Intra-articular triamcinolone acetonide improves lung function in horses with severe asthma.

BACKGROUND: Locally administered corticosteroids are commonly used to treat joint diseases in sport and racehorses. As they are also the most potent drugs for the treatment of equine asthma, we hypothesised that the intra-articular corticosteroids used to treat joint diseases also improve the lung function in horses with severe asthma, thus potentially delaying the diagnosis of this common lung condition. OBJECTIVES: To compare the effects of intra-articular (IA) and intramuscular (IM) triamcinolone acetonide (TA) on lung function in horses with severe asthma. STUDY DESIGN: Randomised and controlled experiment on asthma-prone research animals. METHODS: Horses with severe asthma in clinical exacerbation were given either 20 mg of TA in both tarsocrural joints (n = 5; 40 mg/horse) or 40 mg of TA intramuscularly (n = 5). Lung function and TA serum concentrations were measured weekly for 35 days. TA serum concentrations were also evaluated on day 3. RESULTS: The pulmonary resistance (RL ) and elastance (EL ) values decreased by day 7 in the IA group (P<0.0001 and P = 0.003, respectively) and by day 14 in the IM group (P = 0.002 and 0.03, respectively). Lung function was improved up to days 21 and 28 in the IA and IM groups, respectively, when compared with baseline. TA serum levels were below the quantification limit (100 pg/ml) for 4 and 3 of the 5 horses in the IA and IM groups, respectively, on day 7. The area under the curve for RL , EL and the serum concentrations of TA were similar in both groups. MAIN LIMITATIONS: The response of horses with severe asthma might differ from that of high-performance horses with mild/moderate asthma. CONCLUSIONS: Intra-articular administration of TA improves lung function in horses with severe asthma, an effect that persists when TA serum concentration is below the quantification level that is employed as a threshold by the International Association of Racing Commissioners.

Effect of different doses of inhaled ciclesonide on lung function, clinical signs related to airflow limitation and serum cortisol levels in horses with experimentally induced mild to severe airway obstruction.

BACKGROUND: Inhaled corticosteroids are effective for the treatment of equine asthma but they induce cortisol suppression with potential side effects. OBJECTIVES: To study the efficacy of ciclesonide, an inhaled corticosteroid with an improved safety profile, on lung function, clinical signs related to airway obstruction, and serum cortisol levels in asthmatic horses exposed to a mouldy hay challenge. STUDY DESIGN: Cross-over placebo controlled, blinded, randomised experiment. METHODS: Sixteen horses were enrolled in three subsequent dose-titration studies (8 horses/study) to investigate the effects of inhaled ciclesonide administered for 2 weeks at doses ranging from 450 to 2700 µg twice daily or 3712.5 µg once daily. Systemic dexamethasone (0.066 mg/kg per os) was our positive control. A placebo group was also studied. Lung function and clinical scores were blindly performed before and after 7 and 14 days of treatment. Serum cortisol was measured before and after 3, 5, 7, 10, 14 days of treatment as well as 3 and 7 days post treatment. RESULTS: After 7 days, dexamethasone induced a significant reduction in pulmonary resistance (from 2.5 ± 0.6 at day 0 to 1.1 ± 0.7 cm H2 O/L/s), pulmonary elastance (5.0 ± 2.6 to 1.2 ± 1.0 cm H2 O/L), and of the weighted clinical score (14.8 ± 4.7 to 8.0 ± 4.4). Similarly, ciclesonide 1687.5 µg twice daily significantly improved pulmonary resistance (2.7 ± 1.1 to 1.6 ± 0.8 cm H2 O/L/s), pulmonary elastance (5.2 ± 3.1 to 2.2 ± 1.3 cm H2 O/L), and weighted clinical score (13 ± 2.9 to 10.8 ± 4.2). Serum cortisol suppression (<50 nmol/L) systematically occurred with dexamethasone from day 3 of treatment up to day 3 post treatment, but not with ciclesonide at any tested doses. Placebo did not exert any significant beneficial effect. MAIN LIMITATIONS: Experimentally induced asthma exacerbations in horses might respond differently to treatment than naturally occurring exacerbations. CONCLUSIONS: Inhaled ciclesonide is an effective treatment for horses with equine asthma. Serum cortisol was unaffected by treatment.

