Investigation of Paraffin-embedded Basal Cell Carcinoma Using Electron Paramagnetic Resonance

Abstract

Basal cell carcinoma (BCC) in paraffin-embedded specimens was investigated by nondestructively electron paramagnetic resonance (EPR) and X-band (9.45 GHz) EPR imaging (EPRI). A histopathological examination of specimens showed the melanin contents and revealed that they were predominantly of the nodular types. A single-line EPR pattern was observed in the BCC specimens, and the spectra of the samples were analyzed using linewidth and spectral pattern parameters. The eumelanin-related radical was observed in paraffin-embedded BCC specimens. The stability of the radical was supported by sepia pigment experiments. The g-value and peak-to-peak linewidths (ΔHpp) were 2.0046 and 0.61 ± 0.02 mT (mean ± SEM), respectively. Strong EPRI signals correspond to areas of strong pigmentation in the samples. Thus, histopathological examination, EPR, and EPRI of BCC specimens showed that the radical distribution reflects on the spatial distribution of pigments in the samples.

X-band EPR Spectroscopic Investigation of Seborrheic Keratosis

“…Notably, a paraffin sample containing no tissue was also measured, and no signal was observed. Based on a single line, ΔHpp (0.58), g-value (2.004), and the previous data, 8,10 the radical is the eumelaninrelated radical. In addition, pigmented SK was suggested to contain melanin.…”

“…Note that a nonpigmented tissue (control) shows no recognizable EPR signal, as we reported. 10 In addition, we measured the permeability of the paraffinembedded SK samples; the values are listed in Table 1. We found that there is a reasonable correlation between the EPR intensity and the permeability, which is directly related to the sample color tone.…”

“…Several studies have used this method to investigate free radicals in naturally occurring samples. 3,5,[8][9][10] The application of noninvasive two-dimensional (2D) EPRI and EPR spectroscopy may provide detailed information regarding the location and concentration of paramagnetic species in relation to various disease states. Therefore, further EPR investigation could lead to the development of useful analytical tools for analyzing tumors and non-tumors.…”

Nondestructive Evaluations of Melanin-related Compounds in the Skin Using Electron Paramagnetic Resonance and Permeability Measurements

“…[5][6][7] Melanin (eumelanin) radicals in biomedical samples have been studied using the EPR technique in various ways, such as using paraffin-embedded human MM and human and basal cell carcinoma (BCC) specimens. 8 Melanin radicals in MM and nevus pigmentosus (NP) specimens have also been compared using EPR. 5 However, melanin radicals in paraffin-embedded various specimens at ambient temperatures have not been characterized using permeability value.…”

“…Recently, melanin (mostly eumelanin) has been extensively studied; in several studies, melanin radicals in naturally occurring melanin radicals were detected using EPR. 5,7,8 However, research on pheomelanin and its radical is limited. Pheomelanin is photosensitive and is decomposed by light, such as UV.…”