Polyphenol analysis in human milk by a rapid, cost-effective, and accurate micromethod: translational development / Análise de polifenóis no leite humano por meio de um micrométodo rápido, econômico e preciso: desenvolvimento translacional

ABSTRACT Objective: To develop a rapid method for analysing polyphenols, which are potentially active antioxidants against neonatal oxidative stress, from small human milk (HM) volumes. Methods: Acid and alkaline extractions were compared using two dyes: Folin-Ciocalteu and Fast Blue BB. Linearity, sensitivity, recovery percentage, polyphenol content, precision, and stability were assessed in 14 HM samples and compared using the Kruskal-Wallis H test (p<0.05). The best technique was applied to 284 HM samples to determine their polyphenolic content and its association with maternal diet by multifactorial linear regression. Results: Acidic extraction successfully recovered the gallic acid reference standard, whereas alkaline extraction overestimated it. Calibration curves for all methods were linear (R2>0.96) up to 500 mg/L. All bicarbonate-based Folin-Ciocalteu methods assayed were stable and repeatable, whereas Fast Blue BB-based variants were not. HM polyphenols (mean=94.68 mg/L) positively correlated to the dietary intake of hydroxycinnamic acids, the most consumed polyphenolic family in this population. Conclusions: A bicarbonate-based Folin-Ciocalteu micromethod allowed the accurate determination of polyphenols in HM, which might be useful for translational research settings and HM banks.

RESUMO Objetivo: Desenvolver um método rápido para analisar polifenóis, que são antioxidantes potencialmente ativos contra o estresse oxidativo neonatal, em pequenos volumes de leite humano (LH). Métodos: Foram comparadas extrações ácidas e alcalinas usando dois corantes: Folin-Ciocalteu e Fast Blue BB. Foram avaliadas variáveis como linearidade, sensibilidade, percentagem de recuperação, teor de polifenóis, precisão e estabilidade em 14 amostras de LH, comparadas usando o teste de Kruskal-Wallis H (p<0,05). A melhor técnica foi aplicada a 284 amostras de LH para determinar seu teor polifenólico e sua associação com a dieta materna por regressão linear multifatorial. Resultados: A extração ácida recuperou com sucesso o padrão de referência do ácido gálico, enquanto a extração alcalina o superestimou. As curvas de calibração para todos os métodos foram lineares (R2>0,96) até os 500 mg/L. Todos os métodos testados baseados em Folin-Ciocalteu com bicarbonato foram estáveis e repetíveis, enquanto as variantes baseadas em Fast Blue BB não. Os polifenóis do HM (média=94,68 mg/L) correlacionaram-se positivamente com a ingestão dietética de ácidos hidroxicinâmicos, a família de polifenóis mais consumida nesta população. Conclusões: Um micrométodo baseado em bicarbonato de Folin-Ciocalteu permitiu a determinação precisa de polifenóis no HM, o que pode ser útil para configurações de pesquisa translacional e bancos de HM.

Evaluation of the GeneXpert MTB/RIF to diagnose tuberculosis in a public health laboratory

ABSTRACT OBJECTIVES To evaluate the performance of geneXpert MTB/Rif versus conventional methods (bacilloscopy and culture) in the diagnosis of tuberculosis in a Central Public Health Laboratory (LACEN, Tocantins), Northern Brazil. METHODS Retrospective study, with information from 1,973 suspected cases of tuberculosis from patients treated from January 2015 to December 2020. RESULTS From the culture (reference standard), the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the geneXpert MTB/Rif were 100%, 97%, 74%, 100%, and 97%, respectively, against 85%, 98%, 80%, 98%, and 97% of bacilloscopy. CONCLUSIONS The geneXpert MTB/Rif performed similarly to culture and better than bacilloscopy. Although positive cases with negative culture should be evaluated with caution, its routine use is important for the early detection of tuberculosis.

