The Effect of Local Application of Tea Tree Oil Adjunctive to Daily Oral Maintenance and Nonsurgical Periodontal Treatment: A Systematic Review and Meta-Analysis of Randomised Controlled Studies.

PURPOSE: To evaluate the efficacy of the adjunctive use of tea tree oil (TTO) for dental plaque control and nonsurgical periodontal treatment (NSPT). MATERIALS AND METHODS: Three electronic databases were searched from 2003. The reference lists of the included articles and relevant reviews were also manually searched. Randomised controlled trials reporting the clinical outcomes of the topical use of TTO as an adjunct to daily oral hygiene or scaling and root planing (SRP) were included. Regarding the use of TTO as an adjunctive to daily oral hygiene, the primary outcome was plaque index (PI) reduction. Regarding the use of TTO as an adjunctive to SRP, probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain were the primary outcomes. The secondary outcomes were adverse events. RESULTS: Eleven studies were included for qualitative analysis, 9 studies were included for quantitative analysis, and 6 studies were included to examine the application of TTO mouthwash as an adjunctive to daily oral hygiene. In addition, three studies were included to analyse the subgingival use of TTO adjunctive to SRP at selected sites. The results indicated a nonsignificant improvement in PI reduction in the TTO mouthwash group compared with placebo. The incidence of adverse events was statistically significantly greater in the CHX group than in the TTO group. For subgingival use of TTO adjunctive to SRP, beneficial effects were observed in the TTO group compared with SRP alone in terms of PPD and CAL at both three and six months post-treatment. However, an unpleasant taste was reported in three out of four studies. CONCLUSION: There is a lack of strong evidence to support the beneficial effects of TTO. Studies with larger sample sizes and standardised evaluation criteria are needed to further demonstrate the clinical relevance of TTO.

Residues of chlorpyrifos in the environment induce resistance in Aedes albopictus by affecting its olfactory system and neurotoxicity.

Aedes albopictus, a virus-vector pest, is primarily controlled through the use of insecticides. In this study, we investigated the mechanisms of resistance in Ae. albopictus in terms of chlorpyrifos neurotoxicity to Ae. albopictus and its effects on the olfactory system. We assessed Ca2+-Mg2+-ATP levels, choline acetyltransferase (ChAT), Monoamine oxidase (MAO), odorant-binding proteins (OBPs), and olfactory receptor (OR7) gene expression in Ae. albopictus using various assays including Y-shaped tube experiments and DanioVision analysis to evaluate macromotor behavior. Our findings revealed that cumulative exposure to chlorpyrifos reduced the activity of neurotoxic Ca2+-Mg2+-ATPase and ChAT enzymes in Ae. albopictus to varying degrees, suppressed MAO-B enzyme expression, altered OBPs and OR7 expression patterns, as well as affected evasive response, physical mobility, and cumulative locomotor time under chlorpyrifos stress conditions for Ae. albopictus individuals. Consequently, these changes led to decreased feeding ability, reproductive capacity, and avoidance behavior towards natural enemies in Ae. albopictus populations exposed to chlorpyrifos stressors over time. To adapt to unfavorable living environments, Ae. albopictus may develop certain tolerance mechanisms against organophosphorus pesticides. This study provides valuable insights for guiding rational insecticide usage or dosage adjustments targeting the nervous system of Ae. albopictus.

Positive rate and quantification of amyloid pathology with [18F]florbetapir in the urban Chinese population.

