Spontaneous pneumomediastinum (SPM) is a rare disorder most often affecting young males which is generally self-limiting. Despite the benign prognosis with few complications and little morbidity, it frequently confuses clinicians in primary settings, who may have difficulty differentiating SPM from other serious organ ruptures, especially oesophageal rupture (the so-called Boerhaave syndrome), which may lead to mediastinitis and may be fatal, even with appropriate interventions. An overview of adult SPM is provided, reviewing 17 studies (414 patients), including our clinical experience, and finally an algorithm for diagnosis and management of SPM is proposed, based on the characteristics of SPM.

SPM is a self-limiting disease with mild inflammatory signs. For patients suspicious of SPM, shortened hospitalization for about 2 days with observation alone may be feasible, if their symptoms improve gradually. Otherwise, less invasive procedures, such as esophagram, should be performed immediately. Long-term follow-up is usually unnecessary. We propose a new algorithm for management of SPM based on clinical experience.

BackgroundOzone is a major secondary air pollutant often reaching high concentrations in urban areas under strong daylight, high temperature and stagnant high-pressure systems. Ozone in the troposphere is a pollutant that is harmful to the plant.Principal FindingsBy exposing cells to a strong pulse of ozonized air, an acute cell death was observed in suspension cells of Arabidopsis thaliana used as a model. We demonstrated that O3 treatment induced the activation of a plasma membrane anion channel that is an early prerequisite of O3-induced cell death in A. thaliana. Our data further suggest interplay of anion channel activation with well known plant responses to O3, Ca2+ influx and NADPH-oxidase generated reactive oxygen species (ROS) in mediating the oxidative cell death. This interplay might be fuelled by several mechanisms in addition to the direct ROS generation by O3; namely, H2O2 generation by salicylic and abscisic acids. Anion channel activation was also shown to promote the accumulation of transcripts encoding vacuolar processing enzymes, a family of proteases previously reported to contribute to the disruption of vacuole integrity observed during programmed cell death.SignificanceCollectively, our data indicate that anion efflux is an early key component of morphological and biochemical events leading to O3-induced programmed cell death. Because ion channels and more specifically anion channels assume a crucial position in cells, an understanding about the underlying role(s) for ion channels in the signalling pathway leading to programmed cell death is a subject that warrants future investigation.

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UIP has a characteristic appearance that usually facilitates distinction from other types of chronic IIPs at thin-section CT. The most useful finding when differentiating UIP from NSIP was the extent of honeycombing.