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Wong DP, Roy NK, Zhang K, Anukanth A, Asthana A, Shirkey-Son NJ, Dunmire S, Jones BJ, Lahr WS, Webber BR, Moriarity BS, Caimi P, Parameswaran R. A BAFF ligand-based CAR-T cell targeting three receptors and multiple B cell cancers. Nat Commun 2022; 13:217. [PMID: 35017485 PMCID: PMC8752722 DOI: 10.1038/s41467-021-27853-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 12/20/2021] [Indexed: 12/21/2022] Open
Abstract
B cell-activating factor (BAFF) binds the three receptors BAFF-R, BCMA, and TACI, predominantly expressed on mature B cells. Almost all B cell cancers are reported to express at least one of these receptors. Here we develop a BAFF ligand-based chimeric antigen receptor (CAR) and generate BAFF CAR-T cells using a non-viral gene delivery method. We show that BAFF CAR-T cells bind specifically to each of the three BAFF receptors and are effective at killing multiple B cell cancers, including mantle cell lymphoma (MCL), multiple myeloma (MM), and acute lymphoblastic leukemia (ALL), in vitro and in vivo using different xenograft models. Co-culture of BAFF CAR-T cells with these tumor cells results in induction of activation marker CD69, degranulation marker CD107a, and multiple proinflammatory cytokines. In summary, we report a ligand-based BAFF CAR-T capable of binding three different receptors, minimizing the potential for antigen escape in the treatment of B cell cancers.
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MESH Headings
- Animals
- Antigens, CD/genetics
- Antigens, CD/immunology
- Antigens, Differentiation, T-Lymphocyte/genetics
- Antigens, Differentiation, T-Lymphocyte/immunology
- B-Cell Activating Factor/genetics
- B-Cell Activating Factor/immunology
- B-Cell Activation Factor Receptor/genetics
- B-Cell Activation Factor Receptor/immunology
- B-Cell Maturation Antigen/genetics
- B-Cell Maturation Antigen/immunology
- B-Lymphocytes/immunology
- B-Lymphocytes/pathology
- Cell Line, Tumor
- Coculture Techniques
- Cytotoxicity, Immunologic
- Female
- Gene Expression Regulation, Neoplastic
- Humans
- Lectins, C-Type/genetics
- Lectins, C-Type/immunology
- Lymphocyte Activation
- Lymphoma, Mantle-Cell/genetics
- Lymphoma, Mantle-Cell/immunology
- Lymphoma, Mantle-Cell/pathology
- Lymphoma, Mantle-Cell/therapy
- Lysosomal-Associated Membrane Protein 1/genetics
- Lysosomal-Associated Membrane Protein 1/immunology
- Male
- Mice
- Multiple Myeloma/genetics
- Multiple Myeloma/immunology
- Multiple Myeloma/pathology
- Multiple Myeloma/therapy
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/immunology
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy
- Protein Binding
- Receptors, Chimeric Antigen/genetics
- Receptors, Chimeric Antigen/immunology
- Signal Transduction
- T-Lymphocytes/immunology
- T-Lymphocytes/transplantation
- Transmembrane Activator and CAML Interactor Protein/genetics
- Transmembrane Activator and CAML Interactor Protein/immunology
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Derek P Wong
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Nand K Roy
- Division of Hematology/Oncology, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Keman Zhang
- Division of Hematology/Oncology, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Anusha Anukanth
- Division of Pediatric Hematology/Oncology, Angie Fowler AYA Cancer Institute, UH Rainbow Babies & Children's Hospital, Cleveland, OH, USA
| | - Abhishek Asthana
- Division of Hematology/Oncology, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | | | | | | | - Walker S Lahr
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
- Stem Cell Institute, University of Minnesota, Minneapolis, MN, USA
| | - Beau R Webber
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
- Stem Cell Institute, University of Minnesota, Minneapolis, MN, USA
| | - Branden S Moriarity
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
- Stem Cell Institute, University of Minnesota, Minneapolis, MN, USA
| | - Paolo Caimi
- Division of Hematology/Oncology, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
- The Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Reshmi Parameswaran
- Division of Hematology/Oncology, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- The Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
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2
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Jones BJ, Evans RL, Mylrea NJ, Chaudhury D, Luo C, Guan B, Pierce CT, Gordon WR, Wilmot CM, Kazlauskas RJ. Larger active site in an ancestral hydroxynitrile lyase increases catalytically promiscuous esterase activity. PLoS One 2020; 15:e0235341. [PMID: 32603354 PMCID: PMC7326234 DOI: 10.1371/journal.pone.0235341] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/14/2020] [Indexed: 12/02/2022] Open
Abstract
Hydroxynitrile lyases (HNL's) belonging to the α/β-hydrolase-fold superfamily evolved from esterases approximately 100 million years ago. Reconstruction of an ancestral hydroxynitrile lyase in the α/β-hydrolase fold superfamily yielded a catalytically active hydroxynitrile lyase, HNL1. Several properties of HNL1 differ from the modern HNL from rubber tree (HbHNL). HNL1 favors larger substrates as compared to HbHNL, is two-fold more catalytically promiscuous for ester hydrolysis (p-nitrophenyl acetate) as compared to mandelonitrile cleavage, and resists irreversible heat inactivation to 35 °C higher than for HbHNL. We hypothesized that the x-ray crystal structure of HNL1 may reveal the molecular basis for the differences in these properties. The x-ray crystal structure solved to 1.96-Å resolution shows the expected α/β-hydrolase fold, but a 60% larger active site as compared to HbHNL. This larger active site echoes its evolution from esterases since related esterase SABP2 from tobacco also has a 38% larger active site than HbHNL. The larger active site in HNL1 likely accounts for its ability to accept larger hydroxynitrile substrates. Site-directed mutagenesis of HbHNL to expand the active site increased its promiscuous esterase activity 50-fold, consistent with the larger active site in HNL1 being the primary cause of its promiscuous esterase activity. Urea-induced unfolding of HNL1 indicates that it unfolds less completely than HbHNL (m-value = 0.63 for HNL1 vs 0.93 kcal/mol·M for HbHNL), which may account for the ability of HNL1 to better resist irreversible inactivation upon heating. The structure of HNL1 shows changes in hydrogen bond networks that may stabilize regions of the folded structure.
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Affiliation(s)
- Bryan J. Jones
- Department of Biochemistry, Molecular Biology and Biophysics and The Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Robert L. Evans
- Department of Biochemistry, Molecular Biology and Biophysics and The Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Nathan J. Mylrea
- Department of Biochemistry, Molecular Biology and Biophysics and The Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Debayan Chaudhury
- Department of Biochemistry, Molecular Biology and Biophysics and The Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Christine Luo
- Department of Biochemistry, Molecular Biology and Biophysics and The Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Bo Guan
- Department of Biochemistry, Molecular Biology and Biophysics and The Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Colin T. Pierce
- Department of Biochemistry, Molecular Biology and Biophysics and The Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Wendy R. Gordon
- Department of Biochemistry, Molecular Biology and Biophysics and The Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Carrie M. Wilmot
- Department of Biochemistry, Molecular Biology and Biophysics and The Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Romas J. Kazlauskas
- Department of Biochemistry, Molecular Biology and Biophysics and The Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
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Abstract
AbstractObjectiveCurrent and past research strongly indicates a high prevalence of schizophrenia in the lower class in the USA and other stratified societies. To date, no study has tested for a connection between type of schizophrenia and socioeconomic status (SES). We tested for an interrelationship between schizophrenic subtype, SES and race.MethodsPositive and negative symptom scales were used to evaluate 436 schizophrenic patients at a state hospital in the USA. All patients were also diagnosed by DSM standards. Social class of origin was assessed by the Occupational Classification Distributions of the U.S. Bureau of the Census. Multivariate analysis was conducted with the likelihood ratio chi-square.ResultsWe uncovered a distinct propensity for deficit schizophrenia to be elevated among the poor. The finding presents as a pure SES effect since the likelihood of deficit schizophrenia does not vary by race when social class is held constant.ConclusionThe finding is potentially an important new insight into the epidemiology of schizophrenia. It offers a better understanding for poor outcome among lower class patients in stratified societies such as the United States. It is also consistent with longitudinal research by European investigators.
