Ole Faurskov Nielsen

Distinctive molecular abnormalities in benign and malignant skin lesions: studies by Raman spectroscopy.

Abstract— Near‐infrared Fourier transform Raman spectroscopy is an analytical, nondestructive technique that provides information about the molecular structure of the investigated sample. The molecular structure of proteins and lipids differs between neoplastic and normal tissues and therefore Raman spectroscopy has been considered promising for the diagnosis of cancer. We aimed to compare the molecular structure of normal skin, benign and malignant skin lesions by the near‐infrared Fourier transform Raman spectroscopy. Biopsies were obtained from the following skin lesions: skin tag, dermatofibroma, seborrhoeic keratosis, actinic keratosis, keratoacan‐thoma, basal cell carcinoma, squamous cell carcinoma, nevus intradermal, nevus compositus, dysplastic nevus and lentigo maligna. Control skin was harvested from the vicinity of these lesions. In the Raman spectra, the secondary structure of the proteins was reflected by the amide vibrations of peptide bonds. The principal lipid vibrations were twisting and wagging (CH2) and CH stretching vibrations. Histologically distinguishable lesions showed specific combinations of band changes indicating alterations in the protein conformation and in the molecular structure of the lipids. Histogenetically related lesions (actinic keratosis and sqamous cell carcinoma) produced similar but not identical patterns of spectral changes. Because the examined skin lesions produced reproducible and unique spectra, we suggest that Raman spectroscopy will be useful for diagnosis of skin lesions.

Genetic regulation of chlorophyll synthesis analyzed with mutants in barley.

Barley seedlings homozygous both for the xantha-135 and tigrina-d12 mutation accumulate magnesium protopophyrins and other precursors of chlorophyllide constitutively in darkness. The homozygous double mutant xantha-f10, tigrina-O34 produces protoporphyrin constitutively. These results provide evidence for the control of chlorophyllide synthesis in higher plants through the products of regulatory genes in the nucleus.

Vibrational spectroscopic studies on the natural product, columbianadin

NIR-FT Raman and FT-IR spectra of columbianadin, extracted from seeds and roots of Heracleum candolleaum, were recorded and analyzed. The vibrational frequencies of the compound have been computed using semi-empirical AM1 method and compared with experimental values. The C=O stretching frequencies of the carbonyl groups have been lowered due to conjugation. The CH stretching and bending vibrations of CH3 groups of the ester part indicate the presence of hyperconjugation effect. Characteristic ring vibrations have also been identified.

NIR-FT Raman spectroscopy as a diagnostic probe for mummified skin and nails

Abstract Raman spectroscopy is able to provide novel information non-destructively in the analysis of ancient skin tissue samples. The technique is well-suited to partially desiccated or wet samples of skin, which may have been subjected to varying degrees of degradation, depending on the burial environment. Suitable selection of wavelength of excitation and use of a Raman microscope offer a means of accessing information from small samples, which may be required for study afterwards using destructive analytical methods. From comparisons with the Raman spectra of healthy and diseased contemporary skin specimens, it is possible to discover whether the skin preservation has been natural or assisted by chemicals used in mummification processes. Such information is of importance in archaeological conservation and can shed light on historical practices. In this study will be presented the results from Raman spectroscopic analysis of the skin of the 5200-year-old “ice-man” of the Alps and, skin and nail samples from the mediaeval Qilakitsoq ice-mummies (500-year-old) and skin from the hot-desert Chiribaya Mummies (1000-year-old).

Plasticizers in P.V.C. and the Occurence of Hefatitis in A Haemodialysis Unit: A Preliminary Communication

In a four-year period three isolated cases of hepatitis were observed within a period of 2 months in a haemodialysis unit. The cases occurred in 3 patients during testing of new haemodialysis equipment. Liver biopsy in 2 patients showed non-specific hepatitis and changes as in “viral hepatitis” respectively. From the tested blood tubings, manufactured from polyvinylchloride (P.V.C.), diaethylphthalate was washed out in an amount of 10–20 mg per litre aqueous perfusate. From the tubings normally used in the department this compound was not released on perfusion, and the symptoms disappeared rapidly when treatment with the use of these tubings was resumed.

