Purification and characterization of a novel soluble receptor for interleukin 1.

Affinity chromatography and reverse-phase high-performance liquid chromatography was used to purify a soluble interleukin 1 beta (IL-1 beta) specific binding protein from the supernatant of a human B cell line, Raji. The purified protein specifically bound 125I IL-1 beta forming a 60-kD complex in nonreducing conditions and a 70-kD complex in reducing conditions. Binding was found to be displaceable by mature human and murine IL-1 beta and human 31-kD IL-1 beta propeptide, but not displaceable by human and murine IL-1 alpha or human IL-1 receptor (IL-1R) antagonist. Ligand blotting revealed a 47-kD molecule that specifically bound IL-1 beta. Measurement of binding affinity of the cell surface Raji IL-1R (Kd = 2.2 nm) and the Raji soluble (s)IL-1R (Kd = 2.7 nm) demonstrated a similar affinity for 125I IL-1 beta. Purified sIL-1R inhibited binding of IL-1 beta to cell lines with both type I (80 kD) and type II (65 kD) IL-1Rs, but did not interfere with IL-1 alpha binding. This natural sIL-1R may function as an important regulatory molecule of IL-1 beta in vivo.

Hematopoietic growth factor induction of gamma-glutamyl transferase in the KG-1 myeloid cell line.

The enzyme gamma-glutamyl transferase (GGT) is a multifunctional enzyme that participates in a number of metabolic processes, including the conversion of leukotriene C4(LTC4) to leukotriene D4(LTD4). LTD4 is necessary for normal myeloid proliferation and differentiation. We have examined the ability of hematopoietic growth factors (HGF) to induce GGT enzyme activity and mRNA content in a HGF-responsive cell line (KG-1). Incubation of KG-1 with recombinant human cytokines interleukin-1 beta (IL-1 beta), interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor (TNF), but not interleukin-6 (IL-6), granulocyte colony-stimulating factor (G-CSF) or monocyte colony-stimulating factor (M-CSF), results in significant increases in GGT enzyme activity. The increases in GGT activity are both dose- and time-dependent. In response to IL-1, increases in enzyme activity are seen by 6 hours and activity is maximal by 24 hours. GGT mRNA increases also occur and peak by 3 to 6 hours. These results indicate that induction of increases in GGT mRNA levels and enzyme activity occur in myeloid cells in response to HGFs. This induction, together with the requirement for LTD4 for normal granulopoiesis, supports a role for GGT in the cellular events occurring in myeloid cells in response to HGFs.

Identification of an interleukin-1 beta binding protein in human plasma.

A covalent cross-linking technique was used to bind iodinated interleukin-1 (IL1) alpha and beta to plasma proteins. One specific IL1 beta binding protein was observed, that when cross-linked to 125I-IL1 beta migrated to approximately 60 kDa on SDS-PAGE. The protein did not bind IL1 alpha. The 43 -kDa protein was partially purified using a wheat germ agglutinin affinity column. The isolated factor again specifically bound IL1 beta, and appeared to consist of single chain glycoprotein. The protein was heat stable and had a rapid association time with IL1 beta. This protein may be an important carrier molecule for IL1 beta in vivo.

Fatal and nonfatal accidents on the railways--a study of injuries to individuals, with particular reference to children and to nonfatal trauma.

This paper reports a five-year total population study of fatal railroad accidents involving individuals (that is, not including train crashes or derailments); and a consecutive unselected series of nonfatal isolated injuries in Queensland, Australia. There were 84 fatalities and 211 cases of significant nonfatal traumata. Fatal railway accidents involving children under 15 years of age are now more common in Australia than childhood poisonings and electrocutions. Two syndromes occur--(a) toddlers living near the tracks who simply wander onto the line; and (b) young teenage boys who are run down on level crossings, either as pedestrians or cyclists. Adult fatalities include (a) occupational deaths among railway workers (20%), (b) car-train collisions at level crossings (19%), (c) drunk pedestrians who walk into trains (17%), suicides (12%), and old folk who walk into trains (12%). Of 211 nonfatal cases studied, falls in and from both moving and stationary trains were the most common type of accident. Sudden jolting of the train (probably unpreventable) contributed to 26% of all falls. Twenty-two percent of nonfatal accidents resulted from a person being struck by a train. All persons who survived being struck by a train received serious injuries and required hospital admission. Fatalities involving adults include a high proportion of suicides. Some accidents, such as fingers being caught in windows and doors, can and are being overcome through improved design.

Erwinia amylovora: the molecular basis of fireblight disease.

