Radiation-induced cancer after treatment for nasopharyngeal carcinoma: a study from a high prevalence area.

BACKGROUND: Radiation-induced cancer (RIC) is a late complication in patients who have been treated for nasopharyngeal carcinoma (NPC). The comparison of index anatomic location, index histological type, and survival of RIC in patients with NPC after different radiotherapy modalities (intensity-modulated radiotherapy [IMRT], 3-dimensional conformal radiotherapy [3D-CRT], and conventional 2D radiotherapy) is currently unavailable. METHODOLOGY: A total of 38,565 patients with NPC who received curative-intent radiotherapy at Sun Yat-sen University Cancer Center between January 1986 and December 2017 were reviewed. A total of 141 patients who developed RIC and fulfilled the study criteria were included. Categorical variables were compared by the chi-square test or Fisher's exact test. Kaplan-Meier curves were used to evaluate overall survival. Cox proportional hazards models were used to examine the independent significance of RIC treatment. RESULTS: Among IMRT, 3D-CRT, and conventional 2D radiotherapy, the incidence of mandible RIC was higher in patients who received 3D-CRT (0.07%) than in those who received IMRT (0%). The proportion of mandible RICs was higher in patients who received 3D-CRT (16.667%) than in those who received IMRT (0%) and conventional 2D radiotherapy (3.529%). Regarding the histological type, the incidence of squamous cell carcinoma (SCC) was higher in patients who received conventional 2D radiotherapy (0.266%) than in those who received 3D-CRT (0.175%); patients who received IMRT had a higher proportion of SCC than those who received 3D-CRT/conventional 2D radiotherapy (86.4% vs. 41.7% vs. 74.2%); the incidence of sarcoma was higher in patients who received 3D-CRT (0.175%) than in those who received IMRT (0.025%); and the proportion of sarcoma was higher in patients who received 3D-CRT (41.667%) than in those who received IMRT (6.818%) and conventional 2D radiotherapy (17.647%). Patients who received surgery for RICs had better survival than those who received no surgery (64.49 vs. 12.42 months). In the univariate and multivariate analyses, surgery was an independent prognostic factor for overall survival. CONCLUSIONS: Our results have implications for long-term follow-up of RIC, multidisciplinary management, and patient counseling of RIC after nasopharyngeal carcinoma treatment by treating clinicians.

[Profiles and differences of submucosal microbial in peri-implantitis and health implants: A cross-sectional study].

OBJECTIVE: To describe the submucosal microbial profiles of peri-implantitis and healthy implants, and to explore bacteria that might be correlated with clinical parameters. METHODS: In the present cross-sectional study, 49 patients were recruited. Each patient contributed with one implant, submucosal biofilms were collected from 20 healthy implants and 29 implants with peri-implantitis. DNA was extracted and bacterial 16S ribosomal RNA (16S rRNA) genes were amplified. Submucosal biofilms were analyzed using 16S rRNA sequencing at Illumina MiSeq platform. Differences between the groups were determined by analyzing α diversity, microbial component and microbial structure. The potential correlation between the bacteria with pocket probing depth (PPD) of peri-implant calculated by Spearman correlation analysis. RESULTS: The α diversity of submucosal microbial of health group was significantly lower than that in peri-implantitis group (Chao1 index: 236.85±66.13 vs. 150.54±57.43, P < 0.001; Shannon index: 3.42±0.48 vs. 3.02±0.65, P=0.032). Principal coordinated analysis showed that the submucosal microbial structure had significant difference between healthy and peri-implantitis groups [R2=0.243, P=0.001, analysis of similarities (ANOSIM)]. Compared with healthy implants, relative abundance of periodontal pathogens were higher in peri-implantitis, including members of the red complex (Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola) and some members of orange complex (Precotella intermedia, Eubacterium nodatum, Parvimonas micra), as well as some new periodontal pathogens, such as Fillifactor alocis, Fretibacterium fastidiosum, Desulfobulbus sp._HMT_041, and Porphyromonas endodontalis. Spearman correlation analysis revealed that the relative abundance of Treponema denticola (r=0.686, P < 0.001), Tannerella forsythia (r=0.675, P < 0.001), Fretibacterium sp. (r=0.671, P < 0.001), Desulfobulbus sp._HMT_041 (r=0.664, P < 0.001), Filifactor alocis (r=0.642, P < 0.001), Fretibacterium fastidiosum (r=0.604, P < 0.001), Porphyromonas gingivalis (r=0.597, P < 0.001), Porphyromonas endodontalis (r=0.573, P < 0.001) were positive correlated with PPD. While the relative abundance of Rothia aeria (r=-0.615, P < 0.001) showed negatively correlation with PPD. CONCLUSION: Marked differences were observed in the microbial profiles of healthy implants and peri-implantitis. The members of red and orange complex as well as some new periodontal pathogens seem to play an important role in peri-implant disease. Compared with healthy implants, the submucosal microbial of peri-implantitis were characterized by high species richness and diversity.

