Effects of compressive stress on the expression of M-CSF, IL-1beta, RANKL and OPG mRNA in periodontal ligament cells / 대한치과교정학회지

OBJECTIVE: The aim of this study was to determine if human PDL cells can produce osteoclastogenic mRNA and examine how compressive stress affects the expression of osteoclastogenic mRNA in human PDL cells. METHODS: Human PDL cells were obtained from biscupids extracted for orthodontic treatment. The compressive force was adjusted by increasing the number of cover glasses. PDL cells were subjected to a compressive force of 0.5, 1.0, 2.0, 3.0 or 4.0 g/cm2 for 0.5, 1.5, 6, 24 or 48 hours. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed to examine levels of M-CSF, IL-1beta, RANKL, OPG mRNA expression. RESULTS: Human PDL cells could produce M-CSF mRNA. Human PDL cells under compressive stress showed increased M-CSF, IL-1beta and RANKL mRNAs expression in a force (up to 2 g/cm2) and time-dependent manner. However, OPG mRNA expression was constant regardless of the level and duration of stress. CONCLUSIONS: Continuous compressive stress induced the mRNA expression of osteoclastogenic cytokines including M-CSF, RANKL, IL-1beta in PDL cells. Together with an unchanged OPG mRNA level, these results suggest that compressive stress-induced osteoclastogenesis in vivo is partly controlled by M-CSF, RANKL and IL-1beta expression in PDL cells.

Home-made Rapid Urease Test for Detection of Helicobacter pylori Infection / 대한임상미생물학회지

BACKGROUND: The rapid urease test has been widely used for detection of Helicobacter pylori infection because it is easy, simple and rapid result. The CLO test and PyloriTek test observe color changes after the gastric biopsy specimens are inerted into the test kits. Because H. pylori is not evenly distributed in the gastric mucosa, grinding or mincing of gastric specimens prior to culture enhances isolation rate of H. pylori. Therefore, we evaluated the effects of rubbing the gastric biopsy specimens onto the urea soaked filter paper in this home-made rapid urease test. METHODS: Forty-three patients referred for upper gastrointestinal tract endoscopy were evaluated for H. pylori infection. The home-made rapid urease test was prepared by soaking a piece of Whatman No. 2 filter paper in 2% urea agar. We compared the results of the home -made rapid urease test with histologic examination, gram stain, CLO test and culture. RESULTS: Of forty-three patients, 28 were found to be H. pylori-positive either by gram stain or by culture. The sensitivity and specificity of CLO test, based on the results of gram stain and culture were 85.7% and 92.9%. The sensitivity and specificity of home -made rapid urease test, based on the results of gram stain and culture were 92.9% and 92.9%. CONCLUSIONS: The home-made rapid urease test is faster and shows a high sensitivity and specificity.