• Microbiology and Biotechnology Letters
• /
• v.18 no.5
• /
• pp.454-459
• /
• 1990

For the genetic multipurpose of antagonistic abilities of Pseudomom etutzeri YPL-1 aganist Fusarium solani causing root rot of many important crops by genetic engineering, optimal conditions for transformation of P-stutzeri YPL-1 by pKT230 were investigated. Maxium frequency of the transformation was achieved when cells were harvested at early exponential growth phase. The highest transformation efficiency was obtained when the competent cells were exposed to chilled transformation buffer containing 20 mM RbCI, 100 mM $CaCl_2$ and added l${\mu}g$/ml of plasmid DNA. The pH optimum for transformation was 6.5. When the bacterial cells that were incubated during 60 minutes for the competence were brought in contact with plasmid DNA, the transformations were obtained in the best frequency. It was formed that transformation frequency was 2 ~$6 \times 10^{-6}$ under the optimal conditions.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.27 no.1
• /
• pp.77-84
• /
• 2000

Although ferric sulfate has been proposed as an alternative to formocresol in pulpotomy treatment in primary teeth, it has been given little concern regarding its cytotoxicity and mutagenicity. In the present study, we assessed the in vitro genotoxic effect of a ferric sulfate on human gingival fibroblast cell line (HGF-1). DNA damage was evaluated using comet assay (single cell alkaline gel electrophoresis) and obtained the results as follows: 1. A dose-response relationship was found between ferric sulfate concentrations (0 to 5mM) and DNA damages. 2. Above the concentration of 0.1mM, DNA damage was significantly increased than those of the control (p<0.05). 2. At the fixed concentration of 0.05mM, no significant difference was found between exposure time and DNA damage. These findings suggest that ferric sulfate as a pulpotomy agent can induce DNA damage in human gingival fibroblasts.

• Journal of Microbiology
• /
• v.37 no.2
• /
• pp.59-65
• /
• 1999

RecA protein can promote strand assimilation, homologous pairing, and strand exchange. All these reactions require DNA-dependent ATP hydrolysis by recA protein, and the activities of recA protein are affected by the ionic environment. In this experiment, DNA-dependent ATPase activity showed different sensitivity to anionic species. ATP hydrolysis and strand exchange were relatively sensitive to salt in the reactions with NaCl, strongly inhibited at 100 mM NaCl. However, the inhibition by sodium acetate or sodium glutamate was not observed at 50∼100 mM concentration. Addition of sodium glutamate to the standard reaction condition increased the apparent efficiency of ATP hydrolysis during strand exchange. The condition including 50∼100 mM sodium-glutamate might be similar to the physiological condition.

• Toxicological Research
• /
• v.7 no.1
• /
• pp.13-20
• /
• 1991

To investigate the cytotoxicity and genotoxicity of the DNA alkylating agnet, mitomycin C and the antimetabolite, 5-Fluorouracil (5-FU) in cultured rat fibroblasts, the colorimetric assay of netural red (NR) for cytotoxicity and for genotoxicity, sister chromatid exchange (SCE) assay and the measurement of the rate of DNA synthesis were performed in cells cultured in media containing various concentrations of mitomycin C and 5-FU. The uptake ability of neutral red decreased does-dependently. NR90 and NR50 values of mitomycin C were 1.49 nM and 6.87mM and 5-FU were 38.4mM AND 284.4Mm respectively.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.48 no.1
• /
• pp.33-38
• /
• 2022

Ultraviolet B (UVB) damages DNA residues in skin keratinocytes. In particular, the formation of cyclobutane pyrimidine dimers (CPD), a pyrimidine residue damage in DNA, is considered a representative indicator of skin photoaging. In this study, we confirmed defensive effect of Glycyrrhiza glabra (G. glabra) extract against UVB induced DNA damage. First of all, we confirmed UVB dependent amount of CPD formation in human keratinocyte cell line. UVB induced CPD was decreased by G. glabra extract by dose dependent manner. In addition, it was confirmed that the expression of mRNA of DNA damage recovery factors was increased by G. glabra extract. Consequently, through this study, it was possible to confirm the DNA protection effect of G. glabra extract in skin keratinocytes.

• Korean Journal of Microbiology
• /
• v.13 no.3
• /
• pp.109-115
• /
• 1975

DNA's were extracted from Saccharomyces cerevisiae and Mycobacterium phlei and the damaging cell walls of these microoragnisms were examined under an electron microscope in the extraction process in which a number of physico-chemical tratments of cells was involved. While the DNA was easily extracted from S. cerevisiae using conventional meylelded very little DNA, of M. phlei was extremely difficult to isolate and yielded very little DNA, applying various methods of isolation published earlier. When the cell walls of S. cerevisiae were examined with the electron microscope, they were not yet damaged even after the cells were treated with sodium lauryl sulfate(SLS) and ethylene diamine tetracetic acid(EDTA), but they were completely destroyed by the treatment of sodium perchlorate followed by the addition of chloroform and a vigorous agitation. Oozing cytoplasm through the broken cell walls was also observed. In the extraction of DNA from M.phlei, the pronase was not effective at the aerobic environment of the sample. When phenol was applied at the last step of DNA isolation, an extreme damage mass yielding little DNA into the solution. Unlike the cells of S.cerevisiae.M.phlei cells showed a tendency of aggregation, thus the destruction of cell walls by sodium hydroxide was seen only on the walls of peripheral cells in the aggregated mass, leaving the walls of the inner cells undamaged.

