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Esophageal functional abnormalities may lead to regurgitation, chronic esophagitis and life-threatening conditions such as aspiration pneumonia. In mixed connective tissue disease patients, previous reports showed that esophageal dysfunction varies according to the method employed for investigation. Our study was conceived to: (i) assess esophageal motility and mucosal aspects in patients with mixed connective tissue disease by endoscopy, cine-esophogram and scintigraphy focusing on the prevalence of each exam; and (ii) verify the association between pulmonary and esophageal dysfunctions. Twenty-four mixed connective tissue disease patients were enrolled for this study. Cine-esophogram and upper digestive endoscopy with mucosal biopsy were performed according to previous standardization. Radionuclide esophageal scintigraphy was performed with a semisolid meal with (99m)Tc. Eleven healthy individuals voluntarily submitted to scintigraphy as controls. Cine-esophogram showed esophageal delayed emptying in 90% of patients. At scintigraphy there was a significant delay in total esophageal transit time in the group of patients when compared to healthy controls (35.3 +/- 8.2 s. vs. 13.6 +/- 9.5 s.; P < 0.0001). The whole esophageal body showed dysmotility in 96% of patients. The cine-esophogram detected functional esophageal impairment similar to scintigraphic findings. Histopathologic examination found esophagitis in 95% of studied patients. Reduced lung volumes were associated with esophagitis and delayed esophageal clearance at scintigraphy, observed at the distal portion of the esophagus. Esophageal scintigraphy is easy to perform, with good acceptance by patients with low radiation exposition. It is a useful non-invasive test for follow-up and interventional studies concerning esophagus dysfunction.

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Shallow lakes respond in different ways to changes in nutrient loading (nitrogen, phosphorus). These lakes may be in two different states: turbid, dominated by phytoplankton, and clear, dominated by submerged macrophytes. Both states are self-stabilizing; a shift from turbid to clear occurs at much lower nutrient loading than a shift in the opposite direction. These critical loading levels vary among lakes and are dependent on morphological, biological, and lake management factors. This paper focuses on the role of wetland zones. Several processes are important: transport and settling of suspended solids, denitrification, nutrient uptake by marsh vegetation (increasing nutrient retention), and improvement of habitat conditions for predatory fish. A conceptual model of a lake with surrounding reed marsh was made, including these relations. The lake-part of this model consists of an existing lake model named PCLake. The relative area of lake and marsh can be varied. Model calculations revealed that nutrient concentrations are lowered by the presence of a marsh area, and that the critical loading level for a shift to clear water is increased. This happens only if the mixing rate of the lake and marsh water is adequate. In general, the relative marsh area should be quite large in order to have a substantial effect. Export of nutrients can be enhanced by harvesting of reed vegetation. Optimal predatory fish stock contributes to water quality improvement, but only if combined with favourable loading and physical conditions. Within limits, the presence of a wetland zone around lakes may thus increase the ability of lakes to cope with nutrients and enhance restoration. Validation of the conclusions in real lakes is recommended, a task hampered by the fact that, in the Netherlands, many wetland zones have disappeared in the past.

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Recently, it has become evident that stimulated phosphoinositide (PI) hydrolysis plays a crucial role in early T lymphocyte activation. We have investigated the effects of the nonmitogenic lectin wheat germ agglutinin (WGA) on several parameters associated with PI hydrolysis in human T cells. It was found that WGA was as effective as anti-T3 antibody and PHA in producing a rise in cytosolic free Ca++ ((Ca++)i) in blood T cells and in cells of the T cell line CCRF-CEM. It was inferred that identical cells within the blood T cell preparation responded to each of the three agents, refuting the contention that WGA only stimulated a subfraction of circulating mature T lymphocytes. WGA-induced, but not PHA-induced rises in (Ca++)i could be blocked completely by N-acetyl-D-glucosamine, demonstrating that the sugar-binding characteristics of the lectin dictate its action on T lymphocytes. Anti-T3 antibody, PHA, and WGA all initiated inositol phosphate formation in blood T cells, indicating that each of the agents stimulated PI hydrolysis. The combination of WGA with nonmitogenic amounts of phorbol-12-myristate-13-acetate resulted in strong mitogenicity. It is concluded that WGA, like anti-T3 antibody and PHA, is a pan-T activator of PI hydrolysis.

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Aqueous extracts of sheep pineal bodies were separated on Sephadex G-25. A low molecular Sephadex G-25 fraction F4 was filtrated on Sephadex G-10. Several distinct peaks could be detected showing excitation and fluorescence maxima resembling those of indoles. A thinlayer chromatography study revealed that one Sephadex G-10 peak contained a spot identical with that of synthetic 5-methoxytryptophol, another a spot with the same Rf-values in different solvents as synthetic 5-hydroxytryptophol, while from a third peak a substance was isolated identical with synthetic melatonin. Mass spectra of the isolated compounds were recorded. These results are compared with those of previous isolation studies.

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