Objective To evaluate the importance of wide canal sign (increased anteroposterior diameter of the spinal canal at L5) in the MR diagnosis of lumbar isthmic spondylolisthesis.Methods One hundred cases of bilateral isthmic spondylolisthesis at L5 confirmed with conventional radiography and/or CT were randomly collected.Another age and sex matched 100 cases without spon-dylolisthesis were collected as control group.The sagittal canal diameters at the L1 and L5 levels were measured and analyzed for all 100 cases of bilateral isthmic spondylolisthesis and 100 control subjects.For each group,the sagittal canal ratio(defined as the maxi-mum anteroposterior diameter of the canal at L5 level divided by the diameter of the canal at L1 )was calculated and compared be-tween the two groups ,and anylyzed with ROC curve.Results The mean midline sagittal anteroposterior diameter was (22.3 ± 1.34)mm at L5 in patients with lumbar isthmic spondylolisthesis,and (18.8±1.57)mm in the control subjects.The sagittal canal ratio was 1.32 in the isthmic spondylolisthesis group and 1.12 in the control subjects,which was different significantly.ROC curve illustrated that the sagittal canal ratio 1.25 was a most meanful point with 88% sensitivity and 90% specificity.Conclusion The sag-ittal canal ratio at L5 is bigger than 1.25 meaning abnormally increased sagittal canal diameter (wide canal sign),which specifically indicates the presence of bilateral pars interarticularis defects.Using this sign can help to make correct MR diagnosis and differential diagnosis of isthmic spondylolisthesis .

Diagnostic Errors ; Humans ; Pneumoconiosis ; diagnosis ; Scleroderma, Systemic ; diagnosis

Objective:To establish a new method to detect Amp C?-lactamase by PCR. Methods:The amp C and amp D gene fragments of E. cloacae were amplified by the amp C and amp D primers to detect Amp C ?-lactamase, especially the enduring and highly productive enzymes. Results:Totally 193 of 214 strains of E. cloacae were positive for amp C gene , implicating most strains of E. cloacae had the ability to produce the enzyme. Sixteen of the 193 strains (amp C positive) were negative for amp D genes, implicating these 16 strains could produce the enduring and highly productive enzymes. The results were confirmed by cefoxitin three-dimensional test. Conclusion:The new method to detect Amp C ?-lactamase, especially the enduring and highly productive enzymes,by amp C and amp D primers is a rapid and accurate method.

Objective To evaluate clinical and CT features of the 4 th lumbar vertebral spondylolisthesis (L 4DS ) as well as CT value in its diagnosis. Methods CT features of 36 cases of L 4DS were observed and interarticular distance (IAD) and facet joint angle (FJA) were measured and compared with control group.Results Patients with L 4DS mostly were over 40 years old. CT features included degenaration, spondylolisthesis and spinal canal stenosis. IAD and FJA were significantly narrowed. Conclusion CT axial scans combined with plain films,CTM and MPR clearly shows basic changes of L 4DS , providing useful details for clinical management. Narrow posterior vertebral part are important factors leading to L 4DS.

Objective To evaluate the computed tomography (CT) characteristics of cardiovascular involvement in Beheet syndrome. Methods Eleven patients with clinically diagnosed Behcet syndrome were studied retrospectively from July 1995 to December 2007. Electron beam CT or 64-slice helical CT scanner was used and CT characteristics were reviewed. Results Eleven patients were diagnosed according to the criteria reported by the international study group for Behcet syndrome. Of them, 4 patients presented with aortic valve prolapse (2 patients with mitral valve prolapse), false aneurysm of right coronary artery was demonstrated in 2 patients, false aneurysm of left subclavian artery, aortic aneurysm and penetrating ulcers, aortic arch false aneurysm, aortic dissection, pulmonary embolism and interatrial scptum aneurysm in 1 case, respectively. Conclusion CT is a very useful method for the diagnosis and foUow-up of Behcet syndrome.

