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OBJECTIVE@#To investigate the role of autophagy in lipopolysaccharide (LPS)-induced apoptosis of murine odontoblasts.@*METHODS@#Murine odontoblasts (mDPC-23 cells) were treated with 5 μg/mL LPS for 6, 12 and 24 h, and the changes in cell viability was examined using CCK8 kit and cell apoptosis was detected by TUNEL staining. The changes in the protein levels of LC3, Beclin1, Atg5, AKT, p-AKT, mTOR and p-mTOR were detected using Western blotting. The effect of 3-MA treatment for 24 h on LPS-induced apoptosis of mDPC-23 cells was evaluated by detecting the expressions of apoptosis-related proteins caspase-3 and Bax using Western blotting.@*RESULTS@#Stimulation with LPS for 6 and 12 h did not cause significant changes in the proliferation or apoptosis of mDPC-23 cells, but LPS treatment for 24 h significantly suppressed cell proliferation (@*CONCLUSIONS@#LPS stimulation induces autophagy to promote apoptosis of mDPC-23 cells, and suppression of autophagy attenuates LPS-induced apoptosis. Autophagy may play an important role in the injury of inflamed pulp tissues.
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Animais , Camundongos , Apoptose , Autofagia , Lipopolissacarídeos/farmacologia , Odontoblastos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de SinaisRESUMO
Objective To investigate the mechanisms of tigecycline nonsusceptibility in carbapen-ems-resistant Acinetobacter baumannii ( CRAB) strains in order to provide a theoretical basis for a reasonable use of antibiotics and the control of nosocomial infection .Methods Susceptibility testing of 120 non-dupli-cate CRAB strains to tigecycline was performed by using the broth microdilution method .Minimal inhibitory concentrations ( MIC) of tigecycline against the A.baumannii strains were determined by using the broth mi-crodilution method before and after exposing the strains to Carbonylcyanide-m-chlorophenylhydrazone (CCCP), which was the efflux pump inhibitor .Polymerase chain reaction (PCR) was used to amply the ef-flux pumps genes including adeB, adeJ, adeG, abeM, adeE, adeRS, tetX and tetX1.The real-time PCR was performed to measure the expression of efflux pumps genes including adeB, adeJ, adeG, abeM and adeE.Results A total of 120 CRAB strains were collected including 13 (10.8%) tigecycline non-suscep-tible A.baumannii (TNAB) strains and 107 (89.2%) tigecycline susceptible A.baumannii (TSAB) strains.The MIC values of tigecline to the 120 CRAB strains were in a range of 0.25 μg/ml to 8 μg/ml. The adeR and adeJ genes were detected in 90.0%and 92.5%of the 120 CRAB strains, respectively.The positive rates of adeB, adeS, adeG and abeM genes among the 120 CRAB strains were all 94.2%.None of the three genes including adeE, tetX and tetX1 were detected .The mean expression levels of adeB and adeJ in TNAB strains were respectively increased by 18.69 folds and 5.46 folds as compared with those in sensi-tive strains.No significant increase in the expression of adeG and abeM genes was observed in TNAB strains . A 4-fold decrease in the MIC was observed in 8 out of 13 TNAB isolates treated with 10 μg/ml of CCCP .The CCCP could partially reverse the resistance pattern of tigecycline .Conclusion The efflux pump sys-tems of adeABC and adeIJK rather than the abeFGH and abeM systems might play an important role in reduc-ing the tigecycline susceptibility in carbapenems-resistant A.baumannii strains.
