| 1. |
- Bengtson, Sara H, et al.
(författare)
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Kinin receptor expression during Staphylococcus aureus infection.
- 2006
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 108:6, s. 2055-2063
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Tidskriftsartikel (refereegranskat)abstract
- An inappropriate host response to invading bacteria is a critical parameter that often aggravates the outcome of an infection. Staphylococcus aureus is a major human Gram-positive pathogen that causes a wide array of community- and hospital-acquired diseases ranging from superficial skin infections to severe conditions such as staphylococcal toxic shock. Here we find that S aureus induces inflammatory reactions by modulating the expression and response of the B1 and B2 receptors, respectively. This process is initiated by a chain of events, involving staphylococcal-induced cytokine release from monocytes, bacteria-triggered contact activation, and conversion of bradykinin to its metabolite desArg9bradykinin. The data of the present study implicate an important and previously unknown role for kinin receptor regulation in S aureus infections.
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| 2. |
- Berkestedt, Ingrid, et al.
(författare)
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Early depletion of contact system in patients with sepsis : a prospective matched control observational study
- 2018
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Ingår i: APMIS. - : Wiley. - 0903-4641 .- 1600-0463. ; , s. 892-898
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Tidskriftsartikel (refereegranskat)abstract
- Activation of the contact system generates bradykinin from high-molecular-weight kininogen and has been suggested to participate in the pathophysiology of sepsis. To test this, we prospectively measured bradykinin and high-molecular-weight kininogen levels in a cohort of sepsis patients requiring intensive care. From 29 patients meeting criteria for sepsis or septic shock according to Sepsis-3, blood was sampled within 24 h and on the fourth day following admittance to intensive care. Patients planned for neurosurgery served as matched controls. Sequential organ failure assessment score and 90-day mortality was registered. Bradykinin levels (median [interquartile range]) were lower in sepsis patients (79 [62–172] pg/ml) compared to controls (130 [86–255] pg/ml, p < 0.025) and did not correlate with mortality or severity of circulatory derangement. High-molecular-weight kininogen levels were lower in sepsis patients (1.6 [0.8–4.8] densitometry units) compared to controls (4.4 [2.9–7.7] densitometry units, p < 0.001), suggesting previous contact system activation. High-molecular-weight kininogen levels were lower in non-survivors than survivors (p = 0.003) and negatively correlated to severity of circulatory derangement. We conclude that a role for bradykinin in later stages of severe sepsis must be challenged. Low high-molecular-weight kininogen concentrations suggest that the decrease in bradykinin is due to substrate depletion.
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| 3. |
- Gautam, Narinder, et al.
(författare)
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Heparin-binding protein (HBP/CAP37): A missing link in neutrophil-evoked alteration of vascular permeability
- 2001
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1546-170X .- 1078-8956. ; 7:10, s. 1123-1127
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Tidskriftsartikel (refereegranskat)abstract
- Polymorphonuclear leukocyte infiltration into tissues in host defense and inflammatory diseasecauses increased vascular permeability and edema formation through unknown mechanisms.Here, we report the involvement of a paracrine mechanism in neutrophil-evoked alteration inendothelial barrier function. We show that upon neutrophil adhesion to the endothelial lining,leukocytic 2 integrin signaling triggers the release of neutrophil-borne heparin-binding protein(HBP), also known as CAP37/azurocidin, a member of the serprocidin family of neutrophilcationic proteins. HBP induced Ca++-dependent cytoskeletal rearrangement and intercellular gapformation in endothelial-cell monolayers in vitro, and increased macromolecular efflux in microvesselsin vivo. Moreover, selective inactivation of HBP prevented the neutrophils from inducingendothelial hyperpermeability. Our data suggest a fundamental role of neutrophil-derivedHBP in the vascular response to neutrophil trafficking in inflammation. Targeting this moleculein inflammatory disease conditions offers a new strategy for prevention of endothelial barrierdysfunction caused by misdirected leukocyte activation.
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| 4. |
- Gautam, Narinder, et al.
