1
|
Dickman LT, Jonko AK, Linn RR, Altintas I, Atchley AL, Bär A, Collins AD, Dupuy J, Gallagher MR, Hiers JK, Hoffman CM, Hood SM, Hurteau MD, Jolly WM, Josephson A, Loudermilk EL, Ma W, Michaletz ST, Nolan RH, O'Brien JJ, Parsons RA, Partelli‐Feltrin R, Pimont F, Resco de Dios V, Restaino J, Robbins ZJ, Sartor KA, Schultz‐Fellenz E, Serbin SP, Sevanto S, Shuman JK, Sieg CH, Skowronski NS, Weise DR, Wright M, Xu C, Yebra M, Younes N. Integrating plant physiology into simulation of fire behavior and effects. New Phytol 2023; 238:952-970. [PMID: 36694296 PMCID: PMC10952334 DOI: 10.1111/nph.18770] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Wildfires are a global crisis, but current fire models fail to capture vegetation response to changing climate. With drought and elevated temperature increasing the importance of vegetation dynamics to fire behavior, and the advent of next generation models capable of capturing increasingly complex physical processes, we provide a renewed focus on representation of woody vegetation in fire models. Currently, the most advanced representations of fire behavior and biophysical fire effects are found in distinct classes of fine-scale models and do not capture variation in live fuel (i.e. living plant) properties. We demonstrate that plant water and carbon dynamics, which influence combustion and heat transfer into the plant and often dictate plant survival, provide the mechanistic linkage between fire behavior and effects. Our conceptual framework linking remotely sensed estimates of plant water and carbon to fine-scale models of fire behavior and effects could be a critical first step toward improving the fidelity of the coarse scale models that are now relied upon for global fire forecasting. This process-based approach will be essential to capturing the influence of physiological responses to drought and warming on live fuel conditions, strengthening the science needed to guide fire managers in an uncertain future.
Collapse
Affiliation(s)
- L. Turin Dickman
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Alexandra K. Jonko
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Rodman R. Linn
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Ilkay Altintas
- San Diego Supercomputer Center and Halicioglu Data Science InstituteUniversity of California San DiegoLa JollaCA92093USA
| | - Adam L. Atchley
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Andreas Bär
- Department of BotanyUniversity of Innsbruck6020InnsbruckAustria
| | - Adam D. Collins
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Jean‐Luc Dupuy
- Ecologie des Forêts Méditerranéennes (URFM)INRAe84914AvignonFrance
| | | | | | - Chad M. Hoffman
- Department of Forest and Rangeland StewardshipColorado State UniversityFort CollinsCO80523USA
| | - Sharon M. Hood
- Rocky Mountain Research StationUSDA Forest ServiceMissoulaMT59801USA
| | | | - W. Matt Jolly
- Rocky Mountain Research StationUSDA Forest ServiceMissoulaMT59801USA
| | - Alexander Josephson
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | | | - Wu Ma
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Sean T. Michaletz
- Department of Botany and Biodiversity Research CentreThe University of British ColumbiaVancouverBCV6T 1Z4Canada
| | - Rachael H. Nolan
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2753Australia
- NSW Bushfire Risk Management Research HubWollongongNSW2522Australia
| | | | | | - Raquel Partelli‐Feltrin
- Department of Botany and Biodiversity Research CentreThe University of British ColumbiaVancouverBCV6T 1Z4Canada
| | - François Pimont
- Ecologie des Forêts Méditerranéennes (URFM)INRAe84914AvignonFrance
| | - Víctor Resco de Dios
- School of Life Sciences and EngineeringSouthwest University of Science and TechnologyMianyang621010China
- Department of Crop and Forest Sciences and JRU CTFC‐AGROTECNIOUniversitat de LleidaLleida25198Spain
| | - Joseph Restaino
- Fire and Resource Assessment ProgramCalifornia Department of Forestry and Fire ProtectionSouth Lake TahoeCA96155USA
| | - Zachary J. Robbins
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Karla A. Sartor
- Environmental Protection and Compliance DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Emily Schultz‐Fellenz
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Shawn P. Serbin
- Environmental and Climate Sciences DepartmentBrookhaven National LaboratoryUptonNY11973USA
| | - Sanna Sevanto
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Jacquelyn K. Shuman
- Climate and Global Dynamics Laboratory, Terrestrial Sciences SectionNational Center for Atmospheric ResearchBoulderCO80305USA
| | - Carolyn H. Sieg
- Rocky Mountain Research StationUSDA Forest ServiceFlagstaffAZ86001USA
| | | | - David R. Weise
- Pacific Southwest Research StationUSDA Forest ServiceRiversideCA92507USA
| | - Molly Wright
- Cibola National ForestUSDA Forest ServiceAlbuquerqueNM87113USA
| | - Chonggang Xu
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Marta Yebra
- Fenner School of Environment and SocietyAustralian National UniversityCanberraACT2601Australia
- School of EngineeringAustralian National UniversityCanberraACT2601Australia
| | - Nicolas Younes
- Fenner School of Environment and SocietyAustralian National UniversityCanberraACT2601Australia
| |
Collapse
|
2
|
Nocentini A, Kominoski JS, O'Brien JJ, Redwine J. Fire intensity and ecosystem oligotrophic status drive relative phosphorus release and retention in freshwater marshes. Ecosphere 2022. [DOI: 10.1002/ecs2.4263] [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: 11/09/2022] Open
Affiliation(s)
- Andrea Nocentini
- Institute of Environment and Department of Biological Sciences Florida International University Miami Florida USA
- South Florida Natural Resources Center Everglades National Park Homestead Florida USA
| | - John S. Kominoski
- Institute of Environment and Department of Biological Sciences Florida International University Miami Florida USA
| | - Joseph J. O'Brien
- U.S. Department of Agriculture U.S. Forest Service Athens Georgia USA
| | - Jed Redwine
- South Florida Natural Resources Center Everglades National Park Homestead Florida USA
| |
Collapse
|
3
|
Robbins ZJ, Loudermilk EL, Reilly MJ, O'Brien JJ, Jones K, Gerstle CT, Scheller RM. Delayed fire mortality has long‐term ecological effects across the Southern Appalachian landscape. Ecosphere 2022. [DOI: 10.1002/ecs2.4153] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Zachary J. Robbins
- Forestry and Environmental Resources Department North Carolina State University Raleigh North Carolina USA
| | - E. Louise Loudermilk
- Southern Research Station, Center for Forest Disturbance Science Athens Prescribed Fire Laboratory, U.S. Forest Service Athens Georgia USA
| | - Matthew J. Reilly
- Pacific Northwest Research Station Western Wildland Environmental Threat Assessment, U.S. Forest Service Corvallis Oregon USA
| | - Joseph J. O'Brien
- Southern Research Station, Center for Forest Disturbance Science Athens Prescribed Fire Laboratory, U.S. Forest Service Athens Georgia USA
| | - Kate Jones
- Center for Geospatial Analytics North Carolina State University Raleigh North Carolina USA
| | - Christopher T. Gerstle
- Forestry and Environmental Resources Department North Carolina State University Raleigh North Carolina USA
| | - Robert M. Scheller
- Forestry and Environmental Resources Department North Carolina State University Raleigh North Carolina USA
| |
Collapse
|
4
|
Terando A, Hiers JK, Williams M, Goodrick SL, O'Brien JJ. Is there a dry season in the Southeast US? Glob Chang Biol 2021; 27:713-715. [PMID: 33064872 DOI: 10.1111/gcb.15399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
Fill et al. (Global Change Biology, 25, 3562-3569, 2019) reported significant increases in dry season length over the past 120 years in the Southeast US, suggesting increased wildfire risk in a region associated with a frequent fire regime. We identified two flaws that call into question the findings and their relevance to regional wildfire risk. First, with the exception of Florida, there is little evidence for a climatologically meaningful 'dry season' in the Southeast because most areas experience relatively evenly distributed monthly precipitation. Second, the sampling method used to derive Cumulative Rainfall Anomalies does not appear to actually reflect a bootstrap sample as described.
