Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.262
Filtrar
1.
Diagn Microbiol Infect Dis ; 99(1): 115206, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33045499

RESUMO

The diagnosis of coronavirus disease-19 (COVID-19) relies on the detection of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) RNA by real-time reverse-transcription polymerase chain reaction in respiratory samples. Rapid increase in the COVID-19 cases across the world requires fast and efficient testing as testing capacity is a bottleneck in diagnosis. In this context, pooling strategy can be opted for rapid testing in a cost-effective manner. In this study, the authors have optimized and compared the effect of pooling (5 and 10 samples) before and after nucleic acid extraction. It was concluded that there was no significant difference in the SARS CoV-2 RNA detection in the pools prepared at sample or RNA level. Even after pooling, 10-fold dilution was detectable with 3-cycle threshold value change in both type of pools when compared with individual samples. Hence, sample pool size of 10 can be used in low-prevalent areas, and testing capacity can be substantially increased.


Assuntos
/métodos , /isolamento & purificação , Manejo de Espécimes/métodos , /normas , Genes Virais/genética , Humanos , Índia/epidemiologia , Nasofaringe/virologia , Faringe/virologia , RNA Viral/genética , RNA Viral/isolamento & purificação , Sensibilidade e Especificidade , Manejo de Espécimes/normas , Centros de Atenção Terciária
2.
Clin Chim Acta ; 512: 58-62, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33285119

RESUMO

OBJECTIVE: It is unclear if implementation of biosafety action plans in response to the COVID-19 pandemic has affected laboratory quality metrics. METHODS: This retrospective study used quality data, including turnaround time (TAT) and number/type of unacceptable specimens from a stat laboratory supporting an outpatient medical clinic serving predominantly elderly cancer patients. Four months of data from the height of the COVID-19 pandemic (March-June 2020) were compared to the same months in 2019. RESULTS: March-May 2020 test volumes were decreased compared to 2019. June 2020 test volume was slightly increased compared to 2019. TATs in 2020 were similar/ slightly improved compared to the same months in 2019, due to shortened collect to receive and receive to verify TATs. The number and types of unacceptable specimens were similar in 2020 and 2019. CONCLUSIONS: Despite the challenges to the system caused by the pandemic, laboratory quality metrics were maintained.


Assuntos
Laboratórios/estatística & dados numéricos , Idoso , Contenção de Riscos Biológicos/normas , Humanos , Laboratórios/normas , Neoplasias , Pandemias , Estudos Retrospectivos , Manejo de Espécimes/normas , Manejo de Espécimes/estatística & dados numéricos , Fatores de Tempo
3.
PLoS One ; 15(12): e0242404, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33259520

RESUMO

BACKGROUND: The All Our Families (AOF) cohort study is a longitudinal population-based study which collected biological samples from 1948 pregnant women between May 2008 and December 2010. As the quality of samples can decline over time, the objective of the current study was to assess the association between storage time and RNA (ribonucleic acid) yield and purity, and confirm the quality of these samples after 7-10 years in long-term storage. METHODS: Maternal whole blood samples were previously collected by trained phlebotomists and stored in four separate PAXgene Blood RNA Tubes (PreAnalytiX) between 2008 and 2011. RNA was isolated in 2011 and 2018 using PAXgene Blood RNA Kits (PreAnalytiX) as per the manufacturer's instruction. RNA purity (260/280), as well as RNA yield, were measured using a Nanodrop. The RNA integrity number (RIN) was also assessed from 5-25 and 111-130 months of storage using RNA 6000 Nano Kit and Agilent 2100 BioAnalyzer. Descriptive statistics, paired t-test, and response feature analysis using linear regression were used to assess the association between various predictor variables and quality of the RNA isolated. RESULTS: Overall, RNA purity and yield of the samples did not decline over time. RNA purity of samples isolated in 2011 (2.08, 95% CI: 2.08-2.09) were statistically lower (p<0.000) than samples isolated in 2018 (2.101, 95% CI: 2.097, 2.104), and there was no statistical difference between the 2011 (13.08 µg /tube, 95% CI: 12.27-13.89) and 2018 (12.64 µg /tube, 95% CI: 11.83-13.46) RNA yield (p = 0.2964). For every month of storage, the change in RNA purity is -0.01(260/280), and the change in RNA yield between 2011 and 2018 is -0.90 µ g / tube. The mean RIN was 8.49 (95% CI:8.44-8.54), and it ranged from 7.2 to 9.5. The rate of change in expected RIN per month of storage is 0.003 (95% CI 0.002-0.004), so while statistically significant, these results are not relevant. CONCLUSIONS: RNA quality does not decrease over time, and the methods used to collect and store samples, within a population-based study are robust to inherent operational factors which may degrade sample quality over time.


