Insulinoma-glucagonoma clone 20 can express at least 6 isoforms in human cells.These isoforms can affect cell apoptosis and proliferation through apoptosis related signaling pathway,such as TRAIL or TNF signaling pathways.Furthermore,insulinoma-glucagonoma clone 20,as a GTP-GDP exchange factor,participates in the transportation of nerve synaptophysins.

Objective To investigate the prevalence of virulence genes(ply, pspA, nanA, lytA, psaA) among Streptococcus pneumoniae recently isolated from clinical patients. Methods The 133 strains were isolated from patients in three teaching hospitals in Chongqing from 2006 to 2008. Polymerase chain reaction was used to screen for virulence genes (ply, pspA, nanA, lytA, psaA). Results The positive rate of lytA, psaA, ply, nanA and pspA in 133 clinical isolates were 94.7%, 85.0%, 82.7%, 84. 2% and 60.2%, respectively. The positive rates of the lytA, psaA, ply, nanA and pspA genes in 87 common serotypes isolates was 100%, 87.4%, 86.2%, 89.7%, 67.8%, respectively. Conclusion The total positive rates of five virulence genes in the 133 clinical strains were high. The positive rates of five genes in the com-mon serotypes isolates were higher than those in the no-common serotypes. These genes are important virulence genes of Streptococcus pneumoniae. They could be candidates for protein vaccine of Streptococcus pneumoniae.

Objective To investigate long-term biological variability of serum lipids in Chinese. Methods Serum lipids in a Chinese population with relatively stable life styles were monitored with standardized measurements for 1 year (specimens were taken bimonthly) (23 subjects) or 10～15 years (yearly) (100 subjects). Results The total intra-individual variability (analytical and biological variations combined) of total cholesterol, triglycerides, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol averaged 10%, 28%, 16% and 18%, respectively. Conclusion Biological intra-individual variability is a major source of inaccuracy of cardiovascular risk assessments based on lipid measurements. Measures need to be taken to minimize biological variation when medical decisions are to be made in the treatment of lipid disorders.

Objective To establish a method for measuring serum cotinine by isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) and provide an assay that can be applied to theevaluation of the level of smoke exposure and to the risk analysis of smoking related diseases.Methods Blood samples were collected from 94 apparently healthy subjects from October to December in 2010 and centrifuged,and the sera were separated.Serum samples were mixed with [ D3 ] -cotinine ( as the internal standard) and treated with acetonitriles to precipitate protein.After centrifugation,the supernatants were transferred and evaporated under a stream of nitrogen until dryness and reconstituted with mobile phase.Then the residuals were analyzed by LC/MS/MS system with multiple reaction monitor model; the concentration of cotinine were quantified by the isotope internal standard method and the stand curve was employed with a series of calibration.To estimate the precision of the method,five frozen serum pools were repeatedly analyzed in five runs,and every pool was analyzed in triplicate.In addition,the recovery rates were analyzed with the serum sample added with different levels of standard.The stability of cotinine in serum preserved at room temperature,4 ℃ and - 80 ℃,respectively.Finally,the levels of cotinine of 94 healthy subjects were measured to evaluate the distribution of cotinine with different smoke statuses.Results Serum cotinine measured by ID-LC/MS/MS was separated well with few interferences.The correlation coefficients between the peak area ratios and cotinine concentrations were higher than 0.9993.The values of within-run coefficients of variation (CV) of five frozen serum pools (0.68,48.42,94.34,250.95 and 287.04 μg/L) were 2.19％,0.78％,0.75％,0.65％ and 0.67％,respectively.The values of total CV were 4.71％,1.40％,1.98％,1.10％ and 1.03％,respectively.The limit of detection (LOD) and limit of quantitation ( LOQ ) were 0.013 and 0.050 μg/L,respectively.The analytical recoveries ranged from 99.22％ to 102.67％.The samples could maintain stability within 2 d at room temperature,7 d at 4 ℃ and 3 months at -80 ℃ resulting the accuracy of measurements from 99.28％ to 100.87％ and the CV＜5％.The levels of cotinine of 94 healthy subjects were measured and shown skewed and leptokurtic distribution.The concentrations of twenty smokers,fourteen former smokers and sixty non-smokers were 116.40 (63.17 -241.12),0.67 (0.15 - 0.95 ) and 0.22 (0.15 - 0.42 ) μg/L,respectively.Furthermore,the level of cotinine of former smokers (Z =-2.12,P ＜0.05) and smokers (Z =-6.67,P ＜0.001) were statistically higher than non-smokers.Conclusions An ID-LC/MS/MS method for serum cotinine detection has been established.It is hoped that the method will be applied to the assessment of smoke exposure and its association with the risks of smoking related diseases since it is simple,specific,precise,sensitive and accurate.

