Only early diagnosis of laryngeal cancer can prevent major or mutilating treatment. Recently, autofluorescence endoscopy has been developed to enhance endoscopic information and succeeded in facilitating the detection and demarcation of precancerous lesions, carcinoma in situ and cancer of the larynx. The aim of the present study is to quantify autofluorescence imaging by spectroscopy in order to validate the above mentioned findings. In a prospective study, 42 patients with suspected one-sided precancerous or cancerous lesions of the vocal folds were investigated during microlaryngoscopy. Autofluorescence (AF) was induced by filtered blue light (375-440 nm) of a xenon short arc lamp and processed by a CCD camera system (D-light AF System, STORZ, Germany). Autofluorescence images were gathered in a contact mode. For spectrometric measurements an optical multi channel analyzer (AVS-USB 2000, Avantes, The Netherlands) was applied. The results were compared to pathohistological findings. Under blue light excitation normal mucosa presented a bright green fluorescence. Intensity increased from the ventricular folds to the subglottic area. Averaged spectra of the normal laryngeal mucosa demonstrated different fluorescence maxima at 475, 515, 550, 600 and 630 nm. Highest intensity was measured at 515 nm explaining the green appearance of the autofluorescence picture. In contrast, precancerous as well as cancerous lesions showed a significant decrease in autofluorescence intensity with a reddish-violet color. Highest loss of autofluorescence intensity was measured at 515 nm. At this wave length intensity dropped 70% on average in comparison to the regularly appearing contralateral vocal fold. In contrast to 515 nm, the loss of intensity at 630 nm amounted to 38%. Sensitivity amounted to 97% and specificity to 82%. Comparable to autofluorescence endoscopy a differentiation between precancerous and cancerous lesions could not be detected. The reason for the loss of autofluorescence may predominantly be caused by mucosal thickening but also by changes in metabolism and higher nuclei density.

The interaction of Cu(II) with di- and tripeptides each containing phenylalanine, tryptophan or histidine in the amino acid chain has been investigated by means of electron spin resonance (ESR) and optical absorption spectroscopy. Cu(II) complexes of dipeptides and tripeptides exhibit different magnetic and optical parameters. Dipeptide complexes have larger gparallel-values and smaller A parallel values than tripeptide complexes. When compared to dipeptide complexes, the d-d band of the central metal ion is blue shifted for tripeptide complexes. There are no significant difference in the behavior of Cu(II) peptide complexes containing phenylalanine or tryptophan. Complexes of histidine containing peptides, however, show modified spectra caused by the participation of the imidazole nitrogen in the coordination to Cu(II). The imidazole nitrogen seems to coordinate in-plane with other coordinating atoms or in an axial position depending on the kind of peptide.

Abstract The anticancer active compound, cis-dichloro-diammine platinum (II), and the biomolecules cytosine and thymine form paramagnetic complexes in aqueous solution. The electron spin resonance spectra which can be attributed to paramagnetic platinum, exhibit large anisotropy in frozen solution as well as in liquid solution. This fact can be explained by assuming poly-meric structures also in liquid solution.

Abstract The observation of a new type of ESR spectrum in the course of redox experiments on a platinum uracil "blue" compound is reported. Some characteristic features of the ESR and optical absorption spectra are described. A tentative analysis of the ESR spectrum is pre-sented, based on the assumption of localized states.

No abstract