Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Am J Transplant ; 23(4): 577-581, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36725427

RESUMO

The current shortage of pediatric multivisceral donors accounts for the long time and mortality on the waiting list of pediatric patients. The use of donors after cardiac death, especially after the outbreak of normothermic regional perfusion, has increased in recent years for all solid organs except the intestine, mainly because of its higher susceptibility to ischemia-reperfusion injury. We present the first literature case of multivisceral donors after cardiac death transplantation in a 13-month-old recipient from a 2.5-month-old donor. Once exitus was certified, an extracorporeal membrane oxygenation circuit was established, cannulating the aorta and infrarenal vena cava, while the supra-aortic branches were clamped. The abdominal organs completely recovered from ischemia through normothermic regional perfusion (extracorporeal membrane oxygenation initially and beating heart later). After perfusion with the preservation solution, the multivisceral graft was uneventfully implanted. Two months later, the patient was discharged without any complications. This case demonstrates the possibility of reducing the time spent on the waiting list for these patients.


Assuntos
Preservação de Órgãos , Obtenção de Tecidos e Órgãos , Humanos , Criança , Lactente , Preservação de Órgãos/efeitos adversos , Doadores de Tecidos , Morte , Coleta de Tecidos e Órgãos , Perfusão
2.
Ann Surg ; 277(1): e235-e244, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34171860

RESUMO

OBJECTIVE: We aimed to assess whether native spleen preservation during visceral transplantation (VT) affects graft-versus-host-disease (GVHD) incidence. SUMMARY BACKGROUND DATA: GVHD is one of the most severe and frequently lethal hematological complications after VT procedures. Because there is no specific treatment for GVHD, it is imperative to develop a strategy to reduce donor lymphocyte engraftment and proliferation. METHODS: Our study included both clinical and experimental data. A total of 108 patients were divided into 3 groups: a native spleen preservation group, a native spleen removal with no donor spleen group, and a donor spleen included (allogeneic spleen) group. We also used an allogeneic VT rat model, in which recipients were divided into 2 groups: a native spleen preservation (+SP) group and a native spleen removal (-S) group. Skin rash appearance, histopathological changes, chimerism, and spleen effects on circulating allogeneic T-cells were assessed. RESULTS: The patients with native spleen preservation showed a lower rate of GVHD ( P <.001) and better survival ( P <.05) than those in the other groups. Skin and histological signs of GVHD were lower in the rats in the +SP group ( P <.05). The donor T-cell frequency in the bloodstream and skin was also significantly reduced when the native spleen was preserved ( P <.01 and P <.0001, respectively). CONCLUSIONS: The clinical and experimental data indicate that recipient spleen preservation protects against GVHD after VT, and donor cell clearance from the bloodstream by spleen macrophages could be the underlying mechanism. Therefore, spleen preservation should be considered in VT procedures, whenever possible.


Assuntos
Transplante de Medula Óssea , Doença Enxerto-Hospedeiro , Ratos , Animais , Camundongos , Baço , Transplante Homólogo , Linfócitos T , Camundongos Endogâmicos C57BL
3.
Transpl Int ; 36: 10803, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36713114

RESUMO

There is an urgent need to address the shortage of potential multivisceral grafts in order to reduce the average time in waiting list. Since donation after circulatory death (DCD) has been successfully employed for other solid organs, a thorough evaluation of the use of intestinal grafts from DCD is warranted. Here, we have generated a model of Maastricht III DCD in rodents, focusing on the viability of intestinal and multivisceral grafts at five (DCD5) and twenty (DCD20) minutes of cardiac arrest compared to living and brain death donors. DCD groups exhibited time-dependent damage. DCD20 generated substantial intestinal mucosal injury and decreased number of Goblet cells whereas grafts from DCD5 closely resemble those of brain death and living donors groups in terms intestinal morphology, expression of tight junction proteins and number of Paneth and Globet cells. Upon transplantation, intestines from DCD5 showed increased ischemia/reperfusion damage compared to living donor grafts, however mucosal integrity was recovered 48 h after transplantation. No differences in terms of graft rejection, gene expression and absorptive function between DCD5 and living donor were observed at 7 post-transplant days. Collectively, our results highlight DCD as a possible strategy to increase multivisceral donation and transplantation procedures.


