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31.
Piotr Wieczorek Dorota Miliszkiewicz Barbara Lejczak Miroslaw Soroka Pawel Kafarski 《Pest management science》1994,40(1):57-62
A series of N-(phosphonacetyl)amine derivatives were synthesized and screened for plant-growth regulating activity on Lepidium sativum L. and Cucumis sativus L. Aromatic N-(phosphonoacetyl)amines. which may be considered as possible analogues of N-acylaniline herbicides obtained by replacement of their acyl group by the phosphonacetyl moiety, exhibited significant or moderate herbicidal activity. In contrast, N-(phosphonoacetyl)amino acids and N-(phosphonoacetyl)aminophosphonic acids promoted the growth of L. sativum and C. sativus roots. 相似文献
32.
Correlation of molecular markers and biological properties in Verticillium dahliae and the possible origins of some isolates 总被引:1,自引:0,他引:1
A. Collins J. Mercado-Blanco R. M. Jiménez-Díaz C. Olivares E. Clewes D. J. Barbara † 《Plant pathology》2005,54(4):549-557
Haploid and amphihaploid Verticillium dahliae isolates were studied using PCR-based molecular markers which: (i) discriminate the defoliating and nondefoliating pathotypes (two primer pairs INTD2f/r and INTND2f/r), and (ii) are species-specific (primer pair 19/22). The results were compared with some known biological and other molecular properties of the isolates. Five discrete sequences of the 19/22 amplicon were found. Sequence 4 was associated with both defoliating isolates from Spain and nondefoliating isolates from Spain and USA; these pathotypes were separated by the primer pairs INTD2f/r and INTND2f/r, but the data showed that the primer espdef01 (derived from the 19/22 amplicon) cannot be used for this purpose. Amplicon sizes and sequences with primers 19/22 divided amphihaploid isolates from crucifers (thought to be interspecific hybrids) into those corresponding to the previously reported α and β groups. The β-group isolates had either sequence 4 or 5 (these two differing by a single base). The distinct amplicon sequence 3 given by the α-group isolates demonstrated that the V. dahliae -like 'parent' of this group was molecularly unlike any haploid isolate yet studied. The overall results are discussed in relation to phytosanitary considerations and the probability of defoliating or crucifer pathotypes arising de novo within Europe, either by selection or by interspecific hybridizations. 相似文献
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Dorota Miliszkiewicz Piotr Wieczorek Barbara Lejczak Ewa Kowalik Pawel Kafarski 《Pest management science》1992,34(4):349-354
Phosphonic and phosphinic acid analogues of glutamic and aspartic acids were synthesized and screened for herbicidal activity on Lepidium sativum L. Depending on the chemical structure, they exhibited significant or moderate herbicidal activity against L. sativum roots (with some representatives being equipotent with phosphinothricin), while their influence on shoot growth was negligible. Cucumis sativus L. appeared to be more tolerant to these analogues. The origin of this selectivity remains to be determined. 相似文献
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37.
The basic biology of malignant melanoma: molecular mechanisms of disease progression and comparative aspects 总被引:2,自引:0,他引:2
Sulaimon SS Kitchell BE 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(6):760-772
Malignant melanoma (MM) is a life-threatening disease characterized by a highly aggressive biologic behavior in both humans and dogs. Despite improvements in diagnosis and patient care, most deaths from MM are due to metastases that are resistant to conventional treatment modalities. To ultimately reduce the mortality associated with metastatic disease, it is necessary to better define the fundamental molecular mechanisms of malignant tumor progression. The progression of disease is a consequence of the complex interactions between malignantly transformed cells and host factors. Characterization of the stages of tumor progression and the changes occurring in highly malignant cells is important for the development of effective treatment regimens. The dys-regulated molecular mechanisms of transformed melanocytes are presently being characterized. In this review, we summarize the current understanding of the molecular phases in the progression of MM, which include genetic instability, dysregulated proliferation of melanocytes, increased invasion and metastasis, and angiogenesis. 相似文献
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Oliver SP Almeida RA Gillespie BE Ivey SJ Moorehead H Lunn P Dowlen HH Johnson DL Lamar KC 《Veterinary therapeutics : research in applied veterinary medicine》2003,4(3):299-308
Streptococcus uberis is an important cause of mastitis in dairy cows throughout the world, particularly during the dry period, around the time of calving, and during early lactation. Strategies for controlling S. uberis mastitis have not received adequate research attention and are therefore poorly defined and inadequate. Objectives of the present study were to evaluate the efficacy of extended therapy regimens with pirlimycin for treatment of experimentally induced S. uberis intramammary infections in lactating dairy cows during early lactation and to evaluate the usefulness of the S. uberis experimental infection model for evaluating antimicrobial efficacy in dairy cows. The efficacy of extended pirlimycin intramammary therapy regimens was investigated in 103 mammary glands of 68 dairy cows that became infected following experimental challenge with S. uberis during early lactation. Cows infected with S. uberis in one or both experimentally challenged mammary glands were randomly allocated to three groups, representing three different treatment regimens with pirlimycin, including 2-day (n = 21 cows, 31 mammary quarters), 5-day (n = 21 cows, 32 quarters), and 8-day (n = 26 cows, 40 quarters). For all groups, pirlimycin was administered at a rate of 50 mg of pirlimycin hydrochloride via intramammary infusion. A cure was defined as an experimentally infected mammary gland that was treated with pirlimycin and was bacteriologically negative for the presence of S. uberis at 7, 14, 21, and 28 days after treatment. Experimental S. uberis intramammary infections were eliminated in 58.1% of the infected quarters treated with the pirlimycin 2-day regimen, 68.8% for the 5-day regimen, and 80.0% for the 8-day regimen. Significant differences (P <.05) in efficacy were observed between the 2-day and 8-day treatment regimens. The number of somatic cells in milk decreased significantly following therapy in quarters for which treatment was successful in eliminating S. uberis. However, there was no evidence to suggest that extended therapy with pirlimycin resulted in a greater reduction in somatic cell counts in milk than the 2-day treatment. The S. uberis experimental infection model was a rapid and effective means of evaluating antimicrobial efficacy during early lactation at a time when mammary glands are highly susceptible to S. uberis intramammary infection. 相似文献
40.
The acanthocephalan parasite Pomphorhynchus laevis (Müller, 1776) uses freshwater amphipods as its intermediate host. In order to complete the life cycle, the infected amphipod must be consumed by a fish, where the acanthocephalan will mature and reproduce. Parasite transmission, and therefore fitness, could be enhanced if infected amphipods fail to detect or avoid predatory fish. We compared the activity levels of infected and non-infected amphipods, Echinogammarus stammeri (Karaman, 1931), in both the presence and absence of odours from its natural, definitive host, the fish Leuciscus cephalus (L.). Throughout the experiment, infected amphipods were more active than were non-infected individuals. The non-infected amphipods reduced their activity after the addition of fish odours, but the infected amphipods failed to show a significant decrease. The failure of infected amphipods to reduce activity levels in the presence of fish odour may reflect a parasite strategy to increase its chances of transmission by making its amphipod host more vulnerable to predation by fish. 相似文献