1.Neuroprotective effect of taurine against acute cortical neuron injury induced by oxygen-glucose deprivation
Can LUO ; Lianjun GUO ; Zhikai DAI ; Qin WU ; Jingshan SHI
Chinese Journal of Pharmacology and Toxicology 2006;20(1):1-6
AIM Taurine was reported neuroprotective under several ischemic models in vivo. In this study, the direct effect of taurine against oxygen-glucose deprivation (OGD) inducing acute neuronal injury and the underlying mechanisms in vitro were investigated. METHODSFour hours OGD was used to induce in vitro ischemic injury in rat cortical neurons. Taurine 5, 10 and 20 mmol·L-1 was added 20 h before and during 4 h OGD period respectively. Mortality rate of neuron was assayed by MTT and flow cytometry methods. Level of neuronal [Ca2+]i was detected by Fura 2/AM loading. Amino acid concentrations in culture media were measured by high performance liquid chromatography. RESULTS Under OGD conditions, neuronal death was markedly increased, and the levels of neuronal [Ca2+]i and extracellular glutamate level were enhanced obviously. Taurine pretreatment obviously decreased the percentage of neuronal death induced by OGD. In addition, abnormal elevation of neuronal [Ca2+]i and extracellular glutamate level induced by OGD both were markedly repressed by taurine. CONCLUSION Taurine can alleviate rat cortical neuron injury induced by OGD, the mechanisms were likely due to repressing calcium overload and inhibiting excessive release or leakage of glutamate under such conditions.
2.Differential diagnostic value of CT scan minimum attenuation values in adrenal adenomas and non-adenomas
Ying WU ; Miaoping ZHU ; Zhiiiang HAN ; Peiying WEI ; Zhikai LEI
Chinese Journal of Endocrine Surgery 2017;11(3):192-197
Objective To investigate the differential diagnostic value of CT scan minimum attenuation values (minAVsCT) in adrenal adenomas and non-adenomas.Methods CT scan data of 89 cases of clinical and pathologically confirmed adrenal adenomas were subjected to retrospective analysis and compared with data of 46 cases involving 50 non-adenomas (25 metastases,20 pheochromocytomas,3 lymphomas,and 2 cortical carcinomas).The distributions of mean attenuation values (meanAVs) ¥ 10 Hu and minAVs ¥0 Hu and CT histogram analysis with ≥ 10% negative pixels were observed in adrenal adenomas and non-adenomas,and the diagnostic sensitivity and specificity of these 3 methods for adenomas were calculated.Results The distributions of unenhanced meanAVs ¥ 10 Hu,minAVs ¥0 Hu,and CT histogram analysis with ≥ 10% negative pixels among cases of adenoma and non-adenoma were 62.9% (56/89) and 0% (0/50) (x2=52.687,P=0.000),84.3% (75/89) and 2% (1/50) (x2=83.917,P=0.000),and 77.5% (69/89) and 0% (0/50) (x2=83.917,P=0.000),respectively.The respective diagnostic sensitivities,specificities,false negative rate (FNR),false positive rate (FPR),positive pre dictive value (PPV),negative predictive value (NPV) and accuracy of these 3 methods for adenomas were 62.9%vs 84.3% vs 77.5%,100% vs 98.0% vs 100%,37.1% vs 15.7% vs 22.5%,0 vs 2% vs 0,100% vs 98.7% vs 100%,60.2% vs 77.8% vs 71.4%,and 76.3% vs 89.2% vs 85.6%.Conclusion Although the specificity and PPV of minAVs≤0Hu is slightly less than meanAVs≤10Hu and CT histogram analysis with ≥ 10% negative pixels,it exhibits the best sensitivity and accuracy with a simple operation,and is thus suitable for clinical application.
3.Survey of radiation levels in an abnormally high radon hot spring
Bing SHANG ; Hongxing CUI ; Xiangmin WEN ; Zhikai LIN ; Xiaohua FU ; Yunyun WU ; Jianxiang LIU
Chinese Journal of Radiological Medicine and Protection 2011;31(6):698-702
Objective To investigate the radiation level around Jiangzha hot spring,and to analyze the sources of pollution.Methods The radon and its progeny concentration,γ dose rate in hot spring living district and surrounding area were measured with ATD monitors,radon and WL continuous measurement devices,γ dose rate meter.Results The radon concentration in water was 23 -764 Bq/L.Radon concentration indoors,outdoor and in bathing place were 254 -876 799,688 -709 and 3590-15 299 Bq/m3,respectively.γ dose rate were 205 -28718 nGy/h indoor,4104- 18254 n Gy/h outdoors.Conclusions Jiangzha hot spring is an area with rare high radon and high nature radiation.Its radiation level and health effects are worthy for further attention.
