No description available.

The purpose is trying to classify the Liver Fibrosis stage using Gadoxetic Acid-EnhancedMR Images.  In the very beginning, a method proposed by one Korean group is being examined and trying to reproduce their result. However, the performance is not as impressive as theirs. Then, some gray-scale image feature extraction methods are used. Last but not least, the hottest method in recent years - ConvolutionNeural Network(CNN) was utilized. Finally, the performance has been evaluated in both methods. The result shows that with manual feature extraction, the Adaboost model works pretty well that AUC achieves 0.9. Besides, the AUC of ResNet-18 network - a deep learning architecture, can reach 0.93. Also, all the hyperparameters and training settings used on ResNet-18 can be transferred to ResNet-50/ResNet-101/InceptionV3 very well. The best model that can be obtained is ResNet-101which has an AUC of 0.96 - higher than all current publications for machine learning methods for staging liver fibrosis.

Background: Liver fibrosis induced by non-alcoholic fatty liver disease causes peri-interventional complications in morbidly obese patients. We determined the performance of transient elastography (TE), acoustic radiation force impulse (ARFI) imaging, and enhanced liver fibrosis (ELF) score for fibrosis detection in bariatric patients. Patients and Methods: 41 patients (median BMI 47 kg/m2) underwent 14-day low-energy diets to improve conditions prior to bariatric surgery (day 0). TE (M and XL probe), ARFI, and ELF score were performed on days -15 and -1 and compared with intraoperative liver biopsies (NAS staging). Results: Valid TE and ARFI results at day -15 and -1 were obtained in 49%/88%and 51%/90%of cases, respectively. High skin-to-liver-capsule distances correlated with invalid TE measurements. Fibrosis of liver biopsies was staged as F1 and F3 in n = 40 and n = 1 individuals. However, variations (median/range at d-15/-1) of TE (4.6/2.6–75 and 6.7/2.9–21.3 kPa) and ARFI (2.1/0.7–3.7 and 2.0/0.7–3.8 m/s) were high and associated with overestimation of fibrosis. The ELF score correctly classified 87.5%of patients. Conclusion: In bariatric patients, performance of TE and ARFI was poor and did not improve after weight loss. The ELF score correctly classified the majority of cases and should be further evaluated.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第17974号 / 医博第3838号 / 新制||医||1001(附属図書館) / 80818 / 京都大学大学院医学研究科医学専攻 / (主査)教授 羽賀 博典, 教授 坂井 義治, 教授 千葉 勉 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18508号 / 医博第3928号 / 新制||医||1005(附属図書館) / 31394 / 京都大学大学院医学研究科医学専攻 / (主査)教授 川口 義弥, 教授 稲垣 暢也, 教授 千葉 勉 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DGAM

Advanced liver fibrosis in chronic hepatitis C infection (HCV) is associated with a generalized impaired immune system. Many immune cells are affected in chronic liver disease, including CD8+ T cells. The Crawley lab reported CD8+ T cell hyperfunction in cirrhotic HCV-infected individuals that persisted after effective antiviral therapy. To evaluate the link between CD8+ T cell dysfunction in advanced fibrosis, we adapted a hepatotoxic carbon tetrachloride (CCl4) murine model. We consistently observed severe fibrosis in CCl4-treated mice resembling fibrosis in chronic HCV infected individuals. After stimulation of PBMC, the proportion of granzyme B+, and IFN-γ+ CD8+ T cells in fibrotic mice was significantly higher than the controls, particularly naïve and central memory CD8+ T cells. This state of hyperfunction was sustained after liver insult removal and significant fibrosis regression to near normal tissue integrity. Sex differences were also studied in this model and were apparent after prolonged exposure to CCl4 and in the capacity to repair liver fibrosis. Following an ectopic challenge with cancer cells, tumor growth was significantly greater in fibrotic mice. Moreover, the response to immunotherapy was significantly delayed in CCl4-treated mice. In summary, we reported for the first time that circulating CD8+ T cells are hyperfunctional in a murine model of advanced liver fibrosis in response to a hepatotoxin. In this context, affected mice failed to control the growth of a tumor whose growth is known to be controlled by a robust CD8+ T cell response. In addition, the reduced responses to immunotherapeutic effects suggest deficiencies in antigen-specific CD8+ T cell responses. Therefore, this animal model might be useful to identify mechanistic targets with translational potential for immune restoring treatments in human chronic liver diseases with advanced liver fibrosis.

No description available.

