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Increasing soil contamination of arsenic (As) and antimony (Sb) is posing a serious concern to human health. Due to insufficient studies on Sb, the biogeochemical behaviour and plant uptake of Sb are assumed to be similar to that of As. As part of extensive research unravelling As and Sb biogeochemistry and plant uptake, the diffusive gradients in thin films (DGT) technique and sequential extraction procedure (SEP) were applied to evaluate As and Sb uptake by the white icicle radish (Raphanus sativus) cultivated in diluted cattle dip soils contaminated with As only and diluted mining soils contaminated with both As and Sb under agricultural conditions. Labile As and Sb in these soils measured by DGT (CDGT), soil solution (Csol), and SEP (CSEP-labile), were compared with As and Sb bioaccumulation in R. sativus tissues. Regardless of contamination sources and measurement techniques, the results showed that As was consistently more labile than Sb although total As concentrations in two soil types were lower than total Sb. Labile As in cattle dip soils was higher than that in mining soils, although there were no significant differences in soil As concentrations. The analysis of R. sativus tissues revealed that the overall As bioaccumulation was 4.5-fold higher than for Sb, and that As translocation to shoots was limited. In contrast, considerable Sb translocation to shoots was observed. The As and Sb bioaccumulation were strongly correlated with their CSEP-labile, CDGT, and Csol (R2 = 0.87-0.99), demonstrating the effectiveness of these techniques in predicting As and Sb in the white icicle radish. Compared with the cherry bell radish previously studied, the white icicle radish exhibited higher bioaccumulation factors (BAF) for Sb, but lower BAF for As, and lower translocation of As and Sb to shoots, providing understanding of how As and Sb are accumulated by radish cultivars. Refereed/Peer-reviewed

Elevated concentrations of As and Sb impact environmental quality and human health. In this study total and bioavailable As and Sb were measured from recently and historically contaminated soils and the phytotoxicity of these soils was evaluated with Ipomoea aquatica (35-d exposure from germination) using biomass, length of plant tissues and photosynthetic efficiency. As and Sb were both present within the soil (co-contaminated). The bioavailable As and Sb in soils were determined by a Sequential Extraction Procedure (SEP) and compared to total soil concentrations and bioaccumulation in the edible parts of I. aquatica. For both As and Sb, bioavailable concentrations increased proportionally with the total soil concentrations and greater bioavailability in recently contaminated soil was observed. Tissue dry mass and length drastically reduced with increasing total and SEP-bioavailable As and Sb soil concentrations. The total soil concentration was a less sensitive measure of the phytotoxicity of As and Sb than the bioavailable fraction. Shoot length was inhibited by 50% (EC50) at bioavailable As concentrations of 80–96 mg kg−1 in both recently and historically contaminated soils; however, bioavailable Sb EC50 for shoot length was achieved at lower bioavailable concentrations, 96 (42–219) and 12 (7–19) mg kg−1 in recently contaminated soils and historically contaminated soils, respectively. Shoot biomass was inhibited by 50% (EC50) at bioavailable As concentrations of 11 (4–30) and 49 (37–65) mg kg−1 in recently and historically contaminated soils, respectively whereas this occurred at much lower bioavailable Sb concentrations, 2–5 mg kg−1 in both recently and historically contaminated soils. Aging is important in contaminated soils, it decreases the lability of As and Sb and hence their bioavailability to agricultural plants, thus posing a lower risk of exposure of these metalloids to humans through agricultural plants grown in contaminated soils.

Accurate tRNA processing is crucial for human mitochondrial genome expression, but the mechanisms of mt-tRNA cleavage and the key enzymes involved in this process are poorly characterized. At least two activities are required for proper mt-tRNA maturation: RNase P cleaving precursor molecules at the 5' end and tRNase Z at the 3' end. In human mitochondria only RNase P has been identified so far. Using RT-PCR and northern blot analyses we found that silencing of the human ELAC2 gene results in impaired 3' end of mt-tRNAs. We demonstrate this for several mitochondrial tRNAs, encoded on both mtDNA strands, including tRNA (Val) , tRNA (Lys) , tRNA (Arg) , tRNA (Gly) , tRNA (Leu(UUR)) and tRNA (Glu) . The silencing of the MRPP1 gene that encodes a subunit of mtRNase P resulted in inhibition of both 5' and 3' processing. We also demonstrate the double mitochondrial/nuclear localization of the ELAC2 protein using immunofluorescence. Our results indicate that ELAC2 functions as a tRNase Z in human mitochondria and suggest that mt-tRNase Z preferentially cleaves molecules already processed by the proteinaceous mtRNase P.

