An investigation into the efficacy and mechanisms of action of novel therapeutics for chronic cough

Whilst cough is a defensive reflex, in respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD) the cough reflex may become exaggerated and unproductive, leading to presentation of chronic cough as a troublesome symptom. Chronic cough is the most common reason that patients seek ambulatory care in the UK, and cough medications are one of the largest segments of the global over-the-counter drugs market, yet there are no cough medications (prescription or OTC) available that are both efficacious AND safe, indicating a large unmet clinical need. β-adrenergic receptor (β-AR) agonists, methylxanthines (theophylline) and fatty acid amide hydrogenase inhibitors (FAAHi) are peripherally acting drugs with a proven safety profile in humans for other uses, but are not currently recognised as anti-tussive medications. This thesis aimed to examine whether these drugs possess anti-tussive activity, and if so, the mechanisms by which they inhibit cough. These drugs were all effective at blocking the in vivo cough response to tussive stimuli in naïve guinea pigs, and in addition β-AR agonists and theophylline inhibited tussive stimulus evoked cough in guinea pigs previously exposed to cigarette-smoke, which display a clinically relevant enhanced cough phenotype. In vitro and in vivo assays of guinea pig vagus nerve/neuron activation were used to show that these compounds inhibit depolarisation of airway-innervating peripheral sensory nerves. Pharmacological and genetic tools were used to investigate the receptors and signalling pathways activated by these drugs. Whilst β-AR agonists, theophylline and FAAHi had different mechanisms of action, a common component was that all three classes of compound act on various potassium channels, thereby reducing the excitability of sensory neurons. This work suggests that drugs that inhibit peripheral sensory nerve activity have the potential to be efficacious as anti-tussives. Specifically the compounds tested have improved clinical side-effect profiles over currently used anti-tussives, and therefore have potential as therapies for chronic cough.Open Acces

Effects of Taiji and Strength Training Interventions on Knee Osteoarthritis of Older Adults

Objective. The objective of this study was to evaluate a 10-week Taiji intervention to a 10-week strength training intervention in terms of their ability to relieve osteoarthritis (OA) symptoms, alter gait, and improve mobility in seniors with knee OA. Methods. Men and women between the ages of 60 and 85 years who met the American College of Rheumatology criteria for knee OA were recruited to participate in either a simplified Taiji program (n=12), an open-chain strength training program (n=13), or a control group (n=6). All participants completed the Western Ontario and MacMaster Universities Osteoarthritis Index (WOMAC), three physical performance tests, and a 3-D gait analysis at baseline and again after the 10-week intervention. Results. The strength training group significantly improved on the time up-and-go test (p = 0.001), the WOMAC pain sub-score (p=0.006), WOMAC stiffness sub-score (p\u3c0.001), and WOMAC physical function sub-score (p=0.011). The Taiji group significantly improved on the timed up-and-go (p\u3c0.001), but there was no change in their WOMAC scores. Neither group showed any significant changes in either kinematic or kinetic gait variables. Conclusion. Strength training was effective for improving mobility and improving the symptoms of knee OA. Taiji was also effective for improving mobility, but did not improve the participants‟ knee OA symptoms. Neither intervention had an effect the participants walking gait

The effect of shoe inserts on the kinematics of the lower extremity and center of pressure during treadmill running

