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Sulit AK, Daigneault M, Allen-Vercoe E, Silander OK, Hock B, McKenzie J, Pearson J, Frizelle FA, Schmeier S, Purcell R. Bacterial lipopolysaccharide modulates immune response in the colorectal tumor microenvironment. NPJ Biofilms Microbiomes 2023; 9:59. [PMID: 37612266 PMCID: PMC10447454 DOI: 10.1038/s41522-023-00429-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 08/15/2023] [Indexed: 08/25/2023] Open
Abstract
Immune responses can have opposing effects in colorectal cancer (CRC), the balance of which may determine whether a cancer regresses, progresses, or potentially metastasizes. These effects are evident in CRC consensus molecular subtypes (CMS) where both CMS1 and CMS4 contain immune infiltrates yet have opposing prognoses. The microbiome has previously been associated with CRC and immune response in CRC but has largely been ignored in the CRC subtype discussion. We used CMS subtyping on surgical resections from patients and aimed to determine the contributions of the microbiome to the pleiotropic effects evident in immune-infiltrated subtypes. We integrated host gene-expression and meta-transcriptomic data to determine the link between immune characteristics and microbiome contributions in these subtypes and identified lipopolysaccharide (LPS) binding as a potential functional mechanism. We identified candidate bacteria with LPS properties that could affect immune response, and tested the effects of their LPS on cytokine production of peripheral blood mononuclear cells (PBMCs). We focused on Fusobacterium periodonticum and Bacteroides fragilis in CMS1, and Porphyromonas asaccharolytica in CMS4. Treatment of PBMCs with LPS isolated from these bacteria showed that F. periodonticum stimulates cytokine production in PBMCs while both B. fragilis and P. asaccharolytica had an inhibitory effect. Furthermore, LPS from the latter two species can inhibit the immunogenic properties of F. periodonticum LPS when co-incubated with PBMCs. We propose that different microbes in the CRC tumor microenvironment can alter the local immune activity, with important implications for prognosis and treatment response.
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Affiliation(s)
- A K Sulit
- School of Natural Sciences, Massey University, Auckland, New Zealand.
- Department of Surgery and Critical Care, University of Otago, Christchurch, New Zealand.
| | - M Daigneault
- Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada
| | - E Allen-Vercoe
- Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada
| | - O K Silander
- School of Natural Sciences, Massey University, Auckland, New Zealand
| | - B Hock
- Haematology Research Group, University of Otago, Christchurch, New Zealand
| | - J McKenzie
- Haematology Research Group, University of Otago, Christchurch, New Zealand
| | - J Pearson
- Biostatistics and Computational Biology Unit, University of Otago, Christchurch, New Zealand
| | - F A Frizelle
- Department of Surgery and Critical Care, University of Otago, Christchurch, New Zealand
| | - S Schmeier
- School of Natural Sciences, Massey University, Auckland, New Zealand
- Evotec SE, Hamburg, Germany
| | - R Purcell
- Department of Surgery and Critical Care, University of Otago, Christchurch, New Zealand
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2
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Maestroni BM, Skerritt JH, Ferris IG, Ambrus A, Amin R, Bajet N, Dagher S, Genhai Y, Ghanem I, Guo J, Hock B, Jebakumar SRD, Maestroni B, Maqbool U, Matthews W, Merino R, Montoya A, Mukherjee PK, Prapamontol T, Skerritt J, Stanker L, Takyi E, Yücel Ü. Analysis of DDT Residues in Soil by ELISA: An International Interlaboratory Study. J AOAC Int 2019. [DOI: 10.1093/jaoac/84.1.134] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
An international interlaboratory study was conducted to determine the performance of a group of laboratories from developing and developed countries. The study used a commercial microwell ELISA on unknown samples spiked with different levels of DDT. The study design was based on Youden pairs and balanced replicates. Two soils, differing in particle size distributions, organic matter content, and cation-exchange capacities and thought to be DDT-free, were spiked at 5 DDT levels between 0.025 and 2 mg/kg. Nineteen laboratories in 17 countries took part in the collaborative trial; of these, the majority were modestly equipped laboratories in developing countries. Samples were analyzed without filtration or cleanup and using standards of pure DDT in methanol. Data were analyzed for repeatability and reproducibility, and average recoveries at the spike levels were calculated. Mean real recoveries for both soils were similar (103% for soil A and 100% for soil B), with values between 0.1 and 2 mg/kg DDT. Precision estimates were best in the linear working range of the assay (0.1–0.5 mg/kg DDT), with reproducibility relative standard deviations (RSDR) typically averaging about 38 and 46% near the upper and lower detection limits, respectively. Corresponding repeatability relative standard deviation (RSDr) values were 20–36% and 36–57%. Thus, even though much of the trial was performed under developing country conditions, performance statistics were similar to other reported results obtained with ELISAs on small molecules of agricultural importance, such as mycotoxins and pesticide and antibiotic residues.
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Affiliation(s)
- Britt M Maestroni
- Food and Agriculture Organization of the United Nations/International Atomic Energy Agency, Training and Reference Center for Food and Pesticide Control, Agriculture and Biotechnology Laboratory, A-2444 Seiberdorf, Austria
| | - John H Skerritt
- Australian Centre for International Agricultural Research, GPO Box 1571, Canberra ACT 2601, Australia
| | - Ian G Ferris
- Food and Agriculture Organization of the United Nations/International Atomic Energy Agency, Agriculture and Biotechnology Laboratory, A-2444 Seiberdorf, Austria
| | - Arpad Ambrus
- Food and Agriculture Organization of the United Nations/International Atomic Energy Agency, Agriculture and Biotechnology Laboratory, A-2444 Seiberdorf, Austria
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3
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Affiliation(s)
- C. Sautter
- Department of Botany, Faculty of Agriculture and Horticulture, Technical University of Munich, 8050 Freising 12, West Germany
| | - B. Hock
- Department of Botany, Faculty of Agriculture and Horticulture, Technical University of Munich, 8050 Freising 12, West Germany
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4
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Chua I, Liu J, Keating P, Hock B, Stamp L, Spellerberg M, O’Donnell J. P89: HIGH FREQUENCY OF ANTI-DRUG ANTIBODIES (ADA) DETECTED IN SERUM SAMPLES WITH LOW/ABSENT BIODRUG CONCENTRATIONS TAKEN FROM PATIENTS UNDERTAKING TREATMENT WITH ANTI-TNF AGENTS. Intern Med J 2017. [DOI: 10.1111/imj.89_13578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- I Chua
- Immunology section, Canterbury Health Laboratories; Christchurch New Zealand
| | - J Liu
- Immunology section, Canterbury Health Laboratories; Christchurch New Zealand
| | - P Keating
- Immunology section, Canterbury Health Laboratories; Christchurch New Zealand
| | - B Hock
- Department of Clinical Pharmacology, Christchurch Hospital; Christchurch New Zealand
| | - L Stamp
- Department of Rheumatology, Immunology and Allergy; Christchurch New Zealand
| | - M Spellerberg
- Immunology section, Canterbury Health Laboratories; Christchurch New Zealand
| | - J O’Donnell
- Immunology section, Canterbury Health Laboratories; Christchurch New Zealand
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5
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Sellmann C, Doerner A, Knuehl C, Rasche N, Sood V, Krah S, Rhiel L, Messemer A, Wesolowski J, Schuette M, Becker S, Toleikis L, Kolmar H, Hock B. Balancing Selectivity and Efficacy of Bispecific Epidermal Growth Factor Receptor (EGFR) × c-MET Antibodies and Antibody-Drug Conjugates. J Biol Chem 2016; 291:25106-25119. [PMID: 27694443 DOI: 10.1074/jbc.m116.753491] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 09/22/2016] [Indexed: 01/29/2023] Open
Abstract
Bispecific antibodies (bsAbs) and antibody-drug conjugates (ADCs) have already demonstrated benefits for the treatment of cancer in several clinical studies, showing improved drug selectivity and efficacy. In particular, simultaneous targeting of prominent cancer antigens, such as EGF receptor (EGFR) and c-MET, by bsAbs has raised increasing interest for potentially circumventing receptor cross-talk and c-MET-mediated acquired resistance during anti-EGFR monotherapy. In this study, we combined the selectivity of EGFR × c-MET bsAbs with the potency of cytotoxic agents via bispecific antibody-toxin conjugation. Affinity-attenuated bispecific EGFR × c-MET antibody-drug conjugates demonstrated high in vitro selectivity toward tumor cells overexpressing both antigens and potent anti-tumor efficacy. Due to basal EGFR expression in the skin, ADCs targeting EGFR in general warrant early safety assessments. Reduction in EGFR affinity led to decreased toxicity in keratinocytes. Thus, the combination of bsAb affinity engineering with the concept of toxin conjugation may be a viable route to improve the safety profile of ADCs targeting ubiquitously expressed antigens.
