Background: A special hydroxypropylmethylcellulose powder (Nasaleze®) has been used for the alleviation of nasal symptoms of allergic rhinitis since 1994. The efficacy of the product has been recently proven but the mechanism of action was still largely unknown. The aim of the study was to investigate the hypothesis that the gel formed after moisture absorption in the nose might act as mechanical barrier that prevents allergen diffusion towards the nasal epithelium. Methods: The diffusion of Der p 1 through HPMC and agar gels was measured in vitro after 15, 30, 60, 180 and 360 minutes using ELISA. Agar blocks were used to simulate the nasal mucosa. Control samples without gel layer were obtained. Results: The control samples with no applied gel barrier absorbed 72.2 % of the Der p 1 solution after 15 minutes and 100 % after 60 minutes. In comparison, the HPMC and agar gel layers both significantly delayed Der p 1 diffusion. After 15 minutes 0.76 % had diffused through the HPMC gel layer compared to 28.1 % which diffused through the agar layer. After 360 minutes, 14.1 % of the baseline Der p 1 crossed the HPMC gel layer while 100 % had diffused through the agar layer. Conclusions: HPMC gel significantly reduces Der p 1 diffusion in vitro compared to no barrier and an agar gel layer. This is likely to be due to the small mesh size of the polymer network of HPMC and could have important implications for a preventative treatment of allergic rhinitis.

BackgroundMulti-agency case management is being introduced by ambulance services and their partners in the UK to try to identify and address the needs of those who call 999 ambulance services frequently. However, there is a lack of evidence about what works well in this setting and how. Based on current nationally agreed definitions, calling frequently is defined as 5 or more times in a month, or 12 or more times in a three-month period. The STRETCHED study (STRategies to manage Emergency ambulance Telephone Callers with sustained High needs – an Evaluation using linked Data) study seeks to evaluate clinical and cost-effectiveness, safety, and efficiency of case management for people who frequently call the emergency ambulance service.We developed a logic model to describe key components, mechanisms of change and expected impacts of cross-sectoral case management approaches to the management of people who call 999 frequently.MethodWe conducted a stakeholder event with 37 people from Wales, England and Northern Ireland including patient representatives and professional staff involved in commissioning, planning and delivering case management for people who call 999 services frequently. The aggregated responses from the participants was used as the basis for developing a logic model.ResultsComponents: dedicated staff time for case management, availability and knowledge of relevant services for referral, multidisciplinary collaboration, organisational support, and clear information sharing protocolsMechanisms: provision of space for a clear understanding of reasons for calling, tailoring of multi–sectoral management to individual needs, offering therapeutic support and assistance in development of self–efficacyImpacts: improvement in access to appropriate and timely care, increase in efficiency and accessibility of the healthcare system, reduction in emergency calls, costs and mortalityConclusionCase management is a developing area of provision in prehospital emergency care for people who call ambulance services frequently. Our logic model provides a firm foundation for evaluation to build the urgently needed evidence base for case management of people who call ambulance services frequently.