Inflammatory and contractile profile in LPS-challenged equine isolated bronchi: Evidence for IL-6 as a potential target against AHR in equine asthma.

BACKGROUND: Airway inflammation and airway hyperresponsiveness (AHR) are pivotal characteristics of equine asthma. Lipopolysaccharide (LPS) may have a central role in modulating airway inflammation and dysfunction. Therefore, the aim of this study was to match the inflammatory and contractile profile in LPS-challenged equine isolated bronchi to identify molecular targets potentially suitable to counteract AHR in asthmatic horses. METHODS: Equine isolated bronchi were incubated overnight with LPS (0.1-100 ng/ml). The contractile response to electrical field stimulation (EFS) and the levels of cytokines, chemokines, and neurokinin A (NKA) were quantified. The role of capsaicin sensitive-sensory nerves, neurokinin-2 (NK2) receptor, transient receptor potential vanilloid type 1 receptors (TRPV1), and epithelium were also investigated. RESULTS: LPS 1 ng/ml elicited AHR to EFS (+238.17 ± 25.20% P < 0.001 vs. control). LPS significantly (P < 0.05 vs. control) increased the levels of IL-4 (+36.08 ± 1.62%), IL-5 (+38.60 ± 3.58%), IL-6 (+33.79 ± 2.59%), IL-13 (+40.91 ± 1.93%), IL-1ß (+1650.16 ± 71.16%), IL-33 (+88.14 ± 8.93%), TGF-ß (22.29 ± 1.03%), TNF-α (+56.13 ± 4.61%), CXCL-8 (+98.49 ± 17.70%), EOTAXIN (+32.26 ± 2.27%), MCP-1 (+49.63 ± 4.59%), RANTES (+36.38 ± 2.24%), and NKA (+112.81 ± 6.42%). Capsaicin sensitive-sensory nerves, NK2 receptor, and TRPV1 were generally involved in the LPS-mediated inflammation. Epithelium removal modulated the release of IL-1ß, IL-33, and TGF-ß. Only the levels of IL-6 fitted with AHR to a wide range of EFS frequencies, an effect significantly (P < 0.05) inhibited by anti-IL-6 antibody; exogenous IL-6 induced significant (P < 0.05) AHR to EFS similar to that elicited by LPS. CONCLUSION: Targeting IL-6 with specific antibody may represent an effective strategy to treat equine asthma, especially in those animals suffering from severe forms of this disease.

Isolated airways in equine respiratory pharmacology: They never lie.

Pre-clinical studies on human isolated bronchi have relevant translational value in human in vivo, conversely no investigation has been performed to assess whether data resulting from equine isolated airways can have any translational application in asthmatic horses. Thus, a meta-regression analysis via random-effect method was carried out to correlate the pharmacological characteristics of bronchodilators resulting from experiments performed in equine isolated bronchi with their impact on the lung function outcomes in asthmatic horses. Data on the potency of different bronchodilators were extracted from four ex vivo studies involving 68 horses, and related with the maximum change in transpulmonary pressure (ΔPplmax), pulmonary resistance (RL), and dynamic lung compliance (Cdyn) resulting from the meta-analysis of clinical trials aimed to assess the effect of different bronchodilator classes, namely antimuscarinic agents and ß2-adrenoreceptor (ß2-AR) agonists, on lung function of asthmatic horses. The potency (pEC50) detected in equine isolated bronchi for each specific bronchodilator did not significantly (P > 0.05) influence the bronchorelaxant effect resulting from clinical trials. RL was characterized by a flatter meta-regression line (slope 0.01, 95%CI -0.25 - 0.28) with respect to ΔPplmax (slope 0.90, 95%CI -4.06 - 2.26) and Cdyn (slope 0.09, 95%CI -0.21 - 0.04). The quality of evidence was moderate for RL and ΔPplmax and low for Cdyn. This quantitative synthesis provides the indirect evidence that pre-clinical investigations performed by using equine isolated airways may produce useful data to predict the impact of bronchodilators on the RL of asthmatic horses. Further translational studies are needed to directly confirm the results of this research.

