1.Laboratory developed tests in the development of modern medicine: opportunities and challenges
Yu WU ; Gusheng TANG ; Qian SHEN
Chinese Journal of Laboratory Medicine 2015;38(1):10-12
Translational medicine and personalized medicine are becoming the new power in modem medical development.Laboratory Developed Tests (LDTs) based on molecular biology and bioinformatics technology play a vital role in the development process of translational medicine and personalized medicine.Nowadays,LDTs consist of a broad range of in vitro diagnositc tests performed to analyze nucleic acid,chromosomes,proteins,certain metabolites and cell surface molecules using immunological technique,cytogenetic or molecular methods or a combination of these methods.These LDTs are used to detect heritable or acquired disease-related genotypes,mutations,or phenotypes,and also used to classify the pathological changes of cells for clinical purposes.New generation LDTs,present some unique regulatory questions still remain to be discussed.Clinicians should capture the opportunity to establish and continuously improve the detection platforms of LDTs,the quality control system and management standards.On this basis,transformation bridges between scientific research and clinical application will be truly built.
2.Analysis,identification and strategies on interferences in immunoassay
Gusheng TANG ; Yu WU ; Qian SHEN
Chinese Journal of Laboratory Medicine 2009;32(7):725-729
Substances that might potentially alter the measurable concentration of the analyte or alter the binding ability of detection antibody can lead to immunoassay interference. Endogenous interferences consist of autoantibodies, heterophiles antibodies, human anti-animal antibodies (HAAA) and some binding proteins. Lipidemia, cross-reactivity, pre-analytical variation, matrix and different detection equipments may also affect immunoassay. These interfering substances may cause falsely increased or decreased concentration in many analytes, including hormones, tumor markers, drugs, cardiac tropanin and microbial serology, thus it will affect the diagnosis of patients and the evaluation of therapeutic strategies Laboratorians and physicians should both be aware of the potential interference in immunoassays and communicate closely when any clinical discordance between the clinical and the laboratory data appears, avoiding a subsequent wrong diagnosis and unwarranted treatment. In this case, an alternative assay or measurement is needed for the potential correct results.
3.Characteristics of autoantibody and its perspectives for clinical diagnostics
Gusheng TANG ; Dongbao ZHAO ; Yu WU ; Qian SHEN
Chinese Journal of Laboratory Medicine 2012;35(3):193-196
Disease-associated autoantibodies (AAB) are important for the diagnosis of respective autoimmune diseases (AID).Autoantibodies can also be used for monitoring of response to therapy and for prognostic purpose.However,significant biological heterogeneity of autoantibody response,the difficulty in simultaneously improving detection sensitivity and specificity of autoantibodies and the lack of standardization in detection methods lead to limitations in its clinical applications and some difficulties in explaining the test results.It is important to search for novel autoantibodies in sera,to establish and standardize automated detection platforms with good quality and to perform well-designed clinical evaluation in the future research and clinical applications of autoantibodies.
4.Pathogens of Nosocomial Infection in Intensive Care Units and Related Drug-resistance Analysis
Qiongna CHEN ; Yanbo LI ; Zhehua CHEN ; Haihong TANG ; Qian YU
Chinese Journal of Nosocomiology 1994;0(04):-
OBJECTIVE To estimate the distribution of pathogens of nosocomial infection in intensive care units,the sites where infections often taken place and the related antibiotic-resistance of bacteria.METHODS Various samples of bacteria from intensive care units have been examined by applying half-automatic analyzer ATB Expression,with bacteria inspecting cards and drug-sensitivity cards,all from Bio-Merieux,France.RESULTS Totally 153 strains of nosocomial pathogens have been found,where Acinebacter baumannii,fungi and Pseudomonas aeruginosa ranked top three,with rates of 32.0%,16.3%,and 15.0%,respectively.About 45.8% of pathogens were found in samples from the lower respiratory tract.Approximately 4.3% of A.baumannii showed drug-resistance to imipenem.However,more than 50.0% of A.baumannii presented its strong drug-resistance to rest of eight regular antibiotics.CONCLUSIONS A.baumannii is a dominating pathogen to cause nosocomial infection in intensive care units,and has shown strong multi-drug-resistance,which should incur high clinical attention.It comes to be crucial to highlight sanitization and sterilization operation,applying proper antibiotics in order to reduce appearance of bacteria with drug-resistance.
