Neutrophils are involved in early bone formation during midpalatal expansion.

OBJECTIVE: Midpalatal expansion (MPE) is routinely employed to treat transverse maxillary arch deficiency. Neutrophils are indispensable for recruiting bone marrow stromal cells (BMSCs) at the initial stage of bone regeneration. This study aimed to explore whether neutrophils participate in MPE and how they function during bone formation under mechanical stretching. MATERIALS AND METHODS: The presence and phenotype of neutrophils in the midpalatal suture during expansion were detected by flow cytometry and immunofluorescence staining. The possible mechanism of neutrophil recruitment and polarization was explored in vitro by exposing vascular endothelial cells (VECs) to cyclic tensile strain. RESULTS: The number of neutrophils in the distracted suture peaked on Day 3, and N2-type neutrophils significantly increased on Day 5 after force application. The depletion of circulatory neutrophils reduced bone volume by 43.6% after 7-day expansion. The stretched VECs recruited neutrophils via a CXCR2 mechanism in vitro, which then promoted BMSC osteogenic differentiation through the VEGFA/VEGFR2 axis. Consistently, these neutrophils showed higher expression of canonical N2 phenotype genes, including CD206 and Arg1. CONCLUSIONS: These results suggested that neutrophils participated in early bone formation during MPE. Based on these findings, we propose that stretched VECs recruited and polarized neutrophils, which, in turn, induced BMSC osteogenic differentiation.

Matrix mechanics regulate the polarization state of bone marrow-derived neutrophils through the JAK1/STAT3 signaling pathway.

Matrix mechanics regulate essential cell behaviors through mechanotransduction, and as one of its most important elements, substrate stiffness was reported to regulate cell functions such as viability, communication, migration, and differentiation. Neutrophils (Neus) predominate the early inflammatory response and initiate regeneration. The activation of Neus can be regulated by physical cues; however, the functional alterations of Neus by substrate stiffness remain unknown, which is critical in determining the outcomes of engineered tissue mimics. Herein, a three-dimensional (3D) culture system made of hydrogels was developed to explore the effects of varying stiffnesses (1.5, 2.6, and 5.7 kPa) on the states of Neus. Neus showed better cell integrity and viability in the 3D system. Moreover, it was shown that the stiffer matrix tended to induce Neus toward an anti-inflammatory phenotype (N2) with less adhesion molecule expression, less reactive oxygen species (ROS) production, and more anti-inflammatory cytokine secretion. Additionally, the aortic ring assay indicated that Neus cultured in a stiffer matrix significantly increased vascular sprouting. RNA sequencing showed that a stiffer matrix could significantly activate JAK1/STAT3 signaling in Neus and the inhibition of JAK1 ablated the stiffness-dependent increase in the expression of CD182 (an N2 marker). Taken together, these results demonstrate that a stiffer matrix promotes Neus to shift to the N2 phenotype, which was regulated by JAK1/STAT3 pathway. This study lays the groundwork for further research on fabricating engineered tissue mimics, which may provide more treatment options for ischemic diseases and bone defects. STATEMENT OF SIGNIFICANCE.

A cone-beam computed tomographic study evaluating the efficacy of incisor movement with clear aligners: Assessment of incisor pure tipping, controlled tipping, translation, and torque.

INTRODUCTION: This retrospective clinical study aimed to evaluate the efficacy of different types of incisor movements with clear aligners in the sagittal plane. METHODS: Pretreatment and posttreatment cone-beam computed tomography (CBCT) scans were collected from 69 patients who underwent nonextraction treatment with clear aligners (Invisalign; Align Technology, San Jose, Calif). Integrated 3-dimensional models of the virtual incisor position (ClinCheck; Align Technology) and the posttreatment incisor position (from posttreatment CBCT scans) were superimposed over the pretreatment position (from pretreatment CBCT scans) using Mimics software (Materialise, Leuven, Belgium). On the basis of the location of the rotation center, incisors showing pure tipping (>10°), controlled tipping (>10°), translation (>1 mm), or torque (>10°) movements were selected. Efficacy was determined by comparing the predicted and achieved incisor movement, and differences with efficacy were analyzed using Kruskal-Wallis and Shapiro-Wilk tests (α = 0.05). RESULTS: In measurements for 231 incisors, the mean efficacy of incisor movements in the sagittal plane was 55.58%. The most and least predictable movements were pure tipping (72.48%) and torque (35.21%), respectively. Labial root movement was significantly more predictable than lingual root movement, and labial movement of the mandibular incisors was significantly easier than that of the maxillary incisors. The type of tooth movement achieved was different from the type designed. CONCLUSIONS: The efficacy of incisor movement in the sagittal plane using clear aligners varies with designed movement type, and labial root movement appears to be more accurate than the lingual root movement. The biomechanics of clear aligners remains to be further elucidated to achieve more predictable treatment results.