[A study of the clinical curative effect of nucleos(t)ide analogues treated to pegylated interferon-α add-on therapy in patients with chronic hepatitis B].

Objective: To investigate the hepatitis B surface antigen (HBsAg) clearance condition and its predictive factors after treatment with nucleos(t)ide analogues to pegylated interferon-α add-on therapy in patients with chronic hepatitis B. Methods: Patients with chronic hepatitis B who visited the First Affiliated Hospital of Zhengzhou University from 2018~2019 were prospectively enrolled. HBsAg≤ 1500 IU/mL, hepatitis B e antigen-negative, HBV DNA undetectable, received antiviral treatment with nucleos(t)ide analogues for at least one year, and pegylated interferon-α add-on therapy for 48 weeks were included. The primary endpoint of study was to determine the proportion of HBsAg clearance at 72 weeks. Concurrently, the predictive factors for HBsAg clearance were analyzed. Quantitative and qualitative data were analyzed using a t-test or non-parametric test and a Fisher's exact test. Results: A total of 38 cases were included in this study, of which 13 cases obtained HBsAg clearance at 48 weeks of therapy and another six cases obtained HBsAg clearance throughout the extended treatment period of 72 weeks, accounting for 50.00% of all enrolled patients. There was a significant difference in HBsAg dynamics between the HBsAg clearance group and the non-clearance group (P < 0.05). Univariate logistic regression analysis showed that patients' age, baseline, 12-and 24-week HBsAg levels, and early HBsAg reduction were predictive factors for HBsAg clearance at 72 weeks of treatment. Multivariate logistic regression analysis showed that age (OR = 1.311; P = 0.016; 95% confidence interval: 1.051~1.635) and HBsAg levels at 24 weeks of treatment (OR = 4.481; P = 0.004; 95% confidence interval: 1.634~12.290) were independent predictors for HBsAg clearance. Conclusion: Hepatitis B e antigen-negative, nucleos(t)ide analogue treated, HBsAg ≤ 1500 IU/mL, and HBV DNA undetectable, peg-IFNα add-on treatment for 48 weeks could promote HBsAg clearance in patients with chronic hepatitis B. Six of the sixteen cases (37.50%) who did not obtain HBsAg clearance at week 48 did so with the course of therapy extended to week 72. Hence, the optimal individualized treatment strategy should be customized according to the predictors rather than the fixed 48-week course. Age (≤ 38), baseline HBsAg level (≤2.86 log(10)IU/ml), HBsAg level at 24 weeks (≤ 0.92 log(10)IU/ml), and 12-week HBsAg decrease from baseline (≥ 0.67 log(10)IU/ml) indicate that patients are highly likely to obtain HBsAg clearance at the 72 weeks of combination therapy, in which the combined indicator based on HBsAg level ≤0.92 log(10)IU/ml at 24 weeks will identify 85.0% to 100.0% of patients with HBsAg clearance.

[Efficacy of combined application of glycine powder air-polishing in non-surgical treatment of peri-implant diseases].

OBJECTIVE: To compare the clinical efficacy of combined application of glycine powder air-polishing and mechanical submucosal debridement in non-surgical treatment of peri-implant diseases. METHODS: A randomized controlled clinical study was carried out on patients diagnosed with peri-implant diseases in the Department of Periodontology, Peking University School and Hospital of Stomatology, between May of 2020 and June of 2021.Twenty-eight patients with totally sixty-two implants were enrolled.The patients were randomly divided into the test group and control group. The patients in the test group (13 subjects/32 implants) received mechanical submucosal debridement using titanium curettes combined with application of glycine powder air-polishing, while the control group (15 subjects/30 implants) received mechanical submucosal debridement using titanium only. Clinical parameters, such as plaque index (PLI), pocket probing depth (PPD), bleeding index (BI) and the percentage of suppuration on probing on implants' level (SoP%) were measured at baseline and 8 weeks after non-surgical intervention. Changes and group differences of clinical parameters of the implants before and 8 weeks after non-surgical intervention were compared. RESULTS: Mean PLI, PPD, BI of both the test group and control group significantly reduced 8 weeks after non-surgical intervention (P < 0.05). Compared with the control group, the test group achieved lower BI (2.7±0.8 vs. 2.2±0.7, P < 0.05), more reduction of BI (0.6±0.7 vs. 1.1±0.6, P < 0.01) and more reduction of SoP% (21.9% vs. 10%, P < 0.05) after non-surgical intervention. Both the control and test groups exhibited comparable PLI and PPD reductions (P>0.05). For the implants diagnosed with peri-implant mucositis, the test group revealed more signi-ficant reduction in BI and SoP% than the control group (1.0±0.7 vs. 0.4±0.7, P=0.02; 6.3% vs. 0, P=0.012). There was no significant difference existing in PLI and PD improvement between the control group and test group (P>0.05). For the implants diagnosed with peri-implantitis, there was no significant difference existing in PLI, PPD, BI and SoP% improvement values between the test and control groups (P>0.05). No complications or discomforts were reported during the study. CONCLUSION: Both treatment procedures could relieve the inflammation of peri-implant soft tissue. Non-surgical mechanical submucosal debridement combined application of glycine powder air-polishing is associated with significant reduction of soft tissue bleeding and suppuration on probing especially in the implants diagnosed with peri-implant mucositis.

