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1.
Objective: To validate the use of the LigaSure? Vessel Sealing System (LVSS) to perform thoracoscopic lung tissue biopsies in heaves‐affected horses. Study design: Prospective clinical study. Animals: Heaves‐affected horses (n=12). Methods: Lung biopsies (n=34) were collected with the LVSS (2–4 biopsies/horse) in horses with and without clinical signs of heaves. Thoracoscope (13th intercostal space [ICS]) and 2 instruments (between the 12–15th ICS) portals were used. Selected clinical and arterial blood gas variables were monitored. Postoperative pneumothorax was evaluated. Depth of thermal injury to the surrounding tissue and representativeness of the biopsies were determined. Results: Mean surgical time was 22.9±8.0 minutes. The complication rate was 5.6%, and primarily related to a focal inadequate sealing of the biopsy margin. Five horses in exacerbation required intraoperative intranasal O2. Mean PaO2 was significantly lower in heaves‐affected horses with clinical signs compared with those without clinical signs. Postoperative pneumothorax was detected radiographically after 20 of the 34 procedures. One horse with clinical signs of heaves developed a fatal tension pneumothorax 5 days postoperatively despite close radiographic monitoring. Conclusion: Thoracoscopic lung biopsy using LVSS is a rapid and effective technique to harvest peripheral lung tissues from heaves‐affected horses. Although the complication rate was tolerable, tension pneumothorax was a potential life‐threatening complication because of incomplete lung sealing. Clinical Relevance: LVSS can be used with relative safety to perform thoracoscopic lung biopsy, but close postoperative monitoring is necessary to avoid tension pneumothorax.  相似文献   

2.
OBJECTIVE: To evaluate the safety and efficacy of thoracoscopically guided pulmonary wedge resection in horses. ANIMALS: 10 horses (5 control horses and 5 horses affected with recurrent airway obstruction [ie, heaves]). PROCEDURE: Each horse underwent a thoracoscopically guided pulmonary wedge resection. Before, during, and after surgery, heart rate, respiratory rate, arterial blood gases, and systemic and pulmonary arterial pressures were measured. Physical examination, CBC, and thoracic radiography and ultrasonography were performed 24 hours before and 2 and 48 hours after surgery. Pulmonary specimens were assessed by histologic examination. A second thoracoscopic procedure 14 days later was used to evaluate the resection site. RESULTS: The technique provided excellent specimens for histologic evaluation of the lung. Heart and respiratory rates decreased significantly after horses were administered sedatives. A significant transient decrease in Pao2 was detected immediately after pulmonary wedge resection, but we did not detect significant effects on arterial pH, Paco2, or mean arterial and pulmonary arterial pressures. All horses except 1 were clinically normal after thoracoscopic surgery; that horse developed hemothorax attributable to iatrogenic injury to the diaphragm. The second thoracoscopy revealed minimal inflammation, and there were no adhesions. CONCLUSIONS AND CLINICAL RELEVANCE: Thoracoscopically guided pulmonary wedge resection provides a minimally invasive method for use in obtaining specimens of lung tissues from healthy horses and those with lung disease. This technique may be useful for the diagnosis of diseases of the lungs and thoracic cavity.  相似文献   

3.
Airway remodeling may play an important role in heaves pathophysiology. Transforming growth factor-beta 1 (TGF-beta1) is a potent profibrotic cytokine, which might contribute to airway wall thickening and fibrosis of bronchiolar and alveolar submucosa. An ELISA designed for the measurement of human TGF-beta1 was used to measured total TGF-beta1 released in bronchoalveolar lavage fluid (BALF) of normal horses and of those affected with heaves in remission. The specificity of the assay for TGF-beta1 of the horse was confirmed using recombinant equine TGF-beta1. The influence of hay exposure on TGF-beta1 release in the airways was also examined by stabling horses in a dusty environment. TGF-beta1 was found in the BALF of all horses. However, no significant difference between basal concentration of TGF-beta1 in BALF of control horses versus that of horses affected with heaves was found. Furthermore, no differences were identified in these populations 1 and 9 days after allergen challenge. In conclusion, these data indicate that TGF-beta1 is released in BALF fluid of horses in biologically active concentrations. Other studies are necessary for a better definition of the role of this cytokine within the lung, as our study does not establish a causal relationship between TGF-beta1 and the pathophysiology of heaves in the horse.  相似文献   

