The safety and efficacy of infliximab in moderate to severe chronic obstructive pulmonary disease.

Rationale: Chronic obstructive pulmonary disease (COPD) is a progressive, smoking-related, inflammatory lung disease in which tumor necrosis factor-alpha is overexpressed and has been suggested to play a pathogenic role.

Objectives: To determine if infliximab, an anti-TNF-alpha antibody, results in clinical benefit and has an acceptable safety profile in patients with moderate to severe COPD.

Methods: In a multicenter, randomized, double-blind, placebo-controlled, parallel-group, dose-finding study, subjects with moderate to severe COPD received infliximab (3 mg/kg [n = 78] or 5 mg/kg [n = 79]) or placebo (n = 77) at Weeks 0, 2, 6, 12, 18, and 24.

Cigarette smoke inhibits alveolar repair: a mechanism for the development of emphysema.

Classically, emphysema has been believed to develop when mediators of tissue injury exceed protective mechanisms within the lung. Evidence also supports the concept that tissue destruction represents a balance between tissue injury and tissue repair. In this context, cigarette smoke is directly toxic to cells within the lung and can impair the repair functions of fibroblasts, epithelial cells, and mesenchymal cells.

Challenges and opportunities for combination therapy in chronic obstructive pulmonary disease.

Advances in the understanding of chronic obstructive pulmonary disease have presented a number of novel therapeutic opportunities. More extensive use of drug combinations is likely, but the development of these therapies presents a number of challenges. In clinical trials, a combination must be tested not only against placebo but also against each of its components, and the false-positive error rate increases rapidly with multiple comparisons.

Antiinflammatory therapies other than corticosteroids.

Antiinflammatory therapy for chronic obstructive pulmonary disease (COPD) can be directed at several stages of the inflammatory process. Much attention has been focused on blocking the damaging effects of toxic mediators released by inflammatory cells, including antioxidants and antiproteases. An alternate strategy is to block the recruitment of inflammatory cells into the lung, such as by inhibiting the production of chemotactic factors driving inflammatory cell recruitment, the ability of inflammatory cells to respond to chemotactic factors, and the ability of inflammatory cells to migrate.

Thrombin induces collagen gel contraction partially through PAR1 activation and PKC-epsilon.

The ability of fibroblasts to contract three-dimensional collagen gels has been used as an in vitro model of the tissue contraction which characterises both normal repair and fibrosis. Among its actions, thrombin can activate the protease-activated receptor (PAR)1 and, thereby, stimulate inflammation and repair. The current study evaluated whether thrombin could stimulate fibroblast-mediated collagen gel contraction by activating PAR1 and whether its downstream signalling depends on protein kinase C (PKC)-epsilon.

TH2 Cytokine-enhanced and TGF-beta-enhanced vascular endothelial growth factor production by cultured human airway smooth muscle cells is attenuated by IFN-gamma and corticosteroids.

Background: T(H)2 and T(H)1 cytokines have opposite effects on many aspects of the inflammatory response.

Methods: This study was designed to determine if cytokines possibly present in asthma can modulate airway smooth muscle cell (ASMC) production of vascular endothelial growth factor (VEGF) and thus contribute to altered airway vascularity. ASMC were incubated for 24 hours with various concentrations of T(H)2 cytokines (IL-4, IL-5, IL-10, and IL-13); transforming growth factor (TGF)-beta1, TGF-beta2, or TGF-beta3; and IL-1beta or TNF-alpha with or without IFN-gamma.

Collaborative interactions between neutrophil elastase and metalloproteinases in extracellular matrix degradation in three-dimensional collagen gels.

Background: Extended culture of monocytes and fibroblasts in three-dimensional collagen gels leads to degradation of the gels (see linked study in this issue, "Fibroblasts and monocytes contract and degrade three-dimensional collagen gels in extended co-culture"). The current study, therefore, was designed to evaluate production of matrix-degrading metalloproteinases by these cells in co-culture and to determine if neutrophil elastase could collaborate in the activation of these enzymes. Since co-cultures produce prostaglandin E2 (PGE2), the role of PGE2 in this process was also evaluated.

Fibroblasts and monocyte macrophages contract and degrade three-dimensional collagen gels in extended co-culture.

Background: Inflammatory cells are believed to play a prominent role during tissue repair and remodeling. Since repair processes develop and mature over extended time frames, the present study was designed to evaluate the effect of monocytes and fibroblasts in prolonged culture in three-dimensional collagen gels.

Methods: Blood monocytes from healthy donors and human fetal lung fibroblasts were cast into type I collagen gels and maintained in floating cultures for three weeks.