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1.
Chembiochem ; 22(3): 516-522, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-32974990

RESUMO

Indoleamine-2,3-dioxygenase 1 (IDO1) is a heme-containing enzyme that catalyzes the rate-limiting step in the kynurenine pathway of tryptophan (TRP) metabolism. As it is an inflammation-induced immunoregulatory enzyme, pharmacological inhibition of IDO1 activity is currently being pursued as a potential therapeutic tool for the treatment of cancer and other disease states. As such, a detailed understanding of the mechanism of action of IDO1 inhibitors with various mechanisms of inhibition is of great interest. Comparison of an apo-form-binding IDO1 inhibitor (GSK5628) to the heme-coordinating compound, epacadostat (Incyte), allows us to explore the details of the apo-binding inhibition of IDO1. Herein, we demonstrate that GSK5628 inhibits IDO1 by competing with heme for binding to a heme-free conformation of the enzyme (apo-IDO1), whereas epacadostat coordinates its binding with the iron atom of the IDO1 heme cofactor. Comparison of these two compounds in cellular systems reveals a long-lasting inhibitory effect of GSK5628, previously undescribed for other known IDO1 inhibitors. Detailed characterization of this apo-binding mechanism for IDO1 inhibition might help design superior inhibitors or could confer a unique competitive advantage over other IDO1 inhibitors vis-à-vis specificity and pharmacokinetic parameters.


Assuntos
Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Inibidores Enzimáticos/química , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Conformação Molecular
2.
Liver Transpl ; 27(4): 548-557, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33098277

RESUMO

Liver transplantation (LT) using allografts from hepatitis C virus (HCV)-viremic/nucleic acid testing-positive donors' (DNAT+) organs into HCV-aviremic recipients (rHCV-) has been limited owing to nearly universal HCV transmission and concerns regarding availability, safety, and efficacy post-LT with direct-acting antiviral (DAA) therapy. We report our experience of LT using DNAT+ organs into rHCV- as a routine standard of care. Following verification of DAA access, absence of critical drug-drug interactions (DDIs) with DAAs, and informed consent, allocated DNAT+ organs were offered to patients on the waiting list for LT irrespective of recipient HCV status. Between June 2018 and December 2019, 292/339 rHCV- received an LT. Forty-seven patients were excluded from analysis because of recipient HCV viremia, refusal to receive DNAT+ organs, or inability to receive DAA therapy post-LT. Of these 292 patients, 61 rHCV- received DNAT+ livers (study group), and 231 rHCV- received DNAT- (aviremic donors [nuclear acid test-negative donors]) livers (control group). Recipient and donor characteristics as well as 1-year post-LT patient and graft survival were similar between groups. In the study group, 4 patients died, and 1 patient required retransplantation within the first year post-LT (all unrelated to HCV); 56 patients received DAA therapy, with a median time from LT to the start of DAA treatment of 66.9 days (interquartile range [IQR], 36-68.5), and 51 patients completed DAA treatment, all achieving sustained virologic response for 12 or more weeks (SVR-12) (1 patient required retreatment owing to relapse following initial DAA therapy). No patients had evidence of fibrosing cholestatic hepatitis or extrahepatic manifestations of HCV. This report indicates that transplantation of DNAT+ livers into rHCV- and subsequent DAA therapy is associated with clinical outcomes comparable to those achieved with DNAT- allografts.


Assuntos
Hepatite C Crônica , Hepatite C , Transplante de Fígado , Antivirais/uso terapêutico , Hepacivirus , Hepatite C/tratamento farmacológico , Hepatite C Crônica/tratamento farmacológico , Humanos , Transplante de Fígado/efeitos adversos , Padrão de Cuidado , Doadores de Tecidos , Viremia/tratamento farmacológico
3.
Liver Transpl ; 23(3): 299-304, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28026108