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Objective To investigate the mechanism of carbapenems resistance in Serratia marces-cens strains isolated from Wenzhou and their epidemiological characteristics.Methods 147 non-duplicated Serratia marcescens isolates were collected from the First Affiliated Hospital of Wenzhou Medical University during 2006 to 2012.The antimicrobial susceptibility test for all isolates was performed by using Vitek2 Compact to screen carbapenems-resistant Serratia marcescens strains.The minimum inhibitory concentrations ( MICs) of 10 commonly used antibiotics against carbapenems-resistant Serratia marcescens strains were de-termined by agar dilution method.The phenotypes of carbapenemase were analyzed by using the modified Hodge test.PCR analysis was used to detect the genes encoding carbapenemase, AmpC enzyme, efflux pump and outer membrane proteins.The changes of MICs before and after using CCCP efflux pump inhibitor were measured by agar dilution method.Outer membrane proteins were detected by SDS-PAGE.Carbapene-ms resistance genes were transferred from carbapenems-resistant Serratia marcescens strains to recipient strains by conjugation.The transconjugants were amplified by PCR and measured for MICs.Pulsed-field gel electrophoresis ( PFGE) was used to analyze homology among strains.Results 11 isolates resistant to car-bapenems were screened out from 147 Serratia marcescens isolates and all of them were resistant to penicil-lins, cephalosporins and ertapenem.10 out of the 11 isolates were both resistant to imipenem and meropen-em, but remained susceptible to fluoroquinolones and aminoglycoside.Among the 11 isolates, 10 carried blaKPC-2 gene, 1 carried blaIMP-1 gene, 8 harbored both blaEBC and blaMOX genes, 1 harbored both blaEBC and blaDHA genes, and 1 carried blaEBC , blaMOX and blaDHA genes.No additional genes were identified by PCR.The MICs of imipenem to 7 isolates and the MICs of ertapenem to 3 isolates were respectively decreased by 4-64 folds and 8-256 folds after using CCCP.CCCP had no effects on the MICs of meropenem.Loss of outer membrane protein was not detected among the 11 isolates.The blaKPC-2 genes were successfully transferred from 7 isolates into recipient strains.The MICs against the transconjugants were higher than those against the recipient strains in varying degrees.PFGE analysis demonstrated that 8 out of 11 Serratia marcescens strains belonged to one clonotype.Conclusion KPC-2 carbapenemase played an essential role in carbapenems re-sistance in Serratia marcescens strains isolated from Wenzhou.Attention should be paid to the clonal spread of KPC-2 and its horizontal transmission in Wenzhou.
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Objective To evaluate whether the timing of maternal hypoxia during pregnancy could myocardial remodeling in adult offspring.Methods Twenty-four pregnant rats were assigned to the maternal hypoxia group starting from the early period of pregnancy (G1,day 3 to 21 of pregnancy),the group starting from the middle period of pregnancy (G2,day 9 to 21 of pregnancy),the group starting from the late period of pregnancy (G3,day 15 to 21 of pregnancy),or the control group (G0).Six rats were included in each group.Rats in the maternal hypoxia groups (G1,G2 and G3) were subjected to hypoxia for 3 hours in a low pressure cabin with an oxygen concentration of (10± 1) ％.Systolic blood pressure,wet weight of the left ventricle normalized for body weight (left ventricular weight/body weight,LVW/BW),diameter of cardiomyocytes,and the expression levels of collagen Ⅰ and collagen Ⅲ were measured in adult male offspring at the age of 3 and 5 months.One-way ANOVA and SNK test were used for statistical analysis.Results Maternal hypoxia from day 3 to 21 of pregnancy induced higher systolic blood pressure in male offspring at the age of 3 months and 5 months [3 months:G1 (122.0± 11.7) mmHg,G0 (108.3±9.5) mmHg,F=2.97; 5 months:G1 (128.5±7.9) mmHg,G0 (114.6±-10.0) mmHg,F=3.17,both P＜0.05].Maternal hypoxia also led to a higher LVW/BW ratio (G1 1.99±0.03,G0 1.80±0.02,P＜0.05),and increased collagen Ⅰ and collagen Ⅲ expression (collagen Ⅰ /β-actin:G1 1.76±0.07,G0 0.48±0.04,P＜0.01; collagen Ⅲ /β-actin:G1 0.68±0.05,G0 0.34±0.03,P＜0.01) in adult