Development of a microwave ion source for ion implantations.

A microwave ion source is expected to have a long lifetime, as it has fewer consumables. Thus, we are in the process of developing a microwave ion source for ion implantation applications. In this paper, we report on a newly developed plasma chamber and the extracted P(+) beam currents. The volume of the plasma chamber is optimized by varying the length of a boron nitride block installed within the chamber. The extracted P(+) beam current is more than 30 mA, at a 25 kV acceleration voltage, using PH3 gas.

An assay system utilizing devitalized bone for assessment of differentiation of osteoclast progenitors.

The present study provides a novel assay system to examine the differentiation of osteoclast progenitors on devitalized bone slices. We used the population of bone cells liberated enzymatically from 14-day-old mouse embryonal calvariae as a source of osteoclast progenitors. The analysis of differentiation of osteoclast progenitors into preosteoclasts and mature osteoclasts was assessed in terms of the formation of TRAP-positive cells and pits or resorption lacunae, respectively, on devitalized bone slices. Osteoclasts having bone-resorbing activity appeared when the calvarial cell population was cultured in the presence of 1 alpha,25-(OH)2D3 on devitalized bone slices. The resorbing activity increased in a 1 alpha,25-(OH)2D3 dose-related manner. However, calcitonin, a potent inhibitor of differentiation and activation of osteoclast lineage cells, reduced the area of the resorption lacunae in a dose-dependent fashion. The bone-resorbing cells on the bone slices expressed an obvious ruffled border and clear zone, structures specific to mature osteoclasts. These results suggest that osteoclast progenitors in the mouse calvarial population examined differentiated into mature osteoclasts in the presence of 1 alpha,25-(OH)2D3 on devitalized bone slices. Further, using this assay system we assessed the effect of some other osteotropic factors on the differentiation of osteoclast progenitors to mature osteoclasts. IL-1, IL-6, and PTH increased the formation of TRAP-positive cells and pits and the area of resorption lacunae in a dose-dependent fashion. However, prostaglandin E2 was unable to induce the formation of resorption lacunae, although a significant appearance of TRAP-positive cells was observed at a concentration of 200 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

[Examination of the effectiveness of a screening test on the cooperation of autistic children and autism in the dental clinic].

The aim of this study was to confirm the effectiveness of a screening test on the cooperation of Autistic children in the dental clinic which was proposed by a former report. The subjects were composed of 55 autistic children making their first visit and other patients. The following results was obtained from this study. 1. The effectiveness of the screening test for the cooperation in a dental clinic was indicated from a high consistent rate (87.0%) in relation between the score which was estimated by a screening test and a explicit behaviour under dental treatment. 2. It has been shown that the patient with a score of four was as noncooperative in dental clinical procedures. 3. It was suggested that the applicable of the screening test for cooperation is from 4 years of age to 12 years of age. 4. The effectiveness of the screening test with regard to cooperation was supported by the relationship between the score estimated by a screening test and explicit behaviour under situations in regard to dental clinical procedures.

Monoclonal antibody against Porphyromonas (Bacteroides) endodontalis lipopolysaccharide and application of the antibody for direct identification of the species.

The aim of the present study was to develop a monoclonal antibody that recognizes the shared antigen of Porphyromonas endodontalis so that we could use the antibody in direct identification and detection of P. endodontalis in infectious material from apical periodontal patients. We established a hybridoma cell line producing monoclonal antibody (BEB5) specific for P. endodontalis. BEB5 antibody reacted with all of the P. endodontalis strains tested, but not with any of the other black-pigmented Porphyromonas and Bacteroides spp. The antibody reacted specifically with the lipopolysaccharide (LPS) of three P. endodontalis strains of different serotypes (O1K1, O1K2, and O1K-). Western blotting (immunoblotting) analysis confirmed the specificity of the antibody to these LPSs, because the antibody recognized the typical "repetitive ladder" pattern characteristic of LPS on sodium dodecyl sulfate-polyacrylamide electrophoretic gels. These observations demonstrate that P. endodontalis LPS is the shared antigen of this species. The antibody can specifically identify P. endodontalis on nitrocellulose membrane blots of bacterial colonies grown on agar. The antibody is also capable of directly detecting the presence of P. endodontalis in infectious material by immunoslot blot assay. These results indicate that LPS is the shared antigen of P. endodontalis and that BEB5 antibody against LPS is a useful one for direct identification and detection of the organisms in samples from apical periodontal patients.

Porphyromonas gingivalis fimbriae induce expression of the neutrophil chemotactic factor KC gene of mouse peritoneal macrophages: role of protein kinase C.

To account for infiltration of the periodontal tissues by neutrophils, the present study was undertaken to examine whether Porphyromonas gingivalis fimbriae, important structures involved in attachment of the bacteria to periodontal tissues, induce gene expression of the neutrophil chemoattractant KC in macrophages. The fimbriae induced expression of the KC gene of mouse peritoneal macrophages in a dose-dependent fashion. The peak of KC gene expression was observed as early as 1 h after initiation of the treatment. However, the gene expression was short lived, with the expression decreasing gradually after 6 h. A nuclear transcriptional assay showed that the fimbriae regulated the KC gene expression at a posttranscriptional level. We observed that the fimbria-induced KC gene expression was not regulated by endogenous or exogenous prostaglandin. Furthermore, forskolin, a potent activator of adenyl cyclase, and dibutyryl cyclic AMP were incapable of inducing KC gene expression of the peritoneal macrophages. H-8 and HA 1004, inhibitors of cyclic nucleotide-dependent protein kinases, had little effect on the fimbria-induced KC gene expression. On the other hand, the fimbria-induced KC gene expression was inhibited markedly by treatment with H-7, a potent inhibitor of protein kinase C. We also observed that phorbol 12-myristate 13-acetate, a specific activator of protein kinase C, induced KC gene expression of peritoneal macrophages in a dose-dependent fashion. In addition, the fimbria-induced KC gene expression was suppressed in the peritoneal macrophages pretreated for 24 h with phorbol 12-myristate 13-acetate. These results suggest that the KC gene expression was mediated through activation of protein kinase C and not through that of cyclic nucleotide-dependent protein kinases. The present study indicates that P. gingivalis fimbriae can induce gene expression of the neutrophil chemotactic factor KC by macrophages via protein kinase C and suggests that this factor may be involved in infiltration of neutrophils into the periodontal tissues of adult periodontal patients.