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Sample records for biochemical chromogenic assays

  1. Evaluation of Factor Xa-Specific Chromogenic Substrate Assays and the Determination of Pharmacokinetics of Fondaparinux.

    Science.gov (United States)

    Yuri, Maiko; Tabe, Yoko; Tsuchiya, Koji; Sadatsuki, Ryo; Aoki, Jun; Horii, Takashi; Iba, Toshiaki; Ohsaka, Akimichi

    2016-07-01

    Fondaparinux (FPX), a synthesized factor Xa inhibitor, is one of the most popular anticoagulants for the prevention of postoperative venous thromboembolism (VTE). Although routine monitoring is not required, the bleeding adverse events cannot be neglected, and the measurement of anti-Xa activity is expected to be monitored. The primary purpose of this study is to evaluate the performances of 2 chromogenic assays for the detection of anti-Xa activity. Furthermore, the pharmacokinetics of FPX was examined using chromogenic assays. Anti-Xa activity was measured using 2 FPX-based chromogenic substrates (S2222 and STA-Liquid Anti-Xa). The reproducibility, detection limits, linearity, and correlations between the substrates were examined using normal plasma doped with low and high concentrations of FPX formulation. In addition, anti-Xa activity in 235 clinical samples from 164 cases treated was measured, and the pharmacokinetics of FPX was evaluated. Both of the tested substrates were capable of accurately measuring the anti-Xa activity of FPX, with a lower limit of 0.05 μg/mL and a coefficient of variation of less than 10%. The repeated administration of FPX induced a gradual but significant increase in the anti-Xa activity, which was negatively correlated with body weight and estimated glomerular filtration rate. No significant correlation between the anti-Xa activity and the occurrence of postoperative VTE or bleeding event was observed. Anti-Xa activity can be successfully determined using 2 chromogenic assays and automated biochemical analyzers. The clinical significance of anti-Xa activity monitoring should be examined in the future study. PMID:26177660

  2. Method validation and clinical utility of chromogenic factor VIII assay compared to one-stage assay.

    Science.gov (United States)

    Gouws, Wilmare; Botha, Elsabie; Visser, Adele

    2014-01-01

    The chromogenic FVIII assay is currently considered the gold standard for quantitation of factor VIII levels in both haemophilia A patients and as part of screening for thrombophilia. A method validation and evaluation of clinical utility within a routine diagnostic laboratory was undertaken by comparing the currently used one-stage assay to a commercially available chromogenic assay (Siemens, Johannesburg, South Africa). In total, 60 samples were included in this study to encompass the whole diagnostic range of the assay. Both low and high values showed very good correlation on linear regression analysis with correlation coeffients of 0.949 and 0.888 respectively. However, the lower detection limit of the Siemens Chromogenic assay was 1.5 IU/dL rendering it impossible to utilize in the setting of classifying a haemophilia A patient in terms of disease severity. Although the Siemens FVIII chromogenic assay shows excellent correlation to the currently used one-stage assay, the relatively high detection limit restrict implementation as a stand-alone assay in a routine diagnostic laboratory. PMID:23504571

  3. Isolation of Cronobacter spp. (formerly Enterobacter sakazakii from infant food, herbs and environmental samples and the subsequent identification and confirmation of the isolates using biochemical, chromogenic assays, PCR and 16S rRNA sequencing

    Directory of Open Access Journals (Sweden)

    Samara Nawal A

    2009-10-01

    Full Text Available Abstract Background Cronobacter spp. (formerly Enterobacter sakazakii, are a group of Gram-negative pathogens that have been implicated as causative agents of meningitis and necrotizing enterocolitis in infants. The pathogens are linked to infant formula; however, they have also been isolated from a wide range of foods and environmental samples. Results In this study, 233 samples of food, infant formula and environment were screened for the presence of Cronobacter spp. in an attempt to find its source. Twenty nine strains were isolated from samples of spices, herbs, infant foods, and dust obtained from household vacuum cleaners. Among the 76 samples of infant food, infant formula, milk powder and non-milk dairy products tested, only one sample of infant food contained Cronobacter spp. (1.4%. The other Cronobacter spp. isolates recovered include two from household vacuum dust, and 26 from 67 samples of herbs and spices. Among the food categories analyzed, herbs and spices harbored the highest number of isolates, indicating plants as a possible reservoir of this pathogen. Initial screening with API 20E test strips yielded 42 presumptive isolates. Further characterization using 3 chromogenic media (α-MUG, DFI and EsPM and 8 sets of PCR primers detecting ITS (internal transcribed spacer sequences, 16S rRNA, zpx, gluA, gluB, OmpA genes followed by nucleotide sequencing of some PCR amplicons did not confirm the identity of all the isolates as none of the methods proved to be free of both false positives or false negatives. The final confirmation step was done by 16S rRNA sequence analysis identifying only 29 of the 42 isolates as Cronobacter spp. Conclusion Our studies showed that Cronobacter spp. are highly diverse and share many phenotypic traits with other Enterobacteriaceae members highlighting the need to use several methods to confirm the identity of this pathogen. None of the biochemical, chromogenic or PCR primers proved to be a reliable

  4. Examination of chromogenic and fluorogenic substrates in solid-phase enzyme linked immunosorbent assays (ELISA)

    International Nuclear Information System (INIS)

    Fluorogenic and chromogenic substrates were used in direct and trapping enzyme linked immunosorbent assays for the detection of mouse IgG and foot and mouth disease virus (FMDV). The detection limits for both antigens were compared, using different combinations of enzymes and substrates. Various times and concentrations of chemicals were used to obtain maximum sensitivity for both systems. Similar sensitivities were found using fluorogenic and chromogenic substrates. Tetramethyl benzidine substrate for horse radish peroxidase enzyme conjugates was found to attain the highest sensitivity levels for chromogenic assays (0.12 ng IgG/ml and 1.0 ng/ml FMDV respectively), after 10 min incubation. Of the two fluorogenic enzyme/substrates studied, B-galactosidase was the most sensitive but required extended incubation times (2-3 h) as compared with chromogenic systems. Special microplates for fluoro-immunoassay were compared with conventional microplates and no advantage was found to justify their use. An alkaline phosphatase anti-guinea pig conjugate was used to confirm the equivalence of fluorogenic and chromogenic substrates in terms of sensitivity. A comparison of the amount of signal generated using various concentrations of enzyme in the absence of antigen was made for two different alkaline phosphatase conjugates to obtain theoretical sensitivity limits. One possible advantage of fluorogenic substrates is that high binding ratio can improve the confidence in discrimination of positive results. (author). 3 refs, 6 figs, 5 tabs

  5. Chromogenic nitrophenolate-based substrates for light-driven hybrid P450 BM3 enzyme assay.

    Science.gov (United States)

    Lam, Quan; Cortez, Alejandro; Nguyen, Thanh Truc; Kato, Mallory; Cheruzel, Lionel

    2016-05-01

    The incorporation of a p-nitrophenoxy moiety in substrates has enabled the development of colorimetric assays to rapidly screen for O-demethylation activity of P450 enzymes. For the light-driven hybrid P450 BM3 enzymes, where a Ru(II) photosensitizer powers the enzyme upon visible light irradiation, we have investigated a family of p-nitrophenoxy derivatives as useful chromogenic substrates compatible with the light-driven approach. The validation of this assay and its adaptability to a 96-well plate format will enable the screening of the next generation of hybrid P450 BM3 enzymes towards C-H bond functionalization of non-natural substrates. PMID:26712653

  6. Recombinant to modified factor VIII and factor IX - chromogenic and one-stage assays issues.

    Science.gov (United States)

    Kitchen, S; Kershaw, G; Tiefenbacher, S

    2016-07-01

    The recent development of modified recombinant factor VIII (FVIII) and factor IX (FIX) therapeutic products with extended half-lives will create challenges for the haemostasis laboratory in obtaining recovery estimates of these products in clinical samples using existing assays. The new long-acting therapeutic concentrates contain molecular modifications of Fc fusion, site-specific of polyethylene glycol or albumin fusion. The optimum methods for monitoring each new product will need to be assessed individually and laboratories should select an assay which gives similar results to the assay used to assign potency to the product in question. For some extended half-life FVIII and FIX products some one stage assays are entirely unsuitable for monitoring purposes. For most products and assay reagents studied so far, and reviewed in this manuscript, chromogenic FVIII or FIX assays can be safely used with conventional plasma standards. If one stage assays are used then they should be performed using carefully selected reagents/methods which have been shown to recover activity close to the labelled potency for the specific product being monitored. PMID:27405680

  7. Chromogenic assay for the prothrombin activator ecarin from the venom of the saw-scaled viper (Echis carinatus).

    Science.gov (United States)

    Stocker, K; Fischer, H; Brogli, M

    1986-01-01

    Ecarin, by limited proteolysis and subsequent autocatalytic reactions, causes the conversion of prothrombin into three products with amidolytic activity: meizothrombin, meizothrombin 1 and lpha-thrombin. Ecarin action may be abolished by ethylenediaminetetraacetic acid and the activity of alpha-thrombin can, with a high degree of selectivity, be inhibited by heparin. Thus, ecarin potency may be assayed by measuring the meizothrombin activity generated by ecarin action on human plasma in the presence of heparin. The chromogenic substrate Tosyl-glycyl-L-prolyl-L-arginine-p-nitroanilide (Chromozym TH) is used in this assay. PMID:3082039

  8. Chromogenic platform based on recombinant Drosophila melanogaster acetylcholinesterase for visible unidirectional assay of organophosphate and carbamate insecticide residues

    International Nuclear Information System (INIS)

    Highlight: ► A visible chromogenic platform for rapid analysis of OP and CM insecticide residues was developed. ► The assay has the capabilities of both qualitative measurement and quantitative analysis. ► The sensitivity, capabilities of resisting interferences and storage stability were desirable. ► Matrix effects were acceptable and detection performance was satisfactory in real application. - Abstract: In this study we propose a chromogenic platform for rapid analysis of organophosphate (OP) and carbamate (CM) insecticide residues, based on recombinant Drosophila melanogaster acetylcholinesterase (R-DmAChE) as enzyme and indoxyl acetate as substrate. The visible chromogenic strip had the advantages identical to those of commonly used lateral flow assays (LFAs) with utmost simplicity in sample loading and result observation. After optimization, depending on the color intensity (CI) values, the well-established assay has the capabilities of both qualitative measurement via naked eyes and quantitative analysis by colorimetric reader with the desirable IC50 values against the tested six insecticides (0.06 μg mL−1 of carbofuran, 0.28 μg mL−1 of methomyl, 0.03 μg mL−1 of dichlorvos, 31.6 μg mL−1 of methamidophos, 2.0 μg mL−1 of monocrotophos, 6.3 μg mL−1 of omethoate). Acceptable matrix effects and satisfactory detection performance were confirmed by in-parallel LC–MS/MS analysis in different vegetable varieties at various spiked levels of 10−3 to 101 μg g−1. Overall, the testified suitability and applicability of this novel platform meet the requirements for practical use in food safety management and environmental monitoring, especially in the developing world.

  9. Chromogenic platform based on recombinant Drosophila melanogaster acetylcholinesterase for visible unidirectional assay of organophosphate and carbamate insecticide residues

    Energy Technology Data Exchange (ETDEWEB)

    Han Zheng [Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, 1018 Jinqi Road, Shanghai 201403 (China); Chi Chensen [School of Life Science and Biotechnology, Bor Luh Food Safety Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Bai Bing; Liu Gang; Rao Qinxiong [Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, 1018 Jinqi Road, Shanghai 201403 (China); Peng Shaojie [Institute of Shanghai Food and Drug Supervision, 615 Liuzhou Road, Shanghai 200233 (China); Liu Hong [Shanghai Municipal Center for Disease Control and Prevention, 1380 Zhongshan West Road, Shanghai 200336 (China); Zhao Zhihui [Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, 1018 Jinqi Road, Shanghai 201403 (China); Zhang Dabing [School of Life Science and Biotechnology, Bor Luh Food Safety Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Wu Aibo, E-mail: wuaibo@saas.sh.cn [Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, 1018 Jinqi Road, Shanghai 201403 (China)

    2012-03-30

    Highlight: Black-Right-Pointing-Pointer A visible chromogenic platform for rapid analysis of OP and CM insecticide residues was developed. Black-Right-Pointing-Pointer The assay has the capabilities of both qualitative measurement and quantitative analysis. Black-Right-Pointing-Pointer The sensitivity, capabilities of resisting interferences and storage stability were desirable. Black-Right-Pointing-Pointer Matrix effects were acceptable and detection performance was satisfactory in real application. - Abstract: In this study we propose a chromogenic platform for rapid analysis of organophosphate (OP) and carbamate (CM) insecticide residues, based on recombinant Drosophila melanogaster acetylcholinesterase (R-DmAChE) as enzyme and indoxyl acetate as substrate. The visible chromogenic strip had the advantages identical to those of commonly used lateral flow assays (LFAs) with utmost simplicity in sample loading and result observation. After optimization, depending on the color intensity (CI) values, the well-established assay has the capabilities of both qualitative measurement via naked eyes and quantitative analysis by colorimetric reader with the desirable IC{sub 50} values against the tested six insecticides (0.06 {mu}g mL{sup -1} of carbofuran, 0.28 {mu}g mL{sup -1} of methomyl, 0.03 {mu}g mL{sup -1} of dichlorvos, 31.6 {mu}g mL{sup -1} of methamidophos, 2.0 {mu}g mL{sup -1} of monocrotophos, 6.3 {mu}g mL{sup -1} of omethoate). Acceptable matrix effects and satisfactory detection performance were confirmed by in-parallel LC-MS/MS analysis in different vegetable varieties at various spiked levels of 10{sup -3} to 10{sup 1} {mu}g g{sup -1}. Overall, the testified suitability and applicability of this novel platform meet the requirements for practical use in food safety management and environmental monitoring, especially in the developing world.

  10. Effect of ethanol in BET assay performed by kinetic chromogenic method for (18F) radiopharmaceuticals other than (18F) FDG

    International Nuclear Information System (INIS)

    Full text: In recent years, several (18F) labeled radiopharmaceuticals other than 2-(18F)fluoro-2-deoxy-D-glucose have become increasingly important for molecular imaging studies in oncology, and a rapid BET assay is essential to quantify the bacterial endotoxin that may be present in such radiopharmaceutical preparations, prior to use in patients. The radiochemical synthesis of (18F) labelled radiopharmaceuticals like 3'-Deoxy-3'-(18F)fluorothymidine ((18F)FLT), (18F) fluoroazomycinarabinoside ((18F)FAZA) etc is based on use of SEP-PAK cartridge for isolation and purification instead of HPLC purification and requires 15% ethanolic water as elution solvent. BET assay for these radiopharmaceuticals can be routinely performed by Portable Test System (PTS)kinetic reader obtained from Endosafe Inc. The assay is based on kinetic chromogenic method and is known to be inhibited by presence of ethanol. Since all the above mentioned radiopharmaceuticals preparations contains ethanol, the aim of our study was to detect at what ppm/percentage level of ethanol, in final formulation, inhibition in BET assay is observed. The ppm/percentage levels of ethanol in final radiopharmaceutical formulations were detected by gas chromatography. In the present study, the BET Assay for (18F)FDG and (18F)FDG and (18F)FLT was performed at six different dilutions i.e 1:500, 1:200, 1:100, 1:50, 1:20 and 1:10 and all these dilutions were less than the Maximum Valid dilution (MVD). (18F) FDG was chosen as control since the elution solvent for it is 100% water and for all the dilutions mentioned above, the spike recovery was between 50-200%. The CV of negative and positive control samples were found to be 0.0% and less than 10% respectively. However, in case of (18F)FLT, for 1:20 and 1:10 dilutions, the spike recovery was below 50% but coefficient variance of negative and positive control sample were same as (18F)FDG. These results indicate inhibition at 1:20 and 1:10 dilution due to presence of

  11. Advancement in biochemical assays in andrology

    Institute of Scientific and Technical Information of China (English)

    Wolf-BernhardSchill; RaftHenkel

    1999-01-01

    Determination of maikers of sperm function, accessory sex gland secretion and silent male genital tract inflammation is of considerable diagnostic value in the evaluation of male infertility. The introduction of biochemical tests into the analysis of male factor has the advantage that standardized assays with a coefficient of variafion characteristic of clinical chemistry are performed, in contrast to biological test systems with a large variability .Biochemical parameters may be used in clinical practice to evaluate the sperm fertitizing capacity (acrosin, aniline blue,ROS), to characterize male accessory sex gland secretinns (fructose, a-glucosidase, PSA), and to identify men with silent genital tract inflammation (elastase, C'3 complement component, coeruloplasmin, IgA, IgG, ROS). (As/an J Androl 1999 Jun; 1: 45-51)

  12. Click Chemistry-Mediated Nanosensors for Biochemical Assays

    OpenAIRE

    Chen, Yiping; Xianyu, Yunlei; Wu, Jing; Yin, Binfeng; Jiang, Xingyu

    2016-01-01

    Click chemistry combined with functional nanoparticles have drawn increasing attention in biochemical assays because they are promising in developing biosensors with effective signal transformation/amplification and straightforward signal readout for clinical diagnostic assays. In this review, we focus on the latest advances of biochemical assays based on Cu (I)-catalyzed 1, 3-dipolar cycloaddition of azides and alkynes (CuAAC)-mediated nanosensors, as well as the functionalization of nanopro...

  13. Predictive biochemical assays for late radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, P.; Finkelstein, J.N.; Siemann, D.W.; Shapiro, D.L.; Van Houtte, P.; Penney, D.P.

    1986-04-01

    Surfactant precursors or other products of Type II pneumocytes have the potential to be the first biochemical marker for late radiation effects. This is particularly clinically important in the combined modality era because of the frequent occurrence of pneumonitis and pulmonary fibrosis secondary to radiation or chemotherapy. Accordingly, correlative studies have been pursued with the Type II pneumocyte as a beginning point to understand the complex pathophysiology of radiation pneumonitis and fibrosis. From our ultrastructural and biochemical studies, it is evident that Type II pneumocytes are an early target of radiation and the release of surfactant into the alveolus shortly after exposure persists for days and weeks. Through the use of lavaging techniques, alveolar surfactant has been elevated after pulmonary irradiation. In three murine strains and in the rabbit, there is a strong correlation with surfactant release at 7 and/or 28 days in vivo with later lethality in months. In vitro studies using cultures of type II pneumocytes also demonstrate dose response and tolerance factors that are comparable to the in vivo small and large animal diagnostic models. New markers are being developed to serve as a predictive index for later lethal pneumonopathies. With the development of these techniques, the search for early biochemical markers in man has been undertaken. Through the use of biochemical, histological, and ultrastructural techniques, a causal relationship between radiation effects on type II pneumocytes, pulmonary cells, endothelial cells of blood vessels, and their roles in the production of pneumonitis and fibrosis will evolve.

  14. Predictive biochemical assays for late radiation effects

    International Nuclear Information System (INIS)

    Surfactant precursors or other products of Type II pneumocytes have the potential to be the first biochemical marker for late radiation effects. This is particularly clinically important in the combined modality era because of the frequent occurrence of pneumonitis and pulmonary fibrosis secondary to radiation or chemotherapy. Accordingly, correlative studies have been pursued with the Type II pneumocyte as a beginning point to understand the complex pathophysiology of radiation pneumonitis and fibrosis. From our ultrastructural and biochemical studies, it is evident that Type II pneumocytes are an early target of radiation and the release of surfactant into the alveolus shortly after exposure persists for days and weeks. Through the use of lavaging techniques, alveolar surfactant has been elevated after pulmonary irradiation. In three murine strains and in the rabbit, there is a strong correlation with surfactant release at 7 and/or 28 days in vivo with later lethality in months. In vitro studies using cultures of type II pneumocytes also demonstrate dose response and tolerance factors that are comparable to the in vivo small and large animal diagnostic models. New markers are being developed to serve as a predictive index for later lethal pneumonopathies. With the development of these techniques, the search for early biochemical markers in man has been undertaken. Through the use of biochemical, histological, and ultrastructural techniques, a causal relationship between radiation effects on type II pneumocytes, pulmonary cells, endothelial cells of blood vessels, and their roles in the production of pneumonitis and fibrosis will evolve

  15. Automated optical sensing system for biochemical assays

    Science.gov (United States)

    Oroszlan, Peter; Duveneck, Gert L.; Ehrat, Markus; Widmer, H. M.

    1994-03-01

    In this paper, we present a new system called FOBIA that was developed and optimized with respect to automated operation of repetitive assay cycles with regenerable bioaffinity sensors. The reliability and precision of the new system is demonstrated by an application in a competitive assay for the detection of the triazine herbicide Atrazine. Using one sensor in more than 300 repetitive cycles, a signal precision better than 5% was achieved.

  16. Click Chemistry-Mediated Nanosensors for Biochemical Assays

    Science.gov (United States)

    Chen, Yiping; Xianyu, Yunlei; Wu, Jing; Yin, Binfeng; Jiang, Xingyu

    2016-01-01

    Click chemistry combined with functional nanoparticles have drawn increasing attention in biochemical assays because they are promising in developing biosensors with effective signal transformation/amplification and straightforward signal readout for clinical diagnostic assays. In this review, we focus on the latest advances of biochemical assays based on Cu (I)-catalyzed 1, 3-dipolar cycloaddition of azides and alkynes (CuAAC)-mediated nanosensors, as well as the functionalization of nanoprobes based on click chemistry. Nanoprobes including gold nanoparticles, quantum dots, magnetic nanoparticles and carbon nanomaterials are covered. We discuss the advantages of click chemistry-mediated nanosensors for biochemical assays, and give perspectives on the development of click chemistry-mediated approaches for clinical diagnosis and other biomedical applications. PMID:27217831

  17. Use of laminar flow patterning for miniaturised biochemical assays

    DEFF Research Database (Denmark)

    Regenberg, Birgitte; Krühne, Ulrich; Beyer, M.;

    2004-01-01

    Laminar flow in microfluidic chambers was used to construct low (one dimensional) density arrays suitable for miniaturized biochemical assays. By varying the ratio of flows of two guiding streams flanking a sample stream, precise focusing and positioning of the latter was achieved, and reactive...... species carried in the sample stream were deposited on functionalized chip surfaces as discrete 50 mm wide lanes. Using different model systems we have confirmed the method's suitability for qualitative screening and quantification tasks in receptor-ligand assays, recording biotin...

  18. The Fate of HIV-1 Capsid: A Biochemical Assay for HIV-1 Uncoating

    OpenAIRE

    Yang, Yang; Luban, Jeremy; Diaz-Griffero, Felipe

    2014-01-01

    The uncoating process of HIV-1 is a poorly understood process, so the development of a reliable assay to study uncoating is critical for moving the field forward. Here we describe an uncoating assay that currently represents the state-of-the-art biochemical procedure for monitoring uncoating and core stability during infection. This assay is based on the biochemical separation of soluble capsid protein from particulate capsid cores and provides information about the fate of the capsid during ...

  19. The fate of HIV-1 capsid: a biochemical assay for HIV-1 uncoating.

    Science.gov (United States)

    Yang, Yang; Luban, Jeremy; Diaz-Griffero, Felipe

    2014-01-01

    The uncoating process of HIV-1 is a poorly understood process, so the development of a reliable assay to study uncoating is critical for moving the field forward. Here we describe an uncoating assay that currently represents the state-of-the-art biochemical procedure for monitoring uncoating and core stability during infection. This assay is based on the biochemical separation of soluble capsid protein from particulate capsid cores and provides information about the fate of the capsid during infection. PMID:24158811

  20. Biochemical assays for the discovery of TDP1 inhibitors

    OpenAIRE

    Marchand, Christophe; Huang, Shar-yin N.; Dexheimer, Thomas S.; Lea, Wendy A.; Mott, Bryan T.; Chergui, Adel; Naumova, Alena; Stephen, Andrew G.; Rosenthal, Andrew S.; Rai, Ganesha; Murai, Junko; Gao, Rui; Maloney, David J.; Jadhav, Ajit; Jorgensen, William L.

    2014-01-01

    Drug screening against novel targets is warranted to generate biochemical probes and new therapeutic drug leads. Tyrosyl-DNA-phosphodiesterases 1 and 2 (TDP1 and TDP2) are two DNA repair enzymes that have yet to be successfully targeted. TDP1 repairs topoisomerase I-, alkylation-, and chain terminator-induced DNA damage, while TDP2 repairs topoisomerase II-induced DNA damage. Here we report the quantitative high-throughput screening (qHTS) of the NIH Molecular Libraries Small Molecule Reposit...

  1. Antioxidant abilities of human plasma, buckwheat extracts and fractions, and quercetin metabolites in different biochemical assays

    OpenAIRE

    Janisch, Kerstin Maria

    2005-01-01

    Human plasma tested in biochemical assays (ACC/HOCl, ABTS, Sin-1, X/XOD, diaphorase, peroxynitrite, Fenton) achieves different I-values in each assay, indicating different antioxidant properties. When examined closer in four out of these seven assays (ACC/HOCl, ABTS, Sin-1, Fenton), it became obvious that the plasma proteins are the main responsible antioxidants. Only in the Sin-1 and Fenton assay, is the influence of the low-molecular antioxidants visible. The comparison of 25 single-plasma ...

  2. Phenolsulphotransferase in human tissue: radiochemical enzymatic assay and biochemical properties

    International Nuclear Information System (INIS)

    Phenolsulphotransferase (EC 2.8.2.1) (PST) is an important catecholamine and drug metabolizing enzyme. Optimal conditions have been determined for the accurate measurement of PST activity in the human platelet, human renal cortex, and human jejunum with a radiochemical microassay. 3-Methoxy-4-hydroxyphenylglycol (MHPG) and 35S-3'-phosphoadenosine-5'-phosphosulfate (35S-PAPS) were the substrates for the reaction. The apparent Michaelis-Menten (Ksub(m)) values for MHPG with platelet, renal cortex, and jejunum were 1.09, 0.46 and 1.16 mmol/l, respectively. Apparent Ksub(m) values for PAPS in the same tissues were 0.14, 0.13 and 0.21 μmol/l. The pH optimum of the reacton in all three tissues was approximately 6.2-6.8 with three different buffer systems. The coefficients of variation for the assay of platelet, renal cortex, and jejunal activities were 6.2%, 3.4% and 4.4%, respectively. Mean platelet PST activity in blood samples from 75 randomly selected adult subjects was 5.0 +- 1.72 mmol of MHPG sulfate formed per hour per mg of platelet protein (8.3 X 10-5 +- 2.9 X 10-5 μmol min-1 mg-1, mean +- S.D.). There was a 5-fold intersubject variation in platelet PST activity within two standard deviations of the mean value. Experiments in which partially purified human erythrocyte PST was added to platelet, kidney and gut homogenates under these assay conditions provided evidence that endogenous PST inhibitors did not affect the observed enzyme activity. (Auth.)

  3. Acetylcholinesterase in the human erythron. II. Biochemical assay.

    Science.gov (United States)

    Barr, R D; Koekebakker, M; Lawson, A A

    1988-08-01

    Acetylcholinesterase (AChE) is an integral erythrocyte membrane protein. A role for the enzyme in the developing human erythron is being explored. Assays of AchE by the standard Ellman technique overestimate the amount of enzyme by failing to account for the contribution of hemoglobin to the optical density of the reaction mixture. Furthermore, reliance on substrate selection alone for specificity is unsatisfactory. Incorporation of inhibitors of "true" AchE and of pseudocholinesterase confer greater ability to distinguish one enzyme from the other. In our experience, the inhibitor constant (Kl) for edrophonium, which is highly specific for AChE, is approximately 5 x 10(-5) M against adult human erythrocytes that contain significantly more total cholinesterase activity than do erythrocytes from umbilical cord blood. This consists of both "true" and "pseudo" enzyme, the former predominating and accounting for 0.75-1.65 (mean 1.02, median 0.87) femtomoles of substrate hydrolysed per min per cell in adult blood, with values of 0.15-1.04 (mean 0.71, median 0.73) obtained on cord blood. Moreover, the enzyme activity in neonatal erythrocytes has a rather different inhibitor profile from that of adult cells. AChE was also demonstrated in fresh (ALL) and cultured (K562 and HL60) human leukemic cells, as well as in primitive granulocyte-macrophage and erythroid cells cloned from normal human bone marrow. In the erythroid colonies the enzyme activity was 0-3.76 (mean 1.20, median 0.76) femtomoles per min per cell, apparently the first successful measurement of AChE in such cells. PMID:3166338

  4. Immunohistochemical and biochemical assay of versican in human sound predentine/dentine matrix

    OpenAIRE

    Ruggeri, A.; G Orsini; Mazzoni, A.; Nato, F; Papa, V.; Piccirilli, M.; Putignano, A; Mazzotti, G.; De Stefano Dorigo, E.; Breschi, L.

    2009-01-01

    Aim of this study was to investigate the distribution of versican proteoglycan within the human dentine organic matrix by means of a correlative immunohistochemical analysis with field emission in-lens scanning electron microscope (FEI-SEM), transmission electron microscope (TEM), fluorescence microscope (FM) and biochemical assay. Specimens containing dentine and predentine were obtained from non carious human teeth and divided in three groups: 1) FEI-SEM group: sections were exposed to a pr...

  5. Ultraminiaturized assay for rapid, low cost detection and quantification of clinical and biochemical samples.

    Science.gov (United States)

    Parween, Shahila; Nahar, Pradip

    2016-04-01

    Herein, we report a simple, sensitive, rapid and low-cost ultraminiaturized assay technique for quantitative detection of 1 μl of clinical or biochemical sample on a novel ultraminiaturized assay plate (UAP). UAP is prepared by making tiny cavities on a polypropylene sheet. As UAP cannot immobilize a biomolecule through absorption, we have activated the tiny cavities of UAP by 1-fluoro-2-nitro-4-azidobenzene in a photochemical reaction. Activated UAP (AUAP) can covalently immobilize any biomolecule having an active nucleophilic group such as amino group. Efficacy of AUAP is demonstrated by detecting human IgE, antibody of hepatitis C virus core antigen and oligonucleotides. Quantification is performed by capturing the image of the colored assay solution and digitally quantifying the image by color saturation without using costly NanoDrop spectrophotometer. Image - based detection of human IgE and an oligonucleotide shows an excellent correlation with absorbance - based assay (recorded in a NanoDrop spectrophotometer); it is validated by Pearson's product-moment correlation with correlation coefficient of r = 0.9545088 and r = 0.9947444 respectively. AUAP is further checked by detecting hepatitis C virus Ab where strong correlation of color saturation with absorbance with respect to concentration is observed. Ultraminiaturized assay successfully detects target oligonucleotides by perfectly hybridizing with their respective complementary oligonucleotide probes but not with a random oligonucleotide. Ultraminiaturized assay technique has substantially reduced the requirement of reagents by 100 times and assay timing by 50 times making it a potential alternative to conventional method. PMID:26973054

  6. Dynamic colour of chromogenic materials

    OpenAIRE

    Klanjšek Gunde, Marta

    2010-01-01

    Chromogenic materials change colour due to some stimulus. They are increasingly applied in the so-called smart applications where the change of colour is used. Two examples of such applications are presented, electrochromic windows and thermochromic printing inks. Active component in many switchable smart windows is a thin layer of electrochromic material. Most frequently WO3 is applied, which changes reversibly from colourless to deep blue state, when a constant current is provided in one or...

  7. Determining the functional significance of mismatch repair gene missense variants using biochemical and cellular assays

    DEFF Research Database (Denmark)

    Heinen, Christopher D; Juel Rasmussen, Lene

    2012-01-01

    provided an important experimental tool for studying the functional consequences of VUS. However, beyond this repair assay, a number of other experimental methods have been developed that allow us to test the effect of a VUS on discrete biochemical steps or other aspects of MMR function. Here, we describe......ABSTRACT: With the discovery that the hereditary cancer susceptibility disease Lynch syndrome (LS) is caused by deleterious germline mutations in the DNA mismatch repair (MMR) genes nearly 20 years ago, genetic testing can now be used to diagnose this disorder in patients. A definitive diagnosis of...... LS can direct how clinicians manage the disease as well as prevent future cancers for the patient and their families. A challenge emerges, however, when a germline missense variant is identified in a MMR gene in a suspected LS patient. The significance of a single amino acid change in these large...

  8. Liver iron estimation in β-thalassaemia: Comparison of MRI biochemical assay and histological grading

    International Nuclear Information System (INIS)

    AIMS: The aims of the study were to compare the efficacy of magnetic resonance imaging (MRI), biochemical assay and histological grading in estimating liver iron content, and to evaluate the value of liver to muscle signal intensity ratio (L/M ratio) on spin-echo T1-weighted images in this role. MATERIALS AND METHODS: Thirty-nine homozygous β -thalassaemics had their L/M ratio measured on MRI, followed by ultrasound-guided liver biopsies with histological grading of iron storage and biochemical quantification of liver iron concentration (LIC-b) using atomic absorption spectrophotometry. RESULTS: A significant difference in L/M ratios between the four grades of iron storage on histology was observed (P 15 mg/g. A L/M ratio of > 0.8 predicts a histological iron storage grading of 0 or 1 with a 100% sensitivity and 74% specificity. CONCLUSION: L/M ratio on MRI is of value as a non-invasive alternative to repeated liver biopsies for estimating liver iron content at clinically important thresholds. Chan, Y.L. et al. (2001)

  9. Comparison of two chromogenic media and evaluation of two molecular based identification systems for Enterobacter sakazakii detection

    Directory of Open Access Journals (Sweden)

    Diep Benjamin

    2006-02-01

    Full Text Available Abstract Background Enterobacter sakazakii is a foodborne pathogen that has been associated with sporadic cases and outbreaks causing meningitis, necrotizing enterocolitis and sepsis especially in neonates. The current FDA detection method includes two enrichment steps, the subculturing of the second enrichment broth on a selective agar (VRBG, a further subculturing of selected grown colonies on TSA and the subsequent biochemical identification of yellow-pigmented colonies by API20E. However, there is a strong need for simplified methods for isolation and identification of E. sakazakii. In this study, two chromogenic media, which allow to indicate presumptive E. sakazakii colonies by the alpha glucosidase activity, as well as a newly developed 1,6-alpha-glucosidase based conventional PCR assay and a rRNA oligonucleotide probe based commercial test system for identification of presumptive E. sakazakii were evaluated on 98 target and non-target strains. The methods were compared with respect to specificity aspects. Results A total of 75 presumptive E. sakazakii and 23 non-target strains were analysed by using chromogenic media, alpha-glucosidase based PCR assay, and the VIT assay. For most presumptive E. sakazakii strains on the chromogenic media, the PCR and VIT assay confirmed the identification. However, for a number of presumptive E. sakazakii isolates from fruit powder, the alpha-glucosidase PCR and VIT assay did not correspond to the typical E. sakazakii colonies on DFI and ESIA. Further characterization by API32E identification, phylogenetic analysis of partial 16S rRNA sequences and ribotyping strongly suggested, that these strains did not belong to the species E. sakazakii. The newly developed alpha-glucosidase based PCR assay as well as the commercially available VIT Enterobacter sakazakii identification test showed an excellent correlation with the 16S rRNA data, and are thus well suited for identification of E. sakazakii. Conclusion

  10. Liver iron estimation in {beta}-thalassaemia: Comparison of MRI biochemical assay and histological grading

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Y.L.; Li, C.K.; Lam, C.W.K.; Yu, S.C.H.; Chik, K.W.; To, K.F.; Yeung, D.K.W.; Howard, R.; Yuen, P.M.P

    2001-11-01

    AIMS: The aims of the study were to compare the efficacy of magnetic resonance imaging (MRI), biochemical assay and histological grading in estimating liver iron content, and to evaluate the value of liver to muscle signal intensity ratio (L/M ratio) on spin-echo T1-weighted images in this role. MATERIALS AND METHODS: Thirty-nine homozygous {beta} -thalassaemics had their L/M ratio measured on MRI, followed by ultrasound-guided liver biopsies with histological grading of iron storage and biochemical quantification of liver iron concentration (LIC-b) using atomic absorption spectrophotometry. RESULTS: A significant difference in L/M ratios between the four grades of iron storage on histology was observed (P < 0.001). The coefficient of correlation was -0.67 between L/M ratio and LIC-b ranging from 2 to 21.6 mg/g dry weight. Specific values of L/M ratio reliably reflected liver iron content at clinically important levels. A L/M ratio of < 0.6 has 86% sensitivity and 100% specificity in the prediction of grade 3 or 4 iron storage histologically and 81% sensitivity and 81% specificity in predicting LIC-b > 15 mg/g. A L/M ratio of > 0.8 predicts a histological iron storage grading of 0 or 1 with a 100% sensitivity and 74% specificity. CONCLUSION: L/M ratio on MRI is of value as a non-invasive alternative to repeated liver biopsies for estimating liver iron content at clinically important thresholds. Chan, Y.L. et al. (2001)

  11. Interaction of ZnO nanoparticles with microbes--a physio and biochemical assay.

    Science.gov (United States)

    Padmavathy, Nagarajan; Vijayaraghavan, Rajagopalan

    2011-12-01

    The antibacterial activity of ZnO nanoparticles (nano ZnO) on various microorganisms has been investigated in this study and acting mechanism is proposed for E. coli a model organism by analyzing the growth, permeability and morphology of the bacterial cells. The experimental results indicated 1 mmoL (81.4 microg) nano ZnO could completely inhibit the growth of 10(7) cfu/mL bacterial cells in liquid Luria-Betrani medium. In the biochemical study, it has been observed that, nano ZnO resulted in the leakage of proteins. Chemiluminescence assay proved the generation of the reactive oxygen species into active state. When the cells of E. coli were exposed to nano ZnO, many pits were observed in bacterial cells by TEM and Fluorescence microscopy and the cells were found to be fragmentary. Released zinc ion from has been monitored by AAS. It suggested that nano ZnO is able to destroy the permeability of the bacterial membranes. Our study demonstrated that nano ZnO damages the structure of bacterial cell membrane and depressed the activity of some membranous enzymes by ROS production which caused E. coli bacteria to die eventually. PMID:22416581

  12. Design, Synthesis, and Use of MMP-2 Inhibitor-Conjugated Quantum Dots in Functional Biochemical Assays.

    Science.gov (United States)

    Bourguet, Erika; Brazhnik, Kristina; Sukhanova, Alyona; Moroy, Gautier; Brassart-Pasco, Sylvie; Martin, Anne-Pascaline; Villena, Isabelle; Bellon, Georges; Sapi, Janos; Nabiev, Igor

    2016-04-20

    The development of chemically designed matrix metalloprotease (MMP) inhibitors has advanced the understanding of the roles of MMPs in different diseases. Most MMP probes designed are fluorogenic substrates, often suffering from photo- and chemical instability and providing a fluorescence signal of moderate intensity, which is difficult to detect and analyze when dealing with crude biological samples. Here, an inhibitor that inhibits MMP-2 more selectively than Galardin has been synthesized and used for enzyme labeling and detection of the MMP-2 activity. A complete MMP-2 recognition complex consisting of a biotinylated MMP inhibitor tagged with the streptavidin-quantum dot (QD) conjugate has been prepared. This recognition complex, which is characterized by a narrow fluorescence emission spectrum, long fluorescence lifetime, and negligible photobleaching, has been demonstrated to specifically detect MMP-2 in in vitro sandwich-type biochemical assays with sensitivities orders of magnitude higher than those of the existing gold standards employing organic dyes. The approach developed can be used for specific in vitro visualization and testing of MMP-2 in cells and tissues with sensitivities significantly exceeding those of the best existing fluorogenic techniques. PMID:26930394

  13. Nuclear pore complex assembly studied with a biochemical assay for annulate lamellae formation.

    Science.gov (United States)

    Meier, E; Miller, B R; Forbes, D J

    1995-06-01

    Formation of the nuclear pore is an intricate process involving membrane fusion and the ordered assembly of up to 1,000 pore proteins. As such, the study of pore assembly is not a simple one. Interestingly, annulate lamellae, a cytoplasmic organelle consisting of stacks of flattened membrane cisternae perforated by numerous pore complexes, have been found to form spontaneously in a reconstitution system derived from Xenopus egg extracts, as determined by electron microscopy (Dabauvalle et al., 1991). In this work, a biochemical assay for annulate lamellae (AL) formation was developed and used to study the mechanism of AL assembly in general and the assembly of individual nucleoporins into pore complexes in particular. Upon incubation of Xenopus egg cytosol and membrane vesicles, the nucleoporins nup58, nup60, nup97, nup153, and nup200 initially present in a disassembled form in the cytosol became associated with membranes and were pelletable. The association was time and temperature dependent and could be measured by immunoblotting. Thin-section electron microscopy as well as negative staining confirmed that annulate lamellae were forming coincident with the incorporation of pore proteins into membranes. Homogenization and subsequent flotation of the membrane fraction allowed us to separate a population of dense membranes, containing the integral membrane pore protein gp210 and all other nucleoporins tested, from the bulk of cellular membranes. Electron microscopy indicated that annulate lamellae were enriched in this dense, pore protein-containing fraction. GTP gamma S prevented incorporation of the soluble pore proteins into membranes. To address whether AL form in the absence of N-acetylglucosaminylated pore proteins, AL assembly was carried out in WGA-sepharose-depleted cytosol. Under these conditions, annulate lamellae formed but were altered in appearance. When the membrane fraction containing this altered AL was homogenized and subjected to flotation, the

  14. Alternative Methods for the Detection of Emerging Marine Toxins: Biosensors, Biochemical Assays and Cell-Based Assays

    Directory of Open Access Journals (Sweden)

    Laia Reverté

    2014-11-01

    Full Text Available The emergence of marine toxins in water and seafood may have a considerable impact on public health. Although the tendency in Europe is to consolidate, when possible, official reference methods based on instrumental analysis, the development of alternative or complementary methods providing functional or toxicological information may provide advantages in terms of risk identification, but also low cost, simplicity, ease of use and high-throughput analysis. This article gives an overview of the immunoassays, cell-based assays, receptor-binding assays and biosensors that have been developed for the screening and quantification of emerging marine toxins: palytoxins, ciguatoxins, cyclic imines and tetrodotoxins. Their advantages and limitations are discussed, as well as their possible integration in research and monitoring programs.

  15. Alternative methods for the detection of emerging marine toxins: biosensors, biochemical assays and cell-based assays.

    Science.gov (United States)

    Reverté, Laia; Soliño, Lucía; Carnicer, Olga; Diogène, Jorge; Campàs, Mònica

    2014-12-01

    The emergence of marine toxins in water and seafood may have a considerable impact on public health. Although the tendency in Europe is to consolidate, when possible, official reference methods based on instrumental analysis, the development of alternative or complementary methods providing functional or toxicological information may provide advantages in terms of risk identification, but also low cost, simplicity, ease of use and high-throughput analysis. This article gives an overview of the immunoassays, cell-based assays, receptor-binding assays and biosensors that have been developed for the screening and quantification of emerging marine toxins: palytoxins, ciguatoxins, cyclic imines and tetrodotoxins. Their advantages and limitations are discussed, as well as their possible integration in research and monitoring programs. PMID:25431968

  16. A sensitive ferricyanide-mediated biochemical oxygen demand assay for analysis of wastewater treatment plant influents and treated effluents.

    Science.gov (United States)

    Jordan, Mark A; Welsh, David T; John, Richard; Catterall, Kylie; Teasdale, Peter R

    2013-02-01

    Representative and fast monitoring of wastewater influent and effluent biochemical oxygen demand (BOD) is an elusive goal for the wastewater industry and regulatory bodies alike. The present study describes a suitable assay, which incorporates activated sludge as the biocatalyst and ferricyanide as the terminal electron acceptor for respiration. A number of different sludges and sludge treatments were investigated, primarily to improve the sensitivity of the assay. A limit of detection (LOD) (2.1 mg BOD₅ L⁻¹) very similar to that of the standard 5-day BOD₅ method was achieved in 4 h using raw influent sludge that had been cultured overnight as the biocatalyst. Reducing the microbial concentration was the most effective means to improve sensitivity and reduce the contribution of the sludge's endogenous respiration to total ferricyanide-mediated (FM) respiration. A strong and highly significant relationship was found (n = 33; R = 0.96; p treatment plant (WWTP) influent and treated effluent, as well as several grey water samples. The activated sludge FM-BOD assay presented here is an exceptional surrogate method to the standard BOD₅ assay, providing representative, same-day BOD analysis of WWTP samples with a comparable detection limit, a 4-fold greater analytical range and much faster analysis time. The industry appeal of such an assay is tremendous given that ~90% of all BOD₅ analysis is dedicated to measurement of WWTP samples, for which this assay is specifically designed. PMID:23200506

  17. Highly sensitive optofluidic chips for biochemical liquid assay fabricated by 3D femtosecond laser micromachining followed by polymer coating.

    Science.gov (United States)

    Hanada, Yasutaka; Sugioka, Koji; Midorikawa, Katsumi

    2012-10-01

    The demand for increased sensitivity in the concentration analysis of biochemical liquids is a crucial issue in the development of lab on a chip and optofluidic devices. We propose a new design for optofluidic devices for performing highly sensitive biochemical liquid assays. This design consists of a microfluidic channel whose internal walls are coated with a polymer and an optical waveguide embedded in photostructurable glass. The microfluidic channel is first formed by three-dimensional femtosecond laser micromachining. The internal walls of the channel are then coated by the dipping method with a polymer that has a lower refractive index than water. Subsequently, the optical waveguide is integrated with the microfluidic channel. The polymer coating on the internal walls permits the probe light, which is introduced by the optical waveguide, to propagate along the inside of the microfluidic channel. This results in a sufficiently long interaction length between the probe light and a liquid sample in the channel and thus significantly improves the sensitivity of absorption measurements. Using the fabricated optofluidic chips, we analyzed protein in bovine serum albumin to concentrations down to 7.5 mM as well as 200 nM glucose-D. PMID:22814524

  18. Generation and precise control of dynamic biochemical gradients for cellular assays

    CERN Document Server

    Saka, Yasushi; Giuraniuc, Claudiu V

    2016-01-01

    Spatial gradients of diffusible signalling molecules play crucial roles in controlling diverse cellular behaviour such as cell differentiation, tissue patterning and chemotaxis. Here we present a microfluidic platform for cellular assays that can generate and control diffusion-based gradients dynamically. A unique design of the device eliminates cross-flow between the source and sink channels, thereby stabilising gradients by passive diffusion. The platform also enables quick and flexible control of chemical concentration that makes highly dynamic gradients in diffusion chambers. Budding yeast cells cultured in a gradient of a chemical inducer expressed a reporter fluorescence protein in a concentration-dependent manner. This microfluidic platform serves as a versatile prototype applicable to a broad range of biomedical investigations.

  19. Chromogens in Multiple Immunohistochemical Staining Used for Visual Assessment and Spectral Imaging: The Colorful Future

    NARCIS (Netherlands)

    C.M. van der Loos

    2010-01-01

    For the chromogenic visualization of immunohistochemical enzymatic reaction products, only a limited series of different enzymatic activities and chromogens are available. Consequently, combinations of two chromogens for double immunohistochemical staining are even more limited for visual assessment

  20. Zn(OTf)2-catalysed indolylation and pyrrolylation of isatins: Efficient synthesis and biochemical assay of 3,3-di(heteroaryl)oxindoles

    Indian Academy of Sciences (India)

    C Praveen; S Narendiran; P Dheenkumar; P T Perumal

    2013-11-01

    An efficient and cheap synthetic approach to 3,3-di(indolyl)oxindoles and 3,3-di(pyrrolyl) oxindoles has been developed via Zn(OTf)2 catalysed indolylation and pyrrolylation of isatins. A preliminary biochemical assay of the synthesized molecules in rodent models were performed to estimate the serum glutamate oxaloacetate transaminase and malondialdehyde levels.

  1. Exudative epidermitis in pigs caused by toxigenic Staphylococcus chromogenes

    DEFF Research Database (Denmark)

    Andresen, Lars Ole; Ahrens, Peter; Daugaard, Lise;

    2005-01-01

    Staphylococcus chromogenes is closely related to Staphylococcus hyicus, which is recognised as the causative agent of exudative epidermitis (EE) in pigs. S. chromogenes is part of the normal skin flora of pigs, cattle and poultry and has so far been considered non-pathogenic to pigs. A strain of S...

  2. Development and Evaluation of PCR Assays for the Detection of Paenibacillus larvae in Honey Samples: Comparison with Isolation and Biochemical Characterization

    OpenAIRE

    Bakonyi, Tamás; Derakhshifar, Irmgard; Grabensteiner, Elvira; Nowotny, Norbert

    2003-01-01

    PCR assays were developed for the direct detection of Paenibacillus larvae in honey samples and compared with isolation and biochemical characterization procedures. Different primer pairs, designed from the 16S rRNA and the metalloproteinase precursor gene regions, and different DNA extraction methods were tested and compared. The sensitivity of the reactions was evaluated by serial dilutions of DNA extracts obtained from P. larvae cultures. The specificity of the primers was assessed by anal...

  3. Anaerobic digestion of solid waste in RAS: Effect of reactor type on the biochemical acidogenic potential (BAP) and assessment of the biochemical methane potential (BMP) by a batch assay

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Letelier-Gordo, Carlos Octavio; Lund, Ivar

    2015-01-01

    Anaerobic digestion is a way to utilize the potential energy contained in solid waste produced in recirculating aquaculture systems (RASs), either by providing acidogenic products for driving heterotrophic denitrification on site or by directly producing combustive methane. In this study the...... design of an acidogenic continuously stirred reactor tank in a RAS single-sludge denitrification set-up. The biochemical methane potential of the sludge was estimated to 318 ± 29 g CH4 g-1 TVS0 by a batch assay and represented a higher utility of the solid waste when comparing the methane yield with the...... biochemical acidogenic potential of solid waste from juvenile rainbow trout was evaluated by measuring the yield of volatile fatty acids (VFA) during anaerobic digestion by batch or fed-batch reactor operation at hydrolysis time (HT) / hydraulic retention time (HRT) of 1, 5, or 10 days (and for batch...

  4. Quantifying chromogen intensity in immunohistochemistry via reciprocal intensity.

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: David Nguyen ### Abstract Immunohistochemistry is a routine procedure for detecting the expression of biological markers in formalin-fixed and paraffin-embedded tissues. Chromogens, which can appear as different colors (brown, blue, red) under bright field microscopy, are localized in fixed tissues to antigens of interest via an antibody-antigen detection system. The advantage of a chromogen system is that the stained tissue section is permanently fixed, and the staining qual...

  5. MMP Mediated Degradation of Type VI Collagen Is Highly Associated with Liver Fibrosis - Identification and Validation of a Novel Biochemical Marker Assay

    DEFF Research Database (Denmark)

    Veidal, Sanne Skovgard; Karsdal, Morten Asser; Vassiliadis, Efstathios; Nawrocki, Arkadiusz; Larsen, Martin Rossel; Quoc, HTN; Hägglund, Per; Luo, Yunyun; Zheng, Qinlong; Vainer, Ben; Leeming, Diana Julie

    2011-01-01

    Background and Aims: During fibrogenesis, in which excessive remodeling of the extracellular matrix occurs, both the quantity of type VI collagen and levels of matrix metalloproteinases, including MMP-2 and MMP-9, increase significantly. Proteolytic degradation of type VI collagen into small...... fragments, so-called neo-epitopes, may be specific biochemical marker of liver fibrosis. The aim of this study was to develop an ELISA detecting a fragment of type VI collagen generated by MMP-2 and MMP-9, and evaluate this assay in two preclinical models of liver fibrosis. Methods: Mass spectrometric...... analysis of cleaved type VI collagen revealed a large number of protease-generated neo-epitopes. A fragment unique to type VI collagen generated by MMP-2 and MMP-9 was selected for ELISA development. The CO6-MMP assay was evaluated in two rat models of liver fibrosis: bile duct ligation (BDL) and carbon...

  6. Aggregation of polyQ proteins is increased upon yeast aging and affected by Sir2 and Hsf1: novel quantitative biochemical and microscopic assays.

    Directory of Open Access Journals (Sweden)

    Aviv Cohen

    Full Text Available Aging-related neurodegenerative disorders, such as Parkinson's, Alzheimer's and Huntington's diseases, are characterized by accumulation of protein aggregates in distinct neuronal cells that eventually die. In Huntington's disease, the protein huntingtin forms aggregates, and the age of disease onset is inversely correlated to the length of the protein's poly-glutamine tract. Using quantitative assays to estimate microscopically and capture biochemically protein aggregates, here we study in Saccharomyces cerevisiae aging-related aggregation of GFP-tagged, huntingtin-derived proteins with different polyQ lengths. We find that the short 25Q protein never aggregates whereas the long 103Q version always aggregates. However, the mid-size 47Q protein is soluble in young logarithmically growing yeast but aggregates as the yeast cells enter the stationary phase and age, allowing us to plot an "aggregation timeline". This aging-dependent aggregation was associated with increased cytotoxicity. We also show that two aging-related genes, SIR2 and HSF1, affect aggregation of the polyQ proteins. In Δsir2 strain the aging-dependent aggregation of the 47Q protein is aggravated, while overexpression of the transcription factor Hsf1 attenuates aggregation. Thus, the mid-size 47Q protein and our quantitative aggregation assays provide valuable tools to unravel the roles of genes and environmental conditions that affect aging-related aggregation.

  7. Sensing of antipyretic carboxylates by simple chromogenic calix[4]pyrroles.

    Science.gov (United States)

    Nishiyabu, Ryuhei; Anzenbacher, Pavel

    2005-06-15

    We present a simple, two- or three-step method for the synthesis of chromogenic octamethylcalix[4]pyrrole-based (OMCP) sensors for anions. Electrophilic aromatic substitution allows for converting the pyrrole moieties of OMCP into a dye. The formation of a sensor-anion complex results in partial charge transfer and a dramatic change in color. The absorption (UV-vis) and NMR titration experiments show that the chromogenic OMCPs sense anions administered as aqueous solutions, even at high ionic strength ( approximately 0.1 M NaCl), while displaying selectivity for pyrophosphate and carboxylate anions. The experiments with polyurethane sensor films show a strong response for aqueous carboxylates, such as antipyretics naproxen approximately ibuprofen > salicylate, without being biased by bicarbonate or carboxy termini of blood plasma proteins. PMID:15941245

  8. Chromogenic switchable glazing: Towards the development of the smart window

    Energy Technology Data Exchange (ETDEWEB)

    Lampert, C.M.

    1995-06-01

    The science and technology of chromogenic materials for switchable glazings in building applications is discussed. These glazings can be used for dynamic control of solar and visible energy. Currently many researchers and engineers are involved with the development of products in this field. A summary of activities in Japan, Europe, Australia, USA and Canada is made. The activities of the International Energy Agency are included. Both non-electrically activated and electrically activated glazings are discussed. Technologies covered in the first category are photochromics, and thermochromics and thermotropics. A discussion of electrically activated chromogenic glazings includes dispersed liquid crystals, dispersed particles and electrochromics. A selection of device structures and performance characteristics are compared. A discussion of transparent conductors is presented. Technical issues concerning large-area development of smart windows are discussed.

  9. Development of on-fiber optical sensors utilizing chromogenic materials

    Science.gov (United States)

    Yuan, Jianming; El-Sherif, Mahmoud A.

    1999-01-01

    On-fiber optical sensors, designed with chromogenic materials used as the fiber modified cladding, were developed for sensing environmental conditions. The design was based on the previously developed on-fiber devices. It is known that the light propagation characteristics in optical fibers are strongly influenced by the refractive index of the cladding materials. Thus, the idea of the on- fiber devices is based on replacing the passive optical fiber cladding with active or sensitive materials. For example, temperature sensors can be developed by replacing the fiber clad material with thermochromic materials. In this paper, segmented polyurethane-diacetylene copolymer (SPU), was selected as the thermochromic material for temperature sensors applications. This material has unique chromogenic properties as well as the required mechanical behaviors. During UV exposure and heat treatment, the color of the SPU copolymer varies with its refractive index. The boundary condition between core and cladding changes due to the change of the refractive index of the modified cladding material. The method used for the sensor development presented involves three steps: (a) removing the fiber jacket and cladding from a small region, (b) coating the chromogenic materials onto the modified region, and (c) integrating the optical fiber sensor components. The experimental set-up was established to detect the changes of the output signal based on the temperature variations. For the sensor evaluation, real-time measurements were performed under different heating-cooling cycles. Abrupt irreversible changes of the sensor output power were detected during the first heating-cooling cycle. At the same time, color changes of the SPU copolymer were observed in the modified region of the optical fiber. For the next heating-cooling cycles, however, the observed changes were almost completely reversible. This result demonstrates that a low-temperature sensor can be built by utilizing the

  10. A chromogenic test for irradiated oriental fruitfly, Bactrocera philippinensis as quarantine diagnostic kit

    International Nuclear Information System (INIS)

    A biochemical marker of irradiated Oriental fruit fly, Bactrocera philippinensis was isolated and identified in denaturing polyacrylamide gel electrophoresis (SDS-PAGE). The biomarker, Gs-protein, is the biosynthetic product of a radiosensitive gene locus of B philippinensis. The gene seems to be sensitive to radiation even at a low dose of 25 Gy as demonstrated by the loss of the Gs-protein band from SDS-PAGE gel analysis of pupal homogenates and total soluble protein fractions of irradiated larvae. Isolated Gs-protein has a tyrosinase enzyme activity capable of converting tyrosine into an intermediate product, DOPA(Dihydroxilphenolaldanim). It also exhibits the copper-containing character of mushroom tyrosinase as shown in a preliminary TXRF analysis. An apparent molecular weight of 109 kDa was calculated from SDS-PAGE preparation of the Gs-protein with high molecular weight proteins as standards. In particular, a convenient chromogenic test for tyrosinase present in homogenates of fruit fly, B. philippinensis, at different stages of development starting from 2nd instar larva, has been devised to detect whether the fruit fly had been irradiated at a dose of at least 100 Gy. Starting with homogenate material from fruit fly to be tested, a simple such test based on the activity of the tyrosinase enzyme with its substrate produces a positive dark brown to black coloration on a test spot mounted on acetate film containing 2-methyl DOPA. (author)

  11. Changes in the chromogene properties of the betalaine

    International Nuclear Information System (INIS)

    The changes of coloration of four natural extracts were determined in function of the absorbed dose taken place by a source of rays gamma of Cs-137. The used natural extracts contain betalaine that are natural pigments of some plants as the beet root, of there their name. They are also in abundant form in the fruits (tunas) of some species of the Opuntia gender. The extracts were obtained by maceration, starting from beet root and three tuna varieties, and they were stabilized to pH 5.5 the change of coloration you determines in a spectrophotometer ultraviolet/visible by means of the absorbance from the samples to photons of 475, 535 and 600 nm of wave longitude. The absorbance was measured, to different intervals of time. The relationship settled down between the absorbed dose and the chromogene properties of the pigment, with the intention of using it as possible dosemeter. (Author)

  12. Anaerobic digestion of solid waste in RAS: Effect of reactor type on the biochemical acidogenic potential (BAP) and assessment of the biochemical methane potential (BMP) by a batch assay

    OpenAIRE

    Suhr, Karin Isabel; Letelier-Gordo, Carlos Octavio; Lund, Ivar

    2015-01-01

    Anaerobic digestion is a way to utilize the potential energy contained in solid waste produced in recirculating aquaculture systems (RASs), either by providing acidogenic products for driving heterotrophic denitrification on site or by directly producing combustive methane. In this study the biochemical acidogenic potential of solid waste from juvenile rainbow trout was evaluated bymeasuring the yield of volatile fatty acids (VFA) during anaerobic digestion by batch or fed-batch reactor opera...

  13. Proof of concept of using chromogenic arrays as a tool to identify blue cheese varieties.

    Science.gov (United States)

    Zaragozá, Patricia; Ros-Lis, José V; Vivancos, José-Luis; Martínez-Máñez, Ramón

    2015-04-01

    A new chromogenic array for the identification and classification of blue cheeses has been developed. It is based on the response of a chromogenic array composed of five sensing materials prepared by the incorporation of pH indicators to MCM-41 and alumina. Four blue cheeses were tested: Roquefort, Blue Stilton, blue cheese with leaves and blue cheese spread. The colour modulations of the chromogenic array were processed by the principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). The statistical PCA analysis showed different responses to each cheese. PLS-DA models were developed by incorporating the data measured at diverse times, and this approach allowed us to obtain a perfect classification of all five cheeses in 5.5h. The results suggest that chromogenic arrays and optoelectronic noses can be a suitable approach to develop simple systems to classify blue cheeses and of potential use for the detection of food fraud. PMID:25442626

  14. Development of a microfluidic confocal fluorescence detection system for the hyphenation of nano-LC to on-line biochemical assays

    OpenAIRE

    Heus, F.; Giera, M.A.; Kloe, de, G.E.; Iperen, van, C.; Buijs, J.B.; Nahar, T.T.; Smit, A B; Lingeman, H.; Esch, van, Joep; Niessen, W.M.A.; Irth, H.; Kool, J.

    2010-01-01

    One way to profile complex mixtures for receptor affinity is to couple liquid chromatography (LC) on-line to biochemical detection (BCD). A drawback of this hyphenated screening approach is the relatively high consumption of sample, receptor protein and (fluorescently labeled) tracer ligand. Here, we worked toward minimization of sample and reagent consumption, by coupling nano-LC on-line to a light-emitting diode (LED) based capillary confocal fluorescence detection system capable of on-line...

  15. Chromogene properties of the betalains before gamma photons

    International Nuclear Information System (INIS)

    The coloration changes of four natural extracts in function of the absorbed dose produced by a gamma rays source of 137Cs have been studied. The natural extracts were obtained of tuna varieties that contain betalains that are natural pigments of some plants as the beet of where is derived its name. These also are found in abundant form in the fruits of some species of opuntia genus (tunas). The extracts were obtained by maceration, starting from beet and three tuna varieties that were stabilized to a p H of 5.5. The extracts were exposed to the gamma rays of a 137Cs source and the change in the coloration was observed by means of an ultra violet/visible spectrophotometer through of the absorption of the samples to photons of wave longitude 535 nm. The absorption was measured, to different time intervals. The relation between the absorbed dose in Dw water and the chromogene properties of the pigment was established, with the intention of using it as possible dosemeter. (Author)

  16. Local host response following an intramammary challenge with Staphylococcus fleurettii and different strains of Staphylococcus chromogenes in dairy heifers.

    Science.gov (United States)

    Piccart, Kristine; Verbeke, Joren; De Visscher, Anneleen; Piepers, Sofie; Haesebrouck, Freddy; De Vliegher, Sarne

    2016-01-01

    Coagulase-negative staphylococci (CNS) are a common cause of subclinical mastitis in dairy cattle. The CNS inhabit various ecological habitats, ranging between the environment and the host. In order to obtain a better insight into the host response, an experimental infection was carried out in eight healthy heifers in mid-lactation with three different CNS strains: a Staphylococcus fleurettii strain originating from sawdust bedding, an intramammary Staphylococcus chromogenes strain originating from a persistent intramammary infection (S. chromogenes IM) and a S. chromogenes strain isolated from a heifer's teat apex (S. chromogenes TA). Each heifer was inoculated in the mammary gland with 1.0 × 10(6) colony forming units of each bacterial strain (one strain per udder quarter), whereas the remaining quarter was infused with phosphate-buffered saline. Overall, the CNS evoked a mild local host response. The somatic cell count increased in all S. fleurettii-inoculated quarters, although the strain was eliminated within 12 h. The two S. chromogenes strains were shed in larger numbers for a longer period. Bacterial and somatic cell counts, as well as neutrophil responses, were higher after inoculation with S. chromogenes IM than with S. chromogenes TA. In conclusion, these results suggest that S. chromogenes might be better adapted to the mammary gland than S. fleurettii. Furthermore, not all S. chromogenes strains induce the same local host response. PMID:27176792

  17. Biochemical studies of mouse brain tubulin: colchicine binding (DEAE-cellulose filter) assay and subunits (. cap alpha. and. beta. ) biosynthesis and degradation (in newborn brain)

    Energy Technology Data Exchange (ETDEWEB)

    Tse, Cek-Fyne

    1978-01-01

    A DEAE-cellulose filter assay, measuring (/sup 3/H)colchicine bound to colchicine binding protein (CBP) absorbed on filter discs, has been modified to include lM sucrose in the incubation medium for complexing colchicine to CBP in samples before applying the samples to filter discs (single point assay). Due to the much greater stability of colchicine binding capacity in the presence of lM sucrose, multiple time-point assays and least squares linear regression analysis were not necessary for accurate determination of CBP in hybrid mouse brain at different stages of development. The highest concentrations of CBP were observed in the 160,000g supernatant and pellet of newborn brain homogenate. Further studies of the modified filter assay documented that the assay has an overall counting efficiency of 27.3%, that DEAE-cellulose filters bind and retain all tubulin in the assay samples, and that one molecule of colchicine binds approximately one molecule of tubulin dimer. Therefore, millimoles of colchicine bound per milligram total protein can be used to calculate tubulin content. With this technique tubulin content of brain supernatant was found to be 11.9% for newborn, and 7.15% for 11 month old mice. Quantitative densitometry was also used to measure mouse brain supernatant actin content for these two stages. In vivo synthesis and degradation rates of tubulin ..cap alpha.. and ..beta.. subunits of two day mouse brain 100,000g supernatant were studied after intracerebral injection of (/sup 3/H)leucine. Quantitative changes of the ratio of tritium specific activities of tubulin ..cap alpha.. and ..beta.. subunits with time were determined. The pattern of change was biphasic. During the first phase the ratio decreased; during the second phase the ratio increased continuously. An interpretation consistent with all the data in this study is that the ..cap alpha.. subunit is synthesized at a more rapid rate than the ..beta.. subunit. (ERB)

  18. Biochemical studies of mouse brain tubulin: colchicine binding (DEAE-cellulose filter) assay and subunits (α and β) biosynthesis and degradation (in newborn brain)

    International Nuclear Information System (INIS)

    A DEAE-cellulose filter assay, measuring [3H]colchicine bound to colchicine binding protein (CBP) absorbed on filter discs, has been modified to include lM sucrose in the incubation medium for complexing colchicine to CBP in samples before applying the samples to filter discs (single point assay). Due to the much greater stability of colchicine binding capacity in the presence of lM sucrose, multiple time-point assays and least squares linear regression analysis were not necessary for accurate determination of CBP in hybrid mouse brain at different stages of development. The highest concentrations of CBP were observed in the 160,000g supernatant and pellet of newborn brain homogenate. Further studies of the modified filter assay documented that the assay has an overall counting efficiency of 27.3%, that DEAE-cellulose filters bind and retain all tubulin in the assay samples, and that one molecule of colchicine binds approximately one molecule of tubulin dimer. Therefore, millimoles of colchicine bound per milligram total protein can be used to calculate tubulin content. With this technique tubulin content of brain supernatant was found to be 11.9% for newborn, and 7.15% for 11 month old mice. Quantitative densitometry was also used to measure mouse brain supernatant actin content for these two stages. In vivo synthesis and degradation rates of tubulin α and β subunits of two day mouse brain 100,000g supernatant were studied after intracerebral injection of [3H]leucine. Quantitative changes of the ratio of tritium specific activities of tubulin α and β subunits with time were determined. The pattern of change was biphasic. During the first phase the ratio decreased; during the second phase the ratio increased continuously. An interpretation consistent with all the data in this study is that the α subunit is synthesized at a more rapid rate than the β subunit

  19. Binding of peptides from the N-terminal region of alpha-gliadin to the celiac disease-associated HLA-DQ2 molecule assessed in biochemical and T cell assays

    DEFF Research Database (Denmark)

    Johansen, B H; Gjertsen, H A; Vartdal, F;

    1996-01-01

    Celiac disease (CD) is most probably an immunological disease, precipitated in susceptible individuals by ingestion of wheat gliadin and related proteins from other cereals. The disease shows a strong HLA association predominantly to the cis- or trans-encoded HLA-DQ(alpha1*0501, beta1*02) (i.e., DQ......2) heterodimer. T cell recognition of gliadin peptides presented by DQ2 in the intestinal mucosa is central in the immunopathogenesis of CD. Here we describe a study where overlapping peptides from the N-terminal region of alpha-gliadin have been tested in biochemical assays for binding to affinity......-purified DQ2 and DR3 (i.e., DR(alpha, beta1*0301)) molecules. The peptides were also tested for binding to DQ2 in a functional binding assay, where binding was measured as the capacity to inhibit the stimulation of a gliadin-specific, DQ2-restricted T lymphocyte clone RNnTalpha33. In both assay systems the...

