Troglitazone, a PPAR-γ activator prevents endothelial cell adhesion molecule expression and lymphocyte adhesion mediated by TNF-α

Background  

Cytokine mediated induction of the mucosal addressin cell adhesion molecule-1(MAdCAM-1) expression is associated with the onset and progression of inflammatory bowel disease (IBD).     

High toxicity of the novel bloom-forming species Chattonella ovata (Raphidophyceae) to cultured fish

A toxicological study of an axenic cell line of novel species Chattonella ovata Y. Hara et Chihara (Raphidophyceae) revealed that cultured species of sea bream (Pagrus major), horse mackerel (Trachurus japonicus), and yellowtail (Seriola quinqueradiata) were killed by 4.1–6.8 × 10³, 5.4 × 10³, and 2.8 × 10³ cells/mL, respectively. The sensitivity of the gill lamellae to C. ovata differed among the fish species tested. This finding revealed that C. ovata was highly toxic to the cultured fish. Histological examination showed that edema and hyperplasia of the secondary gill lamellae of red sea bream and horse mackerel occurred when exposed to, or killed by C. ovata, whereas severe damage in the gill lamellae was not observed in yellowtail. Chattonella produced high amounts of superoxide anion radicals and hydrogen peroxide, possibly responsible for the fish death observed. Based on the results of this study and occurrence of a red tide by this organism in China in 2001, we consider this organism to be one of the harmful algae in coastal waters. This is the first report demonstrating that C. ovata is highly toxic to fish, and that it produces superoxide and hydrogen peroxide.     

Reaction equilibrium for lipase-catalyzed condensation in organic solvent systems

Lipase-catalyzed condensation in an organic solvent is useful for the syntheses of esters. To reasonably design and optimize the reaction conditions, knowledge of the reaction equilibrium is required. The interaction of water with other reactants and the quantitative predictions for adsorption of water by a desiccant are discussed. The solvent effects on the reaction equilibrium are also elucidated in mixtures of nitrile and tert-alcohol.     

Effects of Various Growth Conditions in a Chemostat on Expression of Virulence Factors in Porphyromonas gingivalis

Porphyromonas gingivalis, one of the gram-negative organisms associated with periodontal disease, possesses potential virulence factors, including fimbriae, proteases, and major outer membrane proteins (OMPs). In this study, P. gingivalis ATCC 33277 was cultured in a chemostat under hemin excess and presumably peptide-limiting conditions to better understand the mechanisms of expression of the virulence factors upon environmental changes. At higher growth rates, the amounts of FimA and the 75-kDa protein, forming long and short fimbriae, respectively, increased significantly, whereas gingipains decreased in amount and activity. In a nutrient-limited medium, lesser amounts of the above two fimbrial proteins were observed, whereas clear differences were not found in the amounts of gingipains. In addition, two-dimensional electrophoresis revealed that proteins in cells were generally fewer in number during nutrient-limited growth. Under aeration, a considerable reduction in gingipain activity was found, whereas several proteins associated with intact cells significantly increased. However, the expression of major OMPs, such as RagA, RagB, and the OmpA-like proteins, was almost constant under all conditions tested. These results suggest that P. gingivalis may actively control expression of several virulence factors to survive in the widely fluctuating oral environment.     

Hunger-induced foraging behavior of two cyprinid fish: Pseudorasbora parva and Rasbora daniconius

The feeding and swimming behaviors of Pseudorasbora parva and Rasbora daniconius (Cyprinidae) with two different prey types (Daphnia pulex and Artemia salina) at different densities (0.5, 1, 2, 5, 10, or 25 per l) were studied after 36 h of food deprivation. Full satiation was defined as the cumulative number of attacks performed until fish attain a constant attack rate which for P. parva was 425 and R. daniconius was 390 attacks. Initial feeding rates showed marked variation with prey availability. Feeding rates of fish in high prey concentrations were higher at the beginning of the experiment and decreased faster than in low prey densities. Decreases in the feeding rate at high prey densities were due to faster attainment of satiation. Feeding rates of fish across high prey densities reached a steady level after satiation. Swimming speeds of fish were inversely proportional to prey density. Moreover, the change in swimming speeds was directly related to the level of satiation. The ratios of the attack rate and the encounter rate against prey density of both fish reveal that the search for prey triggered swimming and thereby feeding during the transition from hungry to satiation. The findings of this study demonstrate that satiation plays an important role in fish foraging that should be considered a significant factor in foraging analysis.     

