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Kutzsche J, Schemmert S, Bujnicki T, Zafiu C, Halbgebauer S, Kraemer-Schulien V, Pils M, Blömeke L, Post J, Kulawik A, Jürgens D, Rossberg WM, Hümpel M, Bannach O, Otto M, Araujo JA, Willuweit A, Willbold D. Oral treatment with the all-d-peptide RD2 enhances cognition in aged beagle dogs - A model of sporadic Alzheimer's disease. Heliyon 2023; 9:e18443. [PMID: 37609390 PMCID: PMC10440458 DOI: 10.1016/j.heliyon.2023.e18443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 07/14/2023] [Accepted: 07/18/2023] [Indexed: 08/24/2023] Open
Abstract
Disease-modifying therapies to treat Alzheimer's disease (AD) are of fundamental interest for aging humans, societies, and health care systems. Predictable disease progression in transgenic AD models favors preclinical studies employing a preventive study design with an early pre-symptomatic treatment start, instead of assessing a truly curative approach with treatment starting after diagnosed disease onset. The aim of this study was to investigate the pharmacokinetic profile and efficacy of RD2 to enhance short-term memory and cognition in cognitively impaired aged Beagle dogs - a non-transgenic model of truly sporadic AD. RD2 has previously demonstrated pharmacodynamic efficacy in three different transgenic AD mouse models in three different laboratories. Here, we demonstrate that oral treatment with RD2 significantly reduced cognitive deficits in cognitively impaired aged Beagle dogs even beyond the treatment end, which suggests in combination with the treatment dependent CSF tau oligomer decrease a disease-modifying effect of RD2 treatment.
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Affiliation(s)
- Janine Kutzsche
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Sarah Schemmert
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Tuyen Bujnicki
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Christian Zafiu
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | | | - Victoria Kraemer-Schulien
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Marlene Pils
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- attyloid GmbH, Düsseldorf, Germany
| | - Lara Blömeke
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Julia Post
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Andreas Kulawik
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Dagmar Jürgens
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | | | | | - Oliver Bannach
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
- attyloid GmbH, Düsseldorf, Germany
| | - Markus Otto
- Institute of Experimental Neurology, Ulm University Hospital, Ulm, Germany
| | | | - Antje Willuweit
- Institute of Neuroscience and Medicine, Medical Imaging Physics (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - Dieter Willbold
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
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de Rivera C, Prenderville J, Araujo JA. Age‐related changes in clinically relevant biomarkers in a Beagle model of Alzheimer’s disease. Alzheimers Dement 2022. [DOI: 10.1002/alz.069443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Araujo JA, Segarra S, Mendes J, Paradis A, Brooks M, Thevarkunnel S, Milgram NW. Sphingolipids and DHA Improve Cognitive Deficits in Aged Beagle Dogs. Front Vet Sci 2022; 9:646451. [PMID: 35909696 PMCID: PMC9329143 DOI: 10.3389/fvets.2022.646451] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
Canine cognitive dysfunction syndrome (CDS) is a disorder found in senior dogs that is typically defined by the development of specific behavioral signs which are attributed to pathological brain aging and no other medical causes. One way of objectively characterizing CDS is with the use of validated neuropsychological test batteries in aged Beagle dogs, which are a natural model of this condition. This study used a series of neuropsychological tests to evaluate the effectiveness of supplementation with a novel lipid extract containing porcine brain-derived sphingolipids (Biosfeen®) and docosahexaenoic acid (DHA) for attenuating cognitive deficits in aged Beagles. Two groups (n = 12), balanced for baseline cognitive test performance, received a daily oral dose of either test supplement, or placebo over a 6-month treatment phase. Cognitive function was evaluated using the following tasks: delayed non-matching to position (DNMP), selective attention, discrimination learning retention, discrimination reversal learning, and spatial discrimination acquisition and reversal learning. The effect of the supplement on brain metabolism using magnetic resonance spectroscopy (MRS) was also examined. A significant decline (p = 0.02) in DNMP performance was seen in placebo-treated dogs, but not in dogs receiving the supplement, suggesting attenuation of working memory performance decline. Compared to placebo, the supplemented group also demonstrated significantly improved (p = 0.01) performance on the most difficult pattern of the spatial discrimination task and on reversal learning of the same pattern (p = 0.01), potentially reflecting improved spatial recognition and executive function, respectively. MRS revealed a significant increase (p = 0.048) in frontal lobe glutamate and glutamine in the treatment group compared to placebo, indicating a physiological change which may be attributed to the supplement. Decreased levels of glutamate and glutamine have been correlated with cognitive decline, suggesting the observed increase in these metabolites might be linked to the positive cognitive effects found in the present study. Results of this study suggest the novel lipid extract may be beneficial for counteracting age-dependent deficits in Beagle dogs and supports further investigation into its use for treatment of CDS. Additionally, due to parallels between canine and human aging, these results might also have applicability for the use of the supplement in human cognitive health.
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Affiliation(s)
| | - Sergi Segarra
- R&D Bioiberica S.A.U., Esplugues de Llobregat, Barcelona, Spain
- *Correspondence: Sergi Segarra
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Vitek MP, Araujo JA, Fossel M, Greenberg BD, Howell GR, Rizzo SJS, Seyfried NT, Tenner AJ, Territo PR, Windisch M, Bain LJ, Ross A, Carrillo MC, Lamb BT, Edelmayer RM. Translational animal models for Alzheimer's disease: An Alzheimer's Association Business Consortium Think Tank. Alzheimers Dement (N Y) 2021; 6:e12114. [PMID: 33457489 PMCID: PMC7798310 DOI: 10.1002/trc2.12114] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/04/2020] [Accepted: 07/09/2020] [Indexed: 12/12/2022]
Abstract
Over 5 million Americans and 50 million individuals worldwide are living with Alzheimer's disease (AD). The progressive dementia associated with AD currently has no cure. Although clinical trials in patients are ultimately required to find safe and effective drugs, animal models of AD permit the integration of brain pathologies with learning and memory deficits that are the first step in developing these new drugs. The purpose of the Alzheimer's Association Business Consortium Think Tank meeting was to address the unmet need to improve the discovery and successful development of Alzheimer's therapies. We hypothesize that positive responses to new therapies observed in validated models of AD will provide predictive evidence for positive responses to these same therapies in AD patients. To achieve this goal, we convened a meeting of experts to explore the current state of AD animal models, identify knowledge gaps, and recommend actions for development of next-generation models with better predictability. Among our findings, we all recognize that models reflecting only single aspects of AD pathogenesis do not mimic AD. Models or combinations of new models are needed that incorporate genetics with environmental interactions, timing of disease development, heterogeneous mechanisms and pathways, comorbidities, and other pathologies that lead to AD and related dementias. Selection of the best models requires us to address the following: (1) which animal species, strains, and genetic backgrounds are most appropriate; (2) which models permit efficient use throughout the drug development pipeline; (3) the translatability of behavioral-cognitive assays from animals to patients; and (4) how to match potential AD therapeutics with particular models. Best practice guidelines to improve reproducibility also need to be developed for consistent use of these models in different research settings. To enhance translational predictability, we discuss a multi-model evaluation strategy to de-risk the successful transition of pre-clinical drug assets to the clinic.