Nebulisation of dexamethasone sodium phosphate for the treatment of severe asthmatic horses.

BACKGROUND: Inhaled corticosteroids are effective in the treatment of equine asthma. A recent study reported that nebulisation of injectable dexamethasone had low systemic bioavailability in healthy horses and could represent a cost-effective therapy for equine inflammatory lung diseases. OBJECTIVES: To determine the effects of dexamethasone nebulisation on lung function in severe asthmatic horses. It was hypothesised that dexamethasone administered by nebulisation would be more effective than the same dose administered orally. STUDY DESIGN: Randomised blinded experimental study in severe asthmatic horses. METHODS: Twelve severe asthmatic horses in clinical exacerbation were randomly assigned to treatment with 5 mg of dexamethasone sodium phosphate by nebulisation (n = 6) or by oral administration (n = 6), once daily for 7 days. Lung function was evaluated at baseline, after four treatment days (D4) and 24 h after the last dose (D8). The presence of residual bronchospasm was assessed on D8 with N-butylscopolammonium bromide administration (0.3 mg/kg i.v.). A respiratory clinical score was performed daily. Serum cortisol concentration was measured at baseline, D4 and D8. RESULTS: The pulmonary elastance was unchanged in both groups while pulmonary resistance was significantly improved in the oral group on D8 (mean reduction in 1 cm H2 O/L/s [CI: 0.34-1.65, P = 0.003]). All horses had residual bronchospasm at the end of the study. There was a group difference in the respiratory clinical score as it was significantly reduced in the oral group, from D5 to D8. Serum cortisol concentration decreased in all subjects. MAIN LIMITATIONS: Low number of horses and lack of placebo group. CONCLUSIONS: Considering the lack of improvement of lung function and the hypothalamic-pituitary-adrenal axis suppression, the results of this study do not support aerosolisation of an injectable form of dexamethasone for the treatment of severe equine asthma at the dose and with the nebuliser evaluated.

Efficacy of inhaled budesonide for the treatment of severe equine asthma.

BACKGROUND: Corticosteroids are the most potent drugs for the control of severe equine asthma, but adverse effects limit their chronic systemic administration. Inhaled medications allow for drug delivery directly into the airways, reducing the harmful effects of these drugs. OBJECTIVES: To evaluate the efficacy of inhaled budesonide specifically formulated for the equine use and administered by a novel inhalation device in horses with severe asthma. STUDY DESIGN: Experimental studies in horses with naturally occurring asthma with cross-over, randomised, blinded experimental designs. METHODS: In Study 1, budesonide (1800 µg twice daily) administered using a novel Respimat® based inhaler was compared to i.v. dexamethasone (0.04 mg/kg). In Study 2, 3 doses of budesonide (450, 900, and 1800 µg) were compared to oral dexamethasone (0.066 mg/kg). Lung function, bronchoalveolar fluid cytology (Study 1), CBC, serum chemistry, and serum cortisol and adrenocorticotropic hormone (ACTH) values were evaluated. RESULTS: In Study 1, there was a marked and significant improvement in the lung function of all horses treated with budesonide and dexamethasone. Neutrophil percentages in bronchoalveolar fluid decreased in all horses treated with dexamethasone and in four of six horses treated with budesonide. Serum cortisol and blood ACTH concentrations decreased with both treatments. In Study 2, there was a significant improvement in the lung function with all dosages of budesonide, and the effects of higher dosages were comparable to those of dexamethasone. Dexamethasone and budesonide at the two higher dosages induced a significant decrease of cortisol concentrations. MAIN LIMITATIONS: The Respimat® based inhaler is not currently commercially available. CONCLUSIONS: Administration of budesonide with the Respimat® based inhaler provided dose-dependent relief of airway obstruction in horses with severe asthma, but also a suppression of serum cortisol.

