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1.
Rautenschlein S Sheikh AM Patnayak DP Miller RL Sharma JM Goyal SM 《Avian diseases》2002,46(3):555-561
Since 1997, avian pneumovirus (APV) has caused estimated annual losses of $15 million to the Minnesota turkey industry. In order to develop an attenuated live vaccine against APV, we serially passaged a Minnesota isolate of APV (APV/MN/turkey/1-a/97) in vitro in cell cultures for 41 passages. Laboratory experiments with this high-passage virus (P41) indicated that the attenuated virus provided immunogenic protection to turkeys against challenge with virulent APV, although some birds showed mild to moderate dinical signs after inoculation. To reduce the residual pathogenicity of P41, while maintaining its immunogenicity, we decided to vaccinate turkeys with P41 in the presence of an immunomodulator, S-28828 (1-n-butyl-2-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine-hydrochloride), which is a potent cytokine inducer. The combined inoculation of S-28828 (5 mg/kg body weight) and P41 resulted in a significant reduction in the incidence of virus-induced clinical signs in comparison with birds that received P41 without immunomodulator (P < 0.05). Only 17% of birds inoculated with S-28828 + APV P41 showed mild respiratory symptoms at 5 days postinoculation as compared with 46% of the vaccinated turkeys that did not receive S-28828. Vaccination with either P41 or with P41 + S-28828 protected turkeys against dinical signs and viral replication after challenge with virulent APV. These results indicate that immunomodulators, such as S-28828, may act as good vaccine adjuvants that can reduce the pathogenicity but maintain the immunogenicity of partially attenuated vaccines. 相似文献
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Vegetable grafting for disease management was first used successfully when watermelon grafted onto a Cucurbita moschata rootstock overcame Fusarium wilt. Interspecific grafting has since been used effectively to mitigate several soilborne pathogens in a variety of solanaceous and cucurbitaceous cropping systems. Verticillium wilt caused by Verticillium dahliae is a significant disease in watermelon crops and is difficult to manage. Current management practices, including crop rotation, soil fumigation, and host resistance, are insufficient due to the ability of microsclerotia to persist in absence of a host, lack of efficacy of soil fumigants, and limited availability of resistant cultivars. Watermelon grafted onto commercial cucurbit rootstocks have increased tolerance to Verticillium wilt, although no cucurbit rootstocks are known to be completely resistant. Verticillium wilt incidence decreased on grafted plants grown in artificially and naturally infested soils, while scion health and growth as well as rootstock root mass and vigour increased. Commonly used rootstocks are Lagenaria siceraria, C. moschata, and C. maxima × C. moschata; of these, only C. maxima × C. moschata ‘Tetsukabuto’ reduced severity of Verticillium wilt across several scion cultivars, locations, years, and soil densities of V. dahliae. Although studies on Verticillium wilt resistance of grafted watermelon are few, their combined results suggest the threshold of V. dahliae soil density for watermelon may be around 5–12 cfu/g. This review summarizes available information on Verticillium wilt of watermelon and effects of different rootstock × scion combinations, assisting growers and breeding programmes in decisions to adopt watermelon grafting for management of Verticillium wilt. 相似文献
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Delfosse P Reddy AS Legréve A Devi KT Abdurahman MD Maraite H Reddy DV 《Phytopathology》2000,90(5):537-545
A purification procedure was developed to separate Polymyxa graminisresting spores from sorghum root materials. The spores were used as im-munogen to produce a polyclonal antiserum. In a direct antigen coating enzyme-linked immunosorbent assay (DAC ELISA), the antiserum could detect one sporosorus per well of the ELISA plate. In spiked root samples, the procedure detected one sporosorus per mg of dried sorghum roots. The majority of isolates of P. graminis from Europe, North America, and India reacted strongly with the antiserum. Interestingly, P. graminis isolates from the state of Rajasthan (northern India), from Pakistan, and an isolate from Senegal (West Africa) reacted weakly with the antiserum. The cross-reactivity of the serum with P. betae isolates from Belgium and Turkey was about 40% of that observed for the homologous isolate. There was no reaction with common fungi infecting roots or with the obligate parasite Olpidium brassicae. However, two isolates of Spongospora sub-terranea gave an absorbance similar to that observed with the homologous antigen. The DAC ELISA procedure was successfully used to detect various stages in the life cycle of P. graminis and to detect infection that occurred under natural and controlled environments. A simple procedure to conjugate antibodies to fluorescein 5-isothiocyanate (FITC) is described. Resting spores could be detected in root sections by using FITC-labeled antibodies. The potential for application of the two serological techniques for studying the epidemiology of peanut clump disease and for the characterization of Polymyxa isolates from various geographical origins is discussed. 相似文献
