• BMB Reports
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• v.41 no.5
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• pp.345-352
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• 2008

The cerebral microvessels possess barrier characteristics which are tightly sealed excluding many toxic substances and protecting neural tissues. The specialized blood-neural barriers as well as the cerebral microvascular barrier are recognized in the retina, inner ear, spinal cord, and cerebrospinal fluid. Microvascular endothelial cells in the brain closely interact with other components such as astrocytes, pericytes, perivascular microglia and neurons to form functional 'neurovascular unit'. Communication between endothelial cells and other surrounding cells enhances the barrier functions, consequently resulting in maintenance and elaboration of proper brain homeostasis. Furthermore, the disruption of the neurovascular unit is closely involved in cerebrovascular disorders. In this review, we focus on the location and function of these various blood-neural barriers, and the importance of the cell-to-cell communication for development and maintenance of the barrier integrity at the neurovascular unit. We also demonstrate the close relation between the alteration of the blood-neural barriers and cerebrovascular disorders.

• Journal of Pharmaceutical Investigation
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• v.5 no.1
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• pp.28-40
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• 1975

Polyporus would used as diuretics. Then, for the purpose of experimentally certifying the above mention, the effect on the renal function of dog was investigated, utilizing clearance technique. Water and alcohol extracts, when injected intravenously, produced significant increases of urinary sodium and potassium, osmolar and free water clearances, and urine flow, while glomerular filtration rate and renal plasma flow remained unchanged. During diuresis produced by furosemide, addition of water extract reduced the action of furosemide and markedly renal plasma flow. It would appear that these compounds are capable of action by a different mechanism or a different site. water extract, when infused directly into a renal artery, reduced the urine flow of experimental kidney as well as renal plasma flow, and the contralateral kidney exhibited diuresis, whereas amounts of sodium and potassium excreted in urine increased on both kidney. It is surmised from those observations that Polyporus induces diuresis by inhibition the reabsorptive mechanism of renal tubules through some endogeneous humoral substances, in addition, directly reduces the renal plasma flow.

• Journal of the Korean Chemical Society
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• v.67 no.3
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• pp.181-190
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• 2023

Melanoma is a malignant skin tumor caused by damage to melanocytes that can spread to other organs. Hence, various studies have been conducted on preventing the spread of melanoma. Flavonoid-structured substances such as apigenin and galanzin are effective therapeutic agents for inhibiting the proliferation and metastasis of melanoma. In this study, luteolin, quercetin, and their respective derivatives were synthesized. These compounds inhibited cell proliferation of B16 melanoma cells. These results confirmed that the derivatives of quercetin and luteolin may be useful as therapeutic agents to prevent melanoma metastasis.

• YAKHAK HOEJI
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• v.49 no.4
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• pp.347-354
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• 2005

Lipopolysaccharide (LPS) induces synthesis of several inflammatory cytokines and nitric oxide (NO). NO in brain is involved not only in the regulation of important metabolic pathways via intracellular cyclic GMP-dependent path­ways, but also in neurotoxic damage by reacting with superoxide ion leading to form peroxynitrite radical. Oxidative stress has suggested to be related to the inhibition of NO synthase/cyclic GMP pathway. OQ21 is a new fluorinated quinone compound that is recently known to have inhibitory effects on both NO synthase (NOS) and guanylyl cyclase (GC). In this study, we examined effects of OQ21, other known NOS or GC inhibitors, or an antioxidant, melatonin, on the oxidative stress produced by LPS in rat brain. Oxidative stress was observed by using the 2',7'-dichlorofluorescin diacetate to measure intra-cellular reactive oxygen species (ROS) production and by measuring the formation of thiobarbituric acid reactive substances to measure lipid peroxidation. LPS induced significant increase in both ROS produdction and lipid peroxidation in all brain regions tested (striatum, hippocampus and cortex), which were dissected 6hr after intraperitoneal administration of LPS to rats. Direct striatal injection of two NOS inhibitors, N-nitro-L-arginine methyl ester and diphenyleneiodonium, or a GC inhibitor, IH-[1,2,4]oxadiazolo[4,3-a]quinoxaline-l-one, produced no significant ROS increase. However, OQ21 enhanced ROS formation in striatal tissues from LPS-treated rats. Melatonin decreased LPS-induced ROS formation and decreased ROS formation increased by OQ21 in striatum of LPS-treated rats.

