• Journal of Nutrition and Health
• /
• v.34 no.5
• /
• pp.547-553
• /
• 2001

This study was designed to observe the change of body composition and nutrient metabolites and the excretion of minerals during complete fasting for 10 days in thirty women. Average loss of body weight was 7.98kg and body fat was gradually reduced after 9 days fasting, but the loss of lean body mass was reduced after 7 days fasting. Serum glucose level was sustained at constant level, but serum levels of blood urea nitrogen, free acid and $\beta$-hydroxybutyrate were significantly increased during fasting but decreased after re-feeding. Urinary excretions of 3-methylhistidine, total creatinine, and urea were high in the beginning of fasting but gradually decreased. Serum level of parathyroid hormone was significantly reduced by fasting but regained after re-feeding. Serum level of minerals was at the constant level throughout the experimental period. The urinary excretion of minerals(Ca, K, Mg, P) was significantly increased in the early stage of fasting and then reduced from 7 days, but the excretion of Zn was continuously increased until the late stage of fasting. These results showed that amino acid fatty acid released from the breakdown of muscle protein and body fat, respectively, were utilized for energy during fasting. Body weight and BMI were reduced because of the increased muscle protein breakdown and body water excretion during early stage of fasting, but the significant body fat loss was after 9 days fasting. Therefore, it could be suggested to fast for longer than 10 days if the reduction of body fat was planned by fasting, and recommed to exercise and ingest more vitamins and minerals to replace the excreted minerals during fasting. (Korean J Nutrition 34(5) : 547~553, 2001)

• Nutrition Research and Practice
• /
• v.18 no.1
• /
• pp.46-61
• /
• 2024

BACKGROUND/OBJECTIVES: An increasing life expectancy in society has burdened healthcare systems substantially because of the rising prevalence of age-related metabolic diseases. This study compared the effects of animal protein hydrolysate (APH) and casein on metabolic diseases using aged mice. MATERIALS/METHODS: Eight-week-old and 50-week-old C57BL/6J mice were used as the non-aged (YC group) and aged controls (NC group), respectively. The aged mice were divided randomly into 3 groups (NC, low-APH [LP], and high-APH [HP] and fed each experimental diet for 12 weeks. In the LP and HP groups, casein in the AIN-93G diet was substituted with 16 kcal% and 24 kcal% APH, respectively. The mice were sacrificed when they were 63-week-old, and plasma and hepatic lipid, white adipose tissue weight, hepatic glucose, lipid, and antioxidant enzyme activities, immunohistochemistry staining, and mRNA expression related to the glucose metabolism on liver and muscle were analyzed. RESULTS: Supplementation of APH in aging mice resulted in a significant decrease in visceral fat (epididymal, perirenal, retroperitoneal, and mesenteric fat) compared to the negative control (NC) group. The intraperitoneal glucose tolerance test and area under the curve analysis revealed insulin resistance in the NC group, which was alleviated by APH supplementation. APH supplementation reduced hepatic gluconeogenesis and increased glucose utilization in the liver and muscle. Furthermore, APH supplementation improved hepatic steatosis by reducing the hepatic fatty acid and phosphatidate phosphatase activity while increasing the hepatic carnitine palmitoyltransferase activity. Furthermore, in the APH supplementation groups, the red blood cell (RBC) thiobarbituric acid reactive substances and hepatic H₂O₂ levels decreased, and the RBC glutathione, hepatic catalase, and glutathione peroxidase activities increased. CONCLUSIONS: APH supplementation reduced visceral fat accumulation and alleviated obesity-related metabolic diseases, including insulin resistance and hepatic steatosis, in aged mice. Therefore, high-quality animal protein APH that reduces the molecular weight and enhances the protein digestibility-corrected amino acid score has potential as a dietary supplement for healthy aging.

