Changes in Histopathology, Enzyme Activities, and the Expression of Relevant Genes in Zebrafish (Danio rerio) Following Long-Term Exposure to Environmental Levels of Thallium.

Thallium is a rare-earth element, but widely distributed in water environments, posing a potential risk to our health. This study was designed to investigate the chronic effects of thallium based on physiological responses, gene expression, and changes in the activity of relevant enzymes in adult zebra fish exposed to thallium at low doses. The endpoints assessed include mRNA expression of metallothionein (MT)2 and heat shock protein HSP70; enzymatic activities of superoxide dismutase (SOD) and Na+/K+-ATPase; and the histopathology of gill, gonad, and liver tissues. The results showed significant increases in HSP70 mRNA expression following exposure to 100 ng/L thallium and in MT2 expression following exposure to 500 ng/L thallium. Significantly higher activities were observed for SOD in liver and Na+/K+-ATPase activity in gill in zebra fish exposed to thallium (20 and 100 ng/L, respectively) in comparison to control fish. Gill, liver, and gonad tissues displayed different degrees of damage. The overall results imply that thallium may cause toxicity to zebra fish at environmentally relevant aqueous concentrations.

[Study of symbolic element in roasting slag of pyrite by inductively coupled plasma mass spectrometry].

In the present paper, the correlations between sixteen elements from the dry method roasted dust-slag of pyrite and sixteen elements from the soil layer near and far from the store area were studied by ICP-MS. Similar radio and outstanding different radio of the elements between the dust-slag and the soil were studied too. It was discovered that in the pollution soil layer Tl, Cd, Cs, Cu, Zn, Mn, Pb and Ni were easy to be identified and had similar radio with the elements in the dust-slag. But only Tl, Cd, Zn and Ni are suitable for criterion of element similar properties. In dust-slag and soil, distinct composition element radios of Tl, Cs, Co, Mo, Zn, Cr, V, Sr, Sb, Pb, Rb, Mn and Ni had striking differentiation. Only Tl, V, Sb and Cu corresponded to both the uncorrelated elements analysis of surface layer and middle-base layer soil. Tl could be used as an inspection target of similar elements and outstanding different elements between the dust-slag and the soil in the meanwhile. So we suggested that Tl can be used as a symbolic element in the roasting dust-slag of pyrite to find the dust-slag of pyrite in dust-recognition and to differentiate the metallurgy dust of pyrite and soil dust.

Tissue specific cytotoxicity of colon cancer cells mediated by nanoparticle-delivered suicide gene in vitro and in vivo.

PURPOSE: This study aimed to develop an efficient and safe strategy to introduce suicide genes into colon cancer cells. EXPERIMENTAL DESIGN: In this study, we fused an enhanced carcinoembryonic antigen promoter (CEA) to a suicide gene, cytosine deaminase (CD). This construct was delivered into colon cancer cells using calcium phosphate nanoparticles (CPNP). The cells were then treated with the prodrug 5-FC. The therapeutic effect was evaluated in vitro and in vivo. RESULTS: Our study showed that the CEA promoter-driven, CPNP-delivered suicide gene was only expressed in CEA-positive colon cancer cells, and resulted in significant cytotoxicity after administration of the prodrug 5-FC in vitro. Moreover, our in vivo study showed that CPNP-mediated CEA-CD delivery, together with 5-FC treatment, resulted in significant tumor growth delay in xenograft human colon carcinoma. CONCLUSIONS: Our study indicates that the combination of CPNP and CEA-CD gene expression represents a novel approach for CEA-positive tumor gene therapy.

Study on oxidation of pyrite by in situ absorption spectroscopy.