Objective: The purpose of this study was to investigate the effect of different orthotic shoe inserts on kinematics of the lower extremity and center of pressure (COP) during treadmill running. Design: The study design was an experimental investigation of five different orthotic insert conditions. Background: Orthotic shoe inserts have been used to treat a wide variety of running injuries. Despite their high success rate, the mode of action of orthotics is not well understood. Orthotics are often prescribed to reduce overpronation that has traditionally been evaluated through tibiocalcaneal eversion. The increased use of three-dimensional (3-D) kinematic methods in recent years has created an emphasis on tibia internal rotation as a component of subtalar joint pronation. No studies have yet shown a systematic effect of a series of medial and lateral heel postings on kinematics during running. Methods: The subtalar joint axes of seven healthy male subjects (mean age: 25.1 ± 2.3 yrs.) were measured, and the subjects performed treadmill running at 3. 8 m s-1 in a running shoe with the factory insoles (control) and four other orthotic conditions: 5 ° lateral post, neutral, 5 ° medial post, and 10° medial post. 3-D kinematic data of the foot and leg segments were captured using a four-camera system at 120 Hz. (Vicon), and COP data were collected with an in-shoe plantar pressure system at 120 Hz. (F-Scan). A oneway repeated measures ANOV A with post hoc comparisons was used to determine significant differences between conditions. Results: The orthotics had no significant effect on frontal plane kinematics. Tibia internal rotation was reduced with the use of a 5 ° medially posted orthotic. • The COP was shifted significantly posteriorly with increasing height of the heel. Conclusions: More studies are needed in order to relate anthropometrics and orthotics to predictable changes in kinematics

Quantifying feed intake and feeding intensity using two experimental conditions and the effect of different feeding strategies on the production parameters of farmed South African abalone, haliotis midae

As abalone are slow-growing animals there is a high investment of capital, running costs and labour in commercial abalone farming. Revenue needs to be maximised by achieving fast growth rates. A foremost driver of abalone growth is feed intake and feeding intensity of the abalone as well as the feeding regimen a farm utilises. While feed intake is well-documented in H. midae, there is a paucity of information regarding this aspect in abalone above 70 g and the relationship between feeding intensity, feed conversion rate (FCR) and daily growth rate needs to be documented. Similarly, there are a limited number of studies dealing with the effects of different pellet types of the same formulation, that differ only in shape and size, on feed intake and production in H. midae. This study made use of both a controlled laboratory experiment and commercial-scale farm experiment with the aim of testing whether feed intake information produced under laboratory conditions can provide good estimates of feed intake under farming conditions, which can further be implemented into feeding strategies on abalone farms. This study quantified daily feed intake (F) in 10 – 20 g, 100 – 110 g and 150 – 160 g abalone weight classes using two different pellet types and determined the relationship between the duration of feed availability and feed intake under laboratory conditions. The effect of three different pellet type strategies (fed daily: a leaf-only strategy = L d-1, a short-pellet only strategy = SP d-1, and a strategy that used both = B d-1) on abalone production parameters under farming conditions such as growth rate, feed conversion ratio (FCR), feeding intensity (FI) and weight variation of 30 – 40 g H. midae was also investigated. A commercial-scale farm study was designed to test the effect of four commercially relevant feeding regimens (three size-specific regimens and one commercially practiced feeding method) on the growth, FCR, feeding intensity and weight variation of these three abalone weight classes while taking into account an economic model to assess the profitability of each feeding regimen. Daily feed intake as a percentage of body mass (% BM d-1) was a function of abalone weight class between the 10 – 20 g and two larger weight classes 100 – 110 g and 150 – 160 g p < 0.0001), however feed intake was not different between the 100 – 110 g and 150 – 160 g weight classes. Pellet type did not affect feed intake in all abalone weight classes (p = 0.15). Feed intake (F) was positively linearly correlated with duration of feed availability (h) in the 10 – 20 g weight class (r2 = 0.76, p <0.00001) and logarithmically correlated in the 100 – 110 g (r2 = 0.25, p < 0.02) and 150 – 160 g (r2 = 0.52, p < 0.0001) weight classes (10 – 20 g abalone-1: 3 F (% BM) = 0.02(h) + 0.1976, 100 – 110 g abalone-1: F (% BM) = log10(h)*0.17 + 0.17, 150 – 160 g abalone-1: F (% BM) = log10(h)*0.36 + 0.07). There was no significant difference in monthly average abalone weight, daily growth rate (G), FCR and feeding intensity between each pellet type strategy (G: p = 0.60, FCR: p = 0.62, FI: p = 0.54 ). However, abalone grew well over the 112-day growth period with average abalone weight increasing significantly between each monthly sample time (pooled pellet type strategy: Huynh-Feldt correction; p < 0.00001). Furthermore, abalone fed the leaf-only pellet type strategy (L d-1) fell into higher weight classes after a 112-day growth period (Z test: 50 – 70 g: 72%) which was 16.1 % higher compared to the SP d-1 and B d-1 strategies. Daily growth rate (r2 = 0.34, p < 0.01) and FCR (r2 = 0.42, p < 0.004) was negatively correlated and FCR was positively correlated with daily feeding intensity, respectively (G = - 2.59 (FI) + 1.526, FCR = 8.8082 (FI) – 2.7108). Feeding regimen affected the production parameters of three abalone weight classes. The method practiced on the farm resulted in the best growth in the 10 – 20 g abalone weight class. The farm feeding method resulted in slower yet more efficient growth rates (lowest FCR values) in the abalone weight classes, 100 – 110 g and 150 – 160 g abalone- 1. However, size-specific feeding regimens resulted in the fastest growth rates but resulted in higher FCR values (less efficient). The relationship between feeding intensity, daily growth rate and FCR all showed that an increase in feeding intensity results in increased daily growth rates and FCR values. The economic model suggests that the higher FCR values associated with size-specific regimens, which have higher associated costs to producing abalone, were greatly outweighed by the growth attained by the abalone in the 100 – 110 g and 150 – 160 g weight classes. The size-specific regimens generated a higher potential monetary value of abalone after a 112-day period, which would consequently result in higher income for abalone farms. For abalone ranging from 100 – 110 and 150 – 160 grams, the economic model suggested that in a quarterly grading schedule (112 days) that abalone be fed the size specific daily rations, which is a function of body mass, at 0.35 % BM d-1 and 0.352 % BM d-1, respectively. The two experimental conditions used in this study produced feed intake and production parameter information that is beneficial to South African abalone farmers. The small-scale laboratory study produced information on feed intake that can be used as reference values as to what abalone in these weight classes can consume on a daily basis. The laboratory study can provide estimates of feed intake under farming conditions but should only be used as minimum 4 values when determining size-specific feeding regimens. To maximise abalone growth, farmers should utilise size-specific feeding regimens for abalone above 30 g. Daily growth rate and FCR can be predicted as a function of the abalone’s feeding intensity. Further studies are needed to determine the effects of abalone weight class on production parameters when testing different pellet types as well as an exploration into behavioural studies focusing on diet preferences. Additionally, future studies need to take into consideration abalone above the weight of 100 g with additional focus of research on behavioural, genetic and environmental aspects on abalone feed intake.Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 202

