RESUMEN
The distinction of hepatocellular carcinoma (HCC) from metastatic tumor in the liver often presents a diagnostic challenge that carries significant impact on prognostication and therapy. The number of diagnostically useful immunohistochemical markers of hepatocytes is limited to hepatocyte paraffin antigen (HepPar-1), polyclonal carcinoembryonic antigen, and CD10, with alpha-fetoprotein and glypican-3 labeling HCCs. Arginase-1 (Arg-1) is a binuclear manganese metalloenzyme that catalyzes the hydrolysis of arginine to ornithine and urea. We used immunohistochemistry to compare the sensitivity of Arg-1 to that of HepPar-1 in 151 HCCs. We found that the overall sensitivities of Arg-1 and HepPar-1 are 96.0% and 84.1%, respectively. The sensitivities of Arg-1 in well, moderately, and poorly differentiated HCCs are 100%, 96.2%, and 85.7%, respectively, whereas, in comparison, HepPar-1 demonstrated sensitivities of 100%, 83.0%, and 46.4% for well, moderately, and poorly differentiated tumors, respectively. There were no HCCs in our study that were reactive for HepPar-1 but nonreactive for Arg-1. We also examined Arg-1 expression in nonhepatocellular tumors, including many that are potential mimics of HCC (renal cell carcinomas, neuroendocrine tumors, melanomas, gastric adenocarcinomas, and adrenocortical carcinomas) and found that only 2 non-HCC tumors were reactive for Arg-1. Arg-1 represents a sensitive and specific marker of benign and malignant hepatocytes that may ultimately prove to be a useful diagnostic tool in routine surgical pathology practice.
Asunto(s)
Arginasa/análisis , Biomarcadores de Tumor/análisis , Carcinoma Hepatocelular/enzimología , Hepatocitos/enzimología , Inmunohistoquímica , Neoplasias Hepáticas/enzimología , Brasil , Carcinoma Hepatocelular/patología , Diferenciación Celular , Hepatocitos/patología , Humanos , Neoplasias Hepáticas/patología , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Análisis de Matrices Tisulares , Estados UnidosRESUMEN
Primary cultures of embryonic murine neurons and newborn mouse astrocytes were inoculated with West Nile virus (WNV) strain NY385-99 to compare the pathogenesis of WNV infection in these types of CNS cells. Two different outcomes were observed. WNV infection in the neurons was rapidly progressive and destructive; within 5 days, all of the neurons were destroyed through apoptosis. WNV infection in the astrocytes evolved more slowly and did not seem to be highly lethal to the cells. The infected astrocytes continued to produce infectious virus (10(4.6)-10(6.5) PFU/mL) for 114 days, in a permissive, persistent infection. During this period, WNV antigen could be shown in the cytoplasm of the infected astrocytes by immunocytochemical assay, transmission electron microscopy of ultrathin sections, and in the cell culture medium by complement fixation test. Our results with this in vitro experimental murine cell model indicate that astrocytes can develop chronic or persistent infection with WNV, suggesting that these cells may play a role in the maintenance of WNV in the CNS.
Asunto(s)
Astrocitos/virología , Neuronas/virología , Virus del Nilo Occidental/fisiología , Animales , Antígenos Virales/análisis , Apoptosis , Astrocitos/ultraestructura , Células Cultivadas , Pruebas de Fijación del Complemento , Efecto Citopatogénico Viral , Pruebas de Hemaglutinación , Inmunohistoquímica , Etiquetado Corte-Fin in Situ , Ratones , Ratones Endogámicos ICR , Neuronas/ultraestructura , Replicación Viral , Virus del Nilo Occidental/inmunología , Virus del Nilo Occidental/patogenicidad , Virus del Nilo Occidental/ultraestructuraRESUMEN
Samples of laboratory propagated Venezuelan equine encephalitis (VEE), West Nile (WN), and yellow fever (YF) viruses were blotted onto filter paper discs, air-dried, and stored at room temperature. At regular intervals over a 90-day period, the dried virus samples were eluted, tested for infectivity by culture and titration in Vero cells, and examined for viral RNA by a reverse transcriptase-polymerase chain reaction. The VEE, WN, and YF viral RNA was detected throughout the 90-day period in all samples examined. Infectious VEE virus could be recovered for up to 40 days; WN and YF viruses were cultured in Vero cells for up to 60 and 90 days, respectively. The results of this study demonstrate that viral nucleic acids and infectious virus can be recovered from arbovirus samples air-dried on filter paper and stored at room temperature for a month or more after collection. This procedure offers a simple and inexpensive method for collecting arbovirus field specimens and transporting them to diagnostic laboratories.