BACKGROUND: Both cyclodextrin high polymer and polyvinyl alcohol (PVA) have been widely applied as biomedical materials owing to their characteristics including no toxicity and good biocompatibility and mechanical property and have become important functional materials of biological drug manufacture and medication research.OBJECTIVE: To observe the drug controlled release property of β-cyclodextrin (β-CD) loaded onto PVA by the covalent bond and to investigate the possible mechanisms of action. DESIGN, TIME AND SETTING: An observational experiment was performed at the Laboratories of Applied Chemistry, College of Science, Northwestern Polytechnical University, and College of Chemistry & Chemical Engineering, Xiangyang Normal University in 2008. MATERIALS: PVA (Tianda Experimental and Chemical Plant, Tianjin, China), β-CD (Sanpu Chemical Engineering Co.,Ltd., Shanghai, China) and camptothecin (Modern Times Chemical Institute, Xi'an, China) were used in this study. METHODS: Mono-6-O-tosyl-β-CD and mono-6-formyl-β-CD were synthesized separately. Silylatedβ-CD was loaded onto polymer chain of PVA by acetalization to produce PVA containingβ-CD (PVA-β-CD) linear high polymer. The clathration between PVA-β-CD and camptothecin was observed. Drug-release content of PVA-β-CD membranes under different pH values was determined through the use of ultraviolet-visible spectrophotometer. MAIN OUTCOME MEASURES: Synthesis condition and drug release rate of PVA-β-CD. RESULTS: The best condition for synthesis of PVA-β-CD linear high polymer comprised reaction time 2 hours, temperature 70 ℃, and the mass ratio of mono-6-formyl-β-cyclodextrin to PVA not higher than 4:1. Experimental results regarding drug release revealed that PVA-β-CD promoted water-insoluble drug release owing to its clathration and solubilization. Withβ-CD content increasing, camptothecin release amount and release velocity had no significant change in pH 11 medium but increased greatly in pH 2 medium. CONCLUSION: As for compact PVA membrane, addition ofβ-CD possibly leads to pore formation, thus promoting water molecule infiltration and drug diffusion, beneficial to drug release, and simultaneously, the solubilization of β-CD plays an important role in promoting the release of insoluble drug.

Objective To explore the effects of psoralen (PSO) and long wave ultraviolet A (PUVA) on apoptosis and expression of Fas in HL-60,K562 and NB4 leukemia cells.Methods The cells were incubated with PSO in different concentrations irradiated with or without UVA.The changes of ultrastructure of cells were observed under the electron microscope.The expression of Fas gene was detected by fluorescent quantitation PCR.The apoptosis ratio and the expression of Fas protein were detected through the flow cytometry.The factorial design and analysis of variance were used to analyze the interaction among the factors.Results There were obvious ultrastructure changes about apoptosis in leukemia cells after treated with PUVA.PSO,UVA and PUVA all increased the apoptosis ratio and expression of Fas gene and protein,and the effects of PUVA were stronger than the other two (P

BACKGROUND:Occlusal scheme is the key of a successful complete denture, and how to choose a suitable occlusal scheme is a long-term problem for prosthodontists.
OBJECTIVE:To systematical y review the clinical effects of two occlusal schemes for complete denture.
METHODS:An electronic search of Cochrane Library, Medline/PubMed, EMBASE, CNKI, Wanfang and CBM databases were performed for clinical trials published before October 2013 using the key words of“complete denture”,“edentulous”,“occlusion”,”balanced”,“lingualized”,“anatomic”in Chinese and English. A manual searching of 11 relevant journals concerning oral medicine and reference lists of selected articles were conducted. Two reviewers independently extracted the data and assessed the quality of the included literature. Total y, 628 papers were retrieved.
RESULTS AND CONCLUSION:Only five articles met the inclusion and exclusion criteria. Of these five articles, one study showed lingualized occlusion dentures were more satisfactory than bilateral balanced occlusion dentures in denture retention (P<0.05);one study showed the lingualized occlusion exhibited lower scores for uncomfortable eating and avoiding particular foods (P<0.05), but higher scores for uncomfortable dentures than the bilateral balanced occlusion (P<0.05);one study showed the lingualized occlusion dentures have better masticatory efficiency and better protective role in alveolar bone than the bilateral balanced occlusion dentures (P<0.05);another two studies showed no significant differences in the overal satisfaction between lingualized occlusion and bilateral balanced occlusion dentures. These findings indicate that the lingualized occlusion is similar to bilateral balanced occlusion in the satisfaction of patients, masticatory efficiency, appearance and speech, but the lingualized occlusion dentures are better for severe alveolar bone resorption patients in terms of masticatory efficiency and better protection of alveolar bone.

