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Sliding grating-structured triboelectric nanogenerators (SG-TENGs) can multiply transferred charge, reduce open-circuit voltage, and increase short-circuit current, which have wide application prospects in self-powered systems. However, conventional SG-TENGs have an ultrahigh internal equivalent impedance, which reduces the output voltage and energy under low load resistances (<10 MΩ). The Pulsed SG-TENGs can reduce the equivalent impedance to near zero by introducing a synchronously triggered mechanical switch (STMS), but its limited output time causes the incomplete charge transfer under high load resistances (>1 GΩ). In this paper, a conventional and pulsed hybrid SG-TENG (CPH-SG-TENG) is developed through rational designing STMS with tunable width and output time. The matching relationship among grid electrode width, contactor width of STMS, sliding speed, and load resistance has been studied, which provides a feasible solution for simultaneous realization of high output energy under small load resistances and high output voltage under high load resistances. The impedance matching range is extended from zero to at least 10 GΩ. The output performance of CPH-SG-TENG under low and high load resistances are demonstrated by passive power management circuit and arc discharge, respectively. The general strategy using tunable STMS combines the advantages of conventional and pulsed TENGs, which has broad application prospects in the fields of TENGs and self-powered systems.
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Power management circuit (PMC) can efficiently store the output energy of pulsed triboelectric nanogenerator (Pulsed-TENG). Unidirectional current Pulsed-TENG (UP-TENG) has the advantage of without using rectifier bridge. However, the energy storage efficiency is limited for large capacitors at low capacitor voltage (<10 V). To solve this problem, PMC is optimized here. Firstly, rectifier diode is used to reduce the energy loss. Energy storage efficiency of PMC using rectifier diode (D-PMC) is higher than that of conventional PMC. Then, appropriate inductor is used to further form the optimized PMC (O-PMC), which reduces the energy loss of inductor. Results show that O-PMC using 100µH inductor has the highest energy storage efficiency. The actual test energy storage efficiency of O-PMC is 30.6%, which 3.4 times higher than that of D-PMC. Finally, an external capacitor is connected to electrodes of UP-TENG to form the EUP-TENG, which improves charging speed and output voltage of O-PMC. O-PMC using EUP-TENG can stably power calculator at low motion frequencies. O-PMC can be widely used in self-powered systems.
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BACKGROUND: The right posterior segment (RPS) graft was introduced to overcome graft size discrepancy in living donor liver transplantation (LDLT). However, it was very rarely used in pediatric patients. Here we presented 4 pediatric LDLT cases receiving RPS graft between January 2015 and April 2020 in our center. A total of 1868 LDLT procedures were performed in this period. METHODS: Recipients included 1 boy and 3 girls with a median age of 45 months (range from 40 to 93 months). They were diagnosed with progressive familial intrahepatic cholestasis, propionic academia, ornithine transcarbamylase and biliary atresia, respectively. Four donors were all mothers with a median age of 32.5 years (31-38 years). Computer tomography angiography indicated posterior right branches branched off separately from main portal veins (type III variation). Three of these donor livers had 1 orifice of right hepatic veins (RHV). In the remaining 1 donor liver, the RHV showed 3 orifices and an outflow patch plastic was performed. Inferior right hepatic veins weren't found in four donor grafts. The median graft weight was 397.5 g (352-461 g) and the median graft-to-recipient weight ratio was 2.38% (1.44-2.80%). RESULTS: Postoperative complications occurred in neither donors nor recipients. Within the median follow-up duration of 29 months (14-64 months), four children are all alive with normal liver function. CONCLUSION: In summary, for older children weighed more than 15 kg with donors' variation of type III portal veins, the use of RPS grafts could be a feasible and favorable option.
