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1.
Tuberculosis in wild seals and characterisation of the seal bacillus   总被引:3,自引:0,他引:3  
SUMMARY Tuberculosis was diagnosed in 3 otariid seals found dead on beaches at 3 locations on the south coast of Western Australian between May 1990 and March 1991. This confirms that tuberculosis is present in the 2 native seals (Neophoca cinerea and Arctocephalus forsteri) in Western Australian waters. Mycobacterium sp isolated from the lungs of 2 of the seals were studied to determine the similarity of the strains to each other, to the strains isolated during 1986 from Australian sea lions and New Zealand fur seals kept in captivity at a marine park near Perth, Western Australia, and to a strain isolated in 1988 from a seal trainer who worked with the infected captive seals for 3 years. After restriction endonuclease analysis (REA) with the endonucleases Bst Ell, Bcl I and Pvu II, one of the wild seal strains appeared to have identical DNA fragment patterns to the strains from the captive seals and the seal trainer. The other wild seal isolate had identical REA profiles using Bst EII and Bcl I, but a minor difference was detected using Pvu II. Differences in these isolates were more clearly seen in restriction fragment length polymorphisms after hybridisation with two DNA probes. The secretory protein MPB70, present in M bovis, was not detected in wild seal isolates using sodium dodecyl sulphate polyacrylamide gel electrophoresis and Western blotting techniques. Analysis of protein and DNA fragment profiles indicated that seal tuberculosis isolates form a unique cluster within the M tuberculosis complex.  相似文献   
2.
The aim of this study was to establish the dose-response relationship between fat intake and heparin-released plasma lipoprotein lipase (LPL) activity in horses. Eight mature trotters were fed 4 rations with different fat levels (3.0, 5.0, 7.7, or 10.8% fat in the dry matter) according to a 4 X 4 Latin square design. The experimental rations consisted of hay and different concentrates; the concentrates and hay were given in a 3:1 ratio on an energy basis. Soybean oil was added to the concentrates at the expense of isoenergetic amounts of glucose. Blood samples were taken at the end of each dietary period, which lasted 3 weeks. Fat feeding was found to increase heparin-released plasma LPL activity in a dose-dependent fashion. When the data from this study and previous studies were combined it was calculated that an increase in fat intake by 1 g/kg dry matter is associated with an increase in LPL activity by 0.98 micromol fatty acid released-mL(-1) x h(-1). Fat feeding raised the plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, and phospholipids. Diet did not have a statistically significant effect on plasma triacylglycerol concentrations. The results are discussed in the light of the possible enhancing effect of fat feeding on the oxidative capacity of skeletal muscle.  相似文献   
3.
The hypothesis tested was that the intake of extra fat at the expense of an isoenergetic amount of nonstructural carbohydrates reduces fibre utilisation in horses. In a crossover trial with feeding periods of 42 days each, 6 mature trotting horses (age 4-12 years, bodyweight 340-476 kg) were given either a control or test diet. The test concentrate was formulated to contain 37% of net energy in the form of soybean oil. The control concentrate contained an isoenergetic amount of corn starch plus glucose. The concentrates were fed in combination with the same amount of hay so that the control and test diet contained 25.13 and 86.66 g crude fat/kg dry matter, respectively. Apart from the amounts of fat and nonstructural carbohydrates, the 2 diets were identical. The test diet reduced the apparent total tract digestibilities of crude fibre, neutral and acid detergent fibre by 8.0 (P = 0.007), 6.2 (P = 0.022) and 8.3 (P = 0.0005) percentage units, respectively. It is suggested that a high fat intake by horses may increase the amount of fat entering the large intestine to levels that depress fermentation by cellulolytic bacteria. The observed interaction between fat content of the diet and fibre utilisation may have consequences for practical horse feeding in that calculating the energy content of test diets on the basis of feedstuff tables leads to overestimating the amount of energy provided by the high-fibre ingredients of the diets.  相似文献   
4.