Objective:To investigate the clinical efficacy of microscopic myringoplasty versus endoscopic myringoplasty in the treatment of tympanic membrane perforation caused by chronic suppurative otitis media. Methods:The clinical data of 91 patients with tympanic membrane perforation caused by chronic suppurative otitis media who received treatment in Jiaxing Second Hospital, China between February 2017 and March 2019 were retrospectively analyzed. These patients were divided into a control group ( n = 45) and an observation group ( n = 46) according to different surgery methods. The control group was given microscopic tympanoplasty, while the observation group was given endoscopic tympanoplasty under the otoendoscope. Results:Blood loss in the observation group was significantly lower than that in the control group [(7.2 ± 2.0) mL vs. (13.7 ± 3.1) mL, t = 11.912, P < 0.001]. Operation time in the observation group was significantly shorter than that in the control group [(59.4 ± 5.4) min vs. (91.5 ± 11.2) min, t = 17.474, P < 0.001]. Postoperative pain score in the observation group was significantly lower than that in the control group [(2.9 ± 0.7) points vs. (4.8 ± 1.3) points, t = 8.707, P < 0.001]. Hospital stay in the observation group was significantly shorter than that in the control group [(4.3 ± 1.0) d vs. (6.5 ± 1.5) d, t = 8.249, P < 0.001]. Pure tone hearing thresholds at 1, 2 and 4 kHz frequencies in the observation group were significantly higher than those in the control group (all P < 0.05). Patient satisfaction regarding the aesthetic effect of the surgical incision in the observation group was significantly higher than that in the control group [97.8% (45/46) vs. 77.8% (35/45), χ2 = 8.604, P = 0.003]. Conclusion:Endoscopic myringoplasty has the advantages including shorter operation time, less blood loss, lower degree of pain, better hearing improvement and higher patient satisfaction over microscopic myringoplasty in the treatment of tympanic membrane perforation caused by chronic suppurative otitis media.

[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.

OBJECTIVE: To explore the effects of psoralen (PSO) plus long-wave ultraviolet-A (PUVA) on apoptosis and expression of Fas ligand (FasL) in HL-60 leukemia cells. METHODS: The HL-60 cells were taken as the study objects and their apoptosis rates, ultrastructure changes and the expression of FasL were detected in order to observe the effects of PSO and ultraviolet-A (UVA) of wave length 360 nm. The factorial design and analysis of variance were used to analyze the interaction among the factors. RESULTS: PSO, UVA and PUVA all induced the apoptosis and the effects of PUVA were stronger than those of the other two. After HL-60 cells had been treated with PUVA, they all showed obvious ultrastructure changes due to apoptosis observed under the electron microscope. PSO, UVA and PUVA all decreased the expressions of FasL gene and protein. The effects of PUVA were stronger than those of the other two. CONCLUSIONS: PUVA can induce the apoptosis of HL-60 cells and the effects are stronger than those of PSO or UVA alone. The expression of FasL gene in HL-60 cells is down-regulated during the apoptosis induced by PUVA.

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.

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.

The finite element method was used for simulating the mechanical performance and fatigue safety of three different structures of Nitinol stent. According to the actual situation, after proposing reasonable assumptions and simplification, the geometry model and finite element model establishment, material mode selection and boundary condition setting are completed. The strain and fatigue life of different stent edges wide (omega) or strut angle (theta) are computed. The result can provide a valuable reference for the optimal design of stent.
Alloys ; Finite Element Analysis ; Prosthesis Design ; Stents

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.