ABSTRACT
PURPOSE: Several studies have shown that the oral cavity is a secondary location for Helicobacter pylori colonization and that H. pylori is associated with the severity of periodontitis. This study investigated whether H. pylori had an effect on the periodontium. We established an invasion model of a standard strain of H. pylori in human periodontal ligament fibroblasts (hPDLFs), and evaluated the effects of H. pylori on cell proliferation and cell cycle progression. METHODS: Different concentrations of H. pylori were used to infect hPDLFs, with 6 hours of co-culture. The multiplicity of infection in the low- and high-concentration groups was 10:1 and 100:1, respectively. The Cell Counting Kit-8 method and Ki-67 immunofluorescence were used to detect cell proliferation. Flow cytometry, quantitative real-time polymerase chain reaction, and western blots were used to detect cell cycle progression. In the high-concentration group, the invasion of H. pylori was observed by transmission electron microscopy. RESULTS: It was found that H. pylori invaded the fibroblasts, with cytoplasmic localization. Analyses of cell proliferation and flow cytometry showed that H. pylori inhibited the proliferation of periodontal fibroblasts by causing G2 phase arrest. The inhibition of proliferation and G2 phase arrest were more obvious in the high-concentration group. In the low-concentration group, the G2 phase regulatory factors cyclin dependent kinase 1 (CDK1) and cell division cycle 25C (Cdc25C) were upregulated, while cyclin B1 was inhibited. However, in the high-concentration group, cyclin B1 was upregulated and CDK1 was inhibited. Furthermore, the deactivated states of tyrosine phosphorylation of CDK1 (CDK1-Y15) and serine phosphorylation of Cdc25C (Cdc25C-S216) were upregulated after H. pylori infection. CONCLUSIONS: In our model, H. pylori inhibited the proliferation of hPDLFs and exerted an invasive effect, causing G2 phase arrest via the Cdc25C/CDK1/cyclin B1 signaling cascade. Its inhibitory effect on proliferation was stronger in the high-concentration group.
Subject(s)
Humans , Blotting, Western , CDC2 Protein Kinase , Cell Count , Cell Cycle , Cell Proliferation , Coculture Techniques , Colon , Cyclin B1 , Cytoplasm , Fibroblasts , Flow Cytometry , Fluorescent Antibody Technique , G2 Phase , Helicobacter pylori , Helicobacter , Methods , Microscopy, Electron, Transmission , Mouth , Periodontal Ligament , Periodontitis , Periodontium , Phosphorylation , Real-Time Polymerase Chain Reaction , Serine , TyrosineABSTRACT
We have studied the characteristics of stress relaxation and creep on lumbar vertebrae(T12-T5) of 18 fresh corpses. We measured the stress relaxation and creep of the normal group(intact spine), the control group 1(simulating the operations by the front route) and the control group 2(simulating the operations by the back route). Then we obtained the stress, strain-time curves and data under the conditions of constant stress and strain. By using regression analysis we obtained the reduced stress relaxation and creep functions. Finally, We analyzed and discussed the effects of the operations of excising the disc intervertebrales by the front route and the back route.
Subject(s)
Humans , Male , Diskectomy , Methods , Elasticity , Lumbar Vertebrae , Physiology , General Surgery , Relaxation , Stress, MechanicalABSTRACT
According to the physiological characteristics of lumbar vertebrae in Chinese, we designed and made a lumbar vertebral fusion cage of titanium and then engaged in its biomechanical test. T12-S1 of lumbar vertebrae from 18 fresh dead bodies were used. We measured the stress relaxation and the creep effects of the normal group (T12-S1 of intact lumbar vertebrae), the control group 1(simulating operation of excising intervertebral disc and planting bone on the back route) and the control group 2(simulating operation of excising intervertebral disc and inserting fusion cage). The data and stress, strain-time curves under the condition of constant stress and strain were obtained. Regression analysis yielded the reduced stress relaxation and creep functions. Finally, we analyzed and discussed the effects of the operation of excising intervertebral disc and planting bone on the back route and the operation of excising intervertebral disc and inserting fusion cage on the stability of spine.
Subject(s)
Humans , Elasticity , Intervertebral Disc , Physiology , General Surgery , Lumbar Vertebrae , Physiology , Spinal Fusion , Spine , TitaniumABSTRACT
50.0%.CONCLUSION:The extensive use of antibacterials results in increased drug resistance,while rational use of antibiotics is the key of decreasing drug resistance and multidrug resistance.It is of great importance to analyze the variation of bacterial drug resistance in area hospital.
ABSTRACT
OBJECTIVE To investigate the drug sensitivity situation of Acinetobacter baumannii(ABA) in 3 years to instruct clinical application of the antibiotics.METHODS The drug sensitivity test data of the 428 A.baumannii(ABA) strains from 2006 to 2008 were analyzed retrospectively.RESULTS It was showed from the drug sensitivity test in vitro that the most sensitive drug for A.baumannii(ABA) was imipenem,which resistance rate was 11.3-34%.The resistance rate to amikacin was 29.8-49.5% and to penicillins was is 57.7-91%,the resistance rate to of penicillins drugs was 54-74.5%.The resistance of ABA to ampicillin,cefazolin,cefpodoxime and Cefoxitin was over 91%,and showed the multi-drug resistance features.CONCLUSIONS According to the result of drug sensitive test,the most effective antibiotics are imipenem,meropenem and polymyxin B sulfate.