Cerebral vascular hamartoma with thrombosis in a dog     

Sakurai M  Morita T  Kondo H  Uemura T  Haruna A  Shimada A 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(10):1367-1369

A cerebral vascular hamartoma was identified in the frontal lobe, striatum and thalamus of the right side of the brain of a male, 7-year-old Shih Tzu. Histologically, the lesion consisted of thin-walled vessels, which showed various sizes and occasionally contained fibrin thrombi. These vascular walls were composed of a single layer of fibromuscular tissue lined by flat endothelium with various amount of collagen, but devoid of large coat of smooth muscles and elastic tissue. Immunohistochemically, the lining endothelial cells were positive for von Willebrand Factor antibody. Neuropil between the vessels was stained with Klüver-Barrera stain, and positive for synaptophysin and GFAP antibodies. Based on these findings, the lesion was diagnosed as vascular hamartoma, which might resemble venous malformation in humans.  相似文献   

Induction of reactive oxygen generation and functional changes in mitochondria and their involvement in the development of bacterial rot in lettuce caused by Pseudomonas cichorii     

Akinori Kiba  Kyon Ye Lee  Kouhei Ohnishi  Pyoyun Park  Hitoshi Nakayashiki  Yukio Tosa  Shigeyuki Mayama  Yasufumi Hikichi 《Physiological and Molecular Plant Pathology》2009,74(1):45-54

Pseudomonas cichorii is the major causal agent of bacterial rot disease in lettuce, and apoptosis-like programmed cell death is closely associated with disease development. Depletion of cellular ATP and expression of the alternative oxidase gene was observed in lettuce leaves inoculated with P. cichorii suggesting mitochondrial dysfunction. Cytochemical observation showed production of reactive oxygen species in mitochondria of P. cichorii-inoculated lettuce leaf cells. Release of cytochrome c into the cytosol was also induced by inoculation with the bacterium. Superoxide production was observed in the mitochondrial fraction isolated from P. cichorii-infected leaves much more intense than water-treated leaves. Loss of swelling ability was also observed in the mitochondrial fractions following inoculation with P. cichorii. Intriguingly, inhibitors of the mitochondrial respiratory complex III prevented loss of swelling ability, whereas superoxide generation was scarcely affected by inhibitors of mitochondrial permeability transition in the mitochondrial fractions. Inhibitors of the mitochondrial respiratory complex III and mitochondrial permeability transition delayed not only P. cichorii-induced cell death, but also disease development. In contrast, P. cichorii-induced DNA fragmentation was not inhibited in the presence of either type of inhibitor. The findings suggest that mitochondria may play a crucial role in DNA fragmentation-independent cell death pathway(s).  相似文献   

Involvement of HLK effectors in Ralstonia solanacearum disease development in tomato   总被引：2，自引：0，他引：2  

Li Chen  Masatoshi Shirota  Yong Zhang  Akinori Kiba  Yasufumi Hikichi  Kouhei Ohnishi 《Journal of General Plant Pathology》2014,80(1):79-84

A multigene family encoding HLK effectors is well conserved in all Ralstonia solanacearum strains. The HLK family contains three paralogous members. We constructed single, double, and triple deletion mutants of hlk genes in R. solanacearum strain OE1-1 and characterized HLK effectors by comparing the phenotypes of the strains. HLK effectors exhibited some functional redundancy. While the triple deletion mutant was significantly impaired in virulence on tomato and multiplied less efficiently than the wild type in the leaves, the mutant was as virulent as the wild type on eggplant and tobacco.  相似文献   

Photoconductive coaxial nanotubes of molecularly connected electron donor and acceptor layers     

Yamamoto Y  Fukushima T  Suna Y  Ishii N  Saeki A  Seki S  Tagawa S  Taniguchi M  Kawai T  Aida T 《Science (New York, N.Y.)》2006,314(5806):1761-1764

