共查询到20条相似文献,搜索用时 31 毫秒
1.
Luciana A. F. Gil Carlos Eduardo P. da Cunha Gustavo M. S. G. Moreira Felipe M. Salvarani Ronnie A. Assis Francisco Carlos F. Lobato Marcelo Mendon?a Odir A. Dellagostin Fabricio R. Concei??o 《PloS one》2013,8(7)
Bovine botulism is a fatal disease that is caused by botulinum neurotoxins (BoNTs) produced by Clostridium botulinum serotypes C and D and that causes great economic losses, with nearly 100% lethality during outbreaks. It has also been considered a potential source of human food-borne illness in many countries. Vaccination has been reported to be the most effective way to control bovine botulism. However, the commercially available toxoid-based vaccines are difficult and hazardous to produce. Neutralizing antibodies targeted against the C-terminal fragment of the BoNT heavy chain (HC) are known to confer efficient protection against lethal doses of BoNTs. In this study, a novel recombinant chimera, consisting of Escherichia coli heat-labile enterotoxin B subunit (LTB), a strong adjuvant of the humoral immune response, fused to the HC of BoNT serotypes C and D, was produced in E. coli. Mice vaccinated with the chimera containing LTB and an equivalent molar ratio of the chimera without LTB plus aluminum hydroxide (Al(OH)3) developed 2 IU/mL of antitoxins for both serotypes. Guinea pigs immunized with the recombinant chimera with LTB plus Al(OH)3 developed a protective immune response against both BoNT/C (5 IU/mL) and BoNT/D (10 IU/mL), as determined by a mouse neutralization bioassay with pooled sera. The results achieved with guinea pig sera fulfilled the requirements of commercial vaccines for prevention of botulism, as determined by the Brazilian Ministry of Agriculture, Livestock and Food, Supply. The presence of LTB was essential for the development of a strong humoral immune response, as it acted in synergism with Al(OH)3. Thus, the vaccine described in this study is a strong candidate for the control of botulism in cattle. 相似文献
2.
《Biological Control》2004,29(1):109-114
The Colorado potato beetle is an important pest on potato, eggplant, and tomato. Because Colorado potato beetles develop resistance to insecticides quickly, new methods are needed for control. Bacillus thuringiensis is the only bacterium to successfully control Colorado potato beetle. Until recently, one of the drawbacks to testing bacteria against the Colorado potato beetle has been the lack of an artificial diet for screening. Previous artificial diets will only be consumed by Colorado potato beetle larvae when fresh. To improve storage, we developed a freeze-dried diet, based on a 96-well plate, suitable to feed larvae for the duration of a bioassay. Individual diet components were tested both for their effect on insect growth and on pathogen toxicity. When the preservatives, methylparaben and sorbic acid, were removed from the diet, the average weight of second instar larvae increased from 7.9 mg to greater than 9.8 mg. The preservatives inhibited the growth of two of the bacteria tested, Photorhabdus luminescens HM and Chromobacterium sp. PRAA. The removal of these preservatives also allowed for fungal growth and reduced survival from 94 to 38%. Removing diet preservatives, that inhibited the growth of Chromobacterium sp. PRAA, increased the total mortality of the larvae as well as reducing the time needed to kill 50% of the larvae. Compared to incorporation of bacteria into molten diet, the total mortality of Colorado potato beetle fed either P. luminescens HM or Chromobacterium sp. PRAA on freeze-dried diet doubled. Preparation of freeze-dried diet need not be synchronized with the insect or the pathogen. The freeze-dried diet gave consistent results as measured by low control mortality and pathogen toxicity over time. 相似文献
3.