RESUMO

Liver transplantation (LT) offers the best chance of survival in selected patients with hepatocellular carcinoma (HCC). Wait-list mortality or dropout due to tumor progression can be significant, and therefore, timely transplantation is critical. Liver grafts discarded by outside organ procurement organizations are a potential source of grafts for low Model for End-Stage Liver Disease tumor patients. The primary aim of this study was to assess the disease-free and overall survival of patients with HCC transplanted with imported liver grafts (ILGs). Review of all patients transplanted for HCC between June 2005 and December 2014 was performed. Data on demographics, survival, and HCC recurrence were analyzed. During this time period, 59 out of 190 (31%) recipients with HCC received ILG. Of these 59 grafts, 54 were imported from within the region and 5 were from national offers (outside the region). The mean cold ischemia time for local liver grafts (LLGs) was 4.1 ± 1.5 hours versus 5.1 ± 1.4 hours for ILG (P < 0.001). The 1-, 3-, and 5-year patient survival was 90%, 85%, and 83% and 85%, 80%, and 79% for LLG and ILG (P = 0.08), respectively. The observed disease recurrence rate for both LLG and ILG recipients was equivalent. The median wait-list time for HCC recipients was 43 days (range, 2-1167 days). In conclusion, with careful graft assessment, the use of ILGs results in comparable outcomes following LT and no increased risk of HCC recurrence. Use of ILGs maximizes the donor pool and results in a higher rate of transplantation for HCC recipients. Liver Transplantation 23 299-304 2017 AASLD.


Assuntos
Carcinoma Hepatocelular/mortalidade , Doença Hepática Terminal/mortalidade , Neoplasias Hepáticas/mortalidade , Transplante de Fígado/estatística & dados numéricos , Recidiva Local de Neoplasia/epidemiologia , Obtenção de Tecidos e Órgãos/métodos , Adulto , Idoso , Aloenxertos/patologia , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Isquemia Fria/efeitos adversos , Seleção do Doador/métodos , Doença Hepática Terminal/etiologia , Doença Hepática Terminal/cirurgia , Feminino , Humanos , Estimativa de Kaplan-Meier , Fígado/patologia , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Seleção de Pacientes , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Estados Unidos/epidemiologia , Listas de Espera/mortalidade
4.
J Vasc Surg ; 66(5): 1488-1496, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28697937

RESUMO

BACKGROUND: Hepatic artery stenosis (HAS) after liver transplantation can progress to hepatic artery thrombosis (HAT) and a subsequent 30% to 50% risk of graft loss. Although endovascular treatment of severe HAS after liver transplantation has emerged as the dominant method of treatment, the potential risks of these interventions are poorly described. METHODS: A retrospective review of all endovascular interventions for HAS after liver transplantation between August 2009 and March 2016 was performed at a single institution, which has the largest volume of liver transplants in the United States. Severe HAS was identified by routine surveillance duplex ultrasound imaging (peak systolic velocity >400 cm/s, resistive index <0.5, and presence of tardus parvus waveforms). RESULTS: In 1129 liver transplant recipients during the study period, 106 angiograms were performed in 79 patients (6.9%) for severe de novo or recurrent HAS. Interventions were performed in 99 of 106 cases (93.4%) with percutaneous transluminal angioplasty alone (34 of 99) or with stent placement (65 of 99). Immediate technical success was 91%. Major complications occurred in eight of 106 cases (7.5%), consisting of target vessel dissection (5 of 8) and rupture (3 of 8). Successful endovascular treatment was possible in six of the eight patients (75%). Ruptures were treated with the use of a covered coronary balloon-expandable stent graft or balloon tamponade. Dissections were treated with placement of bare-metal or drug-eluting stents. No open surgical intervention was required to manage any of these complications. With a median of follow-up of 22 months, four of eight patients (50%) with a major complication progressed to HAT compared with one of 71 patients (1.4%) undergoing a hepatic intervention without a major complication (P < .001). One patient required retransplantation. Severe vessel tortuosity was present in 75% (6 of 8) of interventions with a major complication compared with 34.6% (34 of 98) in those without (P = .05). In the complication cohort, 37.5% (3 of 8) of the patients had received a second liver transplant before intervention compared with 12.6% (9 of 71) of the patients in the noncomplication cohort (P = .097). CONCLUSIONS: Although endovascular treatment of HAS is safe and effective in most patients, target vessel injury is possible. Severe tortuosity of the hepatic artery and prior retransplantation were associated with a twofold to threefold increased risk of a major complication. Acute vessel injury can be managed successfully using endovascular techniques, but these patients have a significant risk of subsequent HAT and need close surveillance.