How well do integrated 3D models predict alveolar defects after treatment with clear aligners?

OBJECTIVES: To evaluate the accuracy of integrated models (IMs) constructed by pretreatment cone-beam computed tomography (pre-CBCT) in diagnosing alveolar defects after treatment with clear aligners. MATERIALS AND METHODS: Pre-CBCT and posttreatment cone-beam computed tomography (CBCT) scans from 69 patients who completed nonextraction treatment with clear aligners were collected. The IMs comprised anterior teeth in predicted positions and alveolar bone from pre-CBCT scans. The accuracy of the IMs for identifying dehiscences or fenestrations was evaluated by comparing the means of the defect volumes, absolute mean differences, and Pearson correlation coefficients with those measured from post-CBCT scans. Defect prediction accuracy was assessed by sensitivity, specificity, positive predictive values, and negative predictive values. Factors possibly affecting changes in mandibular alveolar defects were analyzed using a mixed linear model. RESULTS: The IM measurements showed mean deviations of 2.82 ± 9.99 mm3 for fenestrations and 3.67 ± 9.93 mm3 for dehiscences. The absolute mean differences were 4.50 ± 9.35 mm3 for fenestrations and 5.17 ± 9.24 mm3 for dehiscences. The specificities of the IMs were higher than 0.8, whereas the sensitivities were both lower (fenestration = 0.41; dehiscence = 0.53). The positive predictive values were unacceptable (fenestration = 0.52; dehiscence = 0.62), and the overall reliability was low (<0.80). Molar distalization and proclination were positively correlated with significant increases in alveolar defects at the mandibular incisors after treatment. CONCLUSIONS: Alveolar defects after clear aligner treatment cannot be simulated accurately by IMs constructed from pre-CBCT. Caution should be taken in the treatment of crowding with proclination and molar distalization for the safety of alveolar bone at the mandibular incisors.

Clear aligners for maxillary anterior en masse retraction: a 3D finite element study.

To evaluate tooth behaviours under various maxillary incisor retraction protocols for clear aligner therapy. A three-dimensional finite element model of maxillary dentition was constructed for first premolar extraction. A loading method was developed to mimic the mode of action of clear aligners for incisor en masse retraction. Three protocols with different amounts of retraction and intrusion on incisors were designed. Initial tooth displacements and stresses on periodontal ligaments were analysed with ANSYS software. The central (U1) and lateral (U2) incisors exhibited uncontrolled lingual tipping and extrusion upon 0.25 mm retraction. U1 exhibited translation movement, while U2 underwent less tipping during 0.2 mm retraction and 0.15 mm intrusion. Labial tipping and intrusion of U1 and bodily intrusion of U2 were observed during 0.1 mm of retraction and 0.23 mm of intrusion. With the additional intrusion on incisors, canine showed extrusion movement, and higher stresses on periodontal ligaments were shifted from U2 to canines. Incisors also exhibited different mesial-distal angulation in the three simulations, while posterior teeth all suffered mesial inclination. Incorporating intrusion displacement in clear aligners led to a tendency of lingual root movement during incisor retraction. The complexity of tooth movement should be recognized regarding clear aligner therapy.

[Protective effect and immune mechanism of berberine on cerebral ischemia/reperfusion injury in rats].

