No abstract is provided for this article.
No abstract is provided for this article.
No abstract is provided for this article.
No abstract is provided for this article.
No abstract is provided for this article.
COPD is a chronic inflammatory lung disease associated with an increased pro-inflammatory macrophage (mφ) response whereby cells produce increased pro-inflammatory mediators CXCL8 and TNFα and decreased anti-inflammatory mediator IL-10. A monocyte-derived macrophage (MDM) model was used to study the effect of adherence and fetal calf serum (FCS) on mφ phenotype in non-smokers (NS n=3), smokers (S n=3) and COPD patients (COPD n=3). Monocytes were isolated and cultured for 12d in either adherent or non-adherent plates in the presence or absence of FCS and addition of either GM-CSF (G-mφ, M1) or M-CSF (M-mφ, M2). MDM were stimulated for 24h with either LPS or IL-4 and levels of CXCL8, TNFα and IL-10 measured by ELISA. Baseline cytokine production was minimal and did not differ between groups. G-mφ from COPD patients stimulated with LPS produced significantly more TNFα and CXCL8 compared to NS and S (Table 1). This persisted when G-mφ were cultured without serum or adherence. Lower levels of cytokines were released by M-mφ, although COPD MDM remained pro-inflammatory. M-mφ from S and COPD patients stimulated with IL-4 released less IL-10 than cells from NS (Table 2). This effect was lost in FCS-free media. COPD MDM consistently produce more pro-inflammatory cytokines and less IL-10 regardless of culture condition. FCS may be priming MDM to produce more cytokines when stimulated ex-vivo . These data suggest that circulating monocytes are primed in patients with COPD to generate a pro-inflammatory mφ regardless of environment.
Coronary artery stents have changed the face of interventional cardiology since their introduction in 1986. The commercial release of drug‐eluting stents in 2002 promised to abolish in‐stent restenosis as the predominant clinical limitation following stent implantation. Concerns raised about increased risks of adverse events with drug‐eluting stents now appear unfounded but have heralded a new era of research, where only hard clinical end‐points in sufficiently large numbers of patients are considered adequate. In this review, we highlight some of the potential future directions of drug‐eluting stents including specialized stent platforms (including dedicated bifurcation stents), fully degradable stents, and the potential use of stents to prevent cardiac events.
The lateral stability of imperfect discretely braced steel beams is analyzed using Rayleigh-Ritz approximations for the lateral deflection and the angle of twist. Initially, it is assumed that these degrees of freedom can be represented by functions comprising only single harmonics; this is then compared with the more accurate representation of the displacement functions by full Fourier series. It is confirmed by linear eigenvalue analysis that the beam can realistically buckle into two separate classes of modes: a finite number of node-displacing modes, equal to the number of restraints provided, and an infinite number of single harmonic buckling modes, where the restraint nodes remain undeflected. Closed-form analytical relations are derived for the elastic critical moment of the beam, the forces induced in the restraints, and the minimum stiffness required to enforce the first internodal buckling mode. The position of the restraint above or below the shear center is shown to influence the overall buckling behavior of the beam. The analytical results for the critical moment of the beam are validated by the finite-element program LTBeam, whereas the results for the deflected shape of the beam are validated by the numerical continuation software AUTO-07p, with very close agreement between the analytical and the numerical results.