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Wilcox AAE, Provencher JF, Henri DA, Alexander SM, Taylor JJ, Cooke SJ, Thomas PJ, Johnson LR. Braiding Indigenous knowledge systems and Western-based sciences in the Alberta oil sands region: A systematic review. Facets (Ott) 2023. [DOI: 10.1139/facets-2022-0052] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
The braiding of Indigenous knowledge systems and Western-based sciences offers insights into ecology and has emerged as a way to help address complex environmental issues. We reviewed the publicly available ecological research involving the braiding of Indigenous knowledge systems and Western-based sciences to support collaborative work in the Alberta oil sands region of Canada. We conducted a systematic review, coding for 78 questions in six categories: (1) literature search and bibliographic information; (2) research themes; (3) study setting and design; (4) knowledge systems; (5) power relationships, colonization, and ethical considerations in research; and (6) benefits and challenges of braiding. We identified six articles that braided knowledge, with those articles focusing on environmental management and monitoring for impacts of industrial activity in northern Alberta. Researchers used a broad range of approaches to gather Indigenous knowledge and scientific data and identified multiple challenges (e.g., asymmetries of power, resource availability, and funding) to research. Our findings show that more support is needed to foster, promote, and disseminate interdisciplinary collaborative work involving braiding. Additional support is also required to address Indigenous community research needs related to the assessment of environmental impact and reclamation, as well as the understanding of ecological threats across the region.
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Affiliation(s)
- Alana A. E. Wilcox
- Ecotoxicology and Wildlife Health Division, Science and Technology Branch, Environment and Climate Change, Ottawa, ON K1S 5B6, Canada
| | - Jennifer F. Provencher
- Ecotoxicology and Wildlife Health Division, Science and Technology Branch, Environment and Climate Change, Ottawa, ON K1S 5B6, Canada
| | - Dominique A. Henri
- Wildlife Research Division, Science and Technology Branch, Environment and Climate Change Canada, Montreal, QC H2Y 2E7, Canada
| | - Steven M. Alexander
- Environment and Biodiversity Sciences, Fisheries and Oceans Canada, Ottawa, ON K2P 2J8, Canada
- Environmental Change and Governance Group, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Jessica J. Taylor
- Canadian Centre for Evidence-Based Conservation, Institute of Environmental Sciences and Interdisciplinary Science, Carleton University, Ottawa, ON K1S 5B6, Canada
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Steven J. Cooke
- Canadian Centre for Evidence-Based Conservation, Institute of Environmental Sciences and Interdisciplinary Science, Carleton University, Ottawa, ON K1S 5B6, Canada
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Philippe J. Thomas
- Ecotoxicology and Wildlife Health Division, Science and Technology Branch, Environment and Climate Change, Ottawa, ON K1S 5B6, Canada
| | - Lydia R. Johnson
- School of Environmental Studies, Queen’s University, Kingston, ON K7L 3N6, Canada
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Manoj D, James RI, Delighta M, Johnson LR. Medicolegal autopsies in private medical colleges in India: An urgent need. J Postgrad Med 2022:362950. [PMID: 36511018 PMCID: PMC10394536 DOI: 10.4103/jpgm.jpgm_466_22] [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: 12/13/2022] Open
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Miazgowicz KL, Shocket MS, Ryan SJ, Villena OC, Hall RJ, Owen J, Adanlawo T, Balaji K, Johnson LR, Mordecai EA, Murdock CC. Age influences the thermal suitability of Plasmodium falciparum transmission in the Asian malaria vector Anopheles stephensi. Proc Biol Sci 2020; 287:20201093. [PMID: 32693720 PMCID: PMC7423674 DOI: 10.1098/rspb.2020.1093] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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] [Indexed: 12/27/2022] Open
Abstract
Models predicting disease transmission are vital tools for long-term planning of malaria reduction efforts, particularly for mitigating impacts of climate change. We compared temperature-dependent malaria transmission models when mosquito life-history traits were estimated from a truncated portion of the lifespan (a common practice) versus traits measured across the full lifespan. We conducted an experiment on adult female Anopheles stephensi, the Asian urban malaria mosquito, to generate daily per capita values for mortality, egg production and biting rate at six constant temperatures. Both temperature and age significantly affected trait values. Further, we found quantitative and qualitative differences between temperature-trait relationships estimated from truncated data versus observed lifetime values. Incorporating these temperature-trait relationships into an expression governing the thermal suitability of transmission, relative R0(T), resulted in minor differences in the breadth of suitable temperatures for Plasmodium falciparum transmission between the two models constructed from only An. stephensi trait data. However, we found a substantial increase in thermal niche breadth compared with a previously published model consisting of trait data from multiple Anopheles mosquito species. Overall, this work highlights the importance of considering how mosquito trait values vary with mosquito age and mosquito species when generating temperature-based suitability predictions of transmission.
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Affiliation(s)
- K L Miazgowicz
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA.,Center of Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
| | - M S Shocket
- Biology Department, Stanford University, Stanford, CA, USA.,Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
| | - S J Ryan
- Quantitative Disease Ecology and Conservation (QDEC) Lab, Department of Geography, University of Florida, Gainesville, FL, USA.,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.,School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - O C Villena
- Computational Modeling and Data Analytics, Department of Statistics, Virginia Tech, Blacksburg, VA, USA
| | - R J Hall
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center of Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA.,Odum School of Ecology, University of Georgia, Athens, GA, USA
| | - J Owen
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - T Adanlawo
- Odum School of Ecology, University of Georgia, Athens, GA, USA
| | - K Balaji
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - L R Johnson
- Computational Modeling and Data Analytics, Department of Statistics, Virginia Tech, Blacksburg, VA, USA
| | - E A Mordecai
- Biology Department, Stanford University, Stanford, CA, USA
| | - C C Murdock
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA.,Center of Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA.,Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for Vaccines and Immunology, University of Georgia, Athens, GA, USA.,River Basin Center, University of Georgia, Athens, GA, USA.,Department of Entomology, Cornell University, Ithaca, NY, USA
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Brown CS, Johnson LR, Visser LC, Chan JC, Pollard RE. Comparison of fluoroscopic cardiovascular measurements from healthy dogs obtained at end-diastole and end-systole. J Vet Cardiol 2020; 29:1-10. [PMID: 32348932 DOI: 10.1016/j.jvc.2020.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 04/05/2019] [Revised: 02/04/2020] [Accepted: 02/17/2020] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Quantitative measurements are commonly implemented to objectively evaluate heart size in dogs. However, recent studies suggest that the phase of cardiac cycle can impact vertebral heart score, thereby potentially influencing clinical management. This study used fluoroscopy to assess the impact of the cardiac cycle on quantitative cardiovascular measurements in healthy dogs of various breeds. ANIMALS, MATERIALS, AND METHODS This was a prospective study. Multiple cardiac and respiratory cycles were recorded fluoroscopically. Peak inspiratory end-systole and end-diastole frames were captured from 49 dogs in right lateral recumbency. Vertebral heart score (VHS), cardiothoracic ratio (CTR), vertebral left atrial size (VLAS), and caudal vena cava diameter ratio (CVCDR) measurements were performed. Mean cardiac measurements were compared between cardiac cycle phases, and the impact of body condition score (BCS), weight, thoracic conformation, sex, and age was evaluated. RESULTS Cardiac cycle had a significant impact on VHS (mean difference: 0.36 ± 0.14 vertebral units between systole and diastole; p < 0.001) and CTR (mean difference: 2.2 ± 1.2% between systole and diastole; p < 0.001). Cardiac cycle had no significant impact on VLAS or CVCDR. Increasing BCS significantly increased variation between systole and diastole in CTR measurements (p = 0.024). CONCLUSIONS The cardiac cycle has a significant effect on VHS and CTR but does not impact VLAS or CVCDR. These findings should be taken into consideration during clinical use of these measurements, especially if a patient is being monitored for cardiac changes over time via serial radiographs.
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Affiliation(s)
- C S Brown
- William R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, CA 95616, USA.
| | - L R Johnson
- William R. Pritchard Veterinary Medical Teaching Hospital, Department of Medicine and Epidemiology, University of California, Davis, CA 95616, USA
| | - L C Visser
- William R. Pritchard Veterinary Medical Teaching Hospital, Department of Medicine and Epidemiology, University of California, Davis, CA 95616, USA
| | - J C Chan
- William R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, CA 95616, USA
| | - R E Pollard
- William R. Pritchard Veterinary Medical Teaching Hospital, Department of Surgical and Radiological Sciences, University of California, Davis, CA 95616, USA
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El Moustaid F, Lane SJ, Moore IT, Johnson LR. A Mathematical Modeling Approach to the Cort-Fitness Hypothesis. Integr Org Biol 2019; 1:obz019. [PMID: 33791534 DOI: 10.1093/iob/obz019] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The Cort-Fitness Hypothesis has generated much interest from investigators integrating field endocrinology with evolutionary biology, ecology, and conservation. The hypothesis was developed to test the assumption that if glucocorticoid levels increase with environmental challenges and fitness decreases with environmental challenges, then there should be a negative relationship between baseline glucocorticoid levels and fitness. Indeed, studies across diverse taxa have found that the relationship between baseline glucocorticoid levels and fitness are not consistent: some studies show a positive relationship, others negative, and some show no correlation. Hence, a deeper understanding of the mechanisms underlying the relationship between baseline glucocorticoid levels, environmental challenges, and fitness is needed. We propose a mathematical model representing the links between baseline glucocorticoid levels, environmental challenges, and fitness. Our model describes how variation in the predictability and intensity of environmental challenges, reproductive strategies, and fitness metrics can all contribute to the variability observed in empirical tests of the Cort-Fitness Hypothesis. We provide qualitative results showing that much of the inconsistency in previous studies can be explained and we discuss how the model can be used to inform future Cort-Fitness studies.
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Affiliation(s)
- F El Moustaid
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.,Global Change Center, Virginia Tech, Blacksburg, VA 24061, USA
| | - S J Lane
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.,Global Change Center, Virginia Tech, Blacksburg, VA 24061, USA
| | - I T Moore
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.,Global Change Center, Virginia Tech, Blacksburg, VA 24061, USA
| | - L R Johnson
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.,Global Change Center, Virginia Tech, Blacksburg, VA 24061, USA.,Department of Statistics, Virginia Tech, Blacksburg, VA 24061, USA
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Chaaya N, Jacques A, Belmer A, Richard DJ, Bartlett SE, Battle AR, Johnson LR. Localization of Contextual and Context Removed Auditory Fear Memory within the Basolateral Amygdala Complex. Neuroscience 2018; 398:231-251. [PMID: 30552931 DOI: 10.1016/j.neuroscience.2018.12.004] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 01/20/2023]
Abstract
Debilitating and persistent fear memories can rapidly form in humans following exposure to traumatic events. Fear memories can also be generated and studied in animals via Pavlovian fear conditioning. The current study was designed to evaluate basolateral amygdala complex (BLC) involvement following the formation of different fear memories (two contextual fear memories and one adjusted auditory fear memory). Fear memories were created in the same context with five 1.0 mA (0.50 s) foot-shocks and, where necessary, five auditory tones (5 kHz, 75 dB, 20 s). The adjusted auditory fear conditioning protocol was employed to remove background contextual fear and produce isolated auditory fear memories. Immunofluorescent labeling was utilized to identify neurons expressing immediate early genes (IEGs). We found the two contextual fear conditioning (CFC) procedures to produce similar levels of fear-related freezing to context. Contextual fear memories produced increases in BLC IEG expression with distinct and separate patterns of expression. These data suggest contextual fear memories created in slightly altered contexts, can produce unique patterns of amygdala activation. The adjusted auditory fear conditioning procedure produced memories to a tone, but not to a context. This group, where no contextual fear was present, had a significant reduction in BLC IEG expression. These data suggest background contextual fear memories, created in standard auditory fear conditioning protocols, contribute significantly to increases in amygdala activation.