OBJECTIVES: Amyloid deposition is considered the initial pathology in Alzheimer's disease (AD). Personalized management requires investigation of amyloid pathology and the risk factors for both amyloid pathology and cognitive decline in the Chinese population. We aimed to investigate amyloid positivity and deposition in AD patients, as well as factors related to amyloid pathology in Chinese cities. METHODS: This cross-sectional multicenter study was conducted in Shanghai and Zhengzhou, China. All participants were recruited from urban communities and memory clinics. Amyloid positivity and deposition were analyzed based on amyloid positron emission tomography (PET). We used partial least squares (PLS) models to investigate how related factors contributed to amyloid deposition and cognitive decline. RESULTS: In total, 1026 participants were included: 768 participants from the community-based cohort (COMC) and 258 participants from the clinic-based cohort (CLIC). The overall amyloid-positive rates in individuals with clinically diagnosed AD, mild cognitive impairment (MCI), and normal cognition (NC) were 85.8%, 44.5%, and 26.9%, respectively. The global amyloid deposition standardized uptake value ratios (SUVr) (reference: cerebellar crus) were 1.44 ± 0.24, 1.30 ± 0.22, and 1.24 ± 0.14, respectively. CLIC status, apolipoprotein E (ApoE) ε4, and older age were strongly associated with amyloid pathology by PLS modeling. CONCLUSION: The overall amyloid-positive rates accompanying AD, MCI, and NC in the Chinese population were similar to those in published cohorts of other populations. ApoE ε4 and CLIC status were risk factors for amyloid pathology across the AD continuum. Education was a risk factor for amyloid pathology in MCI. Female sex and age were risk factors for amyloid pathology in NC. CLINICAL RELEVANCE STATEMENT: This study provides new details about amyloid pathology in the Chinese population. Factors related to amyloid deposition and cognitive decline can help to assess patients' AD risk. KEY POINTS: • We studied amyloid pathology and related risk factors in the Chinese population. •·The overall amyloid-positive rates in individuals with clinically diagnosed AD, MCI, and NC were 85.8%, 44.5%, and 26.9%, respectively. • These overall amyloid-positive rates were in close agreement with the corresponding prevalence for other populations.

Chitosan Hydrogel-Delivered ABE8e Corrects PAX9 Mutant in Dental Pulp Stem Cells.

Hypodontia (dental agenesis) is a genetic disorder, and it has been identified that the mutation C175T in PAX9 could lead to hypodontia. Cas9 nickase (nCas9)-mediated homology-directed repair (HDR) and base editing were used for the correction of this mutated point. This study aimed to investigate the effect of HDR and the base editor ABE8e in editing PAX9 mutant. It was found that the chitosan hydrogel was efficient in delivering naked DNA into dental pulp stem cells (DPSCs). To explore the influence of the C175T mutation in PAX9 on the proliferation of DPSCs, hydrogel was employed to deliver PAX9 mutant vector into DPSCs, finding that the PAX9-containing C175T mutation failed to promote the proliferation of DPSCs. Firstly, DPSCs stably carrying PAX9 mutant were constructed. Either an HDR or ABE8e system was delivered into the above-mentioned stable DPSCs, and then the correction efficiency using Sanger sequencing and Western blotting was determined. Meanwhile, the ABE8e presented significantly higher efficiency in correcting C175T compared with HDR. Furthermore, the corrected PAX9 presented enhanced viability and differentiation capacity for osteogenic and neurogenic lineages; the corrected PAX9 even possessed extremely enhanced transcriptional activation ability. In summary, this study has powerful implications for studies into base editors, chitosan hydrogel, and DPSCs in treating hypodontia.

Brain Functional Alterations and Association with Cognition in People with Preclinical Subjective Cognitive Decline and Objective Subtle Cognitive Difficulties.

Subjective cognitive decline (SCD) and objective subtle cognitive difficulties (Obj-SCD) are considered the initial stages of aberrant cognition prior to mild cognitive impairment (MCI) due to Alzheimer's disease (AD). We aimed to determine the difference of brain function of SCD and Obj-SCD, furthermore, to figure out which one could be the marker of early AD. One hundred and eighty-five participants were enrolled in this study to determine the amyloid pathology and glucose metabolism changes in SCD and Obj-SCD. The association of amyloid deposition and glucose metabolism with cognitive domains were also investigated. Obj-SCD displayed significantly increased amyloid deposition in frontal and temporal lobes compared to SCD and normal cognitive control (NCC). No difference of amyloid deposition between SCD and NCC, and no difference of glucose metabolism among the three groups were observed. Amyloid deposition was associated with function of memory, language and executive domains, and glucose metabolism was only associated with executive function in Obj-SCD. Amyloid deposition was only associated with executive function in SCD. Obj-SCD could be the early stage of AD, which displayed significant increased amyloid deposition, and the increased amyloid deposition was associated with cognitive function in different domains.

Graph Analysis of Functional Brain Topology Using Minimum Spanning Tree in Subjective Cognitive Decline.

