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Volume 45 (1990 - 199･･･
- Issue 6 Pages 1029-
- Issue 5 Pages 947-
- Issue 4 Pages 849-
- Issue 3 Pages 735-
- Issue 2 Pages 613-
Volume 45, Issue 4
Displaying 1-10 of 10 articles from this issue
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Akira Babazono1990 Volume 45 Issue 4 Pages 849-859
Published: October 15, 1990
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSThe study evaluated the impact of the October 1984 introduction of 10% cost sharing on insured persons belonging to the Employees' Health Insurance Scheme. There was a total of 199 subjects with hypertension, all of whom were insured by a health insurance society under the scheme from January 1982 to March 1986.
The consultation rate for hypertension, as revealed by the medical receipts, was studied with time sequential analysis to evaluate the impact. Moreover, the differences of the impact pertinent to sex, age, medical facility, first year of visit and complications were analyzed.
The results are as follows.
1. The study disclosed an increase in the rate of consultation during the six-month period before the introduction and a substantial decrease in the rate during the following six months. The impact proved to be temporary because the rate of consultation returned to the originally estimated level.
2. The impact on insured persons whose first year of visit was more recent was larger than that of those whose first year of visit was before 1980. The impact on patients with complications was larger than that on those without complications.
3. The effect of the first year of visit was independent of that of complications.View full abstractDownload PDF (1184K) -
Tadashi Honda1990 Volume 45 Issue 4 Pages 860-872
Published: October 15, 1990
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSThere have been many attempts to quantitatively measure the hardness of skin-muscle, but no objective method for doing so has been established, because there is no universal standard for the hardness of organisms. The author considered elasticity and viscosity as the most important mechanical properties of the hardness of skin-muscle and applied the Maxwell model, in which a spring and a dash-pot are arranged in a series, to the static mechanical behavior of skin-muscle. A relatively large globular pressing body with a radius of 5mm was set as a transducer in the measuring system, so that the conformity of the practically measured values to those calculated theoretically by the model was increased. Strain of skin-muscle is expressed as a function of the load, which includes indices of elasticity (1/M) (M(N/mm2)=E/(1-λ2) (E: Young's modulus, λ: Poisson's ratio)) and viscosity (1/η) (η: modulus of viscosity) in a particular region. Because hardness is defined as the degree of resistance against transformation by loading, decreases in the indices of both elasticity and viscosity mean increases of hardness. With 150 male and female office workers chosen as the subjects, the model was examined and the indices were calculated. The results were as follows.
1) Very good conformity of practically measured values to those calculated theoretically by the Maxwell model was recognized within the range of load velocity from 0.3G to 3.0G (N/sec).
2) In both males and females the regions with values nearest to those of a Newtonian fluid were, in descending order, the distal phalanxes of digiti 2-4, the palm, the distal phalanx of the first digitus and the arm. In reverse order these regions approached complete elasticity.
3) In males it was suggested that the element of viscosity in the region of the biceps brachii muscle and the hardness in the regions of the brachioradialis, the flexor carpi radialis and palmalis longus muscles and the distal phalanxes of the 4th and the 5th digiti were increased with age. In females, a decrease in hardness in the region of the biceps brachii muscle with age was observed.
4) The indices of not only elasticity, but also of viscosity in females were higher than those in males. The results showed that for both elasticity and viscosity, the hardness of skin-muscles in males were higher than that in females.
Furthermore, the index of plasticity was determined by examining the mark remaining after unloading, and good correlation of the index to age was observed.