Pyrite is one of the common natural mineral. It is easily oxidized and brings heavy metal contaminations, therefore it is the main source of acidity mine drainage. The study on the dynamics of pyrite is helpful to comprehending the mechanism of its pollution. In the present paper, an experimental method was designed that phenanthroline reacts with Fe2+ that is released from pyrite in solution, and produces stable orange-red complex compound. It can be detected by absorption spectroscopy. In-situ characterization of oxidation of pyrite can be achieved by this method. The results showed that the method is reliable and accurate, and it has high sensitivity and little interference; the reaction rate of oxidation increased linearly with time, corresponding to the characterization of zero-order reaction; oxidation of pyrite belongs to the surface reaction and the process of surface reaction is rate determining step.

Quantitative proteomic analysis of differential proteins in the stroma of nasopharyngeal carcinoma and normal nasopharyngeal epithelial tissue.

The importance of stromal cells and the factors that they expressed during cancer initiation and progression have been highlighted by recent literature. To identify the stromal proteins involved in nasopharyngeal carcinoma (NPC) carcinogenesis, we assessed differences in protein expression of the stroma from NPC and normal nasopharyngeal epithelium tissues (NNET) using a quantitative proteomic approach combined with laser capture microdissection (LCM). LCM was performed to purify stromal cells from the NPC and NNET, respectively. The differential proteins between the pooled microdissected tumor and normal stroma were analyzed by two-dimensional difference gel electrophoresis (2D-DIGE) combined with mass spectrometry (MS). Twenty differential proteins were identified, and the expression and location of two differential proteins (L-plastin and S100A9) were further confirmed by Western blotting and immunohistochemical analysis. Our results will be helpful to study the role of stroma in the NPC carcinogenesis, as well as discover the interaction between NPC cells and their surrounding microenvironment.

Role of GAC63 in transcriptional activation mediated by beta-catenin.

Beta-catenin is a key mediator in the canonical Wnt signaling pathway, which plays important roles in multiple developmental processes. Inappropriate activation of this pathway leads to developmental defects and development of certain cancers. Upon Wnt signaling, beta-catenin binds TCF/LEF transcription factors. The TCF/LEF-beta-catenin complex then recruits a variety of transcriptional coactivators to the promoter/enhancer region of Wnt-responsive genes and activates target gene transcription. In this article, we demonstrate that GRIP1-associated coactivator 63 (GAC63), a recently identified nuclear receptor (NR) coactivator, interacts with beta-catenin. The N-terminus of GAC63 is the binding site for beta-catenin, whereas a C-terminal fragment of beta-catenin including armadillo repeats 10-12 binds to GAC63. Over-expression of GAC63 enhanced the transcriptional activity of beta-catenin, and also greatly enhanced TCF/LEF-regulated reporter gene activity in a beta-catenin-dependent manner. Endogenous GAC63 was recruited to TCF/LEF-responsive enhancer elements when beta-catenin levels were induced by LiCl. In addition, reduction of endogenous GAC63 level by small interfering RNA (siRNA) inhibited TCF/LEF-mediated gene transcription. Our findings reveal a new function of GAC63 in transcriptional activation of Wnt-responsive genes.

[Characterization of kale (Brassica oberacea var acephala) under thallium stress by in situ attenuated total reflection FTIR].

The experiment was designed based on consumption of carbon dioxide through the photosynthesis of Brassica oberacea var acephala leaf, and the photosynthesis of kale leaf under thallium stress was investigated by in situ attenuated total reflection FTIR (in situ ATR-FTIR). The ATR-FTIR showed that the absorption peaks of leaves had no obvious difference between plants growing in thallium stress soil and plants growing in non-thallium pollution soil, and the strong peaks at 3,380 cm(-1) could be assigned to the absorption of water, carbohydrate, protein or amide; the strong peaks at 2,916 and 2,850 cm(-1) assigned to the absorption of carbohydrate or aliphatic compound; the peaks at 1,640 cm(-1) assigned to the absorption of water. However, as detected by the in situ ATR-FTIR, the double peaks (negative peaks) at 2,360 and 2,340 cm(-1) that are assigned to the absorption of CO2 appeared and became high gradually. It was showed that kale was carrying photosynthesis. At the same time, the carbon dioxide consumption speed of leaf under thallium stress was obviously larger than that of the blank It was expressed that photosynthesis under thallium stress was stronger than the blank All these represented that kale had certain tolerance to the heavy metal thallium. Meanwhile, the carbon dioxide consumption of grown-up leaf was more than that of young leaf whether or not under thallium stress. It was also indicated that the intensity of photosynthesis in grown-up leaf is higher than that in young leaf.