Effect of lipopolysaccharide on the responsiveness of equine bronchial tissue.

Recurrent airway obstruction (RAO) is a main characteristic of horses with severe equine asthma syndrome. The presence of bacterial lipopolysaccharide (LPS) in the airways of horses is thought to play a crucial role in the clinical expression of this disorder. This study pharmacologically characterized the effect of LPS on the responsiveness of equine bronchial tissue. Equine isolated bronchi were incubated overnight with LPS (0.1-100 ng/ml) and then stimulated by electrical field stimulation (EFS). The role of capsaicin sensitive-sensory nerves (capsaicin desensitization treatment), neurokinin-2 (NK2) receptors (blocked by GR159897), transient receptor potential vanilloid type 1 receptors (TRPV1; blocked by SB366791), and neurokinin A (NKA) were investigated. Untreated bronchi were used as control tissues. LPS (1 ng/ml) significantly increased the EFS-evoked contractility of equine bronchi compared with control tissues (+742 ± 123 mg; P < 0.001). At higher concentrations LPS induced desensitization to airways hyperresponsiveness (AHR; EC50: 5.9 ±â€¯2.6 ng/ml). Capsaicin desensitization and GR159897 significantly prevented AHR induced by LPS at EFS1-50Hz (-197 ±â€¯25%; P < 0.01). SB366791 inhibited AHR at very low EFS frequency (EFS1Hz -193 ±â€¯29%; P < 0.01 vs. LPS-treated bronchi). LPS (1 ng/ml) significantly (P < 0.01) increased 3.7 ±â€¯0.7 fold the release of NKA compared with control bronchi. LPS induces biphasic dysfunctional bronchial contractility due to the stimulation of capsaicin sensitive-sensory nerves, increased release of NKA, and activation of NK2 receptors, whereas TRPV1 receptors appear to play a marginal role in this response. The overnight challenge with low concentrations of LPS represents a suitable model to investigate pharmacological options that may be of value in the treatment of equine RAO.

Pharmacological characterization of the interaction between tiotropium and olodaterol administered at 5:5 concentration-ratio in equine bronchi.

Equine airways represent a suitable ex vivo model to study the functional impact of pharmacological treatments on human chronic obstructive pulmonary disorders, such as asthma and chronic obstructive pulmonary disease (COPD). We aimed to characterize the pharmacological interaction between the long-acting muscarinic antagonist (LAMA) tiotropium and the long-acting ß2-agonist (LABA) olodaterol in equine airways. The effect of tiotropium and olodaterol, administered alone and in combination at the ratio of concentrations reproducing ex vivo the concentration-ratio delivered by the currently available fixed-dose combination (FDC) (5:5), was investigated on the cholinergic contractile tone induced by the parasympathetic activation of equine isolated airways. The drug interaction was analysed by using the Bliss Independence and Unified Theory models. Both tiotropium and olodaterol induced a sub-maximal concentration-dependent inhibition of bronchial contractility (Emax: tiotropium 83.6 ± 14.8%, olodaterol 76.9 ± 17.9%; pEC50: tiotropium 8.2 ± 0.5; olodaterol 8.3 ± 0.6). When administered at 5:5 concentration-ratio, tiotropium plus olodaterol completely inhibited the bronchial contractility (Emax 102.7 ± 8.4%; pEC50 9.0 ± 0.7). Strong synergistic interaction was detected for tiotropium/olodaterol combination (combination index 0.011). When administered at low concentrations, the drug mixture elicited up to 94.6 ± 9.5% effect that was 36.0 ± 8.1% greater than the expected additive effect. The results of this study demonstrate that the co-administration of tiotropium plus olodaterol at 5:5 concentration-ratio leads to synergistic inhibition of equine bronchial contractility when compared with either drug administered alone. These findings suggest that the currently available LABA/LABA FDC may be effective in delivering tiotropium/olodaterol combination at equipotency concentrations of each monocomponent into the lung and, thus, inducing synergistic effect in the airways.

