• Korean Journal of Agricultural and Forest Meteorology
• /
• v.4 no.4
• /
• pp.213-218
• /
• 2002

The use of biological indicator for environmental monitoring has suddenly become popular in many international organizations as well as domestic ones. Since the biological indicator species should be well responsive to native environmental change, development of native indicator species is prerequisite for environmental assessment and restoration program. Through regression analysis of mean density and pH, potential indicator species were screened from Namsan and Kwangreung where differential environmental stresses are influenced; Lasiobelba remota, Ceratozetes sp. Tectocepheus velatus, Neogymnobates sp. and Oppia sp.3. Also keystone species in two study area were Lohmannia coreana, Ceratozetes sp., Rostrozetes pulcherrimus, and Lasiobelba remota in Namsan Deciduous forest and Neogymnobates sp., Neogymnobates donghaksaensis, and Cultroribula tridentata in Kwangreung. Advantages and disadvantages of using biological indicator for environmental monitoring were further discussed.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.4
• /
• pp.563-567
• /
• 2006

Two experiments were conducted to compare the effect of various vitamins on performance and digestibility in growing pigs. In experiment 1, a total of 54 pigs ($L{\times}Y{\times}D$, $42.73{\pm}2.40kg$) were assigned to three treatments in a randomized complete block design with three replicates (6 pigs/pen) for 40 days. The three dietary treatments were: 100% fat-soluble vitamins (FSV) and water-soluble vitamins (WSV); 150% FSV and 100% WSV of NRC (1998); and 100% FSV and 150% WSV of NRC (1998). In experiment 2, a total of 180 pigs ($L{\times}Y{\times}D$, $28.20{\pm}3.05 kg$) were assigned to four treatments in a completely randomized design with three replicates for four weeks (15 pigs/pen). The four dietary treatments were, 150% vitamin A and 100% other vitamins, 150% vitamin D and 100% other vitamins, 150% vitamin E and 100% other vitamins, and 150% vitamin K and 100% other vitamins. In experiment 1, there were significant differences in growth performance and digestibility of nutrients among the treatments. The ADG, ADFI and FCR of pigs fed 150% FSV diet were better (p<0.05) than those fed the control diet. However, there were no differences (p>0.05) in ADG, ADFI and FCR between pigs fed the control and 150% WSV diets. Digestibilities of dry matter, gross energy and calcium were improved in 150% FSV treatment group compared with control (p<0.05). However, the improvement was similar when compared with 150% WSV except for Ca. In experiment 2, there were no differences (p>0.05) in ADG, ADFI and FCR and nutrient digestibility between the fat-soluble vitamin treatments when fed at the 150% level. In conclusion, growing pigs were more responsive to additional fat-soluble vitamin supplements over the requirements suggested by NRC (1998) than to water-soluble vitamin supplements as measured by growth performance and digestibility of nutrients.

• Journal of Nutrition and Health
• /
• v.17 no.4
• /
• pp.313-319
• /
• 1984

The effect of morphine on food intake on freely fed Sprague - Dawley rats was examined Opiate receptor binding assay was used to investigate the possibility of the opioid system involved in food intake regulation of normal rats. When rats were treated with 5mg morphine per kg body weight, subcutaneously, the food intake of the rats for the first 2 hours was increased 125% of the control rats. The effect of morphine on food intake of male and female rats were greater when the morphine was injected at 10 : 00 a.m than that in the rats administered the morphine at 4 : 00 p.m. The morphine effect was not significant in older rats and female was more responsive than male rats. In morphine treated rats, opioid receptor density has exhibited 33% reduction as measured by the $^{3}H-naloxone$ binding assay with whole brain homogenate. These results indicate that the increase of food intake by morphine for 2 hours after the injection may be mediated through the opioid system in rat brain.

• Journal of Biomedical Engineering Research
• /
• v.41 no.6
• /
• pp.228-234
• /
• 2020

Superparamagnetic iron oxide nanoparticles (SPIONs) are approved by the Food and Drug Administration (FDA) in the United States. SPIONs are used in magnetic resonance imaging (MRI) as contrast agents and targeted delivery in nanomedicine using external magnet sources. SPIONs act as an artificial peroxidase (i.e., nanozyme), and these reactions were highly stable in various pH conditions and temperatures. In this study, we report a nanozyme ability of the clustered SPIONs (CSPIONs) synthesized by the oil-in-water (O/W) method and coated with biocompatible poly(lactic-co-glycolic acid) (PLGA). We hypothesize that the CSPIONs can have high sensitivity toward H2O2 derived from the reaction between a fixed amount of glucose and glucose oxidase (GOX). As a result, CSPIONs oxidized a 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) commonly used as a substrate for hydrogen peroxidase in the presence of H2O2, leading to a change in the color of the substrate. We also utilized a colorimetric assay at 417 nm using various glucose concentrations from 5 mM to 1.25 μM to validate β-D-glucose detection. This study demonstrated that the absorbance value increases along with increasing the glucose level. The results were highly repeated at concentrations below 5 mM (all standard deviations < 0.03). Moreover, the sensitivity and limit of detection were 1.50 and 5.44 μM, respectively, in which CSPIONs are more responsive to glucose than SPIONs. In conclusion, this study suggests that CSPIONs have the potential to be used for glucose detection in diabetic patients using a physiological fluid such as ocular, saliva, and urine.

