OBJECTIVEThis study aims to identify the crack tip stress intensity factor of the propagation process, crack propagation path, and the changes in the shape of the crack tip by the finite element method.

METHODSThe finite element model of dentino-enamel junction was established with ANSYS software, and the length of the initial crack in the single edge was set to 0.1 mm. The lower end of the sample was fixed. The tensile load of 1 MPa with frequency of 5 Hz was applied to the upper end. The stress intensity factor, deflection angle, and changes in the shape of the crack tip in the crack propagation were calculated by ANSYS.

RESULTSThe stress intensity factor suddenly and continuously decreased in dentino-enamel junction as the crack extended. A large skewed angle appeared, and the stress on crack tip was reduced.

CONCLUSIONThe dentino-enamel junction on human teeth may resist crack propagation through stress reduction.

Dental Enamel ; Dentin ; Humans ; Stress, Mechanical ; Tooth Fractures

Objective To study the clinical significance of a novel marker of platelet clumps count provided by hematology analyzer in differentiating true thrombocytopenia from EDTA-dependent pseudothrombocytopenia (EDTA-PTCP). Methods Samples from 65 cases of thrombocytopenia (including 15 EDTA-PCTP samples and 50 random samples of true thrombocytopenia) and 50 healthy controls were analyzed using hematology analyzers, and samples with low platelet counts were checked by replacing citric acid and using manual microscope observation to identify true thrombocytopenia from EDTA-PTCP. A novel marker of platelet clumps count was used to differentiate the two diseases for samples anficoagulated with EDTA or citric acid. Results In 65 patients with thrombocytopenia, platelet counts were (48±11)×109/L detected by automatic hematology analyzers. Fifty of 65 cases were true thrombocytopenia which showed low platelet counts [(48±10)×109/L by automated analyzer and (46±11)×109/L by manual assay]. No significance was observed between them (t=-1.26, P0.05). Platelet clumps counts were 86±15. No platelet clamps were detected under microscope. The other 15 cases were EDTA-PTCP [platelet counts were (48±12)×109/L and platelet clumps counts (840±184) were increased significantly by automated analyzer and using EDTA anticoagulant] which showed obviously platelet clumps and no less platelet counts under microscope. After replacing citric acid, platelet counts [(141±13)×109/L by automated analyzer and (134±17)×109/L by manual microscope assay] were increased significantly. No significance was observed between them (t=-1.29, P0.05). Platelet clumps counts (75±12) were decreased obviously compared with EDTA anticoagulant method (t=-6.82, P<0.001). No platelet clumps were detected under microscope. Conclusion Platelet clumps counts may be a useful clinical indicator for monitoring of platelet aggregates, especially for EDTA-PTCP caused by platelet clumping.

Objectives To monitor the residents prevalence of endemic arsenism in the disease affected areas in Inner Mongolia, so as to provide feasible suggestions for control of arsenism in the future. Methods Monitoring data were obtained from the Project of Endemic Disease Prevention Granted by Central Government in 2010 - 2012, and the conditions of arsenism patients from 38 endemic arsenic villages were analyzed among different year, age and gender. Results The detection rate of arsenism of the 38 surveillance villages was 7.38%(517/7 004) in 2010, 7.10%(482/6 784) in 2011 and 6.62% (431/6 514) in 2012. The arsenism patients of mild;moderate and severe cases from 2010 to 2012, accounted for 74.47% (385/517), 74.27% (358/482), 75.17% (324/431); 16.83% (87/517), 16.60% (80/482), 15.78% (68/431) and 8.7% (45/517), 9.13% (44/482), 9.05% (39/431), respectively. For skin lesions, the detection rates of keratosis, pigmentation and depigmentation from 2010 to 2012, were 8.08%(566/7 004), 7.90%(536/6 784), 7.77%(506/6 514);3.27%(229/7 004), 3.29%(223/6 784), 2.87%(187/6 514) and 6.68% (468/7 004), 6.63% (450/6 784), 5.82% (379/6 514), respectively, showed a declining trend. It also showed a declining trend with age, and the patients were mainly 40 years old people and older, and the highest detection rate was in the 60- 70 years old group[15.54%(143/920)、14.72%(135/917)、13.36%(136/1 018)]. For gender distribution, the detection rate of the three years was higher in male than female [male 8.24%(300/3 639), 7.99%(283/3 542), 7.71%(260/3 372);female 6.45%(217/3 365), 6.14%(199/3 242), 5.44%(171/3 142),χ2=8.24, 8.77, 13.54, all P〈0.01]. Conclusion There is no big change of arsenism conditions in 2010-2012, with a slight declining trend.