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Affiliation(s)
- Carolin Sellmann
- From the Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Alarich-Weiss-Strasse 4, D-64287 Darmstadt, Germany.,Protein Engineering and Antibody Technologies and
| | | | - Christine Knuehl
- Merck Research and Development, Merck KGaA, Frankfurter Strasse 250, D-64293 Darmstadt, Germany, and
| | | | - Vanita Sood
- the EMD Serono Research and Development Institute, Billerica, Massachusetts 01821
| | - Simon Krah
- From the Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Alarich-Weiss-Strasse 4, D-64287 Darmstadt, Germany.,Protein Engineering and Antibody Technologies and
| | - Laura Rhiel
- Protein Engineering and Antibody Technologies and
| | - Annika Messemer
- From the Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Alarich-Weiss-Strasse 4, D-64287 Darmstadt, Germany
| | - John Wesolowski
- the EMD Serono Research and Development Institute, Billerica, Massachusetts 01821
| | | | | | | | - Harald Kolmar
- From the Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Alarich-Weiss-Strasse 4, D-64287 Darmstadt, Germany,
| | - Bjoern Hock
- Protein Engineering and Antibody Technologies and
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Kobelt D, Karn T, Hock B, Holtrich U, Brauninger A, Wolf G, Strebhardt K, Rubsamenwaigmann K. Human and Xenopus mo15 messenger-RNA are highly conserved but show different patterns of expression in adult tissues. Oncol Rep 2012; 1:1269-75. [PMID: 21607529 DOI: 10.3892/or.1.6.1269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphorylation of human p34(cdc2) at Thr 161 seems to be necessary for its catalytic activity. CAK (cdk activating kinase) containing p40(MO15) from Xenopus egg extracts phosphorylates and activates p34(cdc2) in a cyclin dependent manner at Thr 161. We describe the cDNA sequence coding for human MO15, which predicts a serine/threonine kinase of 346 aa. Despite the high homology of 91% between the human and Xenopus proteins we observed a rather different mRNA distribution in adult tissues: In contrast to ubiquitously expressed human MO15-transcripts MO15-mRNA expression in Xenopus is restricted to oocytes indicating a different cellular role in these two phylogenetically distant species. By virtue of the homology to members of the family of cell cycle kinase genes we examined MO15 mRNA expression for its correlation to the proliferative activity of cells. Stimulation of lymphocytes showed MO15 mRNA expression to be independent of mitotic activity.
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Affiliation(s)
- D Kobelt
- GEORG SPEYER HAUS,CHEMOTHERAPEUT FORSCHUNGSINST,D-60596 FRANKFURT,GERMANY
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7
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Karn T, Holtrich U, Wolf G, Hock B, Strebhardt K, Rubsamenwaigmann H. Human SAK related to the PLK/polo family of cell cycle kinases shows high mRNA expression in testis. Oncol Rep 2012; 4:505-10. [PMID: 21590086 DOI: 10.3892/or.4.3.505] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We identified the nucleotide sequence of a cDNA encoding a polypeptide with a kinase domain that is related to the catalytic region of Drosophila melanogaster polo, Saccharomyces cerevisiae CDC5 as well as human FNK and PLK. The novel gene seems to represent the human counterpart of the mouse gene sak. The sequence of SAK predicts a serine/threonine kinase of 970 aa. The distribution of SAK mRNA in adult organs is restricted to certain tissues such as testis and thymus. Northern analyses of tumor tissues (lung, breast, brain) and corresponding normal tissues from the same patient did not reveal SAK expression. Comparing the mRNA distribution of the proliferation-associated polo-like kinase (PLK) with the expression of SAK we observed distinct differences. Thus, we suggest that these kinases have unique physiological roles in different cells or in response to different signals.
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Affiliation(s)
- T Karn
- GEORG SPEYER HAUS,CHEMOTHERAPEUT FORSCHUNGSINST,D-60596 FRANKFURT,GERMANY. BAYER AG,INST VIROL,D-42096 WUPPERTAL,GERMANY
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8
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Muda M, Gross AW, Dawson JP, He C, Kurosawa E, Schweickhardt R, Dugas M, Soloviev M, Bernhardt A, Fischer D, Wesolowski JS, Kelton C, Neuteboom B, Hock B. Therapeutic assessment of SEED: a new engineered antibody platform designed to generate mono- and bispecific antibodies. Protein Eng Des Sel 2011; 24:447-54. [PMID: 21498564 DOI: 10.1093/protein/gzq123] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The strand-exchange engineered domain (SEED) platform was designed to generate asymmetric and bispecific antibody-like molecules, a capability that expands therapeutic applications of natural antibodies. This new protein engineered platform is based on exchanging structurally related sequences of immunoglobulin within the conserved CH3 domains. Alternating sequences from human IgA and IgG in the SEED CH3 domains generate two asymmetric but complementary domains, designated AG and GA. The SEED design allows efficient generation of AG/GA heterodimers, while disfavoring homodimerization of AG and GA SEED CH3 domains. Using a clinically validated antibody (C225), we tested whether Fab derivatives constructed on the SEED platform retain desirable therapeutic antibody features such as in vitro and in vivo stability, favorable pharmacokinetics, ligand binding and effector functions including antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. In addition, we tested SEED with combinations of binder domains (scFv, VHH, Fab). Mono- and bivalent Fab-SEED fusions retain full binding affinity, have excellent biochemical and biophysical stability, and retain desirable antibody-like characteristics conferred by Fc domains. Furthermore, SEED is compatible with different combinations of Fab, scFv and VHH domains. Our assessment shows that the new SEED platform expands therapeutic applications of natural antibodies by generating heterodimeric Fc-analog proteins.
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Affiliation(s)
- Marco Muda
- EMD Serono Research Institute, Inc, One Technology Place, Rockland, MA 02370, USA
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9
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Segmiller F, Karch S, Merz H, Koller G, Hock B, Henning-Fast K, Cerovecki A, Riedel M, Pogarell O. Executive functions in patients with ADHD: An EEG-examination. Pharmacopsychiatry 2011. [DOI: 10.1055/s-0031-1292547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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10
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Abstract
Antibody-dependent cellular cytotoxicity plays a pivotal role in antibody-based tumor therapies and is based on the recruitment of natural killer cells to antibody-bound tumor cells via binding of the Fcγ receptor III (CD16). Here we describe the generation of chimeric DNA aptamers that simultaneously bind to CD16α and c-Met, a receptor that is overexpressed in many tumors. By application of the systematic evolution of ligands by exponential enrichment (SELEX) method, CD16α specific DNA aptamers were isolated that bound with high specificity and affinity (91 pm-195 nm) to their respective recombinant and cellularly expressed target proteins. Two optimized CD16α specific aptamers were coupled to each of two c-Met specific aptamers using different linkers. Bi-specific aptamers retained suitable binding properties and displayed simultaneous binding to both antigens. Moreover, they mediated cellular cytotoxicity dependent on aptamer and effector cell concentration. Displacement of a bi-specific aptamer from CD16α by competing antibody 3G8 reduced cytotoxicity and confirmed the proposed mode of action. These results represent the first gain of a tumor-effective function of two distinct oligonucleotides by linkage into a bi-specific aptamer mediating cellular cytotoxicity.