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Affiliation(s)
- B J Gallagher
- Department of Sociology, Villanova University, Villanova, PA 19085, USA.
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4
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Jones BJ, Evans RL, Mylrea NJ, Chaudhury D, Luo C, Guan B, Pierce CT, Gordon WR, Wilmot CM, Kazlauskas RJ. Larger active site in an ancestral hydroxynitrile lyase increases catalytically promiscuous esterase activity.. [DOI: 10.1101/2020.04.06.027797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
Abstract
AbstractHydroxynitrile lyases (HNL’s) belonging to the α/β-hydrolase-fold superfamily evolved from esterases approximately 100 million years ago. Reconstruction of an ancestral hydroxynitrile lyase in the α/β-hydrolase fold superfamily yielded a catalytically active hydroxynitrile lyase, HNL1. Several properties of HNL1 differ from the modern HNL from rubber tree (HbHNL). HNL1 favors larger substrates as compared to HbHNL, is two-fold more catalytically promiscuous for ester hydrolysis (p-nitrophenyl acetate) as compared to mandelonitrile cleavage, and resists irreversible heat inactivation to 35 °C higher than for HbHNL. We hypothesized that the x-ray crystal structure of HNL1 may reveal the molecular basis for the differences in these properties. The x-ray crystal structure solved to 1.96-Å resolution shows the expected α/β-hydrolase fold, but a 60% larger active site as compared to HbHNL. This larger active site echoes its evolution from esterases since related esterase SABP2 from tobacco also has a 38% larger active site than HbHNL. The larger active site in HNL1 likely accounts for its ability to accept larger hydroxynitrile substrates. Site-directed mutagenesis of HbHNL to expand the active site increased its promiscuous esterase activity 50-fold, consistent with the larger active site in HNL1 being the primary cause of its promiscuous esterase activity. Urea-induced unfolding of HNL1 indicates that it unfolds less completely than HbHNL (m-value = 0.63 for HNL1 vs 0.93 kcal/ mol·M for HbHNL), which may account for the ability of HNL1 to better resist irreversible inactivation upon heating. The structure of HNL1 shows changes in hydrogen bond networks that may stabilize regions of the folded structure.
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6
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Jones BJ, Chappel-Farley MG, Madala KS, Spencer RM. 0105 Effect of Targeted Memory Reactivation during Sleep on Visuospatial Memory in Young And Older Adults. Sleep 2018. [DOI: 10.1093/sleep/zsy061.104] [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: 11/13/2022] Open
Affiliation(s)
- B J Jones
- University of Massachusetts, Amherst, Amherst, MA
| | | | - K S Madala
- University of Massachusetts, Amherst, Amherst, MA
| | - R M Spencer
- University of Massachusetts, Amherst, Amherst, MA
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7
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Abstract
A review of the previous stabilization of α/β-hydrolase fold enzymes revealed many different strategies, but no comparison of strategies on the same enzyme. For this reason, we compared five strategies to identify stabilizing mutations in a model α/β-hydrolase fold enzyme, salicylic acid binding protein 2, to reversible denaturation by urea and to irreversible denaturation by heat. The five strategies included one location agnostic approach (random mutagenesis using error-prone polymerase chain reaction), two structure-based approaches [computational design (Rosetta, FoldX) and mutation of flexible regions], and two sequence-based approaches (addition of proline at locations where a more stable homologue has proline and mutation to consensus). All strategies identified stabilizing mutations, but the best balance of success rate, degree of stabilization, and ease of implementation was mutation to consensus. A web-based automated program that predicts substitutions needed to mutate to consensus is available at http://kazlab.umn.edu .
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Affiliation(s)
- Bryan J Jones
- Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, University of Minnesota , 1479 Gortner Avenue, Saint Paul, Minnesota 55108, United States
| | - Huey Yee Lim
- Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, University of Minnesota , 1479 Gortner Avenue, Saint Paul, Minnesota 55108, United States
| | - Jun Huang
- Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, University of Minnesota , 1479 Gortner Avenue, Saint Paul, Minnesota 55108, United States.,School of Biological and Chemical Engineering, Zhejiang University of Science and Technology , Hangzhou 310023, People's Republic of China
| | - Romas J Kazlauskas
- Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, University of Minnesota , 1479 Gortner Avenue, Saint Paul, Minnesota 55108, United States
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8
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Jones BJ, Bata Z, Kazlauskas RJ. Identical active sites in hydroxynitrile lyases show opposite enantioselectivity and reveal possible ancestral mechanism. ACS Catal 2017; 7:4221-4229. [PMID: 28798888 DOI: 10.1021/acscatal.7b01108] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Evolutionarily related hydroxynitrile lyases from rubber tree (HbHNL) and from Arabidopsis thaliana (AtHNL) follow different catalytic mechanisms with opposite enantioselectivity toward mandelonitrile. We hypothesized that the HbHNL-like mechanism evolved from an enzyme with an AtHNL-like mechanism. We created ancestor-like composite active-sites in each scaffold to elucidate how this transition may have occurred. Surprisingly, a composite active site in HbHNL maintained (S)-selectivity, while the identical set of active site residues in AtHNL maintained (R)-selectivity. Composite active-site mutants that are (S)-selective without the Lys236 and Thr11 that are required for the classical (S)-HNL mechanism suggests a new mechanism. Modeling suggested a possibility for this new mechanism that does not exist in modern enzymes. Thus, the last common ancestor of HbHNL and AtHNL may have used an extinct mechanism, not the AtHNL-like mechanism. Multiple mechanisms are possible with the same catalytic residues and residues outside the active site strongly influence mechanism and enantioselectivity.
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Affiliation(s)
- Bryan J. Jones
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, 1479 Gortner Avenue, Saint Paul, Minnesota 55108, United States
| | - Zsófia Bata
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, 1479 Gortner Avenue, Saint Paul, Minnesota 55108, United States
- Department
of Organic Chemistry and Technology, Budapest University of Technology and Economics, 3 Műegyetem rkp, H-1111 Budapest, Hungary
| | - Romas J. Kazlauskas
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, 1479 Gortner Avenue, Saint Paul, Minnesota 55108, United States
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Corona FE, Jones BJ, Spencer RM. 0242 THE EFFECT OF SLEEP ON EMOTIONAL REACTIVITY AND NEGATIVE MEMORY IN OLDER ADULTS. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.241] [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: 11/13/2022] Open
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10
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Chappel-Farley MG, Madala KS, Jones BJ, Spencer RM. 0211 ENHANCING MEMORY CONSOLIDATION WITH TARGETED MEMORY REACTIVATION DURING SLEEP. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.210] [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: 11/14/2022] Open
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11
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Jones BJ, Fitzroy AB, Spencer RM. 0247 SLEEP PRESERVES EMOTIONAL REACTIVITY FOR NEGATIVE MEMORIES. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.246] [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: 11/14/2022] Open
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Devamani T, Rauwerdink AM, Lun-zer M, Jones BJ, Mooney JL, Tan MAO, Zhang ZJ, Xu JH, Dean AM, Kazlauskas RJ. Catalytic Promiscuity of Ancestral Esterases and Hydroxynitrile Lyases. J Am Chem Soc 2016; 138:1046-56. [PMID: 26736133 PMCID: PMC5466365 DOI: 10.1021/jacs.5b12209] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Catalytic promiscuity is a useful, but accidental, enzyme property, so finding catalytically promiscuous enzymes in nature is inefficient. Some ancestral enzymes were branch points in the evolution of new enzymes and are hypothesized to have been promiscuous. To test the hypothesis that ancestral enzymes were more promiscuous than their modern descendants, we reconstructed ancestral enzymes at four branch points in the divergence hydroxynitrile lyases (HNL's) from esterases ∼ 100 million years ago. Both enzyme types are α/β-hydrolase-fold enzymes and have the same catalytic triad, but differ in reaction type and mechanism. Esterases catalyze hydrolysis via an acyl enzyme intermediate, while lyases catalyze an elimination without an intermediate. Screening ancestral enzymes and their modern descendants with six esterase substrates and six lyase substrates found higher catalytic promiscuity among the ancestral enzymes (P < 0.01). Ancestral esterases were more likely to catalyze a lyase reaction than modern esterases, and the ancestral HNL was more likely to catalyze ester hydrolysis than modern HNL's. One ancestral enzyme (HNL1) along the path from esterase to hydroxynitrile lyases was especially promiscuous and catalyzed both hydrolysis and lyase reactions with many substrates. A broader screen tested mechanistically related reactions that were not selected for by evolution: decarboxylation, Michael addition, γ-lactam hydrolysis and 1,5-diketone hydrolysis. The ancestral enzymes were more promiscuous than their modern descendants (P = 0.04). Thus, these reconstructed ancestral enzymes are catalytically promiscuous, but HNL1 is especially so.