4.The effect of solid phase transformation on the metal-ceramic compatibility of Co-Cr alloy.
Zhikai WU ; Sheng XU ; Ning LI
West China Journal of Stomatology 2011;29(6):568-575
OBJECTIVETo study the effect of solid phase transformation on the metal-ceramic compatibility of Co-Cr alloy during firing programs.
METHODS9 foils of Co-Cr and Ni-Cr alloy with the dimension of 25 mmx3 mmx0.5 mm were casted using lost wax technology respectively. Among them, 6 specimens were subjected to metal-ceramic bonding strength test (three point bending method), the ceramic layer of 3 specimens were removed for X-ray diffraction (XRD) analysis. One cylindrical specimen of each alloy was casted for the test of coefficient of thermal expansion, cooling curves were recorded.
RESULTSThe metal-ceramic bonding strength of Ni-Cr, Co-Cr alloy was (49.1 +/- 3.40), (40.9 +/- 2.02) MPa respectively. There was significant difference between the two groups' bonding strength (P = 0.00). The coefficient of thermal expansion in the 20-500 degrees C interval of Ni-Cr and Co-Cr alloy was 13.9 x 10(-6), 13.8 x 10(-6) x K(-1) respectively. XRD analysis indicated that the microstructure of Ni-Cr alloy was austenite. While Co-Cr alloy was constituted by fcc phase, hcp phase and sigma phase.
CONCLUSIONDuring the cooling procedure, the transformation of fcc phase to hcp phase and segregation of needle-like sigma phase intensify the linear contraction speed of Co-Cr alloy, which decreases the metal-ceramic adaptability.
Alloys ; Ceramics ; Chromium Alloys ; Dental Alloys ; Dental Bonding ; Dental Porcelain ; Materials Testing ; Metal Ceramic Alloys ; Metals
5.Calcineurin signal transduction pathway involves in cardiomyocyte hypertrophy induced by prostaglandin F_(2?)
Qingsong JIANG ; Xienan HUANG ; Qixin ZHOU ; Guizhong YANG ; Zhikai DAI ; Qin WU ; Jingshan SHI
Chinese Journal of Pathophysiology 2000;0(07):-
AIM:To study the role of prostaglandin F2?(PGF2?) in cardiac hypertrophy and its relation with calcineurin(CaN) signal transduction pathway in vitro.METHODS:The cultured neonatal rat cardiomyocyte was used to observe the hypertrophic effect of PGF2?,and the hypertrophic response was assayed by measuring the cell diameter,protein content and atrial natriuretic factor(ANF) mRNA expression.For mechanism studies,the intracellular free calcium concentration([Ca2+]i) in cultured cardiomyocytes was measured by using Fura-2/AM as a fluorescent indicator.ANF and CaN mRNA expressions,and the expressions of CaN and its downstream effectors,NFAT3 and GATA4 proteins were assayed by RT-PCR and Western blotting,respectively.RESULTS:In cultured cardiomyocytes,PGF2? induced profound hypertrophic morphology change and the significant increase in cell diameter,and protein content in a concentration-dependent manner compared with those in vehicle control(P
6.Predictive value of multiple ultrasonic features combination in diagnosis of thyroid papillary carcinoma larger than 1.0 centimeter
Ying, GU ; Zhikai, LEI ; Zhijiang, HAN ; Lingyun, BAO ; Jian, WU ; Jinwang, DING
Chinese Journal of Medical Ultrasound (Electronic Edition) 2016;13(12):925-930
Objective To discuss the predictive value of multiple ultrasonic features combination in diagnosis of thyroid papillary carcinoma (PTC) more than 1.0 cm in diameter. Methods The ultrasonic features of 258 PTC nodules from 251 patients and 207 nodular goiter (NG) nodules from 190 patients in the First People′s Hospital of Hangzhou were retrospectively analyzed. All the nodules were confirmed by pathological examination after surgery. The ultrasonic features included the shape of nodules, internal echo,anteroposterior/transverse diameter ratio (A/T), and microcalcification. The χ2 test was used to analyze the differences of ultrasonic features between PTC and NG. Multi-variate analyses (Logistic regression) was used to analyze the predictive risk ultrasonic features of PTC. The sensitivity and specificity of ultrasonic features were analyzed based on the gold standard of pathological results. Results There were significantly differences between 258 PTC nodules and 207 NG nodules in irregular shape, hypoechogenicity,A/T > 1 and microcalcification (χ2 values were 121.511, 105.411, 41.483, 121.072, all P < 0.01). The results of Logistic regression showed that irregular shape, hypoechogenicity, A/T>1 and microcalcification were risk ultrasonic features of PTC. And their OR values were 5.013 (95%CI 2.919-8.610), 5.811 (95%CI 3.411-9.901), 15.399 (95%CI 7.576-31.301), 4.141 (95%CI 1.687-10.164) respectively. The sensitivity and specificity of single ultrasonic feature were 26.0%-79.5% and 71.5%-96.1%; the sensitivity and specificity of two ultrasonographic features combination were 11.2%-57.0% and 92.3%-99.0%; and the sensitivity and specificity of three or four ultrasonographic features combination were 8.1%-31.8% and 99.0%-99.5%.Conclusions Irregular shape, hypoechogenicity, A/T> 1 and microcalcification of thyroid neoplasm are important ultrasonic features of PTC. Although the sensitivity of single ultrasonic feature in diagnosing PTC is higher than that of multiple features combination, it has a lower specificity. Therefore, combination of multiple ultrasonographic features can improve the specificity in diagnosing PTC and reduce the misdiagnosis of PTC.
