The aims of the present study were to observe the daily habituation to night sleep in a laboratory environment and to make clear the daily and individual sleep variations by using polygraph parameters, including electroencephalography (EEG). Sleep EEG records were obtained from a subject who slept ten successive nights, and from six subjects who each slept one night in the laboratory. The parameters used were as follows: sleep stage %, sleep latency (SL), REM latency (RL), number of stage shifts, subjective sleep, integral EMG, and slope (a) and intersect (b) of a regression equation used to estimate the sleep depth against sleep time.
Stage WAKE and SL, slope (a), intersect (b) and the mean depth of sleep were found to become stable from the fifth night. Stage MT, the number of stage shifts, and integral EMG increased significantly from the fifth night and later, showing p<0.01, p<0.01, and p<0.05, respectively. Judging from these findings, the sleep habituation of the subject in the laboratory was completed within the first four nights.
Coefficients of variation of sleep stage 2 and stage REM of the ten-nights' EEG were the lowest among all the sleep parameters examined. Almost all the parameters of day-to-day sleep of the subject who slept for ten successive nights in the laboratory showed smaller variations than those of the other six subjects. It may be concluded that the mist effect on sleep could be assessed more precisely by using an individual repeatedly than by using a group of subjects.

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To clarify the maternal-fetal transfer of cadmium across the placenta, cadmium was determined in 21 paired samples of maternal blood, placenta and umbilical cord blood obtained at delivery from pregnant women who did not smoke and had no particular exposure to cadmium compounds in their history.
Cadmium was detected in all the samples. In both maternal blood and umbilical cord blood, the cadmium concentrations in the red blood cells were remarkably higher than those in the plasma. The cadmium concentration in the umbilical cord blood was significantly lower than that in the maternal blood, suggesting that the placenta migth effectively block the transfer of cadmium to fetuses in pregnant women. The placental cadmium concentration was the highest in the samples determined. The ratios of placental to maternal blood cadmium concentration were very large, indicating that cadmium preferentially accumulates in the placental tissues. On the other hand, the ratios of umbilical cord blood to placental cadmium concentration were very small, indicating that the placenta constitutes an effective barrier against cadmium; that is, the placental cadmium is hard to transfer to fetuses in pregnant women. The significantly positive correlations between maternal blood and placenta, between placenta and umbilical cord blood and between maternal blood and umbilical cord blood in terms of the concentrations of cadmium suggest that the amount of cadmium accumulated in placenta and transferred from mother to fetus is strongly influenced by the cadmium body burden of the mother.

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Diving profiles of fishermen divers in the Izu Islands were investigated and recorded by DDR (Diving Data Recorder).
Consumed air volume during diving work was also checked in each dive and the work load was measured by Vo₂ during diving.
It was recognized that divers repeatedly experienced extreme descents and ascents, that were accompanied by increases of oxygen consumption. This suggested that the load of their work was far beyond that of sports divers.
The particular diving method used, called the "Qikomi Gyoho method" is to repeatedly dive several times to catch fish. Each bottom (diving) time is rather short and the depth changes from deeper to shallower areas gradually. This profile is considered to be a safe diving method for the prevention of DCS (Decompression Sickness). Hawever, stapping for decompression during ascent is sometimes required to prevent DCS according to analysis of the diving profiles. It is pointed out that the risk of DCS still remains with this diving method.

