Quantitative detection of human cytomegalovirus in aggressive and chronic periodontitis lesions / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To establish a quantitative real-time PCR assay for the detection of human cytomegalovirus (HCMV) DNA load in subgingival specimens from the patients with aggressive and chronic periodontitis, and to investigate the relationship between HCMV infection and the periodontal status.</p><p><b>METHODS</b>A total of 114 subgingival plaque specimens were taken from 18 subjects with aggressive priodontiti (AgP), 24 subjects with chronic periodontitis (CP) and 15 healthy control subjects. Standard quantification was performed with recombinant plasmid containing a conserved fragment of HCMV. The SYBR Green I fluorescent quantitative real-time PCR assay was established based on positive plasmid. HCMV DNA load in the specimens were detected with quantitative real-time PCR based on SYBR Green I fluorescence.</p><p><b>RESULTS</b>HCMV were detected in 58.3% of AgP sites and 41.7% of CP sites, however, only 6.7% of periodontally-healthy sites were HCMV positive. The detection rate of HCMV in periodontitis lesions was significantly higher than in periodontal health (P < 0.01). High copy-counts more than 10(4) of HCMV were detected in 33.3% of AgP sites, which were significantly higher than in CP sites (10.4%) (P < 0.05).</p><p><b>CONCLUSION</b>Subgingival infection with HCMV is closely associated with periodontitis. Active HCMV infection may be related to the rapid tissue destruction of AgP.</p>

Effects of high mobility group box 1 in activating periodontal ligament fibroblasts to express cytokine / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the influence of high mobility group box 1 (HMGB1) on the expression of interleukin 6 (IL-6), receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) on periodontal ligament fibroblasts.</p><p><b>METHODS</b>Human periodontal ligament fibroblasts were stimulated with HMGB1 at concentrations of 10, 30, and 100 ng x mL(-1) for 24 h. RT-PCR and Western blot analysis were performed to check mRNA and protein expression of IL-6, RANKL and OPG on the cells.</p><p><b>RESULTS</b>The ratio of RANKL/OPG was increased at both mRNA and protein level after HMGB1 stimulation at 10, 30, 100 ng x mL(-1). Inflammatory cytokine IL-6 was upregulated by HMGB1 at the concentration of 100 ng x mL(-1).</p><p><b>CONCLUSION</b>Increased ratio of RANKL/OPG and IL-6 on periodontal ligament fibroblasts suggests that HMGB1 might play a role in the pathogenesis and progression of periodontal disease.</p>

Levels of inflammation cytokines in patients with coronary heart disease and periodontal disease / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine the level of high-density lipoprotein cholesterol (HDL-C), serum C-reactive protein (CRP) and inflammation cytokines and investigate the concentration between periodontal disease and coronary heart disease (CHD).</p><p><b>METHODS</b>Sixty-six patients with CHD and chronic periodontitis [(C+P) group], forty-four with only CHD (C group), fifty-six with only chronic periodontitis (C group), and forty-three healthy controls (H group) were included in this study. The diagnosis of chronic periodontitis and CHD was based on accepted clinical criteria. Serum levels of HDL-C, CRP, IL-6, tumor necrosis factor (TNF)-alpha and IL-1beta were tested in all patients and controls.</p><p><b>RESULTS</b>The periodontal conditions of these four groups were significantly different (P<0.05). The clinical periodontal parameters [probing depth (PD), attachment loss (AL), and bleeding on probing (BOP)] in patients with (C+P) group, P group, C group and H group were [(4.55+/-0.85) mm, (3.78+/-0.34) mm, 69.6%], [(4.06+/-0.61) mm, (3.05+/-0.44) mm, 63.6%], [(1.85+/-0.67) mm, (1.26+/-0.39) mm, 20.5%], [(1.12+/-0.33) mm, (0.42+/-0.83) mm, 4.6%], respectively. The levels of HDL-C in H group, C group, P group and (C+P) group were (1.42+/-0.21), (1.22+/-0.18), (1.24+/-0.21) and (1.04+/-0.22) mmol/L, respectively. T compare with other three groups, the level of HDL-C in (C+P) group is the lowest. The levels of CRP, IL-6, TNF-alpha and IL-1beta in (C+P) group were significantly higher than other groups (P<0.05).</p><p><b>CONCLUSIONS</b>HDL-C, CRP, IL-6, TNF-alpha and IL-1beta may be associated with the pathogenesis of periodontitis and CHD. There may be a relationship between the two diseases.</p>

