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ABSTRACT: OBJECTIVE:: We developed a new technique to measure blood pressure (BP) - the triple cuff and pulse delay time technique (TC-PDT) - which measures delay time with a single sensor at a single site unlike the existing delay time methods. This study aimed to evaluate the adequacy and accuracy of TC-PDT. METHODS:: TC-PDT measures delay time, which represents the difference in the arrival time of the arterial pulse wave between the proximal and distal areas of the cuff and provides clear criteria for BP determination based on the mechanism. Adequacy of delay time in TC-PDT was confirmed in comparison with established delay time of the pulse transit time technique (PTT). TC-PDT accuracy was evaluated according to the standard guidelines. RESULTS:: In TC-PDT, delay time showed changes in parallel with those observed in PTT. The correlation coefficient between BP by TC-PDT and that by PTT was 0.98 (P < 0.01) for SBP and 0.93 (P < 0.01) for DBP. According to the International Protocol guidelines (2002), the BP measurements of 33 patients met the recommended values for phase 1, 2.1 and 2.2 measurements. As per the Association for the Advancement of Medical Instrumentation (AAMI) SP10 guidelines (2002), the mean difference in BP measured by TC-PDT and that measured by the auscultatory technique in 85 patients was 1.0 ± 5.1 mmHg for SBP and -0.4 ± 4.5 mmHg for DBP, which conformed to the requirements. CONCLUSION:: TC-PDT is adequate to measure delay time and provides adequate and accurate measurements of BP. This device has the potential to be a standard tool for indirect BP measurement.
Journal of hypertension 12/2012; · 4.02 Impact Factor
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ABSTRACT: Residual renal function preservation in patients with renal failure has been shown to be related to better outcomes not only in the pre-dialysis phase but also after hemodialysis initiation. However, the effect of factors such as antihypertensive agents on residual renal function preservation has not been investigated adequately in prevalent hemodialysis patients. This study examined factors related to the rate of residual renal function preservation in 1-year hemodialysis patients who had residual renal function. We enrolled 191 consecutive maintenance hemodialysis patients who underwent hemodialysis for 1 year and maintained a urine output of more than 200 mL/day, to assess residual renal function loss. The rate of residual renal function loss was 19.9%. Multivariate analysis using residual renal function as the dependent variable revealed significant independent relationships with renin-angiotensin system inhibitor use (hazard ratio, 0.438; P = 0.027), history of cardiovascular disease (hazard ratio, 2.475; P = 0.024), and rate of weight gain between dialysis sessions (hazard ratio, 1.348; P = 0.013). No relationship was observed with calcium channel blocker use. Renin-angiotensin system inhibitor use, rate of body weight gain between dialysis sessions, and cardiovascular diseases are independently associated with residual renal function preservation in patients with residual renal function after 1 year of hemodialysis. A further intervention study is required to investigate whether treatment with renin-angiotensin system inhibitors and suppression of body weight gain preserves residual renal function for a longer time in hemodialysis patients.
Therapeutic apheresis and dialysis: official peer-reviewed journal of the International Society for Apheresis, the Japanese Society for Apheresis, the Japanese Society for Dialysis Therapy 12/2012; 16(6):554-9. · 1.39 Impact Factor
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ABSTRACT: Accumulated evidence suggests that an altered ambulatory blood pressure (BP) profile, particularly elevated nighttime BP, reflects target organ injury and is a better predictor of further cardiorenal risk than the clinic BP or daytime BP in hypertensive patients complicated by chronic kidney disease (CKD). In this study, we examined the beneficial effects of olmesartan, an angiotensin II type 1 receptor blocker (ARB), on ambulatory BP profiles and renal function in hypertensive CKD patients. Forty-six patients were randomly assigned to the olmesartan add-on group (n=23) or the non-ARB group (n=23). At baseline and after the 16-week treatment period, ambulatory BP monitoring was performed and renal function parameter measurements were collected. Although the baseline clinic BP levels and the after-treatment/baseline (A/B) ratios of clinic BP levels were similar in the olmesartan add-on and non-ARB groups, the A/B ratios of ambulatory 24-h and nighttime BP levels in the olmesartan add-on group were significantly lower. Furthermore, the A/B ratios of urinary protein, albumin and type IV collagen excretion in the olmesartan add-on group were significantly lower than those in the non-ARB group (urinary protein excretion, 0.72±0.41 vs. 1.45±1.48, P=0.030; urinary albumin excretion, 0.73±0.37 vs. 1.50±1.37, P=0.005; urinary type IV collagen excretion, 0.87±0.42 vs. 1.48±0.87, P=0.014) despite comparable A/B ratios for the estimated glomerular filtration rate in the two groups. These results indicate that in hypertensive patients with CKD, olmesartan add-on therapy improves the ambulatory BP profile via a preferential reduction in nighttime BP with concomitant renal injury inhibition.Hypertension Research advance online publication, 15 November 2012; doi:10.1038/hr.2012.184.