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Affiliation(s)
- N Chaaya
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia
| | - A Jacques
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia
| | - A Belmer
- Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia; School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - D J Richard
- Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia; School of Biomedical Science, Queensland University of Technology, Brisbane, Australia
| | - S E Bartlett
- Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia; School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - A R Battle
- Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia; School of Biomedical Science, Queensland University of Technology, Brisbane, Australia; The University of Queensland Diamantina Institute, Brisbane, QLD 4102, Australia
| | - L R Johnson
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia; Center for the Study of Traumatic Stress, Department of Psychiatry, USU School of Medicine, Bethesda, MD, USA.
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Chan JC, Johnson LR, Brown CS, Pollard RE. Fluoroscopic Estimation of Thoracic Dimensional Changes in Healthy Dogs. J Vet Intern Med 2017; 31:1841-1848. [PMID: 28961336 PMCID: PMC5697204 DOI: 10.1111/jvim.14825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 07/23/2017] [Accepted: 08/03/2017] [Indexed: 01/27/2023] Open
Abstract
Background Current methods available for assessing alterations in lung mechanics require sophisticated equipment and are of limited availability. A method that could assess lung area change with respiration might be a clinically useful surrogate for assessing lung compliance. Objective To use fluoroscopy to determine percent change in thoracic and lung areas in healthy dogs. Animals Forty‐four client‐owned dogs with no evidence of respiratory disease. Methods Prospective study. Resting respiration was recorded fluoroscopically, and peak inspiratory and expiratory frames were captured for 3 typical respiratory cycles. The number of intrathoracic pixels in the entire thoracic cavity was measured for both inspiration and expiration, and the average percent change in intrathoracic area was determined for each dog. This process was repeated by a hemithorax measurement of lung area that excluded the mediastinum and cardiac silhouette. Proposed reference ranges (and 95% confidence intervals [CI]) were computed by a nonparametric percentile distribution. Results Median percent change in thoracic dimension for the total thorax measurement was 12.5% (CI, 8.9–24.0%). Median percent change for the hemithorax measurement was significantly (P < 0.001) larger (20.8%, CI, 14.3–37.6%). Both measurement techniques were correlated with body weight but not with age, sex, thoracic conformation, body condition score (BCS), or breed. Conclusions and Clinical Importance Fluoroscopy allows a noninvasive and repeatable measure of lung area changes during respiration that must be corrected for body weight. Additional studies in dogs with respiratory diseases are needed to determine its utility in detecting clinically useful alterations in lung area changes.
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Affiliation(s)
- J C Chan
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California Davis, Davis, CA
| | - L R Johnson
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, CA
| | - C S Brown
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California Davis, Davis, CA
| | - R E Pollard
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, CA
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Greene LM, Royal KD, Bradley JM, Lascelles BDX, Johnson LR, Hawkins EC. Severity of Nasal Inflammatory Disease Questionnaire for Canine Idiopathic Rhinitis Control: Instrument Development and Initial Validity Evidence. J Vet Intern Med 2016; 31:134-141. [PMID: 28019044 PMCID: PMC5259640 DOI: 10.1111/jvim.14629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 10/04/2016] [Accepted: 11/08/2016] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Effective treatments are needed for idiopathic chronic rhinitis in dogs, but assessment of efficacy requires a practical, quantifiable method for assessing severity of disease. OBJECTIVES To develop and perform initial validity and reliability testing of an owner-completed questionnaire for assessing clinical signs and dog and owner quality of life (QOL) in canine chronic rhinitis. ANIMALS Twenty-two dogs with histopathologically confirmed chronic rhinitis and 72 healthy dogs. METHODS In this prospective study, an online questionnaire was created based on literature review and feedback from veterinarians, veterinary internists with respiratory expertise, and owners of dogs with rhinitis. Owners of affected dogs completed the questionnaire twice, 1 week apart, to test reliability. Healthy dogs were assessed once. Data were analyzed using the Rasch Rating Scale Model, and results were interpreted using Messick's framework for evaluating construct validity evidence. RESULTS Initial item generation resulted in 5 domains: nasal signs, paranasal signs, global rhinitis severity, and dog's and owner's QOL. A 25-item questionnaire was developed using 5-point Likert-type scales. No respondent found the questionnaire difficult to complete. Strong psychometric evidence was available to support the substantive, generalizability, content, and structural aspects of construct validity. Statistical differences were found between responses for affected and control dogs for all but 2 items. These items were eliminated, resulting in the 23-item Severity of Nasal Inflammatory Disease (SNIFLD) questionnaire. CONCLUSIONS AND CLINICAL IMPORTANCE The SNIFLD questionnaire provides a mechanism for repeated assessments of disease severity in dogs with chronic rhinitis.
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Affiliation(s)
- L M Greene
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - K D Royal
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - J M Bradley
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - B D X Lascelles
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - L R Johnson
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA
| | - E C Hawkins
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
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Taylor A, Peters I, Dhand NK, Whitney J, Johnson LR, Beatty JA, Barrs VR. Evaluation of Serum Aspergillus-Specific Immunoglobulin A by Indirect ELISA for Diagnosis of Feline Upper Respiratory Tract Aspergillosis. J Vet Intern Med 2016; 30:1708-1714. [PMID: 27581099 PMCID: PMC5032860 DOI: 10.1111/jvim.14567] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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: 12/08/2015] [Revised: 07/12/2016] [Accepted: 07/21/2016] [Indexed: 12/12/2022] Open
Abstract
Background Serological tests for diagnosis of aspergillosis in immunocompetent humans and animals are based on Aspergillus‐specific IgG (As‐IgG). In humans with chronic pulmonary aspergillosis, As‐IgA may be detectable even if IgG titers are negative. Cats with upper respiratory tract aspergillosis (URTA) have detectable As‐IgG, but their ability to mount an IgA response and its diagnostic utility are unknown. Objectives To determine whether serum As‐IgA can be detected in cats with URTA and evaluate its diagnostic utility alone or combined with As‐IgG. Animals Twenty‐three cats with URTA (Group 1), 32 cats with other respiratory diseases (Group 2), and 84 nonrespiratory controls (Group 3). Methods Serum As‐IgA and As‐IgG was measured by indirect ELISA. Optimal cutoff values were determined by receiver‐operating curve analysis. Sensitivity (Se) and specificity (Sp) for URTA diagnosis were determined. Results Serum IgA was detected in 91.3% of Group 1 cats. The Se of IgA detection was 78.3% and Sp was 96.9% for Group 2, 85.7% for Group 3 and 88.8% for Group 2 and 3 combined. Assay Se for IgG was 100% and Sp was 92.2%. Using combined IgA and IgG results at cutoffs optimized for Sp for IgA and Se for IgG and combined controls (Groups 2 and 3), Se for diagnosis was 100% and Sp was 91.4%. Conclusion and Clinical Importance Most cats with URTA have serum As‐IgA antibodies that can be detected by ELISA. Paired measurement of serum As‐IgA and IgG shows no benefit for diagnosis of feline URTA over IgG alone.
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Affiliation(s)
- A Taylor
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia
| | - I Peters
- TDDS ltd., The Innovation Centre, University of Exeter, Devon, UK
| | - N K Dhand
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia
| | - J Whitney
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia
| | - L R Johnson
- School of Veterinary Medicine, University of California, Davis, CA
| | - J A Beatty
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia
| | - V R Barrs
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia.
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Visser LC, Im MK, Johnson LR, Stern JA. Diagnostic Value of Right Pulmonary Artery Distensibility Index in Dogs with Pulmonary Hypertension: Comparison with Doppler Echocardiographic Estimates of Pulmonary Arterial Pressure. J Vet Intern Med 2016; 30:543-52. [PMID: 26893108 PMCID: PMC4913611 DOI: 10.1111/jvim.13911] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [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: 07/14/2015] [Revised: 12/01/2015] [Accepted: 01/28/2016] [Indexed: 11/28/2022] Open
Abstract
Background Noninvasive diagnosis of pulmonary hypertension (PH) primarily relies upon Doppler echocardiography of tricuspid regurgitation (TR). However, TR might be absent or difficult to measure. Hypothesis/Objectives To determine the diagnostic value of right pulmonary artery distensibility (RPAD) index for prediction of Doppler‐derived estimates of pulmonary artery (PA) pressure compared to other indices of PH in dogs. Animals Sixty‐nine client‐owned dogs with TR. Methods Prospective observational study. Dogs were allocated to groups according to TR pressure gradient (TRPG): TRPG <36 mmHg (control, n = 22), TRPG 36–50 (n = 16), TRPG 50–75 (n = 14) and TRPG >75 mmHg (n = 17). Right pulmonary artery distensibility index, acceleration time to peak PA flow (AT), AT: ejection time of PA flow (AT:ET) and main PA size: aorta size (MPA:Ao) were calculated in each dog. Results Right pulmonary artery distensibility index demonstrated the strongest correlation (r = −0.90; P < .0001) to TRPG followed by MPA:Ao (r = 0.78; P < .0001), AT (r = −0.69; P < .0001) and AT:ET (r = −0.68; P < .0001). RPAD index possessed the most accurate cutoff (<29.5%; Sensitivity [Sn] 0.84, Specificity [Sp] 0.95) to predict TRPG >50 mmHg compared to AT (<53.9 ms; Sn 0.74, Sp 0.87), AT:ET (<0.30; Sn 0.61, Sp 0.97) and MPA:Ao (>1.04; Sn 0.94, Sp 0.74). All intra‐ and interobserver measurement variabilities exhibited coefficients of variation ≤13%. Conclusions and Clinical Importance Right pulmonary artery distensibility index is an accurate predictor of TRPG and should be particularly useful if TR is absent or difficult to measure.