4.
Background: Corticosteroids currently are the most effective pharmacological treatment available to control heaves in horses. Systemically administered corticosteroids have been shown to alter immune response in horses, humans, and other species. Aerosolized administration theoretically minimizes systemic adverse effects, but the effect of inhaled corticosteroids on immune function has not been evaluated in horses. Objectives: To evaluate the effects of prolonged administration of inhaled fluticasone on the immune system of heaves‐affected horses. Animals: Heaves‐affected horses were treated with inhaled fluticasone (n = 5) for 11 months or received environmental modifications only (n = 5). Methods: Prospective analysis. Clinical parameters and CBC, lymphocyte subpopulations and function, and circulating neutrophil gene expression were sequentially measured. Primary and anamnestic immune responses also were evaluated by measuring antigen‐specific antibodies in response to vaccination with bovine viral antigen and tetanus toxoid, respectively. Results: No clinical adverse effects were observed and no differences in immune function were detected between treated and untreated horses. Conclusions and Clinical Importance: The treatment of heaves‐affected horses with inhaled fluticasone at therapeutic dosages for 11 months has no significant detectable effect on innate and adaptive (both humoral and cell‐mediated) immune parameters studied. These results suggest that prolonged administration of fluticasone would not compromise the systemic immune response to pathogens nor vaccination in adult horses.  相似文献   

5.
Reasons for performing study: Efficacy of medications for recurrent airway obstruction is typically tested using clinical, cytological and lung function examinations of severely affected animals. These trials are technically challenging and may not adequately reflect the spectrum of disease and owner complaints encountered in clinical practice. Objective: To determine if owners of horses with chronic airway disease are better able to detect drug efficacy than a veterinarian who clinically examines horses infrequently. Method: In a double‐blinded randomised controlled trial, owners and a veterinarian compared the efficacy of dexamethasone (0.1 mg/kg bwt per os, q. 24 h, for 3 weeks; n = 9) to placebo (n = 8) in horses with chronic airway disease. Before and after treatment, owners scored performance, breathing effort, coughing and nasal discharge using a visual analogue scale (VAS). The clinician recorded vital parameters, respiratory distress, auscultation findings, cough and nasal discharge, airway mucus score, bronchoalveolar lavage fluid (BALF) cytology and arterial blood gases. Results: The VAS score improved significantly in dexamethasone‐ but not placebo‐treated horses. In contrast, the clinician failed to differentiate between dexamethasone‐ and placebo‐treated animals based on clinical observations, BALF cytology or endoscopic mucus score. Respiratory rate (RR) and arterial oxygen pressure (PaO2) improved with dexamethasone but not placebo. Conclusions and clinical relevance: In the design of clinical trials of airway disease treatments, more emphasis should be placed on owner‐assessed VAS than on clinical, cytological and endoscopic observations made during brief examinations by a veterinarian. Quantifiable indicators reflecting lung function such as RR and PaO2 provide a good assessment of drug efficacy.  相似文献   

6.
A three-year-old, 30-kg, spayed female German wirehaired pointer was presented for coughing, pyrexia and lethargy. Thoracic radiographs showed mild right-sided pleural effusion, moderate pneumothorax and a pulmonary lesion in the right middle or caudal lung lobe. A diagnosis of pyothorax was established by fine needle aspiration of the pleural effusion. Thoracoscopic exploration was performed using one-lung ventilation. A vegetal foreign body (grass awn) and an abscess were observed in the distal part of the right middle lung lobe. The foreign body was removed and a right middle lung lobectomy was performed, both thoracoscopically. No complications were noted. The dog was discharged 48 hours after surgery, and no recurrence of the clinical signs was observed during the follow-up time period (three years and three months). Thoracoscopy is a minimally invasive alternative to thoracotomy to explore and successfully treat some non-chronic pyothoraces in dogs, including lesions affecting the right middle lung lobe.  相似文献   

