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1.
Medicina (Kaunas) ; 59(10)2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37893488

RESUMO

Gastritis cystica profunda (GCP) has been defined as a rare submucosal benign gastric lesion with cystic gland growth. Due to its unclear etiopathogenesis, this lesion is often misdiagnosed and mistaken for other gastric masses. Currently, a standardized treatment for GCP lesions is still missing. Here, we illustrate a case of a patient admitted to our general surgery department for melena and general discomfort. No history of peptic ulcer or gastric surgery was present. Upper GI endoscopy was performed, showing a distal gastric lesion with a small ulceration on the top. CT-scan and endoscopic ultrasound confirmed the presence of the lesion, compatible with a gastric stromal tumor, without showing any eventual metastasis. Surgical gastric resection was performed. Histological findings were diagnostic for GCP, with cistically ectasic submucosal glands, chronic inflammation, eosinophilic infiltration and foveal hyperplasia. GCP is a very exceptional cause of upper-GI bleeding with specific histological features. Its diagnosis as well as its therapy are challenging, resulting in several pitfalls. Even though it is a rare entity, GCP should always be considered in the differential diagnosis of gastric submucosal lesions.


Assuntos
Gastrite , Neoplasias Gastrointestinais , Neoplasias Gástricas , Humanos , Gastrite/etiologia , Doenças Raras/diagnóstico , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Neoplasias Gastrointestinais/complicações
2.
Transpl Int ; 35: 10640, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35859667

RESUMO

Artificial intelligence (AI) refers to computer algorithms used to complete tasks that usually require human intelligence. Typical examples include complex decision-making and- image or speech analysis. AI application in healthcare is rapidly evolving and it undoubtedly holds an enormous potential for the field of solid organ transplantation. In this review, we provide an overview of AI-based approaches in solid organ transplantation. Particularly, we identified four key areas of transplantation which could be facilitated by AI: organ allocation and donor-recipient pairing, transplant oncology, real-time immunosuppression regimes, and precision transplant pathology. The potential implementations are vast-from improved allocation algorithms, smart donor-recipient matching and dynamic adaptation of immunosuppression to automated analysis of transplant pathology. We are convinced that we are at the beginning of a new digital era in transplantation, and that AI has the potential to improve graft and patient survival. This manuscript provides a glimpse into how AI innovations could shape an exciting future for the transplantation community.


Assuntos
Inteligência Artificial , Transplante de Órgãos , Algoritmos , Previsões , Humanos , Oncologia
3.
Surg Endosc ; 36(11): 8261-8269, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35705755

RESUMO

BACKGROUND: Achieving proficiency in a surgical procedure is a milestone in the career of a trainee. We introduced a competency assessment tool for laparoscopic cholecystectomy in our residency program. Our aim was to assess the inter-rater reliability of this tool. METHODS: We included all laparoscopic cholecystectomies performed by residents under the supervision of board certified surgeons. All residents were assessed at the end of the procedure by the supervising surgeon (live reviewer) using our competency assessment tool. Video records of the same procedure were analyzed by two independent reviewers (reviewer A and B), who were blinded to the performing trainee's. The assessment had three parts: a laparoscopic cholecystectomy-specific assessment tool (LCAT), the objective structured assessment of technical skills (OSATS) and a 5-item visual analogue scale (VAS) to address the surgeon's autonomy in each part of the cholecystectomy. We compared the assessment scores of the live supervising surgeon and the video reviewers. RESULTS: We included 15 junior residents who performed 42 laparoscopic cholecystectomies. Scoring results from live and video reviewer were comparable except for the OSATS and VAS part. The score for OSATS by the live reviewer and reviewer B were 3.68 vs. 4.26 respectively (p = 0.04) and for VAS (5.17 vs. 4.63 respectively (p = 0.03). The same difference was found between reviewers A and B with OSATS score (3.75 vs. 4.26 respectively (p = 0.001)) and VAS (5.56 vs. 4.63 respectively; p = 0.004)). CONCLUSION: Our competency assessment tool for the evaluation of surgical skills specific to laparoscopic cholecystectomy has been shown to be objective and comparable in-between raters during live procedure or on video material.