Assuntos
Arteriopatias Oclusivas/terapia , Procedimentos Endovasculares/efeitos adversos , Artéria Hepática/lesões , Artéria Hepática/transplante , Transplante de Fígado/efeitos adversos , Lesões do Sistema Vascular/etiologia , Adulto , Angiografia , Arteriopatias Oclusivas/diagnóstico por imagem , Arteriopatias Oclusivas/etiologia , Arteriopatias Oclusivas/fisiopatologia , Criança , Constrição Patológica , Procedimentos Endovasculares/instrumentação , Feminino , Artéria Hepática/diagnóstico por imagem , Humanos , Louisiana , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Fatores de Risco , Stents , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia Doppler Dupla , Grau de Desobstrução Vascular , Lesões do Sistema Vascular/diagnóstico por imagem , Lesões do Sistema Vascular/terapia
5.
Clin Transplant ; 31(11)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28856732

RESUMO

INTRODUCTION: Early allograft dysfunction (EAD) is a well-defined clinical syndrome that reflects overall graft function within the first week after transplant. The aim of this study was to further refine the definition for EAD. METHOD: In this study, 1124 patients were included for analysis. Logistic regression was performed to identify markers of liver injury associated with 6-month patient and graft failure. RESULTS: Recursive partitioning identified cut-points for ALT/AST > 3000/6000 IU/dL observed within first week, with bilirubin ≥ 10 mg/dL and INR ≥ 1.6 on postoperative day 7 for the revised EAD model. The incidence of updated EAD was 15% (164/1124). Multivariable analysis identified eight risk factors associated with EAD: % macrosteatosis, donor location, donor weight, nonheart beating donors, type of organ transplanted, recipient-associated hepatocellular carcinoma, severity of postreperfusion syndrome, and the amount of transfused fresh frozen plasma. In the presence of EAD, the incidence of post-transplant renal replacement therapy and dialysis dependence increases. There was a significant association of the presence of EAD with 6-month mortality (12% vs 3%) and 6-month graft failure (8% vs 1%). CONCLUSION: Higher AST/ALT level needed as cutoff in comparison with the old EAD definition.


Assuntos
Biomarcadores/análise , Transplante de Fígado/efeitos adversos , Complicações Pós-Operatórias , Disfunção Primária do Enxerto/diagnóstico , Índice de Gravidade de Doença , Doadores de Tecidos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Aloenxertos , Criança , Pré-Escolar , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Disfunção Primária do Enxerto/etiologia , Fatores de Risco , Fatores de Tempo , Adulto Jovem
6.
J Cardiothorac Vasc Anesth ; 31(2): 575-581, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27745797

RESUMO

OBJECTIVES: The purpose of this study was to compare the agreement between two heparin assays, Hepcon HMS plus/Kaolin-ACT and Anti-Xa, and their predictive power in detecting circulating heparin levels post-reperfusion of the liver graft when compared with thromboelastogram (TEG) r time ratio in patients undergoing orthotopic liver transplantation (OLT). DESIGN: Prospective, observational cohort study design. SETTING: Single center, university hospital. PARTICIPANTS: Thirty-eight consecutive adults who had undergone liver transplant. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Paired arterial blood samples were collected before surgical incision, 5 minutes after administration of an average dose of 2,054±771 units of intravenous unfractionated heparin before caval cross-clamping, 5 minutes after portal reperfusion, 5 minutes after hepatic artery reperfusion, and 1 hour after hepatic artery reperfusion. The observations that heparin assay measurements were within the predetermined limits of agreement, strongly suggested the two heparin assays (Hepcon HMS plus and Anti-Xa assay) are interchangeable during prophylactic heparin dose therapy during OLT. Post-reperfusion, receiver operating characteristic curve analysis revealed high accuracy in measuring circulating heparin levels with both Anti-Xa and Hepcon HMS assays when compared with the TEG r time ratio assay. CONCLUSIONS: The point-of-care Hepcon HMS plus/Kaolin-ACT (activated clotting time) assay appeared to be a reliable alternative to the more expensive and laboratory-required Anti-Xa assay in monitoring the response to intravenous heparin in patients undergoing OLT.


