Evaluation of Antifungal Activity of Ag Nanoparticles Synthetized by Green Chemistry against Fusarium solani and Rhizopus stolonifera.

Silver nanoparticles (AgNPs) have aroused great interest for applications as fungicides in agriculture. This study reports the synthesis of AgNPs by green chemistry using silver nitrate (AgNO3) as the precursor agent and a coriander leaf extract as the reducing agent and surfactant. The evaluation of their antifungal properties was carried out when placed in contact with Fusarium solani and Rhizopus stolonifer phytopathogens. The extract and AgNP characterizations were performed using UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), dynamic light scattering (DLS) and scanning electron microscopy (SEM). The evaluation of antifungal properties was carried out by exposing the phytopathogens to different concentrations of AgNPs in PDA (Potato Dextrose Agar). It was found that it was possible to identify the presence of flavones and flavonoids in the extract, compounds that were also involved in the synthesis process of AgNPs. In addition, the UV-Vis analysis of the obtained AgNPs by green chemistry showed resonance peaks at around 428 nm. Furthermore, a high distribution of AgNP sizes, with high concentrations of below 100 nm, was identified, according to DLS measurements. Using SEM images, the information provided by DLS was confirmed, and a crystallite size of 29.24 nm was determined with the help of XRD measurements. Finally, when exposing the phytopathogens to the action of AgNPs, it was concluded that, at a concentration of 1 mg/mL AgNPs, their growth was totally inhibited.

Biochemical characterization and insecticidal activity of isolated peptides from the venom of the scorpion Centruroides tecomanus.

The venom of scorpions is a mixture of components that constitute a source of bioactive molecules. The venom of the scorpion Centruroides tecomanus contains peptides toxic to insects, however, to date no toxin responsible for this activity has yet been isolated and fully characterized. This communication describes two new peptides Ct-IT1 and Ct-IT2 purified from this scorpion. Both peptides contain 63 amino acids with molecular weight 6857.85 for Ct-IT1 and 6987.77 Da for Ct-IT2. The soluble venom was separated using chromatographic techniques of molecular size exclusion, cationic exchange, and reverse phase chromatography, allowing the identification of at least 99 components of which in 53 the insecticidal activity was evaluated. The LD50 determined for Ct-IT1 is 3.81 µg/100 mg of cricket weight, but low amounts of peptides (0.8 µg of peptide) already cause paralysis in crickets. The relative abundance of these two peptides in the venom is 2.1% for Ct-IT1 and 1% for Ct-IT2. The molecular masses and N-terminal sequences of both insecticidal toxins were determined by mass spectrometry and Edman degradation. The primary structure of both toxins was compared with other known peptides isolated from other scorpion venoms. The analysis of the sequence alignments revealed the position of a highly conserved amino acid residue, Gly39, exclusively present in anti-insect selective depressant ß-toxins (DBTXs), which in Ct-IT1 and Ct-IT2 is at position Gly40. Similarly, a three-dimensional structure of this toxins was obtained by homology modeling and compared to the structure of known insect toxins of scorpions. An important similarity of the cavity formed by the trapping apparatus region of the depressant toxin LqhIT2, isolated from the scorpion Leiurus quinquestriatus hebraeus, was found in the toxins described here. These results indicate that Ct-IT1 and Ct-IT2 toxins have a high potential to be evaluated on pests that affect economically important crops to eventually consider them as a potential biological control method.

Prevention of incisional hernia with a reinforced tension line (RTL) versus primary suture only in midline laparotomies: 3-year follow-up in a randomized clinical trial.