J.M. Ritter M-A. Ongari S.E. Barrow M.A. Orchard I.A. Blair P.J. Lewis 《Prostaglandins & other lipid mediators》1982,24(6):881-886
A discrepancy between published values of PGI2 production by human umbilical artery
measured by platelet bioassay, compared with values of 6-oxo-PGF1α by radioimmunoassay, raised the possibility that another anti-aggregatory prostanoid was produced by this tissue. To test this hypothesis, umbilical artery rings were incubated in buffer and PGI2 determined by platelet bioassay and by a more specific radioimmunoassay based on comparison of 6-oxo-PGF1α in hydrolysed and non-hydrolysed samples. 6-oxo-PGF1a, PGF2α and TXB2 were also measured by gas chromatography negative ion chemical ionisation mass spectrometry. PGI2 concentrations by radioimmunoassay and bioassay were significantly correlated (r = 0.92, p < 0.01). There was no difference between them, disproving the presence of an additional antiaggregatory substance. PGI2 production determined by bioassay (mean 1.21 ng/mg wet weight/h, range 0.59–1.53 ng/mg/h) differed from previously reported values (range 70–325 ng/mg/h). 6-oxo-PGF1α concentrations were confirmed by gas chromatography negative ion chemical ionisation mass spectrometry. Previous determinations of PGI2 production by this tissue overestimated it by approximately 100 times. 相似文献
4.
U. Sivagurunathan Prem Prakash Srivastava Subodh Gupta Gopal Krishna 《Saudi Journal of Biological Sciences》2020,27(12):3593-3600
This study assessed the responses of vitamin-D3 intraperitoneally injected to Rohu, Labeo rohita @ of 0 IU/kg bw (only solvent), 100 IU/kg bw and 500 IU/kg bw reared in 20 and 40 ppm of calcium (Ca) enriched water. The cellular changes in Corpuscles of Stannius (CS) gland, serum Ca, and inorganic phosphate (Pi) level were analysed up to the 60th day. Rohu administered with 100 IU/kg bw D3 and exposed to 40 ppm Ca-rich water exhibited notable hyperplasia of CS compared with their control groups. Notable changes with high serum Ca level (13.87 ± 0.3 mg/dl) was detected on the 5th day in fish exposed to 40 ppm Ca-rich water, while related values attained (13.74 ± 0.1 mg/dl) only after 7 days in 20 ppm Ca-rich water of 500 IU/kg bw vitamin D3 injection. Similarly, high serum Pi level (7.66 ± 0.2 mg/dl) in 40 ppm Ca injected with D3 at 500 IU/kg bw. The results demonstrated that the Ca homeostasis of Labeo rohita is influenced by intra-peritoneal vitamin D3. Progressive studies should be conducted by increasing the dose of vitamin D3 to investigate optimum dose/supplement in feed for commercially important aquaculture teleost Labeo rohita for maximum and sustainable absorption of Ca from the variable water Calcium levels to maintain Ca2+ homeostasis. 相似文献
5.
Fatty acid composition of lipids from adult Glossina morsitans was unaffected by an in vitro fed diet of cow blood which induces production of under-sized offspring compared to that of flies fed on a superior diet of pig blood. The commonest fatty acids were C16:0, C16:1 and C18:1 and only small differences in proportions were detected between virgin and pregnant females. Rate of lipid accumulation by males and females was the same and was unaffected by diet, but males achieved a maximum of 2.5 mg on day 9 while both virgin and fertilised females reached a maximum of 5,0 mg on day 14 of adult life. Lipid content of pregnant flies then fell to 3.0 mg on the day of larviposition and accumulation began again. A cow blood diet reduced the extent to which the lipids were utilised for larval growth and this was reflected in an altered secretory activity cycle in the female uterine gland. However, no effect on the growth of adult fat body was detectable in such flies. Mating and fertilisation, which influence reproductive events through activity of the endrocine system do not seem to affect the acquisition of lipid reserves by female Glossina. However, they clearly exert considerable influence over distribution of such reserves between fat body and uterine gland, which distribution is also affected by diet. 相似文献
6.
The stem of Cassia siamea L. (Fabaceae) has been used in traditional Thai medicine as a longevity remedy. The objective of this study was to investigate the effect of ethanolic stem extract of C. siamea (CSE) on the life span of Drosophila melanogaster. The results showed that a diet containing 10 mg/mL CSE could significantly extend the mean life span of D. melanogaster by 14% compared with the control diet (P < 0.01). The maximum life span was 74, 78, and 84 days in control, CSE (5 mg/mL) and CSE (10 mg/mL) groups, respectively. Supplementation of CSE at 10 mg/mL also significantly increases the activity of superoxide dismutase (SOD) and catalase (CAT) at days 25 and 40 compared with the control diet. Treatment of CSE at 5 and 10 mg/mL significantly increased the climbing ability of D. melanogaster both on days 25 and 40 compared with the control flies. Paraquat and H2O2 challenge test showed that flies fed with CSE at 10 mg/mL had a longer survival time than the control flies (P < 0.01). This study provides supportive evidence that supplementation with CSE prolonged life span and reduced oxidative stress in D. melanogaster. 相似文献
7.
