Emodin is a bioactive compound isolated from the root and rhizomes of Rheum plamatum L. (polygenaceae), which is known as a traditional Chinese and Japanese medicine. In the present study, the effect of emodin on YD-15 mucoepidermoid carcinoma cells and its molecular mechanism were investigated. This study shows that emodin significantly inhibits the growth of YD-15 cells. Activation of caspase-3 and PARP is triggered by emodin and it increases sub-G1 population and the number of YD-15 cells with nuclear condensation and fragmentation. In addition, we found that emodin significantly decreases myeloid cell leukemia 1(MCL-1). These results suggest that MCl-1 is an important molecule for emodin-induced apoptosis. Taken together, emodin inhibits cell viability and induces apoptosis via down-regulation of MCL-1 and it can be a new potent anticancer drug candidate for the treatment of mucoepidermoid carcinoma
Malignant tumor cells outgrow new blood vessel formation and tend to be in hypoxic state. Hypoxic cancer cells adapt to hypoxic conditions by transforming its characteristics. On the other hand, one of the most important features of cancer cells is that carcinoma cells loses its inherent epithelial phenotype and acquires mesenchymal characteristics, called as epithelial-mesenchymal transition(EMT). It has been already well known that EMT contributes to tumor invasion and metastasis. The present study investigated whether hypoxia play a major role in induction of phenotypic changes of oral squamous cell carcinoma(OSCC). Furthermore, the mechanism of EMT in oral squamous cell carcinoma cells by hypoxia has been clarified. To mimic hypoxic condition, cobalt chloride and desferoxamine, well-known hypoxic mimetic agents, were used. This study shows that hypoxia suppresses the expression of E-cadherin(epithelial marker) and increases vimentin and N-cadherin( mesenchymal markers) in OSCC. In addition, α5 integrin protein, which is a receptor for fibronectin and an important molecule for tumor invasion, is prominently induced by hypoxia.
Cyclosporin A(CsA) as immunosuppressive drug is used to prevent immune reactions after organ transplant. And also It is reported that the effect of CsA on osteoblast differentiation has been controversial according to dosage. The purpose of this study was to examine the effect of various CsA concentrations on osteoblast differentiation. According to different concentration o f CsA, growth curve, apoptosis index MTT assay, ALP activation and osteocalcin secretion, in cultured NHost were analyzed. Treating osteoblasts with low concentrations of CsA increased growth rate, MTT assay activity, ALP activation and osteocalcin protein levels in a dose-dependent manner, while high concentration showed opposite results. Therefore, these results showed that low concentrations of CsA increased osteoblast differentiation, while high concentrations elicited an opposite response, showing inhibition of CsA on osteoblast differentiation. It suggested that different CsA concentrations might play in regulating NHost differentiation, and its specific activation of lower concentration will represent a viable anabolic therapy for bone resorption disease in future.
Diabetic patients tend to exhibit delayed bone formation and osteoblast differentiation, which results in osteopenia. Recently, numerous clinical reports suggest that 635-nm light irradiation improves bone regeneration and wound healing, and reduces pain in patients suffering from diabetes. The purpose of the present study was to test the hypothesis that 635-nm irradiation can influence bone formation by MC3T3-E1 osteoblasts cultured on high concentrations of glucose(25mmol/L D-glucose) in the presence or absence of phorbol 12-myristate 13-acetate(PMA), and to establish an in vitro pathological model of bone formation. The effect of 635-nm irradiation on bone formation was investigated using Alizarin Red S staining, and alkaline phosphatase enzyme activ ity and calcium deposition assays. In addition, gene expression of the o steogenic markers BMP-2, osterix and osteocalcin were assayed by RT-PCR. Calcium deposition by MC3T3-E1 cells was reduced in the presence of high concentrations of glucose or by PMA supplementation. However, 635-nm irradiation led to an increase in calcium deposition by MC3T3 cells, followed by increased bone mineralization. mRNA expression of BMP-2 and osterix at an early stage and of osteocalcin at a late stage was significantly upregulated by 635-nm irradiation in MC3T3-E1 cells supplemented with high concentrations of glucose. Irradiation at 635 nm increases bone mineralization in MC3T3-E1 cells cultured in vitro on high concentrations of glucose and alters osteogenic gene expression, which accelerates bone formation in hyperglycemic conditions.
