Hypertension: Ueno Y

Furukawa T, Nukada T, Namiki Y, Miyashita Y, Hatsuno K, Ueno Y, Yamakawa T, Isshiki T. · Department of Internal Medicine, Teikyo University School of Medicine, Kaga, Tokyo, Japan. · Eur J Pharmacol. · Pubmed #19401195 No free full text.

Abstract: 1,4-dihydropyridine (DHP) Ca(2+) antagonists have recently been shown to block T-type Ca(2+) channels, which may render favorable actions on cardiovascular systems. However, this evaluation remains to be done systematically for each T-type Ca(2+) channel subtype except for the Ca(v)3.1 (alpha(1G)) subtype. To address this issue at the molecular level, blocking effects of 14 kinds of DHPs (amlodipine, aranidipine, azelnidipine, barnidipine, benidipine, cilnidipine, efonidipine, felodipine, manidipine, nicardipine, nifedipine, nilvadipine, nimodipine, nitrendipine), which are clinically used for treatments of hypertension, on 3 subtypes of T-type Ca(2+) channels [Ca(v)3.2 (alpha(1H)), Ca(v)3.3 (alpha(1I)), and Ca(v)3.1 (alpha(1G))] were investigated in the Xenopus oocyte expression system using the two-microelectrode voltage-clamp technique. These 3 kinds (alpha(1H), alpha(1I) and alpha(1G)) of T-type channels were blocked by amlodipine, manidipine and nicardipine. On the other hand, azelnidipine, barnidipine, benidipine and efonidipine significantly blocked alpha(1H) and alpha(1G), but not alpha(1I) channels, while nilvadipine and nimodipine apparently blocked alpha(1H) and alpha(1I), but not alpha(1G) channels. Moreover, aranidipine blocked only alpha(1H) channels. By contrast, cilnidipine, felodipine, nifedipine and nitrendipine had little effects on these subtypes of T-type channels. The result indicates that the blockade of T-type Ca(2+) channels by derivatives of DHP Ca(2+) antagonist was selective for the channel subtype. Therefore, these selectivities of DHPs in blocking T-type Ca(2+) channel subtypes would provide useful pharmacological and clinical information on the mode of action of the drugs including side-effects and adverse effects.

Furukawa T, Hatsuno T, Ueno Y, Nagaoka K, Watari Y, Yamakawa T, Sagawa T, Isshiki T. · Department of Internal Medicine, School of Medicine, Teikyo University, Teikyo, Japan. · Clin Drug Investig. · Pubmed #19301939 No free full text.

Abstract: BACKGROUNDS AND METHODS: A higher degree of clinical efficacy with olmesartan compared with other angiotensin receptor blockers, has been reported by several sources. In this study of 31 examples of cases of essential hypertension, Holter electrocardiogram, ambulatory blood pressure monitoring and pulse wave velocity (PWV) measurements were performed before and after substituting olmesartan 20 mg for candesartan 8 mg antihypertensive drug therapy. RESULTS: Following the therapeutic change, daily average systolic and diastolic blood pressures were decreased by 6.7 +/- 9.3 mmHg and 3.6 +/- 8.3 mmHg, respectively, with olmesartan 20 mg; PWV was also significantly decreased. Holter electrocardiogram heart rate variability spectral analysis demonstrated that none of the very low frequency (VLF), high frequency (HF) and low frequency (LF)/HF components were significantly altered. However, a significant correlation was observed between the LF/HF component and blood pressure difference, when blood pressure and heart rate variability components in each individual case were studied. CONCLUSION: This study shows that olmesartan has a stronger antihypertensive effect in comparison to candesartan, and does not generate reflex sympathoexcitatory activity.

Ueno Y, Iguchi Y, Inoue T, Shibazaki K, Urabe T, Kimura K. · Stroke center, Dept. of Stroke Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama, 701-0192, Japan. · J Neurol. · Pubmed #17380241 No free full text.

