• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2003.09a
• /
• pp.76-76
• /
• 2003

Purpose: To assess clinical proton MR spectroscopy (MRS) as a noninvasive method for evaluating tumor malignancy at 3T high field system. Methods: Using 3T MRI/MRS system, localized water-suppressed single-voxel technique in patients with brain tumors was employed to evaluate spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cr) and lactate. On the basis of Cr, these peak areas were quantificated as a relative ratio. Results: The variation of metabolites measurements of the designated region in 10 normal volunteers was less than 10%. Normal ranges of NAA/Cr and Cho/Cr ratios were 1.67$\pm$018 and 1.16:1:0.15, respectively. NAA/Cr ratio of all tumor tissues was significantly lower than that of the normal tissues (P=0.005). Cho/Cr ratio of high-grade gliomas was significantly higher than that of low-grade gliomas (P= 0.001), Except 4 menigiomas, lactate signal was observed in all tumor cases. Conclusions: The present study demonstrated that the neuronal degradation or loss was observed in all tumor tissues. Higher grade of brain tumors was correlated with higher Cho/Cr ratio, indicating a significant dependence of Cho levels on malignancy of gliomas. This results suggest that clinical proton MR spectroscopy could be useful to predict tumor malignancy. Acknowledgement: This study was supported by a grant of the Mid and Long Term Nuclear R/D Plan Program, Ministry of Science and Technology, Republic of Korea.

• YAKHAK HOEJI
• /
• v.34 no.5
• /
• pp.311-322
• /
• 1990

This study primarily attempted to investigate the effects of methamphetamine on stereotyped behavior. Furthermore, an extensive experiment was conducted to examine the cortex methamphetamine concentration and levels of dopamine, serotonin, and their metabolites in striatum, septum and hypothalamus. Following treatment with 10 mg/kg methamphetamine, stereotyped behavior was observed in 10 minutes. Consequently female rats displayed more intense and longer lasting activity than the male. The concentration of cortex methamphetamine was even higher in female than male. The administration of methamphetamine increased the rate of dopamine turnover-i.e. lower dopamine, higher homovanillic acid in the striatum, septum. The highest rate was found in the striatum. Methamphetamine decreased the levels of serotonin, and its metabolite of 5-indoleacetic acid in the striatum, septum. An intensity in behavioral response was accompanied by an increase in dopamine turnover, a decrease in serotonergic transmission. The reduction of 3,4-dihydroxyphenylacetic acid-i.e. the metabolite of dopamine was due not to the inhibition of monoamine oxidase but to the induction of monoamine oxidase but to the induction of catechol-O-methyltransferase. The phenomenon of biogenic amines by methamphetamine concurred upon the concentration of methamphetamine in the brain. This process preceded stereotyped behavior. After single injection of 10 mg/kg methamphetamine, the levels of biogenic amines recovered within 6 hours.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.31 no.3
• /
• pp.131-145
• /
• 2020

The microbiota-gut-brain axis, which refers to the bidirectional communication pathway between gut bacteria and the central nervous system, has a profound effect on important brain processes, from the synthesis of neurotransmitters to the modulation of complex behaviors such as sociability and anxiety. Previous studies have revealed that the gut microbiota is potentially related to not only gastrointestinal disturbances, but also social impairment and repetitive behavior-core symptoms of autism spectrum disorder (ASD). Although studies have been conducted to characterize the microbial composition in patients with ASD, the results are heterogeneous. Nevertheless, it is clear that there is a difference in the composition of the gut microbiota between ASD and typically developed individuals, and animal studies have repeatedly suggested that the gut microbiota plays an important role in ASD pathophysiology. This possibility is supported by abnormalities in metabolites produced by the gut microbiota and the association between altered immune responses and the gut microbiota observed in ASD patients. Based on these findings, various attempts have been made to use the microbiota in ASD treatment. The results reported to date suggest that microbiota-based therapies may be effective for ASD, but largescale, well-designed studies are needed to confirm this.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.6
• /
• pp.2021-2026
• /
• 2011

