1
|
Haron S, Kilmister EJ, Davis PF, Stylli SS, Mantamadiotis T, Kaye AH, Hall SR, Tan ST, Wickremesekera AC. The renin-angiotensin system in central nervous system tumors and degenerative diseases. Front Biosci (Landmark Ed) 2021; 26:628-642. [PMID: 34590472 DOI: 10.52586/4972] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 07/12/2021] [Revised: 08/10/2021] [Accepted: 08/16/2021] [Indexed: 11/09/2022]
Abstract
Despite their differences, central nervous system (CNS) tumors and degenerative diseases share important molecular mechanisms underlying their pathologies, due to their common anatomy. Here we review the role of the renin-angiotensin system (RAS) in CNS tumors and degenerative diseases, to highlight common molecular features and examine the potential merits in repurposing drugs that inhibit the RAS, its bypass loops, and converging signaling pathways. The RAS consists of key components, including angiotensinogen, (pro)renin receptor (PRR), angiotensin-converting enzyme 1 (ACE1), angiotensin-converting enzyme 2 (ACE2), angiotensin I (ATI), angiotensin II (ATII), ATII receptor 1 (AT1R), ATII receptor 2 (AT2R) and the Mas receptor (MasR). The RAS is integral to systemic and cellular pathways that regulate blood pressure and body fluid equilibrium and cellular homeostasis. The main effector of the RAS is ATII which exerts its effect by binding to AT1R and AT2R through two competitive arms: an ACE1/ATII/AT1R axis, which is involved in regulating oxidative stress and neuroinflammation pathways, and an ATII/AT2R and/or ATII/ACE2/Ang(1-7)/MasR axis that potentiates neuroprotection pathways. Alterations of these axes are associated with cellular dysfunction linked to CNS diseases. The generation of ATII is also influenced by proteases that constitute bypass loops of the RAS. These bypass loops include cathepsins B, D and G and chymase and aminopeptidases. The RAS is also influenced by converging pathways such as the Wnt/β-catenin pathway which sits upstream of the RAS via PRR, a key component of the RAS. We also discuss the co-expression of components of the RAS and markers of pluripotency, such as OCT4 and SOX2, in Parkinson's disease and glioblastoma, and their potential influences on transduction pathways involving the Wnt/β-catenin, MAPK/ERK, PI3K/AKT and vacuolar (H+) adenosine triphosphatase (V-ATPase) signaling cascades. Further research investigating modulation of the ACE1/ATII/AT1R and ACE2/Ang(1-7)/MasR axes with RAS inhibitors may lead to novel treatment of CNS tumors and degenerative diseases. The aim of this review article is to discuss and highlight experimental and epidemiological evidence for the role of the RAS, its bypass loops and convergent signaling pathways in the pathogenesis of CNS tumors and degenerative diseases, to direct research that may lead to the development of novel therapy.
Collapse
Affiliation(s)
- Simon Haron
- Department of Neurosurgery, Wellington Regional Hospital, 6242 Wellington, New Zealand
| | | | - Paul F Davis
- Gillies McIndoe Research Institute, 6242 Wellington, New Zealand
| | - Stanley S Stylli
- Department of Surgery, The Royal Melbourne Hospital, The University of Melbourne, Parkville, 3050 Victoria, Australia.,Department of Neurosurgery, The Royal Melbourne Hospital, Parkville, 3050 Victoria, Australia
| | - Theo Mantamadiotis
- Department of Surgery, The Royal Melbourne Hospital, The University of Melbourne, Parkville, 3050 Victoria, Australia
| | - Andrew H Kaye
- Department of Neurosurgery, Hadassah Hebrew University Medical Centre, 91120 Jerusalem, Israel
| | - Sean R Hall
- Gillies McIndoe Research Institute, 6242 Wellington, New Zealand
| | - Swee T Tan
- Gillies McIndoe Research Institute, 6242 Wellington, New Zealand.,Department of Surgery, The Royal Melbourne Hospital, The University of Melbourne, Parkville, 3050 Victoria, Australia.,Wellington Regional Plastic, Maxillofacial & Burns Unit, Hutt Hospital, 5040 Lower Hutt, New Zealand
| | - Agadha C Wickremesekera
- Department of Neurosurgery, Wellington Regional Hospital, 6242 Wellington, New Zealand.,Gillies McIndoe Research Institute, 6242 Wellington, New Zealand.,Department of Surgery, The Royal Melbourne Hospital, The University of Melbourne, Parkville, 3050 Victoria, Australia
| |
Collapse
|
2
|
Cookman J, Hamilton V, Hall SR, Bangert U. Non-classical crystallisation pathway directly observed for a pharmaceutical crystal via liquid phase electron microscopy. Sci Rep 2020; 10:19156. [PMID: 33154480 PMCID: PMC7644682 DOI: 10.1038/s41598-020-75937-2] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/22/2020] [Indexed: 12/18/2022] Open
Abstract
Non-classical crystallisation (NCC) pathways are widely accepted, however there is conflicting evidence regarding the intermediate stages of crystallisation, how they manifest and further develop into crystals. Evidence from direct observations is especially lacking for small organic molecules, as distinguishing these low-electron dense entities from their similar liquid-phase surroundings presents signal-to-noise ratio and contrast challenges. Here, Liquid Phase Electron Microscopy (LPEM) captures the intermediate pre-crystalline stages of a small organic molecule, flufenamic acid (FFA), a common pharmaceutical. High temporospatial imaging of FFA in its native environment, an organic solvent, suggests that in this system a Pre-Nucleation Cluster (PNC) pathway is followed by features exhibiting two-step nucleation. This work adds to the growing body of evidence that suggests nucleation pathways are likely an amalgamation of multiple existing non-classical theories and highlights the need for the direct evidence presented by in situ techniques such as LPEM.
Collapse
Affiliation(s)
- J Cookman
- Physics Department & Bernal Institute, University of Limerick, Castletroy, Co. Limerick, Ireland
| | - V Hamilton
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - S R Hall
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
| | - U Bangert
- Physics Department & Bernal Institute, University of Limerick, Castletroy, Co. Limerick, Ireland.
| |
Collapse
|
3
|
Keller MD, Neppl C, Irmak Y, Hall SR, Schmid RA, Langer R, Berezowska S. Adverse prognostic value of PD-L1 expression in primary resected pulmonary squamous cell carcinomas and paired mediastinal lymph node metastases. Mod Pathol 2018; 31:101-110. [PMID: 28884747 DOI: 10.1038/modpathol.2017.111] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 07/19/2017] [Accepted: 07/19/2017] [Indexed: 02/07/2023]
Abstract
Immunohistochemical assessment of programmed cell death (PD)-ligand 1 (PD-L1) expression in lung cancer in the context of therapeutically targeting the PD1/PD-L1 axis is still controversially discussed. This includes the comparability of antibody clones, prognostic value, and discrepancies between primary tumors and metastases. We assessed tumoral PD-L1 expression using clones E1L3N and SP142 in 372 primary resected pulmonary squamous cell carcinomas, including 40 paired N2 lymph node metastases, in relation with clinico-pathological parameters. PD-L1 expression was negative (<1%) in 163/372 (44%, E1L3N) or 231/370 patients (62%, SP142). Positivity of 1-<50% was observed in 135 (36%, E1L3N) or 92 patients (25%, SP142) and ≥50% in 74 (20%, E1L3N) or 47 patients (13%, SP142). PD-L1 staining correlated significantly between both antibodies (r=0.781; P<0.001). Scores correlated significantly between full-slide sections (N=40) and tissue microarrays, and between primaries and N2 metastases (P<0.001 all). CD8+ tumor infiltrating lymphocyte counts positively correlated with PD-L1 expression (P<0.001). PD-L1 ≥50% showed the best prognostic discrimination using the split-sample validation method. It was associated with shorter disease-specific survival in the observation group (E1L3N: P=0.035, SP142: P=0.002) and validation group (E1L3N: P=0.024, SP142: P=0.101) and shorter time to recurrence (observation group: E1L3N: P=0.056, SP142: P<0.001; validation group: E1L3N: P=0.036, SP142: P=0.247). Multivariate analysis showed that PD-L1 expression ≥50% determined by clone E1L3N was an independent prognostic factor in the observation group regarding disease-specific survival (HR=2.768; 95% CI=1.149-6.666; P=0.023) and time to recurrence (HR=2.164; 95% CI=1.056-4.436; P=0.035) and in the validation group (disease-specific survival: HR=1.978; 95% CI=0.928-4.214; P=0.077 and time to recurrence: HR=1.571; 95% CI=0.838-2.944; P=0.159). High PD-L1 expression was associated with adverse prognosis in pulmonary squamous cell carcinoma. Clone E1L3N was more sensitive than SP142 and superior regarding prognostication. PD-L1 expression correlated significantly between primary tumor and N2 metastases, rendering mediastinal lymph node metastases adequate for immunohistochemical assessment.
