One Month Dosing of Atomoxetine plus Oxybutynin in Obstructive Sleep Apnea: A Randomized, Placebo-controlled Trial.

Rationale: The combination of noradrenergic and antimuscarinic agents has recently been shown to improve upper-airway function and reduce obstructive sleep apnea (OSA) severity in short-term (⩽1 wk) proof-of-concept studies. Objectives: To determine the safety, tolerability, and potential efficacy of longer term use of different doses of the noradrenergic agent atomoxetine combined with the antimuscarinic oxybutynin (ato-oxy). Methods: Thirty-nine people with predominantly severe OSA received 80/5 mg ato-oxy, 40/5 mg ato-oxy, 40/2.5 mg ato-oxy, or placebo nightly for 30 days in a double-blind, randomized, parallel design. Participants completed three in-laboratory sleep studies (baseline, Night 1, and Night 30) to assess efficacy. Vital signs and objective measures of alertness and memory were assessed. In men, potential effects on prostate function were assessed using the International Prostate Symptom Score at baseline and Night 30. Potential adverse events were assessed during in-laboratory visits and via weekly phone calls. Results: Side effects were generally mild and consistent with known side-effect profiles of each individual drug (i.e., dose-dependent increases in dry mouth with oxybutynin). Heart rate increased by Night 30 in two active drug arms (mean ± standard deviation 8 ± 10 beats/min [P = 0.01] with 80/5 mg and 9 ± 14 beats/min [P = 0.02] with 40/2.5 mg vs. placebo). No clinically relevant changes in blood pressure, International Prostate Symptom Score, and measures of alertness and memory were observed between conditions. Apnea-hypopnea index (AHI) with 4% oxygen desaturation and hypoxic burden decreased by ∼50% with 80/5 mg ato-oxy from baseline but not versus placebo (e.g., AHI with 3% oxygen desaturation and AHI with 4% oxygen desaturation difference at Night 30 was -8.2 [95% confidence interval, -22.5 to 6.2] and -8.5 [95% confidence interval, -18.3 to 1.3] events/h, respectively). Conclusions: One month of nightly noradrenergic and antimuscarinic combination therapy was generally well tolerated, with a side-effect profile consistent with each agent alone, and was associated with an ∼50% reduction from baseline in a key OSA severity metric, the hypoxic burden with the highest dose combination. These findings highlight the potential to target noradrenergic and antimuscarinic mechanisms for OSA pharmacotherapy development. Clinical trial registered with www.anzctr.org.au (ACTRN 12619001153101).

Contemporary Concise Review 2020: Sleep.

Obstructive sleep apnoea (OSA) now affects one-seventh of the world's population. Treatment of even mild OSA can improve daytime sleepiness and quality of life. Recent modifications to uvulopalatopharyngoplasty may make it a more widely applicable treatment option in selected patients with OSA. Diet and exercise have effects on sleep apnoea severity independent of weight loss. Insomnia has become increasingly common during the coronavirus disease 2019 (COVID-19) pandemic.

Timing it right: the challenge of recipient selection for lung transplantation.

Selection criteria for the referral and potential listing of patients for lung transplantation (LTx) have changed considerably over the last three decades but one key maxim prevails, the ultimate focus is to increase longevity and quality of life by careful utilization of a rare and precious resource, the donor organs. In this article, we review how the changes have developed and the outcomes of those changes, highlighting the impact of the lung allocation score (LAS) system. Major diseases, including interstitial lung disease (ILD), chronic obstructive pulmonary disease and pulmonary hypertension are considered in detail as well as the concept of retransplantation where appropriate. Results from bridging to LTx using extracorporeal membrane oxygenation (ECMO) are discussed and other potential contraindications evaluated such as advanced age, frailty and resistant infections. Given the multiplicity of risk factors it is a credit to those working in the field that such excellent and improving results are obtained with an ongoing dedication to achieving best practice.

Mathematical Modelling of Auxin Transport in Plant Tissues: Flux Meets Signalling and Growth.

Plant hormone auxin has critical roles in plant growth, dependent on its heterogeneous distribution in plant tissues. Exactly how auxin transport and developmental processes such as growth coordinate to achieve the precise patterns of auxin observed experimentally is not well understood. Here we use mathematical modelling to examine the interplay between auxin dynamics and growth and their contribution to formation of patterns in auxin distribution in plant tissues. Mathematical models describing the auxin-related signalling pathway, PIN and AUX1 dynamics, auxin transport, and cell growth in plant tissues are derived. A key assumption of our models is the regulation of PIN proteins by the auxin-responsive ARF-Aux/IAA signalling pathway, with upregulation of PIN biosynthesis by ARFs. Models are analysed and solved numerically to examine the long-time behaviour and auxin distribution. Changes in auxin-related signalling processes are shown to be able to trigger transition between passage- and spot-type patterns in auxin distribution. The model was also shown to be able to generate isolated cells with oscillatory dynamics in levels of components of the auxin signalling pathway which could explain oscillations in levels of ARF targets that have been observed experimentally. Cell growth was shown to have influence on PIN polarisation and determination of auxin distribution patterns. Numerical simulation results indicate that auxin-related signalling processes can explain the different patterns in auxin distributions observed in plant tissues, whereas the interplay between auxin transport and growth can explain the 'reverse-fountain' pattern in auxin distribution observed at plant root tips.

