• Title/Summary/Keyword: Day of the Week Effect

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Semiweekly variation of Spring Phytoplankton Community in Relation to the Freshwater Discharges from Keum River Estuarine Weir, Korea (금강하구언 담수방류와 춘계 식물플랑크톤 군집의 단주기 변동)

  • Yih, Won-Ho;Myung, Geum-Og;Yoo, Yeong-Du;Kim, Young-Geel;Jeong, Hae-Jm
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.10 no.3
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    • pp.154-163
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    • 2005
  • Irregular discharges of freshwater through the water gates of the Keum River Estuarine Weir, Korea, whose construction had been completed in 1998 with its water gates being operated as late as August 1994, drastically modified the estuarine environment. Sharp decrease of salinity along with the altered concentrations of inorganic nutrients are accompanied with the irregular discharges of freshwater into the estuary under the influence of regular semi-diurnal tidal effect. Field sampling was carried out on the time of high tide at 2 fixed stations(St.1 near the Estuarine Weir and St.2 off Kunsan Ferry Station) every other day for 4 months from mid-February 2004 to investigate into the semi-weekly variation of spring phytoplankton community in relation to the freshwater discharges from Keum River Estuarine Weir. CV(coefficient of variation) of salinity measurements was roughly 2 times greater in St.1 than that in St.2, reflecting extreme salinity variation in St.1 Among inorganic nutrients, concentrations of N-nutrients($NO_3^-,\;NO_2^-$ and $NH_4^+$) were clearly higher in St.1, to imply the more drastic changes of the nutrient concentrations in St.1. than St.2 following the freshwater discharges. As a component of phytoplankton community, diatoms were among the top dominants in terms of species richness as well as biomass. Solitary centric diatom, Cyclotella meneghiniana, and chain-forming centric diatom, Skeletonema costatum, dominated over the phytoplankton community in order for S-6 weeks each (Succession Interval I and II), and the latter succeeded to the former from the time of <$10^{\circ}C$ of water temperature. Cyanobacterial species, Aphanizomenon Posaquae and Phormidium sp., which might be transported into the estuary along with the discharged freshwater, occupied high portion of total biomass during Succession Interval III(mid-April to late-May). During this period, freshwater species exclusively dominated over the phytoplankton community except the low concentrations of the co-occurring 2 estuarine diatoms, Cyclotella meneghiniana and Skeletonema costatum. During the 4th Succession Interval when the water temperature was over $18^{\circ}C$, the diatom, Guinardia delicatula, was predominant for a week with the highest dominance of $75\%$ in discrete samples. To summarize, during all the Succession Intervals other than Succession Interval III characterized by the extreme variation of salinity under cooler water temperature than $18^{\circ}C$, the diatoms were the most important dominants for species succession in spring. If the scale and frequency of the freshwater discharge could have been adjusted properly even during the Succession Interval III, the dominant species would quite possibly be replaced by other estuarine diatom species rather than the two freshwater cyanobacteria, Aphanizomenon flosaquae and Phormidium sp.. The scheme of field sampling every other day for the present study was concluded to be the minimal requirement in order to adequately explore the phytoplankton succession in such estuarine environment as in Keum River Estuary: which is stressed by the unpredictable and unavoidable discharges of freshwater under the regular semi-diurnal tide.

Effects of the time, and the rate of potassium fertilization at nursery stage on the rooting activity in paddy rice plant (수도(水稻)의 발근(發根)에 미치는 묘대가리시용(苗垈加里施用)의 영향(影響))

