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Importance: A new liver allocation policy was implemented by United Network for Organ Sharing (UNOS) in February 2020 with the stated intent of improving access to liver transplant (LT). There are growing concerns nationally regarding the implications this new system may have on LT costs, as well as access to a chance for LT, which have not been captured at a multicenter level. Objective: To characterize LT volume and cost changes across the US and within specific center groups and demographics after the policy implementation. Design, Setting, and Participants: This cross-sectional study collected and reviewed LT volume from multiple centers across the US and cost data with attention to 8 specific center demographics. Two separate 12-month eras were compared, before and after the new UNOS allocation policy: March 4, 2019, to March 4, 2020, and March 5, 2020, to March 5, 2021. Data analysis was performed from May to December 2022. Main Outcomes and Measures: Center volume, changes in cost. Results: A total of 22 of 68 centers responded comparing 1948 LTs before the policy change and 1837 LTs postpolicy, resulting in a 6% volume decrease. Transplants using local donations after brain death decreased 54% (P < .001) while imported donations after brain death increased 133% (P = .003). Imported fly-outs and dry runs increased 163% (median, 19; range, 1-75, vs 50, range, 2-91; P = .009) and 33% (median, 3; range, 0-16, vs 7, range, 0-24; P = .02). Overall hospital costs increased 10.9% to a total of $46â¯360â¯176 (P = .94) for participating centers. There was a 77% fly-out cost increase postpolicy ($10â¯600â¯234; P = .03). On subanalysis, centers with decreased LT volume postpolicy observed higher overall hospital costs ($41â¯720â¯365; P = .048), and specifically, a 122% cost increase for liver imports ($6â¯508â¯480; P = .002). Transplant centers from low-income states showed a significant increase in hospital (12%) and import (94%) costs. Centers serving populations with larger proportions of racial and ethnic minority candidates and specifically Black candidates significantly increased costs by more than 90% for imported livers, fly-outs, and dry runs despite lower LT volume. Similarly, costs increased significantly (>100%) for fly-outs and dry runs in centers from worse-performing health systems. Conclusions and Relevance: Based on this large multicenter effort and contrary to current assumptions, the new liver distribution system appears to place a disproportionate burden on populations of the current LT community who already experience disparities in health care. The continuous allocation policies being promoted by UNOS could make the situation even worse.
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Transplante de Fígado , Obtenção de Tecidos e Órgãos , Transplante de Fígado/economia , Humanos , Estudos Transversais , Estados Unidos , Obtenção de Tecidos e Órgãos/economia , Obtenção de Tecidos e Órgãos/legislação & jurisprudência , Política de Saúde , Masculino , Feminino , Listas de EsperaRESUMO
The mechanisms connecting obesity with type 2 diabetes, insulin resistance, nonalcoholic fatty liver disease, and cardiovascular diseases remain incompletely understood. The function of MAPK phosphatase-2 (MKP-2), a type 1 dual-specific phosphatase (DUSP) in whole-body metabolism, and how this contributes to the development of diet-induced obesity, type 2 diabetes (T2D), and insulin resistance is largely unknown. We investigated the physiological contribution of MKP-2 in whole-body metabolism and whether MKP-2 is altered in obesity and human fatty liver disease using MKP-2 knockout mice models and human liver tissue derived from fatty liver disease patients. We demonstrate that, for the first time, MKP-2 expression was upregulated in liver tissue in humans with obesity and fatty liver disease and in insulin-responsive tissues in mice with obesity. MKP-2-deficient mice have enhanced p38 MAPK, JNK, and ERK activities in insulin-responsive tissues compared with wild-type mice. MKP-2 deficiency in mice protects against diet-induced obesity and hepatic steatosis and was accompanied by improved glucose homeostasis and insulin sensitivity. Mkp-2-/- mice are resistant to diet-induced obesity owing to reduced food intake and associated lower respiratory exchange ratio. This was associated with enhanced circulating insulin-like growth factor-1 (IGF-1) and stromal cell-derived factor 1 (SDF-1) levels in Mkp-2-/- mice. PTEN, a negative regulator of Akt, was downregulated in livers of Mkp-2-/- mice, resulting in enhanced Akt activity consistent with increased insulin sensitivity. These studies identify a novel role for MKP-2 in the regulation of systemic metabolism and pathophysiology of obesity-induced insulin resistance and fatty liver disease.