  20. Analysis of Flavonoids in Lotus (Nelumbo nucifera Leaves and Their Antioxidant Activity Using Macroporous Resin Chromatography Coupled with LC-MS/MS and Antioxidant Biochemical Assays

    Directory of Open Access Journals (Sweden)

    Ming-Zhi Zhu

    2015-06-01

    Full Text Available Lotus (Nelumbo nucifera leaves, a traditional Chinese medicinal herb, are rich in flavonoids. In an effort to thoroughly analyze their flavonoid components, macroporous resin chromatography coupled with HPLC-MS/MS was employed to simultaneously enrich and identify flavonoids from lotus leaves. Flavonoids extracted from lotus leaves were selectively enriched in the macroporous resin column, eluted subsequently as fraction II, and successively subjected to analysis with the HPLC-MS/MS and bioactivity assays. Altogether, fourteen flavonoids were identified, four of which were identified from lotus leaves for the first time, including quercetin 3-O-rhamnopyranosyl-(1→2-glucopyranoside, quercetin 3-O-arabinoside, diosmetin 7-O-hexose, and isorhamnetin 3-O-arabino- pyranosyl-(1→2-glucopyranoside. Further bioactivity assays revealed that these flavonoids from lotus leaves possess strong antioxidant activity, and demonstrate very good potential to be explored as food supplements or even pharmaceutical products to improve human health.

  1. A Biochemical/Biophysical Assay Dyad for HTS-Compatible Triaging of Inhibitors of the HIV-1 Nef/Hck SH3 Interaction

    KAUST Repository

    Breuer, Sebastian

    2013-07-26

    The current treatment regimens for HIV include over 20 anti-retrovirals. However, adverse drug effects and the emergence of drug resistance necessitates the continued improvement of the existing drug classes as well as the development of novel drugs that target as yet therapeutically unexploited viral and cellular pathways. Here we demonstrate a strategy for the discovery of protein-protein interaction inhibitors of the viral pathogenicity factor HIV-1 Nef and its interaction with the host factor SH3. A combination of a time-resolved fluorescence resonance energy resonance energy transfer-based assay and a label-free resonant waveguide grating-based assay was optimized for high-throughput screening formats.

  2. Selective chromogenic and fluorogenic peptide substrates for the assay of cysteine peptidases in complex mixtures

    Czech Academy of Sciences Publication Activity Database

    Semashko, T. A.; Vorotnikova, E. A.; Sharikova, V. F.; Vinokurov, Konstantin; Smirnova, Y. A.; Dunaevsky, Y. E.; Belozersky, M. A.; Oppert, B.; Elpidina, E. N.; Filippova, I. Y.

    2014-01-01

    Roč. 449, č. 1 (2014), s. 179-187. ISSN 0003-2697 Grant ostatní: Russian Foundation for Basic Research (RU) 12-04-01562-a; Russian Foundation for Basic Research (RU) 12-03-01057-a; ISTC(RU) 3455 Institutional support: RVO:60077344 Keywords : cysteine peptidases * substrates of peptidases * selective peptide substrates Subject RIV: CE - Biochemistry Impact factor: 2.219, year: 2014 http://www. science direct.com/ science /article/pii/S0003269713006180#

  3. Evaluation of low-level laser therapy on skeletal muscle ischemia-reperfusion in streptozotocin-induced diabetic rats by assaying biochemical markers and histological changes.

    Science.gov (United States)

    Takhtfooladi, Hamed Ashrafzadeh; Asghari, Ahmad; Amirkamali, Sahar; Hoseinzadeh, Hesam Aldin; Takhtfooladi, Mohammad Ashrafzadeh

    2016-08-01

    The purpose of the present study was to assess the effects of low-level laser therapy (LLLT) on skeletal muscle ischemia-reperfusion (IR) injuries in streptozotocin-induced diabetic rats. Twenty male Wistar rats were randomly assigned into two experimental groups, as follows: the diabetic IR group (G1, n = 10) and the diabetic IR + LLLT group (G2, n = 10). Ischemia was induced in anesthetized rats from the right femoral artery clipping for 2 h, followed by a reperfusion for 24 h. Then, the laser irradiation (K30 handheld probe, AZOR, Technica, Russia, 650 nm, 30 mW, surface area = 1 cm(2), energy density = 1.8 J/cm(2)) was carried out by irradiating the rats over a unique point on the skin over the middle region of the right gastrocnemius muscle belly three times (every 8 h), starting after initiating the reperfusion for 3 min. At the end of the reperfusion period, rats were anaesthetized and blood samples were collected and used for the estimation of pO2, pCO2, pH, HCO3, serum creatine phosphokinase (CPK), and lactate dehydrogenase (LDH). Subsequently, the right gastrocnemius muscle samples were taken for wet/dry weight ratio assessment and histological/biochemical examination. The pO2, pCO2, HCO3, and pH levels were similar for both groups (P > 0.05). The serum LDH and CPK levels were significantly lower (P level in G2 was significantly decreased (P laser parameters and examining response over a longer period of tissue recovery. PMID:27250714

  4. Anionic chromogenic chemosensors highly selective for fluoride or cyanide based on 4-(4-Nitrobenzylideneamine)phenol

    Energy Technology Data Exchange (ETDEWEB)

    Nicoleti, Celso R.; Marini, Vanderleia G.; Zimmermann, Lizandra M.; Machado, Vanderlei G., E-mail: vanderlei.machado@ufsc.br [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-08-15

    4-(4-Nitrobenzylideneamine)phenol was used in two strategies allowing the highly selective detection of F{sup -} and CN{sup -}. Firstly, the compound in acetonitrile acts as a chromogenic chemosensor based on the idea that more basic anions cause its deprotonation (colorless solution), generating a colored solution containing phenolate. The discrimination of CN{sup -} over F{sup -} was obtained by adding 1.4% water to acetonitrile: water preferentially solvates F{sup -}, leaving the CN{sup -} free to deprotonate the compound. Another strategy involved an assay comprised of the competition between phenolate dye and the analyte for calyx[4]pyrrole in acetonitrile, a receptor highly selective for F{sup -}. Phenolate and calyx[4]pyrrole form a hydrogen-bonded complex, which changes the color of the medium. On the addition of various anions, only F{sup -} was able to restore the original color corresponding to phenolate in solution due to the fact that the anion dislodges phenolate from the complexation site. (author)

  5. Synthesis and characterization of chromogenic fluoran compounds containing 4-ketoquinazolinone moieties

    OpenAIRE

    RANJAN G. PATEL; MANISH P. PATEL; RITESH G. PATEL

    2004-01-01

    Chromogenic fluoran compounds containing 4-ketoquinazolinone were synthesized by reacting 2-(4-diethylamino-2-hydroxybenzoyl)benzoic acid with various substituted 4-ketoquinazolinones in the presence of sulfuric acid. The 4-ketoquinazolinones were obtained by reacting various substituted benzoxazin-4-ones with 4-aminophenol or 2-nitro-p-anisidine. All the synthesized derivatives were identified by conventional methods, such as melting points, elemental analysis, IR, 1H-NMR, and UV-visible spe...

  6. Novel chromogenic aminopeptidase substrates for the detection and identification of clinically important microorganisms

    OpenAIRE

    Cellier, Marie; James, Arthur; Orenga, Sylvain; Perry, John; Rasul, Ari; Robinson, Shaun; Stanforth, Stephen

    2014-01-01

    A series of amino acid derivatives 8-10, 42 and 43 have been prepared as chromogenic enzyme substrates in order to detect aminopeptidase activity in clinically important Gram-negative and Gram-positive bacteria. Enzymatic hydrolysis liberates the amino acid moiety and either a 4-aminophenol or a 4-dialkylaminoaniline derivative which undergoes oxidative coupling with 1-naphthol or a substituted 1-naphthol giving an indophenol dye. Substrates and 1-naphthols were incorporated into an agar-base...

  7. Evaluation of chromogenic media and seminested PCR in the identification of Candida species

    OpenAIRE

    Enas Daef; Ahmed Moharram; Salwa Seif Eldin; Nahla Elsherbiny; Mona Mohammed

    2014-01-01

    Identification of Candida cultured from various clinical specimens to the species level is increasingly necessary for clinical laboratories. Although sn PCR identifies the species within hours but its cost-effectiveness is to be considered. So there is always a need for media which help in the isolation and identification at the species level. The study aimed to evaluate the performance of different chromogenic media and to compare the effectiveness of the traditional phenotypic methods vs. s...

  8. Chromogenic and fluorogenic detection and discrimination of nerve agents Tabun and Vx.

    Science.gov (United States)

    Kumar, Vinod; Rana, Hemlata

    2015-11-28

    Our approach uses squaraine (SQ) as the molecular-receptor as well as an indicator for the chromogenic and fluorogenic detection and discrimination of nerve agents Tabun and Vx. To mimic a real-life scenario, the protocols were implemented in spiked water and soil samples, on surfaces, and in the gas phase. The lower detection limit will be useful to protect human health and national security. PMID:26394304

  9. Development and Evaluation of a Chromogenic Agar Medium for Methicillin-Resistant Staphylococcus aureus

    OpenAIRE

    Perry, John D.; Davies, Amie; Butterworth, Lynne A.; Hopley, Andrew L. J.; Nicholson, Audrey; Gould, F. Kate

    2004-01-01

    We describe here the development and evaluation of MRSA ID, a new chromogenic agar medium for the specific isolation and identification of methicillin-resistant Staphylococcus aureus (MRSA). We used S. aureus ID (bioMérieux, La Balme Les Grottes, France) and supplemented it with various antimicrobials, including cefoxitin, ciprofloxacin, oxacillin, and methicillin. Cefoxitin proved to be superior to the other antimicrobials for the selection of MRSA from other strains of S. aureus. MRSA ID (c...

  10. Evaluation of the Q analyzer, a new cap-piercing fully automated coagulometer with clotting, chromogenic, and immunoturbidometric capability.

    Science.gov (United States)

    Kitchen, Steve; Woolley, Anita

    2013-01-01

    The Q analyzer is a recently launched fully automated photo-optical analyzer equipped with primary tube cap-piercing and capable of clotting, chromogenic, and immunoturbidometric tests. The purpose of the present study was to evaluate the performance characteristics of the Q analyzer with reagents from the instrument manufacturer. We assessed precision and throughput when performing coagulation screening tests, prothrombin time (PT)/international normalized ratio (INR), activated partial thromboplastin time (APTT), and fibrinogen assay by Clauss assay. We compared results with established reagent instrument combinations in widespread use. Precision of PT/INR and APTT was acceptable as indicated by total precision of around 3%. The time to first result was 3  min for an INR and 5  min for PT/APTT. The system produced 115 completed samples per hour when processing only INRs and 60 samples (120 results) per hour for PT/APTT combined. The sensitivity of the DG-APTT Synth/Q method to mild deficiency of factor VIII (FVIII), IX, and XI was excellent (as indicated by APTTs being prolonged above the upper limit of the reference range). The Q analyzer was associated with high precision, acceptable throughput, and good reliability. When used in combination with DG-PT reagent and manufacturer's instrument-specific international sensitivity index, the INRs obtained were accurate. The Q analyzer with DG-APTT Synth reagent demonstrated good sensitivity to isolated mild deficiency of FVIII, IX, and XI and had the advantage of relative insensitivity to mild FXII deficiency. Taken together, our data indicate that the Q hemostasis analyzer was suitable for routine use in combination with the reagents evaluated. PMID:23249565

  11. Biochemical assays with radio-iodinated substrates

    International Nuclear Information System (INIS)

    A sensitive radiochemical method for the measurement of nanogram amounts of ammonia applicable to studies of enzymatic or other processes releasing or utilizing ammonia was developed. The method is based on a modified Berthelot reaction between ammonia and an aqueous alkaline solution of phenol and sodium hypochloride to yield indophenol. The radioactive tracer used is 125I-o-iodophenol, prepared by iodination of phenol with 125I by the chloramine-T method. A chloroform/carbon tetrachloride mixture is used to extract unreacted 125I-o-iodophenol from the reaction mixture; the 125I-labelled product remains in the aqueous phase and is measured by scintillation counting. Non-protein nitrogenous substances and certain other compounds interfere with the reaction, which cannot thus be used to measure ammonia directly in biological fluids. The glass Conway microdiffusion cell may, however, be utilized to isolate small amounts of ammonia from such fluids for measurement. The fluid is placed in the centre well of the cell and cold water in the outer well. Warm saturated potassium carbonate solution is then added to the centre well to expel the ammonia gas which is absorbed by the water. Technical details of the method are given

  12. Evolution and characterization of a new reversibly photoswitching chromogenic protein, Dathail.

    Science.gov (United States)

    Langan, Patricia S; Close, Devin W; Coates, Leighton; Rocha, Reginaldo C; Ghosh, Koushik; Kiss, Csaba; Waldo, Geoff; Freyer, James; Kovalevsky, Andrey; Bradbury, Andrew R M

    2016-05-01

    We report the engineering of a new reversibly switching chromogenic protein, Dathail. Dathail was evolved from the extremely thermostable fluorescent proteins thermal green protein (TGP) and eCGP123 using directed evolution and ratiometric sorting. Dathail has two spectrally distinct chromogenic states with low quantum yields, corresponding to absorbance in a ground state with a maximum at 389nm, and a photo-induced metastable state with a maximum at 497nm. In contrast to all previously described photoswitchable proteins, both spectral states of Dathail are non-fluorescent. The photo-induced chromogenic state of Dathail has a lifetime of ~50min at 293K and pH7.5 as measured by UV-Vis spectrophotometry, returning to the ground state through thermal relaxation. X-ray crystallography provided structural insights supporting a change in conformation and coordination in the chromophore pocket as being responsible for Dathail's photoswitching. Neutron crystallography, carried out for the first time on a protein from the green fluorescent protein family, showed a distribution of hydrogen atoms revealing protonation of the chromophore 4-hydroxybenzyl group in the ground state. The neutron structure also supports the hypothesis that the photo-induced proton transfer from the chromophore occurs through water-mediated proton relay into the bulk solvent. Beyond its spectroscopic curiosity, Dathail has several characteristics that are improvements for applications, including low background fluorescence, large spectral separation, rapid switching time, and the ability to switch many times. Therefore, Dathail is likely to be extremely useful in the quickly developing fields of imaging and biosensors, including photochromic Förster resonance energy transfer, high-resolution microscopy, and live tracking within the cell. PMID:27000644

  13. Salivary thiol levels and periodontal parameters assessed with a chromogenic strip.

    Science.gov (United States)

    Khocht, Ahmed; Seyedain, Merriam; Hardan, Samia; Gaughan, John; Suzuki, Jon B

    2013-08-01

    Periodontitis tends to be associated with bacteria that use sulfate as an energy source and produce thiol compounds that contain sulfhydryl (-SH) groups. This study used a chromogenic thiol-detecting strip to investigate whole saliva -SH concentration (SS) in subjects with and without periodontal disease. Ninety-six subjects were enrolled; all underwent periodontal evaluations, including plaque index (PI), gingival index (GI), probing depth measurements (PD), and attachment levels (AL). Subjects were divided into 3 groups: those who were periodontally healthy (n = 17), those with gingivitis (n = 54), and those with periodontitis (n = 25). Of the 96 subjects, 33% (n = 32) were cigarette smokers. A chromogenic strip was used to collect a whole saliva sample from the mouth. Color reaction was scored based on a color chart. Good-to-moderate correlations were found between SS scores and PI (r = 0.47, P = 0.0001), GI (r = 0.45, P = 0.0001), PD (r = 0.42, P = 0.0001), and AL (r = 0.30, P = 0.002). Analysis of variance showed significant differences in SS scores among the 3 study groups (P = 0.0001); post-hoc analysis showed higher SS scores in subjects with periodontitis than in those without (P = 0.05). Logistic regression, adjusting for smoking, showed the odds ratio of periodontitis increased by a factor of 12.76 for each increase of one unit of measure of SS. These results indicate that assessing whole saliva thiol levels with a chromogenic strip could be used as a screening test for periodontal diseases. PMID:23928440

  14. Synthesis and characterization of chromogenic fluoran compounds containing 4-ketoquinazolinone moieties

    Directory of Open Access Journals (Sweden)

    RANJAN G. PATEL

    2004-05-01

    Full Text Available Chromogenic fluoran compounds containing 4-ketoquinazolinone were synthesized by reacting 2-(4-diethylamino-2-hydroxybenzoylbenzoic acid with various substituted 4-ketoquinazolinones in the presence of sulfuric acid. The 4-ketoquinazolinones were obtained by reacting various substituted benzoxazin-4-ones with 4-aminophenol or 2-nitro-p-anisidine. All the synthesized derivatives were identified by conventional methods, such as melting points, elemental analysis, IR, 1H-NMR, and UV-visible spectroscopy in organic solvent and 95 % acetic acid. All the fluoran compounds develop colour on contact with acidic or electron-accepting compounds.

  15. Evaluation of chromogenic media and seminested PCR in the identification of Candida species

    Directory of Open Access Journals (Sweden)

    Enas Daef

    2014-01-01

    Full Text Available Identification of Candida cultured from various clinical specimens to the species level is increasingly necessary for clinical laboratories. Although sn PCR identifies the species within hours but its cost-effectiveness is to be considered. So there is always a need for media which help in the isolation and identification at the species level. The study aimed to evaluate the performance of different chromogenic media and to compare the effectiveness of the traditional phenotypic methods vs. seminested polymerase chain reaction (sn PCR for identification of Candida species. One hundred and twenty seven Candida strains isolated from various clinical specimens were identified by conventional methods, four different chromogenic media and sn PCR. HiCrome Candida Differential and CHROMagar Candida media showed comparably high sensitivities and specificities in the identification of C. albicans, C. tropicalis, C. glabrata and C. krusei. CHROMagar Candida had an extra advantage of identifying all C. parapsilosis isolates. CHROMagar-Pal's medium identified C. albicans, C. tropicalis and C. krusei with high sensitivities and specificities, but couldn't identify C. glabrata or C. parapsilosis. It was the only medium that identified C. dubliniensis with a sensitivity and specificity of 100%. Biggy agar showed the least sensitivities and specificities. The overall concordance of the snPCR compared to the conventional tests including CHROMAgar Candida in the identification of Candida species was 97.5%. The use of CHROMAgar Candida medium is an easy and accurate method for presumptive identification of the most commonly encountered Candida spp.

  16. Hyperspectral imaging for presumptive identification of bacterial colonies on solid chromogenic culture media

    Science.gov (United States)

    Guillemot, Mathilde; Midahuen, Rony; Archeny, Delpine; Fulchiron, Corine; Montvernay, Regis; Perrin, Guillaume; Leroux, Denis F.

    2016-04-01

    BioMérieux is automating the microbiology laboratory in order to reduce cost (less manpower and consumables), to improve performance (increased sensitivity, machine algorithms) and to gain traceability through optimization of the clinical laboratory workflow. In this study, we evaluate the potential of Hyperspectral imaging (HSI) as a substitute to human visual observation when performing the task of microbiological culture interpretation. Microbial colonies from 19 strains subcategorized in 6 chromogenic classes were analyzed after a 24h-growth on a chromogenic culture medium (chromID® CPS Elite, bioMérieux, France). The HSI analysis was performed in the VNIR region (400-900 nm) using a linescan configuration. Using algorithms relying on Linear Spectral Unmixing, and using exclusively Diffuse Reflectance Spectra (DRS) as input data, we report interclass classification accuracies of 100% using a fully automatable approach and no use of morphological information. In order to eventually simplify the instrument, the performance of degraded DRS was also evaluated using only the most discriminant 14 spectral channels (a model for a multispectral approach) or 3 channels (model of a RGB image). The overall classification performance remains unchanged for our multispectral model but is degraded for the predicted RGB model, hints that a multispectral solution might bring the answer for an improved colony recognition.

  17. Using selective chromogenic plates to optimize isolation of group B Streptococcus in pregnant women

    Directory of Open Access Journals (Sweden)

    Romano Mattei

    2014-03-01

    Full Text Available Group B Streptococcus (GBS remains the leading cause of severe bacterial infections (sepsis, meningitis, pneumonia in neonates. We compared the detection of GBS from recto-vaginal swabs on blood agar and two chromogenic media and evaluated their antibiotic susceptibility. A total of 1351 swabs were taken from pregnant women at 35-37 weeks of gestation. Following enrichment in Todd Hewitt broth + nalidixic acid and colistin, the samples were plated on Columbia CNA agar (CNA, chromID Strepto B agar (STRB and Granada Agar (GRAN, respectively. GBS were found in 22.4% of recto-vaginal swabs from pregnant women. Sensitivity, specificity, positive and negative predictive values of GBS detection were 88%, 88%, 81% and 96% for CNA, 99%, 97%, 90% and 99% for STRB and 94%, 99%, 98% e 99% for GRAN; Cohen’s k index concordances for CNA, STREB and GRAN were 0.68, 0.92 and 0.96, respectively. All isolates were susceptible to penicillin, whereas resistances of erythromycin and clindamycin were 40% and 42%, respectively. To conclude, selective broth enrichment combined with chromogenic plates is recommended for GBS screening in pregnant women.

  18. Performance of chromogenic media for Candida in rapid presumptive identification of Candida species from clinical materials

    Directory of Open Access Journals (Sweden)

    M V Pravin Charles

    2015-01-01

    Full Text Available Background: In perspective of the worldwide increase in a number of immunocompromised patients, the need for identification of Candida species has become a major concern. The development of chromogenic differential media, introduced recently, facilitate rapid speciation. However, it can be employed for routine mycology workup only after an exhaustive evaluation of its benefit and cost effectiveness. This study was undertaken to evaluate the benefit and cost effectiveness of chromogenic media for speciation of Candida clinical isolates. Materials and Methods: Sputum samples of 382 patients were screened for the presence of Candida spp. by Gram stain and culture on sabouraud dextrose agar. Candida species were identified using Gram stain morphology, germ tube formation, cornmeal agar with Tween-80, sugar fermentation tests and morphology on HiCrome Candida differential agar. All the Candida isolates were inoculated on HiCrome Candida agar (HiMedia, Mumbai, India. Results: The sensitivity and specificity of HiCrome agar for identification of Candida albicans were 90% and 96.42%, respectively whereas sensitivity and specificity of carbohydrate fermentation test were 86.67% and 74.07%, respectively. Sensitivity and specificity values of HiCrome agar for detection of C. albicans, Candida parapsilosis and Candida glabrata were above 90%. Conclusions: We found HiCrome agar has high sensitivity and specificity comparable to that of the conventional method. In addition, use of this differential media could significantly cut down the turnaround time as well as cost of sample processing.

  19. Polydiacetylene films: a review of recent investigations into chromogenic transitions and nanomechanical properties

    International Nuclear Information System (INIS)

    Polydiacetylenes (PDAs) form a unique class of polymeric materials that couple highly aligned and conjugated backbones with tailorable pendant side-groups and terminal functionalities. They can be structured in the form of bulk materials, multilayer and monolayer films, polymerized vesicles, and even incorporated into inorganic host matrices to form nanocomposites. The resulting materials exhibit an array of spectacular properties, beginning most notably with dramatic chromogenic transitions that can be activated optically, thermally, chemically, and mechanically. Recent studies have shown that these transitions can even be controlled and observed at the nanometre scale. These transitions have been harnessed for the purpose of chemical and biomolecular sensors, and on a more fundamental level have led to new insights regarding chromogenic phenomena in polymers. Other recent studies have explored how the strong structural anisotropy that these materials possess leads to anisotropic nanomechanical behaviour. These recent advances suggest that PDAs could be considered as a potential component in nanostructured devices due to the large number of tunable properties. In this paper, we provide a succinct review of the latest insights and applications involving PDA. We then focus in more detail on our work concerning ultrathin films, specifically structural properties, mechanochromism, thermochromism, and in-plane mechanical anisotropy of PDA monolayers. Atomic force microscopy (AFM) and fluorescence microscopy confirm that films 1-3 monolayers thick can be organized into highly ordered domains, with the conjugated backbones parallel to the substrate. The number of stable layers is controlled by the head-group functionality. Local mechanical stress applied by AFM and near-field optical probes induces the chromogenic transition in the film at the nanometre scale. The transition involves substantial optical and structural changes in a highly compressed form. Thermochromism

  20. Biochemical Filter with Sigmoidal Response: Increasing the Complexity of Biomolecular Logic

    CERN Document Server

    Privman, Vladimir; Arugula, Mary A; Melnikov, Dmitriy; Bocharova, Vera; Katz, Evgeny

    2010-01-01

    The first realization of a designed, rather than natural, biochemical filter process is reported and analyzed as a promising network component for increasing the complexity of biomolecular logic systems. Key challenge in biochemical logic research has been achieving scalability for complex network designs. Various logic gates have been realized, but a "toolbox" of analog elements for interconnectivity and signal processing has remained elusive. Filters are important as network elements that allow control of noise in signal transmission and conversion. We report a versatile biochemical filtering mechanism designed to have sigmoidal response in combination with signal-conversion process. Horseradish peroxidase-catalyzed oxidation of chromogenic electron donor by hydrogen peroxide, was altered by adding ascorbate, allowing to selectively suppress the output signal, modifying the response from convex to sigmoidal. A kinetic model was developed for evaluation of the quality of filtering. The results offer improved...

  1. Changes in the chromogen properties of the betalaine induced by gamma radiation

    International Nuclear Information System (INIS)

    The changes of coloration of four natural extracts in function of the absorbed dose produced by a gamma rays source of 137 Cs were determined. The natural extracts used contain betalaines that are natural pigments of some plants as the beet about that their name. They are also in abundant form in the fruits (tunas) of some species of the Opuntia genus. The extracts were obtained by maceration, starting from beet and three tuna varieties, and they were stabilized to pH 5.5 The change of coloration it was determined in a visible ultraviolet spectrophotometer by means of the absorbance from the samples to photons of 475, 535 and 600 nm of wavelength. The absorbance to different intervals of time was measured. The relationship between the absorbed dose and the chromogene properties of the pigment, with the intention of using it as possible dosemeter was settled down. (Author)

  2. Near-Infrared Fluorescence of the NBT/BCIP Chromogenic Stain

    Science.gov (United States)

    McCutchen, M. D.; Bumm, L. A.; McCauley, D. W.; Trinh, L. A.; Bonner-Fraser, M.; Fraser, S. E.

    2007-03-01

    We demonstrate the previously unreported near infrared (NIR) fluorescence of the dark purple stain formed from 5-bromo-4-chloro-3-indolyl phosphate (BCIP) and nitro blue tetrazolium (NBT). Although the product is a solid with strong optical absorption, its fluorescence enables high cellular resolution imaging of gene expression. We use spectrofluorometry to identify NBT diformazan as the component of the stain that is the fluorophore exhibiting the strong fluorescence signal. The fluorescence shows an intense emission signal (780-910 nm) that is well separated from excitation (645-685 nm). The NBT diformazan fluorescence is also photostable. Because NBT/BCIP is a widely used chromogenic stain, existing staining protocols can also be applied to fluorescence imaging techniques to increase the resolution of gene expression patterns.

  3. Evaluation of isolation procedures and chromogenic agar media for detection of MRSA in nasal swabs from pigs and veal calves.

    OpenAIRE

    Graveland, Haitske; van Duijkeren, Engeline; Van Nes, Arie; Schoormans, Anky; Broekhuizen-Stins, Marian; Schothorst, Isabella Oosting-Van; Heederik, Dick; Wagenaar, Jaap A.

    2009-01-01

    Abstract Since the emergence of MRSA in livestock, screening of animals for the detection of MRSA is widely practised. Different procedures are published for animal samples but a systematic comparison of methods has not been performed. The objective of this study was to compare three available commonly used procedures and three chromogenic agars for detecting MRSA in nasal swabs from pigs (n=70) and veal calves (n=100). Procedures 1 and 2 used a pre-enrichment comprising Mueller Hi...

  4. Presumptive identification of Candida species other than C. albicans, C. krusei, and C. tropicalis with the chromogenic medium CHROMagar Candida

    OpenAIRE

    Horvath Lynn L; Floyd Karon L; Beckius Miriam L; Hospenthal Duane R; Murray Clinton K

    2006-01-01

    Abstract Background CHROMagar Candida (CaC) is increasingly being reported as a medium used to differentiate Candida albicans from non-albicans Candida (NAC) species. Rapid identification of NAC can assist the clinician in selecting appropriate antifungal therapy. CaC is a differential chromogenic medium designed to identify C. albicans, C. krusei, and C. tropicalis based on colony color and morphology. Some reports have proposed that CaC can also reliably identify C. dubliniensis and C. glab...

  5. Automated measurement of estrogen receptor in breast cancer: a comparison of fluorescent and chromogenic methods of measurement.

    Science.gov (United States)

    Zarrella, Elizabeth R; Coulter, Madeline; Welsh, Allison W; Carvajal, Daniel E; Schalper, Kurt A; Harigopal, Malini; L Rimm, David; M Neumeister, Veronique

    2016-09-01

    Whereas FDA-approved methods of assessment of estrogen receptor (ER) are 'fit for purpose', they represent a 30-year-old technology. New quantitative methods, both chromogenic and fluorescent, have been developed and studies have shown that these methods increase the accuracy of assessment of ER. Here, we compare three methods of ER detection and assessment on two retrospective tissue microarray (TMA) cohorts of breast cancer patients: estimates of percent nuclei positive by pathologists and by Aperio's nuclear algorithm (standard chromogenic immunostaining), and immunofluorescence as quantified with the automated quantitative analysis (AQUA) method of quantitative immunofluorescence (QIF). Reproducibility was excellent (R(2)>0.95) between users for both automated analysis methods, and the Aperio and QIF scoring results were also highly correlated, despite the different detection systems. The subjective readings show lower levels of reproducibility and a discontinuous, bimodal distribution of scores not seen by either mechanized method. Kaplan-Meier analysis of 10-year disease-free survival was significant for each method (Pathologist, P=0.0019; Aperio, P=0.0053, AQUA, P=0.0026); however, there were discrepancies in patient classification in 19 out of 233 cases analyzed. Out of these, 11 were visually positive by both chromogenic and fluorescent detection. In 10 cases, the Aperio nuclear algorithm labeled the nuclei as negative; in 1 case, the AQUA score was just under the cutoff for positivity (determined by an Index TMA). In contrast, 8 out of 19 discrepant cases had clear nuclear positivity by fluorescence that was unable to be visualized by chromogenic detection, perhaps because of low positivity masked by the hematoxylin counterstain. These results demonstrate that automated systems enable objective, precise quantification of ER. Furthermore, immunofluorescence detection offers the additional advantage of a signal that cannot be masked by a counterstaining

  6. Novel chromogenic aminopeptidase substrates for the detection and identification of clinically important microorganisms.

    Science.gov (United States)

    Cellier, Marie; James, Arthur L; Orenga, Sylvain; Perry, John D; Rasul, Ari K; Robinson, Shaun N; Stanforth, Stephen P

    2014-10-01

    A series of amino acid derivatives 8-10, 42 and 43 have been prepared as chromogenic enzyme substrates in order to detect aminopeptidase activity in clinically important Gram-negative and Gram-positive bacteria. Enzymatic hydrolysis liberates the amino acid moiety and either a 4-aminophenol or a 4-dialkylaminoaniline derivative which undergoes oxidative coupling with 1-naphthol or a substituted 1-naphthol giving an indophenol dye. Substrates and 1-naphthols were incorporated into an agar-based culture medium and this allowed growth of intensely coloured bacterial colonies based on hydrolysis by specific enzymes. Red/pink coloured colonies were produced by the substrates 8-10 and blue coloured colonies were formed by the substrates 42 and 43. The L-alanyl aminopeptidase substrates 8 targeted L-alanyl aminopeptidase activity and gave coloured colonies with a range of Gram-negative bacteria. Substrates 9 targeted β-alanyl aminopeptidase activity and generated coloured colonies with selected Gram-negative species including Pseudomonas aeruginosa. Three substrates for L-pyroglutamyl acid aminopeptidase (10a, 10c and 43) were hydrolysed by enterococci and Streptococcus pyogenes to generate coloured colonies. Two yeasts were also included in the study, but they did not produce coloured colonies with any of the substrates examined. PMID:25172150

  7. Chromogene properties of the betalains before gamma photons; Propiedades cromogenas de las betalainas ante fotones gamma

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez N, S.; Quintero M, C. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Ciencias Quimicas, Programa de Quimica en Alimentos, Km. 0.5 Carretera a Guadalajara Ejido La Escondida, Zacatecas (Mexico); Vega C, H. R., E-mail: srneri@hotmail.co [Universidad Autonoma de Zacatecas, Unidad Academica de Ciencias Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2010-09-15

    The coloration changes of four natural extracts in function of the absorbed dose produced by a gamma rays source of {sup 137}Cs have been studied. The natural extracts were obtained of tuna varieties that contain betalains that are natural pigments of some plants as the beet of where is derived its name. These also are found in abundant form in the fruits of some species of opuntia genus (tunas). The extracts were obtained by maceration, starting from beet and three tuna varieties that were stabilized to a p H of 5.5. The extracts were exposed to the gamma rays of a {sup 137}Cs source and the change in the coloration was observed by means of an ultra violet/visible spectrophotometer through of the absorption of the samples to photons of wave longitude 535 nm. The absorption was measured, to different time intervals. The relation between the absorbed dose in D{sub w} water and the chromogene properties of the pigment was established, with the intention of using it as possible dosemeter. (Author)

  8. Gene numerical imbalances in cytological specimens based on fluorescence/chromogenic in situ hybridization analysis.

    Science.gov (United States)

    Tsiambas, E; Karameris, A; Lygeros, M; Athanasiou, A E; Salemis, N S; Gourgiotis, S; Ragkos, V; Metaxas, G E; Vilaras, G; Patsouris, E

    2012-01-01

    Design and development of novel targeted therapeutic strategies is an innovation in handling patients with solid malignancies including breast, colon, lung, head & neck or even pancreatic and hepatocellular carcinoma. For a long time, immunohistocytochemistry (IHC/ICC) has been performed as a routine method in almost all labs for evaluating protein expression. Modern molecular approaches show that identification of specific structural and numerical imbalances regarding genes involved in signal transduction pathways provide important data to the oncologists. Alterations in molecules such as epidermal growth factor receptor (EGFR), HER2/neu, PTEN or Topoisomerase IIa affect the response rates to specific chemotherapeutic agents modifying also patients' prognostic rates. In situ hybridization (ISH) techniques based on fluorescence and chromogenic variants (FISH/CISH) or silver in situ hybridization (SISH) are applicable in both tissue and cell substrates. Concerning cytological specimens, FISH/CISH analysis appears to be a fast and very accurate method in estimating gene/chromosome ratios. In this paper, we sought to evaluate the usefulness of FISH/ CISH analysis in cytological specimens, describing also the advantages and disadvantages of these methods from the technical point of view. PMID:23033306

  9. Biochemical markers of bone turnover

    International Nuclear Information System (INIS)

    Biochemical markers of bone turnover has received increasing attention over the past few years, because of the need for sensitivity and specific tool in the clinical investigation of osteoporosis. Bone markers should be unique to bone, reflect changes of bone less, and should be correlated with radiocalcium kinetics, histomorphometry, or changes in bone mass. The markers also should be useful in monitoring treatment efficacy. Although no bone marker has been established to meet all these criteria, currently osteocalcin and pyridinium crosslinks are the most efficient markers to assess the level of bone turnover in the menopausal and senile osteoporosis. Recently, N-terminal telopeptide (NTX), C-terminal telopeptide (CTX) and bone specific alkaline phosphatase are considered as new valid markers of bone turnover. Recent data suggest that CTX and free deoxypyridinoline could predict the subsequent risk of hip fracture of elderly women. Treatment of postmenopausal women with estrogen, calcitonin and bisphosphonates demonstrated rapid decrease of the levels of bone markers that correlated with the long-term increase of bone mass. Factors such as circadian rhythms, diet, age, sex, bone mass and renal function affect the results of biochemical markers and should be appropriately adjusted whenever possible. Each biochemical markers of bone turnover may have its own specific advantages and limitations. Recent advances in research will provide more sensitive and specific assays

  10. Development of a Novel Chromogenic Medium for Improved Campylobacter Detection from Poultry Samples.

    Science.gov (United States)

    Teramura, Hajime; Iwasaki, Mihoko; Ogihara, Hirokazu

    2015-09-01

    The presence of expanded-spectrum β-lactamase (ESBL)-producing Escherichia coli is a common problem in the isolation of Campylobacter from poultry samples using conventional cefoperazone-based selective media. A novel chromogenic medium (CM-HT), based on modified charcoal cefoperazone deoxycholate agar (mCCDA), has been developed as a solution for improved Campylobacter detection from poultry samples. Although the basic components of CM-HT are the same as mCCDA, CM-HT uses both granular charcoal and sodium cefoxitin to enhance viewability and inhibit ESBL-producing bacteria. All tested Campylobacter jejuni (n = 31) and Campylobacter coli (n = 6) strains grew and formed purple-colored colonies on CM-HT. In contrast, the growth of all other tested microorganisms, including ESBL-producing E. coli strains, was suppressed by this medium. Additionally, 84 poultry samples were examined for the presence of Campylobacter using the ISO 10272-1 method (enrichment with Bolton broth) and the NIHSJ-02 method (enrichment with Preston broth) with mCCDA and CM-HT media for the isolation. The numbers of samples from which Camplylobacter was detected on CM-HT using Preston and Bolton broth were 22 and 18, whereas the numbers on mCCDA were 22 and 13, respectively. Only Campylobacter was detected on CM-HT using both enrichment broths; however, there were 5 and 19 samples from which ESBL-producing E. coli was detected on mCCDA using Preston and Bolton broth, respectively. Thus, there was a significant difference between CM-HT and mCCDA in selectivity for ESBL-producing E. coli regardless of which enrichment broth was used. The results obtained demonstrated that CM-HT is a possible solution for the improved isolation of Campylobacter from poultry samples. PMID:26319731

  11. Comparison of Chromogenic In Situ Hybridisation with Fluorescence In Situ Hybridisation and Immunohistochemistry for the Assessment of Her-2/neu Oncogene in Archival Material of Breast Carcinoma

    International Nuclear Information System (INIS)

    The successful treatment of breast cancer is dependent upon a number of complex factors. Her-2/neu gene amplification is known to be one of the most common genetic alterations associated with breast cancer and its accurate determination has become necessary for the selection of patients for trastuzumab therapy. The aim of this study was to prove the consistency of chromogenic in situ hybridisation (CISH) technique after analyzing the overexpression of the Her-2/neu proto-oncogene in 100 invasive breast carcinomas and by comparing CISH results with immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH). Moreover, it was done to evaluate the possible correlation of estrogen (ERs) and progesterone receptors (PRs), the proliferation marker Ki67 and the tumour suppressor gene p53 with HER-2/neu status of these breast carcinomas. Of the 100 breast carcinomas that were analysed, 22 cases showed HER-2/neu amplification, 66 cases showed no amplification, whereas 12 cases were non-interpretable in both assays (FISH and CISH). Consequently, the overall concordance between FISH and CISH was 100%. Additionally, it was observed that when HER-2/neu gene was overexpressed, there was an association with negative PRs and ERs status, negative p53 protein expression and high Ki67 labelling index. It is concluded that patients with tumours scoring 2+ with the CBE356 antibody (borderline immunohistochemistry-tested cases) would also benefit from CISH as it is shown to be highly accurate, practical and can be easily integrated into routine testing in any histopathology laboratory. Finally, CISH represents an important addition to the HER2 testing algorithm

  12. Quantitative real-time RT-PCR and chromogenic in situ hybridization: precise methods to detect HER-2 status in breast carcinoma

    International Nuclear Information System (INIS)

    HER-2 gene testing has become an integral part of breast cancer patient diagnosis. The most commonly used assay in the clinical setting for evaluating HER-2 status is immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). These procedures permit correlation between HER-2 expression and morphological features. However, FISH signals are labile and fade over time, making post-revision of the tumor difficult. CISH (chromogenic in situ hybridization) is an alternative procedure, with certain advantages, although still limited as a diagnostic tool in breast carcinomas. To elucidate the molecular profile of HER-2 status, mRNA and protein expression in 75 invasive breast carcinomas were analyzed by real time quantitative RT-PCR (qRT-PCR) and IHC, respectively. Amplifications were evaluated in 43 of these cases by CISH and in 11 by FISH. The concordance rate between IHC and qRT-PCR results was 78.9%, and 94.6% for qRT-PCR and CISH. Intratumoral heterogeneity of HER-2 status was identified in three cases by CISH. The results of the three procedures were compared and showed a concordance rate of 83.8%; higher discordances were observed in 0 or 1+ immunostaining cases, which showed high-level amplification (15.4%) and HER-2 transcript overexpression (20%). Moreover, 2+ immunostaining cases presented nonamplified status (50%) by CISH and HER-2 downexpression (38.5%) by qRT-PCR. In general, concordance occurred between qRT-PCR and CISH results. A high concordance was observed between CISH/qRT-PCR and FISH. Comparisons with clinicopathological data revealed a significant association between HER-2 downexpression and the involvement of less than four lymph nodes (P = 0.0350). Based on these findings, qRT-PCR was more precise and reproducible than IHC. Furthermore, CISH was revealed as an alternative and useful procedure for investigating amplifications involving the HER-2 gene

  13. Automated Scoring of Chromogenic Media for Detection of Methicillin-Resistant Staphylococcus aureus by Use of WASPLab Image Analysis Software.

    Science.gov (United States)

    Faron, Matthew L; Buchan, Blake W; Vismara, Chiara; Lacchini, Carla; Bielli, Alessandra; Gesu, Giovanni; Liebregts, Theo; van Bree, Anita; Jansz, Arjan; Soucy, Genevieve; Korver, John; Ledeboer, Nathan A

    2016-03-01

    Recently, systems have been developed to create total laboratory automation for clinical microbiology. These systems allow for the automation of specimen processing, specimen incubation, and imaging of bacterial growth. In this study, we used the WASPLab to validate software that discriminates and segregates positive and negative chromogenic methicillin-resistant Staphylococcus aureus (MRSA) plates by recognition of pigmented colonies. A total of 57,690 swabs submitted for MRSA screening were enrolled in the study. Four sites enrolled specimens following their standard of care. Chromogenic agar used at these sites included MRSASelect (Bio-Rad Laboratories, Redmond, WA), chromID MRSA (bioMérieux, Marcy l'Etoile, France), and CHROMagar MRSA (BD Diagnostics, Sparks, MD). Specimens were plated and incubated using the WASPLab. The digital camera took images at 0 and 16 to 24 h and the WASPLab software determined the presence of positive colonies based on a hue, saturation, and value (HSV) score. If the HSV score fell within a defined threshold, the plate was called positive. The performance of the digital analysis was compared to manual reading. Overall, the digital software had a sensitivity of 100% and a specificity of 90.7% with the specificity ranging between 90.0 and 96.0 across all sites. The results were similar using the three different agars with a sensitivity of 100% and specificity ranging between 90.7 and 92.4%. These data demonstrate that automated digital analysis can be used to accurately sort positive from negative chromogenic agar cultures regardless of the pigmentation produced. PMID:26719443

  14. Standardization of reagents and methods used in cytological and histological practice with emphasis on dyes, stains and chromogenic reagents

    DEFF Research Database (Denmark)

    Lyon, H O; De Leenheer, A P; Horobin, R W;

    1994-01-01

    The need for the standardization of reagents and methods used in the histology laboratory is demonstrated. After definitions of dyes, stains, and chromogenic reagents, existing standards and standards organizations are discussed. This is followed by practical instructions on how to standardize dyes...... and stains through the preparation of reference materials and the development of chromatographic methods. An overview is presented of the problems concerned with standardization of the Romanowsky-Giemsa stain for cytological and histological application. Finally, the problem of how to convince routine...... dye and stain users of the need for standardization in their histology laboratories is discussed....

  15. POCT血糖仪、生化仪葡萄糖氧化酶法和己糖激酶法检测新生儿血糖的研究%Study on Neonatal Blood Glucose Detected by POCT Glucose Meters and Biochemical Analyzer with Glucose Oxidase Method and Hexokinase Assay

    Institute of Scientific and Technical Information of China (English)

    李小斌; 杨阳; 张士朋; 贺菊晖; 郭威

    2012-01-01

    blood was collected from adult patients with hyperglycemia, normal blood glucose and hypoglycemia, 30 cases for each group and three portions for each sample of each patient. The glucose of the first potions (Group A) was detected by 8 blood glucose meters of 6 brands. The blood of the second potions (Group B) were processed to simulate neonate blood detection, that is, after centrifugation, part of the plasma was absorbed and the hematocrit was adjusted to 60%, and then the blood glucose was measured by the 8 blood glucose meters. The glucose of the third potions was measured by biochemical analyzer with hexokinase assay. In the glucose detection of neonatal blood, the glucose of capillary blood from 40 neonates with normal total bilirubin and 20 cases with elevated total bilirubin was detected by Johnson & Johnson ONE Touch Sure Step Glucose Meter, and at the same time, the glucose of their venous blood was measured by biochemical analyzer with glucose oxidase method and hexokinase assay. Results In the detection of glucose of simulated neonatal blood, glucose detected by Johnson & Johnson ONE Touch Sure Step and by Roche ACCU - CHEK Active (machine injection) with glucose oxidase enzyme photochemical method did not show any significant difference for blood from patients with hyperglycemia, normal blood glucose and hypoglycemia in the Group A (normal hematocrit) and the Group B (high hematocrit) (P>0.05), and the detection results had a good correlation with the results by biochemical analyzer with hexokinase method (r > 0.95). In the detection of neonatal blood, the test results by Johnson & Johnson ONE Touch Sure Step and by biochemical analyzer with glucose oxidase method and hexokinase assay did not indicate significant difference (P>0.05). Conclusions Concerning the capacity of the POCT glucose meters against the influence of high hematocrit, glucose oxidase photochemical method is better than the glucose oxidase electrode method and glucose dehydrogenase

  16. The correlation between dual-color chromogenic in situ hybridization and fluorescence in situ hybridization in assessing HER2 gene amplification in breast cancer

    DEFF Research Database (Denmark)

    Pedersen, Marianne; Rasmussen, Birgitte Bruun

    2009-01-01

    generated chromogenic signals are also stable. This study presents a dual color CISH for simultaneous detection of the HER2 gene and chromosome 17. The CISH method performs a chromogenic detection "on top" of the Food and Drug Administration (FDA)-approved HER2 FISH pharmDx method, where the fluorochrome...... invasive breast carcinomas, both FISH and CISH detected HER2 amplification in 24 cases and nonamplification was detected in 47 cases. One case showed a discrepancy between FISH and CISH. The concordance between CISH and FISH was found to be almost perfect (98.6%). The correlation between the HER2 ratios...

  17. Clinical and experimental evaluation of a new chromogenic medium (OCCA, Oxoid) for direct identification of Candida albicans, C. tropicalis and C. krusei.

    Science.gov (United States)

    Baixench, M T; Taillandier, A; Paugam, A

    2006-07-01

    Oxoid Chromogenic Candida Agar (OCCA) is a new commercial ready-to-use medium that contains chromogenic substrates for rapid detection and specific identification of Candida albicans, C. tropicalis and C. krusei. We evaluated the performance of this medium with 364 clinical specimens and 31 subcultures, and examined its ability to support the growth of small inocula of six reference strains. CHROMagar Candida was used as the reference medium. OCCA permitted the growth of most important yeasts, and readily discriminated among Candida spp. in clinical specimens, including mixed cultures. PMID:16784446

  18. A new chromogenic agent for iron(III): Synthesis, structure and spectroscopic studies

    Indian Academy of Sciences (India)

    Chandrama Basu; Santanu Chowdhury; Helen Stoeckli-Evans; Soma Mukherjee

    2010-03-01

    A heterocyclic hydrazone ligand, diacetyl monoxime-2-pyridyl hydrazone, HL, 1, was investigated as a new chromogenic agent for selective detection of Fe3+. The ligand 1, undergoes 1 : 2 complexation with Fe3+ and Ni2+ to form complexes [FeIII(HL)2]Cl3, 1a and [NiII(HL)2]Cl2, 1b respectively. The iron(III) complex 1a gives a characteristic absorption peak at 487 nm with distinct reddish-pink colouration. The change in colour can easily be distinguished from other metal complexes by the naked eye. No obvious interference was observed in presence of other metal ions (Na+, K+, Ca2+, Mg2+, Al3+, Mn2+, Ni2+, Cu2+, Zn2+, Co2+, Pb2+, Hg2+, Cd2+). The bands appearing in the UV region (200-340 nm) are characteristics of the ligand, HL, 1. In the complexes [FeIII(HL)2]Cl3, 1a, and [NiII(HL)2]Cl2, 1b, these ligand centered bands are accompanied by multiple bands extending into the visible region (350-500 nm). The association constants (ass, UV-Vis) were found to be (6.4865 ± 0.004) × 105 for the complex 1a and (1.1960 ± 0.002) × 105 for the complex 1b at 298 K determined by the UV-Vis spectroscopy. On excitation at 285 nm, the ligand HL, 1 strongly emits at 364 nm due to an intraligand1( - *) transition. The complexes are luminescent (ex 285 nm, em 365 nm) with /0 0.75 for 1a and 0.81 for 1b. In both the cases, the 1 : 2 binding is confirmed by Job’s method. Molecular structure of the complex 1b has been determined by single crystal X-ray diffraction studies. Here, two crystallographically distinct but metrically very similar molecules making an enantiomeric pair constitute the asymmetric unit in which both metal atoms are tris chelated in meridional geometry.

  19. Dithizone as novel and efficient chromogenic probe for cyanide detection in aqueous media through nucleophilic addition into diazenylthione moiety

    Science.gov (United States)

    Tavallali, Hossein; Deilamy-Rad, Gohar; Parhami, Abolfath; Kiyani, Sajede

    2014-03-01

    A new selective chemodosimeter probe was developed by the introduction of dithizone (DTZ) as a simple and available dye for detection of cyanide in aqueous media which enables recognition of cyanide over other competing anions such as acetate, dihydrogen phosphate, fluoride and benzoate through covalent bonding. The sensing properties of DTZ were investigated in DMSO/H2O (1:9) and have demonstrated a very high selectivity toward the cyanide anions. A reasonable recognition mechanism was suggested using UV-Vis, 1H NMR and FTIR spectroscopy techniques. Time dependent density function theory (TDDFT) computations of UV-Vis excitation for DTZ2-CN adduct agreed well with our experimental findings. The detection limit of the new chromogenic probe was measured to be 0.48 μmol L-1 which is much lower than most recently reported chromogenic probes for cyanide determination. The analytical utility of the method for the analysis of cyanide ions in electroplating wastewater (EPWW), human serum, tap and mineral water samples was demonstrated and the results were compared successfully with the conventional reference method. The short time response and the detection by the naked eye make the method available for the detection and quantitative determination of cyanide in a variety of real samples.

  20. The Anopheles punctulatus complex: DNA probes for identifying the Australian species using isotopic, chromogenic, and chemiluminescence detection systems

    International Nuclear Information System (INIS)

    Isotopic and enzyme-labeled species-specific DNA probes were made for the three known members of the Anopheles punctulatus complex of mosquitoes in Australia (Anopheles farauti Nos. 1, 2, and 3). Species-specific probes were selected by screening total genomic libraries made from the DNA of individual species with 32P-labeled DNA of homologous and heterologous mosquito species. The 32P-labeled probes for A. farauti Nos. 1 and 2 can detect less than 0.2 ng of DNA while the 32P-labeled probe for A. farauti No. 3 has a sensitivity of 1.25 ng of DNA. Probes were then enzyme labeled for chromogenic and chemiluminescence detection and compared to isotopic detection using 32P-labeled probes. Sequences of the probe repeat regions are presented. Species identifications can be made from dot blots or squashes of freshly killed mosquitoes or mosquitoes stored frozen, dried, and held at room temperature or fixed in isopropanol or ethanol with isotopic, chromogenic, or chemiluminescence detection systems. The use of nonisotopic detection systems will enable laboratories with minimal facilities to identify important regional vectors

  1. Recent abstracts in biochemical technology

    OpenAIRE

    R R Siva Kiran; Brijesh P

    2008-01-01

    “Recent abstracts in biochemical technology” is a collection of interesting research articles published in “List of biochemical technology journals” (Table 1). The abstracts are most likely to report significant results in biochemical technology.

  2. Determination of HER-2 status on FNAC material from breast carcinomas using in situ hybridization with dual chromogen visualization with silver enhancement (dual SISH

    Directory of Open Access Journals (Sweden)

    Beraki Elsa

    2010-01-01

    Full Text Available During the last years, HER-2 status kits and protocols for chromogen visualization of hybridization signals have come on the market. The first generation using chromogen visualization used single color probes. The second generation, now emerging on the market, uses dual chromogen visualization. The aim of this study has been to test a new dual color chromogen kit (Ventana INFORM HER2 Dual Colour ISH Roche ® and compare the results with our in-house method(s. The material consisted primarily of cytological material from invasive breast carcinomas in 49 women. Dual SISH was done on all 49 cytological and histological specimens. The histological specimens were treated according to the manufacturer′s recommendations. The procedure was modified in several steps in order to adapt it to the cytological material. Hybridization failed in two cytological specimens. Dual SISH showed concordant results on cytological and histological material as to amplified/not amplified. The included cases had the same HER-2 expression in the invasive and the in situ components on histology. Four IDC showed HER-2 amplification (8.5%. Polysomy was found in two cases. All dual SISH results except for one concurred with the results of the in-house method(s (1/47=2.1%. The dual SISH is suitable for cytological examination of HER-2 status. The protocol must be optimized for cytological material.

  3. Prospective evaluation of the chromogenic medium CandiSelect 4 for differentiation and presumptive identification of non-Candida albicans Candida species

    NARCIS (Netherlands)

    Zhao, Liang; de Hoog, G Sybren; Cornelissen, Akke; Lyu, Qian; Mou, Lili; Liu, Taohua; Cao, Yu; Vatanshenassan, Mansoureh; Kang, Yingqian

    2016-01-01

    Rapid identification of pathogenic yeasts is a crucial step in timely and appropriate antifungal therapy. For diagnostics in the clinical laboratory, simplified alternatives to barcoding are needed. CandiSelect 4 (CS4) medium, a chromogenic medium for isolation of clinical yeasts, allows routine rec

  4. Hormone assay

    International Nuclear Information System (INIS)

    An improved radioimmunoassay is described for measuring total triiodothyronine or total thyroxine levels in a sample of serum containing free endogenous thyroid hormone and endogenous thyroid hormone bound to thyroid hormone binding protein. The thyroid hormone is released from the protein by adding hydrochloric acid to the serum. The pH of the separated thyroid hormone and thyroid hormone binding protein is raised in the absence of a blocking agent without interference from the endogenous protein. 125I-labelled thyroid hormone and thyroid hormone antibodies are added to the mixture, allowing the labelled and unlabelled thyroid hormone and the thyroid hormone antibody to bind competitively. This results in free thyroid hormone being separated from antibody bound thyroid hormone and thus the unknown quantity of thyroid hormone may be determined. A thyroid hormone test assay kit is described for this radioimmunoassay. It provides a 'single tube' assay which does not require blocking agents for endogenous protein interference nor an external solid phase sorption step for the separation of bound and free hormone after the competitive binding step; it also requires a minimum number of manipulative steps. Examples of the assay are given to illustrate the reproducibility, linearity and specificity of the assay. (UK)

  5. Modularity of Biochemical Filtering for Inducing Sigmoid Response in Both Inputs in an Enzymatic AND Gate

    CERN Document Server

    Bakshi, Saira; Halamek, Jan; Privman, Vladimir; Katz, Evgeny

    2013-01-01

    We report the first systematic study of designed two-input biochemical systems as information processing gates with favorable noise-transmission properties accomplished by modifying the gate's response from convex shape to sigmoid in both inputs. This is realized by an added chemical "filter" process which recycles some of the output back into one of the inputs. We study a system involving the biocatalytic function of the enzyme horseradish peroxidase, functioning as an AND gate. We consider modularity properties, such as the use of three different input chromogens that, when oxidized yield signal-detection outputs for various ranges of the primary input, hydrogen peroxide. We also examine possible uses of different filter-effect chemicals (reducing agents) to induce the sigmoid-response. A modeling approach is developed and applied to our data, allowing us to describe the enzymatic kinetics in the framework of a formulation suitable for evaluating the noise-handling properties of the studied systems as logic...

  6. Changes in the chromogene properties of the betalaine; Cambios en las propiedades cromogenas de las betalainas inducidos por radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Arcos P, A.; Vega C, H.R. [Unidad Academica de Ciencias Nucleares, C. Cipres 10, Fracc. La Penuela, 98068, Zacatecas, Zac. (Mexico)

    2005-07-01

    The changes of coloration of four natural extracts were determined in function of the absorbed dose taken place by a source of rays gamma of Cs-137. The used natural extracts contain betalaine that are natural pigments of some plants as the beet root, of there their name. They are also in abundant form in the fruits (tunas) of some species of the Opuntia gender. The extracts were obtained by maceration, starting from beet root and three tuna varieties, and they were stabilized to pH 5.5 the change of coloration you determines in a spectrophotometer ultraviolet/visible by means of the absorbance from the samples to photons of 475, 535 and 600 nm of wave longitude. The absorbance was measured, to different intervals of time. The relationship settled down between the absorbed dose and the chromogene properties of the pigment, with the intention of using it as possible dosemeter. (Author)

  7. Turn-On Fluorogenic and Chromogenic Detection of Small Aromatic Hydrocarbon Vapors by a Porous Supramolecular Host.

    Science.gov (United States)

    Hatanaka, Sou; Ono, Toshikazu; Hisaeda, Yoshiio

    2016-07-18

    Benzene, toluene, ethylbenzene, the isomers of xylene, and trimethylbenzene are harmful volatile organic compounds and pose risks to human health and the environment. However, there are currently no effective chemosensors for vapors of these compounds. A porous supramolecular host for turn-on fluorogenic and chromogenic detection of the vapors of small aromatic hydrocarbons is presented. The host was constructed from a naphthalenediimide derivative that was supramolecularly connected to tris(pentafluorophenyl)borane. The amorphous powder form of the host allowed for effective accommodation of vapors of small aromatic hydrocarbons, resulting in a guest-dependent fluorescence emission. Increases in the fluorescence yield of 76-, 46-, and 37-fold were observed with toluene, benzene, and m-xylene, respectively. Negligible responses were obtained with common organic solvents. This simple supramolecular host could be applied as a useful sensor of small aromatic hydrocarbon vapors. PMID:27224939

  8. Linker-dependent chromogenic control of the emission of polymethylene-vaulted trans-bis(salicylaldiminato)platinum(II) complexes

    International Nuclear Information System (INIS)

    The emission wavelengths of polymethylene-vaulted trans-bis(salicylaldiminato)platinum(II) complexes 1a–f (n=8–13) in a 2-MeTHF glass state at 77 K clearly vary with the length of the linker, such that a very regular hypsochromic shift from yellow to green is observed upon transitioning from octamethylene (1a, n=8) to tridecamethylene (1f, n=13) linkages. This structure-dependent chromism is explained based on DFT and TD-DFT calculations comparing the T1–S0 gaps in optimized 1a, 1c (n=10) and 1e (n=12) structures. - Highlights: • Trans-bis(salicylaldiminato)platinum(II) platform with polymethylene-vaulted structures. • An unprecedented linker-dependent chromogenic control of emission. • A clear mechanistic rationale based on DFT and TD-DFT calculations

  9. A comparison of standard cultural methods for the detection of foodborne Salmonella species including three new chromogenic plating media.

    Science.gov (United States)

    Schönenbrücher, Vanessa; Mallinson, Edward T; Bülte, Michael

    2008-03-31

    In this study the draft of the horizontal method for the detection of Salmonella species from human food and animal feed (ISO 6579:2002) was compared to the European gold standard (DIN EN 12824:1998), including the three new chromogenic plating media AES Salmonella Agar Plate (ASAP), Oxoid Salmonella Chromogen Media (OSCM) and Miller-Mallinson agar (MM). First the growth and appearance of 36 bacterial type strains (Salmonella and other 21 species) on ASAP, OSCM and MM were compared to those on the three traditional agars Brilliant Green Agar according to Edel and Kampelmacher (BGA), Xylose Lysine Deoxycholate Agar (XLD) and Xylose Lysine Tergitol 4 Agar (XLT4). Only on MM agar, did all of 36 tested type strains produce typical colonies, especially strains of S. Senftenberg, Salmonella arizonae, S. Dublin and S. Derby. Artificial inoculation experiments using raw pork ground meat (n=92) were subsequently conducted. A shortened incubation time of 24 h in RVS broth yielded a Salmonella species recovery of 100% from spiked meat samples. Finally, 286 naturally contaminated raw porcine and bovine minced meat samples and raw poultry meat samples were investigated. Forty-three strains from a total of 39 Salmonella-positive samples were found. S. Typhimurium (n=21), with DT 104 L, DT 012 and RDNC being the most prevalent subtypes isolated. D-tartrate-positive S. Paratyphi B (n=2) and S. Saint-Paul (n=3) were also recovered. They were cultured from poultry meat and were multi-resistant against antibiotics including nalidixic acid. Rappaport Vassiliadis broth with soypeptone (RVS) yielded the highest recovery of Salmonella spp. (97,4%) compared to Tetrathionate broth with Novobiocin according to Muller and Kauffman (MKTTn, 94,9%) and Selenite Cystine broth (SC, 38,5%). However, no significant difference was obtained by comparing the ISO 6579:2002 draft to the gold standard. PMID:18192050

  10. Fluorogenic and chromogenic probe for rapid detection of a nerve agent simulant DCP.

    Science.gov (United States)

    Wu, Wei-hui; Dong, Jun-jun; Wang, Xin; Li, Jian; Sui, Shao-hui; Chen, Gao-yun; Liu, Ji-wei; Zhang, Ming

    2012-07-21

    A fluorogenic and visual probe was devised to detect diethyl chlorophosphate (DCP), a nerve agent simulant. The probe, N-(rhodamine B)-lactam-2-aminoethanol (RB-AE), undergoes oxazoline formation following phosphorylation in the presence of DCP, which gives rapid and clear fluorescence and color change in the assay solutions. PMID:22624148

  11. Radioreceptor assays

    International Nuclear Information System (INIS)

    Radioreceptor assay (RRA) is an analytical method using the specific interaction of some pharmaceuticals and endogenic substances (ligands) with specific receptors present in certin tissues of living organisms. RRA uses the principle of isotope dilution. The method is described in detail of the preparation of receptors, samples and radioligands, conditions of incubation, the separation of free and bound radioligand, and the mathematical evaluation of RRA. The sensitivity of RRA is measured in units to tens of pg. The specificity of RRA relates to a group of substances with similar pharmacological effect. RRA may be used for identifying neuroleptics, antidepressants, anxiolytics, ergot alkaloids, beta blockers, anticholinergic drugs, certain hormones and neuropeptides. (M.D.)

  12. Biochemical Neuroscience Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — This biochemistry lab is set up for protein analysis using Western blot, enzyme linked immunosorbent assays, immunohistochemistry, and bead-based immunoassays. The...

