Showing papers by "Shosuke Suzuki published in 1992"

Increased urinary cadmium excretion and its relationship to urinary N-acetyl-β-D-glucosaminidase activity in smokers

Abstract: To assess the renal effects of low-level exposure to cadmium due to smoking we examined blood and urinary levels of cadmium and urinary excretions of N-acetyl-beta-D-glucosaminidase (NAG), beta 2-microglobulin (BMG) and metallothionein in 94 male workers aged 18-55 years. Both blood and urinary cadmium levels indicated excess exposure to cadmium caused by smoking. The urinary cadmium concentration ranged between 0.1 and 5.0 micrograms/g creatinine and increased significantly with age in the smokers. Neither urinary NAG nor BMG was increased in the smokers compared from non-smokers. A positive relationship between urinary cadmium and metallothionein was obtained not only in the smokers but also in the non-smokers. Furthermore, in the smokers urinary cadmium and metallothionein was positively related with urinary NAG. Since NAG in urine mostly originates from tubular cells by lysosomal exocytosis, the results may reflect an early cadmium effect on the lysosomal functions. Inhibitory effect of cadmium on the lysosomal degradation activities was discussed as a possible explanation of the positive relationship of urinary cadmium and metallothionein to urinary NAG.

Urinary cadmium and N-acetyl-beta-D-glucosaminidase excretion of inhabitants living in a cadmium-polluted area.

Abstract: Urinary cadmium (Cd), N-acetyl-β-D-glucosaminidase (NAG), and creatinine levels were determined for 400 inhabitants living in Cd-polluted districts of Annaka City in Gunma Prefecture, Japan. The Cd pollution was mainly due to falling dust from a zinc smelter factory according to seasonal winds. The Cd-polluted areas were divided into five administrative districts around the factory. The geometric mean of the urinary Cd level of the inhabitants in the five districts, Nodono, Iwai, Ooya, Nakajyuku, and Itahana, were 2.95, 2.66, 2.45, 1.97, and 1.67 μg/g creatinine, respectively. The geometric means for Nodono and Iwai are statistically larger than that for Itahana (P < 0.01). These results were well explained by the wind direction and proximity to the factory. In addition, a two-way analysis of variance on the urinary Cd level was made using place of residence and smoking habits. The effect was mainly due to the place of residence, and no interactions were found. There were statistically significant differences in NAG excretion among the five groups, but no difference could be found between two groups using a multiple comparison. Pearson's correlation coefficient between the logarithm of urinary Cd content and that of NAG was 0.203, but statistically significant (r = 0.462 without creatinine correction; P < 0.01). The present results indicate the association of urinary Cd and NAG levels in a Cd-exposed population whose geometric mean of urinary Cd content is about 2 μg/g creatinine. We recommend a continuous survey of the minimum health effects of the Cd pollution using urinary levels of Cd and protein including NAG.

Factor structure of self-rating depression scale by Zung and prevalence of depressive state of night shift workers.

Abstract: The Zung self-rating depression scale (SDS) was applied to Japanese night shift workers of a railway company in order to assess the prevalence of depressive state and clarify the structural characteristics of the SDS questionnaire.Out of 2, 394 employees, 1, 931 male workers were engaged in night shift work and 1, 274 men (66.0%) completely answered the questionnaire. The control group was selected from daytime workers.The average age of the subjects was 39.4. Cronbach's alpha coefficient of the night shift workers was 0.835 and that of the control was 0.848. SDS index decreased with age. The mild, moderate, and severe depressive state of night shift workers evaluated by SDS were 13.7%, 2.1%, and 0.6%, respectively. A two-way analysis of variance on SDS index examined age and shift work. Age influenced SDS index, but there was no interaction between the factors. Two factors were extracted by factor analysis. Factor 1 consisted of 8 positive items, accounting for 16.7%. Factor 2 consisted of 8 depressive items, accounting for 15.6%. The residual four items consisted of somatic or behavioral features. Mean value of SDS index by age, distribution of SDS index, and factor structure of SDS questions of the night shift workers were similar to those of the control group.

[The effect of noise on sleep--changes in hypnograms of subjects exposed to repeated truck-passing sound].

Abstract: The effect of traffic noise on sleep was evaluated in an experimental room using repeated recorded truck-passing sounds. The peak sound level was 55, 60 or 65 dB (A) with frequencies of three times per hour. The background noise of the exposure night was Leq 42 dB (A) and that of the control night was Leq 35 dB (A). The subjects were five students 23 to 24 years old. The sleep stage of each epoch with a 20-second duration was judged visually based on the criteria of Rechtschaffen & Kales and the data of the second night of noise-exposure and the control night were used. The sleep parameters used were total sleep time (TST), each sleep stage, % of sleep stage against TST, sleep efficiencies, sleep latency, REM latency, REM cycle, REM duration, waking from sleep, number of stage shifts, and subjective sleep judged by the OSA sleep inventory. A paired t test was used for the statistical analysis. TST, REM stage in minutes, and % of REM stage against TST of the exposure night were significantly decreased compared with those of the control night. Other objective and subjective parameters showed no changes during noise exposure. Dividing the all-night into halves, the amount and % of each sleep stage were compared between the exposure and control night. There was no change of sleep stage in the former half, but the % and amount of REM sleep in the latter half were significantly decreased as a result of the noise exposure. The decreases of REM sleep and % REM against TST, especially in the latter half of all-night sleep, were caused by the intermittent truck-passing sounds 20 to 30 times per night. Language: ja

