Coding of COPD Exacerbations and the Implications on Clinical Practice, Audit and Research.

International Classification of Disease 10 (ICD-10) codes record hospital admissions. We aimed to measure the accuracy of COPD exacerbation (ECOPD) codes and examine coding practices for COPD exacerbation.Prospective screening and ICD-10 codes were used to identify potential ECOPD within the DECAF internal validation cohort. Two coding searches were performed. The first search identified patients with an ECOPD discharge code, and a second, broad search was developed to identify all clinically confirmed ECOPD.717 of 1,122 (64%) patients with an ECOPD code had confirmed ECOPD. Common reasons for misclassification in the 405 patients who did not have an ECOPD included: lack of obstructive spirometry to diagnose COPD; and hospital admission due to progressive malignancy, asthma or cardiovascular disease. The broad search identified an additional 297 patients with ECOPD missed by the ECOPD codes. The vast majority of this group had pneumonia complicating ECOPD.ECOPD codes are insufficiently reliable to identify patients with clinically confirmed ECOPD for the purposes of audit or research. Search strategies should include pneumonia codes, specialist review of medical notes and spirometry confirmation of COPD.

Dry heat and microwave-generated steam protocols for the rapid decontamination of respiratory personal protective equipment in response to COVID-19-related shortages.

BACKGROUND: In the wake of the SARS-CoV-2 pandemic and unprecedented global demand, clinicians are struggling to source adequate access to personal protective equipment. Respirators can be in short supply, though are necessary to protect workers from SARS-CoV-2 exposure. Rapid decontamination and reuse of respirators may provide relief for the strained procurement situation. METHOD: In this study, we investigated the suitability of 70°C dry heat and microwave-generated steam (MGS) for reprocessing of FFP2/N95-type respirators, and Type-II surgical face masks. Staphylococcus aureus was used as a surrogate as it is less susceptible than enveloped viruses to chemical and physical processes. RESULTS: We observed >4 log10 reductions in the viability of dry S. aureus treated by dry heat for 90 min at 70°C and >6 log10 reductions by MGS for 90 s. After 3 reprocessing cycles, neither process was found to negatively impact the bacterial or NaCl filtration efficiency of the respirators that were tested. However, MGS was incompatible with Type-II surgical masks tested, as we confirmed that bacterial filtration capacity was completely lost following reprocessing. MGS was observed to be incompatible with some respirator types due to arcing observed around some types of metal nose clips and by loss of adhesion of clips to the mask. CONCLUSION: Considering the advantages and disadvantages of each approach, we propose a reprocessing personal protective equipment/face mask workflow for use in medical areas.

An in vitro study assessing the effect of mesh morphology and suture fixation on bacterial adherence.