  • Lee, E.W.;Lee, C.Y.;Kwon, Y.W.
    • Applied Biological Chemistry
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    • v.9
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    • pp.119-124
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    • 1968
  • In order to learn the effect of timing and rate of potash fertilization in the rice plant nursery on the root growth and the vegetative growth of later stage a pot experiment was carried out employing 'Jaekun' a rice variety. Potassium Chloride was applied at the rate of $0{\sim}100g\;K_{2}O/3.3m^2$ right before, and 30 days after seeding. Forty-day old seedlings were transplanted three times successively at the one week intervals with the roots cut each time. Each subject was observed in rooting and other useful traits. A part of seedlings after the third root scission were cultured intact thereafter and the yield characters examined. The results were shown as: 1. The rate of sound seedlings was high in the case that a small amount of potassium was applied as the basic placement while the application of the fertilizer over $75g/3.3m^2$ (as $K_{2}O$) yielded a far less crops. 2. The plant height, number of tillers, number of leaves, and grass weight increased as the amount of potassium was elevated. However, the application of $50g\;K_{2}O/3.3m^2$ in the basic placement and that of $75g\;K_{2}O/3.3m^2$ were the peaks over which the above mentioned characters were weakened. 3. As the amount of potassium was increased the increment in number of rooting was notable, especially when the scission of roots was repeated within the limit of $50{\sim}75g\;K_{2}O/3.3m^2$. 4. In the maximum root newly shooted length indicated was about the same tendency although no statistical significance was observed. 5. The plant height, number of tillers, and variation of weight between grass and root indicated a similar tendency as the number of root shoot. 6. The differences in number of ears, grain yield, and weight of straw between the treatments were not so great but showed somewhat similar trend as in the growth of transplanted plants. In the treatment-100g $K_{2}O/3.3m^2$ the yield (ears, grain and straw) decreased as in the non-fertilized.

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EFFECT OF NERVE GROWTH FACTOR GENE INJECTION ON THE NERVE REGENERATION IN RAT LINGUAL NERVE CRUSH-INJURY MODEL (백서 설신경 압박손상모델에서 신경성장인자 유전자 주입이 신경재생에 미치는 영향)

  • Gao, En-Feng;Chung, Hun-Jong;Ahn, Kang-Min;Kim, Soung-Min;Kim, Yun-Hee;Jahng, Jeong-Won;Lee, Jong-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.28 no.5
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    • pp.375-395
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    • 2006
  • Purpose: Lingual nerve (LN) damage may be caused by either tumor resection or injury such as wisdom tooth extraction, Although autologous nerve graft is sometimes used to repair the damaged nerve, it has the disadvantage of necessity of another operation for nerve harvesting. Moreover, the results of nerve grafting is not satisfactory. The nerve growth factor (NGF) is well-known to play a critical role in peripheral nerve regeneration and its local delivery to the injured nerve has been continuously tried to enhance nerve regeneration. However, its application has limitations like repeated administration due to short half life of 30 minutes and an in vivo delivery model must allow for direct and local delivery. The aim of this study was to construct a well-functioning $rhNGF-{\beta}$ adenovirus for the ultimate development of improved method to promote peripheral nerve regeneration with enhanced and extended secretion of hNGF from the injured nerve by injecting $rhNGF-{\beta}$ gene directly into crush-injured LN in rat model. Materials and Methods: $hNGF-{\beta}$ gene was prepared from fetal brain cDNA library and cloned into E1/E3 deleted adenoviral vector which contains green fluorescence protein (GFP) gene as a reporter. After large scale production and purification of $rhNGF-{\beta}$ adenovirus, transfection efficiency and its expression at various cells (primary cultured Schwann cells, HEK293 cells, Schwann cell lines, NIH3T3 and CRH cells) were evaluated by fluorescent microscopy, RT-PCR, ELISA, immunocytochemistry. Furthermore, the function of rhNGF-beta, which was secreted from various cells infected with $rhNGF-{\beta}$ adenovirus, was evaluated using neuritogenesis of PC-12 cells. For in vivo evaluation of efficacy of $rhNGF-{\beta}$ adenovirus, the LNs of 8-week old rats were exposed and crush-injured with a small hemostat for 10 seconds. After the injury, $rhNGF-{\beta}$ adenovirus($2{\mu}l,\;1.5{\times}10^{11}pfu$) or saline was administered into the crushed site in the experimental (n=24) and the control group (n=24), respectively. Sham operation of another group of rats (n=9) was performed without administration of either saline or adenovirus. The taste recovery and the change of fungiform papilla were studied at 1, 2, 3 and 4 weeks. Each of the 6 animals was tested with different solutions (0.1M NaCl, 0.1M sucrose, 0.01M QHCl, or 0.01M HCl) by two-bottle test paradigm and the number of papilla was counted using SEM picture of tongue dorsum. LN was explored at the same interval as taste study and evaluated electro-physiologically (peak voltage and nerve conduction velocity) and histomorphometrically (axon count, myelin thickness). Results: The recombinant adenovirus vector carrying $rhNGF-{\beta}$ was constructed and confirmed by restriction endonuclease analysis and DNA sequence analysis. GFP expression was observed in 90% of $rhNGF-{\beta}$ adenovirus infected cells compared with uninfected cells. Total mRNA isolated from $rhNGF-{\beta}$ adenovirus infected cells showed strong RT-PCR band, however uninfected or LacZ recombinant adenovirus infected cells did not. NGF quantification by ELISA showed a maximal release of $18865.4{\pm}310.9pg/ml$ NGF at the 4th day and stably continued till 14 days by $rhNGF-{\beta}$ adenovirus infected Schwann cells. PC-12 cells exposed to media with $rhNGF-{\beta}$ adenovirus infected Schwann cell revealed at the same level of neurite-extension as the commercial NGF did. $rhNGF-{\beta}$ adenovirus injected experimental groups in comparison to the control group exhibited different taste preference ratio. Salty, sweet and sour taste preference ratio were significantly different after 2 weeks from the beginning of the experiment, which were similar to the sham group, but not to the control group.