Assuntos
Colecistectomia Laparoscópica , Internato e Residência , Humanos , Avaliação Educacional/métodos , Competência Clínica , Reprodutibilidade dos Testes
4.
Rev Med Suisse ; 18(786): 1210-1217, 2022 Jun 15.
Artigo em Francês | MEDLINE | ID: mdl-35703864

RESUMO

This article provides an overview of recent advances in the diagnosis and treatment of extrahepatic cholangiocarcinomas (EH-CCAs), focusing on the role of endoscopy, surgery, and transplantation. It reviews optimal evaluation and management of patients with EH-CCA, including a careful integration of clinical information, imaging studies, cytology and/or histology, as well as a coordinated multidisciplinary approach. It reviews additional therapy such as radio- or chemotherapy either in the neoadjuvant or adjuvant setting. Furthermore, it addresses palliative approaches as well as emerging targeted therapy and immunotherapy. EH-CCAs account for nearly 90% of biliary tract malignancies and present an ongoing challenge for hepatobiliary surgeons.


Cet article apporte une vision globale des avancées récentes dans le diagnostic et la prise en charge des cholangiocarcinomes extrahépatiques (CCA-EH), en décrivant les rôles respectifs de l'endoscopie, de la chirurgie et de la transplantation. L'évaluation et la prise en charge sont abordées en intégrant les informations cliniques, les différentes modalités d'imagerie, la cytologie et/ou la pathologie, à travers une approche multidisciplinaire. Nous abordons également les tendances épidémiologiques et les facteurs de risque nouvellement identifiés ainsi que l'apport de la radiochimiothérapie. L'approche palliative, tout comme les thérapies ciblées ou l'immunothérapie sont également discutées. Les CCA-EH représentent 90 % des cancers des voies biliaires et constituent un défi permanent pour les chirurgiens hépatobiliaires.


Assuntos
Neoplasias dos Ductos Biliares , Ductos Biliares Extra-Hepáticos , Colangiocarcinoma , Neoplasias dos Ductos Biliares/diagnóstico , Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/terapia , Ductos Biliares Extra-Hepáticos/patologia , Ductos Biliares Intra-Hepáticos/patologia , Ductos Biliares Intra-Hepáticos/cirurgia , Colangiocarcinoma/diagnóstico , Colangiocarcinoma/epidemiologia , Colangiocarcinoma/terapia , Endoscopia , Humanos
5.
Semin Liver Dis ; 41(2): 172-181, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33957694

RESUMO

For patients with early-stage hepatocellular carcinoma (HCC), liver transplantation offers the best chance of cure. Over the past two decades, selection criteria to determine eligibility for liver transplantation have been constantly refined but a fair allocation strategy of liver grafts to HCC patients remains challenging. In Europe, over a dozen transplantation networks apply different liver transplantation criteria for HCC patients. In this review, we explore and compare candidate selection and liver graft allocation strategies for patients with HCC with a European perspective and discuss the ethical and technical challenges involved. In addition, we suggest possible paths for future improvement such as transitioning from fixed selection and allocation criteria to a more flexible model of benefit, which includes criteria concerning the graft, response to treatment, the biology of the tumor, and other relevant recipient factors.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Transplante de Fígado , Carcinoma Hepatocelular/cirurgia , Humanos , Neoplasias Hepáticas/cirurgia , Transplante de Fígado/efeitos adversos , Seleção de Pacientes
6.
Neurobiol Learn Mem ; 178: 107362, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33333316

RESUMO

Trauma patients treated with ketamine during emergency care present aggravated early post- traumatic stress reaction which is highly predictive of post-traumatic stress disorder (PTSD) development and severity. The use of ketamine in the acute trauma phase may directly or indirectly interfere with neural processes of memory consolidation of the traumatic event, thus leading to the formation of maladaptive memories, a hallmark symptom of PTSD. We have recently shown that ketamine anesthesia, immediately after a traumatic event, enhances memory consolidation and leads to long-lasting alterations of social behavior in rats. Based on the evidence that ketamine induces a robust central and peripheral adrenergic/noradrenergic potentiation and that activation of this system is essential for the formation of memory for stressful events, we explored the possibility that the strong sympathomimetic action of ketamine might underlie its memory enhancing effects. We found that rats given immediate, but not delayed, post-training ketamine anesthesia (125 mg/kg) presented enhanced 48-h memory retention in an inhibitory avoidance task and that these effects were blocked by adrenal medullectomy, lesions of the locus coeruleus, systemic or intra-basolateral amygdala ß-adrenergic receptor antagonism. Thus, the memory enhancing effects of ketamine anesthesia are time-dependent and mediated by a combined peripheral-central sympathomimetic action. We elucidated a mechanism by which ketamine exacerbates acute post-traumatic reaction, possibly leading to development of PTSD symptomatology later in life. These findings will help guide for a better management of sedation/anesthesia in emergency care to promote the prophylaxis and reduce the risk of developing trauma-related disorders in trauma victims.


