Neutrophil Extracellular Traps Induce Organ Damage during Experimental and Clinical Sepsis

Organ dysfunction is a major concern in sepsis pathophysiology and contributes to its high mortality rate. Neutrophil extracellular traps (NETs) have been implicated in endothelial damage and take part in the pathogenesis of organ dysfunction in several conditions. NETs also have an important role in counteracting invading microorganisms during infection. The aim of this study was to evaluate systemic NETs formation, their participation in host bacterial clearance and their contribution to organ dysfunction in sepsis. C57Bl/6 mice were subjected to endotoxic shock or a polymicrobial sepsis model induced by cecal ligation and puncture (CLP). The involvement of cf-DNA/NETs in the physiopathology of sepsis was evaluated through NETs degradation by rhDNase. This treatment was also associated with a broad-spectrum antibiotic treatment (ertapenem) in mice after CLP. CLP or endotoxin administration induced a significant increase in the serum concentrations of NETs. The increase in CLP-induced NETs was sustained over a period of 3 to 24 h after surgery in mice and was not inhibited by the antibiotic treatment. Systemic rhDNase treatment reduced serum NETs and increased the bacterial load in non-antibiotic-treated septic mice. rhDNase plus antibiotics attenuated sepsis-induced organ damage and improved the survival rate. The correlation between the presence of NETs in peripheral blood and organ dysfunction was evaluated in 31 septic patients. Higher cf-DNA concentrations were detected in septic patients in comparison with healthy controls, and levels were correlated with sepsis severity and organ dysfunction. In conclusion, cf-DNA/NETs are formed during sepsis and are associated with sepsis severity. In the experimental setting, the degradation of NETs by rhDNase attenuates organ damage only when combined with antibiotics, confirming that NETs take part in sepsis pathogenesis. Altogether, our results suggest that NETs are important for host bacterial control and are relevant actors in the pathogenesis of sepsis.     

Land-Use Change and Biogeochemical Controls of Methane Fluxes in Soils of Eastern Amazonia

Tropical soils account for 10%–20% of the 15–35 Tg of atmospheric methane (CH₄) consumed annually by soils, although tropical deforestation could be changing the soil sink. The objectives of this study were (a) to quantify differences in soil CH₄ fluxes among primary forest, secondary forest, active pasture, and degraded pasture in eastern Amazonia; and (b) to investigate controlling mechanisms of CH₄ fluxes, including N availability, gas-phase transport, and soil respiration. At one ranch, Fazenda Vitória, annual uptake estimates (kg CH₄ha⁻¹ y⁻¹) based on monthly measurements were: primary forest, 2.1; secondary forest, 1.0; active pasture, 1.3; degraded pasture, 3.1. The lower annual uptake in the active pasture compared with the primary forest was due to CH₄ production during the wet season in the pasture soils, which is consistent with findings from other studies. In contrast, the degraded pasture was never a CH₄ source. Expressing uptake as a negative flux and emission as a positive flux, CH₄ fluxes were positively correlated with CO₂ fluxes, indicating that root and microbial respiration in the productive pastures, and to a lesser extent in the primary forest, contributed to the formation of anaerobic microsites where CH₄ was produced, whereas this productivity was absent in the degraded pasture. In all land uses, uptake rates of atmospheric CH₄ were greater in the dry season than in the wet season, indicating the importance of soil water content and gas transport on CH₄ fluxes. These clay soils had low annual uptake rates relative to reported rates on sandy soils, which also is consistent with gas transport within the soil being a limiting factor. Nitrogen availability indices did not correlate with CH₄ fluxes, indicating that inhibition of CH₄ oxidation was not an important mechanism explaining differences among land uses. At another ranch, Fazenda Agua Parada, no significant effect of pasture age was observed along a chronosequence of pasture ages. We conclude that land-use change can either increase or decrease the soil sink of CH₄, depending on the duration of wet and dry seasons, the effects of seasonal precipitation on gas-phase transport, and the phenology and relative productivity of the vegetation in each land use.     

Anopheles albitarsis embryogenesis: morphological identification of major events

Anopheles albitarsis embryogenesis was analyzed through confocal microscopy of clarified eggs. Using Drosophila melanogaster as reference system, the major morphogenetic events (blastoderm, gastrulation, germ band extension, germ band retraction, dorsal closure) were identified. The kinetics of early events is proportionally similar in both systems, but late movements (from germ band retraction on) progress slower in An. albitarsis. Major differences in An. albitarsis related to D. melanogaster were: (1) pole cells do not protrude from the blastoderm; (2) the mosquito embryo undergoes a 180 degrees rotation movement, along its longitudinal axis; (3) the head remains individualized throughout embryogenesis; (4) extraembryonary membranes surround the whole embryo. A novel kind of malaria control is under development and is based on the use of genetically modified mosquitoes. Phenotypic analysis of the embryonic development of mutants will be imposed as part of the evaluation of effectiveness and risk of employment of this strategy in the field. In order to accomplish this, knowledge of the wild type embryo is a prerequisite. Morphological studies will also serve as basis for subsequent development biology approaches.     