UNLABELLED: Summary Taxonomy: Bacteria; Proteobacteria; gamma subdivision; order Enterobacteriales; family Enterobacteriaceae; genus Erwinia. Microbiological properties: Gram-negative, motile rods. Related species:E. carotovora (soft-rot diseases), E. chrysanthemi (soft-rot diseases), E. (Pantoea) stewartii (Stewart's wilt of corn), E. (Pantoea) herbicola (epiphyte). HOST RANGE: Affects rosaceous plants, primarily members of the Pomoideae. Economically important hosts are apple and pear. The commercial implications of fireblight outbreaks are aggravated by the limited effectiveness of current control measures. Disease symptoms:E. amylovora infection is characterized by water soaking of infected tissue, followed by wilting and tissue necrosis. Necrosis gives tissue a scorched, blackened appearance, giving rise to the name fireblight. Symptoms are often localized to blossom bracts or young shoots but, in highly susceptible hosts, can spread systemically resulting in death of the entire tree. Infections can vary in severity depending on climatic conditions and host susceptibility. Useful web site:http://www.agric.gov.ab.ca.

Long-term outcome of depressed children: a follow-up study.

Nineteen subjects diagnosed as clinically depressed in childhood were followed up seven to eight years after first presentation. The group was highly symptomatic when originally seen, a large proportion presenting with physical complaints. The outcome at follow-up was variable, but 42 per cent still had moderate or severe disability. This small study emphasises the need for further detailed investigation of the long-term outcome of children with a depressive disorder.

A soluble binding protein specific for interleukin 1 beta is produced by activated mononuclear cells.

Soluble interleukin 1 (IL 1) binding proteins were identified by gel filtration and covalent cross-linking of 125I IL 1 in normal human serum and inflammatory exudate. High molecular weight 125I IL 1 protein complexes occurred with both IL 1 alpha and IL 1 beta, however, high molecular weight binding appeared to be non-specific. One specific IL 1 beta binding protein was observed to elute at approximately 100 kDa on gel filtration when bound to 125I IL 1 beta. This complex migrated as a broad band at 60 kDa when covalently cross-linked and analyzed by SDS-PAGE. The protein did not bind 125I IL 1 alpha and 125I IL 1 beta binding was only displaceable by excess cold IL-1 beta. The production of the specific IL 1 beta binding protein was assessed in a number of cell populations. Unstimulated peripheral blood mononuclear cells (PBMNC) did not produce the binding protein, but stimulation with phytohemagglutinin (PHA) caused production within 24 hr and binding protein levels remained elevated for up to 7 days. Stimulation with lipopolysaccharide (LPS) and IL 1 alpha did not consistently induce synthesis of the binding protein. Ligand-binding studies were performed to compare solubilized EL 4 NOB.1 cell membrane IL 1 receptor (sIL 1R) with semi-purified IL 1 beta binding protein from pooled synovial fluid. The sIL 1R preparation bound ligand with an affinity of 168 pM while the IL 1 beta binding protein bound 125I IL 1 beta with an affinity of 370 pM. This protein may function as an important carrier molecule for IL 1 beta and determine its distribution and kinetics in vivo.

Ventricular arrhythmias during treatment with alteplase (recombinant tissue plasminogen activator) in suspected acute myocardial infarction.

Continuous electrocardiography during the first 24 hours of a stay in a coronary care unit was used to record ventricular arrhythmias during treatment with alteplase (recombinant tissue plasminogen activator) or placebo. Recordings were made on 378 of the 436 patients admitted to a double blind trial of alteplase or placebo in one participating centre of the Anglo-Scandinavian study of early thrombosis (ASSET), patients being selected according to the availability of recorders. Of these, 309 (158 given alteplase and 151 placebo) had greater than 5 hours of analysable data. Most of the arrhythmias were recorded in patients with an in hospital diagnosis of myocardial infarction. Ventricular couplets and ventricular tachycardia were significantly more common in the patients treated with alteplase. Further, in patients with myocardial infarction who had ventricular extrasystoles, couplets, or ventricular tachycardia type a, the number of hours in which each arrhythmia was recorded was significantly higher in the alteplase group. The various ventricular arrhythmias in the alteplase group tended to cluster in the first 4-12 hours of the recordings. During the first 24 hours admission there were four episodes of ventricular fibrillation in the alteplase group and five in the placebo group of taped patients. By one month there had been 18 deaths in these 309 patients (alteplase four, placebo 14). These bore no relation to any recorded arrhythmia. Clinical records for the patients with no or minimal tape data yielded six further episodes of ventricular fibrillation during the first 24 hours (three in the alteplase group and three in the placebo group). Of the total 436 patients, 10 of the 218 patients in the alteplase group had died by one month compared with 22 of the 218 patients treated with placebo. The use of alteplase increases the incident of non-life threatening ventricular arrhythmias. These results, however suggest that arrhythmia after thrombolysis in the pre-hospital phase may be less of a problem than it is perceived to be.

Identification and characterization of the Erwinia amylovora rpoS gene: RpoS is not involved in induction of fireblight disease symptoms.

The Erwinia amylovora rpoS gene, encoding the alternative sigma factor RpoS, has been cloned and characterized. Though highly sensitive to a number of environmental stresses, an E. amylovora rpoS mutant was not compromised in its ability to grow or cause disease symptoms within apple seedlings or in an overwintering model.

A role for manganese superoxide dismutase in radioprotection of hematopoietic stem cells by interleukin-1.

