Phytoremediation of triazophos by Canna indica Linn. in a hydroponic system

The phytoremediation of triazophos (O, O-diethyl-O-(1-phenyl-1, 2, 4-triazole-3-base) sulfur phosphate, TAP) by Canna indica Linn. in a hydroponic system was studied. After 21 d of exposure, the removal kinetic constant (K) of TAP was 0.0229-0.0339 d(-1) and the removal percentage of TAP was 41-55% in the plant system and the K and removal percentage of TAP were about 0.002 d(-1) and 1%, respectively, in darkness and disinfected control. However, the K and removal percentage of TAP were 0.006 d(-1) and approximately 11%, respectively, in the treatment with eluate from the media of constructed wetland. The contribution of plant to the remediation of TAP was 74% and C. indica played the most important role in the hydroponic system. Under the stress of TAP and without inorganic phosphorus nutrient, the activity of phosphatase in the plant system increased and phytodegradation was observed. The production and release of phosphatase is seen as the key mechanism for C. indica to degrade TAP. C. indica, which showed the potential of phytoremediation of TAP, and is commonly used in constructed wetland, so the technique of phytoremediation of TAP from contaminated water can be developed with the combination of constructed wetland.

Molecular cloning and characterization of carp (Cyprinus carpio L.) CD8 beta and CD4-like genes

Partial cDNA sequences of both CD8 beta and CD4-like (CD4L) genes of common carp (Cyprinus carpio L.) were isolated from thymus cDNA library by the method of suppression subtractive hybridization (SSH). Subsequently the full length cDNAs of carp CD8 and CD4L were obtained by means of 3' RACE and 5' RACE, respectively. The full length cDNA of carp CD8 is 1164 bp and encodes 207 amino acids including a signal peptide region of 24 amino acids, a transmembrane region of 23 amino acids from aa 167 to aa189 and an immunoglobulin V-set from aa 19 to aa 141. Similar to other species CD8 beta s,carp CD8 beta also lacks p56(lck) domain in the cytoplasmic region. The full length cDNA of carp CD4L is 2001 bp and encodes 458 amino acids including four immunoglobulin (Ig)-like domains in the extracellular region, a transmembrane region of 23 amino acids at the C-terminal region from aa 402 to aa 424 and a cytoplasmic tail. Similar to mammalian, avian CD4s and fugu CD4L, carp CD4L also has the conserved p56(lck) tyrosine kinase motif (C-X-C) in the cytoplasmic region. RT-PCR analysis demonstrated that carp CD8 beta and CD4L genes were both expressed predominantly in thymus. The results from this study can be used to understand the evolution of both the CD8 beta and CD4 molecules which can be used as markers for cytotoxic and helper T cells in carp. (c) 2007 Published by Elsevier Ltd.

Prediction and elucidation of the population dynamics of Microcystis spp. in Lake Dianchi (China) by means of artificial neural networks

Lake Dianchi is a shallow and turbid lake, located in Southwest China. Since 1985, Lake Dianchi has experienced severe cyanabacterial blooms (dominated by Microcystis spp.). In extreme cases, the algal cell densities have exceeded three billion cells per liter. To predict and elucidate the population dynamics ofMicrocystis spp. in Lake Dianchi, a neural network based model was developed. The correlation coefficient (R 2) between the predicted algal concentrations by the model and the observed values was 0.911. Sensitivity analysis was performed to clarify the algal dynamics to the changes of environmental factors. The results of a sensitivity analysis of the neural network model suggested that small increases in pH could cause significantly reduced algal abundance. Further investigations on raw data showed that the response of Microcystis spp. concentration to pH increase was dependent on algal biomass and pH level. When Microcystis spp. population and pH were moderate or low, the response of Microcystis spp. population would be more likely to be positive in Lake Dianchi; contrarily, Microcystis spp. population in Lake Dianchi would be more likely to show negative response to pH increase when Microcystis spp. population and pH were high. The paper concluded that the extremely high concentration of algal population and high pH could explain the distinctive response of Microcystis spp. population to +1 SD (standard deviation) pH increase in Lake Dianchi. And the paper also elucidated the algal dynamics to changes of other environmental factors. One SD increase of water temperature (WT) had strongest positive relationship with Microcystis spp. biomass. Chemical oxygen demand (COD) and total phosphorus (TP) had strong positive effect on Microcystis spp. abundance while total nitrogen (TN), biological oxygen demand in five days (BOD5), and dissolved oxygen had only weak relationship with Microcystis spp. concentration. And transparency (Tr) had moderate positive relationship with Microcystis spp. concentration.

