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Biomedical subjects

Osamu Tochikubo

Publications and source records attributed to Osamu Tochikubo.

At least 19 recordsLinked to original sources
PubMed2007

Exclusion of influence of physical activity on ambulatory blood pressure.

OBJECTIVE: The basal blood pressure (BP) is more intimately related to hypertension severity than casual BP. BP values obtained by ambulatory blood pressure monitoring (ABPM) tend to be influenced by patients' physical activity because values are not always obtained with the patient at rest. The purpose of this study was to estimate the influence of physical activity on BP and determine daytime BP adjusted for activity as measured by ABPM. METHODS: This study targeted three clinically different groups: healthy medical students (HS, n = 40), patients with hypertension (HT, n = 20), and patients with diabetes mellitus (DM, n = 7). The subjects' BP, heart rate (HR), and physical activity level were measured by a noninvasive portable multi-biomedical recorder. To identify the influence of physical activity on BP in the three study groups, a least squares regression analysis of the relation between BP and ACT (an index of activity with acceleration) was performed for each group. RESULTS: ACT had a positive influence on systolic BP (SBP) in the HS, HT, and DM groups (R2 = 0.319, 0.576, 0.697, respectively). SBP adjusted for ACT (walking level) by means of the regression model with dummy variable was 0-24 mmHg lower than the value of SBP measured by ABPM, and daytime SBP (walking level) was overestimated by approximately 10 mmHg in comparison to the value of SBP at rest (ACT = 0). CONCLUSION: Physical activity had a positive effect on SBP. The results showed that physical activity (walking-level) had a positive effect on SBP of about 10 mmHg.

Adult↗
PubMed2007

Relation between nocturnal arterial oxygen desaturation and morning blood pressure.

OBJECTIVE: Arterial oxygen saturation (SpO2) in volunteers had been previously investigated, and the possibility that a decrease in SpO2 leads to an increase in blood pressure (BP) in airline passengers experiencing oxygen desaturation at high altitudes was reported. It was also shown that mean nocturnal SpO2 was lower in subjects with high-normal BP or mild hypertension than in those with normal BP. The present study investigated nocturnal SpO2, evening BP, and morning BP of volunteers during daily life and examined the relation between nocturnal SpO2 and change in BP (morning BP minus evening BP) to determine the influence of SpO2 on BP. METHODS: Sixty-two volunteers (31 men and 31 women) aged 40-87 years (mean: 55.9 +/- 12 [SD] years) underwent measurement of SpO2 and heart rate with a ring-shaped pulse oximeter during sleep at home. Evening BP and morning BP were measured by automatic BP recorder. Subjects that were classified as having high SpO2 (mean nocturnal SpO2 >or= 95%; n = 23, 10 men and 13 women; mean age: 53.2 +/- 12 years) or low SpO2 (mean nocturnal SpO2 < 94%; n = 21, 12 men and 9 women; mean age: 58.7 +/- 13 years) were compared. The relation between mean nocturnal SpO2 and morning BP and the relation between mean nocturnal SpO2 and change in BP were investigated. RESULTS: There was a significant negative correlation between mean nocturnal SpO2 and morning systolic BP (SBP; r = -0.50, p < 0.01) and between mean nocturnal SpO2 and morning diastolic BP (DBP; r = -0.37, p < 0.01). A significant negative correlation between mean nocturnal SpO2 and change in SBP was observed (r = -0.57, p < 0.01). Morning BP was significantly higher in the low nocturnal SpO2 group than in the high nocturnal SpO2 group (p < 0.001). CONCLUSION: The increase in morning BP from evening BP was significantly greater in subjects with a low nocturnal SpO2. The decrease in SpO2 during sleep may affect morning BP rise.

Adult↗
PubMed2006

Effects of pulse-synchronized massage with air cuffs on peripheral blood flow and autonomic nervous system.