Studies on the aflatoxins, toxic metabolites of Aspergillus flavus and A. parasiticus, have involved test systems ranging from cell cultures to laboratory animals. This work reports on the differential response by sex of Oncopeltus fasciatus to aflatoxin B1 (AFB1). Young adult milkweed bugs were chosen randomly from our stock colony and housed in glass culture jars. Triplicate sets of experimental animals were fed 5 μg/ml of AFB1 in their liquid diet. The first death for the experimental females occurred at day 4, and at 10 days for the experimental males. A 50% lethality level for experimental females developed by day 8. Males subjected to the same concentration achieved a 50% lethality level at day 24. For the females the LD50 occurred after consuming 0.49 μg/ml of AFB1. The results indicate that adult female milkweed bugs were hypersensitive to AFB1 as compared to adult males. This organism is more sensitive than the American cockroach and less sensitive than the fruitfly, housefly, and honeybee to toxic aflatoxicosis. Even the female is not sufficiently sensitive to rate highly as a bioassay organism for AFB1. The extreme difference in mortality between the sexes is significant, unusual, and unexplained. 相似文献
8.
Ahmad Arouri Jakub Trojnar Steffen Schmidt Anders H. Hansen Jan Mollenhauer Ole G. Mouritsen 《PloS one》2015,10(5)
The feasibility of exploiting secretory phospholipase A2 (sPLA2) enzymes, which are overexpressed in tumors, to activate drug release from liposomes precisely at the tumor site has been demonstrated before. Although the efficacy of the developed formulations was evaluated using in vitro and in vivo models, the pattern of sPLA2-assisted drug release is unknown due to the lack of a suitable bio-relevant model. We report here on the development of a novel bioluminescence living-cell-based luciferase assay for the monitoring of sPLA2-triggered release of luciferin from liposomes. To this end, we engineered breast cancer cells to produce both luciferase and sPLA2 enzymes, where the latter is secreted to the extracellular medium. We report on setting up a robust and reproducible bioassay for testing sPLA2-sensitive, luciferin remote-loaded liposomal formulations, using 1,2-distearoyl-sn-glycero-3-phosphatidylcholine/1,2-distearoyl-sn-glycero-3-phosphatidylglycerol (DSPC/DSPG) 7:3 and DSPC/DSPG/cholesterol 4:3:3 as initial test systems. Upon their addition to the cells, the liposomes were degraded almost instantaneously by sPLA2 releasing the encapsulated luciferin, which provided readout from the luciferase-expressing cells. Cholesterol enhanced the integrity of the formulation without affecting its susceptibility to sPLA2. PEGylation of the liposomes only moderately broadened the release profile of luciferin. The provided bioassay represents a useful tool for monitoring active drug release in situ in real time as well as for testing and optimizing of sPLA2-sensitive lipid formulations. In addition, the bioassay will pave the way for future in-depth in vitro and in vivo studies. 相似文献
9.