Apoptosis induction on human hepatoma cells Hep G2 of decabrominated diphenyl ether (PBDE-209)

Polybrominated diphenyl ethers (PBDEs) are an important class of halogenated organic brominated flame retardants. Because of their presence in abiotic and biotic environments widely and their structural similarity to polychlorinated biphenyls (PCBs), concern has been raised on their possible adverse health effects to humans. This study was designed to determine the anti-proliferative, apoptotic properties of decabrominated diphenyl ether (PBDE-209), using a human hepatoma Hep G2 line as a model system. Hep G2 cells were cultured in the presence of PBDE-209 at various concentrations (1.0-100.0 mu mol/L) for 72 h and the percentage of cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The results showed that PBDE-209 inhibited the cells viability in time and concentration-dependent characteristics at concentrations (10.0-100.0 mu mol/L). We found that anti-proliferative effect of PBDE-209 was associated with apoptosis on Hep G2 cells by determinations of morphological changes, cell cycle and apoptosis. Mechanism study showed that PBDE-209 could increase the generation of intracellular reactive oxygen species (ROS) concentration-dependently. Antioxidant N-acetylcyteine partially inhibited the increase of ROS. The mechanism for its hepatoma-inhibitory effects was the induction of cellular apoptosis through ROS generation. In addition, activity of lactate dehydrogenase (LDH) release increased when the cells incubated with PBDE-209 at various concentrations and times. These results suggested that PBDE-209 had the toxicity activity of anti-proliferation and induction of apoptosis in tumor cells in vitro. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Mitochondrion-mediated apoptosis induced by Rana grylio virus infection in fish cells

A fish cell line, fathead minnow (FHM) cell, was used to investigate the alteration of mitochondrial dynamics and the mechanism of apoptosis under Rana grylio virus (RGV) infection. Microscopy observations, flow-cytometry analysis and molecular marker detection revealed the apoptotic fate of the RGV-infected cells. Some typical apoptotic characteristics, such as chromatin condensation, DNA fragmentation and mitochondrial fragmentation, were observed, and significantly morphological changes of mitochondria, including size, shape, internal structure and distribution, were revealed. The mitochondria in RGV-infected cells were aggregated around the viromatrix, and the aggregation could be blocked by colchicine. Moreover, the Delta psi m collapse was induced, and caspase-9 and caspase-3 were activated in the RGV-infected cells. In addition, NF-kappa B activation and intracellular Ca2+ increase were also detected at different times after infection. The data revealed the detailed dynamics of mitochondrion-mediated apoptosis induced by an iridovirus, and provided the first report on mitochondrial fragmentation during virus-induced apoptosis in fish cells.

Androgen receptor targets NFKB and TSPI to suppress prostate tumor growth in vivo

