BACKGROUND:Our previous studies have shown that the poly(hydroxybutyrate- co-hydroxyvalerate) - sol-gel bioactive glass (PHBV-SGBG) has good biocompatibility and promote bone tissue repair, but its specific role in periodontal tissue regeneration has not been investigated. OBJECTIVE:To investigate the periodontal regenerative effects of a PHBV-SGBG scaffold in beagle dogs. METHODS:Alveolar bone defects (5 mm×5 mm) were surgicaly created bilateraly at the buccal side of the mandibular third and fourth premolars of four beagle dogs. PHBV-SGBG scaffold was randomly filed in the defects as experimental group and nothing was put into the contralateral as control group. Histological and scanning electron microscopy observations, cone-beam CT evaluation and the Ca/P concentration ratio analysis were processed at 2, 4, 8 and 12 weeks after surgery. RESULTS AND CONCLUSION:After surgery, the height of the regenerated tissue increased with time in both groups, and the regenerated tissue height in the experiment group was higher than that in the control group (P < 0.05). At 12 weeks after surgery, the Ca/P concentration ratio of the experiment group was close to that in the normal tissue (P > 0.05), but higher than that of the control group (P < 0.05); the histological observation showed that the regenerated tissue of the experimental group was close to the normal tissue, and the regenerated tissue of the control group tended to be mature, with a smal amount of new blood vessels. Under the scanning electron microscope, no scaffold structure was visible in the experimental group with the presence of bone lacuna at 8 weeks after surgery, while in the control group, there was no bone lacuna and obvious osteoblasts; at 12 weeks after surgery, the structure of the regenerated tissue of experimental group was more regular and close to the normal tissue with no remarkable osteoblasts, and in the control group, the regenerated tissue was disordered, with several cavity. These results show that the PHBV-SGBG scaffold can enhance periodontal bone regeneration effectively.

[Objective] The biocompatibility between SGBG/PHBV and human PDLC were investigated to provide a basis for the choice of the scaff material of periodontal tissue engineering.[Methods] Human PDLC were cultured using tissue-explant technique.Seeding on 96 wells plate,9 wells for one group,Four different concentrations (100％,75％,50％,25％,0％) of maceration extract of SGBG/PHBV were added into the culture plantsafter 48-h cell seeding,the grades of the cytotoxicity of SGBG/PHBV was evaluated by MTT assay.Human PDLC cultured in vitro were collected and seeded on the three-dimensional scaffolds of SGBG/PH-BV,the cellular morphology and cell growth on the scaffolds were observed and photographed by scanning electronic microscope.HumanPDLC seeded on the three-dimensional scaffolds of SGBG/PHBV in the experimental group,and human PDLC seeded by DMEM in the control group,after 12-,24-,and 48-h cell seeding,got 27 simples for each group,and the affection of the SGBG/PHBV on cell secretory function was observed by spectrophotometry which assayed the biochemical indexes ALP in supinate.[Results] The grades of the cytotoxicity of SGBG/PHBV were 0 and 1.It was displayed that human PDLC adhered and proliferated well on the scaffold of SGBG/PHBV under the scanning electronic microscope.The significant difference of ALP in supinate between the experimental group and the control group (P ＜ 0.05).[Conclusions] SGBG/PHBV had no cytotoxicity to human PDLC.SGBG/PHBV is potential to further study as the scaffolds of periodontal tissue engineering since it displayed the satisfactory biocompatibility with human PDLC.

BACKGROUND:The morphological structure of nanofiber scaffold which fabricated by electrospinning technique is similar to the natural extracelular matrix, which provides a good microenvironment for cel growth and proliferation, and can also enhance cel adhesion, migration, proliferation and differentiation. OBJECTIVE: To observe the biocompatibility of double-layer poly(L-lactic acid) electrospun nanofiber scaffold and human periodontal ligament cels. METHODS: Electrospinning technique was used to prepare double layers poly(L-lactic acid) electrospun nanofiber scaffold. The toxicity of different concentrations of (100%, 75%, 50%, 25%) double-layer poly(L-lactic acid) electrospun nanofiber scaffold extracts to human periodontal ligament cels was evaluated by MTT assay. The double-layer poly(L-lactic acid) electrospun nanofiber scaffold was co-cultured with human periodontal ligament cels. The cel adhesive capacity in early stage was determined by MTT assay. The growth of cels on the scaffold was observed by scanning electron microscopy. RESULTS AND CONCLUSION: Different concentrations of double-layer poly(L-lactic acid) electrospun nanofiber scaffold extracts did not create any toxicity to human periodontal ligament cels. After co-culture for 2, 6, 24 hours, human periodontal ligament cels were poorly adherent onto the double-layer poly(L-lactic acid) electrospun nanofiber scaffold. After 7 days of co-culture, human periodontal ligament cels adhered wel on the loose surface of scaffold, maintained the original shape, stretched wel, and interconnected processes were observed; on the dense surface of the scaffold, multi-layer cels were observed. The cels showed fusiform or polygonal appearance and were connected together. These results demonstrate that the double-layer poly(L-lactic acid) electrospun nanofiber scaffold has good biocompatibility with human periodontal ligament cels.