• Microbiology and Biotechnology Letters
• /
• v.46 no.1
• /
• pp.29-39
• /
• 2018

Vibrio vulnificus needs various responsive mechanisms to survive and transmit successfully in alternative niches of human and marine environments, and to ensure the acquisition of steady energy supply to facilitate such unique life style. The bacterium had genetic constitution very different from that of Escherichia coli regarding metabolism of glycogen, a major energy reserve. V. vulnificus accumulated more glycogen than other bacteria and at various levels according to culture medium and carbon source supplied in excess. Glycogen was accumulated to the highest level in Luria-Bertani (3.08 mg/mg protein) and heart infusion (4.30 mg/mg protein) complex media supplemented with 1% (w/v) maltodextrin at 3 h into the stationary phase. Regarding effect of carbon source, more glycogen was accumulated when maltodextrin (2.34 mg/mg protein) was added than when glucose or maltose (0.78.1-14 mg/mg protein) was added as an excessive carbon source to M9 minimal medium, suggesting that maltodextrin metabolism might affect glycogen metabolism very closely. These results were supported by the analysis using the malP (encoding a maltodextrin phosphorylase) and malQ (encoding a 4-${\alpha}$-glucanotransferase) mutants, which accumulated much less glycogen than wild type when either glucose or maltodextrin was supplied as an excessive carbon source, but at different levels (3.1-80.3% of wild type glycogen). Therefore, multiple pathways for glycogen metabolism were likely to function in V. vulnificus and that responding to maltodextrin might be more efficient in synthesizing glycogen. All of the glycogen samples from 3 V. vulnificus strains under various conditions showed a narrow side chain length distribution with short chains (G4-G6) as major ones. Not only the comparatively large accumulation volume but also the structure of glycogen in V. vulnificus, compared to other bacteria, may explain durability of the bacterium in external environment.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.7 no.2
• /
• pp.156-163
• /
• 2005

This study was conducted to compare the physiological and biochemical responses of P. orientalis and L. tulipifera in response to ozone. One-year-old seedlings of P. orientalis and L. tulipifera were exposed to 100 ppb ozone concentration for 2, 4, or 8 hr/day for 1 week. Photosynthesis, stomatal conductance and ozone uptake rate were measured daily, and chlorophyll fluorescence, carboxylation efficiency, chlorophyll content, and SOD activity were measured after 1 week. In P. orientalis, photosynthesis and stomatal conductance were not decreased in the 2h/day ozone treatment, but the L. tulipifera response was more sensitive even in the 2h/day ozone treatment. Increased treatment time decreased photosynthesis and stomatal conductance. Chlorophyll fluorescence was not significantly different among treatment times. However, carboxylation efficiency decreased with increased treatment time, and L. tulipifera was more sensitive than P. orientalis. Chlorophyll content did not differ with species or treatment time. SOD activity response was greater in L. tulipifera than in P. orientalis, increasing to $131\%$ of pretreatment observations. Therefore it was concluded that L. tulipifera was more responsive and had lower ozone tolerance than P. orientalis.

• Korean Journal of Microbiology
• /
• v.52 no.1
• /
• pp.1-9
• /
• 2016

A unique Schizosaccharomyces pombe $TrxR^+$ gene encoding thioredoxin reductase (TrxR) was found to be positively regulated by stress-inducing agents through the stress-responsive transcription factor Pap1. In the present study, the protective roles of S. pombe TrxR were evaluated using the TrxR-overexpressing recombinant plasmid pHSM10. In the presence of hydrogen peroxide ($H_2O_2$) and superoxide anion-generating menadione (MD), S. pombe TrxR increased cellular growth and the total glutathione (GSH) level, while it reduced levels of intracellular reactive oxygen species (ROS). The nitric oxide (NO) levels of the TrxR-overexpressing cells, in the presence of $H_2O_2$ and MD, were maintained to be similar to those of the corresponding non-treated cells. Although S. pombe TrxR was able to scavenge NO generated by sodium nitroprusside (SNP), it had no significant modulating effects on cellular growth, ROS levels, or the total GSH level of SNP-exposed yeast cells, compared with the differences in those of the two non-treated cell cultures. TrxR increased the cellular growth and total GSH level, which were diminished by nitrogen starvation. It also scavenged ROS and NO produced during nitrogen starvation. Taken together, the S. pombe TrxR protects against oxidative, nitrosative, and nutritional stresses.

