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Biomedical subjects

S I Wasserman

Publications and source records attributed to S I Wasserman.

At least 55 records · Page 3Linked to original sources
PubMed1986

Aminophylline exposure alters mouse bone marrow-derived mast cell adenosine responsiveness.

Aminophylline-treated mouse bone marrow-derived mast cells exhibit a hyperresponsiveness to adenosine addition (10(-6) to 10(-4) mol/L) at the time of secretagogue challenge coincident with an up regulation of adenosine receptor numbers. This effect on beta-hexosaminidase release is maximal at 100 mumol/L of aminophylline, evident after 5 days of aminophylline exposure, and reversed by 6 days after washing. Neither radiolabeled arachidonic acid nor leukotriene C4 release in the absence or presence of adenosine was altered by aminophylline treatment. Although cAMP levels were dynamically changed by adenosine or secretagogue, these changes were not different in the two cell populations; resting and challenged mast cell adenosine levels were similarly unaffected by aminophylline. The long-term action of aminophylline on mouse bone marrow-derived mast cells appears to be primarily on adenosine receptors and thereby on preformed mediators, and this action may have some importance in the pathophysiology and treatment of asthma.

Adenosine↗
PubMed1986

Generation and partial characterization of eosinophil chemotactic activity and neutrophil chemotactic activity during early and late-phase asthmatic response.

Asthma has been recognized to consist of hyperresponsive airways and cellular inflammation. Allergen bronchoprovocation (BPC) may define the early (EAR) and late-phase asthmatic response (LAR). The LAR has now been associated with increased nonspecific airway hyperresponsiveness and cellular inflammation consisting of neutrophils and eosinophils. We used BPC to demonstrate EAR and LAR in 12 subjects with seasonal allergic asthma. One normal subject and one subject with asthma who had been treated with allergy immunotherapy were challenged but did not respond. Plasma was sampled at frequent intervals during these aeroallergen challenges and assayed for eosinophil chemotactic activity (ECA) and neutrophil chemotactic activity (NCA). Of the 12 subjects with asthma who were challenged, nine had dual responses (both EAR and LAR), and three subjects demonstrated only an LAR. Those subjects who had dual airway responses had biphasic rises in both ECA (early = 267 +/- 28%; late = 286 +/- 28%) and NCA (early = 279 +/- 24%; late = 215 +/- 15%) in their plasma, whereas those subjects who demonstrated only an LAR had only a late rise in ECA (218 +/- 61%) and NCA (188 +/- 31%). The two individuals who did not respond to aeroallergen challenge demonstrated no change in their plasma chemotactic activity toward either eosinophils or neutrophils. Those individuals with the most severe LAR (greater than or equal to 1,000 mm2) had combined ECA plus NCA peak values of greater than 500%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Cromolyn inhibition of mediator release in mast cells derived from mouse bone marrow.

Mast cells derived from mouse bone marrow fail to demonstrate a disodium-cromoglycate-induced inhibition of mediator release when the cromolyn is added simultaneously with a secretagogue. To investigate the long-term effects of cromolyn exposure, cells from BALB/C femoral bone marrow stimulated with IL-3 were cultured in the presence of 1 to 100 microM cromolyn and demonstrated a similar viability and ability to proliferate as cells cultured in medium alone. Those cultured in cromolyn exhibited a significantly decreased A23187- or antigen-induced release of beta-hexosaminidase (4.3 +/- 0.7% versus 9.2 +/- 1.0%, p less than 0.01) compared with control cells. The adenosine-induced potentiation of mediator release was diminished to a comparable degree after cromolyn exposure in culture. This inhibition was dose-dependent between 1 and 100 microM cromolyn, evident by 5 days, reversible in 6 more days, and applied to immunoreactive leukotriene C4 generation as well. Bone marrow mast cells respond to chronic cromolyn exposure with a global inhibition of mediator release, but the basis for this response is unknown.

Adenosine↗
PubMed1985

The mast cell and theophylline in asthma.