Assuntos
Neurônios Adrenérgicos/efeitos dos fármacos , Anestésicos Dissociativos/administração & dosagem , Complexo Nuclear Basolateral da Amígdala/efeitos dos fármacos , Medo/efeitos dos fármacos , Ketamina/administração & dosagem , Consolidação da Memória/efeitos dos fármacos , Neurônios Adrenérgicos/metabolismo , Animais , Nível de Alerta/efeitos dos fármacos , Aprendizagem da Esquiva/efeitos dos fármacos , Complexo Nuclear Basolateral da Amígdala/metabolismo , Ratos , Transtornos de Estresse Pós-Traumáticos/metabolismo
7.
Rev Med Suisse ; 17(743): 1167-1171, 2021 Jun 16.
Artigo em Francês | MEDLINE | ID: mdl-34133094

RESUMO

Total pancreatectomy is a procedure primarily performed for chronic pancreatitis refractory to conservative therapy. It may nevertheless be indicated in the event of a malignant tumor, either as a treatment for a surgical complication or as a prevention of anastomotic leakage. If possible, islet auto-transplantation should be combined with total pancreatectomy for benign disease, in order to prevent a severe diabetes. Until recently, malignant disease was considered an absolute contraindication to islet auto-transplantation. A recent series from Milan showed promising oncological results in auto-transplantation for malignant disease, opening up new perspectives for total pancreatectomy for cancer.


La pancréatectomie totale est une procédure principalement effectuée pour une pancréatite chronique réfractaire au traitement conservateur. Elle peut néanmoins être indiquée en cas de tumeur maligne, soit comme traitement d'une complication chirurgicale, soit en prévention de fuite anastomotique. Dans la mesure du possible, une autogreffe d'îlots de Langerhans devrait être associée à une pancréatectomie totale pour maladie bénigne, dans le but de prévenir un diabète pancréatoprive. Jusqu'à récemment, une pathologie maligne était considérée comme une contre-indication absolue à une autogreffe d'îlots. Une série récente de Milan a montré des résultats oncologiques prometteurs en cas d'autogreffe pour pathologies malignes, ouvrant de nouvelles perspectives à la pancréatectomie totale pour cancer.


Assuntos
Diabetes Mellitus , Transplante das Ilhotas Pancreáticas , Pancreatite Crônica , Humanos , Pancreatectomia , Pancreatite Crônica/cirurgia , Transplante Autólogo , Resultado do Tratamento
8.
Transpl Int ; 33(6): 675-688, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32003082

RESUMO

Intraportal islet transplantation is plagued by an acute destruction of transplanted islets. Amongst the first responders, NK cells and macrophages harbour an activating receptor, NKG2D, recognizing ligands expressed by stressed cells. We aimed to determine whether islet NKG2D ligand expression increases with culture time, and to analyse the impact of antibody-induced NKG2D blockade in islet transplantation. NKG2D-ligand expression was analysed in rat and human islets. Syngeneic marginal mass intraportal islet transplantations were performed in rats: control group, recipients transplanted with NKG2D-recombinant-treated islets (recombinant group), and recipients treated with a mouse anti-rat anti-NKG2D antibody and transplanted with recombinant-treated islets (antibody-recombinant group). Islets demonstrated increased gene expression of NKG2D ligands with culture time. Blockade of NKG2D on NK cells decreased in vitro cytotoxicity against islets. Recipients from the control and recombinant groups showed similar metabolic results; conversely, treatment with the antibody resulted in lower diabetes reversal. The antibody depleted circulating and liver NK cells in recipients, who displayed increased macrophage infiltration of recipient origin around the transplanted islets. In vitro blockade of NKG2D ligands had no impact on early graft function. Systemic treatment of recipients with an anti-NKG2D antibody was deleterious to the islet graft, possibly through an antibody-dependent cell-mediated cytotoxicity reaction.