Quality management characteristics of mass spectrometry in clinical application / 中华检验医学杂志

Most of the clinical mass spectrometry methods are laboratory-developed tests and lack standardization. Therefore, quality management plays a particularly important role. Compared with conventional methods, mass spectrometry methods have specific quality management points and countermeasures. Firstly, the accuracy of standard and method performance verification should be emphasized in the development stage. Secondly, during actual operation, individual review of data such as retention time, internal standard intensity, and ion ratio of samples is necessary. It is also important to analyze the signal-to-noise ratio and internal variability across the batch of samples as a whole. For long-term project management, retrospective analysis and participation in interlaboratory quality evaluation projects are essential.

Application of mass spectrometry in clinical laboratory in North America / 中华检验医学杂志

Detection of early drug abuse has driven the use of mass spectrometry in clinical laboratories across North America. Mass spectrometry-based assays have been increasingly implemented in various clinical disciplines for their advantages in high analytical sensitivity, specificity and multiplexing capacity. Mass spectrometry is now routinely used for the clinical analysis of small molecule compounds, peptides, proteins, clinical toxicology and microbiology. Although more FDA-approved platforms and reagents need to be commercially available, there is no doubt that mass spectrometry technology has demonstrated rich clinical applications.

Advance in the application of recombinase polymerase amplification-lateral flow strips technology in the diagnosis of pathogenic microorganisms / 中华检验医学杂志

Recombinase polymerase amplification (RPA) is a newly developed isothermal amplification technology with high sensitivity and specificity. The combination of RPA and lateral flow strips (LFS) enables rapid identification of target genes. This technique has been widely used in medicine, food, botany, and other fields. This review generalizes the use of RPA-LFS technology for the diagnosing pathogenic microorganisms, providing a reference for point-of-care diagnosis of pathogenic microorganisms.

Application prospect of nuclear magnetic resonance spectroscopy in clinical laboratory examination / 中华检验医学杂志

Nuclear magnetic resonance spectroscopy (NMRS) is a branch of spectroscopy, which can be used to determine the number, type and relative position of components in the mixture. Due to its high throughput, high sensitivity and high stability, especially its "fingerprint", non-destructive and non-biased detection of metabolites, NMRS has become one of the most commonly used analytical and detection techniques in metabolomics. Based on the research of clinical laboratory application, this review briefly expounds the technical principle of nuclear magnetic resonance spectroscopy, introduces the development and latest research results of nuclear magnetic resonance spectroscopy in biomedical application fields such as blood lipid analysis, tumor detection, prediction of mental and nervous system diseases, infectious diseases, nutrition and health management, and discusses the development prospect of clinical translational medicine.

Correlation of endoscopic evaluation with laboratory indices and clinical disease activity in Crohn disease patients with different intestinal involvement / 中华消化内镜杂志

Objective:To investigate the correlations of endoscopic evaluation results with laboratory indices and clinical disease activity in Crohn disease (CD) patients with different intestinal involvement.Methods:Data of 147 patients diagnosed as having CD who visited the Department of Gastroenterology, Zhongnan Hospital of Wuhan University from July 1, 2017 to June 30, 2022 were collected retrospectively. According to the involvement of intestinal segment, patients were divided into three groups: the group with isolated small intestinal involvement ( n=55), the group with both small intestinal and large intestinal involvement ( n=48), and the group with isolated large intestinal involvement ( n=44). Correlations of endoscopic evaluation (based on CDEIS) with laboratory indices and clinical disease activity (based on Harvey-Bradshaw index) were analyzed. Results:C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) could be used for the prediction of endoscopic disease activity. The areas under curve (AUC) of receiver operator characteristic (ROC) were 0.677 (0.506-0.849) and 0.744 (0.597-0.890), respectively. In terms of determing clinical disease activity, clinical Harvey-Bradshaw index was consistent with endoscopic CDEIS score in 65.3% (96/147) patients, showing a low positive correlation ( r=0.260, P<0.05). In subgroup analysis for patients with isolated small intestinal involvement, CRP showed no predictive value for clinical disease activity [AUC (95% CI): 0.617 (0.461-0.773), P=0.148], while for endoscopic activity neither CRP nor ESR showed predictive value [AUC (95% CI): 0.537 (0.146-0.929), P=0.829; AUC (95% CI): 0.571 (0.153-0.990), P=0.680]. Furthermore, for patients with isolated small intestinal involvement and both small intestinal and large intestinal involvement, no correlation was found between clinical Harvey-Bradshaw index and endoscopic CDEIS score ( r=0.222, P=0.092; r=0.142, P=0.322). Conclusion:For CD patients with small intestinal involvement, especially isolated small intestinal involvement, laboratory indices and clinical disease activity cannot accurately reflect endoscopic disease activity. Great importance should be attached to evaluation of the extent and activity of intestinal lesions by endoscopy, especially enteroscopy.

