146 research outputs found
Elevated transaminases as a predictor of coma in a patient with anorexia nervosa: a case report and review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Liver injury is a frequent complication associated with anorexia nervosa, and steatosis of the liver is thought to be the major underlying pathology. However, acute hepatic failure with transaminase levels over 1000 IU/mL and deep coma are very rare complications and the mechanism of pathogenesis is largely unknown.</p> <p>Case presentation</p> <p>A 37-year-old Japanese woman showed features of acute liver failure and hepatic coma which were not associated with hypoglycemia or hyper-ammonemia. Our patient's consciousness was significantly improved with the recovery of liver function and normalization of transaminase levels after administration of nutritional support.</p> <p>Conclusions</p> <p>Our case report demonstrates that transaminase levels had an inverse relationship with the consciousness of our patient, although the pathogenesis of coma remains largely unknown. This indicates that transaminase levels can be one of the key predictors of impending coma in patients with anorexia nervosa. Therefore, frequent monitoring of transaminase levels combined with rigorous treatment of the underlying nutritional deficiency and psychiatric disorder are necessary to prevent this severe complication.</p
RegNetB: Predicting Relevant Regulator-Gene Relationships in Localized Prostate Tumor Samples
<p>Abstract</p> <p>Background</p> <p>A central question in cancer biology is what changes cause a healthy cell to form a tumor. Gene expression data could provide insight into this question, but it is difficult to distinguish between a gene that causes a change in gene expression from a gene that is affected by this change. Furthermore, the proteins that regulate gene expression are often themselves not regulated at the transcriptional level. Here we propose a Bayesian modeling framework we term RegNetB that uses mechanistic information about the gene regulatory network to distinguish between factors that cause a change in expression and genes that are affected by the change. We test this framework using human gene expression data describing localized prostate cancer progression.</p> <p>Results</p> <p>The top regulatory relationships identified by RegNetB include the regulation of RLN1, RLN2, by PAX4, the regulation of ACPP (PAP) by JUN, BACH1 and BACH2, and the co-regulation of PGC and GDF15 by MAZ and TAF8. These target genes are known to participate in tumor progression, but the suggested regulatory roles of PAX4, BACH1, BACH2, MAZ and TAF8 in the process is new.</p> <p>Conclusion</p> <p>Integrating gene expression data and regulatory topologies can aid in identifying potentially causal mechanisms for observed changes in gene expression.</p
Upregulation of Hemoglobin Expression by Oxidative Stress in Hepatocytes and Its Implication in Nonalcoholic Steatohepatitis
Recent studies revealed that hemoglobin is expressed in some non-erythrocytes and it suppresses oxidative stress when overexpressed. Oxidative stress plays a critical role in the pathogenesis of non-alcoholic steatohepatitis (NASH). This study was designed to investigate whether hemoglobin is expressed in hepatocytes and how it is related to oxidative stress in NASH patients. Analysis of microarray gene expression data revealed a significant increase in the expression of hemoglobin alpha (HBA1) and beta (HBB) in liver biopsies from NASH patients. Increased hemoglobin expression in NASH was validated by quantitative real time PCR. However, the expression of hematopoietic transcriptional factors and erythrocyte specific marker genes were not increased, indicating that increased hemoglobin expression in NASH was not from erythropoiesis, but could result from increased expression in hepatocytes. Immunofluorescence staining demonstrated positive HBA1 and HBB expression in the hepatocytes of NASH livers. Hemoglobin expression was also observed in human hepatocellular carcinoma HepG2 cell line. Furthermore, treatment with hydrogen peroxide, a known oxidative stress inducer, increased HBA1 and HBB expression in HepG2 and HEK293 cells. Importantly, hemoglobin overexpression suppressed oxidative stress in HepG2 cells. We concluded that hemoglobin is expressed by hepatocytes and oxidative stress upregulates its expression. Suppression of oxidative stress by hemoglobin could be a mechanism to protect hepatocytes from oxidative damage in NASH
