Investigation of electronic transport under mechanical strain in a molecular junction composed of a polyyne bridge connected to SWCNT electrodes.

In the present work we propose a novel treatment to investigate ballistic electron transport under mechanical strain in a 1-D molecular bridge composed of alternating simple and triple bonds (polyyne) connected between two Single-Wall Carbon Nanotube (SWCNT) electrodes. Calculations with the DFT-NEGF methodology were performed in order to analyze this system at low values of mechanical strain (compression and distension) and at equilibrium length in the presence of bias voltages applied along the longitudinal direction. The results show that, while the mechanical strain displaces the energy levels and changes the band gap in the nanotube caps, the applied bias breaks the degeneracy in the nanotube cap states and defines the electrical conductance along the system. The analysis of the PDOS suggests that the main contribution to the electrical current comes from the superposition of the nanotube cap states, which is in agreement with the transmission calculation, and this device can be employed as a transistor observed in the I-V curve.

Beware of your Cre-Ation: lacZ expression impairs neuronal integrity and hippocampus-dependent memory.

Expression of the lacZ-sequence is a widely used reporter-tool to assess the transgenic and/or transfection efficacy of a target gene in mice. Once activated, lacZ is permanently expressed. However, protein accumulation is one of the hallmarks of neurodegenerative diseases. Furthermore, the protein product of the bacterial lacZ gene is ß-galactosidase, an analog to the mammalian senescence-associated ß-galactosidase, a molecular marker for aging. Therefore we studied the behavioral, structural and molecular consequences of lacZ expression in distinct neuronal sub-populations. lacZ expression in cortical glutamatergic neurons resulted in severe impairments in hippocampus-dependent memory accompanied by marked structural alterations throughout the CNS. In contrast, GFP expression or the expression of the ChR2/YFP fusion product in the same cell populations did not result in either cognitive or structural deficits. GABAergic lacZ expression caused significantly decreased hyper-arousal and mild cognitive deficits. Attenuated structural and behavioral consequences of lacZ expression could also be induced in adulthood, and lacZ transfection in neuronal cell cultures significantly decreased their viability. Our findings provide a strong caveat against the use of lacZ reporter mice for phenotyping studies and point to a particular sensitivity of the hippocampus formation to detrimental consequences of lacZ expression. © 2016 Wiley Periodicals, Inc.

Polymorphisms in the leptin gene promoter in Brazilian beef herds.

Brazil is the world's largest producer of beef cattle; however, the quality of its herds needs to be improved. The use of molecular markers as auxiliary tools in selecting animals for reproduction with high pattern for beef production would significantly improve the quality of the final beef product in Brazil. The leptin gene has been demonstrated to be an excellent candidate gene for bovine breeding. The objective of this study was to sequence and compare the leptin gene promoter of Brazil's important cattle breeds in order to identify polymorphisms in it. Blood samples of the Nellore, Guzerat, Tabapuã, and Senepol breeds were collected for genomic DNA extraction. The genomic DNA was used as a template for polymerase chain reaction (PCR) to amplify a 1575-bp fragment, which in turn was sequenced, aligned, and compared between animals of different breeds. Twenty-three single nucleotide polymorphic sites, including transitions and transversions, were detected at positions -1457, -1452, -1446, -1397, -1392, -1361, -1238, -963,-901, -578, -516, -483, -478, -470, -432, -430, -292, -282, -272, -211, -202, -170, and -147. Additionally, two insertion sites at positions -680 and -416 and two deletion sites at positions -1255 and -1059 were detected. As the promoter region of the leptin gene has been demonstrated to vary among breeds, these variations must be tested for their use as potential molecular markers for artificial selection of animals for enhanced beef production in different systems of bovine production in Brazil.

A non-destructive sampling protocol for field studies of seed dispersal by fishes.

