172 research outputs found
Lista de los géneros y especies de la familia Chalcididae (Hymenoptera: Chalcidoidea) de la región Neotropical
El orden Hymenoptera se ha dividido tradicionalmente en dos subórdenes “Symphyta” y Apocrita, este último a su vez dividido en dos grupos con categoría de sección o infraorden dependiendo de los autores, denominados “Parasitica” o también conocidos como Terebrantes y Aculeata (Gauld & Bolton 1988). Gauld & Hanson (1995) abandonan esta clasificación reconociendo únicamente superfamilias dentro del orden. Sin embargo muchos autores siguen utilizando la división tradicional porque consideran que es un medio práctico para separar grandes grupos de Hymenoptera en el aspecto biológic
Characterization and distribution of sedimentary facies of Cartagena Bay, Colombia.
En el análisis sedimentológico de 253 muestras de sedimentos de fondo y borde de playa de la Bahía de Cartagena, se identificaron 26 facies sedimentarias. Las muestras fueron tomadas con draga tipo Van Veen para el fondo, multimuestreador de sedimento tipo Beeker y apiques para los bordes de playa. Las muestras fueron tamizadas y se obtuvieron 15 categorías de acuerdo al tamaño de grano, posteriormente se realizó el análisis de carbonato de calcio (CaCO3) usando el calcímetro de Bernard. Los sedimentos fueron clasificados de acuerdo con el tamaño medio de grano y el contenido de CaCO3, para definir las facies sedimentarias existentes, donde la facies lodo litoclástico es la más representativa y se distribuye en la bahía interna y externa; al norte y sur de la Isla de Tierra Bomba. Se encontró que durante los últimos 30 años la distribución de las facies sedimentarias ha experimentado variaciones significativas: en la bahía interna ha disminuido el contenido de CaCO3 y al suroeste ha disminuido el tamaño de grano y el contenido de CaCO3; como resultado del creciente aporte de sedimentos del Canal de Dique y las condiciones oceanográficas presentes. Estas condiciones hidrodinámicas favorecen la meteorización y erosión de las formaciones coralinas presentes en el Caribe Colombiano.In the sedimentological analysis of 253 sediment samples from the edges and the bottom of the Cartagena bay, we identified 26 sedimentary facies. Samples were taken with Van Veen dredge for the bottom sediment Beeker multisampler and test pits for shorelines. Using the Bernard calcimeter we carried out the calcium carbonate (CaCO3) analysis in every sieved sample. Sediments were classified according to the average grain size and content of CaCO3, to define the existing sedimentary facies, where mud litoclast facies was the most representative and distributed to the north and south of the Tierra Bomba in the internal and external bay. We found that during the past 30 years the distribution of sedimentary facies has experienced significant changes: in the inner bay the content of CaCO3 has decreased and in the southwest the grain size and content of CaCO3 have decreased, as a result of the sediments contribution from Canal del Dique and present oceanographic conditions. These hydrodynamic conditions contribute to the weathering and erosion of coral formations present in the Colombian CaribbeanFil: Franco Arias, Diana Aillen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Geológico del Sur; Argentina. Universidad Industrial de Santander; ColombiaFil: Restrepo López, J. C.. Universidad del Norte; ColombiaFil: Sanabria Ruiz, N. Y.. Universidad Industrial de Santander; ColombiaFil: Gutierrez, Julio C.. Centro de Investigaciones Oceanográficas e Hidrográficas; Colombi
The hylEfm gene in pHylEfm of Enterococcus faecium is not required in pathogenesis of murine peritonitis
<p>Abstract</p> <p>Background</p> <p>Plasmids containing <it>hyl</it><sub><it>Efm </it></sub>(pHyl<sub>Efm</sub>) were previously shown to increase gastrointestinal colonization and lethality of <it>Enterococcus faecium </it>in experimental peritonitis. The <it>hyl</it><sub><it>Efm </it></sub>gene, predicting a glycosyl hydrolase, has been considered as a virulence determinant of hospital-associated <it>E. faecium</it>, although its direct contribution to virulence has not been investigated. Here, we constructed mutants of the <it>hyl</it><sub><it>Efm</it></sub>-region and we evaluated their effect on virulence using a murine peritonitis model.