Collapse
Affiliation(s)
- Adam Terando
- US Geological Survey, Southeast Climate Adaptation Science Center, Raleigh, NC, USA
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, USA
| | | | - Marcus Williams
- USDA Forest Service Southern Research Station, Athens, GA, USA
| | | | | |
Collapse
|
5
|
Flanagan SA, Bhotika S, Hawley C, Starr G, Wiesner S, Hiers JK, O'Brien JJ, Goodrick S, Callaham MA, Scheller RM, Klepzig KD, Taylor RS, Loudermilk EL. Quantifying carbon and species dynamics under different fire regimes in a southeastern U.S. pineland. Ecosphere 2019. [DOI: 10.1002/ecs2.2772] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Steven A. Flanagan
- Wildland Fire Science Program Tall Timbers Research Station 13093 Henry Beadel Drive Tallahassee Florida 32312 USA
| | - Smriti Bhotika
- Center for Forest Disturbance Science Southern Research Center U.S. Forest Service 320 Green Street Athens Georgia 30602 USA
- AAAS 1200 New York Avenue, NW Washington D.C. 20005 USA
| | - Christie Hawley
- Center for Forest Disturbance Science Southern Research Center U.S. Forest Service 320 Green Street Athens Georgia 30602 USA
| | - Gregory Starr
- Department of Biological Sciences University of Alabama Tuscaloosa Alabama 35487 USA
| | - Susanne Wiesner
- Department of Biological Sciences University of Alabama Tuscaloosa Alabama 35487 USA
| | - J. Kevin Hiers
- Wildland Fire Science Program Tall Timbers Research Station 13093 Henry Beadel Drive Tallahassee Florida 32312 USA
| | - Joseph J. O'Brien
- Center for Forest Disturbance Science Southern Research Center U.S. Forest Service 320 Green Street Athens Georgia 30602 USA
| | - Scott Goodrick
- Center for Forest Disturbance Science Southern Research Center U.S. Forest Service 320 Green Street Athens Georgia 30602 USA
| | - Mac A. Callaham
- Center for Forest Disturbance Science Southern Research Center U.S. Forest Service 320 Green Street Athens Georgia 30602 USA
| | - Robert M. Scheller
- Department of Forestry and Environmental Resources North Carolina State University Raleigh North Carolina 27695 USA
| | - Kier D. Klepzig
- Joseph W. Jones Ecological Research Center 3988 Jones Center Dr. Newton Georgia 39870 USA
| | - R. Scott Taylor
- Joseph W. Jones Ecological Research Center 3988 Jones Center Dr. Newton Georgia 39870 USA
| | - E. Louise Loudermilk
- Center for Forest Disturbance Science Southern Research Center U.S. Forest Service 320 Green Street Athens Georgia 30602 USA
| |
Collapse
|
6
|
Dell JE, Salcido DM, Lumpkin W, Richards LA, Pokswinski SM, Loudermilk EL, O'Brien JJ, Dyer LA. Interaction Diversity Maintains Resiliency in a Frequently Disturbed Ecosystem. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00145] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
7
|
Dell JE, Richards LA, O'Brien JJ, Loudermilk EL, Hudak AT, Pokswinski SM, Bright BC, Hiers JK, Williams BW, Dyer LA. Overstory-derived surface fuels mediate plant species diversity in frequently burned longleaf pine forests. Ecosphere 2017. [DOI: 10.1002/ecs2.1964] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Jane E. Dell
- Ecology, Evolution, and Conservation Biology; University of Nevada, Reno; 1664 N. Virginia Street Reno Nevada 89557 USA
| | - Lora A. Richards
- Ecology, Evolution, and Conservation Biology; University of Nevada, Reno; 1664 N. Virginia Street Reno Nevada 89557 USA
| | - Joseph J. O'Brien
- Center for Forest Disturbance Science; Southern Research Center; U.S. Forest Service; 320 Green Street Athens Georgia 30602 USA
| | - E. Louise Loudermilk
- Center for Forest Disturbance Science; Southern Research Center; U.S. Forest Service; 320 Green Street Athens Georgia 30602 USA
| | - Andrew T. Hudak
- Forestry Sciences Laboratory; Rocky Mountain Research Station; U.S. Forest Service; 1221 South Main Street Moscow Idaho 83843 USA
| | - Scott M. Pokswinski
- Wildland Fire Science Program; Tall Timbers Research Station; 13093 Henry Beadel Drive Tallahassee Florida 32312 USA
| | - Benjamin C. Bright
- Forestry Sciences Laboratory; Rocky Mountain Research Station; U.S. Forest Service; 1221 South Main Street Moscow Idaho 83843 USA
| | - J. Kevin Hiers
- Wildland Fire Science Program; Tall Timbers Research Station; 13093 Henry Beadel Drive Tallahassee Florida 32312 USA
| | - Brett W. Williams
- Air Force Wildland Fire Center; Eglin AFB; 107 FL-85 Niceville Florida 32578 USA
| | - Lee A. Dyer
- Ecology, Evolution, and Conservation Biology; University of Nevada, Reno; 1664 N. Virginia Street Reno Nevada 89557 USA
| |
Collapse
|
8
|
Louise Loudermilk E, Kevin Hiers J, Pokswinski S, O'Brien JJ, Barnett A, Mitchell RJ. The path back: oaks (
Quercus
spp.) facilitate longleaf pine (
Pinus palustris
) seedling establishment in xeric sites. Ecosphere 2016. [DOI: 10.1002/ecs2.1361] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- E. Louise Loudermilk
- Center for Forest Disturbance ScienceSouthern Research CenterUS Forest Service 320 Green Street Athens Georgia 30602 USA
| | - J. Kevin Hiers
- Office of Environmental Stewardship735 University AvenueThe University of the South Sewanee Tennessee 37383 USA
| | - Scott Pokswinski
- University of Nevada at Reno 1664 N Virginia Street Reno Nevada 89503 USA
| | - Joseph J. O'Brien
- Center for Forest Disturbance ScienceSouthern Research CenterUS Forest Service 320 Green Street Athens Georgia 30602 USA
| | - Analie Barnett
- The Nature Conservancy 100 Peachtree Street NW Atlanta Georgia 30303 USA
| | - Robert J. Mitchell
- Joseph W. Jones Ecological Research Center Route 2 Box 2324 Newton Georgia 31770 USA
| |
Collapse
|
9
|
Wenk ES, Callaham MA, O'Brien JJ, Hanson PJ. Soil Macroinvertebrate Communities Across a Productivity Gradient in Deciduous Forests of Eastern North America. Northeast Nat (Steuben) 2016. [DOI: 10.1656/045.023.0103] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
10
|
O'Brien JJ, Baglole CJ, Garcia-Bates TM, Blumberg N, Francis CW, Phipps RP. 15-deoxy-Delta12,14 prostaglandin J2-induced heme oxygenase-1 in megakaryocytes regulates thrombopoiesis. J Thromb Haemost 2009; 7:182-9. [PMID: 18983509 PMCID: PMC2821682 DOI: 10.1111/j.1538-7836.2008.03191.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [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: 01/31/2023]
Abstract
BACKGROUND Platelet production is an intricate process that is poorly understood. Recently, we demonstrated that the natural peroxisome proliferator-activated receptor gamma (PPARgamma) ligand, 15-deoxy-Delta(12,14) prostaglandin J(2) (15d-PGJ(2)), augments platelet numbers by increasing platelet release from megakaryocytes through the induction of reactive oxygen species (ROS). 15d-PGJ(2) can exert effects independent of PPARgamma, such as increasing oxidative stress. Heme oxygenase-1 (HO-1) is a potent antioxidant and may influence platelet production. OBJECTIVES To further investigate the influence of 15d-PGJ(2) on megakaryocytes and to understand whether HO-1 plays a role in platelet production. METHODS Meg-01 cells (a primary megakaryoblastic cell line) and primary human megakaryocytes derived from cord blood were used to examine the effects of 15d-PGJ(2) on HO-1 expression in megakaryocytes and their daughter platelets. The role of HO-1 activity in thrombopoiesis was studied using established in vitro models of platelet production. RESULTS AND CONCLUSIONS 15d-PGJ(2) potently induced HO-1 protein expression in Meg-01 cells and primary human megakaryocytes. The platelets produced from these megakaryocytes also expressed elevated levels of HO-1. 15d-PGJ(2)-induced HO-1 was independent of PPARgamma, but could be replicated using other electrophilic prostaglandins, suggesting that the electrophilic properties of 15d-PGJ(2) were important for HO-1 induction. Interestingly, inhibiting HO-1 activity enhanced ROS generation and augmented 15d-PGJ(2)-induced platelet production, which could be attenuated by antioxidants. These new data reveal that HO-1 negatively regulates thrombopoiesis by inhibiting ROS.
