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Recurrent Airway Obstruction (recurrent + airway_obstruction)
Selected AbstractsIncreased Parasite Resistance and Recurrent Airway Obstruction in Horses of a High-Prevalence FamilyJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2010S. Neuhaus Background: Equine recurrent airway obstruction (RAO) shares many characteristics with human asthma. In humans, an inverse relationship between susceptibility to asthma and resistance to parasites is suspected. Hypothesis/Objectives: Members of a high-incidence RAO half-sibling family (F) shed fewer strongylid eggs compared with RAO-unaffected pasture mates (PM) and that RAO-affected horses shed fewer eggs than RAO-unaffected half-siblings. Animals: Seventy-three F and 73 unrelated, age matched PM. Methods: Cases and controls kept under the same management and deworming regime were examined. Each individual was classified as RAO affected or RAO unaffected and fecal samples were collected before and 1,3 weeks and 3 months after deworming. Samples were analyzed by combined sedimentation-flotation and modified McMaster methods and classified into 3 categories of 0 eggs per gram of feces (EpG), 1,100 EpG, and >100 EpG, respectively. Results: PM compared with RAO-affected F had a 16.7 (95% confidence interval [CI]: 2.0,136.3) times higher risk for shedding > 100 EpG compared with 0 EpG and a 5.3 (95% CI: 1.0,27.4) times higher risk for shedding >100 EpG compared with 0 EpG. There was no significant effect when RAO-unaffected F were compared with their PM. RAO-unaffected compared with RAO-affected offspring had a 5.8 (95% CI: 0.0,1.0) times higher risk for shedding 1,100 EpG. Age, sex, breed, and sharing pastures with other species had no significant confounding effects. Conclusion and Clinical Importance: RAO is associated with resistance against strongylid parasites in a high-prevalence family. [source] Airway Mucus in Recurrent Airway Obstruction, Short-Term Response to Environmental ChallengeJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2004V. Gerber Mucus accumulation and neutrophilic inflammation in the airways are hallmarks of heaves. Endoscopically visible mucus accumulations, however, have not been studied during exposure to dusty hay and allergens (ie, environmental challenge). We hypothesized that (1) heaves-affected horses have increased mucus accumulation compared with controls, (2) mucus accumulations increase in heaves-affected horses during environmental challenge, and (3) environmental challenge also induces neutrophilic inflammation and mucus accumulation in control horses. Mucus accumulation was graded endoscopically (mucus grades [MGs] 1,5), and airway inflammation was evaluated by bronchoalveolar lavage fluid (BALF) cytology before (0 hours) and during (6, 24, 48 hours) environmental challenge. Large amounts of mucus (MG 4,5) were specific for heaves-affected horses in this study. Variation among controls was considerable, however, and intermediate grades (MG 2,3) were nonspecific, showing complete overlap between the 2 groups. Median mucus accumulations (25th, 75th percentiles) increased in heaves-affected horses from MG 2.5 (1.5, 3.5) at baseline to MG 3.5 (2.0, 4.0), 4.0 (3.0, 4.0), and 4.0 (4.0, 4.0) at 6, 24, and 48 hours, respectively. MG values did not increase in controls,overall MG 1.0 (1.0, 2.0),even though controls also showed a moderate increase of BALF neutro-phils. Mucus accumulations before and especially after exposure to dust and allergens are increased in heaves-affected horses compared with controls. Healthy controls show considerable variability in mucus accumulation but, despite an influx of neutrophils into the airways, no increase of mucus accumulation after exposure to hay dust. [source] Environment and prednisone interactions in the treatment of recurrent airway obstruction (heaves)EQUINE VETERINARY JOURNAL, Issue 5 2000C. A. Jackson Summary Recurrent airway obstruction (RAO) or heaves is a manifestation of a hypersensitivity to dust, moulds, and spores in the environment of a susceptible horse. Although in the majority of RAO-affected horses, clinical remission can be achieved by keeping horses at pasture to reduce their allergen exposure, this often is not practicable. For this reason, we investigated if changing the environment of a single stall in a 4 stall stable was sufficient to improve lung function and reduce inflammation in RAO-affected horses. In addition, we determined if addition of oral prednisone provided additional benefit. Twelve RAO-susceptible horses were stabled, fed hay, and bedded on straw until they developed airway obstruction. At this point, bedding was changed to wood shavings and they were fed a pelleted diet for 2 weeks. Lung function was measured and