Food has been considered an important factor for the genesis of cancer in man, as important as cigarette smoking. Diet influences the incidence of human cancer in many ways, directly and indirectly. Various kinds of carcinogens such as polynuclear aromatic hydrocarbons, N-nitro compounds and mycotoxins have been reported to be present in various foods. During the last decade, a new series of heterocyclic amines has been isolated as potent mutagens and later shown to be potent carcinogens in animals. Among them, carcinogenic tryptophan pyrolysates have been investigated from various points of view and useful pieces of information about them have been collected. Now, it is a matter of urgency to evaluate the effects of these carcinogens on humans. From this aspect, this review describes the information about carcinogenic tryptophan pyrolysates which has been collected and also future problems, especially those the hygienist will have to solve.

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Thirty-one male SD rats, six weeks old, were fed a trace element-deficient diet for two weeks and then divided into three groups and maintained for 1 week as follows: group A with total parenteral nutrition (TPN) without supplementation of trace elements, group B with TPN supplemented with the following 5 trace elements…iron, zinc, copper, manganese and iodine, and group C with a diet free of the above five trace elements. Another group of eight rats was fed a diet supplemented with the above five trace elements for three weeks as a control (group D). Feeding or TPN without supplementation of trace elements evoked microcytic hypochromic anemia and significant decreases in iron concentrations in plasma and tissues (groups A and C). Supplementation of trace elements in the TPN solution showed a tendency to cure anemia and a significant increase in the iron concentration in tibia (group B). Decreases in the zinc or copper concentrations in plasma and tissues during TPN without trace elements were prevented by supplementation of trace elements in the TPN solution (group B). The plasma zinc and copper concentrations correlated well with their levels in liver, kidney and tibia. Manganese deficiency was not recognized in this investigation (groups A and C), though supplementation of trace elements in the TPN solution increased tissue manganese concentration (group B). Feeding or TPN without supplementation of trace elements induced decreases in plasma triiodothyronine and thyroxine (groups A and C). Supplementation of trace elements in the TPN solution showed a tendency to increase plasma thyroxine (group B). These results suggest that feeding with a trace element-deficient diet followed by trace element-free TPN, decreases the trace element levels in tissues of rats, and that the addition of trace elements to the TPN solution shows a tendency to normalize such deficiency states.

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The present study was conducted to estimate the effects of the physical load of instructors during ice skating camp. The subjects were 9 instructors aged from 20 to 24. To discover measures to relieve the physical load, we measured 1) urinary excretion of catecholamine (noradrenaline; NA, adrenaline; A), 17-OHCS, creatinine and nitrogen; N each day, 2) subjective symptoms of fatigue three time a day (morning, after skating, and at night), 3) nutrient intakes, 4) performed a time study and 5) measured the heart rate during skating instruction.
The main results obtained were as follows:
1) The mean heart rate during skating instruction was 98.4-113.1beats/min.
2) Urinary excretions of NA, A, and 17-OHCS were observed to have increased gradually during skating camp. The values of NA, A and 17-OHCS in the skating camp period were significantly higher than those of daily life. Subjective symptoms of fatigue were also increased gradually. The construction of symptom clusters was of the I-dominamt type (I>III>II) at each point.
3) Intakes of energy, carbohydrate, protein and fat during the skating camp period were higher in comparison with those of daily life.
4) Urinary-N and creatinine levels during the skating camp period showed no changes. N-intake/urinary-N of the skating camp period tended to be higher than that of daily life.
5) In the time study, mean energy consumption was 3300-3400kcal/day. The mean time of skating instruction was 218-227min. The sleeping time was observed to have decreased gradually. The sleeping time (8th and 11th days) was significantly shorter than that of daily life.
6) The relationships between urinary NA, 17-OHCS and sleeping time were significantly correlated for all days composing the skating camp period.
These results suggest that the increased physical load on instructors is due to the decrease of sleeping time, the longer skating instruction time and that there was not enough free time, or enough rest days.

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A survey investigating the intake frequency of various foods and eating habits was made by a special form of structured questionnaire. Those who answered the questionnaire were 184 women aged from 40 to 59 living in a rural district in Kyoto Prefecture. They were divided into three blood groups according to the contents of hemoglobin (Hb) and serum cholesterol (T-CHO) as follows:
Group A (Anemia): Hb<12g/dl and T-CHO<220mg/dl
Group B (Normal): Hb≥12g/dl and T-CHO<220mg/dl
Group C (Hyperlipidemia): Hb≥12g/dl and T-CHO≥220mg/dl
As far as the intake frequency of each food and the eating habits of the three blood groups are concerned, there wasn't any notable difference. However, when the statistical method called "quantification theory II" was applied using the blood groups as the objective variable and the 27 items in the food frequency questionnaire, as well as the obesity index, as explanatory variables, it was found that the dietary patterns were different among the three blood groups. The result was that 68% of women in group A were discriminated correctly, as were 55% in group B, and 83% in group C.
The analysis of the data from food frequency questionnaires by the "quantificatin theory II" statistical methods seems to be useful to reveal dietary patterns.