PURPOSE: Incisional hernia (IH) has an incidence of 10-23%, which can increase to 38% in specific risk groups. The objective of this study is to report the results at 3 years of follow-up of the use of the reinforced tension line (RTL) technique compared with primary suture only (PSO) closure in the prevention of IH in high-risk patients undergoing laparotomy. METHODS: Open randomized controlled clinical trial. Included were patients older than 18 years who underwent midline laparotomy, emergency or scheduled, who were considered high risk, and who completed 3-year follow-up. The patients were randomized 1:1 to the RTL technique or to PSO. The objective was to report the incidence of IH and the complications associated with the closure method. Intention-to-treat analysis and Cox regression were performed. RESULTS: A total of 124 patients were randomized; 51 patients from the RTL group and 53 patients from the PSO group finished the 3-year follow-up. The incidence of IH was higher in the PSO group (15/53, 28.3%) than the RTL group (5/51, 9.8%) (p = 0.016, OR 0.35, 95% CI 0.14-0.88, number needed to treat 5.4, log-rank test p = 0.017). The groups were similar in the rates of surgical site infection, hematoma, seroma, and postoperative pain during follow-up. CONCLUSIONS: The RTL technique is useful in the prevention of IH when compared with PSO in high-risk midline laparotomy patients, and it is not associated with a higher percentage of complications. TRIAL REGISTRATION: Local Committee CI-HRAEB-2013-020. March 13, 2013. CLINICAL TRIALS: NCT02136628, retrospectively registered.

Dataset of working mPEG-alkyne with scCO2.

This article contains data related to the research article entitled "Carbon dioxide sorption and melting behavior of mPEG-alkyne". The presented data gives information on the thermodynamics properties of the solvent and the polymer. The time saturation of mPEG-alkyne in supercritical carbon dioxide (scCO2) was evaluated in a high-pressure variable volume cell in different period of time at different pressure at the same temperature. The effects of pressure and temperature on the density of CO2 when it is above supercritical conditions are determined with Sanchez Lacombe and Bender Equation and compared with the NIST database and values of equation of Bender. The characteristic parameters of CO2 were determined with the equations proposed by Chengyong Wang et al. [1] and the sum of squared error was calculated for each parameter. Furthermore in this work the solubility data of scCO2/polymer mixture were correlated with Sanchez Lacombe Equation of State (SL EOS) and Heuristic model proposed by Irene Pasquali et al. [2]. This work describes the methodology for solving the SL EOS between the polymer and scCO2 and the procedure of determining the solubility parameter with the group contribution method necessary to apply the heuristic model is described.

Molecular epidemiology of methicillin-resistant Staphylococcus aureus from different population groups in Argentina.

OBJECTIVES: In Latin America, methicillin-resistantStaphylococcus aureus (MRSA) is a leading cause of nosocomial infections. Limited studies have addressed the molecular epidemiology of MRSA clones in Argentina, characterised by continuous human migratory movements. The aim of this study was to describe the MRSA epidemiology, including distinct patient populations from different regions of the country. METHODS: MRSA strains were collected in epidemiological studies conducted from 2009 to 2015 in three cities (Formosa, Córdoba and Tucumán) and involving four population groups: community adult patients; hospitalised adults; hospitalised children; and healthy children (nasal colonisation). Antimicrobial susceptibility testing, SCCmec and Panton-Valentine leukocidin (PVL) typing, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were performed. RESULTS: A total of 120 MRSA isolates were recovered with an important population diversity in the groups studied; in community adult patients, MRSA isolates corresponded to ST5, ST267 and ST1619; from hospitalised adults they were ST97, ST5, ST72, ST125, ST200, ST647, ST747, ST935 and ST2941; from hospitalised children they were ST5, ST30, ST34, ST1163 and ST1619; and from colonised children they were ST5, ST125, ST34, ST100, ST1619, ST207 and ST1163. Results of SCCmec typing showed SCCmec I, SCCmec IIIA, SCCmec IV and SCCmec ND associated or not with PVL genes. CONCLUSIONS: MRSA genetic lineages have differing distribution in the three regions. The most prevalent was ST5 in colonisation, community and invasive settings. Here we describe ST34-SCCmec IV clone for the first time in the hospitalised paediatric population. These findings contribute to the understanding of epidemiological changes in recent years.

Social Cognition in Autism and Schizophrenia Spectrum Disorders: The Same but Different?

