• Journal of the Korean Magnetic Resonance Society
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• v.4 no.1
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• pp.19-28
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• 2000

Authors evaluated alterations of observable metabolite ratios between the cerebral lesion and the contralateral region related to the clinical symptomatic side in levodopa-treated Parkinson's disease (PD) and investigated correlation between age in patients with PD and metabolite ratios of the lesion. Patients with levodopa-treated PD (n = 54) and age-matched normal controls (n = 15) underwent magnetic resonance spectroscopy (MRS) examinations using a stimulated echo acquisition mode (STEAM) pulse sequence that provided 2$\times$2$\times$2 cm3 volume of interest in the selected regions of substantia nigra (SN) and putamed-globus pallidus (PG). To evaluate dependence of metabolite ratios on age, we divided into two groups (i.e., younger and older age). We quantitatively measured N-acetylaspartate (NAA), creatine (Cr), choline-containing compounds (Cho), inositols (Ins), and the sum of glutamate (Glx) and GABA levels and obtained proton metabolite ratios relative to Cr using a Marquart algorithm. Compared with the contralateral region, a significant neuronal laterality of the NAA/Cr ratio in the lesion of SN related to the clinical symptomatic side was established (P = 0.01), but was not established in the lesion of PG (P = 0.24). Also, Cho/Cr ratio tended toward significance in the lesion of SN (P = 0.07) and was statistically significant in the lesion of PG(P = 0.01). Compared with that in the younger age group, NAA/Cr ratio in the older age was decreased in the lesion of SN (P = 0.02), while NAA/Cr ratio was not statistically significant in the lesion of PG ( P = 0.21). Significant metabolic alterations of NAA/Cr and Cho/Cr ratios might be closely related with functional changes of neuropathological process in SN and PG of levodopa treated PD and could be a valuable finding for evaluation of the PD. A trend of NAA/Cr reduction, being statistically significant in older patients, could be indicative of more pronounced neuronal damage in the SN of the progressive PD.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.2
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• pp.72-77
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• 2015

Purpose: Deficits of the respiratory chain are reported to be the major cause of Leigh syndrome is said to be the underlying causes. The need for biochemical diagnosis to draw more accurate diagnosis or prognosis to support treatments is rapidly increasing. This study tried to analyze the aspects of clinical characteristics and biochemical diagnosis of mitochondrial respiratory chain complex (MRC) defect in Leigh syndrome, using methods of biochemical enzyme assay. Methods: We included total number of 47 patients who satisfied the clinical criteria of Leigh syndrome and confirmed by biochemical diagnosis. All those patients went through muscle biopsy to perform biochemical enzyme assay to analyze MRC enzyme in order to find the underlying cause of Leigh syndrome. Results: MRC I defect was seen in 23 (48.9%) cases taking the first place and MRC IV defect in 15 (31.9%) following it. There were 9 (19.2%) cases of combined MRC defect. Combined cases of type I and IV were detected in 7 (14.9%) patients while type I and V in 2 (4.3%). The onset age of symptom was less than 1 year old in 28 (59.6%). The most common early symptom, observed in 23 (48.9%), was delayed development, but there were other various neurological symptoms observed as well. In regard with the disease progression, 35 (74.5%) patients showed slowly progressive course, the one that progressed continuously but slowly over 2 years of period. As for Maximum motor development, 22 (46.8%) were bed-ridden state, most of them suffering serious delayed development. Patients showed various symptoms with different organs involved, though neuromuscular involvement was most prominent. Delayed development was seen in all cases. Multifocal lesion in brain MRI study was seen in 36 (76.6 %) cases, taking a greater percentage than 11 (23.4%) cases with single lesion. In MR spectroscopy study, the characteristic lactate peak of mitochondrial disease was identified in 20 (42.6%) patients. Conclusions: Further analysis of clinical and biochemical diagnosis on more extended group of patients with Leigh syndrome will enable us to improve diagnostic precision and to understand the natural course of mitochondrial disease.

• Investigative Magnetic Resonance Imaging
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• v.21 no.1
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• pp.1-8
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• 2017

Purpose: To investigate the exchange and redistribution of hyperpolarized $^{13}C$ metabolites between different pools by temporally analyzing the relative fraction of dual $T_2{^*}$ components of hyperpolarized $^{13}C$ metabolites. Materials and Methods: A dual exponential decay analysis of $T_2{^*}$ is performed for [1-$^{13}C$] pyruvate and [1-$^{13}C$] lactate using nonspatially resolved dynamic $^{13}C$ MR spectroscopy from mice brains with tumors (n = 3) and without (n = 4) tumors. The values of shorter and longer $T_2{^*}$ components are explored when fitted from averaged spectrum and temporal variations of their fractions. Results: The $T_2{^*}$ values were not significantly different between the tumor and control groups, but the fraction of longer $T_2{^*}$ [1-$^{13}C$] lactate components was more than 10% in the tumor group over that of the controls (P < 0.1). The fraction of shorter $T_2{^*}$ components of [1-$^{13}C$] pyruvate showed an increasing tendency while that of the [1-$^{13}C$] lactate was decreasing over time. The slopes of the changing fraction were steeper for the tumor group than the controls, especially for lactate (P < 0.01). In both pyruvate and lactate, the fraction of the shorter $T_2{^*}$ component was always greater than the longer $T_2{^*}$ component over time. Conclusion: The exchange and redistribution of pyruvate and lactate between different pools was investigated by dual component analysis of the free induction decay signal from hyperpolarized $^{13}C$ experiments. Tumor and control groups showed differences in their fractions rather than the values of longer and shorter $T_2{^*}$ components. Fraction changing dynamics may provide an aspect for extravasation and membrane transport of pyruvate and lactate, and will be useful to determine the appropriate time window for acquisition of hyperpolarized $^{13}C$ images.

• Journal of the Korean Magnetics Society
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• v.14 no.1
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• pp.38-44
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• 2004

The iron doped colossal magnetoresistance materials with La-Ba-Mn-O perovskites structure have been synthesized by chemical reaction of sol-gel methods. Their crystallographic and magnetic properties have been studied with x-ray diffraction, VSM, RBS, Mossbauer spectroscopy, and magnetoresistance measurements. The crystal structure of the La$\_$0.67/Ba$\_$0.33/Mn$\_$0.99/Fe$\_$0.01/ $O_3$ at room temperature was determined to be orthorhombic of Pnma. The lattice parameters a$\_$0/ and c$\_$0/ increased gradually, but b$\_$0/ deceased with increase of iron substitution. The magnetization and coercivity deceased, also the Curie temperature decreased from 360 K as x increased from 0.00 to 0.05. Magnetoresistence measurements were carried out, and the maximum MR ($\Delta$$\rho$/$\rho$(0)) was observed at 281 K, about 9.5 % in 10 kOe. The temperature of maximum resistance (R$\_$MAX/) decreased with increasing substitution of Fe ions and a semiconductor-metal transition temperature (T$\_$SC-M/) decreased too. This phenomena show that ferromagnetic transition temperature decreased by substituting Fe for Mn ions, it decreases double exchange interaction. This result accords with magnetic structure of neutron diffraction. Mossbauer spectra of La$\_$0.67/Ba$\_$0.33/Mn$\_$0.99/Fe$\_$0.01/ $O_3$were taken at various temperatures ranging from 15 to 350 K. With lowering temperature of the sample, two magnetic phases were increased and finally it showed the two sharp sextets of spectra at 15 K. The isomer shift at all temperature range is about 0.3 mm/s relative to Fe metal, which means that both Fe ions are Fe$\^$3+/ states.Fe$\^$3+/ states.