Características e diagnóstico laboratorial das infecções causadas pelo hantavírus: revisão integrativa / Characteristics and laboratory diagnosis of infections caused by hantavirus: integrative review

A hantavirose é uma zoonose de distribuição mundial que utiliza como vetores roedores, musaranhos, toupeiras e morcegos. Os sintomas da infecção pelo hantavírus assemelham-se aos de diversas doenças, por isso o diagnóstico laboratorial é crucial para o tratamento precoce. Objetivo: Realizar uma revisão da literatura sobre as características e diagnóstico laboratorial da hantavirose. Métodos: Trata-se de uma revisão integrativa da literatura com base no modelo PRISMA, com seleção de estudos nas bases de dados Portal de Periódicos da Capes, PubMed/Medline, SciELO, ScienceDirect e Biblioteca Virtual em Saúde (BVS). Foram empregados os descritores: hantavírus, diagnóstico laboratorial, exames e zoonose, em português e inglês, no período de 2015 a 2022, sendo selecionados 19 artigos científicos em atendimento aos critérios de inclusão. Resultados e Discussão: Diversas técnicas diagnósticas podem ser empregadas em casos de hantavirose, sendo a biologia molecular a mais empregada, conjuntamente com a imunologia. Há outros recursos utilizados para monitoramento e evolução da doença, como a bioquímica, a hematologia e a imagenologia. Para a ocorrência de hantavirose é necessário um ambiente propício, clima específico e contato com hospedeiro suscetível, podendo evoluir para quadros assintomáticos ou sintomáticos com complicações graves. Conclusão: O diagnóstico dessa doença é desafiador e requer investigação detalhada que inclua a sintomatologia do paciente, o histórico de exposição a animais reservatórios e os resultados de exames laboratoriais. Como desfechos negativos da hantavirose incluem-se a febre hemorrágica com síndrome renal, a síndrome pulmonar por hantavírus e o óbito

Hantavirus is a worldwide distributed zoonosis that uses rodents, shrews, moles and bats as vectors. The symptoms of hantavirus infection resemble those of many diseases, so laboratory diagnosis is crucial for early treatment. Objective: The present study aimed to conduct a literature review on the characteristics and laboratory diagnosis of hantavirus. Methods: This is an integrative literature review based on the PRISMA model, with a selection of studies in the Capes Portal de Periódicos, PubMed/Medline, SciELO, ScienceDirect and Virtual Health Library databases, using the descriptors: hantavirus, laboratory diagnosis, exams, and zoonosis, in portuguese and english, from 2015 to 2022, and nineteen scientific articles that met the inclusion criteria were selected. Results and Discussion: Several techniques can be used in cases of hantavirus, with molecular biology being the most evidenced along with immunology. There are other parameters that are used for monitoring and evolution of the disease, such as biochemistry, hematology, and imaging. For the hantavirus disease, an adequate environment, specific climate and contact with a susceptible host are necessary, which may lead to asymptomatic conditions or symptoms with more serious complications. Conclusion: The diagnosis of this disease is challenging and requires detailed investigation that includes the patient's symptoms, the history of exposure to reservoir animals and the results of laboratory tests. Negative outcomes of hantavirus infection include hemorrhagic fever with renal syndrome, hantavirus pulmonary syndrome, and death

Performance and reference intervals of thrombin generation test: results from the Brazilian longitudinal study of adult health (ELSA-Brasil). A cross-sectional study

