Establishment and application of quality evaluation method for Xiaochaihu Granules based on calibrator samples / 中国中药杂志

With reference to the production process documented in Chinese Pharmacopoeia, this paper prepared the calibrator samples of Xiaochaihu Granules from multiple batches and established a method for fingerprint analysis and content determination that could be used to evaluate Xiaochaihu Granules available in market. Multiple batches of Chinese herbal pieces contained in Xiaochaihu Granules were collected for preparing the calibrator samples according to the process in Chinese Pharmacopoeia. Following the establishment of fingerprints for calibrator samples by UHPLC, the method for determining the contents of saikosaponin B2, saikosaponin B1, baicalin, wogonoside, baicalein, liquiritin, glycyrrhizin G2 and glycyrrhizic acid in Xiaochaihu Granules was established. The experimental results showed that the fingerprints of calibrator samples had 26 common peaks, covering the chemical compounds of main herbs Bupleuri Radix, Scutellariae Radix, Changii Radix, Glycyrrhizae Radix et Rhizoma, and Rhizoma Zingiberis Recens. The similarity of fingerprints for 47 batches of Xiaochaihu Granules from 31 companies with the calibrator sample fingerprint ranged from 0.74 to 0.99, indicating good applicability of the established fingerprint. The contents of main components baicalin, saikosaponin B2, and glycyrrhizic acid in Xiaochaihu Granules were within the ranges of 22.917-49.108 mg per bag(RSD 19%), 0.28-2.19 mg per bag(RSD 62%), and 0.897-6.541 mg per bag(RSD 41%), respectively. The quality difference in saikosaponin B2, and glycyrrhizic acid among different manufacturers was significant. The fingerprint analysis and content determination method for calibrator samples of Xiaochaihu Granules prepared according to the production process in Chinese Pharmacopoeia has been proved suitable for evaluating the quality of Xiaochaihu Granules from different manufacturers. Saikosaponin B2, glycyrrhizic acid, and liquiritin should be added as content control indicators for Xiaochaihu Granules, aiming to further improve the product quality.

Current Approach in Radiochemical Quality Control of the 99mTc-Radiopharmaceuticals: a mini-review

Abstract To present optimized chromatographic systems for radiochemical purity (RCP) evaluation of 99mTc-eluate and 99mTc-radiopharmaceuticals, as well as to assess doses calibrator reliability for routine purposes in hospital radiopharmacies. RCP was determined by different systems and radioactivity was quantified by TLC-scanner, doses calibrator and gamma-counter. Suitable and optimized systems were presented for RCP analyses. No significant differences were observed between radioactivity counting devices and, thus, doses calibrator showed reliability for RCP determination in hospital radiopharmacies.

Selection and evaluation of calibrators for the conventional measurement system of serum α-Amylase / 临床检验杂志

Objective To select the calibrator for the conventional measurement system of serum a-Amylase (Amy).Methods The Amy levels of forty frozen serum samples were detected by the IFCC reference method (reference system),the conventional system A which used the Bioassay routine reagent and Randox calibrator,and was calibrated by the Roche PNPG7 method,and the conventional system B which used the Bioassay routine reagent and Randox calibrator,and was calibrated by the Rondox liquid stable PNPG7 method,respectively,and the acceptability of the two conventional systems was evaluated.Results The regression equations of the measurement values between the IFCC reference method and the conventional systems A and B were Y =0.964X +0.376 and Y =1.095X + 3.131,respectively.Among them,X and Y represented the results of the IFCC reference method and the conventional system,respectively.Compared with the IFCC reference method,the results of the conventional system A was reliable.Condusion With the guidance of the IFCC reference method,the domestic biochemical reagents matched with the suitable calibrators may provide the acceptable results.