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Diabetes Mellitus Tipo 2 , Fígado Gorduroso , Resistência à Insulina , Animais , Diabetes Mellitus Tipo 2/metabolismo , Fosfatase 1 de Especificidade Dupla/metabolismo , Fosfatases de Especificidade Dupla , Fígado Gorduroso/metabolismo , Humanos , Insulina/metabolismo , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosfatases da Proteína Quinase Ativada por Mitógeno , Obesidade/metabolismo , Proteínas Tirosina Fosfatases , Proteínas Proto-Oncogênicas c-akt/metabolismo , Regulação para CimaRESUMO
Pancreatic intraepithelial neoplasms (PanINs) and intraductal papillary mucinous neoplasms (IPMNs) are common pancreatic adenocarcinoma precursor lesions. However, data regarding their respective associations with survival rate and prognosis are lacking. We retrospectively evaluated 72 pancreatic adenocarcinoma tumor resection patients at the University of Kansas Hospital between August 2009 and March 2019. Patients were divided into one of two groups, PanIN or IPMN, based on the results of the surgical pathology report. We compared baseline characteristics, overall survival (OS), and progression free survival (PFS) between the two groups, as well as OS and PFS based on local or distant tumor recurrence for both groups combined. 52 patients had PanINs and 20 patients had IPMNs. Patients who had an IPMN precursor lesion had better median PFS and OS when compared to patients with PanIN precursor lesions. However, the location of tumor recurrence (local or distant) did not show a statistically significant difference in OS.
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INTRODUCTION: Ampullary cancers represent a subset of periampullary cancers, comprising only 0.2% all gastrointestinal cancers. Localized disease is primarily managed by a surgical intervention, called pancreaticoduodenectomy (PD), followed in many cases by the administration of adjuvant chemotherapy (CT) or chemoradiation therapy (CRT). However, there are no clear evidence-based guidelines to aid in selecting both the modality and regimen of adjuvant therapy for resected Ampullary carcinoma. METHODS: We retrospectively analyzed 54 patients at KU Cancer Center, who had undergone endoscopic resection or pancreaticoduodenectomy (PD) for Ampullary cancer from June 2006 to July 2016. We obtained patients' baseline characteristics, clinical presentation, pathology, treatment modality, recurrence pattern, and survival outcomes. The time-to-events data were compared using Kaplan-Meier methods. A univariate and multivariate Cox proportional hazards regression was performed to evaluate factors associated with overall survival (OS) and generate hazard ratios (HR). RESULTS: The mean age of the 54 patients was 68 (37-90). 38 (70%) were males and 16 (30%) were females. Most of the patients were Caucasian (76%). Approximately half of all patients had a history of smoking, 20% had alcohol abuse, and 13% had pancreatitis. Among the 54 patients with localized cancers, 9 (16%) were treated definitively with nonoperative therapies, usually due to a prohibitive comorbidity profile, performance status, or unresectable tumor. 45 out of 54 patients (83%) underwent surgery. Of the 45 patients who underwent surgery, 18 patients (40% of the study cohort) received adjuvant therapy due to concerns for advanced disease as determined by the treating physician. 13 patients (24%) received adjuvant CT and 5 patients (9.2%) received CRT. The remaining 27 patients (50%) underwent surgery alone. The median OS for the entire study cohort was 30 months. When compared to surgery alone, adjuvant therapy with either CT or CRT had no statistically significant difference in terms of progression-free survival (p=0.56) or overall survival (p=0.80). In univariate Cox proportional hazards regression analysis, high-risk features like peripancreatic extension (16%) and perineural invasion (26%) were found to be associated with poor OS. Lymph node metastasis (29%) did not significantly affect OS (HR 1.42, 95% CI [0.73-1.86]; p=0.84). Lymphovascular invasion (29%) was not associated with poor OS (HR 1.22, 95% CI [0.52, 2.96]; p=0.76). In multivariate Cox regression analysis, only age group>70 years was significantly associated with OS , while other factors, including the receipt of adjuvant therapy, lymph nodes, positive margin, and lymphovascular, perineural, and peripancreatic involvement, were not significantly associated with OS. These results are likely due to small sample size. CONCLUSIONS: Despite numerous advances in both cancer care and research, efforts in rare malignancies such as Ampullary cancer remain very challenging with a clear lack of an evidence-based standard of care treatment paradigm. Although adding adjuvant therapies such as chemotherapy or chemoradiotherapy is likely to improve survival in high-risk disease, there is no standardized regimen for the treatment of Ampullary cancer. More research is required to elucidate whether statistically and clinically relevant differences exist that may warrant a change in the current adjuvant treatment strategies.
