共查询到20条相似文献，搜索用时 72 毫秒
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Kavita K. Shalia V. K. Shah M. R. Mashru S. L. Soneji J. B. Vasvani S. Payannavar A. Walvalkar R. Mokal S. S. Mithbawkar M. Bootwalla P. Sadvekar P. K. Thakur 《Indian journal of clinical biochemistry : IJCB》2010,25(2):133-140
Matrix metalloproteinases (MMPs) play important role in the pathogenesis of coronary artery disease (CAD). 5A allele of -1612 5A/6A polymorphism of MMP-3 is associated with two fold higher activity than 6A allele. Present study was designed to analyse the association of this polymorphism with CAD in Indian population. Subjects included in the study were patients with stable angina (n=35), unstable angina (n=53), patients with recent event of myocardial infarction (MI) (MI Group-1, n=56) and patients at presentation of the acute MI (MI Group-2, n=49). Controls were healthy individuals (n=99). Genotyping of MMP-3 5A/6A polymorphism was carried out by PCR-based restriction digestion method. The genotype distribution of patient groups did not deviate from controls. Serum MMP-3 levels were significantly elevated at presentation of the acute MI by 36.8% (P=0.031) as compared to controls and more associated with 6A genotype suggesting discrepancy between in vitro transfection experiment and peripheral MMP-3 levels. 相似文献
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K. Sri Manjari Pratibha Nallari A. Vidyasagar A. Jyothy A. Venkateshwari 《Indian journal of clinical biochemistry : IJCB》2012,27(2):152-156
Chronic pancreatitis (CP) presenting clinically with upper abdominal pain, as well as exocrine and endocrine insufficiencies, is characterized by irreversible morphological and functional alterations in the pancreas. The objective of the present study is to investigate the plasma levels of transforming growth factor-β 1 (TGF-β1), matrix metalloproteinases MMP-1 (collagenase) and MMP-3 (stromelysin) in CP. A total of 71 CP patients and 100 control subjects were considered for the study. Plasma levels of TGF-β1, MMP-1 and MMP-3 were determined by enzyme-linked immunosorbent assay in patients and control subjects. The plasma levels of TGF-β1 and MMP-1 were significantly elevated in patients compared to control group (*P = 0.0301, **P < 0.0001). However, there was no significant difference in the plasma levels of MMP-3 between patients and controls (P = 0.3756). The elevated levels of TGF-β1 and MMP-1 may influence the inflammatory reactions by enhancing the pancreatic stellate cell activation and deposition of extracellular matrix resulting in pancreatic fibrosis. Thus, the present study highlights the role of fibrogenic cytokine marker TGF-β1 and matrix metalloproteinases in the pathogenesis of CP. 相似文献
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首乌藤提取物对动物脂肪酸合酶的抑制及其减肥抑食作用 总被引：1，自引：0，他引：1
最新报道脂肪酸合酶（FAS）是治疗肥胖症的潜在靶部位。实验测定表明，中药首乌藤的提取物对FAS具有很强的抑制作用，半抑制浓度为0.61±0.024g/ml。同时测定，该提取物对FAS中的酮酰还原反应有强抑制，半抑制浓度为2.14±0.12g/ml，说明FAS中的酮酰还原酶是该提取物的作用部位之一。抑制动力学分析表明，首乌藤提取物对FAS的抑制和底物乙酰辅酶A、丙二酸单酰辅酶A之间皆呈非竞争性关系；和NADPH之间在低抑制剂浓度下的表现近似反竞争性，在高抑制剂浓度下接近竞争性的关系。推测首乌藤中可能有多种FAS抑制剂。用首乌藤提取物口服饲喂大鼠和小鼠，可明显减低实验动物的摄食量和体重；测定实验组大鼠肝脏的FAS活性，明显低于对照组。实验结果对于研究FAS抑制剂和抑制机制以及在防治肥胖症的应用上可能具有重要的价值。 相似文献
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S. Sandya M. A. Achan P. R. Sudhakaran 《Indian journal of clinical biochemistry : IJCB》2009,24(1):42-48
To study the relative contribution of various matrix degrading enzymes in the pathogenesis of arthritis, changes in the levels
of various matrix metalloprtoteinases (MMPs) during the progression of collagen induced arthritis was studied in experimental
animals. Arthritis was induced in male wistar rats by injecting an emulsion containing collagen type II and Freund’s complete
adjuvant. The duration of the experiment was 35 days. Synovial effusate was collected at regular intervals after induction.
