• Animal cells and systems
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• v.6 no.4
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• pp.341-347
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• 2002

The life cycle of Acanthamoeba is comprised of two distinct stages, tropho-zoite and cyst. During periods of stress, trophozoites undergo cellular differentiation into cyst. In order to understand the cellular differentiation, ore followed changes in profiles of major proteins by 2D-PAGE and ubiqui-tinated proteins by immunoblotting with anti-ubiquitin (Ub) monoclonal antibody (mAb) as a probe. We observed 51 proteins present in trophozoite were lost with the encystment. We found that 43 proteins within 24 h, and 8 proteins in 96 h of encystment. Among them, 17 proteins were staine with anti-Ub mAb. In cysts, 16 proteins including 2 anti-Ub mAb-reactive proteins were newly synthesized. Four proteins were newly detected in 24 h-cyst and disappeared in 96 h-cyst, one protein was synthesized in 24-96 h-cyst and disappeared in 168 h-cyst, and 11 proteins appeared upon en-cystment and were present in all cyst stages. We identified a cyst specific 33 kDa protein as subtilisin-like serine proteinase by N-terminal sequencing. Identification of these proteins lost and newly synthesized with encystment would improve our understanding of cysting protozoan parasites.

• Animal cells and systems
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• v.9 no.4
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• pp.205-209
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• 2005

A rapid, simple and efficient method to extract RNA from the adult polyps of a soft coral, marine cnidarian, Scleronephthya gracillimum $(K\ddot{u}kenthal)$; was developed in this study. The highest yield and purity of RNA was obtained with the lysis solution containing 35 mM EDTA, 0.7 M LiCl, 7.0% SDS, and 200 mM Tris-Cl (pH 9.0). Approximately $40{\mu}g$ of total RNA was extracted from 200 mg of liquid nitrogen-pulverized polyp tissue. The ratio of absorbance at 260 nm and 280 nm ranged from 1.8 to 2.0. The results of the reverse transcription polymerase chain reaction (RTPCR) with ${\beta}-actin$ gene specific primers and Northern blot analysis using the same gene probe revealed that the RNA extracted by our method had high quality, and was sufficient for subsequent molecular biological analyses. This method was effective for RNA extraction from other soft coral species which belong to the genus Dendronephthya.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1828-1833
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• 2005

The Integration of biological databases is critically important because of the interconnectedness of biological research. But it's not easy to integrate these databases for the different formats and designers in heterogeneous environments. So initial design is indispensable to integrate heterogeneous databases. In this paper, after we performed conceptual modeling on a popular nucleotide database, GenBank and a protein database, Swiss-Prot and integrated them by considering cross-reference. we also propose the integration system architecture called Bio-Gateway System, which can help users query closely linked information between two biological databases within one system differently from existing systems as well as query easily on condition that user knows fine condition for less effort.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.6
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• pp.853-859
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• 2017

Terrorists always threats the global security with the possibility of using prohibited warfare, NBCs(Nuclear, Biological and Chemical Warfare). Compared to other prohibited warfares, most of biological warfare agents (BWAs) have no physical properties and time delays from spread to affect. Therefore the early detection is important to protect and decontaminate from BWAs. On the preliminary detection stage for suspicious material, most of detection kits only serve to know weather the BWAs exists or not. Due to this reason, simple field confirmation testing for suspicious substances have been used to identify materials which show negative result on detection kits. Considering the current Lab on a Chip(LOC) technologies, we suggest simple identification platform for unknown suspicious substances based on paper fluidics. We hope that our research will envision the future direction for the specific point-of-view for LOC technologies on detection strategy of BWAs.

• Korea-Australia Rheology Journal
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• v.15 no.2
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• pp.91-96
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• 2003

The sensitivity of the product to the ongoing sinusoidal disturbances of the process has been investigated in the film casting of viscoelastic polymer fluids using frequency response analysis. As demonstrated for fiber spinning process (Jung et al., 2002; Devereux and Denn, 1994), this frequency response analysis is useful for examining the process sensitivity and the stability of extensional deformation processes including film casting. The results of the present study reveal that the amplification ratios or gains of the process/product variables such as the cross-sectional area at the take-up to disturbances exhibit resonant peaks along the frequency regime as expected for the systems having hyperbolic characteristics with spilt boundary conditions (Friedly, 1972). The effects on the sensitivity results of two important parameters of film casting, i.e., the fluid viscoelasticity and the aspect ratio of the casting equipment have been scrutinized. It turns out that depending on the extension thinning or thickening nature of the fluid, increasing viscoelasticity results in enlargement or reduction of the sensitivity, respectively. As regards the aspect ratio, it has been found that an optimum value exists making the system least sensitive. The present study also confirms that the frequency response method produces results that corroborate well those by other methods like linear stability Analysis and transient solutions response. (Iyengar and Co, 1996; Silagy et al., 1996; Lee and Hyun, 2001).

