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1.
Biochem Med (Zagreb) ; 30(1): 010703, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31839723

RESUMO

Introduction: Circulating microRNAs (miRNAs) are emerging as potential biomarkers. However, the lack of preanalytical and analytical standardization limits their use. The aim of this study was to determine the expression of different miRNAs in plasma according to different collection and storage conditions. Materials and methods: Venous blood from 10 volunteers was collected in tubes spray-coated with dipotassium salt of ethylendiaminetetraacetic acid, either with (plasma-preparation tube, PPT) or without (K2EDTA) gel separator. Platelet-poor plasma (PPP) was also obtained from K2EDTA plasma. After storage under different conditions, miRNA-enriched total RNA was isolated from plasma and reverse transcribed. A panel of 179 miRNAs was assayed by quantitative polymerase chain reaction and the results were analysed by GenEx software. Detectability and stability of miRNAs were determined. Results: The number of undetected miRNAs was: 18, 24, and 22 in PPT; 83, 43, and 20 in K2EDTA; and 76, 106, and 104 in PPP samples, for plasma immediately frozen at - 80°C and plasma stored for 24h at room temperature or 4°C, respectively. Circulating miRNA expression in PPT samples was not affected by storage delay or temperature, while the percentage of up- and down-regulated miRNA in K2EDTA and PPP samples ranged from 2%, and 1% to 7%, and 5%, respectively. Conclusions: Sample matrix, temperature and delay in storage strongly influence the expression level of plasma miRNAs. Our results indicate PPT tubes as the most suitable matrix to improve total miRNA detectability and stability, independently of temperature.


Assuntos
Coleta de Amostras Sanguíneas/métodos , MicroRNA Circulante/sangue , Adulto , Biomarcadores/sangue , Plaquetas/citologia , Coleta de Amostras Sanguíneas/instrumentação , MicroRNA Circulante/isolamento & purificação , MicroRNA Circulante/metabolismo , Humanos , Masculino , Fase Pré-Analítica , Temperatura Ambiente
2.
Biochem Med (Zagreb) ; 30(1): 010704, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31839724

RESUMO

Introduction: Diabetes mellitus (DM) is one of the most prevalent diseases worldwide. The objective of this study was to find out under what preanalytical conditions routine and diagnostic glucose tests are performed across Spanish laboratories; and also what criteria are used for DM diagnosis. Materials and methods: An online survey was performed by the Commission on Quality Assurance in the Extra-Analytical Phase of the Spanish Society of Laboratory Medicine (SEQC-ML). Access to the questionnaire was available on the home page of the SEQC-ML website during the period April-July 2018. Data analysis was conducted with the IBM SPSS© Statistics (version 20.0) program. Results: A total of 96 valid surveys were obtained. Most laboratories were in public ownership, serving hospital and primary care patients, with high and medium workloads, and a predominance of mixed routine-urgent glucose testing. Serum tubes were the most used for routine glucose analysis (92%) and DM diagnosis (54%); followed by lithium-heparin plasma tubes (62%), intended primarily for urgent glucose testing; point-of-care testing devices were used by 37%; and plasma tubes with a glycolysis inhibitor, mainly sodium fluoride, by 19%. Laboratories used the cut-off values and criteria recognized worldwide for DM diagnosis in adults and glucose-impaired tolerance, but diverged in terms of fasting plasma glucose and gestational DM criteria. Conclusion: Preanalytical processing of routine and DM diagnostic glucose testing in Spain does not allow a significant, non-quantified influence of glycolysis on the results to be ruled out. Possible adverse consequences include a delay in diagnosis and possible under-treatment.


Assuntos
Glicemia/análise , Coleta de Amostras Sanguíneas/métodos , Coleta de Amostras Sanguíneas/instrumentação , Diabetes Mellitus/diagnóstico , Humanos , Laboratórios Hospitalares/normas , Fase Pré-Analítica , Espanha , Inquéritos e Questionários
3.
Am J Vet Res ; 80(11): 995-1000, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31644346

RESUMO

OBJECTIVE: To compare glucose concentrations in peripheral venous and capillary blood samples collected from dogs before and after consumption of a meal and measured with a veterinary-specific portable blood glucose meter (PBGM). ANIMALS: 12 dogs (96 blood samples). PROCEDURES: A veterinary-specific PBGM was used to measure blood glucose concentrations. Glucose concentrations in capillary blood samples obtained from the carpal pad, medial aspect of a pinna, and oral mucosa were compared with glucose concentrations in blood samples obtained from a lateral saphenous vein. Samples were collected after food was withheld for 12 hours and again 2 hours after consumption of a meal. RESULTS: Location of capillary blood collection had a significant effect on glucose concentrations measured with the PBGM. Glucose concentration in capillary blood collected from the medial aspect of the pinna did not differ significantly from the glucose concentration in peripheral venous blood samples, whereas glucose concentrations in blood samples collected from the carpal pad and oral mucosa differed significantly from the glucose concentration in peripheral venous blood samples. There was no significant difference between preprandial and postprandial blood glucose concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Glucose concentrations in capillary blood collected from the medial aspect of the pinna of dogs better reflected glucose concentrations in venous blood than concentrations measured in capillary blood collected from the carpal pad or oral mucosa.


Assuntos
Glicemia/análise , Coleta de Amostras Sanguíneas/veterinária , Cães/sangue , Animais , Coleta de Amostras Sanguíneas/métodos , Ingestão de Alimentos , Feminino , Masculino , Período Pós-Prandial
4.
Pharm Res ; 36(12): 169, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31654236

RESUMO

PURPOSE: The purpose of this study was to validate a ligand binding assay for the quantitation of a monoclonal antibody-based biotherapeutics (PF-57781346) in samples collected via capillary microsampling to support a regulated mouse toxicity study. METHOD: A quantitative ligand binding assay on the Gyrolab platform was developed to quantify PF-57781346 in blood samples derived from capillary mouse serial sampling. The method validation evaluated assay characteristics including accuracy and precision, influence of sample processing on drug quantitation, whole blood matrix selectivity, dilution linearity and the stability of the drug in the study sample matrix. RESULTS: The method validation demonstrated acceptable analytical characteristics. The whole blood selectivity testing demonstrated accuracy between -4.8% and 13.9% in 10 out of 10 individual whole blood samples, suggesting that drug quantitation from whole blood is not impacted by the serial sampling procedure. Short-term and long-term drug stability in study sample matrix were established to cover required stability for sample storage and analysis (accuracy between -7.3% and 6.1%). CONCLUSION: We reported a successful validation of a bioanalytical method that quantifies PF-55781346 in samples collected via capillary microsampling. The experience shared in this study could serve as a model process for bioanalytical method validation when capillary microsampling is used.


Assuntos
Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/toxicidade , Imunoensaio/métodos , Animais , Coleta de Amostras Sanguíneas/métodos , Estabilidade de Medicamentos , Ligantes , Camundongos , Modelos Animais , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Toxicocinética
5.
Artigo em Inglês | MEDLINE | ID: mdl-31629309

RESUMO

Isoformononetin (methoxy isoflavone) is a potent osteogenic isoflavone abundantly present in Butea monosperma, Pisum sativum, Mung bean, Machaerium villosum, Medicago sativa, and Glycine max. In the current study, an LC-ESI-MS/MS method for the simultaneous evaluation of isoformononetin (IFN), daidzein (DZN) and equol (EQL) was developed and validated in rat plasma using biochanin A as an internal standard. IFN, DZN, and EQL separation was achieved by using acetonitrile and acetic acid (0.1%) in the ratio of 90:10 (% v/v) as mobile phase under isocratic conditions at a flow rate of 0.6 mL/min on Atlantis C18 (4.6 × 250 mm, 5.0 µm) column. The achieved method was linear within the concentration range of 0.5-500 ng/mL. The method was effectively applied to investigate the permeability, protein binding estimation and pharmacokinetics studies of IFN in rats. The PAMPA permeability of IFN was found to be high at pH 4.0 and 7.0. The protein binding was found to be about 91% of IFN. The oral bioavailability of IFN was found to be poor (21.6%). IFN was found to have a moderate clearance (2.9 L/h/kg) and a large apparent volume of distribution (12.1 L/kg). The plasma half-life (t1/2) and maximum attainable concentration (Cmax) of IFN at systemic circulation was found to be 1.9 ±â€¯0.6 h and 269.3 ±â€¯0.4 after oral administration.


Assuntos
Equol/farmacocinética , Isoflavonas/farmacocinética , Espectrometria de Massas em Tandem/métodos , Animais , Técnicas Biossensoriais/métodos , Coleta de Amostras Sanguíneas/métodos , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Genisteína/farmacocinética , Genisteína/normas , Permeabilidade , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray/métodos
6.
Rev Bras Epidemiol ; 22Suppl 02(Suppl 02): E190004.SUPL.2, 2019.
Artigo em Português, Inglês | MEDLINE | ID: mdl-31596375

RESUMO

INTRODUCTION: This article aims at describing the National Health Survey (Pesquisa Nacional de Saúde- PNS) methodology of collecting laboratory exams data. METHODOLOGY: A subsample of 25% of the census tracts was selected, according to the stratification of the PNS sample, with a probability inversely proportional to the difficulty of collection. The collection of blood and urine was done in the households by a laboratory agent, among residents selected for individual interview. Due to the difficulties found in the field work, the sample did not reach the minimum expected number in some strata, and a post-stratification procedure was proposed for the data analysis. RESULTS: The collection of biospecimens was performed in 8,952 individuals. Laboratory tests were: glycated hemoglobin; total cholesterol; LDL cholesterol; HDL cholesterol; serology for dengue; red blood cell count (erythrogram) and white series count (leukogram); high performance liquid chromatography (HPLC) for diagnosis of hemoglobinopathies; creatinine. Theexcretion of potassium, salt and sodium and creatinine was estimated in the urine. The database of laboratory exams was weighed and made publicly available on the Oswaldo Cruz Foundation's PNS website and can be accessed without prior authorization. CONCLUSION: The total subsample of laboratory exams is of great value, since it allowed us to establish national reference parameters adequate to sociodemographic and geographic characteristics of the Brazilian population, providing relevant and complementary information for the analysis of the health situation of Brazil.


Assuntos
Técnicas de Laboratório Clínico/métodos , Coleta de Dados/métodos , Bases de Dados Factuais , Inquéritos Epidemiológicos/métodos , Adolescente , Adulto , Coleta de Amostras Sanguíneas/métodos , Brasil , Colesterol/sangue , Cromatografia Líquida de Alta Pressão , Dengue/sangue , Contagem de Eritrócitos , Feminino , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Coleta de Urina/métodos , Adulto Jovem
7.
Biochem Med (Zagreb) ; 29(3): 030708, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31624461

RESUMO

Introduction: The aim of this study was to compare ionized calcium (iCa) concentrations in arterial heparinized blood and venous serum and to investigate time-dependent variation of iCa in serum samples centrifuged and analysed at different times. Materials and methods: Ionized calcium was measured (N = 25) in arterial blood within 20 min after puncture, and in serum within 10 min after centrifugation conducted 30 min after sampling. Effect of time between sampling and centrifugation was examined in three tubes (N = 30) centrifuged 15, 30 and 60 min after sampling, and analysed within 10 min. Effect of time between centrifugation and analysis was investigated in three tubes (N = 31) centrifuged 30 min after sampling and analysed: 0-10, 30-40 and 90-100 min after centrifugation. Ionized calcium was measured on the Siemens RapidLab 348EX analysers. Statistical significance was tested using Wilcoxon test and ANOVA analysis. Clinical significance was judged against reference change values (RCV). Results: No statistically significant difference was found between iCa in arterial blood and serum (P = 0.274). A statistically significant decrease was found: in tubes centrifuged 60 and 15 min after sampling versus 30 min (P = 0.005, P = 0.003); and in tubes analysed 30-40 and 90-100 min after centrifugation versus 0-10 min (P = 0.021, P = 0.027). Clinically significant changes were observed: 60 versus 30 min (centrifugation) and 90-100 versus 0-10 and 30-40 min (analysis). Conclusions: Timely analysed arterial blood and serum samples can be used interchangeably. To avoid clinically significant variations, serum tubes should be centrifuged within 30 min after sampling, and analysis should be performed within 30 min after centrifugation.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Cálcio/sangue , Heparina/sangue , Humanos , Concentração de Íons de Hidrogênio , Manejo de Espécimes/métodos
8.
BMC Res Notes ; 12(1): 511, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31416482

RESUMO

OBJECTIVE: Type I interferons (IFN) have important roles in many immune-mediated inflammatory diseases (IMIDs) and are a relatively new therapeutic target. Direct detection of type I IFNs has proved challenging, thus their presence is often inferred from the expression of interferon-stimulated genes (ISGs) and calculation of an interferon score (IS). The objective of this research was to determine if the expression of six common ISGs and subsequent IS were comparable when RNA was derived from the Tempus and PAXgene whole blood RNA collection systems. RESULTS: Whole blood was obtained from ten healthy adults, incubated ex vivo in the absence and presence of recombinant human IFNα then divided into PAXgene and Tempus tubes. Despite reports of tube-specific patterns of gene expression, quantitative PCR (qPCR) analysis revealed no significant differences between PAXgene and Tempus tubes in either the homeostatic or IFNα-induced expression of six ISGs (IFI27, IFI44L, IFIT1, ISG15, RSAD2, SIGLEC1). Overall there was a strong correlation in the IS between unstimulated (r = 0.92, p = 0.0005) and IFNα-stimulated (r = 0.71, p = 0.0268) samples derived from the PAXgene and Tempus tubes.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Perfilação da Expressão Gênica/métodos , Interferon Tipo I/genética , RNA/genética , Adulto , Coleta de Amostras Sanguíneas/instrumentação , Feminino , Voluntários Saudáveis , Humanos , Interferon Tipo I/sangue , Masculino , RNA/sangue , RNA/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adulto Jovem
9.
Arq. bras. med. vet. zootec. (Online) ; 71(4): 1425-1427, jul.-ago. 2019. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1038638

RESUMO

Cetose subclínica é uma grande preocupação em rebanhos leiteiros, e seu diagnóstico e prevenção podem ter um grande impacto na saúde animal. Este estudo comparou quatro locais diferentes para a coleta de amostras de sangue (jugular, veias mamárias e coccígeas e ponta da cauda) para medição de ß-hidroxibutirato (BHBA), usando-se um medidor portátil automático. Foram utilizadas seis vacas Holandesas, e a coleta de sangue foi feita no segundo, quinto, 10º, 15º e 21º dias pós-parto. Os resultados do medidor portátil foram semelhantes aos resultados do laboratório e apresentaram uma correlação forte de 0,83. As concentrações séricas de BHBA nas amostras de sangue coletadas na ponta da cauda, na jugular e na coccígea foram semelhantes. No entanto, o sangue retirado da veia mamária tinha uma concentração mais baixa. Portanto, as amostras de sangue para aferição de BHBA podem ser recolhidas nas veias jugular e coccígeas e na ponta da cauda, sendo as duas últimas as opções mais fáceis para monitorar o BHBA em rebanho leiteiro.(AU)


Assuntos
Animais , Feminino , Bovinos , Coleta de Amostras Sanguíneas/métodos , Coleta de Amostras Sanguíneas/veterinária , Cetose/diagnóstico , Cetose/veterinária , Ácido 3-Hidroxibutírico/sangue
10.
Arch. med. deporte ; 36(192): 227-231, jul.-ago. 2019. tab
Artigo em Espanhol | IBECS | ID: ibc-185179

RESUMO

Introducción: Las exposiciones intermitentes a gran altitud tienen efectos agudos sobre algunos marcadores biológicos, como la testosterona, pero no así en baja altitud. Dado que el entrenamiento de soldados debería ir asociado a tareas militares específicas, adquiere gran importancia valorar los cambios fisiológicos que puedan producirse en determinadas circunstancias (como la altitud) pero durante la realización de actividades propias de las unidades militares. Objetivo: Identificar los cambios hematológicos y en las hormonas Testosterona Libre (TL), Testosterona Total (TT ) y Cortisol en una marcha nocturna a baja altitud en soldados de operaciones en montaña. Metodología: 32 Militares masculinos (26,3 ± 4,50 años, 75,1 ± 7,6 kg) realizaron una marcha invernal nocturna con equipo y un desnivel entre los 902 y 1648 m. Se obtuvieron muestras de sangre antes y después de la marcha y se midió TL, TT, cortisol y hemograma: hematíes (Hmt), hemoglobina (Hb), hematocrito (Htto) y volumen corpuscular medio (VCM). Resultados: Se produjo un descenso significativo de los valores de TL y TT sin cambios en el cortisol plasmático. También se observó un descenso en las cifras de Hmt, Hb, Htto y VCM. Conclusión: Una marcha invernal con equipo de combate, en baja altitud y con un desnivel de 746 m, produce un descenso significativo de los valores plasmáticos de Testosterona (libre y total) en soldados de una unidad de operaciones en montaña. No se observan cambios en los valores de cortisol. Se detecta una reducción significativa de hematíes, hemoglobina, hematocrito y VCM que podrían deberse a un efecto de hemodilución


Introduction: Intermittent exposures at high altitude have acute effects on some biological markers, such as testosterone, but not at low altitude. Since the training of soldiers should carry out specific military activities, is very important to asses physiological changes that can occur in particular circumstances (such as altitude) but during the performance of the activities of the military units. Objective: To identify the hematological changes and the hormones Free Testosterone (TL), Total Testosterone (TT ) and Cortisol during a nocturnal march at low altitude in soldiers of mountain operations. Methodology: 32 male military (26.3 ± 4.50 years, 75.1 ± 7.6 kg) performed a nocturnal winter march with equipment between 902 and 1648 m of altitude. Blood samples were obtained before and after the march, and TL, TT, cortisol and blood count were measured: red blood cells (Hmt), hemoglobin (Hb), hematocrit (Htto) and mean corpuscular volume (MCV ). Results: There was a significant decrease in TL and TT values without changes in plasmatic cortisol. A reduction in the values of Hmt, Hb, Htto and VCM has also been observed. Conclusion: A winter march with combat equipment, at low altitude and with a unevenness of 746 m, produces a significant decrease in the plasma values of Testosterone (free and total) in soldiers of mountain operations. No changes in cortisol values are observed. A significant reduction of red blood cells, hemoglobin, hematocrit and MCV is detected, which could be due to a hemodilution effect


Assuntos
Humanos , Masculino , Adulto , Teste de Caminhada , Militares , Altitude , Hemodiluição , Biomarcadores , Testosterona/análise , Hidrocortisona , Eritrócitos , Hemoglobinas , Coleta de Amostras Sanguíneas/métodos
11.
Bioanalysis ; 11(13): 1233-1242, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31298569

RESUMO

Aim: Following the request of a regulatory authority, a rat study was conducted to compare pharmacokinetic parameters from traditional large volume sampling and capillary microsampling. Materials & methods: Rats were dosed with a proprietary compound in three dose groups and blood samples were collected via capillary microsampling (32 µl), immediately followed by traditional large volume sampling (300 µl) up to 24 h postdose. Resulting plasma samples were analyzed for parent drug and two metabolites. AUCs were compared between sampling techniques. Results: There was no statistical difference between AUCs from traditional and microsampling across different doses and analytes. Conclusion: Toxicokinetic parameters generated from plasma collected as a capillary microsample or traditional large volume sample are highly comparable.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Preparações Farmacêuticas/metabolismo , Animais , Área Sob a Curva , Coleta de Amostras Sanguíneas/normas , Capilares , Cromatografia Líquida de Alta Pressão , Teste em Amostras de Sangue Seco , Meia-Vida , Masculino , Preparações Farmacêuticas/sangue , Preparações Farmacêuticas/química , Curva ROC , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem
12.
Clin Lab ; 65(7)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31307157

RESUMO

BACKGROUND: Intraosseous (IO) access is often indicated for administration of drugs and fluids in emergencies when venous access is challenging. There is no consensus regarding whether and which laboratory analyses may be performed on IO aspirates, and research on hemodynamically unstable subjects is limited. METHODS: Twelve anesthetized pigs were sampled from IO, venous, and arterial accesses during stable circulation and after hemorrhage corresponding to 20% and 40% of the blood volume. Samples were analyzed for blood gases and acid-base status, electrolytes, hematocrit, creatinine, glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (γ-GT), alkaline phosphatase (ALP), and creatine kinase (CK). RESULTS: Average differences of blood gases and acid-base parameters, sodium, creatinine, hematocrit, ALT, and γ-GT and between IO and venous samples were small at baseline and after hemorrhage while differences for lactate and glucose increased with hypovolemia. Both IO-arterial and venoarterial differences in acid-base parameters increased with hypovolemia. Dispersions of differences were often large. CONCLUSIONS: Average levels of blood gases, acid base parameters, hematocrit, CK, AST, γ-GT, creatinine, and ALT, but not lactate and glucose, were similar in IO and venous samples in hypovolemia. However, precision was limited, indicating that IO test results should be confirmed when other vascular access is established, and that analysis of IO samples should be limited to acute situations and not used for detailed diagnostics in this setting.


Assuntos
Artérias , Coleta de Amostras Sanguíneas/métodos , Medula Óssea , Choque Hemorrágico/sangue , Veias , Alanina Transaminase/sangue , Fosfatase Alcalina/sangue , Animais , Aspartato Aminotransferases/sangue , Gasometria/métodos , Creatina Quinase/sangue , Hematócrito , Hipovolemia/sangue , Infusões Intraósseas , Masculino , Estudos Prospectivos , Suínos , gama-Glutamiltransferase/sangue
13.
Medicine (Baltimore) ; 98(26): e16130, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31261534

RESUMO

Pro-gastrin-releasing peptide (ProGRP) is the promising molecular tumor marker of small cell lung cancer (SCLC). Here we study the influence of different blood samples treatment methods on ProGRP.Serum with and without separation gel and heparin plasma from 10 SCLC patients and 5 healthy individuals were assayed for ProGRP immediately and 2, 4, 6, 8, 24, and 48 hours after collection.ProGRP of serum with and without separation gel and heparin plasma detected immediately was basically consistent, whereas there was a significant difference in the level of them assayed after 2 hours. No significant variation with time was observed in heparin plasma, but in serum with and without separation gel, ProGRP concentrations gradually declined with time, with statistical significance. When assayed within 2 hours, each time point of ProGRP in heparin plasma had no significant difference and the difference of PrpGRP in serum separating gel existed at 1.5 hours.Heparin plasma is the best option for clinical test of ProGRP. If serum with separation gel is used, optimization methods of turn-around-time which guarantee samples detected within 1 hour after collection can make results more instructive for clinical treatment.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Peptídeo Liberador de Gastrina/sangue , Biomarcadores Tumorais/sangue , Humanos , Neoplasias Pulmonares/sangue , Carcinoma de Pequenas Células do Pulmão/sangue , Fatores de Tempo
14.
J Pharm Biomed Anal ; 175: 112772, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31362248

RESUMO

Blood microsampling is desired in clinical, pharmaceutical and biomedical fields to overcome the challenges of conventional whole blood sampling. One of the popular methods for blood microsampling is the dried blood spot (DBS) kit and the collected sample is subsequently used for bioanalysis. The current practice of DBS is simple to use, cheap and very well standardized from sample collection to analysis. However, DBS suffers from several well documented challenges related to blood spot formation such as varying hematocrit volume, thin layer chromatography effect and subsequent bio-analysis resulting in a variable and ocassionally high failure rate. A major source of these problems is our limited understanding of blood flow in porous media under different ambient and material conditions. Therefore, it is highly desirable to understand the parameters that affect blood flow in a porous medium to enable a more robust design of DBS and generally blood microsampling kits. In this review, we discuss some existing blood microsampling techniques while focusing on the challenges associated with blood flow dynamics. We also review existing studies on the potential factors that affect the permeation (imbibition or wicking) and spreading of blood in a thin, porous substrate as means to understand and overcome the challenges in designing new DBS kits and blood microsampling devices. Thereafter, we have discussed recent advances in the design of passive flow-based devices to overcome these challenges of current blood microsampling by DBS. Finally, we present a few applications of DBS in clinical and non-clinical studies. This review can benefit researchers working at the interface of complex fluid flow, surface chemistry, and material and device design for biomedical and biological applications.


Assuntos
Fluxo Sanguíneo Regional/fisiologia , Animais , Coleta de Amostras Sanguíneas/métodos , Teste em Amostras de Sangue Seco/métodos , Hematócrito/métodos , Humanos , Porosidade , Manejo de Espécimes/métodos
15.
Clin Lab ; 65(6)2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31232016

RESUMO

BACKGROUND: Zinc and copper are among the most important trace elements. Deficiencies of these trace elements cause a wide variety of disorders. The present study aims to report the definitive assessment of biological variation (BV) parameters for these elements as within-subject BV (CVI), between subject BV (CVG), index of individuality (II), and reference change value (RCV) in a Turkish cohort study group. METHODS: Ten blood specimens were collected weekly from 20 healthy volunteers (13 women, 7 men) for 10 weeks. Collected sera were stored at -80°C until the time of analysis. Serum zinc and copper levels were analyzed with atomic absorption spectrometry and ANOVA test was used to calculate the variations. RESULTS: The CVI and CVG for zinc were 6.26% and 23.27%, respectively. Analytical variation (CVA) was calculated as 4.24%. II and RCV for zinc were calculated as 0.26 and 21.51%, respectively. The CVI and CVG for copper were 6.05% and 19.64%, respectively. CVA was calculated as 4.24%. II and RCV for copper were calculated as 0.31 and 20.47%, respectively. CONCLUSIONS: Since II values were less than 0.6 for both analytes, the reference values will be of little use. RCV might be preferred for better evaluation instead.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Voluntários Saudáveis , Zinco/sangue , Adulto , Estudos de Coortes , Cobre/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Espectrofotometria Atômica
16.
Vasc Health Risk Manag ; 15: 143-147, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239692

RESUMO

Introduction: Conventional venous blood collection requires a puncture with a needle through the endothelium of a vessel. The endothelial injury causes activation of circulating platelets and the release of thromboxane A2. The aim of the study was to investigate if platelets continue to form thromboxane A2 in the blood tube after sample collection, but such synthesis would give false information about the actual circulating thromboxane A2 value. Methods: Thromboxane B2 is a biologically inactive but stable metabolite of thromboxane A2 and can be measured in blood samples by a standard enzyme immunoassay. Thromboxane B2 measurements reflect thromboxane A2 concentration. Blood samples were collected in 3.2% sodium citrate vials and EDTA vials from ten individuals and centrifuged and frozen at different time points (0, 30, and 120 minutes). Plasma aliquots were transferred to and frozen in 1.8 mL polypropylene tubes and the citrate samples were also transferred to and frozen in propylene tubes containing indomethacin. Results: Concentrations of thromboxane B2 in plasma samples collected in citrate vials and stored in propylene tubes increased very rapidly as the samples were left for longer after sampling and allowed to stand at room temperature. After 120 minutes, the amount of thromboxane B2 was 400% higher than in the reference sample at time zero. In comparison, thromboxane B2 concentration was about 200% higher in the 120-minute samples compared to the reference in samples collected in citrate vials but stored in indomethacin tubes. In samples collected in EDTA vials, a 10% reduction in thromboxane B2 concentration in the 120-minute samples was observed. Conclusion: Storage conditions, type of sampling vial and time from sampling until sample processing (centrifuging) has a major impact on thromboxane B2 stability.


Assuntos
Plaquetas/metabolismo , Coleta de Amostras Sanguíneas/métodos , Tromboxano A2/sangue , Tromboxano B2/sangue , Adulto , Biomarcadores/sangue , Centrifugação , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Fatores de Tempo , Adulto Jovem
17.
Radiat Res ; 191(6): 491-496, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31039080

RESUMO

Based on encouraging results from several early-phase clinical trials, there is renewed interest in the use of pharmacological ascorbate (i.e., intravenous administration resulting in >≈10 mM plasma ascorbate concentrations) in combination with standard-of-care cancer treatments including radiation and/or chemotherapy. Under normal, healthy physiological conditions, humans maintain plasma ascorbate concentrations in the range of 40-80 lM. However, in vivo antitumor activity requires supraphysiological plasma concentrations on the order of ≈20 mM. The stability of ascorbate in whole blood has been well studied. The goal of this work was to determine the appropriate handling methods of blood samples, after treatment with pharmacological ascorbate, which allow for the optimal measurement of ascorbate in plasma for dosing verification. Our findings indicate that ascorbate concentrations (mM) are relatively stable in whole blood collected in sodium heparin tubes and stored on ice (or at 4°C) for up to 24 h. After 24 h, ascorbate levels in plasma are relatively stable at 4°C for up to 72 h. At -20°C, plasma concentrations are relatively stable for 2-3 weeks, while at -80°C, ascorbate concentrations in plasma are stable for at least one month. In contrast, patient samples showed better stability when stored as whole blood compared to plasma at 4°C but increasing hemolysis over time may significantly skew ascorbate measurements. Additionally, patient samples can be reliably stored as plasma at -20°C for up to three weeks in either a frost-containing or frost-free environment. This information can guide the collection, processing and storage of clinical samples after pharmacological ascorbate infusions amenable to multi-center clinical trials.


Assuntos
Ácido Ascórbico/sangue , Coleta de Amostras Sanguíneas/métodos , Ensaios Clínicos como Assunto , Temperatura Baixa , Feminino , Humanos , Masculino , Fatores de Tempo
18.
J Pharmacol Toxicol Methods ; 98: 106584, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31100450

RESUMO

INTRODUCTION: The pig is one of the most valuable in vivo models in biomedical research, however with only a few well-accessible veins suitable for venipuncture. Moreover, most of the known methods of blood collection are suitable only for a limited time period. The aim of the study was to verify an improved method of long-term catheterization of the jugular vein in pigs. METHODS: A 420 mm polyurethane catheter 16G tube was surgically inserted using the Seldinger technique. The part of the tube that was not inserted into the vein was threaded through a subcutaneously introduced trocar into the occipital area, where it was well accessible and well protected from damage. The catheters were flushed with sterile 0.9% saline solution and locked with 4% citrate between frequent blood samplings, or with 30% citrate at intervals of 1-2-days. Once a week, the catheters were locked with 4% citrate containing taurolidine for 24 h in order to prevent infection. The method was verified in 14 pigs. RESULTS: The catheters were fully functional for up to 11 weeks and no infection or thrombus was observed. DISCUSSION: This method of catheterization and catheter care allows the realization of long-term experiments with comfortable and stress-free blood sampling.