Collapse
Affiliation(s)
- J J O'Brien
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | | | | | | | | | | |
Collapse
|
11
|
O'Brien JJ, Hiers JK, Callaham MA, Mitchell RJ, Jack SB. Interactions among overstory structure, seedling life-history traits, and fire in frequently burned neotropical pine forests. Ambio 2008; 37:542-547. [PMID: 19205176 DOI: 10.1579/0044-7447-37.7.542] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Fire-dependent pine forests in the Caribbean Basin cover extensive areas in the coastal plain of the Caribbean Sea and Gulf of Mexico and on several islands in the Bahamas Archipelago, Cuba, Hispaniola, and the Honduran Bay islands. These forests are high in conservation value but, unfortunately, remain mostly unprotected. Moreover, even though they are fire dependent, the use of fire for forest management often suffers from poor public perception and is prohibited by law in several countries. In this paper, we describe the fundamental links among fire, forest regeneration, and forest persistence in these ecosystems. We identify two general strategies based on the presence or absence of pine seedling adaptations for fire survival and describe management implications of these two strategies. We also introduce conceptual models describing fire, forest structure, and regeneration strategy linkages.
Collapse
Affiliation(s)
- Joseph J O'Brien
- US Forest Service Center for Forest Disturbance Science, Athens, Georgia 30602, USA.
| | | | | | | | | |
Collapse
|
12
|
|
13
|
Abstract
Longleaf pine (Pinus palustris) woodlands and savannas are among the most frequently burned ecosystems in the world with fire return intervals of 1-10 years. This fire regime has maintained high levels of biodiversity in terms of both species richness and endemism. Land use changes have reduced the area of this ecosystem by >95%, and inadequate fire frequencies threaten many of the remnants today. In the absence of frequent fire, rapid colonization of hardwoods and shrubs occurs, and a broad-leaved midstory develops. This midstory encroachment has been the focus of much research and management concern, largely based on the assumption that the midstory reduces understory plant diversity through direction competition via light interception. The general application of this mechanism of degradation is questionable, however, because midstory density, leaf area, and hardwood species composition vary substantially along a soil moisture gradient from mesic to extremely xeric sites. Reanalysis of recently reported data from xeric longleaf pine communities suggests that the development of the forest floor, a less conspicuous change in forest structure, might cause a decline in plant biodiversity when forests remain unburned. We report here a test of the interactions among fire, litter accumulation, forest floor development, and midstory canopy density on understory plant diversity. Structural equation modeling showed that within xeric sites, forest floor development was the primary factor explaining decreased biodiversity. The only effects of midstory development on biodiversity were those mediated through forest floor development. Boundary line analysis of functional guilds of understory plants showed sensitivity to even minor development of the forest floor in the absence of fire. These results challenge the prevailing management paradigm and suggest that within xeric longleaf pine communities, the primary focus of managed fire regime should be directed toward the restoration of forest floor characteristics rather than the introduction of high-intensity fires used to regulate midstory structure.
Collapse
Affiliation(s)
- J Kevin Hiers
- Jones Ecological Research Center, Nenton, Georgia 31770, USA.
| | | | | | | |
Collapse
|
14
|
Mills SL, O'Brien JJ, Li W, O'Brien J, Massey SC. Rod pathways in the mammalian retina use connexin 36. J Comp Neurol 2001; 436:336-50. [PMID: 11438934 PMCID: PMC1922340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Many neurons in the mammalian retina are coupled by means of gap junctions. Here, we show that, in rabbit retina, an antibody to connexin 36 heavily labels processes of AII amacrine cells, a critical interneuron in the rod pathway. Image analysis indicates that Cx36 is primarily located at dendritic crossings between overlapping AII amacrine cells. This finding suggests that Cx36 participates in homotypic gap junctions between pairs of AII amacrine cells. Cx36 was also found at AII/cone bipolar contacts, previously shown to be gap junction sites. This finding suggests that Cx36 participates at gap junctions that may be heterotypic. These results place an identified neuronal connexin in the context of a well-defined retinal circuit. The absence of Cx36 in many other neurons known to be coupled suggests the presence of additional unidentified connexins in mammalian neurons. Conversely, Cx36 labeling in other regions of the retina is not associated with AII amacrine cells, indicating some other cell types use Cx36.
Collapse
Affiliation(s)
- S L Mills
- Department of Ophthalmology and Visual Science, University of Texas at Houston - Health Science Center, Houston, Texas 77030, USA.
| | | | | | | | | |
Collapse
|
15
|
Avila G, O'Brien JJ, Dirksen RT. Excitation--contraction uncoupling by a human central core disease mutation in the ryanodine receptor. Proc Natl Acad Sci U S A 2001; 98:4215-20. [PMID: 11274444 PMCID: PMC31205 DOI: 10.1073/pnas.071048198] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [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: 01/02/2001] [Accepted: 01/30/2001] [Indexed: 11/18/2022] Open
Abstract
Central core disease (CCD) is a human congenital myopathy characterized by fetal hypotonia and proximal muscle weakness that is linked to mutations in the gene encoding the type-1 ryanodine receptor (RyR1). CCD is thought to arise from Ca(2+)-induced damage stemming from mutant RyR1 proteins forming "leaky" sarcoplasmic reticulum (SR) Ca(2+) release channels. A novel mutation in the C-terminal region of RyR1 (I4898T) accounts for an unusually severe and highly penetrant form of CCD in humans [Lynch, P. J., Tong, J., Lehane, M., Mallet, A., Giblin, L., Heffron, J. J., Vaughan, P., Zafra, G., MacLennan, D. H. & McCarthy, T. V. (1999) Proc. Natl. Acad. Sci. USA 96, 4164--4169]. We expressed in skeletal myotubes derived from RyR1-knockout (dyspedic) mice the analogous mutation engineered into a rabbit RyR1 cDNA (I4897T). Here we show that homozygous expression of I4897T in dyspedic myotubes results in a complete uncoupling of sarcolemmal excitation from voltage-gated SR Ca(2+) release without significantly altering resting cytosolic Ca(2+) levels, SR Ca(2+) content, or RyR1-mediated enhancement of dihydropyridine receptor (DHPR) channel activity. Coexpression of both I4897T and wild-type RyR1 resulted in a 60% reduction in voltage-gated SR Ca(2+) release, again without altering resting cytosolic Ca(2+) levels, SR Ca(2+) content, or DHPR channel activity. These findings indicate that muscle weakness suffered by individuals possessing the I4898T mutation involves a functional uncoupling of sarcolemmal excitation from SR Ca(2+) release, rather than the expression of overactive or leaky SR Ca(2+) release channels.