Implementation of a youth and young adult e-cigarette cessation program within a dental clinic setting : A SToHN feasibility study.

Introduction: While significant progress has been made to decrease tobacco smoking among youth and young adults, e-cigarettes threaten to reverse the progress. The purpose of this study was to test the feasibility of the ReACH Assessment of Knowledge for E-Cigarettes (RAKE) e-cigarette cessation program targeting youth and young adults in Texas. Methods: Seven dental practitioners and 12 patients participated in this pilot study. Patients aged 15 to 29 who reported current e-cigarette use were recruited by their dental practitioner. All participants completed pre-and post-assessments-practitioners receiving the RAKE training and patients the RAKE cessation intervention. Descriptive statistics were calculated. Results: After RAKE training, all practitioners reported the RAKE cessation program as useful and an important part of patient care. In addition, after completing the program (5A's), 67% (n=9) patients reported that the program was helpful, and 100% (n=12) would recommend the program to other ENDS users. Conclusions: Practitioners and patients enhanced their knowledge of e-cigarettes and their harm to health. In addition, practitioners demonstrated their ability to implement the RAKE cessation program within the practice, and patients approved of the use of the program. This study illustrated the feasibility and acceptability of conducting an e-cigarette cessation study in dental practices and a critical need to develop and disseminate the program to young patients.

NLRP6-caspase 4 inflammasome activation in response to cariogenic bacterial lipoteichoic acid in human dental pulp inflammation.

AIM: To explore the presence and function of NLRP6-caspase 4 inflammasome in human pulp tissue and human dental pulp cells (HDPCs). METHODOLOGY: Pulp tissue was collected from freshly extracted human caries-free third molars and third molars with irreversible pulpitis. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were performed to assess the expression of NLRP6-caspase 4 inflammasome. HDPCs were prepared from normal human pulp tissues and challenged with Porphyromonas gingivalis LPS. Enzyme-linked immunosorbent assay (ELISA) and qRT-PCR were performed to assess if LPS can upregulate NLRP6 and caspase-4. HDPCs were further challenged with LPS followed with cytosolic Streptococcus mutans lipoteichoic acid (LTA). SiRNA targeting NLRP6 and Casp4 and pharmacology inhibitor Ac-FLTD-CMK and MCC950 were used to assess if Streptococcus mutans LTA can activate the NLRP6 but not the NLRP3 inflammasome. Western blot and ELISA were performed to evaluate inflammasome activation. The Student's t-test and one-way anova were used for statistical analysis. RESULTS: NLRP6-caspase 4 inflammasome was upregulated and activated in inflamed human dental pulp tissue. In HDPCs, Porphyromonas gingivalis LPS upregulated the expression of NLRP6, CASP1 and CASP4 in a type I interferon dependent manner. After LPS priming, cytosolic Streptococcus mutans LTA triggered NLRP6-caspase 4 inflammasome activation. Knockdown of NLRP6 or CASP4 using siRNA or using pharmacology inhibitor Ac-FLTD-CMK but not MCC950 efficiently suppressed inflammasome activation by cytosolic LTA. CONCLUSIONS: NLRP6-caspase 4 inflammasome may play an important role in pulp inflammation and immune defence. Inflammatory caspases represent a pharmacological target to restrain pulpal inflammation.

[Clinical characteristics and prognosis of MLL-AF6 positive patients with acute myeloid leukemia].

