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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Molecular biology has provided new technology for evaluating the traits of bacterial pathogens that are important in the pathogenesis of infections. The ability to derive isogenic strains that differ by a single trait provides a powerful tool for investigating the interaction of a putative virulence factor with the host at any of the various steps in pathogenesis. Recombinant DNA techniques afford the opportunity to clone the genes involved in the biosynthesis of a particular virulence factor. Once the gene(s) are cloned, a vast amount of information can be learned about their composition, structure, and regulation, and similarity with genes in other organisms. Understanding the molecular biology of a virulence factor also provides information about potential targets for future therapies and preventive modalities. The molecular analysis of two virulence factors from the type III group B streptococcus has been reviewed to provide specific examples of how these techniques can be used. The data has shown that the capsular polysaccharide is an essential factor in GBS virulence. The structural influence of sialic acid on the capsule plays a major role in its virulence properties. The importance of the capsule has been tested in several assays to identify its role in pathogenesis. Its primary role appears to be evading host phagocytic mechanisms, but it does not appear to be essential in the vascular response observed during GBS sepsis. Using the isogenic strains, we have also learned that the capsule does not mask a fibronectin receptor on GBS. In contrast to the capsule, the beta-hemolysin of GBS does not appear to be essential for systemic disease once the organism has invaded. Its role in the initial invasive steps in GBS pathogenesis has not been tested, but the availability of isogenic mutants in beta-hemolysin production will allow this question to be answered once the model systems are available.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Molecular analysis of two group B streptococcal virulence factors. 217 47

Fibronectin is a large-molecular-weight glycoprotein present on most cell surfaces, in extracellular fluids, and in plasma. Both cell-associated and soluble fibronectin are thought to have important roles in the inflammatory response and host defense and may contribute to the maintenance of microvascular integrity during septic episodes. Newborn infants have levels of fibronectin in plasma that are one-third to one-half those found in the healthy adult. In addition, neonates with respiratory distress syndrome, perinatal asphyxia, bacterial sepsis, intrauterine growth retardation, or postnatal malnutrition have a further depression in their plasma levels of fibronectin. The low plasma concentration of fibronectin in newborn infants may contribute to the hypofunction of the neonatal reticuloendothelial system and predispose to the development of sepsis. Rates of synthesis of plasma fibronectin are diminished in the neonate, and an inverse correlation between fibronectin half-life and gestational age exists. The role of fibronectin in treatment or prophylaxis of neonatal sepsis remains to be determined.
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PMID:Role of fibronectin in diseases of newborn infants and children. 219 69

The physiological immunodeficiency of preterm and term newborns is the major cause of their increased susceptibility to infections. Although nonspecific and specific host defence mechanisms are morphologically intact, there are functional and quantitative defects. Supportive immunotherapy is required to equalize these immunological defects. This article reviews topical possibilities for immunotherapy of neonatal sepsis (exchange transfusion, transfusion of fresh blood or fresh plasma, granulocyte transfusion, use of immunoglobulins, fibronectin, interferon and colony-stimulating factor).
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PMID:[Neonatal sepsis: bases and possibilities for immunotherapy and immunoprophylaxis. 2: Immunotherapy]. 223 77

Optimal expectant management of preterm premature rupture of membranes (PROM) requires the early detection of chorioamnionitis. To date, however, no universally sensitive and specific marker for chorioamnionitis has been identified. Recently, the serial determination of plasma fibronectin, antithrombin, and prekallikrein has been reported to facilitate the early detection of sepsis in critically ill neonates and adult surgical patients. A cross-sectional study was undertaken to determine if plasma levels of these markers change significantly in patients with overt chorioamnionitis following expectant management of preterm PROM. Plasma levels of fibronectin and prekallikrein were not significantly different between the study (30 patients with overt chorioamnionitis following preterm PROM) and control (30 undelivered patients without antenatal complication matched for gestational age) groups. Antithrombin levels were significantly lower in the study group (p less than 0.05), but the magnitude of the difference (102% versus 94%) is not likely to be of clinical significance. We conclude that determination of plasma levels of fibronectin, prekallikrein, and antithrombin is not likely to aid in the early detection of chorioamnionitis in the setting of preterm (PROM).
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PMID:Evaluation of potential early markers of chorioamnionitis associated with preterm premature ruptured membranes. 229 8

Plasma fibronectin was measured with Laurell's immunoelectroassay in 44 patients with meningococcal sepsis. The average value (15.0 +/- 7.9 mg/dl) was lower than that in normal children (27.4 +/- 8.7 mg/dl) (p less than 0.001). Fibronectin in patients correlated positively with antithrombin III (AT-III) values (p less than 0.02), but not with protein C (0.05 less than p less than 0.1). The decrease of fibronectin had no prognostic value. The fibronectin levels were lower in patients with disseminated intravascular coagulation (DIC+), than in those without DIC (DIC-) (p less than 0.02), but were lower in both groups than in a normal control group. A negative correlation between fibronectin and protein C was only present in DIC- patients (r: -0.773 = p less than 0.01). Fibronectin varied independent of AT-III and protein C in DIC+ patients. The study was repeated in 11 patients 24 hours after admission when fibronectin had decreased in 7/11 cases (mean decrease: -2.7 +/- 8.7 mg/dl). This variation correlated in a negative way with AT-III (r: -0.659 = p less than 0.05). In meningococcal sepsis fibronectin decreases very early, even in DIC- patients and its relationship to AT-III and protein C is different, depending on the presence of DIC and on the stage of evolution of the disease.
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PMID:Fibronectin in meningococcal sepsis. Correlation with antithrombin III and protein C. 231 65

