Effects of a macrolide antibiotic on enamel formation in rat incisors--primary lesion of ameloblast at the transition stage     

Abe T  Miyajima H  Okada K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(9):985-988

A novel macrolide antibiotic was administered orally to 5-week-old Jcl:Wistar rats at a dose of 5,000 mg/kg/day for 5 weeks, and then a half of animals were maintained without any treatment for 10 weeks. A white discolored lesion with horizontal stripes developed on the surface of the upper and lower incisors after dosing for 4 weeks, and these macroscopical incisal lesions disappeared with the eruption in 4 weeks after stop of administration. Histopathologically, increase in number of karyopycnosis of ameloblast at the transitional stage, vacuolar degeneration of ameloblast and cystic change in the maturation stage, and impaired iron pigment secretion at the pigmentation stage were observed. Microradiography, calcio-traumatic zones, which means hypocalcification, were observed on the superficial layer of enamel. These results suggest that the primary lesion induced by a novel macrolide antibiotic is the increased karyopycnosis of ameloblast at the transitional stage, and followed by later stage.  相似文献   

Down regulation of a novel protein,PSP, in rat hepatoma cdRLh 84-beared tumor     

Kaneki K  Kanouchi H  Matsumoto M  Kawasaki Y  Akuzawa M  Oka T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(7):781-785

Perchloric acid-soluble protein (PSP) is a members of a new hypothetical family (YER057c/YJGF family) of small proteins with presently unknown function. The high degree of evolutionary conservation of these proteins reflect an involvement in basic cellular regulation. The expression of PSP was examined in rat hepatoma cell dRLh 84-beared rats. The tumor weight increased to 4.24 g at 3 weeks after the transplantation of hepatoma cells and hepatoma which has less differentiated characteristics were observed in rat liver. The expression of PSP in rat hepatoma was down regulated as compared with intact tissue. Thus the expression of PSP seems to be associated with the differentiation process in these transformed cells. On the other hand, some positive cells against the PSP-antibody were observed in the central region of tumor tissue by immunohistochemistry. These cells were shown to be the lymphocytes and the macrophages. The involvement of PSP to cellular growth and differentiation is discussed.  相似文献   

New potyvirus isolated from <Emphasis Type="Italic">Cryptotaenia japonica</Emphasis>     

Kentaro Okuno  Tomoko Hama  Minoru Takeshita  Naruto Furuya  Yoichi Takanami 《Journal of General Plant Pathology》2003,69(2):138-142

 A potyvirus, for which the name Japanese hornwort mosaic virus (JHMV) is proposed, was isolated from Japanese hornwort plants (Cryptotaenia japonica) with mosaic disease symptoms. The virus was used to inoculate mechanically 34 plants belonging to 33 species of 10 families. Of these species seven from two families were infected. Faint chlorotic spots appeared on the inoculated leaves of Chenopodium quinoa and C. amaranticolor, but no systemic infection occurred in these plants. JHMV systemically infected only Umbelliferae plants; they did not infect 26 other species in eight families. JHMV was transmitted in a nonpersistent manner by aphids (Myzus persicae). The virus was a flexuous rod-shaped particle about 750 nm in length. Sequencing the nucleotides in the 3′ terminal region of JHMV revealed that the coat protein contains 280 amino acids with a molecular mass of 32.2 kDa. The nucleotide sequence of the coat protein of JHMV had the highest similarity with that of Zantedeschia mosaic virus (83.3%) compared to those of other potyviruses (57.0%–64.9%). An antiserum against JHMV reacted strongly with JHMV and weakly with Potato virus Y. These results indicate that JHMV is a new potyvirus. Received: September 9, 2002 / Accepted: November 7, 2002 RID="*" ID="*" The nucleotide sequence determined in this work appears in the DDBJ/EMBL/GenBank nucleotide sequence databases with the accession number AB081518  相似文献   

Genetic and biological comparison of tick-borne encephalitis viruses from Hokkaido and far-eastern Russia     

Goto A  Hayasaka D  Yoshii K  Mizutani T  Kariwa H  Takashima I 《The Japanese journal of veterinary research》2002,49(4):297-307

We compared the biological properties of Oshima 5-10 (tick-borne encephalitis [TBE] virus isolated in Hokkaido, Japan) and Sofjin-HO (Far-Eastern subtype TBE virus) including plaque formation, virus replication and virus protein synthesis in BHK-21 cell cultures to reveal strain differences. We also determined the complete nucleotide sequences of both strains and compared the deduced amino acid sequences. Plaques of Oshima 5-10 were smaller than those of Sofjin-HO. Virus titers in culture fluid of Oshima 5-10 were 1/100 of those of Sofjin-HO at 9 and 12 hr after infection. Less viral protein and RNA syntheses of strain Oshima 5-10 was observed than with Sofjin-HO. Genetic analysis revealed 1.4% of amino acids to differ with Sofjin-HO. No difference between the two strains was detected in the motif sequence of the viral enzyme, cleavage sites of viral protein or glycosylation sites of NS1.  相似文献   

Note: Pyrethroid resistance and possible involvement of glutathione<Emphasis Type="Italic">S</Emphasis>-transferases in<Emphasis Type="Italic">Helicoverpa armigera</Emphasis> from Turkey     

Sakine Ugurlu  Metin Konus  Belgin Isgor  Mesude Iscan 《Phytoparasitica》2007,35(1):23-26

