Takeshi Moriguchi

Elucidation of adsorption mechanism of bone-staining agent alizarin red S on hydroxyapatite by FT-IR microspectroscopy

To elucidate adsorption mechanism of alizarin red S (ARS), which is often used for staining bones in histology, adsorption of ARS on hydroxyapatite, Ca10(PO4)6(OH)2 (HAP), was investigated by a batch method, compared with alizarin, phenols, and benzenesulfonates. We found that ionized 1-, 2-OH groups (1-, 2-O(-)) of ARS can be electrostatically bound to Ca2+ on HAP, but that the 3-SO3(-) group of ARS hardly participates in adsorption on HAP. ARS-adsorbed HAP (ARS-HAP) in dark reddish violet was also prepared and analyzed by FT-IR microspectroscopy to gain structural information on bonding between ARS and HAP. The obtained spectrum, which was converted to difference spectra, indicated a single band of nu(C=O) at 1627 cm(-1) and two types of symmetric C=O stretching bands of nu(s)(C=O) + nu(C=C) at 1345 cm(-1) and nu(s)(C=O) + delta(O-C=C) at 1272 cm(-1). These bands imply the existence of a salt form in ARS-HAP via 1-, 2-OH groups of ARS. As a result of the existence of a chelate form in ARS-HAP via 1-OH and 9-C=O groups of ARS, two bands of nu(C=C) + nu(C=O) at 1572 cm(-1) and nu(C=O) + nu(C=C) at 1537 cm(-1) were also observed. In addition, ARS was almost desorbed from colored ARS-HAP at 50 degrees C by using neutral phosphate buffer to recover slightly pale pinkish HAP, or De-ARS-HAP. The desorbed ARS belongs to ARS previously adsorbed on HAP by salt formation, while the remaining color on De-ARS-HAP indicates ARS still adsorbed on HAP by chelate formation. Consequently, we elucidated two adsorption mechanisms of ARS on HAP: The major adsorption is salt formation made up with 1-, 2-O(-) of ARS and Ca2+ on HAP, and the minor adsorption is chelate formation made up with 1-O(-) and 9-C=O of ARS and Ca2+ on HAP.

Evaluation of glycogen level in human lung carcinoma tissues by an infrared spectroscopic method

Glycogen levels in the tissue samples obtained from carcinomas and normal sections of human lungs (26 patients) were studied by measuring the infrared band intensity at 1045 cm(-1) due to glycogen. As an internal standard peak, the band at 1545 cm(-1) (amide II) was chosen, and the ratios of these band areas (A1045/A1545) were compared with histological classification and differentiation of tumors. The glycogen level in the carcinoma tissues was significantly higher than that in the normal tissues (P < 0.01, n = 26). Further, the ratio of amounts of glycogen in the carcinomas and in the normal tissues for adenocarcinoma was higher than that for squamous cell carcinoma (P < 0.01). The increased degree of differentiation of the squamous cell carcinomas appeared to be correlated with an increase in the glycogen level. These results suggest that comparison of glycogen levels in the tumor and normal section of human lung may be used as a differentiating parameter for abnormality and histological classification of tumors. The present Fourier transform-infrared spectroscopy (FT-IR) method may become of wide application for studying various tissue samples.

Effect of Repeated Application of C60 Combined with UVA Radiation Onto Hairless Mouse Back Skin

Abstract Repeated application of buckminsterfullerene (C60) toluene solution combined with ultraviolet A (UVA) radiation onto hairless mouse back skin resulted in enhancing formation of erythema as an acute disease but induced no carcinoma on the skin. This result is probably due to insolubility of C60 in the living cells to generate little singlet oxygen 1O2 by UVA radiation.

Determination of Glycogen Levels in Human Lung Cancer and Normal Tissues by Fourier Transform Infrared Spectrometry

Glycogen levels in the carcinoma and normal tissues of human lungs were studied by the FT-IR method using the integrated area ratios of glycogen to protein (A1045/A1545). Further amounts of glycogen and protein contained in the same tissues were measured by an anthrone method and by using a dotMETRIC™ kit, respectively. Ratios of glycogen to protein obtained here were compared with the FT-IR spectroscopic data in relation to abnormality and histological classification of the tumors indicating a good correlation between them. The present results show that the FT-IR method is very reliable and that may be of wide application for studying glycogen levels in various tissues as well as diagnosis purpose.