Collapse
Affiliation(s)
- G Avila
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | | | | |
Collapse
|
16
|
Stromdahl EY, Evans SR, O'Brien JJ, Gutierrez AG. Prevalence of infection in ticks submitted to the human tick test kit program of the U.S. Army Center for Health Promotion and Preventive Medicine. J Med Entomol 2001; 38:67-74. [PMID: 11268694 DOI: 10.1603/0022-2585-38.1.67] [Citation(s) in RCA: 39] [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] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In 1997, ticks removed from humans and received alive by the Tick-Borne Disease Laboratory of the U.S. Army Center for Health Promotion and Preventive Medicine (USACHPPM) were tested for pathogens by polymerase chain reaction (PCR). Thirty-three of 222 (15%) Amblyomma americanum (L.) DNAs produced amplicons of the expected size of Ehrlichia chaffeensis Anderson, Dawson & Wilson and 26/222 (12%) produced amplicons indicating Borrelia burgdorferi Johnson, Schmid, Hyde, Steigalt & Brenner. Five (2%) appeared to be co-infected with both organisms. Thirteen of 308 (4%) Dermacentor variabilis (Say) were PCR-positive for spotted fever group rickettsiae. Restriction fragment-length polymorphism analysis indicated all were Rickettsia montana. One hundred twenty-seven D. variabilis from Monroe County, WI, were tested for B. burgdorferi and 14 (11%) were positive. Five of 24 (21%) Ixodes scapularis Say were positive for B. burgdorferi and one (2%) was positive for the agent of human granulocytic ehrlichiosis. Different species of ticks transmit different pathogens, and most tick-borne diseases have similar early symptoms, therefore knowing the species and infection status of the tick enhances the physician's ability to consider tick-borne agents as a potential cause of disease and recommend appropriate therapy. Ongoing surveillance of the vector species of human diseases provides an additional estimate of human encounters with infected ticks, and testing ticks removed from humans may increase our knowledge of the vector status of tick species for transmitting tick-borne pathogens.
Collapse
Affiliation(s)
- E Y Stromdahl
- U.S. Army Center for Health Promotion and Preventive Medicine, Entomological Sciences Program, Aberdeen Proving Ground, MD 21010-5403, USA
| | | | | | | |
Collapse
|
17
|
Stromdahl EY, Randolph MP, O'Brien JJ, Gutierrez AG. Ehrlichia chaffeensis (Rickettsiales: Ehrlichieae) infection in Amblyomma americanum (Acari: Ixodidae) at Aberdeen Proving Ground, Maryland. J Med Entomol 2000; 37:349-356. [PMID: 15535577 DOI: 10.1093/jmedent/37.3.349] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Human monocytic ehrlichiosis (HME) is a sometimes fatal, emerging tick-borne disease caused by the bacterium Ehrlichia chaffeensis. It is frequently misdiagnosed because its symptoms mimic those of the flu. Current evidence indicates that Amblyomma americanum (L.), the lone star tick, is the major vector of HME. To determine if E. chaffeensis is present in ticks at Aberdeen Proving Ground, MD, questing A. americanum ticks were collected from 33 sites. Nucleic acid was extracted from 34 adult and 81 nymphal pools. Sequences diagnostic for E. chaffeensis from three different loci (16S rRNA, 120-kDa protein, and a variable-length polymerase chain reaction [PCR] target, or VLPT) were targeted for amplification by the PCR. Fifty-two percent of the collection sites yielded pools infected with E. chaffeensis, confirming the presence and widespread distribution of E. chaffeensis at Aberdeen Proving Ground. Analysis with the both the 120-kDa protein primers and the VLPT primers showed that genetic variance exists. A novel combination of variance for the two loci was detected in two tick pools. The pathogenic implications of genetic variation in E. chaffeensis are as yet unknown.
Collapse
Affiliation(s)
- E Y Stromdahl
- Entomological Sciences Program, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD 21010-5403, USA
| | | | | | | |
Collapse
|
18
|
Ririe DG, O'Brien JJ. Sevoflurane use in Tetralogy of Fallot: is it the best choice? Paediatr Anaesth 2000; 10:227-9. [PMID: 10787272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
|
19
|
Abstract
The near-infrared electronic transition of CuCl, occurring in the region of 745 nm, was recorded using intracavity laser absorption spectroscopy. The (0, 0), (1, 1), and (2, 2) vibronic bands were analyzed, and from this the molecular constants for the two electronic states were derived. Originally assigned as A' (3)Sigma(+)-X(1)Sigma(+), we have confirmed that this transition does not connect to the ground state, but occurs between two unknown excited states. The excited CuCl molecules were produced in a copper hollow cathode, operated using argon and a small amount of CCl(4). Line positions were referenced to iodine spectra observed from a heated extracavity cell using the broadband spectral output of the intracavity laser as the light source. Copyright 2000 Academic Press.
Collapse
Affiliation(s)
- LC O'Brien
- Department of Chemistry, Southern Illinois University at Edwardsville, Edwardsville, Illinois, 62026-1652
| | | | | |
Collapse
|
20
|
Gastinger MJ, O'Brien JJ, Larsen NB, Marshak DW. Histamine immunoreactive axons in the macaque retina. Invest Ophthalmol Vis Sci 1999; 40:487-95. [PMID: 9950609 PMCID: PMC3342641] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
PURPOSE The goal of these experiments was to identify the neurotransmitter in centrifugal axons of the macaque retina. METHODS Macaca mulatta retinas and optic nerves were fixed overnight in carbodiimide and labeled with an antiserum to histamine with the use of an immunofluorescence technique. RESULTS Several large histamine-immunoreactive axons ran from the optic nerve head to the peripheral retina, where they branched extensively and terminated in the inner plexiform layer, occasionally alongside retinal blood vessels. Other axons that emerged from the optic nerve head ran in the optic fiber layer to the central retina, circled the fovea, and then returned to the optic disc. These may be the source of histamine-immunoreactive axons that have been observed in central visual areas. No labeled cell bodies were present in the retina. Because perikarya in the posterior hypothalamus are the only known source of histamine in the primate central nervous system and because neurons there can be retrogradely labeled from the cut optic nerve, the histamine-immunoreactive axons must have originated there. CONCLUSIONS Centrifugal axons in the macaque retina are part of the system of axons containing histamine that originate in the hypothalamus and project throughout the brain. Because the activity of these neurons is highest during the morning, histamine might play a role in preparing the retina to operate in daylight. The contacts of histamine-immunoreactive axons with blood vessels suggest that histamine may also play a role in regulating the retinal microvasculature.