• Toxicological Research
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• v.12 no.1
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• pp.21-27
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• 1996

Vitamin C has been well known to be a potential chemopreventive agent for several toxic compounds. It reduced the mutation frequencies of 6-sulfooxymethylbenzo[a]pyrene (SMBP) and 6hydroxymethylbenzo[a]pyrene (HMBP) in Salmonella typhimurium TA98 and TA100, indicating that corbic acid affects both frameshift and base-pair substitution mtltations. A similar type of dose-response relationship was shown in the V79 cells, although the inhibitory effect was less dramatic compared with that in S. typhimurium. However, SMBP or HMBP binding to calf thymus DNA was not affected by the presence of vitamin C, suggesting that SMBP seems to be much more reactive to calf thymus DNA than vitamin C. This was supported by migration pattern and fluorescence intensity of SMBP-modified plasmid on the gel. These restilts were not correlated with mutation tests in bacterial and mammalian cell systems. It has been already reported that vitamin C inactivates SMBP through the formation of covalently bound addact. It was found from HPLC analysis that the reaction between vitamin C and SMBP was accomplished within just 5 min and then produced the several products. These findings indicate that the beneficiary of vitamin C is not merely derived from the covalent adducts. On the other hand, the addition of DNA to incubation mixture reduced the amounts of vitamin C adducts while the magnitude of HMBP peak increased, suggesting that DNA accelerates the SMBP hydrolysis to intercept the interaction between SMBP and vitamin C or forms rapidly complex with SMBP.

• ALGAE
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• v.24 no.2
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• pp.121-127
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• 2009

The unicellular green alga, Haematococcus pluvialis, accumulates the highest level of astaxanthin among knownastaxanthi.n-producing organisms. Light is the most important factor to induce astaxanthin by H. pluvialis. BIue andred LEDs, whose ${\lambda}_{max}$'s are 470 and 665 nm, respectively, were used for internally illuminated light sources.Fluorescent lamps were also used for both internal and external illumination sources. The astaxanthin levels in thesevarious lighting systems were analyzed and compared each other. The cultures under internally illuminated LEDsaccumulaled 20% more astaxanthin than those under fluorescent lamp. Furthermore, LEDs generated much lessheat than the fluorescent lamps, which gives one more reason for the LEDs being a suitable internal Light source forastaxanthin induction. The results reported here would lead novel designs of photobioreactors with improvementsof illumination methods for high level of astaxanthm production. The maximum astaxanthin concentrations as wellas the astaxanthin yield per supplied photon were increased by at least 20% when blue or red LEDs were supplied.

• Animal cells and systems
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• v.7 no.1
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• pp.43-47
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• 2003

The skin of the eel goby, Odontamblyopus lacepedii, consists of epidermis, dermis and subcutis. The epidermis has three layers: the outermost layer, middle layer and stratum germinativum. The outermost layer is composed of polygonal cells or rather flattened cells, and mucous gland cells of acid mucopolysaccharides. The middle layer consists mainly of swollen small or voluminous epidermal cells and shows a web-shaped structure. The thickness of the epidermis depends on the various sizes and the number of layers of the swollen cells. Well-developed lymphatic spaces containing lymphocytes exist in the stratum germinativum and small scales are embedded in the dermis. A large number of blood capillaries are present just below the basement membrane, and a definite area giving AB and PAS positive was present between the basement membrane and scales, Taste buds ave distributed on surface of the epidermis at intervals. Considering the structural features of the skin, it may be considered that O. lacepedii is more likely to be related to cutaneous respiration as a dual respiratory system.

• Animal cells and systems
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• v.15 no.2
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• pp.115-121
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• 2011

Previous studies have demonstrated that N-methyl-D-aspartate (NMDA) receptors and acetylcholine receptors are related to learning and memory in rat and mice. In this study, we examined the effects of MK-801, a non-competitive NMDA receptor antagonist, on learning and memory in zebrafish using a passive avoidance test. We further tested whether or not nicotine, a nicotinic acetylcholine receptor agonist, and physostigmine, an acetylcholinesterase inhibitor, reverse the effects of MK-801. Crossing time was increased significantly in the training and test sessions for the controls. When 20 ${\mu}M$ MK-801 was administered prior to the training session, the crossing time did not increase in either session. The MK-801-induced learning deficit was rescued by pretreatment with 20 ${\mu}M$ physostigmine, and crossing time was increased in the training and test sessions compared to the MK-801-treated zebrafish. Further, the MK-801-induced learning deficit was prevented by pretreatment with 20 ${\mu}M$ nicotine, and crossing time was increased in the training session but not in the test session. These results show that MK-801 induced a learning deficit in zebrafish that was prevented by pretreatment with nicotine and physostigmine.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.1-14
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• 2022

Bacteria communicate with each other through an intricate communication mechanism known as quorum sensing (QS). QS regulates different behavioral aspects in bacteria, such as biofilm formation, sporulation, virulence gene expression, antibiotic production, and bioluminescence. Several different chemical signals and signal detection systems play vital roles in promoting highly efficient intra- and interspecies communication. Gram-negative bacteria coordinate gene regulation through the production of acyl homoserine lactones (AHLs). Gram-positive bacteria do not code for AHL production, while some gram-negative bacteria have an incomplete AHL-QS system. Despite this fact, these microbes can detect AHLs owing to the presence of LuxR solo receptors. Various studies have reported the role of AHLs in interspecies signaling. Moreover, as bacteria live in a polymicrobial community, the production of extracellular compounds to compete for resources is imperative. Thus, AHL-mediated signaling and inhibition are considered to affect virulence in bacteria. In the current review, we focus on the synthesis and regulation mechanisms of AHLs and highlight their role in interspecies bacterial signaling. Exploring interspecies bacterial signaling will further help us understand host-pathogen interactions, thereby contributing to the development of therapeutic strategies intended to target chronic polymicrobial infections.