Biomedical subjects

H H Newball

Publications and source records attributed to H H Newball.

At least 19 recordsLinked to original sources

PubMed1995

Effects of endotoxin on expression of VLA integrins by human bronchoalveolar lavage macrophages.

Endotoxin (lipopolysaccharide, LPS) is known to induce inflammatory responses, such as monocyte/macrophage adherence, migration, and accumulation. Recruitment and accumulation of macrophages during infection and inflammation are regulated by integrin-mediated cell-extracellular matrix interactions. In the present report, we studied the effects of LPS on the expression of VLA-5 (alpha 5 beta 1), VLA-3 (alpha 3 beta 1), and VLA-2 (alpha 2 beta 1) integrins and fibronectin (FN) by human alveolar macrophages in an attempt to understand the mechanism by which LPS regulates macrophage adhesion to matrix proteins. Bronchoalveolar lavage macrophages were treated with varying concentrations of Escherichia coli LPS for different times and evaluated for expression of the integrins and FN by immunofluorescence, immunoelectron microscopy, autoradiography, and radioimmunoassay. Immunofluorescent and immunoelectron microscopic observations showed that VLA integrins were constitutively expressed on the cell surface and concentrated on the microvilli and pseudopodia of the macrophages. The effects of LPS on expression of the integrins were dose and time related. VLA-5 expression was increased after 30 min of stimulation by LPS, suggesting that LPS may induce rapid secretion of the integrin. However, incubations with LPS longer than 30 min decreased VLA-5 expression in a dose-dependent pattern. LPS also caused dose-related decreases in the expression of VLA-3 and VLA-2 integrins and increases of intracellular FN 24 h after stimulation. The results suggest that a prolonged exposure to LPS may impede VLA integrin-mediated migration and result in local accumulation of macrophages in the lung.

Autoradiography↗

PubMed1992

Uptake, distribution and fate of bacterial lipopolysaccharides in monocytes and macrophages: an ultrastructural and functional correlation.

Bacterial lipopolysaccharides (LPS), which are important components of the cell wall of gram-negative bacteria, induce a number of host responses both beneficial and harmful. The present review elucidates the uptake, distribution and functions of LPS in mononuclear phagocytes in an attempt to gain an insight into the mechanisms which control the pathogenesis of LPS mediated septic shock. The unique feature of LPS bilayer structure, the tagged LPS and antibodies to LPS provide means for studying binding, uptake, fate and subcellular distribution of LPS in tissues and cells. LPS bind to monocytes and macrophages by specific interaction via receptors such as scavenger receptors, CD14 and CD18 and by non-specific interactions, and enter the cells via receptor-mediated endocytosis, absorptive pinocytosis, phagocytosis, and diffusion. The ingested LPS are localized in pinocytic vesicles, phagocytic vacuoles, cytoplasm, mitochondria, rough endoplasmic reticulum, Golgi apparatus, and nucleus. The interactions of LPS with monocytes and macrophages trigger a broad spectrum of cellular responses, including production of important bioactive factors or mediators, such as IL-1, TNF, interferons, prostaglandins, and macrophage-derived growth factor, which are implicated in the pathogenesis of septic shock and wound healing. However, there is no conclusive evidence indicating that production of the mediators can only be induced through specific interactions.

Animals↗

PubMed1989

Release of elastase from purified human lung mast cells and basophils. Identification as a Hageman factor cleaving enzyme.

Elastase, a serine protease, is capable of inducing severe lung destruction in experimental animal models. We now report that this proteinase exists preformed in neutrophil-free sonicates of purified human lung mast cells (greater than 98% purity) and in circulating peripheral blood basophils (greater than 97% purity). The elastase levels in both cell types (41-174 ng/10(6) cells) represents approximately 3-20% of those found in human neutrophils; both cell types released their elastase following anti-IgE and ionophore A23187 challenge. The apparent molecular size of the mast cell enzyme on Sephadex G-100 gel filtration, as well as its inhibition profile, was identical to that of purified human neutrophil elastase. This mast cell elastase is identical to our previously reported mast cell-derived Hageman factor cleaving activity. Mast cell-, basophil-, and neutrophil-derived elastases cleave Hageman factor into fragments of 52,000 and 28,000 Da; cleavage by all three enzymes is inhibited by preincubation with polyclonal antibodies directed against human neutrophil elastase.

