Ambulatory oxygen in fibrotic lung disease (AmbOx): study protocol for a randomised controlled trial.

BACKGROUND: Fibrotic interstitial lung diseases (ILDs) are chronic and often progressive conditions resulting in substantial morbidity and mortality. Shortness of breath, a symptom often linked to oxygen desaturation on exertion, is tightly linked to worsening quality of life in these patients. Although ambulatory oxygen is used empirically in their treatment, there are no ILD-specific guidelines on its use. To our knowledge, no studies are available on the effects of ambulatory oxygen on day-to-day life in patients with ILD. METHODS/DESIGN: Ambulatory oxygen in fibrotic lung disease (AmbOx) is a multicentre, randomised controlled crossover trial (RCT) funded by the Research for Patient Benefit Programme of the National Institute for Health Research. The trial will compare ambulatory oxygen used during daily activities with no ambulatory oxygen in patients with fibrotic lung disease whose oxygen saturation (SaO2) is ≥94% at rest, but drops to ≤88% on a 6-min Walk Test. The randomised controlled trial (RCT) will evaluate the effects on health status (measured by the King's Brief ILD Questionnaire: K-BILD) of ambulatory oxygen used at home, at an optimal flow rate determined by titration at screening visit, and administered for a 2-week period, compared to 2 weeks off oxygen. Key secondary outcomes will include breathlessness on activity scores, as measured by the University of California San Diego Shortness of Breath Questionnaire, global patient assessment of change scores, as well as quality of life scores (St George's Respiratory Questionnaire), anxiety and depression scores (Hospital Anxiety and Depression Scale), activity markers measured by SenseWear Armbands, pulse oximetry measurements, patient-reported daily activities, patient- and oxygen company-reported oxygen cylinder use. The study also includes a qualitative component and will explore in interviews patients' experiences of the use of a portable oxygen supply and trial participation in a subgroup of 20 patients and carers. DISCUSSION: This is the first RCT of the effects of ambulatory oxygen during daily life on health status and breathlessness in fibrotic lung disease. The results generated should provide the basis for setting up ILD-specific guidelines for the use of ambulatory oxygen. TRIAL REGISTRATION: National Clinical Trials Registry, identifier: NCT02286063 . Registered on 8 October 2014 (retrospectively registered).

Mutation of Celsr1 disrupts planar polarity of inner ear hair cells and causes severe neural tube defects in the mouse.

We identified two novel mouse mutants with abnormal head-shaking behavior and neural tube defects during the course of independent ENU mutagenesis experiments. The heterozygous and homozygous mutants exhibit defects in the orientation of sensory hair cells in the organ of Corti, indicating a defect in planar cell polarity. The homozygous mutants exhibit severe neural tube defects as a result of failure to initiate neural tube closure. We show that these mutants, spin cycle and crash, carry independent missense mutations within the coding region of Celsr1, encoding a large protocadherin molecule [1]. Celsr1 is one of three mammalian homologs of Drosophila flamingo/starry night, which is essential for the planar cell polarity pathway in Drosophila together with frizzled, dishevelled, prickle, strabismus/van gogh, and rhoA. The identification of mouse mutants of Celsr1 provides the first evidence for the function of the Celsr family in planar cell polarity in mammals and further supports the involvement of a planar cell polarity pathway in vertebrate neurulation.