Experimental study on co-culture of salivary adenoid cystic carcinoma cells and ganglia / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To construct the co-culture models of salivarya denoid cystic carcinoma (SACC) cells and dorsal root ganglia (DRG) of chickens and investigate the promotive effects of SACC on neural tissue.</p><p><b>METHODS</b>Glass-base culture dish was adopted to construct co-culture model of SACC-83 cells and DRG. SACC-83 cells were seeded in the medium pore with DRG around them. Outgrowth of neuronal processes was observed. Then DRG was cultured in the conditioned medium of SACC-83, with the groups of conditioned medium of MC3T3-E1 and HGF, the group of cell lysis buffer, the groups of serum-free medium and serum-plus medium as the controls. Outgrowth of neuronal processes was also recorded and compared with control groups.</p><p><b>RESULTS</b>In the co-culture model of tumor and neuronal tissue, SACC-83 cells produced a suitable microenvironment in which neuronal processes remarkably grow. Neuronal processes of most DRG displayed growth tendency toward SACC. The group of conditioned medium from SACC-83 manifested obvious promotive effects on DRG.</p><p><b>CONCLUSIONS</b>Co-culture model of tumor and neuronal tissue was successfully constructed, with which the promotive effects of tumor on outgrowth of neuronal processes could be observed. So hypothesized that SACC could secrete some neurotrophic factors to guide peripheral nerves gemmating and to trigger the cascade of the neural invasion in succession.</p>

Soft and hard tissue changes in Class II division 1 patients treated with Tip-Edge plus appliance / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the soft and hard tissue changes in Class II division 1 patients treated with Tip-Edge plus technique.</p><p><b>METHODS</b>Sixteen Class II division 1 patients (7 boys and 9 girls) with mandibular retrusion in permanent dentition were selected and treated with Tip-Edge plus appliance. Lateral cephalometric films were analyzed before and after treatment. The effects were evaluated with Holdaway soft tissues analysis and routine cephalometric analysis methods. The arithmetic mean and standard deviation were calculated for each variable. Paired t-test was performed.</p><p><b>RESULTS</b>The average treatment time was 16 months. Normal overjet and overbite were established with retroclination of upper incisors and proclination of lower incisors. U1-NA(°) and U1-NA (mm) decreaed by (15.40 ± 5.31)° and (4.16 ± 1.82) mm (P < 0.01). NLA showed an average increase of (-16.60 ± 5.29)° (P < 0.01). Remarkable soft tissue change was noted after the treatment.</p><p><b>CONCLUSIONS</b>The profile in Class II division 1 patients could be quickly and efficiently improved after treatment with Tip-Edge plus technique.</p>

Effect of ultrasound on osteoprotegerin and receptor activator nuclear factor kappaB ligand expression during root resorption in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of pulsed ultrasound on the expressions of osteoprotegerin (OPG) and receptor activator nuclear factor kappaB ligand (RANKL) during root resorption in a mouse model of orthodontic tooth movement.</p><p><b>METHODS</b>Thirty-two male Wistar rats (6-8 weeks old) were randomly assigned into 4 equal groups, including the blank control group, two ultrasound exposure groups with daily local LIPUS stimulation (100 and 150 MW/cm(2)) for 10 days during mechanical loading, and the control group with mechanical loading but not LIPUS exposure. Nickel-titanium closed-coil springs were used to generate 100 g mesial force for 10 days to move the maxillary right first molars. The expression of OPG and RANKL proteins at the compression sites was detected by immunohistochemistry.</p><p><b>RESULTS</b>Ultrasound stimulation significantly up-regulated the expression of OPG and down-regulated RANKL expression (P<0.05). The expressions of OPG and RANKL showed significant differences between the two ultrasound exposure groups (P<0.05).</p><p><b>CONCLUSION</b>Ultrasound stimulation might be useful to protect against root resorption and accelerate its repair by regulating the expressions of OPG and RANKL.</p>