Objective: To investigate the protective effect and immune mechanism of berberine on cerebral ischemia/reperfusion injury in rats. Methods: Fifty SD rats were randomly divided into sham operation group (Sham), model group (Model), berberine low dose groups (BBR-L, 25 mg/kg), berberine medium dose groups (BBR-M, 50 mg/kg) and berberine high dose groups (BBR-H, 100 mg/kg), with 10 rats in each group. Longa suture method was used to establish a rat model of cerebral ischemia/reperfusion, after 2 hours of ischemia, reperfusion for 24 hours. Rats in BBR-L, BBR-M and BBR-H were treated with berbrerine by gavage 2 hours after successful model building, while the sham operation group and the modle group were given the same volume of saline as described above. After 24 hours of administration, the activity of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), cytokine tumor necrosis factor α (TNF-α) , interferon ß (IFN-ß) , interleukin 6 (IL-6) and nitric oxide (NO) content were detected by ELISA assay. Serum CD4+, CD8+ and CD4+/CD8+ contents were measured by flow cytometry to investigate the immune function of each group. RT-qPCR and Western blot were used to detect NF-kappaB-NOD-like receptors 3 (NF-κB-NLRP3) signal axis key genes and protein expression in rat brain tissue. Results: Compared with the sham operation group, the degree of neurological deficit and the rate of cerebral infarction were increased in the model group (P＜0.05), and the levels of serum NO, TNF-α, IFN-ß, IL-6, NF-κB p65, NLRP3, ASC and caspase-1 in brain tissue were increased (P＜0.05), while the activities of SOD, GSH-Px and the levels of CD4+, CD8+ and CD4+/CD8+ in serum were decreased (P＜0.05). Compared with the model group, the degree of neurological deficit and the rate of cerebral infarction were increased in the BBR-H, BBR-M and BBR-L groups (P＜0.05), and the levels of serum NO, TNF-α, IFN-ß, IL-6, NF-κB p65, NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1 in brain tissue were increased (P＜0.05), while the activities of SOD, GSH-Px and the levels of CD4+, CD8+ and CD4+/CD8+ in serum were decreased (P＜0.05). Conclusion: Berberine may reduce oxidative stress, inhibit inflammation, enhance immune function, and reduce cerebral ischemia/reperfusion injury in rats, which may be related to the inhibition of NF-κB-NLRP3 signaling.

Tension-loaded bone marrow stromal cells potentiate the paracrine osteogenic signaling of co-cultured vascular endothelial cells.

Co-culture of bone marrow stromal cells (BMSCs) and vascular endothelial cells (VECs) is a promising strategy for better osteogenesis and pre-vascularization in bone tissue engineering. Recent reports have shown that mechanical stretching further promotes osteogenesis in BMSC/VEC co-culture systems, but the underlying mechanism of this process remains unclear. In this study, noncontact co-cultures of rat primary BMSCs and VECs were employed to interrogate paracrine cell-to-cell communications in response to tension. Exposure of VECs to 6% tension for 48 h elicited neither ALP activity nor mRNA expression of OCN and OPN in BMSCs incubated in a shared culture medium. Instead, BMSCs subjected to tension induced robust VEGF release, and its conditioned medium enhanced the proliferation and tubular formation of VECs with a concurrent increase in BMP-2 and IGF-1 production. Conditioned medium from activated VECs in turn promoted expression of osteogenic genes in BMSCs, followed by an increase in matrix mineralization. The addition of VEGF-R inhibitor Tivozanib to these systems abrogated the tension-induced paracrine effects on VECs and subsequently impaired BMSC osteogenesis. These results clearly demonstrate that the response of BMSCs to tension potentiates paracrine osteogenic signaling from VECs; this positive feedback loop is initiated by VEGF release.

[The impact of personality traits on adolescents' adaptation and compliance to clear retainers].