Autoradiography↗

PubMed1986

Organophosphate-induced histamine release from mast cells.

To examine the hypothesis that soman intoxication leads to degranulation of mast cells with the release of histamine, we studied the effects of soman on rat peritoneal mast cells (RPMC) in vitro and in vivo. In vitro studies were performed with RPMC harvested from Edgewood rats, and challenged with soman (10(-8)-3 X 10(-3) M) in Tyrode's buffer. The RPMC exhibited a dose-dependent release of histamine, with maximal release of 50% at 3 to 6 X 10(-4) M. The release process is an active, secretory, noncytotoxic event, which is calcium and temperature dependent, requires metabolic energy and is influenced by intracellular levels of cyclic AMP. We next studied the in vivo effects of disodium cromoglycate (DSCG, 10(-4) M) on soman and Compound 48/80-induced histamine release. In vivo studies were performed by the i.p. injection of 5 ml of Tyrode's buffer containing soman (O-1 LD50), or Compound 48/80 as a positive control, with or without DSCG. The fluid recovered after approximately 10 min in the peritoneal cavity was examined for percentage of histamine release. In vivo, Compound 48/80 induced 49 +/- 1% histamine release, with no inhibition by DSCG (Compound 48/80 plus DSCG induced 49 +/- 0.4% histamine release). On the other hand, soman (1 LD50) induced 17 +/- 5% extracellular histamine release, with complete inhibition by DSCG (soman plus DSCG induced 3 +/- 1% histamine release). The data indicate that soman induced a dose-dependent release of histamine from RPMC, and provide evidence that histamine is a potentially important mediator of the pathophysiological response to organophosphate intoxication.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1986

The IgE-dependent release of a Hageman factor cleaving factor from human lung.

Passively sensitized human lung fragments were shown to release a protease by an IgE-dependent mechanism which can cleave human Hageman factor (Coagulation Factor XII). This enzyme, lung Hageman factor cleaving factor, was partially purified by ion exchange chromatography and gel filtration and was shown to be a serine protease with an apparent molecular weight of 12,000-13,000. This protease appears to be unrelated to any known activator of Hageman factor by molecular weight and inhibition profile and was shown to be distinct from an IgE-dependent prekallikrein activator, as well as the kininogenase activity defined as basophil kallikrein of anaphylaxis. Although it appears marginally capable of activating Hageman factor, it rapidly cleaves and inactivates the activated form so that the net effect is a loss of activatable Hageman factor. The result suggests that diminished levels of Hageman factor that may be seen associated with IgE-dependent reactions can be due to digestion and depletion rather than activation, and other criteria for activation of the contact system must be employed.

Antigens↗

PubMed1985

Immunoglobulin E-mediated release of a kininogenase from purified human lung mast cells.

Certain manifestations of the allergic response, such as vasodilation and edema, may be attributed to the involvement of kinins, but, as yet, little data exist to show how these peptides could be produced during IgE-mediated events. We now report that purified human lung mast cells contain a kininogenase that is released in a dose-dependent fashion by anti-IgE. Release of kinin-generating activity parallels that of histamine and, like histamine release, kininogenase release is temperature-dependent. Kininogenase release also parallels increasing histamine release when mast cells of increasing size are stimulated with an optimal level of anti-IgE. Finally, when mast cells of greater than 99% purity were optimally challenged, kininogenase activity again paralleled histamine levels in the release supernatant and residual cell pellet. The mast cell kininogenase appears to be a preformed mediator in that it occurs in lysates of unstimulated mast cells of greater than 99% purity. Optimal generation of kinin from highly purified human low molecular weight kininogen occurred at pH 5.5 and in 8 preparations was 380 +/- 237 ng kinin/h/10(6) mast cells (means +/- SD). Thus, human lung mast cells contain a kininogenase that is released during, and may participate in, IgE-mediated inflammatory disorders in humans.