7.
To investigate whether inhaled endotoxin contributes to airway inflammation and dysfunction in stabled horses, control (n = 6) and asymptomatic heaves (previously termed chronic obstructive pulmonary disease)-susceptible (n = 7) horses were given inhalation challenges with 20, 200 and 2,000 microg of soluble Salmonella typhimurium Ra60 lipopolysaccharide (LPS). LPS inhalation induced a dose-dependent neutrophilic airway inflammatory response in both groups. Inhalation with 2,000 microg of LPS also induced detectable lung dysfunction in the heaves group. LPS inhalation did not alter clinical score, tracheal secretion volume or airway reactivity in either group. The no-response thresholds were lower for the heaves group (<20 microg for airway inflammation; 200 to 2,000 microg for lung dysfunction) than for the control group (20 to 200 microg for airway inflammation; >2,000 microg for lung dysfunction). To enable comparison of these threshold levels with airborne endotoxin concentrations in stables, horses also received a 5 h duration hay/straw challenge, during which the total and respirable airborne endotoxin concentrations were determined. Comparison of the effects of acute LPS inhalation and hay/straw challenges suggest that inhaled endotoxin is not the sole cause of heaves. However, it is likely that it contributes to airway inflammation, both in heaves horses in concert with other inhalants, and in normal horses when they are exposed to high levels in poor stable environments.  相似文献   

8.
OBJECTIVE: To evaluate whether bronchoalveolar lavage (BAL) alters respiratory mechanics of horses with recurrent airway obstruction (ie, heaves) over a 48-hour period. ANIMALS: 6 horses affected with heaves. PROCEDURES: Horses were subjected to a complete BAL procedure, which included sedation with xylazine and butorphanol, intratracheal administration of lidocaine, and instillation and aspiration of two 250-mL boluses of saline (0.9% NaCl) solution through an endoscope (study 1). To evaluate the effects of saline solution, horses were subjected to the same procedure without saline solution instillation and aspiration (study 2). Lastly, the endoscope was similarly introduced into the lower airways, without sedation or saline instillation and aspiration (study 3). Respiratory mechanics were performed at baseline (time 0) and at 3, 6, 12, 24, and 48 hours after each procedure. RESULTS: In study 1, BAL induced a significant decrease in pulmonary resistance lasting up to 6 hours. This may have resulted from clearance of mucus in large airways. We also observed a significant increase in lung elastance and transpulmonary pressure at 12 hours after BAL in all 3 studies, which may be attributed to a circadian effect. CONCLUSIONS AND CLINICAL RELEVANCE: Our results indicate that the temporal effects of BAL procedures on lung mechanics should be taken into account when designing research protocols involving horses with heaves. Future studies should address the immediate effects of BAL on lung function.  相似文献   

9.
Phosphodiesterase-4 (PDE 4) enzyme inhibitors have been shown to have anti-inflammatory properties in various animal disease processes and therefore could be effective drugs for the treatment of equine airway diseases. The purpose of this study was to evaluate the efficacy and adverse effects of the PDE 4 inhibitor L-826,141 in horses with heaves. In a blinded parallel design, horses with heaves exposed daily to moldy hay were given a placebo for 14 days and then administered either L-826,141 (n = 6; loading dose of 1 mg/kg IV followed by 0.5 mg/kg IV q48h) or dexamethasone (n = 6; 0.04 mg/kg IV q24h) from days 15 to 29 (study 1). Pulmonary function and bronchoalveolar (BAL) cytology were evaluated weekly from baseline (day 0) to 29 days. In study 2, horses were treated with L-826,141 (1.0 mg/kg IV q24h) for 8 days. Although ex vivo lipopolysaccharide-induced tumor necrosis factor (TNF)-alpha and LTB4 production by fresh blood were inhibited up to 90% after repeated administrations of L-826,141, this treatment failed to improve lung function. In contrast, dexamethasone (positive control) treatment resulted in significant improvement in lung mechanics and airway function in all horses. Neither drug had a significant effect on BAL total cell counts and differential cytology. Administration of the PDE 4 inhibitor L-826,141 for up to 14 days to horses with heaves was not associated with an improvement in airway function or inflammation. These findings suggest that the PDE 4 enzyme is not a key mediator of lung inflammation in heaves.  相似文献   

