ABSTRACTThe lungs are the remote organ most commonly affected in human peritonitis. The major goa... more ABSTRACTThe lungs are the remote organ most commonly affected in human peritonitis. The major goals of this study were to define the dose- and time-dependent relationship between graded septic peritonitis and systemic and pulmonary inflammatory responses in mice. BALB/c mice were treated with intraperitoneal polymicrobial inoculi and sacrificed at 3, 12, and 24 h. The treatment protocol resulted in distinct groups of animals with respect to mortality rate, kinetics, and concentrations of a broad spectrum of pro- and anti-inflammatory endogenous mediators, intrapulmonary bacterial accumulation, and static lung compliance. In sublethally infected mice, pulmonary bacterial proliferation was controlled. Levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-10, interleukin-6, granulocyte colony-stimulating factor (G-CSF), and tumor necrosis factor (TNF) in plasma were elevated 3 h after infection exclusively. At 3 h, MCP-1, gamma interferon, and TNF were detected in extracts ...
Neutrophils play a key role in the pathophysiology of septic multiple organ dysfunction syndrome ... more Neutrophils play a key role in the pathophysiology of septic multiple organ dysfunction syndrome (MODS) through excessive release of toxic granule components and reactive oxygen metabolites with consequent tissue destruction. The increase of senescent neutrophils during sepsis indicates a potential breakdown of autoregulatory mechanisms including apoptotic processes to remove activated neutrophils from inflammatory sites. Therefore, neutrophil apoptosis of patients with severe sepsis and its regulatory mechanisms were investigated. Spontaneous neutrophil apoptosis from patients with severe sepsis was significantly reduced in comparison to healthy individuals. Cytokines detected in the circulation during sepsis (tumor necrosis factor-α [TNF-α], interferon-γ [IFN-γ], granulocyte colony-stimulating factor [G-CSF], granulocyte-macrophage colony-stimulating factor [GM-CSF]) inhibited neutrophil apoptosis in both groups, though the effect was more distinct in neutrophils from healthy huma...
The lectin pathway of complement is activated when a carbohydrate recognition complex and associa... more The lectin pathway of complement is activated when a carbohydrate recognition complex and associated serine proteases binds to the surface of a pathogen. Three recognition subcomponents have been shown to form active initiation complexes: mannan-binding lectin (MBL), L-ficolin, and H-ficolin. The importance of MBL in antimicrobial host defense is well recognized, but the role of the ficolins remains largely undefined. This report shows that L-ficolin specifically binds to lipoteichoic acid (LTA), a cell wall component found in all Gram-positive bacteria. Immobilized LTA from Staphylococcus aureus binds L-ficolin complexes from sera, and these complexes initiate lectin pathway-dependent C4 turnover. C4 activation correlates with serum L-ficolin concentration, but not with serum MBL levels. L-ficolin binding and corresponding levels of C4 turnover were observed on LTA purified from other clinically important bacteria, including Streptococcus pyogenes and Streptococcus agalactiae. None...
The atrial natriuretic peptide (ANP) is suggested to regulate inflammatory response by alteration... more The atrial natriuretic peptide (ANP) is suggested to regulate inflammatory response by alteration of macrophage functions. The aim of this study was to investigate whether ANP influences production of TNF-α. TNF-α production in murine bone marrow-derived macrophages was induced by LPS, and TNF-α secretion (±ANP) was determined by L929 bioassay. ANP dose dependently (10−8–10−6 M) inhibited TNF-α release by up to 95%. The effect was mediated via the guanylate cyclase-coupled A receptor, as was shown by employing dibutyryl-cGMP, the cGMP-inhibitory compound Ly-83583, and the A receptor antagonist HS-142-1. A specific ligand of the natriuretic peptide “clearance” receptor inhibited TNF-α production only at 10−7 and 10−8 M, but not at 10−6 M. The B receptor ligand C-type natriuretic peptide showed no TNF-α-inhibitory effect. To investigate the underlying mechanism of ANP-mediated TNF-α inhibition, Northern blot was performed. ANP-treated macrophages displayed decreased TNF-α-mRNA levels....