BACKGROUND: Human pulp tissue has been known to be less, and exhibit poor tolerance to enzymatic digestion and less adherent cells after step-by-step digestion of trypsin and collagenase, thereby often leading to a failure of passage. Only several kinds of dental pulp cells with poor activity can be obtained by the tissue explant-collagenase digestion. OBJECTIVE: To investigate human dental pulp cells cultured in vitro by tissue explant method. DESIGN, TIME AND SETTING: A cytological observation was performed at Heping Campus and School of Stomatology, Jilin University from 2005 to 2007. MATERIALS: Healthy young human teeth extracted for orthodontic correction or impaction. METHODS: Pulp tissue from the third molar teeth was collected, cut into small blocks with a size of 1.0 mm×1.0 mm×0.5 mm under the infiltration of small amount of Dulbecco's modified eagle's medium, and then transferred into a 6-well plate containing culture medium for incubation in a 5% CO2 and saturated humidity atmosphere at 37 ℃. During the process of incubation, pulp tissue was adjusted at a density of 3-6 blocks/well, with an equal spacing of 0.5 cm and the 6-well plate was kept inverted. Three hours later, the 6-well plate was turned over to make tissue blocks adhering to the plate wall. Culture was continued after addition of 2 mL of culture medium. Culture medium was renewed every 4-6 days. After 6-15 days, cells emigrated from the edge of tissue blocks and call outgrowth appeared around each tissue block. When cells closed to confluency, a digestion procedure of 2.0-3.0 minutes (0.25% trypsin and 0.02% ethylenadiamine tetraacetic acid) was followed by passage culture at a proportion of 1: (2-3) in 25 mL of culture flasks. Purified fibroblast-like cells were gradually obtained from primarily cultured cells by repeated digestion and passage. MAIN OUTCOME MEASURES: Cellular morphology was identified by immunohistochemistry; secreted dental pulp cells were determined using alkaline phosphatase activity; the growth curves of human pulp tissue cells were depicted by MTT assay. RESULTS: Under an inverted phase contrast microscope, the obtained dental pulp cells were primarily typical fibroblasts with a long-shuttled appearance, well-rounded call body, uniform cytoplasm, round or oval nucleus, and clear nucleolus. Immunohistochemistry results showed call surface vimentin-positive, pan cytokeratin-negative, and alkaline phosphatase-posltive These cells were decreased after culturing 1 day, were slightly increased after 2 days, entered the logarithmic growth period and were markedly increased after 4 days, entered a platform period after 8 days, and began to decrease again after 9 days. The whole growth curve of cells appeared in "S" shape.CONCLUSION: The dental pulp cells isolated from human pulp tissue by tissue explant method can effectively proliferate end retain a poody differentiated state in vitro.

Objective To improve the classroom environment and students' learning effect and in-novation of classroom teaching mode. Method We took stomatology students of Grade 2012 (control group, 60 people) and Grade 2013 (experimental group, 69 people) as research subjects, and in the control group, the traditional teaching method was used, while the experimental group was based on the mixed mode of the flipped classroom. By comparison of the result of questionnaire survey and final examination between the experimental group and control group, we made clear the difference between blended classroom teaching and traditional classroom teaching. SPSS 16.0 was used for statistical analysis and the data was made t test and rank sum test, and the result was showed by rate and (x±s). Result The classroom performance of the control group was (14.78±4.27), and the experimental result was (14.49±4.49), in the experimental group, the internal and external performance of the experimental group was (22.19±7.21), the experimental result was (7.12±1.33). By comparison of the result of examination between the experimental group (49.01±7.28) and control group (46.32 ±7.44), medical immunology test scores were significantly different (P<0.05), and the experimental group was better than the control group. It showed that the mixed teaching model had more advantages in improving the academic performance. The results of questionnaire survey showed that flipped classroom teaching was better than traditional classroom teaching in ability training which included self learning ability (68.18%, 45 people), analysis and problem solving skills (68.18%, 45 people), team work and communication skills (56.06%, 37 people), ability of retain knowledge (46.97%, 31 people), however students who liked and accepted this new teaching model only accounted for about 30.00%. Conclusion Inte-gration of flipped classroom mode with traditional mode will enhance the students' learning efficiency and achievements, as well as promote students' ability.