• Horticultural Science & Technology
• /
• v.34 no.1
• /
• pp.102-111
• /
• 2016

The goal of this study was to characterize the BrDSR (Drought Stress Resistance in B. rapa) gene and to identify the expression network of drought-inducible genes in Chinese cabbage under drought stress. Agrobacterium-mediated transformation was conducted using a B. rapa inbred line ('CT001') and the pSL100 vector containing the BrDSR full length CDS (438 bp open reading frame). Four transgenic plants were selected by PCR and the expression level of BrDSR was approximately 1.9-3.4-fold greater than that in the wild-type control under drought stress. Phenotypic characteristics showed that BrDSR over-expressing plants were resistant to drought stress and showed normal growth habit. To construct a co-expression network of drought-responsive genes, B. rapa 135K cDNA microarray data was analyzed to identify genes associated with BrDSR. BrDSR was directly linked to DARK INDUCIBLE 2 (DIN2, AT3G60140) and AUTOPHAGY 8H (ATG8H, AT3G06420) previously reported to be leaf senescence and autophagy-related genes in plants. Taken together, the results of this study indicated that BrDSR plays a significant role in enhancement of tolerance to drought conditions.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.4
• /
• pp.446-450
• /
• 2000

The experiment was conducted to study the effects of water soluble vitamins and retinoic acid on the differentiation of preadipocyte from omental, subcutaneous, intermuscular and intramuscular adipose tissue of Hanwoo. Differentiation was assessed by the change in enzyme activity, glycerol-3 phosphate dehydrogenase in serum free cell culture system. Preadipocytes treated with biotin ($10{\mu}M$) and pantothenic acid ($100{\mu}M$) were significantly (p<0.05) less differentiated than those from the control in all adipose tissue depots except intramuscular tissue. Although there was no significance, vitamin C was shown to stimulate the adipocyte conversion in omental and subcutaneous, but not in intermuscular and intramuscular adipose tissues. Lower values of GPDH activity in intermuscular preadipocyte were interpreted to be caused by relatively higher amounts of protein. In this experiment vitamin C did not stimulate fat deposition in intramuscular adipose tissue but further experiments are needed on the role of vitamin C in preadipocyte differentiation. When treated with different levels of retinoic acids, differentiation of preadipocytes was significantly (p<0.05) reduced from the level of $0.5{\mu}g/ml$ in omental and intermuscular, from $50{\mu}g/ml$ in subcutaneous, and in intramuscular at $500{\mu}g/ml$, thus showing that intramuscular preadipocytes were least responsive to retinoic acid in differentiation. All-trans retinoic acid appeared to inhibit the differentiation in a dose dependent manner, regardless of adipose tissues type.

• Biomolecules & Therapeutics
• /
• v.28 no.6
• /
• pp.549-560
• /
• 2020

Although DNA damage responses (DDRs) are reported to be involved in nitric oxide (NO) production in response to genotoxic stresses, the precise mechanism of DDR-mediated NO production has not been fully understood. Using a genotoxic agent aphidicolin, we investigated how DDRs regulate NO production in bovine aortic endothelial cells. Prolonged (over 24 h) treatment with aphidicolin increased NO production and endothelial NO synthase (eNOS) protein expression, which was accompanied by increased eNOS dimer/monomer ratio, tetrahydrobiopterin levels, and eNOS mRNA expression. A promoter assay using 5'-serially deleted eNOS promoters revealed that Tax-responsive element site, located at -962 to -873 of the eNOS promoter, was responsible for aphidicolin-stimulated eNOS gene expression. Aphidicolin increased CREB activity and ectopic expression of dominant-negative inhibitor of CREB, A-CREB, repressed the stimulatory effects of aphidicolin on eNOS gene expression and its promoter activity. Co-treatment with LY294002 decreased the aphidicolin-stimulated increase in p-CREB-Ser¹³³ level, eNOS expression, and NO production. Furthermore, ectopic expression of dominant-negative Akt construct attenuated aphidicolin-stimulated NO production. Aphidicolin increased p-ATM-Ser¹⁹⁸¹ and the knockdown of ATM using siRNA attenuated all stimulatory effects of aphidicolin on p-Akt-Ser⁴⁷³, p-CREB-Ser¹³³, eNOS expression, and NO production. Additionally, these stimulatory effects of aphidicolin were similarly observed in human umbilical vein endothelial cells. Lastly, aphidicolin increased acetylcholine-induced vessel relaxation in rat aortas, which was accompanied by increased p-ATM-Ser¹⁹⁸¹, p-Akt-Ser⁴⁷³, p-CREB-Ser¹³³, and eNOS expression. In conclusion, our results demonstrate that in response to aphidicolin, activation of ATM/Akt/CREB/eNOS signaling cascade mediates increase of NO production and vessel relaxation in endothelial cells and rat aortas.