OBJECTIVE: To investigate the clinical features and prognosis of acute myeloid leukemia (AML) patients with the mixed lineage leukemia (MLL) gene rearrangements AF6 (MLL-AF6) positive. METHODS: In the study, 11 patients who were newly diagnosed with MLL-AF6 positive AML were analyzed retrospectively, related literature was reviewed to clarify the clinical features and prognosis of MLL-AF6 positive patients. RESULTS: Among the 11 patients, there were 6 males and 5 females, with a median age of 36 years. Six patients were diagnosed with AML M5 and five with M4 according to FAB classification (French-American-British classification systems). Gingival swelling and pain occurred in 6 cases and fever occurred in 5 cases. At first diagnosis, the median white blood cells were 55.5×109/L. Immunotype showed the expression of myeloid/monocyte and early stem cell series antigens. The expression level of MLL-AF6 fusion gene (real-time quantitative PCR) was 14.2%-214.5%, and 6/11 cases (54.5%) were associated with high EVI1 gene expression. Mutations of KRAS, TET2, ASXL1, TP53, DNMT3A, and FLT3-ITD were detected by next generation sequencing (NGS) in 4 patients. Chromosome G banding examination showed that 2 cases were t(6;11)(q27, q23) with complex karyotype abnormality, 4 cases with +8 abnormality and 2 cases with normal karyotype. Hematological complete remission (CR) was achieved in 8/11 patients (72.7%) after conventional induction chemotherapy, and primary drug resistance was observed in 3 patients. Two of the eight patients with CR were negative for minimal residual disease (MRD), with a median CR duration of 4.5 months. Two patients with positive MRD and three patients with refractory recurrence underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), but all died due to leukemia progression. At the end of follow-up on December 1, 2019, 2 patients were alive and 9 died, with median survival time of 9 months. CONCLUSION: The AML patients with MLL-AF6 positive were mostly young, the majority of FAB types were M4 and M5, and most of the patients often had fever as the first symptom, with increased white blood cells, accompanied by organ infiltration, and high EVI1 gene expression. The hematological remission rate of routine chemotherapy is not low, but it is difficult to achieve molecular remission, most of which have early recurrence. Early allo-HSCT in a molecular negative state may prolong the CR duration.

[Effect of band ligation or combined with tissue adhesive in the treatment of gastroesophageal varices and portal vein blood flow situational changes].

42 cases with gastroesophageal varices were prospectively included. The groups were treated with endoscopic band ligation or combined with tissue adhesive. The results showed that the left gastric vein internal diameter, average blood flow velocity and blood flow volume after the treatment of band ligation combined with tissue adhesive were significantly lower than that of the treatment of band ligation alone, and the differences were statistically significant (P < 0.05). Spleen and portal vein internal diameter, blood flow and average velocity, the liver and spleen size, shear wave velocity and liver function grade of the two groups after treatment did not change significantly (P > 0.05). The effective rate of band ligation combined with tissue adhesive in the treatment of esophageal and gastric varices (66.67%, 52.38%) were higher than that of band ligation alone (42.85%, 23.81%) (P > 0.05), and the re-bleeding rate of the latter was higher (9.52% and 19.05%, P > 0.05). Hence, it is suggested that the combined therapy is safe and more effective, and has no apparent effect on liver function and portal hypertension.

Accuracy of Nolla Method for Age Estimation of Northern Chinese Han Children.

ABSTRACT: Objective To study the accuracy of Nolla method for age estimation of Northern Chinese Han children aged between 5.00 and 14.99 years based on original transformation tables and multiple regression model. Methods A total of 2 000 orthopantomographs （OPGs） were collected from the Hospital of Stomatology, Xi'an Jiaotong University, including 1 000 males and 1 000 females. Development stage of 7 left mandibular permanent teeth （except third molars） was assessed based on Nolla method, then age estimation was conducted through transformation tables and multiple regression model, respectively. Firstly, the development stage results of 7 permanent teeth were added up and the estimated age was obtained through the original transformation tables. Secondly, 80% of the samples （80 males and 80 females in each age group） were randomly selected from 2 000 OPGs as the train set. The chronological age of the selected patients was taken as the dependent variable, while gender and the development stage results of 7 permanent teeth were taken as the independent variable to establish multiple regression model. The remaining 20% of the samples were substituted into the model as the test set, to verify the accuracy of age estimation by multiple regression model. Results Mean chronological ages of males and females were 10.03±0.09 years and 10.01±0.09 years, respectively. The age estimated by original transformation tables showed an overestimation for males （0.18 years on average） and an underestimation for females （0.02 years on average）, with mean absolute error （MAE） of 0.94 years and 0.97 years, respectively. While the results by multiple regression model showed that males were overestimated by 0.06 years on average and females were underestimated by 0.02 years on average. The MAE was 0.66 years and 0.77 years, respectively. Conclusion The Nolla method is suitable for age estimation of Northern Chinese Han children. Compared with the original transformation tables method, the multiple regression model is more accurate for age estimation.

