The influence of barley malt protein modification on beer foam stability and their relationship to the barley dimeric alpha-amylase inhibitor-I (BDAI-I) as a possible foam-promoting protein

The foam stability of beer is one of the important key factors in evaluating the quality of beer. The purpose of this study was to investigate the relationship between the level of malt modification (degradation of protein, starch, and so on) and the beer foam stability. This was achieved by examining foam-promoting proteins using two-dimensional gel electrophoresis (2DE). We found that the foam stability of beer samples brewed from the barley malts of cultivars B and C decreased as the level of malt modification increased; however, the foam stability of cultivar A did not change. To identify the property providing the increased foam stability of cultivar A, we analyzed beer proteins using 2DE. We analyzed three fractions that could contain beer foam-promoting proteins, namely, beer whole proteins, salt-precipitated proteins, and the proteins concentrated from beer foam. As a result, we found that in cultivar A, some protein spots did not change in any of these three protein fractions even when the level of malt modification increased, although the corresponding protein spots in cultivars B and C decreased. We analyzed these protein spots by peptide mass finger printing using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. As a result, all of these spots were identified as barley dimeric alpha-amylase inhibitor-I (BDAI-I). These results suggest that BDAI-I is an important contributor to beer foam stability.     

Effects of glutathione treatments during sperm washing and in vitro fertilization on the in vitro early development of embryos of Japanese Black cattle

This study was conducted to examine the effects of adding glutathione (1 mM) to media used for sperm washing and in vitro fertilization (IVF) on the improvement of early development of embryos produced using cryopreserved spermatozoa of the less IVF-competent bull (the one considered unqualified as spermatozoa supplier for the production of bovine blastocysts using IVF). The cryopreserved spermatozoa of this bull were characterized by normal motility and lower ATP content and blastocyst productivity than those of IVF-competent bulls. The addition of glutathione to the sperm washing medium was more effective in improving the productivity of blastocysts and ATP content than the addition of glutathione to the IVF medium or no glutathione addition at all (control). These results suggest that this simple method may be used to improve the potential of cryopreserved spermatozoa of less IVF-competent bulls to fertilize oocytes in vitro and to induce normal embryonic development after fertilization.     

Suppression of lipopolysaccharide and galactosamine-induced hepatic inflammation by red grape pomace

Grape pomace is generated in the production process of wine and grape juices and is an industrial waste. This study investigated whether an intake of grape pomace was able to suppress chronic inflammation induced by lipopolysaccharide (LPS) and galactosamine (GalN) in vivo. When Sprague-Dawley rats were orally given methanolic extracts from red and white grape pomace, the extracts inhibited the LPS/GalN-evoked activation of nuclear factor-κB (NF-κB) dose-dependently, and red grape pomace exerted a stronger effect than white grape one. Next, rats were fed an AIN93 M-based diet containing 5% red grape pomace for 7 days, followed by the intraperitoneal injection of LPS and GalN. The intake of the red grape pomace-supplemented diet was found to suppress the LPS/GalN-induced activation of NF-κB and expression of inducible nitric oxide synthase and cyclooxygenase-2 proteins. These results suggest that red grape pomace may contain an abundance of effective compound(s) for anti-inflammatory action.     

Characterization of ethylene biosynthesis and its regulation during fruit ripening in kiwifruit,Actinidia chinensis ‘Sanuki Gold’

