BACKGROUND:Hydrothermal condition of oral environment has an effect on the mechanical properties of dental core materials.
OBJECTIVE:To evaluate effect of water storage on the weight change rates and flexural properties of three dual-cure core buildup composite resins.
METHODS: Rectangular specimens (25 mm×2 mm×2 mm) were prepared from three dual-cure core buildup composite resins (LuxaCore Smartmix Dual, Para core and Clearfil DC Core). Specimens were stored in distiled water at 37℃ for 0, 1 day, 1, 2, 3 weeks and 1 month, respectively, weighted and then subjected to three-point bending test in a universal testing machine.
RESULTS AND CONCLUSION: Weight change rates of the three composite resins increased with immersion time; at the same immersion time, weight change rates of three composite resins ranked as the folowing order: LuxaCore Smartmix Dual > ParaCore > Clearfil DC Core. The flexural strength of LuxaCore Smartmix Dual decreased with immersion time. The flexural strength of ParaCore showed no significant change during 3 weeks immersion (P > 0.05), while it showed a significant decreasing after 1 month immersion (P < 0.05). There was no significant change on the flexural strength of Clearfil DC Core in the whole immersion process(P > 0.05). The flexural modulus of LuxaCore Smartmix Dual showed a decreased trend in the whole immersion process, but it showed that there was no significant change during the first 2 weeks(P > 0.05), while a significant decrease occurred after 3 weeks and 1 month (P < 0.05). Compared with original specimens, the flexural modulus of ParaCore and Clearfil DC Core showed a decreased trend, but this change was not significant (P > 0.05); the flexural properties of three composite resins showed a fluctuant decreased trend along with weight changes increased. To sum up, Clearfil DC Core showed the best water resistance among three composite resins.

[ABSTRACT]AIM:Toinvestigatetheeffectsofmechanicalstretchontransientoutwardpotassiumcurrent(Ito), inward rectifier potassium current ( IK1 ) and action potential duration ( APD) of cultured neonatal rat atrial myocytes . METHODS:Neonatal rat atrial myocytes were isolated and cultured on silicone sheeting with or without stretch for 24 h. The silicone membrane area was increased by 12%in stretched group.The cells without stretch served as control .Ito, IK1 and APD were recorded by the technique of whole-cell patch clamp.RESULTS:Compared with control group, Ito density in stretched myocytes was significantly reduced [(1.6 ±0.4) pA/pF vs (12.1 ±2.9) pA/pF, P<0.01], whereas IK1 density was increased [(-10.8 ±0.8) pA/pF vs (-8.8 ±0.9) pA/pF, P<0.01].The APDs at 50%and 90%levels of repolarization ( APD50 and APD90 ) in the stretched cells were obviously decreased than those in non-stretched cells [(10.5 ±1.4) ms vs (15.5 ±2.4) ms, (30.0 ±2.8) ms vs (56.3 ±3.6) ms, P<0.01].CONCLUSION: Stretch stimulation leads to the reduction of Ito density, the increase in IK1 density and the shortness of APD in cultured rat atrial neonatal myocytes , which may contribute to atrial electrical remodeling induced by pressure overload .

Objective To observe the effects of stromal cell-derived-factor-1(SDF-1) on the function of endotheli?al progenitor cells(EPCs)of peripheral blood in patients with diabetes, and to discuss the effects of PI3K/AKT signaling path?way on the role of SDF-1 in EPCs. Methods The peripheral blood samples (30 mL) were collected in 10 diabetes patients (DM group) and 10 healthy controls (HC group). (1) The 100μg/L SDF-1 was added in intervention group. EGM-2MV was added in non-intervention group. The Boyden chamber and in vitro angiogenesis kit were used to analyze the migration and in vitro angiogenesis of EPCs. (2) Cultured EPCs were divided into blank control group, 1μg/L SDF-1 group, 10μg/L SDF-1 group, 100μg/L SDF-1 group, pure AMD3100 group and 100μg/L SDF-1+AMD3100 group. AKT protein expression lev?els of endothelial progenitor cells were detected by Western blot assay in each group. Results (1) Without intervention with SDF-1, EPCs’migration and angiogenesis ability were lower in DM group than those in HC group. After intervention with SDF-1, the migration and angiogenesis ability were enhanced in two groups, but the increased level was higher in DM group than that of HC group. (2) Under the same concentration, AKT protein expression level was significantly lower in DM group than that in HC group (P<0.01). AKT protein expression levels were increased with the increased levels of SDF-1 in DM group and HC group (P<0.05). AKT protein expression was significantly lower in 100μg/L SDF-1+AMD3100 group than that of 100μg/L SDF-1 group (P<0.05). Conclusion SDF-1 can increase the chemotactic migration and angiogenesis ability of EPCs in peripheral blood, especially for patients with diabetes. The effects of SDF-1 on EPCs were related to the PI3K/AKT signaling pathway.