Controlled self-assembly of a trinitrofluorenone-appended gemini-shaped amphiphilic hexabenzocoronene selectively formed nanotubes or microfibers with different photochemical properties. In these nanotubes, which are 16 nanometers in diameter and several micrometers long, a molecular layer of electron-accepting trinitrofluorenone laminates an electron-donating graphitic layer of pi-stacked hexabenzocoronene. The coaxial nanotubular structure allows photochemical generation of spatially separated charge carriers and a quick photoconductive response with a large on/off ratio greater than 10(4). In sharp contrast, the microfibers consist of a charge-transfer complex between the hexabenzocoronene and trinitrofluorenone parts and exhibit almost no photocurrent generation.  相似文献   

Multiplex polymerase chain reaction discriminates which eggplant isolates of Corynespora cassiicola are virulent to sweet pepper     

Yoshifumi Shimomoto  Akinori Kiba  Yasufumi Hikichi 《Journal of General Plant Pathology》2015,81(3):226-231

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Life in the fast lane: Revisiting the fast growth—High survival paradigm during the early life stages of fishes     

Dominique Robert  Jun Shoji  Pascal Sirois  Akinori Takasuka  Ignacio A. Catalán  Arild Folkvord  Stuart A. Ludsin  Myron A. Peck  Su Sponaugle  Patricia M. Ayón  Richard D. Brodeur  Emily Y. Campbell  Evan K. D'Alessandro  John F. Dower  Louis Fortier  Alberto G. García  Klaus B. Huebert  Marc Hufnagl  Shin-ichi Ito  Mikimasa Joh  Francis Juanes  Mitsuo Nyuji  Yoshioki Oozeki  Guido Plaza  Motomitsu Takahashi  Yosuke Tanaka  Naoki Tojo  Shingo Watari  Naotaka Yasue  Pierre Pepin 《Fish and Fisheries》2023,24(5):863-888

Early life survival is critical to successful replenishment of fish populations, and hypotheses developed under the Growth-Survival Paradigm (GSP) have guided investigations of controlling processes. The GSP postulates that recruitment depends on growth and mortality rates during early life stages, as well as their duration, after which the mortality declines substantially. The GSP predicts a shift in the frequency distribution of growth histories with age towards faster growth rates relative to the initial population because slow-growing individuals are subject to high mortality (via starvation and predation). However, mortality data compiled from 387 cases published in 153 studies (1971–2022) showed that the GSP was only supported in 56% of cases. Selection against slow growth occurred in two-thirds of field studies, leaving a non-negligible fraction of cases showing either an absence of or inverse growth-selective survival, suggesting the growth-survival relationship is more complex than currently considered within the GSP framework. Stochastic simulations allowed us to assess the influence of key intrinsic and extrinsic factors on the characteristics of surviving larvae and identify knowledge gaps on the drivers of variability in growth-selective survival. We suggest caution when interpreting patterns of growth selection because changes in variance and autocorrelation of individual growth rates among cohorts can invalidate fundamental GSP assumptions. We argue that breakthroughs in recruitment research require a comprehensive, population-specific characterization of the role of predation and intrinsic factors in driving variability in the distribution and autocorrelation of larval growth rates, and of the life stage corresponding to the endpoint of pre-recruited life.  相似文献   

Quantitative structure–activity studies of octopaminergic ligands against Locusta migratoria and Periplaneta americana     

Akinori Hirashima  Kenji Shinkai  Canping Pan  Eiichi Kuwano  Eiji Taniguchi  Morifusa Eto 《Pest management science》1999,55(2):119-128

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Effects of temperature on the growth of a Japanese willow (Salix gilgiana Seemen)     

Kenji Shinohara  Akinori Nagao  Shiro Okuda  Kaoru Niiyama  Toyonobu Sugawa 《Journal of Forest Research》1998,3(1):55-60