The incidence of multidrug-resistant strains of Staphylococcus aureus continues to increase in hospitals and the community all over the world. As the importance of miner surgery in dentistry gets greater recently, the frequency in use of antibiotics has been increasing. Although several cases of acquired infection in oral cavity in dental hospital has been reported, the research on isolation of S. aureus and evaluation of its antibiotic resistance from outpatients in the dental clinic has not been found yet. The aim of this study was to evaluate the antimicrobial resistance of S. aureus isolates. The isolation rate of S. aureus were 41.7% in dental hospital personnel, 60.4% in outpatients and 62% in dental hygiene students. S. aureus which showed resistance to penicillin were 88.6%, ampicillin 88.6%, erythromycin 8.6%, tetracycline 4.3%, oxacillin 4.3%, cefoteten 4.3%. Six strains of S. aureus showed the susceptible to all antibiotics tested. Sixty-four(91.4%) strains were multiple antibiotic resistance. Fifty-two strains(72.8%) resisted to AM-P. and Seven strains(10.0%) resisted to AM-P-E, AM-P-GM, AM-P-TE.
Currently, dental implants are generally used for reconstruction of oromaxillofacial defects. Implants are widely used in dental and medical fields. The materials of implants are variable such as metals and ceramics. The materials of implants must be have not toxicity and biocompatibility to host and mechanical(physical) strength. Bones must be attached to titanium surface without any other tissues. many researcher's had studied for raising the osseointegration through various method which are including implants designs and materials. It was reported over 95% success ratio. many researcher's study the methods which are enhancing the speed of bone remodelling and osseointegration. Thermo dynamic therapy is one of the method to accelerlate the speed of bone remodelling and osseointegration. Thus it raise stability of implants. The purpose of this study was to evaluate the effect of diode laser irradiation for ossoeintegration in implant interface and between the implants threads. 24 New Zealand white rabbits which were about 3kg weight, used for experiment. 2 implant's were implanted every rabbit's tibia. 2 weeks, 4 weeks, 8 weeks after implantation, tissue sample were removed from sacrificed rabbit's tibia. 8 rabbit's were sacrificed every 2, 4, 8 weeks and undecalcified sample were made from tissue sample. We have investigated the undecalcified samples by back scattered electron microscope. We have analysied the length rate and area rate in implant interface and inside the threads. The results were as follows. 2 weeks, 4 weeks, 8 weeks experimental groups which were irradiated low level laser therapy showed rapid bone remodelling than control groups. It was suggested that Initial bone remodelling may be effected by LLLT because of implant bone contact ratio between 4th weeks and 8th weeks had no siginifant difference. Initial bone remodelling may be more influenced than later bone remodelling by LLLT because of new bone formation area ratio between implant threads had no significant differences during 4th to 8th weeks. According to above results, low level laser irradiation accerlate the new bone formation in implant interface and inside the implants threads at initial stage. there were many factors which are increasing the bone remodelling, because there were many differences between experimental and control groups. Low level laser irradiation were helpful for increasing the initial stage of bone remodelling because of above results.
Photodynamic therapy(PDT) is recently developed as an effective treatment for malignant disease. Carboplatin, a less nephrotoxic analog of cisplatin, has been widely used for the treatment of multiple malignancies. In this study, we investigated the cytotoxic and apoptotic effect of combined modality of photofrin mediated PDT with cisplatin and carboplatin on KB cell human oral cancer cell line in vitro. The a ttached KB cells were incu bated with c isplatin(0.04mg/ml) and carboplatin(0.02mg/ml) for 24h at 37℃ and followed by photosensitization with photofrin for 6h and laser irradiation with 630nm LED at an intensity of 2.0 J/cm2 for activating photofrin for 15min. Then MTT assay and SYTO 16 green & Propidium iodide (PI) double staining were used respectively to measure the cytotoxicity and nuclear morphology at 24h after PDT. This study demonstrates that the combined modality with carbopaltin resulted in enhanced apoptotic cell death as well as cytotoxic e ffect on KB c ells in vitro, which s uggests the feasibility of combined modality and the possibility o f reducing the effective dosage of photofrin and carboplatin and lowering the side effects on normal cells