Wall Area Percentage Research Articles

Anatomy and Properties of Japanese Hardwoods I. Variation of Fibre Dimensions and Tissue Proportions and their Relation to Basic Density

Variations of tissue proportions and fibre dimensions (fibre length, fibre cross sectional area, fibre wall thickness, fibre wall area, percentage of fibre wall area) of 50 Japanese hardwoods are compared. The fibre cross sectional area showed large variations as compared to fibre length. There is no significant correlation between fibre cross sectional area and fibre wall thickness.The multiple regression analysis showed that fibre wall thickness, percentage of fibre wall material and ray volume are the parameters most closely correlated with basic density.

Quantification of intimal cell masses and atherosclerotic lesions in coronary arteries of control and hyperlipidemic swine

In the current study of swine coronary arteries, we have attempted to quantify the coronary intimal cell masses (ICM) with regard to two aspects: (1) percentage of total arterial wall cells (intimal plus medial) that are in the intima, and (2) percentage of arterial wall area occupied by intima. We have studied 4 coronary sites: left main stem (LMS), proximal right (RCA), proximal left circumflex (LCX), and proximal left anterial descending (LAD). In mash-fed (‘normal’) swine we carried out the study at 3 ages: 2, 5 and 12 months. In addition, we have carried out a similar study in swine fed hyperlipidemic (HL) diets for 3 or ∼ 10 months starting at 2 months of age. In the control swine we found approximately 6% of the arterial wall occupied by intima at 2 months of age with no significant increases by 12 months. There were no consistent significant differences among the 4 coronary artery sites with regard to percentage of wall occupied by intima. When the HL diet was fed, there were significant increases in the percentage of the arterial wall occupied by intima (now atherosclerotic lesion) by 3 months on diet and much larger increases by 10 months (up to 87% of wall occupied by intimal lesion) with extensive regions of lipid-rich, calcific, necrotic debris. After 3 months on HL diet the RCA lesions occupied significantly greater percentages of areas than the other 3 sites but this difference had disappeared by 10 months on the HL diet.

Serum uric acid concentrations in an urbanized South African Negro population.

Small airway dysfunction and remodeling are known to influence the disease control and progression in asthma. We investigated the small airway involvement in asthmatic patients by correlating data derived from computed tomography (CT) and pulmonary function test (PFT). The CT lung scans were acquired at full inspiration and expiration using a portable spirometer to control the respiratory manoeuvers. PFT was performed before and after bronchodilator test with salbutamol 400 mcg, measuring lung volumes and flows, airway resistance (Raw) and single-breath nitrogen washout (SBN₂W). Up to now, 25 patients with mild-to-moderate asthma were studied. Fifteen had a good control of the disease at the time of the study as reflected by an Asthma Control Test (ACT) score ≥ 20. The mean lumen area (LA), measured in the left lower lobe posterior-basal segmental bronchus (LB10), correlated directly with the forced expiratory volume in 1 sec (FEV1) (r=0.60, p=0.002) and inversely with Raw (r=-0.52, p=0.011). The wall area percent (WA%) in the LB10 correlated inversely with FEV1 (r=-0.55, p=0.004)and directly with Raw (r=0.50, p=0.014). Air trapping, expressed as expiratory Voxel Index -856 HU (%), correlated inversely with FEV1 (r=-0.82, p<0.0001) and directly with both residual volume (RV)(r=0.72, p<0.0001) and the change in N₂ concentration in phase 3 of the SBN₂W test (r=0.67, p=0.001). A trend toward a significant increase in air trapping was found in the 10 patients with a poor control of the disease in comparison with the 15 patients in good control (p=0.083). These preliminary data show that both CT and PFT including Raw and SBN₂W provide useful information for the study of the small airways in asthma.