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Bronchial tissue kallikrein is the major kininogenase activity in the airways of asthmatic subjects. The relationship of IgE-mediated events to its release and/or activation is unknown, however, and is the subject of this report. Seven subjects with mild atopic asthma underwent endobronchial challenge with relevant aeroallergen. Baseline pre-allergen lavage and sequential post-challenge lavages were collected over an approximate 10-minute time course. Individual aliquots were analyzed separately and compared with saline control lavages performed in a separate lobe. In five of the seven subjects, an increase in tissue kallikrein activity, measured by cleavage of the synthetic substrate Val-Leu-Arg-pNA, was identified in the post-challenge lavages. The antigenic identity of the enzymatic activity was confirmed as a tissue kallikrein in each case by immunoblotting. Tissue kallikrein activity was highly correlated with the appearance of immunoreactive histamine and kinin (p = 0.0001). High molecular weight kininogen influx and cleavage was detected in the post-challenge samples by immunoblotting and paralleled the detection of kinin in BAL fluid. Two of the subjects, despite clinical profiles similar to those of the five positive responders, failed to react to endobronchial challenge. Saline control lavages contained detectable kallikrein, kinin, and histamine in two subjects; in each case, however, this was significantly less than in the post-allergen samples. The results demonstrate a close association between immediate type hypersensitivity events in the lower airway and the appearance of active kallikrein, kininogen substrate, and the liberation of kinin.

Neuroblastoma cells accumulate ascorbic acid and iron. It was hypothesized that these features could be exploited for sensitizing neuroblastoma cells for therapy in combination with reactive oxygen intermediates. In the present study the effects of 6-hydroxydopamine (6-OHDA) and H2O2 on metabolic parameters critical for cell survival were investigated in cells with low and high ferritin content in the presence and absence of ascorbate. Human neuroblastoma SK-N-SH cells were pretreated with 100 microM FeSO4 and 10 microM desferrioxamine, respectively, for 24 h yielding cells with different ferritin contents. The effects of 6-OHDA and H2O2 (25 microM-250 microM) in the absence and presence of 1 mM ascorbic acid on DNA strand break formation, activation of poly(ADP-ribose) polymerase, and finally decrease in NAD+ and ATP concentration were investigated. All these parameters were influenced by 6-OHDA and H2O2 in a concentration-dependent manner in a similar way. The effects were most pronounced in ferritin-rich cells and in the presence of ascorbic acid. Using isolated CCC PM2 DNA, 6-OHDA and ascorbic acid caused strand breaks that were prevented in the presence of mannitol or desferrithiocine. H2O2-mediated strand breaks were observed only in the presence of ascorbic acid. Based on these data and data published by others a model explaining the deleterious effects of ascorbic acid on neuroblastoma cells is presented. It is suggested that continuous application of a high dosage of ascorbic acid might be a useful approach in neuroblastoma therapy.

We have cloned a cDNA for the platelet activating factor (PAF) receptor by screening an HL-60 granulocyte cDNA library with degenerate oligonucleotide probes based on conserved sequences of rhodopsin-type receptors. The 342-amino acid receptor contains 7 putative transmembrane domains, but lacks sites for N-linked glycosylation at the N-terminus. Stably transfected fibroblasts expressing the cloned cDNA responded to sub-nanomolar PAF stimulation with calcium mobilization, which could be inhibited by the PAF antagonist L-659,989. The PAF receptor message was detected as a single species of approximately 4 kb in human placenta, lung, and differentiated HL-60 granulocytes. Expression of the cloned cDNA in undifferentiated HL-60 cells devoid of endogenous PAF receptor resulted in specific and saturable binding of the PAF antagonist WEB 2086 with a dissociation constant of 30.7 nM.

We investigated the requirement for N-formyl peptide receptor-mediated transmembrane signalling in transfected mouse fibroblasts that express the receptor. Stably transfected cells displayed specific binding for N-formyl-Met-Leu-[3H]Phe with a dissociation constant of 3 nM. The cells responded to ligand stimulation with mobilization of calcium from intracellular stores. Calcium mobilization was ligand dose-dependent (EC50 = 3 nM fMet-Leu-Phe) and could be inhibited by pertussis toxin treatment. These results provide the first demonstration that expression of the single-chain N-formyl peptide receptor in mouse fibroblasts is sufficient for mediating ligand-induced early transmembrane signalling events, which do not appear to require other neutrophil-specific cellular components.

