[Synthetic phenolic compounds perturb lipid metabolism and induce obesogenic effects].

Given continuous development in society and the economy, obesity has become a global epidemic, arousing great concern. In addition to genetic and dietary factors, exposure to environmental chemicals is associated with the occurrence and development of obesity. Current research has indicated that some chemicals with endocrine-disrupting effects can affect lipid metabolism in vivo, causing elevated lipid storage. These chemicals are called "environmental obesogens". Synthetic phenolic compounds (SPCs) are widely used in industrial and daily products, such as plastic products, disinfectants, pesticides, food additives, and so on. The exposure routes of SPCs to the human body may include food and water consumption, direct skin contact, etc. Their unintended exposure could cause harmful effects on human health. As a type of endocrine disruptor, SPCs interfere with adipogenesis and lipid metabolism, exhibiting the characteristics of environmental obesogens. Because SPCs have similar phenolic structures, gathering information on their influences on lipid metabolism would be helpful to understand their structure-related effects. In this review, three commonly used research methods for screening environmental obesogens, including in vitro testing for molecular interactions, cell adipogenic differentiation models, and in vivo studies on lipid metabolism, are summarized, and the advantages and disadvantages of these methods are compared and discussed. Based on both in vitro and in vivo data, three types of SPCs, including bisphenol A (BPA) and its analogues, alkylphenols (APs), and synthetic phenolic antioxidants (SPAs), are systematically discussed in terms of their ability to disrupt adipogenesis and lipid metabolism by focusing on adipose and hepatic tissues, among others. Common findings on the effects of these SPCs on adipocyte differentiation, lipid storage, hepatic lipid accumulation, and liver steatosis are described. The underlying toxicological mechanisms are also discussed from the aspects of nuclear receptor transactivation, inflammation and oxidative stress regulation, intestinal microenvironment alteration, epigenetic modification, and some other signaling pathways. Future research to increase public knowledge on the obesogenic effects of emerging chemicals of concern is encouraged.

Effectiveness of lenvatinib plus immune checkpoint inhibitors in primary advanced hepatocellular carcinoma beyond oligometastasis.

BACKGROUND: Targeted therapy combined with immune checkpoint inhibitors is considered a promising treatment for primary advanced hepatocellular carcinoma (HCC). Nevertheless, the difference between synchronous and asynchronous treatment of lenvatinib with programmed death receptor-1 (PD-1) inhibitor in advanced HCC is still unclear. The aim of this investigation is to evaluate the effectiveness of synchronous and asynchronous of lenvatinib and PD-1 inhibitor on the advanced HCC beyond oligometastasis. METHODS: In this study, 213 patients from four institutions in China were involved. Patients were split into two collections: (1) lenvatinib plus PD-1 inhibitor were used synchronously (synchronous treatment group); (2) patients in asynchronous treatment group received PD-1 inhibitor after 3 months of lenvatinib treatment prior to tumour progression. To analyse progression-free survival (PFS), overall survival (OS), efficacy and safety of patients in both groups, we employed propensity score matching (PSM). RESULTS: The 6-, 12- and 24-month OS rates were 100%, 93.4% and 58.1% in the synchronous treatment group and 100%, 71.5% and 25.3% in the asynchronous treatment group, respectively. In contrast to the asynchronous treatment group, the group treated synchronously exhibited a substantially enhanced OS (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.30-0.66; p < .001). The 6-, 12- and 18-month PFS rates were 82.6%, 42.6% and 10.8% in the synchronous treatment group and 63.3%, 14.2% and 0% in the asynchronous treatment group, respectively. A significant difference was observed in the PFS rate (HR, 0.46; 95% CI, 0.33-0.63; p < .001) between the two collections. CONCLUSIONS: Patients with advanced HCC beyond oligometastasis, simultaneous administration of lenvatinib and PD-1 inhibitor led to significant improvements in survival.

