BACKGROUND:When bone cement solidifies fast,the bone cement consistency will be decreased.resulting in difficulty in molding.DESIGN,TIME AND SETTING:Open experiment,performed in the Laboratory of Department of Materials,Lanzhou Jiaotong University between March 2005 and August 2006.gelatin were mixed with citric acid to produce hardening liquid.Then bone cement power and hardening liquid were mixed to form a paste,I.e.,bone cement.METHODS:Setting time of bone cement was determined using a Vicat apparatus.The compressive strength of bone cement at different proportions was tested using MTS-810 material tester.After 2 months of physiological saline soaking at 37℃.the microstructure of solidified bone cement was observed using scanning electron microscope.MAIN OUTCOME MEASURES:Setting time and compressive strength of bone cement,pH value of hydrated bone cement and the microstructure.RESULTS:After adding chitosan and gelatin in the hardening liquid.the consistency of the concoction obviously increased,the setting time became a little longer and the water-resistance of samples was enhanced.therefore the samples could be easily molded.But the compressive strength of the bone cement decreased a little.The pH value of the hydrated bone cement increased gradually with time and was close to the pH value of physiological saline at hour 24.The compressive strength of bone cement was achieyed at 24 hours and it almost did not change after 48 hours.the drawback of ceramic HA,including sintering and difficulties in shaping.It has the characteristics of simple-producing,easy application and low heat energy.

AIM: To prepare α-tricalcium phosphate (α-TCP)/calcium polyphosphate (CPP) fiber and to study the feasibility of CPP fiber to reinforce calcium phosphate bone cement composites. METHODS: Firstly,α-TCP powder was synthesized using chemical sediment method. Secondly, the α-TCP was mixed with CPP fiber according to different contents and lengths. Finally, bone cement was tempered with firming agent. Solidification time and mechanical property of the samples were measured. Microstructure of hardened sample was observed with scanning electron microscope. RESULTS: When the amount of CPP fibers was 10% and the length was 2 mm, the compressive strength reached 62.5 MPa and the rupture strength reached 12.4 MPa. Scanning electron microscope suggested that CPP fibers with great associativity were well distributed in bone cement. After immersing in Ringer fluid for two months, the CPP fibers did not biodegrade obviously and still had certain function to increase strength and toughness. CONCLUSION: To a certain extent, the CPP fiber can increase strength and toughness of bone cement. Furthermore, α-TCP/CPP composites have good mechanical properties and biocompatibility.

Objective To observe the effect of enteral nutrition therapy on metabolic status and adiponectin levels in elderly patients with metabolic syndrome (MS) complicated with nonalcoholic fatty liver disease (NAFLD).Methods 92 elderly hospitalized patients with mild to moderate non-alcoholic fatty liver disease underwent enteral nutrition (EN,n=46) and total parenteral nutrition (TPN,n=46) for 2 months.Body mass index,triceps skin-fold thickness,waist hip ratio,serum high-molecular weight (HMW) form of adiponectin,fasting blood glucose,postprandial 2-hour blood glucose,glycosylated hemoglobin,plasma insulin,alanine aminotransferase,aspartate aminotransferase,γ-glutamyltransferase,total bilirubin,direct bilirubin,total cholesterol,triglyceride,low density lipoprotein cholesterol,high density lipoprotein cholesterol,the blood pressure and liver ultrasound test were detected.The insulin resistance (HOMA-IR) was used to assess insulin resistance.Results In pre-versus post-treatment,serum level of HMW adiponectin [(6.8 ± 4.0) μg/L vs.(7.1 ± 3.9) μg/L,P ＞ 0.05 in enteral nutrition],and [(6.8 ± 3.5) μg/L vs.(5.0 ± 1.1)μg/L(P＜0.05)] in parenteral nutrition were found.The significantly decreased body mass index in the obese patients (P＜0.05),significantly improved values of 2-hour blood glucose,glycated hemoglobin,liver function,triglycerides,low-density lipoprotein cholesterol levels (all P＜0.05),and no obvious change in HOMA-IR were found after two months of enteral nutrition treatment.There were no significant changes in indicators mentioned above in TPN group after 2 months of treatment.Conclusions Enteral nutrition therapy can improve the glucose metabolism,lipid metabolism,the non-alcoholic fatty liver disease and body mass index,affect the level of adiponectin in the elderly patients with MS and NAFLD.It is vital to body metabolism.

Mucosa-associated lymphoid tissue lymphomas are a distinct subgroup of non-Hodgin's lymphoma with a particular clinicopathologic behavior.It is the most common type of extranodal low-grade B cell lymphoma.This type of lymphoma tends to appear in patients with a history of autoimmune disease or chronic inflammatory disorders.These indolent lesions usually remain localized for long periods and often respond to local therapy.The most common site of MALT lymphoma is the stomach.This article reviews clinical features and management of MALT lymphoma,emphasizing on gastric MALT lymphoma.