The temperature dependence of dipalmitoylphosphatidylcholine (DPPC)/phosphatidylglycerol (PG) multilayers, reconstituted with various synthetic peptides for modeling human lung surfactant, was monitored by vibrational Raman spectroscopy. The synthetic peptides consisted, respectively, of residues 59-81 of the human surfactant protein SP-B and 21 amino acid residue peptides containing repeating units of arginine separated by either four or eight leucines (RL4 or RL8). Each peptide demonstrated the ability to reduce significantly the surface tension of analogues of the phospholipid mixture used in the Raman studies. Raman spectroscopic integrated band intensities and relative peak height intensity ratios, two spectral parameters used to determine bilayer disorder, provided sensitive probes for characterizing multilayer perturbations in the reconstituted liposomes. Temperature profiles derived from the various Raman intensity parameters for the 3100-2800-cm-1 carbon-hydrogen (C-H) stretching mode region, a spectral interval representative of acyl chain vibrations, reflected lipid reorganizations due to the bilayer interactions of these peptides. For the three reconstituted multilamellar surfactant systems, the gel-to-liquid-crystalline phase-transition temperatures Tm, defined by acyl chain C-H stretching mode order/disorder parameters, increased from 35 degrees C in the peptide free system to 37-38 degrees C, indicating increased lipid headgroup constraints for the model liposomes. Although the values of Tm were similar for the three recombinant lipid/peptide assemblies, individual phase-transition cooperativities varied significantly between systems and between spectroscopically derived order/disorder parameters.

Synthetic pulmonary surfactants consisting of mixtures of phospholipids with synthetic peptides based on the amino acid sequence of human surfactant apoprotein SP-B were prepared. These surfactants were analyzed for their ability to lower surface tension on a pulsating bubble surfactometer and for their capacity to improve lung compliance and increase alveolar expansion in a fetal rabbit model of surfactant deficiency. The data demonstrate that several peptides, ranging from 17 to 45 residues in length, matching the carboxy-terminal sequence of the SP-B protein, when appropriately recombined with the phospholipid dipalmitoylphosphatidylcholine and phosphatidylglycerol (3:1), are capable of producing a synthetic surfactant with biophysical and biologic activity approaching that of human surfactant derived from amniotic fluid.

The purposes of this study were to determine the current status of physical therapists' preparation to work with handicapped and at-risk infants and their families and to identify needs for infant- and family-focused training materials and curricula. Results of a telephone survey of 73 physical therapy programs and a follow-up mail survey of 14 physical therapy programs with infancy specialization options are presented. Students in entry-level programs and postprofessional master's degree programs with infancy specializations commonly received instruction in infancy-related topics. Many students received minimal or no exposure to family-related content. Family assessment and intervention were identified as the areas of highest priority for development of training materials and curricula. The results of this study provide direction for the design of infant- and family-focused training materials and curricula in physical therapy.

We have compared the kinetics of the responses of neutrophils to the kinetics of ligand-receptor interaction and internalization, using as a model ligand the fluoresceinated hexapeptide N-CHO-Nle-Leu-Phe-Nle-Tyr-Lys-Fluorescein (Nle, norleucine). Cellular responses, ie, membrane depolarization, enzyme (elastase) secretion, and superoxide anion (O-2) generation, are all initiated within 10 sec of the exposure of cells to stimulus. In the cases of membrane depolarization and secretion (in cytochalasin B-treated cells), full responses are elicited by binding which occurs within 15 sec of peptide addition. Ligand binding and internalization have been analyzed over the same time frame with new spectroscopic techniques. The association of ligand and receptor is monitored using an antibody to fluorescein. The antibody to fluorescein specifically quenches the ligand which is in solution, but receptor-bound ligand is inaccessible to the antibody. The internalization of the receptor-bound ligand is monitored by the accessibility of the fluoresceinated peptide to quenching by an external pH change (7.4 leads to 4.0). Ligand which is either outside or on the cell surface is instantaneously quenched while intracellular peptide (or intracellular fluorescein derived from fluorescein diacetate) is only slowly quenched. No internalization is observed until 1 min after binding begins and internalization proceeds at a rate of up to 5,000 receptors/min/cell following a near optimal stimulatory ligand concentration (approximately 1 nM) while the occupied receptors are being cleared from the surface. A comparison of the kinetics of internalization and the cellular responses suggests that internalization of the ligand is too slow to be involved in the triggering of the cellular responses.

