Partition coefficients of methylated DNA bases obtained from free energy calculations with molecular electron density derived atomic charges

Partition coefficients serve in various areas as pharmacology and environmental sciences to predict the hydrophobicity of different substances. Recently, they have also been used to address the accuracy of force fields for various organic compounds and specifically the methylated DNA bases. In this study, atomic charges were derived by different partitioning methods (Hirshfeld and Minimal Basis Iterative Stockholder) directly from the electron density obtained by electronic structure calculations in a vacuum, with an implicit solvation model or with explicit solvation taking the dynamics of the solute and the solvent into account. To test the ability of these charges to describe electrostatic interactions in force fields for condensed phases, the original atomic charges of the AMBER99 force field were replaced with the new atomic charges and combined with different solvent models to obtain the hydration and chloroform solvation free energies by molecular dynamics simulations. Chloroform-water partition coefficients derived from the obtained free energies were compared to experimental and previously reported values obtained with the GAFF or the AMBER-99 force field. The results show that good agreement with experimental data is obtained when the polarization of the electron density by the solvent has been taken into account, and when the energy needed to polarize the electron density of the solute has been considered in the transfer free energy. These results were further confirmed by hydration free energies of polar and aromatic amino acid side chain analogs. Comparison of the two partitioning methods, Hirshfeld-I and Minimal Basis Iterative Stockholder (MBIS), revealed some deficiencies in the Hirshfeld-I method related to the unstable isolated anionic nitrogen pro-atom used in the method. Hydration free energies and partitioning coefficients obtained with atomic charges from the MBIS partitioning method accounting for polarization by the implicit solvation model are in good agreement with the experimental values. © 2018 Wiley Periodicals, Inc.

Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth

The unexpectedly high flux of cosmic-ray positrons detected at Earth may originate from nearby astrophysical sources, dark matter, or unknown processes of cosmic-ray secondary production. We report the detection, using the High-Altitude Water Cherenkov Observatory (HAWC), of extended tera-electron volt gamma-ray emission coincident with the locations of two nearby middle-aged pulsars (Geminga and PSR B0656+14). The HAWC observations demonstrate that these pulsars are indeed local sources of accelerated leptons, but the measured tera-electron volt emission profile constrains the diffusion of particles away from these sources to be much slower than previously assumed. We demonstrate that the leptons emitted by these objects are therefore unlikely to be the origin of the excess positrons, which may have a more exotic origin.

Correction: Lung and heart-lung transplantation in pulmonary arterial hypertension

[This corrects the article DOI: 10.1371/journal.pone.0187811.].

Kca3.1 Activation Via P2y2 Purinergic Receptors Promotes Human Ovarian Cancer Cell (Skov-3) Migration

Disorders in cell signaling mediated by ATP or histamine, activating specific membrane receptors, have been frequently associated with tumorigenesis. Among the elements of response to purinergic (and histaminergic) signaling, ion channel activation controls essential cellular processes in cancer, such as cell proliferation, motility, and death. Here, we studied the effects that ATP had on electrical properties of human ovarian adenocarcinoma cells named SKOV-3. ATP caused increase in intracellular Ca²⁺ concentration ([Ca²⁺]_i) and, concurrently, it evoked a complex electrical response with a conspicuous outward component. This current was generated through P2Y₂ receptor activation and opening of K⁺ channels, K_Ca3.1, as indicated by electrophysiological and pharmacological analysis, as well as by immunodetection and specific silencing of P2Y₂ or K_Ca3.1 gene by esiRNA transfection. Low µM ATP concentration increased SKOV-3 cell migration, which was strongly inhibited by K_Ca3.1 channel blockers and by esiRNA-generated P2Y₂ or K_Ca3.1 downregulation. Finally, in human ovarian tumors, the P2Y₂ and K_Ca3.1 proteins are expressed and co-localized in neoplastic cells. Thus, stimulation of P2Y₂ receptors expressed in SKOV-3 cells promotes motility through K_Ca3.1 activation. Since P2Y₂ and K_Ca3.1 are co-expressed in primary tumors, our findings suggest that they may play a role in cancer progression.