Dose calibrator linearity test: 99mTc versus 18F radioisotopes / Teste de linearidade em medidor de atividade: utilização do radioisótopo 99mTc versus 18F

Objective: The present study was aimed at evaluating the viability of replacing 18F with 99mTc in dose calibrator linearity testing. Materials and Methods: The test was performed with sources of 99mTc (62 GBq) and 18F (12 GBq) whose activities were measured up to values lower than 1 MBq. Ratios and deviations between experimental and theoretical 99mTc and 18F sources activities were calculated and subsequently compared. Results: Mean deviations between experimental and theoretical 99mTc and 18F sources activities were 0.56 (± 1.79)% and 0.92 (± 1.19)%, respectively. The mean ratio between activities indicated by the device for the 99mTc source as measured with the equipment pre-calibrated to measure 99mTc and 18F was 3.42 (± 0.06), and for the 18F source this ratio was 3.39 (± 0.05), values considered constant over the measurement time. Conclusion: The results of the linearity test using 99mTc were compatible with those obtained with the 18F source, indicating the viability of utilizing both radioisotopes in dose calibrator linearity testing. Such information in association with the high potential of radiation exposure and costs involved in 18F acquisition suggest 99mTc as the element of choice to perform dose calibrator linearity tests in centers that use 18F, without any detriment to the procedure as well as to the quality of the nuclear medicine service. .

Objetivo: Avaliar a viabilidade de substituir o radioisótopo 18F pelo 99mTc no teste de linearidade em medidores de atividade. Materiais e Métodos: O teste foi realizado empregando-se fontes de 99mTc (62 GBq) e 18F (12 GBq), cujas atividades foram mensuradas até valores abaixo de 1 MBq. As razões e desvios entre as atividades experimentais e teóricas foram calculados e comparados. Resultados: Os desvios médios entre as atividades experimentais e teóricas para o 99mTc e 18F foram, respectivamente, 0,56 (± 1,79)% e 0,92 (± 1,19)%. A razão média entre as atividades indicadas pelo equipamento para a fonte de 99mTc quando mensurada no equipamento pré-ajustado para medir o 99mTc e 18F foi 3,42 (± 0,06), e para o 18F este valor foi 3,39 (± 0,05), razões consideradas constantes ao longo de todo o período de medida. Conclusão: Os resultados do teste utilizando o 99mTc são compatíveis com os adquiridos com o 18F, implicando na possibilidade de utilização de ambos os radioisótopos na realização do teste de linearidade. Esta informação, aliada ao elevado potencial de exposição e custos de aquisição do 18F, sugere que o 99mTc seja empregado na realização do teste de linearidade para clínicas que utilizam 18F, sem prejuízo para o procedimento e garantia da qualidade de um serviço de medicina nuclear. .

Development of portable negative pressure calibrator / 中国医学装备

Objective: Develop a kind of portable negative pressure calibrator by the design and implement of method. Methods:By the working principle of negative pressure sensor and gas flow sensor, the negative pressure aspirator realizes the calibration function and stability of the monitoring function of the pressure and flow. Results:Stating from the design concept, this portable negative pressure can satisfy the requirement of the quality control and test work. Conclusion:Guarantee the accuracy and efficiency in the clinical first aid and field battle when using attractor. This avoids attractor of iatrogenic injury accident caused by negative pressure fall off.

Fatores de correção volumétrica na medição de atividade de 99mTc e 123I em calibradores de radionuclídeos / Volume corrections factors in the measurement of 99mTc and 123I activities in radionuclide calibrators

OBJETIVO: Determinar os fatores de correção para a variação volumétrica dos radiofármacos contidos em recipientes de diferentes geometrias. Comparar a influência desses fatores na determinação da atividade de 99mTc e 123I utilizando dois tipos de calibradores: um com câmara de ionização e outro com detector Geiger-Müller (G-M). Avaliar o desempenho de calibradores de alguns serviços de medicina nuclear em medição de atividade de 99mTc e 123I. MATERIAIS E MÉTODOS: Foram utilizados oito calibradores, frascos de vidro 10R, seringas de plástico de 3 e 5 mL e soluções de 99mTc e 123I. Os fatores de correção foram determinados a partir das medições práticas da variação da leitura do calibrador com a variação do volume da solução no recipiente. O desempenho foi avaliado em relação ao critério de aceitação de ±10% de exatidão exigida pela norma brasileira. RESULTADOS: A variação da resposta do calibrador com a variação do volume do frasco foi bem maior no calibrador que utiliza G-M. Ela também foi maior para 123I do que para 99mTc. CONCLUSÃO: Os resultados confirmam que a resposta dos calibradores depende do volume contido nos recipientes. Essa dependência é mais crítica para os calibradores equipados com detector G-M e para 123I quando comparado com 99mTc.