Assuntos
Coleta de Amostras Sanguíneas/normas , Estabilidade de RNA/genética , RNA/sangue , Manejo de Espécimes/normas , Testes Diagnósticos de Rotina , Feminino , Humanos , Gravidez , Controle de Qualidade , RNA/genética
4.
Ann Biol Clin (Paris) ; 78(6): 609-616, 2020 Dec 01.
Artigo em Francês | MEDLINE | ID: mdl-33361015

RESUMO

Confronted with the COVID-19 crisis, healthcare professionals have had to tackle an epidemic crisis of a huge magnitude for which they were not prepared. Medical laboratories have been on the front line, from collecting samples to performing the analysis required to diagnose this new pathology. Responding to the needs and to the urgency of the situation, the authorities relied on the network of private laboratories. In France, private laboratory medicine represents 70% of overall activity, and with a network of more than 4,000 local laboratories, private laboratory medicine has been the cornerstone of the « screen-trace-isolate ¼ strategy. This article gives feedback from private laboratory medicine professionals, directly involved in the reorganization carried out at the pre-analytical, analytical and post-analytical stages, during the crisis from March to October 2020.


Assuntos
/epidemiologia , Serviços de Laboratório Clínico/organização & administração , Pandemias , Setor Privado/organização & administração , Manejo de Espécimes/normas , /diagnóstico , Serviços de Laboratório Clínico/normas , Técnicas de Laboratório Clínico/instrumentação , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/prevenção & controle , Segurança de Equipamentos/métodos , Segurança de Equipamentos/normas , França/epidemiologia , Unidades Hospitalares/organização & administração , Humanos , Colaboração Intersetorial , Corpo Clínico/organização & administração , Corpo Clínico/normas , Segurança do Paciente/normas , Fase Pré-Analítica/métodos , Fase Pré-Analítica/normas , Setor Privado/normas , Manejo de Espécimes/métodos
5.
J Insect Sci ; 20(6)2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33135760

RESUMO

Tick-borne diseases are emerging globally, necessitating increased research and coordination of tick surveillance practices. The most widely used technique for active collection of host-seeking, human-biting tick vectors is 'tick dragging', by which a cloth is dragged across the top of the vegetation or forest floor and regularly checked for the presence of ticks. Use of variable dragging protocols limits the ability of researchers to combine data sets for comparative analyses or determine patterns and trends across different spatial and temporal scales. Standardization of tick drag collection and reporting methodology will greatly benefit the field of tick-pathogen studies. Based on the recommendations of the Center for Disease Control and Prevention and other ecological considerations, we propose that tick dragging should be conducted to sample at least 750 m2 along linear transects when habitat allows in a manner that reduces bias in the sampled area, and report density of each tick species and life stage separately. A protocol for constructing a standard drag cloth, establishing linear transects, and drag sampling is presented, along with a downloadable datasheet that can be modified to suit the needs of different projects. Efforts to align tick surveillance according to these standard best practices will help generate robust data on tick population biology.


Assuntos
Entomologia/métodos , Ixodidae , Parasitologia/métodos , Manejo de Espécimes/métodos , Animais , Entomologia/normas , Ixodidae/crescimento & desenvolvimento , Larva , Parasitologia/normas , Manejo de Espécimes/normas
6.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 49(5): 565-573, 2020 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-33210481

