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Chronic cough is common, and in many cases unexplained or refractory to otherwise effective treatment of associated medical conditions. Cough hypersensitivity has developed as a paradigm that helps to explain clinical and research observations that frequently point towards chronic cough as a neuropathic disorder. Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a recently described neurological condition whose clinical features include gait ataxia, unsteadiness, peripheral neuropathy, and autonomic dysfunction. Chronic cough is also a common feature of the syndrome, with features of hypersensitivity, often preceding core neurological symptoms by up to 30 years or more. The genetic basis in a majority of cases of CANVAS appears to be biallelic variable repeat intron expansion sequences within RFC1, a gene normally involved in the regulation of DNA replication and repair. The same polymorphism has now been identified at an increased frequency in patients with unexplained or refractory chronic cough in the absence of defining clinical features of CANVAS. This review expands on these points, aiming to increase the awareness of CANVAS amongst clinicians and researchers working with chronic cough. We discuss the implications of a link between RFC1 disease and cough. Improved understanding of CANVAS may lead to an enhanced grasp of the pathophysiology of chronic cough, and new approaches to antitussive treatments. [ABSTRACT FROM AUTHOR]

The transmission of tuberculosis is complex. Necessary factors include a source case with respiratory disease that has developed sufficiently for Mycobacterium tuberculosis to be present in the airways. Viable bacilli must then be released as an aerosol via the respiratory tract of the source case. This is presumed to occur predominantly by coughing but may also happen by other means. Airborne bacilli must be capable of surviving in the external environment before inhalation into a new potential host-steps influenced by ambient conditions and crowding and by M. tuberculosis itself. Innate and adaptive host defenses will then influence whether new infection results; a process that is difficult to study owing to a paucity of animal models and an inability to measure infection directly. This review offers an overview of these steps and highlights the many gaps in knowledge that remain. [ABSTRACT FROM AUTHOR]

Cough is a predominant feature of respiratory infection and, in tuberculosis, is of prime importance for transmitting infection. Tuberculosis is transmitted by the air, yet the process by which bacilli are aerosolized has received little attention. Features of cough may account for differences in transmission rates from source cases of pulmonary disease. We review the literature on the mechanisms and characteristics of cough in tuberculosis in the context of the dissemination of infection. Coughing is probably more important than other respiratory maneuvers, and characteristics of mucus may have an important role but data are scarce. Direct mechanisms of cough in tuberculosis are unknown, as are temporal and other patterns that correlate with the release of viable airborne bacilli. Other than antituberculous chemotherapy and masks, there are few methods of modulating cough in tuberculosis. This is an increasingly important area for research. [ABSTRACT FROM AUTHOR]

A letter to editor is presented in response to the article "The effectiveness of BCG vaccination in preventing Mycobacterium tuberculosis infection and disease in Greenland" by S. W. Michelsen, B. Soborg and colleagues in the 2014 issue.

A letter to the editor is presented in response to the article "The intensity of voluntary, induced and spontaneous cough" by K. K. Lee and colleagues in the 2015 issue.

Background: Cough is predictive of exacerbations of chronic obstructive pulmonary disease (COPD). Little is known about cough reflex sensitivity during exacerbation of COPD and whether it is associated with exacerbation frequency. This pilot study aimed to investigate cough reflex sensitivity during and following recovery from exacerbation of COPD, and its association with the frequency of future exacerbations. In addition, the repeatability of cough reflex sensitivity in stable COPD was investigated. Methods: Twenty participants hospitalised with exacerbation of COPD underwent inhaled capsaicin challenge during exacerbation and after 6 weeks of recovery. The frequency of future exacerbations was monitored for 12 months. The repeatability of cough reflex sensitivity was assessed in separate participants with stable COPD, who underwent 2 capsaicin challenge tests, 6 weeks apart. Results: Cough reflex sensitivity was heightened during exacerbation of COPD. Geometric mean (SD) capsaicin concentration thresholds to elicit 5 coughs (C5) during exacerbation and after 6 weeks of recovery were 1.76 (3.73) vs. 8.09 (6.25) μmol L−1, respectively (p < 0.001). The change in C5 from exacerbation to 6-week recovery was associated with the frequency of future exacerbations (ρ = − 0.687, p = 0.003). C5 was highly repeatable over 6 weeks in stable COPD, and intraclass correlation coefficient was 0.85. Conclusion: Cough reflex sensitivity is heightened during exacerbation of COPD and reduces after recovery. The persistence of cough reflex hypersensitivity at recovery was associated with the frequency of future exacerbations. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Systemic manifestations of COPD," by Y. Nussbaumer-Oschsner and K. F. Rabe, in the January 2011 issue.

A letter to the editor is presented that discusses the awareness of drug allergies in hospital patients.

A letter to the editor is presented in response to a study on the efficacy of P2X3 receptor antagonist in treating refractory chronic cough, which appeared in the March 28, 2015 issue.

Discusses the economics of genetics from a health commissioning point of view. Dynamics of clinical genetics; Factors which led to the acceptance of the inherited nature of several diseases; Impact of DNA technology on patients.

The article focuses on the randomized phase 2a trial of the drug linezolid carried out in South Korea where 41 patients were recruited with sputum culturepositive pulmonary extensively drug-resistant tuberculosis.