Using an immunohistochemical study and an immunoblot analysis, the expression of cellular oncogenes of the human salivary glands such as c-myc, ras p21, and p53 tumor-suppressor gene in pleomorphic adenomas and its malignant form, carcinoma in pleomorphic adenomas was examined to evaluate a differential biological significance, in comparison with that in normal salivary gland tissues. Immunohistochemically, the c-myc product was detected in 42% of the pleomorphic adenomas and in 56% of the carcinomas in pleomorphic adenoma. The ras p21 expression was observed in 24% of pleomorphic adenomas, and in 50% of carcinomas in pleomorphic adenoma. The p53 protein was detected in 18% of the pleomorphic adenomas and in 67% of the carcinomas in pleomorphic adenoma. Although there was no significant difference between the benign and malignant forms for the expression of c-myc, a statistical significance in ras p21 and p53 expression was found between the pleomorphic adenoma and its malignant form (P < 0.05) and P < 0.001, respectively). An immunoblotting assay clearly demonstrated the expression of c-myc and p53 gene products in both the benign and malignant forms of the pleomorphic adenoma, and that of ras p21 in the malignant form. These results indicate that activation of c-myc and ras p21 proto-oncogenes and the involvement of p53 mutation may play important roles in the malignant transformation of salivary gland pleomorphic adenoma.

Adenoma, Pleomorphic↗

PubMedDate not supplied

Enterovirus RNA replication in cases of dilated cardiomyopathy: light microscopic in situ hybridization and virological analyses of myocardial specimens obtained at partial left ventriculectomy.

OBJECTIVE: Recently, attention has been focused on enteroviral infection of the heart in the genesis of dilated cardiomyopathy (DCM). To determine the location of enteroviral RNA in the myocardium, we performed light microscopic in situ hybridization (ISH) and virological analyses of myocardial specimens obtained at partial left ventriculectomy (PLV). METHODS: Posterolateral walls of the left ventricle from 26 DCM patients were examined. Myocardial specimens were tested for the presence of enteroviral genomes by polymerase chain reaction (PCR). We selected two age-matched groups (10 patients each) in which enteroviruses were either present (EV-plus group) or not (EV-minus group). For both groups, we examined in situ localization of enteroviral RNA in the myocardium by ISH. RESULTS: In PCR studies, both sense and antisense enteroviral RNA were detected in the myocardium of seven patients in the EV-plus group. The presence of this RNA indicates active viral replication in the myocardium. Five of seven patients who exhibited both sense and antisense enteroviral RNA died early after surgery. On ISH, three patients had evidence of active replication of enteroviral genomes. Viral genomes were present in myocardial lesions, especially in endocardial sites. Viral signals were found in degenerating myocardial cells, interstitial inflammatory cells, and endothelial cells of small vessels. These positive signals were not detected in the myocardium of the EV-negative group. CONCLUSIONS: We detected both sense and antisense enteroviral RNA in various myocardial lesions. This suggests that active enteroviral replication plays a role in the development of myocardial lesions in DCM patients. Active viral replication appears to be a prognostic factor for DCM after PLV. Further study of active viral replication in myocardial lesions will provide information useful for evaluating different therapeutic strategies for DCM.

Adolescent↗

PubMedDate not supplied

Expression of alpha-smooth muscle actin in small bronchioloalveolar adenocarcinoma of the lung: assessment and comparison with noguchi criteria.

The Noguchi criteria are useful in assessing the prognosis of patients with small lung adenocarcinoma. Although there is a significant difference in prognosis between type A or B and type C, it is difficult in some cases to distinguish these types accurately by microscopy. In this study, we used immunohistochemistry to examine alpha-smooth muscle actin (alpha-SMA) produced by active fibroblasts in 25 pulmonary adenocarcinomas less than 2 cm in diameter. Eleven of type C (61%) showed positive staining for alpha-SMA, whereas no positive cases were seen in type A or B. The incidence of cancerous blood vessel and lymphatic invasion were significantly higher in alpha-SMA positive cases than in negative cases, and the positive cases showed poorer prognosis. These findings indicate that immunohistochemical detection of alpha-SMA is useful and essential for histological typing by the Noguchi criteria.

Actins↗