Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0243026 (sepsis)
 52,417 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Systemic infection with lymphocytic choriomeningitis virus (LCMV) is accompanied by marked splenomegaly, primarily reflecting the accumulation of CD8(+) T cells with an activated phenotype (e.g. VLA-4hi). Analysis of DNA content using 7-aminoactinomycin-D revealed that as many as 30% of CD8(+) T cells are cycling around day 6 post-infection and that virtually all cycling cells express a high level of VLA-4. In accord with the relatively stable CD4+ cell number, only few cycling CD4+ cells were observed. Following virus control, splenic lymphocyte numbers decreased gradually and during this period many apoptotic cells were detected in the white pulp using terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling. Flow cytometric analysis of DNA content revealed a high frequency of cells with subnormal levels of DNA in the CD8(+)VLA-4hi subset, whereas the frequency was low for other lymphocyte subsets studied (CD4+, CD8+VLA-4lo and B cells). In addition, numbers of CD8+VLA-4hi) cells constitute approximately 30% of splenocytes at the peak of the response and undergo preferential decrease during normalization of splenocyte numbers. Together these findings indicate that LCMV-induced activation of T cells is followed by apoptosis of many of the activated cells. Those CD8+VLA-4hi cells which do persist in LCMV immune mice are more sensitive to treatment with the cell-cycle-specific drug hydroxyurea than are phenotypically naive T cells. Our results therefore indicate that LCMV infection induces polyclonal activation of CD8+ cells which is followed by apoptosis of most of the triggered cells while a smaller subset persists as a primed population which include cycling cells.
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PMID:Virus-induced polyclonal T cell activation is followed by apoptosis: partitioning of CD8+ T cells based on alpha 4 integrin expression. 867 58

Vascular injury in vasculitis may be due to activation of circulating neutrophils resulting in their increased adhesiveness to locally activated endothelium (Shwartzman phenomenon). Previously, we demonstrated up-regulation of endothelial intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in biopsies from patients with ANCA-associated vasculitis. In the present study, we investigated the expression of adhesion molecules (CD11b, ICAM-1, VLA-4, L-selectin) and activation markers (CD66b, CD64, CD63) on circulating neutrophils from patients with ANCA-associated vasculitis in comparison with their expression on cells from healthy volunteers and patients with sepsis. We related these findings to parameters of disease activity. Surface marker expression was determined by using a non-activating whole blood flow cytometric assay. The expression of activation markers, but not the expression of adhesion molecules, was increased on neutrophils from patients with active vasculitis. The expression of CD63 and CD66b on neutrophils correlated with disease activity as determined by the Birmingham Vasculitis Activity Score (BVAS). In contrast to patients with active vasculitis, patients with sepsis showed up-regulation of all markers, including adhesion molecules, suggesting that circulating neutrophils are fully activated in sepsis. We conclude that in ANCA-associated vasculitis, circulating neutrophils are not fully activated, since they do not express increased levels of adhesion molecules as sepsis or in the Shwartzman reaction. These findings are compatible with the concept that in vivo vascular damage in ANCA-associated vasculitides does not occur due to a Shwarzman-like reaction but only after ANCA-induced neutrophil activation at the endothelial cell surface.
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PMID:Are circulating neutrophils intravascularly activated in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides? 984 62

The up-regulation of different adhesion molecules such as VLA-4 (CD49d/CD29) and ICAM-1 (CD54) on the pulmonary endothelium and leukocytes, is a key event in sepsis-induced lung injury leading to inflammatory tissue alterations. The value of VLA-4 and ICAM-1 as micromorphological post-mortem markers for the detection of sepsis-induced lung injury, was evaluated in a semiquantitative immunohistochemical study. VLA-4 was strongly expressed on intravascular, interstitial and intra-alveolar leukocytes in sepsis-associated fatalities, whereas in non-septic fatalities an irregular weak immunoreactivity was observed on interstitial leukocytes and no positive immunohistochemical expression was detected on intravascular or intra-alveolar leukocytes. ICAM-1 was strongly expressed on endothelial cells of the pulmonary microvasculature and on pulmonary macrophages and lymphocytes in sepsis-associated fatalities. In contrast, an infrequent weak immunohistochemical reaction for ICAM-1 was found on pulmonary endothelium and on perivascular leukocytes in non-septic fatalities. Based on the results of the present preliminary study, VLA-4 and ICAM-1 can be considered as useful immunohistochemical post-mortem markers of sepsis.
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PMID:Post-mortem markers of sepsis: an immunohistochemical study using VLA-4 (CD49d/CD29) and ICAM-1 (CD54) for the detection of sepsis-induced lung injury. 1135 15