PURPOSE: Prosthetic infections, although relatively uncommon in hernia surgery, are a source of considerable morbidity and cost. The aims of this experimental study were to assess the influence of the morphological properties of the mesh on bacterial adherence in vitro. The morphological properties assessed were the polymer type, filament type, filament diameter, mesh weight, mean pore size, and the addition of silver chlorhexidine and titanium coatings. In addition, the study assessed the effect on bacterial adherence of adding a commonly used suture to the mesh and compared adherence rates to self-gripping mesh that does not require suture fixation. METHODS: Eight commercially sourced flat hernia meshes with different material characteristics were included in the study. These were Prolene(®) (Ethicon(®)), DualMesh(®) (Gore(®)), DualMesh(®) Plus (Gore(®)), Parietex™ ProGrip (Covidien™), TiMesh(®) Light (GfE Medical), Bard(®) Soft Mesh (Bard(®)), Vypro(®) (Ethicon(®)), and Omyra(®) (Braun(®)). Individual meshes were inoculated with Staphylococcus epidermidis and Staphylococcus aureus with a bacterial inoculum of 10(2) bacteria. To assess the effect of suture material on bacterial adhesion, a sterile piece of commonly used monofilament suture material (2.0 Prolene(®), ZB370 Ethicon(®)) was sutured to selected meshes (chosen to represent different commonly used polymers and/or the presence of an antibacterial coating). Inoculated meshes were incubated for 18 h in tryptone soy broth and then analysed using scanning electron microscopy. A previously validated method for enumeration of bacteria using automated stage movement electron microscopy was used for direct bacterial counting. The final fraction of the bacteria adherent to the mesh was compared between the meshes and for each morphological variable. One-way analysis of variance (ANOVA) was performed on the bacterial counts. Tukey's test was used to determine the difference between the different biomaterials in the event the ANOVA was significant. RESULTS: Properties that significantly increased the mean bacterial adherence were the expanded polytetrafluoroethylene polymer (P < 0.001); multifilament meshes (P < 0.001); increased filament diameter (P < 0.001); increased mesh weight (P < 0.001); and smaller mean pore size (P < 0.001). In contrast, mesh coating with antibacterial silver chlorhexidine significantly reduced bacterial adhesion (S. epidermidis mean bacterial count 140.7 ± 19.1 SE with DualMesh(®) vs. 2.3 ± 1.2 SE with DualMesh(®) Plus, P < 0.001; S. aureus mean bacterial count 371.7 ± 22.7 SE with DualMesh(®) vs. 19.3 ± 4.7 SE with DualMesh(®) Plus, P = 0.002). The addition of 2.0 Prolene suture material significantly increased the mean number of adherent bacteria independent of the mesh polymer or mesh coating (P = 0.04 to <0.001). CONCLUSION: The present study demonstrates the significant influence of the prosthetic load on bacterial adherence. In patients at increased risk of infection, low prosthetic load materials, i.e., lightweight meshes with large pores, may be beneficial. Furthermore self-fixing meshes, which avoid increasing the prosthetic load and antibacterial impregnated meshes, may have an advantage in this setting.

Life after first-line chemotherapy in malignant pleural mesothelioma: a North-East England experience.

AIMS: The benefit of first-line chemotherapy in malignant pleural mesothelioma (MPM) has been established. However, this disease invariably progresses and little is known about how this disease subsequently relapses after initial treatment. Data on second-line treatment are also scarce, especially outside the context of a clinical trial. We conducted a review to observe the presentation of MPM patients when their disease progresses after initial therapy and the use of second-line therapy and its associated outcomes. MATERIALS AND METHODS: Patients were retrospectively identified from the Sunderland Royal Hospital and the Northern Centre for Cancer Care, Newcastle upon Tyne, UK. Data, including demographics, clinical presentation and treatment details at first line and beyond, together with its associated benefits, were collected. Related times to treatment failure (TTF), rates of symptom improvement and survival data were also collated. RESULTS: There were 62 evaluable patients in our series. At the time of data collection, 58 patients (94%) had relapsed. At disease progression, symptoms were usually similar to those at initial presentation, but in patients with prolonged TTF (>9 months) they were more likely to relapse with clinical lymphadenopathy in the neck and axilla compared with patients with TTF < or =9 months (52% vs 13%, respectively, P<0.05). Second-line treatment was given in 45% of patients. Twenty-one patients (36%) received second-line chemotherapy outside the context of a clinical trial and most had retreatment with pemetrexed-based chemotherapy due to a prolonged TTF. In patients treated with second-line therapy outside the remit of a clinical trial, a disease control rate was achieved in nine patients (43%, 95% confidence interval 22-64), whereas improvement in symptoms were noted in 13 patients (62%, 95% confidence interval 41-83). The median TTF in this setting was 6.5 months. CONCLUSION: Patients with a prolonged TTF after first-line treatment are more likely to relapse with neck and axillary lymphadenopathy. The use of second-line chemotherapy, including rechallenge treatment, in this disease is a viable option for a selected group of MPM patients.

Targets of glucocorticoid action on TNF-alpha release by macrophages.

