Search PubMed⌕ Search

Biomedical subjects

M Toga

Publications and source records attributed to M Toga.

At least 91 records · Page 5Linked to original sources
PubMed1980

Macrophagic activity in intracerebral germinoma: ultrastructural study of a case.

This report presents the ultrastructural study of a germinoma of the third ventricle occurring in a 13 year old boy. The electron microscopic data showed similarities linking this tumor to gonadal and mediastinal germinomas and emphasized the exceptional glycogenic storage in tumor and stroma cells. Another morphological analogy was the intense macrophagic activity that led to tumor cell phagocytosis. The authors discuss the meaning of such an immune response, which is usually not observed in cerebral tumors.

Adolescent↗
PubMed1980

Prostaglandin in human breast cancer: Evidence suggesting that an elevated prostaglandin production is a marker of high metastatic potential for neoplastic cells.

Prostaglandin (PG) production by human breast cancers was investigated in 91 lesions selected so that the distribution of histologic type was similar to that of the general population of mammary carcinomas. With regard to the shape characteristics of the tumors, PG production was higher in lesions classified T1 and T2 than in lesions classified T3 and T4 (T-classification is based on extent of tumor as graded by the International Union Against Cancer), higher in tumors exhibiting a high cellularity than in lesions with a low tumor cell density and higher in tumors in which the cells were still adherent to each other. A high PG production was associated with the presence of neoplastic cells in tumor lymphatic and blood vessels and in axillary lymph nodes. PG production by node metastases was always higher than that by the primary tumor sites. The analysis of the stroma reaction and the presence of edema and necrosis suggest that an active PG synthesis occurred in lesions in which the tumor cell-surrounding stroma presented characteristics of low resistance to invasive growth of cancer cells. With regard to histologic differentiation and histoprognostic grade of lesions, PG production was elevated in carcinomas that retained a minute part of the acinoductal differentiation and in tumors with a moderate or high degree of cancer. A lesion containing a steroid receptor (SR) tended to produce less PG than did an SR-negative tumor. PG production increased slightly according to ages and times of menopause of the patients. PG production occurred early in the natural course of breast cancer and was elevated in tumors at a time when active tumor invasion proceeded. By contrast, PG production decreased later in the course of tumor development. These results indicated that elevated PG production can be used as a marker of high metastatic potential for neoplastic cells in breast cancer.

Adult↗
PubMed1979

Multiple steroid receptors in human breast cancer. III. Relationships between steroid receptors and the state of differentiation and the activity of carcinomas throughout the pathologic features.

Histopathologic features (tumor cell density, histological type, and histoprognostic grade) were analyzed in 314 breast cancers investigated for estrogen (E) and progestin (P) receptors (R). The presence of PR is associated with the presence of ER. A relationship was found between the acinoductal differentiation of the lesions and the presence of SR: the more differentiated the carcinoma, the higher the frequency of ER. HPG III carcinomas have the lowest frequency of positive ER and HPG I tumors the opposite: the likelihood of the presence of SRs is inversely correlated with HPG. No statistically significant relationship existed between tumor cell density (TCD) and the presence of ER or ER content. Similar findings were observed for the stromal reaction. The results are discussed with respect to the biological significance of SR and histopathologic features: SR presence could be correlated with (1) a differentiated state of the tumors and (2) a slow rate of cellular replication.

Aged↗
PubMed1979

Tumorigenic clones of hamster brain cells transformed in vitro by polyoma virus. Ultrastructural and immunohistochemical study.

The morphological characteristics of three clones of hamster brain cells transformed in vitro by polyoma virus and of the tumors obtained after subcutaneous grafting of these cells in syngenic animals are reported. These clones appeared to be glial in nature by light and electron microscopy. The initial tumors induced by the three clones presented astrocytic features both by electron microscopy and immunohistochemistry. Analysis of the subsequent in vivo passages showed a decrease in cell differentiation, which was accompanied by a decrease in the latency period; after 2 years of serial transplantation, the tumors seemed poorly differentiated gliomas. A control cell line of hamster cerebellar cells evolved similarly.

Animals↗
PubMed1979

Normal and benzo(a)pyrene-transformed fetal mouse brain cells. II. Ultrastructural study.

An ultrastructural study was performed on normal and Benzo(a)-pyrene(B(a)P)-transformed fetal mouse brain cells. Early subcultures of a strain initiated from whole brain presented three cell types in vitro: astroglial, poorly differentiated glial, and spongioblastic types. After B(a)P-treatment, there was an exclusive transformation and the growth of neuroglia sometimes without gliofibrillary maturation, but with the presence of glial fibrillary acidic protein (GFAP) in the cytoplasm. Early subcultures of another strain initiated from cortex only presented poorly differentiated neuroglial cells. After transformation, cell maturation as evidenced by gliofibrillogenesis and GFAP production by these cells was observed. In both cases, the potentiality of glial differentiation after in vitro malignant transformation by a chemical carcinogen seemed preserved.

