Journal of biochemical and biophysical methods最新文献_第4页

A procedure for the rapid screening of Maillard reaction inhibitors 美拉德反应抑制剂的快速筛选方法

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 DOI: 10.1016/j.jprot.2007.10.002

Shamila Fatima , Deeba S. Jairajpuri , M. Saleemuddin

{"title":"A procedure for the rapid screening of Maillard reaction inhibitors","authors":"Shamila Fatima , Deeba S. Jairajpuri , M. Saleemuddin","doi":"10.1016/j.jprot.2007.10.002","DOIUrl":"10.1016/j.jprot.2007.10.002","url":null,"abstract":"<div><p>A procedure for the rapid screening of inhibitors of glycation reaction, based on their ability to protect RNase against sugar induced inactivation of the enzyme is described. Glycation is implicated in variety of disorders including diabetes, atherosclerosis various micropathies yet is a slow process both in vivo and in vitro. In order to speed up glycation, the reaction was carried out at 60 °C using a thermostable protein RNase and ribose, a sugar that is known to react rapidly than glucose in the glycation reaction. It was observed that incubation of RNase with ribose at 60 °C in rapid inactivation of the enzyme with a parallel decrease in tyrosine fluorescence, enhancement in new fluorescence and hyperchromicity in the UV-region. No such alterations in the enzyme activity were observed when the incubation was carried out in absence of the sugar. Compounds and drugs that are known to act as inhibitors of glycation reaction restricted the ribose-induced inactivation of RNase. RNase immobilized on CNBr-activated Sepharose was also sensitive to exposure to ribose and appeared a better system to screen inhibitors of glycation from natural sources that contain substances that interfere with the assay of enzyme as well as in the study of post Amadori inhibitors of glycation.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 958-965"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jprot.2007.10.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27131914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Assessment of pelt quality in leather making using a novel non-invasive sensing approach 用一种新颖的非侵入式传感方法评估皮革生产中的毛皮质量

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 DOI: 10.1016/j.jbbm.2007.07.003

S.C. Mukhopadhyay , S. Deb Choudhury , T. Allsop , V. Kasturi , G.E. Norris

引用次数: 39

A method to fabricate mesoscopic freestanding polydimethylsiloxane membranes used to probe the rheology of an epithelial sheet 一种制备介观独立聚二甲基硅氧烷膜的方法，用于探测上皮片的流变学

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 DOI: 10.1016/j.jbbm.2007.07.005

John C. Selby , Mark A. Shannon

{"title":"A method to fabricate mesoscopic freestanding polydimethylsiloxane membranes used to probe the rheology of an epithelial sheet","authors":"John C. Selby , Mark A. Shannon","doi":"10.1016/j.jbbm.2007.07.005","DOIUrl":"10.1016/j.jbbm.2007.07.005","url":null,"abstract":"<div><p>Details are presented for the formulation, fabrication, and mechanical characterization of mesoscopic freestanding polydimethylsiloxane (PDMS) elastomer membranes, 10.0 μm thick and 5.0 mm in diameter, used to probe the rheology of a living epithelial sheet. In what is described as a composite diaphragm inflation (CDI) experiment, freestanding PDMS membranes are utilized as substrates for the culture of a sheet of epithelial cells. Together, the cell layer and the PDMS elastomer form a composite diaphragm (CD) that is suitable for mechanical testing in an axisymmetric membrane inflation experiment. In order to distinguish the rheological behavior of the epithelial sheet from the mechanical response of the elastomer using inflation test data, freestanding PDMS membranes should exhibit a highly compliant yet mechanically invariant finite load-deformation response when subjected to multiple inflation cycles following intermittent periods of cell culture. Given these considerations, we describe a method for preparing freestanding PDMS elastomer membrane specimens that are optically transparent, tensed, and wrinkle-free. Surface modifications intended to facilitate cell culture, namely water vapor plasma and ultraviolet light treatments, were shown to dramatically stiffen the mechanical response of the membranes, rendering them unusable as CD substrates. In this study, only PDMS membranes with physiosorbed collagen demonstrated the mechanical compliance, fatigue resistance, and environmental stability necessary for reliable use in CDI experiments.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 932-944"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jbbm.2007.07.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26946955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

