Abstract: The cholinergic nervous system can inhibit the release of proinflammatory cytokines such as TNF-alpha from LPS-stimulated macrophages. Acetylcholine, the principal neurotransmitter of the vagus nerve, is the key mediator of this so-called cholinergic anti-inflammatory pathway, specifically interacting with alpha7 cholinergic receptors expressed by macrophages and other cell types to inhibit TNF-alpha production. The aim of the current study was to determine the capacity of the selective alpha7 cholinergic receptor agonist 3-(2,4-dimethoxybenzylidene) anabaseine (GTS-21), administered locally into the airways, to inhibit LPS-induced inflammatory responses in the mouse lung in vivo. GTS-21 dose-dependently inhibited LPS-induced TNF-alpha release by MH-S mouse alveolar macrophages in vitro. Intranasal inoculation with GTS-21 also dose-dependently inhibited TNF-alpha release into the lung compartment after intrapulmonary delivery of LPS in mice in vivo, whereas IL-6 concentrations were not affected. However, GTS-21 did not influence the influx of neutrophils into bronchoalveolar lavage fluid elicited by LPS and increased the concentrations of the neutrophil-attracting chemokines cytokine-induced neutrophil chemoattractant and macrophage inflammatory protein 2. These data indicate that local administration of GTS-21 inhibits TNF-alpha release in the lung during LPS-induced inflammation.
Abstract: The cholinergic nervous system controls inflammation by inhibiting the release of proinflammatory cytokines such as tumor necrosis factor (TNF) alpha from lipopolysaccharide (LPS)-stimulated macrophages. The key endogenous mediator of this so-called cholinergic anti-inflammatory pathway is acetylcholine, the principal neurotransmitter of the vagus nerve, which specifically interacts with alpha7 cholinergic receptors expressed by macrophages and other cell types to inhibit TNF-alpha production. We here investigated the capacity of the selective alpha7 cholinergic receptor agonist 3-(2,4-dimethoxybenzylidene) anabaseine (GTS-21) to inhibit LPS-induced inflammatory responses in mice in vivo. To this end, mice received an intraperitoneal injection of LPS (from Escherichia coli, 200 microg) preceded by GTS-21 (4 mg/kg) or vehicle. GTS-21 strongly inhibited LPS-induced TNF-alpha release into the peritoneal cavity and the circulation. In addition, GTS-21 attenuated the influx of neutrophils into peritoneal fluid upon administration of LPS. This inhibitory effect on neutrophil recruitment by GTS-21 was independent of its effect on TNF-alpha release, considering that etanercept, a potent TNF-alpha-blocking protein containing the extracellular domain of the p75 TNF-alpha receptor, did not influence LPS-induced neutrophil influx either in the presence or in the absence of GTS-21 treatment. GTS-21 did not reduce the local secretion of macrophage inflammatory protein 2 and keratinocyte-derived cytokine, suggesting that altered concentrations of these neutrophil-attracting chemokines did not contribute to GTS-21-induced inhibition of neutrophil migration. These data identify a novel anti-inflammatory effect of chemical alpha7 cholinergic receptor stimulation that is independent from its capacity to inhibit TNF-alpha production.
Abstract: BACKGROUND & AIMS: The nervous system, through the vagus nerve, controls inflammation by decreasing the release of tumor necrosis factor-alpha from endotoxin stimulated macrophages. This anti-inflammatory effect is mediated by an interaction of acetylcholine, the principal neurotransmitter of the vagus nerve, with macrophage cholinergic nicotinic receptors expressing the alpha7 subunit. METHODS: To determine the role of this "nicotinic anti-inflammatory pathway" in experimental pancreatitis, we induced pancreatitis in mice by 12 hourly intraperitoneal injections of cerulein. Pancreatitis was preceded by unilateral left cervical vagotomy or pretreatment with the nicotinic receptor antagonist mecamylamine or by pretreatment with the selective alpha7 nicotinic receptor agonist 3-(2,4-dimethoxybenzylidene) anabaseine (GTS-21). RESULTS: Vagotomy or pretreatment with mecamylamine resulted in an enhanced severity of pancreatitis, as reflected by histology, edema, plasma hydrolases, and interleukin-6 levels. Furthermore, the number of neutrophils migrated to the pancreas was increased in these mice, as shown by myeloperoxidase content and intrapancreatic staining of neutrophils. Conversely, GTS-21 pretreatment strongly decreased the severity of pancreatitis. Pancreatitis-associated pulmonary inflammation was independent of the integrity of the vagus nerve and nicotinic receptors. CONCLUSIONS: This study provides the first evidence for a therapeutic potential of the vagus nerve and the "nicotinic anti-inflammatory pathway" in attenuating inflammation and injury during experimental pancreatitis.