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Factors in medical insurance records of two groups classified as participants and nonparticipants in a multiphasic health examination (MHE) conducted in a rural town in Kyoto prefecture were compared. The purpose of this study was to clarify how the conditions of medical care influenced the participation in the MHE. The factors were days of consultation, total insurance points and days of consultation classified by specific disease and the area of the medical facility. Participants were examined at least once in 1987-1988 and nonparticipants were never examined in the corresponding period. The data were obtained from the medical insurance records of outpatients for the period from April 1986 thru March 1987. The medical care bills of 170 males and 201 females aged 30-69 were randomly sampled from National Health Insurance records (unit=family), and those of 55 males and 88 females aged 70 and over were from the Medical Service for the Aged (unit=person). These samples were about one forth of target population respectively.
Both older participants and older nonparticipants of both sexes had more consultation days and more total insurance points than the corresponding younger subjects. Nonparticipants of both sexes aged 70 and over had more consultation days and more total insurance points than participants; female nonparticipants aged 50-69 had slightly more consultation days and those aged 30-49 also had more insurance points. Nonparticipants tended to have previous medical care for hypertension or ischemic heart disease, which the MHE is responsible for discovering. In contrast, participants had gastroduodenal ulcer, musculo-skeletal disease, cataract or diabetes mellitus, all of which the MHE is less responsible for detecting, except for diabetes mellitus. This indicates that participants perceived the importance of the MHE because of previous contact with diseases, and also that patients with diseases that could be detected by the MHE did not participate in the MHE because they were visiting clinics for the same diseases.
Participants of both sexes had more chance to visit a clinic in the town than nonparticipants, and especially those in large cities. However, older nonparticipants of both sexes had more days of consultation at medical facilities not in the town. This indicates that participants consisted of those who readily visited clinics with slight sicknesses or for further examinations after the MHE, and that nonparticipants consisted of two groups, those who never visited clinics because they were healthy and those who visited for long periods because of serious illness.

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The criteria of a good obesity index derived from height and weight are that (1) it should be highly correlated with weight, but independent of height and (2) it should be highly correlated with any reasonable obesity measures like skinfold thickness or body density.
We examined the usefulness of the Benn index relative to the traditional indices, the Kaup index and the Rohrer index, based on the above criteria. The subjects were 1200 students (600 boys and 600 girls) in the 9^th grade of 6 junior high schools in and around the city of Morioka, Iwate in 1985.
Three weight-for-height indices for each grade were calculated by the longitudinal data of their heights and weights from the 1^st to the 9^th grades.
As a result, the Benn index was found to best fit the criteria. So, we would like to recommend the use of the Benn index as the screening measure for obesity in school children.

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Biological response to stress was studied in the healthy elderly by fluctuations of their circadian rhythms using salivary cortisol levels as an indicator. Social activities per se may not be stressors, but may serve as a "eustress" to the elderly when they are in good health because their rhythm is maintained. Concerning the occupations of the subjects, the rhythms of elderly watchmen showed no disturbance when they slept for three hours between 23:00 and 2:00. However, those who were unable to sleep showed disturbed rhythms. We concluded that disturbance of a rhythm that has been established on the basis of being active during the day time and sleeping at night could be a stressor to the elderly rather than stress due to working as a guard.

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This study was conducted to investigate the relationship between life style factors and adult disease for Chinese living in Japan. The mortalities of major cancers and other major diseases of Chinese in Japan were compared with those of Japanese by calculating Standardized Mortality Ratios (SMR) for the Chinese using death rates in the Japanese population the standard. The life style data on smoking, drinking and dietary habits for Chinese in Japan were collecteg by self-administered questionnaire surveys, and age-adjusted proportions were calculated with the truncated world population as the standard. Then the corrected indexes on life style for Chinese in Japan were compared with those of Japanese. The results are summarized as follows:
1. The mortality rates of heart disease, diabetes mellitus, hypertensive disease, liver cirrhosis, rectum cancer, liver cancer (both sexes), lung cancer (females), breast cancer and cerebrovascular disease (females) for Chinese in Japan were higher than those for Japanese, but the rates of stomach cancer, pancreas cancer (both sexes), uterus cancer (females) and cerebrovascular disease (males) were lower than those for Japanese.
2. The prevalence of current smokers for Chinese males in Japan was lower than that of Japanese, and that of females was higher than that of Japanese. The prevalence of non-smokers for Chinese males was higher than that of Japanese, and that of females was lower than that of Japanese.
3. Although the prevalence of regular drinkers for Chinese of both sexes in Japan were lower than that of Japanese, the prevalence of heavy drinkers who drank over 80ml of ethanol every day for Chinese males was higher than that of Japanese males.
4. Significat differences were not found in the prevalences of frequent consumers of meat, milk, eggs, fish, other vegetables and food using oil between cooks and non-cooks of Chinese of both sexes in Japan.
5. The age-adjusted prevalences of frequent meat and milk consumers for Chinese in Japan were higher than those of Japanese in both sexes, but those of frequent pickled vegetable and MISO soup consumers were lower than those of Japanese. The dietary pattern of Chinese in Japan was different from that of Japanese with intakes of much fat and less salt.
6. It is assumed that the mortalities due to adult disease for Chinese in Japan are related to their heavy drinking and to their dietary habits.

