Biomedical subjects

K Nishibata

Publications and source records attributed to K Nishibata.

16 recordsLinked to original sources

PubMed1999

Oxygen uptake efficiency slope as a useful measure of cardiorespiratory functional reserve in adult cardiac patients.

In this study we aimed to elucidate the validity and usefulness of the oxygen uptake efficiency slope (OUES) in the evaluation of adult cardiac patients. Cardiopulmonary exercise tests were performed on a treadmill by 50 adult patients with chronic heart failure. The OUES was calculated from data for the first 75%, 90%, and 100% of exercise duration. The OUES is derived from the following equation: VO(2)=ax logV(E)+b, where VO(2) is oxygen uptake (ml/kg/min), V(E) is minute ventilation (l/kg/min), and the constant "a" represents OUES. We also determined the ventilatory anaerobic threshold (VAT). The correlation coefficient of the logarithmic curve-fitting model was [mean (SD)] 0.986 (0.009). The OUES could be used to discriminate effectively between New York Heart Association functional classes (P < 0.001). OUES and maximum VO(2) were significantly correlated (r=0.78, P < 0.01). Agreement between the OUES values for the first 90%, 75%, and 100% of the exercise was excellent (intraclass correlation coefficient = 0.99). Our results suggest that OUES is applicable to adult cardiac patients as an objective, effort-independent estimation of cardiorespiratory functional reserve.

Aged↗

PubMed1999

Role of the oxygen uptake efficiency slope in evaluating exercise tolerance.

OBJECTIVE: To investigate the interprotocol agreement of oxygen uptake efficiency slope (OUES). METHODS: 16 Japanese children and adolescents (10 boys and six girls) underwent two sessions of maximal exercise testing according to the following two treadmill protocols: the standard Bruce protocol and the rapidly increasing staged (RIS) protocol. Maximal oxygen uptake (VO2max), the ventilatory anaerobic threshold (VAT), and the OUES were obtained from the gas analysis data. Agreement between the protocols was tested by means of the Bland-Altman method. RESULTS: Interprotocol agreement was excellent for the OUES (limit of agreement, -18% to 17% of the mean value), slightly less good for VO2max (limit of agreement, -20% to 24% of the mean value), and poor for the VAT (limit of agreement, -31% to 31% of the mean value). CONCLUSION: These results confirm the clinical usefulness of the OUES as a measure of evaluating exercise tolerance in the paediatric population.

Adolescent↗

PubMed1998

Ventilatory control during exercise in normal children.

We investigated the relation between age and respiratory control during exercise in 80 children aged 6.4-17.6 y (42 male, age, 11.6 +/- 3.3 y; body weight, 41.3 +/- 14.7 kg; and 38 female, age, 12.6 +/- 2.7 y; body weight, 42.5 +/- 9.3 kg). Exercise tests were performed on a treadmill after a standard symptom-limited Bruce protocol. Data were analyzed separately for boys and girls. At rest and at peak exercise, the ratio of minute ventilation to carbon dioxide production (VE/VCO2), the ratio of effective alveolar ventilation to carbon dioxide production (VA/VCO2), the ratio of pulmonary dead space to tidal volume (Vd/Vt), and arterial PCO2 (PaCO2) were not correlated with age. At the exercise intensity of ventilatory anaerobic threshold, the PaCO2 increased, and the VA/VCO2 decreased, significantly with age, whereas the Vd/Vt was not related to age. Linear regression analysis demonstrated that the slope of the relationship between VE and VCO2 (deltaVE/deltaVCO2) and the slope of the relationship between VA and VCO2 (deltaVA/deltaVCO2) decreased with age. There were no gender differences in the regression slopes and the intercepts of the relationships. Results show that younger children breathe more during exercise to eliminate a given amount of CO2 to keep PaCO2 set point slightly but significantly lower than older children. This age dependence must be considered in investigating ventilatory control during exercise in children.

Adolescent↗

PubMed1998

[Toxicity study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na) (2). 4-week repeated dose intravenous toxicity study in rats with 4-week recovery test].

