Current strategies to prevent ishcemia reperfusion injury in organ transplantation

Solid 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.Facultad de Ciencias ExactasInstituto de Estudios Inmunológicos y Fisiopatológico

Tratamento prévio com adalimumabe reduz lesão pulmonar induzida por ventilação mecânica em um modelo experimental

Objective: To determine whether adalimumab administration before mechanical ventilation reduces ventilator- -induced lung injury (VILI). Methods: Eighteen rats randomized into 3 groups underwent mechanical ventilation for 3 hours with a fraction of inspired oxygen = 0.40% including a low tidal volume group (n = 6), where tidal volume = 8mL/kg and positive end-expiratory pressure = 5cmH2O; a high tidal volume group (n = 6), where tidal volume = 35mL/kg and positive end-expiratory pressure = 0; and a pretreated + high tidal volume group (n = 6) where adalimumab (100ug/kg) was administered intraperitoneally 24 hours before mechanical ventilation + tidal volume = 35mL/ kg and positive end-expiratory pressure = 0. ANOVA was used to compare histological damage (ATS 2010 Lung Injury Scoring System), pulmonary edema, lung compliance, arterial partial pressure of oxygen, and mean arterial pressure among the groups. Results: After 3 hours of ventilation, the mean histological lung injury score was higher in the high tidal volume group than in the low tidal volume group (0.030 versus 0.0051, respectively, p = 0.003). The high tidal volume group showed diminished lung compliance at 3 hours (p = 0.04) and hypoxemia (p = 0,018 versus control). Pretreated HVt group had an improved histological score, mainly due to a significant reduction in leukocyte infiltration (p = 0.003). Conclusion: Histological examination after 3 hours of injurious ventilation revealed ventilator-induced lung injury in the absence of measurable changes in lung mechanics or oxygenation; administering adalimumab before mechanical ventilation reduced lung edema and histological damage.Facultad de Ciencias Médica

Defining the nonreturn time for intestinal ischemia reperfusion injury in mice

Among 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

Protective effect of immunosuppressive treatment before orthotopic kidney autotransplantation

Background: Ischemia reperfusion injury (IRI) is one of the risk factors for delayed graft function, acute rejection and long term allograft survival after kidney transplantation. IRI is an independent antigen inflammatory process that produces tissue damage. Our objective was to study the impact of immunosuppressive treatment (IS) on IRI applying only one dose of IS before orthotopic kidney autotransplantation. Methods: Twenty-four rats allocated in four groups were studied. One group served as control (G1: autotransplanted rats without IS) and the rest received IS 12. h before kidney autotransplantation (G2: Rapamycin, G3: Mycophenolate mofetil and G4: Tacrolimus). Results: Improved renal function and systemic inflammatory response were found among IS groups compared to the control group (Delta Urea p < 0.0001; Delta Creatinine p < 0.0001; Delta C3 p < 0.001). The number of apoptotic nuclei in renal medulla in G1 was higher than in IS groups (p < 0.0001). Tubular damage was less severe in IS groups respecting G1 (p < 0.001). C3, TNF-γ and IL-6 expression in kidney samples was reduced when IS was used compared to the control group. No differences were observed among the different immunosuppressive drugs tested. However, Heme oxygenase-1(HO-1) was increased only in Rapamycin treatment. Conclusions: These data suggest that the use of IS administered before transplant attenuates the IRI process after kidney transplantation in an animal model.Fil: Cicora, Federico. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; Argentina. Hospital Alemán; Argentina. Fundación Para la Investigación y Asistencia de la Enfermedad Renal; ArgentinaFil: Lausada, Natalia Raquel. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; ArgentinaFil: Vasquez, Daniela Noris. Fundación Para la Investigación y Asistencia de la Enfermedad Renal; ArgentinaFil: Cicora, Paola. Fundación Para la Investigación y Asistencia de la Enfermedad Renal; ArgentinaFil: Guerrieri, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Farmacología; ArgentinaFil: Gonzalez, Pedro. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; ArgentinaFil: Zalazar, Gustavo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Stringa, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; ArgentinaFil: Raimondi, Jorge Clemente. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; Argentin

Galactomannan as a potential modulator of intestinal ischemia–reperfusion injury

Background: Galactomannan (GAL), a polysaccharide present on the cell wall of several fungi, has shown an ability to modulate inflammatory responses through the dectin-1 receptor in human macrophages. However, studies evaluating the modulatory properties of this polysaccharide in in vivo inflammatory scenarios are scarce. We hypothesized that GAL pretreatment would modulate local and remote damage related to intestinal reperfusion after an ischemic insult. Materials and methods: Adult male Balb/c mice were subjected to intestinal ischemia–reperfusion injury by reversible occlusion of the superior mesenteric artery, consisting of 45 min of ischemia followed by 3 or 24 h of reperfusion. Intragastric GAL (70 mg/kg) was administered 12 h before ischemia, and saline solution was used in the control animals. Jejunum, lung, and blood samples were taken for the analysis of histology, gene expression, plasma cytokine levels, and nitrosative stress. Results: Intestinal and lung histologic alterations were attenuated by GAL pretreatment, showing significant differences compared with nontreated animals. Interleukin 1β, monocyte chemoattractant protein 1, and IL-6 messenger RNA expression were considerably downregulated in the small intestine of the GAL group. In addition, GAL treatment significantly prevented plasma interleukin 6 and monocyte chemoattractant protein 1 upregulation and diminished nitrate and nitrite levels after 3 h of intestinal reperfusion. Conclusions: GAL pretreatment constitutes a novel and promising therapy to reduce local and remote damage triggered by intestinal ischemia–reperfusion injury. Further in vivo and in vitro studies to understand GAL's modulatory effects are warranted.Fil: Stringa, Pablo. Hospital Universitario la Paz; EspañaFil: Toledano, Victor. Hospital Universitario la Paz; EspañaFil: Papa Gobbi, Rodrigo. Hospital Universitario la Paz; EspañaFil: Arreola, Miguel. Hospital Universitario la Paz; EspañaFil: Largo, Carlota. Hospital Universitario la Paz; EspañaFil: Machuca, Mariana. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Aguirre, Luis A.. Hospital Universitario la Paz; EspañaFil: 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; ArgentinaFil: López Collazo, Eduardo. Hospital Universitario la Paz; EspañaFil: Hernández Oliveros, Francisco. Hospital Universitario la Paz; Españ

