Proficiency testing for determination of photometric method of bacterial endotoxin / 中国药理学通报

Aim To design and implement the bacteri¬al endotoxin test proficiency testing plan to evaluate the laboratory's ability and level to determine bacterial en¬dotoxin. Methods According to the Chinese Pharma-copoeia (2015 edition, Vol IV) -1143 Bacterial Endo¬toxin Test-Photometric Method ( Method 2 ) , each la¬boratory used any of these methods to determine the endotoxin content of the sample to be tested. The stati- stical software JMP13 was used for statistical analysis of the feedback results of the participating laboratories. The consensus value of the participants, namely the ro¬bust average value of the effective test results of all the participating laboratories, was used as the assigned value X of the endotoxin content of the samples to be tested in the proficiency testing of the round. The re¬sults of participating laboratories were evaluated ac¬cording to the following criteria: (1) the laboratory test results were within 50% to 200% of the assigned value of the sample, which was evaluated satisfactory; ( 2 ) the laboratory test results were not within the 50 -200% range of the assigned value of the sample, which was evaluated dissatisfactory. Results A total of laboratories participated in this capacity verification plan, with 45 in the laboratory with satisfactory re¬sults, with a satisfaction of 91. 8% ; There were 4 la¬boratories that received "dissatisfaction" results, all of which were not within the range of 50% -200% of the assigned value of samples, and the dissatisfaction of 8. 2% . Conclusions Most of the participating labora¬tories can accurately detect the bacterial endotoxin con¬tent in the sample to be tested, indicating that the level of bacterial endotoxin detection in our country is gener¬ally good at present.

Methodological Research on Latex Enhanced Immune Turbidimetric Method for the Detection of Urine Free Hemoglobin / 现代检验医学杂志

Objective To establish the test way of latex enhanced immune turbidimetric method for the concentration detection of urine free hemoglobin on the automatic biochemical analyzer,and evaluated the detection performance.Methods Prepared the detection reagents of latex enhanced immune turbidimetry method for detection of urine free hemoglobin with materials such as hemoglobin HBA0 antibody (8.5 mg/ml),80 nm carboxylic olystyrene latex microspheres (estapor,nanometer microspheres) and so on.Then,seted the project parameters on TBA120 automatic biochemical analyzer and proceeded the calibrations.Evaluated the detection performance by accuracy,precision,linear range,sensitivity,specificity and other indicators.Lastly,established the biological reference interval for urine free hemoglobin of healthy people in the region and verified it.Results To seted the project parameters on TBA120 automatic biochemical analyzer and passed the calibration.The calibration fitting curve had a smooth trend and no obvious deviation with each measuring point.In the recovery tests,added standard liquid with different concentrations of 100 mg/L and 500 mg/L to the samples with low values,the recovery rate was 95.3％ and 102.7％ respectively.Same to the samples with high values,the recovery rate was 104.2％ and 103.5％ respectively.In the precision test,samples with low and high value had a precision CV of 6.52％ and 4.18％ respectively.The linear range was 0 ～ 1 100 mg/L,analysis sensitivity was 2.8 mg/L.In the interference test,found that,samples had no obvious disturbance to the test with lower concentrations of free bilirubin,combined with bilirubin,vitamin C,animal hemoglobin lower than 342 μmol/L,342 μmol/L,0.03 g/L,500 mg/L respectively,while had significant interference when the concentration of chyle was higher than 870 FTU.Their study had established the biological reference interval of healthy people,male was 0～ 13.3 mg/L and female 0 ～ 17.1 mg/L,there was no significant difference between them by a t test (P＞0.05).Conclusion The latex enhanced immune turbidimetric method for the detection of urine free hemoglobin has the performance of testing clinical urine specimen,which not only solved the lackage problem of specificity for occult blood in the urine dry chemistry test and realized batch automation quantitative detection.The experimental data of this study provides a theoretical basis for the application of the method in other types of clinical samples.

Determination of Bacterial Endotoxin in Iodixanol by Kinetic Turbidimetric Method / 中国药师

Objective:To establish a method to determine the content of bacterial endotoxin in iodixanol. Methods:The standard curve of kinetic turbidimetric method was established and the dilution ratio was optimized by interference test. Bacterial endotoxin in the samples was determined. Results:The dilution ratio of 1 ∶12 did not interfere with the test. The recovery rate of bacterial endotox-in was 50%-200%. Conclusion:The kinetic turbidimetric method is suitable for the determination of bacterial endotoxin in iodixanol.