Instantaneous changes in sleep stage due to the sound of a passing truck

Abstract: The instantaneous effect of the sound of a passing truck on sleep of five male students, 23 to 25 years of age, was assessed. The peak levels of noise were adjusted to 55, 60, and 65 dB (A) with intervals of 18 and 13 minutes, and a frequency of one per hour. Background noise in the experimental room was Leq 42 dB (A). The sleep stage of each epoch was visually judged based on the criteria of Rechtschaffen & Kales. Data for pre-exposure epochs of sleep stage 2 and rapid eye movement (REM) were collected and 18 epochs, including two under noise exposure, were evaluated. Three sets of polygraphic data were sampled as controls from 10 minutes after 65 dB (A) exposure to the next exposure. Compared with the control, the percentage of stage 2 to shallower stages (stage 1, waking, or movement time (MT)) was significantly increased by exposure to 55, 60, and 65 dB (A). The change lasted for one minute with exposure to 55 dB (A), and 2 to 3 minutes with 60 and 65 dB (A). A decrease in the percentage of stage 2 to deeper stages was observed at 2 to 4 minutes after exposure to 60 and 65 dB (A). The percentage of stage 2 to MT increased at 60 and 65 dB (A). The percentage of stage REM to other stages increased with the exposure to 60 or 65 dB (A) within 4 minutes. The threshold of instantaneous change of stage 2 to shallower stages due to the sound of a passing truck was at the peak level at less than 55 dB (A), and that of stage REM to other stages at 55 to 60 dB (A).

Validity of electrode placement at Fpz to detect alpha wave.

Abstract: The possibility on placing electrodes at Fpz-A2 instead of C3-A2 was investigated to obtain a more stable configuration avoiding obstruction by the hair. Our original system of alpha wave detection by a microcomputer was used, and a total of 22 all-night hypnograms of five healthy young students waa recorded. Pearson's moment correlation coefficients of alpha wave % between the two positions were 0.780–0.948. Except for one subject, alpha wave % taken at Fpz-A2 tended to be 3–5% lower than that at C3-A2. The above analysis indicates that using EEG electrode position of Fpz-A2 is valid and useful as a stable electrode configuration for a long-time monitoring.

Effect of the continuity and sampling rate of polygraphy data on sleep stage by a computerized scoring system--a reliability study.

Abstract: The percentage of each sleep stage determined by visual judgment was compared with computerized judgment using continuous and three intermittent sampling data. Comparison of stage agreements of four types of computerized judgments with visual judgment were also conducted. Hypnograms of six healthy young male students were recorded on each of five nights. Data of each subject were compiled individually, and the six data were analyzed. Agreement rate of the sleep stage by computerized judgment using continuous (method A), one-third (method B), one-ninth (method C), and one-fifteenth (method D) data with that of visual judgment were compared. The agreement rate of visual and computerized judgment using method A showed no difference from that between visual and computerized judgment using method B. There was a significant loss of agreement between visual and computerized judgment using method C or D compared with that between visual and computerized judgment using method A. Paired t-tests were conducted for each stage percentage against total sleep time of visual judgment and those of computerized judgments using method A, B, C, or D. There were no significant changes in any sleep stage percentages between visual judgment and computerized judgments using method A, B, C, or D. From sleep stage agreement and the degree of difference from visual judgment, the acceptable limitation of the sampling period was concluded to be one-third of continuous data.

Mental Health of Women Engaging in Community Works

Abstract: Physical and mental health level of 70 married couple, whose wives worked as volunteers of maternal and child health or diet improvement projects in a village of Gunma prefecture, was measured using a health questionnaire, the Todai Health Index (THI), consisting of 12 scales and 2 discriminant values. As controlled group, 68 men and 68 women randomly sampled from the neighboring village were set up. Mean values of scale scores of mental instability and depression of volunteer group were statistically smaller than those of control women, and that of aggressiveness of volunteer group was larger than that of control women. Scale scores of digestive organ and aggressiveness of husbands are higher than those of wives, and the reverse tendencies were found in the scores of mental instability and irregularity of life. Significant correlations were found between volunteers and their husbands in the scales: impulsiveness, lie scale, mental instability, depression, and irregularity of life, which were also found in the other married couples. These relation was not recognized in the control group. From these results, health level of wives who were volunteers of health promotion project of a village are mentally better or active compared with that of the control group, but there was little difference in the interaction of mental health between volunteer spouse and the other general one.

The Effect of Smoking and Place of Residence on Subjective Complaints of Employee and His Wife in Two Areas.

Abstract: Physical health levels of 95 married couples (group A), who live in the suburbs of big city, and 202 married couples (group B), who live in a local city of Kanto district, were measured using a health questionnaire, the Todai Health Index (THI). The male subject of both groups are workers of private company and the average age is early forties. This research was focused on the effect of smoking and place of residence on subjective complaints. Mean values of scale scores of couples' respiratory symptoms and husbands' digestive symptoms of group A were statistically higher than those of group B by the two-way analysis of variance. But no difference was recognized by the degree of smoking. Interactions existed on the effect of smoking and place of residence on the mean values of scale scores of wives' respiratory and digestive symptoms. These results indicate that respiratory symptoms and husbands' digestive symptoms increase by the modernization, but the effect of smoking habit on respiratory and digestive symptoms were relatively small.