• The Korean Journal of Mycology
• /
• v.37 no.2
• /
• pp.198-200
• /
• 2009

From 2008 to 2009, the stem rot of Astragalus sinicus L. caused by Sclerotium rolfsii occurred sporadically in Gyeongnam area, Korea. The typical symptom is water-soaking, rotting and wilting on the stem. The infected plants were eventually died. White mycelial mats were spread over lesions, and then sclerotia were formed on stems and near soil line. The sclerotia were globoid in shape, white to brown in color, 1-3 mm in size and the hyphal width was 3-9 μm. The optimum temperature for mycelial growth and sclerotial formation on PDA was 30oC. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. On the basis of mycological characteristics and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report on the stem rot of A. sinicus caused by S. rolfsii in Korea.

• The Korean Journal of Mycology
• /
• v.38 no.2
• /
• pp.205-207
• /
• 2010

Stem and petiole rot symptoms of Valeriana fauriei occurred sporadically in the herb exhibition field in Gyeongsangnam-do Agricultural Research and Extension Services, Hamyang-gun, Gyeongnam Province in Korea. The typical symptom is water-soaking on the stem, rotting, wilting, blighting and the infected plants eventually died. White mycelial mats spreaded over lesions, and then sclerotia were formed on the infected plant parts and near soil surface line. On the basis of mycological characteristics and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii. This is the first report of stem rot on Valeriana fauriei caused by Sclerotium rolfsii in Korea.

• Biomolecules & Therapeutics
• /
• v.27 no.1
• /
• pp.78-84
• /
• 2019

Cell therapeutic agents for treating degenerative brain diseases using neural stem cells are actively being developed. However, few systems have been developed to monitor in real time whether the transplanted neural stem cells are actually differentiated into neurons. Therefore, it is necessary to develop a technology capable of specifically monitoring neuronal differentiation in vivo. In this study, we established a system that expresses cell membrane-targeting red fluorescent protein under control of the Synapsin promoter in order to specifically monitor differentiation from neural stem cells into neurons. In order to overcome the weak expression level of the tissue-specific promoter system, the partial 5' UTR sequence of Creb was added for efficient expression of the cell surface-specific antigen. This system was able to track functional neuronal differentiation of neural stem cells transplanted in vivo, which will help improve stem cell therapies.

• BMB Reports
• /
• v.49 no.1
• /
• pp.3-10
• /
• 2016

microRNAs (miRNAs) are key regulators of cell state transition and retention during stem cell proliferation and differentiation by post-transcriptionally downregulating hundreds of conserved target genes via seed-pairing in their 3' untranslated region. In embryonic and adult stem cells, dozens of miRNAs that elaborately control stem cell processes by modulating the transcriptomic context therein have been identified. Some miRNAs accelerate the change of cell state into progenitor cell lineages—such as myoblast, myeloid or lymphoid progenitors, and neuro precursor stem cells—and other miRNAs decelerate the change but induce proliferative activity, resulting in cell state retention. This cell state choice can be controlled by endogenously or exogenously changing miRNA levels or by including or excluding target sites. This control of miRNA-mediated gene regulation could improve our understanding of stem cell biology and facilitate their development as therapeutic tools. [BMB Reports 2016; 49(1): 3-10]

• Bulletin of the Korean Chemical Society
• /
• v.33 no.6
• /
• pp.1983-1988
• /
• 2012

Stem cell transplantation is emerging as a possible new treatment for liver cirrhosis, and recent animal studies have documented the benefits of stem cell therapy in a hepatic fibrosis model. However, the underlying mechanism of stem cell therapy is still unclear. Among the proposed mechanisms, the cell replacement mechanism is the oldest and most important, in which permanently damaged tissue can be replaced by normal tissue to restore function. In the present study, Cy5.5-labeled superparamagnetic iron oxide (SPIO) was used to label human mesenchymal stem cells. The uptake of fluorescently labeled nanoparticles enabled the detection and monitoring of the transplanted stem cells; therefore, we confirmed the direct incorporation and differentiation of SPIO into the hepatocyte-like transplanted stem cells by detecting human tyrosine aminotransferase (TAT), well-known enzymatic marker for hepatocyte-specific differentiation.

