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Sediment cores from four small oligotrophic boreal lakes, with minor acidification, in remote regions of central Sweden were used for historical interpretation of their metal content, with focus on Cu, Cd, Pb and Zn in Lake Stensjön, which has the longest sediment record (at least two centuries according to 210Pb dating). Comparison is made with the other three lakes. Major and trace elements in lake water, porewater and the acid-leached (HNO3) solid sediment phase was analysed with ICP-MS. In addition, general lake water chemistry, TOC and principal anions were measured in the aqueous phases. Redistribution processes were interpreted from geochemical modelling. The solid/solution distribution of pe/pH sensitive elements, indicates a minor diagenetic redistribution and the concentration profiles are therefore suitable for chronological evaluation. The ratios of Al, Ti, Sc and V, indicated a qualitative shift of sedimenting material a century ago, which did not have any impact on the retention of trace elements. Lead had a concentration profile, supported by the 206Pb/207Pb ratio, where it was possible to distinguish preindustrial conditions, early industrialisation in Europe, industrialisation in Sweden, and the use of leaded petrol after the Second World War. Cadmium showed a similar concentration pattern. The zinc profile resembled that of cadmium, but with less enrichment. Local lithogenic sources are believed to be quantitatively important. The solid/solution distribution (Kd) was independent of depth for all four elements. The sediment concentrations of copper and zinc are not related to early industrialisation but its concentration has doubled since the Second World War.

Spontaneous reporting of adverse drug reactions (ADRs) remains one of the most effective methods to detect new and serious drug reactions. However, it is well known that there is a high degree of under-reporting. This study was carried out as an attempt to improve and increase the reporting of ADRs by investigating the utility of nurses reporting in addition to physicians, as usual. During a 12-month study period, nurses working at two departments of geriatric medicine in northern Sweden received special instruction regarding drugs and ADRs, ADR reporting and special aspects of ADRs in elderly people. The reports from the nurses were scrutinized concerning the seriousness of the reaction, reported drugs and type of reaction (type A or B). All nurses working at the two departments (117) were eligible to report but in practice only those attending the teaching sessions did so. A comparison with historical reporting and with reporting from other geriatric departments in Sweden was also carried out. At the end of the study all participating nurses received a questionnaire aimed at investigating their attitudes towards ADR reporting. After the 12-month study period 18 ADR reports involving 22 reactions had been received. Seven of these were assessed as serious reactions. All of the reactions were of type A. In comparison, during the corresponding time period from the study clinics during the preceding year, only two reports were registered. During the study period only 15 reports were registered from the other 50 geriatric departments in Sweden. Even though the total number of ADR reports was small, our data indicate a substantial increase in the reporting rate. This indicates that instructed and interested nurses could play an important role in detecting and reporting suspected ADRs. Copyright © 2002 John Wiley & Sons, Ltd.

The B-subunits of cholera toxin (CTB) and Escherichia coli heat-labile enterotoxin (LTB) are structurally and functionally related. However, the carbohydrate binding specificities of the two proteins differ. While both CTB and LTB bind to the GM1 ganglioside, LTB also binds to N-acetyllactosamine-terminated glycoconjugates. The structural basis of the differences in carbohydrate recognition has been investigated by a systematic exchange of amino acids between LTB and CTB. Thereby, a CTB/LTB hybrid with a gain-of-function mutation resulting in recognition of blood group A and B determinants was obtained. Glycosphingolipid binding assays showed a specific binding of this hybrid B-subunit, but not CTB or LTB, to slowly migrating non-acid glycosphingolipids of human and animal small intestinal epithelium. A binding-active glycosphingolipid isolated from cat intestinal epithelium was characterized by mass spectrometry and proton NMR as GalNAcalpha3(Fucalpha2)Galbeta4(Fucalpha3)Glc NAcbeta3Galbeta4Glc NAcbeta3Galbeta4Glcbeta1Cer. Comparison with reference glycosphingolipids showed that the minimum binding epitope recognized by the CTB/LTB hybrid was Galalpha3(Fucalpha2)Galbeta4(Fucalpha3)GlcNAc beta. The blood group A and B determinants bind to a novel carbohydrate binding site located at the top of the B-subunit interfaces, distinct from the GM1 binding site, as found by docking and molecular dynamics simulations.

Three variants of the cholera toxin B subunit (CTB) were generated by site-specific mutagenesis in which regions of the mature protein were altered to the composition found at the corresponding positions of the closely related B subunit of the heat-labile enterotoxin of enterotoxigenic Escherichia coli (LTB). The mutant proteins were expressed in Vibrio cholerae and purified from the growth medium. In the first of the mutant proteins, the first 25 amino acids corresponded to the sequence found in LTB, and in the second, changes were made at positions 94 and 95 of the mature protein. The third mutant protein combined the changes made in the first two. Analysis of the immunological properties of these novel proteins by using monoclonal antibodies and absorbed polyclonal antiserum demonstrated that they had acquired LTB-specific epitopes. Immunizations with the mutant proteins resulted in antisera containing LTB-specific as well as CTB-specific and cross-reactive antibodies. The sera were also found to be more strongly cross-reactive in the in vitro neutralization of both cholera toxin and heat-labile enterotoxin than were antisera raised against either CTB or LTB. The results suggest that such hybrid CTB-LTB proteins may be useful in a broad-spectrum vaccine against enterotoxin-induced diarrhea.

Summary Melatonin concentrations in serum and urine were examined following oral administration of melatonin to dogs. Four different doses of melatonin ranging from 10 to 80 mg per kg of body weight were given. Melatonin was rapidly absorbed and reached a maximum serum level after 20–30 min, with a distribution phase of 3.5 hours and elimination half life (t1/2) of 5 hours. The fraction excreted in the urine was 0.25% of the administrated dose during the first 5 hours. These results as well as the diurnal rhythm of serum melatonin in the dog are similar to corresponding data reported in the human.

Three variants of the cholera toxin B subunit (CTB) were generated by site-specific mutagenesis in which regions of the mature protein were altered to the composition found at the corresponding positions of the closely related B subunit of the heat-labile enterotoxin of enterotoxigenic Escherichia coli (LTB). The mutant proteins were expressed in Vibrio cholerae and purified from the growth medium. In the first of the mutant proteins, the first 25 amino acids corresponded to the sequence found in LTB, and in the second, changes were made at positions 94 and 95 of the mature protein. The third mutant protein combined the changes made in the first two. Analysis of the immunological properties of these novel proteins by using monoclonal antibodies and absorbed polyclonal antiserum demonstrated that they had acquired LTB-specific epitopes. Immunizations with the mutant proteins resulted in antisera containing LTB-specific as well as CTB-specific and cross-reactive antibodies. The sera were also found to be more strongly cross-reactive in the in vitro neutralization of both cholera toxin and heat-labile enterotoxin than were antisera raised against either CTB or LTB. The results suggest that such hybrid CTB-LTB proteins may be useful in a broad-spectrum vaccine against enterotoxin-induced diarrhea.

The original article to which this Erratum refers was published in Pharmacoepidemiology and Drug Safety 11(8): 647–650.

The carbon K emission spectrum of gaseous ethene (C2H4) has been recorded in high resolution utilizing a grazing incidence technique. The spect