Social cognition impairment is a core shared phenotype in both schizophrenia spectrum disorders (SSD) and autism spectrum disorders (ASD). This study compares social cognition performance through four different instruments in a sample of 147 individuals with ASD or SSD and in healthy controls. We found that both clinical groups perform similarly to each other and worse than healthy controls in all social cognition tasks. Only performance on the Movie for the Assessment of Social Cognition (MASC) test was independent of age and intelligence. Proportionately, individuals in the control group made significantly more overmentalization errors than both patients group did and made fewer undermentalization errors than patients with SSD did. AUC analyses showed that the MASC was the instrument that best discriminated between the clinical and control groups. Multivariate analysis showed negative symptom severity as a potential mediator of the association between social cognition deficit and poor global functioning.

Virulence factors and clinical patterns of multiple-clone hypermucoviscous KPC-2 producing K. pneumoniae.

Carbapenemase-producing Klebsiella pneumoniae (CRKP) are increasingly reported worldwide being necessary the local epidemiological monitoring. Our aim was to characterize the hypermucoviscous CRKP isolates collected in our hospital during a 6 months period. Carriage of the carbapenemase genes (bla KPC, bla NDM, bla VIM and bla OXA-48), extended spectrum ß-lactamases (bla SHV-2, bla CTX-M) and the virulence genes (magA, k2A, rmpA, wabG, uge, allS, entB, ycfM, kpn, wcaG, fimH, mrkD, iutA, iroN, hly and cnf-1) were determined by multiplex-PCR. Genetic relationship among the isolates was performed by PFGE and MLST. A total of 35 isolates were recovered, being the urinary and respiratory tract the most common infection sites (34.2%). The bla KPC-2 gene was present in all the isolates, coexisting with bla CTX-M-2 (45.7%), bla SHV-2 (28.6%), and bla CTX-M-2/bla SHV-2 (14.3%). The capsular serotype K2 corresponded with 68.6% of the isolates. Virulence factors frequency were variable [adhesins (97.1%), siderophores (94.3%) and phagocytosis resistance (wabG 48.5%, uge 80% and ycfM 57.1%)]. A total of 10 STs were identified although 40% of them clustered on ST25-CC65, and 17% to ST17. The incidence of KPC-2-producing K. pneumoniae reported by the hospital was 0.290 per 1000 admissions. In summary we described an epidemic scenario of multidrug resistant hypermucoviscous KPC-2 producing ST25 K. pneumoniae in our institution.

Molecular composition of the paralyzing venom of three solitary wasps (Hymenoptera: Pompilidae) collected in southeast Mexico.

The chemical and biological characterization of peptide and protein components of the paralyzing venom from three Pompilidae solitary spider wasps (Pepsis mexicana, Pepsis terminata, and Anoplius nigritus) is described for the first time. The molecular masses of the most abundant peptides were determined. The N-terminal sequences of two cysteine-rich peptides were obtained from Pepsis. Metalloproteinase and hyaluronidase activities were identified in the venom of P. mexicana. A novel non-lethal method to collect venom is described.

Efficient multicolor tunability of ultrasmall ternary-doped LaF3 nanoparticles: energy conversion and magnetic behavior.

Luminescence-tunable multicolored LaF3:xCe3+,xGd3+,yEu3+ (x = 5; y = 1, 5, 10, and 15 mol%) nanoparticles have been synthesized via a low cost polyol method. Powder X-ray diffraction and high-resolution transmission electron microscopy studies confirm the hexagonal phase of the LaF3:xCe3+,xGd3+,yEu3+ nanophosphors with average sizes (oval shape) ranging from 5 to 7 nm. Energy-dispersive X-ray spectroscopy analyses show the uniform distribution of Ce3+, Gd3+, and Eu3+ dopants in the LaF3 host matrix. The photoluminescence spectra and electron paramagnetic resonance measurements guarantee the presence of Eu2+, corroborated through DC susceptibility measurements of the samples displaying paramagnetic behavior at 300 K, whereas weak ferromagnetic ordering is shown at 2 K. The non-radiative energy transfer processes from the 4f(2F5/2) → 5d state (Ce3+) to the intraconfigurational 4f excited levels of rare earth ions and simultaneous emissions in the visible region from the 4f65d1 (Eu2+) and 5D0 (Eu3+) emitting levels, leading to overlapped broad and narrow emission bands, have been proclaimed. The energy transfer mechanism proposes involvement of the Gd3+ ion sub-lattice as the bridge and finally trapping by Eu2+/3+, upon excitation of the Ce3+ ion. The calculation of experimental intensity parameters (Ω2,4) has been discussed and the highest emission quantum efficiency (η = 85%) of the Eu3+ ion for the y = 10 mol% sample is reported. The advantageous existence of the Eu2+/Eu3+ ratio along with variously doped nanomaterials described in this work, results in tunable emission color in the blue-white-red regions, highlighting the potential application of the samples in solid-state lighting devices, scintillation devices, and multiplex detection.