bronchoalveolar lavage was performed before and 3, 7, and 14 days after environmental modification. In a crossover design, horses were treated for the 14 days with prednisone tablets (2.2 mg/kg bwt, q. 24 h). Horses then returned to pasture for 30 days. Airway obstruction was greatest before environmental modification. Significant improvement in lung function occurred within 3 days of the change in environment and continued to Day 7. Airway function was best after 30 days at pasture. The clinical response achieved by environmental modification was not significantly improved by addition of oral prednisone. The total number of cells, total neutrophils, and percent neutrophils was greatest before environmental modification. In the absence of prednisone, total and percent neutrophils did not decrease until Day 14 and total cell number until 30 days at pasture. In the presence of prednisone, total cells and total and percent neutrophils decreased by Day 3 and again at pasture. The fact that lung function can be improved within 3 days by environmental management alone emphasises the need for allergen reduction as the cornerstone of treatment of RAO. Although prednisone induced a more rapid reduction in airway inflammation, this was not associated with a more rapid improvement in airway function. [source] Effects of a MAPK p38 inhibitor on lung function and airway inflammation in equine recurrent airway obstructionEQUINE VETERINARY JOURNAL, Issue 6 2008J.-P. LAVOIE Summary Reasons for performing study: It has been suggested that many of the beneficial effects of corticosteroids are mediated through mitogen-activated protein kinase (MAPK) p38 inhibition. Objective: To investigate the efficacy of the MAPK p38 inhibitor compound MRL-EQ1 to either prevent (Phase 1) or treat (Phase 2) recurrent airway obstruction (RAO) in horses. Methods: MRL-EQ1 was administered i.v. at a dosage of 0.75-1.5 mg/kg bwt q. 12 h. In Phase 1, susceptible horses in clinical remission were divided into 2 groups (n = 5/group), based on historical values of respiratory mechanics. All horses were entered in the study in pairs (one control, one treated horse) and exposed to the same environmental challenge (stabling, mouldy hay and dusty conditions). The treatment group received MRL-EQ1 for 14 days while the control horses were untreated during the same period. In Phase 2, affected horses were ranked by severity of respiratory dysfunction and split randomly into either dexamethasone or MRL-EQ1 treatment groups (n = 5/group). Bronchoalveolar lavage fluid, respiratory mechanic measurements, MRL-EQ1 plasma concentration and tumour necrosis factor (TNF) whole blood activity were evaluated sequentially. Results: In Phase 1, MRL-EQ1 did not prevent the occurrence of clinical signs and pulmonary inflammation. However, treatment was associated with a reduction in severity and a delay in the onset of signs and a reduction in pulmonary neutrophilia. In Phase 2, plasma concentrations achieved resulted in ex vivo suppression of lipopolysaccharide-induced TNF production in equine blood. MRL-EQ1 did not improve airway inflammation or lung function and was associated in a dose dependent manner with behavioural (depression, excitability) and blood changes (neutrophilia, increased serum muscle enzyme concentrations). Conclusions: Inhibition of p38 in the horse was partially effective in reducing clinical signs and airway inflammation when administered prior to, but not during clinical exacerbation in RAO. Potential relevance: Inhibitors of p38 MAPK with a better toxicity profile may be effective in the prevention or treatment of RAO. [source] A region on equine chromosome 13 is linked to recurrent airway obstruction in horsesEQUINE VETERINARY JOURNAL, Issue 3 2007U. JOST Summary Reasons for study: Equine recurrent airway obstruction (RAO) is probably dependent on a complex interaction of genetic and environmental factors and shares many characteristic features with human asthma. Interleukin 4 receptor , chain (IL4RA) is a candidate gene because of its role in the development of human asthma, confirmation of this association is therefore required. Methods: The equine BAC clone containing the IL4RA gene was localised to ECA13q13 by the FISH method. Microsatellite markers in this region were investigated for possible association and linkage with RAO in 2 large Warmblood halfsib families. Based on a history of clinical signs (coughing, nasal discharge, abnormal breathing and poor performance), horses were classified in a horse owner assessed respiratory signs index (HOARSI 1,4: from healthy, mild, moderate to severe signs). Four microsatellite markers (AHT133, LEX041, VHL47, ASB037) were analysed in the offspring of Sire 1 (48 unaffected HOARSI 1 vs. 59 affected HOARSI 2,4) and Sire 