Effects of grain level on lamb performance, ruminal metabolism and leptin mRNA expression in perirenal adipose tissue

The effects of four different grain composition diets of finishing lambs on lamb performance, dry matter (DM) digestibility, rumen fermentation and leptin mRNA expression were evaluated. Thirty-two Pelibuey lambs (25.35 ± 4.73 kg bodyweight) were used in a completely randomised experiment in which lambs were fed diets that contained 30%, 45%, 60% or 75% grain (DM basis). The results indicated that increasing the grain level improved the average daily weight gain, hot carcass weight, DM digestibility and feed conversion linearly (P < 0.01); however, feed intake was not affected. Ruminal pH decreased linearly as the grain content was increased (P < 0.01). Ruminal propionate concentration increased and acetate concentration declined with increased grain content (P < 0.01). Leptin mRNA expression in perirenal adipose tissue increased linearly (P < 0.05) as grain content increased. Based on these results, we conclude that increasing grain level in the diets of finishing feedlot lambs improved weight gain and feed efficiency; however, because weight gain and feed efficiency were similar at the higher grain levels, our data suggest including 60% grain in lamb finishing rations.

[Rupture of a superior mesenteric artery aneurysm in pediatric age: case report and literature review]

INTRODUCTION

Splanchnic artery aneurysms are rare in children. High mortality from rupture justifies its treatment, with various therapeutic options among which stand out surgery and recently, endovascular treatment.

CASE REPORT

A 11 year old girl presented with abdominal pain and sudden drop in hematocrit. The urgent abdominal CT angiography showed a saccular aneurysm of the superior mesenteric artery (SMA) at 4 cm from the ostium with dissection and active bleeding. A selective angiography was performed which confirmed the dissection. A self-expanding stent was placed in the main trunk of the SMA and a transcatheter coil and onyx embolization of the aneurysm was performed. The control angiogram showed no evidence of residual perfusion of the false lumen and demonstrated proper vascularization of the distal jejunum-ileal branches. Dual antiplatelet therapy with aspirin and dipyridamole was begun. After 24 months of follow-up the patient is asymptomatic.

COMMENTS

Endovascular treatment of a SMA aneurysm is effective in the pediatric patient, even in emergency situations.

Vegetación y paisaje alrededor del lago de Montcortès (Prepirineos catalanes) como instrumento para el estudio paleoecológico de los sedimentos lacustres

El lago de Montcortès (42º 19′ N, 0º 59′ E; 1027 m altitud) posee sedimentos con laminaciones anuales, ideales para estudios paleoecológicos de alta resolución. Para el análisis palinológico de estos sedimentos, es necesario conocer en detalle la vegetación local, como fuente del polen sedimentario. El objetivo de este estudio es reconocer y cartografiar los tipos de vegetación presentes alrededor del lago, para lo cual se delimitó un área rectangular de unas 48 ha. Del estudio florístico de este espacio resultó un catálogo de 534 especies, que sirvió de base para el análisis de vegetación. Para ello, se llevaron a cabo 42 inventarios fitosociológicos, que se utilizaron para elaborar una síntesis del paisaje vegetal mediante cartografía digital. Como resultado, se obtuvieron 52 unidades de vegetación, expresión concreta de los hábitats CORINE definidos en la lista de los hábitats de Cataluña. Cada una de estas unidades se describió con criterios florísticos, fisionómicos, fitogeográficos, ambientales y de uso humano. La siguiente etapa consistirá en el estudio palinológico de las especies más representativas de los tipos de vegetación y hábitats establecidos aquí, con el fin de optimizar las interpretaciones paleoecológicas futuras.

Performance of the Sysmex UF1000i system in screening for significant bacteriuria before quantitative culture of aerobic/facultative fast-growth bacteria in a reference hospital

OBJECTIVE

To evaluate the performance of the Sysmex UF1000i automatic urine screening system in the quantitative culture of fast-growth aerobic/facultative bacteria.

METHODS AND RESULTS

A standard procedure was used to recover fast-growth aerobic/facultative micro-organisms in 1225 samples, applying (Sysmex(®)) flow cytometry for parallel bacteria and leucocyte counts. According to the area under the receiver operating characteristic curve, the optimal cut-off values to detect bacteriuria >10(5) colony forming units (CFU) ml(-1) were 690/μl for bacteria and 38/μl for leucocytes (sensitivity, 92%; specificity, 65%; positive predictive value [PPV], 39%; and negative predictive value [NPV], 97%). The use of a single cut-off point of 150 bacteria μl(-1) to detect significant bacteriuria of >10(5) CFU ml(-1) or of ≥10(4) CFU ml(-1) plus leucocyturia obtained similar results (sensitivity, 89%; specificity, 54%; PPV, 31%; and NPV, 96%) and allowed 45.7% of the samples to be rapidly excluded.

CONCLUSIONS

The Sysmex UF1000i system can be adapted for bacteriuria screening by the use of an appropriate cut-off point.

SIGNIFICANCE AND IMPACT OF THE STUDY

This screening system significantly reduces the workload and produces very few false positives and negatives.

