Cyanofenphos, O-ethyl O-4 cyanophenyl phenylphosphonothioate (CYP), is one of the delayed neurotoxic organophosphorus insecticides. The effect of repeated pretreatment by small dosages of CYP on delayed neurotoxicity (DNT) from subsequent large doses (100mg/kg-1600mg/kg) of CYP itself as a challenge dose was investigated in hens. Most of the hens given preliminarily 10mg/kg/day of CYP (1.9% LD 50) for 8 days survived the acute toxicity of a subsequent challenge dose of CYP, while many hens given only the challenge dose died of acute intoxication. The hens pretreated for 8 days showed significantly intensified DNT, compared with the other 2 groups of hens, the non-pretreated group and the atropinized group, after each challenge dose unless the amounts of CYP-challenge doses were more than 800mg/kg. The pretreatment by small doses of CYP intensified the DNT from subsequent challenge doses of CYP more effectively in the case where small doses of CYP were pretreated repeatedly for several days than in the case where the same amount of the pretreatment in total was given at once. The intensifying effect of DNT could not be observed clearly by repeated pretreatment of leptophos.
These results suggest that repeated pretreatment by small amounts of delayed neurotoxic organophosphorus insecticides make it possible to subsequently administer a large amount of the same insecticide to hens as a challenge dose without atropinization, and also make it easy to observe DNT of organophosphorus insecticides which show relatively strong inhibition of ChE activity. The results also give warning that persons who are exposed repeatedly to low levels of CYP may be affected by more severe neuropathy than usual if they accidentally receive a high level of CYP exposure.

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A surveillance system for gathering and analyzing working environment measurement records as well as the medical examination records kept in most workplaces every year has been implemented. To these records, the system planners added medical certificate data presented to workplaces when the workers take sick leaves for more than a fixed period of time, usually over 7 days stipulated in the enterprise regulations. The types of medical problems on the medical certificate forms are transformed into numerical codes based on the International Classification of Diseases (I. C. D.), and a frequency order of medical problems, an average of the absent days and mean age of each problem are acquired.
It was observed that the most frequent problem was due to injuries, followed by digestive ulcers, spinal disorders and respiratory diseases. Three months and 10 days, for unspecified tumors and respiratory diseases respectively, different periods of absent time for each problem and 35 days of total problems were ascertained. Hypertension and spondylosis were high on the average due to age and threatened abortion the lowest conversely. In addition, 4 clusters of workplaces are classified by the cluster analysis employing absent rates of specific disease groups and are explicated for various aspects due to the results of chi square test.
Characteristics of the 4 disease group patterns of clusters are as follows.
1) Pattern I, including 67% of the workplaces and displaying a pattern of low level controlled absent rates with all disease groups, has a distinctive feature in that the woman worker's ratio is higher than the average and the work environment is rather good.
2) A small number of workplaces, Pattern II, shows an interesting pattern of frequent tumors and cardiovascular diseases. It contains many minor workplaces on the scale, with a large amount of the enterprises in the wood-making and ceramics industry.
3) It was found that large-scale workplaces like the transport machine industry can be classified into Pattern III which has the high absent rates due to mental disorders and piles.
4) The workplace of Pattern IV indicating a bad condition in the working environment measurement shows a relatively high absent rates for most disease groups.

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Immunological abnormality in 14 patients with asbestosis was investigated for natural killer (NK) cells from peripheral blood mononuclear cells (PBMC) and interferon (IFN). There were 7 males and 7 females (mean age 61 years; range 42-73 years) who were free of complications such as tuberculosis, carcinoma, or steroid therapy. There were 4 cases of type 1 and 10 cases of type 2 as described in the ILO pneumoconiosis classification. They are all textile workers with a mean duration of 17 years (3-30 years) since the first exposure to chrysotile. Controls matched by age and sex were selected from a population without occupational exposure to asbestos. NK cell activity in the patients with asbestosis was significantly lower than in the controls. But the population of NK cells in PBMC showed no significant differences for the two group. Exogenous IFN enhanced NK cell activity of controls and 3 patients with asbestosis, while it did not enhance activity in 7 patients. Furthermore, PBMC from controls and patients with asbestosis produced IFN-α type after stimulation with Sendai virus. The results were that IFN-α levels in patients with asbestosis were significantly higher than those of the controls. The number and mechanism of suppressor T cells in patients with asbestosis showed no significant difference when compared with the controls. These findings may indicate evidence that links fundamental disturbances of body defence mechanism in patients with asbestosis.