Bronchoalveolar lavage fluid neutrophilia is associated with the severity of pulmonary lesions during equine asthma exacerbations.

BACKGROUND: The severe form of equine asthma is associated with pathological changes of the peripheral airways and pulmonary parenchyma that are only partly described. Also, the relationship between these structural alterations and the percentage of neutrophils found within the airway lumen, assessed by bronchoalveolar lavage fluid (BALF) cytology, remains ill-defined. OBJECTIVE: To examine the histological lesions associated with equine asthma during disease exacerbation and remission, and their relationship with lung function and BALF neutrophilia. STUDY DESIGN: Observational retrospective study. METHODS: Peripheral lung tissues, BALF cytology and lung function data from 61 horses (22 controls, 24 asthma exacerbations and 15 asthma remission) were obtained from an equine pulmonary tissue bank. Two pathologists semi-quantitatively assessed histological features, including airway wall inflammation, interstitial fibrosis, mucus cell hyperplasia, mucostasis, peribronchiolar metaplasia, presence of granuloma and the overall severity of these lesions. RESULTS: Mucostasis, mucus cell hyperplasia, peribronchiolar metaplasia and interstitial fibrosis were associated with disease exacerbation (P≤0.05), and these changes were all attenuated during remission. Airway wall inflammation was greater in horses with asthma in exacerbation compared with horses with asthma in remission and control horses (P≤0.05). Acute (neutrophilic) airway wall inflammation was more frequently detected in asthmatic cases compared with control horses (P<0.0001) and was associated with BALF neutrophilia >5% in control horses (P = 0.002). The degree of bronchiolar inflammation was higher in asthmatic horses in remission stabled and treated pharmacologically compared with those kept on pasture (P = 0.04). MAIN LIMITATIONS: Samples obtained from a convenient cohort of horses were studied. CONCLUSIONS: Severely asthmatic horses present parenchymal and peribronchial/peribronchiolar lesions possibly contributing to the obstructive nature of the disease.

Age associated changes in peripheral airway smooth muscle mass of healthy horses.

Peripheral airway smooth muscle (ASM) mass is increased in severe equine asthma, but no information is available on age related changes in ASM. In this study, peripheral ASM dimensions were determined in healthy horses of different ages. The thickness of the peripheral ASM layer was constant in horses of different ages, but ASM occupied a greater proportion of the inner wall area in young horses compared to older horses. This finding suggests that equine airways experience a decrease in the relative abundance of ASM with age.

Development of a Semiquantitative Histological Score for the Diagnosis of Heaves Using Endobronchial Biopsy Specimens in Horses.

BACKGROUND: Remodeling of the peripheral airways persists during the asymptomatic phase of heaves. Assessing the histology of large bronchi could facilitate the diagnosis of heaves during remission of the disease. HYPOTHESIS: Airway inflammation and remodeling in endobronchial biopsy (EBB) specimens differentiate horses with heaves from controls, independently of their clinical status (exacerbation or remission). ANIMALS: Fourteen healthy horses and 24 horses with heaves. METHODS: A 14-point scoring system assessing central bronchial wall inflammation and remodeling was developed. The score was validated by 2 pathologists using specimens obtained from 18 horses (6 controls, 6 with heaves exacerbation, and 6 with heaves remission) in which lung function had been assessed with impulse oscillometry. Clinical and research application of the score was evaluated using biopsy specimens obtained from 20 additional horses (8 controls, 6 with heaves exacerbation, and 6 with heaves remission). RESULTS: The score was repeatable (interclass correlation coefficient = 69%). It differentiated horses with heaves in exacerbation (mean ± SD: 6.2 ± 2.2) from those in remission (4.0 ± 1.0) and controls (3.6 ± 1.7, P < 0.0001). The histological scores of horses with heaves correlated with the ratio of respiratory resistance (R) at 5 and 10 Hz (R5 : R10 ratio, r = 0.65, P = 0.03), a parameter assessing airway obstruction. CONCLUSIONS AND CLINICAL SIGNIFICANCE: The proposed histological scoring system correlates with the degree of airway obstruction measured by impulse oscillometry. However, it does not discriminate horses with heaves in remission from controls. Evaluation of EBB specimens might be considered in future research and clinical studies of respiratory diseases in horses.

