Preparation of the addition products of alpha-tocopherol with cholesteryl linoleate-peroxyl radicals

a-Tocopherol was reacted with cholesteryl linoleate hydroperoxides (Ch18:2-OOH) in the presence of an iron-chelate, Fe(III) acetylacetonate, at 37 degrees C in benzene. The reaction products were isolated and identified as four positional isomers of cholesteryl (8a-dioxy-alpha-tocopherone)-epoxyoctadecenoates and two positional isomers of cholesteryl (8a-dioxy-alpha-tocopherone)-octadecadienoates. The result indicates that the peroxyl radicals from Ch18:2-OOH react with the 8a-carbon radical of alpha-tocopherol to form the addition products.     

Bovine immature oocytes acquire developmental competence during meiotic arrest in vitro

To test the hypothesis that oocytes require time to acquire developmental competence during meiotic arrest, we investigated the effects of butyrolactone I (BL I), a potent and specific inhibitor of cyclin-dependent kinase, on the developmental competence of bovine oocytes after in vitro fertilization (IVF) following release from meiotic arrest. In the present study, 4 culture conditions were used: addition of BSA or fetal bovine serum (FBS) under 2 oxygen tensions (5% vs. 20%) during meiotic arrest with 100-microM BL I. The developmental competence to the blastocyst stage was higher (P < 0.01) in oocytes that were arrested in FBS-supplemented medium under 5% O2 (37%) than in oocytes that were arrested under other conditions (5%-24%) or that matured directly following follicle aspiration (23%). The time course of nuclear maturation of BL I-treated oocytes was also examined. The results demonstrated that oocytes treated with BL I start germinal vesicle (GV) breakdown and reach the metaphase II stage 5.5-6.0 h earlier than nonarrested oocytes. The developmental rates to the blastocyst stage of BL I-treated oocytes matured for 15.5 and 21 h were higher (P < 0.05) than those of nontreated oocytes matured for 21 and 26.5 h, respectively. These results demonstrate that bovine immature oocytes, which were arrested at the GV stage with BL I in FBS-supplemented medium under low oxygen tension, acquire higher developmental competence during meiotic arrest.     

Seasonal and perennial changes in the distribution of water in the sapwood of conifers in a sub-frigid zone

An analysis was made of progressive changes in patterns of cavitation in the sapwood of three species of conifer (Larix kaempferi, Abies sachalinensis, and Picea jezoensis) that were growing in a sub-frigid zone. In all three conifers, all tracheids of the newly forming outermost annual ring were filled with water or cytoplasm during the period from May to August. However, many tracheids in the transition zone from earlywood to latewood lost water in September, presumably through drought-induced cavitation. Cavitated tracheids tended to be continuously distributed in a tangential direction. Subsequently, some earlywood tracheids of the outermost annual ring lost water during the period from January to March. This was associated with freeze-thaw cycles. In the second and third annual rings from the cambium of all three conifers, the lumina of most tracheids in the transition zone from earlywood to latewood contained no water. In contrast, some latewood tracheids near the annual ring boundary and many earlywood tracheids retained water in their lumina. The third annual ring had more cavitated tracheids than the second annual ring. Our observations indicated that cavitation progressed gradually in the tracheids of the conifers and that they were never refilled once cavitation had occurred. The region involved in water transport in conifers did not include the entire sapwood and differed among annual rings.     

Effect of polyethylene glycol and dimethyl sulfoxide on the fusion of bovine nuclear transfer using mammary gland epithelial cells

The effects of polyethylene glycol and dimethyl sulfoxide (PEG/DMSO) treatment of donor cells on the fusion and subsequent development of bovine nuclear transfer embryos using mammary gland epithelial (MGE) cells before electrofusion (fresh MGE cells) was studied. The same study was conducted on those cells that were frozen and stored in liquid nitrogen, and then thawed (frozen-thawed MGE cells). Experiment 1 showed that the exposure time and pH of PEG/DMSO solution affected the fusion of nuclear transfer, and that a higher fusion rate was obtained when fresh MGE cells were exposed to PEG/DMSO solution at pH 8.0 for 5 min. In Experiment 2, the proportion of fused oocytes with fresh PEG/DMSO-treated cells (70 +/- 6%) was significantly higher than that with non-treated cells (50 +/- 13%, p < 0.05). The same tendency was observed when frozen-thawed cells as donor nuclei were used (48 +/- 6% vs. 34 +/- 12%, p < 0.05). In addition, PEG/DMSO treatment has neither harmful nor beneficial effects on the cleavage and development of the blastocyst stage of reconstructed embryos (p > 0.05). The fusion and cleavage rates of frozen-thawed cells were significantly lower than those of fresh cells (p < 0.05). After 10 blastocysts, derived from fresh PEG/DMSO-treated cells, were transferred to five recipient heifers, one live female calf was obtained. Experiment 3 showed that PEG/DMSO treatment reduced the viability of both fresh and frozen-thawed MGE cells (p < 0.05). We conclude that the PEG/DMSO treatment of fresh MGE cells, as well as the frozen-thawed cells, before electrofusion has a positive effect on the fusion of nuclear transfer without decreasing the in vitro development of reconstructed embryos.     