This study is to explore the active ingredients of traditional Chinese medicine rhubarb with antiproliferative activity on hypertrophic scar fibroblasts (HSF). Rhubarb was extracted with Soxhlet extraction method by different polar solvents. MTS method was used to screen rhubarb solvent extracts (25 microg x mL(-1)) with anti-proliferative activity on HSF, and flow cytometry was used to detect their influences on cell cycle. Then, the active ingredients were analyzed by HPLC. The components with high activity were identified by UPLC-Q/TOF and verified by HE staining. The results showed that the ethyl acetate extract of rhubarb had higher anti-proliferative activity (P < 0.01), increased significantly the proportion of cells in G0/G1 phase (P < 0.01), and reduced the proliferation index (PI) (P < 0.01). The main active ingredients were anthraquinones. The results of confirming experiment showed that emodin, rhein and gallic acid could inhibit cell proliferation in a dose-dependent manner. In conclusion, the ethyl acetate extract of rhubarb showed anti-proliferative activity on HSF, and the anti-proliferative ingredients might be anthraquinones.

AIM:Chronic exposure to elevated levels of free fatty acids (FFAs) in type 2 diabetes patients is toxic to pancreatic β-cells.Thioredoxin (Trx)-interacting protein (TXNIP), an endogenous Trx-inhibiting protein, is up-regulated by glucose and is a critical mediator of hyperglycemia-induced β-cell apoptosis in diabetes.However, the effects of FFAs on TXNIP are unknown.In this experiment we observed the effect of palmitate on TXNIP expression in cultured INS-1 islet cells and the pathways involved were analyzed meanwhile.METHODS:After the full basis of preliminary experiment of incubating INS-1 cells with palmitate at different concentrations for different time, INS-1 islet cells were cultured with 0.5 mmol/L palmitate for 24 h.TXNIP expression, cell apoptosis, and expression of transcription factors related to TXNIP transcriptional regulation were determined.RESULTS:Compared with control group, the expression of TXNIP at mRNA and protein levels in palmitate group was significantly up-regulated (P<0.01).Cleaved caspase-3/caspase-3 ratio was increased in palmitate group (P<0.05), and the apoptosis of the INS-1 cells was also significantly increased (P<0.01).Palmitate enhanced the phosphorylation of nuclear factor-κB (NF-κB) (P<0.01), and the NF-κB inhibitors, PDTC and SN50, both blocked the palmitate-induced up-regulation of TXNIP expression.CONCLUSION:Saturated fatty acid palmitate enhances the expression of TXNIP.The mechanism of palmitate-induced TXNIP expression may be associa-ted with the increase in NF-κB phosphorylation.

BACKGROUND:At present, col agen as a material in periodontal tissue engineering has some disadvantages such as poor mechanical strength and rapid degradation speed. Col agen combined with chitosan can improve above-mentioned problems.
OBJECTIVE:To evaluate the biocompatibility of a novel chitosan-col agen scaffold in vitro.
METHODS:Cytotoxicity of the extract of chitosan-col agen scaffold in different concentrations (100%, 75%, 50%, 25%) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Human periodontal ligament cel s at 4-6 passages were cocultured with the chitosan-col agen scaffold. Cel growth on the scaffold was observed. Changes in alkaline phosphatase activity were detected in periodontal ligament cel s before and after coculture.
RESULTS AND CONCLUSION:The novel chitosan-col agen scaffold was made up of double layers with one dense layer and another loose layer. The grade of the cytotoxicity of the scaffold was from 0 to 1. Scanning electron microscope and histological observation demonstrated that cel s grew wel on the chitosan-col agen scaffold;the dense layer could prevent cel s to migrate into the scaffold. There were no significant differences in alkaline phosphatase activity in human periodontal ligament cel s before and 24 hours after combined culture (P>0.05). Alkaline phosphatase activity in human periodontal ligament cel s was greatly higher at 48 and 72 hours after combined culture compared with that before culture (P<0.05). Above results indicated that the novel chitosan-col agen scaffold has a good biocompatibility and barrier function, and potential as a scaffold for periodontal tissue engineering.

