PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Mast-Cell Sarcoma”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

Endothelium-associated IgG in the post-capillary venules of the lymphatic tissues in mice bearing experimental neoplasia.

Post-capillary venules (PVC) of the lymph nodes and Peyer's patches were studied in frozen sections stained with an indirect immunoperoxidase technique to demonstrate their endothelium-associated IgG in DBA/2 mice bearing mastocytoma. The previously established three types of IgG-distribution (luminal, intraendothelial and basement membrane site), each confined to one of the three PCV grades (graded on the basis of the endothelial cell height), were found in these tumor-bearing mice, too. This finding shows that the tool applied in T-lymphocyte deprivation, be it a tumor or anti-theta-globulin, does not influence the behavior of this IgG-distribution profile. This fact lends further support to the thesis that the endothelium-associated IgG could be involved in the regulation of the T-cell passage through the wall of the post-capillary venules.

Animals↗

Combined melanocytoma-mastocytoma in a case of nodular mastocytosis.

A patient with long-standing nodular mastocytosis developed a slate-blue lesion on the scalp which produced symptoms of histamine release on mechanical and thermal stimulation. Light and electron microscopic examination of the lesion showed zones of mast cells and zones of melanized cells. A transition zone showing cells with dual (melanosomal and mast) granulation, as well as granules representing intergrades between classical mast granules and melanosomes, was present. Features of this lesion add to the accumulated evidence that there is a histogenetic relationship between mast cells and melanocytes.

Adult↗

Lysosomotropic agents. 1. Synthesis and cytotoxic action of lysosomotropic detergents.

Amines whose pK values lie between about 5 and 9 are lysosomotropic because lysosomes are acidic intracellular compartments. If such amines bear long hydrophobic chains, they become detergents upon protonation inside the lysosomes, rupturing the lysosomal membrane and killing the cell. Six types of lysosomotropic amines have been prepared that all behave in the expected manner. They are cytotoxic to all lysosome-bearing cells but not red blood cells, which lack lysosomes. Their mode of action, the effect of alkyl chain length on activity, and the fact that their cytotoxic action appears only above a threshhold intracellular concentration support the belief that they behave as lysosomotropic detergents. Among the potential applications is cancer chemotherapy.

Amines↗

Podophyllotoxin analogs. 1. Synthesis and biological evaluation of certain trans-2-aryl-trans-6-hydroxymethyl-3-cyclohexenecarboxylic acid gamma-lactones as antimitotic agents.

A series of cis and trans bicyclic lactones was prepared as congeners of podophyllotoxin (1) and evaluated as antimitotic agents both in cell cultures grown in vitro and in an in vitro protein binding assay. All compounds displayed insignificant activity-a result which may reflect insufficient structural similarity to podophyllotoxin or which may be interpreted as in agreement with previous observations of the stereochemical requirements for antimitotic activity defined for 1.

Animals↗

Responses of an experimental solid tumour to irradiation: A comparison of modes of fractionation.

Several radiotherapeutic schedules compatible with continued structural-functional integrity of the gastrointestinal (GI) mucosa were compared utilizing the P815X2 murine mastocytoma grown as a solid subcutaneous tumour. Both the tumour and underlying normal tissues were irradiated during the treatments. The tumour exhibited a Do that increased from 210 rad to 397 rad as the tumour aged and in all instances demonstrated minimal shoulders in survival curves. In spite of a relative radioresistance of cells within the solid tumour, quite effective control of localized disease could be accomplished with radiotherapy schemes compatible with GI tolerance limits. Schedules evaluated utilizing this model included acute exposures to 1122 rad, daily exposure to 187 rad, 5 days/week exposures to 281 rad, twice weekly exposures (561 rad on Mondays and 374 rad on Thursdays) and a high dose, two fractions per day, schedule. Tumours were followed for changes in growth patterns during these schedules. Efficacy of tumour control was determined and schedules were compared on this basis. Aggressive radiotherapy approaching the tolerance limits of any of the fractionation schemes proved most effective.

Animals↗

Cytolytic effects of the complement cleavage product, C3a.

Purified C3a, a cleavage product of the third component of complement,was incubated with various cell types of human and mouse origin. All the tumour cell types tested were lysed by low concentrations of C3a, whereas normal human lymphocytes were relatively resistant. No lysis was produced by C3 or C3b. The possible role of C3a in immunity against tumours is discussed.

Animals↗

Appearance of cytolytic antibodies in sheep lymph following immunisation with tumour cells. Identification of antibody subclasses.

Sheep were immunised with mouse P815 tumour cell suspensions and at intervals afterwards lymph was collected draining from the stimulated lymph nodes. The lymph samples were fractionated by column chromatography into IgM, IgG1 and IgG2 antibody fractions; these were then assayed for cytolytic functions on 51Cr labelled target P815 cells. Complement dependent antibodies were assayed using sheep complement; activity was first detected in the IgM fraction 3-4 days after immunisation and in the IgG1 fraction at 5-6 days. No CDA activity was found in fractions of the IgG2 antibody subclass at any time. Leucocyte dependent antibodies were detected only in the IgG fraction, and they appeared simultaneously in both IgG1 and IgG2 subclasses 5-6 days after immunisation.

Animals↗