Sensory Neurons Contacting the Cerebrospinal Fluid Require the Reissner Fiber to Detect Spinal Curvature In Vivo

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Cell degeneration during early development of hymenopteran olfactory sensilla

The imaginal pore plates of Hymenoptera apocrita so far examined embody five or six envelope cells respectively. In early developmental stages, however, supernumerary envelope cells have been found. The results are discussed in the context of cell death as a developmental phenomenon.     

Comparison of intracellular glutathione and related antioxidant enzymes: Impact of two glycosylated whey hydrolysates

The effects of two glycosylated whey hydrolysates (GWH-Gal A and GWH-Gal B) on glutathione (GSH) and related antioxidant enzymes in SGC-7901 cells were evaluated. Two whey glycosylated hydrolysates promoted an increase in reduced glutathione (GSH) in normal SGC-7901 cells. GSH, glutathione peroxidase (GPx), γ-glutamine cysteine synthetaase (γ-GCS), and catalase (CAT) at 1.0 and 2.0 mg/mL in normal SGC-7901 cells were higher in the GWH-Gal A group than in the GWH-Gal B group (P < 0.05). Compared with GWH-Gal B, GWH-Gal A more strongly inhibited decreases in intracellular GSH, GPx, γ-GCS, CAT, and superoxide dismutase (SOD) in H₂O₂-induced SGC-7901 cells. Compared with GWH-Gal B, GWH-Gal A at 1.0 and 2.0 mg/mL effectively inhibited increases in lactate dehydrogenase (LDH) and malondialdehyde (MDA) in H₂O₂-induced SGC-7901 cells (P < 0.05). Therefore, GSH content and related antioxidant enzyme activity levels (GPx, γ-GCS, CAT, SOD) in both normal and H₂O₂-induced SGC-7901 cells were considerably stronger in the GWH-Gal A group than in the GWH-Gal B group.     

Determination of human factor VIII (AHG-associated protein)-antigen in endothelial cells from Xenopus laevis (XTH cells)

Summary AHG-associated protein (AHG-a.p.), the antigen of the blood-clotting factor VIII complex, is a specific endothelial cell marker. Primary (p-XTH) and established (XTH-2) endothelial cells from the hearts of Xenopus laevis tadpoles were assayed for the presence of this marker by means of immunological cross-reaction (recognition of common antigenic sites) with antiserum against human AHG-a.p. Radial imtnunodiffusion and rocket immunoelectrophoresis proved to be insufficiently sensitive, whereas immunofluorescence and a newly evaluated ELISA technique gave positive results. The very high sensitivity of the ELISA (less than 1/240000 of the AHG-a.p. in 0.1 ml human standard plasma can be detected) and the removal of interfering proteins by gel filtration also revealed the presence of AHG-a.p. in the fetal calf serum used in the culture medium; earlier investigations into this subject by a one-step radioimmunoassay had reported negative results. Specially adapted XTH-2 cells were grown in a proteinand serum-free hydrolysate medium in order to demonstrate the presence of a Xenopus-derived antigen that was immunoreactive with the anti-human AHG-a.p.     

A novel array-based assay of in situ tissue transglutaminase activity in human umbilical vein endothelial cells

Transglutaminases (TGs), a family of calcium-dependent transamidating enzymes, are involved in functions such as apoptosis and inflammation and play a role in autoimmune diseases and neurodegenerative disorders. In this study, we describe a novel array-based approach to rapidly determine in situ TG activity in human umbilical vein endothelial cells and J82 human bladder carcinoma cells. Amine arrays were fabricated by immobilizing 3-aminopropyltrimethoxysilane on glass slides. The assay was specific and highly reproducible. The average coefficient of variation betweens spots was 2.6% (n = 3 arrays), and the average correlation coefficients between arrays and between arrays/reactions were 0.998 and 0.976, respectively (n = 3 arrays). The assay was successfully applied to detect changes in TG activity induced by maitotoxin and to analyze inhibition of the TG activation with cystamine and monodansyl cadaverine. In addition, the assay demonstrated that intracellular reactive oxygen species regulate the maitotoxin-induced activation of TG. Thus, the array-based in situ TG activity assay constitutes a rapid and high-throughput approach to investigating the roles of TGs in cell signaling.     

Differential human impact and vegetation history in two adjacent Pyrenean valleys in the Ariège basin,southern France,from 3000 B.P. to the present

Detailed palynological studies in two adjoining French Pyrenean valleys, complemented by the study of archives, demonstrate that under similar climatic conditions, the forest history of each valley from the Bronze Age to present time was essentially determined by socio-economical constraints, possibly modified by natural characteristics such as topography. The studies show why the expansion of Fagus (beech) at c. 4000 B.P. was asynchronous on the northern slope of the Pyrenees and emphasize the effects of the human impact on the recent lowering of the tree-line.A contribution to the 8th IPC, Aix-en-Provence, 1992     

Drosophila female germline stem cells undergo mitosis without nuclear breakdown

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JAR human placental choriocarcinoma cells actively synthesize,take up and release polyamines

Uptake of polyamines has been investigated extensively in many cells, but not in placenta, where the polyamine– polyamine oxidase system is supposed to have an immunoregulatory function in pregnancy. Due to the importance of the transfer in this tissue, we have started this study. JAR human placental choriocarcinoma cells in monolayer at confluency were used as a model for measuring the key enzymes of polyamine synthesis and interconversion, rate of uptake and efflux, and the polyamine content. Polyamines were taken up by JAR cells and released by an independent mechanism. Ornithine decarboxylase and spermidine acetyltransferase activities and the rate of transport in and out of the cell were much higher than in other cells, such as L1210 cells. However the systems used for uptake and release appear in many respects to be similar to those observed in L1210 cells, but different from others. The uptake appears to be regulated by an inhibitory protein. Moreover, protein kinase C appears to be involved in the process. The efflux also is regulated as in L1210 cells, through control of H⁺ and Ca²⁺ concentration. In conclusion, this study shows that, in JAR cells, ornithine decarboxylase and spermidine acetyltransferase activities were much higher than in other cells, and so was the rate of transport in and out of the cells. As a result, a much higher polyamine content was observed.