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Optimization of Large - Scale Chromatography of Proteins
Janson, Jan Christer 한국화학공학회 2001 Korean Journal of Chemical Engineering Vol.18 No.2
Protein chromatography is a very complex process based on a combination of thermodynamic, kinetic and mass transport phenomena. By virtue of their complicated and delicate surface structures, the behaviour of proteins on various chromatographic media is not easy to predict. Together with the fact that the majority of the chromatographic media for proteins available today are not very well characterized with regard to their detailed chemical and physical surface structures, protein chromatography still has to be regarded as a predominantly empirical science. I.e. the optimization of separation conditions can only be performed by experiments in the laboratory. The scaling-up is then accomplished primarily by increasing the column diameter. This has been shown work well for column diameters up to at least 1,400 mm. The paper will also deal with the characteristics of the most important protein separation media, silica based, polystyrene based and agarose based, and with how to best optimize the conditions for column productivity, both for adsorption types of chromatography and for gel filtration.
Shams Y-Hassan,Christer Sylvén 대한내과학회 2013 The Korean Journal of Internal Medicine Vol.28 No.2
Electrocardiographic (ECG) artefacts may closely simulate both supraventricular and ventricular tachycardias. We describe a case initially diagnosed as rapid atrial fibrillation, based on 12-lead surface ECG (especially the limb leads) and monitor tracing. The arrhythmia was resistant to beta blockers. Because of the at times apparently regular rhythm, an esophageal ECG recording was performed, and adenosine was administered. When the presumed atrial fibrillation terminated after sodium pentothal was administered while preparing for electrical cardioversion, the oesophageal ECG recordings and the ECGs during adenosine administration were reviewed. An ECG artefact diagnosis was suspected, and then confirmed,during relapse of the “arrhythmia,” with simple palpation of the radial pulse and cardiac auscultation.
국내산 두 품종 블루베리의 영양성분 및 항산화 활성 비교
송효남,박명수,윤호식,박성진,Christer Hogstrand 한국식품저장유통학회 2014 한국식품저장유통학회지 Vol.21 No.6
The nutritional compositions and antioxidative activities of the Kimcheon lowbush and Pyungtaek highbush blueberries cultivated in South Korea were investigated. The approximate compositions, pH, and soluble-solid and mineral contents of P, Ca, Mg, Na, and Zn were determined. Both blueberry cultivars had mainly fructose and glucose as free sugars while disaccharides such as sucrose, maltose, and lactose were not detected in both. Oleic, linoleic, and linolenic fatty acids were the major fatty acids in both types of blueberries. The total of 16 free amino acids, including seven essential and nine non-essential amino acids, were higher in the Pyungtaek highbush blueberry. Among the amino acids, arginine was especially much higher in the Pyungtaek highbush blueberry. The anthocyanin, resveratrol, and polyphenol compounds, which are the important biologically active compounds in blueberries, were found. The anthocyanin contents of the Kimcheon lowbush and Pyungtaek highbush blueberries were 22.0 and 18.1 mg/100 g, respectively; the resveratrol contents by HPLC, 0.12 and 0.11 mg/100 g; and the total polyphenol contents, 141.3 and 138.4 mg/100 g. The electron-donating ability determined based on the DPPH radical scavenging activity was increased in a concentration-dependent manner, and it was higher than that of the Pyungtaek highbush blueberries, which implies that it is highly correlated with the higher amounts of total polyphenol, anthocyanin, and resveratrol in it. In conclusion, the two varieties of Korean blueberries can be suggested as potential sources of high-value-added functional foods.
Cytotoxicity of nitric oxide is alleviated by zinc-mediated expression of antioxidant genes.
Chung, Mi Ja,Hogstrand, Christer,Lee, Sung-Joon The Society 2006 Experimental biology and medicine Vol.231 No.9
<P>Metallothioneins (MTs) are small, cysteine-rich zinc binding proteins that are powerful antioxidants. In this study, we investigated the interaction between zinc, MTs, and other components of the antioxidant defense system in HepG2 cells. Cells were preincubated with zinc and then exposed to sodium nitroprusside (SNP), a nitric oxide (NO) donor. Both zinc pretreatment and SNP exposure separately induced transcription of MT genes (MT1A, MT2A, MT1E, MT1X), as measured using real time-polymerase chain reaction (PCR) after reverse transcription (RT). Pretreatment of HepG2 cells with zinc sulfate (ZnSO4) followed by SNP exposure caused MT and glucose-6-phosphate dehydrogenase (G6PD) mRNA levels to increase more than in cells only exposed to SNP. However, when cells were incubated with N,N,N',N'-tetrakis(2-pyridylmethyl)ethyl-enediamine (TPEN), a membrane-permeant Zn2+ chelator, the stimulation of MT transcription by SNP was blocked, suggesting that SNP-induced upregulation of these genes is zinc-dependent. Human glutathione-S-transferase (hGSTA1) and G6PD mRNA levels in the cells treated with 5 microM TPEN decreased. Additionally, the induction of MT by SNP after zinc pretreatment appears to be mediated by metal-activated transcription factor-1 (MTF-1), which is induced by labile zinc in the cytosol. SNP cytotoxicity was inhibited by preincubation with zinc. Taken together, these results suggest that NO plays an important role in regulation of cellular zinc homeostasis and that NO-mediated release of protein-bound Zn2+ may be an important signal in antioxidant defense.</P>