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Affiliation(s)
- Titu Devamani
- University of Minnesota, Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, 1479 Gortner Avenue, Saint Paul, MN 55108 USA
| | - Alissa M. Rauwerdink
- University of Minnesota, Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, 1479 Gortner Avenue, Saint Paul, MN 55108 USA
| | - Mark Lun-zer
- University of Minnesota, Department of Ecology, Evolution & Behavior and The Biotechnology Institute, 1479 Gortner Avenue, Saint Paul, MN 55108 USA
| | - Bryan J. Jones
- University of Minnesota, Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, 1479 Gortner Avenue, Saint Paul, MN 55108 USA
| | - Joanna L. Mooney
- University of Minnesota, Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, 1479 Gortner Avenue, Saint Paul, MN 55108 USA
| | | | - Zhi-Jun Zhang
- East China University of Science and Technology, School of Biotechnology, Meilong Road 130, Shanghai 200237 P. R. China
| | - Jian-He Xu
- East China University of Science and Technology, School of Biotechnology, Meilong Road 130, Shanghai 200237 P. R. China
| | - Antony M. Dean
- University of Minnesota, Department of Ecology, Evolution & Behavior and The Biotechnology Institute, 1479 Gortner Avenue, Saint Paul, MN 55108 USA
- Sun Yat-sen University, Institute of Ecology and Evolution, No.135, Xinggang West Road, Guangzhou, 510275 P. R. China
| | - Romas J. Kazlauskas
- University of Minnesota, Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, 1479 Gortner Avenue, Saint Paul, MN 55108 USA
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Rajendran R, Sherry L, Nile CJ, Sherriff A, Johnson EM, Hanson MF, Williams C, Munro CA, Jones BJ, Ramage G. Biofilm formation is a risk factor for mortality in patients with Candida albicans bloodstream infection-Scotland, 2012-2013. Clin Microbiol Infect 2015; 22:87-93. [PMID: 26432192 PMCID: PMC4721535 DOI: 10.1016/j.cmi.2015.09.018] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 08/25/2015] [Accepted: 09/17/2015] [Indexed: 11/23/2022]
Abstract
Bloodstream infections caused by Candida species remain a significant cause of morbidity and mortality in hospitalized patients. Biofilm formation by Candida species is an important virulence factor for disease pathogenesis. A prospective analysis of patients with Candida bloodstream infection (n = 217) in Scotland (2012–2013) was performed to assess the risk factors associated with patient mortality, in particular the impact of biofilm formation. Candida bloodstream isolates (n = 280) and clinical records for 157 patients were collected through 11 different health boards across Scotland. Biofilm formation by clinical isolates was assessed in vitro with standard biomass assays. The role of biofilm phenotype on treatment efficacy was also evaluated in vitro by treating preformed biofilms with fixed concentrations of different classes of antifungal. Available mortality data for 134 patients showed that the 30-day candidaemia case mortality rate was 41%, with predisposing factors including patient age and catheter removal. Multivariate Cox regression survival analysis for 42 patients showed a significantly higher mortality rate for Candida albicans infection than for Candida glabrata infection. Biofilm-forming ability was significantly associated with C. albicans mortality (34 patients). Finally, in vitro antifungal sensitivity testing showed that low biofilm formers and high biofilm formers were differentially affected by azoles and echinocandins, but not by polyenes. This study provides further evidence that the biofilm phenotype represents a significant clinical entity, and that isolates with this phenotype differentially respond to antifungal therapy in vitro. Collectively, these findings show that greater clinical understanding is required with respect to Candida biofilm infections, and the implications of isolate heterogeneity.
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Affiliation(s)
- R Rajendran
- School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - L Sherry
- School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - C J Nile
- School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - A Sherriff
- School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - E M Johnson
- Public Health England, Southwest Laboratory, Bristol, UK
| | | | - C Williams
- University of the West of Scotland, Glasgow, UK
| | - C A Munro
- University of Aberdeen, Aberdeen, UK
| | - B J Jones
- Microbiology Department, Glasgow Royal Infirmary, Glasgow, UK
| | - G Ramage
- School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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14
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Abstract
α/β-Hydrolases are important enzymes for biocatalysis, but their stability often limits their application. We investigated a plant esterase, salicylic acid binding protein 2 (SABP2), as a model α/β-hydrolase. SABP2 shows typical stability to urea (unfolding free energy 6.9 ± 1.5 kcal/mol) and to heat inactivation (T1/2 15min 49.2 ± 0.5 °C). Denaturation in urea occurs in two steps, but heat inactivation occurs in a single step. The first unfolding step in urea eliminates catalytic activity. Surprisingly, we found that the first unfolding likely corresponds to the unfolding of the larger catalytic domain. Replacing selected amino acid residues with proline stabilized SABP2. Proline restricts the flexibility of the unfolded protein, thereby shifting the equilibrium toward the folded conformation. Seven locations for proline substitution were chosen either by amino acid sequence alignment with a more stable homologue or by targeting flexible regions in SABP2. Introducing proline in the catalytic domain stabilized SABP2 to the first unfolding in urea for three of five cases: L46P (+0.2 M urea), S70P (+0.1), and E215P (+0.9). Introducing proline in the cap domain did not stabilize SABP2 (two of two cases), supporting the assignment that the first unfolding corresponds to the catalytic domain. Proline substitutions in both domains stabilized SABP2 to heat inactivation: L46P (ΔT1/2 15min = +6.4 °C), S70P (+5.4), S115P (+1.8), S141P (+4.9), and E215P (+4.2). Combining substitutions did not further increase the stability to urea denaturation, but dramatically increased resistance to heat inactivation: L46P−S70P ΔT1/2 15min = +25.7 °C. This straightforward proline substitution approach may also stabilize other α/β-hydrolases.
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Affiliation(s)
- Jun Huang
- Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, University of Minnesota, 1479 Gortner Avenue, Saint Paul MN 55108 USA
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou 310023, PR China
| | - Bryan J. Jones
- Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, University of Minnesota, 1479 Gortner Avenue, Saint Paul MN 55108 USA
| | - Romas J. Kazlauskas
- Department of Biochemistry, Molecular Biology & Biophysics and The Biotechnology Institute, University of Minnesota, 1479 Gortner Avenue, Saint Paul MN 55108 USA
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15
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Brosnahan AJ, Jones BJ, Dvorak CM, Brown DR. Morphine attenuates apically-directed cytokine secretion from intestinal epithelial cells in response to enteric pathogens. Pathogens 2014; 3:249-57. [PMID: 25437799 PMCID: PMC4243445 DOI: 10.3390/pathogens3020249] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/17/2014] [Accepted: 03/20/2014] [Indexed: 01/19/2023] Open
Abstract
Epithelial cells represent the first line of host immune defense at mucosal surfaces. Although opioids appear to increase host susceptibility to infection, no studies have examined opioid effects on epithelial immune functions. We tested the hypothesis that morphine alters vectorial cytokine secretion from intestinal epithelial cell (IPEC-J2) monolayers in response to enteropathogens. Both entero-adherent Escherichia coli O157:H7 and entero-invasive Salmonella enterica serovar Typhimurium increased apically-directed IL-6 secretion and bi-directional IL-8 secretion from epithelial monolayers, but only IL-6 secretion evoked by E. coli was reduced by morphine acting through a naloxone-sensitive mechanism. Moreover, the respective type 4 and 5 Toll-like receptor agonists, lipopolysaccharide and flagellin, increased IL-8 secretion from monolayers, which was also attenuated by morphine pretreatment. These results suggest that morphine decreases cytokine secretion and potentially phagocyte migration and activation directed towards the mucosal surface; actions that could increase host susceptibility to some enteric infections.