Hageman factor was purified from guinea pig plasma by successive column chromatography. The guinea pig Hageman factor appeared homogeneous as a single-chain protein on polyacrylamide gels in the presence of sodium dodecyl sulfate (SDS) and beta-mercaptoethanol. The apparent molecular weight was 76,000 daltons by SDS--polyacrylamide gel electrophoresis and 105,000 daltons by gel filtration with a Sephadex G-150 column. Amino acid composition of the guinea pig Hageman factor was similar to that reported for human, bovine, and rabbit Hageman factors. The purified guinea pig Hageman factor, as well as guinea pig plasma, showed strong clotting time correction activity in Hageman-factor--deficient human plasma. The activity could be blocked by the IgG fraction of antiserums against guinea pig Hageman factor raised in rabbits or a goat. The concentration of Hageman factor in guinea pig plasma was determined to be 120 microgram/ml by quantitative radial immunodiffusion assay. The 28,000-dalton active form of Hageman factor (beta-HFa) was prepared from guinea pig Hageman factor by treatment with plasma kallikrein. beta-HFa caused an increase in vascular permeability when injected into guinea pig skin at concentrations as low as 3 x 10(-10) M (0.8 ng). Native, or zymogen Hageman factor did not cause an increase in permeability at concentrations of up to 2 x 10(-7) M. The increased permeability induced by beta-HFa was short lasting, with about a 50% decrease in activity apparent within 6 minutes after intradermal injection. The permeability enhancement activity of beta-HFa was inhibited by pretreatment of beta-HFa with diisopropylfluorophosphate. It may be concluded that active Hageman factor in the interstitial space of guinea pigs acts as a vascular permeability factor of far greater potency than bradykinin.

Tissue injury of many types may be caused by deposited complexes of antigen and antibody. The circumstances under which the complexes form and deposit often determine the location and type of injury observed: If the complex forms in the circulation, deposition may occur in arterial walls and glomeruli, initiating lesions in those tissues. If the complex forms in the synovial tissues or spaces, then the reaction will develop at that point. Any local source of antigen will initiate these lesions once antibody is formed. If the source of antigen persists, antibody-forming cells soon establish themselves locally as they do in the active Arthus reaction, and injury will become chronic. When the antibody formed is capable of activating complement, polymorphonuclear leukocytes (PMNs, neutrophils) will accumulate, leading to release of injurious constituents. Such is the case in acute glomerulonephritis, arteritis, synovitis, and vasculitis. The ability of complement to attract the PMNs has been demonstrated as an in vitro phenomenon and as a clear possibility in vivo. The requirement of PMNs in the development of the lesions has been demonstrated. The process by which PMNs and other cells (platelets, mast cells, basophils, and macrophages) release injurious constituents is of great interest currently. The exocytosis of their cytoplasmic granules constitutes the major mechanism of release and involves a complicated series of events outlined in this review. The constituents of PMNs capable of injuring tissue in various ways is described, from peptides capable of increasing vascular permeability, to enzymes that indirectly bring more PMNs and other cells into the lesion, to proteolytic enzymes that hydrolyze vital structures in the tissues. These agents were most likely designed to rid the host of invaders; but at times they are unfortunately directed against the host's own tissues.

A protein has been isolated and partially purified from the venom ofNaja naja which causes the noncytolytic release of amines from rat peritoneal mast cells. This protein, termed CVA protein, has been demonstrated to have a molecular weight of 18,500 and sedimentation coefficient of approximately 2s. The activity of CVA protein is destroyed by treatment for 5 min at 100°C, but is not affected at 75°C for 30 min. The ability of CVA protein to initiate mast-cell degranulation has been demonstrated to require both cell energy and calcium. The temperature sensitivity and the cellular requirements distinguish the CVA protein from phospholipase A.

Bronchoalveolar lavage (BAL) fluid was obtained from 24 sequentially studied patients with adult respiratory distress syndrome (ARDS) for assessment of potential activating and mediating factors. Proteolytic activity of the fluids was observed by measuring cleavage of radiolabeled proteins of the contact (Hageman factor) and complement systems. Proteolytic activity was observed in 17 of 24 (71%) patients with ARDS, and BAL fluid of the 7 ARDS patients without demonstrable, active, enzyme exhibited inhibitory activity for the proteolytic activity. The enzymes cleaved Hageman factor, prekallikrein, plasminogen, high molecular weight kininogen, C4, C3, C5, and Factor B of the complement system. Cleavage of the contact system proteins producted fragments similar or identical in size to the fragments observed during activation of these molecules, although continued incubation invariably reduced the protein to small peptide fragments. None of 7 normal individuals, and 29 of 99 patients (29%) with other forms of pulmonary disease contained measurable enzymes. The proteolytic activity in BAL fluid of ARDS patients was blocked by diisopropylphosphofluoridate (0.1 mM), Trasylol, soybean trypsin inhibitor, and normal plasma, or plasma deficient in inhibition of the first component of complement. Alpha(1)-proteinase inhibitor (alpha1-PI)-deficient plasma failed to inhibit the proteolytic activity and addition of alpha1-PI to the deficient plasma reconstituted the inhibition. MUCH OF THE PROTEOLYTIC ACTIVITY OF THE BAL FLUID FROM ARDS PATIENTS WAS IDENTIFIED AS NEUTROPHIL ELASTASE: the fluids cleaved elastin and synthetic peptide substrate of neutrophil elastase, neutrophil elastase antigen was present in the BAL fluids as determined immunologically using antineutrophil elastase, alpha1-PI was the major inhibitor in plasma, and the enzyme was inhibited by diisopropylphosphofluoridate but not chelation. In addition, purified neutrophil elastase produced cleavage fragments of proteins of the contact system similar to those of the BAL fluids. In each of the seven BAL fluids of ARDS patients that did not reveal active elastase, alpha1-PI was present in active form (as determined by (125)I-trypsin binding). In 9 of the 17 patients with active elastase in the BAL fluid, alpha1-PI antigen was present in the fluid, but was inactive (no binding of (125)I-trypsin). Immunoelectrophoretic analysis of elastase and alpha1-PI throughout proteins in these BAL fluids revealed the presence of both elastase and alpha1-PI that migrated with the same R(f), suggesting the presence of an enzyme-inhibitor complex. Free, inactive alpha1-PI was also observed in these fluids. The data reveal that in BAL fluids from all 24 patients with ARDS, leukocytic elastase and/or alpha1-PI exist. A complex of elastase and alpha1-PI was observed in BAL fluids, and in some cases where active enzyme and alpha1-PI coexisted, free, but inactive alpha1-PI was present.