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Atresia Biliar , Transplante de Fígado , Adolescente , Adulto , Atresia Biliar/cirurgia , Criança , Pré-Escolar , Feminino , Veias Hepáticas , Humanos , Doadores Vivos , Masculino , Veia Porta/cirurgiaRESUMO
BACKGROUND: Liver fibrosis is a common pathological change caused by a variety of etiologies. Early diagnosis and timely treatment can reverse or delay disease progression and improve the prognosis. This study aimed to assess the potential utility of two-dimensional shear wave elastography and texture analysis in dynamic monitoring of the progression of liver fibrosis in rat model. METHODS: Twenty rats were divided into control group (n = 4) and experimental groups (n = 4 per group) with carbon tetrachloride administration for 2, 3, 4, and 6 weeks. The liver stiffness measurement was performed by two-dimensional shear wave elastography, while the optimal texture analysis subsets to distinguish fibrosis stage were generated by MaZda. The results of elastography and texture analysis were validated through comparing with histopathology. RESULTS: Liver stiffness measurement was 6.09 ± 0.31 kPa in the control group and 7.10 ± 0.41 kPa, 7.80 ± 0.93 kPa, 8.64 ± 0.93 kPa, 9.91 ± 1.13 kPa in the carbon tetrachloride induced groups for 2, 3, 4, 6 weeks, respectively (P < 0.05). By texture analysis, histogram and co-occurrence matrix had the most frequency texture parameters in staging liver fibrosis. Receiver operating characteristic curve of liver elasticity showed that the sensitivity and specificity were 95.0% and 92.5% to discriminate liver fibrosis and non-fibrosis, respectively. In texture analysis, five optimal parameters were selected to classify liver fibrosis and non-fibrosis. CONCLUSIONS: Two-dimensional shear wave elastography showed potential applications for noninvasive monitoring of the progression of hepatic fibrosis, even in mild fibrosis. Texture analysis can further extract and quantify the texture features in ultrasonic image, which was a supplementary to further visual information and acquired high diagnostic accuracy for severe fibrosis.
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Técnicas de Imagem por Elasticidade/estatística & dados numéricos , Cirrose Hepática/diagnóstico , Fígado/diagnóstico por imagem , Animais , Modelos Animais de Doenças , Progressão da Doença , Masculino , Curva ROC , Ratos , Reprodutibilidade dos Testes , Índice de Gravidade de DoençaRESUMO
Biliary atresia (BA), the most common cause of pediatric end-stage liver disease, results from fibroinflammatory obstruction of the intrahepatic and extrahepatic bile ducts. The etiology of BA has been extensively studied, and inflammation and imbalanced immune system have been identified as the main pathogenesis of BA. B cells play roles in innate and adaptive immunity, but few studies have investigated the role of B cells in BA. This study aimed to elucidate the role of B cells in the development of BA. The percentage and numbers of total B cells (23.81 ± 11.14%ï¼P < 0.0001, 1.22 ± 0.67 × 109 L-1 , P = 0.0014) and immature B cells (25.33 ± 14.32%, P = 0.0013, 0.19 ± 0.20 × 109 L-1 , P < 0.0001) were significantly increased in the peripheral blood of patients with BA and the number of total B cells was positively correlated with gamma-glutamyl-transpeptidase in the serum of BA. High C-X-C motif chemokine ligand 8 (CXCL8) levels were detected in the serum of patients with BA. As an important source of CXCL8, B cells from patients with BA secreted more CXCL8 into peripheral blood than those from control patients. Moreover, immature B cells can secrete more CXCL8 than mature B cells, and B cells secreted CXCL8 upon activation of the nuclear factor-κB pathway. Taken together, the results revealed that B cells have a strong ability to secrete CXCL8, which is associated with the pathogenesis of BA, and exert a proinflammatory effect on the development of BA.
