• Biomolecules & Therapeutics
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• v.3 no.4
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• pp.294-300
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• 1995

DA-3002, an authentic recombinant human growth hormone(rhGH), was examined for mutagenicity in the reverse mutation test on bacteria, in the chromosomal aberration test on cultured mammalian cells and in the micronucleous test on mice. The reverse mutation test was performed by a plate incorporation method with or without a metabolic activation system(S9 Mix) using Salmonella typhimurium strain TA100, TA1535, TA98 and TA1537. DA-3002 did not significantly increase revertant colonies in any of the test strains under any conditions at dose levels ranging from 0.0125 to 0.4 IU/plate, compared with the vehicle control. In the chromosomal aberration test using cultured Chinese hamster lung(CHL) cells, DA-3002 did not increase the number of aberrant cells in the presence or absence of S9 mix at concentrations of 0.0125 IU/mι to 0.4 IU/mι, compared with the vehicle control. In the micronucleus test, male ICR mice were given DA-3002 intraperitoneally at a dose level of 20, 40 and 80 lU/kg. The incidence of bone marrow micronucleated polychromatic erythrocytes in the DA-3002 treated mice did not differ from that of the vehicle control. These results indicate that DA-3002 doesn't have mutagenic potential under the present test conditions.

• Korean Journal of Veterinary Research
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• v.31 no.3
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• pp.259-264
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• 1991

The proteins of the race horse erythrocyte membrane were analysed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate(SDS-PAGE), and their relations to the fast erythrocyte sedimentation rate(ESR) of the race horse were investigated. The erythrocyte sedimentation rate of race horse were very fast compared with the human one(33 times <$90^{\circ}-plastic-ESR/30m$> and 25 times <$90^{\circ}-micro-ESR/30m$> as fast as the human one) are reported previously. Although the general protein profiles of the race horse erythrocyte membranes were almost similar to that of human, band 3 content was showing higher in race horse (34.7%) than in human (25.3%). The glycoprotein profiles of the race horse erythrocyte membranes revealed by periodic acid Schiff's(PAS) stain showed a marked difference from that of human. The PAS-1(glycophorin) and PAS-2(sialoglycoprotein) present in human erythrocyte memo brane were almost absent from the Holstein and race horse erythrocyte membranes, but PAS-2 was more in only race horse from that of human. Instead, the bovine erythrocyte membranes showed a strong PAS-B near the origin of the electrophorograms and the race horse erythrocyte membranes showed a strong PAS-negative band near the end of the electrophorograms, which is named as PAS-E in this study. These results suggest that the fast sedimentation rate of race horse erythrocyte is due in part to the presence of more band 3 protein fraction and PAS-E glycoproteins in the race horse erythrocytes.

• The Korean Journal of Physiology
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• v.23 no.1
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• pp.23-34
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• 1989

Gentamicin (GM) is a polybasic, aminoglycoside antibiotic used frequently for the treatment of serious gram-negative infections. The major limiting factors in the clinical use of GM as well as other aminoglycoside antibiotics are their nephrotoxicity and ototoxicity. The primary mechanism of cell injury in aminoglycoside toxicity appears to be the disruption of normal membrane function and the inhibition of $Na^{+}-K^{+}$ ATPase activity. There are both indirect and direct evidences which suggests that the effect of aminoglycoside antibiotics on $Na^{+}-K^{+}$ ATPase may explain, or contribute to, their toxicity. It has been shown that aminoglycoside reduce total ATPase activity (Kaku et al., 1973) and $Na^{+}-K^{+}$ ATPase activity (linuma et al., 1967) in the stria vascularis and spiral ligament of the guinea-pig cochlea. Lipsky and Lietman (1980) reported that aminoglycoside antibitoics inhibited the activity of $Na^{+}-K^{+}$ ATPase in microsomal fractions of the cortex and medulla of the guinea-pig kidney, isolated rat renal tubule and human erythrocyte ghosts. The present invstigation was undertaken to elucidate the mechanism of GM on human erythrocytes by examining its effect on $Na^{+}-K^{+}$ ATPase activity, actives sodium and potassium transport across red blood cell and $^{3}H-ouabain$ binding to red blood cell membranes. The results obtained are summarized as follows: 1) CM inhibited significantly both the activity of total ATPase and $Na^{+}-K^{+}$ ATPase at all concentrations tested. 2) GM inhibited active $^{22}Na$ efflux across red blood cell. When ouabain is present, the rate of $^{22}Na$ efflux was completely inhibited. When both GM and ouabain were added, the inhibitory effect of active $^{22}Na$ efflux was more pronounced. 3) Active $^{86}Rb$ influx was inhibited significantly by GM. In the presence of ouabain, the rate of $^{86}Rb$ influx is markedly inhibited. But $^{86}Rb$ influx is not appreciably altered by the presence of both GM and ouabain. 4) In the presence of GM, $^{3}H-ouabain$ binding to red blood cell membrane increased. From the above results, it may be concluded that the inhibition of active sodium and potassium transport across red blood cell by gentamicin appears to be due to the inhibition of $Na^{+}-K^{+}$ ATPase activity and an increase in ouabain binding to red blood cell membranes.