A 4-week repeated dose toxicity study with 4-week recovery test of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na), a novel neutrophil elastase inhibitor, was conducted in Sprague-Dawley (SD) rats. The rats of both sexes were administered ONO-5046.Na intravenously at a daily dose of 0 (vehicle control and saline control), 18.75, 37.5, 75 or 150 mg/kg. ONO-5046.Na did not affect signs, body weight, food consumption, ophthalmology, urinalysis, hematology, blood chemistry, organ weights, necropsy or histopathology at any dose. These results indicate that the NOAEL of (ONO-5046.Na in rats is 150 mg/kg/day for both sexes in this study.

Animals↗

PubMed1998

[Toxicity study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na) (3). 4-week repeated dose intravenous toxicity study in dogs with 4-week recovery test].

4-week repeated dose toxicity study with 4-week recovery test of sodium N-[2-[4-(2, 2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na), a novel neutrophil elastase inhibitor, was conducted in beagle dogs. The dogs of both sexes were administered ONO-5046.Na intravenously at a daily dose of 0 (vehicle control), 7.5, 15 or 30 mg/kg. In the 15 mg/kg female group and the 30 mg/kg male and female groups, transient hypoactivity and ataxic gait were observed. It is considered that these symptoms were attributed to the pharmacological effect of ONO-5046.Na. Also, in the 30 mg/kg male and female groups, erythrocyte, hematocrit and hemoglobin were decreased. In the 30 mg/kg male group, lung weight was increased. However, histopathological examination revealed there were no changes in any organs including the lungs. There were no treatment-related changes in body weights, food consumption, ophthalmology, occult blood in feces, urinalysis, blood chemistry, electrocardiography, blood pressure, temperature, pulse rate, hepatic and renal function or necropsy. These results indicate that the NOAEL of ONO-5046.Na in dogs in 15 mg/kg/day for both sexes in this study.

Animals↗

PubMed1998

[Toxicity study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na) (4). 6-month repeated dose intravenous toxicity study in rats with 1-month recovery test].

A 6-month repeated dose toxicity study with 1-month recovery test of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na), a novel neutrophil elastase inhibitor, was conducted in Sprague-Dawley (SD) rats. The rats of both sexes were administered ONO-5046.Na intravenously at a daily dose of 0 (vehicle control), 18.75, 37.5 or 75 mg/kg. ONO-5046.Na did not affect clinical signs, body weight, food consumption, opthalmology, urinalysis, hematology, blood chemistry, organ weight, necropsy or histopathology at any dose. These results indicate that the NOAEL of ONO-5046.Na in rats is 75 mg/kg/day for both sexes in this study.

Animals↗

PubMed1997

Analysis of heart rate variability demonstrates effects of development on vagal modulation of heart rate in healthy children.

OBJECTIVES: Analysis of heart rate variability (HRV) has been found to be a useful method of assessing cardiovascular autonomic control, but normal values for standard HRV measures in children have not been established. We analyzed HRV in 60 healthy children aged 3 to 15 years to determine normal values and to assess the effects of development on cardiac autonomic control with the use of ambulatory electrocardiographic monitoring. RESULTS: The high-frequency (HF) component, an index of cardiac autonomic tone, increased significantly with age from 3 to 6 years (p < 0.01) and decreased with age from 6 to 15 years (p < 0.01), and the magnitude of HF correlated significantly with the R-R intervals. Thus the changes in cardiac autonomic tone could be described as a simple equation using age and heart rate. CONCLUSIONS: We present normal values and changes in the cardiac autonomic system during childhood after HRV analysis, which could lead to a better understanding and treatment of cardiac disease in children.

Adolescent↗

PubMed1997

[Toxicity studies of landiolol hydrochloride (ONO-1101) (2). 4-week repeated dose intravenous toxicity study in rats with 4-week recovery test].