10.
OBJECTIVE: To evaluate whether the leukotriene (LT) D4 receptor antagonist L-708,738 is therapeutically beneficial in treating horses with recurrent airway obstruction (heaves). ANIMALS: 12 adult horses with heaves and healthy lung lobes from 20 slaughtered horses. PROCEDURE: Lung lobes were used for smooth muscle tension and radioligand binding studies. Horses with heaves were given a placebo for 14 days and administered L-708,738 (n = 6; 2.5 mg/kg PO, q 12 h) or dexamethasone (6; 0.04 mg/kg, IV, q 24 h) from days 14 to 28. Pulmonary function was measured weekly for 36 days, and bronchoalveolar cells were collected on days 0,14, and 29 for cytologic examination. RESULTS: Nanomolar concentrations of L-708,738 were effective at antagonizing LTD4-induced bronchoconstriction and LTD4-receptor binding in lung lobes. Mean peak and trough L708,738 plasma concentrations during the treatment period were 1.54 and 0.28 microM, respectively. On days 21 and 29, lung mechanics were significantly improved in the dexamethasone-treated horses but not in the L-708,738-treated horses. Neither dexamethasone nor L-708,738 had a significant effect on cytologic findings. CONCLUSIONS AND CLINICAL RELEVANCE: L-708,738 was bioavailable after oral administration and sustained concentrations in plasma during the dosing period that exceeded in vitro efficacy values. However, airway function did not improve, suggesting that either drug concentrations in the lungs were subtherapeutic or that cysteinyl LT may not be important mediators of airway inflammation in heaves. Results provide the first evidence of cysteinyl LT1 receptors in airways of horses.  相似文献   

11.
We report the effects of mouldy hay/straw exposure, inhaled hay dust suspension (HDS) and inhaled lipopolysaccharide (LPS) on bronchoalveolar lavage fluid (BALF) gelatinolytic matrix metalloproteinase (MMP) levels and degree of activation in healthy (n = 6) and heaves- (previously termed chronic obstructive pulmonary disease) affected (n = 6 or 7) horses. Gelatinolytic MMPs in BALF were quantified by zymography, and gelatinases were shown by Western immunoblotting to be MMP-2 and MMP-9. Hay/straw and HDS challenges increased BALF total gelatinolytic activity only in heaves horses, with the majority of gelatinolytic activity comprising pro- and active MMP-9. The 5 h duration hay/straw challenge increased BALF gelatinolytic MMP activity in heaves horses at 5 and 24 h after the start of this challenge, with activity returning to baseline by Day 4. In contrast to hay/straw and HDS challenges, LPS inhalation increased BALF gelatinolytic MMP activity in both groups. For all challenges, absolute BALF neutrophil counts were highly significantly correlated (P<0.0001) with levels of proMMP-9 and active MMP-9, but not with levels of MMP-2 (P>0.05). As gelatinolytic MMPs are pro-inflammatory agents, they may contribute to lung dysfunction and tissue destruction in heaves horses exposed to airborne organic stable dusts.  相似文献   

12.
OBJECTIVE: To determine whether pulmonary distribution of aerosolized technetium Tc 99m pentetate is improved after inhalation of a single dose of albuterol sulfate in horses susceptible to recurrent airway obstruction (heaves). ANIMALS: 6 horses with heaves and 4 horses with normal respiratory tract function. PROCEDURE: Images were obtained during ventilation of horses at baseline (maximal change in pleural pressure during tidal breathing [deltaPpImax] >15 cm H2O) and after aerosolized albuterol sulfate (360 microg) administration, with a 24-hour washout period between experiments. The deltaPpImax was determined prior to the baseline scan, prior to albuterol sulfate administration, and 5 minutes after albuterol sulfate administration. Images were assessed by visual inspection (semi-quantitative scoring system) and histogram analysis. RESULTS: Images obtained from horses with heaves had nonuniform pulmonary distribution of radionuclide characterized by poor penetration in peripheral lung fields and excess deposition in large airways. Histogram analysis of images of the caudal portions of the lungs revealed nonuniform radionuclide deposition in horses with heaves and uniform radionuclide deposition in control horses. CONCLUSION: Administration of a single dose of aerosolized albuterol sulfate improved pulmonary distribution of aerosolized radiolabeled pentetate suspension in horses with heaves but did not alter pulmonary distribution in clinically normal horses. CLINICAL RELEVANCE: Precedent bronchodilator administration may improve pulmonary distribution of aerosolized, surface-active anti-inflammatory preparations.  相似文献   