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Affiliation(s)
| | | | | | | | | | | | - Nicholas T. Seyfried
- Departments of Biochemistry and NeurologyEmory School of MedicineAtlantaGeorgiaUSA
| | - Andrea J. Tenner
- Department of Molecular Biology and BiochemistryUniversity of CaliforniaIrvineCaliforniaUSA
| | | | | | - Lisa J. Bain
- Independent Science and Medical WriterElversonPennsylvaniaUSA
| | - April Ross
- Former Alzheimer's Association EmployeeChicagoIllinoisUSA
| | | | - Bruce T. Lamb
- Indiana University School of MedicineStark Neurosciences Research InstituteIndianapolisIndianaUSA
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Baranowski DC, Buchanan B, Dwyer HC, Gabriele JP, Kelly S, Araujo JA. Penetration and efficacy of transdermal NSAIDs in a model of acute joint inflammation. J Pain Res 2018; 11:2809-2819. [PMID: 30519083 PMCID: PMC6239099 DOI: 10.2147/jpr.s177967] [Citation(s) in RCA: 9] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Purpose Prescription and OTC non-steroidal anti-inflammatory drugs (NSAIDs) are ubiquitous treatments for pain and inflammation; however, oral administration of these drugs may produce gastrointestinal (GI) side effects. Transdermal (TD) administration of NSAIDs circumvents these adverse events by avoiding the GI tract and, presumably, achieves regional drug levels of therapeutic effect and thereby, fewer off-target complications. Methods A drug quantification method was developed for ibuprofen and celecoxib in canine plasma and synovial fluid using liquid chromatography and mass spectrometry. This method was employed to evaluate the penetrance of ibuprofen and celecoxib topical formulations in dogs. Effectiveness of these topical NSAID formulations was compared to the equivalent oral drug concentration in a canine sodium-urate model of acute joint inflammation. In this model, pain was quantified using a modified Canine Brief Pain Inventory questionnaire and regional inflammation using joint caliper measurements; the significance of intervention was evaluated using linear mixed models for repeated measures along with Bonferroni corrections. Results After seven days of chronic topical administration, Delivra™ (DEL) formulations of ibuprofen and celecoxib generated serum levels of 2.9µg/mL and 220ng/mL and synovial fluid levels of 1.8 µg/mL and 203 ng/mL (respectively). In the canine model of acute inflammation, the overall treatment effects as well as the treatment by time interactions were strongly significant (P<0.001) for both drugs. Oral ibuprofen proved uniquely effective at the earliest time point, while all ibuprofen formulations were effective at treating pain at 8.5 and 24.5 hours post-induction. Similarly, all celecoxib formulations (oral and topical) were equally effective at 8.5 and 24.5 hours post-induction. Conclusion DEL formulations of ibuprofen and celecoxib successfully introduced these NSAIDs into synovial fluid at concentrations similar to those observed in circulation. Furthermore, these formulations reduced symptoms of pain associated with acute inflammation. Oral and transdermally delivered NSAIDs have similar pain relief effects; therefore, a replacement or combinatorial treatment may provide a more stable pain relief profile. In conclusion, this work supports further investigation of TD products in the treatment of regional inflammatory events.
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Affiliation(s)
| | - Beth Buchanan
- Department of Research and Development, Delivra Corp., Charlottetown, PE, Canada,
| | - Heather C Dwyer
- Department of Research and Development, Delivra Corp., Charlottetown, PE, Canada,
| | - Joseph P Gabriele
- Department of Research and Development, Delivra Corp., Charlottetown, PE, Canada,
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Borghys H, Van Broeck B, Dhuyvetter D, Jacobs T, de Waepenaert K, Erkens T, Brooks M, Thevarkunnel S, Araujo JA. Young to Middle-Aged Dogs with High Amyloid-β Levels in Cerebrospinal Fluid are Impaired on Learning in Standard Cognition tests. J Alzheimers Dis 2018; 56:763-774. [PMID: 28035921 PMCID: PMC5271428 DOI: 10.3233/jad-160434] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 11/15/2022]
Abstract
Understanding differences in Alzheimer’s disease biomarkers before the pathology becomes evident can contribute to an improved understanding of disease pathogenesis and treatment. A decrease in amyloid-β (Aβ)42 in cerebrospinal fluid (CSF) is suggested to be a biomarker for Aβ deposition in brain. However, the relevance of CSF Aβ levels prior to deposition is not entirely known. Dogs are similar to man with respect to amyloid-β protein precursor (AβPP)-processing, age-related amyloid plaque deposition, and cognitive dysfunction. In the current study, we evaluated the relation between CSF Aβ42 levels and cognitive performance in young to middle-aged dogs (1.5–7 years old). Additionally, CSF sAβPPα and sAβPPβ were measured to evaluate AβPP processing, and CSF cytokines were measured to determine the immune status of the brain. We identified two groups of dogs showing consistently low or high CSF Aβ42 levels. Based on prior studies, it was assumed that at this age no cerebral amyloid plaques were likely to be present. The cognitive performance was evaluated in standard cognition tests. Low or high Aβ concentrations coincided with low or high sAβPPα, sAβPPβ, and CXCL-1 levels, respectively. Dogs with high Aβ concentrations showed significant learning impairments on delayed non-match to position (DNMP), object discrimination, and reversal learning compared to dogs with low Aβ concentrations. Our data support the hypothesis that high levels of CSF Aβ in dogs coincide with lower cognitive performance prior to amyloid deposition. Further experiments are needed to investigate this link, as well as the relevance with respect to Alzheimer’s disease pathology progression.
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Affiliation(s)
- Herman Borghys
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Bianca Van Broeck
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Deborah Dhuyvetter
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Tom Jacobs
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Katja de Waepenaert
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Tim Erkens
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
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Campbell MC, Kisilak ML, DeVries D, Cookson C, Hamel M, Chow T, Hunter JJ, Brooks M, Strazzeri J, Fischer W, DiVincenti L, Araujo JA, Mackenzie I, Ran C, Emptage L. O3‐12‐05: Amyloid as a Biomarker of Alzheimer's Disease in Post‐Mortem Retinas in Human and Dog Models of Alzheimer's Disease. Alzheimers Dement 2016. [DOI: 10.1016/j.jalz.2016.06.577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | - Chongzhao Ran
- Massachusetts General Hospital and Harvard Medical SchoolBostonMA USA
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8
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Landsberg GM, Beck A, Lopez A, Deniaud M, Araujo JA, Milgram NW. Dog-appeasing pheromone collars reduce sound-induced fear and anxiety in beagle dogs: a placebo-controlled study. Vet Rec 2015; 177:260. [PMID: 26311736 PMCID: PMC4602264 DOI: 10.1136/vr.103172] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [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] [Accepted: 07/27/2015] [Indexed: 11/19/2022]
Abstract
The objective of the study was to assess the effects of a dog-appeasing pheromone (DAP) collar in reducing sound-induced fear and anxiety in a laboratory model of thunderstorm simulation. Twenty-four beagle dogs naïve to the current test were divided into two treatment groups (DAP and placebo) balanced on their fear score in response to a thunderstorm recording. Each group was then exposed to two additional thunderstorm simulation tests on consecutive days. Dogs were video-assessed by a trained observer on a 6-point scale for active, passive and global fear and anxiety (combined). Both global and active fear and anxiety scores were significantly improved during and following thunder compared with placebo on both test days. DAP significantly decreased global fear and anxiety across ‘during’ and ‘post’ thunder times when compared with baseline. There was no significant improvement in the placebo group from baseline on the test days. In addition, the DAP group showed significantly greater use of the hide box at any time with increased exposure compared with the placebo group. The DAP collar reduced the scores of fear and anxiety, and increased hide use in response to a thunder recording, possibly by counteracting noise-related increased reactivity.