BACKGROUND: There are almost no reports on the physiological effects of the various electric massage devices available on the market. This report describes the effects on peripheral vascular circulation and autonomic-nervous system activity of a pulse-synchronized air-massage (PS-AM) device in which cuffs apply air pressure cyclically to the lower limbs only during the cardiac diastolic phase. METHODS AND RESULTS: The PS-AM device consists of a main unit with a pulse-wave detector that uses the pulse-wave to activate an air pump only during the cardiac diastolic phase. Pressure is applied sequentially from the feet to the thighs by 4 pairs of cuffs attached to the main unit. The study was carried out on 55 volunteers (19 males, 36 females). A laser Doppler flow-meter attached to the subjects' toes was used to measure blood flow (BF), while ECG, blood pressure and cardiac autonomic nerve activity [parasympathetic nerve activity (high-frequency component (HF))] were measured by a multibiomedical recorder (TM2425). The measurements were made for a total of 45 min consisting of three 15-min periods: before massage, during PS-AM, and after massage. BF increased 139+/-33 (SD) % in males and 154+/-44% in females during PS-AM, with a significant correlation being observed between BF and HF during PS-AM (p<0.01). CONCLUSIONS: PS-AM significantly increased peripheral vascular BF in the lower extremities, a change that may affect venous return and cardiac parasympathetic nerve activity.

Adult↗
PubMed2006

Estimation of base blood pressure by using a new device in the outpatient clinic.

Direct measurement of intra-arterial blood pressure (BP) for 24-h provides approximately 100,000 values that vary enormously, but each (BPi) can be expressed by the equation BPi = BP0 + DeltaBPi (BP0, base BP; DeltaBPi, BP increment, i=1, 2, ..., 100 x 10(3)). About 20% of outpatients with hypertension exhibit white-coat hypertension (WCH). In such patients, DeltaBPc (i = c; c, time at the clinic) is surmised to be large. A method for explaining the physiological factors in DeltaBPc and the estimation of base BP in the outpatient clinic is important. This study addresses this issue. A total of 293 subjects were divided into four groups: 1) WCH group, 45 individuals (office BP > or = 140/90 mmHg and 24-h indirect BP < 125/80 mmHg); 2) normotensive (NT) group, 84 controls matched for age and sex; 3) WHO-I group, 95 hypertensive patients with WHO stage I (office BP > or = 140/90 mmHg and 24-h BP > or = 125/80 mmHg); and 4) WHO-II group, 69 hypertensive patients with WHO stage II. Their BPc and heart rate (HR; HRc, clinic HR) values were measured by a BP-ECG monitoring device in the outpatient clinic. Power-spectral analysis was used to obtain the ratio between the low-frequency component (LF) and high-frequency component (HF) of ECG-RR variability (LF/HF = LH). Twenty-four-hour indirect BP (and BP0) and base HR (HR0) were measured by a portable device (TM2425) at 30-min intervals. Then, DeltaBPc (= BPc - BP0) was estimated by performing linear multivariate analysis applying the model equation DeltaBPc = (BPc -alphaLH)(1-betaHR0/HRc) + epsilon to the above variables (alpha and beta, constant values; epsilon, error). This model equation made it possible to estimate BP0 (and DeltaBPc) with a high coefficient of correlation (r > or = 0.85, mean of error less than 0.82 +/- 5.9 mmHg). The predictive accuracy for discrimination between WCH and sustained hypertension (WHO-I and WHO-II groups) by this equation was 88%. The new DeltaBP-estimation device (BP-ECG monitor) enabled us to infer BP0 and is therefore useful in estimating WCH in the outpatient clinic.

Adult↗
PubMed2006

Analysis of a long-term discrepancy in drug-targeted genes in plasma HIV-1 RNA and PBMC HIV-1 DNA in the same patient.

