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Biomedical subjects

M E Feigenson

Publications and source records attributed to M E Feigenson.

9 recordsLinked to original sources
PubMed1985

3,4-Diphenyl-1H-pyrazole-1-propanamine antidepressants.

A small series of compounds is described in which a narrow SAR has identified N,N-dimethyl-3,4-diphenyl-1H-pyrazole-1-propanamine, 3, as a potential antidepressant with reduced side effects. The isomeric N,N-dimethyl-4,5-diphenyl-1H-pyrazole-1-propanamine was completely inactive in the primary antidepressant screens. Compounds were synthesized by Michael addition of acrylonitrile to diphenylpyrazole followed by reductive alkylation of the resultant diphenylpyrazolepropionitriles. Compound 3 was equipotent with imipramine in standard antidepressant assays in animals but showed no significant anticholinergic action and did not antagonize the antihypertensive effects of clonidine and guanethidine.

Animals↗
PubMed1983

Spasmolytic activity of cinnamedrine and papaverine in isolated rat uterine muscle.

The objective of this work was to thoroughly examine the smooth muscle relaxing properties of cinnamedrine, compared with papaverine, in vitro, using rat uterus. Cinnamedrine and papaverine both exhibited dose-related spasmolytic activity in the isolated spontaneously contracting rat uterus and in uterine tissue pretreated with oxytocin to augment spasms. The IC50's for cinnamedrine and papaverine were 36.2 and 7.7 microM respectively; the IC50's after oxytocin pretreatment were 25.7 microM for cinnamedrine and 10.0 microM for papaverine. Neither hormonal status of the rats, with respect to their estrus cycle, nor oxytocin pretreatment of the isolated tissues noticeably affected the activity of either cinnamedrine or papaverine.

Animals↗
PubMed1978

The polymorphonuclear leukocyte.

Polymorphonuclear leukocytes (PMNs) are one of the main sources of enzymes responsible for tissue damage in inflammatory processes. These enzymes are stored in two types of cytoplasmic granules. Azurophil granules contain lysosomal hydrolases, neutral serine proteinases, and bactericidal elements (myeloperoxidase and lysozyme). Specific granules contain collagenase, lysozyme and lactoferrin but lack lysosomal hydrolases. PMNs store all four classes of tissue proteinases, carboxyl, thiol and serine proteinases in the azurophil granules, and metallo proteinases in the specific granules. Three serine proteinases have been identified, elastase, cathepsin G and a third enzyme, which together account for a large proportion of the protein of the azurophil granules. In the course of phagocytic events, all these enzymes are released extracellularly. The neutral proteinases degrade proteoglycans and collagen. In vitro, they stimulate B-lymphocytes, which suggests that they may have immuno-potentiating activity when they are released at sites of chronic inflammation.

Animals↗
PubMed1978

Capping of ricin-binding sites does not influence phagocytosis in human polymorphonuclear leukocytes.

Human polymorphonuclear leukocytes (PMN'S) were incubated at 0 degrees C with ferritin-conjugated ricin and warmed to 37 degrees C to induce capping of the ricin-binding sites. The PMNs were then allowed to phagocytose yeast or Staphylococcus epidermidis for 15 min, and processed for electron microscopy. Phagocytic uptake, granule fusion, and the fate of lectin-bound membrane were quantified by morphometry. Ricin-capped PMNs phagocytosed as extensively as untreated PMNs. Particles were ingested almost exclusively with a lectin-free portion of the plasmalemma. Fusion of granules with phagocytic vacuoles was not affected by ricin-induced capping. This indicates that ricin-binding sites are not involved in particle recognition and uptake.

Binding Sites↗
PubMed1976

Capping of concanavalin A- or ricin-binding sites does not influence phagocytosis in polymorphonuclear leukocytes.

Rabbit polymorphonuclear leukocytes (PMNs) were capped with territin-conjugated concanavalin A or ricin, and then allowed to phagocytose yeast cells. Phagocytic activity and lectin distribution were determined by ultrastructural morphometry. Capped PMNs were found to phagocytose as efficiently as control PMNs, and always to ingest the particles with a lectin-free portion of their plasma membrane. This clearly indicates that concanavalin A- and ricin-binding sites of the PMN membrane are not involved in the recognition and phagocytosis of yeast particles.

Animals↗
PubMed1976

Ricin- and concanavalin A-binding sites on the surface of polymorphonuclear leukocytes have no receptor function in phagocytosis.

Human and rabbit polymorphonuclear leukocytes (PMN) were incubated at 0 degrees C with ferritin conjugates of ricin or concanavalin A,and subsequently brought to 37 degrees C in order to induce the formation of lectin caps. The PMN were then alllowed to phagocytose yeast cells or staphylococci for 15 min and were subsequently processed for electron microscopy. The micrographs were evaluated by morphometry. It was found that lectin-treated PMN phagocytose as efficiently as untreated cells. Capped cells always engulfed the particles with a lectin-free portion of their plasma membrane. This indicates that ricin- and concanavalin A-binding sites on the PMN surface are not involved in particle recognition and uptake. The virtual absence of lectin on the membrane of the phagocytic vacuoles suggests that capped PMN is functionally polarized and only able to phagocytose at the pole opposite the cap.

Animals↗