RESUMO

OBJECTIVE: To explore effects of different delivery and storage conditions on concentrations of amino acids and carnitines in neonatal dried blood spots (DBS), so as to provide evidence for improving accurate and reliable detection by tandem mass spectrometry. METHODS: A total of 1 254 616 newborn DBS samples in Newborn Screening Center of Zhejiang Province were delivered and stored at room temperature (group A, n=338 467), delivered by cold-chain logistics system and stored at low temperature (group B, n=480 021), or delivered by cold-chain logistics system and stored at low temperature and low humidity (group C, n= 436 128), respectively. The concentrations of amino acids and carnitines in DBS were detected by tandem mass spectrometry. Data analysis was performed by SPSS 24.0 to explore the influence of temperature and humidity on the concentrations of amino acids and carnitines. RESULTS: The concentrations of amino acids and carnitines in the three groups were skewed, and the differences in amino acid and carnitine concentrations among groups were statistically significant (all P<0.01). The median concentration of tyrosine was lower in group A than those in group B and group C by 18%and 16%respectively, while there was no significant difference between the last two groups. The median concentrations of methionine were lower in group A and group B than that in group C by 15%and 11%, respectively. The median concentrations of arginine were lower in group A and group B than that in group C by 12%and 25%, respectively. The median concentration of free carnitine (C0) was higher in group A than that in group C by 12%, while there was no significant difference between group A and group B. The median concentrations of acetylcarnitine (C2), propionyl carnitine (C3), C3DC+C4OH, C5DC+C6OH and hexadecanoyl carnitine (C16) were lower in group A than those in group B and group C by 21%-64%. The concentrations of other amino acids and acylcarnitines differed little among three groups. The monthly median coefficients of variation of other amino acids and carnitines in group A were higher than those in group B and group C except for citrulline, C4DC+C5OH and isovalerylcarnitine (C5). CONCLUSIONS: Cold-chain logistics system and storage in low temperature and low humidity can effectively reduce degradation of some amino acids and carnitines in DBS, improve the accuracy and reliability of detection, and thus ensures the quality of screening for neonatal metabolic diseases.


Assuntos
Aminoácidos , Teste em Amostras de Sangue Seco , Triagem Neonatal , Aminoácidos/análise , Carnitina/análise , Teste em Amostras de Sangue Seco/métodos , Teste em Amostras de Sangue Seco/normas , Humanos , Umidade , Recém-Nascido , Reprodutibilidade dos Testes , Manejo de Espécimes/normas , Espectrometria de Massas em Tandem , Temperatura , Fatores de Tempo
9.
Clin Chim Acta ; 511: 177-180, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33068630

RESUMO

To clarify the effect of different respiratory sample types on SARS-CoV-2 detection, we collected throat swabs, nasal swabs and hock-a-loogie saliva or sputum, and compared their detection rates and viral loads. The detection rates of sputum (95.65%, 22/23) and hock-a-loogie saliva (88.09%, 37/42) were significantly higher than those in throat swabs (41.54%, 27/65) and nasal swabs (72.31%, 47/65) (P < 0.001). The Ct Values of sputum, hock-a-loogie saliva and nasal swabs were significantly higher than that in throat swabs, whereas no significant difference was observed between sputum and saliva samples. Hock-a-loogie saliva are reliable sample types that can be used to detect SARS-CoV-2, and worthy of clinical promotion.


Assuntos
/diagnóstico , Reação em Cadeia da Polimerase/normas , Saliva/virologia , Manejo de Espécimes/normas , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nasofaringe/virologia , Reação em Cadeia da Polimerase/métodos , Estudos Prospectivos , Manejo de Espécimes/métodos , Escarro/virologia , Carga Viral/métodos , Carga Viral/normas
10.
J Chromatogr A ; 1633: 461615, 2020 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-33099196

RESUMO

This review focuses on the existing analytical procedures for the determination of new psychoactive substances (NPS) in biological fluids by chromatographic methods. Direct analysis of samples is scarcely employed and most proposed methodologies include a sample pre-treatment in order to remove matrix interferents and, in some cases, pre-concentrate extracts. Current extraction methods for NPS determination in plasma/serum, urine, and oral fluids have been widely discussed, such as liquid-liquid, solid-phase, and micro extraction approaches, highlighting the advantages and drawbacks of the proposed extraction methodologies. Regarding microextraction approaches, techniques like microextraction by packed sorbent, solid-phase microextraction, miniaturized solid phase extraction, and dispersive liquid-liquid extraction have been proposed for NPS determination in biological fluids with reliable analytical results.