  13. Angiogenesis Assays.

    Science.gov (United States)

    Nambiar, Dhanya K; Kujur, Praveen K; Singh, Rana P

    2016-01-01

    Neoangiogenesis constitutes one of the first steps of tumor progression beyond a critical size of tumor growth, which supplies a dormant mass of cancerous cells with the required nutrient supply and gaseous exchange through blood vessels essentially needed for their sustained and aggressive growth. In order to understand any biological process, it becomes imperative that we use models, which could mimic the actual biological system as closely as possible. Hence, finding the most appropriate model is always a vital part of any experimental design. Angiogenesis research has also been much affected due to lack of simple, reliable, and relevant models which could be easily quantitated. The angiogenesis models have been used extensively for studying the action of various molecules for agonist or antagonistic behaviour and associated mechanisms. Here, we have described two protocols or models which have been popularly utilized for studying angiogenic parameters. Rat aortic ring assay tends to bridge the gap between in vitro and in vivo models. The chorioallantoic membrane (CAM) assay is one of the most utilized in vivo model system for angiogenesis-related studies. The CAM is highly vascularized tissue of the avian embryo and serves as a good model to study the effects of various test compounds on neoangiogenesis. PMID:26608294

  14. Thyroglobulin measurement by highly sensitive assays

    DEFF Research Database (Denmark)

    Giovanella, Luca; Feldt-Rasmussen, Ulla; Verburg, Frederik A;

    2015-01-01

    thyroglobulin (Tg), circulating Tg serves as a biochemical marker of persistent or recurrent disease in the follow-up of DTC. Due to the suboptimal clinical detection rate of older Tg assays endogenous or exogenous thyrotropin (TSH) stimulations are recommended for unmasking occult disease. However, the...... development of new Tg assays with improved analytical sensitivity and precision at low concentrations now allows detection of very low Tg concentrations, reflecting minimal amounts of thyroid tissue, even without the need for TSH stimulation. Even if the use of these assays still has not found its way in...... current clinical guidelines, such assays are now increasingly used in clinical practice. As serum Tg measurement is a technically challenging assay and criteria to define a 'highly sensitive' assay may be different, a good knowledge of the technical difficulties and interpretation criteria is of paramount...

  15. Measures of Biochemical Sociology

    Science.gov (United States)

    Snell, Joel; Marsh, Mitchell

    2008-01-01

    In a previous article, the authors introduced a new sub field in sociology that we labeled "biochemical sociology." We introduced the definition of a sociology that encompasses sociological measures, psychological measures, and biological indicators Snell & Marsh (2003). In this article, we want to demonstrate a research strategy that would assess…

  16. Biochemical Education in Brazil.

    Science.gov (United States)

    Vella, F.

    1988-01-01

    Described are discussions held concerning the problems of biochemical education in Brazil at a meeting of the Sociedade Brazileira de Bioquimica in April 1988. Also discussed are other visits that were made to universities in Brazil. Three major recommendations to improve the state of biochemistry education in Brazil are presented. (CW)

  17. A bifunctional chromogenic and fluorogenic probe for F{sup −} and Al{sup 3+} based on azo-benzimidazole conjugate

    Energy Technology Data Exchange (ETDEWEB)

    Iniya, Murugan; Jeyanthi, Dharmaraj; Krishnaveni, Karuppiah; Chellappa, Duraisamy, E-mail: dcmku123@gmail.com

    2015-01-15

    A versatile bifunctional probe has been reported for selective individual detection of Al{sup 3+} and F{sup −} through “turn-on” chromogenic and fluorogenic dual modes. The photonic behaviors of probe upon addition of analyte have been determined using UV–vis absorption, fluorescence emission, quantum yield and fluorescence life-time measurement. Density functional theory calculations have been performed to establish the nature of interaction between probe and Al{sup 3+}/F{sup −}. - Highlights: • First report on azo based bifunctional chromogenic and fluorogenic chemosensor for Al{sup 3+} and F{sup −} with varied responses. • The probe displays simple method of synthesis, reversibility towards Al{sup 3+} and high stability. • TD–DFT calculations were performed to characterize the nature of fluorescent behavior of probe upon addition of Al{sup 3+} and F{sup −}.

  18. Assessment of a new selective chromogenic Bacillus cereus group plating medium and use of enterobacterial autoinducer of growth for cultural identification of Bacillus species.

    Science.gov (United States)

    Reissbrodt, R; Rassbach, A; Burghardt, B; Rienäcker, I; Mietke, H; Schleif, J; Tschäpe, H; Lyte, M; Williams, P H

    2004-08-01

    A new chromogenic Bacillus cereus group plating medium permits differentiation of pathogenic Bacillus species by colony morphology and color. Probiotic B. cereus mutants were distinguished from wild-type strains by their susceptibilities to penicillin G or cefazolin. The enterobacterial autoinducer increased the sensitivity and the speed of enrichment of B. cereus and B. anthracis spores in serum-supplemented minimal salts medium (based on the standard American Petroleum Institute medium) and buffered peptone water. PMID:15297532

  19. Development of a chromogenic in situ hybridization for Giardia duodenalis and its application in canine, feline, and porcine intestinal tissues samples

    OpenAIRE

    Weissenböck, Herbert; Ondrovics, Martina; Gurtner, Susanne; Schiessl, Peter; MOSTEGL, MEIKE M.; Richter, Barbara

    2011-01-01

    In the present study, a chromogenic in situ hybridization for the identification of Giardia duodenalis in paraffin-embedded tissue samples was developed. The sensitivity and specificity of the probe was validated by testing it on cultured reference samples of different assemblages of G. duodenalis as well as culture and tissue samples containing other protozoa and infectious agents. The probe gave a positive reaction with the Giardia samples and a negative reaction with all other samples. Fur...

  20. Determination of Ni(II) with picolinaldehyde-4-phenyl-3-thiosemicarbazone used as a chromogenic reagent in a nonionic micellar system

    OpenAIRE

    BALOUCH, Aamna; BHANGER, Muhammad Iqbal; TALPUR, Farah Naz

    2011-01-01

    Spectrophotometric determination of Ni(II) was carried out using picolinaldehyde-4-phenyl-3-thiosemicarbazone (PAPT) as a complexing/chromogenic reagent. The possibility of using a micellar system was explored to enhance the degree of detection and allow a more sensitive spectrophotometric method for the determination of nickel ions. The anionic surfactant Triton X-100 greatly enhanced the molar absorptivity and limit of detection relative to that observed with bulk water or an organ...

  1. Radiopharmaceutical assays

    International Nuclear Information System (INIS)

    Under the laws in force, radiopharmaceuticals for human use must be among other features, non-pyrogenous and non-toxic. For this reason pyrogenity and toxicity assays are carried out. Pharmacokinetic studies may also be necessary in some cases. Products currently made at the Radiopharmaceutical Center, new products designed for certification and raw materials used to manufacture the above, were tested. A total 342 pyrogenity and toxicity tests, and four pharmacokinetic studies were conducted in 1996. To determine pyrogenity, the temperature animals were measured following intravenous administration of radiopharmaceuticals concerned: sodium pertechnetate, colloidal gold and sodium orthoradiohippurate from current production; pharmaceutic components of several new products, i.e. technetium generator, fibrinogen and microspheres. A total 327 products were tested, 96 percent of which met the requirements. To determine toxicity, the probit method was used, consisting of the administration of radiopharmaceutical doses for seven straight days, and checking for lethal effects. An overall 15 tests were carried out and 80 percent of products tested were found certifiable. Pharmacokinetic tests consisted of tropism on target organs and biodistribution in several organs using the tomographic method. (author)

  2. Multiplexing oscillatory biochemical signals.

    Science.gov (United States)

    de Ronde, Wiet; ten Wolde, Pieter Rein

    2014-04-01

    In recent years it has been increasingly recognized that biochemical signals are not necessarily constant in time and that the temporal dynamics of a signal can be the information carrier. Moreover, it is now well established that the protein signaling network of living cells has a bow-tie structure and that components are often shared between different signaling pathways. Here we show by mathematical modeling that living cells can multiplex a constant and an oscillatory signal: they can transmit these two signals simultaneously through a common signaling pathway, and yet respond to them specifically and reliably. We find that information transmission is reduced not only by noise arising from the intrinsic stochasticity of biochemical reactions, but also by crosstalk between the different channels. Yet, under biologically relevant conditions more than 2 bits of information can be transmitted per channel, even when the two signals are transmitted simultaneously. These observations suggest that oscillatory signals are ideal for multiplexing signals. PMID:24685537

  3. Estrogen and progesterone receptors in endometrial carcinoma: comparison of immunohistochemical and biochemical analysis

    DEFF Research Database (Denmark)

    Nyholm, H C; Nielsen, Anette Lynge; Lyndrup, J;

    1993-01-01

    In 159 endometrial carcinomas, estrogen (ER) and progesterone receptors (PR) were determined biochemically by dextran-coated charcoal (DCC) assay and immunohistochemically (ICA) on frozen sections. ICA receptor content was estimated by a total histologic score (HSCORE), including all tissue...

  4. Assays for Determination of Protein Concentration.

    Science.gov (United States)

    Olson, Bradley J S C

    2016-01-01

    Biochemical analysis of proteins relies on accurate quantification of protein concentration. Detailed in this appendix are some commonly used methods for protein analysis, e.g., Lowry, Bradford, bicinchoninic acid (BCA), UV spectroscopic, and 3-(4-carboxybenzoyl)quinoline-2-carboxaldehyde (CBQCA) assays. The primary focus of this report is assay selection, emphasizing sample and buffer compatibility. The fundamentals of generating protein assay standard curves and of data processing are considered, as are high-throughput adaptations of the more commonly used protein assays. Also included is a rapid, inexpensive, and reliable BCA assay of total protein in SDS-PAGE sample buffer that is used for equal loading of SDS-PAGE gels. © 2016 by John Wiley & Sons, Inc. PMID:27248579

  5. Presumptive identification of Candida species other than C. albicans, C. krusei, and C. tropicalis with the chromogenic medium CHROMagar Candida

    Directory of Open Access Journals (Sweden)

    Horvath Lynn L

    2006-01-01

    Full Text Available Abstract Background CHROMagar Candida (CaC is increasingly being reported as a medium used to differentiate Candida albicans from non-albicans Candida (NAC species. Rapid identification of NAC can assist the clinician in selecting appropriate antifungal therapy. CaC is a differential chromogenic medium designed to identify C. albicans, C. krusei, and C. tropicalis based on colony color and morphology. Some reports have proposed that CaC can also reliably identify C. dubliniensis and C. glabrata. Methods We evaluated the usefulness of CaC in the identification of C. dubliniensis, C. famata, C. firmetaria, C. glabrata, C. guilliermondii, C. inconspicua, C. kefyr, C. lipolytica, C. lusitaniae, C. norvegensis, C. parapsilosis, and C. rugosa. Results Most NAC produced colonies that were shades of pink, lavender, or ivory. Several isolates of C. firmetaria and all C. inconspicua produced colonies difficult to differentiate from C. krusei. Most C. rugosa isolates produced unique colonies with morphology like C. krusei except in a light blue-green color. C. glabrata isolates produced small dark violet colonies that could be differentiated from the pink and lavender colors produced by other species. All seventeen isolates of C. dubliniensis produced green colonies similar to those produced by C. albicans. Conclusion C. glabrata and C. rugosa appear distinguishable from other species using CaC. Some NAC, including C. firmetaria and C. inconspicua, could be confused with C. krusei using this medium.

  6. Chromogenic in situ hybridization compared with other approaches to evaluate HER2/neu status in breast carcinomas

    International Nuclear Information System (INIS)

    Human epidermal growth factor receptor 2 (HER2) has been evaluated in breast cancer patients to identify those most likely to benefit from herceptin-targeted therapy. HER2 amplification, detected in 20-30% of invasive breast tumors, is associated with reduced survival and metastasis. The most frequently used technique for evaluating HER2 protein status as a routine procedure is immunohistochemistry (IHC). HER2 copy number alterations have also been evaluated by fluorescence in situ hybridization (FISH) in moderate immunoexpression (IHC 2+) cases. An alternative procedure to evaluate gene amplification is chromogenic in situ hybridization (CISH), which has some advantages over FISH, including the correlation between HER2 status and morphological features. Other methodologies have also been used, such as silver-enhanced in situ hybridization (SISH) and quantitative real-time RT-PCR, to determine the number of HER2 gene copies and expression, respectively. Here we will present a short and comprehensive review of the current advances concerning HER2 evaluation in human breast cancer

  7. Chromogenic in situ hybridization compared with other approaches to evaluate HER2/neu status in breast carcinomas

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, F.E.; Santos, R.M. [Departamento de Patologia, Hospital das Clínicas, Faculdade de Medicina, Universidade Estadual Paulista, Botucatu, SP (Brazil); Rogatto, S.R. [Departamento de Urologia, Faculdade de Medicina, Universidade Estadual Paulista, Botucatu, SP (Brazil); Hospital A.C. Camargo, CIPE, São Paulo, SP (Brazil); Domingues, M.A.C. [Departamento de Patologia, Faculdade de Medicina, Universidade Estadual Paulista, Botucatu, SP (Brazil)

    2013-03-19

    Human epidermal growth factor receptor 2 (HER2) has been evaluated in breast cancer patients to identify those most likely to benefit from herceptin-targeted therapy. HER2 amplification, detected in 20-30% of invasive breast tumors, is associated with reduced survival and metastasis. The most frequently used technique for evaluating HER2 protein status as a routine procedure is immunohistochemistry (IHC). HER2 copy number alterations have also been evaluated by fluorescence in situ hybridization (FISH) in moderate immunoexpression (IHC 2+) cases. An alternative procedure to evaluate gene amplification is chromogenic in situ hybridization (CISH), which has some advantages over FISH, including the correlation between HER2 status and morphological features. Other methodologies have also been used, such as silver-enhanced in situ hybridization (SISH) and quantitative real-time RT-PCR, to determine the number of HER2 gene copies and expression, respectively. Here we will present a short and comprehensive review of the current advances concerning HER2 evaluation in human breast cancer.

  8. Chromogenic behaviors of the Humboldt squid (Dosidicus gigas) studied in situ with an animal-borne video package.

    Science.gov (United States)

    Rosen, Hannah; Gilly, William; Bell, Lauren; Abernathy, Kyler; Marshall, Greg

    2015-01-15

    Dosidicus gigas (Humboldt or jumbo flying squid) is an economically and ecologically influential species, yet little is known about its natural behaviors because of difficulties in studying this active predator in its oceanic environment. By using an animal-borne video package, National Geographic's Crittercam, we were able to observe natural behaviors in free-swimming D. gigas in the Gulf of California with a focus on color-generating (chromogenic) behaviors. We documented two dynamic displays without artificial lighting at depths of up to 70 m. One dynamic pattern, termed 'flashing' is characterized by a global oscillation (2-4 Hz) of body color between white and red. Flashing was almost always observed when other squid were visible in the video frame, and this behavior presumably represents intraspecific signaling. Amplitude and frequency of flashing can be modulated, and the phase relationship with another squid can also be rapidly altered. Another dynamic display termed 'flickering' was observed whenever flashing was not occurring. This behavior is characterized by irregular wave-like activity in neighboring patches of chromatophores, and the resulting patterns mimic reflections of down-welled light in the water column, suggesting that this behavior may provide a dynamic type of camouflage. Rapid and global pauses in flickering, often before a flashing episode, indicate that flickering is under inhibitory neural control. Although flashing and flickering have not been described in other squid, functional similarities are evident with other species. PMID:25609785

  9. Antibody-Free Colorimetric Detection of Total Aflatoxins in Rice Based on a Simple Two-Step Chromogenic Reaction.

    Science.gov (United States)

    Du, Bibai; Su, Xiaoou; Yang, Kunhao; Pan, Long; Liu, Qingju; Gong, Lingling; Wang, Peilong; Yang, Jingkui; He, Yujian

    2016-04-01

    The prevalently used immunoassays for fast screening of aftatoxins (AFs) usually cannot meet the requirement for simultaneous determination of total AFs (aflatoxin B1 + aflatoxin B2 + aflatoxin G1 + aflatoxin G2) due to the deficiency of highly group-specific antibodies. This paper describes a two-step chromogenic reaction based method to quantitatively detect total AFs in rice using colorimetric measurement without antibody. In the method, colorless AFs transform into green-colored indophenol products through the reaction with sodium hydroxide and 2,6-dibromoquinone-4-chloroimide (DBQC) successively, allowing selectively determining total AFs up to 3.9 μg/kg over other competitive mycotoxins under optimal conditions by a UV-vis spectrophotometer. In addition, the colorimetric measurement results of the rice samples agree well with that of a standard HPLC method, demonstrating the good reliability and applicability of the method. Uniquely, the method has potential for on-site detection of total AFs in rice when using a nylon membrane-based device. PMID:26938207

  10. New chromogens of the ferroin type-VII Some 3-substituted-1,2,4-triazines, 3,5-disubstituted-1,2,4-triazolines and triazoles, and 2,4- and 2,6-bis triazinyl and triazolinyl substituted pyridines.

    Science.gov (United States)

    Schilt, A A; Chriswell, C D; Fang, T A

    1974-08-01

    Chelation and chromogenic properties of 39 new ferroin compounds in reactions with iron(II), copper(I), and cobalt(II) have been investigated spectrophotometrically. The results demonstrate that the chromogenic properties of triazole and triazoline heterocycles are inferior to triazine and pyridine when incorporated into the ferroin chromophore grouping. The triazole and triazoline compounds also undergo hydrolytic decomposition, strongly catalysed by iron(II), making them unsuitable as colorimetric reagents. An outstanding chromogen was found from among the triazine derivatives which is superior in sensitivity to all ferroin-type chromogens previously studied. PMID:18961539

  11. Biochemical Hypermedia: Galactose Metabolism.

    Directory of Open Access Journals (Sweden)

    J.K. Sugai

    2013-05-01

    Full Text Available Introduction: Animations of biochemical processes and virtual laboratory environments lead to true molecular simulations. The use of interactive software’s in education can improve cognitive capacity, better learning and, mainly, it makes information acquisition easier. Material and Methods: This work presents the development of a biochemical hypermedia to understanding of the galactose metabolism. It was developed with the help of concept maps, ISIS Draw, ADOBE Photoshop and FLASH MX Program. Results and Discussion: A step by step animation process shows the enzymatic reactions of galactose conversion to glucose-1-phosphate (to glycogen synthesis, glucose-6-phosphate (glycolysis intermediary, UDP-galactose (substrate to mucopolysaccharides synthesis and collagen’s glycosylation. There are navigation guide that allow scrolling the mouse over the names of the components of enzymatic reactions of via the metabolism of galactose. Thus, explanatory text box, chemical structures and animation of the actions of enzymes appear to navigator. Upon completion of the module, the user’s response to the proposed exercise can be checked immediately through text box with interactive content of the answer. Conclusion: This hypermedia was presented for undergraduate students (UFSC who revealed that it was extremely effective in promoting the understanding of the theme.

  12. Chromogenic in situ hybridization (CISH): a novel alternative in screening archival breast cancer tissue samples for HER-2/neu status

    International Nuclear Information System (INIS)

    Chromogenic in situ hybridization (CISH) is emerging as a practical, cost-effective, and valid alternative to fluorescent in situ hybridization in testing for gene alteration, especially in centers primarily working with immunohistochemistry (IHC). We assessed Her-2/neu alteration using CISH on formalin-fixed paraffin-embedded primary invasive ductal carcinoma tumors in which IHC (CB11 antibody) had previously been performed, and we compared the results with IHC. The 160 selected cases were equally stratified randomly into the four IHC categories (scores of 0, 1+, 2+, and 3+). We also compared age at diagnosis and tumor histologic grade with IHC and CISH Her-2/neu. We were able to perform and evaluate CISH successfully on all cases. The agreement between 3+ IHC and CISH-amplified cases as well as between all IHC and CISH Her-2/neu negative cases was 100%, and the concordance on all positive cases was 72.50%, with an overall agreement of 86.25%. All the discordant cases had 2+ IHC scores. Although we noted Her-2/neu positivity more in premenopausal women, the age at diagnosis was not significantly associated with IHC or CISH results. Similarly, although the small group of well-differentiated tumors was apparently Her-2/neu negative in both tests, no significant association was noted between any tumor histologic grade and either IHC or CISH results. CISH is easily integrated into routine testing in our laboratory. It is a necessary adjunct in determining the subset of non-amplified IHC-positive invasive tumors that will not benefit from trastuzumab therapy. Those cases with 2+ IHC results will be triaged and subjected to CISH. Her-2/neu testing should be done on all breast cancer cases regardless of age at presentation and tumor histologic grade

  13. Comparison of selective agars recommended by method ISO 11290-1 and chromogenic agars for the isolation of Listeria sp. in refrigerated sausages

    Directory of Open Access Journals (Sweden)

    Thalyta Marina Benetti

    2012-12-01

    Full Text Available The aim of this study was to determine the prevalence of Listeria sp. in refrigerated sausages, and to compare the performance of the selective plating media employed in the ISO 11290-1 method (PALCAM and Oxford agars with chromogenic agars (Chromogenic Listeria agars CM 1080 (OCLA and CM 1084. The prevalence of Listeria sp. detected was 52.9%, comprising 13.7% L. monocytogenes strains. The efficacy of the four agars for the isolation of L. monocytogenes proved to be satisfactory. Despite differences in composition of the chromogenic media assessed, these disparities did not affect concordance among results. However, PALCAM agar was shown to suppress other microorganisms more effectively, being more applicable for detecting Listeria strains present in lower quantities. Based on these results, the use of PALCAM agar, in combination with a chromogenic media, is recommended for enhanced isolation of atypical Listeria sp. strains in meat products.Este estudo teve como objetivo a análise da prevalência de Listeria sp. em linguiças resfriadas e a comparação dos meios seletivos utilizados no plaqueamento do método ISO 11290-1 (Ágar PALCAM e Ágar Oxford, e ágares cromogênicos (Ágares Listeria Cromogênico CM 1080 (OCLA e CM 1084 (ISO. A frequência de Listeria sp. foi de 52,9%, sendo que destas, 13,7% corresponderam à L. monocytogenes. A eficácia dos quatro ágares para o isolamento de L. monocytogenes demonstrou-se satisfatória. Apesar de haver algumas diferenças nas composições dos meios cromogênicos analisados, estas não pareceram influenciar nas concordâncias entre os resultados expressos. Contudo, o ágar PALCAM mostrou-se mais eficaz na supressão de outros micro-organismos, aumentando, assim, a possibilidade de detecção de espécies de Listeria presentes em número reduzido. Através deste trabalho sugere-se a utilização do ágar PALCAM associado a um meio cromogênico para aumentar a chance de isolamento de cepas at

  14. Biochemical synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Descriptions of the biochemical synthesis of glucose-13C6 from Agmenellum quadruplication; the biochemical labelling of [13C, 15N] Chlorella and [13C] E. coli, [15N] E. coli, and the production of lactic-13C3 acid utilizing Lactobacillus casei are discussed

  15. EVALUATING BIOCHEMICAL INTERNET RESOURCES

    Directory of Open Access Journals (Sweden)

    R.M. Lima

    2007-05-01

    Full Text Available Many people fail to properly evaluate INTERNET information. This is often due to alack of understanding of the issues, by responsible authorities, and, morespecifically, a lack of understanding of the structure and modis operandi of theINTERNET tool. The aim of this project was to analyze biochemical issuesavailable in WEB pages, evaluating contents quality, coverage, accuracy, authorityand currency. Twenty three sites were analyzed for their contents, presence ofbibliographical references, authorship, titles responsibility and adequacy to targetpublic. The great majority (95% did not mention bibliographic references andtarget public. Less than half divulged names and/or graduation status ofresponsibles. Some sites contained critical conceptual errors, such as: oxygen isessential for anaerobic respiration; presence of H2O in photosynthesis dark phase;yeast is a pluricellular fungal; the overall equation of photosynthesis with errors;NADH2 instead NAD+; etc. None of the analyzed sites was thus consideredexcellent. Although the use of the internet is expanding rapidly on collegecampuses, little is known about students usage; how they perceive the reality ofinternet information and how successful they are in searching through it. Our datastrenghthen the need for rigorous evaluation concerning to educational research ofbiochemical themes on the WEB.

  16. A rapid kinetic chromogenic method for quantification of bacterial endotoxins in lyophilized reagents for labeling with 99mTc radiopharmaceuticals

    International Nuclear Information System (INIS)

    A rapid quantitative kinetic chromogenic test in an automated Portable Test System (PTS) has been developed for determination of bacterial endotoxins in water, in-process and end-products using the Limulus amebocyte lysate (LAL). The aim of this work was to validate the method for lyophilized reagents for labeling with 99mTc radiopharmaceuticals with no interfering factors. Experiments were performed in three consecutive batches of the lyophilized reagents Methylenediphosphonic Acid (MDP) and Pyrophosphate (PYRO) produced at IPEN-CNEN/ SP using the PTS from Endosafe, Inc.TM, Charleston, SC. The Maximum Valid Dilution (MVD) was calculated to establish the extent of dilution to avoid interfering test conditions (MVD=500). Better results were obtained above 1:20 dilution factor for MDP and 1:100 for PYRO. The parameters of coefficient correlation (R) -0.980, RPPC between 50 - 200% and coefficient variation (CV) of the samples less than 25% were satisfied and the endotoxin concentration was lower than the lowest concentration of the standard curve (0.05 EU mL-1), therefore less than the established limit in pharmacopoeias. The PTS is a rapid, simple and accurate technique using the quantitative kinetic chromogenic method for bacterial endotoxin determination. For this reason, it is very practical in the radiopharmaceutical area and it trends to be the method of choice for the pyrogen test. For MDP and PYRO, the validation was successfully performed. (author)

  17. Acromegaly Clinical Trial Methodology Impact on Reported Biochemical Efficacy Rates of Somatostatin Receptor Ligand Treatments: A Meta-Analysis

    OpenAIRE

    CARMICHAEL, JOHN D.; Bonert, Vivien S.; Nuño, Miriam; Ly, Diana; Melmed, Shlomo

    2014-01-01

    Introduction: Biochemical efficacy of somatostatin receptor ligand (SRL) treatment in acromegaly is defined by metrics for GH and IGF-1 control. Since the earliest therapeutic trials, biochemical control criteria, medical formulations, and assay techniques have evolved. Materials and Methods: We searched PubMed for English-language trials published from 1974 to 2012 evaluating 10 or more patients, with a duration of more than 3 months and biochemical control as a key objective. We used a rand...

  18. An aptamer assay using rolling circle amplification coupled with thrombin catalysis for protein detection.

    Science.gov (United States)

    Guo, Limin; Hao, Lihua; Zhao, Qiang

    2016-07-01

    We describe a sensitive aptamer-based sandwich assay for protein detection on microplate by using rolling circle amplification (RCA) coupled with thrombin catalysis. This assay takes advantage of RCA generating long DNA oligonucleotides with repeat thrombin-binding aptamer sequence, specific aptamer affinity binding to achieve multiple thrombin labeling, and enzyme activity of thrombin for signal generation. Protein target is specifically captured by antibody-coated microplate. Then, an oligonucleotide containing an aptamer for protein and a primer sequence is added to form a typical sandwich structure. Following a template encoded with complementary sequence of aptamer for thrombin, RCA reaction extends the primer sequence into a long oligonucleotide. Many thrombin molecules bind with the RCA product. Thrombin catalyzes the conversion of its chromogenic or fluorogenic peptide substrates into detectable products for final quantification of protein targets. We applied this strategy to the detection of a model protein target, platelet-derived growth factor-BB (PDGF-BB). Due to double signal amplifications from RCA and thrombin catalysis, this assay enabled the detection of PDGF-BB as low as 3.1 pM when a fluorogenic peptide substrate was used. This assay provides a new way for signal generation in RCA-involved assay through direct thrombin labeling, circumventing time-consuming preparation of enzyme-conjugate and affinity probes. This method has promise for a variety of analytical applications. PMID:27108282

  19. Enzyme and biochemical producing fungi

    DEFF Research Database (Denmark)

    Lübeck, Peter Stephensen; Lübeck, Mette; Nilsson, Lena;

    2010-01-01

    factories for sustainable production of important molecules. For developing fungi into efficient cell factories, the project includes identification of important factors that control the flux through the pathways using metabolic flux analysis and metabolic engineering of biochemical pathways....

  20. Ouroboros - Playing A Biochemical

    Directory of Open Access Journals (Sweden)

    D. T. Rodrigues

    2014-08-01

    Full Text Available Ouroboros: Playing A Biochemical RODRIGUES,D.T.1,2;GAYER, M.C.1,2; ESCOTO, D.F.1; DENARDIN, E.L.G.2, ROEHRS, R.1,2 1Interdisciplinary Research Group on Teaching Practice, Graduate Program in Biochemistry, Unipampa, RS, Brazil 2Laboratory of Physicochemical Studies and Natural Products, Post Graduate Program in Biochemistry, Unipampa, RS, Brazil Introduction: Currently, teachers seek different alternatives to enhance the teaching-learning process. Innovative teaching methodologies are increasingly common tools in educational routine. The use of games, electronic or conventional, is an effective tool to assist in learning and also to raise the social interaction between students. Objective: In this sense our work aims to evaluate the card game and "Ouroboros" board as a teaching and learning tool in biochemistry for a graduating class in Natural Sciences. Materials and methods: The class gathered 22 students of BSc in Natural Sciences. Each letter contained a question across the board that was drawn to a group to answer within the allotted time. The questions related concepts of metabolism, organic and inorganic chemical reactions, bioenergetics, etc.. Before the game application, students underwent a pre-test with four issues involving the content that was being developed. Soon after, the game was applied. Then again questions were asked. Data analysis was performed from the ratio of the number of correct pre-test and post-test answers. Results and discussion: In the pre-test 18.1% of the students knew all issues, 18.1% got 3 correct answers, 40.9% answered only 2 questions correctly and 22.7% did not hit any. In post-test 45.4% answered all the questions right, 31.8% got 3 questions and 22.7% got 2 correct answers. The results show a significant improvement of the students about the field of content taught through the game. Conclusion: Generally, traditional approaches of chemistry and biochemistry are abstract and complex. Thus, through games

  1. Comet assay to measure DNA repair: approach and applications

    OpenAIRE

    Azqueta, Amaya; SLYSKOVA, JANA; Langie, Sabine A. S.; O’Neill Gaivão, Isabel; Collins, Andrew

    2014-01-01

    Cellular repair enzymes remove virtually all DNA damage before it is fixed; repair therefore plays a crucial role in preventing cancer. Repair studied at the level of transcription correlates poorly with enzyme activity, and so assays of phenotype are needed. In a biochemical approach, substrate nucleoids containing specific DNA lesions are incubated with cell extract; repair enzymes in the extract induce breaks at damage sites; and the breaks are measured with the comet assay. The nature of ...

  2. Evaluation of chromogenic medium and direct latex agglutination test for detection of group B streptococcus in vaginal specimens from pregnant women in Lebanon and Kuwait.

    Science.gov (United States)

    Ghaddar, Nahed; Alfouzan, Wadha; Anastasiadis, Elie; Al Jiser, Tamima; Itani, Saad Eddine; Dernaika, Racha; Eid, Toufic; Ghaddar, Ali; Charafeddine, Adib; Dhar, Rita; El Hajj, Hiba

    2014-10-01

    This study was undertaken to evaluate chromogenic medium and a direct latex agglutination test (DLA) for detection of Group B Streptococcus (GBS) in the vaginal specimens of pregnant women, and to ascertain the prevalence of GBS in this population in Kuwait and Lebanon. Vaginal swabs, collected from women at 35-37 weeks of gestation, were cultured on 5 % sheep blood agar (SBA), colistin nalidixic acid agar (CNA), Strept B Select chromogenic agar (SBS) as well as Lim enrichment broth in 168 cases in Lebanon while only SBA was used for 1391 samples in Kuwait. In addition, vaginal samples from 102 GBS-positive and 20 GBS-negative women near the time of delivery were collected in Kuwait for evaluation of the DLA test. During the study period, the prevalence of GBS colonization was determined to be 20.7 % (288/1391) in Kuwait while 18.4 % (31) of 168 pregnant women in Lebanon had vaginal cultures positive for GBS. By direct plating of vaginal swabs on the three media used, the isolation rates of GBS were 51.6, 64.5 and 77.4 % on SBA, CNA and SBS, respectively, which increased to 90.35, 93.1 and 96.8 %, respectively, following subculture in Lim broth after 18 h of incubation. The sensitivity of the DLA test was found to be dependent on the density of GBS colonization, resulting in 100 % sensitivity and 100 % specificity for heavy (>10(2) c.f.u. per swab) and moderately heavy (50-100 c.f.u. per swab) growth of GBS. However, for vaginal specimens yielding DLA test were 100, 55.5, 63.6 and 100 %, respectively. In conclusion, a chromogenic agar, such as SBS, and a DLA test can be used for rapid detection of GBS in pregnant women. The DLA test, in particular, could prove to be a useful tool for immediate detection of GBS in women near delivery so that intrapartum antibiotic prophylaxis can be initiated. PMID:25082944

  3. Double-staining chromogenic in situ hybridization as a useful alternative to split-signal fluorescence in situ hybridization in lymphoma diagnostics

    DEFF Research Database (Denmark)

    van Rijk, A.; Svenstroup-Poulsen, T.; Jones, M.;

    2010-01-01

    Background Malignant lymphomas are classified based on morphology, immunophenotype, genetics and clinical features. The pathological diagnosis is generally considered difficult and prone to mistakes. Since non-random chromosomal translocations are specifically involved in specific entities, their...... detection is an important adjunct for increasing the reliability of the diagnosis. Recently, split-signal fluorescence hi situ hybridization has become available as a robust method to detect chromosomal breaks in paraffin-embedded formalin-fixed tissues. A bright field approach would bring this technology...... within the reach of every pathology laboratory. Design and Methods Our study was initiated to determine the consistency between chromogenic in situ hybridization and fluorescence in situ hybridization, both using split-signal probes developed for the detection of chromosomal breaks. Five hundred and...

  4. Changes in the chromogen properties of the betalaine induced by gamma radiation; Cambios en las propiedades cromogenas de las betalainas inducidos por radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Arcos P, A.; Vega C, H.R. [Unidad Academica de Ciencias Nucleares, C. Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2005-07-01

    The changes of coloration of four natural extracts in function of the absorbed dose produced by a gamma rays source of {sup 137} Cs were determined. The natural extracts used contain betalaines that are natural pigments of some plants as the beet about that their name. They are also in abundant form in the fruits (tunas) of some species of the Opuntia genus. The extracts were obtained by maceration, starting from beet and three tuna varieties, and they were stabilized to pH 5.5 The change of coloration it was determined in a visible ultraviolet spectrophotometer by means of the absorbance from the samples to photons of 475, 535 and 600 nm of wavelength. The absorbance to different intervals of time was measured. The relationship between the absorbed dose and the chromogene properties of the pigment, with the intention of using it as possible dosemeter was settled down. (Author)

  5. New chromogens of the ferroin type-VIII Some di- and trisubstituted 1,2,4-triazines, 3-substituted-9H-indeno[1,2-e]-1,2,4-triazin-9-ones, and di- and trisubstituted 1,2,4-triazolines.

    Science.gov (United States)

    Schilt, A A; Yang, T A; Wu, J F; Nitzki, D M

    1977-11-01

    Thirty-six new ferroin compounds have been investigated as possible chelation regents for the calorimetric detection and determination of trace amounts of iron(II), copper(I), and cobalt(II). Spectral data, solution conditions favourable for chelate formation, and other data are reported. The results reveal that incorporation of triazoline heterocycles in ferroin chromophore groupings generally leads to poor chromogenic properties, except with respect to cobalt. Triazine groups, however, can give rise to superior properties. The most sensitive iron(II) chromogen of the ferroin type found to date and a promising new cobalt chromogen are described. PMID:18962176

  6. Expression and partial biochemical characterization of a recombinant serine protease from Bothrops pauloensis snake venom.

    Science.gov (United States)

    Isabel, Thais F; Costa, Guilherme Nunes Moreira; Pacheco, Isabela B; Barbosa, Luana G; Santos-Junior, Célio D; Fonseca, Fernando P P; Boldrini França, Johara; Henrique-Silva, Flávio; Yoneyama, Kelly A G; Rodrigues, Renata S; Rodrigues, Veridiana de Melo

    2016-06-01

    Snake venom serine proteases (SVSPs) are enzymes capable of interfering at several points of hemostasis. Some serine proteases present thrombin-like activity, which makes them targets for the development of therapeutics agents in the treatment of many hemostatic disorders. In this study, a recombinant thrombin-like serine protease, denominated rBpSP-II, was obtained from cDNA of the Bothrops pauloensis venom gland and was characterized enzymatically and biochemically. The enzyme rBpSP-II showed clotting activity on bovine plasma and proteolytic activity on fibrinogen, cleaving exclusively the Aα chain. The evaluation of rBpSP-II activity on chromogenic substrates demonstrated thrombin-like activity of the enzyme due to its capacity to hydrolyze the thrombin substrate. These characteristics make rBpSP-II an attractive molecule for additional studies. Further research is needed to verify whether rBpSP-II can serve as a template for the synthesis of therapeutic agents to treat hemostatic disorders. PMID:26965926

  7. Comparison of chromogenic Biolog Rainbow agar Shigella/Aeromonas with xylose lysine desoxycholate agar for isolation and detection of Shigella spp. from foods.

    Science.gov (United States)

    Zhang, Guodong; Lampel, Keith A

    2010-08-01

    Shigella outbreaks are widely reported throughout the world. However, it remains a challenge to isolate Shigella spp. from foods by using conventional microbiological media. The main objective of this study was to determine the effectiveness of a novel chromogenic medium, Rainbow agar Shigella/Aeromonas (Rainbow agar), for the isolation and detection of Shigella spp. in foods. All four Shigella species, S. sonnei, S. flexneri, S. dysenteriae, and S. boydii, were studied. Rainbow agar was compared with tryptic soy agar, xylose lysine desoxycholate agar (XLD), and Salmonella Shigella agar (SSA) for enumeration of Shigella spp. in pure culture. This chromogenic agar and XLD were also used to isolate Shigella spp. in artificially contaminated foods (4.8 log CFU/g of food), including lettuce, parsley, cilantro, spinach, potato salad, and shrimp. The inhibitory effect on Shigella growth by Rainbow agar was between that of XLD and SSA. All vegetables studied showed a moderately high background microflora on XLD and Rainbow agar. With artificially inoculated produce, Rainbow agar recovered about 1 to 2 log CFU more S. sonnei, S. dysenteriae, and S. boydii per g of food than did XLD. For potato salad and shrimp, which had low background microflora on Rainbow agar, Rainbow agar was slightly better in recovering Shigella spp. than XLD was in most cases. However, we found that the addition of streptomycin (6.25 mg/liter) to Rainbow agar could facilitate the isolation of Shigella in vegetables tested. In conclusion, Rainbow agar was a much more effective medium than was XLD for the isolation of Shigella spp. from foods. PMID:20819355

  8. Microbead agglutination based assays

    KAUST Repository

    Kodzius, Rimantas

    2013-01-21

    We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling the macroscopic observation. Such tests are most often used to explore antibody-antigen reactions. Agglutination has been used for protein assays using a biotin/streptavidin system as well as a hybridization based assay. The agglutination systems are prone to selftermination of the linking analyte, prone to active site saturation and loss of agglomeration at high analyte concentrations. We investigated the molecular target/ligand interaction, explaining the common agglutination problems related to analyte self-termination, linkage of the analyte to the same bead instead of different microbeads. We classified the agglutination process into three kinds of assays: a two- component assay, a three-component assay and a stepped three- component assay. Although we compared these three kinds of assays for recognizing DNA and protein molecules, the assay can be used for virtually any molecule, including ions and metabolites. In total, the optimized assay permits detecting analytes with high sensitivity in a short time, 5 min, at room temperature. Such a system is appropriate for POC testing.

  9. Radioreceptor opioid assay

    International Nuclear Information System (INIS)

    A radioreceptor assay is described for assaying opioid drugs in biological fluids. The method enables the assay of total opioid activity, being specific for opioids as a class but lacking specificity within the class. A radio-iodinated opioid and the liquid test sample are incubated with an opiate receptor material. The percentage inhibition of the binding of the radio-iodinated compound to the opiate receptor is calculated and the opioid activity of the test liquid determined from a standard curve. Examples of preparing radio-iodinated opioids and assaying opioid activity are given. A test kit for the assay is described. Compared to other methods, this assay is cheap, easy and rapid. (U.K.)

  10. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  11. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  12. Tricyclic antidepressant radioreceptor assay

    International Nuclear Information System (INIS)

    A receptor assay for tricyclic antidepressants described here is based on the ability of these drugs to compete with [3H]-3-guinuclidnyl benzilate (3H-QNB) for binding to muscarinic cholinergic receptors in rat brain membranes. The assay is sensitive, in that it can detect, for example, 2ng/ml nortriptyline in plasma. Seven plasma samples from depressed patients treated with nortriptyline were assayed with the radioreceptor and gas liquid chromatographic methods, and the results from these two methods were almost identical. This assay should be used cautiously, if at all, in patients treated with other drugs that have potent anticholinergic effects. (Auth.)

  13. Biochemical Characterization of Prion Strains in Bank Voles

    Directory of Open Access Journals (Sweden)

    Romolo Nonno

    2013-07-01

    Full Text Available Prions exist as different strains exhibiting distinct disease phenotypes. Currently, the identification of prion strains is still based on biological strain typing in rodents. However, it has been shown that prion strains may be associated with distinct PrPSc biochemical types. Taking advantage of the availability of several prion strains adapted to a novel rodent model, the bank vole, we investigated if any prion strain was actually associated with distinctive PrPSc biochemical characteristics and if it was possible to univocally identify strains through PrPSc biochemical phenotypes. We selected six different vole-adapted strains (three human-derived and three animal-derived and analyzed PrPSc from individual voles by epitope mapping of protease resistant core of PrPSc (PrPres and by conformational stability and solubility assay. Overall, we discriminated five out of six prion strains, while two different scrapie strains showed identical PrPSc types. Our results suggest that the biochemical strain typing approach here proposed was highly discriminative, although by itself it did not allow us to identify all prion strains analyzed.

  14. A click chemistry-based microRNA maturation assay optimized for high-throughput screening.

    Science.gov (United States)

    Lorenz, Daniel A; Garner, Amanda L

    2016-07-01

    Catalytic enzyme-linked click-chemistry assays (cat-ELCCA) are an emerging class of biochemical assay. Herein we report on expanding the toolkit of cat-ELCCA to include the kinetically superior inverse-electron demand Diels-Alder (IEDDA) reaction. The result is a technology with improved sensitivity and reproducibility, enabling automated high-throughput screening. PMID:27284591

  15. A novel live cell assay to measure diacylglycerol lipase α activity.

    Science.gov (United States)

    Singh, Praveen K; Markwick, Rachel; Howell, Fiona V; Williams, Gareth; Doherty, Patrick

    2016-06-01

    Diacylglycerol lipase α (DAGLα) hydrolyses DAG to generate the principal endocannabinoid (eCB) 2-arachidonoylglycerol (2-AG) in the central nervous system. DAGLα dependent cannabinoid (CB) signalling has been implicated in numerous processes including axonal growth and guidance, adult neurogenesis and retrograde signalling at the synapse. Recent studies have implicated DAGLα as an emerging drug target for several conditions including pain and obesity. Activity assays are critical to the drug discovery process; however, measurement of diacylglycerol lipase (DAGL) activity using its native substrate generally involves low-throughput MS techniques. Some relatively high-throughput membrane based assays utilizing surrogate substrates have been reported, but these do not take into account the rate-limiting effects often associated with the ability of a drug to cross the cell membrane. In the present study, we report the development of a live cell assay to measure DAGLα activity. Two previously reported DAGLα surrogate substrates, p-nitrophenyl butyrate (PNPB) and 6,8-difluoro-4-methylumbelliferyl octanoate (DiFMUO), were evaluated for their ability to detect DAGLα activity in live cell assays using a human cell line stably expressing the human DAGLα transgene. Following optimization, the small molecule chromogenic substrate PNPB proved to be superior by providing lower background activity along with a larger signal window between transfected and parental cells when compared with the fluorogenic substrate DiFMUO. The assay was further validated using established DAGL inhibitors. In summary, the live cell DAGLα assay reported here offers an economical and convenient format to screen for novel inhibitors as part of drug discovery programmes and compliments previously reported high-throughput membrane based DAGL assays. PMID:27013337

  16. Development of a biochemical switching device: mathematical model.

    Science.gov (United States)

    Okamoto, M

    1990-01-01

    There are many examples of enzymes that share substrates or cofactors in a cyclic manner. Techniques have been developed that use cyclic enzyme systems to assay quantitatively small amounts of biochemical substances (cofactor, substrate), however, only a few studies of the control of these systems have been published. The author previously showed with computer simulations that cyclic enzyme systems have the reliability of ON-OFF types of operation (McCulloch-Pitts' neuronic equation) and the applicability for a switching circuit in a biocomputer. The switching time was inevitably determined in accordance with the difference in amount between two inputs of the system. A unique switching mechanism of cyclic enzyme systems (basic switching element) and the effects of excitatory stimuli on switching properties of the integrated biochemical switching system are demonstrated. PMID:2082931

  17. Simultaneous Detection of Antigen-Specific IgG- and IgM-Secreting Cells with a B Cell Fluorospot Assay

    Directory of Open Access Journals (Sweden)

    M. Anthony Moody

    2012-03-01

    Full Text Available The traditional enzyme-linked immunospot (ELISpot assay is the gold standard for the enumeration of antigen-specific B cells. Since B cell availability from biological samples is often limited, either because of sample size/volume or the need of performing multiple analyses on the same sample, the implementation of ELISpot assay formats that allow the simultaneous detection of multiple antibody types is desirable. While dual-color ELISpot assays have been described, technical complexities have so far prevented their wide utilization as well as further expansion of their multicolor capability. An attractive solution is to replace the chromogenic reaction of the traditional ELISpot assay with a fluorescent detection system (fluorospot assay. Fluorospot assays using fluorophore-conjugated secondary antibodies in conjunction with fluorescence enhancers, FITC/anti-FITC and biotin/avidin amplification systems and dedicated equipment for spot detection have been developed to enumerate T-cells secreting two or three specific cytokines and, more recently, IgG and IgA antibody-secreting cells (ASCs. We hereby report a method for a multiplex B cell fluorospot assay that utilizes quantum-dot nanocrystals as reporters without further amplification systems or need of dedicated equipment. With this method we simultaneously enumerated HIV-1 gp41 envelope glycoprotein-specific IgG and IgM antibody-secreting cells with sensitivity comparable to that of the traditional ELISpot assay.

  18. Comparison of Fluorescence In Situ Hybridization and Chromogenic In Situ Hybridization for Low and High Throughput HER2 Genetic Testing

    DEFF Research Database (Denmark)

    Poulsen, Tim S; Espersen, Maiken Lise Marcker; Kofoed, Vibeke;

    2013-01-01

    results show that the differences between the HER2 genetic assays do not have an effect on the analytic performance and the CISH technology is superior to high throughput HER2 genetic testing due to scanning speed, while the IQ-FISH may still be a choice for fast low throughput HER2 genetic testing....... interest was identified from a serial H&E stained slide following tissue cores were transferred to a tissue microarrays (TMA). When using TMA in a routine flow, all patients will be tested for HER2 status with IHC followed by CISH or FISH, thereby providing individual HER2 results. In conclusion, our...

  19. Determination of HER2 amplification in primary breast cancer using dual-colour chromogenic in situ hybridization is comparable to fluorescence in situ hybridization: a European multicentre study involving 168 specimens

    OpenAIRE

    García-Caballero, Tomás; Grabau, Dorthe; Green, Andrew R.; Gregory, John; Schad, Arno; Kohlwes, Elke; Ellis, Ian O; Watts, Sarah; Mollerup, Jens

    2010-01-01

    García-Caballero T, Grabau D, Green A R, Gregory J, Schad A, Kohlwes E, Ellis I O, Watts S & Mollerup J (2010) Histopathology 56, 472–480 Determination of HER2 amplification in primary breast cancer using dual-colour chromogenic in situ hybridization is comparable to fluorescence in situ hybridization: a European multicentre study involving 168 specimens Aims: Fluorescence in situ hybridization (FISH) can be used to reveal several genomic imbalances relevant to proper cancer diagnosis and to ...

  20. Adapting Cell-Based Assays to the High Throughput Screening Platform: Problems Encountered and Lessons Learned

    OpenAIRE

    Maddox, Clinton B; Rasmussen, Lynn; White, E. Lucile

    2008-01-01

    In recent years, cell-based phenotypic assays have emerged as an effective and robust addition to the array of assay technologies available for drug discovery in the high throughput screening arena. Previously, biochemical target-based assays have been the technology of choice. With the emergence of stem cells as a basis for a new screening technology, it is important to keep in mind the lessons that have been learned from the adaptation of existing stable cell lines onto the high throughput ...

  1. Hyponatraemia: biochemical and clinical perspectives.

    OpenAIRE

    Gill, G; Leese, G

    1998-01-01

    Hyponatraemia is a common bio-chemical abnormality, occurring in about 15% of hospital inpatients. It is often associated with severe illness and relatively poor outcome. Pathophysiologically, hyponatraemia may be spurious, dilutional, depletional or redistributional. Particularly difficult causes and concepts of hyponatraemia are the syndrome of inappropriate antidiuresis and the sick cell syndrome, which are discussed here in detail. Therapy should always be targeted at the underlying disea...

  2. Application of orientation chromogenic medium on initial rapid identification of bacteria%定位显色培养基在细菌快速初步鉴定中的应用

    Institute of Scientific and Technical Information of China (English)

    杨自副; 陈默蕊

    2011-01-01

    Objective To evaluate the application of orientation chromogenic medium (OCM)on initial rapid identification of bacteria. Methods 3313 strains of bacteria isolated from clinical specimens and 145 strains of external quality assessment were inoculated on OCM,chromogenic character of different strains were observed and analyzed. Results There were certain chromogenic laws of different genera and species of bacteria on OCM. Conclusion OCM might have significant application value on initial rapid speculation and identification of bacteria.with the advantages of low-cost and high efficiency,and worth for widely clinical application.%目的 评价定位显色培养基在细菌快速初步鉴定中的作用.方法 将3 313株临床菌株和145株室间质评菌株点种于定位显色培养基上,观察显色特点,总结细菌显色规律.结果 不同种属的细菌在定位显色培养基上具有一定的显色规律.结论 定位显色培养基对细菌的快速初步推测和鉴定具有重要的应用价值,具有成本低廉、有助于提高工作效率等优势,值得推广应用.

  3. Simple, rapid spectrophotometry of urinary N-acetyl-beta-D-glucosaminidase, with use of a new chromogenic substrate.

    Science.gov (United States)

    Noto, A; Ogawa, Y; Mori, S; Yoshioka, M; Kitakaze, T; Hori, T; Nakamura, M; Miyake, T

    1983-10-01

    We have developed a new spectrophotometric assay for urinary N-acetyl-beta-D-glucosaminidase (NAGase) with use of sodio m-cresolsulfonphthaleinyl N-acetyl-beta-D-glucosaminide (MCP-NAG). MCP-NAG was synthesized from acetochloro-glucosamine and m-cresolsulfonphthalein (MCP) in four steps. MCP-NAG reacts well with NAGase (Km = 0.41 mmol/L) and is highly water soluble. The absorption maximum and molar absorptivity of the aglycone MCP are 580 nm and 40 670, respectively. Spectral overlap of interfering substances at 580 nm is almost negligible, so that the urine blank can be omitted from the assay procedure. The high molar absorptivity of MCP gives sufficient analytical sensitivity at a reaction time of 15 min. The correlation between the MCP-NAG method (y) and the fluorimetric method (x) involving 4-methylumbelliferyl N-acetyl-beta-D-glucosaminide is represented by the equation y = 0.995x - 0.669 (r = 0.991). Thus, the present method provides practical advantages over conventional methods, for use in the routine laboratory. PMID:6616814

  4. CPTAC Assay Portal: a repository of targeted proteomic assays

    Energy Technology Data Exchange (ETDEWEB)

    Whiteaker, Jeffrey R.; Halusa, Goran; Hoofnagle, Andrew N.; Sharma, Vagisha; MacLean, Brendan; Yan, Ping; Wrobel, John; Kennedy, Jacob; Mani, DR; Zimmerman, Lisa J.; Meyer, Matthew R.; Mesri, Mehdi; Rodriguez, Henry; Abbateillo, Susan E.; Boja, Emily; Carr, Steven A.; Chan, Daniel W.; Chen, Xian; Chen, Jing; Davies, Sherri; Ellis, Matthew; Fenyo, David; Hiltket, Tara; Ketchum, Karen; Kinsinger, Christopher; Kuhn, Eric; Liebler, Daniel; Lin, De; Liu, Tao; Loss, Michael; MacCoss, Michael; Qian, Weijun; Rivers, Robert; Rodland, Karin D.; Ruggles, Kelly; Scott, Mitchell; Smith, Richard D.; Thomas, Stefani N.; Townsend, Reid; Whiteley, Gordon; Wu, Chaochao; Zhang, Hui; Zhang, Zhen; Paulovich, Amanda G.

    2014-06-27

    To address these issues, the Clinical Proteomic Tumor Analysis Consortium (CPTAC) of the National Cancer Institute (NCI) has launched an Assay Portal (http://assays.cancer.gov) to serve as a public repository of well-characterized quantitative, MS-based, targeted proteomic assays. The purpose of the CPTAC Assay Portal is to facilitate widespread adoption of targeted MS assays by disseminating SOPs, reagents, and assay characterization data for highly characterized assays. A primary aim of the NCI-supported portal is to bring together clinicians or biologists and analytical chemists to answer hypothesis-driven questions using targeted, MS-based assays. Assay content is easily accessed through queries and filters, enabling investigators to find assays to proteins relevant to their areas of interest. Detailed characterization data are available for each assay, enabling researchers to evaluate assay performance prior to launching the assay in their own laboratory.

  5. Transgenic Animal Mutation Assays

    Institute of Scientific and Technical Information of China (English)

    Tao Chen; Ph.D.D.A.B.T.

    2005-01-01

    @@ The novel transgenic mouse and rat mutation assays have provided a tool for analyzing in vivo mutation in any tissue, thus permitting the direct comparison of cancer incidence with mutant frequency.

  6. The neutral comet assay

    International Nuclear Information System (INIS)

    The single-cell gel electrophoresis (or comet) assay is a rapid and sensitive fluorescence microscopic method that is used for the detection of DNA damage at the individual cell level. Comet assay under neutral conditions allows the detection of DNA double-strand breaks, considered to the biologically relevant radiation-induced lesion. In this report we describe modifications of the neutral comet method and its use for studying DNA damage and its repair in irradiated human lymphocytes. (author)

  7. Proto-oncogene HER-2 in normal, dysplastic and tumorous feline mammary glands: an immunohistochemical and chromogenic in situ hybridization study

    International Nuclear Information System (INIS)

    Feline mammary carcinoma has been proposed as a natural model of highly aggressive, hormone-independent human breast cancer. To further explore the utility of the model by adding new similarities between the two diseases, we have analyzed the oncogene HER-2 status at both the protein and the gene levels. Formalin-fixed, paraffin-embedded tissue samples from 30 invasive carcinomas, 7 benign lesions and two normal mammary glands were analyzed. Tumour features with prognostic value were recorded. The expression of protein HER-2 was analyzed by immunohistochemistry and the number of gene copies by means of DNA chromogenic in situ hybridization. Immunohistochemical HER-2 protein overexpression was found in 40% of feline mammary carcinomas, a percentage higher to that observed in human breast carcinoma. As in women, feline tumours with HER-2 protein overexpression had pathological features of high malignancy. However, amplification of HER-2 was detected in 16% of carcinomas with protein overexpression, a percentage much lower than that observed in their human counterpart. Feline mammary carcinoma would be a suitable natural model of that subset of human breast carcinomas with HER-2 protein overexpression without gene amplification

  8. Correlation and comparison of immunohistochemistry for HER2/neu, using the antibody SP3 and chromogenic in situ hybridization in breast carcinomas samples

    Directory of Open Access Journals (Sweden)

    Franciele F. Wolf

    2015-12-01

    Full Text Available ABSTRACT Introduction: Advances in the field of molecular biology have provided the differentiation of molecular subtypes of breast tumors, providing better prognosis and important tools for the treatment of patients with breast cancer. Among these subtypes, the changes in the human epidermal growth factor receptor 2 gene (HER2/neu, increase its copy number and generating HER2 protein amplification. Studies show that patients with breast cancer HER2/neu amplified tend to relapse earlier and have shorter survival time, the monoclonal antibody Trastuzumab is the therapy indicated. The eligibility of patients for therapy is initially made by the immunohistochemistry (IHC technique, which evaluates the expression level of the HER2 protein. After this evaluation, the cases with equivocal diagnosis (score 2+, are referred to a more accurate technique, the chromogenic in situ hybridization (CISH. Objective: To analyze the sensitivity and specificity of the antibody SP3, and determine their level of agreement with the CISH technique. Material and methods: Retrospective study in the database of the anatomy-pathology laboratory, in CISH tests reports for HER2/neu. Conclusion: The results revealed that clone SP3 showed 100% specificity and 92% sensitivity. IHC reveals variability in its results; however, it is known that the technique is an important tool in the daily routine of laboratories, contributing to the initial screening of patients with breast cancer, which later showed satisfactory results when compared with the CISH technique.

  9. Proto-oncogene HER-2 in normal, dysplastic and tumorous feline mammary glands: an immunohistochemical and chromogenic in situ hybridization study

    Directory of Open Access Journals (Sweden)

    Martín de las Mulas Juana

    2007-09-01

    Full Text Available Abstract Background Feline mammary carcinoma has been proposed as a natural model of highly aggressive, hormone-independent human breast cancer. To further explore the utility of the model by adding new similarities between the two diseases, we have analyzed the oncogene HER-2 status at both the protein and the gene levels. Methods Formalin-fixed, paraffin-embedded tissue samples from 30 invasive carcinomas, 7 benign lesions and two normal mammary glands were analyzed. Tumour features with prognostic value were recorded. The expression of protein HER-2 was analyzed by immunohistochemistry and the number of gene copies by means of DNA chromogenic in situ hybridization. Results Immunohistochemical HER-2 protein overexpression was found in 40% of feline mammary carcinomas, a percentage higher to that observed in human breast carcinoma. As in women, feline tumours with HER-2 protein overexpression had pathological features of high malignancy. However, amplification of HER-2 was detected in 16% of carcinomas with protein overexpression, a percentage much lower than that observed in their human counterpart. Conclusion Feline mammary carcinoma would be a suitable natural model of that subset of human breast carcinomas with HER-2 protein overexpression without gene amplification.

  10. Recidiva del color dentario por té, café y vino: In vitro Dental bleaching regression caused by chromogenic beverages: In vitro

    Directory of Open Access Journals (Sweden)

    M Arévalo Pineda

    2012-08-01

    Full Text Available Este estudio, in vitro, determinó si los dientes con clareamiento presentan mayor cambio de color en el tiempo que los no tratados, al someterse a tinción con bebidas cromógenas, café, té y vino. Se utilizaron 45 incisivos sanos de bovino conservados en suero a 37ºC. Cada espécimen se dividió en dos mitades, una sometida a clareamiento con peróxido de hidrógeno al 35% y otra control. Se midió color con Espectrofotómetro Vita EasyShade. Se dividieron los especímenes al azar en grupos de 15 y fueron sumergidos en café, té y vino, durante 10 minutos, 20 veces, registrando color después de cada inmersión. Los datos fueron analizados con ANOVA y Test de Tukey, con 95% de intervalo de confianza. Los resultados mostraron que, el clareamiento modifica significativamente (p=0.05 el color en los tres grupos (GC=85.8 a 95.1; GT=87.4 a 97.3 y GV=90.8 a 99.3, la recidiva de color se observa a lo largo de las 20 inmersiones, siendo significativa la diferencia de valores ΔE iniciales (GC=18.89; GT=22.97; GV=56.46 y finales (GC=5.56; GT=5.38; GV=12.49. El grupo tratado presenta mayor descenso de unidades ΔE a lo largo de las inmersiones, por lo que es el más teñido (GCcontrol=20.98-5.01; GTcontrol=17.11-3.66; GVcontrol=54.62-11.49. Las tres bebidas cromógenas causan recidiva de color en los dientes clareados, siendo el vino el que causa mayor tinción. Se concluyó que las piezas tratadas, sometidas a los tres tipos de cromógenos, tienen mayor cambio de color que las que no lo son, pero finalmente no se oscurecen más que las no tratadas.This in vitro study established if teeth treated with dental bleaching have a higher change of color over time than those that aren’t treated, when subjected to three chromogenic beverages (coffee, tea and red wine. 45 healthy bovine incisors were used, maintained in 0.9% sodium chloride, at 37ºC. Every specimen was divided into 2 half; one half was subjected to dental bleaching with 35% hydrogen

  11. Selective sensing of submicromolar iron(III) with 3,3‧,5,5‧-tetramethylbenzidine as a chromogenic probe

    Science.gov (United States)

    Zhang, Lufeng; Du, Jianxiu

    2016-04-01

    The development of highly selective and sensitive method for iron(III) detection is of great importance both from human health as well as environmental point of view. We herein reported a simple, selective and sensitive colorimetric method for the detection of Fe(III) at submicromolar level with 3,3,‧5,5‧-tetramethylbenzidine (TMB) as a chromogenic probe. It was observed that Fe(III) could directly oxidize TMB to form a blue solution without adding any extra oxidants. The reaction has a stoichiometric ratio of 1:1 (Fe(III)/TMB) as determined by a molar ratio method. The resultant color change can be perceived by the naked eye or monitored the absorbance change at 652 nm. The method allowed the measurement of Fe(III) in the range 1.0 × 10- 7-1.5 × 10- 4 mol L- 1 with a detection limit of 5.5 × 10- 8 mol L- 1. The relative standard deviation was 0.9% for eleven replicate measurements of 2.5 × 10- 5 mol L- 1 Fe(III) solution. The chemistry showed high selectivity for Fe(III) in contrast to other common cation ions. The practically of the method was evaluated by the determination of Fe in milk samples; good consistency was obtained between the results of this method and atomic absorption spectrophotometry as indicated by statistical analysis.

  12. Somatic cell count and milk neutrophil viability of dairy heifers with specific CXCR1 genotypes following experimental intramammary infection with Staphylococcus chromogenes originating from milk.

    Science.gov (United States)

    Verbeke, Joren; Piccart, Kristine; Piepers, Sofie; Van Poucke, Mario; Peelman, Luc; De Visscher, Anneleen; De Vliegher, Sarne

    2015-06-01

    Previous observational studies suggest an association between polymorphism c.980A>G in the CXCR1 gene, encoding the chemokine (C-X-C motif) receptor 1, and the innate immunity and infection status of the mammary gland. Mammary glands of eight Holstein heifers were experimentally infected with a Staphylococcus chromogenes isolate originating from a chronic intramammary infection (IMI) to study differences between CXCR1 genotypes c.980AG and c.980GG. Quarters from heifers with genotypes c.980AG and c.980GG developed subclinical mastitis but showed differences in the early response at 6-18 h post challenge. Bacterial count at 18 h post challenge tended to be higher in quarters from c.980AG heifers compared to c.980GG heifers. Somatic cell count (SCC) was higher at 6 h post challenge and tended to be higher at 9 h post challenge in c.980AG heifers compared to c.980GG heifers. Milk production decreased similarly. Milk neutrophils of c.980AG heifers showed more apoptosis at 9 h post challenge and tended to show more necrosis at 6, 9 and 12 h post challenge than c.980GG heifers. Differences were less pronounced in the later stage (>18 h) of infection. The results demonstrate that CXCR1 polymorphism can influence SCC and milk neutrophil viability following experimental IMI. PMID:25933826

  13. Assay method and compositions

    International Nuclear Information System (INIS)

    Methods are described for measuring catecholamine levels in human and animal body fluids and tissues using the catechol-O-methyl-transferase (COMT) radioassay. The assay involves incubating the biological sample with COMT and the tritiated methyl donor, S-adenosyl-L-methionine(3H)-methyl. The O-methylated (3H) epinephrine and/or norepinephrine are extracted and oxidised to vanillin-3H which in turn is extracted and its radioactivity counted. When analysing dopamine levels the assay is extended by vanillin-3H and raising the pH of the aqueous periodate phase from which O-methylated (3H) dopamine is extracted and counted. The assay may be modified depending on whether measurements of undifferentiated total endogenous catecholamine levels or differential analyses of the catecholamine levels are being performed. The sensitivity of the assay can be as low as 5 picograms for norepinephrine and epinephrine and 12 picograms for dopamine. The assemblance of the essential components of the assay into a kit for use in laboratories is also described. (U.K.)

  14. A UK NEQAS ISH multicenter ring study using the Ventana HER2 dual-color ISH assay.

    LENUS (Irish Health Repository)

    Bartlett, J M S

    2011-01-01

    We performed a multicenter assessment of a new HER2 dual-color chromogenic in situ hybridization (CISH) test and herein report on concordance of CISH data with fluorescence in situ hybridization (FISH) data and intraobserver and interlaboratory scoring consistency. HER2 results were evaluated using duplicate cores from 30 breast cancers in 5 laboratories using the Ventana HER2 dual-color ISH assay (Ventana Medical Systems, Cambridgeshire, England) and in 1 central laboratory using a standard FISH assay. Overall 93.3% of cases were successfully analyzed by CISH across the 5 participating laboratories. There was excellent concordance (98.0% overall) for diagnosis of HER2 amplification by CISH compared with FISH. Intraobserver variability (7.7%) and intersite variability (9.1%) of absolute HER2\\/chromosome enumeration probe 17 ratios were tightly controlled across all participating laboratories. The Ventana HER2 dual-color ISH assay is robust and reproducible, shows good concordance with a standard FISH assay, and complies with requirements in national and international guidelines for performance of ISH-based diagnostic tests.

  15. Biochemical Abnormalities in Batten's Syndrome

    DEFF Research Database (Denmark)

    Clausen, Jytte Lene; Nielsen, Gunnar Gissel; Jensen, Gunde Egeskov; Shukla, V.K.S.

    1978-01-01

    The present data indicate that a group of ten patients with Batten's syndrome showed reduced activity of erythrocyte glutathione (GSH) peroxidase (Px) (glutathione: H2O2 oxidoreductase, EC 1.1.1.9.) using H2O2 as peroxide donor. Assay of erythrocyte GSHPx using H2O2, cumene hydroperoxide and t-bu...

  16. Cell-free Assays for HIV-1 Uncoating

    OpenAIRE

    Aiken, Christopher

    2009-01-01

    Uncoating is an essential step in the retrovirus life cycle about which little is known. Uncoating is defined as the specific dissociation of the capsid shell from the viral core in the host cell cytoplasm. In this chapter, biochemical assays for studying HIV-1 uncoating in vitro are described. These techniques have proven useful for characterizing HIV-1 mutants that exhibit defects in the uncoating step of infection.