OBJECTIVE: To determine correction factors for the variation in volume of radiopharmaceuticals in containers of different geometries, comparing the influence of such factors on the determination of 99mTc and 123I activity with two types of calibrators - one with ionization chamber and another with Geiger-Müller (G-M) detector -; and to evaluate calibrators performance in the measurement of 99mTc and 123I activities. MATERIALS AND METHODS: Eight calibrators, 10R glass vials, 3 and 5 mL plastic syringes and 99mTc and 123I solutions were utilized. The correction factors were determined with basis on practical measurements of the variation in the calibrators' response according to the volume of radionuclide solution in the glass vials. The performance was evaluated according to the acceptance criterion of ±10% accuracy required by the Brazilian standard. RESULTS: The variation of the calibrators' response according to the variation in radionuclide volume was reasonably greater in the calibrator with G-M detector. It was also greater for 123I than for 99mTc. CONCLUSION: The results confirm that the calibrators' response depends on the radionuclide volume contained in the vials. Such dependence is more critical for the calibrators equipped with G-M detector and for 123I as compared with 99mTc.

Comparison of Radioactivity Measurement with Radionuclide Calibrators in Nuclear Medicine Centers / 의학물리

To acquire good image quality and to minimize unnecessary radiation dose to patients, it is important to ensure that the radiopharmaceutical administered is accurately measured. Quality control of radionuclide calibrators should be performed to achieve these goals. The purpose of this study is to support the quality control of radionuclide calibrators in nuclear medicine centers and to investigate the level of measurement accuracy of the radionuclide calibrators. 58 radionuclide calibrators from 45 nuclear medicine centers, 74 radionuclide calibrators from 58 nuclear medicine centers, and 60 radionuclide calibrators from 45 nuclear medicine centers were tested with I-131, Tc-99m and I-123, respectively. The results showed that 81% of calibrators for I-131, 61% of calibrators for Tc-99m and 67% of calibrators for I-123 were within +/-5%. 17% of calibrators for I-131, 20% of calibrators for Tc-99m and 15% of calibrators for I-123 had a deviation in the range 5%10%. Follow-up measurements were performed on the calibrators whose error exceeded the +/-10% limit. As a result, some of the calibrator showed an improvement and their deviation decreased below the +/-10% limit. The results have shown that such comparisons are necessary to improve the accuracy of the measurement and to identify malfunctioning radionuclide calibrators.

Teste de proficiência para medições de radioatividade na medicina nuclear / Proficiency test for radioactivity measurements in nuclear medicine

OBJETIVO: Avaliar o desempenho dos calibradores de radionuclídeos de 55 serviços de medicina nuclear brasileiros em medição de atividade de radiofármaco contendo 99Tc m. Testes de proficiência foram aplicados em 63 resultados originados do programa de comparação promovido pelo Laboratório Nacional de Metrologia das Radiações Ionizantes do Instituto de Radioproteção e Dosimetria. MATERIAIS E MÉTODOS: O desempenho foi avaliado em relação ao critério de aceitação de ±10 por cento de exatidão exigido pela norma brasileira e também aos critérios estabelecidos pela ISO/IEC Guide 43-1, e classificado como "aceitável" ou "não aceitável". Amostras de 99Tc m usadas nas comparações foram fornecidas por alguns dos participantes e calibradas no Laboratório Nacional de Metrologia das Radiações Ionizantes para determinar o valor de referência da atividade. RESULTADOS: Esta comparação com o 99Tc m mostrou que o desempenho aceitável atendendo à exigência da norma regulatória foi de 82,5 por cento, enquanto pelos critérios estabelecidos pela norma ISO/IEC 43-1 foi de 81,0 por cento. Por outro lado, calibradores de radionuclídeos com detector Geiger-Müller apresentaram desempenho inferior quando comparados com os dotados com câmara de ionização. CONCLU-SÃO: Nesta comparação, a avaliação do desempenho baseada nos critérios da ISO/IEC 43-1, os quais são aplicados a laboratórios analíticos, apesar de serem mais restritivas, foi bastante consistente com o critério de exatidão exigido pela norma nacional.