Hypertension Research 11/2012; · 2.58 Impact Factor
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Tomohiko Kanaoka,
Kouichi Tamura,
Masato Ohsawa,
Hiromichi Wakui,
Akinobu Maeda,
Toru Dejima,
Kengo Azushima,
Sona Haku,
Hiroshi Mitsuhashi,
Mai Yanagi,
Jin Oshikawa,
Kazushi Uneda,
Kazutaka Aoki, Tetsuya Fujikawa,
Yoshiyuki Toya,
Kazuaki Uchino,
Satoshi Umemura
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ABSTRACT: Aliskiren is a direct renin inhibitor that exerts its effect at the rate-limiting step of the renin-angiotensin system. This study was performed to examine the beneficial effects of aliskiren-based antihypertensive therapy on the ambulatory blood pressure (BP) profile, central hemodybamics, and arterial stiffness in untreated Japanese patients with mild to moderate hypertension. Twenty-one Japanese nondiabetic patients with untreated mild to moderate essential hypertension were initially given aliskiren once daily at 150 mg, and the dose was titrated up to 300 mg as needed. After 12 weeks of aliskiren-based therapy, the clinic, ambulatory, and central BP values as well as brachial-ankle pulse wave velocity (baPWV) were all significantly decreased compared with baseline (clinic systolic BP, 151 ± 11 mm Hg vs 132 ± 11 mm Hg; clinic diastolic BP, 91 ± 13 mm Hg vs 82 ± 9 mm Hg; 24-hour systolic BP, 144 ± 12 mm Hg vs 133 ± 11 mm Hg; 24-hour diastolic BP, 88 ± 8 mm Hg vs 81 ± 9 mm Hg; central BP, 162 ± 16 mm Hg vs 148 ± 14 mm Hg; baPWV, 1625 ± 245 cm/s vs 1495 ± 199 cm/s; P<.05). These results show that aliskiren, as a first-line regimen, improves the ambulatory BP profile and may have protective vascular effects in Japanese nondiabetic patients with untreated mild to moderate essential hypertension.
Journal of Clinical Hypertension 08/2012; 14(8):522-9. · 1.83 Impact Factor
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Tomohiko Kanaoka,
Kouichi Tamura,
Masato Ohsawa,
Mai Yanagi,
Sona Haku,
Hiromichi Wakui,
Akinobu Maeda,
Toru Dejima,
Kengo Azushima,
Hiroshi Mitsuhashi,
Yasuko Okano, Tetsuya Fujikawa,
Yoshiyuki Toya,
Shunsaku Mizushima,
Osamu Tochikubo,
Satoshi Umemura
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ABSTRACT: Strict blood pressure (BP) control is reportedly important for the management of hypertensive patients with chronic kidney disease (CKD). The purpose of this cross-sectional study was to examine whether the variables of ambulatory BP and the heart rate (HR) profile, central hemodynamics, and arterial stiffness were closely related to the renal function parameters (urine albumin excretion rate [UACR] and estimated glomerular filtration rate [eGFR]) observed in 25 consecutive hospitalized hypertensive patients with CKD. There were significant positive relationships between UACR and 24-hour, daytime, and nighttime ambulatory systolic BP. In addition, there were significant negative relationships between UACR and 24-hour and daytime HR variability. The circulating B-type natriuretic peptide level and hemoglobin A1c were also positively related to UACR. With respect to eGFR, although the 24-hour and nighttime HR variability were positively associated with eGFR, the circulating pentosidine and nighttime HR had a negative relationship with eGFR. On the other hand, central hemodynamics and arterial stiffness did not exhibit any significant association with renal function parameters. These results indicate that ambulatory BP and the HR profile are closely modulated by renal function deterioration. Further studies are needed to investigate the causal relationship between ambulatory BP and the HR profile and renal function parameters in hypertensive patients with CKD.