ABSTRACT BACKGROUND: The thrombin generation test (TGT) has shown promise for investigation of hemorrhagic and thrombotic diseases. However, despite its potential, it still needs standardization. Moreover, few studies have established reference values for TGT parameters. In Brazil, these values have not yet been established. OBJECTIVE: To determine TGT performance and reference intervals for TGT parameters in healthy individuals. DESIGN AND SETTING: Cross-sectional study conducted among participants in the Brazilian Longitudinal Study of Adult Health (Estudo Longitudinal de Saúde do Adulto, ELSA-Brasil). METHODS: The reference sample consisted of 620 healthy individuals. The calibrated automated thrombogram (CAT) method, under low and high tissue factor (TF) conditions, was used to assess thrombin generation. Test performance was analyzed using intra and interassay coefficients of variation (CV) and reference intervals were calculated using the nonparametric method proposed by the International Federation of Clinical Chemistry and the Clinical and Laboratory Standards Institute. RESULTS: The intraassay CV ranged from 1.4% to 2.2% and the interassay CV, 6.8% to 14.7%. The reference intervals for TGT parameters under low and high TF conditions were, respectively: lagtime: 3.0-10.3 and 1.4-3.7 min; endogenous thrombin potential (ETP): 1134.6-2517.9 and 1413.6-2658.0 nM.min; normalized ETP: 0.6-1.3 and 0.7-1.4; peak: 103.2-397.7 and 256.4-479.0 nM; normalized peak: 0.3-1.3 and 0.7-1.2; and time-to-peak: 5.6-16.0 and 3.4-6.7 min. These parameters were categorized relative to sex. Conclusion: TGT performance was adequate and the proposed reference intervals were similar to those of other studies. Our findings may be useful for consolidating the TGT, through contributing to its standardization and validation.

Does ascitic fluid filtration improve the microbiological diagnosis of spontaneous bacterial peritonitis? An experimental laboratory study / A filtração do líquido ascítico melhora o diagnóstico microbiológico da peritonite bacteriana espontânea? Um estudo experimental laboratorial

Background: Spontaneous Bacterial Peritonitis (SBP) is a serious and frequent complication among cirrhotic patients with ascites and can be diagnosed by cytological analysis of the ascitic fluid. The microbiological culture of ascitic fluid, however, is positive in less than 40% of SBP cases, which often results in inappropriate antimicrobial therapy. Empirical therapy may be suboptimal, increasing patient's risk of aggravation, or overestimated, unnecessarily boosting bacterial resistance. Objective: This experimental laboratory study aimed to standardize and verify the technical feasibility of ascitic fluid vacuum filtration, as a way to optimize the etiological diagnosis of SBP, compared to the automated method. Method: The method evaluated and standardized in this study was ascitic fluid vacuum filtration. Its principle is the concentration of bacteria on a filter membrane. Results: This study included 36 cirrhotic patients treated at a public university hospital between 11.13.2017 and 06.30.2019. Among them, 47.2% (17/36) presented cytology test results compatible with SBP. For these patients, culture sensitivity using the automated method was 35.3% (6/17), against 11.8% (2/17) with the vacuum filtration method. Conclusion: In conclusion, vacuum filtration does not improve the microbiological diagnosis of SBP in this population compared to the automated method (AU)

Contexto: A Peritonite Bacteriana Espontânea (PBE) é uma complicação grave e frequente entre pacientes cirróticos com ascite, diagnosticada por meio da análise citológica do líquido ascítico. A cultura microbiológica do líquido ascítico, por sua vez, é positiva em menos de 40% dos casos de PBE, o que resulta frequentemente na instituição de terapia antimicrobiana inapropriada. A terapia empírica pode ser subótima, aumentando o risco de agravamento do paciente, ou superestimada, impulsionando desnecessariamente a resistência bacteriana. Objetivo: Estudo experimental laboratorial, propôs padronizar e verificar a viabilidade técnica da filtração a vácuo do líquido ascítico, como forma de otimizar o diagnóstico etiológico na PBE, comparativamente ao sistema automatizado de culturas de sangue. Método: O método avaliado e padronizado neste estudo foi a da filtragem a vácuo do líquido ascítico. Esse tem como princípio a concentração da bactéria em uma membrana filtrante. Resultados: Nesse estudo, foram incluídos 36 pacientes cirróticos atendidos em um hospital público universitário, entre 13.11.2017 e 30.06.2019. Entre eles, 47,2% (17/36) apresentaram citologia compatível com PBE. Nesses, a sensibilidade da cultura pelo método semi-automatizado foi de 35,3% (6/17) e da cultura pelo método da filtragem a vácuo foi de 11,8% (2/17). Conclusão: Em conclusão, a filtragem a vácuo não melhora o diagnóstico microbiológico da PBE em relação ao método automatizado (AU)

