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161.
Like other plant-pathogenic bacteria, Xanthomonas oryzae pv. oryzae, the causal agent of bacterial leaf blight of rice, has hrp genes that are indispensable for its virulence. The hrp genes are involved in the construction of the type III secretion (T3S) apparatus, through which dozens of virulence-related proteins, called effectors, are directly secreted into plant cells to suppress and disturb plant immune systems and/or induce plant susceptibility genes. The expression of hrp genes is strictly regulated and induced only in plants and in certain nutrient-poor media. Two proteins, HrpG and HrpX, are known as key regulators for hrp gene expression. Great efforts by many researchers have revealed unexpectedly that, besides HrpG and HrpX, many regulators are involved in this regulation, some of which also regulate the expression of virulence-related genes other than hrp. Moreover, it has been found that HrpG and HrpX regulate not only hrp genes and effector genes but also genes unrelated to the T3S system. These findings suggest that the expression of the hrp gene is orchestrally regulated with other virulence-related genes by a complicated, sophisticated regulatory network in X. oryzae pv. oryzae.  相似文献   
162.
The objective of this study was to establish a simple and rapid immunocytochemical technique that can be used in veterinary diagnostic cytology. Air-dried impression smears were collected from canine tumors. Samples of epithelial tumors, mesenchymal tumors, and malignant peripheral nerve sheath tumors and melanomas were used for detection of cytokeratin, vimentin, and S-100 protein, respectively. The labeled streptavidin-biotin system was used in the present study. Optimal fixation was determined using standard immunocytochemical procedures, and acetone fixation was found to be the most effective. Optimal concentrations of primary and secondary antibodies were determined at a preset 5-min incubation. Omission of H(2)O(2) treatment, shortening the time for blocking and labeled-streptavidin incubation, and simplifying washing did not decrease immunopositive intensities or enhance false-positive reactions. The described rapid protocol requires approximately 45min without the use of any special equipment.  相似文献   
163.
In humans, steroid 5α-reductase is involved in the development of benign prostatic hyperplasia (BPH). We tested the steroid 5α-reductase inhibitory activity of the 70% acetone extract of woody plants. The tannin polymer prepared from the 70% acetone extract showed the highest steroid 5α-reductase inhibitory activity. Furthermore, the steroid 5α-reductase inhibitory activity of tannins was not affected by the addition of superoxide dismutase or catalase. It was concluded that the steroid 5α-reductase inhibitory activity of condensed tannin was caused by binding to the steroid 5α-reductase, rather than from the peroxide/superoxide produced by tannins. The tannins, prepared from tree barks, with potential for steroid 5α-reductase inhibitory activity might be advantageous in therapy for steroid 5α-reductase diseases such as BPH or prostate cancer. Part of this report was presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004  相似文献   
164.
T-type is a common chloroplast DNA type among modern potato varieties (Solanum tuberosum), their progenitor Chilean tuberosum, and a diploid wild species S. tarijense. To recreate Chilean tuberosum, we made 983 pollinations between 10 accessions of T-type chloroplast DNA-holding S. tarijense used as females and 32 Andean tetraploid landraces (Andigena) used as males, from which 14 tetraploid hybrids were obtained. These interspecific hybrids grew vigorously with long stolons, flowered well with high male and female fertilities, and matured 1 month later than modern varieties. Seedlings of selfed and sib-crossed interspecific hybrids were artificially selected for tuber yield under long days. The selected clones were grown in the field, of which two clones produced over 1 kg of edible tubers per plant. These results lend experimental support to the hypothesis that the Chilean tuberosum originated by selection for long-day adaptability from tetraploid hybrids that occurred by fertilization of a 2n egg of S. tarijense and n pollen of Andigena.  相似文献   
165.
Background: GM2 gangliosidosis variant 0 (human Sandhoff disease) is a lysosomal storage disorder caused by deficiencies of acid β‐hexosaminidase (Hex) A and Hex B because of an abnormality of the β‐subunit, a common component in these enzyme molecules, which is coded by the HEXB gene. Objective: To describe the clinical, pathological, biochemical, and magnetic resonance imaging (MRI) findings of Sandhoff‐like disease identified in a family of Toy Poodles. Animals: Three red‐haired Toy Poodles demonstrated clinical signs including motor disorders and tremor starting between 9 and 12 months of age. The animals finally died of neurological deterioration between 18 and 23 months of age. There were some lymphocytes with abnormal cytoplasmic vacuoles detected. Methods: Observational case study. Results: The common MRI finding was diffuse T2‐hyperintensity of the subcortical white matter in the cerebrum. Bilateral T2‐hyperintensity and T1‐hypointensity in the nucleus caudatus, and atrophic findings of the cerebrum and cerebellum, were observed in a dog in the late stage. Histopathologically, swollen neurons with pale to eosinophilic granular materials in the cytoplasm were observed throughout the central nervous system. Biochemically, GM2 ganglioside had accumulated in the brain, and Hex A and Hex B were deficient in the brain and liver. Pedigree analysis demonstrated that the 3 affected dogs were from the same family line. Conclusions and Clinical Importance: The Sandhoff‐like disease observed in this family of Toy Poodles is the 2nd occurrence of the canine form of this disease and the 1st report of its identification in a family of dogs.  相似文献   
166.