Objective To detect the expression of SALL4 in patients with acute myeloid leukemia (AML) and analyze its potential clinical significance. Methods Reverse transcription polymerase chain reaction and Real-time fluorescence quantitative reverse transcription polymerase chain reaction (FQ-RT-PCR) was used to examine SALLA expression in peripheral blood mononuclear cells (PBMCs) of 68 cases of AML including 36 cases in acute phase and 32 cases in remission phase, 30 healthy controls, Kasumi-1 cells and THP-1 cells. Then, flow cytometry, bone marrow smear and automated hematology analyzer were used to analyze the relationship between the SALL4 expression and blast cell counts in the bone marrow, peripheral white blood cell (WBC) counts, peripheral large unstained cell (LUC), CD34 in blast cells. Further, the change of SALL4 level during pre-chemotherapy, chemotherapy (2nd w to 3rd w) and remission were investigated in 5 AML cases. Results The level of SALL4 expression in patients with AML in acute phase [69.01 (17.20-120.28)] was 26-fold and 61-fold high compared with that in remission phase [2.64(1.35-5.41)] and in healthy control [1.14(0.50-1.62)] (Z=-6.48,-6.83,P<0.01). The level of SALL4 expression in remission phase was 2.3-fold high compared with that in healthy control (Z=-3.61 ,P<0.01). The expression level of SALL4 was decreased along with efficient chemotherapy in 5 AML cases in which SALL4 expression level was 79.74 (33.76-89.09), 7.19 (5.97-20.21) and 3.40 (1.44-15.53) during pre-chemotherapy, chemotherapy (2nd w to 3rd w) and remission, respectively. In groups of abnormal increased counts of blast cell, peripheral LUC% and CD34%, expression of SALL4 [33.82 (16.00-144.01), 30.70(23.75-72.50) and 56.25(23.79-153.81), respectively] were higher than that in groups of normal counts [2.74 (1.59-5.13), 5.71 (2.52-22.40) and 20.82 (14.03-55.12), respectively ] (Z=-4.64,-2.18,-3.66,P<0.01 or P<0.05). The expression of SALL4 in the group of increased WBC counts [89.26(23.75-154.34)] was higher than that in the group of normal WBC counts [3.86(2.03-6.01)] and the group of decreased WBC counts [6.66(2.51-17.06)] (Z=-4.91,-4.21,P<0.01). The level of SALL4 expression was positively correlated with blast cell counts in bone marrow and peripheral WBC counts (r=0.45,0.40,P<0.01). Conclusions FQ-RT-PCR method can be used successfully to detect the expression of SALL4,and the expression of SALLA may be useful to predict disease progression of AML.

Objective To investigate the mechanisms and effects of Sorafenib on cytotoxic sensitivity of allo-reactive natural killer(Allo-NK) cells against human multi-drug resistant nasopharyngeal carcinoma CNE2/DDP cells which expressing highly ATP-binding cassette superfamily G member 2(ABCG2)(abbr.as ABCG2HighCNE2/DDP cells).Methods ABCG2HighCNE2/DDP and Allo-NK cells were isolated by magnetic bead technique.The target cells were divided into 3 groups: a) treated group(ABCG2HighCNE2/DDP cells incubated with 10 ng/ml sorafenib for 4h);b) untreated group(conventionally cultured ABCG2HighCNE2/DDP cells);and c) control group(conventionally cultured K562 cells).Expression rates of ABCG2 in treated and untreated groups,and of five NKG2D-ligands(MICA,MICB,ULBP1,ULBP2,ULBP3) were evaluated by flow cytometry.The cytotoxic effects of NK cells against different groups of target cells were detected with LDH releasing assay.Results Expression rate of ABCG2 in isolated CNE2/DDP cells was 91.40%?2.32%.The purity of sorted CD3-CD16+CD56+ Allo-NK cells was 90% and higher.The expression rates of NKG2D-ligands(MICA,MICB,ULBP1,ULBP2 and ULBP3) in untreated group were 2.92%?0.33%,4.27%?0.33%,5.80%?0.62%,11.10%?3.15% and 7.75%?1.14%,respectively,which were remarkablely higher than that in treated group(10.38%?1.23%,10.68%?1.26%,11.62%?1.22%,43.24%?4.42% and 11.91%?0.88%,respectively,P