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This experiment was carried out to investigate the effects of intravenous injection of an essential trace-element preparation (TE-5) on iron, zinc, copper and manganese concentrations, and blood biochemical and hematological parameters in rats. The rats were treated by intravenous injection of TE-5 for 7 days and the following results were obtained:
1) Neither a 0.04 nor a 0.4ml/kg/day injection of TE-5 affected the iron, zinc, copper and manganese concentrations in tissues.
2) At a higher dose (1.2ml/kg/day), iron concentrations in liver and spleen, zinc concentrations in liver, kidney, tibia and plasma, copper concentrations in heart, kidney and whole blood, and manganese concentrations in brain, heart, spleen, kidney, femoral muscle, tibia and whole blood increased.
3) At the highest does (4ml/kg/day), all rats died and iron, zinc, copper and manganese concentrations in tissues increased remarkably.
4) With injections of TE-5 (0.04-1.2ml/kg/day), hemoglobin, hematocrit, alkaline phosphatase activity and blood urea nitrogen decreased slightly.
These results suggest that iron, zinc, copper and manganese concentrations, and blood biochemical and hematological parameters are maintained at doses up to 0.4ml/kg/day of TE-5, but that doses higher than that destroy homeostasis.

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In order to clarify the role of nitrogen dioxide (NO₂) in the development of lung injury, male Wistar rats were exposed continuously to 0.3 or 5.0ppm NO₂ for 10, 20, 30, 60 and 90 days, and alveolar macrophages and lavage fluid obtained by bronchoalveolar lavage were examined. The results were as follows:
1) The number of alveolar macrophages increased significantly in response to NO₂ exposure. Throughout the whole test period, the largest number was obtained in the group exposed to 5.0ppm, followed by the group exposed to 0.3ppm, and then by the control group.
2) The plasminogen activator (PA) released from alveolar macrophages was increased dosedependently by NO₂ exposure. The activities were significantly high in the groups exposed for 10 to 20 days at each concentration, and then slightly decreased at 30 days. Thereafter, activity showed a tendency to increase, reaching the maximum level on the 60th day of exposure.
3) Similarly, the fibrinolytic activity in the lavage fluid was increased dose-dependently by NO₂ exposure. The maximum activity was noted on the 10th day of exposure, followed by a rapid decrease up to the 30th day, and a slight rise again between the 60th and 90th day.
4) In the group exposed to 5.0ppm NO₂, total protein in the lavage fluid increased, and the elastase inhibitory capacity (EIC) per milligram of protein decreased. In the group exposed to 0.3ppm NO₂, however, no difference from the control group was noted.
These results revealed that the alveolar macrophages were affected and increased PA activity as a result of exposure to as little as 0.3ppm NO₂. This was shown to result in an increase of the fibrinolytic activity in the alveoli, leading to damage to the lung tissue. This evidence may explain the morphological findings of the appearance of emphysematous change in the lungs of rats exposed to low levels of NO₂. For the detection of the effect of NO₂ on the lung tissue, PA appears to be a more sensitive indicator than EIC.