Objective: To explore the role of angiotensin receptor type I (AT1)-calcineurin (CaN) signaling pathway in transient outward potassium ion channel (Ito) remolding in hypertrophic atrial myocytes of neonatal rats. Methods: 1 day old neonatal rats’ atrial myocytes were isolated and the cells were divided into 4 groups:①Control group, normal cells were cultured for 24 h,②Stretching group, the cells were cultured for 24 h with mechanical stretching to induce hypertrophy,③Telmisartan group, the cells were treated by telmisartan at 1 μmol/L for 1 h, then cultured for 24 h and ④Cyclosporin-A (CsA) group, the cells were treated by CsA at 0.25 μg/ml for 1 h, then cultured for 24 h. The ratios of protein/DNA in myocytes were compared between Control group and Stretching group, cell hypertrophy was deifned by mRNA expression of atrial natriuretic peptide (ANP). Ito changes were detected by whole-cell patch clamping technique, proteins expressions of Kv4.3 and CaN A subunit were examined by Western blot analysis. Results: Compared with Control group, Stretching group showed obviously decreased Ito density and Kv4.3 protein expression, while increased CaN A protein expression; Compared with Stretching group, the above effects were reduced in Telmisartan group and CsA group. Conclusion: AT1-CaN signaling pathway was involved in the regulation of Ito channel remodeling in hypertrophic atrial myocytes of neonatal rats.

BACKGROUND:Specific down-regulation of interleukin 1 beta (IL-1β) may al eviate the pain behaviors effectively after peripheral nervous injury. Compared with smal interference RNA (siRNA), short hairpin RNA (shRNA) could inhibit the expression of target gene more stably and efficiently. However, simple shRNA could not enter target cel s to down-regulate target gene efficiently. Adenovirus vectors have wide host range, high infection efficiency and stable expression in host cel s.
OBJECTIVE:To construct recombinant adenovirus vector expressing shRNA targeting IL-1βgene and detect its effect on the expression of target gene.
METHODS:Three siRNAs were designed on the basis of the nucleotide sequence of IL-1βobtained from NCBI and then three shRNAs (shRNA1, shRNA2 and shRNA3) were synthesized. The annealed shRNA product and adenovirus vector pHBAd/U6/GFP digested by BamH I and EcoR I were connected to construct the recombinant adenovirus vector shuttle plasmid expressing shRNA targeting IL-1β. After sequencing, HEK 293 cel s were co-transfected by the shuttle plasmid and skeleton vector, and three recombinant adenovirus vector expressing shRNA targeting IL-1β(rAd/shRNA1, rAd/shRNA2 and rAd/shRNA3) were packaged and amplified. Rats H9C2 cel s were infected by recombinant adenovirus vector expressing shRNA targeting IL-1βand fluorescence microscope was used to observe the infection efficiency. The effect of recombinant adenovirus vector expressing shRNA targeting IL-1βon the expression of target gene was detected by western blot assay.
RESULTS AND CONCLUSION:The sequencing results showed that the sequences of three shRNAs adenovirus vector shuttle plasmid were consistent with the sequences of three designed shRNAs. rAd/shRNA1, rAd/shRNA2 and rAd/shRNA3 were constructed successful y. rAd/shRNA1, rAd/shRNA2 and rAd/shRNA3 could down-regulate the expression of IL-1βin rat H9C2 cel s and the down-regulation effect of rAd/shRNA2 was the most significant.