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Affiliation(s)
- G M Landsberg
- North Toronto Veterinary Behaviour Specialty Clinic, 99 Henderson Ave., Thornhill, Ontario, Canada L3T2K9 CanCog Technologies, 120 Carlton St., Suite 204, Toronto, Ontario, Canada M5A 4K2
| | - A Beck
- Ceva Santé Animale, 10 Avenue La Ballastiere, Libourne 33500, France
| | - A Lopez
- Ceva Santé Animale, 10 Avenue La Ballastiere, Libourne 33500, France
| | - M Deniaud
- MDStat Consulting, 11 rue damonville, Melun 77000, France
| | - J A Araujo
- InterVivo Solutions, 120 Carlton St., Suite 203, Toronto, Ontario, Canada M5A 4K2
| | - N W Milgram
- CanCog Technologies, 120 Carlton St., Suite 204, Toronto, Ontario, Canada M5A 4K2
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Araujo JA, Borghys H, Brooks M, Broeck B, Dhuyvetter D. P4‐179: Young to middle‐aged dogs with high basal Aβ42 CSF level demonstrate learning impairment compared to dogs with low basal CSF Aβ42. Alzheimers Dement 2015. [DOI: 10.1016/j.jalz.2015.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Margolin RA, Araujo JA, Sheinerman K, Epps D. P4‐280: Maximizing the potential of small companies in Alzheimer's disease research: Challenges and opportunities. Alzheimers Dement 2015. [DOI: 10.1016/j.jalz.2015.08.110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mongillo P, Araujo JA, Pitteri E, Carnier P, Adamelli S, Regolin L, Marinelli L. Spatial reversal learning is impaired by age in pet dogs. Age (Dordr) 2013; 35:2273-82. [PMID: 23529504 PMCID: PMC3824977 DOI: 10.1007/s11357-013-9524-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 03/08/2013] [Indexed: 05/18/2023]
Abstract
Aged dogs spontaneously develop progressive decline in both cognitive and behavioral function, in addition to neuropathological changes, that collectively parallel several aspects of human aging and Alzheimer's disease progression and likely contribute to the development of canine cognitive dysfunction syndrome. In the current study, ethologically relevant spatial learning, retention, and reversal learning tasks were conducted, with the goal of expanding canine neuropsychological testing to pet dogs. Initially, dogs (N = 44, aged 7.8 ± 2.8 years, mean ± SD) had to learn which of two alternative routes successfully led out of a T-maze. Two weeks later, long-term memory retention was assessed, immediately followed by a reversal learning task in which the previously correct route out of the maze was reversed compared with the initial learning and memory retention tasks. No effects of age were evident on the learning or retention tasks. However, older (≥ 8 years) dogs were significantly impaired on the reversal learning task compared with younger ones (< 8 years). Moreover, trial response latency was significantly increased in aged dogs across both the initial and reversal learning tasks but not on the retention task, which suggests that processing speed was impaired by increasing age during the acquisition of novel spatial information but not during performance of previously learned responses. Overall, the current study provides a framework for assessing cognitive function in pet dogs, which should improve understanding of the effects of aging on cognition in the dog population.
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Affiliation(s)
- Paolo Mongillo
- Dipartimento di Biomedicina Comparata e Alimentazione, Università degli Studi di Padova, Padua, Italy,
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Araujo JA, de Rivera C, Landsberg GM, Adams PE, Milgram NW. Development and validation of a novel laboratory model of sound-induced fear and anxiety in Beagle dogs. J Vet Behav 2013. [DOI: 10.1016/j.jveb.2012.10.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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DePorter TL, Landsberg GM, Araujo JA, Ethier JL, Bledsoe DL. Harmonease Chewable Tablets reduces noise-induced fear and anxiety in a laboratory canine thunderstorm simulation: A blinded and placebo-controlled study. J Vet Behav 2012. [DOI: 10.1016/j.jveb.2011.05.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Landsberg GM, Deporter T, Araujo JA. Clinical signs and management of anxiety, sleeplessness, and cognitive dysfunction in the senior pet. Vet Clin North Am Small Anim Pract 2012; 41:565-90. [PMID: 21601747 DOI: 10.1016/j.cvsm.2011.03.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Physical signs of old age may be obvious, but mental and cognitive changes require more careful observation. Changes in behavior may represent the earliest indications of medical problems, or disorders of the central nervous system, and these may be bidirectional. Cognitive dysfunction syndrome is underdiagnosed and affects a substantial portion of aged companion animals. This article describes potential treatment regimens to address age-related behavioral problems, as well as a framework for investigating differential diagnoses. Early identification of changes in behavior is essential for the adequate treatment and management of medical and behavioral problems, and for monitoring outcomes.
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Affiliation(s)
- Gary M Landsberg
- North Toronto Animal Clinic, 99 Henderson Avenue, Thornhill, ON L3T 2K9, Canada.
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16
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Snigdha S, Christie LA, De Rivera C, Araujo JA, Milgram NW, Cotman CW. Age and distraction are determinants of performance on a novel visual search task in aged Beagle dogs. Age (Dordr) 2012; 34:67-73. [PMID: 21336566 PMCID: PMC3260365 DOI: 10.1007/s11357-011-9219-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 02/06/2011] [Indexed: 05/18/2023]
Abstract
Aging has been shown to disrupt performance on tasks that require intact visual search and discrimination abilities in human studies. The goal of the present study was to determine if canines show age-related decline in their ability to perform a novel simultaneous visual search task. Three groups of canines were included: a young group (N = 10; 3 to 4.5 years), an old group (N = 10; 8 to 9.5 years), and a senior group (N = 8; 11 to 15.3 years). Subjects were first tested for their ability to learn a simple two-choice discrimination task, followed by the visual search task. Attentional demands in the task were manipulated by varying the number of distracter items; dogs received an equal number of trials with either zero, one, two, or three distracters. Performance on the two-choice discrimination task varied with age, with senior canines making significantly more errors than the young. Performance accuracy on the visual search task also varied with age; senior animals were significantly impaired compared to both the young and old, and old canines were intermediate in performance between young and senior. Accuracy decreased significantly with added distracters in all age groups. These results suggest that aging impairs the ability of canines to discriminate between task-relevant and -irrelevant stimuli. This is likely to be derived from impairments in cognitive domains such as visual memory and learning and selective attention.
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Affiliation(s)
- Shikha Snigdha
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, 1226 Gillespie NRF, Irvine, CA 92697-4540, USA.