Intervention with a caspase-1 inhibitor reduces obesity-associated hyperinsulinemia, non-alcoholic steatohepatitis and hepatic fibrosis in LDLR-/-.Leiden mice
Non-alcoholic steatohepatitis (NASH) is a serious liver condition, closely associated with obesity and insulin resistance. Recent studies have suggested an important role for inflammasome/caspase-1 in the development of NASH, but the potential therapeutic value of caspase-1 inhibition remains unclear. Therefore, we aimed to investigate the effects of caspase-1 inhibition in the ongoing disease process, to mimic the clinical setting. To investigate effects of caspase-1 inhibition under therapeutic conditions, male LDLR-/-.Leiden mice were fed a high-fat diet (HFD) for 9 weeks to induce a pre-diabetic state before start of treatment. Mice were then continued on HFD for another 12 weeks, without (HFD) or with (HFD-YVAD) treatment with the caspase-1 inhibitor Ac-YVAD-cmk (40 mg kg(-1) per day). Nine weeks of HFD feeding resulted in an obese phenotype, with obesity-associated hypertriglyceridemia, hypercholesterolemia, hyperglycemia and hyperinsulinemia. Treatment with Ac-YVAD-cmk did not affect further body weight gain or dyslipidemia, but did attenuate further progression of insulin resistance. Histopathological analysis of livers clearly demonstrated prevention of NASH development in HFD-YVAD mice: livers were less steatotic and neutrophil infiltration was strongly reduced. In addition, caspase-1 inhibition had a profound effect on hepatic fibrosis, as assessed by histological quantification of collagen staining and gene expression analysis of fibrosis-associated genes Col1a1, Acta2 and Tnfa. Intervention with a caspase-1 inhibitor attenuated the development of NASH, liver fibrosis and insulin resistance. Our data support the importance of inflammasome/caspase-1 in the development of NASH and demonstrate that therapeutic intervention in the already ongoing disease process is feasibl
Proliferating cell nuclear antigen and Ki-67 labeling in hepatocellular nodules: a comparative study
Aims/Background The morphologic differential diagnosis of hepatocellular
nodules (HCN) is frequently difficult and objective criteria would be
useful in the categorization of such lesions. This study evaluated the
proliferative activity of HCN, including regenerative, macroregenerative
(MRN), cirrhotic, dysplastic, and hepatocellular carcinoma (HCC), as
well as intranodular cytologic changes such as bile-stained hepatocytes,
eosinophilia, clear, large cell (LCC) and small cell (SCC) change, by
comparing the cellular density (CD), labeling indices (LI) and density
(DP) of two proliferation markers. Methods: Routinely processed tissue
sections from 45 HCN from 17 adult liver explants were studied by
immunohistochemistry for PCNA and Ki-67 (MIB-1)I Results: A progressive
increase in LI from regenerative to dysplastic nodules to HCC was
observed with both proliferation markers. The values of the two markers
were significantly correlated (p<0.001). CD PCNA and MIB-1 LI and DP
values were significantly lower in regenerative compared to dysplastic
nodules or HCC. MRNs had lower PCNA and MIB-1 LI and DP than
regenerative nodules, but similar CD There were no statistically
significant differences in CD PCNA, and MIB-1 LI and DP between
dysplastic nodules and HCC, comparing high versus low grade dysplasia,
or HCC smaller than 2 cm with those larger than 2 cm. The CD and
proliferation indices LI and DP were higher in HCC than in the
surrounding nonneoplastic parenchyma. Lesions with clear cell,
eosinophilic and large cell change had CD, PCNA and MIB-1 indices
similar to those of regenerative: nodules, while these were lower in
bile-stained hepatocellular lesions (p<0.01). SCC showed CD, PCNA and
MIB-1LI and DP similar to HCC and higher than surrounding regenerative
lesions (p<0.003). Conclusions: Our results suggest that PCNA and MIB-1
values are closely correlated in HCN. Regenerative nodules are
characterized by low cellular proliferation, while dysplastic nodules
are usually highly proliferative lesions and may represent an early
stage in hepatocarcinogenesis. Hepatocellular lesions characterized by
bile stained hepatocytes, eosinophilic, clear and large cell change have
low proliferation rates and may not be significant for the development
of malignancy
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