The effects of temperature on the growth characteristics of a Japanese willow (Salix gilgiana Seemen) were studied with respect to dry matter production, wood anatomy and the net photosynthetic rates of leaves. Clonal materials were grown in natural-light rooms (phytotrons) at 30°C/25°C, at 25°C/20°C or at 20°C/15°C (day/night: 12 h/12 h), respectively. The elongation rate of shoots from the beginning of June to the end of July was approximately 22 cm per week under the three different sets of conditions. The shoots reached approximately 3 m in height after 4 months of growth. Total dry matter production and dry weights of stems did not differ very much among the three sets of temperature conditions after 9 months of growth. The dry weight of leaves increased at high temperatures while that of roots decreased. The number of vessels increased significantly at 30°C/25°C and 25°C/20°C, whereas the diameters of vessels and fibers, and the double wall thickness of fibers did not vary markedly under all three temperature regimes. The net photosynthetic rate and the respiration rate in mature leaves were highest at 30°C/25°C, and both activities increased with increases in growth temperature. The increase in the photosynthetic rate was much smaller than that in the respiration rate. Individual plants had been completely adapted to the respective growth temperatures, as judged from the decrease in the photosynthetic rate after the transfer to different temperatures. Part of this work was reported at the 102nd Annual Meeting of the Japanese Forestry Society (Nagoya, Japan, 1991). This work was supported by Grants-in-Aid (Integrated Research Program for Effective Use of Biological Activities to Create New Demand) from the Ministry of Agriculture, forestry and Fisheries of Japan (BRP 97-IV-B-10).  相似文献   

Disentangling density‐dependent effects on egg production and survival from egg to recruitment in fish     

Akinori Takasuka  Michio Yoneda  Yoshioki Oozeki 《Fish and Fisheries》2019,20(5):870-887

Understanding of density‐dependent effects is key to achieving sustainable management of self‐regulating biological resources such as fish stocks. Traditionally, density‐dependent effects on population abundance in fish have been considered to occur from hatching to recruitment, based on the paradigm of proportionality between spawning stock biomass and total egg production. Here, we demonstrate how the existence of intraspecific and interspecific density dependence in egg production changes the current understanding of density‐dependent processes in the life history of fish, by disentangling density‐dependent effects on egg production and survival from egg to recruitment, using sardine (Sardinops melanostictus, Clupeidae) and anchovy (Engraulis japonicus, Engraulidae) as model species. For sardine, strong intraspecific density‐dependent effects occurred in egg production, but no density‐dependent effects occurred or if any they were weak enough to be masked by environmental factors from hatching to recruitment. In contrast, for anchovy, interspecific density‐dependent effects occurred in egg production. In the survival after hatching, anchovy experienced stronger intraspecific density‐dependent effects than currently recognized. This analysis could overturn the current understanding of density‐dependent effects in the life history, highlighting contrasts between the effects on individual quality and population abundance and between the model species. We propose to reconsider the basis of fisheries management and recruitment studies based on the revised understanding of density‐dependent effects in the life history of the respective species.  相似文献   

Predation dynamics of mackerel on larval and juvenile anchovy: is capture success linked to prey condition?     

Dominique Robert  Akinori Takasuka  Sayaka Nakatsuka  Hiroshi Kubota  Yoshioki Oozeki  Hiroshi Nishida  Louis Fortier 《Fisheries Science》2010,76(2):183-188

We tested whether the predation dynamics of chub mackerel Scomber japonicus and spotted mackerel S. australasicus on young anchovy Engraulis japonicus relates to individual growth characteristics of the prey and could account for the growth-selective survival predicted by recruitment hypotheses. Juvenile and adult mackerel were sampled along with their young anchovy prey field in 2004 (juvenile mackerel and larval anchovy) and 2005 (adult mackerel and juvenile anchovy) off the Pacific coast of Honshu, Japan. The recent 5-day mean growth rate of larval and juvenile survivors and prey found in the stomach of mackerel was estimated from the otolith microstructure. No significant difference was found between the recent growth of larval or juvenile survivors and that of preyed individuals. We conclude that despite a relatively small body size, the high activity level and predation skills displayed by mackerel prevent fast-growing larvae and early juveniles from benefitting in terms of the expected survival advantage over slow-growers. Hence, growth-selective predation mortality of larval fish would depend on the feeding ecology of the predator rather than predator size. Selection for fast growth is more likely to occur under predation pressure from invertebrate organisms and small pelagic fish specialized on zooplankton, such as herring and anchovy.  相似文献