[Two procedures for ridge preservation of molar extraction sites affected by severe bone defect due to advanced periodontitis].

OBJECTIVE: To evaluate and to compare dimensional alterations of hard and soft tissues in molar extraction sites with irregular deficiency of bone plates due to advanced periodontitis receiving two different procedures, namely the flapped and flapless techniques with Bio-Gide membrane covering the Bio-Oss material for ridge preservation. METHODS: Twenty-three patients with 24 infected-molar extraction sites received ridge preservation procedure, the first consecutive 12 sites belonged to the flap group (a full thickness mucoperiosteal flap and primary soft tissue closure) and the following 12 sites belonged to the flapless group (minimal flap with a collagen sponge and a secondary soft tissue closure). Width of keratinized tissue was evaluated before tooth extraction and after 6-month healing. Parallel periapical radiographs were taken immediately and 6 months after extraction to evaluate vertical bone changes. The width of the ridge was measured in the center of the ridge at the time of tooth extraction and after 6 months at implant placement. RESULTS: After 6 months, width of keratinized tissue decreased (1.6±1.5) mm in the flap group (P=0.004) when compared with (0.3±1.6) mm in the flapless group (P>0.05). Both groups showed increases in ridge height from the central aspect, (5.53±4.20) mm for flap group and (7.70±4.35) mm for flapless group. These differences between the groups were not statistically significant (P=0.226). The ridge widths were (9.5±2.2) mm for flap group and (9.3±1.0) mm for flapless group at the time of implant insertion, and no statistical significance was observed between the flap and flapless groups. CONCLUSION: The study points out that both ridge preservation techniques were effective in increasing ridge height and minimizing ridge resorption after tooth extraction, and the ridge width allowed the placement of implants 6 months after ridge preservation. The flapless technique gave positive outcome in terms of the keratinized gingival width than that of the flap technique.

Predictors of difficulty in intubation in patients with obstructive sleep apnoea.

OBJECTIVE: To evaluate predictors of difficult intubation in patients with obstructive sleep apnoea (OSA). METHODOLOGY: Prospective series of 405 OSA patients (350 males/55 females) who had upper airway surgery. Procedures included functional endoscopic sinus surgery, septoplasty, turbinate reduction, palate/tonsil surgery, and/or tongue base surgery. Intubation difficulty (ID) was assessed using Mallampati grade, Laryngoscopic grade (Cormack and Lehane), and clinical parameters including BMI, neck circumference, thyromental distance, jaw adequacy, neck movements and glidescope grading. RESULTS: Mean age was 41.6 years old; mean BMI 26.6; mean neck circumference 44.5cm; mean Apnea Hypopnea Index (AHI) was 25.0; and mean LSAT 82%. The various laryngeal grades (based on Cormack and Lehane), grade 1 - 53 patients (12.9%), grade 2A - 127 patients (31.0%), grade 2B - 125 patients (30.5%), grade 3 - 93 patients (22.7%) and grade 4 - seven patients (1.7%); hence, 24.4% had difficulties in intubation. Parameters that adversely affected intubation were, age of the patient, opening of mouth, retrognathia, overbite, overjet, limited neck extension, thyromental distance, Mallampati grade, and macroglossia (p<0.001). Body mass index (BMI) (p=0.087), neck circumference (p=0.645), neck aches (p=0.728), jaw aches (p=0.417), tonsil size (p=0.048), and AHI (p=0.047) had poor correlation with intubation. BMI-adjusted for Asians and Caucasians, showed that Asians were more likely to have difficulties in intubation (adjusted OR = 4.6 (95%Confidence Interval: 1.05 to 20.06) (p=0.043), compared to the Caucasian group. CONCLUSION: This study illustrates that difficult intubation can be predicted pre-surgery in order to avert any anaesthetic morbidity.

[Determination of Cortisol in Saliva by Liquid Chromatography Tandem Mass Spectrometry].

