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1.
Engineered nanomaterials, defined as having at least one dimension smaller than 100 nm, have revolutionized many technology sectors ranging from therapeutics and diagnostics to environmental monitoring and remediation. This has resulted in a rapid increase in their manufacture over the past few years, accompanied by an increased human exposure potential. However, understanding of the interactions of nanomaterials with biological systems is still rudimentary. We have described that an environmentally and medically relevant nano metal (cerium dioxide) can affect primary human monocyte viability and interact with programmed cell death pathways leading to apoptosis and autophagic cell death. Cerium dioxide nanoparticles (CeO2 NPs)-induced autophagy acts as a prodeath mechanism and leads to increased cytotoxicity of human monocytes. A better understanding of the implication and biological significance of CeO2 NPs-induced autophagy and apoptosis will help us understand the risks associated with its uses and develop safer nanomedicine. 相似文献
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Early detection of slime production may be useful for clinical decision because of its suggestive property for potential pathogenic
capacity of a Candida strain especially in patients with a prosthetic device. In this study we aimed to compare the visual tube method (VTM) with
transmission electron microscopy (TEM) in order to confirm the reliability of the former method. In order to demonstrate the
reproducibility of the tube method and to determine the correct timing for the test, Candida isolates directly obtained from blood culture (DBC) bottles and their two subsequent subcultures were used. The results of
this study showed that VTM is a simple and reliable method which can be used in every clinical mycology laboratory, provided
that the test is applied on DBC isolates; as the ability of slime production is decreased or lost even after the first subculturing.
We suggest that this simple method can be used and may have some contributions to the ongoing studies on the controversial
issue concerning removal of biomaterials in candidemic patients. 相似文献
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We investigated the effect of α-melanocyte stimulating hormone (α-MSH) on endotoxin-induced intestinal inflammation and the role of nitric oxide and prostaglandins in this response. α-MSH treatment (25 μg/rat, intraperitoneally (i.p.); twice daily) reduced the severity of the lesions macroscopically and microscopically. This protective effect was found to be confined mainly to the distal ileum. These lesions were reversed by pretreatment with the non-selective COX inhibitor indomethacin (10 mg/kg, subcutaneously (s.c.)) but not by the selective COX-2 inhibitor nimesulide (3 mg/kg, s.c.), the NO donor sodium nitroprusside (4 mg/kg, i.v.) or the iNOS inhibitor dexamethasone (3 mg./kg, i.p.) at macroscopic level and reversed by Indo or Dex at microscopic level. Increased peroxidase activity -index of tissue neutrophil infiltration- in the distal ileum of LPS-treated rats was decreased by α-MSH and this effect was reversed by pretreatment with Indo. In conclusion, the neuropeptide α-MSH has a beneficial effect on endotoxin-induced distal intestinal lesions by a mechanism which probably involves nitric oxide and COX-1 derived prostaglandins. 相似文献
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The effect of alpha-melanocyte stimulating hormone on endotoxin-induced intestinal injury. 总被引:1,自引:0,他引:1
We investigated the effect of alpha-melanocyte stimulating hormone (alpha-MSH) on endotoxin-induced intestinal inflammation and the role of nitric oxide and prostaglandins in this response. alpha-MSH treatment (25 microg/rat, intraperitoneally (i.p.); twice daily) reduced the severity of the lesions macroscopically and microscopically. This protective effect was found to be confined mainly to the distal ileum. These lesions were reversed by pretreatment with the non-selective COX inhibitor indomethacin (10 mg/kg, subcutaneously (s.c.)) but not by the selective COX-2 inhibitor nimesulide (3 mg/kg, s.c.), the NO donor sodium nitroprusside (4 mg/kg, i.v.) or the iNOS inhibitor dexamethasone (3 mg./kg, i.p.) at macroscopic level and reversed by Indo or Dex at microscopic level. Increased peroxidase activity -index of tissue neutrophil infiltration- in the distal ileum of LPS-treated rats was decreased by alpha-MSH and this effect was reversed by pretreatment with Indo. In conclusion, the neuropeptide alpha-MSH has a beneficial effect on endotoxin-induced distal intestinal lesions by a mechanism which probably involves nitric oxide and COX-1 derived prostaglandins. 相似文献