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Linfócitos B/imunologia , Atresia Biliar , Interleucina-8/sangue , Atresia Biliar/imunologia , Criança , Progressão da Doença , Doença Hepática Terminal , Humanos , Índice de Gravidade de DoençaRESUMO
BACKGROUND: To investigate the role of two-dimensional shear wave elastography (2D-SWE) in the preoperative evaluation of pediatric patients with biliary atresia awaiting liver transplantation. METHODS: Among a total of 152 pediatric patients enrolled in this single-institution prospective study between March 2018 and August 2019, 143 patients (age range, 4-97 months; median age, 7 months; 84 males, 59 females) who underwent successful routine ultrasound examination, SWE examination, and blood test before liver transplantation were included in the final analysis. The values of liver stiffness measured by SWE were compared with ultrasound and blood test parameters by Spearman's correlation analysis. RESULTS: The overall median liver stiffness with 2D-SWE was 29.0 ± 10.9 kPa, with a range of 9.0-53.3 kPa. The success rate of 2D-SWE measurements was 98.0% (149/152). Liver stiffness measurement (LSMs) had no significant correlation with gender, age, weight, and height of the pediatric recipients. LSMs were correlated with ultrasound parameters including portal vein (PV) maximum velocity, PV direction, hepatic artery resistance index (HARI), spleen diameter, ascites, and blood test parameters (albumin level, platelet count level, and international normalized ratio). In the pediatric recipients with hepatofugal PV flow, high HARI (HARI ⧠0.90), and ascites, or without Kasai operation, LSMs were significantly higher (P < .05). CONCLUSIONS: SWE is feasible and valuable for assessing liver damage in children with biliary atresia awaiting liver transplantation and might be used as selection criteria for children in need of priority access to liver transplantation.
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Atresia Biliar/diagnóstico por imagem , Atresia Biliar/cirurgia , Técnicas de Imagem por Elasticidade/métodos , Transplante de Fígado , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Seleção de Pacientes , Estudos ProspectivosRESUMO
BACKGROUND: Cytomegalovirus infection is one of the most common complications after solid organ transplantation. There have been several classes of antiviral drugs for the prevention of cytomegalovirus infection, such as acyclovir, valacyclovir, ganciclovir and valganciclovir. METHODS: We searched relevant prospective and multi-armed studies on PubMed from Jan. 1984 up to Mar. 2018. RESULTS: Seventeen prospective studies involving 2062 patients were included in the analysis. In the case of cytomegalovirus infection, the ganciclovir group (OR = 0.24, 95% CI 0.09-0.57) and the valacyclovir group (OR = 0.20, 95% CI 0.04-0.69) provided significantly better outcomes than the control group. The ganciclovir (OR = 0.37, 95% CI 0.13-0.86) and valacyclovir groups (OR = 0.31, 95% CI 0.07-0.98) showed moderate superiority compared to the acyclovir group. As for cytomegalovirus disease, the ganciclovir, valacyclovir and valganciclovir groups showed significant advantages compared with the control group (ganciclovir group: OR = 0.17, 95% CI 0.07-0.31, valacyclovir group: OR = 0.08, 95% CI 0.01-0.33, valganciclovir group: OR = 0.14, 95% CI 0.02-0.45). Similarly, the ganciclovir group (OR = 0.38, 95% CI 0.12-0.71) and the valacyclovir group (OR = 0.17, 95% CI 0.03-0.72) showed better results than the acyclovir group. CONCLUSION: Valacyclovir showed to be the most efficient antiviral for the prevention of cytomegalovirus infection and disease. Additional studies are required to evaluate putative side effects associated with valacyclovir administration.