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Araujo JA, Greig NH, Ingram DK, Sandin J, de Rivera C, Milgram NW. Cholinesterase inhibitors improve both memory and complex learning in aged beagle dogs. J Alzheimers Dis 2012; 26:143-55. [PMID: 21593569 DOI: 10.3233/jad-2011-110005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [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]
Abstract
Similar to patients with Alzheimer's disease (AD), dogs exhibit age-dependent cognitive decline, amyloid-β (Aβ) pathology, and evidence of cholinergic hypofunction. The present study sought to further investigate the role of cholinergic hypofunction in the canine model by examining the effect of the cholinesterase inhibitors phenserine and donepezil on performance of two tasks, a delayed non-matching-to-position task (DNMP) designed to assess working memory, and an oddity discrimination learning task designed to assess complex learning, in aged dogs. Phenserine (0.5 mg/kg; PO) significantly improved performance on the DNMP at the longest delay compared to wash-out and partially attenuated scopolamine-induced deficits (15 μg/kg; SC). Phenserine also improved learning on a difficult version of an oddity discrimination task compared to placebo, but had no effect on an easier version. We also examined the effects of three doses of donepezil (0.75, 1.5, and 6 mg/kg; PO) on performance of the DNMP. Similar to the results with phenserine, 1.5 mg/kg of donepezil improved performance at the longest delay compared to baseline and wash-out, indicative of memory enhancement. These results further extend the findings of cholinergic hypofunction in aged dogs and provide pharmacological validation of the canine model with a cholinesterase inhibitor approved for use in AD. Collectively, these studies support utilizing the aged dog in future screening of therapeutics for AD, as well as for investigating the links among cholinergic function, Aβ pathology, and cognitive decline.
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Affiliation(s)
- Joseph A Araujo
- Department of Pharmacology, University of Toronto, Toronto, ON, Canada.
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Collison KS, Zaidi MZ, Saleh SM, Makhoul NJ, Inglis A, Burrows J, Araujo JA, Al-Mohanna FA. Nutrigenomics of hepatic steatosis in a feline model: effect of monosodium glutamate, fructose, and Trans-fat feeding. Genes Nutr 2011; 7:265-80. [PMID: 22144172 DOI: 10.1007/s12263-011-0261-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 11/19/2011] [Indexed: 01/06/2023]
Abstract
Nonalcoholic fatty liver disease begins with a relatively benign hepatic steatosis, often associated with increased adiposity, but may progress to a more severe nonalcoholic steatohepatitis with inflammation. A subset of these patients develops progressive fibrosis and ultimately cirrhosis. Various dietary components have been shown to contribute to the development of liver disease, including fat, sugars, and neonatal treatment with high doses of monosodium glutamate (MSG). However, rodent models of progressive disease have been disappointing, and alternative animal models of diet-induced liver disease would be desirable, particularly if they contribute to our knowledge of changes in gene expression as a result of dietary manipulation. The domestic cat has previously been shown to be an appropriate model for examining metabolic changes-associated human diseases such as diabetes. Our aim was therefore to compare changes in hepatic gene expression induced by dietary MSG, with that of a diet containing Trans-fat and high fructose corn syrup (HFCS), using a feline model. MSG treatment increased adiposity and promoted hepatic steatosis compared to control (P < 0.05). Exposure to Trans-fat and HFCS promoted hepatic fibrosis and markers of liver dysfunction. Affymetrix microarray analysis of hepatic gene expression showed that dietary MSG promoted the expression of genes involved in cholesterol and steroid metabolism. Conversely, Trans-fat and HFCS feeding promoted the expression of genes involved in lipolysis, glycolysis, liver damage/regeneration, and fibrosis. Our feline model examining gene-diet interactions (nutrigenomics) demonstrates how dietary MSG, Trans-fat, and HFCS may contribute to the development of hepatic steatosis.
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Affiliation(s)
- Kate S Collison
- Cell Biology and Diabetes Research Unit, Department of Biological and Medical Research, MBC 03, King Faisal Specialist Hospital and Research Centre, P. O. Box 3354, Riyadh, 11211, Saudi Arabia,
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Araujo JA, Nobrega JN, Raymond R, Milgram NW. Aged dogs demonstrate both increased sensitivity to scopolamine impairment and decreased muscarinic receptor density. Pharmacol Biochem Behav 2011; 98:203-9. [DOI: 10.1016/j.pbb.2011.01.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 12/22/2010] [Accepted: 01/07/2011] [Indexed: 11/29/2022]
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Abstract
PRACTICAL RELEVANCE Cognitive dysfunction syndrome (CDS) is a widely accepted diagnosis in dogs, with established treatment options. In cats, however, our understanding of cognitive dysfunction is still being shaped by ongoing research in the field, and limited treatment options are available. Recent clinical studies indicate that old age in the cat is accompanied by increased behavioural signs such as wandering, vocalization and night-time activity that are not attributable to identifiable medical problems. It is essential, therefore, that veterinarians include behavioural well-being in the routine care of senior cats. PATIENT GROUP While the exact age of onset is not established, studies suggest that age-related behavioural changes consistent with cognitive dysfunction are prevalent in cats as early as 10 years of age and that prevalence increases significantly in older cats. CLINICAL CHALLENGES The diagnosis of cognitive dysfunction requires the identification of geriatric behavioural changes that are not caused by other medical problems, although the two may not be mutually exclusive. Therefore, the practitioner must rely heavily on owner reports and history to ensure prompt diagnosis and treatment. The absence of any approved dietary or pharmaceutical interventions for cognitive dysfunction adds a further challenge, although several possibilities exist. EVIDENCE BASE This article draws on recent research that has produced neuropathological, cognitive and behavioural evidence for cognitive dysfunction in aging cats. As an impetus to further our understanding of this disease and potential treatment options, the authors propose a behavioural checklist that might aid in the clinical diagnosis of feline CDS and discuss treatment options that have proven successful in the canine counterpart of this disease.
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Affiliation(s)
- Gary M Landsberg
- North Toronto Animal Clinic, Thornhill, Ontario L3T 2K9, Canada.
