The effects of di-isopropylnaphthalenes (KMC) and 1-phenyl-1-xylyl-ethanes (SAS) were examined in rats. The rats were administered 0.1 g of the substances per kg of body weight every day for a month. The substances were given directly into the stomach with a syringe. At about 2 hours efter receiving the final dosage, the rats were killed and examined biochemically. An increase in liver weight, disturbance of lipid metabolism in the liver and serum and disturbance of glucose metabolism in the liver were observed after the administration of KMC-A and SAS-296. A significant increase in alkaline phosphatase activity in the serum was noted only in the case of SAS-296 administration. A decrease in kidney weight was observed only after KMC-A administration. The results obtained in these animal experiment have clear implications for the health examination of workers who come in contact with KMC or SAS.
This is a case report on acute intoxication caused by exposure to m-dinitrobenzene (DNB) that occurred in 1969 in our country. Six workers involved in the intoxication used hammers to remove the DNB crystal layer from the sur-face of an accidentally overflowed tank and were probably exposed to a large amount of DNB dust. The workers developed cyanosis which was followed by a slight to moderate anemia, viz 1.9-15.5% loss in specific gravity of the whole blood (GB). The magnitude of the anemia was not so different from those reported previously4), but prolonged recovery from the anemia was a characteristics of the intoxication cases of the present report. All the workers exposed to the chemical had been followed for ten years and it was confirmed that there was no long term adverse effect being attributable to the exposure.
Workers exposed to dye intermediate, benzanthrone, develop itching, burning sensation, erythema and hyperpigmentation of the skin; which also becomes tender, rough and peals off easily. Earlier experiments have shown that rat skin is capable of picking up benzanthrone. The present study was, therefore, aimed to explore the binding kinetic of skin matrix, of which collagen shares the major proportion. Results revealed that benzanthrone readily binds to reconstituted native collagen fibrils. The uptake is concentration dependent initially and does not in-volve-SH groups. Denaturation (gelatinisation) of collagen by heat or urea treat-ment leads to loss of its binding potential. Serum albumin exhibits a tendency to dissociate benzanthrone prebound to collagen and thus may ultimately assist in efflux of benzanthrone through circulation.
A histopathological examination was made of adult male rats which inhaled 1, 2-dibromo-3-chloropropane (DBCP). The rats were continuously exposed to 10 ppm DBCP for 14 days and were sacrificed 1, 16 and 36 days, and 12 months after exposure. Severe injury was produced in the testicle, kidney and lung. The testicle became completely atrophied with irreversible aspermatogenesis. The renal injury was characterized by proximal tubular necrosis in the outer medulla. In the lung, necrosis and cytomegaly were observed in the bronchial and bronchiolar epithelial cells as well as the alveolar emphysema. In another experiment, adult male rats were exposed to 0, 0.3, 1, 3 and 8 ppm DBCP continuously for 14 days. The testicle was examined 1 and 15 days after exposure, revealing pathological changes in the 3 and 8 ppm exposure groups, with recovery and a progressive course, respectively.
Blood electrolyte levels were studied in 95 workers of a synthetic fibre plant, exposed for up to 25 years to carbon disulphide (CS2) at relatively low air concentrations. In the group of workers exposed up to five years increases in the plasma sodium and chlorine levels and decreases in the erythrocyte potassium and calcium level as well as decreaeses in the calcium transmembrane gradient, in the calcium/magne-sium ratio in both blood compartments and in the calcium/phosphorus ratio in erythrocytes were found. Exposure to CS2 for over ten years caused a slight increase in the plasma potassium and a decrease in the plasma calcium levels, a decrease in the sodium transmem-brane gradient and an increase in the potassium/calcium plasma ratio. In workers exposed to CS2 from six to ten years, the blood electrolyte charac-teristics were, in some respects, similar to those in workers with shorter, while in others, to those in workers with longer exposure. Those findings refer only to mean group values of the above mentioned parameters. The individual blood electrolyte values were excessively variable. Because of this variability blood electrolyte levels cannot be recommended as laboratory signs of chronic CS2 effects.
The penetration rates of 10 hydrophobic solvents through the excised abdominal rat skin were quantitatively determined by using the in vitro method reported previously. The hydrophobic solvents studied were benzene, toluene, ethyl-benzene, o-xylene, styrene, n-pentane, 2-methylpentane, n-hexane, n-heptane and n-octane. There was a great diversity in the ability of the hydrophobic solvents to penetrate through the excised rat skin, but a good correlation between the penetration rates and the solubility of the solvents in water was observed. The log-log plot of the penetration rate versus the solubility in water showed a linear relationship ; log y=1.41 log x-0.297, r =0.981, where y is the penetration rate (n moles/min/cm2 of skin) and x is the solubility of the solvent in water (mM at 25°C). The solubility in water was found to be a reliable index of the skin penetration rate for the hydrophobic solvents.
Sixty female rats were divided into 4 groups. The diet for group I was supplemented with 200 pg Cd per g diet and that for group II was supple-mented with 200 pg Zn per g diet and to the diet for group III were added 200 pg Cd and 200 pg Zn per g diet. Group IV was the control group fed normal diet. They were sacrificed at 11th, 26th and 40th week of exposure. Cd content in the liver of the rats exposed to Cd alone (group I) was higher than that of the rats exposed to Cd-F Zn (group III) at 26th and 40th week of exposure. Metallo-thionein (MT) concentration in the rats of group I was consistently higher than that of group III. At 40th week of exposure, MT fraction in the sephadex G-75 elution profile of group I showed a definite shoulder and this shoulder was not observed in the rats of group III. Pathological changes were observed in the liver of group I but not in group III. Present results suggest that the formation of additional molecular species of Cd containing protein is associated with Cd-induced hepatic damage.
The coil planet centrifuge (CPC) test, a sensitive method for detecting minute changes in osmotic fragility of red blood cells (RBC), was applied to 788 forest workers in parallel with the conventional health examination for vibration hazards. Although the RBC of the examinees with or suspected of vibration hazards tend to be osmotically more resistant than the RBC of healthy subjects when evaluated on a group basis, comparison of the results between the CPC test and the vibration hazard examination disclosed that the changes are not remark-able enough to identify the affected individuals from the mass of the non-affected. Thus, the validity of the CPC test as a screening measure to detect the earliest signs of vibration hazards appears to be rather limited, even though this conclusion does not necessarily rule out the possibility that positive changes in CPC findings might be observed in severe cases of vibration hazards.