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Infecções por Citomegalovirus/etiologia , Infecções por Citomegalovirus/prevenção & controle , Transplante de Órgãos/efeitos adversos , Aciclovir/uso terapêutico , Antivirais/uso terapêutico , Teorema de Bayes , Infecções por Citomegalovirus/tratamento farmacológico , Feminino , Ganciclovir/uso terapêutico , Humanos , Masculino , Valaciclovir/uso terapêutico , Valganciclovir/uso terapêuticoRESUMO
BACKGROUND: Liver transplantation is the main treatment for cholestatic liver disease and some metabolic liver diseases in children. However, no accurate prediction model to determine the survival probability of grafts prior to surgery exists. This study aimed to develop an effective prognostic model for allograft survival after pediatric liver transplantation. METHODS: This retrospective cohort study included 2032 patients who underwent pediatric liver transplantation between January 1, 2006, and January 1, 2020. A nomogram was developed using Cox regression and validated based on bootstrap sampling. Predictive and discriminatory accuracies were determined using the concordance index and visualized using calibration curves; net benefits were calculated for model comparison. An online Shiny application was developed for easy access to the model. RESULTS: Multivariable analysis demonstrated that preoperative diagnosis, recipient age, body weight, graft type, preoperative total bilirubin, interleukin-1ß, portal venous blood flow direction, spleen thickness, and the presence of heart disease and cholangitis were independent factors for survival, all of which were selected in the nomogram. Calibration of the nomogram indicated that the 1-, 3-, and 5-year predicted survival rates agreed with the actual survival rate. The concordance indices for graft survival at 1, 3, and 5 years were 0.776, 0.757, and 0.753, respectively, which were significantly higher than those of the Pediatric End-Stage Liver Disease and Child-Pugh scoring systems. The allograft dysfunction risk of a recipient could be easily predicted using the following URL: https://aspelt.shinyapps.io/ASPELT/ / CONCLUSION: The allograft survival after pediatric liver transplantation (ASPELT) score model can effectively predict the graft survival rate after liver transplantation in children, providing a simple and convenient evaluation method for clinicians and patients.
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Doença Hepática Terminal , Transplante de Fígado , Humanos , Criança , Nomogramas , Estudos Retrospectivos , Índice de Gravidade de Doença , Prognóstico , AloenxertosRESUMO
BACKGROUND: Adipose-derived stem cells (ADSCs) are particularly attractive in future clinical applications of stem cell-based therapy for acute-on-chronic liver failure (ACLF). This study was undertaken to evaluate the therapeutic potential of ADSCs on ACLF. METHODS: ADSCs isolated from porcine fat tissue were expanded and labeled with BrdU. Rabbit models of ACLF were created by administration of D-Gal following CCl4-induced cirrhosis. One day after administration of D-Gal, rabbits of the ACLF/ADSCs group (n=15) were received ADSCs transplantation, while those in the ACLF/saline group (n=15) were treated with the same volume of saline. Biochemical parameters and histomorphological scoring were evaluated; the distribution and characteristics of transplanted ADSCs as well as the pathology of the liver were examined. RESULTS: ADSCs transplantation improved the survival rate and the liver function of rabbits with ACLF. Biochemical parameters of the ACLF/ADSCs group were improved compared with those of the ACLF/saline group, and histomorphological scoring of the ACLF/ADSCs group was significantly lower than that of the ACLF/saline group. ADSCs were identified in the periportal region of the liver after cell transplantation. CONCLUSION: Xenogenic ADSCs have therapeutic efficacy in the ACLF rabbit model.
