Project description:One of the main challenges in cell therapy for muscle diseases is to efficiently target the muscle. To address this issue and achieve better understanding of in vivo cell fate, we evaluated the relevance of a non-invasive cell tracking method in the Golden Retriever Muscular Dystrophy (GRMD) model, a well-recognised model of Duchenne Muscular Dystrophy (DMD). Mesoangioblasts were directly labelled with 111In-oxine, and injected through one of the femoral arteries. The scintigraphy images obtained provided the first quantitative mapping of the immediate biodistribution of mesoangioblasts in a large animal model of DMD. The results revealed that cells were trapped by the first capillary filters: the injected limb and the lung. During the days following injection, radioactivity was redistributed to the liver. In vitro studies, performed with the same cells prepared for injecting the animal, revealed prominent cell death and 111In release. In vivo, cell death resulted in 111In release into the vasculature that was taken up by the liver, resulting in a non-specific and non-cell-bound radioactive signal. Indirect labelling methods would be an attractive alternative to track cells on the mid- and long-term.
Project description:Clearance of intrapulmonary mucus by the high-velocity airflow generated by cough is the major rescue clearance mechanism in subjects with mucoobstructive diseases and failed cilial-dependent mucus clearance, e.g., subjects with cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD). Previous studies have investigated the mechanical forces generated at airway surfaces by cough but have not considered the effects of mucus biophysical properties on cough efficacy. Theoretically, mucus can be cleared by cough from the lung by an adhesive failure, i.e., breaking mucus-cell surface adhesive bonds and/or by cohesive failure, i.e., directly fracturing mucus. Utilizing peel-testing technologies, mucus-epithelial surface adhesive and mucus cohesive strengths were measured. Because both mucus concentration and pH have been reported to alter mucus biophysical properties in disease, the effects of mucus concentration and pH on adhesion and cohesion were compared. Both adhesive and cohesive strengths depended on mucus concentration, but neither on physiologically relevant changes in pH nor bicarbonate concentration. Mucus from bronchial epithelial cultures and patient sputum samples exhibited similar adhesive and cohesive properties. Notably, the magnitudes of both adhesive and cohesive strength exhibited similar velocity and concentration dependencies, suggesting that viscous dissipation of energy within mucus during cough determines the efficiency of cough clearance of diseased, hyperconcentrated, mucus. Calculations of airflow-induced shear forces on airway mucus related to mucus concentration predicted substantially reduced cough clearance in small versus large airways. Studies designed to improve cough clearance in subjects with mucoobstructive diseases identified reductions of mucus concentration and viscous dissipation as key therapeutic strategies.
Project description:Airway sensory nerves involved in the cough reflex are activated by adenosine triphosphate (ATP) agonism of P2X purinoceptor 3 (P2X3) receptors. Transient receptor potential vanilloid 4 (TRPV4) channel activation causes ATP release from airway cells, and it is hypothesised that a TRPV4-ATP-P2X3 axis contributes to chronic cough. An adaptive study was run to determine if TRPV4 inhibition, using the selective TRPV4 channel blocker GSK2798745, was effective in reducing cough. A two-period randomised, double blinded, placebo-controlled crossover study was designed with interim analyses for futility and sample size adjustment. Refractory chronic cough patients received either GSK2798745 or placebo once daily for 7 days with a washout between treatments. Pharmacokinetic samples were collected for analysis of GSK2798745 at end of study. The primary end-point was total cough counts assessed objectively during day-time hours (10 h) following 7 days of dosing. Interim analysis was performed after 12 participants completed both treatment periods. This showed a 32% increase in cough counts on Day 7 for GSK2798745 compared to placebo; the pre-defined negative criteria for the study were met and the study was stopped. At this point 17 participants had been enrolled (mean 61 years; 88% female), and 15 had completed the study. Final study results for posterior median cough counts showed a 34% (90% credible interval: -3%, +85%) numerical increase for GSK2798745 compared to placebo. There was no evidence of an anti-tussive effect of GSK2798745. The study design allowed the decision on lack of efficacy to be made with minimal participant exposure to the investigational drug.
