1,720,999 research outputs found
Current strategies to prevent ishcemia reperfusion injury in organ transplantation
No full textSolid organ transplantation is inherently associated to ischemia reperfusion injury (IRI) since the operative procedure always impliesthe harvesting, preservation and implantation of the organ,whichresult in several hours of ischemia followed by reperfusion. Several strategies have been proposed to mitigate IRI in organ transplantation.However, most of them are in experimental phases and currently few are implemented in the clinical field. These strategies can be applied in 3 different stages of the transplantation procedure: on the organ donor, known as donor pre-treatment; during preservation, when ischemic organ is waiting to be implanted in the recipient or on the transplant recipient. In the present review, we will discuss the different approaches to control IRI damage in solid organ transplantation and the rationale behind them.Fil: Stringa, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentina. Universidad Favaloro; ArgentinaFil: Rumbo, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentin
Evaluation of histological damage of solid organs after donor preconditioning with thymoglobulin in an experimental rat model
Full text linkRabbit anti-rat thymoglobulin (rATG) administered to donors with brain death (BD) may improve organs quality. We explored the effects of rATG administered to BD donors in the histology of heart, lungs and small bowel in a rat experimental model. Animals were randomly assigned to 3 groups: V (n = 5) no BD, 2 h ventilation; BD (n = 5) BD and 2 h ventilation; BD and rATG: BD, 2 h ventilation, rATG (10 mg/kg) after BD diagnosis. Histopathological damage scores were based on neutrophil infiltration, airway epithelial cell damage, interstitial edema, hyaline membrane formation, and pulmonary hemorrhage (lungs); neutrophil infiltration and interstitial edema (heart); Park score (bowel). Lung damage was significantly lower in BD + rATG group: V 5 ± 1.6; BD 11.25 ± 0.5, BD + rATG 6.5 ± 1.9 (p 0.05). Small bowel: BD 2.25 ± 0.96 vs. BD + rATG 1.00 ± 1.15 (n.s.). Histological damage amelioration in lung and attenuation tendency in heart and small bowel encourages research of cytoprotective strategies to improve organ viability.Fil: Cicora, Federico. Foundation for Research & Assistance in Kidney Disease; Argentina. Hospital Alemán; ArgentinaFil: Stringa, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Guerrieri, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Vásquez, Daniela. Foundation for Research & Assistance in Kidney Disease; ArgentinaFil: Toniolo, Fernanda. Universidad Nacional de La Plata; ArgentinaFil: Roberti, Javier. Foundation for Research & Assistance in Kidney Disease; ArgentinaFil: Raimondi, Clemente. Universidad Nacional de La Plata; Argentin
Is faster always better? A comparative study between associating liver partition and portal vein ligation for staged hepatectomy vs classic portal vein ligation for two-stage hepatectomy in rats
Full text linkBackground: The associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has been proposed to avoid liver failure after major liver resection. We thought to define the mechanism by which ALPPS enlarges liver remnant and if it is really more effective than classic two-stage hepatectomy. Objectives: To compare if ALPPS is superior to portal vein ligation (PVL) to increase liver volume. Methods: Sprague-Dawley rats were divided in sham, ALPPS and PVL groups. Animal weight, volumetric assessment of the liver middle lobe, mitotic index, binucleate cells index, Ki-67 index and histological evaluation were done to assess liver regeneration. Results: No differences were found in liver volume after both procedures. (48, 65 ± 15 %, 43, 97 ± 13, 4 % and 155 ± 40 %; on 3, 7, 14 POD, for ALPPS and PVL) The liver volume/ animal weight ratios were similar in both groups. Ki67, binucleate cells and mitotic index were significantly higher in PVL and ALPPS compared with sham group, only on 3 postoperative day, (p=0.01), but were not different at the end of follow up (14 days). The histological liver damage score was slightly higher in ALPPS. Conclusion: Both procedures are useful to achieve increases in future remnant liver volume. There is no difference in the final volume reached; observing that the increase achieved by ALPPS is faster.Fil: Barros Schelotto, Pablo. Fundación Favaloro; ArgentinaFil: Moulin, Luis. Fundación Favaloro; ArgentinaFil: Meier, Dominik. Universidad Favaloro; ArgentinaFil: Almau Trenau, Hector. Fundación Favaloro; ArgentinaFil: Cabanne, Ana. Fundación Favaloro; ArgentinaFil: Descalzi, Valeria. Fundación Favaloro; ArgentinaFil: Stringa, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; Argentina. Universidad Favaloro; ArgentinaFil: Gondolesi, Gabriel Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; Argentina. Fundación Favaloro; Argentin
