The importance of epigenetic changes in the development of hepatic steatosis is largely unknown. The histone variant macroH2A1 under alternative splicing gives rise to macroH2A1.1 and macroH2A1.2. In this study, we show that the macroH2A1 isoforms play an important role in the regulation of lipid accumulation in hepatocytes. Hepatoma cell line and immortalized human hepatocytes transiently transfected or knocked down with macroH2A1 isoforms were used as in vitro model of fat-induced steatosis. Gene expressions were analyzed by quantitative PCR array and Western blot. Chromatin immunoprecipitation analysis was performed to check the association of histone H3 lysine 27 trimethylation (H3K27me3) and histone H3 lysine 4 trimethylation (H3K4me3) with the promoter of lipogenic genes. Livers from knockout mice that are resistant to lipid deposition despite a high-fat diet were used for histopathology. We found that macroH2A1.2 is regulated by fat uptake and that its overexpression caused an increase in lipid uptake, triglycerides, and lipogenic genes compared with macroH2A1.1. This suggests that macroH2A1.2 is important for lipid uptake, whereas macroH2A1.1 was found to be protective. The result was supported by a high positivity for macroH2A1.1 in knockout mice for genes targeted by macroH2A1 (Atp5a1 and Fam73b), that under a high-fat diet presented minimal lipidosis. Moreover, macroH2A1 isoforms differentially regulate the expression of lipogenic genes by modulating the association of the active (H3K4me3) and repressive (H3K27me3) histone marks on their promoters. This study underlines the importance of the replacement of noncanonical histones in the regulation of genes involved in lipid metabolism in the progression of steatosis.
how a robust multidisciplinary service can be delivered to prevent HBVr in UK clinical practice through optimisation of resources and introduction of checkpoints to prevent the inappropriate administration of immunosuppression to those at signifi cant risk of HBVr.
Background: Small intestinal neuroendocrine tumours (SI NETs) represent 30–50% of small bowel neoplasms and are often associated with diverse fibrotic complications. Mesenteric fibrosis is a hallmark of SI NETs which may cause substantial morbidity and is considered an adverse feature. However, survival analyses in this group of patients are lacking. Methods: The aim of this retrospective study was to determine the overall survival (OS) and factors affecting prognosis in a large cohort of 147 patients with SI NETs and radiological evidence of mesenteric desmoplasia from our centre. The severity of desmoplasia was graded radiologically and its effect on OS and long-term complications was assessed. The median follow-up period was 82 months. Results: The median OS was 8.7 years (95% CI 6.8–9.9) with an overall 5-year survival of 71%. The univariate analysis demonstrated that an age >65 years, a liver tumour burden >50% of the hepatic parenchyma, carcinoid heart disease, chromogranin A levels >10 times the upper limit of normal, and urinary 5-hydroxyindoleacetic acid (5-HIAA) levels >5 times the upper limit of normal were poor prognosticators, while primary resection was associated with a longer OS. However, only an age >65 years and urinary 5-HIAA levels >10 times the upper limit of normal remained statistically significant after multivariate analysis. The severity of mesenteric desmoplasia did not seem to demonstrate a statistically significant relationship to OS or long-term outcomes. Conclusion: This study is the first comprehensive survival analysis of patients with SI NETs associated with mesenteric desmoplasia and has provided important and clinically relevant epidemiological data for this group of patients.
Objectives Vasoactive intestinal peptide–secreting tumors (VIPomas) are rare functioning neuroendocrine tumors often characterized by a difficult-to-control secretory syndrome and high potential to develop metastases. We hereby present the characteristics of 15 cases of VIPomas and provide a recent literature review. Methods This was a retrospective data analysis of 15 patients with VIPoma from 3 different centers and literature research through PubMed database during the last 10 years. Results Fifteen patients with VIPomas (9 with hepatic metastases at diagnosis) with watery diarrhea and raised VIP levels were studied. Ten patients (67%) had grade 2 tumors, 6 of 15 had localized disease and underwent potentially curative surgery, whereas the remaining 9 received multiple systemic therapies; 3 patients died during follow-up. The median overall survival was 71 months (range, 41–154 months). Patients who were treated with curative surgery (n = 7) had longer median overall survival compared with patients who were treated with other therapeutic modalities (44 vs 33 months). Conclusions The management of VIPomas is challenging requiring the application of multiple treatment modalities. Patients who underwent surgical treatment with curative intent appear to have higher survival rate. Central registration and larger prospective studies are required to evaluate the effect of currently employed therapies in these patients.
Since its introduction to clinical practice nearly 20 years ago, wireless capsule endoscopy has revolutionized the landscape in the diagnosis and management of small bowel diseases. Over the past 10 years, capsule endoscopy has evolved beyond the small intestine and a range of capsules are now available to examine the esophagus, stomach and colon. Because of its ease of use, tolerability, paucity of complications and ability to visualize the entire gastrointestinal tract, capsule endoscopy has entered the mainstream of clinical practice. This review of the literature summarizes the current state of capsule training and highlights the limited data available to assess reader competence and standards expected of an independent practitioner. There are neither standardized teaching strategies nor national or international metrics for accreditation of physicians and non-physicians interested in mastering this examination. Summating the few publications, there appears to be consensus that diagnostic expertise improves with experience, and that trainees should be fully supervised for at least 20 full case studies. Formative and summative assessment is advisable and the number of taught cases should not be the sole determinant of competence. The review also highlights differences in recommendations from major national gastroenterology societies. Finally, the authors discuss areas of unmet needs in teaching and learning for capsule endoscopy.
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