Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts

International Nuclear Information System (INIS)

Li, D.X.; Deng, T.Z.; Lv, J.; Ke, J.

2014-01-01

Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA), bovine serum albumin (BSA) alone, or given no treatment (control). Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80±5.50%, P<0.01) and increased apoptosis (11.31±1.73%, P<0.05). Hoechst 33258 staining and terminal-deoxynucleotidyl transferase-mediated nick-end labeling revealed that AGE-BSA significantly increased apoptosis of PDL fibroblasts. The results showed that the changes in PDL fibroblasts induced by AGE-BSA may explain how AGE-RAGE participates in and exacerbates periodontium destruction

Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Li, D.X.; Deng, T.Z.; Lv, J.; Ke, J. [Department of Stomatology, Air Force General Hospital PLA, Haidian District, Beijing (China)

2014-09-19

Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA), bovine serum albumin (BSA) alone, or given no treatment (control). Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80±5.50%, P<0.01) and increased apoptosis (11.31±1.73%, P<0.05). Hoechst 33258 staining and terminal-deoxynucleotidyl transferase-mediated nick-end labeling revealed that AGE-BSA significantly increased apoptosis of PDL fibroblasts. The results showed that the changes in PDL fibroblasts induced by AGE-BSA may explain how AGE-RAGE participates in and exacerbates periodontium destruction.

NCYM promotes calpain-mediated Myc-nick production in human MYCN-amplified neuroblastoma cells

Energy Technology Data Exchange (ETDEWEB)

Shoji, Wataru [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Department of Pediatric Surgery, Graduate School of Medicine, Tohoku University, Sendai 980-8574 (Japan); Suenaga, Yusuke, E-mail: ysuenaga@chiba-cc.jp [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Cancer Genome Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Kaneko, Yoshiki; Islam, S.M. Rafiqul; Alagu, Jennifer [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Yokoi, Sana [Cancer Genome Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Nio, Masaki [Department of Pediatric Surgery, Graduate School of Medicine, Tohoku University, Sendai 980-8574 (Japan); Nakagawara, Akira, E-mail: nakagawara-a@koseikan.jp [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan)

2015-06-05

NCYM is a cis-antisense gene of MYCN and is amplified in human neuroblastomas. High NCYM expression is associated with poor prognoses, and the NCYM protein stabilizes MYCN to promote proliferation of neuroblastoma cells. However, the molecular mechanisms of NCYM in the regulation of cell survival have remained poorly characterized. Here we show that NCYM promotes cleavage of MYCN to produce the anti-apoptotic protein, Myc-nick, both in vitro and in vivo. NCYM and Myc-nick were induced at G2/M phase, and NCYM knockdown induced apoptotic cell death accompanied by Myc-nick downregulation. These results reveal a novel function of NCYM as a regulator of Myc-nick production in human neuroblastomas. - Highlights: • NCYM promotes cleavages of MYC and MYCN to produce Myc-nick in vitro. • NCYM increases Myc-nick production in MYCN-amplified neuroblastoma cells. • NCYM knockdown decreases Myc-nick production and induces apoptosis at G2/M phase.

NCYM promotes calpain-mediated Myc-nick production in human MYCN-amplified neuroblastoma cells

International Nuclear Information System (INIS)

Shoji, Wataru; Suenaga, Yusuke; Kaneko, Yoshiki; Islam, S.M. Rafiqul; Alagu, Jennifer; Yokoi, Sana; Nio, Masaki; Nakagawara, Akira

2015-01-01

NCYM is a cis-antisense gene of MYCN and is amplified in human neuroblastomas. High NCYM expression is associated with poor prognoses, and the NCYM protein stabilizes MYCN to promote proliferation of neuroblastoma cells. However, the molecular mechanisms of NCYM in the regulation of cell survival have remained poorly characterized. Here we show that NCYM promotes cleavage of MYCN to produce the anti-apoptotic protein, Myc-nick, both in vitro and in vivo. NCYM and Myc-nick were induced at G2/M phase, and NCYM knockdown induced apoptotic cell death accompanied by Myc-nick downregulation. These results reveal a novel function of NCYM as a regulator of Myc-nick production in human neuroblastomas. - Highlights: • NCYM promotes cleavages of MYC and MYCN to produce Myc-nick in vitro. • NCYM increases Myc-nick production in MYCN-amplified neuroblastoma cells. • NCYM knockdown decreases Myc-nick production and induces apoptosis at G2/M phase

Labelling of end-of-life decisions by physicians.

Science.gov (United States)

Deyaert, Jef; Chambaere, Kenneth; Cohen, Joachim; Roelands, Marc; Deliens, Luc

2014-07-01

Potentially life-shortening medical end-of-life practices (end-of-life decisions (ELDs)) remain subject to conceptual vagueness. This study evaluates how physicians label these practices by examining which of their own practices (described according to the precise act, the intention, the presence of an explicit patient request and the self-estimated degree of life shortening)they label as euthanasia or sedation. We conducted a large stratified random sample of death certificates from 2007 (N=6927).The physicians named on the death certificate were approached by means of a postal questionnaire asking about ELDs made in each case and asked to choose the most appropriate label to describe the ELD. Response rate was 58.4%. In the vast majority of practices labelled as euthanasia, the self-reported actions of the physicians corresponded with the definition in the Belgian euthanasia legislation; practices labelled as palliative or terminal sedation lack clear correspondence with definitions of sedation as presented in existing guidelines. In these cases, an explicit life-shortening intention by means of drug administration was present in 21.6%, life shortening was estimated at more than 24 h in 51% and an explicit patient request was absentin 79.7%. Our results suggest that, unlike euthanasia,the concept of palliative or terminal sedation covers abroad range of practices in the minds of physicians. This ambiguity can be a barrier to appropriate sedation practice and indicates a need for better knowledge of the practice of palliative sedation by physicians.

Inhibition of histone deacetylases prevents cytokine-induced toxicity in beta cells

DEFF Research Database (Denmark)

Larsen, L; Tonnesen, M; Ronn, S G

2007-01-01

B (NFkappaB) is a critical signalling molecule in inflammation and is required for expression of the gene encoding inducible NO synthase (iNOS) and of pro-apoptotic genes. NFkappaB has recently been shown to associate with chromatin-modifying enzymes histone acetyltransferases and histone...... by immunoblotting and by immunoblotting combined with electrophoretic mobility shift assay, respectively. Viability was analysed by 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyl-tetrazolium bromide and apoptosis by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay and histone...

Label-acquired magnetorotation for biosensing: An asynchronous rotation assay

International Nuclear Information System (INIS)

Hecht, Ariel; Kinnunen, Paivo; McNaughton, Brandon; Kopelman, Raoul

2011-01-01

This paper presents a novel application of magnetic particles for biosensing, called label-acquired magnetorotation (LAM). This method is based on a combination of the traditional sandwich assay format with the asynchronous magnetic bead rotation (AMBR) method. In label-acquired magnetorotation, an analyte facilitates the binding of a magnetic label bead to a nonmagnetic solid phase sphere, forming a sandwich complex. The sandwich complex is then placed in a rotating magnetic field, where the rotational frequency of the sandwich complex is a function of the amount of analyte attached to the surface of the sphere. Here, we use streptavidin-coated beads and biotin-coated particles as analyte mimics, to be replaced by proteins and other biological targets in future work. We show this sensing method to have a dynamic range of two orders of magnitude.

DNA fragments assembly based on nicking enzyme system.

Directory of Open Access Journals (Sweden)

Rui-Yan Wang

Full Text Available A couple of DNA ligation-independent cloning (LIC methods have been reported to meet various requirements in metabolic engineering and synthetic biology. The principle of LIC is the assembly of multiple overlapping DNA fragments by single-stranded (ss DNA overlaps annealing. Here we present a method to generate single-stranded DNA overlaps based on Nicking Endonucleases (NEases for LIC, the method was termed NE-LIC. Factors related to cloning efficiency were optimized in this study. This NE-LIC allows generating 3'-end or 5'-end ss DNA overlaps of various lengths for fragments assembly. We demonstrated that the 10 bp/15 bp overlaps had the highest DNA fragments assembling efficiency, while 5 bp/10 bp overlaps showed the highest efficiency when T4 DNA ligase was added. Its advantage over Sequence and Ligation Independent Cloning (SLIC and Uracil-Specific Excision Reagent (USER was obvious. The mechanism can be applied to many other LIC strategies. Finally, the NEases based LIC (NE-LIC was successfully applied to assemble a pathway of six gene fragments responsible for synthesizing microbial poly-3-hydroxybutyrate (PHB.

Including 10-Gigabit-capable Passive Optical Network under End-to-End Generalized Multi-Protocol Label Switching Provisioned Quality of Service

DEFF Research Database (Denmark)

Brewka, Lukasz Jerzy; Gavler, Anders; Wessing, Henrik

2012-01-01

of the network where quality of service signaling is bridged. This article proposes strategies for generalized multi-protocol label switching control over next emerging passive optical network standard, i.e., the 10-gigabit-capable passive optical network. Node management and resource allocation approaches...... are discussed, and possible issues are raised. The analysis shows that consideration of a 10-gigabit-capable passive optical network as a generalized multi-protocol label switching controlled domain is valid and may advance end-to-end quality of service provisioning for passive optical network based customers.......End-to-end quality of service provisioning is still a challenging task despite many years of research and development in this area. Considering a generalized multi-protocol label switching based core/metro network and resource reservation protocol capable home gateways, it is the access part...

Applying label-free dynamic mass redistribution assay for studying endogenous FPR1 receptor signalling in human neutrophils

DEFF Research Database (Denmark)

Christensen, Hanna B; Gloriam, David E; Pedersen, Daniel Sejer

2017-01-01

INTRODUCTION: The label-free dynamic mass redistribution-based assay (DMR) is a powerful method for studying signalling pathways of G protein-coupled receptors (GPCRs). Herein we present the label-free DMR assay as a robust readout for pharmacological characterization of formyl peptide receptors...... (FPRs) in human neutrophils. METHODS: Neutrophils were isolated from fresh human blood and their responses to FPR1 and FPR2 agonists, i.e. compound 43, fMLF and WKYMVm were measured in a label-free DMR assay using Epic Benchtop System from Corning®. Obtained DMR traces were used to calculate agonist...... potencies. RESULTS: The potencies (pEC50) of fMLF, WKYMVm and compound 43, determined on human neutrophils using the label-free DMR assay were 8.63, 7.76 and 5.92, respectively. The DMR response to fMLF, but not WKYMVm and compound 43 could be blocked by the FPR1-specific antagonist cyclosporin H...

Nick Park pani Wallace'ile ja Gromitile libaküüliku needuse / Mart Rummo

Index Scriptorium Estoniae

Rummo, Mart

2005-01-01

Uus animafilm "Wallace ja Gromit : Libaküüliku needus" ("Wallace & Gromit : The Curse of the Were-Rabbit") : režissöör Nick Park : Suurbritannia 2005. Selle loojast ja tema loometeest. Lisatud : Nick Park (filmograafia, auhindu), "Teised Nick Parkist" (Lauri Kaare, Mait Laas, Riho Unt)

Essays on the future in honor of Nick Metropolis

CERN Document Server

Rota, Gian-Carlo

2000-01-01

This collection represents a unique undertaking in scientific publishing to honor Nick Metropolis. Nick was the last survivor of the World War II Manhattan Project in Los Alamos, and was an important member of the Los Alamos national Laboratory until his death in October, 1999. In this volume, some of the leading scientists and humanists of our time have contributed essays related to their respective disciplines, exploring various aspects of future developments in science and society, philosophy, national security, nuclear power, pure and applied mathematics, physics and biology, particle physics, computing, and information science.

A systematic review on sperm DNA fragmentation in male factor infertility: Laboratory assessment

Directory of Open Access Journals (Sweden)

Manesh Kumar Panner Selvam

2018-03-01

Full Text Available Objective: To review sperm DNA fragmentation (SDF testing as an important sperm function test in addition to conventional semen analysis. High SDF is negatively associated with semen quality, the fertilisation process, embryo quality, and pregnancy outcome. Over recent decades, different SDF assays have been developed and reviewed extensively to assess their applicability and accuracy as advanced sperm function tests. Amongst them, the standardisation of the terminal deoxynucleotidyl transferased UTP nick-end labelling (TUNEL assay with a bench top flow cytometer in clinical practice deserves special mention with a threshold value of 16.8% to differentiate infertile men with DNA damage from fertile men. Materials and methods: A systematic literature search was performed through the PubMed, Medline, and ScienceDirect databases using the keywords ‘sperm DNA fragmentation’ and ‘laboratory assessment’. Non-English articles were excluded and studies related to humans were only included. Results: Of the 618 identified, 87 studies (original research and reviews and in addition eight book chapters meeting the selection criteria were included in this review. In all, 366 articles were rejected in the preliminary screening and a further 165 articles related to non-human subjects were excluded. Conclusion: There are pros and cons to all the available SDF assays. TUNEL is a reliable technique with greater accuracy and as an additional diagnostic test in Andrology laboratories along with basic semen analysis can predict fertility outcome, and thus direct the choice of an assisted reproductive technology procedure for infertile couples. Also, the TUNEL assay can be used as a prognostic test and results are beneficial in deciding personalised treatment for infertile men. Keywords: Sperm DNA fragmentation (SDF, Terminal deoxynucleotidyl transferased UTP nick-end labelling (TUNEL, DNA damage, Sperm DNA fragmentation (SDF assay

Myc-nick: a cytoplasmic cleavage product of Myc that promotes alpha-tubulin acetylation and cell differentiation.

Science.gov (United States)

Conacci-Sorrell, Maralice; Ngouenet, Celine; Eisenman, Robert N

2010-08-06

The Myc oncoprotein family comprises transcription factors that control multiple cellular functions and are widely involved in oncogenesis. Here we report the identification of Myc-nick, a cytoplasmic form of Myc generated by calpain-dependent proteolysis at lysine 298 of full-length Myc. Myc-nick retains conserved Myc box regions but lacks nuclear localization signals and the bHLHZ domain essential for heterodimerization with Max and DNA binding. Myc-nick induces alpha-tubulin acetylation and altered cell morphology by recruiting histone acetyltransferase GCN5 to microtubules. During muscle differentiation, while the levels of full-length Myc diminish, Myc-nick and acetylated alpha-tubulin levels are increased. Ectopic expression of Myc-nick accelerates myoblast fusion, triggers the expression of myogenic markers, and permits Myc-deficient fibroblasts to transdifferentiate in response to MyoD. We propose that the cleavage of Myc by calpain abrogates the transcriptional inhibition of differentiation by full-length Myc and generates Myc-nick, a driver of cytoplasmic reorganization and differentiation. Copyright 2010 Elsevier Inc. All rights reserved.

Solid-phase peptide quantitation assay using labeled monoclonal antibody and glutaraldehyde fixation

International Nuclear Information System (INIS)

Kasprzyk, P.G.; Cuttitta, F.; Avis, I.; Nakanishi, Y.; Treston, A.; Wong, H.; Walsh, J.H.; Mulshine, J.L.

1988-01-01

A solid-phase radioimmunoassay utilizing iodinated peptide-specific monoclonal antibody as a detection system instead of labeled peptide has been developed. Regional specific monoclonal antibodies to either gastrin-releasing peptide or gastrin were used as models to validate the general application of our modified assay. Conditions for radioactive labeling of the monoclonal antibody were determined to minimize oxidant damage, which compromises the sensitivity of other reported peptide quantitation assays. Pretreatment of 96-well polyvinyl chloride test plates with a 5% glutaraldehyde solution resulted in consistent retention of sufficient target peptide on the solid-phase matrix to allow precise quantitation. This quantitative method is completed within 1 h of peptide solid phasing. Pretreatment of assay plates with glutaraldehyde increased binding of target peptide and maximized antibody binding by optimizing antigen presentation. The hypothesis that glutaraldehyde affects both peptide binding to the plate and orientation of the peptide was confirmed by analysis of several peptide analogs. These studies indicate that peptide binding was mediated through a free amino group leaving the carboxy-terminal portion of the target peptide accessible for antibody binding. It was observed that the length of the peptide also affects the amount of monoclonal antibody that will bind. Under the optimal conditions, results from quantitation of gastrin-releasing peptide in relevant samples agree well with those from previously reported techniques. Thus, we report here a modified microplate assay which may be generally applied for the rapid and sensitive quantitation of peptide hormones

Labelled antibody assays for measuring free triiodothyronine: evaluation and comparison with a labelled analog method

International Nuclear Information System (INIS)

Sapin, R.; Gasser, F.; Schlienger, J.L.; Chambron, J.

1993-01-01

We evaluated analytically and clinically two new one-step labelled antibody assays for measuring free triiodothyronine (FT3): the first, radiolabelled with 125 I, Amerlex-MAB (MAB) from Kodak diagnostic, and the second, labelled with peroxidase, Enzymum-test FT3 (BM) from Boehringer Mannheim adapted for the Boehringer ES 600 analyzer. The clinical results were compared with those obtained with a radiolabelled analog tracer kit, Amerlex-M (M) from Kodak diagnostic. The latter kit is known to give low FT3 results in sera with low albumin concentrations. Analytical performances of the automated method (BM) were better than those obtained with the manual method (MAB): intra-assay reproducibility (CV<3% vs CV about 5%), inter-assay reproducibility (CV<4% vs CV between 4 and 8%) and mean drift (+1.25% vs -4.3%). The detection limit was low for both kits (<1 pmol/l). In the euthyroid reference group (n = 98) we observed a significant difference between outpatient and hospitalized patient FT3 concentrations as measured with the M kit only. Clinical sensitivity for hyperthyroidism (n = 38) was better for the MAB (92%) than for the BM kit (76%). Specificity in euthyroid L-thyroxine (T4) treated patients (n = 26) was good for both kits (MAB: 92%; BM: 88%) . Hypoalbuminemia (n = 8) decreased FT3 results as follows: M, very significantly; BM, significantly; MAB, only slightly. In patients treated with amiodarone (n = 5), a drug known to lower the metabolic conversion of T4 to T3, the increase of the MAB FT3 results contrasted with the decrease of the BM and M results. In conclusion, results of the two new kits were not strongly influenced by hypoalbuminemia. The MAB results showing lack of decrease in patients with non-thyroidal illness without hypoalbuminemia and in amiodarone-treated patients were unexpected

Sphingosine 1-phosphate lyase enzyme assay using a BODIPY-labeled substrate

International Nuclear Information System (INIS)

Bandhuvula, Padmavathi; Li Zaiguo; Bittman, Robert; Saba, Julie D.

2009-01-01

Sphingosine 1-phosphate lyase (SPL) is responsible for the irreversible catabolism of sphingosine 1-phosphate, which signals through five membrane receptors to mediate cell stress responses, angiogenesis, and lymphocyte trafficking. The standard assay for SPL activity utilizes a radioactive dihydrosphingosine 1-phosphate substrate and is expensive and cumbersome. In this study, we describe an SPL assay that employs an ω-labeled BODIPY-sphingosine 1-phosphate substrate, allowing fluorescent product detection by HPLC and incorporating advantages of the BODIPY fluorophore. The major aldehyde product is confirmed by reaction with 2,4-dinitrophenylhydrazine. The SPL-catalyzed reaction is linear over a 30 min time period and yields a K m of 35 μM for BODIPY-sphingosine 1-phosphate.

Electrochemical DNA sandwich assay with a lipase label for attomole detection of DNA

DEFF Research Database (Denmark)

Ferapontova, Elena; Hansen, Majken Nørgaard; Saunders, Aaron Marc

2010-01-01

A fast and sensitive electrochemical lipase-based sandwich hybridization assay for detection of attomole levels of DNA has been developed. A combination of magnetic beads, used for pre-concentration and bioseparation of the analyte with a lipase catalyst label allowed detection of DNA with a limi...

3' end labelling of RNA with /sup 32/P suitable for rapid gel sequencing

Energy Technology Data Exchange (ETDEWEB)

Winter, G; Brownlee, G G [Medical Research Council, Cambridge (UK)

1978-09-01

A new general method of labelling the 2', 3'-diol end of RNA with /sup 32/P has been devised suitable for gel sequencing. Poly(A) polymerase (E.coli) is incubated with the RNA and limiting amounts of ..cap alpha..-/sup 32/P-ATP. The mono-addition product is then cleaved with periodate and ..beta..-eliminated with aniline, leaving the RNA terminally labelled with 3'/sup 32/P-phosphate. When applied to a model compound, tRNAsup(Phe) from E. coli, over 28 residues could be read from the 3' end.

Single-label kinase and phosphatase assays for tyrosine phosphorylation using nanosecond time-resolved fluorescence detection.

Science.gov (United States)

Sahoo, Harekrushna; Hennig, Andreas; Florea, Mara; Roth, Doris; Enderle, Thilo; Nau, Werner M

2007-12-26

The collision-induced fluorescence quenching of a 2,3-diazabicyclo[2.2.2]oct-2-ene-labeled asparagine (Dbo) by hydrogen atom abstraction from the tyrosine residue in peptide substrates was introduced as a single-labeling strategy to assay the activity of tyrosine kinases and phosphatases. The assays were tested for 12 different combinations of Dbo-labeled substrates and with the enzymes p60c-Src Src kinase, EGFR kinase, YOP protein tyrosine phosphatase, as well as acid and alkaline phosphatases, thereby demonstrating a broad application potential. The steady-state fluorescence changed by a factor of up to 7 in the course of the enzymatic reaction, which allowed for a sufficient sensitivity of continuous monitoring in steady-state experiments. The fluorescence lifetimes (and intensities) were found to be rather constant for the phosphotyrosine peptides (ca. 300 ns in aerated water), while those of the unphosphorylated peptides were as short as 40 ns (at pH 7) and 7 ns (at pH 13) as a result of intramolecular quenching. Owing to the exceptionally long fluorescence lifetime of Dbo, the assays were alternatively performed by using nanosecond time-resolved fluorescence (Nano-TRF) detection, which leads to an improved discrimination of background fluorescence and an increased sensitivity. The potential for inhibitor screening was demonstrated through the inhibition of acid and alkaline phosphatases by molybdate.

Advanced Glycation End-Products Induce Apoptosis of Vascular Smooth Muscle Cells: A Mechanism for Vascular Calcification

Directory of Open Access Journals (Sweden)

Sayo Koike

2016-09-01

Full Text Available Vascular calcification, especially medial artery calcification, is associated with cardiovascular death in patients with diabetes mellitus and chronic kidney disease (CKD. To determine the underlying mechanism of vascular calcification, we have demonstrated in our previous report that advanced glycation end-products (AGEs stimulated calcium deposition in vascular smooth muscle cells (VSMCs through excessive oxidative stress and phenotypic transition into osteoblastic cells. Since AGEs can induce apoptosis, in this study we investigated its role on VSMC apoptosis, focusing mainly on the underlying mechanisms. A rat VSMC line (A7r5 was cultured, and treated with glycolaldehyde-derived AGE-bovine serum albumin (AGE3-BSA. Apoptotic cells were identified by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL staining. To quantify apoptosis, an enzyme-linked immunosorbent assay (ELISA for histone-complexed DNA fragments was employed. Real-time PCR was performed to determine the mRNA levels. Treatment of A7r5 cells with AGE3-BSA from 100 µg/mL concentration markedly increased apoptosis, which was suppressed by Nox inhibitors. AGE3-BSA significantly increased the mRNA expression of NAD(PH oxidase components including Nox4 and p22phox, and these findings were confirmed by protein levels using immunofluorescence. Dihydroethidisum assay showed that compared with cBSA, AGE3-BSA increased reactive oxygen species level in A7r5 cells. Furthermore, AGE3-induced apoptosis was significantly inhibited by siRNA-mediated knockdown of Nox4 or p22phox. Double knockdown of Nox4 and p22phox showed a similar inhibitory effect on apoptosis as single gene silencing. Thus, our results demonstrated that NAD(PH oxidase-derived oxidative stress are involved in AGEs-induced apoptosis of VSMCs. These findings might be important to understand the pathogenesis of vascular calcification in diabetes and CKD.

Sperm-macrophage interaction in the mouse: a quantitative assay in vitro using 111indium oxine-labeled sperm

International Nuclear Information System (INIS)

Olive, D.L.; Weinberg, J.B.; Haney, A.F.

1987-01-01

The role of reproductive tract macrophages in contraception and reproductive failure has become widely recognized. However, in vitro analysis of sperm phagocytosis by macrophages has relied upon a semi-quantitative method of sperm counting that is of limited accuracy and reproducibility. We have developed an assay using murine sperm labeled with 111 indium oxine, and results indicate the labeling to be rapid and efficient. Incorporation of 111 indium into sperm increased the dose and sperm concentration and reached 90% maximal uptake after 15 min incubation, with maximal uptake occurring at 30 min. No decrease in sperm motility was noted with levels of oxine in excess of those required for significant labeling. Maximal labeling efficiency occurred in phosphate-buffered saline (PBS), with Dulbecco's modified Eagle's medium (DMEM) + 10% adult bovine serum (ABS) producing significantly less uptake. Label dissociation was detectable in PBS at room temperature, but at 37 degrees C in DMEM + 10% ABS, loss of label occurred at a rate of 23.5%/h. Addition of labeled sperm to murine macrophage monolayers under optimal conditions resulted in uptake of 111 indium by macrophages, while free label was unincorporated. Results indicated assay specificity for macrophage-limited uptake, with insignificant label uptake by nonphagocytic murine fibroblasts and better sensitivity than sperm counting. Macrophages from Bacillus Calmette-Guerin (BCG)-infected mice resulted in a decrease in sperm uptake. Female macrophages showed greater capacity for sperm uptake than those of the male mouse. These initial studies demonstrated the utility of this model system in enhancing the understanding of sperm-macrophage interaction in the female reproductive tract

Solid phase radioimmunoassays using labelled antibodies: a conceptual framework for designing assays

International Nuclear Information System (INIS)

Kalmakoff, J.; Parkinson, A.J.; Crawford, A.M.; Williams, B.R.G.

1977-01-01

A simple theoretical model for the antigen-antibody reaction is presented and used to evaluate the optimum conditions for designing solid phase radioimmunoassays (RIA) using labelled antibodies. Both theoretical and experimental data are presented, using a wide variety of antigens and their corresponding antibodies. The types of RIA described include the direct, the indirect, the direct sandwich assays for detecting either antigen or antibody. The experimental results confirm in a semiquantitative manner that the greatest sensitivity of the RIA is achieved when the smallest amount of labelled antibody is used, that whenever possible the antigen/antibody ratio should be greater than unity(>1), and that the formation of the antigen-antibody complex is dependent on the mass action effect

Divalent metal ion differentially regulates the sequential nicking reactions of the GIY-YIG homing endonuclease I-BmoI.

Directory of Open Access Journals (Sweden)

Benjamin P Kleinstiver

Full Text Available Homing endonucleases are site-specific DNA endonucleases that function as mobile genetic elements by introducing double-strand breaks or nicks at defined locations. Of the major families of homing endonucleases, the modular GIY-YIG endonucleases are least understood in terms of mechanism. The GIY-YIG homing endonuclease I-BmoI generates a double-strand break by sequential nicking reactions during which the single active site of the GIY-YIG nuclease domain must undergo a substantial reorganization. Here, we show that divalent metal ion plays a significant role in regulating the two independent nicking reactions by I-BmoI. Rate constant determination for each nicking reaction revealed that limiting divalent metal ion has a greater impact on the second strand than the first strand nicking reaction. We also show that substrate mutations within the I-BmoI cleavage site can modulate the first strand nicking reaction over a 314-fold range. Additionally, in-gel DNA footprinting with mutant substrates and modeling of an I-BmoI-substrate complex suggest that amino acid contacts to a critical GC-2 base pair are required to induce a bottom-strand distortion that likely directs conformational changes for reaction progress. Collectively, our data implies mechanistic roles for divalent metal ion and substrate bases, suggesting that divalent metal ion facilitates the re-positioning of the GIY-YIG nuclease domain between sequential nicking reactions.

Label-Free, LC-MS-Based Assays to Quantitate Small-Molecule Antagonist Binding to the Mammalian BLT1 Receptor.

Science.gov (United States)

Chen, Xun; Stout, Steven; Mueller, Uwe; Boykow, George; Visconti, Richard; Siliphaivanh, Phieng; Spencer, Kerrie; Presland, Jeremy; Kavana, Michael; Basso, Andrea D; McLaren, David G; Myers, Robert W

2017-08-01

We have developed and validated label-free, liquid chromatography-mass spectrometry (LC-MS)-based equilibrium direct and competition binding assays to quantitate small-molecule antagonist binding to recombinant human and mouse BLT1 receptors expressed in HEK 293 cell membranes. Procedurally, these binding assays involve (1) equilibration of the BLT1 receptor and probe ligand, with or without a competitor; (2) vacuum filtration through cationic glass fiber filters to separate receptor-bound from free probe ligand; and (3) LC-MS analysis in selected reaction monitoring mode for bound probe ligand quantitation. Two novel, optimized probe ligands, compounds 1 and 2, were identified by screening 20 unlabeled BLT1 antagonists for direct binding. Saturation direct binding studies confirmed the high affinity, and dissociation studies established the rapid binding kinetics of probe ligands 1 and 2. Competition binding assays were established using both probe ligands, and the affinities of structurally diverse BLT1 antagonists were measured. Both binding assay formats can be executed with high specificity and sensitivity and moderate throughput (96-well plate format) using these approaches. This highly versatile, label-free method for studying ligand binding to membrane-associated receptors should find broad application as an alternative to traditional methods using labeled ligands.

Bioactivity assays and application of 125I labeled human mouse chimeric anti-CD22 monoclonal antibody SM03

International Nuclear Information System (INIS)

Lu Pingping; Meng Zhiyun; Dou Guifang; Wu Yingliang; Wang Minwei

2008-01-01

To investigate the bioactivity and application of 125 I labeled human mouse chimeric monoclonal SM03, SM03 was labeled with 125 I using Indogen method. The labeled mixture was purified by Sephacryl S-300 HR separation chromospectry. The purity and concentration of separated fractions were determined by HPLC and Protein Assay Kit, respectively. Competitive binding method and ELISA method were used for bioactivity assays. 125 I-SM03 was applied to screen cell lines which express the most abundant CD22 antigen. The purity and recovery of 125 I-SM03 were >99% and >47%, respectively. The bioactivity of 125 I- SM03 and SM03 hasn't significant difference in statistics. Ramos cell line had the strongest special radioactivity when 125 I-SM03 bound with in Raji, Daudi and Ramos cell lines. Indogen method is a good way to label Human mouse chimeric anti-CD22 monoclonal antibody SM03 and the label will not affect the activity of SM03. The 125 I-SM03 not only can be used for detect agent, but also may be put into market for NHL therapy. (authors)

End-labeling of peptide nucleic acid with osmium complex. Voltammetry at carbon and mercury electrodes

Czech Academy of Sciences Publication Activity Database

Paleček, Emil; Trefulka, Mojmír; Fojta, Miroslav

2009-01-01

Roč. 11, č. 2 (2009), s. 359-362 ISSN 1388-2481 R&D Projects: GA AV ČR(CZ) KAN400310651; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : peptide nucleic acid end-labeling * osmium tetroxide complexes * electroactive labels Subject RIV: BO - Biophysics Impact factor: 4.243, year: 2009

Pangahävitaja Leeson : "Ma kahetsen" / Nick Leeson ; interv. Argo Ideon

Index Scriptorium Estoniae

Leeson, Nick

2007-01-01

Briti börsimaakler Nick Leeson, kes pankrotistas Baringsi panga ning hävitas 17 miljardit krooni, selgitab, miks ta ei suutnud oma tegevust lõpetada ka siis kui kahjud olid kasvanud juba hiigelsuureks

Radiochemical plasma salicylamide assay using ring-labeled tritiated salicylamide

Energy Technology Data Exchange (ETDEWEB)

Stella, V J; Varia, S A; Riedy, M

1979-05-01

A rat plasma salicylamide assay was developed using ring-labeled tritiated salicylamide, synthesized by reacting salicylamide with tritium oxide in the presence of heptafluorobutyric acid. The reaction yielded /sup 3/H-salicylamide of specific activity up to 8.41 mCi/mmole, 60% yield. Plasma containing /sup 3/H-salicylamide and its metabolites was extracted with a toluene-based scintillation fluid, which was subsequently counted. Specificity for free salicylamide was demonstrated by radiochemical and standard fluorescence plasma salicylamide level-time curves. Specificity resulted from nonextraction of the salicylamide sulfate and glucuronide metabolites. Sulfatase and beta-glucuronidase treatment allowed the analysis of plasma sulfate and glucuronide conjugates as free salicylamide. This procedure should be effective for the analysis of salicylamide and its metabolites in the presence of similar phenolic compounds.

Leishmania diagnostic and identification py using 32P labelled DNA probes

International Nuclear Information System (INIS)

Andrade, Antero Silva Ribeiro de; Melo, Maria Norma de

1999-10-01

P 32 labelled DNA probes are valious instruments for the parasitic diseases by using hybridization reaction. In this paper we describe the methodology and present the foundations for the radioactive probes production, based on the kinetoplast DNA (kDNA), for the Leishmania diagnostic an identification. We also describe the kDNA purification protocol from Leishmania reference cepa, the process of P 32 labelling of the kDNA by using the nick translation method, gathering, sample preparation and treatment, the optimum conditions for the hybridization reaction and the procedures for the autoradiography

Hybrid male sterility is caused by mitochondrial DNA deletion.

Science.gov (United States)

Hayashida, Kenji; Kohno, Shigeru

2009-07-01

Although it is known that the hybrid male mouse is sterile just like any other animal's heterogametic sex, the reason why only the male germ cells are impaired has yet to be discovered. TdT-mediated dUTP nick end labeling assay using a confocal fluorescence microscope and DNA fragmentation assay of hybrid testis indicated destruction of the mitochondrial DNA (mtDNA) rather than the nuclear DNA. Previously we reported that maternal mtDNA inheritance is through selective sperm mtDNA elimination based on the sperm factor and two egg factors, and expression of these three factors was recognized in the hybrid testis. It was thereby assumed that mtDNA destruction caused by the expression of maternal mtDNA inheritance system in male germ cells is implicated in the hybrid male sterility of mice.

Quantitation of biotinylated compounds by a solid-phase assay using a /sup 125/I-labelled biotin derivative

Energy Technology Data Exchange (ETDEWEB)

Smith, P J; Warren, R M; Holt, C von

1987-05-11

The biotin analogue biotinylglycyltyrosine has been synthesized and labelled to a specific activity of 2000 Ci/mmol with /sup 125/I. This analogue has been used in conjunction with immobilized streptavidin in an assay which detects as little as 1 fmol biotin or biotinylated molecules in solution. The determination of biotinylated insulin in a tissue extract and the quantitation of a transcription assay are given as examples. (Auth.). 12 refs.; 4 figs.; 3 tabs.

A label-free, fluorescence based assay for microarray

Science.gov (United States)

Niu, Sanjun

DNA chip technology has drawn tremendous attention since it emerged in the mid 90's as a method that expedites gene sequencing by over 100-fold. DNA chip, also called DNA microarray, is a combinatorial technology in which different single-stranded DNA (ssDNA) molecules of known sequences are immobilized at specific spots. The immobilized ssDNA strands are called probes. In application, the chip is exposed to a solution containing ssDNA of unknown sequence, called targets, which are labeled with fluorescent dyes. Due to specific molecular recognition among the base pairs in the DNA, the binding or hybridization occurs only when the probe and target sequences are complementary. The nucleotide sequence of the target is determined by imaging the fluorescence from the spots. The uncertainty of background in signal detection and statistical error in data analysis, primarily due to the error in the DNA amplification process and statistical distribution of the tags in the target DNA, have become the fundamental barriers in bringing the technology into application for clinical diagnostics. Furthermore, the dye and tagging process are expensive, making the cost of DNA chips inhibitive for clinical testing. These limitations and challenges make it difficult to implement DNA chip methods as a diagnostic tool in a pathology laboratory. The objective of this dissertation research is to provide an alternative approach that will address the above challenges. In this research, a label-free assay is designed and studied. Polystyrene (PS), a commonly used polymeric material, serves as the fluorescence agent. Probe ssDNA is covalently immobilized on polystyrene thin film that is supported by a reflecting substrate. When this chip is exposed to excitation light, fluorescence light intensity from PS is detected as the signal. Since the optical constants and conformations of ssDNA and dsDNA (double stranded DNA) are different, the measured fluorescence from PS changes for the same

A radiolabel-release microwell assay for proteolytic enzymes present in cell culture media

International Nuclear Information System (INIS)

Rucklidge, G.J.; Milne, G.

1990-01-01

A modified method for the measurement of proteolytic enzyme activity in cell culture-conditioned media has been developed. Using the release of 3H-labeled peptides from 3H-labeled gelatin the method is performed in microwell plates. The substrate is insolubilized and attached to the wells by glutaraldehyde treatment, thus eliminating the need for a precipitation step at the end of the assay. The assay is sensitive, reproducible, and convenient for small sample volumes. The effect of different protease inhibitors on activity can be assessed rapidly allowing an early characterization of the enzyme. It can also be adapted to microplate spectrophotometric analysis by staining residual substrate with Coomassie blue

[3H]uridine uptake by target monolayers as a terminal label in an in vitro cell-mediated cytotoxicity assay

International Nuclear Information System (INIS)

Smith, G.; Nicklin, S.

1979-01-01

A terminal labelling method is described for measuring cell-mediated cytotoxicity based on the ability of surviving target cells to incorporate [ 3 H]uridine into their RNA precursor pools. Parameters of the system were examined using whole and damaged embryonic mouse fibroblast monolayers. This assay is less laborious than direct cell counting and gives increased sensitivity at low target to effector cell ratios. The labelling time is short and, unlike similar techniques, it allows target cell monolayers to remain intact after completion of the radioassay and available for histological examination. This is important where heterogeneous target populations are employed since it allows assessment of differential cell killing and eliminates the need for duplicate cultures. The assay was used in conjunction with a well defined mouse popliteal lymph node assay to investigate the appearance of cytotoxic cells during a localised graft versus host response. Results showed a direct correlation between proliferative index and the development of highly specific cell-mediated cytotoxicity. (Auth.)

A novel colloidal gold labeled antigen for the detection of Deoxynivalenol using an immunochromatographic assay method

Science.gov (United States)

Jin, Yu; Liu, Renrong; Zhu, Lixin; Chen, Zhenzhen

2017-11-01

In this paper, an immunochromatographic assay card was developed for the detection of DON in feed and cereals using a novel colloidal gold labeling method. For the colloidal gold immunochromatographic rapid detection (GICD) card, a monoclonal antibody DON-mAb and a goat anti-chicken IgY were drawn on NC membrane as the test line (T line) and the control line (C line) respectively. A gold labeled DON-CBSA conjugate and a gold labeled chicken IgY were sprayed onto the conjugate pad. The GICD card has cut-off levels of 50ng/mL for DON, which is invulnerable to matrix interference, and applicable to a wide range of samples. The GICD detecting results of feed and grain samples were compared with the results of ELISA testing, which showed good consistency.

A label-free luminescent switch-on assay for ATP using a G-quadruplex-selective iridium(III) complex.

Science.gov (United States)

Leung, Ka-Ho; Lu, Lihua; Wang, Modi; Mak, Tsun-Yin; Chan, Daniel Shiu-Hin; Tang, Fung-Kit; Leung, Chung-Hang; Kwan, Hiu-Yee; Yu, Zhiling; Ma, Dik-Lung

2013-01-01

We report herein the G-quadruplex-selective property of a luminescent cyclometallated iridium(III) complex for the detection of adenosine-5'-triphosphate (ATP) in aqueous solution. The ATP-binding aptamer was employed as the ATP recognition unit, while the iridium(III) complex was used to monitor the formation of the G-quadruplex structure induced by ATP. The sensitivity and fold enhancement of the assay were higher than those of the previously reported assay using the organic dye crystal violet as a fluorescent probe. This label-free luminescent switch-on assay exhibits high sensitivity and selectivity towards ATP with a limit of detection of 2.5 µM.

A label-free luminescent switch-on assay for ATP using a G-quadruplex-selective iridium(III complex.

Directory of Open Access Journals (Sweden)

Ka-Ho Leung

Full Text Available We report herein the G-quadruplex-selective property of a luminescent cyclometallated iridium(III complex for the detection of adenosine-5'-triphosphate (ATP in aqueous solution. The ATP-binding aptamer was employed as the ATP recognition unit, while the iridium(III complex was used to monitor the formation of the G-quadruplex structure induced by ATP. The sensitivity and fold enhancement of the assay were higher than those of the previously reported assay using the organic dye crystal violet as a fluorescent probe. This label-free luminescent switch-on assay exhibits high sensitivity and selectivity towards ATP with a limit of detection of 2.5 µM.

Trapping and breaking of in vivo nicked DNA during pulsed-field gel electrophoresis

Science.gov (United States)

Khan, Sharik R.; Kuzminov, Andrei

2013-01-01

Pulsed field gel electrophoresis (PFGE) offers a high-resolution approach to quantify chromosomal fragmentation in bacteria, measured as percent of chromosomal DNA entering the gel. The degree of separation in PFG depends upon the size of DNA, as well as various conditions of electrophoresis, such as electric field strength (FS), time of electrophoresis, switch time and buffer composition. Here we describe a new parameter, the structural integrity of the sample DNA itself, that influences its migration through PFGs. We show that sub-chromosomal fragments containing both spontaneous and DNA damage-induced nicks are prone to breakage during PFGE. Such breakage at single strand interruptions results in artefactual decrease in molecular weight of linear DNA making accurate determination of the number of double strand breaks difficult. While breakage of nicked sub-chromosomal fragments is FS-independent, some high molecular weight sub-chromosomal fragments are also trapped within wells under the standard PFGE conditions. This trapping can be minimized by lowering the field strength and increasing the time of electrophoresis. We discuss how breakage of nicked DNA may be mechanistically linked to trapping. Our results suggest how to optimize conditions for PFGE when quantifying chromosomal fragmentation induced by DNA damage. PMID:23770235

Comparison of antibacterial activities of root-end filling materials by an agar diffusion assay and Alamar blue assay

Directory of Open Access Journals (Sweden)

Tsui-Hsien Huang

2012-12-01

Conclusion: We concluded that both the agar diffusion test and Alamar blue assay gave comparable findings of assessing the antimicrobial activity present in root-end filling materials. No antimicrobial activity was detected for mineral trioxide aggregate, calcium silicate cement, or amalgam after coming into contact with S. mutans, S. sanguinis and E. coli. IRM showed high antimicrobial activity against both S. sanguinis and E. coli.

Adhesion kinetics of human primary monocytes, dendritic cells, and macrophages: Dynamic cell adhesion measurements with a label-free optical biosensor and their comparison with end-point assays.

Science.gov (United States)

Orgovan, Norbert; Ungai-Salánki, Rita; Lukácsi, Szilvia; Sándor, Noémi; Bajtay, Zsuzsa; Erdei, Anna; Szabó, Bálint; Horvath, Robert

2016-09-01

Monocytes, dendritic cells (DCs), and macrophages (MFs) are closely related immune cells that differ in their main functions. These specific functions are, to a considerable degree, determined by the differences in the adhesion behavior of the cells. To study the inherently and essentially dynamic aspects of the adhesion of monocytes, DCs, and MFs, dynamic cell adhesion assays were performed with a high-throughput label-free optical biosensor [Epic BenchTop (BT)] on surfaces coated with either fibrinogen (Fgn) or the biomimetic copolymer PLL-g-PEG-RGD. Cell adhesion profiles typically reached their maximum at ∼60 min after cell seeding, which was followed by a monotonic signal decrease, indicating gradually weakening cell adhesion. According to the biosensor response, cell types could be ordered by increasing adherence as monocytes, MFs, and DCs. Notably, all three cell types induced a larger biosensor signal on Fgn than on PLL-g-PEG-RGD. To interpret this result, the molecular layers were characterized by further exploiting the potentials of the biosensor: by measuring the adsorption signal induced during the surface coating procedure, the authors could estimate the surface density of adsorbed molecules and, thus, the number of binding sites potentially presented for the adhesion receptors. Surfaces coated with PLL-g-PEG-RGD presented less RGD sites, but was less efficient in promoting cell spreading than those coated with Fgn; hence, other binding sites in Fgn played a more decisive role in determining cell adherence. To support the cell adhesion data obtained with the biosensor, cell adherence on Fgn-coated surfaces 30-60 min after cell seeding was measured with three complementary techniques, i.e., with (1) a fluorescence-based classical adherence assay, (2) a shear flow chamber applying hydrodynamic shear stress to wash cells away, and (3) an automated micropipette using vacuum-generated fluid flow to lift cells up. These techniques confirmed the results

Bacterial reduction in genotoxicity of Direct Red 28 dye.

Science.gov (United States)

Bafana, Amit; Jain, Minakshi; Agrawal, Gaurav; Chakrabarti, Tapan

2009-03-01

Direct Red 28 (DR28) is a benzidine-based azo dye widely used in several countries. It has also been a subject of intense research for its anti-prion activity. Like other benzidine-based azo dyes, it is also carcinogenic and toxic. However, there are very few studies addressing its detoxification. In the present study, a Bacillus velezensis strain was used for detoxification of DR28. Toxicity was checked by a battery of highly sensitive genotoxicity assays like comet assay, DNA ladder formation, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay and flow cytometric Annexin V binding assay. HL-60 cell line was used as the test system. All the assays showed an initial increase in toxicity upon biodegradation due to release of mutagenic products, like benzidine and 4-aminobiphenyl, from the dye. These intermediates caused significant DNA damage and induced apoptosis in HL-60 cells. Then the culture degraded these mutagenic intermediates, due to which the toxicity was reduced gradually, finally resulting in nearly complete detoxification.

Label-free DNA hybridization detection and single base-mismatch discrimination using CE-ICP-MS assay.

Science.gov (United States)

Li, Yan; Sun, Shao-kai; Yang, Jia-lin; Jiang, Yan

2011-12-07

Detecting a specific DNA sequence and discriminating single base-mismatch is critical to clinical diagnosis, paternity testing, forensic sciences, food and drug industry, pathology, genetics, environmental monitoring, and anti-bioterrorism. To this end, capillary electrophoresis (CE) coupled with the inductively coupled plasma mass spectrometry (ICP-MS) method is developed using the displacing interaction between the target ssDNA and the competitor Hg(2+) for the first time. The thymine-rich capture ssDNA 1 is interacted with the competitor Hg(2+), forming an assembled complex in a hairpin-structure between the thymine bases arrangement at both sides of the capture ssDNA 1. In the presence of a target ssDNA with stronger affinity than that of the competitor Hg(2+), the energetically favorable hybridization between capture ssDNA 1 and the target ssDNA destroys the hairpin-structure and releases the competitor as free Hg(2+), which was then read out and accurately quantified by CE-ICP-MS assay. Under the optimal CE separation conditions, free Hg(2+) ions and its capture ssDNA 1 adduct were baseline separated and detected on-line by ICP-MS; the increased peak intensity of free Hg(2+) against the concentration of perfectly complementary target ssDNA was linear over the concentration range of 30-600 nmol L(-1) with a limit of detection of 8 nmol L(-1) (3s, n = 11) in the pre-incubated mixture containing 1 μmol L(-1) Hg(2+) and 0.2 μmol L(-1) capture ssDNA 1. This new assay method is simple in design since any target ssDNA binding can in principle result in free Hg(2+) release by 6-fold Hg(2+) signal amplification, avoiding oligonucleotide labeling or assistance by excess signal transducer and signal reporter to read out the target. Due to element-specific detection of ICP-MS in our assay procedure, the interference from the autofluorescence of substrata was eliminated.

Ligand-protein conjugated quantification assay by UV spectrophotometry in 99mTc indirect labeling

International Nuclear Information System (INIS)

Basualdo, Daniel A.; Rabiller, Graciela; Poch, Carolina; El Tamer, Elias A.

2009-01-01

Objective: Quantify IgG-HYNIC conjugated for obtaining substitution ratio and as a chemical quality control for 99m Tc labeling of this immunoglobulin. Introduction: The Operational Guidance on Hospital Radiopharmacy by IAEA states that the procedures performed in a Radiopharmacy Laboratory fall into three operational levels. At present, Nuclear Medicine Centre of 'Hospital de Clinicas' has an operational level 2b which requires the preparation of radiopharmaceuticals from approved reagent kits and radionuclide generators, and labeling of autologous blood cells. Centre's goal is to reach an operational level 3a, which allows us to compounding radiopharmaceuticals from drugs and radionuclides for diagnosis; modification to existing commercial kits; related research and development. In approach of that goal, we addressed the optimization of conjugation of proteins and peptides with S-HYNIC so as to bring about the procedures involved. In this work, was conjugated nonspecific polyclonal immunoglobulin G (IgG) with S-HYNIC. Our interest was focused in calculate how many HYNIC groups were incorporated per IgG molecule so that in later stages can be obtained a correlate with labeling efficiency. Materials and methods: A sample of IgG-HYNIC conjugate of 0.2 ml was diluted in 4 ml of benzaldehyde o-sulfonic acid (1 mg / ml, 0.1 M NaAc, pH 4.7). The reaction was incubated at room temperature overnight in darkness. As a negative control took 0.2 ml of IgG-HYNIC conjugate in 4 ml of NaAc buffer 0.1 M. 3 ml of benzaldehyde o-sulfonic acid (1 mg / ml 0.1 M NaAc, pH 4.7) was used as blank. The absorption of the hydrazone was read at 343 nm. The hydrazine concentration was calculated using a molar extinction coefficient ε (343 nm) 17000 M-1cm-1. Results: Molar substitution ratio (MSR) was calculated. The MSR indicates the number of HYNIC groups incorporated in the IgG-HYNIC conjugate determined by the spectrophotometric assay. Conclusions: In labeling with a bifunctional

Labelled Substrate Assays of Anticholinesterase Activity in Hungarian Water Bodies

International Nuclear Information System (INIS)

Horváth, L.

1981-01-01

At Budapest the River Danube divides into two branches. The left branch called Soroksár-Danube is regulated by locks. The water level fluctuation on this quasi lake is only 50-60 cm. Along the 57 km long branch there are big industries, intensive agricultural areas and holiday resorts. The water is used among others for irrigation, for fishponds and for water sport. The pesticides applied on the neighbouring arable land and the insecticides used for mosquito controlling may pollute the water. Little is known about the fate of insecticides in water and about their impact on the aquatic biota. In June 1978 a monitoring programme of cholinesterase inhibiting pesticide residues was launched on a section of River Danube near to Budapest. Important purpose of the investigations was to test the labelled substrate enzyme inhibition assay as monitoring method for pesticide residues

Labelled Substrate Assays of Anticholinesterase Activity in Hungarian Water Bodies

Energy Technology Data Exchange (ETDEWEB)

Horváth, L. [Institute of Isotopes of the Hungarian Academy of Sciences, Budapest (Hungary)

1981-05-15

At Budapest the River Danube divides into two branches. The left branch called Soroksár-Danube is regulated by locks. The water level fluctuation on this quasi lake is only 50-60 cm. Along the 57 km long branch there are big industries, intensive agricultural areas and holiday resorts. The water is used among others for irrigation, for fishponds and for water sport. The pesticides applied on the neighbouring arable land and the insecticides used for mosquito controlling may pollute the water. Little is known about the fate of insecticides in water and about their impact on the aquatic biota. In June 1978 a monitoring programme of cholinesterase inhibiting pesticide residues was launched on a section of River Danube near to Budapest. Important purpose of the investigations was to test the labelled substrate enzyme inhibition assay as monitoring method for pesticide residues.

End-specific strategies of attachment of long double stranded DNA onto gold-coated nanofiber arrays

International Nuclear Information System (INIS)

Peckys, Diana B; De Jonge, Niels; Simpson, Michael L; McKnight, Timothy E

2008-01-01

We report the effective and site-specific binding of long double stranded (ds)DNA to high aspect ratio carbon nanofiber arrays. The carbon nanofibers were first coated with a thin gold layer to provide anchorage for two controllable binding methods. One method was based on the direct binding of thiol end-labeled dsDNA. The second and enhanced method used amine end-labeled dsDNA bound with crosslinkers to a carboxyl-terminated self-assembled monolayer. The bound dsDNA was first visualized with a fluorescent, dsDNA-intercalating dye. The specific binding onto the carbon nanofiber was verified by a high resolution detection method using scanning electron microscopy in combination with the binding of neutravidin-coated fluorescent microspheres to the immobilized and biotinylated dsDNA. Functional activity of thiol end-labeled dsDNA on gold-coated nanofiber arrays was verified with a transcriptional assay, whereby Chinese hamster lung cells (V79) were impaled upon the DNA-modified nanofibers and scored for transgene expression of the tethered template. Thiol end-labeled dsDNA demonstrated significantly higher expression levels than nanofibers prepared with control dsDNA that lacked a gold-binding end-label. Employing these site-specific and robust techniques of immobilization of dsDNA onto nanodevices can be of advantage for the study of DNA/protein interactions and for gene delivery applications.

Nick Ransford: 'There is a job to do so let's get on with it'.

Science.gov (United States)

Ransford, Nick; Doherty, Ruth

2014-03-01

Nick Ransford is a consultant in special care dentistry at Birmingham Community Healthcare NHS Trust. He has over 25 years' experience working with adults with disabilities and medical conditions across the spectrum.

Isotopic methods or immuno diagnosis: The Radioimmunoassay and immunoradiometric assay

International Nuclear Information System (INIS)

Caso, R.

1997-01-01

This work offers an explanation about the more used isotopic techniques for immuno diagnosis: the radioimmunoassay (RIA) and immunoradiometric assay (IRMA). It describes the basic principles of these assays, the antigen-antibody reaction, the radioiodination methods with I-125 for antigens and antibodies, the purification and characterization of labelled compounds. On the order hand they present work gives a review of the methods for separate the bound and free fractions. At the end it offers the principles of the quality control of immunoassay and the future lines of research in the field of RIA and IRMA

Study of influence of catechins on bystander responses in alpha-particle radiobiological experiments using thin PADC films

Energy Technology Data Exchange (ETDEWEB)

Law, Y.L. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Yu, K.N., E-mail: peter.yu@cityu.edu.h [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong)

2009-10-15

In this study, Chinese hamster ovary (CHO) cells were cultured in custom-made petri dishes with thin PADC films as substrates. Alpha particles with energies of 5 MeV were then irradiated from the bottom of PADC films. The DNA strand breaks in the bystander cells induced by irradiation were quantified with the use of terminal dUTP transferase-mediated nick end-labeling (TUNEL) assay. To study the influence of catechins on the bystander responses, catechins were added into the medium before alpha-particle irradiation of the cells. Fewer DNA strand breaks in the bystander cells were observed. As catechins are ROS (reactive oxygen species)-scavengers, the studied bystander cells might have been protected from radiation through scavenging of ROS by catechins.

Study of influence of catechins on bystander responses in alpha-particle radiobiological experiments using thin PADC films

International Nuclear Information System (INIS)

Law, Y.L.; Yu, K.N.

2009-01-01

In this study, Chinese hamster ovary (CHO) cells were cultured in custom-made petri dishes with thin PADC films as substrates. Alpha particles with energies of 5 MeV were then irradiated from the bottom of PADC films. The DNA strand breaks in the bystander cells induced by irradiation were quantified with the use of terminal dUTP transferase-mediated nick end-labeling (TUNEL) assay. To study the influence of catechins on the bystander responses, catechins were added into the medium before alpha-particle irradiation of the cells. Fewer DNA strand breaks in the bystander cells were observed. As catechins are ROS (reactive oxygen species)-scavengers, the studied bystander cells might have been protected from radiation through scavenging of ROS by catechins.

Quantification and genome-wide mapping of DNA double-strand breaks.

Science.gov (United States)

Grégoire, Marie-Chantal; Massonneau, Julien; Leduc, Frédéric; Arguin, Mélina; Brazeau, Marc-André; Boissonneault, Guylain

2016-12-01

DNA double-strand breaks (DSBs) represent a major threat to the genetic integrity of the cell. Knowing both their genome-wide distribution and number is important for a better assessment of genotoxicity at a molecular level. Available methods may have underestimated the extent of DSBs as they are based on markers specific to those undergoing active repair or may not be adapted for the large diversity of naturally occurring DNA ends. We have established conditions for an efficient first step of DNA nick and gap repair (NGR) allowing specific determination of DSBs by end labeling with terminal transferase. We used DNA extracted from HeLa cells harboring an I-SceI cassette to induce a targeted nick or DSB and demonstrated by immunocapture of 3'-OH that a prior step of NGR allows specific determination of loci-specific or genome wide DSBs. This method can be applied to the global determination of DSBs using radioactive end labeling and can find several applications aimed at understanding the distribution and kinetics of DSBs formation and repair. Copyright © 2016 Elsevier B.V. All rights reserved.

Limited numbers of apoptotic cells in fresh paraffin embedded bone marrow samples of patients with myelodysplastic syndrome

NARCIS (Netherlands)

Brada, SJL; van de Loosdrecht, AA; Koudstaal, J; de Wolf, JTM; Vellenga, E

In myelodysplasia (MDS) the precise mechanism of ineffective erythropoiesis is not fully elucidated, but it is suggested that apoptosis may contribute to this process. We performed TdT-mediated dUTP-nick end labelling (TUNEL) staining of paraffin embedded bone marrow specimens to assess the amount

Designs, formats and applications of lateral flow assay: A literature review

Directory of Open Access Journals (Sweden)

Muhammad Sajid

2015-11-01

Full Text Available This manuscript provides a brief overview of latest research involving the use of lateral flow assay for qualitative and quantitative analysis in different areas. The excellent features and versatility of detection formats make these strips an ideal choice for point of care applications. We outline and critically discuss detection formats, molecular recognition probes, labels, and detection systems used in lateral flow assay. Applications in different fields along with selected examples from the literature have been included to show analytical performance of these devices. At the end, we summarize accomplishments, weaknesses and future challenges in the area of lateral flow strips.

Nick Hornby’s A Long Way Down (2005 in the Transition from Book to Movie

Directory of Open Access Journals (Sweden)

Ömercan Tüm

2015-12-01

Full Text Available Nick Hornby’s A Long Way Down (2005 in the Transition from Book to movie Abstract Challenging and profound, Nick Hornby’s novel A Long Way Down (2005 is the story of four people failing to commit suicide. The protagonists are caught in an intricate web of relationships, disappointments and missed chances on their one-way journey to understand that “The cure for unhappiness is happiness” (Elizabeth McCracken. This paper aims at demonstrating that 2014 movie version directed by Pascal Chaumeil fails to capture the essence of the book and resorts to a number of radical changes which are only supposed to attract a larger audience, but do not necessarily send the same message as the novel.

Novel 3′-Processing Integrase Activity Assay by Real-Time PCR for Screening and Identification of HIV-1 Integrase Inhibitors

Directory of Open Access Journals (Sweden)

Supachai Sakkhachornphop

2015-01-01

Full Text Available The 3′-end processing (3′P of each viral long terminal repeat (LTR during human immunodeficiency virus type-1 (HIV-1 integration is a vital step in the HIV life cycle. Blocking the 3′P using 3′P inhibitor has recently become an attractive strategy for HIV-1 therapeutic intervention. Recently, we have developed a novel real-time PCR based assay for the detection of 3′P activity in vitro. The methodology usually involves biotinylated HIV-1 LTR, HIV-1 integrase (IN, and specific primers and probe. In this novel assay, we designed the HIV-1 LTR substrate based on a sequence with a homology to HIV-1 LTR labeled at its 3′ end with biotin on the sense strand. Two nucleotides at the 3′ end were subsequently removed by IN activity. Only two nucleotides labeled biotin were captured on an avidin-coated tube; therefore, inhibiting the binding of primers and probe results in late signals in the real-time PCR. This novel assay has successfully detected both the 3′P activity of HIV-1 IN and the anti-IN activity by Raltegravir and sodium azide agent. This real-time PCR assay has been shown to be effective and inexpensive for a high-throughput screening of novel IN inhibitors.

Fluorescence correlation spectroscopy analysis for accurate determination of proportion of doubly labeled DNA in fluorescent DNA pool for quantitative biochemical assays.

Science.gov (United States)

Hou, Sen; Sun, Lili; Wieczorek, Stefan A; Kalwarczyk, Tomasz; Kaminski, Tomasz S; Holyst, Robert

2014-01-15

Fluorescent double-stranded DNA (dsDNA) molecules labeled at both ends are commonly produced by annealing of complementary single-stranded DNA (ssDNA) molecules, labeled with fluorescent dyes at the same (3' or 5') end. Because the labeling efficiency of ssDNA is smaller than 100%, the resulting dsDNA have two, one or are without a dye. Existing methods are insufficient to measure the percentage of the doubly-labeled dsDNA component in the fluorescent DNA sample and it is even difficult to distinguish the doubly-labeled DNA component from the singly-labeled component. Accurate measurement of the percentage of such doubly labeled dsDNA component is a critical prerequisite for quantitative biochemical measurements, which has puzzled scientists for decades. We established a fluorescence correlation spectroscopy (FCS) system to measure the percentage of doubly labeled dsDNA (PDL) in the total fluorescent dsDNA pool. The method is based on comparative analysis of the given sample and a reference dsDNA sample prepared by adding certain amount of unlabeled ssDNA into the original ssDNA solution. From FCS autocorrelation functions, we obtain the number of fluorescent dsDNA molecules in the focal volume of the confocal microscope and PDL. We also calculate the labeling efficiency of ssDNA. The method requires minimal amount of material. The samples have the concentration of DNA in the nano-molar/L range and the volume of tens of microliters. We verify our method by using restriction enzyme Hind III to cleave the fluorescent dsDNA. The kinetics of the reaction depends strongly on PDL, a critical parameter for quantitative biochemical measurements. Copyright © 2013 Elsevier B.V. All rights reserved.

Site- and strand-specific nicking of DNA by fusion proteins derived from MutH and I-SceI or TALE repeats.

Science.gov (United States)

Gabsalilow, Lilia; Schierling, Benno; Friedhoff, Peter; Pingoud, Alfred; Wende, Wolfgang

2013-04-01

Targeted genome engineering requires nucleases that introduce a highly specific double-strand break in the genome that is either processed by homology-directed repair in the presence of a homologous repair template or by non-homologous end-joining (NHEJ) that usually results in insertions or deletions. The error-prone NHEJ can be efficiently suppressed by 'nickases' that produce a single-strand break rather than a double-strand break. Highly specific nickases have been produced by engineering of homing endonucleases and more recently by modifying zinc finger nucleases (ZFNs) composed of a zinc finger array and the catalytic domain of the restriction endonuclease FokI. These ZF-nickases work as heterodimers in which one subunit has a catalytically inactive FokI domain. We present two different approaches to engineer highly specific nickases; both rely on the sequence-specific nicking activity of the DNA mismatch repair endonuclease MutH which we fused to a DNA-binding module, either a catalytically inactive variant of the homing endonuclease I-SceI or the DNA-binding domain of the TALE protein AvrBs4. The fusion proteins nick strand specifically a bipartite recognition sequence consisting of the MutH and the I-SceI or TALE recognition sequences, respectively, with a more than 1000-fold preference over a stand-alone MutH site. TALE-MutH is a programmable nickase.

Perspectives on the ‘lens of risk’ interview series: interview with Nick Pidgeon

NARCIS (Netherlands)

Heyman, B.; Brown, P.

2012-01-01

This article is the first in a series which will appear in 2012 in the special issue series Health Care Through the `Lens of Risk'. It provides a quasi-verbatim transcript of an interview with Nick Pidgeon, one of the main contributors to the social science component of The Royal Society Risk Report

Phosphodiesterase-5 inhibitor sildenafil preconditions adult cardiac myocytes against necrosis and apoptosis. Essential role of nitric oxide signaling.

Science.gov (United States)

Das, Anindita; Xi, Lei; Kukreja, Rakesh C

2005-04-01

We investigated the effect of sildenafil in protection against necrosis or apoptosis in cardiomyocytes. Adult mouse ventricular myocytes were treated with sildenafil (1 or 10 microM) for 1 h before 40 min of simulated ischemia (SI). Necrosis was determined by trypan blue exclusion and lactate dehydrogenase release following SI alone or plus 1 or 18 h of reoxygenation (RO). Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated nick end labeling assay and mitochondrial membrane potential measured using a fluorescent probe 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1). Sildenafil reduced necrosis as indicated by decrease in trypan blue-positive myocytes and leakage of lactate dehydrogenase compared with untreated cells after either SI or SI-RO. The number of terminal deoxynucleotidyl transferase-mediated nick end labeling-positive myocytes or loss of JC-1 fluorescence following SI and 18 h of RO was attenuated in the sildenafil-treated group with concomitant inhibition of caspase 3 activity. An early increase in Bcl-2 to Bax ratio with sildenafil treatment was also observed in myocytes after SI-RO. The increase of Bcl-2 expression by sildenafil was inhibited by nitric-oxide synthase (NOS) inhibitor, L-nitro-amino-methyl-ester. The drug also enhanced mRNA and protein content of inducible NOS (iNOS) and endothelial NOS (eNOS) in the myocytes. Sildenafil-induced protection against necrosis and apoptosis was absent in the myocytes derived from iNOS knock-out mice and was attenuated in eNOS knock-out myocytes. The up-regulation of Bcl-2 expression by sildenafil was also absent in iNOS-deficient myocytes. Reverse transcription-PCR, Western blots, and immunohistochemical assay confirmed the expression of phosphodiesterase-5 in mouse cardiomyocytes. These data provide strong evidence for a direct protective effect of sildenafil against necrosis and apoptosis through NO signaling pathway. The results may have possible

CNS wound healing is severely depressed in metallothionein I- and II-deficient mice

DEFF Research Database (Denmark)

Penkowa, M; Carrasco, J; Giralt, M

1999-01-01

. In contrast to normal mice, at 20 dpl no wound healing had occurred. The rate of apoptosis, as determined by using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, was drastically increased in neurons of ipsilateral cortex of the MT-I+II null mice. Our results demonstrate that MT...

Radio Column Chromatographic Assay of H3-Labelled Substances

International Nuclear Information System (INIS)

Scharpenseel, H.W.; Menke, K.H.

1962-01-01

Combined radio-chromatographic investigations of H 3 -labelled substances are an integral part of the majority of biochemical experiments with H 3 -labelled compounds. H 3 -radio paper chromatography yields, in a scanner with a windowless flow counter, a counting efficiency of 0,5 -1,5%, depending largely on the thickness of the paper and the self-absorption of the labelled compound. The radio gas chromatography of tritiated compounds presents no major problem. Successful use is being made of a combination of a gas chromatograph with a flow ionization chamber and vibrating reed electrometer, a system originated by K. E. Wilzbach and P. Riessz, and improved by H. Dutton, L. Mason and L. Blair. Through the use of ''Teflon'' and silicone-rubber for the insulating parts of the flow ion chamber, it can be operated at close to 300 o C. Radio column chromatography with tritium holds little promise, when the column effluent is spread out as a shallow layer and slowly passes under a windowless flow counter or a scintillation counter, as was successfully tried with C 14 . Liquid scintillation spectrometry is likely to be the chosen method. Essentially, there are two different approaches feasible. These have been compared: 1. The column effluent is passed through a coil of plastic scintillator tubing, which is wound around a ''Plexiglas'' cylinder and placed in a bath of silicone oil in a light pipe with TiO 2 -reflector. Similarly, the HP-containing effluent can be directed through a test vial, filled - very much as in Steinberg's method - with plastic scintillator beads. These two approaches, that operate highly satisfactorily in the case of C 14 , offer low counting efficiencies of less than 1% for H 3 due to the unfavourable surface to volume ratio. 2. The column effluent is combined 1:30 with a mixture of 3:2 toluene/ethanol by the action of a magnet-vibrator before being assayed while passing through a K 40 -free glass - coiled between the analyser- and monitor

Labelling of. beta. -endorphin (. beta. -END) and. beta. -lipotropin (. beta. -LPH) by /sup 125/I

Energy Technology Data Exchange (ETDEWEB)

Deby-Dupont, G.; Joris, J.; Franchimont, P. (Universite de Liege (Belgique)); Reuter, A.M.; Vrindts-Gevaert, Y. (Institut des Radioelements, Fleurus (Belgique))

1983-01-01

5 ..mu..g of human ..beta..-endorphin were labelled with 2 mCi /sup 125/I by the chloramine T technique. After two gel filtrations on Sephadex G-15 and on Sephadex G-50 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer was obtained with a specific activity about 150 ..mu..Ci/..mu..g.Kept at + 4/sup 0/C, the tracer remained utilizable for 30 days without loss of immunoreactivity. The labelling with lactoperoxydase and the use of another gel filtration method (filtration on Aca 202) gave a /sup 125/I ..beta..-END tracer with the same immunoreactivity. The binding of this tracer to the antibody of an anti-..beta..-END antiserum diluted at 1/8000 was 32% with a non specific binding of 2%. 5 ..mu..g of human ..beta..-lipotropin were labelled with 0.5 mCi /sup 125/I by the lactoperoxydase method. After two gel filtrations on Sephadex G-25 and on Sephadex G-75 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer with a specific activity of 140 ..mu..Ci/..mu..g was obtained. It remained utilizable for 30 days when kept at + 4/sup 0/C. Gel filtration on Aca 202 did not give good purification, while gel filtration on Aca 54 was good but slower than on Sephadex G-75. The binding to antibody in absence of unlabelled ..beta..-LPH was 32% for an anti-..beta..-LPH antiserum diluted at 1/4000. The non specific binding was 2.5%.

DNA Packaging Specificity of Bacteriophage N15 with an Excursion into the Genetics of a Cohesive End Mismatch.

Directory of Open Access Journals (Sweden)

Michael Feiss

Full Text Available During DNA replication by the λ-like bacteriophages, immature concatemeric DNA is produced by rolling circle replication. The concatemers are processed into mature chromosomes with cohesive ends, and packaged into prohead shells, during virion assembly. Cohesive ends are generated by the viral enzyme terminase, which introduces staggered nicks at cos, an approx. 200 bp-long sequence containing subsites cosQ, cosN and cosB. Interactions of cos subsites of immature concatemeric DNA with terminase orchestrate DNA processing and packaging. To initiate DNA packaging, terminase interacts with cosB and nicks cosN. The cohesive ends of N15 DNA differ from those of λ at 2/12 positions. Genetic experiments show that phages with chromosomes containing mismatched cohesive ends are functional. In at least some infections, the cohesive end mismatch persists through cyclization and replication, so that progeny phages of both allelic types are produced in the infected cell. N15 possesses an asymmetric packaging specificity: N15 DNA is not packaged by phages λ or 21, but surprisingly, N15-specific terminase packages λ DNA. Implications for genetic interactions among λ-like bacteriophages are discussed.