13.
The aim of the study reported here was to compare complications of lung biopsy in horses and the quality of the lung specimens after biopsy using the manual Tru-Cut biopsy needle (TC) and an automated biopsy needle (ABN). For experiment 1, lung biopsy was performed in 50 horses with one instrument on one side of the thorax, and then with the other instrument on the other side. Postmortem examination was performed in 20 of the 50 horses. Coughing was detected in 10 of 50 horses and epistaxis was observed in 6 of the 50 horses. Endoscopy revealed bleeding into the airways in 16 of 49 horses and in 5 of 49 horses after biopsy with the TC or the ABN, respectively. Use of the ABN induced a significantly smaller amount of bleeding. Pneumothorax was detected by radiography in 1 of 50 horses. Hematoma diameter determined in 7 of 20 horses at postmortem examination, was significantly larger after biopsy with the TC than with the ABN. The quality of the lung specimen was good. In experiment 2, complications after repeated and multiple lung biopsies in 6 horses were evaluated. Moderate epistaxis was observed on 13 of 104 occasions. Bleeding into the airways was detected at endoscopy on 41 of 104 occasions, and pneumothorax was detected during 4 of 104 occasions. Complications such as hematoma at the biopsy site and bleeding into the airways were greater after biopsy with the TC than after use of the ABN. Lung biopsy specimens obtained with the ABN were fairly safe for the animal.  相似文献   

14.
Nuclear factor-κB (NF-κB) activity, which is a key regulator of inflammatory gene expression, is increased in bronchial epithelial cells from horses suffering from heaves (a hypersensitivity-associated inflammatory condition of the lung). To determine whether this increased activity extends to distal airways and to other pulmonary cells, cells recovered by broncho-alveolar lavage (BAL) in healthy and heaves-affected horses were assessed for NF-κB activity. NF-κB activity was much higher in BAL cells from heaves-affected horses, especially during crisis (disease exacerbation), than in cells from healthy horses. Moreover, the level of NF-κB activity found in BAL cells was positively correlated to total lung resistance and to the proportion of neutrophils present in BAL fluid. Finally, prototypical p65–p50 NF-κB heterodimers were absent from BAL cells, which mostly contained p65 homodimers. These results (1) show that increased NF-κB activity is a general feature of heaves lung; (2) demonstrate the importance of p65 homodimers in neutrophilic inflammation; and (3) suggest that the use of specific NF-κB inhibitors could improve lung function in heaves-affected horses.  相似文献   

15.
Objective To compare, ventilation using intermittent positive pressure ventilation (IPPV) with constant positive end‐expiratory pressure (PEEP) and alveolar recruitment manoeuvres (RM) to classical IPPV without PEEP on gas exchange during anaesthesia and early recovery. Study design Prospective randomized study. Animals Twenty‐four warm‐blood horses, weight mean 548 ± SD 49 kg undergoing surgery for colic. Methods Premedication, induction and maintenance (isoflurane in oxygen) were identical in all horses. Group C (n = 12) was ventilated using conventional IPPV, inspiratory pressure (PIP) 35–45 cmH2O; group RM (n = 12) using similar IPPV with constant PEEP (10 cmH2O) and intermittent RMs (three consecutive breaths PIP 60, 80 then 60 cmH2O, held for 10–12 seconds). RMs were applied as required to maintain arterial oxygen tension (PaO2) at >400 mmHg (53.3 kPa). Physiological parameters were recorded intraoperatively. Arterial blood gases were measured intra‐ and postoperatively. Recovery times and quality of recovery were measured or scored. Results Statistically significant findings were that horses in group RM had an overall higher PaO2 (432 ± 101 mmHg) than those in group C (187 ± 112 mmHg) at all time points including during the early recovery period. Recovery time to standing position was significantly shorter in group RM (49.6 ± 20.7 minutes) than group C (70.7 ± 24.9). Other measured parameters did not differ significantly. The median (range) of number of RMs required to maintain PaO2 above 400 mmHg per anaesthetic was 3 (1–8). Conclusion Ventilation using IPPV with constant PEEP and RM improved arterial oxygenation lasting into the early recovery period in conjunction with faster recovery of similar quality. However this ventilation mode was not able to open up the lung completely and to keep it open without repeated recruitment. Clinical relevance This mode of ventilation may provide a clinically practicable method of improving oxygenation in anaesthetized horses.  相似文献   