Post-Exposure Prophylaxis of Varicella in Family Contact by Oral Acyclovir (가족 내 수두 환자와 접촉 후 경구 Acyclovir의 예방효과)

  • Kim, Sang Hee;Kim, Jong Hyun;Oh, Jin Hee;Hur, Jae Kyun;Kang, Jin Han;Koh, Dae Kyun
    • Pediatric Infection and Vaccine
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    • v.9 no.1
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    • pp.61-66
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    • 2002
  • Purpose : To determine wether varicella can be prevented by administration of oral acyclovir(ACV) during the incubation period of the disease. Methods : Starting 9 days after exposure to the index case in their families, ACV(40 mg/kg/day in four divided doses) was given orally to 20 exposed children for 5 days. Their clinical features was compared with those of 20 control subjects. Antibody titers to VZV were measured in both group 1 week and 4 weeks after finishing the oral ACV administration. Results : The mean age of family members with varicella(51.4 months) were significantly high compared to that of ACV prophylaxis group(28.5 months) and control group(31 months) (P<0.05). Among the 12 children with ACV prophylaxis who completed follow up blood sampling, nine children were diagnosed as VZV infection on the serologic test(75%). Among them six children showed positive VZV IgM on the first blood sample and two children showed serocoversion to positive IgM on the second test after ACV prophylaxis. One child who was negative on both IgM and IgG, showed positive IgG on the second test. The incidence of fever and severity of skin rashes were significantly low in children received oral ACV than in the control group. No or reduced number of maculopapular eruption were observed in the oral ACV group compared to multiple vesicles of the control group. Conclusion : In the present study, we observed that oral ACV prophylaxis to the family contacts is effective in reducing severity of skin lesion. It is likely that oral ACV 9 days after contact prevents or reduces blood dissemination of VZV. Little is known about clinical effect and immunity to the virus in exposed children with no varicella symptom after treatment. We propose the checking up antibody to VZV some period after oral ACV, and considering vaccination to whom with no antibody. But further more studies are needed to practical application of oral ACV for the postexposure prophylaxis of varicella.

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Variability in Drug Interaction According to Genetic Polymorphisms in Drug Metabolizing Enzymes

