Publications

Assessment of the functional significance of coronary artery lesions during cardiac catheterization has recently become possible by calculating coronary flow reserve from both myocardial contrast appearance time and density in the resting and hyperemic states determined from digitized coronary cineangiograms. However, the interobserver and intraobserver variabilities, as well as the short-, medium-, and long-term variabilities of the coronary flow reserve measurements, have to be established before this technique becomes an acceptable means of assessing the immediate and long-term functional results of revascularization procedures such as percutaneous transluminal coronary angioplasty (PTCA). Variability was defined as the mean difference and standard deviation of the difference between duplicate determinations of coronary flow reserve. The intraobserver variability (mean difference +/- SD) in the measurement of coronary flow reserve was -0.01 +/- 0.07. Interobserver variability by two observers was +0.08 +/- 0.52. Short-term variability based on the analysis of two coronary cineangiograms taken 5 minutes apart was -0.02 +/- 0.26. Medium-term variability (coronary cineangiographies repeated 1-3 hours apart) was found to be -0.06 +/- 0.52. Long-term variability (coronary cineangiographies repeated 3-5 months apart) was 0.11 +/- 0.63. Having established the reproducibility of this radiographic method, we studied the prospective changes in coronary flow reserve in 25 patients undergoing PTCA for single vessel coronary artery disease. Coronary flow reserve measurements and quantitative coronary cineangiography were performed before, immediately after, and 3-5 months after PTCA. PTCA resulted in an immediate increase in coronary flow reserve from 1 +/- 0.3 to 2.3 +/- 0.6 with a concomitant increase in obstruction area from 0.9 +/- 0.3 to 3.3 +/- 0.7 mm2. Nine of the 25 patients developed restenosis defined as a diameter stenosis greater than 50% at follow-up. The other 16 patients had a coronary flow reserve of 3.3 +/- 0.6, which was measured 3-5 months after PTCA. Coronary flow reserve measurement from digitized coronary cineangiograms is a reproducible method for the assessment of the physiological importance of coronary artery obstructions. Short-, medium-, and long-term investigations of the functional results of interventions such as pharmacological therapy or revascularization can be performed reliably with this technique.

Abstract Current rhinometric and flow assessments measure nasal patency and are often poorly correlated with rhinitis symptoms. To evaluate magnetic resonance imaging (MRI) as a new method to measure inflammatory changes in nasal and sinus mucosa following nasal allergen challenge. A pilot study ( n = 6) determined the optimal technical settings for MRI to measure inflammatory change which were then adopted for the main study. This study was a single blind, placebo‐controlled, three‐way crossover trial in 14 subjects with seasonal allergic rhinitis. Effects of cetirizine, cetirizine and pseudoephedrine (Cet+PE), or placebo on total nasal symptom scores (TNSS), peak nasal inspiratory flow (PNIF), nasal nitric oxide (nNO), acoustic rhinometry, and MRI end points following nasal intranasal allergen challenge were measured. There were significant changes in all parameters after allergen challenge ( P < 0.01), except for nNO. MRI end points were less variable and more consistent than PNIF and acoustic rhinometry in detecting changes after allergen challenge. Total nasal airspace volume was the most sensitive and reproducible MRI measurement, with a mean reduction from −5.37 cm 3 (95%CI −7.35, −3.38; P < 0.001), which was maximal 60 min after allergen challenge. A change of one in TNSS corresponded to a change in MRI volume of −0.57 cm 3 . There was an improvement in all parameters (except nNO) in subjects taking Cet+PE compared with placebo, however this did not achieve significance probably because of the small study size (overall analysis P > 0.07; comparison of active versus placebo P > 0.09). MRI provides novel insights into the anatomical inflammatory changes post allergen challenge and provides a new method for assessment of nasal patency and objective measurement of inflammatory responses.