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Affiliation(s)
- Amanda J Brosnahan
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 1988 Fitch Avenue, Saint Paul, MN 55108-6010, USA.
| | - Bryan J Jones
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 1988 Fitch Avenue, Saint Paul, MN 55108-6010, USA.
| | - Cheryl M Dvorak
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 1988 Fitch Avenue, Saint Paul, MN 55108-6010, USA.
| | - David R Brown
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 1988 Fitch Avenue, Saint Paul, MN 55108-6010, USA.
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Brosnahan AJ, Vulchanova L, Witta SR, Dai Y, Jones BJ, Brown DR. Norepinephrine potentiates proinflammatory responses of human vaginal epithelial cells. J Neuroimmunol 2013; 259:8-16. [PMID: 23571017 DOI: 10.1016/j.jneuroim.2013.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 03/11/2013] [Accepted: 03/15/2013] [Indexed: 11/17/2022]
Abstract
The vaginal epithelium provides a barrier to pathogens and recruits immune defenses through the secretion of cytokines and chemokines. Several studies have shown that mucosal sites are innervated by norepinephrine-containing nerve fibers. Here we report that norepinephrine potentiates the proinflammatory response of human vaginal epithelial cells to products produced by Staphylococcus aureus, a pathogen that causes menstrual toxic shock syndrome. The cells exhibit immunoreactivity for catecholamine synthesis enzymes and the norepinephrine transporter. Moreover, the cells secrete norepinephrine and dopamine at low concentrations. These results indicate that norepinephrine may serve as an autocrine modulator of proinflammatory responses in the vaginal epithelium.
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Affiliation(s)
- Amanda J Brosnahan
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 75 Animal Science/Veterinary Medicine, 1988 Fitch Ave, Saint Paul, MN 55108, United States
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Abstract
Glucagon is traditionally thought of as an antihypoglycemic hormone, for example in response to starvation. However, it actually increases energy expenditure and has other actions not in line with protection from hypoglycemia. Furthermore, it is often found to be elevated when glucose is also raised, for example in circumstances of psychological and metabolic stress. These findings seem more in keeping with glucagon having some role as a hormone enhancing the response to stress.
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Affiliation(s)
- B J Jones
- Department of Investigative Medicine, Commonwealth Building, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0HS, United Kingdom
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Walsh APH, Yokota TT, Walsh DJ, Jones BJ, Coull GD, Sills ES. First reported deliveries in Ireland using surgically retrieved sperm for non-obstructive azoospermia. Ir J Med Sci 2010; 180:251-3. [PMID: 20963511 DOI: 10.1007/s11845-010-0613-0] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Accepted: 09/17/2010] [Indexed: 11/26/2022]
Abstract
Couples presenting with male factor infertility comprise an important proportion of clinical reproductive endocrinology consultations. Indeed, a problem with the male is the only cause, or a contributing cause, of infertility in ~40% of infertility evaluations. Here we present the first published deliveries obtained from IVF utilising surgically retrieved sperm in Ireland; pregnancy and delivery are also described following transfer of cryopreserved/thawed embryos derived from such sperm. Finding no sperm from a semen analysis in a man without a vasectomy can be a devastating event, and substantially influences the scope of the reproductive endocrinology consultation. Successful treatment of non-obstructive azoospermia is possible without reliance on anonymous donor sperm.
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Affiliation(s)
- A P H Walsh
- The Sims Institute/Sims International Fertility Clinic, Rosemount Hall, Dundrum Road, Dundrum, Dublin 14, Ireland
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Jones BJ, Twomey PJ, Reynolds T. Average serum triglyceride concentration in relation to day of the week in Burton-on-Trent. Clin Mol Pathol 2009; 62:671-2. [DOI: 10.1136/jcp.2008.063933] [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: 11/03/2022]
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Yalamati P, Jones BJ, Twomey PJ. Appropriateness of the National Academy of Clinical Biochemistry recommendation of repeating HbA1c analysis for extreme results in clinical practice. Ann Clin Biochem 2009; 46:165-6. [DOI: 10.1258/acb.2008.008153] [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: 11/18/2022]
Abstract
Background The National Academy of Clinical Biochemistry (NACB) recommends that the presence of a variant or modified haemoglobin be considered when any HbA1c result is below the lower limit of the reference interval or ≥15%. In those instances where a variant haemoglobin is suspected, repeat measurement using an alternative method is the usual course of action. In the present study, we undertook to determine the impact of this guideline on our identification of variant and modified haemoglobins. Methods All requests for HbA1c estimation received over a 32-month period, and which gave a result of <4% or >15% were re-analysed by a different method and the results compared. Results Over the 32-month period, 94 samples with a HbA1c result of <4% or ≥15% were identified. Of these, 80 were re-analysed using a different method. No chromatographic abnormalities were seen and there were no significant differences between the results obtained using the two methods. Conclusions No variant or modified haemoglobins were identified in this study and this observation is likely to be representative of the ethnic makeup of our patient population. On the basis of this finding, we recommend that laboratories consider local factors when deciding whether to comply with the NACB guidelines.
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Affiliation(s)
- P Yalamati
- Department of Clinical Biochemistry, The Ipswich Hospital, Ipswich, Suffolk IP4 5PD, UK
| | - B J Jones
- Department of Clinical Biochemistry, The Ipswich Hospital, Ipswich, Suffolk IP4 5PD, UK
| | - P J Twomey
- Department of Clinical Biochemistry, The Ipswich Hospital, Ipswich, Suffolk IP4 5PD, UK
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Abstract
AIM Long-term lithium therapy is associated with hypercalcaemia in 10-60% of patients, but unlike creatinine and thyroid stimulating hormone (TSH), monitoring by general practitioners of serum calcium for patients on lithium is not a requirement of the Qualities and Outcomes Framework (QOF) of 2004. We aimed to assess requesting patterns for serum calcium in patients on long-term lithium therapy and subsequent diagnosis of hypercalcaemia. METHODS We identified 100 patients on long-term lithium therapy, as indicated by regular monitoring of lithium levels in our laboratory for at least 1 year. We determined how many of these patients had had serum calcium analysed, noting the assay date, concentration, source of request and clinical details stated. RESULTS Forty-three out of hundred patients had serum calcium analysed during the course of their treatment including 28 in the previous 15 months. Twenty-one patients had serum calcium analysed by their GP, including 12 in the previous 15 months. Hypercalcaemia was diagnosed in five patients (11.6%). CONCLUSION A significant proportion of patients in whom calcium was checked developed hypercalcaemia on lithium therapy. However, only 12% of the patients had serum calcium requested by their GP in the previous 15 months, which compares unfavourably with TSH and creatinine, for which monitoring approaches 100%. We recommend that serum calcium be checked every 15 months along with creatinine and TSH. This might be achieved by incorporating appropriate targets into the QOF, or by reflective or reflex adding-on of calcium to lithium specimens from patients who have not had calcium analysed in the previous 15 months.