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4, 6-Dichloro-7-(2, 4, 5-trichlorophenoxy)-2-trifluoromethylbenzimidazole (DTTB), which was used as a mothproofing agent in wool fabrics, was quantitatively determined by high performance liquid chromatography using an ultraviolet spectrophotometric detector. DTTB was extracted with diethyl ether from a 10% sodium hydroxide solution of wool fabrics. The extract was cleaned up by the use of SEP-PAK C₁₈ cartridge with acetonitrile-dilute aqueous ammonia (1/2, 000) (1:2) as an eluant. The eluant was concentrated and dissolved in ethyl alcohol containig anthracene as an internal standard. DTTB was separated on a column packed with LiChrosorb RP-18 by the use of acetonitrile-0.0087M acetic acid and 0.0013M ammonium acetate in water (3:1) as the mobile phase, with detection at 220nm. The calibration curve was linear in the range from 1ng to 80ng. The limit of detection was 1ng of DTTB and 0.4μg/g in samples. The recoveries of DTTB added to diethyl ether extracts from socks and neckties were 97.2-99.5% and 97.4-98.9%, respectively.

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Pregnant females of the guppy, Poecilia reticulata were subjected to 10ppm of fenitrothion for four hours. Exposure of the guppy to the chemical were made 5, 10 or 15 days before the next parturition. Half of the females experienced premature birth when exposed 5 or 10 days before parturition, and only 32.2 or 63.3% of the eggs were delivered alive respectively. The females exposed to the fenitrothion 15 days before parturition had a normal birth and only 9.4% of the offspring were stillborn. Body lengths of young produced by the females after exposure were significantly shorter than those before exposure in all the experiments.

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To investigate the possible individual differences in response pattern of the autonomic functions to sound stimulation, simultaneous measurements of the heart rate (HR) and plethysmogram (PLT) from the index finger were performed when bell-sound bursts were presented irregularly as well as regularly.
The subjects were 3 healthy male students, ages 19, 19 and 22 years. They were exposed to 3s long bell sound bursts (91.5dBA) presented regularly with intervals of 150s and irregularly with random from 90 to 150s in an insulated room with the background sound level under 30dBA inside. Both of the regular and irregular sessions consisted of 5 blocks of 5 exposures as above. The intervals between blocks were 5min. The irregular session was conducted one week after the regular one.
ECG (chest lead, V4) records from -3 to 30s after each 3s long burst were divided into eleven 3s records, and mean HR was calculated from the mean R-R intervals included completely within each 3s record. In the same manner, mean finger-top plethysmogram amplitude for all the complete waves within each time period of 3s before, during and after each bell sound burst were calculated. However, all the responses were examined as percent changes to the pre-exposure 3 s-long values in all the cases.
The results of HR responses to sounds showed such great intra- and inter-individual variations that any consistent trends like habituation (gradual decrement of responses with repetition of stimuli) could not be observed. Only in block 1 of the regular session in Subject 1, consistent and typical HR responses were found, which showed rapid tachycardia followed by bradycardia. On the other hand, PLT showed consistent and significant responses especially in the regular session as shown in the figures. Decremental process of the minimum peaks or habituation with repetitive stimulations from block 1 to 5 in the regular session was obvious in Subject 1 and 3, whereas in Subject 2, on the contrary, the minimum peaks increased with repetition of the stimulations.
Thus, individual differences in response patterns of the autonomic nervous system functions were confirmed to be possible, which may cause great intra- and inter-individual variation in the autonomic functions especially when only one measurement like HR is adopted as a parameter. However, one cannot deny that a subject, who does not respond in HR to sound, may be significantly susceptible to the same sound in another aspect like peripheral circulation. Therefore, further study is needed to clarify such subtypes of the autonomic functions to investigate the physiological effects of noise as well as to use sound stimulation in a test of the autonomic functions. It should also be noted that habituation or sensitization could be significantly observed in some of the autonomic functions, only if sounds are presented regularly.

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The effect of a single dose of pentachlorophenol (PCP) was studied in fasted male Wistar rats. A marked depletion of hepatic glycogen and a significant increase of blood sugar were observed 3 hours following administration. In contrast, prolonged PCP treatment induced remarkable glycogen storage of more than 10 times the fasted control level.
The enzymatic studies suggested that the early depletion of hepatic glycogen was caused by a stimulation of phosphorylase activity, which, in turn, resulted in elevation of blood glucose. Hepatic glycogen storage due to PCP at a later stage could be attributable to the acceleration of glucose-6-phosphate-independent (I) form of liver glycogen synthetase.
Enhancement of adrenocortical activity observed in the early stage suggested that adrenocortical hormone plays a role in the initial fall of hepatic glycogen due to PCP.

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