Biodistribution of the 18F-labelled advanced glycation end products Nε-carboxymethyllysine (CML) and Nε-carboxyethyllysine (CEL)

International Nuclear Information System (INIS)

Bergmann, R.; Helling, R.; Henle, T.; Heichert, C.; Scheunemann, M.; Maeding, P.; Wittrisch, H.; Johannsen, B.

2002-01-01

After synthesis of fluorine-18 labelled analogues [ 18 F]fluorobenzoylation at the α-amino group, biodistribution and elimination of individual advanced glycation end products, namely N ε -carboxymethyllysine and N ε -carboxyethyllysine, was studied in comparison to lysine in rats after intravenous injection using positron emission tomography. (orig.)

Nicked apomyoglobin: a noncovalent complex of two polypeptide fragments comprising the entire protein chain.

Science.gov (United States)

Musi, Valeria; Spolaore, Barbara; Picotti, Paola; Zambonin, Marcello; De Filippis, Vincenzo; Fontana, Angelo

2004-05-25

Limited proteolysis of the 153-residue chain of horse apomyoglobin (apoMb) by thermolysin results in the selective cleavage of the peptide bond Pro88-Leu89. The N-terminal (residues 1-88) and C-terminal (residues 89-153) fragments of apoMb were isolated to homogeneity and their conformational and association properties investigated in detail. Far-UV circular dichroism (CD) measurements revealed that both fragments in isolation acquire a high content of helical secondary structure, while near-UV CD indicated the absence of tertiary structure. A 1:1 mixture of the fragments leads to a tight noncovalent protein complex (1-88/89-153, nicked apoMb), characterized by secondary and tertiary structures similar to those of intact apoMb. The apoMb complex binds heme in a nativelike manner, as given by CD measurements in the Soret region. Second-derivative absorption spectra in the 250-300 nm region provided evidence that the degree of exposure of Tyr residues in the nicked species is similar to that of the intact protein at neutral pH. Also, the microenvironment of Trp residues, located in positions 7 and 14 of the 153-residue chain of the protein, is similar in both protein species, as given by fluorescence emission data. Moreover, in analogy to intact apoMb, the nicked protein binds the hydrophobic dye 1-anilinonaphthalene-8-sulfonate (ANS). Taken together, our results indicate that the two proteolytic fragments 1-88 and 89-153 of apoMb adopt partly folded states characterized by sufficiently nativelike conformational features that promote their specific association and mutual stabilization into a nicked protein species much resembling in its structural features intact apoMb. It is suggested that the formation of a noncovalent complex upon fragment complementation can mimic the protein folding process of the entire protein chain, with the difference that the folding of the complementary fragments is an intermolecular process. In particular, this study emphasizes the

Securing wilderness landscapes in South Africa : Nick Steele, private wildlife conservancies and saving rhinos

NARCIS (Netherlands)

Wels,; H.,

2015-01-01

Private wildlife conservation is booming business in South Africa! Nick Steele stood at the cradle of this development in the politically turbulent 1970s and 1980s, by stimulating farmers in Natal (now KwaZulu-Natal) to pool resources in order to restore wilderness landscapes, but at the same time

In vitro assays for predicting tumor cell response to radiation by apoptotic pathways

International Nuclear Information System (INIS)

Algan, Oe.; Hanks, G.E.; Biade, S.; Chapman, J.D.

1995-01-01

Purpose: We had previously shown that the rate of spontaneous and radiation-induced apoptosis was significantly greater in well-differentiated compared to anaplastic Dunning prostate carcinomas. The goal of this study was to define the most useful assay for quantifying radiation-induced apoptotic cell death and to determine if measured rates of radiation-induced apoptosis in tumor cell populations can predict treatment outcome. Materials and Methods: The time course and extent of radiation-induced apoptosis after single doses of Cesium-137 gamma-rays were measured by five different assays. These included gross DNA degradation, nucleosome ladder formation, labeling of 3'-OH ends in DNA with an immunofluorescence probe, immunofluorescence vital stains (LIVE/DEAD[reg] EUKOLIGHT TM ) and trypan blue. The majority of these studies were performed with DU-145 human prostate cells. Data was analyzed to determine the component of cell inactivation resulting from apoptosis with the modified linear quadratic equation, -1n (SF) = (α a + α p ) D + β p D 2 , were α a represents cell inactivation by radiation-induced apoptosis, α p and β p represent cell death by proliferative mechanisms and D represents radiation dose. Results: These studies indicated that DU-145 cell death after radiation occurs over two distinct time periods. The first phase of death begins shortly after irradiation and plateaus within 16-24 hr. This process of cell death has properties consistent with apoptosis as determined by 3'-OH DNA end-labeling and nucleosome ladder assays. The second phase of cell death (determined by viability staining) begins approximately 48 hr after irradiation and continues until the remainder of inactivated cells express their death. This longer phase of cell inactivation probably represents proliferative cell death and other non-apoptotic mechanisms. The five different assays were performed on DU-145 cells 24 hr after irradiation with 10 Gy. Significant nucleosome ladders

High-throughput screening assay of hepatitis C virus helicase inhibitors using fluorescence-quenching phenomenon

International Nuclear Information System (INIS)

Tani, Hidenori; Akimitsu, Nobuyoshi; Fujita, Osamu; Matsuda, Yasuyoshi; Miyata, Ryo; Tsuneda, Satoshi; Igarashi, Masayuki; Sekiguchi, Yuji; Noda, Naohiro

2009-01-01

We have developed a novel high-throughput screening assay of hepatitis C virus (HCV) nonstructural protein 3 (NS3) helicase inhibitors using the fluorescence-quenching phenomenon via photoinduced electron transfer between fluorescent dyes and guanine bases. We prepared double-stranded DNA (dsDNA) with a 5'-fluorescent-dye (BODIPY FL)-labeled strand hybridized with a complementary strand, the 3'-end of which has guanine bases. When dsDNA is unwound by helicase, the dye emits fluorescence owing to its release from the guanine bases. Our results demonstrate that this assay is suitable for quantitative assay of HCV NS3 helicase activity and useful for high-throughput screening for inhibitors. Furthermore, we applied this assay to the screening for NS3 helicase inhibitors from cell extracts of microorganisms, and found several cell extracts containing potential inhibitors.

Concentrating and labeling genomic DNA in a nanofluidic array

DEFF Research Database (Denmark)

Marie, Rodolphe; Pedersen, Jonas Nyvold; Mir, Kalim U.

2018-01-01

, however, hinder the polymerase activity. We demonstrate a device and a protocol for the enzymatic labeling of genomic DNA arranged in a dense array of single molecules without attaching the enzyme or the DNA to a surface. DNA molecules accumulate in a dense array of pits embedded within a nanoslit due...... to entropic trapping. We then perform ϕ29 polymerase extension from single-strand nicks created on the trapped molecules to incorporate fluorescent nucleotides into the DNA. The array of entropic traps can be loaded with λ-DNA molecules to more than 90% of capacity at a flow rate of 10 pL min-1. The final...

Dehalogenation of chloroalkanes by nickel(i) porphyrin derivatives, a computational study.

Science.gov (United States)

Szatkowski, L; Hall, M B

2016-11-14

The nickel(i) octaethylisobacteriochlorin anion ([OEiBCh-Ni (I) ] - ) is commonly used as a synthetic model of cofactor F 430 from Methyl-Coenzyme M Reductase. In this regard, experimental studies show that [OEiBCh-Ni (I) ] - can catalyze dehalogenation of aliphatic halides in DMF solution by a highly efficient S N 2 reaction. To better understand this process, we constructed theoretical models of the dehalogenation of chloromethane by a simple nickel(i) isobacteriochlorin anion and compared its reactivity with that of similar Ni (I) complexes with other porphyrin-derived ligands: porphyrin, chlorin, bactreriochlorin, hexahydroporphyrin and octahydroporphyrin. Our calculations predict that all of the porphyrin derivative's model reactions proceed through low-spin complexes. Relative to the energy of the separate reactants the theoretical activation energies (free-energy barriers with solvation corrections) for the dehalogenation of chloromethane are similar for all of the porphyrin derivatives and range for the different functionals from 10-15 kcal mol -1 for B3LYP to 5-10 kcal mol -1 for M06-L and to 13-18 kcal mol -1 for ωB97X-D. The relative free energies of the products of the dehalogenation step, L-Ni-Me adducts, have a range from -5 to -40 kcal mol -1 for all functionals; generally becoming more negative with increasing saturation of the porphyrin ligand. Moreover, no significant differences in the theoretical chlorine kinetic isotope effect were discernable with change of porphyrin ligand.

Prenatal ionizing radiation-induced apoptosis of the developing murine brain with special references to the expression of some proteins

Energy Technology Data Exchange (ETDEWEB)

Kitamura, Makiko; Itoh, Kyoko; Matsumoto, Akira; Hayashi, Yoshitake; Sasaki, Ryohei; Imai, Yukihiro; Itoh, Hiroshi [Kobe Univ. (Japan). School of Medicine

2001-04-01

Apoptosis induced by ionizing irradiation of the developing mouse brain was investigated by using histology, analysis of DNA fragmentation on agarose gel and electron microscopy. A TUNEL-labeled index (L.I.) was calculated from the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) assay in 4 specific regions, cortical plate, intermediate zone, subependymal zone, and subependymal germinal matrix. The kinetics of apoptosis associated protein was examined by western blotting and immunofluorescence. C57BL/6J mice pregnant on embryonic day 14 (E14) were exposed to a single dose of 1.5-Gy irradiation. Irradiaited fetal brains at E15 and E17 showed extensive apoptosis with morphological characteristics. In all 4 regions, L.I. was greater in irradiated brains than in control brains at E15 and E17. Most of TUNEL-labeled cells expressed a mature neuronal marker (NeuN) and Bax protein, which is up-regulated in irradiation-induced apoptosis. Ionizing radiation moderately enhanced expression of Bax, Bcl-xL, and Cpp32 proteins. Postnatal irradiated mice showed microencephaly as compared to age-matched mice and the weight of whole body including brain decreased moderately. (author)

Prenatal ionizing radiation-induced apoptosis of the developing murine brain with special references to the expression of some proteins

International Nuclear Information System (INIS)

Kitamura, Makiko; Itoh, Kyoko; Matsumoto, Akira; Hayashi, Yoshitake; Sasaki, Ryohei; Imai, Yukihiro; Itoh, Hiroshi

2001-01-01

Apoptosis induced by ionizing irradiation of the developing mouse brain was investigated by using histology, analysis of DNA fragmentation on agarose gel and electron microscopy. A TUNEL-labeled index (L.I.) was calculated from the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) assay in 4 specific regions, cortical plate, intermediate zone, subependymal zone, and subependymal germinal matrix. The kinetics of apoptosis associated protein was examined by western blotting and immunofluorescence. C57BL/6J mice pregnant on embryonic day 14 (E14) were exposed to a single dose of 1.5-Gy irradiation. Irradiated fetal brains at E15 and E17 showed extensive apoptosis with morphological characteristics. In all 4 regions, L.I. was greater in irradiated brains than in control brains at E15 and E17. Most of TUNEL-labeled cells expressed a mature neuronal marker (NeuN) and Bax protein, which is up-regulated in irradiation-induced apoptosis. Ionizing radiation moderately enhanced expression of Bax, Bcl-xL, and Cpp32 proteins. Postnatal irradiated mice showed microencephaly as compared to age-matched mice and the weight of whole body including brain decreased moderately. (author)

Last stop on the road to repair: structure of E. coli DNA ligase bound to nicked DNA-adenylate.

Science.gov (United States)

Nandakumar, Jayakrishnan; Nair, Pravin A; Shuman, Stewart

2007-04-27

NAD(+)-dependent DNA ligases (LigA) are ubiquitous in bacteria and essential for growth. Their distinctive substrate specificity and domain organization vis-a-vis human ATP-dependent ligases make them outstanding targets for anti-infective drug discovery. We report here the 2.3 A crystal structure of Escherichia coli LigA bound to an adenylylated nick, which captures LigA in a state poised for strand closure and reveals the basis for nick recognition. LigA envelopes the DNA within a protein clamp. Large protein domain movements and remodeling of the active site orchestrate progression through the three chemical steps of the ligation reaction. The structure inspires a strategy for inhibitor design.

Rhombic-Shaped Nanostructures and Mechanical Properties of 2D DNA Origami Constructed with Different Crossover/Nick Designs.

Science.gov (United States)

Ma, Zhipeng; Huang, Yunfei; Park, Seongsu; Kawai, Kentaro; Kim, Do-Nyun; Hirai, Yoshikazu; Tsuchiya, Toshiyuki; Yamada, Hirofumi; Tabata, Osamu

2018-01-01

DNA origami methods enable the fabrication of various nanostructures and nanodevices, but their effective use depends on an understanding of their structural and mechanical properties and the effects of basic structural features. Frequency-modulation atomic force microscopy is introduced to directly characterize, in aqueous solution, the crossover regions of sets of 2D DNA origami based on different crossover/nick designs. Rhombic-shaped nanostructures formed under the influence of flexible crossovers placed between DNA helices are observed in DNA origami incorporating crossovers every 3, 4, or 6 DNA turns. The bending rigidity of crossovers is determined to be only one-third of that of the DNA helix, based on interhelical electrostatic forces reported elsewhere, and the measured pitches of the 3-turn crossover design rhombic-shaped nanostructures undergoing negligible bending. To evaluate the robustness of their structural integrity, they are intentionally and simultaneously stressed using force-controlled atomic force microscopy. DNA crossovers are verified to have a stabilizing effect on the structural robustness, while the nicks have an opposite effect. The structural and mechanical properties of DNA origami and the effects of crossovers and nicks revealed in this paper can provide information essential for the design of versatile DNA origami structures that exhibit specified and desirable properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of a 125I-labelled conjugate of pteroylglutamic acid and its use in a radio ligand assay of folate in blood

International Nuclear Information System (INIS)

Walton, L.

1981-01-01

The synthesis of a 125 I-labelled folate derivative is described for use in the radioassay of folate in serum and whole blood haemolysate. Pteroylglutamic acid (PGA) was conjugated with tyramine in dimethylformamide solution using a mixed anhydride procedure. The product was characterised by its ultra-violet absorption spectrum and its electrophoretic mobility. Iodination of this conjugate with 125 I, using Chloramine-T as oxidant, was carried out and gave high incorporation of label. The iodinated product, which was separated from other reactants by a simple and rapid Amberlite-IRA-400 resin separation technique, bound avidly to the folate-binding protein of cow's milk, enabling dose response curves to be constructed which provided a sensitive and precise assay for folate in serum and whole blood haemolysates. Comparison of the results obtained on serum and whole blood haemolysates with an established microbiological procedure gave good agreement. The radioassay described had improved precision at low folate levels where the discriminating need of the assay is greatest. (author)

Hormone assay

International Nuclear Information System (INIS)

Eisentraut, A.M.

1977-01-01

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. 125 I-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)

3-Bromopyruvate induces endoplasmic reticulum stress, overcomes autophagy and causes apoptosis in human HCC cell lines.

Science.gov (United States)

Ganapathy-Kanniappan, Shanmugasundaram; Geschwind, Jean-Francois H; Kunjithapatham, Rani; Buijs, Manon; Syed, Labiq H; Rao, Pramod P; Ota, Shinichi; Kwak, Byung Kook; Loffroy, Romaric; Vali, Mustafa

2010-03-01

Autophagy, a cellular response to stress, plays a role in resistance to chemotherapy in cancer cells. Resistance renders systemic chemotherapy generally ineffective against human hepatocellular carcinoma (HCC). Recently, we reported that the pyruvate analog 3-bromopyruvate (3-BrPA) promoted tumor cell death by targeting GAPDH. In continuance, we investigated the intracellular response of two human HCC cell lines (Hep3B and SK-Hep1) that differ in their status of key apoptotic regulators, p53 and Fas. 3-BrPA treatment induced endoplasmic reticulum (ER) stress, translation inhibition and apoptosis based on Western blot and qPCR, pulse labeling, Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and active caspase-3 in both the cell lines. However, electron microscopy revealed that 3-BrPA treated SK-Hep1 cells underwent classical apoptotic cell death while Hep3B cells initially responded with the protective autophagy that failed to prevent eventual apoptosis. 3-BrPA treatment promotes apoptosis in human HCC cell lines, irrespective of the intracellular response.

DNA fragmentation in spermatozoa

DEFF Research Database (Denmark)

Rex, A S; Aagaard, J.; Fedder, J

2017-01-01

Sperm DNA Fragmentation has been extensively studied for more than a decade. In the 1940s the uniqueness of the spermatozoa protein complex which stabilizes the DNA was discovered. In the fifties and sixties, the association between unstable chromatin structure and subfertility was investigated....... In the seventies, the impact of induced DNA damage was investigated. In the 1980s the concept of sperm DNA fragmentation as related to infertility was introduced as well as the first DNA fragmentation test: the Sperm Chromatin Structure Assay (SCSA). The terminal deoxynucleotidyl transferase nick end labelling...... (TUNEL) test followed by others was introduced in the nineties. The association between DNA fragmentation in spermatozoa and pregnancy loss has been extensively investigated spurring the need for a therapeutic tool for these patients. This gave rise to an increased interest in the aetiology of DNA damage...

An ultrafiltration assay for lysyl oxidase

International Nuclear Information System (INIS)

Shackleton, D.R.; Hulmes, D.J.

1990-01-01

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

Detection of NT-pro BNP using fluorescent protein modified by streptavidin as a label in immunochromatographic assay

Directory of Open Access Journals (Sweden)

Haixia Li

2016-12-01

Full Text Available A novel fluorescent immunochromatographic assay for the detection of NT-proBNP in human serum has been developed. Based on a sandwich-type immunoassay format, analytes in samples were captured by one monoclonal antibody labeled with fluorescent protein and “sandwiched” by another monoclonal antibody immobilized on the nitrocellulose membrane, the fluorescence and concentration of analytes were measured and then calculated by fluoroanalyzer. The fluorescent protein is a fusion protein and was prepared through the application of Streptavidin gene SA, β subunit cpcB of Phycocyanin, lyase alr0617, and phycoerythrobilin synthetase gene ho1, pebA, pebB for covalent binding. It is characterized with higher stability, good solubility in water and it is not easy to quench fluorescence. Take the advantages of fluorescent protein, the immunochromatographic assay exhibited a wide linear range for NT-proBNP from 200 pg ml−1 to 26,000 pg ml−1, with a detection limit of 47 pg ml−1 under optimal conditions. Compared with chemiluminescence immunoassay (CLIA, 131 human serum samples were analyzed and the correlation coefficient of the developed immunoassay was 0.978. These results demonstrated that fluorescent immunochromatographic assay is a more rapid, sensitive, specific method and could be developed into a platform for more biomarkers determination in clinical practice. Keywords: NT-pro BNP, Fluorescent protein, Immunochromatographic assay

Real-Time, Label-Free Detection of Biomolecular Interactions in Sandwich Assays by the Oblique-Incidence Reflectivity Difference Technique

Directory of Open Access Journals (Sweden)

Yung-Shin Sun

2014-12-01

Full Text Available One of the most important goals in proteomics is to detect the real-time kinetics of diverse biomolecular interactions. Fluorescence, which requires extrinsic tags, is a commonly and widely used method because of its high convenience and sensitivity. However, in order to maintain the conformational and functional integrality of biomolecules, label-free detection methods are highly under demand. We have developed the oblique-incidence reflectivity difference (OI-RD technique for label-free, kinetic measurements of protein-biomolecule interactions. Incorporating the total internal refection geometry into the OI-RD technique, we are able to detect as low as 0.1% of a protein monolayer, and this sensitivity is comparable with other label-free techniques such as surface plasmon resonance (SPR. The unique advantage of OI-RD over SPR is no need for dielectric layers. Moreover, using a photodiode array as the detector enables multi-channel detection and also eliminates the over-time signal drift. In this paper, we demonstrate the applicability and feasibility of the OI-RD technique by measuring the kinetics of protein-protein and protein-small molecule interactions in sandwich assays.

Labelled antibody techniques in glycoprotein estimation

International Nuclear Information System (INIS)

Hazra, D.K.; Ekins, R.P.; Edwards, R.; Williams, E.S.

1977-01-01

The problems in the radioimmunoassay of the glycoprotein hormones (pituitary LH, FSH and TSH and human chlorionic gonadotrophin HGG) are reviewed viz: limited specificity and sensitivity in the clinical context, interpretation of disparity between bioassay and radioimmunoassay, and interlaboratory variability. The advantages and limitations of the labelled antibody techniques - classical immonoradiometric methods and 2-site or 125 I-anti-IgG indirect labelling modifications are reviewed in general, and their theoretical potential in glycoprotein assays examined in the light of previous work. Preliminary experiments in the development of coated tube 2-site assay for glycoproteins using 125 I anti-IgG labelling are described, including conditions for maximizing solid phase extraction of the antigen, iodination of anti-IgG, and assay conditions such as effects of temperature of incubation with antigen 'hormonefree serum', heterologous serum and detergent washing. Experiments with extraction and antigen-specific antisera raised in the same or different species are described as exemplified by LH and TSH assay systems, the latter apparently promising greater sensitivity than radioimmunoassay. Proposed experimental and mathematical optimisation and validation of the method as an assay system is outlined, and the areas for further work delineated. (orig.) [de

Specific binding assay technique; standardization of reagent

International Nuclear Information System (INIS)

Huggins, K.G.; Roitt, I.M.

1979-01-01

The standardization of a labelled constituent, such as anti-IgE, for use in a specific binding assay method is disclosed. A labelled ligand, such as IgE, is standardized against a ligand reference substance, such as WHO standard IgE, to determine the weight of IgE protein represented by the labelled ligand. Anti-light chain antibodies are contacted with varying concentrations of the labelled ligand. The ligand is then contacted with the labelled constituent which is then quantitated in relation to the amount of ligand protein present. The preparation of 131 I-labelled IgE is described. Also disclosed is an improved specific binding assay test method for determining the potency of an allergen extract in serum from an allergic individual. The improvement involved using a parallel model system of a second complex which consisted of anti-light chain antibodies, labelled ligand and the standardized labelled constituent (anti-IgE). The amount of standardized labelled constituent bound to the ligand in the first complex was determined, as described above, and the weight of ligand inhibited by addition of soluble allergen was then used as a measure of the potency of the allergen extract. (author)

Potency values from the local lymph node assay: application to classification, labelling and risk assessment.

Science.gov (United States)

Loveless, S E; Api, A-M; Crevel, R W R; Debruyne, E; Gamer, A; Jowsey, I R; Kern, P; Kimber, I; Lea, L; Lloyd, P; Mehmood, Z; Steiling, W; Veenstra, G; Woolhiser, M; Hennes, C

2010-02-01

Hundreds of chemicals are contact allergens but there remains a need to identify and characterise accurately skin sensitising hazards. The purpose of this review was fourfold. First, when using the local lymph node assay (LLNA), consider whether an exposure concentration (EC3 value) lower than 100% can be defined and used as a threshold criterion for classification and labelling. Second, is there any reason to revise the recommendation of a previous ECETOC Task Force regarding specific EC3 values used for sub-categorisation of substances based upon potency? Third, what recommendations can be made regarding classification and labelling of preparations under GHS? Finally, consider how to integrate LLNA data into risk assessment and provide a rationale for using concentration responses and corresponding no-effect concentrations. Although skin sensitising chemicals having high EC3 values may represent only relatively low risks to humans, it is not possible currently to define an EC3 value below 100% that would serve as an appropriate threshold for classification and labelling. The conclusion drawn from reviewing the use of distinct categories for characterising contact allergens was that the most appropriate, science-based classification of contact allergens according to potency is one in which four sub-categories are identified: 'extreme', 'strong', 'moderate' and 'weak'. Since draining lymph node cell proliferation is related causally and quantitatively to potency, LLNA EC3 values are recommended for determination of a no expected sensitisation induction level that represents the first step in quantitative risk assessment. 2009 Elsevier Inc. All rights reserved.

Siim Nestor soovitab : Jus Fine ja DJ Hype. Mutant ja Nick Luscombe. Kuurorti kogumik / Siim Nestor

Index Scriptorium Estoniae

Nestor, Siim, 1974-

2005-01-01

Inglise drum'n'bass-staar DJ Hype 17. märtsil klubis Privé üritusel "Jus' Fine". Inglise diskor Nick Luscombe üritusel "Mutant" 18. märtsil klubis Privé. Plaadifirma Kuurortrecords esitleb 18. märtsil oma uut kogumikplaati Pirita jõe suudmes asuval laeval Monica

Dual isotope assays

International Nuclear Information System (INIS)

Smith, G.F.W.; Stevens, R.A.J.; Jacoby, B.

1980-01-01

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)

Determination and analysis of site-specific 125I decay-induced DNA double-strand break end-group structures.

Science.gov (United States)

Datta, Kamal; Weinfeld, Michael; Neumann, Ronald D; Winters, Thomas A

2007-02-01

End groups contribute to the structural complexity of radiation-induced DNA double-strand breaks (DSBs). As such, end-group structures may affect a cell's ability to repair DSBs. The 3'-end groups of strand breaks caused by gamma radiation, or oxidative processes, under oxygenated aqueous conditions have been shown to be distributed primarily between 3'-phosphoglycolate and 3'-phosphate, with 5'-phosphate ends in both cases. In this study, end groups of the high-LET-like DSBs caused by 125I decay were investigated. Site-specific DNA double-strand breaks were produced in plasmid pTC27 in the presence or absence of 2 M DMSO by 125I-labeled triplex-forming oligonucleotide targeting. End-group structure was assessed enzymatically as a function of the DSB end to serve as a substrate for ligation and various forms of end labeling. Using this approach, we have demonstrated 3'-hydroxyl (3'-OH) and 3'-phosphate (3'-P) end groups and 5'-ends (> or = 42%) terminated by phosphate. A 32P postlabeling assay failed to detect 3'-phosphoglycolate in a restriction fragment terminated by the 125I-induced DNA double-strand break, and this is likely due to restricted oxygen diffusion during irradiation as a frozen aqueous solution. Even so, end-group structure and relative distribution varied as a function of the free radical scavenging capacity of the irradiation buffer.

Fluorescent-labeled ligands for the benzodiazepine receptor - Part 1 : Synthesis and characterization of fluorescent-labeled benzodiazepines

NARCIS (Netherlands)

Janssen, M.J; Hulst, A.J R L; Kellogg, R.M; Hendriks, M.M W B; Ensing, K; de Zeeuw, R.A

Because radioactive labeled ligands in receptor assays have several disadvantages, we synthesized a number of fluorescent-labeled benzodiazepines. Several fluorophores were attached at different positions of 1,4-benzodiazepine molecules in order to assess the impact of the fluorophores and their

Linerless label device and method

KAUST Repository

Binladen, Abdulkari

2016-01-14

This apparatus and method for applying a linerless label to an end user product includes a device with a printer for printing on a face surface of a linerless label, and a release coat applicator for applying a release coat to the face surface of the label; another device including an unwinder unit (103) to unwind a roll of printed linerless label; a belt (108); a glue applicator (102) for applying glue to the belt; a nip roller (106) for contacting and applying pressure to the face surface of the linerless label such that the glue on the belt transfers to the back surface of the linerless label; at least one slitting knife 105) positioned downstream the belt and a rewinder unit (104) positioned downstream the slitting knife; and a third device which die cuts and applies the linerless label to an end user object.

Reductive methods for isotopic labeling of antibiotics

International Nuclear Information System (INIS)

Champney, W.S.

1989-01-01

Methods for the reductive methylation of the amino groups of eight different antibiotics using 3 HCOH or H 14 COH are presented. The reductive labeling of an additional seven antibiotics by NaB 3 H 4 is also described. The specific activity of the methyl-labeled drugs was determined by a phosphocellulose paper binding assay. Two quantitative assays for these compounds based on the reactivity of the antibiotic amino groups with fluorescamine and of the aldehyde and ketone groups with 2,4-dinitrophenylhydrazine are also presented. Data on the cellular uptake and ribosome binding of these labeled compounds are also presented

HoloMonitor M4: holographic imaging cytometer for real-time kinetic label-free live-cell analysis of adherent cells

Science.gov (United States)

Sebesta, Mikael; Egelberg, Peter J.; Langberg, Anders; Lindskov, Jens-Henrik; Alm, Kersti; Janicke, Birgit

2016-03-01

Live-cell imaging enables studying dynamic cellular processes that cannot be visualized in fixed-cell assays. An increasing number of scientists in academia and the pharmaceutical industry are choosing live-cell analysis over or in addition to traditional fixed-cell assays. We have developed a time-lapse label-free imaging cytometer HoloMonitorM4. HoloMonitor M4 assists researchers to overcome inherent disadvantages of fluorescent analysis, specifically effects of chemical labels or genetic modifications which can alter cellular behavior. Additionally, label-free analysis is simple and eliminates the costs associated with staining procedures. The underlying technology principle is based on digital off-axis holography. While multiple alternatives exist for this type of analysis, we prioritized our developments to achieve the following: a) All-inclusive system - hardware and sophisticated cytometric analysis software; b) Ease of use enabling utilization of instrumentation by expert- and entrylevel researchers alike; c) Validated quantitative assay end-points tracked over time such as optical path length shift, optical volume and multiple derived imaging parameters; d) Reliable digital autofocus; e) Robust long-term operation in the incubator environment; f) High throughput and walk-away capability; and finally g) Data management suitable for single- and multi-user networks. We provide examples of HoloMonitor applications of label-free cell viability measurements and monitoring of cell cycle phase distribution.

Calibration and validation of the 14C-labelled polyethylene glycol-binding assay for tannins in tropical browse

International Nuclear Information System (INIS)

Mlambo, V.; Makkar, H.P.S.

2005-01-01

This study evaluates the radiolabelled polyethylene glycol (PEG)-binding procedure [Silanikove, N., Shinder, D., Gilboa, N., Eyal, M., Nitsan, Z., 1996. Polyethylene glycol-binding to plant samples as an assay for the biological effects of tannins: predicting the negative effects of tannins in Mediterranean browse on rumen degradation. J. Agric. Food Chem. 44, 3230-3234] for tannin analysis, using 27 tropical browse plants. In this method, the amount of PEG bound to a plant sample is assumed to be a reflection of its tannin content. The method was modified to exclude the use of non-tanniniferous substrate for estimating non-specific binding (NSB) in tannin-containing substrates. Non-specific binding values varied widely (0.4-2.8 mg PEG/100 mg DM tannin-free substrate) when the tannin-free substrate was changed from wheat straw to either rye grass or maize shoots. We therefore propose a modified radiolabelled PEG-binding method to estimate the level of PEG-binding (PEGb) to tannin-containing foliage without using tannin-free substrate to correct for non-specific binding. In this approach, incremental levels of each tanniniferous substrate were used to generate PEGb values. The resultant linear response was analysed and tannin activity was expressed as the slope of the response curve (PEGbSlope) observed for each substrate. The slope takes into account the non-specific binding in each substrate, thus PEGbSlope does not require correction for NSB using tannin-free samples. This approach improved the correlation between PEGb and the 125 I-labelled bovine serum albumin precipitation assay. Relationships between the modified PEG-binding assay and radiolabelled bovine serum albumin assay, in vitro tannin bioassay and colorimetric assays are presented. (author)

New sensitive and specific assay for human immunodeficiency virus antibodies using labeled recombinant fusion protein and time-resolved fluoroimmunoassay.

OpenAIRE

Siitari, H; Turunen, P; Schrimsher, J; Nunn, M

1990-01-01

A new, rapid method for the detection of human immunodeficiency virus type 1 (HIV-1) antibody by time-resolved fluoroimmunoassay (TR-FIA) was developed. In this assay format, microtitration strips were coated with a recombinant fusion protein, and the same protein was labeled with europium and added into the wells simultaneously with the test specimens. The recombinant fusion protein contained the HIV-1 p24 gag protein sequence that carried an insertion, near the carboxyl terminus, of a 23-am...

Shrink-induced graphene sensor for alpha-fetoprotein detection with low-cost self-assembly and label-free assay

Science.gov (United States)

Sando, Shota; Zhang, Bo; Cui, Tianhong

2017-12-01

Combination of shrink induced nano-composites technique and layer-by-layer (LbL) self-assembled graphene challenges controlling surface morphology. Adjusting shrink temperature achieves tunability on graphene surface morphology on shape memory polymers, and it promises to be an alternative in fields of high-surface-area conductors and molecular detection. In this study, self-assembled graphene on a shrink polymer substrate exhibits nanowrinkles after heating. Induced nanowrinkles on graphene with different shrink temperature shows distinct surface roughness and wettability. As a result, it becomes more hydrophilic with higher shrink temperatures. The tunable wettability promises to be utilized in, for example, microfluidic devices. The graphene on shrink polymer also exhibits capability of being used in sensing applications for pH and alpha-fetoprotein (AFP) detection with advantages of label free and low cost, due to self-assembly technique, easy functionalization, and antigen-antibody reaction on graphene surface. The detection limit of AFP detection is down to 1 pg/mL, and therefore the sensor also has a significant potential for biosensing as it relies on low-cost self-assembly and label-free assay.

Off-label use of rituximab in autoimmune disease in the Top End of the Northern Territory, 2008-2016.

Science.gov (United States)

Wongseelashote, Sarah; Tayal, Vipin; Bourke, Peter Francis

2018-02-01

Rituximab, an anti-CD20 B-cell depleting monoclonal antibody, is increasingly prescribed off-label for a range of autoimmune diseases. There has not previously been an audit of off-label rituximab use in the Northern Territory, where the majority of patients are Aboriginal. To evaluate retrospectively off-label rituximab use in autoimmune diseases in the Top End of the Northern Territory. We performed a retrospective audit of 8 years of off-label rituximab use at the Royal Darwin Hospital, the sole tertiary referral centre for the Darwin, Katherine and East Arnhem regions. Electronic and paper records were reviewed for demographic information, diagnosis/indication for rituximab, doses, previous/concomitant immunosuppression, clinical outcomes and specific adverse events. Rituximab was prescribed off-label to 66 patients for 24 autoimmune diseases. The majority of patients (62.1%) were Aboriginal and 60.6% female. The most common indications were refractory/relapsing disease despite standard therapies (68.7%) or severe disease with rituximab incorporated into an induction immunosuppressive regimen (19.4%). Systemic lupus erythematosus was the underlying diagnosis in 28.8% of cases. A clinically significant response was demonstrated in 74.2% of cases overall. There were 18 clinically significant infections; however, 13 were in patients receiving concurrent immunosuppressive therapy. There was a total of nine deaths from any cause. Rituximab has been used off-label for a range of autoimmune diseases in this population with a high proportion of Aboriginal patients successfully and safely in the majority of cases. © 2017 Royal Australasian College of Physicians.

Dual Labeling Biotin Switch Assay to Reduce Bias Derived From Different Cysteine Subpopulations: A Method to Maximize S-Nitrosylation Detection.

Science.gov (United States)

Chung, Heaseung Sophia; Murray, Christopher I; Venkatraman, Vidya; Crowgey, Erin L; Rainer, Peter P; Cole, Robert N; Bomgarden, Ryan D; Rogers, John C; Balkan, Wayne; Hare, Joshua M; Kass, David A; Van Eyk, Jennifer E

2015-10-23

S-nitrosylation (SNO), an oxidative post-translational modification of cysteine residues, responds to changes in the cardiac redox-environment. Classic biotin-switch assay and its derivatives are the most common methods used for detecting SNO. In this approach, the labile SNO group is selectively replaced with a single stable tag. To date, a variety of thiol-reactive tags have been introduced. However, these methods have not produced a consistent data set, which suggests an incomplete capture by a single tag and potentially the presence of different cysteine subpopulations. To investigate potential labeling bias in the existing methods with a single tag to detect SNO, explore if there are distinct cysteine subpopulations, and then, develop a strategy to maximize the coverage of SNO proteome. We obtained SNO-modified cysteine data sets for wild-type and S-nitrosoglutathione reductase knockout mouse hearts (S-nitrosoglutathione reductase is a negative regulator of S-nitrosoglutathione production) and nitric oxide-induced human embryonic kidney cell using 2 labeling reagents: the cysteine-reactive pyridyldithiol and iodoacetyl based tandem mass tags. Comparison revealed that <30% of the SNO-modified residues were detected by both tags, whereas the remaining SNO sites were only labeled by 1 reagent. Characterization of the 2 distinct subpopulations of SNO residues indicated that pyridyldithiol reagent preferentially labels cysteine residues that are more basic and hydrophobic. On the basis of this observation, we proposed a parallel dual-labeling strategy followed by an optimized proteomics workflow. This enabled the profiling of 493 SNO sites in S-nitrosoglutathione reductase knockout hearts. Using a protocol comprising 2 tags for dual-labeling maximizes overall detection of SNO by reducing the previously unrecognized labeling bias derived from different cysteine subpopulations. © 2015 American Heart Association, Inc.

Label-free detection of endocrine disrupting chemicals by integrating a competitive binding assay with a piezoelectric ceramic resonator.

Science.gov (United States)

Hu, Liang-sheng; Fong, Chi-Chun; Zou, Lan; Wong, Wing-Leung; Wong, Kwok-Yin; Wu, Rudolf S S; Yang, Mengsu

2014-03-15

A piezoelectric biosensor for detection of endocrine disrupting chemicals (EDCs) was developed by incorporating chemical/biochemical recognition elements on the ceramic resonator surface for competitive binding assays. A facile electrodeposition was employed to modify the sensor surface with Au nanoparticles, which increased the surface area and enhanced the binding capacity of the immobilized probes. Thiol-labeled long chain hydrocarbon with bisphenol A (BPA) as head group was synthesized and self-assembled on the Au nanoparticle surface as the sensing probes, which showed a linear response upon the binding of estrogen receptor (ER-α) ranging from 1 to 30 nM. Detection of estrone, 17β-estradiol and BPA was achieved by integrating a competitive binding assay with the piezoelectric sensor. In this detection scheme, different concentrations of EDCs were incubated with 30 nM of ER-α, and the un-bounded ER-α in the solution was captured by the probes immobilized on the ceramic resonator, which resulted in the frequency changes for different EDCs. The biosensor assay exhibited a linear response to EDCs with a low detection limit of 2.4-2.9 nM (S/N=3), and required only a small volume of sample (1.5 µl) with the assay time of 2h. The performance of the biosensor assay was also evaluated for rapid and facile determination of EDCs of environmental relevant concentrations in drinking water and seawater, and the recovery rate was in the range between 94.7% and 109.8%. © 2013 Elsevier B.V. All rights reserved.

Label-free fluorescence strategy for sensitive microRNA detection based on isothermal exponential amplification and graphene oxide.

Science.gov (United States)

Li, Wei; Hou, Ting; Wu, Min; Li, Feng

2016-01-01

MicroRNAs (miRNAs) play an important role in many biological processes, and have been regarded as potential targets and biomarkers in cancer diagnosis and therapy. Also, to meet the big challenge imposed by the characteristics of miRNAs, such as small size and vulnerability to enzymatic digestion, it is of great importance to develop accurate, sensitive and simple miRNA assays. Herein, we developed a label-free fluorescence strategy for sensitive miRNA detection by combining isothermal exponential amplification and the unique features of SYBR Green I (SG) and graphene oxide (GO), in which SG gives significantly enhanced fluorescence upon intercalation into double-stranded DNAs (dsDNAs), and GO selectively adsorbs miRNA, single-stranded DNA and SG, to protect miRNA from enzymatic digestion, and to quench the fluorescence of the adsorbed SG. In the presence of the target miRNA, the ingeniously designed hairpin probe (HP) is unfolded and the subsequent polymerization and strand displacement reaction takes place to initiate the target recycling process. The newly formed dsDNAs are then recognized and cleaved by the nicking enzyme, generating new DNA triggers with the same sequence as the target miRNA, which hybridize with intact HPs to initiate new extension reactions. As a result, the circular exponential amplification for target miRNA is achieved and large amount of dsDNAs are formed to generate significantly enhanced fluorescence upon the intercalation of SG. Thus sensitive and selective fluorescence miRNA detection is realized, and the detection limit of 3 fM is obtained. Besides, this method exhibits additional advantages of simplicity and low cost, since expensive and tedious labeling process is avoided. Therefore, the as-proposed label-free fluorescence strategy has great potential in the applications in miRNA-related clinical practices and biochemical researches. Copyright © 2015 Elsevier B.V. All rights reserved.

New high-performance liquid chromatography assay for glycosyltransferases based on derivatization with anthranilic acid and fluorescence detection.

Science.gov (United States)

Anumula, Kalyan Rao

2012-07-01

Assays were developed using the unique labeling chemistry of 2-aminobenzoic acid (2AA; anthranilic acid, AA) for measuring activities of both β1-4 galactosyltransferase (GalT-1) and α2-6 sialyltransferase (ST-6) by high-performance liquid chromatography (HPLC) with fluorescence detection (Anumula KR. 2006. Advances in fluorescence derivatization methods for high-performance liquid chromatographic analysis of glycoprotein carbohydrates. Anal Biochem. 350:1-23). N-Acetylglucosamine (GlcNAc) and N-acetyllactosamine were used as acceptors and uridine diphosphate (UDP)-galactose and cytidine monophosphate (CMP)-N-acetylneuraminic acid (NANA) as donors for GalT-1 and ST-6, respectively. Enzymatic products were labeled in situ with AA and were separated from the substrates on TSKgel Amide 80 column using normal-phase conditions. Enzyme units were determined from the peak areas by comparison with the concomitantly derivatized standards Gal-β1-4GlcNAc and NANA-α2-6 Gal-β1-4GlcNAc. Linearity (time and enzyme concentration), precision (intra- and interassay) and reproducibility for the assays were established. The assays were found to be useful in monitoring the enzyme activities during isolation and purification. The assays were highly sensitive and performed equal to or better than the traditional radioactive sugar-based measurements. The assay format can also be used for measuring the activity of other transferases, provided that the carbohydrate acceptors contain a reducing end for labeling. An assay for glycoprotein acceptors was developed using IgG. A short HPLC profiling method was developed for the separation of IgG glycans (biantennary G0, G1, G2, mono- and disialylated), which facilitated the determination of GalT-1 and ST-6 activities in a rapid manner. Furthermore, this profiling method should prove useful for monitoring the changes in IgG glycans in clinical settings.

123I labelled vasoactive intestinal peptide: Optimization of the radioiodination method, in vivo and in vitro assays

International Nuclear Information System (INIS)

Pozzi, O.R.; Sajaroff, E.O.; Edreira, M.; Gomez, S.I.; Manzini, A.

2002-01-01

In the framework of the CRP, our country has worked on the optimization of synthesis, quality control, in vitro and in vivo evaluation of 123 I radiopharmaceuticals based on peptides. We have worked on selective labelling procedures using prosthetic groups with the goal to create a strong carbon-halogen bond, which will be resistant to in vivo dehalogenation and other catabolic processes. The method utilizes the labelling agent, reactive with ε-amino lysine groups, N-succinimidyl 3-iodobenzoate. This conjugation agent was radiolabelled by using an organometallic intermediate to facilitate the reaction. The organometallic N-succinimidyl 3-(tri-nbutylstannyl) benzoate (ATE) was made in a three-step synthesis pathway. The yields for the reactions of this synthetic pathway were: 56.4% for the first reaction, 67% for the second, and 58% for the ATE (469 mg, 0.92 mmol). Because of only 0.1 μmol of ATE is needed for the labelling of peptides, from one batch of organic synthesis we obtained ATE to make more than 9000 labelling. The N-succinimidyl 3-(tri-n-butylstannyl) benzoate (ATE) was radiolabelled in 55-85% radiochemical yield to obtain the N-succinimidyl 3-iodobenzoate ( [ 131 I]SIB ). Parameters like reactive concentration and isolation method of the labelling agent were studied. The labelling agent [ 131 I]SIB was subsequently conjugated to a human IgG and a peptide. A chemotactic peptide was used as a model peptide. A potent chemotactic peptide N-formyl-norleucyl-leucyl-phenylalanyl-norleucyltyrosyl- lysine (fNleLFNleYK) was derivatized by reaction with the labelling agent in 59-75% of radiochemical yield. This derivatized peptide bound specifically to human polymorphonuclear leukocytes in vitro and exhibited biological activity in a superoxide production assay. Binding affinity IC 50 : 36 nM, in the displacing of [ 3 H]fMLF binding, and IC 50 : 68 nM, in the displacing of the fNleLFNleYK-[ 131 I]SIB conjugate, for the derivatized peptide were obtained. Because

Assay of oestrogen

International Nuclear Information System (INIS)

Edwards, J.C.

1981-01-01

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 125 I-labelled oestriol during the assay procedure and the steroid-protein bound 125 I-labelled oestriol is precipitated along with the antibody-bound 125 I-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.)

Calibration and validation of the {sup 14}C-labelled polyethylene glycol-binding assay for tannins in tropical browse

Energy Technology Data Exchange (ETDEWEB)

Mlambo, V. [Animal Production Unit, FAO/IAEA Agriculture and Biotechnology Laboratory, Seibersdorf (Austria)]. E-mail: vmlambo@agric.uniswa.sz; Makkar, H.P.S. [Animal Production and Health Section, Joint FAO/IAEA Division of Nuclear Techniques in Agriculture and Food, International Atomic Energy Agency, Vienna (Austria)

2005-08-19

This study evaluates the radiolabelled polyethylene glycol (PEG)-binding procedure [Silanikove, N., Shinder, D., Gilboa, N., Eyal, M., Nitsan, Z., 1996. Polyethylene glycol-binding to plant samples as an assay for the biological effects of tannins: predicting the negative effects of tannins in Mediterranean browse on rumen degradation. J. Agric. Food Chem. 44, 3230-3234] for tannin analysis, using 27 tropical browse plants. In this method, the amount of PEG bound to a plant sample is assumed to be a reflection of its tannin content. The method was modified to exclude the use of non-tanniniferous substrate for estimating non-specific binding (NSB) in tannin-containing substrates. Non-specific binding values varied widely (0.4-2.8 mg PEG/100 mg DM tannin-free substrate) when the tannin-free substrate was changed from wheat straw to either rye grass or maize shoots. We therefore propose a modified radiolabelled PEG-binding method to estimate the level of PEG-binding (PEGb) to tannin-containing foliage without using tannin-free substrate to correct for non-specific binding. In this approach, incremental levels of each tanniniferous substrate were used to generate PEGb values. The resultant linear response was analysed and tannin activity was expressed as the slope of the response curve (PEGbSlope) observed for each substrate. The slope takes into account the non-specific binding in each substrate, thus PEGbSlope does not require correction for NSB using tannin-free samples. This approach improved the correlation between PEGb and the {sup 125}I-labelled bovine serum albumin precipitation assay. Relationships between the modified PEG-binding assay and radiolabelled bovine serum albumin assay, in vitro tannin bioassay and colorimetric assays are presented. (author)

Cytotoxicity and mitogenicity assays with real-time and label-free monitoring of human granulosa cells with an impedance-based signal processing technology intergrating micro-electronics and cell biology.

Science.gov (United States)

Oktem, Ozgur; Bildik, Gamze; Senbabaoglu, Filiz; Lack, Nathan A; Akin, Nazli; Yakar, Feridun; Urman, Defne; Guzel, Yilmaz; Balaban, Basak; Iwase, Akira; Urman, Bulent

2016-04-01

A recently developed technology (xCelligence) integrating micro-electronics and cell biology allows real-time, uninterrupted and quantitative analysis of cell proliferation, viability and cytotoxicity by measuring the electrical impedance of the cell population in the wells without using any labeling agent. In this study we investigated if this system is a suitable model to analyze the effects of mitogenic (FSH) and cytotoxic (chemotherapy) agents with different toxicity profiles on human granulosa cells in comparison to conventional methods of assessing cell viability, DNA damage, apoptosis and steroidogenesis. The system generated the real-time growth curves of the cells, and determined their doubling times, mean cell indices and generated dose-response curves after exposure to cytotoxic and mitogenic stimuli. It accurately predicted the gonadotoxicity of the drugs and distinguished less toxic agents (5-FU and paclitaxel) from more toxic ones (cisplatin and cyclophosphamide). This platform can be a useful tool for specific end-point assays in reproductive toxicology. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of laser-induced fluorescence detection to assay DNA damage

International Nuclear Information System (INIS)

Sharma, M.; Freund, H.G.

1991-01-01

A precolumn derivation method has been developed for high performance liquid chromatographic (HPLC) analysis of DNA damage using fluorescence detection. The modified nucleotide, having excised enzymatically from the exposed DNA, is enriched from the normal nucleotides and labeled with a fluorescent reagent. The labeling procedure involves phosphoramidation of the nucleotide with ethylenediamine (EDA) followed by conjugation of the free amino end of the phosphoramidate with 5-dimethylaminonaphthalene 1-sulfonyl chloride, commonly known as Dansyl chloride. The dansylated nucleotide can be analyzed with a sub-picomole limit of detection (LOD) by conventional HPLC using a conventional fluorescence detector. By combining microbore HPLC with laser-induced fluorescence (LIF) detection, the authors present the development of an analytical system that has sub-femtomole LOD for real-time analysis of the dansylated nucleotide. In this paper the application of the developed system in fluorescence postlabeling assay of a small alkyl-modified nucleotide (5-methyl CMP) in calf-thymus DNA is discussed

Chlorella vulgaris triggers apoptosis in hepatocarcinogenesis-induced rats*

Science.gov (United States)

Mohd Azamai, Emey Suhana; Sulaiman, Suhaniza; Mohd Habib, Shafina Hanim; Looi, Mee Lee; Das, Srijit; Abdul Hamid, Nor Aini; Wan Ngah, Wan Zurinah; Mohd Yusof, Yasmin Anum

2009-01-01

Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200~250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatoctyes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats. PMID:19198018

A Mitochondria-Dependent Pathway Mediates the Apoptosis of GSE-Induced Yeast

OpenAIRE

Cao, Sishuo; Xu, Wentao; Zhang, Nan; Wang, Yan; Luo, YunBo; He, Xiaoyun; Huang, Kunlun

2012-01-01

Grapefruit seed extract (GSE), which has powerful anti-fungal activity, can induce apoptosis in S. cerevisiae. The yeast cells underwent apoptosis as determined by testing for apoptotic markers of DNA cleavage and typical chromatin condensation by Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL) and 4,6'-diaminidino-2-phenylindole (DAPI) staining and electron microscopy. The changes of ΔΨmt (mitochondrial transmembrane potential) and ROS (reactive oxygen species) ...

Label-Enhanced Surface Plasmon Resonance: A New Concept for Improved Performance in Optical Biosensor Analysis

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Niko Granqvist

2013-11-01

Full Text Available Surface plasmon resonance (SPR is a well-established optical biosensor technology with many proven applications in the study of molecular interactions as well as in surface and material science. SPR is usually applied in the label-free mode which may be advantageous in cases where the presence of a label may potentially interfere with the studied interactions per se. However, the fundamental challenges of label-free SPR in terms of limited sensitivity and specificity are well known. Here we present a new concept called label-enhanced SPR, which is based on utilizing strongly absorbing dye molecules in combination with the evaluation of the full shape of the SPR curve, whereby the sensitivity as well as the specificity of SPR is significantly improved. The performance of the new label-enhanced SPR method was demonstrated by two simple model assays: a small molecule assay and a DNA hybridization assay. The small molecule assay was used to demonstrate the sensitivity enhancement of the method, and how competitive assays can be used for relative affinity determination. The DNA assay was used to demonstrate the selectivity of the assay, and the capabilities in eliminating noise from bulk liquid composition variations.

Label-Enhanced Surface Plasmon Resonance: A New Concept for Improved Performance in Optical Biosensor Analysis

Science.gov (United States)

Granqvist, Niko; Hanning, Anders; Eng, Lars; Tuppurainen, Jussi; Viitala, Tapani

2013-01-01

Surface plasmon resonance (SPR) is a well-established optical biosensor technology with many proven applications in the study of molecular interactions as well as in surface and material science. SPR is usually applied in the label-free mode which may be advantageous in cases where the presence of a label may potentially interfere with the studied interactions per se. However, the fundamental challenges of label-free SPR in terms of limited sensitivity and specificity are well known. Here we present a new concept called label-enhanced SPR, which is based on utilizing strongly absorbing dye molecules in combination with the evaluation of the full shape of the SPR curve, whereby the sensitivity as well as the specificity of SPR is significantly improved. The performance of the new label-enhanced SPR method was demonstrated by two simple model assays: a small molecule assay and a DNA hybridization assay. The small molecule assay was used to demonstrate the sensitivity enhancement of the method, and how competitive assays can be used for relative affinity determination. The DNA assay was used to demonstrate the selectivity of the assay, and the capabilities in eliminating noise from bulk liquid composition variations. PMID:24217357

Potential protection of green tea polyphenols against 1800 MHz electromagnetic radiation-induced injury on rat cortical neurons.

Science.gov (United States)

Liu, Mei-Li; Wen, Jian-Qiang; Fan, Yu-Bo

2011-10-01

Radiofrequency electromagnetic fields (EMF) are harmful to public health, but the certain anti-irradiation mechanism is not clear yet. The present study was performed to investigate the possible protective effects of green tea polyphenols against electromagnetic radiation-induced injury in the cultured rat cortical neurons. In this study, green tea polyphenols were used in the cultured cortical neurons exposed to 1800 MHz EMFs by the mobile phone. We found that the mobile phone irradiation for 24 h induced marked neuronal cell death in the MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide) and TUNEL (TdT mediated biotin-dUTP nicked-end labeling) assay, and protective effects of green tea polyphenols on the injured cortical neurons were demonstrated by testing the content of Bcl-2 Assaciated X protein (Bax) in the immunoprecipitation assay and Western blot assay. In our study results, the mobile phone irradiation-induced increases in the content of active Bax were inhibited significantly by green tea polyphenols, while the contents of total Bax had no marked changes after the treatment of green tea polyphenols. Our results suggested a neuroprotective effect of green tea polyphenols against the mobile phone irradiation-induced injury on the cultured rat cortical neurons.

Anticancer Activity of Indian Stingless Bee Propolis: An In Vitro Study

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Milind K. Choudhari

2013-01-01

Full Text Available Indian stingless bee propolis has a complex chemical nature and is reported to possess various medicinal properties. In the present study, anticancer activity of the ethanolic extract of propolis (EEP was explored by testing the cytotoxic and apoptotic effect in four different cancer cell lines, namely, MCF-7 (human breast cancer, HT-29 (human colon adenocarcinoma, Caco-2 (human epithelial colorectal adenocarcinoma, and B16F1 (murine melanoma, at different concentrations. Cytotoxicity was evaluated by MTT assay and Trypan blue dye exclusion assay. EEP at a concentration of 250 g/mL exhibited ≥50% mortality in all cell lines tested (i.e., IC50 value. EEP revealed a concentration and time dependent cytotoxic effect. Apoptosis was estimated by differential staining (ethidium bromide/acridine orange and TUNEL (deoxynucleotidyl transferase-dUTP nick end labeling assay. Light microscopy and atomic force microscopy demonstrated morphological features of apoptosis in all the cell lines after treatment with 250 g/mL EEP for 24 h. Thus, early onset of apoptosis is the reason for anticancer activity of Indian stingless bee propolis. Further, the antioxidant potential of Indian stingless bee propolis was demonstrated to substantiate its anticancer activity.

Aptamer based fluorescent cocaine assay based on the use of graphene oxide and exonuclease III-assisted signal amplification

International Nuclear Information System (INIS)

Zhang, Yulin; Zhang, Guo-Jun; Sun, Zhongyue; Tang, Lina; Zhang, Hong

2016-01-01

The article reports an aptamer based assay for cocaine by employing graphene oxide and exonuclease III-assisted signal amplification. It is based on the following scheme and experimental steps: (1) Exo III can digest dsDNA with blunt or recessed 3-terminus, but it has limited activity to ssDNA or dsDNA with protruding 3-terminus; (2) GO can absorb the FAM-labeled ssDNA probe and quench the fluorescence of probe, while the affinity between FAM-labeled mononucleotide and GO is negligible; (3) Cocaine aptamer can be split into two flexible ssDNA pieces (Probe 1 and Probe 2) without significant perturbation of cocaine-binding abilities; (4) The triple complex consisting of Probe 1, Probe 2 and cocaine can be digested by Exo III with the similar efficiency as normal dsDNA. Cocaine aptamer is split into two flexible ssDNA pieces (Probe 2 and 3′-FAM-labeled Probe 1). Cocaine can mediate the cocaine aptamer fragments forming a triplex. The triple complex has unique characteristic with 3′-FAM-labeled blunt end at the Probe 1 and 3′-overhang end at Probe 2. If exonuclease III is added, it will catalyze the stepwise removal of fluorescein (FAM) labeled mononucleotides from the 3-hydroxy termini of the special triplex complex, resulting in liberation of cocaine. The cocaine released in this step can produce a new cleavage cycle, thereby leading to target recycling. Through such a cyclic bound-hydrolysis process, small amounts of cocaine can induce the cleavage of a large number of FAM-labeled probe 1. The cleaved FAM-labeled mononucleotides are not adsorbed on the surface of graphene oxide (GO), so a strong fluorescence signal enhancement is observed as the cocaine triggers enzymatic digestion. Under optimized conditions, the assay allows cocaine to be detected in the 1 to 500 nM concentration range with a detection limit of 0.1 nM. The method was applied to the determination of cocaine in spiked human plasma, with recoveries ranging from 92.0 to 111.8 % and RSD of <12

Development of versatile universal reagent immunoradiometric assay technique

International Nuclear Information System (INIS)

Hazra, D.K.

1982-10-01

Immunoradiometric assays, which make use of labelled antibodies, potentially offer better sensitivity and specificity than do radioimmunoassays, which use labelled antigens. In addition, they can in principle be performed in a particularly convenient scheme wherein the same labelled reagent may be used for many different analytes - thus serving as a ''universal'' labelled reagent. Thus if the specific antibody for every analyte is raised in rabbits, and an anti-rabbit antibody is labelled, the latter may be added after the specific antibody to quantify the amount of specific antibody bound to analyte and thereby the amount of analyte present. The potential greater sensitivity and specificity of the immunoradiometric procedure, coupled with the potential convenience of the ''universal'' labelled reagent, might allow such immunoradiometric techniques to be used effectively in the study of communicable diseases in developing countries. Development of these procedures was the subject of this investigation. Many components of these procedures had to be explored and provisionally optimized, including coating of assay tubes with ''extraction'' antibody, immunological purification of antibodies, labelling of antibodies, and intermediate steps toward these goals. Applications were thereupon tested using those provisionally optimized components. The ''universal'' labelled reagent, a donkey anti-rabbit antiserum, was successfully used in the assay of TSH; however, cross reactions of the reagent with non-rabbit immunoglobulins and other materials present seriously limited the sensitivity of the method. Using conventional immunoradiometric procedures, circulating TB and amoebic antibodies could be detected in patients suffering from these diseases. Similarly, circulating antigens in the same patients could also be detected, but not with sufficient sensitivity and specificity to provide a reliable analytical system. Numerous improvements will be required before these techniques

Spectrophotometric Enzyme Assays for High-Throughput Screening

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Jean-Louis Reymond

2004-01-01

Full Text Available This paper reviews high-throughput screening enzyme assays developed in our laboratory over the last ten years. These enzyme assays were initially developed for the purpose of discovering catalytic antibodies by screening cell culture supernatants, but have proved generally useful for testing enzyme activities. Examples include TLC-based screening using acridone-labeled substrates, fluorogenic assays based on the β-elimination of umbelliferone or nitrophenol, and indirect assays such as the back-titration method with adrenaline and the copper-calcein fluorescence assay for aminoacids.

Rapid screening assay for calcium bioavailability studies

International Nuclear Information System (INIS)

Luhrsen, K.R.; Hudepohl, G.R.; Smith, K.T.

1986-01-01

Calcium bioavailability has been studied by numerous techniques. The authors report here the use of the gamma emitting isotope of calcium ( 47 Ca) in a whole body retention assay system. In this system, calcium sources are administered by oral gavage and subsequent counts are determined and corrected for isotopic decay. Unlike iron and zinc retention curves, which exhibit a 2-3 day equilibration period, calcium reaches equilibration after 24 hours. Autoradiographic analysis of the femurs indicate that the newly absorbed calcium is rapidly distributed to the skeletal system. Moreover, the isotope is distributed along the entire bone. Comparisons of calcium bioavailability were made using intrinsic/extrinsic labeled milk from two species i.e. rat and goat as well as CaCO 3 . In addition, extrinsic labeled cow milk was examined. In the rat, the extrinsic labeled calcium from milk was better absorbed than the intrinsic calcium. This was not the case in goat milk or the calcium carbonate which exhibited no significant differences. Chromatographic analysis of the labeled milk indicates a difference in distribution of the 47 Ca. From these data, the authors recommend the use of this assay system in calcium bioavailability studies. The labeling studies and comparisons indicate caution should be used, however, in labeling techniques and species milk comparison

Using label-free screening technology to improve efficiency in drug discovery.

Science.gov (United States)

Halai, Reena; Cooper, Matthew A

2012-02-01

Screening assays have traditionally utilized reporter labels to quantify biological responses relevant to the disease state of interest. However, there are limitations associated with the use of labels that may be overcome with temporal measurements possible with label-free. This review comprises general and system-specific information from literature searches using PubMed, published books and the authors' personal experience. This review highlights the label-free approaches in the context of various applications. The authors also note technical issues relevant to the development of label-free assays and their application to HTS. The limitations associated with the use of transfected cell lines and the use of label-based assays are gradually being realized. As such, greater emphasis is being placed on label-free biophysical techniques using native cell lines. The introduction of 96- and 384-well plate label-free systems is helping to broker a wider acceptance of these approaches in high-throughput screening. However, potential users of the technologies remain skeptical, primarily because the physical basis of the signals generated, and their contextual relevance to cell biology and signal transduction, has not been fully elucidated. Until this is done, these new technology platforms are more likely to complement, rather than replace, traditional screening platforms.

Label-free and sensitive detection of T4 polynucleotide kinase activity via coupling DNA strand displacement reaction with enzymatic-aided amplification.

Science.gov (United States)

Cheng, Rui; Tao, Mangjuan; Shi, Zhilu; Zhang, Xiafei; Jin, Yan; Li, Baoxin

2015-11-15

Several fluorescence signal amplification strategies have been developed for sensitive detection of T4 polynucleotide kinase (T4 PNK) activity, but they need fluorescence dye labeled DNA probe. We have addressed the limitation and report here a label-free strategy for sensitive detection of PNK activity by coupling DNA strand displacement reaction with enzymatic-aided amplification. A hairpin oligonucleotide (hpDNA) with blunt ends was used as the substrate for T4 PNK phosphorylation. In the presence of T4 PNK, the stem of hpDNA was phosphorylated and further degraded by lambda exonuclease (λ exo) from 5' to 3' direction to release a single-stranded DNA as a trigger of DNA strand displacement reaction (SDR). The trigger DNA can continuously displace DNA P2 from P1/P2 hybrid with the help of specific cleavage of nicking endonuclease (Nt.BbvCI). Then, DNA P2 can form G-quadruplex in the presence of potassium ions and quadruplex-selective fluorphore, N-methyl mesoporphyrin IX (NMM), resulting in a significant increase in fluorescence intensity of NMM. Thus, the accumulative release of DNA P2 led to fluorescence signal amplification for determining T4 PNK activity with a detection limit of 6.6×10(-4) U/mL, which is superior or comparative with established approaches. By ingeniously utilizing T4 PNK-triggered DNA SDR, T4 PNK activity can be specifically and facilely studied in homogeneous solution containing complex matrix without any external fluorescence labeling. Moreover, the influence of different inhibitors on the T4 PNK activity revealed that it also can be explored to screen T4 PNK inhibitors. Therefore, this label-free amplification strategy presents a facile and cost-effective approach for nucleic acid phosphorylation related research. Copyright © 2015 Elsevier B.V. All rights reserved.

Preparation of a homogeneous extract of human growth hormone, isohormone B, and its 125I-labelling for utilization in radioligand assays

International Nuclear Information System (INIS)

Santos, A.J. dos.

1985-01-01

Non-destructive polyacrylamide gel electrophoretic (PAGE) tecnique, with direct UV-densitometry, was set up to permit both qualitative and quantitative studies of human growth hormone (hGH) isohormone purification is presented. This tecnique was used on a preparative scale to obtain milligram amounts of the fundamental form of hGH, isohormone B(Ih-B). Reversed electrophoresis was employed to elute the protein band form the gel. Retention of bio-and immunoactivity was demonstrated via two separate experiments. An 'in vivo' bioassay, based on the weight increase of hypophysectomized rats with a 2 x 2 factorial assay design, was used to compare the true somatotrophic activity of an hGH preparation submitted to the purification process with that of a single control preparation. Retention of immunoactivity was confirmed by studying the antibody binding properties of purified and radioiodinated Ih-B and by determination of its absolute immunopotency against a calibrated secondary standard. Radioimmuno assay curves, determined using Ih-B, as a standard and labelled preparation, showed its applicability in setting up assays based on more homogeneous reagents. (Author) [pt

Activation of calcium-sensing receptor accelerates apoptosis in hyperplastic parathyroid cells

International Nuclear Information System (INIS)

Mizobuchi, Masahide; Ogata, Hiroaki; Hatamura, Ikuji; Saji, Fumie; Koiwa, Fumihiko; Kinugasa, Eriko; Koshikawa, Shozo; Akizawa, Tadao

2007-01-01

Calcimimetic compounds inhibit not only parathyroid hormone (PTH) synthesis and secretion, but also parathyroid cell proliferation. The aim of this investigation is to examine the effect of the calcimimetic compound NPS R-568 (R-568) on parathyroid cell death in uremic rats. Hyperplastic parathyroid glands were obtained from uremic rats (subtotal nephrectomy and high-phosphorus diet), and incubated in the media only or the media which contained high concentration of R-568 (10 -4 M), or 10% cyclodextrin, for 6 h. R-568 treatment significantly suppressed medium PTH concentration compared with that of the other two groups. R-568 treatment not only increased the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay-positive cells, but also induced the morphologic changes of cell death determined by light or electron microscopy. These results suggest that CaR activation by R-568 accelerates parathyroid cell death, probably through an apoptotic mechanism in uremic rats in vitro

Selection of well labelled insulin fractions for radioimmunoassay use

Energy Technology Data Exchange (ETDEWEB)

Awh, O D; Kim, J R [Korea Atomic Energy Research Inst., Seoul (Republic of Korea)

1980-06-01

Selection methods of well labelled insulin fractions based on two different criteria were compared to establish an efficient low level RIA of insulin and to elucidate the correlation between the immunoreactivity and the charcoal-adsorptivity of the radioiodine labelled insulin. The result indicated that the selection of well labelled insulin fractions by means of a charcoal-adsorption test is inappropriate. Generally, the distribution of radioactivity, antibody-bindability, and charcoal-adsorptivity of the labelled insulin was not consistent with each other. Thus, the selection should be carried out for every labelling batch to get the utmost assay reliability by antibody-bindability but not by charcoal-adsorptivity. By using the well selected labelled insulin fractions based on antibody-binding, a correct assay for a reference serum was possible, and by extending the incubation time up to 96 hrs, a sharp dose response curve could be obtained even in the range of below 5 ..mu..U/ml standard insulin doses.

The DNA Repair Repertoire of Mycobacterium smegmatis FenA Includes the Incision of DNA 5' Flaps and the Removal of 5' Adenylylated Products of Aborted Nick Ligation.

Science.gov (United States)

Uson, Maria Loressa; Ghosh, Shreya; Shuman, Stewart

2017-09-01

We characterize Mycobacterium smegmatis FenA as a manganese-dependent 5'-flap endonuclease homologous to the 5'-exonuclease of DNA polymerase I. FenA incises a nicked 5' flap between the first and second nucleotides of the duplex segment to yield a 1-nucleotide gapped DNA, which is then further resected in dinucleotide steps. Initial FenA cleavage at a Y-flap or nick occurs between the first and second nucleotides of the duplex. However, when the template 3' single strand is eliminated to create a 5'-tailed duplex, FenA incision shifts to between the second and third nucleotides. A double-flap substrate with a mobile junction (mimicking limited strand displacement synthesis during gap repair) is preferentially incised as the 1-nucleotide 3'-flap isomer, with the scissile phosphodiester shifted by one nucleotide versus a static double flap. FenA efficiently removes the 5' App(dN) terminus of an aborted nick ligation reaction intermediate, thereby highlighting FenA as an agent of repair of such lesions, which are formed under a variety of circumstances by bacterial NAD + -dependent DNA ligases and especially by mycobacterial DNA ligases D and C. IMPORTANCE Structure-specific DNA endonucleases are implicated in bacterial DNA replication, repair, and recombination, yet there is scant knowledge of the roster and catalytic repertoire of such nucleases in Mycobacteria This study identifies M. smegmatis FenA as a stand-alone endonuclease homologous to the 5'-exonuclease domain of mycobacterial DNA polymerase 1. FenA incises 5' flaps, 5' nicks, and 5' App(dN) intermediates of aborted nick ligation. The isolated N-terminal domain of M. smegmatis Pol1 is also shown to be a flap endonuclease. Copyright © 2017 American Society for Microbiology.

A high ratio of apoptosis to proliferation correlates with improved survival after radiotherapy for cervical adenocarcinoma

International Nuclear Information System (INIS)

Sheridan, Mary T.; Cooper, Rachel A.; West, Catharine M.L.

