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  • 机译 镉损害HepG2细胞中的p53活性
    摘要:Cadmium and cadmium compounds are contaminants of the environment, food, and drinking water and are important constituents of cigarette smoke. Cd exposure has also been associated with airborne particulate CdO and with Cd-containing quantum dots in medical therapy. Adverse cadmium effects reported in the literature have stimulated during recent years an ongoing discussion to better elucidate cadmium outcomes at cell and molecular level. The present work is designed to gain an insight into the mechanism of p53 impairment at gene and protein level to understand Cd-induced resistance to apoptosis. We used a hepatoma cell line (HepG2) derived from liver, known to be metal responsive. At genotoxic cadmium concentrations no cell cycle arrest was observed. The p53 at gene and protein level was not regulated. Fluorescence images showed that p53 was correctly translocated into the nucleus but that the p21Cip1/WAF-1, a downstream protein of p53 network involved in cell cycle regulation, was not activated at the highest cadmium concentrations used. The miRNAs analysis revealed an upregulation of mir-372, an miRNA able to affect p21Cip1/WAF-1 expression and promote cell cycle progression and proliferation. The role of metallothioneins and possible conformational changes of p53 are discussed.
  • 机译 动态直接暴露方法在体外柴油机毒性测试中的验证
    摘要:Diesel exhaust emission is a major health concern because of the complex nature of its gaseous content (e.g., NO2, NO, CO, and CO2) and high concentration of particulate matter (PM) less than 2.5 μm which allows for deeper penetration into the human pulmonary system upon inhalation. The aim of this research was to elucidate the potential toxic effects of diesel exhaust on a human pulmonary-based cellular system. Validation of a dynamic direct exposure method for both laboratory (230 hp Volvo truck engine) and field (Volkswagen Passat passenger car) diesel engines, at idle mode, was implemented. Human pulmonary type II epithelial cells (A549) grown on porous membranes were exposed to unmodified diesel exhaust at a low flow rate (37.5 mL/min). In parallel, diesel emission sampling was also conducted using real-time air monitoring techniques. Induced cellular effects were assessed using a range of in vitro cytotoxicity assays (MTS, ATP, and NRU). Reduction of cell viability was observed in a time-dependent manner following 30–60 mins of exposure with NRU as the most sensitive assay. The results suggest that the dynamic direct exposure method has the potential to be implemented for both laboratory- and field-based in vitro toxicity studies of diesel exhaust emissions.
  • 机译 钙通道在重金属毒性中的作用
    摘要:The role of voltage-dependent Ca channels (VDCC) in the membrane permeation of two toxic metals, lead (Pb) and cadmium (Cd), was studied in mammalian cells. Both metals interact with Ca-binding sites, but, while Cd influx appears to occur mainly through the same pathways as Ca, Pb is also rapidly taken up by different passive transport systems. Furthermore, I compared the effect of Cd in two Chinese hamster ovary (CHO) cell lines, a wild-type and a modified cell line, which were permanently transfected with an L-type VDCC. When cultures were subjected to a brief (30–60 min) exposure to 50–100 μM Cd, apoptotic features, metal accumulation, and death were comparable in both cell lines although, in transfected cells, the effect of Cd treatment was partially prevented by nimodipine (VDCC antagonist) and enhanced by BayK8644 (VDCC agonist). Thus, expression of L-type Ca channels is not sufficient to modify Cd accumulation and sensitivity to a toxicological significant extent and while both Cd and Pb can take advantage of VDCC to permeate the membrane, these transport proteins are not the only, and frequently not the most important, pathways of permeation.
