RESUMO
With the objective of developing new methods to acquire diagnostic information, the reconstruction of the broadband absorption coefficient spectra (µa [λ]) of healthy and chromophobe renal cell carcinoma kidney tissues was performed. By performing a weighted sum of the absorption spectra of proteins, DNA, oxygenated, and deoxygenated hemoglobin, lipids, water, melanin, and lipofuscin, it was possible to obtain a good match of the experimental µa (λ) of both kidney conditions. The weights used in those reconstructions were estimated using the least squares method, and assuming a total water content of 77% in both kidney tissues, it was possible to calculate the concentrations of the other tissue components. It has been shown that with the development of cancer, the concentrations of proteins, DNA, oxygenated hemoglobin, lipids, and lipofuscin increase, and the concentration of melanin decreases. Future studies based on minimally invasive spectral measurements will allow cancer diagnosis using the proposed approach.
RESUMO
The increase of tissue transparency through sequential optical immersion clearing treatments and treatment reversibility have high interest for clinical applications. To evaluate the clearing reversibility in a broad spectral range and the magnitude of the transparency created by a second treatment, the present study consisted on measuring the spectral collimated transmittance of lung tissues during a sequence of two treatments with electronic cigarette (e-cig) fluid, which was intercalated with an immersion in saline. The saline immersion clearly reverted the clearing effect in the lung tissue in the spectral range between 220 and 1000 nm. By a later application of a second treatment with the e-cig fluid, the magnitude of the optical clearing effect was observed to be about the double as the one observed in the first treatment, showing that the molecules of the optical clearing agent might have converted some bound water into mobile water during the first treatment.