This review addresses our present-day knowledge on the role of different cellular adhesion molecules, cytokines and glycoproteins for the detection of sepsis-induced injury in the microvasculature of the human lung using immunohistochemistry. Through the induction and modulation of endothelial cell adhesion molecules, such as E-selectin (CD 62E), the vascular endothelium controls leukocyte extravasation into tissue. E-Selectin, not expressed by unstimulated endothelium, is activated by cytokines and initiates neutrophil recruitment in sepsis-induced lung injury. Since E-selectin is strongly expressed in the pulmonary microvasculature in sepsis-associated fatalities, the immunohistochemical detection of an intense expression of E-selectin in lung tissue is a valuable diagnostic tool in the forensic postmortem elucidation of death due to sepsis. VLA-4 (CD49d/CD29) is strongly expressed on intravascular, interstitial and intra-alveolar leukocytes in sepsis-associated fatalities, whereas in non-septic fatalities an irregular weak immunoreactivity can be observed on interstitial leukocytes and no positive immunohistochemical expression can be observed on intravascular or intra-alveolar leukocytes. ICAM-1 (CD54) is strongly expressed on endothelial cells of the pulmonary microvasculature and on pulmonary macrophages and lymphocytes in sepsis-associated fatalities. In contrast, an infrequent weak immunohistochemical reaction for ICAM-1 is found on pulmonary endothelium and on perivascular leukocytes in non-septic fatalities. The up-regulation of both cellular adhesion molecules can be considered as an useful immunohistochemical postmortem marker of sepsis. Lactoferrin (LF) is an iron-binding glycoprotein located in specific (secondary) granules of leukocytes and plays a central role in the host response to infectious stimuli in providing both bacteriostatic and bactericidal protection. There is a statistically significant association between an enhanced expression of LF on pulmonary leukocytes in sepsis-related fatalities in contrast to non-septic controls. The immunohistochemical detection of an enhanced expression of LF can contribute to the postmortem discrimination between sepsis and non-septic fatalities. Application of carbohydrate-specific lectins (ConA, UEA, GSA I, GSA II, MPA, PNA, Jac, WGA, MAA, LPA, SNA) on deparaffinated lung tissue sections from sepsis-associated fatalities and control cases results to some extent in different staining patterns of alveolar epithelial cells and subepithelial seromucous glands of the bronchi. Apart from differences in binding sites for alpha-mannose, N-acetyl-neuraminic acid and alpha-(2-6)-galactose (as detected by different expression for ConA, MAA and SNA), the main finding is that no binding sites for alpha-N-acetyl-galactosamine (as investigated by MPA immunoreactivity) can be detected on alveolar epithelial cells and mucous parts of subepithelial seromucous glands in sepsis cases in contrast to the presence of such binding sites in controls. Since most intracellular pathogens persist in macrophages and epithelial cells during infection, it is likely that these pathogens contribute to a continual deprivation or consumption, respectively, of glycoproteins physiologically secreted by alveolar epithelial and glandular cells at different time points and stages of infection and may, among other mechanisms, by reducing pathogen clearance amplify the inflammatory response. Vascular endothelial growth factor (VEGF), an angiogenic and chemotactic peptide, is abundantly expressed in normal lung tissue, especially in alveolar and bronchial epithelium, glandular cells of the bronchi, and activated alveolar macrophages. Pulmonary VEGF immunostaining differs in sepsis when compared to healthy individuals. In the latter a preponderant strong VEGF immunoreaction can be found on alveolar epithelium (predominately type II pneumocytes), bronchial epithelium and glandular cells of the bronchi and bronchioli, and activated alveolar macrophages. In contrast, in sepsis no VEGF immunopositivity can beivity can be observed on bronchial epithelium or glandular cells of the bronchi and bronchioli, and no or relatively sparse VEGF immunoreactivity is found on alveolar epithelial cells. The precise mechanisms of the decreased pulmonary VEGF expression in septic patients under conditions of intensive care medicine are not clear at present. During the complex cascade of excessive pro-inflammatory and anti-inflammatory mediator release involved in the host's systemic inflammatory response in the development of sepsis-induced lung injury, VEGF expression may be suppressed in sepsis by a hitherto not identified agent or the interaction of different mediators of cellular inflammation. For the detection of sepsis-induced lung injury the aforementioned markers can be used sufficiently, e.g. to give immunohistochemical evidence of a previously undiagnosed sepsis and to confirm or rule out a presumed diagnosis of a sepsis-associated fatality. The employment of the presented immunohistochemical methods will be particularly helpful when macroscopical and routine histological autopsy findings in cases of suspected fatal sepsis are unspecific or unconvincing, respectively, and clinical data on the patient's previous history are not available. Referring to the forensic argumentation regarding causality on the subject of possibly fatal septic complications, e.g. in the sequel of diagnostic or therapeutic iatrogenic injection procedures or being relevant to pressure sore-associated fatalities, aetiopathogenetic conclusions can be optimized on the basis of the described micromorphological investigations.
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PMID:Immunohistochemical detection of sepsis-induced lung injury in human autopsy material. 1293 35