Assuntos
Transplante de Fígado , Obtenção de Tecidos e Órgãos , Humanos , Morte Encefálica , Doadores de Tecidos , Transplante de Fígado/métodos , Intestinos , Morte , Sobrevivência de Enxerto , Estudos Retrospectivos
4.
Transpl Int ; 36: 11518, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37745640

RESUMO

Considering recent clinical and experimental evidence, expectations for using DCD-derived intestines have increased considerably. However, more knowledge about DCD procedure and long-term results after intestinal transplantation (ITx) is needed. We aimed to describe in detail a DCD procedure for ITx using normothermic regional perfusion (NRP) in a preclinical model. Small bowel was obtained from pigs donors after 1 h of NRP and transplanted to the recipients. Graft Intestinal samples were obtained during the procedure and after transplantation. Ischemia-reperfusion injury (Park-Chiu score), graft rejection and transplanted intestines absorptive function were evaluated. Seven of 8 DCD procedures with NRP and ITx were successful (87.5%), with a good graft reperfusion and an excellent recovery of the recipient. The architecture of grafts was well conserved during NRP. After an initial damage of Park-chiu score of 4, all grafts recovered from ischemia-reperfusion, with no or very subtle alterations 2 days after ITx. Most recipients (71.5%) did not show signs of rejection. Only two cases demonstrated histologic signs of mild rejection 7 days after ITx. Interestingly intestinal grafts showed good absorptive capacity. The study's results support the viability of intestinal grafts from DCD using NRP, contributing more evidence for the use of DCD for ITx.


Assuntos
Traumatismo por Reperfusão , Doadores de Tecidos , Animais , Suínos , Humanos , Perfusão , Reperfusão , Rejeição de Enxerto
5.
Clin Transplant ; 35(4): e14226, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33465824

RESUMO

BACKGROUND: Mesenchymal stromal cells (MSC) have been proposed as a promising complement to standard immunosuppression in solid organ transplantation because of their immunomodulatory properties. The present work addresses the role of adipose-derived MSC (Ad-MSC) in an experimental model of acute rejection in small bowel transplantation (SBT). MATERIAL/METHODS: Heterotopic allogeneic SBT was performed. A single dose of 1.5x106 Ad-MSC was intra-arterially delivered just before graft reperfusion. Animals were divided into CONTROL (CTRL), CONTROL+Ad-MSC (CTRL_MSC), tacrolimus (TAC), and TAC+Ad-MSC (TAC_MSC) groups. Each Ad-MSC groups was subdivided in autologous and allogeneic third-party groups. RESULTS: Rejection rate and severity were similar in MSC-treated and untreated animals. CTRL_MSC animals showed a decrease in macrophages, T-cell (CD4, CD8, and Foxp3 subsets) and B-cell counts in the graft compared with CTRL, this decrease was attenuated in TAC_MSC animals. Pro- and anti-inflammatory cytokines and some chemokines and growth factors increased in CTRL_MSC animals, especially in the allogeneic group, whereas milder changes were seen in the TAC groups. CONCLUSION: Ad-MSC did not prevent rejection when administered just before reperfusion. However, they showed immunomodulatory effects that could be relevant for a longer-term outcome. Interference between tacrolimus and the MSC effects should be addressed in further studies.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Animais , Estudos de Viabilidade , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/prevenção & controle , Humanos , Terapia de Imunossupressão
6.
Transpl Int ; 34(10): 1895-1907, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34174115