Analysis of genomic copy number variation in equine recurrent airway obstruction (heaves).

We explored the involvement of genomic copy number variants (CNVs) in susceptibility to recurrent airway obstruction (RAO), or heaves-an asthmalike inflammatory disease in horses. Analysis of 16 RAO-susceptible (cases) and six RAO-resistant (control) horses on a custom-made whole-genome 400K equine tiling array identified 245 CNV regions (CNVRs), 197 previously known and 48 new, distributed on all horse autosomes and the X chromosome. Among the new CNVRs, 30 were exclusively found in RAO cases and were further analyzed by quantitative PCR, including additional cases and controls. Suggestive association (P = 0.03; corrected P = 0.06) was found between RAO and a loss on chromosome 5 involving NME7, a gene necessary for ciliary functions in lungs and involved in primary ciliary dyskinesia in humans. The CNVR could be a potential marker for RAO susceptibility but needs further study in additional RAO cohorts. Other CNVRs were not associated with RAO, although several involved genes of interest, such as SPI2/SERPINA1 from the serpin gene family, which are associated with chronic obstructive pulmonary disease and asthma in humans. The SPI2/SERPINA1 CNVR showed striking variation among horses, but it was not significantly different between RAO cases and controls. The findings provide baseline information on the relationship between CNVs and RAO susceptibility. Discovery of new CNVs and the use of a larger population of RAO-affected and control horses are needed to shed more light on their significance in modulating this complex and heterogeneous disease.

Endoscopic Evaluation of Angiogenesis in the Large Airways of Horses with Heaves Using Narrow Band Imaging.

BACKGROUND: Heaves is a severe debilitating condition of horses, characterized by lower airway inflammation and permanent structural changes of the bronchial wall. Chronic inflammation promotes the formation of new vessels, a phenomenon known as angiogenesis. Narrow band imaging (NBI) endoscopy is a noninvasive technique that enhances the visualization of submucosal vessels, and commonly is employed for the study of angiogenesis in human patients. OBJECTIVES: Using NBI, we aimed to determine whether or not the central airways of horses with heaves undergo angiogenesis. ANIMALS: Horses with heaves during exacerbation of the disease (n = 5) and healthy controls (n = 6). METHODS: A library of NBI images was established from previously recorded videoendoscopies. Images were acquired by an operator blinded to horse ID. Images were obtained from 3 sites: 130 from the trachea (14 ± 9.3 [mean ± SD] images per horse with heaves and 10 ± 5.4 from controls; P = .45), 58 from the carina (5.4 ± 3.2 from horses with heaves and 5.2 ± 2.8 fromn controls; P > .99) and 167 from the intermediate bronchi (17.8 ± 6.7 from horses with heaves and 13 ± 5.6 from controls; P = .17). Using dedicated stereology software (NewCAST, Visiopharm; Denmark), the volume density of superficial and deep vessels was calculated blindly by point counting at each site for all horses. RESULTS: In the trachea, the volume density of superficial vessels was increased in horses with heaves compared to controls (P = .02). No difference was found between groups for the volume density of both superficial and deep vessels at the carina or intermediate bronchi. CONCLUSION AND CLINICAL RELEVANCE: NBI imaging of the airways was easily performed in standing sedated horses.

Inflammatory Airway Disease of Horses--Revised Consensus Statement.

The purpose of this manuscript is to revise and update the previous consensus statement on inflammatory airway disease (IAD) in horses. Since 2007, a large number of scientific articles have been published on the topic and these new findings have led to a significant evolution of our understanding of IAD.