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日本人が日常よく摂取している牛乳と魚介類(鰺)について,日本人を被験者としたこれらの動物性食品の消化吸収率およびエネルギー利用率に関するデータは,ほとんどないのでこれらの値を算出した。対象者は日本人青年4名である。最初の7日間を基礎食期,それに続いで牛乳および鯵のテスト期を各々7日間とした。実験期間中に排泄された糞と尿は,全量採取し分析に供した。基礎食期とテスト食期の成分の差によって,消化吸収率およびエネルギー利用率を算出した。以下はその結果である。
1) 蛋白質の消化吸収率は,牛乳97.3±4.1%,鰺は96.8±2.8%であった。
2) 脂質の消化吸収率は,牛乳96.7±1.9%,鰺は98.6±2.6%であった。
3) エネルギー吸収率は,牛乳96.3±3.0%,鰺は96.9±5.0%であった。正味エネルギー利用率は,牛乳92.5±2.9%,鰺は88.4±5.2%であった。
4) 食品100g当りの利用エネルギーは,牛乳57.4kcal,鰺152.9kcalであった。

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Recently, food intake in Japan has been characterized by an increase in fat intake, especially animal-fat intake and the maintenance of excess salt (sodium chloride) intake. It is generally accepted that the increase in fat intake is closely related to atherosclerosis, and excess salt intake is a high risk factor for the development of hypertension and cerebrovascular lesions. So far, in almost all reports, the increase in fat intake and excess salt intake have been studied independently, and there have been few reports on the combined effects of these two factors. Taking the above things into consideration, it would seem to be very interesting to investigate the effect of excess salt intake on lipid metabolism. In this paper, we studied the effects of excess salt intake on lipoprotein and apolipoprotein metabolisms, using stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Kyo: Wistar rats (WKY) as model animals.
The results obtained were as follows:
A significant increase in the concentration of serum total cholesterol (TC) was observed in SHRSP and WKY, when the rats were given a regular diet (CE-2, Clea Japan Inc.) and 1% sodium chloride solution (1% NaCl) as drinking water for 4 weeks. This was accompanied by a tendency toward increases in the concentrations of serum apolipoproteins in both strains. These results suggest that excess salt intake could accelerate the production of serum total lipoproteins in SHRSP and WKY, when the rats are fed a regular diet.
Next, 1% NaCl and a high-fat and high-cholesterol diet (HFC diet) were simultaneously given to SHRSP and WKY for 6 weeks. The effects of simultaneous administration on lipoprotein and apolipoprotein metabolisms were compared with those of HFC feeding. One percent NaCl did not markedly affect hypercholesterolemia in WKY, while it induced more marked hypercholesterolemia in SHRSP that was associated with extreme elevations of serum TC and the atherogenic index (A.I.).
This deleterious effect of 1% NaCl in SHRSP was due to drastic elevations of cholesterol contents in the very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL) and low density lipoprotein (LDL) fractions. This was also associated with marked increases in apo B contents in the VLDL, IDL and LDL fractions and significant increases in apo E contents in the VLDL and IDL fractions. These results indicate that 1% NaCl induced much larger increases in serum atherogenic β-lipoproteins in SHRSP. In other words, hypertension of SHRSP may promote the deleterious effect of 1% NaCl on lipoprotein metabolism.
In the high density lipoprotein (HDL) fraction of SHRSP, the effect of 1% NaCl was not so marked, although a significant decrease in apo A-IV content was observed. In the lipoprotein-free fraction of SHRSP, apo A-I, apo A-IV and apo E contents were markedly elevated by 1% NaCl administration, but the mechanism was not clear and is now under investigation.
It is also very important to keep in mind that renal disorders such as renal failure or nephrotic syndrome possibly caused by 1% NaCl administration and/or hypertension occasionally have secondary effects on lipoprotein and apolipoprotein metabolisms.

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Chlorpyrifos, an organophosphorus insecticide, has been used as a termite control agent since regulatory measures against the use of chlordanes were taken in September, 1986.
In this study the actual state of occupational exposure to chlorpyrifos of termite control workers was investigated.
The findings obtained were as follows.
The concentration of chlorpyrifos in the air (near the mouth) was about 10 times higher (1.7-2.3mg/m³) under the floor than the threshold-limit value (0.2mg/m³) proposed by the ACGIH and rose close to the threshold-limit value even above the floor. Regarding the performance of the absorption can of the mask, generally satisfactory results were obtained.
The adhesion of this compound to the work outfit was conspicuous during the spraying work under the floor, and it was often noted on the right forearm (12μg/cmcm²), on the left knee (10μg/cmcm²), on the right knee (9μg/cmcm²) and on the face (5μg/cmcm²). The rate of this compound penetrating through the work outfit amounted to an average of 40 percent, making it clear that a considerable amount of the compound penetrated the work outfit. Furthermore, direct adhesion of the compound to the neck was considered. These results suggested the dermal-exposure to chlorpyrifos of termite control workers.
This compound was detected, though the quantity was very small, in blood after work, which was definitely indicative of exposure at the time of termite control work.
The plasma cholinesterase activity in the termite control workers was within the normal range before the busy termite control season but fell off markedly when the full-scale termite control season set in. It is suggested that a decrease in plasma cholinesterase activity occurs due to chlorpyrifos exposure.

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