580 research outputs found

    Technical note: Preparation improvement of charred cadaveric viscera using sandison’s rehydrating solution for histological analysis

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    In forensic evaluation of charred corpses, internal detrimental signs may result as more significant of those observed during external examination and is often arduous to state if a victim was exposed to fire before or after death. When the histological analysis of the remaining internal viscera is necessary, the massive destruction caused by the lesion, the charring and the coarctation of the samples don't allow to give further information or to determine the remaining organic components of the viscera. This limit is determined by the intrinsic characteristics of this thermal lesivity of self-maintenance even after the exitus of the subject, worsening the initial detrimental framework. The Authors, with the purpose of improving the microscopic visualization of the samples collected from cadavers with peculiar deterioration, as in case of carbonization, suggest the use of a specific technical protocol based on the use of Sandison's rehydrating solution since the samples treated with this solution showed, at microscopic examination, a substantial histological-morphological improvement

    Reactive gamma-ketoaldehydes as novel activators of hepatic stellate cells in vitro

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    Aims: Products of lipid oxidation, such as 4-hydroxynonenal (4-HNE), are key activators of hepatic stellate cells (HSC) to a pro-fibrogenic phenotype. Isolevuglandins (IsoLG) are a family of acyclic γ-ketoaldehydes formed through oxidation of arachidonic acid or as by-products of the cyclooxygenase pathway. IsoLGs are highly reactive aldehydes which are efficient at forming protein adducts and cross-links at concentrations 100-fold lower than 4-hydroxynonenal. Since the contribution of IsoLGs to liver injury has not been studied, we synthesized 15-E2-IsoLG and used it to investigate whether IsoLG could induce activation of HSC. / Results: Primary human HSC were exposed to 15-E2-IsoLG for up to 48 hours. Exposure to 5 μM 15-E2-IsoLG in HSCs promoted cytotoxicity and apoptosis. At non-cytotoxic doses (50 pM-500 nM) 15-E2-IsoLG promoted HSC activation, indicated by increased expression of α-SMA, sustained activation of ERK and JNK signaling pathways, and increased mRNA and/or protein expression of cytokines and chemokines, which was blocked by inhibitors of JNK and NF-kB. In addition, IsoLG promoted formation of reactive oxygen species, and induced an early activation of ER stress, followed by autophagy. Inhibition of autophagy partially reduced the pro-inflammatory effects of IsoLG, suggesting that it might serve as a cytoprotective response. / Innovation: This study is the first to describe the biological effects of IsoLG in primary HSC, the main drivers of hepatic fibrosis. / Conclusions: IsoLGs represent a newly identified class of activators of HSC in vitro, which are biologically active at concentrations as low as 500 pM, and are particularly effective at promoting a pro-inflammatory response and autophagy

    Identification of potential serum peptide biomarkers of biliary tract cancer using MALDI MS profiling.

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    The aim of this discovery study was the identification of peptide serum biomarkers for detecting biliary tract cancer (BTC) using samples from healthy volunteers and benign cases of biliary disease as control groups. This work was based on the hypothesis that cancer-specific exopeptidase activities in serum can generate cancer-predictive peptide fragments from circulating proteins during coagulation

    Recombinant Alkaline Phosphatase Prevents Acute on Chronic Liver Failure

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    The lipopolysaccharide (LPS)– toll-like receptor-4 (TLR4) pathway plays an important role in liver failure. Recombinant alkaline phosphatase (recAP) deactivates LPS. The aim of this study was to determine whether recAP prevents the progression of acute and acute-on-chronic liver failure (ACLF). Eight groups of rats were studied 4-weeks after sham surgery or bile duct ligation and were injected with saline or LPS to mimic ACLF. Acute liver failure was induced with Galactosamine-LPS and in both models animals were treated with recAP prior to LPS administration. In the ACLF model, the severity of liver dysfunction and brain edema was attenuated by recAP, associated with reduction in cytokines, chemokines, liver cell death, and brain water. The activity of LPS was reduced by recAP. The treatment was not effective in acute liver failure. Hepatic TLR4 expression was reduced by recAP in ACLF but not acute liver failure. Increased sensitivity to endotoxins in cirrhosis is associated with upregulation of hepatic TLR4, which explains susceptibility to development of ACLF whereas acute liver failure is likely due to direct hepatoxicity. RecAP prevents multiple organ injury by reducing receptor expression and is a potential novel treatment option for prevention of ACLF but not acute liver failure