Mast cells are central to the development of bronchial inflammation and thus to bronchial hyperreactivity, the cardinal feature of asthma. Inflammation is due to the concerted action of mast cell-dependent vasoactive/spasmogenic mediators, chemotactic factors, and enzymes. Adenosine, a newly synthesized mast cell mediator (from adenosine triphosphate), is one of the important inflammatory mediators capable of causing bronchospasm and, by interacting with mast cell membrane receptors, of augmenting mediator release induced by antigen. These inflammatory and pro-asthmatic actions of adenosine can be inhibited by concentrations of theophylline achievable in humans that are insufficient to alter cyclic adenosine monophosphate metabolism. Thus, a new therapeutic consideration in the use of xanthine drugs is their ability to inhibit adenosine binding to cell surface receptors and thereby inhibit the effects of this purine nucleoside.

Adenosine Triphosphate↗
PubMed1985

Association of platelet-activating factor with primary acquired cold urticaria.

We investigated the possibility that the inflammatory reaction in primary acquired cold urticaria might be associated with the release of platelet-activating factor. Six patients with the disease and five normal controls were subjected to cold-water challenges during which blood samples were obtained for measurement of the release of possible mediators: i.e., histamine, neutrophilic chemotactic activity, and platelet-activating factor-like lipid (PAF-LL). Four of the patients had pronounced experimentally induced cold urticaria with angioedema and release of mediators. Levels of the three mediators were not elevated in five normal controls or in two patients in whom cold challenges induced only mild urticaria and angioedema. The effective suppression of cold-induced urticaria in three patients treated with doxepin correlated with inhibition of PAF-LL release but not inhibition of histamine or neutrophilic chemotactic activity release. These data suggest a positive correlation between PAF-LL release and cold urticaria, although the exact relation between PAF-LL and cutaneous lesions of primary acquired cold urticaria has not yet been established.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1985

[3H]Adenosine binding to rat mast cells--pharmacologic and functional characterization.

Rat serosal mast cell adenosine receptors were characterized by [3H]adenosine binding to cell membrane particulates, and functional changes in mast cell mediator release and cyclic AMP levels were assessed, utilizing various adenosine analogs. [3H]adenosine binding to sonicated mast cell membrane preparations at 0 degrees C in the presence of deoxycoformycin is linear with initial cell number, rapid and reversible. The cells display 16,400 +/- 1600 high affinity [3H]adenosine binding sites/cell, equivalent to 118 fmol bound/mg protein, with an equilibrium dissociation constant of 27.97 +/- 3.0 nM. Competition studies reveal that adenosine greater than 2-chloroadenosine greater than NECA greater than L-PIA greater than D-PIA in competing for [3H]adenosine binding sites and that aminophylline and cromolyn sodium also bind to the putative receptor. Adenosine and its analogs, NECA, and L-PIA, appear to activate adenylate cyclase in resting mast cells by raising cyclic AMP, suggesting an Ra cell surface adenosine receptor subtype; these same analogs potentiate mast cell B-hexosaminidase release stimulated by specific antigen. The identification of rat mast cell [3H]adenosine binding sites whose stimulation augments resting cell cyclic AMP levels and antigen-induced mediator release suggests that these receptors may be important in the biochemical mechanisms of allergic diseases. The ability to assess the number and affinity of mast cell adenosine receptors will enable one to monitor receptor alterations during pharmacologic manipulation and in disease states.

Adenosine↗
PubMed1985

Future pharmacologic agents and maneuvers in asthma therapy.

Future therapeutic avenues in the treatment of asthma include the development of drugs to prevent mediator generation or release, to prevent receptor recognition of mediators, and to block end-organ responses to receptor occupancy; maneuvers to prevent or reverse IgE production; and therapies directed at preventing secondary inflammatory leukocyte activation. These new therapies should be used only after currently available drugs, education, immunotherapy, and supportive care are maximally employed, as these latter maneuvers are in the vast majority of patients efficacious, well tolerated, and safe.

Asthma↗
PubMed1985

Mast cell mediators in the blood of patients with asthma.

Mast cell activation occurs in allergic asthma and may play a role in a variety of nonallergic asthmatic states. The defined mast cell constituent histamine has been identified in blood of antigen-sensitive challenged asthma patients, while other mediators, whose cell of origin is not fully defined, accompany this amine in blood (Table 1). Due to technical difficulty in accurate assessment, the rapid metabolism of various constituents, and the need for biologic rather than chemical assay of some mediators, it is not yet possible to assess blood constituents for the unequivocal attribution of asthma to activation of a particular cell type. Likewise, the usefulness of blood studies in the prediction of the course of asthma or as serial measurements to define the severity of asthma remains limited. However, it is only with analysis of the appropriate biologic fluids, blood and/or bronchoalveolar lavage materials, that it will be possible to define which potential mediators are, in fact, present and active in asthma. Until such analysis is completed, it is not possible to assign a function in this disease to the numerous potent inflammatory mediators known to be active in in vitro or in vivo models of asthma.