《Animal : an international journal of animal bioscience》2016,10(7):1129-1136
The protective effects of dietary pyrroloquinoline quinone disodium (PQQ.Na2) supplementation against oxidized sunflower oil-induced oxidative stress and liver injury in laying hens were examined. Three hundred and sixty 53-week-old Hy-Line Gray laying hens were randomly allocated into one of the five dietary treatments. The treatments included: (1) a diet containing 2% fresh sunflower oil; (2) a diet containing 2% thermally oxidized sunflower oil; (3) an oxidized sunflower oil diet with 100 mg/kg of added vitamin E; (4) an oxidized sunflower oil diet with 0.08 mg/kg of PQQ.Na2; and (5) an oxidized sunflower oil diet with 0.12 mg/kg of PQQ.Na2. Birds fed the oxidized sunflower oil diet showed a lower feed intake compared to birds fed the fresh oil diet or oxidized oil diet supplemented with vitamin E (P=0.009). Exposure to oxidized sunflower oil increased plasma malondialdehyde (P<0.001), hepatic reactive oxygen species (P<0.05) and carbonyl group levels (P<0.001), but decreased plasma glutathione levels (P=0.006) in laying hens. These unfavorable changes induced by the oxidized sunflower oil diet were modulated by dietary vitamin E or PQQ.Na2 supplementation to levels comparable to the fresh oil group. Dietary supplementation with PQQ.Na2 or vitamin E increased the activities of total superoxide dismutase and glutathione peroxidase in plasma and the liver, when compared with the oxidized sunflower oil group (P<0.05). PQQ.Na2 or vitamin E diminished the oxidized sunflower oil diet induced elevation of liver weight (P=0.026), liver to BW ratio (P=0.001) and plasma activities of alanine aminotransferase (P=0.001) and aspartate aminotransferase (P<0.001) and maintained these indices at the similar levels to the fresh oil diet. Furthermore, oxidized sunflower oil increased hepatic DNA tail length (P<0.05) and tail moment (P<0.05) compared with the fresh oil group. Dietary supplementation of PQQ.Na2 or vitamin E decreased the oxidized oil diet induced DNA tail length and tail moment to the basal levels in fresh oil diet. These results indicate that PQQ.Na2 is a potential antioxidant and is as effective against oxidized oil-related liver injury in laying hens as vitamin E. The protective effects of PQQ.Na2 against liver damage induced by oxidized oil may be partially due to its role in the scavenging of free radicals, inhibiting of lipid peroxidation and enhancing of antioxidant defense systems. 相似文献
10.
Karine Estève C. Poupot P. Dabert M. Mietton-Peuchot V. Milisic 《Journal of industrial microbiology & biotechnology》2009,36(12):1529-1534
This study evaluates the toxic effect of three pesticides (Azoxystrobin, Cymoxanil, and Diuron) on the yeast Saccharomyces cerevisiae for the development of a new bioassay based on inhibition of S. cerevisiae metabolic activity at the level of adenosine-5-triphosphate (ATP) synthesis, as compared with two different toxicity tests based on inhibition of Daphnia magna mobility (NF EN ISO 6341) and inhibition of Vibrio fisheri activity (NF EN ISO 11348). The S. cerevisiae bioassay is cheaper and 96 times faster than the D. magna toxicity bioassay, but has lower sensitivity. It is as fast as the V. fisheri bioassay and more sensitive. Thus, this new toxicity test can be proposed for rapid detection of pesticide residues in environmental samples as a complement to the more expensive and time-consuming D. magna toxicity test. 相似文献
11.
Jeong-Ok Kong Sang-Myung Lee Yil-Seong Moon Sang-Gil Lee Young-Joon Ahn 《Journal of nematology》2007,39(1):31-36
The nematicidal activity of two cassia, Cinnamomum cassia, oils (Especial and true), four cinnamon, Cinnamomum zey-lanicum, oils (technical, #500, bark and green leaf), and their compounds (e.g., trans-cinnamaldehyde and trans-cinnamic acid) toward adult Bursaphelenchus xylophilus was examined by a direct contact bioassay. Results were compared with those of 34 related compounds. As judged by 24-hour LC50 values, two cassia oils (0.084–0.085 mg/ml) and four cinnamon oils (0.064–0.113 mg/ml) were toxic toward adult B. xylophilus. Of 45 test compounds, trans-cinnamaldehyde (0.061 mg/ml) was the most active nematicide, followed by ethyl cinnamate, α-methyl-trans-cinnamaldehyde, methyl cinnamate and allyl cinnamate (0.114–0.195 mg/ml). Potent nematicidal activity was also observed with 4-methoxycinnamonitrile, trans-4-methoxycinnamaldehyde, trans-2-methoxy-cinnamaldehyde, ethyl α-cyanocinnamate, cinnamonitrile and cinnamyl bromide (0.224–0.502 mg/ml). Structure-activity relationships indicate that structural characteristics, such as types of functional groups, saturation and carbon skeleton, appear to play a role in determining the toxicities to adult B. xylophilus. Cassia and cinnamon oils and test compounds described merit further study as potential nematicides or leads for the control of pine wilt disease caused by B. xylophilus. 相似文献
12.
