Distribution of natural and anthropogenic radionuclides in sediments from the Vefsnfjord, Norway.

Areas in central Norway were heavily contaminated with fallout from the Chernobyl accident in 1986. In this study, we assess 137Cs in surface sediments and sediment cores collected in the Vefsnfjord in Nordland county. Concentrations of 137Cs in surface sediments ranged from 159 to 191 Bq kg-1 dry weight (d.w.). Sub-surface peaks of 137Cs were observed in all cores, with a maximum concentration of 432 Bq kg-1 d.w. Given that little is known about the distribution of naturally occurring radionuclides in Norwegian fjords and coastal areas, a better understanding of the total burden of radioactivity is important for the Norwegian fishing and aquaculture industries. Therefore, analyses of the natural radionuclides 40K, 226Ra, 228Ra and 210Pb were included in the study. Analyses of total sulphur (TS), total carbon (TC), total organic carbon (TOC) and grain size distribution have been performed to provide a sedimentologic context for interpreting the radionuclide results.

Geochronology of sediment cores from the Vefsnfjord, Norway.

The sedimentary environment is a repository and carrier for a variety of pollutants, and sediment transport from land to coastal areas is an important environmental process. In the present study, we use 210Pb/226Ra and 137Cs in sediment cores to assess sediment supply rates at four sites within the Vefsnfjord in Nordland county, Norway. This area was highly affected by fallout from the Chernobyl accident in 1986 and inventories of 137Cs in the fjord are much higher than in many other Norwegian fjords. Sedimentation rates between 0.042 and 0.25 g cm-2 y-1 (0.060 and 0.38 cm y-1) were determined using a combination of the Constant Rate of Supply (CRS) and Constant Flux:Constant Sedimentation rate (CF:CS) models. Well-defined 137Cs concentration peaks were used as a supplementary tool to the 210Pb dating methods.

Clustering of IgA-producing immunocytes related to HLA-DR-positive ducts in normal and inflamed salivary glands.

Ig-producing immunocytes and epithelial expression of secretory component (SC) and HLA-DR were evaluated by two-colour immunofluorescence staining in 10 normal and 20 inflamed salivary glands; the latter included specimens from 10 patients with obstructive sialadenitis and 10 with Sjögren's syndrome (SS). Epithelium adjacent to T-cell infiltrates showed extensive co-expression of SC and HLA-DR, suggesting that leucocyte-derived cytokines were responsible for this concurrent up-regulation. Clusters (greater than 2 positive cells) of IgA-producing cells were spatially related to DR-positive ducts. The possibility is discussed that DR-expressing epithelium contributes to local terminal differentiation of IgA-producing plasma cells. A cytokine-mediated up-regulation of SC that simultaneously increases the transport capacity for polymeric IgA would constitute an efficient enhancement of secretory immunity in diseased glandular tissue.

Subperiosteal transmucosal porous ceramic/titanium implants. Clinical experience from three cases.

Porous ceramic (Al2O3) material was used in combination with titanium fixtures as subperiosteal transmucosal implants in three patients at the Department of Oral Surgery and Oral Medicine, Dental Faculty, University of Oslo. Ceramic pieces were furnished with titanium receptacles and matching threaded posts. The implantation approach was based upon two stages, the first for subperiosteal placement of the ceramic onlay segment containing the titanium receptacles, and the second procedure for perforation of the mucosa and insertion of the posts intended for prosthetic use. A healing period of 8 weeks was planned between the two procedures. In one of the patients, however, the implants were removed only a few weeks after placement because of inflammation and soft tissue breakdown over the ceramic material. Reoperation was performed, however, with the same negative results. The other two individuals retained the implants, with uneventful postoperative healing periods. Between 6 and 8 weeks after mucosal perforation and insertion of the titanium posts, however, subjective and objective symptoms of infection were registered in both patients. In addition, one of the cases exhibited dehiscence and exposure of the ceramic. The implants were removed in both individuals.