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Affiliation(s)
- L C Visser
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA
| | - M K Im
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA
| | - L R Johnson
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA
| | - J A Stern
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA
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Johnson LR, Johnson EG, Vernau W, Kass PH, Byrne BA. Bronchoscopy, Imaging, and Concurrent Diseases in Dogs with Bronchiectasis: (2003-2014). J Vet Intern Med 2015; 30:247-54. [PMID: 26682874 PMCID: PMC4913641 DOI: 10.1111/jvim.13809] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 10/18/2015] [Accepted: 11/11/2015] [Indexed: 12/16/2022] Open
Abstract
Background Bronchiectasis is a permanent and debilitating sequel to chronic or severe airway injury, however, diseases associated with this condition are poorly defined. Objective To evaluate results of diagnostic tests used to document bronchiectasis and to characterize underlying or concurrent disease processes. Animals Eighty‐six dogs that had bronchoscopy performed and a diagnosis of bronchiectasis. Methods Retrospective case series. Radiographs, computed tomography, and bronchoscopic findings were evaluated for features of bronchiectasis. Clinical diagnoses of pneumonia (aspiration, interstitial, foreign body, other), eosinophilic bronchopneumopathy (EBP), and inflammatory airway disease (IAD) were made based on results of history, physical examination, and diagnostic testing, including bronchoalveolar lavage fluid analysis and microbiology. Results Bronchiectasis was diagnosed in 14% of dogs (86/621) that had bronchoscopy performed. Dogs ranged in age from 0.5 to 14 years with duration of signs from 3 days to 10 years. Bronchiectasis was documented during bronchoscopy in 79/86 dogs (92%), thoracic radiology in 50/83 dogs (60%), and CT in 34/34 dogs (100%). Concurrent airway collapse was detected during bronchoscopy in 50/86 dogs (58%), and focal or multifocal mucus plugging of segmental or subsegmental bronchi was found in 41/86 dogs (48%). Final diagnoses included pneumonia (45/86 dogs, 52%), EBP (10/86 dogs, 12%) and IAD (31/86 dogs, 36%). Bacteria were isolated in 24/86 cases (28%), with Streptococcus spp, Pasteurella spp, enteric organisms, and Stenotrophomonas isolated most frequently. Conclusions and Clinical Importance Bronchiectasis can be anticipated in dogs with infectious or inflammatory respiratory disease. Advanced imaging and bronchoscopy are useful in making the diagnosis and identifying concurrent respiratory disease.
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Affiliation(s)
- L R Johnson
- Department of Medicine and Epidemiology, University of California, Davis, Davis, CA
| | - E G Johnson
- Department of Surgical and Radiological Science, University of California, Davis, Davis, CA
| | - W Vernau
- Department of Pathology, Microbiology, and Immunology, University of California, Davis, Davis, CA
| | - P H Kass
- Department of Population Health and Reproduction, University of California, Davis, Davis, CA
| | - B A Byrne
- Department of Pathology, Microbiology, and Immunology, University of California, Davis, Davis, CA
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Zhu BY, Johnson LR, Vernau W. Tracheobronchial brush cytology and bronchoalveolar lavage in dogs and cats with chronic cough: 45 cases (2012-2014). J Vet Intern Med 2015; 29:526-32. [PMID: 25818208 PMCID: PMC4895494 DOI: 10.1111/jvim.12566] [Citation(s) in RCA: 11] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 12/18/2014] [Accepted: 01/29/2015] [Indexed: 11/29/2022] Open
Abstract
Background Animals with chronic cough can have normal bronchoalveolar lavage fluid cytology when small airway disease is absent. Cytology of a tracheobronchial brushing can detect inflammation in larger airways; however, evaluation of this technique has been limited in veterinary medicine. Objective To compare airway brush cytology to bronchoalveolar lavage fluid analysis in dogs and cats with chronic cough. Animals Forty dogs and five cats undergoing bronchoscopic investigation of chronic cough. Methods Prospective study. Bronchoscopy and bronchoalveolar lavage were performed followed by tracheobronchial brushing of central airways. Results of cytologic assessment of BAL fluid and brush cytology were compared for the presence or absence of inflammation and concordance of inflammatory cell type. Results Brush cytology detected central airway inflammation in 34 of 40 (85%) dogs with inflammatory BAL fluid. However, the type of inflammation reported differed in 23 of 34 dogs. In five cats with inflammation in BAL fluid, brush cytology detected inflammation in four; the type of inflammation was discordant in all cats. Conclusions and clinical relevance Brush cytology has good agreement with BAL regarding the presence of inflammation, although the type of inflammation detected with the different sampling techniques commonly varies. Brush cytology can provide supplementary information to BAL, and additional studies will provide further information on the role of tracheobronchial brush cytology in the diagnosis and management of respiratory conditions.
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Affiliation(s)
- B Y Zhu
- William R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, CA
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13
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Johnson LR, Singh MK, Pollard RE. Agreement Among Radiographs, Fluoroscopy and Bronchoscopy in Documentation of Airway Collapse in Dogs. J Vet Intern Med 2015; 29:1619-26. [PMID: 26365563 PMCID: PMC4895679 DOI: 10.1111/jvim.13612] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [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: 01/30/2015] [Revised: 06/04/2015] [Accepted: 08/03/2015] [Indexed: 12/01/2022] Open
Abstract
Background Airway collapse is a common finding in dogs with chronic cough, yet the diagnosis can be difficult to confirm without specialty equipment. Hypothesis Bronchoscopic documentation of tracheobronchial collapse will show better agreement with fluoroscopic imaging than with standard radiography. Animals Forty‐two dogs prospectively evaluated for chronic cough. Methods In this prospective study, three‐view thoracic radiographs were obtained followed by fluoroscopy during tidal respiration and fluoroscopy during induction of cough. Digital images were assessed for the presence or absence of collapse at the trachea and each lobar bronchus. Bronchoscopy was performed under general anesthesia for identification of tracheobronchial collapse at each lung segment. Agreement of imaging tests with bronchoscopy was evaluated along with sensitivity and specificity of imaging modalities as compared to bronchoscopy. Results Airway collapse was identified in 41/42 dogs via 1 or more testing modalities. Percent agreement between pairs of tests varied between 49 and 87% with poor–moderate agreement at most bronchial sites. Sensitivity for the detection of bronchoscopically identified collapse was highest for radiography at the trachea, left lobar bronchi, and the right middle bronchus, although specificity was relatively low. Detection of airway collapse was increased when fluoroscopy was performed after induction of cough compared to during tidal respiration. Conclusions Radiography and fluoroscopy are complementary imaging techniques useful in the documentation of bronchial collapse in dogs. Confirming the presence or absence of tracheal or bronchial collapse can require multiple imaging modalities as well as bronchoscopy.
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Affiliation(s)
- L R Johnson
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, CA
| | - M K Singh
- Small Animal Specialist Hospital, North Ryde, NSW, Australia
| | - R E Pollard
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA
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14
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Abstract
Gastric lavage is a routine procedure done in many cases of poisoning and it has been advocated by many as a lifesaving procedure. There may be some instances, where it might be unnecessary, ineffective or even detrimental to life. A 35 year old man walked into a casualty, 2 hours after having ingested 15 benzodiazepine tablets. Lavage was done by an unqualified person using Ewald's tube, leading to iatrogenic perforation. The unwarranted use of the procedure proved to be fatal.
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Affiliation(s)
- M D Nithin
- Department of Forensic Medicine and Toxicology J.S.S University, J.S.S.Medical College. Sri Shivarathreeshwara Nagar Bannimantap, Mysore - 570015, Karnataka, India
| | - R M Marigoudar
- Department of Forensic Medicine and Toxicology J.S.S University, J.S.S.Medical College. Sri Shivarathreeshwara Nagar Bannimantap, Mysore - 570015, Karnataka, India
| | - S Rani
- Department of Forensic Medicine and Toxicology J.S.S University, J.S.S.Medical College. Sri Shivarathreeshwara Nagar Bannimantap, Mysore - 570015, Karnataka, India
| | - L R Johnson
- Department of Forensic Medicine and Toxicology J.S.S University, J.S.S.Medical College. Sri Shivarathreeshwara Nagar Bannimantap, Mysore - 570015, Karnataka, India
| | - M Chakrapani
- Department of Forensic Medicine and Toxicology J.S.S University, J.S.S.Medical College. Sri Shivarathreeshwara Nagar Bannimantap, Mysore - 570015, Karnataka, India
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15
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Barrs VR, Ujvari B, Dhand NK, Peters IR, Talbot J, Johnson LR, Billen F, Martin P, Beatty JA, Belov K. Detection of Aspergillus-specific antibodies by agar gel double immunodiffusion and IgG ELISA in feline upper respiratory tract aspergillosis. Vet J 2014; 203:285-9. [PMID: 25634077 DOI: 10.1016/j.tvjl.2014.12.020] [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: 07/01/2014] [Revised: 11/30/2014] [Accepted: 12/21/2014] [Indexed: 12/14/2022]
Abstract
Feline upper respiratory tract aspergillosis (URTA) is an emerging infectious disease. The aims of this study were: (1) to assess the diagnostic value of detection of Aspergillus-specific antibodies using an agar gel double immunodiffusion (AGID) assay and an indirect immunoglobulin G (IgG) ELISA; and (2) to determine if an aspergillin derived from mycelia of Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus can be used to detect serum antibodies against cryptic Aspergillus spp. in Aspergillus section Fumigati. Sera from cats with URTA (group 1: n = 21) and two control groups (group 2: cats with other upper respiratory tract diseases, n = 25; group 3: healthy cats and cats with non-respiratory, non-fungal illness, n = 84) were tested. Isolates from cats with URTA comprised A. fumigatus (n = 5), A. flavus (n = 1) and four cryptic species: Aspergillus felis (n = 12), Aspergillus thermomutatus (Neosartorya pseudofischeri, n = 1), Aspergillus lentulus (n = 1) and Aspergillus udagawae (n = 1). Brachycephalic purebred cats were significantly more likely to develop URTA than other breeds (P = 0.013). The sensitivity (Se) of the AGID was 43% and the specificity (Sp) was 100%. At a cut-off value of 6 ELISA units/mL, the Se of the IgG ELISA was 95.2% and the Sp was 92% and 92.9% for groups 2 and 3 cats, respectively. Aspergillus-specific antibodies against all four cryptic species were detected in one or both assays. Assay Se was not associated with species identity. Detection of Aspergillus-specific antibodies by IgG ELISA has high Se and Sp for diagnosis of feline URTA.
