88 research outputs found
The immunologic effect of early intravenous two and four gram bolus dosing of tranexamic acid compared to placebo in patients with severe traumatic bleeding (TAMPITI): A randomized, double-blind, placebo-controlled, single-center trial
Background: The hemostatic properties of tranexamic acid (TXA) are well described, but the immunological effects of TXA administration after traumatic injury have not been thoroughly examined. We hypothesized TXA would reduce monocyte activation in bleeding trauma patients with severe injury.
Methods: This was a single center, double-blinded, randomized controlled trial (RCT) comparing placebo to a 2 g or 4 g intravenous TXA bolus dose in trauma patients with severe injury. Fifty patients were randomized into each study group. The primary outcome was a reduction in monocyte activation as measured by human leukocyte antigen-DR isotype (HLA-DR) expression on monocytes 72 h after TXA administration. Secondary outcomes included kinetic assessment of immune and hemostatic phenotypes within the 72 h window post-TXA administration.
Results: The trial occurred between March 2016 and September 2017, when data collection ended. 149 patients were analyzed (placebo,
Conclusion: In trauma patients with severe injury, 4 g intravenous bolus dosing of TXA has minimal immunomodulatory effects with respect to leukocyte phenotypes and circulating cytokine levels.
Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02535949
Short-term assays for mesenchymal stromal cell immunosuppression of T-lymphocytes
IntroductionTrauma patients are susceptible to coagulopathy and dysfunctional immune responses. Mesenchymal stromal cells (MSCs) are at the forefront of the cellular therapy revolution with profound immunomodulatory, regenerative, and therapeutic potential. Routine assays to assess immunomodulation activity examine MSC effects on proliferation of peripheral blood mononuclear cells (PBMCs) and take 3–7 days. Assays that could be done in a shorter period of time would be beneficial to allow more rapid comparison of different MSC donors. The studies presented here focused on assays for MSC suppression of mitogen-stimulated PBMC activation in time frames of 24 h or less.MethodsThree potential assays were examined—assays of apoptosis focusing on caspase activation, assays of phosphatidyl serine externalization (PS+) on PBMCs, and measurement of tumor necrosis factor alpha (TNFα) levels using rapid ELISA methods. All assays used the same initial experimental conditions: cryopreserved PBMCs from 8 to 10 pooled donors, co-culture with and without MSCs in 96-well plates, and PBMC stimulation with mitogen for 2–72 h.ResultsSuppression of caspase activity in activated PBMCs by incubation with MSCs was not robust and was only significant at times after 24 h. Monitoring PS+ of live CD3+ or live CD4+/CD3+ mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, 2 h, although no increase in the percentage of PS+ cells was seen with time. The ability of MSC in co-culture to suppress PBMC PS+ externalization compared favorably to two concomitant assays for MSC co-culture suppression of PBMC proliferation, at 72 h by ATP assay, or at 96 h by fluorescently labeled protein signal dilution. TNFα release by mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, with accumulating signal over time. However, suppression levels with MSC co-culture was reliably seen only after 24 h.DiscussionTakeaways from these studies are as follows: (1) while early measures of PBMC activation is evident at 2–6 h, immunosuppression was only reliably detected at 24 h; (2) PS externalization at 24 h is a surrogate assay for MSC immunomodulation; and (3) rapid ELISA assay detection of TNFα release by PBMCs is a robust and sensitive assay for MSC immunomodulation at 24 h
Livro didático público paranaense "lingua portuguesa e literatura" : o professor-autor e o gênero discursivo
Orientadora: Profa. Dra. Iara Bemquerer CostaAutor não autorizou a divulgação do arquivo digitalTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Humanas, Letras e Artes, Programa de Pós-Graduação em Letras. Defesa: Curitiba, 23/04/2012Bibliografia: fls. 163-178Área de concentração :Resumo: Esta pesquisa descritivo-explicativa tem como objetivo averiguar a relacao dialogica entre o Livro Didatico Publico Paranaense \Lingua Portuguesa e Literatura. (LDP-PR) e os livros representantes do genero discursivo Livro Didatico de Lingua Portuguesa (LD-LP). A partir de uma perspectiva socio-historico-discursiva e empregando fontes bibliografica e documental, desenvolvemos esta pesquisa em duas etapas. Na primeira, procuramos efetuar uma reflexao teorica sobre os Generos Discursivos (BAKHTIN) e sobre como a abordagem sociointeracionista se apropria desta concepcao bakhtiniana e discute a questao da didatizacao dos generos (SCHNEUWLY e DOLZ). Na segunda, aplicamos estes pressupostos ao LDP-PR com o intuito de averiguar o encaminhamento didatico dado aos textos de generos discursivos empregados neste material didatico. A partir desta averiguacao do conteudo tematico do LDP-PR, realizada pelo trabalho com as praticas de leitura, escrita e oralidade, buscamos sustentacao para a analise deste LD como um exemplar do genero LD-LP. Nossos resultados mostram que o LDP-PR inova na escolha do conteudo tematico, mas mantem o estilo (marcado pelo emprego de discursos injuntivos, explicativos e expositivos) e a construcao composicional (de textualidade multimodal) tipicos do genero LD-LP. Creditamos a autoria multipla (constituida por professores da rede escolar), marcada pela experiencia reduzida e a merce da Secretaria de Estado da Educacao do Parana (SEED-PR) este apego ao genero consolidado.Abstract: This descriptive-explanatory research aims to investigate the dialogic relationship between the Parana‘s Public Textbook "Portuguese and Literature" (LDP-PR) and the representative books of the discursive genre of Portuguese Textbook (LP-LD). From a socio-historic-discursive perspective and by the use of bibliographical and documentary sources, we developed this research in two stages. In the first one, we carried out a theoretical reflection about the Discursive Genres (BAKHTIN) and how the social interactionist approach appropriates this Bakhtinian concept and discusses the issue of making genre educational (SCHNEUWLY and DOLZ). In the second one, we applied these assumptions to the LDP-PR with the intent of investigating the educational directions given to the texts of discursive genres employed in such a teaching materials. From this investigation of the LDP-PR‘s thematic contents, performed through the work with reading, writing and speaking skills practices, we sought support for the analysis of this LD as an exemplar of the LD-LP genre. Our results reveal that the LDP-PR innovates the choice of the thematic content but retains the style (marked by the use of injunctive, explanatory and expository discourses) and compositional construction (multimodal textuality) that is typical of the LD-LP genre. We attribute to the multiple authorship (made up of teachers from the public educational system), marked by limited experience and at the mercy of the Parana‘s State Department of Education (SEED-PR), this attachment to the consolidated genre
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
Exploring political solutions to the chlorine controversy
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Political Science, 1995.Vita.Includes bibliographical references (p. 65-66).by Andrew P. Cap.M.S
Comparative response of platelet fV and plasma fV to activated protein C and relevance to a model of acute traumatic coagulopathy.