Garlic derivatives (PTS and PTS-O) differently affect the ecology of swine faecal microbiota in vitro

A number of in vitro experiments were designed to evaluate the effects of two different industrial products, namely PROALLIUM-S-DMC and PROALLIUM-SO-DMC (DMC Research Center, Granada, Spain), obtained from garlic (Allium sativum) on the faecal microbiota of pigs. The effects of three different concentrations (50, 200 and 400 ppm) of the active compounds (PTS and PTS-O, respectively) from both industrial products on the gastrointestinal microbiota of pigs were tested. Growth medium without any additive (0 ppm) was used as control. Predominant bacterial groups (total aerobes, total anaerobes, lactobacilli, bifidobacteria, coliforms, enterobacteria, bacteroides and clostridia) were studied. Results showed that both PTS and PTS-O have significant (P<0.01) antimicrobial activity against every group studied, although enterobacteria and coliforms were the most affected populations (P<0.01). Time kill curves for Escherichia coli and Salmonella typhimurium, two common pathogens of pigs, showed that both compounds had a bactericidal effect against these strains. For the bacterial groups here studied, the antimicrobial effect of PTS-O was significantly (P<0.001) stronger than that of PTS. Trials in vivo are in course to study the potential use of these products as alternatives to antibiotics in pig feeds.

Vocal Pathologies of Difficult Diagnosis

The objective of this study was to review four vocal pathologies difficult to diagnose (vocal sulci, submucosal cysts, pseudocysts, and mucosal bridges) seen in the Principe de Asturias University Hospital Voice Unit (Alcalá de Henares, Madrid, Spain) over a 9-year period. This study was to show the prevalence of these pathologies out of the total number of benign vocal pathologies, basing our findings on clinical and stroboscopic criteria; and to analyze the stroboscopic-surgical correlation of the series over the last 3 1/2 years. This study was a retrospective review of the stroboscopies carried out between 1993 and 2002, of the suspected diagnoses offered by three ENT specialists. The data were based on the video archives of the unit and surgical notes. We reviewed 4206 stroboscopies, 189 (4.5%) corresponded to new cases. Within this group, we found the following distribution: 48% of vocal sulci, 42% of submucosal cysts, 10% of pseudocysts, and 0% of mucosal bridges. Seventy-nine percent showed unilateral pathology. The sulci showed the highest percentage of bilaterality (33%). The stroboscopic-surgical correlation (1999-2002) was positive in 69% of the sulci, 78% of the cysts, and 100% of the pseudocysts. In our series, 4.5% of the stroboscopies were performed on these groups of difficult diagnosis. For these pathologies, the stroboscopy is the exploratory method that offers more information and that allows us to obtain an optimal correlation between diagnostic suspicion and surgical evidence.

Prevalence and management of potential candidates for simultaneous pancreas-kidney transplantation in a provincial setting

INTRODUCTION

Simultaneous pancreas-kidney (SPK) transplantation is the best therapeutic option for correctly selected diabetic patients with advanced chronic kidney disease (CKD).

OBJECTIVES

The objectives of this study were to quantify in a Spanish province the prevalence and incidence of type 1 and 2 diabetics with stage IV-V CKD who are potential candidates for SPK, and to analyze the selection for SPK in clinical practice.

MATERIALS AND METHODS

All patients with diabetic neuropathy (DN) in predialysis, hemodialysis, or peritoneal dialysis (PD) in our transplantation referral area (population, 1.8 million; data collection ended December 7, 2005) were examined for basic SPK criteria (NTO 2005 Consensus). A new assessment was performed 9 months later, including new possible recipients, and patients were classified as: follows in study, excluded after study, added to SPK waiting list, or SPK-transplanted.

RESULTS

In 2005, there were 1371 patients in dialysis or predialysis, including 179 (13%) with DN (41 type 1 and 138 type 2 DM); only 16 of these patients (8.9% of DN patients), 8.9 per million population (PMP), met the basic criteria for SPK transplantation. There were 68 with DN in predialysis, including 8 (11.7%) possible SPK candidates; 7 with DN in PD, no candidates for SPK; and 104 patients with DN in hemodialysis, including 8 (7.2%) SPK candidates. After 9 months, 7 new potential candidates were identified (incidence of 5.1 PMP/y). Of 23 possible candidates, 3 refused SPK, 7 awaited completion of study, 8 were excluded after study, 1 was on the SPK waiting list, and 7 underwent SPK transplantation.

CONCLUSIONS

In our setting, approximately 9% of DN patients with stage IV-V CKD were potential SPK candidates in 2005 and 2006. After completion of studies, less than half were eventually included on the waiting list, generating an effective demand for SPK of 2-4 new patients PMP/y.