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Tecido Adiposo/citologia , Doença Hepática Terminal/terapia , Sobrevivência de Enxerto , Falência Hepática Aguda/terapia , Transplante de Células-Tronco/métodos , Células-Tronco/citologia , Tecido Adiposo/metabolismo , Animais , Animais não Endogâmicos , Biomarcadores/metabolismo , Diferenciação Celular , Modelos Animais de Doenças , Doença Hepática Terminal/mortalidade , Doença Hepática Terminal/patologia , Hepatócitos/citologia , Hepatócitos/metabolismo , Falência Hepática Aguda/mortalidade , Falência Hepática Aguda/patologia , Testes de Função Hepática , Masculino , Coelhos , Transplante de Células-Tronco/mortalidade , Células-Tronco/metabolismo , Taxa de Sobrevida , Suínos , Transplante HeterólogoRESUMO
AIMS AND OBJECTIVES: To investigate the clinical characteristics of rejection after upper abdominal cluster transplantation. BACKGROUND: Abdominal organ cluster transplantation is used to treat multiple abdominal organ diseases. Delay in monitoring and treatment can lead to graft failure. DESIGN: A descriptive study. METHODS: Data collected from eight patients who underwent abdominal organ cluster transplantation from May 2004-March 2009 in our hospital were retrospectively assessed. The clinical manifestations of graft rejection and variations in characteristics associated with graft function were analysed. RESULTS: In all eight cases, graft function recovered successfully without rejection during the perioperative period. In one case, liver graft rejection occurred 1·5 months postoperatively, but dose adjustment of the anti-rejection drugs provided symptom relief. CONCLUSIONS: Rejection can be prevented and cured successfully through monitoring and early detection of rejection characteristics by the nursing staff. RELEVANCE TO CLINICAL PRACTICE: With the increase of awareness and knowledge on the clinical observation and nursing care, the rate of transplantation rejection decreased among abdominal cluster transplant patients.
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Abdome , Rejeição de Enxerto/prevenção & controle , Transplante de Órgãos , Adulto , Idoso , Feminino , Rejeição de Enxerto/enfermagem , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Background: Tacrolimus (TAC) is the preferred calcineurin inhibitor (CNI) for pediatric liver transplant recipients. However, some recipients may not achieve the desired therapeutic window concentration of TAC, leading to poor prognosis. This study aimed to develop a clinical model that can predict the effectiveness of TAC in pediatric liver transplant recipients and help clinicians quickly identify cyclosporin as an alternative. Methods: We retrospectively analyzed data from 2,032 pediatric liver transplant recipients who underwent surgery at Renji Hospital, Shanghai Jiaotong University School of Medicine between 2006 and 2019. Demographic, comorbidity and pre-operative laboratory data were collected, and a nomogram was constructed using multivariate logistic regression analysis to estimate the risk of poor therapeutic outcomes for TAC-based immunosuppression. Results: The constructed nomogram included seven parameters, namely recipient CYP3A4 genotype, pre-transplant cholangitis, GRWR, spleen long diameter, serum albumin, graft volume reduction, and donor CYP genotype. The nomogram showed good discriminative ability with an area under the receiver operating characteristic curve (AUC) of 74.5% and good calibration. Decision curve analysis indicated a high potential clinical application of the model. Conclusion: This simple clinical model effectively predicts the risk of poor therapeutic outcomes in pediatric liver transplant recipients who receive TAC-based immunosuppression. Clinicians can use the model to identify cyclosporin as an alternative quickly, potentially improving patient prognosis.
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BACKGROUND: This study explored mental health of pediatric patients with living donor liver transplantation. METHODS: A total of 741 children who successfully underwent living donor liver transplantation from 2009 to 2019 enrolled in this study. Participants were aged between 3 and 12 years (mean age = 5.28; SD = 2.01). The Strengths and Difficulties Questionnaire was used to evaluate emotional and behavioral problems. Parents completed the 5-item World Health Organization Well-Being Index and reported their child's height, weight, sleep duration, parent-child interactions, home environment, physical activities, and time spent on screen exposure. Propensity score matching method was used to generate a control group from 20,934 healthy children. Univariate analysis and multiple logistic regression analyses were used to identify the correlational factors in children's mental health following a liver transplantation. RESULTS: Compared to healthy children, patients after liver transplantation were prone to emotional problems, hyperactivity, and peer problems. Moreover, parental mental health, physical activity, and family environment were identified as factors associated with mental health of pediatric liver transplant patients. CONCLUSION: The findings highlight the need to focus on mental health of pediatric transplant patients, increase support for parents, and strengthen positive parent-child interactions.