7.Study on corrosion resistance of three non-noble porcelain alloys.
Zhikai WU ; Sheng XU ; Wei LI ; Jin TENG ; Ning LI
West China Journal of Stomatology 2011;29(5):485-493
OBJECTIVETo study the electrochemical corrosion behavior of Co-Cr, Ni-Cr and Ni-Cr-Be based porcelain alloys in NaCl solution.
METHODSFive samples of each alloy were made respectively, electric polarization curve of each alloy was obtained using potentiodynamic polarization technique. Self-corrosion potential (E(corr)), self-corrosion current density (I(corr), passive region and transpassivation potential were tested. Microstructure and constituent was examined using scanning electron microscopy and energy dispersive spectroscopy.
RESULTSCo-Cr alloy possessed the most desirable corrosion resistance because of its integrated, homogeneous and compact passive film. The poor compactness of Ni-Cr alloy's passive film decreased its corrosion resistance. Ni-Cr-Be alloy exhibited the worst corrosion resistance due to the Cr and Mo depleted Ni-Be eutectic phases in the alloy.
CONCLUSIONTaking biological security into consideration, it is necessary to avoid the application of porcelain alloys with Be element. Co-Cr alloy with better biocompatibility possesses much broader prospect in the field of dental restoration.
Alloys ; Chromium Alloys ; Corrosion ; Dental Alloys ; Dental Porcelain ; Microscopy, Electron, Scanning ; Nickel ; Surface Properties
8.Apoptosis inducing effect of tanshinone II(A) on human nasopharyngeal carcinoma CNE cells.
Zhikai DAI ; Dalin HUANG ; Jingshan SHI ; Limei YU ; Qin WU ; Qing XU
China Journal of Chinese Materia Medica 2011;36(15):2129-2133
OBJECTIVETo investigate anticancer effect and potential mechanism of tanshinone II(A) (Tan II(A)) on human nasopharyngeal carcinoma cell line CNE cells.
METHODAntiproliferative effect of Tan II(A) on CNE cells was evaluated by morphological examination, cell growth curves, colonial assay and MTT assay. Apoptosis detection was carried out using Hoechest 33258 and PI double-dyeing method. Intracellular Ca2+ concentration and mitochondria membrane potential were detected by fluorospectrophotometer. Bad and MT-1A transcript analysis in CNE cells was analyzed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR).
RESULTTan II(A) could inhibit CNE cells proliferation in dose- and time-dependent manner. 50% inhibiting concentration of Tan II(A) on CNE cells in 24, 48, 72 h was 45.7, 24.8, 3.3 mg x L(-2), respectively. Typical apoptotic morphology such as chromatin aggregation was observed in CNE cells with Tan II(A) treated for 24 h, and the apoptotic inducing effect was in a dose-dependent manner. After treated with Tan II(A), intracellular Ca2+ concentration of CNE cells was increased, mitochondria membrane potential of the cells was decreased, relative mRNA level of Bad and MT-1A was up-regulated.
CONCLUSIONTan II(A) had anticancer effect on CNE cells through apoptosis via calcineurin-dependent pathway and MT-1A downregulation.
Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Calcium ; metabolism ; Carcinoma ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Diterpenes, Abietane ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Membrane Potential, Mitochondrial ; drug effects ; Metallothionein ; genetics ; Nasopharyngeal Neoplasms ; genetics ; metabolism ; pathology ; Signal Transduction ; drug effects ; bcl-Associated Death Protein ; genetics
9.Influence on microstructure of dental zirconia ceramics prepared by two-step sintering.