• BMB Reports
• /
• v.38 no.6
• /
• pp.650-660
• /
• 2005

Proteins accumulated in dry, stratified Arabidopsis seeds or young seedlings, totaled 1100 to 1300 depending on the time of sampling, were analyzed by using immobilized pH gradient 2-DE gel electrophoresis. The molecular identities of 437 polypeptides, encoded by 355 independent genes, were determined by MALDI-TOF or TOF-TOF mass spectrometry. In the sum, 293 were present at all stages and 95 were accumulated during the time of radicle protrusion while another 18 appeared in later stages. Further analysis showed that 226 of the identified polypeptides could be located in different metabolic pathways. Proteins involved in carbohydrate, energy and amino acid metabolism constituted to about 1/4, and those involved in metabolism of vitamins and cofactors constituted for about 3% of the total signal intensity in gels prepared from 72 h seedlings. Enzymes related to genetic information processing increased very quickly during early imbibition and reached highest level around 30 h of germination.

• The Korean Journal of Nuclear Medicine
• /
• v.38 no.2
• /
• pp.198-204
• /
• 2004

Tumor cell proliferation is considered to be a useful prognostic indicator of tumor aggressiveness and tumor response to therapy but in vitro measurement of individual proliferation is complex and tedious work. PET imaging provides a noninvasive approach to measure tumor growth rate in situ. Early approaches have used $^{18}F$-FDG or methionine to monitor proliferation status. These 2 tracers detect changes in glucose and amino acid metabolism, respectively, and therefore provide only an indirect measure of proliferation status. More recent studies have focused on DNA synthesis itself as a marker of cell proliferation. Cell lines and tissues with a high proliferation rate require high rates of DNA synthesis. $[^{11}C]Thymidine$ was the first radiotracer for noninvasive imaging of tumor proliferation. The short half-life of $^{11}C$ and rapid metabolism of $[^{11}C]Thymidine$ in vivo make the radiotracer less suitable for routing use. Halogenated thymidine analogs such as 5-iodo-2-deoxyuridine (IUdR) can be successfully used as cell proliferation markers for in vitro studies because these compounds are rapidly incorporated into newly synthesized DNA. IUdR has been evaluated as a potential in vivo tracer in nuclear medicing but the image qualify and the calculation of proliferation rates are impaired by its rapid in vivo degradation. Hence, the thymidine analog $3'-deoxy-3'-^{18}F-fluorothymidine$ (FLT) was recently introduced as a stable proliferation marker with a suitable nuclide half-life and stable in vivo. $[^{18}F]FLT$ is phosphorylated to 3-fluorothymidine monophosphate by thymidine kinase 1 and reflects thymidine kinase 1 activity in proliferating cell. $[^{18}F]FLT$ PET is feasible in clincal use and well correlates with cellular proliferation. Choline is a precursor for the biosynthesis of phospholipids (in particular, phosphatidylcholine), which is the essential component of all eukaryotic cell membranes and $[^{11}C]choline$, which is a new marker for cellular proliferation.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2007.04a
• /
• pp.65-73
• /
• 2007

The objective of this study is to understand how regulatory mechanisms respond to sugar status for more efficient carbon utilization and source-sink regulation in plants. So, we need to identify and characterize many components of sugar-response pathways for a better understanding of sugar responses. For this end, genes responding change of sugar status were screened using Arabidpsis cDNA arrays, and confirmed thirty-six genes to be regulated by sucrose supply in detached leaves by RNA blot analysis. Eleven of them encoding proteins for amino acid metabolism and carbohydrate metabolism were repressed by sugars. The remaining genes induced by sugar supply were for protein synthesis including ribosomal proteins and elongation factors. Among them, I focused on three hydrolase genes encoding putative $\beta$-galactosidase, $\beta$-xylosidase, and $\beta$-glucosidase that were transcriptionally induced in sugar starvation. Homology search indicated that these enzymes were involved in hydrolysis of cell wall polysaccharides. In addition to my results, recent transcriptome analysis suggested multiple genes for cell wall degradation were induced by sugar starvation. Thus, I hypothesized that enzyme for cell wall degradation were synthesized and secreted to hydrolyze cell wall polysaccharides producing carbon source under sugar-starved conditions. In fact, the enzymatic activities of these three enzymes increased in culture medium of Arabidopsis suspension cells under sugar starvation. The $\beta$-galactosidase encoded by At5g56870 was identified as a secretory protein in culture medium of suspension cells by mass spectrometry analysis. This protein was specifically detected under sugar-starved condition with a specific antibody. Induction of these genes was repressed in suspension cells grown with galactose, xylose and glucose as well as with sucrose. In planta, expression of the genes and protein accumulation were detected when photosynthesis was inhibited. Glycosyl hydrolase activity against galactan also increased during sugar starvation. Further, contents of cell wall polysaccharides especially pectin and hemicellulose were markedly decreased associating with sugar starvation in detached leaves. The amount of monosaccharide in pectin and hemicellulose in detached leaves decreased in response to sugar starvation. These results supported my idea that cell wall has one of function to supply carbon source in addition to determination of cell shape and physical support of plant bodies.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.245-245
• /
• 2017

Heavy metal pollution of agricultural soils affects land productivity and has impact on the quality of surrounding ecosystem. Soil microbial community parameters are used as reliable indices for assessing quality of agricultural lands under metal stress. This study investigated bacterial community structure of polluted and undisturbed paddy soils to elucidate soil factors that are related to alteration of bacterial communities under conditions of metal pollution. No obvious differences in the richness or diversity of bacterial communities were observed between samples from polluted and control areas. The bacterial communities of three locations were distinct from one another, and each location possessed distinctive set of bacterial phylotypes. The abundances of several phyla and genera differed significantly between study locations. Variation of bacterial community was mostly related to soil general properties at phylum level while at finer taxonomic levels concentrations of arsenic and lead were significant factors. According to results of bacterial community functional prediction, the soil bacterial communities of metal polluted locations were characterized by more abundant DNA replication and repair, translation, transcription and nucleotide metabolism pathway enzymes while amino acid and lipid metabolism as well as xenobiotic biodegradation potential was reduced.Our results suggest that the soil microbial communities had adapted to the elevated metal concentrations in the polluted soils as evidenced by changes in relative abundances of particular groups of microorganisms at different taxonomic resolution levels, and by altered functional potential of the microbial communities.

• Asian-Australasian Journal of Animal Sciences
• /
• v.11 no.6
• /
• pp.732-738
• /
• 1998

Three crossbred gilts weighing $61{\pm}2kg$ ($mean{\pm}SD$) and three gilts weighing $52{\pm}3kg $ on the day before the first treatment began (d -1) were used for each of two experiments (Exp. 1 and Exp. 2), respectively. In Exp. 1, all pigs were fed the experimental diet (CP 19%) from d -7 to the end of study (d 21) to verify that nitrogen retention is constant during the 21 -d period. In Exp. 2, pigs were fed the control diet (CP 15.5 %) from d -7 to d 8 and then the low-lysine diet from d 9 to d 16 in order to determine how rapidly dietary changes in amino acid composition results in a new equilibrium for nitrogen metabolism. The amount of urine nitrogen loss was not different over 21 days (p > 0.10). Rates of nitrogen retention were not different among pigs (p > 0.10) nor over time (p > 0.10). Average nitrogen retention during the period was 1.00 g/kg $BW^{0.75}$ per day. The apparent biological value was 41%, which did not change over the 3-week period (p > 0.10). The overall efficiency of nitrogen use for nitrogen retention was 35% (Exp. 1). The amount of nitrogen loss in urine and the efficiency of nitrogen utilization for nitrogen gain reached a new equilibrium within 2 to 3 d after the diet was changed. The low-lysine diet resulted in a 20% increase of nitrogen loss in urine (p < 0.001) and a 9% decline in efficiency of nitrogen use for nitrogen retention (p < 0.001). Nitrogen retention while the pigs were fed the control diet was also higher than the retention when pigs were fed the low lysine diet (p < 0.001). The efficiency of nitrogen use for nitrogen retention in pigs fed the control diet was 57% (Exp. 2), which was higher (p < 0.001) than that from pigs fed the low-lysine diets (52%).

