• Molecules and Cells
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• 제24권3호
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• pp.441-444
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• 2007

Despite the importance of cell fate decisions regulated by epigenetic programming, no experimental model has been available to study transdifferentiation from myoblasts to smooth muscle cells. In the present study, we show that myoblast cells can be induced to transdifferentiate into smooth muscle cells by modulating their epigenetic programming. The DNA methylation inhibitor, zubularine, induced the morphological transformation of C2C12 myoblasts into smooth muscle cells accompanied by de novo synthesis of smooth muscle markers such as smooth muscle ${\alpha}$-actin and transgelin. Furthermore, an increase of p21 and decrease of cyclinD1 mRNA were observed following zebularine treatment, pointing to inhibition of cell cycle progression. This system may provide a useful model for studying the early stages of smooth muscle cell differentiation.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1662-1668
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• 2011

Steric and electronic parameters of 4'-substituents play significant roles in steering the conformation of nucleoside analogues. In order to investigate the relationship of 4'-substituent with antiviral enhancement, novel 4'-phenyl-5'-norcarbocyclic adenosine phosphonic acid analogues were racemically synthesized via de novo acyclic stereoselective route from propionaldehyde 5. The phenyl substituted cyclopentenols 15a and 15b as key intermediates were successfully constructed via reiterative carbonyl addition of Grignard reagents and ring-closing metathesis of corresponding divinyl 14. The synthesized nucleoside phosphonic acids analogues 19, 20, 21, and 23 were subjected to antiviral screening against HIV-1.

• KSBB Journal
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• 제29권2호
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• pp.81-86
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• 2014

Lactobacilli, the dominant species of microorganisms in the vaginal flora of healthy women, play important roles to prevent bacterial vaginosis and other sexually transmitted diseases. In this study, we carried out studies on stress adaptation prior to various stress treatment. We found that heat or salt adapted KLB46 showed higher cell viability than non adapted upon heat stress at $60^{\circ}C$ for 20 min. When chloramphenicol was added during the adaptation process, heat tolerance was abolished. This result suggested that de novo protein synthesis was essential during adaptation.

• Asian-Australasian Journal of Animal Sciences
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• 제11권3호
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• pp.209-216
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• 1998

The paper presented here is aimed at increasing knowledge on purine metabolism in ruminants and hence the quantification of microbial cells entering the small intestine from urinaη excretion of purine derivatives. Nucleic acid metabolisms of micro-organisms in the rumen, digestion and absorption of nucleic acids entering the intestines, metabolisms of absorbed and endogenous purines involving de novo synthesis of nucleic acids in the ruminants host, and the relationship between absorbed and excreted purines are reviewed. Principal concerns about an amount of purine derivatives excreted in urine in relation to a change in purine-N: total-N ratios in rumen microbes that leave the rumen are discussed. The use of urinary excretion of purine derivatives as an indicator of the amount of microbial biomass leaving the rumen has to be done with some caution since it may be impossible to get a representative sample of microbes entering the intestine and thus yield estimates are relative rather than absolute.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3348-3352
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• 2010

Novel 4'-ethyl-5'-norcarbocyclic adenosine phosphonic acid analogues were synthesized from propionaldehyde 5 through a de novo acyclic synthetic route using reiterative Grignard additions and ring-closing metathesis (RCM) as key reactions. The synthesized nucleoside phosphonic acids analogues 17, 18, 19, and 21 were subjected to antiviral screening against human immunodeficiency virus.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.69.1-69.1
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• 2003

Fumonisins are a family of mycotoxins produced from Fusarium verticillioides. Most of fumonisin B1 (FB1) toxicities can be explained by its ability to alter sphingolipid metabolism by inhibiting ceramide synthase. At least, the elevation in dihydrosphingosine (DHS) mediates the earliest toxicity of FB1. Some tissues such as kidney and liver, may be most affected by FB1 because they shows high rates of de novo sphingolipid synthesis. Recent review on FB1 toxicity by A.H. Merrill Jr. et al. suggested the possible role of dihydrosphingosine 1-phosphate (dihydroS1P), which sometimes elevated in cell- or tissue specific manners. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.213.1-213.1
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• 2003

