• Journal of Life Science
• /
• v.29 no.12
• /
• pp.1329-1336
• /
• 2019

Subventricular zone (SVZ) in the brain contains neural stem cells (NSCs) which self-renew and differentiate to neurons and glial cells during postnatal period and throughout adulthood. Since fate decision to either proliferation or differentiation has to respond to intracellular and extracellular conditions, many intrinsic and extrinsic factors are involved. Among them, mitochondria have been reported to participate in fate decision of NSCs. In our previous report, we showed that long-term treatment of a mitochondrial inhibitor rotenone greatly inhibited neurogenesis. In this study, we examined the effects of short-term treatment of rotenone on SVZ NSCs. We found that (1) even one-day treatment of rotenone significantly reduced neurogenesis and earlier time points seemed to be more sensitive to rotenone, (2) a number of Mash1+ transit amplifying cells was decreased by one-day treatment of rotenone, (3) short-term treatment of rotenone eliminated most of the differentiated Tuj1+ neurons and Olig2+ oligodendrocytes, while glial fibrillary acidic protein (GFAP)+ astrocytes were not affected, and (4) sulfiredoxin 1 (Srxn1) gene expression was increased after one-day treatment of rotenone, indicating activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. All these results confirm that functional mitochondria are necessary during differentiation to neurons or oligodendrocytes as well as maintenance of neurons after differentiation. Also, these data suggest that temporary exposure to mitochondrial inhibitor such as rotenone might have long-term effects on neurogenic potential of NSCs.

• The Korean Journal of Mycology
• /
• v.12 no.4
• /
• pp.141-152
• /
• 1984

Aspergillus niger van Tieghem was cultured by the method of synchronous and submerged culture. Throughout the culture, sporulation was occured. Highly phosphorylated nucleotides in sporulating mycelia were detected to assure whether the eucaryotic Aspergillus niger produce these substances or not during the differentiation. Phosphorylated nucleotides were extracted from the conidiophore, bearing mycelia and spore forming body, these nucleotides were identified by TLC with P.E.I. cellulose. Guanosine tetraphosphate was found in both phialide forming mycelia and spore forming body. The contents of free amino acids were assayed and its level was found to increase at early stage of sporulation. The effects of 8-azaguanine examined, it was found to prevent spore formation and to made abnormal structure. The effects of inosinic monophosphate and guanosine monophosphate on spore formation were examined, spore formation was enhanced by these nucleotides.

• Korean Journal of Remote Sensing
• /
• v.30 no.6
• /
• pp.777-786
• /
• 2014

Mt. Ontake is the second highest volcano in Japan. On 02:52 Universal Time Coordinated(UTC), 27th September 2014, Ontake volcano began on the large eruption without notice. Due to the recent eruption, 55 people were killed and around 70 people injured. Therefore, This paper performed numerical experiment to analyse damage effect of volcanic ash corresponding to Ontake volcano erupt. The forecast is based on the outputs of the HYSPLIT Model for volcanic ash. This model, which is based on the UM numerical weather prediction data. Also, a quantitative analysis of the ash dispersion area, it has been detected using satellite images from optical Communication, Ocean and Meterological Satellite-Geostationary Ocean Color Imager (COMS-GOCI) images. Then, the GOCI detected area and simulated ash dispersion area were compared and verified. As the result, the similarity showed the satisfactory result between the detected and simulated area. The concordance ratio between the numerical simulation results and the GOCI images was 38.72 % and 13.57 %, Also, the concordance ratio between the JMA results and the GOCI images was 9.05 % and 11.81 %. When the volcano eruptions, volcanic ash range of damages are wide more than other volcanic materials. Therefore, predicting ash dispersion studies are one of main way to reduce damages.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.32 no.1 s.55
• /
• pp.17-22
• /
• 2006

