Fumihiro Mitsunobu

Effects of Perilla Seed Oil Supplementation on Leukotriene Generation by Leucocytes in Patients with Asthma Associated with Lipometabolism

Background: Dietary sources of α-linolenic acid, such as perilla seed oil, may have the capacity to inhibit the generation of leukotrienes (LTs) by leucocytes in patients with asthma, as has been reported with the consumption of other long-chain n-3 fatty acids. Methods: The factors affecting the suppression of leukotriene (LT) C4 generation by leucocytes were examined by comparing the clinical features of patients with asthma who had been given dietary perilla seed oil (n-3 fatty acids). Group A consisted of patients in whom the leucocyte generation of LTC4 was suppressed by dietary perilla seed oil. Group B consisted of those in whom LTC4 generation was not suppressed. Results: LTC4 generation by leucocytes decreased significantly in group A after 2 (p < 0.05) and 4 weeks (p < 0.05); conversely, it increased significantly in group B after 4 weeks (p < 0.05). The two study groups differed significantly in terms of LTC4 generation by leucocytes after 4 weeks of dietary supplementation (p < 0.05). Ventilatory parameters such as peak expiratory flow (PEF), forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) increased significantly after 4 weeks of dietary supplementation in group A (p < 0.05). Values of PEF, FVC, FEV1 and maximum expiratory flow at 25% of the forced vital capacity (v̇25) differed significantly between groups A and B prior to dietary supplementation. Serum levels of total cholesterol, low-density lipoprotein (LDL) cholesterol and phospholipid were significantly decreased by dietary supplementation in group A after 4 weeks. Serum levels of total cholesterol, triglyceride, high-density lipoprotein cholesterol, LDL cholesterol and phospholipid differed significantly between the two study groups prior to dietary supplementation. Serum levels of triglyceride and LDL cholesterol differed significantly between the two study groups after 4 weeks of dietary supplementation. Conclusions: Dietary supplementation with perilla seed oil in selected patients with asthma suppresses the generation of LTC4 and is associated with clinical features such as respiratory function and lipometabolism.

Low-Attenuation Areas of the Lungs on High-Resolution Computed Tomography in Asthma

To investigate the low-attenuation areas of the lungs (LAA) in asthma, we compared the mean lung density (MLD) and the LAA in 22 asthmatics (12 ex-smokers and 10 nonsmokers) and 13 patients with chronic obstructive pulmonary disease (COPD) by high-resolution computed tomography. The MLD and the relative area of the lung with attenuation values lower than −950 Hounsfield Units at full inspiration (inspiratory RA950) were significantly different in nonsmoking asthmatics compared to patients with COPD and asthmatics with a smoking history. The MLD and the RA950 correlated significantly with the FEV1 in all groups and with the DLCO in patients with COPD and asthmatics with a smoking history but not in nonsmoking asthmatics. We concluded that the LAA in asthmatics with a smoking history indicates the presence of emphysema, but in nonsmoking asthmatics it reflects hyperinflation and nonemphysematous expiratory airflow limitation rather than emphysematous lesions.

Oral Glucocorticoid-Induced Fall in Cortical Bone Volume and Density in Postmenopausal Asthmatic Patients

Abstract: Despite a deepening understanding of the influence of glucocorticoids (GC) on trabecular bone, little is known about GC-induced cortical bone loss. To elucidate the mechanism of GC-induced loss of cortical bone strength with particular reference to cortical bone loss, changes in cortical density, relative cortical volume, and the Strength Strain Index (SSI) based on biomechanical analyses of the geographic distribution of cortical bone material were measured. These parameters were compared, using peripheral quantitative computed tomography (pQCT), among the following age-matched groups: 68 postmenopausal asthmatic patients receiving high-dose oral GC in addition to inhaled GC (oral GC group), 68 postmenopausal asthmatic patients receiving only inhaled GC (inhaled GC group) and 69 postmenopausal controls without asthma or GC therapy (control group). Cortical bone mineral density (BMD) was measured, relative cortical volume was obtained by dividing the cortical area by the total bone area using pQCT (Stratec XCT960), and the Strength Strain Index (SSI) was calculated in the radius based on the density distribution around the axis. Spinal fracture was assessed on lateral radiographs. The number of vertebral fractures per patient correlated highly with cortical BMD, relative cortical volume and SSI values at the radius. The number of vertebral fractures per patient and the number of patients with fracture were similar between the control and inhaled GC group, both being significantly lower than those in the oral GC group. Total BMD, trabecular BMD, cortical BMD, relative cortical volume and SSI were similar between the first two, being significantly higher than in the last group. The slopes of cortical volume–density relationship, however, were identical among the three groups, indicating the persistence of cortical bone remodeling and a similar degree of calcification regardless of GC administration.