Biomolecules/gold nanowires-doped sol–gel film for label-free electrochemical immunoassay of testosterone 生物分子/金纳米线掺杂溶胶-凝胶膜用于睾酮的无标记电化学免疫分析

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 DOI: 10.1016/j.jprot.2007.11.007

Ke-Zhong Liang , Jun-Sheng Qi , Wei-Jun Mu , Zai-Gang Chen

{"title":"Biomolecules/gold nanowires-doped sol–gel film for label-free electrochemical immunoassay of testosterone","authors":"Ke-Zhong Liang , Jun-Sheng Qi , Wei-Jun Mu , Zai-Gang Chen","doi":"10.1016/j.jprot.2007.11.007","DOIUrl":"10.1016/j.jprot.2007.11.007","url":null,"abstract":"<div><p>A direct, rapid, and label-free electrochemical immunoassay method for testosterone has been described based on encapsulating testosterone antibody into polyvinyl butyral sol–gel film doped with gold nanowires. Gold nanowires prepared by using nanopore polycarbonate membrane were used to conjugate testosterone antibody onto the probe surface. The presence of gold nanowires provided a biocompatible microenvironment for biomolecules, greatly amplified the immobilized amount of biomolecules on the electrode surface, and improved the sensitivity of the immunosensor. In comparison with gold nanoparticle-conjugating probe, the gold nanowire-functionalized probe could avoid the leakage of biomolecules from the composite film, and enhanced the stability of the sensor. The performance and factors influencing the performance of the resulting immunosensor were investigated in detail. Under optimal conditions, the developed immunosensor exhibited a good linear relationship with testosterone ranging from 1.2 to 83.5 ng mL<sup>−1</sup> with a detection limit of 0.1 ng mL<sup>−1</sup> (at 3<em>δ</em>). Moreover, the proposed immunosensor exhibited high sensitivity, good reproducibility and long-term stability. The as-prepared immunosensors were used to analyze testosterone in human serum specimens. Analytical results suggest that the developed immunoassay has a promising alternative approach for detecting testosterone in the clinical diagnosis. Compared with the conventional ELISAs, the proposed immunoassay method was simple and rapid without multiple labeling and separation steps. Importantly, the route provides an alternative approach to incorporate gold nanowires into the solid matrix for biosensing application.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 1156-1162"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jprot.2007.11.007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27188532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 54

Dispensing an enzyme-conjugated solution into an ELISA plate by adapting ink-jet printers 通过喷墨打印机将酶偶联溶液分配到ELISA板中

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 DOI: 10.1016/j.jbbm.2007.05.003

Luca Lonini , Dino Accoto , Silvia Petroni , Eugenio Guglielmelli

{"title":"Dispensing an enzyme-conjugated solution into an ELISA plate by adapting ink-jet printers","authors":"Luca Lonini , Dino Accoto , Silvia Petroni , Eugenio Guglielmelli","doi":"10.1016/j.jbbm.2007.05.003","DOIUrl":"10.1016/j.jbbm.2007.05.003","url":null,"abstract":"<div><p>The rapid and precise delivery of small volumes of bio-fluids (from picoliters to nanoliters) is a key feature of modern bioanalytical assays. Commercial ink-jet printers are low-cost systems which enable the dispensing of tiny droplets at a rate which may exceed 10<sup>4</sup> Hz per nozzle. Currently, the main ejection technologies are piezoelectric and bubble-jet. We adapted two commercial printers, respectively a piezoelectric and a bubble-jet one, for the deposition of immunoglobulins into an ELISA plate. The objective was to perform a comparative evaluation of the two classes of ink-jet technologies in terms of required hardware modifications and possible damage on the dispensed molecules. The hardware of the two printers was modified to dispense an enzyme conjugate solution, containing polyclonal rabbit anti-human IgG labelled with HRP in 7 wells of an ELISA plate. Moreover, the ELISA assay was used to assess the functional activity of the biomolecules after ejection. ELISA is a common and well-assessed technique to detect the presence of particular antigens or antibodies in a sample. We employed an ELISA diagnostic kit for the qualitative screening of anti-ENA antibodies to verify the ability of the dispensed immunoglobulins to bind the primary antibodies in the wells. Experimental tests showed that the dispensing of immunoglobulins using the piezoelectric printer does not cause any detectable difference on the outcome of the ELISA test if compared to manual dispensing using micropipettes. On the contrary, the thermal printhead was not able to reliably dispense the bio-fluid, which may mean that a surfactant is required to modify the wetting properties of the liquid.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 1180-1184"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jbbm.2007.05.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26794786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 26