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Alcohol is a well-established risk factor for hepatocellular carcinoma (HCC), but the mechanisms by which it promotes liver cancer are not well understood. Several studies have shown that cellular protein arginine methylation is inhibited by alcohol. Arginine methylation is controlled by the reciprocal activity of protein arginine methyltransferases, primarily protein arginine methyl transferase 1 (PRMT1), and a demethylase Jumonji C domain-containing protein 6 (JMJD6). The aim of this study was to explore the role of arginine methylation changes in alcohol pathogenesis. We found that PRMT1 activity is inhibited in livers of mice fed with alcohol compared to pair-fed mice. Using hepatocyte-specific PRMT1 knockout mice, we identified that loss of PRMT1 results in enhanced hepatocyte proliferation and a 33% increase in liver size. This increased hepatocyte proliferation was associated with reduced expression of hepatocyte nuclear factor 4 alpha (Hnf4α), an important regulator of liver tumorigenesis. We found that PRMT1 regulates Hnf4α expression directly through arginine methylation at the (Hnf4α) promoter. In the absence of PRMT1, JMJD6 can demethylate the Hnf4α promoter and suppress its expression. We were able to restore Hnf4α expression and abolish the increase in hepatocyte proliferation by knockdown of JMJD6 in PRMT1 knockout mice. Knockdown of JMJD6 in alcohol-fed mice similarly increased Hnf4α expression. We then examined whether loss of arginine methylation might play a role in alcohol-associated liver cancers. We examined 25 human HCC specimens and found a strong correlation (R = 0.8; P < 0.01) between arginine methylation levels and Hnf4α expression in these specimens, suggesting that the above mechanism is relevant in patients. CONCLUSION: Taken together, these data suggest that PRMT1 inhibition, such as induced by alcohol, may result in epigenetic changes leading to loss of Hnf4α. This effect may contribute to alcohol's ability to promote liver tumors. (Hepatology 2018;67:1109-1126).
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Carcinoma Hepatocelular/metabolismo , Fator 4 Nuclear de Hepatócito/metabolismo , Hepatócitos/metabolismo , Neoplasias Hepáticas/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Arginina/metabolismo , Western Blotting , Carcinogênese/metabolismo , Carcinoma Hepatocelular/patologia , Técnicas de Cultura de Células , Proliferação de Células/genética , Imunoprecipitação da Cromatina , Etanol/efeitos adversos , Etanol/farmacologia , Regulação Neoplásica da Expressão Gênica , Hepatócitos/patologia , Humanos , Imuno-Histoquímica , Fígado/patologia , Neoplasias Hepáticas/patologia , Metilação , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Protein arginine methyltransferase 1 (PRMT1) is an essential enzyme controlling about 85% of the total cellular arginine methylation in proteins. We have shown previously that PRMT1 is an important regulator of innate immune responses and that it is required for M2 macrophage differentiation. c-Myc is a transcription factor that is critical in regulating cell proliferation and also regulates the M2 transcriptional program in macrophages. Here, we sought to determine whether c-Myc in myeloid cells is regulated by PRMT1-dependent arginine methylation. We found that PRMT1 activity was necessary for c-Myc binding to the acetyltransferase p300. PRMT1 inhibition decreased p300 recruitment to c-Myc target promoters and increased histone deacetylase 1 (HDAC1) recruitment, thereby decreasing transcription at these sites. Moreover, PRMT1 inhibition blocked c-Myc-mediated induction of several of its target genes, including peroxisome proliferator-activated receptor γ (PPARG) and mannose receptor C-type 1 (MRC1), suggesting that PRMT1 is necessary for c-Myc function in M2 macrophage differentiation. Of note, in primary human blood monocytes, p300-c-Myc binding was strongly correlated with PRMT1 expression, and in liver sections, PRMT1, c-Myc, and M2 macrophage levels were strongly correlated with each other. Both PRMT1 levels and M2 macrophage numbers were significantly lower in livers from individuals with a history of spontaneous bacterial peritonitis, known to have defective cellular immunity. In conclusion, our findings demonstrate that PRMT1 is an important regulator of c-Myc function in myeloid cells. PRMT1 loss in individuals with cirrhosis may contribute to their immune defects.
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Células Mieloides/metabolismo , Regiões Promotoras Genéticas , Processamento de Proteína Pós-Traducional , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transcrição Gênica , Fatores de Transcrição de p300-CBP/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Arginina/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Imunoprecipitação da Cromatina , Inibidores Enzimáticos/farmacologia , Histona Desacetilase 1/metabolismo , Humanos , Fígado/imunologia , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/imunologia , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Metilação/efeitos dos fármacos , Camundongos Knockout , Células Mieloides/efeitos dos fármacos , Células Mieloides/imunologia , Células Mieloides/patologia , Regiões Promotoras Genéticas/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Proteína-Arginina N-Metiltransferases/genética , Transcrição Gênica/efeitos dos fármacosRESUMO
A shortage of donor organs is a major limitation to liver transplantation. Expansion of donor pool criteria to include patients with schistosomiasis diagnosed on liver biopsy might allow the allocation of more transplant livers. Schistosomiasis is a chronic parasitic disease affecting millions in endemic areas including sub-Sahara Africa that might lead to the development of granulomas as a response to the parasite's ova and might cause chronic liver disease and portal hypertension. Due to increased mobility globally, schistosomiasis may be encountered in non-endemic areas. Currently, the usage of donor livers with known Schistosomiasis is not universally defined.
