Yoshimori Ikeya

Comparison of eicosapentaenoic acid concentrations in plasma between patients with ischemic stroke and control subjects.

OBJECTIVE ω-3 fatty acids, including eicosapentaenoic acid (EPA), prevent ischemic stroke. However, the clinical importance of EPA for ischemic stroke and its subtype has not been fully elucidated. METHODS In a cross-sectional study, we determined whether ω-3 fatty acids were predictive factors for ischemic stroke. We compared common clinical parameters among 65 patients with ischemic stroke and 65 control subjects. The parameters included blood chemistry data; concentrations of EPA, docosahexaenoic acid, and arachidonic acid (AA); EPA/AA ratio; smoking; alcohol intake; fish consumption more than four times per week; and the incidence of underlying diseases. The comparisons were performed using the Mann-Whitney U test, and multiple logistic regression analysis was applied to the significant factors in the non-parametric test. We also applied the same approach to the ischemic stroke subtypes, cardioembolism and large-artery atherosclerosis. RESULTS In the multiple logistic regression analysis after the Mann-Whitney U test, a lower EPA concentration was one of the significant risk factors for ischemic stroke, as were a lower body mass index, lower high-density lipoprotein cholesterol, and smoking (sensitivity 0.846, specificity 0.831, positive predictive value 0.833). In the analysis of subtypes, a lower EPA/AA ratio and a lower body mass index were the significant risk factors for cardioembolism (sensitivity 0.800, specificity 0.733, positive predictive value 0.750). However, large-artery atherosclerosis was not related to the EPA concentration or the EPA/AA ratio. CONCLUSIONS In this study, the plasma EPA concentration and the EPA/AA ratio were potential predictive risk factors for ischemic stroke, especially for cardioembolism. Further prospective studies are necessary.

Low plasma eicosapentaenoic acid concentration as a possible risk factor for intracerebral hemorrhage

N-3 fatty acids, including eicosapentaenoic acid (EPA), prevent ischemic stroke. The preventive effect has been attributed to an antithrombic effect induced by elevated EPA and reduced arachidonic acid (AA) levels. However, the relationship between intracranial hemorrhage and N-3 fatty acids has not yet been elucidated. In this cross-sectional study, we compared common clinical and lifestyle parameters between 70 patients with intracranial hemorrhages and 66 control subjects. The parameters included blood chemistry data, smoking, alcohol intake, fish consumption, and the incidences of underlying diseases. The comparisons were performed using the Mann-Whitney U test followed by multiple logistic regression analysis. Nonparametric tests revealed that the 70 patients with intracerebral hemorrhages exhibited significantly higher diastolic blood pressures and alcohol intakes and lower body mass indices, high-density lipoprotein (HDL) cholesterol levels, EPA concentrations, EPA/AA ratios, and vegetable consumption compared with the 66 control subjects. A multiple logistic regression analysis revealed that higher diastolic blood pressure and alcohol intake and lower body mass index, HDL cholesterol, EPA/AA ratio, and vegetable consumption were relative risk factors for intracerebral hemorrhage. High HDL cholesterol was a common risk factor in both of the sex-segregated subgroups and the <65-year-old subgroup. However, neither EPA nor the EPA/AA ratio was a risk factor in these subgroups. Eicosapentaenoic acid was relative risk factor only in the ≥65-year-old subgroup. Rather than higher EPA levels, lower EPA concentrations and EPA/AA ratios were found to be risk factors for intracerebral hemorrhage in addition to previously known risk factors such as blood pressure, alcohol consumption, and lifestyle.

Altered blood flow in cerebral perforating arteries of rat models of diabetes: A synchrotron radiation microangiographic study toward clinical evaluation of white matter hyperintensities

As altered blood flow in the cerebral perforating arteries (PA) might be related to development of cerebral white matter hyperintensities, we examined whether the hemodynamic relationship of the PA and middle cerebral artery (MCA) is altered in rat models of diabetes, compared with normal rats and a rat model of sinoatrial denervation (blood pressure fluctuation model).