Objective To investigate the diagnostic value and monitoring application of anti-phospholipase A2 receptor antibodies ( PLA2R ) in patients with idiopathic membranous nephropathy ( IMN) .Methods A retrospective study was used .48 patients were diagnosed as idiopathic membranous nephropathy by puncturing kidney from January of 2013 to June of 2014 in the Hospital of Liaoning Traditional Chinese Medical University and Shengjing Hospital of China Medical University were included. 43 patients were diagnosed as non-idiopathic membranous nephropathy ( NIMN ).35 healthy volunteers were selected as control groups.Serum PLA2R were detected by indirect immunofluorescence.The intensity of antibodies fluorescence and the level of urine protein in 24 hours(24 h PRO) ,serum UREA ,serum CYSC, serum UA,GFR were compared in each groups.Measurement data was shown as mean ±standard deviation;Count data was shown as frequency or composition, t test andχ2 test were used as statistical method.Results (1) Among 48 cases with IMN,37 cases showed positive PLA2R (positive rate 77.08%).All of cases were negative in NIMN group.The sensitivity and the specificity of serum PLA2R were 77.08%and 100%.(2) Compared with control groups, the levels of UREA, CYSC and UA were found statistically significant differences in patients with IMN ( P <0.05 ) .( The levels of UREA in control groups and IMN groups respectively:4.12 ±1.25,6.02 ±2.28, t =4.446,P=0.00;UA:262 ±49,331 ±112,t =2.577,P =0.017;CYSC:0.78 ±0.21,1.16 ±0.27,t=4.63,P=0.00.) Compared with control groups, the levels of main items in patients with NIMN had statistically significant differences (P<0.05).(The levels of UREA in control groups and Allergic purpura nephropathy subgroups respectively:4.12 ±1.25,5.43 ±1.84,t=3.606,P=0.000 2;UA:262 ±49, 299 ±51, t=1.050,P=0.03;CYSC:0.78 ±0.21, 1.06 ±0.31, t=1.672,P=0.02.The levels of UREA in control groups and lupus nephropathy subgroups respectively:4.12 ±1.25, 5.90 ±2.20,t=4.225,P=0.00;UA:262 ±49, 342 ±92,t=2.409,P=0.026;CYSC:0.78 ± 0.21,0.92 ±0.24, t =1.674, P =0.00.The levels of UREA in control groups and IgA nephropathy subgroups respectively:4.12 ±1.25,6.69 ±2.87,t=4.756,P=0.00;UA:262 ±49,361 ±52,t=4.598, P=0.00;CYSC:0.78 ±0.21, 1.30 ±0.36,t=4.752,P=0.00.The levels of UREA in control groups and tumor associated nephropathy subgroups respectively: 4.12 ±1.25, 5.02 ±1.70, t =3.626, P =0.002;UA:262 ±49, 289 ±92,t=0.05,P=0.01;CYSC:0.78 ±0.21, 0.98 ±0.20,t=1.1,P=0.01.) There was no statistically significant differences between IMN group and NIMN ( P >0.05 ) . ( 3 ) Positive correlation were found between 24 h PRO(r=0.877,P=0.00),serum UA (r=0.766,P=0.00 ) with the level of PLA2R antibodies fluorescence intensity.( 4 ) There were no correlation between serum PLA2R antibody with IMN pathology aging (r=0.087,0.194,0.182;P=0.598,0.399,0.667).PLA2R positive rate(Ⅰstage:37.50%,Ⅱstage:84.85%, Ⅲstage 85.71%) may increases with the increasing of illness severity.Conclusion Serum PLA2R antibody would be a new laboratory diagnosis standard in patients with IMN.(Chin J Lab Med, 2015, 38:595-599 ) Objective To investigate the diagnostic value and monitoring application of anti-phospholipase A2 receptor antibodies ( PLA2R ) in patients with idiopathic membranous nephropathy ( IMN) .Methods A retrospective study was used .48 patients were diagnosed as idiopathic membranous nephropathy by puncturing kidney from January of 2013 to June of 2014 in the Hospital of Liaoning Traditional Chinese Medical University and Shengjing Hospital of China Medical University were included. 43 patients were diagnosed as non-idiopathic membranous nephropathy ( NIMN ).35 healthy volunteers were selected as control groups.Serum PLA2R were detected by indirect immunofluorescence.The intensity of antibodies fluorescence and the level of urine protein in 24 hours(24 h PRO) ,serum UREA ,serum CYSC, serum UA,GFR were compared in each groups.Measurement data was shown as mean ±standard deviation;Count data was shown as frequency or composition, t test andχ2 test were used as statistical method.Results (1) Among 48 cases with IMN,37 cases showed positive PLA2R (positive rate 77.08%).All of cases were negative in NIMN group.The sensitivity and the specificity of serum PLA2R were 77.08%and 100%.(2) Compared with control groups, the levels of UREA, CYSC and UA were found statistically significant differences in patients with IMN ( P <0.05 ) .( The levels of UREA in control groups and IMN groups respectively:4.12 ±1.25,6.02 ±2.28, t =4.446,P=0.00;UA:262 ±49,331 ±112,t =2.577,P =0.017;CYSC:0.78 ±0.21,1.16 ±0.27,t=4.63,P=0.00.) Compared with control groups, the levels of main items in patients with NIMN had statistically significant differences (P<0.05).(The levels of UREA in control groups and Allergic purpura nephropathy subgroups respectively:4.12 ±1.25,5.43 ±1.84,t=3.606,P=0.000 2;UA:262 ±49, 299 ±51, t=1.050,P=0.03;CYSC:0.78 ±0.21, 1.06 ±0.31, t=1.672,P=0.02.The levels of UREA in control groups and lupus nephropathy subgroups respectively:4.12 ±1.25, 5.90 ±2.20,t=4.225,P=0.00;UA:262 ±49, 342 ±92,t=2.409,P=0.026;CYSC:0.78 ± 0.21,0.92 ±0.24, t =1.674, P =0.00.The levels of UREA in control groups and IgA nephropathy subgroups respectively:4.12 ±1.25,6.69 ±2.87,t=4.756,P=0.00;UA:262 ±49,361 ±52,t=4.598, P=0.00;CYSC:0.78 ±0.21, 1.30 ±0.36,t=4.752,P=0.00.The levels of UREA in control groups and tumor associated nephropathy subgroups respectively: 4.12 ±1.25, 5.02 ±1.70, t =3.626, P =0.002;UA:262 ±49, 289 ±92,t=0.05,P=0.01;CYSC:0.78 ±0.21, 0.98 ±0.20,t=1.1,P=0.01.) There was no statistically significant differences between IMN group and NIMN ( P >0.05 ) . ( 3 ) Positive correlation were found between 24 h PRO(r=0.877,P=0.00),serum UA (r=0.766,P=0.00 ) with the level of PLA2R antibodies fluorescence intensity.( 4 ) There were no correlation between serum PLA2R antibody with IMN pathology aging (r=0.087,0.194,0.182;P=0.598,0.399,0.667).PLA2R positive rate(Ⅰstage:37.50%,Ⅱstage:84.85%, Ⅲstage 85.71%) may increases with the increasing of illness severity.Conclusion Serum PLA2R antibody would be a new laboratory diagnosis standard in patients with IMN.