Evaluation of electron spin resonance for studies of superoxide anion production by human neutrophils interacting with Staphylococcus aureus and Staphylococcus epidermidis 电子自旋共振对人类中性粒细胞与金黄色葡萄球菌和表皮葡萄球菌相互作用产生超氧阴离子研究的评价

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 DOI: 10.1016/j.jbbm.2007.05.014

Helen Lundqvist , Staffan Dånmark , Uno Johansson , Håkan Gustafsson , Karin Öllinger

{"title":"Evaluation of electron spin resonance for studies of superoxide anion production by human neutrophils interacting with Staphylococcus aureus and Staphylococcus epidermidis","authors":"Helen Lundqvist , Staffan Dånmark , Uno Johansson , Håkan Gustafsson , Karin Öllinger","doi":"10.1016/j.jbbm.2007.05.014","DOIUrl":"10.1016/j.jbbm.2007.05.014","url":null,"abstract":"<div><p>The present study evaluates electron spin resonance (ESR) and the spin trapper 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-<em>N</em>-oxide (DEPMPO) for analysis of superoxide radical production by human neutrophils interacting with viable <em>Staphylococcus aureus</em> and <em>Staphylococcus epidermidis</em> bacteria. To avoid auto-activation due to interaction with glass surfaces, neutrophils were preincubated in plastic tubes until the peak response was reached, and then transferred to a quartz flat cell to record the ESR spectra. The time point for peak response was identified by parallel analysis of the bacteria–neutrophil interaction using luminol amplified chemiluminescence. We found detectable ESR spectra from neutrophils interacting with as few as five bacteria of the weak activating <em>S. epidermidis</em> per neutrophil. Addition of the NADPH oxidase inhibitor diphenylene iodonium totally abolished spectra. Catalase, DMSO or an iron chelator had no impact on the produced spectra and ionomycin, a selective activator of intracellular NADPH oxidase, gave significant ESR spectra. Taken together, our results indicate that DEPMPO is cell permeable and detects NADPH oxidase derived superoxide anions formed in phagosomes or released by human neutrophils phagocytosing viable <em>S. aureus</em> and <em>S. epidermidis</em>. The technique may be used as a sensitive tool to evaluate superoxide anion production in human neutrophils.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 1059-1065"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jbbm.2007.05.014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26807006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Fatty acid composition of triacylglycerols from Wharton's jelly determined by high-performance liquid chromatography 高效液相色谱法测定华顿果冻中三酰基甘油的脂肪酸组成

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 DOI: 10.1016/j.jbbm.2007.09.004

Lech Romanowicz , Zofia Galewska , Tomasz Gogiel , Stefan Jaworski , Krzysztof Sobolewski

{"title":"Fatty acid composition of triacylglycerols from Wharton's jelly determined by high-performance liquid chromatography","authors":"Lech Romanowicz , Zofia Galewska , Tomasz Gogiel , Stefan Jaworski , Krzysztof Sobolewski","doi":"10.1016/j.jbbm.2007.09.004","DOIUrl":"10.1016/j.jbbm.2007.09.004","url":null,"abstract":"<div><p>The improved method for HPLC determination of fatty acids was proposed. The chromatographic separation of <em>p</em>-bromophenacyl derivatives of fatty acids under a gradient elution was achieved at 40 °C with an RP-18 LiChroCART 5 column and organic mobile phase containing methanol, acetonitrile, water and TEAP buffer pH 5.6. The quantitative determination of those derivatives was performed at 254 nm. Preeclampsia, the most common pregnancy complication, did not affect triacylglycerol content in the umbilical cord Wharton's jelly in comparison to the control material. However, it changed the composition of fatty acids, bound to that lipid class. The method allows the determination of almost all fatty acids forming the investigated neutral lipid class, contained in a solid tissue sample. The use of TEAP buffer excluded precipitation and flow stoppage in the HPLC system. The method reduced time and costs and might be useful for all other lipid classes and different tissues.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 973-977"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jbbm.2007.09.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27026286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