Environmental heat and airborne pollen concentration are associated with increased asthma severity in horses.

REASON FOR PERFORMING STUDY: Clinical exacerbations of severe equine asthma (formerly recurrent airway obstruction [RAO]) are more frequently reported during winter when horses are exposed to airborne dusts during stabling. However, we have also observed a worsening of clinical signs on days during a heatwave. OBJECTIVES: To investigate the association between environmental temperature and humidity and clinical signs of asthma in horses during clinical exacerbation of the disease. STUDY DESIGN: Retrospective longitudinal study. METHODS: Historical data on 14 severe asthmatic horses exposed to a dusty environment and evaluated using a previously validated clinical scoring system were analysed. Barn temperature and relative humidity values were obtained and air enthalpy (h) calculated. Correlation tests were used to study the relationship between mean daily clinical scores of horses and environmental variables. Lung function parameters recorded at 4 day intervals during hot (25°C) and warm (18°C) barn conditions were compared using a paired t test. RESULTS: Significant positive correlations were observed between the mean daily clinical score and temperature (r = 0.58, P = 0.01) and air enthalpy (r = 0.55, P = 0.02). Maximal daily temperature correlated with airborne pollen concentrations (r = 0.51, P = 0.0002). In the absence of changes in the management of horses, higher barn temperature and enthalpy were associated with increased transpulmonary pressure (P = 0.005), pulmonary resistance (P = 0.008) and elastance values (P = 0.005). CONCLUSIONS: Providing a cold environment may help attenuate the severity of airway obstruction in uncontrolled exacerbations of severe equine asthma. Furthermore, variations in environmental heat and associated pollen concentrations should also be taken into account when evaluating the response to therapy in clinical or research settings.

Serum Surfactant Protein D and Haptoglobin as Potential Biomarkers for Inflammatory Airway Disease in Horses.

BACKGROUND: The identification of serum biomarkers of lung inflammation would facilitate the diagnosis of inflammatory airway disease (IAD) in horses. HYPOTHESIS: Horses with IAD have higher serum concentrations of markers of inflammation compared to controls. ANIMALS: Twelve horses with IAD and 10 control horses. METHODS: This was a prospective case-control study. Blood and BALF were collected from horses with IAD and controls. Serum concentration of surfactant protein D (SP-D), haptoglobin, serum amyloid A (SAA) and of the soluble form of triggering receptor expressed on myeloid cells 1 (sTREM-1) was measured using commercial ELISA tests. RESULTS: Horses with IAD had higher serum concentration (log-transformed values) of SP-D (mean ± SD: 1.773 ± 0.51), haptoglobin (6.657 ± 0.202) and SAA (0.128 ± 0.396) compared to controls (0.942 ± 0.226, 6.38 ± 0.22, -0.398 ± 0.319, respectively; P < .01 for all). Furthermore, the concentrations of SP-D and haptoglobin combined allowed differentiating the 2 groups (IAD: 8.43 ± 0.564, controls: 7.322 ± 0.249, P < .0001) with a sensitivity and specificity of 100% when a cut-off of 7.70 (log value) was employed. CONCLUSIONS AND CLINICAL IMPORTANCE: Surfactant protein D and haptoglobin serum concentrations could be a diagnostic aid in IAD. Further studies are necessary to establish the specificity of our findings before they can be applied in everyday practice.

Acute phase proteins in racehorses with inflammatory airway disease.