Drug-resistance genotypes were investigated in a patient under treatment with anti-HIV drugs. Since the drug resistance-associated mutations in plasma HIV-1 RNA and proviral DNA in peripheral blood mononuclear cells (PBMCs) were inconsistent, changes were followed over time, and the discrepancy was shown to persist for a long period. In plasma HIV-1 RNA, D67N, K70R, T215Y, and Y188L were present in the reverse transcriptase (RT) region, and two primary mutations, I84V and L90M, were noted in the protease (Pro) region. In contrast, in proviral DNA, no drug resistance-associated mutations were found in the RT region, and mutations such as L90L/M were only infrequently present in the Pro region. This situation persisted for more than 3 years. In addition, sequencing analysis of the V3 loop in the envelope gene showed that non-syncytium-inducing/macrophage-tropic viruses contribute to acquisition of drug resistance. In this study, drug-resistant viruses were produced primarily at macrophages, and drug-sensitive viruses were maintained in PBMCs as a reservoir.

Amino Acid Sequence↗
PubMed2006

[A novel method for the self-collection of blood, "thenar lancing phlebotomy" and investigation of its accuracy].

"Thenar lancing phlebotomy" is a novel method for the self-collection of blood using a special phlebotomy device for the thenar and a self-collection blood kit. The thenar is punctured with a special lancet, the vein is subjected to automatic avascularization at the wrist and at the same time, a small centrifuge tube, attached to the suction cylinder of the device, is applied to the puncture and the blood is collected by suction. The small centrifuge tube containing the whole blood is centrifuged with a portable centrifugal separator to obtain plasma. In comparison with conventional finger prick phlebotomy, there is less pain and sufficient blood may be obtained. To investigate the accuracy of the method, we collected blood from the antecubital vein of 140 subjects and thenar lancing phlebotomy was simultaneously carried out on the same 140 subjects. The results of many blood tests currently included in medical check-ups were almost identical in the blood samples of both groups, suggesting that this method can be utilized in medical check-ups using self-collected blood sampies.

Female↗
PubMed2005

Influence of weather on emergency transport events coded as stroke: population-based study in Japan.

Studying the relation between incidence of stroke and weather is difficult because it requires large-scale community-based data collection. Despite the lack of strong evidence that weather conditions influence stroke incidence, many clinicians feel that meteorological conditions influence the onset of stroke. This study examined whether emergency events related to stroke are influenced by meteorological factors and was based on computerized records of emergency medical transport services in a Japanese city during the period January 1992-December 2003. A total of 53,585 patients transported for an event coded as stroke were analyzed in relation to meteorological factors such as temperature, humidity, and barometric pressure. Poisson regression analysis was applied to clarify the influence of daily meteorological conditions on the daily incidence of emergency transport due to events coded as stroke. Ordinary least squares regression analysis was used to evaluate the influence of weather, defined as the combination of meteorological parameters, on the occurrence of emergency transport due to events coded as stroke. Daily mean ambient temperature and daily mean relative humidity showed a statistically significant negative effect on the incidence of the emergency transport events for both men and women (P<0.001). Daily mean barometric pressure was not significantly related to these events. The occurrence of a holiday was negatively related to the incidence (P<0.001). Dry weather and cool weather were likely to shift the circadian curve of the incidence upward. Thus, occurrence of emergency transport due to events coded as stroke is likely to be associated with weather conditions.

Aged↗
PubMed2005

Evaluation of out-of-hospital cardiopulmonary resuscitation with resuscitative drugs: a prospective comparative study in Japan.

OBJECTIVE: This study aimed at evaluating two emergency medical service systems, one in which emergency life-saving technicians (ELSTs) are allowed to administer epinephrine (adrenaline) to patients with out-of-hospital cardiac arrest and one in which ELSTs are allowed to administer epinephrine, lidocaine, and atropine. METHODS: A modified, prospective community health trial was conducted from April 1 to October 31, 2003. Areas served by physician-manned ambulances, where out-of-hospital cardiopulmonary resuscitation (CPR) was performed with resuscitative drugs (experimental areas), were compared to areas served by ELST-manned ambulances, where resuscitative drugs were not administered outside the hospital (reference areas). The sequence of emergency procedures performed in the experimental areas was divided into three phases. Phase I included administration of epinephrine, which simulated administration of epinephrine by ELSTs. Phase II started with the use of lidocaine or atropine. Phases I and II simulated administration of epinephrine, lidocaine, and atropine by ELSTs. Phase III began with administration of another drug. Outcomes, resuscitation rates and 1-month survival rates were determined, and differences between the two types of areas were analyzed. RESULTS: For non-traumatic cardiac arrest, outcomes through phase II in the experimental areas were significantly better than those in the reference areas. Phase I-only outcomes in the experimental areas were better, but not significantly better, than those in the reference areas. CONCLUSION: Use of resuscitative drugs for non-traumatic prehospital CPR appears to be effective in terms of resuscitation rates and 1-month survival rates.