4-week repeated dose toxicity study with 4-week recovery test of landiolol hydrochloride (ONO-1101), a novel ultra short acting beta-blocker, was conducted in Sprague-Dawley (SD) rats. ONO-1101 was administered intravenously to rats of both sexes at a dose level of 0 (control), 12.5, 25, 50 or 100 mg/kg/day. In the 100 mg/kg/day group, bradypnea or dyspnea was seen in all animals, pale in ear, eye and foot, tremor, reddish lacrimation and loss of righting reflex were also observed in some animals right after administration, and then those signs disappeared within 1 min after administration. During the treatment period, 3/20 animals of each sex in the 100 mg/kg/day showed clonic convulsion and died within 2 min after administration. No clinical changes were seen in the 50 mg/kg/day group or lower. Histopathological findings showed atrophy of the submaxillary gland in females and vessel-wall thickening and perivascular fibrosis of the injection site (tail) in both sexes at 100 mg/kg/day, however those changes were reversible. ONO-1101 did not effect on body weight, food consumption, ophthalmology, urinalysis, hematology, blood chemistry, organ weights or necropsy at any doses. These results indicate that the no-adverse-effect level of ONO-1101 in rats is 50 mg/kg/day for both sexes in this study.

Adrenergic beta-Antagonists↗

PubMed1997

Cardiorespiratory response to exercise in patients with exercise-induced bronchial obstruction.

OBJECTIVE: To document the characteristics of the ventilatory response to exercise in patients with exercise-induced bronchial obstruction (EIB). EXPERIMENTAL DESIGN: Comparative study during the period between December 1993 and March 1994. SETTING: Ambulatory care in Ohgaki Municipal Hospital. SUBJECTS AND METHOD: We evaluated 11 children with EIB. Each subject under went symptom-limited cardiopulmonary treadmill exercise testing (Bruce protocol). RESULTS: Patients with EIB showed a significantly lower peak oxygen consumption (peak VO2) than the control subjects. Three patients with EIB developed relative hypoventilation during incremental exercise: an increase in end-tidal carbon dioxide partial pressure (PETCO2) and a decrease in VE/VCO2 were observed at the end-stage of exercise testing. CONCLUSIONS: These findings demonstrate that some patients with EIB develop bronchoconstriction during exercise.

Adolescent↗

PubMed1996

Oxygen uptake efficiency slope: a new index of cardiorespiratory functional reserve derived from the relation between oxygen uptake and minute ventilation during incremental exercise.

OBJECTIVES: We investigated the usefulness of a new variable, oxygen uptake efficiency slope (OUES), as a submaximal measure of cardiorespiratory functional reserve. The OUES is derived from the relation between oxygen uptake (Vo2 [ml/min]) and minute ventilation (VE [liters/min]) during incremental exercise and is determined by VO2 = a log VE + b, where a = OUES, which shows the effectiveness of Vo2. BACKGROUND: Maximal oxygen uptake (VO2max) is effort dependent. There is no standard submaximal measurement of cardiorespiratory reserve that provides generally acceptable results. METHODS: Exercise tests, following a standard Bruce protocol, were performed on a treadmill by 108 patients with heart disease and 36 normal volunteers. Expired gas was continuously analyzed. The OUES was calculated from data of the first 75%, 90% and 100% of exercise duration. We also determined the following submaximal variables: the ventilatory anaerobic threshold (VAT), the slope of the regression line of the minute ventilation-carbon dioxide production relation (VE-VCO2 slope) and the extrapolated maximal oxygen consumption (EMOC). We analyzed the relation of OUES and other submaximal variables against VO2max and examined the effects of submaximal exercise on OUES. RESULTS: The correlation coefficient of the logarithmic curve-fitting model was 0.978 +/- 0.016 (mean +/- SD). The OUES and VO2max had a significant correlation (r = 0.941, p < 0.0001). The correlation between VO2max and OUES was stronger than that between VO2max and VAT, the VE-VCO2 slope or EMOC. The OUES values for 100% and 90% of exercise were not different from each other (at an alpha value of 0.05 and treatment effect of 170, the power of the test [1-beta] was 0.90); OUES for 75% of exercise was slightly lower (3.5%). CONCLUSIONS: Our results suggest that OUES may provide an objective, effort-independent estimation of cardiorespiratory functional reserve that is related both to pulmonary dead space and to metabolic acidosis.

Adolescent↗

PubMed1996

Oxygen intake efficiency slope: a new index of cardiorespiratory functional reserve derived from the relationship between oxygen consumption and minute ventilation during incremental exercise.