Glucocorticoid drugs affect virtually every cell type involved in inflammatory response, to some degree. Macrophage/monocytes (Mphi) are particularly sensitive, and glucocorticoids suppress release of most known Mphi inflammatory mediators, including TNF-alpha. In the case of TNF-alpha, several levels of regulation are already characterised and ongoing research hints at further glucocorticoid targets. The relative importance of transcriptional and post-transcriptional regulation is lineage-dependent and may also change during the course of Mphi differentiation. In human monocytic cell lines, glucocorticoids primarily suppress transcriptional activation through adjacent promoter binding sites for NF-kappaB transcription factor complexes and for complexes of c-Jun with activating transcription factor-2 (ATF-2). The goal of glucocorticoid research in inflammation is to develop drugs with the anti-inflammatory potential of glucocorticoids, but without the systemic toxicity. Each of the multiple targets for glucocorticoid action presents an opportunity for anti-inflammatory drug development. However, none of the known targets is unique to Mphi, and no single pathway is preeminent in all situations. Research is now directed at characterising targets and regulating them without systemic activation of the glucocorticoid receptor.

NF-kappaB and cell-cycle regulation: the cyclin connection.

The cyclins are a family of proteins that are centrally involved in cell cycle regulation and which are structurally identified by conserved "cyclin box" regions. They are regulatory subunits of holoenzyme cyclin-dependent kinase (CDK) complexes controlling progression through cell cycle checkpoints by phosphorylating and inactivating target substrates. CDK activity is controlled by cyclin abundance and subcellular location and by the activity of two families of inhibitors, the cyclin-dependent kinase inhibitors (CKI). Many hormones and growth factors influence cell growth through signal transduction pathways that modify the activity of the cyclins. Dysregulated cyclin activity in transformed cells contributes to accelerated cell cycle progression and may arise because of dysregulated activity in pathways that control the abundance of a cyclin or because of loss-of-function mutations in inhibitory proteins.Analysis of transformed cells and cells undergoing mitogen-stimulated growth implicate proteins of the NF-kappaB family in cell cycle regulation, through actions on the CDK/CKI system. The mammalian members of this family are Rel-A (p65), NF-kappaB(1) (p50; p105), NF-kappaB(2) (p52; p100), c-Rel and Rel-B. These proteins are structurally identified by an amino-terminal region of about 300 amino acids, known as the Rel-homology domain. They exist in cytoplasmic complexes with inhibitory proteins of the IkappaB family, and translocate to the nucleus to act as transcription factors when activated. NF-kappaB pathway activation occurs during transformation induced by a number of classical oncogenes, including Bcr/Abl, Ras and Rac, and is necessary for full transforming potential. The avian viral oncogene, v-Rel is an NF-kappaB protein. The best explored link between NF-kappaB activation and cell cycle progression involves cyclin D(1), a cyclin which is expressed relatively early in the cell cycle and which is crucial to commitment to DNA synthesis. This review examines the interactions between NF-kappaB signaling and the CDK/CKI system in cell cycle progression in normal and transformed cells. The growth-promoting actions of NF-kappaB factors are accompanied, in some instances, by inhibition of cellular differentiation and by inhibition of programmed cell death, which involve related response pathways and which contribute to the overall increase in mass of undifferentiated tissue.

Glucocorticoids suppress tumor necrosis factor-alpha expression by human monocytic THP-1 cells by suppressing transactivation through adjacent NF-kappa B and c-Jun-activating transcription factor-2 binding sites in the promoter.

Glucocorticoid drugs suppress tumor necrosis factor-alpha (TNF-alpha) synthesis by activated monocyte/macrophages, contributing to an anti-inflammatory action in vivo. In lipopolysaccharide (LPS)-activated human monocytic THP-1 cells, glucocorticoids acted primarily on the TNF-alpha promoter to suppress a burst of transcriptional activity that occurred between 90 min and 3 h after LPS exposure. LPS increased nuclear c-Jun/ATF-2, NF-kappaB(1)/Rel-A, and Rel-A/C-Rel transcription factor complexes, which bound specifically to oligonucleotide sequences from the -106 to -88 base pair (bp) region of the promoter. The glucocorticoid, dexamethasone, suppressed nuclear binding activity of these complexes prior to and during the critical phase of TNF-alpha transcription. Site-directed mutagenesis in TNF-alpha promoter-luciferase reporter constructs showed that the adjacent c-Jun/ATF-2 (-106 to -99 bp) and NF-kappaB (-97 to -88 bp) binding sites each contributed to the LPS-stimulated expression. Mutating both sites largely prevented dexamethasone from suppressing TNF-alpha promoter-luciferase reporters. LPS exposure also increased nuclear Egr-1 and PU.1 abundance. The Egr-1/Sp1 (-172 to -161 bp) binding sites and the PU.1-binding Ets site (-116 to -110 bp) each contributed to the LPS-stimulated expression but not to glucocorticoid response. Dexamethasone suppressed the abundance of the c-Fos/c-Jun complex in THP-1 cell nuclei, but there was no direct evidence for c-Fos/c-Jun transactivation through sites in the -172 to -52 bp region. Small contributions to glucocorticoid response were attributable to promoter sequences outside the -172 to -88 bp region and to sequences in the TNF-alpha 3'-untranslated region. We conclude that glucocorticoids suppress LPS-stimulated secretion of TNF-alpha from human monocytic cells largely through antagonizing transactivation by c-Jun/ATF-2 and NF-kappaB complexes at binding sites in the -106 to -88 bp region of the TNF-alpha promoter.