[A spectral analysis method for total volatile base nitrogen].

A new method for the determination of the total volatile basic nitrogen (TVB-N) by reflectance spectroscopy was developed. The method was based on the reaction of TVB-N with Nessler's reagent treated by molecular sieve and the reflectance-absorption value F(R), which is directly proportional to the amount of NH2 Hg IO in solid phase, was measured by the reflection spectrometer. The fundamental principle, effective factors and experimental conditions of the method were discussed. The special features of this method were its simplicity in operation, relatively high sensitivity of determination and the use of a small amount of reagent. Linear calibration graph was obtained in the range 1-8 microg x mL(-1) with a detection limit of 0.1 microg x mL(-1). The method was applied to monitor the fresh degree of fish and pork. The result discovered that the total volatile basic nitrogen increased rapidly along with the time extension, indicating that the deterioration of fish and pork was an acceleration process, and the deterioration speed of fish was faster than that of pork.

GAC63, a GRIP1-dependent nuclear receptor coactivator.

Nuclear receptors (NRs) regulate target gene transcription through the recruitment of multiple coactivator complexes to the promoter regions of target genes. One important coactivator complex includes a p160 coactivator (GRIP1, SRC-1, or ACTR) and its downstream coactivators (e.g., p300, CARM1, CoCoA, and Fli-I), which contribute to transcriptional activation by protein acetylation, protein methylation, and protein-protein interactions. In this study, we identified a novel NR coactivator, GAC63, which binds to the N-terminal region of p160 coactivators as well as the ligand binding domains of some NRs. GAC63 enhanced transcriptional activation by NRs in a hormone-dependent and GRIP1-dependent manner in transient transfection assays and cooperated synergistically and selectively with other NR coactivators, including GRIP1 and CARM1, to enhance estrogen receptor function. Endogenous GAC63 was recruited to the estrogen-responsive pS2 gene promoter of MCF-7 cells in response to the hormone. Reduction of the endogenous GAC63 level by small interfering RNA inhibited transcriptional activation by the hormone-activated estrogen receptor. Thus, GAC63 is a physiologically relevant part of the p160 coactivator signaling pathway that mediates transcriptional activation by NRs.

[Determination of trace mercury in hair by hydride generation atomic fluorescence spectrometry].

A method for determination of trace mercury in hair by hydride generation atomic fluorescence spectrometry under normal or high temperature and high humidity condition was described. The ways of samples pretreatment, analysis and rapid clearing up bad memory were researched. The results showed: that the effect of instability of mercury can be cushioned under high temperature and high humidity condition by choosing much negative high pressure and control long the fluorescence intensity of standard blank. There weren't evident differences in the measure results of standard graph, standard and sample between normal and high temperature and high humidity conditions. When the reducer concentration was more than 2.5 percent or less than 1.5 percent the fluorescence signal was often overrun or disappeared. The sensitivity and stability of instrument weren't easily balanced. Due to sulfuric acid remainder, the fluorescence intensity of sample blank was higher than that of standard blank, especially under high temperature and high humidity, so in the proceed of sample pretreatment sulfuric acid was used scarcely. The bad memory effect can be cleared up rapidly by correction of negative high pressure and correction of of timized standard graph. The method was rapid and accurate. The relative standard deviation (RSD) was equal to or small than 1.1%. The detection limit of the method was 0.006 ng x mL(-1).

[Characterization of oxidation on pyrite by in situ attenuated total reflection-Fourier transform infrared spectroscopy].