Assuntos
Líquidos Corporais/química , Testes de Química Clínica/métodos , Psicotrópicos/análise , Cromatografia , Testes de Química Clínica/normas , Testes de Química Clínica/tendências , Humanos , Microextração em Fase Líquida , Extração Líquido-Líquido , Psicotrópicos/sangue , Psicotrópicos/urina , Saliva/química , Extração em Fase Sólida , Microextração em Fase Sólida , Manejo de Espécimes/normas
11.
Rev Esp Quimioter ; 33(6): 466-484, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33070578

RESUMO

The high transmissibility of SARS-CoV-2 before and shortly after the onset of symptoms suggests that only diagnosing and isolating symptomatic patients may not be sufficient to interrupt the spread of infection; therefore, public health measures such as personal distancing are also necessary. Additionally, it will be important to detect the newly infected individuals who remain asymptomatic, which may account for 50% or more of the cases. Molecular techniques are the "gold standard" for the diagnosis of SARS-CoV-2 infection. However, the massive use of these techniques has generated some problems. On the one hand, the scarcity of resources (analyzers, fungibles and reagents), and on the other the delay in the notification of results. These two facts translate into a lag in the application of isolation measures among cases and contacts, which favors the spread of the infection. Antigen detection tests are also direct diagnostic methods, with the advantage of obtaining the result in a few minutes and at the very "pointof-care". Furthermore, the simplicity and low cost of these tests allow them to be repeated on successive days in certain clinical settings. The sensitivity of antigen tests is generally lower than that of nucleic acid tests, although their specificity is comparable. Antigenic tests have been shown to be more valid in the days around the onset of symptoms, when the viral load in the nasopharynx is higher. Having a rapid and real-time viral detection assay such as the antigen test has been shown to be more useful to control the spread of the infection than more sensitive tests, but with greater cost and response time, such as in case of molecular tests. The main health institutions such as the WHO, the CDC and the Ministry of Health of the Government of Spain propose the use of antigenic tests in a wide variety of strategies to respond to the pandemic. This document aims to support physicians involved in the care of patients with suspected SC2 infection, in the context of a growing incidence in Spain since September 2020, which already represents the second pandemic wave of COVID-19.


Assuntos
Antígenos Virais/sangue , /diagnóstico , Consenso , Pandemias , /imunologia , Doença Aguda , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Algoritmos , /mortalidade , /normas , Criança , Pré-Escolar , Busca de Comunicante , Emergências , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Nasofaringe/virologia , Sensibilidade e Especificidade , Espanha/epidemiologia , Manejo de Espécimes/métodos , Manejo de Espécimes/normas , Adulto Jovem
12.
Exp Parasitol ; 219: 108014, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33011238

RESUMO

The objective set by WHO to reach elimination of human African trypanosomiasis (HAT) as a public health problem by 2020 is being achieved. The next target is the interruption of gambiense-HAT transmission in humans by 2030. To monitor progress towards this target, in areas where specialized local HAT control capacities will disappear, is a major challenge. Test specimens should be easily collectable and safely transportable such as dried blood spots (DBS). Monitoring tests performed in regional reference centres should be reliable, cheap and allow analysis of large numbers of specimens in a high-throughput format. The aim of this study was to assess the analytical sensitivity of Loopamp, M18S quantitative real-time PCR (M18S qPCR) and TgsGP qPCR as molecular diagnostic tests for the presence of Trypanosoma brucei gambiense in DBS. The sensitivity of the Loopamp test, with a detection limit of 100 trypanosomes/mL, was in the range of parasitaemias commonly observed in HAT patients, while detection limits for M18S and TgsGP qPCR were respectively 1000 and 10,000 trypanosomes/mL. None of the tests was entirely suitable for high-throughput use and further development and implementation of sensitive high-throughput molecular tools for monitoring HAT elimination are needed.


Assuntos
Técnicas de Diagnóstico Molecular/normas , Técnicas de Amplificação de Ácido Nucleico/normas , Reação em Cadeia da Polimerase em Tempo Real/normas , Trypanosoma brucei gambiense/isolamento & purificação , Tripanossomíase Africana/prevenção & controle , Algoritmos , Animais , Coleta de Amostras Sanguíneas/métodos , Coleta de Amostras Sanguíneas/normas , DNA de Protozoário/isolamento & purificação , Ensaios de Triagem em Larga Escala/métodos , Ensaios de Triagem em Larga Escala/normas , Humanos , Camundongos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Manejo de Espécimes/métodos , Manejo de Espécimes/normas , Trypanosoma brucei gambiense/genética , Tripanossomíase Africana/sangue , Tripanossomíase Africana/diagnóstico
13.
J Forensic Leg Med ; 76: 102067, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33032204

