Therapeutic role of terbutaline in a rat whole-lung lavage model

Preclinical safety and efficacy models for pulmonary drug delivery of antimicrobials with focus on in vitro models

New pharmaceutical formulations must be proven as safe and effective before entering clinical trials. Also in the context of pulmonary drug delivery, preclinical models allow testing of novel antimicrobials, reducing risks and costs during their development. Such models allow reducing the complexity of the human lung, but still need to reflect relevant (patho-) physiological features. This review focuses on preclinical pulmonary models, mainly in vitro models, to assess drug safety and efficacy of antimicrobials. Furthermore, approaches to investigate common infectious diseases of the respiratory tract, are emphasized. Pneumonia, tuberculosis and infections occurring due to cystic fibrosis are in focus of this review. We conclude that especially in vitro models offer the chance of an efficient and detailed analysis of new antimicrobials, but also draw attention to the advantages and limitations of such currently available models and critically discuss the necessary steps for their future development.

Adrenaline stimulates the proliferation and migration of mesenchymal stem cells towards the LPS-induced lung injury

Bone marrow-derived mesenchymal stem cells (BMSCs) could modulate inflammation in experimental lung injury. On the other hand, adrenergic receptor agonists could increase DNA synthesis of stem cells. Therefore, we investigated the therapeutic role of adrenaline-stimulated BMSCs on lipopolysaccharide (LPS)-induced lung injury. BMSCs were cultured with adrenergic receptor agonists or antagonists. Suspensions of lung cells or sliced lung tissue from animals with or without LPS-induced injury were co-cultured with BMSCs. LPS-stimulated alveolar macrophages were co-cultured with BMSCs (with adrenaline stimulation or not) in Transwell for 6 hrs. A preliminary animal experiment was conducted to validate the findings in ex vivo study. We found that adrenaline at 10 μM enhanced proliferation of BMSCs through both α- and β-adrenergic receptors. Adrenaline promoted the migration of BMSCs towards LPS-injured lung cells or lung tissue. Adrenaline-stimulated BMSCs decreased the inflammation of LPS-stimulated macrophages, probably through the expression and secretion of several paracrine factors. Adrenaline reduced the extent of injury in LPS-injured rats. Our data indicate that adrenaline-stimulated BMSCs might contribute to the prevention from acute lung injury through the activation of adrenergic receptors, promotion of proliferation and migration towards injured lung, and modulation of inflammation.

Pulmonary alveolar proteinosis: report of two cases in the West of Ireland with review of current literature

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare lung condition characterised by the accumulation of lipoproteinaceous surfactant material within alveolar airspaces resulting in clinical manifestations ranging from asymptomatic to severe respiratory failure. Three disease subtypes are recognised: autoimmune, secondary and congenital.

METHODS

We describe two presentations of PAP in the West of Ireland with a review of the current literature.

RESULTS

Autoimmune PAP, associated with the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies, accounts for >90 % of cases. Treatment with whole lung lavage is the current standard of care. Novel therapies targeting alveolar macrophages (recombinant GM-CSF therapy) and anti-GM-CSF antibodies (rituximab, plasmapharesis) are under investigation.

CONCLUSIONS

This is a summary of available literature outlining current clinical practice in the diagnosis, management, and treatment of PAP. PAP should be considered in the differential diagnosis of any patient with a restrictive pulmonary defect. Without high clinical suspicion, this diagnosis can easily be missed.