BACKGROUND:Low concentration of nicotine promotes the angiogenesis and facilitates the healing of skin wounds. However, the role of low concentration of nicotine on the repair of maxil ofacial soft tissue trauma especial y oral mucosa stil remains unclear
OBJECTIVE:To evaluate the effect of low concentration of nicotine on mucosa defect repair of rat hard palate.
METHODS:A circular soft tissue defect at 3 mm diameter was produced in the centre of hard palate of 65 Wistar rats. After the operation, animals were randomly divided into low concentration of nicotine with gel group, gel group and control group. Rats were sacrificed at 3, 7, 10 and 14 days post-surgery. The wound healing was detected with hematoxylin-eosin staining and the difference of wound healing in different groups was compared with gross observation and image measurement.
RESULTS AND CONCLUSION:There was no significant difference in the wound healing in different groups on day 3 post-surgery. On days 7 and 10, the group of low concentrations of nicotine with gel was faster than gel group and control group (P<0.05);the wounds were completely healed on day 14, with no significant difference among the groups. Low concentrations of nicotine may promote the mucosa defects repair of rat hard palate.

Objective Streptococcus sanguis is a possible candidate bacterium for the caries replacement therapy, which has no advantages in the acidic environment.The aim of the study was to construct acid-resistant strains of Streptococcus sanguis, determine its acid tolerance, and explore the mechanism of its antagonism against Sterptococcus mutans.Methods By gradually reducing the pH value of the medium, we constructed acid-resistant strains of Streptococcus sanguis, observed their growth and measured their acid tolerance according to their survival rate against lethal pH.We evaluated the competitive relationship between Streptococcus sanguis and Streptococcus mutans by plate experiment and detected the changes of related acid resistance genes by real-time quantitative PCR.Results The growth of Streptococcus sanguis and its acid-resistant strains were limited by the pH value, and that of Streptococcus sanguis was better in either acidic or normal environment.The lethal pH value of Streptococcus sanguis was 3.6, that of its acid-resistant strains was 2.3, and the survival rate of the acid-resistant strains was 66.59% in the pH 3.6 environment.In comparison, the lethal pH value of Streptococcus mutans was 2.5, that of its acid-resistant strains was 2.1, and the survival rate of the acid-resistant strains was 2.55% in the pH 2.5 environment.In the presence of chloramphenicol, the acid-resistant strains could not survive in the original lethal pH.In the sub-lethal pH environment, the expressions of the acid resistance-related genes Groel and Dnak in the acid-resistant strains were significantly up-regulated as compared with those in the original Streptococcus sanguis (P<0.05).Conclusion Streptococcus sanguis has an acid adaptability and can enhance acid resistance in the sub-lethal pH environment.Acid-resistant Streptococcus sanguis in the replacement therapy may provide some new ideas for the treatment of dental caries.

Objective Antimicrobial peptides are the focus of recent research in oral microbiology .This study aimed to eval-uate the activity of a novel antimicrobial peptide pm 11 against oral microorganisms and its action mechanisms . Methods We ana-lyzed the effect of pm11 on oral microorganisms and determined its antimicrobial activity in the saliva environment by measuring its min -imal inhibitory concentration (MIC), minimal bactericide concentration (MBC), and bactericidal kinetics.We observed its bacteri-cidal activity on the biofilms of streptococcus mutans by confocal laser scanning microscopy (CLSM) and the structural changes in the bacterial membrane by scanning electron microscopy (SEM). Results The antimicrobial activity of pm11 varied greatly against dif-ferent oral microorganisms , with its MIC values ranging from 2 μg/mL to 256 μg/mL and its MBC values from 2 μg/mL to >256μg/mL.The bactericidal kinetics showed a decreasing survival rate of bacteria with the lengthening of the intervention time .The inhib-itory-zone diameters exhibited no significant indifference between the water solution and the sterile saliva solution .CLSM revealed an increased number of dead bacteria in the pm 11-treated biofilms , while SEM manifested obvious changes in the shape of the bacteria membrane treated with pm11. Conclusion Our findings suggest that pm11 has a broad spectrum of antimicrobial activities on oral mi-croorganisms and a potential value of clinical application .