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Affiliation(s)
- B J Jones
- Department of Clinical Biochemistry, The Ipswich Hospital, Ipswich, Suffolk, UK
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Twomey RJ, Jones BJ, Pledger DR. Introduction of automatically generated comment in clinical biochemistry: an audit of technical effectiveness. Br J Biomed Sci 2008; 65:102-3. [PMID: 19055114 DOI: 10.1080/09674845.2008.11732806] [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: 10/21/2022]
Affiliation(s)
- R J Twomey
- Department of Clinical Biochemistry, The Ipswich Hospital, Heath Road Ipswich, Suffolk IP4 5PD, UK.
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Jones BJ, Twomey PJ. Effect of a manually generated laboratory comment on requesting and performance of valproate assays. J Clin Pathol 2008; 61:1231. [PMID: 18955583 DOI: 10.1136/jcp.2008.060756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Abstract
The clinical use of unweighted nasogastric feeding tubes (n = 491) was compared with that of weighted nasogastric feeding tubes. No advantage was found in the use of the weighted tubes.
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Affiliation(s)
- P P Keohane
- Department of Gastroenterology and Nutrition, Central Middlesex Hospital, Acton Lane, London NW10 UK
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Keohane PP, Attrill H, Jones BJ, Brown I, Frost P, Silk DB. The roles of lactose and Clostridium difficile in the pathogenesis of enteral feeding associated diarrhoea. Clin Nutr 2008; 1:259-64. [PMID: 16829389 DOI: 10.1016/0261-5614(83)90003-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study investigated the influence of the disaccharide lactose on the incidence of clinically significant enteral feeding associated diarrhoea. In this double blind study both groups each of 25 patients were randomised to receive either a lactose containing diet Clinifeed 400 in 25 patients or a lactose free diet Ensure in 25 patients. Diarrhoea occurred with equal frequency in both treatment groups, even in those patients with symptomatic and biochemical evidence of impaired lactose handling. Although the onset of diarrhoea was significantly associated with antibiotic administration (p<0.01), Cl. difficile was not isolated from the stools of any patient with diarrhoea.
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Affiliation(s)
- P P Keohane
- Departments of Gastroenterology and Clinical Nutrition and Chemical Pathology, Central Middlesex Hospital, London NW10, U.K
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Wyatt RM, Jones BJ, Dale RG. Radiotherapy treatment delays and their influence on tumour control achieved by various fractionation schedules. Br J Radiol 2008; 81:549-63. [PMID: 18378526 DOI: 10.1259/bjr/94471640] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
There is often a considerable delay from initial tumour diagnosis to the start of radiotherapy treatment. This paper extends the calculations of a previous paper on the effects of delays before the initiation of radiotherapy treatment to include results from a variety of practical fractionation regimes for three different types of tumour: squamous cell carcinoma (head and neck), breast and prostate. The linear quadratic model of radiation effect, logarithmic tumour growth (coupled with delay times where relevant) and the Poisson model for tumour control probability (TCP) are used to calculate the change in TCP for delays between diagnosis and treatment. Within the limitations of radiobiological modelling, these data can be used to tentatively assess the interactions between delays, dose fractionation and TCP. The results show that delays in the start of radiotherapy treatment do have an adverse effect on tumour control for fast-growing tumours. For example, calculations predict a reduction in local tumour control of up to 1.5% per week's delay for head and neck cancers treated following surgery. In addition, there may be a variety of fractionation regimes that will yield very similar clinical results for each tumour type. It is shown theoretically that, for the tumour types considered here, it is possible to increase the dose per fraction and decrease the number of fractions while maintaining or increasing TCP relative to standard 2 Gy fractionation regimes, although there may be some advantage to using hyperfractionated regimes for head and neck cancers in order to reduce normal tissue effects.
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Affiliation(s)
- R M Wyatt
- Department of Radiotherapy Physics, Queen Elizabeth Hospital, Edgbaston, Birmingham B15 2TH, UK.
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Jones BJ, Twomey PJ. Relationship of the absolute difference between direct and indirect ion selective electrode measurement of serum sodium and the total protein concentration. J Clin Pathol 2008; 61:645-7. [DOI: 10.1136/jcp.2007.050872] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Jones BJ, Brooke G, Atkinson K, McTaggart SJ. Immunosuppression by placental indoleamine 2,3-dioxygenase: a role for mesenchymal stem cells. Placenta 2007; 28:1174-81. [PMID: 17714779 DOI: 10.1016/j.placenta.2007.07.001] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [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] [Received: 05/03/2007] [Revised: 06/21/2007] [Accepted: 07/05/2007] [Indexed: 02/07/2023]
Abstract
BACKGROUND/OBJECTIVES Mesenchymal stem cells (MSC) can be isolated from human placenta and have the potential to contribute to the immunosuppressive properties of placental tissue. The objectives of this study were to investigate the phenotype and differentiation characteristics of MSC derived from human placenta and evaluate the role of the tryptophan degrading enzyme, indoleamine 2,3 dioxygenase (IDO), in mediating their immunosuppressive affect. METHODS MSC obtained from placental tissue (pMSC) were characterised using flow cytometry and tested for multipotency by determining differentiation into all mesenchymal lineages. The immunosuppressive properties of pMSC were tested in allogeneic mixed lymphocyte reactions and IDO expression and activity were measured by semi-quantitative real-time PCR and HPLC respectively. RESULTS Multipotent stem cells were isolated from placenta and displayed chondrogenic, osteogenic and limited adipogenic differentiation. Cell surface antigen expression of pMSC was similar to bone marrow MSC (bMSC) with lack of the haematopoietic and common leukocyte markers (CD34, CD45), and expression of adhesion (CD29, CD166, CD44) and stem cell (CD 90, CD105, CD73) markers. Placental MSC were suppressive of allogeneic T-cell proliferation, an effect which was intensified following IDO induction by IFN-gamma. Replenishment of tryptophan or treatment with the IDO-blocker, 1-methyl-tryptophan (1-MT), attenuated the immunosuppressive action of pMSC. CONCLUSIONS These results suggest that placental tissue contains MSC, which are phenotypically and functionally similar to bMSC, and that IDO is a key mediator of their immunosuppressive effect. Further investigation is needed to determine if pMSC function effects pregnancy outcome.
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Affiliation(s)
- B J Jones
- Biotherapy Program, Mater Medical Research Institute, South Brisbane, QLD 4101, Australia
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Affiliation(s)
- B J Jones
- Northeastern Ohio Universities, Rootstown 44272-0095, USA
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Narain MA, Jones BJ. Images in focus uneventful endoscopic retrieval of a cannibalized aortic trouser graft. Endoscopy 2001; 33:390. [PMID: 11315911 DOI: 10.1055/s-2001-13688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Affiliation(s)
- M A Narain
- Dept. of Gastroenterology, Dudley Hospitals NHS Trust, UK.
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Jones BJ, Tidy D, Williams G. Cells for the measurement of dielectric permittivity and thermally stimulated discharge current. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0022-3735/9/8/026] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Mohammed I, Jones BJ. Antibiotic prophylaxis after percutaneous endoscopic gastrotomy insertion. Widespread routine use of prophylactic antibiotics might predispose to increased risk of resistant organisms. BMJ 2000; 320:870-1; author reply 871-2. [PMID: 10777316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Jones BJ, Arnold L, Xu G, Epstein LC. Differences in the preparation and practice of male and female physicians from combined baccalaureate--MD degree programs. J Am Med Womens Assoc (1972) 2000; 55:29-31. [PMID: 10680405] [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] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
OBJECTIVE To account for age and premedical education in determining whether or not men and women medical school graduates differ significantly in opinions of their medical school preparation, in professional activities, and in personal qualities and values. METHODS 727 graduates (1983-1987) of seven combined baccalaureate-MD degree programs were surveyed. Men's and women's responses were compared. RESULTS Women graduates were more likely than men to work less than full time and to report less preparation in the basic sciences, less scholarly activity, and more concern about psychosocial issues. CONCLUSION Differences between men and women graduates have persisted despite women's increased access to medical school. Even a special curriculum does not moderate these differences. We call on academic medicine to value humanism in health care, not just economics.