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Araujo JA, de Rivera C, Ethier JL, Landsberg GM, Denenberg S, Arnold S, Milgram NW. ANXITANE® tablets reduce fear of human beings in a laboratory model of anxiety-related behavior. J Vet Behav 2010. [DOI: 10.1016/j.jveb.2010.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Rivera C, Araujo JA, Milgram NW. P4‐271: A
β
40 And A
β
42 Levels In Dog Cerebrospinal Fluid. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.07.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Christina Rivera
- University of TorontoTorontoONCanada
- CanCog Technologies Inc.TorontoONCanada
| | - Joseph A. Araujo
- University of TorontoTorontoONCanada
- CanCog Technologies Inc.TorontoONCanada
| | - Norton W. Milgram
- University of TorontoTorontoONCanada
- CanCog Technologies Inc.TorontoONCanada
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Rivera C, Araujo JA, Dobson H, Zicker S, Milgram NW. IC‐P1‐016: Fractional anisotropy increases with development and is correlated with cognitive function in the beagle dog. Alzheimers Dement 2008. [DOI: 10.1016/j.jalz.2008.05.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Christina Rivera
- CanCog Technologies Inc.TorontoONCanada
- University of TorontoTorontoONCanada
| | - Joseph A. Araujo
- CanCog Technologies Inc.TorontoONCanada
- University of TorontoTorontoONCanada
| | - Howard Dobson
- CanCog Technologies Inc.TorontoONCanada
- University of GuelphGuelphONCanada
| | | | - Norton W. Milgram
- CanCog Technologies Inc.TorontoONCanada
- University of TorontoTorontoONCanada
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Rivera C, Araujo JA, Howard D, Zicker S, Milgram NW. P1‐009: Fractional anisotropy increases with development and is correlated with cognitive function in the Beagle dog. Alzheimers Dement 2008. [DOI: 10.1016/j.jalz.2008.05.594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Christina Rivera
- CanCog Technologies Inc.TorontoONCanada
- University of TorontoTorontoONCanada
| | - Joseph A. Araujo
- CanCog Technologies Inc.TorontoONCanada
- University of TorontoTorontoONCanada
| | - Dobson Howard
- CanCog Technologies Inc.TorontoONCanada
- University of GuelphGuelphONCanada
| | | | - Norton W. Milgram
- CanCog Technologies Inc.TorontoONCanada
- University of TorontoTorontoONCanada
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Araujo JA, Landsberg GM, Milgram NW, Miolo A. Improvement of short-term memory performance in aged beagles by a nutraceutical supplement containing phosphatidylserine, Ginkgo biloba, vitamin E, and pyridoxine. Can Vet J 2008; 49:379-385. [PMID: 18481547 PMCID: PMC2275342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Aged dogs demonstrate cognitive decline that is linked to brain aging. The purpose of the present study was to examine if a commercially available nutraceutical supplement that may be neuroprotective and contains phosphatidylserine, Ginkgo biloba, vitamin E, and pyridoxine could improve cognitive function in aged beagles. Nine aged beagles were tested on performance on a delayed-non-matching-to-position task, which is a neuropsychological test of short-term visuospatial memory. All subjects were tested on 5 baseline sessions; then, to assess the supplement, a crossover design was used in which 1 group received the supplement and the other a control substance in the 1st phase, with treatment conditions being reversed in the 2nd phase. Performance accuracy was significantly improved in supplemented dogs compared with control dogs and the effect was long lasting. These findings suggest that the nutraceutical supplement can improve memory in aged dogs.
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Affiliation(s)
- Joseph A Araujo
- Department of Pharmacology, University of Toronto, 1 King's College Circle, Toronto, Ontario.
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Kleinman MT, Araujo JA, Nel A, Sioutas C, Campbell A, Cong PQ, Li H, Bondy SC. Inhaled ultrafine particulate matter affects CNS inflammatory processes and may act via MAP kinase signaling pathways. Toxicol Lett 2008; 178:127-30. [PMID: 18420360 DOI: 10.1016/j.toxlet.2008.03.001] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 03/01/2008] [Accepted: 03/01/2008] [Indexed: 01/29/2023]
Abstract
In addition to evidence that inhalation of ambient particulate matter (PM) can increase cardiopulmonary morbidity and mortality, the brain may also constitute a site adversely effected by the environmental presence of airborne particulate matter. We have examined the association between exposure to PM and adverse CNS effects in apolipoprotein E knockout (ApoE-/-) mice exposed to two levels of concentrated ultrafine particulate matter in central Los Angeles. Mice were euthanized 24h after the last exposure and brain, liver, heart, lung and spleen tissues were collected and frozen for subsequent bioassays. There was clear evidence of aberrant immune activation in the brains of exposed animals as judged by a dose-related increase in nuclear translocation of two key transcription factors, NF-kappaB and AP-1. These factors are involved in the promotion of inflammation. Increased levels of glial fibrillary acidic protein (GFAP) were also found consequent to particulate inhalation suggesting that glial activation was taking place. In order to determine the mechanism by which these events occurred, levels of several MAP kinases involved in activation of these transcription factors were assayed by Western blotting. There were no significant changes in the proportion of active (phosphorylated) forms of ERK-1, IkB and p38. However, the fraction of JNK in the active form was significantly increased in animals receiving the lower concentration of concentrated ambient particles (CAPs). This suggests that the signaling pathway by which these transcription factors are activated involves the activation of JNK.
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Affiliation(s)
- M T Kleinman
- Department of Community and Environmental Medicine, University of California-Irvine, Irvine, CA 92697, USA
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Milgram NW, Araujo JA, Hagen TM, Treadwell BV, Ames BN. Acetyl-L-carnitine and alpha-lipoic acid supplementation of aged beagle dogs improves learning in two landmark discrimination tests. FASEB J 2007; 21:3756-62. [PMID: 17622567 DOI: 10.1096/fj.07-8531com] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Beagle dogs between 7.6 and 8.8 years of age administered a twice daily supplement of alpha-lipoic acid (LA) and acetyl-L-carnitine (ALC) over approximately 2 months made significantly fewer errors in reaching the learning criterion on two landmark discrimination tasks compared to controls administered a methylcellulose placebo. Testing started after a 5 day wash-in. The dogs were also tested on a variable delay version of a previously acquired spatial memory task; results were not significant. The improved performance on the landmark task of dogs supplemented with LA + ALC provides evidence of the effectiveness of this supplement in improving discrimination and allocentric spatial learning. We suggest that long-term maintenance on LA and ALC may be effective in attenuating age-associated cognitive decline by slowing the rate of mitochondrial decay and cellular aging.
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Affiliation(s)
- N W Milgram
- University of Toronto, Division of Life Sciences, Scarborough, Ontario, Canada.
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Studzinski CM, Christie LA, Araujo JA, Burnham WM, Head E, Cotman CW, Milgram NW. Visuospatial function in the beagle dog: An early marker of cognitive decline in a model of human aging and dementia. Neurobiol Learn Mem 2006; 86:197-204. [PMID: 16616528 DOI: 10.1016/j.nlm.2006.02.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 01/26/2006] [Accepted: 02/26/2006] [Indexed: 11/25/2022]
Abstract
Visuospatial learning and memory impairments are an early marker for age-related cognitive decline and Alzheimer's disease. Similar to humans, aged dogs show visuospatial learning and memory deficits (). One hundred and nine beagle dogs ranging between 0.25 and 11.99 years were tested on a visuospatial delayed non-matching to position (DNMP) task to better characterize the progression of visuospatial deficits in the dog. Age predicted 48.2% of the variability in learning the DNMP, with dogs ranging from 1 to 11.99 years generally making more errors with increasing age. By contrast, puppies (<1 year) likely were showing developmental deficits, possibly due to an immature prefrontal cortex. Mild visuospatial deficits were detected by 6 years, which precedes the typical onset of amyloid-beta (Abeta) accumulation in the dog brain by two years, and can serve as an early marker for cognitive decline in the dog. These findings suggest that (1) age-related changes in visuospatial function in the dog models that seen in humans, further validating the dog as a model for human aging and dementia; and (2) other mechanisms, such as oxidative stress, soluble Abeta oligomers or cholinergic deficits, are likely contributing to the early impairment.
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Affiliation(s)
- Christa M Studzinski
- Department of Pharmacology, University of Toronto, 1265 Military Trail, Scarborough, Ont., Canada M1C 1A4.
