A nomogram based on clinicopathological features and serological indicators predicting breast pathologic complete response of neoadjuvant chemotherapy in breast cancer.

A single tumor marker is not enough to predict the breast pathologic complete response (bpCR) after neoadjuvant chemotherapy (NAC) in breast cancer patients. We aimed to establish a nomogram based on multiple clinicopathological features and routine serological indicators to predict bpCR after NAC in breast cancer patients. Data on clinical factors and laboratory indices of 130 breast cancer patients who underwent NAC and surgery in First Affiliated Hospital of Xi'an Jiaotong University from July 2017 to July 2019 were collected. Multivariable logistic regression analysis identified 11 independent indicators: body mass index, carbohydrate antigen 125, total protein, blood urea nitrogen, cystatin C, serum potassium, serum phosphorus, platelet distribution width, activated partial thromboplastin time, thrombin time, and hepatitis B surface antibodies. The nomogram was established based on these indicators. The 1000 bootstrap resampling internal verification calibration curve and the GiViTI calibration belt showed that the model was well calibrated. The Brier score of 0.095 indicated that the nomogram had a high accuracy. The area under the curve (AUC) of receiver operating characteristic (ROC) curve was 0.941 (95% confidence interval: 0.900-0.982) showed good discrimination of the model. In conclusion, this nomogram showed high accuracy and specificity and did not increase the economic burden of patients, thereby having a high clinical application value.

Calculation of an Apical Efflux Ratio from P-Glycoprotein (P-gp) In Vitro Transport Experiments Shows an Improved Correlation with In Vivo Cerebrospinal Fluid Measurements in Rats: Impact on P-gp Screening and Compound Optimization.

P-glycoprotein (P-gp) is a major blood-brain barrier (BBB) efflux transporter. In vitro approaches, including bidirectional efflux ratio (ER), are used to measure P-gp-mediated transport, but findings can be inconsistent across models. We propose a novel, more physiologically relevant, in vitro model: unidirectional apical efflux ratio (AP-ER)-a ratio of permeability rates at the apical side of the BBB with and without P-gp inhibitor. To test our approach, ER and AP-ER were calculated for 3227 structurally diverse compounds in porcine kidney epithelial cells (LLC-PK1) overexpressing human or mouse P-gp and classified based on their passive transcellular P-gp permeability or charged properties. In vivo rat infusion studies were performed for selected compounds with high ER but low AP-ER. One-third of the 3227 compounds had bidirectional ER that was much higher than AP-ER; very few had AP-ER higher than ER. Compounds with a large difference between AP-ER and ER were typically basic compounds with low-to-medium passive permeability and high lipophilicity and/or amphiphilicity, leading to strong membrane binding. Outcomes in the human model were similar to those in mice, suggesting AP-ER/ER ratios may be conserved for at least two species. AP-ER predicted measured cerebrospinal fluid (CSF) concentration better than ER for the five compounds tested in our in vivo rat infusion studies. We report superior estimations of the CSF concentrations of the compounds when based on less resource-intensive AP-ER versus classic ER. Better understanding of the properties leading to high P-gp-mediated efflux in vivo could support more efficient brain-penetrant compound screening and optimization. SIGNIFICANCE STATEMENT: To address inconsistencies associated with the historical, bidirectional efflux ratio (ER) calculation of P-glycoprotein-mediated transport, we propose to use the novel, more physiologically relevant, unidirectional apical efflux ratio (AP-ER) model. In vitro experiments suggested that compounds with strong membrane binding showed the largest difference between AP-ER and ER, and in vivo infusion studies showed that AP-ER predicted cerebrospinal fluid concentrations of compounds better than ER; outcomes in the human model were similar to those in mice.

Toxicity profiling of the ethanolic extract of Citrullus lanatus seed in rats: behavioral, biochemical and histopathological aspects.

