Comparison of scytalone dehydratase activities between scytalone dehydratase inhibitor-sensitive and inhibitor-resistant Magnaporthe oryzae isolates

Journal of Plant Diseases and Protection - Magnaporthe oryzae is the causal agent of blast disease of cereals such as rice. Recently, fungal isolates resistant to the melanin biosynthesis...     

Structure-activity relationships of flavonoids as potential inhibitors of glycogen phosphorylase

Flavonoids are ubiquitous components in vegetables, fruits, tea, and wine. Therefore, they are often consumed in large quantities in our daily diet. Several flavonoids have been shown to have potential as antidiabetic agents. In the present study, we focused on inhibition of glycogen phosphorylase (GP) by flavonoids. 6-Hydroxyluteolin, hypolaetin, and quercetagetin were identified as good inhibitors of dephosphorylated GP (GPb), with IC 50 values of 11.6, 15.7, and 9.7 microM, respectively. Furthermore, a structure-activity relationship study revealed that the presence of the 3' and 4' OH groups in the B-ring and double bonds between C2 and C3 in flavones and flavonols are important factors for enzyme recognition and binding. Quercetagetin inhibited GPb in a noncompetitive manner, with a K i value of 3.5 microM. Multiple inhibition studies by Dixon plots suggested that quercetagetin binds to the allosteric site. In primary cultured rat hepatocytes, quercetagetin and quercetin suppressed glucagon-stimulated glycogenolysis, with IC 50 values of 66.2 and 68.7 microM, respectively. These results suggested that as a group of novel GP inhibitors, flavonoids have potential to contribute to the protection or improvement of control of diabetes type II.     

Races of <Emphasis Type="Italic">Phytophthora infestans</Emphasis> isolated from potato in Hokkaido,Japan

The virulence of 29 isolates of Phytophthora infestans collected in potato fields in Hokkaido, Japan, in 2013 and 2014, was tested for race identification. Thirteen different races were identified, each of which had five to eight virulence factors. All of the isolates caused a virulent reaction against plants with R1 and R7, and most of the isolates caused a virulent reaction against plants with R3, R4, R10, and R11. On the other hand, no isolate was virulent against plants with R9. These results demonstrate that the current Japanese P. infestans population is more complex than the population in the 1990s from the viewpoint of race.     

AKD-2023: A novel miticide. Biological activity and mode of action

AKD-2023, 3-dodecyl-1,4-dihydro-1,4-dioxo-2-naphthyl acetate (proposed common name acequinocyl) is a novel miticide now under commercial development. It has outstanding miticidal activity against economically important spider mites with the new mode of action of inhibition of mitochondrial electron transfer at complex III.     

Haemoproteus columbae infection in a straggler racing pigeon sheltered in Japan

A racing pigeon (Columba livia var. domestica), a straggler from Taiwan, was sheltered in Nara Prefecture, Japan in 2020. This pigeon showed hemolysis and elevated levels of hepatobiliary and muscle enzymes. Gametocytes of Haemoproteus columbae (Apicomplexa: Haemosporida) were observed within the host erythrocytes in thin blood smears. A partial sequence of the mitochondrial cytochrome b gene amplified from blood DNA was identical to the lineage HAECOL1 previously reported from pigeons worldwide. This is the first record of H. columbae infection in a sheltered bird in Japan.     

Long-term Pulmonary Responses to Quadweekly Intermittent Intratracheal Spray Instillations of Magnetite (Fe3O4) Nanoparticles for 52 Weeks in Fischer 344 Rats

Information about potential risks of iron nanomaterials is still limited, while a wide variety of applications are expected. We recently reported acute phase responses of male and female Fischer 344 rats after a single intratracheal spray instillation of Fe₃O₄ nanoparticles (magnetite), clearly showing dose-dependent pulmonary inflammatory changes (Tada et al., J Toxicol Pathol 25, 233–239, 2012). The present study assessed long-term responses of male and female Fischer 344 rats to multiple administrations of magnetite. Ten-week-old male and female Fischer 344 rats (n=20/group) were exposed to a total of 13 quadweekly intermittent intratracheal spray instillations of magnetite during the experimental period of 52 weeks, at doses of 0, 0.2 (low), 1.0 (medium) and 5.0 (high-dose) mg/kg body weight per administration. Absolute and relative lung weights of the high-dose group were significantly higher than those of the control group. Macroscopically, slight enlargement and scattered black patches were recognized in the lungs and the lung-associated lymph nodes of the high-dose group. Histopathologically, infiltration of macrophages phagocytosing magnetite (all dose groups) and of chronic inflammatory cells (medium- and high-dose males and high-dose females), alveolar bronchiolization and granuloma (high-dose group) were observed. In addition, alveolar hyperplasias were observed in some rats of the high-dose group, and cytoplasmic overexpression of β-catenin protein was immunohistochemically found in such lesions. The present results clearly show that instilled magnetite causes chronic inflammatory responses in the lung. These responses occur in a dose-dependent manner without apparent differences among sexes     

Comparison of growth histories of immature Japanese common squid Todarodes pacificus between the autumn and winter spawning cohorts based on statolith and gladius analyses

Growth of the autumn and winter spawning cohorts of the Japanese common squid Todarodes pacificus was examined based on daily growth increments in the statolith and gladius. The samples were taken from three groups of young (??180 days old) squid: the autumn cohort collected in the Tsushima Current and the winter cohort collected in the Pacific near the coast and 1100?km offshore. The growth rate based on statolith analysis was highest in the winter cohort near the coast and similar in the two other groups. The daily growth based on gladius analysis during the month before capture was also highest in the winter cohort near the coast, and fluctuated more in the autumn cohort than in the winter cohort. The results suggest that gladius growth increments will be an important tool in future studies of growth in T. pacificus.     

城市地下水硝酸盐污染及其成因分析

用N同位素分析方法并结合调查区域土地利用类型的分析 ,对杭州市城区 2 1口水井取样分析以确定杭州城市地下水的水质结果显示 :本地区地下水硝酸盐污染严重 ,杭州城市地下水水质属于Ⅲ类水标准 ,不宜饮用。有 4 0 5 %样品的NO3 N含量超过了世界卫生组织的标准 (N10mgL-1)。我们发现不同的土地利用区有不同的NO3 N水平 (N 0 0 4～ 34 4 1mgL-1)。同时我们引进N同位素方法以辨明NO3 N污染源 :居住区地下水δ15NNO3值为 10 4‰～ 2 2 0‰ ,农业区δ15NNO3值的为 17 5‰～ 19 5‰。生活污水是城市浅层地下水的主要NO3 N污染源。在居住区还存在点源污染 ,如化粪池 ;种植蔬菜施用的有机肥则是农业区的NO3 N污染源。     

Locally synchronized synaptic inputs

Synaptic inputs on dendrites are nonlinearly converted to action potential outputs, yet the spatiotemporal patterns of dendritic activation remain to be elucidated at single-synapse resolution. In rodents, we optically imaged synaptic activities from hundreds of dendritic spines in hippocampal and neocortical pyramidal neurons ex vivo and in vivo. Adjacent spines were frequently synchronized in spontaneously active networks, thereby forming dendritic foci that received locally convergent inputs from presynaptic cell assemblies. This precise subcellular geometry manifested itself during N-methyl-D-aspartate receptor-dependent circuit remodeling. Thus, clustered synaptic plasticity is innately programmed to compartmentalize correlated inputs along dendrites and may reify nonlinear synaptic integration.