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Biomedical subjects

R Inaba

Publications and source records attributed to R Inaba.

At least 55 records · Page 3Linked to original sources

[Biting force and physical fitness in athletes].

The maximum biting force in 82 male athletes and 12 male subjects without any particular athletic activity (nonathletes) were measured in order to evaluate the relationship between biting force and physical fitness in athletes. The results obtained were as follows. 1. The maximum biting force in athletes (50.8 +/- 17.4kg) were significantly (p < 0.01) higher than that in the nonathletes (28.1 +/- 9.1kg). The maximum biting forces in the men who belonged to the rugby or judo clubs were predominantly higher than in other subjects. 2. In men who masticated on the left side of the mouth, the habitual (i. e., left) biting force was significantly higher than the nonhabitual (i. e., right) biting force. In men who masticated on the right side of the mouth, the habitual (i. e., right) biting force was also higher than the nonhabitual (i. e., left) biting force, but was not significantly so. 3. There was a significant positive correlation between the biting force and grip strength and back strength in athletes. In athletes, there was a significant correlation between biting force and the numbers of chin-ups, the numbers for the side-step tests and the time for 50m running.

Adult↗

[Effects of ingestion of "BON-NARINE" on immune functions in mice].

A study was carried out to examine the effects of ingestion of "BON-NARINE" (BN) on mice immune functions. Mice aged 12 weeks were divided into 4 groups. The first group was given BN at 30 mg/kg (BN-30 group), the second group was given BN at 90 mg/kg (BN-90 group), the third group was given zymosan at 50 mg/kg (Zy group) and the fourth group was a control receiving no treatment. The mice of groups BN-30 and BN-90 were given BN p.o. at doses of 30 mg/kg and 90 mg/kg per day for 20 consecutive days, respectively. The mice of group Zy were given zymosan i.p. at a dose of 50 mg/kg per day for 2 consecutive days. The results obtained were as follows: 1) Potentiation of phagocytic function of the reticuloendothelial system, examined by the carbon clearance method, was seen in the BN-30, BN-90 and Zy groups. 2) The glucose consumption of peritoneal macrophages (M phi) increased significantly in the BN-30 and Zy groups, but not in the BN-90 group. 3) Superoxide anion (O2-) production of peritoneal M phi significantly increased in the BN-30 and Zy groups compared with the control group, but an increasing tendency was observed in the BN-90 group. 4) The acid phosphatase (APH), beta-glucuronidase (GLU) and lactate dehydrogenase (LDH) activities of peritoneal M phi increased significantly in the BN-30, BN-90 and Zy groups. 5) The proliferation of splenocytes induced by Con A in the BN-30, BN-90 and Zy groups significantly increased compared with the control group. These results demonstrated that the ingestion of "BON-NARINE" promotes phagocytic activity in the reticuloendothelial system in mice and has a stimulatory effect on M phi because of increases in glucose consumption, O2- production, APH, GLU and LDH activities in the peritoneal M phi of mice. BN also intensified the T-cell function represented by Con A-induced splenocyte proliferation.

Animals↗

Noise in aerobic facilities.

Noise levels were evaluated before and during aerobic sessions in 3 aerobic studios. In addition, hearing threshold levels (HTLs) of 10 female aerobic instructors with the mean (+/- SD) ages of 25.4 (+/- 2.4) years were measured before and 2 min after an aerobic session. The mean (+/- SD) of total instruction time of these subjects was 1274.0 (+/- 704.9) h. Before the aerobic session, noise level was 63 dB(A) and increased to 87 dB(A) during a warm-up period. The highest noise levels of 93-96 dB(A) were recorded during a peak exercise period and decreased to 73 dB(A) during a cool-down period. The dominant spectra of sound pressure levels (SPLs) during the aerobic session were in the frequency range of 1-2 kHz at levels of 75-88 dB(C). The mean values of HTL obtained for each ear of these subjects were between 5 and 15 dB in the frequency range of 1-8 kHz. No significant differences in the mean HTLs of pre- and post-aerobic sessions could be obtained. The mean values of HTL of two groups of subjects divided by their total instruction time (n = 5 in each group, and p < 0.01 in their total instruction time) were quite comparable.

Adult↗

Effect of hand-arm vibration on inner ear and cardiac functions in man.