Objective To evaluate the clinical performance of INNOVANCE D-Dimer,and provide information for clinical application.Methods 402 cases of sodium citrate anticoagulant blood were tested with INNOVANCE assay and PLUS assay on CA7000 analyzer to measure plasma D-Dimer levels.VIDAS-30 immunology analyzer was also used to validate the two assays.4 patients with elevated D-Dimer were monitored continuously during 5 days using INNOVANCE assay and PLUS assay respectively,then the consistency of trend between 2 assays was analyzed.Plasma specimens added with hemoglobin,bilimbin and triglyceride were used to verify the anti-interference capability of INNOVANCE D-Dimer assay.Results In 402 specimens,the result ranges of INNOVANCE D-Dimer and PLUS D-Dimer were [2.15 (0.33,8.63)]mg/L FEU and [325.50 (123.75,974.00)] μ,g/L DDU,respectively.The consistency between two assays was poor (Z =-17.375,P =0.000),especially the results in the range of PLUS D-Dimer (201-300) μg/L DDU and (301-400) μg/L DDU,the coincidence rates were only 25％ and 15％,respectively; the coincidence rate was up to 85％ during PLUS D-Dimer (500-600) μg/L DDU; the coincidence rate was close to 100％ when PLUS D-Dimer over 700 μg/L DDU.Totally 47 of 402 cases were unmatched between two assays.Verified by VIDAS 30,83.0％ (39/47) was false negative for PLUS assay,4.3％ (2/47) was false negative for INNOVANCE assay,12.7％ (6/47) was false positive for PLUS assay.There were 5 false positives and 39 false negative for PLUS assay,totally 45 cases; Two false negative for INNOVANCE assay.Four patients with elevated D-Dimer were monitored and the results showed similar trend between 2 assays.For INNOVANCE assay,the capacity of anti-interference to free bilirubin,unconjugated bilirubin,hemoglobin,and triglyceride was up to 217 μmol/L,337 μmol/L,41.04 g/L,18.35 mmol/L,respectively.Conclusions INNOVANCE assay can markedly reduce false negative results of D-Dimer compared with PLUS assay.INNOVANCE D-Dimer has good performance on anti-interference to jaundice,hemolysis and lipemia samples.