Utilidad diagnóstica de pruebas rápidas para detectar anticuerpos IgG/IgM anti COVID-19

RESUMEN Fundamento Las pruebas rápidas para el diagnóstico del SARS-CoV-2 constituyen opciones atractivas por su simplicidad, rapidez y rentabilidad; pero poseen diferentes grados de sensibilidad y especificad diagnóstica. Objetivo evaluar el desempeño analítico de pruebas rápidas para detectar anticuerpos IgG/IgM anti COVID-19. Métodos estudio descriptivo, realizado con los pacientes ingresados en el Centro Especializado Ambulatorio Héroes de Playa Girón, de Cienfuegos, con diagnóstico presuntivo, probable o confirmado de COVID-19 durante dos períodos de tiempo. A todos se les realizó la prueba rápida para detectar anticuerpos anti COVID-19, además de un ensayo confirmatorio por biología molecular. Se calcularon la sensibilidad y especificidad diagnósticas, los valores predictivos y la eficiencia de la prueba rápida dentro de un intervalo de confianza del 95 %. Resultados se obtuvo una excelente especificidad (98,75 %) y regular sensibilidad (54,54 %), así como buenos valores predictivos y eficiencia diagnóstica global. Conclusión Las pruebas rápidas anti COVID-19 evaluadas mostraron un desempeño diagnóstico adecuado. Resultan una alternativa diagnóstica asequible y valiosa para evaluar exposición previa al SARS-CoV-2. Su uso clínico está restringido para ciertas situaciones médicas; sin embargo, constituyen una herramienta epidemiológica útil.

ABSTRACT Background Rapid tests for the diagnosis of SARS-CoV-2 are attractive options due to their simplicity, speed and cost-effectiveness; but they have different degrees of sensitivity and diagnostic specificity. Objective to evaluate the analytical performance of rapid tests to detect IgG/IgM antibodies against COVID-19. Methods descriptive study, carried out with patients admitted to the Héroes de Playa Girón Specialized Ambulatory Center, in Cienfuegos, with a presumptive, probable or confirmed diagnosis of COVID-19 during two periods of time. All of them underwent a rapid test to detect anti-COVID-19 antibodies, in addition to a confirmatory molecular biology test. Diagnostic sensitivity and specificity, predictive values, and rapid test efficiency were calculated within a 95% confidence interval. Results excellent specificity (98.75%) and regular sensitivity (54.54%) were obtained, as well as good predictive values and overall diagnostic efficiency. Conclusion The rapid anti-COVID-19 tests evaluated showed adequate diagnostic performance. They constitute an affordable and valuable diagnostic alternative to assess previous exposure to SARS-CoV-2. Its clinical use is restricted to certain medical situations; however, they constitute a useful epidemiological tool.

Does ascitic fluid filtration improve the microbiological diagnosis of spontaneous bacterial peritonitis? An experimental laboratory study / A filtração do líquido ascítico melhora o diagnóstico microbiológico da peritonite bacteriana espontânea? Um estudo experimental laboratoria

ABSTRAC: Background: Spontaneous Bacterial Peritonitis (SBP) is a serious and frequent complication among cirrhotic patients with ascites and can be diagnosed by cytological analysis of the ascitic fluid. The microbiological culture of ascitic fluid, however, is positive in less than 40% of SBP cases, which often results in inappropriate antimicrobial therapy. Empirical therapy may be suboptimal, increasing patient's risk of aggravation, or overestimated, unnecessarily boosting bacterial resistance. Objective: This experimental laboratory study aimed to standardize and verify the technical feasibility of ascitic fluid vacuum filtration, as a way to optimize the etiological diagnosis of SBP, compared to the automated method. Method: The method evaluated and standardized in this study was ascitic fluid vacuum filtration. Its principle is the concentration of bacteria on a filter membrane. Results: This study included 36 cirrhotic patients treated at a public university hospital between 11.13.2017 and 06.30.2019. Among them, 47.2% (17/36) presented cytology test results compatible with SBP. For these patients, culture sensitivity using the automated method was 35.3% (6/17), against 11.8% (2/17) with the vacuum filtration method. Conclusion: In conclusion, vacuum filtration does not improve the microbiological diagnosis of SBP in this population compared to the automated method. (AU)