Collapse
Affiliation(s)
- Manuel D Keller
- Institute of Pathology, University of Bern, Bern, Switzerland
| | - Christina Neppl
- Institute of Pathology, University of Bern, Bern, Switzerland
| | - Yasin Irmak
- Institute of Pathology, University of Bern, Bern, Switzerland
| | - Sean R Hall
- Division of General Thoracic Surgery, Inselspital University Hospital Bern, Bern, Switzerland.,Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Ralph A Schmid
- Division of General Thoracic Surgery, Inselspital University Hospital Bern, Bern, Switzerland.,Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Rupert Langer
- Institute of Pathology, University of Bern, Bern, Switzerland
| | | |
Collapse
|
4
|
Chen Z, Eadie AL, Hall SR, Ballantyne L, Ademidun D, Tse MY, Pang SC, Melo LG, Ward CA, Brunt KR. Assessment of hypoxia and TNF-alpha response by a vector with HRE and NF-kappaB response elements. Front Biosci (Schol Ed) 2017; 9:46-54. [PMID: 27814573 DOI: 10.2741/s471] [Citation(s) in RCA: 2] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Hypoxia and inflammatory cytokine activation (H&I) are common processes in many acute and chronic diseases. Thus, a single vector that responds to both hypoxia and inflammatory cytokines, such as TNF-alpha, is useful for assesing the severity of such diseases. Adaptation to hypoxia is regulated primarily by hypoxia inducible transcription factor (HIF alpha) nuclear proteins that engage genes containing a hypoxia response element (HRE). Inflammation activates a multitude of cytokines, including TNF-alpha, that invariably modulate activation of the nuclear factor kappa B (NF-kB) transcription factor. We constructed a vector that encompassed both a hypoxia response element (HRE), and a NF-kappaB responsive element. We show that this vector was functionally responsive to both hypoxia and TNF-alpha, in vitro and in vivo. Thus, this vector might be suitable for the detection and assessment of hypoxia or TNF-alpha.
Collapse
Affiliation(s)
- Zhilin Chen
- Department of Physiology, Queen's University, Kingston, Ontario, Canada
| | - Ashley L Eadie
- Department of Pharmacology, Dalhousie Medicine New Brunswick, PO Box 5050, 100 Tucker Park Road, Saint John, NB, Canada E2L 4L5
| | - Sean R Hall
- Department of Physiology, Queen's University, Kingston, Ontario, Canada
| | - Laurel Ballantyne
- Department of Physiology, Queen's University, Kingston, Ontario, Canada
| | - David Ademidun
- Department of Physiology, Queen's University, Kingston, Ontario, Canada
| | - M Yat Tse
- Department of Anatomy and Cell Biology Queen's University, Kingston, Ontario, Canada
| | - Stephen C Pang
- Department of Anatomy and Cell Biology Queen's University, Kingston, Ontario, Canada
| | - Luis G Melo
- Department of Physiology, Queen's University, Kingston, Ontario, Canada
| | | | - Keith R Brunt
- Department of Pharmacology, Dalhousie Medicine New Brunswick, PO Box 5050, 100 Tucker Park Road, Saint John, NB, Canada E2L 4L5,
| |
Collapse
|
5
|
Pan LL, Atlas EL, Salawitch RJ, Honomichl SB, Bresch JF, Randel WJ, Apel EC, Hornbrook RS, Weinheimer AJ, Anderson DC, Andrews SJ, Baidar S, Beaton SP, Campos TL, Carpenter LJ, Chen D, Dix B, Donets V, Hall SR, Hanisco TF, Homeyer CR, Huey LG, Jensen JB, Kaser L, Kinnison DE, Koenig TK, Lamarque JF, Liu C, Luo J, Luo ZJ, Montzka DD, Nicely JM, Pierce RB, Riemer DD, Robinson T, Romashkin P, Saiz-Lopez A, Schauffler S, Shieh O, Stell MH, Ullmann K, Vaughan G, Volkamer R, Wolfe G. The Convective Transport of Active Species in the Tropics (CONTRAST) Experiment. Bull Am Meteorol Soc 2017; 98:106-128. [PMID: 29636590 PMCID: PMC5889942 DOI: 10.1175/bams-d-14-00272.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The Convective Transport of Active Species in the Tropics (CONTRAST) experiment was conducted from Guam (13.5° N, 144.8° E) during January-February 2014. Using the NSF/NCAR Gulfstream V research aircraft, the experiment investigated the photochemical environment over the tropical western Pacific (TWP) warm pool, a region of massive deep convection and the major pathway for air to enter the stratosphere during Northern Hemisphere (NH) winter. The new observations provide a wealth of information for quantifying the influence of convection on the vertical distributions of active species. The airborne in situ measurements up to 15 km altitude fill a significant gap by characterizing the abundance and altitude variation of a wide suite of trace gases. These measurements, together with observations of dynamical and microphysical parameters, provide significant new data for constraining and evaluating global chemistry climate models. Measurements include precursor and product gas species of reactive halogen compounds that impact ozone in the upper troposphere/lower stratosphere. High accuracy, in-situ measurements of ozone obtained during CONTRAST quantify ozone concentration profiles in the UT, where previous observations from balloon-borne ozonesondes were often near or below the limit of detection. CONTRAST was one of the three coordinated experiments to observe the TWP during January-February 2014. Together, CONTRAST, ATTREX and CAST, using complementary capabilities of the three aircraft platforms as well as ground-based instrumentation, provide a comprehensive quantification of the regional distribution and vertical structure of natural and pollutant trace gases in the TWP during NH winter, from the oceanic boundary to the lower stratosphere.
Collapse
Affiliation(s)
- L L Pan
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | | | | | - S B Honomichl
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - J F Bresch
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - W J Randel
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - E C Apel
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - R S Hornbrook
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - A J Weinheimer
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - D C Anderson
- University of Maryland, College Park, Maryland, USA
| | | | - S Baidar
- University of Colorado Boulder, Boulder, Colorado, USA
| | - S P Beaton
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - T L Campos
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | | | - D Chen
- Georgia Institute of Technology, Atlanta, Georgia, USA
| | - B Dix
- University of Colorado Boulder, Boulder, Colorado, USA
| | - V Donets
- University of Miami, Florida, USA
| | - S R Hall
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - T F Hanisco
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - C R Homeyer
- University of Oklahoma, Norman, Oklahoma, USA
| | - L G Huey
- Georgia Institute of Technology, Atlanta, Georgia, USA
| | - J B Jensen
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - L Kaser
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - D E Kinnison
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - T K Koenig
- University of Colorado Boulder, Boulder, Colorado, USA
| | - J-F Lamarque
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - C Liu
- Texas A&M University at Corpus Christi, Texas, USA
| | - J Luo
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Z J Luo
- City College of New York, New York, New York, USA
| | - D D Montzka
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - J M Nicely
- University of Maryland, College Park, Maryland, USA
| | - R B Pierce
- NOAA Satellite and Information Service (NESDIS) Center for Satellite Applications and Research (STAR), Madison Wisconsin, USA
| | | | - T Robinson
- University of Hawaii at Mānoa, Hawaii, USA
| | - P Romashkin
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - A Saiz-Lopez
- Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain
| | - S Schauffler
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - O Shieh
- University of Hawaii at Mānoa, Hawaii, USA
| | - M H Stell
- National Center for Atmospheric Research, Boulder, Colorado, USA
- Metropolitan State University, Denver, Colorado, USA
| | - K Ullmann
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - G Vaughan
- University of Manchester, Manchester, UK
| | - R Volkamer
- University of Colorado Boulder, Boulder, Colorado, USA
| | - G Wolfe
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- University of Maryland Baltimore County, Baltimore, Maryland, USA
| |
Collapse
|
6
|
Keil A, Hall SR, Körner M, Herrmann M, Schmid RA, Frese S. Suppression of lupus nephritis and skin lesions in MRL/lpr mice by administration of the topoisomerase I inhibitor irinotecan. Arthritis Res Ther 2016; 18:243. [PMID: 27770825 PMCID: PMC5075215 DOI: 10.1186/s13075-016-1144-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [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: 04/26/2016] [Accepted: 10/03/2016] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Since the precise mechanism for the pathogenesis of systemic lupus erythematosus (SLE) is unknown, no targeted therapies in addition to immunosuppression are available so far. We recently demonstrated that administration of the topoisomerase I (topo I) inhibitor irinotecan at extremely low concentrations reversed established lupus nephritis in NZB/NZW mice. While profound immunosuppression was absent, we proposed changes in DNA relaxation and anti-double-stranded (ds)DNA antibody binding as the underlying mechanism. To exclude that these effects were restricted to NZB/NZW mice, irinotecan was used in a genetically different strain of lupus-prone mice. METHODS MRL/lpr mice were treated with high- and low-dose irinotecan beginning at 8 weeks of age. Treatment was repeated every fourth week. In vitro, DNA was relaxed by recombinant topo I, and altered anti-dsDNA antibody binding was measured by enzyme-linked immunosorbent assay. RESULTS Administration of both high- and low-dose irinotecan prevented proteinuria and prolonged survival in MRL/lpr mice. Moreover, both concentrations of irinotecan significantly improved histopathology of the skin at 18 weeks of age. While only high-dose irinotecan diminished the numbers of plasmablasts and double-negative T cells, no changes in IgG-secreting cells or anti-dsDNA IgG were observed. In vitro, relaxation of DNA by topo I increased the binding of anti-dsDNA IgG but not the binding of anti-dsDNA IgM derived from the plasma of MRL/lpr mice. CONCLUSION The beneficial effects of topo I inhibition in a second, genetically different strain of lupus-prone mice strongly implicate irinotecan as a new therapeutic option for human SLE.
