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Biomedical subjects

S I Wasserman

Publications and source records attributed to S I Wasserman.

At least 91 records · Page 5Linked to original sources

Physical urticaria/angioedema: an experimental model of mast cell activation in humans.

Urticaria and angioedema may occur in skin and mucus membranes when mast cells are activated by various physical stimuli, including trauma, pressure, vibration, light, cold, heat, and (in rare cases) water. Experimental challenge of patients with cold-induced and cholinergic urticaria/angioedema in particular provides an in vivo model of mast cell activation in humans. This model synthesizes observations of the evolution of clinical manifestations, histologic analysis of tissue alterations, measurement of mediators released into the circulation, and assessment of leukocyte motility. The model in turn allows a characterization of mediators that exist preformed in mast cell granules or that are generated through interactions with other cell types. Release of these mediators produces a variety of biologic effects, including elaboration of certain enzymes and alterations in venular permeability, smooth muscle contraction, leukocyte motility, and the release of substances from other cell types.

Angioedema↗

Alterations of the electrophoretic mobility distribution of rat mast cells after immunologic activation.

Changes in the electrophoretic mobility distributions of rat serosal mast cells after immunologic activation have been measured using the laser Doppler technique of electrophoretic light scattering. Rat serosal mast cells of 98% purity isolated by isopycnic and velocity gradient sedimentation had a highly negative electrophoretic mobility which was unaffected by incubation with normal rabbit serum or, at 4 degrees C or in the absence of Ca+2, with rabbit anti-rat E(ab')2 antiserum. Immunologic activation of the cells with this antiserum in the presence of Ca+2 at 37 degrees C resulted in a dose- and time-dependent increase in the electrophoretic mobility. Thus at a 1:25 dilution of anti-F(ab')2 the mean and mode electrophoretic mobilities of the mast cell population increased 25 and 21%, respectively. The width of the electrophoretic mobility distribution also increased with activation, indicating a heterogeneous response of the mast cells in the population. The increase in electrophoretic mobility after immunologic activation is not diminished by treatment of the cells with 1 M NaCl to solubilize adsorbed mast cell granule or heparin.

Animals↗

Identification of sulfated mucopolysaccharides including heparin in the lesional skin of a patient with mastocytosis.

Comparison of the [35S]mucopolysaccharides extracted after in vitro incubation of skin biopsy specimens from nonlesional and lesional sites of a patient with mastocytosis showed that lesional sites incorporated sulfate into heparin. After in vitro incorporation of the [35S]sulfate, the tissues were extracted sequentially by a 3-step procedure which utilized high salt concentrations, enzymatic digestion and base hydrolysis to liberate essentially all the counts. The extracted [35S]mucopolysaccharides were separated from free [35S]sulfate, histamine, protein, and hyaluronic acid by ion-exchange chromatography utilizing Dowex 1. The [35S]mucopolysaccharide extracts of the nonlesional skin were completely degraded by treatment with chondroitinase ABC, as they age predominantly dermatan sulfate with small amounts of chondroitin sulfates. The absolute quantity of sulfated mucopolysaccharides after Dowex 1 chromatography in micrograms of uronic acid per mg wet weight of starting tissue was higher in the lesional than the nonlesional specimen, while the specific incorporation of [35S]sulfate per microgram of uronic acid was the same. Approximately one-half of the [35S]mucopolysaccharides obtained in the 3 sequential extracts of lesional tissue was resistant to degradation by chondroitinase ABC as determined by gel filtration before and after enzyme treatment, indicating the presence of sulfated mucopolysaccharides in addition to chondroitin and dermatan sulfates. Heparinase treatment of the chondroitinase ABC-resistant [35S]mucopolysaccharides followed by gel filtration revealed an equal distribution of label between heparin and heparinase-resistant material presumed to be heparan sulfate. Heparin was also directly demonstrated in extracts of lesional mastocytosis skin by chemical and functional criteria.

Glycosaminoglycans↗

Evaluation of role played by mediators of immediate hypersensitivity in exercise-induced asthma.

