TLR5 as an anti-inflammatory target and modifier gene in cystic fibrosis

New treatments are needed to improve the health of people with cystic fibrosis (CF). Reducing lung-damaging inflammation is likely to be beneficial, but specific anti-inflammatory targets have not been identified. By combining cellular immunology with a population-based genetic modifier study, we examined TLR5 as an anti-inflammatory target and modifier gene in CF. Using two pairs of human CF and control airway epithelial cells, we demonstrated that the TLR5-flagellin interaction is a major mediator of inflammation following exposure to Pseudomonas aeruginosa. To validate TLR5 as an anti-inflammatory target, we analyzed the disease modifying effects of the TLR5 c.1174C>T single nucleotide polymorphism (rs5744168) in a large cohort of CF patients (n = 2219). rs5744168 encodes a premature stop codon and the T allele is associated with a 45.5-76.3% reduction in flagellin responsiveness (p < 0.0001). To test the hypothesis that reduced TLR5 responsiveness would be associated with improved health in CF patients, we examined the relationship between rs5744168 and two clinical phenotypes: lung function and body weight. Adults with CF carrying the TLR5 premature stop codon (CT or TT genotype) had a higher body mass index than did CF patients homozygous for the fully functional allele (CC genotype) (p = 0.044); however, similar improvements in lung function associated with the T allele were not statistically significant. Although follow-up studies are needed to confirm the impact of TLR5 on nutritional status, this translational research provides evidence that genetic variation in TLR5 resulting in reduced flagellin responsiveness is associated with improved health indicators in adults with CF.     

添加玉米和水稻秸秆对淹水土壤pH、二氧化碳及交换态铵的影响

通过温室土壤培养试验,研究了不同添加量玉米和水稻秸秆对淹水土壤pH、CO₂及交换态铵的影响.结果表明：在接近中性的土壤中加入秸秆可使土壤pH值降低,4 g·kg^-1玉米和水稻秸秆处理的土壤pH值均与对照差异显著（P＜0.05）,而1 g·kg^-1玉米和水稻秸秆处理与对照差异不显著（P＞0.05）.土壤溶液中的CO₂含量随秸秆添加量的增加而增大,1 g·kg^-1玉米和水稻秸秆处理的土壤溶液CO₂含量最大值分别为35.9％和31.9％（v/v）,与对照（25.8％）差异达显著水平（P＜0.05）,但两者间差异不显著（P＞0.05）;4 g·kg^-1玉米和水稻秸秆处理的土壤溶液CO₂含量最大值分别为54.2％和41.8％（v/v）,与对照差异极显著（P＜0.01）,两者间差异也达显著水平（P＜0.05）.在不施氮肥的情况下,添加秸秆可降低土壤铵态氮浓度,且铵态氮浓度随秸秆添加量的增加而降低,不同添加量处理间差异显著（P＜0.05）;在施入氮肥的情况下,1 g·kg^-1玉米和水稻秸秆处理提高了土壤铵态氮浓度,而4 g·kg^-1玉米和水稻秸秆处理降低了土壤铵态氮浓度.无论是否施入氮肥,玉米和水稻秸秆处理的土壤铵态氮浓度差异不显著（P＞0.05）.     

Molecular evolution of chloroplast DNA sequences

Comparative data on the evolution of chloroplast genes are reviewed. The chloroplast genome has maintained a similar structural organization over most plant taxa so far examined. Comparisons of nucleotide sequence divergence among chloroplast genes reveals marked similarity across the plant kingdom and beyond to the cyanobacteria (blue-green algae). Estimates of rates of nucleotide substitution indicate a synonymous rate of 1.1 x 10(-9) substitutions per site per year. Noncoding regions also appear to be constrained in their evolution, although addition/deletion events are common. There have also been evolutionary changes in the distribution of introns in chloroplast encoded genes. Relative to mammalian mitochondrial DNA, the chloroplast genome evolves at a conservative rate.      

Late Holocene extinction of Puerto Rican native land mammals

West Indian land mammals have suffered the most severe extinctions of any Holocene mammal faunas. However, 'last-occurrence' dates based on radiometric or robust stratigraphic data remain unavailable for most West Indian species, making it impossible to identify factors responsible for these extinctions. Here, we present new radiometric dates from archaeological and palaeontological sites on Puerto Rico, the only Greater Antillean island to have lost all native land mammals. Although it has been suggested that these species died out earlier than other West Indian mammals, we demonstrate that Puerto Rican mammal last-occurrence dates are in close agreement with those from other Antillean islands, as several species in fact persisted for millennia following Amerindian arrival. Echimyid rodents and nesophontid 'island-shrews' were still present on Puerto Rico approximately 1000 years BP, and probably became extinct following European arrival. The large (13kg) heptaxodontid rodent Elasmodontomys obliquus also appears to have survived for over 2000 years after Amerindian colonization, suggesting that at least some large West Indian mammals became extinct in protracted pre-European 'sitzkrieg'-style events rather than 'blitzkrieg'-style overkill.     