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Microcystins are a group of toxins produced by freshwater cyanobacteria. Uptake of microcystin-leucine arginine (MC-LR) by organic anion transporting polypeptide 1B2 in hepatocytes results in inhibition of protein phosphatase 1A and 2A, and subsequent cell death. Studies performed in primary rat hepatocytes demonstrate prototypical apoptosis after MC-LR exposure; however, no study has directly tested whether apoptosis is critically involved in vivo in the mouse, or in human hepatocytes. MC-LR (120 µg/kg) was administered to C57BL/6J mice and cell death was evaluated by alanine aminotransferase (ALT) release, caspase-3 activity in the liver, and histology. Mice exposed to MC-LR had increases in plasma ALT values, and hemorrhage in the liver, but no increase in capase-3 activity in the liver. Pre-treatment with the pan-caspase inhibitor z-VAD-fmk failed to protect against cell death measured by ALT, glutathione depletion, or hemorrhage. Administration of MC-LR to primary human hepatocytes resulted in significant toxicity at concentrations between 5 nM and 1 µM. There were no elevated caspase-3 activities and pretreatment with z-VAD-fmk failed to protect against cell death in human hepatocytes. MC-LR treated human hepatocytes stained positive for propidium iodide, indicating membrane instability, a marker of necrosis. Of note, both increases in PI positive cells, and increases in lactate dehydrogenase release, occurred before the onset of complete actin filament collapse. In conclusion, apoptosis does not contribute to MC-LR-induced cell death in the in vivo mouse model or in primary human hepatocytes in vitro. Thus, targeting necrotic cell death mechanisms will be critical for preventing microcystin-induced liver injury.
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Doença Hepática Induzida por Substâncias e Drogas/patologia , Hepatócitos/efeitos dos fármacos , Microcistinas/toxicidade , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Inibidores de Caspase/farmacologia , Morte Celular/efeitos dos fármacos , Humanos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Toxinas Marinhas , Camundongos , Camundongos Endogâmicos C57BL , Proteína Fosfatase 2/antagonistas & inibidores , Proteína Fosfatase 2C/antagonistas & inibidores , Transaminases/sangueRESUMO
Although data are available on the change of expression/activity of drug-metabolizing enzymes in liver cirrhosis patients, corresponding data on transporter protein expression are not available. Therefore, using quantitative targeted proteomics, we compared our previous data on noncirrhotic control livers (n = 36) with the protein expression of major hepatobiliary transporters, breast cancer resistance protein (BCRP), bile salt export pump (BSEP), multidrug and toxin extrusion protein 1 (MATE1), multidrug resistance-associated protein (MRP)2, MRP3, MRP4, sodium taurocholate-cotransporting polypeptide (NTCP), organic anion-transporting polypeptides (OATP)1B1, 1B3, 2B1, organic cation transporter 1 (OCT1), and P-glycoprotein (P-gp) in alcoholic (n = 27) and hepatitis C cirrhosis (n = 30) livers. Compared with control livers, the yield of membrane protein from alcoholic and hepatitis C cirrhosis livers was significantly reduced by 56 and 67%, respectively. The impact of liver cirrhosis on transporter protein expression was transporter-dependent. Generally, reduced protein expression (per gram of liver) was found in alcoholic cirrhosis livers versus control livers, with the exception that the expression of MRP3 was increased, whereas no change was observed for MATE1, MRP2, OATP2B1, and P-gp. In contrast, the impact of hepatitis C cirrhosis on protein expression of transporters (per gram of liver) was diverse, showing an increase (MATE1), decrease (BSEP, MRP2, NTCP, OATP1B3, OCT1, and P-gp), or no change (BCRP, MRP3, OATP1B1, and 2B1). The expression of hepatobiliary transporter protein differed in different diseases (alcoholic versus hepatitis C cirrhosis). Finally, incorporation of protein expression of OATP1B1 in alcoholic cirrhosis into the Simcyp physiologically based pharmacokinetics cirrhosis module improved prediction of the disposition of repaglinide in liver cirrhosis patients. These transporter expression data will be useful in the future to predict transporter-mediated drug disposition in liver cirrhosis patients.