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Affiliation(s)
- B J Jones
- Northeastern Ohio Universities College of Medicine, USA
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Abstract
Seasonality of birth patterns is examined among a sample of 801 patients with schizophrenia separated into Type I and Type II schizophrenia. Findings indicate that both groups of patients were in utero during the winter but during different trimesters. Patients with Type I schizophrenia were more likely to be in utero during the third trimester. Patients with Type II schizophrenia were more likely to have been in the womb during the first trimester. Implications for fetal brain development are discussed.
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Affiliation(s)
- B J Gallagher
- Sociology Department, Villanova University, PA 19085, USA
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Selkirk JV, Scott C, Ho M, Burton MJ, Watson J, Gaster LM, Collin L, Jones BJ, Middlemiss DN, Price GW. SB-224289--a novel selective (human) 5-HT1B receptor antagonist with negative intrinsic activity. Br J Pharmacol 1998; 125:202-8. [PMID: 9776361 PMCID: PMC1565605 DOI: 10.1038/sj.bjp.0702059] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. Human 5-HT1B (h5-HT1B) and human 5-HT1D (h5-HT1D) receptors show remarkably similar pharmacology with few compounds discriminating the receptors. We report here on a novel compound, SB-224289 (1'-Methyl-5-[[2'-methyl-4'-(5-methyl- 1,2,4-oxadiazol-3-yl)biphenyl-4-yl]carbonyl]-2,3,6,7-tetrahydro spiro [furo [2,3-f]indole-3,4'-piperidine] oxalate), which has high affinity for h5-HT1B receptors (pK1=8.16+/-0.06) and displays over 75 fold selectivity for the h5-HT1B receptor over all other 5-HT receptors including the h5-HT1D receptor and all other receptors tested thus far. 2. Functional activity of SB-224289 was measured in a [15S]GTPgammaS binding assay on recombinant h5-HT1B and h5-HT1D receptors expressed in Chinese Hamster Ovary (CHO) cells. SB-224289 displayed negative intrinsic activity at both receptors with higher potency at h5-HT1B receptors. SB-224289 caused a rightward shift of agonist concentration response curves consistent with competitive antagonism and generated affinities comparable with those obtained from competition radioligand receptor binding studies. 3. SB-224289 potentiated [3H]5-HT release from electrically stimulated guinea-pig cerebral cortical slices to the same extent as as the non-selective 5-HT1 antagonist methiothepin. SB-224289 also fully reversed the inhibitory effect of exogenously superfused 5-HT on electrically stimulated release. 4. Using SB-224289 as a tool compound, we confirm that in guinea-pig cerebral cortex the terminal 5-HT autoreceptor is of the 5-HT1B subtype.
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Affiliation(s)
- J V Selkirk
- Department of Neurosciences, SmithKline Beecham Pharmaceuticals, Harlow, Essex
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Luttropp CA, Jackson JA, Jones BJ, Sohn MH, Lynch RE, Morton KA. Uptake of gallium-67 in transfected cells and tumors absent or enriched in the transferrin receptor. J Nucl Med 1998; 39:1405-11. [PMID: 9708518] [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: 02/08/2023] Open
Abstract
UNLABELLED Gallium-67 has been a controversial tumor-imaging agent in nuclear medicine for decades. This controversy centers on why tumors are variable in gallium-avidity, whether 67Ga uptake is a transferrin-independent or dependent process, and whether tumors and normal tissues differ in mechanism of uptake. If the factors that control uptake of 67Ga were understood better, then efforts to improve oncologic imaging with 67Ga by increasing the tumor activity, or by decreasing the background, may be warranted. METHODS Conventional systems for evaluating the mechanism and control of 67Ga uptake have significant limitations. We have endeavored to circumvent these by developing a pair of transfected cell lines. One cell line has no transferrin receptor. In the other, the human transferrin receptor has been restored by transfection and is over-expressed constitutively, without the necessity to manipulate factors such as cell growth or iron content. The uptake of 67Ga, both as a citrate salt and as a gallium-transferrin complex, was examined in these pairs of cells in vitro. The effect of calcium and of soluble (ionic) iron concentration on 67Ga uptake also was determined. Tumors were grown as explants of these cells in nude mice and comparisons of uptake of 67Ga by these tumors in vivo were made. RESULTS The in vivo uptake of 67Ga is significantly increased in tumors in which the transferrin receptor is overexpressed, compared to those without a functional transferrin receptor. However, a notable amount of accumulation of 67Ga also occurs, both in vitro and in vivo, by a transferrin-independent route. In vitro experiments demonstrate that the uptake of 67Ga by the transferrin-independent route can be enhanced further to levels that equal or exceed those achieved by the transferrin-dependent route by increasing the content of calcium or iron salts in the incubation medium. CONCLUSION Significant transferrin-independent uptake of 67Ga occurs both in vitro and in vivo. This uptake can be stimulated further in vitro, suggesting that in vivo enhancement might also be possible to enhance the utility of the radiometal for tumor imaging.
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Affiliation(s)
- C A Luttropp
- Imaging Service, VA Medical Center, Portland, Oregon 97207, USA
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Gaster LM, Blaney FE, Davies S, Duckworth DM, Ham P, Jenkins S, Jennings AJ, Joiner GF, King FD, Mulholland KR, Wyman PA, Hagan JJ, Hatcher J, Jones BJ, Middlemiss DN, Price GW, Riley G, Roberts C, Routledge C, Selkirk J, Slade PD. The selective 5-HT1B receptor inverse agonist 1'-methyl-5-[[2'-methyl-4'-(5-methyl-1,2, 4-oxadiazol-3-yl)biphenyl-4-yl]carbonyl]-2,3,6,7-tetrahydro- spiro[furo[2,3-f]indole-3,4'-piperidine] (SB-224289) potently blocks terminal 5-HT autoreceptor function both in vitro and in vivo. J Med Chem 1998; 41:1218-35. [PMID: 9548813 DOI: 10.1021/jm970457s] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.7] [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: 02/07/2023]
Abstract
5-HT1 receptors are members of the G-protein-coupled receptor superfamily and are negatively linked to adenylyl cyclase activity. The human 5-HT1B and 5-HT1D receptors (previously known as 5-HT1Dbeta and 5-HT1Dalpha, respectively), although encoded by two distinct genes, are structurally very similar. Pharmacologically, these two receptors have been differentiated using nonselective chemical tools such as ketanserin and ritanserin, but the absence of truly selective agents has meant that the precise function of the 5-HT1B and 5-HT1D receptors has not been defined. In this paper we describe how, using computational chemistry models as a guide, the nonselective 5-HT1B/5-HT1D receptor antagonist 4 was structurally modified to produce the selective 5-HT1B receptor inverse agonist 5, 1'-methyl-5-[[2'-methyl-4'-(5-methyl-1,2, 4-oxadiazol-3-yl)biphenyl-4-yl]carbonyl]-2,3,6, 7-tetrahydrospiro[furo[2,3-f]indole-3,4'-piperidine] (SB-224289). This compound is a potent antagonist of terminal 5-HT autoreceptor function both in vitro and in vivo.
