RESUMO
BACKGROUND AND AIM: Fatty infiltration and fibrosis are major issues in chronic liver disease. Recent reports suggest a role for the endocannabinoid system in these processes. AIM: To characterize localization and expression of CB2 in normal liver and nonalcoholic fatty liver. METHODS: We studied 64 liver biopsies: eight were considered normal; 56 had a diagnosis of nonalcoholic fatty liver disease (NAFLD); 32 with nonalcoholic steatosis and 24 nonalcoholic steatohepatitis (NASH). CB2 immunolocalization was studied in 38 samples in paraffin blocks using immunohistochemistry, and a computerized semiquantitative analysis was carried out. CB2 mRNA expression was assessed through RT-PCR in 26 frozen liver samples and the ratio CB2/beta-actin was used to evaluate differences between groups. Statistical analysis was performed with central tendency measures and the Mann-Whitney U-test. We considered as significant differences those with a P-value <0.05. RESULTS: Neither parenchymal nor nonparenchymal cells in normal liver tissue react towards anti-CB2 antibodies. All the samples from patients with steatosis and nonalcoholic steatohepatitis showed hepatocellular immunoreactivity. Cholangiocytes were positive only in the NAFLD group. Normal liver tissue showed a normalized CB2/beta-actin ratio of 0.001+/-0.01, steatosis 6.52+/-17.3 (P=0.05 vs normal) and NASH 6.49+/-12.2 (P=0.06 vs normal and P=0.6 vs steatosis). CONCLUSION: CB2 receptors are expressed by hepatocytes in nonalcoholic fatty liver disease but not in normal liver.
Assuntos
Fígado Gorduroso/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Fígado Gorduroso/patologia , Hepatite/metabolismo , Hepatite/patologia , Humanos , Imuno-Histoquímica , Fígado/metabolismo , Fígado/patologia , Estudos Prospectivos , RNA Mensageiro/metabolismo , Receptor CB2 de Canabinoide/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Distribuição TecidualRESUMO
BACKGROUND: Anaplastic thyroid carcinoma (ATC) is a highly aggressive tumor with a median survival rate of 6 months. AIM: To analyze presentation, treatment, morphology, immunohistochemistry, and nuclear DNA analysis of a cohort of patients with ATC. PATIENTS AND METHODS: Twelve patients with ATC (11 female) with a mean age of 65 years were seen at our hospital from 1970-1995. The data were obtained from the clinical records and the morphology, immunohistochemic studies and DNA pattern were performed in slides obtained from archival specimens. RESULTS: Previous or coexisting thyroide disease was documented in 10 patients (9 multinodular goiters and one Grave's). The most frequent presentation was a rapidly growing tumor associated with dysphagia, cervical pain, hoarseness and dyspnea. A cold thyroid nodule was detected by thyroid scan in 10 patients. The most frequent subtype was the spindle cell variety. Papillary thyroid carcinoma coexisted in eight cases, two of them corresponded to the tall cell variant. Reactivity for S-100 protein and vimentin was studied in six patients: all were positive for S-100 protein and vimentin, 5/6 for epithelial membrane antigen, half for carcinoembriogenic antigen, 2/6 for thyroglobulin and calcitonin, and one for neuronal specific enolase. These six tumors showed a diploid DNA pattern. Tumor resection was achieved in 2/11 and none survived six years after diagnosis. CONCLUSIONS: ATC is a highly aggressive tumor coexisting with thyroid pathologies. Spindle cell variant is the most frequent with positive reactivity for S-100 protein, vimentin and epithelial membrane antigen. Most tumors have a diploid DNA content.