2 (35 HOARSI 1 vs. 50 HOARSI 2,4), age ,7 years. Results: For both sires haplotypes could be established in the order AHT133-LEX047-VHL47-ASB37. The distances in this order were estimated to be 2.9, 0.9 and 2.3 centiMorgans, respectively. Haplotype association with mild to severe clinical signs of chronic lower airway disease (HOARSI 2,4) was significant in the offspring of Sire 1 (P = 0.026) but not significant for the offspring of Sire 2 (P = 0.32). Linkage analysis showed the ECA13q13 region containing IL4RA to be linked to equine chronic lower airway disease in one family (P<0.01), but not in the second family. Conclusions: This supports a genetic background for equine RAO and indicates that IL4RA is a candidate gene with possible locus heterogeneity for this disease. Potential relevance: Identification of major genes for RAO may provide a basis for breeding and individual prevention for this important disease. [source] Theophylline does not potentiate the effects of a low dose of dexamethasone in horses with recurrent airway obstructionEQUINE VETERINARY JOURNAL, Issue 6 2006C. CESARINI Summary Reasons for performing study: Theophylline has been shown to have corticosteroid-sparing effects for the treatment of human asthma. A similar effect, if present in horses, would allow diminishing the dose of corticosteroids administered to equine patients with inflammatory airway diseases. Objectives: To evaluate whether theophylline potentiates the effects of a low dose of dexamethasone when treating horses with recurrent airway obstruction (RAO). Hypothesis: Theophylline has steroid-sparing effects in horses with RAO. Methods: Ten mature mixed breed horses in clinical exacerbation of RAO were studied. Using an incomplete crossover design and 3 experimental periods of 7 days duration, horses were distributed randomly in 5 treatment groups; and administered dexamethasone s.i.d., at either 0.05 mg/kg bwt i.v. or per os, or 0.02 mg/kg bwt alone or combined with theophylline at 5 mg/kg bwt per os b.i.d. A fifth group was treated with theophylline alone at the above dosage. Lung function was evaluated prior to drug administration and then 3 and 7 days later. Results: Oral administration of dexamethasone alone or combined with theophylline failed to improve lung function significantly in RAO affected horses. Theophylline alone also failed to improve lung function in all treated horses. Conversely, dexamethasone administration at 0.05 mg/kg bwt i.v. resulted in a significant improvement in lung function starting on Day 3. Conclusions and potential relevance: Oral theophylline for 7 days did not improve the effects of a low dose of dexamethasone for the treatment of horses with RAO. [source] Antioxidant and inflammatory responses of healthy horses and horses affected by recurrent airway obstruction to inhaled ozoneEQUINE VETERINARY JOURNAL, Issue 3 2005C. M. DEATON Summary Reasons for performing study: Inhaled ozone can induce oxidative injury and airway inflammation. Horses affected by recurrent airway obstruction (RAO) have a decreased pulmonary antioxidant capacity, which may render them more susceptible to oxidative challenge. It is currently unknown whether RAO-affected horses are more susceptible to oxidative stress than those unaffected by RAO. Objectives: To determine whether ozone exposure induces greater oxidative stress and airway inflammation in RAO-affected horses in remission than in healthy horses. Methods: Seven healthy control horses and 7 RAO-affected horses were exposed to 0.8 ppm ozone for 2 h at rest. Results: At baseline, bronchoalveolar lavage fluid (BALF) ascorbic acid concentrations were lower in RAO-affected horses than healthy controls. Ozone appeared to preferentially oxidise glutathione rather than ascorbic acid 6 h after exposure. Individual healthy and RAO-affected horses demonstrated oxidation of BALF glutathione after ozone exposure. Overall, RAO-affected horses did not demonstrate increased oxidative stress following ozone exposure, compared with healthy horses. Ozone did not induce significant airway inflammation in either group. Conclusions: RAO-affected horses in remission are not more sensitive to ozone despite a decreased pulmonary antioxidant capacity. Sensitivity to ozone appears to be independent of initial pulmonary antioxidant status. Potential relevance: Horses with high susceptibility to oxidative stress may benefit from antioxidant supplementation. [source] Environment and prednisone interactions in the treatment of recurrent airway obstruction (heaves)EQUINE VETERINARY JOURNAL, Issue 5 2000C. A. Jackson Summary Recurrent airway obstruction (RAO) or heaves is a manifestation of a hypersensitivity to dust, moulds, and spores in the environment of a susceptible horse. Although in the majority