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A novel antimitotic compound named Nostodione A (Nd A) was isolated from a terrestrial blue-green alga Nostoc commune. Nostodione A disturbed the mitotic spindle formation of sea-urchin eggs and gave small spindles with low birefringence density. Nostodione A. how­ever, had no phytotoxicity on the germination of a dicotyledonous plant Medicago sativa. Based on the spectral analysis and chemical degradation, the structure of Nostodione A was elucidated

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Skin sensitization resulting in allergic contact dermatitis is a common occupational health issue. In this study, the effect of mixing two skin sensitizers on the skin sensitization response was investigated. Skin sensitizers are generally classified into T helper type 1 (Th1) or T helper type 2 (Th2), depending on the induced cytokine profile. Dinitrochlorobenzene (DNCB) and oxazolone (Oxa) are Th1 skin sensitizers and phthalic anhydride (PA) and toluene diisocyanate (TDI) are Th2 skin sensitizers. We investigated the effect on skin sensitization response to mixtures of three pairs of these sensitizers: DNCB and Oxa, DNCB and PA, and PA and TDI, using guinea pig maximization test and mouse ear swelling test. In guinea pigs sensitized with the mixture of DNCB and Oxa or PA and TDI, there were changes of skin sensitization response to DNCB and Oxa, and that to PA. On the other hand, there was no mixture effect in guinea pigs sensitized with the mixture of DNCB and PA. The skin sensitization responses were decreased in mice sensitized with the mixtures of DNCB and Oxa or PA and TDI, whereas the mixture effect was not observed in mice sensitized with the mixture of DNCB and PA. The present findings revealed that mixture effect on the skin sensitization response was observed after simultaneous exposure to two skin sensitizers, and the effect was determined by combinations of mixed skin sensitizers.

The aim of the present study was to develop a quantitative evaluation method for detecting antiandrogenic activity of chemicals in rabbits that are regularly used for developmental toxicity studies. Kbl: New Zealand White rabbits (n = 8-9) were injected intramuscularly with an antiandrogen, cyproterone acetate (CA; 10 mg/kg body weight [BW]/day), on gestation days (GD) 13-24. On GD 29, live fetuses were obtained by cesarean section and sexed by examination of the internal genitalia. The external genitalia were evaluated in cross-section measurements of the phallus by both diameter and width of the ventral gap of the preputial lamella with a micrometer under a stereoscopic microscope. The diameters of the preputial lamella were 1015 Ϯ 83.5, 856 Ϯ 64.0, and 865 Ϯ 72.6 mm in control males, control females, and CAtreated males, respectively. The ventral gaps of the preputial lamella were 26 Ϯ 8.2, 437 Ϯ 72.3, and 318 Ϯ 59.4 mm in the control males, control females, and CA-treated males, respectively. There were statistically significant differences in both parameters between control males and control females or CA-treated males. The lower fetal BW in CA-treated males did not disturb the detection of the feminization of the ventral gap of the preputial lamella; however, the diameter of the preputial lamella might be influenced by fetal BW because no difference in the relative diameter of the preputial lamella was found between control males and CA-treated males.These results demonstrated that this approach could detect the antiandrogen activity of CA quantitatively by feminization of male external genitalia in rabbit fetuses.