COMPARISON OF VARIOUS APPROACHES TO DETERMINING CO2 FLUXES FROM THE SOIL BY 222Rn CALIBRATED METHOD.

Various approaches of determining CO2 fluxes from the soil based on 222Rn calibrated method were tested. It was shown that the exponential fits of CO2 and 222Rn depth profiles led to uncertainties up to 50% if the depth profiles of CO2 and 222Rn concentration were not measured at sufficient depths. However, CO2 fluxes determined from linear fits of CO2 and 222Rn concentrations in the surface layer of the soil are lower than the fluxes determined from exponential fits, and have lower uncertainties. The comparison of CO2 fluxes derived from 222Rn calibrated methods with directly measured CO2 fluxes showed that the latter are usually on the order of tens of percent higher than the former. CO2 flux from sandy-clay and uncultivated soil was estimated to be on the level of 3.0 mmol m-2 h-1 in the spring and around 7.0 mmol m-2 h-1 in the summer.

RADON CONCENTRATIONS IN SELECTED THERMAL WATERS IN SLOVAKIA.

Radon concentration in thermal waters used in selected spas and aqua parks in Slovakia was investigated. In total, 23 thermal water sources were monitored. Measured radon levels varied in a large interval, from 4.1 to 488 Bq l-1. High radon activity (180 Bq l-1) was also found in thermal potable water in fountains used by the patients and the public.

[Nontuberculous mycobacteria and incidence of mycobacterioses in Prague in 1999-2004]. / Netuberkulózní mykobakteria a mykobakteriózy v Praze v letech 1999-2004.

OBJECTIVE: To analyze the incidence of nontuberculous mycobacteria detected in Prague patients in 1999-2004 as either single findings suggestive of clinical insignificance or repetitive findings suggestive of mycobacteriosis when reported together with the corresponding organ damage and symptomatology. MATERIAL AND METHODS: Nontuberculous mycobacteria were isolated and identified according to the Czech recommended methods for mycobacterial diagnosis in two Prague laboratories. The determined incidence rates of Mycobacterium (M.) kansasii, M. avium complex (MAC) and M. xenopi were compared with the respective nationwide rates and those of other nontuberculous bacteria, M. tuberculosis and M. bovis. The data on cases of mycobacterioses reported within the Czech Registry of Tuberculosis were provided by the Institute of Health Information and Statistics of the Czech Republic. RESULTS: In 1999-2004, the annual incidence rates of nontuberculous mycobacteria detected in Prague patients ranged between 169-139 and accounted for 13-25% of the totals of isolated mycobacteria including M. tuberculosis and M. bovis. Over this period, M. kansasii, MAC and M. xenopi were detected in 45, 76 and 43 patients, respectively. The single to repetitive detection ratio was the highest for M. kansasii (1:1.6), followed by MAC (1:1.8) and M. xenopi (1:2.3). Most male excretors were from higher age categories (median of 58-73 years) while the median age of female excretors ranged between 41 and 75 years. As many as 47 cases of mycobacterioses caused by the following agents: M. kansasii (20 cases), MAC (17 cases), M. xenopi (6 cases) and other nontuberculous mycobacteria (4 cases), were reported to the National Registry of Tuberculosis over the study period. CONCLUSIONS: Detection and identification of nontuberculous mycobacteria have become part of diagnostic routine of mycobacteriological laboratories. Compared to conventional tuberculous mycobacteria, detection of nontuberculous mycobacteria often requires the use of different and more cumbersome procedures such as incubation at preferential temperatures, longer incubation for detection of growth in primary cultures, species specific culture media, etc.. More skills and experience are needed for the use of automated detection systems and molecular biological techniques for species identification and interpretation of results. Regular consultations with clinical and outpatient physicians are crucial for the assessment of pathogenetic potential of nontuberculous mycobacteria.

Insulin immunization of guinea-pigs: biochemical, immunohistochemical and morphometric findings with and without the use of adjuvant.

Changes in the blood glucose level, glucose (GTT) and insulin (ITT) tolerance tests, anti-insulin antibody production and morphological changes in pancreatic tissues (in particular the islets of Langerhans) were studied. After immunization by insulin (I) or insulin combined with an adjuvant (IE, IF), the blood glucose level rose, changes were observed in the GTT and ITT and after four successive immunizations the immunofluorescence technique also demonstrated anti-insulin antibodies. None of the above changes was observed in the controls, to which saline containing complete Freund adjuvant (SF) or Listeria factor (SE) was administered. On the other hand, the morphological picture changed in both the experimental (IE, IF) and control (SE, SF) groups, in which (round) cell infiltration of the fine connective tissue of the omentum and even of mesentery, with nonspecific granuloma formation was observed, while huge multinuclear cells appeared in the SF group. The changes were more frequent in the IE and IF groups. The volume density of the pancreatic endocrine tissue increased significantly only in the experimental groups (I, IE, IF), in which the increase was accompanied, to a varying degrees, by degranulation of the B-cells. The results of analysis of volume density changes of A-, B-, and D-cell populations were correlated with the blood glucose levels. The morphological findings may explain why the originally insignificant production of anti-insulin antibodies and the increase in the blood glucose level observed in guinea pigs after the repeated administration of chromatographically purified insulin are significantly enhanced by the administration of adjuvants together with the immunizing agent. Complete Freund adjuvant was found to be more effective than the Ei Listeria factor.

Immunodiabetes in rabbits.

The changes of basal glycemia and of that during the glucose and insulin tolerance tests as well as of the production of hemagglutinating antibodies in rabbits immunized with crystalline insulin (CI), chromatographically purified insulin (CPI) and waste products of the chromatographic purification of insulin (WP), both with and without complete Freund's adjuvant (CFA) were studied. Following immunization with CI and its components the glycemia increased characteristically and the course of glucose and insulin tolerance tests was changed. The peak levels of antibodies were found following immunization with WP, while the lowest ones appeared following the application of CPI. Following the immunization with a mixture of antigens with CFA higher levels of antibodies were usually observed than following the administration of antigens without adjuvant. No association was found between the titers of antibodies and glycemia values. The principal morphological change in immunized animals was found to be a partial degranulation of B-cells, often accompanied by hyperplasia of A-cells. In groups immunized with CI or CPI mixed with CFA we detected even insulitis, which was absent in the other groups. Following immunization with CI mixed with CFA such cells were found whose granules in the ultrastructure showed conspicuous similarity to those of foetal (immature) rabbit B-cells. It was assumed that in insulin immunized rabbits the initial damage of islets was followed, at least in some regions, by reparative processes. This was indicated by the findings of mitosis figures in B-cells as well as by the islet A-cell hyperplasia.