Cloning, identification, and functional characterization of novel prophenoloxidases (ShproPO) from the freshwater crab Sinopotamon henanense in response to cadmium exposure and Aeromonas hydrophila infection.

Prophenoloxidase (proPO) is essential in the prophenoloxidase-activating system (proPO-AS) which is important for defense against foreign infection in crustaceans. However, most studies have focused on expression in the presence of a single pathogenic bacterium, and very few have addressed the presence of environmental contaminants simultaneously, such as cadmium (Cd) and Aeromonas hydrophila. Our study aimed to investigate the function of proPO in the freshwater crab Sinopotamon henanense and the changes in its expression by Cd and infection of A. hydrophila. A novel proPO from the hemocytes of S. henanense (ShproPO) was found in this research, the full-length cDNA of ShproPO was 2620 bp of encoding a protein of 678 amino acids containing three typical hemocyanin domains. The ShproPO protein could be found in both the granular (GHc) and the semi-granular hemocytes (SGHc). The ShproPO mRNA was found to be abundantly expressed in hemocytes and could be influenced by A. hydrophila infection. These results indicate that ShproPO could be involved in the antibacterial process. Further research found that low concentrations of Cd could promote its expression after infection with A. hydrophila. Therefore, it was hypothesized that Cd disrupted the response of crabs to A. hydrophila infection. Subsequently, PO enzyme activity was found to be significantly reduced through in vivo RNA interference with ShproPO, and the results suggested that ShproPO is likely to be a key enzyme in the melanization response. Finally, ShproPO was found to significantly enhance the phagocytosis of A. hydrophila-infected hemocytes by in vitro recombination, confirming that ShproPO is involved in hemocyte-mediated melanization and phagocytosis. Our findings reveal completely new insight into the immunotoxicity of Cd and the immune function of ShproPO in S. henanense.

Cadmium-induced ultrastructural changes and apoptosis in the gill of freshwater mussel Anodonta woodiana.

This study investigated the acute toxicity of cadmium (Cd) to the freshwater mussel Anodonta woodiana. The freshwater mussels were exposed to five concentrations of Cd (0 mg/L, 8.43 mg/L, 16.86 mg/L, 33.72 mg/L, and 67.45 mg/L) for up to 96 h. The 24-h, 48-h, 72-h, and 96-h LC50 values for Cd were estimated as 562.3 mg/L, 331.1 mg/L, 182.0 mg/L, and 134.9 mg/L, respectively. Caspase-3, caspase-8, caspase-9, and Ca-ATPase activities; protein and H2O2 levels; DNA fragmentation; and ultrastructure of the gill were also investigated. The activities of caspase-3 and caspase-9 in mussels were increased by Cd in a dose-dependent manner, where higher doses of Cd (33.72 mg/L and 67.45 mg/L) significantly increased the enzyme activities compared to the controls (P < 0.05). The caspase-8 activity was significantly depressed by a low dose of Cd (8.43 mg/L) but was clearly induced by higher doses of Cd (16.86 mg/L, 33.72 mg/L, and 67.45 mg/L) (P < 0.05). The Ca-ATPase activity and H2O2 levels were elevated and reached maximum values under the medium dose of Cd (16.86 mg/L). However, protein levels were decreased by Cd in an inverse dose-dependent manner. In the gills of the mussels, Cd treatment induced DNA fragmentation as demonstrated by DNA ladders observed via agarose gel electrophoresis. Moreover, ultrastructural alterations in gill cells of mussels treated with Cd (16.86 mg/L and 67.45 mg/L) for 96 h were observed by electronic microscopy. The ultrastructure abnormalities were characterized by the following features: (1) a disordered arrangement and breaking off of microvilli of epithelial cells; (2) chromatin condensed near the nuclear membrane and the appearances of extremely irregular nuclei, some with a fingerlike shape and an unclear, swollen, invaginated, or ruptured nuclear membrane and apoptotic bodies; (3) swollen and vacuolating mitochondria, some with disintegrated or missing cristae; (4) a disintegrated rough endoplasmic reticulum containing different sizes of vesicles; and (5) shrinking and deformation of Golgi bodies with decreased vesicle numbers. Our results demonstrated that Cd could activate caspase-3, caspase-8, caspase-9, and Ca-ATPase; cause ultrastructural changes; and produce DNA fragmentation in the mussels investigated. Based on the information obtained through this study, it is reasonable to conclude that Cd can induce apoptosis in the gills of the mussels, eventually leading to tissue damage.