Cecal ligation and puncture (CLP)-induced sepsis in mice was associated with perturbations in vascular adhesion molecules. In CLP mice, lung vascular binding of (125)I-monoclonal antibodies to intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 revealed sharp increases in binding of anti-ICAM-1 and significantly reduced binding of anti-VCAM-1. In whole lung homogenates, intense ICAM-1 up-regulation was found (both in mRNA and in protein levels) during sepsis, whereas very little increase in VCAM-1 could be measured although some increased mRNA was found. During CLP soluble VCAM-1 (sVCAM-1) and soluble ICAM-1 (sICAM-1) appeared in the serum. When mouse dermal microvascular endothelial cells (MDMECs) were incubated with serum from CLP mice, constitutive endothelial VCAM-1 fell in association with the appearance of sVCAM-1 in the supernatant fluids. Under the same conditions, ICAM-1 cell content increased in MDMECs. When MDMECs were evaluated for leukocyte adhesion, exposure to CLP serum caused increased adhesion of neutrophils and decreased adhesion of macrophages and T cells. The progressive build-up in lung myeloperoxidase after CLP was ICAM-1-dependent and independent of VLA-4 and VCAM-1. These data suggest that sepsis disturbs endothelial homeostasis, greatly favoring neutrophil adhesion in the lung microvasculature, thereby putting the lung at increased risk of injury.
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PMID:Disturbed homeostasis of lung intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 during sepsis. 1503 31

Sepsis is a highly lethal disorder characterized by widespread apoptosis-induced depletion of immune cells and the development of a profound immunosuppressive state. IL-7 is a potent antiapoptotic cytokine that enhances immune effector cell function and is essential for lymphocyte survival. In this study, recombinant human IL-7 (rhIL-7) efficacy and potential mechanisms of action were tested in a murine peritonitis model. Studies at two independent laboratories showed that rhIL-7 markedly improved host survival, blocked apoptosis of CD4 and CD8 T cells, restored IFN-gamma production, and improved immune effector cell recruitment to the infected site. Importantly, rhIL-7 also prevented a hallmark of sepsis (i.e., the loss of delayed-type hypersensitivity), which is an IFN-gamma- and T cell-dependent response. Mechanistically, rhIL-7 significantly increased the expression of the leukocyte adhesion markers LFA-1 and VLA-4, consistent with its ability to improve leukocyte function and trafficking to the infectious focus. rhIL-7 also increased the expression of CD8. The potent antiapoptotic effect of rhIL-7 was due to increased Bcl-2, as well as to a dramatic decrease in sepsis-induced PUMA, a heretofore unreported effect of IL-7. If additional animal studies support its efficacy in sepsis and if current clinical trials continue to confirm its safety in diverse settings, rhIL-7 should be strongly considered for clinical trials in sepsis.
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PMID:IL-7 promotes T cell viability, trafficking, and functionality and improves survival in sepsis. 2060 9

Endothelial activation is pivotal in the development and escalation of sepsis. Central to endothelial activation is the endothelial up-regulation of cellular adhesion molecules (CAMs) including E-selectin, ICAM-1, VCAM-1, and PECAM-1. Shed CAMs are also found in circulating soluble forms (sCAMs). We investigated whether sCAMs can be used as biomarkers for the differentiation between septic and non-septic patients. Furthermore, we investigated lymphocyte and monocyte expression of LFA-1 (CD11a/CD18) and VLA-4 (CD49d/CD29) ligands for ICAM-1 and VCAM-1, respectively. Twenty-one septic and 15 critically ill non-septic patients were included. All patients had an APACHE II score above 13 at ICU admission. Fifteen healthy volunteers served as controls. Flow cytometry was used to estimate levels of sE-selectin, sICAM-1, sVCAM-1, sPECAM-1, and the cellular expression of CD11a and CD49d. Levels of sE-selectin, sICAM-1 and sPECAM-1 were higher in the septic patients compared with the non-septic patients and controls at admission and during the observation period. Lymphocyte and monocyte expression of CD11a and CD49d was suppressed or unaltered in the septic patients compared with the non-septic patients and controls. Levels of sE-selectin, sICAM-1, and sPECAM-1 were able to discriminate between septic and non-septic patients, indicating that sCAMs may be potential diagnostic biomarkers of sepsis.
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PMID:The use of the soluble adhesion molecules sE-selectin, sICAM-1, sVCAM-1, sPECAM-1 and their ligands CD11a and CD49d as diagnostic and prognostic biomarkers in septic and critically ill non-septic ICU patients. 2753 81