Effects of co-cropping Bidens pilosa (L.) and Tagetes minuta (L.) on bioaccumulation of Pb in Lactuca sativa (L.) growing in polluted agricultural soils

Polluted agricultural soils are a serious problem for food safety, with phytoremediation being the most favorable alternative from the environmental perspective. However, this methodology is generally time-consuming and requires the cessation of agriculture. Therefore, the purpose of this study was to evaluate two potential phytoextractor plants (the native species Bidens pilosa and Tagetes minuta) co-cropped with lettuce growing on agricultural lead-polluted soils. The concentrations of Pb, as well as of other metals, were investigated in the phytoextractors, crop species, and in soils, with the potential risk to the health of consumers being estimated. The soil parameters pH, EC, organic matter percentage and bioavailable lead showed a direct relationship with the accumulation of Pb in roots. In addition, the concentration of Pb in roots of native species was closely related to Fe (B. pilosa, r = 0.81; T. minuta r = 0.75), Cu (T. minuta, r = 0.93), Mn (B. pilosa, r = 0.89) and Zn (B. pilosa, r = 0.91; T. minuta, r = 0.91). Our results indicate that the interaction between rhizospheres increased the phytoextraction of lead, which was accompanied by an increase in the biomass of the phytoextractor species. However, the consumption of lettuce still revealed a toxicological risk from Pb in all treatments.     

Proximodistal Organization of the CA2 Hippocampal Area

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GCAT|Panel,a comprehensive structural variant haplotype map of the Iberian population from high-coverage whole-genome sequencing

The combined analysis of haplotype panels with phenotype clinical cohorts is a common approach to explore the genetic architecture of human diseases. However, genetic studies are mainly based on single nucleotide variants (SNVs) and small insertions and deletions (indels). Here, we contribute to fill this gap by generating a dense haplotype map focused on the identification, characterization, and phasing of structural variants (SVs). By integrating multiple variant identification methods and Logistic Regression Models (LRMs), we present a catalogue of 35 431 441 variants, including 89 178 SVs (≥50 bp), 30 325 064 SNVs and 5 017 199 indels, across 785 Illumina high coverage (30x) whole-genomes from the Iberian GCAT Cohort, containing a median of 3.52M SNVs, 606 336 indels and 6393 SVs per individual. The haplotype panel is able to impute up to 14 360 728 SNVs/indels and 23 179 SVs, showing a 2.7-fold increase for SVs compared with available genetic variation panels. The value of this panel for SVs analysis is shown through an imputed rare Alu element located in a new locus associated with Mononeuritis of lower limb, a rare neuromuscular disease. This study represents the first deep characterization of genetic variation within the Iberian population and the first operational haplotype panel to systematically include the SVs into genome-wide genetic studies.     

Separate taurine and chloride efflux pathways activated during regulatory volume decrease

Organic osmolyte and halide permeability pathways activated inepithelial HeLa cells by cell swelling were studied by radiotracer efflux techniques and single-cell volume measurements. The replacement of extracellular Cl byanions that are more permeant through the volume-activated Cl channel, as indicated byelectrophysiological measurements, significantly decreasedtaurine efflux. In the presence of less-permeant anions, an increase intaurine efflux was observed. Simultaneous measurement of the¹²⁵I, used as a tracer forCl, and[³H]taurine effluxshowed that the time courses for the two effluxes differed. InCl-rich medium the increasein I efflux was transient,whereas that for taurine was sustained. OsmosensitiveCl conductance, assessed bymeasuring changes in cell volume, increased rapidly after hypotonicshock. The influx of taurine was able to counteractCl conductance-dependentcell shrinkage but only ~4 min after triggering cell swelling. Thistaurine-induced effect was blocked by DIDS. Differences in anionsensitivity, the time course of activation, and sensitivity to DIDSsuggest that the main cell swelling-activated permeability pathways fortaurine and Cl are separate.

     

Determination of the triterpenoid,betulinic acid,in Doliocarpus schottianus by HPLC

The isolation, detection and quantification of betulinic acid in Doliocarpus schottianus are described. The isolation from the plant extract was made by column chromatography and centrifugal TLC, and betulinic acid was characterized by spectrometric methods. The detection and quantification were made by HPLC using a C18 column eluted with acetonitrile: water and detected at 210 nm. The results showed that the metabolite accumulates in the bark of the plant, but very small concentrations were also found in the leaves and wood.     

Aquaporin-2, a regulated water channel, is expressed in apical membranes of rat distal colon epithelium

Aquaporin-2 (AQP-2) is the vasopressin-regulated water channel expressed in the apical membrane of principal cells in the collecting duct and is involved in the urinary concentrating mechanism. In the rat distal colon, vasopressin stimulates water absorption through an unknown mechanism. With the hypothesis that AQP-2 could contribute to this vasopressin effect, we studied its presence in rat colonic epithelium. We used RT-PCR, in situ hybridization, immunoblotting, and immunocytochemistry to probe for AQP-2 expression. An AQP-2 amplicon was obtained through RT-PCR of colon epithelium RNA, and in situ hybridization revealed AQP-2 mRNA in colonic crypts and, to a lesser extent, in surface absorptive epithelial cells. AQP-2 protein was localized to the apical membrane of surface absorptive epithelial cells, where it colocalized with H(+)-K(+)-ATPase but not with Na(+)-K(+)-ATPase. AQP-2 was absent from the small intestine, stomach, and liver. Water deprivation increased the hybridization signal and the protein level (assessed by Western blot analysis) for AQP-2 in distal colon. This was accompanied by increased p-chloromercuriphenylsulfonic acid-sensitive water absorption. These results indicate that AQP-2 is present in the rat distal colon, where it might be involved in a water-sparing mechanism. In addition, these results support the idea that AQP-2, and probably other aquaporins, are involved in water absorption in the colon.     