BACKGROUND: Subjects with subjective cognitive decline (SCD) are proposed as a potential population to screen for Alzheimer's disease (AD). OBJECTIVE: Investigating brain topologies would help to mine the neuromechanisms of SCD and provide new insights into the pathogenesis of AD. METHODS: Objectively cognitively unimpaired subjects from communities who underwent resting-state BOLD-fMRI and clinical assessments were included. The subjects were categorized into SCD and normal control (NC) groups according to whether they exhibited self-perceived cognitive decline and were worried about it. The minimum spanning tree (MST) of the functional brain network was calculated for each subject, based on which the efficiency and centrality of the brain network organization were explored. Hippocampal/parahippocampal volumes were also detected to reveal whether the early neurodegeneration of AD could be seen in SCD. RESULTS: A total of 49 subjects in NC and 95 subjects in SCD group were included in this study. We found the efficiency and centrality of brain network organization, as well as the hippocampal/parahippocampal volume were preserved in SCD. Besides, SCD exhibited normal cognitions, including memory, language, and execution, but increased depressive and anxious levels. Interestingly, language and execution, instead of memory, showed a significant positive correlation with the maximum betweenness centrality of the functional brain organization and hippocampal/parahippocampal volume. Neither depressive nor anxious scales exhibited correlations with the brain functional topologies or hippocampal/parahippocampal volume. CONCLUSION: SCD exhibited preserved efficiency and centrality of brain organization. In clinical practice, language and execution as well as depression and anxiety should be paid attention in SCD.

Challenges and Tissue Engineering Strategies of Periodontal-Guided Tissue Regeneration.

Periodontitis is a chronic infectious oral disease with a high prevalence rate in the world, and is a major cause of tooth loss. Nowadays, people have realized that the local microenvironment that includes proteins, cytokines, and extracellular matrix has a key influence on the functions of host immune cells and periodontal ligament (PDL) stem cells during a chronic infectious disease such as periodontitis. The above pathological process of periodontitis will lead to a defect of periodontal tissues. Through the application of biomaterials, biological agents, and stem cell therapy, guided tissue regeneration (GTR) makes it possible to reconstruct healthy PDL tissue after local inflammation control. To date, substantial advances have been made in periodontal GTR. However, the process of periodontal remodeling experiences complex microenvironment changes, and currently periodontium regeneration still remains to be a challenging feat. In this review, we summarized the main challenges in each stage of periodontal regeneration, and try to put forward appropriate biomaterial treatment mechanisms or potential tissue engineering strategies that provide a theoretical basis for periodontal tissue engineering regeneration research.

H2O2 activation over Co substitution in Fe1-xS for tetracycline degradation: Effect of Co substitution.

In this work, the effect of Co substitution in the Fe1-xS (CSP) on the activation of H2O2 to degrade tetracycline (TC) is investigated. A series of CSP samples with different Co content are synthesized via a high-temperature sulfidation method and characterized by XRD, XPS, SEM, and electrochemical analysis. The result showed that low Co content (≤1%) promotes the catalytic activity of Fe1-xS, while excessive Co (1%﹤x ≤ 3%) inhibits its catalytic activity. The investigation of Behnajady-Modirshahla-Ghanbery kinetic model (BMG) showed that the maximum initial degradation rate of TC over 1.0% CSP/H2O2 was 1.6 times than that of in CSP/H2O2 system. The Box-Behnken with Response Surface Methodology was employed to verify optimum condition for TC degradation. The quenching experiments and ESR determined that ·OH, ·O2- and 1O2 were involved in TC degradation with the treatment of 1.0% CSP/H2O2 system. Electrochemical analysis, ·OH quantification, and metal ion concentrations measure reveal that Co substitution accelerates electron transfer efficiency and Fe2+ regeneration. Furthermore, nine intermediates are identified and the possible degradation pathway of TC is proposed. The unique effect of Co provides novel insight and efficient strategies for improving the reactivity of iron sulfide.

Validation of Chinese Version of SKT (Syndrom Kurztest): A Short Cognitive Performance Test for the Assessment of Memory and Attention.

(1) Background: The SKT (Syndrom Kurztest) is a short cognitive performance test that consists of nine subtests and assesses deficits of memory and attention. This study was aimed at exploring the SKT target population in China and evaluating the reliability and validity of the Chinese version of the SKT; (2) Methods: A total of 1624 patients aged over 60 years old were recruited in the Sixth People's Hospital in Shanghai. The SKT raw scores were recorded. Cronbach's alpha coefficient was determined to assess the internal consistency reliability of the SKT. Principal factor analysis was performed to evaluate the factor structure of the SKT subtests. Correlation analyses were carried out to confirm the relationship between the modified SKT and standardized neuropsychological tests. The influence of age and educational years on SKT raw scores were detected using multiple regression analyses. Validations of the SKT subtests for detecting Mild Cognitive Impairment (MCI) from Negative Control(NC)(were determined by Receiver operating characteristic (ROC) curves; (3) Results: The internal consistency among the subtests' scores was high: Cronbach's α = 0.827. The SKT memory test provided a high predictive validity in detecting aMCI with a sensitivity of 90.1% and specificity of 79.3%. (4) Conclusions: Based on our experience with 1624 elderly patients in Shanghai, the Chinese version of SKT has good stability and may be a reliable and valid screening tool for detecting MCI.

