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Biomedical subjects

T Matoba

Publications and source records attributed to T Matoba.

At least 19 recordsLinked to original sources
PubMed1998

HPLC method for evaluation of the free radical-scavenging activity of foods by using 1,1-diphenyl-2-picrylhydrazyl.

An HPLC method for evaluation of the free radical-scavenging activity of foods by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) is reported. The activity was evaluated by measuring the decrease of DPPH detected at 517 nm. By using this novel method, we determined the free radical-scavenging activity of several antioxidants: ascorbic acid, alpha-tocopherol, Trolox, and cysteine. The results gave good correlation between the radical-scavenging activity determined by HPLC and by conventional colorimetry. This methodology was applied to determine the free radical-scavenging activity of 8 beverages. The activity of coffee was the highest, followed by red wine, green tea, oolong tea, black tea, rosé wine, white wine, and orange juice. The results well agree with those of previous reports. This method is expected to be useful for a simple and rapid determination of free radical-scavenging activity in colored foods, because coloring substances in foods do not interfere with the measurement.

Antioxidants↗
PubMed1998

Whole-body vibration suppresses gastric motility in healthy men.

The influence of whole-body vibration on gastric motility was investigated by using an electrogastrography (EGG) in seven healthy men. The EGG is usually referred to as a noninvasive technique of recording gastric myoelectrical activity by means of placing electrodes on the abdominal surface. Sinusoidal vertical vibration at each of 3 different frequencies (10 Hz, 20 Hz, 40 Hz) were randomly given to the subject seated on a platform of vibrator for 5 min. The vibration magnitude was kept at a constant of 2.0 msec-2 (r.m.s.) during operation. The mean dominant frequency of EGG at control period was prior to operation 3.3 cycles per min (cpm). During vibration exposure at 10 Hz, the peak of dominant frequency increased to 3.9 cpm, and the relative power of slow wave showed the statistically significant decrease (45.8%, p < 0.05). The mean relative power of slow wave which is composed of frequencies ranged from 2.0 to 5.0 cpm was 56.6% at control period. On the contrary the mean relative power of frequencies ranging from 5.0 to 9.0 cpm, tachygastria increased from 29.5% to 39.1%. These results suggest that the short-term exposure to whole-body vibration effects on the gastric myoelectrical activity.

Adult↗
PubMed1996

Angiotensin II type 2 receptor inhibits cell proliferation and activates tyrosine phosphatase.

The angiotensin II type 2 (AT2) receptor inhibits basic fibroblast growth factor-induced proliferation of R3T3 fibroblast cells and transiently stimulates a vanadate-sensitive phosphotyrosine phosphatase, strongly suggesting that AT2 is a mitogen inhibitor. We generated AT2 gene-null mice that showed increased blood pressure, indicating the hypotensive action of AT2. However, inhibition of renomedullary AT2 by selective antagonists, as reported by Sassard and associates, show that AT2 suppresses pressure natriuresis. Thus, both AT1 and AT2 work in the direction of sodium retention, suggesting a unique role for angiotensin II in the kidney in terms of blood pressure regulation and sodium metabolism.

Angiotensin II↗
PubMed1996

A revised cold water immersion test for assessing peripheral circulatory function.

To improve the conventional cold water immersion test for assessing peripheral circulatory function, the immersed area of the hand was changed in this study. Twenty-seven healthy medical students with a mean age of 24 years participated in the study. The cold water immersion tests were carried out using two methods (in 5 degree C water for 1 min), in which the immersed area was up to the metacarpophalangeal (MP) joints (hereafter, MP-method) which is a new method, or to the wrist (hereafter, W-method) which is a conventional method. The recovery of skin temperature, vibratory perception threshold and complaints of finger pain were determined during cold immersion tests with the two methods. The mean skin temperature for the MP-method after immersion recovered more quickly than that for the W-method. However, the time courses of recovering were parallel for the two methods. Significant differences were noted at 3 min, 5 min and 10 min after cessation of immersion. There was a significant positive correlation in the recovery rates at 5 min after immersion between the two methods (correlation coefficient = 0.65, p < 0.01). The mean vibratory thresholds for the W-method were higher than those for the MP-method, and the difference was significant (p < 0.01). All subjects preferred the MP-method to the W-method because there was less finger pain. These results indicate that the MP-method, immersion up to the MP joint of a hand, for assessing peripheral circulatory function is better than the W-method.

Adult↗
PubMed1995

Application of Stockholm criteria to patients with hand-arm vibration syndrome in a follow-up study.