This paper presents a standardized protocol for the non-lethal capture of fishes, sampling of stomach contents and quantification of seed dispersal efficiency by frugivorous fishes. Neotropical pacu Piaractus mesopotamicus individuals were collected with fruit-baited hooks. The diets of 110 fish were sampled using a lavage method, which retrieved >90% of stomach contents of both juveniles and adults and allowed individuals to recover within 5 min of treatment. The proportional volume of six food categories was similar for stomachs and whole digestive tracts retrieved by dissection. Fruit pulp was proportionally lower in the stomach. The abundance and species richness of intact seeds increased with fish size independent of whether only stomachs or whole digestive tracts were analysed. The analysis of stomach contents accounted for 62·5% of the total species richness of seeds dispersed by P. mesopotamicus and 96% of common seeds (seed species retrieved from more than one fish). Germination trials revealed that seed viability was similar for seeds collected from the stomach via lavage and seeds that passed through the entire digestive tract. Therefore, stomach contents provide an unbiased representation of the dietary patterns and seed dispersal of frugivorous fishes.

Comparison of the sensitivity of strains of Salmonella enterica serovar Typhimurium in the detection of mutagenicity induced by nitroarenes.

The use of strains of Salmonella enterica serovar Typhimurium with different metabolic capacities can indicate the class or classes of compounds present in an environmental sample and enable the diagnosis of the mutagenic activity of these pollutants adsorbed on particulate matter (PM) in the air. In the present study, the sensitivity of Salmonella strains TA98NR, TA98/1,8-DNP6, YG1021, and YG1024 to detect nitro compounds adsorbed on samples of PM 2.5 was compared from three sites in Rio de Janeiro city. Samples were collected using a high-volume sampler at three sites: one with light traffic and two with heavy traffic. The assays were performed in the presence of 10-50 µg/ plate organic extracts with and without exogenous metabolization. The YG1021 and YG1024 strains showed the highest rev/m(3) values, confirming their enhanced sensitivity. As YG1024 also demonstrated sensitivity to nitro and amino compounds, we suggest its use in research into environmental contamination.

Neonatal detection of Turner syndrome by real-time PCR gene quantification of the ARSE and MAGEH1 genes.

Turner syndrome (TS) is characterized by the presence of one full X chromosome and total or partial deletion of the second sex chromosome. Diagnosis of TS is often delayed, resulting in inappropriate treatment. Early diagnosis of TS using a neonatal screening test may improve preventive measures and treatment, thus improving patient quality of life. The goal of this study was to standardize a neonatal TS screening algorithm. Two study genes (ARSE and MAGEH1) and 1 normalizing gene (HBB) were used to detect the second X chromosome. We screened 996 newborns whose peripheral blood was collected and stored in filter paper. In addition, samples from 20 patients with confirmed diagnosis of TS were included in the study. Relative amounts of ARSE/HBB were determined using real-time polymerase chain reaction. The cutoff at the 5th percentile was arbitrarily set to indicate repetition of the test. The test was repeated in 51/1016 patients with ARSE/HBB < 0.81. For 10 samples with values persistently <0.81, we quantified the MAGEH1/HBB ratio. Values below the 95th percentile in TS patients (MAGEH1/HBB < 1.24) were considered to be inadequate. Only 6/996 NB showed inadequate values for the 2 studied genes, which were recalled for clinical evaluation and karyotype testing. Analysis of 20 patients diagnosed with TS allowed for identification of false-negatives and true-positives, establishing 95% sensitivity when the indicated cutoff values were used. In conclusion, our algorithm reached 95% detection sensitivity with an acceptable recall rate (0.6%), allowing for the detection of suspected TS cases in the neonatal period.

Prediction of health risk due to polycyclic aromatic hydrocarbons present in urban air in Rio de Janeiro, Brazil.