</p> <p>Results</p> <p>Five mutants of the <it>hyl</it><sub><it>Efm</it></sub>-region of pHyl<sub>EfmTX16 </sub>from the sequenced endocarditis strain (TX16 [DO]) were obtained using an adaptation of the PheS* system and were evaluated in a commensal strain TX1330RF to which pHyl<sub>EfmTX16 </sub>was transferred by mating; these include <it>i</it>) deletion of <it>hyl</it><sub><it>Efm </it></sub>only; <it>ii</it>) deletion of the gene downstream of <it>hyl</it><sub><it>Efm </it></sub>(<it>down</it>) of unknown function; <it>iii</it>) deletion of <it>hyl</it><sub><it>Efm </it></sub>plus <it>down</it>; <it>iv</it>) deletion of <it>hyl</it><sub><it>Efm</it></sub>-<it>down </it>and two adjacent genes; and <it>v</it>) a 7,534 bp deletion including these four genes plus partial deletion of two others, with replacement by <it>cat</it>. The 7,534 bp deletion did not affect virulence of TX16 in peritonitis but, when pHyl<sub>EfmTX16Δ7,534 </sub>was transferred to the TX1330RF background, the transconjugant was affected in <it>in vitro </it>growth versus TX1330RF(pHyl<sub>EfmTX16</sub>) and was attenuated in virulence; however, neither <it>hyl</it><sub><it>Efm </it></sub>nor <it>hyl</it><sub><it>Efm</it></sub>-<it>down </it>restored wild type function. We did not observe any <it>in vivo </it>effect on virulence of the other deletions of the <it>hyl</it><sub><it>Efm</it></sub>-region</p> <p>Conclusions</p> <p>The four genes of the <it>hyl</it><sub><it>Efm </it></sub>region (including <it>hyl</it><sub><it>Efm</it></sub>) do not mediate the increased virulence conferred by pHyl<sub>EfmTX16 </sub>in murine peritonitis. The use of the markerless counterselection system PheS* should facilitate the genetic manipulation of <it>E. faecium </it>in the future.</p
Evaluation of two adjuvants for the formulation of antitetanic vaccines
El objetivo de esta investigación fue el de comparar el comportamiento de dos adyuvantes, hidróxido de aluminio y fosfato de calcio, con dos lotes diferentes de toxoide tetánico, uno producido por cultivo agitado y el otro producido por cultivo estático. Fue evaluada la respuesta inmune generada a través de la prueba de potencia del National Institute of Health (NIH) para ga-rantizar el cumplimiento de los estándares establecidos para la prueba de potencia, en la cual se postula que la respuesta inmune generada debe ser como mínimo de 2UI/mL. Los resultados muestran que el aluminio presenta títulos más altos en la mayoría de los casos y en otros no se aprecia una diferencia significativa entre los dos adyuvantes. También se observó claramente que cualquiera de los dos adyuvantes genera una mejor respuesta inmune con el lote 69 (cultivo estático) que con el lote 11 (cultivo agitado). El análisis de varianza arroja un error de p<0,002.The objective of this research was to compare the role of two adjuvants, aluminum hydroxide and calcium phosphate, with two different tetanus toxoid batches, one obtained by stationary culture and the other one by sumerged culture. The generated immune respon-se was evaluated through the potency assay of the National Institute of Health (NIH), which states that in order to guaranty that the vaccines are within the established standards the immune response has to be at least 2UI/mL. The results indicate that aluminum hydroxide presents in most cases better titers, while in other cases no significant difference was found. Results showed also, that both adjuvants gave a better immune response with batch 69 (static culture) than with batch 11 (sumerged culture). The variance analysis showed an error of p<0.002.Incluye referencias bibliográfica
Cystic proliferation of germline stem cells is necessary to reproductive success and normal mating behavior in Medaka
The production of an adequate number of gametes is necessary for normal reproduction, for which the regulation of proliferation from early gonadal development to adulthood is key in both sexes. Cystic proliferation of germline stem cells is an especially important step prior to the beginning of meiosis; however, the molecular regulators of this proliferation remain elusive in vertebrates. Here, we report that ndrg1b is an important regulator of cystic proliferation in medaka. We generated mutants of ndrg1b that led to a disruption of cystic proliferation of germ cells. This loss of cystic proliferation was observed from embryogenic to adult stages, impacting the success of gamete production and reproductive parameters such as spawning and fertilization. Interestingly, the depletion of cystic proliferation also impacted male sexual behavior, with a decrease of mating vigor. These data illustrate why it is also necessary to consider gamete production capacity in order to analyze reproductive behavior.Fil: Arias Padilla, Luisa Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Castañeda Cortés, Diana C.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Rosa, Ivana F. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Moreno Acosta, Omar David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Hattori, Ricardo S.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Nóbrega, Rafael H.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Fernandino, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin
Airway stent complications: the role of follow-up bronchoscopy as a surveillance method.