RESUMO

To review our experience using sirolimus in a single centre paediatric intestinal transplantation cohort. Intestinal transplant patients with more than 3 months follow-up were divided into two groups according to their immunosuppression regimen: tacrolimus, (TAC group, n = 45 grafts) or sirolimus (SRL group, n = 38 grafts), which included those partially or completely converted from tacrolimus to sirolimus. The indications to switch were tacrolimus side effects and immunological complications. Survival and complications were retrospectively analysed comparing both groups. SRL was introduced 9 months (0 months-16.9 years) after transplant. The main cause for conversion was worsening renal function (45%), followed by haemolytic anaemia (21%) and graft-versus-host-disease (16%). Both groups showed a similar overall patient/graft survival (P = 0.76/0.08) and occurrence of rejection (24%/17%, P = 0.36). Immunological complications did not recur after conversion. Renal function significantly improved in most SRL patients. After a median follow-up of 65.17 months, 28/46 survivors were on SRL, 26 with monotherapy, with good graft function. Over one-third of our patients eventually required SRL conversion that allowed to improve their kidney function and immunological events, without entailing additional complications or survival impairment. Further trials are warranted to clarify the potential improvement of the standard tacrolimus maintenance by sirolimus conversion or addition.


Assuntos
Transplante de Rim , Sirolimo , Criança , Rejeição de Enxerto , Humanos , Imunossupressores/uso terapêutico , Ácido Micofenólico , Estudos Retrospectivos , Sirolimo/uso terapêutico , Tacrolimo/uso terapêutico , Transplantados
7.
J Surg Res ; 249: 232-240, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31796217

RESUMO

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 1ß, 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.


Assuntos
Mucosa Intestinal/efeitos dos fármacos , Isquemia/complicações , Mananas/administração & dosagem , Traumatismo por Reperfusão/prevenção & controle , Animais , Modelos Animais de Doenças , Galactose/análogos & derivados , Humanos , Mucosa Intestinal/irrigação sanguínea , Mucosa Intestinal/patologia , Jejuno/irrigação sanguínea , Jejuno/efeitos dos fármacos , Jejuno/patologia , Masculino , Camundongos , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/patologia
8.
Transpl Int ; 33(10): 1302-1311, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32526809

RESUMO

Intestinal passenger T leukocytes are responsible for graft-versus-host disease (GvHD) in intestinal transplantation (ITx). We hypothesized that ex vivo fludarabine treatment of the bowel graft would diminish the risk of GvHD and improve overall survival post-transplant. We performed isolated heterotopic small bowel transplantations from Lewis (LEW) to Brown Norway (BN) rat strains, which generated GvHD signs from the fourth day post-transplant. These symptoms included rash, weight loss, piloerection, and diarrhea. The grafts of one of the experimental groups were immersed and sealed in cold Celsior preservation solution with 1000 µm fludarabine for 1 h, prior to its implantation into recipient animals. No histological signs of intestinal tissue alterations were observed after fludarabine treatment. Fludarabine-treated bowel recipients showed significantly later and milder clinical signs of GvHD and reduced total donor cell chimerism, as determined by flow cytometry using strain-specific anti-HLA antibodies. Additionally, fludarabine treatment prolonged recipients' overall survival (13.5 days ± 0.3 days vs. 9.2 days ± 0.5). We conclude that active modification of the intestinal leukocyte composition is advantageous in our ITx animal model. Immunosuppression with fludarabine during the surgical procedure, which could be translated directly to the clinic, protects bowel recipients from GvHD and improves overall post-transplant survival.


Assuntos
Doença Enxerto-Hospedeiro , Animais , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/prevenção & controle , Ratos , Ratos Endogâmicos Lew , Linfócitos T , Transplante Homólogo , Vidarabina/análogos & derivados
9.
Liver Transpl ; 25(9): 1375-1386, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31121085

