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1.
用20亿PIB/mL灰茶尺蠖病毒(EgNPV)对成年SD大鼠进行急性经口、经皮毒性试验,对白色家兔进行眼刺激和皮肤刺激试验,对豚鼠进行皮肤致敏试验以及进行小鼠急性致病性试验。结果表明20亿PIB/mL灰茶尺蠖病毒(EgNPV)水剂对SD大鼠的急性经口毒性(其LD50雌雄大鼠均5 000 mg/kg)属于低毒;对SD大鼠的急性经皮毒性(其LD50雌雄大鼠均2 000 mg/kg)属于低毒;对家兔的皮肤无刺激性;对家兔的眼睛也无刺激性:在染毒后24 h内不洗眼情况下,眼刺激积分最高为0;对豚鼠的皮肤致敏率为0,其致敏性分级为Ⅰ级,属弱致敏物;病理组织学检查结果表明,各实验组小鼠内脏组织均未见有病理改变,无急性致病性。 相似文献
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目的研究人参皂苷Rb,及Rb,组合物对大鼠急性心肌梗死的保护作用。方法采用大鼠结扎左冠状动脉前降支制备急性心肌梗死模型,计算急性心肌梗死24h后的心肌梗死面积（MIS）,测定血清肌酸磷酸激酶（CK）、乳酸脱氢酶（LDH）、天门冬氨酸氨基转换酶（AST）、超氧物歧化酶（SOD）及谷胱甘肽过氧化物酶（GSH—Px）活力,丙二醛（MAD）及一氧化氮（NO）含量。结果人参皂苷Rb,及Rb：组合物5、10、20mg／kg均可明显缩小急性心肌梗死大鼠的MIS,降低血清CK、LDH、AST活性及MAD含量,提高血清SOD、GSH—Px活性及NO含量。结论人参皂苷Rb,及Rb：组合物对大鼠急性心肌梗死具有明显保护作用,可能与其增强抗氧化酶活性,减少氧自由基对心肌的损伤等机制有关。 相似文献
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Singh Pushpendra Tripathi Manish Kumar Yasir Mohammad Khare Ruchi Tripathi Manoj Kumar Shrivastava Rahul 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(4):458-466
Plant Foods for Human Nutrition - The severe acute respiratory syndrome is a viral respiratory infection and commonly called as COVID-19, caused by severe acute respiratory syndrome coronavirus-2... 相似文献
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Ebrahimi A Nikookhah F Nikpour S Majiian F Gholami M 《Pakistan journal of biological sciences: PJBS》2008,11(1):148-150
Streptococci are frequently isolated from bovine mastitis in dairy cows with only limited information available on the antimicrobial susceptibility of these organisms. A total of 42 Streptococci isolated from 148 milk samples of normal, sub acute and acute bovine mastitis cases. Overall, 35% of the strains tested were Streptococcus dysgalactiae, Streptococcus agalactiae 26%, Streptococcus uberis 18 and 4% were Enterococcus sp. Differences between the number of isolations in acute and sub acute groups were statistically significant, (p<0.5). The antimicrobial susceptibility for these organisms was determined for the following antimicrobial agents: cephalexine, penicillin, clindamycin, cloxaciline, gentamicin, streptomycin, amoxicillin, tetracycline, kanamycin, oxytetracycline, ampicillin, chloramphenicol and erythromycin. S. agalactiae, S. dysgalactiae, S. uberis and Enterococci demonstrated high level of resistance against streptomycin, penicillin and cloxaciline. Low level of sensitivity to other tested antimicrobials was demonstrated. 相似文献
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利用摄入法和点滴法测定高效氯氟氰菊酯、溴氰菊酯、顺式氯氰菊酯、三唑磷、杀螟丹和杀虫双对海南中蜂工蜂的急性经口和接触毒性。结果表明,高效氯氟氰菊酯、溴氰菊酯、顺式氯氰菊酯、三唑磷、杀螟丹和杀虫双对海南中蜂经口毒性(48 h)的LC50分别为3.845、2.527、1.518、0.363、26.866和38.187 mg/L,6种农药对海南中蜂接触毒性(24 h)的LD50分别为42.485、41.292、7.793、18.467、1 027.577和4 049.884 ng/蜂;6种农药对海南中蜂的经口毒性分别为高毒、高毒、高毒、剧毒、中毒和中毒,接触毒性除杀虫双为中毒外,其余均为高毒。 相似文献
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Study of changes in some pathophysiological stress markers in different age groups of an animal model of acute and chronic heat stress 总被引：2，自引：0，他引：2
Sinha RK 《Iranian Biomedical Journal》2007,11(2):101-111
BACKGROUND: This study demonstrates the changes in six different pathophysiological parameters such as body weight, body temperature, fecal pellet count, blood-brain barrier (BBB) permeability, plasma corticosterone level and emergence of hemorrhagic peptic ulcer spots due to exposure to high environmental heat in three different age groups of freely moving rats. METHODS: Each age group of rats was sub divided into three groups: (i) acute heat stress-subjected to a single exposure for four hours in the Biological Oxygen Demand incubator at 38 degrees C; (ii) chronic heat stress-exposed for 21 days daily for one hour in the incubator at 38 degrees C, and (iii) handling control groups. The data were recorded for the analyses of the changes in different parameters just after the heat exposure from acute stressed rats and on 1st, 3rd, 6th, 9th, 12th, 15th, 18th and 21st day on chronic stressed rats for body temperature, body weight, fecal