Objective To investigate the effects of angelica solution on chronic hypoxic pulmonary hypertension in rats.Methods Thirty SD rats were randomized into normoxic group,hypoxic group and angelica solution-protected group.The model of rat chronic hypoxic pulmonary hypertension was made by method of isobaric hypoxia.Angelica solution were injected before hypoxia,while the other two groups were injected normal saline.After 28d of hypoxia,pulmonary artery pressure were measured.Expressions of proliferating cell nuclear antigen (PCNA) and inducible nitric oxide synthase (iNOS) in pulmonary artery were detected by immunohistochemical staining.The index of wall thickness of rat pulmonary arteriole-percentage of the wall area in the total vascular area(wA%) were measured by a computerized image analyzer.Results The mean pulmonary artery pressure (mPAP) of normoxic group,hypoxic group and angelica solution-protected group were10.50±1.90,35.36±9.11,18.32±2.30 (mm Hg);wA% of the three groups were 52.71±5.16,82.38±8.43,64.58±9.54 (%),mPAP and wA% were significantly higher in the hypoxic group than those in the normoxic group (P<0.01) and angelica solution-protected group (P<0.01).PCNA expression of normoxic group,hypoxic group and angelica solution-protected group were 3.15±1.10,24.50±5.72,12.67±3.46 (%).The PCNA expression in the pulmonary artery was significantly higher in the hypoxic group than those in the normoxic group (P<0.01) and in the angelica solution-protected group (P<0.01).iNOS expression of normoxic group,hypoxic group and angelica solution-protected group were 2.13±1.01,17.33±3.53,37.50±7.04 (%).iNOS expression in the pulmonary artery was higher in the hypoxic group than those in normoxic group (P<0.01),and angelica significantly increased iNOS expression in comparison with the normoxic and hypoxic groups (P<0.01).Conclusion Angelica solution alleviates chronically hypoxia induced pulmonary hypertension in rats by inhibiting the espression of PCNA in pulmonary artery and up-regulating the expression of iNOS.

[Abstract ] Objective More and more researches demonstrate that epithelial-mesenchymal transition(EMT) is highly rele-vant to cancer metastasis , tissue fibrosis and skin wound healing , but its role in the wound healing of oral mucosa still needs further ex-ploration.This study was designed to discuss the effects of EMT on the wound healing of lingual mucous membrane in rats . Methods A 3mm-diameter circular defect was made on the mucosa of lingual dorsum in 8-week-old Wistar rats.The rats were put to death at day 0, 1, 2, 3, 4 and 8 after operation.We observed tissue healing process by HE staining and used immunohistochemical fluorescence to detect the expressions of EMT-related protein E-cadherin(E-cad), Vimentin and Fibroblast specific proteins (FSP1) in lingual mucous membrane during wound healing . Results The expressions of E-cad at the edge of the wound in the lingual mucous membrane of rats at day 2 and 4 after operation were less than those at day 0 and 1 after operation , while interstitial cell specific protein Vimentin and FSP1 were positively expressed in the epidermal basal layer .The wound of lingual mucous membrane healed completely at day 8 after operation , and E-cad expression was close to that at day 0 after operation .A small amount of Vimentin and FSP 1 expressed in the epi-thelial basal layer . Conclusion E-cad, Vimentin, FSP1 are involved in the wound healing process of lingual mucous membrane . During the wound healing in the tongue mucous membrane of rats , some epithelial cells gain the feature of mesenchymal cells in the process of migration to wound centre .EMT has played an important role during wound healing of lingual mucous membrane in rats .

Objective: This work aimed to investigate the relationships of the serum levels of IL-17 and TGF-β with the carcinogenesis and progression of colorectal cancer (CRC), as well as the clinical significance of these serum levels. Methods: Data of 30 healthy subjects, 59 patients with simple CRC and 44 CRC patients with postoperative (post-op) metastasis were recruited in this study. The patients were respectively divided into group A (30 healthy subjects as the control group), group B (59 CRC patients without distant metastasis after surgery), and group C (44 CRC patients with post-op metastasis). The patients in each group had a mean age of 53.8 ± 20.8, 62.0 ± 11.8, and 64.0 ± 15.7 years, respectively. All patients were confirmed by pathological diagnosis. The serum levels of IL-17 and TGF-β were measured by enzyme-linked immunosorbent assay. All quantitative data were analyzed using SPSS 13.0. Results: The IL-17 serum level was significantly higher in groups B and C than in group A. The preoperative (pre-op) serum level of IL-17 was significantly higher than the post-op serum level in group B (P<0.05). No significant difference was observed in the TGF-β serum levels between groups A and B, as well as between the pre-op and post-op serum levels in group B (P>0.05). However, the TGF-β serum level in group C was significantly higher than that in groups A and B (P<0.05). No significant correlation was observed in the serum level IL-17 or TGF-β between colon and rectum cancers in groups B and C. Conclusion: The serum level of IL-17 is significantly correlated with that of CRC. The serum level IL-17 increases with the aggravation of CRC and increased tumor burden. A strong correlation exists between the serum level of TGF-β and metastasis of CRC. Cytokine IL-17 and TGF-β may play an important role in the progression and metastasis of CRC.

AIM: To study the effects of fibroblast growth factor 8 (FGF8) on directional differentiation of human dental pulp stem cells (hDPSCs) into odontoblasts and pulp tissue.METHODS: hDPSCs were isolated and cultured, and identified with flow cytometry by detecting cell surface markers of hDPSCs.FGF8 at concentration of 50 μg/L was added into the mineralization fluid to induce the differentiation of the hDPSCs.The mRNA expression of dentin sialophosphoprotein (DSPP), alkaline phosphatase (ALP), bone sialoprotein (BSP) and core-binding factor alpha 1 (Cbfa-1) in differentiated cells was detected by real-time PCR.FGF8 and mouse E11.5 dental epithelium formed restructuring cell group with hDPSCs, and then the restructuring cell group was transplanted under renal capsule membrane in nude mice for tissue culture.DNA in situ hybridization was used to identify the sources of odontoblasts and pulp cells.RESULTS: The surface markers of CD29 and CD90 showed positive in isolated hDPSCs.FGF8 induced hDPSCs to form a distinct mineralization nodule, and the expression of dentin-specific proteins, DSPP, BSP and Cbfa-1, was increased.hDPSCs were induced to differentiate into odontoblasts and pulp cells by E11.5 dental epithelium and FGF8.CONCLUSION: FGF8 can assist dental epithelium to induce directional differetiation of hDPSCs into odontoblasts and pulp cells, and formation of dentin and dental pulp cavity structure.

