Search results for "RATS"

Surface phenotype and functions of tumor-infiltrating dendritic cells: CD8 expression by a cell subpopulation.

1993

Although the function and significance of tumor-infiltrating dendritic cells (TIDC) in the immune response to tumor have never been clearly demonstrated, their location suggests that they play a critical role in the presentation of tumor antigen to specific T cells. We studied the morphological and functional characteristics of interstitial dendritic cells (DC) located inside tumors obtained by injection of cancer cells into syngeneic rats. Single and double immunostaining of tumor sections revealed a dense network of cells which expressed class II major histocompatibility complex (MHC II) molecules. Cell morphology and surface markers were characteristic of DC populations in other tissues.…

Protection of Flupirtine on β-Amyloid-Induced Apoptosis in Neuronal Cells In Vitro: Prevention of Amyloid-Induced Glutathione Depletion

2002

Effective drugs are not available to protect against beta-amyloid peptide (A beta)-induced neurotoxicity. Cortical neurons from rat embryos were treated with the toxic fragment A beta25-35 at 1 microM in the presence or absence of flupirtine, a triaminopyridine, successfully applied clinically as a nonopiate analgesic drug. Five days later 1 microM A beta25-35 caused reduction of cell viability to 31.1%. Preincubation of cells with flupirtine (1 or 5 microg/ml) resulted in a significant increase of the percentage of viable cells (74.6 and 65.4%, respectively). During incubation with A beta25-35 the neurons undergo apoptosis as determined by appearance of the characteristic stepladder-like D…

Biologic effects of ultrasound on liver cells of rat embryos.

1987

Experiments on the biologic effects of ultrasound (US) were carried out on rat embryos exposed for 120 s to a US beam showing features similar to those already employed for diagnostic purposes. Electron microscopic investigation of the liver parenchyma of rat embryos confirmed results obtained from adult guinea pigs with the same duration of exposure, i.e. diffuse vacuolization of cytoplasma and varying degrees of mitochondrial damage.

Ultrastructural localization of Ca2(+)-binding sites in the middle ear mucosa of the rat.

1990

Cations were precipitated with potassium-pyroantimonate in the middle ear mucosa of the rat and the distribution of the formed precipitates was studied by electron microscopy. The precipitate density in various cells of the different epithelia of the middle ear mucosa was determined on electron micrographs by counting the number of precipitates per unit area. Electron spectroscopic imaging was also performed to obtain information about the spatial distribution of the precipitates and their elemental composition.

Experimental emetine myopathy: enzyme histochemical, electron microscopic, and immunomorphological studies.

1993

Ipecac, containing emetine hydrochloride, is used by patients with anorexia nervosa to induce vomiting. Its chronic usage may result in a myopathy and a cardiomyopathy, the former marked by cytoplasmic bodies. We studied myopathological changes after daily injections of female Wistar rats with emetine hydrochloride intraperitoneally for periods of 4, 5, 9, and 10 weeks. the extensor digitorum longus muscle and the soleus muscle showed core-like lesions, streaming of the z-discs, nemaline bodies, cytoplasmic bodies, and spheroid cytoplasmic bodies. Immunomorphological studies revealed increased amounts of desmin. During a period of repair, i.e., 2, 4, and 6 weeks after termination of emetine…

Proliferating macrophages, dendritic cells, natural killer cells, T and B lymphocytes in the middle ear and Eustachian tube mucosa during experimenta…

2001

SummaryAlthough many studies focus on the increase of immunocompetent cells within the middle ear mucosa during acute otitis media it is poorly understood how this increase is mediated. The differentiation between two possible causes, i.e. immigration and local proliferation, would help to better understand the pathophysiology of this disease. Therefore, the number of proliferating macrophages, dendritic cells, natural killer cells and T and B lymphocytes was studied during acute otitis media in the rat middle ear mucosa (ME mucosa) and Eustachian tube mucosa (ET mucosa) by labelling proliferating leucocytes with the DNA precursor bromodeoxyuridine (BrdU). By removing the middle ear and Eus…

Influence of different histologic preparation methods on preservation of tissue antigens in the immunofluorescent antibody technique.

1975

The distribution of blood group antigens in rodent epithelia

1984

The pattern of distribution of antigens cross-reacting with antibodies to human blood group antigens A and B and two precursor molecules was examined by immunofluorescence in the epidermis, oral mucosa and forestomach of rats and mice. Staining for blood group antigen A was negative. In all epithelia examined, blood group antigen B was present at the surface of basal and parabasal cells, and the H antigen at the surface of spinous cells. N-acetyllactosamine was present on the cell membranes in the upper spinous and granular cell layers of epidermis and forestomach epithelium and was not expressed in the oral epithelia except for a limited area in the dorsal tongue epithelium. Thus, the expr…

Characteristic intraepidermal nerve fibre endings of the intervibrissal fur in the mystacial pad of the rat: morphological details revealed by intrav…

1999

Light microscopic observations employing intravital methylene blue staining and impregnation by the zinc iodide-osmium tetroxide technique are presented for intraepidermal nerve fibre endings of the intervibrissal fur in the mystacial pad of the rat snout. Both procedures revealed anatomical details of the intraepidermal nerve fibre plexus in epidermal hillocks often located very close to the mouths of hairs. These nerve fibres appeared to resemble those described in previous immunohistochemical studies as cluster or bush endings. The methylene blue preparations demonstrated the existence of an intensely stained enlargement at the site of the branching point of the nerve fibres which seemed…

A novel monoclonal antibody to a distinct subset of cutaneous dendritic cells.

1992

A monoclonal antibody was generated by immunizing rats with Langerhans cell (LC)–enriched epidermal cells obtained from BALB/c mouse earskin after epicutaneous application of the contact sensitizer 2,4-dinitrofluorobenzene (DNFB). The antibody 4F7 detects in normal mouse skin, few dermal cells showing the morphologic, phenotypic, and functional properties of accessory dendritic cells, but lacking Birbeck granules. The capacity to stimulate allogenic T cells in the mixed leucocyte reaction resembles that of freshly isolated LCs. After DNFB application, an increased number of 4F7+ dendritic cells are found in the dermis and, in addition, some labeled dendritic cells occur in the epidermis. So…