PURPOSE: The aim of this study was to evaluate the adolescents' adaptation and compliance to clear retainers, and to investigate their associations with personality traits. METHODS: Fifty adolescents at the end of fixed orthodontic treatment were consecutively recruited. After debonding the fixed orthodontic appliances, clear retainers were used. Participants were asked to fill questionnaires 2 months after wearing the clear retainers. A questionnaire was designed to evaluate their adaptation and compliance for clear retianers. Eysenck personality questionnaire was used to assess the personality traits. Spearman rank correlation was used to analyze the associations between personality traits with the adaptation and compliance to clear retainers using SAS8.0 software package. RESULTS: Forty-two of 50 adolescents accomplished the questionnaires. 76% felt no mucous irritation, 95% felt no influence on socializing. However, 75% showed oral constraint, 71% felt impaired speech. Moreover, 40% adolescents wore the retainers less than 18 hours per day. 31% patients had their aligner lost. 83% patients did not brush their teeth after each meal. Neuroticism was positively associated with the effect of impaired chewing (r=0.32). Psychoticism was positively associated with the oral constraint (r=0.31) and facial muscular soreness (r=0.35), but negatively associated with the influence on emotion (r=-0.34). Extraversion was positively associated with the retainers' damage (r=0.31). CONCLUSIONS: Adolescents showed good adaptation for clear retainers, but unsatisfactory compliance. There are associations between adolescents' adaptation and compliance for clear retainers and personality traits. These results suggest that clinicians should pay more attention to the compliance of adolescents when using clear retainer. Personality traits could be a useful prediction to assess the compliance for clear aligners.

[The Association Between Serum Uric Acid and Creatinine in Patients with Hypothyroidism].

OBJECTIVE: To determine the relationship between serum uric acid (SUA) and creatinine (SCr) in patients with hypothyroidism. METHODS: A total of 2 078 people who took physical examinations in the West China Hospital, Sichuan University in May 2014 participated in this study. Serum thyrotropin (TSH), free thyroxine (FT4) and free triiodothyronine (FT3) were detected by electrochemiluminescence. SUA was measured using uricase UV method. The participants were divided into three groups according to their thyroid function: hypothyroidism, subclinical hypothyroidism (SCH) and control. The prevalence of hyperuricemia in each group was Estimated. Correlation analyses were performed for the serum indicators. RESULTS: There were 1 685 participants in the control group, 38 in the hypothyroidism group, and 355 in the subclinical hypothyroidism group. Hypothyroidism patients had significantly higher levels of TSH than those in the control and SCH groups. Significant differences in serum levels of FT3 and FT4 were found between the three groups. Higher levels of SCr (P=0. 005) and SUA (P=0. 008) were also found in hypothyroidism patients compared with those in the control and SCH groups. In those younger than 60 years, men were more likely to catch hyperuricemia than women, with 50-59 year old men having the highest prevalence of hyperuricemia. Higher prevalence of hyperuricemia in men (compared to women) was also found in those older than 60 years, but without statistical significance (P=0. 09). After correcting for gender, TSH showed no correlations with SUA (r=-0. 01, P=0. 648) and SCr (r=-0. 02, P=0. 284); FT4 showed negative correlations with SUA (r= -0. 978, P=0. 001) and SCr (r= -0. 599, P= 5. 012); FT3 showed negative correlations with SUA (r= -0. 745, P=0. 007) and SCr (r -0. 457, P=0. 034). CONCLUSION: Reduced thyroid hormone levels may lead to elevated SCr levels. And elevated SCr levels may be issociated with elevated levels of SUA in patients with hypothyroidism.

[Effect of Serum Uric Acid on Renal Function of Patients with Abnormal Glucose Metabolism].

OBJECTIVE: To determine the effect of serum uric acid on renal function of patients with abnormal glucose metabolism. METHODS: A total of 1 495 people who took physical examinations in West China Hospital of Sichuan University in May 2014 were recruited in this study. Serum nitrogen (BUN), creatinine (SCr), triglycerides (TG), cholesterol (TC), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C) and uric acid (SUA) of the participants were detected by an automatic biochemical analyzer. The glomerular filtration rate, (eGFR) was calculated with CKD-EPI. According to hyperuriceima (HUA), the participants were divided into groups with impaired fasting glucose (IFG), diabetes (DM), IFG with hyperuicimia, and DM with hyperuricemia. The participants with normal fasting plasma glucose served as controls. Renal dysfunction was detected using eGFR≤50 mL/(min . 1. 73 m2) and SCr≤1. 7 µg/mL. RESULTS: About 13. 18% (197/1 495) participants were identified as IFG with HUA: male (158)/female (39) ratio =4.05; 4.41% (66/1 495) as DM with HUA: male (58)/female (8) ratio = 7. 25. Participants with HUA in the control, IFG and DM groups had higher levels of BUN and SCr and lower levels of eGFR than those without HUA (P<0. 05). HUA was more likely to be associated with serum. lipid in the control and IFG groups (most P<0. 05) than in the DM group (P>0. 05). DM patients without HUA had better renal function and serum lipid levels than those who had HUA in their early stage of abnormal glucose metabolism (IFG with HUA) (P<0. 05). The prevalence of renal dysfunction of IFG patients with HUA was significantly higher than those without HUA, similar to the prevalence of renal dysfunction of DM patients with HIUA (P

[Clinical effect of premolar extraction with high torque self-locking appliances].