  • Jang, In-Jin;Yu, Kyung-Sang;Cho, Joo-Youn;Chung, Jae-Yong;Kim, Jung-Ryul;Lim, Hyeong-Seok;Shin, Sang-Goo
    • Environmental Mutagens and Carcinogens
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    • v.24 no.1
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    • pp.15-18
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    • 2004
  • There are significant differences in the extent of drug interactions between subjects. The influence of the genetic make up of drug metabolizing enzyme activities (CYP3A5, CYP2C19 and UDP-glucuronosyl transferase) on the pharmacokinetic drug interaction potential were studied in vivo. Nineteen healthy volunteers were grouped with regard to the $CYP3A5^{*}3$ allele, into homozygous wild-type (CYP3A5^{*}1/1^{*}1$, n=6), heterozygous $(CYP3A5^{*}1/^{*}3$, n=6), and homozygous variant-type $(CYP3A5^{*}3/^{*}3$, n=7) subject groups. The pharmacokinetic profile of intravenous midazolam was characterized before and after itraconazole administration (200 mg once daily for 4 days), and also following rifampin pretreatment (600 mg once daily for 10 days), with a washout period of 2 weeks in between. For omeprazole and moclobemide pharmacokinetic interaction study 16 healthy volunteers were recruited. The volunteer group comprised 8 extensive metabolizers and 8 poor metabolizers of CYP2C19, which was confirmed by genotyping. Subjects were randomly allocated into two sequence groups, and a single-blind, placebo-controlled, two-period crossover study was performed. In study I, a placebo was orally administered for 7 days. On the eighth morning, 300 mg of moclobemide and 40 mg of placebo were coadministered with 200 mL of water, and a pharmacokinetic study was performed. During study n, 40 mg of omeprazole was given each morning instead of placebo, and pharmacokinetic studies were performed on the first and eighth day with 300 mg of moclobemide coadministration. In the UGT study pharmacokinetics and dynamics of 2 mg intravenous lorazepam were evaluated before and after rifampin pretreatment (600 mg once daily for 10 days), with a washout period of 2 weeks in between. The subjective and objective pharmacodynamic tests were done before and 1, 2, 4, 6, 8, and 12 hrs after lorazepam administration. The pharmacokinetic profiles of midazolam and of its hydroxy metabolites did not show differences between the genotype groups under basal and induced metabolic conditions. However, during the inhibited metabolic state, the $CYP3A5^{*}3/^{*}3$ group showed a greater decrease in systemic clearance than the $CYP3A5^{*}1/^{*}1$ group $(8.5\pm3.8$ L/h/70 kg vs. $13.5\pm2.7$ L/h/70 kg, P=0.027). The 1'-hydroxymidazolam to midazolam AUC ratio was also significantly lower in the $CYP3A5^{*}3/^{*}3$,/TEX> group $(0.58\pm0.35,$ vs. $1.09\pm0.37$ for the homozygous wild-type group, P=0.026). The inhibition of moclo-bemide metabolism was significant in extensive metabolizers even after a single dose of omeprazole. After daily administration of omeprazole for 1 week, the pharmacokinetic parameters of moclobemide and its metabolites in extensive metabolizers changed to values similar to those in poor metabolizers. In poor meta-bolizers, no remarkable changes in the pharmacokinetic parameters were observed. The area under the time-effect curves of visual analog scale(VAS), choice reaction time, and continuous line tracking test results of lorazepam was reduced by 20%, 7%, 23% respectively in induced state, and in spite of large interindividual variablity, significant statistical difference was shown in VAS(repeated measures ANOVA, p=0.0027).

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Variability in Drug Interaction According to Genetic Polymorph isms in Drug Metabolizing Enzymes

