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1.
Influence of death struggle on the structural changes in chub mackerel muscle during chilled storage
Masashi Ando Masao Joka Satoshi Mochizuki Koh-Ichi Satoh Yasuyuki Tsukamasa Yasuo Makinodan 《Fisheries Science》2001,67(4):744-751
ABSTRACT: Chub mackerel (34–35 cm, approximately 500 g), which were caught by fishing with a rod and line at the Bungo Channel, Oita prefecture, were rested overnight in a fish preserve and either killed by decapitation (control group) or allowed to struggle in air for 30 min (struggled group). Muscle samples were excised every 4 h, and measurements on breaking strength and histological observations were done for both groups. The breaking strength of muscle in the control group was significantly higher than that in the struggled group, whereby a decrease in breaking strength was delayed for 12 h compared to the struggled group. Light microscopy showed space extension among muscle cells in association with a decrease in breaking strength. Especially in the struggled group, the extended area was larger and the difference in area was significant at the time when breaking strength showed a significant difference. Using electron microscopy, the extended area showed cut and/or disappeared collagen fibrils. From these results, it was demonstrated that struggling to death promoted the degradation of collagen fibrils and the weakening of connective tissue and, resultantly, led to the faster softening of muscle of chub mackerel. 相似文献
2.
3.
Kinetic Parameters of Gross N Mineralization of Peat Soils as Related to the Composition of Soil Organic Matter 总被引:1,自引:0,他引:1
Bentio Heru Purwanto Akira Watanabe Jong Foh Shoon Ken-ichi Kakuda Ho Ando 《Soil Science and Plant Nutrition》2005,51(1):109-115
Peat land has been considered as an alternative type of land for agricultural development especially in the tropics. In the present study, the N-supplying capacity, one of the most important soil properties in terms of crop production, of peat soils was examined. Ten peat soil samples were collected from Indonesia, Malaysia, and Japan. Gross N mineralization in the soil samples was estimated using a zero-order model, and kinetic parameters of mineralization were determined using a simple type model. Soil organic matter composition was investigated using 13 C CPMAS NMR. Mineralization potential ( N 0 ), apparent activation energy ( E a ), and mineralization rate constant ( k ) ranged between 571–2,445 mg kg−1 , 281–8,181 J mol−1 , and 0.009–0.020 d−1 , respectively. Although none of the parameters showed a significant correlation with the soil C/N ratio, a negative correlation was observed between the k value and the ratio of the proportion of alkyl C in total C to that of O -alkyl C estimated by 13 C CPMAS NMR. The latter suggested that the k values were higher in the peat soils relatively rich in readily decomposable organic matter including carbohydrates. 相似文献
4.
Viskam WIJEWARDANA Kikuya SUGIURA Daluthgamage Patsy H. WIJESEKERA Shingo HATOYA Toshiya NISHIMURA Ryoji KANEGI Takahiro USHIGUSA Toshio INABA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(7):771-775
Previously, we reported that ovarian hormones affect the immune response against
E. coli isolated from the dogs affected with pyometra. In order to
investigate mechanisms underlying the immune modulation, we examined the effects of
ovarian hormones on the generation of dendritic cells (DCs), the most potent antigen
presenting cell. DCs were differentiated from peripheral blood monocytes (PBMOs) using a
cytokine cocktail. Both estrogen receptor and progesterone receptors were expressed by the
PBMOs and immature DCs. When various ovarian hormones were added to the culture for the DC
differentiation, progesterone significantly decreased the expression of DC maturation
markers, such as CD1a, CD80 and CD86, on mature DCs. Conversely, the addition of estrogen
to the cultures increased the expression of CD86, but not other maturation makers.
Furthermore, DCs differentiated in the presence of progesterone did not stimulate
allogeneic mononuclear cells in PB. Taken together, these results indicate that
progesterone diminishes the maturation of DCs, leading to decreased immune responses
against invading pathogens. 相似文献
5.
6.
Fipronil modulation of GABAA receptor single-channel currents 总被引:3,自引:0,他引:3
Fipronil is the first phenylpyrazole insecticide introduced for pest control. Although fipronil is known to inhibit GABA receptors, the detailed mechanism of action remains to be seen. In order to elucidate the mechanism of fipronil interaction with the mammalian GABAA system, single-channel patch clamp experiments were performed using rat dorsal root ganglion neurons. The amplitude of main conductance state (27pS) current was not significantly altered by co-application of 10 microM fipronil and 10 microM GABA. The histograms of open time distribution were fitted to a sum of three exponential functions. After application of 10 microM fipronil, the proportion of the fastest component increased slightly and that of the slowest component decreased slightly. Thus, the mean open time was decreased from 11.4 ms to 7.8 ms by fipronil. The histograms of closed time distribution were fitted to a sum of four exponential functions. Fipronil 10 microM prolonged the slowest time constant resulting in a prolongation of the mean closed time from 29.7 ms to 52.8 ms. Thus, the frequency of channel openings was reduced. Thus, the fipronil suppression of GABA-induced whole-cell currents is caused in part by decreases in the channel open time and the frequency of channel openings. 相似文献
7.
Jun Ohnishi Toshio Kitamura Fumihiro Terami Ken-ichiro Honda 《Journal of General Plant Pathology》2011,77(1):54-59
The ability of the whitefly Bemisia tabaci to transmit two strains of Tomato yellow leaf curl virus, the Israel and Mild strains, was studied after serial transfers of individual whiteflies that were viruliferous for both
strains to tomato plants. After single whiteflies had successive acquisition feedings first on a single plant infected with
one strain and then on a plant infected with the other strain, the single whiteflies later transmitted intermittently one,
the other, or both strains to the test plants during serial transfers at 1-day intervals. Because both strains were found
in the head, abdomen, and legs dissected from whiteflies during the retention period after the two successive acquisition
feedings, both strains apparently circulate from midgut cells to salivary glands through the hemolymph. 相似文献
8.