  • 机译 长期接触对鱼类致死毒性影响的减少寿命模型
    摘要:A model based on the concept of reduction in life expectancy (RLE model) as a result of long term exposure to toxicant has been developed which has normal life expectancy (NLT) as a fixed limiting point for a species. The model is based on the equation (LC50 = a ln(LT50) + b) where a and b are constants. It was evaluated by plotting ln LT50 against LC50 with data on organic toxicants obtained from the scientific literature. Linear relationships between LC50 and ln LT50 were obtained and a Calculated NLT was derived from the plots. The Calculated NLT obtained was in good agreement with the Reported NLT obtained from the literature. Estimation of toxicity at any exposure time and concentration is possible using the model. The use of NLT as a reference point is important since it provides a data point independent of the toxicity data set and limits the data to the range where toxicity occurs. This novel approach, which represents a departure from Haber's rule, can be used to estimate long term toxicity from limited available acute toxicity data for fish exposed to organic biocides.
  • 机译 L-NAME抑制一氧化氮合酶促进顺铂诱导的雄性大鼠肾毒性。
    摘要:Objective. Nitric oxide (NO) has numerous important functions in the kidney. The role of NO in cisplatin (CP)-induced nephrotoxicity is not completely understood. This study was designed to determine the role of NO synthase inhibitor (L-NAME) on the severity of CP-induced nephrotoxicity in rats. Methods. Sixty four male (M) and female (F) Wistar rats were randomly divided into eight groups. The sham groups (group 1, male, n = 6 and group 2, female, n = 6) received saline. Groups 3 (male, n = 8) and 4 (female, n = 8) were treated with L-NAME (4 mg/kg, i.p.), and groups 5 (male, n = 8) and 6 (female, n = 8) received CP (3 mg/kg) for 7 days. Groups 7 (male, n = 8) and 8 (female, n = 8) were treated with L-NAME and CP for 7 days. Results. The CP-alone treated rats showed weight loss and increase in serum levels of blood urea nitrogen (BUN) and creatinine (Cr). Coadministration of L-NAME and CP did not improve weight loss, and it increased the levels of BUN and Cr in male but not in female rats (P < 0.05). CP alone increased kidney damage significantly (P < 0.05 ), however, the damage induced by combination of CP and L-NAME was gender-related. Conclusion. NOS inhibition by L-NAME increased CP-induced nephrotoxicity, which was gender-related.
  • 机译 对小鼠模型中从Haffkine抗毒液中毒化的眼镜蛇眼镜蛇(黑眼镜蛇眼镜蛇)的交叉反应性
    摘要:Naja sumatrana is the dominant cobra species in Malaysia, Singapore, Borneo, and Sumatra, and it does not have specific antivenom. The Haffkine antivenom has been advocated instead. This study aims to determine the efficacy of this antivenom against Naja sumatrana envenoming using a mouse model. Methods. Male Swiss albino mice were used. Intravenous LD50 was first determined separately for Naja naja and Naja sumatrana venom. ED50 was determined by preincubating antivenom with each venom at 2.5 LD50 before administering the mixture into the tail vein. Validation was carried out using a challenge test. Each mouse received 111 µg of Naja sumatrana venom intramuscularly followed by intraperitoneal administration of dilute Haffkine antivenom. Survival was recorded 24 hours after envenoming. Results. The LD50 of Naja naja venom was 78.13 µg, standard error (SE) 13.3 µg. The ED50 of the Haffkine antivenom against Naja naja venom was 45.9 mg, SE 7.5 mg. The LD50 and ED50 of Naja sumatrana venom were 55.5 µg, SE 12.0 µg; and 73.9 mg, SE 12.0 mg, respectively. The intra-peritoneal ED50 against 111 µg intramuscular Naja sumatrana venom was 136.95 mg, SE 36.74 mg. Conclusion. The Haffkine polyvalent antivenom exhibited cross-neutralisation against Naja sumatrana venom when used at a higher dose.