Embedded steel column bases are normally idealized as fixed boundary condition in the analysis of steel frameworks. In practice, the embedded column bases sometimes have embedded depth notably smaller than that recommended by the structural design codes. In such a case, the fixed boundary assumption may overestimate the stiffness of the bases to a large extent. In light of this, this paper proposes a theoretical model for the accurate prediction of the rotational stiffness of the shallow embedded steel column bases, with the combined effects of key influencing factors, including the axial load in the column, the shear deformation of the embedded column, the rotational constraint provided by the column end plate, and the stiffness contribution from the anchor bolts. To achieve this, the calculation of the rotational stiffness of the base plate is refined in this paper based on previous study, which can consider the contribution from the anchor bolts, and incorporated in the Winkler foundation beam model, giving the expression of the initial rotational stiffness of the embedded column base. The proposed model is validated by the experimental and finite element simulation results.

No abstract is provided for this article.

Coronary artery calcium score (CACS) is an established marker of coronary artery disease (CAD) and has been extensively used to stratify risk in asymptomatic individuals. However, the value of CACS in predicting plaque morphology in patients with advanced CAD is less established. The present analysis aims to assess the association between CACS and plaque characteristics detected by near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) imaging in patients with obstructive CAD.

Lower airway colonisation with species of potentially pathogenic bacteria (PPB) is associated with defective bacterial phagocytosis, in monocyte-derived macrophages (MDMs) and alveolar macrophages, from tobacco smoke-associated chronic obstructive pulmonary disease (S-COPD) subjects. In the developing world, COPD among nonsmokers is largely due to biomass smoke (BMS) exposure; however, little is known about PPB colonisation and its association with impaired innate immunity in these subjects.We investigated the PPB load (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Pseudomonas aeruginosa) in BMS-exposed COPD (BMS-COPD) subjects compared with S-COPD and spirometrically normal subjects. We also examined the association between PPB load and phagocytic activity of MDMs and lung function. Induced sputum and peripheral venous blood samples were collected from 18 healthy nonsmokers, 15 smokers without COPD, 16 BMS-exposed healthy subjects, 19 S-COPD subjects and 23 BMS-COPD subjects. PPB load in induced sputum and MDM phagocytic activity were determined using quantitative PCR and fluorimetry, respectively.Higher bacterial loads of S. pneumoniae, H. influenzae and P. aeruginosa were observed in BMS-COPD subjects. Increased PPB load in BMS-exposed subjects was significantly negatively associated with defective phagocytosis in MDMs and spirometric lung function indices (p<0.05).Increased PPB load in airways of BMS-COPD subjects is inversely associated with defective bacterial phagocytosis and lung function.

Prior studies have reported an association between elevated white blood cell count (WBCc) and worse clinical outcomes after coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). We assessed the prognostic impact of WBCc in patients undergoing revascularization for left main coronary artery disease (LMCAD).In Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization (EXCEL), 1905 patients with LMCAD and low or intermediate SYNTAX scores were randomized to PCI with everolimus-eluting stents versus CABG. The 1895 patients with baseline WBCc available were grouped in tertiles of WBCc (mean 5.6 ± 0.8, 7.5 ± 0.5, and 10.1 ± 1.6 × 109/L).Five-year rates of the primary endpoint (death, myocardial infarction or stroke) were similar across increasing WBCc tertiles (21.2, 18.9, and 21.6%; P = 0.46). Individual components of the primary endpoint, Bleeding Academic Research Consortium (BARC) 3-5 bleeding, stent thrombosis or graft occlusion and ischemia-driven revascularization were all similar across WBCc tertiles. By multivariable analysis, WBCc as a continuous variable was not an independent predictor of adverse events (hazard radio per 1 × 109/L: 1.02; 95% CI, 0.97-1.08; P = 0.43). Results were consistent in the PCI and CABG arms individually.There was no association between baseline WBCc and 30-day or 5-year clinical outcomes after PCI or CABG. The absence of a clear incremental increase in events with increasing WBCc in the current analysis indicates that WBCc should not routinely be used as a prognostic marker or to guide revascularization decisions in patients with LMCAD.