992 and December, 1998, in which we treated 287 patients less than 18 years of age (mean 14.3 +/- 3.1 years) with supraventricular tachycardia. Accessory, pathways were the arrhythmic substrate in 252 of the patients (87.8%), the patients having a total of 265 accessory pathways. Atrioventricular nodal re-entry was the cause of tachycardia in 26 patients (9.0%), while atrial flutter was detected in the remaining 9 patients (3.1%). We were able successfully to eliminate the accessory pathway in 236 patients (89%), but 25 patients had recurrent arrhythmias. Ablation proved successful in all cases of atrioventricular node re-entry tachycardia, the slow pathway being ablated in 25 patients, and the fast pathway in only one case. Recurrence of the arrhythmia occurred in three patients (11.5%). We performed a second ablation in these children, all then proving successful. The ablation was successful in all cases of atrial flutter, with one recurrence (11.1%). Overall, therefore, ablation was immediately successful in 271 patients (94.4%), with a recurrence of the arrhythmia in 29 cases (10.7%). The incidence of serious complications was 2.09%. There was one late death due to infective endocarditis, 3 patients suffered complete heart block, 1 had mild mitral regurgitation, and 1 patient developed an haematoma in the groin. We conclude that radiofrequency catheter ablation can now be considered a standard option for the management of paroxysmal supraventricular tachycardias in children and young adults.     

Identification of three distinct regions of allelic deletions on the short arm of chromosome 8 in hepatocellular carcinoma.

The chromosome 8p is associated with a large number of allelic imbalances in epithelial tumors including hepatocellular carcinoma (HCC). However, no tumor suppressor gene has been identified so far in this particular region of the genome. To further clarify the pattern of allelic deletions on chromosome 8p in HCC, we have undertaken high-density polymorphic marker analysis of 109 paired normal and primary tumor samples using 40 microsatellites positioned every 2 cm in average throughout 8p. We found that 60% of the tumors exhibited loss of heterozygosity (LOH) at one or more loci at 8p with three distinct minimal deleted areas: a 13 cm region in the distal part of 8p21, a 9 cm area in the more proximal portion of 8p22 and a 5 cm area in 8p23. These data strongly suggest the presence of at least three novel tumor suppressor loci on 8p in hepatocellular carcinoma.     

Hepatitis B and primary cancer of the liver: recent data on the role of B virus in oncogenesis]

Although epidemiologic studies have clearly demonstrated the importance of the hepatitis B virus in the genesis of hepatocellular carcinoma, the molecular basis for this tumorigenic effect is still under debate. Studies of woodchucks infected with a virus closely related to the human hepatitis B virus suggest that integration of the viral DNA in the host genome often plays a direct role by activating myc cellular oncogenes through insertional mutagenesis. A similar mechanism involving other cell genes has been found less frequently in human hepatocellular carcinomas. The human hepatitis B virus may contribute to tumorigenesis in a more indirect fashion, by inducing preneoplastic liver lesions which gradually become malignant.     

Shock. Antioxidant immunologico-therapeutic replacement

Shock is a specific reaction to a non specific severe injury. The organic reaction is a biphasic (excitation/depression) threefold response: haemodynamic, hemostatic and immunologic. The physiopathology is related with changes produced by injury on macrophages, neutrophils, platelets and endothelial cells. The release of enzymes and certain vasoactive compounds enhance activation of neutrophils, which produce great amounts of free oxygen radicals. Therapy must be basically substitutive, including immunologic substitution. Therapeutic trends are based on the use of substances which can avoid the overproduction or nocive effects of free oxygen radicals.     

Mammalian hepatitis B viruses and primary liver cancer.

Hepatitis B virus is a major etiologic agent in the development of human hepatocellular carcinoma, but the precise role of the virus in the tumorigenic process is still unclear. Recent studies of naturally occurring animal models, such as woodchucks and squirrels infected with hepatitis B-like viruses (hepadnaviruses) have revealed different oncogenic strategies and outlined the predominant role of myc genes in rodent hepatomas. Higher oncogenicity of woodchuck hepatitis virus has been correlated with a direct contribution of the virus as an insertional mutagen of myc genes: c-myc, N-myc and predominantly the woodchuck N-myc retroposon. In contrast, rare viral integration events but frequent amplifications of c-myc characterize ground squirrel hepatitis virus-induced tumors, indicating that hepadnaviruses may contribute in malignant transformation through different, direct or indirect ways.     

Cost-effectiveness of the Surviving Sepsis Campaign protocol for severe sepsis: a prospective nation-wide study in Spain

Context  

Severe sepsis is associated with high mortality and increased costs. The ‘Surviving Sepsis Campaign’ (SSC) protocol was developed as an international initiative to reduce mortality. However, its cost-effectiveness is unknown.     

Clinical significance of autoantibodies to the pericentromeric heterochromatin protein 1a protein

OjectiveThe objective of the study is to determine the frequency and the clinical significance of autoantibodies to the pericentromeric heterochromatin protein 1 (HP1). So far this antinuclear antibody specificity has been mainly reported in patients with the CREST syndrome.MethodsWe screened the sera of 199 individuals, including patients suffering from various autoimmune disorders (Group I, n = 145) and non autoimmune diseases (Group II, n = 44 patients) as well as healthy individuals (Group III, n = 30). The sera were systematically tested by Western blot and ELISA using a GST–HP1α fusion protein as an antigen.ResultsAnti-HP1 antibodies were detected in 32% of patients in Group I, 11.3% in Group II and 3.3% of individuals in Group III. They could be detected in sera containing or not antinuclear antibodies detectable by indirect immunofluorescence. Anti-HP1 antibodies were mostly associated with the CREST and Sjogren's syndromes (70% and 44.4%, respectively). They could also be detected in 22.2% of patients suffering from various other autoimmune diseases. However, their negative predictive value was 94% in the CREST syndrome.ConclusionAnti-HP1 autoantibodies are associated with a large spectrum of disorders. However, they have a diagnostic value in the CREST syndrome.