Citrullus lanatus (Cucurbitaceae) is conventionally used for the treatment of urinary tract infection, renal stones, hypertension, diabetes and diarrhoea. Current study evaluates acute and 28 days repeated toxicity ethanolic extract of C. lanatus seed (EECLS) in Wistar rats to measure its safety profile. The single dose (2000 mg/kg BW) of EECLS was administered while in 28 days repeated study 250, 500 and 1000 mg/kg BW were administered orally in rats. Parameters such as biochemical, haematological and histopathological were analysed in subacute toxicity study. During study, no apparent sign of toxicity, behavioural changes and mortality were detected in acutely exposed animals. In 28 days repeated toxicity study, rats did not show significant changes in behaviour, gross pathology, body weight, biochemical and haematological parameters. Abridged serum glucose and cholesterol levels during the study designate their roles in treatment of hyperglycaemic and hyperlipidaemic conditions. No significant difference was observed in histopathology of liver and kidneys of treated rats. The current investigation demonstrated that EECLS is non-toxic below 1000 mg/kg BW and provides protection to some body organs. The data propose that LD50 of EECLS was greater than 2000 mg/kg BW and the no observed adverse effect level (NOAEL) of EECLS was at the dose of 1000 mg/kg in rats. Taken together, our finding suggests that, EECLS is safe and provides some protection to body organs; also, its extract can be used for further preclinical and clinical evaluation for its therapeutic activity.

Establishment of reference intervals for immunoassay analytes of adult population in Saudi Arabia.

Background This is a second part of report on the IFCC global multicenter study conducted in Saudi Arabia to derive reference intervals (RIs) for 20 immunoassay analytes including five tumor makers, five reproductive, seven other hormones and three vitamins. Methods A total of 826 apparently healthy individuals aged ≥18 years were recruited in three clinical laboratories located in western, central and eastern Saudi Arabia using the protocol specified for the global study. All serum specimens were measured using Abbott, Architect analyzers. Multiple regression analysis (MRA) was performed to explore sources of variation of each analyte: age, body mass index (BMI), physical exercise and smoking. The magnitude of variation of reference values (RVs) attributable to sex, age and region was calculated by ANOVA as a standard deviation ratio (SDR). RIs were derived by the parametric (P) method. Results MRA revealed that region, smoking and exercise were not relevant sources of variation for any analyte. Based on SDR and actual between-sex differences in upper limits (ULs), we chose to partition RIs by sex for all analytes except for α-fetoprotein and parathyroid hormone (PTH). Age-specific RIs were required in females for ferritin, estradiol, progesterone, testosterone, follitropin, luteotropin and prolactin (PRL). With prominent BMI-related increase, RIs for insulin and C-peptide were derived after excluding individuals with BMI > 32 kg/m2. Individuals taking vitamin D supplements were excluded in deriving RIs for vitamin D and PTH. Conclusions RIs of major immunoassay analytes specific for Saudi Arabians were established in careful consideration of various biological sources of variation.

Effects of Orally Consumed Rosa damascena Mill. Hydrosol on Hematology, Clinical Chemistry, Lens Enzymatic Activity, and Lens Pathology in Streptozotocin-Induced Diabetic Rats.

Diabetes mellitus is a multisystemic metabolic disorder that may affect the eyes, kidneys, vessels, and heart. Chronic hyperglycemia causes non-enzymatic glycation of proteins and elevation of the polyol pathway resulting in oxidative stress that damages organs. The current study aimed to investigate the dose-dependent effects of orally consumed Rosa damascena Mill. hydrosol on hematology, clinical biochemistry, lens enzymatic activity, and lens pathology in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced into male Sprague-Dawley rats by intraperitoneal administration of STZ (40 mg/kg body weight). Rose hydrosols containing 1515 mg/L and 500 mg/L total volatiles (expressed as citronellol) were introduced to rats orally for 45 days. Consumption of 1515 mg/L volatile containing rose hydrosol successfully ameliorated hematologic, hepatic, and renal functions. Hydrosols also attenuated hyperglycemia and decreased the advanced glycation end-product formation in a dose-dependent manner. Rose hydrosol components significantly increased the lens enzymatic activities of glutathione peroxidase and decreased the activity of aldose reductase to prevent cataractogenesis. Histopathological examinations of rat lenses also indicated that increasing the dose of rose hydrosol had a protective effect on lenses in diabetic conditions. Additionally, in silico modeling of aldose reductase inhibition with rose hydrosol volatiles was carried out for extrapolating the current study to humans. The present results suggest that rose hydrosol exerts significant protective properties in diabetes mellitus and has no toxic effect on all studied systems in healthy test groups.

Patient's knowledge and awareness about the effect of the over-the-counter (OTC) drugs and dietary supplements on laboratory test results: a survey in 18 European countries.