Collapse
Affiliation(s)
- M J Gastinger
- Department of Neurobiology and Anatomy, University of Texas-Houston Medical School, 77030, USA
| | | | | | | |
Collapse
|
21
|
Kayes SG, Shaneyfelt RC, Monteiro C, O'Brien JJ. Overproduction of SM28GST in a baculovirus expression vector and its use to evaluate the in vivo immune responses of mice vaccinated against Schistosoma mansoni with naked DNA encoding the SM28GST gene. J Parasitol 1998; 84:764-70. [PMID: 9714208] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
To evaluate the immune responses of mice vaccinated intramuscularly with naked DNA encoding a single parasite-derived gene, sufficient quantities of protein are necessary for use in the immunological assays. A plasmid carrying the cDNA encoding the entire sequence for the 28-kDa Schistosoma mansoni glutathione S-transferase (Sm28GST) was used as a source of naked DNA to vaccinate mice. Using polymerase chain reaction employing custom primers to add Eco RI and Hind III restriction sites at the 5' and 3' ends, respectively, a 651-bp fragment was amplified from the vaccine plasmid. This product was isolated, ligated into the pFastBac HTb donor plasmid containing a 6X histidine (6X-his) tag, and transposed into the baculovirus expression vector system. Following blue white selection screening, high molecular weight DNA was isolated and transfected in Sf21 insect ovary cells using a liposomal preparation. Culture medium containing infective virus particles was used to infect a series of Sf21 cultures and the cells were lysed after 3-5 days. The lysates were subjected to immobilized metal (Ni-NTA) affinity chromatography from which the 6X-his-tagged recombinant Sm28GST was eluted in 250 mM imidazole. The eluted protein was probed with a polyclonal rabbit antibody specific for the Sm28GST and subsequently recognized using a monoclonal antibody specific for the 6X-his tag following concentration of the pooled fractions. Mice were vaccinated intramuscularly with purified plasmid DNA encoding either the Sm28GST or firefly luciferase. Skin tests performed using recombinant Sm28GST were positive in only those mice vaccinated with naked DNA encoding the Sm28GST gene. In a different group of experimental mice, only sera from mice vaccinated with naked DNA encoding Sm28GST contained IgG-specific anti-Sm28GST antibodies at 14 days postvaccination, and at 42 days the levels were suggestive of an anamnestic response. These results suggest that naked DNA vaccination of mice is capable of inducing both antigen-specific cell-mediated and humoral immune responses against Sm28GST and further strengthen the case for this antigen being a vaccine candidate.
Collapse
MESH Headings
- Animals
- Antibodies, Helminth/blood
- Antigens, Helminth/biosynthesis
- Antigens, Helminth/genetics
- Antigens, Helminth/immunology
- Baculoviridae/genetics
- DNA, Helminth/administration & dosage
- DNA, Helminth/immunology
- Enzyme-Linked Immunosorbent Assay
- Gene Expression Regulation, Viral
- Genetic Vectors
- Glutathione Transferase/biosynthesis
- Glutathione Transferase/genetics
- Glutathione Transferase/immunology
- Helminth Proteins
- Immunity, Cellular
- Injections, Intramuscular
- Mice
- Plasmids
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- Schistosoma mansoni/enzymology
- Schistosoma mansoni/genetics
- Schistosoma mansoni/immunology
- Schistosomiasis mansoni/prevention & control
- Vaccination/methods
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/immunology
Collapse
Affiliation(s)
- S G Kayes
- Department of Structural and Cellular Biology, College of Medicine, University of South Alabama, Mobile 36688-0002, USA
| | | | | | | |
Collapse
|
22
|
Abstract
BACKGROUND Microemboli occur commonly during cardiac surgery in adults, and, when present, increase the risk of neuropsychological deficits. Their incidence and significance during correction of congenital heart disease is unknown. The authors hypothesized that microemboli would occur before bypass with right-to-left cardiac shunts and would also occur in large numbers when the aortic crossclamp was released in children during repair of congenital heart defects. METHODS In 25 children studied with carotid artery Doppler, embolic signals were counted and timed in relation to 13 intraoperative events. Patients were classified as either at high risk (obligate right-to-left shunt or uncorrected transposition of the great arteries) or at low risk (net left-to-right shunt or simple obstructive lesions) for paradoxical (venous to arterial) emboli. RESULTS The median number of emboli detected was 122 (range, 2-2,664). Forty-two percent of all emboli were detected within 3 min of release of the aortic crossclamp. The high-risk group had significantly more emboli (median, 66; range, 0-116) during the time interval before cardiopulmonary bypass than did the low-risk group (median, 8; range, 0-73), with P < 0.01. There was no significant difference between the high- and low-risk groups in the total number of emboli detected. There was no apparent association between number of emboli and gross neurologic deficits. CONCLUSIONS Microemboli can be detected in the carotid arteries of children undergoing repair of congenital heart disease and are especially prevalent immediately after release of the aortic crossclamp. The role of emboli in causing neurologic injury in children undergoing repair of congenital heart disease remains to be determined.
Collapse
Affiliation(s)
- J J O'Brien
- Department of Anesthesiology, The Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina 27157-1009, USA.
| | | | | | | | | | | |
Collapse
|
23
|
O'Brien JJ. The discriminatory value of the blood nitrogen:creatinine ratio in localizing gastrointestinal bleeding. Am J Gastroenterol 1997; 92:1777. [PMID: 9382034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
24
|
Kachanov AA, Stoeckel F, Charvat AS, O'Brien JJ. Intracavity laser absorption measurements at ultrahigh spectral resolution. Appl Opt 1997; 36:4062-4068. [PMID: 18253427 DOI: 10.1364/ao.36.004062] [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: 05/25/2023]
Abstract
Intracavity laser absorption spectroscopy with ultrahigh sensitivity and enhanced spectral resolution is demonstrated. It entails use of an intracavity étalon that selects equally spaced modes of the cavity. These modes are reduced in intensity when they occur at spectral locations where absorption that is due to intracavity species also occurs. We obtained absorption spectra by tuning the étalon in small steps across its free spectral range, recording intracavity spectra at each step, and summing the result. The maximum resolution is determined by the width of the étalon peaks, which was ~0.01 cm(-1). When the finesse of the étalon is increased, the resolution equal to the width of a single laser mode can be achieved. With this technique, spectra at Doppler-free resolution such as that required for studies of high vibrational-overtone transitions of molecules in supersonic jets are possible.
Collapse
|
25
|
O'Brien JJ, Glasgow A, Lydon P. Endoscopic balloon-assisted abdominoplasty. Plast Reconstr Surg 1997; 99:1462-3. [PMID: 9105380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
26
|
Abstract
Transesophageal echocardiography (TEE) is frequently used in the operating room to assess surgical repairs in children with congenital heart disease. Complications from the procedure are unusual, but the potential for TEE probe compression of normal and abnormal posterior vascular structures has been recognized. We report a case of TEE probe compression of an aberrant right subclavian artery in a patient undergoing repair of an atrioventricular septal defect.