Risk assessment can provide a comprehensive estimate of potential effects of contaminants under specific, well-defined, and well-described circumstances, providing quantitative relationships between exposure and effects to identify and to define areas of concern. We investigated the mutagenic activity of particulate matter in air samples collected from three sites in Rio de Janeiro city. Samples were collected using a high-volume sampler at Avenida Brasil, at Campus of Universidade do Estado do Rio de Janeiro, and at Rebouças Tunnel. Six polycyclic aromatic hydrocarbons were quantified by gas chromatography/mass spectrometry. Salmonella typhimurium TA98 and the derivative strains TA98/1.8-DNP(6), YG1021, and YG1024, commonly used in mutagenicity assays, were treated (10-50 µg/plate), with and without exogenous metabolization. The highest values for the polycyclic aromatic hydrocarbons were detected at Rebouças Tunnel. For chrysene, as an example, the concentration was nearly 200 times higher than that established by the US Environmental Protection Agency. Frequent traffic jams can place bus drivers who go through the Rebouças Tunnel at risk of exposure to up to 0.69 ng/m(3) benzo(a) pyrene. Independent of exogenous metabolization, mutagenicity was detected in strains YG1021 and YG1024 at all the sites, suggesting nitro and amino derivatives of polycyclic aromatic hydrocarbons. Rebouças Tunnel air samples gave the highest values for rev/µg and rev/m(3). This could be due to the fact that the long, enclosed passageway through a mountain restricts ventilation. The cancer risk estimate in this study was 10(-3) for the benzo(a)pyrene, at the two sites, indicating a high risk.

One-year mortality and associated factors in patients undergoing surgery for hip fracture. / Mortalidad al año y factores asociados en pacientes llevados a cirugía por fractura de cadera.

INTRODUCTION: Hip fractures are very common injuries in elderly patients and are associated with increased mortality. OBJECTIVE: To identify the factors associated with mortality in patients after one year of being operated for hip fracture in an Orthogeriatric Program. METHODS: We design an observational analytical study in subjects older than 65 years admitted to the Hospital Universitario San Ignacio for hip fracture who were treated in the Orthogeriatrics Program. Telephone follow-up was performed one year after admission. Data were analyzed using a univariate logistic regression model and a multivariate logistic regression model was applied to control the effect of the other variables. RESULTS: Mortality was 17.82%, functional impairment was 50.91%, and institutionalization was 13.9%. The factors associated with mortality were moderate dependence (OR=3.56, 95% CI=1.17-10.84, p=0.025), malnutrition (OR=3.42, 95% CI=1.06-11.04, p=0.039), in-hospital complications (OR=2.80, 95% CI=1.11-7.04, p=0.028), and older age (OR=1.09, 95% CI=1.03-1.15, p=0.002). The factor associated with functional impairment was a greater dependence at admission (OR=2.05, 95% CI=1.02-4.10, p=0.041), and with institutionalization was a lower Barthel index score at admission (OR=0.96, 95% CI=0.94-0.98, p=0.001). CONCLUSIONS: Our results shows that the factors associated with mortality one year after hip fracture surgery were: moderate dependence, malnutrition, in-hospital complications and advanced age. Having previous functional dependence is directly related to greater functional loss and institutionalization.

[Translated article] One-year mortality and associated factors in patients undergoing surgery for hip fracture.

INTRODUCTION: Hip fractures are very common injuries in elderly patients and are associated with increased mortality. OBJECTIVE: To identify the factors associated with mortality in patients after one year of being operated for hip fracture in an Orthogeriatric Program. METHODS: We design an observational analytical study in subjects older than 65 years admitted to the Hospital Universitario San Ignacio for hip fracture who were treated in the Orthogeriatrics Program. Telephone follow-up was performed one year after admission. Data were analyzed using a univariate logistic regression model and a multivariate logistic regression model was applied to control the effect of the other variables. RESULTS: Mortality was 17.82%, functional impairment was 50.91%, and institutionalization was 13.9%. The factors associated with mortality were moderate dependence (OR=3.56, 95% CI=1.17-10.84, p=0.025), malnutrition (OR=3.42, 95% CI=1.06-11.04, p=0.039), in-hospital complications (OR=2.80, 95% CI=1.11-7.04, p=0.028), and older age (OR=1.09, 95% CI=1.03-1.15, p=0.002). The factor associated with functional impairment was a greater dependence at admission (OR=2.05, 95% CI=1.02-4.10, p=0.041), and with institutionalization was a lower Barthel index score at admission (OR=0.96, 95% CI=0.94-0.98, p=0.001). CONCLUSIONS: Our results shows that the factors associated with mortality one year after hip fracture surgery were: moderate dependence, malnutrition, in-hospital complications and advanced age. Having previous functional dependence is directly related to greater functional loss and institutionalization.

