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Objective@#To evaluate the efficiency of maxillary expansion with clear aligners and to analyze the possible influence factors.@*Methods@#Thiry-one clear aligner cases (Invisalign) with maxillary expansion were enrolled in this study. The three-dimensional (3D) digital models of pre-treatment, planned in Clincheck software and post-treatment were collected. Upper dental arch width, buccal inclination of posterior teeth, and the expansion efficiency (expansion acquired/expansion planned) were measured and calculated. The impact of factors such as planned buccal inclination, planned expansion amount, attachment, and the mode of expansion on the expansion efficiency were analyzed.@*Results@#The increases of upper arch width in canine, 1st and 2nd premolar, 1st and 2nd molar were (2.0±1.3), (2.8±1.5), (3.0±1.4), (1.8±1.0) and 0.5 (0.1, 1.1) mm, with their efficiency of 68%, 70%, 68%, 55% and 29%, respectively. The posterior teeth showed significantly more buccal inclination than the planned position (P<0.05). However, the most buccally inclined tooth detected in 1st molars was only 3.1°±3.9°. When the planned inter-molar width increase was less than 2 mm (n=15), the expansion efficiency of premolars was higher compared with those cases with the planned inter-molar width increase more than 2 mm (n=16, P<0.05). The planned buccal inclination, attachments, and the expansion mode had no significant effect on the expansion efficiency (P>0.05).@*Conclusions@#The expansion of maxillary arch with clear aligners was achieved by the buccal movement of the posterior teeth with limited buccal inclination. The efficiency of expansion declines from 1st premolars to second molars. The planned inter-molar width had a significant influence on the efficiency of premolar expansion.
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<p><b>OBJECTIVE</b>To observe the role of the Hedgehog (Hh) genes in the proliferation of osteoblasts upon mechanical tensile strains.</p><p><b>METHODS</b>Primary osteoblasts harvested from newborn rat calvarial bone were subjected to 3% and 6% elongation of tensile stretches using Flexcell 4000 strain unit. The cultures were also treated with either recombinant N-terminals Sonic Hedgehog (N-Shh) or cyclopamine (cy), a Hh inhibitor or gadolinium (GdCl3), an inhibitor of stretch-activated channels. The proliferation of osteoblasts was quantified by cell counting, methyl thiazolyl tetrazolium (MTT) and cell cycle detection via flow cytometry. Statistical analysis was performed using SAS 8.0 software package.</p><p><b>RESULTS</b>The tensile strain, especially under 6% elongation, promoted osteoblast proliferation. Stretching force could also promote the proliferation even when the cells were treated with cy, but this effect was suppressed by GdCl3.</p><p><b>CONCLUSION</b>The induced proliferation of osteoblasts by mechanical stretched is mediated at least in part by Indian Hedgehog (Ihh) signaling.</p>
Subject(s)
Animals , Rats , Cell Proliferation , Hedgehog Proteins , Osteoblasts , Signal Transduction , Veratrum AlkaloidsABSTRACT
STGC3, a novel tumor related gene, was cloned recently. The previous studies indicated that STGC3 can inhibit the proliferation of CNE2 cell line in vitro. To examine the effect of STGC3 on the tumorigenicity of CNE2 cell line and explore its mechanism in nude mice. The Tet/pTRE/CNE2-STGC3 cell line was planted under the front leg skin of nude mice and induced by doxycycline (Dox). The mRNA and protein level of STGC3 in transplanted tumor tissues were detected with RT-PCR and Western Blotting. The apoptosis ratio of the tumor cell was analyzed with flow cytometry. STGC3, Bcl-2 and Bax proteins were examined by immunohistochemistry method. The results indicated that high level of STGC3 expression can inhibit tumorigenicity of CNE2 cell line in nude mice. Tumor grew slowly, later and smaller. Cell apoptotic percentage increased. Bcl-2 protein expression was down-regulated and Bax protein expression was up-regulated in Tet/pTRE/CNE2-STGC3 cell line (P
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Aim To investigate whether DATS induce MGC803 cell apoptosis and the relationship betweenapoptosis and Ca~(2+) disruption. Methods MGC-803 cell growth inhibition was measured by MTT assay. Tunnel and flow cytometry methods were used to determine the induction of apoptosis and Ca2+ homeostasis disruption. Result MTT assay showed that the inhibitory rates on MGC-803 cell growth of different concentrations of DATS 4,8,12,16 and 24 mg?L-1 were 0.231?0.037,0.305?0.036,0.455?0.029,0.607?0.058,0.751?0.019 respectively. Flow cytometry analysis showed that treating MGC803 cell with DATS significantly increased the percentage of apoptosis cells and intracellular Ca2+. Treatment of cells with 1,2-bis(2-aminophenoxye-thane)-N,N,N-tetraacetic acid tetrakis acetoxymethyl ester (BAPTA-AM), cellular Ca2+ chelator, resulted in abolishment of the elevation of intracellular Ca~(2+) and blockage of DATS induced apoptotic of MGC-803. Conclusoin DATS could induce apoptosis of MGC-803 cells through the mechanism of Ca~(2+) homeostasis disruption.
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AIM: To study the effects of norepinephrine preconditioning(NE-P) and ischemic preconditioning (IP)on apoptosis and Bcl-2, Bax expression in rat myocardial cells in myocardial ischemic reperfusion (I/R). METHODS: The model of rat ischemic-reperfusion was used to conduct NE-preconditioning. Apoptotic myocytes were detected with TUNEL. Bcl-2, Bax expression were detected with immunohistochemistry. RESULTS: The rate of apoptosis cells in I/R group was higher, the rate of apoptosis cells in NE-P group and IP was lower significantly than that in I/R group( P0.05). CONCLUSION: NE-P reduced myocyte apoptosis by I/R in rats; The expression of Bcl-2 ,Bax genes played an important role in myocardial apoptosis.