Phosphatidyiserine (PS) is a phospholipid which plays the structural role in membranes and serves as a cofactor of signaling enzymes for diverse cellular functions. In this study, we observed that topical treatment with PS significantly decreased trans-epidermal water loss (TEWL) induced by tape-stripping in hairless mice. Also, ceramides in epidermis were increased in PS-treated group compared to vehicle-treated one in vivo. the amounts of non-hydroxyl ceramide (NHCER) (1.4 fold) and glucosylceramide (glucosylCER) (1.6 fold), in the skin of hairless mice, were increased by topical treament with PS. Also, we demonstrated that PS stimulated keratinocyte differentiation. We observed that PS treatment morphologically altered normal human keratinocyte (NHK) from the proliferating phase to the differentiating one, suggesting that PS stimulated epidermal differentiation in NHK. We also showed that the expressions of the specific markers for epidermal differentiation, involucrin (INV) (3.5 fold up) and transglutaminase 1 (TG'ase 1) (3 fold up), were significantly increased by PS treatment, compared to untreated control in vitro. In addition, topical treatment with PS resulted in a progressive increase in INV and loricrin protein levels in vivo. In conclusion, we provide the first evidence for the physiological activities of PS in skin, and we suggest that PS strengthen the epidermal permeability harrier by stimulation of keratinocyte differentiation.

• Korean Journal of Plant Resources
• /
• v.12 no.2
• /
• pp.107-119
• /
• 1999

In this study, the induction regeneration of callus from immature embryo in trifoliata orange (Poncirus trifoliata RAFIN.) were accomplished. The embryogenic calli were induced from the immature embryo derived from seed when the calli were irradiated for 16hr at about 2,000 Lux in $\frac{1}{2}$ MS medium supplemented with 3% sucrose, and 44.4$\mu$M BA. Regeneration to whole plants was the most successful in MS medium containing 5.0$\mu$M BA. The yellowish callus was developed at 2 to 3 weeks of culture and the callus was changed from yellow to green at 5 to 6 weeks culture. In vitro regeneration was directly induced from embryogenic callus in MS medium containing 3% sucrose and 5.0$\mu$M BA. Multishoot was formed at 16 weeks culture. Moreover, when the root-formed plantlet was transplanted to soil, they grew to a whole plant. The compact cultured-cells were observed by light microscope after 4 weeks of cultivation and the embryogenic clumps were formed about the 5 weeks. At the same time, the neighboring cells were liquefied. In addition, differentiation of leaf and stem from the callus was observed after 12 weeks. The developed oil sacs and the profacicular cambium of the immature leaf were observed after 18 weeks. Therefore, we can see the considerable changes of cell arrangements according to the developmental stages of calli from trifoliata orange.

• Journal of Digestive Cancer Research
• /
• v.1 no.1
• /
• pp.48-51
• /
• 2013

We report an unusual case of postoperative early gastric cancer with liver metastasis mimicking pancreaticobiliary carcinoma. A 73-year-old man with early gastric cancer was transferred for endoscopic treatment. The patient underwent endoscopic submucosal dissection for the treatment of the early gastric cancer. The pathological diagnosis was adenocarcinoma with extension to the deep submucosa and some lymphatic invasion. Therefore, subsequent a subtotal gastrectomy was performed. The histological results demonstrated residual adenocarcinoma confined to the mucosa. The resection margin and lymph node metastasis were negative. Thus, he was closely monitored for recurrence every 6 months. After 2 years, he was suddenly suspected of developing liver metastasis and local recurrence. He received a liver biopsy, and the pathological result was poorly differentiated adenocarcinoma. Immunohistochemical staining suggested pancreaticobiliary carcinoma rather than metastatic adenocarcinoma from the stomach or colon, but primary focus was not found. We were sure that the recurrent stomach cancer metastasized to the liver because stomach cancer can show heterogeneous cytokeratin (CK) expression pattern with various histological features. Therefore, no single CK expression pattern has diagnostic value for distinguishing gastric carcinoma. The patient underwent chemotherapy for metastatic stomach cancer.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.1
• /
• pp.354-361
• /
• 2019