5.Study on injury of human vascular endothelial cells by cholesterol
Zhishun LU ; Xiao YU ; Junli TANG ; Minzhang QIAN
Journal of Third Military Medical University 2003;0(16):-
Objective To investigate the injuries caused by cholesterol to the vascular endothelial cells (VECs). Methods Different dosage of cholesterol (6.25,12.5,25.0,50.0 mg/L) was used on human umbilical endothelial cell line,ECV304,respectively. LDH activity,nitric oxide and the nitric oxide synthetase activity in the supernatant of cell culture were detected. The concentration of MCP-1 protein in cell culture was detected by ELISA. Results As compared with the normal control cells,a significant increase of LDH activity was found in the cells treated with 50.0 mg/L cholesterol. The NO level decreased in the cells treated by 25.0 or 50.0 mg/L cholesterol. When treated by cholesterol at dose of 6.25,12.5,25.0 or 50.0 mg/L respectively,the NOS activity was greatly decreased and MCP-1 protein was significantly increased in a dose-dependent manner. Conclusion Cholesterol of high concentration could directly injure the structure and partial function of VECs.
7.Negative interference of circulating troponin autoantibodies in five commonly used cardiac troponin Ⅰ detection systems
Yu WU ; Weiguo ZHAO ; Gusheng TANG ; Qian SHEN
Chinese Journal of Laboratory Medicine 2009;32(7):749-753
Objective To explore the possible negative interference of circulating cardiac troponin Ⅰ(cTnI) autoantibody on the immunoassay of cTnI in five commonly used cTnI detection systems. Methods Thirteen patients with positive cTnI autoantibodies in their serum samples were firstly screened and selected from 121acute myocardial infarction (AMI) patients using ELISA assay. The serum cTnI values and their recovery rates were then carefully measured and analyzed. Results cTnI values in these 13 samples showed amazing difference in the five detection systems, demonstrating various degrees of pseudo-drop, or even false-negative. One sample with low recovery was detected in Access-2 system. One sample with low recovery as well as one sample with moderate recovery were detected in Architect i2000 (Abbott). Two samples with moderate recovery and one sample with low recovery were detected in Axsym(Abbott). Three samples with moderate recovery and two samples with low recovery were detected in Dimension X Pand (Dade Behring)and one sample with moderate recovery together with four samples with low recovery were detected in Vidas (Biomerieux). And the serum levels of autoantibodies (A450) positively correlated with the degrees of their negative interference for the detection of cTnI. The R2 and P values on each system were 0. 841 (P <0. 01)vs Access-2, 0. 808 (P < 0. 01) vs Architect i2000 (Abbott), 0. 772 (P < 0. 01) vs Axsym (Abbott), 0. 707 (P < 0. 01) vs Dimension X Pand (Dade Behring) and 0. 424 (P < 0. 05) vs Vidas (Biomerieux), respectively. Conclusion Circulating autoantibodies of cTnI can induce considerable negative interference in all the 5 commonly used cTnI detection systems, which might then lead to incorrect judgments of the obtained results of cTnI in daily clinical work.