Various biochemical events taking place during pulmonary inflammation were examined in the bronchoalveolar lavage (BAL) fluids from patients with acute respiratory distress syndrome (ARDS) and in experimental animal models. In patients with ARDS, active neutrophil elastase was found in the BAL fluids. In these fluids, inactivation of the major elastase inhibitor alpha 1-protease inhibitor (alpha 1-PI) occurred. This was caused by oxidation of a methionine residue at the active site of the alpha 1-PI, and offered indirect evidence of oxidation occurring in the inflamed pulmonary tissues. Studies with experimental animals have been initiated to gain understanding of the relative roles of proteases, oxidants, arachidonate metabolites, complement and contact system components, and other mediators in the pathogenesis of pulmonary inflammation. Intrabronchial instillation of glucose oxidase/glucose to produce oxidants or formylated norleucylleucylphenylalanine or phorbol myristate acetate as leukocytic stimuli induced severe acute pulmonary injury in New Zealand white rabbits and rhesus monkeys. The injury was accompanied by leukocytic protease (acid cathepsins) release in rabbit lungs and oxidant formation, and could be inhibited by neutrophil depletion. Oxidant formation was demonstrated by the inactivation of catalase by 3-amino-1,2,4-triazole in the presence of H2O2, a drop in intracellular glutathione levels, and in the rhesus monkey by inactivation of alpha 1-PI.

The crucial role of leukocytes in host defense is well known. It is becoming increasingly clear, however, that in addition to their beneficial effects, leukocytes can also cause significant injury to host tissues. In this article, the authors review some of the experimental evidence that supports the role of leukocytes in tissue injury.

Various flower bulbs and vegetable and legume seeds were tested for inhibitors of polymorphonuclear leukocyte elastase, pancreatic elastase, cathepsin G, cathepsin B, trypsin, alpha-chymotrypsin, Hageman factor fragments, plasma kallikrein, and plasmin. Calla bulbs contained a 33,000 dalton polymorphonuclear leukocyte elastase inhibitor and a 4,000 dalton cathepsin G inhibitor. Seeds of some members in the Cruciferae family, such as radish and broccoli, were found to contain one or more 2,500-4,000 dalton inhibitors which inhibited cathepsin G, trypsin, Hageman factor fragments, and plasmin, but not plasma kallikrein. These seeds also contained a 1,000 dalton cathepsin B inhibitor. The above inhibitors were probably polypeptides which inhibited proteinases by making an enzyme-inhibitor complex, with the exception of the cathepsin B inhibitor. These newly found inhibitors with their characteristic profiles of inhibition should be useful in biochemical and pathophysiological studies on granulocyte proteinases and enzymes of the coagulation and fibrinolytic pathways.

We earlier reported the IgE-mediated release of a basophil kallikrein of anaphylaxis (BK-A) which, like plasma kallikrein, is an arginine esterase and cleaves human plasma kininogen generating immunoreactive kinin. We herein report that, like plasma kallikrein, preparations rich in this basophil protease also activate human Hageman Factor by proteolytic cleavage of the zymogen molecule into light and heavy chains. These fragments of 28,000 and 52,000 daltons are similar in size to those produced during activation of Hageman Factor by plasma kallikrein. Exposure of Hageman Factor (bound to a negatively charged surface) to BK-A led to the proteolytic cleavage of Hageman Factor producing a 28,000 molecular weight fragment (HFa) which is functionally active and capable of activating prekallikrein to kallikrein. We conclude that, during anaphylaxis, basophils may release a protease that is capable of cleaving and activating Hageman Factor, thus providing a mechanism for initiating the in vivo activation of the Hageman Factor dependent systems.

