Comparative study by computed radiography, histology, and scanning electron microscopy of the articular cartilage of normal goats and in chronic infection with caprine arthritis-encephalitis virus

In the northeast of Brazil, caprine arthritis-encephalitis (CAE) is one of the key reasons for herd productivity decreasing that result in considerable economic losses. A comparative study was carried out using computed radiography (CR), histological analysis (HA), and scanning electronic microscopy (SEM) of the joints of CAE infected and normal goats. Humerus head surface of positive animals presented reduced joint space, increased bone density, and signs of degenerative joint disease (DJD). The carpal joint presented no morphological alterations in CR in any of the animals studied. Tarsus joint was the most affected, characterized by severe DJD, absence of joint space, increased periarticular soft tissue density, edema, and bone sclerosis. Histological analysis showed chronic tissue lesions, complete loss of the surface zone, absence of proteoglycans in the transition and radial zones and destruction of the cartilage surface in the CAE positive animals. Analysis by SEM showed ulcerated lesions with irregular and folded patterns on the joint surface that distinguished the limits between areas of normal and affected cartilage. The morphological study of the joints of normal and CAE positive goats deepened understanding of the alteration in the tissue bioarchitecture of the most affected joints. The SEM finding sustained previous histological reports, similar to those found for rheumatoid arthritis, suggesting that the goat infected with CAE can be considered as a potential model for research in this area.

Study of electron densities of normal and neoplastic human breast tissues by Compton scattering using synchrotron radiation

Electron densities of 33 samples of normal (adipose and fibroglangular) and neoplastic (benign and malignant) human breast tissues were determined through Compton scattering data using a mono-chromatic synchrotron radiation source and an energy dispersive detector. The area of Compton peaks was used to determine the electron densities of the samples. Adipose tissue exhibits the lowest values of electron density whereas malignant tissue the highest. The relationship with their histology was discussed. Comparison with previous results showed differences smaller than 4%. (C) 2012 Elsevier Ltd. All rights reserved.

Compton scattering spectrum as a source of information of normal and neoplastic breast tissues' composition

In this work we measured X-ray scatter spectra from normal and neoplastic breast tissues using photon energy of 17.44 key and a scattering angle of 90 degrees, in order to study the shape (FWHM) of the Compton peaks. The obtained results for FWHM were discussed in terms of composition and histological characteristics of each tissue type. The statistical analysis shows that the distribution of FWHM of normal adipose breast tissue clearly differs from all other investigated tissues. Comparison between experimental values of FWHM and effective atomic number revealed a strong correlation between them, showing that the FWHM values can be used to provide information about elemental composition of the tissues. (C) 2012 Elsevier Ltd. All rights reserved.

Influence of normal and radial contributions of local current density on local electrochemical impedance spectroscopy

A new tri-electrode probe is presented and applied to local electrochemical impedance spectroscopy (LEIS) measurements. As opposed to two-probe systems, the three-probe one allows measurement not only of normal, but also of radial contributions of local current densities to the local impedance values. The results concerning the cases of the blocking electrode and the electrode with faradaic reaction are discussed from the theoretical point of view for a disk electrode. Numerical simulations and experimental results are compared for the case of the ferri/ferrocyanide electrode reaction at the Pt working electrode disk. At the centre of the disk, the impedance taking into account both normal and radial contributions was in good agreement with the local impedance measured in terms of only the normal contribution. At the periphery of the electrode, the impedance taking into account both normal and radial contributions differed significantly from the local impedance measured in terms of only the normal contribution. The radial impedance results at the periphery of the electrode are in good agreement with the usual explanation that the associated larger current density is attributed to the geometry of the electrode, which exhibits a greater accessibility at the electrode edge. (C) 2011 Elsevier Ltd. All rights reserved.