Effects of stimulus and cell type on the expression of the -308 tumour necrosis factor promoter polymorphism.

The authors have previously demonstrated that the tumour necrosis factor (TNF) -308 G/A polymorphism affects the binding of transcription factors. In transient transfection assays in PMA stimulated U937 monocytes and Jurkat T cells, the A-containing TNF2 promoter has a 2-3-fold greater transcriptional activity than the TNF1 promoter in the presence of the TNF 3'UTR. In this study it was found that a difference in TNF1 and TNF2 promoter activities was only observed in U937 and Jurkat cells, and not in Raji (B cell line), HeLa (epithelial carcinoma cell line), HepG2 (hepatoma cell line) or THP-1 (monocyte), suggesting cell-type specific transcription factors or modifications may be involved in the formation of the -308 protein/DNA complex. Physiological stimulators, TNF and interferon gamma (IFN-gamma) did not cause differential promoter activity between TNF1 and TNF2, but LPS did with only the TNF2 promoter/3'UTR construct being significantly responsive to lipopolysaccharide (LPS) in U937 cells. In U937 cells, the -308 polymorphism affected transcription following differentiation by phorbol myristate acetate (PMA), retinoic acid, PMA plus LPS and PMA plus retinoic acid with an increase in nuclear factor binding to both TNF1 and TNF2 in the -323 to -285 region being observed. The greatest difference between TNF2 and TNF1 promoter activities (5-fold) was observed following PMA plus retinoic acid treatment of transfected U937 cells for 48h. During this time, U937 differentiated into cells with a macrophage-like morphology. An understanding of the cell type and stimuli specific requirements for differential expression of the -308 polymorphism may help elucidate the role the TNF -308 polymorphism plays in diseases where elevated TNF levels are thought to be important.

Integration of Rac-dependent regulation of cyclin D1 transcription through a nuclear factor-kappaB-dependent pathway.

The small GTP-binding protein Rac1, a member of the Ras superfamily, plays a fundamental role in cytoskeleton reorganization, cellular transformation, the induction of DNA synthesis, and superoxide production. Cyclin D1 abundance is rate-limiting in normal G(1) phase progression, and the abundance of cyclin D1 is induced by activating mutations of both Ras and Rac1. Nuclear factor-kappaB (NF-kappaB) proteins consist of cytoplasmic hetero- or homodimeric Rel-related proteins complexed to a member of the IkappaB family of inhibitor proteins. In the current studies, activating mutants of Rac1 (Rac(Leu-61), Rac(Val-12)) induced cyclin D1 expression and the cyclin D1 promoter in NIH 3T3 cells. Induction of cyclin D1 by Rac1 required both an NF-kappaB and an ATF-2 binding site. Inhibiting NF-kappaB by overexpression of an NF-kappaB trans-dominant inhibitor (nonphosphorylatable IkappaBalpha) reduced cyclin D1 promoter activation by the Rac1 mutants, placing NF-kappaB in a pathway of Rac1 activation of cyclin D1. Specific amino acid mutations in the amino-terminal effector domain of Rac(Leu-61) had comparable effects on NF-kappaB transcriptional activity and activation of the cyclin D1 promoter. The NF-kappaB factors Rel A (p65) and NF-kappaB(1) (p50) induced the cyclin D1 promoter, requiring both the NF-kappaB binding site and the ATF-2 site. Stable overexpression of Rac(Leu-61) increased binding of Rel A and NF-kappaB(1) to the cyclin D1 promoter NF-kappaB site. Activation of Rac1 in NIH 3T3 cells induces both NF-kappaB binding and activity and enhances expression of cyclin D1 through an NF-kappaB and ATF-2 site in the proximal promoter, suggesting a critical role for NF-kappaB in cell cycle regulation through cyclin D1 and Rac1.