BACKGROUND: Laryngeal cancer can cause hoarse voice, dyspnea, and dysphagia, for which common surgical approaches or biotherapy hardly results when nodal metastases are present. Identification of the factors associated with laryngeal cancer metastases is a crucial task in the study of the malignancy, as such a revelation may help establish molecular markers for accurate assessment of metastases and develop biological agents to restrain the invasion and metastases.OBJECTIVE:To study the association of MMP-2, MMP-9, CD44v6, PCNA,nm23, VEGF, p53, Cath-D and E-cadherin with the metastasis of laryngeal cancer so as to provide evidence for clinical treatment of laryngeal cancer.DESIGN: An experimental study ofclinical specimens.PARTICIPANTS: All specimens of primary laryngeal cancer were obtained from patients receiving surgical treatment in the Department of Otolaryngology,Fourth Affiliated Hospital of Harbin Medical University from February 2002 to November 2003. Immunohistochemical examination of the specimens was conducted in the Third Affiliated Hospital of Sun Yat-sen University.INTERVENTIONS: The expressions of MMP-2, MMP-9, CD44v6, PCNA,nm23, VEGF, p53, Cath-D and E-cadherin were examined immunohistochemically in the specimens from 70 patients of laryngeal cancer. Logistic stepwise regression model was used to analyze the influence of the 9 clinicopathologic factors on lymph node metastasis.MAIN OUTCOME MEASURES: The expressions of MMP-2, MMP-9,CD44v6, PCNA, nm23, VEGF, p53, Cath-D and E-cadherin in laryngeal cancer specimens.RESULTS: Using the established equation to estimate lymph node metastasis, the frequency of lymph node metastasis was highest in patients with positive MMP-9 expression(Wald = 10. 350 1, P ＜ 0.05) . Lower E-cadherin expression was accompanied by higher frequency of lymph node metastasis, and nm23 expression in patients with lymph node metastases was significantly decreased in comparison with patients without metastases (Wald=6.189 6 and 6. 863 2, P ＜0.05).CONCLUSION: The expressions of MMP-9, E-cadherin and nm23 are useful indicators for preoperative prediction of lymph node metastasis of laryngeal cancer and provide valuable information for prognostic evaluation of the interventions.

BACKGROUND: Matrix metalloproteinases-7 (MMP-7) plays an important role in the invasion and metastasis of cancer and is related to prognosis of many carcinomas.OBJECTIVE: To investigate the significance of MMP-7 expression in the invasion and metastasis of laryngeal cancer and explore the relationship between MMP-7 expression and the prognosis of laryngeal squamous cell cancer (LSCC).DEGIGN: An open experimental study based on the cells.SETTING: Two otolaryngology departments of two university hospitals and one otolaryngology department of a municipal hospital.MATERIALS: The experiment was conducted in the Center Laboratory of Second Affiliated Hospital of Harbin Medical University from April 2002 to January 2003. The materials were laryngeal cancer and corresponding neighboring noncancerous tissues, MMP-7 antibody and immunohistochemical kit.METHODS: The expression of MMP-7 protein in 70 samples of paraffin-embedded LSCC and corresponding neighboring noncancerous tissues was detected with immunohistochemical technique. Reverse transcription-polymerase chain reaction(RT-PCR) and Western blot technique were used to examine the expression of MMP-7 in 35 frozen specimens of LSCC and corresponding neighboring noncancerous tissues.MAIN OUTCOME MEASURES: The relationship of MMP-7 mRNA expression with the invasion depth(T grade), neck nodal metastasis and prognosis of LSCC.RESULTS: Immunohistochemical staining of MMP-7 was observed in 77.1% (54/70) of cancer tissues and in 5.7% (4/70) of neighboring noncancerous tissues( P ＜ 0.01) . The mRNA expression of MMP-7 was detected in 74.3% (24/35) of cancer tissues and in 5.7% (2/35) of neighboring noncancerous tissues( P ＜ 0.01 ). The expression of MMP-7 was higher in T3-T4 group than that in T1-T2 group(P ＜ 0.01), and was positively correlated with nodal metastasis( P ＜ 0. 01 ). Western blot showed that both 28 ku (latent form of MMP-7) and 19 ku(active form of MMP-7)bands had close relationship with T grade and neck nodal metastasis. Kaplan-Meier survival curve showed that the group with high MMP-7protein expression had poorer prognosis than the group with weak or negative MMP-7 protein expression(Log-rank = 4. 755 9, 8. 951 3; P = 0. 029 2,0.002 8).CONCLUSION: MMP-7 is closely correlated with the invasion, metastasis,and prognosis of LSCC, and it may serve as a marker in estimating the invasive and metastatic potency and prognosis of LSCC.