Objective To investigate the effect of 12-lipoxygenase(12-LO) on the p27Kip1 expression in diabetic glomeruli. Methods Mesangial cells were exposed to 12-LO product 12 (S)-HETE (10-7 mmol/L) with or without p38 MAPK (p38) inhibitor (SB203580, 1 μmol/L) for 24 hours. Rats fed with high fat diet received low dose streptozotoein (ST-Z, 35 mg/kg, IP injection) to develop type 2 diabetes and were divided into 2 groups: low dose STZ, low dose STZ+12-LO inhibitor cinnamyl-3,4-dihydroxy-α-cynanocinnamate (CDC, 8 mg/kg) treatment. Rats fed with regular chow were divided into two groups: controls, CDC treatment. The rats received injection of CDC or vehicle subcutaneously in the hind leg. CDC or vehicle injection was performed three times weekly on alternate days. All the rats were sacrificed after 4 weeks, Wild type and 12-LO knockout C57BL/6 mice were divided into 4 groups: wild type control, 12-LO knockout, STZ-induced wild type type 1 diabetes and STZ-induced 12-LO knockout type 1 diabetes. All the mice were sacrificed after 16 weeks. Urine, blood, kidney cortical tissue and isolated glomeruli by sieving method were collected at the end of study respectively. Western blot and immunohistochemistry for target protein were performed respectively. Results Inhibition of p38 activation could significantly reduce p27Kip1 expression induced by 12 (S)-HETE in mesangial cells (P<0.01). Increased glomerular volume, microalbuminuria, elevated glomeluli p38 activation, p27Kip1 expresssion in type 2 diabetic glomeruli was decreased after CDC treatment (P<0.01). Compared with wild type diabetic mice, glomerular p38 activation, p27Kip1 exprcsssion and extracellular matrix accumulation in the 12-LO knockout diabetic mice were significantly decreased (P <0.01, respectively). Conclusions 12-LO induces p27kipl expression via p38 pathway in diabetic glomeruli.

OBJECTIVETo study the effect of astragalosides (AST) on the anoxia/reoxygenation (A/R) injured neuron in rat.

METHODSPrimary cultured rat's hippocampal neurons were made into A/R model cells. The cell viability was detected by MTT assay and lactate dehydrogenase releasing methods; the activity of superoxide dismutase (SOD), and contents of malondialdehyde (MDA) and nitride oxide (NO) in culture supernate were detected; the apoptosis rate of hippocampal neurons after A/R was measured by flow cytometry with double-staining of Hoechst33258 and AnnexinV-PI; and intracellular calcium ion [Ca2+]i was observed with a cofocal laser-scanning microscope and determined by fluorescent probe Fluo-3/AM.