  • 机译 纳米氧化锌诱导人肺细胞毒性。
    摘要:Zinc oxide nanoparticles (ZnO-NPs) are increasingly used in sunscreens, biosensors, food additives, pigments, rubber manufacture, and electronic materials. With the wide application of ZnO-NPs, concern has been raised about its unintentional health and environmental impacts. This study investigates the toxic effects of ZnO-NPs in human lung cells. In order to assess toxicity, human lung epithelial cells (L-132) were exposed to dispersion of 50 nm ZnO-NPs at concentrations of 5, 25, 50, and 100 μg/mL for 24 h. The toxicity was evaluated by observing changes in cell morphology, cell viability, oxidative stress parameters, DNA damage analysis, and gene expression. Exposure to 50 nm ZnO-NPs at concentrations between 5 and 100 μg/mL decreased cell viability in a concentration-dependent manner. Morphological examination revealed cell shrinkage, nuclear condensation, and formation of apoptotic bodies. The oxidative stress parameters revealed significant depletion of GSH level and increase in ROS levels suggesting generation of oxidative stress. ZnO-NPs exposure caused DNA fragmentation demonstrating apoptotic type of cell death. ZnO-NPs increased the expression of metallothionein gene, which is considered as a biomarker in metal-induced toxicity. To summarize, ZnO-NPs cause toxicity in human lung cells possibly through oxidative stress-induced apoptosis.
  • 机译 砷对黑胶的毒性及其磷化改良作用
    摘要:The toxicity of arsenic in soil and ground water is one of the most important environmental problems particularly in South-East Asia. Arsenic-polluted irrigation water creates hazard in soil environment and also in crop quality. In the present study, response of black gram (Vigna mungo L.) to arsenic with or without phosphate application was investigated. Arsenic-treated plants showed reduction in their growth and pigment content. Arsenic significantly enhanced lipid peroxidation, electrolyte leakage, and level of proline showing oxidative stress. Arsenic toxicity was associated with an increase in the activities of antioxidative enzymes like superoxide dismutase, peroxidase, and ascorbate peroxidase whereas catalase activity decreased at higher arsenic dose. Joint application of phosphate with arsenic resulted in significant alterations in most of the parameters tested under the purview of arsenic treatment alone which lead to better growth in black gram.
  • 机译 苯代谢物对人精子功能的细胞毒性作用:体外研究
    摘要:In recent years, individuals are rampantly exposed to vapours of benzene, through paint, plastic, petroleum industries, fuel exhaust, and tobacco smoke. Hence the present investigation was directed towards determining the effect of benzene metabolites, namely, phenol-hydroquinone and catechol, on the motility, viability, and nuclear integrity of the human spermatozoa. From the results obtained it was clear that exposure to phenol-hydroquinone caused a significant decline in both, sperm motility and viability. Exposure to a phenol-hydroquinone (Phase I) microenvironment may therefore inhibit metabolically active enzymes, thus impeding ATP production, and in turn lowers sperm motility and viability. In addition, the present study also revealed that both metabolites of benzene caused significant denaturation of sperm nuclear DNA. Hence, exposure to phenol-hydroquinone in vitro could have resulted in generation of free radicals and altered membrane function, which is reflected by a decline in the motility, viability, and loss of sperm nuclear DNA integrity. In Phase II, the exposure of human sperm in vitro to varied concentrations of catechol caused only insignificant changes in sperm motility and viability as compared to those observed on exposure to phenol-hydroquinone. Hence, exposure to catechol appeared to have less toxic effects than those of phenol-hydroquinone.
  • 机译 三氯蔗糖对多种环境细菌的抑菌作用
    摘要:Sucralose was developed as a low-cost artificial sweetener that is nonmetabolizable and can withstand changes in pH and temperature. It is not degraded by the wastewater treatment process and thus has been found in waste water, estuaries, rivers and the Gulf Stream. Since the molecule can withstand heat, acidification, and microbial degradation, it is accumulating in the environment. The highest concentration of environmental sucralose detected to date is 300 ng/L. Our lab has isolated six bacterial species from areas that have been exposed to sucralose. We then cultured these isolates in the presence of sucralose looking for potential sucralose metabolism or growth acceleration. Instead we found something very interesting, bacteriostatic effects exhibited on all six isolates. This inhibition was directly proportional to the concentration of sucralose exposure. The efficiency of the growth inhibition seemed to be species specific, with various concentrations inhibiting each organism differently.
