• Applied Microscopy
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• v.13 no.1
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• pp.13-30
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• 1983

[ $1-{\beta}-D-Arabinofuranosylcytosine$ ](ara-C), which is a pyrimidine nucleoside analog is cytotonic to mammalian cells in culture and is active in vitro and in vivo against a variety of DNA viruses. The precise mechanism of action of ara-C has not been determined, although ara-C is thought to act as an antimetabolite, interfering with the synthesis of deoxyribonucleic acid(DNA). Cytosine arabinoside originally seemed to act principally by inhibiting the conversion of cytidine to deoxytidine, thus inhibiting DNA synthesis. But recent data suggest that effects upon DNA polymerase and effects via incorporation into DNA and RNA may well be of equal importance. The author have demonstrated the effect of cytosine arabinoside on the hepatocytes of albino mice treated with ara-C, observing changes in the cytoplasmic organelles of the hepatocytes. A total of 120 healthy male albino mice were divided into the control and ara-C treated groups. The animals of the ara-C group were given 10mg. per kg of body weight of mouse ara-C in physiological saline solution and the animals of control group were given physiological saline solution, intraperitoneally. After an administration of ara-C or physiological saline solution, the animal were killed at. interval of 6, 12, and 24 hours. The specimens, which were obtained from the left anterier lobe of the liver, were stained with uranyl acetate and lead citrate and observed with JEM 100B electron microscope. The results were obtained as follow: A pronounced dilatation, sacculation and fragmentation of the cisterane of rough endoplasmic reticulum with dissociation of membrane bound-ribosomes, disaggregation of free ribosomes in the cytoplasm, proliferation of the smooth endoplasmic reticulum associated with depletion of glycogen paracles, atrophies of Golgi complex, production of numerous lipid droplets, and formation of antophagic vacuoles, multivesicular bodies and residual bodies are recognized in the hepatocytes of ara-C treated mice. Consequently it is suggested that cytosine arabinoside would induce a changes of the cytoplasmic organelles of the hepatocytes in albino mice.

• Applied Microscopy
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• v.21 no.1
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• pp.63-76
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• 1991

Butylated hrdroxyanisole(BHA), a widely used food additive phenolic antioxidant, is known to inhibit cancer formations inducible with a wide variety of chemical carcinogens including aflatoxin $B_1(AFB_1)$. Thus, in the present study morphological characteristics underlying the hepatoprotective effects of BHA against $AFB_1$ inducible ultrastructural changes of hepatocytes have been examined. The obtained results are as follows : 1 . Livers obtained from rats treated with $AFB_1$ in vivo have been examined with transmission electron microscope. Among the many hepatocellular structural aberrations induced by $AFB_1$ treatment, the nuclear chromatins were found to be distributed irregularly('cap formation') and the nuclear membrane was found to be partially segregated. Furthermore, there were many lipid droplets, hyperplasia of smooth endoplasmic reticulum, dialated rough endoplasmic reticulum and, lysosomes arrested at various stages of its development. 2. Also, when $AFB_1$ was given in vitro to hepatocytes which have been isolated from untreated normal rats and examined under scanning electron microscope, there were much 'blobbing' phenomena resulting from cytoskeletal disturbances. 3. However, in the liver obtained from rats pretreated with BHA and then give the $AFB_1$, the observed morphological aberrations were in much reduced extent. Similarly, the BHA-hepatocytes had much decreased severity in the $AFB_1$ inducible blob formations.