Clinical Significance of Serum Cys C,HCY and mALB Joint Detection to HDCP Patients / 现代检验医学杂志

Objective To analysis clinical significance of joint detection of serum Cys C,Hcy and mAlb in HDCP patients. Methods Selected 92 cases of HDCP patients in Guangji hosipital of Hezhou from Jun 2011 to Jun 2014 as observation group.They were divided into three groups (43 patients of gestational hypertension as group A,32 patients with mild pre-eclampsia as group B,17 patients of severe preeclampsia as group C)and chose 50 cases of healthy maternal the same period in the hospital as control group.Enhanced turbidimetric method for the determination of serum Cys C,Hcy,immune scatter-ing method for urinary mAlb,the results were analyzed.Results Observation group with the level of serum Cys C,Hcy and urinary mAlb was rise with the damage degree aggravating,group C rise significantly (F =4.567,P <0.001).Observation group serum Cys C,Hcy and abnormal detection rate of urinary mAlb level was rise at the same time renal damage degree aggravating,group C rise significantly (χ2 = 12.842,P <0.001).Three joint detection indices abnormal detection rate was significantly higher than that of single detection (χ2 =5.869,P <0.001),the detection sensitivity of 95.70% has significant advantage (χ2 =15.992,P <0.001).Conclusion The joint detection of renal function of serum Cys C,Hcy and mAlb in HDCP patients was better than the single detection,which is helpful for the early detection of HDCP patients with renal damage,it’s worthy clinical promotion.

Comparison Analysis of the Results of Serum Anti CCP Antibody in Patients with RA by Two Methods / 现代检验医学杂志

Objective To compare diagnosis value and the clinical application of enzyme linked immunosorbent assay (ELISA) method and the immune turbidimetric method detecting serum anti cyclic citrullinated peptide (CCP)antibody in patients with RA.Methods Collected fresh serum specimen of 267 inpatients with RA in Rrheumatism Department of Xi’an Institu-te of Rheumatism from December 2014 to February 2015,and fresh serum specimen of 50 healthy blood donors from the Blood Center of Shaanxi Province respectively.Anti CCP antibody was detected by enzyme-linked immunosorbent assay (ELISA)method and the latex immunoturbidimetry assay.Evaluated the correlation of the results and clinical application to RA diagnosis.Results Sensitivity,specificity and diagnostic consistency of ELISA and latex immunoturbidimetry assay were 77.3%,86.8%,94.3% and 76.2%,80.2%,77.9% respectively.Compared two kinds of methods,the value of Kappa was 0.756,for having consistency.Throughχ2 test (χ2 =1.85,P >0.05),there was no significant difference between two meth-ods.Area of ELISA and lateximmunoturbidimetry under the ROC curve were 0.876 and 0.832 respectively.Conclusion De-tection of serum anti CCP antibody has diagnostic value in RA patients.The ELISA method and the latex immunoturbidime-try assay for detection of anti CCP antibodies had consistency.Two methods had no statistical difference,and the latex turbi-dimetric method is suitable for grassroots medical institutions.

A new generation of lipoprotein(a)in clinical application and performance evaluation method for the detection of particles per unit / 国际检验医学杂志

Objective To evaluate the clinical significance of the International Federation of Clinical Chemistry and Laboratory Medicine international(IFCC) reference reagent(SRM2B) standardized ,particles unit method in detecting the lipoprotein(a)[Lp (a)] .Methods Precision ,linearity ,clinical reportable range ,reference interval index of total number of particles in the kit express-ing Lp(a) by nmol/L were evaluated ,and compared with the kit expressed Lp(a) by mg/L .At the same time serum alanine amin-otransferase(ALT) ,aspartate aminotransferase(AST) ,total bilirubin(TBIL) ,UREA ,creatinine(CREA) ,triglycerides(TG) ,total cholesterol(CHOL) ,high-density lipoprotein cholesterol(HDL-C) ,low density lipoprotein cholesterol(LDL-C) of all the subjects were detected and the correlations of them between LP(a) were analyzed .Results The method with-run coefficient of variation (CV)<1 .5% ,between-run CV< 2 .0 .Within the scope of 0 .6 -236 .0 nmol/L the linear was good(r2 = 0 .996 2) .Reportable range:7-720 nmol/L ,normal reference range <75 nmol/L .With a total mass(mg/L) said good correlation between content Lp(a) kit .The correlation of Lp (a) and ALT ,AST ,TBIL ,UREA ,CERA ,TG ,CHOL ,HDL-C ,LDL-C of were -0 .120 ,-0 .091 ,-0 .372 ,-0 .096 ,-0 .087 ,0 .056 ,0 .263 ,0 .226 ,0 .159 .Conclusion This methods shows good performance ,and without interfer-ence from serum ALT ,AST ,UREA ,CERA ,TG ,HDL-C ,LDL-C levels ,but affected by the levels of serum TBIL and CHOL .It could be traced to the IFCC international reference methods and reference materials(SRM2B) ,which isn′t influenced by Lp(a) poly-morphisms ,detects Lp(a) particle number really ,expressed Lp(a) protein with nmol/L accurately ,helps evaluating clinical cardio-vascular disease risk ,and increases the comparability among different clinical research data .

