• Childhood Kidney Diseases
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• v.13 no.2
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• pp.99-117
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• 2009

Diabetic nephropathy is a major cause of chronic renal failure in developing countries, and the prevalence rate has markedly increased during the past decade. Diabetic nephropathy shows various specific histological changes not only in the glomeruli but also in the tubulointerstitial region. In the early stage, the effacement of podocyte foot processes and thickened glomerular basement membrane (GBM) is noticed even at the stage of microalbuminuria. Nodular, diffuse, and exudative lesions, so-called diabetic glomerulosclerosis, are well known as glomerular lesions. Interstitial lesions also exhibit fibrosis, edema, and thickened tubular basement membrane. Diabetic nephropathy is considered to be multifactorial in origin with increasing evidence that one of the major pathways involved in the development and progression of diabetic nephropathy as a result of hyperglycemia. Hyperglycemia induces renal damage directly or through hemodynamic alterations, such as, glomerular hyperfiltration, shear stress, and microalbuminuria. Chronic hyperglycemia also induces nonhemodynamic dysregulations, such as, increased production of advanced glycosylation endproducts, oxidative stress, activation of signal pathway, and subsequent various cytokines. Those pathogenic mechanisms resulted in extracellular matrix deposition including mesangial expansion and GBM thickening, glomerular hypertrophy, inflammation, and proteinuria. In this review, recent opinions on the histopathologic changes and pathophysiologic mechanisms leading to initiation and progression of diabetic nephropathy will be introduced.

• Journal of Life Science
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• v.28 no.10
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• pp.1233-1243
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• 2018

Sterol regulatory-element binding proteins (SREBPs) are a family of transcription factors that regulate lipid homeostasis and metabolism by controlling the expression of enzymes required for endogenous cholesterol, fatty acid (FA), triacylglycerol, and phospholipid synthesis. The three SREBPs are encoded by two different genes. The SREBP1 gene gives rise to SREBP-1a and SREBP-1c, which are derived from utilization of alternate promoters that yield transcripts in which distinct first exons are spliced to a common second exon. SREBP-2 is derived from a separate gene. Additionally, SREBPs are implicated in numerous pathogenic processes, such as endoplasmic reticulum stress, inflammation, autophagy, and apoptosis. They also contribute to obesity, dyslipidemia, diabetes mellitus, and nonalcoholic fatty liver diseases. Genome-wide analyses have revealed that these versatile transcription factors act as important nodes of biological signaling networks. Changes in cell metabolism and growth are reciprocally linked through SREBPs. Anabolic and growth signaling pathways branch off and connect to multiple steps of SREBP activation and form complex regulatory networks. SREBPs are activated through the PI3K-Akt-mTOR pathway in these processes, but the molecular mechanism remains to be understood. This review aims to provide a comprehensive understanding of the role of SREBPs in physiology and pathophysiology at the cell, organ, and organism levels.

• Journal of Yeungnam Medical Science
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• v.14 no.1
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• pp.46-52
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• 1997

Diaphragm is thought to play the most important role in breathing and has a substantially greater proportion of slow oxidative and fast glycolytic fibers, and low proportion of fast oxidative fibers. The respiratory muscle, diaphragm, has the functional characteristics of slow speed of contraction, high resistance to fatigue and the ability to respond to intermittent ventilatory loads, for example of exercise. In the present study, the characteristics of the metabolism (depletion and repletion) of glycogen and the structural changes of diaphragm during depletion and repletion of glycogen were observed in rats. For comparison, the red gastrocnemius muscle which has a greater proportion of fast oxidative glycolytic (FOG) and slow oxidative (SO) fibers, and low proportion of fast glycolytic (FG) fiber, was also studied. The glycogen concentration of diaphragm in overnight fasted rats was $2.30{\pm}0.14mg/gm$ wet weight. The values of glycogen concentration at 60, 90 and 120minutes of treadmill exercise loaded rats was significantly decreased compared to that of the overnight fasted rats. There was no significant difference among the glycogen concentrations of diaphragm at 60, 90 and 120minutes of exercises. The glycogen concentration of diaphragm was decreased to $1.12{\pm}0.17$ from $2.30{\pm}0.14mg/gm$ wet weight by treadmill exercise. The glycogen depletion rate of diaphragm during exercise was faster than that of red gastrocnemius in both of the first 60minutes and 120minutes duration of exercise. The glycogen repletion of diaphragm after intragastric glucose administration by stomach tube was studied in control and exercise groups. The glycogen concentration was significantly increased after glucose administration in both of control and exercise groups. All of the concentration of exercise group at 60, 120 and 180minutes after glucose administration was significantly higher than those of control group. In conclusion, one of the characteries of diaphragm in glycogen metabolism is fast glycogen depletion during exercise, and slowness of glycogen repletion after glucose ingestion in rats.