pellets count. For the analysis of changes in three other parameters, BBB permeability, plasma corticosterone level and peptic ulcer spots following chronic exposure to high environmental heat, data were recorded on 22nd day for the analysis. RESULTS: Analysis of variance (ANOVA-1) of the observations demonstrates a significant increase in body temperature, fecal pellet count, BBB permeability (except in adult group), plasma corticosterone level and emergence of hemorrhagic peptic ulcer spots in all three different age group of rats due to exposure to acute heat stress. However, chronic heat was found responsible for the significant reduction in body weight in weaning and young rats, increase in body temperature, number of fecal pellets excreted (in early days of chronic stress) and number of peptic ulcer spots in all three age groups of rats. At the same time, BBB extravasations were not observed in rats except very mild in weaning group. CONCLUSION: The results of the present study indicate that the acute as well as chronic exposure to hot environment significantly alters the physiology of different organs of the body. 相似文献
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Jo?o C. Fernandes Humberto Spindola Vanessa de Sousa Alice Santos-Silva Manuela E. Pintado Francisco Xavier Malcata Jo?o E. Carvalho 《Marine drugs》2010,8(6):1763-1768
All the reports to date on the anti-inflammatory activity of chitooligosaccharides (COS) are mostly based on in vitro methods. In this work, the anti-inflammatory activity of two COS mixtures is characterized in vivo (using balb/c mice), following the carrageenan-induced paw edema method. This is a widely accepted animal model of acute inflammation to evaluate the anti-inflammatory effect of drugs. Our data suggest that COS possess anti-inflammatory activity, which is dependent on dose and, at higher doses, also on the molecular weight. A single dose of 500 mg/kg b.w. weight may be suitable to treat acute inflammation cases; however, further studies are needed to ascertain the effect upon longer inflammation periods as well as studies upon the bioavailability of these compounds. 相似文献
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配方普洱茶的急性毒性研究 总被引：2，自引：0，他引：2
为了探明配方普洱茶饮用的安全性,以标准普洱茶为对照,采用国家标准规定的测量方法分别测定茶样中的理化成分,并进行急性毒性试验。试验测得标准普洱茶、灵芝普洱茶、洋参普洱茶、橄榄普洱茶、荞芽普洱茶等5个茶样对小白鼠的LD50依次为10.32、10.02、10.02、10.96、10.32 g/kg;在理化指标上:配方普洱茶与标准普洱茶没有明显的差异,且符合普洱茶的国家规定。试验结果表明,配方普洱茶的急性毒性与标准普洱茶同样具有较高的食用安全性,从食品毒理学的标准来看,4个配方普洱茶都属于实际无毒。 相似文献
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Breast cancer resistance protein (BCRP) is a protein belonging to the ATP-binding cassette (ABC) transporter superfamily that has clinical relevance due to its multi-drug resistance properties in cancer. BCRP can be associated with clinical cancer drug resistance, in particular acute myelogenous or acute lymphocytic leukemias. The overexpression of BCRP contributes to the resistance of several chemotherapeutic drugs, such as topotecan, methotrexate, mitoxantrone, doxorubicin and daunorubicin. The Food and Drugs Administration has already recognized that BCRP is clinically one of the most important drug transporters, mainly because it leads to a reduction of clinical efficacy of various anticancer drugs through its ATP-dependent drug efflux pump function as well as its apparent participation in drug resistance. This review article aims to summarize the different research findings on marine natural products with BCRP inhibiting activity. In this sense, the potential modulation of physiological targets of BCRP by natural or synthetic compounds offers a great possibility for the discovery of new drugs and valuable research tools to recognize the function of the complex ABC-transporters. 相似文献
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六堡茶急性和亚急性毒性安全性评价研究 总被引：1，自引：0，他引：1