• Korean Journal of Veterinary Research
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• v.25 no.2
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• pp.125-131
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• 1985

철분투여가 용혈성 빈혈에 미치는 영향을 알아보기 위하여 흰쥐의 사료내에 철분을 혼합급여 또는 근육내에 주사하면서 60일간 사육하고 체중은 10일 간격으로 측정하였으며 적혈구의 취약성 실험과 적혈구막 및 혈장내의 vitamin E 함량과 인지질의 함량을 비색방법으로 측정한 결과 다음과 같은 성적을 얻었다. 증체량 측정에서는 A군의 190g에 비하여 C군 155g, B군 142g, D군 112g으로 철분함량이 높은 군에서 낮은 증가를 보였으며 적혈구 취약성 실험 결과 5마리 암수 평균값이 각각 A군 7.63% 및 2.68%, C군 10.84% 및 16.75%, B군 25.54% 및 33.62%, D군 47.23% 및 38.35%로 철분함량에 비례하여 각 실험군 사이에 유의한 증가를 나타내었다. 또한 적혈구막의 vitamin E 및 인지질의 함량은 5마리 암수 평균값이 각각 A군에서 18.54mg/dl 및 17.43mg/dl 그리고 120.55mg/dl 및 113.94mg/dl, C군에서 14.99mg/dl 및 10.56mg/dl 그리고 108.54mg/dl 및 99.97mg/dl, B군에서 13.10mg/dl 및 11.02mg/dl 그리고 91.67mg/dl 및 87.45mg/dl, D군에서 6.86mg/dl 및 8.87mg/dl 그리고 79.78mg/dl 및 70.12mg/dl로서 철분 투여량에 비례적으로 감소하였다. 혈장내의 vitamin E 및 인지질의 함량은 A군, C군, B군, D군의 순으로 각각 함량이 2.51mg/dl 및 31mg/dl, 1.94mg/dl 및 21mg/dl, 1.37mg/dl 및 20mg/dl 그리고 1.37mg/dl 및 15mg/dl로 철분 투여량에 비례적으로 감소하는 경향을 나타내었다.

• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.1-7
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• 2017

Parkinson's disease (PD) is an irreversible neurological disorder with related locomotor dysfunction and is characterized by the selective loss of nigral neurons. PD can be experimentally induced by 6-hydroxydopamine (6-OHDA). It has been reported that reactive oxygen species, which deplete endogenous glutathione (GSH) levels, may play important roles in the dopaminergic cell death characteristic of PD. Fucoidan, a sulfated algal polysaccharide, exhibits anti-inflammatory and anti-oxidant actions. In this study, we investigated whether fucoidan can protect against 6-OHDA-mediated cytotoxicity in SH-SY5Y cells. Cytotoxicity was evaluated by using MTT and LDH assays. Fucoidan alleviated cell damage evoked by 6-OHDA dose-dependently. Fucoidan reduced the number of apoptotic nuclei and the extent of annexin-V-associated apoptosis, as revealed by DAPI staining and flow cytometry. Elevation of lipid peroxidation and caspase-3/7 activities induced by 6-OHDA was attenuated by fucoidan, which also protected against cytotoxicity evoked by buthionine-sulfoximine-mediated GSH depletion. Reduction in the glutathione/glutathione disulfide ratio induced by 6-OHDA was reversed by fucoidan, which also inhibited 6-OHDA-induced disruption of mitochondrial membrane potential. The results indicate that fucoidan may have protective action against 6-OHDA-mediated neurotoxicity by modulating oxidative injury and apoptosis through GSH depletion.

• Molecules and Cells
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• v.38 no.11
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• pp.1013-1021
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• 2015

Most of the axons in the vertebrate nervous system are surrounded by a lipid-rich membrane called myelin, which promotes rapid conduction of nerve impulses and protects the axon from being damaged. Multiple sclerosis (MS) is a chronic demyelinating disease of the CNS characterized by infiltration of immune cells and progressive damage to myelin and axons. One potential way to treat MS is to enhance the endogenous remyelination process, but at present there are no available treatments to promote remyelination in patients with demyelinating diseases. Sulfasalazine is an anti-inflammatory and immune-modulating drug that is used in rheumatology and inflammatory bowel disease. Its anti-inflammatory and immunomodulatory properties prompted us to test the ability of sulfasalazine to promote remyelination. In this study, we found that sulfasalazine promotes remyelination in the CNS of a transgenic zebrafish model of NTR/MTZ-induced demyelination. We also found that sulfasalazine treatment reduced the number of macrophages/microglia in the CNS of demyelinated zebrafish larvae, suggesting that the acceleration of remyelination is mediated by the immunomodulatory function of sulfasalazine. Our data suggest that temporal modulation of the immune response by sulfasalazine can be used to overcome MS by enhancing myelin repair and remyelination in the CNS.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.68-68
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• 2003