To determine whether mediators of immediate hypersensitivity played a role in the pathogenesis of exercise-induced asthma, we measured the concentration of histamine and neutrophil-chemotactic activity present in systemic arterial blood during thermal challenges in five asymptomatic asthmatics. Because exercise-induced asthma has been shown to be a result of respiratory heat loss and because respiratory heat loss during isocapnic hyperventilation has been shown to give identical responses, we chose the latter provocational method in order to minimize increases in cardiac output that might interfere with the interpretation of mediator concentrations in arterial blood. Multiple aspects of pulmonary mechanics were also recorded before and after provocation. The results of these studies were then compared with the effects observed when the same subjects inhaled aerosols of specific antigens on the same day. Each challenge produced identical alterations in lung function, and neither was associated with consistent changes in arterial histamine. However, antigen provocation evoked a sustained and prolonged release of neutrophil chemotactic activity in each subject, whereas isocapnic hyperventilation with cold air was without effect. These data strongly suggest that mast-cell derived mediators are not involved in the development or maintenance of the bronchial obstruction that follows exercise in asthmatics.

Adult↗

The lung mast cell: its physiology and potential relevance to defense of the lung.

The mast cell, located at mucosal surfaces and surrounding venules, is uniquely positioned to respond rapidly to insults to the host by mediating the development of a wide-ranging inflammatory response. Activaton of the mast cell releases preformed granule-associated chemical mediators and generates de novo biologically active materials. The properties of the mast cell mediators permit development of both acute and prolonged inflammatory responses. the immediate response is characterized by edema and the delayed response by leukocyte infiltration and vascular damage. the mast cell mediators responsible for these inflammatory events are characterized functionally. The vasoactive/smooth muscle reactive mediators include preformed histamine and serotonin and newly-generated platelet activating factor, slow reacting substance of anaphylaxis and prostaglandins. Chemotactic mediators include eosinophil-selective ECF-A and ECF-oligopeptides, neutrophil-selective NCF, and lipid chemotactic mediators with broad specificity. These factors induce directed migration and localization of leukocytes. The mast cell releases the structural proteoglycan, heparin, which is anticoagulant and inhibits complement. Released mast cell enzymes include chymotryptic and tryptic proteases, arylsulfatase, beta-glucuronidase, and hexosaminidase. The proteolytic enzymes may activate inflammatory pathways while the others degrade ground substance. The capacity of the mast cell to enhance vascular permeability, to cause the influx of regulatory or inflammatory leukocytes, and to provide a variety of active enzymes permits regulation of inflammatory events at the site of tissue injury.

Animals↗

Oral disodium cromoglycate in the treatment of systemic mastocytosis.

A double-blind crossover study of the efficacy of disodium cromoglycate given by mouth to control the cutaneous, gastrointestinal and central-nervous-system manifestations of systemic mastocytosis was carried out in five patients for periods of eight to 32 months. In 15 of 18 trials, disodium cromoglycate produced marked amelioration of the clinical manifestations of pruritus, whealing, flushing, diarrhea, abdominal pain and disorders of cognitive function. By contrast, in all 19 trials with placebo, there was no improvement in these symptoms and signs. Histaminuria and peripheral-blood eosinophilia were unrelated to disease activity and were unaffected by drug therapy. Although it is poorly absorbed after administration by mouth, disodium cromoglycate is of clinical benefit to patients with systemic mastocytosis.

Administration, Oral↗

Substances which modulate leukocyte migration are present in CSF during meningitis.

We studied the effects on in vitro leukocyte migration of cerebrospinal fluid from 14 patients with and 7 patients without meningitis. Meningitic CSF, but not control CSF, contained activity that was chemotactic for peripheral blood leukocytes. In an unusual case of staphylococcal meningitis associated with a blunted CSF pleocytosis and a poor clinical response to antibiotics, an inhibitor of leukocyte chemotaxis was identified in the CSF. This inhibitor may have diminished local leukocyte accumulation in vivo and thereby adversely affected host defense mechanisms and clinical outcome. No inhibitors were found in other CSF samples tested. Soluble mediators present in CSF may modulate the local accumulation of leukocytes and therefore affect host defenses in meningitis.

Chemotaxis, Leukocyte↗

Differential effects of a partially purified preparation of slow-reacting substance of anaphylaxis on guinea pig tracheal spirals and parenchymal strips.

The contractile effects of partially purified slow-reacting substance of anaphylaxis (SRS-A) and histamine were compared on isolated guinea pig tracheal spirals and parenchymal strips. Histamine was equally active on both isolated tissues in a concentration-related fashion. SRS-A (0.1--10.0 U/ml) produced a concentration-related effect on parenchymal strips, whereas the tracheal spiral was 100 times less sensitive to this mediator. The contractile activity of SRS-A on parenchymal strips was diminished by incubation with limpet arylsulfatase and antagonized by FPL 55712, a known SRS-A antagonist. SRS-A, further purified by high pressure liquid chromatography, also demonstrated this preferential activity on guinea pig parenchymal strips. These data are consistent with the hypothesis, based on previous in vivo observations, that SRS-A is a selective peripheral airway constrictor.