  17. Cell-free assays for HIV-1 uncoating.

    Science.gov (United States)

    Aiken, Christopher

    2009-01-01

    Uncoating is an essential step in the retrovirus life cycle about which little is known. Uncoating is defined as the specific dissociation of the capsid shell from the viral core in the host cell cytoplasm. In this chapter, biochemical assays for studying HIV-1 uncoating in vitro are described. These techniques have proven useful for characterizing HIV-1 mutants that exhibit defects in the uncoating step of infection. PMID:19020817

  18. Plasminogen activator and its assay of the activity

    International Nuclear Information System (INIS)

    Plasminogen activators (PA) are specific proteolytic enzymes. Which convert the inactive proenzyme to plasmin. The plasmin formed is a potent and nonspecific protease which cleaves blood fibrin clots into soluble polypeptide. The author describes some biochemical characteristic of the different components of the plasminogen activator system, current methods for assay of the activity of the PA. The potential application of PA as diagnostic tools in diseases of the thrombi

  19. Rover waste assay system

    Energy Technology Data Exchange (ETDEWEB)

    Akers, D.W.; Stoots, C.M.; Kraft, N.C.; Marts, D.J. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-11-01

    The Rover Waste Assay System (RWAS) is a nondestructive assay system designed for the rapid assay of highly-enriched {sup 235}U contaminated piping, tank sections, and debris from the Rover nuclear rocket fuel processing facility at the Idaho Chemical Processing Plant. A scanning system translates a NaI(Tl) detector/collimator system over the structural components where both relative and calibrated measurements for {sup 137}Cs are made. Uranium-235 concentrations are in operation and is sufficiently automated that most functions are performed by the computer system. These functions include system calibration, problem identification, collimator control, data analysis, and reporting. Calibration of the system was done through a combination of measurements on calibration standards and benchmarked modeling. A description of the system is presented along with the methods and uncertainties associated with the calibration and analysis of the system for components from the Rover facility. 4 refs., 2 figs., 4 tabs.

  20. Rover waste assay system

    International Nuclear Information System (INIS)

    The Rover Waste Assay System (RWAS) is a nondestructive assay system designed for the rapid assay of highly-enriched 235U contaminated piping, tank sections, and debris from the Rover nuclear rocket fuel processing facility at the Idaho Chemical Processing Plant. A scanning system translates a NaI(Tl) detector/collimator system over the structural components where both relative and calibrated measurements for 137Cs are made. Uranium-235 concentrations are in operation and is sufficiently automated that most functions are performed by the computer system. These functions include system calibration, problem identification, collimator control, data analysis, and reporting. Calibration of the system was done through a combination of measurements on calibration standards and benchmarked modeling. A description of the system is presented along with the methods and uncertainties associated with the calibration and analysis of the system for components from the Rover facility. 4 refs., 2 figs., 4 tabs

  1. Neutral Comet Assay

    OpenAIRE

    2013-01-01

    The Comet assay (or Single Cell Gel Electrophoresis assay) is a sensitive technique to detect DNA damage at the level of an individual cell. This technique is based on micro-electrophoresis of cells DNA content. Briefly, cells are embedded in agarose, lysed and submitted to an electric field, before the staining step with a fluorescent DNA binding dye. Damaged DNA (charged DNA) migrates in this field, forming the tail of a “comet”, while undamaged DNA remained in the head of the “comet”. The ...

  2. Lateral flow strip assay

    Science.gov (United States)

    Miles, Robin R.; Benett, William J.; Coleman, Matthew A.; Pearson, Francesca S.; Nasarabadi, Shanavaz L.

    2011-03-08

    A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

  3. Automated phantom assay system

    International Nuclear Information System (INIS)

    This paper describes an automated phantom assay system developed for assaying phantoms spiked with minute quantities of radionuclides. The system includes a computer-controlled linear-translation table that positions the phantom at exact distances from a spectrometer. A multichannel analyzer (MCA) interfaces with a computer to collect gamma spectral data. Signals transmitted between the controller and MCA synchronize data collection and phantom positioning. Measured data are then stored on disk for subsequent analysis. The automated system allows continuous unattended operation and ensures reproducible results

  4. Alternative Methods for the Detection of Emerging Marine Toxins: Biosensors, Biochemical Assays and Cell-Based Assays

    OpenAIRE

    Laia Reverté; Lucía Soliño; Olga Carnicer; Jorge Diogène; Mònica Campàs

    2014-01-01

    The emergence of marine toxins in water and seafood may have a considerable impact on public health. Although the tendency in Europe is to consolidate, when possible, official reference methods based on instrumental analysis, the development of alternative or complementary methods providing functional or toxicological information may provide advantages in terms of risk identification, but also low cost, simplicity, ease of use and high-throughput analysis. This article gives an overview of th...

  5. Biochemical Characterization of a Protease Involved in the Processing of a Streptomyces reticuli Cellulase (Avicelase).

    Science.gov (United States)

    Moormann, M; Schlochtermeier, A; Schrempf, H

    1993-05-01

    A 36-kDa protease from Streptomyces reticuli had recently been shown to be responsible for the in vivo and in vitro processing of the 82-kDa cellulase (Avicelase) Cel-1 from S. reticuli to a 42-kDa truncated enzyme. It was induced only in the presence of Avicel, hydroxyethylcellulose, and xylan. The addition of the nonionic detergent Tween 80 to the culture medium containing Avicel as the carbon source led to a 10-fold increase in extracellular proteolytic activity. The protease, which has an isoelectric point of 3.9, was purified to homogeneity from the culture filtrate by a combination of anion-exchange and hydrophobic-interaction chromatographies and was characterized biochemically. The enzyme hydrolyzed gelatin and the chromogenic substrates Azocoll, Azocasein, and Azoalbumin. Its highest activity was determined between pH 7.0 and 7.7 and at 55 degrees C. The proteolytic activity was inhibited by 1,10-phenanthroline and EDTA; however, no metal ions were detected to be associated with the protein. The protease was stable in the presence of 1 M urea and 0.01 M sodium dodecyl sulfate. The inhibitory effect of alpha-2-macroglobulin indicated an endo-mode of proteolytic cleavage. Studies with lectins and sugar analysis by mass spectroscopy indicated that the cellulase (Avicelase) Cel-1 was neither N nor O glycosylated. Its processing by the protease occurred at temperatures ranging from 30 to 55 degrees C, pH 7.5, in the presence of 2 mM dithiothreitol. PMID:16348937

  6. Hyaluronic Acid Assays

    DEFF Research Database (Denmark)

    Itenov, Theis S; Kirkby, Nikolai S; Bestle, Morten H;

    2015-01-01

    BACKGROUD: Hyaluronic acid (HA) is proposed as a marker of functional liver capacity. The aim of the present study was to compare a new turbidimetric assay for measuring HA with the current standard method. METHODS: HA was measured by a particle-enhanced turbidimetric immunoassay (PETIA) and enzyme...

  7. Instrument for assaying radiation

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Jody Rustyn; Farfan, Eduardo B.

    2016-03-22

    An instrument for assaying radiation includes a flat panel detector having a first side opposed to a second side. A collimated aperture covers at least a portion of the first side of the flat panel detector. At least one of a display screen or a radiation shield may cover at least a portion of the second side of the flat panel detector.

  8. Biochemical Analysis of Microbial Rhodopsins.

    Science.gov (United States)

    Maresca, Julia A; Keffer, Jessica L; Miller, Kelsey J

    2016-01-01

    Ion-pumping rhodopsins transfer ions across the microbial cell membrane in a light-dependent fashion. As the rate of biochemical characterization of microbial rhodopsins begins to catch up to the rate of microbial rhodopsin identification in environmental and genomic sequence data sets, in vitro analysis of their light-absorbing properties and in vivo analysis of ion pumping will remain critical to characterizing these proteins. As we learn more about the variety of physiological roles performed by microbial rhodopsins in different cell types and environments, observing the localization patterns of the rhodopsins and/or quantifying the number of rhodopsin-bearing cells in natural environments will become more important. Here, we provide protocols for purification of rhodopsin-containing membranes, detection of ion pumping, and observation of functional rhodopsins in laboratory and environmental samples using total internal reflection fluorescence microscopy. © 2016 by John Wiley & Sons, Inc. PMID:27153387

  9. An integrated microfluidic biochemical detection system for protein analysis with magnetic bead-based sampling capabilities.

    Science.gov (United States)

    Choi, Jin-Woo; Oh, Kwang W; Thomas, Jennifer H; Heineman, William R; Halsall, H Brian; Nevin, Joseph H; Helmicki, Arthur J; Henderson, H Thurman; Ahn, Chong H

    2002-02-01

    This paper presents the development and characterization of an integrated microfluidic biochemical detection system for fast and low-volume immunoassays using magnetic beads, which are used as both immobilization surfaces and bio-molecule carriers. Microfluidic components have been developed and integrated to construct a microfluidic biochemical detection system. Magnetic bead-based immunoassay, as a typical example of biochemical detection and analysis, has been successfully performed on the integrated microfluidic biochemical analysis system that includes a surface-mounted biofilter and electrochemical sensor on a glass microfluidic motherboard. Total time required for an immunoassay was less than 20 min including sample incubation time, and sample volume wasted was less than 50 microl during five repeated assays. Fast and low-volume biochemical analysis has been successfully achieved with the developed biofilter and immunosensor, which is integrated to the microfluidic system. Such a magnetic bead-based biochemical detection system, described in this paper, can be applied to protein analysis systems. PMID:15100857

  10. Serum Biochemical Phenotypes in the Domestic Dog

    Science.gov (United States)

    Chang, Yu-Mei; Hadox, Erin; Szladovits, Balazs; Garden, Oliver A.

    2016-01-01

    The serum or plasma biochemical profile is essential in the diagnosis and monitoring of systemic disease in veterinary medicine, but current reference intervals typically take no account of breed-specific differences. Breed-specific hematological phenotypes have been documented in the domestic dog, but little has been published on serum biochemical phenotypes in this species. Serum biochemical profiles of dogs in which all measurements fell within the existing reference intervals were retrieved from a large veterinary database. Serum biochemical profiles from 3045 dogs were retrieved, of which 1495 had an accompanying normal glucose concentration. Sixty pure breeds plus a mixed breed control group were represented by at least 10 individuals. All analytes, except for sodium, chloride and glucose, showed variation with age. Total protein, globulin, potassium, chloride, creatinine, cholesterol, total bilirubin, ALT, CK, amylase, and lipase varied between sexes. Neutering status significantly impacted all analytes except albumin, sodium, calcium, urea, and glucose. Principal component analysis of serum biochemical data revealed 36 pure breeds with distinctive phenotypes. Furthermore, comparative analysis identified 23 breeds with significant differences from the mixed breed group in all biochemical analytes except urea and glucose. Eighteen breeds were identified by both principal component and comparative analysis. Tentative reference intervals were generated for breeds with a distinctive phenotype identified by comparative analysis and represented by at least 120 individuals. This is the first large-scale analysis of breed-specific serum biochemical phenotypes in the domestic dog and highlights potential genetic components of biochemical traits in this species. PMID:26919479

  11. Biochemical bases of mineral waters genesis

    Directory of Open Access Journals (Sweden)

    D. D. Zhernosekov

    2005-02-01

    Full Text Available This work directs data about mineral water genesis. The accent on balneological sense is done. We suggest the criteria of biochemical processes estimation which take part in mineral water compounds creation. These criteria can be used for illustration of dependence between waters medical properties and biochemical processes of their genesis.

  12. Dual isotope assays

    International Nuclear Information System (INIS)

    Dual isotope assays for thyroid function are performed by carrying out a radio-immunoassay for two of thyroxine (T4), tri-iodothyronine (T3), thyroid stimulating hormone (TSH), and thyroxine binding globulin (TBG), by a method wherein a version of one of the thyroid components, preferably T4 or T3 is labelled with Selenium-75 and the version of the other thyroid component is labelled with a different radionuclide, preferably Iodine-125. (author)

  13. Automated uranium assays

    International Nuclear Information System (INIS)

    Precise, timely inventories of enriched uranium stocks are vital to help prevent the loss, theft, or diversion of this material for illicit use. A wet-chemistry analyzer has been developed at LLL to assist in these inventories by performing automated analyses of uranium samples from different stages in the nuclear fuel cycle. These assays offer improved accuracy, reduced costs, significant savings in manpower, and lower radiation exposure for personnel compared with present techniques

  14. Disagreement between Human Papillomavirus Assays

    DEFF Research Database (Denmark)

    Rebolj, Matejka; Preisler, Sarah; Ejegod, Ditte Møller;

    2014-01-01

    We aimed to determine the disagreement in primary cervical screening between four human papillomavirus assays: Hybrid Capture 2, cobas, CLART, and APTIMA. Material from 5,064 SurePath samples of women participating in routine cervical screening in Copenhagen, Denmark, was tested with the four...... assays. Positive agreement between the assays was measured as the conditional probability that the results of all compared assays were positive given that at least one assay returned a positive result. Of all 5,064 samples, 1,679 (33.2%) tested positive on at least one of the assays. Among these, 41......-65 years (n = 2,881), 23% tested positive on at least one assay, and 42 to 58% of these showed positive agreement on any compared pair of the assays. While 4% of primary screening samples showed abnormal cytology, 6 to 10% were discordant on any pair of assays. A literature review corroborated our findings...

  15. The clinical significance of biochemical indexes for nutritional assessment in neonates

    International Nuclear Information System (INIS)

    Objective: To investigate the biochemical indexes for nutritional assessment in the newborns. Methods: Serum insulin-like growth factor-1 (IGF-1) levels in neonates were measured with RIA, retinol-binding protein (RBP) and prealbumin (PA) were measured with enzyme-liked immunosorbent assay (ELISA). The tested groups consisted of 65 SGAs and AGAs (according to birth weight) with nutritionally normals and abnormals approximately equally numbered. Results: The serum levels of IGF-1, RBP and PA in the 32 malnutritional SGAs were significantly lower than those in the 35 nutritionally normal SGAs. The serum levels of the above-mentioned three in the 33 malnutritional AGAs were also significantly lower than those in the 35 nutritionally normal AGAs. Conclusion: IGF-1, RBP and PA could be used as biochemical indexes for nutritional assessment and would not be affected by the gestational age and birth weight. Biochemical measurements cannot be substituted by anthropometric measurements for the diagnosis of neonatal malnutrition

  16. Histological and Biochemical Evaluation of the Kidney following Chronic Consumption of Hibiscus sabdariffa

    Directory of Open Access Journals (Sweden)

    U. U. Ukoha

    2015-01-01

    Full Text Available Hibiscus sabdariffa L. has been used traditionally as herbal medicine and has been documented to have a broad range of therapeutic effects. The present study aimed to investigate the effects of chronic administration of aqueous extract of flowers of Hibiscus sabdariffa on the histology of the kidney and some biochemical indices of renal function in male Wistar rats. Twenty (20 Wistar rats were randomly divided into four (4 groups of five rats each. The extract was administered orally in doses 200, 500, and 800 mg/kg body weight for 21 days. The kidney was harvested and processed histologically and blood samples were taken for biochemical assays. The histological results showed dose dependent pathological states and the biochemical analysis revealed a dose dependant variation in renal indices. These results suggest that chronic administration of aqueous extract of Hibiscus sabdariffa may be toxic to the kidney.

  17. A High Throughput MHC II Binding Assay for Quantitative Analysis of Peptide Epitopes

    OpenAIRE

    Salvat, Regina; Moise, Leonard; Bailey-Kellogg, Chris; Griswold, Karl E

    2014-01-01

    Biochemical assays with recombinant human MHC II molecules can provide rapid, quantitative insights into immunogenic epitope identification, deletion, or design1,2. Here, a peptide-MHC II binding assay is scaled to 384-well format. The scaled down protocol reduces reagent costs by 75% and is higher throughput than previously described 96-well protocols1,3-5. Specifically, the experimental design permits robust and reproducible analysis of up to 15 peptides against one MHC II allele per 384-we...

  18. Radiorespirometic assay device

    International Nuclear Information System (INIS)

    A radiorespirometic assay device is described in which the presence of microorganisms in a sample is determined by placing the sample in contact with a metabolisable radioactive labelled substrate, collecting any gas evolved, exposing a photosensitive material to the gas and determining if a spot is produced on the material. A spot indicates the presence of radioactivity showing that the substrate has been metabolized by a microorganism. Bacteria may be detected in body fluids, hospital operating rooms, water, food, cosmetics and drugs. (U.K.)

  19. Radon assay for SNO+

    International Nuclear Information System (INIS)

    The SNO+ experiment will study neutrinos while located 6,800 feet below the surface of the earth at SNOLAB. Though shielded from surface backgrounds, emanation of radon radioisotopes from the surrounding rock leads to back-grounds. The characteristic decay of radon and its daughters allows for an alpha detection technique to count the amount of Rn-222 atoms collected. Traps can collect Rn-222 from various positions and materials, including an assay skid that will collect Rn-222 from the organic liquid scintillator used to detect interactions within SNO+

  20. Radon assay for SNO+

    Energy Technology Data Exchange (ETDEWEB)

    Rumleskie, Janet [Laurentian University, Greater Sudbury, Ontario (Canada)

    2015-12-31

    The SNO+ experiment will study neutrinos while located 6,800 feet below the surface of the earth at SNOLAB. Though shielded from surface backgrounds, emanation of radon radioisotopes from the surrounding rock leads to back-grounds. The characteristic decay of radon and its daughters allows for an alpha detection technique to count the amount of Rn-222 atoms collected. Traps can collect Rn-222 from various positions and materials, including an assay skid that will collect Rn-222 from the organic liquid scintillator used to detect interactions within SNO+.

  1. HER2/neu Expression and Gene Alterations in Pancreatic Ductal Adenocarcinoma: A Comparative mmunohistochemistry and Chromogenic in Situ Hybridization Study Based on Tissue Microarrays and Computerized Image Analysis

    Directory of Open Access Journals (Sweden)

    Evangelos Tsiambas

    2006-05-01

    Full Text Available Context: HER2/neu overexpression is observed in many cancers including pancreatic ductal adenocarcinoma. Although immunohistochemistry remains the basic method for evaluating HER2/neu protein expression, significant information regarding gene status cannot be assessed. Design: Using tissue microarray technology, fifty histologically confirmed pancreatic ductal adenocarcinomas were cored twice and re-embedded in one paraffin block. Immunohistochemistry (clone TAB 250 and chromogenic (HER2/neu amplification Spot Light kit in situ hybridization protocols were performed. The immunostained slides were evaluated by conventional eye microscopy and digital image analysis. The chi square test and the kappa statistic were applied by running the SPSS package. Main outcome measures :The levels of staining intensity were estimated by the performance of a semi automated image analysis system. Results :HER2/neu gene amplification was detected in 8/50 cases (16%. Chromosome 17 aneuploidy was detected in 19 cases (38%. Significant improvement in interobserver agreement (kappa=0.76 vs. 0.94 was achieved correlating the immunohistochemical results obtained by conventional eye and digital microscopy, especially in the cases of overexpression (2+, 3+. Finally, 29 (58%, 11 (22%, 6 (12% and 4 (8% cases were characterized as 0, 1+, 2+ and 3+, respectively. HER2/neu protein expression was significantly associated with grade (P=0.019, but not with stage (P=0.466. in addition, chromosome 17 and gene status were not correlated with stage and grade.. Conclusion :Our results indicate that a subset of pancreatic ductal adenocarcinomas is characterized by HER2/neu gene amplification. In contrast to breast cancer, protein overexpression does not predict this specific gene deregulation mechanism. This event may reflect the different biological role of the molecule in those two solid tumours, affecting the response to novel targeted agents, such as monoclonal anti-HER2/neu

  2. Activity profiles of 309 ToxCastTM chemicals evaluated across 292 biochemical targets

    International Nuclear Information System (INIS)

    Understanding the potential health risks posed by environmental chemicals is a significant challenge elevated by the large number of diverse chemicals with generally uncharacterized exposures, mechanisms, and toxicities. The present study is a performance evaluation and critical analysis of assay results for an array of 292 high-throughput cell-free assays aimed at preliminary toxicity evaluation of 320 environmental chemicals in EPA's ToxCastTM project (Phase I). The chemicals (309 unique, 11 replicates) were mainly precursors or the active agent of commercial pesticides, for which a wealth of in vivo toxicity data is available. Biochemical HTS (high-throughput screening) profiled cell and tissue extracts using semi-automated biochemical and pharmacological methodologies to evaluate a subset of G-protein coupled receptors (GPCRs), CYP450 enzymes (CYPs), kinases, phosphatases, proteases, HDACs, nuclear receptors, ion channels, and transporters. The primary screen tested all chemicals at a relatively high concentration 25 μM concentration (or 10 μM for CYP assays), and a secondary screen re-tested 9132 chemical-assay pairs in 8-point concentration series from 0.023 to 50 μM (or 0.009-20 μM for CYPs). Mapping relationships across 93,440 chemical-assay pairs based on half-maximal activity concentration (AC50) revealed both known and novel targets in signaling and metabolic pathways. The primary dataset, summary data and details on quality control checks are available for download at (http://www.epa.gov/ncct/toxcast/).

  3. 闭管消解-萘乙二胺分光光度法测定水中总氮%Determination of Total Nitrogen in Water by Closed Digestion N - (1 -Naphthyl)ethyle Chromogenic Reaction

    Institute of Scientific and Technical Information of China (English)

    赵洋甬; 赵建平; 黄绍荣; 肖国起

    2012-01-01

    This paper established a new method of determining total nitrogen in water through closed digestion N - ( 1 - Naphthyl) ethyle chromogenic reaction, and analyzed the effect of different conditions to resaults at the same time based on experiment . The results show that water samples should be digested at least 25 minutes, and then chromogenically reacted for 5 ~ 20 minutes between 10~25℃ and finally determined at 535nm. This new method is more sensitive compared with the standard method,and it can be uesd to analysis the total nitrogen in water or wastewater.%通过实验研究了一种采用闭管消解-萘乙二胺分光光度法测定水样中总氮的新方法,分析了不同测试条件对测定结果的影响.结果表明:方法最佳消解时间为25min,宜选用535nm为实验波长,在10~25℃下显色5~ 20min完成测定.与标准方法比较,该方法具有灵敏度高、测定时间短的优点,可用于环境监测中水和废水的总氮分析.

  4. BIOCHEMICAL SCREENING OF DIABETIC NEPHROPATHY

    Directory of Open Access Journals (Sweden)

    Vivek

    2016-01-01

    Full Text Available Diabetic nephropathy is a clinical syndrome characterized by the following- Persistent albuminuria (>300mg/d or >200μg/min, that is confirmed on at least 2 occasions 3-6 months apart diabetic, progressive decline in the Glomerular Filtration Rate (GFR, elevated arterial blood pressure. The earliest biochemical criteria for the diagnosis of diabetic nephropathy is the presence of micro-albumin in the urine, which if left untreated will eventually lead to End-Stage Renal Disease (ESRD. Micro-albuminuria refers to the excretion of albumin in the urine at a rate that exceeds normal limits. The current study was conducted to establish the prevalence of micro-albuminuria in a sequential sample of diabetic patients attending hospital and OPD Clinic to determine its relationship with known and putative risk factors to identify micro- and normo-albuminuric patients in their sample for subsequent comparison in different age, sex, weight and creatinine clearance of the micro- and normo-albuminuric patients. This cross-sectional analytical study was conducted in one hundred patients at Saraswathi Institute of Medical Sciences, Anwarpur, Hapur, U. P. Patients having diabetes mellitus in different age group ranging from 30 to 70 years were selected. Data was analysed by SPSS software. Micro-albuminuria was observed in 35% in patients with type 2 diabetes mellitus. It was observed that 65% patients were free from any type of albuminuria. Also micro-albuminuria was present in 10% of the patients less than 50 yrs. of age, while 15% of the patients more than 50 yrs. of age were having micro-albuminuria. There was a statistically significant correlation of micro-albuminuria with duration of diabetes. Incidence of micro-albuminuria increases with age as well as increased duration of diabetes mellitus. Our study shows that only 5% patients developed macro-albuminuria. Glycosylated haemoglobin and fasting plasma glucose was significantly raised among all these

  5. Biochemical characterization of a detergent-stable serine alkaline protease from Caldicoprobacter guelmensis

    OpenAIRE

    Bouacem, K.; Bouanane-Darenfed, A.; Laribi-Habchi, H.; Ben Elhoul, M.; Hmida-Sayari, A.; Hacene, H.; Ollivier, Bernard; Fardeau, Marie-Laure; Jaouadi, B.; Bejar, S.

    2015-01-01

    Caldicoprobacter guelmensis isolated from the hydrothermal hot spring of Guelma (Algeria) produced high amounts of extracellular thermostable serine alkaline protease (called SAPCG) (23,000 U/mL). The latter was purified by ammonium sulphate precipitation, UNO Q-6 FPLC and Zorbex PSM 300 HPLC, and submitted to biochemical characterization assays. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis revealed that the purified enzyme was a monomer...

  6. Antimicrobial Susceptibility Pattern, Biochemical Characteristics and Biotyping of Salmonella paratyphi A: An Impact of Biofield Treatment

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Enteric fever is a major global problem. Emergence of antimicrobial resistance threatens to render current treatments ineffective. The current study was attempted to investigate the effect of biofield treatment on Salmonella paratyphi A (S. paratyphi A) in terms of antimicrobial susceptibility assay, biochemical characteristics and biotyping. S. paratyphi A strain were procured from MicroBioLogics in sealed packs bearing the American Type Culture Collection (ATCC 9150). The study was conducte...

  7. Tissue Residues, Hematological and Biochemical Effects of Tilmicosin in Broiler Chicken

    OpenAIRE

    Mossad Elsayed; Ashraf Elkomy; Mohamed Aboubakr; Mohamed Morad

    2014-01-01

    The aim of this study was to determine the blood and tissue concentrations profile and effect of tilmicosin on some hematological and biochemical parameters in broiler chicken. Fifty clinically healthy Hubbard chickens were orally administered 25 mg/kg BW of tilmicosin once daily for 5 consecutive days. Tissue residues of tilmicosin in slaughtered healthy chicken could not be detected by microbiological assay in all tested tissues except in lung (at 96 hours) and liver and kidneys (at 72 hour...

  8. Evaluating biochemical methane production from brewer's spent yeast.

    Science.gov (United States)

    Sosa-Hernández, Ornella; Parameswaran, Prathap; Alemán-Nava, Gibrán Sidney; Torres, César I; Parra-Saldívar, Roberto

    2016-09-01

    Anaerobic digestion treatment of brewer's spent yeast (SY) is a viable option for bioenergy capture. The biochemical methane potential (BMP) assay was performed with three different samples (SY1, SY2, and SY3) and SY1 dilutions (75, 50, and 25 % on a v/v basis). Gompertz-equation parameters denoted slow degradability of SY1 with methane production rates of 14.59-4.63 mL/day and lag phases of 10.72-19.7 days. Performance and kinetic parameters were obtained with the Gompertz equation and the first-order hydrolysis model with SY2 and SY3 diluted 25 % and SY1 50 %. A SY2 25 % gave a 17 % of TCOD conversion to methane as well as shorter lag phase (methane production. Methane capture and biogas composition were dependent upon the SY source, and co-digestion (or dilution) can be advantageous. PMID:27276935

  9. Canberra waste assay systems

    International Nuclear Information System (INIS)

    Canberra Industries, Inc. (USA) offers complete solutions and turnkey systems for qualifying and quantifying drums of radioactive waste. Different Waste Assay Systems are available for low-, medium-, and high activity barrels. Such systems scan the segments of the drums. The gamma-emitting nuclides present in the radioactive waste are identified from the spectra of the gamma-rays emitted and their activities are quantified. The spectrum of each segment of the waste container is analysed separately and the results are summed for total drum inventory reporting. The Waste Assay specific Canberra software is an easy-to-use menu driven program. It offers automatic procedures for routine work but interactive mode is also available to investigate particular cases. The way of analysis and the format and contents of the report can be customized. Additional Quality Control program module monitors system parameters. The measured and calculated values of each waste container are saved into a relational database. Canberra offers mathematical efficiency calibration services for different drum types, with different waste densities and different activities. This new theoretical approach of efficiency calibration eliminates the need of calibration drums, thus saving costs. For field applications Canberra developed a portable In-Situ Object Counting System. This system determines efficiency calibration for any kind of objects after the user enters its size and density, furthermore the type of shielding and the distance between the detector and the object. (author)

  10. Biochemical genetics of some Indian fishes

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.; Qasim, S.Z.

    Studies on biochemical genetics of fishes, using electrophoretic methods, are relatively of recent origin. Earlier serum and eye lens protein were used to identify marine populations. This technique showed that closely related species have...

  11. Physics and Electro-Biochemical Technology

    Directory of Open Access Journals (Sweden)

    Conrad P Pritscher

    2008-12-01

    Full Text Available Not Available Keywords: Biochemical technology, physics Received: 22 October 2008 / Received in revised form: 23 October 2008, Accepted: 24 October 2008 Published online: 07 January 2009

  12. Detection of Germination inhibitors in fruits of Terminalia laxiflora Engl. and Diels using biochemical assays

    Directory of Open Access Journals (Sweden)

    Mai M. A. Hassan

    2013-06-01

    Full Text Available Terminalia laxiflora is multipurpose tree in Sudan. But it has low germination percentage, which may affect its natural regeneration. There were evidence that the fruits have an inhibitory effect, so this study was carried out to determine which part of the fruit that affect germination and seedlings growth. Three parts of the fruit extraction were examine (Coat, Pulp and Wing with tow concentration to each part (200 fruit/litre, 100 fruit/litre.the results showed that all extractions had no effect on germination percentage except fruit coat extract (200 fruit/litre, which reduced it significantly. The different extractions had no effect on root length and seem to elongate the shoot expect fruit pulp (200 fruit/litre, which no different from control. All extractions had no effect on first leave appearance, but they causing abnormal seedlings. The result suggest new treatments that could be applied on the fruit of this species like de winging or de pulping the fruit before sewing or soaking in acid or hot water after de winging, de pulping and de coating. These results can be of great value for the medicinal plant scientists and users to try T. laxiflora fruit extractions for controlling bacteria and fungi activities and it may be an addition benefit to the medicinal uses of this tree.

  13. Micromachined filter-chamber array with passive valves for biochemical assays on beads

    NARCIS (Netherlands)

    Lichtenberg, Jan; Verpoorte, Elisabeth; De Rooij, Nico F.

    2001-01-01

    The filter-chamber array presented here enables a real-time parallel analysis of three different samples on beads in a volume of 3 nL, on a 1 cm2chip. The filter-chamber array is a system containing three filter-chambers, three passive valves at the inlet channels and a common outlet. The design ena

  14. Nuclear pore complex assembly studied with a biochemical assay for annulate lamellae formation

    OpenAIRE

    1995-01-01

    Formation of the nuclear pore is an intricate process involving membrane fusion and the ordered assembly of up to 1,000 pore proteins. As such, the study of pore assembly is not a simple one. Interestingly, annulate lamellae, a cytoplasmic organelle consisting of stacks of flattened membrane cisternae perforated by numerous pore complexes, have been found to form spontaneously in a reconstitution system derived from Xenopus egg extracts, as determined by electron microscopy (Dabauvalle et al....

  15. PREDICTIVE ASSAY FOR RODENT CARCINOGENICITY USING IN VIVO BIOCHEMICAL PARAMETERS: OPERATIONAL CHARACTERISTICS AND COMPLEMENTARITY

    Science.gov (United States)

    Linear models of risk assessment may be appropriate for chemicals that are initiators of carcinogenesis while threshold models of risk assessment have been proposed for promoters. he proper risk assessment model for the regulation of promoters of carcinogenesis remains an active ...

  16. Free energy simulations of important biochemical processes

    OpenAIRE

    Yang LIU; 刘洋

    2013-01-01

    Free energy simulations have been widely employed to compute the thermodynamic properties of many important biochemical processes. In the first part of this dissertation, two important biochemical processes, protonation/deprotonation of acid in solution and solvation of small organic molecules, are investigated using free energy simulations. Accurate computation of the pKa value of a compound in solution is important and challenging. To efficiently simulate the free energy change associat...

  17. FLUIDICS DEVICE FOR ASSAY

    DEFF Research Database (Denmark)

    2007-01-01

    The present invention relates to a device for use in performing assays on standard laboratory solid supports whereon chemical entities are attached. The invention furthermore relates to the use of such a device and a kit comprising such a device. The device according to the present invention is...... adapted to receive one or more replaceable solid support(s) (40) onto which chemical entities (41) are attached, said device comprising a base (1, 60, 80, 300, 400, 10, 70, 140, 20, 90, 120, 150, 30, 100), one or more inlet(s) (5), one or more outlet(s) (6). The base and the solid support (40) defines......, when operatively connected, one or more chambers (21) comprising the chemical entities (41), the inlet(s) (5) and outlet(s) (6) and chambers (21) being in fluid connection. The device further comprise means for providing differing chemical conditions in each chamber (21)....

  18. Assay of oestrogen

    International Nuclear Information System (INIS)

    A particular problem with the direct radioimmunoassay of unconjugated oestriol in pregnancy is caused by the increased amount of steroid-binding proteins present in pregnancy serum and plasma. The steroid-binding proteins react with oestriol and 125I-labelled oestriol during the assay procedure and the steroid-protein bound 125I-labelled oestriol is precipitated along with the antibody-bound 125I-labelled oestriol by the ammonium sulphate solution separation system. A novel method is described whereby progesterone (1-20 μg/ml) is used to block the action of steroid-binding proteins in pregnancy serum and plasma samples, thus minimizing interference in a direct radioimmunoassay for unconjugated oestriol using a specific anti-oestriol serum. (U.K.)

  19. RMBNToolbox: random models for biochemical networks

    Directory of Open Access Journals (Sweden)

    Niemi Jari

    2007-05-01

    Full Text Available Abstract Background There is an increasing interest to model biochemical and cell biological networks, as well as to the computational analysis of these models. The development of analysis methodologies and related software is rapid in the field. However, the number of available models is still relatively small and the model sizes remain limited. The lack of kinetic information is usually the limiting factor for the construction of detailed simulation models. Results We present a computational toolbox for generating random biochemical network models which mimic real biochemical networks. The toolbox is called Random Models for Biochemical Networks. The toolbox works in the Matlab environment, and it makes it possible to generate various network structures, stoichiometries, kinetic laws for reactions, and parameters therein. The generation can be based on statistical rules and distributions, and more detailed information of real biochemical networks can be used in situations where it is known. The toolbox can be easily extended. The resulting network models can be exported in the format of Systems Biology Markup Language. Conclusion While more information is accumulating on biochemical networks, random networks can be used as an intermediate step towards their better understanding. Random networks make it possible to study the effects of various network characteristics to the overall behavior of the network. Moreover, the construction of artificial network models provides the ground truth data needed in the validation of various computational methods in the fields of parameter estimation and data analysis.

  20. Comparative biochemical analysis of recombinant reverse transcriptase enzymes of HIV-1 subtype B and subtype C

    Directory of Open Access Journals (Sweden)

    Moisi Daniella

    2010-10-01

    Full Text Available Abstract Background HIV-1 subtype C infections account for over half of global HIV infections, yet the vast focus of HIV-1 research has been on subtype B viruses which represent less than 12% of the global pandemic. Since HIV-1 reverse transcriptase (RT is a major target of antiviral therapy, and since differential drug resistance pathways have been observed among different HIV subtypes, it is important to study and compare the enzymatic activities of HIV-1 RT derived from each of subtypes B and C as well as to determine the susceptibilities of these enzymes to various RT inhibitors in biochemical assays. Methods Recombinant subtype B and C HIV-1 RTs in heterodimeric form were purified from Escherichia coli and enzyme activities were compared in cell-free assays. The efficiency of (- ssDNA synthesis was measured using gel-based assays with HIV-1 PBS RNA template and tRNA3Lys as primer. Processivity was assayed under single-cycle conditions using both homopolymeric and heteropolymeric RNA templates. Intrinsic RNase H activity was compared using 5'-end labeled RNA template annealed to 3'-end recessed DNA primer in a time course study in the presence and absence of a heparin trap. A mis-incorporation assay was used to assess the fidelity of the two RT enzymes. Drug susceptibility assays were performed both in cell-free assays using recombinant enzymes and in cell culture phenotyping assays. Results The comparative biochemical analyses of recombinant subtype B and subtype C HIV-1 reverse transcriptase indicate that the two enzymes are very similar biochemically in efficiency of tRNA-primed (- ssDNA synthesis, processivity, fidelity and RNase H activity, and that both enzymes show similar susceptibilities to commonly used NRTIs and NNRTIs. Cell culture phenotyping assays confirmed these results. Conclusions Overall enzyme activity and drug susceptibility of HIV-1 subtype C RT are comparable to those of subtype B RT. The use of RT inhibitors (RTIs

  1. PathogenMip Assay: A Multiplex Pathogen Detection Assay

    OpenAIRE

    Akhras, Michael S.; Sreedevi Thiyagarajan; Villablanca, Andrea C.; Davis, Ronald W; Pål Nyrén; Nader Pourmand

    2007-01-01

    The Molecular Inversion Probe (MIP) assay has been previously applied to a large-scale human SNP detection. Here we describe the PathogenMip Assay, a complete protocol for probe production and applied approaches to pathogen detection. We have demonstrated the utility of this assay with an initial set of 24 probes targeting the most clinically relevant HPV genotypes associated with cervical cancer progression. Probe construction was based on a novel, cost-effective, ligase-based protocol. The ...

  2. Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

    International Nuclear Information System (INIS)

    Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H2O2/1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

  3. Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Sabanero, M.; Flores V, L. L. [Universidad de Guanajuato, Departamento de Biologia, DCNE, Noria Alta s/n, 36250 Guanajuato, Gto. (Mexico); Azorin V, J. C.; Vallejo, M. A.; Cordova F, T.; Sosa A, M. [Universidad de Guanajuato, Departamento de Ingenieria Fisica, DCI, Loma del Bosque 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Castruita D, J. P. [Universidad de Guadalajara, Departamento de Ecologia, CUCBA, Las Agujas, 45100 Zapopan, Jalisco (Mexico); Barbosa S, G., E-mail: myrna.sabanero@gmail.com [Universidad de Guanajuato, Departamento de Ciencias Medicas, DCS, 20 de Enero No. 929, Col. Obregon, 37000 Leon, Guanajuato (Mexico)

    2015-10-15

    Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H{sub 2}O{sub 2}/1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

  4. Mammalian cells exposed to ionizing radiation: Structural and biochemical aspects.

    Science.gov (United States)

    Sabanero, Myrna; Azorín-Vega, Juan Carlos; Flores-Villavicencio, Lérida Liss; Castruita-Dominguez, J Pedro; Vallejo, Miguel Angel; Barbosa-Sabanero, Gloria; Cordova-Fraga, Teodoro; Sosa-Aquino, Modesto

    2016-02-01

    Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv/year) and subsequently exposure to high doses produces greater effects in people. It has been reported that people who have been exposed to low doses of radiation (less than 50 mSv/year) and subsequently are exposed to high doses, have greater effects. However, at a molecular and biochemical level, it is an unknown alteration. This study, analyzes the susceptibility of a biological system (HeLa ATCC CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/90 s). Our research considers multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin microfilaments), nuclei (DAPI), and genomic DNA. The results indicate, that cells exposed to ionizing radiation show structural alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin microfilaments. Similar alterations were observed in cells treated with a genotoxic agent (200 μM H2O2/1h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between various line cells. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. PMID:26656429

  5. Metal-linked Immunosorbent Assay (MeLISA): the Enzyme-Free Alternative to ELISA for Biomarker Detection in Serum.

    Science.gov (United States)

    Yu, Ru-Jia; Ma, Wei; Liu, Xiao-Yuan; Jin, Hong-Ying; Han, Huan-Xing; Wang, Hong-Yang; Tian, He; Long, Yi-Tao

    2016-01-01

    Determination of disease biomarkers in clinical samples is of crucial significance for disease monitoring and public health. The dominating format is enzyme-linked immunosorbent assay (ELISA), which subtly exploits both the antigen-antibody reaction and biocatalytic property of enzymes. Although enzymes play an important role in this platform, they generally suffer from inferior stability and less tolerant of temperature, pH condition compared with general chemical product. Here, we demonstrate a metal-linked immunosorbent assay (MeLISA) based on a robust signal amplification mechanism that faithfully replaces the essential element of the enzyme. As an enzyme-free alternative to ELISA, this methodology works by the detection of α-fetoprotein (AFP), prostatic specific antigen (PSA) and C-reactive protein (CRP) at concentrations of 0.1 ng mL(-1), 0.1 ng mL(-1) and 1 ng mL(-1) respectively. It exhibits approximately two magnitudes higher sensitivity and is 4 times faster for chromogenic reaction than ELISA. The detection of AFP and PSA was further confirmed by over a hundred serum samples from hepatocellular carcinoma (HCC) and prostate cancer patients respectively. PMID:27446504

  6. Synthesis and adsorption properties of Pb2+ chromogenic imprinted adsorbent%铅离子显色印迹吸附剂的制备及其吸附性能

    Institute of Scientific and Technical Information of China (English)

    程文霞; 刘成伦; 谢太平

    2013-01-01

    以pb2+为模版分子,在硅胶表面接枝双硫腙,利用溶胶-凝胶法合成一种pb2+显色印迹吸附剂(MIPs).采用红外(IR)和扫描电镜(SEM)对MIPs进行了表征.通过平衡吸附实验,研究了MIPs的吸附性能、显色性能和其对pb2+的选择识别性能.结果表明,双硫腙通过与硅胶形成氢键而接枝在硅胶表面;MIPs对pb2+的显色限为10μmol/L;在Cd2+存在的条件下,其对pb2+的相对选择系数为250;MIPs对pb2+的吸附可以用Langmiur等温吸附方程来拟合,吸附焓变为66.054kJ/mol.制备的MIPs在5min内吸附率可以达到97%,可以用于含铅废水中pb2+的分离和测定.%A new type of Pb2+ chromogenic imprinted adsorbent was prepared by sol-gel approach with Pb2+ as the template and dithizone grafting onto the silica gel surface. The adsorbent was characterized by FT-IR and scanning electron microscopy. The adsorption property, chromogenic property and selective recognition ability of the adsorbent were studied by equilibrium-adsorption method. Results showed that the dithizone was coated on the silica gel through hydrogen bond. The chromogenic limit of the printed adsorbent was 10μmol/L,the relative selectivity coefficient was 250 while Cd2+ existed; the extraction behavior of the Pb2+ was conformed by Langmuir's equation and the enthalpy of adsorption was 66. 054kJ/mol. The adsorption capacity reached 97% in 5 min and it could be used for separation and determination of trace Pb2+ in the waste water.

  7. 40 CFR 158.2010 - Biochemical pesticides data requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Biochemical pesticides data...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical Pesticides § 158.2010 Biochemical pesticides... required to support registration of biochemical pesticides. Sections 158.2080 through 158.2084 identify...

  8. 40 CFR 158.2000 - Biochemical pesticides definition and applicability.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Biochemical pesticides definition and...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical Pesticides § 158.2000 Biochemical pesticides definition and applicability. This subpart applies to all biochemical pesticides as defined in paragraphs...

  9. Data quality in drug discovery: the role of analytical performance in ligand binding assays.

    Science.gov (United States)

    Wätzig, Hermann; Oltmann-Norden, Imke; Steinicke, Franziska; Alhazmi, Hassan A; Nachbar, Markus; El-Hady, Deia Abd; Albishri, Hassan M; Baumann, Knut; Exner, Thomas; Böckler, Frank M; El Deeb, Sami

    2015-09-01

    Despite its importance and all the considerable efforts made, the progress in drug discovery is limited. One main reason for this is the partly questionable data quality. Models relating biological activity and structures and in silico predictions rely on precisely and accurately measured binding data. However, these data vary so strongly, such that only variations by orders of magnitude are considered as unreliable. This can certainly be improved considering the high analytical performance in pharmaceutical quality control. Thus the principles, properties and performances of biochemical and cell-based assays are revisited and evaluated. In the part of biochemical assays immunoassays, fluorescence assays, surface plasmon resonance, isothermal calorimetry, nuclear magnetic resonance and affinity capillary electrophoresis are discussed in details, in addition radiation-based ligand binding assays, mass spectrometry, atomic force microscopy and microscale thermophoresis are briefly evaluated. In addition, general sources of error, such as solvent, dilution, sample pretreatment and the quality of reagents and reference materials are discussed. Biochemical assays can be optimized to provide good accuracy and precision (e.g. percental relative standard deviation <10 %). Cell-based assays are often considered superior related to the biological significance, however, typically they cannot still be considered as really quantitative, in particular when results are compared over longer periods of time or between laboratories. A very careful choice of assays is therefore recommended. Strategies to further optimize assays are outlined, considering the evaluation and the decrease of the relevant error sources. Analytical performance and data quality are still advancing and will further advance the progress in drug development. PMID:26070362

  10. Biochemical properties of the bromodeoxyuridine-induced guinea pig virus.

    Science.gov (United States)

    Michalides, R; Schlom, J; Dahlberg, J; Perk, K

    1975-10-01

    The biophysical and biochemical properties of the virus particles released by guinea pig embryo cells treated with 5-bromo-2'-deoxyuridine (BUdR) have been compared to those of the B-type mouse mammary tumor virus (MMTV) and the C-type Rauscher murine leukemia virus. The high-molecular-weight (60 to 70S) RNA of the BUdR-induced guinea pig virus (GPV) has a molecular weight of 8 X 106 when measred by mixed agarose polyacylamide gel electrophoresis. The virus particles isolated from the tissue culture medium of BUdR-induced guniea pig cells have the following properties in common with MMTV: (i) a buoyant density of 1.18 g/ml in sucrose and 1.21 g/ml in CsCl, and (ii) a DNA polymerase that prefers Mg2+ over Mn2+ in an assay using the synthetic template poly(rC):oligo(dG). No nucleic acid sequence homology between GPV RNA and the viral RNAs of the MMTV, murine leukemia virus, hamster sarcoma virus, or Mason-Pfizer monkey virus could be observed in a competition hybridization assay using the radioactive-labeled GPV 60 to 70S RNA. By this same competition by hybridization assay the frequency of GPV proviral sequences was estimated to be at least 83 per haploid cellular genome of guniea pig cells. No nucleic acid sequences related to be GPV RNA were detected in the DNA of normal tissues of mice, rats, cats, dogs, baboons, or humans by direct RNA-DNA hybridization using radioactive GPV60 to 70S RNA. PMID:51933

  11. Reconfigurable neuromorphic computation in biochemical systems.

    Science.gov (United States)

    Chiang, Hui-Ju Katherine; Jiang, Jie-Hong R; Fages, Francois

    2015-08-01

    Implementing application-specific computation and control tasks within a biochemical system has been an important pursuit in synthetic biology. Most synthetic designs to date have focused on realizing systems of fixed functions using specifically engineered components, thus lacking flexibility to adapt to uncertain and dynamically-changing environments. To remedy this limitation, an analog and modularized approach to realize reconfigurable neuromorphic computation with biochemical reactions is presented. We propose a biochemical neural network consisting of neuronal modules and interconnects that are both reconfigurable through external or internal control over the concentrations of certain molecular species. Case studies on classification and machine learning applications using the DNA strain displacement technology demonstrate the effectiveness of our design in both reconfiguration and autonomous adaptation. PMID:26736417

  12. A competitive and reversible deactivation approach to catalysis-based quantitative assays.

    Science.gov (United States)

    Koide, Kazunori; Tracey, Matthew P; Bu, Xiaodong; Jo, Junyong; Williams, Michael J; Welch, Christopher J

    2016-01-01

    Catalysis-based signal amplification makes optical assays highly sensitive and widely useful in chemical and biochemical research. However, assays must be fine-tuned to avoid signal saturation, substrate depletion and nonlinear performance. Furthermore, once stopped, such assays cannot be restarted, limiting the dynamic range to two orders of magnitude with respect to analyte concentrations. In addition, abundant analytes are difficult to quantify under catalytic conditions due to rapid signal saturation. Herein, we report an approach in which a catalytic reaction competes with a concomitant inactivation of the catalyst or consumption of a reagent required for signal generation. As such, signal generation proceeds for a limited time, then autonomously and reversibly stalls. In two catalysis-based assays, we demonstrate restarting autonomously stalled reactions, enabling accurate measurement over five orders of magnitude, including analyte levels above substrate concentration. This indicates that the dynamic range of catalysis-based assays can be significantly broadened through competitive and reversible deactivation. PMID:26891765

  13. 6-sulfatoxymelatonin collected from infant diapers: feasibility and implications for urinary biochemical markers.

    Science.gov (United States)

    Thomas, Karen A

    2010-01-01

    The purpose of this study was to assess feasibility and acceptability of using a diaper pad for collection of in-home infant urinary samples and to test the accuracy of diaper pad extraction for 6-sulfatoxymelatonin and creatinine, which was used to correct assay results for urinary volume. To assess feasibility and acceptability, urine samples from 20 infants were collected over a 24-hr day using a cotton pad inserted in the diaper. The accuracy of diaper pad extraction was evaluated in the laboratory using urine samples collected from 11 adult volunteers and assayed using enzyme immunosorbent assay (EIA). Urine samples were divided, one aliquot was assayed without extraction, and one aliquot was instilled into a diaper pad, extracted, and assayed. Mothers found diaper pad collection acceptable and easy to perform. Of 144 infant urinary samples obtained in the home environment, 59% were usable for assay purposes, and the remaining either were contaminated with stool or were of insufficient volume. While creatinine values from diaper pad extracted and nonextracted samples were highly correlated (r(2) = .947), those of creatinine-corrected 6-sulfatoxymelatonin were not (r(2) = .216). Diaper pad collection procedures altered 6-sulfatoxymelatonin values. Implications for measurement of urinary biochemical substances and statistical analysis are discussed. PMID:19502239

  14. A protein-protein binding assay using coated microtitre plates: increased throughput, reproducibility and speed compared to bead-based assays.

    Science.gov (United States)

    Craig, Tim J; Ciufo, Leonora F; Morgan, Alan

    2004-07-30

    Protein-protein interactions, and the factors affecting them, are of fundamental importance to all biological systems. Surface plasmon resonance (SPR) and isothermal titration calorimetry (ITR) are powerful methods for assaying such interactions, but are expensive to implement. In contrast, bead-based pull-down assays using affinity tags such as glutathione-S-transferase (GST), require no specialist equipment. As a result, such assays are the most popular method for analysing protein-protein interactions, despite being time-consuming and prone to variability. In respect of these problems, we have modified this form of binding assay, using glutathione-coated 96-well plates rather than glutathione-Sepharose beads to bind the primary bait protein. Quantitation of bound protein utilises ELISA for purified proteins and scintillation counting for in vitro translated proteins, rather than the SDS-PAGE-based detection methods used in traditional bead-based assays. These modifications result in an approximately 10-fold increase in the number of samples that can be assayed daily, and allow results to be obtained within hours as opposed to days. We validate the modified assay by analysing the equilibrium binding of Munc18 and syntaxin, and also demonstrate that association and dissociation kinetics may be measured using this approach. The method we describe is generally applicable to any protein-protein interaction assay based on affinity tags and is amenable to automation, and so should benefit a wide range of biochemical research. PMID:15236910

  15. From Antenna to Assay

    Science.gov (United States)

    Moore, Evan G.; Samuel, Amanda P. S.; Raymond, Kenneth N.

    2009-01-01

    Conspectus Ligand-sensitized, luminescent lanthanide(III) complexes are of considerable importance because their unique photophysical properties (microsecond to millisecond lifetimes, characteristic and narrow emission bands, and large Stokes shifts) make them well suited as labels in fluorescence-based bioassays. The long-lived emission of lanthanide(III) cations can be temporally resolved from scattered light and background fluorescence to vastly enhance measurement sensitivity. One challenge in this field is the design of sensitizing ligands that provide highly emissive complexes with sufficient stability and aqueous solubility for practical applications. In this Account, we give an overview of some of the general properties of the trivalent lanthanides and follow with a summary of advances made in our laboratory in the development of highly luminescent Tb(III) and Eu(III) complexes for applications in biotechnology. A focus of our research has been the optimization of these compounds as potential commercial agents for use in Homogeneous Time-Resolved Fluorescence (HTRF) technology. Our approach involves developing high-stability octadentate Tb(III) and Eu(III) complexes that rely on all-oxygen donor atoms and using multi-chromophore chelates to increase molar absorptivity; earlier examples utilized a single pendant chromophore (that is, a single “antenna”). Ligands based on 2-hydroxyisophthalamide (IAM) provide exceptionally emissive Tb(III) complexes with quantum yield values up to ∼60% that are stable at the nanomolar concentrations required for commercial assays. Through synthetic modification of the IAM chromophore and time-dependent density functional theory (TD-DFT) calculations, we have developed a method to predict absorption and emission properties of these chromophores as a tool to guide ligand design. Additionally, we have investigated chiral IAM ligands that yield Tb(III) complexes possessing both high quantum yield values and strong

  16. Biochemical Applications in the Analytical Chemistry Lab

    Science.gov (United States)

    Strong, Cynthia; Ruttencutter, Jeffrey

    2004-01-01

    An HPLC and a UV-visible spectrophotometer are identified as instruments that helps to incorporate more biologically-relevant experiments into the course, in order to increase the students understanding of selected biochemistry topics and enhances their ability to apply an analytical approach to biochemical problems. The experiment teaches…

  17. Survey of Biochemical Education in Japanese Universities.

    Science.gov (United States)

    Kagawa, Yasuo

    1995-01-01

    Reports findings of questionnaires sent to faculty in charge of biochemical education in medical schools and other programs from dentistry to agriculture. Total class hours have declined since 1984. New trends include bioethics and computer-assisted learning. Tables show trends in lecture hours, lecture content, laboratory hours, core subject…

  18. 2009 Biochemical Conversion Platform Review Report

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, John [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2009-12-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the U.S. Department of Energy Biomass Program’s Biochemical Conversion platform review meeting, held on April 14-16, 2009, at the Sheraton Denver Downtown, Denver, Colorado.

  19. Biochemical Thermodynamics under near Physiological Conditions

    Science.gov (United States)

    Mendez, Eduardo

    2008-01-01

    The recommendations for nomenclature and tables in Biochemical Thermodynamics approved by IUBMB and IUPAC in 1994 can be easily introduced after the chemical thermodynamic formalism. Substitution of the usual standard thermodynamic properties by the transformed ones in the thermodynamic equations, and the use of appropriate thermodynamic tables…

  20. New Application of the Comet Assay: Chromosome–Comet Assay

    OpenAIRE

    Cortés-Gutiérrez, Elva I.; DÁVILA-RODRÍGUEZ, MARTHA I.; Fernández, José Luís; López-Fernández, Carmen; Gosálbez, Altea; Gosálvez, Jaime

    2011-01-01

    The comet assay is a well-established, simple, versatile, visual, rapid, and sensitive tool used extensively to assess DNA damage and DNA repair quantitatively and qualitatively in single cells. The comet assay is most frequently used to analyze white blood cells or lymphocytes in human biomonitoring studies, although other cell types have been examined, including buccal, nasal, epithelial, and placental cells and even spermatozoa. This study was conducted to design a protocol that can be use...

  1. Calorimetric assay of minor actinides

    Energy Technology Data Exchange (ETDEWEB)

    Rudy, C.; Bracken, D.; Cremers, T.; Foster, L.A.; Ensslin, N.

    1996-12-31

    This paper reviews the principles of calorimetric assay and evaluates its potential application to the minor actinides (U-232-4, Am-241, Am- 243, Cm-245, Np-237). We conclude that calorimetry and high- resolution gamma-ray isotopic analysis can be used for the assay of minor actinides by adapting existing methodologies for Pu/Am-241 mixtures. In some cases, mixtures of special nuclear materials and minor actinides may require the development of new methodologies that involve a combination of destructive and nondestructive assay techniques.

  2. Calorimetric assay of minor actinides

    International Nuclear Information System (INIS)

    This paper reviews the principles of calorimetric assay and evaluates its potential application to the minor actinides (U-232-4, Am-241, Am- 243, Cm-245, Np-237). We conclude that calorimetry and high- resolution gamma-ray isotopic analysis can be used for the assay of minor actinides by adapting existing methodologies for Pu/Am-241 mixtures. In some cases, mixtures of special nuclear materials and minor actinides may require the development of new methodologies that involve a combination of destructive and nondestructive assay techniques

  3. Biochemical mechanisms of insecticide resistance in field population of Dengue vector Aedes aegypti (Diptera: Culicidae.

    Directory of Open Access Journals (Sweden)

    R. Muthusamy

    2014-03-01

    Full Text Available Insecticide resistance has been known to be prevalent in several insect species including mosquito. It has become a major problem in vector control programme due to pesticide resistance through detoxification enzymes. The present study investigated the toxicity of Ae. aegypti to organophosphates and pyrethroid insecticide and biochemical mechanisms involved in insecticide resistance in larval population. Larval bioassay revealed an LC50 value of 0.734 ppm for dichlorvos and 1.140 ppm for λ-cyhalothrin exposure. Biochemical assay revealed increased activity of AChE (0.3 µmole/mg protein and GST in dichlorvos (1-1.5 µmole/mg protein treatment and esterase activity in λ-cyhalothrin treated compared to control activity. These studies suggest that AChE and GST is associated with organophosphate and esterase associated with pyrethroid resistance in Ae. aegypti.

  4. Biochemical switching device: biomimetic approach and application to neural network study.

    Science.gov (United States)

    Okamoto, M

    1992-06-01

    There are many examples of enzymes that share substrates or cofactors in a cyclic manner. Techniques have been developed that use cyclic enzyme systems to assay quantitatively small amounts of biochemical substances (cofactor, substrate), however, only a few studies of the control of these systems have been published. The author previously showed with computer simulations that cyclic enzyme systems have the reliability of ON-OFF types of operation (McCulloch-Pitts' neuronic equation) capable of storing short-memory, and the applicability for a switching circuit in a biocomputer. This paper introduces a unique switching mechanism of cyclic enzyme system (basic switching element), and next, building the integrated biochemical switching system being composed of the basic switching element, shows the physiological phenomenon termed 'selective elimination of synapses' generally produced as a result of low-frequency train of electrical stimuli to the synapses (Kuroda, Y. 1989) Neurochem. Int. 14, 309-319). PMID:1368350

  5. Clinical significance of biochemical markers of bone metabolism in patients with type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Objective: To investigate the clinical significance of changes of levels of biochemical markers of bone metabolism in patients with type 2 diabetes mellitus. Methods: Serum osteocalcin (BGP, with RIA), Ca alkaline phosphatase (ALP) and random specimen urinary deoxypyridinoline (DPD, with chemiluminescence assay), Ca, creatinine levels were measured in 40 patients with type 2 diabetes mellitus and 31 controls. Results: Serum BGP levels in diabetic patients were much lower than those in the controls (P<0.05); while urinary DPD/Cr ratio and Ca/Cr ratio were significantly higher in the patients than those in the controls (P<0.05, P<0.05). Serum Ca and ALP levels were about the same in the two groups. Conclusion: Loss of bone mass in diabetic patients are due to both decreased bone formation and increased bone resorption. Determination of the levels of the biochemical markers of bone metabolism (BGP, DPD......) could be applied for early detection of osteoporosis. (authors)

  6. Kombucha tea fermentation: Microbial and biochemical dynamics.

    Science.gov (United States)

    Chakravorty, Somnath; Bhattacharya, Semantee; Chatzinotas, Antonis; Chakraborty, Writachit; Bhattacharya, Debanjana; Gachhui, Ratan

    2016-03-01

    Kombucha tea, a non-alcoholic beverage, is acquiring significant interest due to its claimed beneficial properties. The microbial community of Kombucha tea consists of bacteria and yeast which thrive in two mutually non-exclusive compartments: the soup or the beverage and the biofilm floating on it. The microbial community and the biochemical properties of the beverage have so far mostly been described in separate studies. This, however, may prevent understanding the causal links between the microbial communities and the beneficial properties of Kombucha tea. Moreover, an extensive study into the microbial and biochemical dynamics has also been missing. In this study, we thus explored the structure and dynamics of the microbial community along with the biochemical properties of Kombucha tea at different time points up to 21 days of fermentation. We hypothesized that several biochemical properties will change during the course of fermentation along with the shifts in the yeast and bacterial communities. The yeast community of the biofilm did not show much variation over time and was dominated by Candida sp. (73.5-83%). The soup however, showed a significant shift in dominance from Candida sp. to Lachancea sp. on the 7th day of fermentation. This is the first report showing Candida as the most dominating yeast genus during Kombucha fermentation. Komagateibacter was identified as the single largest bacterial genus present in both the biofilm and the soup (~50%). The bacterial diversity was higher in the soup than in the biofilm with a peak on the seventh day of fermentation. The biochemical properties changed with the progression of the fermentation, i.e., beneficial properties of the beverage such as the radical scavenging ability increased significantly with a maximum increase at day 7. We further observed a significantly higher D-saccharic acid-1,4-lactone content and caffeine degradation property compared to previously described Kombucha tea fermentations. Our

  7. Dynamic analysis of biochemical network using complex network method

    OpenAIRE

    Wang Shuqiang; Shen Yanyan; Hu Jinxing; Li Ning; Zeng Dewei

    2015-01-01

    In this study, the stochastic biochemical reaction model is proposed based on the law of mass action and complex network theory. The dynamics of biochemical reaction system is presented as a set of non-linear differential equations and analyzed at the molecular-scale. Given the initial state and the evolution rules of the biochemical reaction system, the system can achieve homeostasis. Compared with random graph, the biochemical reaction network has larger ...

  8. Correlation between the genotoxicity endpoints measured by two different genotoxicity assays: comet assay and CBMN assay

    Directory of Open Access Journals (Sweden)

    Carina Ladeira

    2015-06-01

    The results concerning of positive findings by micronuclei and non significant ones by comet assay, are corroborated by Deng et al. (2005 study performed in workers occupationally exposed to methotrexate, also a cytostatic drug. According to Cavallo et al. (2009, the comet assay seems to be more suitable for the prompt evaluation of the genotoxic effects, for instance, of polycyclic aromatic hydrocarbons mixtures containing volatile substances, whereas the micronucleus test seems more appropriate to evaluate the effects of exposure to antineoplastic agents. However, there are studies that observed an increase in both the comet assay and the micronucleus test in nurses handling antineoplastic drugs, although statistical significance was only seen in the comet assay, quite the opposite of our results (Maluf & Erdtmann, 2000; Laffon et al. 2005.

  9. Biochemical considerations in the design of radiopharmaceuticals

    International Nuclear Information System (INIS)

    The goal of radiopharmaceutical chemistry is to design and develop radiotracers targeted to an organ or function whose activity kinetics in tissue can be detected externally by a gamma or a positron device. Radiopharmaceuticals are divided into the general categories of specific and non-specific agents. The specific radiopharmaceuticals are the tracers that follow a biochemical pathway or are involved in a particular interaction, for example metabolic substrates, drugs or analogs, and antibodies. This paper will focus on trends in the design of specific agents. The best radionuclides for the development of specific tracers are the positron emitting nuclides: carbon-11, nitrogen-13, oxygen-15 and fluorine-18. First the design of radiopharmaceuticals are considered in general (labeling strategies, stereochemical effects, specific activity). Next, a brief summary of the use of several radiopharmaceuticals is presented on the basis of their biochemical rationale. (orig./G.J.P.)

  10. Cytologic-Biochemical Radiation Dosimeters in Man

    International Nuclear Information System (INIS)

    The result of radiation interacting with living tissue is the deposition of energy therein. This energy triggers numerous chemical reactions within the molecules of the target tissues. We have measured in man the results of some of these reactions at doses up to 300 rads: chromosome aberrations; alterations in the kinetics of specific human cell populations; changes in 37 biochemical constituents of serum and/or urine. The utilization of chromosomes as a biological dosimeter is partially perfected but there are numerous discrepancies in data between different laboratories. Etiocholanolone can be used to evaluate marrow injury before the white-cell count falls below 5000/mm3. Most biochemical dosimeters evaluated gave negative or inconsistent results. However, salivary amylase is a promising indicator of human radiation injury from doses as low as 100 rads. (author)

  11. Reconstructing biochemical pathways from time course data.

    Science.gov (United States)

    Srividhya, Jeyaraman; Crampin, Edmund J; McSharry, Patrick E; Schnell, Santiago

    2007-03-01

    Time series data on biochemical reactions reveal transient behavior, away from chemical equilibrium, and contain information on the dynamic interactions among reacting components. However, this information can be difficult to extract using conventional analysis techniques. We present a new method to infer biochemical pathway mechanisms from time course data using a global nonlinear modeling technique to identify the elementary reaction steps which constitute the pathway. The method involves the generation of a complete dictionary of polynomial basis functions based on the law of mass action. Using these basis functions, there are two approaches to model construction, namely the general to specific and the specific to general approach. We demonstrate that our new methodology reconstructs the chemical reaction steps and connectivity of the glycolytic pathway of Lactococcus lactis from time course experimental data. PMID:17370261

  12. Optical Biochemical Platforms for Nanoparticles Detection

    CERN Document Server

    Campanella, Clarissa Martina

    2014-01-01

    In the biochemical sensing field, a fervent research activity related to the development of real time, low cost, compact and high throughput devices for the detection and characterization of natural or synthetic nanoparticles NPs actually exists. In this research scenario, different platforms for biosensing purposes have been developed according to the huge amount of physical effects involved in the transduction of the biochemical-signal into a measurable output signal. In the present work two different optical platforms for NP detection have been investigated, one based on integrated optics and the other based on microscopy. Both the approaches rely on the study of the interaction of an electromagnetic wave with a small particle in the hypothesis of dealing with a Rayleigh scatterer, i.e. a nanoparticle having a size really smaller than the one of the wavelength of the incident light and scattering light elastically.