Objective: To establish a liquid chromatography tandem mass spectrometry method to determine the cortisol in saliva. Methods: Take 0.5 ml saliva sample into a 2 ml centrifuge tube, add excess sodium chloride and 1ml acetonitrile to it, then vortex for 3 min, centrifuge for 10 min at 15 000 r/min, and take 800 µl of the upper layer to another centrifuge tube. Finally, the sample was concentrated by a vacuum concentrator and brought to 200 µl with the initial mobile phase. Then, the sample was analyzed by liquid chromatography tandem mass spectrometry. The target compound was quantified by external standard curve method. Results: The linear range of the method was 0.02-5.00 ng/ml, r=0.999 9, the method limit of the detection was 0.002 ng/ml, the method limit of quantitative was 0.02 ng/ml, and the spiked recoveries were 89.60%-98.60%. The intra-assay precision was 1.90%-3.30%, and the inter-assay precision was 4.20%-9.00%; samples could be stored at -20 °C for at least 14 days. The determination of cortisol could not be interfered by other endogenous substances in the sample. Conclusion: The method is simple in pretreatment, high sensitivity, good reproducibility and good recovery, and it is suitable for the quantitative analysis of cortisol in saliva for normal and occupationally stressed populations.

Modulation of periodontitis progression using pH-responsive nanosphere encapsulating metronidazole or N-phenacylthialzolium bromide.

BACKGROUND AND OBJECTIVE: This study aimed to develop pH-responsive polylactide-glycolic acid co-polymer and chitosan (PLGA/chitosan) nanosphere as an inflammation-responsive vehicle and evaluate the potential of the nanosphere encapsulating metronidazole, an antibiotic, and N-phenacylthiazolium bromide (PTB), a host modulator, for treating periodontitis. MATERIAL AND METHODS: PLGA/chitosan nanospheres were fabricated using oil-in-water emulsion method. Experimental periodontitis was induced on the rat maxillae, and the sites were randomly allocated to four treatment categories, including periodontitis alone (PR), periodontitis with nanospheres alone, nanospheres encapsulating metronidazole (MT) and nanospheres encapsulating PTB (PB). The ligature was retained until the animals were killed, and the treatment outcome was evaluated by the progression of periodontal bone loss (PPBL), inflammatory cell infiltration and collagen deposition. RESULTS: The encapsulated drug was released rapidly from the nanospheres without significant initial burst release at pH 5.5. Compared with group PR, PPBL was significantly reduced in groups MT and PB on day 4 (P<.05). On day 21, PPBL was significantly lower in group PB (P<.05). In groups MT and PB, inflammation was significantly reduced in groups MT and PB relative to groups PR and periodontitis with nanospheres alone (P<.05), and collagen deposition was significantly greater relative to group PR (P<.05). CONCLUSION: PLGA/chitosan nanospheres encapsulating metronidazole or PTB showed potential for modulating periodontitis progression.

Layering Poly (lactic-co-glycolic acid)-based electrospun membranes and co-culture cell sheets for engineering temporomandibular joint disc.

The temporomandibular joint disk (TMJD) lacks blood vessels and is characterized by slow self-repair. Qualitative lesions in TMJD are difficult to repair. In this study, electrospun poly (lactic-co-glycolic acid) (PLGA) scaffolds were used to reconstruct temporomandibular joint discs by tissue engineering. Rabbit temporomandibular joint disc cells (TMJDCs) and rabbit synovium-derived mesenchymal stem cells (SMSCs) were co-cultured in 1:1 ratios. Cell sheets were induced by ascorbic acid incubated with electrospun PLGA scaffolds for 14 days in the presence (10 ng/ml in culture medium) or absence of TGF-ß3. Dimethylmethylene Blue Assay (DMMB) was used to determine the content of glycosaminoglycans in the extracellular matrix. The expression of Col1a1, Col2a1, Sox-9 and Runx-2 was quantified by RT-PCR, and the expression of type II collagen was observed by immunofluorescent staining. After 14 days of cultivation, the electrospun PLGA scaffold-loaded cell sheets could form an articular disc tissue with certain morphological characteristics. The expression of chondrogenic-related genes (Col2a1, Sox-9) and the secretion of extracellular matrix (GAG, type II collagen) in the co-culture group were close to those in the TMJDC group alone. The results suggest that PLGA electrospun scaffold-loaded co-cultured cell membrane could be used in the tissue engineering reconstruction of the temporomandibular joint disc.

Prokaryotic expression and identification of scavenger receptor B2.

There is still no effective clinical antiviral drug against human enterovirus 71 (EV71) infection, which causes hand, foot and mouth disease (HFMD) in children. Scavenger receptor class B member 2 (SCARB2) is an important receptor of EV71 as it plays a vital role in the early steps of viral infection. In this study, recombinant SCARB2 protein was expressed and purified in a prokaryotic expression system, and was identified by western blot with a monoclonal antibody and mass spectrometry analysis. Detection of the sera from mice immunized with the recombinant SCARB2 protein using ELISA and western blot showed good immunogenicity of the recombinant protein. Furthermore, in the neutralization test cytopathic effect was significantly decreased when EV71 was incubated with the immune sera before infection. In summary, the SCARB2 protein was expressed successfully, and the immune sera showed obvious antiviral effect against EV71. This study provides useful information about the interaction mechanism between SCARB2 and EV71, and is also helpful for further clinical treatment research of HFMD.