of RAO-affected horses, clinical remission can be achieved by keeping horses at pasture to reduce their allergen exposure, this often is not practicable. For this reason, we investigated if changing the environment of a single stall in a 4 stall stable was sufficient to improve lung function and reduce inflammation in RAO-affected horses. In addition, we determined if addition of oral prednisone provided additional benefit. Twelve RAO-susceptible horses were stabled, fed hay, and bedded on straw until they developed airway obstruction. At this point, bedding was changed to wood shavings and they were fed a pelleted diet for 2 weeks. Lung function was measured and bronchoalveolar lavage was performed before and 3, 7, and 14 days after environmental modification. In a crossover design, horses were treated for the 14 days with prednisone tablets (2.2 mg/kg bwt, q. 24 h). Horses then returned to pasture for 30 days. Airway obstruction was greatest before environmental modification. Significant improvement in lung function occurred within 3 days of the change in environment and continued to Day 7. Airway function was best after 30 days at pasture. The clinical response achieved by environmental modification was not significantly improved by addition of oral prednisone. The total number of cells, total neutrophils, and percent neutrophils was greatest before environmental modification. In the absence of prednisone, total and percent neutrophils did not decrease until Day 14 and total cell number until 30 days at pasture. In the presence of prednisone, total cells and total and percent neutrophils decreased by Day 3 and again at pasture. The fact that lung function can be improved within 3 days by environmental management alone emphasises the need for allergen reduction as the cornerstone of treatment of RAO. Although prednisone induced a more rapid reduction in airway inflammation, this was not associated with a more rapid improvement in airway function. [source] Increased Parasite Resistance and Recurrent Airway Obstruction in Horses of a High-Prevalence FamilyJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2010S. Neuhaus Background: Equine recurrent airway obstruction (RAO) shares many characteristics with human asthma. In humans, an inverse relationship between susceptibility to asthma and resistance to parasites is suspected. Hypothesis/Objectives: Members of a high-incidence RAO half-sibling family (F) shed fewer strongylid eggs compared with RAO-unaffected pasture mates (PM) and that RAO-affected horses shed fewer eggs than RAO-unaffected half-siblings. Animals: Seventy-three F and 73 unrelated, age matched PM. Methods: Cases and controls kept under the same management and deworming regime were examined. Each individual was classified as RAO affected or RAO unaffected and fecal samples were collected before and 1,3 weeks and 3 months after deworming. Samples were analyzed by combined sedimentation-flotation and modified McMaster methods and classified into 3 categories of 0 eggs per gram of feces (EpG), 1,100 EpG, and >100 EpG, respectively. Results: PM compared with RAO-affected F had a 16.7 (95% confidence interval [CI]: 2.0,136.3) times higher risk for shedding > 100 EpG compared with 0 EpG and a 5.3 (95% CI: 1.0,27.4) times higher risk for shedding >100 EpG compared with 0 EpG. There was no significant effect when RAO-unaffected F were compared with their PM. RAO-unaffected compared with RAO-affected offspring had a 5.8 (95% CI: 0.0,1.0) times higher risk for shedding 1,100 EpG. Age, sex, breed, and sharing pastures with other species had no significant confounding effects. Conclusion and Clinical Importance: RAO is associated with resistance against strongylid parasites in a high-prevalence family. [source] Plastic bronchitis as an unusual cause of mucus plugging in cystic fibrosisPEDIATRIC PULMONOLOGY, Issue 9 2009Dimas Mateos-Corral MD Abstract Cystic fibrosis patients are known to produce abundant, purulent sputum consisting mainly of DNA and cellular debris. We present a case of a CF patient with recurrent airway obstruction caused by a rare condition known as plastic bronchitis (PB). PB is characterized by the formation of casts of the airways that cause obstruction. Multiple etiologies have been proposed, but to our knowledge, no CF patient has been reported in any PB classification. Histological analysis and in-vitro testing of the cast were important factors in choosing the adequate therapy in this patient. Pediatr Pulmonol. 2009; 44:939,940. © 2009 Wiley-Liss, Inc. [source] Characterization of the equine ITGAX gene and its association with recurrent airway obstruction in European Warmblood horsesANIMAL GENETICS, Issue 5 2010M. Shakhsi-Niaei No abstract is available for this article. [source] | ||||||||||