N-acetyl-d-glucosamine (GlcNAc) is a monosaccharide that polymerizes linearly through (1,4)-β-linkages. GlcNAc is the monomeric unit of the polymer chitin. GlcNAc is a basic component of hyaluronic acid and keratin sulfate found on the cell surface. The aim of this study was to examine amino acid metabolism after oral GlcNAc administration in dogs. Results showed that plasma levels of ectoine were significantly higher after oral administration of GlcNAc than prior to administration (p < 0.001). To our knowledge, there have been no reports of increased ectoine concentrations in the plasma. The mechanism by which GlcNAc administration leads to increased ectoine plasma concentration remains unclear; future studies are required to clarify this mechanism.  相似文献   
167.
In this study, grazing behavior of mares and cows was compared on woodland pastures, in the context of foraging hierarchy. A horse‐group (12 native Hokkaido horses) and a cattle‐group (5 Hereford cows) were grazed on the woodland pastures of 13.3 ha and 5.8 ha, respectively. They grazed mainly on Sasa nipponica. Grazing behavior at a feeding station (FS) scale was recorded for three focal animals in each group. Mares took one bite per FS at a high percentage of FSs (24.3%) and cows took one, two and three bites per FS at high percentage (20.3%, 19.2% and 15.4%, respectively). Although feeding patch (FP) scale for both animals could be defined as a group of FSs, the length of FP and grazing behavior at FP scale were similar for both animals. The number of steps taken between two adjacent FSs or FPs for mares was larger than that for cows. The results suggested that both horses and cattle had similar foraging hierarchy from bite to FP scale but grazing behavior of horses at the FS scale was different from that of cattle, suggesting that grazing behavior of large herbivores has greater similarity in larger foraging hierarchies.  相似文献   
168.
The abundance index (AI) is a representative indicator used to assess the state of fishery resources. Conventional AI is generally calculated by summing the catch per unit of effort (CPUE) weighted by the size of each fishing area. However, CPUE data has many missing values owing to annual changes in operational fishing areas, and this can lead to a considerable bias in the estimated AI. To obtain an unbiased AI, a multivariate auto-regressive state-space (MARSS) model was used to estimate and interpolate missing values in a spatially arranged, long-term bottom-trawl CPUE dataset for yellow seabream Dentex hypselosomus and largehead hairtail Trichiurus japonicus in the East China Sea. As expected, increasing the number of analyzed fishing grids improved interpolation accuracy, but remarkably increased the time required for the analysis. Reducing the maximum number of expectation–maximization (EM) iterations in the maximum likelihood procedure was an effective way to practically reduce analysis time, while keeping the accuracy of the estimation. Thus, this EM-reduction MARSS model was applied to the entire CPUE datasets of yellow seabream and largehead hairtail to address the annual shifts in their AIs and their seasonal migration.  相似文献   
169.
Understanding the immune dynamics in the respiratory mucosa of calves is necessary for a good management of bovine respiratory disease. Immune dynamics in the respiratory mucosa in humans and experimental animals has been assessed by flow cytometric analysis of bronchoalveolar lavage fluid (BALF); however, few reports have addressed this subject in calves. The aim of this study was to establish a universal method to analyze bronchoalveolar lavage fluid (BALF) by flow cytometry and to obtain basic knowledge of bovine respiratory mucosal immune dynamics. We investigated the immune cell populations in BALF and evaluated the surface antigen expression of alveolar macrophages in calves using flow cytometer. To further analyze the surface antigen variation observed in alveolar macrophages in detail, stimulation assays were performed in vitro. BALF cells were separated into three distinct populations based on their light scatter plot, which were considered to be macrophages, lymphocytes, and neutrophils. In most individuals, most of the BALF immune cells were alveolar macrophages, but an increased proportion of lymphocytes and neutrophils was observed in some individuals. Analysis of each surface antigen expression in alveolar macrophages showed that CD21 and MHC class II expression changed in response to changes in the leukocyte population. Moreover, when alveolar macrophages were stimulated with interferon-γ in vitro, the expression of CD21 was drastically reduced and MHC class II was increased, suggesting that functional changes in alveolar macrophages themselves are involved in the immune dynamics.  相似文献   
170.
We investigated how stream fragmentation affects local fish species persistence and extinction from three Rio Grande systems (Texas, USA) stream reaches with different levels of natural fragmentation. We examined species–volume (SV) relationships of fish assemblages in 42 pools across the watersheds and predicted greater fragmentation would correspond to an increase in the slope of the SV relationship due to decreased within‐reach rescue effects. In addition, we examined relationships among tributary‐specific nested subset patterns, local habitat features and spatial position of the reaches relative to the Rio Grande mainstem to better understand the importance of local and regional processes on fish species richness patterns in the stream reaches. Slopes of the SV curves did not differ among the stream reaches, but the intercepts of the SV curves were significantly different. These results indicated rescue effects among habitats within a stream reach were not apparent; however, rescue effects from the mainstem largely determined the species richness of a given stream reach. The nested subset patterns in all stream reaches were related to several local environmental factors, and large, deep pools provided important aquatic refugia in all three systems. We suggest declines in mainstem and tributary flows will likely continue to impact local and regional fish assemblage attributes. High flow events are important for dispersal and can reset tributary fish communities for the next extinction‐driven, successional cycle.  相似文献   
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