Effect of teicoplanin on isolation of Staphylococcus aureus from blood culture media.

Intraoperative bacteraemia has been used as an indicator of the efficacy of prophylactic antibiotics. Two clinical isolates of Staphylococcus aureus in nutrient broth, with or without human serum, were exposed to teicoplanin (50 mg/L) and, either immediately or after 30 min, inoculated into blood culture bottles. Bottles with and without resin were used and the experiment was repeated five times with one strain. In the absence of teicoplanin, an inoculum of 10 cfu/mL produced growth in both resin and non-resin bottles. In the presence of teicoplanin, an inoculum of at least 10(5) cfu/mL was required in non-resin bottles to obtain growth, but this was reduced to 10(2)-10(3) cfu/mL for resin bottles. Intraoperative blood cultures overestimate the efficacy of bacterial killing by prophylactic antibiotics during surgery.

The modulation of cellular responses to poly(2-hydroxyethyl methacrylate) hydrogel surfaces: phosphorylation decreases macrophage collagenase production in vitro.

We examined the regulation of collagenase production by the monocyte/macrophage THP-1 cell line when these cells were exposed to poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel surfaces with different chemistries and morphologies. Tissue culture modified polystyrene (TCP), used as a control surface, induced the maximum collagenase response. Copolymer hydrogels containing 2-ethoxyethyl methacrylate (EMA) or methyl methacrylate (MMA) also induced a high response, while PHEMA hydrogels induced a low level response and the phosphorylated hydrogel induced no response. This pattern was altered when the morphology of the hydrogels was changed to that of a sponge. The overall enzyme response to the sponge hydrogels was lower than that to the homogeneous hydrogels. Sponges containing EMA and MMA produced low level response relative to the TCP control. PHEMA and phosphorylated sponges produced little and no response respectively. The dramatically reduced enzyme response to phosphorylated surfaces was not a consequence of cell death, and may be a phenomenon related to changes in cell surface charge.

Altered leucocyte trafficking and suppressed tumour necrosis factor alpha release from peripheral blood monocytes after intra-articular glucocorticoid treatment.

OBJECTIVES: A generalised transient improvement may follow intra-articular administration of glucocorticoids to patients with inflammatory arthropathy. This may represent a systemic anti-inflammatory effect of glucocorticoid released from the joint, mediated through processes such as altered leucocyte trafficking or suppressed release of pro-inflammatory cytokines. Patients, who had received intra-articular injections of glucocorticoids were therefore studied for evidence of these two systemic effects. METHODS: Patients with rheumatoid arthritis were studied. Peripheral blood leucocyte counts, tumour necrosis factor alpha (TNF alpha) release by peripheral blood monocytes, blood cortisol concentrations, and blood methylprednisolone concentration were measured for 96 hours after intra-articular injection of methylprednisolone acetate. RESULTS: Measurable concentrations of methylprednisolone were present in blood for up to 96 hours after injection. Significant suppression of the hypothalamic-pituitary-adrenal axis persisted throughout this time. Altered monocyte and lymphocyte trafficking, as evidenced by peripheral blood monocytopenia and lymphopenia, was apparent by four hours after injection and resolved in concordance with the elimination of methylprednisolone. Granulocytosis was observed at 24 and 48 hours. Release of TNF alpha by endotoxin stimulated peripheral blood monocytes was suppressed at four hours and thereafter. Suppression was maximal at eight hours and was largely reversed by the glucocorticoid antagonist, mifepristone. CONCLUSIONS: After intra-articular injection of methylprednisolone, blood concentrations of glucocorticoid are sufficient to suppress monocyte TNF alpha release for at least four days and to transiently alter leucocyte trafficking. These effects help to explain the transient systemic response to intra-articular glucocorticoids. Suppression of TNF alpha is principally a direct glucocorticoid effect, rather than a consequence of other methylprednisolone induced changes to blood composition.