Collapse
Affiliation(s)
- Andreas Keil
- Department of Clinical Research and Division of General Thoracic Surgery, University Hospital Bern, Murtenstrasse 50, PO Box 44, , CH-3010, Bern, Switzerland
| | - Sean R Hall
- Department of Clinical Research and Division of General Thoracic Surgery, University Hospital Bern, Murtenstrasse 50, PO Box 44, , CH-3010, Bern, Switzerland
| | - Meike Körner
- Institute of Pathology, Länggasse, Bern, Switzerland
| | - Martin Herrmann
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Ralph A Schmid
- Department of Clinical Research and Division of General Thoracic Surgery, University Hospital Bern, Murtenstrasse 50, PO Box 44, , CH-3010, Bern, Switzerland
| | - Steffen Frese
- Department of Clinical Research and Division of General Thoracic Surgery, University Hospital Bern, Murtenstrasse 50, PO Box 44, , CH-3010, Bern, Switzerland.
| |
Collapse
|
7
|
Cáceres CE, Davis G, Duple S, Hall SR, Koss A, Lee P, Rapti Z. Complex Daphnia interactions with parasites and competitors. Math Biosci 2014; 258:148-61. [PMID: 25445737 DOI: 10.1016/j.mbs.2014.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 11/08/2013] [Revised: 10/01/2014] [Accepted: 10/07/2014] [Indexed: 10/24/2022]
Abstract
Species interactions can strongly influence the size and dynamics of epidemics in populations of focal hosts. The "dilution effect" provides a particularly interesting type of interaction from a biological standpoint. Diluters - other host species which resist infection but remove environmentally-distributed propagules of parasites (spores) - should reduce disease prevalence in focal hosts. However, diluters and focal hosts may compete for shared resources. This combination of positive (dilution) and negative (competition) effects could greatly complicate, even undermine, the benefits of dilution and diluter species from the perspective of the focal host. Motivated by an example from the plankton (i.e., zooplankton hosts, a fungal parasite, and algal resources), we study a model of dilution and competition. Our model reveals a suite of five results: • A diluter that is a superior competitor wipes out the host, regardless of parasitism. Although expected, this outcome is an ever-present danger in strategies that might use diluters to control disease. • If the diluter is an inferior competitor, it can reduce disease prevalence, despite the competition, as parameterized in our model. However, competition may also reduce density of susceptible hosts to levels below that seen in focal host-parasite systems alone. • As they decrease disease prevalence, diluters destabilize dynamics of the focal host and their resources. Thus, diluters undermine the stabilizing effects of disease. • The four species combination can generate very complex dynamics, including period-doubling bifurcations and torus (Neimark-Sacker) bifurcations. • At lower resource carrying capacity, the diluter’s dilution of spores is 'helpful' to the focal host, i.e., dilution can elevate host density by reducing disease. But, as the resource carrying capacity increases further, the equilibrium density of the diluter increases while the density of the focal host decreases, despite competition. Namely, the negative effects of competition start to outweigh the positive effects of dilution from the perspective of equilibrium density of the focal host.
Collapse
Affiliation(s)
- C E Cáceres
- School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - G Davis
- Department of Mathematics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - S Duple
- School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - S R Hall
- Department of Biology, Indiana University, Bloomington, IN 47405, United States
| | - A Koss
- Department of Mathematics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - P Lee
- School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Z Rapti
- Department of Mathematics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
| |
Collapse
|
8
|
Affiliation(s)
- S R Hall
- School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
| | | | | | | |
Collapse
|
9
|
Auld SKJR, Penczykowski RM, Housley Ochs J, Grippi DC, Hall SR, Duffy MA. Variation in costs of parasite resistance among natural host populations. J Evol Biol 2013; 26:2479-86. [PMID: 24118613 DOI: 10.1111/jeb.12243] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [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: 06/19/2013] [Revised: 08/09/2013] [Accepted: 08/09/2013] [Indexed: 11/30/2022]
Abstract
Organisms that can resist parasitic infection often have lower fitness in the absence of parasites. These costs of resistance can mediate host evolution during parasite epidemics. For example, large epidemics will select for increased host resistance. In contrast, small epidemics (or no disease) can select for increased host susceptibility when costly resistance allows more susceptible hosts to outcompete their resistant counterparts. Despite their importance for evolution in host populations, costs of resistance (which are also known as resistance trade-offs) have mainly been examined in laboratory-based host-parasite systems. Very few examples come from field-collected hosts. Furthermore, little is known about how resistance trade-offs vary across natural populations. We addressed these gaps using the freshwater crustacean Daphnia dentifera and its natural yeast parasite, Metschnikowia bicuspidata. We found a cost of resistance in two of the five populations we studied - those with the most genetic variation in resistance and the smallest epidemics in the previous year. However, yeast epidemics in the current year did not alter slopes of these trade-offs before and after epidemics. In contrast, the no-cost populations showed little variation in resistance, possibly because large yeast epidemics eroded that variation in the previous year. Consequently, our results demonstrate variation in costs of resistance in wild host populations. This variation has important implications for host evolution during epidemics in nature.
Collapse
Affiliation(s)
- S K J R Auld
- School of Natural Sciences, University of Stirling, Stirling, UK; School of Biology, Georgia Institute of Technology, Atlanta, GA, USA
| | | | | | | | | | | |
Collapse
|
10
|
Kajstura J, Rota M, Hall SR, Hosoda T, D'Amario D, Sanada F, Zheng H, Ogórek B, Rondon-Clavo C, Ferreira-Martins J, Matsuda A, Arranto C, Goichberg P, Giordano G, Haley KJ, Bardelli S, Rayatzadeh H, Liu X, Quaini F, Liao R, Leri A, Perrella MA, Loscalzo J, Anversa P. Evidence for human lung stem cells. N Engl J Med 2011; 364:1795-806. [PMID: 21561345 PMCID: PMC3197695 DOI: 10.1056/nejmoa1101324] [Citation(s) in RCA: 316] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Although progenitor cells have been described in distinct anatomical regions of the lung, description of resident stem cells has remained elusive. METHODS Surgical lung-tissue specimens were studied in situ to identify and characterize human lung stem cells. We defined their phenotype and functional properties in vitro and in vivo. RESULTS Human lungs contain undifferentiated human lung stem cells nested in niches in the distal airways. These cells are self-renewing, clonogenic, and multipotent in vitro. After injection into damaged mouse lung in vivo, human lung stem cells form human bronchioles, alveoli, and pulmonary vessels integrated structurally and functionally with the damaged organ. The formation of a chimeric lung was confirmed by detection of human transcripts for epithelial and vascular genes. In addition, the self-renewal and long-term proliferation of human lung stem cells was shown in serial-transplantation assays. CONCLUSIONS Human lungs contain identifiable stem cells. In animal models, these cells participate in tissue homeostasis and regeneration. They have the undemonstrated potential to promote tissue restoration in patients with lung disease. (Funded by the National Institutes of Health.).
Collapse
Affiliation(s)
- Jan Kajstura
- Department of Anesthesia, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Kinkaid H, Yarr J, Hall SR, McCusker G, McStay M, Briggs GM. Can touch imprint cytology replace fine needle aspiration within current clinical practice? Breast Cancer Res 2010. [PMCID: PMC2978831 DOI: 10.1186/bcr2667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
12
|
Abstract
Haem oxygenase (HO)-1 is a cytoprotective enzyme that plays a critical role in defending the body against oxidant-induced injury during inflammatory processes. HO catalydes the degradation of haem to carbon monoxide (CO), biliverdin and ferrous iron. Biliverdin is converted to bilirubin, a potent endogenous antioxidant. CO has a number of biological functions, including anti-inflammatory properties. In various models of disease, HO-1 is known to play a critical role by ameliorating the pathological consequences of injury. In many of these models, the beneficial effects of HO-1 and its products of haem catabolism are by suppressing an inflammatory response. However, when investigating diseases due to microbial infections, inhibition of the inflammatory response could disrupt the ability of the immune system to eradicate an invading pathogen. Thus, questions remain regarding the role of HO-1 in microbial host defence. This microreview will address our present understanding of HO-1 and its functional significance in a variety of microbial infections.
Collapse
Affiliation(s)
- Su Wol Chung
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan, Korea.
| | | | | |
Collapse
|
13
|
Liu X, Ramjiganesh T, Chen YH, Chung SW, Hall SR, Schissel SL, Padera RF, Liao R, Ackerman KG, Kajstura J, Leri A, Anversa P, Yet SF, Layne MD, Perrella MA. Disruption of striated preferentially expressed gene locus leads to dilated cardiomyopathy in mice. Circulation 2008; 119:261-8. [PMID: 19118250 DOI: 10.1161/circulationaha.108.799536] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND The striated preferentially expressed gene (Speg) generates 4 different isoforms through alternative promoter use and tissue-specific splicing. Depending on the cell type, Speg isoforms may serve as markers of striated or smooth muscle differentiation. METHODS AND RESULTS To elucidate function of Speg gene isoforms, we disrupted the Speg gene locus in mice by replacing common exons 8, 9, and 10 with a lacZ gene. beta-Galactosidase activity was detected in cardiomyocytes of the developing heart starting at day 11.5 days post coitum (dpc). beta-Galactosidase activity in other cell types, including vascular smooth muscle cells, did not begin until 18.5 dpc. In the developing heart, protein expression of only Spegalpha and Spegbeta isoforms was present in cardiomyocytes. Homozygous Speg mutant hearts began to enlarge by 16.5 dpc, and by 18.5 dpc, they demonstrated dilation of right and left atria and ventricles. These cardiac abnormalities in the absence of Speg were associated with a cellular hypertrophic response, myofibril degeneration, and a marked decrease in cardiac function. Moreover, Speg mutant mice exhibited significant neonatal mortality, with increased death occurring by 2 days after birth. CONCLUSIONS These findings demonstrate that mutation of the Speg locus leads to cardiac dysfunction and a phenotype consistent with a dilated cardiomyopathy.