Abstract: A 34-year-old bodybuilder presented at the emergency room with fever, vomiting and muscle cramps that had started during a bodybuilding session. Several days before he started training he had used tablets and intramuscular injections containing the anabolic steroids: dehydro-chloro-methyltestosterone, boldenone and trenbolone. In addition, he had taken clenbuterol tablets, liothyronine tablets and subcutaneous injections of phosphatidylcholine. Laboratory investigations revealed massive rhabdomyolysis. The patient was treated with intravenous fluid replacement and sodium bicarbonate to alkalinize the urine. He recovered quickly and his renal function remained unaffected. 'Doping' among amateur athletes in the Netherlands occurs frequently. Apart from long term side-effects, doping can also cause acute health problems. Therefore it is important to ask about doping use during history taking in amateur athletes.
Abstract: BACKGROUND: Sepsis and endotoxemia are associated with concurrent activation of inflammation and the hemostatic mechanism, which both contribute to organ dysfunction and death. Electrical vagus nerve stimulation (VNS) has been found to inhibit tumor necrosis factor (TNF)-alpha release during endotoxemia in rodents. OBJECTIVE: To determine the effect of VNS on activation of coagulation and fibrinolysis. METHODS: Rats received a sublethal i.v. dose of lipopolysaccharide (LPS) after electrical VNS or sham stimulation. Activation of coagulation and fibrinolysis, as well as cytokine release, was measured before LPS injection and 2, 4 and 6 h thereafter. Results: LPS induced activation of the coagulation system (increases in the plasma concentrations of thrombin-antithrombin complexes and D-dimer, and a decrease in antithrombin) and biphasic changes in the fibrinolytic system [early rises of plasminogen activator activity and tissue-type plasminogen activator, followed by a delayed increase in plasminogen activator inhibitor type 1 (PAI-1)]. VNS strongly inhibited all LPS-induced procoagulant responses and more modestly attenuated the fibrinolytic response. In addition, VNS attenuated the LPS-induced increases in plasma and splenic concentrations of the proinflammatory cytokines TNF-alpha and interleukin-6 (IL-6), while not influencing the release of the anti-inflammatory cytokine IL-10. CONCLUSION: These data illustrate a thus far unrecognized effect of VNS and suggest that the cholinergic anti-inflammatory pathway not only impacts on inflammation but also on the coagulant-anticoagulant balance.
Abstract: Peroxisome proliferator-activated receptor (PPAR)-gamma controls growth, differentiation, and inflammation. PPAR-gamma agonists exert anti-inflammatory effects in vitro and inhibit the activation of pancreas stellate cells, implicated in the formation and progression of fibrosis. We determined the influence of troglitazone, a ligand for PPAR-gamma, on pancreatic damage and fibrosis in experimental chronic pancreatitis. Mice received six hourly intraperitoneal injections with 50 microg/kg of cerulein or saline, three times a week for 6 weeks. One week after the last injection all mice were sacrificed. Untreated mice were compared with mice treated with troglitazone either during weeks 1 to 6 or weeks 4 to 6. All mice that received cerulein injections displayed histopathological signs of chronic pancreatitis at week 7. Troglitazone treatment improved all markers for severity of pancreatitis. Moreover, early and postponed troglitazone treatments were equally effective in diminishing intrapancreatic fibrosis as quantified by Sirius red staining, hydroxyproline content, and laminin staining as well as the increased number of pancreatic stellate cells and pancreas levels of transforming growth factor-beta. Thus, troglitazone attenuated pancreatic damage and inflammation in experimental chronic pancreatitis and remained beneficial in a therapeutic setting when given after initial damage had been established.