Objective To observe short-term rapid atrial electrical activation on atrial size and atrial systolic function. Methods Twelve anesthetized mongrel dogs were underwent insertion of a transvenous lead at the right atrial appendage and subjected to 5 hours of rapid right atrial pacing at 450 beat/min. Acoustic quantification(AQ) waveform on biatrial was recorded before and after 5 hours pacing with AQ technique. All measurements were made in sinus rhythm. Results After 5 hours rapid right atrial pacing, end systolic volume(ESV) of both left and right atrial enlarged significantly from ( 5.92 ? 1.51 )ml to ( 7.27 ? 1.86 )ml,from ( 3.13? 0.71 )ml to ( 3.58 ? 0.73 )ml, respectively; but biatrial function decreased markedly,left and right atrial ejection fraction decreased from ( 51.03 ? 9.45 ) to ( 38.23 ? 10.52 ),from ( 36.76 ? 5.36 ) to ( 30.71 ? 7.97 ), respectively. However, left atrial ESV enlarged more than right atrial (by 23 vs 8,P

Background and purpose:Colorectal cancer (CRC) is a malignancy which is the third incidence and the fourth mortality in the worldwide. The main reason for the development of CRC is that the changes of genetic and epigenetic causes the tumor suppressor gene methylation silencing. This study aimed to investigate the plasma and stool GATA5 gene promoter methylation was detected in clinical diagnosis of CRC. Methods: To collect the paired plasma and stool specimens of 34 cases of healthy and 43 cases of patients with CRC. Methylation speciifc PCR (MSP) was respectively detected the GATA5 gene methylation levels of GATA5 gene in plasma and stool. And then separately analyzed their correlations with clinical and pathological parameters in gastric carcinoma. Results: The result of MSP showed that GATA5 gene promoter methylation rates in plasma and stool of CRC patients were 60.74%, 76.60%, respectively, were higher than those of healthy persons (6.47%, 32.35%). And the differences were statistically signiifcant (P=0.006 7, P=0.000 2, respectively). GATA5 gene methylation rates in plasma of CRC patients were closely related to clinical stage (P=0.000 5) and lymph node metastasis(P=0.020), while GATA5 gene methylation rates in stool of CRC patients had no signiifcant with clinical and pathological parameters. Conclusion:Detection of faecal GATA5 gene methylation level and supplemented plasma GATA5 gene methylation level can become a simple, non-invasive, sensitive and speciifc method for clinical diagnosis of CRC.

Objective To evaluate two kinds of practical CT three-dimensional volumetric measurement techniques in assessing atrial septal defects (ASDs) for transcatheter device closure.Methods Retrospective assessment of 50 consecutive patients who underwent ASD closure was conducted.Cardiac CT was performed in them before planned transcatheter ASD closure and postoperative chest radiograph was performed in both posteroanterior and lateral view.Coronary CT angiography was made for the detection of coronary artery disease,and three-dimensional reconstruction of ASD was conducted for determination of the defect size in the GE-workstation.Two kinds of practical CT three-dimensional volumetric measurement techniques,one named CT virtual endoscopy assisted volumetric measurement (CTVE) and another called axial sequence assisted volumetric measurement(CTAS),were used to calculate the major axis and the minor axis of the ASD respectively.Thus,the dimensions of the Equivalent Circle were derived,with circunference and area equal to the elliptic ASD according to the formulation (D =√b4/a2 + a2-b2).The ASDs occluder (ASO) dimension was measured in the lateral chest radiograph,and this postoperative occluder-waist size (POS) value was regarded as the gold standard for the measurement of ASD.The results were compared between CTVE and CTAS,and the correlations were evaluated between them and the gold standard.Results The differences in the major dimensions (-9.05 mm,t =-6.60,P ＜ 0.05),minor dimensions (-4.86 mm,t =-4.39,P ＜ 0.05) and Equivalent circle dimensions (-7.65 mm,t =-6.40,P ＜ 0.05) of ASD between CTAS and CTVE were statistically significant.Though the CTAS cannot provide the en face views of ASDs,the Equivalent Circle dimensions measured by CTAS(22.48 ± 5.59) mm was correlated well with POS (27.07 ± 6.83)mm (Y =1.14X + 1.39,r =0.94,P ＜ 0.01),and a good correlation was found between this Equivalent Circle dimensions and ASO size (Y =1.02X + 6.84,R2 =0.78,r =0.88,P ＜ 0.05).The correlation between the Equivalent Circle dimensions measured by using CTVE (30.13 ± 9.27) mm and POS was poor (Y =0.30X + 17.94,r =0.41,P ＜ 0.01),though it can provide the en face views of ASDs.Conclusion CTVE and CTAS are two complementary techniques of assessing ASDs for transcatheter device closure.