Antibodies, Anti-Idiotypic↗

PubMed1985

Immunoglobulin E-mediated degranulation of isolated human lung mast cells.

We used an ultrastructural approach to analyze morphologic changes in isolated human lung mast cells during IgE-induced degranulation. We found that after stimulation with anti-IgE, mast cell cytoplasmic granules became swollen, their complex matrix patterns became altered, and their membranes fused to produce chains of granules which enlarged to become tortuous cytoplasmic degranulation channels. These channels eventually opened to the surface of the cell at multiple points in the circumference of the cell. Loss of altered granule matrix occurred in the absence of extrusion of formed granules or granular structures to the exterior of the cell. As channels opened to the exterior a remarkable activation of cell surface occurred. This was initially characterized by elongation and increasing complexity of surface processes. At later times, many free membranes were found adjacent to small mast cells which had diminished granule numbers and smooth surfaces. All of these changes were seen in morphologically undamaged cells and constitute a readily recognizable sequence of IgE-induced release events in isolated human lung mast cells.

Antibodies, Anti-Idiotypic↗

PubMed1984

Differences in the behavior of cytoplasmic granules and lipid bodies during human lung mast cell degranulation.

We used a morphometric and autoradiographic approach to analyze changes in specific cytoplasmic granules and cytoplasmic lipid bodies associated with human lung mast cell degranulation. Mast cells were dissociated from lung tissue by enzymatic digestion and were then enriched to purities of up to 99% by countercurrent centrifugation elutriation and recovery from columns containing specific antigen bound to Sepharose 6 MB. Degranulation was induced by goat anti-IgE. At various intervals after stimulation, parallel aliquots of cells were recovered for determination of histamine release or were fixed for transmission electron microscopy. We found that lipid bodies, electron-dense structures that lack unit membranes, were present in both control and stimulated mast cells. Autoradiographic analysis showed that lipid bodies represented the major repository of 3H-label derived from [3H]arachidonic acid taken up from the external milieu. By contrast, the specific cytoplasmic granules contained no detectable 3H-label. In addition, lipid bodies occurred in intimate association with degranulation channels during mast cell activation, but the total volume of lipid bodies did not change during the 20 min after stimulation with anti-IgE. This result stands in striking contrast to the behavior of specific cytoplasmic granules, the great majority of which (77% according to aggregate volume) exhibited ultrastructural alterations during the first 20 min of mast cell activation. These observations establish that mast cell cytoplasmic granules and cytoplasmic lipid bodies are distinct organelles that differ in ultrastructure, biochemistry, and behavior during mast cell activation.

Antibodies, Anti-Idiotypic↗

PubMed1983

Comparative studies of human basophils and mast cells.

Atopic disease in humans results primarily from the activity of tissue mast cells and circulating basophils. These two very similar cell types have recently been purified to near homogeneity and studies have begun to identify the biochemical mechanisms of mediator release, to explore the effects of pharmacologic manipulation of the response, and to determine unambiguously which mediators are derived from mast cells and basophils. This report will review studies examining various parameters of histamine release, the role of cyclic AMP in histamine release, and the production of arachidonic acid metabolites and their pharmacologic modulation.

Animals↗

PubMed1983

Novel effects of PGF2 alpha on airway function in asthmatic subjects.