Collapse
Affiliation(s)
- Xiaoli Liu
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Takamiya R, Hung CC, Hall SR, Fukunaga K, Nagaishi T, Maeno T, Owen C, Macias AA, Fredenburgh LE, Ishizaka A, Blumberg RS, Baron RM, Perrella MA. High-mobility group box 1 contributes to lethality of endotoxemia in heme oxygenase-1-deficient mice. Am J Respir Cell Mol Biol 2008; 41:129-35. [PMID: 19097991 DOI: 10.1165/rcmb.2008-0331oc] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
High-mobility group box 1 (HMGB1) is a nuclear protein that has been found to be a critical mediator of lethality in endotoxemia and sepsis. During the systemic inflammatory response, circulating levels of HMGB1 are increased, but in a delayed fashion compared with early inflammatory mediators. To counteract the inflammatory response of endotoxemia, a secondary anti-inflammatory response ensues in an attempt to prevent inflammation-induced tissue injury. One such cytoprotective gene that is induced during endotoxemia is heme oxygenase (HO)-1. HO-1, and its products of heme metabolism, possess anti-inflammatory and antioxidant properties to counter the damaging effects of endotoxemia. In the present study, we wanted to determine whether tissue and circulating levels of HMGB1 are increased further in the absence of HO-1 during endotoxemia, and whether this increase may contribute to the pathobiology of endotoxemia. Lung inflammation, HMGB1 protein levels, and expression of HMGB1 in inflammatory cells were increased in HO-1(-/-) mice compared with HO-1+/+ mice. After the administration of LPS, tissue levels of HMGB1 were not increased further in HO-1(-/-) mice; however, circulating levels of HMGB1 were higher when compared with HO-1+/+ mice. HO-1(-/-) mice treated with a carbon monoxide-releasing molecule or biliverdin showed a reduction in plasma HMGB1, which was associated with a marked improvement in survival. HO-1(-/-) mice given HMGB1-neutralizing antibody showed improvement in survival compared with control antibody. These data suggest that exaggerated circulating levels of HMGB1 contribute to endotoxin-induced mortality in the absence of HO-1.
Collapse
Affiliation(s)
- Rina Takamiya
- Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, 75 Francis St., Boston, MA 02115, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Kinobe RT, Simpson JA, Brunt KR, Hall SR, Ballantyne LL, Ogunyankin KO, Ward C, Melo LG. Heme Oxygenase‐1 Attenuates Isoproterenol‐induced Cardiac Hypertrophy in vivo. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.970.40] [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: 11/11/2022]
|
16
|
Jiang W, Hall SR, Moos MPW, Cao RY, Ishii S, Ogunyankin KO, Melo LG, Funk CD. Endothelial cysteinyl leukotriene 2 receptor expression mediates myocardial ischemia-reperfusion injury. Am J Pathol 2008; 172:592-602. [PMID: 18276782 DOI: 10.2353/ajpath.2008.070834] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cysteinyl leukotrienes (CysLTs) have been implicated as inflammatory mediators of cardiovascular disease. Three distinct CysLT receptor subtypes transduce the actions of CysLTs but the role of the endothelial CysLT2 receptor (CysLT2R) in cardiac function is unknown. Here, we investigated the role of CysLT2R in myocardial ischemia-reperfusion (I/R) injury using transgenic (tg) mice overexpressing human CysLT2R in vascular endothelium and nontransgenic (ntg) littermates. Infarction size in tg mice increased 114% compared with ntg mice 48 hours after I/R; this increase was blocked by the CysLT receptor antagonist BAY-u9773. Injection of 125 I-albumin into the systemic circulation revealed significantly enhanced extravasation of the label in tg mice, indicating increased leakage of the coronary endothelium, combined with increased incidence of hemorrhage and cardiomyocyte apoptosis. Expression of proinflammatory genes such as Egr-1, VCAM-1, and ICAM was significantly increased in tg mice relative to ntg controls. Echocardiographic assessment 2 weeks after I/R revealed decreased anterior wall thickness in tg mice. Furthermore, the postreperfusion time constant tau of isovolumic relaxation was significantly increased in tg animals, indicating diastolic dysfunction. These results reveal that endothelium-targeted overexpression of CysLT2R aggravates myocardial I/R injury by increasing endothelial permeability and exacerbating inflammatory gene expression, leading to accelerated left ventricular remodeling, induction of peri-infarct zone cellular apoptosis, and impaired cardiac performance.
Collapse
Affiliation(s)
- Wei Jiang
- Department of Physiology, 433 Botterell Hall, Stuart St., Queen's University, Kingston, ON K7L 3N6 Canada
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
Parasites are integral parts of most ecosystems, yet attention has only recently focused on how community structure and abiotic factors impact host-parasite interactions. In lakes, both factors are influenced by habitat morphology. To investigate the role of habitat structure in mediating parasitism in the plankton, we quantified timing and prevalence of a common microparasite (Metschnikowia bicuspidata) in its host, Daphnia dentifera, in 18 lakes that vary in basin size and shape. Over three years, we found substantial spatial and temporal variation in the severity of epidemics. Although infection rates reached as high as 50% in some lakes, they did not occur in most lakes in most years. Host density, often considered to be a key determinant of disease spread, did not explain a significant amount of variation in the occurrence of epidemics. Furthermore, host resistance does not fully explain this parasite's distribution, since we easily infected hosts in the laboratory. Rather, basin shape predicted epidemics well; epidemics occurred only in lakes with steep-sided basins. In these lakes, the magnitude of epidemics varied with year. We suggest that biological (predation) and physical (turbulence) effects of basin shape interact with annual weather patterns to determine the regional distribution of this parasite.
Collapse
Affiliation(s)
- C E Cáceres
- School of Integrative Biology, University of Illinois at Urbana-Champaign, 61801, USA.
| | | | | | | | | | | |
Collapse
|
18
|
Chen Z, Hall SR, Ward CA, Melo LG. Construction of a Bicistronic Lentiviral Vector for Efficient Transduction and Expression of Multiple Therapeutic Genes in Adult Stem Cells. FASEB J 2007. [DOI: 10.1096/fasebj.21.6.a825-a] [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: 11/11/2022]
Affiliation(s)
- Zhilin Chen
- PhysiologyQueen’s University18 Stuart Street, Botterell HallKingston0, K7L 3N6Canada
| | - Sean R. Hall
- PhysiologyQueen’s University18 Stuart Street, Botterell HallKingston0, K7L 3N6Canada
| | - Christopher A. Ward
- PhysiologyQueen’s University18 Stuart Street, Botterell HallKingston0, K7L 3N6Canada
| | - Luis G. Melo
- PhysiologyQueen’s University18 Stuart Street, Botterell HallKingston0, K7L 3N6Canada
| |
Collapse
|
19
|
Abstract
In addition to macromolecular interactions that provide co-stimulation during antigen-presenting cell (APC) and CD4+ T-cell conjugation, covalent chemical events between specialized ligands have been implicated in T-cell co-stimulation. These take the form of transient Schiff base formation between carbonyls and amines expressed on APC and T-cell surfaces. Small Schiff base-forming molecules, such as tucaresol, can substitute for the physiological donor of carbonyl groups and provide co-stimulation to T cells, thereby functioning as orally active immunopotentiatory drugs. The Schiff base co-stimulatory pathway in T cells has been partially characterized in terms of changes in Na+ and K+ transport, and activation of the mitogen activated protein kinase (MAPK) ERK2. In the present study, the effects of Schiff base co-stimulation by tucaresol on the T-cell receptor (TCR)-dependent pathway leading to Ca2+ release were investigated. Schiff base co-stimulation by tucaresol was found to prime for enhanced TCR-dependent phospholipase C-gamma phosphorylation, inositol 1,4,5-triphosphate production, and Ca2+ mobilization that correlated with functional enhancement of interleukin-2 production in primary T cells. The effects on Ca2+ occurred comparably in Jurkat and primary CD4+ T cells responding to anti-CD3 monoclonal antibody. Enhancement of the Ca2+ response required a 10-min priming period and was prevented by prior covalent ligation of cell-surface free amino groups by sulpho-N-hydroxy succinimido-biotin; clofilium-mediated inhibition of tucaresol-induced changes in intracellular K+; and selective inhibition of the MAPK pathway. The data are consistent with a priming mechanism in which late co-stimulation-triggered events exert a positive influence on early TCR-triggered events. In additional studies of murine T cells expressing trans-gene TCRs, tucaresol was likewise shown to prime for enhanced Ca2+ mobilization in response to physiological TCR-engagement by MHC-peptide complexes.
