Synthesis of polyimide from 5,5''-bis(bromomethyl)-2,2':6',2''-terpyridine and investigation of the polymer sorption behavior towards some metal ions

The synthesis of a terpyridine-based polyimide sorbent for solid-phase extraction (SPE) of some metal ions is described. For this purpose, 5,5''-bis(bromomethyl)-2,2':6',2''-terpyridine was polymerized with the corresponding diimide derivatives of dianhyrides to give polyimides utilizing terpyridine unit in the main chain. This polymer was used for its extraction capabilities for Pb(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II), at different pH. Under competitive conditions and at pH<0.6, the selectivity order was Pb approximately Cd approximately Zn. Enhanced selectivity was observed at pH 3.5, the order was Cu>Ni>Zn approximately Cd approximately Pb. Quantitative recoveries>97% were observed for all metals in case loading was stopped before reaching the point of breakthrough. As the synthesized polyimides are insoluble in water, solid-liquid extractions have been carried out and the resins sorption for mixture of basic and/or precious metals have been studied under various experimental conditions (reaction time and hydrochloric acid concentration).

Periodontal and alveolar bone abnormalities associated with pachydermoperiostosis

Pachydermoperiostosis (PDP) is an unusual syndrome manifested clinically by finger clubbing, extremity enlargement, hypertrophic skin changes, and periosteal bone formation. A rare case of pachydermoperiostosis (primary hypertrophic osteoarthropathy) with oral manifestations in a 47-year-old man is presented. The possible correlation between physiological mechanisms of this disease and their influence on oral periodontal tissues and alveolar bone is discussed.

Multifocal eosinophilic granuloma with sequential periodontitis-like lesions

Eosinophilic granuloma (EG) is the localized and mildest form of the triad commonly known as Langerhans cell histiocytosis. This report describes a case manifesting itself as a periodontal problem with the localized osseous lesions in jawbones which was first diagnosed as early-onset periodontitis. Later on, the diagnosis of EG was established, relying on histopathological and immunohistochemical evaluations. Immunohistochemical findings confirm that a minor component of cell aggregates is phenotypically related to Langerhans cells among the sheet-like accumulations of histiocytes and eosinophils. The aetiology of the disease remains largely unknown. Although surgical curettage of lesions is usually effective in treatment of EG of bone, corticosteroids might be used as an adjunctive. This multifocal case of EG stresses the importance of clinical follow-up examinations, since the sequential lesions appear with irregular intervals, and this may cause diagnostic problems as well as a delay in starting the treatment regimen.

Osteocartilaginous choristoma of the gingiva

An interesting example of a gingival cartilaginous choristoma is reported. The term choristoma, because of its histological structure, applies to a tumour-like mass of normal cells in an abnormal location.