Invasive non‐native species likely to threaten biodiversity and ecosystems in the Antarctic Peninsula region

The Antarctic is considered to be a pristine environment relative to other regions of the Earth, but it is increasingly vulnerable to invasions by marine, freshwater and terrestrial non‐native species. The Antarctic Peninsula region (APR), which encompasses the Antarctic Peninsula, South Shetland Islands and South Orkney Islands, is by far the most invaded part of the Antarctica continent. The risk of introduction of invasive non‐native species to the APR is likely to increase with predicted increases in the intensity, diversity and distribution of human activities. Parties that are signatories to the Antarctic Treaty have called for regional assessments of non‐native species risk. In response, taxonomic and Antarctic experts undertook a horizon scanning exercise using expert opinion and consensus approaches to identify the species that are likely to present the highest risk to biodiversity and ecosystems within the APR over the next 10 years. One hundred and three species, currently absent in the APR, were identified as relevant for review, with 13 species identified as presenting a high risk of invading the APR. Marine invertebrates dominated the list of highest risk species, with flowering plants and terrestrial invertebrates also represented; however, vertebrate species were thought unlikely to establish in the APR within the 10 year timeframe. We recommend (a) the further development and application of biosecurity measures by all stakeholders active in the APR, including surveillance for species such as those identified during this horizon scanning exercise, and (b) use of this methodology across the other regions of Antarctica. Without the application of appropriate biosecurity measures, rates of introductions and invasions within the APR are likely to increase, resulting in negative consequences for the biodiversity of the whole continent, as introduced species establish and spread further due to climate change and increasing human activity.     

<i>Trichoderma</i> spp. fostering growth on <i>Capsicum chinense</i> Jacq. seedlings and antagonistic against <i>Meloidogyne incognita</i>

Fourteen native strains of Trichoderma spp. from wildand agricultural pathosystems in the state of Yucatan, Mexico, with growth-promoting ability of Capsicum chinense Jacq. seedlings were evaluated and antagonistic effect of their filtrate against second-stage juveniles (J2) of Meloidogyne incognita. The strains Th05-02 and Th27-08 showed the best significant effects on plant hight variable increments 55.57 and 47.62%, theTh07-04 with 29.48% more root length, theTh02-01 and Th07-04 isolates increased from 48.71 to 84.61% in volume radical and 53.40% of total dry biomass. Statistical analysis (p≤0.001) of Th43 and Th43-13-14 filtrates caused 100% mortality at 24 and 48h. In the test of reversibility to 24 h after replacing the filtrates Th43-13, Th43-14, TH09-06 and TH20-07 by sterile distilled water, the J2 did not recover their viability, so they were considered as the best potential strains of Trichoderma spp. with antagonistic capacity in J2 of M.incognita.     

A morphometric analysis of the corpus luteum of the cow during the estrous cycle and early pregnancy

Corpora lutea were collected from cows on Days 6, 8, 10, 12, 14, 16, 18 and 19 of the estrous cycle and early pregnancy (n=2/d) and were examined by light microscopy. Mean lutein cell diameter was significantly (P<0.05) greater in pregnant than in cyclic cows on Days 6, 8, 10, 12, 16, 18 and 19 (cyclic versus pregnant: Day 6: 13.9 +/- 0.22 vs 14.9 +/- 0.24; Day 8: 13.8 +/- 0.20 vs 15.4 +/- 0.2; Day 10: 14.8 +/- 0.24 vs 17.4 +/- 0.24; Day 12: 13.2 +/-0.25 vs 17.9 +/- 0.31; Day 16: 13.9 +/- 0.28 vs 16.5 +/- 0.31; Day 18: 13.0 +/- 0.22 vs 16.5 +/- 09.36, and Day 19: 15.0 +/- 0.23 vs 17.6 +/- 0.33 mum, respectively). The distribution of cell sizes was leptokurtotic throughout the estrous cycle and the first 10 d of pregnancy, but tended towards bimodality after Day 14 of pregnancy. The proportion of lutein cell cytoplasm occupied by vacuoles was lower in pregnant than in cyclic cows from the 12th day post estrus, but there was a marked (P<0.05) increase in vacuolation of cells from cows undergoing luteolysis. Stainable intercellular collagen was also less abundant in pregnant than cyclic cows from the 12th day post estrus. The higher rate of progesterone secretion of pregnant, compared with cyclic cows may be attributed to the greater numbers and greater contribution to luteal mass of large lutein cells in the corpus luteum of pregnancy.     

An immune paradox: How can the same chemokine axis regulate both immune tolerance and activation?

Chemokines (chemotactic cytokines) drive and direct leukocyte traffic. New evidence suggests that the unusual CCR6/CCL20 chemokine receptor/ligand axis provides key homing signals for recently identified cells of the adaptive immune system, recruiting both pro-inflammatory and suppressive T cell subsets. Thus CCR6 and CCL20 have been recently implicated in various human pathologies, particularly in autoimmune disease. These studies have revealed that targeting CCR6/CCL20 can enhance or inhibit autoimmune disease depending on the cellular basis of pathogenesis and the cell subtype most affected through different CCR6/CCL20 manipulations. Here, we discuss the significance of this chemokine receptor/ligand axis in immune and inflammatory functions, consider the potential for targeting CCR6/CCL20 in human autoimmunity and propose that the shared evolutionary origins of pro-inflammatory and regulatory T cells may contribute to the reason why both immune activation and regulation might be controlled through the same chemokine pathway.     

Russia–UK Collaboration in Paleontology: Past,Present, and Future

There is a long history of collaboration between Russia and the United Kingdom in paleontology. This began, arguably, in 1821, with the seminal work by William Fox-Strangways, who produced a geological map of the area around St Petersburg. Most famously, Roderick Murchison carried out extensive surveying and observations throughout European Russia in 1840 and 1841, and published a major monograph on geology and paleontology of European Russia in 1845. Since then, and continuing today, there have been many fruitful collaborations on Precambrian life, Paleozoic marine organisms, terrestrialization of plants and vertebrates, the Permian–Triassic mass extinction, fossil mammals, human evolution, and conservation paleobiology.