Abstract: BACKGROUND : Proving that right-to-left shunt (RLS) represents the precise causative mechanism in ischemic stroke patients with RLS is difficult. The aim of this study was to examine the frequency and clarify the clinical characteristics of paradoxical brain embolism (PBE). METHODS : We prospectively enrolled consecutive acute ischemic stroke patients, who underwent transcranial Doppler and/or transesophageal echocardiography. For patients with RLS, diagnostic criteria for PBE were established as follows: 1) brain images suggesting embolic strokes; 2) presence of deep venous thrombus or pulmonary embolism; and 3) absence of any embolic sources. Patients were divided into 4 groups: patients meeting all 3 criteria (Definite); fulfilling 2 criteria (Probable); fulfilling 1 or 0 criteria (Possible); and patients without RLS (Non-RLS). RESULTS : A total of 240 subjects were analyzed for this study. The Definite group comprised 5% of patients, and displayed significantly more females (p = 0.038), and infarcts involving both anterior and posterior circulations (p < 0.001). Patients having neither hypertension nor diabetes mellitus also predominantly belonged to the Definite group (p < 0.001). CONCLUSIONS : Clinical characteristics of PBE are a female preponderance, infarcts affecting both anterior and posterior circulations, and an absence of risk factors.

Ueno Y, Kimura K, Iguchi Y, Shibazaki K, Inoue T, Urabe T. · Stroke Center, Department of Stroke Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama, 701-0192, Japan. · Neurology. · Pubmed #17296920 No free full text.

Abstract: We analyzed the frequency of cardiac embolic sources in 62 patients with acute lacunar stroke vs 50 controls. In post hoc analysis, 11 patients with lacunar stroke having neither hypertension nor diabetes mellitus (non-HDM group) had a higher frequency of right-to-left shunt (RLS) (82%) than patients with risk factors for lacunar stroke. RLS was also independently associated with the non-HDM group. Thus, RLS may contribute to lacunar stroke in patients without risk factors for lacunar stroke.

Ueno Y, Takagi A, Kawana M, Kasanuki H. · Department of Cardiology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan. · Heart Vessels. · Pubmed #15700201 No free full text.

Abstract: We experienced a 78-year-old man in whom transient pulmonary hypertension was documented during epileptic seizure. A Swan-Ganz catheter demonstrated that pulmonary arterial pressure rose immediately after the initiation of the seizure, which was followed by systemic hypertension. The plasma level of angiotensin II increased in pulmonary circulation during the seizures; however, catecholamines did not change from the baseline. The patient responded well to treatment with an antiepileptic drug and losartan potassium.

Suzuki N, Kozuma K, Ueno Y, Nagaoka K, Kyono H, Ishikawa S, Watanabe H, Yokoyama N, Takeshita S, Isshiki T. · Department of Medicine, Teikyo University School of Medicine, Tokyo, Japan. · Ann Thorac Surg. · Pubmed #18222257 No free full text.

Abstract: BACKGROUND: A paucity of data exists with respect to changes in whole saphenous vein grafts (SVGs) despite accelerated atherosclerosis within grafted saphenous vein conduits. In the present study, we evaluated the one-year change in SVGs by means of quantitative coronary analysis. METHODS: This study enrolled consecutive 52 patients with 109 SVGs, who underwent coronary artery bypass graft surgery successfully. A follow-up study was performed in 33 patients with 65 SVGs after one year because 16 SVGs were obstructed (baseline, 8; follow-up period, 8), and 15 patients with 28 SVGs dropped out within one year. RESULTS: Both minimal and mean lumen diameters decreased significantly (3.17 +/- 0.64 mm vs 2.41 +/- 0.57 mm, p < 0.001; 3.70 +/- 0.69 mm vs 2.92 +/- 0.70 mm, p < 0.001; respectively). Graft length also decreased significantly (107.1 +/- 25.8 vs 100.6 +/- 25.2 mm, p < 0.001). The graft shortening rate (graft shortening length/baseline graft length x 100) was greater than 5% in 33 vessels (51%) and greater than 10% in 23 vessels (35%). Coronary risk factors (smoking, diabetes mellitus, hypertension, dyslipidemia) did not reveal significant relationship with late loss of minimal and mean lumen diameters. CONCLUSIONS: The present study showed a considerable and uniform lumen loss of SVGs after one year, irrespective of coronary risk factors. Graft length shortening was seen more than elongation.