  • 机译 单萜(+)-Camphene,p-Cymene和乙酸香叶酯在实验模型中的抗伤害感受活性和氧化还原谱
    摘要:Objective. To evaluate antinocicpetive and redox properties of the monoterpenes (+)-camphene, p-cymene, and geranyl acetate in in vivo and in vitro experimental models. Methods. Evaluation of the in vitro antioxidant activity of (+)-camphene, p-cymene, and geranyl acetate using different free radical-generating systems and evaluation of antinociceptive actions by acetic acid-induced writhing and formalin-induced nociception tests in mice. Results. p-Cymene has the strongest antinociceptive effect, but (+)-camphene and geranyl acetate also present significant activity at high doses (200 mg/kg). (+)-Camphene had the strongest antioxidant effect in vitro at TBARS and TRAP/TAR assays and also had the highest scavenging activities against different free radicals, such as hydroxyl and superoxide radicals. Sodium nitroprussiate-derived NO production was enhanced by (+)-camphene. Geranyl acetate and p-cymene also presented some antioxidant effects, but with a varying profile according the free radical-generating system studied. Conclusion. (+)-Camphene, p-cymene, and geranyl acetate may present pharmacological properties related to inflammation and pain-related processes, being potentially useful for development of new therapeutic strategies, with limited possibilities for p-cymene and geranyl acetate.
  • 机译 通过汗液生物监测和消除全氟化合物和多氯联苯:血液,尿液和汗液的研究
    摘要:Perfluorinated compounds (PFCs) are man-made organofluorine chemicals manufactured and marketed for their stain-resistant properties. Polychlorinated biphenyls (PCBs) are anthropogenic organochlorine compounds previously used in various industrial and chemical applications prior to being banned in the Western world in the 1970s. Both PFCs and PCBs are persistent contaminants within the human organism and both have been linked to adverse health sequelae. Data is lacking on effective means to facilitate clearance of PFCs and PCBs from the body. Methods. Blood, urine, and sweat were collected from 20 individuals (10 healthy participants and 10 participants with assorted health problems) and analyzed for PFCs and PCBs using high performance liquid chromatography tandem mass spectrometry. Results. Some individual PCB congeners, but not all, were released into sweat at varying concentrations. None of the PFCs found in serum testing appeared to be excreted efficiently into perspiration. Conclusions. Induced perspiration may have some role in facilitating elimination of selected PCBs. Sweat analysis may be helpful in establishing the existence of some accrued PCBs in the human body. Sweating does not appear to facilitate clearance of accrued PFHxS (perfluorohexane sulfonate), PFOS (perfluorooctane sulfonate), or PFOA (perfluorooctanoic acid), the most common PFCs found in the human body.
  • 机译 修改乙酰半胱氨酸市场授权对扑热息痛过量治疗的影响
    摘要:In September 2012, the Medicines and Healthcare products Regulatory Agency (MHRA) substantially amended the Marketing Authorisation for acetylcysteine following an extensive review. The present study examined the impact of this license change on patterns of acetylcysteine use in patients presenting to hospital after paracetamol (acetaminophen) overdose. Between September 2011 and April 2013, 785 consecutive patients presented to York Hospital due to paracetamol overdose, and a before-after analysis was used to compare outcomes. There were 483 patients before and 302 patients after the license amendment, and age, gender, acute or staggered overdose pattern, and dose were similar in both groups. In the patients with paracetamol concentrations between the “100-line” and “200-line,” a significantly higher proportion received acetylcysteine treatment (51% before versus 98% after, P = 0.0029), as expected. A modest increase was also observed in relation to late or staggered overdose or cases where the time of ingestion was uncertain (53% versus 74%, P = 0.0430). The median duration of hospital stay increased across the entire study population, from 15 to 24 hours (P = 0.0159) due to the increased proportion of patients requiring acetylcysteine treatment. The findings indicate that the MHRA amendment is a financially costly intervention, and further studies are needed to examine clinical outcomes so that its cost effectiveness might be addressed.