RESUMO

Organ transplantation is the treatment of choice against terminal and irreversible organ failure. Optimal preservation of the graft is crucial to counteract cold ischemia effects. As we developed an N,N-bis-2-hydroxyethyl-2-aminoethanesulfonic acid-gluconate-polyethylene glycol (BGP)-based solution (hypothermic machine perfusion [HMP]), we aimed to analyze the use of this solution on static cold storage (SCS) of rat livers for transplantation as compared with the histidine tryptophan ketoglutarate (HTK) preservation solution. Livers procured from adult male Sprague Dawley rats were preserved with BGP-HMP or HTK solutions. Liver total water content and metabolites were measured during the SCS at 0°C for 24 hours. The function and viability of the preserved rat livers were first assessed ex vivo after rewarming (90 minutes at 37°C) and in vivo using the experimental model of reduced-size heterotopic liver transplantation. After SCS, the water and glycogen content in both groups remained unchanged as well as the tissue glutathione concentration. In the ex vivo studies, livers preserved with the BGP-HMP solution were hemodynamically more efficient and the O2 consumption rate was higher than in livers from the HTK group. Bile production and glycogen content after 90 minutes of normothermic reperfusion was diminished in both groups compared with the control group. Cellular integrity of the BGP-HMP group was better, and the histological damage was reversible. In the in vivo model, HTK-preserved livers showed a greater degree of histological injury and higher apoptosis compared with the BGP-HMP group. In conclusion, our results suggest a better role of the BGP-HMP solution compared with HTK in preventing ischemia/reperfusion injury in the rat liver model.


Assuntos
Transplante de Fígado/métodos , Soluções para Preservação de Órgãos/administração & dosagem , Preservação de Órgãos/métodos , Perfusão/métodos , Traumatismo por Reperfusão/prevenção & controle , Ácidos Alcanossulfônicos/química , Aloenxertos/irrigação sanguínea , Aloenxertos/patologia , Animais , Isquemia Fria/efeitos adversos , Modelos Animais de Doenças , Gluconatos/administração & dosagem , Gluconatos/química , Glucose/administração & dosagem , Humanos , Fígado/irrigação sanguínea , Fígado/patologia , Transplante de Fígado/efeitos adversos , Masculino , Manitol/administração & dosagem , Soluções para Preservação de Órgãos/química , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/química , Cloreto de Potássio/administração & dosagem , Procaína/administração & dosagem , Ratos , Traumatismo por Reperfusão/diagnóstico , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/patologia , Fatores de Tempo
10.
Biochem J ; 474(18): 3093-3107, 2017 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-28729426

RESUMO

Glycerol-3-phosphate acyltransferases (GPATs) catalyze the first and rate-limiting step in the de novo glycerolipid synthesis. The GPAT2 isoform differs from the other isoforms because its expression is restricted to male germ cells and cancer cells. It has been recently reported that GPAT2 expression in mouse testis fluctuates during sexual maturation and that it is regulated by epigenetic mechanisms in combination with vitamin A derivatives. Despite progress made in this field, information about GPAT2 role in the developing male germ cells remains unclear. The aim of the present study was to confirm the hypothesis that GPAT2 is required for the normal physiology of testes and male germ cell maturation. The gene was silenced in vivo by inoculating lentiviral particles carrying the sequence of a short-hairpin RNA targeting Gpat2 mRNA into mouse testis. Histological and gene expression analysis showed impaired spermatogenesis and arrest at the pachytene stage. Defects in reproductive fitness were also observed, and the analysis of apoptosis-related gene expression demonstrated the activation of apoptosis in Gpat2-silenced germ cells. These findings indicate that GPAT2 protein is necessary for the normal development of male gonocytes, and that its absence triggers apoptotic mechanisms, thereby decreasing the number of dividing germ cells.


Assuntos
Glicerol-3-Fosfato O-Aciltransferase/metabolismo , Túbulos Seminíferos/metabolismo , Espermatogênese , Espermatozoides/enzimologia , Animais , Apoptose , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Glicerol-3-Fosfato O-Aciltransferase/antagonistas & inibidores , Glicerol-3-Fosfato O-Aciltransferase/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Masculino , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência , Estágio Paquíteno , Interferência de RNA , RNA Mensageiro/metabolismo , RNA Interferente Pequeno , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Túbulos Seminíferos/citologia , Túbulos Seminíferos/crescimento & desenvolvimento , Espermatozoides/citologia , Espermatozoides/metabolismo
12.
Cir Esp ; 92(10): 676-81, 2014 Dec.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-25064517