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Etanol/metabolismo , Hepatite C/metabolismo , Cirrose Hepática/metabolismo , Fígado/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Proteoma/metabolismo , Feminino , Hepatócitos/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 2 Associada à Farmacorresistência Múltipla , Proteômica/métodosRESUMO
3'-Hydroxyacetanilide orN-acetyl-meta-aminophenol (AMAP) is generally regarded as a non-hepatotoxic analog of acetaminophen (APAP). Previous studies demonstrated the absence of toxicity after AMAP in mice, hamsters, primary mouse hepatocytes and several cell lines. In contrast, experiments with liver slices suggested that it may be toxic to human hepatocytes; however, the mechanism of toxicity is unclear. To explore this,we treated primary human hepatocytes (PHH) with AMAP or APAP for up to 48 h and measured several parameters to assess metabolism and injury. Although less toxic than APAP, AMAP dose-dependently triggered cell death in PHH as indicated by alanine aminotransferase (ALT) release and propidium iodide (PI) staining. Similar to APAP, AMAP also significantly depleted glutathione (GSH) in PHH and caused mitochondrial damage as indicated by glutamate dehydrogenase (GDH) release and the JC-1 assay. However, unlike APAP, AMAP treatment did not cause relevant c-jun-N-terminal kinase (JNK) activation in the cytosol or phospho-JNK translocation to mitochondria. To compare, AMAP toxicity was assessed in primary mouse hepatocytes (PMH). No cytotoxicity was observed as indicated by the lack of lactate dehydrogenase release and no PI staining. Furthermore, there was no GSH depletion or mitochondrial dysfunction after AMAP treatment in PMH. Immunoblotting for arylated proteins suggested that AMAP treatment caused extensive mitochondrial protein adduct formation in PHH but not in PMH. In conclusion, AMAP is hepatotoxic in PHH and the mechanism involves the formation of mitochondrial protein adducts and mitochondrial dysfunction.
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Acetanilidas/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Animais , Morte Celular/efeitos dos fármacos , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Relação Dose-Resposta a Droga , Glutamato Desidrogenase/metabolismo , Glutationa/metabolismo , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , L-Lactato Desidrogenase/metabolismo , Fígado/metabolismo , Fígado/patologia , Camundongos , Mitocôndrias Hepáticas/metabolismo , Mitocôndrias Hepáticas/patologia , Fosforilação , Cultura Primária de Células , Ligação Proteica , Transdução de Sinais/efeitos dos fármacos , Especificidade da Espécie , Fatores de TempoRESUMO
BACKGROUND: Acetaminophen (APAP) hepatotoxicity is a major cause of acute liver failure in many countries. Mechanistic studies in mice and humans have implicated formation of a reactive metabolite, mitochondrial dysfunction and oxidant stress as critical events in the pathophysiology of APAP-induced liver cell death. It was recently suggested that ATP released from necrotic cells can directly cause cell death in mouse hepatocytes and in a hepatoma cell line (HepG2). AIM: To assess if ATP can directly cause cell toxicity in hepatocytes and evaluate their relevance in the human system. METHODS: Primary mouse hepatocytes, human HepG2 cells, the metabolically competent human HepaRG cell line and freshly isolated primary human hepatocytes were exposed to 10-100 µM ATP or ATγP in the presence or absence of 5-10 mM APAP for 9-24 h. RESULTS: ATP or ATγP was unable to directly cause cell toxicity in all 4 types of hepatocytes. In addition, ATP did not enhance APAP-induced cell death observed in primary mouse or human hepatocytes, or in HepaRG cells as measured by LDH release and by propidium iodide staining in primary mouse hepatocytes. Furthermore, addition of ATP did not cause mitochondrial dysfunction or enhance APAP-induced mitochondrial dysfunction in primary murine hepatocytes, although ATP did cause cell death in murine RAW macrophages. CONCLUSIONS: It is unlikely that ATP released from necrotic cells can significantly affect cell death in human or mouse liver during APAP hepatotoxicity. RELEVANCE FOR PATIENTS: Understanding the mechanisms of APAP-induced cell injury is critical for identifying novel therapeutic targets to prevent liver injury and acute liver failure in APAP overdose patients.
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BACKGROUND: Acetaminophen (APAP) hepatotoxicity is a major cause of acute liver failure in many countries. Mechanistic studies in mice and humans have implicated formation of a reactive metabolite, mitochondrial dysfunction and oxidant stress as critical events in the pathophysiology of APAP-induced liver cell death. It was recently suggested that ATP released from necrotic cells can directly cause cell death in mouse hepatocytes and in a hepatoma cell line (HepG2). AIM: To assess if ATP can directly cause cell toxicity in hepatocytes and evaluate their relevance in the human system. METHODS: Primary mouse hepatocytes, human HepG2 cells, the metabolically competent human HepaRG cell line and freshly isolated primary human hepatocytes were exposed to 10-100 µM ATP or ATγPin the presence or absence of 5-10 mM APAP for 9-24 h. RESULTS: ATP or ATγP was unable to directly cause cell toxicity in all 4 types of hepatocytes. In addition, ATP did not enhance APAP-induced cell death observed in primary mouse or human hepatocytes, or in HepaRG cells as measured by LDH release and by propidium iodide staining in primary mouse hepatocytes. Furthermore, addition of ATP did not cause mitochondrial dysfunction or enhance APAP-induced mitochondrial dysfunction in primary murine hepatocytes, although ATP did cause cell death in murine RAW macrophages. CONCLUSIONS: It is unlikely that ATP released from necrotic cells can significantly affect cell death in human or mouse liver during APAP hepatotoxicity. RELEVANCE FOR PATIENTS: Understanding the mechanisms of APAP-induced cell injury is critical for identifying novel therapeutic targets to prevent liver injury and acute liver failure in APAP overdose patients.