Objective To develop an HPLC method for the measurement of n-3 fatty acid index of serum cholesteryl esters.Methods Serum triglycerides were hydrolyzed with ethanolic sodium hydroxide and cholesteryl esters (CEs) were extracted with hexane.The extracted CEs were analyzed by reversed phase HPLC with a UV detection at 205 nm.Cholesteryl eicosapentaenoate and docosahexaenoate ( major n-3 fatty acid cholesteryl esters) were identified by liquid chromatography-tandem mass spectrometry and cholesterol in each CE fraction was measured.Peak areas of CEs were corrected for cholesterol and CE n-3 index was calculated using the corrected peak area and expressed as the percentage of n-3 fatty acid CEs in total CEs.Results The HPLC analysis can be finished in 6 minutes.Triglycerides which interfere with the determination of n-3 fatty acid index, were hydrolyzed with ethanolic sodium hydroxide (4 mol/L) in 30 seconds.The within-run and total CVs for CE n-3 index averaged 0.66% and 0.90%, respectively.CE n-3 indexes of 70 volunteers and 36 coronary heart disease patients apparently healthy subjects and patients with coronary heart disease in Beijing Hospital appeared to be positively skewed and leptokurtic distribution ( skewness = 1.25, kurtosis = 1.70 ).The median of n-3 indices were 0.98% ( 0.37% - 2.40% ).The logarithm of n-3 index appeared to be normal distribution and the average is 0.003 7% with standard deviations of 0.15.The distribution of n-3 indices of gender groups was similar with the total.The medians of females and males were 1.08% (0.60% -2.40%) and 0.95% (0.37% -2.11%) respectively, and the former were significantly higher than the latter( t = - 3.021, P = 0.003 ).Conclusion A new method for the measurement of n-3 index of serum cholesteryl esters by HPLC has been established.It is simple and precise and can be used in predicting cardiovascular diseases risks and monitoring dietary intake of n-3 fatty acids.

Objective To study the expression of thymic stromal lymphopoietin(TSLP) and the activation of DCs in OVA-induced murine asthma model, and investigate the effects and underlying mecha-nisms of TSLP on lung inflammation. Methods Thirty BALB/c mice were randomly divided into control group, OVA group and TSLP neutralizing antibody treated group. The asthma model was evaluated by airway responsiveness and histological analysis of lung tissues ; The levels of TSLP mRNA in lungs were determined by quantitative real-time PCR; The expression of TSLP in lungs were determined by immunohistochemistry and Western blot; The expression of CD40, CD80, CD86 in BALF was detected by FACS. Results Both the histological analysis of lung tissues and the airway responsiveness were all consistent with the characteris-tic of murine asthma model. The expression of TSLP and TSLP mRNA in the OVA group was significantly in-creased compared with blank group. The expression of CD40, CD80, CD86 in BALF from OVA group was increased significantly compared with the control group. Furthermore, treating mice with TSLP neutralizing antibody reduced the expression of CD40, CD80, CD86 on dendritic cells, and IL-4, IL-5, IL-13 in the OVA group. Conclusion Our study indicate that TSLP was highly expressed in the bronchial epithelia of murine asthma model, via upregulation of CD40, CD80, CD86, induce DCs to active CD4~+ T cells and pro-duce type 2 responses, so that aggravating the lung inflammation of asthma. Blocking TSLP is capable of in-hibiting the production of Th2 cytokines, thus presents a promising strategy for the treatment of asthma.

