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Resumen Introducción: La duodeno pancreatectomía cefálica es una operación compleja cuyos resultados a corto plazo son multifactoriales. Objetivo: Evaluar el impacto de la curva de aprendizaje en los resultados a corto plazo de la duodenopancreatectomía cefálica en un hospital de nivel II. Materiales y Método: Se analizaron los datos obtenidos a partir de una base de datos mantenida prospectivamente desde 2005. Se definieron dos periodos de tiempo: de 2005 a 2011 y de 2012 a 2017. Se compararon la morbilidad, mortalidad y estancia postoperatoria de ambos períodos. Resultados: Durante el período de tiempo estudiado se hicieron 126 duodenopancreatectomías cefálicas, 61 durante la primera etapa y 65 durante la segunda. La tasa de transfusión intraoperatoria se redujo de 33% a 15% (p = 0,011). La tasa de transfusión postoperatoria se redujo de 39 a 23% (p = 0,021). No hubo diferencias significativas con respecto a la incidencia global de complicaciones postoperatorias (59% y 52,3%). La incidencia de abscesos intraabdominales fue significativamente menor en el segundo período (18% y 4,6%, respectivamente; p = 0,038). La tasa de reintervenciones se redujo significativamente, de 22% a 9% (p = 0,049). También se redujo significativamente la tasa de mortalidad, de 6,56% a 0% (p = 0,032). La estancia media postoperatoria disminuyó significativamente en el segundo período, pasando de 19,6 a 15,8 días (p = 0,001), con una mayor proporción de pacientes dados de alta en los 8 primeros días de postoperatorio (11,5% y 38,5%, respectivamente; p = 0,001). Conclusión: La curva de aprendizaje es un factor que permite mejorar los resultados de la duodenopancreatectomía cefálica, en un hospital de nivel II, hasta alcanzar valores similares a los de un hospital de nivel III.

Resumen Introducción: La duodeno pancreatectomía cefálica es una operación compleja cuyos resultados a corto plazo son multifactoriales. Objetivo: Evaluar el impacto de la curva de aprendizaje en los resultados a corto plazo de la duodenopancreatectomía cefálica en un hospital de nivel II. Materiales y Método: Se analizaron los datos obtenidos a partir de una base de datos mantenida prospectivamente desde 2005. Se definieron dos periodos de tiempo: de 2005 a 2011 y de 2012 a 2017. Se compararon la morbilidad, mortalidad y estancia postoperatoria de ambos períodos. Resultados: Durante el período de tiempo estudiado se hicieron 126 duodenopancreatectomías cefálicas, 61 durante la primera etapa y 65 durante la segunda. La tasa de transfusión intraoperatoria se redujo de 33% a 15% (p = 0,011). La tasa de transfusión postoperatoria se redujo de 39 a 23% (p = 0,021). No hubo diferencias significativas con respecto a la incidencia global de complicaciones postoperatorias (59% y 52,3%). La incidencia de abscesos intraabdominales fue significativamente menor en el segundo período (18% y 4,6%, respectivamente; p = 0,038). La tasa de reintervenciones se redujo significativamente, de 22% a 9% (p = 0,049). También se redujo significativamente la tasa de mortalidad, de 6,56% a 0% (p = 0,032). La estancia media postoperatoria disminuyó significativamente en el segundo período, pasando de 19,6 a 15,8 días (p = 0,001), con una mayor proporción de pacientes dados de alta en los 8 primeros días de postoperatorio (11,5% y 38,5%, respectivamente; p = 0,001). Conclusión: La curva de aprendizaje es un factor que permite mejorar los resultados de la duodenopancreatectomía cefálica, en un hospital de nivel II, hasta alcanzar valores similares a los de un hospital de nivel III. Introduction: The duodenum pancreatectomy cephalic is a complex operation whose short-term results are multifactorial. Aim: To assess the impact of the learning curve on the short-term outcomes of cephalic duodenopancreatectomy at a level II hospital. Materials Method: We analyze the data obtained from a database maintained prospectively since 2005. Two time periods were defined: from 2005 to 2011 and from 2012 to 2017. The morbidity, mortality and postoperative stay of both periods were compared. Results: 126 cephalic duodenopancreatectomies were performed, 61 during the first period and 65 during the second. The intraoperative transfusion rate was reduced from 33% to 15% (p = 0.011). The postoperative transfusion rate was reduced from 39 to 23% (p = 0.021). There were no significant differences with respect to the overall incidence of postoperative complications (59% and 52.3%, respectively). However, the incidence of intra-abdominal abscesses was significantly lower in the second period (18% and 4.6%, respectively, p = 0.038). The rate of reoperations was significantly reduced, from 22% to 9% (p = 0.049). The mortality rate was also significantly reduced, from 6.56% to 0% (p = 0.032). The mean postoperative stay decreased significantly in the second period, from 19.6 to 15.8 days (p = 0.001), with a higher proportion of patients discharged in the first 8 postoperative days (11.5% and 38.5%, respectively, p = 0.001). Conclusion: The learning curve is a factor allows improving the results of cephalic pancreaticoduodenectomy, in a level II hospital, until reaching values similar to those of a level III hospital.