Evaluating the effectiveness of a preclinical practice of tooth preparation using digital training system: A randomised controlled trial.

PURPOSE: This study aimed to evaluate the effectiveness of preclinical training on ceramic crown preparation using digital training system compared with traditional training method. MATERIALS AND METHODS: A sample of 66 participating fourth-year undergraduate dental students were randomly assigned to one of two groups for ceramic crown preparation: experimental group as trained using digital method with Online Peer-Review System (OPRS) and Real-time Dental Training and Evaluation System (RDTES); control group as trained using traditional method with instructor demonstration and evaluation. At the completion of training periods, both groups performed the preparation of ceramic crown of upper left central incisor, which were blindly scored by the experienced instructors under the pre-defined assessment criteria. The results of both were compared using Student's t-test or Wilcoxon signed rank test. The level of significance was P < .05. The questionnaires regarding the benefits or drawbacks of digital training system were answered by the students of experimental group. RESULTS: Five of 15 items in the assessment outcome of the digital group were significantly better than the traditional group. The questionnaire results from the students of the experimental group indicated 96.97% of the students agreed or strongly agreed that using digital training system could better improve the practical ability than traditional method. The total scores of practical results were significantly positively correlated with the points of the questionnaires. CONCLUSION: The digital training system with OPRS and RDTES might be a good alternative to the traditional training method in the preclinical course of dental practice.

Novel mutations in the SEC24D gene in Chinese families with autosomal recessive osteogenesis imperfecta.

We sought to characterize the phenotypes and identify the SEC24D gene mutations associated with Chinese families of osteogenesis imperfecta (OI). Using whole-exome sequencing, we discovered two novel compound SEC24D mutations of OI patients. Our study extended both the phenotypic and the genotype of the OI patients with SEC24D mutations. INTRODUCTION: To date, only three compound heterozygous mutations in the SEC24D gene have been found to cause recessively inherited forms of OI. We sought to characterize the phenotypes and to identify the SEC24D gene mutations associated with Chinese families with OI. METHODS: Using whole-exome sequencing in two probands, we identified two novel compound heterozygous mutations in SEC24D. In family 1, the proband was a 23-year-old male; he had recurrent fractures and dentinogenesis imperfecta. His anterior fontanel was not closed, and he showed facial dysmorphism. A computed tomography three-dimensional imaging of the cranium showed skull deformities associated with a broad ossification defect in the frontoapical area, a widened sagittal suture, and Wormian bones. In family 2, the proband was a 7-year-old boy, who also had recurrent fractures and dentinogenesis imperfecta. His anterior fontanel was not closed, and he did not have obvious facial dysmorphism. RESULTS: We identified one novel compound heterozygous missense substitution in the proband in family 1, including c.2723G>A (p. Cys908Tyr) and c.2842T>C (p. Ser948Pro). In the proband in family 2, we identified another novel compound heterozygous missense substitution, including c.938G>A (p. Arg313His) and c.875C>T (p. Pro292Leu). CONCLUSIONS: We discovered two novel compound SEC24D mutations of autosomal recessive OI patients. Our study extended both the phenotypic and the genotypic spectrum of the autosomal recessive OI patients with SEC24D mutations.

Involvement of CD147 in alveolar bone remodeling and soft tissue degradation in experimental periodontitis.