PURPOSE: To analyze the clinical effect of extraction correction of patients with maxillary protrusion by using Damon high torque appliances. METHODS: Forty patients with extraction of four first premolars due to orthodontic treatment were selected. They had protrusion of maxilla and were randomly divided into two groups. Both arches of Damon group were treated with Damon high torque appliances and MBT group were corrected with traditional MBT straight wire appliance; patients in two groups received sliding mechanics for adduction of upper anterior teeth. Cephalometric radiophotographs were analyzed before（T0）and after adduction of upper anterior teeth（T1）. The difference between the two groups was analyzed with SPSS15.0 software package. RESULTS: The upper incisors showed a more retruded position in the two groups at T1,although they showed a similar amount in both groups. The backward movement of upper lip was 2.31mm in Damon group, which was significantly less than that of 2.81mm in MBT group(P<0.05). No significant difference in the first molar mesialization was detected between Damon group(2.33 mm) and MBT group(2.36mm) (P>0.05). For anterior teeth retraction, nasolabial angle (NLA) in MBT and Damon group were 107.44°and 106.33°, increase of NLA in MBT group was 9.17°,which was significantly larger than that of 7.22°in Damon group (P<0.05). U1-MxP in MBT and Damon were 110.61°and 114.11°. U1-MxP decreased 12.06°in MBT group, while significant change was deteced in Damon group of 7.61°(P<0.05). CONCLUSIONS: Application of Damon high torque appliances in extraction treatment of maxillary protrusion patients yielded better control of the labial crown torque of anterior teeth, and avoided excessive lingual inclination of anterior teeth compared with MBT in adduction of upper anterior teeth.

[A clinical evaluation on the stability of orthodontic mini-implants using resonance frequency analysis].

PURPOSE: To evaluate the stability of mini-implant by resonance frequency analysis and to determine the optimal loading timing of orthodontic force. METHODS: Fourteen orthodontic patients who had upper first premolars extraction and needed mini-implants to reinforce the anchorage were enrolled in this study. The patients were divided into 2 groups: delay-loading group and selective-loading group. A joined head mini-implant was inserted in the buccal interradicular area on each side of maxilla for each patient and 28 mini-implants in total were used. Osstell resonance frequency device was used to measure the ISQ (implant stability quotients) value. The measurements were performed immediately after the implant insertion and weekly afterwards until week 16. After the ISQ value was stable, orthodontic force of 150g was loaded on the mini-implants in selective-loading group. The same level of force was applied in delay-loading group at week 12. The data was analyzed by one-way ANOVA and t test using SPSS 19.0 software package. RESULTS: Twenty-three mini-implants were stable during the study. Twelve unloading mini-implants in delay-loading group showed maximal ISQ values immediately after insertion and at week 1 (21.48 ± 5.25). The ISQ values decreased gradually from week 2 to week 5 and reached a plateau after week 6 (11.26 ± 3.36). Eleven mini-implants survived in selective-loading group were then loaded at week 6. There were no significant differences of ISQ values in loading and unloading mini-implants after 6 weeks. The remaining 5 mini-implants were loosing during the first 4 weeks, which showed a significant lower initial ISQ values compared to the successful implants. CONCLUSIONS: The stability of mini-implants decreases 1 week after insertion and maintains after 6 weeks. Orthodontic loading after week 6 has no influence on the stability. Lower initial stability is an important factor for the failure of mini-implants.

[Osteoclasts and early bone remodeling after orthodontic micro-implant placement].