Ethylene biosynthesis in kiwifruit, Actinidia chinensis ‘Sanuki Gold’ was characterized using propylene, an ethylene analog, and 1-methylcyclopropene (1-MCP), an inhibitor of ethylene perception. In fruit harvested between a young stage (66 days after pollination) (DAP) and an early commercial harvesting stage (143 DAP), 2 days of exposure to propylene were sufficient to initiate ethylene biosynthesis while in fruit harvested at commercial harvesting stage (154 DAP), 4 days of propylene treatment were required. This observation suggests that response of ethylene biosynthesis to propylene treatment in kiwifruit declined with fruit maturity. Propylene treatment resulted in up-regulated expression of AC-ACO1, AC-ACO2, AC-SAM1 and AC-SAM2, prior to the induction of AC-ACS1 and ethylene production, confirming that AC-ACS1 is the rate limiting step in ethylene biosynthesis in kiwifruit. Treatment of fruit with more than 5 μL L^?1 of 1-MCP after the induction of ethylene production subsequently suppressed ethylene production and expression of ethylene biosynthesis genes. Treatment of fruit with 1-MCP at harvest followed with propylene treatment delayed the induction of ethylene production and AC-ACS1 expression for 5 days. These observations suggest that in ripening kiwifruit, ethylene biosynthesis is regulated by positive feedback mechanism and that 1-MCP treatment at harvest effectively delays ethylene production by 5 days.     

Relative parasitic fitness of isolates of Pyricularia oryzae Cav. with different sensitivities to fungicides

The relative parasitic fitness of isolates of Pyricularia oryzae with different sensitivities to isoprothiolane (di-isopropyl 1,3-dithiolan-2-ylidenemalonate) and IBP (S-benzyl O, O-di-isopropyl phosphorothioate) was studied in the absence of fungicides. Four field isolates (S-1,S-2,MR-1 and MR-2) and two in-vitro mutants (Rvt-1 and Rvt-2) were used for disease epidemics. S-l and S-2 were wild types; MR-1 and MR-2 were sensitive to isoprothiolane and moderately resistant to IBP, and Rvt-1 and Rvt-2 were resistant to both fungicides. Twelve epidemics were made by inoculating rice seedlings with mixed conidial suspensions of two isolates or mutants. The value of relative parasitic fitness (W = 0-1.0) was calculated for each isolate and epidemic. S-l and S-2 were stronger (W = 1.0) than MR-2, Rvt-1 and Rvt-2; but weaker (W = 0.75, 0.73, respectively) than MR-1. MR-1 was strongest among all isolates and mutants used. MR-2 was slightly weaker (W = 0.9-1.0) than S-l and S-2, but stronger than Rvt-1 and Rvt-2. Rvt-1 and Rvt-2 had smaller values of W, ranging from 0.25-0.58, in the epidemics with each field isolate. These results suggest that the proportions of in-vitro mutants do not increase unless intensive selection pressure is given, and would be expected to decrease rapidly after the selection pressure is removed. Isolates moderately resistant to IBP, such as MR-1 and MR-2, however, had high values of W, suggesting that they would increase or would not decrease rapidly in the absence of selection pressure. These results may well explain why isolates highly resistant to isoprothiolane and IBP have seldom been found, and why a large number of isolates moderately resistant to IBP but sensitive to isoprothiolane have been observed in the field.     

Isolation of Pathogenicity Mutants of Fusarium oxysporum f. sp. melonis by Insertional Mutagenesis

Restriction enzyme-mediated integration (REMI) mutagenesis was used to isolate mutants of Fusarium oxysporum f. sp. melonis impaired in pathogenicity. The race 2 strain Mel02010 was transformed with linearized pSH75, conferring resistance to hygromycin B, with or without the enzyme used to linearize the plasmid. Addition of restriction enzymes did not affect the transformation frequency. A total of 2929 REMI transformants were tested for pathogenicity to three melon cultivars, Amus, Ogon 9 and Ohi. The race 2 strains are pathogenic to Amus and Ogon 9, but not to Ohi. Of 43 transformants with reduced pathogenicity on susceptible melon cultivars, 12 mutants were examined in detail for pathogenicity, vegetative growth and integrative mode of pSH75. The levels of pathogenicity varied among these mutants. Two mutants (B48 and B137) almost completely lost pathogenicity to both susceptible cultivars, and the others had reduced pathogenicity. Mutants B48, B241, B886 and X36 were also impaired in vegetative growth. Mutant B809 was a biotin auxotroph. By DNA gel blot analysis, nine mutants were found to contain a single copy of the transformation vector. These mutants may thus be useful in isolating genes involved in pathogenicity. Received 22 December 2000/ Accepted in revised form 16 April 2001     