• Molecular & Cellular Toxicology
• /
• v.1 no.2
• /
• pp.111-115
• /
• 2005

Ultraviolet (UV) radiation to mammalian skin is known to alter cellular function via generation of Reactive Oxygen Species (ROS), DNA damage and DNA lesions, such as pyrimidine dimmers and photoproducts, which could lead to DNA mutation if they are not repaired. In this study, we have investigated the reduction of DNA damage and of apoptosis with a particular attention to genetic effect of paeoniflorin in Normal Human Epidermal Keratinocytes (NHEK). After UVB irradiation from $10\;to\;500mJ/cm^{2}$ to NHEK, Mean Tail Moments (MTM) were increased with UVB dose increase. The greatest amount of strand breaks was induced at $500mJ/cm^{2}$ of UVB. Even at the lowest dose of UVB ($10mJ/cm^{2}$), change in MTM was detected (P<0.0001). Pretreated cell with 0.1% paeoniflorin maximally reduced the level of DNA damage to about 21.3%, compared to untreated cell. In the lower concentrations less than 0.01% of paeoniflorin, MTM had a small increase but paeoniflorin still had reductive effects of DNA damage. We measured the apoptosis suppression of paeoniflorin with annexin V flous staining kit. As we observed under the fluorescence microscopy to detect apoptosis in the irradiated cell, the fluorescence intensity was clearly increased in the untreated cell, but decreased in treated cells with paeoniflorin. These results suggest that paeoniflorin reduces the alteration of cell membranes and prevents DNA damage. Therefore, the use of paeoniflorin as a free radical scavenger to reduce the harmful effects of UV lights such as chronic skin damage, wrinkling and skin cancer can be useful to prevent the formation of photooxidants that result in radical damage.

• Clinical and Experimental Reproductive Medicine
• /
• v.45 no.1
• /
• pp.17-24
• /
• 2018

Objective: To investigate sperm chromatin/DNA integrity, global DNA methylation, and DNMT mRNA transcription in men with oligoasthenoteratozoospermia (OAT) compared with normozoospermic men. Methods: Semen samples from 32 OAT patients who comprised the case group and 32 normozoospermic men who comprised the control group were isolated and purified using a standard gradient isolation procedure according to World Health Organization criteria. DNMT1, DNMT3A, and DNMT3B transcripts were then compared between groups using real-time quantitative reverse-transcription polymerase chain reaction. Global DNA methylation in sperm was determined by an enzyme-linked immunosorbent assay. Protamine deficiency and the proportion of apoptotic spermatozoa were evaluated using chromomycin A3 (CMA3), aniline blue (AB), and toluidine blue (TB) staining, as well as the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The p-values < 0.05 were considered to indicate statistical significance. Results: Significantly higher proportions of AB+, TB+, CMA3+, and TUNEL+ spermatozoa, as well as DNMT3A and DNMT3B transcription, were found in the OAT group. Positive correlations were detected between sperm parameters, DNA/chromatin damage, and DNMT3A and DNMT3B transcripts. Global DNA methylation was significantly higher in the OAT patients and had a significant correlation with abnormal results of all sperm chromatin integrity tests, but was not associated with DNMT1, DNMT3A, or DNMT3B expression. Conclusion: Oligoasthenoteratozoospermic men showed abnormal sperm parameters, abnormal chromatin/DNA integrity, and a higher global DNA methylation rate, as well as overexpression of DNMT mRNA.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.45 no.2
• /
• pp.209-216
• /
• 2019

Ultraviolet rays (UV) cause photoaging by inducing skin photodamages such as erythema and sunburn. Silymarin is a mixture of antioxidant polyphenols extracted from Silybum marianum fruit (S. m), which is known as milk thistle. It is known to protect skin tissues from UV treatment and antioxidant effects. In this study, we aimed to identify the photoprotective effects of S. m extract, which has silymarin in the epidermis layer of the skin. We found that the extract can function as a UV filter, so it can reduce DNA damage by UV treatment. Especially, we found that, in the stratum corneum, the extract can suppress the protein carbonylarion and DNA damages caused by suberythemal dose of UV treatment which does not induce erythema in the skin. UV treatment also increased protein carbonylation levels in the stratum corneum by oxidation, but it was prevented by applying the extract. The extract can absorb UV with minimal phototoxicity. Together, our study suggests that S. m extract can be used as a photo-protective ingredient to avoid photoaging of the skin.

• The Plant Pathology Journal
• /
• v.25 no.3
• /
• pp.247-255
• /
• 2009

Root-knot nematode species, such as Meloidogyne hapla, M. incognita, M. arenaria, and M. javanica are the most economically notorious nematode pests, causing serious damage to a variety of crops throughout the world. In this study, DNA sequence analyses were performed on the D3 expansion segment of the 28S gene in the ribosomal DNA in an effort to characterize genetic variations in the three Meloidogyne species obtained from Korea and four species from the United States. Further, PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism), SCAR (Sequence Characterized Amplified Region) PCR and RAPD (Randomly Amplified Polymorphic DNA) were also utilized to develop methods for the accurate and rapid species identification of the root-knot nematode species. In the sequence analysis of the D3 expansion segment, only a few nucleotide sequence variations were detected among M. incognita, M. arenaria, and M, javanica, but not M. hapla. As a result of our haplotype analysis, haplotype 5 was shown to be common in M. arenaria, M. incognita, M. javanica, but not in the facultatively parthenogenetic species, M. hapla. PCR-RFLP analysis involving the amplification of the mitochondrial COII and large ribosomal RNA (lrRNA) regions yielded one distinct amplicon for M. hapla at 500 bp, thereby enabling us to distinguish M. hapla from M. incognita, M. arenaria, and M. javanica reproduced via obligate mitotic parthenogenesis. SCAR markers were used to successfully identify the four tested root-knot nematode species. Furthermore, newly attempted RAPD primers for some available root-knot nematodes also provided some species-specific amplification patterns that could also be used to distinguish among root-knot nematode species for quarantine purposes.