Temporal Association Between Pulmonary Inflammation and Antioxidant Induction Following Hyperoxic Exposure of the Preterm Guinea Pig

The time course and nature of the pulmonary inflammatory and antioxidant responses, both during and after hyperoxic-induced acute lung injury were studied in the preterm guinea pig. Three-day preterm (65 days gestation) guinea pigs were randomly exposed to either 21% O₂ (control) or 95% O₂ (hyperoxia) for 72 hours. All pups were then maintained in ambient conditions for up to a further 11 days, during which time lung damage was monitored. In animals exposed to hyperoxia, evidence of acute lung injury and inflammation was characterized by a marked increase in microvascular permeability and elevated numbers of neutrophils in bronchoalveolar lavage fluid. Protein concentration, elastase-like activity and elastase-inhibitory capacity in lavage fluid were at a maximum at the end of the 72 hours hyperoxic exposure. Four days later, all values had returned to control levels. In contrast, increased numbers of neutrophils, macrophages and lymphocytes were recovered in the lavage fluid during this early recovery period. Coinciding with the influx of inflammatory cells, there was a significant increase in glutathione peroxidase, manganese superoxide dismutase and catalase activities in immature lung. Lung copper/zinc superoxide dismutase activity remained unchanged during both experimental periods. The strong temporal relationship between the influx of inflammatory cells to the lung and the induction of pulmonary antioxidant enzyme defences suggests that a common mechanism underlies both responses. These findings have led us to regard inflammation in the hyperoxic-injured immature lung as a beneficial event and not, as previously suggested, as part of the injurious process.     

The effect of copper on glutathione metabolism in human leukocytes

Leukocytes incubated with Cu(II) showed a decrease in both glutathione reductase activity and reduced glutathione content. The glucose 6-phosphate dehydrogenase activity under the same conditions was not affected. Serum albumin added to mixtures prevented the loss of enzyme activity, whiled-penicillamine andl-histidine had little effect. Prior oxidation of the cell-reduced glutathione did not diminish the enzyme inhibitory action of Cu(II). The amount of regeneration of reduced glutathione in leukocytes previously treated with diamide to oxidize their reduced glutathione was a function of Cu(II) concentration in the media. No evidence was obtained that elevated serum ceruloplasmin levels in rabbits, nor incubation of leukocytes in vitro with ceruloplasmin, affect leukocyte glutathione reductase activity. It was proposed that the major mechanism by which copper affects glutathione metabolism in leukocytes is by inhibition of glutathione reductase.     

Studies on the origin of the near-infrared (800–900 nm) absorption of cytochrome c oxidase

Data are presented which were collected in the course of the past ten years and bear on the correlation of absorbance at 800 nm and the EPR signal at g = 2 (‘copper signal’) of cytochrome c oxidase in various states of oxidation and ligation. Both EPR and optical reflectance spectra were obtained at low temperature (?170 to ?190°C). For some sets of samples spectra were recorded in the range 500–1100 nm. A particular effort was made to study this correlation with what are called ‘mixed valence’ states (Greenwood, C., Wilson, M.T. and Brunori, M. (1974) Biochem. J. 137, 205–215), when cytochrome a and the EPR-detectable copper are thought to be oxidized and the other components reduced and vice versa. These data show no evidence that the copper component of cytochrome oxidase which has so far not been detected by EPR makes a contribution to the absorption between 800 and 900 nm exceeding 10–15% of the total, which is close to or within the error of the respective measurements. For the various states of the oxidase examined in this work the 700–800 nm region did not appear to be more useful than the 800–900 nm region for determining the state of the EPR-undetectable copper in a reliable way. These conclusions are in agreement with results presented previously from other laboratories concerning the relationship of optical (approx. 800 nm) and EPR spectroscopic (g = 2) data obtained with the enzyme.     

壳聚糖改性竹炭对铜吸附性能研究

为了提高竹炭去除废水中重金属离子能力,采用交联法设计合成新型的磁性壳聚糖改性竹炭复合吸附剂,并采用傅里叶红外光谱对改性竹炭复合吸附剂进行表征,同时开展不同Cu2+初始浓度、吸附剂投加量、吸附时间、pH和温度等因素对Cu2+吸附去除率的影响。结果表明,吸附效率与Cu2+初始浓度和吸附剂投加量成正效应;吸附平衡时间约8 h;在作用温度范围内,吸附效率随温度升高而上升;pH为7时吸附效果最好。振荡条件吸附效果优于静置处理。该结果为废水重金属深度处理及水环境保护提供依据。     

Development of a novel chemiluminescence method for the determination of cefazolin sodium in injectable powder and human urine based on a luminol‐Cu(III) complex reaction in alkaline medium