Neutrophil homogenates contained a high affinity guanosine triphosphatase (GTPase) that was stimulatable (+27%) by the addition of 100 nM N-formyl chemotactic peptide (CHO-pep), but not by 1 microgram X ml-1 phorbolmyristate acetate (PMA). Kinetic analysis of the stimulation demonstrated an apparent lagtime of 14.3 +/- 6.9 s between the addition of CHO-pep and the optimal GTPase stimulation. The GTPase activity (but not CHO-pep-stimulated GTPase activity) was preserved in a highly purified plasma membrane fraction of the homogenate. From these observations we suggest that both a high affinity guanine nucleotide binding protein and GTPase are closely associated with the plasma membrane CHO-pep receptor. The possibility that GTPase activity may influence guanine nucleotide regulation of adenylate cyclase during CHO-pep stimulation of neutrophils is discussed.

Rabbit Hageman factor was proteolytically cleaved and activated by a homogenate prepared from cultured rabbit endothelial cells. Cleavage of radiolabeled Hageman factor was monitored by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Endothelial cell-mediated cleavage of Hageman factor was demonstrated both in a purified system and in plasma, was time and concentration dependent, and was associated with formation of the characteristic 28,000 M(r) form of active Hageman factor. The rate of cleavage of Hageman factor was not affected by Triton X-100 (Rohm and Haas, Co., Philadelphia, Pa.), hexadimethrine bromide (Polybrene, Aldrich Chemical Co., Inc., Milwaukee, Wis.), hirudin, soybean trypsin inhibitor, or antisera to plasminogen or prekallikrein. However, cleavage was enhanced by kaolin, and was inhibited by diisopropyl-fluorophosphate. The enzyme responsible for cleavage of Hageman factor was localized to the 100,000-g-sedimentable, subcellular fraction of the endothelial cell homogenate and was relatively specific, because neither radiolabeled rabbit Factor XI nor rabbit prekallikrein were themselves proteolytically cleaved by the endothelial cell homogenate. However, when these molecules were incubated with the homogenate in the presence of Hageman factor, both Factor XI and prekallikrein were cleaved, demonstrating that Hageman factor had been activated by the endothelial cell homogenate. Furthermore, the kallikrein generated by endothelial cell homogenate-activated Hageman factor was capable of liberating kinin from high molecular weight kininogen as measured by bioassay. Cultured rabbit endothelial cells, therefore, possess the capacity to activate Hageman factor by proteolysis. This may be one mechanism for Hageman factor activation in vivo.

The mechanism by which the Hageman factor-dependent system induces vascular permeability has been analyzed. The Mr-28,000 active fragment of guinea pig Hageman factor (beta-HFa), injected intradermally, induces an increase in local vascular permeability. Inhibition of vascular permeability resulted from pretreatment of the beta-HFa with immunopurified anti-Hageman factor F(ab')2 antibody at concentrations of 10(-6)-10(-7) M as well as by incubation with corn and pumpkin seed inhibitors of beta-HFa. To determine whether prekallikrein and kallikrein participated in the permeability induced by beta-HFa, circulating prekallikrein was depleted by intra-arterial injections of anti-prekallikrein F(ab')2 antibody. This resulted in about 80% diminution of the vascular permeability response to beta-HFa, without affecting the permeability reaction to bradykinin. Soybean trypsin inhibitor (10(-6) M), injected at the same cutaneous site as the beta-HFa, inhibited the vascular permeability response to beta-HFa by more than 90%. This concentration of soybean inhibitor blocked more than 90% of the activity of guinea pig plasma kallikrein, but did not inhibit the amidolytic capacity of beta-HFa. The permeability activity of beta-HFa (but not its amidolytic activity) was augmented 10-fold by simultaneous injection of a synthetic kinin potentiator, SQ 20,881 (Glu-Tyr-Pro-Arg-Pro-Gln-Ile-Pro-Pro-OH), and was almost completely inhibited by the simultaneous injection of a kinin-destroying enzyme, carboxypeptidase B. These results support the hypothesis that the greatest proportion of vascular permeability induced by beta-HFa is produced by the activation of prekallikrein followed by the release of kinin in the cutaneous tissue. These data offer the first in vivo evidence that the Hageman factor-dependent system by itself can induce inflammatory changes.

