• Title/Summary/Keyword: singnaling

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The BMPs expression and histomorphometric study of ${\beta}-TCP$ / rhBMP-2 Grafting on the rabbit cranial bone defects

  • Lim, Byung-Sup;Jeon, Jae-Yoon;Park, Chang-Joo;Im, Jae-Jung;Hwang, Kyung-Gyun;Shim, Kwang-Sup
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.1
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    • pp.49-58
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    • 2008
  • Objective: The Purpose of the study was to investigate the bone morphogenic protein expression of rhBMP-2(recombinant human bone morphogenic protein-2) as singnaling molecule and ${\beta}-TCP$(Tricalcium phosphate) as a bone substitute and carrier medium of rhBMP-2. Materials and Methods: 16 rabbits divided into 2 group of each 8 rabbit. Two standardized bone defect, round bilateral defect was made in the cranium of the 8 rabbit of first group, and was grafted with $150{\sim}500{\mu}m$ diameter ${\beta}-TCP$ 0.25g in one side, which was soaked with rhBMP-2, and autogenous bone was grafted on another side as a positive control. Second group of 8 rabbit, only ${\beta}-TCP$ was grafted with same size and same manner. After 2, 4, 8, and 12 weeks, specimen was taken for microscopic immunohiostochemical and histomorphometric analysis. Result: Grafting ${\beta}-TCP$ with rhBMP show the early formation of the bone regenerative factor (BMP-4) and more quantity of new bone formation than only use of ${\beta}-TCP$ (8,12 week), even show less new bone formation than autogenous bone. Conclusion : The experimental study result that ${\beta}-TCP$ graft combination with rhBMP-2 as a delivery system is an effective with osteoinductive capacity and biodegradable properties, so that provide clinical availibility of composite use in reconstruction of bony defect.

Rapid Cell Death Phenotype of Streptococcus mutans under Prolonged Growth Conditions (장시간 생장 조건에서 Streptococcus mutans의 급격한 세포사 표현형 분석)

  • Kim, Jeong Nam
    • Journal of Life Science
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    • v.31 no.12
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    • pp.1072-1078
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    • 2021
  • The oral pathogen Streptococcus mutans is considered a major causative agent of dental caries in humans. The use of dental hygiene products, including toothpaste and mouthwash, is used for caries control. However, food intake can lead to the recurrence of oral microorganisms. This study aimed to explore why this bacterium dies so quickly during prolonged incubation and to assess whether this growth characteristic is closely associated with the secretion of metabolic products. Notably, the number of live S. mutans cells rapidly declined after 24 hr during the entire period tested, whereas the number of Escherichia coli cells, an indicator strain, remained steady over the same period. To test whether the S. mutans supernatants contained possible signals that accelerated the death of neighbor cells, we obtained the individual supernatants at the above time points. Following pH neutralization, the cells in which the supernatant was supplemented with glucose grew well. However, pH adjustment alone could not fully recover cell growth in conditions in which the supernatant was supplemented, with or without glucose. These phenotypes of S. mutans may be associated with signaling, not only resulting from nutrient depletion. The findings on the survival phenotype of S. mutans provide new insights into cell-cell communication in the biology of this bacterium.

Evaluation Antioxidant and Anti-inflammatory Activity of Ethanolic Extracts of Myriophyllum spicatum L. in Lipopolysaccharide-stimulated RAW 264.7 Cells (이삭물수세미(Myriophyllum spicatum L.) 에탄올 추출물의 항산화와 항염증 효과)

  • Chul Hwan Kim;Young-Kyung Lee;Min Jin Kim;Ji Su Choi;Buyng Su Hwang;Pyo Yun Cho;Young Jun Kim;Yong Tae Jeong
    • Korean Journal of Plant Resources
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    • v.36 no.1
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    • pp.15-25
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    • 2023
  • Myriophyllum spicatum L. has been used as an ornamental in ponds and aquariums, and as a folk remedy for inflammation and pus. Nevertheless, the biological activity and underlying mechanisms of anti-inflammatory effects are unclear. This study is aimed at investigating the antioxidative and anti-inflammatory activities of ethanol extract of Myriophyllum spicatum L. (EMS) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Antioxidant activity of EMS was assessed by radical-scavenging effects on ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. As inflammatory response parameters produced by LPS-stimulated RAW 264.7 cells were quantified to assess the anti-inflammatory activity of EMS. Our results showed that EMS increased FRAP and DPPH radical-scavenging activity. In EMS-treated RAW 264.7 cells, the production of NO, PGE2, TNF-α and IL-1β was significantly inhibited at the non-cytotoxic concentration. In addition, EMS significantly attenuated LPS-stimulated the toll-like receptor (TLR) 4/myeloid differentiation protein (MyD) 88 signaling pathway, and inhibited nuclear translocation of nuclear factor-kappa B(NF-κB). Positive correlations were noted between anti-inflammatory activity and antioxidant activity. In conclusion, it was indicated that EMS suppresses the transcription of inflammatory factors by inhibiting the TLR4/MyD88/NF-κB signaling pathway, thereby suppressing LPS-stimulated inflammation in RAW 264.7 cells. This study highlights the potential role of EMS against inflammation and associated diseases.