Assuntos
Diabetes Mellitus , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas , Animais , Sobrevivência de Enxerto , Fígado , Camundongos , Subfamília K de Receptores Semelhantes a Lectina de Células NK , Ratos
9.
BMC Cancer ; 19(1): 922, 2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31521134

RESUMO

BACKGROUND: Pancreatic adenocarcinoma is a high-mortality neoplasm with a documented 5-years-overall survival around 5%. In the last decades, a real breakthrough in the treatment of the disease has not been achieved. Here we propose a prospective, phase II, multicentre, single-arm study aiming to assess the efficacy and the feasibility of a therapeutic protocol combining chemotherapy, carbon ion therapy and surgery for resectable and borderline resectable pancreatic adenocarcinoma. METHOD: The purpose of this trial (PIOPPO Protocol) is to assess the efficacy and the feasibility of 3 cycles of FOLFIRINOX neoadjuvant chemotherapy followed by a short-course of carbon ion radiotherapy (CIRT) for resectable or borderline resectable pancreatic adenocarcinoma patients. Primary outcome of this study is the assessment of local progression free survival (L-PFS). The calculation of sample size is based on the analysis of the primary endpoint "progression free survival" according to Fleming's Procedure. DISCUSSION: Very preliminary results provide initial evidence of the feasibility of the combined chemotherapy and CIRT in the neoadjuvant setting for resectable or borderline resectable pancreatic cancer. Completion of the accrual and long term results are awaited to see if this combination of treatment is advisable and will provide the expected benefits. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03822936 registered on January 2019.


Assuntos
Adenocarcinoma/patologia , Adenocarcinoma/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos Clínicos , Radioterapia com Íons Pesados , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Terapia Combinada , Feminino , Radioterapia com Íons Pesados/efeitos adversos , Radioterapia com Íons Pesados/métodos , Humanos , Masculino , Estadiamento de Neoplasias , Cuidados Pré-Operatórios
11.
Transpl Int ; 32(3): 323-333, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30318858

RESUMO

Remote ischaemic preconditioning (RIPC), which is the intermittent interruption of blood flow to a site distant from the target organ, is known to improve solid organ resistance to ischaemia-reperfusion injury. This procedure could be of interest in islet transplantation to mitigate hypoxia-related loss of islet mass after isolation and transplantation. Islets isolated from control or RIPC donors were analyzed for yield, metabolic activity, gene expression and high mobility group box-1 (HMGB1) content. Syngeneic marginal mass transplantation was performed in four streptozotocin-induced diabetic groups: control, RIPC in donor only, RIPC in recipient only, and RIPC in donor and recipient. Islets isolated from RIPC donors had an increased yield of 20% after 24 h of culture compared to control donors (P = 0.007), linked to less cell death (P = 0.08), decreased expression of hypoxia-related genes (Hif1a P = 0.04; IRP94 P = 0.008), and increased intra-cellular (P = 0.04) and nuclear HMGB1. The use of RIPC in recipients only did not allow for reversal of diabetes, with increased serum HMGB1 at day 1; the three other groups demonstrated significantly better outcomes. Performing RIPC in the donors increases islet yield and resistance to hypoxia. Validation is needed, but this strategy could help to decrease the number of donors per islet recipient.


Assuntos
Precondicionamento Isquêmico , Transplante das Ilhotas Pancreáticas/métodos , Animais , Ensaio de Imunoadsorção Enzimática , Proteína HMGB1/sangue , Proteína HMGB1/fisiologia , Insulina/metabolismo , Fígado/fisiopatologia , Modelos Animais , Ratos , Ratos Endogâmicos Lew , Doadores de Tecidos
12.
Mediators Inflamm ; 2019: 8971036, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31885502

RESUMO

Animal models are widely used to replicate human intra-abdominal infections. Different methodologies have been described and proposed in the scientific literature, including injection and surgical models. The aim of this review is to recapitulate the advantages and disadvantages of each method to help choose the most appropriate model for individual experimental purposes.