Common and specific risk factors for ischemic stroke in elderly: Differences based on type of ischemic stroke and aging

BACKGROUND The risk factors among the types of ischemic stroke (atherothrombotic cerebral infarction: ATI, cardio-embolic infarction: CEI, lacunar infarction: LI) in aged stroke patients have rarely been compared to each other. METHODS We compared the clinical parameters of 300 elderly patients with ischemic stroke, age 65-98years, to 100 age-matched control patients. RESULTS Comparison by parametric test and logistic regression analysis between all 300 and 100 control patients showed higher systolic and diastolic blood pressures (p<0.001, p=0.03), lower estimated glomerular filtration rate (eGFR) (p=0.01), larger cardiothoracic ratio (CTR) (p<0.001), smoking (p<0.01) and possibly poor adherence to anti-hypertensive agents in the ischemic stroke patients (p<0.001). Comparisons among three types (n=100 for each) showed the highest atheromatous risk factors for ATI to be hemoglobin A1c (p=0.01) and low-density lipoprotein (p<0.001) and for CEI to be largest cardiac load, indicated by largest left atrial dimension (p<0.001), and CTR (p<0.001). Triglyceride level was found to be a borderline risk factor for LI (p=0.054). Comparison between those aged <74 versus ≥75years (n=150 for each) showed a lower eGFR (p=0.02) and larger right atrial dimension (p<0.001) in patients ≥75. CONCLUSION The risk factors were quite different among the subtypes and aging.

Severity of white matter hyperintensities in older adults aged in their mid 80s and its relationship with hemodynamic and cardiac parameters

In the present study, we analyzed the severity of white matter hyperintensities detected on magnetic resonance imaging of the brain in older Japanese adults who were aged in their mid 80s, and examined its relationships with the clinical parameters.

Visualization of microvessels by angiography using inverse-Compton scattering X-rays in animal models

The fundamental performance of microangiography has been evaluated using the S-band linac-based inverse-Compton scattering X-ray (iCSX) method to determine how many photons would be required to apply iCSX to human microangiography. ICSX is characterized by its quasi-monochromatic nature and small focus size which are fundamental requirements for microangiography. However, the current iCSX source does not have sufficient flux for microangiography in clinical settings. It was determined whether S-band compact linac-based iCSX can visualize small vessels of excised animal organs, and the amount of X-ray photons required for real time microangiography in clinical settings was estimated. The iCSX coupled with a high-gain avalanche rushing amorphous photoconductor camera could visualize a resolution chart with only a single iCSX pulse of ∼3 ps duration; the resolution was estimated to be ∼500 µm. The iCSX coupled with an X-ray cooled charge-coupled device image sensor camera visualized seventh-order vascular branches (80 µm in diameter) of a rabbit ear by accumulating the images for 5 and 30 min, corresponding to irradiation of 3000 and 18000 iCSX pulses, respectively. The S-band linac-based iCSX visualized microvessels by accumulating the images. An iCSX source with a photon number of 3.6 × 10(3)-5.4 × 10(4) times greater than that used in this study may enable visualizing microvessels of human fingertips even in clinical settings.

Importance and proper use of fatty acid levels in vascular events.

We readwith interest the letterwritten by Dr Sertoglu regarding our study describing the relative relationship between intracerebral hemorrhage and eicosapentaenoic acid [1]. We are intrigued with the opinion that it would be better to measure the fatty acids in erythrocytesmembrane rather than inplasma. In our study, we acquired information about lifestyle and drug use from the patients with intracerebral hemorrhage and their families using a questionnaire that was applied on the day of hospital admission. The blood samples from the patients with intracerebral hemorrhages were obtained after fasting on the morning after hospital admission. In addition, we asked the control subjects about their present lifestyle factors and drug use at the time of their consultation. Likewise, blood samples from the control subjects were obtained after fasting on the morning of their consultation. As indicated in the Letter to the Editor from Dr Sertoglu, we recognize that fatty acid levels in plasma are susceptible to recent fatty acid intakes, whereas those in erythrocyte membrane are relatively stable [2-4]. However, many previous clinical trials, such as the Japan Eicosapentaenoic acid Lipid Intervention Study [5], used plasma samples. We considered that it is acceptable to use plasma because it is easily obtained for clinicians to screen patients and thus viable to submit as a sample for fatty acid analysis under these circumstances. In contrast, collection of erythrocytes for membrane isolation and subsequent analysis of fatty acids is laborious for the clinical setting. Therefore, based on the clinical setting, we used plasma samples in our study. Fatty acids are well-known important biomarkers for health and cardiovascular diseases [5-7]. We believe that measurement of plasma fatty acids should be extended from clinical studies to clinical applications. Alternatively, measurement of polyunsaturated fatty acids in erythrocytes, specificallymembranes, would be an attractive scientific target for future studies to extend our work.

Fingertip Synchrotron Radiation Angiography for Prediction of Diabetic Microangiopathy

Diabetic microangiopathy causes acetylcholine-induced paradoxical vasoconstriction in arterioles (20-200 μm). Because conventional angiographic systems lack sufficient spatial resolution (100-200 μm), they are not useful for prediction of diabetic microangiopathy and for the prevention of lethal cardiovascular diseases.