These results were considered very effective in comparing the hardness of skin-muscle induced by different occupations and by exercise.View full abstractDownload PDF (3254K) -
Norimitu Saitoh, Yasuhiko Wada, Akio Koizumi, Sigetosi Kamiyama1990 Volume 45 Issue 4 Pages 873-883
Published: October 15, 1990
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSNitroarenes, potent rodent carcinogens, have attracted much attention as environmental contaminants. Recently, simultaneous exposure to dust have been found to potentiate tumorigenicity of nitroarenes in rats (14). We hypothesized that inhabitants of northwestern Japan may be exposed to such substances in winter. First, we sought to develop a sensitive yet time saving method to determine nitroarene concentrations in airborne particulate matter. The method developed used a highperformance liquid chromatograph equipped with a fluorescence detector. By on-column catalytic reduction, using silica coated with platinum and rhodium, 1-nitropyrene (1-NP), 1, 3-dinitropyrene, 1, 6-dinitropyrene, and 1, 8-dinitropyrene were effectively reduced to their amino derivatives which were easily detectable with the fluorescence detector. The lowest detectable limits found using the present method were on the order of picograms for individual compounds. Subsequently, we sought to determine the concentrations of nitroarenes using the new method on airborne particulate matter during the period from November to April. Samples were collected at sampling sites on road with high-volume air samplers for 24 hours or 72 hours in four different rural areas in Iwate Prefecture. At one location in the city of Morioka, samples were collected at the height of 25m from the ground. Among the four nitropyrenes mentioned above, only 1-NP was detected in the samples. The concentrations of 1-NP and airborne particulates changed significantly in all examined areas in parallel with the rise and fall of the frequencies of studded tire use. The highest 1-NP and airborne particulate concentrations were 1, 210pg/m3 and 1, 291μg/m3, respertively, being recorded at the busiest road in Kitakami. In contrast, the lowest values were 38 to 66pg/m3 for 1-NP and 54 to 94μg/m3 for airborne particulates in Morioka, being recorded in November and Aprill, respectively. The mutagenicities of extracts of airborne particulate matter showed similar trends. Thus, exposure situations with high concentrations of dust and 1-NP were confirmed to occur in Iwate. Finally, the risk posed by 1-NP in airborne particulate matter was estimated using the equation proposed by Cuddihy and McClellan (37) and was found to range from 3.12×10-2 to 24.2×10-2 lung cancer/year/106 people. Although the estimated risk due to 1-NP is relatively small, further surveillance is highly recommended in those areas since heavy dust exposure also occurs there.View full abstractDownload PDF (1327K) -
Hideo Yoshikawa, Munehiro Yoshida, Ichiro Hara1990 Volume 45 Issue 4 Pages 884-889
Published: October 15, 1990
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSChanges in electroretinograms (ERG) due to administration of chlorpyrifos were examined in rats. Male Wistar rats were intraperitoneally injected with chlorpyrifos (0.2mmol/kg body weight), and their cholinesterase (ChE) activities and ERG were measured at various times after the injection. Amplitudes of A and B waves in ERG were more than 50% decreased and latencies of the waves were prolonged 10-20% from 5h to 2d after the injection. At the same time, activities of ChE in plasma, erythrocytes, brain and retinochoroid were remarkably decreased. However, the amplitudes and latencies recovered to the control level more rapidly than the ChE activities of the erythrocytes, brain and retinochoroid.
Injection into rats of 0, 0.002, 0.01, 0.05 or 0.25mmol/kg of chlorpyrifos showed that the chlorpyrifos-induced changes of ERG were dose-dependent, and that a level of 0.05mmol/kg caused a 50% decrease in the A or B wave 5h after the injection.
These results indicate that chlorpyrifos caused abnormal ERG characterized by decreased amplitudes and prolonged latencies of A and B waves and that the abnormal ERG did not always correspond to the decreased retinochoroid or brain ChE activities.View full abstractDownload PDF (805K) -
20-year follow-up survey in the Oki-Islands, Shimane Prefecture, JapanYoichiro Fukuzawa, Takuji Kishimoto, Miyoko Abe, Manabu Tada, Noboru M ...1990 Volume 45 Issue 4 Pages 890-903
Published: October 15, 1990
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSIn 1968 (the first survey), the food intake patterns and smoking and drinking habits of the 3, 546 male and 4, 350 female inhabitants aged 40-74, of the Oki-Islands, Shimane, Japan were investigated. The response rates were 64% for males and 65% for females.
A second survey according the same protocol was carried out from 1987 to 1988. A total of 1, 140 males and 1, 694 females were randomly selected from the cohort members who were completely followed up from 1968 to 1987. The overall response rates at the second survey were 91.2% for male and 88.9% for female. The results are summarized as follows:
1. ‘Saltless’ dietary habits significantly advanced in both sexes of all age groups (40-49, 50-59, and 60-74 years old in 1968) and in both hypertensives and normotensives; the frequency of pickle intake significantly decreased, while that of miso soup intake did not change.