Abstract: OBJECTIVE: Acute pancreatitis is frequently complicated by Gram-negative sepsis. Mammalian cells recognize lipopolysaccharide from Gram-negative bacteria via Toll-like receptor (TLR) 4. The objective of this study was to determine the role of TLR4 in the defense against Gram-negative sepsis in previously healthy mice and in animals with preexisting pancreatitis. DESIGN: A controlled, in vivo laboratory study. SETTING: Research laboratory of a health sciences university. SUBJECTS: Female C3H/HeJ (nonfunctional TLR4 mutant) and C3H/HeN (wild-type) mice. INTERVENTIONS: Abdominal sepsis was induced by the intraperitoneal injection of Escherichia coli. Pancreatitis was induced by 12 hourly intraperitoneal injections of cerulein. MEASUREMENTS AND MAIN RESULTS: The following experiments were performed. First, healthy TLR4 mutant mice demonstrated an enhanced bacterial load and dissemination of the infection relative to wild-type mice after intraperitoneal injection with E. coli, associated with a reduced early release of proinflammatory cytokines and an attenuated influx of neutrophils into the peritoneal fluid. Second, wild-type mice in which acute pancreatitis was induced by repeated cerulein injections showed an increased bacterial load and dissemination of E. coli relative to wild-type mice without pancreatitis, which was accompanied by a blunted proinflammatory cytokine response by peritoneal macrophages ex vivo and a diminished early cytokine and neutrophil response in vivo. Third, whereas the severity of cerulein-induced pancreatitis was similar in TLR4 mutant and wild-type mice, the important contribution of TLR4 to an effective host defense against E. coli sepsis observed in previously healthy mice was no longer present in mice with preexisting pancreatitis. CONCLUSIONS: These data suggest that TLR4 deficiency and acute pancreatitis act similarly in reducing host defense against E. coli peritonitis and that the role of TLR4 in severe Gram-negative infection depends, at least in part, on the presence of preexisting critical illness.
Abstract: OBJECTIVE: Nosocomial pneumonia is a feared complication in the critically ill patient. Aspiration pneumonitis is frequently complicated by infections. The objective of this study was to determine the influence of aspiration pneumonitis on the host response to a common nosocomial respiratory pathogen. DESIGN: Controlled, in vivo laboratory study. SETTING: Research laboratory of a health sciences university. SUBJECTS: Female C57Bl/6 mice. INTERVENTIONS: Mice received hydrochloric acid or saline intratracheally followed 16 hrs later by Klebsiella pneumoniae. MEASUREMENTS AND MAIN RESULTS: Hydrochloric acid induced a mild aspiration pneumonitis. Nonetheless, hydrochloric acid aspiration resulted in a markedly increased inflammatory response in the lung on infection with K. pneumoniae. This enhanced inflammatory reaction was accompanied by a greatly increased outgrowth of K. pneumoniae in lungs of mice previously exposed to hydrochloric acid. Preexisting aspiration pneumonitis also triggered mouse lungs in vivo and alveolar macrophages ex vivo for enhanced release of proinflammatory mediators on stimulation with Klebsiella lipopolysaccharide. Inhibition of tumor necrosis factor-alpha resulted in an increased inflammatory reaction and enhanced bacterial outgrowth in mice with primary K. pneumoniae pneumonia, whereas it had no effect in mice with preexisting aspiration pneumonitis. CONCLUSIONS: These data indicate a) that aspiration pneumonitis renders the host more susceptible to respiratory tract infection with K. pneumoniae, concurrently priming the lung for an exaggerated inflammatory response; and b) that although tumor necrosis factor-alpha plays a major role in the host response to primary infection, it does not affect lung inflammation or defense after aspiration pneumonitis.
