Fetal exposure to phytoestrogens--the difference in phytoestrogen status between mother and fetus

The goal of this study was to investigate fetal exposure to phytoestrogens, estrogenic compounds derived from plants, by measuring serum concentrations of phytoestrogens in maternal and cord blood. This study included 51 mothers scheduled for cesarean section (C-section), to obtain the serum of mother and fetus at almost the same time. Serum concentrations of phytoestrogens, including genistein (Gen), daidzein (Dai), coumestrol (Cou), equol (Equ; a metabolite of Dai), and sulfate-conjugated Gen, were measured in maternal and cord blood samples by LC-MS/MS and HPLC. It was found that phytoestrogens were transferred from mother to fetus. The detection rates of Gen, Dai, Equ, and Cou in cord serum were 100%, 80%, 35%, and 0%, respectively. Levels of Gen and Dai were higher in cord than in maternal serum (mean=19.4 ng/ml vs.7.2 ng/ml and 4.3 ng/ml vs.1.8 ng/ml for Gen and Dai, respectively). However, a reverse pattern was seen for Equ (cord mean=0.9 ng/ml, maternal mean=2.0 ng/ml). The correlations were significant between the concentration levels of Gen and Dai, Gen and Equ, and Gen and Dai plus Equ in cord serum. However, in maternal serum, the correlations were weak. Also, in 8 of 10 cord serum samples, sulfate-conjugated Gen was detected (mean=5.2 ng/ml, standard deviation=4.7), but it was detected from only one maternal serum (8.7 ng/ml). This study demonstrates placental transfer of phytoestrogens from mother to fetus. It is suggested that the metabolic and/or excretion rates of phytoestrogens are different between mother and fetus and once phytoestrogens are transferred to the fetus, they tend to stay in the fetal side longer than in the maternal side. While the implications for the health and development of the newborn are not known, these data suggest that the effects of fetal exposure to phytoestrogens should be studied further.     

Lhermitte's sign in alcoholic myelopathy without portosystemic shunting: MRI evaluation

We conducted spinal MR imaging on a 35-year-old man with Lhermitte's sign that had manifested over the previous 4 years. He had consumed more than 500 ml of whisky daily for at least 10 years. However, he did not show any evidence of severe liver disease with hepato-systemic blood shunting. Neurologic examination revealed markedly depressed sense of vibration in the feet and mild spasticity in the lower limbs, together with Lhermitte's sign. MR imaging revealed abnormal signal intensity in the posterior column spanning the whole length of the upper cervical cord, which is consistent with Lhermitte's sign.     

Elevated cyclooxygenase-2 expression is associated with histological grade in invasive ductal breast carcinoma

PURPOSE: The aim of this study was to evaluate the expression of cyclooxygenase-2 in human breast cancer using immunohistochemistry and to determine whether the expression of cyclooxygenase-2 is associated with clinicopathological factors in invasive ductal breast carcinoma. METHODS: Cyclooxygenase-2 expression was investigated by immunohistochemistry in 30 invasive ductal breast carcinoma specimens and relationships between cyclooxygenase-2 expression and age, histological grade, histological type, nodal status, and hormone receptor status were evaluated. RESULTS: Cyclooxygenase-2 expression was found in 56.7% of the tumor samples and was related to histological grade (P<0.01) and histological type (P<0.001). CONCLUSIONS: Our results suggest that cyclooxygenase-2 expression has an important role in tumor differentiation in invasive ductal breast carcinoma.     

Biochemical and immunohistochemical studies on dysmyelination of quaking mutant mice in vivo and in vitro

Dysmyelination in the central nervous system of the quaking mutant mouse was studied biochemically and immunohistochemically. We found, by measuring CNPase activity, that myelination in the central nervous system of quaking mice was affected to a different degree in different areas. The pallium cerebri was the most severely affected and the medulla and spinal cord were least affected. The density of astroglia observed by GFA staining wash higher in the white matter of quaking mice than in controls, but the total area of the white matter in the cerebellum was smaller in the quaking mice than in the controls. The DNA content in the pallium cerebri and brain stem showed no increase and that of the cerebellum was even lower in quaking mice than in the controls. Hypertrophy of the astroglia was observed in the white matter of the cerebellum of quaking mice, though Bergmann astroglial fibers in the molecular layer did not show any hypertrophy. The cerebella of quaking mice in primary culture showed very poor myelination under the phase-contrast microscope. However, Purkinje cells from the quaking mutants appeared normal with regard to Bodian silver impregnation, hematoxylineosin staining, and Purkinje cell specific P 400 protein. Addition of the conditioned culture medium of qk/qk to the culture of the control cerebellum did not interfere with the myelination. We concluded that the cause of dysmyelination in the quaking mouse could be a genetic defect of the oligodendroglia rather than hypertrophy of the astroglial cells.     

Detection of ehrlichial DNA in small rodents captured in a woodland area of Hokkaido, the northernmost island of Japan, where Lyme disease is endemic

The ehrlichial gene was detected in small rodents trapped in a Lyme disease-endemic area in Hokkaido, the northernmost island of Japan. Primer pairs of 16S rDNA targeting the genus Ehrlichia and other regions of the 16S rDNA specific for E. chaffeensis and E. muris were used for identification. The DNA fragment specific for 16S rDNA of Ehrlichia spp. was detected in 4 of 94 Apodemus speciosus mice (positive rate: 4.3%) and 5 of 73 Clethrionomys rufocanus bedfordiae mice (positive rate: 6.8%). The nucleotide sequence of the amplified 16S rDNA fragment was most similar to those of E. muris-like Ehrlichia, Ehrlichia spp. HF565 and Shizuoka-36, originating in the northern and central parts of Japan. In phylogenetic analysis based on 16S rDNA sequences, the northern, central and western groups of E. muris-like Ehrlichia from a cluster with microorganisms of the E. muris group. These results suggest that there are a group of E. muris microorganisms and a group of E. muris- like microorganisms in Japan.     