RESUMO

BACKGROUND: Liver failure might be a cause of death after major hepatectomies. The ALPPS technique appears to be a promising strategy to avoid it, however no experimental studies supporting this procedure have been previously described. The aim was to develop an experimental model of ALPPS in rats. METHOD: Experimental. A total of 30 Sprague Dawley rats were used. To develop the ALPPS procedure, ligation of the left portal branch of the middle lobe (LM) was performed. This demarcates the left side (SILM) from the right side (SDLM); parenchyma transection was performed following the demarcated line. The animal's weight, volume and weight of both LM were analyzed. Sacrifice at 3, 7 and 14 days after the procedure (10 per group) was performed. RESULTS: No bleeding or ascites were observed during the postoperative period. The LM increased by 24.1, 86.9 and 120.4% at 3, 7 and 14 days. The SDLM increased by 34.4, 78.8 and 102.0% at 3, 7 and 14 days. The SILM decreased 42.6, 64.8, and 79.3% at day 3, 7 and 14 days respectively. CONCLUSION: The ALPPS procedure can be performed in rats, achieving the expected results. Comparison studies to 2 staged hepatectomy will be necessary.


Assuntos
Hepatectomia/métodos , Veia Porta/cirurgia , Fosfatase Alcalina , Animais , Proteínas Ligadas por GPI , Isoenzimas , Ligadura , Masculino , Modelos Animais , Modelos Teóricos , Ratos , Ratos Sprague-Dawley
13.
Lab Anim ; 57(4): 443-454, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36748321

RESUMO

The use of animals to gain knowledge and understanding of diseases needs to be reduced and refined. In the field of intestinal research, because of the complexity of the gut immune system, living models testing is mandatory. Based on the 3Rs (replacement, reduction and refinement) principles, we aimed to developed and apply the derived-intestinal surgical procedure described by Bishop and Koop (BK) in rats to refine experimental gastrointestinal procedures and reduce the number of animals used for research employing two models of intestinal inflammation: intestinal ischemia-reperfusion injury and chemical-induced colitis. Our results show the feasibility of the application of the BK technique in rodents, with good success after surgical procedure in both small and large intestine (100% survival, clinical recovery and weight regain). A considerable reduction in the use of the number of rats in both intestinal inflammation models (80% in case of intestinal ischemia-reperfusion damage and 66.6% in chemical-induced colitis in our experimental design) was achieved. Compared with conventional experimental models described by various research groups, we report excellent reproducibility of intestinal damage and functionality, survival rate and clinical status of the animals when BK is applied.


Assuntos
Colite , Traumatismo por Reperfusão , Animais , Ratos , Projetos de Pesquisa , Reprodutibilidade dos Testes , Animais de Laboratório , Inflamação
14.
Front Oncol ; 13: 1170502, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37324022

RESUMO

Background: The immune system plays a pivotal role in cancer progression. Interleukin 22 binding protein (IL-22BP), a natural antagonist of the cytokine interleukin 22 (IL-22) has been shown to control the progression of colorectal cancer (CRC). However, the role of IL-22BP in the process of metastasis formation remains unknown. Methods: We used two different murine in vivo metastasis models using the MC38 and LLC cancer cell lines and studied lung and liver metastasis formation after intracaecal or intrasplenic injection of cancer cells. Furthermore, IL22BP expression was measured in a clinical cohort of CRC patients and correlated with metastatic tumor stages. Results: Our data indicate that low levels of IL-22BP are associated with advanced (metastatic) tumor stages in colorectal cancer. Using two different murine in vivo models we show that IL-22BP indeed controls the progression of liver but not lung metastasis in mice. Conclusions: We here demonstrate a crucial role of IL-22BP in controlling metastasis progression. Thus, IL-22 might represent a future therapeutic target against the progression of metastatic CRC.