Background Nowadays over-the-counter (OTC) drugs and dietary supplements are widely used. Their use can have a significant impact on the validity of laboratory results. The aim of this multicenter European study was to determine the frequency of consumption of various dietary products and OTC drugs among patients and explore their level of knowledge and awareness about the potential impact of various products on laboratory test results. Methods Eighteen European countries participated in this study. The survey was carried out anonymously on a subsequent series of outpatients (n=200) in each participating country. Included were patients who were referred to the laboratory for blood sampling and who voluntarily agreed to participate in the study. The survey included questions about the frequency of consumption of various products, awareness of the importance of informing physicians and laboratory staff about it and information about influence of preanalytical factors in general on laboratory test results. Results In total, 68% of patients were regularly taking at least one OTC drug or dietary supplement. The frequency of patients consuming at least one OTC drug or dietary supplement differed between countries (p=0.001). Vitamins (38%), minerals (34%), cranberry juice (20%), acetylsalicylic acid (ASA) (17%) and omega fatty acids (17%) were the most commonly used in our study. Conclusions The use of various OTC drugs and dietary supplements is highly prevalent in Europe and patients are often not willing to disclose this information to the laboratory staff and ordering physician. The education of both patients and healthcare staff is needed.

Evaluation of 5 methods for diagnosing failure of passive transfer in 160 Holstein calves.

BACKGROUND: Inadequate absorption of colostral IgG1 is termed failure of transfer of passive immunity (FTPI). Dairy calves with FTPI have increased mortality and morbidity in their first 6 months of life. OBJECTIVES: This study compared the clinical performance of 5 methods for diagnosing FTPI in Holstein calves. METHODS: An observational study was performed using 160 Holstein heifer calves. Serum was harvested at 48 hours of age, and FTPI was assessed using a digital Brix refractometer for total solids measurements, and digital refractometry and the biuret method to measure serum total protein (STP) concentrations. Serum gamma-glutamyltransferase activity was measured with an automated analyzer, and serum IgG was measured with the zinc sulfate turbidity test and an enzyme-linked immunosorbent assay. Diagnostic test performance was compared with that of the reference method (FTPI defined as a serum total IgG concentration <10 g/L). Test performance was evaluated using the area under the receiver operating characteristic curve, the sensitivity, the specificity, and the positive likelihood ratio at the optimal test cut point, and by calculating the kappa coefficient. RESULTS: A serum digital Brix percentage of <7.8% and an STP concentration of <52 g/L measured using digital refractometry were the best methods to identify calves with FTPI. The STP concentration measured with digital refractometry was 0.1 g/L lower than that measured with the biuret method. CONCLUSIONS: The digital Brix refractometer and the digital refractometer provide accurate and clinically useful methods for identifying dairy calves with FTPI. In this study, the excellent performance of the Brix refractometer was likely due to the use of a fixed sample volume (200 µL) and a uniform sample temperature at the time of measurement.

Analysis of the influence of the T393C polymorphism of the GNAS gene on the clinical expression of primary hyperparathyroidism / Análisis de la influencia del polimorfismo T393C del gen GNASen la expresión clínica del hiperparatiroidismo primario

Background: The receptor of parathyroid hormone and parathyroid hormone-related-protein (PTH/PTHrp) is located in the cell membrane of target tissues - kidney and osteoblasts. It is a G protein-coupled-receptor whose Gsα subunit is encoded by the GNAS gene. Our aim was to study whether the single nucleotide polymorphism (SNP) T393C of the GNAS gene is associated with renal stones, bone mineral density (BMD), or bone remodelling markers in primary hyperparathyroidism (PHPT).Methods: An analysis was made of clinical and biochemical parameters and densitometric values in three areas and their relationship with the T393C SNP of the GNAS gene in 261 patients with primary hyperparathyroidism and in 328 healthy controls. Genotyping was performed using the Custom Taqman(R) SNP Genotyping assay. Results: The genotype frequencies of GNAS T/C 393 were similar in the control and PHPT groups. No association was found between genotypes and clinical expression of PHPT (renal stones and bone fractures). A nonstatistically significant trend was seen to lower BMD in the lumbar spine, femoral neck, and total hip in both PHPT and control C homozygote subjects. Conclusion: Genetic susceptibility to PHPT related to the GNAS T393C polymorphism or a major influence in its development and clinical expression were found. A C allele-related susceptibility to lower BMD in trabecular bone in both PHPT and control subjects is not sufficient to suggest a more severe clinical expression of PHPT. This trend may be considered as a basis for further studies with larger sample sizes and complementary functional evaluation (AU)

