• Journal of Preventive Medicine and Public Health
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• 제51권6호
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• pp.326-328
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• 2018

As over 1000 new cases of HIV/AIDS occur in Korea annually, preventive health programs against HIV/AIDS are urgently needed. Since phylodynamic studies have been suggested as a way to understand how infectious diseases are transmitted and evolve, phylodynamic inferences can be a useful tool for HIV/AIDS research. In particular, phylodynamic models are helpful for dating the origins of an epidemic and estimating its basic reproduction number. Thus, the introduction of phylodynamics would be a highly valuable step towards controlling the HIV/AIDS epidemic in Korea.

• Animal Systematics, Evolution and Diversity
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• 제24권3호
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• pp.327-332
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• 2008

Soft coral Dendronephthya gigantea (Verrill, 1864) is a conspicuous species dominating shallow sea waters of Jejudo Island, Korea. Recently its whole mitochondrial genome sequencing was completed by us and the sequence information provided an opportunity to test the age of Octocorallia and time of evolutionary separation between some representative orders of the subclass Octocorallia. Molecular phylogenetic analyses based on 13 mitochondrial protein encoding genes revealed a polyphyletic relationship among octocorallians representing two orders (Alcyonacea and Gorgonacea) and four families (Alcyoniidae, Nephtheidae, Briareidae, and Gorgoniidae). Estimates of divergence times among octocorallians indicate that the first splitting might occur around end of or after Cretaceous period (50-79 million years ago (Ma)). The age is relatively young compared to the long history of stony sea corals (>240 Ma). Taken together our result suggests a possible relatively recent radiating evolution at least in the order Alcyonacea and Gorgonacea. Molecular dating and phylogenetic analysis based on much broader taxon sampling and many genes might give an insight into this interesting hypothesis.

• 식물분류학회지
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• 제48권1호
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• pp.1-8
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• 2018

Mankyua chejuense is the only member of the monotypic genus Mankyua (Ophioglossaceae) and is endemic to Jejudo Island, Korea. To determine the precise phylogenetic position of M. chejuense, two cpDNA regions of 42 accessions representing major members of lycophytes are obtained from GenBank and analyzed using three phylogenetic analyses (maximum parsimony, maximum likelihood, and Bayesian inference). In addition, the divergence time is estimated based on a relaxed molecular clock using four fossil calibration points. The phylogenetic position of Mankyua still appears to be uncertain, representing either the earliest diverged lineage within Ophioglossaceae or a sister to the clade containing Ophioglossum and Helminthostachys. The most recent common ancestor of Ophioglossaceae and its sister lineage, Psilotum, was estimated to be 256 Ma, while the earliest divergence of Mankyua was estimated to be 195 Ma in the early Jurassic.

• Parasites, Hosts and Diseases
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• 제52권3호
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• pp.235-242
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• 2014

Paleoparasitology is the application of conventional or molecular investigative techniques to archeological samples in order to reveal parasitic infection patterns among past populations. Although pioneering studies already have reported key paleoparasitological findings around the world, the same sorts of studies had not, until very recently, been conducted in sufficient numbers in Korea. Mummified remains of individuals dating to the Korean Joseon Dynasty actually have proved very meaningful to concerned researchers, owing particularly to their superb preservation status, which makes them ideal subjects for paleoparasitological studies. Over the past several years, our study series on Korean mummies has yielded very pertinent data on parasitic infection patterns prevailing among certain Joseon Dynasty populations. In this short review, we summarized the findings and achievements of our recent paleoparasitological examinations of Joseon mummies and discussed about the prospects for future research in this vein.

• 대한방사성의약품학회지
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• 제6권1호
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• pp.20-26
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• 2020

Accelerator mass spectrometry (AMS) is a powerful detection technique with the exquisite sensitivity and high precision compared with other traditional analytical techniques. Accelerator mass spectrometry can be widely applied in the technique of radiocarbon dating in the fields of archeology, geology and oceanography. The ability of accelerator mass spectrometry to measure rare ¹⁴C concentrations in microgram and even sub-microgram amounts suggests that extension of ¹⁴C-accelerator mass spectrometry to biomedical field is a natural and attractive application of the technology. Drug development processes are costly, risky, and time consuming. However, the use of ¹⁴C-accelerator mass spectrometry allows absorption, distribution, metabolism and excretion (ADME) studies easier to understand pharmacokinetics of drug candidates. Over the last few decades, accelerator mass spectrometry and its applications to preclinical/clinical trials have significantly increased. For accelerator mass spectrometry analysis of biological samples, graphitization processes of samples are important. In this paper, we present a detailed sample preparation procedure to apply to graphitization of biological samples for accelerator mass spectrometry.