Pyrite is one of common natural minerals in the environment, which is easily oxidated and is the main source of acidity mine drainage (AMD). The study on the oxidation of pyrite is helpful to comprehend the mechanism of its pollution. In the present paper, the oxidation of pyrite under the condition of air and water was respectively investigated by the attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) through the designing experiment on the formation of carbon dioxide by the reaction of carbonate in pyrite with sulfuric acid formed by the oxidation of pyrite. The CO2 measurement by in situ ATR indicated that the oxidation rate of pyrite both in the air and in water both reduced by time and the latter reduced more obviously than the former, which indicates that the oxidation rate of pyrite in water is slower than that in the air. In the ATR measurement, the double absorption peaks at 2 350 cm(-1) that indicates CO2 have high selectivity, and permits the in situ analysis.

[Application of ICP-MS in evaluating element contamination in soils].

The Yunfu pyrite was the second biggest pyrite bed in the world. Plants using industrial ore of the Yunfu pyrite are distributed in many sections across the country. In the present paper, elements V, Cr, Co, Cu, Zn, Mo, Cd, Sb, Rb and Cs in soil profiles in slag disposing area of a sulfuric acid plant using industrial ore of theYunfu pyrite were studied. A method for simultaneously determination of metals and some reference elements in soils by ICP-MS was developed. The correlations between the metals and their reference elements were fast found. Enrichment factors were applied for evaluating the degree of soil contamination, and the problem about choosing contamination elements background values was pointed out. The results indicated that element V showed apparent and serious pollution, The Co showed middle degree pollution, and there has been a trend of apparent pollution. The Cr, Mo and Cd showed pollution between light degree and middle degree. The Zn and Sb showed light degree pollution, and there was a latent trend of middle degree pollution. The Cu showed light degree pollution. The high enrichment points of the V and the Cr were observed in the upper part (4.0-10.5 cm) and deep part of soil profiles (44.0-75.5 cm). Those of Co and Mo were found in the surface of soil profiles (0-5.0 cm), middle-upper part (9.5-10.5 cm) and middle part (29.5-46.0 cm), while those of Cd and Cu occurred just in the middle of soil profiles (29.5-46.0 cm). The formation of highly enrichment points of contamination elements in the soil profiles was the result of leaching and accumulating effect of the metals released from slag and the residual metals of highly weathered red soils. Most of pollution of V in the soil was contributed by the V in soil bed. Part of the V pollution in the soil was supplied by leaching and accumulating effect of the V which came from catalyst with lost activity in sulfuric acid production volatilizing into slag.

The protective effects of rutaecarpine on acute pancreatitis.

Acute pancreatitis (AP) is the acute inflammation of the pancreas. The morbidity of AP has increased in recent years. Certain patients eventually develop severe AP (SAP), which rapidly progresses to multiple organ dysfunction; the incidence of this occurring in patients with AP is 20-30%. To date, no specific drugs or methods exist to treat this disease. Rutaecarpine relaxes vascular smooth muscle by stimulating calcitonin gene-related peptide (CGRP) release via activation of vanilloid receptor subtype 1 (VR1). It has been demonstrated that rutaecarpine induces a therapeutic effect on SAP. The present study was conducted to characterize the molecular mechanisms underlying the protective effects of rutaecarpine against AP using a rat model of AP. Gross pathological changes of the pancreas, as well as the pancreatic tissue histopathological score, were assessed following treatment with rutaecarpine, capsazepine or a combination of the two. Serum amylase activity was detected using an automatic biochemistry analyzer. Changes in the serum concentrations of interleukin (IL)-6, tumor necrosis factor (TNF-α), IL-10 and CGRP were assessed by ELISA and radioimmunoassay. The results demonstrated that pre-treatment with rutaecarpine markedly decreased pancreatic inflammation and necrosis, reduced the volume of ascites, and significantly increased the plasma concentration of CGRP and the serum concentration of IL-10, an anti-inflammatory cytokine. However, serum concentrations of the inflammatory cytokines IL-6 and TNF-α were decreased. The effect of rutaecarpine treatment markedly improved with increases in the drug dose. Capsazepine, as a competitive vanilloid receptor antagonist, abolished these protective effects of rutaecarpine against AP. Therefore, the results of the present study indicate that rutaecarpine protects against AP in rats by upregulating endogenous CGRP release via activation VR1 of, to improving the microcirculation of the pancreatic tissue and regulate the expression of inflammatory factors.