Clinical and Experimental Hypertension 05/2012; 34(4):264-9. · 1.07 Impact Factor
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Akinobu Maeda,
Kouichi Tamura,
Tomohiko Kanaoka,
Masato Ohsawa,
Sona Haku,
Kengo Azushima,
Toru Dejima,
Hiromichi Wakui,
Mai Yanagi,
Yasuko Okano, Tetsuya Fujikawa,
Yoshiyuki Toya,
Shunsaku Mizushima,
Osamu Tochikubo,
Satoshi Umemura
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ABSTRACT: Recent guidelines recommend combination antihypertensive therapy to achieve the target blood pressure (BP) and to suppress target organ damage. This study aimed to examine the beneficial effects of combination therapy with candesartan and amlodipine on BP control and markers of target organ function in Japanese essential hypertensive patients (N = 20) who did not achieve the target BP level during the monotherapy period with either candesartan or amlodipine. After the monotherapy period, for patients already being treated with amlodipine, a once-daily 8 mg dose of candesartan was added on during the combination therapy period (angiotensin II receptor blocker [ARB] add-on group, N = 10), and a once-daily 5 mg dose of amlodipine was added on for those already being treated with candesartan (calcium channel blocker [CCB] add-on group, N = 10). Combination therapy with candesartan and amlodipine for 12 weeks significantly decreased clinic and home systolic blood pressure (SBP) and diastolic blood pressure (DBP). In addition, the combination therapy was able to significantly reduce urine albumin excretion without decrease in estimated glomerular filtration ratio and resulted in significant improvements in brachial-ankle pulse wave velocity, central SBP, and insulin sensitivity. Furthermore, the CCB add-on group showed a significantly greater decrease in clinic and home DBP than the ARB add-on group. The calcium channel blocker add-on group also exhibited better improvements in vascular functional parameters than the ARB add-on group. These results suggest that combination therapy with candesartan and amlodipine is an efficient therapeutic strategy for hypertension with pleiotropic benefits.
Clinical and Experimental Hypertension 05/2012; 34(4):249-57. · 1.07 Impact Factor
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ABSTRACT: Mechanisms that regulate the number of cells constituting the body have remained largely elusive. We approached this issue in the ascidian, Halocynthia roretzi, which develops into a tadpole larva with a small number of cells. The embryonic cells divide 11 times on average from fertilization to hatching. The number of cell division rounds varies among tissue types. For example, notochord cells divide 9 times and give rise to large postmitotic cells in the tadpole. The number of cell division rounds in partial embryos derived from tissue-precursor blastomeres isolated at the 64-cell stage also varied between tissues and coincided with their counterparts in the intact whole embryos to some extent, suggesting tissue-autonomous regulation of cell division. Manipulation of cell fates in notochord, nerve cord, muscle, and mesenchyme lineage cells by inhibition or ectopic activation of the inductive FGF signal changed the number of cell divisions according to the altered fate. Knockdown and missexpression of Brachyury (Bra), an FGF-induced notochord-specific key transcription factor for notochord differentiation, indicated that Bra is also responsible for regulation of the number of cell division rounds, suggesting that Bra activates a putative mechanism to halt cell division at a specific stage. The outcome of precocious expression of Bra suggests that the mechanism involves a putative developmental clock that is likely shared in blastomeres other than those of notochord and functions to terminate cell division at three rounds after the 64-cell stage. Precocious expression of Bra has no effect on progression of the developmental clock itself.
