The formation of the epicardium was investigated in the mouse embryo using scanning electron microscopy (SEM) in order to establish a three-dimensional perspective concerning epicardial development in mammals. The epicardium first appears as aggregates of cells scattered on the caudal surface of the ventricle and atria where these regions face the septum transversum in a 9-day-old embryo. These aggregated cells seem to have originated from the mesothelial projections extending from the surface of the septum transversum. Then, the cells of each aggregate flatten, subsequently fusing with each other to form a continuous sheet of epicardium. The fusion of aggregates proceeds in a cranial direction. Finally, the bulbus cordis and truncus arteriosus become invested by migrating cells at the cranial end of the epicardial sheet about 11 days after fertilization. The present observations are discussed in comparison with those made previously in avian embryos.

If the risk of FA in gross anatomy laboratories is assessed based on the indoor FA levels, the possibility that personal exposure levels are 2 to 3-fold higher than the mean indoor FA level should be taken into account. Otherwise, the risk should be assessed based on the personal exposure levels. However, it is hard to measure everyone's exposure level. Therefore, further studies are necessary to develop a method of personal exposure assessment from the indoor FA concentration.

Variations of the extensor indicis muscle were examined in 164 hands from 86 Japanese cadavers. Anomalous cases exhibiting supernumerary muscles or tendons were found in 22 hands. These variations were classified into four types: type 1, an additional tendon slip from the extensor indicis tendon; type 2, an extensor indicis radialis or extensor pollicis et indicis accessorius; type 3, an extensor medii proprius with or without extensor medii brevis; and type 4, an extensor indicis radialis and extensor medii proprius. The extensor medii proprius was the most common variation, followed by extensor indicis radialis. There were no clear differences in incidence of variations between men and women or between right and left hands. When variations were bilateral, both sides were identical or similar in type.

Abstract.We investigated the long-term estrogenic influence of genistein on the male reproductive system in mice. Newborn ICR male mice were treated with genistein (10, 100, or 1000 , tg/mouse) for neonatal 5 days. As positive control, administration of diethylstilbestrol (0.5-50 pg/mouse) was carried out. In mice exposed to genistein,we examined weight of testes, sperm counts, sperm motility, and mRNA expression levels of estrogen receptor a (ERa) and androgen receptor (AR) at 4, 8 or 12 weeks after birth. Moreover, at 12 weeks of age, we evaluated protein level of ERa. In our conventional reproductive-toxicological study (weight of testes, sperm counts and sperm motility), neonatal transient exposure to genistein did not show adverse effects on the male reproductive system in 4, 8 or 12 week old mice. However, in mice treated with genistein mRNA expression levels of ERa and AR were reduced at 8 weeks. This reduction was recovered at 12 weeks in mice treated with a lower dose (10 ICg) of genistein but not in those with higher doses (100 pg and 1000 rig). In addition, ERa protein levels tended to decrease in 12 weeks of adulthood.Our results exhibited that the disruption of gene expression continued for long term such as 3 months after administration of genistein, even if no effect was found at conventional reproductive-toxicological level. We have shown that neonatal administration of weak estrogenic compound (genistein) affects male reproductive organs at molecular levels in adulthood.