Experiment on inducing human periodontal ligament stem cells into adipose cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the capability of human periodontal ligament stem cells (PDLSCs) differentiating into adipose cells in vitro and to determine their changes in cell morphology, structure and function during differentiation.</p><p><b>METHODS</b>PDLSCs isolated by magnetic-activated cell selection were treated continuously with adipogenic medium for 21 d. Then the cell morphology, ultrastructure, adipose specific markers of low density lipoprotein (LPL) and peroxisome proliferator activated receptor-gamma (PPAR-gamma) were analyzed by inverted contrast microscope, trans mission electron microscope (TEM), flow cytometry, immunofluorescence, RT-PCR and Western blot, respectively. These adipose-like cells were also identified by oil red O staining to determine the formation of lipid droplet, and the non-induced cells were used as control.</p><p><b>RESULTS</b>After continuous induction, the treated cells differentiated into adipose-like cells with round shape, and large amount of lipid drop in cytoplasm. 96.54% of the PDLSCs were found to differentiate into adipose cells as showed by flow cytometry, the specific markers of LPL mRNA and PPAR-gamma mRNA, and oil red O staining, respectively. Further, PPAR-gamma protein was detected in the induced cells in a time-dependent manner.</p><p><b>CONCLUSION</b>Human PDLSCs have the potential of differentiating into adipose cells under appropriate condition, and the differentiated cells exhibited characteristics of adipose cells both from cell morphology and from their functions.</p>

Changes of the ultrastructures of temporomandibular joint after removal of emotional stress factors in rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To examine the changes of the ultrastructures of temporomandibular joint after removal of the emotional stress factors in rats.</p><p><b>METHODS</b>Thirty-two 12-week-old male Wistar rats were divided into two groups randomly, experimental group and control group. Each group was divided into two subgroups according to execution time, 9-week subgroup and 12-week subgroup with eight rats in each subgroup. Chronic unpredictable stress animal model were firstly established in experimental group in the first 6 weeks, then all the stimulation factors removed and breed normally. After 9 weeks, rats in 9-week subgroup were killed. After 12 weeks, rats in 12-week subgroup were killed. All condyles and articular discs were dissected and observed by scanning electron microscope.</p><p><b>RESULTS</b>There was some recovery in condyles and articular discs in experimental group under scanning electron microscope. The gelatum on the surface of condyles increased, collagen fibrils became regular and deep layer collagen fibrils less exposed. There were no such obvious changes on the surface of condyles and articular discs in control group.</p><p><b>CONCLUSIONS</b>The ultrastructure injures of temporomandibular joint in rats induced by emotional stress could be reversed if the stress factors were removed.</p>

In vitro analysis of intake of minocycline by mature rat mandibular osteoblasts / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To observe the intake of minocycline and its amount in mature rat mandibular osteoblasts (MRMOB) in vitro, and to identify the feasibility of intracellular anti-bacterial activity of minocycline.</p><p><b>METHODS</b>Four groups of MRMOB were incubated in 100 mg/L minocycline for 15, 30, 45 and 60 minutes respectively, and the accumulation of minocycline within MRMOB was measured using a fluorescence spectrophotometer.</p><p><b>RESULTS</b>The intracellular accumulation amount of minocycline in the four groups of MRMOB was (17.29 +/- 1.49), (16.87 +/- 1.57), (16.96 +/- 1.67) and (17.94 +/- 1.63) mg/g respectively after osteoblasts were cultured in Dulbecco's modified Eagle's medium (DMEM) which contained minocycline for 15, 30, 45 and 60 min. There was no significant difference in amount of minocycline among the four groups of MRMOB.</p><p><b>CONCLUSIONS</b>The mature rat mandibular osteoblasts can ingest minocycline, and the accumulation amount of minocycline in MRMOB is irrelevant with the exposure time of MRMOB to minocycline.</p>