Cross reaction between proteins from Larrea divaricata Cav. (jarilla) and cellular and extracellular proteins of Pseudomonas aeruginosa.

Larrea divaricata is widely used in folk medicine to treat different pathologies, but little is known about its immunological properties. Pseudomonas aeruginosa is an opportunistic pathogen which causes several intrahospitalary infections. We aimed to assess the immunological relation between proteins from a crude extract of L. divaricata Cav. (JPCE) and cellular and extracellular proteins (EP) of P. aeruginosa, as well as to establish the cross reactivity between proteins of both species using a mouse anti-JPCE serum. Protein profiles of JPCE and P. aeruginosa were analyzed by SDS-PAGE. The percentage of similarity of protein bands between these two species was 43-57%. However, JPCE proteins were immunogenic. The reactivity of mouse anti-JPCE antibodies against different fractions was studied by western blot. The anti-JPCE serum detected several antigenic bands on different bacterial proteins. Several common immunoreactive bands were detected (27-100%) when bacterial proteins were incubated with anti-JPCE serum (heterologous reaction) and anti-bacterial proteins serum (homologous reaction). By enzyme-linked immunosorbant assay (ELISA) assays, high titers of anti-JPCE against different types of cellular bacterial fractions were observed (1/1280-1/2080). Our data clearly demonstrate that antibodies elicited with L. divaricata crude extract are able to cross-react with cellular and EP of P.aeruginosa. These findings could be relevant in the development of alternatives therapies for patients suffering intrahospitalary opportunistic infections with P.aeruginosa.

Tuberculosis determined by Mycobacterium bovis in captive waterbucks (Kobus ellipsiprymnus) in SÃo paulo, Brazil.

Two waterbucks from São Paulo Zoo Foundation exhibited respiratory symptoms in July 2004. After euthanasia, granulommas in lungs and mediastinic lymph nodes were observed. Acid-fast bacilli isolated were identified as Mycobacterium bovis spoligotype SB0121 by PRA and spoligotyping. They were born and kept in the same enclosure with the same group, without any contact to other species housed in the zoo. This is the first detailed description of M. bovis infection in Kobus ellipsiprymnus.

Reviewing the biological activity of chitosan in the mucosa: Focus on intestinal immunity.

Chitosan is a polymer derived from the partial deacetylation of chitin with particular characteristics, such as mucoadhesiveness, tolerability, biocompatibility and biodegradability. Biomedical uses of chitosan cover a wide spectrum of applications as dietary fiber, immunoadjuvant and regulator of the intestinal microbiota or delivery agent. Chemical modification of chitosan is feasible because its reactive amino and hydroxyl groups can be modified by a diverse array of ligands, functional groups and molecules. This gives rise to numerous derivatives that allow different formulation types influencing their activity. Considering the multiple events resulting from the interaction with mucosal tissues, chitosan is a singular candidate for strategies targeting immune stimulation (i.e., tolerance induction, vaccination). Its role as a prebiotic and probiotic carrier represents an effective option to manage intestinal dysbiosis. In the intestinal scenario where the exposure of the immune system to a wide variety of antigens is permanent, chitosan increases IgA levels and favors a tolerogenic environment, thus becoming a key ally for host homeostasis.

Review of expandable dental implants.

In the last few years the dental implants market has grown both in developed and developing countries, and is associated with high aesthetic expectations and well-being. Although the success rate of commercial implants is high, some problems associated with a lack of initial stability, marginal bony resorption, and periodontal health, remain, especially with immediate placement and loading. The market offers different designs of dental implants, but cylindrical and tapered devices that are fixed to the bone via an external thread are dominant. One lesser-known but potentially useful design is the expandable dental implant (EDI). This paper presents a review of expandable dental implants that encompasses a survey of the literature, published patents, and available commercial devices. We found 15 articles: prospective human trials (n=4), human case reports (n=3), published independent discussions of other articles (n=2), three big animal trials (n=3), and in silico studies (n=3). A total of 73 published patents were found and two expandable dental implants are commercially available to date. We propose a classification system that differentiates between the expansion mechanism and the origin of the expanding action. Some expandable designs have been shown to provide good primary stability, but evidence to date is limited. We encourage future clinical and biomechanical studies to clarify and optimise the potential benefits of these implants.