  • Jang, In-Jin;Yu, Kyung-Sang;Cho, Joo-Youn;Chung, Jae-Yong;Kim, Jung-Ryul;Lim, Hyeong-Seok;Shin, Sang-Goo
    • Environmental Mutagens and Carcinogens
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    • v.23 no.4
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    • pp.131-134
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    • 2003
  • There are significant differences in the extent of drug interactions between subjects. The influence of the genetic make up of drug metabolizing enzyme activities (CYP3A5, CYP2C19 and UDP-glucuronosyl transferase) on the pharmacokinetic drug interaction potential were studied in vivo. Nineteen healthy volunteers were grouped with regard to the $CYP3A5^{*}3$ allele, into homozygous wild-type (CYP3A5^{*}1/1^{*}1$, n=6), heterozygous $(CYP3A5^{*}1/^{*}3$, n=6), and homozygous variant-type $(CYP3A5^{*}3/^{*}3$, n=7) subject groups. The pharmacokinetic profile of intravenous midazolam was characterized before and after itraconazole administration (200 mg once daily for 4 days), and also following rifampin pretreatment (600 mg once daily for 10 days), with a washout period of 2 weeks in between. For omeprazole and moclobemide pharmacokinetic interaction study 16 healthy volunteers were recruited. The volunteer group comprised 8 extensive metabolizers and 8 poor metabolizers of CYP2C19, which was confirmed by genotyping. Subjects were randomly allocated into two sequence groups, and a single-blind, placebo-controlled, two-period crossover study was performed. In study I, a placebo was orally administered for 7 days. On the eighth morning, 300 mg of moclobemide and 40 mg of placebo were coadministered with 200 mL of water, and a pharmacokinetic study was performed. During study n, 40 mg of omeprazole was given each morning instead of placebo, and pharmacokinetic studies were performed on the first and eighth day with 300 mg of moclobemide coadministration. In the UGT study pharmacokinetics and dynamics of 2 mg intravenous lorazepam were evaluated before and after rifampin pretreatment (600 mg once daily for 10 days), with a washout period of 2 weeks in between. The subjective and objective pharmacodynamic tests were done before and 1, 2, 4, 6, 8, and 12 hrs after lorazepam administration. The pharmacokinetic profiles of midazolam and of its hydroxy metabolites did not show differences between the genotype groups under basal and induced metabolic conditions. However, during the inhibited metabolic state, the $CYP3A5^{*}3/^{*}3$ group showed a greater decrease in systemic clearance than the $CYP3A5^{*}1/^{*}1$ group $(8.5\pm3.8$ L/h/70 kg vs. $13.5\pm2.7$ L/h/70 kg, P=0.027). The 1'-hydroxymidazolam to midazolam AUC ratio was also significantly lower in the $CYP3A5^{*}3/^{*}3$,/TEX> group $(0.58\pm0.35,$ vs. $1.09\pm0.37$ for the homozygous wild-type group, P=0.026). The inhibition of moclo-bemide metabolism was significant in extensive metabolizers even after a single dose of omeprazole. After daily administration of omeprazole for 1 week, the pharmacokinetic parameters of moclobemide and its metabolites in extensive metabolizers changed to values similar to those in poor metabolizers. In poor meta-bolizers, no remarkable changes in the pharmacokinetic parameters were observed. The area under the time-effect curves of visual analog scale(VAS), choice reaction time, and continuous line tracking test results of lorazepam was reduced by 20%, 7%, 23% respectively in induced state, and in spite of large interindividual variablity, significant statistical difference was shown in VAS(repeated measures ANOVA, p=0.0027).

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Effects of 166Holmium and 166Holmium-chitosan Complex(166Ho-CHICO) on Normal Brain of Rats (홀뮴 및 홀뮴-키토산 복합체가 정상 백서 뇌에 미치는 효과에 대한 연구)

  • Sun, Jing He;Joh, Chul W;Ahn, Young Hwan;Park, Chan Hee;Shim, Chull;Park, Kyung Bae;Cho, Kyung Gi
    • Journal of Korean Neurosurgical Society
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    • v.29 no.10
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    • pp.1309-1315
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    • 2000
  • Objectives : We performed an in vivo experiment to investigate the effect of $^{166}Holmium$ and $^{166}Holmium$-chitosan complex($^{166}Ho$-CHICO) on the normal brain of rats and to determine the sublethal dose of $^{166}Ho$-CHICO. Materials and Methods : $^{166}Ho$ is a beta and gamma ray emitter. $^{166}Ho$-CHICO is a novel radio-pharmaceutical complex with chitosan to facilitate the transport of $^{166}Ho$ obtained from Korea Atomic Energy Research Center(Taejon, Korea). It is in acidic form and becomes gel state at alkaline pH. One hundred and seventy consecutive rats were divided into four groups : $^{166}Ho$ treated(n=50), $^{166}Ho$-CHICO treated(n=57), saline treated(n=5) and chitosan treated(n=5) groups. $^{166}Ho$ and $^{166}Ho$-CHICO were injected into the rat brain stereotactically with various doses of 0.1mCi/$20{\mu}l$, 0.2mCi/$20{\mu}l$, 0.3mCi/$20{\mu}l$, and 0.4mCi/$20{\mu}l$ using an automated microinjector. Nuclear imaging, histopathological and hematological studies were performed in 10 rats in each group at 1 day, 3days, 7 days, 1 month and 3 months after the injections. Results : An infiltration of inflammatory cells and necrotic changes were noted in $^{166}Ho$ treated group at 1 week after the injection. A wedge-shaped tissue defect due to necrosis, lined with infiltrated glial cells in $^{166}Ho$ treated group and a cystic defect lined with reactive astroglial cells in $^{166}Holmium$-CHICO treated group at 3 months after the injection were observed. $^{166}Ho$ alone without chitosan leaked out and caused necrotic lesion on the cerebral surface but $^{166}Holmium$-CHICO treated group did not show this feature. As the dose of $^{166}Ho$ increased, the mortality rates were also increased. The mortality rate of the $^{166}Holmium$-CHICO group was higher than the $^{166}Ho$ treated group at a dose of 0.4mCi/$20{\mu}l$/300g. There was no detectable radioactivity due to the leakage or extravasation from the injected site of the brain on the scintigraphy performed at 1 hour, 24 hours and 48 hours after the injection. There was also no detectable activity of $^{166}Holmium$-CHICO in other organs including spleen, liver and kidney. Conclusions : $^{166}Ho$-CHICO did not leak out to the critical cortical surface of the brain from the injection site and induced radiation changes of the parenchyma around the injection site without cortical damage. The sublethal dose of $^{166}Ho$-CHICO for the normal brain in rats was determined to be 0.2mCi/$20{\mu}l$/300g.