Trichosporon siamense sp. nov. isolated from insect frass in Thailand

A strain of yeast isolated from insect frass collected in Thailand was found to represent a hitherto undescribed species of a basidiomycetous anamorphic genus Trichosporon. It is described as Trichosporon siamense. In the phylogenetic tree based on the D1/D2 region sequences of 26S rDNA, this yeast constitutes a cluster with several Q-9 having species of Trichosporon including T. otae and T. brassicae but is clearly differentiated from these species by 1.8% or more base substitutions. In the internal transcribed spacer region (ITS1 and ITS2), this species differs from T. scarabaeorum, the nearest species, by 6.5% base substitution.     

Regulation of Toll-like receptor 4 expression in mouse colon by macrophage migration inhibitory factor

Recent studies have indicated that macrophage migration inhibitory factor (MIF) and Toll-like receptor (TLR) play an important role in the regulation of innate immune responses. In this study, we investigated the effect of MIF on the expression of TLR4, a receptor that recognizes lipopolysaccharide, in colon using MIF-deficient mice. TLR4 mRNA expression in the colon tissues was determined by northern blot analysis. Western blot analysis and immunohistochemistry in the colon tissues were performed to evaluate the expression of TLR4 protein. The expressions of TLR4 mRNA and protein were remarkably down-regulated in colon tissues of MIF-deficient mice compared with wild-type mice and up-regulated by treatment with recombinant MIF. Immunohistochemical study revealed the presence of TLR4–positive staining in mononuclear cells in the lamina propria and intraepithelial mononuclear cells as well as weak staining in epithelial cells and crypts in colon tissues of wild-type mice. In contrast, MIF-deficient mice did not show TLR4-positive staining in the colonic mucosa. In MIF-deficient mice injected with recombinant mouse MIF (rMIF), TLR4-positive staining cells were observed in colon tissues similar to the findings in wild-type mice. Administration of dextran sulfate sodium (DSS) up-regulated the expression of TLR4 in the colons of WT mice but not in those of MIF-deficient mice. Furthermore, pretreatment with rMIF up-regulated the expression of TLR4 in response to DSS in MIF-deficient mice. Our results suggest that MIF affects the expression of TLR4 in mouse colon under both normal and colitic conditions.An erratum to this article can be found at     

Decomposition of aboveground and belowground organs of wild rice (Zizania latifolia): mass loss and nutrient changes

Decomposition of aboveground and belowground organs of the emergent macrophyte Z.latifolia was investigated using a litterbag technique for a period of 359 days in a freshwater marsh in Japan. Aboveground parts were classified into: leaves, sheaths and stems. Belowground parts were classified into: horizontal rhizomes (new rhizome, hard rhizome, soft rhizome) and vertical rhizome (stembase). The decay rate (k) was 0.0036 day⁻¹, 0.0033 day⁻¹ and 0.0021 day⁻¹ for leaves, sheaths and stems, respectively. For belowground parts, the decay rate varied considerably from 0.0018 day⁻¹ to 0.0079 day⁻¹, according to differences in the initial chemical compositions of rhizomes. After 359 days of decay, new rhizomes lost 94% of their original dry mass, compared with a loss of 48–84% for the other rhizomes. There was a significant positive relationship between litter quality and decay rate for horizontal rhizomes. For the new rhizomes, which had an internal nitrogen content of 24.2 mg N g⁻¹ dry mass, the mass loss was 40% higher than that of soft rhizomes, which had an internal N content of 9.8 mg N g⁻¹ dry mass. Over the period of 359 days, the nitrogen concentration in all rhizome types decreased to levels lower than initial values, but the phosphorus concentration remained constant after an initial leaching loss. Most nitrogen and phosphorus were lost during the first 45 days of decay. Changes in carbon to nitrogen (C:N) and carbon to phosphorus (C:P) ratios basically followed inversed trends of the nitrogen and phosphorus concentrations.