OBJECTIVE: To assess the performance of radionuclide calibrators in 55 Brazilian nuclear medicine services in the measurement of 99Tc m radiopharmaceutical activity. Proficiency tests were applied to data sets with 63 results originated from the comparison program developed by Laboratório Nacional de Metrologia das Radiações Ionizantes of Instituto de Radioproteção e Dosimetria. MATERIALS AND METHODS: The calibrators' performance was evaluated in compliance with the acceptance criterion of ±10 percent accuracy required by the Brazilian standards and also the criteria established by the ISO/IEC Guide 43-1, and classified as either "acceptable" or "non-acceptable". The samples of 99Tc m utilized in the comparison were supplied by some of the participants and calibrated at Laboratório Nacional de Metrologia das Radiações Ionizantes for determining the activity reference value. RESULTS: The present study utilizing 99Tc m has shown that 82.5 percent of the calibrators were considered as acceptable according to the Brazilian standards, while by the criteria established by ISO/IEC 43-1, 81.0 percent were considered as acceptable. On the other hand, radionuclide calibrators with Geiger-Müller detectors presented unsatisfactory performance when compared with calibrators with ionization chambers. CONCLUSION: The performance evaluation based on the ISO/IEC 43-1 criteria, which are applied to analytical laboratories, in spite of being more restrictive, has demonstrated to be quite consistent with the accuracy criterion established by the Brazilian standard.

Comparison of F-18 FDG Radioacitivity to Determine Accurate Dose Calibrator Activity Measurements / 의학물리

Obviously, the administration of the prescribed amount of activity to the patient requires proper operation of the dose calibrator, which shall be verified by implementing the required quality control on the instrument. This investigation examined the accuracy and precision of dose calibrator activity measurement of the radiopharmaceutical F-18 FDG. To investigate the status of the nuclear medicine centers in Korea for the performance of dose calibrators, 10 centers providing PET/CT system services in Korea were inspected in 2008. We measured accuracy and precision in 10 equipments in consideration of PET/CT model, installation area, and installation time. According to the results of comparative analysis of 10 dose calibrators used to measure radioactivity of F-18 FDG, accuracy was -5.00~4.50% and precision was 0.05~0.45%, satisfying the international standards, which are accuracy +/-10% and precision +/-5%. This study demonstrated that, for accurate measurements, no adjustment is necessary for a dose calibrator setting when measuring different dose calibrators of F-18 FDG activity prescriptions.

Comparison of F-18 FDG Radioacitivity to Determine Accurate Dose Calibrator Activity Measurements / 의학물리

Obviously, the administration of the prescribed amount of activity to the patient requires proper operation of the dose calibrator, which shall be verified by implementing the required quality control on the instrument. This investigation examined the accuracy and precision of dose calibrator activity measurement of the radiopharmaceutical F-18 FDG. To investigate the status of the nuclear medicine centers in Korea for the performance of dose calibrators, 10 centers providing PET/CT system services in Korea were inspected in 2008. We measured accuracy and precision in 10 equipments in consideration of PET/CT model, installation area, and installation time. According to the results of comparative analysis of 10 dose calibrators used to measure radioactivity of F-18 FDG, accuracy was -5.00~4.50% and precision was 0.05~0.45%, satisfying the international standards, which are accuracy +/-10% and precision +/-5%. This study demonstrated that, for accurate measurements, no adjustment is necessary for a dose calibrator setting when measuring different dose calibrators of F-18 FDG activity prescriptions.

Design and improvement of medical radioisotope dose calibrator / 国际生物医学工程杂志

Objective To improve the hardware of a medical radioisotope dose calibration system base on LabVIEW platform.Methods Hiish performance voltage-frequency-converter VFC32 was applied to realize hardware circuit design of medical radioisotope dose calibrator,and the function of the circuit wag analyzed.The output voltage signal from the calibrator ionization chamber was processed by the designed circuit.The output frequency signal from the circuit was obtained by USB-6009 DAQ and was then processed by virtual instrument designed using LabVIEW 8.0.Results Experimental data graphs indicated that the improved system had a better linearity in the low and medium frequency band.Conclusion The redesigned radioisotope dose calibrator has advantages in improving measuring accuracy,measuring range,feeble-minded detection limit and so on.