• Journal of Nutrition and Health
• /
• v.1 no.3_4
• /
• pp.197-200
• /
• 1968

Using the $Methionine-2-C^{14}$, the metabolism of methionine to the experimental rats on rice diet was studied comparing with that to the rats on stock diet in this paper. The National Institute of Health strain of weaning albino rats were housed into the individual cages deviding into 2 groups, the rice diet (RD) group and the stock diet (SD) group, and fed on rice diet and stock diet respectively for 10 weeks. On the day of experiment, the rats were parenterally administered. the $methionine-2-C^{14}$ solution after fasting over night. And then the rats were sacrificed by ether anesthesia by time being of one, three, six, and twelve hours each and the organs, pituitary gland, pancreas, spleen, liver, and kidney, were taken out for the determinations of radioactivities. And also the excretion of radioactivities through urine were determined by time being. The radioactivities were determined by Autoscaler SC-51 using the planchets. The results of radioactivities of urine excretion were shown at table 3 and the results of radioactivities distibutions in the organs by time being after parenteral administration of $methionine-2-C^{14}$ were shown table 4 in the original paper. According to the results, the following are summarized; 1. The growth experiment result of rats on. rice diet and stock diet were same as shown by the previous workers indicating significant growth inhibition at the rice diet group. 2. Due to the result of radioactivity excretion through urine after administration of $methionine-2-C^{14}$, it might he considered that methionine in the rice diet seems to be limited. However, it seems to be not 주 mostly limited. 3. And due to the results of radioactivity distribution in the organs by time being, the radioactivity in the liver tissue showed appearently higher readings at this methionine study compared with the results at the lysine study shown by HAW and his co-worker. This might be interpreted, though it is not clear, that liver might require methionine as a deficient amino acid at the tissue because methionine is limited at the rice diet.

• Journal of Oral Medicine and Pain
• /
• v.26 no.4
• /
• pp.319-329
• /
• 2001

Endothelin-1 (ET-1) is a recently discovered potent vasoconstrictive peptide. It was first identified in vascular endothelial cells. ET-1 is a 21-amino acid peptide and elicits systemic effects such as stimulation of the production of atrial natriuretic peptide and release of aldosterone and corticosterone. In this study, to examine the role of ET-1 in the bone metabolism, effect of ET-1 on the proliferation and activity of osteoblastic cells was studied using HOS cells as osteoblast model. ET-1 dose-dependently increased the cell proliferation as determined by cell counting and MTT reduction assay after 48hr treatment. Alkaline phosphatase activity was inhibited by ET-1 and showed significant inhibition by 50 and 100 nM ET-1. ET-1 increased NBT reduction by HOS cells dose-dependently showing that ET-1 may increase the superoxide production by osteoblasts. Nitrite concentration in the media of HOS cell culture without cytokine stimulation was negligible and unaffected by ET-1 after 48hr treatment. Finally, after collection and concentration of conditioned media, gelatinase activity produced by HOS cells was determined by zymography. HOS cells can produce and secrete the gelatinase (gelatinase A type as determined by molecular weight of about 65,000) into culture media, however, ET-1 had no effect on the gelatinase activity. These findings suggest that ET-1 may have diverse effects on the proliferation and differentiation of osteoblasts, therefore, it may play an important role in bone metabolism.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2017.05a
• /
• pp.78-78
• /
• 2017

Pure Titanium and alloy have been widely used in dental implants and orthopedics due to their excellent mechanical properties, biocompatibility and corrosion resistance. However, due to the biologically inactive nature of Ti metal implants, it cannot bind to the living bone immediately after transplantation into the body. In order to improve the bone bonding ability of titanium implants, many attempts have been made to alter the structure, composition and chemical properties of titanium surfaces, including the deposition of bioactive coatings. The PEO method has the advantages of short experiment time and low cost. These advantages have attracted attention recently. Recently, many metal ions such as silicon, magnesium, zinc, strontium, and manganese have received attention in this field due to their impact on bone regeneration. Silicon (Si) in particular has been found to be essential for normal bone and cartilage growth and development. Zinc (Zn) plays very important roles in bone formation and immune system regulation and promotes bone metabolism and growth. Manganese (Mn) is an essential trace metal found in all tissues and is required for normal amino acid, lipid, protein and carbohydrate metabolism. The objective of this work was research on the corrosion behavior of Si, Zn and Mn-doped hydroxyapatite on the PEO-treated surface. Anodized alloys was prepared at 270V~300V voltage in the solution containig Zn, Si, and Mn ions. Ion release test was carried out using potentidynamic and AC impedance method in 0.9% NaCl solution. The surface characteristics of PEO treated Ti-6Al-4V alloy were investigated using XRD, FE-SEM, AFM and EDS.