[The LMP1 oncogene sequence variations in patients with oral tumours associated or not associated with the Epstein Barr].

The role of the Epstein-Barr virus (EBV), a ubiquitous lymphotropic human herpesvirus type 4, in the etiology of nasopharyngeal carcinoma (NPC) is not fully understood. The mechanism of NPC carcinogenesis, associated with the virus, is also not clear. The objective of present investigation was to carry out comparative analysis of the structure of an LMP1 oncogene of EBV in viral isolates obtained from patients with two types of tumors of the oral cavity: (a) associated (i.e., NPC) and (b) not associated (other tumors of the same anatomical region, OTOC) with EBV. Comparative analysis of C-terminal regions of LMP1 variants that was based on a sequence analysis of LMP1 from tumor, blood and throat washing samples of NPC and OTOC patients showed that all structural characteristics of LMP1 in both groups of patients were genetically similar, and differences found between compared parameters were statistically insignificant. Thus, for the first time it has been revealed that in NPC and OTOC patients in Russia genetically related EBV strains with structurally similar LMP1 variants are persisting that are likely to reflect a polymorphism of the virus circulating in population. The findings allow us to suggest that in non-NPC-endemic regions of the world, which include Russia, the risk of NPC development does not depend on the EBVstrain and its variant of LMP1 so much, but mostly from the genetic predisposition of infected persons to the disease and the exposure to other, as yet unknown agents.

[Analysis of mortality in Russian population].

Abrupt mortality growth in Russian population began in 1991 and continued until 1994. Mortality lowered between 1994 and 1998, after which its fast growth resumed. These fluctuations to a significant degree result from increases and decreases in mortality related to cardiovascular diseases (CVD), particularly to "other forms of acute and chronic ischemia" and "atherosclerotic heart disease", but not to myocardial infarction, the proportion of which in Russian CVD-related mortality is extremely low. At the same time, the proportion of CVD-related deaths registered as "other" and "not specified", was more than 50%. It may suggest that in Russian statistics CVD-related mortality is overestimated, while mortality related to external causes (EC) associated with alcohol intoxication is underestimated. Analysis of forensic postmortems supports this assumption. The authors found that ethanol was very often revealed in the blood of persons with a diagnosis of "other causes" or "non-specified" CVD. On the average, in more than 20% of postmortems ethanol blood levels were potentially or actually lethal, i.e. in fact, the reason for death was alcohol intoxication, not CVD. In persons with a postmortal diagnosis of EC the frequency of ethanol detection was also very high (55 to 70%). Potentially and actually lethal ethanol concentrations were found in one third of all men and women with a postmortal diagnosis of EC. Thus, the authors of the article stress that official statistical data, according to which 65199 or 2.8% of all deaths in Russia in 2004 were caused by alcohol intoxication are in contradiction with their data and data of other authors. The results of the present study demonstrate that alcohol intoxication due to its overuse is an important reason for extreme mortality rate in Russian population.