The effects of inhaled prostaglandin F2 alpha (PGF2 alpha) have been examined in eight subjects with asthma. Incremental PGF2 alpha aerosol concentrations, ranging from 1 to 5,000 micrograms/ml, were administered at 15-min intervals. Plethysmographic specific airway conductance (sGaw), forced expiratory volume at 1 s (FEV1), and maximum expiratory flow at 50% vital capacity breathing air (Vmax50% air) and 80% He-20% O2 (Vmax50% He-O2) were measured after each dose and compared with saline control values. We observed unexpected triphasic dose-response characteristics, i.e., an initial decline in physiological variables at low concentrations (1-100 micrograms/ml), followed by improvement at intermediate concentrations (100-1,000 micrograms/ml) and a subsequent steep decline at high concentrations (1,000-5,000 micrograms/ml). Improvement in FEV1 and Vmax50% air between 100 and 1,000 micrograms/ml was associated with sGaw increases above control levels in six subjects and a significant fall in density-dependent index (Vmax50% He-O2/Vmax50% air) when compared with values before challenge and at low concentrations. Inhaled atropine (5 mg) improved prechallenge lung function but had no effect on PGF2 alpha dose-response characteristics. Intermediate PGF2 alpha concentrations given as a single dose consistently induced greater FEV1 reductions than the same concentration during graded dose challenges. Our findings are consistent with the demonstration of in vivo airway tachyphylaxis and indicate that airway effects of PGF2 alpha are far more complex than previously reported. Moreover, these novel effects suggest that, in addition to its well-known bronchoconstrictor effects, PGF2 alpha directly or indirectly causes airway relaxation, predominantly in large airways.

Adolescent↗

PubMed1983

BL-5255 II: effects on release and smooth muscle activity of mediators of immediate hypersensitivity reactions.

BL-5255 inhibited release of preformed mediators from passively sensitized mast cells in the rat peritoneal cavity, chopped monkey lung or human lung tissue. The compound failed to block rat cutaneous reactions elicited by histamine or serotonin. It exhibited weak to no ability, depending on the mediator employed, to block contraction of isolated guinea pig ileum or tracheal tissue. At concentrations of 1 microM or greater, BL-5255 itself was contractile to the ileum but not to the quiescent or submaximally contracted trachea. The compound relaxed spontaneously contracting rabbit jejunum muscle but at doses not likely to be achieved in vivo. Phosphodiesterase activities in extracts of rat and human lung were inhibited at concentrations greater than those required to inhibit mediator release.

Anaphylaxis↗

PubMed1983

Anaphylactic release of a prekallikrein activator from human lung in vitro.

We have demonstrated the in vitro IgE-mediated release of a prekallikrein activator from human lung. The lung prekallikrein activator was partially purified by sequential chromatography on sulfopropyl-Sephadex, DEAE-Sephacel, and Sepharose 6B. Purified human prekallikrein was converted to its active form (kallikrein) by the lung protease. The generated kallikrein was shown to be biologically active; that is, it generates bradykinin from purified human high-molecular weight kininogen and also cleaves benzoyl-propyl-phenyl-arginyl-p-nitroanilide, a known synthetic substrate of kallikrein. The lung prekallikrein activator differs from the known physiologic activators of prekallikrein (the activated forms of Hageman factor) with respect to: (a) size (it has a mol wt of approximately 175,000); (b) synthetic substrate specificity (D-propyl/phenyl/arginyl-p-nitroanilide is a substrate for the activated forms of Hageman factor, but not the lung protease); (c) antigenic specificity (an anti-Hageman factor immunoadsorbent column did not remove significant amounts of the lung protease, while it removed most of the activity of activated Hageman factor fragments); and (d) inhibition profile (the lung proteases was not inhibited by corn trypsin inhibitor). This prekallikrein activator provides a physiologic mechanism by which prekallikrein can be directly activated during IgE-mediated reactions of the lung. While the role of this lung prekallikrein activator in immediate hypersensitivity reactions and in other inflammatory processes is not clear, it does represent a first and important interface between IgE-mediated reactions and the Hageman factor-dependent pathways of the inflammatory response.

Anaphylaxis↗

PubMed1983

Purified human basophils and mast cells: current concepts of mediator release.