Assuntos
Modelos Animais de Doenças , Sepse , Animais , Humanos , Lipopolissacarídeos/toxicidade , Peritonite/patologia
13.
J Hepatol ; 69(5): 1025-1036, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30031887

RESUMO

BACKGROUND & AIMS: A major limitation in the field of liver transplantation is the shortage of transplantable organs. Chimeric animals carrying human tissue have the potential to solve this problem. However, currently available chimeric organs retain a high level of xenogeneic cells, and the transplantation of impure organs needs to be tested. METHODS: We created chimeric livers by injecting Lewis rat hepatocytes into C57Bl/6Fah-/-Rag2-/-Il2rg-/- mice, and further transplanted them into newly weaned Lewis rats (45 ±â€¯3 g) with or without suboptimal immunosuppression (tacrolimus 0.6 mg/kg/day for 56 or 112 days). Control donors included wild-type C57Bl/6 mice (xenogeneic) and Lewis rats (syngeneic). RESULTS: Without immunosuppression, recipients of chimeric livers experienced acute rejection, and died within 8 to 11 days. With immunosuppression, they all survived for >112 days with normal weight gain compared to syngeneic controls, while all xenogeneic controls died within 98 days due to rejection with Banff scores >6 (p = 0.0014). The chimeric grafts underwent post-transplant remodelling, growing by 670% on average. Rat hepatocytes fully replaced mouse hepatocytes starting from day 56 (absence of detectable mouse serum albumin, histological clearance of mouse hepatocytes). In addition, rat albumin levels reached those of syngeneic recipients. Four months after transplantation of chimeric livers, we observed the development of diffuse mature rat bile ducts through transdifferentiation of hepatocytes (up to 72% of cholangiocytes), and patchy areas of portal endothelium originating from the host (seen in one out of five recipients). CONCLUSIONS: Taken together, these data demonstrate the efficacy of transplanting rat-to-mouse chimeric livers into rats, with a high potential for post-transplant recipient-oriented graft remodelling. Validation in a large animal model is still needed. LAY SUMMARY: Chimeric animals are composed of cells from different species. Chimeric animals carrying human tissue have the potential to increase the availability of transplantable organs. We transplanted rat-to-mouse liver grafts into newly weaned rats. The chimeric grafts underwent post-transplant remodelling with rat hepatocytes replacing all mouse hepatocytes within 56 days. In addition, we observed the post-transplant development of diffuse mature rat bile ducts through the transformation of hepatocytes, and patchy areas of portal endothelium originating from the host. These data demonstrate the efficacy of transplanting rat-to-mouse chimeric livers into rats, with a high potential for post-transplant graft remodelling.


Assuntos
Transplante de Fígado/métodos , Transplante Heterólogo/métodos , Animais , Quimera , Feminino , Rejeição de Enxerto , Hepatócitos/transplante , Imunossupressores/uso terapêutico , Transplante de Fígado/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Endogâmicos Lew , Ratos Wistar , Transplante Heterólogo/efeitos adversos
14.
Ann Surg ; 267(6): 1191-1201, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-28252516

RESUMO

OBJECTIVE: The purpose of this study was to assess whether perfusion-decellularization technology could be applied to facial grafts. BACKGROUND: Facial allotransplantation remains an experimental procedure. Regenerative medicine techniques allow fabrication of transplantable organs from an individual's own cells, which are seeded into extracellular matrix (ECM) scaffolds from animal or human organs. Therefore, we hypothesized that ECM scaffolds also can be created from facial subunits. We explored the use of the porcine ear as a clinically relevant face subunit model to develop regenerative medicine-related platforms for facial bioengineering. METHODS: Porcine ear grafts were decellularized and histologic, immunologic, and cell culture studies done to determine whether scaffolds retained their 3D framework and molecular content; were biocompatible in vitro and in vivo, and triggered an anti-MHC immune response from the host. RESULTS: The cellular compartment of the porcine ear was completely removed except for a few cartilaginous cells, leaving behind an acellular ECM scaffold; this scaffold retained its complex 3D architecture and biochemical components. The framework of the vascular tree was intact at all hierarchical levels and sustained a physiologically relevant blood pressure when implanted in vivo. Scaffolds were biocompatible in vitro and in vivo, and elicited no MHC immune response from the host. Cells from different types remained viable and could even differentiate at the scale of a whole-ear scaffold. CONCLUSIONS: Acellular scaffolds were produced from the porcine ear, and may be a valuable platform to treat facial deformities using regenerative medicine approaches.