Trece años de experiencia en la enseñanza teórico-práctica de la microcirugía experimental

La microcirugía complementa diversas especialidades quirúrgicas a fin de magnificar la estructura a intervenir; y en profesiones no-médicas se utiliza para realizar técnicas altamente complejas en roedores de laboratorio. La enseñanza de la técnica se realiza con ejercicios de complejidad creciente hasta culminar realizando con éxito anastomosis vasculares y nerviosas en estructuras menores a los 2 mm. Estos ejercicios se llevan a cabo inicialmente en modelos inanimados y posteriormente en la rata de laboratorio. Nuestro objetivo es presentar la metodología pedagógica y los resultados obtenidos en 13 años de experiencia de enseñanza de la técnica microquirúrgica en nuestra facultad. Anualmente se dictan cursos desde el año 2000 hasta la fecha.Facultad de Ciencias Médica

Immunosuppression in kidney donors with rapamycin and tacrolimus: Proinflammatory cytokine expression

La 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

Trece años de experiencia en la enseñanza teórico-práctica de la microcirugía experimental

La microcirugía complementa diversas especialidades quirúrgicas a fin de magnificar la estructura a intervenir; y en profesiones no-médicas se utiliza para realizar técnicas altamente complejas en roedores de laboratorio. La enseñanza de la técnica se realiza con ejercicios de complejidad creciente hasta culminar realizando con éxito anastomosis vasculares y nerviosas en estructuras menores a los 2 mm. Estos ejercicios se llevan a cabo inicialmente en modelos inanimados y posteriormente en la rata de laboratorio. Nuestro objetivo es presentar la metodología pedagógica y los resultados obtenidos en 13 años de experiencia de enseñanza de la técnica microquirúrgica en nuestra facultad. Anualmente se dictan cursos desde el año 2000 hasta la fecha.Facultad de Ciencias Médica

Small bowel transplantation in rats, a multicenter experience summarizing the pitfalls to be overcome

Small Bowel transplantation in rats is a highly complex microsurgical procedure because several technical complications may lead to recipient mortality and transplant failure. Our aim was to report the most common complications associated with orthotopic and heterotopic intestinal transplantation in rats in order to identify the “pitfalls” of the procedure and prevent them. A retrospective multicenter study was performed. All participant centers have established rodent transplant procedures and trained surgeons. Two hundred ninety-three complications from 264 unsuccessful intestinal transplants were reported, representing an overall failure rate of 15% of the procedures performed. Recipient complications were most frequent than donor (257 vs. 36 p<0.0001). Excessive surgical time (11/36); severe hemorrhage (12/36) and inappropriate infusion of the preservation solution in the intestinal graft (11/36) were the most common donor complications. Arterial anastomosis bleeding (50/257), venous anastomosis bleeding (35/257) and portal vein stenosis (26/257) were the most common intraoperative complications in the recipient. To maximize success rate, surgeons should optimize time and avoid bleeding during graft dissection in the donor surgery. After performing a bloodless vascular anastomosis an adequate post-operative management of the animal is mandatory to guarantee survival.Fil: 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 Nacional de la Plata. Facultad de Ciencias Médicas. Laboratorio de Transplante de Órganos; ArgentinaFil: Andrés Moreno, Ane M.. La Paz University Hospital; EspañaFil: Lausada, Natalia Raquel. Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Laboratorio de Transplante de Órganos; ArgentinaFil: Pastor Oliver, Cristina. Biomedical Research Center from Aragón; EspañaFil: Abate, Juan C.. Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Laboratorio de Transplante de Órganos; ArgentinaFil: Vecchio, Leandro. Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Laboratorio de Transplante de Órganos; ArgentinaFil: Rumbo, Martín. Comisión Nacional de Investigación Científica y Tecnológica; Chile. Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Laboratorio de Transplante de Órganos; ArgentinaFil: Navarro Zorraquino, Marta. Biomedical Research Center from Aragón; EspañaFil: Hernández Oliveros, Francisco. La Paz University Hospital; EspañaFil: 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. Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Laboratorio de Transplante de Órganos; Argentin

Analysis of ventilator induced lung injury impact in lung and cardiac tissue in a murine model

Mechanical ventilation (MV) with high tidal volumes (Vt) leads to enormous biophysical lung damage, both in patients and in experimental animal models. From a biological point of view, however, the inflammatory response triggered by high Vt-MV and its association with the development of multisystem organ failure is still under study.Facultad de Ciencias MédicasComisión de Investigaciones Científicas de la provincia de Buenos Aire