Adenosine↗
PubMed1984

Increased biosynthesis of platelet-activating factor in activated human eosinophils.

1-Alkyl-2-lyso-sn-glycero-3-phosphocholine:acetyl-CoA acetyltransferase catalyzes the conversion of biologically inactive lysophospholipid to bioactive platelet-activating factor (1-alkyl-2-acetyl-sn-glycero-3-phosphocholine, PAF) by an acetylation reaction. The activity of this enzyme in eosinophils isolated from patients with eosinophilia is stimulated (up to 4-fold) in a dose-, time-, and Ca2+/Mg2+-dependent manner after exposure to the eosinophil chemotactic factor of anaphylaxis (ECF-A), C5a, formyl-methionylleucylphenylalanine (fMLP), or ionophore A23187. The three naturally occurring chemotactic factors (ECF-A, C5a, and fMLP) cause a rapid and transient increase of enzyme activity, with a maximum at 1 or 3 min, whereas ionophore A23187 maintains an elevated level for up to 15 min. The activity of 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine acetylhydrolase, an enzyme that catalyzes the breakdown of PAF to lyso-PAF, is not affected by C5a, fMLP, or ionophore A23187. The presence of PAF in eosinophils was established by demonstrating the lipid nature of the compound, the RF value being identical with that of synthetic 1-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine on thin layer chromatograms, and by its ability to induce serotonin release from rabbit platelets. Furthermore, ECF-A, C5a, fMLP, and ionophore A23187 all induce the secretion of PAF from eosinophils. These findings suggest that the generation and release of PAF could be a consequence of eosinophil chemotactic activation and may thus function in inflammatory and allergic reactions in which eosinophils participate.

Acetyltransferases↗
PubMed1984

Anaphylactic reaction to cytarabine: in vitro evidence that the response is immunoglobulin E mediated.

A 48-year-old female developed significant bronchospasm on two occasions after being treated with cytarabine (Ara-C) by the intraperitoneal route. In this report we present the first in vitro evidence that such a reaction to cytarabine can be associated with the release of histamine and therefore might be immunoglobulin E (IgE) mediated. In addition, this report emphasizes the fact that, while uncommon, severe allergic reactions to this useful chemotherapeutic agent do occur and must be considered in the differential diagnosis of anaphylaxis and related symptoms in patients receiving this drug.

Anaphylaxis↗
PubMed1984

Release of platelet factor 4 into the blood after cold challenge of patients with cold urticaria.

Five individuals with idiopathic cold urticaria but not normal volunteers released platelet factor 4 (PF4) detected by radioimmunoassay into the circulation after cold challenge. In three patients, a biphasic rise in PF4 was noted with increases at 1 and 10 to 20 min after immersion, whereas in two others only the later rise was detected. Peak levels of PF4 were detected in all five patients 20 min after cold immersion, whereas peak levels of other mediators such as histamine and eosinophil and neutrophil chemotactic activity occurred earlier at 10, 3 to 10, and 5 to 10 min, respectively. The identification of PF4 in the circulation of patients with cold urticaria after cold challenge provides further evidence for the activation of platelets in mast cell-dependent disorders and suggests new potential mechanisms for the expression of cold urticaria.

Adolescent↗
PubMed1984

Adenosine release from stimulated mast cells.

Adenosine release has been documented in lung tissue exposed to hypoxic conditions or antigen challenge. Exogenous adenosine potentiates mediator release from stimulated rat serosal and mouse bone marrow-derived mast cells. To investigate the production and release of adenosine from stimulated mast cells, rat serosal mast cells were purified on metrizamide gradients, sensitized with anti-dinitrophenol IgE for 30 min at 37 degrees C, and challenged in the presence of 1 microM deoxycoformycin with either dinitrophenol-conjugated bovine serum albumin antigen, the calcium ionophore A23187, or compound 48/80. Reactions were terminated by centrifugation, and the supernatants and pellets were assayed for adenosine and ATP content, respectively, by high performance liquid chromatography. The adenosine concentration of the supernatants increased from 0.036 +/- 0.003 nmol per 10(6) cells to 0.049, 0.056, and 0.129 nmol per 10(6) cells 60 sec after challenge with antigen, 48/80, or A23187, respectively. After ionophore stimulation, increased extracellular adenosine was evident by 15 sec, peaked by 60 sec, and remained constant for at least 5 min. A significant decline in stimulated ATP levels was observed within 30 sec, suggesting that the enhanced adenosine concentrations may result from the breakdown of ATP. Cultured mouse bone marrow-derived mast cells under similar conditions also displayed augmented extracellular adenosine levels with A23187 challenge. This endogenous source of adenosine may act locally through a positive feedback mechanism to potentiate immediate hypersensitivity reactions.