RESULTSAST enhanced the cell viability of neurons after A/R injury, increased SOD activity and decreased the MDA and NO contents in supernate, reduced the A/R-induced apoptosis and decreased the calcium overload in neurons.

CONCLUSIONAST has the protective effects on A/R injured neurons, the mechanism is possibly related with its anti-oxidation and calcium overload reducing actions.

Animals ; Calcium ; metabolism ; Cell Hypoxia ; drug effects ; Female ; Fetus ; Hippocampus ; cytology ; Malondialdehyde ; metabolism ; Neurons ; cytology ; Neuroprotective Agents ; pharmacology ; Nitric Oxide ; metabolism ; Pregnancy ; Primary Cell Culture ; methods ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; prevention & control ; Saponins ; pharmacology ; Superoxide Dismutase ; metabolism ; Triterpenes ; pharmacology

Objective To investigate the correlation between RDW and disease activity in patients with IBD and evaluate clinical significance of RDW as a potential indicator to monitor IBD activity. Methods 256 patients with IBD were divided into two groups. One was UC group including 136 patients with 80 active period cases and 56 emission period cases. Another was CD group including 120 patients with 75 active period cases and 45 emission period cases. 60 bacillary dysentery diseases and 80 healthy controls were selected as bacillary dysentery group and healthy control group. RDW, Hb, WBC, PLT, CRP, ESR, MCV were tested and monitored with development of disease at different stages. We compared RDW with CRP,ESR, PLT, Hb, MCV parameters. By ROC curve analysis, the sensitivity and specificity of RDW was estimated in identifying the IBD's activity. Results The mean values of RDW in active UC group, remission UC group, bacillary dysentery group and control group were ( 16. 1 ± 2. 7), ( 13.5 ± 2. 1 ), ( 13.0 ± 2. 0)and ( 12. 8 ± 1.8), respectively. There was significant difference among four groups ( F = 51.9, P < 0. 01 ).RDW in active UC group was significant higher than that in remission UC group, bacillary dysentery group and healthy control group ( t = 8. 12, 9. 67, 11.85, P < 0.05) and RDW in remission UC group was significant higher than that in bacillary dysentery group and healthy control group as well ( t = 2. 45, 2. 67,P <0. 05). The mean values of RDW in active CD group, remissive CD group,bacillary dysentery group and control group were ( 16. 9 ± 2. 2 ), ( 13. 8 ± 1.1 ), ( 13.0 ± 2. 0), ( 12. 8 ± 1.8 ). There was significant difference among four groups ( F = 113.9, P < 0. 01 ). RDW in the active CD group was significant higher than that in remission CD group, bacillary dysentery group and healthy control group (t = 11.47,18.63,18. 72, P < 0. 05 ) and RDW in remission CD group was also significant higher than that in bacillary dysentery group and healthy control group ( t = 3.60, 3. 72, P < 0. 05 ). RDW in UC and CD groups demonstrated a positive correlation with CRP and ESR (r=0. 484, 0. 525, 0. 286, 0. 358 and P<0. 01, <0. 01, < 0. 05, < 0. 01, respectively) but an inverse correlation with Hb and MCV (r = -0. 378, -0. 271,- 0. 329, - 0. 298 and P < 0. 01, < 0. 01, < 0. 05, < 0. 01, respectively). In UC groups RDW represented a larger area under ROC curve (0. 8.54) compared with CRP, ESR, PLT, Fib and MCV. When the cut-off value of RDW was 14. 0, the sensitivity and specificity for identifying active UC were 82% (65/80) and 72% (40/56) respectively. In CD groups, the area of RDW under ROC curve was the largest (0. 925 )among all indicators. When the cut-off of RDW was 14.5, the sensitivity and specificity for identifying active CD was 88% (66/75) and 82% (37/45) respectively. Conclusion RDW in patients with IBD is a useful indicator to estimate the IBD activity and predict disease progression.