Asaccharolytic anaerobic gram‐negative coccobacilli (AAGNC) isolated from infected root canals and periodontal pockets

Background/aims: Culture‐difficult bacteria, including asaccharolytic anaerobic gram‐negative coccobacilli (AAGNC), may constitute a predominant group of organisms in oral sites. This study aimed to characterize phylogenetically 10 AAGNC isolated from endodontic lesions and periodontal pockets. Methods: 16S rDNA sequence and G + C content were determined. Strains sharing more than 98% sequence similarities and similar G + C content were considered the same bacterial species. Results: One isolate resembled Dialister pneumosintes (the type species of the genus Dialister) with 35 mol% G+C content and 97% sequence similarity. Of eight isolates having 45–47 mol% G+C content, seven were identified as D. invisus and one resembled Dialister invisus with 97% sequence similarity. However the 16S rDNA sequence similarities with D. pneumosintes were relatively low, indicating the strains may belong to a new genus. The last isolate revealed 35 mol% G+C content, but had higher 16S rDNA sequence similarity with D. invisus than with D. pneumosintes. Conclusion: The group of oral AAGNC isolates need to be reclassified.     

Spectroelectrochemical studies of two-dimensional J-aggregates of cyanine dyes organized on chemically modified Au(1 1 1)

High-speed spectroelectrochemical methods—a combination of in situ reflection absorption spectroscopy with a 2 ms time resolution with fast-scan cyclic voltammetry or with a potential step method—allowed comprehensive characterization of the reversible oxidation of two-dimensional (2D) J-aggregates of typical cyanine dyes, which were organized on a cysteamine-modified Au(1 1 1). The in situ absorption spectra proved that the 2D J-aggregate could be oxidized reversibly producing well-dispersed dye positive holes that caused distinct electrochromism in the J-band. The coexisting irreversible mode of J-aggregate oxidation was strongly confined to the aggregate domain edges. Data analysis based on the simple Nernst equation allowed a hitherto difficult assessment of the standard potential of the J-aggregate, and suggested that accumulation of dye positive holes caused strongly non-ideal redox behavior. The standard potential of the J-aggregate shifted negatively with increasing aggregate size, and its systematic change with the level of J-aggregation had a simple linear correlation with the change of light absorption energy. Independent kinetic information on the interfacial electron transfer rate obtained by the potential step method provided additional support for the results of the redox equilibrium analysis and suggested markedly small reorganization energies of around 0.1 eV for the reversible J-aggregate oxidation.     

Streptococcus mutans binding to solid phase dextran mediated by the glucan-binding protein C

Streptococcus mutans GbpC is a wall-anchored surface protein which is involved in dextran-dependent aggregation. The GbpC phenotype is observed only in cells grown under stress conditions. In order to detect the GbpC protein of S. mutans, we isolated the wall fraction following digestion of the cell wall of this organism by N-acetylmuramidase, and detected the GbpC protein from S. mutans cells by western analysis with anti-GbpC serum. Interestingly, S. mutans cells exhibiting the negative dextran(alpha-1,6 glucan)-dependent aggregation (ddag) phenotype expressed the protein and could bind to immobilized dextran.     

Assessment of in vitro interleukin-2-producing capacity of peripheral blood lymphocytes from patients with periodontitis.

Abstract In this cross-sectional study, we assessed the in vitro interleukin-2 (IL-2) producing capacity of peripheral blood mononuclear cells (PBMC) and lymphocytes from patients with different forms of periodontitis. 45 patients (12 with localised early onset periodontitis (LEOP), 20 with generalised early onset periodontitis (GEOP), and 13 with adult periodontitis (AP), and 20 periodontally healthy subjects (HS), participated in this study. PBMC and lymphocytes were isolated from the subjects and their cells were stimulated with an anti-CD3 monoclonal antibody (anti-CD3 MoAb) and the secreted IL-2 levels in the culture were bioassayed. No significant differences could be found in IL-2 producing activity of PBMC between the patients and HS group. There was wide interindividual variation and high and low “IL-2 producers” were noted. We found a LEOP patient who was a high producer of IL-2 (>mean+8 SD) and 2 LEOP patients and a HS who were low producers of IL-2 (相似文献   

Eosinophilic granuloma of the ramus similar to malignant neoplasm or osteomyelitis: Report of a case

An eosinophilic granuloma was discovered in the region of the ramus of the mandible. This case occured in a very rare location limited only to the ramus, and showed similar features resembling osteomyelitis or malignant neoplasm at different stages of the disease. The radiographic findings indicated a diagnosis of malignant neoplasm and the scintigraphic manifestations showed that of osteomyelitis. The histopathological examinations showed different manifestations in accordance with the respective stages of the disease. This case was finally diagnosed as eosinophilic granuloma showing rapid regression.