The metabolism of fenitrothion was investigated in highly resistant (Akita-f) and susceptible (SRS) strains of the house fly, Musca domestica L. The Akita-f strain was 3500 times more resistant to fenitrothion than the SRS strain. Fenitrothion, topically applied to the flies, was metabolized in vivo far faster in the Akita-f strain than in the SRS strain. In vitro studies revealed that fenitrothion was metabolized by a cytochrome P-450-dependent monooxygenase system and glutathione S-transferases. The former oxidase system metabolized fenitrothion in vitro into fenitrooxon and 3-methyl-4-nitrophenol as major metabolites, and into 3-hydroxymethyl-fenitrothion and 3-hydroxymethyl-fenitrooxon as minor metabolites. Glutathione S-transferases metabolized fenitrothion into desmethylfenitrothion. The cytochrome P-450-dependent monooxygenase system and glutathione S-transferases of the resistant Akita-f strain had 1.4 to 2.2 times and 9.7 times, respectively, as great activities as those of the susceptible SRS strain. These results suggest the importance of glutathione S-transferases in fenitrothion resistance in the Akita-f strain. 相似文献
9.
Kametani Y Ohshima S Kita YF Shimada S Kamiguchi H Shiina T Inoko H Kulski JK Ando A 《Veterinary immunology and immunopathology》2012,148(3-4):252-259
The expression of the major histocompatibility complex (MHC) classical class I genes is important for the adaptive immune response to target virus-infected cells and cancer cells. The up-regulation of the MHC is achieved by hormonal/cytokine signals including IFN-γ-inducible elements. The swine leukocyte antigen (SLA), the MHC class I region of pigs, consists of the duplicated classical class I genes, SLA-1, SLA-2 and SLA-3, but the molecular mechanisms involved in their up-regulation after T cell stimulation have not been fully elucidated. In order to better understand some of the putative regulatory mechanisms of SLA class I gene expression in activated T cells, we examined the coordinated expression of the SLA classical class I, IFN-γ and interferon regulatory factor-1 (IRF-1) genes in the peripheral blood mononuclear cells (PBMCs) of SLA homozygous Clawn miniature swine stimulated for 72h with either IFN-γ or an enterotoxin produced by Staphylococcus aureus. This enterotoxin, toxic shock syndrome-1 (TSST-1), is known to act as a superantigen (sAG) to activate the T cells in various vertebrate species. We showed by using mAbs and flow cytometry that the CD4(+)CD25(+) cell number of swine PBMCs was also increased by TSST-1 and to a lesser degree by IFN-γ. Time course analyses of the expression of the IFN-γ, IRF-1 and the three classical class I genes, SLA-1, SLA-2, and SLA-3, in PBMCs by quantitative real-time PCR revealed a transitory response to TSST-1 or IFN-γ stimulation. The IFN-γ mRNA levels in the PBMCs were continuously up-regulated over the first 48h by TSST-1 or IFN-γ. In contrast, SLA class I expression moderately increased at 24h and then decreased to a baseline level or less at 72h of IFN-γ or TSST-1 stimulation. The three classical SLA class I genes showed similar expression kinetics, although SLA-3 mRNA level was consistently lower than those of SLA-1 and -2. The expression of IRF-1, a modulator of SLA expression, showed similar kinetics to those of the three classical SLA class I genes. The expression profiles detected by flow cytometry of the SLA molecules on the cell surface of PBMCs were maintained at a consistently high level during cell stimulation with either TSST-1 or IFN-γ, which was distinct from the kinetics of mRNA expression. These results showed that miniature swine SLA class I mRNA expression was effectively and equally up-regulated among the three loci and coordinately with IRF-1 gene expression after stimulation of T cell activation by sAG or IFN-γ. 相似文献
10.
Rebecca Grumet Marivi Colle Kaori Ando Da-Sen Xie Laura Havenga Jessica A. Switzenberg 《European journal of plant pathology / European Foundation for Plant Pathology》2013,135(3):545-560
Plant architectural features can facilitate disease control by creating unfavourable environments for pathogen growth or limiting pathogen contact with the host. In the case of Phytophthora capsici infection of cucumber (Cucumis sativus), the susceptible fruit typically lie in contact with soil under warm, moist conditions of a full canopy, an ideal location for exposure to inoculum and disease development. We have shown that increased row spacing, trellising and architectural variants that allow for more open canopies, such as shorter vines, reduced branching, or smaller leaves, can modify microclimate as assessed by temperature at the location of developing fruits. However, only trellising reduced infection rates (<3 % infection vs. 22 % for control). A cucumber accession PI308916, with extremely short internodes and resulting upright position of young fruit, also exhibited reduced disease. Fruit of PI308916 were susceptible when inoculated with P. capsici, indicating that reduced infection likely resulted from decreased soil contact. The compact trait is inherited as a single recessive gene, cp. Like many architectural traits, cp may be pleiotropic; PI308916-derived breeding lines were reported to have poor seedling emergence. PI308916 exhibited inconsistent apical hook formation that co-segregated with short internodes in F2 and backcross generations, and disorganized internodal cortical cell arrangement. The combined phenotypes suggest either pleiotropy or very tight linkage of genes affecting hormone balance or cell division. The narrow chromosome region recently defined by QTL analysis includes candidate gene homologs of meristem related genes modulating cell division or spacing of lateral shoot organs and genes associated with brassinosteroid signaling or cytokinin content. 相似文献