BACKGROUND: Systemic inflammation is observed in horses with heaves and could also be present in horses with a lesser degree of pulmonary inflammation. HYPOTHESIS/OBJECTIVES: It was hypothesized that racehorses with inflammatory airway disease (IAD) have increased concentration of circulating acute phase proteins. The objective of this study was to compare serum acute phase proteins of racehorses with and without lower airway inflammation. ANIMALS: Serum from 21 client-owned Standardbred racehorses with exercise intolerance and lower airway inflammation and serum from 10 client-owned Standardbred racehorses with exercise intolerance without lower airway inflammation. METHODS: In a case-control study, serum samples from previously characterized horses presented for exercise intolerance with or without lower airway inflammation based on bronchoalveolar lavage fluid cytology were analyzed for serum amyloid A protein (SAA), C-reactive protein (CRP), and haptoglobin using commercial ELISAs. RESULTS: There was no significant differences between groups for SAA (non-IAD versus IAD, median (range): 3.47 (0.06-34.94) versus 6.33 (0.06-80) µg/mL, P = .49), CRP (10.87 (2.05-29.03) versus 4.63 (0.02-31.81) µg/mL, P = .23) or haptoglobin (900.36 (607.99-2018.84) versus 749.54 (530.81-1076.95) µg/mL, P = .09). CONCLUSIONS AND CLINICAL IMPORTANCE: In this population of poorly performing racehorses in training, serum SAA, CRP, and haptoglobin were not helpful in distinguishing between horses with IAD from horses with exercise intolerance from other causes.

Airway wall eosinophilia is not a feature of equine heaves.

The objective of this study was to determine whether eosinophils infiltrate the airway wall of horses with heaves. Eosinophils were evaluated using paraffin embedded lung tissues from six heaves-affected horses in crisis and six aged-matched controls. Slides were stained using Luna's method and eosinophils enumerated using histomorphometric techniques. Total eosinophil counts (expressed per mm(2) of basement membrane) were significantly higher in the airways of controls horses than in horses with heaves. Intraluminal, intraepithelial, and airway smooth muscle eosinophils counts were also increased in control horses. The results suggest that eosinophils do not contribute to the persistent airway obstruction in heaves.

N-butylscopolammonium bromide causes fewer side effects than atropine when assessing bronchoconstriction reversibility in horses with heaves.

REASONS FOR PERFORMING STUDY: Bronchospasm results in airway obstruction in horses with heaves. Atropine is the most potent bronchodilator drug currently available for horses, but is associated with side effects that limit its use. Like atropine, N-butylscopolammonium bromide (NBB) is an anticholinergic agent with bronchodilatory properties. OBJECTIVES: To compare the bronchodilating effects and side effects of atropine and NBB in horses with heaves. STUDY DESIGN: Cross-over experiment using horses with heaves. METHODS: Eight horses with heaves were administered atropine and NBB, using a cross-over design. Heart rate, pupillary dilatation, transrectal palpation, lung mechanics (maximal changes in transpulmonary pressure, pulmonary resistance and elastance) and arterial blood gases were assessed before and 10 and 30 min after drug administration. RESULTS: One horse treated with atropine developed colic. Significant pupillary dilatation was observed only with atropine. Tachycardia developed in all horses, but was more marked with atropine. Lung function improved with both drugs, but elastance values had returned to baseline at 30 min with NBB. There was no improvement in arterial hypoxaemia with either drug. CONCLUSIONS: The study indicated that the bronchodilatory properties of NBB were not statistically different from those of atropine, but were of shorter duration. N-butylscopolammonium bromide was associated with fewer systemic side effects, and therefore NBB should be preferred over atropine when assessing the reversibility of airway obstruction in horses.

Inflammatory stimuli differentially modulate the transcription of paracrine signaling molecules of equine bone marrow multipotent mesenchymal stromal cells.