Nutritional improvement was remarkable in that the frequency of fish, meat, eggs, milk, green vegetable and fruit intakes increased in both sexes of all age groups and in both hypertensives and normotensives.
2. The frequency of smoking significantly decreased in all age groups and in both male hypertensives and normotensives, in contrast with that of drinking. The frequencies of smoking and drinking showed the same tendencies in females.
3. The frequencies of smoking, drinking, and miso soup intake were higher in males who died from strokes than in those who died from other causes from 1968 to 1987, in contrast with the intakes of eggs and milk. The frequencies of fish, eggs, and milk intakes in hypertensives of both sexes who died from strokes were lower than in those who died from other causes from 1968 to 1987.
4. The life expectancy of normotensives was longer than that of hypertensives in both sexes of the two age groups studied (40-59 and 60-74 years old in 1968) during the past two decades.View full abstractDownload PDF (1659K) -
Ryoichi Inaba, Shinya Watanabe, Akira Okada, Takashi Moroji1990 Volume 45 Issue 4 Pages 904-908
Published: October 15, 1990
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSTo investigate the effects of whole-body microwave exposure on plasma corticosterone, glucose, uric acid and allantoin levels, rats weighing 245-300g (light group) and 440-510g (heavy group) were exposed to microwaves with a frequency of 2, 450MHz at the power density of 10mW/cm2 under an ambient temperature of 21 to 23°C for one hour. Rectal temperatures were increased by 3.4°C in the light group and 1.4°C in the heavy group after microwave exposure. Plasma levels of corticosterone, glucose and uric acid did not change in both groups after microwave exposure. Plasma levels of allantoin increased significantly only in the heavy group after microwave exposure. These results suggest that the plasma levels of allantoin, a metabolite of uric acid, may be useful as a biological variable for assessment of the effects of whole-body microwave exposure in rats. The increase of plasma allantoin level after microwave exposure could not be explained only by the degree of increased rectal temperature caused by hyperthermic effects of microwaves.View full abstractDownload PDF (617K) -
Kenji Morinaga, Satoshi Yutani, Ichiro Hara1990 Volume 45 Issue 4 Pages 909-918
Published: October 15, 1990
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSThe risk of cancer was analysed in a cohort of 604 male workers who had been engaged in manufacturing and/or handling benzidine and/or beta-naphthylamine during the period 1945-71 at two factories located in the city of Osaka. The cohort was followed up from 1 January 1970 to the date of death or 31 December 1986. The mean follow-up time was 16.1 years. A total of 84 deaths was found compared with 112.66 expected based on the mortality of the Osaka population. Thirty-six were found to be dead of malignant neoplasms; 9 stomach, 2 colon, 1 rectum, 3 liver, 1 bile duct, 1 pancreas, 1 maxillary sinus, 6 lung, 8 bladder, and 2 ureter neoplasms as well as 1 case of myeloid leukemia. Seven cases were ascertained on death certificates as neoplasms of uncertain behaviour, all of which were tumors of genitourinary organs except for one case of brain tumor. Cancers of genitourinary organs and tumors of uncertain behaviour showed statistically significant increased standardized ratios (SMR=12.20, 4.89). The mean age of death of those having genitourunary organs including cancer was 59 years old, and the latent period between the first exposure and the occurrence of the disease was 19.7 years on average. Non-significant increased risks of cancers of the colon, rectum, liver and lung were observed among the workers exposed to benzidine. Among the 7 histologically confirmed cases of these cancers, there were 2 adenocarcinomas of the lung, 1 adenocarcinoma of the rectum, 2 hepatocellular carcinoma and 1 adenocarcinoma of the bile duct. Seven patients with genitourinary tumors were found to have died of other primary cancers.View full abstractDownload PDF (1158K) -
Toshiyuki Tanaka, Takako Maeda, Yasuhisa Hayashi, Shoji Imai, Kazuhiko ...1990 Volume 45 Issue 4 Pages 919-925
Published: October 15, 1990
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSThe silicon (Si) concentrations in maternal serum and breast milk were determined for 38 healthy postpartal women, 19 primiparae and 19 multiparae, by using inductively coupled plasma-atomic emission spectrometry (ICP-AES).
