PubMed Health⌕ Search

Biomedical subjects

T Seto

Publications and source records attributed to T Seto.

At least 91 records · Page 5Linked to original sources
PubMed1989

So-called intracranial germ cell tumours: personal experiences and a theory of their pathogenesis.

We investigated 110 cases of intracranial germ cell tumours (up to the end of 1986), 56% of which showed monotypic histological patterns and 44% were shown to be mixed tumours. All these cases underwent surgery followed by radiation and/or chemotherapy. All cases of choriocarcinoma and embryonal carcinoma died within 2 yr: cases of endodermal sinus tumour also showed poor results (4 yr survival rate was 12.5%). Mature teratoma had a 5 yr survival rate (5YSR) and a 10 yr survival rate (10YSR) of 78.3% each: immature teratoma showed a 5YSR of 44.9%. Two-cell pattern tumours (PTC) showed a 5YSR of 85.8% and a 10YSR of 82.4%. They (PTC) can be divided into two groups (i) germinoma and (ii) pinealoma of pineal parenchyma origin (pineocytoma with lymphocytic infiltration) on the basis of the difference in the tumour cell-stroma relationship and also placental alkaline phosphatase stain. In the pineal region, 70% of PTC belonged to the category of pinealoma and in the suprasellar region, 92% of PTC were germinoma. Germinoma showed a 5YSR of 91.4% and a 10YSR of 91.4%, whereas those of the pinealoma were 78.2% and 68.4% respectively. This suggests that the biological characteristics of germinoma and pinealoma may be different. All these results may bring into question the validity of the germ cell theory, since germinoma, which should be the most undifferentiated according to the theory, was the most benign and choriocarcinoma and endodermal sinus tumour, which should be the most differentiated, were the most malignant in the follow-up study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Synthesis and alpha-glucosidase-inhibiting activity of a new alpha-glucosidase inhibitor, 4-O-alpha-D-glucopyranosylmoranoline and its N-substituted derivatives.

Various N-substituted derivatives of 4-O-alpha-D-glucopyranosylmoranoline have been synthesized, and their inhibitory activities against rabbit sucrase and maltase have been measured, as well as their effects on postprandial hyperglycemia in the sucrose-loaded rat, 4-O-alpha-D-Glucopyranosylmoranoline was also shown to have potent hypoglycemic activity in starch-loaded dogs.

1-Deoxynojirimycin↗
PubMed1989

Immunohistochemical evidence for the production of tumor necrosis factor by murine MH134 tumor cells as well as monocytes in tumor lesions after systemic administration of a polyalcoholized mannoglucan from Microellobosporia grisea.

The endogenous production of tumor necrosis factor (TNF) by tumor tissues was examined. MH134 tumor cells as well as monocytes in MH134 tumor tissues produced TNF after systemic administration of a polyalcoholized mannoglucan (MGA) from Microellobrosporia grisea as shown by the indirect immunofluorescence technique. MH134 tumor cells also produced TNF when stimulated with lipopolysaccharide in vitro. These results suggest that regression of MH134 hepatoma can be ascribed to TNF produced not only by monocytes but also by tumor cells themselves in the tumor tissue.

Animals↗
PubMed1988

Inhibitory effects of synthetic acidic retinoid and polyprenoic acid on the development of hepatoma in rats induced by 3'-methyl-N, N-dimethyl-4-aminoazobenzene.

A study was conducted to investigate the inhibitory effects of acidic retinoid (trimethylmethoxyphenyl analog of retinoic acid ethylester or TMMP) and polyprenoic acid (3,7,11,15-tetramethyl-2,4,6,10,14-hexadecapentaenoic acid or E-5166) on the development of hepatoma induced by 3'-methyl-N, N-dimethyl-4-aminoazobenzene (3'-MeDAB) in rats. Morphometric analysis of liver specimens was employed to evaluate the antitumor effects of the compounds in detail, and revealed significant decreases in the number and area of tumors in the TMMP- and E-5166-treated groups. As for adverse effects, retarded growth and marked hypertriglyceridemia were observed only in TMMP-treated rats. During the hepatocarcinogenesis, cellular retinoid-binding protein, F-type or CRBP(F) and cellular retinoic acid-binding protein or CRABP newly appeared in the tumor tissue, particularly in hyperplastic nodules which are the precancerous state of hepatoma. These results suggest that the polyprenoic acid is a good candidate for clinical chemoprevention of hepatoma, targetting its precancerous stage when intracellular receptors for acidic retinoid have emerged.

Animals↗
PubMed1985

A cell line from pleomorphic adenoma of the rat salivary gland.

Pleomorphic adenoma of rat salivary gland is extremely rare, and culture of cells obtained from rat salivary gland tumors has not been reported. We have established a long-term cell line from a pleomorphic adenoma of a Sprague-Dawley rat submaxillary gland. The pleomorphic adenoma was composed of oval or spindle-shaped cells occasionally forming a small duct. Alcian blue-positive intercellular matrices, consisting mainly of glycosaminoglycans, were abundant. The cultured cells showed characteristics similar to those of the original tumor. This cell line should be useful for biological and biochemical studies of glycosaminoglycan-synthesis of pleomorphic adenoma cells.

Adenoma, Pleomorphic↗
PubMed1985

Correlation of androgen receptors with histological differentiation in human endometrial carcinomas.

