• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1735-1740
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• 2008

Clone PERV-C (A3) env was isolated from the genomic DNA of domestic pig (Sus scrofa domesticus) in Korea to investigate the molecular properties of PERV-C. The nucleic acid homologies between the PERV-MSL (type C) reference and the PERV-C(A3) clone was 99% for env, but a single base pair deletion was found in the transmembrane (TM) region of the env open reading frame. To examine the functional characteristics of truncated PERV-C env, we constructed a replication-incompetent retroviral vector by replacing the env gene of the pCL-Eco retrovirus vector with PERV-C env. A retroviral vector bearing PERV-C/A chimeric envelopes was also created to complement the TM defect. Our results indicated that truncated PERV-C env was not infectious in human cells as expected. Interestingly, however, the vector with the PERV-C/A envelope was able to infect 293 cells. This observation suggests that recombination within PERV-C TM could render PERV-C infectious in humans. To further characterize PERV-C/A envelopes, we constructed an infectious molecular clone by using a PCR-based technique. This infectious molecular clone will be useful to examine more specific regions that are critical for human cell tropism.

• Herbal Formula Science
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• v.15 no.1
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• pp.213-228
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• 2007

Objectives : The purpose of this report was to investigate the chemotherapeutic effect of Bujeonghangamtang against cancer cells. Materials and Methods : Various cancer cell lines including PANC-1, C6 glioma, SH-SY5Y, HepG2, and MCF-7 cells, were used. Apoptosis was determined by DAPI nuclei staining and flow cytometry in PANC-1 cells treated with 1 mg/ml Bujeonghangamtang for 48 hr. Expression of cell cycle arrest mediators including, cdc2p34 and cyclin B1 proteins were measured by Western blot analysis. Mitochondrial membrane potential was measured by fluorescence staining with JC-1, rhodamine 123. Result : Bujeonghangamtang induced the apoptosis of PANC-1, which was characterized as nucleic acid and genomic DNA fragmentation, chromatin condensation, and sub-G0/G1 fraction of cell cycle increase. but not C6 glioma, SH-SY5Y, HepG2, and MCF-7 cells. PANC-1 cells were markedly sensitive to Bujeonghangamtang. Treatment with Bujeonghangamtang resulted in the decreased expression of cdc2p34 and cyclin B1. Treatment with Bujeonghangamtang also increased the ROS production and induced mitochondrial dysfunction. Conclusion : Bujeonghangamtang exerted cytotoxicity against human Pancreatic cancer cells via cell cycle arrest-mediated apoptotic signaling including ROS production and mitochondrial dysfunction. Our data suggest that Bujeonghangamtang may be an important modulator of chemosensitivity of cancer cells against anticancer chemotherapeutic agents.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.738-742
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• 2012

Here, we develop a new nanofilter device for the rapid and efficient separation of nanoparticles and biomolecules, exploiting the use of AAO mebrane with ordered nanopores in the range from 20 nm to 200 nm. Briefly, the chip comprises of a series of the upper and lower PDMS channels containing embedded inlet and outlet ports, and $50{\mu}m$ width microfluidic channel, and AAO membrane to be made the filtering zone. After assembling these components, the acrylate plastic plates were used to fix the device on the top and bottom side. When introducing the samples into the inlet ports of the upper PDMS channel, we were able to separate and concentrate the nanoparticles and target molecules at the filtering zone, and to elute the solutions containing the unwanted materials toward the lower PDMS channels normal to the direction of AAO membrane. To demonstrate the usefulness of the device we apply it to the SERS detection of nucleic acid sequences associated with Dengue virus serotype 2. We report a limit of detection for Dengue sequences of 300 nM and show excellent enhancement of Raman signals from the filter zone of the nanofilter device.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.1
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• pp.129-138
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• 1999

If rumen bacteria can be manipulated to utilize nutrients (i.e., ammonia and plant cell wall carbohydrates) more completely and efficiently, the need for protein supplementation can be reduced or eliminated and the digestion of fiber in forage or agricultural residue-based diets could be enhanced. However, these approaches require a complete and accurate description of the rumen community, as well as methods for the rapid and accurate detection of microbial density, diversity, phylogeny, and gene expression. Molecular ecology techniques based on small subunit (SSU) rRNA sequences, nucleic acid probes and the polymerase chain reaction (PCR) can potentially provide a complete description of the microbial ecology of the rumen of ruminant animals. The development of these molecular tools will result in greater insights into community structure and activity of gut microbial ecosystems in relation to functional interactions between different bacteria, spatial and temporal relationships between different microorganisms and between microorganisms and reed panicles. Molecular approaches based on SSU rRNA serve to evaluate the presence of specific sequences in the community and provide a link between knowledge obtained from pure cultures and the microbial populations they represent in the rumen. The successful development and application of these methods promises to provide opportunities to link distribution and identity of gastrointestinal microbes in their natural environment with their genetic potential and in situ activities. The use of approaches for assessing pupulation dynamics as well as for assessing community functionality will result in an increased understanding and a complete description of the gastrointestinal communities of production animals fed under different dietary regimes, and lead to new strategies for improving animal growth.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.85-91
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• 2016