六堡茶产制历史悠久,是广西特色名优农产品,但其安全性研究不够。为了探明六堡茶饮用的安全性,本实验以广西梧州六堡茶为原料,采用国家标准方法分析六堡茶常规理化成分;并按照食品安全性毒理学评价程序,进行较系统的六堡茶急性毒性和亚急性毒性实验。结果表明:六堡茶理化指标符合广西地方标准,且3个批次有较好的重复性;在小鼠急性毒性试验中,采用bliss法计算得出六堡茶半数致死剂量(LD50)为9.38 g·kg~(-1),95%的可信限为8.43~10.44 g·kg~(-1),大于5 g·kg~(-1)的经口急性毒性标准;采用大鼠30 d喂养实验发现,期间动物的生长发育良好,六堡茶3个剂量组(0.47 g·kg~(-1)·d~(-1)、0.94 g·kg~(-1)·d-1、1.88 g·kg~(-1)·d~(-1)的动物体质量、血常规指标、血生化指标、脏器指数与对照组比较,均无显著性差异(P0.05)。因此从食品毒理学的标准来看,六堡茶属于无毒级食品,符合食品安全性要求。 相似文献
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Naghizadeh B Boroushaki MT Vahdati Mashhadian N Mansouri MT 《Iranian Biomedical Journal》2008,12(2):93-100
Background. The major side effect of cisplatin, used in some tumours, is nephrotoxicity. Reactive oxygen species and oxidative damage are the most important factors in cisplatin-induced acute renal failure. The main purpose of this study is to investigate the protective effects of crocin against cisplatin-induced acute renal failure and oxidative stress in rat. Methods. In this study, animals were randomly divided into 5 groups (6 each). Group one received normal saline (2 ml/day, i.p.). Group two received a single dose of cisplatin (5 mg/kg, i.p.). Groups 3 to 5 received crocin (100, 200 and 400 mg/kg, i.p., respectively, for 4 consecutive days one hour before a single dose of cisplatin (5 mg/kg) only at the first day. Blood samples were taken out (on the fifth day) for measuring the level of urea and creatinine. The kidneys were removed for histopathological and biochemical examinations. Furthermore, 24-hour urinary factors were measured. Results. Blood urea, creatinine and urinary glucose and protein concentrations in crocin-treated groups were significantly lower than those of cisplatin-treated group in a dose-dependent manner. Histopathological studies showed a massive damage in S3 segment of proximal tubules in cisplatin-treated group. No damage was observed in crocin-treated groups. Crocin treatment resulted in a significant and dose-dependent reduction in malondialdehyde concentration as compared to the cisplatin-treated group. Moreover, crocin produced a significant elevation in total thiol and glutathione peroxidase concentrations, as compared with cisplatin-treated group. Conclusion. The results of the present study suggest that crocin has a protective effect against cisplatin-induced acute renal failure and relative oxidative stress. 相似文献
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Compromised lung function is a feature of both infection driven and non-infective pathologies. Viral infections—including the current pandemic strain SARS-CoV-2—that affect lung function can cause both acute and long-term chronic damage. SARS-CoV-2 infection suppresses innate immunity and promotes an inflammatory response. Targeting these aspects of SARS-CoV-2 is important as the pandemic affects greater proportions of the population. In clinical and animal studies, fucoidans have been shown to increase innate immunity and decrease inflammation. In addition, dietary fucoidan has been shown to attenuate pulmonary damage in a model of acute viral infection. Direct inhibition of SARS-CoV-2 in vitro has been described, but is not universal. This short review summarizes the current research on fucoidan with regard to viral lung infections and lung damage. 相似文献
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To investigate the hematologic changes and the activities of jellyfish venoms other than hemolytic and cardiovascular toxicities, the acute toxicity of tentacle-only extract (TOE) from the jellyfish Cyanea capillata was observed in mice, and hematological indexes were examined in rats. The median lethal dose (LD(50)) of TOE was 4.25 mg/kg, and the acute toxicity involved both heart- and nervous system-related symptoms. Arterial blood gas indexes, including pH, PCO(2), HCO(3) (-), HCO(3)std, TCO(2), BEecf and BE (B), decreased significantly. PO(2) showed a slight increase, while SO(2)c (%) had no change at any time. Na(+) and Ca(2+) decreased, but K(+) increased. Biochemical indexes, including LDH, CK, CK-MB, ALT, AST and sCr, significantly increased. Other biochemical indexes, including BUN and hemodiastase, remained normal. Lactic acid significantly increased, while glucose, Hct% and THbc showed slight temporary increases and then returned to normal. These results on the acute toxicity and hematological changes should improve our understanding of the in vivo pathophysiological effects of TOE from C. capillata and indicate that it may also have neurotoxicity, liver toxicity and muscular toxicity in addition to hemolytic and cardiovascular toxicities, but no kidney or pancreatic toxicity. 相似文献