The effect of drug dose and duration of adjuvant Amoxicillin-plus-Metronidazole to full-mouth scaling and root planing in periodontitis: a systematic review and meta-analysis.

OBJECTIVES: The aim is to explore the optimal drug dose and duration of adjunctive Amoxicillin-plus-Metronidazole (AMX/MET) to full-mouth scaling and planing (FMSRP) in periodontitis. METHODS: An electronic search in four databases and manual search in four journals were conducted for randomised clinical trials comparing AMX/MET adjunct to FMSRP with FMSRP alone for at least 3 months. RESULTS: Eleven studies were eligible and included. The primary outcome was clinical attachment level (CAL) gain, the secondary outcomes were periodontal pocket depth (PPD) reduction and adverse events. Our results showed a beneficial effect of adjunctive AMX/MET with higher drug dose to FMSRP for CAL gain and PPD reduction at 3 months, and the benefit remained stable at 6 months. However, minimal difference among three-seven-and ten-day drug duration was observed. In addition, the risk difference of adverse events was minimal between two groups. CONCLUSION: FMSRP adjunct to a high drug dose of 500/500 mg of AMX/MET showed a significant and stable improvement on 6-month follow-up period. No decision for drug duration could be made due to limited evidence. CLINICAL RELEVANCE: On 6-month follow-up, higher dose of AMX/MET adjunct to FMSRP could provide a stable clinical effect. No recommendation for drug duration could be made.

MicroRNA-155-5p Contributes to 5-Fluorouracil Resistance Through Down-Regulating TP53INP1 in Oral Squamous Cell Carcinoma.

The anticancer drug 5-fluorouracil (5-FU) resistance is a major obstacle to reducing the effectiveness of cancer treatment, and its detailed mechanism has not been fully elucidated. Here, in 5-FU-resistant human oral squamous cell carcinoma (OSCC) HSC3 cells (HSC3/5-FU), the levels of 21 miRNA candidates were detected using RT-PCR and miR-155-5p level increased strikingly in HSC3/5-FU cells compared to HSC3 cells. Compared with HSC3 cells, the CCK-8 assay showed that the HSC3/5-FU cells transfected with miR-155-5p inhibitors decreased 5-FU IC50. Ectopic expression of miR-155-5p in HSC3 and HSC4 cells increased 5-FU IC50 (CCK-8 assay), migration (wound-healing and transwell assays) and invasion (transwell assay) abilities. Seven miR-155-5p target candidates were discovered by miRNA prediction algorithms (miRDB, Targetscan, and miRWalk), and the RT-PCR results showed that in HSC3/5-FU cells TP53INP1 was of the lowest mRNA expression level compared with HSC3 cells. The RT-PCR and Western blotting assays showed that ectopic expression of miR-155-5p in HSC3 and HSC4 cells decreased TP53INP1 expression level. Furthermore, the luciferase reporter and RNA pull-down assays determined the interference effect of miR-155-5p on TP53INP1 expression. The enhancement of cell viability (CCK-8 assay), migration (wound-healing and transwell assays) and invasion (transwell assay) by miR-155-5p after 5-FU treatment was reversed by TP53INP1 overexpression. After treatment with 5-FU, HSC3-miR-155-5p tumor-bearing nude mice presented growing tumors, while HSC3-TP53INP1 group possessed shrinking tumors. In conclusion, these results lead to the proposal that miR-155-5p enhances 5-FU resistance by decreasing TP53INP1 expression in OSCC.

The effect of low-level laser therapy as an adjunct to periodontal surgery in the management of postoperative pain and wound healing: a systematic review and meta-analysis.

