Vibrational Spectroscopy and Cancer - Vibrational Spectroscopy for Tissue Analysis - page 86

was characterised by Raman bands at 752 cm −1 , which corresponds to the por-
phyrin breathing mode. They found that the intensity of this band decreased
by 34.1% over a period of 25 minutes after the administration of alcohol. In a
further study of the dependence of denaturation on alcohol concentration, it
was discovered that the decrease in the intensity of the 752 cm −1 band became
more rapid and more prominent as the alcohol concentration increased [139].
Application of Raman spectroscopy of serum for cancer detection was
investigated by Li and Jin. The spectra of serum from cancerous and nor-
mal individuals were analysed. Three Raman peaks with intensities of 1005,
1156, and 1523 cm −1 were consistently observed from normal blood serum
samples, whereas no peaks or only very weak peaks were detected from
tumourous cases [140].
Mordechai et al. applied FTIR microspectroscopy for the follow-up of
childhood leukaemia chemotherapy. A case study was presented where
lymphocytes isolated from two children before and after the treatment were
characterized using microscopic FTIR spectroscopy. Significant changes in
the spectral pattern in the wavenumber region between 800-1800 cm −1 were
found after the treatment. Preliminary analysis of the spectra revealed that
the protein content decreased in the T-type acute lymphoblastic leukaemia
(ALL) patient before the treatment in comparison to the age-matched con-
trols. It was shown that the chemotherapy treatment results in decreased
nucleic acids, total carbohydrates, and cholesterol contents to a remarkable
extent in both B- and T-type ALL patients [141].
Andrus collected the spectra of various grades of malignant non-Hodgkin's
lymphoma. Structural changes to lipids and proteins in the wavenumber
region of 2800-300 cm −1 , seen as an increasing CH 3 /CH 2 ratio and decreasing
symmetric CH 2 /asymmetric CH 2 ratio, were found to occur with increasing
lymphoma grade. Rising ribose content (1121 cm −1 ) was seen to correlate with a
rising 996/966 cm −1 ratio (an index of RNA/DNA) with increasing malignancy
grade as well. It was concluded that this method can potentially be applied to
clinical cancer grading, or in vitro cancer treatment sensitivity testing [142].
Isabelle et al. analysed oesophageal lymph nodes with Raman and FTIR
spectroscopy in combination with multivariate statistical analysis tools, to
investigate some of the major biochemical and morphological changes tak-
ing place during carcinogenesis and metastasis and to develop a predic-
tive model to correctly differentiate cancerous from benign tissue [143]. The
results of this study showed that Raman and infrared spectroscopy man-
aged to correctly differentiate between cancerous and benign oesophageal
lymph nodes with a training performance greater than 94% using PCA and
LDA. It was also concluded that cancerous nodes have higher nucleic acid
but lower lipid and carbohydrate content compared to benign nodes, which
is indicative of increased cell proliferation and loss of differentiation.
Chan et al. analysed populations of normal T and B lymphocytes from four
healthy individuals and cells from three leukaemia patients using laser trap-
ping Raman spectroscopy [144]. A combination of two multivariate statistical