  • 机译 加拿大西部城市社区的对羟基苯甲酸酯水平
    摘要:With effective antibacterial and antifungal properties, commercially used parabens are synthetic compounds widely utilized as preservatives in cosmetics, personal care products, pharmaceuticals, and as an additive in some foodstuffs. While long regarded as relatively safe and nontoxic, recent research has demonstrated xenoestrogenic properties of anthropogenic parabens with early evidence that paraben exposure may be linked to breast cancer, thyroid dysfunction, allergy, and obesity. In an attempt to determine the prevalence of paraben exposure in a Canadian urban community, a sample of convenience was done by measuring urinary levels of methyl, ethyl, propyl, butyl, and isobutyl parabens (MP, EP, PP, BP, and IP) in 39 consecutive patients in an Alberta primary care clinic. In 28 female patients including 9 pregnant women, the median urinary levels (in μg/L) were 25.45 for MP, 10.17 for EP, 2.80 for PP, 0.30 for BP, and 0.24 for IP. In 11 male patients, the median urinary levels (in μg/L) were 25.95 for MP, 10.37 for EP, 3.09 for PP, 0.35 for BP, and 0.22 for IP. Especially high urinary paraben levels were reported in a few patients, with the highest urinary concentrations (in μg/L) reported as 966.46 for MP, 220.6 as EP, and 612.73 for PP. It is evident that exposure to assorted parabens is a routine event for many if not most individuals, including pregnant women, in urban Alberta, Canada.
  • 机译 薇甘菊提取物对烷基化剂诱导的遗传毒性的影响
    摘要:Medicinal plants are still widely used worldwide; yet for some species, little or no information is available concerning their biological activity, specially their genotoxic and antimutagenic potential. Mikania laevigata (Asteraceae) is a native plant from South America, and its extracts are largely used to treat respiratory complaints. The aim of the present work was then to evaluate, in vivo, the potential biological activity of M. laevigata on the genotoxicity induced by methyl methanesulfonate (MMS) and cyclophosphamide (CP), using the comet assay. Male CF1 mice were divided into groups of 5-6 animals, received by gavage 0.1 mL/10 g body wt of water, Mikania laevigata extract (MLE), MMS, and CP. Results showed that treatment with 200 mg/kg of the MLE previously to MMS and CP administration, respectively, reduced the damage index (DI) in 52% and 60%, when compared to DI at 24 h. Pretreatment also reduced the damage frequency (DF) in 56% (MMS) and 58% (CP), compared to DF at 24 h. MLE administration has been shown to protect mouse DNA from damage induced by alkylating agents; this corroborates to the biological activities of M. laevigata and points towards the need of plant compounds isolation to proceed with further studies.
  • 机译 杏仁,杏核,杏糖浆和杏仁糖浆中氰化物的潜在毒性水平
    摘要:Under normal environmental conditions, many plants synthesize cyanogenic glycosides, which are able to release hydrogen cyanide upon hydrolysis. Each year, there are frequent livestock and occasional human victims of cyanogenic plants consumption. The present work aims to determine the hydrocyanic acid content in different samples of cyanogenic plants, selected from the Tunisian flora, and in the almond syrup. In order to evaluate their toxicity and their impact on the consumer health in the short term as well as in the long term, using the ISO 2164-1975 NT standard, relating to the determination of cyanogenic heterosides in leguminous plants.
  • 机译 消胆胺和小球藻清除全氟化合物的胃肠道
    摘要:Background. While perfluorinated compounds (PFCs) are a family of commonly used synthetic compounds with many applications, some PFCs remain persistent within the human body due, in part, to enterohepatic recirculation and renal tubular reabsorption. With increasing recognition of potential harm to human health associated with PFC bioaccumulation, interventions to facilitate elimination of these toxicants are welcome in order to potentially preclude or overcome illness. Minimal research has been undertaken thus far on methods to accelerate human clearance of PFCs. Methods. To test for possible oral treatments to hasten PFC elimination, a group of individuals with elevated PFC levels was treated with cholestyramine (CSM) and, after a break, was subsequently treated with Chlorella pyrenoidosa (CP). Stool samples were collected from all participants (i) prior to any treatment, (ii) during treatment with CSM, and (iii) during treatment with CP. Results. With CSM treatment, significant levels of three distinct PFCs were found in all stools, while levels were mostly undetectable prior to treatment. Following treatment with oral CP, undetectable or very low levels of all PFCs were noted in each sample tested. Conclusion. CSM appears to facilitate elimination of some common PFCs and may have some role in the clinical management of patients with accrued PFCs.