Modulation of gut immune response by probiotic fermented milk consumption to control IgE in a respiratory allergy model.

Allergies are a world increasing health issue and most treatments are oriented to alleviate symptoms. Probiotics have several health benefits including the improvement of the immune system. In previous work we found that consumption of commercial probiotic fermented milk (PFM) significantly reduced specific-immunoglobulin (Ig) E in serum and lungs by increasing specific-IgG and controlled allergic response to ovalbumin (OVA) in an adult mouse respiratory allergy model. Here we continued our study determining the mechanism triggered in the gut by the PFM ingestion that influenced the results previously reported. Five groups of BALB/c mice were assessed: normal-control, basal (drinks PFM five days without OVA sensitisation), sensitisation-control (no PFM intake), previous and continuous-PFM administration. Allergen administration: 3 OVA injections (1% in PBS) followed by aerosols exposure for 7 days. We determined total secretory-IgA and cytokines in small intestine (SI) fluid; CD11b+, CD103+, IgA+ cells and cytokine producing cells in SI tissue. In lungs we analysed co-expression of CD4/interferon (IFN)-γ or CD4/interleukin (IL)-10, IgE+ cells and IL-12 production. Results: continuous intake of PFM increased the expression of CD103 marker and decreased CD11b and pro-inflammatory cytokines. Coexpression of CD4/IFN-γ was confirmed in lungs of animals that consumed PFM continuously. This group had a lower count of IgE+ cells and a higher concentration of IL-12. The consumption of PFM reinforces the mucosal barrier by increasing IgA+ cells and induces signalling from the intestine to the lungs by increasing the expression of CD103+ dendritic cells related to regulatory mechanisms. The results found in this work together with those previously reported demonstrated that the intake of PFM induces a clear balance towards the Th1 response, preventing the Th2 allergic response by controlling the previously reported IgE level. According to our model, the intake of PFM could be a good strategy to alleviate the development of allergies.

Mycosis Fungoides in Children and Adolescents: A Series of 23 Cases. / Micosis fungoide en niños y adolescentes: descripción de una serie de 23 casos.

BACKGROUND: Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma in adults and children. The prevalence has increased in some countries, but no descriptive studies of MF in the pediatric population have been done in Colombia to date. METHODS: A combined prospective-retrospective study of 128 patients with a diagnosis of MF confirmed by the dermatology department and dermatopathology laboratory of Universidad de Antioquia between 2008 and 2017. We describe the clinical and histopathologic variants, response to treatment, and progression of the disease in 23 patients under 18 years of age. RESULTS: The pediatric cases of MF accounted for 18% of all the cases on record. The median age of onset of lesions was 9 years, the median age at diagnosis was 11 years, and the median time between onset of lesions and diagnosis was 2 years. All patients were in early stages of the disease. Hypopigmented MF was the most common clinical presentation (in 52.2%), followed by classical MF (in 30.4%). Folliculotropic MF was identified in 17.4%. All patients were treated with topical corticosteroids and phototherapy. One patient received chemotherapy while still in the early stage of disease. Complete remission was achieved in 59.1% and a partial response in 40.9%. Only 2 patients remained asymptomatic for 5 years. CONCLUSION: We found hypopigmented MF to be the most common clinical presentation in patients under 18 years of age. The disease did not progress to advanced stages in any of the patients, although recurrence after treatment interruption was common.

Lipase of Candida albicans induces activation of NADPH oxidase and L-arginine pathways on resting and activated macrophages.

