Histocytological specificities of adrenal cortex in the New World Monkeys, Aotus lemurinus and Saimiri boliviensis.

The New World monkey Aotus spp. (night monkeys) are expected for use of valuable experimental animal with the close species of Saimiri spp. (squirrel monkeys). Saimiri is known to show spontaneous hypercortisolemia, although few reports in Aotus. We compared basic states of blood steroid hormones and histological structure of the adrenal glands in two monkeys. Serum cortisol and ACTH levels were statistically lower in Aotus than Saimiri. Conversely, Aotus adrenocortical area showed significant enlargement, especially at the zona fasciculata. Electron microscopic observation at Aotus fasciculata cells revealed notable accumulation of large lipid droplets and irregular shapes of the mitochondrial cristae. These results suggest potential differences in cellular activities for steroidogenesis between Aotus and Saimiri and experimental usefulness in adrenocortical physiology and pathological models.

Bisphenol-A (BPA) affects reproductive formation across generations in mice.

To understand effects of Bisphenol-A (BPA) exposure on the reproductive organ across generations, we analyzed morphology of the uterus and ovary, and the methylation pattern of HOXA10 gene of the 2(nd) generation. Pregnant mice (F0) were treated with sc injection of BPA in sesame oil at various doses of 0-1,000 mg/kg Bwt on days 12-16 of gestation. Their offspring (F1) were bred by foster mice, and the offspring (F2) from F1 mice were prepared. That is, F1 mice experienced in utero BPA exposure during the developmental period of reproductive organs, while F2 mice did not at all. Using these F2 mice, the present study was carried out. Comparing to the control, the body weights in BPA exposure groups were significantly increased. Correlating with the increase of body weight, the relative weights of the ovary and uterus in each group were decreased. The histological analysis revealed expansion or emphraxis of the uterine lumen and partial loss of the uterine epithelium. Unmethylation of HOXA10 gene in the uterus was observed in the intron region. The present study suggested that BPA exposure to F0 mice could affect reproductive organ of F2 mice who were not exposed to BPA.

[Accuracy of volume measurement of lateral atlanto-axial joint by 3D-CT facet arthrograms].

In conventional 3D-CT image processing, the images are influenced by subjective threshold settings. The purpose of this study was to evaluate an objective threshold setting technique based on the discriminant analysis method. The concentration of contrast medium in a joint of a simulated upper cervical spine phantom was changed, and its threshold was measured from scanned data by using the discriminant analysis method, and mean CT attenuation was measured. On the other hand, an accurate image of the corresponding joint in the phantom was made, and its minimum threshold was measured. Regression analysis between the adjusted minimum threshold and mean CT attenuation of the region of contrast medium was performed. The obtained linear regression formula was applied to the threshold settings in five cases for atlanto-axial 3D-CT facet arthrogram(3D-CTF), and the accuracy of the images was examined. There was a strong correlation between the adjusted threshold and mean CT attenuation, and the obtained linear regression formula was y=0.625x-141(r2=0.991, p<0.01). This equation could be used clinically for correction of the threshold settings. We propose the following method for threshold setting of 3D-CTF: the threshold of the region of contrast medium is measured using the discriminant analysis method, then the adjusted minimum threshold for the threshold settings of 3D-CTF is calculated from mean CT attenuation. The method described herein is an objective, general-purpose methodology that is applicable to various types of 3D-CT.

Effects of bisphenol A (BPA) on placentation and survival of the neonates in mice.

The effects of bisphenol A (BPA) on placentation have not been fully determined. The aim of this study was to clarify the structural changes of the placenta, abortion rate, and survival of neonates after BPA administration in mice. BPA (10 mg/kg/day) was administered to pregnant mice (BPA mice) subcutaneously from the first day of pregnancy (Day 0) to Day 7 (8 days total). The number of embryos and weights of whole uteri were measured on Days 10 and 12. Morphological changes in the placentae were examined by light microscopy on the corresponding days of pregnancy. The number of neonates was also counted. Survival rates were periodically calculated for neonates from the first day after parturition (P-Day 0) to P-Day 56. The number of embryos and weight of the uterus on Days 10 and 12 were significantly decreased by BPA injection. No notable differences were recognized between the left and right uteri. The proportion of the labyrinthine zone per whole placenta in the BPA mice became lower than that in the controls, and that of the metrial gland was higher in the BPA mice. The intervillous spaces of the placenta were narrower in the BPA mice. Degenerative changes were found in the trophoblastic giant cells and spongiotrophoblast layers of the BPA mice. The number of BPA mouse neonates was drastically decreased within 3 days after birth, and no mice survived after P-Day 56. The results suggest that BPA not only disrupts placental functions and leads to abortion through chronic stimulation of gene expression by binding to DNA but that it also affects the mortality of neonates through indirect exposure of embryos.