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Embelin, a benzoquinone-derivative isolated from Embelia ribes, when tested for its antibacterial potential exhibited significant inhibition against five and moderate activity against three strains of the 12 bacteria tested. 相似文献
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Extracts from the stem bark of Streblus asper possess insecticidal activity against the fifth instar of Dysdercus cingulatus. Methanolic extract showed an LC(50) value of 5.56 microg/insect. Partition with chloroform increased the insecticidal activity (LC(50) 2.01 microg/insect). Three polyphenolic rich fractions were obtained from silica-gel column chromatography of the chloroform fraction and found to have noteworthy insecticidal activity (LC(50): 1.82 microg, 2.70 microg, 2.26 microg/insect) by topical application. This may provide a useful beginning for the development of biopesticides. 相似文献
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Wood polymer nanocomposites (WPNCs) based on simul wood (Bombex ceiba, L.) were prepared by impregnation of styrene acrylonitrile copolymer, γ-methacryloyloxy trimethyl silane-modified TiO2, SiO2 nanoparticles and nanoclay intercalating mixture through vacuum impregnation. The impact of nanofillers on the physical properties, flame retardancy, water resistance, anti-swelling efficiency and biodegradability of the resultant WPNCs was investigated. Remarkable enhancement in wood properties such as flame retardancy, water resistance and anti-swelling efficiency was achieved with the treatment. The results showed that all the properties were maximum for wood samples treated with SAN/TiO2 (0.5 %)/SiO2 (0.5 %)/nanoclay (0.5 %). The presence of TiO2 nanoparticles in WPNC exhibited antibacterial activity. The resistance to biodegradation was observed by incorporation of nanofillers into wood. 相似文献
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Prattipati Subhashini Devi Botcha Satyanarayana Atluru Arundhati Tamanam Raghava Rao 《Journal of Crop Science and Biotechnology》2014,17(1):21-25
The present study is an attempt to prepare synthetic seeds using alginate encapsulation of nodal explants of Sterculia urens. Regeneration potential of encapsulated nodal segments was tested on MS basal, MS + BA (3.0 mg L?1), MS + TDZ (0.2 mg L?1), and MS + BA (0.5 mg L?1) + NAA (2.0 mg L?1). The regeneration potential was maximum (73.33 ± 1.33) on MS + TDZ (0.2 mg L?1) followed by (69.33 ± 1.76) on MS + BA (3 mg L?1) even after 6 months of storage at 4°C, whereas controls did not show any regeneration potential after 1 week. These findings suggest synthetic seed technology as an alternative method for micropropagation and germplasm conservation of Sterculia urens an endangered species. 相似文献
10.
Myung-Hoo Kim Ji-Young Yang Santi Devi Upadhaya Hyun-Jun Lee Cheol-Heui Yun Jong K. Ha 《Journal of veterinary science (Suw?n-si, Korea)》2011,12(2):151-157
The purpose of our study was to investigate changes in immunological parameters induced by weaning stress (including milk restriction) in calves. Fifteen Holstein calves were subjected to weaning at 6 weeks of age. Blood samples were collected at -14, -7, -2, 1, 3, and 5 days post-weaning (DPW; 0 DPW = 42 days). Weaning caused significant (p < 0.01) increases in the neutrophil (NE):lymphocyte (LY) ratio at 5 DPW with a significant (p < 0.05) reduction of LYs. The concentration of acute-phase proteins (haptoglobin and serum amyloid A) also increased significantly (p < 0.05) at 3 and 5 DPW compared to -2 DPW. Levels of the iron-binding protein lactoferrin decreased significantly (p < 0.05) after weaning. Serum tumor necrosis factor-α and cortisol levels were elevated (p < 0.05) at 3 DPW, while those of serum interferon-γ decreased (p < 0.05) at 1 and 3 DPW compared to levels observed before weaning. Weaning significantly (p < 0.05) decreased the percentage of CD25+ T cells in the peripheral blood. In conclusion, weaning stress affected the NE:LY ratio along with the levels of acute phase proteins, lactoferrin, cortisol, and inflammatory cytokines in the peripheral blood of calves. Weaning stress may induce an acute phase response possibly through the elevation of cortisol production and modulation of inflammatory cytokines. 相似文献