A highly efficient uranium grabber derived from acrylic fiber for extracting uranium from seawater.

Acrylic fiber can be chemically converted to an amidoxime and carboxylate containing chelating adsorbent by a two-step synthesis method for extraction of uranium from seawater. A portion of the nitrile groups in the fiber is first converted to amidoxime using hydroxylamine followed by conversion of another portion of the nitrile groups to carboxylate with NaOH. At an optimized ratio of amidoxime/carboxylate (about 1 : 1), the chelating fiber in real seawater shows a higher uranium adsorption capacity and shorter saturation time compared with similar high-surface-area chelating fibers developed recently using a radiation-induced grafting method. The saturation capacity of uranium is estimated to be 7.73 grams per kilogram of the adsorbent at 20 °C and the half-saturation time is about 15.7 days. The fiber shows a vanadium/uranium ratio of about 1 in real seawater tests. The low vanadium adsorption capacity of the fiber is attributed to the branched-chain amidoxime groups formed by the specified amidoximation process. This simple and low-cost synthesis method can be scaled up to mass produce the chelating fiber for recovering metals from various aquatic environments including production of uranium from seawater.

Analysis of spectrometry and thermodynamics of the metallothionein in freshwater crab Sinopotamon henanense for its binding ability with different metals.

The metal binding nature of heterologously expressed metallothionein of Sinopotamon henanense (ShMT) had been demonstrated previously. In this study, we analysed the stoichiometry of ShMT yielded in vivo and exchange reactions of the Zn-ShMT with Cd2+, Pb2+ and Cu2+in vitro via electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), circular dichroism (CD) spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), and isothermal titration calorimetry (ITC). The results of ESI-TOF-MS analyses showed that metal-ShMT synthesized in vivo had three major forms, namely Zn15-, Cd9-, and Pb5-ShMT. The ITC analyses of exchange reactions demonstrated that Zn-ShMT exhibited up to 6, 6, and 7 binding sites for Cd2+, Pb2+ and Cu2+. By the analyses of the UV and CD spectra in the substitution experiments showed that the geometric structural stability of metal-ShMT could be influenced when excess of over 6, 6, or 7 equivalents of Cd2+, Pb2+, or Cu2+ were added into Zn-ShMT. Although both the reconstructed apo-ShMT and substituted Zn-ShMT with three metal ions fitted the same M6Ⅱ- and M7Ⅰ-ShMT binding models for divalent and monovalent metals, the differences in their thermodynamic data suggested that discrepancies exit in their physiological functions. These results suggested that ShMT yielded in vivo had a higher storage capability for Zn2+ and a uptake ability for Cd2+, and Zn-ShMT was more easy to release Zn2+ as well as to uptake Cd2+, Cu2+, or Pb2+. The results presented in this work will be very valuable to understand the function(s) of ShMT not only in a normal physiological condition but also in the presence of non-essential metals in crabs.

Total nasal reconstruction for nasal defect after treatment for extranodal natural killer/T cell lymphoma, nasal-type: A case report.

INTRODUCTION: Nasal-type extranodal natural killer (NK)/T-cell lymphomas are a rare type of clinical condition. Reconstruction of the complex nasal defect after chemoradiation is extremely challenging for plastic surgeons. PRESENTATION OF CASE: Here we present the case of a 56-year old female with the condition of a nasal-type NK/T-cell lymphoma which had caused complex nasal disfigurement. The patient had undergone chemoradiotherapy. Lesions after treatment were present all over the nasal defect (nasal septum, mucosa, support frame and skin) and the left cheek medial subunit. The surgery was subdivided into 3 stages. First, we removed the infectious tissue and restored the wall of nasal cavity by the left forehead - scalp flap. Second, we used the pedicle of the left forehead flap to rebuild the nasal mucosa defect, the rotational flap to rebuild the cheek defect, and the right forehead flap to recovered skin defect of the nose. Finally, we divided the pedicle of right forehead flap. DISCUSSION: The complex nasal defect is difficult to reconstruct and has a higher risk of failure in patient who received chemoradiotherapy. It is crucial to choose the right materials and have a confident plan in order to achieve successful results for the sake of the patient. CONCLUSION: Our case report shows that the nasal defect caused by a nasal-type NK/T-cell lymphoma is complex. After our 3 stages plan for the surgery, as well as using multiple flaps for reconstruction from the forehead skin, the result was significant reduction in the disfiguration of the patient's nose.