Chao JIAN ; Ning LI ; Zhikai WU ; Jing TENG ; Jiazhen YAN
West China Journal of Stomatology 2013;31(5):496-499
OBJECTIVETo investigate the microstructure of dental zirconia ceramics prepared by two-step sintering.
METHODSNanostructured zirconia powder was dry compacted, cold isostatic pressed, and pre-sintered. The pre-sintered discs were cut processed into samples. Conventional sintering, single-step sintering, and two-step sintering were carried out, and density and grain size of the samples were measured. Afterward, T1 and/or T2 of two-step sintering ranges were measured. Effects on microstructure of different routes, which consisted of two-step sintering and conventional sintering were discussed. The influence of T1 and/or T2 on density and grain size were analyzed as well.
RESULTSThe range of T1 was between 1450 degrees C and 1550 degrees C, and the range of T2 was between 1250 degrees C and 1350 degrees C. Compared with conventional sintering, finer microstructure of higher density and smaller grain could be obtained by two-step sintering. Grain growth was dependent on T1, whereas density was not much related with T1. However, density was dependent on T2, and grain size was minimally influenced.
CONCLUSIONTwo-step sintering could ensure a sintering body with high density and small grain, which is good for optimizing the microstructure of dental zirconia ceramics.
Ceramics ; Zirconium
10.Analysis of the efficacy of arthroscopic transverse release of iliotibial band through peritrochanteric space for the treatment of external snapping hip
Yidong WU ; Kangkang YU ; Zhongyao LI ; Lu GAN ; Qi JIA ; Zhongyuan ZHAO ; Yang HE ; Zhikai GUO ; Chunbao LI
Chinese Journal of Orthopaedics 2024;44(1):18-24
Objective:To analyze the clinical efficacy of arthroscopic transverse release of the iliotibial band through peritrochanteric space for the treatment of external snapping hip.Methods:A total of 30 patients (12 males and 18 females) with bilateral external snapping hip underwent arthroscopic transverse release of the iliotibial band through peritrochanteric space in Department of Sports Medicine, Senior Department of Orthopaedics, the Fourth Medical Center, Chinese PLA General Hospital were retrospectively analyzed from May 2021 and June 2022. The average age was 32.5±8.2 years (range, 17-51 years). At the same time, 30 patients who underwent arthroscopic external release of the iliotibial band through the external surface of the iliotibial band (external iliotibial band group) were selected as control group, including 13 males and 17 females, aged 29.5±6.8 years (range, 11-45 years). The visual analogue scale (VAS), modified Harris hip score (mHHS), and gluteal muscle contracture disability scale (GDS) were compared between the two groups at preoperative, 6 months postoperative, and final follow-up.Results:All patients successfully completed the operation and were followed up for 17.5±3.3 months (range, 12-25 months). The VAS scores of the two groups at the last follow-up were lower than those before operation ( P<0.05). The mHHS scores before operation, 6 months after operation and at the last follow-up in the peritrochanteric space group were 76.5 (67.0, 85.5), 98.5 (94.8, 100.0) and 100.0 (97.0, 100.0), respectively, and those in the external iliotibial band group were 80.5 (70.0, 86.0), 100.0 (96.0, 100.0) and 100.0 (99.5, 100.0). The differences in mHHS scores between the two groups were statistically significant for intragroup comparisons ( P<0.05); of these, 6 months postoperatively and at the last follow-up were greater than preoperatively, with statistically significant differences ( P<0.05); the differences at 6 months postoperatively and at the last follow-up were not statistically significant ( P>0.05). There was no significant difference in mHHS scores between groups at different time points ( P>0.05). The GDS before operation, at 6 months after operation and at the last follow-up were 47.0 (35.8, 64.5), 90.0 (81.0, 94.0) and 93.5 (89.8, 98.0) in the peritrochanteric space group, and 51.0 (38.0, 64.5), 50.0 (81.0, 94.0) and 93.5 (89.8, 98.0) in the external iliotibial band group, respectively. The differences in GDS between the two groups were statistically significant for intragroup comparisons ( P< 0.05); of these, 6 months postoperatively and at the last follow-up were greater than preoperatively, with statistically significant differences ( P<0.05); the differences at 6 months postoperatively and at the last follow-up were not statistically significant ( P>0.05). There was no significant difference in GDS between groups at different time points ( P>0.05). Conclusion:Arthroscopic transverse release of the iliotibial band through peritrochanteric space for the treatment of external snapping hip can effectively reduce hip pain and improve hip function, with satisfactory clinical results, and can be used as an alternative treatment to transverse release through the external surface of the iliotibial band.