Assuntos
Anticoagulantes/administração & dosagem , Inibidores do Fator Xa/administração & dosagem , Heparina/administração & dosagem , Transplante de Fígado/métodos , Preparações de Plantas/administração & dosagem , Profilaxia Pré-Exposição/métodos , Adulto , Idoso , Anticoagulantes/sangue , Testes de Coagulação Sanguínea/métodos , Estudos de Coortes , Feminino , Heparina/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Tromboelastografia/métodos
7.
Hepatobiliary Pancreat Dis Int ; 15(6): 587-592, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27919847

RESUMO

BACKGROUND: Split liver transplantation increases the number of grafts available for transplantation. Pre-recovery assessment of liver graft volume is essential for selecting suitable recipients. The purpose of this study was to determine the ability and feasibility of constructing a 3-D model to aid in surgical planning and to predict graft weight prior to an in situ division of the donor liver. METHODS: Over 11 months, 3-D volumetric reconstruction of 4 deceased donors was performed using Pathfinder Scout© liver volumetric software. Demographic, laboratory, operative, perioperative and survival data for these patients along with donor demographic data were collected prospectively and analyzed retrospectively. RESULTS: The average predicted weight of the grafts from the adult donors obtained from an in situ split procedure were 1130 g (930-1458 g) for the extended right lobe donors and 312 g (222-396 g) for left lateral segment grafts. Actual adult graft weight was 92% of the predicted weight for both the extended right grafts and the left lateral segment grafts. The predicted and actual graft weights for the pediatric donors were 176 g and 210 g for the left lateral segment grafts and 308 g and 280 g for the extended right lobe grafts, respectively. All grafts were transplanted except for the right lobe from the pediatric donors due to the small graft weight. CONCLUSIONS: On-site volumetric assessment of donors provides useful information for the planning of an in situ split and for selection of recipients. This information may expand the donor pool to recipients previously felt to be unsuitable due to donor and/or recipient weight.


Assuntos
Imageamento Tridimensional/métodos , Transplante de Fígado/métodos , Fígado/anatomia & histologia , Fígado/cirurgia , Modelagem Computacional Específica para o Paciente , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Doadores de Tecidos/provisão & distribuição , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Técnicas de Apoio para a Decisão , Seleção do Doador , Estudos de Viabilidade , Feminino , Humanos , Transplante de Fígado/efeitos adversos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Valor Preditivo dos Testes , Estudos Retrospectivos , Software , Resultado do Tratamento , Adulto Jovem
8.
Liver Transpl ; 21(8): 1082-90, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25991054

RESUMO

This study analyzed how features of a liver graft and the technique of biliary reconstruction interact to affect biliary complications in pediatric liver transplantation. A retrospective analysis was performed of data collected from 2001 to 2011 in a single high-volume North American pediatric transplant center. The study cohort comprised 173 pediatric recipients, 75 living donor (LD) and 98 deceased donor (DD) recipients. The median follow-up was 70 months. Twenty-nine (16.7%) patients suffered a biliary complication. The majority of leaks (9/12, 75.0%) and the majority of strictures (18/22, 81.8%) were anastomotic. There was no difference in the rate of biliary complications associated with DD (18.4%) and LD (14.7%) grafts (P = 0.55). Roux-en-Y (RY) reconstruction was associated with a significantly lower rate of biliary complications compared to duct-to-duct reconstruction (13.3% versus 28.2%, respectively; P = 0.048). RY anastomosis was the only significant factor protecting from biliary complications in our population (hazard ratio, 0.30; 95% confidence interval, 0.1-0.85). The leaks were managed primarily by relaparotomy (10/12, 83.3%), and the majority of strictures were managed by percutaneous biliary intervention (14/22, 63.6%). Patients suffering biliary complications had inferior graft survival (P = 0.04) at 1, 5, and 10 years compared to patients without biliary complications. Our analysis demonstrates a lower incidence of biliary complications with RY biliary reconstruction, and patients with biliary complications have decreased graft survival.


Assuntos
Doenças Biliares/epidemiologia , Doenças Biliares/terapia , Transplante de Fígado/efeitos adversos , Adolescente , Fatores Etários , Doenças Biliares/diagnóstico , Doenças Biliares/mortalidade , Criança , Pré-Escolar , Feminino , Sobrevivência de Enxerto , Hospitais com Alto Volume de Atendimentos , Humanos , Incidência , Lactente , Estimativa de Kaplan-Meier , Transplante de Fígado/métodos , Transplante de Fígado/mortalidade , Doadores Vivos , Masculino , Ontário/epidemiologia , Reoperação , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
9.
Liver Transpl ; 21(3): 321-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25545787