1999-01-01

Purpose: A retrospective study was made of the role of apoptosis in determining radiotherapy outcome in 39 adenocarcinoma of the cervix. A comparison was also made of the detection of apoptosis by morphology and the TdT dUtp nick end-labeling (TUNEL) assay. Methods and Materials: The level of apoptosis was assessed in paraffin-embedded sections by cell morphology, the TUNEL assay, and a combination of the two. A total of 2,000 cells were counted per section, to obtain apoptotic (AI) and mitotic (MI) indices. Results: Patients with a high AI had a higher survival rate than those with a low AI, however, the difference was not significant. Using a ratio of apoptosis to proliferation indices, patients with an AI:MI > median had significantly better survival than those with AI:MI < median. This was true where the AI was quantified by morphology alone (p = 0.030) or in combination with the TUNEL assay (p = 0.008). Where the AI was quantified by a combination of morphology and TUNEL, the 5-year survival rates for women with AI:MI greater or less than the median were 81% and 25%, respectively. Conclusion: A high ratio of AI:MI in adenocarcinoma of the cervix indicates a good prognosis. A combination of the TUNEL assay and morphology provided the best discrimination between outcome groups

Acetylsalicylic acid and labeling of blood constituents with technetium-99m

Energy Technology Data Exchange (ETDEWEB)

Fonseca, Adenilson de Souza da [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Dept. de Farmacologia e Psicobiologia; Frydman, Jacques Natan Grinapel; Rocha, Vanessa Camara da; Bernardo-Filho, Mario [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Dept. de Biofisica e Biometria

2005-10-15

Acetylsalicylic acid is the drug most used an anti-inflammatory agent and for secondary prevention of thrombotic phenomenon. Drugs can modify the labeling of blood constituents with technetium-99m (99m Tc). The aim of this work was to evaluate the effect of in vitro or in vivo assays with acetylsalicylic acid on the labeling of the blood constituents with 99m Tc. In vitro assay was performed with samples of whole blood from Wistar rats incubated with acetylsalicylic acid (1.0 mg/ml) for one hour before the 99m Tc-labeling process. For in vivo assay, Wistar rats were treated with acetylsalicylic acid (1.5 mg/kg) during one hour, and the whole blood was withdrawn for the 99m Tc-labeling process. Saline was used in control groups. Data showed that the fixation of 99m Tc to the blood constituents was not significantly (p>0.05) modified in in vitro and in vivo assays with acetylsalicylic acid, at least not when the experiments were carried out with the doses normally used in human beings. (author)

False positive reaction due to endogenous biotin activity in glandular epithelium of decidua Reação falso positiva em epitélio glandular da decídua devido a atividade endógena de biotina

Directory of Open Access Journals (Sweden)

Liliana Cruz Spano

2005-06-01

Full Text Available Biotin-labeled probe was used in an in situ hybridisation assay to localize virus infection in formalin-fixed, paraffin embedded tissues taken from eleven abortion cases. Probes for human cytomegalovirus (HCMV, human Parvovirus B19 (B19 and human adenovirus type 2 (HAd2, were labeled with biotin-11-dUTP by nick-translation reaction. Streptavidin-alkaline-phosphatase (SAP was used to detect biotin, followed by 4-nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP solution. Positive reaction was observed in nucleus of glandular ephitelium cells of decidua either in positive or in negative control at first and second gestational trimester. The reaction was not inhibited with blocking solution for alkaline phosphatase endogenous activity and it persisted even with probes omission. The use of adequate negative control permitted to reveal the presence of nuclear biotin in glandular epithelium of decidua, responsible for false positivity in detection systems involving streptavidin biotin system (StrepABC. The stained cells resembled to cytophatic effect due to herpesvirus, which could induce further misinterpretation. The results obtained in this study strongly recommend that DNA detection by in situ hybridisation reaction in gestational endometrium should be done without using StrepABC system.Sondas marcadas com biotina foram utilizadas neste trabalho para detecção de infecção viral por hibridização in situ em tecidos fixados com formalina e embebidos em parafina de 11 casos obtidos de abortamento. Sondas para citomegalovírus humano (HCMV, parvovírus B19 humano (B19 e adenovírus humano tipo 2 (HAd2, foram marcadas com biotina-11-dUTP através da reação de nick-translation. Estreptavidina conjugada com fosfatase alcalina (SAP seguida por solução de 4-nitro-azul de tetrazolio/5-bromo-4-cloro-3-indolil fosfato (NBT/BCIP foram utilizadas para detecção da biotina após a reação de hibridização. Reação positiva foi

A cascade autocatalytic strand displacement amplification and hybridization chain reaction event for label-free and ultrasensitive electrochemical nucleic acid biosensing.

Science.gov (United States)

Chen, Zhiqiang; Liu, Ying; Xin, Chen; Zhao, Jikuan; Liu, Shufeng

2018-04-23

Herein, an autocatalytic strand displacement amplification (ASDA) strategy was proposed for the first time, which was further ingeniously coupled with hybridization chain reaction (HCR) event for the isothermal, label-free and multiple amplification toward nucleic acid detection. During the ASDA module, the target recognition opens the immobilized hairpin probe (IP) and initiates the annealing of the auxiliary DNA strand (AS) with the opened IP for the successive polymerization and nicking reaction in the presence of DNA polymerase and nicking endonuclease. This induces the target recycling and generation of a large amount of intermediate DNA sequences, which can be used as target analogy to execute the autocatalytic strand displacement amplification. Simultaneously, the introduced AS strand can propagate the HCR between two hairpins (H1 and H2) to form a linear DNA concatamer with cytosine (C)-rich loop region, which can facilitate the in-situ synthesis of silver nanoclusters (AgNCs) as electrochemical tags for further amplification toward target responses. With current cascade ASDA and HCR strategy, the detection of target DNA could be achieved with a low detection limit of about 0.16 fM and a good selectivity. The developed biosensor also exhibits the distinct advantages of flexibility and simplicity in probe design and biosensor fabrication, and label-free electrochemical detection, thus opens a promising avenue for the detection of nucleic acid with low abundance in bioanalysis and clinical biomedicine. Copyright © 2018 Elsevier B.V. All rights reserved.

Direct Competitive Enzyme-Linked Immunosorbent Assay (ELISA).

Science.gov (United States)

Kohl, Thomas O; Ascoli, Carl A

2017-07-05

The competitive enzyme-linked immunosorbent assay (ELISA) (cELISA; also called an inhibition ELISA) is designed so that purified antigen competes with antigen in the test sample for binding to an antibody that has been immobilized in microtiter plate wells. The same concept works if the immobilized molecule is antigen and the competing molecules are purified labeled antibody versus antibody in a test sample. Direct cELISAs incorporate labeled antigen or antibody, whereas indirect assay configurations use reporter-labeled secondary antibodies. The cELISA is very useful for determining the concentration of small-molecule antigens in complex sample mixtures. In the direct cELISA, antigen-specific capture antibody is adsorbed onto the microtiter plate before incubation with either known standards or unknown test samples. Enzyme-linked antigen (i.e., labeled antigen) is also added, which can bind to the capture antibody only when the antibody's binding site is not occupied by either the antigen standard or antigen in the test samples. Unbound labeled and unlabeled antigens are washed away and substrate is added. The amount of antigen in the standard or the test sample determines the amount of reporter-labeled antigen bound to antibody, yielding a signal that is inversely proportional to antigen concentration within the sample. Thus, the higher the antigen concentration in the test sample, the less labeled antigen is bound to the capture antibody, and hence the weaker is the resultant signal. © 2017 Cold Spring Harbor Laboratory Press.

Synthesis and detection of 3'-OH terminal biotin-labeled DNA probes

International Nuclear Information System (INIS)

Brakel, C.L.; Engelhardt, D.L.

1985-01-01

Nick translation has been used to prepare biotin-dUTP-containing DNA probes. These stable DNA probes have been identified, following hybridization to target DNA, by fluorescence using antibiotin antibodies or by enzyme reactions in which the enzyme has been linked to avidin or streptavidin. It is probable that this technology will be applicable to certain diagnostic determinations and that, with sufficient sensitivity, this technology might provide a system for obtaining rapid and specific diagnoses in situations presently requiring time-consuming growth assays. The sensitivity of this assay can be increased in two ways: (1) by increasing the amount of biotin contained in the DNA probes, and (2) by increasing the response to individual biotin molecules in the DNA probes. This report demonstrates that terminal deoxynucleotide transferase can be employed to increase the biotin content of DNA probes. We also introduce a new streptavidin-linked enzyme system that produces a greater response to biotinylated DNA probes than does streptavidin-linked horseradish peroxidase

101 labeled brain images and a consistent human cortical labeling protocol

Directory of Open Access Journals (Sweden)

Arno eKlein

2012-12-01

Full Text Available We introduce the Mindboggle-101 dataset, the largest and most complete set of free, publicly accessible, manually labeled human brain images. To manually label the macroscopic anatomy in magnetic resonance images of 101 healthy participants, we created a new cortical labeling protocol that relies on robust anatomical landmarks and minimal manual edits after initialization with automated labels. The Desikan-Killiany-Tourville (DKT protocol is intended to improve the ease, consistency, and accuracy of labeling human cortical areas. Given how difficult it is to label brains, the Mindboggle-101 dataset is intended to serve as brain atlases for use in labeling other brains, as a normative dataset to establish morphometric variation in a healthy population for comparison against clinical populations, and contribute to the development, training, testing, and evaluation of automated registration and labeling algorithms. To this end, we also introduce benchmarks for the evaluation of such algorithms by comparing our manual labels with labels automatically generated by probabilistic and multi-atlas registration-based approaches. All data and related software and updated information are available on the http://www.mindboggle.info/data/ website.

101 Labeled Brain Images and a Consistent Human Cortical Labeling Protocol

Science.gov (United States)

Klein, Arno; Tourville, Jason

2012-01-01

We introduce the Mindboggle-101 dataset, the largest and most complete set of free, publicly accessible, manually labeled human brain images. To manually label the macroscopic anatomy in magnetic resonance images of 101 healthy participants, we created a new cortical labeling protocol that relies on robust anatomical landmarks and minimal manual edits after initialization with automated labels. The “Desikan–Killiany–Tourville” (DKT) protocol is intended to improve the ease, consistency, and accuracy of labeling human cortical areas. Given how difficult it is to label brains, the Mindboggle-101 dataset is intended to serve as brain atlases for use in labeling other brains, as a normative dataset to establish morphometric variation in a healthy population for comparison against clinical populations, and contribute to the development, training, testing, and evaluation of automated registration and labeling algorithms. To this end, we also introduce benchmarks for the evaluation of such algorithms by comparing our manual labels with labels automatically generated by probabilistic and multi-atlas registration-based approaches. All data and related software and updated information are available on the http://mindboggle.info/data website. PMID:23227001

Suitability of a liquid chromatography assay of neomycin sulfate to replace the microbiological assay for neomycin in USP Monographs.

Science.gov (United States)

Hanko, Valoran P; Rohrer, Jeffrey S

2010-01-05

The current USP National Formulary contains 65 Monographs for drug formulations containing neomycin. All 65 Monographs prescribe a bioassay for neomycin assay. This bioassay, based on cell culture, is labor intensive, has poor precision, and cannot be adapted for purity or identification. High-performance anion-exchange chromatography with integrated pulsed amperometric detection (HPAE-IPAD), a liquid chromatography technique, has been shown to be suitable for neomycin purity analysis and neomycin assay of an over-the-counter first aid cream (Hanko and Rohrer [17]). Here we propose that an HPAE-IPAD assay can replace the bioassay in the 65 neomycin-containing Monographs. We applied the HPAE-IPAD assay to four neomycin-containing drug products representing the four classes of formulations found in the 65 Monographs, liquid, solid, suspension, and cream. Each drug was analyzed with two chromatography systems, and on 3 separate days. For all products, HPAE-IPAD measurements were precise and accurate with respect to the label concentrations. There was also high accuracy for spike recovery of neomycin from the four drug products throughout 70-150% of the labeled concentration. These results suggest that an HPAE-IPAD assay would be an accurate assay for neomycin, and would be faster and more precise than the current bioassay.

Imaging of Enzymes in the Steroid Biosynthetic Pathway: Synthesis of 18F-Labelled Tracers

International Nuclear Information System (INIS)

Erlandsson, Maria

2009-01-01

This thesis deals with the synthesis and development of 18 F-labelled alkyl etomidate and vorozole analogues, and their use as positron emission tomography (PET) tracers for the imaging of the steroid enzymes 11β-hydroxylase and aromatase. Two synthetic 18 F-labelling approaches to the etomidate and vorozole analogues were developed, and the analogues were evaluated in some biological assays. The two-step labelling method was used to synthesise many compounds for biological evaluation. In the first step, a 18 F-labelled intermediate based on a ditosylate or a halogenated diethyl ether was synthesised and used directly in the next alkylation step. The decay-corrected (d.c.) radiochemical yield was higher compared to other known two-step labelling methods. Once an appropriate candidate has been chosen for clinical evaluation, a one-step labelling method will be more suitable. We therefore developed a method based on precursors that had leaving groups at the end of their alkyl chains, and used these directly in the 18 F-labelling synthesis. The one-step 18 F-labelling synthesis required less reaction time and produced higher specific radioactivity and d.c. radiochemical yield than our two-step synthesis. With microwave heating, the reaction time was reduced to seconds and the d.c. radiochemical yield was better than that obtained with conventional heating. The one-step synthesis simplified the technical handling by allowing the tracer syntheses to be automated on the TRACERLab FX FN

Evaluation of human sperm chromatin status after selection using a modified Diff-Quik stain indicates embryo quality and pregnancy outcomes following in vitro fertilization.

Science.gov (United States)

Tavares, R S; Silva, A F; Lourenço, B; Almeida-Santos, T; Sousa, A P; Ramalho-Santos, J

2013-11-01

Sperm chromatin/DNA damage can be measured by a variety of assays. However, it has been reported that these tests may lose prognostic value in Assisted Reproductive Technology (ART) cycles when assessed in post-prepared samples, possibly due to the normalizing effect promoted by sperm preparation procedures. We have recently implemented a modified version of the Diff-Quik staining assay that allows for the evaluation of human sperm chromatin status in native samples, together with standard sperm morphology assessment. However, the value of this parameter in terms of predicting in vitro fertilization (IVF) and Intracytoplasmic sperm injection (ICSI) outcomes after sperm selection is unknown. In this study, data from 138 couples undergoing in vitro fertilization (IVF) or Intracytoplasmic sperm injection (ICSI) treatments showed that sperm chromatin integrity was significantly improved after density gradient centrifugation and swim up (p embryo development rates (p > 0.05). However, sperm samples presenting lower percentages of damaged chromatin were associated with better quality (Grade I) embryos in both ART procedures (p selection may occur; but not in ICSI, where sperm selection is operator dependent. This quick and low-cost assay is suggested as an alternative method to detect sperm chromatin status in minimal clinical settings, when no other well-established and robust assays (e.g. Sperm chromatin structure assay, terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling) are available. © 2013 American Society of Andrology and European Academy of Andrology.

The Anticancer Effects of Radachlorin-mediated Photodynamic Therapy in the Human Endometrial Adenocarcinoma Cell Line HEC-1-A.

Science.gov (United States)

Kim, Su-Mi; Rhee, Yun-Hee; Kim, Jong-Soo

2017-11-01

We investigated the effect of photodynamic therapy (PDT) using radachlorin on invasion, vascular formation and apoptosis by targeting epidermal growth factor receptor (EGFR)/vascular endothelial growth factor receptor 2 (VEGFR2) signaling pathways in the HEC-1-A endometrial adenocarcinoma cell line. To investigate the apoptotic pathway, we performed the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay, and western blot analysis. We also evaluated the effects of PDT on tubular capillary formation in and invasion by HEC-1-A cells with a tube formation assay, invasion assay, prostaglandin E2 (PGE2) assay, and western blot analysis. PDT had anticancer effects on HEC-1-A through activation of the intrinsic pathway of apoptosis via caspase-9 and poly-(ADP-ribose) polymerase (PARP). PDT also inhibited tubular capillary formation in and invasion by HEC-1-A under VEGF pretreatment, that resulted from down-regulation of VEGFR2, EGFR, Ras homolog gene family/ member A (RhoA) and PGE2. These results are indicative of the specificity of radachlorin-mediated PDT to VEGF. The major advantage of radachlorin-mediated PDT is its selectivity for cancer tissue while maintaining adjacent normal endometrial tissue. Therefore, radachlorin-mediated PDT might offer high anticancer efficacy for endometrial adenocarcinoma and an especially useful modality for preserving fertility. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Linerless label device and method

KAUST Repository

Binladen, Abdulkari

2016-01-01

This apparatus and method for applying a linerless label to an end user product includes a device with a printer for printing on a face surface of a linerless label, and a release coat applicator for applying a release coat to the face surface

Methods and devices for protein assays

Science.gov (United States)

Chhabra, Swapnil [San Jose, CA; Cintron, Jose M [Indianapolis, IN; Shediac, Renee [Oakland, CA

2009-11-03

Methods and devices for protein assays based on Edman degradation in microfluidic channels are disclosed herein. As disclosed, the cleaved amino acid residues may be immobilized in an array format and identified by detectable labels, such as antibodies, which specifically bind given amino acid residues. Alternatively, the antibodies are immobilized in an array format and the cleaved amino acids are labeled identified by being bound by the antibodies in the array.

Isothermal amplification detection of nucleic acids by a double-nicked beacon.

Science.gov (United States)

Shi, Chao; Zhou, Meiling; Pan, Mei; Zhong, Guilin; Ma, Cuiping

2016-03-01

Isothermal and rapid amplification detection of nucleic acids is an important technology in environmental monitoring, foodborne pathogen detection, and point-of-care clinical diagnostics. Here we have developed a novel method of isothermal signal amplification for single-stranded DNA (ssDNA) detection. The ssDNA target could be used as an initiator, coupled with a double-nicked molecular beacon, to originate amplification cycles, achieving cascade signal amplification. In addition, the method showed good specificity and strong anti-jamming capability. Overall, it is a one-pot and isothermal strand displacement amplification method without the requirement of a stepwise procedure, which greatly simplifies the experimental procedure and decreases the probability of contamination of samples. With its advantages, the method would be very useful to detect nucleic acids in point-of-care or field use. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of fasting and refeeding on intestinal cell proliferation and apoptosis in hammerhead shark (Sphyrna lewini

Directory of Open Access Journals (Sweden)

Hideya Takahashi

2014-04-01

Full Text Available Objective: To examine the effects of fasting and refeeding on intestinal cell proliferation and apoptosis in an opportunistic predator, hammerhead shark (Sphyrna lewini of elasmobranch fishes which are among the earliest known extant groups of vertebrates to have the valvular intestine typical for the primitive species. Methods: Animals were euthanized after 5-10 d of fasting or feeding, or after 10-day fasting and 5-day refeeding. Intestinal apoptosis and cell proliferation were assessed by using oligonucleotide detection assay, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and immunohistochemistry of proliferating cells nuclear antigen. Results: Plasma levels of cholesterol and glucose were reduced by fasting. Intestinal apoptosis generally decreased during fasting. Numerous apoptotic cells were observed around the tips of the villi, primarily in the epithelium in the fed sharks, whereas fewer labeled nuclei were detected in the epithelium of fasted sharks. Refeeding returned intestinal apoptosis to the level in the fed sharks. Proliferating cells were observed in the epithelium around the troughs of the villi and greater in number in fed sharks, whereas fewer labeled nuclei were detected in fasted sharks. Conclusions: The cell turnover is modified in both intestinal epithelia of the shark and the murines by fasting/feeding, but in opposite directions. The difference may reflect the feeding ecology of the elasmobranchs, primitive intermittent feeders.

Positron emission tomography imaging of cardiomyocyte apoptosis with a novel molecule probe [18F]FP-DPAZn2

Science.gov (United States)

Sun, Ting; Tang, Ganghua; Tian, Hua; Hu, Kongzhen; Yao, Shaobo; Su, Yifan; Wang, Changqian

2015-01-01

Cardiomyocyte apoptosis plays a causal role in the development and progression of heart failure. Currently, there is no effective imaging agent that can be used to detect cardiomyocyte apoptosis in vivo. To target phosphatidylserine (PS) on the surface of the dying cell, we synthesized a novel 18F-labeled Zn2+-dipicolylamine (DPA) analog, [18F]FP-DPAZn2, and evaluated it for noninvasive imaging of cardiomyocyte apoptosis. In vitro, the fluorescence imaging of dansyl-DPAZn2 was suitable for detecting cardiomyocyte apoptosis, which was confirmed by confocal immunofluorescence imaging, terminal dUTP nick-end labeling (TUNEL) assay, and western blot assay. The in vivo biodistribution showed that the uptake ratios of [18F]FP-DPAZn2 in the heart were 4.41±0.29% ID/g at 5 min, 2.40 ± 0.43% ID/g at 30 min, 1.63 ± 0.26% ID/g at 60 min, and 1.43% ± 0.07 ID/g at 120 min post-injection. In vivo, the [18F]FP-DPAZn2 PET images showed more cardiac accumulation of radioactivity 60 min post-injection in acute myocardial infarction (AMI) rats than in normal rats, which was consistent with the findings of a histological analysis of the rat cardiac tissues in vitro. [18F]FP-DPAZn2 PET imaging has the capability for myocardial apoptosis detection, but the method will require improved myocardial uptake for the noninvasive evaluation of cardiomyocyte apoptosis in clinical settings. PMID:26416423

Assay of old-world screw-worm fly, Chrysomya bezziana, labelled with 32P

International Nuclear Information System (INIS)

Lamb, K.P.; Sands, D.P.A.; Spradbery, J.P.

1978-01-01

Techniques for 32 P labelling of larvae and adults of the screw-worm fly, Chrysomya bezziana, are described. Egg masses of labelled flies were readily identified. At the doses used for field releases, oviposition activity, fertility and longevity of female flies were not adversely affected. Radioactive egg masses were recovered from sentinel animals following field release of labelled flies. (Auth.)

Beyond labels: A review of the application of quantum dots as integrated components of assays, bioprobes, and biosensors utilizing optical transduction

Energy Technology Data Exchange (ETDEWEB)

Algar, W. Russ; Tavares, Anthony J. [Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6 (Canada); Krull, Ulrich J., E-mail: ulrich.krull@utoronto.ca [Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6 (Canada)

2010-07-12

A comprehensive review of the development of assays, bioprobes, and biosensors using quantum dots (QDs) as integrated components is presented. In contrast to a QD that is selectively introduced as a label, an integrated QD is one that is present in a system throughout a bioanalysis, and simultaneously has a role in transduction and as a scaffold for biorecognition. Through a diverse array of coatings and bioconjugation strategies, it is possible to use QDs as a scaffold for biorecognition events. The modulation of QD luminescence provides the opportunity for the transduction of these events via fluorescence resonance energy transfer (FRET), bioluminescence resonance energy transfer (BRET), charge transfer quenching, and electrochemiluminescence (ECL). An overview of the basic concepts and principles underlying the use of QDs with each of these transduction methods is provided, along with many examples of their application in biological sensing. The latter include: the detection of small molecules using enzyme-linked methods, or using aptamers as affinity probes; the detection of proteins via immunoassays or aptamers; nucleic acid hybridization assays; and assays for protease or nuclease activity. Strategies for multiplexed detection are highlighted among these examples. Although the majority of developments to date have been in vitro, QD-based methods for ex vivo biological sensing are emerging. Some special attention is given to the development of solid-phase assays, which offer certain advantages over their solution-phase counterparts.

Gamma-irradiation of homodeoxyoligonucleotides 32P-labelled at one end: computer simulation of the chain length distribution of the radioactive fragments

International Nuclear Information System (INIS)

Teoule, R.; Duplaa, A.M.

1987-01-01

Electrophoresis on polyacrylamide gels of the fragments resulting from γ-irradiation of single-stranded oligodeoxyribonucleotides labelled at their 5'- or 3'-end proved a potent tool for analysis of the radiation-induced chain breakage of DNA. Owing to the fact that the oligonucleotide may be ruptured at more than one site, counting of the electrophoresis bands must be corrected and it is necessary to assess the influence of the cleavage position on the band intensities. A complicating factor is the inhomogeneity of the system due to the presence of the four bases A, T, C and G. To circumvent this problem, the homooligodeoxyribonucleotides (dA) 15 , (dC) 15 , (dT) 15 were used as experimental probes. They were γ-irradiated in solution, heated in alkali and resulting fragments separated by gel electrophoresis. A computer simulation of band intensities was compiled based on the general assumption that the chain breakage is homogeneous. Experimental results obtained from the homooligodeoxyribonucleotides labelled at either the 5' or the 3'-end are in excellent agreement with theoretical calculations. Abacus giving the gel band intensities (percentage) against the nucleotide positions and the remaining intensity of the original oligonucleotide have been obtained. (author)

Assays for calcitonin receptors

International Nuclear Information System (INIS)

Teitelbaum, A.P.; Nissenson, R.A.; Arnaud, C.D.

1985-01-01

The assays for calcitonin receptors described focus on their use in the study of the well-established target organs for calcitonin, bone and kidney. The radioligand used in virtually all calcitonin binding studies is 125 I-labelled salmon calcitonin. The lack of methionine residues in this peptide permits the use of chloramine-T for the iodination reaction. Binding assays are described for intact bone, skeletal plasma membranes, renal plasma membranes, and primary kidney cell cultures of rats. Studies on calcitonin metabolism in laboratory animals and regulation of calcitonin receptors are reviewed

Metal-amplified Density Assays, (MADAs), including a Density-Linked Immunosorbent Assay (DeLISA).

Science.gov (United States)

Subramaniam, Anand Bala; Gonidec, Mathieu; Shapiro, Nathan D; Kresse, Kayleigh M; Whitesides, George M

2015-02-21

This paper reports the development of Metal-amplified Density Assays, or MADAs - a method of conducting quantitative or multiplexed assays, including immunoassays, by using Magnetic Levitation (MagLev) to measure metal-amplified changes in the density of beads labeled with biomolecules. The binding of target analytes (i.e. proteins, antibodies, antigens) to complementary ligands immobilized on the surface of the beads, followed by a chemical amplification of the binding in a form that results in a change in the density of the beads (achieved by using gold nanoparticle-labeled biomolecules, and electroless deposition of gold or silver), translates analyte binding events into changes in density measureable using MagLev. A minimal model based on diffusion-limited growth of hemispherical nuclei on a surface reproduces the dynamics of the assay. A MADA - when performed with antigens and antibodies - is called a Density-Linked Immunosorbent Assay, or DeLISA. Two immunoassays provided a proof of principle: a competitive quantification of the concentration of neomycin in whole milk, and a multiplexed detection of antibodies against Hepatitis C virus NS3 protein and syphilis T. pallidum p47 protein in serum. MADAs, including DeLISAs, require, besides the requisite biomolecules and amplification reagents, minimal specialized equipment (two permanent magnets, a ruler or a capillary with calibrated length markings) and no electrical power to obtain a quantitative readout of analyte concentration. With further development, the method may be useful in resource-limited or point-of-care settings.

Synthesis of 125I Labeled Estradiol-17-Hemisuccinate and Its Binding Study to Estrogen Receptors Using Scintillation Proximity Assay Method

Directory of Open Access Journals (Sweden)

Y. Susilo

2012-12-01

Full Text Available Research was carried out to obtain a selective ligand which strongly bind to estrogen receptors through determination of binding affinity of estradiol-17β-hemisuccinate. Selectivity of these compounds for estrogen receptor was studied using Scintillation Proximity Assay (SPA method. Primary reagents required in the SPA method including radioligand and receptor, the former was obtained by labeling of estradiol-17β-hemisuccinate with 125I, while MCF7 was used as the receptor. The labeling process was performed by indirect method via two-stage reaction. In this procedure, first step was activation of estradiol-17β-hemisuccinate using isobutylchloroformate and tributylamine as a catalist, while labeling of histamine with 125I was carried out using chloramin-T method to produce 125I-histamine. The second stage was conjugation of activated estradiol-17β-hemisuccinate with 125I-histamine. The product of estradiol-17β-hemisuccinate labeled 125I was extracted using toluene. Furtherly, the organic layer was purified by TLC system. Characterization of estradiol-17β-hemisuccinate labeled 125I from this solvent extraction was carried out by determining its radiochemical purity and the result was obtained using paper electrophoresis and TLC were 79.8% and 84.4% respectively. Radiochemical purity could be increased when purification step was repeated using TLC system, the result showed up to 97.8%. Determination of binding affinity by the SPA method was carried out using MCF7 cell lines which express estrogen receptors showed the value of Kd at 7.192 x 10-3 nM and maximum binding at 336.1 nM. This low value of Kd indicated that binding affinity of estradiol-17β-hemisuccinate was high or strongly binds to estrogen recepto

Effect of varying the exposure and 3H-thymidine labeling period upon the outcome of the primary hepatocyte DNA repair assay

International Nuclear Information System (INIS)

Barfknecht, T.R.; Mecca, D.J.; Naismith, R.W.

1988-01-01

The results presented in this report demonstrate that an 18-20 hour exposure/ 3 H-thymidine DNA labeling period is superior to a 4 hour incubation interval for general genotoxicity screening studies in the rat primary hepatocyte DNA repair assay. When DNA damaging agents which give rise to bulky-type DNA base adducts such as 2-acetylaminofluorene, aflatoxin B1 and benzidine were evaluated, little or no difference was observed between the 4 hour or an 18-20-hour exposure/labeling period. Similar results were also noted for the DNA ethylating agent diethylnitrosamine. However, when DNA damaging chemicals which produce a broader spectrum of DNA lesions were studied, differences in the amount of DNA repair as determined by autoradiographic analysis did occur. Methyl methanesulfonate and dimethylnitrosamine induced repairable DNA damage that was detected at lower dose levels with the 18-20 hour exposure/labeling period. Similar results were also observed for the DNA cross-linking agents, mitomycin C and nitrogen mustard. Ethyl methanesulfonate produced only a marginal amount of DNA repair in primary hepatocytes up to a dose level of 10(-3) M during the 4 hour incubation period, whereas a substantial amount of DNA repair was detectable at a dose level of 2.5 X 10(-4) M when the 18-20 hour exposure/labeling period was employed. The DNA alkylating agent 4-nitroquinoline-1-oxide, which creates DNA base adducts that are slowly removed from mammalian cell DNA, induced no detectable DNA repair in hepatocytes up to a toxic dose level of 2 X 10(-5) M with the 4 hour exposure period, whereas a marked DNA repair response was observed at 10(-5) M when the 18-20 hour exposure/labeling period was used

Preparation and Characterization of Nicke-iron Alloy Film as Freestanding Electrode for Oxygen Evolution Reaction

Directory of Open Access Journals (Sweden)

Yao Mengqi

2018-01-01

Full Text Available This work reports the porous nicke-iron alloy film supported on stainless steel mesh as freestanding electrode for enhanced oxygen evolution reaction (OER catalyst prepared from an one step electrodeposition method. Results indicated that the porous nickle-iron alloy film exhibits a low overpotential of 270 mV at 10 mA cm-2 and excellent electroconductibility. The superior OER properties can be attributed to its novel synthetic process, conductive substrate and porous structure. This work will provide a new strategy to fabricate alloy film for OER electrocatalyst.

The singer and the song: Nick Cave and the archetypal function of the cover version

OpenAIRE

Wiseman-Trowse, Nathan J B

2013-01-01

Throughout his career, from The Boys Next Door, through The Birthday Party, and with The Bad Seeds, Australian singer / songwriter Nick Cave has balanced his own set of creative voices alongside those of others through his choice of cover versions. Cave’s 1986 album with The Bad Seeds, ‘Kicking Against the Pricks’, is a collection of cover versions that spans American folk idioms (‘Black Betty’, ‘Hey Joe’, ‘The Singer’), Tin-Pan-Alley balladeering (‘Something’s Gotten Hold of my Heart’, ‘By t...

Choice of radionuclide for antibody labelling: new perspectives

International Nuclear Information System (INIS)

Hazra, D.K.; Dass, S.

1983-01-01

The expanding horizons of labelled antibody techniques in diagnostic imaging or assay, therapy and research and the availabilities of monoclonal antibodies is resulting in a demand for suitable radionuclides as antibody labels. An outline is given of the different criteria for choosing an appropriate radionuclide for labelling an antibody depending on its particular field of use. The requirements of procedures for firmly linking radionuclides to antibodies are also given. (U.K.)

Pi overlapping ring systems contained in a homogeneous assay: a novel homogeneous assay for antigens

Science.gov (United States)

Kidwell, David A.

1993-05-01

A novel immunoassay, Pi overlapping ring systems contained in a homogeneous assay (PORSCHA), is described. This assay relies upon the change in fluorescent spectral properties that pyrene and its derivatives show with varying concentration. Because antibodies and other biomolecules can bind two molecules simultaneously, they can change the local concentration of the molecules that they bind. This concentration change may be detected spectrally as a change in the fluorescence emission wavelength of an appropriately labeled biomolecule. Several tests of PORSCHA have been performed which demonstrate this principle. For example: with streptavidin as the binding biomolecule and a biotin labeled pyrene derivative, the production of the excimer emitting at 470 nm is observed. Without the streptavidin present, only the monomer emitting at 378 and 390 nm is observed. The ratio of monomer to excimer provides the concentration of unlabeled biotin in the sample. Approximately 1 ng/mL of biotin may be detected with this system using a 50 (mu) l sample (2 X 10-16 moles biotin). The principles behind PORSCHA, the results with the streptavidin/biotin system are discussed and extensions of the PORSCHA concept to antibodies as the binding partner and DNA in homogeneous assays are suggested.

Radioreceptor assay for insulin

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Kazuo [Tokyo Univ. (Japan). Faculty of Medicine

1975-04-01

Radioreceptor assay of insulin was discussed from the aspects of the measuring method, its merits and problems to be solved, and its clinical application. Rat liver 10 x g pellet was used as receptor site, and enzymatic degradation of insulin by the system contained in this fraction was inhibited by adding 1 mM p-CMB. /sup 125/I-labelled porcine insulin was made by lactoperoxidase method under overnight incubation at 4/sup 0/C and later purification by Sephadex G-25 column and Whatman CF-11 cellulose powder. Dog pancreatic vein serum insulin during and after the glucose load was determined by radioreceptor assay and radioimmunoassay resulting that both measurements accorded considerably. Radioreceptor assay would clarify the pathology of disorders of glucose metabolism including diabetes.

Automatic extraction of drug indications from FDA drug labels.

Science.gov (United States)

Khare, Ritu; Wei, Chih-Hsuan; Lu, Zhiyong

2014-01-01

Extracting computable indications, i.e. drug-disease treatment relationships, from narrative drug resources is the key for building a gold standard drug indication repository. The two steps to the extraction problem are disease named-entity recognition (NER) to identify disease mentions from a free-text description and disease classification to distinguish indications from other disease mentions in the description. While there exist many tools for disease NER, disease classification is mostly achieved through human annotations. For example, we recently resorted to human annotations to prepare a corpus, LabeledIn, capturing structured indications from the drug labels submitted to FDA by pharmaceutical companies. In this study, we present an automatic end-to-end framework to extract structured and normalized indications from FDA drug labels. In addition to automatic disease NER, a key component of our framework is a machine learning method that is trained on the LabeledIn corpus to classify the NER-computed disease mentions as "indication vs. non-indication." Through experiments with 500 drug labels, our end-to-end system delivered 86.3% F1-measure in drug indication extraction, with 17% improvement over baseline. Further analysis shows that the indication classifier delivers a performance comparable to human experts and that the remaining errors are mostly due to disease NER (more than 50%). Given its performance, we conclude that our end-to-end approach has the potential to significantly reduce human annotation costs.

Sensitive electrochemical monitoring of nucleic acids coupling DNA nanostructures with hybridization chain reaction

International Nuclear Information System (INIS)

Zhuang, Junyang; Fu, Libing; Xu, Mingdi; Yang, Huanghao; Chen, Guonan; Tang, Dianping

2013-01-01

Graphical abstract: -- Highlights: •A new signal-on metallobioassay was developed for detection of nucleic acids. •Target-triggered long-range self-assembled DNA nanostructures are used for amplification of electronic signal. •Hybridization chain reaction is utilized for construction of long-range DNA nanostructures. -- Abstract: Methods based on metal nanotags have been developed for metallobioassay of nucleic acids, but most involve complicated labeling or stripping procedures and are unsuitable for routine use. Herein, we report the proof-of-concept of a novel and label-free metallobioassay for ultrasensitive electronic determination of human immunodeficiency virus (HIV)-related gene fragments at an ultralow concentration based on target-triggered long-range self-assembled DNA nanostructures and DNA-based hybridization chain reaction (HCR). The signal is amplified by silver nanotags on the DNA duplex. The assay mainly consists of capture probe, detection probe, and two different DNA hairpins. In the presence of target DNA, the capture probe immobilized on the sensor sandwiches target DNA with the 3′ end of detection probe. Another exposed part of detection probe at the 5′ end opens two alternating DNA hairpins in turn, and propagates a chain reaction of hybridization events to form a nicked double-helix. Finally, numerous silver nanotags are immobilized onto the long-range DNA nanostructures, each of which produces a strong electronic signal within the applied potentials. Under optimal conditions, the target-triggered long-range DNA nanostructures present good electrochemical behaviors for the detection of HIV DNA at a concentration as low as 0.5 fM. Importantly, the outstanding sensitivity can make this approach a promising scheme for development of next-generation DNA sensors without the need of enzyme labeling or fluorophore labeling

Label-free detection of kanamycin based on a G-quadruplex DNA aptamer-based fluorescent intercalator displacement assay

Science.gov (United States)

Xing, Yun-Peng; Liu, Chun; Zhou, Xiao-Hong; Shi, Han-Chang

2015-01-01

This work was the first to report that the kanamycin-binding DNA aptamer (5'-TGG GGG TTG AGG CTA AGC CGA-3') can form stable parallel G-quadruplex DNA (G4-DNA) structures by themselves and that this phenomenon can be verified by nondenaturing polyacrylamide gel electrophoresis and circular dichroism spectroscopy. Based on these findings, we developed a novel label-free strategy for kanamycin detection based on the G4-DNA aptamer-based fluorescent intercalator displacement assay with thiazole orange (TO) as the fluorescence probe. In the proposed strategy, TO became strongly fluorescent upon binding to kanamycin-binding G4-DNA. However, the addition of kanamycin caused the displacement of TO from the G4-DNA-TO conjugate, thereby resulting in decreased fluorescent signal, which was inversely related to the kanamycin concentration. The detection limit of the proposed assay decreased to 59 nM with a linear working range of 0.1 μM to 20 μM for kanamycin. The cross-reactivity against six other antibiotics was negligible compared with the response to kanamycin. A satisfactory recovery of kanamycin in milk samples ranged from 80.1% to 98.0%, confirming the potential of this bioassay in the measurement of kanamycin in various applications. Our results also served as a good reference for developing similar fluorescent G4-DNA-based bioassays in the future.

Assay for vitamin B12 absorption and method of making labeled vitamin B12

Science.gov (United States)

Anderson, Peter J [Davis, CA; Dueker, Stephen [Davis, CA; Miller, Joshua [Davis, CA; Green, Ralph [Elmacero, CA; Roth, John [Davis, CA; Carkeet, Colleen [Silver Spring, MD; Buchholz,; Bruce, A [Orinda, CA

2012-06-19

The invention provides methods for labeling vitamin B12 with .sup.14C, .sup.13C, tritium, and deuterium. When radioisotopes are used, the invention provides for methods of labeling B12 with high specific activity. The invention also provides labeled vitamin B12 compositions made in accordance with the invention.

Effects of Urtica dioica on oxidative stress, proliferation and apoptosis after partial hepatectomy in rats.

Science.gov (United States)

Oguz, Serhat; Kanter, Mehmet; Erboga, Mustafa; Toydemir, Toygar; Sayhan, Mustafa Burak; Onur, Hatice

2015-05-01

The present study was performed to investigate the effect of Urtica dioica (UD) on liver regeneration after partial hepatectomy (PH) in rats. A total of 24 male Sprague Dawley rats were divided into three groups: sham-operated, PH and PH + UD; each group contains eight animals. The rats in UD-treated groups were given UD oils (2 ml/kg/day) once a day orally for 7 days starting 3 days prior to hepatectomy operation. At day 7 after resection, liver samples were collected. The levels of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) were estimated in liver homogenates. Moreover, histopathological examination, mitotic index (MI), proliferating cell nuclear antigen labeling, proliferation index (PI), transferase-mediated deoxyuridine triphosphate nick end-labeling assay, apoptotic index (AI) were evaluated at day 7 after hepatectomy. As a result, UD significantly increased MI and PI, significantly decreased AI and also attenuated hepatic vacuolar degeneration and sinusoidal congestion in PH rats. UD treatment significantly decreased the elevated tissue MDA level and increased the reduced SOD activity and GSH level in the tissues. These results suggest that UD pretreatment was beneficial for rat liver regeneration after partial hepatectomy. © The Author(s) 2013.

Development of direct competitive biomimetic immunosorbent assay based on quantum dot label for determination of trichlorfon residues in vegetables.

Science.gov (United States)

Liu, Qiurui; Jiang, Mingdi; Ju, Zeliang; Qiao, Xuguang; Xu, Zhixiang

2018-06-01

A direct competitive biomimetic immunosorbent assay method based on molecularly imprinted polymer was developed for the determination of trichlorfon. A CdSe/ZnS quantum dot label was used as the marker. The hydrophilic imprinted film was synthesized directly on the surface of a 96-well plate, and characterized by Fourier-transform infrared spectroscopy and thermo-gravimetric analyses. The method exhibited high stability, selectivity, and sensitivity. Under optimal conditions, the limits of detection and sensitivity of the biomimetic immunosorbent assay method were 9.0 μg L -1 and 5.0 mg L -1 (0.1 mg kg -1 and 62.5 mg kg -1 for vegetable sample), respectively. Low cross-reactivity values of 19.2% and 15.6% were obtained for the structural analogues. Spinach and rape samples spiked with trichlorfon were extracted and determined by this method with recoveries ranging from 83.6% to 91.1%. The method was applied for the detection of trichlorfon residues in leek and cucumber samples, and results correlated well with those obtained using GC. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantitative Measurement of GPCR Endocytosis via Pulse-Chase Covalent Labeling.

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Hidetoshi Kumagai

Full Text Available G protein-coupled receptors (GPCRs play a critical role in many physiological systems and represent one of the largest families of signal-transducing receptors. The number of GPCRs at the cell surface regulates cellular responsiveness to their cognate ligands, and the number of GPCRs, in turn, is dynamically controlled by receptor endocytosis. Recent studies have demonstrated that GPCR endocytosis, in addition to affecting receptor desensitization and resensitization, contributes to acute G protein-mediated signaling. Thus, endocytic GPCR behavior has a significant impact on various aspects of physiology. In this study, we developed a novel GPCR internalization assay to facilitate characterization of endocytic GPCR behavior. We genetically engineered chimeric GPCRs by fusing HaloTag (a catalytically inactive derivative of a bacterial hydrolase to the N-terminal end of the receptor (HT-GPCR. HaloTag has the ability to form a stable covalent bond with synthetic HaloTag ligands that contain fluorophores or a high-affinity handle (such as biotin and the HaloTag reactive linker. We selectively labeled HT-GPCRs at the cell surface with a HaloTag PEG ligand, and this pulse-chase covalent labeling allowed us to directly monitor the relative number of internalized GPCRs after agonist stimulation. Because the endocytic activities of GPCR ligands are not necessarily correlated with their agonistic activities, applying this novel methodology to orphan GPCRs, or even to already characterized GPCRs, will increase the likelihood of identifying currently unknown ligands that have been missed by conventional pharmacological assays.

Thermometric enzyme linked immunosorbent assay: TELISA.

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Mattiasson, B; Borrebaeck, C; Sanfridson, B; Mosbach, K

1977-08-11

A new method, thermometric enzyme linked immunosorbent assay (TELISA), for the assay of endogenous and exogenous compounds in biological fluids is described. It is based on the previously described enzyme linked immunosorbent assay technique, ELISA, but utilizes enzymic heat formation which is measured in an enzyme thermistor unit. In the model system studied determination of human serum albumin down to a concentration of 10(-10) M (5 ng/ml) was achieved, with both normal and catalase labelled human serum albumin competing for the binding sites on the immunosorbent, which was rabbit antihuman serum albumin immobilized onto Sepharose CL-4B.

A rapid radioimmunoassay using 125I-labeled staphylococcal protein A for antibody to varicella-zoster virus

International Nuclear Information System (INIS)

Richman, D.D.; Cleveland, P.H.; Oxman, M.N.; Zaia, J.A.

1981-01-01

A sensitive radioimmunoassay for serum antibody to varicella-zoster virus is described; it uses 125I-labeled staphylococcal protein A and a specially designed immunofiltration apparatus. The assay accurately distinguishes between individuals who are susceptible and those who are immune to infection with varicella-zoster virus. In addition, it can detect passive antibody in recipients of varicella-zoster immune globulin. This radioimmunoassay also detects the heterologous antibody responses that occasionally occur in patients infected with herpes simplex virus, which also have been detected by other antibody assays. The particular advantages of this assay are the use of noninfectious reagents, the speed of execution (less than 3 hr), the requirement for only small quantities of serum (30 microliters), the objectivity of end-point determination, and the capability of screening large numbers of sera. Consequently, this radioimmunoassay is especially useful for the rapid identification of susceptible individuals, which is essential for the appropriate management of patients and hospital personnel after exposure to varicella

Gamma aminobutyric acid radioreceptor assay: a confirmatory quantitative assay for toxaphene in environmental and biological samples

International Nuclear Information System (INIS)

Saleh, M.A.; Blancato, J.N.

1993-01-01

Toxaphene is a complex mixture of polychlorinated monoterpenes, and was found to be acutely and chronically toxic to aquatic and wild life and posed a carcinogenic risk to humans before its ban in 1982. However, it is still found in the environment due to its relative persistence with an estimated half life time of about 10 years in soils. Toxaphenes neurotoxicity is attributed to a few isomers with a mode of action through binding to the chloride channel of the gamma-aminobutyric acid (GABA) receptor ionophore complex. [ 35 S] tertiary butylbicyclophosphorothionate (TBPS) with specific activity higher than 60 Ci/mmole has a high binding affinity to the same sites and is now commercially available and can be used to label the GABA receptor for the development of radioreceptor assay technique. The GABA receptor was prepared by a sequence of ultra centrifugation and dialysis of mammalian (rats, cows, catfish and goats) brain homogenates. The receptor is then labeled with [ 35 S] TBPS and the assay was conducted by measuring the displacement of radioactivity following incubation with the sample containing the analytes. The assay is fast, sensitive and requires very little or no sample preparation prior to the analysis. (Author)

Direct 125I-radioligand assays for serum progesterone compared with assays involving extraction of serum

International Nuclear Information System (INIS)

Ratcliffe, W.A.; Corrie, J.E.T.; Dalziel, A.H.; Macpherson, J.S.

1982-01-01

Two direct radioimmunoassays for progesterone in 50 μL of unextracted serum or plasma with assays involving extraction of serum were compared. The direct assays include the use of either danazol at pH 7.4 or 8-anilino-1-naphthalenesulfonic acid at pH 4.0 to displace progesterone from serum binding-proteins. Progesterone is then assayed by using an antiserum to a progesterone 11α-hemisuccinyl conjugate and the radioligand 125 I-labeled progesterone 11α-glucuronyl tyramine, with separation by double-antibody techniques. Direct assays with either displacing agent gave good analytical recovery of progesterone added to human serum, and progesterone values for patients' specimens correlated well (r > 0.96) with results of assays involving extraction of serum. Precision was similar with each displacing agent over the working range 2.5-100 nmol/L and superior to that of extraction assays. We conclude that these direct assays of progesterone are analytically valid and more robust, precise, and technically convenient than many conventional methods involving extraction of serum

Using micro-quantity of chloramine T in chicken pro-latin labelling and radioimmunoassay

International Nuclear Information System (INIS)

Shi Zhendan; Huang Zuhan

2000-01-01

A radioimmunoassay was developed for measurement of chicken plasma prolactin. The assay used chPRL(AFP-10328B) as reference standard, chPRL(AFP-4444B) as the radio labelled ligand, rabbit anti-chicken PRL (AFP-151040789) as first antibody, and donkey anti-rabbit IgG antiserum as second antibody. For iodide ratio labelling of chicken PRL, a modified chloramine T method which reduced the amount of chloramine T and omitted sodium metabisulfite, and produced the labelled hormone with a specific activity of 29μCi/μg was used. The assay sensitivity was 0.34 ng/ml. the ED75, ED50 and ED25 of standard curve were 1.30, 3.71 and 10.60 ng/ml, respectively. Both coefficients of variations between and within assay were less than 15%. Serial dilutions of chicken samples showed a parallel inhibition curve to that of the standards. Plasma PRL concentrations of samples from hens at different reproductive states measured by this assay revealed significant differences and rational changing trends. These results validate the assay

Depressed Immune Responses and Accelerated Splenic Apoptosis due to Experience of Food Deprivation and Inequality but not Unstable Social Status in Balb/c Mice.

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Aghajani, Marjan; Vaez Mahdavi, Mohammad Reza; Najafabadi, Mohsen Khalili; Ghazanfari, Tooba; Moradi, Fatemeh; Golchoobian, Ravieh; Askari, Hasan; Sanadgol, Nima; Moghaddam, Ehsan Kazemi

2017-01-01

We aimed to show that the immune system is sensitive to the detrimental effects of inequality and social injustice, and splenic vulnerability to apoptosis may also increase. In order of better determination of immune responses to chronic social stress, we implemented food deprivation, food intake inequality, and unstable social status (a change of cage-mate every 3 days) for a period of 14 days in 60 male Balb/c mice. At the end of this stress period, nitric oxide (NO) production by peritoneal adherent cells and the serum concentration of corticosterone were measured. Moreover, the viability of peritoneal adherent cells and spleen lymphocytes was evaluated by MTT assay. The terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay was done to reveal the TUNEL-reactive apoptotic bodies in the spleen. Our results showed that food deprivation and inequality caused significant changes in the apoptosis of splenic cells in comparison with the control group (p social status did not cause a further increase in the viability of lymphocytes and peritoneal adherent cells, or NO production in animals that were food-deprived or experienced inequality. Serum concentration of corticosterone in all experimental groups, except for animals that experienced unstable social status only, significantly decreased versus the control group (p poverty and social inequality, but not unstable social status, affect immune responses and are likely involved in the induction of splenic apoptosis in mice. © 2017 S. Karger AG, Basel.

Ethanol extract of Portulaca Oleracea L. reduced the carbon tetrachloride induced liver injury in mice involving enhancement of NF-κB activity

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Shi, Hongguang; Liu, Xuefeng; Tang, Gusheng; Liu, Haiyan; Zhang, Yinghui; Zhang, Bo; Zhao, Xuezhi; Wang, Wanyin

2014-01-01

Acute hepatic injury causes high morbidity and mortality world-wide. Management of severe acute hepatic failure continues to be one of the most challenging problems in clinical medicine. In present study, carbon tetrachloride (CCl4) was used to induce acute liver damage in mice and the protective effects of ethanol extract of Portulaca Oleracea L. (PO) were examined. The aminotransferase activities were biochemical estimated and the liver damage was tested by morphological histological analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. The role of PO on the activity of NF-κB was determined by luciferase reporter gene assay and immunohistochemistry. The level of p-p65 was tested by western blot. Our results showed that PO administration on mice would decrease the serum aminotransferase level and reduced the liver histological damage. We also found that nuclear translocation of p65 was enhanced in liver tissues of mice treated with PO compared with control animals. In addition, in cultured hepatic cells, PO increased the NF-κB luciferase reporter gene activity and upregulated the level of phosphorylation of p65, but had no effects on mice liver SOD activity and MDA level. Collectively, PO attenuated CCl4 induced mice liver damage by enhancement of NF-κB activity. PMID:25628785

Histone Modification Is Involved in Okadaic Acid (OA Induced DNA Damage Response and G2-M Transition Arrest in Maize.

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Hao Zhang

Full Text Available Histone modifications are involved in regulation of chromatin structure. To investigate the relationship between chromatin modification and cell cycle regulation during plant cell proliferation, Okadaic acid (OA, a specific inhibitor of serine/threonine protein phosphatase, was applied in this study. The results showed that OA caused the cell cycle arrest at preprophase, leading to seedling growth inhibition. Western blotting assay revealed that the spatial distribution of phosphorylation of Ser10 histone H3 tails (H3S10ph signals was altered under OA treatment. Reactive oxygen species (ROS was found to be at higher levels and TdT-mediated dUTP nick end labeling (TUNEL assay displayed DNA breaks happened at the chromatin after treatment with OA, companied with an increase in the acetylation of histone H4 at lysine 5 (H4K5ac level. From these observations, we speculated that the alteration of the spatial distribution of H3S10ph and the level of H4K5ac was involved in the procedure that OA induced DNA breaks and G2-M arrested by the accumulation of ROS, and that the histone H3S10ph and H4K5ac might facilitate DNA repair by their association with the chromatin decondensation.

Apoptosis induction of human endometriotic epithelial and stromal cells by noscapine

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Mohammad Rasoul Khazaei

2016-09-01

Full Text Available Objective(s: Endometriosis is a complex gynecologic disease with unknown etiology. Noscapine has been introduced as a cancer cell suppressor. Endometriosis was considered as a cancer like disorder, The aim of present study was to investigate noscapine apoptotic effect on human endometriotic epithelial and stromal cells in vitro. Materials and Methods:In this in vitro study, endometrial biopsies from endometriosis patients (n=9 were prepared and digested by an enzymatic method (collagenase I, 2 mg/ml. Stromal and epithelial cells were separated by sequential filtration through a cell strainer and ficoll layering. The cells of each sample were divided into five groups: control (0, 10, 25, 50 and 100 micromole/liter (µM concentration of noscapine and were cultured for three different periods of times; 24, 48 and 72 hr. Cell viability was assessed by colorimetric assay. Nitric oxide (NO concentration was measured by Griess reagent. Cell death was analyzed by Acridine Orange (AO–Ethidium Bromide (EB double staining and Terminal deoxynucleotidyl transferase (TdT dUTP Nick-End Labeling (TUNEL assay. Data were analyzed by one-way ANOVA. Results: Viability of endometrial epithelial and stromal cells significantly decreased in 10, 25, 50 and 100 µM noscapine concentration in 24, 48, 72 hr (P

Sperm DNA fragmentation, recurrent implantation failure and recurrent miscarriage

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Carol Coughlan

2015-01-01

Full Text Available Evidence is increasing that the integrity of sperm DNA may also be related to implantation failure and recurrent miscarriage (RM. To investigate this, the sperm DNA fragmentation in partners of 35 women with recurrent implantation failure (RIF following in vitro fertilization, 16 women diagnosed with RM and seven recent fathers (control were examined. Sperm were examined pre- and post-density centrifugation by the sperm chromatin dispersion (SCD test and the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay. There were no significant differences in the age of either partner or sperm concentration, motility or morphology between three groups. Moreover, there were no obvious differences in sperm DNA fragmentation measured by either test. However, whilst on average sperm DNA fragmentation in all groups was statistically lower in prepared sperm when measured by the SCD test, this was not seen with the results from the TUNEL assay. These results do not support the hypothesis that sperm DNA fragmentation is an important cause of RIF or RM, or that sperm DNA integrity testing has value in such patients. It also highlights significant differences between test methodologies and sperm preparation methods in interpreting the data from sperm DNA fragmentation tests.

Alpha-2 agonist attenuates ischemic injury in spinal cord neurons.

Science.gov (United States)

Freeman, Kirsten A; Puskas, Ferenc; Bell, Marshall T; Mares, Joshua M; Foley, Lisa S; Weyant, Michael J; Cleveland, Joseph C; Fullerton, David A; Meng, Xianzhong; Herson, Paco S; Reece, T Brett

2015-05-01

Paraplegia secondary to spinal cord ischemia-reperfusion injury remains a devastating complication of thoracoabdominal aortic intervention. The complex interactions between injured neurons and activated leukocytes have limited the understanding of neuron-specific injury. We hypothesize that spinal cord neuron cell cultures subjected to oxygen-glucose deprivation (OGD) would simulate ischemia-reperfusion injury, which could be attenuated by specific alpha-2a agonism in an Akt-dependent fashion. Spinal cords from perinatal mice were harvested, and neurons cultured in vitro for 7-10 d. Cells were pretreated with 1 μM dexmedetomidine (Dex) and subjected to OGD in an anoxic chamber. Viability was determined by MTT assay. Deoxyuridine-triphosphate nick-end labeling staining and lactate dehydrogenase (LDH) assay were used for apoptosis and necrosis identification, respectively. Western blot was used for protein analysis. Vehicle control cells were only 59% viable after 1 h of OGD. Pretreatment with Dex significantly preserves neuronal viability with 88% viable (P control cells by 50% (P neuron cell culture, OGD mimics neuronal metabolic derangement responsible for paraplegia after aortic surgery. Dex preserves neuronal viability and decreases apoptosis in an Akt-dependent fashion. Dex demonstrates clinical promise for reducing the risk of paraplegia after high-risk aortic surgery. Copyright © 2015 Elsevier Inc. All rights reserved.

Radiosotopic assay and binder therefor

International Nuclear Information System (INIS)

Caston, J.D.; Kamen, B.A.

1976-01-01

A rapid and less costly radioisotopic assay for measuring the concentration of folate in blood serum is described. This procedure utilizes 3 H-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

Isotope release cytotoxicity assay applicable to human tumors: the use of 111-indium

Energy Technology Data Exchange (ETDEWEB)

Frost, P; Wiltrout, R; Maciorowski, Z; Rose, N R

1977-01-01

We have demonstrated that human tumors can be labelled efficiently with the 111indium-oxine chelate. Subsequently, this isotope can be released by cytotoxic lymphoid cells. Both natural and induced cytotoxicity can be demonstrated utilizing this isotope release method. Because of the slow spontaneous release of 111indium and its efficient labelling of human tumor cells, this isotope release assay can be utilized in long-term cytotoxic assays in the study of human tumor immunology.

The relationship between apoptosis and the expression of proliferating cell nuclear antigen and the clinical stages in gastric carcinoma.

Science.gov (United States)

Tao, K; Chen, D; Tian, Y; Lu, X; Yang, X

2000-01-01

The relationship between the apoptosis and the expression of proliferating cell nuclear antigen (PCNA) and the clinical stages in gastric cancers was studied. By using terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) technique and PCNA immunohistochemical staining, the apoptosis and the expression of PCNA in tissue of gastric carcinoma were assayed in situ, the index of apoptosis (AI), index of PCNA (PI) and the rate of AI/PI were calculated. AI and PI in gastric cancer tissues were (6.5 +/- 3.7)% and (49.8 +/- 15.9)% respectively, and the rate of AI/PI was 0.13 +/- 0.05, which were obviously different from those of normal gastric mucosa in paragastric cancer (P stages of gastric carcinoma, the AI was decreased, PI was increased and the rate of AI/PI decreased in gastric carcinoma. There was significant difference in them between the gastric cancer tissues and normal gastric mucosa in pericarcinoma in TNM stage II to IV (P gastric carcinoma. The AI, PI and the rate of AI/PI would become the prognostic factors in advanced gastric carcinoma.

Effects of Hormone Deprivation, 2-Methoxyestradiol Combination Therapy on Hormone-Dependent Prostate Cancer In Vivo

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Fuminori Sato

2005-09-01

Full Text Available 2-Methoxyestradiol (2-ME has potent anti proliferative effects on cancer cells. Its utility alone or in combination with other therapies for treating prostate cancer, however, has not been fully explored. Androgendependent, independent human prostate cancer cells were examined in vivo for their response to combination therapy. Efficacy was assessed by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling assay, measuring microvessel density (MVD in excised tumors. Animals harboring hormonedependent tumors treated with 2-ME alone, androgen deprivation therapy alone, or the combination of the two had a 3.1-fold, 5.3-fold, 10.1-fold increase in apoptosis, respectively. For hormone-independent tumors, treatment with 2-ME resulted in a 2.43-fold increase in apoptosis, a 73% decrease in MVD. 2-ME was most effective against hormone-dependent tumors in vivo, combination therapy resulted in a significant increase in efficacy compared to no treatment controls, trended toward greater efficacy than either 2-ME or androgen deprivation alone. Combination therapy should be investigated further as an additional therapeutic option for early prostate cancer.

The Root Extract of Gentiana macrophylla Pall. Alleviates Cardiac Apoptosis in Lupus Prone Mice.

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Chih-Yang Huang

Full Text Available The roots of the perennial herb Gentiana macrophylla Pall. (GM are known as Qinjiao, which has been used for centuries to treat systemic lupus erythematosus (SLE. However, little is known about the effects of GM on cholesterol-aggravated cardiac abnormalities in SLE, and the mechanisms thereof. This study investigates whether GM exhibits anti-apoptotic effects, focusing on the left ventricle (LV of NZB/W F1 mice fed with high-cholesterol diet. The morphology and apoptotic status of ventricular tissues were determined by microscopy and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay. Levels of apoptotic biomarkers were determined by immunoblotting. The results thus obtained revealed that GM significantly reduced the cholesterol-aggravated apoptosis of LV in NZB/W F1 mice by suppressing both intrinsic and extrinsic apoptotic pathways. Additionally, GM significantly increased the cardiac insulin-like growth factors (IGF-1 survival signaling and anti-apoptotic proteins in LV tissues. Accordingly, GM is considered to be beneficial in alleviating cholesterol-aggravated cardiac damage in SLE, and therefore constitute an alternative treatment for SLE patients with cardiac abnormalities.

Abnormal development of tapetum and microspores induced by chemical hybridization agent SQ-1 in wheat.

Science.gov (United States)

Wang, Shuping; Zhang, Gaisheng; Song, Qilu; Zhang, Yingxin; Li, Zheng; Guo, Jialin; Niu, Na; Ma, Shoucai; Wang, Junwei

2015-01-01

Chemical hybridization agent (CHA)-induced male sterility is an important tool in crop heterosis. To demonstrate that CHA-SQ-1-induced male sterility is associated with abnormal tapetal and microspore development, the cytology of CHA-SQ-1-treated plant anthers at various developmental stages was studied by light microscopy, scanning and transmission electron microscopy, in situ terminal deoxynucleotidyl transferasemediated dUTP nick end-labelling (TUNEL) assay and DAPI staining. The results indicated that the SQ-1-treated plants underwent premature tapetal programmed cell death (PCD), which was initiated at the early-uninucleate stage of microspore development and continued until the tapetal cells were completely degraded; the process of microspore development was then blocked. Microspores with low-viability (fluorescein diacetate staining) were aborted. The study suggests that premature tapetal PCD is the main cause of pollen abortion. Furthermore, it determines the starting period and a key factor in CHA-SQ-1-induced male sterility at the cell level, and provides cytological evidence to further study the mechanism between PCD and male sterility.

Abnormal development of tapetum and microspores induced by chemical hybridization agent SQ-1 in wheat.

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Shuping Wang

Full Text Available Chemical hybridization agent (CHA-induced male sterility is an important tool in crop heterosis. To demonstrate that CHA-SQ-1-induced male sterility is associated with abnormal tapetal and microspore development, the cytology of CHA-SQ-1-treated plant anthers at various developmental stages was studied by light microscopy, scanning and transmission electron microscopy, in situ terminal deoxynucleotidyl transferasemediated dUTP nick end-labelling (TUNEL assay and DAPI staining. The results indicated that the SQ-1-treated plants underwent premature tapetal programmed cell death (PCD, which was initiated at the early-uninucleate stage of microspore development and continued until the tapetal cells were completely degraded; the process of microspore development was then blocked. Microspores with low-viability (fluorescein diacetate staining were aborted. The study suggests that premature tapetal PCD is the main cause of pollen abortion. Furthermore, it determines the starting period and a key factor in CHA-SQ-1-induced male sterility at the cell level, and provides cytological evidence to further study the mechanism between PCD and male sterility.

Population control of resident and immigrant microglia by mitosis and apoptosis

DEFF Research Database (Denmark)

Wirenfeldt, Martin; Dissing-Olesen, Lasse; Babcock, Alicia

2007-01-01

microglia often occurred in clusters, some having recently incorporated bromodeoxyuridine, showing that proliferation had occurred. Annexin V labeling and staining for activated caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling showed that apoptotic mechanisms participate...... in dissolution of the microglial response. Using bone marrow chimeric mice, we found that the lesion-induced proliferative capacity of resident microglia superseded that of immigrant microglia, whereas lesion-induced kinetics of apoptosis were comparable. Microglial numbers and responses were severely reduced...... in bone marrow chimeric mice. These results broaden our understanding of the microglial response to neural damage by demonstrating that simultaneously occurring mitosis and apoptosis regulate expansion and reduction of both resident and immigrant microglial cell populations....

Sudha Bhattacharya Jawaharlal Nehru University New Delhi

Indian Academy of Sciences (India)

TSC

Bottom strand. 1. 2. 3. G A T C. 5. 1. 3. 4. 2. *. Nicking profile of EN on the 174 bp substrate. Insertion point. Bottom strand labelled 174bp substrate. Transposon insertion point. Endonuclease nicks at three hot spots. The transposon inserts at hot spot # 3 ...

Mindtagger: A Demonstration of Data Labeling in Knowledge Base Construction.

Science.gov (United States)

Shin, Jaeho; Ré, Christopher; Cafarella, Michael

2015-08-01

End-to-end knowledge base construction systems using statistical inference are enabling more people to automatically extract high-quality domain-specific information from unstructured data. As a result of deploying DeepDive framework across several domains, we found new challenges in debugging and improving such end-to-end systems to construct high-quality knowledge bases. DeepDive has an iterative development cycle in which users improve the data. To help our users, we needed to develop principles for analyzing the system's error as well as provide tooling for inspecting and labeling various data products of the system. We created guidelines for error analysis modeled after our colleagues' best practices, in which data labeling plays a critical role in every step of the analysis. To enable more productive and systematic data labeling, we created Mindtagger, a versatile tool that can be configured to support a wide range of tasks. In this demonstration, we show in detail what data labeling tasks are modeled in our error analysis guidelines and how each of them is performed using Mindtagger.

Sensitive microplate assay for the detection of proteolytic enzymes using radiolabeled gelatin

International Nuclear Information System (INIS)

Robertson, B.D.; Kwan-Lim, G.E.; Maizels, R.M.

1988-01-01

A sensitive, microplate assay is described for the detection of a wide range of proteolytic enzymes, using radio-iodine-labeled gelatin as substrate. The technique uses the Bolton-Hunter reagent to label the substrate, which is then coated onto the wells of polyvinyl chloride microtiter plates. By measuring the radioactivity released the assay is able to detect elastase, trypsin, and collagenase in concentrations of 1 ng/ml or less, while the microtiter format permits multiple sample handling and minimizes sample volumes required for analysis

A label-free electrochemiluminescent sensor for ATP detection based on ATP-dependent ligation.

Science.gov (United States)

Zhao, Tingting; Lin, Chunshui; Yao, Qiuhong; Chen, Xi

2016-07-01

In this work, we describe a new label-free, sensitive and highly selective strategy for the electrochemiluminescent (ECL) detection of ATP at the picomolar level via ATP-induced ligation. The molecular-beacon like DNA probes (P12 complex) are self-assembled on a gold electrode. The presence of ATP leads to the ligation of P12 complex which blocks the digestion by Exonuclease III (Exo III). The protected P12 complex causes the intercalation of numerous ECL indicators (Ru(phen)3(2+)) into the duplex DNA grooves, resulting in significantly amplified ECL signal output. Since the ligating site of T4 DNA ligase and the nicking site of Exo III are the same, it involves no long time of incubation for conformation change. The proposed strategy combines the amplification power of enzyme and the inherent high sensitivity of the ECL technique and enables picomolar detection of ATP. The developed strategy also shows high selectivity against ATP analogs, which makes our new label-free and highly sensitive ligation-based method a useful addition to the amplified ATP detection arena. Copyright © 2016 Elsevier B.V. All rights reserved.

A fluorescence sedimentation assay for dsDNA antibodies

DEFF Research Database (Denmark)

Duus, K; Draborg, A H; Güven, E

2017-01-01

The Farr assay is a radioimmunoassay (RIA) for dsDNA antibodies, based on antibody precipitation using ammonium sulphate and quantification using radio-labelled dsDNA. The RIA-Farr assay offers outstanding clinical specificity and sensitivity for systemic lupus erythematosus (SLE) compared to other...... on precipitation with polyethylene glycol (PEG) and fluorescence of EvaGreen intercalated in dsDNA as detection principle. As dsDNA antibodies are quantified using fluorescence, the disadvantages of working with radioactivity are eliminated. The Fluoro-Farr assay was developed and validated, and the diagnostic...

Immunoassay of serum polypeptide hormones by using 125I-labelled anti(-immunoglobulin G) antibodies.

Science.gov (United States)

Beck, P; Nicholas, H

1975-03-01

1. A technique for indirectly labelling antibodies to polypeptide hormones, by combining them with radioactively labelled anti-(immunoglobulin G) is described. (a) 125I-labelled anti-(rabbit immunoglobulin G) and anti-(guinea-pig immunoglobulin G) antibodies with high specific radioactivity were prepared after purification of the antibodies on immunoadsorbents containing the respective antigens. (b) Rabbit immunoglobulin G antibodies to human growth hormone, porcine glucagon and guinea-pig immunoglobulin G antibodies to bovine insulin and bovine parathyroid hormone were combined with immunoadsorbents containing the respective polypeptide hormone antigen. (c) The immunoglobulin G antibodies to the polypeptide hormones were reacted with 125-I-labelled anti-(immunoglobulin G) antibodies directed against the appropriate species of immunoglobulin G,and the anti-hormone antibodies were combined with the hormone-containing immunoadsorbent. (d) 125I-labelled anti-(immunoglobulin G) antibodies and anti-hormone antibodies were simultaneously eluted from the hormone-containing immunoadsorbent by dilute HCl, pH 2.0. After elution the anti-(immunoglobulin G) antibodies and antihormone antibodies were allowed to recombine at pH 8.0 and 4 degrees C. 2. The resultant immunoglobulin G-anti-immunoglobulin G complex was used in immunoradiometric (labelled antibody) and two-site assays of the respective polypeptide hormone. 3. By using these immunoassays, concentrations down to 90pg of human growth hormone/ml, 100 pg of bovine insulin/ml, 80 pg of bovine parathyroid hormone/ml and 150 pg of glucagon/ml were readily detected. Assays of human plasma for growth hormone and insulin by these methods showed good agreement with results obtained by using a directly 125I-labelled anti-hormone antibody in an immunoradiometric assay of human growth hormone or by radioimmunoassay of human insulin. 4. The method described allows immunoradiometric or two-site assays to be performed starting with as

A Label-Free and Sensitive Fluorescent Qualitative Assay for Bisphenol A Based on Rolling Circle Amplification/Exonuclease III-Combined Cascade Amplification

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Xia Li

2016-10-01

Full Text Available Bisphenol A (BPA detection in drinking water and food packaging materials has attracted much attention since the discovery that BPA can interfere with normal physiological processes and cause adverse health effects. Here, we constructed a label-free aptamer fluorescent assay for selective and sensitive detection of BPA based on the rolling circle amplification (RCA/Exonuclease III (Exo III-combined cascade amplification strategy. First, the duplex DNA probe (RP with anti-BPA aptamer and trigger sequence was designed for BPA recognition and signal amplification. Next, under the action of BPA, the trigger probe was liberated from RP to initiate RCA reaction as primary amplification. Subsequently, the RCA products were used to trigger Exo III assisted secondary amplification with the help of hairpin probes, producing plenty of “G-quadruplex” in lantern-like structures. Finally, the continuously enriched “G-quadruplex lanterns” were lightened by zinc(II-protoporphyrin IX (ZnPPIX generating enhanced fluorescence signals. By integrating the primary RCA and secondary Exo III mediated cascade amplification strategy, this method displayed an excellent sensitivity with the detection limits of 5.4 × 10−17 M. In addition, the anti-BPA aptamer exhibits high recognition ability with BPA, guaranteeing the specificity of detection. The reporter signal probe (G-quadruplex with ZnPPIX provides a label-free fluorescence signals readout without complicated labeling procedures, making the method simple in design and cost-effective in operation. Moreover, environmental samples analysis was also performed, suggesting that our strategy was reliable and had a great potential application in environmental monitoring.