Collapse
Affiliation(s)
- S R Hall
- Department of Immunology and Virology, GlaxoSmithKline Research and Development, Medicines Research Centre, Stevenage, UK.
| | | |
Collapse
|
20
|
Milne B, Hall SR, Sullivan ME, Loomis C. The release of spinal prostaglandin E2 and the effect of nitric oxide synthetase inhibition during strychnine-induced allodynia. Anesth Analg 2001; 93:728-33. [PMID: 11524348 DOI: 10.1097/00000539-200109000-00037] [Citation(s) in RCA: 12] [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: 11/26/2022]
Abstract
The removal of spinal glycinergic inhibition by intrathecal strychnine produces an allodynia-like state in rodents. Our objective was to measure spinal prostaglandin E2 (PGE2) release during strychnine-allodynia and examine the effects of Nomega-nitro-L-arginine (L-NOARG), an inhibitor of nitric oxide synthetase. Under halothane, rats were fitted with intrathecal and spinal microdialysis catheters, and microelectrodes implanted into the locus coeruleus for measurement of catechol oxidation current (CAOC) using voltammetry. Animals were then administered urethane and treated as follows: 1) baseline control 10 min, intrathecal strychnine (40 microg) 10 min, 10 min of hair deflection, and 2) 10-min control followed by intrathecal strychnine (40 microg) with hair deflection for 60 min. Spinal dialysate samples were collected for PGE2 levels determined by using immunoassay. In separate experiments, the effect of intrathecal strychnine (40 microg) followed by hair deflection was studied in rats pretreated with intrathecal l-NOARG (50 nmol). After intrathecal strychnine, hair deflection significantly increased spinal PGE2 release (619% +/- 143%), locus coeruleus CAOC (181% +/- 6%), and mean arterial pressure (123% +/- 2%) P < 0.05. Pretreatment with intrathecal l-NOARG significantly inhibited strychnine-allodynia. In this model, hair deflection evokes spinal PGE2 release, locus coeruleus activation, and an increase in mean arterial pressure. L-NOARG pretreatment attenuated the locus coeruleus CAOC, a biochemical index of strychnine-allodynia, suggesting a mediator role of nitric oxide. A mediator role of nitric oxide is also implicated, helping to explain the pathophysiology of this allodynic pain.
Collapse
Affiliation(s)
- B Milne
- Department of Anesthesiology, Pharmacology, and Toxicology, Queen's University, Kingston, Ontario, Canada
| | | | | | | |
Collapse
|
21
|
Abstract
The STAR File (J. Chem. Inf Comput. Sci. 1994, 34, 505-508) is used widely in structural chemistry for exchanging numerical and text information with scientific journals and databases. These exchanges are increasingly dependent on data dictionaries to facilitate automatic data validation and checking. Definitions in data dictionaries are constructed using attribute descriptors, and this paper describes a method attribute for specifying the relationships between data items as an executable script written in a new relational expression language called dREL. The addition of this attribute improves the precision and the semantic content of dictionaries by providing relational representations of data, as well as facilitating the direct evaluation of derivable data items. The capacity to evaluate derivative data directly from the combination of primitive data and dictionary expressions is expected to change future archival approaches. The design concepts of the relational expression language dREL parser, which are applicable to any discipline, are described.
Collapse
Affiliation(s)
- N Spadaccini
- Department of Computer Science and Crystallography Centre, University of Western Australia, Nedlands, Perth, Australia.
| | | | | |
Collapse
|
22
|
Abstract
Previous studies have shown that activation of N-methyl-D-aspartate (NMDA) receptors and formation of nitric oxide (NO) contributes to the hyperactivity of locus coeruleus (LC) noradrenergic neurons and behavioural symptoms seen during opioid withdrawal. However, the role of soluble guanylyl cyclase (sGC), the 'physiological' target of NO, in this phenomenon is unclear. In this study, the effect of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a highly selective sGC inhibitor, on the naloxone-precipitated morphine withdrawal was examined using differential normal pulse voltammetry (DNPV) to measure LC activity, in vivo microdialysis to measure glutamate/aspartate release response, and behavioural assessment to evaluate withdrawal symptoms. In halothane-anaesthetized rats, acute intracerebroventricular (i.c.v.) morphine (10 microg) reduced the catecholamine oxidation current (CA.OC) (54.5+/-4.9% of baseline). Naloxone (2 mg/kg, i.v.) reversed this action of morphine and produced a rebound increase in CA.OC (136.1+/-6.0% of baseline), representing acute morphine withdrawal. Administration of ODQ (200 nmol, i.c.v.) blocked this response without affecting acute morphine action. In animals chronically treated with morphine (15 microg/microl/h, i.c.v., 5 days), naloxone significantly increased both the CA.OC signal (270.0+/-19.6% of baseline) and the release of L-glu (193+/-30.4%) and L-asp (221.5+/-28.4%) above baseline. These responses were attenuated in animals pretreated with ODQ. In unanaesthetized chronic morphine dependent rats, ODQ treatment suppressed the signs of withdrawal precipitated by naloxone (10 mg/kg). Taken together, the results of this study suggest that sGC plays an intermediary role in the genesis of LC neuronal hyperactivity and behavioural signs of morphine withdrawal.
Collapse
Affiliation(s)
- M E Sullivan
- Department of Pharmacology and Toxicology and Anesthesiology, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | | | | | | |
Collapse
|
23
|
Abstract
Peripheral CD4+ T cells can be divided into two different functional populations based on the expression of distinct isoforms of the surface molecule CD45. We have investigated the differences in the proximal signaling induced by anti-CD3 monoclonal antibody in purified populations of "naive" CD45RA+ and "memory" CD45RO+ human CD4+ T cells. Expression of cell surface CD3, CD4 and CD28 was comparable between RA+ and RO+ cells. However, TCR-directed stimulation in the form of anti-CD3 produced markedly different patterns of intracellular signaling. Greater inositol triphosphate generation occurred in naive cells and the rise in intracellular free calcium was also substantially greater in naive than in memory cells. Cells with the naive phenotype were considerably more active in TCR-dependent tyrosine phosphorylation, both at an overall level and specifically in terms of TCR-zeta and ZAP-70 phosphorylation. Despite these differences in phosphorylation, the amounts of TCR-zeta, ZAP-70 and Ick were equivalent between the two subsets. These findings suggest that the TCR-dependent signaling is differentially regulated in naive and memory CD4+ T cells. This may be due to differences in the way that the two isoforms of the CD45 phosphatase regulate the activity of proximal kinases in the TCR signaling pathway, and could be an important means by which the unique functions of differentiated T cell populations are maintained.
Collapse
Affiliation(s)
- S R Hall
- Immunology Unit, Glaxo Wellcome Research and Development, Medicines Research Centre, Stevenage, GB.
| | | | | | | |
Collapse
|
24
|
Hall SR, Wang L, Milne B, Loomis C. Activation of the rostral ventrolateral medulla in an acute anesthetized rodent strychnine model of allodynia. Anesth Analg 1999; 88:1125-30. [PMID: 10320182 DOI: 10.1097/00000539-199905000-00030] [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] [Indexed: 11/26/2022]
Abstract
UNLABELLED After the administration of intrathecal strychnine, allodynia is manifested as activation of supraspinal sites involved in pain processing and enhancement of cardiovascular responses evoked by normally innocuous stimuli. The objective of this study was to investigate the effect of strychnine-induced allodynia on adrenergic neuronal activity in the C1 area of the rostral ventrolateral medulla (RVLM), a major site involved in cardiovascular regulation. The effect of intrathecal strychnine (40 microg) or saline followed by repeated hair deflection to caudal lumbar dermatomes in the urethane-anesthetized rat was assessed by measuring voltammetric changes in the RVLM catechol oxidation current (CA x OC), mean arterial pressure (MAP), and heart rate (HR). After the administration of intrathecal strychnine, hair deflection evoked a significant and sustained increase in the RVLM CA x OC and MAP (peak 146.4%+/-5.6% and 159%+/-18.4% of baseline, respectively; P < 0.05). There was a nonsignificant increase in HR (peak 128%+/-8.2%). In the absence of hair deflection, there was no demonstrable change. Intrathecal saline-treated rats failed to demonstrate changes in RVLM CA x OC, MAP, or HR. In the present study, we demonstrated that, after the administration of intrathecal strychnine, innocuous hair deflection evokes temporally related neuronal activation in the rat RVLM and an increase in MAP. This suggests that the RVLM mediates, at least in part, the cardiovascular responses during strychnine allodynia. IMPLICATIONS Neural injury-associated pain, as manifested by allodynia, is resistant to conventional treatment. In a rat model of allodynia, we demonstrated activation of the brain region involved in sympathetic control. Innovative therapies that target this region may be successful in managing this debilitating condition.
Collapse
Affiliation(s)
- S R Hall
- Department of Anaesthesia, Queens University, Kingston, Ontario, Canada
| | | | | | | |
Collapse
|
25
|
Hall SR, Wang L, Milne B, Loomis C. Activation of the Rostral Ventrolateral Medulla in an Acute Anesthetized Rodent Strychnine Model of Allodynia. Anesth Analg 1999. [DOI: 10.1213/00000539-199905000-00030] [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: 11/05/2022]
|
26
|
Hall SR, Milne B, Loomis C. Spinal action of ketorolac, S(+)- and R(-)-ibuprofen on non-noxious activation of the catechol oxidation in the rat locus coeruleus: evidence for a central role of prostaglandins in the strychnine model of allodynia. Anesthesiology 1999; 90:165-73. [PMID: 9915325 DOI: 10.1097/00000542-199901000-00022] [Citation(s) in RCA: 7] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Blockade of spinal glycine receptors with intrathecal strychnine produces an allodynia-like state in the anesthetized rat. Innocuous hair deflection in the presence of intrathecal strychnine induces a nociceptive-like activation of catechol oxidation in the locus coeruleus and enhances cardiovascular responses. Because prostaglandins play a central role in augmenting pain, this study evaluated the effect of intrathecal nonsteroidal antiinflammatory drugs in strychnine-induced allodynia. METHODS In urethane-anesthetized rats, changes in catechol oxidation in the locus coeruleus, measured using in vivo voltammetry, and cardiovascular parameters evoked by hair deflection of caudal dermatomes were determined after strychnine (40 microg) or saline were administered intrathecally. Subsequently, the effects of 30 microg ketorolac, 10 microg S(+)-ibuprofen, and 10 microg R(-)-ibuprofen administered intrathecally were evaluated. RESULTS After strychnine was administered intrathecally, hair deflection evoked an increase in the locus coeruleus catechol oxidation (peak, 149.7+/-7.2% of baseline) and mean arterial blood pressure (peak, 127.5+/-3.8% of baseline). These responses were not observed after saline was administered intrathecally. All hair deflection-evoked, strychnine-dependent peak responses were attenuated significantly with intrathecally administered ketorolac and S(+)-ibuprofen but not with R(-)-ibuprofen. CONCLUSIONS Locus coeruleus catechol oxidation is a sensitive biochemical index of strychnine-induced allodynia and is correlated temporally with the cardiovascular responses evoked by hair deflection during spinal glycinergic inhibition. The ability of intrathecally administered ketorolac and S(+)-ibuprofen, but not R(-)-ibuprofen, to suppress the locus coeruleus catechol oxidation and cardiovascular peak responses evoked during strychnine-induced allodynia provide evidence that central prostaglandins play an important role in the abnormal sensory processing of strychnine-induced allodynia.