Visualization of endogenous hydrogen sulfide in living cells based on Au nanorods@silica enhanced fluorescence.

Hydrogen sulfide as a gas indicator molecule plays an important role in various human physiological processes. However, due to the high volatility and diffusivity of H2S in biological systems, it is very difficult to implement a precise assay for H2S detection. Compared with the destructive instrumental methods, assays based on fluorescence probes provide noninvasive and real-time detections of H2S in living cells. In this work, we presented a fluorescent nanoprobe based on dye-functionalized Au nanorods (NRs)@silica for sensitive and selective detection of H2S in vitro and living cells. With the metal enhanced fluorescence effect, the fluorescence turn-on and turn-off were controlled by the formation and disassembly of coordination compound between dyes and copper ions. Silica matrix was used to coat the Au NRs to prevent them from the biological cytotoxicity. The effects of the different distances between Au NRs and fluorophores on fluorescent enhancement were explored and approximately 5-fold fluorescence enhancement was obtained with a distance of 22 nm. A detection of limit of 17 nM was achieved. In addition, visualization of exogenous and endogenous H2S in living cells was validated.

Enhancing expression of the pseudorabies virus glycoprotein E in yeast and its application in an indirect sandwich ELISA.

AIMS: The purpose of this study was to produce a recombinant pseudorabies virus (PRV) glycoprotein E (gE) protein with the correct antigenicity for use as a low-cost diagnostic antigen. METHODS AND RESULTS: The gene fragment encoding the amino-terminal immunodominant region of PRV gE (codons 31-270) (gEN31-270) was codon optimized and expressed constitutively and secreted using a Pichia pastoris expression system. Yeast-expressed gEN31-270 (ygEN31-270) was harvested from the culture supernatant, and ygEN31-270 was shown to exhibit N-linked glycosylation. An indirect sandwich enzyme-linked immunosorbent assay (ELISA) was developed using ygEN31-270 as a coating antigen, and the results showed that the assay had high sensitivity and specificity, as well as almost perfect concordance with a commercial gE ELISA kit. CONCLUSIONS: The immunodominant region (amino acids 31-270) of gE was expressed successfully in P. pastoris using a codon optimization strategy. ygEN31-270 was secreted and N-glycosylated. The ygEN31-270-based indirect sandwich ELISA showed high sensitivity and specificity to detect gE-specific antibodies in swine serum samples. SIGNIFICANCE AND IMPACT OF THE STUDY: The ygEN31-270-based indirect sandwich ELISA may provide an alternative method for developing a diagnostic kit with easy manipulation and low cost.

Direct residue analysis of systemic insecticides and some of their relevant metabolites in wines by liquid chromatography - mass spectrometry.

A direct large volume injection (DI-LVI) high performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS) method was developed and validated for the quantitative determination of 16 systemic insecticides and their main plant metabolites. The assays were conducted on commercial red and white wines made from grapes grown in major wine-producing regions nationally and internationally. Using a 1:20 dilution and an injection volume of 800µL, a limit of quantitation (LOQ) of 1µgL-1 for all analytes was achieved. Matrix-matched standards (MM) were used for accurate quantitation. Imidacloprid (IMI) and methoxyfenozide (MET) were the most frequently detected parent insecticides in the wines reaching concentrations of 1-132µgL-1. Two important plant metabolites imidacloprid-olefin (IMI-OLE) and spirotetramat-enol (SPT-EN) were found at higher concentrations. In five samples SPT-EN was detected in the mgL-1 range with a maximum concentration of 16.3mgL-1 measured in a conventional white wine sample. Most "organic" wines contained no detectable or low insecticide residues, except for one sample, which showed the highest IMI (14.7µgL-1) and IMI-OLE (331µgL-1) concentrations. Considering the maximum residue limit (MRL) definition for the different insecticides, three "conventional" wine samples were non-compliant for SPT. This study highlights the importance to determine both parent and metabolite forms of systemic insecticides in the finished product.