The meta-analysis and systematic review aimed to evaluate the effect of low-level laser therapy (LLLT) as an adjunct to periodontal surgery in the management of postoperative pain and wound healing. An electronic search in 4 databases (PubMed, Embase, Cochrane, and OpenGrey) was conducted for randomized clinical trials reporting the effectiveness of LLLT used as an adjunct to periodontal surgery to alleviate pain and accelerate wound healing compared with surgery alone. Finally, 13 studies were eligible and included. The results showed a significant difference of pain relief between groups at day 3 post-surgery, whereas no difference was found at day 7. Moreover, a significant reduction was observed in the mean analgesic intake during the first week in the LLLT group. On day 14, the adjunctive use of LLLT showed significantly faster re-epithelialization and better wound healing in palatal donor sites following free gingival graft procedures. Based on the results, LLLT used as an adjunct to periodontal surgery positively influenced postsurgical pain control. Low power (≤ 500 mW) combined with energy density ≥ 5 J/cm2 might be more appropriate for postoperative pain relief. Moreover, adjunctive LLLT to free gingival grafts could significantly accelerate wound healing of palate sites at early healing phase. Multicenter studies using different LLL parameters without postsurgical analgesics are needed to determine optimal laser settings.

Adjunctive subgingival application of Chlorhexidine gel in nonsurgical periodontal treatment for chronic periodontitis: a systematic review and meta-analysis.

BACKGROUND: Subgingival applications of chlorhexidine (CHX) gel are commonly used as an adjunct in nonsurgical periodontal treatment (NSPT) for chronic periodontitis (CP). However, there is lack of systematic review and meta-analysis justifying the effects of adjunctive CHX gel on clinical outcomes. The objective of this meta-analysis was to evaluate the efficacy of adjunctive subgingival administration of CHX gel in NSPT compared to NSPT alone for CP. METHODS: An electronic search of four databases and a manual search of four journals were conducted up to August 2019. Only randomized controlled trials reporting on the clinical outcomes of subgingival use of CHX gel adjunct to scaling and root planing (SRP), as compared to SRP alone or with placebo, for at least 3 months were included. Primary outcomes were probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain at 3 and 6 months, when data on at least three studies were obtained. RESULTS: Seventeen studies were included for qualitative analysis and seven studies for quantitative analysis (four studies for the application of CHX gel adjunct to SRP at selected sites with at least pocket depth ≥ 4 mm and three studies for comparison of full-mouth disinfection (FMD) with subgingival use of CHX gel and full-mouth scaling and root planing (FMSRP). For subgroups, the clinical outcomes between adjunctive use of Xanthan-based CHX gel (XAN-CHX gel) and CHX gel were analyzed. Results indicated a significant improvement of PPD reduction following local adjunctive administration of XAN-CHX gel for SRP at selected sites (MD: 0.15 mm). However, no difference was found in CAL gain. Moreover, no significant difference was observed in PPD and CAL at both 3 and 6 months post-treatment between FMD and FMSRP. CONCLUSION: Adjunctive subgingival administration of XAN-CHX gel at individual selected sites in NSPT appears to provide slight benefits in PPD reduction compared to NSPT alone for CP. Due to the lack of high-quality studies, further studies with larger sample sizes and strict standards are needed to confirm the conclusions.

Maintained Properties of Aged Dental Pulp Stem Cells for Superior Periodontal Tissue Regeneration.

Owing to excellent therapeutic potential, mesenchymal stem cells (MSCs) are gaining increasing popularity with researchers worldwide for applications in tissue engineering, and in treatment of inflammation-related and age-related disorders. However, the senescence of MSCs over passaging has limited their clinical application owing to adverse effect on physiological function maintenance of tissues as well as disease treatment. An inflammatory microenvironment is one of the key contributors to MSC senescence, resulting in low regeneration efficiency. Therefore, MSCs with high resistance to cellular senescence would be a benefit for tissue regeneration. Toward this end, we analyzed the senescence properties of different types of stem cells during culture and under inflammation, including dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), bone marrow mesenchymal stem cells (BMMSCs), and adipose-derived stem cells (ADSCs). Overall, the DPSCs had higher proliferation rates, lower cellular senescence, and enhanced osteogenesis maintenance compared to those of non-dental MSCs cultured from passage three to six. The expression profiles of genes related to apoptosis, cell cycle, and cellular protein metabolic process (contributing to the cell self-renewal ability and metabolic processes) significantly differed between DPSCs and BMMSCs at passage three. Moreover, DPSCs were superior to BMMSCs with regards to resistance to lipopolysaccharide-induced apoptosis and senescence, with enhanced osteogenesis in vitro, and showed improved periodontal regeneration after injection in a miniature pig periodontitis model in vivo. Overall, the present study indicates that DPSCs show superior resistance to subculture and inflammation-induced senescence and would be suitable stem cells for tissue engineering with inflammation.