This study was conducted to understand the relationship between the clinical competency of nursing students and their adult attachment and self-differentiation of nursing students. Data collection was conducted from the third and fourth grade students who had experienced clinical practice in a nursing university at Daejeon, Chungcheong province in two nursing universities at Daejeon and Chungcheong province. Finally, 169 out of initial 200 questionnaires were used for analysis. The collected data were analyzed through descriptive statistics, Pearson's correlation effectiveness, and stepwise multiple regression using the SPSS Statistics 22 Windows program. Attachment avoidance in adult attachment was significantly correlated with self-differentiation (r=-240, p=.002) and clinical competency (r=-.237, p=.002). Clinical competency was significantly correlated with attachment avoidance (r=-.237, p=.002) and self-differentiation (r=.248, p=.001). The result of stepwise multiple regression indicates that self-differentiation and attachment avoidance (F=8.707, p<.001) predicts 8.4% in clinical competency. The most powerful predictor was self-differentiation (${\beta}=.203$, p=.008), followed by attachment avoidance (${\beta}=.188$, p=.0015). Therefore, in order to improve the clinical competency of nursing college students, it is deemed necessary to develop and apply educational and counseling programs capable of increasing their level of self-differentiation while decreasing their degree of attachment avoidance.

• Journal of Life Science
• /
• v.8 no.6
• /
• pp.623-626
• /
• 1998

Conditions for somatic embryogenesis and plant regeneration from stem tissues of Euphorbia pulcherrima were esta-blished. Explants from leaf, petiole, stem were examined for their embryogenesis on MS solid medium supplemented with plant growth hormones in combination at various concentrations. From leaf or petiole explants, callus was indu-ced well but never proceeded to the embryonic stage in our expermental conditions. From stem explants, however, multiple shoots following callus induction emerged in about 6 to 8 weeks on MS agar medium supplemented with 1.5 mg/L of benzyladenine. Upon transfer, roots were developed on hormone-free MS solid medium.

• Korean Journal of Food Science and Technology
• /
• v.50 no.6
• /
• pp.688-696
• /
• 2018

This study aimed to investigate the effects of red ginseng-derived saponin fraction (SF) on lipid accumulation, reactive oxygen species (ROS) production, and nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1) signaling during adipocyte differentiation. SF effectively inhibited lipid accumulation, with the downregulation of adipogenic factors such as peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) and CCAAT/enhancer-binding protein alpha ($C/EBP{\alpha}$). A high dose of SF decreased the protein levels of $PPAR{\gamma}$ and $C/EBP{\alpha}$ by over 90% compared to the control. SF-mediated downregulation of adipogenic factors was due to the regulation of early adipogenic factors including $C/EBP{\beta}$ and $Kr{\ddot{u}}ppel$-like Factor 2 (KLF2). In addition, SF ($200{\mu}g/mg$) decreased intracellular ROS generation by 40% during adipocyte differentiation. However, the SF significantly upregulated Nrf2 and its target proteins, hemoxygenase-1 (HO-1) and NADPH dehydrogenase quinone 1 (NQO1). Furthermore, SF ($200{\mu}g/mg$) promoted the nuclear translocation of Nrf2. The SF-mediated reduction of lipid accumulation was associated with the regulation of the Nrf2/Keap1 pathway.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.24 no.3
• /
• pp.75-79
• /
• 1979

These studies were designed to define the effects of temperature on the vegetative growth of the korean ginseng, the induction and growth of the ginseng callus and organ differentiation from the callus of ginseng. At the temperature over $25^{\circ}C$. the plant growth of ginseng was significantly decreased and the chlorophyll in the .central parts of leaflets was deteriorated. Induction and growth of the ginseng callus was best at $25^{\circ}C$. High temperature of $29^{\circ}C$ promoted the initiation of roots from callus tissue but the shoot was not initiated at the temperature over $25^{\circ}C$. Shoots initiation from the ginseng callus occurred at $21^{\circ}C$ or lower temperature.