Newly Designed Graphene Cellular Monolith Functionalized with Hollow Pt-M (M = Ni, Co) Nanoparticles as the Electrocatalyst for Oxygen Reduction Reaction.

Newly designed graphene cellular monoliths (GCMs) functionalized with hollow Pt-M nanoparticles (NPs) (Pt-M/GCM, M = Ni, Co) have been successfully achieved by a facile and powerful method on the basis of sonochemical-assisted reduction and gelatinization processes. First, hollow Pt-M (M = Ni, Co) NPs were synthesized and distributed on graphene oxide sheets (Pt-M/GO) by sodium borohydride reduction of metal precursors in the ultrasonic environment. Second, the hollow structure was further formed by ascorbic acid (AA) reduction of Pt precursors in gelatinization process. Meanwhile, GO sheets with hollow Pt-M NPs were reduced to graphene, and were assembled into Pt-M/GCM hydrogels by gelatinization process. The Pt-M/GCM (M = Ni, Co) electrocatalysts have a factor of 9.4-18.9 enhancement in electrocatalytic activity and higher durability toward oxygen reduction reaction (ORR), compared with those of commercial Pt/C catalyst. In detail, the mass activities for Pt-Ni/GCM and Pt-Co/GCM are 1.26 A mgPt-1 and 1.79 A mgPt-1, respectively; meanwhile, the corresponding specific activities are 1.03 and 2.08 mA cm-2. The successful synthesis of such attractive materials paves the way to explore a series of porous materials in widespread applications.

Two-Dimensional Nanoparticle Cluster Formation in Supercritical Fluid CO2.

Supercritical fluid carbon dioxide (sc-CO2) is capable of depositing nanoparticles in small structures of silicon substrates because of its gas-like penetration, liquid-like solvation abilities, and near-zero surface tension. In nanometer-sized shallow wells on silicon surface, formation of two-dimensional (2D) monolayer metal nanoparticle (NP) clusters can be achieved using the sc-CO2 deposition method. Nanoparticles tend to fill nanostructured holes first, and then, if sufficient nanoparticles are available, they will continue to cover the flat areas nearby, unless defects or other surface imperfections are available. In addition, SEM images of two-dimensional gold (Au) nanoparticle clusters formed on a flat silicon surface with two to a dozen or more of the nanoparticles are provided to illustrate the patterns of nanoparticle cluster formation in sc-CO2.

Ultrasonic-assisted synthesis of Pd-Pt/carbon nanotubes nanocomposites for enhanced electro-oxidation of ethanol and methanol in alkaline medium.

Herein, a facile ultrasonic-assisted strategy was proposed to fabricate the Pd-Pt alloy/multi-walled carbon nanotubes (Pd-Pt/CNTs) nanocomposites. A good number of Pd-Pt alloy nanoparticles with an average of 3.4 ± 0.5 nm were supported on sidewalls of CNTs with uniform distribution. The composition of the Pd-Pt/CNTs nanocomposites could also be easily controlled, which provided a possible approach for the preparation of other architectures with anticipated properties. The Pd-Pt/CNTs nanocomposites were extensively studied by electron microscopy, induced coupled plasma atomic emission spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, and applied for the ethanol and methanol electro-oxidation reaction in alkaline medium. The electrochemical results indicated that the nanocomposites had better electrocatalytic activities and stabilities, showing promising applications for fuel cells.

Impact of lower concentrations of phytoestrogens on the effects of estradiol in breast cancer cells.

