Neustonic versus epiphytic bacteria of eutrophic lake and their biodegradation ability on deltamethrin

This study evaluated biodegradation of the insecticide deltamethrin (1 μg l−1) by pure cultures of neustonic (n = 25) and epiphytic (n = 25) bacteria and by mixed cultures (n = 1), which consisted of a mixture of 25 bacterial strains isolated from the surface microlayer (SM ≈ 250 μm) and epidermis of the Common Reed (Phragmites australis, (Cav.) Trin. ex Steud.) growing in the littoral zone of eutrophic lake Chełmżyńskie. Results indicate that neustonic and epiphytic bacteria are characterized by a similar average capacity to degrade deltamethrin. After a 15-day incubation, bacteria isolated from the surface microlayer reduced the initial concentration of deltamethrin by 60%, while the average effectiveness of the bacteria found on the Common Reed equaled 47%

IgM antibody to the hepatitis B core antigen in acute hepatitis determined by SPRIA--diagnostic value

A solid phase radio-immunoassay (SPRIA) was developed for the detection of anti-HBc IgM. The assay proved sensitive and easy to perform and rheumatoid factor did not affect the test results. Anti-HBc IgM titres were followed in consecutive samples from 15 patients after uncomplicated acute hepatitis B. In the acute phase anti-HBc IgM titres ranged from 10(-5) to 10(-7) (mean 10(-6.4)). One year after onset of disease ten of the 15 had titres below 10(-4) and between two and three years after onset most patients had titres 10(-3). Anti-HBc IgM titres were determined in six episodes of acute hepatitis B, all HBsAg negative but anti-HBc positive in the first samples obtained (within 8 days) and developing anti-HBs during convalescence. Acute phase anti-HBc IgM titres in these patients ranged between 10(-5.5) and 10(-7) (mean 10(-6.5)) and were thus identical with HBsAg positive cases. When acute phase sera from 168 episodes of acute hepatitis primarily classified as non-A, non-B, were tested for anti-HBc IgM titres above 10(-5), sera from 13 episodes were positive and in seven of these hepatitis B diagnosis could be confirmed by rising anti-HBs titres in convalescence. Sera from four of the 13 patients contained HBeAg, which was thus demonstrated in the absence of HBsAg. The results show that testing for anti-HBc IgM is important for a true non-A, non-B diagnosis