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Affiliation(s)
- Achim Boltz
- Clemens-Schoepf-Institute for Organic Chemistry and Biochemistry, Technical University Darmstadt, D-64289 Darmstadt, Germany
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11
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Segmiller F, Merz H, Bouna-Pyrrou P, Hock B, Cerovecki A, Opgen-Rhein M, Riedel M, Karch S, Pogarell O. Exekutive Funktionen bei Patienten mit ADHS: eine EEG-Untersuchung. KLIN NEUROPHYSIOL 2011. [DOI: 10.1055/s-0031-1272738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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12
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Abstract
BACKGROUND/OBJECTIVES Patients with alcohol abuse frequently suffer from malnutrition which may result in insufficient iron distribution and iron overload or deficiency. Iron metabolism can be described by a combination of biochemical soluble transferrin receptor, ferritin, C-reactive protein (CRP), and hematological parameters. Here, vitamin B12 and folic acid state were assessed. Results on iron metabolism in patients with alcohol dependence in comparison with social drinkers are presented. MATERIALS/METHODS Samples from 101 patients with dependent alcohol consumption were included. The control group comprised 115 social drinkers. Inclusion criteria for patients with chronic regular drinking/social drinkers were positive/negative score of the Alcohol Use Disorders Identification Test (AUDIT), and positive/negative score for alcohol abuse/dependence (DSM-IV criteria). RESULTS Absolute values for ferritin and sTfR are increased in patients with alcohol dependence with current consumption (ALC) compared with social drinkers. No major differences are observed in the ratio of sTfR/log ferritin in comparison with social drinkers. Hemoglobin concentrations correlated between the two groups. Mean corpuscular volume (MCV) was significantly increased in the ALC collective compared to social drinkers. Eighty patients of the alcohol-dependent group had sufficient iron repletion, 11 had iron overload, 6 are suspicious for functional iron deficiency, and 4 are suspicious for reduced iron supply. No vitamin B12/folate deficiencies are observed in alcohol-dependent patients. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE No major abnormalities of iron metabolism are seen in patients with chronic alcohol ingestion besides the well-known macrocytic anemia. Iron overload is relatively frequent and observed in 9% of cases. No differences in vitamin B12 and folate levels were found between individuals with alcohol dependence and social drinkers.
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Affiliation(s)
- M Lieb
- Department of Psychiatry, Ludwig-Maximilian-University, Munich, Germany.
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Sapbamrer R, Prapamontol T, Hock B. Assessment of estrogenic activity and total lipids in maternal biological samples (serum and breast milk). Ecotoxicol Environ Saf 2010; 73:679-684. [PMID: 19959230 DOI: 10.1016/j.ecoenv.2009.08.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 05/12/2009] [Accepted: 08/30/2009] [Indexed: 05/28/2023]
Abstract
The present study investigated estrogenic activity and total lipid levels in maternal serum and breast milk. The study was performed with 50 mothers from Fang district of northern Thailand. Maternal serum was collected 5 times, including the second trimester, pre-delivery period, delivery period, and lactating period at day 30 and day 60. Breast milk was collected 7 times, including day 1, 7, 14, 21, 30, 45, and 60 of lactation. There were the same patterns of variation between estrogenicity and total lipid levels both in serum and breast milk. The correlation between serum estrogenicity and serum total lipids was found with a correlation coefficient (r) ranging from 0.403 to 0.661. However, no correlation was found between milk estrogenicity and milk total lipids. The results therefore suggest that lipid contents might be the major factors affecting the variation of estrogenicity levels, and xenoestrogens, which the mother subjects exposed, were lipophilic pollutants. The remarkable findings were that the mean levels of estrogenicity in breast milk were approximately 8-13.5 times higher than those in maternal serum compared at the same period. However, no correlation was found between estrogenicity levels in serum and breast milk, leading to decreased accuracy in predicted infant exposure by maternal serum.
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Affiliation(s)
- R Sapbamrer
- School of Medicine, Naresuan University Phayao, Phayao 56000, Thailand.
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Mahlknecht G, Hock B, Kramer K. Development of a Monoclonal Antibody for the Detection of a Potentially Allergenic Epitope in Soy. ANAL LETT 2010. [DOI: 10.1080/00032710903276521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Karch S, Thalmeier T, Lutz J, Cerovecki A, Hock B, Opgen-Rhein M, Leicht G, Hennig-Fast K, Meindl T, Mulert C, Riedel M, Pogarell O. P02-150 - Behavioral control processes in adult ADHD: evidence from a simultaneous EEG/fMRI-study. Eur Psychiatry 2010. [DOI: 10.1016/s0924-9338(10)70764-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Merz H, Karch S, Koller G, Hock B, Opgen-Rhein M, Riedel M, Pogarell O. PW01-238 - Electrophysiological correlates of behavioural inhibition and decision making processes in patients with impulse control deficits. Eur Psychiatry 2010. [DOI: 10.1016/s0924-9338(10)71645-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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17
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Karch S, Thalmeier T, Lutz J, Cerovecki A, Hock B, Opgen-Rhein M, Leicht G, Hennig-Fast K, Meindl T, Mulert C, Riedel M, Pogarell O. Behavioral control in adult ADHD: evidence from a simultaneous EEG/fMRI-study. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)71939-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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18
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Geertsema L, Lucas SJE, Cotter JD, Hock B, McKenzie J, Fernyhough LJ. The cardiovascular risk factor, soluble CD40 ligand (CD154), but not soluble CD40 is lowered by ultra-endurance exercise in athletes. Br J Sports Med 2008; 45:42-5. [DOI: 10.1136/bjsm.2008.051896] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Karch S, Thalmeier T, Lutz J, Cerovecki A, Hock B, Leicht G, Born C, Mulert C, Riedel M, Pogarell O. Magnetic resonance imaging and event related potentials of performance monitoring in patients with attention deficit hyperactivity disorder. Pharmacopsychiatry 2007. [DOI: 10.1055/s-2007-991865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Thalmeier T, Karch S, Jäger L, Cerovecki A, Hock B, Lutz J, Leicht G, Hegerl U, Möller HJ, Riedel M, Reiser M, Mulert C, Pogarell O. Neurophysiologische und funktionell bildgebende Untersuchungen von Verhaltenskontrollprozessen bei Patienten mit Aufmerksamkeitsdefizit- und Hyperaktivitätsstörung. KLIN NEUROPHYSIOL 2007. [DOI: 10.1055/s-2007-976442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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21
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Lundell AC, Adlerberth I, Lindberg E, Karlsson H, Ekberg S, Aberg N, Saalman R, Hock B, Steinkasserer A, Hesselmar B, Wold AE, Rudin A. Increased levels of circulating soluble CD14 but not CD83 in infants are associated with early intestinal colonization with Staphylococcus aureus. Clin Exp Allergy 2007; 37:62-71. [PMID: 17210043 DOI: 10.1111/j.1365-2222.2006.02625.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Soluble forms of the monocyte marker CD14 and the mature dendritic cell marker CD83 are plasma proteins with immunoregulatory functions. The physiological stimulus for their production is unclear and their possible role in allergy development is unknown. METHODS We measured the plasma levels of soluble CD14 (sCD14) and soluble CD83 (sCD83) in 64 Swedish children in relation to intestinal bacterial colonization pattern in a prospective birth cohort. Soluble CD14 and sCD83 levels were quantified by enzyme linked immunosorbent assay in plasma obtained at birth and at 4, 18 and 36 months of age. All major aerobic and anaerobic bacteria were quantified in faecal samples obtained regularly over the first 8 weeks of life. Clinical allergy and IgE levels were evaluated at 18 months of age. RESULTS Soluble CD14 in plasma increased during the first 18 months of life while sCD83 peaked at 4 months of age. Children who were perinatally colonized with Staphylococcus aureus had significantly higher levels of sCD14 in plasma at 4 months of age relative to non-colonized children. The levels of sCD14 were unrelated to colonization with Escherichia coli, other enterobacteria, enterococci, clostridia, Bacteroides, bifidobacteria or lactobacilli. Further, children with food allergy by 18 months tended to have lower levels of sCD14 than healthy children. Plasma levels of sCD83 were not related to either bacterial colonization pattern or allergy development. CONCLUSIONS Perinatal colonization with S. aureus may trigger the occurrence of sCD14 in plasma, which may influence development of the infantile immune system and risk of allergy development.