RESUMO

Liver transplantation (LT) with donation after circulatory death (DCD) donors has been associated with a high rate of ischemic-type biliary strictures (ITBSs) and inferior graft survival. To investigate the impact of an intraoperative tissue plasminogen activator (tPA) on outcomes following DCD LT, we conducted a retrospective analysis of DCD LT at the Toronto General Hospital (TGH) and the Ochsner Medical Center (OMC). Between 2009 and 2013, 85 DCD LTs were performed with an intraoperative tPA injection (n = 30 at TGH, n = 55 at OMC), and they were compared with 33 DCD LTs without a tPA. Donor and recipient characteristics were similar in the 2 groups. There was no significant difference in the intraoperative packed red blood cell transfusion requirement (3.2 ± 3.4 versus 3.1 ± 2.3 U, P = 0.74). Overall, biliary strictures occurred less commonly in the tPA-treated group (16.5% versus 33.3%, P = 0.07) with a much lower rate of diffuse intrahepatic strictures (3.5% versus 21.2%, P = 0.005). After 1 and 3 years, the tPA group versus the non-tPA group had superior patient survival (97.6% versus 87.0% and 92.7% versus 79.7%, P = 0.016) and graft survival (96.4% versus 69.7% and 90.2% versus 63.6%, P < 0.001). In conclusion, a tPA injection into the hepatic artery during DCD LT reduces ITBSs and improves graft and patient survival without increasing the risk for bleeding.


Assuntos
Colestase/prevenção & controle , Fibrinolíticos/administração & dosagem , Isquemia/prevenção & controle , Transplante de Fígado/efeitos adversos , Terapia Trombolítica/métodos , Doadores de Tecidos , Ativador de Plasminogênio Tecidual/administração & dosagem , Adulto , Idoso , Perda Sanguínea Cirúrgica/prevenção & controle , Transfusão de Sangue , Causas de Morte , Colestase/diagnóstico , Colestase/etiologia , Seleção do Doador , Feminino , Sobrevivência de Enxerto , Artéria Hepática , Humanos , Injeções Intra-Arteriais , Isquemia/diagnóstico , Isquemia/etiologia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Nova Orleans , Ontário , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
10.
Bioorg Med Chem Lett ; 24(10): 2288-94, 2014 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24731273

RESUMO

Two novel series of spirocyclic piperidine analogs appended to a pyrazolo[1,5-a]pyridine core were designed, synthesized and evaluated for their anti-HCV activity. A series of piperidine ketals afforded dispiro 6p which showed excellent in vitro anti-HCV activities (EC50 of 1.5nM and 1.2nM against genotype 1a and 1b replicons, respectively). A series of piperidine oxazolidinones afforded 27c which showed EC50's of 10.9nM and 6.1nM against 1a and 1b replicons, respectively. Both compounds 6p and 27c bound directly to non-structural NS4B protein in vitro (IC50's=10.2 and 30.4nM, respectively) and exhibited reduced potency in replicons containing resistance mutations encoding changes in the NS4B protein.


Assuntos
Antivirais/química , Antivirais/farmacologia , Hepacivirus/fisiologia , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacos , Antivirais/síntese química , Desenho de Fármacos , Hepacivirus/efeitos dos fármacos , Hepacivirus/metabolismo , Humanos , Terapia de Alvo Molecular , Compostos de Espiro/síntese química
11.
J Surg Res ; 183(2): 869-75, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23522457

RESUMO

BACKGROUND: During organ transplantation, it is inevitable that tissues undergo cold ischemia during harvest and transport before implantation. Polyethylene-based polymers have been proposed and tested as preservation agents, with promising results. We have previously reported that a high molecular weight polyethylene glycol (PEG) (15-20,000 MW; PEG 15-20) protects the intestinal epithelium against a variety of cellular stresses, including radiation injury and microbial invasion, by mechanisms that appear to involve lipid rafts. The aim of this study was to determine the preservation effect of PEG 15-20 on the integrity of intestine grafts harvested for subsequent transplantation. MATERIALS AND METHODS: We harvested intestinal grafts from mice using a complete surgical technique for intestinal transplantation and assessed them for the effect of PEG on graft tissue integrity. We preserved half of the grafts in histidine-tryptophan-ketoglutarate solution (HTK) alone and half in HTK-PEG 15-20 solution at 4°C for 24 h. We examined gross morphology, wet to dry ratios, histology, terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine, 5'-triphosphate nick end labeling assay for apoptosis, goblet cell numbers, and bacterial localization studies to evaluate the effect of PEG on tissue integrity. RESULTS: Results demonstrated that PEG 15-20 had a superior preservation effect over HTK alone in all parameters tested. The effect of PEG was notable on attenuation of epithelial apoptosis, preservation of mucus-producing cells, and bacterial adherence to the epithelium. CONCLUSIONS: Taken together, these studies suggest that use of PEG 15-20 as a potential adjuvant during intestinal transplant may offer significant promise to prolong graft survival during organ harvest.