At the end of the experiment serum and cartilage were collected and analysed. Synovial fluid of osteoarthritic patients was
also analyzed. Levels of MMP-2, MMP-3, MMP-9 and MT1-MMP were found to be high in synovial effusate and cartilage of experimental
animals. In synovial effusate of arthritic animals the expression of MMP-3 was found to be high during the early stages while
increase in MMP-2 and MMP-9 occurred at later stages. Synovial fluid of osteoarthritic patients also showed elevated levels
of MMP-2, MMP-3 and MMP-9. Our results indicated that sequential action of MMPs such as MMP-3, MMP-2 and MMP-9 can cause degradation
of articular cartilage extracellular matrix. 相似文献
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利用酶动力学方法测定了50％乙醇红茶萃取物和其主要活性成分茶黄素对存在于动物中的I型脂肪酸合酶的酮酰还原催化中心（KR）和存在于细菌中的II型脂肪酸合酶的酮酰还原酶（FabG）的抑制能力和抑制特征。这两个抑制剂对KR和FabG均有强的可逆抑制和不可逆抑制能力，是KR和FabG的底物NADPH的竞争性抑制剂，并且NADPH可以显著降低它们不可逆失活KR和FabG的速率，表明这两个抑制剂可能作用于两种酮酰还原酶的NADPH结合位点。两个抑制剂对KR和FabG的抑制特征基本一致，表明两种不同进化程度的酮酰还原酶的活性部位很相似。序列同源性分析表明它们有一段同源性很高的序列，可能与活性部位组成有关。因此，通过对FabG的研究能够了解KR活性部位的空间结构。由于抑制能力强和来源丰富，这二个抑制剂具有较高的应用潜力。 相似文献
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Malaria infection is known to cause severe hemolysis due to production of abnormal RBCs and enhanced RBC destruction through apoptosis. Infected RBC lysis exposes uninfected RBC to the large amount of pro-oxidant molecules such as methemoglobin. Methemoglobin (MetHb) exposure dose dependently makes RBCs susceptible to osmotic stress and causes hemolysis. MetHb mediated oxidative stress in RBC correlated well with osmotic fragility and hemolysis. Interestingly, a reactive oxygen species (ROS) spike at 15 min was responsible for the observed effects on RBC cells. Two natural antioxidants N-acetyl cysteine and mannitol protected the RBC from MetHb-mediated defects, which clearly indicated involvement of oxidative stress in the process. MetHb due to its pseudo-peroxidase activity produces ROS in the external microenvironment. Therefore, classical peroxidase inhibitors were tested to probe peroxidase activity mediated ROS production with defects in RBCs. Clotrimazole (CLT), which irreversibly inactivates the MetHb (CLT-MetHb) and abolishes peroxidase activity, did not produce significant ROS outside RBC and was inefficient to cause osmotic fragility and hemolysis. Hence, initiating a chain reaction, MetHb released from ruptured RBC produces significant ROS in the external microenvironment to make RBC membrane leaky and enhanced hemolysis. Together data presented in the current work explored the role of MetHb in accelerated humorless during malaria which could be responsible for severe outcomes of pathological disorders. 相似文献
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Droplet microfluidics is a powerful method used to characterize chemical reactions at high throughput. Often detection is performed via in-line optical readout, which puts high demands on the detection system or makes detection of low concentration substrates challenging. Here, we have developed a droplet acoustofluidic chip for time-controlled reactions that can be combined with off-line optical readout. The principle of the platform is demonstrated by the enzymatic conversion of fluorescein diphosphate to fluorescein by alkaline phosphatase. The novelty of this work is that the time of the enzymatic reaction is controlled by physically removing the enzymes from the droplets instead of using chemical inhibitors. This is advantageous as inhibitors could potentially interact with the readout. Droplets containing substrate were generated on the chip, and enzyme-coupled microbeads were added into the droplets via pico-injection. The reaction starts as soon as the enzyme/bead complexes are added, and the reaction is stopped when the microbeads are removed from the droplets at a channel bifurcation. The encapsulated microbeads were focused in the droplets by acoustophoresis during the split, leaving the product in the side daughter droplet to be collected for the analysis (without beads). The time of the reaction was controlled by using different outlets, positioned at different lengths from the pico-injector. The enzymatic conversion could be measured with fluorescence readout in a separate PDMS based assay chip. We show the ability to perform time-controlled enzymatic assays in droplet microfluidics coupled to an off-line optical readout, without the need of enzyme inhibitors. 相似文献
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草莓提取物对脂肪酸合酶及脂肪细胞的抑制作用 总被引：1，自引：0，他引：1