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Affiliation(s)
- V R Barrs
- Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia.
| | - B Ujvari
- Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia
| | - N K Dhand
- Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia
| | - I R Peters
- TDDS, Innovation Centre, University of Exeter, Devon, UK
| | - J Talbot
- Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia
| | - L R Johnson
- School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - F Billen
- Faculty of Veterinary Medicine, University of Liege, Belgium
| | - P Martin
- Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia
| | - J A Beatty
- Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia
| | - K Belov
- Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia
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16
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Johnson LR, Mayhew PD, Steffey MA, Hunt GB, Carr AH, McKiernan BC. Upper airway obstruction in Norwich Terriers: 16 cases. J Vet Intern Med 2013; 27:1409-15. [PMID: 24112556 DOI: 10.1111/jvim.12206] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [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: 04/17/2013] [Revised: 08/04/2013] [Accepted: 08/21/2013] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Norwich Terriers have grown increasingly popular as show animals and pets, and awareness of respiratory problems within the breed is growing. OBJECTIVE To describe components of obstructive upper airway syndrome in a nonbrachycephalic terrier breed. ANIMALS Sixteen Norwich Terriers; 12 with and 4 without clinical signs of respiratory disease. METHODS Prospective case series. Physical and laryngoscopic examinations were performed by 1 investigator in all dogs. Medical and surgical interventions were summarized and results of follow-up examination or owner reports were recorded. RESULTS The study population was comprised of 9 females (6 intact) and 7 males (5 intact). Median age was 3.0 years (range, 0.5-11 years). Of 12 dogs presented for a respiratory complaint, physical examination was normal in 4 dogs. Laryngoscopic examination was abnormal in 11/12 dogs with redundant supra-arytenoid folds, laryngeal collapse, everted laryngeal saccules, and a narrowed laryngeal opening in most. Of 4 dogs lacking clinical signs, all had normal physical examination; however, 3/4 dogs had similar appearance of the larynx to dogs with clinical signs. Response to surgical intervention was minimal to moderate in all dogs. CONCLUSIONS AND CLINICAL IMPORTANCE Norwich Terriers suffer from an upper airway obstructive syndrome that differs from that encountered in brachycephalic breeds. Affected dogs are difficult to identify without laryngoscopic examination because of the lack of clinical signs and abnormalities in physical examination findings, despite severe airway obstruction. Care is warranted when anesthetizing Norwich Terriers because of the small size of the laryngeal opening.
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Affiliation(s)
- L R Johnson
- Department of Medicine and Epidemiology, University of California, Davis, Davis, CA
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17
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Gould EN, Johnson LR, Traslavina RP, Mohr FC. Neuroendocrine tumour at the carina of a dog. J Comp Pathol 2013; 149:233-6. [PMID: 23582972 DOI: 10.1016/j.jcpa.2013.01.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [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: 10/19/2012] [Revised: 11/28/2012] [Accepted: 01/25/2013] [Indexed: 10/26/2022]
Abstract
A 10-year-old, neutered female, crossbred pit bull terrier was presented for cough, haemoptysis and rapidly progressive respiratory difficulty. Thoracic radiographs suggested a soft tissue density at the carina and bronchoscopy revealed a large, broad-based mass obstructing the entire left mainstem bronchus and half of the entrance to the right mainstem bronchus. Microscopically, the mass consisted of neoplastic cells that were packeted into small nests and had strong granular cytoplasmic immunoreactivity to synaptophysin and chromogranin A. Cytoplasmic neurosecretory granules stained strongly by the Grimelius method. A diagnosis of obstructive neuroendocrine tumour was made.
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Affiliation(s)
- E N Gould
- William R. Pritchard Veterinary Medical Teaching Hospital, University of California at Davis, Davis, CA, USA
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18
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Ybarra WL, Johnson LR, Drazenovich TL, Johnson EG, Vernau W. Interpretation of multisegment bronchoalveolar lavage in cats (1/2001-1/2011). J Vet Intern Med 2012; 26:1281-7. [PMID: 23106475 DOI: 10.1111/j.1939-1676.2012.01016.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 08/20/2012] [Accepted: 09/05/2012] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Cytologic results from bronchoscopic BAL in cats with naturally occurring respiratory disease have not been reported, and the clinical utility of multisegment lavage has not been evaluated. HYPOTHESIS BAL cytology from 2 separate lung segments in cats will have similar cell counts, cytologic interpretation, or both. ANIMALS Eighty-seven cases in 85 cats (2 examined twice) with naturally occurring lower respiratory disease. METHODS A combined prospective/retrospective evaluation of all cats with multisegment BAL was performed. BAL fluid was evaluated for total nucleated cell counts, differential cell counts, and cytologic characteristics at each lavage site. BAL fluid was categorized as eosinophilic, neutrophilic, lymphocytic, hypercellular, or mixed. Radiographs were assessed for diffuse or focal disease. RESULTS Clinical diagnoses included inflammatory airway disease (n = 63), pneumonia (n = 15), neoplasia (n = 6), and undetermined (n = 3). Total nucleated cell counts varied between sites regardless of radiographic evidence of focal or diffuse radiographic disease. In 28/87 cases (32%), cell counts differed between lavage sites by 2.2-40 fold. BAL yielded similar cytologic interpretation of inflammation in 45/87 (52%) cases. In 8/14 cases that had BAL performed at the site of a focal radiographic infiltrate, as well as at a site of diffuse infiltrates, the same inflammatory interpretation was made at each site. CONCLUSIONS AND CLINICAL IMPORTANCE Total and differential cell counts in BAL fluid often differ between lung segments in cats with lower respiratory disease, and caution is warranted when using a single BAL cytology to define the inflammatory response in cats with spontaneously occurring lower respiratory tract disease.
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Affiliation(s)
- W L Ybarra
- William R. Pritchard Veterinary Medical Teaching Hospital, Davis, CA, USA
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19
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Abstract
The vertebral heart score (VHS) measurement is commonly used to provide a more objective measurement of cardiomegaly in canines. However, several studies have shown significant breed variations from the value previously established by Buchanan and Bücheler (9.7 ± 0.5). This study describes VHS measurements in Pug, Pomeranian, Yorkshire Terrier, Dachshund, Bulldog, Shih Tzu, Lhasa Apso, and Boston Terrier dog breeds. Dogs with two or three view thoracic radiographs, no subjective radiographic evidence of cardiomegaly, and no physical examination findings of heart murmurs or gallop rhythms were included in the study. The Pug, Pomeranian, Bulldog, and Boston Terrier groups were found to have a VHS significantly greater than 9.7 ± 0.5 (P < 0.00001, P = 0.0014, P < 0.0001, P < 0.00001, respectively). Body condition score (BCS) was found to have a significant effect on the VHS of Lhasa Apso group. Anomalous vertebrae in the thoracic column were associated with a significant increase in VHS of the Bulldog (P = 0.028) and Boston Terrier (P = 0.0004) groups. Thoracic depth to width ratio did not have a significant effect on VHS.
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Affiliation(s)
- K Jepsen-Grant
- Veterinary Medical Teaching Hospital, University of California, Davis, CA, USA
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20
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Alman AC, Johnson LR, Calverley DC, Grunwald GK, Lezotte DC, Hokanson JE. Diagnostic capabilities of fractal dimension and mandibular cortical width to identify men and women with decreased bone mineral density. Osteoporos Int 2012; 23:1631-6. [PMID: 21633828 DOI: 10.1007/s00198-011-1678-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 03/30/2011] [Indexed: 10/18/2022]
Abstract
UNLABELLED Dental panoramic radiographs could be used to screen for osteopenia. We found the fractal dimension to be a good discriminator of osteopenia in both men and women but that the mandibular cortical width (MCW) did not perform as well in men. The fractal dimension may be a valid screening tool. INTRODUCTION The aim of this study was to assess the diagnostic capability of the fractal dimension and MCW measured from dental panoramic radiographs in identifying men and women with decreased bone mineral density (BMD). METHODS The MCW and fractal dimension were measured from dental panoramic radiographs as surrogates for BMD. These measures were then compared to the results from dual-energy X-ray absorptiometry (DXA) performed for clinical purposes. A total of 56 subjects with the panoramic radiograph taken within 6 months of the DXA exam were used in the analysis for this study. RESULTS The area under the curve of the fractal dimension for identifying low BMD (T-score <-1.0) was 0.81 (0.67, 0.95) and 0.78 (0.49, 1.00) for men and women, respectively. For the MCW, the area under the curve was found to be 0.53 (0.34, 0.72) and 0.80 (0.58, 1.00) for men and women, respectively. CONCLUSIONS In this largely male study population, the fractal dimension was found to be a good discriminator of low BMD in both men and women. The MCW did not perform as well in men.
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Affiliation(s)
- A C Alman
- Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Anschutz Medical Campus, MS F542, 13001 E 17th Ave, Aurora, CO 80045, USA.
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21
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Johnson LR, Sharp ZD, Galewsky J, Strong M, Van Pelt AD, Dong F, Noone D. Hydrogen isotope correction for laser instrument measurement bias at low water vapor concentration using conventional isotope analyses: application to measurements from Mauna Loa Observatory, Hawaii. Rapid Commun Mass Spectrom 2011; 25:608-616. [PMID: 21290447 DOI: 10.1002/rcm.4894] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The hydrogen and oxygen isotope ratios of water vapor can be measured with commercially available laser spectroscopy analyzers in real time. Operation of the laser systems in relatively dry air is difficult because measurements are non-linear as a function of humidity at low water concentrations. Here we use field-based sampling coupled with traditional mass spectrometry techniques for assessing linearity and calibrating laser spectroscopy systems at low water vapor concentrations. Air samples are collected in an evacuated 2 L glass flask and the water is separated from the non-condensable gases cryogenically. Approximately 2 µL of water are reduced to H(2) gas and measured on an isotope ratio mass spectrometer. In a field experiment at the Mauna Loa Observatory (MLO), we ran Picarro and Los Gatos Research (LGR) laser analyzers for a period of 25 days in addition to periodic sample collection in evacuated flasks. When the two laser systems are corrected to the flask data, they are strongly coincident over the entire 25 days. The δ(2)H values were found to change by over 200‰ over 2.5 min as the boundary layer elevation changed relative to MLO. The δ(2)H values ranged from -106 to -332‰, and the δ(18)O values (uncorrected) ranged from -12 to -50‰. Raw data from laser analyzers in environments with low water vapor concentrations can be normalized to the international V-SMOW scale by calibration to the flask data measured conventionally. Bias correction is especially critical for the accurate determination of deuterium excess in dry air.
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Affiliation(s)
- L R Johnson
- Department of Earth and Planetary Sciences, MSCO, University of New Mexico, Albuquerque, 87131-0001, USA.
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22
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Abstract
BACKGROUND Diagnosis of lower respiratory disease requires collection of airway samples to confirm the etiology of disease. Bronchoscopic evaluation is commonly performed in dogs but less information is available in cats. HYPOTHESIS The presence and number of bronchoscopic abnormalities visualized during bronchoscopic evaluation of cats with lower respiratory disease will correlate with the type of disease and total and differential cell counts in bronchoalveolar lavage (BAL) fluid. ANIMALS Forty-eight cats prospectively evaluated by a single bronchoscopist. METHODS Bronchoscopy was performed during clinical evaluation of cats presenting with cough, respiratory distress, or both. Cats were evaluated for airway hyperemia, stenosis, or collapse, mucus accumulation, bronchiectasis, and epithelial irregularities. Cats were placed into groups of bronchitis/"asthma," pneumonia, or neoplasia based on BAL findings, histopathology, and response to appropriate medical therapy. Summation of bronchial abnormalities and total and differential cell counts were compared among groups. RESULTS Endobronchial abnormalities were common in cats with feline bronchitis/asthma, pneumonia, and neoplasia and no differentiating features were found. Excessive mucus accumulation was common (83%), followed by stenosis of bronchial openings and nodular epithelial irregularities (56%), airway hyperemia (54%), airway collapse (48%), and bronchiectasis (27%). Total bronchoscopic score and total cell count did not differ among groups, although differential cell counts were significantly different. A weak correlation (R² = 0.16, P= .006) between age and total bronchoscopic score was noted. CONCLUSIONS AND CLINICAL RELEVANCE Bronchoscopic abnormalities are common in cats with lower respiratory tract disease, and visualization of the airways provides additional nonspecific clinical information in cats.