Dexamethasone suppresses release of soluble TNF receptors by human monocytes concurrently with TNF-alpha suppression.

Glucocorticoids suppress many monocyte functions, including endotoxin-stimulated release of TNF-alpha. Monocytes also release soluble receptors for TNF (sTNF-R), which can modulate TNF bioactivity. We therefore examined the effects of the glucocorticoid, dexamethasone, on the release of soluble forms of the 55 kDa and 75 kDa receptors for TNF (sTNF-R55 and sTNF-R75) by human monocytes and the human monocytic Mono Mac 6 cell line. Peripheral blood mononuclear cells (PBMC) spontaneously released 406 +/- 181 pg/10(6) cells of sTNF-R75 over 18 h in culture and Mono Mac 6 cells released 554 +/- 29 pg/10(6) cells. Lipopolysaccharide (LPS) exposure increased release of sTNF-R75 by 54 and 217%, respectively. Dexamethasone suppressed both spontaneous and LPS-stimulated release. The effect of dexamethasone was concentration dependent. At 1 mumol/L, dexamethasone suppressed the LPS-stimulated release of sTNF-R75 by 86% in PBMC and by 40% in Mono Mac 6 cells. Neither PBMC nor Mono Mac 6 cells released measurable amounts of sTNF-R55, but spontaneous release of sTNF-R55 from purified human monocytes (55 +/- 2 pg/10(6) cells over 18 h) was reduced by 45% in the presence of dexamethasone. Dexamethasone reduced bioactive TNF in PBMC cultures, as well as immunoassayable TNF-alpha, which indicates that suppression of TNF-alpha release was biologically more important than suppressed release of soluble inhibitors. Similar concurrent suppression of IL-1 beta and IL-1ra release occurred in PBMC and Mono Mac 6 cultures exposed to dexamethasone.

Plasma concentrations of tumour necrosis factor-alpha and interleukin-6 during burn wound surgery or dressing.

BACKGROUND: Clinical deterioration after burn wound manipulation may be related to the release of cytokines including tumour necrosis factor-alpha (TNF) and interleukin-6 (IL-6). METHODS: The two cytokines were assayed by immunoenzymetric assay in blood samples taken before and during manipulation of the burn wound. An antibiotic, teicoplanin, was administered to half the patients at the start of the procedure in a randomized fashion as part of a separate trial. FINDINGS: Sixty patients with a median burn size of 8% (range 1-56%) were studied during dressing change (n = 40) or burn excision (n = 20). There was little change in TNF levels between preoperative and recovery samples but IL-6 concentrations increased three-fold, particularly in those with large recent burns or bacteraemia, and were correlated with poor clinical outcome. The presence of teicoplanin did not significantly affect the levels of either cytokine. INTERPRETATION: The systemic cytokine response to burn wound dressing or debridement is predominantly that of IL-6 and it is not significantly reduced by preventing Gram-positive bacteraemia during the procedure.

Randomized placebo-controlled trial of teicoplanin in the antibiotic prophylaxis of infection following manipulation of burn wounds.

BACKGROUND: Burn wound surgery or change of dressings commonly causes bacteraemia. The use of antibiotic prophylaxis has not been tested adequately in a controlled trial. METHODS: A randomized double-blind placebo-controlled study was performed to determine the effect on Gram-positive bacteraemia and clinical outcome of a single dose of teicoplanin (12 mg/kg intravenously) given at burns surgery or change of dressings. RESULTS: A total of 134 patients were entered into the study, representing 220 episodes of dressing or debridement (110 episodes in each group). There was a significant difference between the groups with respect to perioperative Gram-positive bacteraemia: eight episodes (7 per cent) in the teicoplanin group versus 51 (46 per cent) in the placebo group (P < 0.001). However, good clinical outcome was similar in both groups (80 of 110 versus 77 of 110 respectively, P = 0.7). Only eleven patients had bacteraemia caused by Gram-negative species alone. Bacteriological response in terms of wound culture showed no significant difference between the groups: 63 (57 per cent) of 110 episodes versus 58 (53 per cent) of 110 respectively respectively. CONCLUSION: Prevention of Gram-positive bacteraemia did not affect postoperative recovery.