There is evidence that undernutrition may contribute to the reduction in plasma fibronectin concentration and the depression of the reticuloendothelial (RE) system associated with severe sepsis. We have investigated the effects of fasting, surgical trauma and sepsis on plasma fibronectin concentrations and RE function. In experiment 1, plasma fibronectin was measured in rabbits (n = 14) before and 48 h after fasting. In experiment 2, sepsis was induced by devascularization of the appendix in animals on a normal diet (sepsis group, n = 7). A third group of animals underwent only a laparotomy (laparotomy only group, n = 7). Plasma fibronectin concentrations and the blood clearance and organ distribution of 99mtechnetium tin colloid (TTC) were measured 24 h after operation. Compared with pooled reference plasma, fasting in experiment 1 resulted in a reduction in mean(s.e.m.) plasma fibronectin concentration from 98(1.5) per cent to 86(3.7) per cent (T = 2, P less than 0.005). Mean(s.e.m.) plasma fibronectin concentration was raised in the sepsis group to 117(4.6) per cent, compared with 97(2.5) per cent in the laparotomy only group (U = 5, P less than 0.02), but there was no such increase in the fasting and sepsis group. There was a delay in the blood clearance and reduced hepatic uptake of TTC in both sepsis groups. The dissociation between fibronectin concentrations and RE function in animal models of sepsis casts doubt on the importance of fibronectin in RE function.
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PMID:Effect of acute starvation on plasma fibronectin response to sepsis. 231 81

Bacteremia from gram-negative rods is a great cause of concern for hospital physicians today. Shock-complicating gram-negative sepsis has a mortality rate of 60% and above, despite early diagnosis and treatment. Intensive research efforts have shown new pathophysiological mechanisms and mediators involved in septic shock, with changes in recommended treatment protocols. In this report, the authors review the use of corticosteroids, fibronectin, naloxone hydrochloride, and immunotherapy, with emphasis on theoretical considerations and relevant clinical experience. Although these treatment methods may have been promising initially, data from large double-blind human trials are either lacking or unencouraging. While continued research and modern therapeutic approaches should improve future survival rates from septic shock, use of the therapies reviewed should be considered experimental at this time.
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PMID:Modern approaches to the therapy of septic shock. 240 67

Plasma Fibronectin (Fn) has been viewed as an essential opsonic mediator of the clearance function of the reticuloendothelial system (RES). An acute depletion of Fn would thus weaken the RES defense potential, which could be restored by Fn repletion. This concept, which was developed by Saba, has attracted considerable attention. Upon closer inspection, however, it turns out to be more complex and less clear cut than is commonly appreciated. The recent interest of acute care physicians is focussed on the behaviour of Fn during intravascular coagulation, organ failure, and sepsis. However, the informative content of plasma Fn levels in this setting is limited, too. The behaviour of Fn is only one part of a broader plasma protein "depletion and recovery syndrome" and therapeutic effects of Fn repletion have as yet not been adequately documented by controlled clinical trials. The use of plasma fibronectin as a part of intensive care is therefore premature, and the concept underlying its use requires further investigation.
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PMID:[Review. The intensive medical care relevance of plasma fibronectin]. 243 63

In the present study plasma fibronectin levels were determined in patients with hematopoietic malignancy, particularly leukemias, in an effort to clarify their clinical implications. Among leukemia patients, those with AML, ALL, ATL or CLL had various plasma fibronectin levels that were higher in some cases, while lower in others, as compared to normal control values. An elevation of the fibronectin level was noted often in APL, while lower fibronectin values were observed in many instances of CML. In these types of leukemia, acute exacerbation as well as supervention of infection tended to be associated with lower than normal levels of fibronectin. An especially marked depression of fibronectin occurred, when leukemia was complicated by sepsis or DIC, in which a good parallel was noted between the progress of disease and the fibronectin level. In lymphoproliferative diseases, the fibronectin value varied widely, but low fibronectin levels were frequently associated with intercurrent infection or an extreme deterioration of the general physical conditions.
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PMID:Variation of plasma fibronectin levels in leukemia patients. 248 45

Fatal multiple organ failure after severe infection may be related to an early activation of protease cascade systems. This study aimed to relate changes in coagulation, fibrinolysis, and kallikrein to shock and outcome. Of 53 patients with severe infection, 30 did not develop shock, 12 survived septic shock, and 11 died from organ failure after septic shock. No patient had overt disseminated intravascular coagulation. We measured 17 components of the coagulation/fibrinolysis/kallikrein pathways on admission and on the next 2 days. High values for fibrinogen, factor VIII:C, von Willebrand factor antigen, and D-dimer were seen in all patients; factor XII, prekallikrein, factor VII, antithrombin, protein C, and fibronectin were low. The patients thus appeared to be hypercoagulable. These disturbances were more pronounced in septic shock survivors, who also had low plasminogen and antiplasmin, indicating ongoing fibrinolysis. Nonsurvivors of sepsis were distinguished mainly by high plasminogen activator inhibitor values; this suggests an impaired functional fibrinolysis in fatal sepsis, with possible therapeutic implications. Cryoprecipitate infusion increased the fibronectin concentration, but did not influence the other factors studied.
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PMID:Coagulation, fibrinolysis, and kallikrein systems in sepsis: relation to outcome. 250 62


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