Sphingolipids and their metabolites are highly bioactive molecules that affect various cellular functions including differentiation, cellular senescence, apoptosis, and proliferation when added exogenously, or elevated intracellularly by turnover of complex sphingolipids or synthesis from de novo pathway. We are investigating the relationship of sphingolipids cycle in apoptosis early events. A new column liquid chromatography- tandem mass spectrometry (LC/MS/MS) in combination with multiple reaction monitoring (MRM) method was developed for the rapid, simultaneous and quantitative determination of unambiguous detecting sphingolipids in cells. (omitted)

• Nutrition Research and Practice
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• 제16권sup1호
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• pp.126-133
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• 2022

Choline is a water-soluble organic compound that is important for the normal functioning of the body. It is an essential dietary component as de novo synthesis by the human body is insufficient. Since the United States set the Adequate Intakes (AIs) for total choline as dietary reference values in 1998, Australia, China, and the European Union have also established the choline AIs. Although choline is clearly essential to life, the 2020 Dietary Reference Intakes for Koreans (KDRIs) has not established the values because very few studies have been done on choline intake in Koreans. Since choline intake levels differ by race and country, human studies on Koreans are essential to set KDRIs. Therefore, the present study was undertaken to provide basic data for developing choline KDRIs in the future by analyzing data on choline intake in Koreans to date and reference values of choline intake and dietary choline intake status by country and race.

• 한국발생생물학회지:발생과생식
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• 제20권2호
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• pp.127-133
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• 2016

Purine metabolism is known factor for nuclear maturation of oocytes through both follicle cells and oocyte itself. However, it is largely unknown the roles of purine metabolism in the oocyte competence for fertilization and early development. In this study, the effects of adenosine in oocyte competence for development were examined using adenosine and its synthetic inhibitors. Adenosine treatment from GV intact stage for 18 hr (fGV) caused of decrease the fertilization rate but of increase the cleavage rate compared from the other stage treatment groups. Hadacidin did not effect on fertilization rate but increased cleavage rate without stage specificity. Adenosine did not block the effects of hadacidin with the exception of fGV group. Inhibition of purine synthetic pathways the fertilization rate was decreased in the fGV and fGVB groups but increased in the fMII group. Exogenous adenosine caused of decrease fertilization rate in the fGVB group but increase in the fMII group. Cleavage rate was dramatically increased in the adenosine treatment with synthetic inhibitors. It means that the metabolism of purine has stage specific effects on fertilization and cleavage. Exogenous adenosine had only can improve oocyte developmental competence when it treated at GV intact stage. On the other hand, endogenous synthesis in all maturation stage cause of increase the cleavage rate without effects on fertilization. These data suggest that adenosine at GV stage as a paracrine fashion and inhibitions of endogenous adenosine in all stage improve oocyte developmental competence.

• 한국식품영양과학회지
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• 제21권5호
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• pp.580-593
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• 1992

Cholesterol have many essential functions as a component of cellular and subcellular membranes, metabolic precursor of bile acids and steroid hormones, and obligatory part of the metabolic systems involved in DNA synthesis and cell division. These essential funtions demand a continuous and appropriate supply of cholesterol to the tissues. Body cholesterol pool is maintained by the balance of acquirement from diets, de novo synthesis, and excretion either as bile acids or neutral steroids. In these metabolic process, cholesterol biosynthesis is controlled by the change in the activity of 3-hydroxy-3methylglutaryl coenzyme A (HMG-CoA) reductase. Under most physiological or nutritional situations, the activity of this enzyme is adroitly regulated to maintain tissue cholesterol balance. Excess cholesterol accumulation in the cells induces the decrease in the number of LDL-receptor, followed by the increase in the level of serum LDL-cholesterol. Increase in the level of serum cholesterol appears to be an important determinant for the incidence of the coronary heart disease. Dietary intervention may be helpful in alleviating an increase in the level of serum cholesterol or body cholesterol pool.