RESUMO:Contexto: A Peritonite Bacteriana Espontânea (PBE) é uma complicação grave e frequente entre pacientes cirróticos com ascite, diagnosticada por meio da análise citológica do líquido ascítico. A cultura microbiológica do líquido ascítico, por sua vez, é positiva em menos de 40% dos casos de PBE, o que resulta frequentemente na instituição de terapia antimicrobiana inapropriada. A terapia empírica pode ser subótima, aumentando o risco de agravamento do paciente, ou superestimada, impulsionando desnecessariamente a resistência bacteriana. Objetivo: Estudo experimental laboratorial, propôs padronizar e verificar a viabilidade técnica da filtração a vácuo do líquido ascítico, como forma de otimizar o diagnóstico etiológico na PBE, comparativamente ao sistema automatizado de culturas de sangue. Método: O método avaliado e padronizado neste estudo foi a da filtragem a vácuo do líquido ascítico. Esse tem como princípio a concentração da bactéria em uma membrana filtrante. Resultados: Nesse estudo, foram incluídos 36 pacientes cirróticos atendidos em um hospital público universitário, entre 13.11.2017 e 30.06.2019. Entre eles, 47,2% (17/36) apresentaram citologia compatível com PBE. Nesses, a sensibilidade da cultura pelo método semi-automatizado foi de 35,3% (6/17) e da cultura pelo método da filtragem a vácuo foi de 11,8% (2/17). Conclusão: Em conclusão, a filtragem a vácuo não melhora o diagnóstico microbiológico da PBE em relação ao método automatizado. (AU)

Lodderomyces elongisporus causing catheter-related bloodstream infection and its biological characteristics / 中华检验医学杂志

In order to improve the laboratory identification ability of Lodderomyces elongisporus, we analyzed the main biological characteristics of Lodderomyces elongisporus isolated from peripheral venous blood and catheter blood of a brain stem infarction patient with a body temperature of 38.4 ℃, observed the colony color of the strain on CHROMagar Candida medium and the ascospores on Mcclary agar, identified the isolates with Vitek 2 compact, MALDI-TOF MS and sequence analysis, and tested the MICs with borth microdilution. The MICs of antifungal agents against Lodderomyces elongisporus are well below the normal values of these drugs. The central venous catheter was removed and antifungal drugs were used until two weeks after the last positive blood culture. During the medication perios, the blood culture was repeatedly negative, the patient had no fever and the infection index decreased to normal, which can be used for clinical reference.

Influence of three different nucleic acid extraction methods on 2019-nCoV / 中华检验医学杂志