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A. I. Mohamed H. L. Bhardwaj M. Rangappa G. Hoggard 《Plant foods for human nutrition (Dordrecht, Netherlands)》1995,47(1):29-38
Ozone sensitivity, nutritional quality, seed characteristics, and growth habit of beans (Phaseolus vulgaris L.) were evaluated in two seperate experiments. In the first experiment the data showed a significant variation among 34 bean accessions for ozone sensitivity following acute exposure of 18-day-old plants to 0.6 µl/l O3 for 2 hours under environmentally controlled greenhouse conditions. PI-163579, PI-169735, PI-171790, PI-176684, PI-201374, PI-310711, PI-345576, PI-370569, PI-379435, and PI-414831 were identified as tolerant to acute ozone exposures. Protein, oil, starch, sugar, and ash contents in the seed of selected germplasm were determined and no correlation was found between these components and ozone sensitivity. Seed size and growth habit varied considerably among the 34 accessions but were not correlated to ozone sensitivity. In a second experiment, ten accessions, selected from the tolerant ones identified in the first experiment, were subjected to chronic ozone exposure in open-top chambers at 0.04 and 0.08 µl/l concentrations for 7 hours/day 44 days after transplanting. Based on foliar injury and yield reductions, only PI-370569 and PI-414831 were tolerant to prolonged ozone exposure (0.08 µl/l). A significant positive correlation (r=0.83) existed between foliar injury rating from chronic treatments involving 0.04 and 0.08 µl O3/l and acute exposure (0.6 µl O3/1/2 hours). The data indicated that acute ozone exposure can be used to initially screen a large number of bean accessions, however, this is an imperfect indicator of ozone sensitivity with chronic exposure.Agricultural Research Station Journal Article Series, No. 191. The use of any trade name varieties and/or vendors does not imply the exclusion of other products or vendors that may also suitable. 相似文献
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Adrian S. Siregar Marie Merci Nyiramana Eun-Jin Kim Soo Buem Cho Min Seok Woo Dong Kun Lee Seong-Geun Hong Jaehee Han Sang Soo Kang Deok Ryong Kim Yeung Joon Choi Dawon Kang 《Marine drugs》2021,19(11)
Models created by the intraperitoneal injection of lipopolysaccharide (LPS) and D-galactosamine (D-GalN) have been widely used to study the pathogenesis of human acute liver failure (ALF) and drug development. Our previous study reported that oyster (Crassostrea gigas) hydrolysate (OH) had a hepatoprotective effect in LPS/D-GalN-injected mice. This study was performed to identify the hepatoprotective effect of the tyrosine-alanine (YA) peptide, the main component of OH, in a LPS/D-GalN-injected ALF mice model. We analyzed the effect of YA on previously known mechanisms of hepatocellular injury in the model. LPS/D-GalN-injected mice showed inflammatory, apoptotic, ferroptotic, and pyroptotic liver injury. The pre-administration of YA (10 mg/kg or 50 mg/kg) significantly reduced the liver damage factors. The hepatoprotective effect of YA was higher in the 50 mg/kg YA pre-administered group than in the 10 mg/kg YA pre-administered group. These results showed that YA had a hepatoprotective effect by reducing inflammation, apoptosis, ferroptosis, and pyroptosis in the LPS/D-GalN-injected ALF mouse model. We suggest that YA can be used as a functional peptide for the prevention of acute liver injury. 相似文献
17.