• Journal of Dairy Science and Biotechnology
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• v.33 no.2
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• pp.119-127
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• 2015

To date, detection of microbial populations in dairy products has been performed using culture media, which is a time-consuming and laborious method. The recently developed chromogenic media could be more rapid and specific than classical culture media. However, the newly developed molecular-based technology can detect microbial populations with greater rapidity and sensitivity than the classical method involving culture media and chromogenic media. This molecular-based technology could provide various options for monitoring the characterization of different states of bacteria and cells. Thus, it could help upgrade the processing system of the dairy industry so as to maintain the safety and quality of dairy foods. Among the various newly developed molecular-based technologies, flow cytometry can potentially be used for monitoring microbiological populations in the dairy industry if official international standards are available for this purpose. When omics technology would have biomarker identification, it could be regarded as the rapid and sensitive analytical methods. Methods based on PCR, which has become a basic technique in microbiological research, can be developed and validated as alternative methods for quantification of dairy microorganisms. This review discusses methods for monitoring microbiological populations in dairy foods and the limitations of these studies, as well as the need for further research on such methods in the dairy industry.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.185-192
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• 1999

Four different parts of Hovenia dulcis $T_{HUNB}$; fruit, bark, vessel area, fruit coat were extracted with water and ethanol. The ethanol extracts of bark, fruit coat and fruit were fractionized into diethyl ether, chloroform and aqueous partitions. Ethanol extract of fruit coat increased the activity of cathepsin B up to 55 %, which can enhance the alcohol dehydration in the liver. The ethanol extracts was more effective than water extracts against the growth of Hep3B, MCF7. The ethanol extracts of bark (0.5mg/ml) inhibited 90% the growth of MCF7. Each extracts and fractions (0.5mg/ml) did not show considerable cytotoxicity on HEL299. In overall, most of the fractions had similar effects to ethanol extracts; however, diethyl ether and chloroform fractions had higher bioactivity than ethanol extracts, but aqueous fraction.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.83-90
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• 2011

This study was performed to investigate the effects of ramie (Boehmeria nivea) leaf powder on improvements in lipid metabolism in serum, liver and adipose tissue, and the anti-obesity effect in rats fed a high fat/high cholesterol diet for 4 weeks to induce a hyperlipidemic and obese model rat. Male Sprague-Dawley rats weighting 210 g were divided into four groups; a normal diet group (N), a high fat/high cholesterol diet group (HFC), a high fat/high cholesterol diet with 5% ramie leaf powder group (HFC-RL), and a high fat/high cholesterol diet with 10% ramie leaf powder group (HFC-RH). The body weight gain increased with a high fat/high cholesterol diet, but gradually decreased in the ramie leaf powder fed groups compared with the HFC group. The liver index in the HFC group was highest among the four groups, although the difference was not significant compared with the ramie leaf powder fed groups. The adipose tissues weight in the HFC group was heavier than that of the N group, whereas those of groups fed ramie leaf powder decreased gradually. Alkaline phosphatase activity was not different between the HFC groups, but serum alkaline aminotransferase and lactate dehydrogenase activities decreased significantly after ramie leaf powder feeding. Levels of serum triglyceride, total cholesterol, LDL-cholesterol, atherogenic index and cardiac risk factors tended to decrease in the ramie leaf powder fed groups compared with the HFC group, whereas serum HDL-cholesterol level decreased in the HFC group and markedly increased in the ramie leaf powder fed groups. Levels of triglyceride and total cholesterol in the liver were significantly lower in the ramie leaf powder fed groups than in the HFC group. Levels of triglyceride and total cholesterol in adipose tissues were also lower in the ramie leaves powder fed groups than in the HFC group. The activities of heparinreleasable lipoprotein lipase (LPL) and total-extractable LPL in adipose tissues increased in the HFC group compared to that of the N group, but those of the ramie leaf powder fed groups decreased significantly. These results suggest that ramie leaf powder may improve lipid metabolism in serum, liver and adipose tissue and potentially reduce lipid storage.