Systematic study of high molecular weight compounds in Amazonian plants by high temperature gas chromatography-mass spectrometry

The fractions of hexane and dichloromethane extraction from marupá (Simaruba amara) and (Bertholletia excelsa) leaves were analyzed by HT-HRGC (high temperature high resolution gas chromatography) and HT-HRGC coupled to mass spectrometry (HT-HRGC-MS). Several compounds can be characterized including unusual high molecular weight compounds.     

Identification of two essential glutamic acid residues in glycogen synthase

The detailed catalytic mechanism by which glycosyltransferases catalyze the transfer of a glycosyl residue from a donor sugar to an acceptor is not known. Through the multiple alignment of all known eukaryotic glycogen synthases we have found an invariant 17-amino acid stretch enclosed within the most conserved region of the members of this family. This peptide includes an E-X(7)-E motif, which is highly conserved in four families of retaining glycosyltransferases. Site-directed mutagenesis was performed in human muscle glycogen synthase to analyze the roles of the two conserved Glu residues (Glu-510 and Glu-518) of the motif. Proteins were transiently expressed in COS-1 cells as fusions to green fluorescence protein. The E510A and E518A mutant proteins retained the ability to translocate from the nucleus to the cytosol in response to glucose and to bind to intracellular glycogen. Although the E518A variant had approximately 6% of the catalytic activity shown by the green fluorescence protein-human muscle glycogen synthase fusion protein, the E510A mutation inactivated the enzyme. These results led us to conclude that the E-X(7)-E motif is part of the active site of eukaryotic glycogen synthases and that both conserved Glu residues are involved in catalysis. We propose that Glu-510 may function as the nucleophile and Glu-518 as the general acid/base catalyst.     

Morphogenesis beyond Cytokinetic Arrest in Saccharomyces cerevisiae

The budding yeast lyt1 mutation causes cell lysis. We report here that lyt1 is an allele of cdc15, a gene which encodes a protein kinase that functions late in the cell cycle. Neither cdc15-1 nor cdc15-lyt1 strains are able to septate at 37°C, even though they may manage to rebud. Cells lyse after a shmoo-like projection appears at the distal pole of the daughter cell. Actin polarizes towards the distal pole but the septins remain at the mother–daughter neck. This morphogenetic response reflects entry into a new round of the cell cycle: the preference for polarization from the distal pole was lost in bud1 cdc15 double mutants; double cdc15-lyt1 cdc28-4 mutants, defective for START, did not develop apical projections and apical polarization was accompanied by DNA replication. The same phenomena were caused by mutations in the genes CDC14, DBF2, and TEM1, which are functionally related to CDC15. Apical polarization was delayed in cdc15 mutants as compared with budding in control cells and this delay was abolished in a septin mutant. Our results suggest that the delayed M/G1 transition in cdc15 mutants is due to a septin-dependent checkpoint that couples initiation of the cell cycle to the completion of cytokinesis.     

Urinary Tract Infections in Kidney Transplant Patients Due to Escherichia coli and Klebsiella pneumoniae-Producing Extended-Spectrum β-Lactamases: Risk Factors and Molecular Epidemiology

Urinary tract infection (UTI) is a common complication after kidney transplantation, often associated to graft loss and increased healthcare costs. Kidney transplant patients (KTPs) are particularly susceptible to infection by Enterobacteriaceae-producing extended-spectrum β-lactamases (ESBLs). A retrospective case-control study was conducted to identify independent risk factors for ESBL-producing Escherichia coli and Klebsiella pneumoniae in non-hospitalized KTPs with UTI. Forty-nine patients suffering from UTI by ESBL-producing bacteria (ESBL-P) as case group and the same number of patients with UTI by ESBL negative (ESBL-N) as control-group were compared. Clinical data, renal function parameters during UTI episodes, UTI recurrence and relapsing rate, as well as risk factors for recurrence, molecular characterization of isolates and the respective antimicrobial susceptibility profile were evaluated. Diabetes mellitus (p <0.007), previous antibiotic prophylaxis (p=0.017) or therapy (p<0.001), previous UTI (p=0.01), relapsing infection (p=0.019) and patients with delayed graft function after transplant (p=0.001) represented risk factors for infection by ESBL positive Enterobacteriaceae in KTPs. Interestingly, the period of time between data of transplantation and data of UTI was shorter in case of ESBL-P case-group (28.8 months) compared with ESBL-N control-group (50.9 months). ESBL-producing bacteria exhibited higher resistance to fluoroquinolones (p=0.002), trimethoprim-sulfamethoxazole (p<0.001) and gentamicin (p<0.001). Molecular analysis showed that bla _CTX-M was the most common ESBL encoding gene (65.3%), although in 55.1% of the cases more than one ESBL gene was found. In 29.4% of K. pneumoniae isolates, three bla-genes (bla _CTX-M-bla _TEM-bla _SHV) were simultaneously detected. Low estimated glomerular filtration rate (p=0.009) was found to be risk factor for UTI recurrence. Over 60% of recurrent UTI episodes were caused by genetically similar strains. UTI by ESBL-producing Enterobacteriaceae in KTPs represent an important clinical challenge regarding not only hospitalized patients but also concerning outpatients.