OBJECTIVE: To explore the impact of lower concentrations of phytoestrogens on 17ß-estradiol (E2) in the growth of MCF-7 breast cells. METHODS: MCF-7 cells were treated with E2 (10(-8) mol/l), one of three phytoestrogens (genistein, resveratrol, and quercetin) (10(-7)  to 10(-5) mol/l), and with a combination of both E2 and one of these phytoestrogens for 48 h. These cells were then extracted for MTT and TUNEL assay. Western blot was utilized to evaluate the proteins involved in the proliferative and apoptotic pathways, as well as the differential effects on ERα and ß. RESULTS: MCF-7 cell proliferations were induced by both E2 alone and E2 plus one of the three phytoestrogens (at concentrations ≥ 10(-6) mol/l). Apoptotic cells were significantly increased in the phytoestrogen-treated MCF-7 cells and, conversely, suppressed in the cells treated with both E2 and phytoestrogens. Proliferating cell nuclear antigen, PI3K and p-Akt were increased in the cultures with E2 and substantially more in the cultures with E2 plus a phytoestrogen. The combination of E2 and phytoestrogen significantly inhibited the increase in FADD, cytochrome C, truncated Bid, caspase-9, caspase-3 and ERß that was induced by phytoestrogens in the MCF-7. ERα expression was significantly induced by E2 regardless of the presence of these phytoestrogens. CONCLUSIONS: This study demonstrates that, in the presence of E2, genistein, resveratrol, and quercetin may stimulate breast cancer cells, even at low physiological concentrations. Therefore, the conflicting results regarding the effects of phytoestrogens on breast cells may be attributed to the endogenous estrogen present in breast tissue.

RAGE gene polymorphism and environmental factor in the risk of oral cancer.

Oral squamous cell carcinoma is a common neoplasm that is known to be causally associated with genetic factors and environmental carcinogens. The receptor for advanced glycosylation endproducts (RAGE) is a transmembrane protein of the immunoglobulin superfamily with broad specificity for multiple ligands, and it has been shown to play vital roles in several pathophysiologic processes, including diabetes, Alzheimer disease, renal disease, cardiovascular disease, and cancer. The present study aimed to assess the influences of RAGE gene polymorphisms, combined with environmental carcinogens on the predisposition to oral tumorigenesis. Five polymorphisms of the RAGE gene-including -374T>A (rs1800624), -429T>C (rs1800625), 1704G>T (rs184003), Gly82Ser (rs2070600), and a 63-bp deletion allele (-407 to -345)-were examined from 592 controls and 618 patients with oral cancer. We found that individuals carrying the polymorphic allele of rs1800625 are more susceptible to oral cancer (odds ratio [OR], 1.899; 95% confidence interval [CI], 1.355 to 2.661; adjusted OR [AOR], 2.053; 95% CI, 1.269 to 3.345) after adjustment for age, sex, betel nut chewing, and tobacco consumption. Moreover, we observed a significant association of rs1800625 variants with late-stage tumors (stage III/IV, OR, 1.736; 95% CI, 1.126 to 2.677; AOR, 1.771; 95% CI, 1.101 to 2.851) and large-size tumors (>2 cm in the greatest dimension; OR, 1.644; 95% CI, 1.083 to 2.493; AOR, 1.728; 95% CI, 1.089 to 2.741). Based on behavioral exposure of environmental carcinogens, the presence of 4 RAGE single-nucleotide polymorphisms (SNPs), combined with betel quid chewing and/or tobacco use, greatly augmented the risk of oral cancer. In addition, carriers of particular haplotypes of the 4 RAGE SNPs examined are more prone to develop oral cancer. These results indicate an involvement of RAGE SNP rs1800625 in the development of oral squamous cell carcinoma and implicate the interaction between RAGE gene polymorphisms and environmental mutagens as a predisposing factor of oral carcinogenesis.

Phytoestrogens induce differential effects on both normal and malignant human breast cells in vitro.