Characterization of two isoforms of a human DnaJ homologue,HSJ2

Two cDNA forms were characterized for a human dnaJ homologue, HSJ2. Nucleotide sequencing showed that the gene product HSJ2 was longer than previously reported, extending its homology to other human DnaJ paralogues, and that the two cDNAs encoded two proteins as a result of alternative splicing. The products were 326 amino acids (designated as HSJ2a) and 241 amino acids (HSJ2b) in length, sharing the N-terminal 231 amino acids including the DnaJ homology region. When fused to green fluorescent protein and expressed in HeLa cells, HSJ2a was found to be localized to the nucleus, indicating that HSJ2a is a nuclear co-chaperone. HSJ2b, however, was observed throughout the cell, consistent with the elimination of a putative nuclear localization signal sequence as a result of the alternative splicing.     

Induction of anti-inflammatory responses by dietary Momordica charantia L. (bitter gourd)

We assessed the immunomodulatory activity of Momordica charantia L. (bitter gourd), a vegetable that has been reported to possess various bioactivities. We examined the effect of bitter gourd on intestinal immunity by monitoring the TGF-beta and IL-7 secretion from Caco-2 cells and the IL-10 and IL-12 secretion from THP-1 cells that are used as in vitro models of the intestinal epithelium and monocyte/macrophages, respectively. We also determined the in vivo immunological responses of rats fed on bitter gourd for 3 weeks. We found that bitter gourd induced a decrease in the intestinal secretion of IL-7 and an increase in the secretions of TGF-beta and IL-10, these effects reflecting the bitter gourd-induced changes in systemic immunity, i.e., a decrease in the number of lymphocytes, increases in the populations of Th cells and NK cells, and increase in the Ig production of lymphocytes. Dietary bitter gourd may therefore induce both intestinal and also systemic anti-inflammatory responses.     

Effect of dietary pectin on the production of immunoglobulins and cytokines by mesenteric lymph node lymphocytes in mouse colitis induced with dextran sulfate sodium

The present study explores the dietary effect of pectin on the MLN lymphocyte functions of mice with dextran sulfate sodium (DS)-induced colitis. We found that the immunoglobulin (Ig)A level in mesenteric lymph node (MLN) lymphocytes was high, while the IgE level was lower, in mice fed with pectin than in those fed with cellulose. Interestingly, the fecal IgA concentration of the pectin-fed mice was significantly higher than that of the cellulose-fed mice. The concentrations of interferon-gamma and interleukin (IL)-2 treated with concanavalin A (ConA) were significantly higher in the pectin-fed group than in the cellulose-fed group. Although dietary pectin did not affect the IL-4 and IL-10 levels, the activation-induced IL-4 and IL-10 secretion was lower in MLN cells of the pectin-fed mice than of the cellulose-fed mice following DS-induced colitis. Based on these findings, we propose that the effect of dietary pectin on mice with DS-induced colitis is mediated by the manipulation of Th1 cells. Furthermore, the inhibitory effect of IL-4 and IL-10 by dietary pectin may play an important role in promoting a change in Th1/Th2 balance toward Th1-dominant immunity.     

Effect of the flavonoid components obtained from Scutellaria radix on the histamine,immunoglobulin E and lipid peroxidation of spleen lymphocytes of Sprague-Dawley rats

The effect on the IgE content induced by concanavalin A in spleen lymphocytes of the presence wogonin, ganhuangenin, wogonoside and 3,5,7,2',6'-pentahydroxyl flavanone was investigated. These flavonoid components markedly inhibited the histamine released from cells stimulated with the calcium ionophore, A23187. However, the magnitude of the inhibitory effect on the degree of lipid peroxidation by ConA of these components was in order of PHF>GHG>WG>WGS. Interestingly, WG, GHG and WGS, with a methoxyl group in the A and B rings, strongly inhibited histamine and IgE production, whereas PHF without a methoxyl group was much stronger than that for lipid peroxidation. We suggest that WG, GHG and WGS might block the pathway for the release of histamine, and that the IgE level in spleen lymphocytes is responsible for the lipid peroxidation.