NGHIÊN CỨU THU NHẬN PROTEIN TỪ CÁM GẠO

Rice bran protein, a plant protein, has been recognized as nutritionally superior to other proteins due on its reported hypoallergenicity and anti-cancer activity. Therefore, it is considered as a promising protein resource applicable in variety of fields such as functional food, cosmetics, livestock and medicine. However, as of now, commercial rice bran protein is not widely available on the market, especially in Vietnam, because of a lack of extraction methods currently in use. In particular, the available methods can not be used to obtain protein isolates of high quality at affordable commercial price. Vietnam is one of the bigest rice export countries in the world, that makes rice bran an abundant agricultural by-product and thus, a readily sufficient source for protein extraction. This study aimed to establish a simple processing method for extraction of high content of protein isolates from rice bran. The obtained results indicated that rice bran was effectively hydrolysed in 20 minutes with α-amylase (Ternamyl) at concentration of 0.25%, pH 7.0 and 90oC. A procedure of 8 steps for protein extraction was given: i) Suspend rice bran in water and stir for 30 minutes at room temperature; ii) Adjust the suspension to pH 9.0 with NaOH 1N and stir for 4 hours; iii) Adjust the suspension to pH 7.0 with HCl 1N, add 0,25% Ternamyl at 90 oC and hydrolyse for 20 minutes; iv) Centrifuge at 4000 rpm for 20 minutes to collect the supernatant; v) Precipitate protein isolates at pH 4.0 by adding HCl 1N; vi) Centrifuge at 4000 rpm for 20 minutes to collect protein isolates; vii) Wash protein isolates twice with water; viii) Dry the isolates at 50oC. The content of protein isolates from this procedure was 41.77% and the yield of processing was 13,41%. The technological indexes including foaming capacity and emulsion activity were 20% and 73.50, respectively, which were higher compared to the same  product from China.Protein cám gạo là loại protein thực vật có giá trị dinh dưỡng vượt trội do có khả năng chống ung thư và không gây dị ứng cho người sử dụng. Vì thế, nó được xem là một protein lương thực cao cấp, có thể ứng dụng trong nhiều lĩnh vực như chăn nuôi, thực phẩm chức năng, thực phẩm dinh dưỡng, mỹ phẩm và y học. Protein này vẫn chưa được thương mại phổ biến trên thị trường, đặc biệt là ở Việt Nam, vì những hạn chế của các phương pháp tách chiết đang sử dụng hiện nay chưa cho phép thu được sản phẩm có chất lượng cao với giá thành phù hợp. Việt Nam là nước sản xuất lúa gạo đứng thứ hai trên thế giới nên nguồn nguyên liệu phụ thải cám gạo cho mục đích tách chiết protein là vô cùng phong phú. Bài báo này trình bày nghiên cứu về xây dựng một quy trình tách chiết protein cám gạo tương đối đơn giản, cho phép thu nhận được protein có hàm lượng tương đối cao. Kết quả nghiên cứu cho thấy α-amylase (Ternamyl) ở nồng độ 0,25%, pH 7.0, nhiệt độ 90­oC, thời gian thủy phân 20 phút có khả năng loại bỏ hiệu quả  tinh bột từ nguyên liệu. Quy trình công nghệ thu nhận protein từ cám gạo xây dựng được gồm 8 bước chính: i) Dịch cám gạo trong nước cất (1:7) được khuấy trong 30 phút; ii) Điều chỉnh dịch cám gạo tới pH 9.0 bằng NaOH 1N và tiếp tục khuấy trong 4 giờ ở nhiệt độ phòng; iii) Điều chỉnh dịch cám gạo về pH 7.0 bằng HCl 1N, bổ sung Termamyl 0,25% ở 90oC và tiến hành thủy phân trong 20 phút; iv) Ly tâm 4000 vòng trong 20 phút để thu dịch trong; v) Tủa protein ở dịch ly tâm bằng HCl 1N tại pH 4.0; vi) Ly tâm thu cặn tủa ở 4000 vòng trong 20 phút; vii) Rửa cặn tủa 2 lần bằng nước khử trùng; viii) Sấy khô mẫu ở 50oC thu protein. Protein thu được từ quy trình này có hàm lượng đạt 41,77% và hiệu suất là 13,41%. Các chỉ số công nghệ của chế phẩm bao gồm độ tạo bọt đạt 20%, độ tạo nhũ tương đạt 73,45, đều cao hơn so với protein đối chứng của Trung Quốc