OBJECTIVE: Osteoarthritis (OA) is a degenerative disease of joint tissues that causes articular cartilage erosion, osteophytosis and loss of function due to pain. Inflammation and inflammatory cytokines in synovial fluid (SF) contribute to OA progression. Intra-articular (IA) injections of multipotent mesenchymal stromal cells (MSCs) are employed to treat OA in both humans and animals. MSCs secrete paracrine pro-inflammatory and anabolic signaling molecules that promote tissue repair. The objective of this study was to investigate the effects of OASF on the gene expression of paracrine signaling molecules by MSCs. METHODS: The effects of Lipopolysaccharide (LPS) and interleukin (IL)-1ß as well as both normal (N) and osteoarthritis (OA) SF stimulations on the expression of paracrine pro-inflammatory (tumor necrosis factor (TNF)-α, IL-1ß, IL-8), modulatory (IL-6) and anabolic (vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-ß1 and insulin-like growth factor (IGF)-1) signaling molecules by equine bone marrow multipotent mesenchymal stromal cells (eBM-MSCs) was investigated employing reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: In contrast with NSF, OASF significantly up-regulated the expression of VEGF in eBM-MSCs. Both NSF and OASF significantly down-regulated the expression of IL-1ß. LPS and IL-1ß significantly increased the expression of pro-inflammatory cytokines (TNF-α, IL-8 and IL-6; and IL-1ß and IL-8 respectively). DISCUSSION: We conclude that the transcription of paracrine signaling molecules in eBM-MSCs is modulated by SF. Furthermore, OA alters the properties of SF and the response of eBM-MSCs. Finally, the effects of LPS or IL-1ß stimulation are distinct to that observed following stimulations with OASF.

A test stand for off-line laser ion source development at TRIUMF.

A test stand for ion source development and laser resonance ionization spectroscopy was built and commissioned at TRIUMF. The test stand is needed to develop efficient ion sources that can function reliably in the hostile, high temperature, high radiation environment of TRIUMF's isotope separator on-line (ISOL) production target ion source. In addition, it enables laser resonance ionization spectroscopy to develop laser excitation schemes suitable for the solid-state laser systems used with TRIUMF's resonant ionization laser ion source . Also, it allows for possible improvement of current ion sources and validation of new designs. The test stand employs a copy of the ion optics used on-line, so that results can be transferred directly to radioactive ion beam production. Due to space restrictions and the need for rapid mass scans, a quadrupole mass spectrometer is used as a mass separator. One of the first experiments conducted on the laser ion source test stand (LIS STAND) was resonant ionization spectroscopy of gallium to improve on the ionization scheme previously used on-line, so that low yield isotopes (e.g., (62)Ga) become available for experiments. Different Rydberg series in gallium were observed and autoionizing states were searched for. The overall LIS STAND system performance, characteristics, and the first resonant ionization spectroscopy are described.

PI3K and MAPKs regulate neutrophil migration toward the airways in heaves.

BACKGROUND: Neutrophils accumulate in the airways of horses with heaves. They likely play an important role in the disease pathogenesis. Understanding the pathways regulating their migration may help identifying new therapeutic targets. HYPOTHESIS: MAPK and PI3K pathways are involved in neutrophil migration toward the airway lumen in heaves. ANIMALS: Twelve heaves-affected horses and 4 healthy horses. METHODS: Migratory activity of bronchoalveolar lavage fluids (BALF) from horses with heaves and healthy horses was compared by means of a Boyden chamber. Involvement of MAPK and PI3K pathways in neutrophil migration was investigated by pretreating neutrophils with inhibitors of p38 MAPK, JNK, MEK1/2, and PI3K. The capacity of a p38 MAPK inhibitor at decreasing neutrophil chemotaxis toward the airways was also evaluated in vivo. RESULTS: BALF from symptomatic heaves-affected horses induced a greater degree of chemokinesis (P = .0004) than BALF from healthy horses. Although all pathways tested were involved in neutrophil migration, inhibition of PI3K was most potent in vitro. An inhibitor of p38 MAPK administered before challenge in horses with heaves did not alter BALF chemokinetic properties. BALF neutrophil percentage and BALF migratory activity were positively correlated after 14 and 35 days of antigen challenge in healthy (P = .05; R(2) = 0.82) and heaves-affected horses (P = .03; R(2) = 0.76), respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: MAPK and PI3K pathways regulate neutrophil migration induced by BALF of horses with heaves. Inhibition of multiple pathways might be required to completely abolish BALF-induced neutrophil migratory activity and possibly inflammation in heaves.