(författare)
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Signaling via β2 integrins triggers neutrophil-dependent alteration in endothelial barrier function
- 2000
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 191:11, s. 1829-1839
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Tidskriftsartikel (refereegranskat)abstract
- Activation of polymorphonuclear leukocytes (PMNs) and adhesion to the endothelial lining is a major cause of edema formation. Although known to be dependent on the function of β2 integrins (CD11/CD18), the precise mechanisms by which adherent PMNs may impair endothelial barrier capacity remain unclear. Here, the role of transmembrane signaling by β2 integrins in PMN-induced alterations in tight junctional permeability of cultured endothelial cell (EC) monolayers was investigated. PMN activation, in the absence of proinflammatory stimuli, was accomplished through antibody cross- linking of CD11b/CD18, mimicking adhesion-dependent receptor engagement. CD18 cross-linking in PMNs added to the EC monolayer provoked a prompt increase in EC permeability that coincided with a rise in EC cytosolic free Ca2+ and rearrangement of actin filaments, events similar to those evoked by chemoattractant PMN activation. Cell-free supernatant obtained after CD18 cross-linking in suspended PMNs triggered an EC response indistinguishable from that induced by direct PMN activation, and caused clear-cut venular plasma leakage when added to the hamster cheek pouch in vivo preparation. The PMN-evoked EC response was specific to β2 integrin engagement inasmuch as antibody cross-linking of L-selectin or CD44 was without effect on EC function. Our data demonstrate a causal link between outside-in signaling by β2 integrins and the capacity of PMNs to induce alterations in vascular permeability, and suggest a paracrine mechanism that involves PMN-derived cationic protein(s) in the cellular crosstalk between PMNs and ECs.
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| 5. |
- Herwald, Heiko, et al.
(författare)
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Activation of the contact-phase system on bacterial surfaces - A clue to serious comlications in infections deseases
- 1998
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 4:3, s. 298-302
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Tidskriftsartikel (refereegranskat)abstract
- Fever, hypotension and bleeding disorders are common symptoms of sepsis and septic shock. The activation of the contact-phase system is thought to contribute to the development of these severe disease states by triggering proinflammatory and procoagulatory cascades; however, the underlying molecular mechanisms are obscure. Here we report that the components of the contact-phase system are assembled on the surface of Escherichia coil and Salmonella through their specific interactions with fibrous bacterial surface proteins, curli and fimbriae. As a consequence, the proinflammatory pathway is activated through the release of bradykinin, a potent inducer of fever, pain and hypotension. Absorption of contact-phase proteins and fibrinogen by bacterial surface proteins depletes relevant coagulation factors and causes a hypocoagulatory state. Thus, the complex interplay of microbe surface proteins and host contact-phase factors may contribute to the symptoms of sepsis and septic shock.
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| 6. |
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| 7. |
- Johansson, Joakim, et al.
(författare)
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Alteration of Leukocyte Count Correlates With Increased Pulmonary Vascular Permeability and Decreased PaO2:FiO(2) Ratio Early After Major Burns
- 2015
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Ingår i: Journal of Burn Care & Research. - : Lippincott Williams & Wilkins. - 1559-047X .- 1559-0488. ; 36:4, s. 484-492
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Tidskriftsartikel (refereegranskat)abstract
- Leukocytes are activated systemically and their numbers increase soon after a burn followed by a rapid decline to low normal or subnormal levels, possibly by increased extravasation. Experimental data support that an important target for such extravasation is the lungs and that leukocytes when they adhere to endothelial cells cause an increase in vascular permeability. The authors investigated a possible relation between early increased pulmonary vascular permeability or a decreased PaO2:FiO(2) ratio and the dynamic change in concentration of blood leukocytes after a burn. This is a prospective, exploratory, single-center study. The authors measured the dynamic changes of leukocytes in blood starting early after the burn, pulmonary vascular permeability index by thermodilution, and PaO2:FiO(2)-ratios in 20 patients during the first 21 days after a major burn (greater than20% TBSA%). Median TBSA was 40% interquartile range (IQR, 25-52) and full thickness burn 28% (IQR, 2-39). There was a correlation between the early (less than24 hours) alteration in white blood cell count and both early increased pulmonary vascular permeability (r = .63, P = .004) and the decreased oxygenation index defined as PaO2:FiO(2) less than 27 kPa (P = .004). The authors have documented a correlation between dynamic change of blood leukocytes and pulmonary failure early after burns.