The Gadd45 family of proteins (Gadd45a, Gadd45b, and Gadd45g) has been shown to act as stress sensors in response to various physiological and environmental stressors, including oncogenic stress. However, the role of Gadd45b in senescence remained unclear. Here, we show for the first time that primary mouse embryo fibroblasts (MEFs) from Gadd45b null mice proliferate slowly; accumulate increased levels of DNA damage, and senesce prematurely. Notably, this is in contrast with Gadd45a null MEFs that show enhanced growth rate and escape senescence. This difference in growth rate increases with increasing passage number, suggesting that senescence results from exposure to environmental stressors. The impaired proliferation and increased senescence in Gadd45b null MEFs can be partially reversed by culturing cells at physiological oxygen levels, indicating that in the absence of Gadd45b, primary MEFs are less able to cope with elevated levels of oxidative stress. Interestingly, in contrast to other senescent MEFs, which arrest at G1 phase of cell cycle, Gadd45b null MEFs arrest at the G2/M phase of cell cycle. Furthermore, FACS analysis of Gadd45b null MEFs showed less phospho-histone H3-positive cells compared to wild type MEFs indicating that Gadd45b null MEFs are arrested in G2 phase rather than M phase. Interestingly, other stressors such as sub-lethal H2O2 and UV irradiation, that are known to increase oxidative stress, triggered increased premature senescence in Gadd45b null MEFs compared to wild type MEFs. By staining embryos for SA-β-gal gal, we also show that embryos from Gadd45b null mice exhibit increased SA-β-gal gal staining compared to wild type embryos, thus providing in vivo evidence for increased senescence in Gadd45b null mice. Finally, investigating the effect of loss of Gadd45b on senescence related diseases, we show that loss of Gadd45b promotes senescence and aging phenotypes in the skin as well as increased senescence and attenuated fibrotic response to CCl4 induced liver fibrosis. Together, these results highlight a novel and significant role for Gadd45b in the senescence response of cells to stress. / Molecular Biology and Genetics

The cellular microenvironment in vivo consists of both mechanical and chemical signals, which drive cell function and fate. These signals include the composition, architecture, and mechanical properties of the extracellular matrix (ECM), signaling molecules secreted by cells into their surroundings, as well as physical interactions between neighboring cells. Cells are able to interact with their surroundings through a number of different mechanisms such as remodeling of the ECM through adhesion, contraction, degradation, and deposition of proteins, as well as the secretion of pro- or anti-inflammatory molecules. In diseased states, where homeostasis has been perturbed, inflammatory signals are secreted which can modify the cellular microenvironment. Diseased states such as cancer and fibrosis are often associated with the excessive production of ECM proteins that subsequently lead to an increase in tissue stiffness and changes to ECM architecture. Such changes to the mechanical properties of the cellular microenvironment affect the cytoskeletal arrangement, migration and adhesion of both the parenchymal cells, as well as immune response cells, which migrate to the sites of injury. Further understanding of the inflammatory responses and their relationships to tissue stiffness and ECM architecture could aid in the development of novel strategies to predict diseases as well as to target and monitor therapies. Since inflammation and mechanical properties of the affected tissue are closely interlinked, obtaining a detailed understanding of the interplay between the properties of the microenvironment and the cells that reside within it will be very beneficial to obtain physiologically relevant information. We have investigated the combinatorial effects of matrix stiffness, and architecture in the presence of co-cultures of cells to determine the overall effect on cellular responses and phenotypes. We have conducted studies on co-cultures of cells in 2D and 3D environments to identify how cellular behavior is affected by dimensionality. / PHD / The cellular microenvironment in vivo consists of both mechanical and chemical signals, which drive cell function and fate. These signals include the composition and organization of the extracellular matrix (ECM), signaling molecules secreted by cells into their surroundings, as well as physical interactions between neighboring cells. Cells are able to interact with their surroundings through reorganization of the ECM and secretion of pro- or anti-inflammatory molecules. In diseased states, inflammatory signals are secreted which can modify the cellular microenvironment. Diseased states such as cancer and fibrosis are often associated with the excessive production of ECM proteins that subsequently lead to an increase in tissue stiffness and changes to ECM architecture. Such changes to the mechanical properties of the cellular microenvironment affect the function and behavior of cells within a given tissue. Further understanding of the inflammatory responses and their relationships to tissue stiffness and ECM architecture could aid in the development of novel strategies to predict diseases as well as to target and monitor therapies. Since inflammation and mechanical properties of the affected tissue are closely interlinked, obtaining a detailed understanding of the interplay between the properties of the microenvironment and the cells that reside within it will be very beneficial to obtain physiologically relevant information. We have investigated the combinatorial effects of matrix stiffness, and architecture in the presence of co-cultures of cells to determine the overall effect on cellular responses and phenotypes. We have conducted studies on co-cultures of cells in 2D and 3D environments to identify how cellular behavior is affected by dimensionality.

