1,910 research outputs found
Recombinant human activated protein C resets thrombin generation in patients with severe sepsis ā a case control study
INTRODUCTION: Recombinant human activated protein C (rhAPC) is the first drug for which a reduction of mortality in severe sepsis has been demonstrated. However, the mechanism by which this reduction in mortality is achieved is still not clearly defined. The aim of the present study was to evaluate the dynamics of the anticoagulant, anti-inflammatory and pro-fibrinolytic action of rhAPC in patients with severe sepsis, by comparing rhAPC-treated patients with case controls. METHODS: In this prospectively designed multicenter case control study, 12 patients who were participating in the ENHANCE study, an open-label study of rhAPC in severe sepsis, were treated intravenously with rhAPC at a constant rate of 24 Ī¼g/kg/h for a total of 96 h. Twelve controls with severe sepsis matching the inclusion criteria received standard therapy. The treatment was started within 48 h after the onset of organ failure. Blood samples were taken before the start of the infusion and at 4, 8, 24, 48, 96 and 168 h, for determination of parameters of coagulation and inflammation. RESULTS: Sepsis-induced thrombin generation as measured by thrombin-antithrombin complexes and prothrombin fragment F1+2, was reset by rhAPC within the first 8 h of infusion. The administration of rhAPC did not influence parameters of fibrinolysis and inflammation. There was no difference in outcome or occurrence of serious adverse events between the treatment group and the control group. CONCLUSION: Sepsis-induced thrombin generation in severely septic patients is reset by rhAPC within the first 8 h of infusion without influencing parameters of fibrinolysis and inflammation
The effects of continuous venovenous hemofiltration on coagulation activation
INTRODUCTION: The mechanism of coagulation activation during continuous venovenous hemofiltration (CVVH) has not yet been elucidated. Insight into the mechanism(s) of hemostatic activation within the extracorporeal circuit could result in a more rational approach to anticoagulation. The aim of the present study was to investigate whether CVVH using cellulose triacetate filters causes activation of the contact factor pathway or of the tissue factor pathway of coagulation. In contrast to previous studies, CVVH was performed without anticoagulation. METHODS: Ten critically ill patients were studied prior to the start of CVVH and at 5, 15 and 30 minutes and 1, 2, 3 and 6 hours thereafter, for measurement of prothrombin fragment F1+2, soluble tissue factor, activated factor VII, tissue factor pathway inhibitor, kallikreināC1-inhibitor and activated factor XIIāC1-inhibitor complexes, tissue-type plasminogen activator, plasminogen activator inhibitor type I, plasmināantiplasmin complexes, protein C and antithrombin. RESULTS: During the study period the prothrombin fragment F1+2 levels increased significantly in four patients (defined as group A) and did not change in six patients (defined as group B). Group A also showed a rapid increase in transmembrane pressure, indicating clotting within the filter. At baseline, the activated partial thromboplastin time, the prothrombin time and the kallikreināC1-inhibitor complex and activated factor XIIāC1-inhibitor complex levels were significantly higher in group B, whereas the platelet count was significantly lower in group B. For the other studied markers the differences between group A and group B at baseline were not statistically significant. During CVVH the difference in the time course between group A and group B was not statistically significant for the markers of the tissue factor system (soluble tissue factor, activated factor VII and tissue factor pathway inhibitor), for the markers of the contact system (kallikreināC1-inhibitor and activated factor XIIāC1-inhibitor complexes) and for the markers of the fibrinolytic system (plasmināantiplasmin complexes, tissue-type plasminogen activator and plasminogen activator inhibitor type I). CONCLUSION: Early thrombin generation was detected in a minority of intensive care patients receiving CVVH without anticoagulation. Systemic concentrations of markers of the tissue factor system and of the contact system did not change during CVVH. To elucidate the mechanism of clot formation during CVVH we suggest that future studies are needed that investigate the activation of coagulation directly at the site of the filter. Early coagulation during CVVH may be related to lower baseline levels of markers of contact activation
The contribution of CHEK2 to the TP53-negative Li-Fraumeni phenotype
Background: CHEK2 has previously been excluded as a major cause of Li-Fraumeni syndrome (LFS). One particular CHEK2 germline mutation, c.1100delC, has been shown to be associated with elevated breast cancer risk. The prevalence of CHEK21100delC differs between populations and has been found to be relatively high in the Netherlands. The question remains nevertheless whether CHEK2 germline mutations contribute to the Li-Fraumeni phenotype.Methods: We have screened 65 Dutch TP53-negative LFS/LFL candidate patients for CHEK2 germline mutations to determine their contribution to the LFS/LFL phenotype.Results: We identified six index patients with a CHEK2 sequence variant, four with the c.1100delC variant and two sequence variants of unknown significance, p.Phe328Ser and c.1096-?_1629+?del.Conclusion: Our data show that CHEK2 is not a major LFS susceptibility gene in the Dutch population. However, CHEK2 might be a factor contributing to individual tumour development in TP53-negative cancer-prone families
Evaluating the successful implementation of evidence into practice using the PARiHS framework : theoretical and practical challenges
Background
The PARiHS framework (Promoting Action on Research Implementation in Health Services) has proved to be a useful practical and conceptual heuristic for many researchers and practitioners in framing their research or knowledge translation endeavours. However, as a conceptual framework it still remains untested and therefore its contribution to the overall development and testing of theory in the field of implementation science is largely unquantified.