  13. Biological dosimetry: biochemical and cellular parameters

    International Nuclear Information System (INIS)

    Early after the beginning of radiobiology studies, biochemistry has led to research of a biological dosimeter. From an extensive literature review, methods were selected that might be suitable for dose assessment via biochemical indicators. By now, research both in laboratory animals and in therapeutic or accidental human exposures, do not allow to retain a biochemical parameter alone for the purpose of diagnosis or prognosis. Several enzymatic activities have been precociously studied after irradiation: from these studies, it seems that analysis of four enzymatic activities in serum (serum glutamic oxaloacetic transaminase, amylase, lactic dehydrogenase, alkaline phosphatase) could be the most useful dosimetry system for mass sorting. Detection of DNA damage or methods for measuring somatic mutations are currently advancing and provide important new opportunities for biological dosimetry of low doses

  14. Biochemical changes in ginger after gamma irradiation

    International Nuclear Information System (INIS)

    Ginger (Zingiber officinate) was irradiated with gamma rays (0.1Kgy, 1.0Kgy). Biochemical changes during storage at room temperature (23-28 degree centigrade), in sand (23-28 degree centigrade) and at cold (8 degree centigrade) temperature were observed. Changes in starch, soluble protein, fixed oil and volatile oil contents showed that treatment of ginger at 0.1Kgy radiation level was most appropriate for storage upto 45 days

  15. Prions: the danger of biochemical weapons

    OpenAIRE

    Eric Almeida Xavier

    2014-01-01

    The knowledge of biotechnology increases the risk of using biochemical weapons for mass destruction. Prions are unprecedented infectious pathogens that cause a group of fatal neurodegenerative diseases by a novel mechanism. They are transmissible particles that are devoid of nucleic acid. Due to their singular characteristics, Prions emerge as potential danger since they can be used in the development of such weapons. Prions cause fatal infectious diseases, and to date there is no therapeutic...

  16. The stochastic dynamics of biochemical systems

    OpenAIRE

    Challenger, Joseph Daniel

    2013-01-01

    The topic of this thesis is the stochastic dynamics of biochemical reaction systems. The importance of the intrinsic fluctuations in these systems has become more widely appreciated in recent years, and should be accounted for when modelling such systems mathematically. These models are described as continuous time Markov processes and their dynamics defined by a master equation. Analytical progress is made possible by the use of the van Kampen system-size expansion, which splits the dynamics...

  17. The Biochemical Anatomy of Cortical Inhibitory Synapses

    OpenAIRE

    Heller, E.A.; Zhang, W.; Selimi, F.; Earnheart, J.C.; Slimak, M.A.; Santos-Torres, J.; Ibanez-Tallon, I.; Aoki, C; Chait, B. T.; Heintz, N

    2012-01-01

    Classical electron microscopic studies of the mammalian brain revealed two major classes of synapses, distinguished by the presence of a large postsynaptic density (PSD) exclusively at type 1, excitatory synapses. Biochemical studies of the PSD have established the paradigm of the synapse as a complex signal-processing machine that controls synaptic plasticity. We report here the results of a proteomic analysis of type 2, inhibitory synaptic complexes isolated by affinity purification from th...

  18. Probabilistic sensitivity analysis of biochemical reaction systems

    OpenAIRE

    Zhang, Hong-Xuan; Dempsey, William P.; Goutsias, John

    2009-01-01

    Sensitivity analysis is an indispensable tool for studying the robustness and fragility properties of biochemical reaction systems as well as for designing optimal approaches for selective perturbation and intervention. Deterministic sensitivity analysis techniques, using derivatives of the system response, have been extensively used in the literature. However, these techniques suffer from several drawbacks, which must be carefully considered before using them in problems of systems biology. ...

  19. Biochemical and functional characterisation of casein and whey protein hydrolysates.

    OpenAIRE

    Ven, van de, P.M.

    2002-01-01

    Whey protein and sodium caseinate were hydrolysed with commercially available enzyme preparations. The resulting hydrolysates were characterised using several analytical characterisation methods and by determination of several functional properties. Subsequently, correlations between the biochemical characteristics themselves and between biochemical and functional properties were studied using multivariate regression analysis.Biochemical characteristics of hydrolysates were determined using u...

  20. [Biochemical antenatal screening for fetal anomalies.].

    Science.gov (United States)

    Torfadóttir, G; Jónsson, J J

    2001-05-01

    Biochemical antenatal screening started 30 years ago. Initially, the goal was to detect neural tube defects by measuring a-fetoprotein in maternal serum (MS-AFP) and amniotic fluid (AF-AFP). The serendipitous discovery of an association between low AFP maternal serum concentration and chromosomal anomalies resulted in increased research interest in biochemical screening in pregnancy. Subsequently double, triple or quadruple tests in 2nd trimester of pregnancy became widely used in combination with fetal chromosome determination in at risk individuals. In Iceland, antenatal screening for chromosomal anomalies has essentially been based on fetal chromosome studies offered to pregnant women 35 years or older. This strategy needs to be revised. Recently first trimester biochemical screening based on maternal serum pregnancy associated plasma protein A (MS-PAPP-A) and free b-human chorionic gonadotropin (MS-free b-hCG) and multivariate risk assessment has been developed. This screening test can be improved if done in conjunction with nuchal translucency measurements in an early sonography scan. PMID:17018982

  1. Electronic modulation of biochemical signal generation

    Science.gov (United States)

    Gordonov, Tanya; Kim, Eunkyoung; Cheng, Yi; Ben-Yoav, Hadar; Ghodssi, Reza; Rubloff, Gary; Yin, Jun-Jie; Payne, Gregory F.; Bentley, William E.

    2014-08-01

    Microelectronic devices that contain biological components are typically used to interrogate biology rather than control biological function. Patterned assemblies of proteins and cells have, however, been used for in vitro metabolic engineering, where coordinated biochemical pathways allow cell metabolism to be characterized and potentially controlled on a chip. Such devices form part of technologies that attempt to recreate animal and human physiological functions on a chip and could be used to revolutionize drug development. These ambitious goals will, however, require new biofabrication methodologies that help connect microelectronics and biological systems and yield new approaches to device assembly and communication. Here, we report the electrically mediated assembly, interrogation and control of a multi-domain fusion protein that produces a bacterial signalling molecule. The biological system can be electrically tuned using a natural redox molecule, and its biochemical response is shown to provide the signalling cues to drive bacterial population behaviour. We show that the biochemical output of the system correlates with the electrical input charge, which suggests that electrical inputs could be used to control complex on-chip biological processes.

  2. Hydrogel-based piezoresistive biochemical microsensors

    Science.gov (United States)

    Guenther, Margarita; Schulz, Volker; Gerlach, Gerald; Wallmersperger, Thomas; Solzbacher, Florian; Magda, Jules J.; Tathireddy, Prashant; Lin, Genyao; Orthner, Michael P.

    2010-04-01

    This work is motivated by a demand for inexpensive, robust and reliable biochemical sensors with high signal reproducibility and long-term-stable sensitivity, especially for medical applications. Micro-fabricated sensors can provide continuous monitoring and on-line control of analyte concentrations in ambient aqueous solutions. The piezoresistive biochemical sensor containing a special biocompatible polymer (hydrogel) with a sharp volume phase transition in the neutral physiological pH range near 7.4 can detect a specific analyte, for example glucose. Thereby the hydrogel-based biochemical sensors are useful for the diagnosis and monitoring of diabetes. The response of the glucosesensitive hydrogel was studied at different regimes of the glucose concentration change and of the solution supply. Sensor response time and accuracy with which a sensor can track gradual changes in glucose was estimated. Additionally, the influence of various recommended sterilization methods on the gel swelling properties and on the mechano-electrical transducer of the pH-sensors has been evaluated in order to choose the most optimal sterilization method for the implantable sensors. It has been shown that there is no negative effect of gamma irradiation with a dose of 25.7 kGy on the hydrogel sensitivity. In order to achieve an optimum between sensor signal amplitude and sensor response time, corresponding calibration and measurement procedures have been proposed and evaluated for the chemical sensors.

  3. The effects of Crataegus aronia var. dentata Browicz extract on biochemical indices and apoptosis in partially hepatectomized liver in rats

    OpenAIRE

    Keskin, Nazan; Ramazan MAMMADOV; Ili, Pinar

    2012-01-01

    Crataegus species have been widely used in herbal medicine, especially for the hearth diseases. In the present study, the effect of Crataegus aronia var. dentata Browicz extract on partially hepatectomized rats was investigated with biochemical and TUNEL apoptosis assays. The extracts of the plant at the concentrations of 0.5 and 1 ml/100 g body weight/day were administered orally to the two experimental groups including partially hepatectomized rats for 42 days. At the end of the experimenta...

  4. High-throughput assays of leloir-glycosyltransferase reactions: The applications of rYND1 in glycotechnology.

    Science.gov (United States)

    Li, Yijun; Hou, Jin; Wang, Fengshan; Sheng, Juzheng

    2016-06-10

    Glycosyltransferases (GTs) play a critical role in the enzymatic and chemoenzymatic synthesis of oligosaccharides and glycoconjugates. However, the development of these synthetic approaches has been limited by a lack of sensitive screening methods for the isolation of novel natural GTs or their active variants. Herein, we describe the results of our investigation towards the soluble expression and potential application of the Saccharomyces cerevisiae apyrase YND1. By replacing the hydrophobic transmembrane domain of YND1 with three glycine-serine repeats, this protein was successfully expressed in a soluble form in Escherichia coli. This new protein was then used to develop a two-step nucleoside diphosphate (NDP)-based Leloir-GT high-throughput assay. Purified rYND1 was initially added to a GT reaction to hydrolyze NDP to nucleoside phosphate plus inorganic phosphate, which was determined using a phosphorus molybdenum blue chromogenic reaction. Purified rYND1 was shown to have a positive effect on saccharide synthesis by eliminating the potential by-product inhibition from NDP. Most of the mono-sugar donors used for Leloir-GTs are activated by uridine diphosphate and guanosine diphosphate, which can be catalyzed by rYND1. The rYND1 is amenable to screening methods and could be applied to a wide range of Leloir-GT-catalyzed reactions, therefore representing a remarkable step forward in glycotechnology. PMID:27059478

  5. A substrate-optimized electrophoretic mobility shift assay for ADAM12

    DEFF Research Database (Denmark)

    Kotzsch, Alexander; Skovgaard, Tine; Buus, Uwe;

    2014-01-01

    long been investigated as pharmaceutical drug targets; however, due to lack of potency and in vivo side effects, none of the small-molecule inhibitors discovered so far has made it beyond clinical testing. Ongoing research on novel selective inhibitors of ADAMs requires reliable biochemical assays to...... validate molecular probes from large-scale screening efforts. Here we describe an electrophoretic mobility shift assay for ADAM12 based on the identification of an optimized peptide substrate that is characterized by excellent performance and reproducibility....

  6. Data set of optimal parameters for colorimetric red assay of epoxide hydrolase activity.

    Science.gov (United States)

    de Oliveira, Gabriel Stephani; Adriani, Patricia Pereira; Borges, Flavia Garcia; Lopes, Adriana Rios; Campana, Patricia T; Chambergo, Felipe S

    2016-09-01

    The data presented in this article are related to the research article entitled "Epoxide hydrolase of Trichoderma reesei: Biochemical properties and conformational characterization" [1]. Epoxide hydrolases (EHs) are enzymes that catalyze the hydrolysis of epoxides to the corresponding vicinal diols. This article describes the optimal parameters for the colorimetric red assay to determine the enzymatic activity, with an emphasis on the characterization of the kinetic parameters, pH optimum and thermal stability of this enzyme. The effects of reagents that are not resistant to oxidation by sodium periodate on the reactions can generate false positives and interfere with the final results of the red assay. PMID:27366781

  7. Determination of estrogenic/antiestrogenic potential of antifertility substances using rat uterine peroxidase assay.

    Science.gov (United States)

    Johri, R K; Pahwa, G S; Sharma, S C; Zutshi, U

    1991-11-01

    The effect of three compounds (clomiphene citrate, centchroman, embelin) and plant-derived methanolic extracts (Abutilon indicum and Butea monosperma) was studied on uterotropic and uterine peroxidase activities in ovariectomized rats. It was observed that these two parameters were highly correlated in response to treatment with these test materials and also to estradiol. It was suggested that the uterine peroxidase assay could be utilized as a biochemical parameter in the screening of new antifertility agents for their estrogenic/antiestrogenic properties. PMID:1665776

  8. Homotypic Lysosome Fusion in Macrophages: Analysis Using an In Vitro Assay

    OpenAIRE

    Diane M Ward; Jonathan D Leslie; Kaplan, Jerry

    1997-01-01

    Lysosomes are dynamic structures capable of fusing with endosomes as well as other lysosomes. We examined the biochemical requirements for homotypic lysosome fusion in vitro using lysosomes obtained from rabbit alveolar macrophages or the cultured macrophage-like cell line, J774E. The in vitro assay measures the formation of a biotinylated HRP–avidin conjugate, in which biotinylated HRP and avidin were accumulated in lysosomes by receptor-mediated endocytosis. We determined that lysosome fusi...

  9. 两种显色培养基分离阪崎肠杆菌的应用评价%Evaluation on the application about two kinds of chromogenic medium for isolating cronobacter sakazakii

    Institute of Scientific and Technical Information of China (English)

    罗寿军

    2014-01-01

    目的:评价环凯阪崎肠杆菌显色培养基(HKDFIA)和科玛嘉阪崎肠杆菌显色培养基(CMDFIA)的应用效果,为食品中检测阪崎肠杆菌选用培养基提供依据。方法按照 GB/T 4789.40-2010食品卫生微生物学检验阪崎肠杆菌检验,进行阪崎肠杆菌分离及生化鉴定,并分析培养基的分离效果。结果36份样品中,检出阪崎肠杆菌2份,检出率为5.56%;HKDFI 平板和 CMDFI 平板阳性符合率为100%,疑似菌落检出率分别为16.67%和13.89%(P >0.05)。结论HKDFIA 和 CMDFIA 用于培养分离阪崎肠杆菌均具有良好的效果,HKDFIA 的性能已达到国外同类产品的水平,可以作为食品中检验阪崎肠杆的选择培养基。%Objective To evaluate the application value of chromogenic medium HuanKaiagar cronobacter sakazakii(HKDFIA)and chromogenic medium CHROMagar cronobacter sakazakii(CMDFIA),and provide basis to select appropriate medium for isolating cronobacter sakazakii in foods.Methods The samples were tested,isolated and identified HKDFIA and CMDFIA according to the national standard.Results Two strains of cronobacter sakaza-kii were identified from 36 samples with the detection ratio as 5.56%;The coincidence of positive symbol rate of HKDFIA and CMDFIA was 100%.The detection rate of suspected colonies were 16.67% and 13.89%,respectively (P >0.05).Conclusion Both HKDFIA and CMDFIA are effective for isolating cronobacter sakazakii in foods.HK-DFIA is almost at the same level of those imported from abroad,it can be a appropriate medium for cronobacter saka-zakii in foods.

  10. Time-correlated single photon counting: an advancing technique in a plate reader for assay development and high throughput screening

    Science.gov (United States)

    Näther, Dirk U.; Fenske, Roger; Hurteaux, Reynald; Majno, Sandra; Smith, S. Desmond

    2006-10-01

    A new plate reader (Nanotaurus) has been developed by Edinburgh Instruments that has the principle design features of a confocal microscope and utilises the technique of Time Correlated Single Photon Counting for data acquisition. The advantages of Fluorescence Lifetime Measurements in the nanosecond time scale and analysis methods to recover lifetime parameters are discussed based on experimental data. First working assays using changes of lifetime parameters are presented that clearly demonstrate the advantages of the new instrument for biochemical assays and show strong promise for cell-based assays, by utilising the independence of lifetime parameters from sample volume and concentration.

  11. Reconfigurable microfluidic dilution for high-throughput quantitative assays.

    Science.gov (United States)

    Fan, Jinzhen; Li, Baoqing; Xing, Siyuan; Pan, Tingrui

    2015-06-21

    This paper reports a reconfigurable microfluidic dilution device for high-throughput quantitative assays, which can easily produce discrete logarithmic/binary concentration profiles ranging from 1 to 100-fold dilution in parallel from a fixed sample volume (e.g., 10 μL) without any assistance of continuous fluidic pump or robotic automation. The integrated dilution generation chip consists of switchable distribution and collection channels, metering reservoirs, reaction chambers, and pressure-activatable Laplace valves. Following the sequential loading of a sample, a diluent, and a detection reagent into their individual metering chambers, the top microfluidic layer can be reconfigured to collect the metered chemicals into the reaction chambers in parallel, where detection will be conducted. To facilitate mixing and reaction in the microchambers, two acoustic microstreaming actuation mechanisms have been investigated for easy integrability and accessibility. Furthermore, the microfluidic dilution generator has been characterized by both colorimetric and fluorescent means. A further demonstration of the generic usage of the quantitative dilution chip has utilized the commonly available bicinchoninic acid (BCA) assay to analyse the protein concentrations of human tissue extracts. In brief, the microfluidic dilution generator offers a high-throughput high-efficiency quantitative analytical alternative to conventional quantitative assay platforms, by simple manipulation of a minute amount of chemicals in a compact microfluidic device with minimal equipment requirement, which can serve as a facile tool for biochemical and biological analyses in regular laboratories, point-of-care settings and low-resource environments. PMID:25994379

  12. Combined HPLC-CUPRAC (cupric ion reducing antioxidant capacity) assay of parsley, celery leaves, and nettle.

    Science.gov (United States)

    Yildiz, Leyla; Başkan, Kevser Sözgen; Tütem, Esma; Apak, Reşat

    2008-10-19

    This study aims to identify the essential antioxidant compounds present in parsley (Petroselinum sativum) and celery (Apium graveolens) leaves belonging to the Umbelliferae (Apiaceae) family, and in stinging nettle (Urtica dioica) belonging to Urticaceae family, to measure the total antioxidant capacity (TAC) of these compounds with CUPRAC (cupric ion reducing antioxidant capacity) and ABTS spectrophotometric methods, and to correlate the TAC with high performance liquid chromatography (HPLC) findings. The CUPRAC spectrophotometric method of TAC assay using copper(II)-neocuproine (2,9-dimethyl-1,10-phenanthroline) as the chromogenic oxidant was developed in our laboratories. The individual antioxidant constituents of plant extracts were identified and quantified by HPLC on a C18 column using a modified mobile phase of gradient elution comprised of MeOH-0.2% o-phosphoric acid and UV detection for polyphenols at 280 nm. The TAC values of HPLC-quantified antioxidant constituents were found, and compared for the first time with those found by CUPRAC. The TAC of HPLC-quantified compounds accounted for a relatively high percentage of the observed CUPRAC capacities of plant extracts, namely 81% of nettle, 60-77% of parsley (in different hydrolyzates of extract and solid sample), and 41-57% of celery leaves (in different hydrolyzates). The CUPRAC total capacities of the 70% MeOH extracts of studied plants (in the units of mmol trolox g(-1)plant) were in the order: celery leaves>nettle>parsley. The TAC calculated with the aid of HPLC-spectrophotometry did not compensate for 100% of the CUPRAC total capacities, because all flavonoid glycosides subjected to hydrolysis were either not detectable with HPLC, or not converted to the corresponding aglycons (i.e., easily detectable and quantifiable with HPLC) during the hydrolysis step. PMID:18804638

  13. An assay for determining minimal concentrations of antibiotics that drive horizontal transfer of resistance.

    Science.gov (United States)

    Jutkina, Jekaterina; Rutgersson, Carolin; Flach, Carl-Fredrik; Larsson, D G Joakim

    2016-04-01

    Ability to understand the factors driving horizontal transfer of antibiotic resistance from unknown, harmless bacteria to pathogens is crucial in order to tackle the growing resistance problem. However, current methods to measure effects of stressors on horizontal gene transfer have limitations and often fall short, as the estimated endpoints can be a mix of both the number of transfer events and clonal growth of transconjugants. Our aim was therefore to achieve a proper strategy for assessing the minimal concentration of a stressor (exemplified by tetracycline) that drives horizontal transfer of antibiotic resistance from a complex community to a model pathogen. Conditions were optimized to improve a culture-based approach using the bacterial community of treated sewage effluent as donor, and fluorescent, traceable Escherichia coli as recipient. Reduced level of background resistance, differentiation of isolates as well as decreased risk for measuring effects of selection were achieved through the use of chromogenic medium, optimization of conjugation time as well as applying a different antibiotic for isolation of transconjugants than the one tested for its ability to drive transfer. Using this assay, we showed that a very low concentration of tetracycline, 10μg/L i.e. 150 times below the minimal inhibitory concentration of the recipient, promoted horizontal transfer of multiple antibiotic-resistance determinants. Higher concentrations favoured selection of a tetracycline-resistance phenotype along with a decline in the number of detectable transfer events. The described method can be used to evaluate different environmental conditions and factors that trigger horizontal dissemination of mobile resistance elements, eventually resulting in the formation of drug-resistant pathogens. PMID:26802341

  14. Biochemical Network Stochastic Simulator (BioNetS: software for stochastic modeling of biochemical networks

    Directory of Open Access Journals (Sweden)

    Elston Timothy C

    2004-03-01

    Full Text Available Abstract Background Intrinsic fluctuations due to the stochastic nature of biochemical reactions can have large effects on the response of biochemical networks. This is particularly true for pathways that involve transcriptional regulation, where generally there are two copies of each gene and the number of messenger RNA (mRNA molecules can be small. Therefore, there is a need for computational tools for developing and investigating stochastic models of biochemical networks. Results We have developed the software package Biochemical Network Stochastic Simulator (BioNetS for efficientlyand accurately simulating stochastic models of biochemical networks. BioNetS has a graphical user interface that allows models to be entered in a straightforward manner, and allows the user to specify the type of random variable (discrete or continuous for each chemical species in the network. The discrete variables are simulated using an efficient implementation of the Gillespie algorithm. For the continuous random variables, BioNetS constructs and numerically solvesthe appropriate chemical Langevin equations. The software package has been developed to scale efficiently with network size, thereby allowing large systems to be studied. BioNetS runs as a BioSpice agent and can be downloaded from http://www.biospice.org. BioNetS also can be run as a stand alone package. All the required files are accessible from http://x.amath.unc.edu/BioNetS. Conclusions We have developed BioNetS to be a reliable tool for studying the stochastic dynamics of large biochemical networks. Important features of BioNetS are its ability to handle hybrid models that consist of both continuous and discrete random variables and its ability to model cell growth and division. We have verified the accuracy and efficiency of the numerical methods by considering several test systems.

  15. Development of a loop-mediated Isothermal amplification assay for sensitive and rapid detection of Vibrio parahaemolyticus

    Directory of Open Access Journals (Sweden)

    Kawahara Ryuji

    2008-09-01

    Full Text Available Abstract Background Vibrio parahaemolyticus is a marine seafood-borne pathogen causing gastrointestinal disorders in humans. Thermostable direct hemolysin (TDH and TDH-related hemolysin (TRH are known as major virulence determinants of V. parahaemolyticus. Most V. parahaemolyticus isolates from the environment do not produce TDH or TRH. Total V. parahaemolyticus has been used as an indicator for control of seafood contamination toward prevention of infection. Detection of total V. parahaemolyticus using conventional culture- and biochemical-based assays is time-consuming and laborious, requiring more than three days. Thus, we developed a novel and highly specific loop-mediated isothermal amplification (LAMP assay for the sensitive and rapid detection of Vibrio parahaemolyticus. Results The assay provided markedly more sensitive and rapid detection of V. parahaemolyticus strains than conventional biochemical and PCR assays. The assay correctly identified 143 V. parahaemolyticus strains, but did not detect 33 non-parahaemolyticus Vibrio and 56 non-Vibrio strains. Sensitivity of the LAMP assay for direct detection of V. parahaemolyticus in pure cultures and in spiked shrimp samples was 5.3 × 102 CFU per ml/g (2.0 CFU per reaction. The sensitivity of the LAMP assay was 10-fold more sensitive than that of the conventional PCR assay. The LAMP assay was markedly faster, requiring for amplification 13–22 min in a single colony on TCBS agar from each of 143 V. parahaemolyticus strains and less than 35 min in spiked shrimp samples. The LAMP assay for detection of V. parahaemolyticus required less than 40 min in a single colony on thiosulfate citrate bile salt sucrose (TCBS agar and 60 min in spiked shrimp samples from the beginning of DNA extraction to final determination. Conclusion The LAMP assay is a sensitive, rapid and simple tool for the detection of V. parahaemolyticus and will facilitate the surveillance for control of contamination of V

  16. Chromosome aberration assays in Allium

    Energy Technology Data Exchange (ETDEWEB)

    Grant, W.F.

    1982-01-01

    The common onion (Allium cepa) is an excellent plant for the assay of chromosome aberrations after chemical treatment. Other species of Allium (A. cepa var. proliferum, A. carinatum, A. fistulosum and A. sativum) have also been used but to a much lesser extent. Protocols have been given for using root tips from either bulbs or seeds of Allium cepa to study the cytological end-points, such as chromosome breaks and exchanges, which follow the testing of chemicals in somatic cells. It is considered that both mitotic and meiotic end-points should be used to a greater extent in assaying the cytogenetic effects of a chemical. From a literature survey, 148 chemicals are tabulated that have been assayed in 164 Allium tests for their clastogenic effect. Of the 164 assays which have been carried out, 75 are reported as giving a positive reaction, 49 positive and with a dose response, 1 positive and temperature-related, 9 borderline positive, and 30 negative; 76% of the chemicals gave a definite positive response. It is proposed that the Allium test be included among those tests routinely used for assessing chromosomal damage induced by chemicals.

  17. Bacterial mutagenicity assays: test methods.

    Science.gov (United States)

    Gatehouse, David

    2012-01-01

    The most widely used assays for detecting chemically induced gene mutations are those employing bacteria. The plate incorporation assay using various Salmonella typhimurium LT2 and E. coli WP2 strains is a short-term bacterial reverse mutation assay specifically designed to detect a wide range of chemical substances capable of causing DNA damage leading to gene mutations. The test is used worldwide as an initial screen to determine the mutagenic potential of new chemicals and drugs.The test uses several strains of S. typhimurium which carry different mutations in various genes of the histidine operon, and E. coli which carry the same AT base pair at the critical mutation site within the trpE gene. These mutations act as hot spots for mutagens that cause DNA damage via different mechanisms. When these auxotrophic bacterial strains are grown on a minimal media agar plates containing a trace of the required amino-acid (histidine or tryptophan), only those bacteria that revert to amino-acid independence (His(+) or Tryp(+)) will grow to form visible colonies. The number of spontaneously induced revertant colonies per plate is relatively constant. However, when a mutagen is added to the plate, the number of revertant colonies per plate is increased, usually in a dose-related manner.This chapter provides detailed procedures for performing the test in the presence and absence of a metabolic activation system (S9-mix), including advice on specific assay variations and any technical problems. PMID:22147566

  18. Assays for B lymphocyte function.

    Science.gov (United States)

    Bondada, Subbarao; Robertson, Darrell A

    2003-11-01

    This unit describes the antigenic stimulation of in vitro antibody production by B cells and the subsequent measurement of secreted antibodies. The first basic protocol is a generalized system for inducing in vitro antibody production and can accommodate various types of antigens under study. Secreted antibodies can then be measured with an enzyme-linked immunosorbent assay (ELISA) or other soluble-antibody detection systems. Alternatively, the number of antibody-producing cells can be quantified by plaque-forming cell (PFC) assays presented in this unit: the Cunningham-Szenberg and the Jerne-Nordin techniques. Both methods employ specially prepared slide chambers, described here, in which the antibody-producing B cells are mixed with complement and indicator sheep red blood cells (SRBC), or with trinitrophenol-modified SRBC (TNP-SRBC), with subsequent lysis and counting of plaques. Because IgM antibodies fix complement efficiently, whereas IgG and IgA antibodies do not, unmodified PFC assays measure only IgM antibodies. The assay can be modified, however, to measure all classes of antibodies or to enumerate total immunoglobulin-secreting B cells, as described in alternate protocols. Yet another method of measuring the number of antibody-producing B cells (in a class-specific fashion) is to use the ELISPOT technique described in UNIT 7.14. The resting B cells used in these procedures are prepared as described in the final support protocols for Percoll gradient centrifugation. PMID:18432909

  19. BNDB – The Biochemical Network Database

    Directory of Open Access Journals (Sweden)

    Kaufmann Michael

    2007-10-01

    Full Text Available Abstract Background Technological advances in high-throughput techniques and efficient data acquisition methods have resulted in a massive amount of life science data. The data is stored in numerous databases that have been established over the last decades and are essential resources for scientists nowadays. However, the diversity of the databases and the underlying data models make it difficult to combine this information for solving complex problems in systems biology. Currently, researchers typically have to browse several, often highly focused, databases to obtain the required information. Hence, there is a pressing need for more efficient systems for integrating, analyzing, and interpreting these data. The standardization and virtual consolidation of the databases is a major challenge resulting in a unified access to a variety of data sources. Description We present the Biochemical Network Database (BNDB, a powerful relational database platform, allowing a complete semantic integration of an extensive collection of external databases. BNDB is built upon a comprehensive and extensible object model called BioCore, which is powerful enough to model most known biochemical processes and at the same time easily extensible to be adapted to new biological concepts. Besides a web interface for the search and curation of the data, a Java-based viewer (BiNA provides a powerful platform-independent visualization and navigation of the data. BiNA uses sophisticated graph layout algorithms for an interactive visualization and navigation of BNDB. Conclusion BNDB allows a simple, unified access to a variety of external data sources. Its tight integration with the biochemical network library BN++ offers the possibility for import, integration, analysis, and visualization of the data. BNDB is freely accessible at http://www.bndb.org.

  20. Biochemical changes in blood under Cr6+

    Directory of Open Access Journals (Sweden)

    Kuzenko E.V.

    2013-01-01

    Full Text Available Background. For the manufacture of dentures many different alloys containing chromium are used. Interaction with oral fluid, organic acids and food, results in formation of Cr3+, Cr6+ ions, but their influence on the whole organism is poorly investigated. Objective. To analyze the biochemical changes in blood plasma during the influence of Cr6+ ions. Methods. 15 animals of experimental group were receiving drinking water with potassium dichromate in a dose of 0,2 mol/l. Rats of control group (5 individuals drank usual drinking water. Animals were led out of experiment on the 20th, 40th and 60th days after the beginning of introduction of potassium dichromate. Results. It was established that at the beginning of experiment the blood biochemical indicators of control and the 1st experimental groups differed by its content. Increase of urea concentration led to suspicion about violation of a glomerular filtration, damage of a kidney parenchyma and tissue disintegration. On the 20th and 40th days of experiment the symptoms of acidosis and increase of potassium ions concentration in blood plasma were defined. Continuous and dynamic increase of creatin-phosphokinase was observed during 60 days of experiment. Conclusion. Biochemical changes in blood under the influence of Cr6+ ions evidence their toxic action on an organism. Especial concern is caused by changes of ionic composition and increase of the atherogenic index of blood plasma on the 40th day of experiment. Substantial increase of the creatin-phosphokinase level indicates general somatic influence of chromium ions.

  1. Fluctuation preserving coarse graining for biochemical systems

    CERN Document Server

    Altaner, Bernhard

    2011-01-01

    Finite stochastic Markov models play a major role for modelling biochemical pathways. Such models are a coarse-grained description of the underlying microscopic dynamics and can be considered mesoscopic. The level of coarse-graining is to a certain extend arbitrary since it depends on the resolution of accomodating measurements. Here, we present a way to simplify such stochastic descriptions, which preserves both the meso-micro and the meso-macro connection. The former is achieved by demanding locality, the latter by considering cycles on the network of states. Using single- and multicycle examples we demonstrate how our new method preserves fluctuations of observables much better than na\\"ive approaches.

  2. Radiation treatment of drugs, biochemicals and vaccines

    International Nuclear Information System (INIS)

    The concise and tabulated review reports experimental results on the effects of radiation treatment on drugs, vaccines, biochemicals and adjuvants including enzymes as well. Irradiation was mostly performed by γ-radiation using 60Co and to a lesser extent by 137Cs, 182Ta, X-rays and accelerators. Ionizing radiation proved to be a useful tool for sterilization and inactivation in producing drugs, vaccines, and bioactive agents and will contribute to realize procedures difficultly solvable as to engineering and economy, respectively. 124 refs

  3. Induced biochemical conversions of heavy crude oils

    International Nuclear Information System (INIS)

    Products formed during multiple interactions of microorganisms with oils fall into two major categories: those formed due to the action of indigenous microorganisms under reservoir conditions over geological periods of time and those products which are generated by the action of introduced organisms. The extreme end product of the first category is the production of heavy 'biodegraded' crudes. The extreme end product of the second category is the production of reduced sulfates due to the introduction of sulfate-reducing bacteria which may lead to the souring of a field. There is, however, a select group of microorganisms whose action on the crudes is beneficial. The interactions between such microorganisms and different crude oils occur through complex biochemical and chemical reactions. These reactions depend on multiple variables within and at the interface of a multicomponent system consisting of organic, aqueous, and inorganic components. Studies, carried out in this laboratory (BNL) of biochemical and chemical reactions in crude oils which involve extremophilic organisms (organisms which thrive in extreme environments), have shown that the reactions are not random and follow distinct trends. These trends can be categorized. The use of a group of characteristic chemical markers, such as mass spectrometric fragmentation patterns of light and heavy hydrocarbons, heterocyclic and organometallic compounds, as well as total trace metal and heteroatom contents of crude oils before and after the biochemical treatment allows to follow the type and the extent of chemical changes which occur during the biochemical conversion of heavy crude oils by microorganisms. The bioconversion involves multiple, simultaneous, and/or concurrent chemical reactions in which the microorganisms serve as biocatalysts. In this sense, the biocatalysts are active in a reaction medium which depends on the chemical composition of the crude and the selectivity of the biocatalyst. Thus, the

  4. Biochemical Disincentives to Fertilizing Cellulosic Ethanol Crops

    Science.gov (United States)

    Gallagher, M. E.; Hockaday, W. C.; Snapp, S.; McSwiney, C.; Baldock, J.

    2010-12-01

    Corn grain biofuel crops produce the highest yields when the cropping ecosystem is not nitrogen (N)-limited, achieved by application of fertilizer. There are environmental consequences for excessive fertilizer application to crops, including greenhouse gas emissions, hypoxic “dead zones,” and health problems from N runoff into groundwater. The increase in corn acreage in response to demand for alternative fuels (i.e. ethanol) could exacerbate these problems, and divert food supplies to fuel production. A potential substitute for grain ethanol that could reduce some of these impacts is cellulosic ethanol. Cellulosic ethanol feedstocks include grasses (switchgrass), hardwoods, and crop residues (e.g. corn stover, wheat straw). It has been assumed that these feedstocks will require similar N fertilization rates to grain biofuel crops to maximize yields, but carbohydrate yield versus N application has not previously been monitored. We report the biochemical stocks (carbohydrate, protein, and lignin in Mg ha-1) of a corn ecosystem grown under varying N levels. We measured biochemical yield in Mg ha-1 within the grain, leaf and stem, and reproductive parts of corn plants grown at seven N fertilization rates (0-202 kg N ha-1), to evaluate the quantity and quality of these feedstocks across a N fertilization gradient. The N fertilization rate study was performed at the Kellogg Biological Station-Long Term Ecological Research Site (KBS-LTER) in Michigan. Biochemical stocks were measured using 13C nuclear magnetic resonance spectroscopy (NMR), combined with a molecular mixing model (Baldock et al. 2004). Carbohydrate and lignin are the main biochemicals of interest in ethanol production since carbohydrate is the ethanol feedstock, and lignin hinders the carbohydrate to ethanol conversion process. We show that corn residue carbohydrate yields respond only weakly to N fertilization compared to grain. Grain carbohydrate yields plateau in response to fertilization at

  5. Multiplex PCR and a chromogenic DNA macroarray for the detection of Listeria monocytogens, Staphylococcus aureus, Streptococcus agalactiae, Enterobacter sakazakii, Escherichia coli O157:H7, Vibrio parahaemolyticus, Salmonella spp. and Pseudomonas fluorescens in milk and meat samples.

    Science.gov (United States)

    Chiang, Yu-Cheng; Tsen, Hau-Yang; Chen, Hsin-Yen; Chang, Yu-Hsin; Lin, Chien-Ku; Chen, Chih-Yuan; Pai, Wan-Yu

    2012-01-01

    Food products, such as milk and meat products including cheese, milk powder, fermented milk, sausage, etc. are susceptible to the contamination by pathogenic and deteriorative bacteria. These bacteria include Listeria monocytogens, Staphylococcus aureus, Enterobacter sakazakii, Escherichia coli O157:H7, Salmonella spp., Vibrio parahaemolyticus, Streptococcus agalactiae and Pseudomonas fluorescens, etc. Traditional methods for the detection of these microorganisms are laborious and time consuming. Therefore, rapid and accurate diagnostic methods are needed. In this study, we designed the DNA probes and PCR primers for the detection of aforementioned microorganisms. By using two sets of multiplex PCR, followed by a chromogenic macroarray system, these organisms in milk or other food products could be simultaneously detected. When the system was used for the inspection of milk or meat homogenate containing 10(0) target cells per milliliter or gram of the sample, all these bacterial species could be identified after an 8h pre-enrichment step. The system consisting of a multiplex PCR step followed by macroarray allowed us to detect multiple target bacterial species simultaneously without the use of agarose gel electrophoresis. Compared to the commonly used multiplex PCR method, this approach has the additional advantage of detecting more bacterial strains because some bacterial strains generate PCR products with the same molecular sizes which can be differentiated by macroarray but not by electrophoresis. PMID:22101309

  6. A new selective chromogenic reagent for the spectrophotometric determination of thallium(I) and (III) and its separation using flotation and the solid-phase extraction on polyurethane foam.

    Science.gov (United States)

    Abou-El-Sherbini, Khaled S; Mostafa, Gamal A E; Hassanien, Mohamed M

    2003-09-01

    A new sensitive chromogenic reagent, 9,10-phenanthaquinone monoethylthiosemicarbazone (PET), has been synthesized and used in the spectrophotometric determination of Tl(III). In HNO3, H2SO4 or H3PO4 acids, PET can react immediately at room temperature with Tl(III) to form a red 2:1 complex with a maximum absorption at 516 nm. The different analytical parameters affecting the extraction and determination processes have been examined. The calibration curve was found to be linear over the range 0.2-10 microg cm(-3) with a molar absorptivity of 2.2 x 10(4) dm3 mol(-1) cm(-1). Sandell's sensitivity was found to be 0.0093 microg cm(-2). No interference from macroamounts of foreign ions was detected, except for Pd(II). However, Pd(II) does not affect the determination process, because its complex with PET has its lambda(max) at 625 nm. The proposed method has been applied to the determination of Tl(I and III) in synthetic and natural samples after separation by flotation (in oleic acid/kerosene) and solid-phase extraction (on polyurethane foam) techniques. The two methods were found to be accurate and not subject to random error, but solid-phase extraction was preferred because it is cheap, simpler and there is no contamination risk coming from flotation reagents. PMID:14516078

  7. Haematological and Serum Biochemical Parameters of Local Turkey Poults Fed Diets Containing Two Varieties of Sorghum

    Directory of Open Access Journals (Sweden)

    E.B. Etuk

    2012-12-01

    Full Text Available These studies were conducted to determine the effects of two varieties of sorghum, Samsorg 17 and ICSV 400 on the haematological and serum biochemical parameters of local turkey breeds, reared in Nigeria. Two hundred and sixteen poults were divided into 9 treatment groups of 24 each, which were further replicated thrice and fed starter diets containing Samsorg 17 and ICSV 400. Similar (P > 0.05 RBC and PCV values were obtained with the two diets. Samsorg 17 fed poults produced lower, though not significantly (P > 0.05 serum albumin, glucose, urea, creatinine, sodium, chloride, ALP, SGPT and SGOT values than those on ICSV 400 diet. Higher RBC, MCHC, MCH, MCV and PCV values were observed with Samsorg 17 fed turkeys than those on ICSV 400 diets. Serum glucose and creatinine decreased and SGOT increased with dietary sorghum. Similar (p > 0.05 Hb, WBC, MCHC, MCV and PCV values were obtained in all groups. Values of serum biochemical indices assayed except urea, calcium, potassium and chloride showed no significant (p > 0.05 differences among the treatment groups. It was therefore concluded that Samsorg 17 and ICSV 400 sorghum varieties could sustain local turkey production without any on toward effects on their haematological and serum biochemical indices.

  8. Tissue Residues, Hematological and Biochemical Effects of Tilmicosin in Broiler Chicken

    Directory of Open Access Journals (Sweden)

    Mossad Elsayed

    2014-01-01

    Full Text Available The aim of this study was to determine the blood and tissue concentrations profile and effect of tilmicosin on some hematological and biochemical parameters in broiler chicken. Fifty clinically healthy Hubbard chickens were orally administered 25 mg/kg BW of tilmicosin once daily for 5 consecutive days. Tissue residues of tilmicosin in slaughtered healthy chicken could not be detected by microbiological assay in all tested tissues except in lung (at 96 hours and liver and kidneys (at 72 hours after last administration. Tilmicosin caused temporary decrease in the RBCs and WBCs counts and has no effect on hemoglobin (Hb and packed cell volume concentration (PCV. Also, the effect of tilmicosin on some biochemical parameters was as follows: the concentrations of creatinine, uric acid, electrolytes (sodium, potassium, and calcium, glucose, AST, ALT, ALP, and HDL-cholesterol in the serum of treated chicken did not change in response to the repeated oral administration of tilmicosin. There were only a temporary significant decrease in total protein and albumin concentrations and a significant increase in cholesterol and triglycerides concentrations. Chicken must not be slaughtered before 4 days from the stopping of tilmicosin administration. Tilmicosin makes temporary changes on hematological and biochemical parameters in broiler chicken.

  9. Tissue Residues, Hematological and Biochemical Effects of Tilmicosin in Broiler Chicken

    Science.gov (United States)

    Elsayed, Mossad; Elkomy, Ashraf; Morad, Mohamed

    2014-01-01

    The aim of this study was to determine the blood and tissue concentrations profile and effect of tilmicosin on some hematological and biochemical parameters in broiler chicken. Fifty clinically healthy Hubbard chickens were orally administered 25 mg/kg BW of tilmicosin once daily for 5 consecutive days. Tissue residues of tilmicosin in slaughtered healthy chicken could not be detected by microbiological assay in all tested tissues except in lung (at 96 hours) and liver and kidneys (at 72 hours) after last administration. Tilmicosin caused temporary decrease in the RBCs and WBCs counts and has no effect on hemoglobin (Hb) and packed cell volume concentration (PCV). Also, the effect of tilmicosin on some biochemical parameters was as follows: the concentrations of creatinine, uric acid, electrolytes (sodium, potassium, and calcium), glucose, AST, ALT, ALP, and HDL-cholesterol in the serum of treated chicken did not change in response to the repeated oral administration of tilmicosin. There were only a temporary significant decrease in total protein and albumin concentrations and a significant increase in cholesterol and triglycerides concentrations. Chicken must not be slaughtered before 4 days from the stopping of tilmicosin administration. Tilmicosin makes temporary changes on hematological and biochemical parameters in broiler chicken. PMID:24808972

  10. The effects of Crataegus aronia var. dentata Browicz extract on biochemical indices and apoptosis in partially hepatectomized liver in rats.

    Science.gov (United States)

    Keskin, Nazan; Mammadov, Ramazan; Ili, Pinar

    2012-08-01

    Crataegus species have been widely used in herbal medicine, especially for the hearth diseases. In the present study, the effect of Crataegus aronia var. dentata Browicz extract on partially hepatectomized rats was investigated with biochemical and TUNEL apoptosis assays. The extracts of the plant at the concentrations of 0.5 and 1 ml/100 g body weight/day were administered orally to the two experimental groups including partially hepatectomized rats for 42 days. At the end of the experimental period, animals were sacrificed, blood was collected for the assessment of serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT), and the liver tissue was used for TUNEL assay. In biochemical assay, it was found a significant decrease in the levels of serum ALT and AST in the experimental groups. On the other hand, the plant extract did not cause any significant changes in the level of GGT in these groups. In apoptosis assay, TUNEL positive hepatocytes could not be detected in both experimental groups. The present findings can suggest that Crataegus aronia var. dentata Browicz extract can decrease the levels of serum ALT and AST and play a role in apoptosis of hepatocytes in the liver of partially hepatectomized rats. However, further studies are required to confirm the effects of the plant extract on hepatoprotection and apoptosis in the regenerating liver after partial hepatectomy in animal models. PMID:22938545

  11. Controlling variation in the comet assay

    OpenAIRE

    Collins, Andrew R; El Yamani, Naouale; Lorenzo, Yolanda; Shaposhnikov, Sergey; Brunborg, Gunnar; Azqueta, Amaya

    2014-01-01

    Variability of the comet assay is a serious issue, whether it occurs from experiment to experiment in the same laboratory, or between different laboratories analysing identical samples. Do we have to live with high variability, just because the comet assay is a biological assay rather than analytical chemistry? Numerous attempts have been made to limit variability by standardizing the assay protocol, and the critical steps in the assay have been identified; agarose concentration, duration of ...

  12. Biochemical research elucidating metabolic pathways in Pneumocystis*

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    Kaneshiro E.S.

    2010-12-01

    Full Text Available Advances in sequencing the Pneumocystis carinii genome have helped identify potential metabolic pathways operative in the organism. Also, data from characterizing the biochemical and physiological nature of these organisms now allow elucidation of metabolic pathways as well as pose new challenges and questions that require additional experiments. These experiments are being performed despite the difficulty in doing experiments directly on this pathogen that has yet to be subcultured indefinitely and produce mass numbers of cells in vitro. This article reviews biochemical approaches that have provided insights into several Pneumocystis metabolic pathways. It focuses on 1 S-adenosyl-L-methionine (AdoMet; SAM, which is a ubiquitous participant in numerous cellular reactions; 2 sterols: focusing on oxidosqualene cyclase that forms lanosterol in P. carinii; SAM:sterol C-24 methyltransferase that adds methyl groups at the C-24 position of the sterol side chain; and sterol 14α-demethylase that removes a methyl group at the C-14 position of the sterol nucleus; and 3 synthesis of ubiquinone homologs, which play a pivotal role in mitochondrial inner membrane and other cellular membrane electron transport.

  13. Biochemical mechanisms of laser vascular tissue fusion.

    Science.gov (United States)

    Guthrie, C R; Murray, L W; Kopchok, G E; Rosenbaum, D; White, R A

    1991-01-01

    This study examines the biochemical changes that occur in argon laser-fused canine veins compared with control segments of vein. Laser fusions were formed using 0.5 W argon laser energy (1100-1500 J/cm2). Immediately following tissue fusion, blood flow was reestablished to test the integrity of the welds. 1-mm3 sections of the anastomoses and control sections were minced and protein extraction was performed by solubilizing the tissue in hot SDS Laemmli gel sample buffer. The proteins were separated electrophoretically on 5 and 10% polyacylamide SDS gels and silver stained. The analysis demonstrated significant biochemical differences between control and lased veins. We noted increases in several proteins after laser welding: the putative beta chain of type V collagen (5/5 gels), the putative gamma chain of type I collagen (4/5 gels), a 156-kDa protein (based on collagen molecular weight standards) 7/7 gels), an 82-kDa protein (8/9 gels), and several proteins of lower molecular weight (3/8 gels). The increases may be due to crosslinking of lower molecular weight proteins, degradation of higher molecular weight proteins, or increased solubility of certain proteins. These findings suggest that laser welding may occur by formation of crosslinks or by denaturation and reannealment of structural proteins. PMID:1863584

  14. BIOCHEMICAL PROCESSES FOR GEOTHERMAL BRINE TREATMENT

    Energy Technology Data Exchange (ETDEWEB)

    PREMUZIC,E.T.; LIN,M.S.; BOHENEK,M.; JOSHI-TOPE,G.; ZHOU,W.; SHELENKOVA,L.; WILKE,R.

    1998-09-20

    As part of the DOE Geothermal Energy Program, BNL's Advanced Biochemical Processes for Geothermal Brines (ABPGB) project is aimed at the development of cost-efficient and environmentally acceptable technologies for the disposal of geothermal wastes. Extensive chemical studies of high and low salinity brines and precipitates have indicated that in addition to trace quantities of regulated substances, e.g., toxic metals such as arsenic and mercury, there are significant concentrations of valuable metals, including gold, silver and platinum. Further chemical and physical studies of the silica product have also shown that the produced silica is a valuable material with commercial potential. A combined biochemical and chemical technology is being developed which (1) solubilizes, separates, and removes environmentally regulated constituents in geothermal precipitates and brines (2) generates an amorphous silica product which may be used as feedstock for the production of revenue generating materials, (3) recover economically valuable trace metals and salts. Geothermal power resources which utilize low salinity brines and use the Stretford process for hydrogen sulfide abatement generate a contaminated sulfur cake. Combined technology converts such sulfur to a commercial grade sulfur, suitable for agricultural use. The R and D activities at BNL are conducted jointly with industrial parties in an effort focused on field applications.

  15. Biochemical processes for geothermal brine treatment

    Energy Technology Data Exchange (ETDEWEB)

    Premuzic, E.T.; Lin, M.S.; Bohenek, M.; Joshi-Tope, G.; Zhou, W.; Shelenkova, L.; Wilke, R.

    1998-08-01

    As part of the DOE Geothermal Energy Program, BNL`s Advanced Biochemical Processes for Geothermal Brines (ABPGB) project is aimed at the development of cost-efficient and environmentally acceptable technologies for the disposal of geothermal wastes. Extensive chemical studies of high and low salinity brines and precipitates have indicated that in addition to trace quantities of regulated substances, e.g., toxic metals such as arsenic and mercury, there are significant concentrations of valuable metals, including gold, silver and platinum. Further chemical and physical studies of the silica product have also shown that the produced silica is a valuable material with commercial potential. A combined biochemical and chemical technology is being developed which (1) solubilizes, separates, and removes environmentally regulated constituents in geothermal precipitates and brines, (2) generates an amorphous silica product which may be used as feedstock for the production of revenue generating materials, (3) recover economically valuable trace metals and salts. Geothermal power resources which utilize low salinity brines and use the Stretford process for hydrogen sulfide abatement generate a contaminated sulfur cake. Combined technology converts such sulfur to a commercial grade sulfur, suitable for agricultural use. The R and D activities at BNL are conducted jointly with industrial parties in an effort focused on field applications.

  16. Serum biochemical markers in carcinoma breast.

    Directory of Open Access Journals (Sweden)

    Seth R

    2003-08-01

    Full Text Available BACKGROUND: Despite the extensive research for many years throughout the world, the etiopathogenesis of cancer still remains obscure. For the early detection of carcinoma of various origins, a number of biochemical markers have been studied to evaluate the malignancy. AIM: To analyse serum gamma glutamyl transpeptidase (GGTP, lactate dehydrogenase (LDH and superoxide dismutase (SOD in carcinoma breast patients. SETTINGS & DESIGN: The serum biochemical markers were estimated in twenty five histopathologically confirmed patients with carcinoma breast and equal number of healthy age- matched individuals served as control. MATERIAL & METHODS: Serum gamma glutamyl transpeptidase (GGTP, lactate dehydrogenase (LDH and superoxide dismutase (SOD were estimated and their sensitivity determined. Statistics: Data was analysed with student′s ′t′-test and sensitivity score of these markers was determined. RESULTS & CONCLUSIONS: The mean serum GGTP, LDH and SOD activities in patients with carcinoma breast were tremendously increased as compared to controls, and a steady increase was observed in their activities from stage I through stage IV as well as following distant metastasis. Serum GGTP, LDH and SOD might prove to be most sensitive biomarkers in carcinoma breast in early detection of the disease.

  17. Automated saccharification assay for determination of digestibility in plant materials

    Directory of Open Access Journals (Sweden)

    Halpin Claire

    2010-10-01

    Full Text Available Abstract Background Cell wall resistance represents the main barrier for the production of second generation biofuels. The deconstruction of lignocellulose can provide sugars for the production of fuels or other industrial products through fermentation. Understanding the biochemical basis of the recalcitrance of cell walls to digestion will allow development of more effective and cost efficient ways to produce sugars from biomass. One approach is to identify plant genes that play a role in biomass recalcitrance, using association genetics. Such an approach requires a robust and reliable high throughput (HT assay for biomass digestibility, which can be used to screen the large numbers of samples involved in such studies. Results We developed a HT saccharification assay based on a robotic platform that can carry out in a 96-well plate format the enzymatic digestion and quantification of the released sugars. The handling of the biomass powder for weighing and formatting into 96 wells is performed by a robotic station, where the plant material is ground, delivered to the desired well in the plates and weighed with a precision of 0.1 mg. Once the plates are loaded, an automated liquid handling platform delivers an optional mild pretreatment ( Conclusions The automated assay systems are sensitive, robust and reliable. The system can reliably detect differences in the saccharification of plant tissues, and is able to process large number of samples with a minimum amount of human intervention. The automated system uncovered significant increases in the digestibility of certain lignin modified lines in a manner compatible with known effects of lignin modification on cell wall properties. We conclude that this automated assay platform is of sufficient sensitivity and reliability to undertake the screening of the large populations of plants necessary for mutant identification and genetic association studies.

  18. Development of On-Line High Performance Liquid Chromatography (HPLC-Biochemical Detection Methods as Tools in the Identification of Bioactives

    Directory of Open Access Journals (Sweden)

    Elizabeth Joubert

    2012-03-01

    Full Text Available Biochemical detection (BCD methods are commonly used to screen plant extracts for specific biological activities in batch assays. Traditionally, bioactives in the most active extracts were identified through time-consuming bio-assay guided fractionation until single active compounds could be isolated. Not only are isolation procedures often tedious, but they could also lead to artifact formation. On-line coupling of BCD assays to high performance liquid chromatography (HPLC is gaining ground as a high resolution screening technique to overcome problems associated with pre-isolation by measuring the effects of compounds post-column directly after separation. To date, several on-line HPLC-BCD assays, applied to whole plant extracts and mixtures, have been published. In this review the focus will fall on enzyme-based, receptor-based and antioxidant assays.

  19. Comet Assay in Cancer Chemoprevention.

    Science.gov (United States)

    Santoro, Raffaela; Ferraiuolo, Maria; Morgano, Gian Paolo; Muti, Paola; Strano, Sabrina

    2016-01-01

    The comet assay can be useful in monitoring DNA damage in single cells caused by exposure to genotoxic agents, such as those causing air, water, and soil pollution (e.g., pesticides, dioxins, electromagnetic fields) and chemo- and radiotherapy in cancer patients, or in the assessment of genoprotective effects of chemopreventive molecules. Therefore, it has particular importance in the fields of pharmacology and toxicology, and in both environmental and human biomonitoring. It allows the detection of single strand breaks as well as double-strand breaks and can be used in both normal and cancer cells. Here we describe the alkali method for comet assay, which allows to detect both single- and double-strand DNA breaks. PMID:26608293

  20. Nondestructive assay of sale materials

    International Nuclear Information System (INIS)

    This paper covers three primary areas: (1) reasons for performing nondestructive assay on SALE materials; (2) techniques used; and (3) discussion of investigators' revised results. The study shows that nondestructive calorimetric assay of plutonium offers a viable alternative to traditional wet chemical techniques. For these samples, the precision ranged from 0.4 to 0.6% with biases less than 0.2%. Thus, for those materials where sampling errors are the predominant source of uncertainty, this technique can provide improved accuracy and precision while saving time and money as well as reducing the amount of liquid wastes to be handled. In addition, high resolution gamma-ray spectroscopy measurements of solids can provide isotopic analysis data in a cost effective and timely manner. The timeliness of the method can be especially useful to the plant operator for production control and quality control measurements

  1. Assay of vitamin B12

    International Nuclear Information System (INIS)

    A radioassay is described for vitamin B12 which involves denaturing serum protein binding proteins with alkali. In the denaturation step a dithiopolyol and cyanide are used and in the intrinsic factor assay step a vitamin B12 analogue such as cobinamide is used to bind with any remaining serum proteins. The invention also includes a kit in which the dithiopolyol is provided in admixture with the alkali. The dithiopolyol may be dithiothreitol or dithioerythritol. (author)

  2. Mutual information in time-varying biochemical systems

    OpenAIRE

    Tostevin, Filipe; Wolde, Pieter Rein ten

    2010-01-01

    Cells must continuously sense and respond to time-varying environmental stimuli. These signals are transmitted and processed by biochemical signalling networks. However, the biochemical reactions making up these networks are intrinsically noisy, which limits the reliability of intracellular signalling. Here we use information theory to characterise the reliability of transmission of time-varying signals through elementary biochemical reactions in the presence of noise. We calculate the mutual...

  3. Possibilities and methods for biochemical assessment of radiation injury

    International Nuclear Information System (INIS)

    An extensitive review (77 references) is made of the application of biochemical diagnostic methods for assessment of radiation diseases. A brief characteristics of several biochemical indicators is given: deoxycytidine, thymidine, ρ-aminoisocarboxylic acid, DNA-ase, nucleic acids. Influence of such factors as age, sex, season etc. is studied by means of functional biochemical indicators as: creatine, triptophanic metabolites, 5-hydroxy-indolacetic acid, biogenic amines, serum proteins, enzymes, etc

  4. Conceptual Aspects of Theory Appraisal: Some Biochemical Examples

    Directory of Open Access Journals (Sweden)

    F. Michael Akeroyd

    1997-11-01

    Full Text Available This paper considers papers on conceptual analysis by Laudan (1981 and Whitt (1989 and relates them to three biochemical episodes: (1 the modern 'biochemical explanation' of acupuncture; (2 the chemio-osmotic hypothesis of oxidative phosphorylation; (3 the theory of the complete digestion of proteins in the gut. The advantages of including philosophical debate in chemical/biochemical undergraduate courses is then discussed.

  5. Biochemical characterization of the GM2 gangliosidosis B1 variant

    Directory of Open Access Journals (Sweden)

    J.C. Tutor

    2004-06-01

    Full Text Available The deficiency of the A isoenzyme of ß-hexosaminidase (Hex produced by different mutations of the gene that codes for the alpha subunit (Tay-Sachs disease has two variants with enzymological differences: the B variant consists of the absence of Hex A isoenzyme and the B1 variant produces an inactive Hex A isoenzyme for the hydrolysis of the GM2 ganglioside and synthetic substrates with negative charge. In contrast to the early childhood form of the B variant, the B1 variant appears at a later clinical stage (3 to 7 years of age with neurodegenerative symptoms leading to the death of the patient in the second decade of life. The most frequent mutation responsible for the GM2 gangliosidosis B1 variant is R178H, which has a widespread geographic and ethnic distribution. The highest incidence has been described in Portugal, which has been suggested as the point of origin of this mutation. Biochemical characterization of this lysosomal disease is carried out using negatively charged synthetic alpha subunit-specific sulfated substrates, since Hex A isoenzyme heat-inactivation assays are not applicable. However, the determination of the apparent activation energy of Hex using the neutral substrate 3,3'-dichlorophenolsulfonphthaleinyl N-acetyl-ß-D-glucosaminide, may offer a valid alternative. The presence of an alpha subunit in the alphaß heterodimer Hex A means that its activation energy (41.8 kJ/mol is significantly lower than that of the ßß homodimer Hex B (75.1 kJ/mol; however, as mutation inactivates the alpha subunit, the Hex A of the B1 variant presents an activation energy that is similar to that of the Hex B isoenzyme.

  6. Dynamic analysis of biochemical network using complex network method

    Directory of Open Access Journals (Sweden)

    Wang Shuqiang

    2015-01-01

    Full Text Available In this study, the stochastic biochemical reaction model is proposed based on the law of mass action and complex network theory. The dynamics of biochemical reaction system is presented as a set of non-linear differential equations and analyzed at the molecular-scale. Given the initial state and the evolution rules of the biochemical reaction system, the system can achieve homeostasis. Compared with random graph, the biochemical reaction network has larger information capacity and is more efficient in information transmission. This is consistent with theory of evolution.

  7. Category analysis: from biochemical mechanics to astrophysics

    International Nuclear Information System (INIS)

    Full text: One of the main goals of this report is to bridge the gap between computer modelling and group analysis of nonlinear partial differential equations. But we can work with a category of groups rather than a Lie group. In view of the experience of the past development of the relation between mathematics, mechanics and physics, the categorical extension may be justified that one day categoric structures will be as important as groups are today. Also our aim is the application of the same category-theoretic methods in biochemical mechanics and astrophysics. As examples we consider the category analysis of material models for concrete, wood and reinforcing or prestressing steel, on the one hand, and process of the linear and circular polarization of the cosmic microwave background radiation due to the quantum effects of electromagnetic field in anisotropic Bianchi-type cosmological models, on the other hand. (author)

  8. Prions: the danger of biochemical weapons

    Directory of Open Access Journals (Sweden)

    Eric Almeida Xavier

    2014-09-01

    Full Text Available The knowledge of biotechnology increases the risk of using biochemical weapons for mass destruction. Prions are unprecedented infectious pathogens that cause a group of fatal neurodegenerative diseases by a novel mechanism. They are transmissible particles that are devoid of nucleic acid. Due to their singular characteristics, Prions emerge as potential danger since they can be used in the development of such weapons. Prions cause fatal infectious diseases, and to date there is no therapeutic or prophylactic approach against these diseases. Furthermore, Prions are resistant to food-preparation treatments such as high heat and can find their way from the digestive system into the nervous system; recombinant Prions are infectious either bound to soil particles or in aerosols. Therefore, lethal Prions can be developed by malicious researchers who could use it to attack political enemies since such weapons cause diseases that could be above suspicion.

  9. Robust simplifications of multiscale biochemical networks

    Directory of Open Access Journals (Sweden)

    Zinovyev Andrei

    2008-10-01

    Full Text Available Abstract Background Cellular processes such as metabolism, decision making in development and differentiation, signalling, etc., can be modeled as large networks of biochemical reactions. In order to understand the functioning of these systems, there is a strong need for general model reduction techniques allowing to simplify models without loosing their main properties. In systems biology we also need to compare models or to couple them as parts of larger models. In these situations reduction to a common level of complexity is needed. Results We propose a systematic treatment of model reduction of multiscale biochemical networks. First, we consider linear kinetic models, which appear as "pseudo-monomolecular" subsystems of multiscale nonlinear reaction networks. For such linear models, we propose a reduction algorithm which is based on a generalized theory of the limiting step that we have developed in 1. Second, for non-linear systems we develop an algorithm based on dominant solutions of quasi-stationarity equations. For oscillating systems, quasi-stationarity and averaging are combined to eliminate time scales much faster and much slower than the period of the oscillations. In all cases, we obtain robust simplifications and also identify the critical parameters of the model. The methods are demonstrated for simple examples and for a more complex model of NF-κB pathway. Conclusion Our approach allows critical parameter identification and produces hierarchies of models. Hierarchical modeling is important in "middle-out" approaches when there is need to zoom in and out several levels of complexity. Critical parameter identification is an important issue in systems biology with potential applications to biological control and therapeutics. Our approach also deals naturally with the presence of multiple time scales, which is a general property of systems biology models.

  10. Biochemically enhanced methane production from coal

    Science.gov (United States)

    Opara, Aleksandra

    For many years, biogas was connected mostly with the organic matter decomposition in shallow sediments (e.g., wetlands, landfill gas, etc.). Recently, it has been realized that biogenic methane production is ongoing in many hydrocarbon reservoirs. This research examined microbial methane and carbon dioxide generation from coal. As original contributions methane production from various coal materials was examined in classical and electro-biochemical bench-scale reactors using unique, developed facultative microbial consortia that generate methane under anaerobic conditions. Facultative methanogenic populations are important as all known methanogens are strict anaerobes and their application outside laboratory would be problematic. Additional testing examined the influence of environmental conditions, such as pH, salinity, and nutrient amendments on methane and carbon dioxide generation. In 44-day ex-situ bench-scale batch bioreactor tests, up to 300,000 and 250,000 ppm methane was generated from bituminous coal and bituminous coal waste respectively, a significant improvement over 20-40 ppm methane generated from control samples. Chemical degradation of complex hydrocarbons using environmentally benign reagents, prior to microbial biodegradation and methanogenesis, resulted in dissolution of up to 5% bituminous coal and bituminous coal waste and up to 25% lignite in samples tested. Research results confirm that coal waste may be a significant underutilized resource that could be converted to useful fuel. Rapid acidification of lignite samples resulted in low pH (below 4.0), regardless of chemical pretreatment applied, and did not generate significant methane amounts. These results confirmed the importance of monitoring and adjusting in situ and ex situ environmental conditions during methane production. A patented Electro-Biochemical Reactor technology was used to supply electrons and electron acceptor environments, but appeared to influence methane generation in a

  11. Biochemical Pharmacology of the Sigma-1 Receptor.

    Science.gov (United States)

    Chu, Uyen B; Ruoho, Arnold E

    2016-01-01

    The sigma-1 receptor (S1R) is a 223 amino acid two transmembrane (TM) pass protein. It is a non-ATP-binding nonglycosylated ligand-regulated molecular chaperone of unknown three-dimensional structure. The S1R is resident to eukaryotic mitochondrial-associated endoplasmic reticulum and plasma membranes with broad functions that regulate cellular calcium homeostasis and reduce oxidative stress. Several multitasking functions of the S1R are underwritten by chaperone-mediated direct (and indirect) interactions with ion channels, G-protein coupled receptors and cell-signaling molecules involved in the regulation of cell growth. The S1R is a promising drug target for the treatment of several neurodegenerative diseases related to cellular stress. In vitro and in vivo functional and molecular characteristics of the S1R and its interactions with endogenous and synthetic small molecules have been discovered by the use of pharmacologic, biochemical, biophysical, and molecular biology approaches. The S1R exists in monomer, dimer, tetramer, hexamer/octamer, and higher oligomeric forms that may be important determinants in defining the pharmacology and mechanism(s) of action of the S1R. A canonical GXXXG in putative TM2 is important for S1R oligomerization. The ligand-binding regions of S1R have been identified and include portions of TM2 and the TM proximal regions of the C terminus. Some client protein chaperone functions and interactions with the cochaperone 78-kDa glucose-regulated protein (binding immunoglobulin protein) involve the C terminus. Based on its biochemical features and mechanisms of chaperone action the possibility that the S1R is a member of the small heat shock protein family is discussed. PMID:26560551

  12. Correlation between the genotoxicity endpoints measured by two different genotoxicity assays: comet assay and CBMN assay

    OpenAIRE

    Carina Ladeira; Susana Viegas; Gomes, Manuel C.

    2015-01-01

    The cytokinesis-block micronucleus cytome (CBMN) assay is a comprehensive system for measuring DNA damage; cytostasis and cytotoxicity-DNA damage events are scored specifically in once-divided binucleated cells. The endpoints possible to be measured are micronuclei (MN), a biomarker of chromosome breakage and/or whole chromosome loss, nucleoplasmic bridges (NPB), a biomarker of DNA misrepair and/or telomere end-fusions, and nuclear buds (NBUD), a biomarker of elimination of amplified DNA and/...