[The surface adsorption and selective catalytic reaction of NO on Cu-ZSM-5 using in situ DRIFTS].

The prepared Cu-ZSM-5 catalyst presents higher activity at low temperature during the selective catalytic reduction (SCR) of NO, and the conversion from NO to N2 is 70.6% at 613 K. The in situ diffuse reflectance FTIR spectroscopy (in situ DRIFTS) is an important method for studying surface adsorption of catalyst and mechanism of catalytic reaction, and was used to study the surface adsorbed species and the selective catalytic reduction reaction of NO on Cu-ZSM-5 catalyst in the presence of propene as reductant, with excess O2 and at 298-773 K. Based on the in-situ DRIFTS, a reaction mechanism is proposed that on Cu-ZSM-5, NO is first transformed to a series of NO(x) surface adsorbates, then these species react with the activating species of propene (C(x)H(y) or C(x)H(y)O(x)) to form organo-intermediates, including a process from organo-NH to organo-CN again to organo-NO(x) (organo-nitro or organo-nitrito), and finally these key intermediates react to form nitrogen. The role of Cu is to promote NO(x) content. Propene is easily activated on Cu-ZSM-5 with oxygen, and furthermore, the presence of oxygen is necessary to form organo-NO(x) intermediates.

[Spectroscopic characterization of heavy metal wastewater treatment by pyrite].

Treatment of acidic heavy metal wastewater by pyrite was studied by reflectance spectroscopy and absorption spectroscopy. The surface reaction in pyrite and the interaction between pyrite and heavy metal were investigated. The diffuse reflectance FTIR spectroscopy (DRIFTS) showed that the surface hydroxyls in pyrite reacted with heavy metal ion in the process of wastewater treatment, and furthermore, the phenomenon of the acidic wastewater driven to neutrality(pH 7) naturally after treatment was reasonably explained by analyzed carbonate in pyrite. The reflectance spectroscopy in visible region can be used to characterize the change of mineral particle and specific surface in this treatment process, and the reasons for the activity of pyrite increasing in repetitive use were explained. A process of adsorption-precipitation from Cr ( VI) to Cr3+ and to Cr(OH)3 was proved by absorption spectroscopy and XPS during the treatment of Cr(VI)-bearing wastewater by pyrite.

[In situ diffuse reflectance FTIR spectroscopy characterization of titanium silicalite-1 catalytic oxidization of styrene].

The Stability of framework of titanium silicalite-1 (TS-1) was investigated by high temperature diffuse reflectance FT-IR spectroscopy (DRIFTS), and the results showed that the 960 cm(-1) peak belonging to Ti-framework was stabilized at 673 K, but the two peaks belonging to framework shifted to lower frequencies by about 13 cm(-1) at 673 K. The effect on the framework after H2O2 adsorption was discussed. The results showed that the 960 cm(-1) peak lowered and shifted to high frequencies by about 11 cm(-1), but it recovered with vacuum or heating up. It was suggested that the 960 cm(-1) peak characterizes Ti==O, and this explained why the 960 cm(-1) peak shifted to high frequencies well. TS-1 catalytic oxidization of styrene was investigated by in situ DRIFTS. The reaction process was detected and phenyl aldehyde was the main product. Based on in situ analysis, it was proposed that H2O2 was adsorbed on Ti in framework of TS-1 to form active center.

[Reflectance spectroscopic characterization of thallium wastewater treatment by pyrite and pyrite slag].