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Affiliation(s)
- A-C Lundell
- Department of Rheumatology and Inflammation Research, The Sahigrenska Adademy, Göteborg, Sweden.
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Huber K, Krötz-Fahning M, Hock B. Respiratory burst as a biomarker for stress responses. Protoplasma 2006; 229:221-4. [PMID: 17180505 DOI: 10.1007/s00709-006-0206-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2005] [Accepted: 11/18/2005] [Indexed: 05/13/2023]
Abstract
A module for the detection of immunotoxic events within the test system Triple-Lux to be used during spaceflights was developed. It is based on the production of reactive oxygen species within the respiratory burst during phagocytosis or after stimulation of the phagocytes with phorbol 12-myristate 13-acetate (PMA). For this purpose, luminol-dependent chemiluminescence was measured. The assays were carried out with polymorphonuclear leukocytes purified from sheep peripheral blood. The influence of hydrocortisone and Cd2+ on the respiratory burst in polymorphonuclear leukocytes was assayed. Hydrocortisone in concentrations between 10(-4) and 10(-9) mol/liter showed an immunostimulating effect after PMA treatment. An immunosuppressive effect was observed for Cd2+ in concentrations between 10(-4) and 10(-7) mol/liter. Cryoconservation, which has often been critical for primary cells, can be accomplished without any subsequent loss of function by freezing the cells in dimethyl sulfoxide-containing medium.
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Affiliation(s)
- K Huber
- Chair of Cell Biology, Technische Universität München, Munich, Germany.
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Asawasinsopon R, Prapamontol T, Prakobvitayakit O, Vaneesorn Y, Mangklabruks A, Hock B. The association between organochlorine and thyroid hormone levels in cord serum: a study from northern Thailand. Environ Int 2006; 32:554-9. [PMID: 16492389 DOI: 10.1016/j.envint.2006.01.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Revised: 12/28/2005] [Accepted: 01/06/2006] [Indexed: 05/06/2023]
Abstract
It is now known that many organochlorines (OCs) act as endocrine disruptors, causing harmful effects on wildlife and humans. Several field and laboratory animal studies have reported that OCs cause adverse effects on thyroid hormone status. However, data regarding their effects on thyroid hormone status in humans are inconclusive. Because a developing fetus is especially sensitive to hormonal disruption by exposure to OCs, the adverse health effects on infants are of concern. The present study aimed to investigate the association between OC levels in maternal and cord serum, and the association between OC and thyroid hormone levels in cord serum. The study was performed with 39 mother-infant pairs from Mae Rim District of Chiang Mai Province, northern Thailand, who had normal delivery and full term gestation. Maternal blood was collected for measuring OCs and total lipids. Umbilical cord blood was collected for measuring OCs, total lipids, and thyroid hormones, including total thyroxine (TT(4)), free thyroxine (FT(4)), and thyroid stimulating hormone (TSH). 1,1-dichloro-2,2-di(4-chlorophenyl)ethylene (p,p'-DDE) had the highest level in all serum samples with a geometric mean of 1,191 ng/g lipids in maternal serum and 742 ng/g lipids in cord serum. The second highest level was that for 1,1,1-trichloro-2,2-di(4-chlorophenyl)ethane (p,p'-DDT), followed by 1,1-dichloro-2,2-di(4-chlorophenyl)ethane (p,p'-DDD). Levels of p,p'-DDE, p,p'-DDT, p,p'-DDD, and dieldrin in maternal serum were positively associated with levels in cord serum (r = 0.86, 0.77, 0.66, and 0.60, respectively; P<0.001). The important findings were that cord serum TT(4) levels were negatively associated with cord serum levels of p,p'-DDE (r = -0.37, P = 0.024), p,p'-DDT.3 (r = -0.33, P = 0.048), and 1,1-dichloro-2-(2-chlorophenyl)-2-(4-chlorophenyl)ethylene (o,p'-DDE) (r = -0.76, P = 0.019). These results therefore suggest that exposure to DDT and its metabolites during fetal development may cause some effects on thyroid hormonal status in infants.
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Affiliation(s)
- R Asawasinsopon
- Environmental Science Ph.D. Program, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
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Asawasinsopon R, Prapamontol T, Prakobvitayakit O, Vaneesorn Y, Mangklabruks A, Hock B. Plasma levels of DDT and their association with reproductive hormones in adult men from northern Thailand. Sci Total Environ 2006; 355:98-105. [PMID: 15964612 DOI: 10.1016/j.scitotenv.2005.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2004] [Accepted: 03/01/2005] [Indexed: 05/03/2023]
Abstract
Historically, dichlorodiphenyltrichloroethane (DDT) was used in northern Thailand for malaria control and farming purposes. Several studies have investigated its effects on end points of adverse reproductive health outcomes. However, the few previous studies investigated hormonal effects in men and available data are inconclusive. The authors aimed to explore the main hypothesis that plasma DDT levels in adult men were associated with reproductive hormone levels. A cross-sectional study was performed of 97 adult men living in a highland village named Mae Sa Mai, 35 km north of Chiang Mai, Thailand. Venous blood samples were collected for measuring plasma levels of DDT and its metabolites and reproductive hormones, including 17beta-estradiol (E2), testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH). 1,1-Dichloro-2,2-di(4-chlorophenyl)ethylene (p,p'-DDE) and 1,1,1-trichloro-2,2-di(4-chlorophenyl)ethane (p,p'-DDT) were detected in all plasma samples. p,p'-DDE had the highest level with a median of 4057.7 ng/g lipids and a relatively higher level compared with most other studies. Plasma p,p'-DDT levels were positively associated with years of residence (beta+SE=0.472+0.208, P=0.028) and years of DDT usage for farming (beta+SE=0.177+0.084, P=0.04). The remarkable findings were the negative association of plasma E2 levels with plasma p,p'-DDE levels (beta+SE=-7.093+2.899, P=0.016) and the positive association with plasma 1,1-dichloro-2-(2-chlorophenyl)-2-(4-chlorophynyl)ethylene (o,p'-DDE) levels (beta+SE=16.381+5.596, P=0.008) after adjusting for age and body mass index (BMI). However, these associations were rather weak. Our results suggest that these associations may reflect their different mechanisms of hormonal activities and they would be warrant further detail investigations.