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Affiliation(s)
- L R Johnson
- Department of Medicine and Epidemiology, School of Veterinary Medicine, William R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, CA, USA.
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Bhattacharya S, Ray RM, Johnson LR. Decreased apoptosis in polyamine depleted IEC-6 cells depends on Akt-mediated NF-kappaB activation but not GSK3beta activity. Apoptosis 2007; 10:759-76. [PMID: 16133867 DOI: 10.1007/s10495-005-2943-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [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: 10/25/2022]
Abstract
The PI3-kinase/Akt pathway promotes cell survival in many different cell types including intestinal epithelial cells. Increased AKT activation in polyamine depleted intestinal epithelial cells correlated well with the decrease in TNF-alpha-induced apoptosis. Increased Akt activation and GSK3beta (Ser 9) phosphorylation without significant effect on Bad (Ser136) phosphorylation indicate that Akt-mediated protection is independent of Bad phosphorylation but may depend on GSK3beta. Pretreatment of polyamine-depleted cells with LY294002 increased caspase-9 and caspase-3 activation and decreased basal levels of GSK-3beta phosphorylation. Inhibition of GSK3beta activity using AR-A014418 or lithium chloride or siRNA-mediated downregulation of its expression had no effect on apoptosis. Inhibition of PI3-kinase and over-expression of dominant negative Akt (DN-AKT), significantly increased apoptosis in polyamine depleted cells. DN-Akt expression reversed the protective effect of polyamine depletion on apoptosis. DN-Akt, as well as the PI3-kinase inhibitors, prevented Akt activation and subsequent translocation of NF-kappaB to the nucleus. Constitutively active Akt (CA-AKT) expression increased resistance to TNF-alpha-induced apoptosis. Constitutively active-Akt expression increased nuclear staining of NF-kappaB. Moreover, polyamine depletion of DN-Akt cells prevented basal and TNF-alpha-induced IkappaBalpha phosphorylation. Prevention of NF-kappaB activation in DN-IkappaBalpha-transfected cells increased apoptosis in control cells and restored it in polyamine-depleted cells to control levels. These data indicate that Akt regulates the mitochondrial pathway, preventing activation of caspase-9 and thereby caspase-3 via NF-kappaB and these effects are independent of GSK-3beta activity.
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Affiliation(s)
- S Bhattacharya
- Department of Physiology, The University of Tennessee Health Science Center, 894 Union Ave., Memphis, Tennessee 38163, USA
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24
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Abstract
The rapid migration of intestinal epithelial cells (IEC) is important for the healing of mucosal wounds. We have previously shown that polyamine depletion inhibits migration of IEC-6 cells. Akt activation and its downstream target GSK-3beta have been implicated in the regulation of migration. Here we investigated the significance of elevated phosphatidylinositol 3-kinase (PI3K)/Akt signaling on migration of polyamine-depleted cells. Polyamine-depleted cells had high Akt (Ser473) and GSK-3beta (Ser9) phosphorylation. Pretreatment with 20 microM LY294002 (PI3K inhibitor) for 30 min inhibited phosphorylation of Akt, increased migration by activating Rac1 in polyamine-depleted IEC-6 cells, and restored the actin structure similar to that in cells grown in control medium. Treatment of cells with a GSK-3beta inhibitor (AR-A014418) altered the actin cytoskeleton and inhibited migration, mimicking the effects of polyamine depletion. Thus, our results indicate that sustained activation of Akt in response to polyamine depletion inhibits migration through GSK-3beta and Rac1.
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Affiliation(s)
- R J Vaidya
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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25
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Affiliation(s)
- L R Johnson
- The Department of Physiology, the University of Leeds
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26
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Jensen PD, Johnson LR, Trumble JT. Individual and joint actions of selenate and methylmercury on the development and survival of insect detritivore Megaselia scalaris (Diptera: Phoridae). Arch Environ Contam Toxicol 2006; 50:523-30. [PMID: 16418899 DOI: 10.1007/s00244-005-0111-y] [Citation(s) in RCA: 5] [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] [Received: 05/04/2005] [Accepted: 08/22/2005] [Indexed: 05/06/2023]
Abstract
Despite the important roles played by insects in most ecosystems, surprisingly little is known about how anthropogenic pollutants or their mixtures interact to affect insect populations. The independent and joint actions of selenate and methylmercury on a ubiquitous insect detritivore, Megaselia scalaris (Loew), were determined in this study. Ovipositing females did not distinguish between untreated food sources and those contaminated with toxic concentrations of selenate, methylmercury, or both chemicals in combination. Even at the highest concentrations of pollutants, no negative effects were observed for the egg stage. However, larval survival was significantly decreased and development significantly prolonged by selenate and methylmercury individually at low or intermediate ecologically relevant treatment levels. Potentiation was strongly evident because mixtures containing concentrations as little as only 1% of the respective individual median lethal tolerances (LC(50)s) caused significantly more mortality and delayed larval development than would be expected from the responses selenate and methylmercury elicit individually. However, survival and pupal development was not affected at any rate tested. Female fecundity was significantly decreased by methylmercury but not by selenate or mixture treatments. The relative toxicity to M. scalaris of each of the individual and joint treatments was selenate (LC(50) = 260 microg/g) < methylmercury (LC(50) = 22 microg/g) < the mixture at approximately 5% of the LC(50) concentration of each of the components (12 microg/g selenate plus 1.0 microg/g methylmercury). The increased mortality and delayed larval development within sites contaminated by selenate, methylmercury, or combination of the two have substantial implications for the ecology, population dynamics, and sustainability of M. scalaris populations. If these results can be extrapolated to other arthropod detritivores, ecosystem food-web function may be substantially affected.
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Affiliation(s)
- P D Jensen
- Department of Entomology, University of California, Riverside, 92521, USA.
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Lamprecht R, Margulies DS, Farb CR, Hou M, Johnson LR, LeDoux JE. Myosin light chain kinase regulates synaptic plasticity and fear learning in the lateral amygdala. Neuroscience 2006; 139:821-9. [PMID: 16515842 DOI: 10.1016/j.neuroscience.2005.12.055] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [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: 10/06/2005] [Revised: 12/18/2005] [Accepted: 12/22/2005] [Indexed: 01/29/2023]
Abstract
Learning and memory depend on signaling molecules that affect synaptic efficacy. The cytoskeleton has been implicated in regulating synaptic transmission but its role in learning and memory is poorly understood. Fear learning depends on plasticity in the lateral nucleus of the amygdala. We therefore examined whether the cytoskeletal-regulatory protein, myosin light chain kinase, might contribute to fear learning in the rat lateral amygdala. Microinjection of ML-7, a specific inhibitor of myosin light chain kinase, into the lateral nucleus of the amygdala before fear conditioning, but not immediately afterward, enhanced both short-term memory and long-term memory, suggesting that myosin light chain kinase is involved specifically in memory acquisition rather than in posttraining consolidation of memory. Myosin light chain kinase inhibitor had no effect on memory retrieval. Furthermore, ML-7 had no effect on behavior when the training stimuli were presented in a non-associative manner. Anatomical studies showed that myosin light chain kinase is present in cells throughout lateral nucleus of the amygdala and is localized to dendritic shafts and spines that are postsynaptic to the projections from the auditory thalamus to lateral nucleus of the amygdala, a pathway specifically implicated in fear learning. Inhibition of myosin light chain kinase enhanced long-term potentiation, a physiological model of learning, in the auditory thalamic pathway to the lateral nucleus of the amygdala. When ML-7 was applied without associative tetanic stimulation it had no effect on synaptic responses in lateral nucleus of the amygdala. Thus, myosin light chain kinase activity in lateral nucleus of the amygdala appears to normally suppress synaptic plasticity in the circuits underlying fear learning, suggesting that myosin light chain kinase may help prevent the acquisition of irrelevant fears. Impairment of this mechanism could contribute to pathological fear learning.
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Affiliation(s)
- R Lamprecht
- W. M. Keck Foundation Laboratory for Neurobiology, Center for Neural Science, New York University, 4 Washington Place, Room 809, New York, NY 10003, USA.
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Johnson LR, Farb C, Morrison JH, McEwen BS, LeDoux JE. Localization of glucocorticoid receptors at postsynaptic membranes in the lateral amygdala. Neuroscience 2005; 136:289-99. [PMID: 16181741 DOI: 10.1016/j.neuroscience.2005.06.050] [Citation(s) in RCA: 165] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2004] [Revised: 06/11/2005] [Accepted: 06/16/2005] [Indexed: 01/08/2023]
Abstract
Glucocorticoids, released in high concentrations from the adrenal cortex during stressful experiences, bind to glucocorticoid receptors in nuclear and peri-nuclear sites in neuronal somata. Their classically known mode of action is to induce gene promoter receptors to alter gene transcription. Nuclear glucocorticoid receptors are particularly dense in brain regions crucial for memory, including memory of stressful experiences, such as the hippocampus and amygdala. While it has been proposed that glucocorticoids may also act via membrane bound receptors, the existence of the latter remains controversial. Using electron microscopy, we found glucocorticoid receptors localized to non-genomic sites in rat lateral amygdala, glia processes, presynaptic terminals, neuronal dendrites, and dendritic spines including spine organelles and postsynaptic membrane densities. The lateral nucleus of the amygdala is a region specifically implicated in the formation of memories for stressful experiences. These newly observed glucocorticoid receptor immunoreactive sites were in addition to glucocorticoid receptor immunoreactive signals observed using electron and confocal microscopy in lateral amygdala principal neuron and GABA neuron soma and nuclei, cellular domains traditionally associated with glucocorticoid immunoreactivity. In lateral amygdala, glucocorticoid receptors are thus also localized to non-nuclear-membrane translocation sites, particularly dendritic spines, where they show an affinity for postsynaptic membrane densities, and may have a specialized role in modulating synaptic transmission plasticity related to fear and emotional memory.
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Affiliation(s)
- L R Johnson
- NIMH Conte Center for the Neuroscience of Fear and Anxiety Center for Neural Science, 4 Washington Place, New York University, New York, NY 10003, USA.
