Kinetics of the hydroxymethylation of phenol II: values of rate parameters and results of simulation experiments

The reaction course of the sodium hydroxidecatalyzed hydroxymethylation of phenol was analyzed by use of high-performance liquid chromatography (HPLC), and the rate constants for the seven reactions taking place consecutively and competitively were evaluated by means of a computer simulation technique. Calibration was done at the quantification of the six phenolic monomers from the peak areas in the HPLC chromatogram, taking the differences in molar ultraviolet absorption intensities of the six compounds into account. The values of the energies of activation for the seven reactions obtained differed greatly from those reported by Eapen and Yeddanapalli. Simulation experiments carried out by use of the newly obtained rate parameters showed that the amounts of phenol left unreacted and 2,4,6-trihydroxymethylphenol in the final reaction product increased as the reaction temperature was increased and the alkali/phenol molar ratio decreased. These phenomena can be attributed to the differences in the energies of activation for the seven reactions and differences in the acid strengths of the six phenolic monomers.Part of this paper was presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998 and at the 1998 annual meeting of the Forest Products Society, Merida, Mexico, June 1998     

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.     

Spontaneous Cardiac Hypertrophy in a Crl:CD(SD) Rat

Cardiac hypertrophy was observed in a 9-week-old Crl:CD(SD) rat that died unexpectedly. The animal was allocated to the control group of a toxicity study, and no abnormalities in its general conditions, body weight or food intake were observed. Necropsy revealed an increase in heart weight. Gross examination indicated cardiac enlargement with thickening of the right and left ventricular walls. Histopathological examination revealed hypertrophy of the cardiomyocytes in the right and left ventricular walls and the interventricular septum. Electron microscopic examination indicated bizarre nuclei and accumulation of an increased number of various sizes of mitochondria in the perinuclear region of the hypertrophied myocytes. Hypertrophied myocytes connected by intensely folded intercalated disks were also observed. Based on these findings, the animal was diagnosed with cardiac hypertrophy. This is the first case report of cardiac hypertrophy in this strain.     

Genesis and characteristics of a red-yellow soil derived from Gabbro,Northern Kyushu

There are few pedological investigations of the soils derived from basic rocks in Japan. The object of this paper is to offer fundamental information concerning the genesis and analytical characteristics of a Red-Yellow soil derived from a basic rock (gabbro) of which silica content is approximately 44 per cent.     

Accuracy comparison of cabbage coverage estimated from remotely sensed imagery using an unmixing method

In this study, accuracy comparisons of the cabbage coverage estimated from AVNIR-2 and QuickBird imagery using an unmixing method were carried out to increase the amount of remote sensing data obtained at different levels of spatial resolution on different observation days. The accuracy rates of the cabbage coverage estimated using an unmixing method from AVNIR-2 and QuickBird imagery were almost the same. This result is very interesting, because it shows that we may be able to evaluate cabbage coverage using remote sensing data obtained at different spatial resolutions on different observation days. Thus, it would be possible to use different remote sensing imagery systems to evaluate cabbage conditions during the growing period using this proposed method.     

Remnants of the early solar system water enriched in heavy oxygen isotopes

Oxygen isotopic composition of our solar system is believed to have resulted from mixing of two isotopically distinct nebular reservoirs, 16O-rich and (17,18)O-rich relative to Earth. The nature and composition of the (17,18)O-rich reservoir are poorly constrained. We report an in situ discovery of a chemically and isotopically unique material distributed ubiquitously in fine-grained matrix of a primitive carbonaceous chondrite Acfer 094. This material formed by oxidation of Fe,Ni-metal and sulfides by water either in the solar nebula or on a planetesimal. Oxygen isotopic composition of this material indicates that the water was highly enriched in 17O and 18O (delta(17,18)O(SMOW) = +180 per thousand per mil), providing the first evidence for an extremely (17,18)O-rich reservoir in the early solar system.     

Isolation of genes showing increased expression during bovine adipocyte differentiation

The adipocyte is important not only for the storage of excess energy as fat, but also for the secretion of homeostatic factors. Gene expression profiles during adipocyte differentiation have been reported previously for mouse 3T3‐L1 cells. However, the profiles of adipogenic gene expression in mice and cattle may be different because several metabolic pathways of the ruminant adipose tissue are different from those of non‐ruminants. The gene expression profile in a clonal bovine intramuscular preadipocyte cell line during adipogenesis was examined using the polymerase chain reaction‐subtraction method. Six hundred and twenty‐one clones, which were expressed at an early stage of differentiation, from the preadipocyte to adipocyte, were isolated and characterized. Further detailed studies were carried out for 86 selected genes using northern blotting. Ten genes were found to be highly expressed after differentiation of bovine intramuscular preadipocyte cells. In particular, the expression profiles of genes for stearoyl CoA desaturase and FK506 binding protein were quite different from the time course of differentiation of that seen in the 3T3‐L1 cells reported previously. In addition, these genes were assigned to bovine chromosomes using a bovine/hamster somatic cell hybrid panel and public database.     

Histochemistry of Silicon in Rice Plant

As seen in the previous paper¹⁾ the use of HF-etching method has added much information to the mode of silicon deposition in rice tissues. The results obtained cover a wide range from root to husk. However, the importance of silicon deposition in epidermis in relation to the resistance of plants to diseases or insect pests makes it desirable to continue further studies of the mode of silicon deposition in outer region of epidermis. The study of microstructure of epidermis in connection with silicon deposition will provide valuable information to the mechanism of resistance rice plant to blast disease, because penetration of the rice leaf by piricularia oryzae is ordinarily through the cuticle rather than via the stomata. It will be of importance also to the study of a possible role of silicon in water economy of rice plant as already suggested by the present authors.     

Quantitative expression and immunohistochemical detection of glucose transporters, GLUT1 and GLUT3 in the rabbit placenta during successful pregnancy

Glucose is essential for the development of the fetus. We address here the quantitative expression and immunohistochemical localization of glucose transporter (GLUT1 and GLUT3) in the rabbit placenta during successful pregnancy. Blood glucose level showed a significant decrease at the gestation period in comparison with non-pregnancy. Maternal serum glucose was gradually increased according to fetal development. Quantitative RT-PCR results showed that expression of GLUT1 was significantly increased from day 13 to day 18, while GLUT3 mRNA level was significantly decreased during the same periods. Western blot analysis demonstrated that GLUT1 protein did not change significantly in the placenta during pregnancy when compared to non-pregnant uteri. Immunohistochemistry indicated that distribution of GLUT1 was observed mainly to the surface of the outer trophoblasts, whereas GLUT3 mainly localized to the basal site of the inner trophoblasts and fetal blood vessels. These results suggest that glucose is transported through GLUT1 from the maternal blood stream for use as a placental fuel and for further transport through GLUT3 to the fetal circulation, thus signifying the distinct anatomical localization of GLUT1 and GLUT3 in the rabbit placenta during successful pregnancy.