The androgen role in the maintenance of prostate epithelium is subject to conflicting opinions. While androgen ablation drives the regression of normal and cancerous prostate, testosterone may cause both proliferation and apoptosis. Several investigators note decreased proliferation and stronger response to chemotherapy of the prostate cancer cells stably expressing androgen receptor (AR), however no mechanistic explanation was offered. In this paper we demonstrate in vivo anti-tumor effect of the AR on prostate cancer growth and identify its molecular mediators. We analyzed the effect of AR on the tumorigenicity of prostate cancer cells. Unexpectedly, the AR-expressing cells formed tumors in male mice at a much lower rate than the AR-negative controls. Moreover, the AR-expressing tumors showed decreased vascularity and massive apoptosis. AR expression lowered the angiogenic potential of cancer cells, by increasing secretion of an anti-angiogenic protein, thrombospondin-1. AR activation caused a decrease in RelA, a subunit of the pro-survival transcription factor NF kappa B, reduced its nuclear localization and transcriptional activity. This, in turn, diminished the expression of its anti-apoptotic targets, Bcl-2 and IL-6. Increased apoptosis within AR-expressing tumors was likely due to the NF kappa B suppression, since it was restricted to the cells lacking nuclear (active) NF kappa B. Thus we for the first time identified combined decrease of NF kappa B and increased TSP1 as molecular events underlying the AR anti-tumor activity in vivo. Our data indicate that intermittent androgen ablation is preferable to continuous withdrawal, a standard treatment for early-stage prostate cancer. (C) 2007 Wiley-Liss, Inc.

Toxicity of microcystins in the isolated hepatocytes of common carp (Cyprinus carpio L.)

The toxicity of hepatotoxic microcystins produced mainly by Microcystis aeruginosa in mammals and fishes was well studied in recent years. However, there were scarcely reports in toxic effects of microcystins on isolated hepatocytes of fishes, especially investigation of microcystin-induced apoptosis and/or necrosis in carp hepatocytes. In the present study, the isolated hepatocytes of common carp were exposed to various concentrations of microcystins (0.01, 0.1, 1, 10, 100, 1000 mu g L-1) for 2, 4, 8, 16 and 24 h, respectively, and cytotoxicity of microcystins in the toxin-treated cells was determined. Results of this study showed that cytotoxicity of microcystins on carp hepatocytes was time and dose-dependent, and the approximate LC50 of microcystins in carp hepatocytes was 169.2 mu g L-1. The morphological changes typical of apoptosis, such as blebbing of cell membrane, condensation and fragmentation of cell nucleus were observed in the hepatocytes exposed to microcystins (1, 10 and 100 mu g L-1) using fluorescence and differential interference contrast microscopy. Agarose gel electrophoresis of DNA demonstrated a typical apoptotic "ladder pattern" in microcystin-treated hepatocytes after 16 h of exposure. Results of the present study indicated that the form of cell death in microcystin-treated hepatocytes depend on the exposure dose of toxin. When lower concentration of microcystins (10 and 100 mu g L-1) was used for exposure, carp hepatocytes died in apoptosis while, when higher one used (1000 mu g L-1), they died in the form of necrosis. (C) 2006 Elsevier Inc. All rights reserved.

Optimization of operational conditions in a submerged membrane bioreactor

In this study, optimization of operational conditions of a submerged membrane bioreactor treating municipal waste-water was studied. Mixed liquid suspended solid (MLSS), membrane flux (J(v)), aeration (Q), ratio of pumping, time to break time (t(p)/t(b)), and ratio of up flow area to down flow area (A Ad) were chosen as the easily manipulable parameters to study their effects on removal efficiency and membrane fouling. Totally, 16 different runs were designed to compare and select the best combination of the 5 parameters. The results showed that the optimal operational conditions were MLSS = 7g(.)L(-1), J(v) = 10L(.)m(-2.)h(-1), Q = 6 m(3.)h(-1), t(p)/t(b)= 4 min/1 min, and A(r)/A(d) = 1.7 m(2)/m(2). Under such conditions, the SMBR could achieve a double win of high removal efficiency and low membrane fouling.