Collapse
Affiliation(s)
- S R Hall
- Department of Anaesthesia, Queen's University, Kingston, Ontario, Canada
| | | | | |
Collapse
|
27
|
Hall SR. Implant diagnostics utilizing computed tomography imaging. J Okla Dent Assoc 1998; 85:19-24. [PMID: 9526233] [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: 02/06/2023]
|
28
|
Abstract
The greater Dayton area has begun building the nation's first advanced technology community network for sharing patient medical information among independent hospitals. Its success in doing so has resulted from the surmounting of numerous business and technical barriers. Others planning to develop such networks can learn from the Dayton experience.
Collapse
Affiliation(s)
- T W Ferratt
- Department of MIS & Decision Sciences, School of Business Administration, University of Dayton, OH, USA
| | | | | | | |
Collapse
|
29
|
Hall SR. The community-centered board model of managed care for people with developmental disabilities. Health Soc Work 1996; 21:225-229. [PMID: 8854127 DOI: 10.1093/hsw/21.3.225] [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] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- S R Hall
- Resource Exchange, Colorado Springs, CO 80909, USA
| |
Collapse
|
30
|
Hall SR, Campbell LE, Meek DW. Phosphorylation of p53 at the casein kinase II site selectively regulates p53-dependent transcriptional repression but not transactivation. Nucleic Acids Res 1996; 24:1119-26. [PMID: 8604347 PMCID: PMC145737 DOI: 10.1093/nar/24.6.1119] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The p53 tumour suppressor protein is a potent transcription factor which plays a central role in the defence of cells against DNA damage and the propagation of malignant clones. We have previously shown that phosphorylation of serine 386 in mouse p53 by the growth- associated protein kinase, casein kinase II (CKII), plays an important role in the ability of p53 to block the proliferation of drug-resistant colonies. In this paper we show that blocking phosphorylation of serine 386 through an alanine substitution, or placing a constitutive negative charge at this position in the form of aspartate, had no significant influence on p53-dependent transcriptional activation of a promoter containing 13 copies of a p53 consensus binding sequence, or of the p21WAF1 promoter which is a natural target for p53. In contrast, the alanine mutant showed a weak reduction in the ability of p53 to repress expression from the c-fos promoter, which is a target for p53-dependent repression in vivo. Strikingly, when the repression of the SV40 early promoter was examined, a reduction in the repression capacity of up to 5-fold was observed. Moreover, repression of the SV40 promoter could be partially restored by aspartic acid substitution at the phosphorylation site. These data indicate that phosphorylation at a specific C-terminal site can selectively regulate p53-dependent repression, but not transactivation.
Collapse
Affiliation(s)
- S R Hall
- Biomedical Research Centre, University of Dundee, United Kingdom
| | | | | |
Collapse
|
31
|
Abstract
The aim of the present study was to provide preliminary information on the acute and chronic effects of infectious mononucleosis (IM) on memory, attention, psychomotor performance and mood. These issues were examined by comparing individuals with acute IM, those who had the initial illness some months before, and matched healthy controls. Objective measures of memory, attention, motor skills and visual functions were obtained, as were subjective reports of mood. The results showed selective effects of acute IM on performance and mood, with the profile of impairments being very similar to those observed in previous studies of influenza. Different impairments were observed in subjects who had the primary illness several months before, and the effects observed in this group were similar to those observed in recent studies of chronic fatigue syndrome patients. Both acute and chronic IM subjects reported similar levels of symptoms and psychopathology, with both groups having greater scores than the controls. However, the performance impairments did not reflect symptoms or psychopathology. One may conclude that the study of IM will provide important data on both the acute and longer lasting effects of viral infections on the brain and behaviour.
Collapse
Affiliation(s)
- S R Hall
- School of Psychology, University of Birmingham, UK
| | | |
Collapse
|
32
|
Michael LH, Entman ML, Hartley CJ, Youker KA, Zhu J, Hall SR, Hawkins HK, Berens K, Ballantyne CM. Myocardial ischemia and reperfusion: a murine model. Am J Physiol 1995; 269:H2147-54. [PMID: 8594926 DOI: 10.1152/ajpheart.1995.269.6.h2147] [Citation(s) in RCA: 189] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Myocardial ischemia followed by reperfusion promotes a complex series of inflammatory reactions as noted in a variety of large animal studies. With development of genetically altered mice, there is intense interest in developing murine models to study mechanisms operative in cardiovascular disease. We developed a mouse model to study coronary artery occlusion and reperfusion effects and the method required to perform these studies both acutely and chronically. In mice, we applied a left anterior descending coronary artery occlusion either permanently or for 30 or 60 min followed by reperfusion allowing flow through the previously occluded coronary artery bed. Reperfusion was documented visually as well as by using Doppler ultrasound and histopathological techniques. The area at risk (AAR) and infarct size (IS) were assessed by EVans blue dye and triphenyltetrazolium chloride staining with computerized planimetry using an image analysis software program. The infarct as percentage of AAR and IS as percentage of the left ventricle in 13 mice with permanent occlusion was 68.6 +/- 4.4 and 28.0 +/- 2.8%, respectively. Reperfusion after occlusions of 60 and 30 min resulted in a significant decrease in IS as a percentage of the AAR compared with permanent occlusion. Histological examination of the ischemic and reperfused myocardium shows infiltration of leukocytes into the ischemic region as well as contraction bands classically associated with reperfusion. This new model allows assessment of AAR, IS, cardiac function, and pathophysiology in the mouse. With the current technology to develop genetically altered mice for overexpression or targeted mutations of various genes, this model is used to understand the complex pathophysiology of ischemia and reperfusion injury.
Collapse
Affiliation(s)
- L H Michael
- Sections of Cardiovascular Sciences, Department of Medicine and Pediatrics, Methodist Hospital, Houston, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Rhodes J, Chen H, Hall SR, Beesley JE, Jenkins DC, Collins P, Zheng B. Therapeutic potentiation of the immune system by costimulatory Schiff-base-forming drugs. Nature 1995; 377:71-5. [PMID: 7659167 DOI: 10.1038/377071a0] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.9] [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: 01/26/2023]
Abstract
Immune responses are orchestrated by CD4 T lymphocytes, which receive a cognitive signal when clonally distributed receptors are occupied by major histocompatibility complex (MHC) class II-bound peptides on antigen-presenting cells (APCs). The APCs provide costimulatory signals, through macromolecules such as CD80, that regulate outcomes in terms of T-cell activation or anergy. We have studied essential complementary chemical events in the form of Schiff base formation between carbonyls and amines that are constitutively expressed on presenting cell and T-cell surfaces and provide a new target for manipulation of immune responses. Here we show that small Schiff base-forming molecules can substitute for the physiological donor of carbonyl groups and provide a costimulatory signal to CD4 Th-cells through a mechanism that activates clofilium-sensitive K+ and Na+ transport. One such molecule, tucaresol, enhances CD4 Th-cell responses, selectively favouring a Th1-type profile of cytokine production. In vivo tucaresol potently enhances CD4 Th-cell priming and CD8 cytotoxic T-cell priming to viral antigens, and has substantial therapeutic activity in murine models of disease.
Collapse
Affiliation(s)
- J Rhodes
- Molecular Immunology Group, Wellcome Research Laboratories, Beckenham, Kent, UK
| | | | | | | | | | | | | |
Collapse
|
34
|
Beesley JE, Hall SR, Page MJ, Affleck K. Early elemental and ionic changes in cultured cells after stimulation with epidermal growth factor. Scanning Microsc 1995; 9:231-238. [PMID: 8553019] [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: 05/22/2023]
Abstract
Stimulation of A431 cells (a human vulval epidermal cell line) with 50 ng/ml of epidermal growth factor (EGF) in the presence of 1.7 mM extracellular calcium produced a sharp and sustained rise in intracellular ionic Ca2+, increased elemental Na, decreased K and a rise in Ca. In the absence of extracellular calcium, the initial Ca2+ rise remained but the sustained elevation of intracellular Ca2+ was abolished, Na and K fluxes were variable and the Ca did not change. Increased Na and decreased K was marked at 2 minutes and returned to the control value after 60 minutes. The increase in Ca was an early event. Cells stimulated with EGF showed a pronounced morphological disruption, especially the mitochondria. The response of NR6/SA3 and NR6/DC7 cells (genetically engineered rodent fibroblast cell lines) to EGF stimulation was higher than that of the A431 cells, as was the resting cytoplasmic Ca2+. Untreated NR6/SA3 and NR6/DC7 cells possessed an increased Na/K ratio when compared with A431 cells.