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BACKGROUND: There are conflicting reports on the outcomes of patients with metabolic liver disease after liver transplantation. We aimed to compare the outcomes of living donor liver transplantation (LDLT) for metabolic disease vs orthotopic liver transplantation (OLT) from deceased donation. METHODS: Clinical data of 89 patients undergoing liver transplantation for the treatment of metabolic disorders were reviewed. Pre- and peri-transplant demographics, survival rate, complications and laboratory test data were collected and analyzed. RESULTS: For the 89 patients, only 2 died by the end of the last follow-up. The post-transplant EAD rate and severe complications were higher for OLT than LDLT. No significant difference was found between LDLT and OLT for the incidence of EBV and CMV infections. In terms of laboratory indexes, the recovery time of PLT, AKP and AST levels were significantly longer for OLT than LDLT. Among different types of metabolic disease, no significant difference was found in viral infection, EAD, laboratory indexes, severe complications or duration of hospital stay. CONCLUSIONS: LDLT shows a lower incidence rate of EAD and complications, while it also shows a 1-year survival rate and incidence of viral infections compared similar to that of OLT. LDLT is the better treatment option of pediatric liver transplantation for metabolic liver disease compared with OLT.
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Transplante de Fígado , Doenças Metabólicas , Criança , Humanos , Doadores Vivos , Doenças Metabólicas/epidemiologia , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do TratamentoRESUMO
T cell exhaustion has been associated with poor prognosis in persistent viral infection and cancer. Conversely, in the context of autoimmunity, T cell exhaustion has been favorably correlated with long-term clinical outcome. Understanding the development of exhaustion in autoimmune settings may provide underlying principles that can be exploited to quell autoreactive T cells. Here, we demonstrate that the adaptor molecule Bat3 acts as a molecular checkpoint of T cell exhaustion, with deficiency of Bat3 promoting a profound exhaustion phenotype, suppressing autoreactive T cell-mediated neuroinflammation. Mechanistically, Bat3 acts as a critical mTORC2 inhibitor to suppress Akt function. As a result, Bat3 deficiency leads to increased Akt activity and FoxO1 phosphorylation, indirectly promoting Prdm1 expression. Transcriptional analysis of Bat3 -/- T cells revealed up-regulation of dysfunction-associated genes, concomitant with down-regulation of genes associated with T cell effector function, suggesting that absence of Bat3 can trigger T cell dysfunction even under highly proinflammatory autoimmune conditions.
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Background: Langerhans cell histiocytosis (LCH) is characterized by misguided myeloid differentiation, whose prognosis was poor with involvement of risk organs. Remaining issues include how to improve the outcomes of patients with risk-organ involvement. Methods: A retrospective study was conducted in Renji Hospital exploring the effects of neoadjuvant therapy in combination with pediatric liver transplantation (LT) for LCH patients based on data collected between October 2006 and October 2019. Results: We presented here five cases of multisystem LCH patients underwent systemic chemotherapy to control active lesions, followed by LT to treat end-stage liver diseases. Manifestations before LT included elevated transaminase levels (n = 5, 100%), jaundice (n = 4, 80%), ascites (n = 3, 60%), and variceal hemorrhage (n = 1, 20%). Three patients underwent orthotopic liver transplantation (OLT) and two underwent living donor liver transplantation (LDLT). Until December 2019, median follow-up time was 32 months (range, 2-67 months). Liver functions significantly improved compared with pre-operative conditions. One patient had perioperative hepatic artery complications and one patient had a recurrence in the lung. EBV infection occurred in four (80%) patients and CMV infection occurred in one (20%). There was one case of drug-induced liver injury diagnosed on biopsy 13 months after LT. None underwent re-transplantation and there were no rejection or portal vein and biliary complications. Conclusion: Combination of neoadjuvant therapy and LT is an effective paradigm in treatment of multisystem LCH with severe liver dysfunction. With advances in chemotherapy regimen for multisystem LCH and LT surgery, perspectives on prognosis for LCH children are promising.