Effects of antibiotics on the intestinal microcirculation in septic rats

Although the benefit of expedient antibiotic therapy remains unquestioned, little is known about the effects that are unrelated to their antimicrobial property but which the antibiotics may exert upon the septic microcirculation. Impairment of intestinal microcirculation has been recognized as an important factor in the pathogenesis of the septic syndrome (intestine = ¡°motor¡± of multiple organ failure). To examine the effects of various antibiotics on microcirculation is justified by the fact that one of major features of sepsis is disturbance of microcirculation. However, monitoring of pharmacological effects on intestinal blood flow is nearly impossible during acute therapy in humans and requires sophisticated equipment when applied to experimental animals. Therefore, the aim of this study was to evaluate the effects of common antibiotics on intestinal microcirculation using intravital microscopy (IVM) and on the release of the cytokines in septic and endotoxemic rats. In a first series of experiments we induced sepsis by using colon ascendens stent peritonitis (CASP) model in the rat (16 hours prior microscopy). We evaluated the effects of common antibiotics on intestinal microcirculation using intravital microscopy (functional capillary density (FCD) and leukocyte-endothelial interactions) and on the release of the cytokines TNF-¥á, IL-1©¬, IL-6 and IL-10. Metronidazole (MET) (10 mg/kg); imipenem (IMI) (20 mg/kg); tobramycin (TOB) (25 mg/kg); vancomycin (VAN) (70 mg/kg); and erythromycin (ERY) (5 mg/kg) were given intravenously 16 hours following sepsis induction. To differentiate antimicrobial from anti-inflammatory effects we performed a second series of experiments using endotoxin (LPS, i. v.) and intravital microscopic examination was performed 2 hours later. Cytokine release was estimated at the end of the experiments. In the CASP model, acute administration of metronidazole was associated with an improvement of markers of the intestinal microcirculation in septic rats (CASP). Our study showed that vancomycin stimulated leukocyte rolling, while erythromycin prevented the activation of leukocyte-endothelial interaction in postcapillary intestinal venules (V1) that occurred within 16 hours after CASP. TNF-¥á release in untreated CASP rats was twice as high in comparison to all antibiotic-treated CASP rats, except in CASP rats treated with tobramycin. Key findings of the present study are that MET and ERY were more potent than other antibiotics in improving the intestinal microcirculation in the CASP model. Protective effects of metronidazole, erythromycin and vancomycin upon the microcirculation were found in LPS model. The administration of MET or VAN or ERY led to significantly higher FCD values within the longitudinal muscular layers. Metronidazole and erythromycin significantly reduced the n umber of sticking leukocytes within the V1-venules of LPS-challenged animals. Leukocyte rolling flux was significant increased within the V1- and V3-venules of the endotoxemic rats treated with VAN. Some antibiotics showed immuno-modulatory effects: MET or IMI or VAN treated LPS rats showed increased IL-10 levels; while ERY treated LPS rats showed decreased IL-1©¬ and increased IL-6 concentrations. In conclusion, metronidazole and erythromycin exerted a positive influence upon the intestinal perfusion not only within septic microcirculation (anti-bacterial effect) but also in a pathogenically independent manner (anti-inflammatory effect); vancomycin had only anti-inflammatory actions in the endotoxin model without bacterial infection. Imipenem and tobramycin had no effect on intestinal microcirculation in septic and endotoxemic rats. The clinical usefulness of studies such as this is that they could provide important information about possible side effects or indicate some potential beneficial effects of the antibiotics. They can influence not only microcirculation but also inflammatory processes by some mechanisms that are probably unrelated to their antibiotic effect. However, these effects may be particularly relevant to the intestinal microcirculation which plays an essential role in the development of multi-organ failure in the instance of sepsis.keine Angabe

Optimized extraction conditions of polysaccharides from Pseuderanthemum crenulatum (Wall. ex Lindl.) Radlk.