Pi5 and Pi6, two undescribed peptides from the venom of the scorpion Pandinus imperator and their effects on K+-channels.

This work reports the isolation, chemical and functional characterization of two previously unknown peptides purified from the venom of the scorpion Pandinus imperator, denominated Pi5 and Pi6. Pi5 is a classical K+-channel blocking peptide containing 33 amino acid residues with 4 disulfide bonds. It is the first member of a new subfamily, here defined by the systematic number α-KTx 24.1. Pi6 is a peptide of unknown real function, containing only two disulfide bonds and 28 amino acid residues, but showing sequence similarities to the κ-family of K-channel toxins. The systematic number assigned is κ-KTx2.9. The function of both peptides was assayed on Drosophila Shab and Shaker K+-channels, as well as four different subtypes of voltage-dependent K+-channels: hKv1.1, hKv1.2, hKv1.3 and hKv1.4. The electrophysiological assays showed that Pi5 inhibited Shaker B, hKv1.1, hKv1.2 and hKv1.3 channels with Kd = 540 nM, Kd = 92 nM and Kd = 77 nM, respectively, other studied channels were not affected. Of the channels tested only hKv1.2 and hKv1.3 were inhibited at 100 nM concentration of Pi6, the remaining current fractions were 68% and 77%, respectively. Thus, Pi5 and Pi6 are high nanomolar affinity non-selective blockers of hKv1.2 and hKv1.3 channels.

Design and expression of recombinant toxins from Mexican scorpions of the genus Centruroides for production of antivenoms.

This manuscript describes the design of plasmids containing the genes coding for four main mammalian toxins of scorpions from the genus Centruroides (C.) of Mexico. The genes that code for toxin 2 of C. noxius (Cn2), toxin 2 from C. suffusus (Css2) and toxins 1 and 2 from C. limpidus (Cll1 and Cll2) were included into individual plasmids carrying the genetic construction for expression of fusion proteins containing a leader peptide (pelB) that directs the expressed protein to the bacterial periplasm, a carrier protein (thioredoxin), the cleavage site for enterokinase, the chosen toxin and a poly-histidine tag (6xHis-tag) for purification of the hybrid protein by immobilized metal ion affinity chromatography after expression in Escherichia coli strain BL21 (DE3). The purified hybrid proteins containing the recombinant toxins (abbreviated Thio-EK-Toxin) were used for immunization of three independent groups of ten mice and four rabbits. Challenging the first group of mice, immunized with recombinant Thio-EK-Css2, with three median lethal doses (LD50) of C. suffusus soluble venom resulted in the survival of all the test animals without showing intoxication symptoms. All control mice (none immunized) died. Similar results were obtained with mice previously immunized with Thio-EK-Cn2 and challenged with C. noxius venom. The third group of mice immunized with both Thio-EK-Cll1 and Thio-EK-Cll2 showed an 80% survival ratio when challenged with only one LD50 of C. limpidus venom, all showing symptoms of intoxication. The sera from rabbits immunized with a combination of the four recombinant toxins were collected separately and used to assess their neutralization capacity in vitro (pre-incubating the serum with the respective scorpion venom and injecting the mixture into mice), using six mice for each serum/venom combination tested. The venoms from the six most dangerous scorpion species of Mexico were assayed: C. noxius, C. suffusus, C. limpidus, C. elegans, C. tecomanus and C. sculpturatus. Two hundred and 50 µL of serum from any of the immunized rabbits were enough to neutralize three LD50 of any of the tested venoms, with mice showing no symptoms of intoxication. These results confirm that the recombinant forms of the main toxins from the most dangerous scorpions of Mexico are excellent immunogens for the production of antivenoms to treat scorpion intoxications.