Defining the nonreturn time for intestinal ischemia reperfusion injury in mice
Full text linkAmong the abdominal organs, the intestine is probably the most sensitive to ischemia reperfusion injury (IRI), a phenomenon that occurs in many intestinal disorders. Few studies have reported in detail the impact of intestinal ischemia time in mice. We evaluated the effect of various warm intestinal ischemia times in an intestinal IRI model in mice. Adult male Balb/c mice were divided into 4 groups that differed in intestinal ischemia time: G1, 30; minutes; G2, 35 minutes; G3, 40 minutes; and G4, 45 minutes. Histological evaluation showed average Park scores as follows: G1 0.6 ± 0.55; G2 1.8 ± 0.45; G3 4.8 ± 2.25; and G4 5 ± 1.79. All animals from G1 survived 30 hours. G2 animals showed intermediate behavior with all succumbing between 18 and 30 hours postprocedure. G3 and G4 displayed similar survival results with animals succumbing before 6 hours after intestinal reperfusion. These data showed that Park index scores of 3 or higher were related to early death. We concluded that the 5 minutes between 35 and 40 minutes is the critical limit, after which all mice die after reperfusion. This result may represent a valuable tool for future research in mice.Fil: Stringa, Pablo Luis. Universidad Favaloro; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Laboratorio de Transplante de Órganos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lausada, Natalia Raquel. Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Laboratorio de Transplante de Órganos; Argentina. Universidad Favaloro; ArgentinaFil: Romanin, David Emmanuel. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Machuca, Mariana Alejandra. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Cátedra de Patología Especial; ArgentinaFil: Cabanne, Ana. Universidad Favaloro; ArgentinaFil: Rumbo, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Gondolesi, Gabriel Eduardo. Universidad Favaloro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Donor preconditioning with rabbit anti-rat thymocyte immunoglobulin ameliorates ischemia reperfusion injury in rat kidney transplantation
Full text linkA major concern in transplantation is the preservation of organ function. Ischemia time and microcirculatory disturbance of the organ cannot be avoided and may result in ischemia reperfusion injury (IRI), increasing the risk of delayed graft function (DGF) and acute and chronic rejection. Anti-thymocyte immunoglobulin (rATG) is a polyclonal antibody preparation with multiple effects when administered to recipients. Our objective has been to evaluate whether the administration of rATG to kidney donors instead of recipients, in an experimental model of syngeneic rat transplantation, ameliorates IRI and facilitates immediate graft function recovery. Urea and creatinine levels and necrosis severity scores were significantly lower in kidneys from donors that had received rATG (urea: control: 211 ± 8. mg/dl vs. treatment: 110 ± 15. mg/dl, p 0.05). Findings suggest ATG administered to donors may ameliorate the IRI process in kidney transplantation, expressed by lower necrosis and apoptosis scores and the improvement of renal function, which may be explained through the diminished in situ expression of inflammatory mediators.Fil: Cicora, Federico. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; Argentina. Hospital Aleman; ArgentinaFil: Roberti, Javier Eugenio. Universidad de Belgrano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lausada, Natalia Raquel. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; ArgentinaFil: González, Pedro Horacio. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Guerrieri, Diego. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Stringa, Pablo Luis. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cicora, Paola. Fundación Para la Investigación y Asistencia de la Enfermedad Renal; ArgentinaFil: Vásquez, Daniela. Fundación Para la Investigación y Asistencia de la Enfermedad Renal; ArgentinaFil: González, Ivana. Fundación Para la Investigación y Asistencia de la Enfermedad Renal; ArgentinaFil: Palti, Gustavo. Hospital Alemán; ArgentinaFil: Intile, Dante. Fundación Para la Investigación y Asistencia de la Enfermedad Renal; ArgentinaFil: Raimondi, Clemente. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; Argentin