Background: Airway stenting has become an integral part of the therapeutic endoscopic management of obstructive benign and malignant central airway diseases. Despite increased use of airway stents and frequent stent-associated complications, no clear guidelines for surveillance and maintenance exist. This study aim is to elucidate predictive factors associated with development of stent complications, as well as an optimal surveillance period for follow-up bronchoscopy for early detection and possible prevention of stent-associated complications.
Methods: Retrospective cohort study of all patients who underwent airway stent placements at our institution from April 2010 to December 2013 for benign and malignant airway diseases. Metallic, silicone (straight, Y stent, T-tube) and hybrid stents were included in the study. Stent complications were analyzed at the time of follow-up bronchoscopy performed four to six weeks after initial stent placement or earlier if patients became symptomatic.
Results: The study included 134 patients of which 147 stents were placed. Follow-up bronchoscopy was performed in 94 patients. Symptomatic status at the time of follow-up bronchoscopy was not associated with stent complications [odds ratio (OR) =1.88; 95% CI: 0.79-4.45; P=0.15]. Patient age, sex, indication for stent placement, and stent location, were not associated with development of complications (all P\u3e0.05). Compared to all other stents, hybrid stents were more likely to migrate (OR =6.60; 95% CI: 2.16-20.2; P=0.001) or obstruct by secretions (OR =2.53; 95% CI: 1.10-5.84; P=0.03). There were no complications associated with surveillance bronchoscopy.
Conclusions: Surveillance bronchoscopy within 4 to 6 weeks of stent placement may be useful for early detection of complications and their subsequent management, regardless of symptomatic status and indication for stent placement. Prospective multicenter studies are needed to compare optimal surveillance methods and the impact on patient mortality, morbidity and healthcare costs
Closure of a large lumbosacral myelomeningocele post operative defect with a human cadaveric split-thickness skin graft: a case report
Spina bifida is the most common birth defect of the central nervous system that is compatible with life, and myelomeningocele represents its most frequent form. Congenital myelomeningocele (CMM) has a worldwide incidence of 0.5 to 0.8 per 1,000 live newborns. CMM is a complex condition resulting from incomplete closure of the neural tube, mainly in the lumbosacral region. The objective of the surgical repair of the CMM is the reconstruction of all the tissue layers of the defect, avoiding possible postoperative complications. The aim of this case review is to present a re-epithelialization closure in a patient with a large CMM defect in who primary hermetic closure was not possible because there was too much tension at the edges of the defect. Therefore, human cadaveric split-thickness skin grafts were placed over the dura mater and the aponeurotic layer, covering the entire defect and an adequate healing and completely closure of the defect were observed in eight weeks. The surgical management of large meningomyelocele defects represents a major challenge and no single protocol exists for its reconstruction. The repair of an MMC defect should be performed during the first 72 hours after birth. After neurosurgical closure of the neural tube and dura, the myelomeningocele defect requires good quality skin and subcutaneous tissue with minimal wound tension for stable coverage. Human cadaveric skin grafts are considered a useful technique for temporary wound coverage because they lead to a more natural healing environment, possess ideal properties, and provide a physiological barrier that reduces microbiological contamination, in addition, it acts as a bridge to adhere to and to seal wound beds
Los Estudios Sociales de la Ciencia y la Tecnología en Colombia: grupos de investigación y colaboración
Using bibliometric methods, this work identifies some of the main socio-cognitive characteristics of the academic community of Social Studies of Science and Technology (STS) in Colombia. The analysis, based on information reported in the ScienTI platform run by the Ministry of Science, Technology, and Innovation, focuses on 248 research articles published by the members of ten research groups identified as STS. Pajek, Ucinet and, Vosviewer analysis tools were used to analyze and visualize the collaborative relationships between the groups included in the study. The results suggest that, despite having similar lines of research, there is little collaboration among the STS research groups in Colombia. We identified higher rates of collaboration between STS group members with non-STS identified research academics than between STS group members. The co-authorship network is composed of STS academics and non-STS academics, where those serving as nodes connect with mostly non-STS-academics. When there is a collaboration among STS groups, those belong to the same city. These results offer preliminary elements for the description of this community, but also show the need to broaden the exploration to other types of production, as well as to try to identify groups and researchers who, even without explicitly identifying themselves as dedicated to STS, use the theoretical-methodological repertoires and make contributions to this field
