A non-destructive X-ray fluorescence method of analysis of formalin fixed-paraffin embedded biopsied samples for biomarkers for breast and colon cancer.

In this work we present a methodology for the non-destructive elemental determination of formalin-fixed paraffin-embedded (FFPE) human tissue samples based on the Fundamental Parameters method for the quantification of micro Energy Dispersive X Ray Fluorescence (micro-EDXRF) area scans. This methodology intended to overcome two major constraints in the analysis of paraffin embedded tissue samples - retrieval of optimal region of analysis of the tissue within the paraffin block and the determination of the dark matrix composition of the biopsied sample. This way, an image treatment algorithm, based on R® tool to select the regions of the micro-EDXRF area scans was developed. Also, different dark matrix compositions were evaluated using varying combinations of H, C, N and O until the most accurate matrix was found: 8% H, 15% C, 1% N and 60% O for breast FFPE samples and 8% H, 23% C, 2% N and 55% O for colon. The developed methodology was applied to paired normal-tumour samples of breast and colon biopsied tissues in order to gauge potential elemental biomarkers for carcinogenesis in these tissues. The obtained results showed distinctive biomarkers for breast and for colon: there was a significant increase of P, S, K and Fe in both tissues, while a significant increase of Ca an Zn concentrations was also determined for breast tumour samples.

Analysis of human tissues using Energy Dispersive X Ray Fluorescence - Dark matrix determination for the application to cancer research.

BACKGROUND: X ray Fluorescence has been essayed as a suitable technique for the elemental quantification of trace element in human tissues, namely comparison of normal and cancerous tissue. However, accurate results depend on a robust quantification approach, namely correct evaluation of the samples' dark matrix. METHODS: In order to determine the most suitable dark matrix composition for the quantification of such samples using the Fundamental Parameter approach, we have measured several Certified Reference Materials and essayed different dark matrix compositions to achieve the most accurate results. The resulting dark matrix was then applied to normal and tumor ovarian and prostate tissue samples, and the obtained results were compared with the ones obtained with a comparative method using external standard calibration curves. RESULTS: Using a dark matrix composed of 10 % - H, 22 % - C, 3 % - N and 60 % - O yielded the best compromise in accuracy for the light and heavy elements. For the reduced sample size and conditions of this study, for both organs, the concentrations of transition metals decrease in tumor tissues, while the concentration of lighter elements, P and Cl, increases. On the other hand, there are elements that showed different behavior between the two types of tissue, namely Zn and S, that increase in prostate tumor tissue and decrease in ovarian tissue. CONCLUSION: An increase in precision was one of the improvements found with the newly developed method, as the FP-approach contemplates matrix effects and the influence of other elements in the analytes' quantification. Additionally, the determined dark matrix can be employed in any tissue analysis application by means of EDXRF.

Advances in the pathogenesis representing definite outcomes in chronic urticaria.

PURPOSE OF REVIEW: We reviewed in this article, the recent advances in CSU physiopathology and potential clinical and laboratory biomarkers in CSU. RECENT FINDINGS: In addition to the central role of mast cells in urticaria physiopathology, increased interest in basophils has arisen. Recent data corroborate the autoimmunity pathway as one of the main pathways in mast cell activation. The association of inflammatory cytokines, heat shock proteins and staphylococcal infection with CSU are also reviewed. C-reactive protein, D-dimers, autologous serum skin test, IgE levels and FcεRI expression in basophils have shown their potential as biomarkers for disease duration, activity, severity and/or response to treatment. SUMMARY: A comprehensive understanding of chronic spontaneous urticaria mechanisms is essential to find novel biomarkers and treatments. The use of these biomarkers in clinical practice will guide us in choosing the best treatment option for our patients.