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| 8. |
- Johansson, Joakim, et al.
(författare)
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Heparin-binding protein (HBP): an early marker of respiratory failure after trauma?
- 2013
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley-Blackwell. - 0001-5172 .- 1399-6576. ; 57:5, s. 580-586
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Tidskriftsartikel (refereegranskat)abstract
- Background Trauma and its complications contribute to morbidity and mortality in the general population. Trauma victims are susceptible to acute respiratory distress syndrome (ARDS) and sepsis. Polymorphonuclear leucocytes (PMNs) are activated after trauma and there is substantial evidence of their involvement in the development of ARDS. Activated PMNs release heparin-binding protein (HBP), a granule protein previously shown to be involved in acute inflammatory reactions. We hypothesised that there is an increase in plasma HBP content after trauma and that the increased levels are related to the severity of the trauma or later development of severe sepsis and organ failure (ARDS). Methods and Material We investigated HBP in plasma samples within 36h from trauma in 47 patients admitted to a level one trauma centre with a mean injury severity score (ISS) of 26 (2134). ISS, admission sequential organ failure assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were recorded at admission. ARDS and presence of severe sepsis were determined daily during intensive care. Results We found no correlation between individual maximal plasma HBP levels at admission and ISS, admission SOFA or APACHE II. We found, however, a correlation between HBP levels and development of ARDS (P=0.026, n=47), but not to severe sepsis. Conclusion HBP is a potential biomarker candidate for early detection of ARDS development after trauma. Further research is required to confirm a casual relationship between plasma HBP and the development of ARDS.
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| 9. |
- Johansson, Joakim, et al.
(författare)
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Neutrophil-derived heparin binding protein-A mediator of increased vascular permeability after burns?
- 2009
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Ingår i: BURNS. - : Elsevier BV. - 0305-4179 .- 1879-1409. ; 35:8, s. 1185-1187
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Tidskriftsartikel (refereegranskat)abstract
- Increased vascular permeability and oedema formation constitute a major clinical challenge following burns. Several clinical studies show that leukocytes are systemically activated following burns. Neutrophils have the capability to increase vascular permeability via mechanisms thought to involve the release of heparin binding protein (HBP). We hypothesised that HBP is elevated in plasma after major burns due to a systemic inflammatory response and investigated plasma-HBP concentrations in 10 severely burned patients daily for 1 week following the burn. Five-fold higher levels in plasma-HBP concentration compared to a control group were detected on the first day after injury, followed by a steep reduction in the time-period that corresponds to the last part of the hyperpermeability phase. These data are in accordance with the hypothesis that HBP may function as a mediator of the early bum-induced increase in vascular permeability, and call for further studies to confirm a possible cause-and-effect relationship between HBP and oedema formation following burns.
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| 10. |
- Johansson, Linda, et al.
(författare)
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Neutrophil-Derived Hyperresistinemia in Severe Acute Streptococcal Infections
- 2009
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 183:6, s. 4047-4054
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Tidskriftsartikel (refereegranskat)abstract
- The concept of neutrophil activation and degranulation as important contributors to disease pathology in invasive group A streptococcal infections has recently been emphasized. This study focuses on two of the most severe streptococcal manifestations, toxic shock syndrome and necrotizing fasciitis, and the newly described proinflammatory molecule resistin, known to derive from adipocytes and monocytes. We demonstrate for the first time that these conditions are characterized by hyperresistinemia in circulation as well as at the local site of infection. Importantly, analyses of patient tissue biopsies and whole blood revealed that neutrophils represent a novel and dominant source of resistin in bacterial septic shock. This was confirmed by the identification of resistin within neutrophil azurophilic granules. In vitro assays using primary neutrophils showed that resistin release was readily triggered by streptococcal cell wall components and by the streptococcal M1 protein, but not by the potent streptococcal superantigens. This is the first report demonstrating that resistin is released from neutrophils in response to microbial stimuli, which adds resistin to the neutrophil granule proteins that are likely to contribute to the pathologic inflammatory responses associated with severe streptococcal infections. The Journal of Immunology, 2009, 183: 4047-4054.
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