BACKGROUND: The graft versus host disease (GVHD) is the main reason for allogeneic hematopeic stem cell transplantation (allo-HSCT) failure, and oral tolerization is a newly developed treating method.OBJECTIVE: To evaluate the inhibition effect of acute GVHD induced by feeding donors with recipient splenocytes orally before allo-HSCT in a murine model and to compare the immune tolerance with immunosupression agents currently used in clinical treatment.DESIGN, TIME AND SETTING: A randomized grouping design of contrast observation was performed at the Center Laboratory of School of Medicine, Southeast University in December 2008.MATERIALS: The male C57BL/6J(H-2~b) mice were served as donors, and the female (BALB/C) mice (H-2~d) were served as recipients.METHODS: The mice were prepared allo-HSCT/GVHD models, and divided into 5 groups, which received prevent scheme. ①Oral tolerization group: C57BL/6J mice were fed with BALB/C (H-2~d) splenocytes before the transplantation, with dose of 10 μg per time, 1 day interval, for 3 times. ②Rapamycin group: mice were intragastric administrated rapamycin from the 1st after transplantation with dose of 1.5 mg/(kg·d). ③Ciclosporin A+ methotrexate group: mice were intragastric administrated ciclosporin A with 1.5 mg/(kg·d), increased to 5 mg/(kg·d) when mice were recovered the gastrointestinal function, and received intragastric administrated 0.4 mg/(kg·d) methotrexate at days 1, 3, 6 and 11 after transplantation. ④Blank control group: no medication after transplantation. ⑤Irradiation group: mice were received no transplantation.MAIN OUTCOME MEASURES: The presence of GVHD after allo-HSCT, and the difference of immune tolerance index.RESULTS: Typical GVHD symptoms occurred in all mice after transplantation. In the blank control group, most mice dead at days 14-18 and the mortality was nearly 100%. Compared to the blank control group, the symptoms were significantly ameliorated and the median survival times were extended in the other 3 transplantation groups (P < 0.05). The pathological structures in liver, intestine and skin tissue in the oral tolerization group were significantly decreased. Flow cytometry assay showed that oral tolerization significantly increased the CD4~+/CD8~+ lymphocyte ratio and the percentage of the CD4~+CD25~+ cells.Oral tolerization also induced the decrease of GVHD-related cytokine level. The MTT results also showed that the immunologic tolerance in the oral tolerization group was significantly enhanced and the proliferation of lymphocyte was suppressed.CONCLUSION: Oral tolerization has obviously inhibitory effect towards GVHD after allo-HSCT, its exact mechanism may be due to the suppressing the proliferation of lymphocyte and increase the immunologic tolerance in recipients. Compared to the widely used immunosuppressive drugs, oral tolerization exhibits strong ability in ameliorating GVHD.

Objective: To investigate the correlation between nonalcoholic fatty liver disease(NAFLD)fibrosis score(NFS)and unstable plaques of carotid in elderly NAFLD patients. Methods: The clinical and carotid plaques data of 191 elderly(≥60 years old)admitted into our department between July 2016 and January 2018 were retrospectively collected.With NFS 0.676 as a cut-off point, the patients were divided into a liver fibrosis group(NFS ≥0.676, n=65)and a non-liver fibrosis group(NFS<0.676, n=126). Based on quartiles of NFS, the patients were divided into four groups: the Q1 group(NFS<-0.865, n=48), the Q2 group(-0.865≤NFS<0.100, n=48), the Q3 group(0.1≤NFS<1.070, n=47), the Q4 group(NFS≥1.070, n=48). The correlation of NFS with the property of carotid plaques was analyzed. Results: The detection rate of unstable carotid plaques was increased along with the increase of NFS(F=8.573, P=0.004). The detection rate of unstable carotid plaques was higher in the liver fibrosis group than in the non-liver fibrosis group(78.5% or 51/65 vs.60.3% or 76/126, χ²=5.883, P=0.015). Multiple logistic regression analysis showed that liver fibrosis(NFS≥0.676)was independently correlated with unstable carotid plaques(β=0.816, 95%CI: 1.110~4.607, OR=2.261, P=0.025)after adjusting for possible confounding factors including age, gender, diabetes mellitus, hypertension, total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein. Conclusions NFS is correlated with unstable carotid plaques in elderly NAFLD patients, and the higher NFS is the independent risk factor for unstable carotid plaques for elderly NAFLD patients with NFS higher than 0.676.We should pay more attention to the evaluation of unstable carotid plaques.

Objective This paper reviews the research context of the fear of cancer recurrence abroad, and presents the research hotspots and frontiers in this field, which will further provide references for the research of the fear of cancer recurrence in China. Methods Web of Science database was retrieved,the time of papers published, the number of publications and periodicals were analyzed.The Map drawing was accomplished with the help of Histcite software. Results Total 5322 effective literatures were investigated,most of the papers are published by the United States, Butow P was the high yield authors. and the core journal is "PSYCHO-ONCOLOGY". High frequency key words mainly concentrated on cancer, breast cancer, prostate cancer, quality of life, prognosis, chemotherapy (symptom distress and management). Conclusion In the aspect of fear of cancer recurrence, Europe and America are in a leading position, compared with the international level,there is still a gap in the field of FCR in China , the depth and breadth of research needs to be extended further, We should keep path with the international FCR research hotspot, to broaden our research scope and improve the quality of related research.