Exosomes are homogenous vesicles of 40-100 nm diameter produced endogenously. Exosomes are generated by inward budding into multi-vesicular bodies (MVB) and then released to extracellular space. Exosomes contain various nucleic acid and protein cargoes from their cells of origin and this endosomal cellular molecules are used for intracellular communication and for both promotion and suppression of immune responses. Recently, they are also considered as delivery vehicle for therapeutic proteins due to their characteristics of stability in body fluids and ability for target uptake. Also, they show less immune reactivity because the isolated exosome harboring therapeutic proteins can be from the same host. White-spotted flower chafer, Protaetia brevitarsis is one of the major insect commercially reared in Korea. There are bacterial and fungal pathogens causing diseases in the beetle, and these diseases incur economic loss to the larva-rearing farms. Due to their endosomal cargoes, exosomes are good candidates in use of disease diagnosis. In this study, we isolated insect exosome from the hemolymph of P. brevitarsis, and verified it by analysis of the exosome-specific surface proteins and RNA.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.838-843
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• 2017

Sepsis is a major health problem worldwide, with an extremely high rate of morbidity and mortality, partly due to delayed diagnosis during early disease. Currently, sepsis diagnosis requires bacterial culturing of blood samples over several days, whereas PCR-based molecular diagnosis methods are faster but lack sensitivity. The use of biosensors containing nucleic acid aptamers that bind targets with high affinity and specificity could accelerate sepsis diagnosis. Previously, we used the systematic evolution of ligands by exponential enrichment technique to develop the aptamers Antibac1 and Antibac2, targeting the ubiquitous bacterial peptidoglycan. Here, we show that these aptamers bind to four gram-positive and seven gram-negative bacterial sepsis agents with high binding efficiency. Thus, these aptamers could be used in combination as biological recognition elements in the development of biosensors that are an alternative to rapid bacteria detection, since they could provide culture and amplification-free tests for rapid clinical sepsis diagnosis.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.304-310
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• 2016

This study shows the changes of the nucleotides and their related compounds of squid during fermentation for 8 weeks at $10^{\circ}C$ in 5% salt solution. Among nucleic acid related matters, ATP and ADP were vanished not to be detected, AMP existed only at the early stage and then rapidly decreased until the mid-stage of the ripening. Inosine and hypoxanthine were the main components of nucleotides and their related compounds. As the salt concentration was decreased and fermentation temperature raised, pH was significantly increased to the latter stage of the ripening and hence fermentations was enhanced. The titrable acidity was continuously decreased until the latter stage of the ripening. Considering the above result, it is possible to make an estimate that the suitable fermentation conditions of squids are $10^{\circ}C$ of fermentation temperature, 10% of salt concentration and 5 weeks of ripening period.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.41-47
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• 2009

The seasonal reproductive cycle of Gomphina melanaegis collected in the coastal area of Jumunjin, between April 2006 and March 2007, was analyzed. Maturation cycle parameters such as the gonad index (GI), ovarian egg diameter, frequency of developmental stages, protein content, and RNA/DNA variation in the gonads were analyzed monthly for the 40 samples. According to the indices from histological sections, the frequency of gonad developmental stages, and the oocyte diameter, this clam has a long-term partial spawning pattern from March to October. However, GI and nucleic acid values showed that the mature stage is from March to July and that the main spawning season is August. The peak RNA and DNA contents were good indicators of sexual maturation in females and males, respectively. The variation in protein content corresponded with the RNA/DNA ratios.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.918-922
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• 2001

In a previous study, we have isolated a number of lactobacilli from Korean women, and one of them (KLB46) was identified as Lactobacillus crispatus by 16S rRNA gene sequencing. For the ecological treatment of bacterial vaginosis (BV) cell suspension of L. crispatus KLB46 was instillated into BV patients. L. crispatus KLB46 was found to persist for several days in cell suspension with no nutrients. In this study, in order to assess the influence of starvation on physiological activity, we compared the viability and culturability of KLB46 following suspension in various buffer solutions. A pair of in situ fluorescent dye was used to assess viability (i.e. membrane integrity) and the culturability was examined by plate count assay. A rapid epifluorescence staining method using the LIVE/DEAD Bacterial Viability Kit $(BacLight^{TM})$ was applied to estimate both viable and total counts of bacteria in cell suspension. $BacLight^{TM}$ is composed of two nucleic acid-binding stains ($SYTO\;9^{TM}$ and propidium iodide). $SYTO\;9^{TM}$ penetrates all bacterial membranes and stains the cells green while propidium iodide only penetrates cells with damaged membranes, therefore the combination of the two stains produces red fluorescing cells. Optimal staining conditions for $BacLight^{TM}$ were found to be with 0.0835M $SYTO\;9^{TM}$ and 0.05M propidium iodide for 15 min incubation at room temperature in dark. When cells were microscopically examined during 140 hours of starvation, the culturability decreased markedly while the viability remained relatively constant, which suggests that large fraction of KLB46 cells became viable but non-culturable (VBNC) upon starvation.

• Applied Biological Chemistry
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• v.50 no.4
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• pp.304-307
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• 2007

An efficient production method of spirulina extract was developed by enzymatic treatment using cell lytic and proteolytic enzymes. The suitable dosage of Tunicase, a cell lytic enzyme, was found to be 2.0% (w/w). Proteolytic enzymes were screened to obtain high solid recovery and spirulina extraction (SE) index, which indicates nucleic acid-related substances content. Among the seven tested proteases, Esperase was selected and optimal dosage of this enzyme was 2.0% (w/w). The solid recovery and SE index of simultaneous treatment and co-treatment using optimal dosages of Tunicase and Esperase were greatly similar, respectively. However, co-treatment had the effect of shortening total hydrolysis time. The SE index and solid recovery of co-treatment were significantly enhanced by 75% $(11.4{\rightarrow}20.0)$ and 45% $(45.2%{\rightarrow}65.3%)$, respectively, than those of the non-treated extracts.