Low serum paraoxonase1 activity levels predict coronary artery disease severity.

Paraoxonase1 (PON1) activity is closely related to coronary artery disease (CAD). However, whether PON1 activity can predict the degree of coronary stenosis remains unknown. In the present study, the serum PON1 activity and related factors that influence PON1 activity were analyzed in 186 patients with diagnostic coronary angiography. The serum PON1 activity was determined using a spectrophotometry-based assay in 186 patients with diagnostic coronary angiography, in which coronary stenosis severity was graded and clinically defined as single- or multi-vessel stenosis >50%. Target lesion stenosis was quantified via quantitative coronary angiography (QCA). The serum PON1 activity was significantly decreased in the CAD group, the multiple coronary stenosis subgroup, and the diabetes mellitus subgroup compared with each control group. The PON1 activity was positively correlated with the High density lipoprotein cholesterol (HDL-C) and Apolipoprotein A1 (ApoA1). Males, smoking, diabetes, and heart failure were identified as factors that influenced PON1 activity. Furthermore, a Receiver Operating Characteristic Curve (ROC) analysis indicated that a PON1 activity cut-off point of 330 U/L could predict CAD with a sensitivity of 52% and a specificity of 65%. In conclusion, low PON1 activity predicted the degree of coronary lesion, particularly in multiple vessel lesions, smokers, and diabetes, which may represent a biochemical marker for the severity of CAD.

Periodontal regeneration in swine after cell injection and cell sheet transplantation of human dental pulp stem cells following good manufacturing practice.

BACKGROUND: Periodontitis, one of the most prevalent infectious diseases in humans, results in the destruction of tooth-supporting tissues. The purpose of the present study is to evaluate the effect of cell injection and cell sheet transplantation on periodontal regeneration in a swine model. METHODS: In the present study, human dental pulp stem cells (hDPSCs) were transplanted into a swine model for periodontal regeneration. Twelve miniature pigs were used to generate periodontitis with bone defects of 5 mm in width, 7 mm in length, and 3 mm in depth. hDPSCs were obtained for bone regeneration using cell injection or cell sheet transplantation. After 12 weeks, clinical, radiological, and histological assessments of regenerated periodontal tissues were performed to compare periodontal regeneration treated with xenogeneic cell injection and cell sheet implantation. RESULTS: Our study showed that translating hDPSCs into this large animal model could significantly improve periodontal bone regeneration and soft tissue healing. After 12 weeks, both the hDPSC sheet treatment and hDPSC injection significantly improved periodontal tissue healing clinically in comparison with the control group. The volume of regenerative bone in the hDPSC sheet group (52.7 ± 4.1 mm(3)) was significantly larger than in the hDPSC injection group (32.4 ± 5.1 mm(3)) (P < 0.05). The percentage of bone in the periodontium in the hDPSC injection group was 12.8 ± 4.4 %, while it was 17.4 ± 5.3 % in the hDPSC sheet group (P < 0.05). CONCLUSION: Both hDPSC injection and cell sheet transplantation significantly regenerated periodontal bone in swine. The hDPSC sheet had more bone regeneration capacity compared with hDPSC injection.

Adenovirus-mediated transfer of hepatocyte growth factor gene to human dental pulp stem cells under good manufacturing practice improves their potential for periodontal regeneration in swine.