Ultrasound-mediated microbubble destruction enhances bone morphogenetic protein-2 gene expression in mouse skeletal muscles / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore whether ultrasound-mediated microbubble destruction can enhance the expression efficiency of plasmid pIRES-rhBMP2-EGFP for bone morphogenetic protein-2(BMP-2) in mice skeletal muscle.</p><p><b>METHODS</b>Twenty four male BALB/c mice were divided into four groups. The naked plasmid was injected into the pretibial muscle or the quadriceps muscle (group A and group C) without ultrasound-mediated microbubble destruction method. Micobubbles with plasmid were injected into the pretibial muscle or the quadriceps muscle (group B and group D) with destructing microbubbles by ultrasound immediately. Twelve mice (group A and group B, 30 microg plasmid injected) were killed after 7 days and the tissue samples of the pretibial muscle were obtained to observe the expression of enhanced green fluorescence protein (EGFP) by inverted fluorescence microscope, gene transfection efficiencies were quantified by counting EGFP positive fibers on mice skeletal muscle. After 14 days, the other twelve mice (group C and group D, 100 microg plasmid injected) were killed and immunnohistochemical technique was applied to detect the rhBMP-2 gene expression.</p><p><b>RESULTS</b>The percentage of GFP-positive fibers was significantly lower in the group A than that in the group B. After 14 days, expression of rhBMP-2 was detected in cells and interstitial spaces in the group C and group D, and expression efficiency of rhBMP-2 in the group D was significantly higher than that in the group C.</p><p><b>CONCLUSION</b>Ultrasound-mediated microbubble destruction could enhance the transfection and expression efficiency of rhBMP-2 gene in skeletal muscle of mouse in vivo. It is a new gene therapy method for periodontal regeneration.</p>

Ultrasound-mediated microbubble destruction enhances exogenous gene expression in NIH3T3 cells in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the transfection efficiency of the recombinant human bone morphogenetic protein-2 (hBMP-2) gene in targeted cells by ultrasound-mediated microbubble destruction.</p><p><b>METHODS</b>NIH3T3 cells' anabiosis was completed and went down to the 3rd or 4th generation, and cultured in 6 well plates. The cells were divided into 2 groups: Plasmid DNA and Lipofectamine 2000 group (liposome group), plasmid DNA and ultrasound and microbubble group (ultrasound-mediated microbubble destruction group). Plasmid DNA was transfected into cells with liposome or ultrasound and microbubble. 24-48 hours later, the transfection efficiency and the concentrations of hBMP-2 were measured with fluoresence microscope and enzyme-linked immunosorbent assay (ELISA) respectively. The data were analyzed by curve fitting and t-test of SPSS 11.5.</p><p><b>RESULTS</b>The transfection efficiency rate was (7.30 +/- 1.58)% in liposome group, compared with (11.77 +/- 3.16)% in ultrasound-mediated microbubble destruction group (P< 0.05). The concentration of hBMP-2 after transfection was (1164.35 +/- 724.67) pg/mL in liposome group, versus (2932.70 +/- 656.27) pg/mL in ultrasound-mediated microbubble destruction group (P<0.05).</p><p><b>CONCLUSION</b>Ultrasound-mediated microbubble destruction could significantly improve the transfection efficiency and expression of hBMP-2 gene in NIH3T3 cells. It may provide a new and effective gene delivery system for gene therapy in periodontal regeneration.</p>