Collapse
Affiliation(s)
- J E Beesley
- Wellcome Research Laboratories, Beckenham, Kent, U.K
| | | | | | | |
Collapse
|
35
|
Beesley JE, Foxwell N, Hall SR. X-ray microanalysis and single cell microfluorimetry for microscopical investigation of cellular reactions to pharmacological agents. Cell Biol Int 1993; 17:703. [PMID: 8374605 DOI: 10.1006/cbir.1993.1127] [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] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- J E Beesley
- Department of Pharmacology, Wellcome Research Laboratories, Beckenham, Kent, UK
| | | | | |
Collapse
|
36
|
Stewart JM, Collins DM, Watenpaugh KD, Prince E, Hall SR. Programs for phasing by entropy maximization as implemented in Xtal3.2: a crystallographic software system. Acta Cryst D 1993; 49:100-6; discussion 107. [PMID: 15299550 DOI: 10.1107/s0907444992008898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Xtal3.2, a crystallographic software package, is an international development project involving about 40 researchers over a full spectrum of crystallographic interests. This development has been supported by many national and international agencies and commercial institutions since the first version in 1983. The 1992 release, Xtal3.2, contains software for 95 different calculations. These range from the processing of raw diffraction data to interactive molecular graphics, atomic charge estimation, electronic publication preparation, and the structure solution and refinement of small and large molecules. Tests of the Xtal programs for phase determination and phase refinement by the application of 'maximum entropy' are presented.
Collapse
Affiliation(s)
- J M Stewart
- University of Maryland, College Park 20742, USA
| | | | | | | | | |
Collapse
|
37
|
Hall SR, Sigee DC, Beesley JE. Scanning X-ray microanalysis of microcarrier cultured endothelial cells: elemental changes during the transition to confluency and the effect of ionophore A23187. Scanning Microsc 1992; 6:753-62; discussion 763. [PMID: 1439667] [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: 12/27/2022]
Abstract
Porcine endothelial cells were grown on microcarrier beads and examined by scanning electron microscopy (SEM) at various times after initiation of culture. Total cell coverage on the bead surface varied from mean values of approximately 7% (3h) to 80% (96h). Beam penetration into the subcellular matrix presents a major problem with SEM X-ray microanalysis of microcarrier cultured cells and necessitates the use of an accelerating voltage not exceeding 10kV. At this voltage and below, X-ray contribution from elements present in the microcarrier bead has minimal effect on the determination of cell elemental levels. Washing the cells with 0.15M sucrose was the least perturbing of the rinsing techniques investigated, removing surface culture medium but not internal diffusible ions. X-ray microanalysis revealed detectable levels of Na, P, S, Cl, K and Ca in the cells, with well-marked changes from initial attachment to confluency. The level of K decreased from approximately 1.0% at 3h to 0.4% at 24h, with a corresponding decrease in the K/Na ratio. This unexpectedly low level of K was invariably observed after 24h, and is a genuine feature of established microcarrier culture. The effect of ionophore A23187 was determined at the 3h culture stage, and resulted in significant increases in the concentration of divalent cations (Mg2+, Ca2+), monovalent ions (Na+, Cl-) and a decrease in the level of K+.
Collapse
Affiliation(s)
- S R Hall
- Dept. Cell and Structural Biology, University of Manchester, U.K
| | | | | |
Collapse
|
38
|
Smith AP, Rusted JM, Savory M, Eaton-Williams P, Hall SR. The effects of caffeine, impulsivity and time of day on performance, mood and cardiovascular function. J Psychopharmacol 1991; 5:120-8. [PMID: 22282363 DOI: 10.1177/026988119100500205] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Two experiments were carried out to examine the effects of caffeine on performance, mood and cardiovascular function. The results showed that the effects of caffeine depended on the dose, time of administration, the function being examined and the impulsivity of the subject. Changes in blood pressure were only observed when a high dose (3 mg/kg) was used. The effects of this dose on performance depended on the impulsivity of the subject, with high impulsives performing worse in the de-caffeinated condition but getting a greater benefit from the caffeine. The high dose of caffeine also removed the post-lunch dip in sustained attention. The second experiment, which used a lower dose of caffeine (~60 mg), failed to demonstrate any caffeine x impulsivity or caffeine x time of day effects on performance. However, caffeine improved performance on a logical reasoning task and caffeine x time of day x impulsivity effects were found in analyses of visual search tasks. The mood data also support the view that the effects of caffeine depend on a combination of factors similar to those outlined for performance.
Collapse
Affiliation(s)
- A P Smith
- School of Psychology, University of Wales College of Cardiff, Cardiff CF1 3YG
| | | | | | | | | |
Collapse
|
39
|
Castleden IR, Hall SR, Nimgirawath S, Thadaniti S, White AH. The Flavonoids of Combretum quadrangulare: Crystal structures of the Polymorphic Forms of 5-Hydroxy-2-(4'-hydroxy-3',5'-dimethoxyphenyl)-3,7-dimethoxy-4H-1-benzopyran-4-one. Aust J Chem 1985. [DOI: 10.1071/ch9851177] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The following substituted 2-phenyl-4H-1-benzopyran-4-ones have been isolated from the dried flowers of Combretum quadrangulare Kurz ( Combretaceae ): 5-hydroxy-3,3′,4′,5′,7-pentamethoxy ( combretol ) (1),
3′,5-dihydroxy-3,4′,7-trimethoxy ( ayanin ) (2) and 4′,5-dihydroxy- 3,3′,5′,7-tetramethoxy (3). The last substance (3) was obtained as a mixture of two polymorphic forms (α and β) each of which was characterized by X-ray diffraction. Diffractometer data at 295 K were refined by full matrix least squares to residuals of 0.043 (1181 'observed' reflections) for the α-phase and 0.044 (1421) for the β phase of (3). Crystals of the α-phase of (3) are triclinic, Pī, a 12.663(6), b 9.592(4), c 7.444(4) Ǻ, α 102.48(3), β 101.39(4),
γ 91.72(4)°,Z 2. Crystals of the β-phase of (3) are monoclinic P21/n, a 17.139(8), b 12.728(6), c 7.845(7) Ǻ, β 95.07(6)°, Z 4. An unambiguous synthesis of (3) was also achieved.
Collapse
|
40
|
Abstract
.A new, metastable phase of lepidopterene, (5,6,11,12-tetrahydro-4b,12[1',2']:6,10b[1",2"]-dibenzenochrysene) (1), has been obtained from methylene chloride solution, exhibiting a luminescence
which differs from that of the stable form, having an absorption maximum at 580 nm rather than
560 nm. Single crystal X-ray diffraction determination of the structure of the new phase shows
it to be orthorhombic, Pbcn, a 36.75(3), b 7.229(7), c 44.85(3) Ǻ, Z 24, the structure being refined
to a residual of 0.065 for 2413 independent 'observed' reflections. Despite the relatively low precision
of the determination, it is evident that in the metastable form, the gross molecular disposition is
severely distorted. The crystal structure of dimethyllepidopterene (2) has also been determined,
and refined by least squares to a residual of 0.041 for 632 'observed' reflections. Crystals are mono-
clinic, P21/c, with a 9.607(4), b 11.564(7), c 10.576(6) Ǻ, β 107.72(4), Z 2; the molecules are
centrosymmetric.
Tetrachlorolepidopterene (31, formed by the dimerization of 1,5-dichloro-9-anthrylmethyl,
yields two crystalline forms from xylene and methylene chloride solutions which differ in their
crystal exciplex luminescence, showing emission maxima at 590 and 575 nrn respectively. Single-
crystal X-ray structure determination confirms that the two crystalline forms, α- and β-, are polymorphs of the same centrosymmetric molecular species. For the α-form, crystals are triclinic, P1 ,
a 15.374(6), b 9.858(4), c 8.000(4) Ǻ, α 83.98(4), β 83.73(3), γ 71.53(3)°, Z 2, 2138 independent
'observed' reflections being refined to a residual of 0.037; the unit cell contains two independent
centrosymmetric molecules. For the β-form, crystals are monoclinic, C2/c, a 11.03(2), b 13.67(2),
c 16.32(3) Ǻ, β 1 1 1.13(12)°, Z 4; the residual for 1554 independent reflections was 0.053.
Collapse
|
41
|
Abstract
The crystal structure of
8-hydroxy-1H-naphtho[2,1,8-mna]xanthen-1-one, C19H10O3,
obtained as an indefinite methanolsolvate, has been
determined at 295K by single-crystal X-ray diffraction methods, being refined
by full matrix least squares to a residual of 0.056 for 892 independent 'observed'
reflections. Crystals are monoclinic, P21/c, a 5.128(4), b 10.024(9), c 27.45(2) �, β 107.73(6)�, Z 4.
The packing of the molecules is typically that of charge-transfer complexes, with
an interplanar spacing of c.3.5 �.