脂肪酸合酶(FAS)是治疗肥胖症的潜在靶点.实验测定表明,草莓果肉渣及草莓叶的乙醇提取物再经乙酸乙酯萃取的有效组分对FAS具有强抑制作用,且分别对FAS的底物丙二酸单酰辅酶A、乙酰辅酶A呈非竞争性和竞争性抑制.经HPLC-MS分析,槲皮素和鞣花酸可能是草莓有效组分中起主要作用的物质.草莓叶及果肉渣乙酸乙酯提取组分均可有效抑制3T3-L1前脂肪细胞中脂滴积累,且呈剂量依赖性.实验结果对于研究草莓在防治肥胖症的应用上可能具有重要价值. 相似文献
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S. R. Pardesi S. P. Dandekar S. N. Jamdar P. Harikumar 《Indian journal of clinical biochemistry : IJCB》2004,19(2):84-90
To purify and evaluate the molecular changes associated with an aspartic protease (Cathepsin D) in human semen from infertile
subjects. Cathepsin D was purified from normo-, oligo- and azoospermic semen, by a procedure involving detergent solubilisation,
affinity chromatography and gel filtration chromatography. The enzyme from normo-, oligo- and azoospermic samples was purified
86, 60 and 44 fold respectively. The purified enzyme appeared as a single band on SDS as well as on native PAGE irrespective
of the pathological conditions. The molecular weight of Cathepsin D from oligospermic and normospermic samples was 40 kDa
while that of azoospermic sample was found to be 43 kDa. The enzyme was inhibited by pepstatin while other proteinase inhibitors
and metal ions did not have any effect. Purified Cathepsin D from azoospermic sample differs from normospermia and oligospermia. 相似文献
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为解决人工饲料育蚕发育不齐问题 ,就饲料的不同调制方法对桑蚕幼虫发育的影响以及同一蚕品种个体间的差异进行了研究 .结果发现 :1)在饲料制作上必须进行蒸煮灭菌 ,微波炉加热灭菌与蒸煮的效果相近 ,不经加热杀菌简易化制作的效果都不理想 ;2 )同一蚕品种个体间对人工饲料的摄食性存在差异 .对桑叶粉及蔗糖等摄食促进物质的感受性 ,高食性蚕比低食性蚕敏感 ;而对豆粕粉中摄食阻碍物质的感受性 ,低食性蚕比高食性蚕敏感 .研究认为 ,要提高人工饲料育蚕的群体摄食性和发育整齐度 ,应尽量消除饲料中的摄食阻碍物质或选育出对摄食阻碍物质具适应性的蚕品种 相似文献
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《Information processing & management》2020,57(5):102270
Identifying perceived emotional content of music constitutes an important aspect of easy and efficient search, retrieval, and management of the media. One of the most promising use cases of music organization is an emotion-based playlist, where automatic music emotion recognition plays a significant role in providing emotion related information, which is otherwise, generally unavailable. Based on the importance of the auditory system in emotional recognition and processing, in this study, we propose a new cochleogram-based system for detecting the affective musical content. To effectively simulate the response of the human auditory periphery, the music audio signal is processed by a detailed biophysical cochlear model, thus obtaining an output that closely matches the characteristics of human hearing. In this proposed approach, based on the cochleogram images, which we construct directly from the response of the basilar membrane, a convolutional neural network (CNN) is used to extract the relevant music features. To validate the practical implications of the proposed approach with regard to its possible integration in different digital music libraries, an extensive study was conducted to evaluate the predictive performance of our approach in different aspects of music emotion recognition. The proposed approach was evaluated on publicly available 1000 songs database and the experimental results showed that it performed better in comparison with common musical features (such as tempo, mode, pitch, clarity, and perceptually motivated mel-frequency cepstral coefficients (MFCC)) as well as official ”MediaEval” challenge results on the same reference database. Our findings clearly show that the proposed approach can lead to better music emotion recognition performance and be used as part of a state-of-the-art music information retrieval system. 相似文献
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The relationship between protease and Desferal production was assayed. Experiments were performed using a cultivation of Streptomyces pilosus ATCC 19797 in soybean broth medium containing 2% soybean flour and 2% mannitol. The metabolism of the trihydroxamic acid sidrophore desferrioxamine B and protease production by a S. pilosus in nine continues days after culture were investigated as well as the effect of protease inhibitors was examined. It is found that the Desferal formation decreased with increased protease production. Also the effect of protease inhibitors and minerals in determined day of protease production in the culture medium by S. pilosus has been investigated. 相似文献
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知识经济情境下,知识转移对于产学研用协同创新的绩效至关重要。文章引入模块化理论来研究产学研用协同创新过程中的知识转移问题,并重点从产品模块化和组织模块化的视角分别探讨了知识转移的协调机制。在此基础上,以海尔为案例系统地分析了其产品模块化和产学研用协同创新实践,讨论了案例企业采用模块化手段与外部合作资源开展知识交互,以及基于模块化的知识转移协调机制的具体应用。研究发现：模块化不但有助于推动企业与高校、科研院所从“面对面”转向“背靠背”的产学研用协同创新,更有利于调节知识供需双方的知识转移策略;模块接口则作为知识供需双方消除信息不对称、实施知识转移的重要管道。本研究可以为中国企业探索需求驱动下的产学研协同创新模式以及实施知识转移提供借鉴。 相似文献
15.