Primary endometrial carcinomas from 35 non-treated patients were investigated by measurement of androgen receptors in the tumor cytosols. Receptor analysis was done with a labelled synthetic androgen, methyltrienolone 3H-R1881 and triamcinolone acetonide, and dextran-coated charcoal absorption. The concentrations of androgen receptors in the endometrial carcinomas were, in decreasing order: highly-differentiated tumors, 15.7 +/- 1.8 (fmol/mg protein, mean +/- SE) (number of cases, 21); moderately differentiated tumors, 4.6 +/- 1.6 (n = 7); poorly differentiated tumors, undetectable in 7 out of 8 cases. Highly-differentiated tumors contained a much greater concentration of receptors than the two less differentiated ones. One highly-differentiated endometrial carcinoma with pyometra virtually lacked the receptor. The moderately differentiated endometrial carcinomas contained very low levels of the receptors. The poorly differentiated tumors virtually lacked the receptors. Metastatic lymph nodes from primary endometrial carcinomas with moderate differentiation had a very low receptor level. From these results, it is concluded that human endometrial carcinomas, particularly with histologically high differentiation, contain a considerable amount of androgen receptor and that the receptor concentrations appear to correlate with the histologic grade of tumor differentiation.

Adult↗
PubMed1984

Histochemical AMD electron microscopic studies of intercellular matrices of papilloma induced by painting DMBA on the skin of mice.

The localization and distribution of glycosaminoglycans (GAG) in papilloma tissue which was introduced by painting DMBA on the back skin of ICR mice were observed by light and electron microscopy. GAG consisting mainly of hyaluronic acid could be detected histochemically on the cell surface and extracellular matrices of the basal layer of the papilloma, but it could not be observed in the non-neoplastic epidermis. After incubation of tissue segments in a medium containing 35SO4, an autoradiograph was made, and 35S-radioactivity was observed in the interface between the papilloma epidermis and dermis. Ultrastructurally, the cell surface of keratinocytes in the basal layer of the papilloma was stained intensely with ruthenium red. A cell line was obtained from the papilloma, and GAG could be demonstrated on the cell surface and in the intercellular matrix of the cultivated keratinocytes by treatment with hyaluronidase. The significance of GAG in the proliferating squamous cells was discussed.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1983

X-ray structure analysis of thin filaments of a molluscan smooth muscle in the living relaxed state.

In the small-angle x-ray diffraction pattern of the living relaxed anterior byssus retractor muscle of Mytilus edulis, the thin filaments showed the following features. The 59.8-A reflection was much stronger and a little farther from the meridian than the 51.9-A reflection, although they are both contributions of the first-order Bessel function and are comparable with each other in the height from the equator. The 381-A reflection, given by the second-order Bessel function, was weaker than the 59.8-A reflection by more than the difference between the peak values of the first- and second-order Bessel functions, and was not so distant radially from the latter as estimated from the amount of peak shift brought about by the alteration of the Bessel order. A model of the thin filament was made on the basis of inverse Fourier transformation of the scattering amplitude, and the above features were explained by the characteristic shape of actin shown in this model. The actin subunits are elongated along the genetic left-hand helix with a pitch of 59.8 A, and are bonded together along the genetic helix in the inner part of the filament.

Animals↗
PubMed1983

Tumor stem cell assay for detecting metastases of human lung cancer.

We applied a tumor stem cell assay using an enriched double-layered soft agar system for the detection of metastatic sites of lung cancer. Lung cancer colonies grew from 7 of 10 effusions cytologically positive for tumor cells and 7 of 10 bone marrow aspirates cytologically and histologically positive for tumor cells. Twenty-six of 29 bone marrow aspirates cytologically and histologically negative for tumor cells showed no colony growth. However, the remaining three bone marrow aspirates, which were obtained from patients with small cell lung cancer, formed colonies in soft agar. These results indicate that the tumor stem cell assay is useful for detecting metastatic sites of lung cancer.

Bone Marrow↗
PubMed1983

Combination chemotherapy for small cell carcinoma of the lung: evaluation of four-drug combination of cyclophosphamide, vincristine, methotrexate, and procarbazine.

Forty-one patients with small cell carcinoma of the lung were treated with a four-drug combination of cyclophosphamide, vincristine, methotrexate, and procarbazine. The response rate was 68% (28 responded among 41 patients), with 10 complete responses (24%) and 18 partial responses (44%). The median survival time from the initiation of chemotherapy was 11 months for patients with limited disease and 8 months for those with extensive disease. Patients who achieved complete response survived significantly longer than those who did not; the median survival time for complete responders was 14.5 months, compared to 8.5 months for partial responders and 6 months for non-responders. Myelosuppressive toxicity remained within acceptable limits, with 5% incidence of leukocytopenia (less than 1,000/microliter) and 7% incidence of thrombocytopenia (less than 50,000/microliter) following the first course of the regimen.

Adult↗
PubMed1982

Pretreatment serum albumin concentration and lactic dehydrogenase activity as prognostic factors in patients with small cell lung cancer.

Pretreatment laboratory parameters were analyzed as prognostic factors in patients with small cell lung cancer. Serum lactic dehydrogenase activity, serum albumin concentration, PPD skin reaction, and peripheral lymphocyte count were of prognostic importance. When these factors were evaluated by multivariate analysis together with performance status and disease extent, lactic dehydrogenase and albumin were the most influential factors related to survival.

Carcinoma, Small Cell↗