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Henderson ST, Studzinski CM, Araujo JA, Milgram NW, Larson B. P4–382: Beneficial effects of AC1203 in a dog model of human aging and dementia. Alzheimers Dement 2006. [DOI: 10.1016/j.jalz.2006.05.2123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Araujo JA, Nobrega JN, Raymond R, Milgram NW. P2–007: Functional and physiological cholinergic deficits in the aged dog: Extending the canine model of dementia and Alzheimer's disease. Alzheimers Dement 2006. [DOI: 10.1016/j.jalz.2006.05.844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Joseph A. Araujo
- University of TorontoTorontoONCanada
- CanCog Technologies IncTorontoONCanada
| | | | | | - Norton W. Milgram
- University of TorontoTorontoONCanada
- CanCog Technologies IncTorontoONCanada
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Abstract
Aging pets often suffer a decline in cognitive function (eg, memory,learning, perception, awareness) likely associated with age-dependent brain alterations. Clinically, cognitive dysfunction may result in various behavioral signs, including disorientation; forgetting of previously learned behaviors, such as house training; alterations in the manner in which the pet interacts with people or other pets;onset of new fears and anxiety; decreased recognition of people, places, or pets; and other signs of deteriorating memory and learning ability. Many medical problems, including other forms of brain pathologic conditions, can contribute to these signs. The practitioner must first determine the cause of the behavioral signs and then determine an appropriate course of treatment, bearing in mind the constraints of the aging process. A diagnosis of cognitive dysfunction syndrome is made once other medical and behavioral causes are ruled out.
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Affiliation(s)
- Gary Landsberg
- Doncaster Animal Clinic, 99 Henderson Avenue, Thornhill, Ontario L3T2K9, Canada.
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Christie LA, Studzinski CM, Araujo JA, Leung CSK, Ikeda-Douglas CJ, Head E, Cotman CW, Milgram NW. A comparison of egocentric and allocentric age-dependent spatial learning in the beagle dog. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:361-9. [PMID: 15795044 DOI: 10.1016/j.pnpbp.2004.12.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/13/2004] [Indexed: 10/25/2022]
Abstract
Spatial discriminations can be performed using either egocentric information based on body position or allocentric information based on the position of landmarks in the environment. Beagle dogs ranging from 2 to 16 years of age were tested for their ability to learn a novel egocentric spatial discrimination task that used two identical blocks paired in three possible spatial positions (i.e. left, center and right). Dogs were rewarded for responding to an object furthest to either their left or right side. Therefore, when the center location was used, it was correct on half of the trials and incorrect on the other half. Upon successful acquisition of the task, the reward contingencies were reversed, and the dogs were rewarded for responding to the opposite side. A subset of dogs was also tested on an allocentric spatial discrimination task, landmark discrimination. Egocentric spatial reversal learning and allocentric discrimination learning both showed a significant age-dependent decline, while initial egocentric learning appeared to be age-insensitive. Intra-subject correlation analyses revealed a significant relationship between egocentric reversal learning and allocentric learning. However, the correlation only accounted for a small proportion of the variance, suggesting that although there might be some common mechanism underlying acquisition of the two tasks, additional unique neural substrates were involved depending on whether allocentric or egocentric spatial information processing was required.
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Affiliation(s)
- Lori-Ann Christie
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
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Tapp PD, Chu Y, Araujo JA, Chiou JY, Head E, Milgram NW, Su MY. Effects of scopolamine challenge on regional cerebral blood volume. A pharmacological model to validate the use of contrast enhanced magnetic resonance imaging to assess cerebral blood volume in a canine model of aging. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:399-406. [PMID: 15795048 DOI: 10.1016/j.pnpbp.2004.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/13/2004] [Indexed: 11/17/2022]
Abstract
Cognitive impairment resulting from disruption of cholinergic function may occur through modulation of cerebrovascular volume (CBV). In the present study, dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) was used to examine cerebrovascular volume in young and old dogs during baseline and after administration of a cholinergic antagonist (scopolamine). In the first study, 24 animals (2-15 years of age) were given a baseline scan followed by a second scan after scopolamine administration (30 microg/kg). Gray matter rCBV was significantly higher than white matter rCBV during baseline and scopolamine administration. In the second study a subset of 7 dogs (4 young and 3 old) received scopolamine before anesthesia was induced for a second DSC-MRI scan. Consistent with the first study, gray matter rCBV was significantly higher than white matter rCBV. Scopolamine administered before anesthesia however, resulted in higher rCBV values compared to baseline in cerebral gray matter. Additionally, rCBVs were higher in young dogs at baseline in gray and white matter and marginally higher in gray matter when scopolamine was administered before anesthesia. These results indicate that in the dog, rCBV varies with brain compartment, decreases with age, and that DSC-MRI provides a measure of cerebrovascular function which may be related to age-dependent changes in cognition, brain structure, and neuropathology.
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Affiliation(s)
- P Dwight Tapp
- John Tu and Thomas Yuen Center for Functional Onco-imaging, University of California, 164 Irvine Hall, Irvine, CA, USA
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Studzinski CM, Araujo JA, Milgram NW. The canine model of human cognitive aging and dementia: pharmacological validity of the model for assessment of human cognitive-enhancing drugs. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:489-98. [PMID: 15795058 DOI: 10.1016/j.pnpbp.2004.12.014] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/13/2004] [Indexed: 01/24/2023]
Abstract
For the past 15 years we have investigated the aged beagle dog as a model for human aging and dementia. We have shown that dogs develop cognitive deficits and neuropathology seen in human aging and dementia. These similarities increase the likelihood that the model will be able to accurately predict the efficacy of Alzheimer's disease (AD) treatments as well as detect therapeutics with limited or no efficacy. Better predictive validity of cognitive-enhancing therapeutics (CETs) could lead to enormous cost savings by reducing the number of failed human clinical trials and also may reduce the likelihood of negative outcomes such as those recently observed in the AN-1792 clinical trials. The current review assesses the pharmacological validity of the canine model of human aging and dementia. We tested the efficacy of (1) CP-118,954 and phenserine, two acetylcholinesterase inhibitors, (2) an ampakine, (3) selegiline hydrochloride, two drugs that have failed human AD trials, and (4) adrafinil, a putative CET. Our research demonstrates that dogs not only develop isomorphic changes in human cognition and brain pathology, but also accurately predict the efficacy of known AD treatments and the absence or limited efficacy of treatments that failed clinical trials. These findings collectively support the utilization of the dog model as a preclinical screen for identifying novel CETs for both age-associated memory disorder and dementia.
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Araujo JA, Studzinski CM, Head E, Cotman CW, Milgram NW. Assessment of nutritional interventions for modification of age-associated cognitive decline using a canine model of human aging. Age (Dordr) 2005; 27:27-37. [PMID: 23598601 PMCID: PMC3456092 DOI: 10.1007/s11357-005-4001-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Accepted: 03/11/2005] [Indexed: 05/15/2023]
Abstract
The present review focuses on the utility of a canine model in evaluating nutritional interventions for age-related cognitive dysfunction. Aged dogs demonstrate progressive cognitive decline with concurrent amyloid-beta pathology that parallels the pathology observed in aging humans. Dogs, therefore, provide a natural model of human pathological aging. We have and are in the process of evaluating several nutritional-based interventions aimed at preventing cognitive decline and brain aging. In a three-year longitudinal study, we examined the effects of a diet enriched with antioxidants and mitochondrial cofactors on several measures of cognition and brain aging. Compared to controls, aged dogs on the enriched diet demonstrated both short- and long-term cognitive benefits, as well decreased deposition of amyloid-beta protein. The diet also reduced behavioral signs associated with canine Cognitive Dysfunction Syndrome when assessed in veterinary clinical trials. We also have preliminary evidence suggesting a beneficial effect of a proprietary blend of docosahexaenoic acid and phospholipids on both cognitive and physiological measures. Collectively, our data indicate (1) that the dog, either in the laboratory or in the clinic, provides an important tool for assessing nutritional interventions and (2) that combination interventions aimed at several mechanisms of pathological aging may prove more effective than single nutritive components in human trials.