Abstract: Acetylcholine released by efferent vagus nerves inhibits macrophage activation. Here we show that the anti-inflammatory action of nicotinic receptor activation in peritoneal macrophages was associated with activation of the transcription factor STAT3. STAT3 was phosphorylated by the tyrosine kinase Jak2 that was recruited to the alpha7 subunit of the nicotinic acetylcholine receptor. The anti-inflammatory effect of nicotine required the ability of phosphorylated STAT3 to bind and transactivate its DNA response elements. In a mouse model of intestinal manipulation, stimulation of the vagus nerve ameliorated surgery-induced inflammation and postoperative ileus by activating STAT3 in intestinal macrophages. We conclude that the vagal anti-inflammatory pathway acts by alpha7 subunit-mediated Jak2-STAT3 activation.
Abstract: BACKGROUND: The nervous system, through the vagus nerve, can down-regulate inflammation in vivo by decreasing the release of tumor necrosis factor- alpha by endotoxin-stimulated macrophages. This anti-inflammatory effect is mediated by an interaction between acetylcholine, the principal neurotransmitter of the vagus nerve, and cholinergic nicotinic acetylcholine receptors on macrophages. METHODS: We determined the role of this "cholinergic anti-inflammatory pathway" during septic peritonitis induced in mice by intraperitoneal injection of live Escherichia coli. Septic peritonitis was preceded by inhibition of the cholinergic anti-inflammatory pathway by unilateral cervical vagotomy, by stimulation of this pathway by pretreatment of mice with nicotine, or by a combination of both interventions. RESULTS: Initial cytokine release during septic peritonitis was enhanced after previous vagotomy and was decreased after nicotine pretreatment, independently of the integrity of the vagus nerve. Further study established that vagotomy before septic peritonitis resulted in an enhanced influx of neutrophils and a marked increase in proinflammatory cytokine levels and liver damage. Conversely, nicotine pretreatment strongly decreased cell influx, proinflammatory cytokine levels, and liver damage, whereas bacterial clearance and survival were impaired. DISCUSSION: These data provide the first evidence, to our knowledge, of an important role of the vagus nerve in regulating the innate immune response to a severe bacterial infection.
Abstract: BACKGROUND AND STUDY AIMS: In selected patients with chronic pancreatitis in whom conventional plastic stenting fails and in whom surgery is contraindicated or declined, insertion of a biliary self-expanding metal stent (SEMS) may be a valuable treatment option. PATIENTS AND METHODS: Between 1994 and 1999, 13 patients with chronic pancreatitis received SEMS for benign biliary strictures (four women and nine men; mean age 56). The indications for SEMS placement were: contraindication to surgery (n = 10), presumed inoperable pancreatic carcinoma (n = 1), concomitant unresectable lung cancer (n = 1), and declined surgery (n = 1). The success of treatment was defined as adequate biliary drainage due to SEMS therapy. RESULTS: The mean follow-up period was 50 months (range 6 days - 86 months). Nine patients (69 %) were successfully treated with SEMS therapy: a patent first SEMS (n = 5); a patent second SEMS inserted through the first SEMS (n = 3); and one patent SEMS after balloon cleaning. SEMS treatment was not successful in four patients (due to stent migration in one case and occlusion in three ). The mean patency period of the SEMS was 60 months (95 % CI, 43 months - 77 months). At 33 months, the probability of adequate biliary drainage with SEMS therapy was 75 %. CONCLUSIONS: SEMS therapy was safe and provided successful and prolonged biliary drainage in a selected group of patients with benign biliary strictures due to chronic pancreatitis in whom surgical intervention was not possible or desirable.
