Acetylcholinesterase during the development of the sea urchin Pseudocentrotus depressus was examined by enzyme assay (the colorimetric method of ELLMAN et a/.), histochemistry (a Cu-thiocholine method), polyacrylamide gel electrophoresis and DEAE-Sephadex ion exchange chromatography.The enzyme activity is detected in the unfertilized egg, remains low during cleavage, elevates slightly through gastrulation, and then increases rapidly thereafter. The intense activity is localized in the mesenchyme cells associated w8h the larval skeleton of young pluteus larvae, and their cell membranes and nuclear envelops.Soluble enzyme accounts for 60% of the total activity. The additional 34% is extracted by 1% Triton X-100 from particulates. The soluble enzyme consists of two forms. Both are strongly acidic proteins which are similar in electric charge, but dissimilar in size, being 180,000 and 280,000 in molecular weights. The enzyme released from the membrane by the detergent possesses a component which is not present in the soluble complement of the enzyme. It is not a secondary product of the soluble enzyme interacting with the detergent.Acetylcholinesterase serves as a marker of late differentiation and regional differentiation in the sea urchin embryo.The sea urchin embyro possesses the enzyme which hydrolyzes acetylcholine. AUGUSTINSSON and GUSTAPSON (1949) found that (1) the enzyme is a true acetylcholinesterase, the type found in erythrocytes and nerve cells of the vertebrate, and (2) a sharp rise in the activity occurs at the end of gastrulation.Since the occurrence of this enzyme is usually restricted to excitable cells such as nerve and muscle (NACHMANSOHN, 1970), it was thought possible that the enzyme might be localized in certain parts of the embryo, and thus may serve as a marker of both temporal and regional differentiation. Such a finding would provide a handle to explore further the problem of determination in echinoderm development, and the regulation of gene activity during development. The present paper will show that the enzyme activity is localized in the mesenchyme cells of

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Background:Although it is well known that exercise affects various immune functions, it remains to be determined whether exercise influences change in the mucosal immunity of elderly people. The objective of the present study is to examine whether low-intensity short-term exercise alters acute and long-term mucosal immune function in communitydwelling elderly people. Methods:The subjects of the study were 16 community-dwelling elderly people, consisting of 11 men and five women aged 60-94 (mean ± SD, 76 ± 10 years), living in Sanbongi Town (Miyagi, Japan). The subjects periodically performed about 20 min of lowintensity physical exercise (approximately 3.1 METS) at a frequency of twice a month for 3 months. Saliva samples were collected before and after exercise during the exercise class (at the start, after 1 month and after 3 months). Saliva flow, secretory immunoglobulin A (SIgA) concentration, SIgA secretion rate and total protein were determined. Results:The main finding was that saliva flow and SIgA secretion rates were significantly (P < 0.05) higher after exercise. However, the baseline value of SIgA level hardly changed at each point for the duration of the exercise class. Conclusions:The results suggest that low-intensity short-term exercise enhances mucosal immune function transiently in elderly people.

A high-molecular-weight glycoprotein with a sedimentation coefficient of 22.6 has been isolated and characterized from the accessory cells in the previtellogenic ovary of the echinoid Dendraster excentricus. This glycoprotein is similar to the major yolk glycoprotein of the mature egg in its electrophoretic mobility under non-denaturing conditions, high mannose-type glycan, amino acid composition, constitutive glycopeptides, and immunological determinants. Previous histological and electron microscopical analyses led to the hypothesis that vitellogenesis involves a translocation of material from the accessory cell in the ovary to the oocyte. Because of the close similarities of the accessory cell glycoprotein to the yolk glycoprotein of the mature egg, we conclude that the glycoprotein in the accessory cell is a precursor to the major glycoprotein of the egg yolk. This conclusion is further supported by our additional finding that the accessory cell of another echinoid, Strongylocentrotus purpuratus, also contains a high-molecular-weight (24 S) glycoprotein which shows similarities to the yolk glycoprotein of the mature egg in the carbohydrate moiety and the constitutive glycopeptides.