Assuntos
Bactérias/patogenicidade , Permeabilidade da Membrana Celular/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Intestino Delgado/microbiologia , Intestino Delgado/transplante , Preservação de Órgãos/métodos , Polietilenoglicóis/farmacologia , Animais , Permeabilidade da Membrana Celular/fisiologia , Isquemia Fria , Criopreservação/métodos , Epitélio/efeitos dos fármacos , Mucosa Intestinal/citologia , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Peso Molecular , Soluções para Preservação de Órgãos/farmacologia
12.
Surg Innov ; 20(2): 142-9, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22696025

RESUMO

Bilioenteric anastomoses are commonly performed during liver transplantation, reconstruction following tumor resection, and repair of bile duct injury. Ischemia plays an important role in both short- and long-term complications related to biliary anastomoses. The authors describe a catheter-based, suture-free approach to bilioenteric anastomosis that aims to reduce or eliminate tissue trauma and foreign material that contribute to anastomotic ischemia. The device uses a novel "umbrella" anchoring mechanism to approximate bowel to the transected bile duct over a percutaneously placed transhepatic catheter. The authors performed an open choledochojejunostomy using the device in 7 pigs. The anastomosis was assessed with cholangiography, gross inspection, and histology at the time of necropsy. The procedure was well tolerated, with no evidence of anastomotic leak in any of the study animals. This alternative catheter-based approach to bilioenteric anastomoses is safe and effective, offers potential advantages over traditional approaches, and can be easily adapted to a minimal access surgery.


Assuntos
Coledocostomia/instrumentação , Coledocostomia/métodos , Animais , Ductos Biliares/cirurgia , Engenharia Biomédica , Colangiografia , Desenho de Equipamento , Histologia , Jejuno/cirurgia , Masculino , Projetos Piloto , Complicações Pós-Operatórias , Suínos
13.
Ochsner J ; 22(4): 344-348, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36561100

RESUMO

Background: Living donor renal transplant involves highly technical operations in both a healthy donor and a recipient with end-stage kidney disease. Contrast-enhanced computed tomography angiography (CTA) is used to assess critical donor anatomy, but its interpretation becomes increasingly difficult as renal anatomy becomes more complex. Case Report: A related donor was denied because of prohibitive anatomy seen on the pretransplant evaluation CTA. As the donor was highly motivated to donate, CTA DICOM images were segmented to create a 3-dimensional (3D) model that could be evaluated in an immersive and stereoscopic virtual reality (VR) environment. The donor's anatomy was found to be acceptable, and he was approved. Conclusion: In live donor nephrectomy candidates, 3D reconstruction and VR visualization can be used to facilitate appreciation of complex anatomy.

14.
Ann Surg ; 253(6): 1094-101, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21422915

RESUMO

OBJECTIVE: The purpose of this review article is to summarize what is currently known about microbes associated with the human body and to provide examples of how this knowledge impacts the care of surgical patients. BACKGROUND: Pioneering research over the past decade has demonstrated that human beings live in close, constant contact with dynamic communities of microbial organisms. This new reality has wide-ranging implications for the care of surgical patients. METHODS AND RESULTS: Recent advances in the culture-independent study of the human microbiome are reviewed. To illustrate the translational relevance of these studies to surgical disease, we discuss in detail what is known about the role of microbes in the pathogenesis of obesity, gastrointestinal malignancies, Crohn disease, and perioperative complications including surgical site infections and sepsis. The topics of mechanical bowel preparation and perioperative antibiotics are also discussed. CONCLUSIONS: Heightened understanding of the microbiome in coming years will likely offer opportunities to refine the prevention and treatment of a wide variety of surgical conditions.