Objective:To analyze the failure factors in root canal therapy(RCT)by analysis of the failed cases.Methods:215 teeth of 206 patients were analyzed according to former treatment records,clinical examination,pretreatment radiographs,and root canal exploration during endodontic retreatment.Results:67.9% of failed teeth showed apical radiolucency,12.6% showed under-filled canal material without apical radiolucent area,and 8.4% involved coronal leakage.When examined with X ray,84.2% of teeth indicated under-filling,and most canals of premolars and molars had poor taper.Most missed root canals were found in maxillary first molars and premolars.18.1% of teeth had complications such as ledge and apical transportation.Conclusions:The factors associated with RCT failure involve cleaning,obturation and poor seal of root canal system resulted from inadequate shaping.Coronal leakage and missed canals also contribute to the endodontic treatment failure.

Objective To compare the clinical outcomes of 2 different catheter ablation strategies for patients with chronic atrial fibrillation(CAF).Methods One hundred and thirty four consecutive patients(77 males,mean age 56.8?12.3 yrs)were randomized into 2 groups of different catheter ablation strategies.All the patients suffered from frequent attacks(more than 3 times per month),drug refractory and symptomatic CAF.One group received circumferential pulmonary rein ablation(CPVA group,n=68)and the other group received complex fractionated electrogram ablation additional to CPVA(CPVA+CFEA group,n=66).All ablation was guided by 3 dimensional mapping system(CARTO).Follow-up ECG,Holter and clinical outcomes of the 2 groups within 6 months after the procedures were analyzed.Results The baseline characteristics were comparable between the 2 groups.The mean procedure time in the CPVA+CFEA group was longer than that in the CPVA group but the mean fluoroscopy time between two groups had no significant difference.After the first procedure,60%of patients in the CPVA group and 77% of patients in the CPVA +CFEA group were free from symptomatic atrial tachycardia without any use of antiarrhythmic drugs for at least 3 months(P

Objective To evaluate the safety and effectiveness of catheter ablation for atrial fibrillation(AF)therapy guided by 3-D mapping systems.Methods Eight hundred cases(482 male,mean age 62.1?15.6 years)were enrolled.AF was paroxysmal in 611 cases,and persistent in 189 cases.The mean left atrium diameter was 38.4 9.2 mm.Ablation was guided by EnSite-NavX in 260 cases and by CARTO in 540 cases.Circumferential pulmonary vein isolation(CPVI)was performed for paroxysmal AF,and CPVI combined with complex fractionated atrial electrograms(CFAEs)and mitral isthmus ablation was applied for persistent AF.Every case received oral anticoagulation with warfarin and class IC and class III antiarrhythmic drugs for 1 to 3 months.ECG and Holter were applied every month during follow-up.Results Seven hundred and ninty-five cases underwent the procedure successfully,with the mean procedural time 161 33 min and fluoroscopic time 17 13 min.PV isolation was achieved in 96.5% of cases for left-sided PVs,and in 98.6% of cases for right-sided PVs.Radiofrequency application terminated paroxysmal AF in 90 out of 98 cases.AF recurred in 137 cases within 2 weeks post-ablation,and subsided in 103 cases during subsequent follow-up.Fifty-seven cases underwent re-ablation and 6 cases required third ablation.Persistent AF was terminated in 30 cases(16.1%)and was converted to atrial tachycardia in 15 cases(8.1%)by CPVI.For patients receiving CFAEs ablation,persistent AF was terminated in 20 cases(10.8%)and was converted to atrial tachycardia in 23 cases(12.4%).AF recurred in 78 cases(41.9%)early after ablation and 65 cases underwent re-ablation(10 cases received third ablation).Atrial tachycardia/flutter developed in 104 cases(13.1%)after ablation,and remitted in 68 cases.Atrial tachycardia/flutter was mapped and ablated in 30 cases,and was eliminated in 23 cases.Complications:Cardiac tamponade developed in 5 cases,requiring pericardiocentesis in 3 cases and surgical repair in 2 cases.PV stenosis was present in 6(0.7%)cases,TIA in 1 case,cerebral embolism in 2 cases,mesentery artery embolism in 1 case,hemothorax in 1 case and pneumothorax in 1 case.There were femoral artery pseudo-aneurysm in 3 cases and femoral artery-vein fistula in 1 case.All the patients were cured by conservative therapy.During a mean follow-up of 16.2?5.7 months,550 cases(9.4% of them received re-ablation and 11.5% received antiarrhythmic drugs)with paroxysmal AF and 159 cases(34.9% of them received re-ablation and 28.5% received antiarrhythmic drugs)with persistent AF were free of atrial tachyarrhythmias recurrence.Conclusion Catheter ablation guided by 3-D mapping systems were safe and effective for AF therapy.CPVI alone was enough for paroxysmal AF treatment,while CPVI combined with CFAEs and isthmus ablation were preferable for persistent AF treatment,and re-ablation were needed in 40% of the patients to improve effectiveness.