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INTRODUCTION: Renal vein thrombosis, a rare complication of renal transplantation, often causes graft loss. Diagnosis includes ultrasound with Doppler, and it is often treated with anticoagulation or mechanical thrombectomy. Success is improved with early diagnosis and institution of treatment. PRESENTATION OF CASE: We report here the case of a 29 year-old female with sudden development of very late-onset renal vein thrombosis after simultaneous kidney pancreas transplant. This resolved initially with thrombectomy, stenting and anticoagulation, but thrombosis recurred, necessitating operative intervention. Intraoperatively the renal vein was discovered to be compressed by a large ovarian cyst. DISCUSSION: Compression of the renal vein by a lymphocele or hematoma is a known cause of thrombosis, but this is the first documented case of compression and thrombosis due to an ovarian cyst. CONCLUSION: Early detection and treatment of renal vein thrombosis is paramount to restoring renal allograft function. Any woman of childbearing age may have thrombosis due to compression by an ovarian cyst, and screening for this possibility may improve long-term graft function in this population.
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PURPOSE OF REVIEW: Vascularized composite tissue allografts (CTAs) provide excellent restorative options for patients with limb loss and other deformities. Acute rejection remains common with CTA and immunosuppression is used in an attempt to prevent rejection. This has created ethical debates regarding the use of intensive immunosuppression for a nonlife-saving procedure. This highlights the need for newer immunosuppressive strategies for CTA, which are described in this review. RECENT FINDINGS: Recent studies have looked into immunomodulation and tolerance to decrease toxicity of immunosuppression. Both strategies have had some success but have their own limitations. Although immunomodulation and decrease in immunosuppression decreases toxicity, it has been associated with higher rates of rejection. Induction of tolerance has achieved some initial success, but the initial conditioning regimens are associated with significant morbidity. SUMMARY: Although recent advancements have been made in the immunosuppressive strategies in CTA, the ideal immunosuppression strategy with low toxicity and infection risk but with the ability to prevent acute and chronic rejection is yet to be discovered.
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Aloenxertos Compostos/imunologia , Rejeição de Enxerto/prevenção & controle , Imunossupressores/uso terapêutico , Animais , Humanos , Tolerância Imunológica , Terapia de Alvo Molecular , Transplante HomólogoRESUMO
UNLABELLED: Acetaminophen (APAP) overdose is the most prevalent cause of drug-induced liver injury in western countries. Numerous studies have been conducted to investigate the mechanisms of injury after APAP overdose in various animal models; however, the importance of these mechanisms for humans remains unclear. Here we investigated APAP hepatotoxicity using freshly isolated primary human hepatocytes (PHH) from either donor livers or liver resections. PHH were exposed to 5mM, 10mM or 20mM APAP over a period of 48 h and multiple parameters were assessed. APAP dose-dependently induced significant hepatocyte necrosis starting from 24h, which correlated with the clinical onset of human liver injury after APAP overdose. Interestingly, cellular glutathione was depleted rapidly during the first 3h. APAP also resulted in early formation of APAP-protein adducts (measured in whole cell lysate and in mitochondria) and mitochondrial dysfunction, indicated by the loss of mitochondrial membrane potential after 12h. Furthermore, APAP time-dependently triggered c-Jun N-terminal kinase (JNK) activation in the cytosol and translocation of phospho-JNK to the mitochondria. Both co-treatment and post-treatment (3h) with the JNK inhibitor SP600125 reduced JNK activation and significantly attenuated cell death at 24h and 48h after APAP. The clinical antidote N-acetylcysteine offered almost complete protection even if administered 6h after APAP and a partial protection when given at 15 h. CONCLUSION: These data highlight important mechanistic events in APAP toxicity in PHH and indicate a critical role of JNK in the progression of injury after APAP in humans. The JNK pathway may represent a therapeutic target in the clinic.