Assuntos
Metagenoma/genética , Cirurgia Geral , Técnicas Genéticas , Humanos , Metagenoma/fisiologia , Técnicas Microbiológicas , Simbiose/fisiologia
15.
Theor Biol Med Model ; 8: 33, 2011 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-21929759

RESUMO

BACKGROUND: There is a growing realization that alterations in host-pathogen interactions (HPI) can generate disease phenotypes without pathogen invasion. The gut represents a prime region where such HPI can arise and manifest. Under normal conditions intestinal microbial communities maintain a stable, mutually beneficial ecosystem. However, host stress can lead to changes in environmental conditions that shift the nature of the host-microbe dialogue, resulting in escalation of virulence expression, immune activation and ultimately systemic disease. Effective modulation of these dynamics requires the ability to characterize the complexity of the HPI, and dynamic computational modeling can aid in this task. Agent-based modeling is a computational method that is suited to representing spatially diverse, dynamical systems. We propose that dynamic knowledge representation of gut HPI with agent-based modeling will aid in the investigation of the pathogenesis of gut-derived sepsis. METHODOLOGY/PRINCIPAL FINDINGS: An agent-based model (ABM) of virulence regulation in Pseudomonas aeruginosa was developed by translating bacterial and host cell sense-and-response mechanisms into behavioral rules for computational agents and integrated into a virtual environment representing the host-microbe interface in the gut. The resulting gut milieu ABM (GMABM) was used to: 1) investigate a potential clinically relevant laboratory experimental condition not yet developed--i.e. non-lethal transient segmental intestinal ischemia, 2) examine the sufficiency of existing hypotheses to explain experimental data--i.e. lethality in a model of major surgical insult and stress, and 3) produce behavior to potentially guide future experimental design--i.e. suggested sample points for a potential laboratory model of non-lethal transient intestinal ischemia. Furthermore, hypotheses were generated to explain certain discrepancies between the behaviors of the GMABM and biological experiments, and new investigatory avenues proposed to test those hypotheses. CONCLUSIONS/SIGNIFICANCE: Agent-based modeling can account for the spatio-temporal dynamics of an HPI, and, even when carried out with a relatively high degree of abstraction, can be useful in the investigation of system-level consequences of putative mechanisms operating at the individual agent level. We suggest that an integrated and iterative heuristic relationship between computational modeling and more traditional laboratory and clinical investigations, with a focus on identifying useful and sufficient degrees of abstraction, will enhance the efficiency and translational productivity of biomedical research.


Assuntos
Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/patologia , Interações Hospedeiro-Patógeno , Pseudomonas aeruginosa/patogenicidade , Sepse/microbiologia , Software , Estresse Fisiológico , Animais , Simulação por Computador , Humanos , Intestinos/irrigação sanguínea , Intestinos/patologia , Isquemia/complicações , Isquemia/patologia , Camundongos , Modelos Biológicos , Fosfatos/deficiência , Sepse/complicações , Sepse/patologia , Virulência
16.
Int J Nurs Pract ; 17(4): 428-34, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21781222

RESUMO

The purpose of this pilot study was to test the short-term effects of the Wellness Summer Camp (WSC) on changes in children's knowledge of healthy foods and healthy snacks, physical activity and eating behaviours, and self-perception of competence in school-age children. The WSC programme activities were developed based on age-appropriate developmental theory, including healthy behaviour developmental skills and reinforcement for effective behaviour choices and action patterns. A total of 18 children who participated in the 10 day WSC were evaluated using a pretest-posttest evaluation design. The results revealed that at post-intervention, children significantly improved their knowledge about healthy foods and healthy snacks. Based on paired t-test analyses, the mean posttest scores of healthy eating behaviours and self-perception of competence were statistically significantly higher than the mean pretest scores. The mean posttest score of physical activity also increased but not statistically significant. Introducing children to the WSC programme could help maximize their opportunities to build confidence and self-competence to improve their knowledge of healthy foods and healthy snacks as well as motivate them to engage in healthy behaviours.