Sediments from Rías of A Coruña, Ferrol, Betanzos and Ares (n = 26) and the Bay of Santander (n = 11) were sampled. The concentration of organic contaminants in sediment elutriates (CBs, PAHs, pesticides and pharmaceutical drugs) and sea urchin (Paracentrotus lividus) embryotoxicity were assessed. The concentration of organic pollutants in the elutriates were relatively low (ΣContaminants < 400 ng/L) and their interpretation in terms of the observed toxicity was not straightforward. A clear gradient of toxicity from the inner part to the outer side of the Santander Bay was observed. Sediment elutriates from two stations situated close to the city of A Coruña showed moderate toxicity values, whereas sediment elutriates from the Rías of Ares and Betanzos showed no marked toxicity. Stations located close to the city of Ferrol showed moderate to high toxicity, which is indicative of a nearby source of contamination. On the contrary, the outer side of the Ría of Ferrol was classified as clean according to the calculated toxic units. These results allowed for an integrative assessment of the environmental quality in the studied areas, which highlights the usefulness of embryo-larval test to monitor the coastal pollution.

Clostridium difficile is a nosocomial pathogen identified as the cause of antibiotic associated diarrhea and colitis. In this study, we have documented the lysogeny of a C. difficile bacteriophage in hamsters during C. difficile infection. The lysogens isolated from the hamsters were toxin typed and their phage integration site was confirmed by PCR. Through toxin ELISA it was found that the toxin production in the in vivo isolated lysogens was affected due to ΦCD119 lysogenization as in the case of in vitro isolated ΦCD119 lysogens. Together our findings indicate that a baceriophage can lysogenize its C. difficile host even during the infection process and highlights the importance of lysogeny of C. difficile phages as an evolutionary adaptation for survival.

Clostridium difficile produces two toxins, A and B, which act together to cause pseudomembraneous colitis. The genes encoding these toxins, tcdA and tcdB , are part of the pathogenicity locus, which also includes tcdC , a putative negative regulator of the toxin genes. In this study, we demonstrate that TcdC is a membrane-associated protein in C. difficile .

In this study, we have isolated a temperate phage (ΦCD119) from a pathogenic Clostridium difficile strain and sequenced and annotated its genome. This virus has an icosahedral capsid and a contractile tail covered by a sheath and contains a double-stranded DNA genome. It belongs to the Myoviridae family of the tailed phages and the order Caudovirales . The genome was circularly permuted, with no physical ends detected by sequencing or restriction enzyme digestion analysis, and lacked a cos site. The DNA sequence of this phage consists of 53,325 bp, which carries 79 putative open reading frames (ORFs). A function could be assigned to 23 putative gene products, based upon bioinformatic analyses. The ΦCD119 genome is organized in a modular format, which includes modules for lysogeny, DNA replication, DNA packaging, structural proteins, and host cell lysis. The ΦCD119 attachment site attP lies in a noncoding region close to the putative integrase ( int ) gene. We have identified the phage integration site on the C. difficile chromosome ( attB ) located in a noncoding region just upstream of gene gltP , which encodes a carrier protein for glutamate and aspartate. This genetic analysis represents the first complete DNA sequence and annotation of a C. difficile phage.

To test the effects of lidocaine and bupivacaine on early fracture healing, the tensile strength of five groups of femora from normal rats 14 and 35 days after production of a closed diaphyseal fracture were compared. Data indicate that, in experimental animals injected with local anesthetics at the fracture site, no measurable difference is noted in callus composition, tensile strength, or histological appearance during the early phases of fracture repair prior to callus remodeling.