The role of lipid components of the diet in the regulation of the fatty acid composition of the rat liver endoplasmic reticulum and lipid peroxidation 总被引:5,自引:2,他引:3
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The fatty acid compositions of the lipids and the lipid peroxide concentrations and rates of lipid peroxidation were determined in suspensions of liver endoplasmic reticulum isolated from rats fed on synthetic diets in which the fatty acid composition had been varied but the remaining constituents (protein, carbohydrate, vitamins and minerals) kept constant. Stock diet and synthetic diets containing no fat, 10% corn oil, herring oil, coconut oil or lard were used. The fatty acid composition of the liver endoplasmic reticulum lipid was markedly dependent on the fatty acid composition of the dietary lipid. Feeding a herring-oil diet caused incorporation of 8.7% eicosapentaenoic acid (C20:5) and 17% docosahexaenoic acid (C22:6), but only 5.1% linoleic acid (C18:2) and 6.4% arachidonic acid (C20:4), feeding a corn-oil diet caused incorporation of 25.1% C18:2, 17.8% C20:4 and 2.5% C22:6 fatty acids, and feeding a lard diet caused incorporation of 10.3% C18:2, 13.5% C20:4 and 4.3% C22:6 fatty acids into the liver endoplasmic-reticulum lipids. Phenobarbitone injection (100mg/kg) decreased the incorporation of C20:4 and C22:6 fatty acids into the liver endoplasmic reticulum of rats fed on a lard, corn-oil or herring-oil diet. Microsomal lipid peroxide concentrations and rates of peroxidation in the presence of ascorbate depended on the nature and quantity of the polyunsaturated fatty acids in the diet. The lipid peroxide content was 1.82±0.30nmol of malonaldehyde/mg of protein and the rate of peroxidation was 0.60±0.08nmol of malonaldehyde/min per mg of protein after feeding a fat-free diet, and the values were increased to 20.80nmol of malonaldehyde/mg of protein and 3.73nmol of malonaldehyde/min per mg of protein after feeding a 10% herring-oil diet in which polyunsaturated fatty acids formed 24% of the total fatty acids. Addition of α-tocopherol to the diets (120mg/kg of diet) caused a very large decrease in the lipid peroxide concentration and rate of lipid peroxidation in the endoplasmic reticulum, but addition of the synthetic anti-oxidant 2,6-di-t-butyl-4-methylphenol to the diet (100mg/kg of diet) was ineffective. Treatment of the animals with phenobarbitone (1mg/ml of drinking water) caused a sharp fall in the rate of lipid peroxidation. It is concluded that the polyunsaturated fatty acid composition of the diet regulates the fatty acid composition of the liver endoplasmic reticulum, and this in turn is an important factor controlling the rate and extent of lipid peroxidation in vitro and possibly in vivo. 相似文献
13.
Othman Wan-Norafikah Wasi Ahmad Nazni Han Lim Lee Pawanchee Zainol-Ariffin Mohd Sofian-Azirun 《Journal of Asia》2010,13(3):175-182
Permethrin resistance status of a laboratory strain, a permethrin-selected strain and three field strains of Aedes aegypti collected in Kuala Lumpur, Malaysia were evaluated using three standard laboratory bioassays: WHO larval bioassay, WHO adult mosquito bioassay, and mixed function oxidase (MFO) enzyme microassay. The LC50 values of field strains from the WHO larval bioassay did not differ significantly. The highest LC50 value was from the Taman Melati field strain (0.39 mg/L). The resistance ratio for the permethrin-selected strain and the field strains ranged from 1.86 fold to 5.57 fold. Pre-exposure to piperonyl butoxide (PBO) in the WHO adult bioassay and MFOs enzyme microassay reduced the LT50 values and reduced the mean optical density of elevated oxidase activity (0.28–0.42) at 630 nm. The LC50 or LT50 values and the level of oxidases were significantly correlated (r = 0.825; p< 0.05). This study confirmed the presence of permethrin resistance in these mosquito populations. 相似文献
14.