BACKGROUND AND OBJECTIVE: The objective of this study was to investigate the possible roles of clusters of differentiation 147 (CD147) in bone resorption and mineralization through the bone markers of bone sialoprotein, osteocalcin, osteopontin and alkaline phosphatase (ALP), trabecular structure of alveolar bone and number of osteoclasts. We also investigated the effects of CD147 on inflammation and collagen breakdown. MATERIAL AND METHODS: Twenty-eight male Wistar rats were randomly divided into four groups of seven animals each: healthy group, periodontitis group, periodontitis + saline group and periodontitis + anti-CD147 groups. Hematoxylin and eosin staining were used for histological assessment. Alveolar bone loss and trabecula microstructure were evaluated using micro-computed tomography. Collagen fiber breakdown was assessed via picrosirius red staining. Tartrate-resistant acid phosphatase staining was conducted for osteoclast analysis. The expressions of ALP, bone sialoprotein, osteocalcin and osteopontin were evaluated using immunohistochemistry. RESULTS: Anti-CD147 treatment significantly inhibited alveolar bone loss and osteoclastogenesis, and improved the bone volume/tissue volume, and the trabecular thickness of alveolar bone. Histological staining revealed that anti-CD147 significantly reduced the infiltration of inflammation and limited the fractions of degraded areas in collagen fibers. The expression of bone markers (ALP, bone sialoprotein, osteocalcin and osteopontin) was enhanced by anti-CD147 treatment. CONCLUSION: The results of the anti-CD147 treatment indicate that CD147 was involved in alveolar bone mineralization, osteoclastogenesis and trabecular microstructure. The inhibition of CD147 could increase the expression level of osteogenic markers, alveolar bone crest height and suppressed collagen fiber degradation.

Coagulation in hindbrain membrane meningioma patients treated with different injections using acute hypervolemic hemodilution.

The aim of this study was to analyze the changes in coagulation in meningioma patients treated with different injections using the method of acute hypervolemic hemodilution (AHH). One hundred fifty hindbrain membrane meningioma patients were randomly divided into 5 groups, 30 per group. The first group were injected 40ml/time with Danhong after anesthesia induction; the second group were injected with 40ml~60ml/time Kangai and combined with interventional chemotherapy and embolization procedure; the third group of AHH were injected with polygeline 15ml/kg; the fourth group were injected with hydroxyethyl starch (130/0.4) sodium chloride in doses of 15ml/kg; the control group underwent basic treatment for lowering blood pressure and lowering blood fat. The changes of coagulation index were recorded before and after surgery and before and after the injection of different medications. Compared to the control group, for the first group of AHH, after being treated for 10 days and 30 days, the concentrations of bone specific alkaline phosphatase (BALP), bone Gla protein (BGP) and pro-collagen carboxy-terminal propeptide (PICP) were higher than that of the control group, the levels of endotoxin (ET) and C-reactive protein (CRP) were decreased compared to the control group (p less than 0.05); for the second group of AHH, after being treated for 10 days, the index of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (Fg) were not significantly changed, but the related level of vascular endothelial growth factor (VEGF) significantly decreased (p less than 0.05). Comparing the coagulation function index after surgery in the third and fourth groups, there were no significant changes in mean arterial pressure (MAP) level, heart rate (HR) value presented a low decrease, central venous pressure (CVP) level increased and the level of interleukin IL-6 showed a steady state after increasing. Analyzing the levels of interleukin IL-8 and tumor necrosis factor-α (TNF-α) after surgery, it was seen that in the third group they increased and in the fourth group they decreased (p less than 0.05). Danhong injection improved the coagulation function and microcirculation of patients, Kangai injection and interventional chemotherapy and embolization restrained the appearance of tumor angiogenesis, AHH operation with polygeline injection and hydroxyethyl starch (130/0.4) sodium chloride kept blood flow in normal parameters.

Age-related changes of bone mineral density in mandible by quantitative computed tomography.

Quantitative Computed Tomography (QCT) was used to investigate age-related changes in trabecular bones of the mandible. The volumetric Bone Mineral Density (vBMD) of mandibles was found to be increasing with aging in the 20-29, 30-39, 40-49 age groups, while resulted decreasing in the 50~ years age group in a Chinese population. The aim of this study was to validate QCT as a reliable method to measure the vBMD of the mandible and to assess vBMD of the mandible in a Chinese population. A total of seven hundred and eighteen volunteers (299 males, 419 females), ranging from 20 to 63 years of age, previously enrolled in another study, were included for vBMD measurements by QCT. A total of 50 subjects were enrolled for the validation of QCT measurement. Basic information (age, height and weight), and vBMD of the mandible (middle, body and angle) were recorded. Comparisons among age and sex groups were analyzed using the Mann-Whitney test. Linear correlation analysis between vBMD and age was performed. The mandibular vBMD was twice measured with QCT by one operator and resulted highly repeatable (ICC 0. 97, P 0. 05). The vBMD in the middle of the mandible was the highest, followed by that in the body and at the angle of mandible. In each age group, the mean vBMD increased with aging except for the 50~ years age group (P less than 0.05) in which it decreased. The mean mandibular vBMD was higher in females than males in each age group (P less than 0.05). Correlation between vBMD and age was statistically significant (r=0.15, P less than 0.01). QCT shows high precision for the measurement of BMD in the mandible. The present study provides normative data of the mandible in an age- and sex-stratified manner, which can be helpful in clinical practice.