Collapse
Affiliation(s)
- A S Bensky
- Department of Pediatrics, Bowman Gray School of Medicine, Winston-Salem, NC 27157-1009, USA
| | | | | |
Collapse
|
27
|
Abstract
To promote early recognition and treatment of neuroleptic-induced tardive dyskinesia we used our facility's pharmacy and appointment data bases to develop an automated reminder system that significantly improved physician monitoring of patients receiving antipsychotic drug therapy. The system prompts staff to perform regular examinations for abnormal involuntary movements and to review patients' consent to therapy with antipsychotic medication. The average prevalences in the 15 months after automated reminders began, in a population of over 800 patients, increased from 53% to 85% for an annually completed abnormal involuntary movement scale in medical records and from 38 to 74% for a statement of informed consent. Now, 45 months later, prevalences of both measures approaches 100%. The integrated design of the Department of Veterans Affairs computer system allowed linking pharmacy and appointment scheduling data and facilitated the project. The reminder system effectively promoted rapid, marked, and sustained change in physicians' documentation of antipsychotic drug therapy.
Collapse
Affiliation(s)
- K W Hammond
- Psychiatry Service, American Lake VA Medical Center, Tacoma, WA 98493-5000, USA
| | | | | | | | | |
Collapse
|
28
|
Müller D, O'Brien JJ. Shallow water waves on the rotating sphere. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1995; 51:4418-4431. [PMID: 9963155 DOI: 10.1103/physreve.51.4418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
29
|
Hammond KW, Snowden M, Adkins T, O'Brien JJ. Computerized TD reminders. Hosp Community Psychiatry 1994; 45:1043-4. [PMID: 7829045 DOI: 10.1176/ps.45.10.1043] [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] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
|
30
|
|
31
|
Abstract
Stent occlusion may occur as the result of bacterial adherence and biofilm formation. This occlusion may be prompted by the material or design of the stents. In this study, a bile perfusion model was used to compare the biofilm formation on various stent materials. The copolymer and the wire mesh stents demonstrated less biofilm formation than the traditional stent. The development of new polymers may prolong stent patency.
Collapse
Affiliation(s)
- B J Hoffman
- Division of Gastroenterology, Medical University of South Carolina, Charleston 29425
| | | | | | | | | |
Collapse
|
32
|
Plaut SM, Maxwell SA, Seng L, O'Brien JJ, Fairclough GF. Mental health services for medical students: perceptions of students, student affairs deans, and mental health providers. Acad Med 1993; 68:360-365. [PMID: 8484849 DOI: 10.1097/00001888-199305000-00019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
PURPOSE To examine (1) whether there is any consistency among medical schools in mental health services provided and (2) how these services are perceived by student affairs deans, mental health service providers, and the students themselves. METHOD Questionnaires were sent in October 1991 to the student affairs dean (or director), the individual responsible for student mental health services, and a student representative in each of the 126 U.S. and Canadian medical schools. Data were sought regarding personnel, individuals served, location, hours, administration, funding, confidentiality, administrative referrals, and respondents' suggestions for improvement. Possible differences among the three groups of respondents were tested by chi-square. RESULTS Responses were received from 75 student affairs deans, 53 mental health providers, and 30 students. There was much diversity among schools in services provided, especially in the areas of administration and funding. Although perceptions of the three respondent groups were often the same, they differed significantly in a number of areas. Suggestions for improvement of services involved funding, personnel, hours, confidentiality and privacy, specialty services, preventive and support programs, and visibility. The suggestion most frequently made by the students was for increased information and visibility. CONCLUSION The differences among schools coupled with the differing perceptions within schools indicate a need for a comprehensive consideration of what kinds of mental health services are needed and how they can best be made accessible to a diverse body of students experiencing a variety of academic and personal challenges.
Collapse
Affiliation(s)
- S M Plaut
- Office of Student Affairs, University of Maryland School of Medicine, Baltimore 21201
| | | | | | | | | |
Collapse
|
33
|
|
34
|
Abstract
It was shown that 10(4) cfu of a field isolate of Mycobacterium bovis caused illness in five experimentally infected calves; one of these died. One of three contact calves also became clinically infected. Considerable variation in the humoral response of the affected animals was demonstrated by ELISAs using purified protein derivative (PPD) and phosphatide antigens. The inoculation of antigens used in the comparative tuberculin skin test significantly enhanced the level of PPD antibodies in the affected animals whereas that of the apparently non-infected contact animals remained unchanged.
Collapse
Affiliation(s)
- J Hanna
- Dept. of Agriculture for Northern Ireland, Veterinary Research Laboratories, Belfast, UK
| | | | | |
Collapse
|
35
|
O'Brien JJ, Kumari SS, Skinner DM. Proteins of Crustacean Exoskeletons: I. Similarities and Differences among Proteins of the Four Exoskeletal Layers of Four Brachyurans. Biol Bull 1991; 181:427-441. [PMID: 29304681 DOI: 10.2307/1542363] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Most of the proteins extracted from exocuticle, endocuticle, and membranous layer of four species of anecdysial (intermolt) crabs (the Bermuda land crab Gecarcinus lateralis, the rock crab Cancer antennarius, the shield-backed kelp crab Pugettia producta, and the southern shield-backed kelp crab Taliepus nuttalli) were 31 kDa or smaller; proteins of similar Mr were common to all three layers. Proteins from the membranous layer were qualitatively indistinguishable in all four species. More proteins 31 kDa or smaller were similar in size and pI to proteins from other exoskeletal layers than were proteins larger than 31 kDa. Proteins extracted from the epicuticle of G. lateralis included a group of five ranging from 54 to 42 kDa that bound 45Ca++ in vitro. The group was not seen in other layers of the exoskeleton of G. lateralis or, with the exception of 44 and 42 kDa protein bands that were in the epicuticle of C. antennarius, in any layers of the exoskeletons of the other three species. During proecdysis, the membranous layer is completely degraded, and proteins 31 kDa or smaller are preferentially degraded from the exocuticle and endocuticle of the old exoskeleton of G. lateralis, which is cast as an exuvia at ecdysis. The relative amounts of proteins in extracts of epicuticle from (1) anecdysial exoskeletons and (2) exuviae were very similar, suggesting that there was little degradation of epicuticle during proecdysis. Some of the proteins of the three inner layers of the exoskeleton of G. lateralis have characteristics similar to those of flexible cuticles of insects; they have acidic pIs and they form "charge trains," i.e., proteins of the same size separated by differences in charge during isoelectric focusing.
Collapse
|
36
|
Abstract
The efficacy and safety of therapy with azathioprine/6-mercaptopurine was studied in 78 patients with Crohn's disease. Mean duration of therapy was 1.6 years; 52 patients were treated greater than or equal to 6 months. All patients were also on other antiinflammatory medications. Evaluations included self-assessment and physician's assessment of well-being, functional capacity, general clinical response, clinical activities indices (National Foundation for Ileitis and Colitis/International Organization for the Study of Inflammatory Bowel Disease and Harvey-Bradshaw), and achievement of specific therapeutic goals. General clinical condition improved in 70% of the patients. Median response time was 3 months. The average Harvey-Bradshaw score decreased 37% with therapy, and a decrease of greater than or equal to 30% occurred in 66% of the subjects. An overall 72% achievement rate for specified therapeutic goals included controlling refractory disease, 73%; corticosteroid "sparing," 76%; and lessening fistulization, 63%. Nine patients got worse despite therapy. Adverse effects requiring discontinuation of therapy occurred in 10%, whereas dosages were briefly lowered for mild side effects in another 10%. This study demonstrates the effectiveness and safety of azathioprine/6-mercaptopurine in the majority of selected patients with chronic, unremitting, or steroid-requiring Crohn's disease.