A infecção crônica pelo vírus da hepatite C (HCV) é importante fator de risco para o desenvolvimento de cirrose hepática e de carcinoma hepatocelular. A evolução para formas mais graves está relacionada a fatores ligados ao vírus, ao hospedeiro e à resposta imune. O objetivo deste estudo foi avaliar a associação entre os polimorfismos do gene HLA-E, a expressão da molécula HLA-E e a gravidade da doença hepática pelo HCV. Foram incluídos 112 pacientes com hepatite C crônica e avaliados parâmetros clínicos, bioquímicos e histológicos (esteatose, atividade inflamatória e fibrose hepática). A variabilidade do gene HLA-E foi avaliada por sequenciamento de Sanger, e a expressão hepática da molécula, por imunoistoquímica. Para comparação da expressão hepática da molécula HLA-E e da variabilidade do gene HLA-E, foram usados dois grupos controles de indivíduos sem hepatopatia da mesma região geográfica. A imunoistoquímica para HLA-E identificou expressão da molécula nos hepatócitos e nas células de Kupffer. A expressão de HLAE em hepatócitos e células de Kupffer foi encontrada em 56,3% e 43,8% dos pacientes com HCV e em 20% e 10% nos controles (P = 0,008 e 0,02), respectivamente. Foi identificado que o percentual de pacientes do sexo masculino, com expressão moderada de HLA-E em células de Kupffer, foi maior em relação aos pacientes do sexo feminino (22,8% x 7,3%; P = 0,03). As amostras de fígado classificadas como esteatose, atividade necroinflamatória e fibrose graves apresentaram maior grau de expressão de HLA-E em células de Kupffer e hepatócitos, com associação linear significativa. Na análise multivariada, as variáveis que influenciaram significativamente a gravidade da doença foram a expressão da molécula HLA-E nos hepatócitos, a idade avançada e o índice de massa corporal maior que 25. Foram identificados 14 haplótipos diferentes do gene HLA-E, quatro deles ainda não descritos na literatura. A frequência do alelo HLA-E*01:01:01:03 foi menor no grupo de pacientes, quando comparada ao controle (P = 0,0001). O alelo HLA-E*01:03:05 associou-se a maior probabilidade (OR = 4,69) de expressão da molécula HLA-E, na célula de Kupffer (P = 0,046). O genótipo TT do polimorfismo +424 T/C (rs1059510) associou-se a menor probabilidade (OR = 0,06) de expressão da molécula HLA-E, na célula de Kupffer, em relação à ausência de expressão (P=0,009), a menor probabilidade (OR = 0,22) de atividade inflamatória moderada/grave em relação à leve (P = 0,047) e esteve associado a menor probabilidade (OR = 0,17) de fibrose hepática moderada/grave em relação à fibrose leve (P = 0,049). Os resultados do presente estudo sugerem que a pesquisa de fatores imunogenéticos, como a expressão hepática da molécula HLA-E e a identificação da variabilidade genética do HLA-E, pode ter aplicabilidade no manejo clínico dos pacientes, uma vez que auxilia na discriminação daqueles com maior risco de atingir formas avançadas da hepatite C crônica. / Chronic hepatitis C is an important risk factor for the development of cirrhosis and hepatocellular carcinoma. The severity of liver disease can be influenced by factors related to the virus, the host and the immune response. The aim of this study was to evaluate the association between HLA-E gene polymorphisms, HLA-E molecule expression and HCV liver disease severity. We included 112 patients with chronic hepatitis C and evaluated clinical, biochemical and histological parameters (steatosis, inflammatory activity and liver fibrosis). The variability of the HLA-E gene was assessed by Sanger sequencing and liver HLA-E expression by immunohistochemistry. Two control groups of individuals without hepatopathy from the same geographical region were used to compare the HLA-E expression and the gene variability. Immunohistochemistry for HLA-E showed positivity in hepatocyte and Kupffer cell. HLA-E positivity in hepatocytes and Kupffer cells were found in 56.3% and 43.8% of HCV patients and in 20% and 10% in the controls (P = 0.008 and 0.02), respectively. We found that the percentage of male patients with moderate HLA-E expression in Kupffer cells was higher than in females (22.8% vs. 7.3%, P = 0.03). The liver samples classified as severe fibrosis, necroinflammatory activity and steatosis presented greater expression of HLA-E on Kupffer cells and hepatocytes. There was a positive linear association between HLA-E expression and severity of liver damage (P<0.05). In the multivariate analysis, the variables that significantly influenced the severity of the disease were HLA-E molecule expression in hepatocytes, advanced age and body mass index greater than 25. Fourteen different HLA-E haplotypes were identified, four of them not yet described in the literature. The frequency of the HLA-E * 01: 01: 01: 03 allele was lower in the group of patients than in the control group (P = 0.0001). The HLA-E * 01: 03: 05 allele was associated with increased likelihood (OR = 4.69) of HLA-E expression in the Kupffer cell (P = 0.046). The TT genotype of the +424 T / C polymorphism (rs1059510) was associated with a lower probability (OR = 0.06) of HLA-E expression in the Kupffer cell in relation to the absence of its expression (P = 0.009), was associated with a lower probability (OR=0,22) of moderate/severe necroinflammatory activity in relation to the mild inflammatory activity (P=0,047) and was associated with a lower probability (OR = 0.17) of moderate / severe hepatic fibrosis in relation to mild fibrosis (P = 0.049). The results of the present study suggest that the study for immunogenic factors such as HLA-E liver expression and the identification of certain polymorphisms and alleles of the HLA-E gene may have applicability in the clinical management of patients since it aids in discrimination of those at greatest risk of reaching advanced forms of chronic hepatitis C.