Airway Obstruction↗

Isolation and characterization of heparin from human lung.

Heparin as measured by azure A metachromasia and anticoagulant activity has been extracted with 1 M NaCl from (35)S-labeled human lung fragments or dispersed human lung cells enriched for mast cells. The (35)S-labeled metachromatic material in the 3 M NaCl eluate from Dowex-1 chromatography of the extract from lung fragments exhibited an average mol wt of 20,000 by Sepharose 4B gel filtration. The (35)S-labeled metachromatic material with the charge characteristics of commercial porcine heparin on DEAE cellulose chromatography was entirely heparin by the criteria of resistance to degradation by chondroitin ABC lyase and complete degradation by purified heparinase. Antithrombin affinity chromatography of purified heparin with an anticoagulant activity of 137 U/mg, revealed that the one-third that was bound and eluted had a 273 U/mg sp act, whereas the unbound activity was 31 U/mg. Thus, the previously observed heterogeneity of commercial porcine heparin for binding to human antithrombin was also observed with human heparin. The mast cell-enriched human lung cell preparations yielded [(35)S]mucopolysaccharides with an average mol wt of 60,000 by Sepharose 4B gel filtration. Approximately 30% of this fraction was degraded by chondroitin ABC lyase, and the residual 70% was degraded by purified heparinase. When the chondroitin ABC lyase-resistant fraction was subjected to alkali degradation the average mol wt was reduced to 20,000. The calculated human lung mast cell heparin content of 2.4-7.8 mug/10(6) cells gave a ratio to histamine on a weight basis similar to that of intact lung fragments, thereby implying that heparin in the lung fragments was largely restricted to the mast cells.

Anticoagulants↗

Inhibition of neutrophil chemotaxis in association with experimental angioedema in patients with cold urticaria: a model of chemotactic deactivation in vivo.

Deactivation is a phenomenon in which leucocytes exposed in vitro to a chemotactic factor in the absence of a concentration gradient are rendered relatively unresponsive to stimulation by a subsequent chemotactic gradient. In patients with idiopathic cold-induced urticaria, the elicitation of a local experimental angioedematous lesion causes the release of two chemotactic principles previously shown to deactivate leucocytes in vitro, high molecular weight neutrophil chemotactic factor (HMW-NCF) and eosinophil chemotactic factor of anaphylaxis (ECF-A), into the venous circulation draining the challenged extremity. However, biopsy specimens of lesional skin sites obtained for up to 24 hr show no infiltration of cells. For this reason, the in vitro chemotactic responsiveness of neutrophils to the chemotactic factor HMW-NCF and C5 fragments were assessed in three patients at various times after experimental challenge. Leucocytes from venous effluent draining an experimentally-induced angioedematous lesion were markedly impaired in their chemotactic responsiveness to both chemotactic factors 5 min after challenge, while cells taken from an unchallenged extremity at the same time responded normally. Cells from both arms were equally impaired in their responsiveness 1 hr later, thereby demonstrating that the chemotactic defect becomes systemic. The acquired defect was dissipated 4 hr after challenge. These data suggest that deactivation may occur in vivo and may alter host responsiveness in states where chemotactic factors are released into the circulation.

Angioedema↗

Release of arylsulfatase A but not B from rat mast cells by noncytolytic secretory stimuli.

The net percentage of release of arylsulfatase activity from purified rat mast cells induced by rabbit anti-rat F(ab')2 was consistently only about 1/3 that of histamine. Isoelectric focusing of the released and residual arylsulfatase activities demonstrated specific release of the A type without B and a net percentage of immunologic release of arylsulfatase A equivalent to that of histamine. When the net percentage of histamine and arylsulfatase A release were nearly maximal (88 and 76%) in response to the calcium ionophore A23187, specific release of arylsulfatase B did not occur. Thus, arylsulfatase A and not B was associated with the secretory granule released from the rat mast cell by reversed anaphylaxis or the calcium ionophore. In contrast, subcellular fractionation of water-lysed mast cells yielded arylsulfatase B with the heparin- and chymase-containing granule fraction and arylsulfatase A in the aqueous fraction comprised of cell sap and granule water eluate. It may be that arylsulfatase B resides in a minor second granule, whereas arylsulfatase A is loosely associated with the predominant secretory granule of the rat mast cell.

Acetylglucosaminidase↗