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Affiliation(s)
- Joseph A. Araujo
- Department of Pharmacology, University of Toronto, Toronto, Ontario Canada
| | | | - Elizabeth Head
- Institute for Brain Aging and Dementia, University of California, Irvine, California USA
| | - Carl W. Cotman
- Institute for Brain Aging and Dementia, University of California, Irvine, California USA
| | - Norton W. Milgram
- Department of Pharmacology, University of Toronto, Toronto, Ontario Canada
- Division of Life Sciences, University of Toronto at Scarborough, 1265 Military Trail, Scarborough, ON M1C 1A4 Canada
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Araujo JA, Studzinski CM, Milgram NW. Further evidence for the cholinergic hypothesis of aging and dementia from the canine model of aging. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:411-22. [PMID: 15795050 DOI: 10.1016/j.pnpbp.2004.12.008] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [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] [Accepted: 12/13/2004] [Indexed: 11/24/2022]
Abstract
Memory decline in human aging and dementia is linked to dysfunction of the cholinergic system. Aging dogs demonstrate cognitive impairments and neuropathology that models human aging and dementia. This paper reviews recent evidence suggesting cholinergic involvement in canine cognitive aging based on studies with the anti-cholinergic drug, scopolamine, and a novel acetylcholinesterase inhibitor, phenserine. In particular, we examine: (1) the cognitive specificity of scopolamine's impairment in dogs, (2) the effect of age on scopolamine impairment and (3) the effect of phenserine on cognitive performance in dogs. Our findings indicate that working memory performance is disrupted by scopolamine at doses that do not disrupt non-cognitive behavior or long-term, semantic-like, memory, as indicated by performance of previously learned discriminations. This pattern of deficits is also seen in human and canine aging. We demonstrate that aged dogs are more sensitive to the impairing effects of scopolamine than young dogs, suggesting a decrease in cholinergic tone with increasing age. Dogs receiving phenserine demonstrate improved learning and memory compared to placebo controls. Our findings suggest that cholinergic decline could result in memory impairment, but that the memory impairment may be secondary to deficits in attention and/or encoding of new information. Together, these results suggest that the canine cholinergic system declines with age and that the aged dog is a unique model for screening therapeutics and for examining the relationship between amyloid pathology and cholinergic dysfunction in age-dependent cognitive decline.
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Affiliation(s)
- Joseph A Araujo
- Department of Pharmacology, University of Toronto, Ontario, Canada
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Chan JWC, Araujo JA, Zicker SC, Pun TWC, Milgram NW. Effect of feeding patterns on performance of a visuospatial memory task in the beagle dog: a novel cognitive-based protocol for assessing satiety. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:481-8. [PMID: 15795057 DOI: 10.1016/j.pnpbp.2004.12.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/13/2004] [Indexed: 10/25/2022]
Abstract
The assessment of appetite suppressing effects, or satiating effects, of drugs or other treatments is typically based on the measurement of food consumption and body weight. The present study describes a novel cognitive-based protocol for assessing satiety in the dog based on response latency and performance accuracy on a canine test of spatial working memory, the three-component delayed-non-matching-to-position task (3cDNMP). We hypothesized that satiety, produced by providing food prior to testing, would reduce motivation to respond quickly and accurately on this food-reinforced task. Dogs were first over-trained on a variable-delay version of the 3cDNMP task. They were then pre-fed with either a single or a double portion of food prior to being tested on the same task. Pre-feeding slowed response latency, but had no effect on performance accuracy. A more pronounced increase in response latency was observed in young dogs than in old dogs when offered double portions of food. These results suggest, first, that spatial working memory capability is independent of motivation; second, that satiety is age sensitive; and third, that a cognitive protocol can provide a reliable method for evaluating the satiating effects of various foods and other compounds in the dog.
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Affiliation(s)
- Joan W C Chan
- Department of Pharmacology, University of Toronto, Toronto, Canada
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Araujo JA, Studzinski CM, Larson BT, Milgram NW. Comparison of the cognitive palatability assessment protocol and the two-pan test for use in assessing palatability of two similar foods in dogs. Am J Vet Res 2004; 65:1490-6. [PMID: 15566086 DOI: 10.2460/ajvr.2004.65.1490] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [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: 11/20/2022]
Abstract
OBJECTIVE To compare preferences of dogs for 2 similar foods by use of 2 distinct methods (the cognitive palatability assessment protocol [CPAP] and the 2-pan test). ANIMALS 13 Beagles. PROCEDURE 6 dogs were trained in a 3-choice object-discrimination-learning task in which their nonpreferred objects were associated with a reward of a lamb-based or chicken-based food. The number of choices for each object was used to determine food preferences. Preference of the same foods was also assessed by use of a 2-pan test in which all 13 dogs were provided the 2 foods in identical bowls. The amount of each food consumed in 10 minutes was used to determine food preference. RESULTS All dogs had a noticeable preference for the chicken-based food during the CPAP. Once established, preferences remained consistent and were not affected by satiety. The 2-pan test identified a preference for the chicken-based food in dogs with previous exposure to the food but only a weak and nonsignificant preference for the same food in dogs without previous exposure. Food preferences in the 2-pan test varied considerably. Total food consumption and the ability to detect a preference were reduced when dogs were fed prior to testing. CONCLUSIONS AND CLINICAL RELEVANCE The CPAP provides a reliable measure of food preference that requires few test subjects. The 2-pan test reveals similar preferences but with variability in data that requires larger numbers of subjects and is susceptible to effects from prior exposure and feeding of the test foods to the subjects.
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Affiliation(s)
- Joseph A Araujo
- Department of Pharmacology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 1A8
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Araujo JA, Chan ADF, Winka LL, Seymour PA, Milgram NW. Dose-specific effects of scopolamine on canine cognition: impairment of visuospatial memory, but not visuospatial discrimination. Psychopharmacology (Berl) 2004; 175:92-8. [PMID: 15029470 DOI: 10.1007/s00213-004-1777-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [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: 07/30/2003] [Accepted: 12/23/2003] [Indexed: 11/30/2022]
Abstract
RATIONALE The cholinergic system is linked extensively to memory, but its exact role remains controversial. In particular, scopolamine-induced impairment in rodents is not task specific, which may be due to difficulty in developing rodent protocols to assess deficits in recent memory, in which the remembered event is brief and distinct, and/or to non-specific behavioral impairment. OBJECTIVES The present study sought to determine whether scopolamine-induced deficits in recent memory, using a working memory task, could be dose-specifically dissociated from deficits in associative memory in dogs. METHODS A Latin-square design was used to determine the effect of scopolamine (5, 10 and 15 microg/kg; SC) on a variable delayed-non-matching-to-position (DNMP) task, which assesses visuospatial working memory. Subsequently, the minimal effective dose (15 microg/kg; SC) was administered prior to testing on a landmark discrimination task, which provides a measure of allocentric spatial ability, a black-white discrimination task, an oddity discrimination task and tests of exploratory behavior. We also investigated the effects of a 30 microg/kg dose (SC) on tests of oddity discrimination and behavioral activity. RESULTS A 15 microg/kg dose produced significant impairment on the DNMP task, but did not affect performance of any discrimination task and did not alter behavior on tests of open field or curiosity. A 30 microg/kg dose caused disruption on discrimination performance and on open field measures. CONCLUSIONS Working memory performance is most sensitive to scopolamine-induced impairment and can be dissociated from scopolamine-induced deficits in discrimination performance and non-cognitive behaviors. The present results indicate that scopolamine-induced impairments of working memory in the dog can serve as a model of age-related cholinergic dysfunction.