This paper presents a review of our current knowledge of short-term regulation of triacylglycerol metabolism by insulin and glucagon in isolated rat hepatocytes. Insulin is devoted to rapidly improve the lipogenic climate of the hepatocyte. The hormone stimulates glycolysis, the conversion of pyruvate into acetyl-CoA, the synthesis of fatty acids and their esterification. The opposite pathways, hydrolysis of triacylglycerols and fatty acid oxidation, are depressed by insulin. Glucagon does all but deteriorate the lipogenic climate within the liver cell as the hormone inhibits triacylglycerol synthesis and stimulates the breakdown of triacylglycerols.  相似文献   
5.
BACKGROUND: Saponins are a class of secondary plant metabolites consisting of a sugar moiety glycosidically linked to a hydrophobic aglycone (sapogenin) that often possess insecticidal activities. Four saponins were selected: two triterpene saponins, Q. saponaria saponins and aescin, and two steroidal saponins, digitonin and diosgenin. Their effects were investigated on an important pest species and a model piercing‐sucking insect, the pea aphid Acyrthosiphon pisum. The triterpene Q. saponaria saponins bark saponin received special attention because of its high activity. Aphids were challenged by oral and contact exposure to demonstrate aphicidal activities, and in choice experiments to support use as a natural deterrent. RESULTS: When aphids were exposed to supplemented artificial diet for 3 days, a strong aphicidal activity was recorded for three of the four saponins, with an LC50 of 0.55 mg mL?1 for Q. saponaria saponins, 0.62 mg mL?1 for aescin and 0.45 mg mL?1 for digitonin. The LT50 values ranged between 1 and 4 days, depending on the dose. For diosgenin, only low toxicity (14%) was scored for concentrations up to 5 mg mL?1. In choice experiments with treated diet, a deterrence index of 0.97 was scored for Q. saponaria saponins at 1 mg mL?1. In contrast, direct contact showed no repellent effect. Spraying of faba bean plants with Q. saponaria saponins resulted in an LC50 of 8.2 mg mL?1. Finally, histological analysis in aphids fed with Q. saponaria saponins demonstrated strong aberrations of the aphid gut epithelium, and exposure of midgut CF‐203 cell lines to Q. saponaria saponins in vitro confirmed the cytotoxic effect. CONCLUSIONS: The present insect experiments provide strong evidence that saponins, as tested here with triterpene Q. saponaria saponins, can be useful as natural aphicides and deterrents. Furthermore, the insect midgut epithelium is suggested to be a primary target of saponin activity.Copyright © 2011 Society of Chemical Industry  相似文献   
6.
Highly conserved protective epitopes on influenza B viruses   总被引:1,自引:0,他引:1  
Identification of broadly neutralizing antibodies against influenza A viruses has raised hopes for the development of monoclonal antibody-based immunotherapy and "universal" vaccines for influenza. However, a substantial part of the annual flu burden is caused by two cocirculating, antigenically distinct lineages of influenza B viruses. Here, we report human monoclonal antibodies, CR8033, CR8071, and CR9114, that protect mice against lethal challenge from both lineages. Antibodies CR8033 and CR8071 recognize distinct conserved epitopes in the head region of the influenza B hemagglutinin (HA), whereas CR9114 binds a conserved epitope in the HA stem and protects against lethal challenge with influenza A and B viruses. These antibodies may inform on development of monoclonal antibody-based treatments and a universal flu vaccine for all influenza A and B viruses.  相似文献   
7.