Objective:To study the difference in the extraction efficiency of the novel coronavirus (2019-nCoV) nucleic acid by using magnetic beads method, centrifugal column method and one-step method.Methods:On March 5, 2021, 10 throat swabs were collected from the staff working in the nucleic acid sampling room in Department of Clinical Laboratory, Affiliated Taikang Xianlin Drum Tower Hospital, Medical School of Nanjing University. The positive quality control samples were mixed into the swabs and used as mock positive samples. The RNA was extracted from simulated positive samples and their diluted samples by using magnetic beads method, centrifugation column method and one-step method. The purity ( A260/ A280 ratio) and concentration of the nucleic acid obtained were measured by micro-uv photometry, and fluorescence quantitative PCR was performed to compare the CT value and extraction efficiency. The three methods were used to extract the simulated weak positive specimens and to compare the difference of CT values after amplification. The measurement data that followed normal distribution were expressed by xˉ±s, the t test was used for comparing in the same group, and single factor analysis of variance was used for comparing among multiple groups. A P value smaller than 0.05 indicated a significant difference. Results:2019-nCoV nucleic acid extracted by magnetic bead method, centrifugal column method and one-step method could amplify positive results. There was no significant difference between the CT value of RNA amplification extracted by magnetic bead method and one-step method ( t=? 0.995 , P=0.376). The CT values of orf1ab gene amplified by centrifugal column method, magnetic bead method and one-step method were 29.28±0.06, 30.82±0.14 and 29.79±0.01 respectively ( F=11.196 , P=0.041). The CT values of E gene were 28.52±0.40, 27.33±0.78 and 27.38±0.13 respectively ( F=3.407, P=0.169). The CT values of N gene were 28.61±1.02, 27.24±0.20 and 27.25±0.47, respectively ( F=2.880 , P=0.020). The CT values of human genes extracted by centrifugal column method, magnetic bead method and one-step method were 19.68±0.36, 20.14±0.06 and 20.58±0.49 respectively, which was statistically significant ( F=4.904, P=0.048). The CT value of amplified human gene was affected by the dilution of human samples twice. The CT value of undiluted samples was smaller than that of diluted samples twice, with a difference of 2.95±0.22, which was statistically significant ( t=?3.025, P=0.039). The extraction time of one-step method, magnetic bead method and centrifugal column method were (15.00±1.50), (20.00±1.50) and (40.00±5.5) min respectively, and the difference was statistically significant ( F=688 , P=0.027). Conclusions:Magnetic bead method, centrifugal column method and one-step method can be used to extract 2019-nCoV nucleic acid, for the centrifugal column method has a higher extraction efficiency than the magnetic bead method and the one-step method. The one-step method is the fastest, followed by the magnetic bead method and the centrifugal column method. A large number of clinical samples can be processed using the magnetic bead method and one-step method. One-step rapid nucleic acid test can also be performed on samples from emergency and fever clinics. It is not recommended to dilute specimens for testing. In order to improve the detection rate, extracting RNA from highly suspected samples with negative initial nucleic acid test by centrifugal column method is suggested.

Value of plasma Epstein-Barr virus DNA detection in the screening of nasopharyngeal carcinoma and its clinical application in non-high-risk areas / 中华检验医学杂志

Objective:To investigate the value of plasma Epstein-Barr virus (EBV) DNA detection in the screening of nasopharyngeal carcinoma (NPC) and its clinical application in non-high-risk areas.Methods:Plasma EBV DNA results in 1 153 newly diagnosed nasopharyngeal carcinoma patients who were treated in Sichuan Cancer Hospital from 2015 to 2020 and 244 healthy control cases with matched sex and age were retrospectively analyzed. EBV DNA were detected by quantitative real-time PCR. Positive rate of EBV DNA was determined by the cutoff value of 400 (≥400 copies/ml as positive) and optimization threshold method (presence of S amplification curve as positive). Further analyses were conducted to compare EBV DNA load in different clinical stage, TNM stage and regions distribution characteristics. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value of the cutoff value of 400 and optimization threshold method for NPC.Results:Compared with healthy controls, EBV DNA increased significantly in newly diagnosed NPC patients ( P<0.001). Both evaluation methods revealed that the EBV DNA positive percentage increased with TNM and clinical stage ( P<0.001). With 400 copies/ml as cutoff value, the diagnostic sensitivity and specificity were 40.85% and 100%, respectively. The area under the curve was 0.704 (95% CI 0.676-0.733, P<0.001). Evaluated by the optimization threshold method, the sensitivity and specificity could improve to 82.0% and 99.2%, respectively, and the area under the curve reached 0.910 (95% CI 0.894-0.924, P<0.001). Conclusions:In the low prevalence area of nasopharyngeal carcinoma, the sensitivity for diagnosis of nasopharyngeal carcinoma is only 40.9% by the 400 copies/ml cutoff value method. The optimization threshold method is a better choice to improve the diagnostic sensitivity without lowering the diagnostic specificity.