Pdx-1, an important transcription factor highlighting in the early pancreatic development,islet functions and pancreatic disorders, needs to be more investigated in zebrafish, and siRNA is still seldom applied in zebrafish embryo-related research.Our aim was to explore the role of pdx-1 in pan-creatic development of zebrafish embryos by using siRNA approach. Microinjection, reverse tran-scriptase-PCR (RT-PCR), in situ hybridization and immunofluorescent staining were used in this re-search, and the morphology of the islet in normal zebrafish embryos, and in those treated with the siRNA specific to pdx-1 (siPDX-1) or siGFP was observed and compared. The expression of pdx-1 was detected in the stages of 1-cell, 2-cell, 4-cell, 8-cell, 16-cell, 16-hour by RT-PCT. The in situ hy-bridization and immunofluorescent staining results showed that siPDX-I disturbed the formation of the islet in zebrafish embryos. Pdx-1 played multiple roles in maintaining the phenotype of the islet during embryogenesis in zebrafish.

Alzheimer's disease (AD) is the most common neurodegenerative disorder, which features mainly with memory impairment as the initial symptom of progressive loss of cognitive function. Its main pathological changes include senile plaques and neurofibrillary tangles. The pathogenesis of AD is still unclear, though it may be connected with aging, genetic factors and environmental factors. Among these, aging and environmental factors can be modified by epigenetics. In this paper, advances in the study of epigenetic mechanisms related to the pathogenesis of AD are reviewed.
Alzheimer Disease ; genetics ; psychology ; Animals ; Cognition ; Epigenesis, Genetic ; Humans

Stimulator of interferon genes (STING) is an important factor in the auto-immune response of our bodies.Considering the mechanism of activating CD8+ T cells after the activation of STING protein, the combination of STING agonists and immune checkpoint inhibitors for the treatment of tumor immunotherapy has good clinical application prospect.In this paper, the research progress of molecular types, mechanism of action and structural modifications of STING agonists were reviewed.The developing tendency were outlined to provide some references for further investigation.

Objective To analyze the etiology and risk factors of central venous catheter (CVCs) infections, and to explore the prophylaxis and treatment for catheter-related infections. Methods A retrospective study was conducted. The patients with CVCs admitted to intensive care unit (ICU) of Qianfoshan Hospital Affiliated to Shandong University from January 2000 to December 2016 were enrolled. The gender, age, catheter data and microorganism culture results of all patients were collected. The infection rate and the incidences of CVCs infection per 1 000 catheter days were calculated. The risk factors of CVCs infection were analyzed by Logistic regression. Results 1 160 patients were enrolled in 17 years [male 915, female 245, age 7-98 years, mean (71.8±17.5) years]. The incidences of CVCs infection per 1 000 catheter days were descended every 3 years (cases/1 000 days: 21.87, 24.50, 19.95, 12.64, 16.34, 12.40, χ2=38.851, P = 0.000). Of the 1 160 patients, 375 were positive for catheter culture, and 397 strains were cultured, among which 173 strains (43.58%) were Gram negative (G-), 130 strains (32.74%) of Gram positive (G+), and 94 strains of fungi (23.68%). Non-fermenting bacteria (Pseudomonas aeruginosa 11.59%, Acinetobacter baumannii 8.82%) was predominant in the G- bacteria, followed by Enterobacteria (Klebsiella pneumoniae 8.06%, Escherichia coli 2.02%); Staphylococcus spp. (Staphylococcus epidermidis 11.84%, Staphylococcus aureus 5.29%) was the main species of G+bacteria; the main fungi were Candida tropicalis (9.07%) and Candida albicans (5.79%). The catheter infection rate of internal jugular vein, femoral vein and subclavian vein were 36.07% (22/61), 35.52% (119/335), 30.63% (234/764) respectively (χ2=2.275, P = 0.099), the incidence of catheter infection of three vein insertion sites per 1 000 catheter days were 18.00, 17.71, 17.08 cases/1 000 days respectively (χ2= 0.034, P = 0.714). The mean placement time of infected CVCs in situ was longer than that of non-infected CVCs (days: 20.80±11.68 vs. 17.64±10.77, t = 4.417, P = 0.000).The positive rate was lowest during 1-7 days of indwelling time (19.87%, 30/151). The infection rate was increased with long indwelling time. The positive rate was 44.44% (68/153) as indwelling time was over 30 days. The infection rate was significantly positively related to indwelling time (χ2= 22.849, P = 0.000). Multiple Logistic regression analysis showed that the infection risk of femoral vein catheter was increased [odds ratio (OR) = 1.362, 95% confidence interval (95%CI) = 1.030-1.801, P = 0.030] as compared with that of subclavian vein catheter; the infection risk was increased with long indwelling time (OR = 1.306, 95%CI = 1.177-1.480, P = 0.000). Conclusions G- are the major pathogens of CVCs infection. Femoral vein catheter and long indwelling time are the risk factors of CVCs infection.