INTRODUCTION: Periodontitis is one of the most widespread infectious diseases in humans. We previously promoted significant periodontal tissue regeneration in swine models with the transplantation of autologous periodontal ligament stem cells (PDLSCs) and PDLSC sheet. We also promoted periodontal tissue regeneration in a rat model with a local injection of allogeneic bone marrow mesenchymal stem cells. The purpose of the present study is to investigate the roles of the hepatocyte growth factor (HGF) and human dental pulp stem cells (DPSCs) in periodontal tissue regeneration in swine. METHOD: In the present study, we transferred an adenovirus that carried HGF gene into human DPSCs (HGF-hDPSCs) under good manufacturing practice (GMP) conditions. These cells were then transplanted into a swine model for periodontal regeneration. Twenty miniature pigs were used to generate periodontitis with bone defect of 5 mm in width, 7 mm in length, and 3 mm in depth. After 12 weeks, clinical, radiological, quantitative and histological assessment of regenerated periodontal tissues was performed to compare periodontal regeneration in swine treated with cell implantation. RESULTS: Our study showed that injecting HGF-hDPSCs into this large animal model could significantly improve periodontal bone regeneration and soft tissue healing. A hDPSC or HGF-hDPSC sheet showed superior periodontal tissue regeneration compared to the injection of dissociated cells. However, the sheets required surgical placement; thus, they were suitable for surgically-managed periodontitis treatments. The adenovirus-mediated transfer of the HGF gene markedly decreased hDPSC apoptosis in a hypoxic environment or in serum-free medium, and it increased blood vessel regeneration. CONCLUSION: This study indicated that HGF-hDPSCs produced under GMP conditions significantly improved periodontal bone regeneration in swine; thus, this method represents a potential clinical application for periodontal regeneration.

Mesenchymal stem cell-mediated treatment of oral diseases.

In the oral maxillofacial region, there are significant demands for repairing severe tissue defects caused by congenital malformations, oncologic resection, post-traumatic loss, and pathologic degenerative destruction such as periodontitis. Mesenchymal stem cells (MSCs) are adult stem cells whose multipotency has been investigated for therapeutic applications. This review highlights the main MSCs involved in the tissue regeneration of oral maxillofacial region and recent advances in dental MSC-based tissue regeneration and treatments in this region. MSCs isolated from oral maxillofacial sources have higher proliferation rates and are more capable of forming bone and dental tissues. Large animal models of oral diseases or defects were established and treated with MSCs. Miniature pigs or dogs more closely mimic disease in humans and provide a useful means for translating research into clinical applications. MSCs exert other beneficial effects, including immunomodulation and paracrine processes. The immunoregulatory properties of MSCs facilitate their application to oral diseases and tissue regeneration. Besides autologous MSCs being an excellent cell source for tissue engineering and regenerative medicine, allogeneic MSC-based treatment also provides a safe and effective therapeutic modality, the use of allogeneic MSCs in highly standardized clinical trials could lead to a better understanding of their real-life applications, which sheds light on potential clinical applications for treating oral diseases.

Regional differences in job satisfaction for mainland Chinese nurses.

BACKGROUND: Although there is an abundance of research on nurses' job satisfaction, there is a paucity of publications on the regional differences that impact on nurses' job satisfaction. PURPOSE: To compare the differences between northern and southern hospitals in Mainland China with respect to nurses' job satisfaction. METHODS: A cross-sectional survey design was selected. Data were analyzed using descriptive statistics, independent t test, chi-square test, correlation, and linear regression. RESULTS: Nurses in northern hospitals were older, had higher educational levels yet received lower pay in comparison with their counterparts in the southern region. Despite these salary differences, those in the north consistently rated their job satisfaction greater in all areas except professional opportunities. CONCLUSION: Regional differences were related to nurses' job satisfaction. Potential contributing factors included philosophical, cultural, and economic differences between the 2 regions. The noteworthy regional differences that potentially related to nurse' job satisfaction should be investigated in future studies.

[Influence of cobalt chloride-induced hypoxia on the proliferation and apoptosis of periodontal ligament cells].

PURPOSE: To investigate the effect of hypoxia on proliferation and expression of HIF-1alpha and Caspase-3 in human periodontal ligament cells (PDLCs). METHODS: Human PDLCs were exposed to cobalt chloride in order to mimic hypoxia. Cell viability of PDLCs was determined by MTT methods. Expression of HIF-1alpha and Caspase-3 was measured by real time PCR and Western blot. The data was statistically analyzed with SAS6.12 software package for one-way ANOVA. RESULTS: Cell viability of PDLCs significantly decreased when exposed to hypoxia in a time- and dose-dependent manner. Hypoxia induced the expression of HIF-1alpha,up-regulated the expression of Caspase-3. CONCLUSIONS: Hypoxia inhibits cell proliferation, which involves the expression of HIF-1alpha and Caspase-3, resulting in the production of the apoptosis. The results suggest that hypoxia may play a role in the induction and progression of chronic periodontitis. Supported by National Natural Science Foundation of China(Grant No.30801292), Shanghai Leading Academic Discipline (Grant No.S30206) and Research Fund for Excellent Young Teachers of Shanghai Municipal College and University (Grant No.JDY07059).