Developmental Biology 07/2011; 355(2):313-23. · 4.07 Impact Factor
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Tomohiko Kanaoka,
Kouichi Tamura,
Tatsumi Moriya,
Keiji Tanaka,
Yusuke Konno,
Satoshi Kondoh,
Masao Toyoda,
Tomoya Umezono, Tetsuya Fujikawa,
Masato Ohsawa, [......],
Sona Haku,
Mai Yanagi,
Hiroshi Mitsuhashi,
Motoko Ozawa,
Yasuko Okano,
Nariaki Ogawa,
Tadashi Yamakawa,
Shunsaku Mizushima,
Daisuke Suzuki,
Satoshi Umemura
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ABSTRACT: Accumulating evidence has shown that diabetic patients are increasing in number, and renal and cardiovascular complications are the most common cause of death in diabetic patients. Thus, it would be of considerable value to identify the mechanisms involved in the progression of renal impairment and cardiovascular injury associated with diabetes. Recent evidence also indicated that multifactorial intervention is able to reduce the risk of cardiovascular disease and death among patients with diabetes and microalbuninuria. In this pilot study, we examined the effects of intensified multifactorial intervention, with tight glucose regulation and the use of valsartan and fluvastatin on ambulatory blood pressure (BP) profile, estimated glomerular filtration rate (eGFR), and urinary albumin to creatinine ratio (UACR), in 20 hypertensive patients (16 male and 4 female) with type 2 diabetes mellitus and overt nephropathy. After 12 months of intensified treatment, office BP, fasting plasma glucose (FPG), and low-density lipoprotein cholesterol (LDLC) were significantly decreased compared to baseline (systolic blood pressure (SBP), 130 ± 2 vs. 150 ± 1 mmHg; diastolic blood pressure (DBP), 76 ± 1 vs. 86 ± 1 mmHg; FPG, 117 ± 5 vs. 153 ± 7 mg/dl; LDLC, 116 ± 8 vs. 162 ± 5 mg/dl, P < 0.0001). Also, compared to the baseline values, the daytime and nighttime ambulatory BP and short-term BP variability were significantly decreased after 12 months. Furthermore, while eGFR was not altered (44.3 ± 5.1 vs. 44.3 ± 6.5 ml/min/1.73 m(2), not significant (NS)), UACR showed a significant reduction after 12 months of intensified treatment (1228 ± 355 vs. 2340 ± 381 mg/g-cr, P < 0.05). These results suggest that the intensified multifactorial intervention is able to improve ambulatory BP profile, preserve renal function, and reduce urinary albumin excretion in type 2 diabetic hypertensive patients with overt nephropathy.
Clinical and Experimental Hypertension 01/2011; 33(4):255-63. · 1.07 Impact Factor
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ABSTRACT: Variation in 24-h blood pressure (BP) is associated with multiple factors, but the association has not been thoroughly examined in young adults. To elucidate the potential factors associated with variation in 24-h BP, 331 healthy medical students were investigated. Awake mean BP negatively correlated with sleep duration in males. Sixty-seven subjects (20.2%) had a high 24-h BP according to the ESH/ESC 2007 guidelines (systolic blood pressure (SBP) 125 and/or diastolic blood pressure (DBP) 80 mmHg). After multivariate analysis for confounding factors, male gender, body mass index (BMI), smoking, the 24-h low/high frequency component (heart rate variability spectral analysis), and short sleep (5 h or less) were found to be associated with high BP. The present study is the first to demonstrate the multivariate risk factors for elevated 24-h BP in a large number of young adults. Further investigation is required to determine the causal relationship between modifiable BP-related factors and elevated 24-h BP in young adults.