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Sullivan GM, Apergis J, Bush DEA, Johnson LR, Hou M, Ledoux JE. Lesions in the bed nucleus of the stria terminalis disrupt corticosterone and freezing responses elicited by a contextual but not by a specific cue-conditioned fear stimulus. Neuroscience 2004; 128:7-14. [PMID: 15450349 DOI: 10.1016/j.neuroscience.2004.06.015] [Citation(s) in RCA: 256] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2004] [Indexed: 11/26/2022]
Abstract
The bed nucleus of the stria terminalis (BNST) is believed to be a critical relay between the central nucleus of the amygdala (CE) and the paraventricular nucleus of the hypothalamus in the control of hypothalamic-pituitary-adrenal (HPA) responses elicited by conditioned fear stimuli. If correct, lesions of CE or BNST should block expression of HPA responses elicited by either a specific conditioned fear cue or a conditioned context. To test this, rats were subjected to cued (tone) or contextual classical fear conditioning. Two days later, electrolytic or sham lesions were placed in CE or BNST. After 5 days, the rats were tested for both behavioral (freezing) and neuroendocrine (corticosterone) responses to tone or contextual cues. CE lesions attenuated conditioned freezing and corticosterone responses to both tone and context. In contrast, BNST lesions attenuated these responses to contextual but not tone stimuli. These results suggest CE is indeed an essential output of the amygdala for the expression of conditioned fear responses, including HPA responses, regardless of the nature of the conditioned stimulus. However, because lesions of BNST only affected behavioral and endocrine responses to contextual stimuli, the results do not support the notion that BNST is critical for HPA responses elicited by conditioned fear stimuli in general. Instead, the BNST may be essential specifically for contextual conditioned fear responses, including both behavioral and HPA responses, by virtue of its connections with the hippocampus, a structure essential to contextual conditioning. The results are also not consistent with the hypothesis that BNST is only involved in unconditioned aspects of fear and anxiety.
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Affiliation(s)
- G M Sullivan
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, 1051 Riverside Drive, Unit #41, New York, NY 10032, USA.
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Nelson DA, Walters TJ, Ryan KL, Emerton KB, Hurt WD, Ziriax JM, Johnson LR, Mason PA. Inter-species extrapolation of skin heating resulting from millimeter wave irradiation: modeling and experimental results. Health Phys 2003; 84:608-615. [PMID: 12747480 DOI: 10.1097/00004032-200305000-00006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This study reports measurements of the skin surface temperature elevations during localized irradiation (94 GHz) of three species: rat (irradiated on lower abdomen), rhesus monkey (posterior forelimb), and human (posterior forearm). Two exposure conditions were examined: prolonged, low power density microwaves (LPM) and short-term, high power density microwaves (HPM). Temperature histories were compared with calculations from a bio-heat transfer model. The mean peak surface temperature increase was approximately 7.0 degrees C for the short-term HPM exposures for all three species/locations, and 8.5 degrees C (monkey, human) to 10.5 degrees C (rat) for the longer-duration LPM exposures. The HPM temperature histories are in close agreement with a one-dimensional conduction heat transfer model with negligible blood flow. The LPM temperature histories were compared with calculations from the bio-heat model, evaluated for various (constant) blood flow rates. Results suggest a variable blood flow model, reflecting a dynamic thermoregulatory response, may be more suited to describing skin surface temperature response under long-duration MMW irradiation.
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Affiliation(s)
- D A Nelson
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931, USA.
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Vollmer WM, Tsai R, Wu Y, Li YH, Johnson LR, Williams OD, Li Y, Rao X, Buist AS. Patterns of lung function in asymptomatic nonsmoking men and women in the People's Republic of China. Ann Epidemiol 2002; 12:295-302. [PMID: 12062915 DOI: 10.1016/s1047-2797(01)00288-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE To evaluate patterns of lung function in healthy, working Chinese men and women in different geographic areas of the People's Republic of China (PRC). METHODS We conducted lung function tests on 2926 asymptomatic, never smoking Chinese men and women aged 35-56 years residing in or around Beijing and Guangzhou. Within each of these locations, separate urban and rural samples were recruited. RESULTS Age and height adjusted lung function was greater in Beijing than in Guangzhou, and within each city for residents of rural vs. urban areas. Among women, estimated rates of lung aging were greater in Beijing than in Guangzhou, and in urban vs. rural areas. Both FEV(1) and FVC exhibited a curvilinear association with body mass index. CONCLUSIONS Lung function data from this largely working cohort exhibited marked geographic and urban-rural differences in this never smoking, adult Chinese cohort. Such variation is not uncommon and may reflect differences in body size, diet, and environmental and occupational exposures across these different settings. Caution should be used in applying published reference equations to populations from different parts of the PRC.
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Affiliation(s)
- W M Vollmer
- Kaiser Permanente Center for Health Research, Portland, OR, USA
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Johnson LR, Stoller NH. Rationale for the use of Atridox therapy for managing periodontal patients. Compend Contin Educ Dent 2002; 20:19-25; quiz 35. [PMID: 11908360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
This article reviews the studies that provided the safety and efficacy data essential for the Food and Drug Administration approval of Atridox. These studies detail the clinical effectiveness of Atridox and provide the foundation for an understanding of the use of Atridox in the clinical management of patients with periodontitis. Atridox is a locally delivered, controlled-release system for the administration of high concentrations of doxycycline to the periodontal pocket. Nine-month clinical studies involving more than 800 patients have shown Atridox and scaling and root planing to be superior to placebo and oral hygiene for the efficacy parameters of attachment level, probing depth, and bleeding on probing. The positive clinical effects are consistent throughout a wide range of patients with varied histories of periodontal therapy. The implications of these findings as they relate to clinical practice are briefly addressed.
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Affiliation(s)
- L R Johnson
- Division of Periodontics, Department of Surgical Dentistry, University of Colorado School of Dentistry, Denver, Colorado, USA
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Pfeffer LM, Yang CH, Murti A, McCormack SA, Viar MJ, Ray RM, Johnson LR. Polyamine depletion induces rapid NF-kappa B activation in IEC-6 cells. J Biol Chem 2001; 276:45909-13. [PMID: 11590175 DOI: 10.1074/jbc.m108097200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [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: 11/06/2022] Open
Abstract
The proliferation of the rat intestinal mucosal IEC-6 cell line requires polyamines, whose synthesis is catalyzed by the enzyme ornithine decarboxylase (ODC). ODC inhibition leads to polyamine depletion, as well as inhibition of both cell proliferation and apoptosis by regulating gene expression. The NF-kappa B transcription factor regulates genes involved in apoptotic, immune, and inflammatory responses. In the present study we tested the hypothesis that NF-kappa B is activated following ODC inhibition. We found that the inhibition of ODC by alpha-difluoromethylornithine (DFMO) resulted in a approximately 50% decrease in intracellular putrescine levels within 1 h. NF-kappa B is activated by DFMO through the degradation of the inhibitory protein I kappa B alpha that sequesters NF-kappa B in the cytoplasm. The DFMO-induced NF-kappa B complexes contain the p65 and p50 members of the Rel protein family. DFMO-induced NF-kappa B activation was accompanied by the translocation of p65 from the cytoplasm into the nucleus. DFMO selectively inhibited a gene reporter construct dependent on the kappa B site present in the HLA-B7 gene. In contrast, DFMO had no effect on a gene reporter construct dependent on the kappa B site present in the interleukin-8 gene. Thus, we report that ODC inhibition activates the NF-kappa B transcription factor, which may mediate the altered physiological state of intestinal cells that occurs following polyamine depletion.
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Affiliation(s)
- L M Pfeffer
- Department of Pathology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
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Abstract
OBJECTIVE To investigate the role of bacteria in bronchoscopically diagnosed tracheal collapse in dogs by evaluating qualitative results of bacteriologic cultures. DESIGN Retrospective study. ANIMALS 37 dogs with tracheal collapse. PROCEDURE Clinical records for dogs with tracheal collapse confirmed with bronchoscopy were reviewed. A protected catheter brush was used to obtain samples for bacteriologic culture from the large airways. RESULTS Results of bacterial culture were negative for 5 of 29 dogs. For 24 dogs, 1 (n = 10), 2 (6), or > or = 3 (8) species of bacteria were isolated. Pseudomonas spp were isolated most frequently (17/29), and a single Pseudomonas sp grew in 7 samples. Other bacteria included Enterobacter spp (4/29), Citrobacter spp (3/29), and Moraxella spp, Klebsiella spp, Bordetella spp, or Acinetobacter spp (2/29 dogs each). Anaerobic and aerobic cultures yielded positive results in samples from 2 dogs. Cytologic results were available for 13 dogs with positive results of bacteriologic culture; epithelial cells were reported most commonly. Five samples had a small number of neutrophils; bacteria were identified cytologically in 2 of 5 samples that contained neutrophils. Bacteria were also seen in 2 samples that lacked inflammatory cells. CONCLUSIONS AND CLINICAL RELEVANCE Bacteria are commonly isolated from samples obtained via airway brushing in dogs with tracheal collapse; however, in the absence of cytologic confirmation of inflammation or infection, an association between bacteria and clinical signs of tracheal collapse cannot be established.
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Affiliation(s)
- L R Johnson
- Department of Veterinary Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, USA
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McCormack SA, Johnson LR. Polyamines and cell migration. J Physiol Pharmacol 2001; 52:327-49. [PMID: 11596855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Leeuwenhoek first described polyamines in 1677, but active investigation did not begin until the 1970's. When intracellular polyamine levels are reduced by inhibitors, mutation, or transfection, severe reductions occur in cell division, cell differentiation, and cell migration. These effects are not difficult to demonstrate and measure, and all can be prevented if supplemental exogenous polyamines are supplied. However, linking the overall effects to molecular events remains to be accomplished. In this review, we discuss work (mostly from the last 10 years) that relates to cell migration. Specifically, we have discussed the biology and biochemistry of the polyamines, their transport and regulation, the structure of the cytoskeleton and the mechanics of cell movement. We have also considered four specific processes that polyamines participate in that may affect cell migration significantly. These are: 1) the regulation of intracellular Ca++ concentration by voltage-gated K+ channels, 2) the maintenance of normal RhoA levels that, with Rac, regulate the assembly of actin stress fibers, focal adhesions, and contractility, 3) the formation of ATP-Mg++-polyamine trimers that enhance the phosphorylation activity of ATP toward enzymes in specific signaling pathways and, 4) alterations in the structure of RNA that change translation initiation sites and affect the expression of proteins.
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Affiliation(s)
- S A McCormack
- Department of Physiology, University of Tennessee Health Science Center, Memphis 38163, USA
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Abstract
Polyamines are essential to the migration of epithelial cells in the intestinal mucosa. Cells depleted of polyamines do not attach as rapidly to the extracellular matrix and do not form the actin stress fibers essential for migration. Because both attachment and stress fiber formation depend on integrin signaling and the formation of focal adhesions, we examined these and related processes in polyamine-depleted IEC-6 cells. There was general decreased tyrosine phosphorylation of focal adhesion kinase (FAK), and, specifically, decreased phosphorylation of Tyr-925, the paxillin binding site. In control cells, FAK phosphorylation was rapid after attachment to the extracellular matrix, while attached cells depleted of polyamines had significantly delayed phosphorylation. FAK activity was also significantly inhibited in polyamine-depleted cells as was the phosphorylation of paxillin. Polyamine-depleted cells failed to spread normally after attachment, and immunocytochemistry showed little colocalization of FAK and actin compared with controls. Focal adhesion complex formation was greatly reduced in the absence of polyamines. These data suggest that defective integrin signaling may, at least in part, account for the decreased rates of attachment, actin stress fiber formation, spreading, and migration observed in polyamine-depleted cells.