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Affiliation(s)
- L M Gaster
- SmithKline Beecham Pharmaceuticals, Discovery Research, New Frontiers Science Park (North), Third Avenue, Harlow, Essex CM19 5AW, England
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Abstract
Nitric oxide (NO) is generated from L-arginine by different isoforms of the enzyme nitric oxide synthase (NOS) and is known to be involved in mediating several biological functions, some of which are associated with reproduction. In this study, we examined the ability of the prepubertal ovary to express the inducible (i), as well as the neuronal-type constitutive (c) form of NOS and also, investigated whether either isoform undergoes changes in the ovary during peripubertal development. Results indicate that both forms of NOS were expressed in the ovary and that the iNOS mRNA transcripts were expressed without being exogenously induced. When compared with juvenile levels, iNOS, but not cNOS, mRNA increased (p<0.01) during the early proestrous phase of development. By the late proestrous phase, the levels of iNOS mRNA declined markedly (p<0.001) and remained low throughout both the first estrous and diestrous phases. Western blot analysis revealed both iNOS and cNOS protein expression in each phase of puberty with only iNOS showing a significant change during the peripubertal period. Specifically, there was an initial increase in the expression of iNOS protein during the late proestrous phase (p<0.05) which was accompanied by preovulatory increases in serum estradiol (p<0.01) and LH (p<0.001). The iNOS protein levels then dramatically increased to peak on the morning of first estrus (p<0.001), an event associated with declining (p<0.05) serum levels of estradiol. These data demonstrate developmental changes in the expression of ovarian iNOS mRNA and protein both before and after first ovulation; hence, suggesting a role for NO in the ovary during pubertal maturation and furthermore, providing compelling evidence at the gene level supporting the hypothesis that the NO/NOS system plays a physiological role in ovarian function.
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Affiliation(s)
- V Srivastava
- Department of Veterinary Anatomy and Public Health, College of Veterinary Medicine, Texas A&M University, College Station 77843-4458, USA
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Price GW, Burton MJ, Collin LJ, Duckworth M, Gaster L, Göthert M, Jones BJ, Roberts C, Watson JM, Middlemiss DN. SB-216641 and BRL-15572--compounds to pharmacologically discriminate h5-HT1B and h5-HT1D receptors. Naunyn Schmiedebergs Arch Pharmacol 1997; 356:312-20. [PMID: 9303567 DOI: 10.1007/pl00005056] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Despite only modest homology between h5-HT1B and h5-HT1D receptor amino acid sequences, these receptors display a remarkably similar pharmacology. To date there are few compounds which discriminate between these receptor subtypes and those with some degree of selectivity, such as ketanserin, have greater affinity for other 5-HT receptor subtypes. We now report on two compounds, SB-216641 (N-[3-(2-dimethylamino) ethoxy-4-methoxyphenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)-(1,1'-biphenyl)-4-carboxamide) and BRL-15572 3-[4-(3-chlorophenyl) piperazin-1-yl]-1,1-diphenyl-2-propanol), which display high affinity and selectivity for h5-HT1B and h5-HT1D receptors, respectively. In receptor binding studies on human receptors expressed in CHO cells, SB-216641 has high affinity (pKi = 9.0) for h5-HT1B receptors and has 25-fold lower affinity at h5-HT1D receptors. In contrast, BRL-15572 has 60-fold higher affinity for h5-HT1D (pKi = 7.9) than 5-HT1B receptors. Similar affinities for these compounds were determined on native tissue 5-HT1B receptors in guinea-pig striatum. Functional activities of SB-216641 and BRL-15572 were measured in a [35S]GTPgammaS binding assay and in a cAMP accumulation assay on recombinant h5-HT1B and h5-HT1D receptors. Both compounds were partial agonists in these high receptor expression systems, with potencies and selectivities which correlated with their receptor binding affinities. In the cAMP accumulation assay, results from pK(B) measurements on the compounds again correlated with receptor binding affinities (SB-216641, pK(B) = 9.3 and 7.3; BRL-15572, pK(B) = <6 and 7.1, for h5-HT1B and h5-HT1D receptors respectively). These compounds will be useful pharmacological agents to characterise 5-HT1B and 5-HT1D receptor mediated responses.
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Affiliation(s)
- G W Price
- Department of Neuroscience, SmithKline Beecham Pharmaceuticals, Harlow, Essex, UK
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Abstract
1. We have studied the effects of the purportedly selective 5-HT1A receptor antagonist (+)-WAY 100135 on electrically stimulated 5-hydroxytryptamine (5-HT) efflux in the ventrolateral geniculate nucleus (vLGN), and its affinity at human 5-HT1B and 5-HT1D receptors stably expressed in Chinese hamster ovary (CHO) cells. 2. On short 'pseudo single pulse' stimulations (20 pulses at 100 Hz, 190 ms train duration), (+)-WAY 100135 (1.0 microM) decreased 5-HT efflux in the vLGN to 68 +/- 8% of pre-drug values (P < 0.01). This decrease could be blocked by the 5-HT1D/1B receptor antagonist GR 127935 (50 nM). Conversely, when long stimulations (20 pulses at 20 Hz, 950 ms train) were used, (+)-WAY 100135 had no effect on 5-HT efflux (84 +/- 8% of pre-drug values) although both methiothepin (200 nM) and GR 127935 (50 nM) caused significant increases (to 175 +/- 18 and 130 +/- 10% of pre-drug values, respectively). 3. Paroxetine (100 nM), the selective 5-HT reuptake inhibitor, increased stimulated 5-HT efflux and reuptake half-life (to 145 +/- 18% and 649 +/- 121%, respectively) on pseudo single pulse stimulations. When (+)-WAY 100135 was added in combination with the uptake blocker, the effect of paroxetine on stimulated 5-HT efflux was potentiated to 282 +/- 48% (P < 0.01) without further effect on the 5-HT reuptake half-life. 4. The affinity and intrinsic activity of (+)-WAY 100135 were determined at recombinant human 5-HT1B and 5-HT1D receptors expressed in CHO cells, by use of radioligand binding and [35S]-GTP gamma S binding (+)-WAY 100135 was a partial agonist at human 5-HT1B and 5-HT1D receptors with moderately high affinity for 5-HT1D receptors (pEC50 = 7.61). 5. In conclusion, (+)-WAY 100135 was found to be not a selective 5-HT1A autoreceptor antagonist but may act as a partial agonist at the 5-HT1B/1D receptor, displaying agonist or antagonist properties depending on the stimulation protocol used and the resultant 5-HT 'tone' at the receptor.
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Affiliation(s)
- C Davidson
- Anaesthetics Unit (Neurotransmission Laboratory), St Bartholomew's and the Royal London School of Medicine and Dentistry, Royal London Hospital
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Roberts C, Price GW, Jones BJ. The role of 5-HT(1B/1D) receptors in the modulation of 5-hydroxytryptamine levels in the frontal cortex of the conscious guinea pig. Eur J Pharmacol 1997; 326:23-30. [PMID: 9178651 DOI: 10.1016/s0014-2999(97)00156-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [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: 02/04/2023]
Abstract
The role of 5-HT(1B/1D) receptors in modulating extracellular 5-hydroxytryptamine (5-HT) levels in the guinea pig was investigated with the non-selective 5-HT(1B/1D) receptor inverse agonist, methiothepin, and the selective 5-HT(1B/1D) receptor partial agonists, GR 127935 (n-[4-methoxy-3-(4-methyl-1-piperizinyl)phenyl]-2'-methyl-4'-(5-me thyl-1,2,4-oxadiazole-3-yl)[1,1'-biphenyl]-4-carboxamide) and GR 125743 (n-[4-methoxy-3-(4-methyl-1-piperizinyl)phenyl]-3-methyl-4-(4-pyri dinyl)benzamide). Extracellular 5-HT levels were measured using the technique of brain microdialysis, in the frontal cortex of the freely moving guinea-pig. Extracellular 5-HT was tetrodotoxin sensitive and calcium dependent, and increased when perfused with a high concentration of K+. In addition, extracellular 5-HT levels were lowered by the 5-HT(1B/1D) receptor agonist, sumatriptan, and the 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetralin, while perfusion of the selective serotonin re-uptake inhibitor, paroxetine, increased 5-HT in a concentration-dependent manner. Perfusion of methiothepin, GR 127935 and GR 125743 into the frontal cortex caused significant but transient increases of extracellular 5-HT. However, systemic administration of methiothepin, GR 127935 and GR 125743, at 0.3 mg/kg i.p., produced significant decreases in extracellular 5-HT, to minima of 27 +/- 3%, 31 +/- 12% and 27 +/- 13% of basal, respectively. The increase of extracellular 5-HT, following 5-HT(1B/1D) receptor inverse and partial agonist perfusion into the frontal cortex, was probably a consequence of attenuation of an endogenous 5-HT tone at terminal 5-HT autoreceptors. The unexpected decrease in 5-HT levels following systemic administration may be a result of additional attenuation of endogenous 5-HT tone at cell body autoreceptors in the raphe. Such an increase in local 5-HT levels could then stimulate 5-HT1A receptors to inhibit cell firing and hence decrease 5-HT levels in the terminal regions. This was confirmed when co-administration of the 5-HT1A receptor antagonist, WAY 100635, significantly attenuated the GR 127935 decrease in 5-HT.