16.
Objective To compare the arterial pH and blood gas values, heart rate and mean arterial blood pressure, in hypoxaemic anaesthetized horses, before and after treatment, with a salbutamol (albuterol) aerosol. Animal population Eighty‐one client‐owned horses weighing between 114 and 925 kg. Fifty‐seven underwent emergency abdominal surgery and 24 were anaesthetized for elective procedures. Materials and methods Pre‐anaesthetic medication included xylazine, detomidine, butorphanol and morphine, alone or in various combinations. Induction of anaesthesia was achieved with guaifenesin and ketamine, diazepam and ketamine, or guaifenesin and thiopental. The trachea of all animals was intubated and anaesthesia maintained with either halothane (33 horses) or isoflurane (48 horses) in oxygen. Heart rate and rhythm were monitored continuously. Arterial blood pressure was monitored directly, and arterial blood collected for pH and blood gas analyses. When arterial PaO2 fell below 9.3 kPa (70 mm Hg) and failed to respond to corrective measures including positive pressure ventilation and treatment of hypotension (mean arterial blood pressures <70 mm Hg), a salbutamol aerosol (2 µg kg?1) was delivered via the endotracheal tube. Twenty minutes later, a second arterial blood sample was analysed. Results There were no significant differences in mean arterial blood pressure, heart rate, arterial pH, base excess and bicarbonate before and after treatment. Arterial O2 tension increased significantly from a mean ± SD of 8.3 ± 1.7 kPa (62.4 ± 13.1 mm Hg) before administration to 15.9 ± 9.8 kPa (119.4 ± 57.7 mm Hg) after treatment. There was a small but significant decrease in PaCO2 from 7.4 ± 1.5 kPa (55.2 ± 11.2 mm Hg) to 7.0 ± 1.3 kPa (52.9 ± 9.8 mm Hg) between sample times. No changes in heart rhythm were observed. A high percentage (approximately 70%) of animals sweated following treatment. Conclusions Salbutamol administered at a dose of 2 µg kg?1 via the endotracheal tube of anaesthetized horses with PaO2 values less than 9.3 kPa (70 mm Hg) resulted in an almost two‐fold increase in PaO2 values within 20 minutes of treatment. No changes in heart rate or mean arterial blood pressure were associated with the use of salbutamol in this study. The improvement in PaO2 may be a result of bronchodilatation and improved ventilation, increased perfusion secondary to an increase in cardiac output, or a combination of these two factors. Cardiac output and ventilation–perfusion distribution were not measured in this study; therefore, the reason for the increase in PaO2 values cannot be conclusively determined. Clinical relevance Administration of a salbutamol aerosol is a simple but effective technique that can be used to improve PaO2 values in hypoxaemic horses during inhalant anaesthesia with no apparent detrimental side effects.  相似文献   

17.
Trimetoquinol (TMQ) is a very potent and fast acting bronchodilator in horses with heaves. This study assessed the plasma and urinary concentrations of TMQ in horses with heaves following administration via the intravenous (IV, 0.2 μg/kg) and intra‐tracheal (IT, 2 μg/kg) routes. TMQ was administered to six horses affected with heaves (RAO – Recurrent Airway Obstruction, used interchangeably) by the above routes and plasma and urine samples collected and stored at ?20 °C until analyzed. Solid Phase Extraction (SPE) of TMQ was followed by highly sensitive ESI(+)‐LC‐MS‐MS (ElectroSpray Ionization, positive mode – Liquid Chromatography – Mass Spectrometry – Mass Spectrometry); with a Limit of Detection (LOD) estimated at 1 pg/mL. Following IV administration, TMQ plasma levels peaked at 1 min at 707 pg/mL, and at 9 min at 306 pg/mL following IT administration. Our results show that TMQ plasma concentrations decline rapidly following IV administration, which is consistent with the fast onset and short duration of TMQ effect that was observed in our previous studies. On the other hand, IT administration showed a very unique plasma concentration pattern. From a regulatory standpoint, the current available TMQ ELISA kit was also used in an attempt to detect TMQ from the plasma and urine samples. We report that the ELISA kit was unable to detect TMQ from any of the samples generated in these studies.  相似文献   