15.
Oncoimmunology ; 12(1): 2269634, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37876835

RESUMO

Metastasis is a cancer-related systemic disease and is responsible for the greatest mortality rate among cancer patients. Interestingly, the interaction between the immune system and cancer cells seems to play a key role in metastasis formation in the target organ. However, this complex network is only partially understood. We previously found that IL-22 produced by tissue resident iNKT17 cells promotes cancer cell extravasation, the early step of metastasis. Based on these data, we aimed here to decipher the role of IL-22 in the last step of metastasis formation. We found that IL-22 levels were increased in established metastatic sites in both human and mouse. We also found that Th22 cells were the key source of IL-22 in established metastasis sites, and that deletion of IL-22 in CD4+ T cells was protective in liver metastasis formation. Accordingly, the administration of a murine IL-22 neutralizing antibody in the establishment of metastasis formation significantly reduced the metastatic burden in a mouse model. Mechanistically, IL-22-producing Th22 cells promoted angiogenesis in established metastasis sites. In conclusion, our findings highlight that IL-22 is equally as important in contributing to metastasis formation at late metastatic stages, and thus, identify it as a novel therapeutic target in established metastasis.


Assuntos
Linfócitos T CD4-Positivos , Neoplasias Hepáticas , Humanos , Animais , Camundongos , Interleucinas , Interleucina 22
16.
Medicina (B Aires) ; 72(1): 3-9, 2012.
Artigo em Espanhol | MEDLINE | ID: mdl-22257448

RESUMO

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-a, 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).


Assuntos
Citocinas/biossíntese , Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Doadores Vivos , Traumatismo por Reperfusão/prevenção & controle , Sirolimo/uso terapêutico , Tacrolimo/uso terapêutico , Animais , Modelos Animais de Doenças , Terapia de Imunossupressão , Inflamação/metabolismo , Mediadores da Inflamação/metabolismo , Masculino , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologia , Condicionamento Pré-Transplante/métodos , Fator de Necrose Tumoral alfa/biossíntese
17.
J Trauma Acute Care Surg ; 92(2): 380-387, 2022 02 01.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-35081098

RESUMO

BACKGROUND: The hemodynamic maintenance of brain-dead donors will influence the quality of the organs procured for transplantation, including the intestine. Although norepinephrine (NE) and dopamine (DA) are commonly used to sustain mean arterial pressure in humans, there are no standardized protocols for their use during maintenance of brain-dead donors. Our aim was to compare the effects of each drug, in the intestinal graft quality using a rat brain-dead donation model. METHODS: Wistar rats (N = 17) underwent brain death (BD) for 2 hours with NE (NE group) or with DA (DA group) administration; the control group was mechanically ventilated for 2 hours without BD. Jejunum biopsies were obtained at the end of the maintenance period. Histological damage was evaluated using Park-Chiu scale. Villi/crypt ratio, mucosal thickness, Goblet cell count, and villi density were evaluated using ImageJ software (US National Institutes of Health, Bethesda, MD). Barrier damage was assessed by bacterial translocation culture counting on liver samples. The inflammatory status of the intestine was evaluated by CD3+ counting by immunohistochemistry and gene expression analysis of interleukin (IL)-6, IL-22, and CXCL10. RESULTS: Norepinephrine-treated donors had higher focal ischemic injury in the intestinal mucosa without a substantial modification of morphometrical parameters compared with DA-treated donors. CD3+ mucosal infiltration was greater in intestines procured from brain-dead donors, being highest in NE (p ˂ 0.001). Local inflammatory mediators were affected in BD: DA and NE groups showed a trend to lower expression of IL-22, whereas CXCL10 expression was higher in NE versus control group. Brain death promoted intestinal bacterial translocation, but the use of NE resulted in the highest bacterial counting in the liver (p ˂ 0.01). CONCLUSION: Our results favor the use of DA instead of NE as main vasoactive drug to manage BD-associated hemodynamic instability. Dopamine may contribute to improve the quality of the intestinal graft, by better preserving barrier function and lowering immune cell infiltration.