Protein complexes responsible for RNA degradation play important role in three key aspects of RNA metabolism: they control stability of physiologically functional transcripts, remove the unnecessary RNA processing intermediates and destroy aberrantly formed RNAs. In mitochondria the post-transcriptional events seem to play a major role in regulation of gene expression, therefore RNA turnover is of particular importance. Despite many years of research, the details of this process are still a challenge. This review summarizes emerging landscape of interplay between the Suv3p helicase (SUPV3L1, Suv3), poly(A) polymerase and polynucleotide phosphorylase in controlling RNA degradation in human mitochondria.

The mechanism of human mitochondrial RNA turnover and surveillance is still a matter of debate. We have obtained a cellular model for studying the role of hSuv3p helicase in human mitochondria. Expression of a dominant-negative mutant of the hSUV3 gene which encodes a protein with no ATPase or helicase activity results in perturbations of mtRNA metabolism and enables to study the processing and degradation intermediates which otherwise are difficult to detect because of their short half-lives. The hSuv3p activity was found to be necessary in the regulation of stability of mature, properly formed mRNAs and for removal of the noncoding processing intermediates transcribed from both H and L-strands, including mirror RNAs which represent antisense RNAs transcribed from the opposite DNA strand. Lack of hSuv3p function also resulted in accumulation of aberrant RNA species, molecules with extended poly(A) tails and degradation intermediates truncated predominantly at their 3′-ends. Moreover, we present data indicating that hSuv3p co-purifies with PNPase; this may suggest participation of both proteins in mtRNA metabolism.

Background: Data on the effect of laparoscopic cholecystectomy (LC) on bowel function are controversial. The aim of this study was to determine the incidence of postcholecystectomy diarrhoea (PCD) and to identify patient characteristics that can be used as predictors in daily practice. Methods: In 100 consecutive patients who underwent LC, data were obtained from clinical records and telephone survey 6–12 months postoperatively using standardized questionnaire. Results: Postoperatively, 19 patients had diarrhoea, including 17 with new onset. Two patients with preoperative and postoperative diarrhoea were excluded from further analysis. Of 98 patients (mean age 58.1 ± 19.4 years; 62 women) 34 were younger than 50 years, 33 were overweight (BMI 25–29.9 kg/cm2) and 29 were obese (BMI >30 kg/cm2). PCD was significantly associated with younger age (odds ratio (OR) 3.4; 95% confidence interval (CI) 1.16–9.96; P = 0.026), higher BMI (OR 1.1; 95%CI 1.01–1.18; P = 0.019) and food intolerance postoperatively (OR 3.4; 95%CI 1.18–10.08; P = 0.025). PCD was most common with combination of two or three of the following factors: age 25 kg/cm2. The highest risk of developing PCD was observed in obese men younger than 50 (OR 26.1), and the lowest in persons aged >50 years with BMI

A gas chromatographic-mass spectrometric (GC-MS) method in positive ion chemical ionization mode in combination with a solid phase extraction was optimized for new-generation antidepressants and their metabolites in postmortem blood, brain tissue, and hair. Twelve antidepressants and their active metabolites (i.e., mirtazapine, viloxazine, venlafaxine, citalopram, mianserin, reboxetine, fluoxetine, fluvoxamine, sertraline, maprotiline, melitracen, paroxetine, desmethylfluoxetine, desmethylmianserin, desmethylmirtazapine, desmethylsertraline, desmethylmaprotiline, desmethylcitalopram, and didesmethylcitalopram) could be quantified. In this article, in addition to the validation of the GC-MS method, four postmortem cases are discussed to demonstrate the usefulness of the described method in forensic toxicology. In these cases, sertraline, fluoxetine, citalopram, and trazodone in combination with their active metabolites were quantified. Blood concentrations ranged from subtherapeutic to toxic concentrations, while brain to plasma ratios ranged from 0.8 to 17. Hair concentrations ranged from 0.4 to 2.5 ng/mg depending on the compound and hair segment.