An introductory study was conducted to investigate the pyrethroid resistance ofHelicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) strains in Turkey, collected from cotton fields in the Adana and Antalya provinces, through two different synthetic pyrethroid insecticides: lambda-cyhalothrin and esfenvalerate. In addition, the roles of glutathioneS-transferases (GSTs) in this resistance mechanism were analyzed. It was found that whereas resistance ratios for lambda-cyhalothrin (LD₅₀ levels) were 3- and 98-fold increased in the Adana and Antalya strains, respectively, esfenvalerate ratios were 3.3- and 92.3-fold increased in the Adana and Antalya strains, respectively, with respect to the susceptible strain. Furthermore, Adana and Antalya strains showed 2.4- and 2.9-fold higher GST activities than the susceptible strain, respectively. In the Antalya field strain, the minor increase in GST activity compared with the resistance levels implies that GSTs may be not greatly involved in this resistance. It also provides evidence that they could not be the only metabolic mechanism responsible for resistance to lambda-cyhalothrin and esfenvalerate inH. armigera from Turkey. http://www.phytoparasitica.org posting Nov. 16, 2006.  相似文献   

Dhan Pal Singh and Arti Singh,Disease and Insect Resistance in Plants     

Christine Struck 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(1):91-92

  相似文献   

Critical Use Exemption for methyl bromide for soil disinfestation: Italy’s experience with the European union process     

M. Lodovica Gullino  Riccardo Savigliano  Giuliana Gasparrini  Corrado Clini 《Phytoparasitica》2007,35(4):321-329

Methyl bromide (MB) was phased out on January 1, 2005, and a Critical Use Exemption (CUE) process has been established in order to define the rules for allocating the needed amounts of the fumigant. This paper deals with the effects of the CUE process on Italian horticulture. The actual usage of the amounts of MB allocated to Italy for the year 2005 in the different areas and on the economically most important crops was monitored and critically evaluated. The usage pattern monitored shows that already in the first year after MB phaseout, Italy was able to replace it completely on crops such as zucchini, salad greens, basil and watermelon. However, on crops such as tomato, pepper, melon, eggplant, strawberry, and cut flowers, further work is required in order fully to replace MB. The emerging problems and research needs are discussed briefly.  相似文献   

Towards identifying pathogenic determinants of the chickpea pathogen <Emphasis Type="Italic">Ascochyta rabiei</Emphasis>     

David White  Weidong Chen 《European journal of plant pathology / European Foundation for Plant Pathology》2007,119(1):3-12

Ascochyta blight is a serious disease of cool-season grain legumes (chickpea, faba bean, lentil and pea) caused by fungal species of the anamorphic genus Ascochyta and related genera. Despite extensive studies on the biology, ecology, epidemiology and management of the disease, little is known about the pathogenic determinants of these pathogens. This research aims at using Ascochyta rabiei as a model for the genus in investigating genetic factors of pathogenicity, with the ultimate goal of elucidating pathogenic mechanisms. Three advances were made: (1) insertional mutants with altered pathogenicity were identified through in vivo screening, and genomic regions adjacent to the insertion sites in selected mutants were determined; (2) a phage library of A. rabiei genomic DNA was constructed, and the library was estimated to provide complete coverage of the A. rabiei genome. This library was used successfully to recover clones with DNA adjacent to insertional mutation sites and to isolate specific genes; (3) DNA probes specific for an acyl-CoA ligase (cps1) and a polyketide synthase gene (pks1) were developed and library clones containing the corresponding genomic regions were identified from the phage library. These advances provide the foundation and necessary tools for experimentation of ectopic complementation assays and targeted mutagenesis to elucidate the genetic mechanisms of pathogenicity of A. rabiei.  相似文献   

Simulating the cumulative effects of multiple forest management strategies on landscape measures of forest sustainability   总被引：1，自引：2，他引：1  

Eric J. Gustafson  David E. Lytle  Randy Swaty  Craig Loehle 《Landscape Ecology》2007,22(1):141-156

While the cumulative effects of the actions of multiple owners have long been recognized as critically relevant to efforts to maintain sustainable forests at the landscape scale, few studies have addressed these effects. We used the HARVEST timber harvest simulator to predict the cumulative effects of four owner groups (two paper companies, a state forest and non-industrial private owners) with different management objectives on landscape pattern in an upper Michigan landscape managed primarily for timber production. We quantified trends in landscape pattern metrics that were linked to Montreal Process indicators of forest sustainability, and used a simple wildlife habitat model to project habitat trends. Our results showed that most trends were considered favorable for forest sustainability, but that some were not. The proportion of all age classes and some forest types moved closer to presettlement conditions. The trend for the size of uneven-aged patches was essentially flat while the average size of patches of the oldest and youngest age classes increased and the size of patches of the remaining age classes decreased. Forest fragmentation generally declined, but edge density of age classes increased. Late seral forest habitat increased while early successional habitat declined. The owners use different management systems that cumulatively produce a diversity of habitats. Our approach provides a tool to evaluate such cumulative effects on other landscapes owned by multiple owners. The approach holds promise for helping landowner groups develop and evaluate cooperative strategies to improve landscape patterns for forest sustainability.  相似文献   

Identification of functional corridors with movement characteristics of brown bears on the Kenai Peninsula,Alaska   总被引：2，自引：1，他引：2  

Tabitha A. Graves  Sean Farley  Michael I. Goldstein  Christopher Servheen 《Landscape Ecology》2007,22(5):765-772

We identified primary habitat and functional corridors across a landscape using Global Positioning System (GPS) collar locations of brown bears (Ursus arctos). After deriving density, speed, and angular deviation of movement, we classified landscape function for a group of animals with a cluster analysis. We described areas with high amounts of sinuous movement as primary habitat patches and areas with high amounts of very directional, fast movement as highly functional bear corridors. The time between bear locations and scale of analysis influenced the number and size of corridors identified. Bear locations should be collected at intervals ≤6 h to correctly identify travel corridors. Our corridor identification technique will help managers move beyond the theoretical discussion of corridors and linkage zones to active management of landscape features that will preserve connectivity.  相似文献