A Label-Free and Sensitive Fluorescent Qualitative Assay for Bisphenol A Based on Rolling Circle Amplification/Exonuclease III-Combined Cascade Amplification.

Science.gov (United States)

Li, Xia; Song, Juan; Xue, Qing-Wang; You, Fu-Heng; Lu, Xia; Kong, Yan-Cong; Ma, Shu-Yi; Jiang, Wei; Li, Chen-Zhong

2016-10-21

Bisphenol A (BPA) detection in drinking water and food packaging materials has attracted much attention since the discovery that BPA can interfere with normal physiological processes and cause adverse health effects. Here, we constructed a label-free aptamer fluorescent assay for selective and sensitive detection of BPA based on the rolling circle amplification (RCA)/Exonuclease III (Exo III)-combined cascade amplification strategy. First, the duplex DNA probe (RP) with anti-BPA aptamer and trigger sequence was designed for BPA recognition and signal amplification. Next, under the action of BPA, the trigger probe was liberated from RP to initiate RCA reaction as primary amplification. Subsequently, the RCA products were used to trigger Exo III assisted secondary amplification with the help of hairpin probes, producing plenty of "G-quadruplex" in lantern-like structures. Finally, the continuously enriched "G-quadruplex lanterns" were lightened by zinc(II)-protoporphyrin IX (ZnPPIX) generating enhanced fluorescence signals. By integrating the primary RCA and secondary Exo III mediated cascade amplification strategy, this method displayed an excellent sensitivity with the detection limits of 5.4 × 10 -17 M. In addition, the anti-BPA aptamer exhibits high recognition ability with BPA, guaranteeing the specificity of detection. The reporter signal probe (G-quadruplex with ZnPPIX) provides a label-free fluorescence signals readout without complicated labeling procedures, making the method simple in design and cost-effective in operation. Moreover, environmental samples analysis was also performed, suggesting that our strategy was reliable and had a great potential application in environmental monitoring.

GC-MS DETERMINATION OF RATIOS OF STABLE-ISOTOPE LABELED TO NATURAL UREA USING [(CN2)-C-13-N-15]UREA FOR STUDYING UREA KINETICS IN SERUM AND AS A MEANS TO VALIDATE ROUTINE METHODS FOR THE QUANTITATIVE ASSAY OF UREA IN DIALYSATE

NARCIS (Netherlands)

WOLTHERS, BG; TEPPER, T; WITHAG, A; NAGEL, GT; DEHAAN, THY; VANLEEUWEN, JJ; STEGEMAN, CA; HUISMAN, RM

A GC-MS determination of urea in serum or spent dialysate is described, using (CN2)-C-13-N-15-labelled urea and assaying the area ratio of labelled to natural urea by mass fragmentographic monitoring of fragments m/e 153 and 156, after its eventual conversion into the trimethylsilylether-derivative

Functional recovery in rat spinal cord injury induced by hyperbaric oxygen preconditioning.

Science.gov (United States)

Lu, Pei-Gang; Hu, Sheng-Li; Hu, Rong; Wu, Nan; Chen, Zhi; Meng, Hui; Lin, Jiang-Kai; Feng, Hua

2012-12-01

It is a common belief that neurosurgical interventions can cause inevitable damage resulting from the procedure itself in surgery especially for intramedullary spinal cord tumors. The present study was designed to examine if hyperbaric oxygen preconditioning (HBO-PC) was neuroprotective against surgical injuries using a rat model of spinal cord injury (SCI). Sprague-Dawley rats were randomly divided into three groups: HBO-PC group, hypobaric hypoxic preconditioning (HH-PC) control group, and normobaric control group. All groups were subjected to SCI by weight drop device. Rats from each group were examined for neurological behavior and electrophysiological function. Tissue sections were analyzed by using immunohistochemistry, TdT-mediated dUTP-biotin nick end labeling, and axonal tract tracing. Significant neurological deficits were observed after SCI and HBO-PC and HH-PC improved neurological deficits 1 week post-injury. The latencies of motor-evoked potential and somatosensory-evoked potential were significantly delayed after SCI, which was attenuated by HBO-PC and HH-PC. Compared with normobaric control group, pretreatment with HBO and hypobaric hypoxia significantly reduced the number of TdT-mediated dUTP-biotin nick end labeling-positive cells, and increased nestin-positive cells. HBO-PC and HH-PC enhanced axonal growth after SCI. In conclusion, preconditioning with HBO and hypobaric hypoxia can facilitate functional recovery and suppress cell apoptosis after SCI and may prove to be a useful preventive strategy to neurosurgical SCI.

Measurement of gamma-aminobutyric acid in human cerebrospinal fluid: radioreceptor assay using [3H]muscimol

International Nuclear Information System (INIS)

Baraczka, K.; Sperk, G.

1981-01-01

A method is described for the determination of gamma-aminobutyric acid (GABA) levels in human cerebrospinal fluid by modification of the radioreceptor assay utilizing [ 3 H]muscimol as labelled ligand. This method is compared with the radioreceptor assay using [ 3 H]GABA as labelled ligand. Although the [ 3 H]muscimol assay is less sensitive than the [ 3 H]GABA method, it offers the advantage of being more rapid due to the use of a filtration step instead of the usual, more time-consuming centrifugation of the samples. Samples of CSF of patients with various neurological or psychiatric disturbances were analysed. There was a satisfactory correlation between the GABA values obtained by the two assays. (Auth.)

A Label Correcting Algorithm for Partial Disassembly Sequences in the Production Planning for End-of-Life Products

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Pei-Fang (Jennifer Tsai

2012-01-01

Full Text Available Remanufacturing of used products has become a strategic issue for cost-sensitive businesses. Due to the nature of uncertain supply of end-of-life (EoL products, the reverse logistic can only be sustainable with a dynamic production planning for disassembly process. This research investigates the sequencing of disassembly operations as a single-period partial disassembly optimization (SPPDO problem to minimize total disassembly cost. AND/OR graph representation is used to include all disassembly sequences of a returned product. A label correcting algorithm is proposed to find an optimal partial disassembly plan if a specific reusable subpart is retrieved from the original return. Then, a heuristic procedure that utilizes this polynomial-time algorithm is presented to solve the SPPDO problem. Numerical examples are used to demonstrate the effectiveness of this solution procedure.

A comparison of labelled antibody methods for the detection of virus antigens in cell monolayers

International Nuclear Information System (INIS)

Oram, J.D.; Crooks, A.J.

1979-01-01

A number of labelled antibody methods have been applied to the detection of Semliki Forest virus antigens after replication of the virus in monolayers of host cells in multi-well polystyrene plates. The importance of several reaction variables has been investigated and the sensitivity of the methods compared for different periods of virus replication. Direct assays with radio-labelled antibody (RLA) and indirect assays peroxidase-antiperoxidase complexes (PAP) were equally sensitive. Direct and indirect assays using enzyme-linked antibodies (ELA) were slightly less sensitive than the direct RLA and PAP methods but were more sensitive than the indirect RLA or fluorescent antibody (FLA) methods. Direct assays using ELA were more rapid and easier to perform than the other assay methods. (Auth.)

Effect of ionizing radiation on apoptosis in the cortex of mouse lymph node

International Nuclear Information System (INIS)

Chen Dong; Liu Jiamei; Liu Shuzheng

1999-01-01

Objective: To study the alteration of apoptosis in the cortex of mouse lymph node following whole body X-irradiation. Methods: The method of TdT-mediated dUTP nick end labelling (TUNEL) was used to detect apoptosis the cortex of mouse lymph node. Results: The sensitivity to high and low dose ionizing radiation was distinct in different area of the cortex. Conclusion: The decrease of apoptotic cells in the inter nodular and deep cortex indicate that low dose radiation may suppress the apoptosis of T lymphocytes and play a role in immune regulation

Labelling and quality control of 99mTc labelled somatostatin analogues

International Nuclear Information System (INIS)

Poramatikul, N.; Sangsuriyan, J.; Kongpeth, P.; Ngamprayad, T.; Laloknam, S.; Permtermsin, C.; Madsomboon, N.

2001-01-01

To standardize interlaboratory reproducibility, iodination of RC-160 with 125 I and direct labelling of RC-160 with 99m Tc, quality control and binding assay were performed. Two conjugated peptides, HYNIC-RC-160 and MAG-3-RC-160, were synthesized. The conjugated peptides were radiolabelled with 99m Tc via co-ligands; 99m Tc-MAG-3-RC-160 via glucoheptonate, 99m Tc-HYNIC-RC-160 via EDDA and tricine. Conditions for labelling were optimized. Analytical and purification methods for the labelled products were developed. Radiochemical purity test of 99m Tc labelled peptides was performed by HPLC with gradient elution of 0.1%TFA/water and acetonitrile, or by ITLC-SG in saline and in 50% acetonitrile. The contaminants in 99m Tc radiolabelled product were separated by elution from SEPPAK C-18 cartridge by 0.1% acetic acid and the pure product was eluted out of SEPPAK column by 50% acetonitrile with about 68% recovery. Stability of the purified 99m Tc-MAG3-RC-160 stored at -20 deg. C was more than 72 h. 99m Tc-MAG-3-RC-160 showed a high equilibrium dissociation constant with K D of 26 pmole/mg protein and B max of 7.9 mM. (author)

DRABAL: novel method to mine large high-throughput screening assays using Bayesian active learning

KAUST Repository

Soufan, Othman

2016-11-10

Background Mining high-throughput screening (HTS) assays is key for enhancing decisions in the area of drug repositioning and drug discovery. However, many challenges are encountered in the process of developing suitable and accurate methods for extracting useful information from these assays. Virtual screening and a wide variety of databases, methods and solutions proposed to-date, did not completely overcome these challenges. This study is based on a multi-label classification (MLC) technique for modeling correlations between several HTS assays, meaning that a single prediction represents a subset of assigned correlated labels instead of one label. Thus, the devised method provides an increased probability for more accurate predictions of compounds that were not tested in particular assays. Results Here we present DRABAL, a novel MLC solution that incorporates structure learning of a Bayesian network as a step to model dependency between the HTS assays. In this study, DRABAL was used to process more than 1.4 million interactions of over 400,000 compounds and analyze the existing relationships between five large HTS assays from the PubChem BioAssay Database. Compared to different MLC methods, DRABAL significantly improves the F1Score by about 22%, on average. We further illustrated usefulness and utility of DRABAL through screening FDA approved drugs and reported ones that have a high probability to interact with several targets, thus enabling drug-multi-target repositioning. Specifically DRABAL suggests the Thiabendazole drug as a common activator of the NCP1 and Rab-9A proteins, both of which are designed to identify treatment modalities for the Niemann–Pick type C disease. Conclusion We developed a novel MLC solution based on a Bayesian active learning framework to overcome the challenge of lacking fully labeled training data and exploit actual dependencies between the HTS assays. The solution is motivated by the need to model dependencies between existing

Similar to spironolactone, oxymatrine is protective in aldosterone-induced cardiomyocyte injury via inhibition of calpain and apoptosis-inducing factor signaling.

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Ting-Ting Xiao

Full Text Available Accumulating evidence indicates that oxymatrine (OMT possesses variously pharmacological properties, especially on the cardiovascular system. We previously demonstrated that activated calpain/apoptosis-inducing factor (AIF-mediated pathway was the key molecular mechanism in aldosterone (ALD induces cardiomyocytes apoptosis. In the present study, we extended the experimentation by investigating the effect of OMT on cardiomyocytes exposed to ALD, as compared to spironolactone (Spiro, a classical ALD receptor antagonist. Cardiomyocytes were pre-incubated with OMT, Spiro or vehicle for 1 h, and then, cardiomyocytes were exposed to ALD 24 h. The cell injury was evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay and lactate dehydrogenase (LDH leakage ratio. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL assay, annexin V/PI staining, and relative caspase-3 activity assay. Furthermore, expression of pro-apoptotic proteins including truncated Bid (tBid, calpain and AIF were evaluated by western blot analysis. ALD stimulation increased cardiomyocytes apoptosis, caspase-3 activity and protein expression of calpain, tBid and AIF in the cytosol (p<0.05. Pre-incubated with cardiomyocytes injury and increased caspase-3 activity were significantly attenuated (p<0.05. Furthermore, OMT suppressed ALD-induced high expression of calpain and AIF. And these effects of OMT could be comparable to Spiro. These findings indicated that OMT might be a potential cardioprotective-agent against excessive ALD-induced cardiotoxicity, at least in part, mediated through inhibition of calpain/AIF signaling.

Effects of Urtica dioica dichloromethane extract on cell apoptosis and related gene expression in human breast cancer cell line (MDA-MB-468).

Science.gov (United States)

Mohammadi, A; Mansoori, B; Goldar, S; Shanehbandi, D; Khaze, V; Mohammadnejad, L; Baghbani, E; Baradaran, B

2016-02-29

Breast cancer is the most common cancer among women in worldwide, especially in developing countries. Therefore, a large number of anticancer agents with herbal origins have been reported against this deadly disease. This study is the first to examine the cytotoxic and apoptotic effects of Urtica dioica in MDA-MB-468, human breast adenocarcinoma cells. The 3-(4,5-dimethylethiazol-2 yl)-2,5- diphenyltetrazolium (MTT) reduction and trypan-blue exclusion assay were performed in MDA-MB-468 cells as well as control cell line L929 to analyze the cytotoxic activity of the dichloromethane extract. In addition, Apoptosis induction of Urtica dioica on the MDA-MB-468 cells was assessed using TUNEL (terminal deoxy transferase (TdT)-mediated dUTP nick- end labeling) assay and DNA fragmentation analysis and real-time polymerase chain reaction (PCR). The results showed that the extract significantly inhibited cell growth and viability without inducing damage to normal control cells. Nuclei Staining in TUNEL and DNA fragments in DNA fragmentation assay and increase in the mRNA expression levels of caspase-3, caspase-9, decrease in the bcl2 and no significant change in the caspase-8 mRNA expression level, showed that the induction of apoptosis was the main mechanism of cell death that induce by Urtica dioica extract. Our results suggest that urtica dioica dichloromethane extract may contain potential bioactive compound(s) for the treatment of breast adenocarcinoma.

Tamaractam, a New Bioactive Lactam from Tamarix ramosissima, Induces Apoptosis in Rheumatoid Arthritis Fibroblast-Like Synoviocytes.

Science.gov (United States)

Yao, Yao; Jiang, Cheng-Shuai; Sun, Na; Li, Wei-Qi; Niu, Yang; Han, Huai-Qin; Miao, Zhen-Hua; Zhao, Xun-Xia; Zhao, Jing; Li, Juan

2017-01-10

Chemical investigation of Tamarix ramosissima Ledeb, a traditional herbal medicine used for rheumatoid arthritis (RA) treatment in northwest China, led to the discovery of a new phenolic aromatic rings substituted lactam, tamaractam ( 1 ), together with the previously reported compounds cis - N -feruloyl-3- O -methyldopamine ( 2 ) and trans - N -feruloyl-3- O -methyldopamine ( 3 ). The structures of the compounds were determined by high resolution electrospray ionization mass spectroscopy (HRESIMS) and 1D and 2D-NMR experiments, as well as comparison with the literature data. The effects of the three compounds on the viability of RA fibroblast-like synoviocytes (RA-FLS) were assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2- H -tetrazolium bromide (MTT) assay. Pro-apoptosis effect of compound 1 in RA-FLS was further investigated by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay, activated caspase-3/7 level assessment using luminescence assay, and sub-G₁ fraction measurement using flow cytometry. It was found that these three compounds displayed variable proliferation inhibitory activity in RA-FLS, and compound 1 exhibited the strongest effect. Compound 1 could remarkably induce cellular apoptosis of RA-FLS, increase activated caspase-3/7 levels, and significantly increase sub-G₁ fraction in the cell cycle. The results suggested that compound 1 may inhibit the proliferation of RA-FLS through apoptosis-inducing effect, and these compounds may contribute to the anti-RA effect of T. ramosissima .

Tamaractam, a New Bioactive Lactam from Tamarix ramosissima, Induces Apoptosis in Rheumatoid Arthritis Fibroblast-Like Synoviocytes

Directory of Open Access Journals (Sweden)

Yao Yao

2017-01-01

Full Text Available Chemical investigation of Tamarix ramosissima Ledeb, a traditional herbal medicine used for rheumatoid arthritis (RA treatment in northwest China, led to the discovery of a new phenolic aromatic rings substituted lactam, tamaractam (1, together with the previously reported compounds cis-N-feruloyl-3-O-methyldopamine (2 and trans-N-feruloyl-3-O-methyldopamine (3. The structures of the compounds were determined by high resolution electrospray ionization mass spectroscopy (HRESIMS and 1D and 2D-NMR experiments, as well as comparison with the literature data. The effects of the three compounds on the viability of RA fibroblast-like synoviocytes (RA-FLS were assessed by 3-(4,5-dimethyl-2-thiazolyl-2,5-diphenyl-2-H-tetrazolium bromide (MTT assay. Pro-apoptosis effect of compound 1 in RA-FLS was further investigated by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL assay, activated caspase-3/7 level assessment using luminescence assay, and sub-G1 fraction measurement using flow cytometry. It was found that these three compounds displayed variable proliferation inhibitory activity in RA-FLS, and compound 1 exhibited the strongest effect. Compound 1 could remarkably induce cellular apoptosis of RA-FLS, increase activated caspase-3/7 levels, and significantly increase sub-G1 fraction in the cell cycle. The results suggested that compound 1 may inhibit the proliferation of RA-FLS through apoptosis-inducing effect, and these compounds may contribute to the anti-RA effect of T. ramosissima.

Anti-tumor effect of cisplatin in human oral squamous cell carcinoma was enhanced by andrographolide via upregulation of phospho-p53 in vitro and in vivo.

Science.gov (United States)

Chen, Songjie; Hu, Hui; Miao, Shushu; Zheng, Jiayong; Xie, Zhijian; Zhao, Hui

2017-05-01

Oral squamous cell carcinoma is one of the most common neoplasm in the world. Despite the improvements in diagnosis and treatment, the outcome is still poor now. Thus, the development of novel therapeuticapproaches is needed. The aim of this study is to assess the synergistic anti-tumor effect of andrographolide with cisplatin (DDP) in oral squamous cell carcinoma CAL-27 cells in vitro and in vivo. We performed Cell Counting Kit-8 proliferation assay, apoptosis assay, and western blotting on CAL-27 cells treated with andrographolide, DDP or the combination in vitro. In vivo, we also treated CAL-27 xenografts with andrographolide or the combination, and performed terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assay and immunohistochemical analysis of Ki-67. The results showed the combination of andrographolide and DDP synergistically inhibited CAL-27 cell proliferation in vitro and caused tumor regression in vivo in the CAL-27 xenografts. In addition, the synergistic anti-tumor effect of andrographolide with synergistic was due to an enhanced apoptosis. Moreover, the combination therapy upregulated the expression level of p-p53 in vitro and decreased Ki-67 expression in vivo. Our data indicate that the combination treatment of andrographolide and DDP results in synergistic anti-tumor growth activity against oral squamous cell carcinoma CAL-27 in vitro and in vivo. These results demonstrated that combination of andrographolide with DDP was likely to represent a potential therapeutic strategy for oral squamous cell carcinoma.

A novel flow cytometric assay for measurement of In Vivo pulmonary neutrophil phagocytosis

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Gentry-Nielsen Martha J

2006-07-01

Full Text Available Abstract Background Phagocytosis assays are traditionally performed in vitro using polymorphonuclear leukocytes (PMNs isolated from peripheral blood or the peritoneum and heat-killed, pre-opsonized organisms. These assays may not adequately mimic the environment within the infected lung. Our laboratory therefore has developed a flow cytometric in vivo phagocytosis assay that enables quantification of PMN phagocytosis of viable bacteria within the lungs of rats. In these studies, rats are injected transtracheally with lipopolysaccharide (LPS to recruit PMNs to their lungs. They are then infected with live 5(-and 6 carboxyfluorescein diacetate succinimidyl ester (CFDA/SE labeled type 3 Streptococcus pneumoniae. Bronchoalveolar lavage is performed and resident alveolar macrophages and recruited PMNs are labeled with monoclonal antibodies specific for surface epitopes on each cell type. Three color flow cytometry is utilized to identify the cell types, quantify recruitment, and determine uptake of the labeled bacteria. Results The viability of the alveolar macrophages and PMNs isolated from the lavage fluid was >95%. The values of the percentage of PMNs in the lavage fluid as well as the percentage of PMNs associated with CFSE-labeled S. pneumoniae as measured through flow cytometry showed a high degree of correlation with the results from manual counting of cytospin slides. Conclusion This assay is suitable for measuring bacterial uptake within the infected lung. It can be adapted for use with other organisms and/or animal model systems.

A simplified radioimmunoassay for triiodothyronine (T3) using pre-incubated labelled antigen and antibody

International Nuclear Information System (INIS)

Pillai, M.R.A.; Nagvekar, U.H.; Desai, C.N.; Mani, R.S.

1986-01-01

The development of a simplified radioimmunoassay for triiodothyronine (T 3 ) using pre-incubated labelled T 3 and antibody is described. The assay is carried out by adding 50 μl of standard or sample to 0.4 ml of pre-incubated reagent dispensed in assay tubes. The reaction was allowed to proceed for about four hours and the antigen-antibody complex precipitated by the addition of 1 cm 3 of 22% polyethylene glycol solution. Due to the high dissociation constant of T 3 -antibody complex at 37 deg C, the labelled antigen-antibody complex dissociates and thereby the unlabelled antigen binds with the antibody. The sensitivity of this assay is comparable to an assay done by the equilibrium method using the same antibody. Sixty serum samples were analyzed using this method and were compared with the equilibrium assay. (author)

A highly sensitive and specific assay for vertebrate collagenase

International Nuclear Information System (INIS)

Sodek, J.; Hurum, S.; Feng, J.

1981-01-01

A highly sensitive and specific assay for vertebrate collagenase has been developed using a [ 14 C]-labeled collagen substrate and a combination of SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and fluorography to identify and quantitate the digestion products. The assay was sufficiently sensitive to permit the detection and quantitation of collagenase activity in 0.1 μl of gingival sulcal fluid, and in samples of cell culture medium without prior concentration. The assay has also been used to detect the presence of inhibitors of collagenolytic enzymes in various cell culture fluids. (author)

Solid-phase immunoradiometric assay for C-reactive protein using magnetisable cellulose particles

International Nuclear Information System (INIS)

Beer, F.C. de; Pepys, M.B.

1982-01-01

An immunoradiometric assay (IRMA) for C-reactive protein (CRP) was developed using magnetisable cellulose particles as the solid-phase support for anti-CRP antibodies. 125 I-labelled immunopurified anti-CRP antibody was used to quantitate the amount of CRP taken up by the solid phase. Unbound label was easily and rapidly removed by decantation after sedimenting the particles on a magnet. The assay could detect 1 μg CRP/l and had a range of up to 10 mg/l with the portion of the standard curve between 10 μg/l and 2-3 mg/l being linear. Fifty samples per hour could be processed manually from serum to CRP result with an intra-assay CV of 5.2% and an inter-assay CV of 10.0%, based on 5 replicates of 5 samples with CRP levels between 2 mg/l and 180 mg/l run in 5 separate assays. Fifty clinical samples were assayed in parallel with a standard electroimmunoassay and yielded a linear correlation coefficient (r) of 0.975 and a slope of 0.98. With its single, brief incubation step including all reagents and its simple phase separation procedure the present method may be the assay of choice when precise measurement of CRP concentrations is required rapidly. (Auth.)

Radiorespirometic assay device

International Nuclear Information System (INIS)

Levin, G.V.; Straat, P.A.

1981-01-01

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.)

A Broad G Protein-Coupled Receptor Internalization Assay that Combines SNAP-Tag Labeling, Diffusion-Enhanced Resonance Energy Transfer, and a Highly Emissive Terbium Cryptate.

Science.gov (United States)

Levoye, Angélique; Zwier, Jurriaan M; Jaracz-Ros, Agnieszka; Klipfel, Laurence; Cottet, Martin; Maurel, Damien; Bdioui, Sara; Balabanian, Karl; Prézeau, Laurent; Trinquet, Eric; Durroux, Thierry; Bachelerie, Françoise

2015-01-01

Although G protein-coupled receptor (GPCR) internalization has long been considered as a major aspect of the desensitization process that tunes ligand responsiveness, internalization is also involved in receptor resensitization and signaling, as well as the ligand scavenging function of some atypical receptors. Internalization thus contributes to the diversity of GPCR-dependent signaling, and its dynamics and quantification in living cells has generated considerable interest. We developed a robust and sensitive assay to follow and quantify ligand-induced and constitutive-induced GPCR internalization but also receptor recycling in living cells. This assay is based on diffusion-enhanced resonance energy transfer (DERET) between cell surface GPCRs labeled with a luminescent terbium cryptate donor and a fluorescein acceptor present in the culture medium. GPCR internalization results in a quantifiable reduction of energy transfer. This method yields a high signal-to-noise ratio due to time-resolved measurements. For various GPCRs belonging to different classes, we demonstrated that constitutive and ligand-induced internalization could be monitored as a function of time and ligand concentration, thus allowing accurate quantitative determination of kinetics of receptor internalization but also half-maximal effective or inhibitory concentrations of compounds. In addition to its selectivity and sensitivity, we provided evidence that DERET-based internalization assay is particularly suitable for characterizing biased ligands. Furthermore, the determination of a Z'-factor value of 0.45 indicates the quality and suitability of DERET-based internalization assay for high-throughput screening (HTS) of compounds that may modulate GPCRs internalization.

Heated oligonucleotide ligation assay (HOLA): an affordable single nucleotide polymorphism assay.

Science.gov (United States)

Black, W C; Gorrochotegui-Escalante, N; Duteau, N M

2006-03-01

Most single nucleotide polymorphism (SNP) detection requires expensive equipment and reagents. The oligonucleotide ligation assay (OLA) is an inexpensive SNP assay that detects ligation between a biotinylated "allele-specific detector" and a 3' fluorescein-labeled "reporter" oligonucleotide. No ligation occurs unless the 3' detector nucleotide is complementary to the SNP nucleotide. The original OLA used chemical denaturation and neutralization. Heated OLA (HOLA) instead uses a thermal stable ligase and cycles of denaturing and hybridization for ligation and SNP detection. The cost per genotype is approximately US$1.25 with two-allele SNPs or approximately US$1.75 with three-allele SNPs. We illustrate the development of HOLA for SNP detection in the Early Trypsin and Abundant Trypsin loci in the mosquito Aedes aegypti (L.) and at the a-glycerophosphate dehydrogenase locus in the mosquito Anopheles gambiae s.s.

W. Horsley Gantt, Nick, and the Pavlovian Science at Phipps Clinic.

Science.gov (United States)

Ruiz, Gabriel; Sánchez, Natividad

2016-10-24

William Horsley Gantt is well known as one to the principal proponents of Pavlovian methodology in the U.S. After a long stay at Ivan Petrovich Pavlov's laboratory in Leningrad from 1925 to 1929, Gantt was invited by Adolf Meyer to join the Henry Phipps Psychiatric Clinic, where he founded and directed the Pavlovian Laboratory from 1930 to 1964. Soon after his arrival at Phipps Clinic in 1931, Gantt began a Pavlovian research program that included the investigation of nervous disturbances in dogs and clinical researches with psychiatric patients. In these studies, Gantt combined a physiological method (the conditional reflexes approach), with a psychiatric problem (nervous disorders) in the context of Meyer's psychobiology that established the person or individual as unit of analysis. This fact, concentrating upon a single individual, made Gantt studies with dogs recognizable and interesting to physicians, psychologists, and psychiatrists who also worked on individuals. In this paper, we use archival materials -including correspondence, notebooks, and unpublished autobiographical material- to present a case study, that of William Horsley Gantt and his dog Nick. We will explore the reasons why Gantt' studies on nervous disturbances with this dog captured the interest of psychiatrists and clinical psychologists.

Establishment of immunoradiometric assay for free prostate-specific antigen

International Nuclear Information System (INIS)

Ma Lianxue

2009-01-01

An immunoradiometric assay (IRMA) of free prostate specific antigen (F-PSA) in serum was established. One monoclonal antibody against total PSA (T-PSA) was coated on the plastic tubes, the other against F-PSA was labeled with 125 I. The sensitivity of assay was 0.04 μg/L (n=20, +2s), the CVs were 2.9%-4.0% for the intra-assay and 3.5%-10.5% for the inter-assay and the average recovery was 102.7%. The correlative equation comparing with the FPSA-RIA (CIS BIO) is y=0.965 1 χ -0.001 1, and r=0.996 4. This F-PSA IRMA is a sensitive and precise method in detecting F-PSA and fit for the vitro assay. (authors)

A double-labeling assay for simultaneous estimation and characterization of estrogen and progesterone receptors using radioiodinated estradiol and tritiaded Org 2058

International Nuclear Information System (INIS)

Ronchi, E.; Granata, G.; Brivio, M.

1986-01-01

Estrogen (ER) and progesterone receptors (PgR) appear to be a perequisite to elicit a biologic response by a hormone-target organ. Current methodologies for analysis of these proteins (e.g:dextran-coated charcoal, DCC) in single-label assay (SLA) require relatively large amounts of tissue material, time and laboriousness. Therefore, the authors have developed for breast cancer tissue an improved dual-label assay (DLA) for simultaneous titration (by DCC) and/or characterization (by sedimentation properties) of ER and PgR on the same sample, using *H1*H2*H5I-E*L2 and *H3H-Org 2058 as tracers. The interaction of *H1*H2*H5I-E*L2 with ER and plasma proteins in comparison to *H3H-E*L2 was studied in terms of specificity, time course, affinity binding and sedimentation pattern. *H1*H2*H5I-E*L2 bound the same molecular forms displayed by *H3H-E*L2 (9 and 3S) but with lower titers (about 1.3-fold), irrespective of the technique used, and did not bind to sex hormone-binding globulin. Simultaneous detection of *H1*H2*H5I and *H3H was achieved by use of a gamma counter plus a beta counter sequentially. ER and PgR titrations with DCC in DLA were in good agreement with those obtained with SLA, in terms of titers and Ka values. An analogous results was obtained with sucrose density gradient (SDG) analysis. Both the DLA methods were highly reproducible (CV<8.0%). Between the rotors available for SDG, the vertical one was preferable because of the larger number of samples processed and of less purturbation of sedimenting receptor molecules. Furthermore, a biochemical applications of the method is described. In conclusion, the DLA procedure, by simplifying ER and PgR estimation, makes it possible to study, even on small tumor biopsies, the molecular properties of these proteins in relation to the clinical response of the disease

Rapid Active Assay for the Detection of Antibodies to West Nile Virus in Chickens

National Research Council Canada - National Science Library

Groves, Stephanie S; Turell, Michael J; Bailey, Charles L; Morozov, Victor N

2008-01-01

... by detection of bound IgM molecules with functionalized magnetic beads as active labels. This assay takes only 15 minutes and has the same sensitivity as a commercially available human WNV IgM antibody-capture enzyme-linked immunosorbent assay...

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.

Effect of green light spectra on the reduction of retinal damage and stress in goldfish, Carassius auratus

International Nuclear Information System (INIS)

Song, Jin Ah; Kim, Na Na; Choi, Young Jae; Choi, Cheol Young

2016-01-01

We investigated the effect of light spectra on retinal damage and stress in goldfish using green (530 nm) and red (620 nm) light emitting diodes (LEDs) at three intensities each (0.5, 1.0, and 1.5 W/m"2). We measured the change in the levels of plasma cortisol and H_2O_2 and expression and levels of caspase-3. The apoptotic response of green and red LED spectra was assessed using the terminal transferase dUTP nick end labeling (TUNEL) assay. Stress indicator (cortisol and H_2O_2) and apoptosis-related genes (caspase-3) decreased in green light, but increased in red light with higher light intensities over time. The TUNEL assay revealed that more apoptotic cells were detected in outer nuclear layers after exposure to red LED over time with the increase in light intensity, than the other spectra. These results indicate that green light efficiently reduces retinal damage and stress, whereas red light induces it. Therefore, red light-induced retina damage may induce apoptosis in goldfish retina. -- Highlights: •Green light efficiently reduces retinal damage and stress. •Green spectra reduce caspase production and apoptosis. •Red light-induced retina damage may induce apoptosis in goldfish retina. •The retina of goldfish recognizes green spectra as a stable environment.

Protective Effects of Kaempferol against Myocardial Ischemia/Reperfusion Injury in Isolated Rat Heart via Antioxidant Activity and Inhibition of Glycogen Synthase Kinase-3β

Science.gov (United States)

Zhou, Mingjie; Ren, Huanhuan; Wang, Wenjuan; Zheng, Qiusheng; Wang, Dong

2015-01-01

Objective. This study aimed to evaluate the protective effect of kaempferol against myocardial ischemia/reperfusion (I/R) injury in rats. Method. Left ventricular developed pressure (LVDP) and its maximum up/down rate (±dp/dt max) were recorded as myocardial function. Infarct size was detected with 2,3,5-triphenyltetrazolium chloride staining. Cardiomyocyte apoptosis was determined using terminal deoxynucleotidyl nick-end labeling (TUNEL). The levels of creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione/glutathione disulfide (GSH/GSSG) ratio, and tumor necrosis factor-alpha (TNF-α) were determined using enzyme linked immunosorbent assay (ELISA). Moreover, total glycogen synthase kinase-3β (GSK-3β), phospho-GSK-3β (P-GSK-3β), precaspase-3, cleaved caspase-3, and cytoplasm cytochrome C were assayed using Western blot analysis. Results. Pretreatment with kaempferol significantly improved the recovery of LVDP and ±dp/dt max, as well as increased the levels of SOD and P-GSK-3β and GSH/GSSG ratio. However, the pretreatment reduced myocardial infarct size and TUNEL-positive cell rate, as well as decreased the levels of cleaved caspase-3, cytoplasm cytochrome C, CK, LDH, MDA, and TNF-α. Conclusion. These results suggested that kaempferol provides cardioprotection via antioxidant activity and inhibition of GSK-3β activity in rats with I/R. PMID:26265983

Suppression of heat shock protein 70 by siRNA enhances the antitumor effects of cisplatin in cultured human osteosarcoma cells.

Science.gov (United States)

Mori, Yuki; Terauchi, Ryu; Shirai, Toshiharu; Tsuchida, Shinji; Mizoshiri, Naoki; Arai, Yuji; Kishida, Tsunao; Fujiwara, Hiroyoshi; Mazda, Osam; Kubo, Toshikazu

2017-09-01

Although advances in chemotherapy have improved the prognosis for osteosarcoma, some patients do not respond sufficiently to treatment. Heat shock protein 70 (Hsp70) is expressed at high levels in cancer cells and attenuates the therapeutic efficacy of anticancer agents, resulting in a poorer prognosis. This study investigated whether small interfering RNA (siRNA)-mediated inhibition of Hsp70 expression in an osteosarcoma cell line would enhance sensitivity to cisplatin. The expression of Hsp70 with cisplatin treatment was observed by using Western blotting and real-time reverse transcription polymerase chain reaction (RT-PCR). Changes in the IC 50 of cisplatin when Hsp70 was inhibited by siRNA were evaluated. Cisplatin's effectiveness in inducing apoptosis was assessed by assay of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), caspase-3 activity, and mitochondrial membrane potential. Up-regulation of Hsp70 expression was dependent on the concentration of cisplatin. Inhibition of Hsp70 expression significantly reduced the IC 50 of cisplatin. When cisplatin was added to osteosarcoma cells with Hsp70 expression inhibited, a significant increase in apoptosis was demonstrated in TUNEL, caspase-3, and mitochondrial membrane potential assays. Inhibition of Hsp70 expression induced apoptosis in cultured osteosarcoma cells, indicating that Hsp70 inhibition enhanced sensitivity to cisplatin. Inhibition of Hsp70 expression may provide a new adjuvant therapy for osteosarcoma.

Fisetin and polymeric micelles encapsulating fisetin exhibit potent cytotoxic effects towards ovarian cancer cells.

Science.gov (United States)

Xiao, Xue; Zou, Juan; Fang, Yin; Meng, Yibo; Xiao, Chao; Fu, Jiaxin; Liu, Shiyu; Bai, Peng; Yao, Yuan

2018-03-15

The anti-tumor activities of Natural compounds and their derivatives are of great interest to pharmaceutical industries. Fisetin is one of prospective natural compounds in this regard but unfortunately with poor hydrophilicity. The effects of unmodified and modified fisetin in cultured ovarian cancer cells were compared by transmission electronmicroscopy to determine apoptotic bodies, MTT assay to quantitate cell numbers, and fluorescence activated cell sorting analyse of various markers to determine the apoptotic state. In addition, the efficacy of fisetin and fisetin-micelles in vivo was determined by using immunocompromised mice. Apoptosis was measured by established markers using both western blot analysis and immunochemistry. Angiogenesis in a xenograft mouse model carring SKOV3 cells was evaluated by color Doppler ultrasound and immunohistochemistry. Multiple lines of evidence indicated that fisetin and fisetin micelles induce apoptosis in ovarian cancer cells in a dose-dependent manner. Histological analysis, terminal deoxynucleotidyltransferase-mediated nick-end labeling assay, western blot, immunohistochemical detection and microvessel density detection demonstrated that fisetin and fisetin micelles induced increased tumor apoptosis, proliferation suppression and antiangiogenesis activities. As far as we know, the present study is the first time to demonstrate the potency of both fisetin and fisetin micelles inducing apoptosis in ovarian cancer cells. Further studies will be needed to validate the therapeutic potential of fisetin and fisetin micelles in ovarian cancer treatment.

Evaluation of the relative biological effectiveness of carbon ion beams in the cerebellum using the rat organotypic slice culture system

International Nuclear Information System (INIS)

Yoshida, Yukari; Katoh, Hiroyuki; Nakano, Takashi; Suzuki, Yoshiyuki; Al-Jahdari, Wael S.; Shirai, Katsuyuki; Hamada, Nobuyuki; Funayama, Tomoo; Sakashita, Tetsuya; Kobayashi, Yasuhiko

2012-01-01

The purpose of this study was to clarify the relative biological effectiveness (RBE) values of carbon ion (C) beams in normal brain tissues, a rat organotypic slice culture system was used. The cerebellum was dissected from 10-day-old Wistar rats, cut parasagittally into approximately 600-μm-thick slices and cultivated using a membrane-based culture system with a liquid-air interface. Slices were irradiated with 140 kV X-rays and 18.3 MeV/amu C-beams (linear energy transfer=108 keV/μm). After irradiation, the slices were evaluated histopathologically using hematoxylin and eosin staining, and apoptosis was quantified using the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay. Disorganization of the external granule cell layer (EGL) and apoptosis of the external granule cells (EGCs) were induced within 24 h after exposure to doses of more than 5 Gy from C-beams and X-rays. In the early postnatal cerebellum, morphological changes following exposure to C-beams were similar to those following exposure to X-rays. The RBEs values of C-beams using the EGL disorganization and the EGC TUNEL index endpoints ranged from 1.4 to 1.5. This system represents a useful model for assaying the biological effects of radiation on the brain, especially physiological and time-dependent phenomena. (author)

Inhibitory effects of CP on the growth of human gastric adenocarcinoma BGC-823 tumours in nude mice.

Science.gov (United States)

Wang, Hai-Jun; Liu, Yu; Zhou, Bao-Jun; Zhang, Zhan-Xue; Li, Ai-Ying; An, Ran; Yue, Bin; Fan, Li-Qiao; Li, Yong

2018-05-01

Objective To investigate the potential antitumour effects of [2-(6-amino-purine-9-yl)-1-hydroxy-phosphine acyl ethyl] phosphonic acid (CP) against gastric adenocarcinoma. Methods Human BGC-823 xenotransplants were established in nude mice. Animals were randomly divided into control and CP groups, which were administered NaHCO 3 vehicle alone or CP dissolved in NaHCO 3 (200 µg/kg body weight) daily, respectively. Tumour volume was measured weekly for 6 weeks. Resected tumours were assayed for proliferative activity with anti-Ki-67 or anti-proliferating cell nuclear antigen (PCNA) antibodies. Cell apoptosis was examined using terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assays and with caspase-3 immunostaining. Proteins were measured by Western blotting. Results There was a significant reduction in tumour volume and a reduced percentage of Ki-67-positive or PCNA-positive cells in the CP group compared with the control group. The percentage of TUNEL-positive or caspase 3-positive cells significantly increased following CP treatment compared with the control group. Tumours from the CP group had higher levels of phosphorylated-extracellular signal-regulated kinase (p-ERK) and phosphorylated-AKT (p-AKT) compared with control tumours. Conclusion CP treatment inhibited tumour growth and induced tumour cell apoptosis in a nude mouse model of BGC-823 gastric adenocarcinoma. Activation of the AKT and ERK signalling pathways may mediate this antitumour activity.

Effect of green light spectra on the reduction of retinal damage and stress in goldfish, Carassius auratus

Energy Technology Data Exchange (ETDEWEB)

Song, Jin Ah; Kim, Na Na; Choi, Young Jae; Choi, Cheol Young, E-mail: choic@kmou.ac.kr

2016-07-22

We investigated the effect of light spectra on retinal damage and stress in goldfish using green (530 nm) and red (620 nm) light emitting diodes (LEDs) at three intensities each (0.5, 1.0, and 1.5 W/m{sup 2}). We measured the change in the levels of plasma cortisol and H{sub 2}O{sub 2} and expression and levels of caspase-3. The apoptotic response of green and red LED spectra was assessed using the terminal transferase dUTP nick end labeling (TUNEL) assay. Stress indicator (cortisol and H{sub 2}O{sub 2}) and apoptosis-related genes (caspase-3) decreased in green light, but increased in red light with higher light intensities over time. The TUNEL assay revealed that more apoptotic cells were detected in outer nuclear layers after exposure to red LED over time with the increase in light intensity, than the other spectra. These results indicate that green light efficiently reduces retinal damage and stress, whereas red light induces it. Therefore, red light-induced retina damage may induce apoptosis in goldfish retina. -- Highlights: •Green light efficiently reduces retinal damage and stress. •Green spectra reduce caspase production and apoptosis. •Red light-induced retina damage may induce apoptosis in goldfish retina. •The retina of goldfish recognizes green spectra as a stable environment.

Caspase-3-dependent apoptosis of citreamicin ε-induced heLa iells Is associated with reactive oxygen species generation

KAUST Repository

Liu, Lingli

2013-07-15

Citreamicins, members of the polycyclic xanthone family, are promising antitumor agents that are produced by Streptomyces species. Two diastereomers, citreamicin ε A (1) and B (2), were isolated from a marine-derived Streptomyces species. The relative configurations of these two diastereomers were determined using NMR spectroscopy and successful crystallization of citreamicin ε A (1). Both diastereomers showed potent cytotoxic activity against HeLa (cervical cancer) and HepG2 (hepatic carcinoma) cells with IC 50 values ranging from 30 to 100 nM. The terminal deoxynucleotidyl transferase dUTP nick-end labeling assay confirmed that citreamicin ε A (1) induced cellular apoptosis, and Western blot analysis showed that apoptosis occurred via activation of caspase-3. The 2,7-dichlorofluorescein diacetate assay indicated that citreamicin ε substantially increased the intracellular concentration of reactive oxygen species (ROS). To confirm the hypothesis that citreamicin ε induced apoptosis through an increase in the intracellular ROS concentration, the oxidized products, oxicitreamicin ε A (3) and B (4), were obtained from a one-step reaction catalyzed by Ag 2O. These products, with a reduced capacity to increase the intracellular ROS concentration, exhibited a significantly weakened cytotoxicity in both HeLa and HepG2 cells compared with that of citreamicin ε A (1) and B (2). © 2013 American Chemical Society.

Simultaneous Multiple MS Binding Assays Addressing D1 and D2 Dopamine Receptors.

Science.gov (United States)

Schuller, Marion; Höfner, Georg; Wanner, Klaus T

2017-10-09

MS Binding Assays are a label-free alternative to radioligand binding assays. They provide basically the same capabilities as the latter, but use a non-labeled reporter ligand instead of a radioligand. In contrast to radioligand binding assays, MS Binding Assays offer-owing to the selectivity of mass spectrometric detection-the opportunity to monitor the binding of different reporter ligands at different targets simultaneously. The present study shows a proof of concept for this strategy as exemplified for MS Binding Assays selectively addressing D 1 and D 2 dopamine receptors in a single binding experiment. A highly sensitive, rapid and robust LC-ESI-MS/MS quantification method capable of quantifying both SCH23390 and raclopride, selectively addressing D 1 and D 2 receptors, respectively, was established and validated for this purpose. Based thereon, simultaneous saturation and competition experiments with SCH23390 and raclopride in the presence of both D 1 and D 2 receptors were performed and analyzed by LC-MS/MS within a single chromatographic cycle. The present study thus demonstrates the feasibility of this strategy and the high versatility of MS Binding Assays that appears to surpass that common for conventional radioligand binding assays. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of radioassay and microbiological assay for serum folate, with clinical assessment of discrepant results

International Nuclear Information System (INIS)

Baril, L.; Carmel, R.

1978-01-01

Folate assays by use of radiolabeled folate provide obvious practical advantages over the standard microbiological assay, but remain incompletely tested. We therefore compared results for 415 sera with a kit involving 3 H-labeled folate and the Lactobacillus casei microbiological method. We examined the patients' data when there were discrepancies between the two methods. Although the correlation overall was satisfactory, results were discrepant in 25% of cases. In 74% of the latter, the radioassay result appeared to be the correct one, primarily because L. casei results were suppressed by antibiotics being taken by the patient. The radioassay occasionally gave falsely high values for patients with liver disease and falsely low ones for patients who had received isotopes for scanning purposes. Several assay kits that make use of 125 I- or 75 Se-labeled folate were also tested. Although these results correlated with the results of 3 H-labeled folate assay, various problems appeared, including the possible need for serum-supernate control tubes in one kit. Answers to these and other questions and careful clinical correlation of results are needed for any folate radioassays before their adoption for routine clinical use

A broad G protein-coupled receptor internalization assay that combines SNAP-tag labeling, diffusion-enhanced resonance energy transfer, and a highly emissive terbium cryptate acceptor

Directory of Open Access Journals (Sweden)

Angélique eLEVOYE

2015-11-01

Full Text Available Although G protein-coupled receptor (GPCR internalization has long been considered a major aspect of the desensitization process that tunes ligand responsiveness, internalization is also involved in receptor resensitization and signaling, as well as the ligand scavenging function of some atypical receptors. Internalization thus contributes to the diversity of GPCR-dependent signaling, and its dynamics and quantification in living cells has generated considerable interest. We developed a robust and sensitive assay to follow and quantify ligand-induced and constitutive GPCR internalization but also receptor recycling in living cells. This assay is based on diffusion-enhanced resonance energy transfer (DERET between cell surface GPCRs labeled with a luminescent terbium cryptate donor and a fluorescein acceptor present in the culture medium. GPCR internalization results in a quantifiable reduction of energy transfer. This method yields a high signal-to-noise ratio due to time-resolved measurements. For various GPCRs belonging to different classes, we demonstrated that constitutive and ligand-induced internalization could be monitored as a function of time and ligand concentration, thus allowing accurate quantitative determination of kinetics of receptor internalization but also half-maximal effective or inhibitory concentrations of compounds. In addition to its selectivity and sensitivity, we provided evidence that DERET-based internalization assay is particularly suitable for characterizing biased ligands. Furthermore, the determination of a Z’-factor value of 0.45 indicates the quality and suitability of DERET-based internalization assay for high-throughput screening (HTS of compounds that may modulate GPCRs internalization.

Andrographolide Sensitizes Ras-Transformed Cells to Radiation in vitro and in vivo

International Nuclear Information System (INIS)

Hung, Shih-Kai; Hung, Ling-Chien; Kuo, Cheng-Deng

2010-01-01

Purpose: Increasing the sensitivity of tumor cells to radiation is a major goal of radiotherapy. The present study investigated the radiosensitizing effects of andrographolide and examined the molecular mechanisms of andrographolide-mediated radiosensitization. Methods and Materials: An H-ras-transformed rat kidney epithelial (RK3E) cell line was used to measure the radiosensitizing effects of andrographolide in clonogenic assays, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide assays, and a xenograft tumor growth model. The mechanism of andrographolide-sensitized cell death was analyzed using annexin V staining, caspase 3 activity assays, and terminal transferase uridyl nick end labeling assays. The roles of nuclear factor kappa B (NF-κB) and Akt in andrographolide-mediated sensitization were examined using reporter assays, electrophoretic mobility shift assays, and Western blotting. Results: Concurrent andrographolide treatment (10 μM, 3 h) sensitized Ras-transformed cells to radiation in vitro (sensitizer enhancement ratio, 1.73). Andrographolide plus radiation (one dose of 300 mg/kg peritumor andrographolide and one dose of 6 Gy radiation) resulted in significant tumor growth delay (27 ± 2.5 days) compared with radiation alone (22 ± 1.5 days; p <.05). Radiation induced apoptotic markers (e.g., caspase-3, membrane reversion, DNA fragmentation), and andrographolide treatment did not promote radiation-induced apoptosis. However, the protein level of activated Akt was significantly reduced by andrographolide. NF-κB activity was elevated in irradiated Ras-transformed cells, and andrographolide treatment significantly reduced radiation-induced NF-κB activity. Conclusion: Andrographolide sensitized Ras-transformed cells to radiation both in vitro and in vivo. Andrographolide-mediated radiosensitization was associated with downregulation of Akt and NF-κB activity. These observations indicate that andrographolide is a novel radiosensitizing agent

New fluorimetric assay of horseradish peroxidase using sesamol as substrate and its application to EIA.

Science.gov (United States)

Arakawa, Hidetoshi; Nakabayashi, Shigeo; Ohno, Ken-Ichi; Maeda, Masako

2012-04-01

Horseradish peroxidase (HRP) is generally used as a label enzyme in enzyme immunoassay (EIA). The procedure used for HRP detection in EIA is critical for sensitivity and precision. This paper describes a novel fluorimetric assay for horseradish peroxidase (HRP) using sesamol as substrate. The principle of the assay is as follow: sesamol (3,4-methylenedioxy phenol) is reacted enzymatically in the presence of hydrogen peroxide to produce dimeric sesamol. The dimer is fluorescent and can be detected sensitively at ex. 347 nm, em. 427 nm. The measurable range of HRP was 1.0×10 -18 to 1.0×10 -15  mol/assay, with a detection limit of 1.0×10 -18  mol/assay. The coefficient of variation (CV, n =8) was examined at each point on the standard curve, with a mean CV percentage of 3.8%. This assay system was applied to thyroid stimulating hormone (TSH) EIA using HRP as the label enzyme.

Development of a VHH-Based Erythropoietin Quantification Assay

DEFF Research Database (Denmark)

Kol, Stefan; Beuchert Kallehauge, Thomas; Adema, Simon

2015-01-01

Erythropoietin (EPO) quantification during cell line selection and bioreactor cultivation has traditionally been performed with ELISA or HPLC. As these techniques suffer from several drawbacks, we developed a novel EPO quantification assay. A camelid single-domain antibody fragment directed against...... human EPO was evaluated as a capturing antibody in a label-free biolayer interferometry-based quantification assay. Human recombinant EPO can be specifically detected in Chinese hamster ovary cell supernatants in a sensitive and pH-dependent manner. This method enables rapid and robust quantification...

Human CD34+ cells engineered to express membrane-bound tumor necrosis factor-related apoptosis-inducing ligand target both tumor cells and tumor vasculature.

Science.gov (United States)

Lavazza, Cristiana; Carlo-Stella, Carmelo; Giacomini, Arianna; Cleris, Loredana; Righi, Marco; Sia, Daniela; Di Nicola, Massimo; Magni, Michele; Longoni, Paolo; Milanesi, Marco; Francolini, Maura; Gloghini, Annunziata; Carbone, Antonino; Formelli, Franca; Gianni, Alessandro M

2010-03-18

Adenovirus-transduced CD34+ cells expressing membrane-bound tumor necrosis factor-related apoptosis-inducing ligand (CD34-TRAIL+ cells) exert potent antitumor activity. To further investigate the mechanism(s) of action of CD34-TRAIL+ cells, we analyzed their homing properties as well as antitumor and antivascular effects using a subcutaneous myeloma model in immunodeficient mice. After intravenous injection, transduced cells homed in the tumor peaking at 48 hours when 188 plus or minus 25 CD45+ cells per 10(5) tumor cells were detected. Inhibition experiments showed that tumor homing of CD34-TRAIL+ cells was largely mediated by vascular cell adhesion molecule-1 and stromal cell-derived factor-1. Both CD34-TRAIL+ cells and soluble (s)TRAIL significantly reduced tumor volume by 40% and 29%, respectively. Computer-aided analysis of TdT-mediated dUTP nick end-labeling-stained tumor sections demonstrated significantly greater effectiveness for CD34-TRAIL+ cells in increasing tumor cell apoptosis and necrosis over sTRAIL. Proteome array analysis indicated that CD34-TRAIL+ cells and sTRAIL activate similar apoptotic machinery. In vivo staining of tumor vasculature with sulfosuccinimidyl-6-(biotinamido) hexanoate-biotin revealed that CD34-TRAIL+ cells but not sTRAIL significantly damaged tumor vasculature, as shown by TdT-mediated dUTP nick end-labeling+ endothelial cells, appearance of hemorrhagic areas, and marked reduction of endothelial area. These results demonstrate that tumor homing of CD34-TRAIL+ cells induces early vascular disruption, resulting in hemorrhagic necrosis and tumor destruction.

Nucleotide sequence of the 3' ends of the double-stranded RNAs of grapevine chrome mosaic nepovirus.

Science.gov (United States)

Le Gall, O; Candresse, T; Dunez, J

1988-02-01

Attempts were made to label the termini of dsRNAs corresponding to the two genomic RNAs of grapevine chrome mosaic nepovirus (GCMV). It was not possible to label the 5' ends of the dsRNAs with [gamma-32P]ATP, which suggests that a genome-linked protein blocks their 5' ends. Both dsRNA species were labelled at their 3' ends with pCp. The 3'-terminal sequences were determined by 'wandering spot' or by partial enzymic cleavage analysis. One strand (presumably positive) ended in a poly(A) 30 to 50 nucleotides long whereas the other (presumably negative) ended in 3'-ACCUUUUAAAAAG (RNA1) or 3'-ACCUUUUAAUAAAG (RNA2). The sequences resemble closely those complementary to the 5' ends of the RNAs of tomato black ring virus (strain S), which is distantly related to GCMV.

Modest blood pressure reduction with valsartan in acute ischemic stroke: a prospective, randomized, open-label, blinded-end-point trial.

Science.gov (United States)

Oh, Mi Sun; Yu, Kyung-Ho; Hong, Keun-Sik; Kang, Dong-Wha; Park, Jong-Moo; Bae, Hee-Joon; Koo, Jaseong; Lee, Juneyoung; Lee, Byung-Chul

2015-07-01

To assess the efficacy and safety of modest blood pressure (BP) reduction with valsartan within 48 h after symptom onset in patients with acute ischemic stroke and high BP. This was a multicenter, prospective, randomized, open-label, blinded-end-point trial. A total of 393 subjects were recruited at 28 centers and then randomly assigned in a 1:1 ratio to receive valsartan (n = 195) or no treatment (n = 198) for seven-days after presentation. The primary outcome was death or dependency, defined as a score of 3-6 on the modified Rankin Scale (mRS) at 90 days after symptom onset. Early neurological deterioration (END) within seven-days and 90-day major vascular events were also assessed. There were 372 patients who completed the 90-day follow-up. The valsartan group had 46 of 187 patients (24·6%) with a 90-day mRS 3-6, compared with 42 of 185 patients (22·6%) in the control group (odds ratio [OR], 1·11; 95% confidence interval [CI], 0·69-1·79; P = 0·667). The rate of major vascular events did not differ between groups (OR, 1·41; 95% CI, 0·44-4·49; P = 0·771). There was a significant increase of END in the valsartan group (OR, 2·43; 95% CI, 1·25-4·73; P = 0·008). Early reduction of BP with valsartan did not reduce death or dependency and major vascular events at 90 days, but increased the risk of END. © 2015 World Stroke Organization.

G protein-coupled receptor internalization assays in the high-content screening format.

Science.gov (United States)

Haasen, Dorothea; Schnapp, Andreas; Valler, Martin J; Heilker, Ralf

2006-01-01

High-content screening (HCS), a combination of fluorescence microscopic imaging and automated image analysis, has become a frequently applied tool to study test compound effects in cellular disease-modeling systems. This chapter describes the measurement of G protein-coupled receptor (GPCR) internalization in the HCS format using a high-throughput, confocal cellular imaging device. GPCRs are the most successful group of therapeutic targets on the pharmaceutical market. Accordingly, the search for compounds that interfere with GPCR function in a specific and selective way is a major focus of the pharmaceutical industry today. This chapter describes methods for the ligand-induced internalization of GPCRs labeled previously with either a fluorophore-conjugated ligand or an antibody directed against an N-terminal tag of the GPCR. Both labeling techniques produce robust assay formats. Complementary to other functional GPCR drug discovery assays, internalization assays enable a pharmacological analysis of test compounds. We conclude that GPCR internalization assays represent a valuable medium/high-throughput screening format to determine the cellular activity of GPCR ligands.

The effect of label affinity on the sensitivity and specificity of a hapten radioimmunoassay: A comparison of three [125I]diphenylhydantoin radioligands with the 14C-labelled drug

International Nuclear Information System (INIS)

Rowell, F.J.

1979-01-01

The effects on the sensitivity and specificity of a radioimmunoassay for diphenylhydantoin (DPH) has been investigated using three 125 I-labelled tyrosine ester derivatives of DPH having different bridge lengths between the tyrosine moiety and the DPH moeity and 14 C-labelled DPH. The results demonstrate that for a hapten which does not completely fill the antibody binding sites, greatest sensitivity is achieved when the bridge of the iodine label is most dissimilar to that present in the original immunogen, when the hapten and label affinities are nearly equivalent. Greatest specificity is achieved with the label which most resembles the original immunogen. These results illustrate the difficulty of designing satisfactory labels for assays of both high specificity and sensitivity since minimal changes in label structure may produce greatly amplified changes in the subsequent affinity of the label for the antiserum. (Auth.)

A novel duplex real-time reverse transcriptase-polymerase chain reaction assay for the detection of hepatitis C viral RNA with armored RNA as internal control

Directory of Open Access Journals (Sweden)

Meng Shuang

2010-06-01

Full Text Available Abstract Background The hepatitis C virus (HCV genome is extremely heterogeneous. Several HCV infections can not be detected using currently available commercial assays, probably because of mismatches between the template and primers/probes. By aligning the HCV sequences, we developed a duplex real-time reverse transcriptase-polymerase chain reaction (RT-PCR assay using 2 sets of primers/probes and a specific armored RNA as internal control. The 2 detection probes were labelled with the same fluorophore, namely, 6-carboxyfluorescein (FAM, at the 5' end; these probes could mutually combine, improving the power of the test. Results The limit of detection of the duplex primer/probe assay was 38.99 IU/ml. The sensitivity of the assay improved significantly, while the specificity was not affected. All HCV genotypes in the HCV RNA Genotype Panel for Nucleic Acid Amplification Techniques could be detected. In the testing of 109 serum samples, the performance of the duplex real-time RT-PCR assay was identical to that of the COBAS AmpliPrep (CAP/COBAS TaqMan (CTM assay and superior to 2 commercial HCV assay kits. Conclusions The duplex real-time RT-PCR assay is an efficient and effective viral assay. It is comparable with the CAP/CTM assay with regard to the power of the test and is appropriate for blood-donor screening and laboratory diagnosis of HCV infection.

A novel multiparametric flow cytometry-based cytotoxicity assay simultaneously immunophenotypes effector cells: Comparisons to a 4 h 51Cr-release assay

OpenAIRE

Kim, GG; Donnenberg, VS; Donnenberg, AD; Gooding, W; Whiteside, TL

2007-01-01

Natural killer (NK) cell- or T cell-mediated cytotoxicity traditionally is measured in 4-16h 51Cr-release assays (CRA). A new four-color flow cytometry-based cytotoxicity assay (FCC) was developed to simultaneously measure NK cell cytotoxicity and NK cell phenotype (CD3−CD16+CD56+). Target cells, K562 or Daudi, were labeled with Cell Tracker Orange (CTO) prior to the addition of effector cells. Following co-incubation, 7 amino-actinomycin D (7-AAD) was added to measure death of target cells. ...

An indirect antibody assay using haptenated antigen and 125I-labelled anti-hapten antibody

International Nuclear Information System (INIS)

Aalberse, R.C.; Amsterdam Univ.

1978-01-01

Hapten (trinitrophenyl) was coupled to antigen (ovalbumin). The haptenated antigen was bound by anti-ovalbumin antibody and binding was quantitated with 125 I-labelled anti-hapten antibodies. Thus, with a single radioactive reagent, antibodies against a variety of antigens can be detected while the problems inherent in a labelled antiglobulin binding test are avoided. In the ovalbumin system, the haptenated antigen binding test proved to be approximately 20 times as sensitive as the iodinated ovalbumin binding test

Diagnostic sensitivity of two radio receptor assays (TRAK Assay and TRAK Dyno human) for the detection of TSH receptor antibodies

International Nuclear Information System (INIS)

Paunkovic, N.; Paunkovic, J.

2003-01-01

Radio receptor assays for the detection of TSH receptor antibodies in serum are typically based on binding the competition of TSH-R antibodies and 125I -labelled-TSH for membrane preparation of thyrocytes (TBII tests). The sensitivity of the available tests utilizing porcine cell membranes was found to be around 80%. A new test (TRAK Dyno human, BRAHMS) utilizes human recombinant TSH receptor and human standard material that is supposed to improve the performance of the test. We have compared the results of these two assays. The sensitivity of the TRAK Assay tested in 356 patients with untreated Grave's disease was found to be 85%, and 97.5% for TRAK Dyno human in 111 newly diagnosed patients. Both tests were performed from the same serum specimen for 60 of the investigated patients. The TRAK Assay was positive in 50 patients (83.2%) and TRAK Dyno human in 59 patients (98.3%). The specificity of the new radio receptor assay was also improved. (author)

Catalytic properties of the Gas family β-(1,3)-glucanosyltransferases active in fungal cell-wall biogenesis as determined by a novel fluorescent assay.

Science.gov (United States)

Mazáň, Marián; Ragni, Enrico; Popolo, Laura; Farkaš, Vladimír

2011-09-01

BGTs [β-(1,3)-glucanosyltransglycosylases; EC 2.4.1.-] of the GH72 (family 72 of glycosylhydrolases) are GPI (glycosylphosphatidylinositol)-anchored proteins that play an important role in the biogenesis of fungal cell walls. They randomly cleave glycosidic linkages in β-(1,3)-glucan chains and ligate the polysaccharide portions containing newly formed reducing ends to C(3)(OH) at non-reducing ends of other β-(1,3)-glucan molecules. We have developed a sensitive fluorescence-based method for the assay of transglycosylating activity of GH72 enzymes. In the new assay, laminarin [β-(1,3)-glucan] is used as the glucanosyl donor and LamOS (laminarioligosaccharides) fluorescently labelled with SR (sulforhodamine) serve as the acceptors. The new fluorescent assay was employed for partial biochemical characterization of the heterologously expressed Gas family proteins from the yeast Saccharomyces cerevisiae. All the Gas enzymes specifically used laminarin as the glucanosyl donor and a SR-LamOS of DP (degree of polymerization) ≥5 as the acceptors. Gas proteins expressed in distinct stages of the yeast life cycle showed differences in their pH optima. Gas1p and Gas5p, which are expressed during vegetative growth, had the highest activity at pH 4.5 and 3.5 respectively, whereas the sporulation-specific Gas2p and Gas4p were most active between pH 5 and 6. The novel fluorescent assay provides a suitable tool for the screening of potential glucanosyltransferases or their inhibitors.

A sensitive assay for Staphylococcus aureus nucleases

Energy Technology Data Exchange (ETDEWEB)

Kohli, J K; Vakil, B V; Patil, M S; Pandey, V N; Pradhan, D S [Bhabha Atomic Reserach Centre, Bombay (India). Biochemistry Div.

1989-10-01

A sensitive assay for staphylococcal nuclease involving incubation of the enzyme sample with heat-denatured ({sup 3}H) thymidine labelled DNA from E.coli, precipitation with trichloroacetic acid and measurement of the radioactivity of acid-soluble nucleotides released has been developed. The assay is sensitive enough to be used for comparing the levels of nucleases elaborated by different strains of S. aureus as well as for determining the extent of contamination of S. aureus in food and water samples even at levels at which the conventional spectrophotometric and toluidine blue-DNA methods are totally inadequate. (author). 26 refs., 3 figs ., 3 tabs.

Lower sperm DNA fragmentation after r-FSH administration in functional hypogonadotropic hypogonadism.

Science.gov (United States)

Ruvolo, Giovanni; Roccheri, Maria Carmela; Brucculeri, Anna Maria; Longobardi, Salvatore; Cittadini, Ettore; Bosco, Liana

2013-04-01

An observational clinical and molecular study was designed to evaluate the effects of the administration of recombinant human FSH on sperm DNA fragmentation in men with a non-classical form of hypogonadotropic hypogonadism and idiopathic oligoasthenoteratozoospermia. In the study were included 53 men with a non-classical form of hypogonadotropic hypogonadism and idiopathic oligoasthenoteratozoospermia. In all patients, sperm DNA fragmentation index (DFI), assessed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) in situ DNA nick end-labelling (TUNEL) assay, was evaluated before starting the treatment with 150 IU of recombinant human FSH, given three times a week for at least 3 months. Patients' semen analysis and DNA fragmentation index were re-evaluated after the 3-month treatment period. After recombinant human FSH therapy, we did not find any differences in terms of sperm count, motility and morphology. The average DNA fragmentation index was significantly reduced (21.15 vs 15.2, p15 %), while no significant variation occurred in the patients with DFI values ≤ 15 %. Recombinant human FSH administration improves sperm DNA integrity in hypogonadotropic hypogonadism and idiopathic oligoasthenoteratozoospermia men with DNA fragmentation index value >15 % .

Antenatal taurine reduces cerebral cell apoptosis in fetal rats with intrauterine growth restriction.

Science.gov (United States)

Liu, Jing; Wang, Xiaofeng; Liu, Ying; Yang, Na; Xu, Jing; Ren, Xiaotun

2013-08-15

From pregnancy to parturition, Sprague-Dawley rats were daily administered a low protein diet to establish a model of intrauterine growth restriction. From the 12(th) day of pregnancy, 300 mg/kg rine was daily added to food until spontaneous delivery occurred. Brain tissues from normal neonatal rats at 6 hours after delivery, neonatal rats with intrauterine growth restriction, and neonatal rats with intrauterine growth restriction undergoing taurine supplement were obtained for further experiments. The terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling assay revealed that the number of apoptotic cells in the brain tissue of neonatal rats with intrauterine growth restriction significantly increased. Taurine supplement in pregnant rats reduced cell apoptosis in brain tissue from neonatal rats with intrauterine growth restriction. nohistochemical staining revealed that taurine supplement increased glial cell line-derived neurotrophic factor expression and decreased caspase-3 expression in the cerebral cortex of intrauterine growth-restricted fetal rats. These results indicate that taurine supplement reduces cell apoptosis through the glial cell line-derived neurotrophic factor-caspase-3 signaling pathway, resulting in a protective effect on the intrauterine growth-restricted fetal rat brain.

Neurotoxic, cytotoxic, apoptotic and antiproliferative effects of some marine algae extracts on the NA2B cell line.

Science.gov (United States)

Kurt, O; Özdal-Kurt, F; Akçora, C M; Özkut, M; Tuğlu, M I

2018-02-01

Oxidative stress contributes to cancer pathologies and to apoptosis. Marine algae exhibit cytotoxic, antiproliferative and apoptotic effects; their metabolites have been used to treat many types of cancer. We investigated in culture extracts of Petalonia fascia, Jania longifurca and Halimeda tuna to determine their effects on mouse neuroblastoma cell line, NA2B. NA2B cells were treated with algae extracts, and the survival and proliferation of NA2B cells were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effects of algae extracts on oxidative stress in NA2B cells also were investigated using nitric oxide synthase (NOS) immunocytochemistry and apoptosis was assessed using terminal deoxynucleotidyl transferase dUTP nick end labeling. We observed significant neurite inhibition with moderate damage by the neurotoxicity-screening test (NST) at IC 50 dilutions of the extracts. MTT demonstrated that J. longifurca extracts were more toxic than P. fascia and H. tuna extracts. We found an increase of endothelial and inducible NOS immunostaining for oxidative stress and TUNEL analysis revealed increased apoptosis after application of extract. Our findings suggest that the algae we tested may have potential use for treatment of cancer.

