Toshinari Tanaka

Effect of atrial natriuretic peptide on adiponectin in patients with heart failure

The adipocyte‐specific cytokine adiponectin, has cardioprotective effects, correlates with endogenous cardiac natriuretic peptides and adipocyte has guanylyl cyclase‐A receptors of natriuretic peptides.

Comparison of the Effects of Efonidipine and Amlodipine on Aldosterone in Patients with Hypertension

To prevent cardiovascular disease, targeting aldosterone synthesis and release may be clinically important. Aldosterone production in the adrenal gland is mediated mainly by the T-type calcium channel in vitro. Efonidipine inhibits both L- and T-type Ca channels. To compare the effects of efonidipine on neurohumoral factors with those of amlodipine, an L-type Ca channel blocker, we studied 40 essential hypertensive outpatients. Forty patients who had been administered amlodipine for more than 1 year were treated with efonidipine for 6 months in place of amlodipine. Substituting efonidipine for amlodipine had no significant effect on clinic systolic blood pressure or the plasma levels of brain natriuretic peptide, norepinephrine or active renin. However, the heart rate was significantly decreased (72.0±1.3 vs. 69.8±1.3 beats/min, p<0.01) and the plasma aldosterone level was also significantly decreased after efonidipine treatment (97.7±7.9 vs. 79.7±5.6 pg/mL, p<0.0001). Changes in the aldosterone level correlated with the baseline value before the replacement of amlodipine by efonidipine (r=−0.769, p<0.0001). These findings indicate that at the effective antihypertensive doses of efonidipine and amlodipine, efonidipine significantly decreases heart rate and plasma aldosterone level compared with those under amlodipine treatment in hypertensive patients.

Plasma level of cardiotrophin-1 as a prognostic predictor in patients with chronic heart failure.

Cardiotrophin‐1 (CT‐1) is a member of the interleukin (IL‐6) family of cytokines and is increased in patients with chronic heart failure (CHF).

Direct comparison of transcardiac difference between brain natriuretic peptide (BNP) and N-terminal pro-BNP in patients with chronic heart failure.

Direct comparison of transcardiac increase in brain natriuretic peptide (BNP) and NT‐pro‐BNP has not been performed previously.

Transcardiac increase in norepinephrine and prognosis in patients with chronic heart failure.

No previous study has compared the transcardiac gradient of norepinephrine (NE) and the prognosis of patients with chronic heart failure (CHF).

Long-term effect of efonidipine therapy on plasma aldosterone and left ventricular mass index in patients with essential hypertension.

A certain percentage of aldosterone (ALD) breakthrough generally occurs in patients with hypertension and chronic heart failure and is an important issue during long-term treatment with angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARB). It has been reported that efonidipine decreases the plasma levels of ALD. However, the long-term effects of efonidipine on the plasma levels of ALD and the left ventricular mass index (LVMI) remain unknown in patients with hypertension. Sixty stable outpatients with essential hypertension who had received amlodipine and ACE-I or ARB for more than 1 year were randomized into two groups (amlodipine group (n=30): continuous amlodipine treatment at a stable dose; efonidipine group (n=30): amlodipine (5 mg day−1) was changed to efonidipine at a dose of 40 mg day−1). There was no difference in their baseline characteristics including the LVMI and plasma levels of ALD. In the amlodipine group, there were no significant changes in blood pressure, LVMI or plasma levels of ALD for 18 months. In the efonidipine group, blood pressure did not change after replacement of amlodipine with efonidipine, although there was a significant decrease in the plasma levels of ALD after 6 months. The decrease in ALD was sustained for 18 months and LVMI was significantly decreased after 18 months (121±25 vs. 114±21 g m−2, P<0.05). There was a significant correlation between the changes in LVMI and % changes of ALD in the efonidipine group. These findings indicate that the effect of efonidipine on the suppression of plasma ALD was sustained for at least 18 months and that long-term efonidipine therapy decreases LVMI in patients with essential hypertension.