Introducción: El receptor de la hormona paratiroidea y de la proteína relacionada con la hormona paratiroidea (PTH/PTHrp) está situado en la membrana celular de sus tejidos diana: riñón y osteoblastos. Se trata de un receptor unido a proteina G cuya subunidad Gsα está codificada por el gen GNAS. Nuestro objetivo fue estudiar si el polimorfismo de un sólo nucleótido (SNP) T393C del gen GNAS se asociaba con litiasis renal, densidad mineral ósea (DMO) o marcadores de remodelado óseo en el hiperparatiroidismo primario (HPTP). Métodos: Analizamos parámetros clínicos, bioquímicos y densitométricos en 3 zonas y su relación con el SNP T393C del gen GNAS en 261 pacientes con HPTP y en 328 controles sanos. El genotipado se realizó utilizando el ensayo Custom Taqman(R). Resultados: Las frecuencias genotípicas del SNP T/C 393 del GNAS fueron similares en ambos grupos control y HPTP. No encontramos ninguna asociación entre los genotipos y la expresión clínica del HPTP (litiasis renal y fracturas óseas). Encontramos una tendencia no estadísticamente significativa hacia una menor DMO en columna lumbar, cuello femoral y cadera en los sujetos control y HPTP portadores del alelo C. Conclusiones: No encontramos susceptibilidad genética para el desarrollo de PHPT relacionada con el polimorfismo T393C del gen GNAS ni influencia en su expression clínica. Sí hallamos una tendencia hacia niveles menores de DMO en el hueso trabecular relacionada con el alelo C en pacientes con PHPT y en sujetos control sin ser suficiente para sugerir una expresión clínica más grave. Estos resultados pueden ser considerados como un punto de partida para futuros estudios con mayor tamaño muestral y con evaluación funcional complementaria (AU)

Using Sigma Quality Control to Verify and Monitor Performance in a Multi-Instrument, Multisite Integrated Health Care Network.

The authors developed a system-wide integrated network of instrumentation and Sigma-based quality control for fundamental chemistry, coagulation, and hematology analysis. The authors have based selection of Westgard rules for run management on a straightforward, Sigma-driven selection process. The network includes multiple hospitals and large regional clinic laboratories. Most hospitals have multiple instruments; overall there are at least four distinct instrument models active from each manufacturer. The authors have measured and monitored Sigma values in this network for more than five years, to verify and validate performance and to provide ongoing justification for rules selection and rules changes when necessary.

Determination of CSF 5-methyltetrahydrofolate in children and its application for defects of folate transport and metabolism.

OBJECTIVE: To describe an assay of 5-methyltetrahydrofolate (5MTHF) in the cerebrospinal fluid (CSF) of children, to determine reference values, and to report the clinical significance of this assay in metabolic disorders affecting folate transport and metabolism. METHODS: CSF 5MTHF was determined by high-performance liquid chromatography with fluorescent detection in pediatric patients including one with FOLR1 gene mutation and one with methylenetetrahydrofolate reductase (MTHFR) deficiency. CSF total folate was measured using an automated analyzer. RESULTS: 5MTHF and total folate were determined in 188 and 93 CSF samples, respectively. CSF 5MTHF was high throughout the first six months of life and subsequently declined with age. Reference values of CSF 5MTHF and total folate were determined from 162 and 82 samples, respectively. The patient with FOLR1 gene mutation had extremely low CSF 5MTHF and total folate, though these values normalized after folinic acid supplementation. The patient with MTHFR deficiency had extremely low 5MTHF and moderately low total folate; these values were not associated and showed no significant change after folic acid supplementation. CONCLUSIONS: This 5MTHF assay is simple, rapid, sensitive, reliable, and cost-effective. It will aid in the diagnosis and therapeutic monitoring of metabolic disorders affecting folate transport and metabolism.

Comparison of the transcutaneous bilirubinometers BiliCare and Minolta JM-103 in late preterm and term neonates.