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Affiliation(s)
- R Asawasinsopon
- Environmental Science Ph.D. Program, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
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Hock B, Schwarz M, Domke I, Grunert VP, Wuertemberger M, Schiemann U, Horster S, Limmer C, Stecker G, Soyka M. Validity of carbohydrate-deficient transferrin (%CDT), gamma-glutamyltransferase (gamma-GT) and mean corpuscular erythrocyte volume (MCV) as biomarkers for chronic alcohol abuse: a study in patients with alcohol dependence and liver disorders of non-alcoholic and alcoholic origin. Addiction 2005; 100:1477-86. [PMID: 16185209 DOI: 10.1111/j.1360-0443.2005.01216.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
AIM To test the clinical performance of carbohydrate-deficient transferrin (%CDT), gamma-glutamyltransferase (gamma-GT) and mean corpuscular erythrocyte volume (MCV) as biomarkers for alcoholism with a special focus on patients suffering from liver diseases. DESIGN Well-characterized collectives of alcohol-dependent patients with current consumption (ALC patients, n = 101), and relevant control groups (115 social drinkers, 46 patients with unspecifically increased gamma-GT, 51 hepatitis patients and 20/31 patients with non-alcohol/alcohol-dependent liver cirrhosis) were included into the study. The Positive Alcohol Use Disorders Test (AUDIT) score, International Classification of Diseases version 10 (ICD-10)/Diagnostic and Statistical Manual version IV (DSM-IV) criteria and blood drawn within 4 days of last drinking were inclusion criteria for subjects with regular heavy drinking. %CDT was determined using an automated assay which recently had been completely modified. FINDINGS Median AUDIT scores of patients without/with regular heavy drinking were 1-3/27. The following medians/95th percentiles were obtained for %CDT: social drinkers 2.2/3.0, patients with unspecifically increased gamma-GT 2.1/3.0, hepatitis 2.0/4.4, non-alcohol-dependent liver cirrhosis 2.4/4.8, alcohol-dependent liver cirrhosis 3.0/5.9, ALC patients 3.9/14.9. Differences between patients without and with alcohol abuse were highly significant (P < 0.001). No differences in CDT values were found between males and females. There was no correlation between %CDT values, gamma-GT, MCV and the amount of alcohol consumed in ALC patients; 3.0%CDT (95th percentile social drinkers) is proposed as cut-off for the test used (Tina-quant %CDT 2nd-generation). At this cut-off, the sensitivity for ALC patients was 73.3%, whereas gamma-GT/MCV had a sensitivity of 71.3%/64.4%. Multivariate analysis performed at 95% specificity resulted in an improvement of the sensitivity by combining %CDT with gamma-GT (83.2%). A further enhancement of the sensitivity to 88.1% was obtained by combination of %CDT, gamma-GT and MCV. The diagnostic specificity of %CDT calculated at the cut-off of 3% was 93.5% in patients with unspecifically increased gamma-GT, 88.2% in hepatitis patients and 70.0% in patients with non-alcohol-dependent liver cirrhosis. %CDT was more specific in these patient collectives than MCV, and especially more than gamma-GT (specificity in hepatitis 52.9%, and 35.0% in non-alcohol-dependent liver cirrhosis). CONCLUSION %CDT is of high diagnostic value to support diagnosis of alcohol-use disorders. The specificity of this marker in patient groups with liver disorders is superior to the biomarkers gamma-GT and MCV.
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Affiliation(s)
- B Hock
- Psychiatric Clinic of Ludwig-Maximilian-University, Munich, Germany.
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26
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Lieb M, Kagerer S, Hock B, Lehnert P, Limmer C, Soyka M. Cognitive function during substitution treatment. Pharmacopsychiatry 2005. [DOI: 10.1055/s-2005-918768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Lotierzo M, Henry OYF, Piletsky S, Tothill I, Cullen D, Kania M, Hock B, Turner APF. Surface plasmon resonance sensor for domoic acid based on grafted imprinted polymer. Biosens Bioelectron 2005; 20:145-52. [PMID: 15308215 DOI: 10.1016/j.bios.2004.01.032] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2003] [Revised: 01/26/2004] [Accepted: 01/26/2004] [Indexed: 11/29/2022]
Abstract
A molecularly imprinted polymer (MIP) film for domoic acid (DA) was synthesised by direct photo-grafting onto a gold chip suitable for a surface plasmon resonance (SPR) based bioanalytical instrument system, the BIAcore 3000. The gold surface was first functionalised with a self-assembled monolayer of 2-mercaptoethylamine and subsequent carbodiimide chemistry was performed for covalent attachment of the photoinitiator, 4,4'-azobis(cyanovaleric acid). This ensured that the formation of the MIP thin film, comprising 2-(diethylamino) ethyl methacrylate as functional monomer and ethylene glycol dimethacrylate as cross-linker, occurred only at the surface level. Optimisation and control over the grafting procedure were achieved using contact angle measurements and atomic force microscope (AFM) imaging. The surface grafting resulted in the formation of thin and homogeneous MIP film with thickness of 40 nm. A competitive binding assay was performed with free DA and its conjugate with horseradish peroxidase, which was used as a refractive label. The sensor was evaluated for its sensitivity, cross-reactivity, and robustness by using a BIAcore 3000. Likewise, monoclonal antibodies acting as natural receptors for the toxin were studied with the same BIAcore system. Results of a comparison between the artificial and natural receptors are reported. In contrast to monoclonal antibodies, the regeneration of MIP chip did not affect its recognition properties and continuous measurement was possible over a period of at least 2 months.
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Affiliation(s)
- M Lotierzo
- Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire MK45 4DT, UK
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Abstract
Initial steps of antibody engineering in the late eighties revolutionized the technology of antibody production, particularly in the area of immunotherapy and diagnostics. Hallmarks that seemed to be out of reach for a long time are now the state of the art, e.g. tailoring of antibodies to match particular needs or by-passing immunization by use of antibody libraries. Despite the apparent benefits of recombinant antibody technologies, this field has been opened up hesitantly for other applications. This review addresses the development of recombinant antibody synthesis in environmental analysis. Examples are given of the molecular evolution of pesticide antibodies and their application for the analysis of real samples.
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Affiliation(s)
- K Kramer
- Center of Life Sciences, Chair of Cell Biology, Technical University of Muenchen, Alte Akademie 12, 85350, Freising, Germany.
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Abstract
Biomonitoring is currently performed at two levels, assessing exposure to pollutants and effects monitoring by bioassays. As an example for the first approach, vitellogenin (VTG) in male fish of Abramis brama as an endpoint for estrogen exposure is discussed. However, similar changes of VTG or VTG-like proteins in the hemolymph of mussels could not be detected. Enzyme-linked receptor assays for monitoring estrogenic effects at the molecular level serve as an example for the second category. Applications of the enzyme-linked receptor assay (ELRA) developed in our laboratory are presented. Detection limits of 0.02 μg/l 17β-estradiol were recently achieved with the chemiluminescent format. Although effect monitoring provides information in terms of toxicity equivalents, it is not possible to relate the signals to specific pollutants and their concentrations. For this purpose, chemical analysis is required. New approaches are reported for the direct coupling of bioassays and chemical analysis. This concept is defined as bioresponse-linked instrumental analysis. It combines biomolecular recognition, initiating a biological effect, and chemical analysis. In addition to the classical bioanalytical approaches, new strategies in genomics and proteomics have been developed. This may lead to multimarker approaches opening this area to environmental analytics.
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Affiliation(s)
- M. Seifert
- 1Technische Universitaet Muenchen,Center of Life Sciences Weihenstephan, Chair of Cell Biology, Alte Akademie12, D-85350 Freising, Germany
| | - L. Wen
- 1Technische Universitaet Muenchen,Center of Life Sciences Weihenstephan, Chair of Cell Biology, Alte Akademie12, D-85350 Freising, Germany
| | - M. Alberti
- 1Technische Universitaet Muenchen,Center of Life Sciences Weihenstephan, Chair of Cell Biology, Alte Akademie12, D-85350 Freising, Germany
| | - U. Kausch
- 1Technische Universitaet Muenchen,Center of Life Sciences Weihenstephan, Chair of Cell Biology, Alte Akademie12, D-85350 Freising, Germany
| | - B. Hock
- 1Technische Universitaet Muenchen,Center of Life Sciences Weihenstephan, Chair of Cell Biology, Alte Akademie12, D-85350 Freising, Germany
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Maqbool U, Qureshi MJ, Iqbal MZ, Hock B, Kramer K. Development of ELISA technique for the analysis of atrazine residues in water. J Environ Sci Health B 2002; 37:307-322. [PMID: 12081023 DOI: 10.1081/pfc-120004472] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A highly sensitive enzyme immunoassay is described for the detection of atrazine residues in water. Atrazine derivative was conjugated to Bovine Serum Albumin (BSA) to obtain an immunizing antigen and to Horseradish Peroxidase enzyme (POD) to obtain a marker for immunoassay. The formation of these conjugations was confirmed by UV spectroscopy as well as by gel-electrophoresis. Polyclonal antibodies were raised in rabbits by immunization with an atrazine-BSA conjugate containing 29 atrazine residues per BSA molecule. An ELISA on microtitration plates was optimized with peroxidase-atrazine conjugate. The middle of the test (50% B/Bo) was found to be at 90 ng/l, which is well below the maximum concentration permitted by the EC guidelines for drinking water. Detection limits for atrazine of about 1 ng/l could be reached. The assay did not require concentration or cleanup steps for drinking or ground water samples. Validation experiments showed good accuracy and precision. No cross-reactivities were shown by other s-triazines like terbutryn, ametryn, terbuthylazine, des-isopropylatrazine, and de-ethylatrazine except hydroxyatrazine. The latter was present at very low levels that can be calibrated/standardized before analysis or it may be considered as leftover residues of atrazine. Based on these results, it is suggested that this test can be applied to obtain fairly accurate results for atrazine concentration in water samples from different sources.