  • 机译 NFκB途径的激活增强了肠道Caco-2细胞中AhR的表达。
    摘要:Recent data suggest that apart from its well-known role in the regulation of xenobiotic metabolizing enzymes, AhR is also involved in inflammation. However, the influence of inflammation on AhR expression remains unknown. Here, we demonstrated that proinflammatory conditions induced by either PMA or IL-1β enhance AhR expression in Caco-2 cells. This was associated with an increase in AhR promoter activity. By means of directed mutagenesis experiments and the use of proteasome inhibitors, we demonstrated that inflammation-induced AhR expression involved the NFκB pathway but not AP-1. Moreover, conditioned media from PMA-treated Caco-2 cells were also able to induce AhR expression, and this induction was repressed by anti-IL-1β blocking antibodies. Similar results were obtained with conditioned media from PMA-treated THP-1 cells. Taken together, these data suggest that AhR could be involved in vivo in an inflammatory loop. AhR was recently suspected to be implicated in inflammatory bowel disease. Our results support this hypothesis and suggest that AhR could be a new target for inflammatory bowel disease patient management.
  • 机译 NUTRALYS豌豆蛋白分离物的遗传毒理学评估
    摘要:NUTRALYS Pea Protein Isolate, a protein supplement, is a high-quality source of protein which is primarily emulsifying functional protein. We evaluated the genotoxic potential of NUTRALYS isolated from dry yellow pea, using three established genotoxicity tests (AMES test in vitro chromosomal aberration test, and in vivo micronucleus test) employing OECD guidelines under GLP conditions. In the bacterial reverse mutation test, NUTRALYS did not show positive responses in strains detecting point and frame shift mutations. In the chromosomal aberration test, NUTRALYS did not induce chromosome aberrations in the presence and absence of metabolic activation. In the bone marrow micronucleus test, NUTRALYS did not induce significant increases of micronucleated immature (polychromatic) erythrocytes in bone marrow of test animals.
  • 机译 用于健康风险评估的工程纳米材料的安全性评估:使用原始和功能化碳纳米管的实验性分层测试方法
    摘要:Increasing application of engineered nanomaterials within occupational, environmental, and consumer settings has raised the levels of public concern regarding possible adverse effects on human health. We applied a tiered testing strategy including (i) a first in vitro stage to investigate general toxicity endpoints, followed by (ii) a focused in vivo experiment. Cytotoxicity of laboratory-made functionalized multiwalled carbon nanotubes (CNTs) (i.e., MW-COOH and MW-NH2), compared to pristine MWCNTs, carbon black, and silica, has been assessed in human A549 pneumocytes by MTT assay and calcein/propidium iodide (PI) staining. Purity and physicochemical properties of the test nanomaterials were also determined. Subsequently, pulmonary toxic effects were assessed in rats, 16 days after MWCNTs i.t. administration (1 mg/kg b.w.), investigating lung histopathology and monitoring several markers of lung toxicity, inflammation, and fibrosis. In vitro data: calcein/PI test indicated no cell viability loss after all CNTs treatment; MTT assay showed false positive cytotoxic response, occurring not dose dependently at exceedingly low CNT concentrations (1 μg/mL). In vivo results demonstrated a general pulmonary toxicity coupled with inflammatory response, without overt signs of fibrosis and granuloma formation, irrespective of nanotube functionalization. This multitiered approach contributed to clarifying the CNT toxicity mechanisms improving the overall understanding of the possible adverse outcomes resulting from CNT exposure.

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