PURPOSE: To observe the incidence of osteoclasts during early bone remodeling after orthodontic micro-implant placement. METHODS: Twenty New Zealand rabbits were randomly allotted into 4 groups. One micro-implant was implanted proximal to the epiphyseal plate of the tibia. Animals were sacrificed on day 3, 7, 14 and 28 (n=5). The sequence of histological changes around the micro-implants were evaluated by hematoxylin and eosin (HE) staining. Osteoclasts were identified by TRAP staining. The differences of the number of the osteoclasts among each time point were analyzed by one way ANOVA with SPSS 19.0 software package. RESULTS: After 3 days of implantation, a large number of erythrocytes, inflammatory cells, mesenchymal cells and bone debris were seen at the implant bone interfaces. Few osteoclasts were observed. On day 7, granular woven bone was formed and some osteoclasts were found in the Howship's lacunae. New bone formation and mineralization were apparent on day 14. Meanwhile, large amounts of osteoclasts were found in the latticed woven bone. On day 28, woven trabeculae with lamellate structures connected to lamellar bone and fewer osteoclasts were identified. Semi-quantitative analysis showed that the number of the osteoclasts was at peak on day 14. There were significant differences among each time point (P<0.01). CONCLUSIONS: Osteoclast activity is closely related to bone formation and remodeling after micro-implant insertion.

Effects of lithium on extraction socket healing in rats assessed with micro-computed tomography.

OBJECTIVE: Lithium is an activator of ß-catenin signaling and ß-catenin plays an important role in regulating bone formation and remodeling. The purpose of this study was to investigate the effects of lithium on bone repair in tooth extraction sockets in rats. MATERIAL AND METHODS: Twenty male Wistar rats were subjected to maxillary left second molar extraction. The animals received a daily injection of lithium chloride (LiCl) or the same dose of sodium chloride (NaCl) starting 7 days before tooth extraction until sacrifice 14 days after extraction. Rats were randomly divided into: (1) a pre-treated group that received LiCl injection from 7 days before to 3 days after tooth extraction; (2) a post-treated group that received LiCl injection starting 4 days after tooth extraction; (3) a continuously treated group that received LiCl injection for the entire 21 days; and (4) a control group that received NaCl injection only. The volume of new bone and the bone density in the extraction socket were quantified by micro-computed tomography. RESULTS: The percentage of new bone formation in the extraction socket was as follows: 63.2 ± 13.4% (pre-treated group), 53.9 ± 9.8% (post-treated), 23.8 ± 8.0% (continuously treated) and 37.5 ± 4.2% (control). The difference in percentage was statistically significant between each pair of groups. Pre- and post-treated groups also showed a significant increase in the density of new bone. CONCLUSIONS: Lithium enhances bone repair in extraction sockets when delivered before or after tooth extraction. Tooth extraction during lithium treatment may impair bone healing.

Effects of tensile forces on serum deprivation-induced osteoblast apoptosis: expression analysis of caspases, Bcl-2, and Bax.

BACKGROUND: Apoptosis is involved in the adaptive responses of bone to mechanical loading. The purpose of this study was to investigate the effects of tensile forces on osteoblast apoptosis and the related mechanism by analyzing the expression of caspases, Bcl-2, and Bax. METHODS: Primary osteoblasts were harvested from neonatal rat calvaria and were subjected to cyclic tensile forces for 72 hours using Flexcell 4000 strain unit in Minimum Essential Medium (MEM) with 10% fetal calf serum (FCS) or with serum deprivation. Apoptosis was tested by flow cytometry using annexin V/PI staining. Caspase-3 activity was analyzed via Elisa. The gene expression of caspase-8, -9, Bcl-2, and Bax was quantified by reverse transcription (RT)-PCR. RESULTS: In 10% FCS condition, no significant difference in cell apoptosis was found between the stretched and non-stretched osteoblast cultures. Serum withdrawal resulted in higher apoptosis rate in the osteoblasts with increased caspase-3 activity, and elevated expression of caspase-9 and Bax. Six-percent elongation of stretch attenuated the cell apoptosis induced by serum starvation, concurrent with a decrease in caspase-3 activity, a decline of caspase-8 expression, and an elevation of Bcl-2 level. On the contrary, 12% elongation of stretch increased caspase-3 activity and promoted the apoptosis with an elevated expression of caspase-8 and Bax. No significant change of caspase-9 expression was identified upon force application. CONCLUSIONS: These results suggested that tensile forces regulate cell apoptosis of primary rat osteoblasts through caspase-3 and caspase-8 signaling cascade. Light forces rescue the cells from serum deprivation-induced apoptosis by elevating Bcl-2 expression, while heavy forces promote the apoptotic insult by inducing Bax expression.