RESUMO

On 31 December 2019, health authorities in the People's Republic of China informed the World Health Organization of a then limited outbreak of interstitial viral pneumonia, identified at a laboratory in the city of Wuhan. In mid-April 2020 this outbreak of COVID-19 (as the disease has been called) has aggravated and spread worldwide, causing more than 200,000 deaths and affecting especially the United States, Spain, Italy, France and the United Kingdom. Despite the severity of the outbreak, the pathological findings have not been described in detail and there are very few guidelines or protocols for conducting autopsy studies on patients who have died from COVID-19. There are currently very few histopathological case series studies on this disease. In addition, some of these studies have been performed on biopsies or surgical resection pieces from patients in whom disease was subsequently demonstrated or through minimally invasive autopsy protocols. None of the studies offer a detailed necropsy protocol. This document proposes a protocol of action for the institutes of Forensic Medicine facing the current SARS-CoV2 pandemic, which combines protection of worker safety with optimization of tissue collection.


Assuntos
Betacoronavirus , Infecções por Coronavirus/patologia , Patologia Legal/normas , Pneumonia Viral/patologia , Guias de Prática Clínica como Assunto , Manejo de Espécimes/normas , Autopsia , Medicina Legal/normas , Ciências Forenses/normas , Humanos , Pandemias
17.
Viruses ; 12(11)2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33114233

RESUMO

Critical to facilitating SARS-CoV-2 point-of-care (POC) testing is assurance that viruses present in specimens are inactivated onsite prior to processing. Here, we conducted experiments to determine the virucidal activity of commercially available Viral Transport Mediums (VTMs) to inactivate SARS-CoV-2. Independent testing methods for viral inactivation testing were applied, including a previously described World Health Organization (WHO) protocol, in addition to a buffer exchange method where the virus is physically separated from the VTM post exposure. The latter method enables sensitive detection of viral viability at higher viral titre when incubated with VTM. We demonstrate that VTM formulations, Primestore® Molecular Transport Medium (MTM) and COPAN eNAT™ completely inactivate high-titre SARS-CoV-2 virus (>1 × 107 copies/mL) and are compatible with POC processing. Furthermore, full viral inactivation was rapidly achieved in as little as 2 min of VTM exposure. We conclude that adding certain VTM formulations as a first step post specimen collection will render SARS-CoV-2 non-infectious for transport, or for further in-field POC molecular testing using rapid turnaround GeneXpert platforms or equivalent.


Assuntos
Betacoronavirus/isolamento & purificação , Testes Imediatos , Manejo de Espécimes , Inativação de Vírus , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Meios de Cultura/análise , Meios de Cultura/farmacologia , Humanos , Testes Imediatos/normas , Manejo de Espécimes/métodos , Manejo de Espécimes/normas , Carga Viral/efeitos dos fármacos , Inativação de Vírus/efeitos dos fármacos
20.
Virus Res ; 290: 198173, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32979475

RESUMO

BACKGROUND: The CDC protocol for SARS-CoV2 RT-PCR diagnosis (2019-nCoV CDC kit) is considered a gold standard worldwide; based on three different FAM probes (N1 and N2 for viral detection; RP for RNA extraction quality control), three reactions per sample are needed for SARS-CoV-2 diagnosis. RESULTS: We herein describe a sample pooling protocol: pooling 3 RNA extractions into a single PCR reaction; we tested this protocol with 114 specimens grouped in 38 pools and found no significant differences for N1 and N2 Ct values between pool and single sample PCR reaction. CONCLUSION: This pool of three protocol has a sensitivity of 100 % compared to the standard single sample protocol. For a typical 96-well plate, this pool assay allows 96 samples processing, speeding up diagnosis and reducing cost while maintaining clinical performance, particularly useful for SARS-CoV-2 diagnosis at developing countries.


Assuntos
/diagnóstico , Manejo de Espécimes/métodos , /economia , Testes Diagnósticos de Rotina , Humanos , Nasofaringe/virologia , RNA Viral/genética , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Manejo de Espécimes/normas , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA