ABSTRACT
ABSTRACT INTRODUCTION: The adequacy of biological samples is a critical and important item in the clinical laboratory, so that reliable results can be obtained for patients. OBJECTIVE: To ensure integrity and stability of biological samples during the transport process. METHOD: Concurrent validation was carried out - in parallel with the production process and distribution of the product, from January to March 2017. The blood samples were packaged primarily in tube racks, and those of urine, feces and microbiological materials were packed in plastic bags. Materials were wrapped in a blanket of absorbent material to ensure temperature integrity and to avoid possible material losses. Thermal bags were the containers used to carry the samples. There were five transport routes, with two daily routes for each collection unit. A recommendation of the number of ice packs, predefined by the laboratory, was followed. RESULTS AND CONCLUSION: In the first month, the pre-established temperatures (blood: 10°C to 22°C/urine-feces: 2°C to 8°C) were not reached until arrival at the central laboratory, and the amount of ice in each bag was gradually increased, daily, until reaching the ideal temperature, in all collection units and the central. Transport routes were changed three times in the most distant units. Materials that arrived outside specifications were processed with restrictions, and results were evaluated by the professional responsible for the release. After these modifications, the temperature records of the biological materials were in accordance with the current legislation and the defined specifications, thus validating the process.
RESUMO INTRODUÇÃO: A adequação das amostras biológicas é um item crítico e importante no laboratório clínico, para que possamos oferecer resultados confiáveis aos pacientes. OBJETIVO: Garantir a integridade e a estabilidade das amostras biológicas durante o processo de transporte. MÉTODO: Foi realizada validação concorrente - concomitantemente ao processo produtivo e à distribuição do produto, no período de janeiro a março de 2017. As amostras de sangue foram acondicionadas primariamente em galerias; as de urina, fezes e materiais microbiológicos, em sacos plásticos. Os materiais foram envoltos por uma manta de material absorvente para garantir a integridade da temperatura e evitar possíveis perdas de material. Maletas térmicas foram os recipientes utilizados para transportar as amostras. Havia cinco rotas de transporte, com dois percursos diários para cada unidade de coleta. Foi seguida a recomendação da quantidade de barras de gelo predefinida pelo laboratório. RESULTADOS E CONCLUSÃO: No primeiro mês, as temperaturas preestabelecidas (sangue: 10°C a 22°C/urina e fezes: 2°C a 8°C) não foram atingidas até a chegada à matriz, e aumentou-se gradativamente a quantidade de gelo em cada maleta, com avaliações diárias, até se atingir a temperatura ideal, em todas as unidades de coleta e na matriz. Foi realizada mudança nas rotas de transporte com frequência de três vezes nas unidades mais distantes. Os materiais que chegaram fora das especificações foram processados com restrição; e os resultados, avaliados pelo profissional responsável pela liberação. Após essas modificações, os registros de temperatura dos materiais biológicos estavam de acordo com a legislação vigente e as especificações definidas, validando, portanto, o processo.
ABSTRACT
INTRODUCTION: Myocardial stiffness is an important determinant of cardiac function and is currently invasively and indirectly assessed by catheter angiography. This study aims to demonstrate the feasibility of quantifying right ventricular (RV) stiffness noninvasively using cardiac magnetic resonance elastography (CMRE) in dogs with severe congenital pulmonary valve stenosis (PVS) causing RV hypertrophy, and compare it to remote myocardium in the left ventricle (LV). Additionally, correlations between stiffness and selected pathophysiologic indicators from transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging were explored. METHODS: In-vivo CMRE was performed on nine dogs presenting severe congenital PVS using a 1.5T MRI scanner. T1-MOLLI, T2-prepared-bSSFP, gated-cine GRE-MRE and LGE (PSIR) sequences were used to acquire a basal short-axis slice. RV and LV-free-wall (FW) stiffness measurements were compared against each other and also correlated to ventricular mass, RV and LV FW thickness, T1 and T2 relaxation times, and extracellular volume fraction (ECV). Peak transpulmonary pressure gradient and myocardial strain were also acquired on eight dogs by TTE and correlated to RV-FW systolic stiffness. Potential correlations were evaluated by Spearman's rho (rs). RESULTS: RV-FW stiffness was found to be significantly higher than the LV-FW stiffness both during end-systole (ES) (p=0.002) and end-diastole (ED) (p=0.029). Significant correlations were observed between RV-FW ES and LV-FW ED stiffness versus ECV (rs=0.75; p-value=0.05). Non-significant moderate correlations were found between LV-FW ES (rs=0.54) and RV-FW ED (rs=0.61) stiffness versus ECV. Furthermore, non-significant correlations were found between RV or LV-FW stiffness and the remaining variables (rs<0.54; p-value>0.05). CONCLUSION: This study demonstrates the feasibility of determining RV stiffness. The positive correlations between stiffness and ECV might indicate some interdependence between stiffness and myocardial extracellular matrix alterations. However, further studies are warranted to validate our initial observations.