[Centrographic analysis in Shanghai adults with normal occlusion].

PURPOSE: To obtain the reference value of centrographic analysis of Shanghai adults with normal occlusion. METHODS: Seventy five subjects of Han nationality at permanent dentition with normal occlusion were selected from Shanghai region (34 males, 41 females, age rang:18-21 years). Centrographic analysis was conducted on the basis of the lateral cephalograms, and the obtained data was compared with that of Caucasian. SAS9.2 software package was used for statistical analysis. RESULTS: The reference value of centrographic analysis in Shanghai adults with normal occlusion was established. The facial centroid was located on the Ba-A plane; the upper centroid was positioned on the centroid plane; the lower centroid was positioned anterior to the centroid plane within 0.92-1.29mm; the long axis of lower incisor was positioned posterior to 1/3 Ba-Gn plane symphysis intersection; the long axis of upper incisor was positioned posterior to orbitale and the upper incisor was positioned in proper occlusion with the lower incisor. The lips were positioned on the outer profile plane. There was no significant difference between male and female adults (P>0.05). CONCLUSIONS: Compared with that of Caucasians, mandibular position of adults in Shanghai was in a relative forward position, the incisor was labially inclined and the soft tissue in the lower 1/3 of the face was convex slightly.

[Correlation of CpG methylation status of Runx3 with pathogenesis of gastric carcinoma].

OBJECTIVE: To investigate the role of Runx3 gene CpG island methylation in the development of human gastric carcinoma. METHODS: A total of 150 tumor specimens from patients with gastric carcinoma and 50 normal tissue specimens were selected. Methylation specific PCR (MSP) and pyrosequencing (PS) were used to detect the methylation status of Runx3 gene promoter. RESULTS: Compared to normal tissue samples, a significant increase of CpG island methylation status of Runx3 gene was observed in gastric carcinomas (MSP: 67.3% vs. 40.0%, P = 0.002; PS: 76.0% vs. 30.0%, P < 0.01). Runx3 gene methylation was only related to tumor size (P < 0.05) based on MSP analysis. PS test however showed that the extent of methylation of Runx3 gene was related to the tumor size (P = 0.004), Lauren's classification (P = 0.043), depth of invasion (P < 0.01), lymph node metastasis (P = 0.021) and TNM staging (P = 0.045). CONCLUSIONS: Methylation status of Runx3 gene detectable by PS is closely correlated with clinicopathological parameters of gastric carcinoma, including tumor size, Lauren's classification, depth of invasion, lymph node metastasis and TNM staging. PS is more sensitive than MSP in the detection of Runx3 gene methylation, which may serve as an important marker for early diagnosis and treatment of gastric carcinoma.

STGC3 inhibits xenograft tumor growth of nasopharyngeal carcinoma cells by altering the expression of proteins associated with apoptosis.

STGC3 is a potential tumor suppressor that inhibits the growth of the nasopharyngeal carcinoma cell line CNE2; the expression of this protein is reduced in nasopharyngeal carcinoma compared with normal nasopharyngeal tissue. In this study, we investigated the tumor-suppressing activity of STGC3 in nude mice injected subcutaneously with Tet/pTRE-STGC3/CNE2 cells. STGC3 expression was induced by the intraperitoneal injection of doxycycline (Dox). The volume mean of Tet/pTRE-STGC3/CNE2+Dox xenografts was smaller than that of Tet/pTRE/CNE2+Dox xenografts. In addition, Tet/pTRE-STGC3/CNE2+Dox xenografts showed an increase in the percentage of apoptotic cells, a decrease in Bcl-2 protein expression and an increase in Bax protein expression. A proteomic approach was used to assess the protein expression profile associated with STGC3-mediated apoptosis. Western blotting confirmed the differential up-regulation of prohibitin seen in proteomic analysis. These results indicate that overexpression of STGC3 inhibits xenograft growth in nude mice by enhancing apoptotic cell death through altered expression of apoptosis-related proteins such as Bcl-2, Bax and prohibitin. These data contribute to our understanding of the function of STGC3 in human nasopharyngeal carcinoma and provide new clues for investigating other STGC3-associated tumors.