Infrared spectra of thyroid tumor tissues

Abstract

543.422.4 We used infrared spectroscopy methods to study thyroid tumor tissues removed during surgery. The IR spectra of the surgical material are compared with data from histological examination. We show that in malignant neoplasms, the spectra of proteins in the region of C=O vibrations are different from the spectra of these substances in benign tumors and in tissues outside the pathological focus at a distance >1 cm from the margin of the tumor. The differences in the spectra are due to changes in the supermolecular structure of the proteins, resulting from rearrangement of the system of hydrogen bonds. We identify the spectral signs of malignant pathologies. Introduction.A steady trend of increasing malignant neoplasms has been observed worldwide. A rather high level of increase in cancers of such a specialized endocrine organ as the thyroid gland has been identified in the Republic of Belarus, compared with other human organs [1]. Accordingly, diagnosis, treatment, and prevention of thyroid cancers are urgent problems in modern medicine.Diagnosis of malignant neoplasms is the most complicated part of oncology, since tumors are far from always clinically apparent as specific symptoms, especially in the early stages [2]. Since the underlying life processes are realized at the molecular level, a promising approach to studying thyroid cancer problems is to use methods which study organ pathology at the level of molecular structure and molecular interactions. Recently, owing to the high sensitivity and information content of IR spectroscopy methods relative to structural changes and the composition of molecules, attempts have been made to use such methods in biomedicine, in particular oncology [3][4][5][6][7]. It is assumed that IR spectroscopy methods are potentially capable of identifying signs which can be used to distinguish between a malignant tumor and other focal changes in human tissues and organs at the molecular interaction level [4]. In order to identify the spectral signs of malignancy in the thyroid gland, in this work we have studied the IR spectra of tumorous formations removed during surgery.Materials and Methods. The materials for the study were fragments of thyroid tissue removed during surgery. In addition to proteins, the tissues included water, polycarbohydrates, lipids, hormones, biosynthesis and decomposition products entering the bloodstream and also drugs given to the patients the day before and during the surgeries. These components, along with the proteins, can absorb IR radiation. We need to minimize the effect of the components listed above on the IR spectra of the proteins. This was achieved by satisfying specific conditions for preparing the samples for the spectroscopic measurements.With the aim of eliminating residues of blood and water-soluble components, the tissue fragments were washed repeatedly with distilled water; to remove lipids and other organic substances of non-protein origin, the samples were placed in CCl 4 for 2 h. After extraction, the tissue fragments were pl...

Optical Diagnosis for Thyroid and Parathyroid Tissues—A Review

“…Infrared spectroscopy methods are potentially capable of identifying signs to distinguish malignant tumors and other focal changes in tissue because it has high sensitivity and the ability to retrieve information relative to structural changes and composition of molecules. Consequently, it is possible to study thyroid pathology at the level of the molecular structure and molecular interactions using IR spectroscopy (14)(15)(16)(17).…”

“…Toltorozhev et al (15) used infrared spectroscopy on fragments of thyroid tissue to study thyroid tumors. By using Fourier deconvolution mathematical method to analyze the spectra, they compared benign and malignant tumors and observed changes in the IR spectra of the tumors in the region of N-H and CDO vibrations.…”

“…This article focuses primarily on the use of fluorescence spectroscopy (4-6), time-resolved fluorescence (7,8), near-infrared spectroscopy (9-11), Raman spectroscopy (12,13), infrared spectroscopy (14)(15)(16)(17), elastic scattering spectroscopy (18,19), second-harmonic generation (SHG) microscopy (20,21), and optical coherence tomography (22)(23)(24) to evaluate thyroid and parathyroid tissues.…”

IR Spectroscopic signs of malignant neoplasms in the thyroid gland

“…The largest contribution to this absorption band comes from stretching vibrations of N-H groups in peptide chains of the protein macromolecules [3][4][5][6]. The intense absorption band in the 1700-1600 cm -1 interval is due to stretching vibrations of the C=O groups of the peptide chains [3][4][5][6]8]. These two absorption bands are present in the IR spectra of all the studied thyroid tissues (curves 1-3).…”

“…These two absorption bands are present in the IR spectra of all the studied thyroid tissues (curves 1-3). We know that the spectral characteristics of these bands are sensitive to very small changes in the geometry of the protein molecules, and also to the development of hydrogen bonds between peptide groups or changes in such bonds [6,8].…”