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Pediatric post-transplant idiopathic liver fibrosis is an unexplained graft fibrosis that occurs in symptom-free children without acute rejection and surgical complications. Despite a lack of consensus on the subject, the development of pediatric post-transplant idiopathic liver fibrosis is believed to be the result of multiple potential factors, including ischemia-reperfusion injury, allogeneic acute and chronic rejection, viral hepatitis recurrence, opportunistic infection, and drug-induced liver damage. Among them, there is growing evidence that innate immunity may also have a unique role in this progression. This study reviews the features of pediatric post-transplant idiopathic liver fibrosis and discusses current studies illustrating the potential mechanisms of liver allograft tolerance induced by intrahepatic innate immunity, the role of components including Toll-like receptors (TLRs), interferons (IFN), dendritic cells (DC), natural killer cells (NK cells), NKT cells, neutrophils, and Kupffer cells, as well as their possibly relevant role in the development of pediatric post-transplant idiopathic liver fibrosis.
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Imunidade Inata , Cirrose Hepática/imunologia , Transplante de Fígado , Fígado/imunologia , Criança , Células Dendríticas/imunologia , Células Dendríticas/patologia , Humanos , Interferons/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/patologia , Fígado/patologia , Cirrose Hepática/etiologia , Cirrose Hepática/patologia , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/patologia , Receptores Toll-Like/imunologiaRESUMO
OBJECTIVE: The objective of this study was to establish a stable method of isolation, culture and cryopreservation of adult primary hepatocytes to provide potential hepatocyte resources for the treatment of acute and chronic liver diseases by hepatocyte transplantation and bioartificial liver support systems, and for the use of hepatocytes as an in vitro model of the liver. METHODS: Adult hepatocytes of 20 separate donors were isolated with a two-step extracoporeal collagenase perfusion technique. Seven preincubation time points (2h, 6h, 12h, 24h, 36h, 48h and 72h) were selected, then the hepatocytes were transferred to HepatoZYME-SFM medium containing 10% FBS and 10% DMSO, and were immediately put into an isopropanol progressive freezing container at -80 degrees C overnight and immersed in liquid nitrogen the next day. During the postthawing culture period, viability, plating efficiency, albumin secretion and urea synthesis were analyzed. RESULTS: The viability and plating efficiency of hepatocytes after partial hepatectomy using two-step extracorporeal collagenase perfusion technique were 75.0+/-4.6% and 72.0+/-6.0% respectively. Preincubation at 4? for 12 hours or 24 hours proved to be the optimal time at which the albumin secretion was higher than at other time points (p<0.05). Compared to the immediate cryopreservation groups (IC), we also found significant improvement in viability (61.4+/-4.8%/62.0+/-5.6% vs. 53.4+/-4.2%, p<0.05), plating efficiency (63.2+/-5.8%/62.6+/-3.6% vs. 55.2+/-4.6%, p<0.05), albumin secretion and urea synthesis (p<0.05) at these time points. CONCLUSIONS: The two-step extracorporeal collagenase perfusion technique after partial hepatectomy provides a novel, simple, and reliable method for hepatocyte isolation. The results of the present study suggest that recovery of human hepatocytes after isolation preincubation at 4 degrees C for 12 hours to 24 hours prior to cryopreservation can obtain hepatocytes ideal for use in pharmacotoxicology, bioartificial liver and cell therapy research purposes.