A novel chemiluminescence (CL) method was developed for the determination of cefazolin sodium based on the CL reaction between the [Cu(HIO₆)₂]^5‐Cu(III) complex and luminol in alkaline solution. Results showed that CL emission of Cu(III) complex–luminol in alkaline medium was significantly different from that in acidic medium. A possible mechanism of the enhanced effect of cefazolin on CL emission of the [Cu(HIO₆)₂]^5‐‐ luminol system was proposed. The effect of the reaction conditions on CL emissions was examined. Under optimized conditions, a good linear relationship was obtained between CL intensity and concentrations of cefazolin sodium in the range of 2.0 x 10^‐8 to 2.0 x 10^‐6 g/mL with a correlation coefficient of R² = 0.9978. The limit of detection was 4.58 x 10^‐9 g/mL. The proposed method was applied for the determination of cefazolin sodium in real samples with recoveries of 82.0‐109% with an RSD of 0.7‐2.1%. The proposed method was successfully used for the determination of cefazolin sodium in injectable powder preparations and human urine with satisfactory results. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis,Characterization, and Evaluation of Five Coordinated Copper(II) Complexes as Antibacterial,Artificial Nuclease,and Sod Mimics

The copper(II) complexes with ciprofloxacin (CFLH), levofloxacin (LFLH), norfloxacin (NFLH), and neutral bidentate ligands have been synthesized and characterized. The complexes have been evaluated for their antibacterial activity against selective species. Complexes have been also checked for their interacting behavior with DNA, and were found to have two different modes of interaction, classical and partial intercalation. Tested complexes were found to be better antioxidants with their IC₅₀ values ranging from 0.51 to 0.97 μM.     

Cu3P Binary Phosphide: Synthesis via a Wet Mechanochemical Method and Electrochemical Behavior as Negative Electrode Material for Lithium‐Ion Batteries

Mechanochemical synthesis of Cu₃P in the presence of n‐dodecane results in a material with a secondary particle size distribution of 10 μm, secondary particles which consist of homogeneously agglomerated 20 nm primary particles. The electrochemical performance of Cu₃P with lithium is influenced by the reaction depth, in other words by the lower potential cut‐off. During the electrochemical reaction, the displacement of copper by lithium from the Cu₃P structure until the formation of Li₃P and Cu deteriorates the capacity retention. Improved performance was obtained when the charge potential was limited to 0.50 V (vs. Li/Li⁺) and the formation of the Li_xCu_3‐xP phase (0 ≤ × ≤ 2). In this case, when the potential is limited to 0.5 V, the capacity is stable for more than 50 cycles. Acceptable electrochemical performances in Li‐ion cells within the voltage range 0.50–2.0 V (vs. Li/Li⁺) were shown when Cu₃P was used as an anode and Li_1.2(Ni_0.13Mn_0.54Co_0.13)O₂ and LiNi_0.5Mn_1.5O₄ as positive electrode materials.     

Fibrillation of human serum albumin shows nonspecific coordination on stoichiometric increment of Copper(II)

Protein aggregation is related to a series of pathological disorders the main cause of which are the fibrillar species generated during the process. Human serum albumin (HSA) undergoes rapid fibrillation in the presence of Cu(II) at pH 7.4 in 60% ethanol after 6-h incubation (～65?°C) followed by room temperature incubation. Here, we have investigated the effect of a stoichiometric variation of Cu(II) on the self-assembly of HSA using Congo red and thioflavin T dye-binding studies, circular dichroism spectroscopy, Fourier transform infrared spectroscopy, electron paramagnetic resonance spectroscopy, fluorescence microscopy and transmission electron microscopy. The simulation of EPR spectra suggests that with the increment in Cu(II) ion concentration, there is a change in ligand field coordination. Kinetic parameters indicate reduced cooperativity that may be related to the nonspecific coordination on increment of Cu(II) concentration. Cu(II) is also able to direct the accumulation of a large number of fibers along with a formation of dense fibrillar network which is evident from microscopic images.     

Health applications of bioactive compounds from marine microalgae

Marine microalgae and cyanobacteria are very rich in several chemical compounds and, therefore, they may be used in several biological applications related with health benefits, among others. This review brings the research up-to-date on the bioactive compounds produced by marine unicellular algae, directly or indirectly related to human health. It covers and goes through the most studied applications of substances such as PUFA, sterols, proteins and enzymes, vitamins and pigments, in areas so diverse as human and animal nutrition, therapeutics, and aquaculture. The great potential of marine microalgae and the biocoumpounds they produce are discussed in this review.