Premature Tapetum Degeneration: a Major Cause of Abortive Pollen Development in Photoperiod Sensitive Genic Male Sterility in Rice

Institute of Scientific and Technical Information of China (English)

Yinlian Shi; Sha Zhao; Jialing Yao

2009-01-01

Photoperiod-sensitive genic male-sterile (PSGMS) rice (Oryza sativa L.), a natural mutant found in the rice cultivar Nongken 58, is very useful for the development of hybrid rice cultivars. Despite its widespread use in breeding programs, the initial stage of the abortive development of PSGMS rice and the possible cytological mechanisms of pollen abortion have not been determined. In the present study, a systematic cytological comparison of the anther development of PSGMS rice with its normal fertile counterpart is conducted. The results show that pollen abortion in PSGMS rice first occurs before the pollen mother cell (PMC) stage, and continues during the entire process of pollen development until pollen degradation. The abortive process was closely associated with the abnormal behavior of the tapetum. Although tapetum degeneration in PSGMS rice initiates already at the PMC stage, it proceeds slowly and does not complete until the breakdown of the pollen. Such cytological observations were supported by the results of the TUNEL (TdT-mediated dUTP Nick End Labeling) assay, which detects DNA fragmentation resulting from programmed cell death (PCD), indicating that the premature tapetum degeneration is in the process of PCD.

Migration of cochlear lateral wall cells.

Science.gov (United States)

Dunaway, George; Mhaskar, Yashanad; Armour, Gary; Whitworth, Craig; Rybak, Leonard

2003-03-01

The role of apoptosis and proliferation in maintenance of cochlear lateral wall cells was examined. The methods employed for detection of apoptosis were the Hoechst fluorescence stain and TUNEL (TdT-mediated dUTP-biotin nick-end-labeling) assay, and proliferations were 5-bromo-2'-deoxyuridine (BrdU) incorporation and presence of the proliferating cell nuclear antigen. The incidence of apoptosis in the strial marginal cell was 50% greater (32.9+/-3.7%) than strial intermediate and basal cells but similar to spiral ligament cells. Although division of marginal strial cells was rarely detected, a significant number of proliferating cells in the remaining stria vascularis and spiral ligament were observed. These data implied that replacement of marginal cells arose elsewhere and could be followed by a BrdU-deoxythymidine pulse-chase study. At 2 h post injection, nuclear BrdU in marginal cells was not detected; however, by 24 h post injection, 20-25% of marginal cell nuclei were BrdU-positive. These observations are consistent with the hypothesis that marginal cells were replaced by underlying cells. Cell migration appears to be an important mechanism for preserving the function and structure of the stria vascularis.

[Effect of jiaotai pill on pancreatic fat accumulation and islet cell apoptosis in rats with type 2 diabetes].

Science.gov (United States)

Zou, Xin; Liu, De-Liang; Lu, Fu-Er; Dong, Hui; Xu, Li-Jun; Luo, Yun-Huan; Wang, Kai-Fu

2014-06-01

In this study, the rat type 2 diabetes mellitus (T2DM) model was established through tail vein injection with low dose of streptozotocin (STZ) and high fat diet for 8 weeks, and then treated with Jiaotai Pill. The oral glucose tolerance test (OGTT), fasting serum insulin (FINS), free fatty acid(FFA) levels and blood lipid were assayed. HOMA-IR was calculated. Pancreatic pathology was performed. And pancreatic triglyceride (TG) content was examined by the lipid extraction method. Pancreatic islet cell apoptosis were detected by terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL). According to the results, the model group showed abnormal OGTT, increased FINS, HOMA-IR, FFA, lipid disorder, obvious fat accumulation and significantly increased TG content in pancreatic tissues, and enhanced pancreatic islet cell apoptosis. Compared with the model group, the Jiaotai Pill group displayed improved OGTT, reduced FINS, HOMA-IR, FFA, recovered lipid disorder, decreased fat accumulation and significantly declined TG content in pancreatic tissues, and lowered pancreatic islet cell apoptosis. In summary, Jiaotai pill could effectively treat type 2 diabetes in rats. Its mechanism may be related to the reduction in pancreatic fat accumulation and islet cell apoptosis.

Effects of alpha particles on zebrafish embryos

International Nuclear Information System (INIS)

Yum, E.H.W.; Choi, V.W.Y.; Yu, K.N.; Li, V.W.T.; Cheng, S.H.

2008-01-01

Full text: Ionizing radiation such as X-ray and alpha particles can damage cellular macromolecules, which can lead to DNA single- and double-strand breaks. In the present work, we studied the effects of alpha particles on dechorionated zebrafish embryos. Thin polyallyldiglycol carbonate (PADC) films with a thickness of 16 μm were prepared from commercially available PADC films (with thickness of 100 μm) by chemical etching and used as support substrates for holding zebrafish embryos for alpha-particle irradiation. These films recorded alpha-particle hit positions, quantified the number and energy of alpha particles actually incident on the embryo cells, and thus enabled the calculation of the dose absorbed by the embryo cells. Irradiation was made at 1.25 hours post fertilization (hpf) with various absorbed dose. TdT-mediated dUTP Nick-End Labeling (TUNEL) assay was performed on the embryos at different time stages after irradiation. Marked apoptosis was detected only in embryos at earlier time stages. The results showed that DNA double-strand break during zebrafish embryogenesis can be induced by alpha-particle irradiation, which suggests that zebrafish is a potential model for assessing the effects of alpha-particle radiation

Nerve growth factor reduces apoptotic cell death in rat facial motor neurons after facial nerve injury.

Science.gov (United States)

Hui, Lian; Yuan, Jing; Ren, Zhong; Jiang, Xuejun

2015-01-01

To assess the effects of nerve growth factor (NGF) on motor neurons after induction of a facial nerve lesion, and to compare the effects of different routes of NGF injection on motor neuron survival. This study was carried out in the Department of Otolaryngology Head & Neck Surgery, China Medical University, Liaoning, China from October 2012 to March 2013. Male Wistar rats (n = 65) were randomly assigned into 4 groups: A) healthy controls; B) facial nerve lesion model + normal saline injection; C) facial nerve lesion model + NGF injection through the stylomastoid foramen; D) facial nerve lesion model + intraperitoneal injection of NGF. Apoptotic cell death was detected using the terminal deoxynucleotidyl transferase dUTP nick end-labeling assay. Expression of caspase-3 and p53 up-regulated modulator of apoptosis (PUMA) was determined by immunohistochemistry. Injection of NGF significantly reduced cell apoptosis, and also greatly decreased caspase-3 and PUMA expression in injured motor neurons. Group C exhibited better efficacy for preventing cellular apoptosis and decreasing caspase-3 and PUMA expression compared with group D (pfacial nerve injury in rats. The NGF injected through the stylomastoid foramen demonstrated better protective efficacy than when injected intraperitoneally.

In vivo prediction of anti-tumor effect of 3-bromopyruvate in hepatocellular carcinoma using Tc-99m labeled annexin-v imaging

Energy Technology Data Exchange (ETDEWEB)

Kim, Won; Yoon, Jung Hwan; Kim, Chung Yang [Seoul National University College of Medicine, Seoul (Korea, Republic of); Cheon, Gi Jeoog; Lee, Tae Sup; Woo, Kwang Sun; Chung, Wee Sup [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2005-07-01

We have recently demonstrated that hypoxia stimulates hepatocellular carcinoma (HCC) cell growth through hexokinase II induction, and its inhibition induces apoptotic cell death through activating mitochondrial apoptotic signaling cascades. In this study, we were apt to evaluate the antitumoral effect of 3-bromopyruvate (3-BP) on in vivo model of HCC by apoptotic imaging using Tc-99m labeled annexin V. In vivo model of HCC was established in C3H mice intradermally implanted with MH134 cells, a mouse HCC cell line, and 3-BP (0, 5, 10 mg/kg) was subsequently administered intraperitoneally. Tc-99m-HYNIC-annexin V (185 KBq) was injected via tail vein at one and three days after the 3-BP treatment, planar scan was acquired at a hour after the injection using gamma camera. The anti-tumor effect was evaluated by measuring tumor volumes and quantification of apoptotic cells using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Tumor volume was significantly reduced in mice treated with 3-BP in a dose-dependent manner (mean tumor volume 1.07 vs. 0.58 vs. 0.39 cm{sup 3} in 3-BP 0, 5, 10 mg/kg, respectively: p=0.047). The percentage of TUNEL staining-positive cells was significantly increased in 3-BP-treated mice (0.53 vs. 1.40 vs. 1.84% in 3-BP 0, 5, 10 mg/kg, respectively; p=0.018). On Tc-99m-HYNIC annexin V imaging, tumor-to-background uptake ratio (UR) was 1.92 at one day and 4.23 at three days after 3-BP treatment of 5 mg/kg (non-treated tumor showed UR of 2.93). Apoptosis-inducing anti-tumor effect of 3-BP was able to be demonstrated in in vivo model of HCC by apoptotic in vivo imaging using Tc-99m-HYNIC annexin V.

In vivo prediction of anti-tumor effect of 3-bromopyruvate in hepatocellular carcinoma using Tc-99m labeled annexin-v imaging

International Nuclear Information System (INIS)

Kim, Won; Yoon, Jung Hwan; Kim, Chung Yang; Cheon, Gi Jeoog; Lee, Tae Sup; Woo, Kwang Sun; Chung, Wee Sup

2005-01-01

We have recently demonstrated that hypoxia stimulates hepatocellular carcinoma (HCC) cell growth through hexokinase II induction, and its inhibition induces apoptotic cell death through activating mitochondrial apoptotic signaling cascades. In this study, we were apt to evaluate the antitumoral effect of 3-bromopyruvate (3-BP) on in vivo model of HCC by apoptotic imaging using Tc-99m labeled annexin V. In vivo model of HCC was established in C3H mice intradermally implanted with MH134 cells, a mouse HCC cell line, and 3-BP (0, 5, 10 mg/kg) was subsequently administered intraperitoneally. Tc-99m-HYNIC-annexin V (185 KBq) was injected via tail vein at one and three days after the 3-BP treatment, planar scan was acquired at a hour after the injection using gamma camera. The anti-tumor effect was evaluated by measuring tumor volumes and quantification of apoptotic cells using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Tumor volume was significantly reduced in mice treated with 3-BP in a dose-dependent manner (mean tumor volume 1.07 vs. 0.58 vs. 0.39 cm 3 in 3-BP 0, 5, 10 mg/kg, respectively: p=0.047). The percentage of TUNEL staining-positive cells was significantly increased in 3-BP-treated mice (0.53 vs. 1.40 vs. 1.84% in 3-BP 0, 5, 10 mg/kg, respectively; p=0.018). On Tc-99m-HYNIC annexin V imaging, tumor-to-background uptake ratio (UR) was 1.92 at one day and 4.23 at three days after 3-BP treatment of 5 mg/kg (non-treated tumor showed UR of 2.93). Apoptosis-inducing anti-tumor effect of 3-BP was able to be demonstrated in in vivo model of HCC by apoptotic in vivo imaging using Tc-99m-HYNIC annexin V

Apoptosis of gut-associated lymphoid tissue in rainbow trout Oncorhynchus mykiss after incubation with Candida albicans and bacterial lipopolysaccharide.

Science.gov (United States)

Passantino, L; Ostillio, A; Cianciotta, A; Russo, C; Carrassi, M; Patruno, R; Dhaskali, L; Passantino, G F; Passantino, A

2011-06-01

Until now a few studies have been carried out on the gut lymphoid system in fish despite its protective role in the host. Here, we have evaluated the effects of Candida albicans (Ca) and lipopolysaccaride (LPS) on the pyloric and terminal segments of gut in the rainbow trout Oncorhynchus mykiss. In particular, data show that both Ca and LPS are able to cause apoptosis of intestinal lymphoid cells as detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) procedure. These findings suggest a further modality of gut response in fish to environmental antigens.

Rapid in vitro labeling procedures for two-dimensional gel fingerprinting

International Nuclear Information System (INIS)

Lee, Y.F.; Fowlks, E.R.

1982-01-01

Improvements of existing in vitro procedures for labeling RNA radioactively, and modifications of the two-dimensional polyacrylamide gel electrophoresis system for making RNA fingerprints are described. These improvements are (a) inactivation of phosphatase with nitric acid at pH 2.0 eliminated the phenol-cholorform extraction step during 5'-end labeling with polynucleotide kinase and [γ- 32 P]ATP; (b) ZnSO 4 inactivation of R Nase T 1 results in a highly efficient procedure for 3'-end labeling with T4 ligase and [5'- 32 P]pCp; and (c) a rapid 4-min procedure for variable quantity range of 125 I and RNA results in a qualitative and quantitative sample for high-molecular weight RNA fingerprinting. Thus, these in vitro procedures become rapid and reproducible when combined with two-dimensional gel electrophoresis which eliminates simultaneously labeled impurities. Each labeling procedure is compared, using tobacco mosaic virus, Brome mosaic virus, and polio RNA. A series of Ap-rich oligonucleotides was discovered in the inner genome of Brome mosaic Virus RNA-3

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.

Curcumin protects against acoustic trauma in the rat cochlea.

Science.gov (United States)

Soyalıç, Harun; Gevrek, Fikret; Karaman, Serhat

2017-08-01

In this study we evaluated the therapeutic utility of curcumin in a rodent model of acoustic trauma using histopathology, immunohistochemical, and distortion product otoacoustic emission (DPOAEs) measurements. 28 Wistar albino rats were included in the study and randomly assigned to 4 treatment groups. The first group (group 1) served as the control and was exposed to acoustic trauma alone. Group 2 was the curcumin group. Group 3 was the curcumin plus acoustic trauma group. Group 4 was the saline plus acoustic trauma group. Otoacoustic emission measurements were collected at the end of the experiment and all animals were sacrificed. Cochlea were collected and prepared for TUNEL (TdT-mediated deoxyuridinetriphosphate nick end-labelling) staining assay. Group 3 maintained baseline DPOAEs values at 3000 Hz, 4000 Hz and 8000 Hz on the 3rd and 5th day of the experiment. DPOAEs results were correlated with the immunohistochemical and histopathological findings in all groups. In comparison to the histopathologic control group, Group 1 exhibited a statistically significant increase in apoptotic indices in the organ of Corti, inner hair cell, and outer hair cell areas (p curcumin may protect the cochlear tissues from acoustic trauma in rats. Curcumin injection prior to or after an acoustic trauma reduces cochlear hair cell damage and may protect against hearing loss. Copyright © 2017 Elsevier B.V. All rights reserved.

Shaofu Zhuyu Decoction Regresses Endometriotic Lesions in a Rat Model

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Guanghui Zhu

2018-01-01

Full Text Available The current therapies for endometriosis are restricted by various side effects and treatment outcome has been less than satisfactory. Shaofu Zhuyu Decoction (SZD, a classic traditional Chinese medicinal (TCM prescription for dysmenorrhea, has been widely used in clinical practice by TCM doctors to relieve symptoms of endometriosis. The present study aimed to investigate the effects of SZD on a rat model of endometriosis. Forty-eight female Sprague-Dawley rats with regular estrous cycles went through autotransplantation operation to establish endometriosis model. Then 38 rats with successful ectopic implants were randomized into two groups: vehicle- and SZD-treated groups. The latter were administered SZD through oral gavage for 4 weeks. By the end of the treatment period, the volume of the endometriotic lesions was measured, the histopathological properties of the ectopic endometrium were evaluated, and levels of proliferating cell nuclear antigen (PCNA, CD34, and hypoxia inducible factor- (HIF- 1α in the ectopic endometrium were detected with immunohistochemistry. Furthermore, apoptosis was assessed using the terminal deoxynucleotidyl transferase (TdT deoxyuridine 5′-triphosphate (dUTP nick-end labeling (TUNEL assay. In this study, SZD significantly reduced the size of ectopic lesions in rats with endometriosis, inhibited cell proliferation, increased cell apoptosis, and reduced microvessel density and HIF-1α expression. It suggested that SZD could be an effective therapy for the treatment and prevention of endometriosis recurrence.

Fluorescence lifetime assays: current advances and applications in drug discovery.

Science.gov (United States)

Pritz, Stephan; Doering, Klaus; Woelcke, Julian; Hassiepen, Ulrich

2011-06-01

Fluorescence lifetime assays complement the portfolio of established assay formats available in drug discovery, particularly with the recent advances in microplate readers and the commercial availability of novel fluorescent labels. Fluorescence lifetime assists in lowering complexity of compound screening assays, affording a modular, toolbox-like approach to assay development and yielding robust homogeneous assays. To date, materials and procedures have been reported for biochemical assays on proteases, as well as on protein kinases and phosphatases. This article gives an overview of two assay families, distinguished by the origin of the fluorescence signal modulation. The pharmaceutical industry demands techniques with a robust, integrated compound profiling process and short turnaround times. Fluorescence lifetime assays have already helped the drug discovery field, in this sense, by enhancing productivity during the hit-to-lead and lead optimization phases. Future work will focus on covering other biochemical molecular modifications by investigating the detailed photo-physical mechanisms underlying the fluorescence signal.

Development of a general methodology for labelling peptide-morpholino oligonucleotide conjugates using alkyne-azide click chemistry.

Science.gov (United States)

Shabanpoor, Fazel; Gait, Michael J

2013-11-11

We describe a general methodology for fluorescent labelling of peptide conjugates of phosphorodiamidate morpholino oligonucleotides (PMOs) by alkyne functionalization of peptides, subsequent conjugation to PMOs and labelling with a fluorescent compound (Cy5-azide). Two peptide-PMO (PPMO) examples are shown. No detrimental effect of such labelled PMOs was seen in a biological assay.

Superparamagnetic iron oxide nanoparticles labeling of bone marrow stromal (mesenchymal cells does not affect their "stemness".

Directory of Open Access Journals (Sweden)

Arun Balakumaran

2010-07-01

Full Text Available Superparamagnetic iron oxide nanoparticles (SPION are increasingly used to label human bone marrow stromal cells (BMSCs, also called "mesenchymal stem cells" to monitor their fate by in vivo MRI, and by histology after Prussian blue (PB staining. SPION-labeling appears to be safe as assessed by in vitro differentiation of BMSCs, however, we chose to resolve the question of the effect of labeling on maintaining the "stemness" of cells within the BMSC population in vivo. Assays performed include colony forming efficiency, CD146 expression, gene expression profiling, and the "gold standard" of evaluating bone and myelosupportive stroma formation in vivo in immuncompromised recipients. SPION-labeling did not alter these assays. Comparable abundant bone with adjoining host hematopoietic cells were seen in cohorts of mice that were implanted with SPION-labeled or unlabeled BMSCs. PB+ adipocytes were noted, demonstrating their donor origin, as well as PB+ pericytes, indicative of self-renewal of the stem cell in the BMSC population. This study confirms that SPION labeling does not alter the differentiation potential of the subset of stem cells within BMSCs.

Competitive binding assay for fructose 2,6-bisphosphate

International Nuclear Information System (INIS)

Thomas, H.; Uyeda, K.

1986-01-01

A new direct assay method for fructose 2,6-bisphosphate has been developed based on competitive binding of labeled and unlabeled fructose 2,6-P 2 to phosphofructokinase. Phosphofructokinase (0.5-1.3 pmol promoter) is incubated with saturating concentrations (5.0-5.5 pmol) of fructose 2,6[2- 32 P]P 2 and samples containing varying concentrations of fructose 2,6-P 2 . The resulting stable binary complex is retained on nitrocellulose filters with a binding efficiency of up to 70%. Standard curves obtained with this assay show strict linearity with varying fructose 2,6-P 2 in the range of 0.5 to 45 pmol, which exceeds the sensitivity of most of the previously described assay methods. Fructose 2,6-P 2 , ATP, and high concentrations of phosphate interfere with this assay. However, the extent of this inhibition is negligible since their tissue contents are one-half to one-tenth that examined. The new assay is simple, direct, rapid, and does not require pretreatment

Supplementary Material for: DRABAL: novel method to mine large high-throughput screening assays using Bayesian active learning

KAUST Repository

Soufan, Othman

2016-01-01

Abstract Background Mining high-throughput screening (HTS) assays is key for enhancing decisions in the area of drug repositioning and drug discovery. However, many challenges are encountered in the process of developing suitable and accurate methods for extracting useful information from these assays. Virtual screening and a wide variety of databases, methods and solutions proposed to-date, did not completely overcome these challenges. This study is based on a multi-label classification (MLC) technique for modeling correlations between several HTS assays, meaning that a single prediction represents a subset of assigned correlated labels instead of one label. Thus, the devised method provides an increased probability for more accurate predictions of compounds that were not tested in particular assays. Results Here we present DRABAL, a novel MLC solution that incorporates structure learning of a Bayesian network as a step to model dependency between the HTS assays. In this study, DRABAL was used to process more than 1.4 million interactions of over 400,000 compounds and analyze the existing relationships between five large HTS assays from the PubChem BioAssay Database. Compared to different MLC methods, DRABAL significantly improves the F1Score by about 22%, on average. We further illustrated usefulness and utility of DRABAL through screening FDA approved drugs and reported ones that have a high probability to interact with several targets, thus enabling drug-multi-target repositioning. Specifically DRABAL suggests the Thiabendazole drug as a common activator of the NCP1 and Rab-9A proteins, both of which are designed to identify treatment modalities for the Niemannâ Pick type C disease. Conclusion We developed a novel MLC solution based on a Bayesian active learning framework to overcome the challenge of lacking fully labeled training data and exploit actual dependencies between the HTS assays. The solution is motivated by the need to model dependencies between

Competitive binding thyroid assay with improved bound-free separation step

International Nuclear Information System (INIS)

1979-01-01

A competitive binding assay is described for serum thyroid hormone using 125 I-labelled thyroid hormone and exogenous thyroid hormone binding protein. The unbound thyroid hormone is separated from thyroid hormone bound to thyroid hormone binding protein using an intermediate base anion exchange resin. This resin comprises tertiary and quaternary amine groups on a polyalkyleneamine lattice and is compressed with microcrystalline cellulose in a tablet form. The assay technique of the present invention employing an intermediate base anion resin was found to give superior results compared with alternative assay techniques used in serum thyroid hormone estimation. (UK)

Urtica dioica dichloromethane extract induce apoptosis from intrinsic pathway on human prostate cancer cells (PC3).

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Mohammadi, A; Mansoori, B; Aghapour, M; Baradaran, B

2016-03-31

Prostate cancer is considered as the major cause of death among men around the world. There are a number of medicinal plants triggering apoptosis response in cancer cells, thus have a therapeutic potential. Therefore, further studies to characterize beneficial properties of these plants in order to introduce novel anti-cancer drugs are the interest of recent researches on the alternative medicine. On the other hand, due to traditional uses and availability of Urtica dioica extract, we decided to evaluate the efficacy of this medicinal herb on pc3 prostate cancer cell line. In the present study the cytotoxic effects of Urtica dioica extract were assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and trypan blue viability dye. Then, DNA fragmentation and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay were exploited to measure cell death and apoptosis stage. The expression levels of caspase 3, caspase 9 and Bcl-2 genes were quantified by Real-Time PCR. Finally, Cell cycle was analyzed by flow cytometry. MTT assay showed that dichloromethanolic extract of Urtica dioica significantly inhibited the cell growth. According to the DNA fragmentation and TUNEL assay results, the herbal extract was able to induce apoptosis in prostate cancer cells. Our findings also demonstrated that the plant extract substantially increases the caspase 3 and 9 mRNA expression, while decreases Bcl-2. Cell cycle arrest was occurred in G2 stage, due to the results of flow cytometry. These results indicate that dichloromethanolic extract of Urtica dioica can successfully induce apoptosis in PC3 cells. Therefore, it could be used as a novel therapeutic candidate for prostate tumor treatment.

Nonviral gene therapy in vivo with PAM-RG4/apoptin as a potential brain tumor therapeutic.

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An, Songhie; Nam, Kihoon; Choi, Sunghyun; Bai, Cheng Z; Lee, Yan; Park, Jong-Sang

2013-01-01

Glioma is still one of the most complicated forms of brain tumor to remove completely due to its location and the lack of an efficient means to specifically eliminate tumor cells. For these reasons, this study has examined the effectiveness of a nonviral gene therapy approach utilizing a tumor-selective killer gene on a brain tumor xenograft model. The therapeutic apoptin gene was recombined into the JDK plasmid and delivered into human brain tumor cells (U87MG) by using a polyamidoamine dendrimer with an arginine surface (PAM-RG4). Studies in vitro showed that the PAM-RG4/apoptin plasmid polyplex exhibited a particularly high transfection activity of .40%. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, 4',6-Diamidino-2-phenylindole (DAPI) TUNEL assay, DAPI staining, and caspase-3 activity assay verified that the tumor cells had undergone apoptosis induced by apoptin. For in vivo studies, the polyplex was injected into tumors, which were induced by injecting U87MG cells intradermally into nude mice. Based on hematoxylin and eosin staining, epidermal growth factor receptor immunohistochemistry results and tumor volume measurement results, tumor growth was effectively inhibited and no specific edema, irritation, or other harm to the skin was observed after polyplex injection. The in vivo expression of apoptin and the induction of apoptosis were verified by reverse-transcription polymerase chain reaction analysis, TUNEL assay, and DAPI staining. The PAM-RG4/apoptin gene polyplex is a strong candidate for brain tumor therapeutics because of the synergistic effect of the carrier's high transfection efficiency (35%-40%) in glioma cells and the selective apoptosis-inducing activity of apoptin in tumor cells.

Targeting Gene-Viro-Therapy with AFP driving Apoptin gene shows potent antitumor effect in hepatocarcinoma

Directory of Open Access Journals (Sweden)

Zhang Kang-Jian

2012-02-01

Full Text Available Abstract Background Gene therapy and viral therapy are used for cancer therapy for many years, but the results are less than satisfactory. Our aim was to construct a new recombinant adenovirus which is more efficient to kill hepatocarcinoma cells but more safe to normal cells. Methods By using the Cancer Targeting Gene-Viro-Therapy strategy, Apoptin, a promising cancer therapeutic gene was inserted into the double-regulated oncolytic adenovirus AD55 in which E1A gene was driven by alpha fetoprotein promoter along with a 55 kDa deletion in E1B gene to form AD55-Apoptin. The anti-tumor effects and safety were examined by western blotting, virus yield assay, real time polymerase chain reaction, 3-(4,5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide assay, Hoechst33342 staining, Fluorescence-activated cell sorting, xenograft tumor model, Immunohistochemical assay, liver function analysis and Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling assay. Results The recombinant virus AD55-Apoptin has more significant antitumor effect for hepatocelluar carcinoma cell lines (in vitro than that of AD55 and even ONYX-015 but no or little impair on normal cell lines. Furthermore, it also shows an obvious in vivo antitumor effect on the Huh-7 liver carcinoma xenograft in nude mice with bigger beginning tumor volume till about 425 mm3 but has no any damage on the function of liver. The induction of apoptosis is involved in AD55-Apoptin induced antitumor effects. Conclusion The AD55-Apoptin can be a potential anti-hepatoma agent with remarkable antitumor efficacy as well as higher safety in cancer targeting gene-viro-therapy system.

Hierarchical Nanogold Labels to Improve the Sensitivity of Lateral Flow Immunoassay

Science.gov (United States)

Serebrennikova, Kseniya; Samsonova, Jeanne; Osipov, Alexander

2018-06-01

Lateral flow immunoassay (LFIA) is a widely used express method and offers advantages such as a short analysis time, simplicity of testing and result evaluation. However, an LFIA based on gold nanospheres lacks the desired sensitivity, thereby limiting its wide applications. In this study, spherical nanogold labels along with new types of nanogold labels such as gold nanopopcorns and nanostars were prepared, characterized, and applied for LFIA of model protein antigen procalcitonin. It was found that the label with a structure close to spherical provided more uniform distribution of specific antibodies on its surface, indicative of its suitability for this type of analysis. LFIA using gold nanopopcorns as a label allowed procalcitonin detection over a linear range of 0.5-10 ng mL-1 with the limit of detection of 0.1 ng mL-1, which was fivefold higher than the sensitivity of the assay with gold nanospheres. Another approach to improve the sensitivity of the assay included the silver enhancement method, which was used to compare the amplification of LFIA for procalcitonin detection. The sensitivity of procalcitonin determination by this method was 10 times better the sensitivity of the conventional LFIA with gold nanosphere as a label. The proposed approach of LFIA based on gold nanopopcorns improved the detection sensitivity without additional steps and prevented the increased consumption of specific reagents (antibodies).

Evaluation of immunoradiometric and ELISA versions of a microtitre plate assay for Bacillus anthracis spores

Energy Technology Data Exchange (ETDEWEB)

Phillips, A P; Martin, K L; Cross, N L [Chemical Defence Experimental Establishment, Porton (UK); Drake, R G [Glasgow Univ. (UK). Inst. of Biochemistry

1984-05-11

Solid-phase indirectly-labelled antibody assays for Bacillus anthracis spores heat-fixed on polystyrene microtitre plates were compared as immunoradiometric assay (IRMA) and enzyme-linked immunosorbent assay (ELISA) versions. Signal-to-noise ratios were usually higher in the IRMA than in the ELISA performed under parallel conditions but replicates were more varied in the IRMA. The antigen detection threshold and resolution limit calculated after regression analysis were broadly comparable in the 2 types of assay.

Repair of pyrimidine dimers in radiation-sensitive mutants rad3, rad4, rad6, and rad9 of Saccharomyces cerevisiae. [nicking

Energy Technology Data Exchange (ETDEWEB)

Prakash, L [Rochester Univ., N.Y. (USA). Dept. of Radiation Biology and Biophysics; Rochester Univ., N.Y. (USA). School of Medicine and Dentistry)

1977-10-01

The ability to remove ultraviolet-induced pyrimidine dimers was examined in four radiation-sensitive mutants of Saccharomyces cerevisiae. The susceptibility of DNA from irradiated cells to nicking by either the T4 uv-endonuclease or an endonuclease activity found in crude extracts of Micrococcus luteus was used to measure the presence of dimers in DNA. The rad3 and rad4 mutants are shown to be defective in dimer excision whereas the rad6 and rad9 mutants are proficient in dimer excision.

Azadioxatriangulenium: a long fluorescence lifetime fluorophore for large biomolecule binding assay

International Nuclear Information System (INIS)

Sørensen, Thomas Just; Thyrhaug, Erling; Szabelski, Mariusz; Gryczynski, Ignacy; Gryczynski, Zygmunt; Luchowski, Rafal; Laursen, Bo W

2013-01-01

Of the many optical bioassays available, sensing by fluorescence anisotropy has great advantages as it provides a sensitive, instrumentally simple, ratiometric method of detection. However, it is hampered by a severe limitation, as the emission lifetime of the label needs to be comparable to the correlation lifetime (tumbling time) of the biomolecule which is labelled. For proteins of moderate size this is on the order of 20–200 ns, which due to practical issues currently limits the choice of labels to the dansyl-type dyes and certain aromatic dyes. These have the significant drawback of UV/blue absorption and emission as well as an often significant solvent sensitivity. Here, we report the synthesis and characterization of a new fluorescent label for high molecular weight biomolecule assay based on the azadioxatriangulenium motif. The NHS ester of the long fluorescence lifetime, red-emitting fluorophore: azadioxatriangulenium (ADOTA-NHS) was conjugated to anti-rabbit Immunoglobulin G (antiIgG). The long fluorescence lifetime was exploited to determine the correlation time of the high molecular weight antibody and its complex with rabbit Immunoglobulin G (IgG) with steady-state fluorescence anisotropy and time-resolved methods: solution phase immuno-assay was performed following either steady-state or time-resolved fluorescence anisotropy. By performing a variable temperature experiment it was determined that the binding of the ligand resulted in an increase in correlation time of more than 75%, and an increase in the steady-state anisotropy of 18%. The results show that the triangulenium class of dyes can be used in anisotropy assay to detect binding events involving biomolecules of far larger size than what is possible with most other red-emitting organic dyes. (paper)

Azadioxatriangulenium: a long fluorescence lifetime fluorophore for large biomolecule binding assay

Science.gov (United States)

Just Sørensen, Thomas; Thyrhaug, Erling; Szabelski, Mariusz; Luchowski, Rafal; Gryczynski, Ignacy; Gryczynski, Zygmunt; Laursen, Bo W.

2013-06-01

Of the many optical bioassays available, sensing by fluorescence anisotropy has great advantages as it provides a sensitive, instrumentally simple, ratiometric method of detection. However, it is hampered by a severe limitation, as the emission lifetime of the label needs to be comparable to the correlation lifetime (tumbling time) of the biomolecule which is labelled. For proteins of moderate size this is on the order of 20-200 ns, which due to practical issues currently limits the choice of labels to the dansyl-type dyes and certain aromatic dyes. These have the significant drawback of UV/blue absorption and emission as well as an often significant solvent sensitivity. Here, we report the synthesis and characterization of a new fluorescent label for high molecular weight biomolecule assay based on the azadioxatriangulenium motif. The NHS ester of the long fluorescence lifetime, red-emitting fluorophore: azadioxatriangulenium (ADOTA-NHS) was conjugated to anti-rabbit Immunoglobulin G (antiIgG). The long fluorescence lifetime was exploited to determine the correlation time of the high molecular weight antibody and its complex with rabbit Immunoglobulin G (IgG) with steady-state fluorescence anisotropy and time-resolved methods: solution phase immuno-assay was performed following either steady-state or time-resolved fluorescence anisotropy. By performing a variable temperature experiment it was determined that the binding of the ligand resulted in an increase in correlation time of more than 75%, and an increase in the steady-state anisotropy of 18%. The results show that the triangulenium class of dyes can be used in anisotropy assay to detect binding events involving biomolecules of far larger size than what is possible with most other red-emitting organic dyes.

The synthetic inhibitor of Fibroblast Growth Factor Receptor PD166866 controls negatively the growth of tumor cells in culture

Directory of Open Access Journals (Sweden)

Castelli Mauro

2009-12-01

Full Text Available Abstract Background Many experimental data evidence that over-expression of various growth factors cause disorders in cell proliferation. The role of the Fibroblast Growth Factors (FGF in growth control is indisputable: in particular, FGF1 and its tyrosine kinase receptor (FGFR1 act through a very complex network of mechanisms and pathways. In this work we have evaluated the antiproliferative activity effect of PD166866, a synthetic molecule inhibiting the tyrosin kinase action of FGFR1. Methods Cells were routinely grown in Dulbecco Modified Eagle's medium supplemented with newborn serum and a penicillin-streptomycin mixture. Cell viability was evaluated by Mosmann assay and by trypan blue staining. DNA damage was assessed by in situ fluorescent staining with Terminal Deoxynucleotidyl Transferase dUTP nick end labeling (TUNEL assay. Assessment of oxidative stress at membrane level was measured by quantitative analysis of the intra-cellular formation of malonyl-dialdheyde (MDA deriving from the decomposition of poly-unsaturated fatty acids. The expression of Poly-ADP-Ribose-Polymerase (PARP, consequent to DNA fragmentation, was evidenced by immuno-histochemistry utilizing an antibody directed against an N-terminal fragment of the enzyme. Results The bioactivity of the drug was investigated on Hela cells. Cytoxicity was assessed by the Mosmann assay and by vital staining with trypan blue. The target of the molecule is most likely the cell membrane as shown by the significant increase of the intracellular concentration of malonyl-dihaldheyde. The increase of this compound, as a consequence of the treatment with PD166866, is suggestive of membrane lipoperoxidation. The TUNEL assay gave a qualitative, though clear, indication of DNA damage. Furthermore we demonstrate intracellular accumulation of poly-ADP-ribose polymerase I. This enzyme is a sensor of nicks on the DNA strands and this supports the idea that treatment with the drug induces cell

Phosphine reduced IgG. A new method for 99mTc labeling immunoglobulins

International Nuclear Information System (INIS)

Arteaga de Murphy, C.; Melendez-Alafort, L.; Martinez-Rivero, O.; Gomez, E.; Ferro-Flores, G.

1997-01-01

A new technetium labeling method for immunoglobulins reduced with tris(2-carboxy-ethyl)phosphine hydrochloride is presented. The Sandoglobulina IgG source was assayed for purity and optimum reagent's concentration and incubation times were determined. It was purified by column chromatography and labelled with Sn 2+ reduced technetium in the presence of MDP. The kit is easy to prepare, labeling efficiency is >(97±1.9)% and stable for 6 hours.The immunoreactivity of the 99 Tc-IgG was verified by electrophoresis and Western blot tests. The IgG retained its structure after both the reducing and labeling processes and it was the only labeled species. (author)

Regulatory effect of Bcl-2 in ultraviolet radiation-induced apoptosis of the mouse crystalline lens.

Science.gov (United States)

Dong, Yuchen; Zheng, Yajuan; Xiao, Jun; Zhu, Chao; Zhao, Meisheng

2016-03-01

The aim of the present study was to analyze the role of Bcl-2 during the process of apoptosis in the mouse crystalline lens. In total, 12 normal mice served as the control group and 12 Bcl-2 knockout (K.O) mice served as the experimental group. The mouse crystalline lens was sampled for the detection of Bcl-2 and caspase-3 expression following exposure to ultraviolet (UV) radiation. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to determine Bcl-2 expression in the groups of normal mice receiving UV radiation or not receiving UV radiation. Samples of the murine crystalline lens were microscopically harvested and analyzed using western blotting. Apoptosis was detected using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. Furthermore, caspase 3 activity was examined using enzyme-linked immunosorbent assay kits, and RT-qPCR was used to analyze caspase-3 expression levels. The results of the present study demonstrated that there was no statistically significant difference in the level of Bcl-2 gene transcription between the two groups. In addition, UV radiation did not change the macrostructure of the crystalline lens in the group of normal mice or the group of Bcl-2 K.O mice. The results of the TUNEL assay indicated that the normal-UV group exhibited a more significant apoptosis level compared with the Bcl-2 K.O-UV group. Furthermore, the mRNA expression level of caspase-3 in the normal-UV group was significantly higher compared with the normal-nonUV group (Plens.

Agmatine protects against cell damage induced by NMDA and glutamate in cultured hippocampal neurons

Science.gov (United States)

Wang, Wei-Ping; Iyo, Abiye H.; Miguel-Hidalgo, Javier; Regunathan, Soundar; Zhu, Meng-Yang

2010-01-01

Agmatine is a polyamine and has been considered as a novel neurotransmitter or neuromodulator in the central nervous system. In the present study, the neuroprotective effect of agmatine against cell damage caused by N-methyl-d-aspartate (NMDA) and glutamate was investigated in cultured rat hippocampal neurons. Lactate dehydrogenase (LDH) activity assay, β-tubulin III immunocytochemical staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end-labeling (TUNEL) assay were conducted to detect cell damage. Exposure of 12-day neuronal cultures of rat hippocampus to NMDA or glutamate for 1 h caused a concentration-dependent neurotoxicity, as indicated by the significant increase in released LDH activities. Addition of 100 µM agmatine into media ablated the neurotoxicity induced by NMDA or glutamate, an effect also produced by the specific NMDA receptor antagonist dizocilpine hydrogen maleate (MK801). Arcaine, an analog of agmatine with similar structure as agmatine, fully prevented the NMDA- or glutamate-induced neuronal damage. Spermine and putrescine, the endogenous polyamine and metabolic products of agmatine without the guanidine moiety of agmatine, failed to show this effect, indicating a structural relevance for this neuroprotection. Immunocytochemical staining and TUNEL assay confirmed the findings in the LDH measurement. That is, agmatine and MK801 markedly attenuated NMDA-induced neuronal death and significantly reduced TUNEL-positive cell numbers induced by exposure of cultured hippocampal neurons to NMDA. Taken together, these results demonstrate that agmatine can protect cultured hippocampal neurons from NMDA- or glutamate-induced excitotoxicity, through a possible blockade of the NMDA receptor channels or a potential anti-apoptotic property. PMID:16546145

Lead discovery for mammalian elongation of long chain fatty acids family 6 using a combination of high-throughput fluorescent-based assay and RapidFire mass spectrometry assay

International Nuclear Information System (INIS)

Takamiya, Mari; Sakurai, Masaaki; Teranishi, Fumie; Ikeda, Tomoko; Kamiyama, Tsutomu; Asai, Akira

2016-01-01

A high-throughput RapidFire mass spectrometry assay is described for elongation of very long-chain fatty acids family 6 (Elovl6). Elovl6 is a microsomal enzyme that regulates the elongation of C12-16 saturated and monounsaturated fatty acids. Elovl6 may be a new therapeutic target for fat metabolism disorders such as obesity, type 2 diabetes, and nonalcoholic steatohepatitis. To identify new Elovl6 inhibitors, we developed a high-throughput fluorescence screening assay in 1536-well format. However, a number of false positives caused by fluorescent interference have been identified. To pick up the real active compounds among the primary hits from the fluorescence assay, we developed a RapidFire mass spectrometry assay and a conventional radioisotope assay. These assays have the advantage of detecting the main products directly without using fluorescent-labeled substrates. As a result, 276 compounds (30%) of the primary hits (921 compounds) in a fluorescence ultra-high-throughput screening method were identified as common active compounds in these two assays. It is concluded that both methods are very effective to eliminate false positives. Compared with the radioisotope method using an expensive 14 C-labeled substrate, the RapidFire mass spectrometry method using unlabeled substrates is a high-accuracy, high-throughput method. In addition, some of the hit compounds selected from the screening inhibited cellular fatty acid elongation in HEK293 cells expressing Elovl6 transiently. This result suggests that these compounds may be promising lead candidates for therapeutic drugs. Ultra-high-throughput fluorescence screening followed by a RapidFire mass spectrometry assay was a suitable strategy for lead discovery against Elovl6. - Highlights: • A novel assay for elongation of very-long-chain fatty acids 6 (Elovl6) is proposed. • RapidFire mass spectrometry (RF-MS) assay is useful to select real screening hits. • RF-MS assay is proved to be beneficial because of

Peptide deformylase as an antibacterial drug target: assays for detection of its inhibition in Escherichia coli cell homogenates and intact cells.

Science.gov (United States)

Apfel, C M; Evers, S; Hubschwerlen, C; Pirson, W; Page, M G; Keck, W

2001-04-01

An assay was developed to determine the activity of peptide deformylase (PDF) inhibitors under conditions as close as possible to the physiological situation. The assay principle is the detection of N-terminal [35S]methionine labeling of a protein that contains no internal methionine. If PDF is active, the deformylation of the methionine renders the peptide a substrate for methionine aminopeptidase, resulting in the removal of the N-terminal methionine label. In the presence of a PDF inhibitor, the deformylation is blocked so that the N-formylated peptide is not processed and the label is detected. Using this assay, it is possible to determine the PDF activity under near-physiological conditions in a cell-free transcription-translation system as well as in intact bacterial cells.

Non-Animal Testing Approach to EPA Labeling for Eye Irritation

Science.gov (United States)

This document is an update to EPA’s 2013 published alternative testing approach (using in vitro/ex vivo assays) for determination of eye irritation potential in the pesticide program under EPA's classification and labeling system.

The relationship among expressions, labels, and descriptions of contempt.

Science.gov (United States)

Matsumoto, David; Ekman, Paul

2004-10-01

This article reports 4 studies that demonstrate that the contempt expression is reliably associated with situations that elicit contempt and that the inability to label the contempt expression reflects a problem with its label or concept and not with the relationship between its expression and emotion. In Study I, the labeling of contempt in fixed-choice judgment tasks did not occur because of a process of elimination. In Studies 2 and 3, the contempt expression was associated with situations that elicit contempt, but participants did not label the situations in an open-ended response. In Study 3, participants also more reliably labeled the contempt expression with situations rather than with labels and did not generate contempt situations from labels. In Study 4, participants reported using, hearing, and reading about contempt the least among 7 emotions tested. (c) 2004 APA, all rights reserved

Coupling liquid chromatography/mass spectrometry detection with microfluidic droplet array for label-free enzyme inhibition assay.

Science.gov (United States)

Wang, Xiu-Li; Zhu, Ying; Fang, Qun

2014-01-07

In this work, the combination of droplet-based microfluidics with liquid chromatography/mass spectrometry (LC/MS) was achieved, for providing a fast separation and high-information-content detection method for the analysis of nanoliter-scale droplets with complex compositions. A novel interface method was developed using an oil-covered droplet array chip to couple with an LC/MS system via a capillary sampling probe and a 4 nL injection valve without the need of a droplet extraction device. The present system can perform multistep operations including parallel enzyme inhibition reactions in nanoliter droplets, 4 nL sample injection, fast separation with capillary LC, and label-free detection with ESI-MS, and has significant flexibility in the accurate addressing and sampling of droplets of interest on demand. The system performance was evaluated using angiotensin I and angiotensin II as model samples, and the repeatabilities of peak area for angiotensin I and angiotensin II were 2.7% and 7.5% (RSD, n = 4), respectively. The present system was further applied to the screening for inhibitors of cytochrome P450 (CYP1A2) and measurement of the IC50 value of the inhibitor. The sample consumption for each droplet assay was 100 nL, which is reduced 10-100 times compared with conventional 384-multi-well plate systems usually used in high-throughput drug screening.

Analysis of cis and trans Requirements for DNA Replication at the Right-End Hairpin of the Human Bocavirus 1 Genome.

Science.gov (United States)

Shen, Weiran; Deng, Xuefeng; Zou, Wei; Engelhardt, John F; Yan, Ziying; Qiu, Jianming

2016-09-01

Parvoviruses are single-stranded DNA viruses that use the palindromic structures at the ends of the viral genome for their replication. The mechanism of parvovirus replication has been studied mostly in the dependoparvovirus adeno-associated virus 2 (AAV2) and the protoparvovirus minute virus of mice (MVM). Here, we used human bocavirus 1 (HBoV1) to understand the replication mechanism of bocaparvovirus. HBoV1 is pathogenic to humans, causing acute respiratory tract infections, especially in young children under 2 years old. By using the duplex replicative form of the HBoV1 genome in human embryonic kidney 293 (HEK293) cells, we identified the HBoV1 minimal replication origin at the right-end hairpin (OriR). Mutagenesis analyses confirmed the putative NS1 binding and nicking sites within the OriR. Of note, unlike the large nonstructural protein (Rep78/68 or NS1) of other parvoviruses, HBoV1 NS1 did not specifically bind OriR in vitro, indicating that other viral and cellular components or the oligomerization of NS1 is required for NS1 binding to the OriR. In vivo studies demonstrated that residues responsible for NS1 binding and nicking are within the origin-binding domain. Further analysis identified that the small nonstructural protein NP1 is required for HBoV1 DNA replication at OriR. NP1 and other viral nonstructural proteins (NS1 to NS4) colocalized within the viral DNA replication centers in both OriR-transfected cells and virus-infected cells, highlighting a direct involvement of NP1 in viral DNA replication at OriR. Overall, our study revealed the characteristics of HBoV1 DNA replication at OriR, suggesting novel characteristics of autonomous parvovirus DNA replication. Human bocavirus 1 (HBoV1) causes acute respiratory tract infections in young children. The duplex HBoV1 genome replicates in HEK293 cells and produces progeny virions that are infectious in well-differentiated airway epithelial cells. A recombinant AAV2 vector pseudotyped with an HBoV1

Label-free integrative pharmacology on-target of drugs at the β2-adrenergic receptor

Science.gov (United States)

Ferrie, Ann M.; Sun, Haiyan; Fang, Ye

2011-07-01

We describe a label-free integrative pharmacology on-target (iPOT) method to assess the pharmacology of drugs at the β2-adrenergic receptor. This method combines dynamic mass redistribution (DMR) assays using an array of probe molecule-hijacked cells with similarity analysis. The whole cell DMR assays track cell system-based, ligand-directed, and kinetics-dependent biased activities of the drugs, and translates their on-target pharmacology into numerical descriptors which are subject to similarity analysis. We demonstrate that the approach establishes an effective link between the label-free pharmacology and in vivo therapeutic indications of drugs.

Hybridization chain reaction-based colorimetric aptasensor of adenosine 5'-triphosphate on unmodified gold nanoparticles and two label-free hairpin probes.

Science.gov (United States)

Gao, Zhuangqiang; Qiu, Zhenli; Lu, Minghua; Shu, Jian; Tang, Dianping

2017-03-15

This work designs a new label-free aptasensor for the colorimetric determination of small molecules (adenosine 5'-triphosphate, ATP) by using visible gold nanoparticles as the signal-generation tags, based on target-triggered hybridization chain reaction (HCR) between two hairpin DNA probes. The assay is carried out referring to the change in the color/absorbance by salt-induced aggregation of gold nanoparticles after the interaction with hairpins, gold nanoparticles and ATP. To construct such an assay system, two hairpin DNA probes with a short single-stranded DNA at the sticky end are utilized for interaction with gold nanoparticles. In the absence of target ATP, the hairpin DNA probes can prevent gold nanoparticles from the salt-induced aggregation through the interaction of the single-stranded DNA at the sticky end with gold nanoparticles. Upon target ATP introduction, the aptamer-based hairpin probe is opened to expose a new sticky end for the strand-displacement reaction with another complementary hairpin, thus resulting in the decreasing single-stranded DNA because of the consumption of hairpins. In this case, gold nanoparticles are uncovered owing to the formation of double-stranded DNA, which causes their aggregation upon addition of the salt, thereby leading to the change in the red-to-blue color. Under the optimal conditions, the HCR-based colorimetric assay presents good visible color or absorbance responses for the determination of target ATP at a concentration as low as 1.0nM. Importantly, the methodology can be further extended to quantitatively or qualitatively monitor other small molecules or biotoxins by changing the sequence of the corresponding aptamer. Copyright © 2016 Elsevier B.V. All rights reserved.

Infrared microspectroscopy of live cells in microfluidic devices (MD-IRMS): toward a powerful label-free cell-based assay.

Science.gov (United States)

Vaccari, L; Birarda, G; Businaro, L; Pacor, S; Grenci, G

2012-06-05

Until nowadays most infrared microspectroscopy (IRMS) experiments on biological specimens (i.e., tissues or cells) have been routinely carried out on fixed or dried samples in order to circumvent water absorption problems. In this paper, we demonstrate the possibility to widen the range of in-vitro IRMS experiments to vibrational analysis of live cellular samples, thanks to the development of novel biocompatible IR-visible transparent microfluidic devices (MD). In order to highlight the biological relevance of IRMS in MD (MD-IRMS), we performed a systematic exploration of the biochemical alterations induced by different fixation protocols, ethanol 70% and formaldehyde solution 4%, as well as air-drying on U937 leukemic monocytes by comparing their IR vibrational features with the live U937 counterpart. Both fixation and air-drying procedures affected lipid composition and order as well as protein structure at a different extent while they both induced structural alterations in nucleic acids. Therefore, only IRMS of live cells can provide reliable information on both DNA and RNA structure and on their cellular dynamic. In summary, we show that MD-IRMS of live cells is feasible, reliable, and biologically relevant to be recognized as a label-free cell-based assay.

Labeling of human immune gamma globulin with sup(99m)Tc

International Nuclear Information System (INIS)

Wong, D.W.; Huang, J.T.

1977-01-01

Human immune serum gamma globulin and rabbit anti-Stap. aureus antibody have been successfully labeled with sup(99m)Tc at pH 7.4 with an average binding efficiency of 86 and 82%, respectively. The labeled proteins behave similarly to unlabeled gamma-globulin fraction in the normal human serum as demonstrated by protein electrophoresis. The biological half-time of sup(99m)Tc-gamma-globulin in dog has been determined to be 54 min for the fast component and 14.7 hr for a slower component. Immunological assays demonstrate no significant change in antibody activity after labeling process. (author)

In vitro and in vivo comparison of binding of 99m-Tc-labeled anti-CEA MAb F33-104 with 99m-Tc-labeled anti-CEA MAb BW431/26

International Nuclear Information System (INIS)

Watanabe, N.; Gunma Univ. School of Medicine; Oriuchi, N.; Inoue, T.; Sugiyama, S.; Kuroki, M.; Matsuoka, Y.; Tanada, S.; Murata, H.; Sasaki, Y.

1999-01-01

Aim: The purpose of this study was to assess the potential for radioimmunodetection (RAID) of murine anti-carcinoembryonic antigen (CEA) monoclonal antibody (MAb) F33-104 labeled with technetium-99m (99m-Tc) by a reduction-mediated labeling method. Methods: The binding capacity of 99m-Tc-labeled anti-CEA MAb F33-104 with CEA by means of in vitro procedures such as immunoradiometric assay and cell binding assay and the biodistribution of 99m-Tc-labeled anti-CEA MAb F33-104 in normal nude mice and nude mice bearing human colon adenocarcinoma LS180 tumor were investigated and compared with 99m-Tc-labeled anti-CEA MAb BW431/26. Results: The in vitro binding rate of 99m-Tc-labeled anti-CEA MAb F33-104 with CEA in solution and attached to the cell membrane was significantly higher than 99m-Tc-labeled anti-CEA MAb BW431/261 (31.4 ± 0.95% vs. 11.9 ± 0.55% at 100 ng/mL of soluble CEA, 83.5 ± 2.84% vs. 54.0 ± 2.54% at 10 7 of LS 180 cells). In vivo, accumulation of 99m-Tc-labeled anti-CEA MAb F33-104 was higher at 18 h postinjection than 99m-Tc-labeled anti-CEA MAb BW431/26 (20.1 ± 3.50% ID/g vs. 14.4 ± 3.30% ID/g). 99m-Tc-activity in the kidneys of nude mice bearing tumor was higher at 18 h postinjection than at 3 h (12.8 ± 2.10% ID/g vs. 8.01 ± 2.40% ID/g of 99m-Tc-labeled anti-CEA MAb F33-104, 10.7 ± 1.70% ID/g vs. 8.10 ± 1.75% ID/g of 99m-Tc-labeled anti-CEA MAb BW431/26). Conclusion: 99m-Tc-labeled anti-CEA MAb F33-104 is a potential novel agent for RAID of recurrent colorectal cancer. (orig.) [de

Fluorescent assay for oxytetracycline based on a long-chain aptamer assembled onto reduced graphene oxide

Energy Technology Data Exchange (ETDEWEB)

Zhao, Huimin; Gao, Sheng; Liu, Meng; Chang, Yangyang; Fan, Xinfei; Quan, Xie [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024 (China)

2013-07-15

We report on a fluorescent assay for oxytetracycline (OTC) using a fluorescein-labeled long-chain aptamer assembled onto reduced graphene oxide (rGO). The π-π stacking interaction between aptamer and rGO causes the fluorescence of the label to be almost completely quenched via energy transfer so that the system has very low background fluorescence. The addition of OTC leads to the formation of G-quadruplex OTC complexes and prevents the adsorption of labeled aptamer on the surface of rGO. As a result, fluorescence is restored, and this effect allows for a quantitative assay of OTC over the 0.1–2 μM concentration range and with a detection limit of 10 nM. This method is simple, rapid, selective and sensitive. It may be applied to other small molecule analytes by applying appropriate aptamers. (author)

Fluorescent assay for oxytetracycline based on a long-chain aptamer assembled onto reduced graphene oxide

International Nuclear Information System (INIS)

Zhao, Huimin; Gao, Sheng; Liu, Meng; Chang, Yangyang; Fan, Xinfei; Quan, Xie

2013-01-01

We report on a fluorescent assay for oxytetracycline (OTC) using a fluorescein-labeled long-chain aptamer assembled onto reduced graphene oxide (rGO). The π-π stacking interaction between aptamer and rGO causes the fluorescence of the label to be almost completely quenched via energy transfer so that the system has very low background fluorescence. The addition of OTC leads to the formation of G-quadruplex OTC complexes and prevents the adsorption of labeled aptamer on the surface of rGO. As a result, fluorescence is restored, and this effect allows for a quantitative assay of OTC over the 0.1–2 μM concentration range and with a detection limit of 10 nM. This method is simple, rapid, selective and sensitive. It may be applied to other small molecule analytes by applying appropriate aptamers. (author)

Specific Labeling of Zinc Finger Proteins using Non-canonical Amino Acids and Copper-free Click Chemistry

Science.gov (United States)

Kim, Younghoon; Kim, Sung Hoon; Ferracane, Dean; Katzenellenbogen, John A.

2012-01-01

Zinc finger proteins (ZFPs) play a key role in transcriptional regulation and serve as invaluable tools for gene modification and genetic engineering. Development of efficient strategies for labeling metalloproteins such as ZFPs is essential for understanding and controlling biological processes. In this work, we engineered ZFPs containing cysteine-histidine (Cys2-His2) motifs by metabolic incorporation of the unnatural amino acid azidohomoalanine (AHA), followed by specific protein labeling via click chemistry. We show that cyclooctyne promoted [3 + 2] dipolar cycloaddition with azides, known as copper-free click chemistry, provides rapid and specific labeling of ZFPs at high yields as determined by mass spectrometry analysis. We observe that the DNA-binding activity of ZFPs labeled by conventional copper-mediated click chemistry was completely abolished, whereas ZFPs labeled by copper-free click chemistry retain their sequence-specific DNA-binding activity under native conditions, as determined by electrophoretic mobility shift assays, protein microarrays and kinetic binding assays based on Förster resonance energy transfer (FRET). Our work provides a general framework to label metalloproteins such as ZFPs by metabolic incorporation of unnatural amino acids followed by copper-free click chemistry. PMID:22871171

Modification of liposomes with proteins by dansyl-labeled heterobifunctional crosslinker.

Science.gov (United States)

Chen, Tao; Wang, Rutao; Lu, Tingting; Liang, Guozheng; Lu, Tingli

2011-07-01

The introduction of a fluorescent chromaphore into bifunctional crosslinkers results in a molecule with normal crosslinker properties and a fluorescent group for straightforward quantification. This work describes the synthesis of the dansyl-labeled heterobifunctional crosslinker N-succinimidyl ε-N-dansyl α-N-(acetylthio)acetyllysine (dansyl-ATA-lysine-NHS) containing reactive N-hydroxysuccinimidyl (NHS) ester and sulfhydryl groups. The application of this crosslinker to conjugation of bovine serum albumin (BSA) protein to the surface of a liposome containing maleimide functions is also demonstrated. BSA was modified with the dansyl-labeled crosslinker and subsequently conjugated to liposomes containing reactive phospholipid derivative N-[4-(p-maleimidophenyl)butyryl]phosphatidylethanolamine and the degree of modification and conjugation were quantitatively determined by measuring the fluorescence emission of the dansyl group. The reliability of the fluorescence quantification was confirmed by a micro bio-barcode assay protein assay.

The effects of variations in the specificities of the antibody components on a two-site immunoradiometric assay for ferritin

International Nuclear Information System (INIS)

Cowan, S.I.; Stagg, B.H.; Niemann, E.

1977-01-01

Variations in the sub-unit antigenic structure of ferritins derived from various human tissues are reflected in the differing specificities of antisera raised against these ferritin preparations. In this study it was shown that antibody specificity played an important role in determining the sensitivity and overall binding of labelled antibody in a two-site immunoradiometric assay for ferritin. Homologous assay systems, in which solid phase and radiolabelled antibodies were of similar specificities, were generally less sensitive and showed lower binding than heterologous assay systems, in which solid phase and labelled antibodies were of different specificities. The source of the ferritin which was used as assay standard also played an important part in determining the sensitivity and overall binding in homologous antibody systems, spleen ferritin standards yielding assays superior to those obtained with placenta or liver ferritin standards. However, these differences between standards were not seen in a heterologous system employing solid phase antibodies directed against liver ferritin and labelled antibodies directed against placenta ferritin. The nature of the ferritin used to prepare immunoadsorbant for the purification of antibodies prior to radioiodination also affected the assay characteristics; antibodies prepared on spleen ferritin immunoadsorbant being more reactive than antibodies prepared on placenta ferritin immunoadsorbant, which in turn were more reactive then antibodies prepared on liver ferritin immunoadsorbant. (orig.) [de

Hyperoxygenated hydrogen-rich solution suppresses shock- and resuscitation-induced liver injury.

Science.gov (United States)

Dang, Yangjie; Liu, Ting; Mei, Xiaopeng; Meng, Xiangzhong; Gou, Xingchun; Deng, Bin; Xu, Hao; Xu, Lixian

2017-12-01

It is not known whether simultaneous delivery of hydrogen and oxygen can reduce injury caused by hemorrhagic shock and resuscitation (HSR). This study investigated the therapeutic potential of hyperoxygenated hydrogen-rich solution (HHOS), a combined hydrogen/oxygen carrier, in a rat model of HSR-induced liver injury. Rats (n = 60) were randomly divided into 5 groups (n = 6 per group at each time point). One group underwent sham operation, and the others were subjected to severe hemorrhagic shock and then treated with lactated Ringer's solution (LRS), hydrogen-rich solution, hyperoxygenated solution, or HHOS. At 2 and 6 h after resuscitation, blood samples (n = 6) were collected from the femoral artery and serum concentrations of alanine aminotransferase and aspartate aminotransferase (AST) were measured. Rats were then sacrificed, and histopathological changes in the liver were evaluated by quantifying the percentage of apoptotic cells by caspase-3 immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick-end labeling. Inflammation was assessed by assessing malondialdehyde content and tumor necrosis factor-α, and interleukin (IL)-6 expression. Compared to lactated Ringer's solution, hydrogen-rich solution, or hyperoxygenated solution groups, serum AST and alanine aminotransferase levels and IL-6, tumor necrosis factor-α, and malondialdehyde expression in liver tissue were decreased by HHOS treatment. The number of caspase-3- and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells was decreased (P < 0.05) by HHOS treatment, 2 and 6 h after resuscitation. HHOS has protective effects against liver injury in a rat model of HSR. Copyright © 2017 Elsevier Inc. All rights reserved.

Development and utilization of an ex vivo bromodeoxyuridine local lymph node assay protocol for assessing potential chemical sensitizers.

Science.gov (United States)

Williams, W C; Copeland, C; Boykin, E; Quell, S J; Lehmann, D M

2015-01-01

The murine local lymph node assay (LLNA) is widely used to identify chemicals that may cause allergic contact dermatitis. Exposure to a dermal sensitizer results in proliferation of local lymph node T cells, which has traditionally been measured by in vivo incorporation of [(3) H]methyl thymidine. A more recent non-isotopic variation of the assay utilizes bromodeoxyuridine (BrdU) incorporation in vivo. To further improve the utility of this assay, we developed an ex vivo BrdU labeling procedure eliminating the need for in vivo injections. The results of this assay correctly identified a strong sensitizer (i.e., trimellitic anhydride) as well as weak/moderate sensitizers (i.e., eugenol, cinnamaldehyde and hexylcinnaminic aldehyde). As anticipated, neither non-sensitizers isopropanol and lactic acid nor the false negative chemical nickel II sulfate hexahydrate induced a positive threshold response in the assay. The results of this assay are in close agreement with those of the in vivo LLNA:BrdU-enzyme-linked immunosorbent assay labeling procedure. We also used the ex vivo BrdU LLNA procedure to evaluate ammonium hexachloroplatinate, ammonium tetrachloroplatinate and cis-diamminedichloroplatinum(II) and the assay correctly identified them as sensitizers based on the calculation of EC2 values. We conclude that this ex vivo BrdU labeling method offers predictive capacity comparable to previously established LLNA protocols while eliminating animal injections and the use of radioisotope. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

N-(2-chloroethyl)-N-nitrosoureas covalently bound to nonionic and monocationic lexitropsin dipeptides. Synthesis, DNA affinity binding characteristics, and reactions with 32P-end-labeled DNA

International Nuclear Information System (INIS)

Church, K.M.; Wurdeman, R.L.; Zhang, Yi; Chen, Faxian; Gold, B.

1990-01-01

The synthesis and characterization of a series of compounds that contain an N-alkyl-N-nitrosourea functionality linked to DNA minor groove binding bi- and tripeptides (lexitropsins or information-reading peptides) based on methylpyrrole-2-carboxamide subunits are described. The lexitropsins (lex) synthesized have either a 3-(dimethylamino)propyl or propyl substituent on the carboxyl terminus. The preferred DNA affinity binding sequences of these compounds were footprinted in 32 P-end-labeled restriction fragments with methidiumpropyl-EDTA·Fe(II), and in common with other structural analogues, e.g., distamycin and netropsin, these nitrosoureas recognize A-T-rich runs. The affinity binding of the compound with the dimethylamino terminus, which is ionized at near-neutral pH, appeared stronger than that observed for the neutral dipeptide. The sequence specificity for DNA alkylation by (2-chloroethyl)nitrosourea-lex dipeptides (Cl-ENU-lex), with neutral and charged carboxyl termini, using 32 P-end-labeled restriction fragments, was determined by the conversion of the adducted sites into single-strand breaks by sequential heating at neutral pH and exposure to base. The DNA cleavage sites were visualized by polyacrylamide gel electrophoresis and autoradiography. Linking the Cl-ENU moiety to minor groove binders is a viable strategy to qualitatively and quantitatively control the delivery and release of the ultimate DNA alkylating agent in a sequence-dependent fashion

Radioimmunoassay for antigliadin-antibodies using 14C-labelled gliadin

International Nuclear Information System (INIS)

Menzel, J.

1977-01-01

A sensitive radioimmunoassay for antibodies to gliadin has been developed. Gliadin from wheat gluten was labelled with [1- 14 C]acetic anhydride to a specific activity of 2.6 x 10 6 dpm/mg. Immunological evidence is presented that the antigen was not essentially altered by the labelling procedure. Experimentally-induced antigliadin antibodies or sera of patients with coeliac disease (CD) were reacted with labelled gliadin and the immune complexes formed precipitated by antiglobulin. Precipitating antibodies were determined by incubating CD sera with labelled gliadin and measuring the radioacticity in precipitates formed without the addition of second antibody. Comparison with other methods for the detection of antigliadin antibodies, including immunoelectrophoresis, immunodiffusion and passive hemagglutination indicated that total and precipitating antibodies were determined only by RIA. The assay also provides information on the immunoglobulin class of antigliadin-antibodies present in sera of patients with coeliac disease

Surface-Enhanced Raman Scattering Nanoparticles as Optical Labels for Imaging Cell Surface Proteins

Science.gov (United States)

MacLaughlin, Christina M.

Assaying the expression of cell surface proteins has widespread application for characterizing cell type, developmental stage, and monitoring disease transformation. Immunophenotyping is conducted by treating cells with labelled targeting moieties that have high affinity for relevant surface protein(s). The sensitivity and specificity of immunophenotyping is defined by the choice of contrast agent and therefore, the number of resolvable signals that can be used to simultaneously label cells. Narrow band width surface-enhanced Raman scattering (SERS) nanoparticles are proposed as optical labels for multiplexed immunophenotying. Two types of surface coatings were investigated to passivate the gold nanoparticles, incorporate SERS functionality, and to facilitate attachment of targeting antibodies. Thiolated poly(ethylene glycol) forms dative bonds with the gold surface and is compatible with multiple physisorbed Raman-active reporter molecules. Ternary lipid bilayers are used to encapsulate the gold nanoparticles particles, and incorporate three different classes of Raman reporters. TEM, UV-Visible absorbance spectroscopy, DLS, and electrophoretic light scattering were used characterize the particle coating. Colourimetric protein assay, and secondary antibody labelling were used to quantify the antibody conjugation. Three different in vitromodels were used to investigate the binding efficacy and specificity of SERS labels for their biomarker targets. Primary human CLL cells, LY10 B lymphoma, and A549 adenocarcinoma lines were targeted. Dark field imaging was used to visualize the colocalization of SERS labels with cells, and evidence of receptor clustering was obtained based on colour shifts of the particles' Rayleigh scattering. Widefield, and spatially-resolved Raman spectra were used to detect labels singly, and in combination from labelled cells. Fluorescence flow cytometry was used to test the particles' binding specificity, and SERS from labelled cells was also

Washing-free heterogeneous immunosensor using proximity-dependent electron mediation between an enzyme label and an electrode.

Science.gov (United States)

Dutta, Gorachand; Kim, Sinyoung; Park, Seonhwa; Yang, Haesik

2014-05-06

Washing processes, essential in most heterogeneous labeled assays, have been a big hurdle in simplifying the detection procedure and reducing assay time. Nevertheless, less attention has been paid to washing-free heterogeneous labeled assays. We report a purely washing-free immunosensor that allows fast, sensitive, and single-step detection of prostate-specific antigen in serum with low interference. Proximity-dependent electron mediation of ferrocenemethanol (Fc) between an indium-tin oxide (ITO) electrode and a glucose-oxidase (GOx) label allows us to discriminate between a bound and an unbound label: a bound label offers faster electron mediation than an unbound one. The electrooxidation of Fc at a low applied potential (0.13 V vs Ag/AgCl) and a low electrocatalytic ITO electrode and the oxidation of l-ascorbic acid by l-ascorbate oxidase minimize the effect of the interfering species. With a high concentration of glucose (200 mM), the signal and background levels are hardly dependent on the glucose-concentration variation in the sample. The washing-free immunosensor can detect a concentration of ca. 1 pg/mL for mouse IgG in phosphate-buffered saline and a concentration of ca. 10 pg/mL for prostate-specific antigen spiked in female serum after an incubation period of 10 min. The concentrations measured with actual clinical serum samples are in good agreement with the concentrations measured with a commercial instrument, which renders the washing-free heterogeneous immunosensor appealing for practical use.

Diagnosis of selected tropical diseases (Shistosomiasis and Malaria) using the enzyme-linked immunosorbent assays

International Nuclear Information System (INIS)

Chembe, E.

1985-01-01

Immunological reactions are commonly used in diagnostic procedures on the basis of their high levels of specificity and sensitivity. Antibodies or antigens labelled with various markers have been found to be particularly useful for assays of logical substances. The applications of Enzyme-Linked Immunoabsorbent Assays (ELISA) to research on various tropical and non-tropical diseases is now well established. The procedure depends on the labelling of one of the reactants with enzymes which can be detected accurately by an appropriate substrate. The detection mechanism depends on the labelling of one of the reactants in such a way that their their reactivity is not impaired or affected. In the present study, ELISA was applied to sera from kampumbu area of Isoka district in the Northern province of Zambia. The objective of this presentation is to show the relative positivity rate for antigen and antibody and the endemicity of schistosomiasis and malaria as assessed by classical parasitological procedures. (author)

Curcumin ameliorates cardiac dysfunction induced by mechanical trauma.