A large number of negatively charged macromolecules, including DNA, glycosaminoglycans, and proteoglycans, were tested as possible activators of the contact (Hageman factor) system in vitro. Activation was assessed by conversion of prekallikrein to kallikrein, as determined by amidolytic assay and by cleavage of 125I-Hageman factor into 52,000- and 28,000-dalton fragments. Of particular interest to these studies, heparin proteoglycan and glycosaminoglycan from rat peritoneal mast cells, and squid chondroitin sulfate E, which is representative of the glycosaminoglycan from cultured mouse bone marrow derived mast cells, induced the reciprocal activation between Hageman factor and prekallikrein. In addition, naturally occurring heparin glycosaminoglycans from pig mucosa, bovine lung, and rat mast cells also induced activation. In contrast, native connective tissue matrix glycosaminoglycans and proteoglycans from several sources were inactive, although when one such chondroitin sulfate was further sulfated in vitro, it gained activity. When the negative charge of the activating agents was blocked by the addition of hexadimethrine bromide, the cleavage of 125I-Hageman factor in the presence of prekallikrein was prevented. The active negatively charged macromolecules induced cleavage of 125I-high molecular weight kininogen in normal plasma but not in Hageman factor-deficient or prekallikrein-deficient plasmas. Reconstitution of prekallikrein-deficient plasma with purified prekallikrein restored the kininogen cleavage upon addition of the active proteoglycans. These results suggest that both heparin from connective tissue mast cells and highly sulfated chondroitin sulfate E from cultured mouse bone marrow derived mast cells (which are considered synonomous with mucosal mast cells) could activate the contact system of plasma subsequent to an activation secretion response.

An in vitro test for the rate of appearance of kallikrein in plasma due to contact system activation by dextran sulfate at 0 degree C was applied to plasmas of 19 atopic asthma patients and 19 age- and sex-matched controls without atopy. The average prekallikrein activation rate was markedly higher in the plasmas of the atopic patients. Mean endogenous heparin levels were also elevated.

Human granulocytes were disrupted by nitrogen cavitation and the lysates fractionated by sucrose density gradient centrifugation at 83000 X g for 20 min (rate zonal) or 3.5 h (isopycnic). The distribution of marker enzymes allowed the identification of the following subcellular components: plasma membrane, Golgi, endoplasmic reticulum, azurophil granules, specific granules, mitochondria and cytosol. Examination of the gradient fractions by electron microscopy confirmed the biochemical marker analysis. The protocol permitted isolation of vesicles highly enriched in either plasma membrane or Golgi (galactosyl transferase) activities. Absolute plasma membrane yields of 40-60% were achieved with a 20-70-fold increase in specific activity of surface marker over the cells. Plasma membrane sedimented to an average density of 1.14 g X cm-3. Galactosyl transferase activity was bimodal in distribution. The denser peak cosedimented with specific granules (p = 1.19). The lighter peak sedimented to unique position at an average density of 1.11, was enriched 18-fold over the low speed supernatant, and contained structures resembling Golgi. N-Formyl-Met-Leu-Phe binding and Mg2+-ATPase activities cosedimented with the plasma membrane as well as specific granule and/or high density galactosyl transferase fractions. These findings suggest that Mg2+-ATPase and N-formyl chemotactic peptide receptor activities may be localized in an internal pool of membranes as well as in the plasma membrane and that Golgi may have been a contaminant of previous granulocyte plasma membrane or specific granule preparations.

The concentration of macrophages per gram tumor was as much as five times greater in regressing compared to progressing Moloney sarcomas. Infiltrating monocular cells, including macrophages, were closely associated with a cessation of mitotic activity in tumors.

The experimental results summarized here suggest a mechanism of oxidant induced cell injury which begins with the generation of DNA strand breaks. The mechanism of the generation of these breaks is currently under investigation. The presence of DNA strand breaks activates pADPr polymerase which causes the conversion of cellular NAD to pADPr and free nicotinamide. It is likely that low levels of NAD are associated with inhibition of glycolysis and thereby contribute to the oxidant-induced fall in cell ATP. Additional factors are likely to contribute to altered cell metabolism following oxidant injury. Hyslop has shown that the Vmax of a critical enzyme of the glycolytic pathway, glyceraldehyde-3-phosphate dehydrogenase, is decreased following exposure to oxidant. Finally, it is likely that the oxidative phosphorylation functions of the mitochondrial membrane may also be perturbed by oxidant injury. The extent to which these alterations in cell metabolism occur in vivo following exposure to oxidants may be of great importance to our understanding of acute inflammatory tissue injury.

