Intestinal mucosal as well as extramucosal antibody responses were studied in mice after peroral immunizations with cholera toxin or cholera B subunit. The immunizations with cholera toxin gave rise ...to a marked response with antitoxin-secreting cells (PFC) in Peyer's patches (PP), mesenteric lymph nodes (MLN) and spleen showing isotype distribution of IgG greater than IgA greater than IgM and with PFC kinetics in MLN and spleen that suggested migration of cells from PP after peroral administration rather than cells stimulated in situ by adsorbed antigen. Highest numbers of PFC were obtained after 2 immunizations, and further administrations resulted in a decrease in the PFC response in MLN and spleen, while the PP responsiveness was relatively unchanged, and interestingly, protective immunity and IgA-dominated antitoxin titers in intestinal washings increased markedly by the additional boosters. Animals immunized with cholera B subunit, which lacks the adenylate cyclase-stimulating capacity of cholera toxin, showed similar PFC responses in extramucosal organs as those receiving cholera toxin but were poorly protected and had correspondingly lower IgA antitoxin titers in intestinal washings. These results suggest that the mucosal IgA antitoxin predominance is mainly due to regulatory mechanisms operating on the end-stage differentiation of the committed B cells in lamina propria and that this differentiation, as judged from the different results with cholera toxin and its B subunit, might be influenced by cyclic AMP.
Lectins with narrow oligosaccharide specificities were established as probes to study the host cell influence on the biosynthesis of O-linked oligosaccharides of the herpes simplex virus type 1 ...(HSV-1)-specified glycoprotein C (gC-1). We found that only gC-1 and no other glycoprotein bound to the peanut lectin (PNA), with main specificity for Gal(β1–3)GaINAc. Previously, we have shown that only gC-1 binds to the
Helix pomatia lectin (HPA), with main specificity for terminal GaINAc. The O-linked oligosaccharides binding to PNA and HPA were released by alkaline borohydride treatment and characterized. A structural determination of these oligosaccharides showed that the HPA-binding carbohydrates were monosaccharides (GaINAc), and that the PNA-binding oligosaccharides were disaccharides with the structure Gal-GaINAc. The PNA- and HPA-binding oligosaccharides were arranged as Pronase-resistant clusters on gC-1, consisting of about seven individual, adjacent oligosaccharides. In addition to these disaccharides, Pronase-resistant PNA-binding glycopeptides of gC-1 also contained neutral trisaccharides. Larger O-linked oligosaccharides, binding to the wheat germ lectin, were found in gC-1, but not in proximity to the PNA-binding ones. It was concluded that the lectins mentioned should be useful probes in screening HSV-infected cells of different lineages for differences in processing of 0-linked oligosaccharides.
Between 3 and 6 of 12 colorectal neoplasms larger than 1 cm in diameter were overlooked by each of 4 radiologists in 117 individuals investigated with double-contrast enema (DCE) after a positive ...guaiac test. Even when the individual results of 2, 3, or 4 experienced radiologists were combined, 2 small carcinomas were overlooked due to perception errors. One of these carcinomas was diagnosed by rectosigmoidoscopy, which is an important and necessary complement to DCE. Although small carcinomas may be missed even with this combination, meticulous exploitation of the 2 methods is absolutely necessary to minimize the risk of missing a colorectal neoplasm. A drawback when 2 or more radiologists read the radiographs is the increased number of false-positive findings.
The glacial history of Svalbard and the Barents Sea during the Late Weichselian has been much debated during the last few years; reviews are presented by Andersen (1981), Boulton et al. (1982), ...Elverhoi & Solheim (1983) and Vorren & Kristoffersen (1986). In our opinion (Mangerud et al. 1984) it is now demonstrated that a relatively large ice-sheet complex existed over most of Svalbard and large parts (if not all) of the Barents Sea. One of the main arguments for a large ice sheet is the pattern of uplift, including the 9,800 B.P. date on the 100 m shoreline in Kong Karls Land (Salvigsen 1981). Important unresolved problems include how large that ice sheet was, the location of the different ice domes and ice fronts, the age and duration of the glacial maximum, and the deglaciation history. We will here report on these problems bringing some results from the Van Mijenfjorden and Isfjorden area (Fig. 1); a more comprehensive paper is in preparation.
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