    Urea cycle dysregulation in non-alcoholic fatty liver disease

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    Background: In non-alcoholic steatohepatitis (NASH), function of urea cycle enzymes (UCEs) may be affected and result in hyperammonemia with risk of disease progression. We aimed to determine whether expression and function of UCEs are altered in a NASH animal model and in non-alcoholic fatty liver disease (NAFLD) patients and whether this is reversible. / Methods: Rats were fed a high-fat, high-cholesterol diet for 10 months to induce NASH and then changed to normal chow to recover. In humans, we obtained liver biopsies from 20 patients with steatosis and 15 NASH patients. Primary rat hepatocytes were isolated and cultured with free fatty acids. We measured the gene and protein expression, the activity of ornithine transcarbamylase (OTC) and ammonia concentrations. Moreover, we assessed the promoter methylation status of OTC and carbamoyl phosphate synthetase (CPS1) in rats, humans and in steatotic hepatocytes. / Results: In NASH animals, gene and protein expression of OTC and CPS1 and activity of OTC were reversibly reduced and hypermethylation of OTC promotor genes was observed. Also in NAFLD patients, OTC enzyme concentration and activity were reduced and ammonia concentrations were increased and more so in NASH. Furthermore, OTC and CPS1 promoter regions were hypermethylated. In primary hepatocytes induction of steatosis was associated with OTC promoter hypermethylation, reduction in the gene expression of OTC and CPS1 and an increase in ammonia concentration in the supernatant. / Conclusion: NASH is associated with a reduction in gene and protein expression, and activity of UCEs resulting in hyperammonemia, possibly through hypermethylation of UCE genes and impairment of urea synthesis. Our investigations describe for the first time a link between NASH, function of UCEs and hyperammonemia providing a novel therapeutic target. / Lay summary: In patients with fatty liver disease, the enzymes that convert nitrogen waste into urea may be affected leading to the accumulation of the toxic substance, ammonia. This accumulation of ammonia can lead to development of scar tissue and risk of progression of disease. In this study, we show that fat accumulation in the liver produces a reversible reduction in the function of these enzymes that are involved in detoxification of ammonia. These data provide potential new targets for therapy of fatty liver disease

    Toll-like receptor 4 is a therapeutic target for prevention and treatment of liver failure

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    Background and aims: Toll-like receptor 4 (TLR4) plays an essential role in mediating organ injury in acute liver failure (ALF) and acute-on-chronic liver failure (ACLF). Here we assess whether inhibiting TLR4 signaling can ameliorate liver failure and serve as a potential treatment. / Material and Methods: Circulating TLR4 ligands and hepatic TLR4 expression was measured in plasma samples and liver biopsies from patients with cirrhosis. TAK-242 (TLR4 inhibitor) was tested in vivo with 10mg/Kg, i.p. in rodent models of ACLF (bile duct ligation + lipopolysaccharide (LPS); carbontetrachloride + LPS) and ALF (Galactosamine + LPS) and in vitro on immortalized human monocytes (THP-1) and hepatocytes (HHL5).. The in vivo therapeutic effect was assessed by coma free survival, organ injury and cytokine release and in vitro by measuring IL6, IL1b or cell injury (TUNEL), respectively. / Results: In patients with cirrhosis, hepatic TLR4 expression was upregulated and circulating TLR4 ligands were increased (p<0.001). ACLF in rodents was associated with a switch from apoptotic cell death in ALF to non-apoptotic forms of cell death. TAK-242 reduced LPS induced cytokine secretion and cell death (p=0.002) in hepatocytes and monocytes in vitro. In rodent models of ACLF, TAK-242 administration improved coma free survival, reduced the degree of hepatocyte cell death in liver p<0.001) and kidneys (p=0.048) and reduced circulating cytokine levels (IL1b p<0.001). In a rodent model of ALF TAK-242 prevented organ injury (p<0.001) and systemic inflammation (IL1b p<0.001). / Conclusion: This study shows that TLR4 signaling is a key factor in the development of both ACLF and ALF and its inhibition improves severity of organ injury and outcome. TAK-242 may be of therapeutic relevance in patients with liver failure