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A pilot study to improve unhealthy life habits of thirty middle-aged male clerical workers (45±3.58 yr.) with mild health disorders such as hypertension, hypercholesterolemia, diabetes mellitus and fatty liver was carried out. Under prohibition of smoking and alcohol intake, they spent five nights and six days at a hot spring resort, taking part in planned health training programs which included aerobic training, hiking in forests, hot spring baths, cooking practice and lectures about healthy life, controlled by medical, dietary and physical training staffs.
To evaluate the short-term effects of these activities, body weight, blood pressure, serum lipid (total cholesterol, high-density-lipoprotein cholesterol, triglyceride, total free fatty acid and phospholipid), blood sugar, uric acid, γ-glutamyl transpeptidase(γ-GTP)and glutamic-oxaioacetic transaminase (GOT) were examined early in the morning of the second (before) and the fifth (after) days, and then their impressions of these recreation activities were monitored by questionaires on the sixth day.
By t-tests of all before-and-after data, it was shown that mean values of body weight, systolic blood pressure, high-density-lipoprotein cholesterol, triglyceride, phospholipid and γ-GTP were improved, but fasting blood sugar, uric acid and GOT were not improved. In cornparrson of blood pressure levels, the hypertensive group (n=9) showed lowering in both systolic and diastolic blood pressure, though the normal group (n=10) had slight elevation. In addition, in the hypercholesterolemic group (n=11, ≥220mg/dl) mean total cholesterol values decreased, conversely in the hypocholesterolernic group (n=6, <180mg/dl) they increased. Moreover, the obese group (n=15, obesity index ≥120%) showed greater decreases of body weight, triglyceride and phospholipid than the non-obese group. From questionaires, it was confirmed that through these recreation activities most participants found mental and spiritual satisfaction, in spite of heavy physical loads.
The short-term recreation activities under a stressless environment seemed to maintain the function of homeostasis in the body, but further investigation is needed to examine the relation between the contents of diets and physical activities, and to follow the long-term effects on the participants.

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The serum concentration ofβ-carotene is an indicator of the carotenoid intake level in the individual^{1, 2)} as β-carotene is a principal component of the carotenoids, which are found mainly in green-yellow vegetables and some fruits. Recently, epidemiological studies have shown that the incidence of squamous lung cancer, which is known to be induced by smoking, is lower in persons with a higher intake of green-yellow vegetables^{3, 4)}, and that the serum concentration of β-Carotene is lower in lung cancer patients than in controls^3-8). Nomura et al.⁸⁾ showed, from a case-control study performed in Hawaii, that the serum level of β-carotene was lower in smokers than in nonsmokers. We have shown in a cross-sectional study that serum β-carotene levels are lower in inhabitants with habits of smoking and/or alcohol drinkinge⁹⁾. It is also reported that alcohol consumption leads to a lower intake of nutrients such as vitamins¹⁰⁾ and that chronic cigarette smoking is associated with decreased levels of plasma vitamin C and retinol¹¹⁾. However, the effect of alcohol consumption on the serum, β-carotene level in a general cancer-free population has not been reported.
In this study, the effects of the consumption of alcohol and cigarette smoking, and the frequency of the intake of certain foods on serum concentrations of α- and β-carotenes in healthy male adults are examined.

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One of the toxic effects of selenite is the development of bilateral nuclear cataracts in suckling rats. These lesions can be induced by a single subcutaneous injection of sodium selenite. Several studies have shown some biochemical changes associated with the selenite-induced cataract^1-3), but the mechanisms of selenite cataract formation are still unknown. Selenite is a strong sulfhydryl oxidant in vitro⁴⁾ and the aggregation of lens proteins by disulfide cross-links has been show to play an important role in cataract formation⁵⁾. A decrease in lens glutathione and a reduction in lens protein sulfhydryl have been reported in selenite-induced cataract^{1, 6)}. David and Shearer⁷⁾ reported that during selenite-induced cataractogenesis, there was no decrease in lens protein sulfhydryl content, though the loss of glutathione did occur. They claimed that the selenite-induced cataract could not be attributed to the reduction of lens sulfhydryl levels. As described above, explanations for the mechanism of selenite-induced cataract are controversial. Therefore, the purpose of this study is to further clarify the role of sulfhydryl oxidation in the cataract induced by selenite. Our findings are that inhibition of glutathione synthesis in rat pups induced by the intraperitoneal (i.p.) administration of buthionine sulfoximine (BSO) increased the cataract incidence caused by a single subcutaneous (s.c.) injection of selenite; furthermore, selenite induced the decomposition of lens protein and the formation of disulfide-linked lens protein aggregates in vitro and in vivo. Our data suggest that the oxidation of lens protein sulfhydryl by selenite is associated with selenite-induced cataractogenesis.

