458
K. malek et al.
Preliminary FtIR studies on biochemical changes observed in the human brain
in response to Parkinson’s disease (Pd) have focused on nerve cell bodies in the
substantia nigra [137]. degeneration and loss of dopamine-producing nerve cell
bodies in Pd mainly appear in this part of the brain. In general, the spectral region
of 1380–1000 cm
−1
(nucleic acids, carbohydrates, and amide III) shows the most
pronounced differences between control and pathological neurons. Additionally, a
variation in secondary structure of proteins is indicative of abnormal protein aggregation, which may be associated with a special role of the α-synuclein in the
aggregation process, since this protein constitutes a major component of Levy bodies characteristic of Parkinson’s disease. the examination of the amide I region
exhibits the shift of the most intensive amide I band from 1656 to 1662 cm
−1
in
the control and diseased substantia nigra, respectively, along with the presence of
the two shoulders at 1682 and 1643 cm
−1
in the Pd tissue. the authors associated
these spectral changes with appearing β-turn and β-sheet proteins in PD disorder of
neurons [137].
the FtIR profile of plaques found in the white matter of a chronic multiple sclerosis (mS) case in a human is associated only with the loss of phospholipids during
demyelination of the myelin sheet [138]. the most pronounced spectral changes
observed in the subcortical white matter of mS tissue sections derived from autopsy material reveals an increase in the 1740 cm
−1
absorbance band, along with
the reduction of the overall lipid content and broadening of the amide I band. the
latter is slightly shifted from 1660 cm
−1
in the control group to 1657 cm
−1
in mS
tissues. Such changes may be associated with lipid and protein oxidation induced
by reactive oxygen and nitrogen intermediates. thus, a role of free radicals in the
etiology of mS has been implicated, since the oxidation products are found in mS
lesion sites only. the interpretation of the observed spectral changes has been supported by in vitro FtIR studies of lipid and protein oxidation processes [139]. FtIR
imaging has been successfully used in monitoring chemical changes during the progression of multiple sclerosis as well as after its prevention [140].the experiment
was performed for an animal model, experimental autoimmune encephalomyelitis
(EAE), typical in studies on the mS etiopathology and treatment. IR images of cerebellum tissues collected during the progression of the disease confirms earlier results that there is a dramatic decrease in lipids located within sites of the mS lesions.
In addition, the images revealed that the formation of mS lesions is accompanied by
increasing content of nucleic acid (based on the increased intensity of the 965 cm
−1
band). these findings were in agreement with immunofluorescence staining for
myelin basic protein. discrimination of tissue layers and lesions required the use
of PCA and ANNs that indicated lipid, protein, and nucleic acids bands are spectral
markers for mS. the ANN approach enabled identification of early lesion formation before it could be clinically recognized. Interestingly, FtIR imaging indicates
chemical changes in EAE-protected mice by vaccination with Nogo-A. In particular
ture. Namely, α-helical proteins are found to be typical for the vaccinated EAE animals, while a higher content of proteins with antiparallel β-pleated structures occurs
in the diseased mice. the amide I bands are found at 1654, 1690, and 1635 cm
−1
,
K. malek et al.
Preliminary FtIR studies on biochemical changes observed in the human brain
in response to Parkinson’s disease (Pd) have focused on nerve cell bodies in the
substantia nigra [137]. degeneration and loss of dopamine-producing nerve cell
bodies in Pd mainly appear in this part of the brain. In general, the spectral region
of 1380–1000 cm
−1
(nucleic acids, carbohydrates, and amide III) shows the most
pronounced differences between control and pathological neurons. Additionally, a
variation in secondary structure of proteins is indicative of abnormal protein aggregation, which may be associated with a special role of the α-synuclein in the
aggregation process, since this protein constitutes a major component of Levy bodies characteristic of Parkinson’s disease. the examination of the amide I region
exhibits the shift of the most intensive amide I band from 1656 to 1662 cm
−1
in
the control and diseased substantia nigra, respectively, along with the presence of
the two shoulders at 1682 and 1643 cm
−1
in the Pd tissue. the authors associated
these spectral changes with appearing β-turn and β-sheet proteins in PD disorder of
neurons [137].
the FtIR profile of plaques found in the white matter of a chronic multiple sclerosis (mS) case in a human is associated only with the loss of phospholipids during
demyelination of the myelin sheet [138]. the most pronounced spectral changes
observed in the subcortical white matter of mS tissue sections derived from autopsy material reveals an increase in the 1740 cm
−1
absorbance band, along with
the reduction of the overall lipid content and broadening of the amide I band. the
latter is slightly shifted from 1660 cm
−1
in the control group to 1657 cm
−1
in mS
tissues. Such changes may be associated with lipid and protein oxidation induced
by reactive oxygen and nitrogen intermediates. thus, a role of free radicals in the
etiology of mS has been implicated, since the oxidation products are found in mS
lesion sites only. the interpretation of the observed spectral changes has been supported by in vitro FtIR studies of lipid and protein oxidation processes [139]. FtIR
imaging has been successfully used in monitoring chemical changes during the progression of multiple sclerosis as well as after its prevention [140].the experiment
was performed for an animal model, experimental autoimmune encephalomyelitis
(EAE), typical in studies on the mS etiopathology and treatment. IR images of cerebellum tissues collected during the progression of the disease confirms earlier results that there is a dramatic decrease in lipids located within sites of the mS lesions.
In addition, the images revealed that the formation of mS lesions is accompanied by
increasing content of nucleic acid (based on the increased intensity of the 965 cm
−1
band). these findings were in agreement with immunofluorescence staining for
myelin basic protein. discrimination of tissue layers and lesions required the use
of PCA and ANNs that indicated lipid, protein, and nucleic acids bands are spectral
markers for mS. the ANN approach enabled identification of early lesion formation before it could be clinically recognized. Interestingly, FtIR imaging indicates
chemical changes in EAE-protected mice by vaccination with Nogo-A. In particular
ture. Namely, α-helical proteins are found to be typical for the vaccinated EAE animals, while a higher content of proteins with antiparallel β-pleated structures occurs
in the diseased mice. the amide I bands are found at 1654, 1690, and 1635 cm
−1
,