To evaluate distant effects of hand-arm vibration we studied Finnish forestry workers using chain saw during the years 1972 through 1990. The hearing was tested annually and individual regression curves for sensorineural hearing loss (SHL) were calculated. Robinson's model was used in prediction of SHL. The heart rate variation (HRV) indexes at rest and during deep breathing test were analyzed to measure autonomic nervous function. In Robinson's model the measured SHL (17.8 dB) respected the predicted SHL (17.2 dB). The subjects with VWF had on average, 10 dB greater hearing loss than those who did not have VWF. The regression model based increase of hearing loss during follow up correlated with ageing, not to VWF. The intercept differed significantly in those with VWF from those without VWF. We found a significant difference between HRV indexes during deep breathing test in those with the shortest and those with the longest vibration exposure. The HRV decreased with age, but multiple regression analysis showed that the total exposure time to vibration had an independent negative association with HRV indexes. Our results suggest that prolonged exposure to vibration caused by chain saw has negative effects an autonomic functions. The aggravated hearing loss in subjects with VWF may be due to vibration induced changes in the autonomic nervous system or internal factors of the blood vessels.

Arm↗

Operating hand-held vibrating tools and prevalence of white fingers.

Hand-transmitted vibration levels (HTVLs) and the prevalence of vibration-induced white finger (VWF) and numbness of the hands were investigated in eight groups of subjects operating various hand-held vibrating tools. The prevalence rates of Raynaud's phenomenon (RP) and numbness of the hands in 1,027 males and 1,301 females not occupationally exposed to vibration were compared to those of the exposed subjects. The prevalence of VWF was in the range of 0.0-4.8% in subjects exposed to HTLVs of between 1.1 to 2.5 m/s2 and reached 9.6% in a group of workers exposed to HTLVs of 2.7-5.1 m/s2. The latter group showed a significant difference (P < 0.05) in the prevalence of VWF compared to the 2.7% prevalence of RP in male subjects of the general population. The prevalence of VWF in female subjects exposed to vibration (4.3%) was not significant compared to the prevalence of RP in females of the general population (3.4%). The prevalence rates of numbness of the hands were between 6.5% and 30.4% in the exposed groups and in the range of 13.4-29.5% in the general population. It was concluded that in decisions concerning quantitative recommendations for vibration exposure, the prevalence of VWF should be employed. To decrease the risk of developing VWF, estimated vibration safety values for 4 h and 2 h daily exposures are discussed.

Adult↗

[Study on odor control using wood vinegars (II). Application of wood vinegars to piggery wastes].

The effectiveness of wood vinegars was studied for controlling offensive odors from piggery wastes. Odorant chemicals and the sense of odors from piggery farm, covered with polyvinylchloride film to prevent the volatilization to ambient air, were measured in both laboratory and in situ in order to evaluate the degree of deodorization. The results obtained were as follows: 1. The odorant chemicals from piggery wastes were identified as ammonia, methyl sulfide, hydrogen sulfide, butyric acid and valeric acid. Among them, the major chemicals being responsible for the sense of odor were butyric acid and valeric acid. 2. In a laboratory experiment using an air tight vessel, the amount of wood vinegars needed for deodorization of piggery wastes was 6.6%; The removal efficiency of the odorant chemicals volatilized from the wastes was from 70 to 90% of control levels. 3. In situ test at a piggery farm showed that removal efficiency of odorant chemicals was similar to that of the laboratory experiment. In sensory tests, authorized by the Environmental Protection Agency of Japan, minimal offensive odors were observed with the addition of 6.6% wood vinegars. Furthermore, flies were rarely observed, indicating that wood vinegars may play an important role as a repellent.

Acetates↗

Cutaneous signs (Raynaud's phenomenon, sclerodactylia, and edema of the hands) and hand-arm vibration exposure.

Dermatological tests and examinations of the hand(s) were carried out in vibration-exposed and unexposed males. The subjects were 179 chain-saw workers in private forestry companies and 205 local inhabitants who had never used vibrating tools. The prevalences of Raynaud's phenomenon (RP), sclerodactylia, and edema of the hands were estimated in both groups, and associations between these cutaneous signs and vibration exposure were evaluated. The prevalences of RP and edema in the exposed group were 9.5% and 1.7%, respectively, and in the unexposed group, 2.9% and 1.5%, respectively. Sclerodactylia was seen in 31.8% of the chain-saw workers but in only 6.4% of the unexposed individuals. In statistical analyses based on unconditional logistic regression models with adjustment for age, RP was associated with long-term (> or = 20 years) vibration exposure [odds ratio (OR) = 7.06; 95% confidence interval (CI) = 2.51-19.87]. Sclerodactylia was associated with both short- and long-term vibration exposure (OR = 6.54, CI = 3.30-13.36; OR = 7.05; CI = 3.41-14.60, respectively). There were significant dose-response relationships between RP and duration of exposure and between sclerodactylia and duration of exposure. Results of function tests indicated a longer recovery time and a higher vibration threshold for the workers with RP. The presence of sclerodactylia, however, did not have any significant influence on function test results. It is possible to conclude that not only RP but also sclerodactylia could be induced by vibration exposure. However, most cases of sclerodactylia were not so serious as to involve disturbances of peripheral circulatory and nerve function.