We investigated possible feedback mechanisms of febrile temperatures on LPS- and staphylococcal e... more We investigated possible feedback mechanisms of febrile temperatures on LPS- and staphylococcal enterotoxin B (SEB)-induced cytokine release in human whole blood. LPS-induced IL-1β release was inhibited at temperatures >38°C, whereas intracellular proIL-1β formation as well as the release of other cytokines except IL-18 were only attenuated above 42°C, indicating that febrile temperatures impair the proteolytic processing of proIL-1β. This attenuated processing is not due to either heat inactivation of caspase-1 or structural changes in proIL-1β produced at higher temperatures. Instead, we propose that febrile conditions change cytosolic compartmentation or trafficking, so that synthesized proIL-1β cannot encounter caspase-1. Febrile temperatures also influenced Th1/Th2 cytokine balance. We observed a 3-fold increase in the Th2-cytokines IL-5 and IL-13 and a reduction to 15% of the Th1-cytokine IL-2 when SEB-stimulated whole blood was incubated at 40°C compared with 37°C. These r...
ABSTRACTThe lungs are the remote organ most commonly affected in human peritonitis. The major goa... more ABSTRACTThe lungs are the remote organ most commonly affected in human peritonitis. The major goals of this study were to define the dose- and time-dependent relationship between graded septic peritonitis and systemic and pulmonary inflammatory responses in mice. BALB/c mice were treated with intraperitoneal polymicrobial inoculi and sacrificed at 3, 12, and 24 h. The treatment protocol resulted in distinct groups of animals with respect to mortality rate, kinetics, and concentrations of a broad spectrum of pro- and anti-inflammatory endogenous mediators, intrapulmonary bacterial accumulation, and static lung compliance. In sublethally infected mice, pulmonary bacterial proliferation was controlled. Levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-10, interleukin-6, granulocyte colony-stimulating factor (G-CSF), and tumor necrosis factor (TNF) in plasma were elevated 3 h after infection exclusively. At 3 h, MCP-1, gamma interferon, and TNF were detected in extracts ...
Neutrophils play a key role in the pathophysiology of septic multiple organ dysfunction syndrome ... more Neutrophils play a key role in the pathophysiology of septic multiple organ dysfunction syndrome (MODS) through excessive release of toxic granule components and reactive oxygen metabolites with consequent tissue destruction. The increase of senescent neutrophils during sepsis indicates a potential breakdown of autoregulatory mechanisms including apoptotic processes to remove activated neutrophils from inflammatory sites. Therefore, neutrophil apoptosis of patients with severe sepsis and its regulatory mechanisms were investigated. Spontaneous neutrophil apoptosis from patients with severe sepsis was significantly reduced in comparison to healthy individuals. Cytokines detected in the circulation during sepsis (tumor necrosis factor-α [TNF-α], interferon-γ [IFN-γ], granulocyte colony-stimulating factor [G-CSF], granulocyte-macrophage colony-stimulating factor [GM-CSF]) inhibited neutrophil apoptosis in both groups, though the effect was more distinct in neutrophils from healthy huma...
The lectin pathway of complement is activated when a carbohydrate recognition complex and associa... more The lectin pathway of complement is activated when a carbohydrate recognition complex and associated serine proteases binds to the surface of a pathogen. Three recognition subcomponents have been shown to form active initiation complexes: mannan-binding lectin (MBL), L-ficolin, and H-ficolin. The importance of MBL in antimicrobial host defense is well recognized, but the role of the ficolins remains largely undefined. This report shows that L-ficolin specifically binds to lipoteichoic acid (LTA), a cell wall component found in all Gram-positive bacteria. Immobilized LTA from Staphylococcus aureus binds L-ficolin complexes from sera, and these complexes initiate lectin pathway-dependent C4 turnover. C4 activation correlates with serum L-ficolin concentration, but not with serum MBL levels. L-ficolin binding and corresponding levels of C4 turnover were observed on LTA purified from other clinically important bacteria, including Streptococcus pyogenes and Streptococcus agalactiae. None...
The atrial natriuretic peptide (ANP) is suggested to regulate inflammatory response by alteration... more The atrial natriuretic peptide (ANP) is suggested to regulate inflammatory response by alteration of macrophage functions. The aim of this study was to investigate whether ANP influences production of TNF-α. TNF-α production in murine bone marrow-derived macrophages was induced by LPS, and TNF-α secretion (±ANP) was determined by L929 bioassay. ANP dose dependently (10−8–10−6 M) inhibited TNF-α release by up to 95%. The effect was mediated via the guanylate cyclase-coupled A receptor, as was shown by employing dibutyryl-cGMP, the cGMP-inhibitory compound Ly-83583, and the A receptor antagonist HS-142-1. A specific ligand of the natriuretic peptide “clearance” receptor inhibited TNF-α production only at 10−7 and 10−8 M, but not at 10−6 M. The B receptor ligand C-type natriuretic peptide showed no TNF-α-inhibitory effect. To investigate the underlying mechanism of ANP-mediated TNF-α inhibition, Northern blot was performed. ANP-treated macrophages displayed decreased TNF-α-mRNA levels....