We applied Stockholm criterion to patients with hand-arm vibration syndrome (HAVS) for assessing the therapeutic effects in comparison with the criterion of the Ministry of Labour in Japan (MLJ). Forty male patients recognized as an occupational disease were examined in two times (mean interval periods 3.0 years). The subjects were free from vibratory tasks during the mean period of 8.3 years. The clinical examinations and some laboratory tests were conducted with the same procedures by the two same occupational physicians. The criterion of MLJ was graded more severe than Stockholm one for the vascular component at the first examination. According to Stockholm criterion, 16 patients (40%) were classified into stage 0 in the vascular component, 11 (70%) of which complained of coldness in the fingers. At the second examination, 9 of 16 patients in stage 0 had Raynaud's phenomenon (RP). On the other hand, the criterion of MLJ could reflect an improvement of symptoms, for example, coldness. The findings may indicate that Stockholm criterion for vascular component is not enough to assess the clinical changes for light stages according to the severity of RP alone. For the sensorineural (SN) component, both criteria were almost compatible. From the viewpoint of preventive medicine, it was concluded that Stockholm criterion was not suitable for evaluating their clinical severity in the early stage of HAVS.

Disability Evaluation↗
PubMed1995

A new criterion proposed for the diagnosis of hand-arm vibration syndrome.

To propose a new criterion for the diagnosis of hand-arm vibration syndrome (HAVS), we evaluated the severity of the patients in comparison with the criterion of the Ministry of Labour in Japan (MLJ) and the Stockholm criterion. The characteristics of the Stockholm criterion was to classify severe cases with vascular disorders, because of evaluation due to the frequency of Raynaud's phenomenon alone. The Stockholm criterion diagnosed the HAVS separately in vascular and sensorineural disorders. The MLJ criterion was able to subdivide light stages. In vascular disorders, the MLJ criterion made serious consideration about cold sensation which appeared long before the occurrence of Raynaud's phenomenon. The MLJ criterion diagnosed the patients with vascular, sensorineural and motor (musculoskeletal) system disorders comprehensively. A new criterion which we proposed includes sensorineural, vascular and motor system disorders, the grade of which is evaluated in each system. The diagnosis might be done comprehensively.

Cold Temperature↗
PubMed1994

Pathophysiology and clinical picture of hand-arm vibration syndrome in Japanese workers.

Hand-arm vibration syndrome is an occupational disease induced by long-term use of vibratory tools such as rock drills and chain saws. The three major stressors of vibration, noise and cold may produce various symptoms and signs not only with peripheral circulatory, nervous and muscle-joint disorders but also with general disorders. It is a point of controversy whether the symptoms and signs should be limited in the peripheral disorders. The question may involve differences in definition: vibration alone or work mode with vibratory tools. There are two viewpoints in the staging: peripheral and general viewpoints. The key concept in the peripheral viewpoint staging is a checkup to find disorders at the early stage and classify the peripheral disorders of the digits in detail. The general viewpoint staging seeks to grasp the general pictures of patients, and to classify from light to severe cases in the treatment. Clinical manifestations may include the general disorders in proportion to the severity of the syndrome according to our clinical experience. A differential diagnosis should be carefully made in the light of legal, medical and economic compensation. The treatments that we have used for approximately 20 years have beneficial effects on the whole-body, which include 1) physiobalneotherapy (therapeutic exercise, exercise in a pool and physiotherapy), 2) drug therapy (vasodilating drugs, autonomic stabilizers, etc.), 3) nerve blocking therapy, 4) surgical therapy for ulnar nerve paralysis or paresis, and 5) education for patients. Even with these therapies, a beneficial effect may not be observed in a short period. The recovery may be slow.(ABSTRACT TRUNCATED AT 250 WORDS)

Arm↗
PubMed1994

[Perceived health of persons and their practice of health promoting activities].

The perceived health of persons and their practice of health promoting activities were surveyed using a self-rating questionnaire with 49 items assessing level of health, practice of health promoting activities, life styles, health education, and participation in health screening for general health conditions and cancers. The questionnaires were mailed to 2,500 residents of a city, aged from 30 to 69 years old, randomly selected according to the composition ratios of the populations in the city. Persons from 2,333 subjects (1,057 male and 1,276 female) were effectively collected, representing about 1% of the city's population. General health was good in about 85% of the subjects, with decreases observed with age. Practice of activities for health promotion was wide-spread among the subjects. These activities included regularity, diet, nutrition, smoking and drinking control, physical exercise, sleep, and rest. The subjects expressed strong fear of cancers and concerns about deterioration in physical fitness. Their target life style was one with adequate sleep and rest, regularity in eating, good nutrition, and avoidance of overwork. Health screening participation rates were low at approximately 28% because of their perceived good health, and busy daily life and work. It appears that the perceived health of citizens may not always correlated with the practice of health promoting activities.

Adult↗
PubMed1993

[Difference in perceived health between blue- and white-collar workers of a manufacturing factory by a self-administered questionnaire].

In order to examine the differences in which blue- and white-collar workers perceive their own health status, a survey using self-administered questionnaire was conducted. The subjects were 1,428 male workers in a tire manufacturing factory, consisting of 1,185 blue-collar workers and 243 white-collar workers. Most of the blue-collar workers were engaged in shift work consisting of three shifts/d. The questionnaire included 32 items concerning health habits, life and job satisfaction, mental stress, and type A behavior. The following findings were obtained. Good daily health habits were related to age. Older workers had better health habits than the younger ones both in white- and blue-collar workers. The white-collar workers were more satisfied with their life and jobs, and also showed type A behaviors at a higher rate. As for fatigue and dissatisfaction association with shift work, the workers' complaints increased in the order of day shift, evening shift and midnight shift. The older workers had fewer complaints than the younger ones. These results suggested that health management and education will be more effective if the working conditions and the background of each worker are taken into consideration.

Adult↗
PubMed1992

[A 4 degrees C-1 min method of cold water immersion test for peripheral circulatory function in fingers].

To assess the validity of a new simplified cold water immersion test (4 degrees C-1 min method) for peripheral circulatory function, comparison was made with the conventional method (10 degrees C-10 min method). These two different methods of cold immersion test were applied to 23 patients with vibration disease and 24 healthy men. Observation was made on finger skin temperature by a thermistor and complaints in the hand by a 5-step self-reported scale method every minute during the test. The patterns of recovery of skin temperature after cold immersion in each group were similar in both methods. Pain in the hand in the 4 degrees C-1 min method was less than that in the 10 degrees C-10 min method. The recovery rate at 5 min in the patients with Raynaud's phenomenon was lower than that in those without Raynaud's phenomenon in the 4 degrees C-1 min method (p < 0.01). However, no significant differences were noted in 10 degrees C-10 min method. The results suggest that the new method is feasible in detecting the response of vasodilation after immersion. In the recovery rate at 5 min after immersion, near values of the sensitivity and specificity were observed between 50% cut-off values in the 4 degrees C-1 min method and 30% value in the 10 degrees C-10 min method. Thus, the 4 degrees C-1 min method is considered to be more useful to evaluate the physiological response after cold immersion than the 10 degrees C-10 min method.

Adult↗
PubMed1990

Cardiovascular reflexes during vibration stress.

Vibration disease due to hand-held vibratory tools has various symptoms and signs which can be characterized by the severity. They include disorders of the central and autonomic nervous systems, as well as peripheral system disorders. The mechanism of Raynaud's phenomenon in vibration disease is proposed to be: Vibration and cold affect the local vessels and nerves directly, leading to enhanced release of chemical vasoconstrictors. Vibration, noise, cold, ergonomic and biodynamic conditions, and emotional stress during work result in disorders of the central and autonomic nervous systems. In the early stages, the autonomic nervous system may be stimulated, and in the later stages it is suppressed. When local vessel injuries and disorders of the central and local autonomic nervous mechanisms controlling the vessels occur, vasospasms in the fingers develop when the whole body is exposed to cold. The cardiovascular system, other than the peripheral circulatory system, may adapt to vibration stress. The adaptation subsides 7 to 8 years after discontinuation of the use of hand-held vibratory tools.

Cardiovascular System↗
PubMed1989

Responses of myocardial blood flows to whole-body vibration in the dog.

Experimentally acute exposure to whole-body vibration resulted in changes in myocardial blood flows in the in vivo dog. Regional myocardial blood flows measured by a hydrogen gas clearance method were increased at a vibration frequency of 120 Hz and decreased at 50 Hz. No appreciable changes were found in presence of a beta-adrenergic blocker. The values of plasma cyclic nucleotides were increased at both frequencies of vibration, more at 50 Hz than at 120 Hz. No significant changes were observed in heart rates and arterial pressure during and after vibration load. These findings suggest that increased myocardial blood flows in response to vibration may be related more to the frequency of vibration than to beta-adrenergic actions.

Animals↗
PubMed1989

Frequency dependence of the suppressive effects of vibration on atherosclerosis in the rabbit.