18.
Heaves, a condition associated with airway neutrophilia, is believed to result from an allergic response to environmental dust particles. However, the contribution of neutrophils to the allergic response is poorly understood. It has been hypothesized that Th2-type cytokines can directly activate neutrophils to produce pro-inflammatory mediators. The present study focused on the presence of receptors for the Th2-type cytokines interleukin (IL)-5 and IL-9 on peripheral blood neutrophils of horses with heaves. Neutrophils were isolated from peripheral blood of horses with heaves (n=7), and normal control (n=5) before (pasture) and 3 weeks following a continuous natural allergen challenge (stabling). Horses with heaves had significantly increased numbers of neutrophils expressing IL-5 and IL-9 receptors compared to control while in pasture, and further increased during stabling in heaves affected horses but not in control animals. These results provide a possible mechanism by which Th2-type cytokines may activate neutrophils in equine heaves.  相似文献   

19.
Objective The study aimed to investigate the effect of varying pulse lengths of inhaled nitric oxide (iNO), and 2.5 hours of continuous pulse‐delivered iNO on pulmonary gas exchange in anaesthetized horses. Study Design Experimental study. Animals Six Standardbred horses. Methods Horses received acepromazine, detomidine, guaifenesin, thiopentone and isoflurane in oxygen, were positioned in dorsal recumbency and were breathing spontaneously. iNO was on average pulsed during the first 20, 30, 43 or 73% of the inspiration in 15 minute steps. The pulse length that corresponded to the highest (peak) partial pressure of arterial oxygen (PaO2) in the individual horses was determined and delivered for a further 1.5 hours. Data measured or calculated included arterial and mixed venous partial pressures of O2 and CO2, heart rate, respiratory rate, expired minute ventilation, pulmonary and systemic arterial mean pressures, cardiac output and venous admixture. Data (mean ± SD) was analysed using anova with p < 0.05 considered significant. Results Although the pulse length of iNO that corresponded to peak PaO2 varied between horses, administration of all pulse lengths of iNO increased PaO2 compared to baseline. The shortest pulse lengths that resulted in the peak PaO2 were 30 and 43% of the inspiration. Administration of iNO increased PaO2 (12.6 ± 4.1 kPa [95 ± 31 mmHg] at baseline to a range of 23.0 ± 8.4 to 25.3 ± 9.0 kPa [173 to 190 mmHg]) and PaCO2 (8.5 ± 1.2 kPa [64 ± 9 mmHg] to 9.8 ± 1.5 kPa [73 ± 11 mmHg]) and decreased venous admixture from 32 ± 6% to 25 ± 6%. The increase in PaO2 and decrease in venous admixture was sustained for the entire 2.5 hours of iNO delivery. Conclusions The improvement in arterial oxygenation during pulsed delivery of iNO was significant and sustained throughout 2.5 hours of anaesthesia. Clinical relevance Pulsed iNO potentially could be used clinically to counteract hypoxemia in anaesthetized horses.  相似文献   

20.
Heaves is a common condition of horses of cold climate that is characterized by small airway inflammation and obstruction following exposure of susceptible horses to moldy hay and straw. It has been shown that helper T lymphocytes (Th) orchestrate the inflammatory response in asthma and in various animal models of allergic lung diseases by the release of Th2-type cytokines. Results of previous studies indicate that a predominant expression of Th2-type response by airway cells may also be present in heaves. To evaluate the temporal mRNA expression of Th1 (IFN-gamma) and Th2 (IL-4, IL-5) type cytokines in heaves and their relationship to clinical disease, we studied the pulmonary mechanics and cytokine mRNA expression (IL-4, IL-5 and IFN-gamma) in bronchoalveolar lavage lymphocytes of horses with heaves (n=6) and control (n=6) before and after 24h and 9 days of continuous natural inhalation challenge. Starting 24h after challenge horses with heaves, but not control horses, had a significant increase in pulmonary elastance and the number of lymphocytes expressing mRNA for IL-4 and IL-5. These changes were further increased at 9 days, at which time the number of cells positive for IFN-gamma mRNA was decreased. In this study we have shown that BAL lymphocytes of horses with heaves during clinical exacerbation have a predominant Th2-type cytokine response and that this response coincides in time with the presence of airway obstruction.  相似文献   

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