Listeriosis in pregnancy: a case report.

Listeria monocytogenes is an alimentary infection which can be extremely dangerous for pregnant women. A 34-year-old pregnant woman was hospitalized with fetal cardiac rate alterations and influenza-like symptoms. A caesarean section due to fetal distress was performed. A maternal-fetal listeriosis diagnosis was possible only after the birth through bacteriological and histological examination on both the placenta and the newborn.

The search for thrombophilic gene mutations in women with gestational hypertension does not help in predicting poor pregnancy outcome.

OBJECTIVE: To evaluate whether genetic thrombophilic mutations, biochemical and biophysical indices help to predict pregnancy outcome in women with gestational hypertension. DESIGN AND METHODS: A group of 59 women with gestational hypertension were prospectively tested between 24 and 26 weeks of gestation for: (i) DNA analysis to search for gene mutations of Factor V Leiden, prothrombin, methylenetetrahydrofolate reductase and plasminogen activator inhibitor type 1 (PAI-I) polymorphism; (ii) maternal serum concentrations of homocysteine and PAI-1, activated protein resistance and Factor II:C activity levels; (iii) mean uterine arterial resistance index (RI) by Doppler velocimetry; and (iv) history of hypertensive disorders in relatives (the mother and/or the father). Pregnancy outcome was evaluated, and considered 'poor' when patients developed severe pre-eclampsia, haemolysis-elevated liver enzymes-low platelets (HELLP) syndrome, fetal growth restriction (FGR), thromboembolic complications and disseminated intravascular coagulopathy (DIC). RESULTS: Eighteen women had a poor pregnancy outcome (11 with severe pre-eclampsia, of whom two had superimposed FGR; three with full HELLP syndrome, of whom one had DIC; four with FGR) and delivered, by emergency Caesarean section, neonates with a significantly lower mean gestational age (P < 0.0001) and birthweight (P < 0.0001). History of hypertensive disorders was significantly (P < 0.001) more common in the women group with poor (11 of 18) than normal (10 of 41) outcome. In addition, patients with a poor pregnancy outcome did not have a higher incidence of gene polymorphisms incidence, but significantly (P < 0.01) higher Factor II:C activity levels and significantly (P < 0.0001) higher mean uterine arterial RI than women with normal pregnancy outcome. CONCLUSIONS: Only Factor II:C activity levels, uterine arterial Doppler and a history of familial hypertension are useful in predicting poor pregnancy outcome in gestational hypertension.

Maternal position during non-stress test and fetal heart rate patterns.

OBJECTIVE: The aim of the study was to determinate whether maternal position during the non-stress test (NST) in different weeks of pregnancy influences fetal heart rate patterns. MATERIALS AND METHODS: A total of 1055 NST lasting 30 min were performed in 368 autochthonous mothers with low-risk pregnancies. On the basis of maternal position during the test we divided into three groups: reclining, sitting, and walking. The cardiotocographic parameters considered were: number of minutes of reactive NST with minimum length, number of fetal movements, fetal heart rate baseline, number of large accelerations, number of dubious NST, and number of variable decelerations. RESULTS: Fetal heart rate patterns in low-risk pregnancies were studied using NST in different gestational ages and in different maternal positions. Differences in heart rate were found in relationship to both gestational age and maternal position. The minimum length of NST necessary to record at least three large accelerations was significantly different in relationship to both gestational age and maternal position. The number of fetal movements perceived by the mother was greater in the reclining position than in sitting or walking. Together with the progression of pregnancy, the number of dubious NST decreased in all subgroups, especially in the sitting position. The greatest number of variable decelerations was observed in the reclining position and it was increased with pregnancy progression. The NST duration did not vary greatly in the reclining position, but in the sitting position or during walking, the time taken to record the three large accelerations required to define the trace as reactive, decreased significantly with the progression of pregnancy CONCLUSIONS: Non-stress test in sitting position or during walking should be encouraged because fetal reactivity is more quickly observed.