Co-morbidity of infectious and addictive diseases in St. Petersburg and the Leningrad Region, Russia.

The Russian health care system is organized around specific diseases, with relatively little focus on integration across specialties to address co-morbidities. This organizational structure presents new challenges in the context of the recent epidemics of injection drug use (IDU) and HIV. This paper uses existing and new data to examine the prevalence of reported new cases of drug dependence (heroin) and HIV over time as well as associations between drug dependence and alcoholism, hepatitis B and C, and tuberculosis in the City of St. Petersburg and the Leningrad region. We found a sharp rise in reported cases of IDU beginning in 1991 and continuing until 2002/2003, followed by a sharp rise in newly reported cases of HIV. These rises were followed by a drop in new cases of HIV and drug addiction in 2002/2003 and a drop in the proportion of HIV-positive individuals with IDU as a risk factor. Infection with hepatitis B and C were common, especially among injection drug users (38 and 85%, respectively), but also in alcoholics (7 and 14%). Tuberculosis was more common in alcoholics (53%) than in persons with alcoholism and drug dependence (10%), or with drug dependence alone (4%). Though these data have many limitations, they clearly demonstrate that drug dependence and/or alcoholism, HIV, hepatitis, and tuberculosis frequently co-occur in St. Petersburg and the Leningrad Region. Prevention and treatment services across medical specialties should be integrated to address the wide range of issues that are associated with these co-morbidities.

The effect of oxidative stress on structural transitions of human erythrocyte ghost membranes.

Differential scanning microcalorimetry was used to study the effect of oxidative stress induced by cumene hydroperoxide (CHP) and Fe2+ on structural transitions of membranes of human erythrocyte ghosts. The CHP homolysis was shown to cause: (a) reduction of the intensity of all structural transitions with the disappearance of B1- and D-transitions; (b) decrease in the enthalpy of oxidized membrane denaturation; (c) negative slope of thermograms; (d) anomalous growth of heat absorption by membranes above 72 degreesC. All these changes occurred until the ratio Fe2+/CHP/membranes<0.02:0.05:1 was reached, i.e., prior to the moment of maximal level of TBA-RS in membrane ghosts. We interpret changes in the character of heat absorption by oxidized membranes as perturbations in the structural organization and interactions inside the spectrin-actin-protein 4.1 domains, the spectrin-protein 4.2 domain, as well as inside the domain of spectrin-ankyrin-cdB3 and the domain formed by the msdB3. These perturbations are associated mainly with the decrease in the concentration of native protein in the domains because of oxidative aggregation of proteins, as evidenced by SDS electrophoresis of oxidized membranes. Preincubation of membranes with tocopherol did not block the aggregation of proteins in electrophoresis and the decrease in the intensity of structural transitions, whereas it blocked completely the formation of TBA-RS, changes in the thermogram slope and the sharp rise in the heat absorption above 72 degreesC. This proves that these processes are determined by the thermotropic properties of the oxidized lipid bilayer of membranes and also provides evidence that the degradation of PUFA of phospholipids modifies both the structure of protein domains and the physical properties of the lipid bilayer of membranes.