A bacteriophage specific for Clostridium difficile was examined for its ability to prevent ileocecitis in a hamster model. This species- and strain-specific bacteriophage was isolated from a lysogenic strain of C. difficile . Hamsters were maintained in sterile isolation cages to prevent the acquisition of C. difficile from the environment. Bicarbonate neutralization of gastric acidity was necessary for bacteriophage survival in the hamster's gastrointestinal tract. Bacteriophage recovery from the hamster cecum was 2×10 4 plaque forming units/mL of cecal contents 24 h after orogastric challenge with 10 8 plaque forming units/mL of bacteriophage. However, there was no bacteriophage recovery 48 h post challenge, indicating dissipation of bacteriophage from the hamster intestinal tract within this time frame. Twenty-four hours after being challenged with clindamycin, one group of hamsters was challenged with C. difficile followed by a single dose of bacteriophage (10 8 plaque forming units/mL). Two additional groups of hamsters received phage doses immediately after C. difficile challenge and subsequently thereafter every 8 h up to 48 and 72 h, respectively. The gastric acidity was neutralized with bicarbonate buffer preceding every bacteriophage treatment. Control animals that received only clindamycin and C. difficile died within 96 h after challenge while the majority of bacteriophage treated hamsters survived. Two weeks after stopping bacteriophage treatment, the surviving hamsters were re-challenged with clindamycin and C. difficile . All the hamsters died within 96 h indicating susceptibility of the surviving hamsters to C. difficile disease in the absence of bacteriophage treatment.

Grand-canonical like descriptions of many electron atomic and molecular open systems which are characterized by a non-integer number of electrons are presented. Their associated reduced density matrices (RDMs) are obtained by introducing the contracting mapping for this type of distributions. It is shown that there is loss of information when connecting RDMs of different order by partial contractions. The energy convexity property of these systems simplifies the description. Consequently, this formulation opens the possibility to a new look for chemical descriptors such as chemical potential and reactivity among others. Examples are presented to discuss the theoretical aspects of this work. © 2013 AIP Publishing LLC. Fil:Bochicchio, R.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Rial, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

A novel appropriate definition for the density matrix for an interacting Coulombic driven atomic or molecular system with non-integer number of particles is given. Our approach leads to a direct derivation of the proposal reported by Perdew [Phys. Rev. Lett. 49, 1691 (1982)]10.1103/PhysRevLett.49.1691 and points out its suitability and perspective advances. © 2012 American Institute of Physics. Fil:Bochicchio, R.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Rial, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

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A receptor for Clostridium difficile toxin A was purified from brush border membranes (BBMs) from the small intestine of infant hamsters. The BBMs were solubilized with Triton X-114, and the solubilized receptor was purified with use of a toxin A immobilized affinity-chromatography column and differential temperature elution. SDS-PAGE and silver staining of the purified receptor revealed numerous high-molecular-weight bands. However, ligand blotting analysis with 125I-toxin A used as the probe identified a 163-kD protein as the predominate toxin A-binding molecule. Toxin A bound to the purified receptor at physiological temperature, but the amount of toxin bound increased at lower temperatures. Bovine thyroglobulin bound to toxin A and inhibited its binding to the purified receptor. Preincubation of the receptor with lectins produced by Bandeirea simplicifolia or Datura stramonium reduced specific binding by 125I-toxin A. Our data indicate that the purified toxin A receptor from small intestine BBMs of infant hamsters is a galactose- and N-acetylglucosamine-containing glycoprotein.

Clostridium difficile has been identified as the most important single identifiable cause of nosocomial antibiotic-associated diarrhea and colitis. Virulent strains of C. difficile produce two large protein toxins, toxin A and toxin B, which are involved in pathogenesis. In this study, we examined the effect of lysogeny by ΦCD119 on C. difficile toxin production. Transcriptional analysis demonstrated a decrease in the expression of pathogenicity locus (PaLoc) genes tcdA , tcdB , tcdR , tcdE , and tcdC in ΦCD119 lysogens. During this study we found that repR , a putative repressor gene of ΦCD119, was expressed in C. difficile lysogens and that its product, RepR, could downregulate tcdA :: gusA and tcdR :: gusA reporter fusions in Escherichia coli . We cloned and purified a recombinant RepR containing a C-terminal six-His tag and documented its binding to the upstream regions of tcdR in C. difficile PaLoc and in repR upstream region in ΦCD119 by gel shift assays. DNA footprinting experiments revealed similarities between the RepR binding sites in tcdR and repR upstream regions. These findings suggest that presence of a CD119-like temperate phage can influence toxin gene regulation in this nosocomially important pathogen.