Characterization of the physical and mechanical properties of femoral bone defects filled with polyanionic collagen scaffolds in ovariectomized rats

The aim of this study was to evaluate the effect of scaffolds native or polyanionic collagen matrix (submitted to alkaline treatment for 48 or 96 hours, PCM48 or PCM96, respectively) on the repair of osteoporosis bone fractures resulting from the gonadal hormone alterations caused by ovariectomy in rats undergoing hormone replacement therapy. The physical and mechanical characteristics of bone were analyzed. Macroscopic analysis revealed the absence of pathological alterations in the implanted areas. The percent mineral matter and bone mineral density of the femurs were lower in ovariectomized rats. The mechanical strength of newly formed bone was greater in the area receiving the PCM96 scaffolds compared to the area implanted with the native scaffolds. The PCM96 scaffold is the best choice for bone repair in animals with hormone deficiency since it promotes faster bone growth and good mechanical strength.23924

Avaliação do possível efeito tóxico de um alcano semifluorinado de uso oftalmológico sobre cultura de células Vero Assessment of the possible toxic effect of a semifluorinated alkane on Vero cell culture

OBJETIVOS: Perfluorocarbonos líquidos (PFCLs) são usados em cirurgias oftalmológicas de vítreo-retina. Os PFCLs podem causar reações inflamatórias, danos celulares e destruição da arquitetura normal da retina. Na tentativa de se evitar estes efeitos, foram desenvolvidos os alcanos semifluorinados (ASF). Este trabalho avaliou o uso potencial de um ASF, o perfluorohexiloctano (F6H8), como substituto do vítreo de longo prazo em condições controladas por meio de cultura celular. MÉTODOS: Foi feita análise da citotoxicidade indireta, na qual as células entram em contato apenas com elementos solúveis que pudessem ser eliminados pelo perfluorohexiloctano. Avaliou-se então a toxicidade direta, ou seja, a toxicidade mediada pelo contato, do perfluorohexiloctano por meio de microscopia eletrônica de varredura e a imunocitoquímica para a actina. Utilizou-se como controle, células em meio de cultura livre de qualquer tratamento, um controle positivo para toxicidade, que apresenta comprovado efeito tóxico às células, e um controle de peso que exercesse compressão mecânica similar à quantidade de perfluorohexiloctano utilizada no experimento. RESULTADO: Observou-se que o referido produto não apresenta toxicidade indireta. Os ensaios de toxicidade direta mostraram que as alterações celulares promovidas pelo perfluorohexiloctano eram similares àquelas exercidas pelo controle de peso e distintas do controle de toxicidade. CONCLUSÕES: O perfluorohexiloctano não apresenta toxicidade indireta e tem efeito mais compressivo do que tóxico sobre as células em cultura.<br>PURPOSE: Perfluorocarbon liquids (PFCLs) are used in vitreoretinal surgery. PFCLs may cause inflammatory reactions, cellular injury and destruction of the normal retinal architecture. In order to avoid these effects, semifluorinated alkanes (SFA) were developed. We assessed the potential use of an SFA known as perfluorohexiloctano (F6H8) as long-term vitreous replacement under controlled cell culture conditions. METHODS: We analyzed indirect cytotoxicity, where the cells only come into contact with soluble elements that can be eliminated by perfluorohexiloctano. We therefore analyzed direct toxicity (contact toxicity) of perfluorohexiloctano by means of scanning electronic microscopy and immunocytochemistry reagents for actin. Cells embedded in a treatment-free culture medium were used as control, a positive control for toxicity with an undeniably toxic effect on cells, and a weight control that produced a mechanical compression similar to the amount of perfluorohexiloctano used in the experiment. RESULTS: The indirect cytotoxicity test showed that F6H8 did not affect cell growth. Our direct toxicity tests showed that cellular alterations caused by perfluorohexiloctano were similar to those produced by the weight control and different from toxicity control. CONCLUSION: Perfluorohexiloctano does not present indirect toxicity and this product has a compressive rather than a toxic effect on cultured cells

Morphological And Growth Alterations In Vero Cells Transformed By Cisplatin.

Cisplatin is an antineoplastic agent used to treat solid tumours, such as ovarian, testicular and bladder tumours. However, studies in vitro and in vivo have shown that cisplatin is mutagenic, genotoxic and tumorigenic in other tissues and organs. In this work, we examined the effect of cisplatin on Vero cells, a fibroblast-like cell line. The morphological characteristics were investigated using phase contrast microscopy, scanning electron microscopy and the actin cytoskeleton was labelled with fluorescein isothiocyanate-phalloidin. Cell proliferation was assessed based on the growth curve. Cultured Vero cells treated with cisplatin showed behavioural and morphological alterations associated with cellular transformation. The transformed cells grew in multilayers and formed cellular aggregates. The proliferation and morphological characteristics of the transformed cells were very different from those of control ones. Since transformed Vero cells showed several characteristics related to neoplastic growth, these cells could be a useful model for studying tumour cells in vitro.30485-9

Light microscope observation of circulating human lymphocytes cultured in vitro

The purpose of this work was to study the isolation and a light microscopy technique for cultured lymphocytes. Blood samples were obtained by venipuncture with an anticoagulant added and centrifuged in a Percoll density gradient to separate the leukocytes. Lymphocytes were placed in 25 cm ³ tissue culture flasks at 37ºC. After culturing, they were fixed and stained with the methods used for blood smears. Results showed that not all fixing solutions and stains were an equally good choice for cultured lymphocytes.<br>Os linfócitos são células importantes do sistema imune e têm sido largamente utilizados em estudos morfológicos. Entretanto, a literatura sobre técnicas de preparação dessas células é escassa e antiga, especialmente para linfócitos cultivados in vitro. Portanto, o objetivo desse estudo foi relatar com detalhes as técnicas de isolamento e microscopia de luz de linfócitos mantidos em cultura. Amostras de sangue foram obtidas por punção venosa e centrifugadas em gradiente de densidade de Percoll, para separar os leucócitos. Os linfócitos foram mantidos em frascos de cultura de 25 cm³ a 37ºC. Após a cultura, as células foram fixadas e coradas de acordo com a metodologia utilizada para esfregaços sanguíneos. Nossos resultados mostraram que nem todos os fixadores e corantes utilizados para esfregaços sanguíneos são uma boa escolha para linfócitos cultivados in vitro