OBJECTIVE: To explore the effect and pathway of phytoestrogens in vitro on the growth of both normal and malignant breast cells. METHODS: Normal breast MCF-10A cells and breast cancer MCF-7 cells were incubated with 10 (-10)-10(-4)  mol/l genistein, resveratrol, and quercetin (plasma concentrations in human: 10 nmol/l-10 µmol/l) for 48 h and were then extracted for a cell proliferation assay (MTT), and for a cell death assay (TUNEL) assay. The proteins involved in the proliferative and apoptotic pathways were evaluated by Western blot analysis. Additionally, a comparison with 17ß-estradiol as well as an evaluation of the differential effects on estrogen receptors (ER) α and ß were performed. RESULTS: MCF-7 cell proliferation was significantly inhibited at the concentrations greater than 10(-4) mol/l for all three phytoestrogens and from 10 (-5) mol/l for resveratrol and quercetin. MCF-10A cell proliferation was significantly increased at the concentrations from 10 (-8) to 10 (-5) mol/l for genistein and resveratrol and only at 10 (-5) mol/l for quercetin. Apoptotic cells were significantly increased by these phytoestrogens in the MCF-7 cells. At a concentration of 10 (-7)  mol/l of these phytoestrogens, a significant reduction of PI3K and Akt and an increase of Fas ligand, Fas-associated protein with death domain, cytochrome C, truncated Bid, caspase-9, and caspase-3 were noted in the MCF-7; PI3K and Akt were significantly increased in the MCF-10A. ERß expression was significantly elevated in MCF-10A and MCF-7 with these phytoestrogens. The effects of estradiol on normal and malignant breast cells were completely opposite to those of phytoestrogens. CONCLUSIONS: This study demonstrates that phytoestrogens have antiproliferative effects on breast cancer cells via an ER-dependent mechanism, even at low concentrations, but are also capable of maintaining the survival of normal breast cell via ER-independent or other mechanisms.

Development of dynamic models of the Mauch prosthetic knee for prospective gait simulation.

Recent advances in computational modeling and simulation of human movement makes it possible to isolate and predict the potential contributions of a prosthetic device to the overall system performance. The Mauch S-N-S knee is one of the most widely used prosthetic knees in the market. The goal of this study is to develop dynamic models of the Mauch S-N-S knee for predictive simulation of a transfemoral amputee's gait under idealized conditions. Based on the functional description of the Mauch S-N-S prosthetic knee from the literature, a combined bench test and data fitting approach employing modified slow, normal, and fast gait patterns and nine combinations of stance and swing damping settings were performed. Two types of dynamic models, 2-phase and 4-phase models, of the Mauch S-N-S prosthetic knee were developed. The range of the coefficient of determination of the two dynamic models, when compared to the test data, was from 39.9 to 95%. Both dynamic models of this study can be utilized in musculoskeletal modeling studies, to better understand amputee gait and the contributions and interactions of various prosthetic leg components to the ambulatory performance.

Supercritical fluid extraction and separation of uranium from other actinides.

The feasibility of separating U from nitric acid solutions of mixed actinides using tri-n-butylphosphate (TBP)-modified supercritical fluid carbon dioxide (sc-CO2) was investigated. The actinides U, Np, Pu, and Am were extracted into sc-CO2 modified with TBP from a range of nitric acid concentrations, in the absence of, or in the presence of, a number of traditional reducing and/or complexing agents to demonstrate the separation of these metals from U under sc-CO2 conditions. The separation of U from Pu using sc-CO2 was successful at nitric acid concentrations of less than 3M in the presence of acetohydroxamic acid (AHA) or oxalic acid (OA) to mitigate Pu extraction, and the separation of U from Np was successful at nitric acid concentrations of less than 1M in the presence of AHA, OA, or sodium nitrite to mitigate Np extraction. Americium was not well extracted under any condition studied.

Carbonate-H2O2 leaching for sequestering uranium from seawater.

Uranium adsorbed on amidoxime-based polyethylene fiber in simulated seawater can be quantitatively eluted at room temperature using 1 M Na2CO3 containing 0.1 M H2O2. This efficient elution process is probably due to the formation of an extremely stable uranyl-peroxo-carbonato complex in the carbonate solution. After washing with water, the sorbent can be reused with minimal loss of uranium loading capacity. Possible existence of this stable uranyl species in ocean water is also discussed.

Lower concentrations of phthalates induce proliferation in human breast cancer cells.