Adenosine↗
PubMed1984

Neutrophil chemotactic activity generation by alveolar macrophages after bleomycin injury.

Saline lavage was performed on rat lungs after the intratracheal injection of saline or bleomycin. An increase (p less than 0.025) in total cells recovered, an increase (p less than 0.001) in neutrophils, and an increase (p less than 0.001) in albumin concentration were noted in lavage fluid recovered from rats subsequent to bleomycin injury. At 5, 10, 15, and 20 days after injury, macrophages recovered from bleomycin-treated rats generated increased (p less than 0.05) amounts of neutrophil chemotactic activity in vitro compared with macrophages recovered from saline-treated rats. The chemotactic activity was attributable to a factor or factors of low molecular weight and hydrophobic in nature, characteristics similar to previously described alveolar macrophage-derived neutrophil chemotactic factors. The generation of neutrophil chemotactic activity was suppressed (p less than 0.025) by hydrocortisone and 5,8,11,14-eicosatetraynoic acid (ETYA), suggesting that the neutrophil chemotactic activity generation is dependent upon the lipoxygenase pathway of arachidonic acid metabolism.

5,8,11,14-Eicosatetraynoic Acid↗
PubMed1984

The human lung mast cell.

Mast cells are present in human lung tissue, pulmonary epithelium, and free in the bronchial lumen. By virtue of their location and their possession of specific receptors for IgE and complement fragments, these cells are sentinel cells in host defense. The preformed granular mediators and newly generated lipid mediators liberated upon activation of mast cells by a variety of secretagogues supply potent vasoactive-spasmogenic mediators, chemotactic factors, active enzymes, and proteoglycans to the local environment. These factors acting together induce an immediate response manifest as edema, smooth muscle constriction, mucus production, and cough. Later these mediators and those provided from plasma and leukocytes generate a tissue infiltrate of inflammatory cells and more prolonged vasoactive-bronchospastic responses. Acute and prolonged responses may be homeostatic and provide for defense of the host, but if excessive in degree or duration may provide a chronic inflammatory substrate upon which such disorders as asthma and pulmonary fibrosis may ensue.

Arachidonic Acid↗
PubMed1984

Biochemical and functional characterization of proteoglycans isolated from basophils of patients with chronic myelogenous leukemia.

Human basophils were obtained from three donors with myelogenous leukemia. Proteoglycans were labeled by using [35S]sulfate as precursor and were extracted in 1 M NaCl with protease inhibitors to preserve their native structure. [35S]proteoglycans filtered on Sepharose 4B with an average m.w. similar to that of a rat heparin proteoglycan that has an estimated m.w. of 750,000. The [35S]glycosaminoglycan side chains filtered with an average m.w. slightly smaller than a 60,000-m.w. glycosaminoglycan marker. The [35S]glycosaminoglycans were resistant to heparinase and susceptible to degradation by chondroitin AC lyase and chondroitin ABC lyase. The intact [35S]glycosaminoglycans chromatographed on DEAE Sepharose as a single peak eluting just before an internal heparin marker. These findings indicate that the [35S]glycosaminoglycans were made up only of chondroitin sulfates. No heparin was identified. The chondroitin sulfate disaccharides that resulted from the action of chondroitin ABC lyase on the basophil glycosaminoglycans consisted of 92% delta Di-4S, 6% delta Di-6S, and 2% disulfated disaccharides. The [35S]chondroitin sulfate proteoglycans were susceptible to cleavage with proteases and could be shown to be released intact from basophils during degranulation initiated by the calcium ionophore A23187. The basophil proteoglycans and glycosaminoglycans were capable of binding histamine in water, but not in phosphate-buffered saline, and had no anticoagulant activity.

Basophils↗