Assuntos
Cateterismo/métodos , Veias Jugulares/cirurgia , Animais , Coleta de Amostras Sanguíneas/métodos , Feminino , Masculino , Suínos , Taurina/administração & dosagem , Taurina/análogos & derivados , Tiadiazinas/administração & dosagem
19.
Ann Nucl Med ; 33(8): 586-593, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31119608

RESUMO

OBJECTIVE: The objective of the present study was to develop a fully automated blood sampling system for kinetic analysis in mice positron emission tomography (PET) studies. Quantitative PET imaging requires radioactivity concentrations in arterial plasma to estimate the behavior of an administered radiopharmaceutical in target organs. Conventional manual blood sampling has several drawbacks, such as the need for troubleshooting in regard to blood collection, necessary personnel, and the radiation exposure dose. We recently developed and verified the operability of a fully automated blood sampling system (automatic blood dispensing system-ABDS). Here, we report the results of fully quantitative measurements of the cerebral metabolic rate of glucose (CMRglc) in mice using the ABDS. METHODS: Under 1% isoflurane anesthesia, a catheter was inserted into the femoral artery of nine wild-type male mice. Immediately after injection of 18F-fluorodeoxyglucose (FDG) (13.2 ± 3.93 MBq in 0.1 mL saline), arterial blood samples were drawn using the ABDS and then analyzed using CD-Well, a system we previously developed that can measure radioactivity concentration (Bq/µL) using a few microliters of blood in the plasma and whole blood separately. In total, 16 blood samplings were conducted in 60 min as follows: 10 s × 9; 70 s × 2; 120 s × 1; 250 s × 1; 10 min × 2; and 30 min × 1. Dynamic PET scans were conducted concurrently using a small-animal PET/computed tomography (CT) (PET/CT) scanner. Full kinetics modeling using a two-tissue-three-compartment model was applied to calculate CMRglc. Blood volume was also estimated. RESULTS: No significant differences were observed between the manual and ABDS measurements. A proportional error was detected only for plasma. The mean ± standard deviation CMRglc value in the mice was 5.43 ± 1.98 mg/100 g/min (30.2 ± 11 µmol/min/100 g), consistent with a previous report. CONCLUSIONS: The automated microliter-ordered blood sampling system developed in the present study appears to be useful for absolute quantification of CMRglc in mice PET studies.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Tomografia por Emissão de Pósitrons/métodos , Animais , Automação , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Glucose/metabolismo , Cinética , Masculino , Camundongos
20.
J Agric Food Chem ; 67(23): 6665-6671, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31117500

RESUMO

A new sample processing method for analyzing flavonol metabolites in plasma using enzymatic proteolysis was developed and validated. Four endopeptidases were examined regarding their influence on the analyte recovery of quercetin-3- O-glucuronide (Q3GlcA). Methanol was added to inactivate and precipitate the enzymes, and samples were concentrated via evaporation prior to UHPLC-MS analysis. Quercetin-3- O-rutinoside (Q3Rut) was used as an internal standard. The selectivity and accuracy of the established UHPLC-ESI-MS n method showed a coefficient of variation (CV) of the repeatability of the measuring instrument of 1.7% for Q3GlcA. The average recovery of Q3GlcA was approximately 67% with an interday method precision of 24% and r = 46.9 as its repeatability. Therefore, enzymatic proteolysis has proven to be a suitable alternative to the methods previously described in the literature, such as solid-phase extraction (SPE). Still, the method has only been validated for Q3GlcA, but its applicability to other substance classes seems possible.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Cromatografia Líquida de Alta Pressão/métodos , Plasma/química , Espectrometria de Massas em Tandem/métodos , Animais , Proteínas de Bactérias/química , Biocatálise , Flavonoides/sangue , Flavonoides/isolamento & purificação , Humanos , Peptídeo Hidrolases/química , Proteólise , Streptomyces griseus/enzimologia , Suínos
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