Sphingosine kinase 1 mediation of expression of the anaphylatoxin receptor C5L2 dampens the inflammatory response to endotoxin

The complement anaphylatoxin C5a has a pathogenetic role in endotoxin-induced lung inflammatory injury by regulating phagocytic cell migration and activation. Endotoxin and C5a activate the enzyme sphingosine kinase (Sphk) 1 to generate the signaling lipid sphingosine-1-phosphate (S1P), a critical regulator of phagocyte function. We assessed the function of Sphk1 and S1P in experimental lung inflammatory injury and determined their roles in anaphylatoxin receptor signaling and on the expression of the two C5a receptors, C5aR (CD88) and C5L2, on phagocytes. We report that Sphk1 gene deficient (Sphk1(-/-)) mice had augmented lung inflammatory response to endotoxin compared to wild type mice. Sphk1 was required for C5a-mediated reduction in cytokine and chemokine production by macrophages. Moreover, neutrophils from Sphk1(-/-) mice failed to upregulate the anaphylatoxin receptor C5L2 in response to LPS. Exogenous S1P restored C5L2 cell surface expression of Sphk1(-/-) mouse neutrophils to wild type levels but had no effect on cell surface expression of the other anaphylatoxin receptor, CD88. These results provide the first genetic evidence of the crucial role of Sphk1 in regulating the balance between expression of CD88 and C5L2 in phagocytes. S1P-mediated up-regulation of C5L2 is a novel therapeutic target for mitigating endotoxin-induced lung inflammatory injury.     

Evaluation of the decay resistance properties of Cerbera odollam extracts and their influence on properties of particleboard

Metallic-based wood preservatives currently face some restrictions over disposal and environmental issues; one possibility to develop new more benign systems is to study extractives in naturally durable woody plants. This study investigated the resistance of extracts from the leaf, fruit, wood, bark, seed and flower of Cerbera odollam to deterioration from fungus and termites. Antifungal assays with n-hexane, ethyl acetate, ethanol and methanol extracts were evaluated using paper discs. Termite mortality was evaluated with the methanol extract against Coptotermes gestroi. Physical and protective properties of particleboard impregnated with C. odollam extracts, including thickness swelling, internal bond strength, formaldehyde release, termite-decay and soil burial decay were investigated. Methanol wood extracts from C. odollam showed the highest activities against Trametes versicolor, Pycnoporus sanguineus, and Schizophyllum commune in the paper disc antifungal assay. Methanol flower extracts exhibited high performance in termite mortality, termite-decay and soil burial decay. Thickness swelling, internal bond strength and the formaldehyde emission of particleboard specimens treated with methanol extracts of C. odollam were up to the EN Standards.     

Irradiation does not affect field dispersal ability in the West Indian sweetpotato weevil, Euscepes postfasciatus

The effect of irradiation on the dispersal ability of males and females of the flightless West Indian sweetpotato weevil, Euscepes postfasciatus (Fairmaire) (Coleoptera: Curculionidae), a major sweet potato pest, was examined in the field using mark–release–recapture techniques. To evaluate the dispersal ability of the weevil, we released 7 619 weevils in two replicates (July and August 2007). Each replicate lasted 5 days from release to sampling and consisted of one weevil release and two weevil samplings. Thirty-two traps were placed in lines corresponding to eight compass directions and in four distance classes (8, 12, 16, and 20 m) in each replicate. We captured 709 (9.3%) weevils in the two replicates. Weevils dispersed at least 20 m from the release point in 2 days, regardless of sex or irradiation. Dispersal was strongly affected by wind direction, and in both replicates most weevils were recaptured in upwind directions. The mean dispersal distance for non-irradiated weevils was about 11 m per 2 days. Although there were some differences between sexes in recapture rate and dispersal distance, there was no consistent difference between irradiated and non-irradiated weevils in dispersal distance. We conclude that irradiation does not affect the dispersal ability of flightless E. postfasciatus in the field.     

Cost and probability of flowering at the shoot level in relation to variability in shoot size within the crown of Vaccinium hirtum (Ericaceae)

Size-related variation in the cost and probability of flowering among shoots within a crown of Vaccinium hirtum was investigated to clarify patterns and regulation of flowering at the shoot-module level, below the level of the individual. The apices of previous-year shoots differentiated into current-year shoots vegetatively (vegetative branches) or became reproductive by developing inflorescences (reproductive branches). Length growth and fate of current-year shoots were determined, and the future potential for reproduction was estimated using a matrix model of shoot dynamics. Reproductive branches had fewer current-year shoots and shorter total shoot lengths and thus had a reduced potential for reproduction compared with vegetative branches, indicating the cost of flowering at the shoot level. This cost of flowering was higher in longer shoots. The probability of the initiation of flowering in a shoot increased with increasing shoot length in shorter shoots, reached a maximum in medium-sized shoots, and decreased in longer shoots. The size-related changes in the probability of flowering at the shoot level can be largely explained by the size-dependent changes in shoot-level resource availability and cost of flowering.     

Reactive oxygen species generation in gingival fibroblasts of Down syndrome patients detected by electron spin resonance spectroscopy

Oral manifestations of Down syndrome include high susceptibility to gingival inflammation with early onset and rapidly progressive periodontitis. The influence of reactive oxygen species (ROS) on periodontitis of Down syndrome is unclear. The aim of this study was to characterize ROS formation in Down syndrome-gingival fibroblasts (DS-GF) using electron spin resonance (ESR) spin trapping with 5,5-dimetyl-1-pyrolline-N-oxide (DMPO), and to determine whether ROS generation plays a role in the pathogenesis of periodontitis in Down syndrome patients. We observed formation of the DMPO-OH spin adduct, indicating HO* generation from cultured DS-GF and non-DS-GF. The increased HO* generation in cultured DS-GF was strongly decreased in the presence of the H2O2 scavenger, catalase, or the iron chelator, desferal. This may due to the enzymatic ability of over-expressed CuZn-superoxide dismutase in Down syndrome to catalyze the formation of H2O2 from O2*-, thereby increasing the availability of substrate H2O2 for the iron-dependent generation of HO* via the Fenton reaction, suggesting that HO* generated from DS-GF may be involved in progressive periodontitis of Down syndrome.