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Affiliation(s)
- R M Ray
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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Abstract
The polyamines spermidine and spermine and their precursor, putrescine, are required for the growth and proliferation of eukaryotic cells. This study compares and contrasts growth arrest caused by polyamine depletion in the untransformed IEC-6 cell line with that in the p53-mutated colon cancer Caco-2 cell line. Cells were grown in the presence or absence of alpha-difluoromethylornithine (DFMO), a specific inhibitor of ornithine decarboxylase, the first rate-limiting enzyme in the synthesis of polyamines. Depletion of polyamines inhibited the growth of both cell lines equally and over the same time frame. However, whereas IEC-6 cells were arrested in the G(1) phase of the cell cycle, there was no accumulation of Caco-2 cells in any particular phase. In IEC-6 cells, growth arrest was accompanied by elevated levels of p53 and p21(Waf1/Cip1) (p21). There were no changes in p53 levels in Caco-2 cells. Levels of p21 increased in Caco-2 cells on day 2 without any effect on cell cycle progression. The amount of cyclin-dependent kinase (Cdk)2 protein was unchanged by polyamine depletion in both cell lines. However, the activity of Cdk2 was significantly inhibited by DFMO in IEC-6 cells. These data suggest that in the untransformed IEC-6 cells the regulation of Cdk2 activity and progression through the cell cycle are p53- and p21 dependent. Growth arrest in the p53-mutated Caco-2 line after polyamine depletion occurs by a different, yet unknown, mechanism.
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Affiliation(s)
- R M Ray
- Department of Physiology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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Johnson LR, Doherty G, Lairmore T, Moley JF, Brunt LM, Koenig J, Scott MG. Evaluation of the performance and clinical impact of a rapid intraoperative parathyroid hormone assay in conjunction with preoperative imaging and concise parathyroidectomy. Clin Chem 2001; 47:919-25. [PMID: 11325897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
BACKGROUND (99m)Tc-sestamibi scans and rapid, intraoperative intact parathyroid hormone (PTH) assays allow preoperative identification of diseased glands and intraoperative confirmation of diseased gland removal, respectively. Use of these two new technologies may facilitate simpler, more concise surgery, shorter hospital stays, and decreased costs for frozen-section analysis. One major drawback to this new strategy has been the high cost of rapid point-of-care PTH assays. METHODS We performed rapid PTH assays with the DPC Turbo PTH assay on the DPC IMMULITE automated analyzer. The number of intraoperative frozen sections, type of anesthesia, surgical approach, length of hospital stay, and pre- and postoperative calcium values were compared between a group of 49 patients undergoing parathyroidectomy where the intraoperative PTH assay was used in conjunction with preoperative imaging, and a historical control group of 55 patients before the use of these two technologies in our institution. RESULTS Comparison of the Turbo PTH assay to the standard IMMULITE PTH assay gave the following: y = 1.08 x - 4.36 (r = 0.97; n = 48). For the 49 patients, the median turnaround time for each intraoperative PTH determination was 19 min (range, 14-40 min). The median decrease in PTH values from baseline was 88% (range, 33-99%). Thirty-seven patients required two PTH determinations, 7 required three, 4 had four, and 1 required five determinations. The average laboratory cost for the rapid intraoperative PTH assays was < $100 per patient (range, $55 to $113). Compared with the control group, the experimental group had significantly fewer frozen sections (1.4 vs 2.5; P < 0.0001), shorter hospital stays (17 discharged on the day of surgery vs none discharged on the day of surgery; P < 0.0001), greater use of local anesthesia (33% vs 0%; P < 0.001), and more unilateral, rather than bilateral neck explorations (65% vs 0%; P < 0.001). CONCLUSIONS The combination of intraoperative Turbo PTH assay and preoperative (99m)Tc-sestamibi scans can lead to significant decreases in laboratory and surgical pathology costs, hospital stays, and exposure to general anesthesia by facilitating concise parathyroidectomy surgery.
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Affiliation(s)
- L R Johnson
- Washington University School of Medicine, Department of Pathology and Immunology, Barnes-Jewish Hospital, St. Louis, MO 63110, USA
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Abstract
The addiction potential of anabolic steroids remains largely unexplored. Here, we demonstrate voluntary oral testosterone intake in hamsters. Using a 2-bottle choice test, males preferred an aqueous solution of 200 microg/ml testosterone over vehicle. However, the taste of testosterone is not highly preferred. Addition of testosterone at 400 microg/ml increased fluid consumption from the nonpreferred bottle in a 2-bottle choice test, but cholesterol at the same concentration reduced drinking, suggesting that testosterone reward is not common to all sterols. With food-induced drinking, testosterone maintained fluid intake when food was withdrawn. These data demonstrate that oral self-administration of testosterone is reinforcing in hamsters, suggesting the potential for dependence in human users.
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Affiliation(s)
- L R Johnson
- Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Conn., USA
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Johnson LR, Rush JW, Turk JR, Price EM, Laughlin MH. Short-term exercise training increases ACh-induced relaxation and eNOS protein in porcine pulmonary arteries. J Appl Physiol (1985) 2001; 90:1102-10. [PMID: 11181626 DOI: 10.1152/jappl.2001.90.3.1102] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [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: 11/22/2022] Open
Abstract
We tested the hypothesis that short-term exercise (STEx) training and the associated increase in pulmonary blood flow during bouts of exercise cause enhanced endothelium-dependent vasorelaxation in porcine pulmonary arteries and increased expression of endothelial cell nitric oxide synthase (eNOS) and superoxide dismutase-1 (SOD-1) protein. Mature, female Yucatan miniature swine exercised 1 h twice daily on a motorized treadmill for 1 wk (STEx group, n = 7); control pigs (Sed, n = 6) were kept in pens. Pulmonary arteries were isolated from the left caudal lung lobe, and vasomotor responses were determined in vitro. Arterial tissue from the distal portion of this pulmonary artery was processed for immunoblot analysis. Maximal endothelium-dependent (ACh-stimulated) relaxation was greater in STEx (71 +/- 5%) than in Sed (44 +/- 6%) arteries (P < 0.05), and endothelium-independent (sodium nitroprusside-mediated) responses did not differ. Sensitivity to ACh was not altered by STEx training. Immunoblot analysis indicated a 3.9-fold increase in eNOS protein in pulmonary artery tissue from STEx pigs (P < 0.05) with no change in SOD-1 or glyceraldehyde-3-phosphate dehydrogenase protein levels. We conclude that STEx training enhances ACh-stimulated vasorelaxation in pulmonary arterial tissue and that this adaptation is associated with increased expression of eNOS protein.
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Affiliation(s)
- L R Johnson
- Department of Veterinary Biomedical Sciences, University of Missouri, Columbia, Missouri 65211, USA.
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Stoller NH, Johnson LR, Garrett S. Periodontal regeneration of a class II furcation defect utilizing a bioabsorbable barrier in a human. A case study with histology. J Periodontol 2001; 72:238-42. [PMID: 11288798 DOI: 10.1902/jop.2001.72.2.238] [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: 11/13/2022]
Abstract
This case report describes human histologic data of periodontal regeneration following guided tissue regeneration therapy (GTR) with a bioabsorbable barrier composed of polylactic acid. The tooth that was examined was part of a previously published study of the clinical effects of GTR therapy without the use of bone or bone substitutes on Class II furcation defects. Twenty-five months following the surgical procedure, the tooth was extracted for non-periodontal reasons. During this extraction, the bone within the furcation that was treated in the study was luxated with the tooth. At the completion of the study (month 12), the furcation's vertical probing depth had decreased by 2 mm with a 2 mm gain in clinical attachment. The horizontal furcation measurement decreased by 3 mm. Following extraction, the tooth was prepared for light microscopy and sectioned in the mesial-distal plane. Reference notches were not placed in the tooth at the time of surgery as there were no plans to perform histologic analysis in the study. However, using the buccal root prominences and what we interpreted to be root planing marks on the cementum, we were able to demonstrate that complete periodontal regeneration occurred on the root surface that was exposed to the pocket environment prior to surgery. New alveolar bone, cementum, and periodontal ligament were consistently observed throughout the furcation in the areas that demonstrated clinical attachment gain and a decrease in horizontal probing depth. This case report adds to the accumulating evidence of histologic periodontal regeneration following guided tissue regeneration with bioabsorbable polylactic acid barriers.
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Affiliation(s)
- N H Stoller
- Department of Surgical Dentistry, University of Colorado School of Dentistry, Denver 80262, USA
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Abstract
Ornithine decarboxylase (ODC) is feedback regulated by polyamines. ODC antizyme mediates this process by forming a complex with ODC and enhancing its degradation. It has been reported that polyamines induce ODC antizyme and inhibit ODC activity. Since exogenous polyamines can be converted to each other after they are taken up into cells, we used an inhibitor of S-adenosylmethionine decarboxylase, diethylglyoxal bis(guanylhydrazone) (DEGBG), to block the synthesis of spermidine and spermine from putrescine and investigated the specific roles of individual polyamines in the regulation of ODC in intestinal epithelial crypt (IEC-6) cells. We found that putrescine, spermidine, and spermine inhibited ODC activity stimulated by serum to 85, 46, and 0% of control, respectively, in the presence of DEGBG. ODC activity increased in DEGBG-treated cells, despite high intracellular putrescine levels. Although exogenous spermidine and spermine reduced ODC activity of DEGBG-treated cells close to control levels, spermine was more effective than spermidine. Exogenous putrescine was much less effective in inducing antizyme than spermidine or spermine. High putrescine levels in DEGBG-treated cells did not induce ODC antizyme when intracellular spermidine and spermine levels were low. The decay of ODC activity and reduction of ODC protein levels were not accompanied by induction of antizyme in the presence of DEGBG. Our results indicate that spermine is the most, and putrescine the least, effective polyamine in regulating ODC activity, and upregulation of antizyme is not required for the degradation of ODC protein.
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Affiliation(s)
- Q Yuan
- Department of Physiology, College of Medicine, The University of Tennessee, Memphis, Tennessee 38163, USA
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Abstract
Previous studies have shown that the transcription of the fibroblast growth factor-4 (FGF-4) gene is regulated by a powerful enhancer located approximately three kilobases downstream of the transcription start site. Several conserved cis-regulatory elements in the promoter and the enhancer have been identified, including two Sp1 motifs located in the promoter and one Sp1 motif located in the enhancer. Each of these Sp1 motifs has been shown previously to bind the transcription factors Sp1 and Sp3 in vitro. The main objective of this study was to examine the potential interaction of the FGF-4 promoter and enhancer Sp1 motifs. Using site-directed mutagenesis, we demonstrate that disruption of these sites, individually or in combination, reduce the expression of FGF-4 promoter/reporter gene constructs in embryonal carcinoma cells. Importantly, we demonstrate that disruption of the enhancer Sp1 motif exerts a more pronounced effect on the expression of these constructs than disruption of the promoter Sp1 motifs. We also demonstrate that changing the spacing and the stereo-alignment of the enhancer Sp1 motif, relative to the other cis-regulatory elements of the enhancer, has little effect on the ability of the enhancer to stimulate transcription. Furthermore, embryonic stem cells that contain two disrupted Sp1 alleles were used to demonstrate that the transcription factor Sp1 is not necessary for expression of the endogenous FGF-4 gene. Finally, the significance of these findings relative to a looping model for the transcriptional activation of the FGF-4 gene is discussed.
