Metallothionein (MT) is a low-molecular weight metal-binding protein. Although the physiologic function of MT is not fully known, it is present in various species and various organs including the skin. MT is strongly stained in hyperplastic epidermal tissues in normal skin and in hyperplastic skin lesions, and increased expression of mRNA of the MT gene has been demonstrated in skin stimulated by proliferative agents, suggesting that MT is involved in the proliferation of epidermal keratinocytes. To improve our understanding of the role of MT in epidermal hyperplasia, mice with null mutations in their MT-1 and MT-2 genes were used in this study. We compared the epidermal hyperplasia in MT-null mice and in normal C57BL/6 J mice after treatments with cholera toxin, 12-0-tetradecanoylphorbol-13-acetate, and ultraviolet B irradiation, which stimulate epidermal proliferation. Immunostaining of MT was not detected in the skin of MT-null mice, and these mice developed significantly less epidermal hyperplasia than the normal mice after exposure to each stimulator. We determined the metal contents of skin samples by the proton-induced x-ray emission method. The zinc content of the skin of the MT-null mice was lower than that of the control mice before stimulation. After stimulation of epidermal hyperplasia, MT-null and normal mice showed significantly reduced levels of zinc. These findings indicate that cellular MT is involved in the proliferative process of the epidermis induced by cholera toxin, 12-0-tetradecanoylphorbol-13-acetate, and ultraviolet B light through its regulatory action on the metal metabolism required for cell growth.

The authors investigated the condition of self-physique perception and eating behavior, and the relationship between self-physique perception and eating behavior of high school students in Japan. Regarding self-physique perception, subjects were shown six pictures of physiques and asked to choose one physique each for their actual physique and their ideal physique. With respect to eating behavior, the Japanese version of the Eating Attitudes Test (EAT)-26 was used. Groups of underweight girls, normal girls, and normal boys tended to regard their actual physiques as rather broad, demonstrating that many girls are excessively preoccupied with thinness. The rate of eating problems was 11.2% for the girls and 2.4% for the boys. For both boys and girls, those who idealized the thinner physique scored higher in terms of the EAT score and factor I score. Education regarding body perception and diet must be undertaken as soon as possible in Japan.

Copper (Cu) distribution in various organs of brindled mice (BM), an animal model of Menkes disease, was studied histochemically and by atomic-absorption-spectrophotometry 7 months after Cu injections. The results were compared with those of untreated BM. In the treated BM brain, a diffuse reduction in Cu-related staining of neurons and astroglia was still evident, though it had improved to some extent. The reduction was noticeable in the thalamus, brain stem and cerebellum, although intensely stained capillaries were noted occasionally in the retrosplenial and mediobasal temporal areas, including the hippocampus. In the treated BM liver, near normalization of Cu distribution was observed. In the treated BM intestine, the main localization of Cu accumulation was in histiocytes/macrophages in the lamina propria, while in the untreated BM it was in the absorptive and secretory epithelial cells. In the treated BM kidney, there was no clear improvement in Cu distribution. These histochemical results were consistent with the data obtained by the spectrophotometric assay. Electron microscopic histochemistry of affected renal tubular epithelial cells revealed numerous silver grains, which represent Cu++ localization, distributed only within the cytoplasm outside organella and nucleus. This suggests impaired intracellular Cu transport from cytosol to organella, which in the kidney is refractory to the Cu therapy adopted.

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In recent years, the effects of smoking and excessive alcohol consumption on immune function have been studied, due to a high prevalence of infection or cancer in heavy drinkers, and the combination of smoking and drinking was considered to be a carcinogenic risk. However, the effect of smoking and drinking on systemic immune function has yet to be clearly understood. In this study, we investigated neutrophil functions (reactive oxygen species (ROS) productive activity, phagocytic ability and serum opsonic activity) and their relationship with alcohol consumption or amount of smoking. In total there were 731 male and female adult subjects who participated in the Iwaki Health Promotion Project in 2005. Multiple regression analysis showed a trend of increased ROS production in male subjects and a statistically significant decrease was observed in phagocytic activity caused by smoking in female subjects. In other words, oxidative stress caused by smoking in male subjects may be involved in ROS production from neutrophils. Decreased phagocytic activity of neutrophils caused by smoking suggests that host defense functions were impaired in female subjects. A relationship between neutrophil functions and the amount of alcohol consumption was not observed.