BACKGROUND:Periodontal ligament stem cels are one of the ideal seed cels in periodontal tissue regeneration. Sources, biological characteristics and influential factors of periodontal ligament stem cels have been an issue of concern. OBJECTIVE:To review the biological characteristics and functional factors of periodontal ligament stem cels as wel as relevant research status and progress in regenerative medicine, and to discuss the relevant application prospect and existing problems, thereby providing theoretical and experimental basis. METHODS:PubMed and Wanfang databases were searched by the first author for articles related to differentiation and proliferation of periodontal ligament stem cels published from 2002 to 2015. The key words were “periodontal ligament stem cel, periodontal tissue, proliferation, differentiation” in English and Chinese, respectively. Finaly, 47 articles were included in result analysis. RESULTS AND CONCLUSION:Periodontal ligament stem cels have the ability of differentiating into fibroblasts, adipocytes, chondrocytes and cementum. Cel growth factors play an important role in the proliferation and differentiation of periodontal ligament stem cels. Fibroblast growth factor, vascular endothelial growth factor and insulin-like growth factor can promote the proliferation of periodontal ligament stem cels. Application of stem cel biofilm as a carrier material can effectively guide periodontal tissue regeneration. Isolation, culture and influential factors of periodontal ligament stem cels should be further improved. Combined application of stem cels, biofilms and growth factors is expected to achieve the desired periodontal tissue regeneration, which is the focus of future research.

Objective To observe the clinical effect of neuromuscular electrical stimulation combined with kinesitherapy on dysfunction after brachial plexus injury. Methods 60 cases with brachial plexus injury following dysfunction were divided into two groups. The experimental group (n=30) was treated with neuromuscular electrical stimulation combined with kinesitherapy. The control group (n=30) was treated with kinesitherapy. Two groups were assessed by the brachial plexus function evaluation standard before and 3 months after the treatment.Results Two group all improved 3 months after the treatment (P<0.05), while the experimental group was better than the control group (P<0.01). Conclusion Neuromuscular electrical stimulation combined with kinesitherapy is more effective to improve the function after brachial plexus injury.

Objective To evaluate the diagnostic value of 2D ultrasound (2DUS)-based composite score method and contrast enhanced ultrasound (CEUS) in differentiation between thyroid microcarcinomas and benign micronodules. Methods A total of 216 consecutive patients with 258 thyroid micronodules underwent 2DUS and CEUS examinations before thyroidectomy from June 2011 to October 2013. The scoring of each nodule was based on five 2DUS features including hypoechogencity, irregular shape, macrocalcification, and taller than wide in shape. Microcalciifcation was assigned as 2 points and the remaining features were assigned as 1 point. A composite score was ifnally given to each thyroid nodule ranging from 0 to 6 points. The sensitivity, specificity and accuracy of diagnosing thyroid microcarcinoma by 2DUS composite score method and CEUS were calculated. Results The histopathologic results of all 258 nodules were acquired, including 125 papillary microcarcinomas and 133 benign micronodules. Each nodule′s 2DUS compostie score was ranging from 0 to 6 points. The area of receiver operating characteristic (ROC) curve of 2DUS in diagnosing thyroid microcarcinoma was 0.81. The 2DUS composite score method predicted the thyroid microcarcinoma with sensitivity of 78.4%(98/125), speciifcity of 72.9%(97/133), accuracy of 75.6%(195/258), when the nodule with a score greater than or equal to 3 points was deifned as malignant. Thyroid micronodules′enhancement pattern were divided into 7 types, including early hypoenhancement, hypoenhancement, isoenhancement, hyperenhancement, local nonenhancement, nonenhancement, and ring margin ring enhancement. CEUS predicted thyroid malignant micronodules with sensitivity of 87.2%(109/125), specificity of 75.9%(101/133), and accuracy of 81.4%(210/258), when early hypoenhancement and hypoenhancement pattern was defined as malignant patterns. There were no differences in sensitivity, specificity, and accuracy between 2DUS cumulative score method and CEUS in diagnosing thyroid microcarcinoma (McNemar test, P=0.099, 0.608, 0.096). Conclusion Early hypoenhancement and hypoenhancement are CEUS characteristic enhancement pattern for thyroid microcarcinoma, CEUS has higher sensitivity, speciifcity in diagnosis than 2DUS composite score method, while there are no statistical differences.