BACKGROUND: Acute traumatic coagulopathy (ATC) has been linked to an increase in activated protein C (aPC) from 40 pM in healthy individuals to 175 pM. aPC exerts its activity primarily through cleavage of active coagulation factor Va (fVa). Platelets reportedly possess fVa which is more resistant to aPC cleavage than plasma fVa; this work examines the hypothesis that normal platelets are sufficient to maintain coagulation in the presence of elevated aPC. METHODS: Coagulation responses of normal plasma, fV deficient plasma (fVdp), and isolated normal platelets in fVdp were conducted: prothrombin (PT) tests, turbidimetry, and thromboelastography (TEG), including the dose response of aPC on the samples. RESULTS: PT and turbidimetric assays demonstrate that normal plasma is resistant to aPC at doses much higher than those found in ATC. Additionally, an average physiological number of washed normal platelets (200,000 platelets/mm3) was sufficient to eliminate the anti-coagulant effects of aPC up to 10 nM, nearly two orders of magnitude above the ATC concentration and even the steady-state pharmacological concentration of human recombinant aPC, as measured by TEG. aPC also demonstrated no significant effect on clot lysis in normal plasma samples with or without platelets. CONCLUSIONS: Although platelet fVa shows slightly superior resistance to aPC's effects compared to plasma fVa in static models, neither fVa is sufficiently cleaved in simulations of ATC or pharmacologically-delivered aPC to diminish coagulation parameters. aPC is likely a correlative indicator of ATC or may play a cooperative role with other activity altering products generated in ATC
Mechanisms of early trauma-induced coagulopathy: the clot thickens or not?
Traumatic-induced coagulopathy (TIC) is a hemostatic disorder that is associated with significant bleeding, transfusion requirements, morbidity and mortality. A disorder similar or analogous to TIC was reported around 70 years ago in patients with shock, hemorrhage, burns, cardiac arrest or undergoing major surgery, and the condition was referred to as a "severe bleeding tendency", "defibrination syndrome", "consumptive disorder.", and later by surgeons treating US Vietnam combat casualties as a "diffuse oozing coagulopathy". In 1982, Moore's group termed it the "bloody vicious cycle", others "the lethal triad", and in 2003 Brohi and colleagues introduced "acute traumatic coagulopathy" (ATC). Since that time, early TIC has been cloaked in many names and acronyms, including a "fibrinolytic form of disseminated intravascular coagulopathy (DIC)". A global consensus on naming is urgently required to avoid confusion. In our view, TIC is a dynamic entity that evolves over time and no single hypothesis adequately explains the different manifestations of the coagulopathy. However, early TIC is not DIC because an increased thrombin-generating potential in vitro does not imply a clinically relevant thrombotic state in vivo as early TIC is characterized by excessive bleeding, not thrombosis. DIC with its diffuse anatomopathologic fibrin deposition appears to be a latter phase progression of TIC associated with unchecked inflammation and multiple organ dysfunction
Platelet supplementation effects on TEG coagulation measurements in fVdp and normal PFP.
<p>(A) While increasing the number of platelets in PFP has very little effect on the initiation of coagulation, a much more powerful response is observed in fVdp as platelets are increased from 10,000/mm<sup>3</sup> to 100,000/mm<sup>3</sup> (***: p<0.001 for the null hypothesis that PFP = fVdp; **: p<0.01; *: p<0.05; n.s.: not significant). Diminishing returns are seen in higher numbers of platelets, with no significant differences observed in the 300,000/mm<sup>3</sup> and 400,000/mm<sup>3</sup> concentrations of platelets compared with equivalent numbers in PFP. (B) Increasing platelets from 10,000/mm<sup>3</sup> to 100,000/mm<sup>3</sup> dramatically improves the alpha angle; the effect plateaus above 150,000 platelets/mm<sup>3</sup>. No alpha angle differences are observed due to the presence of fV protein in the plasma. (C) Similar to rate of clotting, strength of clot rises rapidly with increasing platelet counts until 100,000/mm<sup>3</sup> where a plateau occurs. No significant differences are observed between fVdp and normal PFP with equal numbers of platelets. Means of three samples with standard deviation are shown.</p
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