Autonomous Towed Vehicle for Underwater Inspection in a Port Area

This paper discusses an autonomous towed vehicle for underwater inspection in a port area, in which a sea current is so fast and complex. The autonomous towed vehicle has three different navigation modes; towed mode, autonomous mode and kite mode, to assure safe and reliable inspection in such a port area. An autonomous underwater vehicle (AUV) is employed as a towed vehicle to increase autonomy. In towed systems, it is important to monitor a towed force for preventing cable breaks and making use of it more efficiently since a towing cable plays an important role in transmitting electric signals and towing forces. In this paper, we propose a sequence for towed force estimation consisting of different navigation modes and control methods for it. In addition, the navigation control system of the autonomous towed vehicle is briefly described. Simulations to verify the towed force estimation and control methods are carried out and the results are discussed.

Design concept of a prototype amphibious walking robot for automated shore line survey work

There are many waterside areas such as shoals or shore lines in the port areas. One of the main work is survey work in such areas. For instance, the port authorities survey the shore lines to maintain encroached beach. Tidal flats are also surveyed to monitor the environment and the ecosystem. Some of the work in the areas are carried out on weak terrain. Consequently, the primary work force is still human-intensive although the mechanization and automatization are desired from the viewpoint of efficiency. Therefore, we are on the study of automated topographic survey work in waterside areas such as shore line. We consider that this is the same also in the waterside or underwater because walking machine does not damage the terrain seriously. We have verified the validity of the countermeasure suggested by us in the experiment on land. Consequently, we have started the development of a prototype amphibious walking robot which has some unique features in the structure and composition in order to experiment our proposed method in real sea. One of the structural features is the same mechanism of all joints, and they are independent respectively to each other as watertight type joint units. This feature contributes to the simplicity of the composition of the robot. Another structural feature is that the legs and the body unit are able to be detached easily in case of the maintenance. A design concept and the features of the prototype amphibious walking robot would be described in detail. And, the progress of development of the prototype robot would be reported.

Effect of an angiotensin II type 1 receptor blocker, valsartan, on neurohumoral factors in patients with hypertension: comparison with a long-acting calcium channel antagonist, amlodipine.

Summary: This study compared the effects of amlodipine and valsartan on the sympathetic nervous system, the renin‐angiotensin‐ aldosterone system, and brain natriuretic peptide, which are considered important parameters of the long‐term prognosis. Seventythree elderly patients, who had received antihypertensive treatment for more than 6 months with amlodipine, participated in this study. They were randomized to the V group (n = 36) and switched to valsartan from amlodipine, or to the A group (n = 37), which continued treatment with amlodipine. The dose of valsartan was set as that which controlled the blood pressure to the same extent as before switching. Blood samples were measured before and after 6 months of therapy. Data were analyzed by two‐way analysis of variance with the Newman‐Keuls test. In the V group, norepinephrine (from 597.0 ± 52.9 to 475 ± 43.8 pg/ml, p < 0.05) and aldosterone (from 74.5 ± 7.0 to 53.9 ± 5.3 pg/ml, p < 0.001) were decreased significantly after 6 months, although norepinephrine and aldosterone levels were unchanged in the A group. However, brain natriuretic peptide did not show a difference between the two groups. These findings suggested that valsartan is probably superior to amlodipine with respect to less activation of the sympathetic nervous system and preventing upregulation of the renin‐angiotensin‐aldosterone system.

Autonomous Spilled Oil and Gas Tracking Buoy System and Application to Marine Disaster Prevention System: Part 1

This paper describes the ongoing project on autonomous spilled oil and gas tracking buoy system and application to marine disaster prevention system for 5 years since FY2011. Objectives of this project are as (1)autonomous tracking and monitoring of spilled plumes of oil and gas from subsea production facilities by an underwater buoy robot, (2)autonomous tracking of spilled oil on the sea surface and transmission of useful data to a land station through satellites in real time by multiple floating buoy robots, (3)improvement of the accuracy of simulations for predicting diffusion and drifting of spilled oil and gas by incorporating the real-time data from these robots. To realize (1) and (2) objectives, we have developed an autonomous underwater robot named SOTAB-I, and an autonomous surface vehicle named SOTAB-II. To realize (3) objective, Data fusion methods in the simulation models incorporating real time measured data not only from a SOTAB-I for gas and oil blowouts, but also from multiple SOTAB-IIs for spilled oil drifting on sea surface were developed.