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Biomedical subjects

D Dahl

Publications and source records attributed to D Dahl.

At least 199 records · Page 11Linked to original sources
PubMed1980

Immunohistochemical localization of glial fibrillary acidic protein in human glial neoplasms.

The presence and distribution of glial fibrillary acidic protein in fixed, paraffin embedded tissue were studied in 85 human intracranial neoplasms, using the peroxidase-anti-peroxidase method. In some cases, indirect immunofluorescence of frozen sections was used as well. In normal tissue, only the cell processes and perikarya of fibrous astrocytes were stained. Immunostaining was also observed in the following glial neoplasms: astrocytomas (all varieties), astroblastoma, subependymal giant cell astrocytoma, subependymoma, glioblastoma multiforme and ependymoma. The astrocytic elements of mixed gliomas and of medulloblastomas undergoing glial differentiation were likewise strongly stained. In contrast, oligodendrogliomas, meningiomas, pituitary adenomas, sarcomas, lymphomas and metastatic carcinomas were negative. Either a perikaryal or a diffuse fibrillary staining pattern was observed. Combination of the two patterns occasionally occurred. The perikaryal staining was prominent in gemistocytic astrocytomas and in astroblastomas. A distinct negative correlation existed between the degree of anaplasia and the intensity of immunostaining.

Astrocytes↗
PubMed1980

Immunohistochemical characterization of neurofibrillary tangles induced by mitotic spindle inhibitors.

Neurofibrillary tangles were induced in the motor neurons of the rabbit spinal cord by the intrathecal injection of colchicine, vinblastine, and vincristine. The tangles stained intensely by immunofluorescence and by the peroxidase-anti-peroxidase procedure using neurofilament antisera raised against chicken brain antigen, as previously reported for aluminum-induced neurofibrillary tangles. No immunohistochemical reactivity could be demonstrated between the tangles and a 150,000 dalton bovine neurofilament antiserum, although the adjacent axons were intensely stained in cryostat sections of the spinal cord.

Animals↗
PubMed1980

Neurofilaments in the chick embryo during early development. I. Immunofluorescent study with antisera to neurofilament protein.

The time of appearance of neurofilament protein was determined by indirect immunofluorescence in the chick. Immunofluorescence first appeared in 3-day embryos as a peripheral layer on the ventral and lateral surfaces of the spinal cord and hindbrain. Concomitant with a marked thickening of this layer on the ventrolateral surface of the neural tube, neurofibrils were seen emerging from the cord and the myelencephalon. The immunofluorescent layer could be followed rostrally on the surface of the brain up to the mesencephalic flexure. In this location a large bundle of fibrils was observed emerging from the ventral surface of the mesencephalon. The posterior root ganglia and inner layer of the retina were intensely immunofluorescent on day 4. In the following days of development the spinal cord and ganglia assumed a mature configuration. The appearance of the anterior horns on the 6th day was remarkably segmental, the anterior horns being detected in alternate sections in a series of transverse serial section.

Animals↗
PubMed1979

GFA expression in aggregation cultures of rat C6 glioma.

Few C6 glioma cells synthesize the astroglia-specific GFA protein in monolayer culture. A uniform population of GFA-positive cells was obtained by aggregation C6 cells in suspension culture, as previously reported for C6 glioma maintained on sponge foam matrices. These results strongly suggest that cell-to-cell interactions promote GFA expression.

Animals↗
PubMed1979

Astroglial and axonal proteins in isolated brain filaments. I. Isolation of the glial fibrillary acidic protein and of an immunologically active cyanogen bromide peptide from brain filament preparations of bovine white matter.

The glial fibrillary acidic protein and an immunologically active cyanogen bromide peptide were purified by immunoaffinity chromatography from 8 M urea extracts of brain filament preparations isolated from bovine white matter according to Norton's procedure. The protein accounted for approximately 30% of the total protein in this preparation and for the largest fraction in the 50 000 molecular weight range. The fraction not absorbed to the immuno-Sepharose column reacted with neurofilament antisera by double immunodiffusion. On sodium dodecyl sulfate gel electrophoresis the main bands in the non-adsorbed fraction were at 74 000 daltons and above 100 000. Several bands were seen in the 50 000 molecular weight range. It is concluded that glio- and neurofilaments co-purify together in Norton's procedure and that neurofilaments are probably heterogeneous in polypeptide composition.

Animals↗
PubMed1979

Glial fibrillary acidic protein and intermediate filaments in human glioma cells.

Cultured human glioma cells were studied by double indirect immunofluorescence technique using antisera against intermediate filaments and glial fibrillary acidic protein. With both antisera cytoplasmic fibrillar fluorescence was seen. Perinuclear bundles of intermediate-sized filaments, induced by vinblastine treatment, were strongly stained with both antisera. The degree of codistribution of the two types of antigenic determinants varied considerably from cell to cell. The results suggest that two types of filament-related antigenic determinants can be present in the same cell, and also that glial fibrillary acidic protein-related filaments may possess functional similarities to the intermediate filaments found in other cells. Glial fibrillary acidic protein remains as a useful and specific antigenic marker for the study of glial cells in vitro.

Astrocytoma↗
PubMed1978

[Microphonic potentials in guinea pigs with liver damages].

In guinea pigs we produced certain histological liver damage. By 16 guic results of 16 guinea pigs without liver damage. The microphonic potentials of liverdamage animals was lower about 3.4 dB than potentials of healthy animals. Experimence in animals confirmed the hearingloss of inner ear and also pathological adaption by patients with chronic liver parenchym damage.

Animals↗
PubMed1978

Distribution of myosin and the glial fibrillary acidic protein (GFA protein) in rat spinal cord and in the human frontal cortex as revealed by immunofluorescence microscopy.

The glial fibrillary acidic (GFA) protein and myosin were localized in rat spinal cord and human frontal cortex using specific antibodies against GFA protein from human spinal cord and highly purified smooth myosin from chicken gizzard by means of an indirect immunofluorescence microscopical approach. A strong GFA protein and myosin immunoreactivity was found in astrocytes of the white and grey matter and in the external glial limitans membrane. The very fine branches of astrocytic processes stained with anti-GFA protein, but not with anti-myosin. Similar results were obtained with the human frontal cortex, where myosin antibodies failed to reveal the very fine branches of protoplasmic astrocytes. As a whole, staining with the GFA protein antiserum was more crisp than with the myosin antibody.

Animals↗