Suppression of human monocyte tumour necrosis factor-alpha release by glucocorticoid therapy: relationship to systemic monocytopaenia and cortisol suppression.

AIMS: Glucocorticoids suppress the release of tumour necrosis factor-alpha (TNF-alpha) by macrophages in vitro and cause monocytopaenia in vivo. These actions may contribute to anti-inflammatory and immunosuppressant effects. We therefore examined relationships between prednisolone concentration, suppression of monocyte TNF-alpha release, monocytopaenia and suppression of total cortisol concentration in healthy volunteers treated with a single dose (1.5 mg kg-1) of the glucocorticoid, prednisolone. METHODS: Monocyte numbers, total cortisol concentration and prednisolone concentration were measured in blood samples collected over 48 h after the dose. Plasma from these samples was also tested for its capacity to suppress lipopolysaccharide-induced TNF-alpha release from monocytes in autologous whole blood cultures. RESULTS: At 4 h after the dose, monocyte numbers in peripheral blood had fallen to a mean of 18% of the pre-dose level whilst plasma total cortisol had fallen to 9% of the pre-dose concentration. Monocyte numbers recovered in concordance with elimination of prednisolone and there was a significant relative monocytosis at 24 h. The recovery of plasma cortisol was delayed in comparison, with cortisol remaining significantly suppressed at 24 h. Plasma samples taken at 2 h after the dose (corresponding to peak plasma prednisolone concentration) suppressed the lipopolysaccharide-stimulated production of TNF-alpha by autologous blood monocytes to 27% of pre-dose control. Plasma collected at intervals over the 48 h from dosing also suppressed monocyte TNF-alpha release in relation to the prednisolone concentration therein. Suppression was largely reversed by the glucocorticoid antagonist, mifepristone. A similar relationship between prednisolone concentration and TNF-alpha suppression was observed when prednisolone was added to blood samples collected from the volunteers when they were drug-free. CONCLUSIONS: Blood concentration of prednisolone achieved after a dose of 1.5 mg kg-1 are sufficient to suppress monocyte TNF-alpha release and cause a biphasic change in peripheral blood monocyte numbers. Suppression of TNF-alpha is principally a direct glucocorticoid effect, rather than a consequence of other prednisolone-induced changes to blood composition.

Glucocorticoid modulation of human monocyte/macrophage function: control of TNF-alpha secretion.

Glucocorticoids suppress many functions in activated monocyte/macrophages, including the release of TNF-alpha. This is likely to contribute to the efficacy of glucocorticoids in some inflammatory diseases, such as rheumatoid arthritis, where TNF-alpha contributes to pathogenesis. Glucocorticoids suppress the activity of reporters which include TNF-alpha promoter regions and modify the activity of NF-kappa B family transcription factors in activated human monocytic cell lines, suggesting effects of glucocorticoids on TNF-alpha gene transcription. In addition, glucocorticoids have been reported to antagonise the enhanced translational efficiency of TNF-alpha mRNA which occurs at least after stimulation of murine monocytic cells. It is likely, therefore, that glucocorticoids act at several points in stimulated monocyte/ macrophages to reduce TNF-alpha secretion. Understanding glucocorticoid control of TNF-alpha secretion may explain some of the variability in response to GC in inflammatory diseases and may reveal means of inducing glucocorticoid-like anti-inflammatory effects in monocyte/macrophages without exposing other tissues to the adverse effects of glucocorticoids.

Dexamethasone antagonizes IL-4 and IL-10-induced release of IL-1RA by monocytes but augments IL-4-, IL-10-, and TGF-beta-induced suppression of TNF-alpha release.