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Affiliation(s)
- Uzma Maqbool
- Nuclear Institute for Agriculture and Biology, Faisalabad, Pakistan.
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31
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Abstract
Increased vitellogenin (vtg) levels in the blood of male fish are frequently used as an indicator of estrogenic exposure. Similar responses are expected for mussels, where the concentration of vtg-like proteins has been reported to depend on estrogens. To verify the role of hemolymph during vitellogenesis of mussels, the saltwater mussel Mytilus edulis and the freshwater mussel Anodonta cygnea were exposed to 17beta-estradiol (E2) and wastewater treatment plant effluents, known for their estrogenic potential. Gel electrophoresis did not reveal any significant induction (or repression) of plasma proteins compared to control plasma. Our results do not support the hypothesis that mussel hemolymph is a carrier of estrogen-dependent major egg-yolk precursors (vtg-like proteins). However, additional information on a 35+/-2-kDa hemolymph protein, previously reported to bind heavy metals, was obtained by high-resolution two-dimensional electrophoresis. It was resolved in a cluster of single proteins with properties that match the characteristics of a previously reported histidine-rich glycoprotein.
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Affiliation(s)
- M Riffeser
- Technische Universität München, Center of Life Sciences, Department of Plant Sciences, Alte Akademie 12, Freising, Germany.
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Abstract
Biosensor sensitivity and selectivity depend essentially on the properties of the biorecognition elements to be used for analyte binding. Two principally different applications are considered, (1) effects monitoring with biological components as targets for bioeffective substances, among them endocrine disruptors; and (2) immunochemical analysis employing antibodies as binding proteins for a wide variety of analytes such as pesticides. Genetic engineering provides an elegant way not only for providing unlimited amounts of biorecognition molecules but also for the alteration of existing properties and the supplementation with additional functions. Instrumental applications were carried out with the optical sensor BIAcore. The first example deals with the characterization of receptors. For this purpose, the human estrogen receptor alpha was used. Binding studies were carried out with natural as well as xenoestrogens. An equilibrium dissociation constant K(d) of 2.3x10(-10) (M) was derived for 17beta-estradiol. A competition assay was performed with a bovine serum albumin (BSA)-17beta-estradiol conjugate, immobilized at the optical sensor surface, and the free estrogen. The signals obtained represent estradiol equivalents. This format was transferred to a microplate-based enzyme-linked receptor assay. It reached a detection limit of 0.02 microg l(-1) 17beta-estradiol and proved suitable for the detection of natural and synthetic estrogens as well as xenoestrogens in field studies. The second example is targeted at kinetic and affinity measurements of recombinant antibody fragments derived from antibody libraries with s-triazine selectivities. Different strategies for the synthesis of antibody fragment libraries, followed by the selection of specific antibody variants, were examined. An antibody library was derived from a set of B cells. Chain shuffling of the heavy and light chains provided the best binders. An enzyme linked immunosorbent assay (ELISA) was achieved for atrazine with an IC(50) of 0.9 microg l(-1) and a detection limit of 0.2 microg l(-1). The close relations between the optimization of recombinant antibodies by evolutionary strategies and genetic algorithms are considered.
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Affiliation(s)
- B Hock
- Department of Botany, Technical University of Muenchen, Alte Akademie 12, D-85350 Freising, Germany.
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Dankwardt A, Hock B. Immunolocalization of non-extractable (bound) residues of pesticides and industrial contaminants in plants and soil. Chemosphere 2001; 45:523-533. [PMID: 11680748 DOI: 10.1016/s0045-6535(00)00603-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The application of immunochemical methods for the investigation of non-extractable (bound) residues is reviewed. Non-extractable residues may be presented to antibodies as antigenic determinants, which are exposed for instance in plant tissue and humic substances. Fluorescent probes as well as enzyme markers have been applied for the detection of bound residues. The application of antibodies labeled with fluorescein isothiocyanate (FITC) and phycoerythrin revealed the presence of atrazine in cryosections of atrazine-treated corn leaves and water plants. Atrazine could be localized by antibodies coupled to fluorescent markers in soil from corn fields but not in atrazine-free soil. Quantitative results were obtained by the application of enzyme immunoassays to the investigation of triazine and 2,4,6-trinitrotoluene (TNT) residues, bound to soil humic acids. Finally, the use of antibodies with different recognition patterns provides information on the ligation of non-extractable residues to the matrix.
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Affiliation(s)
- A Dankwardt
- Department of Botany, Alte Akademie 12, Technical University of Munich at Freising-Weihenstephan, Freising, Germany.
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Abstract
Monoclonal antibodies were developed against vitellogenin (vtg) of rainbow trout. This protein is used as a biochemical response to the exposure with estrogenic compounds. Several mice were immunized with purified vtg and the spleen cells of these mice were fused with myeloma cells. The resulting hybridoma cells were screened with an enzyme immunoassay for the production of specific anti-vtg antibodies. Twelve positive cell lines were detected. The hybridoma cell line B8D8 was adjusted to serum free medium; it produced monoclonal antibodies with a high selectivity and sensitivity. A detection limit of 5 microg/l vtg was achieved with a competitive enzyme immunoassay applying a preincubation step and a streptavidin-biotin amplification system (ABC system). Cross-reactivity with vtg of other species was detected with roach (Rutilus rutilus), flounder (Platichthys flesus) and dab (Limanda limanda). The assay was applied to rainbow trout (Oncorhynchus mykiss), which were exposed for six months to defined concentrations of effluents (10%, 20%, 30% and 40%) and surface water. Increased vtg levels in male fish are correlated with the increasing levels of effluent. The effluent levels in the exposure experiments are relevant for effluent loadings of the Berlin waterways during the seasons of the year.
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Affiliation(s)
- A Marx
- Department of Botany, Technische Universität of München, Freising, Germany
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35
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Kramer K, Lepschy J, Hock B. Long-term monitoring of atrazine contamination in soil by ELISA. J AOAC Int 2001; 84:150-5. [PMID: 11234802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
An enzyme-linked immunoassay (ELISA) was used for screening atrazine residues in soil. Samples were annually collected in Southern Germany between 1993 and 1998. An average of 419.5 samples was analyzed per year amounting to 2517 samples. The fraction of positive samples defined by atrazine concentrations >100 microg/kg soil decreased successively from 8% (corresponding to 33 samples) in 1993 to 0.6% (corresponding to 2 samples) in 1998. All positive samples and a selection of negative samples were subsequently validated by HPLC. Comparison of ELISA and HPLC data yielded correlation coefficient values of r = 0.958-0.981 (n = 18-47), except for 1995 when only a correlation of r = 0.864 (n = 18) was obtained. Four samples were overestimated and another 4 were underestimated with respect to the atrazine threshold value of 100 microg/kg soil as revealed by HPLC validation. Thus, 99.68% of 2,517 analyzed samples were correctly evaluated. The precision and reproducibility of the ELISA were adequate for a prescreening tool. The low cost per sample and the high sample throughput are not yet achievable by conventional analytical methods. The described combination of ELISA and HPLC has the potential to take advantage of both methods and to restrict determination errors to a minimum.