The surface hydroxyls in pyrite and slag were investigated, and the result showed that the hydroxyls in pyrite slag were induced by residual pyrite. The diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) indicated that the surface hydroxyls in pyrite and slag reacted with thallium ion in the process of wastewater treatment. The 3 550 cm(-1) peak and 3 402 cm(-1) peak weakened after pyrite and slag treatment, nevertheless the 3 550 cm(-1) peak lowered and shifted to higher frequencies by about 70 cm(-1) with slag treatment. The reflectance spectroscopy in visible region was used to characterize the change of particle and specific surface in these treatment process, and furthermore, the fact that the activity of both pyrite and slag increased in repetitive use was explained.

[Study on phase distribution and release of heavy metal in pyrite using sequential extraction procedure and ICP-MS].

Heavy metal elements of V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Mo, Cd, Sb, Ba and Pb were determined by ICP-MS. The linear ranges of determination for these elements were obtained, and the correlation coefficients were larger than 0.997. The detection limit ranges were from 0.005 to 0.01 microg x L(-1) and the RSDs were lower than 5%. Phase distributions of heavy metals in pyrite were analyzed by ICP-MS with sequential extraction procedure. The result showed that Pb was the main heavy metal in pyrite and its total content was 830 mg x kg(-1). Pb existed mostly in carbonate or galena (PbS) phase of pyrite and the proportion was 56.9%. Pb existed less in iron oxides with 29.7% in proportion, and least in sulfide and silicate with 3.5% and 9.9%, respectively. The release of Pb in pyrite was primary in natural environment, but the release of Cr and Cd was not be ignorable, too.

Tissue specific expression of suicide genes delivered by nanoparticles inhibits gastric carcinoma growth.

Developing an efficient and safe strategy to introduce a therapeutic gene into targeting cells in vivo is a key issue in cancer gene therapy nowadays. Novel non-viral gene carriers, such as nanoparticles, have been shown to be able to deliver DNA into cancer cells efficiently. Suicide gene therapy has been demonstrated to be effective in inhibiting tumor growth, however, the lack of tumor specificity limits its application in clinic. Developing a targeting system for suicide gene is an attractive strategy in cancer gene therapy. In this study, the CMV enhancer and carcinoembryonic antigen (CEA) promoter was fused to a chimeric suicide gene yCDglyTK. This construct was delivered into SGC7901 gastric cancer cells using calcium phosphate nanoparticles (CPNPs). The expression of yCDglyTK in SGC7901 cells was confirmed by RT-PCR and western blot. Immunofluorescence experiments showed that yCDglyTK is only expressed in CEA-positive cancer cells, but not in CEA-negative cells. The expression of yCDglyTK induced cancer cell death following the addition of the prodrug 5-FC, and also elicit "bystander effect" to kill the neighboring cells. Intratumoral injection of CPNP-yCDglyTK complex followed by administration of 5-FC produced marked regression in gastric cancer xenografts. Taken together, our study suggests that the combination of calcium phosphate nanoparticles and suicide gene therapy represents a novel approach for targeting gastric cancer gene therapy.

[The reflection spectrometer and quantitative analysis design].

The reflection spectrometer with optical fibre transmission was designed and used in quantitative analysis. The reflection spectrometry was applied to the determination of reducing sugar in samples based on the reduction reaction of the reducing sugar with Fehling's reagent. The reduction reaction was carried out in a micro-reaction cell, and the reddish colored Cu2O produced was settled at the bottom of the reaction cell. The reflectance R(infinity), which is directly proportional to the amount of Cu2O produced, was measured by the reflection spectrometer. The fundamental principle, effect factors, and experimental conditions of the method were discussed. Linear relationship was obtained in the range of 20-120 microg of reducing sugar. The special features of this method were its simplicity in operation, relatively high sensitivity of determination, and the use of small amount of reagent. Satisfactory results were obtained in its application to the analysis of wine and honey samples.