Vibrational spectra and ab initio molecular orbital calculations of the novel anti-cancer drug combretastatin A-4 prodrug

The NIR-FT Raman and FT-IR spectral studies of the novel antineoplastic and antiangiogenesis substance comprestatin A-4 prodrug (CA4P) were carried out. The equilibrium geometry, various bonding features and harmonic vibrational frequencies of CA4P have been investigated with the help of B3LYP density functional theory (DFT) method. The most preferred cis-configuration for its bioactivity has been demonstrated on the basis of torsional potential energy surface (PES) scan studies. Stability of the molecule arising from hyperconjugative interactions leading to its bioactivity, charge delocalization and mesomeric effects have been analyzed using natural bond orbital (NBO) analysis. Detailed assignments of the vibrational spectra have been made with the aid of theoretically predicted vibrational frequencies. The optimized geometry shows near-planarity of phenyl rings and perpendicular conformation of meta substituted methoxy group. The vibrational analysis confirms the differently acting ring modes, steric repulsion, pi conjugation and back-donation.

Vibrational spectra of 1,3,5-hexatriene and methylated derivatives

Abstract The ground state vibrational spectra of E -hexatriene, Z -hexatriene, E,E -heptatriene, E,E,E -octatriene, and E -2,5-dimethyl-hexatriene are reported. For E - and Z -hexatriene complete vibrational assignments, and for heptatriene, octatriene, and dimethyl-hexatriene near-complete assignments are obtained. The effects of terminal and lateral methyl-substitution are compared.

The vibrational spectra of maleic anhydride and its deuterated species

Abstract The infrared spectra of maleic anhydride and its mono- and dideuterated species were recorded in the region 5000-50 cm −1 in the vapour phase and in solution. Raman spectra of the solids and supercooled melts were obtained. Assignments of the fundamental vibrational frequencies are given, based upon semiquantitative polarization data and the infrared vapour contours as well as on the product rule and complete isotopic rule for the three compounds.

Photoconvertible protochlorophyll(ide)635650 in vivo: A single species or two species in dynamic equilibrium?

Abstract The decreasing absorbances in vivo of protochlorophyll(ide) at 635 and 650 nm bear the same relationships to one another during photoconversion to chlorophyll(ide) a in the leaves of dark-grown barley seedlings, regardless of whether the actinic light is absorbed primarily at 630, 640 or 671 nm. Accordingly, the absorption bands at 635–637 and 650 nm of photoconvertible protochlorophyll(ide) are attributed to a single species of membrane-bound protochlorophyll(ide) molecule or, alternatively, to two species which are in dynamic equilibrium.

Kinetics and quantum yield of photoconversion of protochlorophyll(ide) to chlorophyll(ide) a

Abstract The kinetics of photoconversion of protochlorophyll(ide) to chlorophyll(ide) a were investigated in dark-grown barley leaves and in a preparation of protochlorophyll holochrome subunits. In the subunits the conversion obeyed first-order kinetics. This indicates that the excitation of protochlorophyll(ide), energy loss through deexcitation, and the reduction of excited protochlorophyll(ide) are all reactions that follow first-order kinetics with respect to protochlorophyll(ide) in protochlorophyll holochrome subunits. In contrast, photoconversion in leaves obeyed neither first- nor second-order kinetics. This prompted the postulation of an additional route within macromolecular units of protochlorophyll holochrome, whereby energy is lost from excited protochlorophyll(ide) by a reaction that is not first order. Such a process might be energy transfer from excited protochlorophyll(ide) to newly-formed chlorophyll(ide) a. A dynamic model describing photoconversion in macromolecular units was derived. The model is consistent with the observed progress of photoconversion in barley leaves and in protochlorophyll holochrome subunits from barley. Determinations of the quantum yield of photoconversion in protochlorophyll holochrome subunits gave values of 0.4–0.5 molecules · quantum−1. Estimates of the initial quantum yield of the photoconversion process in leaves fell into the same range. The dynamic model allows predictions on the progressively decreasing quantum yield as the photoconversion proceeds in macromolecular units.