Expanding functions of ADP-ribosylation in the maintenance of genome integrity.

Cell response to genotoxic stress requires a complex network of sensors and effectors from numerous signaling and repair pathways, among them the nuclear poly(ADP-ribose) polymerase 1 (PARP1) plays a central role. PARP1 is catalytically activated in the setting of DNA breaks. It uses NAD+ as a donor and catalyses the synthesis and subsequent covalent attachment of branched ADP-ribose polymers onto itself and various acceptor proteins to promote repair. Its inhibition is now considered as an efficient therapeutic strategy to potentiate the cytotoxic effect of chemotherapy and radiation or to exploit synthetic lethality in tumours with defective homologous recombination mediated repair. Still, efforts made on understanding the role of PARylation in DNA repair continues to yield novel discoveries. Over the last years, our knowledge in this field has been particularly advanced by the discovery of novel biochemical and functional properties featuring PARP1, by the characterization of the other PARP family members and by the identification of a panel of enzymes capable of erasing poly(ADP-ribose). The aim of this review is to provide an overview of these newest findings and their relevance in genome surveillance.

Synthesis, phase composition, Mössbauer and magnetic characterization of iron oxide nanoparticles.

The present work describes the synthesis of iron oxide nanoparticles by thermal decomposition of Fe-precursors in argon and vacuum environments with control over particle size distribution, phase composition and the resulting magnetic properties. The Rietveld refinement analysis of X-ray diffraction data revealed the crystallinity as well the single-phase of γ-Fe2O3 nanoparticles prepared under vacuum, whereas the argon environment leads to the formation of multi-phase composition of γ-Fe2O3/Fe3O4 (90%) and wustite (10%). Synchrotron X-ray absorption near edge structure (XANES) indicates that the predominant phase in both samples is γ-Fe2O3, which is subsequently verified from the Mössbauer spectra. DC magnetic measurements indicate behavior typical of a superparamagnetic system validated by Mössbauer analysis. However, further investigation of ac susceptibility by typical Néel-Arrhenius and Vogel Fulcher magnetic models suggests an influence of interparticle interactions on the overall magnetic behavior of the system.

[Peroral endoscopic full and partial-thickness myotomy. A viability study in an animal model]. / Miotomía endoscópica por vía oral de espesor total y parcial. Estudio de factibilidad en un modelo animal.

BACKGROUND: Peroral endoscopic myotomy has recently been developed and performed on patients with good results. AIMS: To evaluate the technical feasibility of peroral endoscopic full-thickness and partial thickness myotomy in a porcine model. MATERIAL AND METHODS: Eighteen criollo pigs were randomly assigned to 2 groups: group A (partial-thickness myotomy) and group B (full-thickness myotomy). The mucosal defect proximal to the myotomy site was left open. On the seventh postoperative day the pig was euthanized and follow-up surgical exploration was performed. The duration of each procedure, postoperative progression of the animal, complications, and anatomopathologic findings were registered. RESULTS: The procedure was viable in all the pigs. The mean surgery duration was 81±35.3min (group A 51.11±11.12, group B 111±22.61; P<.05). The main complication during myotomy was subcutaneous emphysema (16%). The histopathologic study of the group A surgical specimens reported complete circular myotomy in all cases, and complete circular and longitudinal myotomy was reported in 100% of the group B sample. CONCLUSIONS: The endoscopic myotomy technique is feasible. Endoscopic partial-thickness myotomy was associated with shorter surgery duration and better results during the intraoperative period and the 7-day follow-up.

Scorpion venom components that affect ion-channels function.