Assuntos
Derme Acelular , Matriz Extracelular , Transplante de Face/métodos , Engenharia Tecidual/métodos , Alicerces Teciduais , Animais , Materiais Biocompatíveis , Orelha , Projetos Piloto , Suínos
16.
J Cell Mol Med ; 21(12): 3381-3393, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28639291

RESUMO

Kidney donation after circulatory death (DCD) is a less than ideal option to meet organ shortages. Hypothermic machine perfusion (HMP) with Belzer solution (BS) improves the viability of DCD kidneys, although the graft clinical course remains critical. Mesenchymal stromal cells (MSC) promote tissue repair by releasing extracellular vesicles (EV). We evaluated whether delivering MSC-/MSC-derived EV during HMP protects rat DCD kidneys from ischaemic injury and investigated the underlying pathogenic mechanisms. Warm ischaemic isolated kidneys were cold-perfused (4 hrs) with BS, BS supplemented with MSC or EV. Renal damage was evaluated by histology and renal gene expression by microarray analysis, RT-PCR. Malondialdehyde, lactate, LDH, glucose and pyruvate were measured in the effluent fluid. MSC-/EV-treated kidneys showed significantly less global ischaemic damage. In the MSC/EV groups, there was up-regulation of three genes encoding enzymes known to improve cell energy metabolism and three genes encoding proteins involved in ion membrane transport. In the effluent fluid, lactate, LDH, MDA and glucose were significantly lower and pyruvate higher in MSC/EV kidneys as compared with BS, suggesting the larger use of energy substrates by MSC/EV kidneys. The addition of MSC/EV to BS during HMP protects the kidney from ischaemic injury by preserving the enzymatic machinery essential for cell viability and protects the kidney from reperfusion damage.


Assuntos
Vesículas Extracelulares/transplante , Transplante de Rim , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Preservação de Órgãos/métodos , Perfusão/métodos , Traumatismo por Reperfusão/prevenção & controle , Adenosina , Alopurinol , Animais , Biomarcadores/metabolismo , Metabolismo Energético/genética , Vesículas Extracelulares/química , Expressão Gênica , Perfilação da Expressão Gênica , Glucose/metabolismo , Glutationa , Insulina , Transporte de Íons/genética , Rim/metabolismo , Rim/cirurgia , L-Lactato Desidrogenase/metabolismo , Ácido Láctico/metabolismo , Malondialdeído/metabolismo , Soluções para Preservação de Órgãos , Ácido Pirúvico/metabolismo , Rafinose , Ratos , Ratos Endogâmicos F344 , Ratos Transgênicos , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/metabolismo
17.
Xenotransplantation ; 24(4)2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28736957

RESUMO

Blastocyst complementation refers to the injection of cells into a blastocyst. The technology allows for the creation of chimeric animals, which have the potential to be used as an unlimited source of organ donors. Pluripotent stem cells could be generated from a patient in need of a transplantation and injected into a large animal blastocyst (potentially of a pig), leading to the creation of organ(s) allowing immunosuppression-free transplantation. Various chimera combinations have already been generated, but one of the most recent steps leads to the creation of human-pig chimeras, which could be studied at an embryo stage. Although still far from clinical reality, the potential application is almost unlimited. The present review illustrates the historical steps of intra- and interspecific blastocyst complementation in rodents and large animals, specifically looking at its potential for generation of organ grafts. We also speculate on how it could change transplant indications, on its economic impact, and on the linked ethical concerns.