OBJECTIVE: To explore the effect and pathway of phthalates on the growth of MCF-7 breast cancer cells. METHODS: MCF-7 cells were treated with benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), and di-2-ethylhexyl phthalate (DEHP) (10(-10)-10(-4) mol/l). After incubation for 24, 48, 72, and 92 h, the cells were harvested and extracted for 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The proteins involving proliferative and apoptotic pathways were evaluated by Western blot analysis. RESULTS: MTT assay revealed cell toxicity at more than 10(-5) mol/l for DEHP and at 10(-4) mol/l for both BBP and DBP in MCF-7 cells. Cell proliferation was significantly increased at 10(-8)-10(-5) mol/l of BBP and DBP, and at 10(-8)-10(-6) mol/l of DEHP treatment. Proliferating cell nuclear antigen (PCNA) was substantially increased in cultures with DEHP (10(-8)-10(-6) mol/l), BBP (10(-8)-10(-5) mol/l), and DBP (10(-7)-10(-5) mol/l). Obvious increases in PI3K, p-AKT, and PCNA were noted in cultures with 17ß-estradiol, BBP, DBP, and DEHP. Estrogen receptor α expression was also notably increased in treatment with estradiol, BBP, DBP, and DEHP. CONCLUSIONS: The present study demonstrates that, even at a very low concentration, BBP, DBP, and DEHP were not only still capable of inducing a proliferative effect through the PI3K/AKT signaling pathway but also displaying estrogenic activity. Therefore, the current reference doses for phthalates defined by governments should be further evaluated.

Ultrasound-assisted synthesis of PbS quantum dots stabilized by 1,2-benzenedimethanethiol and attachment to single-walled carbon nanotubes.

Lead sulfide (PbS) quantum dots stabilized by 1,2-benzenedimethanethiol can be synthesized by mixing Pb(NO3)2 and Na2S solutions in ethanol under ultrasound irradiation. The PbS quantum dots (2.7 and 3.6 nm in diameter) are characterized by their absorption and fluorescence spectra in the near infrared region and by other surface analytical techniques. With addition of single-walled carbon nanotubes (SWNT) to the system, this ultrasound-assisted procedure allows attachment of PbS nanoparticles to SWNT surface via π-π stacking, thus providing a simple one-pot method for preparation of SWNT-PbS nanoparticle composite materials. Using the ultrasound-assisted method for synthesizing silica composites containing PbS nanoparticles by a sol-gel process is also described.

Phytoestrogens induce apoptosis through a mitochondria/caspase pathway in human breast cancer cells.

OBJECTIVE: To explore the effect and pathway of phytoestrogens on the growth of breast cancer cell line MCF-7. METHODS: MCF-7 cells (human estrogen receptor-positive and progesterone receptor-positive breast cancer cells) were cultured in serum-free medium for 24 h and then treated with genistein, resveratrol, and quercetin (10(-10)-10(-4) mol/l). After further incubation for 24, 48, 72, and 92 h, the cells were harvested and extracted for 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. According to the above results, the proteins involving proliferative and apoptotic pathways were evaluated by Western blot analysis. RESULTS: Genistein, resveratrol, and quercetin significantly inhibited cellular proliferation in a dose- and time-dependent manner. Significantly elevated caspase-3 activity was noted after treatment with genistein (10(-9)-10(-7) mol/l), as well as with resveratrol and quercetin (10(-9)-10(-5) mol/l). Significant reduction of PI3K and AKT protein and significant increase of Fas ligand, Fas-associated protein with death domain, cytochrome C, truncated Bid, caspase-9, and caspase-3 were all noted after genistein, resveratrol, and quercetin treatment. 17ß-Estradiol induced completely opposite results. Estrogen receptor (ER) α expression was significantly increased with 17ß-estradiol, whereas ERß expression was significantly elevated in the cultures with genistein, resveratrol, and quercetin. CONCLUSIONS: These data demonstrate that genistein, resveratrol, and quercetin have antiproliferative effects on breast cancer cells. Their induction of apoptosis involves the activation of both the intrinsic and extrinsic apoptotic pathways, which may be related to the differential affinity to ERα and ERß. Whether phytoestrogens have similar effects on normal breast cells remains to be examined.