• Ocean and Polar Research
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• 제27권2호
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• pp.205-214
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• 2005

From ancient Antarctic glacier ice, we extracted total genomic DNA that was suitable for prokaryotic 16S rDNA gene cloning and sequencing, and bacterial artificial chromosome (BAC) library and end-sequencing. The ice samples were from the Dry Valley region. Age dating by $^{40}Ar/^{39}Ar$ analysis on the volcanic ashes deposited in situ indicated the ice samples are minimum 100,000-300,000 yr (sample DLE) and 8 million years (sample EME) old. Further assay proved the ice survived freeze-thaw cycles or other re-working processes. EME, which was from a small lobe of the basal Taylor glacier, is the oldest known ice on Earth. Microorganisms, preserved frozen in glacier ice and isolated from the rest of the world over a geological time scale, can provide valuable data or insight for the diversity, distribution, survival strategy, and evolutionary relationships to the extant relatives. From the 16S gene cloning study, we detected no PCR amplicons with Archaea-specific primers, however we found many phylotypes belonging to Bacteria divisions, such as Actinobacteria, Acidobacteria, Proteobacteria $({\alpha},\;{\beta},\;and\;{\gamma})$, Firmicutes, and Cytophaga-Flavobacterium-Bacteroid$. BAC cloning and sequencing revealed protein codings highly identical to phenylacetic acid degradation protein paaA, chromosome segregation ATPases, or cold shock protein B of present day bacteria. Throughput sequencing of the BAC clones is underway. Viable and culturable cells were recovered from the DLE sample, and characterized by their 16S rDNA sequences. Further investigation on the survivorship and functional genes from the past should help unveil the evolution of life on Earth, or elsewhere, if any.

• Clinical and Experimental Reproductive Medicine
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• 제27권2호
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• pp.117-131
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• 2000

Objectives: To develop a new immunohistochemical marker system for supplementation of the Noyes histological classification of the endometrium in women of child bearing age with regular menstrual cycles, and to employ this system to evaluate pathologic factors involved in endometriosis, and thus to ascertain if it is useful in diagnosis. Materials and Methods: Endometrial biopsies were sampled from the posterior fundus of 41 (24 proliferative phases, 17 secretory phases) women with regular menstrual cycles (28-32 days), and each sample was immunohistochemically stained according to Noyes et al (1975) for determination of expression for estrogen receptor (ER), progesterone receptor (PR), integrin ${\alpha}_1$, ${\alpha}_4$, ${\beta}_3$, COX-1 and COX-2. Then, the PR, integrin ${\beta}_3$ and COX-2 which were clearly expressed in the luteal phase was with endometrial samples were obtained from 20 cases of normal patients (group 1) and 25 cases with endometriosis (group 2) after confirming the day of ovulation by sex steroid level measurements 7-8 days after ovulation Results: In the regular menstruation group the expression of ER showed a tendency to be increased in the proliferative phase and decreased in the secretory phase, and was the highest in the proliferative phase. However, PR in the stromal cells showed no change in the entire menstrual cycle while in the epithelial cells, PR reached a peak in the late proliferative phase and was almost absent in the secretory phase. Integrin (${\alpha}_1$, ${\alpha}_4$, and ${\beta}_3$ expression in the epithelial cells was absent in the proliferative phase but ${\alpha}_1$ was strongly expressed starting from the early secretory phase into the entire secretory phase. ${\alpha}_4$ was expressed strongly in the early and mid secretory phases and disappeared in the late proliferative phase, while ${\beta}_3$ appeared after the mid secretory phase and continued to be expressed until the late secretory phase. Expression in the stromal cells was weak overall and did not show any cyclic pattern. COX-1 expression was shown as a cyclic pattern in the stromal and epithelial cells and was particularly strongly expressed in the mid secretory phase of epithelial cells, and in the mid secretory and menstruation phase of stromal cells. In the endometrial epithelial cells there was strong expression during the entire cycle with stronger expression in the secretory phase compared to the prolferative phase. COX-2 was clearly expressed in the late proliferative, early and mid secretory phases in the stromal cells. No expression was observed in the proliferative phase of the epithelial cells, but which began to appear in the early secretory phase reaching a significant pattern from the mid secretory phase onwards. There was almost no expression in the stromal cells. In the cases with endometriosis showing normal endometrial maturation according to the Noyes classification, PR expression was increased while Integrin-${\beta}_3$의 expression was significantly decreased compared to the normal group. Also, COX-2 expression was slightly decreased in the stromal cells of patients with endometriosis while it was significantly increased in the stromal cells. Conclusion: Immunohistochemical markers can supplement the original Noyes classification of histological endometrial dating and therefore ascertain existing pathologic conditions. Particularly for patients with endometriosis with normally mature endometrial cells, changes in COX-2 and integrin expression patterns may assist in elucidating pathophysiologic mechanisms and therefore aid in the diagnosis of abnormal implantation conditions, and consequently determine a treatment modality.