Pathogenesis and Potential Strategies for Prevention and Treatment of Septic Shock: An Update

Septic shock is mediated by complex interactions of cells, cytokines, and humoral pathways. Clinical therapeutic strategies aimed at inhibiting selected pathways have been efficacious in subsets of patients. Experimental studies focusing on the activities of single cytokines have contributed to the understanding of the complex pathophysiology of septic shock. More precise delineation of the roles of each mechanism contributing to pathogenesis will permit the identification of subsets of patients who might benefit from particular therapeutic strategies and will guide the development of additional approaches to prevention and treatmen

Antibodies to Lipopolysaccharides after Immunization of Humans with the Rough Mutant Escherichia coli J5

To investigate whether immunization with Escherichia coli J5 boiled cells induces antibodies directed at deep core structures, antibodies against JS lipopolysaccharide (LPS), Re LPSt and Iipid A were measured in the serum of 70 volunteers before and 2 weeks after immunization. To improve the sensitivity and the specificity ofELISAt complexes of core LPS with high-density lipoproteins were used instead of free core LPS as antigens. A median three-fold increase in antibodies directed against J5 LPS was observed, but no significant increase in the antibodies against Re LPS or lipid A was found. Since JS antiserum did not react with several smooth LPS or with Re LPS and lipid At cross-reactivity could not be demonstrated. Thus, immunization of volunteers with E. coli J5 produced a modest specific antibody response against J5 LPS. The mechanism of protection previously observed with J5 antiserum remains unclea

Antibodies to Core Lipopolysaccharide Determinants: Absence of Cross-reactivity with Heterologous Lipopolysaccharides

Using monoclonal antibodies directed against defined epitopes of endotoxin core, this study demonstrated that the presentation of lipopolysaccharide (LPS) to antibodies is critical for measuring the specific binding of antibodies to LPS structures. False cross-reactive reactions apparently were observed when free core LPS or lipid A were used as antigens in ELISA, whereas coating with complexes of high-density lipoproteins with core LPS increased both the sensitivity and the specificity of the test compared with coating with free core LPS, so that nonspecific binding of antibodies was largely avoided. Using this technique, it was not possible to find broadly cross-reactive core LPS antibodies after immunization of rabbits and humans with rough mutants of gram-negative bacteria. These observations underscore the need for careful evaluation of the potential for cross-reactivity of antisera and of monoclonal antibodies directed against endotoxin cor

Insights on Water Interaction at the Interface of Nitrogen Functionalized Hydrothermal Carbons

Hydrothermal carbon (HTC) derived from biomass is a class of cost-efficient, eco-friendly functional carbon materials with various potential applications. In this work, solid-state nuclear magnetic resonance (NMR), longitudinal (T1) relaxation time and diffusion NMR were employed to investigate the structure and water dynamics for HTC and nitrogen-functionalized hydrothermal carbon (N-HTC) samples ((N)-HTC). Results showed that the presence of N-functional groups influences the water interaction with (N)-HTC more strongly than surface area, pore size distribution or oxygenated functional groups. Furthermore, the degree of water interaction can be tuned by adjusting the synthesis temperature and the precursor ratio. Water motion was more strongly inhibited in N-HTC than in N-free HTC, thereby suggesting the existence of a differently structured hydration shell around N-HTC particles. In addition, the diffusion data of water in the N-HTC material shows two components that do not exchange on the time scale of the experiment (tens of milliseconds), indicating a significant fraction of slow mobile water that exists inside the structure of N-HTC. 1H–2H isotope exchange and cross-polarization NMR results show this internal water only in a near-surface layer of the N-HTC particles. Based on these findings, a model for water interaction with (N)-HTC particles is proposed

Pathogenesis and potential strategies for prevention and treatment of septic shock: an update

Septic shock is mediated by complex interactions of cells, cytokines, and humoral pathways. Clinical therapeutic strategies aimed at inhibiting selected pathways have been efficacious in subsets of patients. Experimental studies focusing on the activities of single cytokines have contributed to the understanding of the complex pathophysiology of septic shock. More precise delineation of the roles of each mechanism contributing to pathogenesis will permit the identification of subsets of patients who might benefit from particular therapeutic strategies and will guide the development of additional approaches to prevention and treatment

Using MODIS derived <i>f</i>PAR with ground based flux tower measurements to derive the light use efficiency for two Canadian peatlands

International audienceWe used satellite remote sensing data; fraction of photosynthetically active radiation absorbed by vegetation (fPAR) from the Moderate Resolution Imaging Spectroradiometer (MODIS) in combination with tower eddy covariance and meteorological measurements to characterise the light use efficiency parameter (?) variability and the maximum ? (?max) for two contrasting Canadian peatlands. Eight-day MODIS fPAR data were acquired for the Mer Bleue (2000 to 2003) and Western Peatland (2004). Flux tower eddy covariance and meteorological measurements were integrated to the same eight-day time stamps as the MODIS fPAR data. A light use efficiency model: GPP=? * APAR (where GPP is Gross Primary Productivity and APAR is absorbed photosynthetically active radiation) was used to calculated ?. The ?max value for each year (2000 to 2003) at the Mer Bleue bog ranged from 0.58 g C MJ?1 to 0.78 g C MJ?1 and was 0.91 g C MJ?1 in 2004, for the Western Peatland. The average growing season ? for the Mer Bleue bog for the four year period was 0.35 g C MJ?1 and for the Western Peatland in 2004 was 0.57 g C MJ?1. The average snow free period ? for the Mer Bleue bog over the four year period was 0.27 g C MJ?1 and for the Western Peatland in 2004 was 0.39 g C MJ?1. Using the light use efficiency method we calculated the ?max and the annual variability in ? for two Canadian peatlands. We determined that temperature was a growth-limiting factor at both sites Vapour Pressure Deficit (VPD) however was not. MODIS fPAR is a useful tool for the characterization of ? at flux tower sites

Antibodies to lipopolysaccharides after immunization of humans with the rough mutant Escherichia coli J5

To investigate whether immunization with Escherichia coli J5 boiled cells induces antibodies directed at deep core structures, antibodies against J5 lipopolysaccharide (LPS), Re LPS, and lipid A were measured in the serum of 70 volunteers before and 2 weeks after immunization. To improve the sensitivity and the specificity of ELISA, complexes of core LPS with high-density lipoproteins were used instead of free core LPS as antigens. A median three-fold increase in antibodies directed against J5 LPS was observed, but no significant increase in the antibodies against Re LPS or lipid A was found. Since J5 antiserum did not react with several smooth LPS or with Re LPS and lipid A, cross-reactivity could not be demonstrated. Thus, immunization of volunteers with E. coli J5 produced a modest specific antibody response against J5 LPS. The mechanism of protection previously observed with J5 antiserum remains unclear

Antibodies to core lipopolysaccharide determinants: absence of cross-reactivity with heterologous lipopolysaccharides

Using monoclonal antibodies directed against defined epitopes of endotoxin core, this study demonstrated that the presentation of lipopolysaccharide (LPS) to antibodies is critical for measuring the specific binding of antibodies to LPS structures. False cross-reactive reactions apparently were observed when free core LPS or lipid A were used as antigens in ELISA, whereas coating with complexes of high-density lipoproteins with core LPS increased both the sensitivity and the specificity of the test compared with coating with free core LPS, so that nonspecific binding of antibodies was largely avoided. Using this technique, it was not possible to find broadly cross-reactive core LPS antibodies after immunization of rabbits and humans with rough mutants of gram-negative bacteria. These observations underscore the need for careful evaluation of the potential for cross-reactivity of antisera and of monoclonal antibodies directed against endotoxin core