We investigated the usefulness of the oxygen intake efficiency slope (OIES) as a submaximal measure of cardiorespiratory functional reserve. OIES was derived from the relationship between oxygen consumption (VO2; ml/min) and minute ventilation (VE; l/min) during incremental exercise, which was determined by the following equation: VO2 = a logVE + b, where "a" represents OIES, which shows the effectiveness of ventilation. Maximal oxygen consumption (VO2max) is effort-dependent. There is no standard submaximal measurement of cardiorespiratory reserve that provides generally acceptable results. Exercise tests were performed by 17 normal volunteers on an ergometer using a symptom-limited Ramp protocol. Expired gas was continuously analyzed. OIES was calculated using the first 75%, 90%, and 100% of exercise data. We also determined the following submaximal parameters: the ventilatory anaerobic threshold (VAT), the slope of the minute ventilation-carbon dioxide production relationship (VE-VCO2 slope), and the extrapolated maximal oxygen consumption (EMOC). We analyzed the relationship between OIES, other submaximal parameters and VO2max, and examined the effects of submaximal exercise on OIES. The correlation coefficient of the logarithmic curve-fitting model was 0.991 +/- 0.006. OIES and VO2max were significantly correlated (r = 0.966, p < 0.0001). The correlation between OIES and VO2max was stronger than the correlation between VO2max and VAT, the VE-VCO2 slope and EMOC. OIES values for 100% and 90% of exercise were identical; OIES for 75% of exercise was slightly lower (3%). Our results suggested that OIES may provide an objective, effort-independent estimation of cardiorespiratory functional reserve.

Adolescent↗

PubMed1996

[An operative case of bilateral partial anomalous pulmonary venous return using a direct anastomosis between the right atrial appendage and the superior vena cava].

We have experienced a case of bilateral partial anomalous pulmonary venous return without atrial septal defect. Right upper pulmonary vein returned to the superior vena cava and left upper pulmonary vein returned to the left brachiocephalic vein. This type of bilateral partial anomalous pulmonary venous return was extremely rare, and only 4 such cases have been reported in the Japanese literature. The patient, aged 3 years and 11 months, was successfully operated on, using a direct anastomosis between the right atrial appendage and the superior vena cava. This procedure is considered to be advantageous because both this right atriotomy line and suture line avoid injury of the sinus node and the sinuatrial node artery and no foreign material is used. A decrease in postoperative arrhythmia can also be expected from this procedure.

Anastomosis, Surgical↗

PubMed1995

Comparison of casual blood pressure and twenty-four-hour ambulatory blood pressure in high school students.

OBJECTIVE: To perform ambulatory blood pressure monitoring (ABPM) in high school students and to compare the 24-hour values with casual blood pressure (BP). METHODS: Ambulatory BP monitoring was carried out in 190 high school students, 15 or 16 years of age, with elevated casual BP during the first examination at school for hypertension; 66 had elevated casual BP at both the first and the second examinations (group H1), and 124 students were normotensive at the second examination (group H2). Sixty-two students who were consistently normotensive served as control subjects (group N). Average BPs for the 24-hour period, the awake period (10 AM to 10 PM), and the sleeping period (1 AM to 6 AM) were calculated. RESULTS: Average BP for each period was significantly higher in group H1 than in group N. Average BP in group H2 for these periods was intermediate between those of group H1 and of group N. The casual BP had a significant positive correlation with the average BP during the awake period (r = 0.55, p < 0.01 for systolic BP; r = 0.37, p < 0.01 for diastolic BP). In most subjects the casual BP readings were higher than BP during ABPM. CONCLUSIONS: Casual BP measurements correlated with 24-hour BP, but they tended to be higher than the measurements obtained during 24-hour ABPM.

Adolescent↗

PubMed1995

Long-term follow-up of idiopathic ventricular arrhythmias in otherwise normal children.

