RET mutation and increased angiogenesis in medullary thyroid carcinomas

Advanced medullary thyroid cancers (MTCs) are now being treated with drugs that inhibit receptor tyrosine kinases, many of which involved in angiogenesis. Response rates vary widely, and toxic effects are common, so treatment should be reserved for MTCs likely to be responsive to these drugs. RET mutations are common in MTCs, but it is unclear how they influence the microvascularization of these tumors. We examined 45 MTCs with germ-line or somatic RET mutations (RETmut group) and 34 with wild-type RET (RETwt). Taqman Low-Density Arrays were used to assess proangiogenic gene expression. Immunohistochemistry was used to assess intratumoral, peritumoral and nontumoral expression levels of VEGFR1, R2, R3, PDGFRa, PDGFB and NOTCH3. We also assessed microvessel density (MVD) and lymphatic vessel density (LVD) based on CD31-positive and podoplanin-positive vessel counts, respectively, and vascular pericyte density based on staining for a-smooth muscle actin (a-SMA), a pericyte marker. Compared with RETwt tumors, RETmut tumors exhibited upregulated expression of proangiogenic genes (mRNA and protein), especially VEGFR1, PDGFB and NOTCH3. MVDs and LVDs were similar in the two groups. However, microvessels in RETmut tumors were more likely to be a-SMA positive, indicating enhanced coverage by pericytes, which play key roles in vessel sprouting, maturation and stabilization. These data suggest that angiogenesis in RETmut MTCs may be more intense and complete than that found in RETwt tumors, a feature that might increase their susceptibility to antiangiogenic therapy. Given their increased vascular pericyte density, RETmut MTCs might also benefit from combined or preliminary treatment with PDGF inhibitors

Non-Functional Jaw Muscular Activity in Patients with Disorders of Consciousness Revealed by A Long-Lasting Polygraphy

The presence of involuntary, non-functional jaw muscle activity (NFJMA) has not yet been assessed in patients with disorders of consciousness (DOC), although the presence of bruxism and other forms of movement disorders involving facial muscles is probably more frequent than believed. In this work, we evaluated twenty-two prolonged or chronic DOC patients with a long-lasting polygraphic recording to verify NFJMA occurrence and assess its neurophysiological patterns in this group of patients. A total of 5 out of 22 patients showed the presence of significant NFJMA with electromyographic patterns similar to what can be observed in non-DOC patients with bruxism, thus suggesting a disinhibition of masticatory motor nuclei from the cortical control. On the other hand, in two DOC patients, electromyographic patterns advised for the presence of myorhythmia, thus suggesting a brainstem/diencephalic involvement. Functional, non-invasive tools such as long-lasting polygraphic recordings should be extended to a larger sample of patients, since they are increasingly important in revealing disorders potentially severe and impacting the quality of life of DOC patients

Teor de óleo de alho em cápsulas gelatinosas por espectroscopia no infravermelho médio e técnicas quimiométricas