Collapse
Affiliation(s)
- J J O'Brien
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | | |
Collapse
|
37
|
Abstract
An analysis was carried out of available information from a series of experiments on the excretion of M. bovis from infected cattle. The analysis indicated that an inverse exponential relationship exists between 'dose' of organisms given and the delay before excretion commences. This relationship was represented mathematically. Available field data supported the relationship and indicated that in natural bovine tuberculosis excretion of M. bovis begins around 87 days after infection occurs. It is also suggested that the data supports the concept of single nuclei infections in cattle.
Collapse
Affiliation(s)
- S D Neill
- Bacteriology Department Veterinary Research Laboratories, Stormont, Belfast, UK
| | | | | |
Collapse
|
38
|
Kelly D, O'Brien JJ, McCracken KJ. Effect of creep feeding on the incidence, duration and severity of post-weaning diarrhoea in pigs. Res Vet Sci 1990; 49:223-8. [PMID: 2236922] [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: 12/30/2022]
Abstract
The effect of creep feeding on the response of pigs weaned at two or three weeks old to infection with an enteropathogenic strain of Escherichia coli (O149; K91[B], K88 a, c [L]) was studied in two separate experiments. Gastric intubation was adopted to regulate the intake of creep feed during the sucking period. Animals were given the enteropathogenic strain either before weaning or at weaning and the course and outcome of the infection followed bacteriologically and clinically. The response of the animals to the infection varied considerably in accord with recent reports of multiple phenotypes (to K88 +ve organisms) among pigs but consumption of creep feed before weaning did not significantly affect the prevalence, duration or severity of the diarrhoea induced experimentally by the organism. Hence reputed immunological responses mounted against dietary antigens did not predispose to or protect against this infection.
Collapse
Affiliation(s)
- D Kelly
- Department of Food and Agricultural Chemistry, Queen's University of Belfast
| | | | | |
Collapse
|
39
|
Scott WW, Fishman EK, Kuhlman JE, Caskey CI, O'Brien JJ, Walia GS, Bayless TM. Computed tomography evaluation of the sacroiliac joints in Crohn disease. Radiologic/clinical correlation. Skeletal Radiol 1990; 19:207-10. [PMID: 2333561 DOI: 10.1007/bf00204098] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Computed tomography (CT) was used in a prospective study of the sacroiliac joints in 86 patients with Crohn disease to determine the type and frequency of sacroiliac joint abnormalities present in this population. The CT findings were correlated with review of the clinical history in 64 patients. Computed tomography demonstrated changes of sacroiliitis in 29% of the study group. This high prevalence of sacroiliac joint abnormality was found even in those under 30 years of age. It exceeds the 11-19% previously reported from plain film examination, reflecting the greater sensitivity of CT. In the subgroup of 64 patients studied clinically, 19 (30%) had abnormal sacroiliac joints on CT, but only 2 (3%) reported symptoms related to the sacroiliac joints.
Collapse
Affiliation(s)
- W W Scott
- Russell H. Morgan Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | | | | | | | | | | | | |
Collapse
|
40
|
McIlroy SG, McCracken RM, Neill SD, O'Brien JJ. Control, prevention and eradication of Salmonella enteritidis infection in broiler and broiler breeder flocks. Vet Rec 1989; 125:545-8. [PMID: 2690452 DOI: 10.1136/vr.125.22.545] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [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: 01/02/2023]
Abstract
Salmonella enteritidis was identified by serological and bacteriological techniques in two clinically normal breeder flocks in an integrated broiler organisation in Northern Ireland. The organism was transmitted vertically to clinically affected progeny flocks. The infected breeder flocks were slaughtered and the infection throughout the organisation controlled and subsequently eradicated. A working group, consisting of the senior management of the broiler organisation and veterinary staff from the Veterinary Research Laboratories at Stormont, was formed to establish procedures to minimise the risk of the reintroduction of salmonella infection, by preventing vertical transmission from grandparent flocks, or lateral transmission from personnel, other animal species and fomites, or transmission through the feed. All feed was heated to a minimum of 70 degrees C for 12 minutes immediately before it was pelleted and subsequently transported to the flocks through a dedicated system of conveyor belts, bins and lorries. A comprehensive system for monitoring the efficacy of the preventive procedures was established and is now used throughout the poultry industry of Northern Ireland.
Collapse
Affiliation(s)
- S G McIlroy
- Department of Agriculture for Northern Ireland, Veterinary Research Laboratories, Belfast
| | | | | | | |
Collapse
|
41
|
Abstract
Dezocine is an analgesic agent with opioid agonist and antagonist activity. After parenteral administration of therapeutic doses it is approximately equipotent with morphine, and has proved at least as effective an analgesic as morphine, pethidine (meperidine) and butorphanol in moderate to severe postoperative pain. However, preliminary pharmacodynamic data indicate that the ceiling of analgesic activity of dezocine occurs at a higher level of analgesia than that of reference agonist/antagonist agents. Also, the drug exhibited a morphine-like degree of anaesthetic-sparing activity in animals. Although long term data are very limited, single doses of dezocine are well tolerated, with mild and transient sedation and gastrointestinal upset the principal adverse effects. As with some other agonist/antagonist analgesics, a 'ceiling' effect to dezocine-induced respiratory depression occurs with increasing dosage, beyond which further depression has not been observed. In single analgesic doses, however, dezocine is a slightly more potent respiratory depressant than morphine. Clinically important haemodynamic changes have not been observed with usual analgesic doses of dezocine. As an agonist/antagonist opioid, the dependence liability of dezocine would be expected to be lower than that of pure agonist opioids, but extended clinical use is required before more definitive conclusions can be drawn in this regard. Unlike older drugs of its type, dezocine produced opiate-like subjective effects and was identified as morphine-like by drug abusers. Thus, provided the promising conclusions of currently available clinical studies are confirmed with its wider use, dezocine should be a useful additional agent for the treatment of moderate to severe postoperative pain.
Collapse
Affiliation(s)
- J J O'Brien
- Adis Drug Information Services, Auckland, New Zealand
| | | |
Collapse
|
42
|
Hanna J, Neill SD, O'Brien JJ. Use of PPD and phosphatide antigens in an ELISA to detect the serological response in experimental bovine tuberculosis. Res Vet Sci 1989; 47:43-7. [PMID: 2672202] [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: 01/02/2023]
Abstract
Five calves from tuberculosis free herds were each inoculated intranasally with 10(6) viable organisms of a field isolate of Mycobacterium bovis. Four of the calves developed acute tuberculosis. ELISAs employing protein and phosphatide extracts of M bovis as antigens were used to monitor the humoral response of the infected calves. Fourteen days after infection there was a dramatic increase in the level of antibodies demonstrated by the phosphatide antigen. This increase coincided with the first appearance of signs of the disease. The results suggest that the phosphatide antigen may be of potential value in detecting a humoral response, if present, in cattle infected with M bovis. The tests employing the protein antigen demonstrated a humoral response in only one of the infected calves and emphasises the importance of antigen selection to detect antibodies in tuberculous animals.
Collapse
Affiliation(s)
- J Hanna
- Department of Agriculture, Veterinary Research Laboratories, Stormont, Belfast
| | | | | |
Collapse
|
43
|
Abstract
Five of a group of six calves were inoculated with Mycobacterium bovis. Two more uninoculated calves were introduced to the group 84 days later. All the inoculated calves were subsequently shown to be excreting M bovis in nasal mucus. The uninoculated calf in the initial group of six became infected and subsequently excreted M bovis. The two uninoculated calves which were introduced later did not become infected. It was concluded that contact with nasal mucus from the infected cattle resulted in infection of the uninoculated calf and that the density of accommodation of animals excreting M bovis was an important factor in transmission of the disease.