Objective To analyze the distribution of key target sites(KTSs) during initial circumferential pulmonary vein isolation(CPVI) for atrial fibrillation(AF) and during re-ablation.Methods Forty eight cases(30 males,average age 54.3?10.2 years) with recurrent AF were enrolled.AF was paroxysmal in 24 cases and persistent in 24 cases.Re-ablation was performed 37.2?7.4 days after initial CPVI.KTS was defined as the target sites where pulmonary vein potentials(PVPs) delayed,conduction sequence changed,PVPs slowed down or PV isolated during ablation.Circumferential pulmonary vein(PV) lesions were divided eaqually into 8 segments.KTSs were analyzed during initial CPVI and re-ablation.Results One hundred and forty five KTSs were identified during initial CPVI.The mean KTSs per case were 3.02?1.08,compared with 1.58?1.09 during re-ablation,P

Objective To analyze the prevalence of complications following catheter ablation for atrial fibrillation and to describe the characteristics of transition of complications.Methods From October 2004 to December 2008,2 260 cases(1 265 males)with atrial fibrillation(AF)were admitted for catheter ablation.AF was paroxysmal in 1 449 cases and chronic in 811 cases.Circumferential pulmonary vein isolation(CPVI)was carried out alone for paroxysmal AF and in combination with fractionated electrograms ablation for chronic AF.Complications were summarized and analyzed by dividing the whole duration into three sections:Year 2004-2006,Year 2007 and Year 2008.Results Complications occurred in 61 cases(2.70%).Cardiac tamponade developed in 11 cases,embolism in 18 cases,pulmonary vein stenosis in 14 cases,and vessel access related complications in 18 cases.In Year 2004-2006,cardiac tamponade occurred in 5 cases,cerebral embolism in 3 cases,mesenteric artery embolism in 1 case,pulmonary vein stenosis in 6 cases,and vessel access related complications in 6 cases.In Year 2007,cardiac tamponade occurred in 4 cases,cerebral embolism in 3 cases,Mesenteric artery embolism in 1 case,pulmonary vein stenosis in 4 cases,and vessel access related complications in 5 cases.In Year 2008,cardiac tamponade occurred in 2 cases,cerebral embolism in 7 cases,mesenteric artery embolism in 3 cases,pulmonary vein stenosis in 4 cases,and vessel access related complications in 7 cases.There was no significant difference in the prevalence of complications among three sections.The prevalence of cardiac tamponade was lower in Year 2008 compared with that in the other two sections,P=0.5.However,the prevalence of embolism was higher in Year 2008 compared with that in the other two the sections,P=0.2.Conclusion It is safe to perform catheter ablation for the treatment of AF.Despite the improvement of technical skills,the prevalence of severe complications such as cardial tamponade,pulmonary vein stenosis or stroke did not decrease.

The brains from four newborns were used in this study. After continuous artery-vein injection with coloured materials, the brains were embedded in nitrocellulose. and coronal sections of 500?m, 100?m and 30?m in thickness were prepared in alternative and successive sequence. The 500?m sections were cleared in wintergreen oil and mounted, and the 100?m and 30?m sections were stained with thionin. The diameter and density of capillaries in thalamus and its adjacent structures were measured by means of Leitz MPV-Tasplus multifunction image analyser. All the data were dealt with variance and correlation analysis statistically. The capillary density of the thalamus and its adjacent structures varied obviously. The value in putamen, cellular layers of lateral geniculate body, anterior thalamic nucleus and subthalamic nucleus was the highest; while the value in dorsomedial nucleus, ventral lateral nucleus, pulvinar nucleus, ventral posterior lateral nucleus, lateral posterior nucleus, centromedian nucleus, medial geniculate body, ventral anterior nucleus and internal medullary lamina was the intermediate; however, the value in internal capsule and fibrous layers of lateral geniculate body was the lowest. The capillary diameter of ventral anterior nucleus and internal capsule was the widest; that of putamen and cellular layers of lateral geniculate body was the smallest; the rest was the intermediate. In the same measured structures, negtive correlation was shown between the capillary diameter and density.