Microimaging FT-IR of head and neck tumors. V. Odontogenic cystic lesions

This study has been undertaken to investigate spectral features of cystic lesions of the jaw with the aim to understand their tumoral progression and to evidence initial signals of neoplastic changes.Three important groups (according to the World Health Organization classification) representing inflammatory (radicular) and developmental (orthokeratinized odontogenic, OOC) cysts as well as keratocystic odontogenic tumor (KCOT) of the jaw have been studied by microimaging infrared spectroscopy. From the spectral data analysed with the multivariate pattern recognition procedure, representative spectra were isolated and used to build correlation maps to localize the biochemical components in the tissue.The procedure enabled to better understand spectral features of these classes of cysts and to discriminate tumoral from non-tumoral spectra through the analysis of ‘vibrational markers’. In KCOT, the correlation of calcium derivatives (in metaplastic or displastic bones) with the tumor has been highlighted, too. The distribution of various biochemical components in the tissues, achieved through correlation maps of representative spectra, resulted in satisfactory agreement with the histopathological analysis. ‘Spectral isolation’ of micro tumorigenic zones in some normal OOC cysts, demonstrated the potentiality of infrared spectroscopy to evidence the early stage of a hidden lesion.     

Methacrylic Polymers Bearing in the Side-Chain an Optically Active Moiety Linked to the trans-4-Azobenzene Chromophore: Chiroptical Properties of Poly[(S)-(+)-N-methyl-(2-methacryloyloxypropanoyl)-4-aminoazobenzene]

The synthesis by radical homopolymerization of a novel optically active methacrylic polymer containing a side-chain chiral moiety linked to a photochromic chromophore has been carried out starting from the related monomer trans-(S)-(+)-N-methyl-(2-methacryloyloxypropanoyl)-4-aminoazobenzene. The chiroptical properties in solution of the polymer have been investigated by circular dichroism and compared with those of the corresponding low molecular weight model compound, trans-(S)-(+)-N-methyl-(2-pivaloyloxypropanoyl)-4-aminoazobenzene. The optical activity displayed by the polymer is discussed in terms of extent of chiral conformations assumed by the macromolecules as a consequence of dipole-dipole interactions between the azoaromatic chromophores.