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Immunosuppression in kidney donors with rapamycin and tacrolimus: Proinflammatory cytokine expression
Full text linkLa lesión por isquemia y reperfusión (IRI) es uno de los principales problemas en el trasplante. Nuestro objetivo fue evaluar el efecto del pre - acondicionamiento al donante con rapamicina y tacrolimus para prevenir la lesión por IRI. Las ratas Wistar donantes, 12 horas antes de la nefrectomía, recibieron fármacos inmunosupresores. La muestra se dividió en cuatro grupos experimentales: un grupo con intervención simulada (sham), un grupo control sin tratamiento, otro tratado con rapamicina (2 mg/kg) y el restante tratado con tacrolimus (0.3 mg/kg). Se retiró el riñón izquierdo y después de tres horas de isquemia fría, se lo trasplantó. Veinticuatro horas después, el órgano trasplantado se recuperó para el análisis histológico y la evaluación de la expresión de citoquinas. El tratamiento de pre-acondicionamiento con rapamicina o con tacrolimus redujo significativamente el nitrógeno ureico en sangre y los niveles de creatinina en comparación con el control (BUN: p < 0.001; creatinina: p < 0.001). La necrosis tubular aguda fue significativamente menor en las ratas donantes tratadas con inmunosupresores en comparación con el grupo control (p < 0.001). Finalmente, las citoquinas inflamatorias, como TNF-α, IL-6 y rIL-21, mostraron niveles más bajos en el injerto de los animales que recibieron tratamiento. Este estudio experimental exploratorio muestra que el pre-acondicionamiento en donantes con rapamicina y tacrolimus en dos grupos distintos mejora los resultados clínicos y anatomopatológicos en receptores, con una reducción in situ de citoquinas pro-inflamatorias relacionadas con la diferenciación Th17, y de este modo crea un ambiente favorable para la diferenciación de células T regulatorias (Tregs).The ischemia-reperfusion injury (IRI) remains a major problem in transplantation. The objective of this study was to evaluate the effects of preconditioning a donor group with rapamycin and another donor group with tacrolimus to prevent IRI. Twelve hours before nephrectomy, donor Wistar rats received immunosuppressive drugs. The sample was divided into four experimental groups: a sham group, an untreated control group, a group treated with rapamycin (2 mg/kg) and a group treated with tacrolimus (0.3 mg/kg). Left kidneys were removed and, after three hours of cold ischemia, grafts were transplanted. Twenty-four hours later, the transplanted organs were recovered for histological analysis and evaluation of cytokine expression. The pre-conditioning treatment with rapamycin or tacrolimus significantly reduced donor blood urea nitrogen and creatinine levels compared with control group (BUN: p < 0.001 vs. control and creatinine: p < 0.001 vs. control). Acute tubular necrosis was significantly lower in donors treated with immunosuppressant drugs compared with the control group (p < 0.001). Finally, inflammatory cytokines such as TNF-α, IL-6 and rIL-21 showed lower levels in the graft of pre-treated animals. This exploratory experimental study shows that preconditioning donors with rapamycin and tacrolimus in different groups improves clinical outcome and pathology in recipients and reduces in situ pro-inflammatory cytokines associated with Th17 differentiation, creating a favorable environment for the differentiation of regulatory T cells (Tregs).Fil: Cicora, Federico. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Roberti, Javier. Universidad de Belgrano; ArgentinaFil: Lausada, Natalia Raquel. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; ArgentinaFil: Gonzalez, Pedro. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Guerrieri, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Stringa, Pablo Luis. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Raimondi, Clemente. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; Argentin
- …