Project description:Mucociliary clearance (MCC) is the key defense mechanism in the upper airways, as the removal of debris-laden mucus in the sinuses completely depends on MCC. So far, how the nasal MCC is regulated remains unknown. Recently, mice deficient in genes encoding the components of MCC apparatus have been generated, which will allow investigators to conduct more in-depth nasal MCC studies. However, the methodology necessary to comprehensively evaluate the nasal MCC in this species is not well established. We therefore developed a novel method to measure nasal MCC in live mice using pinhole gamma camera. Insoluble radiolabeled particles were delivered into the noses of lightly anesthetized mice. The nasal clearance of these particles was measured continuously in a real-time manner. The effect of three different anesthetics-avertin, pentobarbital, and isoflurane-on nasal MCC was also determined. In mice anesthetized by 1.1% isoflurane, radiolabeled particles were immediately moved into the oropharynx, which was significantly accelerated by the treatment of hypertonic but not isotonic saline. According to the clearance rate, the mouse nasal MCC presented two distinct phases: a rapid phase and a slow phase. In addition, we found that isoflurane had a very small inhibitory effect on nasal MCC vs. both avertin and pentobarbital. This was further supported by its dose response. Collectively, we have developed a noninvasive method to monitor the real-time nasal MCC in live mice under physiological conditions. It provides more comprehensive evaluation on nasal MCC rather than assessing a single component of the MCC apparatus in isolation.
Project description:BackgroundThe purpose of this study was to determine feasibility of treating refractory chronic cough (RCC) with progressive doses of capsaicin paired with cough suppression.MethodsIn this sham-controlled, parallel RCT, 14 adults with RCC were randomly assigned to either behavioral cough suppression therapy (BCST) plus 6 treatment sessions involving exposure to nebulized capsaicin in progressively larger concentrations while actively suppressing cough (n = 8), or BCST plus 6 sessions of exposure to a single subthreshold dose of capsaicin (sham; n = 6). The Leicester Cough Questionnaire (LCQ) was the primary outcome measure. Urge-to-cough (UTC) testing, measuring both UTC and cough frequency, served as secondary outcome measures. Data was analyzed with mixed effects linear regression and follow-up contrasts.ResultsResults on all measures favored the treatment group; however, there was only strong evidence of a difference in treatment effect on cough frequency during UTC testing. Mean change in LCQ at 3-weeks post treatment was 2.95 and 1.75 (p = .23), in the treatment and sham groups, respectively. Cough frequency during UTC testing reduced by 97% and 56% (p < .0001) at three weeks post, respectively. Within-group comparisons revealed strong evidence of change in the treatment group (p < .001) and moderate evidence of a change in the sham group (p = .08) in LCQ.ConclusionsConclusions from this study are limited due to the very small sample size; however, the study provides feasibility and proof-of-concept evidence to support further investigation of treating RCC with repeated exposure to nebulized capsaicin paired with BCST.
Project description:Radioembolization is increasingly used as a bridge to resection (i.e., radiation lobectomy). It combines ipsilateral tumor control with the induction of contralateral hypertrophy to facilitate lobar resection. The aim of this pilot study was to investigate the complementary value of hepatobiliary scintigraphy (HBS) before and after radioembolization in the assessment of the future remnant liver. Methods: Consecutive patients with liver tumors who underwent HBS before and after 90Y radioembolization were included. Regional (treated/nontreated) and whole liver function and volume were determined on HBS and CT. Changes in regional liver function and volume were correlated with the functional liver absorbed doses, determined on 90Y PET/CT. In addition, the correlation between liver volume and function change was evaluated. Results: Thirteen patients (10 hepatocellular carcinoma, 3 metastatic colorectal carcinoma) were included. Liver function of the treated part declined after radioembolization (HBS-pre, 4.0%/min/m2; HBS-post, 1.9%/min/m2; P = 0.001), whereas the function of the nontreated part increased (HBS-pre, 1.4%/min/m2; HBS-post, 2.8%/min/m2; P = 0.009). Likewise, treated volume decreased (pretreatment, 1,118.7 cm3; posttreatment, 870.7 cm3; P = 0.003), whereas the nontreated volume increased (pretreatment, 412.7 cm3; posttreatment, 577.6 cm3; P = 0.005). Bland-Altman analysis revealed a large bias (29%) between volume decrease and function decrease in the treated part and wide limits of agreement (-7.7%-65.6%). The bias between volume and function change was smaller (±6.0%) in the nontreated part of the liver, but limits of agreement were still wide (-117.9%-106.7%). Conclusion: Radioembolization induces regional changes in liver function that are accurately detected by HBS. Limits of agreement between function and volume changes were wide, showing large individual differences. This finding indicates that HBS may have a complementary role in the management of patients for radiation lobectomy.