Paolo Ferraris

Microimaging FTIR of head and neck tumors. IV.

On continuing our studies on head and neck neoplasia, specimens from salivary gland tumors have been explored by using infrared microimaging spectroscopy to discern healthy from neoplastic tissues. Samples with Warthin tumor, epithelial displasia, marginal B‐cell lymphoma, low‐grade adenocarcinoma, and adenoid cystic carcinoma pathologies have been investigated by using conventional light sources. Changes were monitored at the molecular level, probing spectral markers such as Amide I and II, phosphate, nucleic acids, and carbohydrates vibrational modes. In all cases, supervised and unsupervised spectral analyses resulted in satisfactory agreement with histopathological findings. Microsc. Res. Tech., 2009.

FTIR microspectroscopy of melanocytic skin lesions: a preliminary study

Fourier transform infrared (FTIR) microspectroscopy has been employed to investigate benign (ordinary dermal and Reed nevi), dysplastic and malignant (invasive melanoma) skin lesions through the analysis of spectral changes of melanocytes as well as in the evaluation of the presence of melanin. Hierarchical cluster analysis and principal component analysis led to a satisfactory separation of malignant from dysplastic and normal melanocytes. Also, on enlarging the clustering with spectra from Reed and dermal nevi, the multivariate analysis segregated well the spectral data into discrete clusters, allowing the obtaining of reliable average spectra for analysis at the molecular level of the main groups or components responsible for the biological and biochemical changes. The most significant spectral characteristics appear to be related to differences in secondary protein structures, in nucleic acid conformation, in intra- and intermolecular bonding. In all cases, supervised and unsupervised spectral analyses resulted in satisfactory agreement with histopathological findings.

A new approach to evaluate aging effects on human oocytes: Fourier transform infrared imaging spectroscopy study

OBJECTIVE To characterize from a vibrational point of view the alterations caused by aging on human oocytes. DESIGN Reproductive biology. SETTING Private assisted reproductive technology clinic, synchrotron beam line, and university infrared laboratory. PATIENT(S) Twenty women of different ages (30 ± 2 and 39 ± 2 years) selected on the basis of detailed inclusion criteria and submitted to controlled ovarian stimulation according to a specific protocol. INTERVENTION(S) Collection of 68 supernumerary oocytes that were not used during the IVF cycle from the above cited consenting patients. MAIN OUTCOME MEASURE(S) Focal Plane Array Fourier transform infrared (FTIR) analysis of human oocytes. RESULT(S) Specific spectral differences were highlighted in the two experimental groups of oocytes. In particular, in oocytes of 39-year-old women, the occurrence of peroxidative processes and a decrease in the amount of carbohydrates were observed, together with alterations in the phospholipid membrane, proteic pattern, and nucleic acids content. CONCLUSION(S) For the first time, FTIR spectroscopy was applied to human oocytes, leading to strong evidence of damage from aging in the gametes of mature women, which could be related to a decline in reproductive function. All the information obtained may be considered useful to improve the scientific knowledge on human reproduction and to exploit new strategies for detecting oocyte aging.

Microimaging FT-IR of Head and Neck Tumours. The case of salivary glands

This technique aims to further exploit the potentiality of infrared spectroscopy in isolating and defining spectral profiles in salivary glands attributable to various kinds of cancer: Warthin tumour, polymorphous low-grade adenocarcinoma, oral epithelium with dysplasia, adenoid cystic carcinoma, lymphoma, and the corresponding healthy tissues. Thirty three samples from patients with diagnosed salivary gland pathology were analyzed. Two adjacent sections of tissues (5 μm thickness) were used for both histopathological and FTIR analysis.

Melatonin effects on Fundulus heteroclitus reproduction

This study aimed to investigate the effects of two different doses (100nM (M1) and 1µM (M2)) of exogenous melatonin on the reproductive capacity of Fundulus heteroclitus. Eight days of melatonin exposure significantly increased the fecundity and embryo survival of F. heteroclitus only in the M2 group compared with the control; the hatching rate was unaffected. Moreover, increases in the local expression of the melatonin receptor (mtnr) gene during follicle maturation were found; however, there were no differences between the experimental groups. Furthermore, in vitro melatonin-treated follicles showed a significantly higher germinal vesicle break down percentage compared with the control, while SDS-PAGE showed no difference in the electrophoretic pattern of the major yolk proteins. Nevertheless, densitometry revealed a greater intensity of the 118-, 95- and 40-kDa components in groups treated with melatonin. Finally, Fourier transform infrared microspectroscopy was applied to classify the different stages of oocyte development (Stages I-II, III and IV) on the basis of their macromolecular composition. The effects induced by melatonin on oogenesis were investigated by comparing vibrational spectra of females exposed to melatonin with those of controls. Changes to the Amide I band, corresponding to an increase in β-structure, were found in oocytes of females exposed to the highest melatonin dose. These results highlight the positive role of melatonin, which is able to enhance the reproductive capacity of F. heteroclitus. Further studies are in progress to better explain the molecular mechanisms by which melatonin treatment affects reproduction in this marine species.

Wetting properties of dioleoyl-phosphatidyl-choline bilayers in the presence of trehalose: an X-ray diffraction study

The combined effect of trehalose and temperature on the wetting properties of L-alpha-dioleoyl-phosphatidyl-choline (DOPC) model membranes in excess aqueous solutions has been analyzed by X-ray diffraction and extended electron density map reconstruction. At room temperature, DOPC in excess water forms a fluid lamellar L(alpha) phase. In the presence of trehalose, no phase transitions occur, but repeat and intermembrane distances increase considerably. Electron density maps show that trehalose in solution promotes a straightening of the hydrocarbon chain packing and a reduction of the molecular average area at the polar-apolar interface. Accordingly, the increased intermembrane distance is interpreted as a clear indication of a sugar screening effect of the van der Waals attractive contribution in the lamellar stacks, which overcomes the eventual decreasing of the repulsive fluctuations due to the hardening of the bilayer. By contrast to the thermally induced membrane swelling observed in excess water, in the presence of trehalose the DOPC bilayer thickness and repeat and intermembrane distances decrease continuously with temperature. While the thermal dependence of bilayer thickness is a consequence of the chain conformational disorder promoted by temperature, the changes in the intermembrane distance can be explained only assuming a trehalose-induced re-setting of the long-range force balance. The final results confirm the complex mechanism by which trehalose stabilize lipid bilayers.

Effect of ingested tungsten oxide (WOx) nanofibers on digestive gland tissue of Porcellio scaber (Isopoda, Crustacea): fourier transform infrared (FTIR) imaging.

Tungsten nanofibers are recognized as biologically potent. We study deviations in molecular composition between normal and digestive gland tissue of WOx nanofibers (nano-WOx) fed invertebrate Porcellio scaber (Iosopda, Crustacea) and revealed mechanisms of nano-WOx effect in vivo. Fourier Transform Infrared (FTIR) imaging performed on digestive gland epithelium was supplemented by toxicity and cytotoxicity analyses as well as scanning electron microscopy (SEM) of the surface of the epithelium. The difference in the spectra of the Nano-WOx treated and control cells showed up in the central region of the cells and were related to lipid peroxidation, and structural changes of nucleic acids. The conventional toxicity parameters failed to show toxic effects of nano-WOx, whereas the cytotoxicity biomarkers and SEM investigation of digestive gland epithelium indicated sporadic effects of nanofibers. Since toxicological and cytological measurements did not highlight severe effects, the biochemical alterations evidenced by FTIR imaging have been explained as the result of cell protection (acclimation) mechanisms to unfavorable conditions and indication of a nonhomeostatic state, which can lead to toxic effects.