Enantiorecognition of triiodothyronine and thyroxine enantiomers using different chiral selectors by HPLC and micro-HPLC 不同手性选择剂对三碘甲状腺原氨酸和甲状腺素对映体的高效液相色谱和微高效液相色谱识别

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 DOI: 10.1016/j.jbbm.2007.09.007

Julia Koidl, Heike Hödl, Martin G. Schmid, Bianca Neubauer, Marlene Konrad, Sabine Petschauer, Gerald Gübitz

{"title":"Enantiorecognition of triiodothyronine and thyroxine enantiomers using different chiral selectors by HPLC and micro-HPLC","authors":"Julia Koidl, Heike Hödl, Martin G. Schmid, Bianca Neubauer, Marlene Konrad, Sabine Petschauer, Gerald Gübitz","doi":"10.1016/j.jbbm.2007.09.007","DOIUrl":"10.1016/j.jbbm.2007.09.007","url":null,"abstract":"<div><p>This paper deals with the chiral separation of triiodothyronine (T<sub>3</sub>) and thyroxine (T<sub>4</sub>) by HPLC and micro-HPLC. The separation of T<sub>3</sub> and T<sub>4</sub> is of great pharmaceutical and clinical interest, since the enantiomers exhibit different pharmacological activities. The HPLC measurements were performed on a chiral stationary ligand-exchange phase using <span>l</span>-4-hydroxyproline bonded via 3-glycidoxypropyltrimethoxysilane to silica gel as a selector. Also a chiral teicoplanin (Chirobiotic ™®) phase was used.</p><p>In micro-HPLC the chiral separation behaviour of <span>l</span>-4-hydroxyproline, and of the macrocyclic antibiotics teicoplanin and teicoplanin aglycone was investigated for the enantioseparation of T<sub>3</sub> and T<sub>4</sub>. <span>l</span>-4-Hydroxyproline was bonded to 3 μm and the glycopeptide antibiotics were bonded to 3.5 μm silica gel and separations were accomplished by microbore HPLC columns (10 cm×1 mm I.D.). With both techniques and all chiral selectors investigated T<sub>3</sub> and T<sub>4</sub> were baseline resolved. micro-HPLC was found to be superior to analytical HPLC with respect to low consumption of packing material, mobile phase and analyte.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 1254-1260"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jbbm.2007.09.007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41012945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

A method to increase the bioactivity of plasmid DNA by heat treatment 一种通过热处理提高质粒DNA生物活性的方法

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 DOI: 10.1016/j.jprot.2008.01.013

Sen Hou, Kun Yang, Ze Liu, Xi-Zeng Feng

{"title":"A method to increase the bioactivity of plasmid DNA by heat treatment","authors":"Sen Hou, Kun Yang, Ze Liu, Xi-Zeng Feng","doi":"10.1016/j.jprot.2008.01.013","DOIUrl":"10.1016/j.jprot.2008.01.013","url":null,"abstract":"<div><p>A method to increase the bioactivity of plasmid DNA by heat treatment has been developed. The structure of the heat treated plasmid DNA was investigated by electrophoresis assay and atomic force microscope (AFM) observation. Electrophoresis assay showed that the heat treated DNA consisted of three components: the supercoiled DNA (component I), the open circular DNA (component II) and the heat denatured DNA component. The bioactivity of the heat treated plasmid DNA was investigated by both DNA condensation experiments and gene transfection experiment with mammal cells. DNA condensation experiments showed that the heat denatured DNA component owned higher sensitivity to spermidine and polyethylenimine (PEI) than component I and component II DNA. Gene transfection experiment with PEI indicated that the heat treated DNA had higher gene transfection efficiency than untreated DNA. Our experiment not only shows an effective approach to increase the bioactivity of plasmid DNA but also leads a way to improve the bioactivity of DNA by physically modifying their structure.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 1066-1072"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jprot.2008.01.013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27328280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

A steered molecular dynamics method with direction optimization and its applications on ligand molecule dissociation 方向优化导向分子动力学方法及其在配体分子解离中的应用

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 DOI: 10.1016/j.jbbm.2007.10.006

Xinli Liu , Xicheng Wang , Huangliang Jiang

引用次数: 18