The number and types of venom components that affect ion-channel function are reviewed. These are the most important venom components responsible for human intoxication, deserving medical attention, often requiring the use of specific anti-venoms. Special emphasis is given to peptides that recognize Na(+)-, K(+)- and Ca(++)-channels of excitable cells. Knowledge generated by direct isolation of peptides from venom and components deduced from cloned genes, whose amino acid sequences are deposited into databanks are nowadays in the order of 1.5 thousands, out of an estimate biodiversity closed to 300,000. Here the diversity of components is briefly reviewed with mention to specific references. Structural characteristic are discussed with examples taken from published work. The principal mechanisms of action of the three different types of peptides are also reviewed. Na(+)-channel specific venom components usually are modifier of the open and closing kinetic mechanisms of the ion-channels, whereas peptides affecting K(+)-channels are normally pore blocking agents. The Ryanodine Ca(++)-channel specific peptides are known for causing sub-conducting stages of the channels conductance and some were shown to be able to internalize penetrating inside the muscle cells.

Toxin modulators and blockers of hERG K(+) channels.

The K(+) channel encoded by the Ether-á-go-go-Related Gene (ERG) is expressed in different tissues of different animal species. There are at least three subtypes of this channel, being the sub-type 1 (ERG1) crucial in the repolarization phase of the cardiac action potential. Mutations in this gene can affect the properties of the channel producing the type II long QT syndrome (LQTS2) and many drugs are also known to affect this channel with a similar side effect. Various scorpion, spider and sea anemone toxins affect the ERG currents by blocking the ion-conducting pore from the external side or by modulating channel gating through binding to the voltage-sensor domain. By doing so, these toxins become very useful tools for better understanding the structural and functional characteristics of these ion channels. This review discusses the interaction between the ERG channels and the peptides isolated from venoms of these animals. Special emphasis is placed on scorpion toxins, although the effects of several spider venom toxins and anemone toxins will be also revised.

Interacting sites of scorpion toxin ErgTx1 with hERG1 K+ channels.

Peptides purified from scorpion venoms were shown to interact with specific amino acid residues present in the outer vestibule of various sub-types of potassium channels, occluding the pore and causing a decrement of K(+) permeability through the membrane of excitable and non excitable cells. This communication describes the identification of several interacting sites of toxin ErgTx1, a toxin purified from the venom of the scorpion Centruroides noxius, with the human ERG1 K(+) channels, by means of site-directed mutagenesis of specific residues of the toxin. Recombinant mutants of the gene coding for ErgTx1 were expressed heterologously in Escherichia coli, properly folded and their affinities and interactions with hERG1 channels were determined by patch-clamp techniques. Residues in position Y14, Y17 and F37 of the solvent exposed hydrophobic surface, and charged residues at the position K13 and K38 of ErgTx1 were shown to cause a decrement of the affinity from 20 folds to 3 orders of magnitude, thus suggesting that they are certainly participating on the binding surface of this toxin towards the hERG1 channels. Double mutants at positions K13 and F37, Y14 and F37, Y17 and F37 and K13 and K38 were also prepared and assayed, but the results obtained are not much different from the single point mutants of ErgTx1. The results of the present work indicate the most probable surface area of ErgTx1 that makes contact with the hERG channels.

Quantum critical Kondo quasiparticles probed by ESR in ß-YbAlB4.

Electron spin resonance (ESR) can probe conduction electrons (CE) and local moment (LM) spin systems in different materials. A CE spin resonance (CESR) is observed in metallic systems based on light elements or with enhanced Pauli susceptibility. LM ESR can be seen in compounds with paramagnetic ions and localized d or f electrons. Here we report a remarkable and unprecedented ESR signal in the heavy-fermion superconductor ß-YbAlB4 [S. Nakatsuji et al., Nature Phys. 4, 603 (2008)] which behaves as a CESR at high temperatures and acquires characteristics of the Yb³âº LM ESR at low temperature. This dual behavior strikes as an in situ unique observation of the Kondo quasiparticles in a quantum critical regime. The proximity to a quantum critical point may favor the appearance of this dual character of the ESR signal in ß-YbAlB4.