Phonation in a straw. Experimental in vivo measurement of subglottic pressure with EVA@ device

International audienceIntroduction: We used vocal reeducation techniques based on exercices with a straw for more than 20 years. It seems to allows a gentle vibration of the vocal cords as well as a progression of the cordal ad- duction force proportional to resistance due to the straw. Our aim is to study the intraoral and subglottic pressures (IOP and SGP) and the modalities of the glottic vibration during these exercices. Method: The subject is a male vocal professional, with no voice pathology. The subglottic pressure was recorded by a probe placed between the first and the second tracheal ring and the intraoral pressure by a probe placed in the mouth. The voice is produced after a short expiration time, to obtain a sufficient and stable air flow, controlled with the hand at the extremity of the straw. Eight models of straw with different calibre and length were tested. The data were collected with the EVA@device and analysed with the Phonedit software (Sq-Lab, Aix en Provence). Results: A pressure gradient exists between the SGP and the IOP, variing with the voice frequency, and close to the phonation pressure threshold. The pressures are bigger when the straw calibre is small, the straw long and the frequency high. The vocal cord contact is differed when the straw is long. Conclusion: The phonation exercices with the straw require an output airflow control and thus allows an optimal adaptation of the SGP and vocal coaptation without risk for the free border of the vocal cords

Challenges in applying the GRADE approach in public health guidelines and systematic reviews: a concept article from the GRADE Public Health Group

Objective: This paper explores the need for conceptual advances and practical guidance in the application of the GRADE approach within public health contexts. Study Design and Setting: We convened an expert workshop and conducted a scoping review to identify challenges experienced by GRADE users in public health contexts. We developed this concept paper through thematic analysis and an iterative process of consultation and discussion conducted with members electronically and at three GRADE Working Group meetings. Results: Five priority issues can pose challenges for public health guideline developers and systematic reviewers when applying GRADE: (1) incorporating the perspectives of diverse stakeholders; (2) selecting and prioritising health and ‘non-health’ outcomes; (3) interpreting outcomes and identifying a threshold for decision-making; (4) assessing certainty of evidence from diverse sources, including non-randomised studies; and (5) addressing implications for decision-makers, including concerns about conditional recommendations. We illustrate these challenges with examples from public health guidelines and systematic reviews, identifying gaps where conceptual advances may facilitate the consistent application or further development of the methodology, and provide solutions. Conclusion: The GRADE Public Health Group will respond to these challenges with solutions that are coherent with existing guidance and can be consistently implemented across public health decision-making contexts

Stem cell therapy for Alzheimer’s disease and related disorders: current status and future perspectives

Underlying cognitive declines in Alzheimer's disease (AD) are the result of neuron and neuronal process losses due to a wide range of factors. To date, all efforts to develop therapies that target specific AD-related pathways have failed in late-stage human trials. As a result, an emerging consensus in the field is that treatment of AD patients with currently available drug candidates might come too late, likely as a result of significant neuronal loss in the brain. In this regard, cell-replacement therapies, such as human embryonic stem cell- or induced pluripotent stem cell-derived neural cells, hold potential for treating AD patients. With the advent of stem cell technologies and the ability to transform these cells into different types of central nervous system neurons and glial cells, some success in stem cell therapy has been reported in animal models of AD. However, many more steps remain before stem cell therapies will be clinically feasible for AD and related disorders in humans. In this review, we will discuss current research advances in AD pathogenesis and stem cell technologies; additionally, the potential challenges and strategies for using cell-based therapies for AD and related disorders will be discussed