A transverse diffusion mediated capillary microanalysis method has been developed for screening of neuraminidase inhibitors from traditional Chinese medicine. The enzyme, substrate and inhibitors were sequentially injected, mixed efficiently by transverse diffusion of laminar flow profiles, then incubated and separated in the same capillary. To enhance the mixing efficiency of reactants, running buffer was injected by alternately applying +5 kPa and −5 kPa at the capillary inlet and the procedure was repeated three times. The capillary electrophoresis (CE) separation conditions and reactants mixing conditions were optimized. Dual-wavelength detection was employed to eliminate the interference with natural compounds. The method has been applied to determine the kinetics constant of neuraminidase and screen 12 compounds from traditional Chinese medicine. Four compounds have been found to be positive for enzyme inhibition. The results are in good agreement with those reported in the literature. The method realized the mixing of substrate and enzyme with identical electrophoretic mobility. This novel CE method was simple, rapid, economic, and fully automated. Therefore, it was appropriate for neuraminidase inhibitors screening and could be extended to other high-throughput screening of active components from traditional Chinese medicine. 相似文献
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BackgroundChia seeds are gaining increasing interest among food producers and consumers because of their prohealth properties.ResultsThe aim of this work was to evaluate the potential of chia seeds to act as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. The highest inhibitory activity against AChE and BChE was observed for colored seed ethanol extracts. A positive correlation was found between the presence of quercetin and isoquercetin as well as protocatechuic, hydroxybenzoic, and coumaric acids and the activity of extracts as AChE and BChE inhibitors. It has also been shown that grain fragmentation affects the increase in the activity of seeds against cholinesterases (ChE). Furthermore, seeds have been shown to be a source of substances that inhibit microbial growth.ConclusionsIt was found that the chia seed extracts are rich in polyphenols and inhibit the activity of ChEs; therefore, their use can be considered in further research in the field of treatment and prevention of neurodegenerative diseases.How to cite: Kobus-Cisowska J, Szymanowska D, Maciejewska P, et al. In vitro screening for acetylcholinesterase and butyrylcholinoesterase inhibition and antimicrobial activity of chia seeds (Salvia hispanica). Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.10.002 相似文献
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Mamatha Kunder V. Lakshmaiah A. V. Moideen Kutty 《Indian journal of clinical biochemistry : IJCB》2018,33(2):218-221
Dengue fever (DF) is characterized by systemic inflammatory response including neutrophil activation leading to uncontrolled elastase activity. This study was aimed to measure the activity of plasma neutrophil elastase (NE), its endogenous inhibitors α1-antitrypsin (α1-AT) and α2-macroglobulin (α2-MG) and elastase in complex with α1-AT (NE–α1-AT complex) in DF. 50 dengue patients [39 DF and 11 dengue hemorrhagic fever (DHF)] and 52 healthy subjects were included in the study. NE was measured using N-succinyl-tri-alanine-p-nitroanilide as substrate. α1-AT, α2-MG and NE–α1-AT complex were estimated by ELISA. The result analysis indicated that the dengue patients had significantly higher elastase activity with significantly reduced inhibitor levels compared to controls. Between DF and DHF patients, DHF group had significantly higher elastase activity. In conclusion, significantly elevated NE and reduced inhibitors level in dengue fever indicate these parameters could be of significance in DF particularly for the assessment of progression of inflammatory processes. 相似文献