Quantitative analysis of ligand-occupied receptor interactions with elements of the cytoskeleton and with intracellular compartments requires a sensitive and simple method of identifying the receptor-ligand complex in living cells. Toward this goal, we have prepared a photoactivatable arylazide derivative of the chemotactic peptide N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys, which can be radiolabeled to high specific activity with 125I. This derivative was biologically active as judged by its ability to elicit superoxide anion production by human PMNL at nanomolar concentrations (ED50 approximately 0.7 nM). When incubated at 0 degree C with whole PMNL, radioactive ligand became specifically and saturably associated with a 60-70,000-dalton species (as assessed by SDS-PAGE) after exposure to UV light. Addition of 10-100-fold excess of unlabeled parent or unlabeled azidopeptide derivative completely blocked uptake into this species. Approximately 20-40% of the available surface receptor-binding sites were covalently labeled under these conditions. Subcellular fractionation of the labeled cells on sucrose gradients after homogenization showed that the labeled species was primarily associated with plasma membrane-rich fractions. The labeled receptor could be completely solubilized with Triton X-100 in a form which eluted as a single species with a Stoke's radius of less than 50 A on Sepharose 4B columns. In addition, the solubilized receptor-ligand complex bound specifically to wheat germ agglutinin, indicating that it is probably a glycoprotein. The ability to label the receptor in living PMNL with a high efficiency should facilitate the study of receptor dynamics and receptor physiochemical properties in this system.

Purified precursor Hageman factor has been demonstrated to bind to soluble bacterial lipopolysaccharide (LPS, endotoxin) isolated from Escherichia coli 0111:B4, and this complex has been shown to have the capacity to convert prekallikrein to its active form. In addition, LPS-activated Hageman factor substantially reduces clotting times in XII-deficient plasma. The capacity to activate Hageman factor has been demonstrated to reside in the lipid A region of the LPS molecule. Activation of Hageman factor by LPS contrasts with fluid-phase activation (e.g., by kallikrein or trypsin) in that no cleavage to lower molecular weight fragments occurs. High concentrations of LPS inhibit the activity of Hageman factor, probably by a direct LPS-Hageman factor interaction.

To study the penetration of alpha 1-proteinase inhibitor (A1Pl) into the lungs of healthy dogs, 83 mg/kg of active A1Pl was administered intravenously over 30 min followed by a bolus of 131I-A1Pl. Animals were lavaged 2 to 72 h after infusion, sequential gamma camera scans were acquired, and urine was analyzed for the excretion of desmosine. After a distribution phase, infused A1Pl left the bloodstream with a half-life of 103 +/- 24 h. Analysis of plasma antiprotease activity demonstrated preservation of function of the infused A1Pl. Lavage fluid A1Pl concentration and activity were significantly increased 24 h after infusion. Gamma camera scans demonstrated that lung, liver, and spleen acquired 131I-A1Pl similarly; radioactivities per gram of tissue of these organs were similar at autopsy. Excretion of desmosine did not decrease from a baseline of 157 +/- 59 nmol/24 h after A1Pl infusion, indicating no effect of A1Pl infusion on background elastolysis. These data suggest that intravenous administration of A1Pl can raise lung antiproteinase levels within 24 h despite the absence of preferential uptake by the lung of the infused protein.

The structure of Hageman factor, isolated from human plasma, was analyzed before and after enzymatic activation. The purified molecule is a single polypeptide chain of 80,000 molecular weight (mol wt) sedimenting at 4.5S. An amino acid analysis has been performed. The concentration of Hageman factor in normal human plasma was found to be 29 mug/ml with variation between individuals ranging from 15 to 47 mug/ml. Treatment of the molecule with kallikrein, plasmin, or trypsin resulted in cleavage at two primary sites, yielding fragments of 52,000, 40,000, and 28,000 mol wt. No further changes occurred in the fragments with subsequent reduction. Prekallikrein-activating ability was associated exclusively with the 28,000 moiety.

Six suction-induced blister fluids obtained from five patients with hereditary angioedema (HAE) contained active kallikrein, whereas only two blister fluids obtained from eight normal volunteers contained small amounts of this activity. Kallikrein was present in large amounts of HAE blister fluids as assessed by its ability to liberate smooth-muscle-contracting activity from purified high molecular weight kininogen. It was inhibited by purified antibodies specific for plasma prekallikrein and also by purified C1 inhibitor, but not by antibodies specific for C1s. These observations suggest that activation of the Hageman-factor-dependent pathways occurs in the tissues of HAE patients, and once generated, active kallikrein persists in these tissues.

Using an enzyme-linked immunosorbent assay, we measured the concentration of fibronectin containing an extra type III domain (ED1) in the circulation of humans. Plasma levels of ED1 + fibronectin averaged 2.8 +/- 1.0 micrograms/ml in healthy individuals and did not differ substantially according to age or sex. In comparison with those from normal subjects, plasma samples obtained from patients with collagen vascular disorders contained increased average levels of ED1 + fibronectin. Among this group, levels of ED1 + fibronectin were significantly greater in samples taken from individuals with clinical evidence of vasculitis. Although levels of total (ED1 + plus ED1 -) fibronectin were also elevated in plasma samples from patients with vasculitis, only the concentration of the ED1 + variant correlated with severity of disease in two patients examined serially. Elevations in plasma content of ED1 + fibronectin, but not total fibronectin, were also noted in patients with acute vascular tissue injury associated with major trauma or sepsis syndrome. Western blot examination revealed the presence of intact dimeric ED1 + fibronectin in the circulation of all patients studied, although fragments bearing the ED1 were also detected. Human plasma normally contains small quantities of soluble ED1 + ("cellular") fibronectin, and these levels are increased in disorders involving vascular injury.