Collapse
Affiliation(s)
- S D Neill
- Veterinary Research Laboratories, Belfast
| | | | | | | |
Collapse
|
44
|
Abstract
Acyclovir (aciclovir) is a nucleoside antiviral drug with antiviral activity in vitro against members of the herpes group of DNA viruses. As an established treatment of herpes simplex infection, intravenous, oral and to a lesser extent topical formulations of acyclovir provide significant therapeutic benefit in genital herpes simplex and recurrent orofacial herpes simplex. The effect of acyclovir therapy is maximised by early initiation of treatment, especially in non-primary infection which tends to have a less protracted course than the primary episode. Long term prophylactic oral acyclovir, in patients with frequent episodes of genital herpes simplex, totally suppresses recurrences in the majority of subjects; as with other infections responding to acyclovir, viral latency is not eradicated and pretreatment frequencies of recurrence return after discontinuation of treatment. Caution should accompany the prophylactic use of acyclovir in the general population, due to the theoretical risk of the emergence of viral strains resistant to acyclovir and other agents whose mechanism of action is dependent on viral thymidine kinase. Intravenous acyclovir is the treatment of choice in biopsy-proven herpes simplex encephalitis in adults, and has also been successful in the treatment of disseminated herpes simplex in pregnancy and herpes neonatorium. Intravenous and oral acyclovir protect against dissemination and progression of varicella zoster virus infection, but do not protect against post-herpetic neuralgia. In immunocompromised patients, intravenous, oral and topical acyclovir shorten the clinical course of herpes simplex infections while prophylaxis with oral or intravenous dosage forms suppresses reactivation of infection during the period of drug administration. Ophthalmic application of 3% acyclovir ointment rapidly heals herpetic dendritic corneal ulcers and superficial herpetic keratitis. Thus, despite an inability to eradicate latent virus, acyclovir administered in therapeutic or prophylactic fashion is now the standard antiviral therapy in several manifestations of herpes simplex virus infection, and indeed represents a major advance in this regard. With the exception of varicella zoster virus infections, early optimism concerning the use of the drug in diseases due to other herpes viruses has generally not been supported in clinical investigations.
Collapse
Affiliation(s)
- J J O'Brien
- ADIS Drug Information Services, Auckland, New Zealand
| | | |
Collapse
|
45
|
Abstract
Three groups, each of five calves, four to seven months old, were inoculated intranasally with different numbers of Mycobacterium bovis. Infection was established readily in the calves which received an inoculum containing either 10(6) or 10(4) colony forming units (cfu). After every infection there was a lag period during which the organisms could not be isolated from specimens of nasal mucus. All the animals excreted M bovis and the time of commencement, quantity and duration of excretion appeared to be related to the inoculation dose. Excretion continued for many weeks, and for two calves excretion became intermittent over many months. All the calves which were given inocula of 92 cfu failed to develop the disease and no immunological responses were detected; however, M bovis was isolated from nasal secretions from one of these animals 100 days after inoculation.
Collapse
Affiliation(s)
- S D Neill
- Veterinary Research Laboratories, Stormont, Belfast
| | | | | | | |
Collapse
|
46
|
Marcinik EJ, Hodgdon JA, O'Brien JJ. Survey of physical training facilities and programs on board Navy vessels. Navy Med 1988; 79:10-3. [PMID: 3185834] [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: 01/04/2023]
|
47
|
Abstract
Twenty-five of 50 randomly selected tuberculin-reacting cattle were confirmed as tuberculous in the laboratory. All 25 cattle had macroscopic lesions in lymph nodes associated with the respiratory tracts but only one had lung lesions. M bovis was isolated from the anterior respiratory tracts in the heads of four of the 25 tuberculous animals and from a nostril lesion found in a fifth. For at least three of these five animals, the intervals between the final tuberculin test and their previously negative tests indicated that infection had established relatively rapidly. Four of them had been tuberculin tested solely because they were animals in contiguous 'at risk' herds. It would appear that although M bovis can be isolated from the anterior respiratory tracts in the heads of tuberculin-reacting cattle, it is unlikely that primary foci of infection exist in regions other than the lungs or associated tissues. The study demonstrates the potential for reactors with lesions to excrete M bovis and the continued importance of infected cattle in the epidemiology and eradication of the disease.
Collapse
Affiliation(s)
- S D Neill
- Veterinary Research Laboratories, Stormont, Belfast
| | | | | |
Collapse
|
48
|
O'Brien JJ, Torruellas W, Goldstein N, Atkinson GH. Intracavity laser spectroscopy: propagation of absorption data through optical fibers. Appl Opt 1987; 26:4563-4569. [PMID: 20523403 DOI: 10.1364/ao.26.004563] [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: 05/29/2023]
Abstract
The propagation of achromatic visible laser radiation through optical fibers is examined for a quasi-cw dye laser designed to record absorption by intracavity laser spectroscopy (ILS). The wavelength and intensity characteristics of the ILS laser output and any superimposed intracavity absorption features are preserved quantitatively for propagation through an extracavity single-mode optical fiber. Feedback from the front surface of the optical fiber and its associated optics can modify the ILS laser output. Two optical configurations which give no noticeable modifications to the IS data propagated through the optical fiber are described. Applications of ILS for remote sensing, sensitive detection of extracavity feedback effects, and characterization of extracavity interferometric signals are indicated.
Collapse
|
49
|
Marcinik J, Hodgdon JA, O'Brien JJ. A comparison of sprain and strain injury rates during aerobic/calisthenic and aerobic/circuit weight training programs. Mil Med 1987; 152:252-4. [PMID: 3108720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
|
50
|
Marcinik EJ, Hodgdon JA, Englund CE, O'Brien JJ. Changes in fitness and shipboard task performance following circuit weight training programs featuring continuous or interval running. Eur J Appl Physiol Occup Physiol 1987; 56:132-7. [PMID: 3569217 DOI: 10.1007/bf00640635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Pre- and post-physiological data were collected on 57 Navy men (mean age = 19.5 years) who participated in either circuit weight training/continuous run (CWT/CR) (N = 31) or circuit weight training/interval run (CWT/IR) (N = 26) programs. Measured variables included 4 measures of upper torso dynamic strength (one repetition maximum [1 RM] for arm curl, bench press, shoulder press, and lat pull-down); two measures of lower torso dynamic strength (1 RM) for knee extension and leg press); one measure of power (number of revolutions completed on an arm ergometer (Monark) at maximum drag); three measures of muscular endurance (number of repetitions at 60% 1 RM for bench press and leg press and maximal number of bent-knee sit-ups in 120 s); one stamina measure (time to exhaustion on a cycle ergometer (Monark) maximal work capacity [MWC] test; and three simulated shipboard tasks: manikin shoulder drag, open/secure a water tight door and paint bucket carry. Composite shipboard performance derived from the summed time (s) required to complete the three tasks was also calculated. Results show performance on the manikin shoulder drag and majority of evaluative fitness measures was significantly (p less than 0.05) enhanced following both circuit weight training/run formats. Significantly (p less than 0.05) higher values for shoulder press (F = 7.2), arm ergometer (F = 5.3), and sit-ups (F = 6.8) and lower values for leg press muscular endurance (F = 5.1) were observed in CWT/IR when compared to CWT/CR.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|