Adult↗

Prevalence of Raynaud's phenomenon and specific clinical signs related to progressive systemic sclerosis in the general population of Japan.

BACKGROUND: In order to evaluate the prevalence rates of Raynaud's phenomenon (RP) and specific clinical signs related to progressive systemic sclerosis (PSS) in the general population of Japan, inquiries were made concerning RP in the hands and dermatologic examinations were also conducted. METHODS: One thousand and sixty-three subjects (332 men and 731 women) over 30 years of age who underwent inhabitants' health examinations in 1990 were considered for this study. RESULTS: The prevalence of RP was 3.0% in men and 3.4% in women. In 8 men and 17 women with RP who received the blood tests, the positive rates of antinuclear antibody (ANA) were 12.5% and 35.3% in men and women, respectively. The prevalence rates of all five specific clinical signs related to PSS, sclerodactyly, pitting scars of the fingers, brown pigmentation of the body, shortened frenulum of the tongue, and flexion contracture of fingers, were under 2% in men and 3% in women. In women with RP the prevalence rates of sclerodactyly, pitting scars of the fingertips, brown pigmentation of the body, and shortened frenulum of the tongue were 16.0, 4.0, 4.0, and 16.0%, respectively. These values were significantly higher than those of persons without RP. CONCLUSIONS: Because some persons with primary RP may become typical cases of PSS within several years, a followup study, particularly for women who have positive titers of ANA with RP, should be carried out to find out whether the persons suffer from PSS or not.

Adult↗

[Effects of exercise in the growing stage in mice and of Astragalus membranaceus on immune functions].

A study was carried out to examine the effects of forced running exercise in the growing stage in male ICR mice and of Astragalus membranaceus (As) on their immune functions. The mice were divided at 4 weeks of age into 4 groups. The first group of mice received forced running exercise (E-group), the second group was given As (As-group), the third group received the forced running exercise and was given As (E+As-group) and the fourth group was a control receiving no treatment. The exercise received was forced running at 15 m/min on a flat floor without any slope for 60min a day. The mice of groups E and E+As were exercised 5 times a week for 12 weeks. The mice of groups As and E+As were given As p. o. at 200 mg/kg per day (5 days/week) for 12 weeks. The results obtained were as follows: 1. After 12 weeks of forced running exercise, the weight of the anterior tibialis muscle and succinate dehydrogenase activity in the anterior tibialis muscle increased significantly in groups E and E+As compared with the control group. Thymus weight showed a tendency to increase in groups E and E+As as compared with the control group. 2. The potentiation of the phagocytic function of the reticuloendothelial system examined by the carbon clearance method was seen in groups E, As and E+As. 3. Superoxide anion production of peritoneal macrophages significantly increased in groups As and E+As, but not in group E. 4. The acid phosphatase activity of peritoneal macrophages in groups E, As and E+As significantly increased compared with the control group. 5. Interleukin 1 production by macrophages remained in all groups. 6. The proliferation of splenocytes induced by Con A in groups E, As and E+As significantly increased compared with the control group. These results suggested that forced running exercise in the growing stage in mice and the administration of As enhanced immune functions and that they might also intensify the functioning of the host defense system.

Acid Phosphatase↗

[Effects of exercise on immune functions in mice].

