Vimentin expression and the influence of Matrigel in cell lines of head and neck squamous cell carcinoma

Vimentin is a cytoeskeletal intermediate filament protein commonly observed in mesenchymal cells; however, it can also be found in malignant epithelial cells. It is demonstrated in several carcinomas, such as those of the cervix, breast and bladder, in which it is widely used as a marker of the epithelial to mesenchymal transition that takes place during embryogenesis and metastasis. Vimentin is associated with tumors that show a high degree of invasiveness, being detected in invasion front cells. Its expression seems to be influenced by the tumor microenvironment. The aim of this study was to evaluate vimentin expression in head and neck squamous cell carcinoma (HNSCC) cell lines, and to investigate the contribution of the microenvironment to its expression. HNSCC cell lines (HN6, HN30 and HN31) and an immortalized nontumorigenic cell line (HaCaT) were submitted to a three-dimensional assay with Matrigel. Cytoplasmatic staining of the HN6 cell line cultured without Matrigel and of the HN30 and HN31 cell lines cultured with Matrigel was demonstrated through immunohistochemistry. Western Blotting revealed a significant decrease in vimentin expression for the HN6 cell line and a significant increase for the HN30 and HN31 cell lines cultured with Matrigel. The results suggest that vimentin can be expressed in HNSCC cells and its presence is influenced by the microenvironment of a tumor

An in vitro study showing the three-dimensional microenvironment influence over the behavior of head and neck squamous cell carcinoma

Objectives: The Head and Neck Squamous Cell Carcinoma (HNSCC) ranks sixth worldwide. The mechanisms of growth, invasion and metastasis of this pathology are extensively studied and generally related to specific variations in signaling pathways like the PI3K-Akt; however most of these competent studies have been performed bidimensionally, which may hide important questions. This study sought to analyze the influence of the microenvironment upon the behavior of HNSCC. Study Design: The status of pAkt, NF-?B and Cyclin D1 proteins was accessed through immunofluorescence and western blot methods in HNSCC cell lines originating from tongue, pharynx and metastatic lymph node when submitted to a three-dimensional culture model utilizing a matrix system. A bidimensional culture model (monolayer) was used as control. Results: The HNSCC cell lines cultured three-dimensionally exhibited a growth pattern characterized by small isolated islands, different from the control group. When the three-dimensional model was applied, two of the studied cell lines showed the same expression pattern as the bidimensional model regarding nuclear or cytoplasmatic localization, as well as reduction of all protein levels; however, the cell line originated from tongue, which specially has the epidermal growth factor receptor constitutively activated, demonstrated nuclear translocation of pAkt and also an increase in the levels of Cyclin D1. Conclusions: The results suggest the influence of the microenvironment upon the behavior of HNSCC cells due to the changed expression of proteins related to tumor growth and cellular invasion. Furthermore, intrinsically genetic conditions also played important roles over the cells, despite the culture model employed

Modelo de simulação de secagem de produtos agrícolas usando entalpia do ar constante Drying simulation model of agricultural products with constant air enthalpy

A simulação matemática de secagem de produtos agrícolas teve seu auge nas décadas de 1960 e 1970, com destaque para os modelos de Thompson e de Michigan. Entretanto, nenhum deles abordou a condição de entalpia constante do ar de secagem durante o processo, limitando-se a conferir se a umidade relativa do ar não excedia 100%. Estudos conduzidos na Universidade Estadual de Maringá permitiram concluir que os balanços de energia e de massa de um processo de secagem estão incluídos no uso da mesma entalpia do ar durante a secagem, ajustando-se, com ela, a umidade absoluta do ar em função da umidade removida do produto. Com essa nova razão da mistura do ar e com a entalpia constante, avalia-se a nova temperatura do ar de secagem na saída da camada e, com essas duas propriedades psicrométricas, a umidade relativa do ar. Se ela atingir a condição saturada, encerra-se o processo de secagem naquele tempo, a partir daquela posição. Os resultados obtidos por simulação foram conferidos com resultados experimentais de secagem de milho em camadas fixas, com elevada concordância entre eles.Mathematical drying simulation of agricultural products reached its highest point in the decades of 1960 and 1970, with prominence for MSU and Thompson's models. However, none of them used the constant enthalpy condition of drying air during the process, being limited to checking if the relative humidity of the air did not exceed 100%. Studies conducted in the State University of Maringá allowed to conclude that energy and mass balances of a drying process are included when using the same air enthalpy in such process. The absolute humidity of the air is adjusted as a function of the removed humidity of the product. With that new absolute humidity of the air and with the constant enthalpy, the new temperature of the drying air is evaluated in the exit of the layer and, with those two psychrometric properties, the relative humidity of the air. If it reaches the saturated condition, the drying process is stopped at that time and position. The results obtained by simulation were checked against experimental results of corn dried in fixed-bed layers, with high agreement among them

<b>Fixed-bed drying simulation with constant enthalpy, using the improved Michigan State University model</b> - doi: 10.4025/actascitechnol.v34i2.7812

<p>Drying of agricultural products at high temperatures can be simulated by mathematical models, which intend to describe the drying process close to commercial patterns. They are based on simultaneous heat and mass transfer between the product that is losing moisture, and the air that is supplying energy to the process. All models use these balances, never allowing values of relative humidity of the air to be greater than 100%. However, it has not been common to evaluate air enthalpy, which should not have significant variation during the entire process, accepted as adiabatic. In this work, a mathematical model is proposed for fixed-bed corn (<em>Zea mays</em> L.) drying simulation, according to the Michigan State University (MSU) model. In the numerical solution, the enthalpy of the drying air was maintained constant as a quantitative physical indicator for correction of the heat and mass exchange in each step of the process, in order to obtain more real evaluations in all drying stages, and in the results for final moisture of the grain. As a result, greater space and time intervals for the simulation were possible. The simulation was validated by comparisons with literature results.<strong> </strong></p><p> </p

Myoepithelioma of the Soft Palate: a Case Report Giving Special Attention to the Differential Diagnosis

Background: Myoepitheliomas are rare tumours that may generally arise from the minor or major salivary glands. The differential diagnosis of this tumour should be performed along with several benign and malignant soft tissue neoplasms. The present case report describes an asymptomatic mass that arose in the soft palate of 42 year old black woman with duration of the six months.Methods: An incisional biopsy of soft palate lesion was carried out and submitted for histological evaluation under the clinical hypothesis of salivary gland tumour. To confirm the myoepithelial nature of neoplastic cells the immunohistochemical reactions for smooth-muscle actin, cytokeratins and S100 were performed.Results: The histological examination revealed the presence of tumour originating from a minor salivary gland and covered by a stratified squamous oral epithelium. The tumour cells were arranged in order to form a myxoid pattern and, individually, small and/or medium spindle-shaped cells with predominantly round or ovoid nuclei, as well as epithelioid and plasmocytoid cells were noted. The stroma was myxomatous and no ductal or syringomatous epithelial structures were observed. Following the histological and immunohistochemical diagnosis of myoepithelioma, the lesion was surgically removed. After the surgery, a follow-up of one year showed no signs and symptoms of reccurrence.Conclusions: The myoepithelioma should be carefully distinguished from the other soft tissue tumours, especially those arising from salivary glands, such as pleomorphic adenoma and adenoid-cystic carcinoma