Cracked tooth is a common type of tooth fracture with diverse symptoms, different treatment principles and unpredictable prognosis. The available remedies for immediate, intermediate and definitive managements include occlusal adjustment, orthodontic band, bonded composite resin, onlay, full crown and so on. For teeth with localized crack and vital pulp, bonded composite resin and onlay with cuspal coverage are also protective remedies besides traditional full-crown restoration. Once pulpal infection occurs, root canal therapy and full-crown restoration is indicated. Clinical determination should be made with comprehensive consideration of the location and depth of the crack, risk of extension and pulpal condition. This review will focus on the traits and prognosis of various therapy options, so as to provide evidence-based treatment planning of cracked tooth.

Objective To assess the diagnostic value of magnetization transfer MRI (MTI) for bowel inflammation and fibrosis in humans with Crohn disease (CD). Methods From July 2014 through April 2017, 31 patients with a confirmed diagnosis of CD were prospectively recruited from the First Affiliated Hospital of Sun Yat Sen University. They were scheduled for elective surgery due to bowel obstruction and other complications, and underwent preoperative MR enterography (MRE) and MTI within 15 days of surgery. All cases had available intestinal specimens identified on MRE and resected bowel segments for region by region matching. All patients underwent breath hold conventional MRE and MTI examinations, and then the magnetization transfer ratios (MTRs) of pathological bowel segments were measured. Using region by region correlation between MTI and surgical specimen, the bowel segments were resected to stain with HE for evaluating bowel inflammation, Masson for bowel fibrosis, and typeⅠcollagen staining for the deposition of typeⅠcollagen within the bowel walls. The histologic sections from the most severe areas were scored as 0 (normal), 1 (mild), 2 (moderate) and 3 (severe). The correlations between MTR and histologic scores were analyzed by using Spearman rank correlation or partial correlation. The differences in MTR among different grades of bowel fibrosis were analyzed by one way ANOVA. The efficacy of MTR for predicting bowel fibrosis was evaluated by receiver operating characteristic curves analysis. The difference in MTRs between purely inflammatory bowel walls and mixed fibrotic and inflammatory bowel walls was analyzed by Student s t test. Results Sixty two resected bowel specimens from 31 patients including 9 purely inflammatory bowel walls and 53 mixed fibrotic and inflammatory bowel walls were obtained in this study. There were significant differences in MTR among non fibrotic [(21.45 ± 2.65)%], mildly [(30.88 ± 6.14)%], moderately [(35.14 ± 4.31)%] and severely [(35.14 ± 4.31)%] fibrotic walls (F=38.397,P<0.01). MTRs strongly correlated with fibrosis scores (r=0.681, P<0.01). High accuracy of MTRs was shown (curve under area=0.905, P<0.01) for differentiating moderately severely fibrotic from non fibrotic and mildly fibrotic bowel walls. Using MTR of 31.50% as a cutoff value, the sensitivity and specificity were 93.6% and 80.0%, respectively. The MTRs of purely inflammatory bowel walls [(21.45 ± 2.65)%] were significantly higher than that of mixed fibrotic and inflammatory [(36.28±5.21)%] bowel walls (t=-13.052,P<0.01). MTRs correlated with the scores of type Ⅰ collagen (r=0.325, P=0.044) but did not correlate with inflammation scores (r=-0.024, P=0.857). Conclusions MTI enables quantitative evaluation of bowel fibrosis in patients with CD and can be used to differentiate purely inflammatory CD from mixed fibrotic and inflammatory CD.

Objective To analyze the expression change of PTGFR gene in hip joint tissues of development dysplasia of the hip (DDH) and its correlation with DDH pathogenesis .Methods Eight age-and gender-matched children with DDH (DDH group) and control children (control group) were enrolled for conducting the compaison .The real-time quantitative PCR method and West-ern-blot method were adopted to detect the PTGFR mRNA and protein expression levels .Results PTGFR mRNA expression level in the hip articular capsule and ligamentum teres of the DDH group were significantly decreased compared with those of the control group (t=3 .472 ,2 .887 ,P<0 .05 ,) .The PTGFR protein expression level in the hip articular capsule and ligamentum teres of the DDH group were significantly decreased compared with those of the control group (t=5 .488 ,3 .942 ,P<0 .05) .Conclusion PTG-FR could play an important role in DDH pathogenesis and may be one of DDH pathogenic genes .