Primary study on stability and commutability of recombinant human muscle creatine kinase isozyme in different matrix / 临床检验杂志

Objective To investigate the stability and comparability of recombinant human muscle creatine kinase isozyme(CK-MM)in different matrix,and to find out a suitable matrix as a reference material for application of CK measurement system.Methods The stability of the recombinant CK-MM was observed by measuring its catalytic activity in self-made matrix,anti-freeze additive matrix,the certified reference material(CRM)matrix and human serum matrix respectively.For understanding the commutability among different measurement system total CK catalytic activity in various concentration of human serum and the catalytic activity of recombinant CK-MM in different matrix specimen were measured with IFCC recommended reference method and routine reagent produced by Roche and Zhongsheng Diagnostic Company respectively.Results The recombinant CK-MM was stable for 25 days in the self-made matrix,23 days in CRM matrix and at least 240 days in antifreeze additive matrix stored at-20 ℃.The recombinant enzyme protein in self-made matrix and CRM matrix was commutable.Low concentrations of recombinant CK-MM in human serum and in anti-freeze additive matrix were also commutable.Conclusion The recombinant CK-MM had good stability and commutability in either self-made matrix or CRM matrix.It might be used as a candidate reference material for the determination of total creatine kinase in serum.

Studies on standardization of serum enzyme determination / 中华检验医学杂志

Objective Investigating for the standardization of serum enzyme determination by using enzyme calibrator in lab tests Methods 150 laboratories were involved in this program. One enzyme calibrator and three patient samples were send to each participate lab The calibrator was tested using routine method and record the results The patient samples were analyzed before and after calibration Record the results All lab data was processed with computer Results Compare with the target values, the bias of alanine aminotransferase (ALT), aspartate aminotransferase (AST), amylase (AMY) and lactate dehydrogenase (LD) assays were 3 8%, -1 8%, 2 3% and -5 2% respectively, the bias of alkaline phosphatase (ALP), gamma glutamyltransferase (GGT) and creatine kinase (CK) assays were 13 7%, -13 9 and -19 2% respectively The precision of the enzyme assays were improved by using calibrators Conclusions The traceability of ALT, AST, AMY and LD assays were reasonable Calibrating by using enzyme calibrator can improve the assay precision among laboratories

Reference method applied to assigning values for calibrators in serum gamma-glutamyltransferase assays / 中华检验医学杂志

Objective To investigate the efficacy of using a calibrator with values assigned with the reference method for improving the comparability of serum gamma-glutamyltransferase (GGT) measurements.Methods The IFCC reference method for GGT was established and the performance was verified by testing a certified reference material (CRM).A calibrator was prepared and its value for GGT was assigned with the reference method.Forty serum samples were measured on different (including HITACHI 7600,7060,7170,7180 and BECKMAN LX20,OLYMPUS AU 400) chemistry analyzers with Zhongsheng GGT reagent kits calibrated with the calibrator.The samples were also measured on the same analyzers using a theoretical factor.Biases of results obtained with the calibration and with the theoretical factor based calculation were compared.Results The reference method resuhs on the CRM agreed the certified value within the stated uncertainty.Serum results calculated from the theoretical factor showed various biases and inter-analyzer variations.When the analyzers were calibrated with the calibrator,the number of results with biases less than 10% became significantly higher and those with biases more than 20% significantly lower.The variation of the results on 5 serum samples was reduced from 11.0%～14.0% to less than 5% by using the calibrator.Conclusion Accuracy and comparability of GGT measurements with of ZhongSheng GGT kits can be improved by using a calibrator that has a value assigned with the reference method.

High-level expression and purification of human creatine kinase MM isozymes in E.coli / 临床检验杂志

Objective To construct a prokaryotic expression system for human creatine kinase(CK) MM isozyme,purify the recombinant protein of CK expressed in Eschericheia coli(E.coli) and examine the stability of the recombinant protein for its application in CK measurement system as the quality control.Methods Total RNA of extracted from fetal cardiac muscle was reversetranscripted and cDNA encoding human CK was amplified which was inserted into pET-15b plasmid vector.The recombinant plasmid was transfered into E.coli BL21(DE3) and induced by isopropyl-?-D-thiogalactopyranoside(IPTG).Recombinant CK-MM was separated from bacterial proteins by affinity chromatography on a Ni2+-Sepharose column.The activity of the recombinant enzyme was observed in different matrixes.Results The enzymatic activity of the crude extracts of CK-MM was up to 280,000U/L.After one step affinity chromatography,the fusion protein showed a single band in SDS-PAGE gel.The purified protein was stable and the enzymatic activity remained unchanged for a month in the matrix containing bovine serum albumin,EDTA and 1,4-Dithiothreitol(DTT).Conclusion The recombinant CK-MM showed key properties of the native creatine kinase isozyme and may be used as control and calibrator for determination of serum CK-MM.