Through comparing problem-based learning and lecture-based learning, the PBL teaching can improve the learning interest and self-learning ability of students and also can accomplish the task of teaching better.

The levels of IgG2b monoclonal antibodies against LD H-C4 in sera of mice bearing hybridoma backpack tumors secreting anti-LDH-C4-IgG2b were detected by quantitative ELISA． The accuracy between batches is 7.04%～l3.30 %, the intra-assay variation is 3.6l%～l0.20%． Standard curveof monoclonal lgG2b was well correlated (r=0.962　　884～0.996　　795)． The sensitivit y of the assay reach e dup to0.0l?mg/L． The present modified ELISA offers a reproducible, se nsitive, specific method in determination of antigen-specific IgG2b antibody in sera．

Objective To apply the binary Logistic regression model and evaluate the value of grey scale ultrasonography(US),ultrasond elastography(UE) and contrast-enhanced ultrasound(CEUS).Methods US,UE and CEUS were performed in 130 patients with 142 solid thyroid micronodules (the largest diameter less than 10 mm).Pathology was followed up as golden diagnosis criteria.A Logistic model on the basis of ultrasonographic features was obtained.A receiver operating characteristic(ROC) curve was used to assess the performance of Logistic model.Results Four ultrasonic indexes were finally entered into the Logistic regression model including microcalcification,acpect ratio,advanced CEUS mode and elasticity score.The percentage correction of prediction was 92.1％ (129/142),the area under the ROC curve was 0.944.Conclusions The multivariate analysis model of binary Logistic regression can describe and analyze the process of differential diagnosis of malignant and benign solid thyroid micronodules by ultrasonography,and select out the valuable indexes for differential diagnosis.

Objective To evaluate right ventricular (RV)systolic function in type-2 diabetes mellitus (T2DM)patients.Methods Fifty T2DM patients and fifty normal controls were included in the study and underwent echocardiographic examinations.The following parameters were measured:1 ) Right heart dimensions,pulmonary artery (PA)diameter,pulmonary acceleration time (AT)and PA systolic pressure (PASP);2)RV systolic function:RV fractional area change (RVFAC),tissue Doppler-derived tricuspid lateral annular systolic velocity (S'),tricuspid annular plane systolic excursion (TAPSE),longitudinal strain of six RV segments by 2-dimensional speckle tracking imaging (2D-STI);3 )RV diastolic function:E,A ratio of the tricuspid inflow spectrum (E/A),E,E'(peak early diastolic velocity of the tricuspid annulus) ratio (E/E');4)RV Tei index.Results Statistic analysis showed that T2DM patients had thicker RV walls,wider PAs and shorter AT than the control group (P =0.000,0.001 and 0.000),while their right heart chamber sizes and PASP remained unchanged.Among systolic parameters,absolute values of RV longitudinal strain at the lateral wall-mid (lat-m),septum-mid (sep-m)and septum-basal (sep-b)segments were significantly lower in the diabetic group than the control group (P =0.001 ,0.000 and 0.005),whereas strain of the other three RV segments and RVFAC,TAPSE.S'were not significantly different.Moreover, E/A,E/E'and Tei index were all significantly different between the two groups (P = 0.000,0.000 and 0.006),indicating declined diastolic and general function of RV in the T2DM group.Conclusions RV myocardial strain by 2D-STI is more sensitive in detecting RV systolic dysfunction than TAPSE,S' and RVFAC.Among the six segments of RV walls,lat-m,sep-m and sep-b are better locations for 2D-STI than the other three.