安全性毒理学评价是研究食品安全的重要手段。本文综述了与普洱茶有关的安全性毒理学评价研究,为认识普洱茶安全性提供参考。急性经口毒性实验显示普洱茶的半致死率（LD50）大于5β000βmg·kg-1,属于实际无毒级别;28βd或90βd经口毒性试验发现普洱生、熟茶提取物无明显不良效应的剂量分别是1β250和5β000βmg·kg-1·d-1;遗传毒性研究表明普洱茶对原核细胞、真核细胞和生殖细胞均无致突变性;普洱茶的生殖毒性和发育毒性无效应剂量水平是700βmg·kg-1·d-1;普洱茶对小鼠肝细胞的毒性极小或无;人体急性、亚急性毒性研究均未观察到病理改变。综上,已有安全性毒理学评价研究显示普洱茶具有较高的饮用安全性。 相似文献
18.
The effects of simultaneously varying P, K, lime and Mo supplies on the growth and shoot morphology of white clover ( Trifolium repens ) at establishment were investigated in a factorially designed glasshouse experiment. Phosphorus and lime applications had almost identical, additive, effects on dry-matter (DM) production, and it was clear that the benefit of both treatments lay in the resultant improvements in plant available P. The adverse effects of P deficiency on young plants resulted, immediately, in a large decrease in stolon branch numbers, but only when the deficiency became acute did similar declines in the dimensions of leaves and petioles occur. It was suggested that this preferential maintenance of leaf and petiole expansion processes under moderate P deficiency, by enabling white clover to retain favourable upper canopy positions, could be an ecological adaptation to maximize its chances of survival in mixed grass–clover swards. Unlike P, K had little effect on clover growth or shoot morphology. However, there was some evidence that plants suffering from acute K deficiency preferentially partitioned resources to organs associated with exploratory growth, i.e. to stolons, at the expense of the plant's photosynthetic capability. Molybdenum application had no effect on DM production or shoot morphology, but did improve the N status of shoots, presumably by enhancing N2 fixation. It was concluded that the survival of white clover in swards at establishment is critically dependent on P supply, and that one of the main benefits of liming is the resultant improvement in P availability. 相似文献
19.
蚯蚓是土壤健康的关键指示生物,为了更好地评价草甘膦对土壤无脊椎动物的影响,本研究采用土壤法测定草甘膦对蚯蚓的急性毒性;用不同浓度的草甘膦分别测定不同暴露时间下对蚯蚓超氧化物歧化酶、过氧化氢酶、过氧化物酶、谷胱甘肽S转移酶、乙酰胆碱酯酶活性的影响。结果显示,土壤法测定草甘膦对蚯蚓的LC50>1000 mg/kg;在草甘膦的影响下,随着暴露时间的延长,蚯蚓SOD酶活力有着先增高后下降的趋势,CAT酶活力呈现着先下降后升高的趋势,随着时间和浓度的增长POD酶活力在草甘膦的影响下有逐渐下降的趋势;相对于空白对照,处理组AChE酶活力在草甘膦暴露14 d时显著降低。研究结果将为合理评价和监测草甘膦造成的土壤污染水平提供科学依据。 相似文献
20.
A modified stress index is proposed that accounts for both chronic and acute water stress. Current trapezoid methods that use vegetation cover and temperature indices do not necessarily measure chronic conditions. The modified method describes the chronic stress as the ratio of actual crop cover to its potential expressed such that zero stress occurs when actual cover equals or exceeds the potential as determined by a simulation model. The advantage of such a definition is that in areas where full groundcover is rarely achieved, such as semi-arid regions, a more realistic and conservative stress condition will be observed. Airborne thermal and multispectral images were acquired at four growth stages of a wheat crop from a site in Victoria, Australia with experimental plots having rain-fed and irrigated regimes over two seasons (2005 and 2006). The theoretical basis of vector determination was adopted for trapezoidal extent per season. The relationship between such chronic stress and acute stress is explored and show that in any 2 years large differences between these stresses exist. 相似文献