BACKGROUND: The hemodynamic maintenance of brain-dead donors will influence the quality of the organs procured for transplantation, including the intestine. Although norepinephrine (NE) and dopamine (DA) are commonly used to sustain mean arterial pressure in humans, there are no standardized protocols for their use during maintenance of brain-dead donors. Our aim was to compare the effects of each drug, in the intestinal graft quality using a rat brain-dead donation model. METHODS: Wistar rats (N = 17) underwent brain death (BD) for 2 hours with NE (NE group) or with DA (DA group) administration; the control group was mechanically ventilated for 2 hours without BD. Jejunum biopsies were obtained at the end of the maintenance period. Histological damage was evaluated using Park-Chiu scale. Villi/crypt ratio, mucosal thickness, Goblet cell count, and villi density were evaluated using ImageJ software (US National Institutes of Health, Bethesda, MD). Barrier damage was assessed by bacterial translocation culture counting on liver samples. The inflammatory status of the intestine was evaluated by CD3 + counting by immunohistochemistry and gene expression analysis of interleukin (IL)-6, IL-22, and CXCL10. RESULTS: Norepinephrine-treated donors had higher focal ischemic injury in the intestinal mucosa without a substantial modification of morphometrical parameters compared with DA-treated donors. CD3 + mucosal infiltration was greater in intestines procured from brain-dead donors, being highest in NE ( p ˂ 0.001). Local inflammatory mediators were affected in BD: DA and NE groups showed a trend to lower expression of IL-22, whereas CXCL10 expression was higher in NE versus control group. Brain death promoted intestinal bacterial translocation, but the use of NE resulted in the highest bacterial counting in the liver ( p ˂ 0.01). CONCLUSION: Our results favor the use of DA instead of NE as main vasoactive drug to manage BD-associated hemodynamic instability. Dopamine may contribute to improve the quality of the intestinal graft, by better preserving barrier function and lowering immune cell infiltration.


Assuntos
Morte Encefálica , Dopamina/farmacologia , Hemodinâmica/efeitos dos fármacos , Intestinos/irrigação sanguínea , Intestinos/transplante , Norepinefrina/farmacologia , Animais , Quimiocina CXCL10/metabolismo , Modelos Animais de Doenças , Interleucina-6/metabolismo , Interleucinas/metabolismo , Intestinos/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Interleucina 22
18.
Acta Gastroenterol Latinoam ; 41(2): 129-36, 2011 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-21894726

RESUMO

INTRODUCTION: The intestine is a highly sensitive tissue to ischemia-reperfusion (IR) injury that will early respond increasing its permeability. Later this response is translated in morphologic and histological changes that reveal the degree of damage. The heterotopic intestinal transplantation model in rats allows to evaluate the evolution of intestinal tissue injury after ischemia-reperfusion without affecting the long survival rate. OBJECTIVE: The aim of this paper is to establish a relationship between the ischemic reperfusion injury with the long-term survival METHODS: Ten intestinal transplants were analyzed in adult, Wistar, inbred, male rats. Light microscopical examination was performed on intestine graft: 1) immediately post-dissection, 2) at the end of cold isquemia, 3) 30 min, 4) 48hs and 5) 5 days post-transplant procedure, respectively. Biopsies were reported according to Park's classification and extension of staining using immunohistochemestry to malondialdehyde (MDA) products. RESULTS: The Park's classification indexes reported in samples were 1) 0,57 +/- 1,13 (N=10); 2) 2,71 +/- 1,25 (N=10); 3) 4,14 +/- 0,89 (N=10); 4) 1,0 +/- 0,81 (N=7); 5) 0 (N=7). The highest levels of immunohistochemical detection of MDA were observed thirty minutes post-reperfusion (extension of staining between 51% to 75%). Three animals died when they were sampled at 48 hours, and the biopsies had Park's classification > or = 4 at 30 minutes post-reperfusion and endotoxemic signology. CONCLUSIONS: The highest degree of mucosal damage was observed immediately post-reperfusion. At 48hs the graft tended to be normalized Failure to repair the immediately I-R injury signficantly affects the long term survival.


Assuntos
Intestinos/transplante , Traumatismo por Reperfusão/mortalidade , Animais , Modelos Animais de Doenças , Intestinos/irrigação sanguínea , Intestinos/patologia , Masculino , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologia , Índice de Gravidade de Doença , Taxa de Sobrevida , Fatores de Tempo
19.
Rev Bras Ter Intensiva ; 32(1): 58-65, 2020 Mar.
Artigo em Inglês, Português | MEDLINE | ID: mdl-32401991

RESUMO

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.