  13. Glucuronoyl Esterase Screening and Characterization Assays Utilizing Commercially Available Benzyl Glucuronic Acid Ester

    Directory of Open Access Journals (Sweden)

    Hampus Sunner

    2015-09-01

    Full Text Available Research on glucuronoyl esterases (GEs has been hampered by the lack of enzyme assays based on easily obtainable substrates. While benzyl d-glucuronic acid ester (BnGlcA is a commercially available substrate that can be used for GE assays, several considerations regarding substrate instability, limited solubility and low apparent affinities should be made. In this work we discuss the factors that are important when using BnGlcA for assaying GE activity and show how these can be applied when designing BnGlcA-based GE assays for different applications: a thin-layer chromatography assay for qualitative activity detection, a coupled-enzyme spectrophotometric assay that can be used for high-throughput screening or general activity determinations and a HPLC-based detection method allowing kinetic determinations. The three-level experimental procedure not merely facilitates routine, fast and simple biochemical characterizations but it can also give rise to the discovery of different GEs through an extensive screening of heterologous Genomic and Metagenomic expression libraries.

  14. Radiosotopic assay and binder therefor

    International Nuclear Information System (INIS)

    A rapid and less costly radioisotopic assay for measuring the concentration of folate in blood serum is described. This procedure utilizes 3H-pteroylmonoglutamate, unlabeled 5-methyltetrahydrofolic acid, and a partially purified folate binder, such as for example a folate binder extracted from hog kidney. The procedure involves radioisotopically relating the bound amounts of a labeled folate and a known folate at various concentrations of the known folate in a system containing a predetermined amount of the labeled folate, a predetermined amount of the binder factor for the folates, and a predetermined amount of defolated test serum. 16 claims, 8 drawing figures

  15. Redox-Reaction Based Spectrophotometric Assay of Isoniazid in Pharmaceuticals

    OpenAIRE

    N Swamy; K. N. Prashanth; K. Basavaiah

    2014-01-01

    Two spectrophotometric methods are described for the determination of isoniazid (INH) in pharmaceuticals. In the first method (FCR method), INH is reacted with Folin-Ciocalteu reagent in Na2CO3 medium and the resulting blue colored chromogen measured at 760 nm. Iron(II), formed as a result of reaction between INH and iron(III), is made to react with ferricyanide, and the resulting Prussian blue is measured at 760 nm, basing the second method (FFC method). The conditions for better performance...

  16. The chemistry behind antioxidant capacity assays.

    Science.gov (United States)

    Huang, Dejian; Ou, Boxin; Prior, Ronald L

    2005-03-23

    This review summarizes the multifaceted aspects of antioxidants and the basic kinetic models of inhibited autoxidation and analyzes the chemical principles of antioxidant capacity assays. Depending upon the reactions involved, these assays can roughly be classified into two types: assays based on hydrogen atom transfer (HAT) reactions and assays based on electron transfer (ET). The majority of HAT-based assays apply a competitive reaction scheme, in which antioxidant and substrate compete for thermally generated peroxyl radicals through the decomposition of azo compounds. These assays include inhibition of induced low-density lipoprotein autoxidation, oxygen radical absorbance capacity (ORAC), total radical trapping antioxidant parameter (TRAP), and crocin bleaching assays. ET-based assays measure the capacity of an antioxidant in the reduction of an oxidant, which changes color when reduced. The degree of color change is correlated with the sample's antioxidant concentrations. ET-based assays include the total phenols assay by Folin-Ciocalteu reagent (FCR), Trolox equivalence antioxidant capacity (TEAC), ferric ion reducing antioxidant power (FRAP), "total antioxidant potential" assay using a Cu(II) complex as an oxidant, and DPPH. In addition, other assays intended to measure a sample's scavenging capacity of biologically relevant oxidants such as singlet oxygen, superoxide anion, peroxynitrite, and hydroxyl radical are also summarized. On the basis of this analysis, it is suggested that the total phenols assay by FCR be used to quantify an antioxidant's reducing capacity and the ORAC assay to quantify peroxyl radical scavenging capacity. To comprehensively study different aspects of antioxidants, validated and specific assays are needed in addition to these two commonly accepted assays. PMID:15769103

  17. Indirect conductimetric assay of antibacterial activities.

    Science.gov (United States)

    Sawai, J; Doi, R; Maekawa, Y; Yoshikawa, T; Kojima, H

    2002-11-01

    The applicability of indirect conductimetric assays for evaluation of antibacterial activity was examined. The minimal inhibitory concentration (MIC) obtained by the indirect method was consistent with that by the direct conductimetric assay and the turbidity method. The indirect assay allows use of growth media, which cannot be used in the direct conductimetric assay, making it possible to evaluate the antibacterial activity of insoluble or slightly soluble materials with high turbidity, such as antibacterial ceramic powders. PMID:12407467

  18. Local biochemical and morphological differences in human Achilles tendinopathy

    DEFF Research Database (Denmark)

    J, Pingel; Fredberg, Ulrich; K, Qvortrup;

    2012-01-01

    The incidence of Achilles tendinopathy is high and underlying etiology as well as biochemical and morphological pathology associated with the disease is largely unknown. The aim of the present study was to describe biochemical and morphological differences in chronic Achilles tendinopathy. The...

  19. Serum indices: managing assay interference.

    Science.gov (United States)

    Farrell, Christopher-John L; Carter, Andrew C

    2016-09-01

    Clinical laboratories frequently encounter samples showing significant haemolysis, icterus or lipaemia. Technical advances, utilizing spectrophotometric measurements on automated chemistry analysers, allow rapid and accurate identification of such samples. However, accurate quantification of haemolysis, icterus and lipaemia interference is of limited value if laboratories do not set rational alert limits, based on sound interference testing experiments. Furthermore, in the context of increasing consolidation of laboratories and the formation of laboratory networks, there is an increasing requirement for harmonization of the handling of haemolysis, icterus and lipaemia-affected samples across different analytical platforms. Harmonization may be best achieved by considering both the analytical aspects of index measurement and the possible variations in the effects of haemolysis, icterus and lipaemia interferences on assays from different manufacturers. Initial verification studies, followed up with ongoing quality control testing, can help a laboratory ensure the accuracy of haemolysis, icterus and lipaemia index results, as well as assist in managing any biases in index results from analysers from different manufacturers. Similarities, and variations, in the effect of haemolysis, icterus and lipaemia interference in assays from different manufacturers can often be predicted from the mechanism of interference. Nevertheless, interference testing is required to confirm expected similarities or to quantify differences. It is important that laboratories are familiar with a number of interference testing protocols and the particular strengths and weaknesses of each. A rigorous approach to all aspects of haemolysis, icterus and lipaemia interference testing allows the analytical progress in index measurement to be translated into improved patient care. PMID:27147624

  20. SNO+ Scintillator Purification and Assay

    International Nuclear Information System (INIS)

    We describe the R and D on the scintillator purification and assay methods and technology for the SNO+ neutrino and double-beta decay experiment. The SNO+ experiment is a replacement of the SNO heavy water with liquid scintillator comprised of 2 g/L PPO in linear alkylbenzene (LAB). During filling the LAB will be transported underground by rail car and purified by multi-stage distillation and steam stripping at a flow rate of 19 LPM. While the detector is operational the scintillator can be recirculated at 150 LPM (full detector volume in 4 days) to provide repurification as necessary by either water extraction (for Ra, K, Bi) or by functional metal scavenger columns (for Pb, Ra, Bi, Ac, Th) followed by steam stripping to remove noble gases and oxygen (Rn, O2, Kr, Ar). The metal scavenger columns also provide a method for scintillator assay for ex-situ measurement of the U and Th chain radioactivity. We have developed ''natural'' radioactive spikes of Pb and Ra in LAB and use these for purification testing. Lastly, we present the planned operating modes and purification strategies and the plant specifications and design.

  1. Proteasome Assay in Cell Lysates

    Science.gov (United States)

    Maher, Pamela

    2016-01-01

    The ubiquitin-proteasome system (UPS) mediates the majority of the proteolysis seen in the cytoplasm and nucleus of mammalian cells. As such it plays an important role in the regulation of a variety of physiological and pathophysiological processes including tumorigenesis, inflammation and cell death (Ciechanover, 2005; Kisselev and Goldberg, 2001). A number of recent studies have shown that proteasome activity is decreased in a variety of neurological disorders including Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis and stroke as well as during normal aging (Chung et al., 2001; Ciechanover and Brundin, 2003; Betarbet et al., 2005). This decrease in proteasome activity is thought to play a critical role in the accumulation of abnormal and oxidized proteins. Protein clearance by the UPS involves two sequential reactions. The first is the tagging of protein lysine residues with ubiquitin (Ub) and the second is the subsequent degradation of the tagged proteins by the proteasome. We herein describe an assay for the second of these two reactions (Valera et al., 2013). This assay uses fluorogenic substrates for each of the three activities of the proteasome: chymotrypsin-like activity, trypsin-like activity and caspase-like activity. Cleavage of the fluorophore from the substrate by the proteasome results in fluorescence that can be detected with a fluorescent plate reader.

  2. SNO+ Scintillator Purification and Assay

    Science.gov (United States)

    Ford, R.; Chen, M.; Chkvorets, O.; Hallman, D.; Vázquez-Jáuregui, E.

    2011-04-01

    We describe the R&D on the scintillator purification and assay methods and technology for the SNO+ neutrino and double-beta decay experiment. The SNO+ experiment is a replacement of the SNO heavy water with liquid scintillator comprised of 2 g/L PPO in linear alkylbenzene (LAB). During filling the LAB will be transported underground by rail car and purified by multi-stage distillation and steam stripping at a flow rate of 19 LPM. While the detector is operational the scintillator can be recirculated at 150 LPM (full detector volume in 4 days) to provide repurification as necessary by either water extraction (for Ra, K, Bi) or by functional metal scavenger columns (for Pb, Ra, Bi, Ac, Th) followed by steam stripping to remove noble gases and oxygen (Rn, O2, Kr, Ar). The metal scavenger columns also provide a method for scintillator assay for ex-situ measurement of the U and Th chain radioactivity. We have developed "natural" radioactive spikes of Pb and Ra in LAB and use these for purification testing. Lastly, we present the planned operating modes and purification strategies and the plant specifications and design.

  3. 21 CFR 864.7525 - Heparin assay.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Heparin assay. 864.7525 Section 864.7525 Food and... HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7525 Heparin assay. (a) Identification. A heparin assay is a device used to determine the level of the anticoagulant heparin in the...

  4. 21 CFR 864.7490 - Sulfhemoglobin assay.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Sulfhemoglobin assay. 864.7490 Section 864.7490 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... assay. (a) Identification. A sulfhemoglobin assay is a device consisting of the reagents,...

  5. 21 CFR 864.7250 - Erythropoietin assay.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Erythropoietin assay. 864.7250 Section 864.7250... assay. (a) Identification. A erythropoietin assay is a device that measures the concentration of erythropoietin (an enzyme that regulates the production of red blood cells) in serum or urine. This...

  6. 21 CFR 864.7425 - Carboxyhemoglobin assay.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carboxyhemoglobin assay. 864.7425 Section 864.7425 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... assay. (a) Identification. A carboxyhemoglobin assay is a device used to determine the...

  7. 21 CFR 866.3210 - Endotoxin assay.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Endotoxin assay. 866.3210 Section 866.3210 Food... DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3210 Endotoxin assay. (a) Identification. An endotoxin assay is a device that uses serological techniques in whole blood. The device...

  8. Multicentre comparison of a diagnostic assay

    DEFF Research Database (Denmark)

    Waters, Patrick; Reindl, Markus; Saiz, Albert;

    2016-01-01

    ) assays in neuromyelitis optica spectrum disorders (NMOSD). METHODS: Coded samples from patients with neuromyelitis optica (NMO) or NMOSD (101) and controls (92) were tested at 15 European diagnostic centres using 21 assays including live (n=3) or fixed cell-based assays (n=10), flow cytometry (n=4...

  9. Model-Based Design of Biochemical Microreactors.

    Science.gov (United States)

    Elbinger, Tobias; Gahn, Markus; Neuss-Radu, Maria; Hante, Falk M; Voll, Lars M; Leugering, Günter; Knabner, Peter

    2016-01-01

    Mathematical modeling of biochemical pathways is an important resource in Synthetic Biology, as the predictive power of simulating synthetic pathways represents an important step in the design of synthetic metabolons. In this paper, we are concerned with the mathematical modeling, simulation, and optimization of metabolic processes in biochemical microreactors able to carry out enzymatic reactions and to exchange metabolites with their surrounding medium. The results of the reported modeling approach are incorporated in the design of the first microreactor prototypes that are under construction. These microreactors consist of compartments separated by membranes carrying specific transporters for the input of substrates and export of products. Inside the compartments of the reactor multienzyme complexes assembled on nano-beads by peptide adapters are used to carry out metabolic reactions. The spatially resolved mathematical model describing the ongoing processes consists of a system of diffusion equations together with boundary and initial conditions. The boundary conditions model the exchange of metabolites with the neighboring compartments and the reactions at the surface of the nano-beads carrying the multienzyme complexes. Efficient and accurate approaches for numerical simulation of the mathematical model and for optimal design of the microreactor are developed. As a proof-of-concept scenario, a synthetic pathway for the conversion of sucrose to glucose-6-phosphate (G6P) was chosen. In this context, the mathematical model is employed to compute the spatio-temporal distributions of the metabolite concentrations, as well as application relevant quantities like the outflow rate of G6P. These computations are performed for different scenarios, where the number of beads as well as their loading capacity are varied. The computed metabolite distributions show spatial patterns, which differ for different experimental arrangements. Furthermore, the total output of G6P

  10. Definitions of biochemical failure in prostate cancer following radiation therapy

    International Nuclear Information System (INIS)

    Purpose: The American Society for Therapeutic Radiology and Oncology (ASTRO) published a consensus panel definition of biochemical failure following radiation therapy for prostate cancer. In this paper, we develop a series of alternative definitions of biochemical failure. Using data from 688 patients, we evaluated the sensitivity and specificity of the various definitions, with respect to a defined 'clinically meaningful' outcome. Methods and Materials: The ASTRO definition of biochemical failure requires 3 consecutive rises in prostate-specific antigen (PSA). We considered several modifications to the standard definition: to require PSA rises of a certain magnitude, to consider 2 instead of 3 rises, to require the final PSA value to be greater than a fixed cutoff level, and to define biochemical failure based on the slope of PSA over 1, 1.5, or 2 years. A clinically meaningful failure is defined as local recurrence, distant metastases, initiation of unplanned hormonal therapy, unplanned radical prostatectomy, or a PSA>25 later than 6 months after radiation. Results: Requiring the final PSA in a series of consecutive rises to be larger than 1.5 ng/mL increased the specificity of biochemical failure. For a fixed specificity, defining biochemical failure based on 2 consecutive rises, or the slope over the last year, could increase the sensitivity by up to approximately 20%, compared to the ASTRO definition. Using a rule based on the slope over the previous year or 2 rises leads to a slightly earlier detection of biochemical failure than does the ASTRO definition. Even with the best rule, only approximately 20% of true failures are biochemically detected more than 1 year before the clinically meaningful event time. Conclusion: There is potential for improvement in the ASTRO consensus definition of biochemical failure. Further research is needed, in studies with long follow-up times, to evaluate the relationship between various definitions of biochemical failure and

  11. The Antioxidant Activity and the Effects of Convolvulus Aucheri (Convolvulaceae Extract on Biochemical Indices in Rats

    Directory of Open Access Journals (Sweden)

    R. MAMMADOV

    2014-06-01

    Full Text Available Convolvulus L., the second largest genus of the family Convolvulaceae, has about 250 species distributed mainly in the temperate and tropical regions of the world, with a cosmopolitan distribution. According to recent studies, this genus is represented in Turkey by 33 species, 9 of which are endemic. Convolvulus species are extensively used in traditional medicine for various purposes as in ulcer treatment, diabetes, and tension. The aim of this study was to investigate the antioxidant activity and the effects of Convolvulus aucheri extract on biochemical indices in rats.The antioxidant activities of various solvent extracts (methanol, ethanol, acetone and benzene obtained from C. aucheri were evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH and β-carotene-linoleic acid assays. In addition, total phenolic contents in all the extracts of C. aucheri were determined as gallic acid equivalents. As for the biochemical assay, the extracts of the plant at the concentrations of 0.5 and 1 ml/100 g body weight/day were administered orally to the experimental groups for 36 days. Blood samples were taken by cardiac venipuncture on the 2nd and 4th weeks after the initial treatment. Aspartate aminotransferase (AST, alanine aminotransferase (ALT, gamma-glutamyltransferase (GGT and blood urea nitrogen (BUN were measured for the determination of liver function.Among all the extracts, the ethanolic extracts of C. aucheri showed the highest antioxidant activity (66.88 ± 0.8%. The highest free radical scavenging activity (59.50 ± 1.2% was recorded on the ethanolic extracts. The phenolic contents of the ethanolic extracts are higher than the other types of extracts (23.03 mg/g GAE. In biochemical assay, it was found a significant increase in the levels of serum ALT, AST and decrease the serum GGT levels in the experimental groups when compared to the controls (p<0.05. On the other hand, we found significant increase in the level of BUN.

  12. Establishment of Immunoradiometric Assay for Carcinoembryonic Antigen

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Two anti-CEA monoclonal antibodies are used, one is coated on the microtiter plate, the other is labeled to make 125I-CEAMcAb. The one-step assay is established based on immunoradiometric assay(IRMA). The sensitivity of the assay is 0.5 μ g/L. The intra-assay CVs and the inter-assay CVs are lower than 10.0% and 15.0%, respectively. The analytical recoveries are ranged from 97.4% to 107.8%. The reference cut-out value of 35 normal serum is lower than

  13. Making transuranic assay measurements using modern controllers

    International Nuclear Information System (INIS)

    This paper describes methodology and computer-controlled instrumentation developed at the Los Alamos National Laboratory that accurately performs nondestructive assays of large containers bearing transuranic wastes and nonradioactive matrix materials. These assay systems can measure fissile isotopes with 1-mg sensitivity and spontaneous neutron-emitting isotopes at a 10-mg sensitivity. The assays are performed by neutron interrogation, detection, and counting in a custom assay chamber. An International Business Machines Personal Computer (IBM-PC) is used to control the CAMAC-based instrumentation system that acquires the assay data. 6 refs., 7 figs

  14. BALL - biochemical algorithms library 1.3

    Directory of Open Access Journals (Sweden)

    Stöckel Daniel

    2010-10-01

    Full Text Available Abstract Background The Biochemical Algorithms Library (BALL is a comprehensive rapid application development framework for structural bioinformatics. It provides an extensive C++ class library of data structures and algorithms for molecular modeling and structural bioinformatics. Using BALL as a programming toolbox does not only allow to greatly reduce application development times but also helps in ensuring stability and correctness by avoiding the error-prone reimplementation of complex algorithms and replacing them with calls into the library that has been well-tested by a large number of developers. In the ten years since its original publication, BALL has seen a substantial increase in functionality and numerous other improvements. Results Here, we discuss BALL's current functionality and highlight the key additions and improvements: support for additional file formats, molecular edit-functionality, new molecular mechanics force fields, novel energy minimization techniques, docking algorithms, and support for cheminformatics. Conclusions BALL is available for all major operating systems, including Linux, Windows, and MacOS X. It is available free of charge under the Lesser GNU Public License (LPGL. Parts of the code are distributed under the GNU Public License (GPL. BALL is available as source code and binary packages from the project web site at http://www.ball-project.org. Recently, it has been accepted into the debian project; integration into further distributions is currently pursued.

  15. PHA bioplastics, biochemicals, and energy from crops.

    Science.gov (United States)

    Somleva, Maria N; Peoples, Oliver P; Snell, Kristi D

    2013-02-01

    Large scale production of polyhydroxyalkanoates (PHAs) in plants can provide a sustainable supply of bioplastics, biochemicals, and energy from sunlight and atmospheric CO(2). PHAs are a class of polymers with various chain lengths that are naturally produced by some microorganisms as storage materials. The properties of these polyesters make them functionally equivalent to many of the petroleum-based plastics that are currently in the market place. However, unlike most petroleum-derived plastics, PHAs can be produced from renewable feedstocks and easily degrade in most biologically active environments. This review highlights research efforts over the last 20 years to engineer the production of PHAs in plants with a focus on polyhydroxybutryrate (PHB) production in bioenergy crops with C(4) photosynthesis. PHB has the potential to be a high volume commercial product with uses not only in the plastics and materials markets, but also in renewable chemicals and feed. The major challenges of improving product yield and plant fitness in high biomass yielding C(4) crops are discussed in detail. PMID:23294864

  16. NUTRITION AND SPORTS: A BIOCHEMICAL APPROACH

    Directory of Open Access Journals (Sweden)

    A.A.G. Bianco

    2004-05-01

    Full Text Available This work presents a course dedicated to the pedagogical instruction of graduate students (Ensino deBioqumica - QBQ 5711 in which they have to plan and teach a 30 hour-discipline for undergraduatestudents. The graduate students have to choose a subject for the discipline and, in 2003, the cho-sen subject was Nutrition and Sports: a Biochemical Approach, which is not specically broached inregular disciplines. The discipline was structured in the basis of collaborative learning, thus, the 75 en-rolled undergraduate students (from dierent courses as Nutrition, Sports, Pharmacy, Chemistry andBiology were organized in small working groups. The students were given a study guide produced bythe graduate teachers (available in Portuguese at http://www.sbbq.org.br/revista/mtdidaticos.php,in which the following contents were covered: muscle contraction, O2 up-take, oxidative stress andanti-oxidant response, cramp, hydration, doping and nutritional supplies. In the nal activity thestudents had to evaluate critically myths and true facts in 80 statements usually associated to physi-cal activities and sports. The discipline was evaluated through questionnaires. From the analysis ofthe answers of both undergraduate and graduate/teachers students it is possible to conclude that thediscipline was well conduced and succeeded. These results emphasize the relevance and contribution ofthis kind of discipline to the pedagogical instruction of the graduate students and also to the increaseof undergraduate students interests in Biochemistry.

  17. Biochemical and proteomic characterization of alkaptonuric chondrocytes.

    Science.gov (United States)

    Braconi, Daniela; Bernardini, Giulia; Bianchini, Claretta; Laschi, Marcella; Millucci, Lia; Amato, Loredana; Tinti, Laura; Serchi, Tommaso; Chellini, Federico; Spreafico, Adriano; Santucci, Annalisa

    2012-09-01

    Alkaptonuria (AKU) is a rare genetic disease associated with the accumulation of homogentisic acid (HGA) and its oxidized/polymerized products which leads to the deposition of melanin-like pigments (ochronosis) in connective tissues. Although numerous case reports have described ochronosis in joints, little is known on the molecular mechanisms leading to such a phenomenon. For this reason, we characterized biochemically chondrocytes isolated from the ochronotic cartilage of AKU patients. Based on the macroscopic appearance of the ochronotic cartilage, two sub-populations were identified: cells coming from the black portion of the cartilage were referred to as "black" AKU chondrocytes, while those coming from the white portion were referred to as "white" AKU chondrocytes. Notably, both AKU chondrocytic types were characterized by increased apoptosis, NO release, and levels of pro-inflammatory cytokines. Transmission electron microscopy also revealed that intracellular ochronotic pigment deposition was common to both "white" and "black" AKU cells. We then undertook a proteomic and redox-proteomic analysis of AKU chondrocytes which revealed profound alterations in the levels of proteins involved in cell defence, protein folding, and cell organization. An increased post-translational oxidation of proteins, which also involved high molecular weight protein aggregates, was found to be particularly relevant in "black" AKU chondrocytes. PMID:22213341

  18. Skin biochemical composition analysis by Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Patricia Karen; Tosato, Maira Gaspar; Alves, Rani de Souza; Martin, Airton Abrahao; Favero, Priscila Pereira; Raniero, Leandro, E-mail: amartin@univap.br [Laboratorio de Espectroscopia Vibracional Biomedica, Instituto de Pesquisa e Desenvolvimento - IP e D, Universidade do Vale do Paraiba - UniVap, Sao Jose dos Campos, SP (Brazil)

    2012-09-15

    Skin aging is characterized by cellular and molecular alterations. In this context, Confocal Raman spectroscopy was used in vivo to measure these biochemical changes as function of the skin depth. In this study we have tried to correlate spectra from pure amino acids to in vivo spectra from volunteers with different ages. This study was performed on 32 volunteers: 11 from Group A (20-23 years), 11 from Group B (39-42 years) and 10 from Group C (59-62 years). For each group, the Raman spectra were measured on the surface (0 mm), 30 +- 3 mm and 60 +- 3 {mu}m below the surface. The results from intergroup comparisons showed that the oldest group had a prevalence of the tyrosine band, but it also presented a decrease in the band centered at 875 cm{sup -1} of pyrrolidone acid. The amide I band centered at 1637 cm{sup -1} that is attributed to collagen, as well as other proteins and lipid, showed a smaller amount of these biomolecules for Group C, which can be explained by the decrease in collagen concentration as a function of age. (author)

  19. Activity assay of membrane transport proteins

    Institute of Scientific and Technical Information of China (English)

    Hao Xie

    2008-01-01

    Membrane transport proteins are integral membrane proteins and considered as potential drug targets. Activity assay of transport proteins is essential for developing drugs to target these proteins. Major issues related to activity assessment of transport proteins include availability of transporters,transport activity of transporters, and interactions between ligands and transporters. Researchers need to consider the physiological status of proteins (bound in lipid membranes or purified), availability and specificity of substrates, and the purpose of the activity assay (screening, identifying, or comparing substrates and inhibitors) before choosing appropriate assay strategies and techniques. Transport proteins bound in vesicular membranes can be assayed for transporting substrate across membranes by means of uptake assay or entrance counterflow assay. Alternatively, transport proteins can be assayed for interactions with ligands by using techniques such as isothermal titration calorimetry, nuclear magnetic resonance spectroscopy, or surface plasmon resonance. Other methods and techniques such as fluorometry, scintillation proximity assay, electrophysiological assay, or stopped-flow assay could also be used for activity assay of transport proteins. In this paper the major strategies and techniques for activity assessment of membrane transport proteins are reviewed.

  20. Non destructive assay (NDA) techniques

    International Nuclear Information System (INIS)

    In the IAEA Safeguards System the basic verification method used is nuclear material accountancy, with containment and surveillance as important complementary measures. If nuclear material accountancy is to be effective, IAEA inspectors have to make independent measurements to verify declared material quantities. Most of the equipment available to the inspectors is designed to measure gamma rays and/or neutrons emitted by various nuclear materials. Equipment is also available to measure the gross weight of an item containing nuclear material. These types of measurement techniques are generally grouped under the title of nondestructive assay (NDA). The paper describes the NDA techniques and instruments used to verify the total amount of nuclear material held at a nuclear facility. (author)

  1. Effects of organic solvents on the enzyme activity of Trypanosoma cruzi glyceraldehyde-3-phosphate dehydrogenase in calorimetric assays

    DEFF Research Database (Denmark)

    Wiggers, Henrik; Cheleski, J; Zottis, A;

    2007-01-01

    In drug discovery programs, dimethyl sulfoxide (DMSO) is a standard solvent widely used in biochemical assays. Despite the extensive use and study of enzymes in the presence of organic solvents, for some enzymes the effect of organic solvent is unknown. Macromolecular targets may be affected by the...... presence of different solvents in such a way that conformational changes perturb their active site structure accompanied by dramatic variations in activity when performing biochemical screenings. To address this issue, in this work we studied the effects of two organic solvents, DMSO and methanol (Me...... up to 5.0% for MeOH and up to 7.5% for DMSO. The results show that when GAPDH is assayed in the presence of DMSO (5%, v/v) using the ITC experiment, the enzyme exhibits approximately twofold higher activity than that of GAPDH with no cosolvent added. When MeOH (5%, v/v) is the cosolvent, the GAPDH...

  2. Predictive Assay For Cancer Targets

    Energy Technology Data Exchange (ETDEWEB)

    Suess, A; Nguyen, C; Sorensen, K; Montgomery, J; Souza, B; Kulp, K; Dugan, L; Christian, A

    2005-09-19

    Early detection of cancer is a key element in successful treatment of the disease. Understanding the particular type of cancer involved, its origins and probable course, is also important. PhIP (2-amino-1-methyl-6 phenylimidazo [4,5-b]pyridine), a heterocyclic amine produced during the cooking of meat at elevated temperatures, has been shown to induce mammary cancer in female, Sprague-Dawley rats. Tumors induced by PhIP have been shown to contain discreet cytogenetic signature patterns of gains and losses using comparative genomic hybridization (CGH). To determine if a protein signature exists for these tumors, we are analyzing expression levels of the protein products of the above-mentioned tumors in combination with a new bulk protein subtractive assay. This assay produces a panel of antibodies against proteins that are either on or off in the tumor. Hybridization of the antibody panel onto a 2-D gel of tumor or control protein will allow for identification of a distinct protein signature in the tumor. Analysis of several gene databases has identified a number of rat homologs of human cancer genes located in these regions of gain and loss. These genes include the oncogenes c-MYK, ERBB2/NEU, THRA and tumor suppressor genes EGR1 and HDAC3. The listed genes have been shown to be estrogen-responsive, suggesting a possible link between delivery of bio-activated PhIP to the cell nucleus via estrogen receptors and gene-specific PhIP-induced DNA damage, leading to cell transformation. All three tumors showed similar silver staining patterns compared to each other, while they all were different than the control tissue. Subsequent screening of these genes against those from tumors know to be caused by other agents may produce a protein signature unique to PhIP, which can be used as a diagnostic to augment optical and radiation-based detection schemes.

  3. Development and application of an assay for uranyl complexation by fungal metabolites, including siderophores.

    Science.gov (United States)

    Renshaw, Joanna C; Halliday, Verity; Robson, Geoffrey D; Trinci, Anthony P J; Wiebe, Marilyn G; Livens, Francis R; Collison, David; Taylor, Robin J

    2003-06-01

    An assay to detect UO(2)(2+) complexation was developed based on the chrome azurol S (CAS) assay for siderophores (B. Schwyn and J. B. Neilands, Anal. Biochem. 160:47-56, 1987) and was used to investigate the ability of fungal metabolites to complex actinides. In this assay the discoloration of two dyed agars (one containing a CAS-Fe(3+) dye and the other containing a CAS-UO(2)(2+) dye) caused by ligands was quantified. The assay was tested by using the siderophore desferrioxamine B (DFO), and the results showed that there was a regular, reproducible relationship between discoloration and the amount of siderophore added. The ratio of the discoloration on the CAS-UO(2)(2+) agar to the discoloration on the CAS-Fe(3+) agar was independent of the amount of siderophore added. A total of 113 fungi and yeasts were isolated from three soil samples taken from the Peak District National Park. The fungi were screened for the production of UO(2)(2+) chelators by using the CAS-based assay and were also tested specifically for hydroxamate siderophore production by using the hydroxamate siderophore auxotroph Aureobacterium flavescens JG-9. This organism is highly sensitive to the presence of hydroxamate siderophores. However, the CAS-based assay was found to be less sensitive than the A. flavescens JG-9 assay. No significant difference between the results for each site for the two tests was found. Three isolates were selected for further study and were identified as two Pencillium species and a Mucor species. Our results show that the new assay can be effectively used to screen fungi for the production of UO(2)(2+) chelating ligands. We suggest that hydroxamate siderophores can be produced by mucoraceous fungi. PMID:12788768

  4. Comet assay as a predictive assay for radiosensitivity of two human brain tumor cell lines

    International Nuclear Information System (INIS)

    Micronucleus assay and comet assay were compared as a predictive assay for radiosensitivity of tumors. Two human brain tumor cell lines, Becker (derived from astrocytoma) and ONS76 (derived from medulloblastoma) were used. Colony methods as the gold standard showed ONS76 as radiosensitive and Becker as radioresistant cell lines. Micronucleus assay revealed no different radiosensitivity between them. With comet assay, Becker cells received irradiation showed less damage to the DNA and faster repair of the damage than ONS76 cells did. The results correlate with those from colony methods. Comet assay is simple and rapid method for clinical use and it has an advantage not to establish the primary culture. Moreover, the results of comet assay showed not only DNA damage but also repair from the damage. It is concluded that comet assay is a superior method than micronucleus assay and has a potent candidate for clinical predictive assay. (author)

  5. A Complete Optical Sensor System Based on a POF-SPR Platform and a Thermo-Stabilized Flow Cell for Biochemical Applications.

    Science.gov (United States)

    Cennamo, Nunzio; Chiavaioli, Francesco; Trono, Cosimo; Tombelli, Sara; Giannetti, Ambra; Baldini, Francesco; Zeni, Luigi

    2016-01-01

    An optical sensor platform based on surface plasmon resonance (SPR) in a plastic optical fiber (POF) integrated into a thermo-stabilized flow cell for biochemical sensing applications is proposed. This device has been realized and experimentally tested by using a classic receptor-analyte assay. For this purpose, the gold surface of the POF was chemically modified through the formation of a self-assembling monolayer. The surface robustness of the POF-SPR platform has been tested for the first time thanks to the flow cell. The experimental results show that the proposed device can be successfully used for label-free biochemical sensing. The final goal of this work is to achieve a complete, small-size, simple to use and low cost optical sensor system. The whole system with the flow cell and the optical sensor are extensively described, together with the experimental results obtained with an immunoglobulin G (IgG)/anti-IgG assay. PMID:26861328

  6. Novel patient cell-based HTS assay for identification of small molecules for a lysosomal storage disease.

    Directory of Open Access Journals (Sweden)

    Haifeng Geng

    Full Text Available Small molecules have been identified as potential therapeutic agents for lysosomal storage diseases (LSDs, inherited metabolic disorders caused by defects in proteins that result in lysosome dysfunctional. Some small molecules function assisting the folding of mutant misfolded lysosomal enzymes that are otherwise degraded in ER-associated degradation. The ultimate result is the enhancement of the residual enzymatic activity of the deficient enzyme. Most of the high throughput screening (HTS assays developed to identify these molecules are single-target biochemical assays. Here we describe a cell-based assay using patient cell lines to identify small molecules that enhance the residual arylsulfatase A (ASA activity found in patients with metachromatic leukodystrophy (MLD, a progressive neurodegenerative LSD. In order to generate sufficient cell lines for a large scale HTS, primary cultured fibroblasts from MLD patients were transformed using SV40 large T antigen. These SV40 transformed (SV40t cells showed to conserve biochemical characteristics of the primary cells. Using a specific colorimetric substrate para-nitrocatechol sulfate (pNCS, detectable ASA residual activity were observed in primary and SV40t fibroblasts from a MLD patient (ASA-I179S cultured in multi-well plates. A robust fluorescence ASA assay was developed in high-density 1,536-well plates using the traditional colorimetric pNCS substrate, whose product (pNC acts as "plate fluorescence quencher" in white solid-bottom plates. The quantitative cell-based HTS assay for ASA generated strong statistical parameters when tested against a diverse small molecule collection. This cell-based assay approach can be used for several other LSDs and genetic disorders, especially those that rely on colorimetric substrates which traditionally present low sensitivity for assay-miniaturization. In addition, the quantitative cell-based HTS assay here developed using patient cells creates an

  7. Comparative Analysis of Cultural Isolation and Pcr Based Assay for Detection of Campylobacter Jejuni In Food and Faecal Samples

    OpenAIRE

    Singh, Harkanwaldeep; Rathore, R. S.; Singh, Satparkash; Cheema, Pawanjit Singh

    2011-01-01

    In the present study, the efficacy of polymerase chain reaction (PCR) based on mapA gene of C. jejuni was tested for detection of Campylobacter jejuni in naturally infected as well as spiked faecal and food samples of human and animal origin. Simultaneously, all the samples were subjected to the cultural isolation of organism and biochemical characterization. The positive samples resulted in the amplification of a DNA fragment of size ~589 bp in PCR assay whereas the absence of such amplicon ...

  8. Comparative analysis of cultural isolation and PCR based assay for detection of Campylobacter jejuni in food and faecal samples

    OpenAIRE

    Harkanwaldeep Singh; Rathore, R. S.; Satparkash Singh; Pawanjit Singh Cheema

    2011-01-01

    In the present study, the efficacy of polymerase chain reaction (PCR) based on mapA gene of C. jejuni was tested for detection of Campylobacter jejuni in naturally infected as well as spiked faecal and food samples of human and animal origin. Simultaneously, all the samples were subjected to the cultural isolation of organism and biochemical characterization. The positive samples resulted in the amplification of a DNA fragment of size ~589 bp in PCR assay whereas the absence of such amplicon ...

  9. Assays for the biochemical and ultrastructural measurement of selective and nonselective types of autophagy in the yeast Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Guimaraes, Rodrigo Soares; Delorme-Axford, Elizabeth; Klionsky, Daniel J; Reggiori, Fulvio

    2015-01-01

    Autophagy is a conserved intracellular catabolic pathway that degrades unnecessary or dysfunctional cellular components. Components destined for degradation are sequestered into double-membrane vesicles called autophagosomes, which subsequently fuse with the vacuole/lysosome delivering their cargo i

  10. First Evaluation of the Biologically Active Substances and Antioxidant Potential of Regrowth Velvet Antler by means of Multiple Biochemical Assays

    Directory of Open Access Journals (Sweden)

    Yujiao Tang

    2015-01-01

    Full Text Available We investigated the biologically active substances contained in RVA (regrowth velvet antler by comparing the composition of biologically active substances and antioxidant potential of different antler segments. RVA was subjected to extraction using DW (distilled water. RVA was divided into 3 segments: T-RVA (top RVA, M-RVA (middle RVA, and B-RVA (base RVA. The T-RVA section possessed the greatest amounts of uronic acid (36.251 mg/g, sulfated GAGs (sulfated glycosaminoglycans (555.76 mg/g, sialic acid (111.276 mg/g, uridine (0.957 mg/g, uracil (1.084 mg/g, and hypoxanthine (1.2631 mg/g. In addition, the T-RVA section possessed the strongest antioxidant capacity as determined by DPPH, H2O2 (hydrogen peroxide, hydroxyl, and ABTS (2,2′-azinobis-3-ethylbenzthiazoline-6-sulphonate radical scavenging activity as well as FRAP (ferric reducing antioxidant power and ORAC (oxygen radical absorbance capacity. The values of those were 53.44, 23.09, 34.12, 60.31, and 35.81 TE/μM at 1 mg/mL and 113.57 TE/μM at 20 μg/mL. These results indicate that the T-RVA section possesses the greatest amount of biologically active substances and highest antioxidant potential. This is the first report on the biologically active substances and antioxidant potential of RVA.

  11. 40 CFR 158.2080 - Experimental use permit data requirements-biochemical pesticides.

    Science.gov (United States)

    2010-07-01

    ... requirements-biochemical pesticides. 158.2080 Section 158.2080 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical Pesticides § 158.2080 Experimental use permit data requirements—biochemical pesticides. (a) Sections...

  12. Expert system for transuranic waste assay

    International Nuclear Information System (INIS)

    Transuranic wastes are generated at the Savannah River Site (SRS) as a result of routine production of nuclear materials. These wastes contain Pu-238 and Pu-239 and are placed into lined 55-gallon waste drums. The drums are placed on monitored storage pads pending shipment to the Waste Isolation Pilot Plant in New Mexico. A passive-active neutron (PAN) assay system is used to determine the mass of the radioactive material within the waste drums. Assay results are used to classify the wastes as either low-level or transuranic (TRU). During assays, the PAN assay system communicates with an IBM-AT computer. A Fortran computer program, called NEUT, controls and performs all data analyses. Unassisted, the NEUT program cannot adequately interpret assay results. To eliminate this limitation, an expert system shell was used to write a new algorithm, called the Transuranic Expert System (TRUX), to drive the NEUT program and add decision making capabilities for analysis of the assay results. The TRUX knowledge base was formulated by consulting with human experts in the field of neutron assay, by direct experimentation on the PAN assay system, and by observing operations on a daily basis. TRUX, with its improved ability to interpret assay results, has eliminated the need for close supervision by a human expert, allowing skilled technicians to operate the PAN assay system. 4 refs., 1 fig., 4 tabs

  13. An electron microscopic and biochemical study of the effects of cyclic 3', 5'- AMP, ergotamine or propanolol on the lysosomes of newborn rat hepatocytes

    OpenAIRE

    Kotoulas, Angeliki O.; Kotoulas, Othon B.; Kalamidas, Stefanos

    1991-01-01

    The effects of cyclic 3', 5'-AMP, ergotamine or propranolol on newborn rat liver were studied by using biochemical assays, electron microscopy and quantitative morphometry. Cyclic AMP enhanced the normal postnatal rise in the glycogen-hydrolysing activity of acid alpha 1,4 glucosidase but had no effect on the maltose-hydrolysing activity of the enzyme. The results suggest that these activities may be due to different enzymes. Propranolol prevented the postnatal...

  14. Harmonization of radiobiological assays: why and how?

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency has made available a technical manual for cytogenetic biodosimetry assays (dicentric chromosome aberration (DCA) and cytokinesis-block micronucleus (CBMN) assays) used for radiation dose assessment in radiation accidents. The International Standardization Organization, which develops standards and guidelines, also provides an avenue for laboratory accreditation, has developed guidelines and recommendations for performing cytogenetic biodosimetry assays. Harmonization of DCA and CBMN assays, has improved their accuracy. Double-blinded inter-laboratory comparison studies involving several networks have further validated DCA and CBMN assays and improved the confidence in their potential use for radiation dose assessment in mass casualties. This kind of international harmonization is lacking for pre-clinical radiobiology assays. The widely used pre-clinical assays that are relatively important to set stage for clinical trials include clonogenic assays, flow-cytometry assays, apoptotic assays, and tumor regression and growth delay assays. However, significant inter-laboratory variations occur with respect to data among laboratories. This raises concerns on the reliability and reproducibility of preclinical data that drives further development and translation. Lack of reproducibility may stem from a variety of factors such as poor scientist training, less than optimal experimental design, inadequate description of methodology, and impulse to publish only the positive data etc. Availability of technical manuals, standard operating procedures, accreditation avenues for laboratories performing such assays, inter-laboratory comparisons, and use of standardized protocols are necessary to enhance reliability and reproducibility. Thus, it is important that radiobiological assays are harmonized for laboratory protocols to ensure successful translation of pre-clinical research on radiation effect modulators to help design clinic trials with

  15. Biochemical and genetical analysis reveal a new clade of biovar 3 Dickeya spp. strains isolated from potato in Europe

    OpenAIRE

    Slawiak, M.; Beckhoven, van, J.R.C.M.; Speksnijder, A.G.C.L.; Czajkowski, R.L.; Grabe, G; Wolf,

    2009-01-01

    Sixty-five potato strains of the soft rot-causing plant pathogenic bacterium Dickeya spp., and two strains from hyacinth, were characterised using biochemical assays, REP-PCR genomic finger printing, 16S rDNA and dnaX sequence analysis. These methods were compared with nineteen strains representing six Dickeya species which included the type strains. A group of twenty-two potato strains isolated between 2005-2007 in the Netherlands, Poland, Finland and Israel were characterised as belonging t...

  16. A critical appraisal of the phene-plate biochemical fingerprinting system for epidemiological subtyping of Salmonella typhimurium

    DEFF Research Database (Denmark)

    On, S.L.W.; Baggesen, Dorte Lau

    The efficacy and reproducibility of the Phene-Plate (PhP) system (Biosys Inova, Stockholm, Sweden) for biochemical fingerprinting of Salmonella typhimurium was investigated. Duplicate and replicate assays on 40 epidemiologically related and unrelated strains were performed in two batches of PhP-48......P-types which are epidemiologically unjustified, (ii) tests currently recommended for PhP-typing S. typhimurium may be somewhat unstable and not satisfactory for fingerprinting purposes, (iii) caution must be exercised when comparing data from different batches of PhP-48 plates, and (iv) best results are...

  17. A critical appraisal of the phene-plate biochemical fingerprinting system for epidemiological subtyping of Salmonella typhimurium

    DEFF Research Database (Denmark)

    On, S.L.W.; Baggesen, Dorte Lau

    1996-01-01

    The efficacy and reproducibility of the Phene-Plate (PhP) system (Biosys Inova, Stockholm, Sweden) for biochemical fingerprinting of Salmonella typhimurium was investigated. Duplicate and replicate assays on 40 epidemiologically related and unrelated strains were performed in two batches of PhP-48......P-types which are epidemiologically unjustified, (ii) tests currently recommended for PhP-typing S. typhimurium may be somewhat unstable and not satisfactory for fingerprinting purposes, (iii) caution must be exercised when comparing data from different batches of PhP-48 plates, and (iv) best results are...

  18. Application of quantitative autoradiography to the measurement of biochemical processes in vivo

    International Nuclear Information System (INIS)

    Quantitative autoradiography makes it possible to measure the concentrations of isotopes in tissues of animals labeled in vivo. In a few cases, the administration of a judiciously selected labeled chemical compound and a properly designed procedure has made it possible to use this capability to measure the rate of a chemical process in animals in vivo. Emission tomography, and particularly positron emission tomography, provides a means to extend this capability to man and to assay the rates of biochemical processes in human tissues in vivo. It does not, however, obviate the need to adhere to established principles of chemical and enzyme kinetics and tracer theory. Generally, all such methods, whether to be used in man with positron emission tomography or in animals with autoradiography, must first be developed by research in animals with autoradiography, because it is only in animals that the measurements needed to validate the basic assumptions of the methods can be tested and evaluated

  19. Comparative biochemical methane potential of paragrass using an unacclimated and an acclimated microbial consortium.

    Science.gov (United States)

    Nuchdang, Sasikarn; Khemkhao, Maneerat; Techkarnjanaruk, Somkiet; Phalakornkule, Chantaraporn

    2015-05-01

    The effect of inoculum sources on the anaerobic digestion of paragrass was investigated. Two types of sludge were used as the inoculums: an anaerobic sludge obtained from a domestic wastewater treatment plant (OS) and a sludge acclimated to fibrous substrates in raw palm oil mill effluent (AMC). Microbial activity assays showed that the AMC had hydrolytic and acetogenic activities two times greater than the activities of the OS. In addition, the production of methane from acetate by the AMC occurred without a lag phase, while it took 8 days for the OS to start producing methane from the same substrate. The biochemical methane potential after 80 days digestion was 316 ml STP/g VS(added) using the AMC, and 277 ml STP/g VS(added) using the OS. The methane potential of the paragrass was estimated to be 3337 Nm(3) CH4/ha a. PMID:25727758

  20. [Pre-analytical stability before centrifugation of 7 biochemical analytes in whole blood].

    Science.gov (United States)

    Perrier-Cornet, Andreas; Moineau, Marie-Pierre; Narbonne, Valérie; Plee-Gautier, Emmanuelle; Le Saos, Fabienne; Carre, Jean-Luc

    2015-01-01

    The pre-analytical stability of 7 biochemical parameters (parathyroid hormone -PTH-, vitamins A, C E and D, 1,25-dihydroxyvitamin D and insulin) at +4 °C, was studied on whole blood samples before centrifugation. The impact of freezing at -20°C was also analyzed/performed for PTH and vitamin D. The differences in the results of assays for whole blood samples, being kept for different times between sampling time and analysis, from 9 healthy adults, were compaired by using a Student t test. The 7 analytes investigated remained stable up to 4 hours at +4°C in whole blood. This study showed that it is possible to accept uncentrifuged whole blood specimens kept at +4°C before analysis. PTH is affected by freezing whereas vitamin D is not. PMID:26411912

  1. Biochemical, clinical and molecular findings in LCHAD and general mitochondrial trifunctional protein deficiency

    DEFF Research Database (Denmark)

    Olpin, S E; Clark, S; Andresen, B S;

    2005-01-01

    General mitochondrial trifunctional protein (TFP) deficiency leads to a wide clinical spectrum of disease ranging from severe neonatal/infantile cardiomyopathy and early death to mild chronic progressive sensorimotor poly-neuropathy with episodic rhabdomyolysis. Isolated long-chain 3-hydroxyacyl...... from an early age. We present biochemical, clinical and mutation data in 9 patients spanning the full spectrum of disease. Fibroblast acylcarnitine profiling shows good correlation with clinical phenotype using the ratio C18(OH)/(C14(OH)+C12(OH)). This ratio shows a gradation of values, from high in...... four patients with severe neonatal disease (2.5+/-0.8), to low in two neuromyopathic patients (0.35, 0.2). Fibroblast fatty acid oxidation flux assays also show correlation with the patient phenotype, when expressed either as percentage residual activity with palmitate or as a ratio of percentage...

  2. Evaluation of a Heparin-Calibrated Antifactor Xa Assay for Measuring the Anticoagulant Effect of Oral Direct Xa Inhibitors.

    Science.gov (United States)

    Beyer, Jacob; Trujillo, Toby; Fisher, Sheila; Ko, Ann; Lind, Stuart E; Kiser, Tyree H

    2016-07-01

    The introduction of oral direct anti-Xa anticoagulants apixaban and rivaroxaban has significantly impacted the treatment and prevention of thromboembolic disease. Clinical scenarios exist in which a quantitative assessment for degree of anticoagulation due to these agents would aid management. The purpose of this work was to evaluate the chromogenic antifactor Xa assay calibrated with heparin standards at our institution for assessment of intensity of anticoagulation with rivaroxaban or apixaban in addition to its current use for unfractionated heparin or low-molecular-weight heparin. We also aimed to propose expected steady state peak and trough antifactor Xa activities for these agents based upon dosing regimens approved for nonvalvular atrial fibrillation. Antifactor Xa activity correlated very strongly with apixaban and rivaroxaban concentration in both spiked samples and treated patient plasma samples (r (2) = .99, P < .001). This correlation was observed over a broad range (20-500 ng/mL) of drug concentrations, as sample dilution with pooled normal plasma significantly extended the range of quantitative assessment. Based on drug concentrations previously published in pharmacokinetic studies, the expected steady state peak and trough antifactor Xa activity ranges for apixaban are 1.80 to 2.20 IU/mL and 0.70 to 1.10 IU/mL, respectively. For rivaroxaban, these ranges are 3.80 to 6.20 IU/mL and 0.60 to 1.00 IU/mL, respectively. In conclusion, our findings demonstrate that heparin-calibrated antifactor Xa activity correlates strongly with apixaban and rivaroxaban concentration. The dilution of samples allowed for this correlation to be extended over the majority of on-therapy drug concentrations. PMID:26842561

  3. BIOCHEMICAL, NUTRIENT AND INHIBITORY CHARACTERISTICS OF STREPTOMYCES CULTURED FROM A HYPERSALINE ESTUARY, THE LAGUNA MADRE (TEXAS

    Directory of Open Access Journals (Sweden)

    Luis E. Espinoza

    2013-01-01

    Full Text Available Streptomyces are common soil bacteria that produce secondary metabolites, including several antibiotics; however, the characteristics of marine Streptomyces are largely unknown. Sediment samples were taken from 3 sites in the Laguna Madre to isolate marine Streptomyces. Sediment was diluted, spread onto synthetic seawater media to estimate the total bacterial density of the samples and spread onto starch casein agar to isolate Streptomyces. Isolated Streptomyces were tested for salinity tolerance and optimal growth pH. Isolates were assayed using API 20E® test strips and BIOLOG™ plates to construct biochemical profiles and assess nutrient utilization abilities of the bacteria, respectively. Individual Streptomyces were tested for the ability to inhibit the growth of other isolated Streptomyces (i.e., interference competition and putatively identified by DNA sequencing. Results showed that there was no significant difference in microbial density in sediments from the 3 sampling sites. Eleven (11 Streptomyces pure cultures were obtained in total; most tolerated salinity up to 60 ppt and grew optimally at pH 7.5. Biochemical profile comparisons showed that the Streptomyces were only at least 74% similar; most (8/11 were >90% similar. Isolates could use between 87-95 carbon sources. Three (3 isolates displayed interference toward other isolates. Ten (10 isolates were identified as Streptomyces griseus by DNA sequencing. Laguna Madre Streptomyces organisms display some diverse characteristics with regards to their halotolerance, biochemical profiles, carbon source utilization and inhibition toward other organisms. Further investigations may yield greater understanding of these organisms in this and other marine environments and may be a reservoir of novel microorganisms and secondary metabolites.

  4. Muscarinic acetylcholine receptor subtypes which selectively couple to phospholipase C: Pharmacological and biochemical properties

    International Nuclear Information System (INIS)

    The pharmacological and biochemical properties of rat m1 and m3 muscarinic acetylcholine receptors (mAChR) stably transfected into Chinese hamster ovary-K1 (CHO) cells were characterized with ligand binding, affinity labeling and biochemical assays. Both mAChR subtypes display saturable, high affinity binding of [3H]-quinuclidinyl benzilate (QNB) and a rank order of antagonist potency of QNB greater than atropine greater than pirenzepine greater than AF-DX 116. Carbachol displacement of [3H]-QNB binding to the m3 mAChR revealed an approximate 17-fold higher affinity than observed with the m1 mAChR. [3H]-propylbenzilylcholine mustard (PrBCM) labeling of mAChR revealed that m1 and m3 mAChR migrated on SDS-polyacrylamide gels with apparent molecular masses of 80,000 and 94,000 daltons, respectively, consistent with the known differences in their molecular sizes. Both m1 and m3 mAChR elicited dose-dependent increases in the hydrolysis of phosphoinositides; however, the maximal increase in total inositol phosphates elicited with the m1 mAChR was approximately 2-fold greater than that observed in cells expressing similar densities of m3 mAChR. Agonist activation of the m1 mAChR also elicited increases in basal and forskolin-stimulated cAMP, whereas the m3 mAChR had no effect on intracellular cAMP levels. These data suggest that although m1 and m3 mAChR display a considerable degree of structural homology, they exhibit distinct pharmacological and biochemical properties

  5. Muscarinic acetylcholine receptor subtypes which selectively couple to phospholipase C: Pharmacological and biochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Buck, M.A.; Fraser, C.M. (National Institute on Alcohol Abuse and Alcoholism, Rockville, MD (USA))

    1990-12-14

    The pharmacological and biochemical properties of rat m1 and m3 muscarinic acetylcholine receptors (mAChR) stably transfected into Chinese hamster ovary-K1 (CHO) cells were characterized with ligand binding, affinity labeling and biochemical assays. Both mAChR subtypes display saturable, high affinity binding of (3H)-quinuclidinyl benzilate (QNB) and a rank order of antagonist potency of QNB greater than atropine greater than pirenzepine greater than AF-DX 116. Carbachol displacement of (3H)-QNB binding to the m3 mAChR revealed an approximate 17-fold higher affinity than observed with the m1 mAChR. (3H)-propylbenzilylcholine mustard (PrBCM) labeling of mAChR revealed that m1 and m3 mAChR migrated on SDS-polyacrylamide gels with apparent molecular masses of 80,000 and 94,000 daltons, respectively, consistent with the known differences in their molecular sizes. Both m1 and m3 mAChR elicited dose-dependent increases in the hydrolysis of phosphoinositides; however, the maximal increase in total inositol phosphates elicited with the m1 mAChR was approximately 2-fold greater than that observed in cells expressing similar densities of m3 mAChR. Agonist activation of the m1 mAChR also elicited increases in basal and forskolin-stimulated cAMP, whereas the m3 mAChR had no effect on intracellular cAMP levels. These data suggest that although m1 and m3 mAChR display a considerable degree of structural homology, they exhibit distinct pharmacological and biochemical properties.

  6. Biochemical characterization of plant Rad52 protein from rice (Oryza sativa).

    Science.gov (United States)

    Nair, Anuradha; Agarwal, Rachna; Chittela, Rajani Kant

    2016-09-01

    DNA damage in living cells is repaired by two main pathways, homologous recombination (HR) and non-homologous end joining (NHEJ). Of all the genes promoting HR, Rad52 (Radiation sensitive 52) is an important gene which is found to be highly conserved across different species. It was believed that RAD52 is absent in plant systems until lately. However, recent genetic studies have shown the presence of RAD52 homologues in plants. Rad52 homologues in plant systems have not yet been characterized biochemically. In the current study, we bring out the biochemical properties of rice Rad52-2a protein. OsRad52-2a was over-expressed in Escherichia coli BL21 (DE3) cells and the protein was purified. The identity of purified OsRad52-2a protein was confirmed via peptide mass fingerprinting. Gel filtration and native PAGE analysis indicated that the OsRad52-2a protein in its native state probably formed an undecameric structure. Purified OsRad52-2a protein showed binding to single stranded DNA, double stranded DNA. Protein also mediated the renaturation of complementary single strands into duplex DNA in both agarose gel and FRET based assays. Put together, OsRad52-2a forms oligomeric structures and binds to ssDNA/dsDNA for mediating an important function like renaturation during homologous recombination. This study represents the first report on biochemical properties of OsRad52-2a protein from important crop like rice. This information will help in dissecting the recombination and repair machinery in plant systems. PMID:27156135

  7. Rapid and sensitive detection of major uropathogens in a single-pot multiplex PCR assay.

    Science.gov (United States)

    Padmavathy, B; Vinoth Kumar, R; Patel, Amee; Deepika Swarnam, S; Vaidehi, T; Jaffar Ali, B M

    2012-07-01

    Urinary tract infection (UTI) is among the most common bacterial infections and poses a significant healthcare burden. Escherichia coli is the most common cause of UTI accounting for up to 70 % and a variable contribution from Proteus mirabilis, Pseudomonas aeruginosa and Klebsiella pneumoniae. To establish a complete diagnostic system, we have developed a single-tube multiplex PCR assay (mPCR) for the detection of the above-mentioned four major uropathogens. The sensitivity of the assay was found to be as low as 10(2) cfu/ml of cells. The mPCR evaluated on 280 clinical isolates detected 100 % of E. coli, P. aeruginosa, P. mirabilis and 95 % of K. pneumonia. The assay was performed on 50 urine samples and found to be specific and sensitive for clinical diagnosis. In addition, the mPCR was also validated on spiked urine samples using 40 clinical isolates to demonstrate its application under different strain used in this assay. In total, mPCR reported here is a rapid and simple screening tool that can compete with conventional biochemical-based screening assays that may require 2-3 days for detection. PMID:22526571

  8. Assay to mechanically tune and optically probe fibrillar fibronectin conformations from fully relaxed to breakage.

    Science.gov (United States)

    Little, William C; Smith, Michael L; Ebneter, Urs; Vogel, Viola

    2008-06-01

    In response to growing needs for quantitative biochemical and cellular assays that address whether the extracellular matrix (ECM) acts as a mechanochemical signal converter to co-regulate cellular mechanotransduction processes, a new assay is presented where plasma fibronectin fibers are manually deposited onto elastic sheets, while force-induced changes in protein conformation are monitored by fluorescence resonance energy transfer (FRET). Fully relaxed assay fibers can be stretched at least 5-6 fold, which involves Fn domain unfolding, before the fibers break. In native fibroblast ECM, this full range of stretch-regulated conformations coexists in every field of view confirming that the assay fibers are physiologically relevant model systems. Since alterations of protein function will directly correlate with their extension in response to force, the FRET vs. strain curves presented herein enable the mapping of fibronectin strain distributions in 2D and 3D cell cultures with high spatial resolution. Finally, cryptic sites for fibronectin's N-terminal 70-kD fragment were found to be exposed at relatively low strain, demonstrating the assay's potential to analyze stretch-regulated protein-protein interactions. PMID:18417335

  9. THE SIDE-EFFECT OF ORGANIC INSECTICIDE SPINOSAD ON BIOCHEMICAL AND MICROBIOLOGICAL PROPERTIES OF CLAY SOIL

    Directory of Open Access Journals (Sweden)

    Arkadiusz Telesiński

    2015-09-01

    Full Text Available The aim of the study was to determine the effect of spinosad on soil biochemical and microbiological properties. The experiment was carried out on sandy loam with Corg content 10.91 g·kg-l. Spinosad, as Spintor 240 SC was added into soil in dosages: a recommended field dosage, and fivefold, tenfold, and twenty-fivefold higher dosages. The amount of spinosad introduced into soil was between 12.55 and 313.75 g·kg-l. Moreover, soil samples without spinosad supplement were prepared as a reference. Respective Spintor 240 SC doses were converted into 1 kg soil, taking into account 10 cm depth. After application of insecticide water emulsions, soil moisture was brought to 60% maximum holding water capacity. The soil was thoroughly mixed and stored in tightly-closed polyethylene bags at 20 °C for a period 4 weeks. During the experiment dissipation of spinosad, soil enzymes (dehydrogenase, alkaline phosphatase, acid phosphatase, urease and number of bacteria, fungi, actinomycetes were assayed. Obtained results showed, that dissipation of spinosad in soil was relatively fast – the DT50 of this insecticide was ranged between 1.11 and 2.21 days. Spinosad residues had different effects on soil microbiological and biochemical properties. However, over time the impact of this insecticide definitely decreased. This indicated that the use of spinosad in organic farming, particularly in the field dosage, does not pose a long-term threat to the soil environment.

  10. Evaluation of nutritional and biochemical parameters in spontaneously hypertensive rats following antihypertensive treatment

    Directory of Open Access Journals (Sweden)

    Joanna Suliburska

    2014-03-01

    Full Text Available Introduction. One side effect of antihypertensive drugs is their impact on nutritional status and metabolism. The purpose of this study was to assess the nutritional and biochemical parameters in spontaneously hypertensive rats following treatment with antihypertensive drugs. Material and methods. The experiment was performed on 50 male spontaneously hypertensive rats (SHR, which were assigned to fi ve groups: control (C, with perindopril (PR, with metoprolol (MT, with indapamide (ID, and with amlodipine (AM. All rats were provided ad libitum standard diet (with or without drugs and distilled water. After 45 days, the animals were weighed and killed. Liver, kidney, heart, spleen, pancreas, and blood samples were collected. Concentrations of glucose, cholesterol, triglycerides, and albumin were assayed in serum. Morphology parameters, such as white blood cell, red blood cell, hematocrit, and lymphocyte counts were measured in the blood. Blood pressure was measured using a tail-cuff plethysmograph. Results. The results obtained indicate that the hypotensive drugs under investigation had no effect on the selected nutritional parameters. Perindopril signifi cantly decreased the relative mass of the heart and amlodipine markedly decreased the relative mass of the pancreas. A markedly higher concentration of glucose in the group with indapamid, and a signifi cantly lower concentration of triglycerides in the group with metoprolol, were observed. Indapamide and amlodipine markedly increased the value of red blood cells and hematocrit in the blood of SHR. Conclusions. Long-term therapy with antihypertension drugs may infl uence tissue mass and biochemical and morphological status in the body.

  11. Biochemical basis of permethrin resistance in Anopheles arabiensis from Lower Moshi, north-eastern Tanzania

    Directory of Open Access Journals (Sweden)

    Oxborough Richard M

    2010-07-01

    Full Text Available Abstract Background Development of resistance to different classes of insecticides is a potential threat to malaria control. With the increasing coverage of long-lasting insecticide-treated nets in Tanzania, the continued monitoring of resistance in vector populations is crucial. It may facilitate the development of novel strategies to prevent or minimize the spread of resistance. In this study, metabolic-based mechanisms conferring permethrin (pyrethroid resistance were investigated in Anopheles arabiensis of Lower Moshi, Kilimanjaro region of north-eastern Tanzania. Methods WHO susceptibility test kits were used to detect resistance to permethrin in An. arabiensis. The levels and mechanisms of permethrin resistance were determined using CDC bottle bioassays and microplate (biochemical assays. In bottle bioassays, piperonyl butoxide (PBO and s,s,s-tributyl phosphorotrithioate (DEF were used as synergists to inhibit mixed function oxidases and non-specific esterases respectively. Biochemical assays were carried out in individual mosquitoes to detect any increase in the activity of enzymes typically involved in insecticide metabolism (mixed function oxidases, α- and β-esterases. Results Anopheles arabiensis from the study area was found to be partially resistant to permethrin, giving only 87% mortality in WHO test kits. Resistance ratios at KT50 and KT95 were 4.0 and 4.3 respectively. The permethrin resistance was partially synergized by DEF and by PBO when these were mixed with permethrin in bottle bioassays and was fully synergized when DEF and PBO were used together. The levels of oxidase and β-esterase activity were significantly higher in An. arabiensis from Lower Moshi than in the laboratory susceptible strain. There was no difference in α-esterase activity between the two strains. Conclusion Elevated levels of mixed function oxidases and β-esterases play a role in detoxification of permethrin in the resistant An. arabiensis population

  12. Molecular and biochemical characterization of methionine aminopeptidase of Babesia bovis as a potent drug target.

    Science.gov (United States)

    Munkhjargal, Tserendorj; Ishizaki, Takahiro; Guswanto, Azirwan; Takemae, Hitoshi; Yokoyama, Naoaki; Igarashi, Ikuo

    2016-05-15

    Aminopeptidases are increasingly being investigated as therapeutic targets in various diseases. In this study, we cloned, expressed, and biochemically characterized a member of the methionine aminopeptidase (MAP) family from Babesia bovis (B. bovis) to develop a potential molecular drug target. Recombinant B. bovis MAP (rBvMAP) was expressed in Escherichia coli (E. coli) as a glutathione S-transferase (GST)-fusion protein, and we found that it was antigenic. An antiserum against the rBvMAP protein was generated in mice, and then a native B. bovis MAP was identified in B. bovis by Western blot assay. Further, an immunolocalization assay showed that MAP is present in the cytoplasm of the B. bovis merozoite. Analysis of the biochemical properties of rBvMAP revealed that it was enzymatically active, with optimum activity at pH 7.5. Enhanced enzymatic activity was observed in the presence of divalent manganese cations and was effectively inhibited by a metal chelator, ethylenediaminetetraacetic acid (EDTA). Moreover, the enzymatic activity of BvMAP was inhibited by amastatin and bestatin as inhibitors of MAP (MAPi) in a dose-dependent manner. Importantly, MAPi was also found to significantly inhibit the growth of Babesia parasites both in vitro and in vivo; additionally, they induced high levels of cytokines and immunoglobulin (IgG) titers in the host. Therefore, our results suggest that BvMAP is a molecular target of amastatin and bestatin, and those inhibitors may be drug candidates for the treatment of babesiosis, though more studies are required to confirm this. PMID:27084466

  13. An ultrafiltration assay for lysyl oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Shackleton, D.R.; Hulmes, D.J. (Univ. of Edinburgh Medical School (England))

    1990-03-01

    A modification of the original microdistillation assay for lysyl oxidase is described in which Amicon C-10 microconcentrators are used to separate, by ultrafiltration, the 3H-labeled products released from a (4,5-3H)-lysine-labeled elastin substrate. Enzyme activity is determined by scintillation counting of the ultrafiltrate, after subtraction of radioactivity released in the presence of beta-aminopropionitrile, a specific inhibitor of the enzyme. Conditions are described which optimize both the sensitivity and the efficient use of substrate. The assay shows linear inhibition of activity in up to 1 M urea; hence, as the enzyme is normally diluted in the assay, samples in 6 M urea can be assayed directly, without prior dialysis, and corrected for partial inhibition. Comparable results are obtained when enzyme activity is assayed by ultrafiltration or microdistillation. The assay is simple and convenient and, by using disposable containers throughout, it eliminates the need for time-consuming decontamination of radioactive glassware.