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Acetaminofen/toxicidade , Analgésicos não Narcóticos/toxicidade , Morte Celular/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Acetaminofen/antagonistas & inibidores , Acetilcisteína/farmacologia , Adulto , Idoso , Antídotos/farmacologia , Ativação Enzimática/efeitos dos fármacos , Feminino , Glutationa/metabolismo , Hepatócitos/enzimologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Masculino , Pessoa de Meia-Idade , Mitocôndrias Hepáticas/efeitos dos fármacos , Doenças Mitocondriais/induzido quimicamente , Doenças Mitocondriais/metabolismo , Necrose/patologia , Cultura Primária de Células , Proteínas/metabolismo , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/enzimologia , Frações Subcelulares/metabolismo , Adulto JovemRESUMO
BACKGROUND: Endoscopic treatment for biliary strictures with plastic stent placement has been used widely. The use of covered self-expandable metal stents (CSEMS) has been reported in anastomotic strictures post liver transplant. The aim of this study was to evaluate the efficacy of different CSEMS in these subjects. METHODS: A total of 55 patients with anastomotic stricture received CSEMS, which were removed after 3-4 months. There were 19 patients in group A (partially covered SEMS), 21 patients in group B (fully covered SEMS with fins) and 15 patients in group C (fully covered SEMS with flared ends). Technical success, stricture resolution, follows up, and complications were documented. RESULTS: CSEMS were successfully deployed in all 55 cases. There was no evidence of significant difference with regards to stricture resolution (14 [74%] vs. 15 [71%] vs. 9 [60%] p=0.6630, df=2) or complications between groups. Stent-related complications were as follows: three in group A (2 migration, 1 occlusion), five in group B (4 occlusions, 1 migration), and one proximal migration in group C (p=0.3894, df=2). Three cases required surgery (hepatico-jejunostomy) due to refractory strictures. CONCLUSIONS: The observed clinical success rate of CSEMS (70.4%) proved to be below the reported one for multiple plastic stents, while no significant differences between CSEMS types were observed.
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Doenças dos Ductos Biliares/cirurgia , Transplante de Fígado/efeitos adversos , Implantação de Prótese/instrumentação , Stents , Adulto , Idoso , Doenças dos Ductos Biliares/etiologia , Constrição Patológica/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Adult recipients of living donor liver transplantation (LDLT) have a higher incidence of biliary complications than recipients of deceased donor liver transplantation (DDLT). Our objective was to define the intensity of the interventions and the time to resolution after the diagnosis of biliary complications after liver transplantation. We analyzed the management and resolution of posttransplant biliary complications and investigated the comparative effectiveness of interventions in LDLT and DDLT recipients. For the analysis of biliary complications (leaks or strictures), we used a retrospective cohort of patients who underwent liver transplantation at 8 centers between 1998 and 2006 (median follow-up from onset=4.7 years). The numbers, procedure types, and times to resolution were compared for LDLT and DDLT recipients. Posttransplant biliary complications occurred in 47 of the 189 DDLT recipients (25%) and in 141 of the 356 LDLT recipients (40%). Biliary leaks constituted 38% of the post-DDLT biliary complications (n=18) and 65% of the post-LDLT biliary complications (n=91). The median times to first biliary complications were similar for DDLT and LDLT (11 versus 14 days for leaks, P=0.63; 69 versus 107 days for strictures, P=0.34). Overall, 1225 diagnostic and therapeutic procedures, including reoperation and retransplantation, were performed (6.5±5.4 per recipient; 5.5±3.6 for DDLT versus 6.8±5.8 for LDLT, P=0.52). The median number of months to the resolution of a biliary complication (i.e., a tube-, stent-, and drain-free status) did not significantly differ between the DDLT and LDLT groups for leaks (2.3 versus 1.3 months, P=0.29) or strictures (4.9 versus 2.3 months, P=0.61). Although the incidence of biliary complications is higher after LDLT versus DDLT, the treatment requirements and the time to resolution after the development of a biliary complication are similar for LDLT and DDLT recipients.
Assuntos
Fístula Anastomótica/cirurgia , Colestase/cirurgia , Transplante de Fígado/efeitos adversos , Doadores Vivos , Adulto , Fístula Anastomótica/diagnóstico , Fístula Anastomótica/mortalidade , Distribuição de Qui-Quadrado , Colestase/diagnóstico , Colestase/mortalidade , Constrição Patológica , Feminino , Sobrevivência de Enxerto , Humanos , Incidência , Estimativa de Kaplan-Meier , Transplante de Fígado/mortalidade , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Reoperação , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Estados Unidos/epidemiologiaRESUMO
PURPOSE: To characterize extrahepatic pseudoaneurysm regarding incidence and etiology and determine the effectiveness of endovascular management. METHODS: A retrospective audit of 1,857 liver transplants in two institutions was performed (1996-2009). Recipients' demographics, clinical presentation, transplant type, biliary anastomosis, and presence of biliary endoprostheses were noted. Pseudoaneurysms were classified into iatrogenic (associated with biliary endoprosthesis or angioplasty) or spontaneous extrahepatic pseudoaneurysms. Spontaneous and iatrogenic pseudoaneurysms were compared for time from transplant, presenting symptoms, location in the arterial anatomy, and 3-month graft survival. Arterial patency and 6-month graft survival were calculated. RESULTS: Twenty pseudoaneurysms were found (1.1 %, 20/1,857): 9 (0.5 % of transplants, 9/1,857) were spontaneous and 11 (0.6 % of transplants, 11/1,857) were "iatrogenic" (due to minimally invasive procedures: 4 angioplasty and 7 biliary endoprostheses). Sixty percent (12/20) underwent endovascular management (4 coil embolization and 8 stent-grafts). Technical success was 83 % (10/12) with a mean arterial patency of 70 % (follow-up mean, 4.9; range, 0-18 months). The 1-, 3-, and 6-month graft survival was 70, 40, and 35 %, respectively. CONCLUSIONS: Due to minimally invasive procedures, posttransplant extrahepatic pseudoaneurysms are no longer an exclusive complication of the transplant surgery itself. Endovascular management is effective to stabilize patients but has not improved historic postsurgical graft survival.
