Lipopolysaccharide (LPS), the major glycolipid component of gram-negative bacterial outer membranes, is a potent endotoxin responsible for pathophysiological symptoms characteristic of infection. The observation that the majority of LPS is found in association with plasma lipoproteins has prompted the suggestion that sequestering of LPS by lipid particles may form an integral part of a humoral detoxification mechanism. Previous studies on the biological properties of isolated lipoproteins used differential ultracentrifugation to separate the major subclasses. To preserve the integrity of the lipoproteins, we have analyzed the LPS distribution, specificity, binding capacity, and kinetics of binding to lipoproteins in human whole blood or plasma by using high-performance gel permeation chromatography and fluorescent LPS of three different chemotypes. The average distribution of O111:B4, J5, or Re595 LPS in whole blood from 10 human volunteers was 60% (؎8%) high-density lipoprotein (HDL), 25% (؎7%) low-density lipoprotein, and 12% (؎5%) very low density lipoprotein. The saturation capacity of lipoproteins for all three LPS chemotypes was in excess of 200 g/ml. Kinetic analysis however, revealed a strict chemotype dependence. The binding of Re595 or J5 LPS was essentially complete within 10 min, and subsequent redistribution among the lipoprotein subclasses occurred to attain similar distributions as O111:B4 LPS at 40 min. We conclude that under simulated physiological conditions, the binding of LPS to lipoproteins is highly specific, HDL has the highest binding capacity for LPS, the saturation capacity of lipoproteins for endotoxin far exceeds the LPS concentrations measured in clinical situations, and the kinetics of LPS association with lipoproteins display chemotype-dependent differences.The lipopolysaccharide (LPS) components of gram-negative bacterial outer membranes are potent endotoxins responsible for hemodynamic, hematological, and metabolic changes observed during severe infection. Activation of responsive cells of the host immune system by low concentrations of LPS results in the production of high levels of endogenous mediators of inflammation such as tumor necrosis factor alpha (TNF-␣) and interleukin-1␤ (IL-1␤), IL-6, and IL-8, which are capable of sustaining the inflammatory state. Among the observed metabolic changes in patients are profound disturbances in plasma lipid profiles (1,5,14) that may also be induced in experimental animals by LPS challenge (12). Lipid metabolism appears to be extensively regulated during the host response to infection; however, increased cytokine levels do not solely appear to be responsible for the characteristic alterations in plasma lipid profiles. It has recently been suggested that disturbances in lipid metabolism may, in fact, form part of the host defense because the immune response is tightly linked to the metabolic response (15). LPS binding protein (LBP) is an acute-phase protein (29) that plays a central role in the attenuation of the cellular response to end...

The present survey provides a reasonable picture of the demographic features and clinical manifestations of Indian patients with IBD, their risk factors, course of disease, and the treatment given to them.

To explore the natural microbial community of any ecosystems by high-resolution molecular approaches including next generation sequencing, it is extremely important to develop a sensitive and reproducible DNA extraction method that facilitate isolation of microbial DNA of sufficient purity and quantity from culturable and uncultured microbial species living in that environment. Proper lysis of heterogeneous community microbial cells without damaging their genomes is a major challenge. In this study, we have developed an improved method for extraction of community DNA from different environmental and human origin samples. We introduced a combination of physical, chemical and mechanical lysis methods for proper lysis of microbial inhabitants. The community microbial DNA was precipitated by using salt and organic solvent. Both the quality and quantity of isolated DNA was compared with the existing methodologies and the supremacy of our method was confirmed. Maximum recovery of genomic DNA in the absence of substantial amount of impurities made the method convenient for nucleic acid extraction. The nucleic acids obtained using this method are suitable for different downstream applications. This improved method has been named as the THSTI method to depict the Institute where the method was developed.

Lipopolysaccharide (LPS), the major outer membrane component of gram-negative bacteria, is a potent endotoxin that triggers cytokine-mediated systemic inflammatory responses in the host. Plasma lipoproteins are capable of LPS sequestration, thereby attenuating the host response to infection, but ensuing dyslipidemia severely compromises this host defense mechanism. We have recently reported that Escherichia coli J5 and Re595 LPS chemotypes that contain relatively short O-antigen polysaccharide side chains are efficiently redistributed from high-density lipoproteins (HDL) to other lipoprotein subclasses in normal human whole blood (ex vivo). In this study, we examined the role of the acute-phase proteins LPS-binding protein (LBP) and phospholipid transfer protein (PLTP) in this process. By the use of isolated HDL containing fluorescent J5 LPS, the redistribution of endotoxin among the major lipoprotein subclasses in a model system was determined by gel permeation chromatography. The kinetics of LPS and lipid particle interactions were determined by using Biacore analysis. LBP and PLTP were found to transfer LPS from HDL predominantly to low-density lipoproteins (LDL), in a time-and dose-dependent manner, to induce remodeling of HDL into two subpopulations as a consequence of the LPS transfer and to enhance the steady-state association of LDL with HDL in a dose-dependent fashion. The presence of LPS on HDL further enhanced LBP-dependent interactions of LDL with HDL and increased the stability of the HDL-LDL complexes. We postulate that HDL remodeling induced by LBP-and PLTP-mediated LPS transfer may contribute to the plasma lipoprotein dyslipidemia characteristic of the acute-phase response to infection.Lipopolysaccharide (LPS), a major outer membrane constituent of gram-negative bacteria, is a potent endotoxin that, through the activation of cellular immunity, induces a cytokine-mediated systemic inflammatory response in the host (5). Lipopolysaccharide-binding protein (LBP) is an acute-phase protein responsible for the binding and transport of LPS in circulation (15). The acute-phase (AP) response is characterized by increased plasma LBP levels, from 5 to 15 mg/liter to 50 to 100 mg/liter (14), and a 5-to 20-fold decrease in plasma lipoprotein cholesterol levels (10). Delivery of LPS by LBP to macrophage receptors initiates signal transduction pathways (20) that lead to the increased release of proinflammatory cytokines (23). However, the delivery of LPS to high-density lipoprotein (HDL) (3) by LBP, which has been found to reside exclusively on HDL (22), results in the attenuation of the immune response to infection. LBP has indeed been detected in association with low-density lipoprotein (LDL) only under conditions of dyslipidemia, such as that observed in septic patients (1). The observation that patients with high circulating LBP levels have a better prognosis than those with lower levels (15) suggests that LBP plays an essential role in LPS transfer in addition to phospholipid transport (24). Phospholipid tr...

Background/Aims There has been major progress in our understanding of the irritable bowel syndrome (IBS), and novel treatment classes have emerged. The Rome IV guidelines were published in 2016 and together with the growing body of Asian data on IBS, we felt it is timely to update the Asian IBS Consensus. Methods Key opinion leaders from Asian countries were organized into 4 teams to review 4 themes: symptoms and epidemiology, pathophysiology, diagnosis and investigations, and lifestyle modifications and treatments. The consensus development process was carried out by using a modified Delphi method. Results Thirty-seven statements were developed. Asian data substantiate the current global viewpoint that IBS is a disorder of gut-brain interaction. Socio-cultural and environmental factors in Asia appear to influence the greater overlap between IBS and upper gastrointestinal symptoms. New classes of treatments comprising low fermentable oligo-, di-, monosacharides, and polyols diet, probiotics, non-absorbable antibiotics, and secretagogues have good evidence base for their efficacy. Conclusions Our consensus is that all patients with functional gastrointestinal disorders should be evaluated comprehensively with a view to holistic management. Physicians should be encouraged to take a positive attitude to the treatment outcomes for IBS patients.