ABSTRACT Computational modeling has been proven to be very useful in tissue engineering over the past years. Because the model is a simplification of the experimental system, the processes accounted for in the model should be analyzed carefully. However, new and complex models are usually proposed without a clear comparison with the basic ones. In this study, the contribution of oxygen to Contois growth kinetics and porosity variation with time due to polymer degradation was evaluated through a sensitivity analysis. The effect of initial glucose concentration, porosity and thickness of the scaffold on the cell volume fraction and substrate concentration was analyzed for three models. Even with the inclusion of oxygen concentration in the model, the output variables are more affected by the initial cell number, while the model with variable porosity is quite robust to variations in the input variables.

RESUMOIntrodução:Atualmente, a análise citológica de líquidos biológicos, como líquido peritoneal, é realizada por meio da contagem manual de células, em câmara de Fuchs-Rosenthal. Porém, esse método apresenta uma série de limitações. Com isso, contadores automáticos têm sido avaliados para a contagem de células nesse tipo de amostra a fim de tornar esse exame mais rápido e confiável.Objetivo:Comparar a contagem manual e semiautomatizada de leucócitos e eritrócitos em líquido peritoneal.Materiais e métodos:As amostras foram analisadas manualmente e no contador de células CountessTM (Invitrogen).Resultados:Os resultados mostraram que apesar de existir correlação entre os dois métodos de contagem, essa correlação é relativamente fraca, tanto para análise de leucócitos como para de eritrócitos.Conclusão:Esses resultados sugerem que o líquido peritoneal deve continuar a ser analisado em câmara de Fuchs-Rosenthal, contudo novos estudos devem ser realizados, com maior número de amostras, para investigar a possibilidade do uso de automação na contagem de células em líquidos serosos e, assim, proporcionar maior agilidade e qualidade no resultado.

ABSTRACTIntroduction:Currently, the cytological analysis of biological fluids, such as peritoneal fluid, is performed by manually cells counting in Fuchs-Rosenthal chamber. However, this method has a number of limitations. Because of these limitations, automatic counters have been evaluated for cell counting in this type of sample in order to make it faster and more reliable test.Objective:The aim of this study is to compare the manual and semi-automated leukocytes and erythrocytes counting in peritoneal fluid.Materials and methods:The samples were analyzed manually and using the CountessTM(Invitrogen).Results:The results showed that although there is a correlation between the two counting methods, the correlation is relatively low, for both leukocytes and erythrocytes analysis.Conclusion:The results suggest that peritoneal fluid should continue to be analyzed in Fuchs-Rosenthal chamber. However, further studies should be conducted with a greater number of samples to investigate the possibility of using automated cells counting in serous fluids and, thus, provide greater speed and quality of results.

The objective of this study was to extract poly(3-hydroxybutyrate) (PHB) from the microalgal biomass of Spirulina LEB 18 for the development of nanofibers by electrospinning method. Different extraction methods were tested. The maximum yield obtained was 30.1 ± 2%. It was possible to produce nanofibers with diameters between 826 ± 188 nm and 1,675 ± 194 nm. An increase in the nanofiber diameter occurred when a flow rate of 4.8 μL min-1 and a capillary diameter of 0.90 mm were used. The nanofibers produced had up to 34.4% of biomass additives, i.e., non-PHB materials. This can be advantageous, because it enables the conservation of microalgal biomass compounds with bioactive functions.

The use of umbilical cord blood stem cells is an efficient alternative for the transplantation of hematopoietic progenitor cells. A number of factors can influence the volume and amount of CD34+ cells, which are considered as immature and capable of proliferation. Quantification of CD34+ cells, evaluation of CD38 and c-kit molecules on these cells, as well as correlations of such factors as maternal age, gestational age, newborn sex and weight, umbilical cord length, placental weight with increased volume and concentration of immature cells, among others, were performed in 70 blood samples from term newborns. The mean volume of umbilical cord blood collected was 53.8±33.6 mL, where 30.96±18.9 CD34+/mL UCB cells were found, of which 16.66±8.32% were CD34+CD38- cells, and 47.23±24.0% were CD34+CD117cells. Newborn weight and placental weight were positively correlated with increased volume of collected UCB. The volume of collected blood was found to affect the absolute count of CD34+ cells and the relative value of these among total nucleated cells, as well as the percentage of CD34+CD117+ and CD34+CD117cells. CD34+ cells were positively correlated with leukocytes, and gestational age was negatively correlated with the number of CD34+ cells. Our results confirm the importance of the accurate quantification of CD34+ cells and their subsets, and that many factors may be related to the higher number of hematopoietic stem cells, which are crucial for successful transplantation.

Os aparelhos de automação em hematologia oferecem alta sensibilidade e precisão na realização do hemograma na rotina do laboratório de hematologia. Para avaliar os critérios de liberação dos hemogramas por interfaceamento direto entre os contadores eletrônicos e o setor de emissão dos laudos, foram examinadas 247 lâminas de hemogramas. Entre essas, 149 lâminas foram consideradas concordantes com os critérios de liberação por interfaceamento direto enquanto 98 foram consideradas não concordantes pelos contadores automatizados Sysmex SE 9500 e Cell Dyn 4000. Dentre os hemogramas concordantes, a microscopia sem acesso aos dados numéricos mostrou alteração em apenas uma lâmina, a qual era clinicamente irrelevante. Por outro lado, entre os 98 hemogramas não concordantes, 32 apresentavam alterações. Os dados encontrados comprovam a satisfatória sensibilidade dos sistemas de automação analisados. As lâminas dos hemogramas não concordantes foram reexaminadas, com o objetivo de avaliar os resultados eletrônicos. Esse fato permitiu a análise das causas das reprovações com sugestões para eventuais simplificações do sistema. O presente trabalho mostrou que os resultados emitidos pelos contadores automáticos analisados apresentam uma alta correlação com a avaliação microscópica. Conclui-se, portanto, que os resultados dos hemogramas liberados pelos aparelhos analisados são satisfatórios e estes aparelhos são confiáveis para a rotina no laboratório de hematologia.

Automated equipment used in the hematological laboratory for routine hemograms offers high sensitivity and great accuracy. In order to evaluate the liberation criteria of hemograms by direct interfacing between the electronic counters and the emission of results, 247 hemogram slides were examined. Of these using the Sysmex SE 9500 and Cell Dyn 4000 automated counters, 149 slides were considered concordant with liberation criteria by direct interfacing while 98 were considered non-concordant. Of the concordant hemograms, microscopy without access to the numeric results showed alterations in only one slide, which was considered clinically irrelevant. On the other hand, of the 98 non-concordant hemograms, 32 showed alterations. The results demonstrate the satisfactory sensitivity of the automatic systems analyzed. The slides with the non-concordant hemograms were re-examined, in order to evaluate the electronic results. Thus, it was possible to analyze the causes of the non-concordance and give suggestions for possible simplifications of the system. This study shows that the results emitted by the assessed automatic counters presented a high level of correlation with the microscopy count. Therefore, it can be concluded that the results of the hemograms liberated by the devices are satisfactory and that these devices are reliable for the routine use within the hematological laboratory.