Mitotic disruption by a novel pyrimidine herbicide, NS-245852, in oat (Avena sativa L.) roots

The effects of a novel pyrimidine herbicide, NS-245852 [2-chloro-6-fluorophenyl-4-(trifluoromethyl)thieno[2,3-d]pyrimidine-2-yl-ketone], on mitosis in oat ( Avena sativa L. cv. Zenshin) root tips were investigated by using light and immunofluorescence microscopy. The root growth was strongly inhibited at 10⁻⁷ mol L⁻¹ of NS-245852, and swollen root tips were induced at 5 × 10⁻⁸ mol L⁻¹. As observed by the use of light microscopy, the herbicide produced disrupted mitosis and large polynucleate cells in the meristematic root tissue. These symptoms were similar to those of mitotic disrupter herbicides. The immunofluorescence microscopy studies of the root tip cells treated for 30 min revealed that spindle fibers and the preprophase band were reduced, although kinetochore fibers and the phragmoplast were not affected. Kinetochore fibers remained as small fluorescence spots, and the phragmoplast disappeared after a 3 h treatment. No microtubule arrays were observed by a longer treatment (longer than 3 h). Among the microtubule arrays, spindle fibers and the preprophase band were found to be the most sensitive to the herbicide, whereas kinetochore fibers were the most resistant. The phragmoplast was intermediate. Thus, the primary action of NS-245852 is the inhibition of polymerization of tubulin into microtubules.     

Matrix-metalloproteinases-2 and -9 production in bovine endometrial cell culture

In vitro cell culture is a convenient tool for studying cellular mechanisms. In the present study, production of matrix-metalloproteinases (MMPs) in bovine endometrial (containing both epithelial and stromal cells) monolayer cells was examined. Blastocysts attached to the endometrial cells in a monolayer culture were examined for their effects on MMP-2 production. Initial attachment of blastocysts to the monolayer inhibited MMP-2 production by endometrial cells. But once trophoblast cells began to migrate into the endometrial cell layer, MMP-2 production increased, and at the same time MMP-9 production also became evident in the medium. In order to understand how blastocysts affected MMP-2 production, we examined the effect of progesterone, estradiol, insulin-like growth factors (IGFs), tumor necrosis factors (TNFs), and interferon-tau (IFN-tau) supplementation. It was IFN-tau that inhibited the production of MMP-2. In addition, progesterone at a lower dose appeared to inhibit MMP-2 production. Both TNF-alpha and TNF-beta strongly stimulated the production of MMP-2 and MMP-9, whereas IGFs had no effect. Based on these findings, it appears that conceptus has the capacity to inhibit MMP activity.     

Progesterone receptor mRNA levels during pregnancy, labor, lactation and the estrous cycle in rat uterus

Progesterone plays important roles in the regulation of female reproduction. In this study, progesterone receptor (PR) mRNA levels in rat uterus during pregnancy, labor, lactation and the estrous cycle were examined by competitive RT-PCR. During pregnancy and lactation, PR mRNA levels had decreased on day 20 of pregnancy (P20) and P21 compared with P15 but increased during labor. After a decline on day 1 of lactation (L1), PR mRNA levels had increased again on L3 and L14 compared with P15, P18, P20, P21 and P21pm (at 2200-2300 h on P21). There was no significant change in the PR mRNA level during the estrous cycle. The PR mRNA level did not change during 1 week of progesterone treatment or afterwards. Injection of 17beta-estradiol did not affect PR mRNA levels in rats treated with progesterone or those without any injections. In rats on P18, 17beta-estradiol injection did not change PR mRNA levels after sham-operation but induced an increase in PR mRNA levels of rats ovariectomized 6 h before the treatment. These results suggest that uterine PR mRNA levels are differently regulated during late pregnancy, labor and lactation, and during labor estrogen is one of the essential factors for the increase in PR mRNA levels.