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The effects of a high-fat and high-cholesterol diet (HFC diet) on serum lipoproteins and apolipoproteins were studied in stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Kyo: Wistar rats (WKY). In particular, the changes in serum concentrations and distributions among lipoprotein fractions of apolipoproteins A-I, A-IV and E (apo A-I, A-IV and E) were investigated in detail. These apolipoproteins are the main protein constituents of high density lipoprotein (HDL) which is considered to be an anti-atherogenic factor and accounts for a large part af the serum lipoproteins in the rat.
Serum lipoprotein fractions were isolated by stepwise density-gradient ultracentrifugation. The alterations in lipoprotein fractions and apolipoproteins in lipoprotein fractions were roughly estimated by native gradient polyacrylamide gel electrophoresis and sodium dodecyl sulfate (SDS)-gradient polyacrylamide gel electrophoresis. Next, the concentrations of apo A-I, A-IV and E in serum, serum lipoprotein fractions and serum lipoprotein-free fraction were measured by rocket immunoelectrophoresis according to the method of Laurell as modified by us. Cholesterol was enzymatically determined by a commercially available kit.
The results obtained were as follows:
1) A remarkable increase in the very low density lipoprotein (VLDL) and intermediate density lipoprotein (IDL) fractions was observed in WKY and SHRSP. This was associated with a remarkable increase in the cholesterol and apo B contents and with a significant increase in the apo E content. These changes in the VLDL and IDL fractions were more drastic in SHRSP than in WKY, which suggests the promotive effect of hypertension in SHRSP on the production of VLDL and IDL fractions.
2) A marked increase in the low density lipoprotein (LDL) fraction was observed in WKY and SHRSP. This was attributed to the increase of native LDL and/or HDLc. In SHRSP, the cholesterol and apo B contents increased remarkably and the apo E content increased significantly, though it was lower than in WKY. These changes indicate that the increase in the LDL fraction in SHRSP was mostly due to the increase of native LDL rather than HDLc. On the other hand, the increase in the LDL fraction in WKY was due to increases of both native LDL and HDLc.
3) A distinct decrease in the HDL fraction was observed only in SHRSP. This was associated with a significant decrease in the cholesterol and apo A-I contents but there was no change in the apo AIV content, though there was a remarkable reduction in the apo E content. These changes indicate that the distinct decrease in the HDL fraction in SHRSP was due to a decrease of two HDL subfractions, apo A-I HDL and apo E HDL.
4) A significant increase in the apo A-IV content in the lipoprotein-free fraction was observed only in SHRSP. This is probably related to the accelerated digestion and/or absorption of lipid by the intestine in SHRSP.

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An improved and simplified Head Space Method was devised for measurement of the concentration of odorants dissolved in waste water, and this method was examined to determine whether it was applicable for this purpose or not.
This method is taken into consideration the variableness of liquid concentration and of gas pressure resulting from the volatilization of odorants and aqueous vapor to the atmosphere.
By this method, the constants of hydrogen sulfide, dimethylsulfide and trimethylamine were measured under various temperatures and pHs. As a result of comparison with the measured values obtained by the Stripping Method and those from the heretofore used Head Space Method, this method appeared to be fairly applicable.

