A characterization and description of the Maarsseveen Lake system

The Maarsseveen Lakes system, located near the City of Utrecht, The Netherlands, consists of two major bodies of water, a larger lake (Maarsseveen I) and a smaller lake (Maarsseveen II), interconnected by a maze of channels known as a ‘petgaten’ area. The hydrodynamics of the lake region coupled with this ‘petgaten’ area are responsible for the maintenance of the relatively oligomesotrophic character of Lake Maarsseveen I, as compared with the more eutrophic lake maarsseveen II. Both lakes are plagued by problems of summer anoxia, although this phenomenon is far more pronounced in the more eutrophic small lake. Atmospheric deposition is responsible for contributions of significant quantities of trace metals to both lakes, and the River Vecht acts as an additional source for Lake Maarsseveen II.     

Localization of 1,25-(OH)2D3-responsive alkaline phosphatase in osteoblast-like cells (ROS 17/2.8, MG 63, and MC 3T3) and growth cartilage cells in culture

Previous studies have shown 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3)-responsive alkaline phosphatase in cultured growth zone cartilage chondrocytes is localized in extracellular matrix vesicles (MV). Since osteoblast-like cells also have 1,25-(OH)2D3-responsive alkaline phosphatase, this study determined whether the 1,25-(OH)2D3-responsive enzyme activity is localized to MV produced by these cells as well. Osteoblast-like cells from rat (ROS 17/2.8), mouse (MC 3T3), human (MG 63), and rat growth zone cartilage were cultured in Dulbecco's modified Eagle's medium containing 10(-7)-10(-12) M 1,25-(OH)2D3. Alkaline phosphatase total activity and specific activity were measured in the cell layer, MV, and plasma membrane (PM) fractions. MV and PM purity were verified by electron microscopy and MV alkaline phosphatase specific activity compared to PM (MV versus PM: ROS 17/2.8 6 x; MG 63, 5.5 x; MC 3T3, 33 x; GC, 2 x). There was a dose-dependent stimulation of MV alkaline phosphatase (5- to 15-fold increase at 10(-7)-10(-9) M) in all cell types in response to the 1,25-(OH)2D3. The PM enzyme was stimulated in a parallel fashion in the osteoblast cultures. No effect of 1,25-(OH)2D3 was observed in growth cartilage PM. Although MV accounted for less than 20% of the total activity they contributed 50% of the increase in alkaline phosphatase activity in the cell layer in response to 1,25-(OH)2D3 and MV specific activity was enriched 10 times over that of the cell layer. These are common features of MV produced by cells which calcify their matrix and suggest that hormonal regulation of MV enzymes may be important in primary calcification.     

Purification of the 5-hydroxytryptamine 5-HT3 receptor from NCB20 cells

A 5-hydroxytryptamine 5-HT3 receptor binding site has been purified from deoxycholate-solubilized NCB20 cell membranes. Purification (1,700-fold) was achieved in one step by affinity chromatography with L-685,603 immobilized on agarose. The 5-HT3 selective antagonist [3H]Q ICS 205-930 labeled a single population of receptors in the affinity-purified preparation with a Bmax of 3.1 +/- 0.9 nmol/mg protein and Kd of 0.40 +/- 0.05 nM (mean +/- S.E., n = 3). The rank order of potency for a series of competing compounds confirmed that [3H]Q ICS 205,930 was labeling a 5-HT3 receptor in the purified preparation, and the inhibition constants for all antagonists were unchanged after purification. The purified 5-HT3 binding site eluted from a Sepharose 6B gel filtration column in a similar manner to the crude solubilized preparation (Stokes radius of 4.9 nm, apparent molecular size 250,000). Polyacrylamide gel electrophoresis of the affinity-purified receptor showed two broad bands by silver staining, migrating with apparent molecular masses of 54,000 and 38,000. Gel filtration of the affinity purified material yielded a single peak labeled by [3H]Q ICS 205-930 with an apparent molecular size of 250,000, which was also composed of two bands of 54,000 and 38,000, consistent with these being the constituents of the 5-HT3 receptor.     

MENTAL DISORDERS OF THE AGED—The Role of the State Hospital in the Treatment; Report of a Pilot Study

The number of patients age 65 and over at the Agnews State Hospital now constitutes over one-third of the resident population. The geriatric population is increasing in all California state hospitals.Because this is a relatively new area of concern for the psychiatric institution, the role of the state hospital in the care of the aged is not yet clearly defined.A pilot study of admissions in this age group committed from one county during a 12-month period was undertaken, with an attempt made to evaluate the suitability of the patient for commitment, as well as special problems in admission, treatment during hospitalization, and release from the hospital. The study indicated 42 per cent of persons admitted were considered unsuitable for commitment. Physical illness was found to be a major factor in precipitating admission and a predominating factor in the treatment program after admission. Almost 40 per cent of the patients died within a year after admission.     

Seed Germination Studies. III. Properties of a Cell-free Amino Acid Incorporating System From Pea Cotyledons; Possible Origin of Cotyledonary α-Amylase

Pea cotyledonary alpha-amylase increases dramatically both in specific activity and total activity between days 7 to 10 when germination occurs in the dark. This enzymatic activity does not seem to appear as a consequence of release or formation of an activator, removal of an inhibitor, dissociation of an inactive amylase complex, or proteolytic decomposition of a zymogen precursor. The possibility remains that the alpha-amylase is newly synthesized during germination. The preparation and properties of a cell-free protein-synthesizing system from germinating pea cotyledons is described; polyuridylic acid must be added for l-phenylalanine incorporation. Active microsomal preparations can be obtained from cotyledons germinated 10 days.