BACKGROUND: An efficient delivery system for seed‐protectant chemicals is needed in light of several disadvantages of conventional seed treatment methods. This study evaluates the efficacy of film‐coat application in maintaining the persistence and potency of imidacloprid on Lycopersicon esculentum (L.) Mill. seeds after simultaneous storage under ambient and regulated environment in paper and aluminium packages. RESULTS: High‐performance liquid chromatography (HPLC) revealed 0.135 mg kg?1 of herbage material to be the threshold value beyond which absolute control was obtained, and with film coating the latter was achieved even with half‐dosage seed treatment, irrespective of the storage condition. The technique provided early protection to the crop and also nullified the deleterious effects of ambient storage on the persistence and potency of the pesticide. CONCLUSION: Film coating enabled superior pesticide dosage as well as higher biological efficacy to be achieved. Hence, in addition to being an ecofriendly alternative, the technique would be a more economically viable option for storage of treated seeds. Copyright © 2009 Society of Chemical Industry  相似文献   
8.
9.
The field experiments were conducted for two crop years of 1997?–?98 and 1998?–?99 at the Indian Agricultural Research Institute, New Delhi to study the effect of wheat, legume and legume enriched wheat residue (WR) on soil fertility under the rice-wheat cropping system. A rice-wheat cropping system without incorporation of residue depleted organic C over initial level by 0.061%, kjeldahl-N by 0.012%, available P by 0.7?kg ha???1 and available K by 36?kg ha???1, whereas incorporation of Sesbania green manure (SGM), mungbean residue (MBR), SGM?+?WR and MBR?+?WR increased organic C over the initial level by 0.071, 0.100, 0.163 and 0.133%, respectively, kjeldahl-N by 0.001, 0.004, 0.001 and 0.005% respectively, available P by 2.7, 5.0, 8.5 and 3.2?kg ha???1, respectively and available K by 35, 5, 92 and 12?kg ha???1, respectively in 2 years. As compared with no residue control, incorporation of WR increased organic C by 0.036?–?0.102%, kjeldahl-N by 0.002?–?0.007% and available K by 23?–?45?kg ha?1, whereas incorporation of SGM and MBR increased organic C by 0.082?–?0.132 and 0.103?–?0.161%, respectively, kjeldahl-N by 0.009?–?0.023 and 0.005?–?0.013%, respectively and available K by 5?–?71 and 4?–?45?kg ha???1, respectively. Incorporation of WR with SGM and MBR was more effective and increased organic C by 0.121?–?0.224 and 0.125?–?0.194%, respectively, kjeldahl-N by 0.005?–?0.029 and 0.010?–?0.021%, respectively and available K content by 23?–?128 and 11?–?116?kg ha???1. Nitrogen application to rice also increased organic C, kjeldahl-N, available P and available K content in soil and also increased effects of crop residues. Crop residues had no significant effect on available P content in soil. Incorporation of WR with SGM and MBR with adequate fertilizer-N is, thus, recommended for building up organic C, kjeldahl-N and available K content in soil.  相似文献   
10.
This study evaluates the effects of ascorbic acid and its interaction with follicle-stimulating hormone (FSH) on the morphology, activation, and in vitro growth of caprine preantral follicles. Ovarian fragments were cultured for 1, 7, or 14 d in minimum essential medium (MEM) containing ascorbic acid (50 or 100 μg/mL), FSH (50 ng/mL), or both of these substances. Ovarian tissue that was either fresh (control) or cultured for 1, 7, or 14 d was processed for histological and ultrastructural evaluation. The results showed that after 14 d of culture, medium supplemented with 50 μg/mL of ascorbic acid alone or combined with FSH showed higher rates of follicular survival compared with MEM. After 7 d of culture, FSH, ascorbic acid at 50 μg/mL with or without FSH, and ascorbic acid at 100 μg/mL increased the percentage of follicular activation compared to fresh control. In addition, FSH alone significantly increased the percentage of growing follicles after 14 d. The combination of 50 μg/mL of ascorbic acid and FSH promoted a significant increase in oocyte and follicular diameter after 7 d of culture. Ultrastructural and fluorescent analysis confirmed the integrity of follicles cultured with 50 μg/mL of ascorbic acid and FSH after 14 d. In conclusion, the combination of 50 μg/mL of ascorbic acid and FSH maintained follicular integrity and promoted follicular activation and growth after long-term in vitro culture of caprine preantral follicles.  相似文献   
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