Biomedical subjects
Publications and source records attributed to Jack A Kastelik.
The Fourth International Cough Symposium took place in London between the 29th of June and 1st of July 2006. There were overall 22 posters presented during the meeting. These posters were divided into the following sections: methods of cough investigations, definitions of cough, receptor mechanisms, neural pathways, animal experiments and clinical aspects of cough. This review will focus on the discussions related to the posters.
Explore the source record for details and available documents.
TRPV1 is a modulator of noxious stimuli known to be important in the cough reflex. We have compared the expression of TRPV1 in normal human airways and those from patients with chronic cough and found that there is up regulation in airways smooth muscle in disease. This increased expression appears to be intracellular and we have therefore examined the role of intracellular rat and human TRPV1 activity was found using intracellular calcium signalling with human intracellular TRPV1 being located in a thapsigargin insensitive compartment. Increase in TRPV1 activity may have a role in the airway hypersensitivity seen in chronic cough.
Explore the source record for details and available documents.
Among patients attending specialist cough clinics there is an excess of females, but the reason for this sex difference is unknown. We tested the hypothesis that the sensitivity of the cough reflex is greater in female compared with male patients with chronic cough. Inhalation cough challenges with capsaicin and citric acid were performed in a large group of patients with chronic cough. The concentrations of tussive agent causing two (C2) and five (C5) coughs were calculated. Measurements of capsaicin cough reflex sensitivity (median [interquartile range]) were significantly lower for female patients compared with male patients (C2: 1.9 [0.5 to 5.5] versus 5.3 [2.2 to 11.5] micro M, p = 0.0026; C5: 8.6 [2.2 to 34.0] versus 51.2 [7.2 to > 100] micro M, p = 0.0007). Similarly for citric acid challenge, values were significantly lower for female compared with male patients (C2: 53.5 [17.3 to 145.4] versus 118.1 [41.4 to 381.7] mM, p = 0.0064; C5: 300.0 [97.1 to > 1,000] versus 830.4 [300.0 to > 1,000] mM, p = 0.032). There were significant correlations between capsaicin and citric acid C2 values (r(s) = 0.54, p < 0.0001) and C5 values (r(s) = 0.57, p < 0.0001). These findings indicate a sex difference in cough sensitivity in patients with chronic cough, as previously reported in healthy volunteers. This may explain the female preponderance in cough clinics.
Whilst nebulisers are commonly used in the treatment of cystic fibrosis (CF), nebulised aerosol lung deposition in individual patients is not routinely assessed in clinical practice. The present study was designed to evaluate whether a comparative measurement of aerosol lung deposition from nebulisers using a widely available scintigraphic method could be employed to assist the selection of the best system for individual patients. Lung deposition of the radiolabelled aerosol from the Pari LC Plus (Pari Medical Ltd) nebuliser and the HaloLite Adaptive Aerosol Delivery (AAD) system (Profile Therapeutics Ltd) was measured using planar scintigraphy in 10 healthy volunteers and 6 CF patients. The HaloLite AAD delivered on average 2.1 times (P=0.003) as much aerosol to the lungs compared with Pari LC Plus. Only two subjects had higher lung deposition from Pari LC Plus than HaloLite AAD system. There was marked inter-individual variation in the deposition pattern in CF patients. The aerosol deposition from HaloLite AAD had higher central distribution than that obtained with the Pari LC Plus. The overall intersubject variability of the delivered dose was 56% with Pari LC Plus and 24% with HaloLite AAD (P<0.05). The measurement of aerosol deposition from nebulisers can be performed using a simple and widely available methodology, and may improve nebuliser selection in CF patients.
STUDY OBJECTIVES: Gastroesophageal reflux (GER) is one of the most common causes of chronic cough, but the mechanisms of GER-related cough are not well-understood. We tested the hypothesis that gastric emptying is delayed in patients with GER-related chronic cough. DESIGN: We studied 12 patients (7 women; mean age, 53 years; age range, 37 to 68 years) with GER-related chronic cough and a control group of 27 asymptomatic healthy volunteers (16 women; mean age, 37 years; age range, 18 to 62 years). Gastric emptying scintigraphy was performed, and the time at which 50% of the radiolabeled material had left the stomach (T(1/2)) was calculated. RESULTS: There was no statistically significant difference in T(1/2) values between healthy volunteers and subjects with GER-related cough (99 +/- 26 min vs 86 +/- 20 min, respectively; difference between the means, 13 min [95% confidence interval, -4 to 30 min]; p = 0.13). CONCLUSIONS: Gastric emptying was not delayed in patients with GER-related chronic cough. The measurement of gastric emptying did not therefore provide further insights into the mechanisms of GER-related cough or clinically relevant information that would assist in patient management.