Mediators released from human basophils and mast cells in response to immunologic and other stimuli are felt to be important in the pathophysiology of several nasal and pulmonary disease processes. Recently, we have developed techniques to purify these cells, thus allowing precise ultrastructural, biochemical and pharmacological studies of mediator release. Previous literature has emphasized the similarities of the two cell types including their metachromatic staining and IgE-mediated release of mediators. However, we now appreciate that several differences exist between the two cell types. At the ultrastructural level, basophil release is characterized by individual granules emptying to the cell exterior, while mast cell granules fuse intracellularly and release their contents through cytoplasmic channels. Functionally, basophils are 10- to 30-fold more sensitive than mast cells to anti-IgE, but the kinetics of release are less rapid. Basophil, but not mast cell, release is (I) inhibited by histamine H2 agonists and glucocorticoids; (II) enhanced by PgD2 and (III) modulated by arachidonic acid lipoxygenase metabolites. Significant quantities of slow-reacting substance of anaphylaxis, PgD2 and platelet-activating factor are generated by mast cells. Basophils produce little or none of these mediators. Studies with these purified, relevant human cell types should provide important insights into the cellular basis of hypersensitivity states and their control.

Basophils↗

PubMed1982

Cyclooxygenase metabolites in human lung anaphylaxis: airway vs. parenchyma.

We studied the generation of arachidonic acid cyclooxygenase metabolites (AACMs) during in vitro anaphylaxis of passively sensitized human lung parenchymal and airway fragments. Prostaglandins E, F2 alpha, D2, 6-keto-prostaglandin F1 alpha, and thromboxane B2 (PGE, PGF2 alpha, PGD2, 6-keto-PGF1 alpha, TXB2, respectively) were assayed by radioimmunoassay. Results with airway tissue were compared with subpleural parenchymal fragments from the same lungs similarly challenged. Spontaneous generation of prostacyclin (PGI2), as measured by its stable metabolite 6-keto-PGF1 alpha, exceeded by two- to threefold other spontaneous AACM release in both bronchial and parenchymal fragments. In airway antigen produced variable AACM responses, but in general the rank order was 6-keto-PGF1 alpha greater than PGE congruent to PGF2 alpha greater than PGD2 greater than TXB2. The rank for antigen-induced AACM release from parenchyma was 6-keto-PGF1 alpha congruent to PGD2 much greater than PGF2 alpha greater than TXB2 congruent to PGE. In airway, as in parenchyma, very little AACM production during anaphylaxis can be attributed to smooth muscle contraction per se. Histamine released from bronchi (0.67 +/- 0.30 micrograms/g lung) was significantly less than from parenchyma (3.7 +/- 0.70 micrograms/g) despite comparable histamine content. At comparable levels of histamine release, the parenchyma produced greater quantities than bronchi of all AACMs except PGE. The comparatively limited bronchial capacity to generate PGF2 alpha, PGD2, TXB2, and histamine (airway constrictors) along with predominant generation of PGI2 and PGE (airway relaxants) may help preserve airway patency.

Anaphylaxis↗

PubMed1982

Dispersed human lung mast cells. Pharmacologic aspects and comparison with human lung tissue fragments.

The present investigation was designed to study the histamine release and pharmacologic characteristics of dispersed human lung mast cells, particularly in comparison with parenchymal tissue fragments. Dispersed human lung mast cells were prepared by enzymatic treatment (yield, 0.5 to 2 x 10(6) mast cells/g tissue). Purity was 1 to 8% (mean, 3.6% +/- 0.7%), and histamine content varied from 2 to 6 pg/cell (mean, 3.6 +/- 0.5 pg/cell). Release, studied using anti-IgE as the stimulus, was relatively rapid, being essentially complete within 15 min when high concentrations of anti-IgE (greater than or equal to 0.3 microgram/ml) were used and was not enhanced by phosphatidyl serine. The concentration of drug required to inhibit histamine release by 50% in dispersed cells for a series of pharmacologic agents, including the beta-adrenergic agent fenoterol, the prostaglandin E2, and the phosphodiesterase inhibitor isobutylmethylxanthine, were 0.1 to 1 microM, 50 microM, and 0.5 mM, respectively; similar results were obtained in simultaneous experiments performed using tissue fragments. Adenosine enhanced release (19 +/- 3.4%) at low concentrations (10 microM) and inhibited release (61 +/- 5.1%) at high concentrations (1mM). The H2 agonist, dimaprit (at 10(-5) to 10(-7) M) and prostaglandin D2 (at 10(-4) to 10(-6) M) had no effect on histamine release, whereas deuterium oxide potentiated histamine release. This study serves to quantitate the pharmacologic effects of several agents on anti-IgE-mediated histamine release from dispersed human lung mast cells and has further suggested that the dispersed cell system is similar to the standard chopped lung system in dose-response relationships, kinetics, and pharmacologic modulation. It also indicates that the enzymatic treatment of the cells does not affect the release characteristics or functional capacity of several different receptors, and that this preparation, therefore, appears suitable as an in vitro human model of mediator release that can be used for the evaluation of pharmacologic agents and for further mast cell purification.

1-Methyl-3-isobutylxanthine↗

PubMed1982

Generation of leukotrienes by purified human lung mast cells.

Although mediator release from mast cells and basophils plays a central role in the pathogenesis of human allergic disease, biochemical studies have been restricted to rat peritoneal mast cells and basophilic leukemia cells because they could be easily purified. We have used two new techniques of cell separation to purify human lung mast cells to 98% homogeneity. Lung cell suspensions were obtained by dispersion of chopped lung tissue with proteolytic enzymes. Mast cells were then purified from the suspensions by countercurrent centrifugal elutriation and affinity chromatography. The purified mast cells released both histamine and slow-reacting substance of anaphylaxis (SRS-A) (leukotriene C and D) during stimulation with goat anti-human IgE antibody. Moreover, these preparations were able to generate significant quantities of SRS-A (32 +/- 7 x 10(-17) LTD mole-equivalents/mast cell) at all stages of purification, indicating that a secondary cell is not necessary for the antigen-induced release of SRS.

Animals↗

PubMed1982

The effect of cold exposure on diffusing capacity in patients with Raynaud's phenomenon.

Pulmonary hypertension is common in progressive systemic sclerosis (PSS), and the presence of "pulmonary Raynaud's phenomenon" has been postulated from a variety of evidence. In this study, the effect of cold-induced Raynaud's phenomenon on carbon monoxide diffusing capacity (Dco), an indicator of pulmonary capillary blood volume, was determined in patients with Raynaud's phenomenon with an without PSS. Cold exposure caused an increase in Dco in patients without PSS, but no change in patients with PSS. We concluded that patients with systemic sclerosis have an altered pulmonary vascular response to cold exposure compared with other Raynaud's patients, which may be due to either structural or functional abnormalities of the pulmonary vascular bed.

Adolescent↗

PubMed1982

Human lung mast cells: purification and characterization.

Detailed studies of the biochemistry and pharmacology of mast cell-mediated inflammatory disorders have been hampered by the inability to purify human mast cells. We now report techniques to purify human lung mast cells to apparent homogeneity. The major purification steps are: 1) dispersion of lung fragments into a single-cell suspension with enzyme combinations (pronase-chymopapain, collagenase-elastase); 2) partial purification by countercurrent centrifugation elutriation (CCE); and 3) affinity column chromatography. Enzymatic dispersion yielded suspensions with congruent to 10(6) mast cells per gram of lung parenchyma in purities of 1.2 to 9.7%. Dispersed mast cells responded comparably to those in parent lung fragments to challenge with anti-human IgG and pharmacologic agonists. Elutriation of lung cell suspensions yielded mast cell-enriched fractions with purities up to 70%. High purity mast cell fractions were combined, passively sensitized with purified human penicillin (BPO)-specific IgE, and purified by a BPO-affinity column chromatography procedure. Post elutriation mast cell purities of 29 +/- 3.5% were increased to 84 +/- 3% (range 65 to 98%) by the affinity column. Short-term (24 hr) culture of column-purified mast cells allowed adherence of non-mast cell contaminants to tissue culture plates, further increasing purity (up to 100%). Purified mast cells were intact and functional as assessed by dye exclusion, survival in short-term culture, IgE-mediated histamine release, and modulation of release by the pharmacologic agonists adenosine, IBMX, prostaglandin E2, and fenoterol.

Cell Separation↗