A Model Study to Unravel the Complexity of Bio-Oil from Organic Wastes.

Binary and ternary mixtures of cellulose, bovine serum albumin (BSA) and tripalmitin, as biomass reference compounds for carbohydrates, proteins and triglycerides, respectively, were treated under hydrothermal liquefaction (HTL) conditions to describe the main reaction pathways involved in the process of bio-oil production from municipal organic wastes. Several analytical techniques (elemental analysis, GC-MS, atmospheric-pressure photo-ionisation high-resolution Fourier transform ion cyclotron resonance mass spectrometry, and 13 C cross-polarisation magic-angle spinning NMR spectroscopy) were used for the molecular-level characterisation of the resulting aqueous phase, solid residue and bio-oil, in particular. The main reaction pathways led to free fatty acids, fatty acid amides, 2,5-diketopiperazines and Maillard-type compounds as the main components of the bio-oil. The relationship of such compounds to the original components of the biomass was thus determined, which highlights the fate of the heteroatom-containing molecules in particular. Finally, the molecular composition of the bio-oils from our reference compounds was matched with that of the bio-oil from municipal organic waste biomass by comparing their high-resolution Fourier transform ion cyclotron resonance mass spectra, and we obtained a surprisingly high similarity. Hence, the ternary mixture acts as a reliable biomass model and is a powerful tool to clarify the degradation mechanisms that occur in the biomass under HTL treatment, with the ultimate goal to improve the HTL process itself by modulating the input of the organic starting matter and then the upgrading steps to bio-fuels.

Unusual B cell morphology in inflammatory bowel disease.

B lymphocytes express various different types of surface immunoglobulins that are largely unrelated to other hematological lines, although some reports have described a relationship between malignant B cells and other cells such as macrophages. Multiple genes of hematopoietic lineage, including transcription factors, are co-expressed in hematopoietic stem cells and progenitors, a phenomenon referred to as "lineage priming". Changes in the expression levels and timing of transcription factors can induce the lineage conversion of committed cells, which indicates that the regulation of transcription factors might be particularly critical for maintaining hierarchical hematopoietic development. The aim of this study was to evaluate the surface markers of particular IgM-positive and irregularly nucleated cells detected in patients with inflammatory bowel disease (IBD), and to assess their association with diagnosis and inflammatory cell recruitment. Small intestine, colon and rectal biopsy specimens of 96 IBD patients were studied. Immunoglobulin-producing cells (IPCs) were analyzed by means of immunofluorescence using polyclonal rabbit anti-human Ig and goat anti-human IgM. The specimens positive for B cells with irregular nuclei were assessed using monoclonal antibodies specific for CD79, and λ and κ chains in order to confirm their B cell nature. CD15+ cells, an important marker of inflammatory cell recruitment, were also evaluated. Statistical correlations were sought between the histological findings and clinical expression. 34 (35.4%) of the 96 patients (64 with ulcerative colitis and 32 with Crohn's disease) presented a periglandial localization of IPCs with irregular nuclei, which showed surface markers specific for the B cell subset, such as IgM and CD79, but quantitative differences in λ and κ chains. These specimens also contained CD15-positive cells, which are usually absent in healthy controls. The quantitative aspects and localization of the CD15-positive cells correlated with the distribution of the IPCs with irregular nuclei. IPCs with irregular nuclei were significantly more frequent in those patients with Crohn's disease than in those with ulcerative colitis (p<0.001). The finding of a subpopulation of cells that simultaneously showed irregular nuclei and B cell markers, such as functional surface IgM, in patients with IBD suggests that an unusual subgroup of B cells that correlates with CD15 expression and a diagnosis of Crohn's disease may be observed in the inflammatory process.

B lymphocyte intestinal homing in inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease (IBD) is thought to be due to an abnormal interaction between the host immune system and commensal microflora. Within the intestinal immune system, B cells produce physiologically natural antibodies but pathologically atypical anti-neutrophil antibodies (xANCAs) are frequently observed in patients with IBD. The objective is to investigate the localisation of immunoglobulin-producing cells (IPCs) in samples of inflamed intestinal tissue taken from patients with IBD, and their possible relationship with clinical features. METHODS: The IPCs in small intestinal, colonic and rectal biopsy specimens of patients with IBD were analysed by means of immunofluorescence using polyclonal rabbit anti-human Ig and goat anti-human IgM. The B cell phenotype of the IPC-positive samples was assessed using monoclonal antibodies specific for CD79, CD20, CD23, CD21, CD5, λ and κ chains. Statistical correlations were sought between the histological findings and clinical expression. RESULTS: The study involved 96 patients (64 with ulcerative colitis and 32 with Crohn's disease). Two different patterns of B lymphocyte infiltrates were found in the intestinal tissue: one was characterised by a strong to moderate stromal localisation of small IgM+/CD79+/CD20-/CD21-/CD23-/CD5± IPCs (42.7% of cases); in the other (57.3%) no such small IPCs were detected in stromal or epithelial tissues. IPCs were significantly less frequent in the patients with Crohn's disease than in those with ulcerative colitis (p = 0.004). CONCLUSION: Our findings suggest that different immunopathogenetic pathways underlie chronic intestinal inflammation with different clinical expressions. The presence of small B lymphocytes resembling B-1 cells also seemed to be negatively associated with Crohn's disease. It can therefore be inferred that the gut contains an alternative population of B cells that have a regulatory function.