Animals↗
PubMed1979

[Immunocytochemical similarities between basophilic and chromophobe pituitary adenomas. Light and electron microscopic study of 13 cases (author's transl)].

ACTH, beta MSH, beta LPH, beta endorpSin, leucine and methionine enkephalin activities were tested in four Cushing pituitary basophilic adenomas and nine "chromophobe" adenomas with immunoperoxidase methods. The antisera gave various positive reactions in both of these groups. ACTH, alpha MSH and enkephalins were predominant. The reason why these hormones are clinically silent in "chromophobe" or, even, basophilic adenomas is still to be elucidated.

Adenoma, Basophil↗
PubMed1979

Prostaglandins in human breast cancer. Identification of a cytosolic prostaglandin-9-keto-reductase activity.

Endogenous sources of prostaglandin production in human breast tumors were investigated by radioimmunoassay analysis of PGE2 and PGF2a productions and 3H-PGE2 conversion. PG synthetase located within the microsomal fraction mainly produced PGE2, while little PGF2a synthesis occured. In cytosol preparations. PGE2 is converted into PGF2a. In 15 tumor specimens, no relationship was observed between PGE2 production and the metabolic activity which varied widely from sample to sample. These findings demonstrate the presence of PG-9-keto-reductase in the cytosol from human breast tumors. A way of PGE2 inactivation by this enzyme is suggested since no less polar PGE2 metabolites were detected. It is concluded that PGE2 production by the microsomes will reflect the PG synthetase activity of a given human mammary carcinoma while metabolic conversion of PGE2 within the cytosol reflects the metabolic activity of the same sample. Both activities were otherwise apparently unlinked.

Breast Neoplasms↗
PubMed1978

Ultrastructural studies of extraocular muscles in ocular motility disorders. II. Morphological analysis of 38 biopsies.

Thirty eight extraocular muscle biopsies obtained from thirty patients (1 normal and 29 affected with various kinds of ocular motility disorders such as strabismus, Duane's syndrome, paralysis), were studied by electron microscopy. Except for the control biopsy considered as normal, they showed: atrophy, disorganization of myofilaments, double Z-disks, rods, curving arrays of myofibrils, concentrically disposed electron-dense sarcotubules, clusters of mitochondria with numerous modifications of their cristae, and subsarcolemmal inclusions, such as dense bodies, laminated bodies, lipofuscin granules and lipid droplets. In addition, subsarcolemmal granulo-fibrillar aggregates, characterized by periodic granulated foci spaced at about 120 nm intervals, were seen in all the biopsies, even in that of the control case. The authors stress the pecularity of the granulo-fibrillar aggregates which, up to now, have never been described in skeletal muscles and the function of which in the extraocular muscles fibers is impossible to define. They point out the difficulty in determining if the motility disturbances may be related to the various changes observed in extraocular muscles of squinting eyes.

Adolescent↗
PubMed1978

[Ultrastructural study of meningiothelial meningioma with 'hyaline inclusions' (author's transl)].

One case of meningiothelial meningioma with "hyaline inclusions" (colloid-bodies or pseudopsammomas) as noted by Cushing and Eisenhardt (1938) and by Kepes (1961-1975) is reported by light and electron microscopy. Two types of these structures, either homogeneous or polymorphic, surrounded by microvilli are described and regarded as signs of secretory differentiation of tumor cells. In addition to Kepes' description, the authors show, at high magnification, the polymorphic material including homogeneous component, lamellar structures, microvesicles and dense bodies. The endocellular overproduction of the various types of "hyaline inclusions" and the nature of their material are discussed.

Female↗
PubMed1978

Neoplastic transformation of hamster brain cells in vitro by polyoma virus.

The transformation of cultivated hamster brain cells by polyoma virus is reported. The transformed cell line contained polyoma virus-specific nuclear, surface and transplantation antigens. Subcutaneous and intracranial inoculations revealed high tumorigenicity of the cells. Brain-specific S 100 protein was found in these tumors with immuno-peroxidase staining, suggesting that they were of a nervous nature. Both in vivo and in vitro, the cells had glial features as studied by phase contrast, light and electron microscopy. Type-H virus-like particles were found in the tumor cells and might have played a role in the viral transformation.

Animals↗