Assuntos
Blastocisto/metabolismo , Quimera/metabolismo , Células-Tronco Pluripotentes/citologia , Transplante Heterólogo , Animais , Diferenciação Celular/fisiologia , Proteínas do Sistema Complemento/metabolismo , Humanos , Suínos
18.
Proc Natl Acad Sci U S A ; 111(51): 18333-8, 2014 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-25489086

RESUMO

Previous studies have provided extensive evidence that administration of cannabinoid drugs after training modulates the consolidation of memory for an aversive experience. The present experiments investigated whether the memory consolidation is regulated by endogenously released cannabinoids. The experiments first examined whether the endocannabinoids anandamide (AEA) and 2-arachidonoyl glycerol (2-AG) are released by aversive training. Inhibitory avoidance training with higher footshock intensity produced increased levels of AEA in the amygdala, hippocampus, and medial prefrontal cortex (mPFC) shortly after training in comparison with levels assessed in rats trained with lower footshock intensity or unshocked controls exposed only to the training apparatus. In contrast, 2-AG levels were not significantly elevated. The additional finding that posttraining infusions of the fatty acid amide hydrolase (FAAH) inhibitor URB597, which selectively increases AEA levels at active synapses, administered into the basolateral complex of the amygdala (BLA), hippocampus, or mPFC enhanced memory strongly suggests that the endogenously released AEA modulates memory consolidation. Moreover, in support of the view that this emotional training-associated increase in endocannabinoid neurotransmission, and its effects on memory enhancement, depends on the integrity of functional interactions between these different brain regions, we found that disruption of BLA activity blocked the training-induced increases in AEA levels as well as the memory enhancement produced by URB597 administered into the hippocampus or mPFC. Thus, the findings provide evidence that emotionally arousing training increases AEA levels within prefrontal-limbic circuits and strongly suggest that this cannabinoid activation regulates emotional arousal effects on memory consolidation.


Assuntos
Ácidos Araquidônicos/metabolismo , Emoções , Endocanabinoides/metabolismo , Sistema Límbico/fisiologia , Memória , Alcamidas Poli-Insaturadas/metabolismo , Córtex Pré-Frontal/fisiologia , Amidoidrolases/antagonistas & inibidores , Animais , Aprendizagem da Esquiva , Benzamidas/farmacologia , Carbamatos/farmacologia , Glicerídeos/metabolismo , Sistema Límbico/enzimologia , Córtex Pré-Frontal/enzimologia , Ratos , Receptor CB1 de Canabinoide/agonistas
19.
Ann Surg ; 264(1): 169-79, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26649588

RESUMO

OBJECTIVES: Our study aims at producing acellular extracellular matrix scaffolds from the human pancreas (hpaECMs) as a first critical step toward the production of a new-generation, fully human-derived bioartificial endocrine pancreas. In this bioartificial endocrine pancreas, the hardware will be represented by hpaECMs, whereas the software will consist in the cellular compartment generated from patient's own cells. BACKGROUND: Extracellular matrix (ECM)-based scaffolds obtained through the decellularization of native organs have become the favored platform in the field of complex organ bioengineering. However, the paradigm is now switching from the porcine to the human model. METHODS: To achieve our goal, human pancreata were decellularized with Triton-based solution and thoroughly characterized. Primary endpoints were complete cell and DNA clearance, preservation of ECM components, growth factors and stiffness, ability to induce angiogenesis, conservation of the framework of the innate vasculature, and immunogenicity. Secondary endpoint was hpaECMs' ability to sustain growth and function of human islet and human primary pancreatic endothelial cells. RESULTS: Results show that hpaECMs can be successfully and consistently produced from human pancreata and maintain their innate molecular and spatial framework and stiffness, and vital growth factors. Importantly, hpaECMs inhibit human naïve CD4 T-cell expansion in response to polyclonal stimuli by inducing their apoptosis and promoting their conversion into regulatory T cells. hpaECMs are cytocompatible and supportive of representative pancreatic cell types. DISCUSSION: We, therefore, conclude that hpaECMs has the potential to become an ideal platform for investigations aiming at the manufacturing of a regenerative medicine-inspired bioartificial endocrine pancreas.


Assuntos
Matriz Extracelular/metabolismo , Pâncreas , Engenharia Tecidual , Alicerces Teciduais , Humanos , Ilhotas Pancreáticas/metabolismo , Organogênese , Pâncreas/metabolismo , Regeneração , Engenharia Tecidual/métodos
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