Hepatocellular carcinoma may display elevated nestin expression in endothelial cells: experimental study.

CONTEXT AND OBJECTIVE: Nestin, a class VI intermediate filament protein, is highly expressed in the portal mesenchyme and sinusoidal endothelium of the human fetal liver, but scarcely expressed in adult portal vessel endothelium. During experimental liver regeneration, an increased number of nestin-positive parenchymal cells have been observed in the zone adjacent to the Hering canals. These parenchymal cells are regarded as hepatic stem cells or hepatoblasts, which may be involved in hepatocellular carcinogenesis. In the light of recent reports describing nestin-positive parenchymal cells in hepatocellular carcinoma, we aimed to use this tumor type as a positive control for immunohistochemical detection of nestin. DESIGN AND SETTING: Experimental study conducted at a university hospital. METHODS: Hepatocellular carcinoma sections from one case were analyzed for nestin expression by immunohistochemistry using confocal microscopy. RESULTS: Surprisingly, a conspicuous pattern resembling liver sinusoid-like cytoarchitecture was observed upon nestin staining of endothelial cells. CONCLUSIONS: This pattern has not been previously described. The preliminary results shown here suggest that nestin-positive endothelial cells are located in niches of immature or proliferative cells. Moreover, nestin expression in endothelial cells of hepatocellular carcinoma enhances the role of angiogenesis in this tumor type, although the prevalence of this immunohistopathological pattern remains to be determined. Finally, hepatocellular carcinoma is an effective positive control for nestin staining in fluorescent immunohistochemistry.

Small bowel transplantation in outbred rats / Transplante de intestino delgado em ratos não-isogênicos

PURPOSE: To investigate the clinical evolution of orthotopic small bowel transplantation in outbred rats. METHODS: Seventy-two outbred Wistar rats weighting from 250 to 300g were used as donor and recipient in 36 consecutives ortothopic small intestine transplantation without immunosuppression. The graft was transplanted into the recipient using end-to-side aortic and portacaval microvascular anastomosis. Procedure duration, animal clinical course and survival were evaluated. Survival shorter than four days was considered technical failure. Recipients were sacrificed with signs of severe graft rejection or survival longer than 120 days. Necropsies were performed in all recipients to access histopathological changes in the graft. RESULTS: Median time for the procedure was 107 minutes. Six recipients (16.7 percent) presented technical failure. Twenty-seven recipients were sacrificed due to rejection, being nineteen (52.7 percent) between 7th and 15th postoperative day and eight (22.2 percent) between 34th and 47th postoperative day. Graft histology confirmed severe acute cellular rejection in those recipients. Uneventful evolution and survival longer than 120 days without rejection were observed in three recipients (8.3 percent). CONCLUSION: Intestinal transplantation in outbred rats without immunosuppressant regiment accomplishes variable clinical evolution.

OBJETIVO: Investigar a evolução clínica do transplante de intestino delgado ortotópico em ratos não-isogênicos. MÉTODOS: Setenta e dois ratos Wistar não-isogênicos, com peso variando entre 250 e 300g, foram utilizados como doadores e receptores em 36 transplantes ortotópicos de intestino delgado sem regime de imunossupressão. Os enxertos foram implantados nos receptores por meio de anastomose microvascular término-lateral aorta-aorta e porto-cava. A duração do procedimento, evolução clínica dos animais e sobrevida foram avaliados. Sobrevida menor que quatro dias foi considerada falha técnica. Os receptores foram sacrificados quando apresentaram sinais de rejeição grave do enxerto ou sobrevida maior que 120 dias. Necropsias foram realizadas em todos os receptores para avaliar alterações histopatológicas no enxerto. RESULTADOS: O tempo médio para o procedimento foi de 107 minutos. Seis receptores (16,7 por cento) apresentaram falha técnica Vinte e sete receptores (75 por cento) foram sacrificados por rejeição sendo dezenove (52,7 por cento) entre o 7º e 15º dia de pós-operatório e oito (22,2 por cento) entre o 34º e 47º. Análise histopatológica confirmou rejeição celular aguda severa nesses recipientes. Evolução sem complicações e sobrevida maior que 120 dias sem sinais de rejeição foi observada em três receptores (8,3 por cento). CONCLUSÃO: O transplante de intestino delgado ortotópico em ratos Wistar não-isogênicos sem regime de imunossupressão apresenta evolução clínica variada.

Small bowel transplantation in outbred rats.

PURPOSE: To investigate the clinical evolution of orthotopic small bowel transplantation in outbred rats. METHODS: Seventy-two outbred Wistar rats weighting from 250 to 300g were used as donor and recipient in 36 consecutives ortothopic small intestine transplantation without immunosuppression. The graft was transplanted into the recipient using end-to-side aortic and portacaval microvascular anastomosis. Procedure duration, animal clinical course and survival were evaluated. Survival shorter than four days was considered technical failure. Recipients were sacrificed with signs of severe graft rejection or survival longer than 120 days. Necropsies were performed in all recipients to access histopathological changes in the graft. RESULTS: Median time for the procedure was 107 minutes. Six recipients (16.7%) presented technical failure. Twenty-seven recipients were sacrificed due to rejection, being nineteen (52.7%) between 7(th) and 15(th) postoperative day and eight (22.2%) between 34(th) and 47(th) postoperative day. Graft histology confirmed severe acute cellular rejection in those recipients. Uneventful evolution and survival longer than 120 days without rejection were observed in three recipients (8.3%). CONCLUSION: Intestinal transplantation in outbred rats without immunosuppressant regiment accomplishes variable clinical evolution.

Influence of chronic liver disease on coronary atherosclerosis vulnerability features.

INTRODUCTION: A lower incidence of acute myocardial infarction was reported in patients with chronic liver disease. OBJECTIVE: To analyze the impact of chronic liver disease on characteristics associated with vulnerability of human coronary artery atherosclerotic plaques. METHODS: One hundred fourteen hearts were collected from 3 groups of individuals: A--38 chronic liver disease patients who died while on the waiting list for liver transplantation; B--38 individuals who died of natural causes; and C--38 individuals who died of accidental causes. The most obstructed portion of the initial 2-cm segment of coronary arteries was histologically evaluated regarding to plaque area, luminal area, inflammation, percentage of fat, and total vessel area. RESULTS: The mean age (years) and male frequency in groups A, B and C were, respectively, 52+/-9 and 79%; 52+/-11 and 71%; and 54+/-18 and 89%. The mean area of the plaque and the incidence of severe plaque inflammation in group A were significantly lower (4.2+/-3.2; 13.2%) than those in the other two groups (6.6+/-4.3; 84.2%, and 6.3+/-4.4; 52.6%) p<0.01. The cross-sectional vessel measures were not statistically different regarding to vessel area (10.5+/-4.6; 12.1+/-4.6; 13.0+/-4.4) p=0.08, luminal obstruction (45%+/-15%; 60%+/-20%; 53%+/-20%) p=0.07, and fat area in the plaque (16%+/-17%; 30%+/-24%; 18%+/-18) p=0.37. In conclusion, compared with the general population, chronic liver disease patients have coronary arteries with smaller intimal plaque and less vessel inflammation. These findings favor the concept that hepatic disease patients are less prone to develop complicated coronary atherosclerosis.