This study was carried out to examine the effects of forced running exercise on the immune functions of male ICR mice. Mice aged 4 weeks were divided into two groups: a non-exercise group (control) and a group given forced running exercise (exercise group). The exercise applied was forced running at 15m/min on a flat floor without any slope for 60 min a day. The duration of exercise was 5 days per week for 12 weeks. The results obtained were as follows: 1) After 12 weeks of forced running exercise, the weight of the anterior tibialis muscle and succinate dehydrogenase activity in the anterior tibialis muscle increased significantly (p < 0.01) in the exercise group compared with the control group. A tendency for thymus weight to increase was shown in the exercise group, and liver and spleen weights were significantly (p < 0.01) greater than in the control group. 2) The potentiation of phagocytic function of the reticulo-endothelial system, examined by the carbon clearance method, was seen in the exercise group. 3) The ability of peritoneal macrophages (M phi) to phagocytose latex beads significantly increased (p < 0.01) in the exercise group. The acid phosphatase activity of peritoneal M phi remained in both groups. However, lactate dehydrogenase activity of peritoneal M phi significantly increased (p < 0.01) in the exercise group compared with the control group. 4) The proliferation of splenocytes induced by Con A in the exercise group significantly increased (p < 0.01) compared with the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

A survey on noise exposure level in an aluminum can production plant.

The present investigation was designed to quantify noise exposure of laborers at various sections of an aluminum can production plant. The acoustic environment in each area was described by sound pressure level (SPL). Decibel (dB) readings were taken for a range of individual frequencies and weighting scales (A and C). Speech interference level (SIL) values for laborers in different production sections were also determined. Moreover, by means of a personal noise dosimetry technique, the equivalent continuous noise exposure level (dB(A)) during an 8-h shift (Leq, 8) was computed. The results obtained were as follows. Spectral analysis of the noise indicated that high SPL associated with high frequency noise exceeded the permissible limit against hearing damage, and it generally amounted to levels higher than 90 dB(A), whereas those inside the control rooms were in the range of 54-60.5 dB(A). Assessment of the results obtained from personal noise dosimeters also revealed that the Leq,8 values were higher than the prescribed limit (85 dB(A)). By preliminary audiometric examinations on the right ears of workers, hearing threshold shifts (HTS) were noticed in the range of 7-11 dB at 1 kHz and 12-16 dB at 4 kHz. With regards to the SIL values (93.2-96.5 dB(A)) which were more than the maximum vocal effort, communication between workers and/or with supervisor were appraised to be very difficult (shouting) or impossible. It was concluded that (a) the dB readings observed in this survey indicate a potentially serious possibility of hearing disability, even though high level of HTS could not be noticed in the preliminary audiometric test, and (b) the risk of accidents should also be taken into account regarding the nonauditory effects of such a high level of noise. We suggest that (1) minimizing the transmission of noise through acoustical countermeasures need to be considered, and (2) introducing a schedule comprising on-time and off-time could be beneficial in a workers' health conservation program.

Aluminum↗

Exposure to segmental vibration and noise in orthopaedists.

The results of several field visits to orthopaedic clinics and the data obtained from a postal questionnaire were used to evaluate the segmental vibration and noise exposure levels in orthopaedists. The analysis of 54 (85.7%) complete questionnaires showed that hand-held plaster saws were used (Mean +/- SE, 12.3 +/- 1.7 min/week) more often than other tools. The mean frequency-weighted acceleration levels while using these tools were in the range of 2.3-2.4 m/s2. The A-weighted sound pressure levels in orthopaedic clinics while using the same instruments were in the range of 88.7-93.4 dB(A). Regarding the vibration magnitude and exposure time, segmental vibration seems not to be a serious problem in orthopaedists. However, the noise level produced from operating orthopaedic tools may have deleterious effects such as masking of speech communication among staff members. Patients' sleep or rest was thought to be disturbed by such noise levels.

Adult↗

[Study on odor control using wood vinegars].

The effectiveness of wood vinegars reducing or eliminating offensive odors, associated with cattle breeding, was studied. The results obtained were as follows: 1. Analyzed were 0.7-7.2% acetic acid and 0.5-1.8% methyl alcohol as main contents. 2. Gaseous odorants, such as ammonia, trimethylamine, n-butyric acid were almost eliminated through absorption using 1-20% wood vinegar solutions. 3. The same gaseous odorants, mentioned above, when confined to an airtight vessel, were eliminated in a short time by adding a little volume of wood vinegars to it. The effect was maintained for 2 weeks. 4. A sensory test was performed to evaluate the degree of deodorization, such as odor intensity and odor acceptability. Results showed that wood vinegars have a good deodorant effect on the offensive odors.

Acetates↗

Vibration syndrome among Finnish forest workers between 1972 and 1990.

