• Journal of Microbiology
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• v.43 no.2
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• pp.172-178
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• 2005

To determine the prevalence and genotypes of $\beta$-lactamases among clones of a metagenomic library from the cold-seep sediments of Edison seamount (10,000 years old), we performed pulse-field gel electrophoresis, antibiotic susceptibility testing, pI determination, and DNA sequencing analysis. Among the 8,823 clones of the library, thirty clones produced $\beta$-lactamases and had high levels of genetic diversity. Consistent with minimum inhibitory concentration patterns, we found that five ($167\%$) of thirty clones produced an extended-spectrum $\beta$-lactamase. 837- and 259-bp fragments specific to bla$_{TEM}$ genes were amplified, as determined by banding patterns of PCR amplification with designed primers. TEM­1 was the most prevalent $\beta$-lactamase and conferred resistance to ampicillin, piperacillin, and cephalothin. TEM-116 had a spectrum that was extended to ceftazidime, cefotaxime, and aztreonam. The resistance levels conferred by the pre-antibiotic era alleles of TEM-type $\beta$-lactamases were essentially the same as the resistance levels conferred by the TEM-type alleles which had been isolated from clinically resistant strains of bacteria of the antibiotic era. Our first report on TEM-type $\beta$-lactamases of the pre-antibiotic era indicates that TEM-type $\beta$-lactamases paint a picture in which most of the diversity of the enzymes may not be the result of recent evolution, but that of ancient evolution.

• Journal of Photoscience
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• v.2 no.1
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• pp.37-45
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• 1995

INTRODUCTION : Psoralens are planar tricyclic furocoumarins present in numerous plants and fungi found throughout the world.' Naturally occurring and synthesized psoralen derivatives(see Figure 1) are photosensitizers of UVA especially from 320 nm to 400 nm, a range at which cellular nucleic acids and proteins are weakly absorbing if any at all. Because of their skinphotosensitizing properties, these compounds have been used in the photochemotherapy of psoriasis and vitiligo. However, undesirable side effects such as carcinoma development in hairless mice as well as possible liver damage from the use of 8-methoxypsoralen(8-MOP) have been reported. The other photobiological effects include inactivation of DNA viruses, killing and mutagenesis of bacteria, inhibition of tumor transmitting capacity of various cells, and hyperpigmentation on human and guinea pig skin. PUVA(psoralen+UVA) photochemotherapy is in fact thousands of years old, having been used in Egypt and India since B.C. 1200-2000. Photochemotherapy for a common disfiguring disease, vitiligo, was practiced in the ancient world by physicians and herbalists who used boiled extracts of the fruits of certain umbelliferous plants, e.g. Ammi majus Linnaeus in Egypt or the leguminous plants, Psoralea corylifolia L. in India. It was first described by Kuske in 19388 that photosensitization of skin by plants was related to the presence of psoralen. He identified natural psoralens in plants as photosensitizers and isolated bergapten(5methoxypsoralen) from the oil of bergamot. The scientific interest in photosensitizing psoralens, however, has grown considerably after the introduction into clinics of the psoralen photochemotherapy for the treatment of psoriasis and of other skin (abbreviation)

• Journal of Life Science
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• v.13 no.6
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• pp.958-969
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• 2003

The human Y chromosome is strictly paternally inherited and does not X-Y crossing over during male meiosis in most of its length. Although this region came to be known as the non-recombining region Y (NRY), it was renamed as male-specific region Y (MSY) due to abundant recombination. The MSY is a mosaic of heterochromatic sequences and three classes of euchromatic sequences: X-transposed, X-degenerated and ampliconic. The X-transposed sequences exhibit 99% identity to the X chromosomal sequences. The X-degenerate sequences are remnants of ancient autosomes from which the modem X and Y chromosomes evolved. Eight palindromes of the ampliconic comprise one-quarter of the euchromatic DNA of the male-specific region of the human Y chromosome. They contain many testis-specific genes and typically exhibit 99.97% intra-palindromic (arm-to-arm) sequence identity. The arms of these palindromes must have subsequently engaged in gene conversion, driving the pair arms to evolve it concert. Averages of approximately 600 nucleotides per newborn male have undergone Y-Y gene conversion, which has had an important role in the evolution of multi-copy testis gene families in the MSY.

• The Korea Journal of Herbology
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• v.36 no.1
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• pp.9-17
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• 2021

Objectives : Tetrapanacis Medulla and Akebiae Caulis are one of the most frequently adulterated herbal medicines because of their confusability of terms in the ancient writings and the similarity of morphological features of dried herbal products. The major adulterant is Aristolochia manshuriensis (Guanmutong) which has a serious safety concern with its toxicity. To ensure the safety and quality of the two herbal medicines, it is necessary to discriminate the toxic adulterant from authentic species. The aim of this study is to develop SCAR markers and to establish the multiplex-SCAR assay for discrimination of four plant species related to Tetrapanacis Medulla and Akebiae Caulis. Methods : ITS regions of fifteen samples of four species (Tetrapanax papyrifer, Fatsia japonica, Aristolochia manshuriensis, and Akebia quinata) collected from different sites were amplified and sequenced. Fifteen obtained ITS sequences were aligned and analysed for the detection of species-specific sequence variations. The SCAR markers were designed based on the sequence alignments and then, multiplex-SCAR assay enhancing rapidity was optimized. Results : ITS sequences clearly distinguished the four species at the species level. The developed SCAR markers and multiplex-SCAR assay were successfully discriminated four species and detected the adulteration of commercial product samples by comparison of the amplified DNA fragment sizes. Conclusions : These SCAR markers and multiplex-SCAR assay are a rapid, simple, and reliable method to identify the authentic Tetrapanacis Medulla and Akebiae Caulis from adulterants. These genetic tools will be useful to ensure the safety and to standardize the quality of the two herbal medicines.

• Korean Journal of Plant Taxonomy
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• v.48 no.4
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• pp.249-259
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• 2018

$Iso{\ddot{e}}tes$ L. ($Iso{\ddot{e}}taceae$) is a cosmopolitan genus of heterosporous lycopods containing ca. 200 species being found in lakes, streams, and wetlands of terrestrial habitats. Despite its ancient origin, worldwide distribution, and adaptation to diverse environment, species in $Iso{\ddot{e}}tes$ show remarkable morphological simplicity and convergence. Allopolyploidy appears to be a significant speciation process in the genus. These characteristics have made it difficult to assess the phylogenetic relationships and biogeographic history of $Iso{\ddot{e}}tes$ species. In recent years, these difficulties have somewhat been reduced by employing multiple molecular markers. Here, we reconstruct the phylogenetic relationships in East Asian $Iso{\ddot{e}}tes$ species. We also provide their divergence time and biogeographic origin using a fossil calibrated chronogram. East Asian $Iso{\ddot{e}}tes$ species are divided into two clades: I. asiatica and the remaining species. $Iso{\ddot{e}}tes$ asiatica from Hokkaido forms a clade with northeastern Russian and western North American $Iso{\ddot{e}}tes$ species. In clade I, western North America is the source area for the dispersal of $Iso{\ddot{e}}tes$ to Hokkaido and northeastern Russia via the Bering land bridge during the late Miocene. The remaining $Iso{\ddot{e}}tes$ species (I. sinensis, I. yunguiensis, I. hypsophila, I. orientalis, I. japonica, I. coreana, I. taiwanensis, I. jejuensis, I. hallasanensis) from East Asia form a sister group to Papua New Guinean and Australian species. The biogeographic reconstruction suggests an Australian origin for the East Asian species that arose through long-distance dispersal during the late Oligocene.