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Affiliation(s)
- K Kramer
- Technical University of Muenchen, Department of Botany, Freising, Germany
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Abstract
A monoclonal antibody (K3C6) was developed against Hg(II) and applied in different enzyme immunoassay (EIA) formats to determine the test system with the highest sensitivity. A detection limit of 1. 0 microg/L Hg(II) could be achieved with a competitive format in contrast to a detection limit of 2.1 microg/L Hg(II) with a noncompetitive EIA. A competitive displacement EIA yielded the best detection limit of 0.4 microg/L Hg(II) and was well suited to measuring real samples. For this purpose different water samples were diluted at least 1:10 to avoid matrix effects and subsequently spiked with 1 microg/L HgCl(2). Recovery of the spiked samples was between 80 and 120%.
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Affiliation(s)
- A Marx
- Department of Botany, Technische Universität München at Weihenstephan, Alte Akademie 12, Freising, D-85350, Germany
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Bilitewski U, Brenner-Weiß G, Hansen PD, Hock B, Meulenberg E, Müller G, Obst U, Sauerwein H, Scheller F, Schmid R, Schnabl G, Spener F. Bioresponse-linked instrumental analysis. Trends Analyt Chem 2000. [DOI: 10.1016/s0165-9936(00)00004-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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El Sherbini H, Hock B, Fearnley D, McLellan A, Vuckovic S, Hart DN. Lectin ligands on human dendritic cells and identification of a peanut agglutinin positive subset in blood. Cell Immunol 2000; 200:36-44. [PMID: 10716881 DOI: 10.1006/cimm.1999.1612] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
As only a few cell surface markers for dendritic cells (DC) have been identified to date, this study examined the expression of ligands for lectin on different human DC populations. The ability of Concanavalin A (Con A), Wheat Germ Agglutinin (WGA), peanut agglutinin (PNA), and Helix pomatia (HPA) to bind to cell lines and PBMC and DC populations was analyzed by flow cytometry and specificity of binding confirmed using inhibitory and noninhibitory sugars. The cell lines showed non-lineage-restricted binding with Con A and WGA, independent of sialidase treatment. HPA and PNA bound to a restricted number of lines, but showed broad reactivity after sialidase treatment. The peripheral blood mononuclear cells (PBMC) and directly isolated blood DC, activated CD83(+) blood DC, epidermal Langerhans cells (LC), and monocyte-derived DC (Mo-DC) showed strong binding of Con A and WGA, both before and after sialidase treatment. No HPA binding ligands were detected on PBMC populations, including directly isolated blood DC. Following sialidase treatment CD3(+), CD16(+), and a subset of CD19(+) lymphocytes bound HPA. The lectin PNA bound weakly to CD14(+) monocytes and a subpopulation of circulating DC that were HLA-DR(hi)CDw123 Dr(hi)CDw123(dim)/(neg)CD11c(+). The HLA-DR(mod)CDw123(hi)CD11c(neg) subpopulation did not bind PNA. Without sialidase treatment LC expressed both HPA and PNA ligands, but these were either absent on activated CD83(+) blood DC or weakly expressed on Mo-DC. Following sialidase treatment PBMC populations, activated CD83(+) blood DC, and Mo-DC became PNA positive. Thus human DC express several lectin ligands and PNA binding identifies a subset of blood DC. That may reflect discrete changes associated with stages of DC development or functional maturation.
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Affiliation(s)
- H El Sherbini
- Haematology/Immunology Research Group, Christchurch Hospital, Christchurch, New Zealand
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Hahn A, Hock B. Chromosome mechanics of fungi under spaceflight conditions--tetrad analysis of two-factor crosses between spore color mutants of Sordaria macrospora. FASEB J 1999; 13 Suppl:S149-56. [PMID: 10352157 DOI: 10.1096/fasebj.13.9001.s149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Spore color mutants of the fungus Sordaria macrospora Auersw. were crossed under spaceflight conditions on the space shuttle to MIR mission S/MM 05 (STS-81). The arrangement of spores of different colors in the asci allowed conclusions on the influence of spaceflight conditions on sexual recombination in fungi. Experiments on a 1-g centrifuge in space and in parallel on the ground were used for controls. The samples were analyzed microscopically on their return to earth. Each fruiting body was assessed separately. Statistical analysis of the data showed a significant increase in gene recombination frequencies caused by the heavy ion particle stream in space radiation. The lack of gravity did not influence crossing-over frequencies. Hyphae of the flown samples were assessed for DNA strand breaks. No increase in damage was found compared with the ground samples. It was shown that S. macrospora is able to repair radiation-induced DNA strand breaks within hours.
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Affiliation(s)
- A Hahn
- Technical University of Muenchen at Weihenstephan, Department of Botany, Freising, Germany.
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42
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Abstract
Receptor binding assays are a modern approach to the effects-related analysis of xenoendocrines. Human estrogen receptors are used to develop an analytical tool for the detection of estrogenic substances in environmental samples. A sensitive Enzyme Linked Receptor Assay (ELRA) was developed in a microwell plate format. The receptor assay is based on similar principles as competitive immunoassays (ELISA). However, receptor binding always implies a biological effect, either agonistic or antagonistic. The choice of suitable tracers or hapten conjugates is an important step in assay development. For this purpose and for the determination of receptor-affinities of relevant xenoestrogens, a surface plasmon resonance (SPR) biosensor (BIAcore) was used for binding studies with immobilized receptors. Results with commercially available hapten-conjugates (estradiol-BSA) show a direct correlation between the amount of immobilized estradiol receptor and the amount of bound hapten-conjugate. Based on these BIAcore experiments an ELRA was developed. The calibration curves show a detection limit of 0.1 microgram/l for 17 beta-estradiol. Cross-reactivities of different steroids and xenoestrogens are reported.
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Affiliation(s)
- M Seifert
- Department of Botany, Technical University of Muenchen, Freising/Weihenstephan, Germany
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Hock B, Böhme B, Karn T, Yamamoto T, Kaibuchi K, Holtrich U, Holland S, Pawson T, Rübsamen-Waigmann H, Strebhardt K. PDZ-domain-mediated interaction of the Eph-related receptor tyrosine kinase EphB3 and the ras-binding protein AF6 depends on the kinase activity of the receptor. Proc Natl Acad Sci U S A 1998; 95:9779-84. [PMID: 9707552 PMCID: PMC21413 DOI: 10.1073/pnas.95.17.9779] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Eph-related receptor tyrosine kinases (RTKs) have been implicated in intercellular communication during embryonic development. To elucidate their signal transduction pathways, we applied the yeast two-hybrid system. We could demonstrate that the carboxyl termini of the Eph-related RTKs EphA7, EphB2, EphB3, EphB5, and EphB6 interact with the PDZ domain of the ras-binding protein AF6. A mutational analysis revealed that six C-terminal residues of the receptors are involved in binding to the PDZ domain of AF6 in a sequence-specific fashion. Moreover, this PDZ domain also interacts with C-terminal sequences derived from other transmembrane receptors such as neurexins and the Notch ligand Jagged. In contrast to the association of EphB3 to the PDZ domain of AF6, the interaction with full-length AF6 clearly depends on the kinase activity of EphB3, suggesting a regulated mechanism for the PDZ-domain-mediated interaction. These data gave rise to the idea that the binding of AF6 to EphB3 occurs in a cooperative fashion because of synergistic effects involving different epitopes of both proteins. Moreover, in NIH 3T3 and NG108 cells endogenous AF6 is phosphorylated specifically by EphB3 and EphB2 in a ligand-dependent fashion. Our observations add the PDZ domain to the group of conserved protein modules such as Src-homology-2 (SH2) and phosphotyrosine-binding (PTB) domains that regulate signal transduction through their ability to mediate the interaction with RTKs.
