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Biomedical subjects

T Matoba

Publications and source records attributed to T Matoba.

At least 19 recordsLinked to original sources
PubMed2005

Obesity is associated with increased risk of allergy in Vietnamese adolescents.

BACKGROUND: The prevalence of allergic diseases has remarkably increased in the last decades in tandem with the number of obese individuals. Results of studies on obesity and allergic diseases are controversial, and most of them are related to asthma and asthma-like symptoms. OBJECTIVE: In our study, we evaluated the association of several obesity indices and the prevalence of allergic diseases, including bronchial asthma, allergic rhino-conjunctivitis, atopic dermatitis and food allergy. DESIGN: Cross-sectional study. RESULTS: From a total of 1185 adolescents (49.3% boys) aged 12 to 17 y old, 19.3% reported a physician-diagnosed allergic disease, and 35.3% reported undiagnosed allergic symptoms. Logistic regression analysis revealed a higher risk of allergy in children of middle (OR = 2.02, CI: 1.12-3.64) and high (OR = 2.40, CI: 1.25-4.61) compared to low socioeconomic status, in subjects reporting industrial emissions in the neighborhood (OR = 2.19, CI: 1.40-3.41), and in adolescents with parental history of allergy (OR = 1.92, CI: 1.26-2.92). Body mass index (BMI) and percentage of body fat (%BF) were significantly related to allergy (OR = 1.16, CI: 1.01-1.34 for BMI; OR = 1.03, CI: 1.01-1.06 for %BF). After controlling for socioeconomic status, industrial emissions and parental history of allergy, only %BF remained statistically significant (OR = 1.03, CI: 1.01-1.06). Food allergy was not related to obesity in our study population, and when adolescents with food allergy were excluded from the analysis, the odds of having allergy increased 28% with each increase in SD of BMI (OR = 1.28, CI: 1.05-1.57) and 5% for each unit increase in the percentage of body fat (OR = 1.05, CI: 1.01-1.08). CONCLUSION: In conclusion, being overweight was associated with an increased risk of allergy in our study population. Our results point towards an association between being overweight and rhino-conjunctivitis, but not food allergy. No association was observed with other allergic diseases.

Adolescent↗
PubMed2000

The mechanism of a human reaction to vibration stress by palmar sweating in relation to autonomic nerve tone.

OBJECTIVES: To clarify the mechanism of a human reaction to vibration stress by palmar sweating in relation to the autonomic nerve tone. METHODS: The autonomic nerve tone was divided into four types by using digital photoelectroplethysmography (PTG) with auditory stimuli: normal (N), hyperreactive (I and D), and hyporeactive (P) types. Palmar sweating and digital PTG were simultaneously measured on the right palm and middle finger, respectively, in 20 healthy men. The left hand gripping the handle with a grasp strength of 49 N was exposed to vibration at a frequency of 125 Hz and acceleration magnitudes of 0 m/s2 (as a control), 30 m/s2, or 50 m/s2 for 3 min. The volume of palmar sweating was recorded before, during, and 30 min after vibration load. Three kinds of drugs related to the autonomic nervous system were orally administered to the subjects. Then 80 min after administration, the experiments were repeated. RESULTS: Of 20 subjects, 17 showed normal autonomic nerve tone (N type), and 3 hyperreactive (I type). The palmar sweating reaction to vibration in I-type subjects was greater and lasted longer than that in N-type subjects. Vibration with an acceleration of 50 m/s2 produced the greatest reaction which was about 7 times larger than that at 0 m/s2 and 2.5 times that at 30 m/s2 (P < 0.01). Sulpiride decreased palmar sweating during vibration, while prazosin and scopolamine inhibited it. CONCLUSIONS: The palmar sweating reaction to vibration stress was related to the background level of the autonomic nerve tone. The sweating volume was in direct proportion to the acceleration magnitude of vibration. The reaction of palmar sweating to vibration stress may be mediated through both the adrenergic and cholinergic fibers of the autonomic nervous system.

Adrenergic alpha-Agonists↗
PubMed2000

Hydrogen peroxide is an endothelium-derived hyperpolarizing factor in mice.

The endothelium plays an important role in maintaining vascular homeostasis by synthesizing and releasing several endothelium-derived relaxing factors, such as prostacyclin, nitric oxide (NO), and the previously unidentified endothelium-derived hyperpolarizing factor (EDHF). In this study, we examined our hypothesis that hydrogen peroxide (H(2)O(2)) derived from endothelial NO synthase (eNOS) is an EDHF. EDHF-mediated relaxation and hyperpolarization in response to acetylcholine (ACh) were markedly attenuated in small mesenteric arteries from eNOS knockout (eNOS-KO) mice. In the eNOS-KO mice, vasodilating and hyperpolarizing responses of vascular smooth muscle per se were fairly well preserved, as was the increase in intracellular calcium in endothelial cells in response to ACh. Antihypertensive treatment with hydralazine failed to improve the EDHF-mediated relaxation. Catalase, which dismutates H(2)O(2) to form water and oxygen, inhibited EDHF-mediated relaxation and hyperpolarization, but it did not affect endothelium-independent relaxation following treatment with the K(+) channel opener levcromakalim. Exogenous H(2)O(2) elicited similar relaxation and hyperpolarization in endothelium-stripped arteries. Finally, laser confocal microscopic examination with peroxide-sensitive fluorescence dye demonstrated that the endothelium produced H(2)O(2) upon stimulation by ACh and that the H(2)O(2) production was markedly reduced in eNOS-KO mice. These results indicate that H(2)O(2) is an EDHF in mouse small mesenteric arteries and that eNOS is a major source of the reactive oxygen species.

Acetylcholine↗
PubMed1999

Suppressive mechanism of gastric motility by whole-body vibration.

OBJECTIVE: To investigate the mechanism of gastric motility suppression by exposure to whole-body vibration (WBV). METHODS: The gastric motility was evaluated by electrogastrography (EGG) under food intake and autonomic nerve blocking agents in ten healthy volunteers. Sinusoidal vertical vibration with a frequency of 4 Hz (1.0 ms(-2) rms) was given to the subject for 10 min. RESULTS: The amplitude of EGG wave and the power spectrum corresponding to the slow wave component was remarkably decreased by vibration exposure. Food intake enhanced the gastric motility about 2.5-fold in the power spectral density. During and after vibration exposure, the response mode was similar to those at fasting states. Under the influence of anticholinergic (scopolamine) and alpha-adrenergic blocking agents (prazosin), the power spectra were decreased. A further decrease was observed during vibration exposure. A beta-adrenergic blocking agent (propranolol) led to a marked increase in the amplitude of EGG and its power spectrum. With pretreatment by a beta-adrenergic blocking agent, however, vibration exposure reduced both of them. CONCLUSIONS: These results suggest that short-term exposure to WBV can suppress the gastric myoelectric activity, the responses on which may be mediating by neurohumoral effects as well as the mechanical effect of WBV.

Adrenergic Antagonists↗
PubMed1999

A strategy for health promotion among unemployed people in Japan.

OBJECTIVE: To describe the unemployment situations in Japan and to propose a strategy for promoting health among unemployed persons. METHODS: The published government reports and the actual circumstances were analyzed to make an action program on the basis of social and occupational situations in Japan. RESULTS: The unemployment rate was low as compared to that of other countries because of two major reasons. One was that the workers were absorbed in minor or family corporation despite unsatisfactory job. The other was based on the financial support system for adjusting employment by the government. In an action program for promoting health of the unemployed persons, the same health care system as workers should be applied to the unemployed in the regional center of occupational health.

Health Promotion↗
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↗