Aged↗
PubMed2005

A contingent valuation study of the appropriate user price for ambulance service.

BACKGROUND: In Japan, anyone can use an ambulance free of charge, but this policy may encourage unnecessary ambulance use. OBJECTIVES: To determine the user price that would reduce unnecessary ambulance use, without discouraging medically necessary ambulance use. METHODS: The study was conducted by means of a three-part self-administered questionnaire. The first part consisted of questions covering demographic variables such as respondent age, gender, family structure, and pretax annual household income. The second part was made up of contingent valuation questions on ambulance use. Respondents were presented hypothetical situations and prices and then asked whether they would call an ambulance. The last part consisted of general questions pertaining to the city ambulance system. Answers to the hypothetical questions were analyzed in relation to demographic characteristics of the respondents. RESULTS: A total of 2,029 out of 3,363 recipients completed the questionnaire (response rate, 60.3%). Analysis of the responses indicated that the demand for ambulance service in serious situations is inelastic with respect to price, whereas the demand for ambulance service in nonserious situations is fairly elastic with respect to price. These data showed that a user charge of 190 dollars (20,000 yen) may be an acceptable price, i.e., the price that will reduce the number of ambulance calls by persons with nonserious conditions, but not by persons with serious conditions. CONCLUSIONS: Introducing a user charge for ambulance service may improve efficiency of the service operation.

Ambulances↗
PubMed2005

Relation between 24-h heart rate variability and blood pressure fluctuation during exercise in stroke patients.

BACKGROUND: In some stroke patients blood pressure (BP) fluctuates extensively during medical rehabilitation, so the present study investigated the influence of autonomic nervous dysfunction on the change in BP during exercise. METHODS AND RESULTS: The subjects consisted of 55 stroke inpatients (males, 29; mean age, 58.8 years old; ischemic/hemorrhagic etiology, 30/25) who were admitted to the Stroke Center within 2 weeks of their first stroke. The control group consisted of 15 age-matched healthy volunteers. The 24-h heart rate (HR) variability (HRV) and BP variability (BPV) were examined, and then the increase and recovery of BP and HR were measured during bicycle ergometer exercise at 4 METs. Components of 24-h HRV (low-frequency power (LF), high-frequency power (HF), LF/HF, and asleep-awake ratio of LF/HF (LF/HF(d-n)) were lower (p < 0.01) and BPV was greater in the stroke group (p < 0.05) than in the control group. There was a negative correlation between BP change during exercise and LF/HF or LF/HF(d-n) (r = -0.43 or r = -0.58, p < 0.01), and a greater increase in systolic BP (102 +/-9.8 mmHg, n = 7) during exercise was observed in stroke patients with lower LF/HF(d-n) (< or = 1.0). CONCLUSIONS: Lower HRV in stroke patients may relate to an increase in BP during exercise. HRV is useful for estimating the risk during medical rehabilitation.

Aged↗
PubMed2005

Effects of losartan and amlodipine on urinary albumin excretion and ambulatory blood pressure in hypertensive type 2 diabetic patients with overt nephropathy.