• Biomedical Science Letters
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• v.12 no.1
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• pp.17-22
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• 2006

The baculovirus expression system is a powerful method for producing large amounts of the human erythrocyte-type glucose transport protein, heterologously. Characterization of the expressed protein is expected to show its ability to transport sugars directly. To achieve this, it is a prerequisite to know the properties of the endogenous sugar transport system in Spodoptera frugiperda Clone 21 (Sf21) cells, which are commonly employed as a host permissive cell line to support the baculovirus replication. The Sf21 cells can grow well on TC-100 medium that contains 0.1% D-glucose as the major carbon source, strongly suggesting the presence of endogenous glucose transport system. However, unlike the human glucose transport protein that has a broad substrate and inhibitor specificity, very little is known about the nature of the endogenous sugar transport system in Sf21 cells. In order to characterize further the inhibitor recognition properties of the Sf21 cell transporter, the ability of phloretin, cytochalasin B and D-fructose to inhibit 2-deoxy-D-glucose (2dGlc) transport was examined by measuring inhibition constants $(K_i)$. The $K_i's$ for reversible inhibitors were determined from plots of uptake versus inhibitor concentration. The 2dGlc transport in the Sf21 cells was very potently inhibited by phloretin, the aglucone of phlorizin with a $K_i$ similar to the value of about $2{\mu}M$ reported for inhibition of glucose transport in human erythrocytes. However, the Sf21 cell transport system was found to differ from the human transport protein in being much less sensitive to inhibition by cytochalasin B (apparent $K_i$ approximately $10\;{\mu}M$). In contrast, It is reported that the inhibitor binds the human erythrocyte counterpart with a $K_d$ of approximately $0.12\;{\mu}M$. Interestingly, the Sf21 glucose transport system also appeared to have high affinity for D-fructose with a $K_i$ of approximately 5mM, contrasting the reported $K_m$ of the human erythrocyte transport protein for the ketose of 1.5M.

• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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• pp.127-132
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• 1992

Colloidal $^{32}P$ chromic phosphate is used to prevent hepatic metastasis from colorectal cancer. It is speculated that the intravenous injection of colloidal $^{32}P$ chromic phosphate can cause genotoxicity. To evaluate the genotoxicity of intravenously injected colloidal $^{32}P$ chromic phosphate, authors performed a micronuclei test in mice bone marrow. Mice (ICR strain, $25\sim30g$) were divided to 4 groups: control, group 1 (19.166 KBq/g, usual therapeutic dose in human), group 2 (191.66 KBq/g), and group 3 (1916.6 KBq/g). Five mice of each group were sacrificed at days 1, 2, 3, 5, 7 and 14. Bone marrow were smeared and stained with Wright-Giemsa method. One thousand polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) were counted under the light microscope, and the number of micronucleated PCEs and NCEs were recorded. The frequency of micronuclei in PCE and NCE in the control group was $0.3{\pm}0.06%\;and\;0.45{\pm}0.10%$, respectively. At group 1, frequency of micronuclei is not different from the control. However, frequencies of micronuclei in PCE at groups 2 and 3 were significantly increased from day 1 and persisted to day 14. The frequency of micronuclei in NCE was increased only at group 3. In conclusion, the frequency of micronuclei increases as the dose of colloidal $^{32}P$chromic phosphate increases, while micronuclei was not induced at the usual therapeutic dose. And the frequency of micronuclei persistently elevated for 14 days in the cases of higer doses.

• Molecules and Cells
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• v.37 no.8
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• pp.592-597
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• 2014

The cell membrane provides critical cellular functions that rely on its elaborate structure and organization. The structure of turtle membranes is an important part of an ongoing study of erythrocyte membranes. Using a combination of atomic force microscopy and single-molecule force spectroscopy, we characterized the turtle erythrocyte membrane structure with molecular resolution in a quasi-native state. High-resolution images both leaflets of turtle erythrocyte membranes revealed a smooth outer membrane leaflet and a protein covered inner membrane leaflet. This asymmetry was verified by single-molecule force spectroscopy, which detects numerous exposed amino groups of membrane proteins in the inner membrane leaflet but much fewer in the outer leaflet. The asymmetric membrane structure of turtle erythrocytes is consistent with the semi-mosaic model of human, chicken and fish erythrocyte membrane structure, making the semi-mosaic model more widely applicable. From the perspective of biological evolution, this result may support the universality of the semi-mosaic model.