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Affiliation(s)
- C Roberts
- SmithKline Beecham Pharmaceuticals, Harlow, Essex, UK
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46
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Abstract
Although ceramide signaling pathways have been implicated in cell death, neither their role in hepatocellular death nor the cellular mechanisms mediating ceramide-induced cell death are known. The mitochondrial membrane permeability transition (MMPT) has been proposed as a common final pathway in cell death. Thus the aims of our study were to determine if ceramides cause hepatocellular death by necrosis and not apoptosis as confirmed by morphology and the absence of internucleosomal DNA cleavage. Ceramide-mediated hepatocyte necrosis was acyl chain-length, concentration, and time-dependent. Ceramides induced cell necrosis was associated with adenosine triphosphate (ATP) depletion and mitochondrial depolarization suggesting that ceramides caused mitochondrial dysfunction. In isolated mitochondria, ceramides induced the cyclosporine A-sensitive MMPT in an acyl chain-length and concentration dependent manner. Ceramide toxicity was specific as the less potent dihydro form did not induce cell necrosis, significant ATP depletion, mitochondrial depolarization nor the MMPT. In conclusion, ceramide induced cell death is acyl-chain length dependent and mediated by the MMPT. These data show for the first time that ceramide acts as a mediator of hepatocyte necrosis by causing mitochondrial failure.
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Affiliation(s)
- A S Arora
- Center for Basic Research in Digestive Diseases, Mayo Clinic and Foundation, Rochester, MN 55905, USA
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Roberts C, Price GW, Gaster L, Jones BJ, Middlemiss DN, Routledge C. Importance of h5-HT1B receptor selectivity for 5-HT terminal autoreceptor activity: an in vivo microdialysis study in the freely-moving guinea-pig. Neuropharmacology 1997; 36:549-57. [PMID: 9225280 DOI: 10.1016/s0028-3908(97)00026-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [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: 02/04/2023]
Abstract
The importance of h5-HT1B receptor selectivity for 5-HT terminal autoreceptor activity was investigated with the selective h5-HT1B receptor ligands SB 219085, SB 220272, SB 224289 and SB 216641. The studies employed measurement of compound affinity and efficacy in vitro and the measurement of extracellular 5-HT in the frontal cortex of the freely-moving guinea-pig using in vivo microdialysis. All compounds had high affinity and selectivity for the h5-HT1B receptor, with SB 224289 the most selective for h5-HT1B over h5-HT1D receptors. Compounds exhibited a range of efficacies at both receptors: SB 224289 and SB 219085 were inverse agonists, SB 220272 was an antagonist and SB 216641 was a partial agonist. SB 220272, SB 216641 and SB 224289 had no effect on extracellular 5-HT following systemic administration, however, SB 219085 produced a significant increase. The SB 219085-induced increase in extracellular 5-HT was attributed to the compounds non-specific releasing properties as it was also demonstrated to increase basal release of [3H]5-HT from pre-loaded guinea-pig cortical slices. The lack of effect of the above h5-HT1B receptor selective compounds and the decrease in extracellular 5-HT elicited by the non-selective compounds GR 127935, GR125743 and methiothepin suggest that antagonism of 5-HT1D receptors may mediate this decrease in 5-HT levels. It is plausible that blockade of 5-HT1D receptors increases 5-HT levels in the raphe, this activates 5-HTtA receptors which results in an overall decrease in terminal 5-HT release. Definitive proof now awaits elucidation of the action of a selective 5-HT1D receptor antagonist.
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Affiliation(s)
- C Roberts
- Department of Psychiatry Research, SmithKline Beecham Pharmaceuticals, Harlow, Essex, U.K. @inet
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Abstract
Chitin deacetylase (EC 3.5.1.41), which hydrolyses the N-acetamido groups of N-acetyl-D-glucosamine residues in chitin, has been demonstrated in crude extracts from sporulating Saccharomyces cerevisiae. Two S. cerevisiae open reading frames (ORFs), identified by the Yeast Genome Project, have protein sequence homology to a chitin deacetylase from Mucor rouxii. Northern blot hybridizations show each ORF was transcribed in diploid cells after transfer to sporulation medium and prior to formation of asci. Each ORF was cloned in a vector under transcriptional control of the GAL 1, 10 promoter and introduced back into haploid strains of S. cerevisiae. Chitin deacetylase activity was detected by in vitro assays from vegetative cells grown in galactose. Chemical analysis of these cells also demonstrated the synthesis of chitosam in vivo. Both recombinant chitin deacetylases showed similar qualitative and quantitative activities toward chitooligosaccharides in vitro. A diploid strain deleted to both ORFs, when sporulated, did not show deacetylase activity. The mutant spores were hypersensitive to lytic enzymes (Glusulase or Zymolyase).
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Affiliation(s)
- C Mishra
- Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139, USA
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Abstract
A simple, reliable, automated genetic analysis instrument has been designed and prototyped. The system uses novel fluidic technology, coupling thermal cycling, reaction purification, in-line loading, and capillary electrophoresis in a single instrument. Samples in the loop of an injection valve are amplified inside a rapid air thermal cycler. A liquid chromatographic separation eliminates contaminants and excess salt. The sample is loaded in an efficient, continuous, flow-through manner onto a polymer-filled separation capillary. Detection by laser-induced fluorescence produces signal-to-noise ratios of 1000:1 or greater. Refilling of the polymer-filled capillary is automatic; during the run, the system is reconditioned for injection of another sample. Since all components and connections are fluidic, automation is natural and simple. The instrument is reliable and fast, performing PCR reaction cycling, purification and analysis, all in 20 min. Reproducibility (CV) of retention times is 2% (n = 129) and of peak areas 9% (n = 34). Bubbles and particulates are eliminated by the chromatography column. Adaptation of the instrument prototype for separation of DNA-sequencing reactions is described; cycle sequencing and electrophoresis of a single lane are complete in 90 min. Implications and challenges for development of fully automated fluidic instruments for genomic sequencing are discussed.
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Affiliation(s)
- H Swerdlow
- Department of Human Genetics, University of Utah, Salt Lake City 84112, USA
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Niaz SK, Sandrasegaran K, Renny FH, Jones BJ. Postinfective diarrhoea and bile acid malabsorption. J R Coll Physicians Lond 1997; 31:53-6. [PMID: 9044199 PMCID: PMC5420841] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Postinfective irritable bowel syndrome with diarrhoea and idiopathic bile acid malabsorption remains an enigma. We examined the records of 84 patients whose 75SeHCAT scans were indicative of bile acid malabsorption (< 15% one week retention). Identifiable causes of bile acid malabsorption were: previous ileal surgery (7), Crohn's disease (22), radiation enteritis (13), vagotomy, gastrectomy or cholecystectomy (10) and miscellaneous (3). Sixteen of 29 patients with apparently idiopathic bile acid malabsorption gave a clear history of acute gastroenteritis before the onset of chronic diarrhoea lasting from 0.25-18 years until their positive 75SeHCAT scan. Only four cases of campylobacter, and one each of shigella and salmonella were documented. Extensive investigation failed to detect other possible pathologies. In response to bile acid sequestrants, mean stool frequency fell from 7.2 per day to 2.1 per day (p < 0.001). We have observed that postinfective chronic diarrhoea is associated with chronic bile acid malabsorption, which can be successfully treated with bile acid sequestrants such as cholestyramine.
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