Current status on the laboratory determination of advanced glycation end products / 中华检验医学杂志

The concentration and accumulation rate of advanced glycation end products (AGEs) in the body are highly correlated with glycometabolic disorders. Therefore, the clinical detection of AGEs is of great value for the early diagnosis and prognostic evaluation of these diseases. However, due to the complexity of its structure, the diversity of glycosylation sites, and the limitations of existing detection methods, there is still a lack of widely available detection methods in clinical practice. Starting from the structure and classification of AGEs and the value of clinical testing, this article summarizes current status of various laboratory detection methods of AGEs, and the deficiencies and challenges of these testing methods, future directions are further prospected.

Application of digital PCR technology in the precise molecular diagnosis: opportunities and challenges / 中华检验医学杂志

Digital polymerase chain reaction (dPCR) is an absolute quantitative technique that has been rapidly developed in recent years. This technique assigns the reaction system containing DNA template to a large number of independent reaction units for PCR, and calculates the DNA copy number according to the Poisson distribution and statistical positive signals. In contrast to conventional qPCR, dPCR does not depend on amplification curves, is not affected by amplification efficiency, thus has high accuracy and repeatability, and can achieve the absolute quantification. This article reviews the development history of dPCR and its application in molecular diagnosis, tumor liquid biopsy and prenatal diagnosis of infectious diseases, and looks forward to the application prospect of this technology.

Progress of human epidermal growth factor receptor 2 expression in breast cancer and its detection methods / 肿瘤研究与临床

Positively expressed human epidermal growth factor receptor 2 (HER2) occurs in 20%-30% of breast cancer patients, and the prognosis of them is generally poor. Fortunately, the application of HER2-targeted drugs has bright hopes for these patients. The comprehensive detection strategy of immunohistochemistry (IHC) for detecting HER2 protein overexpression combined with fluorescence in situ hybridization (FISH) for detecting HER2 gene amplification is widely used in HER2 breast cancer. However, this strategy applied in some patients with specially expressed HER2 in clinic is still controversial. RNAscope technique can make in situ analysis of HER2 mRNA expression and can be used as a complementary method. This paper summarizes the detection methods of HER2 on protein, DNA and RNA levels in order to provide references for accurate HER2 detection methods in breast cancer.

Promoting the clinical research and standardization of neuroimmunological laboratory tests / 中华检验医学杂志

Neuroimmune diseases are a group of diseases in which the interaction between the nervous system and the immune system leads to structural damage and/or dysfunction in the nervous system. Timely diagnosis and appropriate immunological intervention can lead to a better cure for the patients and improving prognosis. The emerging neuro-immunological biomarkers including autoantibody profiles, lymphocyte subsets, cytokines and special proteins are important indicators for clinical diagnosis and monitoring of immune status. Currently, however, there are many difficulties in standardization of laboratory testing, disease diagnosis criteria, result interpretation, and mutual recognition among the laboratories, etc. There is an urgent to evaluate the clinical significance of these laboratory indicators correctly, to establish standardization of procedures (SOP) of testing, and to conduct quality control through inter-laboratory monitoring for guiding treatment strategies, monitoring efficacy, and evaluating prognosis. In this paper, neuroimmune tests are suggested to be divided into two categories: conventional panel and research panel. The clinical significance, testing methods and technology of the two categories were discussed. The aim is to evoke mutual communication and cooperation between clinical departments and diagnostic laboratories, to promote the clinical research and standardization of laboratory testing, and to bring more benefits to patients with neuroimmunological diseases.

Current application of chimeric antigen receptor T cell immunotherapy and related laboratory examinations / 中华检验医学杂志

Chimeric antigen receptor (CAR)-T cell immunotherapy is a revolutionary advancement in cancer treatment, and is highly effective in treatment of B cell leukemia, lymphoma, and multiple myeloma. However, it has some deficiencies such as antigen escape, antigen heterogeneity, toxic and side effects, which also pose challenges for therapy of other hematological malignancies and solid tumors. Comprehensive and continuous laboratory monitoring before and after CAR-T cell immunotherapy plays an important role in early warning of toxic and side effects, as well as theraputic evaluation. In the future, new breakthroughs for tumor therapy. Should be focused on improving CAR-T cells design, enhancing their anti-tumor activity, and optimizing therapeutic regimen.