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Separação Celular/métodos , Criopreservação/métodos , Hepatócitos/fisiologia , Fígado/citologia , Perfusão , Adulto , Albuminas/metabolismo , Biomarcadores/metabolismo , Adesão Celular , Técnicas de Cultura de Células , Sobrevivência Celular , Colagenases , Feminino , Hepatectomia , Hepatócitos/metabolismo , Humanos , Fígado/metabolismo , Fígado/cirurgia , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Ureia/metabolismoRESUMO
Currently, liver transplantation is the most effective treatment for end-stage liver disease. Immunosuppressive agents are required to be taken after the operations, which have significantly reduced rejection rates and improved the short-term (<1 year) survival rates. However, post-transplant complications related to the immunosuppressive therapy have led to the development of new protocols aimed at protecting renal function and preventing de novo cancer and dysmetabolic syndrome. Donor specific immune tolerance, which means the mature immune systems of recipients will not attack the grafts under the conditions without any immunosuppression therapies, is considered the optimal state after liver transplantation. There have been studies that have shown that some patients can reach this immune tolerance state after liver transplantation. The intrahepatic immune system is quite different from that in other solid organs, especially the innate immune system. It contains a variety of liver specific cells, such as liver-derived dendritic cells, Kupffer cells, liver sinusoidal endothelial cells, liver-derived natural killer (NK) cells, natural killer T (NKT) cells, and so on. Depending on their specific structures and functions, these intrahepatic innate immune cells play important roles in the development of intrahepatic immune tolerance. In this article, in order to have a deeper understanding of the tolerogenic functions of liver, we summarized the molecular mechanisms of immune tolerance induced by intrahepatic innate immune cells after liver transplantation.
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Tolerância Imunológica , Imunidade Inata , Transplante de Fígado , Animais , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Humanos , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Células de Kupffer/imunologia , Células de Kupffer/metabolismo , Fígado/imunologia , Fígado/metabolismo , Fígado/patologia , Transplante de Fígado/efeitos adversosRESUMO
Liver regeneration after partial hepatectomy (PH) is a highly orchestrated biological process in which synchronized hepatocyte proliferation is induced after massive liver mass loss. Hepatocyte proliferation could be regulated by multiple signals, such as miRNAs and autophagy, but underlying mechanism remains unclear. Here a functional miRNA during liver regeneration was identified and its underlying mechanism was delineated in vitro and in vivo. We found that miR-1907 was highly upregulated during liver regeneration after 2/3 PH at various timepoints. The level of miR-1907 was also increased in normal liver cell line treated with HGF at different concentrations. Functionally, miR-1907 enhanced hepatocyte proliferation in vitro and in vivo, and the liver/body weight ratio in miR-1907-overexpressed mice was significantly higher in comparison to the control mice after 2/3 PH. Forced expression of miR-1907 promoted autophagy activation of hepatocyte. Importantly, autophagy inhibition significantly attenuated miR-1907-induced hepatocyte proliferation and the liver/body weight ratio. Finally, GSK3ß, a suppressor of autophagy signaling, was identified as the direct target gene of miR-1907. Taken together, miR-1907 accelerates hepatocyte proliferation during liver regeneration by activating autophagy; thus pharmacological intervention regulating miR-1907/autophagy axis may be therapeutically beneficial in liver transplantation and liver failure by inducing liver regeneration.
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Autofagia , Hepatectomia , Hepatócitos , Regeneração Hepática , MicroRNAs/metabolismo , Animais , Proliferação de Células , China , Fígado , Camundongos , Camundongos Endogâmicos C57BL , Regulação para CimaRESUMO
Ischemia-reperfusion injury (IRI) is a major complication in liver transplantation (LT) and it is closely related to the recovery of grafts' function. Researches has verified that both innate and adaptive immune system are involved in the development of IRI and Kupffer cell (KC), the resident macrophages in the liver, play a pivotal role both in triggering and sustaining the sterile inflammation. Damage-associated molecular patterns (DAMPs), released by the initial dead cell because of the ischemia insult, firstly activate the KC through pattern recognition receptors (PRRs) such as toll-like receptors. Activated KCs is the dominant players in the IRI as it can secret various pro-inflammatory cytokines to exacerbate the injury and recruit other types of immune cells from the circulation. On the other hand, KCs can also serve in a contrary way to ameliorate IRI by upregulating the anti-inflammatory factors. Moreover, new standpoint has been put forward that KCs and macrophages from the circulation may function in different way to influence the inflammation. Managements towards KCs are expected to be the effective way to improve the IRI.