Binding of purified monoclonal antibody (moAB) IgM NMS-1 to suspended initially spherical living human PMNLs is not associated with the generation of chemiluminescence but was found to enhance the chemiluminescence response to the N-formyl chemotactic peptide FNLPNTL. We investigated quantitatively the kinetics of oxygen metabolite generation by PMNLs stimulated with FNLPNTL +/- moAB NMS-1 using luminol-dependent chemiluminescence as a very sensitive detection system. Chemiluminescence detection allowed the analysis of the time sequence of onset and development of reactive oxygen metabolites following stimulation of PMNLs by FNLPNTL in the presence of moAB NMS-1. The increase of response of PMNLs stimulated with FNLPNTL in the presence of moAB NMS-1 depended on the concentration of the antibody and the sequence of stimulus addition. Stimulation of human PMNLs by 10 nM FNLPNTL induced a rapid burst of chemiluminescence which peaked approximately 5 min after stimulus addition. The subsequent addition of moAB NMS-1 (greater than or equal to 2 micrograms/ml DPBS(+) - 0.1% HSA, 37 degrees C) to FNLPNTL-stimulated PMNLs - after the FNLPNTL-mediated response had already decayed (16-18 min) - without delay induced a second burst of oxygen metabolite generation. The magnitude of this second peak of activation was dose-dependent. Treatment of PMNLs with moAB NMS-1 (greater than or equal to 1 microgram/ml DPBS(+) - 0.1% HSA, 3 min, 37 degrees C) - prior to FNLPNTL (10 nM) stimulation - increased rate and magnitude of the FNLPNTL-mediated response. This response is biphasic with the first peak at the FNLPNTL position and a second, higher peak approximately 16 min after FNLPNTL addition. The magnitude of response was dose-dependent. The latency (lag time) of the response was not changed compared to controls which received no moAB NMS-1 treatment. The observed moAB NMS-1 dependent increase in FNLPNTL-mediated chemiluminescence is transient (50-60 min), persistent activation was not detected.

To examine the role of complement (C3) in determining the fate of lipopolysaccharide (LPS) in vivo, the distribution of LPS was studied in normocomplementemic (NC) and C3-depleted animals (pretreated with cobra venom factor [CoF]) after intravenous injection of highly purified, radioiodinated Salmonella minnesota R595 LPS. After injection of a lethal (250 micrograms) or nonlethal (5 micrograms) dose of LPS in NC and CoF rabbits and a lethal (5 mg/kg) dose of LPS in rhesus monkeys, the LPS disappeared from blood in a biphasic manner. In all cases, a substantial portion of the dose was removed from blood in an initial disappearance phase (t1/2 < 15 minutes), which, in some cases, was accelerated in CoF-treated animals. LPS remaining in blood beyond 30 minutes persisted with a much increased half-life (> 5 hours). Liver contained the major portion (40%) of tissue-bound LPS (determined by use of 131I-BSA blood marker) in animals killed 3--5 hours after injection. The distribution of LPS in rabbits was found to be dose-indpendent and only minimally changed by prior depletion of C3. In addition, the tissue distribution and cellular localization of LPS in monkeys was similar to that we have reported previously for R595 LPS in NC rabbits and was not substantially changed by prior CoF treatment. These results indicate that binding of C3 to intravenously injected LPS is not required for the initial rapid disappearance from blood. Further, the uptake of LPS by cellular targets, notably the hepatic macrophages (Kupffer cells), is not altered by in vivo decomplementation.

Pulmonary effluent from infants who received exogenous human surfactant for severe respiratory distress syndrome was evaluated for inflammatory changes previously identified with lung injury during the first 2 weeks after birth. The number of pulmonary effluent inflammatory cells was higher only on day 1 in infants given surfactant. No other evidence of enhanced inflammation was detected in cytologic assessment of tracheal secretions. The classical pathway of complement was not activated in infants given surfactant or in control infants 2 weeks after birth. Albumin content of airway secretions was higher on the first day but not significantly altered on subsequent days. Human surfactant treatment was not associated with increased proteolytic activity, measured as neutrophilic elastase per milligram of albumin in lung effluent, but was associated with significantly higher alpha 1-proteinase inhibitor levels than in control infants from days 2 to 7 after birth. These findings provide evidence that exogenous human surfactant instilled into the lungs of preterm infants with severe respiratory distress syndrome is not associated with enhanced lung inflammation, compared with conventional mechanical ventilation alone. These data support additional clinical trials using human surfactant.