Efficacy of radiofrequency ablation following transarterial chemoembolisation combined with sorafenib for intermediate stage recurrent hepatocellular carcinoma: a retrospective, multicentre, cohort study.

Background: The evidence of radiofrequency ablation (RFA) following transarterial chemoembolisation (TACE) combined with sorafenib for intermediate-stage recurrent hepatocellular carcinoma (RHCC) is limited. Patient responses to this treatment vary because of the heterogeneous nature of RHCC, making it important to identify patients who are most likely to benefit from this combination therapy. The aim of this study was to evaluate the efficacy of RFA following TACE and sorafenib for the intermediate-stage RHCC. Methods: This retrospective, multicentre, cohort study included 363 patients with intermediate-stage RHCC underwent TACE combined with sorafenib (TACE-sorafenib group) or RFA following TACE and sorafenib (TACE-sorafenib + RFA group) between January 01, 2009 to December 31, 2015 from four institutions in China. Overall survival (OS), progression-free survival (PFS) and efficacy of patients were compared between the two groups by propensity score-matching (PSM). Findings: The 1-, 3-, and 5-year OS rates were 97.7%, 83.7%, 54.7% in TACE-sorafenib + RFA group, and 93.3%, 57.0%, 32.7% in TACE-sorafenib group. The 1-, 2-, and 3-year PFS rates were 85.3%, 58.0%, 26.9% in TACE-sorafenib + RFA group, and 55.3%, 30.7%, 15.3% in TACE-sorafenib group. Compared with the TACE-sorafenib group, the TACE-sorafenib + RFA group had significantly longer OS (HR, 0.54; 95%CI, 0.40-0.73; P < 0.001) and PFS (HR, 0.52; 95% CI, 0.41-0.66; P < 0.001). Subgroup analysis was conducted to precisely screen out the beneficial population from RFA treatment. Interpretation: Our findings suggest that addition of RFA following TACE and sorafenib combination was superior to TACE combined with sorafenib for intermediate-stage RHCC, resulting in longer OS and PFS. Patients who had good response to TACE and achieved downstaging successfully could not benefit from the RFA therapy. Funding: This research was funded by National Natural Science Foundation of China (No. 81627803), Chen Xiao-Ping Science and Technology Development Fund (CXPJJH1200009-06).

Tenofovir vs. entecavir on prognosis of hepatitis B virus-related hepatocellular carcinoma after curative resection.

BACKGROUND: Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are recommended as first-line choices regarding the treatment of chronic hepatits B. The impact of the two antiviral agents on prognosis of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) after curative liver resection remains to be explored. We aimed to assess the effect of antiviral therapy with ETV or TDF after curative resection on the prognosis of patients with HBV-related HCC. METHODS: A total of 1173 consecutive patients who were treated with ETV or TDF after curative liver resection for HCC were enrolled in the study. HCC recurrence, overall survival, postoperative liver function reserve, and early virologic (VR) and biochemical responses (BR) of patients were compared between the ETV and TDF groups by propensity score matching (PSM) from the date of liver resection for HCC. RESULTS: No difference was observed with recurrence-free survival between TDF and ETV in the PSM cohort (hazard ratio [HR], 0.91; 95% confidence interval [CI] 0.70-1.17; P = 0.45). No difference was observed with early VR and BR between TDF and ETV in the PSM cohort. Compared with ETV, TDF therapy was associated with significantly better protection of liver function and higher overall survival rates in the PSM cohort (HR, 0.37; 95% CI 0.20-0.71; P = 0.002). After PSM, 69 (40.8%) patients in the ETV group and 63 (57.3%) patients in the TDF group had single tumor recurrence, while the TDF group had significantly more patients with single tumor recurrence in the PSM cohort (P = 0.007). CONCLUSIONS: For patients who underwent curative resection for HBV-related HCC, TDF treatment had a significantly better overall survival and better protection of liver function, but no difference in the incidences of HCC recurrence than ETV treatment.

Development and validation of prognostic nomograms for single large and huge hepatocellular carcinoma after curative resection.

AIM: The prediction model of postoperative survival for single large and huge hepatocellular carcinoma (SLH-HCC, diameter > 5.0 cm) without portal vein tumour thrombus has not been well established. This study aimed to develop novel nomograms to predict postoperative recurrence and survival of these patients. METHODS: Data from 2469 patients with SLH-HCC who underwent curative resection from January 2005 to December 2015 in China were retrospectively collected. Specifically, nomograms of recurrence-free survival (RFS) and overall survival (OS) using data from a training cohort were developed with the Cox regression model (n = 1012). The modes were verified in an internal validation cohort (n = 338) and an external cohort comprising four tertiary institutions (n = 1119). RESULTS: The nomograms of RFS and OS based on tumour clinicopathologic features (diameter, differentiation, microvascular invasion, α-fetoprotein), operative factors (preoperative transcatheter arterial chemoembolisation therapy, scope of liver resection and intraoperative blood transfusion), underlying liver function (albumin-bilirubin grade) and systemic inflammatory or immune status (neutrophil-to-lymphocyte ratio) achieved high C-indexes of 0.85 (95% confidence interval [CI], 0.79-0.91) and 0.86 (95% CI, 0.79-0.93) in the training cohort, respectively, which were significantly higher than those of the five conventional HCC staging systems (0.62-0.73 for RFS, 0.63-0.75 for OS). The nomograms were validated in the internal cohort (0.83 for RFS, 0.84 for OS) and external cohort (0.87 for RFS, 0.88 for OS) and had well-fitted calibration curves. Our nomograms accurately stratified patients with SLH-HCC into low-, intermediate- and high-risk groups of postsurgical recurrence and mortality. CONCLUSIONS: The two nomograms achieved optimal prediction for postsurgical recurrence and OS for patients with SLH-HCC after curative resection.

Multi-institutional validation of novel models for predicting the prognosis of patients with huge hepatocellular carcinoma.

The population of patients with huge hepatocellular carcinoma (H-HCC diameter > 10.0 cm) is an odd group that is not well adjudicated in the current staging systems, whose prognosis after curative resection varies. We aimed to develop novel models to predict the long-term outcomes of patients with H-HCC without portal vein tumor thrombus after hepatectomy. There were 1076 H-HCC patients enrolled who underwent curative liver resection in five institutions in China. In total, 670 patients were recruited from our center and randomly divided into the training cohort (n = 502) and internal validation (n = 168) cohorts. Additionally, 406 patients selected from other four centers as the external validation cohort. Novel models were constructed based on independent preoperative and postoperative predictors of postsurgical recurrence (PSR) and postsurgical mortality (PSM) determined in multivariable cox regression analysis. The predictive accuracy and discriminative ability of the model were measured using Harrell's concordance index (C index) and calibration curve and compared with five conventional HCC staging systems. PSR model and PSM model were constructed based on tumor number, microscopic vascular invasion, tumor differentiation, preoperative alpha-fetoprotein level, albumin-bilirubin grade, liver segment invasion, neutrophil-to-lymphocyte ratio or platelet-to-neutrophil ratio, and surgical margin or intraoperative blood transfusion. The C-indexes were 0.84 (95% CI, 0.78-0.90) and 0.85 (95% CI, 0.78-0.91) for the PSR and PSM models, respectively, which were substantially higher than those of the five conventional HCC staging systems (0.63-0.75 for PSR; 0.66-0.77 for PSM). The two novel models achieved more accurate prognostic predictions of PSR and PSM for H-HCC patients after curative liver resection.

Hepatic Microwave Ablation-Induced Tumor Destruction and Animal End Point Survival Can Be Improved by Suppression of Heat Shock Protein 90.

OBJECTIVES: To investigate the effect of heat shock protein 90 (HSP90) modulation on tumor necrosis, apoptosis, tumor growth delay, and end point survival by combining microwave ablation (MWA) with an HSP90 inhibitor in a nude mouse model. METHODS: This study was approved by the Ethics Committee. Forty mice with HepG2 subcutaneous xenograft tumors (10 ± 1 mm) were randomized into 4 groups: (1) no treatment, (2) MWA only, (3) the HSP90 inhibitor ganetespib only, and (4) ganetespib combined with MWA. Tumors were harvested 24 hours after treatment, and gross coagulation diameters were measured. The effect of ganetespib on HSP90 and caspase 3 expression in the periablational rim was assessed. Another 40 mice with the same tumors and groupings were observed after treatment. Tumor growth curve and Kaplan-Meier survival analyses were performed with a tumor diameter of 2.2 cm and 40 days of survival as the defined survival end points. RESULTS: Combination treatment significantly increased the coagulation size compared to tumors treated with MWA or ganetespib alone (P < 0.05). The combination of MWA and ganetespib decreased HSP90 expression and increased cleaved caspase 3 expression 24 hours after treatment. Compared with MWA or ganetespib only, combination treatment could lengthen the end point survival and reduce the tumor growth rate. CONCLUSIONS: Modulation of HSP production can improve MWA-induced tumor apoptosis and destruction, reduce residual tumor growth rates, and prolong end point survival.

PM2.5 induces vascular permeability increase through activating MAPK/ERK signaling pathway and ROS generation.

Although in-vivo exposure of PM2.5 has been suggested to initiate a disorder on vascular permeability, the effects and related mechanism has not been well defined. In this work, an obvious increase on vascular permeability has been confirmed in vivo by vein injection of PM2.5 into Balb/c mouse. Human umbilical vein vascular endothelial cells and the consisted ex-vivo vascular endothelium were used as model to investigate the effects of PM2.5 on the vascular permeability and the underlying molecular mechanism. Upon PM2.5 exposure, the vascular endothelial growth factor receptor 2 on cell membrane phosphorylates and activates the downstream mitogen-activated protein kinase (MAPK)/ERK signaling. The adherens junction protein VE-cadherin sheds and the intercellular junction opens, damaging the integrity of vascular endothelium via paracellular pathway. Besides, PM2.5 induces the intracellular reactive oxygen species (ROS) production and triggers the oxidative stress including activity decrease of superoxide dismutase, lactate dehydrogenase release and permeability increase of cell membrane. Taken together, the paracellular and transcellular permeability enhancement jointly contributes to the significant increase of endothelium permeability and thus vascular permeability upon PM2.5 exposure. This work provides an insight into molecular mechanism of PM2.5 associated cardiovascular disease and offered a real-time screening method for the health risk of PM2.5.

Advances in Nanostructure-mediated Hyperthermia in Tumor Therapies.

BACKGROUND: Hyperthermia has been proposed as a promising treatment modality for its advantageous profiles such as mini/non-invasiveness, good tolerability and cost-effectiveness. Quick development of nanotechnology in recent years has greatly broadened the application area of hyperthermia and endowed it with attractive new functions. This review aims to present an overview of different nanostructures mediated hyperthermia in terms of external stimuli source. METHODS: We performed to review for the development and current status of nanostructure-mediated hyperthermia, by searching MEDLINE, EMBASE, and Cochrane Library database for identification of relevant articles. RESULTS: In the present study, the systemic results of hyperthermia mediated by nanostructures were researched, and five different kinds of external sources were found and listed in this review. The brief mechanism and commonly explored nanostructures were introduced and then combined therapies of nanostructure-mediated hyperthermia stimulated by different external sources were investigated. Finally, challenges with current nanostructures mediated hyperthermia were discussed in order to give advice to the future development of nanostructure-mediated hyperthermia. CONCLUSIONS: Despite all the achievements the new technology of nanostructure-mediated hyperthermia have made in pre-clinical animal experiments, there are still much to be pursued in the further development to be biocompatible, effective and precise.

Surface ligand controls silver ion release of nanosilver and its antibacterial activity against Escherichia coli.

Understanding the mechanism of nanosilver-dependent antibacterial activity against microorganisms helps optimize the design and usage of the related nanomaterials. In this study, we prepared four kinds of 10 nm-sized silver nanoparticles (AgNPs) with dictated surface chemistry by capping different ligands, including citrate, mercaptopropionic acid, mercaptohexanoic acid, and mercaptopropionic sulfonic acid. Their surface-dependent chemistry and antibacterial activities were investigated. Owing to the weak bond to surface Ag, short carbon chain, and low silver ion attraction, citrate-coated AgNPs caused the highest silver ion release and the strongest antibacterial activity against Escherichia coli, when compared to the other tested AgNPs. The study on the underlying antibacterial mechanisms indicated that cellular membrane uptake of Ag, NAD+/NADH ratio increase, and intracellular reactive oxygen species (ROS) generation were significantly induced in both AgNP and silver ion exposure groups. The released silver ions from AgNPs inside cells through a Trojan-horse-type mechanism were suggested to interact with respiratory chain proteins on the membrane, interrupt intracellular O2 reduction, and induce ROS production. The further oxidative damages of lipid peroxidation and membrane breakdown caused the lethal effect on E. coli. Altogether, this study demonstrated that AgNPs exerted antibacterial activity through the release of silver ions and the subsequent induction of intracellular ROS generation by interacting with the cell membrane. The findings are helpful in guiding the controllable synthesis through the regulation of surface coating for medical care purpose.

Negatively charged silver nanoparticles cause retinal vascular permeability by activating plasma contact system and disrupting adherens junction.

Silver nanoparticles (AgNPs) have been extensively used as antibacterial component in numerous healthcare, biomedical and consumer products. Therefore, their adverse effects to biological systems have become a major concern. AgNPs have been shown to be absorbed into circulation and redistributed into various organs. It is thus of great importance to understand how these nanoparticles affect vascular permeability and uncover the underlying molecular mechanisms. A negatively charged mecaptoundeonic acid-capped silver nanoparticle (MUA@AgNP) was investigated in this work. Ex vivo experiments in mouse plasma revealed that MUA@AgNPs caused plasma prekallikrein cleavage, while positively charged or neutral AgNPs, as well as Ag ions had no effect. In vitro tests revealed that MUA@AgNPs activated the plasma kallikrein-kinin system (KKS) by triggering Hageman factor autoactivation. By using specific inhibitors aprotinin and HOE 140, we demonstrated that KKS activation caused the release of bradykinin, which activated B2 receptors and induced the shedding of adherens junction protein, VE-cadherin. These biological perturbations eventually resulted in endothelial paracellular permeability in mouse retina after intravitreal injection of MUA@AgNPs. The findings from this work provided key insights for toxicity modulation and biomedical applications of AgNPs.

Real-time 3-dimensional contrast-enhanced ultrasound in detecting hemorrhage of blunt renal trauma.

OBJECTIVES: The objective of this study is to evaluate the diagnostic value of real-time 3-dimensional contrast-enhanced ultrasound in the hemorrhage of blunt renal trauma. METHODS: Eighteen healthy New Zealand white rabbits were randomly divided into 3 groups. Blunt renal trauma was performed on each group by using minitype striker. Ultrasonography, color Doppler flow imaging, and contrast-enhanced 2-dimensional and real-time 3-dimensional ultrasound were applied before and after the strike. The time to shock and blood pressure were subjected to statistical analysis. Then, a comparative study of ultrasound and pathology was carried out. RESULTS: All the struck kidneys were traumatic. In the ultrasonography, free fluid was found under the renal capsule. In the color Doppler flow imaging, active hemorrhage was not identified. In 2-dimensional contrast-enhanced ultrasound, active hemorrhage of the damaged kidney was characterized. Real-time 3-dimensional contrast-enhanced ultrasound showed a real-time and stereoscopic ongoing bleeding of the injured kidney. The wider the hemorrhage area in 4-dimensional contrast-enhanced ultrasound was, the faster the blood pressure decreased. CONCLUSIONS: Real-time 3-dimensional contrast-enhanced ultrasound is a promising noninvasive tool for stereoscopically and vividly detecting ongoing hemorrhage of blunt renal trauma in real time.

Investigations on boron levels in drinking water sources in China.

To evaluate boron contamination of public drinking water in China, both dissolved and total boron contents in 98 public drinking water sources from 49 cities, 42 brands of bottled water samples from supermarkets in several cities, and 58 water samples from boron industrial area were measured by inductively coupled plasma-mass spectrometry (ICP-MS). Our experimental results showed that boron existed in public drinking water sources mainly in dissolved status with total concentrations ranging from 0.003 to 0.337 mg/L (mean = 0.046 mg/L). The mean boron concentrations in mineral and pure bottled water were 0.052 and 0.028 mg/L, respectively. The results obtained in this work showed that there was no health risk on view of boron in public drinking water sources and bottled water. In boron industrial area, boron concentrations in surface water and ground water were 1.28 mg/L (range = 0.007-3.8 mg/L) and 18.3 mg/L (range = 0.015-140 mg/L), respectively, which indicated that boron industry caused boron pollution in local water system.

Excretion of PFOA and PFOS in male rats during a subchronic exposure.

Perfluorinated compounds (PFCs), a class of synthetic surfactants that are widely used, have become global environmental contaminants because of their high persistence and bioaccumulation. An increasing number of studies have described the pharmacokinetics of PFCs following in vivo exposure, however, few papers have focused on the excretion of these compounds during a period of consecutive exposure. In this study, the excretions of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in male Sprague-Dawley rats gavaged consecutively for 28 days were investigated and compared. The faster elimination rate in urine compared to feces indicated that urinary excretion is the primary clearance route in rats for either PFOA or PFOS. During the first 24 h after administration of PFOA (5 and 20 mg/kg body weight/day), about 24.7-29.6% of the oral dose was excreted through urine and feces, while for PFOS, the excretion amounts were only 2.6-2.8% of the total gavaged doses (5 and 20 mg/kg body weight/day). The excretion rates of both PFCs increased with increasing exposure doses. The higher elimination rate of PFOA through excretion indicated its lower accumulation in rats, thus inducing possible lower toxicities compared to PFOS.

Studies on the toxicological effects of PFOA and PFOS on rats using histological observation and chemical analysis.

As an emerging class of environmentally persistent and bioaccumulative contaminants, perfluorinated compounds (PFCs), especially perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), have been ubiquitously found in the environment. Increasing evidence shows that the accumulated levels of PFCs in animals and the human body might cause potential impairment to their health. In the present study, toxicological effects of PFOA and PFOS on male Sprague-Dawley rats were examined after 28 days of subchronic exposure. Abnormal behavior and sharp weight loss were observed in the high-dose PFOS group. Marked hepatomegaly, renal hypertrophy, and orchioncus in treated groups were in accordance with the viscera-somatic indexes of the liver, kidney, and gonad. Histopathological observation showed that relatively serious damage occurred in the liver and lung, mainly including hepatocytic hypertrophy and cytoplasmic vacuolation in the livers and congestion and thickened epithelial walls in the lungs. PFOA concentrations in main target organs were in the order of kidney > liver > lung > (heart, whole blood) > testicle > (spleen, brain), whereas the bioaccumulation order for PFOS was liver > heart > kidney > (whole blood) > lung > (testicle, spleen, brain). The highest concentration of PFOA detected in the kidney exposed to 5 mg/kg/day was 228+/-37 microg/g and PFOS in the liver exposed to 20 mg/kg/day reached the highest level of 648+/-17 microg/g, indicating that the liver, lung, and kidney might serve as the main target organs for PFCs. Furthermore, a dose-dependent accumulation of PFOS in various tissues was found. The accumulation levels of PFOS were universally higher than PFOA, which might explain the relative high toxicity of PFOS. The definite toxicity and high accumulation of the tested PFCs might pose a great threat to biota and human beings due to their widespread application in various fields.

Effects of perfluorooctane sulfonate on ion channels and glutamate-activated current in cultured rat hippocampal neurons.

Concern on an emerging persistent contaminant, perfluorooctane sulfonate (PFOS), is increasingly growing. Although the fate, transport, distribution and bioaccumulation of PFOS have been documented, its toxicological effects especially neurotoxicity remain largely unknown. In this study, the effects of PFOS on ion channels including potassium and sodium channels and exogenous glutamate-activated current in cultured rat hippocampal neurons were examined, based on whole-cell patch-clamp recording. PFOS markedly increased two subtypes of potassium currents, including transient outward current and delayed rectifier current, at doses over 10µM. PFOS did not affect the amplitude of sodium current at all administrated doses (1, 10 or 100µM) but clearly shifted the activation current-voltage curve toward negatively potential. Further, PFOS significantly altered the glutamate-activated current at all doses. Taken together these findings indicated that PFOS disturbs the neuronal physiological processes, which revealed the damage of this pollutant to nerve system and will be helpful for further exploration to its underlying mechanism.

Determination of alkali-labile phosphoprotein phosphorus from fish plasma using the Tb(3+)-tiron complex as a fluorescence probe.

A sensitive method based on the fluorescence quenching effect of the Tb(3+)-Tiron complex is proposed for the determination of alkali-labile phosphoprotein phosphorus (ALP) released from fish plasma. The detection limit was 5.4 ng/ml (S/N = 2), and the relative standard deviation of the quenching effect (6 replicates) was 4.6%. The results obtained by the proposed method were in good agreement with those obtained by the colorimetric assay. The advantages of the present method are its relatively simple detection procedure, the lack of toxic organic solvents, and high sensitivity.

Interaction of methylmercury and selenium on the bioaccumulation and histopathology in medaka (Oryzias latipes).

Interaction of methylmercury and selenium in medaka (Oryzias latipes) on bioaccumulation of pollutants and histopathological changes in liver and gill were studied. Juvenile medaka fish were submitted to a series of waterborne methylmercury chloride (MMC), sodium selenite (Na(2)SeO(3)) and their mixture for 210 days, respectively. The methylmercury (MeHg) and selenium contents in the whole body of medaka were determined. The dose- and time-dependent increase of MeHg and selenium contents in medaka were observed. Histopathological changes, such as edema, vacuoles, pyknotic nucleus, and telangiectasis, could clearly be observed in the slices from the exposed medaka's liver and gill. Concurrent exposure to MMC and Na(2)SeO(3) showed the increased selenium accumulation. When the exposure molar ratio of MeHg:Se was about 1, the interaction between MeHg and selenium offered a limited protection against the serious intoxication of both MMC and Na(2)SeO(3) to medaka.

[Study on the contamination status of butyltins in Taihu Lake].

Butyltins in surface water, sediments and biota samples from Taihu Lake were determined. The results show that butyltins content in most of the surface water samples is under the limit of the detection; five out of ten sediment samples are measured detectable butyltins. Monobutyltin (MBT) was the main species with the concentrations ranging from below the detection limits to 0.95 ng/g; while all biota samples were detected relatively higher butyltin concentrations with a range of 27.05 - 181.23 ng/g due to the obvious bioaccumulation. Tributyltin (TBT) was the main composition that occupied almost 70% of the total butyltins. The antifouling paints applied on the aquatic cultural box and boats was the possible main source of butyltin compounds in Taihu Lake.