Whole-body vibration suppresses the development of atherosclerosis in the rabbit (Oki and Matoba, 1987). The present study was designed to clarify whether the effect of vibration on atherosclerosis depends on the frequency of vibration. Longitudinal vibrations at a frequency of 30 or 60 Hz was applied to 12 New Zealand white rabbits for 12 weeks. The gradual decrease in body weight and blood hematocrit in the vibration groups with time were parallel to the changes in the controls. The rate of increase in serum lipid concentrations induced by a cholesterol-rich diet was significantly suppressed in the vibration groups, as compared to the controls. This may be due to the vibration and not the diet. The aortic wall was thinner at 60 Hz than at 30 Hz, whereas the ratios of trace metals (Ca/Mg and Zn/Cu) in the aortic tissues were smaller at 30 Hz. The area of plaque formation in the intima was smaller at 60 Hz than at 30 Hz (p less than 0.05). Thus, the suppressive effect of vibration on the development of atherosclerosis in the aorta may be greater at a frequency of 60 Hz than at 30 Hz. Vibration may play an important role in lipid metabolism.

Animals↗
PubMed1987

Physiological methods used in Japan for the diagnosis of suspected hand-arm vibration syndrome.

In the pathogenesis of hand-arm vibration syndrome, vibration affects the peripheral system, especially the circulatory, nervous, and musculoskeletal systems. Medical questionnaires, physical examinations, and laboratory tests are used to diagnose the hand-arm vibration syndrome. The laboratory tests are satisfactory diagnostic aids for detecting slight disorders of the peripheral circulatory, nervous, and musculoskeletal systems. Peripheral circulatory function tests include skin temperature measured by a thermistor under specific temperature conditions, the nail compression test, and the cold provocation test (10-min immersion in cold water at 5 or 10 degrees C). To assess peripheral nervous function, tests for the pain and vibration senses are included. Peripheral musculoskeletal function tests consist of grip strength, pinch strength and tapping counts. These physiological tests are applied in worker screening twice a year. These tests have been authorized by the Ministry of Labour since 1973. Several criteria for the tests, although not authorized, are widely used. The diagnostic implication of each separate test may be low. Consequently, some laboratory tests should be evaluated, along with medical questionnaires and physical examinations, in the diagnosis of suspected hand-arm vibration syndrome.

Arm↗
PubMed1986

Comparable effects of oral diltiazem and verapamil in the treatment of hypertrophic cardiomyopathy. Double-blind crossover study.

The effects of oral diltiazem, 180 mg/day, were compared with those of oral verapamil, 240 mg/day, in 32 patients with hypertrophic cardiomyopathy (HCM), using a double-blind crossover study design. In the first treatment period, diltiazem and verapamil improved subjective complaints in 83% and 71% of those who were symptomatic in the baseline period. Maximal oxygen consumption on exercise stress test increased with verapamil by 2.9 +/- 4.2 ml/Kg/min (p less than 0.05), and tended to increase with diltiazem. Verapamil also reduced the amplitude of negative T wave. In the statistical analysis based on the crossover design, diltiazem and verapamil did not differ in global improvement, overall safety and global utility ratings. In addition, both drugs showed comparable effects on electrocardiographic and echocardiographic variables and exercise tolerance except for minor differences in diastolic blood pressure, T wave amplitude and peak exercise heart rate. On the other hand, verapamil tended to induce more serious side effects, forcing the discontinuation of medication in 3 patients. Therefore, the present study indicates that diltiazem is essentially equally as effective as verapamil and is preferable in the treatment of patients with HCM since it may exhibit fewer serious side effects.

Administration, Oral↗
PubMed1985

Body reactions during chain saw work.

Body reactions during chain saw work were studied in 14 subjects. The subjects divided into three groups (control, sulpiride, and propranolol) successively cut down logs with a chain saw for seven minutes. The start of the sawing led to a pronounced increase in heart rate which persisted during the sawing. The groups taking sulpiride and propranolol showed a smaller increase in heart rate compared with the controls. Hormonal values (adrenocorticotropic hormone (ACTH), cortisol, adrenaline (Ad), noradrenaline (NA), and dopamine) were increased by the operation. A comparison of these values before and after the operation showed that the increase of cortisol, Ad, and NA values was highest in the controls, intermediate in the propranolol group, and lowest in the sulpiride group. The increase in ACTH, however, was greatest in the sulpiride group, intermediate in the controls and correct in the propranolol group. These findings provide some evidence that chain saw work may have an influence on the whole body, including the hypothalamus and the limbic lobe of the brain.

Adrenocorticotropic Hormone↗