OBJECTIVE: Few studies have assessed whether 24-h blood pressure control induced by antihypertensive agents improves macroalbuminuria in hypertensive type 2 diabetic patients with overt nephropathy. We evaluated the effects of losartan and amlodipine on 24-h blood pressure, autonomic nervous activity, and albuminuria in these patients. RESEARCH DESIGN AND METHODS: In this open-label, parallel-prospective, randomized study, 44 patients were treated with losartan and 43 with amlodipine for a 12-week titration phase and a maintenance phase for a maximum of 12 weeks. Twenty-four-hour blood pressure and urinary albumin excretion were measured before and during treatment. Simultaneously, power spectral analysis of heart rate was performed to evaluate low frequency (LF) and high frequency (HF) components and LF-to-HF ratios as an index of sympathovagal balance. RESULTS: Losartan decreased (P < 0.001) mean blood pressure from 162/91 to 150/82 mmHg during daytime and from 146/82 to 137/74 mmHg during nighttime (systolic/diastolic). Amlodipine also decreased (P < 0.001) blood pressure from 159/90 to 147/82 mmHg during daytime and from 143/81 to 131/72 mmHg during nighttime. LF and HF components and nighttime-to-daytime ratios for the LF-to-HF ratios did not differ during treatment in two groups, showing no changes in the diurnal autonomic nervous rhythm. Losartan decreased (P < 0.001) 24-h urinary albumin excretion from 810 mg/day (95% CI 780-1,140) to 570 (510-910). Amlodipine, however, did not decrease (P = 0.893) albuminuria (790 mg/day [780-1,170] vs.790 [710-1,260]). CONCLUSIONS: These results suggest that in type 2 diabetes with overt nephropathy, 24-h blood pressure regulation alone is inadequate to reduce macroalbuminuria and additional effects of losartan are crucial for antiproteinuric action.

Adult↗
PubMed2004

Perindopril effects on ambulatory blood pressure: relation to sympathetic nervous activity in subjects with diabetic nephropathy.

BACKGROUND: Few studies have reported the effect of angiotensin-converting enzyme inhibitors on 24-h blood pressure (BP) and regulation of sympathetic nervous activity in hypertensive patients with diabetic nephropathy. Using ambulatory BP monitoring (ABPM) devices equipped with spectral analysis of heart rate variability, we assessed the effects of perindopril on 24-h BP and autonomic nervous activity in these patients. METHODS: Thirty-four hypertensive patients with non-insulin-dependent diabetic nephropathy underwent ABPM before and after treatment with perindopril (final dose: 4.9 +/- 1.8 mg/d). Simultaneously, spectral analysis was performed to calculate the high frequency components (HF) as a marker of parasympathetic nervous activity, and the low frequency components (LF)/HF ratios as an index of the sympathovagal balance. RESULTS: Perindopril significantly and equally decreased the waking and sleeping BP in the diabetic patients. During the sleeping period, the magnitude of change of mean BP induced by perindopril correlated inversely with the sleeping/waking ratio of mean BP before treatment. However, there was no correlation between these parameters during the waking period. Perindopril decreased both waking and sleeping LF/HF ratios, although no differences in HF components were observed between before and after treatment. CONCLUSIONS: In patients with diabetic nephropathy, perindopril decreased 24-h BP. Spectral analysis suggested that this finding was partially related to inhibited sympathetic nervous activity. During sleeping periods, the BP-lowering effect of perindopril was more pronounced in patients showing no nocturnal decrease in BP. Perindopril may be a potent antihypertensive agent to reduce increased nocturnal BP, a risk factor of target organ damage in these patients.

Adult↗
PubMed2004

Randomized controlled trial of sour milk on blood pressure in borderline hypertensive men.