  14. Assay development status report for total cyanide

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, B.C. [Westinghouse Hanford Co., Richland, WA (United States); Jones, T.E.; Pool, K.H. [Pacific Northwest Lab., Richland, WA (United States)

    1993-02-01

    A validated cyanide assay that is applicable to a variety of tank waste matrices is necessary to resolve certain waste tank safety issues and for purposes of overall waste characterization. The target for this effort is an assay with an applicable range of greater than 1,000 ppM (0.10 wt%) total cyanide and a confidence level greater than 80%. Figure 1 illustrates the operating regime of the proposed cyanide assay method. The Assay Development Status Report for Total Cyanide will summarize the past experience with cyanide analyses on-tank waste matrices and will rate the status of the analytical methods used to assay total cyanide (CN{sup {minus}} ion) in the tank waste matrices as acceptable or unacceptable. This paper will also briefly describe the current efforts for improving analytical resolution of the assays and the attempts at speciation.

  15. An ultrafiltration assay for lysyl oxidase

    International Nuclear Information System (INIS)

    A modification of the original microdistillation assay for lysyl oxidase is described in which Amicon C-10 microconcentrators are used to separate, by ultrafiltration, the 3H-labeled products released from a [4,5-3H]-lysine-labeled elastin substrate. Enzyme activity is determined by scintillation counting of the ultrafiltrate, after subtraction of radioactivity released in the presence of beta-aminopropionitrile, a specific inhibitor of the enzyme. Conditions are described which optimize both the sensitivity and the efficient use of substrate. The assay shows linear inhibition of activity in up to 1 M urea; hence, as the enzyme is normally diluted in the assay, samples in 6 M urea can be assayed directly, without prior dialysis, and corrected for partial inhibition. Comparable results are obtained when enzyme activity is assayed by ultrafiltration or microdistillation. The assay is simple and convenient and, by using disposable containers throughout, it eliminates the need for time-consuming decontamination of radioactive glassware

  16. Automated amperometric plutonium assay system

    International Nuclear Information System (INIS)

    The amperometric titration for plutonium assay has been used in the nuclear industry for over twenty years and has been in routine use at the Hanford Engineering Development Laboratory since 1976 for the analysis of plutonium oxide and mixed oxide fuel material for the Fast Flux Test Facility. It has proven itself to be an accurate and reliable method. The method may be used as a direct end point titration or an excess of titrant may be added and a back titration performed to aid in determination of the end point. Due to the slowness of the PuVI-FeII reaction it is difficult to recognize when the end point is being approached and is very time consuming if the current is allowed to decay to the residual value after each titrant addition. For this reason the back titration in which the rapid FeII-CrVI reaction occurs is used by most laboratories. The back titration is performed by the addition of excess ferrous solution followed by two measured aliquots of standard dichromate with measurement of cell current after each addition

  17. Development of a high-throughput cell-based reporter assay for screening JAK3 inhibitors

    OpenAIRE

    Yin, Chang-Hong; Bach, Erika A.; Baeg, Gyeong-Hun

    2011-01-01

    JAK3 has become an ideal target for the therapeutic treatment of immune-related diseases, as well as for the prevention of organ allograft rejection. A number of JAK3 inhibitors have been identified by in vitro biochemical enzymatic assays, but the majority display significant off-target effects on JAK2. Therefore, there is an urgent need to develop new experimental approaches to identify compounds that specifically inhibit JAK3. Here, we showed that in 32D/IL-2Rβ cells, STAT5 becomes phospho...

  18. Salivary immunoglobulin G assay to diagnose Helicobacter pylori infection in children.

    OpenAIRE

    LUZZA, F; Oderda, G; Maletta, M; Imeneo, M; Mesuraca, L; Chioboli, E; Lerro, P; Guandalini, S; Pallone, F.

    1997-01-01

    An in-house enzyme-linked immunosorbent assay (ELISA) for measurement of Helicobacter pylori-specific immunoglobulin G (IgG) and IgA in saliva was evaluated by comparison with histopathologic (Giemsa staining) and biochemical (urease quick test) examination of gastric biopsy specimens obtained from 112 children referred for diagnostic gastroscopy. Serum H. pylori IgG was also measured in a subgroup of 50 children by the same ELISA. Salivary H. pylori IgG levels were significantly higher in H....

  19. Matrix effects of TRU [transuranic] assays using the SWEPP PAN assay system

    International Nuclear Information System (INIS)

    The Drum Assay System (DAS) at the Stored Waste Experimental Pilot Plant (SWEPP) is a second-generation active-passive neutron assay system. It has been used to assay over 5000 208-liter drums of transuranic waste from the Rocky Flats Plant (RFP). Data from these assays have been examined and compared with the assays performed at Rocky Flats, mainly utilize counting of 239Pu gamma rays. For the most part the passive assays are in very good agreement with the Rocky Flats assays. The active assays are strongly correlated with the results of the other two methods, but require matrix-dependent correction factors beyond those provided by the system itself. A set of matrix-dependent correction factors has been developed from the study of the assay results. 3 refs., 4 figs., 3 tabs

  20. Assessment of biochemical concentrations of vegetation using remote sensing technology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The main biochemicals (such as lignin, protein, cellulose, sugar, starch, chlorophyll and water) of vegetation are directly or indirectly involved in major ecological processes, such as the functions of terrestrial ecosystems (i.e., nutrient-cycling processes, primary production, and decomposition). Remote sensing techniques provide a very convenient way of data acquisition capable of covering a large area several times during one season, so it can play a unique and essential role provided that we can relate remote sensing measurements to the biochemical characteristics of the Earth surface in a reliable and operational way. The application of remote sensing techniques for the estimation of canopy biochemicals was reviewed. Three methods of estimating biochemical concentrations of vegetation were included in this paper: index, stepwise multiple linear regression, and stepwise multiple linear regression based on a model of the forest crown. In addition, the vitality and potential applying value are stressed.

  1. Biochemical Aspects of Acclimatization of Man to High Altitude Stress

    Directory of Open Access Journals (Sweden)

    K. K. Srivastava

    1975-07-01

    Full Text Available The paper reviews the biochemical aspects of acclimatization of human body to high altitude with particular reference to the adaptive changes in Skeletal muscles, hepatic function, adrenal function and carbohydrate metabolism.

  2. NERVOUS-SYSTEM SPECIFIC PROTEINS AS BIOCHEMICAL INDICATORS OF NEUROTOXICITY

    Science.gov (United States)

    Recent advances in neuroimmunology and protein purification methodology have led to the identification of nervous-system specific proteins. Their intimate relationship to the cellular and functional heterogeneity of the nervous system, makes these proteins ideal biochemical marke...

  3. 2011 Biomass Program Platform Peer Review: Biochemical Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Pezzullo, Leslie [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2012-02-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the 2011 U.S. Department of Energy Biomass Program’s Biochemical Conversion Platform Review meeting.

  4. Immunofluorescence Assay for Serologic Diagnosis of SARS

    OpenAIRE

    Chan, Paul K. S.; Ng, King-Cheung; Chan, Rickjason C. W.; Lam, Rebecca K. Y.; Chow, Viola C. Y.; Hui, Mamie; Wu, Alan; Lee, Nelson; Yap, Florence H.Y.; Cheng, Frankie W.T.; Joseph J. Y. Sung; Tam, John S

    2004-01-01

    We evaluated a virus-infected cell-based indirect immunofluorescence assay for detecting anti–severe acute respiratory syndrome-associated coronavirus (SARS-CoV) immunoglobulin (Ig) G antibody. All confirmed SARS cases demonstrated seroconversion or fourfold rise in IgG antibody titer; no control was positive. Sensitivity and specificity of this assay were both 100%. Immunofluorescence assay can ascertain the status of SARS-CoV infection.

  5. Trypan blue exclusion assay by flow cytometry

    OpenAIRE

    Avelar-Freitas, B.A.; V.G. Almeida; Pinto, M.C.X.; F.A.G. Mourão; A.R. Massensini; O.A. Martins-Filho; E. Rocha-Vieira; G.E.A. Brito-Melo

    2014-01-01

    Dye exclusion tests are used to determine the number of live and dead cells. These assays are based on the principle that intact plasma membranes in live cells exclude specific dyes, whereas dead cells do not. Although widely used, the trypan blue (TB) exclusion assay has limitations. The dye can be incorporated by live cells after a short exposure time, and personal reliability, related to the expertise of the analyst, can affect the results. We propose an alternative assay for evaluating ce...

  6. Safeguards and Non-destructive Assay

    International Nuclear Information System (INIS)

    SCK-CEN's programme on safeguards and non-destructive assay includes: (1) various activities to assure nuclear materials accountancy; (2) contributes to the implementation of Integrated Safeguards measures in Belgium and to assist the IAEA through the Belgian Support Programme; (3) renders services to internal and external customers in the field of safeguards; (4) improves passive neutron coincidence counting techniques for waste assay and safeguards verification measurements by R and D on correlation algorithms implemented via software or dedicated hardware; (5) improves gamma assay techniques for waste assay by implementing advanced scanning techniques and different correlation algorithms; and (6) develops numerical calibration techniques. Major achievements in these areas in 2000 are reported

  7. Anatomical and biochemical investigation of primary brain tumours

    International Nuclear Information System (INIS)

    Cancerous transformation entails major biochemical changes including modifications of the energy metabolism of the cell, e.g. utilisation of glucose and other substrates, protein synthesis, and expression of receptors and antigens. Tumour growth also leads to heterogeneity in blood flow owing to focal necrosis, angiogenesis and metabolic demands, as well as disruption of transport mechanisms of substrates across cell membranes and other physiological boundaries such as the blood-brain barrier. All these biochemical, histological and anatomical changes can be assessed with emission tomography, X-ray computed tomography (CT), magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Whereas anatomical imaging is aimed at the diagnosis of brain tumours, biochemical imaging is better suited for tissue characterisation. The identification of a tumoural mass and the assessment of its size and vascularisation are best achieved with X-ray CT and MRI, while biochemical imaging can provide additional information that is crucial for tumour classification, differential diagnosis and follow-up. As the assessment of variables such as water content, appearance of cystic lesions and location of the tumour are largely irrelevant for tissue characterisation, a number of probes have been employed for the assessment of the biochemical features of tumours. Since biochemical changes may be related to the growth rate of cancer cells, they can be thought of as markers of tumour cell proliferation. Biochemical imaging with radionuclides of processes that occur at a cellular level provides information that complements findings obtained by anatomical imaging aimed at depicting structural, vascular and histological changes. This review focusses on the clinical application of anatomical brain imaging and biochemical assessment with positron emission tomography, single-photon emission tomography and MRS in the diagnosis of primary brain tumours, as well as in follow-up. (orig.)

  8. Biomphalaria prona (Gastropoda: Planorbidae): a morphological and biochemical study

    OpenAIRE

    W. Lobato Paraense; Pointier, J.P.; Delay, B.; A. F. Pernot; Incani, R N; C. Balzan; P. Chrosciechowski

    1992-01-01

    Two samples of Biomphalaria prona (Martens, 1873) from Lake Valencia (type locality) and seven from other Venezuelan localities were studied morphologically (shell and reproductive system) and biochemically (allozyme electrophoresis). In spite of marked differences in shell characters, all of them proved indistinguishable under the anatomic and biochemical criteria. So far B. prona has been considered an endemic species, restricted to Lake Valencia. It is now demonstrated that the extralacust...

  9. Correlations between female breast density and biochemical markers

    OpenAIRE

    Kim, Ji-Hye; Lee, Hae-Kag; Cho, Jae-Hwan; Park, Hyong-Keun; Yang, Han-Jun

    2015-01-01

    [Purpose] The aim of this study was to identify biochemical markers related to breast density. The study was performed with 200 patients who received mammography and biochemical marker testing between March 1, 2014 to October 1, 2014. [Subjects and Methods] Following the American College of Radiology, Breast Imaging Reporting and Data System (ACR BI-RADS), breast parenchymal pattern density from mammography was categorized into four grades: grade 1, almost entirely fat; grade 2, fibroglandula...

  10. Serum Biochemical Profile of Post Partum Metritic Cow

    OpenAIRE

    Magnus P. K.; Lali F. A.

    2009-01-01

    Present study was conducted to find out the relationship between serum biochemical profile and postpartum metritis. Mainly serum glucose, total protein, albumin, albumin globulin ratio, blood urea nitrogen (BUN), creatinine and calcium were studied. Colorimetric method was used for quantitative estimation of biochemical profile. Twenty-seven animals with recent history of calving and subsequent metritis were included in the study. On analysis, serum glucose was found to be 22.3 ± 2.1...

  11. Murine interleukin 2 receptor. IV. Biochemical characterization

    International Nuclear Information System (INIS)

    The IL 2 receptor isolated from the IL 2-dependent CTL-L cell line was subjected to biochemical analysis. Pulse-chase and tunicamycin studies, as well as digestion with the endoglycosidases, Endo-F and Endo-H, of 35S-methionine-labeled IL 2 receptors suggested a single protein pecursor of 32,000 (p32) daltons. The p32 precursor was rapidly processed by addition of high-mannose-containing core N-linked sugars to intracytoplasmic precursor intermediates of 38,000 (p38) and 40,000 (p40) daltons, which undergo further processing to yield a mature surface receptor with heterogeneous apparent m.w. of 52,000 to 65,000 (p58). Two-dimensional gel studies indicated that p58 exhibited broad charge heterogeneity between pH 4.6 and 6.3. Endo-F digestions of p58 shifted the isoelectric focus point to a more basic 5.5 to 7.4. This considerable charge heterogeneity is consistent with the possibility that other post-translational modifications to the mouse IL 2 receptor occur besides addition of complex N-linked glycans. Immunoprecipitations of the IL 2 receptor from surface iodinated cells also revealed an additional band at 110,000 (p110) daltons. IEF vs SDS-PAGE two-dimensional gel studies demonstrated that p110 also had an isoelectric focus point identical to p58. Western blot studies with an anti-IL 2 receptor monoclonal antibody (7D4) demonstrates that p38, p40, p58, and p110 each expressed the epitope recognized by this antibody. Thus, it is likely that p110 is not a unique molecule that coprecipitates with IL 2 receptor. Western blot analysis of mitogen-stimulated T and B lymphocytes also revealed bands similar to p58 and p110, although these bands had an average apparent m.w. 3000 and 6000 less than those seen for CTL-L cells

  12. Biochemical Methods to Analyze Wnt Protein Secretion.

    Science.gov (United States)

    Glaeser, Kathrin; Boutros, Michael; Gross, Julia Christina

    2016-01-01

    Wnt proteins act as potent morphogens in various aspects of embryonic development and adult tissue homeostasis. However, in addition to its physiological importance, aberrant Wnt signaling has been linked to the onset and progression of different types of cancer. On the cellular level, the secretion of Wnt proteins involves trafficking of lipid-modified Wnts from the endoplasmic reticulum (ER) to Golgi and further compartments via the Wnt cargo receptor evenness interrupted. Others and we have recently shown that Wnt proteins are secreted on extracellular vesicles (EVs) such as microvesicles and exosomes. Although more details about specific regulation of Wnt secretion steps are emerging, it remains largely unknown how Wnt proteins are channeled into different release pathways such as lipoprotein particles, EVs and cytonemes. Here, we describe protocols to purify and quantify Wnts from the supernatant of cells by either assessing total Wnt proteins in the supernatant or monitoring Wnt proteins on EVs. Purified Wnts from the supernatant as well as total cellular protein content can be investigated by immunoblotting. Additionally, the relative activity of canonical Wnts in the supernatant can be assessed by a dual-luciferase Wnt reporter assay. Quantifying the amount of secreted Wnt proteins and their activity in the supernatant of cells allows the investigation of intracellular trafficking events that regulate Wnt secretion and the role of extracellular modulators of Wnt spreading. PMID:27590148

  13. A radiochemical assay for biotin in biological materials

    International Nuclear Information System (INIS)

    A radiochemical assay for biotin is described. The assay was sensitive to one nanogram and simple enough for routine biotin analyses. The assay yielded results which were comparable to those obtained from a microbiological assay using Lactobacillus plantarum. (author)

  14. LT-HSC Methylcellulose Assay

    Science.gov (United States)

    Kerenyi, Marc A.

    2016-01-01

    Hematopoietic differentiation is a highly complex process originating from an extraordinary population of cells called long-term repopulating hematopoietic stem cells (LT-HSCs). The unique feature of all stem cells, including HSCs, is their exceptional ability to divide asymmetrically giving rise to two different kinds of offspring. One daughter cell becomes an LT-HSC itself (self-renews) to maintain the LT-HSC pool, whereas the second daughter cell pursues a differentiation fate to ultimately give rise to terminally differentiated mature blood cells (Orkin and Zon, 2008). Quantification of phenotypic LT-HSCs can be performed by multi-color flow cytometry and the gold standard for assessment of LT-HSC self-renewal and function is competitive bone marrow transplantation (Miller et al., 2008). Although these methods are irreplaceable to determine LT-HSC abundance and functionality, they have their disadvantages and limitations. For example, competitive bone marrow transplantation is typically monitored as a function of peripheral blood donor contribution over 12–16 weeks. While reduced peripheral blood donor contribution by itself signifies impairment in the stem/progenitor cells compartment, it cannot unambiguously discriminate between reduced LT-HSC self-renewal, impaired LT-HSC differentiation or compromised progenitor cell differentiation. Here we describe an LT-HSCs methylcellulose colony-forming assay, as a fast complementary in vitro method to directly assess LT-HSC differentiation capacity. As described in Kerenyi et al. (2013), this technique acts as a powerful tool to differentiate between LT-HSC or progenitor cell differentiation defects.

  15. Fully Automated RNAscope In Situ Hybridization Assays for Formalin-Fixed Paraffin-Embedded Cells and Tissues.

    Science.gov (United States)

    Anderson, Courtney M; Zhang, Bingqing; Miller, Melanie; Butko, Emerald; Wu, Xingyong; Laver, Thomas; Kernag, Casey; Kim, Jeffrey; Luo, Yuling; Lamparski, Henry; Park, Emily; Su, Nan; Ma, Xiao-Jun

    2016-10-01

    Biomarkers such as DNA, RNA, and protein are powerful tools in clinical diagnostics and therapeutic development for many diseases. Identifying RNA expression at the single cell level within the morphological context by RNA in situ hybridization provides a great deal of information on gene expression changes over conventional techniques that analyze bulk tissue, yet widespread use of this technique in the clinical setting has been hampered by the dearth of automated RNA ISH assays. Here we present an automated version of the RNA ISH technology RNAscope that is adaptable to multiple automation platforms. The automated RNAscope assay yields a high signal-to-noise ratio with little to no background staining and results comparable to the manual assay. In addition, the automated duplex RNAscope assay was able to detect two biomarkers simultaneously. Lastly, assay consistency and reproducibility were confirmed by quantification of TATA-box binding protein (TBP) mRNA signals across multiple lots and multiple experiments. Taken together, the data presented in this study demonstrate that the automated RNAscope technology is a high performance RNA ISH assay with broad applicability in biomarker research and diagnostic assay development. J. Cell. Biochem. 117: 2201-2208, 2016. © 2016 Wiley Periodicals, Inc. PMID:27191821

  16. Polymerase chain reaction assay for detection of Staphylococcus aureus in buffalo milk

    Directory of Open Access Journals (Sweden)

    V.K. Jain

    2010-02-01

    Full Text Available In India, Haryana has the world’s best dairy type buffalo, the Murrah capable of milk yields as high as 35 kg a day. Clinical and Sub clinical mastitis exerts a negative impact on milk quality, quantity and animal health and profits. In India, Staphylococci are the main causative agents responsible for mastitis of economic importance. Therefore, a suitable and specific test is required for the rapid diagnosis of Staphylococcus aureus. For definitive diagnosis of Staphylococcus aureus in mastitic milk, a polymerase chain reaction assay was developed using target sequence of 16S to 23S rRNA spacer region. This test can be performed within hours and avoids cumbersome and lengthy steps involved in microbiological culture of milk and biochemical tests. Polymerase chain reaction assay can be used as a screening test for a large herd to detect Staphylococcus aureus in milk.

  17. Seasonal influence on biochemical profile and serum protein electrophoresis for Boa constrictor amarali in captivity.

    Science.gov (United States)

    Silva, L F N; Riani-Costa, C C M; Ramos, P R R; Takahira, R K

    2011-05-01

    Similarly to other reptiles, snakes are ectothermic animals and depend exclusively on the environment for the maintenance of their physiological, biochemical and immunological processes. Thus, changes in biochemical values can be expected due to seasonal influence. Twenty-two adult specimens of Boa constrictor amarali kept in captivity were used. Blood collections were done in two different seasons: winter (July 2004) and summer (January 2005) for the following assays: uric acid, aspartate aminotransferase (AST), glucose, cholesterol, total protein, and serum protein electrophoresis. The mean biochemical results found in summer and winter, respectively, were: 6.3 ± 3.4 and 11.3 ± 6.2 mg/dL for uric acid; 28.7 ± 12.4 and 20.7 ± 16.2 UI/L for AST; 26.3 ± 17 and 17.4 ± 6.8 mg/dL for glucose; 67.3 ± 30.2 and 69.7 ± 38.5 mg/dL for cholesterol; and 5.9 ± 1.6 and 5.9 ± 1.4 g/dL for total protein. Results regarding electrophoresis in summer and winter, respectively, were: 1.9 ± 0.7 and 2.4 ± 0.6 g/dL for albumin; 0.7 ± 0.2 and 0.5 ± 0.2 g/dL for α-globulin; 1.5 ± 0.5 and 1.7 ± 0.6 g/dL for β-globulin; and 1.8 ± 0.5 and 1.5 ± 0.5 g/dL for γ-globulin. In the summer, there was a significant increase in AST and a decrease in uric acid (p < 0.05). Serum protein electrophoresis showed a significant increase in α-globulin fraction (p < 0.05) in the same season. There were not significant differences between seasons for the remaining variables. Based on these results, the period of the year must be considered in the interpretation of some biochemical values for these animals. PMID:21755171

  18. Acellular comet assay: A tool for assessing variables influencing the alkaline comet assay

    International Nuclear Information System (INIS)

    In this study, an acellular modification to the alkaline comet assay to further evaluate key variables within the assay that may influence the outcome of genotoxicity studies is described. This acellular comet assay can detect differences of 0.2 Gy of 60Co gamma-ray radiation between 0 and 1 Gy and differences of 1 Gy between 0 and 8 Gy; thus, this assay is applicable for a wide range of DNA damage levels. It is also shown that DNA damage from different radiation energies was not significantly different from 60Co gamma-ray. This assay displayed a statistical increase in DNA damage due to uncontrolled exposure to natural light; however, the slope of the dose-response curve for light-exposed samples was similar to that for samples protected from light. A comparison of the alkaline comet assay with the acellular comet assay allowed for the intrinsic repair capacity of the alkaline comet assay to be quantified. (authors)

  19. Development of an upconverting chelate assay

    Science.gov (United States)

    Xiao, Xudong; Haushalter, Jeanne P.; Kotz, Kenneth T.; Faris, Gregory W.

    2005-04-01

    We report progress on performing a cell-based assay for the detection of EGFR on cell surfaces by using upconverting chelates. An upconversion microscope has been developed for performing assays and testing optical response. A431 cells are labeled with europium DOTA and imaged using this upconverting microscope.

  20. A bioluminescent assay for measuring glucose uptake.

    Science.gov (United States)

    Valley, Michael P; Karassina, Natasha; Aoyama, Natsuyo; Carlson, Coby; Cali, James J; Vidugiriene, Jolanta

    2016-07-15

    Identifying activators and inhibitors of glucose uptake is critical for both diabetes management and anticancer therapy. To facilitate such studies, easy-to-use nonradioactive assays are desired. Here we describe a bioluminescent glucose uptake assay for measuring glucose transport in cells. The assay is based on the uptake of 2-deoxyglucose and the enzymatic detection of the 2-deoxyglucose-6-phosphate that accumulates. Uptake can be measured from a variety of cell types, it can be inhibited by known glucose transporter inhibitors, and the bioluminescent assay yields similar results when compared with the radioactive method. With HCT 116 cells, glucose uptake can be detected in as little as 5000 cells and remains linear up to 50,000 cells with signal-to-background values ranging from 5 to 45. The assay can be used to screen for glucose transporter inhibitors, or by multiplexing with viability readouts, changes in glucose uptake can be differentiated from overall effects on cell health. The assay also can provide a relevant end point for measuring insulin sensitivity. With adipocytes and myotubes, insulin-dependent increases in glucose uptake have been measured with 10- and 2-fold assay windows, respectively. Significant assay signals of 2-fold or more have also been measured with human induced pluripotent stem cell (iPSC)-derived cardiomyocytes and skeletal myoblasts. PMID:27130501

  1. Radioreceptor assay: theory and applications to pharmacology

    International Nuclear Information System (INIS)

    The aim of the first part of this work is to present the theory of the radioreceptor assay and to compare it to the other techniques of radioanalysis (radioimmunoassay, competitive protein binding assays). The technology of the radioreceptor assay is then presented and its components (preparation of the receptors, radioligand, incubation medium) are described. The analytical characteristics of the radioreceptor assay (specificity, sensitivity, reproductibility, accuracy) and the pharmacological significance of the results are discussed. The second part is devoted to the description of the radioreceptor assays of some pharmacological classes (neuroleptics, tricyclic antidepressants, benzodiazepines, β-blockers, anticholinergic drugs) and to their use in therapeutic drug monitoring. In conclusion, by their nature, radioreceptor assays are highly sensitive, reliable, precise, accurate and simple to perform. Their chief disadvantage relates to specificity, since any substance having an appreciable affinity to the receptor site will displace the specifically bound radioligand. Paradoxically in some cases, this lack of specificity may be advantageous in that it allows for the detection of not only the apparent compound but of active metabolites and endogenous receptor agonists as well and in that radioreceptors assays can be devised for a whole pharmacological class and not only for one drug as it is the case for classical physico-chemical techniques. For all these reasons future of radioreceptor assay in pharmacology appears promising

  2. Assessing sediment contamination using six toxicity assays

    Directory of Open Access Journals (Sweden)

    Allen G. BURTON Jr.

    2001-08-01

    Full Text Available An evaluation of sediment toxicity at Lake Orta, Italy was conducted to compare a toxicity test battery of 6 assays and to evaluate the extent of sediment contamination at various sediment depths. Lake Orta received excessive loadings of copper and ammonia during the 1900’s until a large remediation effort was conducted in 1989-90 using lime addition. Since that time, the lake has shown signs of a steady recovery of biological communities. The study results showed acute toxicity still exists in sediments at a depth of 5 cm and greater. Assays that detected the highest levels of toxicity were two whole sediment exposures (7 d using Hyalella azteca and Ceriodaphnia dubia. The MicrotoxR assay using pore water was the third most sensitive assay. The Thamnotox, Rototox, Microtox solid phase, and Seed Germination-Root Elongation (pore and solid phase assays showed occasional to no toxicity. Based on similarity of responses and assay sensitivity, the two most useful assays were the C. dubia (or H. azteca and Microtox pore water. These assays were effective at describing sediment toxicity in a weight-of-evidence approach.

  3. Simple UV spectrophotometric assay of Clarithromycin

    Directory of Open Access Journals (Sweden)

    Dr. Safila Naveed

    2014-09-01

    Full Text Available Clarithromycin belongs to semi-synthetic macrolide antibiotic class of drugs that inhibits bacterial protein synthesis.. Our aim of study is to develop a efficient least time consuming and simple spectrophotometric method for the assay of clarithromycin. Comparision of assay of five different brands of clarithromycin (klaricid,klaribact,rithmo,clariteck,E-clark available in public medical store of Karachi, Pakistan has also been done. The assay is based on the ultraviolet UV absorbance maxima at about 210nm wavelength of mefenamic acid, water is used as solvent. A sample of drug was dissolved in water to produce a solution containing mefenamic acid. Similarly, a sample of ground tablets of different brand were dissolved in water and various dilutions were made. The absorbance of sample preparation was measured at 210nm against the solvent blank and the assay was determined by comparing with the absorbance of available brand. Our results reveals that among all the five brands of clarithromycin (klaricid,klaribact,rithmo,clariteck,E-clark Klaribact shows highest percentage assay i.e 115.3846%. Klaricid and Claritecl shows percentage assay of 107.693%. Rithmo shows a percent assay of 92.307% while E-clark shows lowest value for percentage assay 84.6153%

  4. Practical radiochromatographic assay for cholesterol epoxide hydrase

    International Nuclear Information System (INIS)

    A method for the assay of cholesterol epoxide hydrase activity is described. The assay involves the thin-layer chromatographic separation and quantitation of radiolabeled cholestan-3β,5α,6α-epoxide and its major hydration product, cholestan-3β,5α,6β-triol. Radiochromatographic scanning is employed to quantitate the reaction. The procedure is sensitive, rapid, and nondestructive

  5. Reconciling Apparent Variability in Effects of Biochar Amendment on Soil Enzyme Activities by Assay Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Vanessa L.; Fansler, Sarah J.; Smith, Jeffery L.; Bolton, Harvey

    2011-02-01

    Applying biochar to soils as an ameliorative substance and mechanism for C sequestration has received a great deal of interest in light of the sustained fertility observed in the Terra Preta soils of Brazil. The effects of synthetic biochars on biochemical processes needs to be better understood in order to determine if this is a reasonable practice in managed systems. The biochar studied was formed from the fast-pyrolysis of a switchgrass feedstock. Four soil enzymes were studied: β-glucosidase, β-N-acetylglucosaminidase, lipase, and leucine aminopeptidase. Both colorimetric and fluorescent assays were used for β-glucosidase and β-N-acetylglucosaminidase. Seven days after biochar was added to microcosms of a Palouse silt loam, the fluorescence-based assays indicated increased activities of the four enzymes, compared to non-amended soil. To clarify the mechanisms of the observed effects,in the absence of soil, purified enzymes or substrates were briefly exposed to biochar and then assayed. Except for β-N-acetylglucosaminidase, the exposure of substrate to biochar reduced the apparent activity of the remaining three enzymes in vitro, suggesting that sorption reactions between the substrate and biochar either removed the substrate from the assays or impeded the enzyme binding. The activity of purified β-N-acetylglucosaminidase increased significantly following biochar exposure, suggesting a chemical stimulation of enzyme functioning. We conclude that biochar added to soil acts as a substrate that can stimulate the soil microbial biomass and its activity. Our in vitro study suggests that biochar is not biochemically inert. Biochar amendments are likely to have effects that are currently difficult to predict, and that could impact overall soil function.

  6. BIOCHEMICAL STUDIES ON NIGERIAN MONODORA TENUIFOLIA SEED

    Directory of Open Access Journals (Sweden)

    Ekeanyanwu Raphael Chukwuma

    2013-01-01

    Full Text Available The nutritive constituents of the seeds of Monodora tenuifolia were analyzed to augment the available information on Monodora tenuifolia research. Blood glucose and lipid profile were investigated on the flavonoid rich fraction of M. tenuifolia in rats. The composition (gkg-1 of alkaloids, cyanogenic glycosides, tannins and flavonoids were 13.3±0.1, 21.2×10-2±0.6, 1.3±0.1, 1.7±0.1 and 11.7±1.1 respectively. The proximate composition (gkg-1 of M. tenuifolia seed were crude fibre (262.3±1.2, crude protein (82.6±1.0, crude fat (349.9±1.9, ash (49.9±0.6, moisture (190.0±0.00 and carbohydrate (65.5±4.7. Analysis of the minerals content (gkg-1 yielded calcium (864.0±29.38, sodium (2752.0±140.35, iron (3.34±0.06, zinc (5.26±0.08, potassium (326.4±13.06, magnesium (342.9±13.71 and phosphorus (9.52±0.17, while vitamin analysis yielded vitamin A (10.05±0.17 iu/100 g, C (56.40±0.14 gkg-1 and E (11.71±0.87 iu /100 g, thiamine (0.11±0.01 gkg-1, niacin (0.46±0.32 gkg-1 and riboflavin (0.04±0.01 gkg-1. The results of amino acid analysis showed the total amino acid of M. tenuifolia seed was 71.78 of crude protein. The total essential amino acid with Histidine was calculated to be 29.24 of the crude protein. The antinutrient analysis of M. tenuifolia shows it contained total phenol (0.8±0.0 gkg-1, oxalates (4.09±1.17 gkg-1, phytates (0.012±0.42 gkg-1 and trypsin inhibitor (0.230±0.42 iu/g. The main fatty acids of the seed oil are linoleic acid (401.7 g kg-1, oleic acid (346.1 g kg-1 and palmitic acid (122.61 g kg-1. The LD50 of the flavonoid-rich fraction was found to be above 5000 mg kg-1 b.w. After the day 14 study, biochemical markers such as triacylglycerol, very low density lipoprotein increased significantly (p0.05 effect was observed on the blood glucose and lipid profile of wistar albino rats compared with the control. The result shows that M. tenuifolia seed is rich

  7. Biochemical and histological characterization of tomato mutants

    Directory of Open Access Journals (Sweden)

    Carolina C. Monteiro

    2012-06-01

    Full Text Available Biochemical responses inherent to antioxidant systems as well morphological and anatomical properties of photomorphogenic, hormonal and developmental tomato mutants were investigated. Compared to the non-mutant Micro-Tom (MT, we observed that the malondialdehyde (MDA content was enhanced in the diageotropica (dgt and lutescent (l mutants, whilst the highest levels of hydrogen peroxide (H2O2 were observed in high pigment 1 (hp1 and aurea (au mutants. The analyses of antioxidant enzymes revealed that all mutants exhibited reduced catalase (CAT activity when compared to MT. Guaiacol peroxidase (GPOX was enhanced in both sitiens (sit and notabilis (not mutants, whereas in not mutant there was an increase in ascorbate peroxidase (APX. Based on PAGE analysis, the activities of glutathione reductase (GR isoforms III, IV, V and VI were increased in l leaves, while the activity of superoxide dismutase (SOD isoform III was reduced in leaves of sit, epi, Never ripe (Nr and green flesh (gf mutants. Microscopic analyses revealed that hp1 and au showed an increase in leaf intercellular spaces, whereas sit exhibited a decrease. The au and hp1 mutants also exhibited a decreased in the number of leaf trichomes. The characterization of these mutants is essential for their future use in plant development and ecophysiology studies, such as abiotic and biotic stresses on the oxidative metabolism.Neste trabalho, analisamos as respostas bioquímicas inerentes ao sistema antioxidante, assim como propriedades morfológicas e anatômicas de mutantes fotomorfogenéticos e hormonais de tomateiro. Comparados ao não mutante Micro-Tom (MT, observamos que o conteúdo de malondialdeído (MDA aumentou nos mutantes diageotropica (dgt e lutescent (l, enquanto os maiores níveis de H2O2 foram encontrados nos mutantes high pigment 1 (hp1 e aurea (au. Análises de enzimas antioxidantes mostraram que todos os mutantes reduziram a atividade de catalase (CAT quando comparado a MT. A

  8. Probabilistic interpretation of radioactive waste assay

    International Nuclear Information System (INIS)

    The non-destructive assay of radioactive wastes from nuclear power plants and fuel cycle facilities is required for assessing the disposal risks. Such assay is influenced by two distinct facts: the statistical uncertainty of the measurement and the spatial uncertainty due to the random or at least unknown spatial distribution of the assayed material in a waste container. In this paper a probabilistic interpretation procedure is presented for a single-detector assay system of nuclear waste by one-shot passive gamma technique. The key parameter for this study, the average escape probability for photons, has been obtained by a specific-purpose Monte Carlo code, MCRW. The code has been developed to simulate the entire pulse height spectral responses for point sources located within the compartment which is the basic idea describing the degree of spatial homogeneity of the nuclear and matrix materials. The methodology presented here can be extended to actual radioactive waste assay

  9. The haemolytic antibody isotope release (HAIR) assay; an efficient alternative technique to conventional plaque assays

    International Nuclear Information System (INIS)

    The haemolytic antibody isotope release (HAIR) assay quantitates antibody production by splenic antibody-producing cells by lysis of chromium-51-labelled sheep red blood cells. The amount of antibody quantitated by the HAIR assay directly correlates with the number of antibody-producing cells measured by a conventional plaque assay. The HAIR assay is an easy, sensitive, and reproducible technique that is especially useful when large numbers of animals are required for testing. (author)

  10. Determination of cell survival after irradiation via clonogenic assay versus multiple MTT Assay - A comparative study

    OpenAIRE

    Buch Karl; Peters Tanja; Nawroth Thomas; Sänger Markus; Schmidberger Heinz; Langguth Peter

    2012-01-01

    Abstract For studying proliferation and determination of survival of cancer cells after irradiation, the multiple MTT assay, based on the reduction of a yellow water soluble tetrazolium salt to a purple water insoluble formazan dye by living cells was modified from a single-point towards a proliferation assay. This assay can be performed with a large number of samples in short time using multi-well-plates, assays can be performed semi-automatically with a microplate reader. Survival, the calc...

  11. Extracellular α-Galactosidase from Trichoderma sp. (WF-3: Optimization of Enzyme Production and Biochemical Characterization

    Directory of Open Access Journals (Sweden)

    Aishwarya Singh Chauhan

    2015-01-01

    Full Text Available Trichoderma spp. have been reported earlier for their excellent capacity of secreting extracellular α-galactosidase. This communication focuses on the optimization of culture conditions for optimal production of enzyme and its characterization. The evaluation of the effects of different enzyme assay parameters such as stability, pH, temperature, substrate concentrations, and incubation time on enzyme activity has been made. The most suitable buffer for enzyme assay was found to be citrate phosphate buffer (50 mM, pH 6.0 for optimal enzyme activity. This enzyme was fairly stable at higher temperature as it exhibited 72% activity at 60°C. The enzyme when incubated at room temperature up to two hours did not show any significant loss in activity. It followed Michaelis-Menten curve and showed direct relationship with varying substrate concentrations. Higher substrate concentration was not inhibitory to enzyme activity. The apparent Michaelis-Menten constant (Km, maximum rate of reaction (Vmax, Kcat, and catalytic efficiency values for this enzyme were calculated from the Lineweaver-Burk double reciprocal plot and were found to be 0.5 mM, 10 mM/s, 1.30 U mg−1, and 2.33 U mg−1 mM−1, respectively. This information would be helpful in understanding the biophysical and biochemical characteristics of extracellular α-galactosidase from other microbial sources.

  12. Biomonitoring of genotoxic risk in radar facility workers: comparison of the comet assay with micronucleus assay and chromatid breakage assay

    International Nuclear Information System (INIS)

    Genotoxic risks of occupational exposure in a radar facility were evaluated by using alkaline comet assay, micronucleus assay and chromatid breakage assay on peripheral blood leukocytes in exposed subjects and corresponding controls. Results show that occupational exposure to microwave radiation correlates with an increase of genome damage in somatic cells. The levels of DNA damage in exposed subjects determined by using alkaline comet assay were increased compared to control and showed interindividual variations. Incidence of micronuclei was also significantly increased compared to baseline control values. After short exposure of cultured lymphocytes to bleomycin, cells of occupationally exposed subjects responded with high numbers of chromatid breaks. Although the level of chromosome damage generated by bleomycin varied greatly between individuals, in exposed subjects a significantly elevated number of chromatid breaks was observed. Our results support data reported in literature indicating that microwave radiation represents a potential DNA-damaging hazard. Alkaline comet assay is confirmed as a sensitive and highly reproducible technique for detection of primary DNA damage inflicted in somatic cells. Micronucleus assay was confirmed as reliable bio-markers of effect and chromatid breakage assay as sensitive bio-marker of individual cancer susceptibility. The results obtained also confirm the necessity to improve measures and to perform accurate health surveillance of individuals occupationally exposed to microwave radiation

  13. Improved benzodiazepine radioreceptor assay using the MultiScreen (R) Assay System

    NARCIS (Netherlands)

    Janssen, MJ; Ensing, K; de Zeeuw, RA

    1999-01-01

    In this article, an improved benzodiazepine radioreceptor assay is described, which allows substantial reduction in assay time, The filtration in this method was performed by using the MultiScreen(R) Assay System. The latter consists of a 96-well plate with glass fibre filters sealed at the bottom,

  14. A biochemical marker panel in MRI-proven hyperacute ischemic stroke-a prospective study

    Directory of Open Access Journals (Sweden)

    Knauer Carolin

    2012-03-01

    Full Text Available Abstract Background Computer tomography (CT is still the fastest and most robust technique to rule out ICH in acute stroke. However CT-sensitivity for detection of ischemic stroke in the hyperacute phase is still relatively low. Moreover the validity of pure clinical judgment is diminished by several stroke imitating diseases (mimics. The "Triage® Stroke Panel", a biochemical multimarker assay, detects Brain Natriuretic Peptide (BNP, D-Dimers (DD, Matrix-Metalloproteinase-9 (MMP-9, and S100B protein and promptly generates a Multimarkerindex of these values (MMX. This index has been licensed for diagnostic purposes as it might increase the validity of the clinical diagnosis to differentiate between stroke imitating diseases and true ischemic strokes. Our aim was to prove whether the panel is a reliable indicating device for the diagnosis of ischemic stroke in a time window of 6 h to fasten the pre- and intrahospital pathway to fibrinolysis. Methods We investigated all consecutive patients admitted to our stroke unit during a time period of 5 months. Only patients with clinical investigation, blood sample collection and MRI within six hours from symptom onset were included. Values of biochemical markers were analyzed according to the results of diffusion weighted MR-imaging. In addition MMX-values in ischemic strokes were correlated with the TOAST-criteria. For statistical analysis the SAS Analyst software was used. Correlation coefficients were analyzed and comparison tests for two or more groups were performed. Statistical significance was assumed in case of p Results In total 174 patients were included into this study (n = 100 strokes, n = 49 mimics, n = 25 transitoric ischemic attacks. In patients with ischemic strokes the mean NIHSS was 7.6 ± 6.2, while the mean DWI-lesion volume was 20.6 ml (range 186.9 to 4.2 ml. According to the MMX or the individual markers there was no statistically significant difference between the group of ischemic

  15. Serum Bactericidal Assay: New Role in Salmonella Detection.

    Science.gov (United States)

    Chen, Yu; Wu, Da; Sun, Min; Deng, Mingjun; Cui, Shuhua; Liang, Chengzhu; Geng, Juan; Sun, Tao; Long, Ling; Xiao, Xizhi

    2016-01-01

    While inspecting animal feed for Salmonella contamination, we routinely observed bacterial colonies on selective agars that were similar in appearance to those formed by Salmonella. These were identified as Citrobacter freundii, Proteus mirabilis, and Serratia fonticola using biochemical and serological techniques. Because the presence of these bacterial species confounds identification of Salmonella, we refer to them as "interference bacteria." Polyvalent antisera against these interference bacteria were prepared by immunizing rabbits with a mixture of all three organisms. To minimize or eliminate interference by these bacteria, the polyvalent antisera were introduced between the steps of selective enrichment and Salmonella-selective plating. The antisera raised against the interference bacteria, when combined with neonatal rabbit complement, exhibited specific bactericidal activity against C. freundii, P. mirabilis, and S. fonticola. The respective serum bactericidal assay titers were 2(9), 2(8), and 2(10). In selective broth, polyvalent antisera could also kill the target bacterial cells effectively. We tested 526 samples (186 white fishmeal, 97 red fishmeal, and 243 cattle bone powder) using the polyvalent antisera and found that the rates of contamination of each species of the three respective foods decreased by 58.8, 100, and 83%. Our data indicates that polyvalent sera against C. freundii, P. mirabilis, and S. fonticola can be used as inhibitors to increase the accuracy of Salmonella detection. PMID:26822285

  16. Amelioration of radiation induced DNA damage and biochemical alterations by Punica Granatum (L) extracts and synthetic ellagic acid in Swiss albino mice

    International Nuclear Information System (INIS)

    Radiation therapy has been used in cancer treatment for many decades; Although effective in killing tumor cells, ROS produced in radiotherapy threaten the integrity and survival of surrounding normal cells. ROS are scavenged by radioprotectors before they can interact with biochemical molecules, thus reducing harmful effects of radiation. The pomegranate, Punica granatum L., an ancient, mystical, and highly distinctive fruit, is the predominant member of the Punicaceae family. It is used in several systems of medicine for a variety of ailments. The objective of the present study was to investigate the protective effects of ethanolic extracts of pomegranate whole fruit (EPWF) and seeds (EPS) and Synthetic Ellagic acid (EA) against Electron Beam Radiation (EBR) induced DNA damage and biochemical alterations in Swiss Albino mice. The extracts and synthetic compound were assessed for its radical scavenging property by DPPH radical scavenging and Ferric Reducing Antioxidant Power assays. The animals were treated with 200 mg/kg body wt. of pomegranate extracts and Ellagic acid for 15 days before exposure to 6 Gy of EBR. Radiation induced DNA damage was assessed by comet assay in the peripheral blood lymphocytes of mice. The biochemical estimations were carried out in the serum and RBC lysate of the animals. The plant extracts and synthetic compound exhibited good radical scavenging and reducing properties.The pretreated animals before irradiation caused a reduction in the comet length, olive tail moment, % DNA in tail when compared to irradiated group. The biochemical parameters such as lipid peroxidation was significantly depleted in the treated groups when compared to irradiated group followed by significant elevation in reduced glutathione. Our findings indicate the ameliorating effects of pomegranate extracts and synthetic ellagic acid on radiation induced DNA damage and biochemical changes in mice may be due to its free radical scavenging and increased antioxidant

  17. Determining the gross biochemical composition of cells and tissue with Raman spectrosocpy

    Science.gov (United States)

    Mourant, Judith R.; Dominguez, Jorge; Carpenter, Susan; Powers, Tamara M.; Guerra, Anabel; Short, Kurt W.; Kunapareddy, Nagapratima; Freyer, James P.

    2006-02-01

    The biochemical composition of mammalian cells has been estimated by Raman spectroscopy and the results compared with other biochemical methods. The Raman spectroscopy estimates were performed by fitting measured Raman and infrared spectra of dense cell suspensions to a linear combination of basis components (RNA, DNA, protein, lipid, glycoen). The Raman spectroscopy results are compared to biochemical analyses performed by extraction and quantfication of the biochemical components. Both absolute and relative measurements of biochemical composition are compared. Both the Raman and biochemical results indicate that there are signficant differences in gross biochemical composition dependent on growth stage and tumorigneicity.

  18. Enzyme-linked immunoassay for plasma-free metanephrines in the biochemical diagnosis of phaeochromocytoma in adults is not ideal.

    LENUS (Irish Health Repository)

    2012-02-01

    Abstract Background: The aim of the study was to define the analytical and diagnostic performance of the Labor Diagnostica Nord (LDN) 2-Met plasma ELISA assay for fractionated plasma metanephrines in the biochemical diagnosis of phaeochromocytoma. Methods: The stated manufacturer\\'s performance characteristics were assessed. Clinical utility was evaluated against liquid chromatography tandem mass spectrometry (LC-MS\\/MS) using bias, sensitivity and specificity outcomes. Samples (n=73) were collected from patients in whom phaeochromocytoma had been excluded (n=60) based on low probability of disease, repeat negative testing for urinary fractionated catecholamines and metanephrines, lack of radiological and histological evidence of a tumour and from a group (n=13) in whom the tumour had been histologically confirmed. Blood collected into k(2)EDTA tubes was processed within 30 min. Separated plasma was aliquoted (x2) and frozen at -40 degrees C prior to analyses. One aliquot was analysed for plasma metanephrines using the LDN 2-Met ELISA and the other by LC-MS\\/MS. Results: The mean bias of -32% for normetanephrine (ELISA) when compared to the reference method (LC-MS\\/MS) makes under-diagnosis of phaeochromocytoma likely. The sensitivity of the assay (100%) was equal to the reference method, but specificity (88.3%) lower than the reference method (95%), making it less than optimum for the biochemical diagnosis of phaeochromocytoma. Conclusions: Plasma-free metanephrines as measured by Labor Diagnostica Nord (LDN) 2-Met ELISA do not display test characteristics that would support their introduction or continuation as part of a screening protocol for the biochemical detection of phaeochromocytoma unless the calibration problem identified is corrected and other more accurate and analytically specific methods remain unavailable.

  19. Ondansetron attenuates co-morbid depression and anxiety associated with obesity by inhibiting the biochemical alterations and improving serotonergic neurotransmission.

    Science.gov (United States)

    Kurhe, Yeshwant; Mahesh, Radhakrishnan

    2015-09-01

    In our earlier study we reported the antidepressant activity of ondansetron in obese mice. The present study investigates the effect of ondansetron on depression and anxiety associated with obesity in experimental mice with biochemical evidences. Male Swiss albino mice were fed with high fat diet (HFD) for 14weeks to induce obesity. Then the subsequent treatment with ondansetron (0.5 and 1mg/kg, p.o.), classical antidepressant escitalopram (ESC) (10mg/kg, p.o.) and vehicle (distilled water 10ml/kg, p.o.) was given once daily for 28days. Behavioral assay for depression including sucrose preference test, forced swim test (FST) and anxiety such as light dark test (LDT) and hole board test (HBT) were performed in obese mice. Furthermore, in biochemical estimations oral glucose tolerance test (OGTT), plasma leptin, insulin, corticosterone, brain oxidative stress marker malonaldehyde (MDA), antioxidant reduced glutathione (GSH) and serotonin assays were performed. Results indicated that HFD fed obese mice showed severe depressive and anxiety-like behaviors. Chronic treatment with ondansetron inhibited the co-morbid depression and anxiety in obese mice by increasing sucrose consumption in sucrose preference test and reducing the immobility time in FST, increasing time and transitions of light chamber in LDT, improving head dip and crossing scores in HBT compared to HFD control mice. Ondansetron in obese mice inhibited glucose sensitivity in OGTT, improved plasma leptin and insulin sensitivity, reversed hypothalamic pituitary adrenal (HPA) axis hyperactivity by reducing the corticosterone concentration, restored brain pro-oxidant/anti-oxidant balance by inhibiting MDA and elevating GSH concentrations and facilitated serotonergic neurotransmission. In conclusion, ondansetron reversed the co-morbid depression and anxiety associated with obesity in experimental mice by attenuating the behavioral and biochemical abnormalities. PMID:26188166

  20. Biochemical characterisation during seed development of oil palm (Elaeis guineensis).

    Science.gov (United States)

    Kok, Sau-Yee; Namasivayam, Parameswari; Ee, Gwendoline Cheng-Lian; Ong-Abdullah, Meilina

    2013-07-01

    Developmental biochemical information is a vital base for the elucidation of seed physiology and metabolism. However, no data regarding the biochemical profile of oil palm (Elaeis guineensis Jacq.) seed development has been reported thus far. In this study, the biochemical changes in the developing oil palm seed were investigated to study their developmental pattern. The biochemical composition found in the seed differed significantly among the developmental stages. During early seed development, the water, hexose (glucose and fructose), calcium and manganese contents were present in significantly high levels compared to the late developmental stage. Remarkable changes in the biochemical composition were observed at 10 weeks after anthesis (WAA): the dry weight and sucrose content increased significantly, whereas the water content and hexose content declined. The switch from a high to low hexose/sucrose ratio could be used to identify the onset of the maturation phase. At the late stage, dramatic water loss occurred, whereas the content of storage reserves increased progressively. Lauric acid was the most abundant fatty acid found in oil palm seed starting from 10 WAA. PMID:23575803

  1. Microstereolithography and its application to biochemical IC chip

    Science.gov (United States)

    Ikuta, Koji; Maruo, Shoji; Hasegawa, Tadahiro; Adachi, Takao

    2001-06-01

    The world's first micro stereo lithography, named IH process, was proposed and developed by the speaker in 1992. By now, several types of micro stereo lithography systems have been developed. Three-dimensional resolution of solidification has reached to 0.2 micron at present. These 3D micro fabrication processes using UV curable polymer gave a big impact on not only MEMS but also optics. The latest version of IH process enables us to make a movable micro mechanism without assemble process or sacrificial layer technique often used in silicon process. It is well known that the IH process is the mother of two-photon micro stereo lithography and its applications. Recently new micro chemical device named Biochemical IC Chip was proposed and developed by the speaker. This chip is based on the module IC chip-set like today's TTL family. IH process enable to make the biochemical IC including real three-dimensional micro fluid channels. Various kinds of Biochemical IC chips such as micro pump, switching valve, reactor, concentrator and detector have already been fabricated successfully. Basic performance of micro chemical devices constructed by the biochemical IC chips were demonstrated. The biochemical IC chips will open new bioscience and medicine based on innovative technology.

  2. Cell-Based Assay Design for High-Content Screening of Drug Candidates.

    Science.gov (United States)

    Nierode, Gregory; Kwon, Paul S; Dordick, Jonathan S; Kwon, Seok-Joon

    2016-02-01

    To reduce attrition in drug development, it is crucial to consider the development and implementation of translational phenotypic assays as well as decipher diverse molecular mechanisms of action for new molecular entities. High-throughput fluorescence and confocal microscopes with advanced analysis software have simplified the simultaneous identification and quantification of various cellular processes through what is now referred to as highcontent screening (HCS). HCS permits automated identification of modifiers of accessible and biologically relevant targets and can thus be used to detect gene interactions or identify toxic pathways of drug candidates to improve drug discovery and development processes. In this review, we summarize several HCS-compatible, biochemical, and molecular biology-driven assays, including immunohistochemistry, RNAi, reporter gene assay, CRISPR-Cas9 system, and protein-protein interactions to assess a variety of cellular processes, including proliferation, morphological changes, protein expression, localization, post-translational modifications, and protein-protein interactions. These cell-based assay methods can be applied to not only 2D cell culture but also 3D cell culture systems in a high-throughput manner. PMID:26428732

  3. Establishment of a High-Throughput Assay to Monitor Influenza A Virus RNA Transcription and Replication.

    Directory of Open Access Journals (Sweden)

    Zhen Wang

    Full Text Available Influenza A virus (IAV poses significant threats to public health because of the recent emergence of highly pathogenic strains and wide-spread resistance to available anti-influenza drugs. Therefore, new antiviral targets and new drugs to fight influenza virus infections are needed. Although IAV RNA transcription/replication represents a promising target for antiviral drug development, no assay ideal for high-throughput screening (HTS application is currently available to identify inhibitors targeting these processes. In this work, we developed a novel HTS assay to analyze the transcription and replication of IAV RNA using an A549 cell line stably expressing IAV RNA-dependent RNA polymerase (RdRp complex, NP and a viral mini-genomic RNA. Both secreted Gaussia luciferase (Gluc and blasticidin resistance gene (Bsd were encoded in the viral minigenome and expressed under the control of IAV RdRp. Gluc serves as a reporter to monitor the activity of IAV RdRp, and Bsd is used to maintain the expression of all foreign genes. Biochemical studies and the statistical analysis presented herein demonstrate the high specificity, sensitivity and reproducibility of the assay. This work provides an ideal HTS assay for the identification of inhibitors targeting the function of IAV RdRp and a convenient reporting system for mechanism study of IAV RNA transcription / replication.

  4. Gelatin degradation assay reveals MMP-9 inhibitors and function of O-glycosylated domain

    Institute of Scientific and Technical Information of China (English)

    Jennifer; Vandooren; Nathalie; Geurts; Erik; Martens; Philippe; E; Van; den; Steen; Steven; De; Jonghe; Piet; Herdewijn; Ghislain; Opdenakker

    2011-01-01

    AIM: To establish a novel, sensitive and high-throughput gelatinolytic assay to define new inhibitors and compare domain deletion mutants of gelatinase B/matrix metalloproteinase (MMP)-9. METHODS: Fluorogenic Dye-quenched (DQ)TM-gelatin was used as a substrate and biochemical parameters (substrate and enzyme concentrations, DMSO solvent concentrations) were optimized to establish a highthroughput assay system. Various small-sized libraries (ChemDiv, InterBioScreen and ChemBridge) of hetero-cyclic, drug-like substances were tested and compared with prototypic inhibitors. RESULTS: First, we designed a test system with gelatin as a natural substrate. Second, the assay was validated by selecting a novel pyrimidine-2,4,6-trione (barbitu- rate) inhibitor. Third, and in line with present structural data on collagenolysis, it was found that deletion of the O-glycosylated region significantly decreased gelatinolytic activity (kcat/kM ± 40% less than full-length MMP-9). CONCLUSION: The DQTM-gelatin assay is useful in high-throughput drug screening and exosite targeting. We demonstrate that flexibility between the catalytic and hemopexin domain is functionally critical for gelatinolysis.

  5. Platelet hexosaminidase a enzyme assay effectively detects carriers missed by targeted DNA mutation analysis.

    Science.gov (United States)

    Nakagawa, Sachiko; Zhan, Jie; Sun, Wei; Ferreira, Jose Carlos; Keiles, Steven; Hambuch, Tina; Kammesheidt, Anja; Mark, Brian L; Schneider, Adele; Gross, Susan; Schreiber-Agus, Nicole

    2012-01-01

    Biochemical testing of hexosaminidase A (HexA) enzyme activity has been available for decades and has the ability to detect almost all Tay-Sachs disease (TSD) carriers, irrespective of ethnic background. This is increasingly important, as the gene pool of those who identify as Ashkenazi Jewish is diversifying. Here we describe the analysis of a cohort of 4,325 individuals arising from large carrier screening programs and tested by the serum and/or platelet HexA enzyme assays and by targeted DNA mutation analysis. Our results continue to support the platelet assay as a highly effective method for TSD carrier screening, with a low inconclusive rate and the ability to detect possible disease-causing mutation carriers that would have been missed by targeted DNA mutation analysis. Sequence analysis performed on one such platelet assay carrier, who had one non-Ashkenazi Jewish parent, identified the amino acid change Thr259Ala (A775G). Based on crystallographic modeling, this change is predicted to be deleterious, as threonine 259 is positioned proximal to the HexA alpha subunit active site and helps to stabilize key residues therein. Accordingly, if individuals are screened for TSD in broad-based programs by targeted molecular testing alone, they must be made aware that there is a more sensitive and inexpensive test available that can identify additional carriers. Alternatively, the enzyme assays can be offered as a first tier test, especially when screening individuals of mixed or non-Jewish ancestry. PMID:23430931

  6. Radioactive wastes assay technique and equipment

    International Nuclear Information System (INIS)

    The waste inventory records such as the activities and radio- nuclides contained in the waste packages are to be submitted with the radioactive wastes packages for the final disposal. The nearly around 10,000 drums of waste stocked in KAERI now should be assayed for the preparation of the waste inventory records too. For the successive execution of the waste assay, the investigation into the present waste assay techniques and equipment are to be taken first. Also the installation of the waste assay equipment through the comprehensive design, manufacturing and procurement should be proceeded timely. As the characteristics of the KAERI-stocked wastes are very different from that of the nuclear power plant and those have no regular waste streams, the application of the in-direct waste assay method using the scaling factors are not effective for the KAERI-generated wastes. Considering for the versal conveniency including the accuracy over the wide range of waste forms and the combination of assay time and sensitivity, the TGS(Tomographic Gamma Scanner) is appropriate as for the KAERI -generated radioactive waste assay equipment

  7. Mobile non-destructive assay system

    International Nuclear Information System (INIS)

    A mobile system for non-destructive assay (NDA), developed at the Los Alamos National Laboratory, provides accurate and sensitive measurements for transuranic (TRU) isotopes contained in 208-iota drums of miscellaneous nuclear wastes. The NDA unit consists of four major subsystems: an assay chamber, counting and digital electronics, data acquisition, and a neutron generator. It performs both active and passive neutron waste measurements. The former determines the amount of fissile isotopes at a sensitivity level of 1 mg plutonium. The latter determines spontaneous fission and α,n) isotopes at a comparable level. A complete assay consists of sequential active and passive measurements. The assay measurement and other supporting data are incorporated in a commercial spreadsheet program (Lotus 1,2,3) for further analysis, which includes various matrix corrections and a determination of whether or not the drum exceeds the 100-nCi/g threshold for TRU wastes. Field tests have been performed on three separate occasions, accomplishing more than 1800 waste drum assays. These waste drum assays are discussed, especially those comparing passive and active neutron measurements with independent segmented gamma scan assays. Results obtained with a set of 15 drums containing plutonium prepared from standards and actual hot waste matrices are also reviewed

  8. Simple UV spectrophotometric assay of Mefenamic acid

    Directory of Open Access Journals (Sweden)

    Dr. Safila Naveed

    2014-07-01

    Full Text Available Mefenamic acid belongs to non-steroidal antiinflammatory drugs (NSAID.. It is being used widely for the treatment of analgesia. It is also used as antirheumatic and antipyretic drug. Our aim of study is to develop a efficient least time consuming and simple spectrophotometric method for the assay of mefenamic acid. Comparision of assay of three different brands of mefenamic acid (mefnac,ponstan,dolar available in public medical store of Karachi, Pakistan has also been done. The assay is based on the ultraviolet UV absorbance maxima at about 288nm wavelength of mefenamic acid, water is used as solvent. A sample of drug was dissolved in water to produce a solution containing mefenamic acid. Similarly, a sample of ground tablets of different brand were dissolved in water and various dilutions were made. The absorbance of sample preparation was measured at 288nm against the solvent blank and the assay was determined by comparing with the absorbance of available brand. Our results reveals that among all the three brands of mefenamic acid (mefnac,ponstan,dolar rosulin and rovista shows highest percentage assay 107.5%. xplended and rosubar shows percent assay of 106.25% and 103.75% while rovactor shows lowest value for percentage assay 98.75%.

  9. Cytotoxicity and genotoxicity of Agaricus blazei methanolic extract fractions assessed using gene and chromosomal mutation assays

    Directory of Open Access Journals (Sweden)

    Marilanda Ferreira Bellini

    2008-01-01

    Full Text Available Functional food investigations have demonstrated the presence of substances that could be beneficial to human health when consumed. However, the toxic effects of some substances contained in foods have been determined. Reported medicinal and nutritive properties have led to the extensive commercialization of the basidiomycete fungi Agaricus blazei Murrill (sensu Heinemann, also known as Agaricus brasiliensis Wasser et al., Agaricus subrufescens Peck or the Brazilian medical mushroom (BMM. Different methanolic extract fractions (ME of this mushroom were submitted to the cytokinesis-block micronucleus (CBMN clastogenic assay and the hypoxanthine-guanine phosphoribosyl transferase locus (HGPRT assay for gene mutation, both using Chinese hamster ovary cells clone K1 (CHO-K1. The results suggest that all the fractions tested possess cytotoxic and mutagenic potential but no clastogenic effects. Further information is needed on the biochemical components of the A. blazei methanol fractions to identify any substances with cytotoxic and/or mutagenicity potential. These findings indicate that A. blazei methanolic extract should not be used due to their genotoxicity and care should be taken in the use of A. blazei by the general population until further biochemical characterization of this fungi is completed.