Role of mprF1 and mprF2 in the Pathogenicity of Enterococcus faecalis
Aujourd hui, Enterococcus faecalis est considéré comme l un des plus importants agents pathogènes causant des maladies nosocomiales. En raison de sa résistance innée et acquise aux antibiotiques, l identification de nouvelles cibles pour le traitement de cette bactérie est une grande priorité. Le facteur Multiple Peptide Résistance (MprF), qui a été décrit en premier chez Staphylococcus aureus, modifie le phosphatidylglycérol avec de la lysine et réduit ainsi la charge négative de l enveloppe cellulaire. Ceci a comme conséquence d augmenter la résistance aux peptides antimicrobiens cationiques (PAC). Deux gènes paralogues putatifs (mprF1 et mprF2) ont été identifiés chez E. faecalis par recherche BLAST en utilisant le gène décrit chez S. aureus. Une caractérisation de ces deux gènes d E. faecalis ainsi que des mécanismes conduisant à une résistance aux PAC, pourrait aider à développer des nouvelles stratégies thérapeutiques contre ce pathogène. Deux mutants de délétion et un double mutant ont été construits par recombinaison homologue chez E. faecalis. L analyse des phospholipides des membranes cytoplasmiques des deux mutants mprF1 et mprF2 par chromatographie sur couche mince a montré que seule l inactivation de mprF2 inhibe la synthèse de trois amino-phosphatidlyglycérol distincts (comme la Lysine-PG, l Alanine-PG et l Arginine-PG). De plus, le mutant mprF2 est également plus sensible aux PAC que la souche sauvage. La capacité de formation d un biofilm est généralement considérée comme un facteur important de virulence, ce qui est également le cas pour les entérocoques. Le mutant mprF2 montre une capacité accrue dans ce phénomène. Ceci semble être du à une augmentation de la concentration d ADN extracellulaire dans le biofilm formé par ce mutant. Curieusement, cette augmentation est indépendante d une autolyse. Le mutant mprF2 est également plus résistant à l opsonophagocytose. Cependant, le gène mprF2 ne joue aucun rôle dans les bactériémies de souris et les endocardites de rats.En revanche, aucun phénotype n a été trouvé pour un mutant mprF1 jusqu à présent. Cette mutation ne modifie ni la synthèse de l aminoacyl-PG en condition de laboratoire ni la résistance aux PAC et à l opsonophagocytose. Par conséquent, il semble que mprF2 soit le seul gène mprF fonctionnel chez E. faecalis. Néanmoins, contrairement à d autres bactéries, mprF2 ne semble pas être un facteur de virulence majeur pour cette espèce.Enterococcus faecalis is regarded nowadays as one of the most important nosocomial pathogens. Due to its innate and acquired resistance to antibiotics, identification of new targets for antimicrobial treatment of E. faecalis is a high priority. The multiple peptides resistance factor (MprF), which was first described in Staphylococcus aureus, modifies phosphatidylglycerol with lysine and reduces the negative charge of the membrane, thus increasing resistance to cationic antimicrobial peptides (CAMPs). Two putative mprF paralogs (mprF1 and mprF2) were identified in E. faecalis by Blast search using the well-described S. aureus gene as a lead. A better understanding of these two genes and mechanisms leads to enterococcal resistance to CAMPs might help designing therapeutic strategies against this bacteria. Two single deletion mutants and double mutant in E. faecalis were created by homologues recombination. Analysis of cell membrane phospholipids from both mutants by thin-layer chromatography showed that inactivation of mprF2 abolished the synthesis of three distinct amino-phosphatidylglycerol (mostly likely Lysin-PG, Alanine-PG and Argine-PG). The CAMPs testing assay demonstrated that the deletion mutant of mprF2 was more susceptible to CAMPs than the wild type. Biofilm formation is usually regarded as a virulence factor which provides an important way for enterococci to cause infections. Inactivation of mprF2 led to increase the biofilm formation which we showed that it was due to the accumulation of eDNA in the biofilm, but the release of eDNA is independent from autolysis. The mprF2 mutant was resistance to killing by opsonophagocytosis more than wild type. However, the mprF2 gene plays no role in bacteremia in mice and rat endocarditis. Our results showed that non polar effect mprF1 mutant does not affect in the synthesis of aminoacyl-PG in the laboratory condition. It also has no effect on susceptible to CAMPs, opsonic killing and autolysis. Therefore, it seems that mprF2 is the only functional mprF gene in E. faecalis in the laboratory condition. Unlike mprF found in other bacteria, mprF does not seem to be a major virulence factor in enterococci.CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF
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