Sustainability assessment and comparison of waste management systems: The Cities of Sofia and Nis case studies.

Sustainability assessment of a waste management system is a very complex problem for numerous reasons. Firstly, it is a problem of environmental assessment, economic viability and social acceptability, and also a choice of the most practical waste treatment technique, taking into account all the specific areas in which a waste management system is implemented. For these reasons, among others, it is very important to benchmark, cooperate and exchange experiences in areas with similar characteristics. In this study, a comparison of waste management scenarios in the Cities of Nis and Sofia was performed. Based on the amount and composition of municipal solid waste, and taking into account local specifics (economic conditions, social acceptance, etc.), different scenarios were developed: landfilling without energy recovery, landfilling with energy recovery, mechanical-biological treatment, anaerobic digestion with biogas utilization and incineration with energy recovery. Scenario ranking was done using multi-criteria analysis and 12 indicators were chosen as the criteria. The obtained results show that the most sustainable scenario in both case studies is the mechanical-biological treatment (recycling, composting and Refuse Derived Fuel production). Having in mind that this scenario is the current waste management system in Sofia, these results can help decision-makers in the City of Nis in choosing a successful and sustainable waste management system.

Association of fibronectin with hypogalactosylated immunoglobulin G in gingival crevicular fluid in periodontitis.

BACKGROUND: Fibronectin (FN) can bind to immunoglobulins (Ig), influencing both the normal clearance and abnormal deposition of circulating immune complexes. This study focuses on the possible interaction between FN and IgG present in gingival crevicular fluid (GCF) of periodontitis patients and periodontally healthy controls, with the aim to determine whether such interaction may be connected with the glycosylation profile of IgG and, thus, consequentional in accumulation of proinflammatory IgG in periodontal pockets. METHODS: The study included 30 patients with initial or advanced periodontitis, and 13 periodontally healthy subjects. GCF IgG was purified and analyzed for the presence of FN and its fragments and for galactose expression. RESULTS: IgG isolated from GCF contained FN, which was bound to the IgG heavy chains. IgG from GCF of advanced periodontitis patients contained high levels of hypogalactosylated IgG, and bound more FN than IgG from GCF of the other two groups, which contained low levels of this glycoform. FN was in a degraded form in GCF from all studied patients, and a fragment of 48- to 53-kDa molecular mass seemed to be the sole one linked to IgG. CONCLUSIONS: IgG and the FN fragment of 48 to 53 kDa in GCF of periodontitis patients and periodontally healthy subjects are physically connected. This fragment was linked to the heavy chains of IgG and the reaction seemed to be particularly intensive with IgG from advanced periodontitis, which contained significantly less galactose in its sugar chains.

Glycosylation of IgG B cell receptor (IgG BCR) in multiple myeloma: relationship between sialylation and the signal activity of IgG BCR.

Little is known about the glycosylation of the isotype switched B cell receptor (BCR) in multiple myeloma, and the way it might affect receptor function. In this work IgG BCRs isolated from the individual lysates of peripheral blood lymphocytes (PBL) of 32 patients with IgG multiple myeloma and healthy controls were investigated for the expression of sialic acid (SA), galactose (Gal) and N-acetylglucosamine (GlcNAc), the sugars known to specify the glycoforms of human serum IgG. The degree of glycosylation and signaling status of all 32 isolated myeloma IgG BCRs were correlated and compared with the glycosylation of the IgG paraproteins isolated from sera of the same patients. It was shown that BCR IgG in myeloma is more heavily sialylated when compared with normal controls, that the increased sialylation of IgG BCR is associated with higher levels of tyrosine phosphorylation (signaling activity) of the IgG BCR supramolecular complex and that BCR IgG and serum IgG paraprotein from the same patient differed in all cases in the levels of terminal sugar expression. The results suggest that the development of the malignant clone in MM from post-switch B cells expressing IgG BCR at their surfaces to plasma cells secreting IgG paraprotein may be followed by permanent glycosylation changes in the IgG molecules.

Signaling status of IgG B cell receptor (IgG BCR) is indicative for an activated state of circulating B cells in multiple myeloma.

Circulating post-switch B cells have been proposed as proliferative and disseminating progenitors in multiple myeloma. It is unclear whether the class-switched antigen receptor expressed at the surface of these cells plays a role in their expansion. In this work, the signaling status of IgG B cell receptor (BCR) isolated from the lysates of peripheral blood lymphocytes of 32 patients with IgG multiple myeloma, at the time of diagnosis, was investigated by examining whether phosphorylation of BCR Igalpha and Igbeta signal transducer factors (co-receptors) or other signaling molecules was abnormal in these cells when compared with healthy controls. In IgG BCR of normal controls, weak phosphorylation of 56 and 61 kDa Src kinase-related proteins and unphosphorylated co-receptors were found. In myeloma, p56 and p61 kDa proteins, co-receptors, and other IgG BCR-associated proteins from the signal cascade were phosphorylated. Myeloma patients can be classified into subgroups by IgG BCR phosphorylation profiles which characteristically coordinated with the level of IgG paraprotein in serum and the stage of disease. There was a correlative trend between the extent of phosphorylation reduction and advanced stage of disease. Reduced phosphorylation was more pronounced with advanced stages of multiple myeloma.

Hypogalactosylation of salivary and gingival fluid immunoglobulin G in patients with advanced periodontitis.

BACKGROUND: Altered glycosylation of immunoglobulin G (IgG) has been found to affect certain immunological activities of IgG and to correlate with increased inflammation in various disease states. This work deals with the changes in distribution and galactosylation of IgG subclasses present in saliva and gingival crevicular fluid (GCF) of patients with initial and advanced periodontitis and of normal controls. METHODS: IgG subclasses were quantified by dot-blot assay, and the degrees of expression of galactose in the total IgG and its individual subclasses were estimated by lectin immunoblot assay after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) separation of IgG and by capture enzyme-linked immunosorbent assay (ELISA), using biotinylated Ricinus communis (RCA-I) and Bandeiraea simplicifolia (BS-II) lectins. RESULTS: The distribution of IgG subclasses in both fluids was found to differ in periodontal patients compared to normal controls. In the periodontitis saliva and GCF, the IgG2 subclass dominated quantitatively, regardless of periodontal status. However, galactose was found to be expressed in IgG heavy chains in normal controls and patients with initial periodontitis but not, or at barely detectable levels, in advanced periodontitis. CONCLUSION: The results suggest that the shift toward hypogalactosylated glycoforms may occur during the process of inflammation of the gingiva.