Candida albicans secretes various hydrolytic enzymes which are considered to be an integral part in the pathogenesis. However, the role of lipases is far from being completely understood and the direct effects of these fungal enzymes during the host-pathogen interaction remain to be established. We recently isolated and characterized an extracellular C. albicans lipase (CaLIP), and demonstrated the ability of this fungal enzyme to interact directly with macrophages (Mvarphi) and hepatocytes and to operate as a virulence factor. Herein, we explored the effects of CaLIP on Mvarphi functions such as oxidative burst and l-arginine metabolism. The study was performed in cells with different activation status: normal-resting Mvarphis and Mvarphis primed in vivo or in vitro with C. albicans. The ability of this fungal factor to modulate the above-mentioned parameters was dependent on cells status, dose, and microenvironment, where the interaction took place. These results constitute a new finding in the biology of candidiasis and could illustrate an additional evolutive advantage for the fungus in the framework of the bidirectional host-pathogen interaction.

The biocompatible polysaccharide chitosan enhances the oral tolerance to type II collagen.

Chitosan is a mucoadhesive polysaccharide that promotes the transmucosal absorption of peptides and proteins. At mucosal sites chitosan exhibits immunomodulatory activities and stimulates the release of regulatory cytokines. Herein we evaluated the effect of the co-administration of chitosan in the tolerance to type II collagen (CII) using an experimental model of arthritis. Rats were fed diluent (acetic acid), 1 mg CII, 1 mg chitosan or 1 mg CII + 1 mg chitosan during 5 days before immunization with CII in Freund's complete adjuvant. Systemic effects were evaluated in draining lymph nodes after antigenic challenge or during the clinical evolution of arthritis. Specific antibodies, proliferation against CII and the production of interferon (IFN)-gamma and interleukin-10 were assessed. Clinical signs were observed 13-15 days after primary immunization. The CII : chitosan group presented the lowest incidence and developed moderate arthritis, with reduced levels of immunoglobulin (Ig)G2a anti-CII, a limited proliferation in draining lymph nodes and a lower release of IFN-gamma after restimulation with CII. Our results demonstrate that chitosan enhances the tolerance to an articular antigen with a decrease in the inflammatory responses and, as a consequence, an improvement in clinical signs.

[Calcifying fibrous pseudotumor of the mesentery: an unusual case in a 9-year-old girl]. / Pseudotumor fibroso calcificado del mesenterio: un caso inusual en una niña de 9 años.

INTRODUCTION: Calcifying fibrous pseudotumor is a rare benign lesion with few peritoneal and mesenteric cases in pediatric population described. Its course is mainly asymptomatic, which is why diagnosis corresponds mostly to incidental findings. CLINICAL CASE: Authors present the case of a 9-year-old patient with abdominal pain, and intra-abdominal mass finding in abdominal tomography. The histopathological study realized established diagnosis of calcifying fibrous pseudotumor, which is why programmed resection of the mass was performed by laparotomy. Follow-up was performed during one year, without evidence of recurrences through ecography. COMMENTS: Authors discuss the diagnostic and therapeutic approach in this patient compared to that described in the literature.

INTRODUCCION: El pseudotumor fibroso calcificado es una lesión benigna, con pocos casos de localización peritoneal y mesentérica descritos en la población pediátrica. Su curso es principalmente asintomático, por lo cual el diagnóstico corresponde en su mayoría a hallazgos incidentales. CASO CLINICO: Se presenta el caso de una paciente de 9 años con dolor abdominal y hallazgo de masa entra-abdominal en tomografía de abdomen. El estudio histopatológico realizado estableció el diagnóstico de pseudotumor fibroso calcificado, por lo que se llevó a resección programada de la masa mediante laparotomía. El seguimiento de la paciente fue durante un año, sin evidencia de recurrencias en ecografía. COMENTARIOS: Se discute la aproximación diagnóstica y terapéutica en esta paciente comparado con lo descrito en la literatura.

Methodology for digital radiography simulation using the Monte Carlo code MCNPX for industrial applications.

This work presents a methodology for digital radiography simulation for industrial applications using the MCNPX radiography tally. In order to perform the simulation, the energy-dependent response of a BaFBr imaging plate detector was modeled and introduced in the MCNPX radiography tally input. In addition, a post-processing program was used to convert the MCNPX radiography tally output into 16-bit digital images. Simulated and experimental images of a steel pipe containing corrosion alveoli and stress corrosion cracking were compared, and the results showed good agreement between both images.