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Kristo G Yoshimura Y Keith BJ Stevens RM Jahania SA Mentzer RM Lasley RD 《American journal of physiology. Heart and circulatory physiology》2004,287(6):H2746-H2753
The purpose of this study was to determine whether the adenosine A1/A2a receptor agonist AMP-579 induces acute and delayed preconditioning against in vivo myocardial stunning. Regional stunning was produced by 15 min of coronary artery occlusion and 3 h of reperfusion (RP) in anesthetized open-chest pigs. In acute protection studies, animals were pretreated with saline, low-dose AMP-579 (15 microg/kg iv bolus 10 min before ischemia), or high-dose AMP-579 (50 microg/kg iv at 14 microg/kg bolus + 1.2 microg.kg(-1).min(-1) for 30 min before coronary occlusion). The delayed preconditioning effects of AMP-579 were evaluated 24 h after administration of saline vehicle or high-dose AMP-579 (50 microg/kg iv). Load-insensitive contractility was assessed by measuring regional preload recruitable stroke work (PRSW) and PRSW area. Acute preconditioning with AMP-579 dose dependently improved regional PRSW: 129 +/- 5 and 100 +/- 2% in high- and low-dose AMP-579 groups, respectively, and 78 +/- 5% in the control group at 3 h of RP. Administration of the adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (0.7 mg/kg) blocked the acute protective effect of high-dose AMP-579, indicating that these effects are mediated through A1 receptor activation. Delayed preconditioning with AMP-579 significantly increased recovery of PRSW area: 64 +/- 5 vs. 33 +/- 5% in control at 3 h of RP. In isolated perfused rat heart studies, kinetics of the onset and washout of AMP-579 A1 and A2a receptor-mediated effects were distinct compared with those of other adenosine receptor agonists. The unique nature of the adenosine agonist AMP-579 may play a role in its ability to induce delayed preconditioning against in vivo myocardial stunning. 相似文献
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Alexia J. Taylor Christina D. McClure Kelly A. Shipkowski Elizabeth A. Thompson Salik Hussain Stavros Garantziotis Gregory N. Parsons James C. Bonner 《PloS one》2014,9(9)
Background
Multi-walled carbon nanotubes (MWCNTs) pose a possible human health risk for lung disease as a result of inhalation exposure. Mice exposed to MWCNTs develop pulmonary fibrosis. Lung macrophages engulf MWCNTs and produce pro-fibrogenic cytokines including interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and osteopontin (OPN). Atomic layer deposition (ALD) is a novel process used to enhance functional properties of MWCNTs, yet the consequence of ALD-modified MWCNTs on macrophage biology and fibrosis is unknown.Methods
The purpose of this study was to determine whether ALD coating with aluminum oxide (Al2O3) would alter the fibrogenic response to MWCNTs and whether cytokine expression in human macrophage/monocytes exposed to MWCNTs in vitro would predict the severity of lung fibrosis in mice. Uncoated (U)-MWCNTs or ALD-coated (A)-MWCNTs were incubated with THP-1 macrophages or human peripheral blood mononuclear cells (PBMC) and cell supernatants assayed for cytokines by ELISA. C57BL6 mice were exposed to a single dose of A- or U-MWCNTs by oropharyngeal aspiration (4 mg/kg) followed by evaluation of histopathology, lung inflammatory cell counts, and cytokine levels at day 1 and 28 post-exposure.Results
ALD coating of MWCNTs with Al2O3 enhanced IL-1β secretion by THP-1 and PBMC in vitro, yet reduced protein levels of IL-6, TNF-α, and OPN production by THP-1 cells. Moreover, Al2O3 nanoparticles, but not carbon black NPs, increased IL-1β but decreased OPN and IL-6 in THP-1 and PBMC. Mice exposed to U-MWCNT had increased levels of all four cytokines assayed and developed pulmonary fibrosis by 28 days, whereas ALD-coating significantly reduced fibrosis and cytokine levels at the mRNA or protein level.Conclusion
These findings indicate that ALD thin film coating of MWCNTs with Al2O3 reduces fibrosis in mice and that in vitro phagocyte expression of IL-6, TNF-α, and OPN, but not IL-1β, predict MWCNT-induced fibrosis in the lungs of mice in vivo. 相似文献9.
We present the optical emission studies of the ammonium nitrate plasma produced by the fundamental (1064 nm) and second (532 nm) harmonics of a Q-switched Nd: YAG laser. The target material was placed in front of the laser beam in an open atmospheric air. The spectrum reveals numerous transitions of neutral nitrogen. We have studied the spatial behavior of the plasma temperature (T e ) and electron number density (N e ) determined using the Boltzmann plot method and Stark broadened line profiles, respectively. Besides, we have studied the variation of the plasma parameters as a function of the laser irradiance. 相似文献
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