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This study extends and tests the dual factor model of technology usage (Cenfetelli, 2004, Cenfetelli and Schwarz, 2011), which recognizes enablers and inhibitors as two distinct constructs in the context of social media. We test the effect of two enablers: perceived usefulness and perceived enjoyment on perceived communication quality and social media continuance intention. We advance the understanding of the conceptualization of inhibitors from object-based, social-based, behavioral-based, and affective-based perspectives. We investigate the moderating effects of affective-based inhibitors (i.e., perceived social media distress and perceived social media anxiety) and the direct effects of object-based inhibitor (rapid change), social-based inhibitor (i.e., distorted reputation), and behavioral-based inhibitor (perceived complexity) on communication quality and continuance intention. To test the hypotheses, we collected data using an Online Crowdsourcing Markets (OCMs) technique. Using a sample of 268 Facebook users, our findings suggest perceived enjoyment is the main enabler, whereas perceived complexity is the main inhibitor of social media continuance intention. The findings also suggest that perceived social media anxiety moderates the relationships between (1) perceived complexity and perceived enjoyment, (2) perceived complexity and perceived usefulness, and (3) perceived complexity and perceived communication quality. We also find distorted reputation has a positive effect on perceived complexity but rapid change does not have a significant effect on perceived complexity. Perceived communication quality also significantly influences social media continuance intention. Our study confirms the dual factor model of technology usage and advances social media research by demonstrating that inhibitors are distinct from enablers. 相似文献
19.
四川边茶提取物对脂肪酸合酶的抑制作用 总被引：2，自引：0，他引：2
四川边茶（康砖）是黑茶的一个主要品种，所含茶多酚与绿茶和红茶不同。本研究利用酶动力学方法测定了边茶萃取物对脂肪酸合酶（Fatty Acid Synthase, FAS, E.C. 2.3.1.85）的抑制作用，近几年研究报道该酶是减肥和抑癌的双重潜在靶点。结果表明，边茶萃取物对FAS有可逆和不可逆抑制双重作用，最佳萃取溶剂为50％的乙醇，在常温下5 h即可达到最佳萃取效果。用开水泡茶的方法经两次浸取可提取出近60％的抑制FAS有效物，比绿茶的浸出效率约高1倍，但需较长的浸泡时间。边茶的新茶对脂肪酸合酶的抑制能力并不强，存放数年的边茶抑制能力最好，其后有所下降，但大部分抑制活性可保持20年以上，而30年以上保存期可能会使抑制能力明显下降。边茶提取物与底物乙酰辅酶A和丙二酸单酰辅酶A的竞争性质都是竞争性与非竞争性的混合型；对FAS中的酮酰还原反应的抑制不明显，这说明酮酰还原酶结构域并不是其主要作用位点；这些和绿茶及红茶都有不同。由实验结果分析边茶中的抑制剂不同于红茶和绿茶，可能是茶多酚中的茶褐素，其抑制能力高于儿茶素而接近茶黄素。这些结果表明边茶在减肥、抑癌等方面可能具有良好的应用前景。 相似文献
20.
Muthuswamy Balasubramanyam Raji Lenin Finny Monickaraj 《Indian journal of clinical biochemistry : IJCB》2010,25(2):111-118
The endoplasmic reticulum (ER) is a cellular compartment responsible for multiple important cellular functions including the
biosynthesis and folding of newly synthesized proteins destined for secretion, such as insulin. A myriad of pathological and
physiological factors perturb ER function and cause dysregulation of ER homeostasis, leading to ER stress. Accumulating evidence
suggests that ER stress plays a role in the pathogenesis of diabetes, contributing to pancreatic β-cell loss and insulin resistance.
ER stress may also link obesity, inflammation and insulin resistance in type 2 diabetes. In this review, we address the transition
from physiology to pathology, namely how and why the physiological UPR evolves to a proapoptotic ER stress response in diabetes
and its complications. Special attention was given to elucidate how ER stress could explain some of the ‘clinical paradoxes’
such as secondary sulfonylurea failure, initial worsening of retinopathy during tight glycemic control, insulin resistance
induced by protease inhibitors and other clinically relevant observations. 相似文献