• Journal of Ecology and Environment
• /
• v.37 no.4
• /
• pp.177-184
• /
• 2014

This study was conducted to develop allometric equations and to determine the stem density and biomass expansion factor (BEF) for the estimation of the aboveground and belowground biomass of Cryptomeria japonica in Jeju Island, Korea. A total of 18 trees were harvested from the 40-year-old C. japonica stands in Hannam experimental forest, Jeju Island. The mean biomass of the C. japonica was $50.4Mg\;ha^{-1}$ in stem wood, $23.1Mg\;ha^{-1}$ in root, $9.6Mg\;ha^{-1}$ in branch, $4.6Mg\;ha^{-1}$ in needle and $4.3Mg\;ha^{-1}$ in stem bark. The diameter at breast height (DBH) was selected as independent variable for the development of allometric equations. To evaluate the performance of these equations, coefficient of determination ($R^2$) and root mean square error (RMSE) were used and results of the evaluation showed that $R^2$ ranged from 71% (root biomass equation) to 96% (aboveground biomass equation) and the RMSE ranged from 0.10 (aboveground biomass equation) to 0.33 (root biomass equation). The mean stem density of C. japonica was $0.37g\;cm^{-3}$ and the mean aboveground BEF was $1.28g\;g^{-1}$. Furthermore, the ratio of the root biomass to aboveground biomass was 0.32.

• BLOOD RESEARCH
• /
• v.53 no.4
• /
• pp.320-324
• /
• 2018

Background Recent studies have devoted much attention to non-protein-coding transcripts in relation to a wide range of malignancies. MALAT1, a long non-coding RNA, has been reported to be associated with cancer progression and prognosis. Thus, we here determined MALAT1 gene expression in chronic lymphocytic leukemia (CLL), a genetically heterogeneous disease, and explored its possible relationships with cytogenetic abnormalities. Methods MALAT1 expression level was evaluated using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) on blood mononuclear cells from 30 non-treated CLL patients and 30 matched healthy controls. Cytogenetic abnormalities were determined in patients by fluorescence in situ hybridization (FISH). Results MALAT1 expression level was up-regulated in the CLL group compared to healthy controls (P=0.008). Del13q14, followed by Del11q22, were the most prevalent cytogenetic abnormalities. We found no association between the FISH results and MALAT1 expression in patients. Conclusion Altered expression of MALAT1 is associated with CLL development. Further investigations are required to assess the relationship between this long non-coding RNA and CLL patient survival and prognosis.

• Reproductive and Developmental Biology
• /
• v.28 no.1
• /
• pp.65-70
• /
• 2004

In mammals, male and female germline stem cells are derived from primodial germ cells. Despite many efforts to identify stem cells from gonads, there has been little successe to identify germline stem cells yet. In this study, we isolate and characterized porcine germline stem cells using only stem cell markers that are prevalently expressed in various tissues. Gonadal cells derived from both male and female formed colonies and showed AP activities and different lectin binding properties. Pluripotency of germline stem cells was also identified by positive signals against putative stem cells markers such as SSEA-1 and SSEA-3. In addition, nestin was also found in primary gonad cells that have a similar morphology to the AP-positive cells. The nestin expression suggests that the germline stem cells may have similar expression of the prevalent stem cell markers found in other tissues. The demonstration of nestin expression together with pluripotent cell markers calls further investigation of the possible differentiation of nestin-positive cells into neurons.

• Molecules and Cells
• /
• v.37 no.10
• /
• pp.742-746
• /
• 2014

The epithelial cell adhesion molecule (EpCAM, also known as CD326) is a transmembrane glycoprotein that is specifically detected in most adenocarcinomas and cancer stem cells. In this study, we performed a Cell systematic evolution of ligands by exponential enrichment (SELEX) experiment to isolate the aptamers against EpCAM. After seven round of Cell SELEX, we identified several aptamer candidates. Among the selected aptamers, EP166 specifically binds to cells expressing EpCAM with an equilibrium dissociation constant (Kd) in a micromolar range. On the other hand, it did not bind to negative control cells. Moreover, EP166 binds to J1ES cells, a mouse embryonic stem cell line. Therefore, the isolated aptamers against EpCAM could be used as a stem cell marker or in other applications in both stem cell and cancer studies.

• Research in Plant Disease
• /
• v.22 no.2
• /
• pp.116-121
• /
• 2016

In 2015, stem blight of Rubus crataegifolius was observed in Pohang, Korea. The symptoms began as dark red spots in the stem, which led to stem blight, then leaf blight, and eventually resulted in death. A fungal isolate was obtained from a symptomatic stem and incubated on a potato dextrose agar plate. The isolated fungus produced white, cloudy mycelia turned black in 3 days. Based on the morphological characteristics, the causal fungus was assumed to be Botryosphaeria sp. A pathogenicity test was conducted according to Koch's postulates. To identify the causal agent, the combined sequence of the internal transcribed spacer, ${\beta}$-tubulin, and translation elongation factor $1{\alpha}$ genes were used for phylogenetic analysis. Approximately 1,200 bp of the combined sequence clearly suggested that the isolated pathogen was Botryosphaeria parva. This is the first report on stem blight in R. crataegifolius caused by B. parva in Korea.