AgNPs (silver nanoparticles) has been widely used for the commercial products, which have antimicrobial agent, medical devices, food industry and cosmetics. Despite, AgNPs have been reported as toxic to the mammalian cell, lung, liver, brain and other organs and many researchers have investigated the toxicity of AgNPs. In this study, we investigated toxicity of the AgNPs to the liver cell using metabolomics based on HRMAS NMR (High Resolution Magic Angle Spinning Nuclear Magnetic Resonance) technics, which could apply to the intact tissues or cells, to avoid the sample destruction. Target profiling and multivariative statistical analysis were performed to analyze the 1D $^1H$ spectrum. The results show that the concentrations of many metabolites were affected by the AgNPs in the liver cell. The concentrations of glutathione (GSH), lactate, taurine, and glycine were decreased and most of amino acids, choline analogues, and pyruvate were increased by the AgNPs. Moreover, the levels of the metabolites were recovered upto similar level of metabolites in the normal cell by the pre-treatment of NAC, external antioxidant. The results suggest that the depletion of the GSH by the AgNPs might induce the conversion of lactate and taurine to the pyruvate.

• Applied Biological Chemistry
• /
• v.38 no.1
• /
• pp.37-41
• /
• 1995

The effect of age on the metabolism of progesterone was studied in the rat brain. Metabolic activity was more active in minced tissues than total homogenates. The activity of progesterone $5{\alpha}-reductase(s)$ was increased during postnatal periods(between 5 and 14 days after birth) and thereafter steadily decreased up to the one-fourth level of the fetus. When $5{\alpha}-dihydroprogesterone$ was incubated with brain tissues of various ages, the change in the activity of $3{\alpha}-hydroxysteroid$ oxidoreductase$(3{\alpha}-HSOR)$ was similar to that of $5{\alpha}-reductase(s)$. These results suggest that the reduced formation of total $5{\alpha}-reduced$metabolites was due to the decreased activities of $5{\alpha}-reductase(s)$ and $3{\alpha}-HSOR$. However the level of $3{\beta}-HSOR$ remained constant regardless of the age.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.345-351
• /
• 2002

The purpose of this study was to assess clinical proton MR spectroscopy (MRS) as a noninvasive method for evaluating brain tumor malignancy at 3T high field system. Using 3T MRI/MRS system, localized water-suppressed single-voxe1 technique in patients with brain tumors was employed to evaluate spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cr) and lactate. On the basis of Cr, these peak areas were quantificated as a relative ratio. The variation of metabolites measurements of the designated region in 10 normal volunteers was less than 10%. Normal ranges of NAA/Cr and Cho/Cr ratios were 1.67${\pm}$018 and 1.16${\pm}$0.15, respectively. NAA/Cr ratio of all tumor tissues was significantly lower than that of the normal tissues (p=0.005), but Cho/Cr ratio of all tumor tissue was significantly higher (p=0.001). Cho/Cr ratio of high-grade gliomas was significantly higher than that of low-grade gliomas (P=0.001). Except 4 menigiomas, lactate signal was observed in all tumor cases. The present study demonstrated that the neuronal degradation or loss was observed in all tumor tissues. Higher grade of brain tumors was correlated with higher Cho/Cr ratio, indicating a significant dependence of Cho levels on malignancy of gliomas. Our results suggest that clinical proton MR spectroscopy could be useful to predict tumor malignancy.

• Journal of Ginseng Research
• /
• v.47 no.4
• /
• pp.552-560
• /
• 2023

Background: Ginseng Radix (Panax ginseng Meyer, Araliaceae) has been used medicinally to treat the brain and nervous system problems worldwide. Recent studies have revealed physiological effects that could potentially benefit cognitive performance or mood. The present study aimed to investigate the antidepressant effects of Korean red ginseng water extract (KGE) and its active component in an unpredictable chronic mild stress (UCMS)-induced animal model and elucidate the underlying mechanisms. Methods: The antidepressant potential of the UCMS model was evaluated using the sucrose preference test and open field tests. The behavioral findings were further corroborated by the assessment of neurotransmitters and their metabolites from the prefrontal cortex and hippocampus of rats. Three doses of KGE (50, 100, and 200 mg/kg) were orally administered during the experiment. Furthermore, the mechanism underlying the antidepressant-like action of KGE was examined by measuring the levels of brain-derived neurotrophic factor (BDNF)/CREB, nuclear factor erythroid 2-related factor 2 (Nrf2), and Kelch-like ECH-associated protein 1 (Keap1) proteins in the prefrontal cortex of UCMS-exposed rats. Results: KGE treatment normalized UCMS-induced depression-related behaviors. Neurotransmitter studies conducted after completing behavioral experiments demonstrated that KGE caused a reduction in the ratio of serotonin and dopamine, indicating a decrease in serotonin and dopamine turnover. Moreover, the expression of BDNF, Nrf2, Keap1 and AKT were markedly increased by KGE in the prefrontal cortex of depressed rats. Conclusion: Our results provide evidence that KGE and its constituents exert antidepressant effects that mediate the dopaminergic and serotonergic systems and expression of BDNF protein in an animal model.

• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.4
• /
• pp.367-376
• /
• 1997

The effect of an organic peroxide, t-butylhydroperoxide (t-BHP), on glutamate uptake was studied in synaptosomes prepared from cerebral cortex. t-BHP inhibited the $Na^+-dependent$ glutamate uptake with no change in the $Na^+-independent$ uptake. This effect of t-BHP was not altered by addition of $Ca^{2+}$ channel blockers (verapamil, diltiazem and nifedipine) or $PLA_2$ inhibitors (dibucaine, butacaine and quinacrine). However, the effect was prevented by iron chelators (deferoxamine and phenanthroline) and phenolic antioxidants (N,N'-diphenyl-phenylenediamine, butylated hydroxyanisole, and butylated hydroxytoluene). At low concentrations (＜1.0 mM), t-BHP inhibited glutamate uptake without altering lipid peroxidation. Moreover, a large increase in lipid peroxidation by $ascorbate/Fe^{2+}$ was not accompanied by an inhibition of glutamate uptake. The impairment of glutamate uptake by t-BHP was not intimately related to the change in $Na^+-K+-ATPase$ activity. These results suggest that inhibition of glutamate uptake by t-BHP is not totally mediated by peroxidation of membrane lipid, but is associated with direct interactions of glutamate transport proteins with t-BHP metabolites. The $Ca^{2+}$ influx through $Ca^{2+}$ channel or $PLA_2$ activation may not be involved in the t-BHP inhibition of glutamate transport.

• Biomolecules & Therapeutics
• /
• v.20 no.5
• /
• pp.482-486
• /
• 2012

Cerebral monoamines play important roles as neurotransmitters that are associated with various stressful stimuli. Some components such as ginsenosides (triterpenoidal glycosides derived from the Ginseng Radix) may interact with monoamine systems. The aim of this study was to determine whether ginsenoside Rb1 can modulate levels of the monoamines such as dihydroxyphenylalanine (DOPA), dopamine (DA), norepinephrine (NE), epinephrine (EP), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydorxytryptamine (5-HT), 5-hydroxindole-3-acetic acid (5-HIAA), and 5-hydroxytryptophan (5-HTP) in mice frontal cortex and cerebellum in response to immobilization stress. Mice were treated with ginsenoside Rb1 (10 mg/kg, oral) before a single 30 min immobilization stress. Acute immobilization stress resulted in elevation of monoamine levels in frontal cortex and cerebellum. Pretreatment with ginsenoside Rb1 attenuated the stress-induced changes in the levels of monoamines in each region. The present findings showed the anti-stress potential of ginsenoside Rb1 in relation to regulation effects on the cerebral monoaminergic systems. Therefore, the ginsenoside Rb1 may be a useful candidate for treating several brain symptoms related with stress.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.2
• /
• pp.184-188
• /
• 2013

In the continued search for inhibitors of enoyl-acyl carrier protein (ACP) reductase, we found that four acylbenzenediol sulfate metabolites from Streptomyces sp. AN1761 potently inhibited bacterial enoyl-ACP reductases of Staphylococcus aureus, Streptococcus pneumoniae, and Mycobacterium tuberculosis. Their structures were identified as panosialins A, B, wA, and wB by MS and NMR data. They showed stronger inhibition against S. aureus FabI and S. pneumoniae FabK with $IC_{50}$ of 3-5 ${\mu}M$ than M. tuberculosis InhA with $IC_{50}$ of 9-12 ${\mu}M$. They also exhibited a stronger antibacterial spectrum on S. aureus and S. pneumoniae than M. tuberculosis. In addition, the higher inhibitory activity of panosialin wB than panosialin B on fatty acid biosynthesis was consistent with that on bacterial growth, suggesting that they could exert their antibacterial activity by inhibiting fatty acid synthesis.