Science.gov (United States)

Li, Xintao; Cao, Tingting; Ma, Shuo; Jing, Zehao; Bi, Yue; Zhou, Jicheng; Chen, Chong; Yu, Deqin; Zhu, Liang; Li, Shuzhuang

2017-11-05

Curcumin, a phytochemical component derived from turmeric (Carcuma longa), has been extensively investigated because of its anti-inflammatory and anti-oxidative properties. Inflammation and oxidative stress play critical roles in posttraumatic cardiomyocyte apoptosis, which contributes to secondary cardiac dysfunction. This research was designed to identify the protective effect of curcumin on posttraumatic cardiac dysfunction and investigate its underlying mechanism. Noble-Collip drum was used to prepare a mechanical trauma (MT) model of rats, and the hemodynamic responses of traumatized rats were observed by ventricular intubation 12h after trauma. Myocardial apoptosis was determined through terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and caspase-3 activity assay. Tumor necrosis factor-α (TNF-α) and reactive oxygen species (ROS) generated by monocytes and myocardial cells were identified through enzyme-linked immunosorbent assay (ELISA), and the intracellular alteration of Ca 2+ in cardiomyocytes was examined through confocal microscopy. In vivo, curcumin effectively ameliorated MT-induced secondary cardiac dysfunction and significantly decreased the apoptotic indices of the traumatized myocardial cells. In vitro, curcumin inhibited TNF-α production by monocytes and reduced the circulating TNF-α levels. With curcumin pretreatment, ROS production and Ca 2+ overload in H9c2 cells were attenuated when these cells were incubated with traumatic plasma. Therefore, curcumin can effectively ameliorate MT-induced cardiac dysfunction mainly by inhibiting systemic inflammatory responses and by weakening oxidative stress reaction and Ca 2+ overload in cardiomyocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

Inhibition of miR-155 Protects Against LPS-induced Cardiac Dysfunction and Apoptosis in Mice

Directory of Open Access Journals (Sweden)

Hui Wang

2016-01-01

Full Text Available Sepsis-induced myocardial dysfunction represents a major cause of death in intensive care units. Dysregulated microRNAs (miR-155 has been implicated in multiple cardiovascular diseases and miR-155 can be induced by lipopolysaccharide (LPS. However, the role of miR-155 in LPS-induced cardiac dysfunction is unclear. Septic cardiac dysfunction in mice was induced by intraperitoneal injection of LPS (5 mg/kg and miR-155 was found to be significantly increased in heart challenged with LPS. Pharmacological inhibition of miR-155 using antagomiR improved cardiac function and suppressed cardiac apoptosis induced by LPS in mice as determined by echocardiography, terminal deoxynucleotidyl transferase nick-end labeling (TUNEL assay, and Western blot for Bax and Bcl-2, while overexpression of miR-155 using agomiR had inverse effects. Pea15a was identified as a target gene of miR-155, mediating its effects in controlling apoptosis of cardiomyocytes as evidenced by luciferase reporter assays, quantitative real time-polymerase chain reaction, Western blot, and TUNEL staining. Noteworthy, miR-155 was also found to be upregulated in the plasma of patients with septic cardiac dysfunction compared to sepsis patients without cardiac dysfunction, indicating a potential clinical relevance of miR-155. The receiver-operator characteristic curve indicated that plasma miR-155 might be a biomarker for sepsis patients developing cardiac dysfunction. Therefore, inhibition of miR-155 represents a novel therapy for septic myocardial dysfunction.

Ganoderma tsugae Hepatoprotection against Exhaustive Exercise-Induced Liver Injury in Rats

Directory of Open Access Journals (Sweden)

Wan-Teng Lin

2013-01-01

Full Text Available Several studies have been shown that accelerated apoptosis is involved in post-exercise lymphocytopenia and tissue damage after high-intensity exercise. Ganoderma tsugae (GT is one of the well-known medicinal mushrooms that possess various pharmacological functions. This mushroom has traditionally been used for health promotion purposes. This study investigates the hepatoprotective effects of GT on exhaustive exercise-induced liver damage. Twenty-four male Sprague-Dawley rats were randomly divided into four groups and designated as exhaustive exercise only (E, exhaustive exercise with low dosage (EL, medium dosage (EM and high dosage (EH GT at 0, 0.1875, 0.9375 and 1.875 g/kg/day, respectively. After 30 days all rats were euthanized immediately after an exhaustive running challenge on a motorized treadmill. The rat livers were immediately harvested. Evidence of apoptotic liver cell death was revealed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay and caspases mediated cascade events. DNA fragmentation, an apoptosis process, can be examined using TUNEL assay. A few TUNEL-positive hepatocytes, compared to the exercise only group, were observed in the livers from exhaustive animals supplemented with GT. Immunoblot analysis also showed that caspase-6-mediated specific cleavage of lamin A/C was increased significantly in the livers of group E, but was significantly decreased in the EM and EH groups. Our observations demonstrate that GT possesses anti-apoptotic and hepatoprotective potential after exhaustive exercise.

Ganoderma tsugae hepatoprotection against exhaustive exercise-induced liver injury in rats.

Science.gov (United States)

Huang, Chi-Chang; Huang, Wen-Ching; Yang, Suh-Ching; Chan, Chih-Chi; Lin, Wan-Teng

2013-01-29

Several studies have been shown that accelerated apoptosis is involved in post-exercise lymphocytopenia and tissue damage after high-intensity exercise. Ganoderma tsugae (GT) is one of the well-known medicinal mushrooms that possess various pharmacological functions. This mushroom has traditionally been used for health promotion purposes. This study investigates the hepatoprotective effects of GT on exhaustive exercise-induced liver damage. Twenty-four male Sprague-Dawley rats were randomly divided into four groups and designated as exhaustive exercise only (E), exhaustive exercise with low dosage (EL), medium dosage (EM) and high dosage (EH) GT at 0, 0.1875, 0.9375 and 1.875 g/kg/day, respectively. After 30 days all rats were euthanized immediately after an exhaustive running challenge on a motorized treadmill. The rat livers were immediately harvested. Evidence of apoptotic liver cell death was revealed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and caspases mediated cascade events. DNA fragmentation, an apoptosis process, can be examined using TUNEL assay. A few TUNEL-positive hepatocytes, compared to the exercise only group, were observed in the livers from exhaustive animals supplemented with GT. Immunoblot analysis also showed that caspase-6-mediated specific cleavage of lamin A/C was increased significantly in the livers of group E, but was significantly decreased in the EM and EH groups. Our observations demonstrate that GT possesses anti-apoptotic and hepatoprotective potential after exhaustive exercise.

Limitations of the radioimmunoprecipitation polyethylene glycol assay (RIPEGA) for detection of filarial antigens in serum

International Nuclear Information System (INIS)

Hamilton, R.G.; Alexander, E.; Adkinson, N.F.

1984-01-01

The performance of the radioimmunoprecipitation polyethylene glycol assay (RIPEGA) was examined for quantitation of filarial antigens (Brugia malayi and Dirofilaria immitis) in serum from infected human and animal hosts and non-infected controls. Multiple PEG concentrations were employed to determine the level of non-specific binding (NSB) in non-exposed human sera (NEHS) containing no filarial antigen. The NSB observed when 3 different 125 I-labelled IgG antibodies were added to 26 NEHS varied 3-fold and was correlated significantly with total serum IgM (r = 0.80, P 2 fragment of the 125 I-labelled antibody was used, but the correlation of NSB with total serum IgM remained significant (r = 0.57, P < 0.01). The presence of rheumatoid factor in NEHS sera also significantly increased NSB by an average of 3-fold. These effects eliminated the assay's ability to detect in sera from infected hosts filarial antigen the presence of which could be readily demonstrated by an immunoradiometric assay. The RIPEGA's precision (intra-assay coefficient of variation (CV) = 21% at 35% Bsub(max)) and reproducibility (inter-assay CV = 29% at 35% Bsub(max)) are less satisfactory than many alternative immunoassays. (Auth.)

New fluorimetric assay of horseradish peroxidase using sesamol as substrate and its application to EIA

Directory of Open Access Journals (Sweden)

Hidetoshi Arakawa

2012-04-01

Full Text Available Horseradish peroxidase (HRP is generally used as a label enzyme in enzyme immunoassay (EIA. The procedure used for HRP detection in EIA is critical for sensitivity and precision. This paper describes a novel fluorimetric assay for horseradish peroxidase (HRP using sesamol as substrate. The principle of the assay is as follow: sesamol (3,4-methylenedioxy phenol is reacted enzymatically in the presence of hydrogen peroxide to produce dimeric sesamol. The dimer is fluorescent and can be detected sensitively at ex. 347 nm, em. 427 nm.The measurable range of HRP was 1.0×10−18 to 1.0×10−15 mol/assay, with a detection limit of 1.0×10−18 mol/assay. The coefficient of variation (CV, n=8 was examined at each point on the standard curve, with a mean CV percentage of 3.8%. This assay system was applied to thyroid stimulating hormone (TSH EIA using HRP as the label enzyme. Keywords: Sesamol, Fluorescence, Enzyme immunoassay (EIA, Horseradish peroxidase (HRP, Thyroid stimulating hormone (TSH

Quantitative localization microscopy: effects of photophysics and labeling stoichiometry.

Directory of Open Access Journals (Sweden)

Robert P J Nieuwenhuizen

Full Text Available Quantification in localization microscopy with reversibly switchable fluorophores is severely hampered by the unknown number of switching cycles a fluorophore undergoes and the unknown stoichiometry of fluorophores on a marker such as an antibody. We overcome this problem by measuring the average number of localizations per fluorophore, or generally per fluorescently labeled site from the build-up of spatial image correlation during acquisition. To this end we employ a model for the interplay between the statistics of activation, bleaching, and labeling stoichiometry. We validated our method using single fluorophore labeled DNA oligomers and multiple-labeled neutravidin tetramers where we find a counting error of less than 17% without any calibration of transition rates. Furthermore, we demonstrated our quantification method on nanobody- and antibody-labeled biological specimens.

Bovine viral diarrhea virus: molecular cloning of genomic RNA and its diagnostic application

International Nuclear Information System (INIS)

Brock, K.V.

1987-01-01

Molecular cloning of a field isolate of bovine viral diarrhea virus (BVDV) strain 72 RNA was done in this study. The sensitivity and specificity of cloned cDNA sequences in hybridization assays with various BVDV strains were determined. cDNA was synthesized from polyadenylated BVDV RNA templates with oligo-dT primers, reverse transcriptase, and DNA polymerase I. The newly synthesized double-stranded BVDV cDNA was C-tailed with terminal deoxytransferase and annealed into G-tailed, Pst-1-cut pUC9 plasmid. Escherichia coli was transformed with the recombinant plasmids and a library of approximately 200 BVDV specific cDNA clones varying in length from 0.5 to 2.6 kilobases were isolated. The sensitivity and specificity of hybridization between the labelled cDNA and BVDV target sequences were determined. Cloned BVDV sequences were isolated from pUC9 plasmid DNA and labelled with 32 P by nick translation. The detection limit by dot blot hybridization assay was 20 pg of purified genomic BVDV RNA. cDNA hybridization probes were specific for all strains of BVDV tested, regardless of whether they were noncytopathic and cytopathic, but did not hybridize with heterologous bovine viruses tested. Probes did not hybridize with uninfected cell culture or cellular RNA. Hybridization probes were at least as sensitive as infectivity assays in detecting homologous virus

Neutron Resonance Transmission Analysis (NRTA): A Nondestructive Assay Technique for the Next Generation Safeguards Initiative’s Plutonium Assay Challenge

Energy Technology Data Exchange (ETDEWEB)

J. W. Sterbentz; D. L. Chichester

2010-12-01

This is an end-of-year report for a project funded by the National Nuclear Security Administration's Office of Nuclear Safeguards (NA-241). The goal of this project is to investigate the feasibility of using Neutron Resonance Transmission Analysis (NRTA) to assay plutonium in commercial light-water-reactor spent fuel. This project is part of a larger research effort within the Next-Generation Safeguards Initiative (NGSI) to evaluate methods for assaying plutonium in spent fuel, the Plutonium Assay Challenge. The first-year goals for this project were modest and included: 1) developing a zero-order MCNP model for the NRTA technique, simulating data results presented in the literature, 2) completing a preliminary set of studies investigating important design and performance characteristics for the NRTA measurement technique, and 3) documentation of this work in an end of the year report (this report). Research teams at Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL), Pacific Northwest National Laboratory (PNNL), and at several universities are also working to investigate plutonium assay methods for spent-fuel safeguards. While the NRTA technique is well proven in the scientific literature for assaying individual spent fuel pins, it is a newcomer to the current NGSI efforts studying Pu assay method techniques having just started in March 2010; several analytical techniques have been under investigation within this program for two to three years or more. This report summarizes a nine month period of work.

Renal cell apoptosis in human lupus nephritis: a histological study

DEFF Research Database (Denmark)

Faurschou, M; Penkowa, Milena; Andersen, C B

2009-01-01

Nuclear autoantigens from apoptotic cells are believed to drive the immunological response in systemic lupus erythematosus (SLE). Conflicting data exist as to the possible renal origin of apoptotic cells in SLE patients with nephritis. We assessed the level of renal cell apoptosis in kidney...... biopsies from 35 patients with lupus nephritis by means of terminal deoxynucleotidyl-transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-digoxigenin nick end labeling (TUNEL). Five samples of normal kidney tissue served as control specimens. We did not observe apoptotic glomerular cells in any...... cells constitute a quantitatively important source of auto-antibody-inducing nuclear auto-antigens in human lupus nephritis....

Study of radionuclide 90Sr-90Y on cell proliferation and apoptosis in benign prostatic hyperplasia

International Nuclear Information System (INIS)

Zhang Tong; Wei Wei; Zou Benjie; Liu Fang; Xu Zhishun

2003-01-01

Objective: To investigate the effect of 90 Sr- 90 Yon cell proliferation and apoptosis in benign prostatic hyperplasia. Methods: The apoptosis and expression of Ki-67 in benign prostatic hyperplasia (BPH) before and after irradiation 90 Sr- 90 Y were detected by transferase-mediated dUTP-biotin nick end labeling (TUNEL) method and immunohistochemical technique, respectively. Results: The proliferation index (PI) of BPH after 90 Sr- 90 Y irradiation was much lower than that before irradiation, but there was no significant change in apoptosis index (AI). Conclusion: Irradiation with 90 Sr- 90 Y could restrain cell proliferation of BPH, but could not induce apoptosis

Synthesis of 14C and 32P double labelled triethylphosphine

International Nuclear Information System (INIS)

Kanska, M.; Drabarek, S.

1979-01-01

The synthesis of 14 C and 32 P double labelled triethylphosphine has been carried out using red phosphorus [ 32 P] and barium carbonate [ 14 C] as starting materials. The product of the reaction has been separated by gas chromatography. The 32 P radioactivity assay of the obtained product was performed by the liquid scintillation technique. The 14 C radioactivity was determined by the liquid scintillation technique and internal gas counting method. The radioactivity measurements have served to determine the total yield of double labelled triethylphosphine. (author)

Branched-DNA signal amplification combined with paper chromatography hybridization assay and used in hepatitis B virus DNA detection

International Nuclear Information System (INIS)

Fu, F.Z.; Liu, L.X.; Wang, W.Q.; Sun, S. H.; Liu, L.B.

2002-01-01

Nucleic acids detection method is vital to the clinical pathogen diagnosis. The established method can be classified into target direct amplification and signal amplification format according to the target DNA or RNA being directly amplified or not. Those methods have advantages and disadvantages respectively in the clinical application. In the United States of American, branched-DNA as a strong signal amplifier is broadly used in the quantification of the nucleic acids. To gain satisfied sensitivity, some expensive label molecular and instruments should be adopted. Personnel should be special trained to perform. Hence, those can't be widely carried out in the Third World. To avoid those disadvantages, we used the branched-DNA amplifier in the paper chromatography hybridization assay. Methods: Branched DNA signal amplifier and series of probes complementary to the nucleic acid sequence of hepatitis B virus (HBV) have been synthesized. HBV-DNA or it's capture probe were immobilized on the high flow nitrocellulose strip. Having loaded at one end of the strip in turn, probes or HBV-DNA in the hybridization solution migrate to the opposite end of the strip by capillary forces and hybridizes to the immobilized DNA. The branched-DNA signal amplifier and probe labeled with biotin or 32P were then loaded. Through streptavidin-alkaline phosphatase (SA-AP) conjugate and NBT/BCIP ( the specific chromogenic substrate of AP) or autoradiography, the result can be visualized by color reaction or image production on the X-ray film. Results: The sensitivity of this HBV-DNA detection method used probe labeled with biotin and 32P are 1ng and 10pg. The method using the probe labeled with biotin is simple and rapid (2h) without depending on special instruments, it also avoids the pollution of EtBr which can lead to tumor. And the method using the probe labeled with 32P is simple and sensitive, with the exception of long time autoradiography and the inconvenient isotopic disposal

Dual-Quantum-Dots-Labeled Lateral Flow Strip Rapidly Quantifies Procalcitonin and C-reactive Protein

Science.gov (United States)

Qi, XiaoPing; Huang, YunYe; Lin, ZhongShi; Xu, Liang; Yu, Hao

2016-03-01

In the article, a dual-quantum-dots-labeled (dual-QDs-labeled) lateral flow strip (LFS) method was developed for the simultaneous and rapid quantitative detection of procalcitonin (PCT) and C-reactive protein (CRP) in the blood. Two QD-antibody conjugates with different fluorescence emission spectra were produced and sprayed on the LFS to capture PCT and CRP in the blood. Furthermore, a double antibody sandwich method for PCT and, meanwhile, a competitive inhibition method for CRP were employed in the LFS. For PCT and CRP in serum assayed by the dual-QDs-labeled LFS, their detection sensitivities reached 0.1 and 1 ng/mL, respectively, and their linear quantitative detection ranges were from 0.3 to 200 ng/mL and from 50 to 250 μg/mL, respectively. There was little evidence that the PCT and CRP assays would be interfered with each other. The correlations for testing CRP and PCT in clinical samples were 99.75 and 97.02 %, respectively, between the dual-QDs-labeled LFS we developed and commercial methods. The rapid quantification of PCT and CRP on dual-QDs-labeled LFS is of great clinical value to distinguish inflammation, bacterial infection, or viral infection and to provide guidance for the use of antibiotics or other medicines.

A sensitive competitive binding assay for exogenous and endogenous heparins

International Nuclear Information System (INIS)

Dawes, J.; Pepper, D.S.

1982-01-01

A new type of assay for heparins has been devised, in which the test material competes with 125 I-labelled heparin for binding to protamine-Sepharose. The assay is very sensitive and will measure heparin concentrations down to 10 ng ml-1. It responds to both the degree of sulphation and the molecular weight of acidic polysaccharides, but is independent of their biological activities. It can be used to quantitate heparins in biological fluids after pretreatment of the samples with protease. In this way endogenous heparins were measured in normal human serum, plasma and urine. The assay is extremely versatile and has great potential for the investigation of endogenous and exogenous heparins

Phosphine reduced IgG. A new method for {sup 99m}Tc labeling immunoglobulins

Energy Technology Data Exchange (ETDEWEB)

Arteaga de Murphy, C; Melendez-Alafort, L [Radiofarmacia Departamento de Medicina Nuclear, Instituto Nacional de Nutricion Salvador Zubiran, Mexico (Mexico); Martinez-Rivero, O [Laboratorio de Quimica Organica, Facultad de Quimica, Universidad de la Habana, Habana (Cuba); Gomez, E [Departamento de Fisiologia de la Nutricion, Instituto Nacional de Nutricion Salvador Zubiran, Mexico (Mexico); Ferro-Flores, G [Depeartamento del Reactor y Materiales Radioactivos, Instituto Nacional de Investigaciones Nucleares, Mexico (Mexico)

1997-09-01

A new technetium labeling method for immunoglobulins reduced with tris(2-carboxy-ethyl)phosphine hydrochloride is presented. The Sandoglobulina IgG source was assayed for purity and optimum reagent`s concentration and incubation times were determined. It was purified by column chromatography and labelled with Sn{sup 2+} reduced technetium in the presence of MDP. The kit is easy to prepare, labeling efficiency is >(97{+-}1.9)% and stable for 6 hours.The immunoreactivity of the {sup 99}Tc-IgG was verified by electrophoresis and Western blot tests. The IgG retained its structure after both the reducing and labeling processes and it was the only labeled species. (author). 11 refs.

Ior-CEA-1: Labelling, quality control and clinical evaluation

International Nuclear Information System (INIS)

Pimentel, G.J.

1998-01-01

Within the Co-ordinated Programme on Labelling, Quality Control and Evaluation of Monoclonal Antibodies, the IAEA has made a great effort to expand efficient labelling methods, mainly those with radioisotopes which have been used for radioimmunoscintigraphy. In this sense, more recently 99 Tc m has been mostly employed in the majority of the investigations due to its ideal physical characteristics. Efficient labelling of monoclonal antibodies depends on a number of factors including the method and way of the label incorporation into the protein. During the last years several direct labelling approaches have been developed, which led to attain simple and inexpensive methods for medical practice, as well as safe and stable techniques which bring accurate and good quality images. Accordingly, this paper describes the results obtained during last five years which come from the comparison among different labelling systems, passing through the quality control to test the labelled monoclonal stability and the protein bioreactivity, to continue in the clinical evaluation of ior-CEA-1, as well as the evaluation of other antibodies. Up to now we have evaluated more than 70 patients with the anti-CEA monoclonal antibody (ior-CEA-1), examined in different clinical assays such as: pilot, phase I-II and extensive phase III-IV trials, whose results are encouraging. It confirms that the employed labelling approach was safe and adequate

Quantification of isotope-labelled and unlabelled folates in plasma, ileostomy and food samples.

Science.gov (United States)

Büttner, Barbara E; Öhrvik, Veronica E; Witthöft, Cornelia M; Rychlik, Michael

2011-01-01

New stable isotope dilution assays were developed for the simultaneous quantitation of [(13)C(5)]-labelled and unlabelled 5-methyltetrahydrofolic acid, 5-formyltetrahydrofolic acid, folic acid along with unlabelled tetrahydrofolic acid and 10-formylfolic acid in clinical samples deriving from human bioavailability studies, i.e. plasma, ileostomy samples, and food. The methods were based on clean-up by strong anion exchange followed by LC-MS/MS detection. Deuterated analogues of the folates were applied as the internal standards in the stable isotope dilution assays. Assay sensitivity was sufficient to detect all relevant folates in the respective samples as their limits of detection were below 0.62 nmol/L in plasma and below 0.73 μg/100 g in food or ileostomy samples. Quantification of the [(13)C(5)]-label in clinical samples offers the possibility to differentiate between folate from endogenous body pools and the administered dose when executing bioavailability trials.

Leishmanicidal activities of Artemisia annua leaf essential oil against Visceral Leishmaniasis

Directory of Open Access Journals (Sweden)

Mohammad eIslamuddin

2014-11-01

Full Text Available Visceral leishmaniasis (VL, the second-most dreaded parasitic disease after malaria, is currently endemic in 88 countries. Dramatic increases in the rates of infection, drug resistance and non-availability of safe vaccines have highlighted the need for identification of novel and inexpensive anti-leishmanial agents from natural sources. In this study, we showed the leishmanicidal effect of essential oil from Artemisia annua leaves (AALEO against Leishmania donovani in vitro and in vivo. AALEO was extracted by hydrodistillation and characterized by GC-MS, the most abundant compounds were found to be camphor (52.06 % followed by β-caryophyllene (10.95 %. AALEO exhibited significant leishmanicidal activity against L. donovani, with 50 % inhibitory concentration of 14.63 ± 1.49 µg ml-1 and 7.3 ± 1.85 µg ml─1, respectively, against the promastigotes and intracellular amastigotes. The effect was mediated through programmed cell death as confirmed by externalization of phosphatidylserine, DNA nicking by TdT-mediated dUTP nick-end labelling (TUNEL assay, dyskinetoplastidy, cell cycle arrest at sub-G0–G1 phase, loss of mitochondrial membrane potential and reactive oxygen species (ROS generation in promastigotes and nitric oxide (NO generation in ex vivo model. AALEO presented no cytotoxic effects against mammalian macrophages even at 200 µg ml─1. Intra-peritoneal administration of AALEO (200 mg/ kg.b.w. to infected BALB/c mice reduced the parasite burden by almost 90 % in the liver and spleen with significant reduction in weight. There was no hepato- or nephro-toxicity as demonstrated by normal levels of serum enzymes. The promising antileishmanial activity shown by camphor-rich AALEO may provide a new lead in the treatment of VL.

Evidence for alternative pathways of granulosa cell death in healthy and slightly atretic bovine antral follicles.

Science.gov (United States)

Van Wezel, I L; Dharmarajan, A M; Lavranos, T C; Rodgers, R J

1999-06-01

Granulosa cell death is an early feature of atresia; however, there are many apparent contradictions in the literature concerning the mode of granulosa cell death. We have therefore examined this process in bovine healthy and atretic antral follicles, using a variety of established techniques. Light and electron microscopic observations indicated the presence of pyknotic or shrunken nuclei in both the membrana granulosa and the antrum. In the membrana granulosa, these nuclei were frequently crescent shaped and uniformly electron dense and were approximately the same size as healthy nuclei, all of which are typical of early apoptosis. However, these nuclei were within the membranes of a healthy granulosa cell, suggesting that phagocytosis by a neighboring granulosa cell is an unusually early event in the apoptotic pathway of granulosa cells. In the membrana granulosa, pyknotic nuclei stained intensely with hematoxylin but weakly with the DNA-intercalating stain propidium iodide. A percentage of these pyknotic nuclei stained by TUNEL (terminal deoxy-UTP nick end-labeling). However, in the antrum, the pyknotic nuclei and larger globules of DNA stained intensely with both hematoxylin and propidium iodide, but were not TUNEL positive. The comet assay of cell death produced a streak tail of randomly nicked DNA, rather than the plume of low mol wt apoptotic DNA. Globules collected from fresh follicular fluid stained intensely with propidium iodide and were shown by PAGE to contain DNA, the majority of which was high mol wt. In conclusion, granulosa cells within the membrana granulosa die by apoptosis, with phagocytosis by a neighboring cell preceding any potential budding of the nucleus or cell itself. Granulosa cells near the antrum are sloughed off into the antrum, and their death has features more consistent with that of other cell types that undergo death as a result of terminal differentiation.

Sensitive radiometric assay for enkephalin convertase and other carboxypeptidase B-like enzymes

International Nuclear Information System (INIS)

Stack, G.; Fricker, L.D.; Snyder, S.H.

1984-01-01

A sensitive radiometric assay for carboxypeptidase B-like enzymes has been developed using enkephalin convertase, an enkephalin synthesizing carboxypeptidase. The assay is based on the differential solubility of 3 H-labeled substrate and product in chloroform. The substrates 3 H-benzoyl-Phe-Ala-Arg or 3 H-benzoyl-Phe-Leu-Arg are poorly soluble in chloroform due to the charged arginine. The products of carboxypeptidase B-like activity on these substrates, 3 H-benzoyl-Phe-Ala or 3 H-benzoyl Phe-Leu partition quantitatively into chloroform, allowing rapid separation of product from substrate. This assay is approximately 100 times more sensitive than a similar fluorometric assay utilizing dansyl-Phe-Ala-Arg as a substrate

Sensitive radiometric assay for enkephalin convertase and other carboxypeptidase B-like enzymes

Energy Technology Data Exchange (ETDEWEB)

Stack, G.; Fricker, L.D.; Snyder, S.H.

1984-01-09

A sensitive radiometric assay for carboxypeptidase B-like enzymes has been developed using enkephalin convertase, an enkephalin synthesizing carboxypeptidase. The assay is based on the differential solubility of /sup 3/H-labeled substrate and product in chloroform. The substrates /sup 3/H-benzoyl-Phe-Ala-Arg or /sup 3/H-benzoyl-Phe-Leu-Arg are poorly soluble in chloroform due to the charged arginine. The products of carboxypeptidase B-like activity on these substrates, /sup 3/H-benzoyl-Phe-Ala or /sup 3/H-benzoyl Phe-Leu partition quantitatively into chloroform, allowing rapid separation of product from substrate. This assay is approximately 100 times more sensitive than a similar fluorometric assay utilizing dansyl-Phe-Ala-Arg as a substrate.

Detection of chitinase activity by 2-aminobenzoic acid labeling of chito-oligosaccharides.

Science.gov (United States)

Ghauharali-van der Vlugt, Karen; Bussink, Anton P; Groener, Johanna E M; Boot, Rolf G; Aerts, Johannes M F G

2009-01-01

Chitinases are hydrolases capable of hydrolyzing the abundant natural polysaccharide chitin. Next to artificial fluorescent substrates, more physiological chito-oligomers are commonly used in chitinase assays. Analysis of chito-oligosaccharides products is generally accomplished by UV detection. However, the relatively poor sensitivity poses a serious limitation. Here we report on a novel, much more sensitive assay for the detection of chito-oligosaccharide reaction products released by chitinases, based on fluorescent detection, following chemical labeling by 2-aminobenzoic acid. Comparison with existing UV-based assays, shows that the novel assay offers the same advantages yet allows detection of chito-oligosaccharides in the low picomolar range.

Learning from Weak and Noisy Labels for Semantic Segmentation

KAUST Repository

Lu, Zhiwu

2016-04-08

A weakly supervised semantic segmentation (WSSS) method aims to learn a segmentation model from weak (image-level) as opposed to strong (pixel-level) labels. By avoiding the tedious pixel-level annotation process, it can exploit the unlimited supply of user-tagged images from media-sharing sites such as Flickr for large scale applications. However, these ‘free’ tags/labels are often noisy and few existing works address the problem of learning with both weak and noisy labels. In this work, we cast the WSSS problem into a label noise reduction problem. Specifically, after segmenting each image into a set of superpixels, the weak and potentially noisy image-level labels are propagated to the superpixel level resulting in highly noisy labels; the key to semantic segmentation is thus to identify and correct the superpixel noisy labels. To this end, a novel L1-optimisation based sparse learning model is formulated to directly and explicitly detect noisy labels. To solve the L1-optimisation problem, we further develop an efficient learning algorithm by introducing an intermediate labelling variable. Extensive experiments on three benchmark datasets show that our method yields state-of-the-art results given noise-free labels, whilst significantly outperforming the existing methods when the weak labels are also noisy.

Learning from Weak and Noisy Labels for Semantic Segmentation

KAUST Repository

Lu, Zhiwu; Fu, Zhenyong; Xiang, Tao; Han, Peng; Wang, Liwei; Gao, Xin

2016-01-01

A weakly supervised semantic segmentation (WSSS) method aims to learn a segmentation model from weak (image-level) as opposed to strong (pixel-level) labels. By avoiding the tedious pixel-level annotation process, it can exploit the unlimited supply of user-tagged images from media-sharing sites such as Flickr for large scale applications. However, these ‘free’ tags/labels are often noisy and few existing works address the problem of learning with both weak and noisy labels. In this work, we cast the WSSS problem into a label noise reduction problem. Specifically, after segmenting each image into a set of superpixels, the weak and potentially noisy image-level labels are propagated to the superpixel level resulting in highly noisy labels; the key to semantic segmentation is thus to identify and correct the superpixel noisy labels. To this end, a novel L1-optimisation based sparse learning model is formulated to directly and explicitly detect noisy labels. To solve the L1-optimisation problem, we further develop an efficient learning algorithm by introducing an intermediate labelling variable. Extensive experiments on three benchmark datasets show that our method yields state-of-the-art results given noise-free labels, whilst significantly outperforming the existing methods when the weak labels are also noisy.

Active site labeling of the guanine-7-methyltransferase

International Nuclear Information System (INIS)

Streaker, E.; Sitz, T.O.

1992-01-01

Studies on the guanine-7-methyltransferase have defined three domains in the active site: the S-adenosylmethionine (SAM) region, the cap region (GpppG), and the RNA binding domain (--NpNpNpNpNp---). The authors attempted to label the SAM binding domain by a photoaffinity label using 8-azido-SAM and another method using 3 H-SAM and long exposures to uv-light. Neither method was successful. The next approach was to attempt to label the cap-RNA binding domain (GpppGpNpNpNpNpN) by synthesizing RNA containing 8-azido-Ap using an in vitro transcription system and T7 RNA polymerase. The 8-azido-ATP inhibited the T7 RNA polymerase preventing the synthesis of RNA. As they were unable to synthesize the photoaffinity label, they next tried to synthesize an end labeled RNA and directly label by long exposures to uv-light. When the enzyme was incubated with 32 P-labeled RNA for 15 min at 37 degrees and then exposed to a germicidal lamp for various times at O degrees, optimal labeling occurred after 45 min. Various enzyme preparations were labeled by this method and two polypeptides were found to specifically bind the non-methylated mRNA analog. This labeling method should allow characterization of the subunit structure and generate information about the nature of the RNA binding domain

Azadioxatriangulenium (ADOTA+): A long fluorescence lifetime fluorophore for large biomolecule binding assay

Science.gov (United States)

Sørensen, Thomas Just; Thyrhaug, Erling; Szabelski, Mariusz; Luchowski, Rafal; Gryczynski, Ignacy; Gryczynski, Zygmunt; Laursen, Bo W.

2013-01-01

Of the many optical bioassays available, sensing by fluorescence anisotropy have great advantages as it provides a sensitive, instrumentally simple, ratiometric method of detection. However, it is hampered by a severe limitation as the emission lifetime of the label needs to be comparable to the correlation lifetime (tumbling time) of the biomolecule which is labelled. For proteins of moderate size this is in the order of 20–200 ns, which due to practical issues currently limits the choice of labels to the dansyl-type dyes and certain aromatics dyes. These have the significant drawback of UV/blue absorption and emission as well as an often significant solvent sensitivity. Here, we report the synthesis and characterization of a new fluorescent label for high molecular weight biomolecules assay based on the azadioxatriangulenium motif. The NHS ester of the long fluorescence lifetime, red emitting fluorophore: azadioxatriangulenium (ADOTA-NHS) was conjugated to anti-rabbit Immunoglobulin G (antiIgG). The long fluorescence lifetime was exploited to determine the correlation time of the high molecular weight antibody and its complex with rabbit Immuniglobulin G (IgG) with steady-state fluorescence anisotropy and time-resolved methods: solution phase immuno-assay was performed following either steady-state or time-resolved fluorescence anisotropy. By performing a variable temperature experiment it was determined that the binding of the ligand resulted in an increase in correlation time by more than 75 %, and a change in the steady-state anisotropy increase of 18%. The results show that the triangulenium class of dyes can be used in anisotropy assay for detecting binding events involving biomolecules of far larger size than what is possible with the other red emitting organic dyes. PMID:24058730

Calcein AM release-based cytotoxic cell assay for fish leucocytes.

Science.gov (United States)

Iwanowicz, Luke R; Densmore, Christine L; Ottinger, Christopher A

2004-02-01

A non-specific cytotoxic cell assay for fish is presented that is based on the release of the activated fluorochrome calcein AM from lysed carp epithelioma papulosum cyprini (EPC) cells. To establish the suitability of treating EPC cells with calcein AM the uptake and spontaneous release of the calcein AM by the EPC cells was evaluated. Incubation of 5 microM calcein AM in culture medium with 1x10(5)EPC cells well(-1)for a minimum of 3 h provided sufficient labelling. Spontaneous release of fluorescence from the labelled EPC cells during 10 h of post labelling incubation ranged from 30 to 39% of the total observed fluorescence. Cytotoxic activity of trout leucocytes was evaluated at three leucocyte to target cell ratios (10:1, 2:1 and 1:1) following incubation (4, 6, 8, and 10 h) with calcein AM-labelled EPC cells at 15 degrees C. In some instances, the monoclonal antibody specific for the NCC surface receptor NCCRP-1 (MAb5C.6) was included in the cultures. The activity of NCC cells was significantly inhibited in the presence of 0.25 microg well(-1)of MAb5C.6 relative to no antibody (Passay.

Voltammetry of osmium end-labeled oligodeoxynucleotides at carbon, mercury, and gold electrodes

Czech Academy of Sciences Publication Activity Database

Trefulka, Mojmír; Ferreyra, N.; Ostatná, Veronika; Fojta, Miroslav; Rivas, G.; Paleček, Emil

2007-01-01

Roč. 19, č. 12 (2007), s. 1334-1338 ISSN 1040-0397 R&D Projects: GA ČR(CZ) GA203/06/1685; GA AV ČR(CZ) KAN400310651; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040702 Keywords : modification of DNA * osmium complexes * electroactive labels Subject RIV: BO - Biophysics Impact factor: 2.949, year: 2007

Development of a high-throughput screening assay for stearoyl-CoA desaturase using rat liver microsomes, deuterium labeled stearoyl-CoA and mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Soulard, Patricia; McLaughlin, Meg; Stevens, Jessica; Connolly, Brendan; Coli, Rocco; Wang Leyu [Research Technology Center, Pfizer Global Research and Development, Cambridge, MA (United States); Moore, Jennifer; Kuo, Ming-Shang T. [Pfizer Global Research and Development, San Diego, CA (United States); LaMarr, William A.; Ozbal, Can C. [Biotrove, Inc., Woburn, MA (United States); Bhat, B. Ganesh [Pfizer Global Research and Development, San Diego, CA (United States)], E-mail: gbhat@gnf.org

2008-10-03

Several recent reports suggest that stearoyl-CoA desaturase 1 (SCD1), the rate-limiting enzyme in monounsaturated fatty acid synthesis, plays an important role in regulating lipid homeostasis and lipid oxidation in metabolically active tissues. As several manifestations of type 2 diabetes and related metabolic disorders are associated with alterations in intracellular lipid partitioning, pharmacological manipulation of SCD1 activity might be of benefit in the treatment of these disease states. In an effort to identify small molecule inhibitors of SCD1, we have developed a mass spectrometry based high-throughput screening (HTS) assay using deuterium labeled stearoyl-CoA substrate and induced rat liver microsomes. The methodology developed allows the use of a nonradioactive substrate which avoids interference by the endogenous SCD1 substrate and/or product that exist in the non-purified enzyme source. Throughput of the assay was up to twenty 384-well assay plates per day. The assay was linear with protein concentration and time, and was saturable for stearoyl-CoA substrate (K{sub m} = 10.5 {mu}M). The assay was highly reproducible with an average Z' value = 0.6. Conjugated linoleic acid and sterculic acid, known inhibitors of SCD1, exhibited IC{sub 50} values of 0.88 and 0.12 {mu}M, respectively. High-throughput mass spectrometry screening of over 1.7 million compounds in compressed format demonstrated that the enzyme target is druggable. A total of 2515 hits were identified (0.1% hit rate), and 346 were confirmed active (>40% inhibition of total SCD activity at 20 {mu}M - 14% conformation rate). Of the confirmed hits 172 had IC{sub 50} values of <10 {mu}M, including 111 <1 {mu}M and 48 <100 nM. A large number of potent drug-like (MW < 450) hits representing six different chemical series were identified. The application of mass spectrometry to high-throughput screening permitted the development of a high-quality screening protocol for an otherwise intractable

Development of a high-throughput screening assay for stearoyl-CoA desaturase using rat liver microsomes, deuterium labeled stearoyl-CoA and mass spectrometry

International Nuclear Information System (INIS)

Soulard, Patricia; McLaughlin, Meg; Stevens, Jessica; Connolly, Brendan; Coli, Rocco; Wang Leyu; Moore, Jennifer; Kuo, Ming-Shang T.; LaMarr, William A.; Ozbal, Can C.; Bhat, B. Ganesh

2008-01-01

Several recent reports suggest that stearoyl-CoA desaturase 1 (SCD1), the rate-limiting enzyme in monounsaturated fatty acid synthesis, plays an important role in regulating lipid homeostasis and lipid oxidation in metabolically active tissues. As several manifestations of type 2 diabetes and related metabolic disorders are associated with alterations in intracellular lipid partitioning, pharmacological manipulation of SCD1 activity might be of benefit in the treatment of these disease states. In an effort to identify small molecule inhibitors of SCD1, we have developed a mass spectrometry based high-throughput screening (HTS) assay using deuterium labeled stearoyl-CoA substrate and induced rat liver microsomes. The methodology developed allows the use of a nonradioactive substrate which avoids interference by the endogenous SCD1 substrate and/or product that exist in the non-purified enzyme source. Throughput of the assay was up to twenty 384-well assay plates per day. The assay was linear with protein concentration and time, and was saturable for stearoyl-CoA substrate (K m = 10.5 μM). The assay was highly reproducible with an average Z' value = 0.6. Conjugated linoleic acid and sterculic acid, known inhibitors of SCD1, exhibited IC 50 values of 0.88 and 0.12 μM, respectively. High-throughput mass spectrometry screening of over 1.7 million compounds in compressed format demonstrated that the enzyme target is druggable. A total of 2515 hits were identified (0.1% hit rate), and 346 were confirmed active (>40% inhibition of total SCD activity at 20 μM - 14% conformation rate). Of the confirmed hits 172 had IC 50 values of <10 μM, including 111 <1 μM and 48 <100 nM. A large number of potent drug-like (MW < 450) hits representing six different chemical series were identified. The application of mass spectrometry to high-throughput screening permitted the development of a high-quality screening protocol for an otherwise intractable target, SCD1. Further medicinal

What's in a Label? Is Diagnosis the Start or the End of Clinical Reasoning?

Science.gov (United States)

Ilgen, Jonathan S; Eva, Kevin W; Regehr, Glenn

2016-04-01

Diagnostic reasoning has received substantial attention in the literature, yet what we mean by "diagnosis" may vary. Diagnosis can align with assignment of a "label," where a constellation of signs, symptoms, and test results is unified into a solution at a single point in time. This "diagnostic labeling" conceptualization is embodied in our case-based learning curricula, published case reports, and research studies, all of which treat diagnostic accuracy as the primary outcome. However, this conceptualization may oversimplify the richly iterative and evolutionary nature of clinical reasoning in many settings. Diagnosis can also represent a process of guiding one's thoughts by "making meaning" from data that are intrinsically dynamic, experienced idiosyncratically, negotiated among team members, and rich with opportunities for exploration. Thus, there are two complementary constructions of diagnosis: 1) the correct solution resulting from a diagnostic reasoning process, and 2) a dynamic aid to an ongoing clinical reasoning process. This article discusses the importance of recognizing these two conceptualizations of "diagnosis," outlines the unintended consequences of emphasizing diagnostic labeling as the primary goal of clinical reasoning, and suggests how framing diagnosis as an ongoing process of meaning-making might change how we think about teaching and assessing clinical reasoning.

A study of the 51Cr release assay system in micro-method

International Nuclear Information System (INIS)

Kiya, Katsuzo; Harada, Kiyoshi; Uozumi, Tohru; Toge, Tetsuya; Hattori, Takao.

1981-01-01

Conditions of 51 Cr release assay in microculture were investigated to measure the natural cytotoxic (NC) activity of mouse spleen cells. Malignant glioma (MG) cells of C57BL/6 mouse, induced by 20-methylcholanthrene, were labeled with Na 2 51 CrO 4 . Spleen cells collected from the same mouse strain were suspended in Eagle's MEM. Labeled MG cells and spleen cells were incubated for several hours in a CO 2 incubator. Then the activity of the supernatant was measured by an automatic gamma counter. The optimum conditions of 51 Cr release assay in micro-culture were, (1) number of the target cells: 5 x 10 3 / well (2) FCS concentration: 10% (3) E/T ratio: less than 100 : 1, 50 : 1 was possible (4) incubation time: 15 hours. The number of the target cells at labeling incubation was set to 2 x 10 6 /ml. Though the natural release of 51 Cr was not effected by the viability of the target cells, it was suggested that the NC activity was dependent on the viability of both cells, target and effector cells. (Tsunoda, M.)

Study of the /sup 51/Cr release assay system in micro-method

Energy Technology Data Exchange (ETDEWEB)

Kiya, K.; Harada, K.; Uozumi, T. (Hiroshima Univ. (Japan). School of Medicine); Toge, T.; Hattori, T.

1981-05-01

Conditions of /sup 51/Cr release assay in microculture were investigated to measure the natural cytotoxic (NC) activity of mouse spleen cells. Malignant glioma (MG) cells of C57BL/6 mouse, induced by 20-methylcholanthrene, were labeled with Na/sub 2//sup 51/CrO/sub 4/. Spleen cells collected from the same mouse strain were suspended in Eagle's MEM. Labeled MG cells and spleen cells were incubated for several hours in a CO/sub 2/ incubator. Then the activity of the supernatant was measured by an automatic gamma counter. The optimum conditions of /sup 51/Cr release assay in micro-culture were, (1) number of the target cells: 5 x 10/sup 3// well (2) FCS concentration: 10% (3) E/T ratio: less than 100 : 1, 50 : 1 was possible (4) incubation time: 15 hours. The number of the target cells at labeling incubation was set to 2 x 10/sup 6//ml. Though the natural release of /sup 51/Cr was not effected by the viability of the target cells, it was suggested that the NC activity was dependent on the viability of both cells, target and effector cells.

Specific dot-immunobinding assay for detection and enumeration of Thiobacillus ferrooxidans

International Nuclear Information System (INIS)

Arredondo, R.; Jerez, C.A.

1989-01-01

A specific and very sensitive dot-immunobinding assay for the detection and enumeration of the bioleaching microorganism Thiobacillus ferrooxidans was developed. Nitrocellulose spotted with samples was incubated with polyclonal antisera against whole T. ferrooxidans cells and then in 125 I-labeled protein A or 125 I-labeled goat antirabbit immunoglobulin G; incubation was followed by autoradiography. Since a minimum of 10 3 cells per dot could be detected, the method offers the possibility of simultaneous processing of numerous samples in a short time to monitor the levels of T. ferrooxidans in bioleaching operations

Immobilization of antibodies and enzyme-labeled antibodies by radiation polymerization

International Nuclear Information System (INIS)

Kumakura, M.; Kaetsu, I.; Suzuki, M.; Adachi, S.

1983-01-01

Immobilization of antibodies and enzyme-labeled antibodies by radiation polymerization at low temperatures was studied. The antibody activity of antibody was not affected by irradiation at an irradiation dose of below 8 MR and low temperatures. Immobilization of peroxidase-labeled anti-rabbit IgG goat IgG, anti-peroxidase, peroxidase, and anti-alpha-fetoprotein was carried out with hydrophilic and hydrophobic monomers. The activity of the immobilized enzyme-labeled antibody membranes varied with the thickness of the membranes and increased with decreasing membrane thickness. The activity of the immobilized antibody particles was varied by particle size. Immobilized anti-alpha-fetoprotein particles and membranes can be used for the assay of alpha-fetoprotein by the antigen-antibody reaction, such as a solid-phase sandwich method with high sensitivity

Neuroma prevention by end-to-side neurorraphy: an experimental study in rats.

Science.gov (United States)

Aszmann, Oskar C; Korak, Klaus J; Rab, Matthias; Grünbeck, Matthias; Lassmann, Hans; Frey, Manfred

2003-11-01

The successful treatment of painful neuromas remains a difficult goal to attain. In this report we explore the feasibility of neuroma prevention by insertion of the proximal end of a nerve through an end-to-side neurorraphy into an adjacent mixed nerve to provide a pathway and target for axons deprived of their end organ. Experiments were performed on a total of twenty 250-g Sprague-Dawley rats. Two groups of 10 animals were prepared. Group A served as an anatomic control. In group B the right saphenous nerve was transected and implanted end-to-side through an epineurial window into the tibial nerve distal to the trifurcation of the sciatic nerve. After 12 weeks the corresponding sensory neurons were identified by retrograde labeling techniques and histomorphometric analysis of the proximal and distal tibial nerve segments, and regular histology of the end-to-side site were performed. The results of the retrograde labeling of the corresponding sensory neuron pool of the saphenus nerve showed extensive labelling of the L1 to L3 spinal ganglions after intracutaneous tracer application of the planta pedis. The morphology of the end-to-side coaptation site and histomorphologic analysis prove that sensory neurons penetrate the perineurial sheath and axons regenerate along the tibial Schwann cell tubes toward their targets. Axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented. Whether these axons will lead to disturbing sensations such as paresthesia or dysesthesia in the newly found environment or remain silent codwellers, this experiment cannot answer. Long-term results of future clinical work will have to decide whether the prevention of the neuroma through end-to-side coaptation will be an appropriate therapy for this difficult problem.

Quantum dot labeling and tracking of cultured limbal epithelial cell transplants in-vitro

Science.gov (United States)

Genicio, Nuria; Paramo, Juan Gallo; Shortt, Alex J.

2015-01-01

PURPOSE Cultured human limbal epithelial cells (HLEC) have shown promise in the treatment of limbal stem cell deficiency but little is known about their survival, behaviour and long-term fate post transplantation. The aim of this research was to evaluate, in-vitro, quantum dot (QDot) technology as a tool for tracking transplanted HLEC. METHODS In-vitro cultured HLEC were labeled with Qdot nanocrystals. Toxicity was assessed using live-dead assays. The effect on HLEC function was assessed using colony forming efficiency assays and expression of CK3, P63alpha and ABCG2. Sheets of cultured HLEC labeled with Qdot nanocrystals were transplanted onto decellularised human corneo-scleral rims in an organ culture model and observed to investigate the behaviour of transplanted cells. RESULTS Qdot labeling had no detrimental effect on HLEC viability or function in-vitro. Proliferation resulted in a gradual reduction in Qdot signal but sufficient signal was present to allow tracking of cells through multiple generations. Cells labeled with Qdots could be reliably detected and observed using confocal microscopy for at least 2 weeks post transplantation in our organ culture model. In addition it was possible to label and observe epithelial cells in intact human corneas using the Rostock corneal module adapted for use with the Heidelberg HRA. CONCLUSIONS This work demonstrates that Qdots combined with existing clinical equipment could be used to track HLEC for up to 2 weeks post transplantation, however, our model does not permit the assessment of cell labeling beyond 2 weeks. Further characterisation in in-vivo models are required. PMID:26024089

Genotoxic evaluation of [DOTA,Tyr3]octreotate labeled with 131I and 177Lu in human peripheral lymphocytes in vitro by micronucleus assay

International Nuclear Information System (INIS)

Suzauki, Miriam Fussae; Silva, Marcia Augusta da; Caldeira Filho, Jose de Souza; Colturato, Maria Tereza; Araujo, Elaine Bortoleti de; Bartolini, Paolo; Okazaki, Kayo

2005-01-01

The radiolabeled receptor-binding peptides have being used for cancer diagnosis and therapy. The octreotate, a somatostatin analogue peptide, bound to various tumors expressing sst receptors (thyroid, pancreas, prostrate, melanoma and lymphomas). The amount and the type of receptors for somatostatin influence the tissue uptake. The [DOTA, Tyr 3 ]octreotate has been used because of its high affinity to somatostatin subtype receptors sstr 2 and sstr 5 . The pharmacokinetic study showed that the blood clearance is rapid and only 9% of the intravenous injected activity remains in human blood after one hour. The aim of this study was to evaluate the cytogenetic effect of radiolabeled [DOTA, Tyr 3 ]octreotate in blood cells in vitro, using the cytokinesis-block micronucleus (MN) assay. This technique allows evaluating the mutagenic effects of both endogenous and exogenous agents at chromosome level. Blood samples of healthy donors were collected in heparinized syringes and exposed to different activities of [DOTA, Tyr 3 ]octreotate labeled with with 131 I (n=3) and 177 Lu (n=3), where radioactive concentration ranged from 600 to 5600 kBq/mL, corresponding to an injected activity of 3.1 to 28.9 GBq in a reference man of 70 kg weight. 131 I and 177 Lu are beta- and gamma-emitters. After one-hour exposition to radiopharmaceuticals at 37 deg C, the cells were washed with culture medium for removing the non internalised octreotate and cultivated for 72 hours, according to criteria adopted by the IAEA. The results showed a positive correlation between radioactive concentrations (X) and the frequency of binucleated cells with micronuclei (Y) (P 131 I-DOTA, Tyr 3 ]octreotate was Y = (1.634 ± 0.236) + (0.912 ± 0.137) 10 -3 X and for [ 177 Lu-DOTA, Tyr 3 ]octreotate was Y = (1.715 ± 0.342) + (0.743 ± 0.135) 10 -3 X. The non labeled molecule, [DOTA, Tyr 3 ]octreotate, has no influence in the induction of cytogenetic damage. The micronucleus assay with rat pancreatic tumor cells

The Extract of Aster Koraiensis Prevents Retinal Pericyte Apoptosis in Diabetic Rats and Its Active Compound, Chlorogenic Acid Inhibits AGE Formation and AGE/RAGE Interaction

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Junghyun Kim

2016-09-01

Full Text Available Retinal capillary cell loss is a hallmark of early diabetic retinal changes. Advanced glycation end products (AGEs are believed to contribute to retinal microvascular cell loss in diabetic retinopathy. In this study, the protective effects of Aster koraiensis extract (AKE against damage to retinal vascular cells were investigated in streptozotocin (STZ-induced diabetic rats. To examine this issue further, AGE accumulation, nuclear factor-kappaB (NF-κB and inducible nitric oxide synthase (iNOS were investigated using retinal trypsin digests from streptozotocin-induced diabetic rats. In the diabetic rats, TUNEL (Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling-positive retinal microvascular cells were markedly increased. Immunohistochemical studies revealed that AGEs were accumulated within the retinal microvascular cells, and this accumulation paralleled the activation of NF-κB and the expression of iNOS in the diabetic rats. However, AKE prevented retinal microvascular cell apoptosis through the inhibition of AGE accumulation and NF-κB activation. Moreover, to determine the active compounds of AKE, two major compounds, chlorogenic acid and 3,5-di-O-caffeoylquinic acid, were tested in an in vitro assay. Among these compounds, chlorogenic acid significantly reduced AGE formation as well as AGE/RAGE (receptor for AGEs binding activity. These results suggest that AKE, particularly chlorogenic acid, is useful in inhibiting AGE accumulation in retinal vessels and exerts a preventive effect against the injuries of diabetic retinal vascular cells.

Radiation-induced hyperproliferation of intestinal crypts results in elevated genome instability with inactive p53-related genomic surveillance.

Science.gov (United States)

Zhou, Xin; Ma, Xiaofei; Wang, Zhenhua; Sun, Chao; Wang, Yupei; He, Yang; Zhang, Hong

2015-12-15

Radiation-induced hyperproliferation of intestinal crypts is well documented, but its potential tumorigenic effects remain elusive. Here we aim to determine the genomic surveillance process during crypt hyperproliferation, and its consequential outcome after ionizing radiation. Crypt regeneration in the intestine was induced by a single dose of 12Gy abdominal irradiation. γ-H2AX, 53BP1 and DNA-PKcs were used as DNA repair surrogates to investigate the inherent ability of intestinal crypt cells to recognize and repair double-strand breaks. Ki67 staining and the 5-bromo-2'-deoxyuridine incorporation assay were used to study patterns of cell proliferation in regenerating crypts. Staining for ATM, p53, Chk1 and Chk2 was performed to study checkpoint activation and release. Apoptosis was evaluated through H&E staining and terminal deoxynucleotidyl transferase (dUTP) nick-end labeling. The ATM-p53 pathway was immediately activated after irradiation. A second wave of DSBs in crypt cells was observed in regenerating crypts, accompanied with significantly increased chromosomal bridges. The p53-related genomic surveillance pathway was not active during the regeneration phase despite DSBs and chromosomal bridges in the cells of regenerating crypts. Non-homologous end joining (NHEJ) DSBs repair was involved in the DSBs repair process, as indicated by p-DNA-PKcs staining. Intestinal crypt cells retained hyperproliferation with inactive p53-related genomic surveillance system. NHEJ was involved in the resultant genomic instability during hyperproliferation. Copyright © 2015 Elsevier Inc. All rights reserved.

Benefits of gene transduction of granulocyte macrophage colony-stimulating factor in cancer vaccine using genetically modified dendritic cells.

Science.gov (United States)

Ojima, Toshiyasu; Iwahashi, Makoto; Nakamura, Masaki; Matsuda, Kenji; Nakamori, Mikihito; Ueda, Kentaro; Naka, Teiji; Katsuda, Masahiro; Miyazawa, Motoki; Yamaue, Hiroki

2007-10-01

Granulocyte macrophage colony-stimulating factor (GM-CSF) is a key cytokine for the generation and stimulation of dendritic cells (DCs), and it may also play a pivotal role in promoting the survival of DCs. In this study, the feasibility of creating a cancer vaccine using DCs adenovirally transduced with the carcinoembryonic antigen (CEA) gene and the GM-CSF gene was examined. In addition, the effect of the co-transduction of GM-CSF gene on the lifespan of these genetically modified DCs was determined. A cytotoxic assay using peripheral blood mononuclear cell (PBMC)-derived cytotoxic T lymphocytes (CTLs) was performed in a 4-h 51Cr release assay. The apoptosis of DCs was examined by TdT-mediated dUTP-FITC nick end labeling (TUNEL) assay. CEA-specific CTLs were generated from PBMCs stimulated with genetically modified DCs expressing CEA. The cytotoxicity of these CTLs was augmented by co-transduction of DCs with the GM-CSF gene. Co-transduction of the GM-CSF gene into DCs inhibited apoptosis of these DCs themselves via up-regulation of Bcl-x(L) expression, leading to the extension of the lifespan of these DCs. Furthermore, the transduction of the GM-CSF gene into DCs also suppressed the incidence of apoptosis of DCs induced by transforming growth factor-beta1 (TGFbeta-1). Immunotherapy using these genetically modified DCs may therefore be useful with several advantages as follows: i) adenoviral toxicity to DCs can be reduced; ii) the lifespan of vaccinated DCs can be prolonged; and iii) GM-CSF may protect DCs from apoptosis induced by tumor-derived TGFbeta-1 in the regional lymph nodes.

In Vitro and In Vivo Efficacy Studies of Lavender angustifolia Essential Oil and Its Active Constituents on the Proliferation of Human Prostate Cancer

Science.gov (United States)

Zhao, Yunqi; Chen, Ran; Wang, Yun; Qing, Chen; Wang, Wei; Yang, Yixin

2016-01-01

Lavandula angustifolia is the most widely cultivated Lavandula species. The extraction of its flower and leaves has been used as herbal medicine. In this study, the in vitro antitumor activities were tested on human prostate cancer PC-3 and DU145 cell lines. Flow cytometry technology was applied to study apoptosis induction and cell cycle arrest. The PC-3 cell line was used to establish subcutaneous xenograft tumors in nude mice. Paraffin sections from xenograft tumor specimens were used in the TUNEL (terminal deocynucleotide transferase dUTP nick end labeling) assay and an immunohistochemistry assay to detect cell proliferation markers Ki67 and PCNA. Lavender essential oil, linalool, and linalyl acetate showed stronger inhibitory effect on PC-3 cells than on DU145 cells. The apoptotic cell populations observed in PC-3 cells treated with lavender essential oil, linalool, and linalyl acetate were 74.76%, 67.11%, and 56.14%, respectively. The PC-3 cells were mainly arrested in the G2/M phase. In the xenograft model with PC-3 cell transplantation, essential oil and linalool significantly suppressed tumor growth. The immunosignals of Ki67 and PCNA in the essential oil, linalool, and linalyl acetate treatment groups were significantly lower than that of the control group in xenograft tumor sections. The TUNEL assay indicated that each of the 3 phytochemicals significantly induced apoptosis compared to the control group. This study provides novel insight and evidence on the antiproliferative effect of L angustifolia essential oil and its major constituents on human prostate cancer. The antitumor effect was associated with cell proliferation inhibition and apoptosis induction in xenograft tumors. PMID:27151584

Inhibition of CUG-binding protein 1 and activation of caspases are critically involved in piperazine derivative BK10007S induced apoptosis in hepatocellular carcinoma cells.

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Ju-Ha Kim

Full Text Available Though piperazine derivative BK10007S was known to induce apoptosis in pancreatic cancer xenograft model as a T-type CaV3.1 a1G isoform calcium channel blocker, its underlying antitumor mechanism still remains unclear so far. Thus, in the present study, the antitumor mechanism of BK10007S was elucidated in hepatocellular carcinoma cells (HCCs. Herein, BK10007S showed significant cytotoxicity by 3-[4,5-2-yl]-2,5-diphenyltetra-zolium bromide (MTT assay and anti-proliferative effects by colony formation assay in HepG2 and SK-Hep1 cells. Also, apoptotic bodies and terminal deoxynucleotidyl transferase (TdT dUTP Nick End Labeling (TUNEL positive cells were observed in BK10007S treated HepG2 and SK-Hep1 cells by 4',6-diamidino-2-phenylinodole (DAPI staining and TUNEL assay, respectively. Consistently, BK10007S increased sub G1 population in HepG2 and SK-Hep1 cells by cell cycle analysis. Furthermore, Western blotting revealed that BK10007S activated the caspase cascades (caspase 8, 9 and 3, cleaved poly (ADP-ribose polymerase (PARP, and downregulated the expression of cyclin D1, survivin and for CUG-binding protein 1 (CUGBP1 or CELF1 in HepG2 and SK-Hep1 cells. Conversely, overexpression of CUGBP1 reduced cleavages of PARP and caspase 3, cytotoxicity and subG1 population in BK10007S treated HepG2 cells. Overall, these findings provide scientific evidences that BK10007S induces apoptosis via inhibition of CUGBP1 and activation of caspases in hepatocellular carcinomas as a potent anticancer candidate.

The telomere length dynamic and methods of its assessment.

Science.gov (United States)

Lin, Kah-Wai; Yan, Ju

2005-01-01

Human telomeres are composed of long repeating sequences of TTAGGG, associated with a variety of telomere-binding proteins. Its function as an end-protector of chromosomes prevents the chromosome from end-to-end fusion, recombination and degradation. Telomerase acts as reverse transcriptase in the elongation of telomeres, which prevent the loss of telomeres due to the end replication problems. However, telomerase activity is detected at low level in somatic cells and high level in embryonic stem cells and tumor cells. It confers immortality to embryonic stem cells and tumor cells. In most tumor cells, telomeres are extremely short and stable. Telomere length is an important indicator of the telomerase activity in tumor cells and it may be used in the prognosis of malignancy. Thus, the assessment of telomeres length is of great experimental and clinical significance. This review describes the role of telomere and telomerase in cancer pathogenesis and the dynamics of the telomeres length in different cell types. The various methods of measurement of telomeres length, i.e. southern blot, hybridization protection assay, fluorescence in situ hybridization, primed in situ, quantitative PCR and single telomere length analysis are discussed. The principle and comparative evaluation of these methods are reviewed. The detection of G-strand overhang by telomeric-oligonucleotide ligation assay, primer extension/nick translation assay and electron microscopy are briefly discussed.

Nanoplasmonic biochips for rapid label-free detection of imidacloprid pesticides with a smartphone.

Science.gov (United States)

Lee, Kuang-Li; You, Meng-Lin; Tsai, Chia-Hsin; Lin, En-Hung; Hsieh, Shu-Yi; Ho, Ming-Hsun; Hsu, Ju-Chun; Wei, Pei-Kuen

2016-01-15

The widespread and intensive use of neonicotinoid insecticides induces negative cascading effects on ecosystems. It is desirable to develop a portable sensitive sensing platform for on-site screening of high-risk pesticides. We combined an indirect competitive immunoassay, highly sensitive surface plasmon resonance (SPR) biochip and a simple portable imaging setup for label-free detection of imidacloprid pesticides. The SPR biochip consists of several capped nanoslit arrays with different periods which form a spectral image on the chip. The qualitative and semiquantitative analyses of pesticides can be directly observed from the spot shift on the chip. The precise semiquantitative analyses can be further completed by using image processing in a smartphone. We demonstrate simultaneous detection of four different concentrations of imidacloprid pesticides. The visual detection limit is about 1ppb, which is well below the maximum residue concentration permitted by law (20ppb). Compared to the one-step strip assay, the proposed chip is capable of performing semiquantitative analyses and multiple detection. Compared to the enzyme-linked immunosorbent assay, our method is label-free and requires simple washing steps and short reaction time. In addition, the label-free chip has a comparable sensitivity but wider working range than those labeling techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

The synthesis and characterization of biotin-silver-dendrimer nanocomposites as novel bioselective labels

Energy Technology Data Exchange (ETDEWEB)

Maly, J; Lampova, H; Semeradtova, A; Stofik, M [Faculty of Science, University of J E Purkynje, 40096 Usti nad Labem (Czech Republic); Kovacik, L, E-mail: malyjalga@seznam.c [Institute of Cellular Biology and Pathology, First Faculty of Medicine, Charles University in Prague (Czech Republic)

2009-09-23

This paper presents a synthesis of a novel nanoparticle label with selective biorecognition properties based on a biotinylated silver-dendrimer nanocomposite (AgDNC). Two types of labels, a biotin-AgDNC (bio-AgDNC) and a biotinylated AgDNC with a poly(ethylene)glycol spacer (bio-PEG-AgDNC), were synthesized from a generation 7 (G7) hydroxyl-terminated ethylenediamine-core-type (2-carbon core) PAMAM dendrimer (DDM) by an N,N'-dicyclohexylcarbodiimide (DDC) biotin coupling and a NaBH{sub 4} silver reduction method. Synthesized conjugates were characterized by several analytical methods, such as UV-vis, FTIR, AFM, TEM, ELISA, HABA assay and SPR. The results show that stable biotinylated nanocomposites can be formed either with internalized silver nanoparticles (AgNPs) in a DMM polymer backbone ('type I') or as externally protected ('type E'), depending on the molar ratio of the silver/DMM conjugate and type of conjugate. Furthermore, the selective biorecognition function of the biotin is not affected by the AgNPs' synthesis step, which allows a potential application of silver nanocomposite conjugates as biospecific labels in various bioanalytical assays, or potentially as fluorescence cell biomarkers. An exploitation of the presented label in the development of electrochemical immunosensors is anticipated.

High-sensitivity immunochromatographic assay for fumonisin B1 based on indirect antibody labeling.

Science.gov (United States)

Urusov, Alexandr E; Petrakova, Alina V; Gubaydullina, Milyausha K; Zherdev, Anatoly V; Eremin, Sergei A; Kong, Dezhao; Liu, Liqiang; Xu, Chuanlai; Dzantiev, Boris B

2017-05-01

To develop a high-sensitivity immunochromatographic test for fumonisin B1 in plant extracts. Unlike conventional immunochromatographic tests, this assay is performed in two stages: competitive reaction with free specific antibodies and identifying immune complexes by their interaction with the anti-species antibody-conjugated gold nanoparticles. The use of a new geometry for the test strip membranes and a novel reagent application method ensures the proper order of these stages without additional manipulations. The contact of the ready-to-use test strip with the liquid sample suffices in initiating all stages of the assay and obtaining test results. The developed test was used on corn extracts; its instrumental limit of fumonisin B1 detection was 0.6 ng ml -1 at 15 min of assay duration. The proposed approach is flexible and can be used for a wide range of low molecular compounds. The use of anti-species antibody-conjugated gold nanoparticles in immunochromatography significantly facilitates the development of test systems by eliminating the need to synthesize and characterize the conjugates with specific antibodies for each new compound to be detected.

Therapeutic effects of microbubble added to combined high-intensity focused ultrasound and chemotherapy in a pancreatic cancer xenograft model

Energy Technology Data Exchange (ETDEWEB)

Yu, Mi Hye [Dept. of Radiology, Konkuk University Medical Center, Seoul (Korea, Republic of); Lee, Jae Young; Kim, Bo Ram; Park, Eun Joo; Kim, Hoe Suk; Han, Joon Koo [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Hae Ri [Dept. of Pre-Dentistry, Gangneung-Wonju National University College of Dentistry, Gangneung (Korea, Republic of); Choi, Byung Ihn [Dept. of Radiology, Chung-Ang University Hospital, Seoul (Korea, Republic of)

2016-09-15

To investigate whether high-intensity focused ultrasound (HIFU) combined with microbubbles enhances the therapeutic effects of chemotherapy. A pancreatic cancer xenograft model was established using BALB/c nude mice and luciferase-expressing human pancreatic cancer cells. Mice were randomly assigned to five groups according to treatment: control (n = 10), gemcitabine alone (GEM; n = 12), HIFU with microbubbles (HIFU + MB, n = 11), combined HIFU and gemcitabine (HIGEM; n = 12), and HIGEM + MB (n = 13). After three weekly treatments, apoptosis rates were evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay in two mice per group. Tumor volume and bioluminescence were monitored using high-resolution 3D ultrasound imaging and in vivo bioluminescence imaging for eight weeks in the remaining mice. The HIGEM + MB group showed significantly higher apoptosis rates than the other groups (p < 0.05) and exhibited the slowest tumor growth. From week 5, the tumor-volume-ratio relative to the baseline tumor volume was significantly lower in the HIGEM + MB group than in the control, GEM, and HIFU + MB groups (p < 0.05). Despite visible distinction, the HIGEM and HIGEM + MB groups showed no significant differences. High-intensity focused ultrasound combined with microbubbles enhances the therapeutic effects of gemcitabine chemotherapy in a pancreatic cancer xenograft model.