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Affiliation(s)
- J A Araujo
- Department of Pharmacology, University of Toronto, 1 King's College Circle, M5S 1A8, Toronto, ON, Canada
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Abstract
Assessment of canine palatability is important for both the pet food and pharmaceutical industries; however, the current palatability assessment protocols are limited in their utility. The most common technique, the two-pan test, does not control for the satiating effects of food and may not be useful for long-term palatability analysis because nutritional or caloric characteristics of the diets may interfere with the results. Furthermore, the large quantities of foods consumed may be detrimental to the health of animals that do not self-limit their food intake. The purpose of this study was to determine whether a cognitive protocol could be used to determine food palatability in dogs. Five beagle dogs were trained on a three-choice object-discrimination learning task. After establishing object preferences, the preferred object was associated with no reward, a second object was associated with the dog's normal laboratory diet (Purina Agribrands Canine Lab Chow No. 5006; Agribrands Purina Canada, Inc., Woodstock, ON, Canada), and the third object was associated with a commercial (Hill's P/D; Hill's Pet Nutrition Inc., Topeka, KS) diet. In the discrimination-training phase, dogs were trained until they learned to avoid the no-reward object. They were subsequently given an additional 20 test sessions, which were used to determine food preference. In the reversal phase, which involved reversal learning, the object-food associations were modified, such that the object that was previously associated with Hill's P/D diet was now associated with the normal laboratory diet and vice versa. Once the dogs learned to avoid the no-reward object, they were tested for an additional 20 sessions. All subjects learned to avoid the no-reward object during the initial learning, and the number of choices to the object associated with the Hill's P/D diet was greater than the number of choices to the objects associated with the dry laboratory diet (P < 0.05) and no reward (P < 0.05), indicating a strong preference for the Hill's P/D diet. The object preferences were reversed in only three of five dogs when the food-choice associations were reversed, although the two phases did not differ significantly from one another. The protocol in the present study provides a robust measure of food palatability and circumvents many of the limitations associated with other palatability assessment techniques. The present protocol should be useful as a replacement or adjunct to other tests of palatability, but requires further validation by comparing the assessment of more similar and novel foods directly with other palatability tests.
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Affiliation(s)
- J A Araujo
- Department of Pharmacology, University of Toronto, Toronto, Ontario, Canada
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Araujo JA, Studzinski CM, Milgram NW. P2-022 The effects of age and scopolamine on skilled motor function in dogs: further evidence of age-dependent cholinergic dysfunction. Neurobiol Aging 2004. [DOI: 10.1016/s0197-4580(04)80770-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
The transportation produced in the apical and middle areas of 30 mesiobuccal root canals of human mandibular molars was evaluated after circumferential instrumentation using stainless steel K-files (group A), nickel-titanium K-files (group B), and clockwise/counterclockwise file rotation using Flexogates (group C). The canals were instrumented with files #15 to #35 in size. Apical transportation was assessed radiographically while that occurring in the middle area was studied microscopically in cross-sections. Although apical transportation was greatest in the canals of group A, this difference was not statistically significant (P > 0.05). With respect to the middle area of the root canal, considerable transportation was observed in 7 of the 30 instrumented roots. Of these, five belonged to group A and two to group B, a difference which was not statistically significant (P > 0.05). The best results for transportation in the middle area of the canal were obtained in group C, in which no transportation occurred. This difference was significant when compared with the transportation observed in group A (P = 0.02) but not with that in group B (P > 0.05).
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Affiliation(s)
- F Goldberg
- Department of Endodontics, School of Dentistry, University del Salvador-Asociación Odontológica Argentina, Buenos Aires
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Araujo JA, Romano EL, Brito BE, Parthé V, Romano M, Bracho M, Montaño RF, Cardier J. Iron overload augments the development of atherosclerotic lesions in rabbits. Arterioscler Thromb Vasc Biol 1995; 15:1172-80. [PMID: 7542998 DOI: 10.1161/01.atv.15.8.1172] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Iron, a major oxidant in vivo, could be involved in atherosclerosis through the induction of the formation of oxidized LDL, a major atherogenic factor. This study was designed to test this hypothesis experimentally. Four groups of New Zealand White rabbits were included: iron-overloaded/hypercholesterolemic (group A, n = 8), iron-overloaded (group B, n = 6), hypercholesterolemic (group C, n = 6), and untreated (group D, n = 6). Iron overload was achieved by the intramuscular administration of 1.5 g of iron dextran divided in 30 doses. Hypercholesterolemia was produced by feeding rabbit chow enriched with 0.5% (wt/wt) cholesterol. Serum iron, ferritin, cholesterol, triglycerides, and lipoperoxides in serum were measured throughout the study. Lipoperoxides were measured at the end of the study in liver, aorta, and spleen homogenates. Aortas of groups A and C had multiple lesions; however, group A had greater lesional involvement than group C (P < .05). Lesions were not observed in rabbits fed normal chow (group D). As expected, serum iron and ferritin were above normal levels in groups A and B. Serum cholesterol increased in groups A and C. Lipoperoxides in liver and spleen homogenates of iron-overloaded rabbits were increased. Interestingly, iron deposits were seen by ultrastructural studies in the arterial walls of rabbits in groups A and B. Our study suggests that iron overload augments the formation of atherosclerotic lesions in hypercholesterolemic rabbits.
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Affiliation(s)
- J A Araujo
- Instituto Venezolano de Investigaciones Cientificas, Caracas, Venezuela
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Gutiérrez MC, Araujo JA. Congenital facial tumors. Pediatr Pathol Lab Med 1995; 15:643-5. [PMID: 8597851 DOI: 10.3109/15513819509027000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Araujo JA, Torres JM, de Souza Neto JD, Barros RB, da Rocha FA, de Almeida AP. [Difficulties of angiography in the diagnosis of acute aortic dissection. A case report]. Arq Bras Cardiol 1987; 49:51-5. [PMID: 3450258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Grases PJ, Vittori L, Santiago S, Guirola E, Araujo JA. [Submucosal lipoma of the sigmoid with colorectal invagination]. G E N 1986; 40:187-92. [PMID: 3135235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Jucá ER, Carvalho Júnior W, de Sousa JR, Araujo JA, Maia F, Karbage JM, Silva F. [Anomalous origin of the right pulmonary artery from the ascending aorta]. Arq Bras Cardiol 1979; 33:347-50. [PMID: 550769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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Garcia DP, Araujo JA, Maruz R, Arié S, de Oliveira SA. [Arterial spasm as a cause of acute coronary failure. Consideration on a case]. Rev Hosp Clin Fac Med Sao Paulo 1976; 31:420-4. [PMID: 1086500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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