Garlic oil, in the form of gelatin capsules, contains various substances considered beneficial to health, which act to lower cholesterol and blood pressure, in the treatment of flu and diabetes, and to prevent the development of tumors and cardiovascular diseases. However, disagreements over its functionality have been reported and, one possible reason is the lack of standardization of these products. Considering that there is no established legislation on the quality control of garlic oil, commercialized in capsules, it is important to develop simple and fast methods for the analysis of these products. In this work, we propose screening and quantification analysis methods, using attenuated total reflectance (ATR) spectroscopy and chemometric methods for the classification and quantification of garlic oil capsules as a function of their concentrations. The Successive Projections Algorithm (SPA), together with Linear Discriminant Analysis (LDA), obtained the best results of classifying capsules in three classes, using models constructed using only the selected variable 924 cm-1, where the existing band is assigned to stretching vibrations of C-S-C and deformation of =CH2, present in the major constituents of garlic oil. For the 136 capsules tested, we obtained a rate of 88.2% of agreement with the information contained in their labels. In the quantification of the garlic oil content of the capsules, the MCR-ALS (Multivariate Curve Resolution with Alternating Least Squares) method, using a column wise configuration, was able to solve the mixtures, recovering the spectra of garlic and soybean oil with correlations of 0.8914 and 0.9997, respectively. As a result, MCR-ALS obtained a lack of fit of 3.63% and explained variance of 99.87%, limits of detection and quantification equals to 0,09% and 0,27%, respectively, RPD (Residual Prediction Deviation) equal to 8,89 and the recovery trials provided indexes of 98% to 99%, indicating good accuracy of the method. As in the classification, the concentrations predicted for some brands of capsules, proved to be in disagreement with the values declared on their labels, including between different batches of the same brand. In this way, it is justified the need of control of the inspection organs with the manufacturers, to guarantee the quality of these products. The results presented suggest that the proposed methods are effective in investigating gelatinous capsules of garlic oil as to their content.Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco - FACEPEO óleo de alho, comercializado na forma de cápsulas gelatinosas, contém diversas substâncias consideradas benéficas à saúde, que atuam na redução do colesterol e da pressão arterial, no tratamento de gripe e diabetes e na prevenção do desenvolvimento de tumores e doenças cardiovasculares. Entretanto, divergências a respeito de sua funcionalidade tem sido relatadas e, uma possível causa, é a falta de padronização desses produtos. Considerando que não há legislação estabelecida quanto ao controle de qualidade do óleo de alho, comercializado em cápsulas, reveste-se de importância o desenvolvimento de métodos simples e rápidos para a análise desses produtos. Neste trabalho, propõe-se métodos de análise screening e de quantificação, utilizando espectroscopia na região do infravermelho médio por reflectância total atenuada (ATR) e métodos quimiométricos, para a classificação e quantificação de cápsulas de óleo de alho em função de suas concentrações. O Algoritmo das Projeções Sucessivas (SPA) aliado à Análise Discriminante Linear (LDA), obteve os melhores resultados de classificação das cápsulas em três classes, por meio de modelos construídos utilizando apenas a variável selecionada 924 cm-1, onde a banda existente é atribuída a vibrações de estiramento de C-S-C e deformação de =CH2, presentes nos constituintes majoritários do óleo de alho. Para as 136 cápsulas testadas, obteve-se uma taxa de 88,2% de concordância com as informações contidas em seus rótulos. Na quantificação do teor de óleo de alho das cápsulas, o método MCR-ALS (Resolução de Curvas Multivariadas com Mínimos Quadrados Alternantes), empregando configuração aumentada na direção das colunas (column wise), mostrou-se capaz de resolver as misturas, recuperando os espectros de óleo de alho e de soja com correlações de 0,8914 e 0,9997, respectivamente. Como resultado, MCR-ALS obteve falta de ajuste de 3,63% e variância explicada de 99,87%, limites de detecção e de quantificação iguais a 0,09% e 0,27%, respectivamente, RPD (Relação de Desempenho do Desvio) igual a 8,89 e os ensaios de recuperação forneceram índices de 98% a 99%, indicando boa exatidão do método. Assim como na classificação, as concentrações previstas para algumas marcas de cápsulas, revelaram-se em discordância com os valores declarados em seus rótulos, inclusive entre diferentes lotes da mesma marca. Deste modo, justifica-se a necessidade de controle dos órgãos de fiscalização junto aos fabricantes, para garantir a qualidade desses produtos. Os resultados apresentados sugerem que os métodos propostos são eficazes para investigar cápsulas gelatinosas de óleo de alho quanto ao seu teor

Estudo comparativo sobre filtragem de sinais instrumentais usando transformadas de Fourier e Wavelet

A comparative study of the Fourier (FT) and the wavelet transforms (WT) for instrumental signal denoising is presented. The basic principles of wavelet theory are described in a succinct and simplified manner. For illustration, FT and WT are used to filter UV-VIS and plasma emission spectra using MATLAB software for computation. Results show that FT and WT filters are comparable when the signal does not display sharp peaks (UV-VIS spectra), but the WT yields a better filtering when the filling factor of the signal is small (plasma spectra), since it causes low peak distortion

Simultaneous spectrometric determination of Cu2+, Mn2+ and Zn2+ in polivitaminic/polimineral drug using SPA and GA algorithms for variable selection

The application of the method for the simultaneous spectrophotometric determination of the divalent ions of copper, manganese and zinc for analysis of a pharmaceutical formulation of polivitaminic/polimineral is reported. This method uses 4-(2-pyridylazo) resorcinol (PAR) and multivariate calibration and was optimized using the successive projections algorithm (SPA) and a genetic algorithm (GA) for choosing the best series of wavelengths for analysis. Thus the construction of calibration models based on multiple linear regression (MLR-SPA and MLR-GA respectively) was made possible. The results obtained were compared with models based on latent variables, principal component regression (PCR) and partial least square regression (PLS) through the criterion of the root mean square error of prediction (RMSEP). All the methods presented even performance but the RLM methods are simpler since they require a smaller number of wavelengths and are easier to interpret than those based on latent variables

Flow-batch analyser for preparation of calibration standard mixtures in simultaneous multicomponent spectrometric analysis

The application of multivariate calibration techniques to multicomponent analysis by UV-VIS molecular absorption spectrometry is a powerful tool for simultaneous determination of several chemical species. However, when this methodology is accomplished manually, it is slow and laborious, consumes high amounts of reagents and samples, is susceptible to contaminations and presents a high operational cost. To overcome these drawbacks, a flow-batch analyser is proposed in this work. This analyser was developed for automatic preparation of standard calibration and test (or validation) mixtures. It was applied to the simultaneous determination of Cu2+, Mn2+ and Zn2+ in polyvitaminic and polymineral pharmaceutical formulations, using 4-(2-piridilazo) resorcinol as reagent and a UV-VIS spectrophotometer with a photodiode array detector. The results obtained with the proposed system are in good agreement with those obtained by flame atomic absorption spectrometry, which was employed as reference method. With the proposed analyser, the preparation of calibration and test mixtures can be accomplished about four hours, while the manual procedure requires at least two days. Moreover, it consumes smaller amounts of reagents and samples than the manual procedure. After the preparation of calibration and test mixtures, 60 samples-1 can be carried out with the proposed flow-batch analyser