FB1, an E2A fusion partner in childhood leukemia, interacts with U19/EAF2 and inhibits its transcriptional activity

Background: U19/EAF2 is a potential tumor suppressor exhibiting frequent down-regulation and allelic loss in advanced human prostate cancer specimens. U 19/EAF2 has also been identified as ELL-associated factor 2 (EAF2) based on its binding to ELL, a fusion partner of MLL in acute myeloid leukemia. U19/EAF2 is a putative transcription factor with a transactivation domain and capability of sequence-specific DNA binding. Methods: Yeast-two-hybrid-screening was used to identify U19/EAF2-binding partners. Co-immunoprecipitation and mammalian 1-hybrid assay were used to characterize a U19/EAF2-binding partner. Results: FB1, an E2A fusion partner in childhood leukemia, was identified as a binding-partner of U19/EAF2. FB1 also binds to EAF1, the only homologue of U19/EAF2. FB1 also interacts and co-localizes with ELL in the nucleus. Interestingly, FB1 inhibited the transcriptional activity of U19/EAF2 but not EAF1. Conclusions: FB1 is an important binding partner and a functional regulator of U19/EAF2, EAF1, and/or ELL. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Determinations of residual furazolidone and its metabolite, 3-amino-2-oxazolidinone (AOZ), in fish feeds by HPLC-UV and LC-MS/MS, respectively

The antibacterial drug furazolidone belonging to the group of nitrofuran antibacterial agents has been widely used as an antibacterial and antiprotozoal feed additive for poultry, cattle, and farmed fish in China. During application a large proportion of the administered drug may reach the environment directly or via feces. Although the use of furazolidone is prohibited in numerous countries, there are indications of its illegal use. It is known that furazolidone can be rapidly metabolized to 3-amino-2-oxazolidinone (AOZ) in the body of the target organism. In this study, a total of 21 fish feed samples, including 17 commercial fish feeds from local markets in China (representing 15 different formulations) and 4 fish feeds obtained from Germany and Turkey, respectively, are analyzed to determine whether the drug is still illegally used or commercially available feeds are contaminated by this drug. High-performance liquid chromatography (HPLC) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methods have been implemented to determine furazolidone and its metabolite AOZ in fish feeds containing animal protein, respectively. An efficient and convenient cleanup method for the determination of furazolidone in fish feeds is developed, and a simple cleanup method for the determination of AOZ is used. Method recoveries for samples used were determined as 87.7-98.3% for furazolidone at two spike levels of 2.0 and 5.0 ng g(-1) and as 95.6-102.8% for AOZ at spike levels of 0.4 and 0.8 ng g(-1). Limits of detections were 0.4 ng g(-1) for furazolidone and 0.05 ng g(-1) for AOZ. The established methods are therefore suitable for the determination of furazolidone and its metabolite AOZ in fish feeds at trace contamination levels. Using the established methods, all fish feed samples have been proved to be furazolidone negative; however, AOZ is tested in 16 of 17 fish feeds obtained from local markets in the Hubei province of China, with a positive rate as high as 94.1%.

Gastropods on submersed macrophytes in Yangtze lakes: Community characteristics and empirical modelling

Epiphytic gastropods in Yangtze lakes have suffered from large-scale declines of submersed macrophytes during past decades. To better understand what controls gastropod community, monthly investigations were carried out in four Yangtze lakes during December, 2001-March, 2003. Composed of 23 species belonging to Pulmonata and Prosobranchia, the community is characterized by the constitution of small individuals. The average density and biomass were 417 +/- 160 ind/m(2) and 18.05 +/- 7.43 g/m(2), with maxima a-round August. Submersed macrophyte biomass is shown to be the key factor affecting species number, density, and biomass of gastropods. Accordingly, a series of annual and seasonal models yielding high predictive powers were generated. Preference analyses demonstrated that pulmonates and prosobranchs with different respiratory organs prefer different macrophyte functional groups.