Pretreatment with interleukin-1 (IL-1) has been shown to protect mice from the myelotoxicity associated with irradiation via a mechanism potentially mediated through the induction of the antioxidant enzyme manganese superoxide dismutase (MnSOD). In this study, we have compared the ability of IL-1 to induce MnSOD mRNA in murine bone marrow cells and human cell lines with its ability to protect these cells against the damaging effects of ionizing radiation. Bone marrow cells obtained from mice 6 hours after a single injection of IL-1 demonstrate a dose-dependent increase in the expression of MnSOD RNA. In this same study, IL-1 was also shown to be radioprotective when given to mice 20 hours before lethal irradiation. Similarly, in vitro treatment with IL-1 of bone marrow cells isolated from 5-fluorouracil-treated mice results in elevated levels of MnSOD RNA. Pretreatment with IL-1 also protected bone marrow long-term culture-initiating cells capable of reconstituting irradiated stromal cultures from an irradiation insult. Furthermore, IL-1-treated human bone marrow cells display both elevated MnSOD RNA and protein levels when compared with media controls. The human A375 melanoma, A549 adenocarcinoma, and factor-dependent TF-1 leukemic cell lines demonstrate low basal MnSOD RNA levels that increase following treatment with IL-1. For the A375 cells, this correlates with increased MnSOD protein expression and radioprotection by IL-1 using a colony assay. In contrast, the chronic myelogenous leukemic cell line, K562, displays a high basal MnSOD RNA level, and this RNA expression is not further increased by IL-1 treatment. In addition, these cells are comparatively radioresistant and are not further protected by IL-1 treatment. Finally, the Mo-7 cell line displays a low basal level of MnSOD RNA that correlates with a high sensitivity to irradiation and IL-1 pretreatment has no effect on MnSOD RNA levels. Our results indicate that increased radioprotection by IL-1 correlates with the induction of the antioxidant enzyme MnSOD and this induction may be an important factor in IL-1 radioprotection.

Plasma levels of interleukin-1-alpha in rheumatoid arthritis.

Interleukin-1-beta (IL-1 beta) has been implicated as an inflammatory mediator in rheumatoid arthritis (RA) but little is known about the related cytokine, IL-1 alpha, in this disease. IL-1 alpha has biological properties similar to IL-1 beta but, unlike IL-1 beta, remains mostly cell-associated. In this study plasma IL-1 alpha was measured by radioimmunoassay in patients with RA and in healthy controls. Plasma levels were compared with conventional measures of disease activity. The mean levels in the two groups were not significantly different and, within the patient group (n = 53), the only significant cross-sectional correlation was between plasma IL-1 alpha and ESR. In longitudinal studies, some individual patients had plasma IL-1 alpha levels that correlated with different measures of disease activity. We conclude that while IL-1 alpha may be involved in the immunopathogenesis of RA, its measurement in plasma seems to offer little of clinical value.

Cloning, expression, and characterization of the lon gene of Erwinia amylovora: evidence for a heat shock response.

The gene encoding the Lon protease of Erwinia amylovora has been cloned by complementation of an Escherichia coli lon mutant. Analysis of the determined nucleotide sequence of the lon gene revealed extensive homology to the nucleotide sequences of cloned lon genes from E. coli, Myxococcus xanthus, and Bacillus brevis. The predicted amino acid sequence of the E. amylovora Lon protease was 94, 59, and 54% identical to the predicted amino acid sequences of the Lon proteases of E. coli, M. xanthus, and B. brevis, respectively. The -10 and -35 promoter regions of the cloned lon gene had extensive homology to the respective consensus sequences of E. coli heat shock promoters. Promoter mapping of the lon gene located the start site 7 bases downstream of the -10 region. Cloning of the lon promoter upstream of a cat reporter gene demonstrated that expression of the E. amylovora lon gene was inducible by a heat shock. This is the first demonstration of a heat shock-regulated gene in E. amylovora. Site-directed mutagenesis of the -10 region of the lon promoter confirmed that the heat shock expression of the E. amylovora lon gene may be mediated by a sigma 32-like factor. Insertional inactivation of the E. amylovora chromosomal lon gene confirmed that the lon gene was not essential for either vegetative growth or infection of apple seedlings. E. amylovora lon mutants had increased sensitivity to UV irradiation and elevated levels of extracellular polysaccharide, suggesting comparable roles for the Lon proteases in both E. amylovora and E. coli.

Correlation of plasma interleukin 1 levels with disease activity in rheumatoid arthritis.

The mean plasma level of interleukin 1 beta (IL-1 beta), measured by immunoassay, was significantly higher in 51 patients with rheumatoid arthritis (RA) than in 21 healthy controls of similar age. Further, in the RA group, plasma IL-1 beta correlated positively with Ritchie joint index, pain score, and erythrocyte sedimentation rate and correlated negatively with haemoglobin concentration. In individual patients with active disease who had serial measurements, plasma IL-1 beta also correlated with clinical disease activity. These results support the idea that IL-1 beta has a central role in the pathogenesis of RA.