OBJECTIVES: To assess the agreement of transcutaneous bilirubin (TcB) measurement with the Bilicare™ System in comparison to TcB measured with JM-103™ and total serum bilirubin (TSB). METHODS: Caucasian infants with gestational age ≥35 weeks with non-hemolytic jaundice received TcB measurement with both Bilicare™ and JM-103™ devices. TSB was also obtained in infants at risk of phototherapy. RESULTS: We studied 458 infants measuring TcB with Bilicare™ and JM-103™, correlating the results and with TSB. The mean difference ± 2SD between Bilicare™ and JM-103™ TcB was 2.02 ± 4.46 mg/dL and decreased from 2.88 ± 3.17 to 1.20 ± 4.55, and to -0.95 ± 4.58 mg/dL at mild, moderate and high TcB values, respectively. CONCLUSIONS: Bilicare™ and JM-103™ TcB measurements are well correlated, but Bilicare™ over-estimates TcB for mild and moderate values and under-estimates it for high values compared to JM-103™. This could increase the prescription of TSB measurements for less serious cases and decrease them in the most worrisome.

Challenges in harmonizing integrated healthcare network laboratories: multi-center evaluation of the hCG5 assay.

BACKGROUND: Beckman Coulter recently introduced a new hCG assay manufactured for the Access 2 and DxI platforms. This assay is the first to use the 5th International Standard (5th IS) as its primary calibration material. Clinical laboratories are required to validate the method performance before testing and reporting patient results. METHODS: Beckman Coulter Access 2 instruments (n=41) across Kaiser Permanente Northern California were evaluated for their performance characteristics using the hCG5 reagent. Precision, linearity, dilution verification, and patient sample comparisons were performed on each instrument. RESULTS: The assay was linear up to 1350IU/L. Intra-day and inter-day precision ranged from 1.0%-3.3% and 1.8-7.3%, respectively, for the low QC material (mean concentration 4.6IU/L). Percent bias between the previous assay (hCG2) and the hCG5 assay was 3.2 to 22.7% for hCG concentrations <1000IU/L and -2.9 to 30% for concentrations >1000IU/L. On board and manual dilutions agreed within 15% following proper adjustment of the instrument dilution factor. CONCLUSIONS: Achieving Access 2 inter-instrument agreement on specimens needing dilutions (hCG>1350IU/L) requires validation of the on board dilution factor. Laboratories should use QC material above the linear range to monitor instrument dilution accuracy and precision.

Annual Report on the External Quality Assessment Scheme for Clinical Chemistry in Korea (2015)

The Clinical Chemistry Subcommittee of the Korean Association for External Quality Assessment Service conducted external quality assessments in 2015. This included general chemistry and blood gas measurements as part of a scheme of six trials, comprising three samples each. All control materials were included at the same time. The overall response rates were 94.4% for general chemistry and 92.2% for blood gas. The parameters tested included sodium, potassium, chloride, blood urea nitrogen, glucose, calcium, phosphorus, uric acid, creatinine, bilirubin, total protein, albumin, total cholesterol, triglyceride, aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase, lactate dehydrogenase, gamma glutamyl transferase, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol for general chemistry, and pH, partial pressure of carbon dioxide (pCO₂), and partial pressure of oxygen (pO₂) for blood gas assessments. Two types of reports were generated: a method summary, including mean, standard deviation, and coefficient of variation for each test method; and a result summary of each participating laboratory, including mean, standard deviation, number of peer groups, and standard deviation index and variance index scores of each laboratory. The overall quality performance in 2015 was similar to that of previous years, and showed lower interlaboratory variation than that in 2014. The requisite continual improvement in clinical chemistry testing quality can be achieved through participation in similar proficiency testing programs.