Identification of a WSSV neutralizing scFv antibody by phage display technology and in vitro screening

White spot syndrome virus (WSSV) is one of the most significant viral pathogens causing high mortality and economic damage in shrimp aquaculture. Although intensive efforts were undertaken to detect and characterize WSSV infection in shrimp during the last decade, we still lack methods either to prevent or cure white spot disease. Most of the studies on neutralizing antibodies from sera have been performed using in vivo assays. For the first time, we report use of an in vitro screening method to obtain a neutralizing scFv antibody against WSSV from a previously constructed anti-WSSV single chain fragment variable region (scFv) antibody phage display library. From clones that were positive for WSSV by ELISA, 1 neutralizing scFv antibody was identified using an in vitro screening method based on shrimp primary lymphoid cell cultures. The availability of a neutralizing antibody against the virus should accelerate identification of infection-related genes and the host cell receptor, and may also enable new approaches to the prevention and cure of white spot disease.

Photodegradation of 2-naphthol in aqueous solutions in the presence of humic acid and ferric ions

In this work, the photodegradation of the carcinogenic pollutant 2-naphthol in aqueous solution containing Aldrich humic acid (HA) and ferric ions (Fe(III)) under 125 W and 250 W high pressure mercury lamp (HPML, lambda >= 365 nm) irradiation was investigated. The photooxidation efficiencies were dependent on the pH values, light intensities and Fe(III)/HA concentration in the water, with higher efficiency at pHs 3-4, and 50 mu mol l(-1) Fe(III) with 20 mg l(-1) HA under 250 W HPML. The initial rate of photooxidation increases with increasing, the initial concentration of 2-naphthol from 10 mu mol l(-1) to 100 mu mol l(-1), while do not change at 50 and 100 mu mol l(-1). However, higher removal efficiency of 2-naphthol is achieved at its lower initial concentration of 10 mu mol l(-1), and initial rate of photooxidation is 0.193 mu mol l(-1) min(-1). Dissolved oxygen (DO) plays an important role in the system containing Fe(III)-HA complexes in which Fenton and photo-Fenton reactions were enhanced in the environment. Hydroxyl radicals produced in HA solution with or without ferric ions were determined by using benzene as free radical scavenger and phenol as scavenging products proportional to hydroxyl radicals. By using UV-Vis and excited fluorescence spectrum techniques, the main photooxidation products, which have higher absorption in the region of 240-340 nm, were found, and the mechanisms for the oxidative degradation is proposed.

Isolation and characterization of 18 polymorphic microsatellite markers in Chinese mandarin fish Siniperca chuatsi (Basilewsky)

Eighteen microsatellite markers were isolated and characterized using an enrichment protocol in the Chinese mandarin fish Siniperca chuatsi (Basilewsky), a commercially important piscivorous fish in China. Out of 48 pairs of primers designed, 18 loci exhibited polymorphism with three to six alleles (mean 4.4 alleles/locus) and average observed heterozygosity ranged from 0.633 to 0.833 (mean 0.748) in a test population from Dongting Lake of China. Except for two loci, all other 16 loci were in the Hardy-Weinberg equilibrium. These markers would be useful for such studies as population genetics, ecology and selective breeding of the Chinese mandarin fish in future.

Isolation and identification of a novel WSSV nucleocapsid protein by cDNA phage display using an scFv antibody

In a previous study, a scFv phage display library against white spot syndrome virus (WSSV) was constructed and yielded a clone designated A I with conformational specificity against native but not denatured viral antigen. Although the clone A1 has been used successfully as a diagnostic antibody, its precise target antigen has not been elucidated. A different strategy was adopted involving the construction of a second T7 phage display library utilizing mRNA isolated from shrimp infected with WSSV. Following RT-PCR and T7 phage library construction, phages displaying the candidate epitope were selected with A I scFv. Since successive enrichment steps were not associated with an increased titer of the phages, enrichment after successive tests was confirmed by PCR resulting in the prefer-red selection of a specific DNA sequence encoding a novel nucleocapsid protein WSSV388. Immune electron microscopy revealed that WSSV388 is located on the nucleocapsid. This result demonstrated that unknown antigen could be identified by phage display using the epitope conformation dependent scFv. (c) 2006 Elsevier B.V. All rights reserved.