Assuntos
Comportamento Infantil , Promoção da Saúde , Recreação , Criança , Feminino , Humanos , Masculino , Projetos Piloto , Autoeficácia
17.
Ochsner J ; 21(3): 281-286, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34566510

RESUMO

Background: Directed blood donation is defined as the donation of blood or its components for the purpose of transfusion into a specified individual. Directed blood donation holds historic significance, and although practices as of 2021 encourage voluntary, nonrenumerated blood donations, public interest in directed donation remains. Requests to discuss the risks and benefits of directed donations are a common inquiry for transfusion medicine, transplant, and hematology/oncology professionals. This narrative review discusses the history of directed donation and summarizes directed donation considerations in the context of modern transfusion practices. Methods: We conducted a systematic search of PubMed for published literature on the topic of directed blood donation and gathered information about its benefits and potential harms with respect to the variety of products used in transfusion medicine. Results: The drawbacks of directed donation include transfusion-transmitted infection risk, alloimmunization risk, increased transfusion-associated graft vs host disease risk, decreased expediency in treatment, and increased administrative burdens. However, a role remains for directed blood donation in specific patient populations, such as individuals with rare blood types or immunoglobulin A deficiencies, because of the difficulties in finding compatible blood for transfusion. Conclusion: Clinicians should consider the risks and benefits when discussing directed blood donations with patients and family members.

19.
PLoS One ; 14(4): e0216242, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31034519

RESUMO

Transplanting donor livers with severe macrosteatosis is associated with increased risk of primary non-function (PNF). The purpose of this study was to identify steatosis-driven biomarkers as a predisposition to severe liver damage and delayed recovery following ischemia reperfusion injury. Wistar rats were fed a methionine- and choline-deficient (MCD) diet for up to three weeks to achieve severe macrosteatosis (>90%). Animals underwent diet withdrawal to control chow and/or underwent ischemia reperfusion and partial hepatectomy injury (I/R-PHx) and reperfused out to 7 days on control chow. For animals with severe macrosteatosis, hepatic levels of IL-33 decreased while Cyclin D1 levels increased in the absence of NF-κB p65 phosphorylation. Animals with high levels of nuclear Cyclin D1 prior to I/R-PHx either did not survive or had persistent macrosteatosis after 7 days on control chow. Survival 7 days after I/R-PHx fell to 57% which correlated with increased Cyclin D1 and decreased liver IL-33 levels. In the absence of I/R-PHx, withdrawing the MCD diet normalized IL-33, Cyclin D1 levels, and I/R-PHx survival back to baseline. In transplanted grafts with macrosteatosis, higher Cyclin D1 mRNA expression was observed. Shifts in Cyclin D1 and IL-33 expression may identify severely macrosteatotic livers with increased failure risk if subjected to I/R injury. Clinical validation of the panel in donor grafts with macrosteatosis revealed increased Cyclin D1 expression corresponding to delayed graft function. This pre-surgical biomarker panel may identify the subset of livers with increased susceptibility to PNF.


Assuntos
Ciclina D1/metabolismo , Fígado Gorduroso/metabolismo , Interleucina-33/metabolismo , Traumatismo por Reperfusão/metabolismo , Adulto , Animais , Biomarcadores/metabolismo , Dieta , Modelos Animais de Doenças , Suscetibilidade a Doenças , Humanos , Fígado/metabolismo , Fígado/patologia , Falência Hepática/metabolismo , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Ratos Wistar , Análise de Sobrevida
20.
Ochsner J ; 17(1): 42-45, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28331447

RESUMO

BACKGROUND: Biliary complications remain a significant problem following liver transplantation. Several surgical options can be used to deal with a significant size mismatch between the donor and recipient bile ducts during the biliary anastomosis. We compared biliary transposition to recipient biliary ductoplasty in cadaveric liver transplant. METHODS: A total of 33 reconstructions were performed from January 1, 2005 to December 31, 2013. In the biliary transposition group (n=23), 5 reconstructions were performed using an internal stent (5 or 8 French pediatric feeding tube), and 18 were performed without. Of the 10 biliary ductoplasties, 2 were performed with a stent. All patients were managed with standard immunosuppression and ursodiol. Follow-up ranged from 2 months to 5 years. RESULTS: No patients in the biliary transposition group required reoperation; 1 patient had an internal stent removed for recurrent unexplained leukocytosis, and 2 patients required endoscopic retrograde cholangiography and stent placement for evidence of stricture. Three anastomotic leaks occurred in the biliary ductoplasty group, and 2 patients in the biliary ductoplasty group required reoperation for biliary complications. CONCLUSION: Our results indicate that biliary reconstruction can be performed with either biliary transposition or biliary ductoplasty. These techniques are particularly useful when a significant mismatch in diameter exists between the donor and recipient bile ducts.

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