A New Protein of ${\alpha}$-Amylase Activity from Lactococcus lactis

Wasko, Adam,Polak-Berecka, Magdalena,Targonski, Zdzislaw The Korean Society for Microbiology and Biotechnol 2010 Journal of microbiology and biotechnology Vol.20 No.9

An extracellular ${\alpha}$-amylase from Lactococcus lactis IBB500 was purified and characterized. The optimum conditions for the enzyme activity were a pH of 4.5, temperature of $35^{\circ}C$, and enzyme molecular mass of 121 kDa. The genome analysis and a plasmid curing experiment indicated that $amy^+$ genes were located in a plasmid of 30 kb. An analysis of the phylogenetic relationships strongly supported a hypothesis of horizontal gene transfer. A strong homology was found for the peptides with the sequence of ${\alpha}$-amylases from Ralstonia pikettii and Ralstonia solanacearum. The protein with ${\alpha}$-amylase activity purified in this study is the first one described for the Lactococcus lactis species, and this paper is the first report on a Lactococcus lactis strain belonging to the amylolytic lactic acid bacteria (ALAB).

A New Protein of a-Amylase Activity from Lactococcus Lactis

( Wasko Adam ),( Magdalena Polak Bereeka ),( Zdzislaw Targonski ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.9

Stochastic traffic assignment Models for Dynamic Route Guidance

이승재(Seungjae Lee),Martin Hazelton,John Polak 대한교통학회 1995 대한교통학회 학술대회지 Vol.28 No.-

尖端 交通 體系(Intelligent Transport Systems)의 중요한 要素인 尖端 交通 管理體系(Advanced Traffic Management Systems)의 성공 여부는 交通情報를 어떻게 提供하고 統制하는데 의존한다. 즉, 情報 提供 方式과 이에 대한 運轉者의 反應을 정확하게 把握하고 豫測하여야 ITS를 성공적으로 構築할 수 있다. 이 輪文에서는 動的 車輔길잡이 裝置의 效用性을 評價하기 위한 確率的 通行配定模型을 開發하는 것이다. 개발된 通行配定模型은 운전자의 動的行態調整(Dynamic Behavioural Adjustment)을 明白하게 確率 過程(Stochastic Process)으로 표현하여 기존의 模型에 비해 通行者들의 行態를 더욱 實際的으로 반영한다. 특히, 각 통행자들에게 K개의 最小經路時間을 提供해줌으로 인하여 통행자의 路線選擇에 대한 選擇福을 增加시켜 준다. 通行路線의 선택폭의 증가는 爭點으로 대두되는 問題(交通統制所에서는 車輔 길잡이 保有 운전자에게 體系最適(System Optimum)와 利用者最適(User Equilibrium)중 어떠한 原則하에 交通情報를 提供하여야 하는가)에 대한 解決 方案이다. 왜냐하면 만약 交通統制所에서 운전자에게 통행정보를 體系 最適을 하기 위해 情報를 提供하고자 하면, 길잡이 裝着 運轉者는 더 이상 제공된 정보를 따르지 않고 자기 스스로의 經驗에 의해 利用者 最適을 달성하고자 할 것이다. 이 論文의 目的은 이러한 복잡한 통행자의 路線選揮行爲를 반영하는 確率的 平衝 通行 配定 模型을 여러가지 統計技法을 導入하여 開發하는 것이다.

Finite element modelling of GFRP reinforced concrete beams

Joseph G. Stoner,Maria Anna Polak 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.25 No.4

This paper presents a discussion of the Finite Element Analysis (FEA) when applied for the analysis of concrete elements reinforced with glass fibre reinforced polymer (GFRP) bars. The purpose of such nonlinear FEA model development is to create a tool that can be used for numerical parametric studies which can be used to extend the existing (and limited) experiment database. The presented research focuses on the numerical analyses of concrete beams reinforced with GFRP longitudinal and shear reinforcements. FEA of concrete members reinforced with linear elastic brittle reinforcements (like GFRP) presents unique challenges when compared to the analysis of members reinforced with plastic (steel) reinforcements, which are discussed in the paper. Specifically, the behaviour and failure of GFRP reinforced members are strongly influenced by the compressive response of concrete and thus modelling of concrete behaviour is essential for proper analysis. FEA was performed using the commercial software ABAQUS. A damaged-plasticity model was utilized to simulate the concrete behaviour. The influence of tension, compression, dilatancy, mesh, and reinforcement modelling was studied to replicate experimental test data of beams previously tested at the University of Waterloo, Canada. Recommendations for the finite element modelling of beams reinforced with GFRP longitudinal and shear reinforcements are offered. The knowledge gained from this research allows for the development of a rational methodology for modelling GFRP reinforced concrete beams, which subsequently can be used for extensive parametric studies and the formation of informed recommendations to design standards.