Abstract: OBJECTIVE: Nosocomial pneumonia is a feared complication in the critically ill patient. Serious acute pancreatitis is frequently complicated by infections. The objectives of this study were to determine the influence of acute pancreatitis on host defense against Pseudomonas pneumonia and to determine the influence of Pseudomonas pneumonia on the severity of concurrent pancreatitis. DESIGN: A controlled, in vivo laboratory study. SETTING: Research laboratory of a health sciences university. SUBJECTS: Female C57Bl/6 mice. INTERVENTIONS: Pancreatitis was induced by 12 hourly intraperitoneal injections of cerulein (pancreatitis) or saline (sham) immediately followed by intranasal administration of Pseudomonas aeruginosa (to induce pneumonia) or saline (controls). Mice were killed 24 hrs later. Hence, four groups were studied: sham/control, pancreatitis/control, sham/pneumonia, and pancreatitis/pneumonia mice. MEASUREMENTS AND MAIN RESULTS: When compared with sham/pneumonia mice, pancreatitis/pneumonia mice demonstrated exaggerated lung inflammation, higher bacterial counts in lungs and pancreas, and enhanced dissemination of the infection. Concurrently, pneumonia prolonged the course of pancreatitis, as reflected by histopathology and higher plasma amylase and relative pancreas weights (all p < .05 for the difference between pancreatitis/pneumonia and pancreatitis/control mice), which was associated with the localization of Pseudomonas in the pancreas. CONCLUSIONS: Acute pancreatitis impairs host defense against Pseudomonas pneumonia, whereas pneumonia prolongs the course of pancreatitis.
Abstract: BACKGROUND: It has been suggested that the incidence of acute pancreatitis in patients with end stage renal failure is increased. AIMS: To assess the risk of acute pancreatitis in patients on long term peritoneal dialysis and long term haemodialysis compared with the general population, to evaluate its clinical course and outcome, and to identify possible aetiological factors. PATIENTS: All patients who were maintained on long term peritoneal dialysis and/or haemodialysis (total dialysis time more than six weeks) from January 1989 to March 1998 in a large general hospital in The Netherlands. METHODS: Retrospective cohort study. Standardised ratios (as an approximate relative risk) between the incidence of acute pancreatitis in haemodialysis or peritoneal dialysis and the general population were calculated. Possible risk factors were identified. Patients with and without acute pancreatitis were compared. RESULTS: In 269 patients on haemodialysis (total of 614 person years), one patient developed an attack of acute pancreatitis. Patients on haemodialysis did not show an increased risk for acute pancreatitis compared with the general population (standardised ratio 11; 95% confidence interval (CI) 0.275 to 60.5). In 128 patients on peritoneal dialysis (total of 241 person years), seven patients had nine attacks of acute pancreatitis. Patients on peritoneal dialysis had a significantly and highly increased risk for acute pancreatitis (standardised ratio 249; 95% CI 114 to 473). Mortality in this series of nine attacks was 11%. No single aetiological risk factor could be identified. CONCLUSIONS: The risk of acute pancreatitis in patients on long term peritoneal dialysis is significantly and highly increased compared with the general population. The underlying causal mechanisms remain to be elucidated.
Abstract: We found that NCTC11637, the type strain of Helicobacter pylori, the causative agent of peptic ulcer disease and an early risk factor for gastric cancer, is metronidazole resistant. DNA transformation, PCR-based restriction analysis, and DNA sequencing collectively showed that the metronidazole resistance of this strain was due to mutation in rdxA (gene HP0954 in the full genome sequence of H. pylori 26695) and that resistance did not depend on mutation in any of the other genes that had previously been suggested: catalase (katA), ferredoxin (fdx), flavodoxin (fldA), pyruvate:flavodoxin oxidoreductase (porgammadeltaalphabeta), RecA (recA), or superoxide dismutase (sodB). This is in accord with another recent study that attributed metronidazole resistance to point mutations in rdxA. However, the mechanism of rdxA inactivation that we found in NCTC11637 is itself also novel: insertion of mini-IS605, one of the endogenous transposable elements of H. pylori, and deletion of adjacent DNA sequences including 462 bp of the 851-bp-long rdxA gene.