• Journal of Life Science
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• v.22 no.12
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• pp.1672-1679
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• 2012

The effect of high stocking density (HSD) on the expression of stress and lipid metabolism associated genes in the liver of broiler chickens was examined by chicken genome array analysis. The chickens in a control group were randomly assigned to a $495cm^2/bird$ stocking density, whereas the chickens in a HSD group were arranged in a $245cm^2/bird$ stocking density with feeding ad libitum for 35 days. The chickens assigned to the HSD group had a significantly lower body weight, weight gain, and feed intake compared with those of the control group (p<0.05). The mortality of chickens was higher in the HSD group than in the control group. The microarray analysis indicated up-regulation of stress associated genes such as HMGCR, $HSP90{\alpha}$, HSPA5 (GRP78/Bip), DNAJC3 and ATF4, and down-regulation of interferon-${\gamma}$ and PDCD4 genes. The endoplasmic reticulum stress associated genes, HSPA5 (GRP78/Bip), DNAJC3 and ATF4, were highly expressed in the HSD group. The genes, ACSL5, TMEM195 and ELOVL6, involved in fatty acid synthesis, were elevated in the HSD group. The genes, ACAA1, ACOX1, EHHADH, LOC423347 and CPT1A, related to fatty acid oxidation, were also activated in the HSD group. These results suggest that a HSD rearing system stimulates the genes associated with fatty acid synthesis as well as fatty acid oxidation in the liver of broiler chickens.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.684-693
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• 2014

Abiotic stress conditions such as cold, drought, and salinity trigger physiological and morphological changes and yield loss in plants. Hence, plants adapt to adverse environments by developing tolerance through complex regulation of genes related to various metabolic processes. This study was conducted to construct a coexpression network for multidirectional analysis of salt-stress response genes in Brassica rapa (Chinese cabbage). To construct the coexpression network, we collected KBGP-24K microarray data from the B. rapa EST and microarray database (BrEMD) and performed time-based expression analyses of B. rapa plants. The constructed coexpression network model showed 1,853 nodes, 5,740 edges, and 142 connected components (correlation coefficient > 0.85). On the basis of the significantly expressed genes in the network, we concluded that the development of salt tolerance is closely related to the activation of $Na^+$ transport by reactive oxygen species signaling and the accumulation of proline in Chinese cabbage.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.172-178
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• 2003

This study was conducted to assess the physiological tolerance of native tree species for successful restoration and revegetation of abandoned coal-mine spoils. Study sites were two coal-mine spoils (Sododong and Ssarijae) in Taebaek, Kangwon Province, Korea. Five individuals of Betula costata and of B. schmidtii were analyzed for malondialdehyde (MDA) and hydrogen peroxide ($H_2O$$_2$) content, nitrate reductase (NR) and superoxide dismutase (SOD) activity, and for carbohydrate concentration in the leaves. Trees in the abandoned coal-mine spoils were influenced by deficiencies expressed by MDA and $H_2O$$_2$ content in the leaves of two species being higher at the coal-mine spoils than in the surrounding forest. Low NR activity indirectly represented nitrogen deficiency in the soil of the coal-mine spoils; an unmanageable SOD activity implied that tolerant functions didn't net against a certain stress of the coal-mine spoils. Decreased glucose and increased starch concentration especially showed the inhibition of the carbohydrate metabolism by inadequate factors. Consequently, low nitrogen content in the real-mine soils might increase damage in trees as a result of inhibiting the expression of tolerance mechanisms against stress. Therefore, trees in coal-mine spoils need ample nitrogen to use as a metabolic energy source in order to prevent damage and increase tolerance against stress.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.173-178
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• 2001

This study was performed to know the hypocholesterolemic effect of depolymerized alginate obtained by hydrolysis of alginate through a heating process at $121^{\circ}C$. The changes of total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and phospholipid levels in serum, as well as the atherogenic index were elucidated in rats for 35 days. In order to evaluate single-dose toxicity of HAG-50 in rats via oral routes, induction any mortalities and abnormal signs in clinical finding, body weight, gross findings and histopathological finding, and estimation of $LD_{50}$ were elucidated. Total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and phospholipid levels in the serum significantly decreased and resulted in the decrease of atherogenic index in rats fed diets containing $5\%\;and\;10\%$ HAG-50 (p<0.01). HAG-50 did not induce any mortalities and abnormal signs in clinical findings, body weights, gross findings and histopathological findings in single-dose toxicity test via oral routes of rats, after which it was impossible to estimate $LD_{50}$ values.