male offspring at the age of 5 months.Maternal hypoxia from day 9 to 21 of pregnancy induced a higher LVW/BW ratio (3 months:G2 2.15 ± 0.05,G0 1.98 ± 0.02,P＜0.05; 5 months:G2 1.96±±0.05,G0 1.80±0.02,P＜0.05),and increased collagen Ⅰ and collagen Ⅲ expression (3 months:collagen Ⅰ /β-actin G2 0.98±±0.02,G0 0.87±0.02,P＜0.05; collagen Ⅲ /β-actin:G2 0.87±±0.01,G0 0.82±0.01,P＜0.05; 5 months; collagen Ⅰ /β-actin G2 1.61±0.05,G0 0.48±0.04,P＜0.01; collagen Ⅲ / β-actin:G2 0.61 ±0.04,G0 0.34±0.03,P＜0.01) in male offspring at the age of 3 months and 5 months,but did not affect systolic blood pressure.Maternal hypoxia from day 15 to 2l did not have any effect.The diameter of cardiomyocytes in male offspring was not significantly different between the groups.Conclusions Maternal hypoxia during different periods of pregnancy has different effects on cardiac structure in adult rat offspring.Maternal hypoxia started in early or mid-pregnancy leads to cardiac collagen deposition without an increase in myocyte size in adult offspring,which may be independent of the change in blood pressure.
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Objective To investigate the efficiency and safety of intervention with flexible bronchoscope under general anesthesia by using laryngeal mask in patients with severe tracheal stenosis induced respiratory failure.Methods A total of 16 in-patients with respiratory failure caused by severe tracheal stenosis admitted from September 2009 to March 2012 were retrospectively reviewed.A comprehensive bronchoscopic intervention for the complete patency of airway was successfully performed with various techniques such as cryotherapy,electrocautery,balloon dilatation,and implantation of selfexpanding metal stents under genersl anesthesia by using laryngeal mask.The efficiency of comprehensive bronchoscopic intervention and dyspnea score were evaluated by chest CT scan and bronchoscopic examination before and after the treatment.Data were expressed as ((x-)± s).Paired t test was used for statistical analysis of the data.Results The degrees of tracheal stenosis and dyspnea score before and after intervention were (85.0±8.4)％ vs.(20.9±7.6)％ (P＜0.01) and (3.9±0.3vs.2.4±0.5,P＜ 0.01),respectively.There were no life-threatening complications occurred including massive haemorrhage.Conclusions It is an effective and safe technique to resolve the tracheal stenosis-induced respiratory failure with intervention by using flexible bronchoscope under general anesthesia with laryngeal mask,and it is a promising interventional treatment for clinic application.
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Objective To evaluate the relationship between the heart diastolic function and pulse wave velocity in patients with diabetes mellitus.Methods Fifty-five patients with diabetes mellitus underwent echocardiogram exam,PWV,and BNP determination.Patients were divided into two groups according to the results:the group with normal heart diastolic function(n =33)and the group with abnormal heart diastolic function( n =22).Another 30 healthy volunteers served as control group.The values of PWV were compared.between the three groups.The relationship between E/E' and PWV,BNP and PWV were evaluated with correlation analysis.Results The PWV value of abnormal heart diastolic function group was significantly higher than that of other two groups.PWV was positively correlated with E/E'and BNP ( r =0.58,P ＜ 0.05 ; r =0.63,P ＜ 0.05).Conclusion PWV is associated with the heart diastolic function.PWV can serve as an important factor to predict abnormal heart diastolic function in patients with diabetes mellitus.
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Objective To study the clinical ralue of electromyogram in te sting peripheral nerves in diabetic patients and study the factors affecting per ipheral nearopathy. Methods FBG, 2HBG, HbA1c and electromyogram of nerves peronaeus communis and superficialis were measured in 2 3 diabetic patients. Result The result of electromyogram accord ed with clinical symptoms. Diabetic patients with neurological symptoms had higher voltage, prolo nged time limit of light contract peak value, and increased multiphase electric p otential compared with those without neurological symptoms (p