    The role of RIPK1 mediated cell death in acute on chronic liver failure

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    Acute-on-chronic liver failure (ACLF) is characterized predominantly by non-apoptotic forms of hepatocyte cell death. Necroptosis is a form of programmed lytic cell death in which receptor interacting protein kinase (RIPK) 1, RIPK3 and phosphorylated mixed lineage kinase domain-like (pMLKL) are key components. This study was performed to determine the role of RIPK1 mediated cell death in ACLF. RIPK3 plasma levels and hepatic expression of RIPK1, RIPK3, and pMLKL were measured in healthy volunteers, stable patients with cirrhosis, and in hospitalized cirrhotic patients with acutely decompensated cirrhosis, with and without ACLF (AD). The role of necroptosis in ACLF was studied in two animal models of ACLF using inhibitors of RIPK1, necrostatin-1 (NEC-1) and SML2100 (RIPA56). Plasma RIPK3 levels predicted the risk of 28- and 90-day mortality (AUROC, 0.653 (95%CI 0.530–0.776), 0.696 (95%CI 0.593–0.799)] and also the progression of patients from no ACLF to ACLF [0.744 (95%CI 0.593–0.895)] and the results were validated in a 2nd patient cohort. This pattern was replicated in a rodent model of ACLF that was induced by administration of lipopolysaccharide (LPS) to bile-duct ligated rats and carbon tetrachloride-induced fibrosis mice administered galactosamine (CCL4/GalN). Suppression of caspase-8 activity in ACLF rodent model was observed suggesting a switch from caspase-dependent cell death to necroptosis. NEC-1 treatment prior to administration of LPS significantly reduced the severity of ACLF manifested by reduced liver, kidney, and brain injury mirrored by reduced hepatic and renal cell death. Similar hepato-protective effects were observed with RIPA56 in a murine model of ACLF induced by CCL4/GalN. These data demonstrate for the first time the importance of RIPK1 mediated cell death in human and rodent ACLF. Inhibition of RIPK1 is a potential novel therapeutic approach to prevent progression of susceptible patients from no ACLF to ACLF

    Giant atypical carcinoid of the liver with vascular metastases and local sinusoidal invasion: a case report

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    We present the case of a 46 year old woman with a giant, 23-centimeter, atypical carcinoid of the liver. A primary site for this neoplasm could not be identified despite multiple radiographic imaging studies, including a somatostatin scan, and a thorough inspection of the bowel during surgical resection of the lesion. Histologically, the tumor displayed mild cytologic atypia, abundant necrosis, and intravascular metastases, the last feature of which was identified by immunohistochemical markers for chromogranin and synaptophysin. Also described is the unusual sinusoidal infiltration, or "spillage," of tumor cells into the surrounding liver parenchyma, a feature that has not been described as far as we are aware but may suggest an aggressive clinical course. Even though an exact definition of atypia for these lesions apparently does not exist at this point, the multiple atypical features in this case strongly suggest the diagnosis of atypical carcinoid of the liver, thus far an altogether rare and vaguely reported entity. As more cases arise in the medical literature, it may be worthwhile to establish a set of guidelines to define atypical hepatic carcinoids and other gastrointestinal carcinoids, although survivorship data thus far indicates no significant difference in the prognosis between typical versus atypical variants

    Pulmonary thromboembolism secondary to pelvic thrombosis related to giant ovarian tumor

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    Pulmonary thromboembolism (PTE) is one of the major complications in oncologic patients. The incidence of PTE in these cases is 4 to 7 times higher than in non-oncologic patients. Ovarian tumors, specifically those of large sizes, may impair the blood flow through the pelvic veins as tumor pressure over the pelvic vessels increases the incidence of thrombosis. The authors report the case of the unexpected death of a 74-year-old female due to massive pulmonary thromboembolism, associated with an ovarian tumor almost of 15 kg of weight that filled the abdominal and pelvic cavities. The compressive effect on the walls of the pudendal and periuterine veins somehow facilitated the local thrombosis. According to the histological characterization on post-mortem samples, the mass was identified as an \u201catypical proliferative (borderline) mucinous tumor.\u201d The case emphasizes the important association between pulmonary thromboembolism and ovarian tumors
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