Discussion
This being the case, the paper provides an integrated summary of our conceptual and theoretical thinking so far and introduces a typology (derived from social policy analysis) used to distinguish between the terms conceptual framework, theory and model ā important definitional and conceptual issues in trying to refine theoretical and methodological approaches to knowledge translation.
Secondly, the paper describes the next phase of our work, in particular concentrating on the conceptual thinking and mapping that has led to the generation of the hypothesis that the PARiHS framework is best utilised as a two-stage process: as a preliminary (diagnostic and evaluative) measure of the elements and sub-elements of evidence (E) and context (C), and then using the aggregated data from these measures to determine the most appropriate facilitation method. The exact nature of the intervention is thus determined by the specific actors in the specific context at a specific time and place.
In the process of refining this next phase of our work, we have had to consider the wider issues around the use of theories to inform and shape our research activity; the ongoing challenges of developing robust and sensitive measures; facilitation as an intervention for getting research into practice; and finally to note how the current debates around evidence into practice are adopting wider notions that fit innovations more generally.
Summary
The paper concludes by suggesting that the future direction of the work on the PARiHS framework is to develop a two-stage diagnostic and evaluative approach, where the intervention is shaped and moulded by the information gathered about the specific situation and from participating stakeholders. In order to expedite the generation of new evidence and testing of emerging theories, we suggest the formation of an international research implementation science collaborative that can systematically collect and analyse experiences of using and testing the PARiHS framework and similar conceptual and theoretical approaches.
We also recommend further refinement of the definitions around conceptual framework, theory, and model, suggesting a wider discussion that embraces multiple epistemological and ontological perspectives
End stage renal disease patients have a skewed T cell receptor VĪ² repertoire
BACKGROUND: End stage renal disease (ESRD) is associated with defective T-cell mediated immunity. A diverse T-cell receptor (TCR) VĪ² repertoire is central to effective T-cell mediated immune responses to foreign antigens. In this study, the effect of ESRD on TCR VĪ² repertoire was assessed. RESULTS: A higher proportion of ESRD patients (68.9Ā %) had a skewed TCR VĪ² repertoire compared to age and cytomegalovirus (CMV) ā IgG serostatus matched healthy individuals (31.4Ā %, Pā<ā0.001). Age, CMV serostatus and ESRD were independently associated with an increase in shifting of the TCR VĪ² repertoire. More differentiated CD8(+) T cells were observed in young ESRD patients with a shifted TCR VĪ² repertoire. CD31-expressing naive T cells and relative telomere length of T cells were not significantly related to TCR VĪ² skewing. CONCLUSIONS: ESRD significantly skewed the TCR VĪ² repertoire particularly in the elderly population, which may contribute to the uremia-associated defect in T-cell mediated immunity. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12979-015-0055-7) contains supplementary material, which is available to authorized users
Expression patterns of protein C inhibitor in mouse development
Proteolysis of extracellular matrix is an important requirement for embryonic development and is instrumental in processes such as morphogenesis, angiogenesis, and cell migration. Efficient remodeling requires controlled spatio-temporal expression of both the proteases and their inhibitors. Protein C inhibitor (PCI) effectively blocks a range of serine proteases, and recently has been suggested to play a role in cell differentiation and angiogenesis. In this study, we mapped the expression pattern of PCI throughout mouse development using in situ hybridization and immunohistochemistry. We detected a wide-spread, yet distinct expression pattern with prominent PCI levels in skin including vibrissae, and in fore- and hindgut. Further sites of PCI expression were choroid plexus of brain ventricles, heart, skeletal muscles, urogenital tract, and cartilages. A strong and stage-dependent PCI expression was observed in the developing lung. In the pseudoglandular stage, PCI expression was present in distal branching tubules whereas proximal tubules did not express PCI. Later in development, in the saccular stage, PCI expression was restricted to distal bronchioli whereas sacculi did not express PCI. PCI expression declined in postnatal stages and was not detected in adult lungs. In general, embryonic PCI expression indicates multifunctional roles of PCI during mouse development. The expression pattern of PCI during lung development suggests its possible involvement in lung morphogenesis and angiogenesis
Implementation of nutritional guidelines in a university hospital monitored by repeated point prevalence surveys
Background/Objectives: Malnutrition is present in 20ā50% of hospitalized patients, and nutritional care is a challenge. The aim was to evaluate whether the implementation of a nutritional strategy would influence nutritional care performance in a university hospital. Subjects/Methods: This was a prospective quality improvement program implementing guidelines for nutritional care, with the aim of improving nutritional practice. The Nutrition Risk Screening (NRS) 2002 was used. Point prevalence surveys over 2 years to determine whether nutritional practice had improved. Results: In total, 3604 (70%) of 5183 eligible patients were screened and 1230 (34%) were at nutritional risk. Only 53% of the at-risk patients got nutritional treatment and 5% were seen by a dietician. The proportion of patients screened increased from the first to the eighth point prevalence survey (P=0.012), but not the proportion of patients treated (P=0.66). The four initial screening questions in NRS 2002 identified 92% of the patients not at nutritional risk. Conclusions: Implementation of nutritional guidelines improved the screening performance, but did not increase the proportion of patients who received nutritional treatment. Point prevalence surveys were useful to evaluate nutritional practice in this university hospital. In order to improve practice, we suggest using only the four initial screening questions in NRS 2002 to identify patients not at risk, better education in nutritional care for physicians and nurses, and more dieticians employed. Audit of implementation of guidelines, performed by health authorities, and specific reimbursement for managing nutrition may also improve practice.publishedVersio
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