Polysaccharide has attracted great attentions for its benefits to human health. Polysaccharide from natural sources have diverse anti-inflammatory, anticoagulant and wound healing activities. Polysaccharide is not only valuable in medicine, also widely used in foodstuffs such as gel thickening or emulsifying agents, emulsifiers, fillers. Recently there has been an increase in the demand for polysaccharides, so research into new sources of polysaccharide with plant-based bio-activity is essential. Pseuderanthemum crenulatum (Wall. ex Lindl.) Radlk belong to genus of Pseuderanthemum. Common names (Vietnamese): Xuân hoa răng. This species is native in the forests of Vietnam. The polysaccharide content in P. crenulatum leaves was (7.47 ± 0.6) % in dry weight. The appropriate polysaccharide extraction conditions were determined: material/ water ratio (1g/25ml), extracted temperature of 60°C, extraction time 12 hours. The polysaccharide composition was purified by TCA 10%, with a purity of (55.6 ± 1.19) %.Trong những năm gần đây, polysaccharide là nhóm hợp chất rất được các nhà khoa học trên thế giới quan tâm do các tác dụng quan trọng của chúng về tăng cường miễn dịch, kháng viêm, làm lành vết thương, chống ung thư… Polysaccharide không những có giá trị trong Y học mà còn được sử dụng rộng rãi trong thực phẩm như các chất tạo độ đặc hay tạo gel, chất làm bền nhũ tương, chất độn… Hiện nay, nhu cầu sử dụng polysaccharide từ thực vật ngày càng gia tăng nên việc điều tra, khai thác nguồn polysaccharide mới có hoạt tính sinh học là rất cần thiết. Pseuderanthemum crenulatum (Wall. ex Lindl.) Radlk thuộc chi Pseuderanthemum sp, tên thông thường là cây Xuân hoa răng, là cây mọc tự nhiên trong rừng Việt nam. Trong nghiên cứu này, chúng tôi đã tách chiết, xác định hàm lượng và tinh sạch sơ bộ polysaccharide từ lá cây Pseuderanthemum crenulatum. Hàm lượng polysaccharide trong lá cây Xuân hoa răng đạt (7.47 ± 0.6) % trọng lượng khô. Các điều kiện chiết rút polysaccharide thích hợp đã được xác định: nhiệt độ chiết rút 60°C, tỷ lệ nguyên liệu/nước (1g mẫu khô/25ml nước), thời gian chiết rút 12 giờ. Chế phẩm polysaccharide đã được tinh sạch bằng TCA 10%, có độ sạch đạt (55.6 ± 1.19)%

A survey of itemset mining

Itemset mining is an important subfield of data mining, which consists of discovering interesting and useful patterns in transaction databases. The traditional task of frequent itemset mining is to discover groups of items (itemsets) that appear frequently together in transactions made by customers. Although itemset mining was designed for market basket analysis, it can be viewed more generally as the task of discovering groups of attribute values frequently cooccurring in databases. Because of its numerous applications in domains such as bioinformatics, text mining, product recommendation, e-learning, and web click stream analysis, itemset mining has become a popular research area. This study provides an up-to-date survey that can serve both as an introduction and as a guide to recent advances and opportunities in the field. The problem of frequent itemset mining and its applications are described. Moreover, main approaches and strategies to solve itemset mining problems are presented, as well as their characteristics are provided. Limitations of traditional frequent itemset mining approaches are also highlighted, and extensions of the task of itemset mining are presented such as high-utility itemset mining, rare itemset mining, fuzzy itemset mining, and uncertain itemset mining. This study also discusses research opportunities and the relationship to other popular pattern mining problems, such as sequential pattern mining, episode mining, subgraph mining, and association rule mining. Main open-source libraries of itemset mining implementations are also briefly presented. WIREs Data Mining Knowl Discov 2017, 7:e1207. doi: 10.1002/widm.120

Neutral Polysaccharide from the Leaves of Pseuderanthemum carruthersii: Presence of 3-O-Methyl Galactose and Anti-Inflammatory Activity in LPS-Stimulated RAW 264.7 Cells

Pseuderanthemum carruthersii (Seem.) Guillaumin is a native tree in Vietnam. The water extract of the leaves from this tree gives a highly viscous product that has been used to heal wounds and treat inflammations. Our previous studies showed that the leaves of P. carruthersii have a high content of polysaccharides. In this study, the structure and influence of the neutral polysaccharide from Pseuderanthemum carruthersii (PCA1) on lipopolysaccharide (LPS)-stimulated RAW264.7 cells were investigated. The PCA1 isolated from P. carruthersii is a galactan-type polysaccharide, containing galactose (77.0%), 3-O-methyl galactose (20.0%), and arabinose (3.0%). Linkage analysis of PCA1 showed that both the 3-O-methyl galactose and galactose were 1,4-linked. The presence of 3-O-methyl galactose units as part of the polysaccharide is important and can be used as a chemotaxonomic marker. The molecular weight of the PCA1 was 170 kDa. A PCA1 concentration of 30–40 μg/mL strongly inhibited TNFα, IL-1β, and IL-6 inflammatory cytokine production, and reactive oxygen species (ROS) release. PCA1 had inhibitory activities on pro-inflammatory cytokine and ROS release in LPS-stimulated mouse macrophages in vitro through MAPK signaling