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In Japan, it is required to measure the hydrogen sulfide (H2S) concentration before sewerage work can commence, in order to prevent toxic accidents caused by H2S. The actual H2S concentration of the sewerage hole is often different from that initially measured, and there is often a more than fatal concentration because of rapidly volatilizing H2S. However, no countermeasures for this have been developed, nor has any system for the measurement of the H2S held in sewerage water and sludge been established yet.
In this paper, therefore, the measurement of H2S dissolved in water was investigated, and the actual form of the H2S held in the water and the sludge was analyzed. Prevention measures against toxic accidents were also investigated. Water and sludge were collected from an actual sewerage hole, and the quantities of H2S held in them were measured by the new method with the stripping which we developed. We also determined the quantity of H2S volatilized from the water surface during work, and estimated the change of air quantity necessary to reduce the concentration of H2S to a safety level for workers.
As a result, it was shown that even if the H2S concentration of the gas phase before the work is regarded as at a safety level for workers, they may be in an extremely dangerous situation resulting from the rapid volatilization of H2S during their work. Thus, in order to guarantee the safety of workers, it is necessary that the H2S concentration of the water and the sludge should be measured before the work commences, that the volatilizing quantity should be estimated based on these measured values, and that the required amount of ventilation should be estimated.

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It is well known that taurine, a final metabolite of sulfur-containing amino acids, plays an important role in bile acid metabolism and that it also has a moderately hypotensive effect. Moreover, it has recently been revealed that taurine shows a hypocholesterolemic effect in animals with experimentally induced hypercholesterolemia. However, the hypocholesterolemic mechanism remains unresolved.
Stroke-prone spontaneously hypertensive rats (SHRSP) easily develop hypercholesterolemia when fed a high-fat and high-cholesterol diet (HFC diet). In our previous paper, we reported changes in the concentrations and distributions of serum lipoproteins and apolipoproteins in hypercholesterolemic SHRSP and Kyo: Wistar rats (WKY) induced by HFC feeding.
In this paper, to elucidate the mechanism of the hypocholesterolemic effect of taurine, we investigated the effects of taurine on concentrations and distributions of serum lipoproteins and apolipoproteins in hypercholesterolemic SHRSP and WKY induced by HFC feeding.
The results obtained were as follows:
1) The hypocholesterolemic effect of taurine in hypercholesterolemic SHRSP was remarkable in comparison with that in hypercholesterolemic WKY.
2) The hypocholesterolemic effect of taurine was mainly due to a marked suppression of extreme elevations of cholesterol contents in the VLDL and IDL fractions of both strains. This was associated with a decrease in the elevated contents of apo B and apo E which are major components of VLDL and IDL. This suppressive effect was more obvious in SHRSP than in WKY, which explains the greater hypocholesterolemic effect of taurine in SHRSP. It could be that, as a result of taurine administration, the catabolism of cholesterol to bile acid in the liver is accelerated, followed by a decrease of the hepatic cholesterol pool, resulting in a suppression of the synthesis and/or secretion of VLDL (β-VLDL) in the liver.
3) The hypocholesterolemic effect of taurine was also observed in the LDL fractions of both strains, but the effect was not as strong as that observed in the VLDL and IDL fractions. This effect might be attributable to suppression of the synthesis and/or secretion of LDL in the liver and a decrease in the elevated content of apo E HDL (HDLc) which spans two density fractions (the LDL and HDL fractions).
4) In HDL fractions of both strains, the decreased content of apo E HDL (HDL1 and HDLc) was even lower, whereas the decreased apo A-I content in the HDL fraction of SHRSP was significantly restored and the cholesterol level was slightly elevated. However, the decrease of apo E HDL which could be considered to be a protective or anti-atherogenic lipoprotein seems to be unfavorable for the antiatherogenic effect of taurine. This discrepancy will be an important subject of study in the future.