BACKGROUND: A double-blind randomized controlled trial was carried out to assess the effect of sour milk, containing two tripeptides (valine-proline-proline and isoleucine-proline-proline), on blood pressure (BP). METHODS: A total of 46 borderline hypertensive men aged 23 to 59 years were recruited at their workplace for this trial. Subjects were randomly allocated into two groups; sour milk drink group (S-group, n = 23) and placebo (acidified milk) drink group (P-group, n = 23) for 4 weeks. Blood pressure was measured twice at each occasion by a physician, at the health center of the company, with a mercury at baseline, 2 and 4 weeks. Statistical analysis was performed by SPSS 10.0J. RESULTS: The S-group and P-group showed no significant difference in baseline systolic BP (mean [SD], S: 147.6 [9.6], P: 145.3 [13.0]) or diastolic BP (S: 95.3 [9.9], P: 91.5 [9.6]). In the S-group, change in systolic BP at 2 and 4 weeks were -4.3 mm Hg (95% confidence interval [CI] -8.3 to -0.4; P = .032) and -5.2 mm Hg (95% CI -10.1 to -0.3; P = .039), both statistically significant. Diastolic BP showed change from -1.7 mm Hg (95% CI -5.4 to 2.0) at 2 weeks and -2.0 (95% CI -5.4 to 1.5) at 4 weeks, respectively. In the P-group, change in systolic BP were -0.5 (95% CI -5.8 to 4.8) at 2 weeks and -3.7 (95% CI -8.3 to 0.9) and change in diastolic BP were -0.6 (95% CI -4.7 to 3.6) and -0.3 (95% CI -3.9 to 3.3), which were not statistically significant. CONCLUSIONS: This trial demonstrated the beneficial effect of sour milk on BP in borderline hypertensive men who were not taking antihypertensive medication.

Adult↗
PubMed2004

Relationships between diurnal blood pressure variation, physical activity, and health-related QOL.

The aim of this study is to clarify the associations between diurnal blood pressure variation, physical activity and health-related quality of life (HRQOL). Ninety-seven volunteers, including 52 hypertensive patients and 45 healthy subjects (average age, 48 years) participated in this study. Twenty-four hour ambulatory blood pressure and heart rate variability were measured using TM2425 (A&D Co). Physical activity was measured using actigraphy, and HRQOL was assessed by a Medical Outcome Study Short-Forum 36-Item Health Survey (SF-36). Awake mean physical activity positively correlated with the nocturnal dip in systolic blood pressure (SBP) (r = 0.242, p < 0.02) and diastolic blood pressure (DBP) (r = 0.219, p < 0.04). The score of physical functioning positively correlated with awake mean physical activity (r = 0.265, p < 0.02). The score of role-emotional also correlated with awake mean physical activity (r = 0.269, p = 0.01). Using multiple regression analysis, the nocturnal dip in SBP was found to be correlated with awake and sleep mean physical activities (p < 0.05, p < 0.05, respectively). In conclusion, physical activity is associated with the nocturnal dip in blood pressure. Moreover, physical activity correlates with some of the factors of HRQOL.

Adult↗
PubMed2004

Relation between white blood cell counts and myocardial reperfusion in patients with recanalized anterior acute myocardial infarction.

BACKGROUND: The clinical significance of the white blood cell (WBC) count on admission in relation to the duration of ischemia in acute myocardial infarction (AMI) remains unclear. METHODS AND RESULTS: The relationship of the WBC count on admission to myocardial reperfusion was examined in 135 patients with recanalization of an anterior AMI within 6 h of symptom onset. Patients were classified according to the WBC count on admission: Group L (n=75), WBC count <12,000 cells/mm(3) and group H (n=60), WBC count >or=12,000 cells/mm(3). Peak creatine kinase (CK) was higher and impaired myocardial reperfusion, defined as a myocardial blush grade of 0/1, was more frequent in group H than in group L. Among the patients in group H, those with early ( 3 h) recanalization; however, peak CK and the incidence of impaired myocardial reperfusion were similar in these subgroups of patients. Multivariate analysis showed that WBC count >or=12,000 cells/mm(3) on admission was an independent predictor of impaired myocardial reperfusion in patients with early recanalization (odds ratio 7.9, p=0.04), but not in those with late recanalization. CONCLUSIONS: A higher WBC count may be associated with progression of myocardial damage after recanalization in patients with early recanalization of an anterior AMI.

Aged↗