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Affiliation(s)
- T A Luster
- Eppley Institute for the Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
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Abstract
Adenosine (ADO), an endogenous regulator of coronary vascular tone, enhances vasorelaxation in the presence of nucleoside transport inhibitors such as dipyridamole. We tested the hypothesis that coronary smooth muscle (CSM) contains a high-affinity transporter for ADO. ADO-mediated relaxation of isolated large and small porcine coronary artery rings was enhanced 12-fold and 3.4-fold, respectively, by the transport inhibitor, S-(4-nitrobenzyl)-6-thioinosine (NBTI). Enhanced relaxation was independent of endothelium and was selective for ADO over synthetic analogs. Uptake of [(3)H]ADO into freshly dissociated CSM cells or endothelium-denuded rings was linear and concentration dependent. Kinetic analysis yielded a maximum uptake (V(max)) of 67 +/- 7.0 pmol. mg protein(-1). min(-1) and a Michaelis constant (K(m)) of 10. 5 +/- 5.8 microM in isolated cells and a V(max) of 5.1 +/- 0.5 pmol. min(-1). mg wet wt(-1) and a K(m) of 17.6 +/- 2.6 microM in intact rings. NBTI inhibited transport into small arteries (IC(50) = 42 nM) and cells. Analyses of extracellular space and diffusion kinetics using [(3)H]sucrose indicate the V(max) and K(m) for ADO transport are sufficient to clear a significant amount of extracellular adenosine. These data indicate CSM possess a high-affinity nucleoside transporter and that the activity of this transporter is sufficient to modulate ADO sensitivity of large and small coronary arteries.
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Affiliation(s)
- L J Rubin
- Department of Veterinary Biomedical Sciences, University of Missouri-Columbia, Columbia, Missouri 65211, USA.
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45
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Abstract
Previous studies have shown that the transcription of the fibroblast growth factor-4 (FGF-4) gene is regulated by a powerful enhancer located approximately three kilobases downstream of the transcription start site. Several conserved cis-regulatory elements in the promoter and the enhancer have been identified, including two Sp1 motifs located in the promoter and one Sp1 motif located in the enhancer. Each of these Sp1 motifs has been shown previously to bind the transcription factors Sp1 and Sp3 in vitro. The main objective of this study was to examine the potential interaction of the FGF-4 promoter and enhancer Sp1 motifs. Using site-directed mutagenesis, we demonstrate that disruption of these sites, individually or in combination, reduce the expression of FGF-4 promoter/reporter gene constructs in embryonal carcinoma cells. Importantly, we demonstrate that disruption of the enhancer Sp1 motif exerts a more pronounced effect on the expression of these constructs than disruption of the promoter Sp1 motifs. We also demonstrate that changing the spacing and the stereo-alignment of the enhancer Sp1 motif, relative to the other cis-regulatory elements of the enhancer, has little effect on the ability of the enhancer to stimulate transcription. Furthermore, embryonic stem cells that contain two disrupted Sp1 alleles were used to demonstrate that the transcription factor Sp1 is not necessary for expression of the endogenous FGF-4 gene. Finally, the significance of these findings relative to a looping model for the transcriptional activation of the FGF-4 gene is discussed.
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Affiliation(s)
- T A Luster
- Eppley Institute for the Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
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46
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Abstract
Exercise training increases acetylcholine-induced pulmonary vasorelaxation in pigs with coronary occlusion. The present study tested the hypothesis that chronic exercise training enhances endothelium-mediated vasorelaxation in pulmonary arteries from normal pigs. Yucatan miniswine exercised for 16 wk on a treadmill (Ex); control pigs (Sed) remained in pens. Pulmonary artery rings (2- to 3-mm OD) were studied using standard isometric techniques. Contractile responses to 80 mM KCl and norepinephrine (NE) were determined. Vessels were constricted with levels of NE that resulted in half-maximal contraction to examine endothelium-dependent relaxation to ACh and endothelium-independent relaxation to sodium nitroprusside in the presence and absence of nitric oxide synthase inhibition, cyclooxygenase inhibition, and endothelial denudation. Arteries from Ex pigs developed increased contraction to 80 mM KCl, but the response to NE did not differ between groups. Endothelium-dependent and endothelium-independent responses did not differ between Sed and Ex in the presence or absence of pharmacological inhibitors or denudation. We conclude that chronic exercise training does not alter endothelium-dependent or endothelium-independent vasorelaxation responses of pulmonary arteries from normal pigs.
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Affiliation(s)
- L R Johnson
- Department of Veterinary Biomedical Sciences, University of Missouri, Columbia 65211, USA.
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47
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Abstract
The polyamines spermidine, spermine, and their precursor putrescine are essential for cell growth and the regulation of the cell cycle. Recent studies suggest that excessive accumulation of polyamines favors either malignant transformation or apoptosis, depending on the cell type and the stimulus. This study examines the involvement of polyamines in the induction of apoptosis by the DNA topoisomerase I inhibitor, camptothecin. In IEC-6 cells, camptothecin induced apoptosis within 6 h, accompanied by detachment of cells. Detached cells showed DNA laddering and caspase 3 induction, characteristic features of apoptosis. Depletion of putrescine, spermidine, and spermine by DL-alpha-difluoromethylornithine (DFMO), a specific inhibitor of ornithine decarboxylase (ODC) that is the first rate-limiting enzyme for polyamine biosynthesis, decreased the apoptotic index. Delayed apoptosis was accompanied by a decrease in caspase 3 activity in polyamine-depleted cells. Addition of putrescine restored the induction of apoptosis as indicated by an increase in the number of detached cells and caspase 3 activity. Polyamine depletion did not change the level of caspase 3 protein. Inhibition of S-adenosylmethionine decarboxylase by a specific inhibitor [diethylglyoxal bis-(guanylhydrazone); DEGBG] led to depletion of spermidine and spermine with a significant accumulation of putrescine and induction of ODC. The DEGBG-treated cells showed an increase in apoptosis, suggesting the importance of putrescine in the apoptotic process. Addition of putrescine to DFMO-treated cell extracts did not increase caspase 3 activity. The above results indicate that polyamine depletion delays the onset of apoptosis in IEC-6 cells and confers protection against DNA damaging agents, suggesting that polyamines might be involved in the caspase activating signal cascade.
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Affiliation(s)
- R M Ray
- Department of Physiology, College of Medicine, University of Tennessee, Memphis, Memphis, Tennessee 38163, USA.
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48
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Johnson LR, Dodam JR, Laughlin MH. Endothelium-dependent relaxation differs in porcine pulmonary arteries from the left and right caudal lobes. J Appl Physiol (1985) 2000; 88:827-34. [PMID: 10710375 DOI: 10.1152/jappl.2000.88.3.827] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 11/22/2022] Open
Abstract
We hypothesized that pulmonary arteries (PA) from identical branch orders within left and right caudal lung lobes would exhibit similar vasomotor responses. Arterial rings from caudal lung lobes of female swine were examined in vitro. Vascular smooth muscle contraction to KCl and norepinephrine did not differ. Vascular relaxation to endothelium-dependent (bradykinin, acetylcholine, A-23187) and -independent (sodium nitroprusside, zero-calcium Krebs solution) vasodilators was assessed. Right PA exhibited less maximal relaxation to acetylcholine (50%) than did left PA (69%; P < 0.001). Maximal relaxation to sodium nitroprusside did not differ, although right PA had a lower drug concentration resulting in half-maximal relaxation (6.26 x 10(-8) M) than did left PA (9.57 x 10(-8) M; P < 0.05). Nitric oxide synthase inhibition with an arginine analog (N(omega)-nitro-L-arginine methyl ester) depressed acetylcholine-induced relaxation but the left vs. right difference persisted. Indomethacin enhanced relaxation to acetylcholine and abolished the difference between left and right. We conclude that endothelium-dependent vasorelaxation is less in porcine right than in left PA because of greater release of one or more constricting prostanoids in arteries from the right caudal lobe.
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Affiliation(s)
- L R Johnson
- Department of Veterinary Biomedical Sciences, University of Missouri, Columbia, Missouri 65211, USA.
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49
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Walters TJ, Blick DW, Johnson LR, Adair ER, Foster KR. Heating and pain sensation produced in human skin by millimeter waves: comparison to a simple thermal model. Health Phys 2000; 78:259-267. [PMID: 10688448 DOI: 10.1097/00004032-200003000-00003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [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
Cutaneous thresholds for thermal pain were measured in 10 human subjects during 3-s exposures at 94 GHz continuous wave microwave energy at intensities up to approximately 1.8 W cm(-2). During each exposure, the temperature increase at the skin's surface was measured by infrared thermography. The mean (+/- s.e.m.) baseline temperature of the skin was 34.0+/-0.2 degrees C. The threshold for pricking pain was 43.9+/-0.7 degrees C, which corresponded to an increase in surface temperature of approximately 9.9 degrees C (from 34.0 degrees C to 43.9 degrees C). The measured increases in surface temperature were in good agreement with a simple thermal model that accounted for heat conduction and for the penetration depth of the microwave energy into tissue. Taken together, these results support the use of the model for predicting thresholds of thermal pain at other millimeter wave (length) frequencies.
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Affiliation(s)
- T J Walters
- Veridian Engineering, Inc., Brooks Air Force Base, TX 78235, USA.
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50
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Nowling TK, Johnson LR, Wiebe MS, Rizzino A. Identification of the transactivation domain of the transcription factor Sox-2 and an associated co-activator. J Biol Chem 2000; 275:3810-8. [PMID: 10660531 DOI: 10.1074/jbc.275.6.3810] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [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: 11/06/2022] Open
Abstract
The importance of interactions between Sox and POU transcription factors in the regulation of gene expression is becoming increasingly apparent. Recently, many examples of the involvement of Sox-POU partnerships in transcription have been discovered, including a partnership between Sox-2 and Oct-3. Little is known about the mechanisms by which these factors modulate transcription. To better understand the molecular interactions involved, we mapped the location of the transactivation domain of Sox-2. This was done in the context of its interaction with Oct-3, as well as its ability to transactivate as a fusion protein linked to the DNA-binding domain of Gal4. Both approaches demonstrated that Sox-2 contains a transactivation domain in its C-terminal half, containing a serine-rich region and the C terminus. We also determined that the viral oncoprotein E1a inhibits the ability of the Gal4/Sox-2 fusion protein to transactivate, as well as the transcriptional activation mediated by the combined action of Sox-2 and Oct-3. In contrast, a mutant form of E1a, unable to bind p300, lacks both of these effects. Importantly, we determined that p300 overcomes the inhibitory effects of E1a in both assays. Together, these findings suggest that Sox-2 mediates its effects, at least in part, through the co-activator p300.
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Affiliation(s)
- T K Nowling
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
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