Objective To evaluate the analytical performance of 7 homogeneous HDL-cholesterol reagents. Methods An altracentrifugation-HPLC method was used as the comparison method. Fourty fresh patient samples were analyzed by homogeneous methods and the comparison method. The homogeneous methods were all performed on a Hitachi 7170A chemistry analyzer according to the manufacturer's instructions, Precision, accuracy and total errors were analyzed. Results The homogeneous assays typically demonstrated within run coefficient variance(CV) of < 1%, and total CV of < 3%. Methods A, B and D showed average bias, bias at the medical decision points and total errors all within the NCEP performance criteria and method C and F unacceptable biases (-19.74% and 11.46%, respectively) and total errors according to the NCEP criteria. However, all the homogenous methods (A-F) had total errors of < 30%, as required by the US Clinical Laboratory Improvement Amendment (CLIA). Conclusions Homogeneous HDL-C assays have been shown to be reasonably precise, but discrepant results have been observed with some of the assays. Clinical laboratories should pay more attention on selecting and validating homogeneous HDL-C reagents.

Objective To standardize total cholesterol (TC) and HDL cholesterol (HDLC) analytical systems with the US CDC TC reference method and HDLC designated comparison method (DCM). Methods CDC TC reference method and HDLC DCM were set up and the quality was controlled by participating in the CDC Cholesterol Reference Method laboratory Network (CRMLN) bimonthly survey. The performance of 21 TC or HDLC analytical systems from 3 manufacturers were tested with the methods according to the CRMLN certification protocols. Results The coefficient variation (CV) of TC analyses with the reference method in 18 surveys averaged 0.29% and the bias versus CDC target value 0.1%. The DCM HDLC CV in 17 surveys averaged 0.010 mmol/L(0.39 mg/dl) and the averaged biases versus CDC target and group mean were - 0.019 mmol/L (-0.72 mg/dl) and - 0.006 mmol/L (-0.25 mg/dl), respectively. Most of the TC and HDLC analysis events (> 90%) satisfied the CRMLN accuracy and precision criteria for the reference method and DCM. Eighteen of the 21 tested TC or HDLC systems met the performance criteria for analytical systems and were certified for traceability by CDC. Conclusions A reference method for cholesterol and a DCM for HDLC and performed within an international reference laboratory network have been established and used for certification of TC and HDLC analytical systems, Further application of the methods to the standardization of lipid analysis are expected.

Objective To develop an HPLC method for the measurement of fractional and molar esterification rate of serum HDL(FER HDL and MERHDL).Methods Blood samples were mixed with 5,5'-dithiobis-(2-nitrobenzoic acid)(DTNB)and the sera were separated.Serum HDL fractions were prepared by precipitation with Dextran sulfate and magnesium and the fractions were incubated at 37℃for 1 h in the presence and absence of 2-mercaptoethanol(ME).Free cholesterol levels of the HDL fractions were analyzed by HPLC and FERHDL and MERHDL were calculated.Results Under the selected conditions,serum free cholesterol could be stabilized by inhibition of LCAT with DTNB and the inhibition be reversed by ME. The total CVs for FERHDL and MERHDL were 1.59%-3.74% and 1.64%-2.88%,respectively.The averages of FERHDL and MERHDL in 70 apparently healthy subjects were 18.7%/h and 42.7 μmol·L-1·h-1 with standard deviations of 7.2%/h and 11.8 μmol·L-1·h-1·respectively,and the medians were 16.1%/h and 11.8 μmol·L-1·h-1.Close correlations of FERHDL.and MERHDL with other cardiovascular disease risk factors were observed.Conclusion A new method for the measurements of FERHDL and MERHDL by HPLC has been estabished. The method is safe, precise and simple and applications in the assessment of cardiovascular diseases risks are expected.