HP(2-20) (AKKVFKRLEKLEKLFSKIQNDK) derived from the N-terminus of Helicobacter pylori Ribosomal Protein L1 shows potent antimicrobial activity against bacterial, fungi and cancer cells without cytotoxic effect. In order to investigate the relationships between antimicrobial activity and the structures, several analogues have been designed and synthesized. The structures of these peptides in SDS micelles have been investigated using NMR spectroscopy and they revealed that analogue 3 has the longest, well-defined alpha-helix from Val5 to Trp19. NOESY experiments performed on HP and its analogues in nondeuterated SDS micelles show that protons in the indole ring of Trp16 are in close contact with methylene protons of SDS micelles. In order to probe the position of HP and its analogues relative to the SDS micelles, spin-labeled stearate was added. Large effects are observed for the chemical shifts and the intensities of Phe5, Glu9, Phe12, and Trp16 within the helix region by 16-doxylstearate. This result implies that 16-doxylstearate is located in the center of the micelles and the hydrophobic phase of the amphiphilic ${\alpha}$-helix is located in contact with the acyl chains of the micelles. Also, Lys3 and Lys4 at N-terminus and Lys20 at C-terminus may produce an optimal arrangement for electrostatic interactions between the sulfate head groups of the SDS and the positively charged lysyl N$\sub$3/$\^$+/. Interactions between the indole ring of Trp and the membrane, as well as the amphiphilic ${\alpha}$-helical structure of HP induced by Trp at the C-terminus may allow HP to span the lipid bilayer. These structural features are crucial for their potent antibiotic activities.

• Bulletin of the Korean Chemical Society
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• v.24 no.10
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• pp.1478-1484
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• 2003

CRAMP was identified from a cDNA clone derived from a mouse femoral marrow cells as a member of cathelicidin-derived antimicrobial peptide. Tertiary structure of CRAMP in TFE/$H_2O$ (1 : 1, v/v) solution has been determined by NMR spectroscopy previously and consists of two amphipathic $\alpha-helices$ from Leu4 to Lys10 and from Gly16 to Leu33. These two helices are connected by a flexible region from Gly11 to Gly16. Analysis of series of fragments composed of various portion of CRAMP revealed that an 18-residue fragment with the sequence from Gly16 to Leu33 (CRAMP-18) was found to retain antibacterial activity without cytotoxicity. The effects of two Phe residues at positions 14 and 15 of CRAMP-18 on structure, antibacterial activity, and interaction with lipid membranes were investigated by $Phe^{14,15}$ ${\rightarrow}$ Ala substitution (CRAMP-18-A) in the present study. Substitution of Phe with Ala in CRAMP-18 caused a significant reduction on antibacterial and membrane-disrupting activities. Tertiary structures of CRAMP-18 in 50% TFE/$H_2O$ (1 : 1, v : v) solution shows amphipathic ${\alpha}$-helix, from $Glu^2{\;}to{\;}Leu^{18}$, while CRAMP-18-A has relatively short amphipathic ${\alpha}$-helix from $Leu^4{\;}to{\;}Ala^{15}$. These results suggest that the hydrophobic property of $Phe^{14}{\;}and{\;}Phe^15$ in CRAMP-18 is essential for its antibacterial activity, ${\alpha}$-helical structure, and interactions with phospholipid membranes.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.108-114
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• 2007