Integrity of multilayer of human periodontal ligament fibroblasts and human gingival fibroblasts grown on filter membrane of Transwell / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the integrity of multilayer of human periodontal ligament fibroblasts (HPDLF) and human gingival fibroblasts (HGF) on filter membrane of Transwell and to provide basis for the drug transcellular transport by the HPDLF and HGF in the hypothesis of delivering medicine to the periodontium and whole body through the root canal.</p><p><b>METHODS</b>HPDLF and HGF derived from the primary culture were seeded on polycarbonate filter membrane of transwell respectively. After 1, 2, 3 and 4 weeks of culture, transepithelial electrical resistance (TEER) was detected and the growth of HPDLF and HGF observed by light microscope. After 2 weeks of culture, section of filter membrane where HPDLF and HGF lived was observed with light microscope and transmission electron microscope (TEM), and the permeability of the drug transport cell models was measured with fluorescein sodium.</p><p><b>RESULTS</b>HPDLF and HGF converged 1 week after inoculation, and the cells connected each other tightly and completely 2 weeks later. Observation of section of filter membrane by light microscope and TEM revealed a stratified cell growth of HPDLF and HGF 2 weeks after inoculation, and TEER of HPDLF and HGF were (56.14 +/- 7.43) and (57.34 +/- 7.62) ohm.cm(-2) respectively. The values of TEER remained the same level until 4 weeks later. Two weeks after inoculation, the paracellular transport of fluorescein sodium was less than 1% after the cell models were incubated for 30 min.</p><p><b>CONCLUSIONS</b>Stratified cell layers of HPDLF and HGF grown on filter membrane of Transwell are analogous to periodontal membrane and gingiva 2 weeks after inoculation, the test results of permeability and TEER were consistent with the demands of development of cell models. HPDLF and HGF grown on filter membrane of Transwell could be used to study drug transcellular transport by HPDLF and HGF in vitro.</p>

Biological transport of tetracycline hydrochloride by human periodontal ligament fibroblasts / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate biological transport of tetracycline hydrochloride by human periodontal ligament fibroblasts (HPDLF) for verifying the hypothesis of delivering medicine to the periodontium and whole body through the root canal.</p><p><b>METHODS</b>HPDLF and MC3T3-E1 cells were incubated in antibiotics solutions. The intracellular antibiotics contents were measured by high performance liquid chromatography (HPLC) and the cell total protein was measured by bradford protein assay.</p><p><b>RESULTS</b>The intracellular contents increased with incubation time. The extracellular medicine concentration had effect on the intracellular contents.</p><p><b>CONCLUSIONS</b>Tetracycline hydrochloride can be transported into HPDLF with incubation and this transport is time-dependent and concentration-dependent.</p>

Biological transport of minocycline by human periodontal ligament fibroblasts / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate biological transport of minocycline by human periodontal ligament fibroblasts (HPDLF). To verify the hypothesis of delivering medicine to periodontium and the whole body through the root canal.</p><p><b>METHODS</b>HPDLF and MC3T3-E1 cells were incubated in minocycline solutions. The intracellular antibiotics contents were measured by high performance liquid chromatography (HPLC) and the cell total protein was measured by Bradford protein assay.</p><p><b>RESULTS</b>HPLC was an accurate, sensitive method for measurement of the intracellular minocycline. The incubation time and cell property had significant effect on the intracellular minocycline contents (P< 0.01). The intracellular contents increased with extracellular concentration.</p><p><b>CONCLUSION</b>Minocycline can be transported by HPDLF. The transport is concentration-dependent, time-dependent and cell specific.</p>

Preliminary studies on histological changes after repairing the facial nerve defect with acellular facial nerve / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the morphological changes after chemically extracted acellular nerve allografts transplant.</p><p><b>METHODS</b>Seventy-two rabbits were divided into four groups. Acellular allografts of facial nerve were used in experimental group, and facial nerve autografts, acellular peroneal nerve allografts and peroneal nerve autografts respectively used in three control groups. The morphological changes after transplant were evaluated by modified trichrome staining, immunohistological staining and transmission electron microscope.</p><p><b>RESULTS</b>The two facial nerve grafts showed numerous regenerated nerve fibers, vessels and as well as a spindle schwann cells arranged longitudinally. No significant difference was observed in the fiber number and myelin thickness between the two groups,while the two peroneal nerve groups showed poor regeneration 6 months after operation.</p><p><b>CONCLUSIONS</b>The facial nerve allografts showed more neurite regeneration six months after transplant, and the regenerated axons passed through the distal stoma and there were well revascularized and proliferated schwann cells in the grafts.</p>