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Affiliation(s)
- B Hock
- Chemotherapeutisches Forschungsinstitut, Georg-Speyer-Haus, Paul-Ehrlich-Strasse 42-44, 60596 Frankfurt, Germany
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44
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Hock B, Böhme B, Karn T, Feller S, Rübsamen-Waigmann H, Strebhardt K. Tyrosine-614, the major autophosphorylation site of the receptor tyrosine kinase HEK2, functions as multi-docking site for SH2-domain mediated interactions. Oncogene 1998; 17:255-60. [PMID: 9674711 DOI: 10.1038/sj.onc.1201907] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
HEK2 belongs to the family of EPH-related receptor tyrosine kinases (RTK) which are involved in axonal pathfinding and the formation of the embryonic body plan. The knowledge about intracellular pathways of signal transduction mediated by EPH-related receptors is still limited. Many of the known key players of cellular signalling contain Src homology 2 (SH2) domains, which recognize phosphotyrosine motifs in RTKs. Thus, we examined the interactions of various SH2-containing molecules like PLC-gamma1, rasGAP, p85 subunit of PI3-kinase, Src, Fyn, Crk, Nck, Grb2 and Shc with HEK2 using in vitro binding assays, immunoprecipitations and yeast Two-Hybrid assays. We found that rasGAP, Crk and Fyn bind in a SH2-dependent manner to autophosphorylated HEK2. rasGAP, which contains two SH2- and one SH3-domain, was shown to associate with its N-terminal SH2-domain to HEK2. Furthermore, we demonstrated that a single amino acid substitution (Y614F) clearly reduces the phosphotyrosine content of HEK2 and abrogates its ability to bind rasGAP, Crk and Fyn indicating that this residue functions as major phosphorylation and multi-docking site. The conservation of this predicted binding site among various EPH-related RTKs provides evidence that Fyn, Crk and rasGAP are key players in signal transduction of at least a subset of these receptors.
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Affiliation(s)
- B Hock
- Chemotherapeutisches Forschungsinstitut, Georg-Speyer-Haus, Frankfurt, Germany
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45
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Karn T, Hock B, Holtrich U, Adamski M, Strebhardt K, Rübsamen-Waigmann H. Nef proteins of distinct HIV-1 or -2 isolates differ in their binding properties for HCK: isolation of a novel Nef binding factor with characteristics of an adaptor protein. Virology 1998; 246:45-52. [PMID: 9656992 DOI: 10.1006/viro.1998.9157] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Nef gene of the human and simian immunodeficiency viruses HIV and SIV has been implicated in pathogenicity; however, the mechanism by which Nef induces disease is still unknown. An impact on signal transduction in cells has been suggested by the interaction of Nef from an HIV-1 strain and tyrosine kinases like HCK and LCK as well as serine/threonine kinases. We have confirmed the binding of HCK to HIV-1 subtype B Nef and demonstrated an equally strong interaction with a subtype E Nef protein but weaker binding to Nef of HIV-2 subtype A (HIV-2D194). No binding, however, was observed to HIV-2 subtype B Nef (HIV-2D205). Instead, this protein bound to a novel cellular protein, Nefin 1, with characteristics of an adaptor protein and strong expression in all human hematopoietic tissues. Nefin 1 binds through an amino-terminal domain, which is related to SH3 domains. For interaction of Nef with Nefin 1, the PxxP motif and the three-dimensional conformation of the molecule appear necessary. In conclusion, this study demonstrates that Nef proteins of divergent strains of HIV-1 and HIV-2 may use different elements of signal transduction pathways for the induction of pathogenicity in vivo.
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Affiliation(s)
- T Karn
- Chemotherapeutisches Forschungsinstitut, Frankfurt, Federal Republic of Germany
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46
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Abstract
In the present study our objective was to adapt a competitive enzyme immunoassay (EIA) for the determination of atrazine in animal tissues (liver and kidney). Female Wistar rats were administered through gavage with a single dose of atrazine (500 or 1000 mg/kg body weight) and sacrificed 24, 48 h and 7 days following the exposure. Using liver tissue samples the extraction procedure was improved. The atrazine concentrations measured in the liver were higher than those found in the kidney, but both can be ranked as low compared with the amount of the administered doses. These data confirm that tissue retention is minimal. Further studies are necessary in order to make an overall evaluation concerning the amount of atrazine retained in the organism. We consider that the competitive EIA may be a promising technique for epidemiological screening of pesticides.
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Affiliation(s)
- B Scutaru
- Department of Occupational Medicine, Institute of Public Health, Iasi, Romania.
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47
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Dankwardt A, Freitag D, Hock B. Approaches to the Immunochemical Analysis of Non-extractable Triazine Residues in Refractory Organic Substances (ROS) and Characterization of ROS. ACTA ACUST UNITED AC 1998. [DOI: 10.1002/(sici)1521-401x(199805)26:3<145::aid-aheh145>3.0.co;2-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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48
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Abstract
Immunoanalytical techniques used in combination with a highly sensitive Mach-Zender waveguide sensor give a device that is capable of fast on-line monitoring of immunoreactions. The on-line monitoring is especially attractive when the sensor can be used as an environmental probe. It is demonstrated that low concentrations of atrazine can be measured with a sensitivity around the EC limit of 100 ng/L. These measurements are performed with an inhibition technique. In combination with "a dynamic slope method" one complete measurement is done within 10 min. Sensor measurements show the same sensitivity and errors as parallel ELISAs.
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Affiliation(s)
- E F Schipper
- MESA Research Institute, Department of Applied Physics, University of Twente, Enschede, The Netherlands
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Kern VD, Rehm A, Hock B. Gravitropic bending of fruiting bodies--a model based on hyphal gravisensing and cooperativity. Adv Space Res 1998; 21:1173-1178. [PMID: 11541368 DOI: 10.1016/s0273-1177(97)00594-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Gravitropic bending of the winter mushroom Flammulina velutipes is achieved by differential growth of the apical part of the stem, the transition zone. Ultrastructural analysis revealed that bending is due to the relaxation of tissue tensions at the lower flank of the stem where hyphal extension growth is promoted in contrast to the upper flank. Extension of lower flank hyphae is preceded by a conspicuous accumulation of microvesicles in the cytosol and their subsequent fusion with the vacuolar compartment, leading to a large volume increase. The hypothesis is put forward that all hyphae in the transition zone are capable of gravisensing. It is derived from experiments with transition zone segments, which exhibit negative gravitropic response independent from their origin within the stem. A model is presented which connects individual gravisensing of the hyphae with a cooperative response within the stem or small segments of the stem. An essential step is the transmission of positional information, by each hypha with respect to the gravitational vector, to the surroundings. The existence of a soluble growth regulator, which is enriched at the lower flank of the stem, is discussed. A gradient could be formed which precedes the gradient of microvesicle formation, and thereby determines the change of growth direction.
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Affiliation(s)
- V D Kern
- Department of Botany, Technical University of Munchen at Weilhenstephan, Freising, Germany
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50
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Abstract
The hapten atrazine was detected under continuous flow conditions using a micro-column which contained immobilized monoclonal antibodies (Ab) against atrazine and atrazine labeled with alkaline phosphatase (An*). The equilibrium of the antibody-hapten system, was achieved by a continuous flow of the tracer An* through the micro-column containing the immobilized antibodies. The activity of the tracer was monitored continuously, after the micro-column, by an amperometric detector using p-hydroquinone phosphate as substrate. When pulses of unlabeled atrazine (An) were added to the An* flowing continuously through the micro-column, An* bound to the antibody was displaced, with a consequent change of the detector signal. By this method atrazine concentrations in the range 9-180 micrograms/l were monitored under conditions of continuous operation. Since the equilibrium condition for the system Ab-An* was continuously restored by the flow of An* through the micro-column the regeneration of the antibody was not required.
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Affiliation(s)
- F Vianello
- Department of Biological Chemistry, University of Padova, Italy
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