Movement of Xanthomonas campestris pv. vitians in the stems of lettuce and seed contamination     

J. D. Barak  S. T. Koike  R. L. Gilbertson † 《Plant pathology》2002,51(4):506-512

Xanthomonas campestris pv. vitians , the causal agent of bacterial leaf spot of lettuce (BLS), can be seedborne, but the mechanism by which the bacteria contaminates and/or infects lettuce seed is not known. In this study, the capacity of X. campestris pv. vitians to enter and translocate within the vascular system of lettuce plants was examined. The stems of 8- to 11-week-old lettuce plants were stab-inoculated, and movement of X. campestris pv. vitians was monitored at various intervals. At 4, 8, 12 and 16 h post-inoculation (hpi), X. campestris pv. vitians was recovered from 2 to 10 cm above (depending on stem length) and 2 cm below the inoculation site. Xanthomonas campestris pv. vitians was also recovered from surface-disinfested stem sections of spray-inoculated plants. Together, these results are consistent with X. campestris pv. vitians invading and moving systemically within the vascular system of lettuce plants. To investigate the mechanism of seed contamination, lettuce plants at the vegetative stage of growth were spray-inoculated with X. campestris pv. vitians and allowed to develop BLS. Seed collected from these plants had a 2% incidence of X. campestris pv. vitians external colonization, but no bacteria were recovered from within the seed.  相似文献   

Mesh-like vascular changes in copper deficiency-induced rat cardiomyopathy     

Rina Yamane  Makoto Tanaka  Nao Kikugawa  Hideki Yasui  Kenta Takei  Miwa Harada  Shinya Kaneda 《Journal of toxicologic pathology》2021,34(1):127

The pathological effects of copper deficiency (COD) are well known. However, the pathogenesis of cardiomyopathy resulting from COD remains unclear. In this study, aimed to elucidate the pathogenesis of COD-induced cardiomyopathy by examining the morphology of the cardiovascular system in copper-deficient rats using histopathology, immunohistochemistry, and scanning and transmission electron microscopy. Changes detected in the myocardium and interstitium were consistent with those reported for COD. Morphological changes included mesh-like changes in the capillary endothelial cells that appear to be a novel finding in COD-induced cardiomyopathy. These changes are hypothesized to result from abnormal vascular remodeling following damage to the basement membrane and due to the mechanical effects of myocardial contractions. Although cardiomyopathy may be associated with microcirculatory disorders arising from these lesions, further investigations are necessary to demonstrate a causal relationship between the pathogenesis of cardiomyopathy and the contribution of these lesions to disease progression.  相似文献   

Quadruple or quintuple conversion of hlb, sak, sea (or sep), scn, and chp genes by bacteriophages in non-beta-hemolysin-producing bovine isolates of Staphylococcus aureus     

Kumagai R  Nakatani K  Ikeya N  Kito Y  Kaidoh T  Takeuchi S 《Veterinary microbiology》2007,122(1-2):190-195

In 13 of 43 non-beta-hemolysin-producing bovine isolates of Staphylococcus aureus, two truncated beta-hemolysin (hlb) genes were demonstrated by PCR and sequencing, and one truncated hlb gene was located beside the integrase (int) gene of phage origin. The staphylokinase (sak) gene was detected in all 13 isolates in which the truncated hlb genes were detected by PCR. Enterotoxin A (sea) and enterotoxin P (sep) genes were also detected in 5 and 2 of the 13 isolates, respectively. Moreover, the scn and chp genes encoding staphylococcal complement inhibitor (SCIN) and chemotaxis inhibitory protein of S. aureus (CHIPS) were detected in 13 and 4 of the 13 isolates, respectively. The bacteriophage induced by mitomycin C treatment was able to lysogenize one beta-hemolysin-producing isolate of S. aureus, and the sak and scn genes were detected from the lysogenized isolate. These results suggest quadruple or quintuple conversion of hlb, sak, sea (or sep), scn, and chp genes by bacteriophages among non-beta-hemolysin-producing bovine isolates of S. aureus.  相似文献   

Abstracts of papers presented at the second otto warburg symposim on biotechnology: plant - microorganism interaction in the rhizosphere     

A. HüTtermann Marie-Therese Oelbe  E. Fritz  G. Schlechte  A. Bytom  A. D. Jungk  Y. Okon  E. Fallik  Rivka Hadas  S. Sarig  E. Yahalom  Sara Tal  A. Hartmann  B. Kishinevsky  Debora Gurfel  Rina Lobel  Y. Kapulnik  D. A. Phillips  Y. Hadar  Y. Chen  E. Jurkevitch  J. Katan  A. Gamliel  H. Ziegler  I. Chet  A. Ordentlich  Hadar Kless  A. Oppenheim  Avia Zilberstein  D. Holland  J. Berman  A. Zamir  R. Kaufman  N. Bawnik  C. Koncz  J. Schell 《Phytoparasitica》1987,15(2):141-147

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Molecular cloning of the feline telomerase reverse transcriptase (TERT) gene and its expression in cell lines and normal tissues     

Yazawa M  Okuda M  Uyama R  Nakagawa T  Kanaya N  Nishimura R  Sasaki N  Masuda K  Ohno K  Tsujimoto H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(5):573-577

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牛奶来源质量监督调查报告   总被引：2，自引：0，他引：2  

王怀蓬  乌日娜 《乳业科学与技术》2008,31(4)