Efficacy of an ankle orthosis with a subtalar locking system in restricting ankle kinetics and kinematics in lateral cutting

Introduction The ankle joint is the most injured joint during sports participation [1]. Ankle orthoses have been shown to be effective in reducing ankle inversion injuries and are often prescribed for rehabilitation and prevention of lateral ankle sprains. Efficacy of ankle orthoses is often assessed by comparing reduction of passive inversion ROM as well as ankle kinematics between braced and unbraced movements [2,3]. However, joint kinetic responses in lateral cutting were rarely examined. Therefore, the objective of this study was to examine the effectiveness of a new semi-rigid ankle orthosis with a subtalar joint locking mechanism in restricting ankle kinetics and kinematics during a lateral cutting movement

Crown Ether-Metal ‘Sandwiches’ As Linking Mechanisms in Assembled Nanoparticle Films

Crown ether ligands attached to monolayer-protected clusters (MPCs) were assembled as films and the linking mechanism between the crown ether–metal ion–crown ether bridges between nanoparticles was examined. Thicker films exhibited a red shift in the absorbance maximum for the surface plasmon band which was attributed to the increasing aggregation and cross linking within the film. Quantized double layer charging peaks suggest that film growth is selective toward a specific core size or exchange rate, either of which affect the number of potential linking ligands in the periphery of the MPCs. Multi-layer growth of films was only achieved with metal ions capable of coordinating within the cavity of the 15-crown-5 ether. Our exchange reaction parameters are in stark contrast to other types of MPC film assemblies