Assuntos
Adalimumab/uso terapêutico , Respiração Artificial/métodos , Lesão Pulmonar Induzida por Ventilação Mecânica/prevenção & controle , Animais , Modelos Animais de Doenças , Humanos , Distribuição Aleatória , Ratos , Ratos Wistar , Adulto Jovem
20.
Cir Cir ; 88(5): 554-561, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33064706

RESUMO

OBJECTIVE: The objective of the study was to show adipose tissue-derived mesenchymal stem cells (AD-MSCs) immunomodulatory effects in small bowel transplantation (SBTx). MATERIALS AND METHODS: Forty Wistar Han rats (age: 10-12 weeks): were allogenic receptor rats and were allotted in 2 groups. Control group: rats undergoing orthopic SBTx ; AD-MSCs group: rats undergoing orthotopic SBTx plus AD-MSCs. Male Lewis rats were allogeneic small bowel donors. Rejection was confirmed by histological study of the explanted intestine, enterocyte apoptosis was determined in crypts and the lamina propria of the small bowel. Cytokine concentration levels (enzyme-linked immunosorbent assay) (interleukin [IL]-4, IL-10, IL-12, IL-17, IL-21, IL-23, tumor necrosis factor-alpha, and transforming growth factor [TGF]-b1) and cell percentages (flow cytometry) (CD3+ CD4+, CD8+, CD4+/25+, CD8+/25+, CD4+/25+/Foxp3+, and CD8+/25+/Foxp3+) were assessed in peripheral blood preoperatively and after death. RESULTS: Treatment with AD-MSCs produced a significantly lower risk of rejection in the first 7 post-operative days (five rejection cases among 20 rats in the control group and only one case in the AD-MSCs group). Treg cells and TGFb1 levels showed a significant increase in the AD-MSCs group. CONCLUSIONS: The local implantation of AD-MSC in the anastomosis and the intestinal lumen can induce a regulatory immune response, by increasing the percentages of Treg cells and TGb-1 levels, leading to a lower risk of acute rejection by cell mediation, in the first 7 days of the intestinal transplant. We think that the implantation of AD-MSCs, in the anastomoses and in the lumen of the donor intestine, could give rise to a chimera of donor-recipient cells.


OBJETIVO: Mostrar el efecto inmunomodulador de las células madre mesenquimales (AD-MSCs) en el trasplante de intestino delgado (SBTx). MÉTODO: 40 ratas Wistar Han (edad: 10-12 semanas): grupo control (SBTx) y grupo AD-MSCs (SBTx + AD-MSCs implantadas en las anastomosis distal y proximal del intestino delgado y en la luz intestinal). El intestino delgado provino de ratas Lewis. El rechazo se confirmó histológicamente. Se estudió la apoptosis de los enterocitos en las criptas y en la lámina propia del intestino delgado. Se determinaron por ELISA las citocinas (IL-4, IL-10, IL-12, IL-17, IL-21, IL-23, TNF-α, TGF-b1) en sangre periférica y por citometría de flujo los porcentajes celulares (CD3+ CD4+, CD8+, CD4+/25+, CD8+/25+, CD4+/25+/Foxp3+, CD8+/25+/Foxp3+) en el preoperatorio y después de la muerte. RESULTADOS: El empleo de AD-MSCs se asoció a una disminución significativa del riesgo de rechazo en los primeros 7 días posoperatorios (cinco casos de rechazo de 20 ratas en el grupo control y un solo caso en el grupo AD-MSCs). Las células Treg y los valores de TGFb1 mostraron un incremento significativo en el grupo AD-MSCs. CONCLUSIONES: El implante local de AD-MSCs en las anastomosis del trasplante de intestino delgado podría disminuir el rechazo celular agudo. Pensamos que la implantación de AD-MSCs, en las anastomosis y en el lumen del intestino donante, podría dar lugar a un quimera de células donante-receptor.


Assuntos
Rejeição de Enxerto , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Animais , Rejeição de Enxerto/prevenção & controle , Masculino , Ratos , Ratos Endogâmicos Lew , Ratos Wistar , Linfócitos T Reguladores
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA