Springer Science and Business Media LLC

A simple and fast method has been developed for the determination of urinary trans,trans-muconic acid (ttMA) based on micro-extraction by packed sorbent (MEPS), followed by HPLC-UV detection. Parameters affecting the performance of MEPS were investigated. The results of the MEPS-HPLC-UV procedure were compared with the results of the conventional SPE method. The procedure was used for the determination of ttMA in urine samples of benzene-exposed subjects. The calibration curve was obtained in the range of 0.1 to 2 μg/mL, and the method showed high linearity (R2=0.9997). The LOQ was 0.1 μg/mL. For the MEPS method, the withinand between-day precision ranged from 3.0 to 5.1% and 3.3 to 5.2%, respectively. The within-and between-day accuracy ranged from 93.3 to 99.3% and 91.5 to 96.0%, respectively. The developed MEPS-HPLC-UV method is suggested as an alternative to the existing conventional SPE method for the biomonitoring of benzene-exposed subjects.

Numerous types of Environmental Risk Substances (ERSs) are produced, causing exposure not only in the industry, but also in daily life in modern society. ERSs are pernicious to animals as well as to human beings, since some of them remain for long periods of time or become condensed in organisms during the ecological cycles via environmental pollution. In recent times, the quality and distribution process of animal products have been in the spotlight, and the way of thinking regarding healthy lifestyle has been changing. Thus, this calls attention to the analysis of ERSs which may impede the safety of animal products to allow the distribution of healthy products. This review covers the trends and directions on the development of biomarkers that can precisely diagnose ERS-exposed animals at the molecular level, and the new paradigm of prompt and accurate environmental risk assessment using cells and genes.

Metagenome analysis was used to monitor changes in microbial population during the industrial-scale batch fermentation period (0, 15 days and 2 years). Genomic DNA was extracted from Bachu-Kimchi samples and was sequenced using GS Junior Titanium system, which yielded a total 6886, 6271, and 6621 reads from 0, 15 days and 2 years samples, respectively. Phylogenetic analysis based on 16S rRNA sequences showed clearly that microbial population was changed depending on the fermentation process (initial, rancid, and over-ripening stage). Wessella sp. and Leuconostoc sp. became the predominant group in microbial community at the optimumrancid stage (15 days), but as the fermentation progressed more, the abundance of Lactobacillus sp. and Bacillus sp. increased (2 years). Moreover, the specific kimchi microbes in the industrial-scale fermentation process were isolated: Leuconostoc mesenteroides, Lactobacillus sakei, Lactobacillus plantarum, and Weissella koreensis.

Administration (intubation) of cypermethrin to adult male mice for 6 and 12 weeks on alternate day in 3 dose levels,1.38, 2.76 and 5.52 mg/kg body weight (bw) corresponding to 1/476, 1/238 and 1/119 of LD50 dose respectively, caused degeneration of germinal epithelium, vacuolization of seminiferous tubules and a significant decrease in i) weight of the body, testes and epididymis, ii) diameter of the seminiferous tubules and epididymal ducts and iii) serum levels of testosterone these parameters were restored to control levels, six weeks after cessation of 1.38 mg/kg bw treatment (both durations) but not after 5.52 mg/kg bw treatment within the same period. The results reveal for the first time that chronic exposure even to 5.52 mg/kg bw i.e. up to 1/119 of LD50 induces histopathological alterations and impairment in spermatogenic and steroidogenic activities of the testis which are not reversible within a period of 6 weeks.

It has been reported that low-dose total body irradiation techniques can be applied to blood cancers such as leukemia. The aim of this study is to investigate the effect of low-dose radiation-induced cell death via ferroptosis phenomenon in doxorubicin-sensitive leukemic K562 and resistant leukemic K562/Dox cancer cells. The cells were irradiated with X-rays at total doses of 0, 0.02, 0.05, and 0.1 Gy. The cell viability was determined at 48 h post-irradiation. Other biological endpoints related to ferroptosis included intracellular reactive oxygen species (ROS) that were determined at 5, 10, and 30 min post-irradiation. Also, intracellular iron, lipid peroxidation, and glutathione peroxidase (GSH-Px) were determined at 1, 4, and 24 h post-irradiation. The results showed that cell viability significantly decreased in irradiated cells when compared to non-irradiated cells. Intracellular ROS, intracellular iron, and lipid peroxidation increased in irradiated cells at all harvest time points compared to non-irradiated cells. GSH-Px decreased in irradiated cells at all harvest time points compared to non-irradiated cells. These findings suggest that low-dose radiation can induce cell death in doxorubicin-sensitive leukemic K562 and resistant leukemic K562/Dox cancer cells through ferroptosis pathways.

A laboratory exposure experiment was conducted to evaluate imposex (imposition of male sexual organ on female) induction potential of tributyltin (TBT) and triphenyltin (TPT) in rock shell,Thais clavigera. Apparent induction of imposex was observed in rock shell, exposed to TBT and TPT compound at well below 3.65 ng Sn/L respectively. Degree of imposex in female rock shell was dependent on both TBT and TPT exposure concentrations. No additive and/or synergistic effects were observed in combined exposure of TBT and TPT. Rock shell readily accumulated water borne TBT and TPT compounds in an exposure concentration and duration (62 days) dependant manner, and showed more efficient metabolic capacity for TBT than TPT. Tissue TBT concentration and degree of imposex in rock shell showed a significant positive correlation, but to a lesser extent with tissue TPT concentrations.

Heavy metals can lead to osmotic stress by disrupting the regulation of sodium ion in aquatic organisms. In this study, gene expression patterns and enzymatic activities of Na+/K+-ATPase in the monogonont rotifer, Brachionus koreanus were measured after exposure to different Cd (7.5, 15, and 30 mg/L), and Pb (0.1, 0.5, and 1.0 mg/L), respectively. As results, a significant increase in Bk Na+/K+-ATPase activity was observed after exposure to Cd and Pb in a concentration-dependent manner. Bk Na +/K +-ATPase mRNA level was significantly upregulated in the Cd-exposed group, whereas its level was reduced in the Pb-exposed group. These findings indicate that heavy metals could induce osmotic stress in B. koreanus, and Na+/K+-ATPase may be involved in cellular ho-meostasis in response to heavy metal exposure. This study is helpful for the understanding of the molecular mode of action of B. koreanus in response to heavy metals.

This study investigated the level Petroleum hydrocarbon in Ikoli creek, Bayelsa state Nigeria with focus on water and sediments. Water and sediments were assessed using standard analytical procedures. Water from surface levels and sediment samples were collected from five locations in the creek. Soxhlet extraction method and liquid-liquid techniques were used in extraction of the petroleum hydrocarbons (Total Hydrocarbon Content and Total Petroleum Hydrocarbon) from the water and sediment samples collected respectively followed by column clean up. Gas Chromatography-Flame Ionization Detector (GC-FID) was use to analyzed the Target compounds and quantified by integrating the areas of both the resolved and unresolved components. Results of analysis of THC and TPH in water ranges between 0.010 to 0.254 mg/L and Total Petroleum Hydrocarbon (TPH) values ranges between 0.001 to 0.437 mg/L in water respectively. While in sediments the Total Hydrocarbon Content (THC) values ranges between 0.01 to 1.43 mg/kg and Total Petroleum Hydrocarbon (TPH) ranges between 0.001 to 0.44 mg/kg. The THC and TPH value of sediments increases across each sampling station in the study area and these hydrocarbons are repository in nature. The results showed that some sampling station in Ikoli creek were slightly polluted with petroleum hydrocarbons and does not conform to acceptable international guideline, which can cause adverse effects to humans and aquatic life over time.

In this study, it was analyzed specific stress responses caused by heavy metals such as sodium arsenite (As(III)), cadmium nitrate (Cd) and led nitrate (Pb) using four different stress responsive genes inEscherichia coli, i.e.fabA, grpE, katG andrecA. The expression levels of these genes were quantified by semi-quantitative reverse transcription-PCR. It was found that four genes have shown different responsive patterns whenE. coli cultures were under stressful conditions caused by As(III), Cd and Pb, respectively. Therefore, in this study, the stress responsive effects caused by these heavy metals and the extent of each stress response can be analyzed using the expression levels and patterns of different stress responsive genes.