Annual Report on the External Quality Assessment Scheme for Clinical Chemistry in Korea (2014)

The Clinical Chemistry subcommittee of The Korean Association of External Quality Assessment Service conducted external quality assessments in 2014. This included general chemistry and blood gas measurements as part of a scheme of six trials, comprising of three samples each. All control materials were sent at the same time. The overall response rates were 93.4% for general chemistry and 90.0% for blood gas. The parameters tested included sodium, potassium, chloride, blood urea nitrogen, glucose, calcium, phosphorus, uric acid, creatinine, bilirubin, total protein, albumin, total cholesterol, triglyceride, AST, ALT, alkaline phosphatase, lactate dehydrogenase, gamma glutamyl transferase, HDL cholesterol, and LDL cholesterol for general chemistry and pH, partial pressure of carbon dioxide, and partial pressure of oxygen for blood gas assessment. Two types of reports were generated, namely, a method summary report including mean, standard deviation, and coefficient of variation, for each test method, as well as a result summary report of each participating laboratory, including mean, standard deviation, number of peer groups, and standard deviation index and variance index scores of each laboratory. The overall quality performance in 2014 was similar to that of previous years and as compared to results from 2013, the inter-laboratory variation was lower. The requisite continual improvement in the quality of clinical chemistry testing can be achieved through participation in similar proficiency testing programs.

Interference of cationic polymeric nanoparticles with clinical chemistry tests--clinical relevance.

The development of medical nanosystems requires knowledge of their behavior in vivo. Clinical chemistry tests are widely used to estimate the systemic toxicity of nanoparticles. In this paper we have explored the impact of small positively charged nanoparticles-poly(amidoamine), phosphorous and carbosilane dendrimers - on biochemical parameters of standardized serum in vitro. All the dendrimers could shift the main biochemical parameters. Thus, in the case of patients having the normal, but 'boundary', values of biochemical parameters, nanoparticle-induced changes can be wrongly interpreted as evidence of some dysfunctions (hepatic, renal, etc.). Moreover, the effects of nanoparticles of metals, carbon nanotubes, quantum dots, fullerenes, dendrimers having been sized up to 4000 nm and the hundreds of reactive groups, can be significantly higher. Thus, preliminary evaluation of any nanomaterial in vitro is required in clinical chemistry tests before its application in vivo to draw the correct conclusions and benefit animals.

Metabonomic analysis reveals efficient ameliorating effects of acupoint stimulations on the menopause-caused alterations in mammalian metabolism.

Acupoint stimulations are effective in ameliorating symptoms of menopause which is an unavoidable ageing consequence for women. To understand the mechanistic aspects of such treatments, we systematically analyzed the effects of acupoint laser-irradiation and catgut-embedding on the ovariectomy-induced rat metabolic changes using NMR and GC-FID/MS methods. Results showed that ovariectomization (OVX) caused comprehensive metabolic changes in lipid peroxidation, glycolysis, TCA cycle, choline and amino acid metabolisms. Both acupoint laser-irradiation and catgut-embedding ameliorated the OVX-caused metabonomic changes more effectively than hormone replacement therapy (HRT) with nilestriol. Such effects of acupoint stimulations were highlighted in alleviating lipid peroxidation, restoring glucose homeostasis and partial reversion of the OVX-altered amino acid metabolism. These findings provided new insights into the menopause effects on mammalian biochemistry and beneficial effects of acupoint stimulations in comparison with HRT, demonstrating metabonomics as a powerful approach for potential applications in disease prognosis and developments of effective therapies.

Annual Report on the External Quality Assessment Scheme in Clinical Chemistry in Korea (2013) / 임상검사와정도관리

The Clinical Chemistry subcommittee of the Korean Association for Quality Assurance for Clinical Laboratory conducted external quality assessments in 2013. This included general chemistry and blood gas measurements as part of a scheme of six trials, comprising of three samples each. All control materials were sent at the same time. The overall response rates were 90.8% for general chemistry and 88.0% for blood gas. The parameters tested included sodium, potassium, chloride, blood urea nitrogen, glucose, calcium, phosphorus, uric acid, creatinine, bilirubin, total protein, albumin, total cholesterol, triglyceride, AST, ALT, alkaline phosphatase, lactate dehydrogenase, and gamma glutamyl transferase for general chemistry and pH, pCO2, and pO2 for blood gas assessment. Two types of reports were generated, namely, method summary reports including mean, standard deviation, and coefficient of variation, according to the test method as well as result summary reports of each participating laboratory, including mean, standard deviation and number of peer groups, and standard deviation index and variance index score of each laboratory. The overall quality performance in 2013 was similar to that of previous years, and as compared to results from 2012, the inter-laboratory variation had decreased. The requisite continual improvement in quality of clinical chemistry testing can be achieved through participation in similar proficiency testing programs.

