Thyroid tissue analysis through Raman spectroscopy.

The diagnosis of thyroid pathologies is usually made by cytologic analysis of the fine needle aspiration (FNA) material. However, this procedure has a low sensitivity at times, presenting a variation of 2-37%. The application of optical spectroscopy in the characterization of alterations could result in the development of a minimally invasive and non-destructive method for the diagnosis of thyroid diseases. Thus, the objective of this work was to study the biochemical alterations of tissues and hormones (T3 and T4) of the thyroid gland by means of molecular vibrations probed by FT-Raman spectroscopy. Through the discriminative linear analysis of the Raman spectra of the tissue, it was possible to establish (in percentages) the correct classification index among the groups: goitre adjacent tissue, goitre nodular region, follicular adenoma, follicular carcinoma and papillary carcinoma. As a result of the comparison between the groups goitre adjacent tissue versus goitre nodular region, an index of 58.3% of correct classification was obtained; this percentage was considered low, and it was not possible to distinguish the Raman spectra of these groups. Between goitre (nodular region and adjacent tissue) versus papillary carcinoma, the index of correct classification was 64.9%, which was considered good. A relevant result was obtained in the analysis of the benign tissues (goitre and follicular adenoma) versus malignant tissues (papillary and follicular carcinomas), for which the index was 72.5% and considered good. It was also possible, by means of visual observation, to find similar vibrational modes in the hormones and pathologic tissues. In conclusion, some biochemical alterations, represented by the FT-Raman spectra, were identified that could possibly be used to classify histologic groups of the thyroid. However, more studies are necessary due to the difficulty in setting a standard for pathologic groups.

Heparanase-2, syndecan-1, and extracellular matrix remodeling in colorectal carcinoma.

AIM: To propose a quantitative method to detect heparanase-2 (HPA2) and syndecan-1 (Syn-1) using immunohistochemistry in colorectal (colon and rectal) carcinomas compared with nonneoplastic tissues and evaluate the possible role of these molecules in tumor development and extracellular remodeling. METHODS: Cytoplasmic staining of HPA2 and Syn-1 was obtained by standard immunohistochemical reactions in 50 colorectal carcinoma and 20 nonneoplastic large bowels tissues. An image system was used to quantify the immunoexpression by digital computer-assisted method (Matos et al. 2006). The cutoff point for the immunohistochemistry variable was defined by sensibility and specificity curves. Statistical analysis was performed using SPSS version 13.0. RESULTS: HPA2 was over-expressed in colorectal cancer (131.1+/-24.9 o.u./microm) when compared with nonneoplastic tissues (27.9+/-12.2 o.u./microm) (P<0.0001). However, an opposite correlation was observed between Syn-1 and tumor presence, where colorectal tissues expressed lower Syn-1 proteoglycan compared with nonneoplastic tissues, respectively (39.2+/-17.8 o.u./microm) and (102.2+/-25.2 o.u./microm) (P<0.0001). CONCLUSION: A methodology with high sensitivity and specificity is proposed with a cutoff value for HPA2 and Syn-1 in the immunohistochemistry assay to define the presence of tumor. It was demonstrated for the first time in the literature that HPA2 is over-expressed in colorectal carcinoma tissues compared with nonneoplastic tissues. HPA2 over-expression could be possibly related to Syn-1 shedding despite the fact that HPA2 does not present enzymatic activity as HPA1.