Assuntos
Falso Aneurisma/etiologia , Aneurisma Roto/etiologia , Procedimentos Endovasculares/métodos , Artéria Hepática , Doença Iatrogênica , Transplante de Fígado/efeitos adversos , Adulto , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/terapia , Aneurisma Roto/diagnóstico por imagem , Aneurisma Roto/terapia , Estudos de Coortes , Intervalos de Confiança , Procedimentos Endovasculares/efeitos adversos , Feminino , Seguimentos , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Estimativa de Kaplan-Meier , Transplante de Fígado/métodos , Transplante de Fígado/mortalidade , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Medição de Risco , Taxa de Sobrevida , Resultado do TratamentoRESUMO
BACKGROUND: Liver transplantation is the most effective therapy for cirrhosis-associated hepatocellular carcinoma (HCC) but its utility is limited by post-transplant tumor recurrence. Use of the Milan, size-based criteria, has reduced recurrence rate to less than 10% but many patients remain ineligible. Reduction of tumor size with local therapies has been used to "downstage" patients to allow them to qualify for transplantation, but the optimal criteria to predict tumor recurrence in these latter patients has not been established. The existence of a progenitor cell population, sometimes called cancer stem cells (CSCs), has been proposed to be one mechanism accounting for the chemotherapy resistance and recurrence of hepatocellular carcinoma. The aim of this study was to determine if transcatheter arterial chemoemolization (TACE) treated tumors have increased CSC marker expression and whether these markers could be used to predict tumor recurrence. METHODS: Formalin fixed specimens were obtained from 39 HCC liver explants (23 with no treatment and 16 after TACE). Immunohistochemical staining was performed for EpCAM, CD44, CD90, and CD133. Staining for each marker was scored 0-3 by evaluating the number and intensity of positive tumor cells in 5 hpf of tumor in each specimen. RESULTS: TACE treated tumors displayed greater necrosis and fibrosis than non-TACE treated samples but there were no differences in morphology between the viable tumor cells of both groups. In TACE treated specimens, the staining of both EpCAM and CD133 was greater than in non-TACE specimens but CD44 and CD90 were the same. In the TACE group, the presence of high EpCAM staining was associated with tumor recurrence. Four of ten EpCAM high patients recurred while 0 of 6 EpCAM low patients recurred (P = 0.040). None of the other markers predicted recurrence. CONCLUSION: High pre-transplant EpCAM staining predicted HCC recurrence. This suggests that the abundance of tumor cells with a CSC phenotype may be a critical factor in the likelihood of tumor recurrence in patients receiving liver transplantation after TACE.
Assuntos
Biomarcadores Tumorais/análise , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Recidiva Local de Neoplasia/metabolismo , Células-Tronco Neoplásicas/metabolismo , Idoso , Antígenos de Neoplasias/análise , Antígenos de Neoplasias/biossíntese , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Moléculas de Adesão Celular/análise , Moléculas de Adesão Celular/biossíntese , Quimioembolização Terapêutica , Molécula de Adesão da Célula Epitelial , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Células-Tronco Neoplásicas/patologiaRESUMO
PURPOSE: The purpose of this study is to quantify hepatic arterial flow (HAF) in liver transplants with splenic steal syndrome (SSS) pre- and post-test balloon occlusion of the splenic artery utilizing Doppler ultrasound (DUS) and quantitative digitally subtracted angiography (Q-DSA). METHODS: A total of 193 liver transplants were evaluated retrospectively. Hepatic arterial velocity (HAV) and HAF were calculated utilizing DUS and Q-DSA (i-flow prototype, Siemens) pre- and post-splenic artery balloon occlusion. The rate of HAF increase, total HAF, and peak contrast density (PKD) by Q-DSA were compared with HAF by DUS. RESULTS: Of all, 4 suspected SSS cases underwent test-balloon occlusion with DUS and Q-DSA. Using DUS, HAV and HAF increased by 1.6- to 1.8-fold and 1.7- to 2.6-fold, respectively. Using Q-DSA, the HAF rate, total HAF, and PKD increased by 1.1 to 12.8, 1.5 to 7.6, and 1.3 to 5.3, respectively. CONCLUSION: Occlusion of the splenic artery in liver transplants with SSS doubles the HAF (+1.7- to 2.6-fold). The Q-DSA parameters correlate qualitatively but overestimate the resultant increased HAF.