Biomedical Engineering Reference
In-Depth Information
was fed the sufficient oil (perilla oil) from mothers to offspring. The infra-
red spectra of microsomes under the two dietary conditions without the
learning task showed no significant difference in the range 1000-3000 cm −1 .
Only after the learning task were the infrared spectral differences noted
between the microsomal membranes from both groups. Spectral differ-
ences were observed mainly in the absorption bands of fatty acid ester at
around 1730 cm −1 (sn-2 position), those of phosphate and oligosaccharides in
the range of 1050-1100 cm −1 , and a band at around 1145 cm −1 . These results
suggest changes in hydration of the membrane surface and modification in
the oligosaccharide environment (removal or modification) of microsomes,
which may be correlated in part with dietary oil-induced changes in learn-
ing performance [119].
Lakshmi et al. conducted a Raman study on radiation damage of brain
tissue in mice. A set of studies were carried out on brain tissue from mice
subjected to irradiation to identify the biochemical changes in tissue as the
result of radiotherapy and radiation injury. It was shown that brain irradia-
tion produces drastic spectral changes even in tissue far removed from the
irradiation site. The changes were very similar to those produced by the
stress of inoculation and restraint and the administration of an anaesthetic
drug. While the changes produced by stress or anesthetics last for only a
short time (a few hours to 1 or 2 days), radiation-induced changes persist
even after one week. The results also supported the hypothesis that various
protective factors are released throughout the body when the central ner-
vous system (CNS) is exposed to radiation [120].
Human brain tissue, in particular white matter, contains high lipid con-
tent. These brain lipids can be divided into three principal classes: neutral
lipids including the steroid cholesterol, phospholipids, and sphingolipids.
Major lipids in normal human brain tissue are phosphatidylcholine, phos-
phatidylethanolamine, phosphatidylserine, phosphatidylinositol, phospha-
tidic acid, sphyngomyelin, galactocerebrosides, gangliosides, sulfatides, and
cholesterol. Minor lipids are cholesterol ester and triacylglycerides. Detailed
research on near-infrared Raman spectra was carried out by Krafft et al.
They recorded the Raman spectra of 12 major and minor brain lipids with
785-nm excitation in order to identify their spectral fingerprints for qualita-
tive and quantitative analysis [121].
Oral Squamous Cell Carcinoma
Oral tissues have also been widely investigated by a number of researchers
(Table 4.9). Y. Fukuyama et al. used FTIR microscopy to study the differences
between oral squamous cell carcinoma and normal mucosa (normal gingival
epithelium or normal subgingival tissue). The tissue spectra were compared
 
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