Development and validation of a rapid turbidimetric assay to determine the potency of norfloxacin in tablets

Norfloxacin is one of the first commercially available (and most widely used) fluoroquinolone antibiotics. This paper reports the development and validation of a simple, sensitive, accurate and reproducible turbidimetric assay method to quantify norfloxacin in tablets formulations in only 4 hours. The bioassay is based on the inhibitory effect of norfloxacin upon the strain ofStaphylococcus epidermidis ATCC 12228 IAL 2150 used as test microorganism. The assay was performed 3x3 parallel lines like, three tubes for each concentration of reference substance and three tubes for each sample concentration. The results were treated statistically by analysis of variance and were found to be linear (r2 = 0.9999) in the selected range of 25-100 μg mL-1; precise (intra-assay: relative standard deviation (RSD) = 1.33%; inter-assay: RSD = 0.21%), accurate (100.74%) and robust with RSD lower than 4.5%. The student's t-test showed no statistically significant difference between the proposed turbidimetric method and an HPLC method previously validated. However the turbidimetric assay can be used as a valuable alternative methodology for the routine quality control of this medicine, complementary to other physical-chemical methods.

O norfloxacino foi a primeira fluorquinolona (e mais utilizada) disponível no mercado. Este trabalho divulga um novo desenvolvimento e validação de um método turbidimétrico simples, sensível, preciso e reprodutível para a quantificação de norfloxacino em comprimidos em apenas 4 horas. O bioensaio é baseado no efeito inibitório de norfloxacino sobre a cepa Staphylococcus epidermidis ATCC 12228 IAL 2150, utilizada como micro-organismo teste. O bioensaio foi efetuado através do delineamento de linhas paralelas 3x3, em que três tubos foram utilizados para a solução padrão e três tubos para as concentrações da amostra. Os resultados foram tratados estatisticamente pela análise de variância, apresentando coeficiente de correlação linear der2 = 0,9999, na faixa de 20 a 100 μg mL-1; precisão (intra-ensaio: desvio padrão relativo (RSD) 1,33%; inter-ensaio: RSD=0,21%), exatidão (100,74%) e robustez com RSD menor que 4,5%. O teste-tmostrou não haver diferença estatisticamente significativa entre o método turbidimétrico proposto e um método por HPLC previamente validado. No entanto, o ensaio turbidimétrico pode ser utilizado como método alternativo para o controle de qualidade de rotina para este antimicrobiano, como um complemento de outros métodos físico-químicos.

A Novel Method to Detect a New Biopolymer Material—Poly-?-Glutamic Acid / 中国生物工程杂志

A turbid solution was formed through the reaction between ?-PGA and cetylpyridinium chloride(CPC) and the turibidity was measured by using ultraviolet-visible spectroscopy at 680nm.The linearity between the concentration of ?-PGA and its absorbance,the stability,repeatability and recovery of the method were studied.Through the reaction of ?-PGA with CPC,a homogeneous turbid solution was formed.The turbid solution was stable in 3h under proper pH value and ion strength,the absorbance of the solution at 680nm had a good linear relationshi Pwith the concentration of ?-PGA in the range 12.5~50?g/ml(R2=0.9939).The recovery was within the range of 86%~99.75%(n=5).The relative standard division of the method for determining ?-PGA at the concentrations of 5,10 and 40?g/ml were 0.14%,0.23%和0.025% repeatability.The turbidmetric method has advantages of convenience,simplicity and good repeatability and can be used to control the quality of ?-PGA and its products.

Determination of the Potencies of Oxytetracycline Crude Drug and Its Tablets by Turbidimetric Method / 中国药房

OBJECTIVE:To establish a turbidimetric method for the determination of the potency of the crude drugs and tablets of oxytetracycline. METHODS: By turbidimetric method in which Staphylococcus aureus was used as the test organism with biomass concentration of 1.0%～1.5% (V/V). The culture temperature was 37 ℃ and the culture time was about 4 h. The method was compared with the cup-plate method in potency. RESULTS: The linear range of oxytetracycline was 0.05～0.4 IU?mL-1. The average recovery of the crude drug of oxytetracycline was 99.59% (RSD=2.0%) and that of oxytetracycline tablets was 99.51% (RSD=1.91%), showing no significant difference as compared with the cup-plate method in contents. CONCLUSIONS: The method was sensitive and rapid yet with few influencing factors thus applicable for the determination of the potencies of oxytetracycline and its tablets.