Clinical characteristics and long-term prognosis of 163 children with ventricular arrhythmias without underlying heart diseases (78 with ventricular premature contractions (VPC group), 39 with ventricular couplets (CPLT group), and 46 with ventricular tachycardia (VT group)) were studied by Holter electrocardiographic monitoring (Holter ECG) and treadmill exercise testing. The age of the subjects at the initial examination was 8.9 +/- 3.4 years in the VPC group, 9.9 +/- 3.5 years in CPLT group, and 9.4 +/- 3.1 years in the VT group. The duration of the follow-up was 71.7 +/- 32.1 months in the VPC group, 65.9 +/- 32.8 months in the CPLT group, and 84.0 +/- 31.9 months in the VT group. VPC's disappeared during the follow-up period in 22 (28%) of the 78 children in the VPC group. CPLT's disappeared in 15 (38%) and VPC's disappeared in 9 (23%) of the 39 children in the CPLT group. In the 46 children in the VT group, VT disappeared in 30 (65%), and VPC's disappeared in 17 (37%). One child (2%) in the VT group died of heart failure due to drug-resistant sustained VT. The mean time until the disappearance of VPC's in the 163 patients was estimated to be 115.2 +/- 4.3 months. The mean time until the disappearance of VT in the 46 children in the VT group was estimated to be 89.0 +/- 4.9 months. Multivariate analysis of prognostic factors related to the disappearance of VPC's indicated that nighttime VPC's were significantly more likely to disappear (p = 0.018), and that symptomatic VT was significantly more likely to disappear than asymptomatic VT (p = 0.032), probably because more symptomatic cases received antiarrhythmic therapy. Ventricular arrhythmias in children without underlying diseases often disappeared, and the prognosis was generally favorable. However, appropriate treatment and follow-up were required in children with sustained VT, symptomatic VT, or VT with a high rate of VT.

Adolescent↗

PubMed1993

Investigation of clinical characteristics of ventricular extrasystole in children--using two dimensional RR interval plotting method.

Eighty-three children were monitored by Holter electrocardiography for ventricular premature contraction (VPC), and the relationship between the preceding RR interval and the coupling interval was plotted using a two-dimensional RR interval plotting method. With this method, the slope (a) and standard deviation (SD) of the linear regression (Y = aX+b) were determined. These parameters were used to classify the patients into one of two types: a fixed type (SD < 40 msec, a < 0.2) and an unfixed type. The unfixed type was further divided into four subtypes, based on the plotted morphology: scattered, dependent, biphasic, and intermediate. The relationships between the VPC origin, organic heart disease, ventricular tachycardia (VT) and parasystole were investigated in the five types. The fixed and dependent types comprised significantly greater proportions of the subjects with VPC of right ventricular origin than of subjects with VPC of left ventricular origin (fixed: 31/59 right VPC vs 4/24 left VPC, p < 0.005; dependent: 13/59 vs 1/24, p < 0.05). On the other hand, comparatively very few subjects of the scattered type showed right VPC (4/59 vs 18/24, p < 0.005). Finally, the biphasic and intermediate types were distributed fairly equally among the subjects with VPCs of right and left ventricular origin (biphasic: 5/59 vs 0/24, p = 0.31, intermediate: 6/59 vs 1/24, p = 0.67). Organic heart disease was present in 13 subjects (15.7% of total subjects), seven of whom were of the fixed type with right ventricular origin (22.6% of subjects of this type). VT was observed in 34 subjects, but was rare in the scattered type (2/22 subject, 9.1%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

Inhalation of low-dose nitric oxide to evaluate pulmonary vascular reactivity in children with congenital heart disease.

The objective of this study was to investigate the efficacy of low-dose nitric oxide (NO). The study used fifteen consecutive Japanese preoperative patients (7 males and 8 females) with congenital heart disease and pulmonary hyptertension (mean pulmonary arterial pressure >30 mmHg), 6 of these patients had Down's syndrome. Hemodynamic measurements were taken in room air, 100% oxygen, 5 and 40 parts per million NO (NO5 and NO40) by inhalation. The differences between two observations within the same group were determined by the two-tailed paired t-test. A pulmonary vascular resistance (Rp) regression curve was constructed by using linear regression analysis. The percentage change in pulmonary arterial pressure per systemic arterial pressure (Pp/Ps) with NO40 (Pp/Ps-40) exceeded that of Pp/Ps-5 (p < 0.0001). The percentage change for the Rp with NO40 (Rp-40) was larger than that for the Rp-5 (p = 0.0003). The percentage change of Pp/Ps-5 and that with oxygen were similar (p = 0.266). The relationship between Rp-5 and Rp-40 was linear. In conclusion, the effects of NO5 were equivalent to 100% oxygen but less than NO40. NO5 should initially be used to test pulmonary reactivity. If there is no response, patients should still be given NO40.

Administration, Inhalation↗