为保证牛奶来源的质量和食品安全,对42个牧场进行随机检查,发现挤奶环境差、现场管理不当、人为搀假问题严重.其中酒精实验不合格和干物质低的牛奶数量最多,酒精阳性奶共48.27 t,干物质低奶54.36 t,分别占总问题奶的37%和44%.希望引起广大奶牛养殖户和乳品企业的重视.  相似文献   

Phosphorus removal in a marine prototype, recirculating aquaculture system   总被引：4，自引：0，他引：4  

Yoram Barak  Eddie Cytryn  Iliya Gelfand  Michael Krom  Jaap van Rijn   《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):313-326

Phosphorus dynamics were examined in a prototype, zero-discharge, marine-recirculating system. Operation of the system without discharge of water and sludge was enabled by recirculation of effluent water through two separate treatment loops. Surface water from the fish basin was pumped over a trickling filter in one loop, while bottom-water was recirculated through a sedimentation basin followed by a fluidized bed reactor in the other treatment loop. Ammonia oxidation to nitrate in the trickling filter and organic matter digestion together with nitrate reduction in the sedimentation basin and fluidized bed reactor were the main biological features of this treatment system. Orthophosphate concentrations did not exceed 15 mg PO₄–P/l in the culture water during more than 1 year of system operation. Much of the phosphorus was retained within the sedimentation basin and fluidized bed reactor. In these treatment stages, the phosphorus content of organic matter was as high as 17.5% and 19%, respectively. High concentrations of total phosphorus and low concentrations of soluble orthophosphate were measured in the initial stages of sedimentation under oxic and anoxic conditions, suggesting that most of the phosphorus was associated with organic matter. Depletion of oxygen and nitrate in the sludge layers of the sedimentation basin coincided with sulfate reduction to sulfide and a release of soluble orthophosphate. The observed phosphorus dynamics in this marine system supported findings from previous studies in which it was demonstrated that denitrifiers underlie phosphorus immobilization under these conditions.  相似文献   

The Cytological Status of Plants Regenerated from Shoot-Meristem Culture of Pisum sativum L     

Rina  Ahmed  S. Dutta  Gupta P. D. Ghosh 《Plant Breeding》1987,98(4):306-311

The cytological status of plantlets regenerated from shoot apical meristems of Pisum sativum was investigated. Chromosome counts in root apices of in vitro regenerated plants showed a preponderance of diploid cells. Moreover, the karyotypes of root-tips from plants derived from culture and from normal plants were basically the same. Topics such as the treatment of chromosomal armlength data, simple statistical comparison of samples derived from normal and regenerated plants are discussed.  相似文献   

Lipid hydroperoxidase activity of myoglobin and phenolic antioxidants in simulated gastric fluid     

Lapidot T  Granit R  Kanner J 《Journal of agricultural and food chemistry》2005,53(9):3391-3396

Our recent study demonstrated the potential of gastric fluid at pH 3.0 to accelerate lipid peroxidation and cooxidation of dietary constituents in the stomach medium. Metmyoglobin is known to catalyze the breakdown of lipid hydroperoxides to free radicals, a reaction that could enhance the propagation step and general lipid peroxidation. During this reaction, a part of the free radicals is autoreduced by metmyoglobin. At pH 3.0, metmyoglobin at low concentration was almost 7 x 10(4) times as effective as at pH 7.0 in enhancing the rate of lipid peroxidation. Our study demonstrated that metmyoglobin, at a low concentration (approximately 1:30), as compared with that of the hydroperoxides in the lipid system, worked prooxidatively increasing the amounts of linoleate hydroperoxides. However, at a high concentration (approximately 1:3), metmyoglobin acted antioxidatively and decomposed hydroperoxides, whose concentrations then remained at zero for a long time. Catechin, a known polyphenol, supports the inversion of metmyoglobin catalysis, from prooxidation to antioxidation. The antioxidative activity of the couple metmyoglobin-catechin was better at pH 3.0 than at pH 7.0, indicating that this reaction is more dependent on metmyoglobin than on catechin. During this reaction, catechin or quercetin not only donates reducing equivalents to prevent lipid peroxidation but also prevents the destruction and polymerization of metmyoglobin. The results of this research highlighted the important and possible reactions of heme proteins and polyphenols as couple antioxidants, working as hydroperoxidases or as pseudo-peroxidases. We hypothesize that the occurrence of these reactions in the stomach could have an important impact on our health and might help to better explain the health benefits of including foods rich in polyphenol antioxidants in the meal, especially when consuming red meat.  相似文献   

Injury Induces a Change in the Functional Characteristics of Cells Recovered from Equine Tendon     

Rina KIHARA  Yoshinori KASASHIMA  Katsuhiko ARAI  Yasunori MIYAMOTO 《Journal of Equine Science》2011,22(3):57-60

Injury initiates a repair process characterized by influx of fibroblasts and the rapid formation of fibrous scar tissue and subsequent tissue contraction. The response to injury and behavior of the different tendon fibroblast populations, however, has been poorly characterized. We hypothesized that the fibroblasts recovered from tendon with acute injury would exhibit different cell properties relating to adhesion, migration and tensegrity. To test this hypothesis we evaluated the ability of fibroblasts recovered from normal and injured equine superficial digital flexor tendons (SDFTs). The injured tendon-derived cells showed greater contraction of the collagen gel but poorer adhesion to pepsin-digested collagen, and migration over extracellular matrix proteins compared to normal SDFT-derived fibroblasts. Thus, the cells present within the tendon after injury display different behavior related to wound healing.  相似文献