Effects of minocycline on biobehavior of human periodontal ligament cells in vitro / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the influence of minocycline on the proliferation and biosynthesis of human periodontal ligament cells (HPDLCs) in vitro.</p><p><b>METHODS</b>Various concentrations of minocycline (1, 5, 20, 100, 500, 2 500 mg/L) were added to the medium of cultured HPDLCs respectively. After co-incubated for 2 days, cell morphology was observed under reverse microscope, cell proliferation activity was assayed using MTT, the total amount of protein was detected with Coumassie Bright Blue method and DNA synthesis was measured by (3)H-TdR.</p><p><b>RESULTS</b>The presence of minocycline not exceeding 500 mg/L in the medium resulted in no morphological change of HPDLCs. Moreover, at a concentration range of 5 to 100 mg/L, minocycline significantly enhanced the proliferative activity and biosynthesis of HPDLCs (P < 0.01). However, higher concentration (2 500 mg/L) not only changed cell morphology under microscope, but also significantly inhibited cellular activity.</p><p><b>CONCLUSIONS</b>The results suggest that proper doses of minocycline could promote biobehavior of HPDLCs, while higher concentrations of minocycline had cytotoxic effect which may intervene affect tissue repair and regeneration.</p>

Biological effects of tetracycline on cultured human periodontal fibroblasts / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the biological effects of tetracycline on cultured human periodontal ligament fibroblasts (HPDLFs).</p><p><b>METHODS</b>Increasing concentrations of tetracycline (1, 5, 20, 100, 500, 2500 microg/ml) were added to the medium of cultured HPDLFs, respectively. After co-incubated for 2 days, cell morphology was observed under reverse microscope, meanwhile, cell proliferation activity was assayed using MTT, the total amount of protein was detected with Coumassie Bright Blue method and DNA synthesis was measured by 3H-TdR.</p><p><b>RESULTS</b>Over a concentration range of 1 to 100 microg/ml, cells demonstrated a normal appearance, spindle or fusiform shaped. Moreover, at a concentration range of 20 to 100 microg/ml, tetracycline significantly enhanced the proliferating activity and biosynthesis of HPDLFs (P < 0.01). However, higher concentration (2500 microg/ml) not only changed cell morphology, but also significantly inhibited cellular activity.</p><p><b>CONCLUSION</b>The results suggested that proper doses of tetracycline could promote proliferation and biosynthesis of HPDLFs while higher concentrations of tetracycline had cytotoxic effect.</p>

The effect of bFGF on proliferation of periodontal fibroblast-like cells of dogs / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effects of basic fibroblast growth factor(bFGF) on proliferation of periodontal fibroblast-like cells in vivo.</p><p><b>METHODS</b>A U-shaped osseous defect was produced on the buccal side of the mesial root. Four posterior teeth were conducted in four quadrants. Each quadrant included 4 groups: control, bFGF, expanded polytetrafluoroethylene(ePTFE) membrane, bFGF + ePTFE. Each time the 4 teeth sites in one quadrant were operated weekly and each dog experienced 4 times of operations. Bromodeoxyuridine(BrdU) was injected 1 hour prior to sacrificing the dogs at 4 weeks after first surgery. Immunohistochemical method was applied to count the BrdU-labeled fibroblast-like cells.</p><p><b>RESULTS</b>The number of BrdU-labeled cells reached the maximum at the 2nd week among all groups and then, decreased with time. Both bFGF and bFGF + ePTFE treated group had significantly more BrdU+ cells than remained control or ePTFE groups (P < 0.05) at 1st, 2nd weeks after surgery.</p><p><b>CONCLUSION</b>2 weeks after periodontal surgery is active phase of proliferation of periodontal fibroblasts. bFGF enhances fibroblast proliferation in early periodontal wound healing, and in turn accelerate periodontal regeneration.</p>