Subcellular localization of glucose transporter 4 in the hypothalamic arcuate nucleus of ob/ob mice under basal conditions

Glucose transporter (GLUT) 4 plays an important role in insulin-induced glucose uptake in skeletal muscle and white adipose tissue. Although GLUT4 is abundant in the hypothalamus as well as in these peripheral tissues, little is known about the role of GLUT4 in the hypothalamus. In this study, we examined the subcellular localization of GLUT4 and the activation of insulin signaling pathways in the hypothalamic arcuate nucleus of ob/ob mice under basal conditions. The expression of GLUT4 in the arcuate nucleus of ob/ob mice was higher than that in lean mice. Interestingly, GLUT4 on the plasma membrane increased significantly in neurons of the arcuate nucleus of ob/ob mice when compared to that in lean mice. Because serum insulin levels of ob/ob mice were very high, we hypothesized that insulin strongly stimulates GLUT4 translocation in the arcuate nucleus of ob/ob mice. Unexpectedly, tyrosine phosphorylation of IR and insulin receptor substrate-1 (IRS-1) was faint in the hypothalamus of lean and ob/ob mice. In addition, phosphorylation of IRS-1 at Ser307 in the hypothalamus of ob/ob mice was higher when compared to that in lean mice, suggesting that insulin signaling is impaired by phosphorylation of IRS-1 at Ser307 in the hypothalamus of ob/ob mice. However, serine phosphorylation of Akt in the arcuate nucleus of ob/ob mice increased significantly when compared to that in lean mice. Furthermore, the expression of brain-derived neurotrophic factor, an activator of PI3K-Akt pathway in neurons, increased significantly in the ventromedial hypothalamus of ob/ob mice. We discuss the possibility of novel pathways which induce the translocation of GLUT4 in the arcuate nucleus of ob/ob mice.     

Cloning and characterization of three PHEX homologues in <Emphasis Type="Italic">Drosophila</Emphasis>

Inactivating mutations and/or deletions of PHEX (Phosphate-regulating gene with Homologies to Endopeptidase on the X chromosome) are responsible for X-linked hypophosphatemic rickets in humans. In the present study, three Drosophila PHEX homologues (dPHEX-1, -2, -3) were isolated by the screening of a Drosophila cDNA library and expressed sequence tag (EST) database. The structural region involving motif II: ⁴⁵⁶WMXXXTKXXAXXK⁴⁶⁸ (numbered according to human PHEX), motif VI: ⁶⁰²WW⁶⁰³, and motif VIII: ⁷⁴⁶CXLW⁷⁴⁹ was conserved in the dPHEX family. Zinc-coordinating motifs (HEFTH and GENIADNGG) were also conserved in the dPHEX family. All three dPHEX genes were expressed during all stages of Drosophila development. The expression of dPHEX-1 was suppressed by dietary phosphate deprivation, but the expression of dPHEX-2 and that of dPHEX-3 were not affected. In-situ hybridization showed a ubiquitous distribution of dPHEX-1 and dPHEX-2, while dPHEX-3 was highly expressed in the larval brain. In an analysis of subcellular localization, dPHEX-1 was localized to intracellular organelles and dPHEX-3 was localized predominately in the plasma membrane of Drosophila embryonic S2 cells. Homozygosity of a dPHEX-1 mutation, a transposon insertion in the dPHEX-1 promoter region, was completely lethal at an early stage of embryonic development. The present study indicates that three homologues are likely involved in the phosphate homeostasis of Drosophila.     

Regucalcin increases superoxide dismutase activity in the heart cytosol of normal and regucalcin transgenic rats

The effect of regucalcin, a regulatory protein in the intracellular signaling system, on superoxide dismutase (SOD) activity in the heart cytosol of normal rats and regucalcin transgenic (TG) rats was investigated. The addition of regucalcin (10(-10) to 10(-8) M) with a physiologic concentration in the enzyme reaction mixture containing the heart cytosol obtained from normal rats caused a significant increase in SOD activity, indicating that regucalcin directly activates the enzyme. The effect of regucalcin (10(-8) M) in increasing SOD activity was not seen in the presence of dithiothreitol (DTT; 0.1 or 1.0 mM), a protecting reagent for sulfhydryl group, or N-ethylmaleimide (NEM; 0.1 or 1.0 mM), a modifying reagent for sulfhydryl group, in the reaction mixture, indicating that regucalcin does not affect the sulfhydryl group. The addition of zinc sulfate (10(-6) to 10(-4) M) in the reaction mixture did not cause a significant change in SOD activity, while the enzyme activity was markedly decreased in the presence of cupric sulfate (10(-6) to 10(-4) M). The activatory effect of regucalcin (10(-8) M) on SOD was seen in the presence of zinc (10(-4) M), while not observed in the presence of copper (10(-4) M). Moreover, SOD activity was significantly enhanced in the heart cytosol of regucalcin TG rats as compared with that of normal rats. This study demonstrates that regucalcin increases SOD activity in the heart cytosol of rats, and that its effect is not related to the sulfhydryl group of enzymes.