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Serum retinol and tocopherol concentrations in 419 males and 478 females, aged 10 to 49 years, were determined by an HPLC method. Then their relationships to serum lipid concentrations and smoking and drinking habits were examined. Retinol levels were higher in males than in females but tocopherol showed little difference by sex. The sex differences in age-related serum levels of retinol and triglyceride (TG) were similar to those of tocopherol and total cholesterol (TC), respectively.
Retinol had a significant correlation with TC and TG, with coefficients of 0.20-0.29 (p<0.001). These were smaller than those of tocopherol (R=0.32-0.52, p<0.001) both in males and females, suggesting that it had a higher susceptibility to factors other than serum lipids than tocopherol did.
Both the retinol and tocopherol levels were significantly higher in the groups with smoking and drinking habits than in the groups without them among the males aged 30 years and over. Furthermore, the retinol level was positively dependent on the daily consumption of both cigarettes and alcohol, whereas tocopherol was dependent on the consumption of alcohol. Multiple regression analysis showed that smoking and drinking habits had statistically significant effects on the serum retinol level independent of other factors and that their effects were greater than those of TC and TG. Tocopherol was affected most by TC and TG and then by drinking habit. Less significant but similar results were obtained for the females of the same age group.
Since smoking and drinking habits, known to be carcinogenic, was related to increases in the serum levels of retinol and tocopherol, it would appear to be necessary to study the relationship of these serum levels with tissue levels of vitamins A and E to examine their protective effects against carcino- and atherogenesis.

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We investigated the differences in manganese concentration and distribution in the brains of rats administered MnCl₂ perorally, intravenously and intraperitoneally for one week.
Forty two male Wistar rats were divided into eight groups, designated A to H. Groups A (n=5) and B (n=7) were maintained with synthetic diets, with 50 and 1000mg manganese per kg diets, respectively. Groups C (n=5), D (n=5) and E (n=5) were administered manganese intravenously with dosages of 0.088, 0.88 and 2.2mg/kg.b.w./day, respectively. Groups F (n=5), G (n=5) and H (n=5) were administered manganese intraperitoneally with dosages of 0.088, 0.88 and 2.2mg/kg.b.w/day, respectively. Four brain regions (cerebrum, cerebellum, basal ganglia and the remainder) were analyzed by atomic absorption spectrophotometry for manganese.
The manganese concentrations in basal ganglia were increased proportionally to the administration dosages in intravenous administration groups (C, D and E). At the highest dosage of manganese administration, manganese concentrations in cerebrum and basal ganglia were higher with intravenous administration of manganese than with intraperitoneal administration. In addition, manganese concentrations were hardly increased in peroral administration groups. Therefore, we suggested that basal ganglia are vulnerable to manganese exposure and that liver and intestine might play the important roles in the reduction of manganese accumulation in the central nervous system.

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In order to clarify synthetically the situation concerning air pollution by suspended particulate matter (SPM) in the vicinity of the Meishin Expressway, polycyclic aromatic hydrocarbons (PAHs), which are typical substances adsorbed on SPM, were determined by the high-performance liquid chromatography method, and the distribution of the PAHs concentrations was examined.
The concentration of benzo (a) pyrene (B(a)P) at a point 60m from the road edge was 2.93ng/m³ (9.11μg/g dust). The concentration of benzo (ghi) perylene (B(ghi)P) was 6.62ng/m³ (20.6μg/g dust) at this point, being the highest of all the PAHs that were analyzed in this study.
The concentrations of PAHs that were contained in 1g of dust were the highest in the SPM fraction from 0.7 to 1.6μm in diameter. The concentrations of PAHs that were contained in particles under 5.4 μm in diameter, and which are absorbed extremely easily into the lung, occupied more than 90% of the concentrations of PAHs that were contained in the total SPM.
When there was a high frequency of perpendicular wind, the concentrations of PAH_s in SPM fractions under 1.6μm in diameter showed a marked tendency to have a clear concentration-distance profile, but when there was a high frequency of parallel wind, it was observed that these concentrations at a point 120m from the road edge were much higher than at the road edge.
The correlation coefficient between the concentrations of B(a)P and the traffic volume of large vehicles was elevated with the increase of distance from the road edge and was statistically significant at a point 290m from the road edge.

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