Collapse
|
42
|
Abstract
(Z)-7-t-Butyl-5
methoxy-3-[(Z)-2?-methoxy-5,5'-dimethyl-4'-oxohex-2'-enylidene]benzofuran-2(3H)-one
has been found to undergo Diels-Alder dimerization in which the exocyclic
double bond adds to the s-cis diene
moiety. The stereochemistry of the Diels-Alder dimer was established by a
single-crystal X-ray structure determination. Crystals of the dimer, C44H56O10,
are monoclinic, P21/n, a 12.23(1),
b 19.43(2), c 18.71(2) �, β 107.76(7)�, Z 4; a residual of 0.046 was
obtained for the 2519 'observed' reflections. In the dimer, two benzofuranone moieties are situated so as to be vicinal spiro substituents of the cyclohexene
formed in the Diels-Alder addition. The bond between the two benzofuranone units is unusually long [1.597(6)�]. The
shielding of one aromatic hydrogen in the n.m.r. spectrum of the dimer results
from the disposition of the two aromatic systems.
Collapse
|
43
|
Hall SR, Skelton BW, White AH. Structural studies in the ruthenium(II)/(±)-ortho-Phenylenebis{methyl(phenyl)-phosphine/arsine) system. II. Crystal structure of trans-Dichloro[(±)-ortho-phenylenebis{methyl(phenyl)-phosphine}][(±)-ortho-phenylenebis(methyl(pheny1)-phosphine) P-oxide]ruthenium(II). Aust J Chem 1983. [DOI: 10.1071/ch9830267] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The crystal and molecular
structure of the title complex, trans-[RuCl2{(�)-o-C5H4(PMePh)2}{(�)- o-C5H4(PMePh)(P(O)MePh)}], has been established by a single-crystal X-ray
diffraction study at 295(1) K, being refined to a residual of 0.037 for 2669
independent 'observed' reflections. Crystals are orthorhombic, P212121,
a 16.655(5), b 15.805(4), c 14.823(8)
�, Z 4. The chlorine atoms lie trans
to each other in the coordination sphere of the six-coordinate ruthenium, with
the O-C6H4(PMePh)2
and o-C6H4(PMePh)(P(O)MePh) ligands being P,P? and O,P' bidentate respectively.
The ruthenium-chlorine distances are 2.434(2) and 2.425(2) �; the two mutually trans ruthenium- phosphine distances are
2.310(3) and 2.346(2) �, but that which is trans
to the oxygen is unusually short, being 2 219(2) �. The ruthenium-oxygen
distance is 2.166(5)�.
Collapse
|
44
|
Abstract
The crystal structure of
the title compound, (NH4)Ag(SCN)2, has been redetermined at 295(1) K. Crystals are monoclinic, P21/n,
a 7.207(4), b 23.84(1), c 4.014(4) �,
β 95.24(7)�, Z 4. The structure comprises two-dimensional polymeric anion
layers parallel to ac, interleaved by
N. . .H hydrogen-bonded ammonium cations. The silver atom is pseudo-tetrahedrally four-coordinated by terminal and triply
bridging S thiocyanate groups (Ag-S, 2.469(4);
2.609-2.773(5) �). The structure was refined
to a residual of 0.051 for 550 'observed' reflections.
Collapse
|
45
|
Hall SR, Skelton BW, White AH. Structural studies in the ruthenium(II)/(±)-ortho-Phenylenebis{methyl(phenyl)-phosphine/arsine} system. III. Crystal structures of Dichlorocarbonyl(dimethyl sulfoxide)-[ortho-phenylenebis {methyl(phenyl)phosphine}]ruthenium(II) and of cis-dicarbonyldichloro[(±)-ortho-phenylenebis{methyl(phenyl)arsine}]ruthenium(II). Aust J Chem 1983. [DOI: 10.1071/ch9830271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The crystal and molecular
structure of the title complex, cis-[Ru(CO)Cl2(dmso)(opmpp)] (1) (dmso ≡ dimethyl
sulfoxide, Me2SO; opmpp ≡ (�)-ortho-phenylenebis
{methyl(phenyl)phosphine},[o-C6H4(PMePh)2]), has been determined by a
single-crystal X-ray diffraction study at 295(1) K, being refined to a residual
of 0.050 for 6115 independent 'observed' reflections. Crystals are monoclinic,
P21/c, a 11.180(7), b 12.957(6), c 17.567(9) �, β 90.88(5)�, Z 4. The ruthenium-chlorine
distances, trans to phosphine and
carbonyl ligands, respectively, are 2.469(2), 2.446(2) �; the
ruthenium-phosphine distances, trans
to the chloride and dimethyl sulfoxide ligands, respectively, are 2.292(1),
2.313(2) �. Ruthenium-sulfur (dmso) is 2.380(2) �,
while the ruthenium-carbon(CO) is c. 1.72 �. For cis-[Ru(CO)2Cl2(opmpa)] (2) (opmpa ≡ (�)-ortho-phenylenebis{methyl(phenyl)-
arsine}, [o-C6H4(AsMePh)2]), refinement led to a residual of
0.036 for 2423 independent 'observed' reflections. Crystals are monoclinic, P21/c,
a 10.497(3), b 11.586(7), c 20.341(9) �,
β 105.31(4)�, Z 4. Ruthenium-arsine distances, trans to carbonyl and chlorine ligands, respectively, are 2.404(1),
2.455(1) �. Ruthenium-chlorine distances,
trans to arsine and carbonyl ligands, respectively, are 2.443(3), 2.433(2) �,
while ruthenium-carbon(CO) distances, trans
to arsine and chlorine ligands, respectively, are 1 .920(8), 1 .872(8) �.
Collapse
|
46
|
Becker H, Hall SR, Skelton BW, White AH. On the molecular geometry of 1,2-Di(9-anthryl)ethanes. Crystal structures of two crystalline modifications of 1,2-Bis(10-acetoxy-9-anthryl)ethane. Aust J Chem 1982. [DOI: 10.1071/ch9822357] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In order to define
molecular conformations, the crystal structures of two crystalline phases of
1,2- bis(10-acetoxy-9-anthryl)ethane have been determined by single-crystal
X-ray diffraction methods at 295 K. Both phases are monoclinic, P21/c.
For the 'α'-phase, a 7.609(2), b 14.469(3), c 11.358(3) � β, 96.39(2)�, Z 2. The final residual was 0.034
for 1341 'observed' reflections; the molecule is centrosymmetric about a
crystallographic inversion centre. For the 'β'-phase, a 31.264(15), b 5.248(3),
c 15.718(6) �,β
97.84(3)�, Z 4, the final residual was 0.052 for 972 'observed' reflections. In
this structure two independent, centrosymmetric molecules are found. In both
α- and β-form, the molecular conformation is thus 'stretched' rather
than 'eclipsed'. The packing patterns of the two modifications have been
correlated with their crystal luminescence properties.
Collapse
|
47
|
Hall SR, Nimgirawath S, Raston CL, Sittatrakul A, Thadaniti S, Thirasasana N, White AH. Crystal structure of zerumbone [(E,E,E)-2,6,9,9-Tetramethylcycloundeca-2,6,10-trien-1-one]. Aust J Chem 1981. [DOI: 10.1071/ch9812243] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The crystal structure of zerumbone, C15H22O, extracted from
the rhizomes of Zingiber zerumbet
Smith, has been determined by single-crystal X-ray diffraction at 295(1) K and
refined by least squares to a residual of 0.051 for 925 'observed' reflections.
Crystals are monoclinic, space group P21/c, a 9.036(3), b 9.712(5), c 15.643(6) �, β 97.19(3)�, Z = 4.
Although the molecule has no chiral centre, the
presence of the three trans double
bonds confers considerable distortion and rigidity on the eleven-membered ring and renders the whole molecule chiral and potentially resolvable.
Collapse
|
48
|
Hall SR, Raston CL, White AH. Crystal structure of 3,3a',5,5'-tetra-t-butyl-2'-(3,5-di-t-butyl-4-hydroxyphenyl)-7'-[l -(3,5-di-t-butyl-4-hydroxypheny1)ethy1idene]-3a',4',7',7a'-tetrahydrospiro-[cyclohexa-2,5-diene-1,1 '-[1H]indene]-4,4'-dione. Aust J Chem 1980. [DOI: 10.1071/ch9800295] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The crystal structure of
the title compound, C60H86O4, has been
determined at 295 K by single-crystal X-ray diffraction and refined by least
squares to a residual of 0.073 for 3399 'observed' reflections. Crystals are
monoclinic, P21/n, a 18.999(10), b 12.149(7), c 27.589(10) Ǻ,
β 107.32(6)°, Z 4. The compound is solvated with ether to the extent of
about two solvent molecules per unit cell.
Collapse
|
49
|
Hall SR. Are you ready for stomatology? Dent Stud 1978; 56:50-2. [PMID: 288652] [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: 12/14/2022]
|
50
|
Hall SR, Skelton BW, White AH. Crystal structure of (1,7,8,9-η-Bicyclo[5,2,0]nona-1(7),2,5,8-tetraen-4-one)tricarbonyliron(0). Aust J Chem 1978. [DOI: 10.1071/ch9781619] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The crystal structure of
the title compound, [Fe(CO)3(C9H6O)], has been
determined from single-crystal X-ray diffraction data at 295 K and refined by
full-matrix least squares to a residual of 0.039 (2160 'observed' reflections).
Crystals are monoclinic, P21/c, a 9.326(5), b 12.293(5), c 10.342(4)
Ǻ, β 115.77(3)°, Z 4. The iron atom is symmetrically bound to the
four atoms of the cyclobutadiene ring (<Fe- C> 2.055 Ǻ).
Collapse
|