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Effect of treadmill exercise on autophagy related protein expression in the cardiac muscle of high-fat diet fed rats (트레드밀 운동이 고지방 식이 쥐 심근세포의 자가포식 관련 단백질 발현에 미치는 영향)

  • Jeong, Jae-Hoon;Kang, Eun-Bum
    • Journal of the Korean Applied Science and Technology
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    • v.37 no.1
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    • pp.91-101
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    • 2020
  • The purpose of this study was to investigate the influence of obesity on the expression of autophagy-related proteins in cardiac muscle. To this end, obesity was induced in rats through 20 weeks of high-fat diet, and the animals were then subjected to 8 weeks of treadmill exercise. Subsequently, the expression of proteins that regulate the induction of autophagy, formation of autophagosome, and fusion of autophagosome and lysosome was confirmed. Obesity was induced in the experimental animals (SD rats) through 20 weeks of high-fat diet (carbohydrate: 20%, fat: 60%, and protein: 20%), and they were subsequently subjected to 8 weeks of treadmill exercise (5 days/week, 30 min/day, 5 minutes; 8m/min, 5 minutes; 11m/min, 20 minutes; 14m/min). The experimental groups comprised the normal diet control group (ND-CON, n=10), high-fat diet comparison group (HFD-CON, n=10), and high-fat exercise group (HFD-TE, n=10). Oral glucose tolerance test was conducted before and after 8 weeks of treadmill exercise, and the area under the curve (AUC) was calculated. Through fasting insulin and fasting glucose levels, HOMA-IR, which is an index of insulin resistance, and abdominal visceral fat/body weight (AVF/BW) were calculated for comparison. Moreover, autophagy-related proteins were analyzed from cardiac tissue to investigate the effects of exercise training. Obesity was successfully induced in the HFD-CON group through long-term high-fat diet, and the HFD-CON group had higher body weight, AUC, HOMA-IR, and AVF/BW compared to the ND-CON group. The HFD-TE group, which underwent 8 weeks of treadmill exercise, showed improvements in AUC, HOMA-IR, and AVF/BW. Although the body weight tended to decrease as well, there was no statistically significant difference. mTOR and AMPK, which are involved in the induction of autophagy, both decreased in obesity but increased upon exercise. Beclin-1, BNIP3, ATG-7, p62, and LC3, which are related to the formation of autophagosomes, all increased in obesity and decreased after exercise. Cathepsin L and LAMP2, which regulate the fusion of autophagosome and lysosome, both decreased in obesity and increased upon exercise. Physical activity, including treadmill exercise, was found to induce normal autophagy and improve pathological phenomena observed in metabolic diseases. Therefore, the findings suggest the need to consider treadmill exercise as a primary means to achieve effective prevention and treatment of cardiac diseases.