Enhanced In Vitro Chondrogenic Differentiation of Murine Embryonic Stem Cells

Hwang, Yu-Shik,Bishop, Anne E.,Polak, Julia M.,Mantalaris, Athanasios Korean Society for Biotechnology and Bioengineerin 2007 Biotechnology and Bioprocess Engineering Vol.12 No.6

Current approaches have focused on deriving ESCs differentiation into chondrocytes from a cell source of spontaneously formed intact mesoderm in EB formation, resulting in limited yield. Our study aimed at upregulating chondrogenic differentiation of murine ESCs by enhancing mesoderm formation. Specifically, culture of mESCs with conditioned medium from a human hepatocarcinoma cell line resulted in a cell population with a gene expression pattern similar to that of primitive streak/nascent mesoderm, including up-regulation of brachyury, goosecoid, nodal, and cripto. From this cell population, reducing the embryoid body formation time resulted in enhancement of chondrogenic differentiation, as evidenced by larger Alcian blue-stained cartilage nodules, higher production of sulfated glycosaminoglycan matrix, the presence of well-organised type II collagen and type II collagen, aggrecan and sox-9 gene expression. In conclusion, we present here a new approach to the generation of chondrocytes from mESCs that enhances yields and, thus, could have widespread applications in cartilage tissue engineering.

Temperature Dependence of Creep Induced Anisotropy in Nanocrystalline Fe-Cu-Nb-Si-B Alloys

Giselher Herzer,Mie Marsilius,Christian Polak 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.10

Nanocrystallisation of Fe75Cu1Nb3Si8B13 under tensile stress results in a creep induced anisotropy which, at room temperature, is characterised by a magnetic easy axis along the stress axis. However,this magnetic easy ribbon axis becomes a magnetic hard ribbon axis when the measuring temperature T decreases below a compensation temperature T0 where the creep induced magnetic anisotropy vanishes. Accordingly, the magnetisation curve changes from a square loop for T > T0to a linear loop with low remanence forT < T0 . In the present case (8 at% Si), T0 is about –2 ◦C for the fully developed nanocrystalline state. Although slightly depending on the annealing conditions,T0 is primarily determined by the Si content and shifts towards higher temperatures by about 50◦C per at% Si with increasing Si concentration.

Innate Immune Response to Viral Infections in Primary Bronchial Epithelial Cells is Modified by the Atopic Status of Asthmatic Patients

Sylwia Moskwa,Wojciech Piotrowski,Jerzy Marczak,Małgorzata Pawełczyk,Anna Lewandowska-Polak,Marzanna Jarzębska,Małgorzata Brauncajs,Anna Głobińska,Paweł Górski,Nikolaos G. Papadopoulos,Michael R. Edwa 대한천식알레르기학회 2018 Allergy, Asthma & Immunology Research Vol.10 No.2

Purpose: In order to gain an insight into determinants of reported variability in immune responses to respiratory viruses in human bronchial epithelial cells (HBECs) from asthmatics, the responses of HBEC to viral infections were evaluated in HBECs from phenotypically heterogeneous groups of asthmatics and in healthy controls. Methods: HBECs were obtained during bronchoscopy from 10 patients with asthma (6 atopic and 4 non-atopic) and from healthy controls (n=9) and grown as undifferentiated cultures. HBECs were infected with parainfluenza virus (PIV)-3 (MOI 0.1) and rhinovirus (RV)-1B (MOI 0.1), or treated with medium alone. The cell supernatants were harvested at 8, 24, and 48 hours. IFN-α, CXCL10 (IP-10), and RANTES (CCL5) were analyzed by using Cytometric Bead Array (CBA), and interferon (IFN)-β and IFN-λ1 by ELISA. Gene expression of IFNs, chemokines, and IFN-regulatory factors (IRF-3 and IRF-7) was determined by using quantitative PCR. Results: PIV3 and RV1B infections increased IFN-λ1 mRNA expression in HBECs from asthmatics and healthy controls to a similar extent, and virus-induced IFN-λ1 expression correlated positively with IRF-7 expression. Following PIV3 infection, IP-10 protein release and mRNA expression were significantly higher in asthmatics compared to healthy controls (median 36.03-fold). No differences in the release or expression of RANTES, IFN-λ1 protein and mRNA, or IFN-α and IFN-β mRNA between asthmatics and healthy controls were observed. However, when asthmatics were divided according to their atopic status, HBECs from atopic asthmatics (n=6) generated significantly more IFN-λ1 protein and demonstrated higher IFN-α, IFN-β, and IRF-7 mRNA expressions in response to PIV3 compared to non-atopic asthmatics (n=4) and healthy controls (n=9). In response to RV1B infection, IFN-β mRNA expression was lower (12.39-fold at 24 hours and 19.37-fold at 48 hours) in non-atopic asthmatics compared to atopic asthmatics. Conclusions: The immune response of HBECs to virus infections may not be deficient in asthmatics, but seems to be modified by atopic status.