We investigated possible feedback mechanisms of febrile temperatures on LPS- and staphylococcal e... more We investigated possible feedback mechanisms of febrile temperatures on LPS- and staphylococcal enterotoxin B (SEB)-induced cytokine release in human whole blood. LPS-induced IL-1β release was inhibited at temperatures >38°C, whereas intracellular proIL-1β formation as well as the release of other cytokines except IL-18 were only attenuated above 42°C, indicating that febrile temperatures impair the proteolytic processing of proIL-1β. This attenuated processing is not due to either heat inactivation of caspase-1 or structural changes in proIL-1β produced at higher temperatures. Instead, we propose that febrile conditions change cytosolic compartmentation or trafficking, so that synthesized proIL-1β cannot encounter caspase-1. Febrile temperatures also influenced Th1/Th2 cytokine balance. We observed a 3-fold increase in the Th2-cytokines IL-5 and IL-13 and a reduction to 15% of the Th1-cytokine IL-2 when SEB-stimulated whole blood was incubated at 40°C compared with 37°C. These r...
COVID-19 pandemic mitigation strategies are mainly based on social distancing measures and health... more COVID-19 pandemic mitigation strategies are mainly based on social distancing measures and healthcare system reinforcement. However, many countries in Europe and elsewhere implemented strict, horizontal lockdowns because of extensive viral spread in the community which challenges the capacity of the healthcare systems. However, strict lockdowns have various untintended adverse social, economic and health effects, which have yet to be fully elucidated, and have not been considered in models examining the effects of various mitigation measures. Unlike commonly suggested, the dilemma is not about health vs wealth because the economic devastation of long-lasting lockdowns will definitely have adverse health effects in the population. Furthermore, they cannot provide a lasting solution in pandemic containment, potentially resulting in a vicious cycle of consecutive lockdowns with in-between breaks. Hospital preparedness has been the main strategy used by governments. However, a major characteristic of the COVID-19 pandemic is the rapid viral transmission in populations with no immunity. Thus, even the best hospital system could not cope with the demand. Primary, community and home care are the only viable strategies that could achieve the goal of pandemic mitigation. We present the case example of Greece, a country which followed a strategy focused on hospital preparedness but failed to reinforce primary and community care. This, along with strategic mistakes in epidemiological sur- veillance, resulted in Greece implementing a second strict, horizontal lockdown and having one of the highest COVID-19 death rates in Europe during the second wave. We provide recommendations for measures that will reinstate primary and community care at the forefront in managing the current public health crisis by protecting hospitals from unnecessary admissions, providing primary and secondary prevention services in relation to COVID-19 and maintaining population health through treatment of non COVID-19 conditions. This, together with more selective social distancing measures (instead of horizontal lockdowns), represents the only viable and realistic long-term strategy for COVID-19 pandemic mitigation.
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Papers by Thomas Hartung
reinforcement. However, many countries in Europe and elsewhere implemented strict, horizontal lockdowns
because of extensive viral spread in the community which challenges the capacity of the healthcare systems.
However, strict lockdowns have various untintended adverse social, economic and health effects, which have yet
to be fully elucidated, and have not been considered in models examining the effects of various mitigation
measures. Unlike commonly suggested, the dilemma is not about health vs wealth because the economic
devastation of long-lasting lockdowns will definitely have adverse health effects in the population. Furthermore,
they cannot provide a lasting solution in pandemic containment, potentially resulting in a vicious cycle of
consecutive lockdowns with in-between breaks. Hospital preparedness has been the main strategy used by
governments. However, a major characteristic of the COVID-19 pandemic is the rapid viral transmission in
populations with no immunity. Thus, even the best hospital system could not cope with the demand. Primary,
community and home care are the only viable strategies that could achieve the goal of pandemic mitigation. We
present the case example of Greece, a country which followed a strategy focused on hospital preparedness but
failed to reinforce primary and community care. This, along with strategic mistakes in epidemiological sur-
veillance, resulted in Greece implementing a second strict, horizontal lockdown and having one of the highest
COVID-19 death rates in Europe during the second wave. We provide recommendations for measures that will
reinstate primary and community care at the forefront in managing the current public health crisis by protecting
hospitals from unnecessary admissions, providing primary and secondary prevention services in relation to
COVID-19 and maintaining population health through treatment of non COVID-19 conditions. This, together
with more selective social distancing measures (instead of horizontal lockdowns), represents the only viable and
realistic long-term strategy for COVID-19 pandemic mitigation.