The lyotropic behaviors to form the structure of distearoylphosphatidylcholine (DSPC)-based liquid crystal (LC) hydrated by only propylene glycol (PG) without water were examined by differential scanning calorimetry (DSC), X-ray diffractions (XRD), polarized microscope (PM) and transmission electron microscope (TEM). By increasing the amount of PG instead of water, it showed the phase transition to be gradually changed from anisotropic structures to other structures more close to isotropic ones and their appearance to be changed from solid-like states to liquid-like ones with more fluidity. Below 50% w/w PG, the mixtures of DSPC and PG resulted in no direct observation of LC structure through PM because they were very close to solid-states. From 55% w/w to 90% w/w of PG, the dense lamella crystalline structures were observed through PM, and their thickness and area decreased as the content of PG increased. Measured by DSC with heating process, the main phase transition from α -lamella phase to isotropic phase appeared from 52.89 °C to 47.41 °C to show linearly decreasing behaviors because PG affects the hydrophobic region of DSPC-based lamella phase. The repeating distance of the lamella phase and the interlayer distance between bilayers were calculated with XRDs and the average number of bilayers related to the thickness in LC structure was approximately estimated by combining with TEM results. The WAXS and DSC measurements showed that all of PG molecules contributed to swelling both the lipid layer in the edge region of lamella phase close to phosphate groups and the interlayer between bilayers below 90% w/w of PG. The phase and thermal behaviors were found to depend on the amount of PG used by means of dissolving DSPC as a phospholipid and rearranging its structure. Instead of water, the inducement of PG as a polar solvent in solid-lamella phase is discussed in terms of the swelling effect of PG for DSPC-based lamella membrane.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.2
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• pp.119-127
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• 2018

Veterinary antibiotics (VAs) has been used to treat animal disease and to increase body weight. However, released VAs in the soil via spreading of compost can transport to plant and affect its growth. Main purpose of this research was i) to monitor VAs concentration in plant and ii) to evaluate inhibition effect of VAs residuals on the plant growth. Red lettuce (Lactuca sativa) was cultivated for 35 days in the pot soil spiked with 3 different concertation (0.05, 0.5, $5.0mg\;kg^{-1}$) of chlortetracycline (CTC) and sulfamethazine (SMZ). After 35 days of cultivation, concentration of CTC and SMZ in the plant was measured. Residual of CTC and SMZ was only quantified at the range of $0.007-0.008mg\;kg^{-1}$ and $0.006-0.017mg\;kg^{-1}$ in the leaf and root respectively when high concentration ($5.0mg\;kg^{-1}$) of antibiotic was spiked in the soil. Leaf length and root mass was statistically reduced when $0.05mg\;kg^{-1}$ of CTC was spiked in the soil while no statistical difference was observed for SMZ treatment. This result might indicated that high $K_{ow}$ and $K_d$ value are the main parameters for inhibiting plant growth. Antibiotics that has a high $K_{ow}$ causing hydrophobicity and easy to bioaccumulate in the lipid cell membrane. Also, antibiotics that has a high $K_d$ properties can be sorbed in the root causing growth inhibition of the plant. Overall, management of VAs should be conducted to minimize adverse effect of VAs in the ecosystem.

• Archives of Pharmacal Research
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• v.25 no.2
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• pp.178-183
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• 2002

A high molecular ar weight water-soluble chitosan (WSC) with an average molecular weight of 300 kD and a deacethylation level of over 90% was produced using a simple multi-step-membrane separation process. It is known that WSC prevents obesity induced by a high-fat diet. Consequently, this study investigated whether or not WSC improved the ovarian dysfunction caused by obesity in mice. The mice were fed a high density protein and lipid diet for weeks, followed by the administration of WSC at 480 mg/kg body weight per day for 4 days. Thereafter, the changes in body weight, ovulation rate, in vivo and in vitro fertilization and emboryonic development were measured . WSC markedly reduced the body weight of obese mice fed with a high-fat diet, but not in mice fed with a normal diet. WSC had siginificant effects on the ovulation rate, both the in vivo and in vitro fertilization rates and embryonic development. These results indicate an improvement in the ovarian and oviduct dysfunction caused by obesity, and suggest an adjustment in the internal secretions and metabolic functions.