Suppression of experimental systemic lupus erythematosus(SLE) with specific anti-idiotypic antibody-saporin conjugate

Blank, M .,Manosroi, J .,Tomer, Y .,Manosroi, A .,Kopolovic, J .,Polak, S . Charcon,Shoenfeld, Y . 전남대학교 약품개발연구소 1995 약품개발연구지 Vol.3 No.1

The importance of the idiotypic network is represented in experimental SLE induced by active immunization of naive mice with an anti-DNA idiotype (Ab1) emulsified in adjuvant. The mice after 4 months of incubation generate Ab3 having anti-DNA activity. In addition, the mice develop other serological markers for SLE associated with clinical and histopathological manifestations characteristic of the disease. To confirm further the etiological role of the idiotype in this experimental model, the mice were treated with specific anti-idiotypic antibodies (anti-Id) which were also conjugated to a toxin-saporin (Immunotoxin (IT)). Pretreatment of hybridoma cell line producing the anti-anti-Id (anti-DNA=(Ab3) for 48 h with the anti-Id MoAb (Ab2) reduced the production of anti-DNA by 58%, while pretreatment with the IT resulted in 86% decrease in anti-DNA secretion (saporin alone had only 12% effect). The anti-Id MoAb had no effect on the production of immunoglobulin by an unrelated cell line. In vivo treatment of mice with experimental SLE led to a significant decrease in titres of serum autoantibodies, with diminished clinical manifestations. The result were more remarkable when the IT was employed. These suppressive effects were specific, since an anti-Id treatment of experimental anti-phospholipid syndrome was of no avail. The anti-Id effect was mediated via a reduction in specific anti-DNA antibody-forming cells, and lasted only while anti-Id injections were given. Discontinuation of the anti-Id injection was followed by a rise in titres of anti-DNA antibodies. No immunological escape of new anti-DNA Ids was noted. Our results point to the importance of pathogenic idiotypes in SLE and to the specific potential of implementing anti-idiotypic therapy, enhanced by the conjugation of the anti-Id to an immunotoxin, in particular one with low spontaneous toxicity.

Enhanced In Vitro Chondrogenic Differentiation of Murine Embryonic Stem Cells

Athanasios Mantalaris,황유식,Anne E. Bishop,Julia M. Polak 한국생물공학회 2007 Biotechnology and Bioprocess Engineering Vol.12 No.6

Current approaches have focused on deriving ESCs differentiation into chondrocytes from a cell source of spontaneously formed intact mesoderm in EB formation, resulting in limited yield. Our study aimed at upregulating chondrogenic differentiation of murine ESCs by enhancing mesoderm formation. Specifically, culture of mESCs with conditioned medium from a human hepatocarcinoma cell line resulted in a cell population with a gene expression pattern similar to that of primitive streak/nascent mesoderm, including up-regulation of brachyury, goosecoid, nodal, and cripto. From this cell population, reducing the embryoid body formation time resulted in enhancement of chondrogenic differentiation, as evidenced by larger Alcian blue-stained cartilage nodules, higher production of sulfated glycosaminoglycan matrix, the presence of well-organised type II collagen and type II collagen, aggrecan and sox-9 gene expression. In conclusion, we present here a new approach to the generation of chondrocytes from mESCs that enhances yields and, thus, could have widespread applications in cartilage tissue engineering.

Study on Biological Activity of Bread Enriched with Natural Polyphenols in Terms of Growth Inhibition of Tumor Intestine Cells

Dominik Szwajgier,Roman Paduch,Wirginia Kukula-Koch,Magdalena Polak-Berecka,Adam Wasko 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.2

A complex plant polyphenolic preparation (PP) was produced from chokeberry, raspberry, wild strawberry, peach, bilberry, apricot, cranberry, and parsley, using ultrafiltration and C18 preparative chromatography. Thirty main compounds were identified in PP (LC-MS), with the highest contribution of cyanidin 3-O-glucoside, p-coumaroyl glucoside, chlorogenic acid, neochlorogenic acid, and isoquercetin. PP was used (at 0.16% m/m) for the production of a sourdough bread (based on rye flour, water, and salt), followed by in vitro digestion. Fluid obtained after PP-enriched bread digestion (EBD fluid) was tested in terms of cytotoxicity, growth inhibition, antioxidant activity, and morphological changes in cancerous intestinal epithelial cells (HT-29) and normal (CCD 841 CoTr). Results show that EBD fluid concentration over 125 μg/mL significantly decreased activity of succinate dehydrogenase in HT-29 cells and reduced their viability of 25%. At this concentration of EBD fluid, modification in cellular morphology was also observed. DPPH analysis revealed that the highest antioxidant activity was observed at concentration of 75 μg/mL, both PP and EBD fluid. Our results show that an introduction of PP into relatively low-polyphenolic, baking products should be carefully considered because polyphenols still retain its biological activity. Antioxidant activity of polyphenols is one of the mechanisms that explains the observed effect of inhibiting the growth of colon cancer cells.