Antibiotic instillation for a chronic lung abscess.

INTRODUCTION: Antibiotic treatment of lung abscesses fails in 10-20% of cases and require surgery, however, some are unsuitable for resection. Alternative options carry significant morbidity. CASE REPORT: A 47 year old man with inoperable non-small cell lung cancer developed a lung abscess following definitive radiotherapy. Initial antibiotic therapy was successful, however four years later his symptoms recurred. Despite multiple courses his symptoms recurred despite long-term antibiotics. Immediately following a diagnostic aspiration, ceftriaxone and metronidazole were instilled into the abscess with subsequent clinical and radiological resolution. DISCUSSION: Lung abscesses are an uncommon complication of radiotherapy. Antibiotic therapy can fail for a number of reasons. Although instillation of antibiotics has not been described in the management of lung abscesses, the direct application of antifungals for aspergillomas is well documented and case series report success in other abscess sites. CONCLUSION: Direct antibiotic instillation following lung abscess aspiration adds minimal risk and is potentially curative.

Mathematical modelling and analysis of the brassinosteroid and gibberellin signalling pathways and their interactions.

The plant hormones brassinosteroid (BR) and gibberellin (GA) have important roles in a wide range of processes involved in plant growth and development. In this paper we derive and analyse new mathematical models for the BR signalling pathway and for the crosstalk between the BR and GA signalling pathways. To analyse the effects of spatial heterogeneity of the signalling processes, along with spatially-homogeneous ODE models we derive coupled PDE-ODE systems modelling the temporal and spatial dynamics of molecules involved in the signalling pathways. The values of the parameters in the model for the BR signalling pathway are determined using experimental data on the gene expression of BR biosynthetic enzymes. The stability of steady state solutions of our mathematical model, shown for a wide range of parameters, can be related to the BR homeostasis which is essential for proper function of plant cells. Solutions of the mathematical model for the BR signalling pathway can exhibit oscillatory behaviour only for relatively large values of parameters associated with transcription factor brassinazole-resistant1's (BZR) phosphorylation state, suggesting that this process may be important in governing the stability of signalling processes. Comparison between ODE and PDE-ODE models demonstrates distinct spatial distribution in the level of BR in the cell cytoplasm, however the spatial heterogeneity has significant effect on the dynamics of the averaged solutions only in the case when we have oscillations in solutions for at least one of the models, i.e. for possibly biologically not relevant parameter values. Our results for the crosstalk model suggest that the interaction between transcription factors BZR and DELLA exerts more influence on the dynamics of the signalling pathways than BZR-mediated biosynthesis of GA, suggesting that the interaction between transcription factors may constitute the principal mechanism of the crosstalk between the BR and GA signalling pathways. In general, perturbations in the GA signalling pathway have larger effects on the dynamics of components of the BR signalling pathway than perturbations in the BR signalling pathway on the dynamics of the GA pathway. The perturbation in the crosstalk mechanism also has a larger effect on the dynamics of the BR pathway than of the GA pathway. Large changes in the dynamics of the GA signalling processes can be observed only in the case where there are disturbances in both the BR signalling pathway and the crosstalk mechanism. Those results highlight the robustness of the GA signalling pathway.

Hereditary inclusion body myopathy: single patient response to intravenous dosing of GNE gene lipoplex.

Hereditary inclusion body myopathy (HIBM) is an autosomal recessive adult-onset myopathy due to mutations in the GNE (UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase) gene. Affected patients have no therapeutic options. We have previously demonstrated in preclinical testing the ability to safely correct GNE gene function through liposomal delivery of the wild-type GNE gene. Results were verified in a single patient treated by intravenous infusion of GNE gene lipoplex. A single patient (patient 001) with severe HIBM treated with a compassionate investigational new drug received seven doses of GNE gene lipoplex via intravenous infusion at the following doses: 0.4, 0.4, 1.0, 4.0, 5.0, 6.0, and 7.0 mg of DNA. GNE transgene expression, downstream induction of sialic acid, safety, and muscle function were evaluated. Transient low-grade fever, myalgia, tachycardia, transaminase elevation, hyponatremia, and hypotension were observed after infusion of each dose of GNE gene lipoplex. Quadriceps muscle expression of the delivered GNE, plasmid, and RNA was observed 24 hr after the 5.0-mg dose and at significantly greater levels 72 hr after the 7.0-mg infusion in comparison with expression in quadriceps muscle immediately before infusion. Sialic acid-related proteins were increased and stabilization in the decline of muscle strength was observed. We conclude that clinical safety and activity have been demonstrated with intravenous infusion of GNE gene lipoplex. Further assessment will involve a phase I trial of intravenous administration of GNE gene lipoplex in individuals with less advanced HIBM with more muscle function.

Wernicke's encephalopathy after gastric bypass that masqueraded as acute psychosis: a case report.

Wernicke's encephalopathy was originally described more than a decade ago. It has been reported after many causes of malnutrition. This case presents a patient with thiamine deficiency after gastric bypass, although unusual in itself, further complicating the case was the initial diagnosis of acute psychosis that was scheduled for electroconvulsive therapy. After recognition and intervention, the patient was successfully treated with thiamine replacement and parenteral nutrition.