Therapeutic Effects of Microbubbles Added to Combined High-Intensity Focused Ultrasound and Chemotherapy in a Pancreatic Cancer Xenograft Model

Energy Technology Data Exchange (ETDEWEB)

Yu, Mi Hye [Department of Radiology, Konkuk University Medical Center, Seoul 05030 (Korea, Republic of); Lee, Jae Young [Department of Radiology, Seoul National University Hospital, Seoul 03080 (Korea, Republic of); Kim, Hae Ri [Department of Pre-Dentistry, Gangneung-Wonju National University College of Dentistry, Gangneung 25457 (Korea, Republic of); Kim, Bo Ram; Park, Eun-Joo; Kim, Hoe Suk; Han, Joon Koo [Department of Radiology, Seoul National University Hospital, Seoul 03080 (Korea, Republic of); Choi, Byung Ihn [Department of Radiology, Chung-Ang University Hospital, Seoul 06973 (Korea, Republic of)

2016-11-01

To investigate whether high-intensity focused ultrasound (HIFU) combined with microbubbles enhances the therapeutic effects of chemotherapy. A pancreatic cancer xenograft model was established using BALB/c nude mice and luciferase-expressing human pancreatic cancer cells. Mice were randomly assigned to five groups according to treatment: control (n = 10), gemcitabine alone (GEM; n = 12), HIFU with microbubbles (HIFU + MB, n = 11), combined HIFU and gemcitabine (HIGEM; n = 12), and HIGEM + MB (n = 13). After three weekly treatments, apoptosis rates were evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay in two mice per group. Tumor volume and bioluminescence were monitored using high-resolution 3D ultrasound imaging and in vivo bioluminescence imaging for eight weeks in the remaining mice. The HIGEM + MB group showed significantly higher apoptosis rates than the other groups (p < 0.05) and exhibited the slowest tumor growth. From week 5, the tumor-volume-ratio relative to the baseline tumor volume was significantly lower in the HIGEM + MB group than in the control, GEM, and HIFU + MB groups (p < 0.05). Despite visible distinction, the HIGEM and HIGEM + MB groups showed no significant differences. High-intensity focused ultrasound combined with microbubbles enhances the therapeutic effects of gemcitabine chemotherapy in a pancreatic cancer xenograft model.

Effect of SMAD7 gene overexpression on TGF-β1-induced profibrotic responses in fibroblasts derived from Peyronie's plaque

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Min Ji Choi

2015-06-01

Full Text Available Transforming growth factor-β1 (TGF-β1 has been identified as one of the most important fibrogenic cytokines associated with Peyronie's disease (PD. The mothers against decapentaplegic homolog 7 (SMAD7 is an inhibitory Smad protein that blocks TGF-β signaling pathway. The aim of this study was to examine the anti-fibrotic effect of the SMAD7 gene in primary fibroblasts derived from human PD plaques. PD fibroblasts were pretreated with the SMAD7 gene and then stimulated with TGF-β1. Treated fibroblasts were used for Western blotting, fluorescent immunocytochemistry, hydroxyproline determination, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assays. Overexpression of the SMAD7 gene inhibited TGF-β1-induced phosphorylation and nuclear translocation of SMAD2 and SMAD3, transdifferentiation of fibroblasts into myofibroblasts, and quashed TGF-β1-induced production of extracellular matrix protein and hydroxyproline. Overexpression of the SMAD7 gene decreased the expression of cyclin D1 (a positive cell cycle regulator and induced the expression of poly (ADP-ribose polymerase 1, which is known to terminate Smad-mediated transcription, in PD fibroblasts. These findings suggest that the blocking of the TGF-β pathway by use of SMAD7 may be a promising therapeutic strategy for the treatment of PD.

Possible Causes of Ileal Injury in Two Models of Microbial Sepsis and Protective Effect of Phytic Acid

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Rasha Rashad Ahmed

2010-03-01

Full Text Available Background: Sepsis related-multiple organ dysfunction is associatedwith ileum injury. We aimed to determine the causes ofileal injury in two models of microbial sepsis resulted from infectionwith Aeromonas hydrophila or its endotoxin. We alsoevaluated the protective effect of phytic acid.Methods: Thin sections of ileum from 60 Swiss male mice incontrol, bacteria-infected or lipopolysaccharides (LPS andbacteria-infected or LPS-infected co-administered with phyticacid were subjected to histopathological and TdT-mediateddUTP nick-end labeling (TUNEL assay for apoptotic cellsdetection while ultra thin sections were stained with uranylacetate and lead citrate for cytological changes examination.Also, ileum images were exposed to the image analysis softwareto determine some related morphometric measures.Results: Necrosis and apoptosis were observed in ileum injuryin both examined sepsis models. The ileum injury was moresevere in LPS model. Phytic acid showed the ability to attenuateileum injury in Aeromonas hydrophila and its endotoxinmodels of sepsis after four weeks administration where itssupplementation significantly minimized the histopathologicaland cytological complications and morphometric alterationsresulted from the injury.Conclusion: The protective effects of phytic acid may becaused by increased mucous secretion, decreased apoptoticindex, attenuating the inflammatory and lymphocytic cellscount or increasing the renewal of the crypt cells and villousepithelial cells proliferation.

Aerosol-delivered programmed cell death 4 enhanced apoptosis, controlled cell cycle and suppressed AP-1 activity in the lungs of AP-1 luciferase reporter mice.

Science.gov (United States)

Hwang, S-K; Jin, H; Kwon, J T; Chang, S-H; Kim, T H; Cho, C-S; Lee, K H; Young, M R; Colburn, N H; Beck, G R; Yang, H-S; Cho, M-H

2007-09-01

The long-term survival of lung cancer patients treated with conventional therapies remains poor and therefore the need for novel approaches remains high. This has led to the re-emergence of aerosol delivery as a therapeutic intervention. In this study, glucosylated polyethylenimine (GPEI) was used as carrier to investigate programmed cell death 4 (PDCD4) and PDCD4 mutant (D418A), an eIF4A-binding mutant, on PDCD4-related signaling and activator protein-1 (AP-1) activity in the lungs of AP-1 luciferase reporter mice. After confirming the efficiency of GPEI as a carrier in lungs, the effects of aerosol-delivered PDCD4 were investigated in AP-1 luciferase reporter mice. Aerosol delivery of GPEI/PDCD4 through a nose-only inhalation facilitated the apoptosis of lungs whereas aerosol PDCD4 mutant did not. Also, such aerosol delivery regulated proteins relevant to cell-cycle control and suppressed AP-1 activity. Results obtained by western blot analysis, immunohistochemistry, luciferase assay and deoxynucleotidyl-transferase-mediated nick end labeling study suggest that combined actions such as facilitating apoptosis, controlling cell cycle and suppression of AP-1 activity by PDCD4 may provide useful tool for designing lung tumor prevention and treatment by which PDCD4 functions as a transformation suppressor in the future.

Effects of topical vitamin E on keratocyte apoptosis after traditional photorefractive keratectomy.

Science.gov (United States)

Bilgihan, K; Adiguzel, U; Sezer, C; Akyol, G; Hasanreisoglu, B

2001-01-01

To evaluate the keratocyte apoptosis and effects of topical vitamin E on keratocyte apoptosis after photorefractive surgery. Rabbits were divided into 7 groups, and all groups were compared with controls after epithelial scraping, epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK), transepithelial PRK, production of a corneal flap with microkeratome and laser-assisted in situ keratomileusis (LASIK). The effects of topical Vitamin E treatment were investigated in the traditional PRK group. The terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy have been used to detect apoptosis in rabbit cornea. Transepithelial PRK induced minimal keratocyte apoptosis, less than in all other refractive surgical procedures. The greatest amount of keratocyte apoptosis was observed after traditional PRK (p = 0.001), therefore we tested the effects of topical vitamin E in this group. The number of apoptotic keratocytes significantly reduced after vitamin E therapy (p < 0.005). Keratocytes undergo apoptosis after refractive surgery in response to mechanical epithelial removal, preparing of corneal flap and excimer laser stromal photoablation. The topical application of vitamin E immediately after surgery can prevent keratocyte apoptosis, and this result suggests that free radicals may be partly responsible for keratocyte apoptosis after excimer laser keratectomy. Copyright 2001 S. Karger AG, Basel

Protective Effects of Soy Oligopeptides in Ultraviolet B-Induced Acute Photodamage of Human Skin

Directory of Open Access Journals (Sweden)

Bing-rong Zhou

2016-01-01

Full Text Available Aim. We explored the effects of soy oligopeptides (SOP in ultraviolet B- (UVB- induced acute photodamage of human skin in vivo and foreskin ex vivo. Methods. We irradiated the forearm with 1.5 minimal erythemal dose (MED of UVB for 3 consecutive days, establishing acute photodamage of skin, and topically applied SOP. Erythema index (EI, melanin index, stratum corneum hydration, and transepidermal water loss were measured by using Multiprobe Adapter 9 device. We irradiated foreskin ex vivo with the same dose of UVB (180 mJ/cm2 for 3 consecutive days and topically applied SOP. Sunburn cells were detected by using hematoxylin and eosin staining. Apoptotic cells were detected by using terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Cyclobutane pyrimidine dimers (CPDs, p53 protein, Bax protein, and Bcl-2 protein were detected by using immunohistochemical staining. Results. Compared with UVB group, UVB-irradiated skin with topically applied SOP showed significantly decreased EI. Compared with UVB group, topical SOP significantly increased Bcl-2 protein expression and decreased CPDs-positive cells, sunburn cells, apoptotic cells, p53 protein expression, and Bax protein expressions in the epidermis of UVB-irradiated foreskin. Conclusion. Our study demonstrated that topical SOP can protect human skin against UVB-induced photodamage.

Melatonin mitigates neomycin-induced hair cell injury in zebrafish.

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Oh, Kyoung Ho; Rah, Yoon Chan; Hwang, Kyu Ho; Lee, Seung Hoon; Kwon, Soon Young; Cha, Jae Hyung; Choi, June

2017-10-01

Ototoxicity due to medications, such as aminoglycosides, is irreversible, and free radicals in the inner ear are assumed to play a major role. Because melatonin has an antioxidant property, we hypothesize that it might mitigate hair cell injury by aminoglycosides. The objective of this study was to evaluate whether melatonin has an alleviative effect on neomycin-induced hair cell injury in zebrafish (Danio rerio). Various concentrations of melatonin were administered to 5-day post-fertilization zebrafish treated with 125 μM neomycin for 1 h. Surviving hair cells within four neuromasts were compared with that of a control group. Apoptosis was assessed via terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. The changes of ultrastructure were confirmed using a scanning electron microscope. Melatonin alleviated neomycin-induced hair cell injury in neuromasts (neomycin + melatonin 100 μM: 13.88 ± 0.91 cells, neomycin only: 7.85 ± 0.90 cells; n = 10, p melatonin for 1 h in SEM findings. Melatonin is effective in alleviating aminoglycoside-induced hair cell injury in zebrafish. The results of this study demonstrated that melatonin has the potential to reduce apoptosis induced by aminoglycosides in zebrafish.

Polymeric micelles encapsulating fisetin improve the therapeutic effect in colon cancer.

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Chen, Yishan; Wu, Qinjie; Song, Linjiang; He, Tao; Li, Yuchen; Li, Ling; Su, Weijun; Liu, Lei; Qian, Zhiyong; Gong, Changyang

2015-01-14

The natural flavonoid fisetin (3,3',4',7-tetrahydroxyflavone) was discovered to possess antitumor activity, revealing its potential value in future chemotherapy. However, its poor water solubility makes it difficult for intravenous administration. In this study, the monomethyl poly(ethylene glycol)-poly(ε-caprolactone) (MPEG-PCL) copolymer was applied to prepare nanoassemblies of fisetin by a self-assembly procedure. The prepared fisetin micelles gained a mean particle size of 22 ± 3 nm, polydisperse index of 0.163 ± 0.032, drug loading of 9.88 ± 0.14%, and encapsulation efficiency of 98.53 ± 0.02%. Compared with free fisetin, fisetin micelles demonstrated a sustained and prolonged in vitro release behavior, as well as enhanced cytotoxicity, cellular uptake, and fisetin-induced apoptosis in CT26 cells. As for in vivo studies, fisetin micelles were more competent for suppressing tumor growth and prolonging survival time than free fisetin in the subcutaneous CT26 tumor model. Furthermore, histological analysis, terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, immunohistochemical detection of Ki-67, and microvessel density detection were conducted, demonstrating that fisetin micelles gained increased tumor apoptosis induction, proliferation suppression, and antiangiogenesis activities. In conclusion, we have successfully produced a MPEG-PCL-based nanocarrier encapsulating fisetin with enhanced antitumor activity.

Ulinastatin suppresses endoplasmic reticulum stress and apoptosis in the hippocampus of rats with acute paraquat poisoning

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Hai-feng Li

2015-01-01

Full Text Available Lung injury is the main manifestation of paraquat poisoning. Few studies have addressed brain damage after paraquat poisoning. Ulinastatin is a protease inhibitor that can effectively stabilize lysosomal membranes, prevent cell damage, and reduce the production of free radicals. This study assumed that ulinastatin would exert these effects on brain tissues that had been poisoned with paraquat. Rat models of paraquat poisoning were intraperitoneally injected with ulinastatin. Simultaneously, rats in the control group were administered normal saline. Hematoxylin-eosin staining showed that most hippocampal cells were contracted and nucleoli had disappeared in the paraquat group. Fewer cells in the hippocampus were concentrated and nucleoli had disappeared in the ulinastatin group. Western blot assay showed that expressions of GRP78 and cleaved-caspase-3 were significantly lower in the ulinastatin group than in the paraquat group. Immunohistochemical findings showed that CHOP immunoreactivity was significantly lower in the ulinastatin group than in the paraquat group. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining showed that the number of apoptotic cells was reduced in the paraquat and ulinastatin groups. These data confirmed that endoplasmic reticular stress can be induced by acute paraquat poisoning. Ulinastatin can effectively inhibit this stress as well as cell apoptosis, thereby exerting a neuroprotective effect.

Studying effects of Magnolol on alpha-particle induced bystander effects using PADC-film based dishes

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Wong, T.P.W. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Tse, A.K.W.; Fong, W.F. [Research and Development Division, School of Chinese Medicine, Hong Kong Baptist University, Baptist University Road, Kowloon Tong (Hong Kong); Yu, K.N., E-mail: peter.yu@cityu.edu.h [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong)

2009-10-15

Radiation-induced bystander effect refers to the biological response found in cells (called bystander cells) which are not irradiated directly by ionizing radiation but are next to cells irradiated directly by ionizing radiation. In the present paper, the effects of Magnolol, an extract from the bark of Magnolia officinalis which is used as a traditional Chinese medicine, were studied on alpha-particle induced bystander effects. In our experiments, Chinese hamster ovary (CHO) cells were cultured in PADC-film based dishes and were irradiated with low fluences of alpha particles passing through the PADC films. The precise number of cells traversed or missed by alpha particles could be determined by studying the alpha-particle tracks developed on the PADC films upon subsequent chemical etching. TdT-mediated dUTP Nick-End Labeling (TUNEL) assay was employed to analyze the biological response of bystander cells in terms of DNA strand breaks. With the pretreatment of Magnolol, the DNA strand breaks in bystander cells were reduced, which showed that the alpha-particle induced bystander effects were suppressed with the presence of Magnolol. Since Magnolol is an antioxidant which can scavenge reactive oxygen species (ROS), our results give support to that ROS play a role in the bystander signal transmission in our experiments.

Studying effects of Magnolol on alpha-particle induced bystander effects using PADC-film based dishes

International Nuclear Information System (INIS)

Wong, T.P.W.; Tse, A.K.W.; Fong, W.F.; Yu, K.N.

2009-01-01

Radiation-induced bystander effect refers to the biological response found in cells (called bystander cells) which are not irradiated directly by ionizing radiation but are next to cells irradiated directly by ionizing radiation. In the present paper, the effects of Magnolol, an extract from the bark of Magnolia officinalis which is used as a traditional Chinese medicine, were studied on alpha-particle induced bystander effects. In our experiments, Chinese hamster ovary (CHO) cells were cultured in PADC-film based dishes and were irradiated with low fluences of alpha particles passing through the PADC films. The precise number of cells traversed or missed by alpha particles could be determined by studying the alpha-particle tracks developed on the PADC films upon subsequent chemical etching. TdT-mediated dUTP Nick-End Labeling (TUNEL) assay was employed to analyze the biological response of bystander cells in terms of DNA strand breaks. With the pretreatment of Magnolol, the DNA strand breaks in bystander cells were reduced, which showed that the alpha-particle induced bystander effects were suppressed with the presence of Magnolol. Since Magnolol is an antioxidant which can scavenge reactive oxygen species (ROS), our results give support to that ROS play a role in the bystander signal transmission in our experiments.

Pacific Ciguatoxin Induces Excitotoxicity and Neurodegeneration in the Motor Cortex Via Caspase 3 Activation: Implication for Irreversible Motor Deficit.

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Asthana, Pallavi; Zhang, Ni; Kumar, Gajendra; Chine, Virendra Bhagawan; Singh, Kunal Kumar; Mak, Yim Ling; Chan, Leo Lai; Lam, Paul Kwan Sing; Ma, Chi Him Eddie

2018-01-18

Consumption of fish containing ciguatera toxins or ciguatoxins (CTXs) causes ciguatera fish poisoning (CFP). In some patients, CFP recurrence occurs even years after exposure related to CTXs accumulation. Pacific CTX-1 (P-CTX-1) is one of the most potent natural substances known that causes predominantly neurological symptoms in patients; however, the underlying pathogenies of CFP remain unknown. Using clinically relevant neurobehavioral tests and electromyography (EMG) to assess effects of P-CTX-1 during the 4 months after exposure, recurrent motor strength deficit occurred in mice exposed to P-CTX-1. We detected irreversible motor strength deficits accompanied by reduced EMG activity, demyelination, and slowing of motor nerve conduction, whereas control unexposed mice fully recovered in 1 month after peripheral nerve injury. Finally, to uncover the mechanism underlying CFP, we detected reduction of spontaneous firing rate of motor cortical neurons even 6 months after exposure and increased number of glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes. Increased numbers of motor cortical neuron apoptosis were detected by dUTP-digoxigenin nick end labeling assay along with activation of caspase 3. Taken together, our study demonstrates that persistence of P-CTX-1 in the nervous system induces irreversible motor deficit that correlates well with excitotoxicity and neurodegeneration detected in the motor cortical neurons.

Correlation between Gene Expression and Osteoarthritis Progression in Human.

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Zhong, Leilei; Huang, Xiaobin; Karperien, Marcel; Post, Janine N

2016-07-14

Osteoarthritis (OA) is a multifactorial disease characterized by gradual degradation of joint cartilage. This study aimed to quantify major pathogenetic factors during OA progression in human cartilage. Cartilage specimens were isolated from OA patients and scored 0-5 according to the Osteoarthritis Research Society International (OARSI) guidelines. Protein and gene expressions were measured by immunohistochemistry and qPCR, respectively. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were used to detect apoptotic cells. Cartilage degeneration in OA is a gradual progress accompanied with gradual loss of collagen type II and a gradual decrease in mRNA expression of SOX9, ACAN and COL2A1. Expression of WNT antagonists DKK1 and FRZB was lost, while hypertrophic markers (RUNX2, COL10A1 and IHH) increased during OA progression. Moreover, DKK1 and FRZB negatively correlated with OA grading, while RUNX2 and IHH showed a significantly positive correlation with OA grading. The number of apoptotic cells was increased with the severity of OA. Taken together, our results suggested that genetic profiling of the gene expression could be used as markers for staging OA at the molecular level. This helps to understand the molecular pathology of OA and may lead to the development of therapies based on OA stage.

Substance P reduces apoptotic cell death possibly by modulating the immune response at the early stage after spinal cord injury.

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Jiang, Mei Hua; Lim, Ji Eun; Chi, Guang Fan; Ahn, Woosung; Zhang, Mingzi; Chung, Eunkyung; Son, Youngsook

2013-10-23

Previously, we have reported that substance P (SP) enhanced functional recovery from spinal cord injury (SCI) possibly by the anti-inflammatory modulation associated with the induction of M2-type macrophages at the injured lesion. In this study, we explored the cytokine expression profiles and apoptotic cell death in the lesion site of the SCI after an immediate intravenous injection of SP. SP injection increased the levels of interleukin-4 (IL-4), IL-6, and IL-10 at day 1 after the SCI approximately by 2-, 9-, and 10-folds when compared with the control SCI, respectively. On the basis of double immunofluorescence staining with IL-10 and CD11b, activated macrophages or microglia expressing IL-10 appeared in the margin of the lesion site at day 1 only after the SP injection. This SP-mediated alteration in the lesion microenvironment was shown to be associated with the lower cell death of neuronal cells at day 1 and oligodendrocytes at day 5 by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, which was also accompanied by a decrease in caspase-3 activation. These findings suggest that SP may reduce the inflammation-induced secondary cell death, possibly through immune modulation at an early stage after the SCI.

Quercetin prevents pyrrolizidine alkaloid clivorine-induced liver injury in mice by elevating body defense capacity.

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Lili Ji

Full Text Available Quercetin is a plant-derived flavonoid that is widely distributed in nature. The present study is designed to analyze the underlying mechanism in the protection of quercetin against pyrrolizidine alkaloid clivorine-induced acute liver injury in vivo. Serum transaminases, total bilirubin analysis, and liver histological evaluation demonstrated the protection of quercetin against clivorine-induced liver injury. Terminal dUTP nick end-labeling assay demonstrated that quercetin reduced the increased amount of liver apoptotic cells induced by clivorine. Western-blot analysis of caspase-3 showed that quercetin inhibited the cleaved activation of caspase-3 induced by clivorine. Results also showed that quercetin reduced the increase in liver glutathione and lipid peroxidative product malondialdehyde induced by clivorine. Quercetin reduced the enhanced liver immunohistochemical staining for 4-hydroxynonenal induced by clivorine. Results of the Mouse Stress and Toxicity PathwayFinder RT2 Profiler PCR Array demonstrated that the expression of genes related with oxidative or metabolic stress and heat shock was obviously altered after quercetin treatment. Some of the alterations were confirmed by real-time PCR. Our results demonstrated that quercetin prevents clivorine-induced acute liver injury in vivo by inhibiting apoptotic cell death and ameliorating oxidative stress injury. This protection may be caused by the elevation of the body defense capacity induced by quercetin.

Quercetin Prevents Pyrrolizidine Alkaloid Clivorine-Induced Liver Injury in Mice by Elevating Body Defense Capacity

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Ji, Lili; Ma, Yibo; Wang, Zaiyong; Cai, Zhunxiu; Pang, Chun; Wang, Zhengtao

2014-01-01

Quercetin is a plant-derived flavonoid that is widely distributed in nature. The present study is designed to analyze the underlying mechanism in the protection of quercetin against pyrrolizidine alkaloid clivorine-induced acute liver injury in vivo. Serum transaminases, total bilirubin analysis, and liver histological evaluation demonstrated the protection of quercetin against clivorine-induced liver injury. Terminal dUTP nick end-labeling assay demonstrated that quercetin reduced the increased amount of liver apoptotic cells induced by clivorine. Western-blot analysis of caspase-3 showed that quercetin inhibited the cleaved activation of caspase-3 induced by clivorine. Results also showed that quercetin reduced the increase in liver glutathione and lipid peroxidative product malondialdehyde induced by clivorine. Quercetin reduced the enhanced liver immunohistochemical staining for 4-hydroxynonenal induced by clivorine. Results of the Mouse Stress and Toxicity PathwayFinder RT2 Profiler PCR Array demonstrated that the expression of genes related with oxidative or metabolic stress and heat shock was obviously altered after quercetin treatment. Some of the alterations were confirmed by real-time PCR. Our results demonstrated that quercetin prevents clivorine-induced acute liver injury in vivo by inhibiting apoptotic cell death and ameliorating oxidative stress injury. This protection may be caused by the elevation of the body defense capacity induced by quercetin. PMID:24905073

Hataedock treatment has preventive therapeutic effects for atopic dermatitis through skin barrier protection in Dermatophagoides farinae-induced NC/Nga mice.

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Cha, Ho-Yeol; Ahn, Sang-Hyun; Cheon, Jin-Hong; Park, Sun-Young; Kim, Kibong

2017-07-12

Hataedock treatment is traditionally used for the purpose of preventing the future skin disease by feeding herbal extracts to the newborn in traditional Chinese and Korean medicine. This study investigated the preventive therapeutic effects of Hataedock (HTD) treatment for atopic dermatitis (AD) through skin barrier protection in Dermatophagoides farinae-induced NC/Nga mice. To the HTD treatment group, the extract of Coptis japonica Makino and Glycyrrhiza uralensis Fischer, which analyzed with High Performance Liquid Chromatography (HPLC)-fingerprint for quality consistency, was administered orally to the 3-week-old mice before inducing AD. After that, Dermatophagoides farinae was applied except the control group to induce AD-like skin lesions. We confirmed the effects of HTD on morphological changes, protection of skin barrier, regulation of Th2 differentiation, inflammation regulation and induction of apoptosis through histochemistry, immunohistochemistry, and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. HTD effectively reduced edema, angiogenesis and skin lesion. HTD also increased the levels of liver X receptor (LXR) and filaggrin but decreased the level of protein kinase C (PKC) (pprotection of skin barrier. Therefore, HTD may have potential applications for alternative and preventive treatment in the management of AD. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Comparison of monomeric and polymeric horseradish peroxidase as labels in competitive ELISA for small molecule detection

International Nuclear Information System (INIS)

Li, Dongyang; Ying, Yibin; Wu, Jian; Niessner, Reinhard; Knopp, Dietmar

2013-01-01

We have developed a simple and sensitive competitive enzyme-linked immunosorbent assay (ELISA) to determine aflatoxin B1 (as a model small analyte) and using streptavidin-polymeric horseradish peroxidase complex (SApolyHRP) as a label for signal amplification. The performance of the assay was evaluated by comparing it with the classical indirect competitive ELISA using HRP labeled anti-mouse IgG as the tracer antibody. The results indicate that the SApolyHRP-based competitive ELISA exhibits a typically 2.4-fold steeper slope of the linear working range of the calibration curve compared to the monomeric HRP based classical ELISA, i.e., the sensitivity was increased. The SApolyHRP conjugate causes a typically 19-fold stronger signal generation in comparison to the traditional HRP labeled anti-mouse IgG at the same concentration (25 ng mL −1 ). Moreover, the SApolyHRP-based assay has a much wider linear range and a 3.8-fold better signal-to-noise ratio. Considering its simplicity, sensitivity and ease of operation, this competitive ELISA is considered to be a promising tool for small molecule immuno detection. (author)

Two-site immunoradiometric assay for the MB isoenzyme of creatine kinase

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Willson, V J.C.; Jones, H M; Thompson, R J [Cambridge Univ. (UK). Clinical School

1981-06-18

A two-site immunoradiometric assay for myocardial creatine kinase MB isoenzyme is described. The method utilizes immobilized anti-human creatine kinase BB antibodies and /sup 125/I-labelled anti-human creatine kinase MM antibodies and can specifically detect creatine kinase MB in the presence of approximately 1000-fold excess of creatine kinase MM or BB. Native kinase MB prepared from human heart and creatine kinase MB prepared by hybridisation of purified human creatine kinase MM and creatine kinase BB appeared to react identically in the assay. Serum estimations on patients with suspected myocardial infarction correlated with the presence of MB band on electrophoresis but preliminary results suggest that the two-site immunoradiometric assay may be more sensitive.

Solid phase 125I labelled radioimmunoassay for spermidine

International Nuclear Information System (INIS)

Zhao Shimin

1991-01-01

Using 125 I labelled monoclonal antibody against spermidine and solid phase antigen spermidine-bovine serum albumin conjugate, the radioimmunoassay for spermidine was developed. The sensitivity of this method was about 8 times higher than that of liquid phase 14 C labelled spermidine radioimmunoassay, reaching detection limit of 10 ng/ml (0.5 ng/tube). The working range of standard curve was 0-10 5 ng/ml. The new method was suitable for spermidine measurements in saliva, stomach fluid, and cerebrospinal fluid. The coefficients of variation (CV) of within and between-assay were 4% and 13%, respectively. Preliminary clinical measurements showed that the spermidine levels in saliva of cancer patients and in cerebrospinal fluid of leukemia patients were significantly elevated

Genome Editing in Mouse Spermatogonial Stem Cell Lines Using TALEN and Double-Nicking CRISPR/Cas9

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Takuya Sato

2015-07-01

Full Text Available Mouse spermatogonial stem cells (SSCs can be cultured for multiplication and maintained for long periods while preserving their spermatogenic ability. Although the cultured SSCs, named germline stem (GS cells, are targets of genome modification, this process remains technically difficult. In the present study, we tested TALEN and double-nicking CRISPR/Cas9 on GS cells, targeting Rosa26 and Stra8 loci as representative genes dispensable and indispensable in spermatogenesis, respectively. Harvested GS cell colonies showed a high targeting efficiency with both TALEN and CRISPR/Cas9. The Rosa26-targeted GS cells differentiated into fertility-competent sperm following transplantation. On the other hand, Stra8-targeted GS cells showed defective spermatogenesis following transplantation, confirming its prime role in the initiation of meiosis. TALEN and CRISPR/Cas9, when applied in GS cells, will be valuable tools in the study of spermatogenesis and for revealing the genetic mechanism of spermatogenic failure.

Application of europium(III) chelates-bonded silica nanoparticle in time-resolved immunofluorometric detection assay for human thyroid stimulating hormone

International Nuclear Information System (INIS)

Zhou Yulin; Xia Xiaohu; Xu Ye; Ke Wei; Yang Wei; Li Qingge

2012-01-01

Highlights: ► A rapid and ultrasensitive TSH immunoassay was developed using fluorescent silica nanoparticles-based TrIFA. ► The assay is of high sensitivity with short period time request. ► method can be potentially used at hospitals for daily clinical practice in hTSH screening. - Abstract: Eu(III) chelate-bonded silica nanoparticle was used as a fluorescent label to develop a highly sensitive time-resolved immunofluorometric assay (TrIFA) for human thyroid stimulating hormone (hTSH). The limit of detection of the assay calculated according to the 2SD method was 0.0007 mIU L −1 and became 0.003 mIU L −1 when serum-based matrix was used for calibrators, indicating that this TrIFA is comparable with the most sensitive assays. The linear range was from 0.005 to 100 mIU L −1 of hTSH with coefficient of variation between 1.9% and 8.3%. The correlation study using 204 blood spot samples from newborns showed that the results from this new method were coincident with that of the commercial dissociation-enhanced lanthanide fluorescence immunoassay (DELFIA) system, with a correlation coefficient of 0.938. The fluorescent nanoparticle label allows directly reading the fluorescent signal, omitting the signal development step required for the DELFIA system, and the whole procedure of this assay is fulfilled within 2 h. Thus, we developed a novel, sensitive, quantitative and simple nanoparticle label-based TrIFA assay, suitable for routine application in hTSH screening of neonatal hypothyroidism.

Application of europium(III) chelates-bonded silica nanoparticle in time-resolved immunofluorometric detection assay for human thyroid stimulating hormone

Energy Technology Data Exchange (ETDEWEB)

Zhou Yulin [Xiamen Branch of Fujian Newborn Screening Centre and Xiamen Prenatal Diagnosis Centre, Xiamen Maternal and Children' s Health Care Hospital, Xiamen, Fujian 361003 (China); Xia Xiaohu; Xu Ye; Ke Wei [Engineering Research Centre of Molecular Diagnostics Laboratory, MOE, Department of Biomedical Sciences and the Key Laboratory of the Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen, Fujian 361005 (China); Yang Wei, E-mail: weiyang@xmu.edu.cn [Engineering Research Centre of Molecular Diagnostics Laboratory, MOE, Department of Biomedical Sciences and the Key Laboratory of the Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen, Fujian 361005 (China); Li Qingge, E-mail: qgli@xmu.edu.cn [Engineering Research Centre of Molecular Diagnostics Laboratory, MOE, Department of Biomedical Sciences and the Key Laboratory of the Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen, Fujian 361005 (China)

2012-04-13

Highlights: Black-Right-Pointing-Pointer A rapid and ultrasensitive TSH immunoassay was developed using fluorescent silica nanoparticles-based TrIFA. Black-Right-Pointing-Pointer The assay is of high sensitivity with short period time request. Black-Right-Pointing-Pointer method can be potentially used at hospitals for daily clinical practice in hTSH screening. - Abstract: Eu(III) chelate-bonded silica nanoparticle was used as a fluorescent label to develop a highly sensitive time-resolved immunofluorometric assay (TrIFA) for human thyroid stimulating hormone (hTSH). The limit of detection of the assay calculated according to the 2SD method was 0.0007 mIU L{sup -1} and became 0.003 mIU L{sup -1} when serum-based matrix was used for calibrators, indicating that this TrIFA is comparable with the most sensitive assays. The linear range was from 0.005 to 100 mIU L{sup -1} of hTSH with coefficient of variation between 1.9% and 8.3%. The correlation study using 204 blood spot samples from newborns showed that the results from this new method were coincident with that of the commercial dissociation-enhanced lanthanide fluorescence immunoassay (DELFIA) system, with a correlation coefficient of 0.938. The fluorescent nanoparticle label allows directly reading the fluorescent signal, omitting the signal development step required for the DELFIA system, and the whole procedure of this assay is fulfilled within 2 h. Thus, we developed a novel, sensitive, quantitative and simple nanoparticle label-based TrIFA assay, suitable for routine application in hTSH screening of neonatal hypothyroidism.

Identifying Inhibitors of Inflammation: A Novel High-Throughput MALDI-TOF Screening Assay for Salt-Inducible Kinases (SIKs).

Science.gov (United States)

Heap, Rachel E; Hope, Anthony G; Pearson, Lesley-Anne; Reyskens, Kathleen M S E; McElroy, Stuart P; Hastie, C James; Porter, David W; Arthur, J Simon C; Gray, David W; Trost, Matthias

2017-12-01

Matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry has become a promising alternative for high-throughput drug discovery as new instruments offer high speed, flexibility and sensitivity, and the ability to measure physiological substrates label free. Here we developed and applied high-throughput MALDI TOF mass spectrometry to identify inhibitors of the salt-inducible kinase (SIK) family, which are interesting drug targets in the field of inflammatory disease as they control production of the anti-inflammatory cytokine interleukin-10 (IL-10) in macrophages. Using peptide substrates in in vitro kinase assays, we can show that hit identification of the MALDI TOF kinase assay correlates with indirect ADP-Hunter kinase assays. Moreover, we can show that both techniques generate comparable IC 50 data for a number of hit compounds and known inhibitors of SIK kinases. We further take these inhibitors to a fluorescence-based cellular assay using the SIK activity-dependent translocation of CRTC3 into the nucleus, thereby providing a complete assay pipeline for the identification of SIK kinase inhibitors in vitro and in cells. Our data demonstrate that MALDI TOF mass spectrometry is fully applicable to high-throughput kinase screening, providing label-free data comparable to that of current high-throughput fluorescence assays.

Magnetic cell labeling of primary and stem cell-derived pig hepatocytes for MRI-based cell tracking of hepatocyte transplantation.

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Dwayne R Roach

Full Text Available Pig hepatocytes are an important investigational tool for optimizing hepatocyte transplantation schemes in both allogeneic and xenogeneic transplant scenarios. MRI can be used to serially monitor the transplanted cells, but only if the hepatocytes can be labeled with a magnetic particle. In this work, we describe culture conditions for magnetic cell labeling of cells from two different pig hepatocyte cell sources; primary pig hepatocytes (ppHEP and stem cell-derived hepatocytes (PICM-19FF. The magnetic particle is a micron-sized iron oxide particle (MPIO that has been extensively studied for magnetic cell labeling for MRI-based cell tracking. ppHEP could endocytose MPIO with labeling percentages as high as 70%, achieving iron content as high as ~55 pg/cell, with >75% viability. PICM-19FF had labeling >97%, achieving iron content ~38 pg/cell, with viability >99%. Extensive morphological and functional assays indicated that magnetic cell labeling was benign to the cells. The results encourage the use of MRI-based cell tracking for the development and clinical use of hepatocyte transplantation methodologies. Further, these results generally highlight the importance of functional cell assays in the evaluation of contrast agent biocompatibility.

Biological activity analysis of native and recombinant streptokinase using clot lysis and chromogenic substrate assay.

Science.gov (United States)

Mahboubi, Arash; Sadjady, Seyyed Kazem; Mirzaei Saleh Abadi, Mohammad; Azadi, Saeed; Solaimanian, Roya

2012-01-01

DETERMINATION OF STREPTOKINASE ACTIVITY IS USUALLY ACCOMPLISHED THROUGH TWO ASSAY METHODS: a) Clot lysis, b) Chromogenic substrate assay. In this study the biological activity of two streptokinase products, namely Streptase®, which is a native product and Heberkinasa®, which is a recombinant product, was determined against the third international reference standard using the two forementioned assay methods. The results indicated that whilst the activity of Streptase® was found to be 101 ± 4% and 97 ± 5% of the label claim with Clot lysis and Chromogenic substrate assay respectively, for Heberkinasa® the potency values obtained were 42 ± 5% and 92.5 ± 2% of the label claim respectively. To shed some light on the reason for this finding, the n-terminal sequence of the streptokinase molecules present in the two products was determined. The results showed slight differences in the amino acid sequence of the recombinant product in comparison to the native one at the amino terminus. This finding supports those of other workers who found that n-terminal sequence of the streptokinase molecule can have significant effect on the activity of this protein.

Radioimmune assay of human platelet prostaglandin synthetase

International Nuclear Information System (INIS)

Roth, G.J.; Machuga, E.T.

1982-01-01

Normal platelet function depends, in part, on platelet PG synthesis. PG synthetase (cyclo-oxygenase) catalyzes the first step in PG synthesis, the formation of PGH 2 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 [ 125 I]-labelled sheep PG synthetase as antigen. The human platelet enzyme is assayed by its ability to inhibit precipitation of the [ 125 I]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 10 9 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

Receptor-based screening assays for the detection of antibiotics residues - A review.

Science.gov (United States)

Ahmed, Saeed; Ning, Jianan; Cheng, Guyue; Ahmad, Ijaz; Li, Jun; Mingyue, Liu; Qu, Wei; Iqbal, Mujahid; Shabbir, M A B; Yuan, Zonghui

2017-05-01

Consumer and regulatory agencies have a high concern to antibiotic residues in food producing animals, so appropriate screening assays of fast, sensitive, low cost, and easy sample preparation for the identification of these residues are essential for the food-safety insurance. Great efforts in the development of a high-throughput antibiotic screening assay have been made in recent years. Concerning the screening of antibiotic residue, this review elaborate an overview on the availability, advancement and applicability of antibiotic receptor based screening assays for the safety assessment of antibiotics usage (i.e. radio receptor assay, enzyme labeling assays, colloidal gold receptor assay, enzyme colorimetry assay and biosensor assay). This manuscript also tries to shed a light on the selection, preparation and future perspective of receptor protein for antibiotic residue detection. These assays have been introduced for the screening of numerous food samples. Receptor based screening technology for antibiotic detection has high accuracy. It has been concluded that at the same time, it can detect a class of drugs for certain receptor, and realize the multi-residue detection. These assays offer fast, easy and precise detection of antibiotics. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of simple immunoradiometric assays using avidin coupled to polystyrene beads as a common solid phase

International Nuclear Information System (INIS)

Jyotsna, N.; Singh, Y.; Chouthkanthiwar, V.; Paradkar, S.; Sivaprasad, N.

1998-01-01

In this paper, we describe the preparation and application of avidin coupled polystyrene beads as a common solid phase for use in immunoradiometric assays (IRMAs). The assay system is based on two matched commercial monoclonal antibodies, of which, the capture antibody is biotinylated using biotinamidocaproate N-hydroxysuccinimide ester and the detection antibody is radiolabeled with 125 I by conventional Chloramine-T method. Avidin was immobilized on the polystyrene beads through a primary coat of bovine serum albumin using glutaraldhyde activation method. Various factors, such as concentration of reagents, incubation time, etc. were optimised to obtain a simple assay protocol consisting of only two pipetting steps, namely, that of a mixture of the two labelled antibodies (radiolabelled and biotinylated) and of the standard or sample. The advantage of the Avidin-Biotin system is the improved sensitivity, economy of antibody and the possibility to use a common solid phase in assays for different analytes. Using the polystyrene beads along with the novel decanting device, it has been possible to achieve the convenience of the 'coated-tube' technology without the expensive automation necessary for large scale preparation of antibody coated tubes. This protocol has been successfully applied to Prolactin, LH and FSH assays. The sensitivity of the Prolactin assay is 8μIU/mL (0.3 ng/mL), that of the FSH assay is 1mIU/mL and that of the LH assay is 0.9 mIU/mL. The intra-assay and inter-assay variations were <10%. Shelf life of the avidin coupled beads was found to be about 8 months and that of the biotin labelled antibodies up to 18 months. (author)

Echinophora platyloba DC (Apiaceae crude extract induces apoptosis in human prostate adenocarcinoma cells (PC 3

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Fatemeh Zare Shahneh

2014-10-01

Full Text Available Background: Prostate cancer is the second leading malignancy worldwide and the second prominent cause of cancer-related deaths among men. Therefore, there is a serious necessity for finding advanced alternative therapeutic measures against this lethal malignancy. In this article, we report the cytotoxicity and the mechanism of cell death of the methanolic extract prepared from Echinophora platyloba DC plant against human prostate adenocarcinoma PC 3 cell line and Human Umbilical Vein Endothelial Cells HUVEC cell line. Methods: Cytotoxicity and viability of the methanolic extract were assessed by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay and dye exclusion assay. Cell death enzyme-linked immunosorbent assay (ELISA was employed to quantify the nucleosome production resulting from nuclear DNA fragmentation during apoptosis and determine whether the mechanism involves induction of apoptosis or necrosis. The cell death was identified as apoptosis using terminal deoxynucleotidyl transferase (TdT-mediated dUTP nick end labeling (TUNEL assay and DNA fragmentation gel electrophoresis. Results: E. platyloba could decrease cell viability in malignant cells in a dose- and time-dependent manner. The IC50 values against PC 3 were determined as 236.136 ± 12.4, 143.400 ± 7.2, and 69.383 ± 1.29 μg/ml after 24, 36, and 48 h, respectively, but there was no significant activity in HUVEC normal cell (IC50 > 800 μg/ml. Morphological characterizations and DNA laddering assay showed that the methanolic extract treated cells displayed marked apoptotic characteristics such as nuclear fragmentation, appearance of apoptotic bodies, and DNA laddering fragment. Increase in an early apoptotic population was observed in a dose-dependent manner. PC 3 cell death elicited by the extract was found to be apoptotic in nature based a clear indication of TUNEL assay and gel electrophoresis DNA fragmentation, which is a hallmark of apoptosis

Investigation of the relationship between venticular fibrillation duration and cardiac/neurological damage in a rabbit model of electrically induced arrhythmia.

Science.gov (United States)

Hu, Chun-Lin; Wei, Hong-Yan; Liu, Zi-You; Li, Xing; Liao, Xiao-Xing; Li, Yu-Jie; Zhan, Hong; Jing, Xiao-Li; Xiong, Yan; Liu, Yan-Yan; Wu, Gui-Fu

2010-12-01

To establish a simple, economic, and reliable alternating current (AC)-induced cardiac arrest (ACCA) model in rabbits for cardiopulmonary cerebral resuscitation research. Ventricular fibrillation was induced in 27 New Zealand rabbits by external transthoracic AC, which were randomly divided into three groups according to the duration of untreated ACCA (ACCA-3 minutes, ACCA-5 minutes, and ACCA-8 minutes). After ACCA, all animals received cardiopulmonary resuscitation for 2 minutes and subsequent defibrillation until return of spontaneous circulation (ROSC). The troponin I levels were measured at 4 hours after ROSC. Animals died spontaneously or were killed at 72 hours after ROSC. The hippocampus were removed and fixed in 3% formalin. TdT-mediated dUTP-biotin nick end labeling and Nissl stainings were performed in 10-μm thickness coronal sections. Furthermore, two rabbits (without induction of ventricular fibrillation, cardiopulmonary resuscitation, and defibrillation) served as normal control group. Mean survival times after ROSC were 48.57 hours ± 24.70 hours, 18.0 hours ± 15.13 hours, and 3.88 hours ± 2.39 hours for groups ACCA-3 minutes, ACCA-5 minutes, and ACCA-8 minutes, respectively. Survival was significantly different between ACCA-3 minutes and other two groups (p = 0.002 and p = 0.01). Neuronal necrosis and apoptosis were found in the hippocampus CA1, CA2, and CA3 areas of group ACCA-3 minutes. In contrast, neuronal necrosis and TdT-mediated dUTP-biotin nick end labeling positive cells were fewer in control animals. The rabbits in group ACCA-3 minutes had significant neuronal damage with apoptosis in hippocampus CA1, CA2, and CA3 areas at 72 hours after ROSC and survived longer than those in other groups. The model we describe may be a simple, economic, and reliable model for experimental investigation on cardiopulmonary cerebral resuscitation.

Thrombospondin-1 expression may be implicated in liver atrophic mechanism due to obstructed portal venous flow.

Science.gov (United States)

Hayashi, Hiromitsu; Kuroki, Hideyuki; Higashi, Takaaki; Takeyama, Hideaki; Yokoyama, Naomi; Okabe, Hirohisa; Nitta, Hidetoshi; Beppu, Toru; Takamori, Hiroshi; Baba, Hideo

2017-07-01

Liver is an amazing organ that can undergo regenerative and atrophic changes inversely, depending on blood flow conditions. Although the regenerative mechanism has been extensively studied, the atrophic mechanism remains to be elucidated. To assess the molecular mechanism of liver atrophy due to reduced portal blood flow, we analyzed the gene expressions between atrophic and hypertrophic livers induced by portal vein embolization in three human liver tissues using microarray analyses. Thrombospondin (TSP)-1 is an extracellular protein and a negative regulator of liver regeneration through its activation of the transforming growth factor-β/Smad signaling pathway. TSP-1 was extracted as the most upregulated gene in atrophic liver compared to hypertrophic liver due to portal flow obstruction in human. Liver atrophic and hypertrophic changes were confirmed by HE and proliferating cell nuclear antigen staining and terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling. In an in vivo model with portal ligation, TSP-1 and phosphorylated Smad2 expression were continuously induced at 6 h and thereafter in the portal ligated liver, whereas the induction was transient at 6 h in the portal non-ligated liver. Indeed, while cell proliferation represented by proliferating cell nuclear antigen expression at 48 h was induced in the portal ligated liver, the sinusoidal dilatation and hepatocyte cell death with terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling was detectable at 48 h in the portal ligated liver. Obstructed portal flow induces persistent TSP-1 expression and transforming growth factor-β/Smad signal activation in atrophic liver. Thrombospondin-1 may be implicated in the liver atrophic change due to obstructed portal flow as a pro-atrophic factor. © 2016 The Japan Society of Hepatology.

Pre- and posttreatment with edaravone protects CA1 hippocampus and enhances neurogenesis in the subgranular zone of dentate gyrus after transient global cerebral ischemia in rats.

Science.gov (United States)

Lei, Shan; Zhang, Pengbo; Li, Weisong; Gao, Ming; He, Xijing; Zheng, Juan; Li, Xu; Wang, Xiao; Wang, Ning; Zhang, Junfeng; Qi, Cunfang; Lu, Haixia; Chen, Xinlin; Liu, Yong

2014-01-01

Edaravone is clinically used for treatment of patients with acute cerebral infarction. However, the effect of double application of edaravone on neurogenesis in the hippocampus following ischemia remains unknown. In the present study, we explored whether pre- and posttreatment of edaravone had any effect on neural stem/progenitor cells (NSPCs) in the subgranular zone of hippocampus in a rat model of transient global cerebral ischemia and elucidated the potential mechanism of its effects. Male Sprague-Dawley rats were divided into three groups: sham-operated (n = 15), control (n = 15), and edaravone-treated (n = 15) groups. Newly generated cells were labeled by 5-bromo-2-deoxyuridine. Immunohistochemistry was used to detect neurogenesis. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling was used to detect cell apoptosis. Reactive oxygen species (ROS) were detected by 2,7-dichlorofluorescien diacetate assay in NSPCs in vitro. Hypoxia-inducible factor-1α (HIF-1α) and cleaved caspase-3 proteins were quantified by western blot analysis. Treatment with edaravone significantly increased the number of NSPCs and newly generated neurons in the subgranular zone (p edaravone also decreased apoptosis of NSPCs (p edaravone significantly decreased ROS generation and inhibited HIF-1α and cleaved caspase-3 protein expressions. These findings indicate that pre- and posttreatment with edaravone enhances neurogenesis by protecting NSPCs from apoptosis in the hippocampus, which is probably mediated by decreasing ROS generation and inhibiting protein expressions of HIF-1α and cleaved caspase-3 after cerebral ischemia. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Pre- and Posttreatment With Edaravone Protects CA1 Hippocampus and Enhances Neurogenesis in the Subgranular Zone of Dentate Gyrus After Transient Global Cerebral Ischemia in Rats

Directory of Open Access Journals (Sweden)

Shan Lei

2014-11-01

Full Text Available Edaravone is clinically used for treatment of patients with acute cerebral infarction. However, the effect of double application of edaravone on neurogenesis in the hippocampus following ischemia remains unknown. In the present study, we explored whether pre- and posttreatment of edaravone had any effect on neural stem/progenitor cells (NSPCs in the subgranular zone of hippocampus in a rat model of transient global cerebral ischemia and elucidated the potential mechanism of its effects. Male Sprague-Dawley rats were divided into three groups: sham-operated (n = 15, control (n = 15, and edaravone-treated (n = 15 groups. Newly generated cells were labeled by 5-bromo-2-deoxyuridine. Immunohistochemistry was used to detect neurogenesis. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling was used to detect cell apoptosis. Reactive oxygen species (ROS were detected by 2,7-dichlorofluorescien diacetate assay in NSPCs in vitro. Hypoxia-inducible factor-1α (HIF-1α and cleaved caspase-3 proteins were quantified by western blot analysis. Treatment with edaravone significantly increased the number of NSPCs and newly generated neurons in the subgranular zone (p < .05. Treatment with edaravone also decreased apoptosis of NSPCs (p < .01. Furthermore, treatment with edaravone significantly decreased ROS generation and inhibited HIF-1α and cleaved caspase-3 protein expressions. These findings indicate that pre- and posttreatment with edaravone enhances neurogenesis by protecting NSPCs from apoptosis in the hippocampus, which is probably mediated by decreasing ROS generation and inhibiting protein expressions of HIF-1α and cleaved caspase-3 after cerebral ischemia.

Effect of long-term culture of mouse embryonic stem cells under low oxygen concentration as well as on glycosaminoglycan hyaluronan on cell proliferation and differentiation.

Science.gov (United States)

Ramírez, M Á; Pericuesta, E; Yáñez-Mó, M; Palasz, A; Gutiérrez-Adán, A

2011-02-01

Maintaining undifferentiated stem cells in defined conditions is of critical importance to improve their in vitro culture. We have evaluated the effects of culturing mouse stem (mES) cells under physiological oxygen concentration as well as by replacing fibroblast feeder layer (mEF) with gelatin or glycosaminoglycan hyaluronan (HA), on cell proliferation and differentiation. After 3 days culture or after long-term cell culture under different conditions, levels of apoptotic cell death were determined by cell cycle and TUNEL (TdT-mediated dUTP nick end labelling) assays and levels of cell proliferation by CFSE (5-(and-6)-carboxyfluorescein diacetate succinimidyl ester) labelling. We assessed spontaneous differentiation into cardiomyocytes and mRNA expression of pluripotency and differentiation biomarkers. After 3 days culture under hypoxic conditions, levels of proliferation and apoptosis of mES cells were higher, in correlation with increase in intracellular reactive oxygen species. However, when cells were continuously grown for 1 month under those conditions, the level of apoptosis was, in all cases, under 4%. Hypoxia reduced spontaneous differentiation of mES into cardiomyocytes. Long-term culture on HA was more effective in maintaining the pluripotent state of the mES cells when compared to that on gelatin. Level of terminal differentiation was highest on mEF, intermediate on HA and lowest on gelatin. Our data suggest that hypoxia is not necessary for maintaining pluripotency of mES cells and appeared to be detrimental during ES differentiation. Moreover, HA may offer a valuable alternative for long-term culture of mES cells in vitro. © 2010 Blackwell Publishing Ltd.

A pigeon crop sac radioreceptor assay for prolactin

International Nuclear Information System (INIS)

Forsyth, I.A.; Buntin, J.D.; Nicoll, C.S.

1978-01-01

Ovine prolactin, labelled with 125 I by either lactoperoxidase or a mild chloramine T method, was bound to receptors from the pigeon crop sac mucosa cells of prolactin-injected pigeons. Binding was demonstrated in a crude homogenate of mucosal cells removed from the crop by scraping and in a subcellular fraction in which 5'- nucleotidase activity was enhanced two- to three-fold. The binding was specific, dependent on time, temperature and the concentration of receptors and had a dissociation constant of 7 x 10 -10 mol/l. The binding capacity of the crop tissue was 71 fmol/mg membrane protein. Nine purified preparations of prolactin from four species were assayed by local pigeon crop sac bioassay and by radioreceptor assay. The two methods were highly correlated (r = 0.934). The regression equation was radioreceptor assay = 1.22 bioassay - 0.18 indicating a 1:1 correspondence between the two methods for prolactin purified from sheep, rat, horse and pig anterior pituitary glands. (author)

Nano-immunosafety: issues in assay validation

International Nuclear Information System (INIS)

Boraschi, Diana; Italiani, Paola; Oostingh, Gertie J; Duschl, Albert; Casals, Eudald; Puntes, Victor F; Nelissen, Inge

2011-01-01

Assessing the safety of engineered nanomaterials for human health must include a thorough evaluation of their effects on the immune system, which is responsible for defending the integrity of our body from damage and disease. An array of robust and representative assays should be set up and validated, which could be predictive of the effects of nanomaterials on immune responses. In a trans-European collaborative work, in vitro assays have been developed to this end. In vitro tests have been preferred for their suitability to standardisation and easier applicability. Adapting classical assays to testing the immunotoxicological effects of nanoparticulate materials has raised a series of issues that needed to be appropriately addressed in order to ensure reliability of results. Besides the exquisitely immunological problem of selecting representative endpoints predictive of the risk of developing disease, assay results turned out to be significantly biased by artefactual interference of the nanomaterials or contaminating agents with the assay protocol. Having addressed such problems, a series of robust and representative assays have been developed that describe the effects of engineered nanoparticles on professional and non-professional human defence cells. Two of such assays are described here, one based on primary human monocytes and the other employing human lung epithelial cells transfected with a reporter gene.

Processive nicking activity of T4 endonuclease V on UV-irradiated chromatin

International Nuclear Information System (INIS)

Gruskin, E.A.; Lloyd, R.S.

1986-01-01

T4 endonuclease V initiates the excision repair of pyrimidine dimers in UV-irradiated T4 infected E. coli cells. The pyrimidine dimer specific nicking activity of T4 endonuclease V functions by a processive scanning on UV-irradiated DNA. Previously it has been demonstrated that introduction of endonuclease V into repair-deficient human cells causes a restoration of UV survival in these cells. This demonstrates that endonuclease V is competent to incise mammalian DNA at the site of pyrimidine dimers. In order to assess the ability of endonuclease V to act processively on DNA associated as chromatin, minichromosomes were prepared for use as a substrate. Form I DNA was reconstituted with H3, H4 +/- H1 histones by sequential dialysis steps from 2.0 M NaCl to 50 mM NaCl. Time course reactions were performed with minichromosomes containing 10 and 25 dimers per molecule. In each case the rate of disappearance of form I DNA which was associated as chromatin was decreased relative to that of naked form I DNA. Concurrent with that observation, the rate and extent of appearance of form III DNA was increased with the DNA in minichromosomes relative to naked DNA. This is diagnostic of an enhancement of processivity. The inclusion of H1 in the minichromosomes resulted in a slight additional increase in processivity relative to minichromosomes consisting only of H3 and H4

Identification of special fragments containing the 5' end of polivirus RNA after ribonuclease III digestion

Energy Technology Data Exchange (ETDEWEB)

Harris, T.J.R.; Dunn, J.J.; Wimmer, E.

1978-11-01

The small protein (VPg) covalently linked to the 5' end of the poliovirus Type 1 (PV-1) RNA has been labeled in vitro with /sup 125/I usingthe Bolton and Hunter reagent. The RNA is not degraded under the conditions used and nearly all the label enters VPg and not the polynucleotide chain. When this /sup 125/I-labeled RNA is cleaved with RNase III at low monovalent salt concentrations, one major /sup 125/I-labeled fragment, approximately 100 nucleotides long, is produced. The corresponding fragment from similar digests of /sup 32/P-labeled RNA has also been identified. The /sup 32/P-labeled fragment changes electrophoretic mobility after protease treatment indicating that it contains VPg. Furthermore, the RNase T1 oligonucleotide known to be at the 5' terminus of poliovirus RNA is found in T1 digests of the purified fragment. These results confirm that the fragment is derived from the 5' end of the RNA. This fragment will be useful in studies concerning the initiation of protein synthesis during poliovirus infection.

Evaluation of a new free-thyroxin assay

International Nuclear Information System (INIS)

Welby, M.L.; Guthrie, L.; Reilly, C.P.

1981-01-01

The Amerlex Free Thyroxin (T 4 ) Radioimmunoassay Kit (Amersham International Ltd.) is a new direct equilibrium radioimmunoassay for free T 4 based on an antiserum with very high affinity for T 4 , and a unique 125 l-labeled T 4 analog as tracer. It is a very simple single-tube radioimmunoassay, making use of Amerlex particles to separate antibody-bound from free species. Interassay precision (CV) is 3.7% at 13 pmol/L and 2.3% at 30 pmol/L; within-assay precision is 4.2% at 21 pmol/L. The reference interval is 11-22 pmol/L. The assay did not misclassify any patients tested who had untreated myxedema or untreated thyrotoxicosis. The free T 4 assay excelled both the free T 4 index and the T 4 /T 4 -binding globulin ratio in correcting for increased thyroxin-binding globulin from pregnancy, and it was better than the index but not better than the ratio in correcting for increased thyroxin-binding globulin in users of oral contraceptives

Effect of ionizing radiation on apoptosis in mouse Peyer's patches

International Nuclear Information System (INIS)

Liu Jiamei; Chen Dong; Liu Shuzheng

1999-01-01

The relationship of time-effect and dose-effect of apoptosis in mouse Peyer's patches after whole body irradiation (WBI) with different doses of X-rays was studied by the method of TdT-mediated dUTP nick end labelling (TUNEL). The results showed that the number of TUNEL positive cells in mouse Peyer's patches were significantly increased following WBI with 2 Gy irradiation, While the number of TUNEL positive cells were decreased after WBI with doses of 0.05 Gy and 0.075 Gy X-rays. the results support the view that 2 Gy irradiation promote the apoptosis of immune cells and the low doses of radiation suppress the apoptosis of immune cells

Labelling of food: A challenge for many

Directory of Open Access Journals (Sweden)

Henderikx Frans

2017-01-01

Full Text Available Background: In food marketing, there is a trend towards artisanal, traditional “honest” food, and simultaneously to good looking, long lasting, multi-purpose food with a clean label. In addition, marketeers like to upgrade the image of the food, including the label, using various digital techniques. This can produce (unintended non-conformities with the current food law on labelling, which in this review, refers to Regulation (EU No 1169/2011 (European Union, 2011. Food and meat labelling have been subjected to increased regulation in the recent years, sometimes after scandals (horse-gate, food fraud, sometimes due to wishes of consumer organisations (nutritional information and sometimes after the introduction of new types of ingredients (sweeteners, phytosterols, nanomaterials. Scope and approach: This review provides information about food labelling. Some experiences gathered by food inspectorate personnel in practice, with reference to the literature data, positive aspects, main problems and trends are discussed. Key findings and conclusion: Food labelling is a complex requirement, with the general demands written down in the harmonized regulation (European Union, 2011. Foods sold by e-commerce must also follow these same regulations. However, many food labels on the market show smaller and/or bigger deviations from the legal requirements, which should be appropriately addressed by the food manufacturers or packers, but also by the competent authorities. Even training of consumers seems to be needed, since all this information is, in the end, intended for consumers to aptly utilise.

Novel multiplexed assay for identifying SH2 domain antagonists of STAT family proteins.

Science.gov (United States)

Takakuma, Kazuyuki; Ogo, Naohisa; Uehara, Yutaka; Takahashi, Susumu; Miyoshi, Nao; Asai, Akira

2013-01-01

Some of the signal transducer and activator of transcription (STAT) family members are constitutively activated in a wide variety of human tumors. The activity of STAT depends on their Src homology 2 (SH2) domain-mediated binding to sequences containing phosphorylated tyrosine. Thus, antagonizing this binding is a feasible approach to inhibiting STAT activation. We have developed a novel multiplexed assay for STAT3- and STAT5b-SH2 binding, based on amplified luminescent proximity homogeneous assay (Alpha) technology. AlphaLISA and AlphaScreen beads were combined in a single-well assay, which allowed the binding of STAT3- and STAT5b-SH2 to phosphotyrosine peptides to be simultaneously monitored. Biotin-labeled recombinant human STAT proteins were obtained as N- and C-terminal deletion mutants. The spacer length of the DIG-labeled peptide, the reaction time, and the concentration of sodium chloride were optimized to establish a HTS system with Z' values of greater than 0.6 for both STAT3- and STAT5b-SH2 binding. We performed a HTS campaign for chemical libraries using this multiplexed assay and identified hit compounds. A 2-chloro-1,4-naphthalenedione derivative, Compound 1, preferentially inhibited STAT3-SH2 binding in vitro, and the nuclear translocation of STAT3 in HeLa cells. Initial structure activity relationship (SAR) studies using the multiplexed assay showed the 3-substituent effect on both the activity and selectivity of STAT3 and STAT5b inhibition. Therefore, this multiplexed assay is useful for not only searching for potential lead compounds but also obtaining SAR data for developing new STAT3/STAT5b inhibitors.

A new gaseous imaging detector for the assay of lymphocyte cultures

International Nuclear Information System (INIS)

Bateman, J.E.; Joyce, A.; Knight, S.C.; Bedford, P.

1991-01-01

Tritium-labelled cell cultures used in studies of lymphocyte proliferation at the Clinical Research Centre are blotted in arrays of 10x6 spots spaced at 6 mm. An imaging detector based on the differential induction signals produced at a central amplifying electrode has been developed for the imaging and assay of these blots. A spatial resolution ≅ 2.5 mm FWHM attained over the aperture of 60 mmx36mm enables the individual spots to be reliably counted. Data is captured in a PC/AT at rates which permit an assay to be completed in typically 30-60 min. The simplicity of both the detector and the readout electronics leads to a low cost system. Images and assay results are presented. (orig.)

Coherent spectral amplitude coded label detection for DQPSK payload signals in packet-switched metropolitan area networks

DEFF Research Database (Denmark)

Osadchiy, Alexey Vladimirovich; Guerrero Gonzalez, Neil; Jensen, Jesper Bevensee

2011-01-01

We report on an experimental demonstration of a frequency swept local oscillator-based spectral amplitude coding (SAC) label detection for DQPSK signals after 40km of fiber transmission. Label detection was performed for a 10.7Gbaud DQPSK signal labeled with a SAC label composed of four......-frequency tones with 500MHz spectral separation. Successful label detection and recognition is achieved with the aid of digital signal processing that allows for substantial reduction of the complexity of the detection optical front-end....

A two-site immunoradiometric assay for the MB isoenzyme of creatine kinase

International Nuclear Information System (INIS)

Willson, V.J.C.; Jones, H.M.; Thompson, R.J.

1981-01-01

A two-site immunoradiometric assay for myocardial creatine kinase MB isoenzyme is described. The method utilizes immobilized anti-human creatine kinase BB antibodies and 125 I-labelled anti-human creatine kinase MM antibodies and can specifically detect creatine kinase MB in the presence of approximately 1000-fold excess of creatine kinase MM or BB. Native kinase MB prepared from human heart and creatine kinase MB prepared by hybridisation of purified human creatine kinase MM and creatine kinase BB appeared to react identically in the assay. Serum estimations on patients with suspected myocardial infarction correlated with the presence of MB band on electrophoresis but preliminary results suggest that the two-site immunoradiometric assay may be more sensitive. (Auth.)

Analysis of chromium-51 release assay data using personal computer spreadsheet software

International Nuclear Information System (INIS)

Lefor, A.T.; Steinberg, S.M.; Wiebke, E.A.

1988-01-01

The Chromium-51 release assay is a widely used technique to assess the lysis of labeled target cells in vitro. We have developed a simple technique to analyze data from Chromium-51 release assays using the widely available LOTUS 1-2-3 spreadsheet software. This package calculates percentage specific cytotoxicity and lytic units by linear regression. It uses all data points to compute the linear regression and can determine if there is a statistically significant difference between two lysis curves. The system is simple to use and easily modified, since its implementation requires neither knowledge of computer programming nor custom designed software. This package can help save considerable time when analyzing data from Chromium-51 release assays

Quantitative assay for the measurement of immune responses directed against the human placenta

Energy Technology Data Exchange (ETDEWEB)

Davies, M; Sutcliffe, R G [Glasgow Univ. (UK)

1982-02-12

A quantitative in vitro immune assay based on the classical chromium release assay has been developed to detect immune responses directed against alien antigens expressed by the developing foetus and present on the maternal-facing surface of the human placenta. A plasma membrane fraction from the surface of the placenta was prepared and the vesicles thus formed were radiolabelled with /sup 51/Cr. The /sup 51/Cr-labelled vesicles, by various criteria, were found to be suitable for use as targets in a release assay. Further, by means of experimentally immunised animals, the target membranes were shown to be capable of detecting both cellular and humoral anti-placental activity.

Solid-phase receptor-based assay for the detection of cyclic imines by chemiluminescence, fluorescence, or colorimetry.

Science.gov (United States)

Rodríguez, Laura P; Vilariño, Natalia; Molgó, Jordi; Aráoz, Rómulo; Antelo, Alvaro; Vieytes, Mercedes R; Botana, Luis M

2011-08-01

The spirolides and gymnodimines are marine phycotoxins included in the group of cyclic imines. The toxicity of these compounds to humans is still unknown, although their toxicity by intraperitoneal injection in rodents is very high. A receptor-based method was developed using the competition of the 13-desmethyl spirolide C with biotin-labeled α-bungarotoxin for binding to nicotinic acetylcholine receptors and the immobilization of the α-bungarotoxin-receptor complex on streptavidin-coated surfaces. The quantification of the immobilized receptor can be achieved using a specific antibody. Finally, after the addition of a secondary antibody labeled with horseradish peroxidase, three alternative substrates of this enzyme generate a chemiluminescent, fluorescent, or colorimetric signal. The assay performs well in shellfish extracts and the detection range is 5-150 nM of 13-desmethyl spirolide C in shellfish extracts, which is at least 5 times more sensitive than the existing fluorescence polarization assay. This assay can also detect gymnodimine, although with 10 times lower sensitivity than the spirolide. The detection of cyclic imines with microplate assays would be useful for screening purposes in order to reduce the number of samples to be processed by bioassays or analytical methods.

Development of an enzyme-linked immunosorbent assay (ELISA)-like fluorescence assay to investigate the interactions of glycosaminoglycans to cells

Energy Technology Data Exchange (ETDEWEB)

Boucas, Rodrigo Ippolito [Disciplina de Biologia Molecular, Departamento de Bioquimica, Universidade Federal de Sao Paulo, SP (Brazil); Trindade, Edvaldo S. [Disciplina de Biologia Molecular, Departamento de Bioquimica, Universidade Federal de Sao Paulo, SP (Brazil); Departamento de Biologia Celular, Universidade Federal do Parana, Curitiba, Parana (Brazil); Tersariol, Ivarne L.S. [Disciplina de Biologia Molecular, Departamento de Bioquimica, Universidade Federal de Sao Paulo, SP (Brazil); Centro Interdisciplinar de Investigacao Bioquimica, Universidade de Mogi das Cruzes, Mogi das Cruzes, SP (Brazil); Dietrich, Carl P. [Disciplina de Biologia Molecular, Departamento de Bioquimica, Universidade Federal de Sao Paulo, SP (Brazil); Nader, Helena B. [Disciplina de Biologia Molecular, Departamento de Bioquimica, Universidade Federal de Sao Paulo, SP (Brazil)], E-mail: hbnader.bioq@epm.br

2008-06-23

Sulfated glycosaminoglycans were labeled with biotin to study their interaction with cells in culture. Thus, heparin, heparan sulfate, chondroitin 4-sulfate, chondroitin 6-sulfate and dermatan sulfate were labeled using biotin-hydrazide, under different conditions. The structural characteristics of the biotinylated products were determined by chemical (molar ratios of hexosamine, uronic acid, sulfate and biotin) and enzymatic methods (susceptibility to degradation by chondroitinases and heparitinases). The binding of biotinylated glycosaminoglycans was investigated both in endothelial and smooth muscle cells in culture, using a novel time resolved fluorometric method based on interaction of europium-labeled streptavidin with the biotin covalently linked to the compounds. The interactions of glycosaminoglycans were saturable and number of binding sites could be obtained for each individual compound. The apparent dissociation constant varied among the different glycosaminoglycans and between the two cell lines. The interactions of the biotinylated glycosaminoglycans with the cells were also evaluated using confocal microscopy. We propose a convenient and reliable method for the preparation of biotinylated glycosaminoglycans, as well as a sensitive non-competitive fluorescence-based assay for studies of the interactions and binding of these compounds to cells in culture.

Development of an enzyme-linked immunosorbent assay (ELISA)-like fluorescence assay to investigate the interactions of glycosaminoglycans to cells

International Nuclear Information System (INIS)

Boucas, Rodrigo Ippolito; Trindade, Edvaldo S.; Tersariol, Ivarne L.S.; Dietrich, Carl P.; Nader, Helena B.

2008-01-01

Sulfated glycosaminoglycans were labeled with biotin to study their interaction with cells in culture. Thus, heparin, heparan sulfate, chondroitin 4-sulfate, chondroitin 6-sulfate and dermatan sulfate were labeled using biotin-hydrazide, under different conditions. The structural characteristics of the biotinylated products were determined by chemical (molar ratios of hexosamine, uronic acid, sulfate and biotin) and enzymatic methods (susceptibility to degradation by chondroitinases and heparitinases). The binding of biotinylated glycosaminoglycans was investigated both in endothelial and smooth muscle cells in culture, using a novel time resolved fluorometric method based on interaction of europium-labeled streptavidin with the biotin covalently linked to the compounds. The interactions of glycosaminoglycans were saturable and number of binding sites could be obtained for each individual compound. The apparent dissociation constant varied among the different glycosaminoglycans and between the two cell lines. The interactions of the biotinylated glycosaminoglycans with the cells were also evaluated using confocal microscopy. We propose a convenient and reliable method for the preparation of biotinylated glycosaminoglycans, as well as a sensitive non-competitive fluorescence-based assay for studies of the interactions and binding of these compounds to cells in culture

Identification of the D-1 dopamine receptor subunit in rat striatum after photoaffinity labeling

Energy Technology Data Exchange (ETDEWEB)

Kuno, T; Tanaka, C [Kobe Univ. (Japan). School of Medicine

1982-12-28

When rat striatal membranes, photolabeled with (/sup 3/H)dopamine under assay conditions similar to those used for dopamine-sensitive adenylate cyclase, were subjected to sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis, several radioactively labeled bands appeared. Labeling of these bands was reduced in the presence of non-radioactive dopamine during photolysis, but was unaffected by the presence of sulpiride. Haloperidol preferentially reduced the labeling of the main band which had a molecular weight of about 57,000 rather than the other weakly labeled bands. Labeling of this 57,000 dalton protein was not apparent when rat cerebellar membranes were used and was markedly eliminated by kainic acid-induced lesions that destroyed the intrastriatal nerve cell bodies. These results indicate that this 57,000 dalton protein is the binding subunit of the D-1 dopamine receptor.