Tiotropium modulates transient receptor potential V1 (TRPV1) in airway sensory nerves: A beneficial off-target effect?⋆

BackgroundRecent studies have suggested that the long-acting muscarinic receptor antagonist tiotropium, a drug widely prescribed for its bronchodilator activity in patients with chronic obstructive pulmonary disease and asthma, improves symptoms and attenuates cough in preclinical and clinical tussive agent challenge studies. The mechanism by which tiotropium modifies tussive responses is not clear, but an inhibition of vagal tone and a consequent reduction in mucus production from submucosal glands and bronchodilation have been proposed.ObjectiveThe aim of this study was to investigate whether tiotropium can directly modulate airway sensory nerve activity and thereby the cough reflex.MethodsWe used a conscious cough model in guinea pigs, isolated vagal sensory nerve and isolated airway neuron tissue– and cell-based assays, and in vivo single-fiber recording electrophysiologic techniques.ResultsInhaled tiotropium blocked cough and single C-fiber firing in the guinea pig to the transient receptor potential (TRP) V1 agonist capsaicin, a clinically relevant tussive stimulant. Tiotropium and ipratropium, a structurally similar muscarinic antagonist, inhibited capsaicin responses in isolated guinea pig vagal tissue, but glycopyrrolate and atropine did not. Tiotropium failed to modulate other TRP channel–mediated responses. Complementary data were generated in airway-specific primary ganglion neurons, demonstrating that tiotropium inhibited capsaicin-induced, but not TRPA1-induced, calcium movement and voltage changes.ConclusionFor the first time, we have shown that tiotropium inhibits neuronal TRPV1-mediated effects through a mechanism unrelated to its anticholinergic activity. We speculate that some of the clinical benefit associated with taking tiotropium (eg, in symptom control) could be explained through this proposed mechanism of action

Transient receptor potential cation channel, subfamily V, member 4 and airway sensory afferent activation: Role of adenosine triphosphate

BackgroundSensory nerves innervating the airways play an important role in regulating various cardiopulmonary functions, maintaining homeostasis under healthy conditions and contributing to pathophysiology in disease states. Hypo-osmotic solutions elicit sensory reflexes, including cough, and are a potent stimulus for airway narrowing in asthmatic patients, but the mechanisms involved are not known. Transient receptor potential cation channel, subfamily V, member 4 (TRPV4) is widely expressed in the respiratory tract, but its role as a peripheral nociceptor has not been explored.ObjectiveWe hypothesized that TRPV4 is expressed on airway afferents and is a key osmosensor initiating reflex events in the lung.MethodsWe used guinea pig primary cells, tissue bioassay, in vivo electrophysiology, and a guinea pig conscious cough model to investigate a role for TRPV4 in mediating sensory nerve activation in vagal afferents and the possible downstream signaling mechanisms. Human vagus nerve was used to confirm key observations in animal tissues.ResultsHere we show TRPV4-induced activation of guinea pig airway–specific primary nodose ganglion cells. TRPV4 ligands and hypo-osmotic solutions caused depolarization of murine, guinea pig, and human vagus and firing of Aδ-fibers (not C-fibers), which was inhibited by TRPV4 and P2X3 receptor antagonists. Both antagonists blocked TRPV4-induced cough.ConclusionThis study identifies the TRPV4-ATP-P2X3 interaction as a key osmosensing pathway involved in airway sensory nerve reflexes. The absence of TRPV4-ATP–mediated effects on C-fibers indicates a distinct neurobiology for this ion channel and implicates TRPV4 as a novel therapeutic target for neuronal hyperresponsiveness in the airways and symptoms, such as cough