Monitoring asthma in children.

The goal of asthma treatment is to obtain clinical control and reduce future risks to the patient. To reach this goal in children with asthma, ongoing monitoring is essential. While all components of asthma, such as symptoms, lung function, bronchial hyperresponsiveness and inflammation, may exist in various combinations in different individuals, to date there is limited evidence on how to integrate these for optimal monitoring of children with asthma. The aims of this ERS Task Force were to describe the current practise and give an overview of the best available evidence on how to monitor children with asthma. 22 clinical and research experts reviewed the literature. A modified Delphi method and four Task Force meetings were used to reach a consensus. This statement summarises the literature on monitoring children with asthma. Available tools for monitoring children with asthma, such as clinical tools, lung function, bronchial responsiveness and inflammatory markers, are described as are the ways in which they may be used in children with asthma. Management-related issues, comorbidities and environmental factors are summarised. Despite considerable interest in monitoring asthma in children, for many aspects of monitoring asthma in children there is a substantial lack of evidence.

“Unconformity-Bounded” Stratigraphic Units in the South Polar Layered Deposits (Promethei Lingula, Mars)

We conducted a stratigraphic analysis of the South Polar Layered Deposits (SPLDs) in Promethei Lingula (PL, Mars) based on the identification of regional unconformities at visible and radar wavelengths. According to the terrestrial classification, this approach constrains the stratigraphy of the region and remedies the ambiguous interpretation of stratigraphy through marker layers, bypassing the problem related to the morphologic and radiometric appearance of the layers. Thus, the approach does not exclude diverse classifications, but complements them, whereas other discriminant elements are doubtful or difficult/impossible to be defined. Using this approach, we defined two stratigraphic units (or synthems: PL1 and PL2) in PL, which are morphologically different and divided by a regional unconformity (AuR1). This stratigraphic architecture implies that the geological history of PL has been conditioned by periodic changes in climate, which in turn are related to orbital variations of Mars.

Murine coronavirus ubiquitin-like domain is important for papain-like protease stability and viral pathogenesis

Ubiquitin-like domains (Ubls) now are recognized as common elements adjacent to viral and cellular proteases; however, their function is unclear. Structural studies of the papain-like protease (PLP) domains of coronaviruses (CoVs) revealed an adjacent Ubl domain in severe acute respiratory syndrome CoV, Middle East respiratory syndrome CoV, and the murine CoV, mouse hepatitis virus (MHV). Here, we tested the effect of altering the Ubl adjacent to PLP2 of MHV on enzyme activity, viral replication, and pathogenesis. Using deletion and substitution approaches, we identified sites within the Ubl domain, residues 785 to 787 of nonstructural protein 3, which negatively affect protease activity, and valine residues 785 and 787, which negatively affect deubiquitinating activity. Using reverse genetics, we engineered Ubl mutant viruses and found that AM2 (V787S) and AM3 (V785S) viruses replicate efficiently at 37°C but generate smaller plaques than wild-type (WT) virus, and AM2 is defective for replication at higher temperatures. To evaluate the effect of the mutation on protease activity, we purified WT and Ubl mutant PLP2 and found that the proteases exhibit similar specific activities at 25°C. However, the thermal stability of the Ubl mutant PLP2 was significantly reduced at 30°C, thereby reducing the total enzymatic activity. To determine if the destabilizing mutation affects viral pathogenesis, we infected C57BL/6 mice with WT or AM2 virus and found that the mutant virus is highly attenuated, yet it replicates sufficiently to elicit protective immunity. These studies revealed that modulating the Ubl domain adjacent to the PLP reduces protease stability and viral pathogenesis, revealing a novel approach to coronavirus attenuation. IMPORTANCE Introducing mutations into a protein or virus can have either direct or indirect effects on function. We asked if changes in the Ubl domain, a conserved domain adjacent to the coronavirus papain-like protease, altered the viral protease activity or affected viral replication or pathogenesis. Our studies using purified wild-type and Ubl mutant proteases revealed that mutations in the viral Ubl domain destabilize and inactivate the adjacent viral protease. Furthermore, we show that a CoV encoding the mutant Ubl domain is unable to replicate at high temperature or cause lethal disease in mice. Our results identify the coronavirus Ubl domain as a novel modulator of viral protease stability and reveal manipulating the Ubl domain as a new approach for attenuating coronavirus replication and pathogenesis.