Annual Report on the External Quality Assessment Scheme in Clinical Chemistry in Korea (2013) / 임상검사와정도관리

The Clinical Chemistry subcommittee of the Korean Association for Quality Assurance for Clinical Laboratory conducted external quality assessments in 2013. This included general chemistry and blood gas measurements as part of a scheme of six trials, comprising of three samples each. All control materials were sent at the same time. The overall response rates were 90.8% for general chemistry and 88.0% for blood gas. The parameters tested included sodium, potassium, chloride, blood urea nitrogen, glucose, calcium, phosphorus, uric acid, creatinine, bilirubin, total protein, albumin, total cholesterol, triglyceride, AST, ALT, alkaline phosphatase, lactate dehydrogenase, and gamma glutamyl transferase for general chemistry and pH, pCO2, and pO2 for blood gas assessment. Two types of reports were generated, namely, method summary reports including mean, standard deviation, and coefficient of variation, according to the test method as well as result summary reports of each participating laboratory, including mean, standard deviation and number of peer groups, and standard deviation index and variance index score of each laboratory. The overall quality performance in 2013 was similar to that of previous years, and as compared to results from 2012, the inter-laboratory variation had decreased. The requisite continual improvement in quality of clinical chemistry testing can be achieved through participation in similar proficiency testing programs.

Analytical measurement and clinical relevance of vitamin D(3) C3-epimer.

With an ever-increasing clinical interest in vitamin D insufficiency, numerous automated immunoassays, protein binding assays, and in-house LC-MS/MS methods are being developed for the quantification of 25-hydroxyvitamin D(3) (25(OH)D(3)). Recently, LC-MS/MS methods have identified an epimeric form of 25(OH)D(3) that has been shown to contribute significantly to 25(OH)D(3) concentration, particularly in infant populations. This review describes the metabolic pathway and physiological functions of 3-epi-vitamin D, compares the capability of various 25(OH)D(3) methods to detect the epimer, and highlights recent publications quantifying 3-epi-25(OH)D(3) in infant, pediatric, and adult populations. In total, this review summarizes the information necessary for clinicians and laboratorians to decide whether or not to report/consider the C3-epimer in the analysis and clinical assessment of vitamin D status.

Analytical Performance of Wako and Sekisui Clinical Chemistry Assays on Hitachi LABOSPECT 008

BACKGROUND: We evaluated the analytical performance of Wako assays for albumin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), complement C3 and C4, calcium, creatine kinase (CK), C-reactive protein (CRP), direct bilirubin (DBIL), iron, gamma-glutamyl transferase (GGT), HDL cholesterol (HDLC), inorganic phosphorus (IP), LDL cholesterol (LDLC), total bilirubin (TBIL), total protein (TP), and uric acid (UA), as well as the performance of Sekisui assays for albumin, BUN, calcium, CRP, HDLC, IP, LDLC, TP, and UA by using Hitachi LABOSPECT 008 (Hitachi High-Tech Co., Japan). METHODS: Liquid Assayed Multiqual Control (Bio-Rad Laboratories, USA) and pooled patients' sera were analyzed for 20 days. Wako linearity material (Wako Pure Chemical Industries, Ltd., Japan) and Sysmex Interference Check A Plus kit (Sysmex Co., Japan) were used to test linearity and interference, respectively. Concentrations of the target analytes were measured using Hitachi LABOSPECT 008 in 100 residual patient specimens and compared to those in Pureauto S series reagent (Sekisui Medical, Japan), which were measured using Hitachi 7600 (Hitachi High-Tech Co., Japan). RESULTS: Total coefficients of variation (CVs) for the tested analytes were 0.91-9.26% in Wako and 1.04-7.46% in Sekisui assays. Linearity was demonstrated up to the highest concentration within the analytical range in all the assays except for Wako albumin and Sekisui TP. Wako and Sekisui albumin, BUN, CRP, HDLC, and LDLC assays, and in Wako C3, C4, calcium, and UA assays showed no interference with the test concentrations used. All the tested assays, except for Wako AST, LDLC, and TP, and Sekisui calcium and TP, demonstrated comparability with comparative method for at least one medical decision level. CONCLUSIONS: Our study results showed that the analytical performances of Wako and Sekisui chemistry assays evaluated using Hitachi LABOSPECT 008 had appropriate analytical performance for clinical use.