The activities of monocyte-derived tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta are potentially modified by IL-1RA and soluble receptors for TNF (sTNF-R), which are themselves monocyte products. IL-4, IL-10, TGF-beta, and glucocorticoids (GC) all suppress the lipopolysaccharide (LPS)-stimulated release of TNF-alpha and IL-1beta but vary in their effects on IL-1RA and sTNF-R. This raises the prospect of interactions between the cytokines and glucocorticoids, which may be antagonistic or additive on IL-1 and TNF activity. We, therefore, studied the interactions of the GC dexamethasone (Dex) with IL-4, IL-10, and transforming growth factor (TGF)-beta on the release of TNF-alpha and IL-1RA by human monocytes and the monocytic THP-1 cell line. Low concentration of Dex (10(-8)-10(-7)M) acted additively with low concentrations of IL-4 (0.01-1 ng/ml), IL-10 (0.01-0.1 U/ml), or TGF-beta (0.01-1 ng/ml) to profoundly suppress LPS-stimulated release of TNF-alpha by whole blood and, to a lesser degree, THP-1 cells. Dex also suppressed spontaneous release of IL-1RA from PBMC and THP-1 cells, whereas IL-4 and IL-10, but not TGF-beta, stimulated release. Dex antagonized the enhanced release in IL-4 and IL-10-stimulated cultures. The capacity to stimulate release of IL-1RA may contribute to the anti-inflammatory potential of IL-4 and IL-10 in monocyte/macrophage-mediated disease. GC, therefore, do not uniquely enhance the suppressive functions of IL-4 and IL-10 on monokine activity. The therapeutic benefit of combinations of GC and IL-4, IL-10 or TGF-beta in disease may depend on the roles of the individual monokines and antagonists in pathogenesis.

Quantitative microbiology in the management of burn patients. I. Correlation between quantitative and qualitative burn wound biopsy culture and surface alginate swab culture.

The diagnosis and treatment of burn wound infection is commonly determined by clinical impression and the qualitative results of surface swabs. It has been suggested that quantitative bacteriology from burn wound biopsies confirms burn wound infection and improves patient management. Methods for quantitating surface flora have been described, but comparisons with biopsy specimens have been contradictory. The quantitative and qualitative results of 141 pairs of biopsies and surface swabs, from 74 burn patients, were compared. Staph. aureus was the commonest organism isolated (29 per cent of biopsies and 35 per cent of swabs). Recovery of the same set of species from biopsy and swab occurred in 54 per cent of pairs. There was a significant correlation between the bacterial count obtained by biopsy and by surface swab (P < 0.001), but using various threshold values, the predictive value of the counts obtained by one method to predict the counts obtained by the other was poor. Parallel cultures taken on 18 occasions, showed a significant correlation between bacterial counts obtained from two biopsies or two swabs taken simultaneously (P < 0.002), but there was wide variation in bacterial densities from the same burn wound at the same time. Recovery of the same set of species from both biopsies occurred in 56 per cent of pairs, and from both swabs in 50 per cent of pairs. The use of quantitative microbiology in burns is limited by the unreliability of a single surface swab or biopsy to represent the whole burn wound.

Quantitative microbiology in the management of burn patients. II. Relationship between bacterial counts obtained by burn wound biopsy culture and surface alginate swab culture, with clinical outcome following burn surgery and change of dressings.

The use of quantitative bacteriology in the burns unit has been thought to be efficient in predicting sepsis or graft loss. To examine the relationship between clinical outcome and bacterial densities on and in the burn wound, 69 biopsy/surface swab pairs were collected from 47 patients on 64 occasions, either immediately prior to excision and grafting, or at routine change of dressings. The mean per cent TBSA burn was 16 (range 1-65). There was a significant correlation between log total bacterial count by biopsy with total white cell count and age (P = 0.028), and a significant negative correlation between total bacterial count by swab with per cent TBSA (P = 0.006). There was no significant difference in bacterial counts between patients judged to be a clinical success or clinical failure (72 h follow-up), either after undergoing excision and grafting, or change of dressings, and no difference in counts between patients with perioperative bacteraemia and those without. With burns > 15 per cent TBSA, a relationship between bacterial counts and subsequent sepsis or graft loss still was not demonstrated. It is suggested that quantitative bacteriology by burn wound biopsy or surface swab does not aid the prediction of sepsis or graft loss.