  10. Determination of cell survival after irradiation via clonogenic assay versus multiple MTT Assay - A comparative study

    International Nuclear Information System (INIS)

    For studying proliferation and determination of survival of cancer cells after irradiation, the multiple MTT assay, based on the reduction of a yellow water soluble tetrazolium salt to a purple water insoluble formazan dye by living cells was modified from a single-point towards a proliferation assay. This assay can be performed with a large number of samples in short time using multi-well-plates, assays can be performed semi-automatically with a microplate reader. Survival, the calculated parameter in this assay, is determined mathematically. Exponential growth in both control and irradiated groups was proven as the underlying basis of the applicability of the multiple MTT assay. The equivalence to a clonogenic survival assay with its disadvantages such as time consumption was proven in two setups including plating of cells before and after irradiation. Three cell lines (A 549, LN 229 and F 98) were included in the experiment to study its principal and general applicability

  11. Environmental herbicides and mycotoxin by inmunoraciochemical assay

    International Nuclear Information System (INIS)

    Immunochemical assays based on antigen antibody recognition, are at present very attractive analytical tools for determination of molecules present in different matrixes.Due to its specificity, sensitivity and easy application, the Immuno radiochemical assays have been adopted by international agencies for control procedures of environmental impact analytes. Optimization conditions for two contaminants, aflatoxin-B1 (AfB1, bacterial myco toxin from Aspergillus flavus) in dry food and atrazine (Atr, chloro-derivative triazine herbicides) in milk and water, by immunoradiometric assays based on the use of polyclonal antibodies for the mycotoxins and specific monoclonal antibody for the triazine derivatives, are presented.Liquid Chromatography is used as reference

  12. Radioreceptor assay of human growth hormone

    International Nuclear Information System (INIS)

    A radioreceptor assay for human growth hormone (hGH) was developed. The receptor preparation was 25,000g pellet from the livers of pregnant rabbits. Iodination of GH with 125I was preformed by the methods of Lactoperoxidase and Iodogen. The sensitivity of assay was 0.67 ± 0.11 ng/ml serum. Serum hGH levels in 72 cases of normal subjects, 102 cases of acromegaly were measured by radioreceptor assay (RRA), and the results were compared with those obtained by radioimmunoassay (RIA)

  13. Passive neutron assay of irradiated nuclear fuels

    International Nuclear Information System (INIS)

    Passive neutron assay of irradiated nuclear fuel has been investigated by calculations and experiments as a simple, complementary technique to the gamma assay. From the calculations it is found that the neutron emission arises mainly from the curium isotopes, the neutrons exhibit very good penetrability of the assemblies, and the neutron multiplication is not affected by the burnup. From the experiments on BWR and PWR assemblies, it is found that the neutron emission rate is proportional to burnup raised to 3.4 power. Recent investigations indicate that the passive neutron assay is a simple and useful technique to determine the consistency of burnups between assemblies. 10 refs

  14. Passive neutron assay of irradiated nuclear fuels

    International Nuclear Information System (INIS)

    Passive neutron assay of irradiated nuclear fuel has been investigated by calculations and experiments as a simple, complementary technique to the gamma assay. From the calculations it was found that the neutron emission arises mainly from the curium isotopes, the neutrons exhibit very good penetrability of the assemblies, and the neutron multiplication is not affected by the burnup. From the experiments on BWR and PWR assemblies, the neutron emission rate is proportional to burnup raised to 3.4 power. The investigations indicate that the passive neutron assay is a simple and useful technique to determine the consistency of burnups between assemblies

  15. Nondestructive assay measurements applied to reprocessing plants

    International Nuclear Information System (INIS)

    Nondestructive assay for reprocessing plants relies on passive gamma-ray spectrometry for plutonium isotopic and plutonium mass values of medium-to-low-density samples and holdup deposits; on active x-ray fluorescence and densitometry techniques for uranium and plutonium concentrations in solutions; on calorimetry for plutonium mass in product; and passive neutron techniques for plutonium mass in spent fuel, product, and waste. This paper will describe the radiation-based nondestructive assay techniques used to perform materials accounting measurements. The paper will also discuss nondestructive assay measurements used in inspections of reprocessing plants

  16. 尿道及其他显色培养基快速分离鉴定常见泌尿道感染致病菌的临床应用%Urethra and other chromogenic medium fast isolation and identification of common urinary tract infection pathogens in clinical application

    Institute of Scientific and Technical Information of China (English)

    翁杏华; 徐涛; 陈瑞湖; 关尚; 陈玉莲

    2014-01-01

    Objective Urethra and other chromogenic medium fast identification of common urinary tract pathogens isolated in order to avoid errors caused by mixed bacteria identification and susceptibility results. Methods Accordance with the "national clinical laboratory Procedures"3rd edition urine culture methods used;specimens inoculated directly on blood agar and urethra chromogenic media for culture and identification plates,etc. with the French bioMérieux atbexpression automatic identification system for identification of bacteria and / or verification. Results Major urinary tract infection escherichia coli bacteria 49. 1%,klebsiella pneumoniae 8. 9%,proteus 10. 8%. Conclu-sion Proven compliance rate of 90% to 100%. Urethral chromogenic medium can quickly and easily isolated and identified common urina-ry tract pathogens,saving the cost of reagents,suitable for all basic hospital application.%目的:总结尿道及其他显色培养基快速分离鉴定常见泌尿道致病菌以避免混合菌引起错误的鉴定及药敏结果。方法:按照《全国临床检验操作规程》第3版尿培养的方法;标本直接接种在血平板及尿道显色培养基等平板上进行培养鉴定,用法国生物梅里埃公司ATBExpression自动细菌鉴定仪进行鉴定和/或验证。结果:主要泌尿道感染菌49.1%为大肠埃希菌,8.9%为肺炎克雷伯菌,10.8%为变形杆菌。结论:经验证明总符合率为96%,尿道显色培养基能快速、方便分离鉴定常见泌尿道致病菌,节约试剂成本,适合各基层医院推广应用。

  17. Live-cell luciferase assay of drug resistant cells

    OpenAIRE

    sprotocols

    2015-01-01

    To date, multiplexing cell-based assay is essential for high-throughput screening of molecular targets. Measuring multiple parameters of a single sample increases consistency and decrease time and cost of assay. Functional assay of living cell is useful as a first step of multiplexing assay, because live-cell assay allows following second assay using cell lysate or stained cell. However, live-cell assay of drug resistant cells that are highly activated of drug efflux mechanisms is sometimes u...

  18. Carbamates toxicity in farmers and its assesment through biochemical parameters

    International Nuclear Information System (INIS)

    Prevalent environmental toxicity of various chemical group of pesticides and their effects leading towards increasing morbidity and mortality in the farmers is of great concerned. In this situation the biochemical biomarkers are regarded as meaningful tools for monitoring toxic end points. This work was aimed to assess the toxic impacts of carbamates through some biochemical parameters and useful validity of these biomarkers was also observed. Present results reveal inhibition of cholinesterase activity by 46% whereas bilirubin, urea and creatinine levels in serum were increased and sugar values was decreased at highly significant level (p<0.001). Urine urobilinogen concentration found raised significantly at high level (p<0.001) while protein, urea creatinine and sugar values in urine of the farmers seen non-significant. This study concluded that the selected biochemical parameters can be used as biomarkers to assess the significant toxic effects in the exposed populations. (author)

  19. Hematologic and plasma biochemical values of hyacinth macaws (Anodorhynchus hyacinthinus).

    Science.gov (United States)

    Kolesnikovas, Cristiane K M; Niemeyer, Claudia; Teixeira, Rodrigo H F; Nunes, Adauto L V; Rameh-de-Albuquerque, Luciana C; Sant'Anna, Sávio S; Catão-Dias, José L

    2012-09-01

    The hyacinth macaw (Anodorhyncus hyacinthinus), considered the largest psittacine bird species in the world, is an endangered species, with a remaining population of approximately 6500 birds in the wild. To establish hematologic and plasma biochemical reference ranges and to verify differences related to sex, samples from 29 hyacinth macaws (14 males, 15 females) were obtained from birds apprehended from illegal wildlife trade and subsequently housed at the Sorocaba Zoo, Brazil. No significant differences in hematologic or plasma biochemical values were found between females and males. Compared with published reference values, differences were found in mean concentrations of total red blood cell count, corpuscular volume, corpuscular hemoglobin level, total white blood cell count, aspartate aminotransferase level, creatine kinase concentration, alkaline phosphatase concentration, and phosphorus level. Baseline hematologic and plasma biochemical ranges were established, which may be useful as reference values for clinicians working with this endangered species in captivity or rehabilitation centers. PMID:23156973

  20. Hematologic and plasma biochemical values of Spix's macaws (Cyanopsitta spixii).

    Science.gov (United States)

    Foldenauer, Ulrike; Borjal, Raffy Jim; Deb, Amrita; Arif, Abdi; Taha, Abid Sharif; Watson, Ryan William; Steinmetz, Hanspeter; Bürkle, Marcellus; Hammer, Sven

    2007-12-01

    The Spix's macaw (Cyanopsitta spixii) is considered the world's most endangered parrot, with the last wild bird disappearing in 2001 and only 74 birds in captivity. To establish hematologic and plasma biochemical reference ranges and to look for differences relative to sex, age, and season, we obtained blood samples from 46 captive Spix's macaws (23 male, 23 female) housed in aviaries at the Al Wabra Wildlife Preservation in the State of Qatar. No significant differences in hematologic or plasma biochemical values were found between females and males. Adult and juvenile birds differed in mean concentrations of glucose, total protein, amylase, cholesterol, and phosphorus; in percentages of heterophils and lymphocytes; and in the absolute lymphocyte count. Total protein, cholesterol, and phosphorus concentrations; hematocrit; and heterophil and lymphocyte counts differed significantly by season. Baseline hematologic and plasma biochemical ranges were established, which may be useful as reference values for clinicians working with this highly endangered species. PMID:18351006

  1. Occurrence of bacteria and biochemical markers on public surfaces.

    Science.gov (United States)

    Reynolds, Kelly A; Watt, Pamela M; Boone, Stephanie A; Gerba, Charles P

    2005-06-01

    From 1999-2003, the hygiene of 1061 environmental surfaces from shopping, daycare, and office environments, personal items, and miscellaneous activities (i.e., gymnasiums, airports, movie theaters, restaurants, etc.), in four US cities, was monitored. Samples were analyzed for fecal and total coliform bacteria, protein, and biochemical markers. Biochemical markers, i.e., hemoglobin (blood marker), amylase (mucus, saliva, sweat, and urine marker), and urea (urine and sweat marker) were detected on 3% (26/801); 15% (120/801), and 6% (48/801) of the surfaces, respectively. Protein (general hygiene marker) levels > or = 200 microg/10 cm2 were present on 26% (200/801) of the surfaces tested. Surfaces from children's playground equipment and daycare centers were the most frequently contaminated (biochemical markers on 36%; 15/42 and 46%; 25/54, respectively). Surfaces from the shopping, miscellaneous activities, and office environments were positive for biochemical markers with a frequency of 21% (69/333), 21% (66/308), and 11% (12/105), respectively). Sixty samples were analyzed for biochemical markers and bacteria. Total and fecal coliforms were detected on 20% (12/60) and 7% (4/ 60) of the surfaces, respectively. Half and one-third of the sites positive for biochemical markers were also positive for total and fecal coliforms, respectively. Artificial contamination of public surfaces with an invisible fluorescent tracer showed that contamination from outside surfaces was transferred to 86% (30/ 35) of exposed individual's hands and 82% (29/35) tracked the tracer to their home or personal belongings hours later. Results provide information on the relative hygiene of commonly encountered public surfaces and aid in the identification of priority environments where contaminant occurrence and risk of exposure may be greatest. Children's playground equipment is identified as a priority surface for additional research on the occurrence of and potential exposure to infectious

  2. Competition-based cellular peptide binding assays for 13 prevalent HLA class I alleles using fluorescein-labeled synthetic peptides.

    Science.gov (United States)

    Kessler, Jan H; Mommaas, Bregje; Mutis, Tuna; Huijbers, Ivo; Vissers, Debby; Benckhuijsen, Willemien E; Schreuder, Geziena M Th; Offringa, Rienk; Goulmy, Els; Melief, Cornelis J M; van der Burg, Sjoerd H; Drijfhout, Jan W

    2003-02-01

    We report the development, validation, and application of competition-based peptide binding assays for 13 prevalent human leukocyte antigen (HLA) class I alleles. The assays are based on peptide binding to HLA molecules on living cells carrying the particular allele. Competition for binding between the test peptide of interest and a fluorescein-labeled HLA class I binding peptide is used as read out. The use of cell membrane-bound HLA class I molecules circumvents the need for laborious biochemical purification of these molecules in soluble form. Previously, we have applied this principle for HLA-A2 and HLA-A3. We now describe the assays for HLA-A1, HLA-A11, HLA-A24, HLA-A68, HLA-B7, HLA-B8, HLA-B14, HLA-B35, HLA-B60, HLA-B61, and HLA-B62. Together with HLA-A2 and HLA-A3, these alleles cover more than 95% of the Caucasian population. Several allele-specific parameters were determined for each assay. Using these assays, we identified novel HLA class I high-affinity binding peptides from HIVpol, p53, PRAME, and minor histocompatibility antigen HA-1. Thus these convenient and accurate peptide-binding assays will be useful for the identification of putative cytotoxic T lymphocyte epitopes presented on a diverse array of HLA class I molecules. PMID:12559627

  3. The Development of a Biochemical Profile of Acacia Honey by Identifying Biochemical Determinants of its Quality

    Directory of Open Access Journals (Sweden)

    Liviu Alexandru MARGHITAS

    2010-09-01

    Full Text Available Codex Alimentarius Standard, EU Legislation and National Standards state honey authenticity. Authenticity in respect of production (to prevent adulteration and authenticity in respect of geographical and botanical origin are the two main aspects of general honey authenticity. Quality of honey depends on the plant source, the chemical composition of these plants as well, as on the climatic conditions and soil mineral composition. Romanian acacia (Robinia pseudoacacia honey that came from the most important Transylvanian massif (Valea lui Mihai, Bihor County, Romania was evaluated for authenticity by pollen-analysis, several physico-chemical analyses, including sugar profile and mineral content. As polyphenolic content could be also an important factor for botanical authentification, HPLC-DAD-MS analyses were performed to assess the fingerprint of this important secondary plant metabolite. Statistical data were processed in order to develop a biochemical profile of this type of honey and the main quality categories identification. The results of physico-chemical analysis demonstrated that the tested honey samples could be framed into monofloral type of acacia honeys. The analysis of acacia honeys originating from Valea lui Mihai, Romania, showed that polyphenolic profile (phenolic acids and flavonoids could be used as a complementary method for authenticity determination together with pollen analysis and other physico-chemical analysis.

  4. Physiological and biochemical basis of salmon young ifshes migratory behavior

    Institute of Scientific and Technical Information of China (English)

    Vladimir Ivanovich Martemyanov

    2016-01-01

    The review presents data on structural changes, physiological and biochemical reactions occurring at salmon young fishes during smoltification. It is shown, that young salmon fishes located in fresh water, in the process of smoltification undergo a complex of structural, physiological and biochemical changes directed on preparation of the organism for living in the sea. These changes cause stress reaction which excites young fishes to migrate down the river towards the sea. Measures to improve reproduction of young salmon fishes at fish farms are offered.

  5. Stochastic modeling for the COMET-assay

    OpenAIRE

    Boulesteix, Anne-Laure; Hösel, Volker; Liebscher, Volkmar

    2003-01-01

    We present a stochastic model for single cell gel electrophoresis (COMET-assay) data. Essential is the use of point process structures, renewal theory and reduction to intensity histograms for further data analysis.

  6. ORNL TRU-waste-assay system

    International Nuclear Information System (INIS)

    ORNL has been selected as the demonstration site for a new transuranic neutron assay system developed at the Los Alamos National Laboratory. The major objectives of the cooperative interlaboratory program is to field test, calibrate, and evaluate the neutron interrogation system, to provide a demonstration and training facility for DOE of this sophisticated technology, to reduce the volume of TRU waste stored at ORNL, and to provide positive identification of the radionuclide content of the ORNL TRU waste. In order to meet these objectives, a two-tier assay system utilizing the LANL neutron interrogation assay system and an upgraded gamma-ray drum scanner has been employed. Each assay technique and the results obtained from the examination of authentic ORNL TRU waste are described

  7. Proximity assays for sensitive quantification of proteins

    Directory of Open Access Journals (Sweden)

    Christina Greenwood

    2015-06-01

    Full Text Available Proximity assays are immunohistochemical tools that utilise two or more DNA-tagged aptamers or antibodies binding in close proximity to the same protein or protein complex. Amplification by PCR or isothermal methods and hybridisation of a labelled probe to its DNA target generates a signal that enables sensitive and robust detection of proteins, protein modifications or protein–protein interactions. Assays can be carried out in homogeneous or solid phase formats and in situ assays can visualise single protein molecules or complexes with high spatial accuracy. These properties highlight the potential of proximity assays in research, diagnostic, pharmacological and many other applications that require sensitive, specific and accurate assessments of protein expression.

  8. Safeguards and Non-destructive Assay

    Energy Technology Data Exchange (ETDEWEB)

    Carchon, R.; Bruggeman, M

    2001-04-01

    SCK-CEN's programme on safeguards and non-destructive assay includes: (1) various activities to assure nuclear materials accountancy; (2) contributes to the implementation of Integrated Safeguards measures in Belgium and to assist the IAEA through the Belgian Support Programme; (3) renders services to internal and external customers in the field of safeguards; (4) improves passive neutron coincidence counting techniques for waste assay and safeguards verification measurements by R and D on correlation algorithms implemented via software or dedicated hardware; (5) improves gamma assay techniques for waste assay by implementing advanced scanning techniques and different correlation algorithms; and (6) develops numerical calibration techniques. Major achievements in these areas in 2000 are reported.

  9. A novel parameter in comet assay measurements

    OpenAIRE

    Kirilova Milena; Ivanov Rumen; Miloshev George

    2005-01-01

    Single Cell Gel Electrophoresis (SCGE) or Comet assay is a very sensitive method for assessing damages in DNA on a single cell level. It has found many applications in fields where genotoxic activity could be an issue. In environmental monitoring, health care, food industry Comet assay is used with increasing popularity. For verifying the results obtained by this method many parameters could be monitored. To that end several software packages exist. In the conditions that we are suggesting on...

  10. The comet assay in nanotoxicology research.

    OpenAIRE

    Karlsson, Hanna L

    2010-01-01

    Nanoscale particles can have impressive and useful characteristics, but the same properties may be problematic for human health. From this perspective it is critical to assess the ability of nanoparticles to cause DNA damage. This review focuses on the use of the comet assay in nanotoxicology research. In the alkaline version of the assay, DNA strand breaks and alkali-labile sites are detected and oxidatively damaged DNA can be analyzed using the enzyme formamidopyrimidine glycosylase. The ar...

  11. Passive nondestructive assay of nuclear materials

    International Nuclear Information System (INIS)

    The term nondestructive assay (NDA) is applied to a series of measurement techniques for nuclear fuel materials. The techniques measure radiation induced or emitted spontaneously from the nuclear material; the measurements are nondestructive in that they do not alter the physical or chemical state of the nuclear material. NDA techniques are characterized as passive or active depending on whether they measure radiation from the spontaneous decay of the nuclear material or radiation induced by an external source. This book emphasizes passive NDA techniques, although certain active techniques like gamma-ray absorption densitometry and x-ray fluorescence are discussed here because of their intimate relation to passive assay techniques. The principal NDA techniques are classified as gamma-ray assay, neutron assay, and calorimetry. Gamma-ray assay techniques are treated in Chapters 1--10. Neutron assay techniques are the subject of Chapters 11--17. Chapters 11--13 cover the origin of neutrons, neutron interactions, and neutron detectors. Chapters 14--17 cover the theory and applications of total and coincidence neutron counting. Chapter 18 deals with the assay of irradiated nuclear fuel, which uses both gamma-ray and neutron assay techniques. Chapter 19 covers perimeter monitoring, which uses gamma-ray and neutron detectors of high sensitivity to check that no unauthorized nuclear material crosses a facility boundary. The subject of Chapter 20 is attribute and semiquantitative measurements. The goal of these measurements is a rapid verification of the contents of nuclear material containers to assist physical inventory verifications. Waste and holdup measurements are also treated in this chapter. Chapters 21 and 22 cover calorimetry theory and application, and Chapter 23 is a brief application guide to illustrate which techniques can be used to solve certain measurement problems

  12. Biochemical characterization and molecular dynamic simulation of β-sitosterol as a tubulin-binding anticancer agent.

    Science.gov (United States)

    Mahaddalkar, Tejashree; Suri, Charu; Naik, Pradeep Kumar; Lopus, Manu

    2015-08-01

    Βeta-sitosterol (β-SITO), a phytosterol present in pomegranate, peanut, corn oil, almond, and avocado, has been recognized to offer health benefits and potential clinical uses. β-SITO is orally bioavailable and, as a constituent of edible natural products, is considered to have no undesired side effects. It has also been considered as a potent anticancer agent. However, the molecular mechanism of action of β-SITO as a tubulin-binding anticancer agent and its binding site on tubulin are poorly understood. Using a combination of biochemical analyses and molecular dynamic simulation, we investigated the molecular details of the binding interactions of β-SITO with tubulin. A polymer mass assay comparing the effects of β-SITO and of taxol and vinblastine on tubulin assembly showed that this phytosterol stabilized microtubule assembly in a manner similar to taxol. An 8-anilino-1-naphthalenesulfonic acid assay confirmed the direct interaction of β-SITO with tubulin. Although β-SITO did not show direct binding to the colchicine site on tubulin, it stabilized the colchicine binding. Interestingly, no sulfhydryl groups of tubulin were involved in the binding interaction of β-SITO with tubulin. Based on the results from the biochemical assays, we computationally modeled the binding of β-SITO with tubulin. Using molecular docking followed by molecular dynamic simulations, we found that β-SITO binds tubulin at a novel site (which we call the 'SITO site') adjacent to the colchicine and noscapine sites. Our data suggest that β-SITO is a potent anticancer compound that interferes with microtubule assembly dynamics by binding to a novel site on tubulin. PMID:25912799

  13. Radioimmune assay of human platelet prostaglandin synthetase

    International Nuclear Information System (INIS)

    Normal platelet function depends, in part, on platelet PG synthesis. PG synthetase (cyclo-oxygenase) catalyzes the first step in PG synthesis, the formation of PGH2 from arachidonic acid. Inhibition of the enzyme by ASA results in an abnormality in the platelet release reaction. Patients with pparent congenital abnormalities in the enzyme have been described, and the effects have been referred to as ''aspirin-like'' defects of the platelet function. These patients lack platelet PG synthetase activity, but the actual content of PG synthetase protein in these individuals' platelets is unknown. Therefore an RIA for human platelet PG synthetase would provide new information, useful in assessing the aspirin-like defects of platelet function. An RIA for human platelet PG synthetase is described. The assay utilizes a rabbit antibody directed against the enzyme and [125I]-labelled sheep PG synthetase as antigen. The human platelet enzyme is assayed by its ability to inhibit precipitation of the [125I]antigen. The assay is sensitive to 1 ng of enzyme. By the immune assay, human platelets contain approximately 1200 ng of PG synethetase protein per 1.5 mg of platelet protein (approximately 109 platelets). This content corresponds to 10,000 enzyme molecules per platelet. The assay provides a rapid and convenient assay for the human platelet enzyme, and it can be applied to the assessment of patients with apparent platelet PG synthetase (cyclo-oxygenase) deficiency

  14. An ultrafiltration assay for lysyl oxidase.

    Science.gov (United States)

    Shackleton, D R; Hulmes, D J

    1990-03-01

    A modification of the original microdistillation assay for lysyl oxidase is described in which Amicon C-10 microconcentrators are used to separate, by ultrafiltration, the 3H-labeled products released from a [4,5-3H]-lysine-labeled elastin substrate. Enzyme activity is determined by scintillation counting of the ultrafiltrate, after subtraction of radioactivity released in the presence of beta-aminopropionitrile, a specific inhibitor of the enzyme. Conditions are described which optimize both the sensitivity and the efficient use of substrate. The assay shows linear inhibition of activity in up to 1 M urea; hence, as the enzyme is normally diluted in the assay, samples in 6 M urea can be assayed directly, without prior dialysis, and corrected for partial inhibition. Comparable results are obtained when enzyme activity is assayed by ultrafiltration or microdistillation. The assay is simple and convenient and, by using disposable containers throughout, it eliminates the need for time-consuming decontamination of radioactive glassware. PMID:1971160

  15. Biochemical and structural characterization of polyphosphate kinase 2 from the intracellular pathogen Francisella tularensis.

    Science.gov (United States)

    Batten, Laura E; Parnell, Alice E; Wells, Neil J; Murch, Amber L; Oyston, Petra C F; Roach, Peter L

    2016-01-01

    The metabolism of polyphosphate is important for the virulence of a wide range of pathogenic bacteria and the enzymes of polyphosphate metabolism have been proposed as an anti-bacterial target. In the intracellular pathogen Francisella tularensis, the product of the gene FTT1564 has been identified as a polyphosphate kinase from the polyphosphate kinase 2 (PPK2) family. The isogenic deletion mutant was defective for intracellular growth in macrophages and was attenuated in mice, indicating an important role for polyphosphate in the virulence of Francisella. Herein, we report the biochemical and structural characterization of F. tularensis polyphosphate kinase (FtPPK2) with a view to characterizing the enzyme as a novel target for inhibitors. Using an HPLC-based activity assay, the substrate specificity of FtPPK2 was found to include purine but not pyrimidine nts. The activity was also measured using (31)P-NMR. FtPPK2 has been crystallized and the structure determined to 2.23 Å (1 Å=0.1 nm) resolution. The structure consists of a six-stranded parallel β-sheet surrounded by 12 α-helices, with a high degree of similarity to other members of the PPK2 family and the thymidylate kinase superfamily. Residues proposed to be important for substrate binding and catalysis have been identified in the structure, including a lid-loop and the conserved Walker A and B motifs. The ΔFTT1564 strain showed significantly increased sensitivity to a range of antibiotics in a manner independent of the mode of action of the antibiotic. This combination of biochemical, structural and microbiological data provide a sound foundation for future studies targeting the development of PPK2 small molecule inhibitors. PMID:26582818

  16. The Stereochemistry of Biochemical Molecules: A Subject to Revisit

    Science.gov (United States)

    Centelles, Josep J.; Imperial, Santiago

    2005-01-01

    Although Fischer's convention for stereoisomers is useful for simple molecules, the stereochemistry of complex biochemical molecules is often poorly indicated in textbooks. This article reports on errors in stereochemistry of complex hydrosoluble vitamin B12 molecule. Twenty-five popular biochemistry textbooks were examined for their treatment of…

  17. A coupled mechano-biochemical model for bone adaptation

    Czech Academy of Sciences Publication Activity Database

    Klika, Václav; Pérez, M. A.; García-Aznar, J. M.; Maršík, F.; Doblaré, M.

    2014-01-01

    Roč. 69, 6-7 (2014), s. 1383-1429. ISSN 0303-6812 Institutional support: RVO:61388998 Keywords : mechano-biochemical model * bone remodelling * BMU Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2014 http://link.springer.com/article/10.1007%2Fs00285-013-0736-9

  18. Biochemical Pathways That Are Important for Cotton Fiber Cell Elongation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The regulatory mechanism that controls the sustained cotton fiber cell elongation is gradually being elucidated by coupling genome-wide transcriptome profiling with systematic biochemical and physiological studies.Very long chain fatty acids(VLCFA),H2O2,and several types of plant hormones

  19. Salvage Brachytherapy for Biochemically Recurrent Prostate Cancer following Primary Brachytherapy

    Science.gov (United States)

    Lacy, John M.; Wilson, William A.; Bole, Raevti; Chen, Li; Meigooni, Ali S.; Rowland, Randall G.; Clair, William H. St.

    2016-01-01

    Purpose. In this study, we evaluated our experience with salvage brachytherapy after discovery of biochemical recurrence after a prior brachytherapy procedure. Methods and Materials. From 2001 through 2012 twenty-one patients treated by brachytherapy within University of Kentucky or from outside centers developed biochemical failure and had no evidence of metastases. Computed tomography (CT) scans were evaluated; patients who had an underseeded portion of their prostate were considered for reimplantation. Results. The majority of the patients in this study (61.9%) were low risk and median presalvage PSA was 3.49 (range 17.41–1.68). Mean follow-up was 61 months. At last follow-up after reseeding, 11/21 (52.4%) were free of biochemical recurrence. There was a trend towards decreased freedom from biochemical recurrence in low risk patients (p = 0.12). International Prostate Symptom Scores (IPSS) increased at 3-month follow-up visits but decreased and were equivalent to baseline scores at 18 months. Conclusions. Salvage brachytherapy after primary brachytherapy is possible; however, in our experience the side-effect profile after the second brachytherapy procedure was higher than after the first brachytherapy procedure. In this cohort of patients we demonstrate that approximately 50% oncologic control, low risk patients appear to have better outcomes than others. PMID:27092279

  20. BIOCHEMICAL AND NEUROPATHOLOGICAL ASSESSMENT OF TRIPHENYL PHOSPHITE IN RATS

    Science.gov (United States)

    The putative neurotoxicity of the organophosphorus compound triphenyl phosphite (TPP) was examined in Long Evans, adult male rats. Animals were exposed to two 1.0 ml/kg (1184 mg/kg) injections (sc) of TPP spaced 1 week apart and sampled for biochemical and neuropathological exami...

  1. Integrating Carbon Nanotubes into Microfluidic Chip for Separating Biochemical Compounds

    DEFF Research Database (Denmark)

    Chen, Miaoxiang Max; Mogensen, Klaus Bo; Bøggild, Peter;

    2012-01-01

    We present a new type of device to separate biochemical compounds wherein carbon nanotubes (CNTs) are integrated as chromatographic stationary phase. The CNTs were directly grown on the bottom of microfluidic channels on Si/SiO2 substrates by chemical vapor deposition (CVD). Acetylene was used as...

  2. A MULTILAYER BIOCHEMICAL DRY DEPOSITION MODEL 2. MODEL EVALUATION

    Science.gov (United States)

    The multilayer biochemical dry deposition model (MLBC) described in the accompanying paper was tested against half-hourly eddy correlation data from six field sites under a wide range of climate conditions with various plant types. Modeled CO2, O3, SO2<...

  3. A MULTILAYER BIOCHEMICAL DRY DEPOSITION MODEL 1. MODEL FORMULATION

    Science.gov (United States)

    A multilayer biochemical dry deposition model has been developed based on the NOAA Multilayer Model (MLM) to study gaseous exchanges between the soil, plants, and the atmosphere. Most of the parameterizations and submodels have been updated or replaced. The numerical integration ...

  4. Advances in Biochemical Screening for Phaeochromocytoma using Biogenic Amines

    OpenAIRE

    Whiting, Malcolm J; Doogue, Matthew P

    2009-01-01

    Biochemical testing for phaeochromocytoma is performed in diagnostic laboratories using a variety of tests with plasma, serum or 24-hour urine collections. These tests include catecholamines and their methylated metabolites - the metanephrines, either individually or in combination with their sulfated metabolites. High-performance liquid chromatography (HPLC) continues to be the dominant analytical method for biogenic amine quantitation. Chromatographic techniques are changing, with improveme...

  5. USE OF MUNICIPAL SOLID WASTE LANDFILLS AS BIOCHEMICAL REACTORS

    Science.gov (United States)

    Municipal solid waste (MSW) from the nation is managed predominantly in anitary landfills. ue to the physical, chemical and biological makeup f he aste he landfill acts as a biochemical reactor and degrades the organic matter. urrent practices are to use covers and liners as engi...

  6. Biosensors and bioelectronics on smartphone for portable biochemical detection.

    Science.gov (United States)

    Zhang, Diming; Liu, Qingjun

    2016-01-15

    Smartphone has been widely integrated with sensors, such as test strips, sensor chips, and hand-held detectors, for biochemical detections due to its portability and ubiquitous availability. Utilizing built-in function modules, smartphone is often employed as controller, analyzer, and displayer for rapid, real-time, and point-of-care monitoring, which can significantly simplify design and reduce cost of the detecting systems. This paper presents a review of biosensors and bioelectronics on smartphone for portable biochemical detections. The biosensors and bioelectronics based on smartphone can mainly be classified into biosensors using optics, surface plasmon resonance, electrochemistry, and near-field communication. The developments of these biosensors and bioelectronics on smartphone are reviewed along with typical biochemical detecting cases. Sensor strategies, detector attachments, and coupling methods are highlighted to show designs of the compact, lightweight, and low-cost sensor systems. The performances and advantages of these designs are introduced with their applications in healthcare diagnosis, environment monitoring, and food evaluation. With advances in micro-manufacture, sensor technology, and miniaturized electronics, biosensor and bioelectronic devices on smartphone can be used to perform biochemical detections as common and convenient as electronic tag readout in foreseeable future. PMID:26319170

  7. Biochemical correlates in an animal model of depression

    International Nuclear Information System (INIS)

    A valid animal model of depression was used to explore specific adrenergic receptor differences between rats exhibiting aberrant behavior and control groups. Preliminary experiments revealed a distinct upregulation of hippocampal beta-receptors (as compared to other brain regions) in those animals acquiring a response deficit as a result of exposure to inescapable footshock. Concurrent studies using standard receptor binding techniques showed no large changes in the density of alpha-adrenergic, serotonergic, or dopaminergic receptor densities. This led to the hypothesis that the hippocampal beta-receptor in responses deficient animals could be correlated with the behavioral changes seen after exposure to the aversive stimulus. Normalization of the behavior through the administration of antidepressants could be expected to reverse the biochemical changes if these are related to the mechanism of action of antidepressant drugs. This study makes three important points: (1) there is a relevant biochemical change in the hippocampus of response deficient rats which occurs in parallel to a well-defined behavior, (2) the biochemical and behavioral changes are normalized by antidepressant treatments exhibiting both serotonergic and adrenergic mechanisms of action, and (3) the mode of action of antidepressants in this model is probably a combination of serotonergic and adrenergic influences modulating the hippocampal beta-receptor. These results are discussed in relation to anatomical and biochemical aspects of antidepressant action

  8. Biochemical tests for diagnosis of phaeochromocytoma: urinary versus plasma determinations.

    OpenAIRE

    Plouin, P F; Duclos, J M; Menard, J; Comoy, E; Bohuon, C; Alexandre, J M

    1981-01-01

    Fifteen patients with hypertension due to phaeochromocytoma and 35 controls with essential hypertension were studied to assess the diagnostic value of urinary and plasma biochemical determinations in phaeochromocytoma. In every case of phaeochromocytoma the urinary concentration of vanillylmandelate, metanephrines, or adrenaline plus noradrenaline was diagnostic of the disease irrespective of whether the patient was normotensive or hypertensive at the time. Plasma determinations of adrenaline...

  9. Biochemical Importance of Glycosylation of Plasminogen Activator Inhibitor-1

    DEFF Research Database (Denmark)

    Gils, Ann; Pedersen, Katrine Egelund; Skottrup, Peter;

    2003-01-01

    glycosylation sites could be excluded as explanation for the differential reactivity. The latency transition of non-glycosylated, but not of glycosylated PAI-1, was strongly accelerated by a non-ionic detergent. The different biochemical properties of glycosylated and non-glycosylated PAI-1 depended...

  10. Study on color difference estimation method of medicine biochemical analysis

    Science.gov (United States)

    Wang, Chunhong; Zhou, Yue; Zhao, Hongxia; Sun, Jiashi; Zhou, Fengkun

    2006-01-01

    The biochemical analysis in medicine is an important inspection and diagnosis method in hospital clinic. The biochemical analysis of urine is one important item. The Urine test paper shows corresponding color with different detection project or different illness degree. The color difference between the standard threshold and the test paper color of urine can be used to judge the illness degree, so that further analysis and diagnosis to urine is gotten. The color is a three-dimensional physical variable concerning psychology, while reflectance is one-dimensional variable; therefore, the estimation method of color difference in urine test can have better precision and facility than the conventional test method with one-dimensional reflectance, it can make an accurate diagnose. The digital camera is easy to take an image of urine test paper and is used to carry out the urine biochemical analysis conveniently. On the experiment, the color image of urine test paper is taken by popular color digital camera and saved in the computer which installs a simple color space conversion (RGB -> XYZ -> L *a *b *)and the calculation software. Test sample is graded according to intelligent detection of quantitative color. The images taken every time were saved in computer, and the whole illness process will be monitored. This method can also use in other medicine biochemical analyses that have relation with color. Experiment result shows that this test method is quick and accurate; it can be used in hospital, calibrating organization and family, so its application prospect is extensive.

  11. Model Based Monitoring and Control of Chemical and Biochemical Processes

    DEFF Research Database (Denmark)

    Huusom, Jakob Kjøbsted

    This presentation will give an overview of the work performed at the department of Chemical and Biochemical Engineering related to process control. A research vision is formulated and related to a number of active projects at the department. In more detail a project describing model estimation and...

  12. [Experiments using rats on Kosmos biosatellites: morphologic and biochemical studies].

    Science.gov (United States)

    Il'in, E A; Kaplanskiĭ, A S; Savina, E A

    1989-01-01

    Results of morphological and biochemical investigations of rats flown on Cosmos biosatellites are discussed. It is emphasized that most changes occurring during exposure to microgravity are directly or indirectly related to lower musculoskeletal loads which in turn produce deconditioning of different physiological systems and organism as a whole. It is concluded that this deconditioning is associated with both metabolic and structural changes. PMID:2685464

  13. MATLAB-Based Teaching Modules in Biochemical Engineering

    Science.gov (United States)

    Lee, Kilho; Comolli, Noelle K.; Kelly, William J.; Huang, Zuyi

    2015-01-01

    Mathematical models play an important role in biochemical engineering. For example, the models developed in the field of systems biology have been used to identify drug targets to treat pathogens such as Pseudomonas aeruginosa in biofilms. In addition, competitive binding models for chromatography processes have been developed to predict expanded…

  14. Biochemical and morphological changes in bone marrow mesenchymal stem cells induced by treatment of rats with p-Nonylphenol

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Abnosi

    2015-04-01

    Full Text Available Objective(s:In previous investigations, we have shown para-nonylphenol (p-NP caused significant reduction of proliferation and differentiation of rat bone marrow mesenchymal stem cells (MSCs in vitro. In this study, we first treat the rats with p-NP, then carried out the biochemical and morphological studies on MSCs. Materials and Methods: Proliferation property of cells was evaluated with the help of MTT assay, trypan blue, population doubling number, and colony forming assay. Differentiation property was evaluated with quantitative alizarin red assay, measurement of alkaline phosphatase (ALP activity as well as intracellular calcium content. In addition; morphological study, TUNEL test, activated caspase assay, and comet assay were performed to evaluate the mechanism of the cell death. Results: The results showed significant reduction in the colony-forming-ability and population-doubling-number of extracted cells when compared to control ones. In addition, it was revealed that the p-NP treatment of rats caused significant reduction in nuclear diameter, cytoplasm shrinkage, and induction of caspase-dependent-apoptosis. Also there was significant reduction in ALP activity, intracellular calcium content, and intracellular matrix following osteogenic differentiation. Conclusion: As MSCs are the cellular back up for bone remodeling and repair, we suggest more investigations to be conducted regarding the correlation between the increasing number of patients suffering from osteoporosis and p-NP toxicity. Also, we strongly recommend WHO and local health organization to prevent industries of using p-NP in formulation of industrial products which may cause changes in proliferation and differentiation properties of stem cells.

  15. The Comet Assay: Tails of the (Unexpected. Use of the comet assay in pharmaceutical development.

    Directory of Open Access Journals (Sweden)

    Bas-jan Van Der Leede

    2015-08-01

    Full Text Available In genotoxicity testing of pharmaceuticals the rodent alkaline comet assay is being increasingly used as a second in vivo assay in addition to the in vivo micronucleus assay to mitigate in vitro positive results as recommended by regulatory guidance. In this presentation we want to give insight into the circumstances in vivo comet assay is deployed in a Genetic Toxicology Department of a pharmaceutical company. As the in vivo comet assay is a salvage assay, it means that some events have occurred in an in vitro assay and that the compound (or metabolite responsible for this signal is potentially deselected for further development. More than often the decision to perform an in vivo comet assay is at a very early stage in development and the first time that the compound will be tested in vivo at high/toxic dose levels. As almost no toxicokinetic data and tissue distribution data are available a careful design with maximizes the chances for successful mitigation is necessary. Decisions on acute or repeated dosing need to be made and arrangements for combining the in vivo comet assay with the in vivo micronucleus assay are to be considered. Often synthesis methods need to be scaled up fast to provide the required amount of compound and information on suitable formulations needs to be in place. As exposure data is crucial for interpretation of results, analytical methods need to be brought in place rapidly. An experienced multi skilled and communicative team needs to be available to deploy successfully this kind of assays at an early stage of development. We will present a few scenarios on study conduct and demonstrate how this assay can make a difference for the further development of a new drug.

  16. Thermodynamically consistent Bayesian analysis of closed biochemical reaction systems

    Directory of Open Access Journals (Sweden)

    Goutsias John

    2010-11-01

    Full Text Available Abstract Background Estimating the rate constants of a biochemical reaction system with known stoichiometry from noisy time series measurements of molecular concentrations is an important step for building predictive models of cellular function. Inference techniques currently available in the literature may produce rate constant values that defy necessary constraints imposed by the fundamental laws of thermodynamics. As a result, these techniques may lead to biochemical reaction systems whose concentration dynamics could not possibly occur in nature. Therefore, development of a thermodynamically consistent approach for estimating the rate constants of a biochemical reaction system is highly desirable. Results We introduce a Bayesian analysis approach for computing thermodynamically consistent estimates of the rate constants of a closed biochemical reaction system with known stoichiometry given experimental data. Our method employs an appropriately designed prior probability density function that effectively integrates fundamental biophysical and thermodynamic knowledge into the inference problem. Moreover, it takes into account experimental strategies for collecting informative observations of molecular concentrations through perturbations. The proposed method employs a maximization-expectation-maximization algorithm that provides thermodynamically feasible estimates of the rate constant values and computes appropriate measures of estimation accuracy. We demonstrate various aspects of the proposed method on synthetic data obtained by simulating a subset of a well-known model of the EGF/ERK signaling pathway, and examine its robustness under conditions that violate key assumptions. Software, coded in MATLAB®, which implements all Bayesian analysis techniques discussed in this paper, is available free of charge at http://www.cis.jhu.edu/~goutsias/CSS%20lab/software.html. Conclusions Our approach provides an attractive statistical methodology for

  17. Controlling variation in the comet assay

    Directory of Open Access Journals (Sweden)

    Andrew Richard Collins

    2014-10-01

    Full Text Available Variability of the comet assay is a serious issue, whether it occurs from experiment to experiment in the same laboratory, or between different laboratories analysing identical samples. Do we have to live with high variability, just because the comet assay is a biological assay rather than analytical chemistry? Numerous attempts have been made to limit variability by standardising the assay protocol, and the critical steps in the assay have been identified; agarose concentration, duration of alkaline incubation, and electrophoresis conditions (time, temperature and voltage gradient are particularly important. Even when these are controlled, variation seems to be inevitable. It is helpful to include in experiments reference standards, i.e. cells with a known amount of specific damage to the DNA. They can be aliquots frozen from a single large batch of cells, either untreated (negative controls or treated with, for example, H2O2 or X-rays to induce strand breaks (positive control for the basic assay, or photosensitiser plus light to oxidise guanine (positive control for Fpg- or OGG1-sensitive sites. Reference standards are especially valuable when performing a series of experiments over a long period - for example, analysing samples of white blood cells from a large human biomonitoring trial - to check that the assay is performing consistently, and to identify anomalous results necessitating a repeat experiment. The reference values of tail intensity can also be used to iron out small variations occurring from day to day. We present examples of the use of reference standards in human trials, both within one laboratory and between different laboratories, and describe procedures that can be used to control variation.

  18. INVESTIGATIONS ON BIOCHEMICAL PURIFICATION OF GROUND WATER FROM HYDROGEN SULFIDE

    Directory of Open Access Journals (Sweden)

    Yu. P. Sedlukho

    2015-01-01

    Full Text Available The paper considers problems and features of biochemical removal of hydrogen sulfide from ground water. The analysis of existing methods for purification of ground water from hydrogen sulfide has been given in the paper. The paper has established shortcomings of physical and chemical purification of ground water. While using aeration methods for removal of hydrogen sulfide formation of colloidal sulfur that gives muddiness and opalescence to water occurs due to partial chemical air oxidation. In addition to this violation of sulfide-carbonate equilibrium taking place in the process of aeration due to desorption of H2S and CO2, often leads to clogging of degasifier nozzles with formed CaCO3 that causes serious operational problems. Chemical methods require relatively large flow of complex reagent facilities, storage facilities and transportation costs.In terms of hydrogen sulfide ground water purification the greatest interest is given to the biochemical method. Factors deterring widespread application of the biochemical method is its insufficient previous investigation and necessity to execute special research in order to determine optimal process parameters while purifying groundwater of a particular water supply source. Biochemical methods for oxidation of sulfur compounds are based on natural biological processes that ensure natural sulfur cycle. S. Vinogradsky has established a two-stage mechanism for oxidation of hydrogen sulfide with sulfur bacteria (Beggiatoa. The first stage presupposes oxidation of hydrogen sulphide to elemental sulfur which is accumulating in the cytoplasm in the form of globules. During the second stage sulfur bacteria begin to oxidize intracellular sulfur to sulfuric acid due to shortage of hydrogen sulfide.The paper provides the results of technological tests of large-scale pilot plants for biochemical purification of groundwater from hydrogen sulfide in semi-industrial conditions. Dependences of water quality

  19. Biochemical characterization of a recombinant Japanese encephalitis virus RNA-dependent RNA polymerase

    Directory of Open Access Journals (Sweden)

    Kim Chan-Mi

    2007-07-01

    Full Text Available Abstract Background Japanese encephalitis virus (JEV NS5 is a viral nonstructural protein that carries both methyltransferase and RNA-dependent RNA polymerase (RdRp domains. It is a key component of the viral RNA replicase complex that presumably includes other viral nonstructural and cellular proteins. The biochemical properties of JEV NS5 have not been characterized due to the lack of a robust in vitro RdRp assay system, and the molecular mechanisms for the initiation of RNA synthesis by JEV NS5 remain to be elucidated. Results To characterize the biochemical properties of JEV RdRp, we expressed in Escherichia coli and purified an enzymatically active full-length recombinant JEV NS5 protein with a hexahistidine tag at the N-terminus. The purified NS5 protein, but not the mutant NS5 protein with an Ala substitution at the first Asp of the RdRp-conserved GDD motif, exhibited template- and primer-dependent RNA synthesis activity using a poly(A RNA template. The NS5 protein was able to use both plus- and minus-strand 3'-untranslated regions of the JEV genome as templates in the absence of a primer, with the latter RNA being a better template. Analysis of the RNA synthesis initiation site using the 3'-end 83 nucleotides of the JEV genome as a minimal RNA template revealed that the NS5 protein specifically initiates RNA synthesis from an internal site, U81, at the two nucleotides upstream of the 3'-end of the template. Conclusion As a first step toward the understanding of the molecular mechanisms for JEV RNA replication and ultimately for the in vitro reconstitution of viral RNA replicase complex, we for the first time established an in vitro JEV RdRp assay system with a functional full-length recombinant JEV NS5 protein and characterized the mechanisms of RNA synthesis from nonviral and viral RNA templates. The full-length recombinant JEV NS5 will be useful for the elucidation of the structure-function relationship of this enzyme and for the

  20. Biochemical and molecular characterization of the gentisate transporter GenK in Corynebacterium glutamicum.

    Directory of Open Access Journals (Sweden)

    Ying Xu

    Full Text Available BACKGROUND: Gentisate (2,5-dihydroxybenzoate is a key ring-cleavage substrate involved in various aromatic compounds degradation. Corynebacterium glutamicum ATCC13032 is capable of growing on gentisate and genK was proposed to encode a transporter involved in this utilization by its disruption in the restriction-deficient mutant RES167. Its biochemical characterization by uptake assay using [(14C]-labeled gentisate has not been previously reported. METHODOLOGY/PRINCIPAL FINDINGS: In this study, biochemical characterization of GenK by uptake assays with [(14C]-labeled substrates demonstrated that it specifically transported gentisate into the cells with V(max and K(m of 3.06 ± 0.16 nmol/min/mg of dry weight and 10.71 ± 0.11 µM respectively, and no activity was detected for either benzoate or 3-hydoxybenzoate. When GenK was absent in strain RES167 ΔgenK, it retained 85% of its original transport activity at pH 6.5 compared to that of strain RES167. However, it lost 79% and 88% activity at pH 7.5 and 8.0, respectively. A number of competing substrates, including 3-hydroxybenzoate, benzoate, protocatechuate and catechol, significantly inhibited gentisate uptake by more than 40%. Through site-directed mutagenesis, eight amino acid residues of GenK, Asp-54, Asp-57 and Arg-386 in the hydrophobic transmembrane regions and Arg-103, Trp-309, Asp-312, Arg-313 and Ile-317 in the hydrophilic cytoplasmic loops were shown to be important for gentisate transport. When conserved residues Asp-54 and Asp-57 respectively were changed to glutamate, both mutants retained approximately 50% activity and were able to partially complement the ability of strain RES167 ΔgenK to grow on gentisate. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that GenK is an active gentisate transporter in Corynebacterium glutamicum ATCC13032. The GenK-mediated gentisate transport was also shown to be a limiting step for the gentisate utilization by this strain. This enhances our

  1. Comet assay on mice testicular cells

    Directory of Open Access Journals (Sweden)

    Anoop Kumar Sharma

    2015-05-01

    Full Text Available Heritable mutations may result in a variety of adverse outcomes including genetic disease in the offspring. In recent years the focus on germ cell mutagenicity has increased and the “Globally Harmonized System of Classification and Labelling of Chemicals (GHS” has published classification criteria for germ cell mutagens (Speit et al., 2009. The in vivo Comet assay is considered a useful tool for investigating germ cell genotoxicity. In the present study DNA strand breaks in testicular cells of mice were investigated. Different classes of chemicals were tested in order to evaluate the sensitivity of the comet assay in testicular cells. The chemicals included environmentally relevant substances such as Bisphenol A, PFOS and Tetrabrombisphenol A. Statistical power calculations will be presented to aid in the design of future Comet assay studies on testicular cells. Power curves were provided with different fold changes in % tail DNA, different number of cells scored and different number of gels (Hansen et al., 2014. An example is shown in Figure 1. A high throughput version of the Comet assay was used. Samples were scored with a fully automatic comet assay scoring system that provided faster scoring of randomly selected cells.

  2. The micronucleus assay in radiation accidents

    International Nuclear Information System (INIS)

    The cytokinesis-block micronucleus assay in peripheral blood lymphocytes is a standardised and validated technique for bio dosimetry. Automated scoring of micronuclei allows large scale applications as in population triage in case of radiation accidents or malevolent use of radioactive sources. The dose detection limit (95% confidence) of the micronucleus assay for individual dose assessment is restricted to 0.2 Gy but can be decreased to 0.1 Gy by scoring centromeres in micronuclei using fluorescence in situ hybridization (FISH). In the past the micronucleus assay was applied for a number of large scale bio monitoring studies of nuclear power plant workers and hospital workers. Baseline micronucleus frequencies depend strongly on age and gender. The assay was also already used for bio dosimetry of radiation accidents. In a multiple endpoint bio dosimetry study for dose assessment of a worker exposed accidentally in 2003 to X-rays, a good agreement was obtained between dose estimates resulting from the micronucleus assay, the scoring of dicentrics and translocations. Automated scoring of micronuclei in combination with centromere signals, allowing systematic bio dosimetry of exposed populations, remains a challenge for the future.

  3. Potentiometric assay for acid and alkaline phosphatase

    International Nuclear Information System (INIS)

    Simple potentiometric kinetic assay for evaluation of acid and alkaline phosphatase activity has been developed. Enzymatically catalyzed hydrolysis of monofluorophosphate, the simplest inorganic compound containing P-F bond, has been investigated as the basis of the assays. Fluoride ions formed in the course of the hydrolysis of this specific substrate have been detected using conventional fluoride ion-selective electrode based on membrane made of lanthanum fluoride. The key analytical parameters necessary for sensitive and selective detection of both enzymes have been assessed. Maximal sensitivity of the assays was observed at monofluorophosphate concentration near 10-3 M. Maximal sensitivity of acid phosphatase assay was found at pH 6.0, but pH of 4.8 is recommended to eliminate effects from alkaline phosphatase. Optimal pH for alkaline phosphatase assay is 9.0. The utility of the developed substrate-sensor system for determination of acid and alkaline phosphatase activity in human serum has been demonstrated

  4. Simultaneous detection of six diarrhea-causing bacterial pathogens with an in-house PCR-luminex assay.

    Science.gov (United States)

    Liu, Jie; Gratz, Jean; Maro, Athanasia; Kumburu, Happy; Kibiki, Gibson; Taniuchi, Mami; Howlader, Arif Mahmud; Sobuz, Shihab U; Haque, Rashidul; Talukder, Kaisar A; Qureshi, Shahida; Zaidi, Anita; Haverstick, Doris M; Houpt, Eric R

    2012-01-01

    Diarrhea can be caused by a range of pathogens, including several bacteria. Conventional diagnostic methods, such as culture, biochemical tests, and enzyme-linked immunosorbent assay (ELISA), are laborious. We developed a 7-plex PCR-Luminex assay to simultaneously screen for several of the major diarrhea-causing bacteria directly in fecal specimens, including pathogenic Aeromonas, Campylobacter jejuni, Campylobacter coli, Salmonella, Shigella, enteroinvasive Escherichia coli (EIEC), Vibrio, and Yersinia. We included an extrinsic control to verify extraction and amplification. The assay was first validated with reference strains or isolates and exhibited a limit of detection of 10(3) to 10(5) CFU/g of stool for each pathogen as well as quantitative detection up to 10(9) CFU/g. A total of 205 clinical fecal specimens from individuals with diarrhea, previously cultured for enteric pathogens and tested for Campylobacter by ELISA, were evaluated. Using these predicate methods as standards, sensitivities and specificities of the PCR-Luminex assay were 89% and 94% for Aeromonas, 89% and 93% for Campylobacter, 96% and 95% for Salmonella, 94% and 94% for Shigella, 92% and 97% for Vibrio, and 100% and 100% for Yersinia, respectively. All discrepant results were further examined by singleplex real-time PCR assays targeting different gene regions, which revealed 89% (55/62 results) concordance with the PCR-Luminex assay. The fluorescent signals obtained with this approach exhibited a statistically significant correlation with the cycle threshold (C(T)) values from the cognate real-time PCR assays (P PCR-Luminex assay enables sensitive, specific, and quantitative detection of the major bacterial causes of gastroenteritis. PMID:22075596

  5. Students' Ability to Organize Biochemical and Biochemistry-Related Terms Correlates with Their Performance in a Biochemical Examination

    Science.gov (United States)

    Nagata, Ryoichi

    2007-01-01

    Organization is believed to be related to understanding and memory. Whether this belief was applicable in biochemical education was examined about two years after students had experienced biochemistry classes in their first year. The ability of organizing information in biochemistry was judged from the number of correct links of 886 biochemical…

  6. Detection of antigen interactions ex vivo by proximity ligation assay: endogenous dopamine D2-adenosine A2A receptor complexes in the striatum

    OpenAIRE

    Trifilieff, Pierre; Rives, Marie-Laure; Urizar, Eneko; Piskorowski, Rebecca A.; Vishwasrao, Harshad D.; Castrillon, John; Schmauss, Claudia; Slättman, Maria; Gullberg, Mats; Javitch, Jonathan A.

    2011-01-01

    The existence of G protein-coupled receptor (GPCR) dimers and/or oligomers has been demonstrated in heterologous systems using a variety of biochemical and biophysical assays. While these interactions are the subject of intense research because of their potential role in modulating signaling and altering pharmacology, evidence for the existence of receptor interactions in vivo is still elusive because of a lack of appropriate methods to detect them. Here, we adapted and optimized a proximity ...

  7. Assays for thyroid-stimulating hormone receptor antibodies employing different ligands and ligand partners may have similar sensitivity and specificity but are not interchangeable

    DEFF Research Database (Denmark)

    Pedersen, Inge Bülow; Handberg, Aase; Knudsen, Nils Jakob;

    2010-01-01

    The best biochemical marker of Graves' disease (GD) is the presence in serum of autoantibodies to the thyroid-stimulating hormone receptor (hTSHR-Ab). The aim of this study was to evaluate the performances of two sensitive hTSHR-Ab assays with a specific focus on the clinical importance of differ......TSHR-Ab competes with labeled bovine TSH for binding to recombinant human TSH receptors....

  8. Development of an integrated assay facility

    International Nuclear Information System (INIS)

    The I.R.I.S. concept proposed the use of passive examination and active interrogation techniques in an integrated assay facility. A linac would generate the interrogating gamma and neutron beams. Insufficiently detailed knowledge about active neutron and gamma interrogation of 500 litre drums of cement immobilised intermediate level waste led to a research programme which is now in its main experimental stage. Measurements of interrogation responses are being made using simulated waste drums containing actinide samples and calibration sources, in an experimental assay assembly. Results show that responses are generally consistent with theory, but that improvements are needed in some areas. A preliminary appraisal of the engineering and economic aspects of integrated assay shows that correct operational sequencing is required to achieve the short cycle time needed for high throughput. The main engineering features of a facility have been identified

  9. Nuclear Resonance Fluorescence for Materials Assay

    Energy Technology Data Exchange (ETDEWEB)

    Quiter, Brian J.; Ludewigt, Bernhard; Mozin, Vladimir; Prussin, Stanley

    2009-06-29

    This paper discusses the use of nuclear resonance fluorescence (NRF) techniques for the isotopic and quantitative assaying of radioactive material. Potential applications include age-dating of an unknown radioactive source, pre- and post-detonation nuclear forensics, and safeguards for nuclear fuel cycles Examples of age-dating a strong radioactive source and assaying a spent fuel pin are discussed. The modeling work has ben performed with the Monte Carlo radiation transport computer code MCNPX, and the capability to simulate NRF has bee added to the code. Discussed are the limitations in MCNPX?s photon transport physics for accurately describing photon scattering processes that are important contributions to the background and impact the applicability of the NRF assay technique.

  10. Nuclear Resonance Fluorescence for Materials Assay

    Energy Technology Data Exchange (ETDEWEB)

    Quiter, Brian; Ludewigt, Bernhard; Mozin, Vladimir; Prussin, Stanley

    2009-06-05

    This paper discusses the use of nuclear resonance fluorescence (NRF) techniques for the isotopic and quantitative assaying of radioactive material. Potential applications include age-dating of an unknown radioactive source, pre- and post-detonation nuclear forensics, and safeguards for nuclear fuel cycles Examples of age-dating a strong radioactive source and assaying a spent fuel pin are discussed. The modeling work has ben performed with the Monte Carlo radiation transport computer code MCNPX, and the capability to simulate NRF has bee added to the code. Discussed are the limitations in MCNPX's photon transport physics for accurately describing photon scattering processes that are important contributions to the background and impact the applicability of the NRF assay technique.

  11. Monitoring environmental exposures with semen assays

    International Nuclear Information System (INIS)

    Semen studies in humans and animals have yielded extensive and compelling evidence that sperm can be used to assess reproductive potential and diagnose pathology. More recent studies on mutagens and carcinogens both at this and other laboratories suggest that a combination of mouse and human assays can be an efficient, effective approach to monitoring for reproductive hazards in the environment. We are investigating the potential of using variability in sperm morphology and DNA content to quantify and monitor the effects of environmental agents on the human testes. Here we review the status of human and mouse assays for environmental surveillance, discuss the genetic and fertility implications of chemically induced semen changes, and describe the high-speed flow methods being developed to automate sperm assays

  12. Comet assay on tetraploid yeast cells

    DEFF Research Database (Denmark)

    Rank, Jette; Syberg, Kristian; Jensen, Klara

    2009-01-01

    Tetraploid yeast cells (Saccharomyces cerevisiae) were used in the comet assay with the intention of developing a new, fast and easy assay for detecting environmental genotoxic agents without using higher organisms. Two DNA-damaging chemicals, H2O2 and acrylamide, together with wastewater from...... three municipal treatment plants were tested for their effect on the yeast-cell DNA. The main problem with using yeast in the comet assay is the necessity to degrade the cell wall. This was achieved by using Zymolase 100 T twice during the procedure, since Zymolase 20 T did not open the cell wall...... causing significant DNA damage was 20 μM for H2O2 and 200 mg/l for acrylamide. Tertiary-treated wastewater from the outlets of three municipal wastewater-treatment plants was tested, but did not cause DNA damage. Even though it is possible to produce comets with tetraploid yeast cells, the amount of DNA...

  13. Nuclear Resonance Fluorescence for Materials Assay

    International Nuclear Information System (INIS)

    This paper discusses the use of nuclear resonance fluorescence (NRF) techniques for the isotopic and quantitative assaying of radioactive material. Potential applications include age-dating of an unknown radioactive source, pre- and post-detonation nuclear forensics, and safeguards for nuclear fuel cycles Examples of age-dating a strong radioactive source and assaying a spent fuel pin are discussed. The modeling work has been performed with the Monte Carlo radiation transport computer code MCNPX, and the capability to simulate NRF has bee added to the code. Discussed are the limitations in MCNPX?s photon transport physics for accurately describing photon scattering processes that are important contributions to the background and impact the applicability of the NRF assay technique.

  14. Nanoparticles for Use in Enzyme Assays.

    Science.gov (United States)

    Kim, Young-Pil; Kim, Hak-Sung

    2016-02-01

    Nanoparticles (NPs) have created new ways to enhance the performance of classical biosensors in analytical sciences. NPs with unprecedented physiochemical properties can serve both as excellent carriers of bioreceptors and as signal enhancers, leading to improved assay platforms with high sensitivity and selectivity. Because enzymes play central roles in many cellular functions, specific and precise assays of their functions are of great significance in medical science and biotechnology. Here we review recent advances in NP-based biosensors and their use in enzyme assays. With fast and specific responses to enzyme-mediated reactions, NPs transduce and amplify the initial responses into various types of signals, such as electrochemical, optical and magnetic ones. Translation of their potential should lead to functionalized NPs finding wide applications in diagnostics, drug development and biotechnology. PMID:26662229

  15. Alteration of biochemical parameters after supplementation of multivitamins and minerals of sprayers on grape gardens of Western Maharashtra (India

    Directory of Open Access Journals (Sweden)

    Jyotsna A. Patil

    2014-01-01

    Full Text Available Background: In the horticulture sector, the land used for cash crop like grapes is increasing particularly in Maharashtra state. There is an increasing use of the pesticides in an attempt to increase the yield and reduce the post harvest losses. The environmental pollution and poisoning due to wide use of pesticide during grape cultivation may be much more important factors to disturb the socio economical status of uneducated farm worker in rural areas. Aim and Objectives: The study aimed to evaluate the pesticide exposure of the population associated with grape cultivation with respect to biochemical effects, oxidative stress, antioxidants status and protecting them from such effects by supplementing vitamins A to Z. Material and Methods: For this study 30 subjects with occupational pesticides exposure i.e. sprayers of grape gardens having age in the range of 20 to 45 years from Tasgaon taluka, Sangli district, (Western Maharashtra India were taken and all these study group subject,500 mg vitamin A to Z tablet / day for fifteen days were supplemented. The blood was collected by venipuncture from all these subjects for biochemical parameters assay before and after fifteen days of vitamins A to Z supplementation and all biochemical parameters were estimated by using standard methods. Results: Fifteen days vitamin A to Z and multi minerals supplementation to sprayers of grape gardens, we observed significant increase in serum Acetyl Cholinesterase (P<0.001, 2.32%, and decreased Aspartate Transaminase (P<0.05, 8.36%, Alanine Transaminase (P<0.05, 14.16%, serum Lipid Peroxide (P<0.001, 24.39%, Glutathione S-Transferase (P<0.01, 29.84% and increased RBC-Superoxide Dismutase (P<0.05, 11.55%, RBC-Catalase (P<0.001, 25.7%, serum zinc (P<0.01, 3.74%, copper (P<0.001, 4.13%, blood lead (P<0.01, 3.33% as compared to before vitamin A to Z and multi minerals supplementation and other biochemical parameters such as serum C-Reactive Proteins, Total Proteins

  16. The Comet Assay: Tails of the (Un)expected. Use of the comet assay in pharmaceutical development.

    OpenAIRE

    Bas-jan Van Der Leede

    2015-01-01

    In genotoxicity testing of pharmaceuticals the rodent alkaline comet assay is being increasingly used as a second in vivo assay in addition to the in vivo micronucleus assay to mitigate in vitro positive results as recommended by regulatory guidance. In this presentation we want to give insight into the circumstances in vivo comet assay is deployed in a Genetic Toxicology Department of a pharmaceutical company. As the in vivo comet assay is a salvage assay, it means that some events have occu...

  17. An arranged marriage for precision medicine: hypoxia and genomic assays in localized prostate cancer radiotherapy.

    Science.gov (United States)

    Bristow, R G; Berlin, A; Dal Pra, A

    2014-03-01

    Prostate cancer (CaP) is the most commonly diagnosed malignancy in males in the Western world with one in six males diagnosed in their lifetime. Current clinical prognostication groupings use pathologic Gleason score, pre-treatment prostatic-specific antigen and Union for International Cancer Control-TNM staging to place patients with localized CaP into low-, intermediate- and high-risk categories. These categories represent an increasing risk of biochemical failure and CaP-specific mortality rates, they also reflect the need for increasing treatment intensity and justification for increased side effects. In this article, we point out that 30-50% of patients will still fail image-guided radiotherapy or surgery despite the judicious use of clinical risk categories owing to interpatient heterogeneity in treatment response. To improve treatment individualization, better predictors of prognosis and radiotherapy treatment response are needed to triage patients to bespoke and intensified CaP treatment protocols. These should include the use of pre-treatment genomic tests based on DNA or RNA indices and/or assays that reflect cancer metabolism, such as hypoxia assays, to define patient-specific CaP progression and aggression. More importantly, it is argued that these novel prognostic assays could be even more useful if combined together to drive forward precision cancer medicine for localized CaP. PMID:24588670

  18. Relationship between the radioisotopic footpad assay and other immunological assays in tumor bearing rats

    International Nuclear Information System (INIS)

    KMT-17, a fibrosarcoma induced by 3-methylcholanthrene in a WKA rat, is a sensitive tumor to various kinds of immunological assays and is a suitable model tumor for the study of the immune status in tumor bearing hosts. The antitumor immune response of KMT-17 bearing rats was studied by a radioisotopic footpad assay (FPA) in comparison with other in vivo and in vitro assays. Delayed hypersensitivity to tumor antigens measured by the FPA was observed from the 8th day after transplantation of KMT-17 cells, reached a peak on the 12 - 15th day, and then declined in the late stage on the 17th day. The kinetics of the FPA correlated well with those of an in vivo Winn assay and of an in vitro lymphocyte cytotoxicity assay (51Cr-release assay). The appearance of an antitumor antibody detected by a complement dependent cytotoxicity test also correlated well with the kinetics of the FPA. A growth inhibition assay (GIA) for non-specific cell-mediated immunity also showed similar kinetics to that of the FPA. The delayed hypersensitivity footpad reaction to tumor cell extracts measured by this FPA was tumor-specific. These results suggest that the FPA is a simple and reliable in vivo assay for evaluating antitumor immunity in tumor bearing hosts. (author)

  19. Instructions for Uploading Data to the Assay Portal - Instructions for Uploading Data to the Assay Portal

    Science.gov (United States)

    This document provides instructions for configuring and uploading data files to the CPTAC Assay Portal. It is divided into sections, with an overview checklist provided at the end. If help is needed at any stage of the process, please use the support page: https://assays.cancer.gov/support/

  20. Bicinchoninic acid (BCA) assay in low volume.

    Science.gov (United States)

    Bainor, Anthony; Chang, Lyra; McQuade, Thomas J; Webb, Brian; Gestwicki, Jason E

    2011-03-15

    The BCA assay is a colorimetric method for estimating protein concentration. In 96-well plates, the relationship between protein content and absorbance is nearly linear over a wide range; however, performance is reduced in lower volume. To overcome this limitation, we performed the BCA assays in opaque, white 384-well plates. These plates emit fluorescence between 450-600 nm when excited at 430 nm; thus, their fluorescence is quenched by the BCA chromophore (λ(max) 562 nm). This arrangement allowed accurate determination of protein content using only 2 μL of sample. Moreover, soluble flourescein could replace the white plates, creating a homogenous format. PMID:21078286