Incidence of p53 and Ha-ras gene mutations in chemically induced rat mammary carcinomas.

To determine whether p53 alterations, which are frequent in human breast cancers, are also common in rat mammary tumors, we examined 40 tumors from 24 rats treated with 7,12-dimethylbenz[a]anthracene (DMBA) and 34 tumors from 14 rats treated with N-nitroso-N-methylurea (NMU) (an N-nitroso compound). DMBA and NMU are known genotoxic mutagens. The entire coding regions of the p53 and Ha-ras genes were examined for mutations by polymerase chain reaction single-strand conformational polymorphism analysis and by direct sequencing. One of the 40 DMBA-induced mammary tumors had a p53 mutation, a single-base substitution (AGC-->GGC) at codon 307, resulting in an amino-acid change from Ser to Gly. No mutations were found in NMU-induced tumors. The incidence of Ha-ras gene mutation was 79% (27 of 34) at codon 12 in the NMU group and 23% (nine of 40) at codon 61 in the DMBA group. Thus, p53 mutation, in contrast to Ha-ras mutation, did not seem to be a prerequisite for carcinogenesis in chemically induced rat mammary tumors.

Immunohistochemical detection of truncated APC protein in sporadic human colorectal adenomas and adenocarcinomas.

Mutations of the APC gene frequently occur in sporadic forms of colorectal adenomas and adenocarcinomas. Phenotypically, the vast majority of these mutations result in the truncation of the APC protein. To demonstrate the defective APC gene product in human colorectal tumors, rabbit region-specific antisera raised against the APC protein of amino acid sequences between 371 and 390 (SPI) and between 1821 and 1840 (SP3) were used to exhibit the truncated APC protein. In all, 86 lesions from 67 cases of sporadic adenoma and adenocarcinoma were examined; abnormal staining patterns were distinguished in 43 lesions (50%); the incidence of abnormalities was not significantly different between adenomas and carcinomas. The majority, 75% exhibited epitopic change with the SPI-positive and SP3-negative phenotype (type P1), and 25% exhibited neither of these phenotypes (type P2). The staining pattern in all lesions was uniform, and studies of carcinomas arising in adenomas showed the same pattern of staining. These findings supported the view that the APC lesion is a very early event in colorectal carcinogenesis. Furthermore, this simple immunohistochemical approach demonstrated that different adenomas from the same patient showed different staining patterns.

Two long-term survivors after microwave coagulation therapy for hepatocellular carcinoma: a case report.

We present two long-term survivors who underwent microwave coagulation therapy (MCT) for hepatocellular carcinoma (HCC). One patient was a 55-yr-old man having a solitary HCC of 25 mm in diameter associated with advanced liver cirrhosis. He underwent MCT instead of hepatic resection because he developed bleeding tendency during surgery. The other patient was a 78-yr-old woman having a 7 cm tumor in segment II and a 15 mm satellite lesion in segment IV. Because manipulation of the left hepatic lobe caused prolonged hypotension, only the main tumor was resected. The satellite lesion was treated with MCT. In both cases, tumors and surrounding liver parenchyma were widely coagulated. Postoperative courses were uneventful. The coagulated area shrank subsequently after surgery. Both patients are alive 39 and 55 months after MCT without tumor recurrence. This report proves that MCT is a curative treatment and an alternative to hepatic resection in selected patients with HCCs.

[A case of chylomediastinum following open heart surgery via median sternotomy].

The case was a 17-year-old woman on whom open heart surgery was performed for ASD. Anterior mediastinal drainage alone revealed chyloid liquid, leading to diagnosis as chylomediastium. Ramification of thoracic duct and direct injuries of thymus and lymphoduct were presumed to be responsible for the occurrence of this complication. Operative treatment was positively performed because of its unimprovement by conservative treatment. Re-operation led to its healing in a comparatively short period of time. Idea of disease, cause of occurrence, and plan of treatment of this complication were examined for reporting below.