Biomedical subjects

M Asamoto

Publications and source records attributed to M Asamoto.

94 records · Page 6Linked to original sources

PubMed1985

Comparison of the various forms of glutathione S-transferase with glucose-6-phosphate dehydrogenase and gamma-glutamyltranspeptidase as markers of preneoplastic and neoplastic lesions in rat kidney induced by N-ethyl-N-hydroxyethylnitrosamine.

Alterations in gamma-glutamyl transpeptidase (gamma-GT) and alkaline phosphatase (ALP) activities and binding of specific antibodies to glucose-6-phosphate dehydrogenase (G6PDH), gamma-GT and the A, B, C, D, and P forms of glutathione S-transferase (GST-A, -B, -C, -D, and -P, respectively) in preneoplastic and neoplastic lesions induced by N-ethyl-N-hydroxyethylnitrosamine (EHEN) in the rat kidney were investigated. Morphologically the lesions were of basophilic type and were classified either as altered tubules or adenomas, the latter being further subdivided into microadenomas and adenomas depending on size and the presence of compression. The fact that all lesions demonstrated only weak (or negative) gamma-GT, ALP and GST-B stainings, all of which are normally evident in proximal tubules, and also the occasional finding of cells bearing a periodic acid-Schiff-positive apical brush border within altered tubules strongly positive for GST-A, indicated their histogenesis from the proximal segment of the nephron. Thus a directed shift to a phenotype opposite to that observed in the cells of origin was demonstrated. Comparison of phenotype within the range of EHEN-induced lesions strongly suggested putative preneoplastic character for the altered tubules. Transition to adenomas appeared to be correlated with progressive loss of GST-A and moderate to slight increase of G6PDH.

Adenoma↗

PubMedDate not supplied

Inhibition of glutathione S-transferase P type-positive foci development by linolic acid hydroperoxides and their secondary oxidative products in a rat in vivo mid-term test for liver carcinogens.

The effects of linolic acid hydroperoxides (product A) and secondary oxidative products of product A (product B), were examined in an in vivo mid-term test for hepatocarcinogens or hepatopromoters in rats. The number of placental type of glutathione S-transferase (GST-P)-positive foci of the liver was significantly reduced in rats given diethylnitrosamine (DEN) followed by products A (4.64 +/- 1.09, P less than 0.05) or B (3.62 +/- 1.65, P less than 0.01) as compared to the controls given carcinogen alone (6.31 +/- 2.82). The area of GST-P positive foci was also significantly reduced in rats given DEN followed by product B (0.30 +/- 0.21, P less than 0.05) as compared to the controls (0.47 +/- 0.23). These results suggest that linolic acid hydroperoxides or their secondary oxidative products are not hepatocarcinogens and rather may possess inhibitory potential for liver carcinogenesis.

Animals↗

PubMedDate not supplied

Metastasizing neuroblastomas from taste buds in rats transgenic for the Simian virus 40 large T antigen under control of the probasin gene promoter.

During establishment of a prostate cancer model in rats transgenic for the Simian virus 40 large T antigen, under control of the probasin gene promoter, with protein expression specific to the prostate, tongue, and spinal cord, undifferentiated small round cell tumors were frequently observed. Extensive examination of tongues of the transgenic rats, despite a macroscopically normal appearance, revealed the tumors to have come from taste buds of the papilla circumvallata and papilla foliata. The lesions were positive for the SV40 T antigen, PGP9.5 (ubiquitin C-terminal hydrolase), and synaptophysin, neuron and neuroendocrine markers. Morphologically and immunohistochemically, the tumors were diagnosed as neuroblastomas, considering the neuroepithelial origin. Histologically identical tumor cells in the spinal cord and lung were observed only in the rats with deeply invading tongue tumors, suggesting that metastasis from the tongue tumors had occurred. Castration or supplementation with testosterone propionate did not alter tumor development, indicating the tumors to be androgen-independent. These results clearly show that taste buds can give rise to metastasizing neuroblastomas.

Androgen-Binding Protein↗

PubMedDate not supplied

Immunohistochemical evaluation of nonspecific cross reactive antigen and carcinoembryonic antigen (CEA) in urinary bladder carcinoma.

The immunohistochemical expression of CEA in formalin-fixed paraffin sections in urinary bladder carcinomas was compared to the use of polyclonal anti-CEA antiserum (P-CEA), NCA-absorbed anti-CEA (NCA-aCEA) and monoclonal antibody to CEA (M-CEA). The urinary bladder carcinomas examined consisted of 19 cases of transitional cell carcinoma (TCC) and 7 cases of squamous cell carcinoma (SCC). Both TCC and SCC were positive for CEA with the use of P-CEA and NCA-aCEA, and the degree of staining was markedly dependent on the grade of malignancy in TCC. However, the reaction to M-CEA was generally very weak or negative in TCC and SCC. In SCC, the staining reaction was confined to keratinized foci and not found in all malignant tumour cells when polyclonal CEA antiserum was used. These findings indicate that positive reactions seen with conventional CEA antibodies (P-CEA and NCA-aCEA) are possibly related to NCA and that urinary bladder carcinoma may contain relatively more NCA than true CEA.

Adenocarcinoma↗