Growth and Flower Bud Induction in Strawberry 'Sulhyang' Runner Plant as Affected by Exogenous Application of Benzyladenine, Gibberellic Acid, and Salicylic Acid (벤질아데닌, 지베렐린산, 살리실산이 '설향' 딸기묘의 생장과 화아 유도에 미치는 영향)

  • Thi, Luc The;Nguyen, Quan Hoang;Park, Yoo Gyeong;Jeong, Byoung Ryong
    • Journal of Bio-Environment Control
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    • v.28 no.2
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    • pp.178-184
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    • 2019
  • Strawberry ($Fragaria{\times}ananassa$) is one of the most important and popular fruit crops in the world, and 'Sulhyang' is one of the principal cultivars cultivated in the Republic of Korea for the domestic market. The growth and flower induction in strawberry is the process which influences directly on fruit bearing and yield of this crop. In this study, effect of benzyladenine (BA), gibberellic acid ($GA_3$), and salicylic acid (SA) on growth and flower bud induction in strawberry 'Sulhyang' was investigated. The 3-week-old runner plants, grown in 21-cell propagation trays, were potted and cultivated in growth chambers with $25^{\circ}C/15^{\circ}C$ (day/night) temperatures, 70% relative humidity (RH), and light intensity of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux density (PPFD) provided by white light emitting diodes (LEDs). The runner plants were treated with one of three concentrations, 0 (control), 100, and $200mg{\cdot}L^{-1}$ of BA, $GA_3$, or SA solution. The chemicals were sprayed two times on leaves of runner plants at an interval of two weeks. After 9 weeks the results showed that the application of all chemicals caused reduction of root length and chlorophyll (SPAD) content as compared to the control. The lowest chlorophyll (SPAD) content was recorded in plants treated with $GA_3$. However, the treatment of $200mg{\cdot}L^{-1}$ $GA_3$ promoted leaf area, leaf fresh weight, and plant fresh weight. The greatest flower induction (85%) and number of inflorescences (4.3 inflorescences per plant) were observed in the treatment of $200mg{\cdot}L^{-1}\;SA$, followed by $100mg{\cdot}L^{-1}\;SA$. Overall, results suggest that foliar application of $GA_3$ solution could accelerate plant growth, while foliar application of SA solution could induce hastened flowering. Further studies may be needed to find out the relationship between $GA_3$ and SA solutions treated in a combination, and the molecular mechanism involved in those responses observed.

Effect of Oral Administration of Egg Yolk on Cholesterol Metabolism in Rats (난황 경구투여가 랫드의 콜레스테롤 대사에 미치는 영향)

  • Bang, Han-Tae;Hwangbo, Jong;Park, Sang-Oh;Park, Byung-Sung
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.2
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    • pp.255-264
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    • 2014
  • This study was performed to elucidate the biochemical mechanism of metabolism on reducing blood lipid, by oral administration of egg yolk in rats. A total of 36 Sprague Dawley male rats were randomized into four treatment groups, according to a randomized block design. Each group was further divided into three repeat cages, with each repeat cage comprising of 3 rats. The animals were orally administered with egg yolk once a day, while feeding the same purified pellet diet for 6 weeks. The four treatment groups were: C(control, saline 1.0 g), T1(pork belly oil 1.0 g), T2(egg yolk 1.0 g), T3(pork belly oil 1.0 g and egg yolk 1.0 g alternating every week). The measured parameters in each group are listed as follows in the order of highest to the lowest: daily average gain of body weight(T1>T3>T2>C); blood triglyceride and total cholesterol(T1>C>T3>T2) HDL-C (T2>C>T3>T1); and LDL-C (T1>T3>C>T2). AST and ALT, which are the index of liver function, were the highest in T1 but was lowest in T2. The weights of the liver, spleen, and kidney, except for the abdominal fat, showed no significant difference. The weight of abdominal fat was the highest in T1, but there were no significant difference among C, T2, and T3. The HMG-CoA reductase activity was the highest in T1 followed by T3, C but T2 was lowest. The daily fecal excretions of the total sterol, neutral sterol and acid sterol was highest in T2 but lowest in T1. The results of this study show that the egg consumption reduces the blood lipid through facilitation of fecal excretions of sterols and inhibition of enzyme activity in cholesterol biosynthesis, in the liver of animal and human.