• Biomolecules & Therapeutics
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• v.6 no.1
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• pp.56-62
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• 1998

Mutagenicity of recombinant human erythropoietin (rhEPO) was examined in the reverse mutation test on bacteria, in the chromosomal aberration test on cultured mammalian cells and in the micronucleus test on mice. The reverse mutation test was performed by a plate incorporation method with or wothout a metabolic activation system (59 Mix) using Salmonella typhimurium strain TA100, TA1535, TA98 and TA 1537. The rhEPO did not significantly increase revertant colonies in any of the test strains under any conditions at dose levels ranging from 1000 H/ml to 62.5 lu/plate, compared with the vehicle control. In the chromosomal aberration test using cultured Chinese Hamster Lung (CHL) cells, the number of aberrant cells was not increased in the presence or absence of 59 Mix at concentrations of 1000 lU/ml to 250 lU/ml, compared with the vehicle control. In the micronucleus test, male ICR mice were given rhEPO intraperitoneally at a dose level of 25000, 12500 and 6250 lU/kg. The incidence of bone marrow micronucleated polychromatic erythrocytes was not different from that of the vehicle control. From these results, rhEPO is considered to be non-mutagenic under the present test conditions.

• Parasites, Hosts and Diseases
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• v.48 no.1
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• pp.15-21
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• 2010

Astrocytes are the most abundant cells in the central nervous system that play roles in maintaining the blood-brain-barrier and in neural injury, including cerebral malaria, a severe complication of Plasmodium falciparum infection. Prostaglandin (PG) $D_2$ is abundantly produced in the brain and regulates the sleep response. Moreover, $PGD_2$ is a potential factor derived from P. falciparum within erythrocytes. Heme oxygenase-1 (HO-1) is catalyzing enzyme in heme breakdown process to release iron, carbon monoxide, and biliverdin/bilirubin, and may influence iron supply to the P. falciparum parasites. Here, we showed that treatment of a human astrocyte cell line, CCF-STTG1, with $PGD_2$ significantly increased the expression levels of HO-1 mRNA by RT-PCR. Western blot analysis showed that $PGD_2$ treatment increased the level of HO-1 protein, in a dose- and time-dependent manner. Thus, $PGD_2$ may be involved in the pathogenesis of cerebral malaria by inducing HO-1 expression in malaria patients.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1192-1195
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• 2010

To investigate the influence of the N- or C-terminal regions of pleurocidin (Ple) peptide on antifungal activity, four analogs partially truncated in the N- or C-terminal regions were designed and synthesized. Circular dichroism (CD) spectroscopy demonstrated that all the analogs maintained an alpha-helical structure. The antifungal susceptibility testing also showed that the analogs exhibited antifungal activities against human fungal pathogens, without hemolytic effects against human erythrocytes. The result further indicated that the analogs had discrepant antifungal activities [Ple>Ple (1-22)>Ple (4-25)>Ple (1- 19)>Ple (7-25)] and that N-terminal deletion affected the activities much more than C-terminal deletion. Hydrophobicity [Ple>Ple (1-22)>Ple (4-25)>Ple (1-19)> Ple (7-25)] was thought to have been one of the consistent factors that influenced these activity patterns, rather than the other primary factors like the helicity [Ple>Ple (4-25) >Ple (1-22)>Ple (1-19)>Ple (7-25)] or the net charge [Ple=Ple (4-25)=Ple (7-25)>Ple (1-22)=Ple (1-19)] of the peptides. In conclusion, the hydrophobic amino acids in the N-terminal region of Ple is more crucial for antifungal activity than those in the C-terminal region.

• Microbiology and Biotechnology Letters
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• v.38 no.1
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• pp.19-23
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• 2010

Recently, marine organisms are emerging as a leading group for identifying and extracting novel bioactive substances. These substances are known to possess a potential regarding not only as a source of pharmaceutical products but also their beneficial effects on humans. Among the substances, antimicrobial peptides (AMPs) specifically have attracted considerable interest for possible use in the development of new antibiotics. AMPs are characterized by relatively short cationic peptides containing the ability to adopt a structure in which cationic or hydrophobic amino acids are spatially scattered. Although a few reports address novel marine organisms-derived AMPs, their antimicrobial mechanism(s) are still remain unknown. In this review, we summarized the peptides previously investigated, such as Pleurocidin, Urechistachykinins, Piscidins and Arenicin-1. These peptides exhibited significant antimicrobial activities against human microbial pathogens without remarkable hemolytic effects against human erythrocytes, and their mode of actions are based on permeabilization of the plasma membrane of the pathogen. Therefore, the study of antimicrobial peptides derived from marine organisms may prove to be useful in the design of future therapeutic antimicrobial drugs.