The results are as follows:
1. The geometric mean (95% confidence interval) of the Si level in maternal serum was 9.7μmol/l (8.8-10.8μmol/l) at 1 week after delivery, and 8.1μmol/l (7.1-9.2μmol/l) at 1 month after delivery. The Si level at 1 week after delivery was significantly (p<0.05) higher than that at 1 month after delivery.
2. The geometric mean of the Si level (95% confidence interval), in breast milk was 6.3μmol/l (5.4-7.3μmol/l) at 1 week after delivery, and 6.1μmol/l (5.1-7.2μmol/l)at 1 month after delivery.
3. At both 1 week and 1 month after delivery, a significant correlation was not found between the Si concentrations in maternal serum and in breast milk.View full abstractDownload PDF (843K) -
Kumiko Miyake, Tetsuo Misawa, Sadayoshi Shigeta1990 Volume 45 Issue 4 Pages 926-934
Published: October 15, 1990
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSThe toxicity of his (tri-n-butyltin) oxide (TBTO) was studied in THA rats. Doses of 0 (control), 10 or 15mg/kg/day of TBTO were administered to adult rats for 12 consecutive days, and 0, 5 or 10mg/kg/day was given to pregnant rats from day 6 to day 20 of gestation by gastric intubation.
In the adult rat exposure experiment, the 15mg/kg group showed slightly decreased body weight and spontaneous motor activity, and a low avoidance rate in the Sidman avoidance test in the early stage of administration.
In the pregnant-rat exposure experiment, no effect of TBTO was seen in either the 5mg/kg or 10mg/kg groups in dams while all pups in the 10mg/kg group died by postnatal day 3. Little effect of TBTO on body weight, pinna detachment, incisor eruption, eye opening, surface righting, cliff avoidance, pivoting, negative geotaxis and auditory startle was found in the 5mg/kg pups. In the Sidman avoidance test, the avoidance rate of the 5mg/kg pups was lower than that of control pups in the early stage of the session. In a water E-maze test, the swimming time to the goal and the number of errors were increased in the 5mg/kg pups. In a reversal water E-maze test, increases of the swimming time to the goal and the number of errors made by the 5mg/kg pups were marked.
These results suggest that TBTO administration disrupts the learning acquisition of rats, and that the toxicity of TBTO is greater in prenatally exposured pups than in adult rats.View full abstractDownload PDF (1092K) -
Katsumi Yoshida, Hiroshi Matsuda, Takashi Muto, Haruhiko Sakurai, Haru ...1990 Volume 45 Issue 4 Pages 935-940
Published: October 15, 1990
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSHealth risks induced by the temporal course of weight gain were studied. Of 1, 627 male company employees, 437 subjects were selected as follows. The criteria for eligibility were: 1) A subject must have undergone more than 20 health checkups. 2) The subject's weight gain since adolescence must have exceeded 7 kilograms. Four hundred and thirty-seven subjects were selected using these criteria. The average subject's age was 46.2±5.1 (Mean±S. D.) years. Subjects were classified into 3 groups according to the rate of weight gain. As a result, 167 were classified as the rapid weight-gain group (defined as a weight gain of more than 5 kilograms per 5 years), 212 were designated as the moderate weight-gain group (less than 5 kilograms per 5 years) and 58 were assigned to a miscellaneous group (temporal weight loss during the observation period). This miscellaneous group was excluded from further analysis. Comparison between the rapid and moderate weight-gain groups indicated that the prevalence of abnormal fasting blood glucose levels was significantly higher in the rapid weight-gain group than in the moderate group (p<0.01). The Mantel-Haenszel overall odds ratio adjusted for the current relative body weight for the abnormal fasting blood glucose level was 2.86 (95% C. I.: 1.35-6.06). To determine the factors related to the occurrence of abnormal fasting blood glucose levels, stepwise logistic regression was performed by selecting the rate of weight gain, age, weight gain amount and current relative body weight as independent variables. Age and rate of weight gain were shown to be significant variables in abnormal fasting blood glucose levels. Accordingly, the rate of weight gain should be used when assessing the health risk induced by obesity.View full abstractDownload PDF (798K)
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