Objective To evaluate the role of real-time three-dimensional transesophageal echocardiography(RT-3D TEE)in left atrial appendage (LAA)occlusion.Methods Consecutive 10 atrial fibrillation (AF)patients (CHADS2 ≥ 2 )with high risk bleeding underwent LAA occlusion under the guidance of TEE.The LAA orifice shape and characteristics of lobes were assessed,the size of LAA with RT-3D TEE wee measured before closer implanation,and the position of the LAA occlusion device were evaluated by RT-3D TEE.The correlational analysis between LAA diameter and occluder size was conducted.Results Among 10 patients,the test results revealed 8 cases with complete LAA occlusion and 1 case with incomplete occlusion,and 1 case with failed occlusion.Five cases showed approximate round LAA ostium,and the other 5 showed approximate oval ostium.The average number of LAA lobes were 2.2±0.7. LAA ostium long diameter were larger by 3D TEE compared with 2D TEE[(21 .8±5.1)mm vs (20.8±4.1) mm],and ostium short diameter were smaller by 3D TEE compared with 2D TEE [(16.1 ± 3.0 )mm vs (1 7.0±2.6)mm],however there were no significant differences between 2D and 3D TEE measurements,and the mean ostium diameter and LAA depth were comparable between two methods.LAA ostium long diameter,short diameter,average diameter and LAA depth assessed by 3D TEE and 2D TEE showed good correlation with occluder diameter (3D TEE:r =0.719,0.690,0.791 ,0.71 1 ,and P =0.029,0.040,0.01 1 , 0.032,respectively;2D TEE:r = 0.887,0.894,0.932,0.896,and P = 0.001 ,0.001 ,0.000,0.000, respectively).LAA occlusion device position assessed by RT-3D:6 cases with appropriate position, acceptable position with 2 cases,and 1 case with malposition.Conclusions RT-3D TEE can play important role in evaluating the morphology of LAA,accurately judging LAA ostium shape and size and position of the occlusion device.

Objective To explore the imaging features of papillary thyroid microcarcinoma(PTMC) with real time contrast-enhanced ultrasound.Methods One hundredand forty-three cases with 149 thyroid nodules(no diffuse lession) were divided into two groups according to the diameter size(group 1,＜0.5 cm;group 2,0.5-1.0 cm) and examined by contrast-enhanced ultrasound during preoperation.Pathology was followed up as golden diagnosis criteria.Results Seventy-five benign tumors and 74 PTMC were confirmed by pathology.There were significant differences in echoes homogeneity between benign and malignant tumors in group 2(W =1 029.5,Z =-5.524,P =0.000) but no in group 1(W =933.0,Z =-1.738,P =0.082).And nonhomogeneous enhancement were showed in most PTMC in group 2.But most PTMC showed homogeneous enhancement in group 1.Conclusions Contrast-enhanced ultrasound is valuable in diagnosis of PTMC with the diameter size of 0.5-1.0 cm.

A method was developed for determination of 12 kinds of phosphate compounds in water and sediment by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) coupled with solid phase extraction (SPE) and ultrasonic extraction.The water samples were concentrated by HLB solid-phase extraction (SPE) column and eluted twice with ethyl acetate, ultrasonic solvent extraction for sediment samples and then repeated the operation of water samples after diluted with deionized water.The sample were separated on a ZORBAX Eclipse Plus C18 (150 mm × 2.1 mm, 3.5 μm) column by a gradient elution with 0.2% formic acid aqueous solution and methanol as the mobile phase.Ion mode analysis was monitored by high performance liquid chromatography mass spectrometer (MRM).The target compounds were quantified by external standard method.At the spiked levels (0.05, 0.1 and 0.5 μg/L), the average recoveries of 12 kinds of OPEs in water samples ranged from 66.4% to 115%, except for TMP (28.5%-47.8%) and TEHP (22.4%-73.8%).The relative standard deviation RSD (n=3) was 0.5%-9.09%, and the method quantification (MOQ) was 0.001-0.05 μg/L, However at the spiked levels of 5, 10 and 50 μg/kg, the average recoveries of 12 kinds of OPEs in sediment samples ranged from 65.4% to 120.0%, except for TMP (35.7%-44.9%) and TCEP (31.2%-48.9%).The relative standard deviation RSD (n=3) was 0.01%-9.54%, and the MOQ for sediment was 0.02-2.0 μg/kg dw.Based on the above methods, the detection and analysis of the targets in the water and sediments samples of Taihu Lake were carried out.The results showed that the concentrations of ΣOPEs were 0.1-1.7 μg/L and 8.1-420 μg/(kg dw), respectively.