Thomas Cameron Mac Innes 《Journal of invertebrate pathology》2009,101(2):137-139
Some Bacillus thuringiensis strains secrete β-exotoxin, which is an insecticidal, thermostable adenine nucleotide analogue. Discrepancies between detection of β-exotoxin by high-performance liquid chromatography and insect bioassays have shown the importance of bioassays in the determination of β-exotoxin production. With the aim of improving the fly β-exotoxin bioassay, a range of fly diets were evaluated and the best performing diet was incorporated into a novel β-exotoxin bioassay. The improved bioassay is characterised by good control pupation percentages, low variability, easy setup and monitoring. The bioassay allowed unambiguous differentiation between β-exotoxin producing and non-producing strains, and is suitable for the routine screening of B. thuringiensis strains for β-exotoxins. 相似文献
15.
Jian-Feng Zhong 《Journal of insect physiology》2010,56(12):1777-1782
Hydrogen sulfide (H2S) has been shown to effect physiological alterations in several animals, frequently leading to an improvement in survival in otherwise lethal conditions. In the present paper, a volatility bioassay system was developed to evaluate the survivorship of Drosophila melanogaster adults exposed to H2S gas that emanated from a K2S donor. Using this bioassay system, we found that H2S exposure significantly increased the survival of flies under arid and food-free conditions, but not under humid and food-free conditions. This suggests that H2S plays a role in desiccation tolerance but not in nutritional stress alleviation. To further confirm the suggestion, the mRNA levels of two desiccation tolerance-related genes Frost and Desat2, and a starvation-related gene Smp-30, from the control and treated flies were measured by quantitative real-time PCR. These genes were up-regulated within 2 h when the flies transferred to the arid and food-free bioassay system. Addition of H2S further increased Frost and Desat2 mRNA levels, in contrast to Smp-30. Thus, our molecular results were consistent with our bioassay findings. Because of the molecular and genetic tools available for Drosophila, the fly will be a useful system for determining how H2S regulates various physiological alterations. 相似文献
16.
Meridic and oligidic diets suitable for the continuous culture of the aphid Myzus persicae were developed through modifications of a holidic diet. These included the addition of various amounts of crude nutrients and the replacement of defined nutrients by crude nutrients. The highest level of aphid growth (mean weights of 600 to 800 μg) was maintained (for 45 successive generations) on a meridic diet made by supplementing a holidic diet with 2.0% yeast extract (NBC).Continuous culture, at a level of growth (400 to 600 μg) comparable to that on the unsupplemented holidic diet (formulated with 34 defined nutrients), was supported by an oligidic diet containing only 10 weighed ingredients: 15 g sucrose, 2.5 g enzymatic casein hydrolysate (NBC), 2 g yeast extract, 123 mg MgSO4·7H2O, 100 mg ascorbic acid, 10 mg niacin, 5 mg Ca pantothenate, 2.5 mg pyridoxine, 2.5 mg thiamine, and appx. 1.5 gm K2HPO4·3H2O (pH 6.8) per 100 ml of diet.Yeast extract at 2.0% provided adequate amounts of choline chloride, biotin, folic acid and inositol, but not of niacin, pantothenate, pyridoxine, and thiamine. Enzymatic casein hydrolyzate at 2.5% could replace the 20 defined amino acids of the holidic diet. Diets with both yeast extract and casein hydrolysate did not have to be supplemented with trace minerals (Cu, Fe, Mn and Zn). Yeast extract at 2.5% provided sufficient amounts of trace minerals, amino acids, and B-vitamins to sustain numerous successive generations, albeit at a low level of growth (200 to 300 μg). The simplicity and low cost of oligidic diets makes them attractive for aphid studies in which nutrition is not the primary consideration. 相似文献
17.
We investigated the impact of vitamin D deficiency and repletion on muscle anabolism in old rats. Animals were fed a control (1 IU vitamin D3/g, ctrl, n=20) or a vitamin D-depleted diet (VDD; 0 IU, n=30) for 6 months. A subset was thereafter sacrificed in the control (ctrl6) and depleted groups (VDD6). Remaining control animals were kept for 3 additional months on the same diet (ctrl9), while a part of VDD rats continued on a depleted diet (VDD9) and another part was supplemented with vitamin D (5 IU, VDS9). The ctr16 and VDD6 rats and the ctr19, VDD9 and VDS9 rats were 21 and 24 months old, respectively. Vitamin D status, body weight and composition, muscle strength, weight and lipid content were evaluated. Muscle protein synthesis rate (fractional synthesis rate; FSR) and the activation of controlling pathways were measured. VDD reduced plasma 25(OH)-vitamin D, reaching deficiency (<25 nM), while 25(OH)-vitamin D increased to 118 nM in the VDS group (P<.0001). VDD animals gained weight (P<.05) with no corresponding changes in lean mass or muscle strength. Weight gain was associated with an increase in fat mass (+63%, P<.05), intramyocellular lipids (+75%, P<.05) and a trend toward a decreased plantaris weight (−19%, P=.12). Muscle FSR decreased by 40% in the VDD group (P<.001), but was restored by vitamin D supplementation (+70%, P<.0001). Such changes were linked to an over-phosphorylation of eIF2α. In conclusion, vitamin D deficiency in old rats increases adiposity and leads to reduced muscle protein synthesis through activation of eIF2α. These disorders are restored by vitamin D supplementation. 相似文献
18.