<Emphasis Type="Italic">Crassostrea gigas</Emphasis> in natural oyster banks in southern Brazil

We report on the invasion of Brazil by the Pacific oyster Crassostrea gigas, and discuss the likely routes of invasion. Because this phenotypically diverse oyster sometimes resembles the native species C. brasiliana and C. rhizophorae, its invasion went unnoticed until it was detected through the analysis of DNA sequences for ribosomal 16S and the ribosomal second internal transcribed spacer. C. gigas was found amongst the native species in oyster banks up to 100 km south of oyster farms in South Brazil. Under most circumstances, water temperatures in the coastal southerly Brazil current would be too high to allow for the establishment of stable populations of C. gigas, but the production of spat in oyster farm laboratories has probably selected for resistance to warmer temperatures, which would promote invasion by C. gigas.     

Use of resin‐bonded extracoronal attachments with removable partial denture: case report

doi:10.1111/j.1741‐2358.2009.00298.x
Use of resin‐bonded extracoronal attachments with removable partial denture: case report Introduction: Resin‐bonded extracoronal attachments may be indicated for the abutment teeth of removable partial dentures, especially for anterior teeth when a cingulum rest must be provided. This type of treatment has a series of advantages such as minimal tooth reduction, supragingival margins, favourable stress distribution, and improved aesthetic appearance. Objective: To report a clinical case of oral rehabilitation using a combination of resin‐bonded extracoronal attachments joined by a Dolder bar with a removable partial denture. Case report: A 60‐year‐old male patient with only the canines in the maxillary arch was restored with a combination of resin‐bonded extracoronal attachments joined by a Dolder bar and a removable partial denture. Conclusion: Dentures with resin‐bonded extracoronal attachments can have a number of advantages over traditional clasp‐retained removable partial dentures.     

The species and chromosomal distribution of the centromeric alpha-satellite I sequence from sheep in the tribe Caprini and other Bovidae

The evolution of chromosomes in species in the family Bovidae includes fusion and fission of chromosome arms (giving different numbers of acrocentric and metacentric chromosomes with a relatively conserved total number of arms) and evolution in both DNA sequence and copy number of the pericentromeric alpha-satellite I repetitive DNA sequence. Here, a probe representing the sheep alpha-satellite I sequence was isolated and hybridized to genomic DNA digests and metaphase chromosomes from various Bovidae species. The probe was highly homologous to the centromeric sequence in all species in the tribe Caprini, including sheep (Ovis aries), goat (Capra hircus) and the aoudad or Barbary sheep (Amnotragus lervia), but showed no detectable hybridization to the alpha-satellite I sequence present in the tribe Bovini and at most very weak to species in the tribes Hippotragini, Alcelaphini or Aepycerotini. The sex chromosomes of sheep, goat and aoudad did not contain detectable alpha-satellite I sequence; in sheep, one of the three metacentric autosomal chromosomes does not carry the sequence, while in aoudad, it is essentially absent in three large autosomal pairs as well as the large metacentric chromosome pair. The satellite probes can be used as robust chromosome and karyotype markers of evolution among tribes and increase the resolution of the evolutionary tree at the base of the Artiodactyla.     

Protective Effects of Ferulic Acid on High Glucose-Induced Protein Glycation,Lipid Peroxidation,and Membrane Ion Pump Activity in Human Erythrocytes

Ferulic acid (FA) is the ubiquitous phytochemical phenolic derivative of cinnamic acid. Experimental studies in diabetic models demonstrate that FA possesses multiple mechanisms of action associated with anti-hyperglycemic activity. The mechanism by which FA prevents diabetes-associated vascular damages remains unknown. The aim of study was to investigate the protective effects of FA on protein glycation, lipid peroxidation, membrane ion pump activity, and phosphatidylserine exposure in high glucose-exposed human erythrocytes. Our results demonstrated that FA (10-100 μM) significantly reduced the levels of glycated hemoglobin (HbA1c) whereas 0.1-100 μM concentrations inhibited lipid peroxidation in erythrocytes exposed to 45 mM glucose. This was associated with increased glucose consumption. High glucose treatment also caused a significant reduction in Na⁺/K⁺-ATPase activity in the erythrocyte plasma membrane which could be reversed by FA. Furthermore, we found that FA (0.1-100 μM) prevented high glucose-induced phosphatidylserine exposure. These findings provide insights into a novel mechanism of FA for the prevention of vascular dysfunction associated with diabetes.