Mung Bean nuclease mapping of RNAs 3' end

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Barbieri Rainer

2009-05-01

Full Text Available Abstract A method is described that allows an accurate mapping of 3' ends of RNAs. In this method a labeled DNA probe, containing the presumed 3' end of the RNA under analysis is allowed to anneals to the RNA itself. Mung-bean nuclease is then used to digest single strands of both RNA and DNA. Electrophoretic fractionation of "protected" undigested, labeled DNA is than performed using a sequence reaction of a known DNA as length marker. This procedure was applied to the analysis of both a polyA RNA (Interleukin 10 mRNA and non polyA RNAs (sea urchin 18S and 26S rRNAs. This method might be potentially relevant for the evaluation of the role of posttrascriptional control of IL-10 in the pathogenesis of the immune and inflammatory mediated diseases associated to ageing. This might allow to develop new strategies to approach to the diagnosis and therapy of age related diseases.

Affinity labeling of the carbohydrate binding site of the lectin discoidin I using a photoactivatable radioiodinated monosaccharide

International Nuclear Information System (INIS)

Kohnken, R.E.; Berger, E.A.

1987-01-01

N-(4-Azidosalicyl) galactosamine (GalNASA), a photoactivatable, radioiodinatable analog of N-acetylgalactosamine (GalNAc), has been prepared and characterized. The authors have used this reagent for labeling of the carbohydrate binding site of discoidin I, an endogenous lectin produced by Dictyostelium discoideum. GalNASA behaved as a ligand for discoidin I, as judged by its ability to compete in an assay measuring the carbohydrate binding activity of discoidin I. In this assay, it exhibited a K/sub i,app/ of 800 μM, comparable to that of GalNAc. The K/sub i,app/ of GalNASA decreased to 40 μm upon prior photolysis with ultraviolet light. In contrast, N-(4-azidosalicyl) ethanolamine produced no inhibition of carbohydrate binding regardless of photolysis. Covalent labeling of discoidin I with 125 I-GalNASA was entirely dependent upon ultraviolet light. A portion of labeling, representing 40-60% of the total, was sensitive to reagents which were known to inhibit carbohydrate binding by discoidin I, including GalNAc, asialofetuin, and ethyl-enediaminetetraacetic acid. The carbohydrate-sensitive fraction of discoidin I photolabeling with 125 I-GalNASA exhibited a K/sub d/ of 15-40 μM, in agreement with the K/sub i,app/ of prephotolyzed GalNASA observed in the carbohydrate binding assay. Partial proteolytic digestion of photolabeled discoidin I revealed specific fragments whose labeling was completely blocked by GalNAc. This indicated that the location of carbohydrate-sensitive labeling within the structure of discoidin I was restricted. One particular tryptic fragment, Tr1, was examined in detail. These data suggest that Tr1 is derived from the carbohydrate binding site of discoidin I

Novel double-isotope technique for enzymatic assay of catecholamines, permitting high precision, sensitivity and plasma sample capacity

International Nuclear Information System (INIS)

Brown, M.J.; Jenner, D.A.

1981-01-01

A novel use of a double-isotope method is described which allows radioenzymatic assays to combine precision and sensitivity. In the catechol O-methyltransferase assay separate portions of each plasma sample are incubated with either S-[ 3 H]- or S-[ 14 C]-adenosyl-L-methionine. Standards of noradrenaline and adrenaline are added to the latter portions and are thus converted into standards of [ 14 C]metadrenalines. These are added to the 3 H-labelled portions after the incubation, where they function as tracers. The final recovery of 14 C radioactivity corrects for (a) the efficiency of methylation in the plasma sample concerned and (b) the recovery of metadrenalines during the extraction procedures. The 3 H/ 14 C ratio is constant in each assay for a given catecholamine concentration and is determined for samples to which standards of noradrenaline and adrenaline are added to the 3 H- (as well as the 14 C-) labelled portions before the initial incubation. The sensitivity of the assay is increased by using high specific radioactivity S-[ 3 H]adenosyl-L-methionine, and low backgrounds are maintained by catecholamine depletion in vivo in the rats used for enzyme preparation. Both catecholamines (1.5 pg/ml; 10 pmol/l) may be detected; the coefficients of variation are 3.0 and 3.2% for noradrenaline and adrenaline respectively (intra-assay) and 4.6 and 5.0% (inter-assay). (author)

In vitro assessment of cytotoxicity and labeling efficiency of 99mTc-HMPAO with stromal vascular fraction of adipose tissue

International Nuclear Information System (INIS)

Verma, V.K.; Beevi, S.S.; Tabassum, A.; Kumaresan, K.; Kamaraju, R.S.; Arbab, A.S.; Chelluri, L.K.

2014-01-01

Introduction: Noninvasive radionuclide imaging of cells using technetium99m-hexamethylpropyleneamine oxime ( 99m Tc-HMPAO) is a potential diagnostic tool for several applications. Herein we aimed to evaluate the labeling efficiency and cellular toxicity of 99m Tc-HMPAO with Stromal Vascular Fraction (SVF) of adipose tissue to develop a process tool for theranostic purposes, in particular imaging cardiac stem cell therapy. Methods: Ten million cells of SVF were labeled with 99m Tc-HMPAO complex and excess radiolabel was cleared off through washing in PBS. The labeling efficiency of 99m Tc-HMPAO was detected in labeled cells and their subsequent supernatant wash using isotope dose calibrator and gamma camera. The cytotoxicity was assessed for the comparative reactive oxygen species (ROS) by H 2 DCFDDA, apoptotic events by annexin-V and TUNEL assay and mitochondrial potential by JC-1. Results: An encouraging labeling efficiency of 33% was observed with 99m Tc-HMPAO complex. The radionuclide labeling of SVF demonstrated significant safety profile as evaluated by apoptotic assays. Conclusion: 99m Tc-HMPAO labeling efficiency of 33% of total SV fraction would produce sufficient radioactive signals that would enable for in vivo tracking of cells by SPECT-CT. The radionuclide did not demonstrate any significant impact on the structural or functional organization of the labeled cells. Our study indicates that SVF can be safely labeled with 99m Tc-HMPAO without adverse cytotoxic events and for its potential role in imaging cardiac stem cell therapy

A 50 SNP-multiplex mass spectrometry assay for human identification

DEFF Research Database (Denmark)

Wächter, Andrea; Mengel-From, Jonas; Børsting, Claus

2008-01-01

We developed a 50 SNP-multiplex assay for detection on a MALDI-TOF MS platform based on the SNPs in the 52 SNP-multiplex assay recently developed by the SNPforID Consortium. After PCR amplification, the products were purified on Qiagen columns and used as templates in one single base extension (SBE...... primers were extended with biotin labelled ddNTPs and purified on avidin beads ensuring that only the extended SBE primers were isolated and spotted on the MALDI-TOF anchor target. Detection of the 50 extended primers from the SBE reaction was performed in a mass range between 3000 and 10,000 m/z...

DNA aptamer beacon assay for C-telopeptide and handheld fluorometer to monitor bone resorption.

Science.gov (United States)

Bruno, John Gordon; Carrillo, Maria P; Phillips, Taylor; Hanson, Douglas; Bohmann, Jonathan A

2011-09-01

A novel DNA aptamer beacon is described for quantification of a 26-amino acid C-telopeptide (CTx) of human type I bone collagen. One aptamer sequence and its reverse complement dominated the aptamer pool (31.6% of sequenced clones). Secondary structures of these aptamers were examined for potential binding pockets. Three-dimensional computer models which analyzed docking topologies and binding energies were in agreement with empirical fluorescence experiments used to select one candidate loop for beacon assay development. All loop structures from the aptamer finalists were end-labeled with TYE 665 and Iowa Black quencher for comparison of beacon fluorescence levels as a function of CTx concentration. The optimal beacon, designated CTx 2R-2h yielded a low ng/ml limit of detection using a commercially available handheld fluorometer. The CTx aptamer beacon bound full-length 26-amino acid CTx peptide, but not a shorter 8-amino acid segment of CTx peptide which is a common target for commercial CTx ELISA kits. The prototype assay was shown to detect CTx peptide from human urine after creatinine and urea were removed by size-exclusion chromatography to prevent nonspecific denaturing of the aptamer beacon. This work demonstrates the potential of aptamer beacons to be utilized for rapid and sensitive bone health monitoring in a handheld or point-of-care format.

Robotic Label Applicator: Design, Development and Visual Servoing Based Control

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Lin Chyi-Yeu

2016-01-01

Full Text Available Use of robotic arms and computer vision in manufacture, and assembly process are getting more interest as flexible customization is becoming priority over mass production as frontier industry practice. In this paper an innovative label applicator as end of arm tooling (EOAT capable of dispensing and applying label stickers of various dimensions to a product is designed, fabricated and tested. The system incorporates a label dispenserapplicator and had eye-in-hand camera system, attached to 6-dof robot arm can autonomously apply a label sticker to the target position on a randomly placed product. Employing multiple advantages from different knowledge basis, mechanism design and vision based automatic control, offers this system distinctive efficiency as well as flexibility to change in manufacturing and assembly process with time and cost saving.

[Inhibitory effect of baicalein on the proliferation and invasion of osteosarcoma cells and mechanism].

Science.gov (United States)

Tang, Zhibin; Li, Chun; Chen, Zhiwei

2015-03-01

To explore the effect of baicalein on the proliferation and invasion of osteosarcoma cells and its related mechanism. Osteosarcoma MG-63 cells that were cultured in vitro were respectively treated with 20 μL culture medium (control group), dehydrated alcohol (0 μmol/L baicalein group), 100 and 200 μmol/L baicalein solution for 48 hours. Cell proliferation was analyzed by MTT assay. The cell invasion ability was detected using Transwell(TM) invasion assay. The expression of ezrin mRNA was examined by real-time quantitative PCR. The expressions of ezrin protein and p-ezrin protein were measured using Western blotting. Apoptosis index (AI) was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). The inhibitory rates of cell proliferation significantly increased in 100 and 200 μmol/L baicalein groups as compared with 0 μmol/L baicalein group. Moreover, that was higher in 200 μmol/L baicalein group than in 100 μmol/L baicalein group. In comparison with control and 0 μmol/L baicalein groups, the mean cell numbers of permeated membrane and levels of ezrin mRNA, ezrin protein and p-ezrin protein gradually decreased, but AI was gradually elevated with the increase of baicalein concentrations, whereas there was no significant difference in these indicators between 0 μmol/L baicalein group and control group. Baicalein can inhibit the proliferation and invasion of osteosarcoma MG-63 cells. The mechanism may be associated with the inhibited expression and activity of ezrin protein and the promoted tumor cell apoptosis.

Puerarin protects differentiated PC12 cells from H₂O₂-induced apoptosis through the PI3K/Akt signalling pathway.

Science.gov (United States)

Zhang, Qin; Huang, Wei-Dong; Lv, Xue-Ying; Yang, Yun-Mei

2012-05-01

Oxidative stress has been implicated as a major mechanism underlying the pathogenesis of neurodegenerative disorders. ROS (reactive oxygen species) can cause cell death via apoptosis. NGF (nerve growth factor) differentiated rat PC12 cells have been extensively used to study the differentiation and apoptosis of neurons. This study has investigated the protective effects of puerarin in H2O2-induced apoptosis of differentiated PC12 cells, and the possible molecular mechanisms involved. Differentiated PC12 cells were incubated with 700 μM H2O2 in the absence or presence of different doses of puerarin (4, 8 and 16 μM). Apoptosis was assessed by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay, TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) analysis and Annexin V-PI (propidium iodide) double staining flow cytometry. Protein levels of phospho-Akt and phospho-BAD (Bcl-2/Bcl-XL-antagonist, causing cell death) were assayed by Western blotting. After stimulation with H2O2 for 18 h, the viability of differentiated PC12 cells decreased significantly and a large number of cells underwent apoptosis. Differentiated PC12 cells were rescued from H2O2-induced apoptosis at different concentrations of puerarin in a dose-dependent manner. This was through increased production of phospho-Akt and phospho-BAD, an effect that could be reversed by wortmannin, an inhibitor of PI3K (phosphoinositide 3-kinase). The results suggest that puerarin may have neuroprotective effect through activation of the PI3K/Akt signalling pathway.

Synthesis of Novel C-2- or C-15-Labeled BODIPY—Estrone Conjugates

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Ildikó Bacsa

2018-04-01

Full Text Available Novel BODIPY–estrone conjugates were synthesized via Cu(I-catalyzed azide–alkyne cycloaddition (CuAAC. Estrone-alkynes or an estrone-azide as starting compounds were synthesized via Michael addition or Sonogashira reaction as key steps. Fluorescent dyes based on BODIPY-core were provided by azide or alkyne functional groups. Fluorescent labeling of estrone was efficiently achieved at the C-2 or C-15 position. The newly-elaborated coupling procedures might have a broad applicability in the synthesis of fluorescent-labeled estrone conjugates suitable for biological assays.

Kinetic assays for determining in vitro APS reductase activity in plants without the use of radioactive substances.

Science.gov (United States)

Brychkova, Galina; Yarmolinsky, Dmitry; Sagi, Moshe

2012-09-01

Adenosine 5'-phosphosulfate (APS) reductase (APR; EC 1.8.4.9) catalyzes the two-electron reduction of APS to sulfite and AMP, a key step in the sulfate assimilation pathway in higher plants. In spite of the importance of this enzyme, methods currently available for detection of APR activity rely on radioactive labeling and can only be performed in a very few specially equipped laboratories. Here we present two novel kinetic assays for detecting in vitro APR activity that do not require radioactive labeling. In the first assay, APS is used as substrate and reduced glutathione (GSH) as electron donor, while in the second assay APS is replaced by an APS-regenerating system in which ATP sulfurylase catalyzes APS in the reaction medium, which employs sulfate and ATP as substrates. Both kinetic assays rely on fuchsin colorimetric detection of sulfite, the final product of APR activity. Incubation of the desalted protein extract, prior to assay initiation, with tungstate that inhibits the oxidation of sulfite by sulfite oxidase activity, resulted in enhancement of the actual APR activity. The reliability of the two methods was confirmed by assaying leaf extract from Arabidopsis wild-type and APR mutants with impaired or overexpressed APR2 protein, the former lacking APR activity and the latter exhibiting much higher activity than the wild type. The assays were further tested on tomato leaves, which revealed a higher APR activity than Arabidopsis. The proposed APR assays are highly specific, technically simple and readily performed in any laboratory.

LDLCHOLESTEROLEXAMINATION (LDL-C USINGHOMOGENEOUS ASSAY

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Made DwiAmbara Putra

2013-07-01

Full Text Available Homogeneous method describe as a method that does not require separation of free and bound label. This method has the ability tofully automate the determination of LDL-C directly small sample volume sand short examination time. In addition this method use automated pipette and control of time and temperature more accurate. There are 5 methods i.e. Solubilization homogeneous LDL-C assay (SOL from KyowaMedex, Surfactant LDL-C assay (SUR from Daiichi Pure Chemicals, Protecting LDL-assay reagent (PRO from Wako Chemicals, LDL-C assaycatalase (CAT Denka Seiken and Calixarene of LDL-C assay (CAL from International Reagents Corporation. All method is to use a variety of detergents and other chemicals that cause blocking or dissolution of specific lipoprotein classes to achieve specificity for LDL. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

Improvement of a real-time RT-PCR assay for the detection of enterovirus RNA

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Bruynseels Peggy

2009-07-01

Full Text Available Abstract We describe an improvement of an earlier reported real-time RT-PCR assay for the detection of enterovirus RNA, based on the 5' exonuclease digestion of a dual-labeled fluorogenic probe by Taq DNA polymerase. A different extraction method, real-time RT-PCR instrument and primer set were evaluated. Our data show that the optimized assay yields a higher sensitivity and reproducibility and resulted in a significant reduced hands-on time per sample.

Measurement of biologically active interleukin-1 by a soluble receptor binding assay

International Nuclear Information System (INIS)

Riske, F.; Chizzonite, R.; Nunes, P.; Stern, A.S.

1990-01-01

A soluble receptor binding assay has been developed for measuring human interleukin-1 alpha (IL-1 alpha), human IL-1 beta, and mouse IL-1 alpha. The assay is based on a competition between unlabeled IL-1 and 125I-labeled mouse recombinant IL-1 alpha for binding to soluble IL-1 receptor prepared from mouse EL-4 cells. The assay measures only biologically active IL-1 folded in its native conformation. The ratio of human IL-1 alpha to human IL-1 beta can be measured in the same sample by a pretreatment step which removes human IL-1 beta from samples prior to assay. This technique has been used to monitor the purification of recombinant IL-1, and may be utilized to specifically and accurately measure bioactive IL-1 in human serum and cell culture supernatants

Sensitive and rapid immunoassay for parathyroid hormone using magnetic particle labels and magnetic actuation.

Science.gov (United States)

Dittmer, W U; de Kievit, P; Prins, M W J; Vissers, J L M; Mersch, M E C; Martens, M F W C

2008-09-30

A rapid method for the sensitive detection of proteins using actuated magnetic particle labels, which are measured with a giant magneto-resistive (GMR) biosensor, is described. The technique involves a 1-step sandwich immunoassay with no fluid replacement steps. The various assay binding reactions as well as the bound/free separation are entirely controlled by magnetic forces induced by electromagnets above and below the sensor chip. During the assay, particles conjugated with tracer antibodies are actuated through the sample for target capture, and rapidly brought to the sensor surface where they bind to immobilized capture antibodies. Weakly or unbound labels are removed with a magnetic force oriented away from the GMR sensor surface. For the measurement of parathyroid hormone (PTH), a detection limit in the 10 pM range is obtained with a total assay time of 15 min when 300 nm particles are used. The same sensitivity can be achieved in 5 min when 500 nm particles are used. If 500 nm particles are employed in a 15-minute assay, then 0.8 pM of PTH is detectable. The low sample volume, high analytical performance and high speed of the test coupled with the compact GMR biosensor make the system especially suitable for sensitive testing outside of laboratory environments.

DNA gyrase with a single catalytic tyrosine can catalyze DNA supercoiling by a nicking-closing mechanism

Science.gov (United States)

Gubaev, Airat; Weidlich, Daniela; Klostermeier, Dagmar

2016-01-01

The topological state of DNA is important for replication, recombination and transcription, and is regulated in vivo by DNA topoisomerases. Gyrase introduces negative supercoils into DNA at the expense of ATP hydrolysis. It is the accepted view that gyrase achieves supercoiling by a strand passage mechanism, in which double-stranded DNA is cleaved, and a second double-stranded segment is passed through the gap, converting a positive DNA node into a negative node. We show here that gyrase with only one catalytic tyrosine that cleaves a single strand of its DNA substrate can catalyze DNA supercoiling without strand passage. We propose an alternative mechanism for DNA supercoiling via nicking and closing of DNA that involves trapping, segregation and relaxation of two positive supercoils. In contrast to DNA supercoiling, ATP-dependent relaxation and decatenation of DNA by gyrase lacking the C-terminal domains require both tyrosines and strand passage. Our results point towards mechanistic plasticity of gyrase and might pave the way for finding novel and specific mechanism-based gyrase inhibitors. PMID:27557712

Rapid colorimetric assay for gentamicin injection.

Science.gov (United States)

Tarbutton, P

1987-01-01

A rapid colorimetric method for determining gentamicin concentration in commercial preparations of gentamicin sulfate injection was developed. Methods currently available for measuring gentamicin concentration via its colored complex with cupric ions in alkaline solution were modified to reduce the time required for a single analysis. The alkaline copper tartrate (ACT) reagent solution was prepared such that each milliliter contained 100 mumol cupric sulfate, 210 mumol potassium sodium tartrate, and 1.25 mmol sodium hydroxide. The assay involves mixing 0.3 mL gentamicin sulfate injection 40 mg/mL (of gentamicin), 1.0 mL ACT reagent, and 0.7 mL water; the absorbance of the resulting solution at 560 nm was used to calculate the gentamicin concentration in the sample. For injections containing 10 mg/mL of gentamicin, the amount of the injection was increased to 0.5 mL and water decreased to 0.5 mL. The concentration of gentamicin in samples representing 11 lots of gentamicin sulfate injection 40 mg/mL and 8 lots of gentamicin sulfate injection 10 mg/mL was determined. The specificity, reproducibility, and accuracy of the assay were assessed. The colored complex was stable for at least two hours. Gentamicin concentration ranged from 93.7 to 108% and from 95 to 109% of the stated label value of the 40 mg/mL and the 10 mg/mL injections, respectively. No components of the preservative system present in the injections interfered with the assay. Since other aminoglycosides produced a colored complex, the assay is not specific for gentamicin. The assay was accurate and reproducible over the range of 4-20 mg of gentamicin. This rapid and accurate assay can be easily applied in the hospital pharmacy setting.

Magneto-optical labeling of fetal neural stem cells for in vivo MRI tracking.

Science.gov (United States)

Flexman, J A; Minoshima, S; Kim, Y; Cross, D J

2006-01-01

Neural stem cell therapy for neurological pathologies, such as Alzheimer's and Parkinson's disease, may delay the onset of symptoms, replace damaged neurons and/or support the survival of endogenous cells. Magnetic resonance imaging (MRI) can be used to track magnetically labeled cells in vivo to observe migration. Prior to transplantation, labeled cells must be characterized to show that they retain their intrinsic properties, such as cell proliferation into neurospheres in a supplemented environment. In vivo images must also be correlated to sensitive, histological markers. In this study, we show that fetus-derived neural stem cells can be co-labeled with superparamagnetic iron oxide and PKH26, a fluorescent dye. Labeled cells retain the ability to proliferate into neurospheres in culture, but labeling prevents neurospheres from merging in a non-adherent culture environment. After labeled NSCs were transplantation into the rat brain, their location and subsequent migration along the corpus callosum was detected using MRI. This study demonstrates an imaging paradigm with which to develop an in vivo assay for quantitatively evaluating fetal neural stem cell migration.

[Influence of dendritic cell infiltration on prognosis and biologic characteristics of progressing gastric cancer].

Science.gov (United States)

Huang, Hai-li; Wu, Ben-yan; You, Wei-di; Shen, Ming-shi; Wang, Wen-ju

2003-09-01

To study the relation between dendritic cell (DC) infiltration and clinicopathologic parameters, biologic characteristics and prognosis of progressing gastric cancer. The development of apoptotic cell death (apoptotic index, AI) in 61 progressing gastric carcinoma tissues was analyzed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling (TUNEL) method. The PCNA labeling index (PCNA-LI), density of dendritic cells in the tumor were detected by immunohistochemical method by the LSAB kit using antibody against S-100 protein and PC-10. DC infiltration was negatively correlated with lymph node metastasis, clinical stage and PCNA-LI, but positively with AI. The DCs in gastric cancer groups with and without lymph node metastasis were (5.63 +/- 4.37)/HPF and (8.51 +/- 5.57)/HPF with difference significant (P stage lesions were (11.23 +/- 6.05)/HPF, (6.28 +/- 4.37)/HPF and (5.53 +/- 5.19)/HPF also with differences significant (P gastric carcinoma.

Bcl-2, Bax, and c-Fos expression correlates to RPE cell apoptosis induced by UV-light and daunorubicin

DEFF Research Database (Denmark)

Liang, Y G; Jorgensen, A G; Kaestel, C G

2000-01-01

PURPOSE. The aim of this study was to determine the role of Bcl-2, Bcl-X L, Bax, and c-Fos in regulation of apoptosis, induced by ultraviolet-light A (UV-A) and daunorubicin (DNR), in retinal pigment epithelium (RPE) cells grown on bovine extracellular matrix (ECM)-coated or uncoated plastic dishes....... METHODS. Apoptosis in confluent RPE cells cultured on ECM-coated or uncoated dishes was induced by UV-A or DNR. Apoptosis was detected by 7-amino-actinomycin D labeling followed by flow cytometry and by terminal deoxy-transferase mediated X-dUTP nick end labeling (TUNEL). Cellular expression of Bcl-2, Bcl......-X L, Bax, and c-Fos was determined by the use of antibodies and flow cytometry, Western blot analysis, and immunocytochemical staining. RESULTS. Both UV-A and DNR induce apoptosis in human RPE cells in vitro. Human fetal RPE cells grown on ECM-coated dishes were significantly more resistant to UV...

Learning How to Simplify From Explicit Labeling of Complex-Simplified Text Pairs

DEFF Research Database (Denmark)

Alva-Manchego, Fernando; Bingel, Joachim; Paetzold, Gustavo H.

2017-01-01

that generalization becomes difficult. End-to-end models also make it hard to interpret what is actually learned from data. We propose a method that decomposes the task of TS into its sub-problems. We devise a way to automatically identify operations in a parallel corpus and introduce a sequence-labeling approach...

In vitro assessment of Tc-99m labeled bovine thrombin and streptokinase-activated human plasmin: concise communication

International Nuclear Information System (INIS)

Wong, D.W.; Tanaka, T.; Mishkin, F.; Lee, T.

1979-01-01

Bovine thrombin and streptokinase-activated human plasmin have been labeled with Tc-99m using stannous reduction of pertechnetate under physiological conditions (pH 7.4). The binding efficiency of radiotechnetium to these enzymes is greater than 94%, with less than 5% of reduced but unbound Tc-99m (Sn) complex as assayed by ascending paper radiochromatography using ITLC silica gel plate. Free or unbound pertechnetate is less than 1%. In vitro enzymatic analyses of the Tc-99m-labeled enzymes demonstrate no evidence of protein denaturation or significant loss of enzymatic activity after labeling. Both labeled enzymes are biochemically active in vitro with their respective substrates

Application of a Homogenous Assay for the Detection of 2,4,6-Trinitrotoluene to Environmental Water Samples

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Ellen R. Goldman

2005-01-01

Full Text Available A homogeneous assay was used to detect 2,4,6-trinitrotoluene (TNT spiked into environmental water samples. This assay is based on changes in fluorescence emission intensity when TNT competitively displaces a fluorescently labeled, TNT analog bound to an anti-TNT antibody. The effectiveness of the assay was highly dependent on the source of the sample being tested. As no correlation between pH and assay performance was observed, ionic strength was assumed to be the reason for variation in assay results. Addition of 10x phosphate-buffered saline to samples to increase their ionic strength to that of our standard laboratory buffer (about 0.17 M significantly improved the range over which the assay functioned in several river water samples.

An improved method of 18F peptide labeling: hydrazone formation with HYNIC-conjugated c(RGDyK)

International Nuclear Information System (INIS)

Lee, Yun-Sang; Jeong, Jae Min; Kim, Hyung Woo; Chang, Young Soo; Kim, Young Joo; Hong, Mee Kyung; Rai, Ganesha B.; Chi, Dae Yoon; Kang, Won Jun; Kang, Joo Hyun; Lee, Dong Soo; Chung, June-Key; Lee, Myung Chul; Suh, Young-Ger

2006-01-01

Radiolabeled α v β 3 -integrin antagonists are increasingly investigated as a means of imaging angiogenesis. Several methods of labeling α v β 3 -integrin binding peptide with 18 F have been reported recently. In the present study, we devised a straightforward means for labeling Arg-Gly-Asp (RGD) peptide with 18 F via hydrazone formation between c(RGDyK)-hydrazinonicotinic acid (HYNIC) (3) and 4-[ 18 F]-fluorobenzaldehyde ([ 18 F]4). The resulting reaction mixture was purified by HPLC to give 4'-[ 18 F]-fluorobenzylidenehydrazone-6-nicotinamide-c(RGDyK) ([ 18 F]5). The conjugation efficiency of 3 and 4 to form [ 18 F]5 was 95.2%, and the radiochemical purity of [ 18 F]5 after purification was >99%. The specific activity of [ 18 F]5 estimated by radio-HPLC was 20.5 GBq/μmol (end of synthesis). Competitive binding assay of c(RGDyK) (1) and 5 was performed using [ 125 I]iodo-c(RGDyK) as a radioligand, and K i values were found to be 2.8 and 21.7 nM, respectively. For the biodistribution study, the angiogenic mouse model was established by inducing unilateral ischemia on the left hindlimbs of ICR mice after femoral artery ablation. Seven days after inducing ischemia, [ 18 F]5 was administered to the mice through the tail vein. Ischemic muscle uptake of [ 18 F]5 was significantly higher than that of normal muscle (P 18 F]5. Here, we successfully labeled RGD peptide with 18 F via hydrazone formation between 3 and 4, resulting to [ 18 F]5. [ 18 F]5 was found to have high affinity for α v β 3 -integrin and to accumulate specifically in ischemic hindlimb muscle of mice. We suggest that 18 F labeling via formation of hydrazone between HYNIC peptide and [ 18 F]4 is a useful method for labeling c(RGDyK), which can be applied for imaging angiogenesis

Experiments for quick and accurate thorium assay by means of potentiometric end point determination

International Nuclear Information System (INIS)

Mainka, E.; Coerdt, W.

1978-10-01

Two methods are described which allow quick thorium assay easily to be automated. In the potentiometric titration with NaF the ion sensitive fluoride electrode is used as the indicator. The analysis can be performed for pH values 3 to 4. Th(OH) 4 precipitation must be avoided although the acidity of the solution must not be too high since otherwise erroneous measurements will be obtained. In the complexometric thorium assay EDTA is used for titration and the indicator is the copper sensitive electrode. This method offers the advantage that the analysis can be performed in the presence of large amounts of uranium, which is excluded under the NaF method. (orig.) [de

Competitive horseradish peroxidase-linked aptamer assay for sensitive detection of Aflatoxin B1.

Science.gov (United States)

Sun, Linlin; Zhao, Qiang

2018-03-01

Aflatoxin B1 (AFB1) is one of highly toxic mycotoxins and a known human carcinogen. The frequent contamination of AFB1 in food products and large health risk of AFB1 have raised global concerns. Sensitive detection of AFB1 is of vital importance and highly demanded. Herein, we reported a competitive horseradish peroxidase (HRP)-linked aptamer assay for AFB1, combining the advantages of aptamer for affinity binding and enzyme label for signal amplification. In this assay, free AFB1 in solution competed with a covalent conjugate of bovine serum albumin-AFB1 (BSA-AFB1) coated on the wells of microplate in binding to the HRP-labeled aptamer probe. HRP attached on BSA-AFB1 in the wells catalyzed the conversion of substrates into products, allowing the final detection of AFB1 through measurement of the generated products. When TMB (3,3',5,5'-tetramethylbenzidine dihydrochloride) was used as substrate, absorbance analysis of the product of enzyme reaction enabled the detection of AFB1 at 0.2nM. We further lowered the detection limit of AFB1 to 0.01nM through chemiluminescence analysis by using chemiluminescence substrate of HRP. This assay enabled the detection of AFB1 in complex sample matrix, such as diluted white wine and maize flour. This assay provides a simple, sensitive and rapid method for AFB1 determination. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of umbilical cord mesenchymal stem cells labeling with superparamagnetic iron oxide nanoparticles coated with dextran and complexed with Poly-L-Lysine

International Nuclear Information System (INIS)

Sibov, Tatiana Tais; Mamani, Javier Bustamante; Pavon, Lorena Favaro; Cardenas, Walter Humberto; Gamarra, Lionel Fernel; Miyaki, Liza Aya Mabuchi; Marti, Luciana Cavalheiro; Sardinha, Luiz Roberto; Oliveira, Daniela Mara de

2012-01-01

Objective: The objective of this study was to evaluate the effect of the labeling of umbilical cord vein derived mesenchymal stem cells with superparamagnetic iron oxide nanoparticles coated with dextran and complexed to a non-viral transfector agent transfector poly-L-lysine. Methods: The labeling of mesenchymal stem cells was performed using the superparamagnetic iron oxide nanoparticles/dextran complexed and not complexed to poly-L-lysine. Superparamagnetic iron oxide nanoparticles/dextran was incubated with poly-L-lysine in an ultrasonic sonicator at 37 deg C for 10 minutes for complex formation superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine by electrostatic interaction. Then, the mesenchymal stem cells were incubated overnight with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran. After the incubation period the mesenchymal stem cells were evaluated by internalization of the complex superparamagnetic iron oxide nanoparticles/dextran/polyL-lysine and superparamagnetic iron oxide nanoparticles/dextran by Prussian Blue stain. Cellular viability of labeled mesenchymal stem cells was evaluated by cellular proliferation assay using 5,6-carboxyfluorescein-succinimidyl ester method and apoptosis detection by Annexin V- Propidium Iodide assay. Results: mesenchymal stem cells labeled with superparamagnetic iron oxide nanoparticles/ dextran without poly-L-lysine not internalized efficiently the superparamagnetic iron oxide nanoparticles due to its low presence detected within cells. Mesenchymal stem cells labeled with the complex superparamagnetic iron oxide nanoparticles/dextran/polyL-lysine efficiently internalized the superparamagnetic iron oxide nanoparticles due to greater presence in the cells interior. The viability and apoptosis assays demonstrated that the mesenchymal stem cells labeled and not labeled respectively with the superparamagnetic iron oxide

Computer-determined assay time based on preset precision

International Nuclear Information System (INIS)

Foster, L.A.; Hagan, R.; Martin, E.R.; Wachter, J.R.; Bonner, C.A.; Malcom, J.E.

1994-01-01

Most current assay systems for special nuclear materials (SNM) operate on the principle of a fixed assay time which provides acceptable measurement precision without sacrificing the required throughput of the instrument. Waste items to be assayed for SNM content can contain a wide range of nuclear material. Counting all items for the same preset assay time results in a wide range of measurement precision and wastes time at the upper end of the calibration range. A short time sample taken at the beginning of the assay could optimize the analysis time on the basis of the required measurement precision. To illustrate the technique of automatically determining the assay time, measurements were made with a segmented gamma scanner at the Plutonium Facility of Los Alamos National Laboratory with the assay time for each segment determined by counting statistics in that segment. Segments with very little SNM were quickly determined to be below the lower limit of the measurement range and the measurement was stopped. Segments with significant SNM were optimally assays to the preset precision. With this method the total assay time for each item is determined by the desired preset precision. This report describes the precision-based algorithm and presents the results of measurements made to test its validity

Treatment of Arsenite Intoxication-Induced Peripheral Vasculopathy with Mesenchymal Stem Cells

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Yi-Hung Chiang

2018-03-01

Full Text Available Arsenite (As, a notorious toxic metal, is ubiquitously distributed in the earth and poses a serious threat to human health. Histopathological lesions of As intoxication are known as thromboangiitis obliterans, which are resistant to current treatment and often lead to lower limb amputation. In this study, we attempt to find that treatment with mesenchymal stem cells (MSCs may be effective for As-induced vasculopathy. We first conducted an in vitro study with a co-culture system containing human MSCs and human umbilical vein endothelial cells (HUVECs and treated individual and co-cultured cells with various concentrations of arsenite. We also designed an in vivo study in which Sprague Dawley (SD rats received periodic intraperitoneal (IP injections of 16 ppm arsenite for 12 weeks. MSCs were harvested from BALB/c mice that were transplanted via tail vein injection. We found that there was significantly higher cellular viability in human mesenchymal stem cells (hMSCs than in HUVECs under concentrations of arsenite between 15 and 25 μM. The Annexin V apoptosis assay further confirmed this finding. Cytokine array assay for As-conditioned media revealed an elevated vascular endothelial growth factor (VEGF level secreted by MSCs, which is crucial for HUVEC survival and was evaluated by an siRNA VEGF knockdown test. In the in vivo study, we demonstrated early apoptotic changes in the anterior tibial vessels of As-injected SD rats with a Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay, but these apoptotic changes were less frequently observed upon MSCs transplantation, indicating that the cytoprotective effect of MSCs successfully protected against As-induced peripheral vasculopathy. The feasibility of MSCs to treat and /or prevent the progression of As-induced vasculopathy is justified. Further clinical studies are required to demonstrate the therapeutic efficacy of MSCs in patients suffering from As intoxication with

[Effect of NOR1 gene knockdown on the biological behavior of HeLa cells].

Science.gov (United States)

Tan, Yixin; Li, Wenjuan; Yi, Mei; Wang, Wei; Zheng, Pan; Zhang, Haijing; Xiang, Bo; Li, Guiyuan

2014-08-01

To explore the effect of the oxidored nitro domain containing protein 1 (NOR1) gene knockdown on the biological behavior of HeLa cells in cervical carcinoma. The recombinant plasmids pSUPER-shNOR1-1, pSUPER-shNOR1-2 and pSUPERscramble, which targeted to NOR1 gene, were constructed by pSUPER.neo+GFP vector, transfected into HeLa cells respectively using Lipofectamine 2000 reagent, and followed by G418 selection. The expression level of NOR1 mRNA and protein were determined by RT-PCR and Western blotting, respectively. Methyl thiazolyl tetrazolium (MTT) assay was performed to determine the growth curve of cell viability. The stable transfectants were treated with H₂O₂ and cell apoptosis was determined by Hoechst 33258 staining and terminal deoxynucleotidyl transferasemediated dUTP nick end labeling (TUNEL) assay. The expression levels of Bcl-2, cleaved caspase 9 and poly ADP-ribose polymerase (PARP) were measured by Western blot. NOR1- knockdown HeLa cells were successfully constructed by transfection of pSUPER-shNOR1-1 or pSUPER-shNOR1-2 plasmids into HeLa cells. MTT assay showed that the silence of endogenous NOR1 in HeLa cells could lead to the increase in cell viability and proliferation, and the inhibition of H₂O₂-induced apoptosis compared with the negative control. Western blot showed that the expression level of active caspase 9 and cleaved PARP was inhibited in NOR1-knockdown cells when they were treated with H₂O₂ while the expression level of Bcl-2 protein increased. Silence of endogenous NOR1 facilitates the cell viability and growth of HeLa cells, and attenuates HeLa cells apoptosis induced by H₂O₂, which might be mediated by up-regulation of Bcl-2 level and down-regulation of the cleaved caspase 9 cascade.

Anti-oxidative and anti-inflammatory effects of cinnamaldehyde on protecting high glucose-induced damage in cultured dorsal root ganglion neurons of rats.

Science.gov (United States)

Yang, Dan; Liang, Xiao-Chun; Shi, Yue; Sun, Qing; Liu, Di; Liu, Wei; Zhang, Hong

2016-01-01

To examine the mechanism underlying the beneficial role of cinnamaldehyde on oxidative damage and apoptosis in high glucose (HG)-induced dorsal root ganglion (DRG) neurons in vitro. HG-treated DRG neurons were developed as an in vitro model of diabetic neuropathy. The neurons were randomly divided into five groups: the control group, the HG group and the HG groups treated with 25, 50 and 100 nmol/L cinnamaldehyde, respectively. Cell viability was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and apoptosis rate was evaluated by the in situ TdT-mediated dUTP nick end labeling (TUNEL) assay. The intracellular level of reactive oxygen species (ROS) was measured with flow cytometry. Expression of nuclear factor-kappa B (NF-κB), inhibitor of κB (IκB), phosphorylated IκB (p-IκB), tumor necrosis factor (TNF)-α, interleukin-6 (IL-6) and caspase-3 were determined by western blotting and real-time quantitative reverse transcription polymerase chain reaction (RT-PCR). Expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1) were also measured by western blotting. Cinnamaldehyde reduced HG-induced loss of viability, apoptosis and intracellular generation of ROS in the DRG neurons via inhibiting NF-κB activity. The western blot assay results showed that the HG-induced elevated expressions of NF-κB, IκB and p-IκB were remarkably reduced by cinnamaldehyde treatment in a dose-dependent manner (P neurons, but also lowered the elevated IL-6, TNF-α, cyclo-oxygenase and inducible nitric oxide synthase levels, indicating a reduction in inflammatory damage. Cinnamaldehyde protected DRG neurons from the deleterious effects of HG through inactivation of NF-κB pathway but not through activation of Nrf2/HO-1. And thus cinnamaldehyde may have potential application as a treatment for DPN.

Indirect solid-phase immunosorbent assay for detection of arenavirus antigens and antibodies

Energy Technology Data Exchange (ETDEWEB)

Ivanov, A P; Rezapkin, G V; Dzagurova, T K; Tkachenko, E A [Institute of Poliomyelitis anU Viral Encephalities of the U.S.S.R. Academy of Medical Sciences, Moscow

1984-05-01

Indirect enzyme-linked immunosorbent assay (ELISA) and solid phase radioimmunoassay (SPRIA) using either enti-human or anti-mouse IgG labelled with horseradish peroxidase and /sup 125/I, respectively, were developed for the detection of Junin, Machupo, Tacaribe, Amapari, Tamiami, Lassa and LCM arenaviruses. Both methods allow high sensitivity detection of arenavirus antigens and antibodies.

Making food labels social: The impact of colour of nutritional labels and injunctive norms on perceptions and choice of snack foods.

Science.gov (United States)

Vasiljevic, Milica; Pechey, Rachel; Marteau, Theresa M

2015-08-01

Recent studies report that using green labels to denote healthier foods, and red to denote less healthy foods increases consumption of green- and decreases consumption of red-labelled foods. Other symbols (e.g. emoticons conveying normative approval and disapproval) could also be used to signal the healthiness and/or acceptability of consuming such products. The present study tested the combined effects of using emoticons and colours on labels amongst a nationally representative sample of the UK population (n = 955). In a 3 (emoticon expression: smiling vs. frowning vs. no emoticon) × 3 (colour label: green vs. red vs. white) ×2 (food option: chocolate bar vs. cereal bar) between-subjects experiment, participants rated the level of desirability, healthiness, tastiness, and calorific content of a snack bar they had been randomised to view. At the end they were further randomised to view one of nine possible combinations of colour and emoticon labels and asked to choose between a chocolate and a cereal bar. Regardless of label, participants rated the chocolate as tastier and more desirable when compared to the cereal bar, and the cereal bar as healthier than the chocolate bar. A series of interactions revealed that a frowning emoticon on a white background decreased perceptions of healthiness and tastiness of the cereal bar, but not the chocolate bar. In the explicit choice task selection was unaffected by label. Overall nutritional labels had limited effects on perceptions and no effects on choice of snack foods. Emoticon labels yielded stronger effects on perceptions of taste and healthiness of snacks than colour labels. Frowning emoticons may be more potent than smiling emoticons at influencing the perceived healthiness and tastiness of foods carrying health halos. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

DNA probe labeling with digoxigenin-dUTP and its application in gene diagnosis

International Nuclear Information System (INIS)

Liu Guoyang

1992-01-01

DNA probe labeling by the randomly primed incorporation of digoxigenin-dUTP is reported. The sensitivity of color reaction and hybridization were 32 fg and 200 fg, respectively, and both were specific for the target. Single-copy and multi-copy gene fragments among 2 μg human genomic DNA were detected by β IVS II, Fr 3-42 and 3'HVR labeled with digoxigenin-dUTP. The results were consistent with a radioactive control assay. This method has been successfully used in the gene diagnosis of adult polycystic kidney disease

Detection of irradiation induced modifications in foodstuff DNA using 32p post-labelling

International Nuclear Information System (INIS)

Hoey, B.M.; Swallow, A.J.; Margison, G.P.

1991-01-01

DNA post-labelling has been used successfully to detect damage to DNA caused by a range of damaging agents. The assay results in a fingerprint of changes induced in DNA which might, in principle, be useful as a test for the detection of the irradiation of foods. The authors present their DNA extraction and 32 p post-labelling methods from chicken or cooked prawn samples and their analysis method (High Performance liquid chromatography). It's hoped that these results could form the basis of a test to detect if foods have been irradiated

Measurement of immunoglobulin production by peripheral blood mononuclear cells in vitro using a solid-phase immunoradiometric assay

International Nuclear Information System (INIS)

Roffe, L.M.; Maini, R.N.; Cohen, M.L.; Meretey, K.

1981-01-01

A simple solid-phase immunoradiometric assay for IgG and IgM is described. Supernatants from lymphocyte cultures are incubated in microtitre plates which have been precoated with anti-IgG or anti-IgM. Subsequent binding of 125 I-labelled anti-immunoglobulin is measured and IgG and IgM in supernatants are estimated from the standard curve constructed for each assay. The assay is specific for human IgG and IgM, is able to detect nanogram amounts and offers advantages over other techniques for evaluating in vitro lymphocyte function. (Auth.)

Lesion-induced DNA weak structural changes detected by pulsed EPR spectroscopy combined with site-directed spin labelling.

Science.gov (United States)

Sicoli, Giuseppe; Mathis, Gérald; Aci-Sèche, Samia; Saint-Pierre, Christine; Boulard, Yves; Gasparutto, Didier; Gambarelli, Serge

2009-06-01

Double electron-electron resonance (DEER) was applied to determine nanometre spin-spin distances on DNA duplexes that contain selected structural alterations. The present approach to evaluate the structural features of DNA damages is thus related to the interspin distance changes, as well as to the flexibility of the overall structure deduced from the distance distribution. A set of site-directed nitroxide-labelled double-stranded DNA fragments containing defined lesions, namely an 8-oxoguanine, an abasic site or abasic site analogues, a nick, a gap and a bulge structure were prepared and then analysed by the DEER spectroscopic technique. New insights into the application of 4-pulse DEER sequence are also provided, in particular with respect to the spin probes' positions and the rigidity of selected systems. The lesion-induced conformational changes observed, which were supported by molecular dynamics studies, confirm the results obtained by other, more conventional, spectroscopic techniques. Thus, the experimental approaches described herein provide an efficient method for probing lesion-induced structural changes of nucleic acids.

End-to-End Airplane Detection Using Transfer Learning in Remote Sensing Images

Directory of Open Access Journals (Sweden)

Zhong Chen

2018-01-01

Full Text Available Airplane detection in remote sensing images remains a challenging problem due to the complexity of backgrounds. In recent years, with the development of deep learning, object detection has also obtained great breakthroughs. For object detection tasks in natural images, such as the PASCAL (Pattern Analysis, Statistical Modelling and Computational Learning VOC (Visual Object Classes Challenge, the major trend of current development is to use a large amount of labeled classification data to pre-train the deep neural network as a base network, and then use a small amount of annotated detection data to fine-tune the network for detection. In this paper, we use object detection technology based on deep learning for airplane detection in remote sensing images. In addition to using some characteristics of remote sensing images, some new data augmentation techniques have been proposed. We also use transfer learning and adopt a single deep convolutional neural network and limited training samples to implement end-to-end trainable airplane detection. Classification and positioning are no longer divided into multistage tasks; end-to-end detection attempts to combine them for optimization, which ensures an optimal solution for the final stage. In our experiment, we use remote sensing images of airports collected from Google Earth. The experimental results show that the proposed algorithm is highly accurate and meaningful for remote sensing object detection.

Biotin radioligand assay with an 125I-labeled biotin derivative, avidin, and avidin double-antibody reagents

International Nuclear Information System (INIS)

Livaniou, E.; Evangelatos, G.P.; Ithakissios, D.S.

1987-01-01

We describe a new radioligand assay for determining biotin in biological fluids by using a mixture of N-[beta-(4-OH-3-125I-phenyl)ethyl]- and N-[beta-(4-OH-3,5-di-125I-phenyl)ethyl]biotinamides as radiotracer, avidin as a binding protein, and an avidin double-antibody as a separation reagent. The radiotracer is synthesized by coupling (at pH 8.5, 20-22 degrees C, 90 min) N-hydroxysuccinimidobiotin to radioiodinated tyramine. The assay curve is linear and the assay itself is sensitive (less than 10 ng/L), reproducible (intra- and interassay CVs 4.1% and 7.0%, respectively), and allows the simultaneous handling of more than 100 samples in less than 4 h. Serum samples from apparently normal subjects contained 100-840 ng of biotin per liter (mean 340 ng/L). Pregnant women had low concentrations of biotin (100-300 ng/L) in their serum. Patients undergoing chronic hemodialysis treatment showed high concentrations (0.5-3.0 micrograms/L), which may be ascribable to the inability of avidin, which was used as the assay binding protein, to distinguish biotin from biotinyl derivatives with an intact ureido ring

Optimization and development of a high-performance liquid chromatography-based one-site immunometric assay with chemiluminescence detection

International Nuclear Information System (INIS)

Oates, Matthew R.; Clarke, William; Zimlich, Alden; Hage, David S.

2002-01-01

Various practical and theoretical considerations were examined in the creation and optimization of a high-performance liquid chromatography (HPLC)-based one-site immunometric assay. This method used an HPLC analyte analog column and post-column chemiluminescence detection. The specific analyte chosen as the model for this study was L-thyroxine (also known as T 4 ). In this technique, a sample containing thyroxine was first combined with an excess of anti-T 4 antibody Fab fragments that had earlier been conjugated with chemiluminescent acridinium ester labels. After incubation, the mixture was injected onto a column that contained immobilized T 4 . The amount of thyroxine in the original sample was then determined by measuring the labeled Fab fragments that appeared in the non-retained fraction, or the decrease in excess Fab fragments that were bound to and later eluted from the column. Items considered in creating this assay included the preparation of acridinium ester-labeled Fab fragments, the detection of these fragments with a post-column reactor, and the creation of a suitable immobilized analog column for capturing excess labeled Fab fragments. The final method could measure T 4 in standards at clinically-relevant concentrations and provided a response within 1.5 min of sample injection, following a 20-45 min incubation with the labeled Fab fragments. Possible applications of this method include its use in clinical chemistry and the screening of proteomic or combinatorial libraries

Development of a radioreceptor assay for human chorion gonadotropin: Application in normal and pathological pregnancies

International Nuclear Information System (INIS)

Koch, R.

1978-01-01

Rats testes were homogenised, and the binding capacity of several dilutions of these were tested with iodine 125 -labelled human choriongonadotropin. Investigations about binding over a period of 36 hrs. with 3 different temperatures, inhibition tests and cross reaction analyses for determining the specificity were carried out. 2 assay systems could be developed. The highly sensitive assay was applied at early pregnancy, at suspected disturbed or ectopic gravidity and allowed to measure the hCG-serum concentration above the physiological basal secretion of hLH. The less sensitive assay was used for measuring hCG in later stages of pregnancy, chorionepitheliomas and other hCG producing tumours. With the highly sensitive and specific assay, hCG was determinable 8 to 10 days post conceptionem. (orig.) [de

A comparative study of fat storage quantitation in nematode Caenorhabditis elegans using label and label-free methods.

Directory of Open Access Journals (Sweden)

Kelvin Yen

Full Text Available The nematode Caenorhabditis elegans has been employed as a model organism to study human obesity due to the conservation of the pathways that regulate energy metabolism. To assay for fat storage in C. elegans, a number of fat-soluble dyes have been employed including BODIPY, Nile Red, Oil Red O, and Sudan Black. However, dye-labeled assays produce results that often do not correlate with fat stores in C. elegans. An alternative label-free approach to analyze fat storage in C. elegans has recently been described with coherent anti-Stokes Raman scattering (CARS microscopy. Here, we compare the performance of CARS microscopy with standard dye-labeled techniques and biochemical quantification to analyze fat storage in wild type C. elegans and with genetic mutations in the insulin/IGF-1 signaling pathway including the genes daf-2 (insulin/IGF-1 receptor, rict-1 (rictor and sgk-1 (serum glucocorticoid kinase. CARS imaging provides a direct measure of fat storage with unprecedented details including total fat stores as well as the size, number, and lipid-chain unsaturation of individual lipid droplets. In addition, CARS/TPEF imaging reveals a neutral lipid species that resides in both the hypodermis and the intestinal cells and an autofluorescent organelle that resides exclusively in the intestinal cells. Importantly, coherent addition of the CARS fields from the C-H abundant neutral lipid permits selective CARS imaging of the fat store, and further coupling of spontaneous Raman analysis provides unprecedented details including lipid-chain unsaturation of individual lipid droplets. We observe that although daf-2, rict-1, and sgk-1 mutants affect insulin/IGF-1 signaling, they exhibit vastly different phenotypes in terms of neutral lipid and autofluorescent species. We find that CARS imaging gives quantification similar to standard biochemical triglyceride quantification. Further, we independently confirm that feeding worms with vital dyes does not lead

Fluorescence quenching of graphene oxide combined with the site-specific cleavage of restriction endonuclease for deoxyribonucleic acid demethylase activity assay

Energy Technology Data Exchange (ETDEWEB)

Ji, Lijuan; Qian, Yingdan; Wu, Ping; Zhang, Hui; Cai, Chenxin, E-mail: cxcai@njnu.edu.cn

2015-04-15

Highlights: • An approach for sensitive and selective DNA demethylase activity assay is reported. • This assay is based on the fluorescence quenching of GO and site-specific cleavage of endonuclease. • It can determine as low as 0.05 ng mL{sup −1} of MBD2 with a linear range of 0.2–300 ng mL{sup −1}. • It has an ability to recognize MBD2 from other possibly coexisting proteins and cancer cell extracts. • It can avoid false signals, requiring no bisulfite conversion, PCR amplification, radioisotope-labeling. - Abstract: We report on the development of a sensitive and selective deoxyribonucleic acid (DNA) demethylase (using MBD2 as an example) activity assay by coupling the fluorescence quenching of graphene oxide (GO) with the site-specific cleavage of HpaII endonuclease to improve the selectivity. This approach was developed by designing a single-stranded probe (P1) that carries a binding region to facilitate the interaction with GO, which induces fluorescence quenching of the labeled fluorophore (FAM, 6-carboxyfluorescein), and a sensing region, which contains a hemi-methylated site of 5′-CmCGG-3′, to specifically recognize the target (T1, a 32-mer DNA from the promoter region of p53 gene) and hybridize with it to form a P1/T1 duplex. After demethylation with MBD2, the duplex can be specifically cleaved using HpaII, which releases the labeled FAM from the GO surface and results in the recovery of fluorescence. However, this cleavage is blocked by the hemi-methylation of this site. Thus, the magnitude of the recovered fluorescence signal is related to the MBD2 activity, which establishes the basis of the DNA demethylase activity assay. This assay can determine as low as ∼(0.05 ± 0.01) ng mL{sup −1} (at a signal/noise of 3) of MBD2 with a linear range of 0.2–300 ng mL{sup −1} and recognize MBD2 from other possibly coexisting proteins and cancer cell extracts. The advantage of this assay is its ability to avoid false signals and no

A Comparison of Exogenous Labels for the Histological Identification of Transplanted Neural Stem Cells

Science.gov (United States)

Nicholls, Francesca J.; Liu, Jessie R.; Modo, Michel

2017-01-01

The interpretation of cell transplantation experiments is often dependent on the presence of an exogenous label for the identification of implanted cells. The exogenous labels Hoechst 33342, 5-bromo-2′-deoxyuridine (BrdU), PKH26, and Qtracker were compared for their labeling efficiency, cellular effects, and reliability to identify a human neural stem cell (hNSC) line implanted intracerebrally into the rat brain. Hoechst 33342 (2 mg/ml) exhibited a delayed cytotoxicity that killed all cells within 7 days. This label was hence not progressed to in vivo studies. PKH26 (5 μM), Qtracker (15 nM), and BrdU (0.2 μM) labeled 100% of the cell population at day 1, although BrdU labeling declined by day 7. BrdU and Qtracker exerted effects on proliferation and differentiation. PKH26 reduced viability and proliferation at day 1, but this normalized by day 7. In an in vitro coculture assay, all labels transferred to unlabeled cells. After transplantation, the reliability of exogenous labels was assessed against the gold standard of a human-specific nuclear antigen (HNA) antibody. BrdU, PKH26, and Qtracker resulted in a very small proportion (Exogenous labels can therefore be reliable to identify transplanted cells without exerting major cellular effects, but validation is required. The interpretation of cell transplantation experiments should be presented in the context of the label's limitations. PMID:27938486

In vitro assessment of cytotoxicity and labeling efficiency of {sup 99m}Tc-HMPAO with stromal vascular fraction of adipose tissue

Energy Technology Data Exchange (ETDEWEB)

Verma, V. K.; Beevi, S. S. [Department of Transplant Biology, Immunology and Stem Cell Lab, Global Hospitals, Hyderabad (India); Tabassum, A.; Kumaresan, K. [KK Nuclear Scans, Raj Bhavan Road, Somajiguda, Hyderabad (India); Kamaraju, R. S. [Department of Transplant Biology, Immunology and Stem Cell Lab, Global Hospitals, Hyderabad (India); Arbab, A. S. [Cancer Centre, GA Regents University, Augusta, GA (United States); Chelluri, L.K., E-mail: lkiran@globalhospitalsindia.com [Department of Transplant Biology, Immunology and Stem Cell Lab, Global Hospitals, Hyderabad (India)

2014-10-15

Introduction: Noninvasive radionuclide imaging of cells using technetium99m-hexamethylpropyleneamine oxime ({sup 99m}Tc-HMPAO) is a potential diagnostic tool for several applications. Herein we aimed to evaluate the labeling efficiency and cellular toxicity of {sup 99m}Tc-HMPAO with Stromal Vascular Fraction (SVF) of adipose tissue to develop a process tool for theranostic purposes, in particular imaging cardiac stem cell therapy. Methods: Ten million cells of SVF were labeled with {sup 99m}Tc-HMPAO complex and excess radiolabel was cleared off through washing in PBS. The labeling efficiency of {sup 99m}Tc-HMPAO was detected in labeled cells and their subsequent supernatant wash using isotope dose calibrator and gamma camera. The cytotoxicity was assessed for the comparative reactive oxygen species (ROS) by H{sub 2}DCFDDA, apoptotic events by annexin-V and TUNEL assay and mitochondrial potential by JC-1. Results: An encouraging labeling efficiency of 33% was observed with {sup 99m}Tc-HMPAO complex. The radionuclide labeling of SVF demonstrated significant safety profile as evaluated by apoptotic assays. Conclusion: {sup 99m}Tc-HMPAO labeling efficiency of 33% of total SV fraction would produce sufficient radioactive signals that would enable for in vivo tracking of cells by SPECT-CT. The radionuclide did not demonstrate any significant impact on the structural or functional organization of the labeled cells. Our study indicates that SVF can be safely labeled with {sup 99m}Tc-HMPAO without adverse cytotoxic events and for its potential role in imaging cardiac stem cell therapy.

Two-monoclonal-antibody sandwich-type assay for thyrotropin, with use of an avidin-biotin separation technique

International Nuclear Information System (INIS)

Odell, W.D.; Griffin, J.; Zahradnik, R.

1986-01-01

We have developed a sensitive, specific, noncompetitive, sandwich-type radioimmunoassay for human thyrotropin (hTSH), which can be performed in 30 min. The assay involves two monoclonal antibodies, selected for high affinity and specificity and also for reaction against antigenic sites on hTSH that are distal from each other. One of these antibodies is labeled with 125 I; the other is conjugated covalently to biotin. Polystyrene beads were also conjugated covalently to biotin. After conjugation, the beads were incubated with avidin. These beads represent a rapid, simple method for separating hTSH-bound antibody from free antibody. The biotin-antibody-hTSH- 125 I-labeled antibody complexes bind to the beads and hTSH concentration is directly related to counts per minute. This assay can detect hTSH at a concentration of 0.06 milli-unit/L in serum

A Highly Sensitive Telomerase Activity Assay that Eliminates False-Negative Results Caused by PCR Inhibitors

Directory of Open Access Journals (Sweden)

Hidenobu Yaku

2013-09-01

Full Text Available An assay for telomerase activity based on asymmetric polymerase chain reaction (A-PCR on magnetic beads (MBs and subsequent application of cycling probe technology (CPT is described. In this assay, the telomerase reaction products are immobilized on MBs, which are then washed to remove PCR inhibitors that are commonly found in clinical samples. The guanine-rich sequences (5'-(TTAGGGn-3' of the telomerase reaction products are then preferentially amplified by A-PCR, and the amplified products are subsequently detected via CPT, where a probe RNA with a fluorophore at the 5' end and a quencher at the 3' end is hydrolyzed by RNase H in the presence of the target DNA. The catalyst-mediated cleavage of the probe RNA enhances fluorescence from the 5' end of the probe. The assay allowed us to successfully detect HeLa cells selectively over normal human dermal fibroblast (NHDF cells. Importantly, this selectivity produced identical results with regard to detection of HeLa cells in the absence and presence of excess NHDF cells; therefore, this assay can be used for practical clinical applications. The lower limit of detection for HeLa cells was 50 cells, which is lower than that achieved with a conventional telomeric repeat amplification protocol assay. Our assay also eliminated false-negative results caused by PCR inhibitors. Furthermore, we show that this assay is appropriate for screening among G-quadruplex ligands to find those that inhibit telomerase activity.

Blood cells kinetics by stable tracers assayed by XRF-analysis and by radioactive tracers

International Nuclear Information System (INIS)

Cesareo, R.; Del Principe, D.; Tallarida, B.

1980-01-01

Stable rubidium, as an analogue of potassium, has been employed to label human and rabbit red cells and platelets. The concentration of rubidium bound to the cells, which are deposited on filter paper disks, is assayed by a simple version of the X-ray fluorescence equipment, characterized by a 1 mCi Cd-109 radioisotopic source, a xenon-filled proportional detector and a single-channel-analyzer. Survival curves of platelets and of red-cells labelled with stable Rb were determined by measuring the Rb concentration in the labelled cells, withdrawn at different times. The fluorescent counts are linearly proportional to the mass of rubidium per unit area of the filter. The sensitivity of the XRF technique is about 0.05 μg/cm 2 in a measuring time of 500 s. The mean quantity of Rb incorporated by the platelets is of about 5-10 μg for human platelets labelled ''in vitro'', of about 30-50 μg for rabbit platelets labelled in vivo and of about 0.5 mg for rabbit red cell labelled in vivo. The following half-time values were deduced: Tsub(1/2) = 35-45 h for human platelets labelled in ''in vitro''. Tsub(1/2) = 22 +- 3 h for rabbit platelets labelled ''in vivo''. Tsub(1/2) = 310 +- 15 h for rabbit red cells labelled ''in vivo''. The next step of our studies is to label ''in vivo'' human red cells and human platelets. (author)

[{sup 131}I]FIAU labeling of genetically transduced, tumor-reactive lymphocytes: cell-level dosimetry and dose-dependent toxicity

Energy Technology Data Exchange (ETDEWEB)

Zanzonico, Pat [Memorial Sloan-Kettering Cancer Center, Department of Medical Physics, New York, NY (United States); Koehne, Guenther; Doubrovina, Ekaterina; O' Reilly, Richard J. [Memorial Sloan-Kettering Cancer Center, Allogeneic Transplantation Service, New York, NY (United States); Memorial Sloan-Kettering Cancer Center, Immunology Program, New York, NY (United States); Gallardo, Humilidad F. [Memorial Sloan-Kettering Cancer Center, Gene Transfer and Somatic Cell Engineering Facility, New York, NY (United States); Doubrovin, Mikhail; Blasberg, Ronald G. [Memorial Sloan-Kettering Cancer Center, Department of Radiology, New York, NY (United States); Memorial Sloan-Kettering Cancer Center, Department of Neurology, New York, NY (United States); Finn, Ronald [Memorial Sloan-Kettering Cancer Center, Radiochemistry and Cyclotron Core Facility, New York, NY (United States); Riviere, Isabelle; Sadelain, Michel [Memorial Sloan-Kettering Cancer Center, Immunology Program, New York, NY (United States); Memorial Sloan-Kettering Cancer Center, Gene Transfer and Somatic Cell Engineering Facility, New York, NY (United States); Larson, Steven M. [Memorial Sloan-Kettering Cancer Center, Department of Radiology, New York, NY (United States)

2006-09-15

Donor T cells have been shown to be reactive against and effective in adoptive immunotherapy of Epstein-Barr virus (EBV) lymphomas which develop in some leukemia patients post marrow transplantation. These T cells may be genetically modified by incorporation of a replication-incompetent viral vector (NIT) encoding both an inactive mutant nerve growth factor receptor (LNGFR), as an immunoselectable surface marker, and a herpes simplex virus thymidine kinase (HSV-TK), rendering the cells sensitive to ganciclovir. The current studies are based on the selective HSV-TK-catalyzed trapping (phosphorylation) of the thymidine analog [{sup 131}I]-2'-fluoro-2'-deoxy-1-{beta}-D-arabinofuransyl-5-iodo-uracil (FIAU) as a means of stably labeling such T cells for in vivo trafficking (including tumor targeting) studies. Because of the radiosensitivity of lymphocytes and the potentially high absorbed dose to the nucleus from intracellular {sup 131}I (even at tracer levels), the nucleus absorbed dose (D{sub n}) and dose-dependent immune functionality were evaluated for NIT {sup +} T cells labeled ex vivo in [{sup 131}I ]FIAU-containing medium. Based on in vitro kinetic studies of [{sup 131}I ]FIAU uptake by NIT {sup +} T cells, D{sub n} was calculated using an adaptation of the MIRD formalism and the recently published MIRD cellular S factors. Immune cytotoxicity of [{sup 131}I ]FIAU-labeled cells was assayed against {sup 51}Cr-labeled target cells [B-lymphoblastoid cells (BLCLs) ] in a standard 4-h release assay. At median nuclear absorbed doses up to 830 cGy, a {sup 51}Cr-release assay against BLCLs showed no loss of immune cytotoxicity, thus demonstrating the functional integrity of genetically transduced, tumor-reactive T cells labeled at this dose level for in vivo cell trafficking and tumor targeting studies. (orig.)

Protective effect of hexane and ethanol extract of piper longum L. On gentamicin-induced hair cell loss in neonatal cultures.

Science.gov (United States)

Yadav, Mukesh Kumar; Choi, June; Song, Jae-Jun

2014-03-01

Gentamicin (GM) is a commonly used aminoglycoside antibiotic that generates free oxygen radicals within the inner ear, which can cause vestibulo-cochlear toxicity and permanent damage to the sensory hair cells and neurons. Piper longum L. (PL) is a well-known spice and traditional medicine in Asia and Pacific islands, which has been reported to exhibit a wide spectrum of activity, including antioxidant activity. In this study, we evaluated the effect of hexane:ethanol (2:8) PL extract (subfraction of PL [SPL] extract) on GM-induced hair cell loss in basal, middle and apical regions in a neonatal cochlea cultures. The protective effects of SPL extract were measured by phalloidin staining of cultures from postnatal day 2-3 mice with GM-induced hair cell loss. The anti-apoptosis activity of SPL extract was measured using double labeling by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and myosin-7a staining. The radical-scavenging activity of SPL extract was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. SPL extract at a concentration of 1 µg/mL significantly inhibited GM-induced hair cell loss at basal and middle region of cochlea, while 5 µg/mL was effective against apical region hair cell loss. The protective effect of SPL extract was concentration dependent and hair cells retained their stereocilia in explants treated with SPL extract prior to treatment with 0.3 mM GM. SPL extract decreased GM-induced apoptosis of hair cells as assessed by TUNEL staining. The outer hair and inner hair counts were not decreased in SPL extract treated groups in compare to GM treated explants. Additionally, SPL extract showed concentration dependent radical scavenging activity in a DPPH assay. An anti-apoptosis effect and potent radical scavenger activity of SPL extract protects from GM-induced hair cell loss at basal, middle and apical regions in neonatal cochlea cultures.

Manifold regularized matrix completion for multi-label learning with ADMM.

Science.gov (United States)

Liu, Bin; Li, Yingming; Xu, Zenglin

2018-05-01

Multi-label learning is a common machine learning problem arising from numerous real-world applications in diverse fields, e.g, natural language processing, bioinformatics, information retrieval and so on. Among various multi-label learning methods, the matrix completion approach has been regarded as a promising approach to transductive multi-label learning. By constructing a joint matrix comprising the feature matrix and the label matrix, the missing labels of test samples are regarded as missing values of the joint matrix. With the low-rank assumption of the constructed joint matrix, the missing labels can be recovered by minimizing its rank. Despite its success, most matrix completion based approaches ignore the smoothness assumption of unlabeled data, i.e., neighboring instances should also share a similar set of labels. Thus they may under exploit the intrinsic structures of data. In addition, the matrix completion problem can be less efficient. To this end, we propose to efficiently solve the multi-label learning problem as an enhanced matrix completion model with manifold regularization, where the graph Laplacian is used to ensure the label smoothness over it. To speed up the convergence of our model, we develop an efficient iterative algorithm, which solves the resulted nuclear norm minimization problem with the alternating direction method of multipliers (ADMM). Experiments on both synthetic and real-world data have shown the promising results of the proposed approach. Copyright © 2018 Elsevier Ltd. All rights reserved.

A method for the determination of bacterial spore DNA content based on isotopic labelling, spore germination and diphenylamine assay; ploidy of spores of several Bacillus species

International Nuclear Information System (INIS)

Hauser, P.M.; Karamata, D.

1992-01-01

A reliable method for measuring the spore DNA content, based on radioactive DNA labelling, spore germination in absence of DNA replication and diphenylamine assay, was developed. The accuracy of the method, within 10 - 15%, is adequate for determining the number of chromosomes per spore, provided that the genome size is known. B subtilis spores were shown to be invariably monogenomic, while those of larger bacilli Bacillus megaterium, Bacillus cereus and Bacillus thuringiensis, often, if not invariably, contain two genomes. Attempts to modify the spore DNA content of B subtilis by altering the richness of the sporulation medium, the sporulation conditions (liquid or solid medium), or by mutation, were apparently unsuccessful. An increase of spore size with medium richness, not accompanied by an increase in DNA content, was observed. The implication of the apparently species-specific spore ploidy and the influence of the sporulation conditions on spore size and shape are discussed

From ‘Bad’ to ‘Mad’: Labelling and Behaviour in Peter Shaffer’s Equus

OpenAIRE

Méndez García, Carmen María