The biological effects of drug-loaded biodegradable novel membrane for guided bone regeneration (GBR) was evaluated. The membranes were polyglycolic acid mesh coated with poly-L-lactic acid containing flurbiprofen, tetracycline or PDGF-BB. Porous structure was generated in the membranes by using a phase inversion method. The membrane was less toxic, nicely biodegradable and biocompatible for 8 wk after implantation in the dorsal skin of the rat. The drugs released from the membranes were shown to be effective for new bone formation. Tetracycline, flurbiprofen or PDGF-BB loaded membrane was markedly effective for osteoid tissue and new bone formation in the bony defect prepared in rat calvaria to compare with that by unloaded membrane. These results suggested that drug-loaded biodegradable barrier membrane might be a potential tool for GBR in periodontal therapy.

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ratory. About 85% of these obsidians originated from the Paektusan volcano (Korea); obsidian of Japanese origin was found only at Shinbuk. INAA analyses on 6 obsidian samples from the Hahwageri and Junghnugri sites are in good agreement with our PIXE results and those of the previous report by Popov et al. (2005).

Airway hyperresponsiveness (AHR) is a characteristic feature of asthma, but is also frequently demonstrated by children and adults with chronic obstructive lung diseases. AHR is usually measured by bronchial challenges using direct or indirect stimuli. The aim of this study was to compare these two types of bronchial challenge in children with post-infectious bronchiolitis obliterans (BO).Methacholine and adenosine 59-monophosphate (AMP) challenges were used as tools for the evaluation of AHR to direct and indirect stimuli, respectively, in children with post-infectious BO (n528). These results were compared with those of asthmatic (n530) and control children (n525).Altogether, twenty-two patients (78.6%) with post-infectious BO were hyperreactive to methacholine with a provocative concentration causing a 20% fall in forced expiratory volume in one second (PC20) of ,16 mg?mL -1 , but only six (21.4%) were hyperreactive to AMP with a PC20of ,200 mg?mL -1. All patients with asthma responded positively to methacholine, and most (28, 93.3%) also responded positively to AMP. The majority of controls were insensitive to both challenges.Airway hyperresponsiveness to methacholine is a frequent, but by no means universal, finding in children with post-infectious bronchiolitis obliterans, but is usually not accompanied by airway hyperresponsiveness to adenosine 59-monophosphate. This finding suggests that airway hyperresponsiveness in patients with post-infectious bronchiolitis obliterans has characteristics that differ from those of asthmatic subjects.

Recent research and monitoring undertaken by various institutions have emphasized measurements of river-water quality. Based on the results, government agencies have set guidelines to improve river-water quality management. However, the relationship between water quality and land use/land cover (LULC) has not been examined closely in South Korea to date. This study investigated this relationship in the Imgok River watershed. For this study, the relationship between water quality parameters, e.g. metallic ions, biological oxygen demand and chemical oxygen demand (BOD and COD), NH₃, NO₃ and PO₄ levels and land-use types (abandoned mine land, forest/grassland, agricultural, livestock and residential areas) was examined by correlation analysis with significant level (p<0.05) and principal component analysis (PCA). Applying PCA to water quality parameters according to land-use coverage, the principal component impacting river water quality were found to be the pH, metallic ions, BOD, PO₄, COD and total suspended solids (TSS) for abandoned mine land (AML) coverage; BOD, NO₃ and PO₄ for forest/grassland areas; TSS, NO₃, and PO₄ for agricultural land; BOD, COD, NH₃ and NO₃ for livestock coverage; and BOD, COD, NH₃ and PO₄ for residential areas. For the AML, the pH exhibited a significant negative correlation with other water quality parameters at the significant level (p<0.05). Grassland showed significant positive correlations of BOD with values of 0.837 NO₃ and 0.514 PO₄. In agricultural land, TSS had a significant negative correlation with value of -0.772 PO₄. For livestock coverage, BOD had significant positive correlations with values of 0.865 COD, 0.629 NH₃, 0.709 NO₃ and 0.472 TSS. In residential areas, COD was significantly positively correlated with values of 0.988 BOD and 0.856 PO₄, and TSS was highly positively correlated with value of 0.810 NO₃ but highly negatively correlated with value of -0.702 PO₄. Based on the above, LULC is a significant factor to influence on river water quality and this relationship should be based on the management plan for river water quality control. Future work will be conducted to take more samples in the entire river and season, to run water quality model and to choose a new method for better analysis and more accurate relationship between land-use and water quality.