A longitudinal study on vibration syndrome among professional forest workers was carried out in Finland from 1972 to 1990. In the course of the follow-up the weighted vibration acceleration of chain saws decreased from about 14 to 2 m/s2. The prevalence of vibration-induced white finger (VWF) decreased gradually from 40% to 5%. Numbness occurred mainly at night, and its prevalence decreased from 78% to 28%. During part of the follow-up period (1975-1990) the complaints of hand muscle weakness decreased from 19% to 9%. Disorders of the musculoskeletal system were considered to cause more disability than VWF. The decreased vibration acceleration and the lighter weight of chain saws were considered the main reasons for the decrease in the prevalence of vibration-induced symptoms.

Adult↗

Hand-arm vibration syndrome and its prevalence in the present status of private forestry enterprises in Japan.

Currently there are no limitations on age of employment on private forestries in Japan. Hence, it was hypothesized that in these kind of enterprises, elderly chain saw operators, or those with long-term exposure, might be at higher risk of developing hand-arm vibration syndrome (HAVS). We consequently investigated the prevalence of HAVS in 447 chain saw workers on private forestries in Gifu Prefecture, Japan, with particular reference to age and exposure period. Of this population, 43 (9.6%) had signs and symptoms of vibration-induced white finger (VWF), and among these workers the severity of finger blanching was significantly correlated (P less than 0.01) with the exposure period. Classification of all subjects by exposure period showed that workers with greater than or equal to 30 years' exposure had higher prevalences of VWF (20.9%) and numbness of the hands (25.4%) compared to other groups. Significant differences (P less than 0.01) were found between the functional capacities of workers with VWF and those of control subjects. We concluded that (a) the elderly chain saw operators and those with longer exposure should be moved to other jobs with a lower or no risk of exposure to vibration, and (b) the results of screening tests, even without cold water immersion (which we did not employ, in order to protect workers' hands), could be helpful for the identification of workers with VWF.

Forestry↗

Effects of whole body microwave exposure on the rat brain contents of biogenic amines.

The effects of whole body microwave exposure on the central nervous system (CNS) of the rat were investigated. Rats weighing from 250 to 320 g were exposed for 1 h to whole body microwave with a frequency of 2450 MHz at power densities of 5 and 10 mW.cm-2 at an ambient temperature of 21-23 degrees C. The rectal temperatures of the rats were measured just before and after microwave exposure and mono-amines and their metabolites in various discrete brain regions were determined after microwave exposure. Microwave exposure at power densities of 5 and 10 mW.cm-2 increased the mean rectal temperature by 2.3 degrees C and 3.4 degrees C, respectively. The noradrenaline content in the hypothalamus was significantly reduced after microwave exposure at a power density of 10 mW.cm-2. There were no differences in the dopamine (DA) content of any region of the brain between microwave exposed rats and control rats. The dihydroxyphenyl acetic acid (DOPAC) content, the main metabolite of DA, was significantly increased in the pons plus medulla oblongata only at a power density of 10 mW.cm-2. The DA turnover rates, the DOPAC:DA ratio, in the striatum and cerebral cortex were significantly increased only at a power density of 10 mW.cm-2. The serotonin (5-hydroxytryptamine, 5-HT) content in all regions of the brain of microwave exposed rats was not different from that of the control rats. The 5-hydroxyindoleacetic acid (5-HIAA) content in the cerebral cortex of microwave exposed rats was significantly increased at power densities of 5 and 10 mW.cm-2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Health condition of female aerobic dance instructors. Subjective symptoms and related factors].

Aerobic dance has recently become popular in all age groups, but the injuries among full-time and part-time aerobic dance instructors have rarely been pointed out in Japan. In this study the subjective symptoms of 63 female instructors in Gifu area were evaluated through health questionnaire. As a control group, 94 female students of the same age group were also included to compare the prevalence of subjective symptoms. Multiple logistic regression analysis was applied to observe the relation between instructors' symptoms and working conditions. The following results were obtained: 1) Complaints of leg and foot pain and laryngeal discomfort were significantly greater in instructors than in students even after adjusting for age and participation in other sports. 2) A significant positive relation was found in instructors between the frequency of dance lessons (times/wk) and various symptoms (calf pain, foot pain, sore throat, and hoarse voice) after adjusting for age and participation in other sports. These results suggest that leg and foot pain and laryngeal discomfort are characteristic symptoms of aerobic dance instructors. Consideration should be made to adjust the frequency of dance lessons in order to reduce these symptoms.

Adolescent↗