8.Determination of Mercury, Arsenic and Selenium in Soils by One-time Digestion
Wei QIAN ; Haoye TANG ; Ruhai WANG ; Hua GONG ; Qian JIANG ; Yuanchun YU
Chinese Journal of Analytical Chemistry 2017;45(8):1215-1221
A method for the determination of three volatile elements (mercury, arsenic and selenium) in soils by one-time digestion was established.The digestion of samples was carried out in an automatic program temperature controlled graphite digestion instrument by aqua regia + hydrofluoric acid+boric acid.Hydride generation atomic fluorescence spectrometry (HG-AFS) was used to determine the contents of mercury, arsenic and selenium in the same digestion solution.The accuracy of the method was verified by the results of the soil environment samples of certified reference materials GSS-1-GSS-8 from the Center of the National Standard.The contents of soil mercury, arsenic and selenium obtained by this method were consistent with the standard values of these elements provided by the Center of the National Standard.In comparison with the current standard methods, the one-time digestion method was simplified, the pre-processing time was saved, and the reagent consumption was reduced.The method had wide range of application, high sensitivity, low detection limit, which was especially suitable for trace analysis of bulk samples, and also it could be used as a rapid digestion method for the measurement and governance of heavy metals in polluted soils.
9.Role of connexin 43 gene in peritoneal metastasis of gastric cancer
Bo TANG ; Peiwu YU ; Zhihong PENG ; Ge YU ; Feng QIAN ; Yan SHI ; Yongliang ZHAO ; Yun RAO
Chinese Journal of Digestive Surgery 2009;8(6):425-427
Objective To investigate the relationship between the expression of eonnexin 43 (Cx43) and clinicopathologieal characteristics of gastric cancer, and to study the role of Cx43 in peritoneal metastasis of gastric cancer. Methods Thirty-two patients who had gastric cancer and with peritoneal metastasis had been admitted to Southwest Hospital from January 2000 to December 2008. Gastric cancer tissues, adjacent tissues and metastatic peritoneal tissues were obtained postoperatively, and the expression of Cx43 was detected by immunohistochemistry. The relationship between Cx43 expression and clinicopathological characteristics of gastric cancer was analyzed. All data were analyzed via Spearman rank correlation coefficient, Fisher exact probability and chi-square test. Results The expression of Cx43 was mainly detected in the cell membrane and cytoplasm. The positive expres-sion rates of Cx43 in gastric cancer tissues, adjacent tissues and metastatic peritoneal tissues were 34% (11/32), 100% (32/32) and 94% (30/32), respectively. There were significant differences in the Cx43 expression between gastric cancer tissues and adjacent tissues (X~2=28.350, P < 0.01), and between gastric cancer tissues and metastatic peritoneal tissues (X~2 = 21.989, P < 0.01). The expression of Cx43 did not correlate with age and sex of patients (r = -0.030, - 0.169, P > 0.05), but with tumor differentiation, histological type and lymph node metastasis (r = 0.750, 0.642, - 0.357, P < 0.05). Conclusions There is a decreased expression of Cx43 in gastric cancer tissues and a up-regulated expression of Cx43 in metastatic peritoneal tissues. Cx43 may play a positive role in the peritoneal metastasis.
10.Changes of Sema3A and Np1 in the entorhinal cortex and dentate gyrus of temporal lobe epilepsy rat
Xue-Qian YUAN ; Bo XIAO ; Tie-Yu TANG ; Ling LI ; Shu-Yu LI ; Guo-Liang LI ;
Chinese Journal of Neurology 2001;0(03):-
Objective To explore the changes of Sema3A and it′s receptor Npl in temporal lobe epilepsy(TLE)rat brain and the roles in epileptogenesis mechanism.Methods TLE model was established with male healthy SD rats,in which mossy fiber sprouting(MFS)was verified using Neo-Timm staining method.Sema3A mRNA,Npl mRNA and protein was respectively analyzed by immunohistochemistry and in situ hybridization in the entorhinal cortex(EC)or dentate gyrus(DG)at different time after LiCL-PILO induced TLE.Results There were Mossy fiber sprouting(7d:0.70?0.42,15d:1.50?0.52,30 d:2.20 ?0.41,60 d:2.50?0.51)in DG inner molecular layer(IML)of TLE rat compared with those of controls (P