• Journal of Ginseng Research
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• v.40 no.3
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• pp.220-228
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• 2016

Background: Among the various ginseng strains, Shizhu ginseng is endemic to China, mainly distributed in Kuandian Manchu Autonomous County (Liaoning Province, China); however, not much is known about the compounds (especially saponins) in Shizhu ginseng. Methods: A rapid, sensitive, and reliable ultra-high performance liquid chromatography coupled with MS/MS (UHPLC-MS/MS) method was developed to separate and identify saponins in Shizhu ginseng. Results: The separation was carried out on a Waters ACQUITY UPLC BEH $C_{18}$ column ($100mm{\times}2.1mm$, $1.7{\mu}m$) with acetonitrile and 0.1% formic acid aqueous solution as the mobile phase under a gradient elution at $40^{\circ}C$. The detection was performed on a Micromass Quattro Micro API mass spectrometer equipped with electrospray ionization source in both positive and negative modes. Under the optimized conditions, a total of 31 saponins were identified or tentatively characterized by comparing retention time and MS data with related literatures and reference substances. Conclusion: The developed UHPLC-MS/MS method was suitable for identifying and characterizing the chemical constituents in Shizhu ginseng, which provided a helpful chemical basis for further research on Shizhu ginseng.

• YAKHAK HOEJI
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• v.10 no.2_3
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• pp.20-24
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• 1966

Pharmacological principles were isolated from Artemisia messer-schmidtiana B$_{ESSER}$ var. viridis B$_{ESSER}$ which has long been used as a cholagogic drug. These substances were identified as esculetin-6-methylether and esculetin-7-methylether and the latter has not yet been found in nature. Both of them possess cholagogic activity.

• YAKHAK HOEJI
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• v.29 no.3
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• pp.117-123
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• 1985

A clorimetric determination method of pyruvic acid using hydroxylamine was studied. Hydroxylamine was reacted with pyruvic acid to form complex compound in the presence of Cu(II) ion. Optimal conditions for the quantitative analysis were investigated and the structure of complex was examined spectrometrically. The molar ratio (2:1) and the stability constant ($1.88{\times}10^{4}$) of the complex were measured. It was the characteristic feature of this method that the commonly encountered interfering substances such as fructose, glucose and lactic acid do not infuence the measurement of pyruvic acid.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.230.2-231
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• 2003

The seaweed, as source of bio-active substances as well as food, has received much attention in recent years. This study was carried out to determine the cytotoxic and chemopreventive effects of Porphyra tenera (PT) and Enteromorpha linza (EL). The PT and EL extracts from methanol were fractionated to five different types, which are hexane, ethylether, ethylacetate, butanol and water. (omitted)

• YAKHAK HOEJI
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• v.10 no.4
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• pp.7-20
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• 1966

1. Of the 32 extracts from Genus of lishenes broth tested for antimicrobial activity, 28 inhibited at least one of the 3 test microorganisms used. 2. Twenty seven lichnes broth from 32 species tested were active against at least one of the Gram-positive bacteria M. pyogenes var, aureus 203 p, and twenty four lichenes broth from 32 Species tested were active against at least one of the Gram-positive bacteria Bacillus subtilis ATCC 6633. 3 Twenty five lichenes broth from 32 species tested were active against at least one of the Gram-negative bacteria Escherichia coli 0.126. 4. The antibiotic substances in lichenes were readily extracted by organic solvents.

• YAKHAK HOEJI
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• v.2 no.1_2
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• pp.48-69
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• 1953

"Kimchi", which is a main side-dish on Korean table is the pickled vegitables with seasoning substances : such as onion red pepper, salt, water and etc. In this paper, the variation of pH, acidity (calculated as lactic acid) and sugar contents (calculated as dextrose) are investigated during the fermentation period of Kimchi and the effects of antiseptics (Brilliant green, malachite green, sodium benzate, salicylic acid, P-dichlor amino sulfonyl-benzoic acid) and hydrochlonic acid to prevent spoiling are studied on the Kimchi which is prepared by a simple method in this laboratory.