Jin-Ling Yang Ping Zhu Gui-Fang Cheng Ke-Di Cheng Hui-Xia He Hui-Xin Zhu 《World journal of microbiology & biotechnology》2009,25(11):2053-2056
BmK AngM1 is an analgesic peptide from the venom of Buthus martensii Karsch (BmK). The synthetic gene encoding BmK AngM1 was optimized on the basis of its cDNA sequence and the codon usage preference of Pichia pastoris. The codon-optimized gene was cloned into pPIC9K and then transformed into P. pastoris. SDS-PAGE and Western blot analysis showed that the recombinant BmK AngM1 (rBmK AngM1) was expressed by the addition of methanol to the medium, and its maximum production reached above 500 mg/l. The purified rBmK AngM1 could be obtained efficiently by Nickel affinity chromatography. Analgesic bioassay, by the mouse-twisting model, showed that rBmK AngM1 had evident analgesic effect with an ED50 of 0.5 mg/kg. 相似文献
19.
Parekkat Ramachandran Ragesh Tenzin Nyibum Bhutia Satish Ganta Ashok Kumar Singh 《Archives Of Phytopathology And Plant Protection》2016,49(1-4):19-30
Repellent, antifeedant and toxic effect of crude hexane extract of Ageratum conyzoides were investigated against Helicoverpa armigera. In orientation bioassay, the extract exhibited dose-dependent repellency against neonates. Extract significantly increased the mortality and decreased growth of different larval stages when administrated orally in artificial diet. EC50 value was at 0.11% for larval growth inhibition. Toxicity of the extract was manifested by high mortality of first instar larvae after 7 days of feeding on diet containing 0.05–0.4% of extract with LC50 of 0.17%. Under choice bioassay, extract showed strong antifeedant activity against fifth instar larvae with DI50 of 0.21%. In nutritional bioassay, extract significantly reduced RCR, RGR, ECI and ECD of fifth instar larvae with increased AD. When RGR were plotted against RCR, the growth efficiency of larvae fed on treated diet was significantly lower than the control fed larvae suggesting the antifeedant and toxic effect of extract. 相似文献
20.
van Frankenhuyzen K Régnière J Bernier-Cardou M 《Journal of invertebrate pathology》2008,99(3):263-274
We examined mortality and feeding inhibition response of Lymantria dispar L. (Lepidoptera: Lymantriidae) larvae to ingested doses of Bacillus thuringiensis subsp. kurstaki as a function of dose, instar and temperature. We developed generalized (logistic) linear mixed models and a mixture survival model, commonly used in medical statistics, to analyze the complex data set. We conducted bioassays of Foray 48B with larvae from the NJSS laboratory stock, using droplet imbibing or force-feeding to ensure dose ingestion. The dose causing mortality in 50% of the test population (LD50) under standard test conditions (22 °C) ranged from 0.019 International Units (IU)/larva for first instar larvae (L1) to 1.6 IU/larva for L4. Temperature affected larval mortality in two ways. Mortality occurred sooner and progressed more rapidly with increasing temperature (13-25 °C) at each dose level and instar, while the maximum level of mortality attained by each instar decreased with increasing rearing temperature. The mechanisms underlying this effect are being investigated. Larvae that survived exposure to B. thuringiensis resumed feeding after a period that was dependent on instar, dose, and temperature. The equations describing observed mortality and feeding recovery responses were used to construct a simulation model, which was able to predict both processes, and which forms the basis for a process-oriented model that can be used as a decision support tool in aerial sprays. 相似文献