Clinical and Experimental Hypertension 11/2009; 31(8):705-12. · 1.07 Impact Factor
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ABSTRACT: Patients with orthostatic hypotension have pathologic hemodynamics related to changes in body posture. A new cephalic laser blood flowmeter that can be worn on the tragus to investigate the hemodynamics upon rising from a sitting or squatting posture was developed.
The relationship between cephalic hemodynamics and cerebral ischemic symptoms in 63 subjects in a sitting, squatting, and standing positions using the new device was evaluated. Transient decrease in blood pressure within 15 s after rising to an erect position possibly causes dizziness, syncope, and fall. Subjects exhibiting dizziness upon standing showed a significant decrease in the cephalic blood flow (CBF) and indirect beat-to-beat systolic blood pressure, as monitored by the Finometer, and a significant correlation was observed between the drop ratio (drop value on rising/mean value in the squatting position) of CBF and that of systolic blood pressure.
This new wearable CBF-meter is potentially useful for estimating cephalic hemodynamics and objectively diagnosing cerebral ischemic symptoms of subjects in a standing posture.
Circulation Journal 09/2009; 73(10):1950-5. · 3.77 Impact Factor
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ABSTRACT: The genome of Ciona intestinalis contains eight genes for HSP70 superfamily proteins, 36 genes for J-proteins, a gene for a J-like protein, and three genes for BAG family proteins. To understand the stress responses of genes in the HSP70 chaperone system comprehensively, the transcriptional profiles of these 48 genes under heat stress and endoplasmic reticulum (ER) stress were studied using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Heat stress treatment increased the messenger RNA (mRNA) levels of six HSP70 superfamily genes, eight J-protein family genes, and two BAG family genes. In the cytoplasmic group of the DnaK subfamily of the HSP70 family, Ci-HSPA1/6/7-like was the only heat-inducible gene and Ci-HSPA2/8 was the only constitutively active gene which showed striking simplicity in comparison with other animals that have been examined genome-wide so far. Analyses of the time course and temperature dependency of the heat stress responses showed that the induction of Ci-HSPA1/6/7-like expression rises to a peak after heat stress treatment at 28 degrees C (10 degrees C upshift from control temperature) for 1 h. ER stress treatment with Brefeldin A, a drug that is known to act as ER stress inducer, increased the mRNA levels of four HSP70 superfamily genes and four J-protein family genes. Most stress-inducible genes are conserved between Ciona and vertebrates, as expected from a close evolutionary relationship between them. The present study characterized the stress responses of HSP70 chaperone system genes in Ciona for the first time and provides essential data for comprehensive understanding of the functions of the HSP70 chaperone system.
Cell Stress and Chaperones 08/2009; 15(2):193-204. · 3.01 Impact Factor
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ABSTRACT: The aim of the present study was to measure peripheral blood flow (BF) with a new finger-occlusion plethysmograph (FOP) and to compare this to BF measured with a laser Doppler flowmeter (LDF). An additional objective was to investigate the relationship between hypertension-related clinical parameters and peripheral vascular resistance (PVR) estimated from BF and mean blood pressure (BP) (PVR=mean BP/BF) in young subjects.
The present study employed 101 young volunteers (61 males, 40 females, mean age 23.2+/-2.5 years). The FOP was attached to the third finger and an LDF to the fourth fingertip of each subject. BF was measured simultaneously by the 2 devices. A multi-biomedical recorder (TM2425) measured 24-h BP. A high correlation was observed between BF measured by the FOP and LDF (r=0.79, p<0.001). In multiple linear regression analysis, PVR was independently correlated with a family history of hypertension (p<0.01) and with base diastolic BP during sleep (p<0.01), which is a sensitive predictor of severity of hypertension.
Our newly developed FOP can estimate peripheral absolute BF easily. Furthermore, BF determined by the FOP can be used to calculate PVR, and an elevated PVR may be a useful predictor of hypertension.
Circulation Journal 08/2008; 72(8):1329-35. · 3.77 Impact Factor
