32 research outputs found

    Parasites, pathogens and commensals in the “low-impact” non-native amphipod host Gammarus roeselii

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    Background: Whilst vastly understudied, pathogens of non-native species (NNS) are increasingly recognised as important threats to native wildlife. This study builds upon recent recommendations for improved screening for pathogens in NNS by focusing on populations of Gammarus roeselii in Chojna, north-western Poland. At this location, and in other parts of continental Europe, G. roeselii is considered a well-established and relatively ‘low-impact’ invader, with little understanding about its underlying pathogen profile and even less on potential spill-over of these pathogens to native species. Results: Using a combination of histological, ultrastructural and phylogenetic approaches, we define a pathogen profile for non-native populations of G. roeselii in Poland. This profile comprised acanthocephalans (Polymorphus minutus Goese, 1782 and Pomphorhynchus sp.), digenean trematodes, commensal rotifers, commensal and parasitic ciliated protists, gregarines, microsporidia, a putative rickettsia-like organism, filamentous bacteria and two viral pathogens, the majority of which are previously unknown to science. To demonstrate potential for such pathogenic risks to be characterised from a taxonomic perspective, one of the pathogens, a novel microsporidian, is described based upon its pathology, developmental cycle and SSU rRNA gene phylogeny. The novel microsporidian Cucumispora roeselii n. sp. displayed closest morphological and phylogenetic similarity to two previously described taxa, Cucumispora dikerogammari Ovcharenko, 2010 and Cucumispora ornata Bojko, 2015. Conclusions: In addition to our discovery extending the host range for the genus Cucumispora Ovcharenko, 2010 outside of the amphipod host genus Dikerogammarus Stebbing, we reveal significant potential for the co-transfer of (previously unknown) pathogens alongside this host when invading novel locations. This study highlights the importance of pre-invasion screening of low-impact NNS and, provides a means to document and potentially mitigate the additional risks posed by previously unknown pathogens

    Lawson criterion for ignition exceeded in an inertial fusion experiment

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    For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

    Increased ADAMTS13 activity in patients with venous thromboembolism

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Increased levels of inflammatory markers and clotting factors have been related to the pathogenesis and prognosis of venous thromboembolism. In particular, the imbalance between VWF and ADAMTS13 has been described in patients with arterial thrombosis. In this study, 77 patients with previous VTE and 77 matched controls were selected for the evaluation of the inflammatory markers, FVW, ADAMTS 13 and D-dimer. The presences of post-thrombotic syndrome and residual vein obstruction were also assessed in patients. Serum levels of TNF-alpha and IL-6 were significantly increased in patients compared to controls (median=2.25 vs 1.59 pg/mL, P <= 0.001; 1.16 vs 0.98 pg/ml, P=0.013, respectively). Plasma levels and activity of VWF (median=150.25 vs 95.39 U/dL, P <= 0.001; 145.26% vs 92.39%, P <= 0.001) and ADAMTS 13 (median=1088.84 vs 950.80 ng/mL, P <= 0.001; 96.03 vs 83.64%, P <= 0.001) were also higher in patients. We further analysed the subgroups of patients with higher risk for VTE recurrence or VTE sequelae, defined as the presence of high D-dimer levels, RVO or PTS. All inflammatory markers were significantly higher in patients with increased D-dimer. The presence of PTS or RVO was not associated with higher inflammatory or coagulation parameters. The increased levels of inflammatory markers and VWF may suggest that there is a persistence of inflammatory activity in patients even at long periods after the VTE episode. In this context, it may be postulated that increased levels of ADAMTS13 could represent a compensatory mechanism against persistently increased levels of VWF. Moreover, increased inflammatory activity was associated with increased D-dimer levels, thus it is possible that this inflammatory activity may also be related to the risk of VTE recurrence. (C) 2012 Elsevier Ltd. All rights reserved.1306889893Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2009/06970-6

    Efficacy and safety of dapsone as a second-line treatment in non-splenectomized adults with immune thrombocytopenic purpura

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    In adults with immune thrombocytopenic purpura (ITP), steroids are usually proposed as first-line therapy, but long-term complete responses are obtained in no more than 20% of patients. For the remaining patients, splenectomy is considered the treatment of choice, with reported cure rates from 60-70%. However, the inherent risks of surgery and sepsis after splenectomy without a guarantee of success justify the search for strategies aimed to avoid splenectomy. Here we retrospectively evaluated the results of dapsone treatment in ITP patients that failed first-line therapy with steroids. These patients received dapsone 100 mg/day for a minimum of 30 days before splenectomy was considered. Efficacy was defined as a sustained rise in platelet counts (50 109/l) clearly attributed to dapsone treatment. Among 52 steroid-dependent or refractory patients, dapsone resulted in sustained increases in platelet counts in 44.2% of patients, after a median follow-up of 21.10 months after treatment initiation. The long-term efficacy of dapsone in this setting is further corroborated by the observation that none of the responding patients required splenectomy in the follow-up, compared to 69.0% of the non-responding patients. Dapsone-related adverse events were mild and promptly reversed by treatment withdrawal. The results of our retrospective analysis suggest that dapsone is a safe and effective second-line agent for steroid-dependent or refractory ITP patients. Because of its well-known safety profile and low cost compared to other potential second-line treatments for ITP, a trial course of dapsone should be viewed as an attractive option before splenectomy in steroid-dependent of refractory adult ITP patients.19748949

    Long-term prospective study of recurrent venous thromboembolism in a Hispanic population

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    The aim of this study was to assess the incidence and risk factors for recurrent venous thromboembolism (VTE) in a Hispanic population. We prospectively followed 343 patients after a first episode of objectively proven VTE. We excluded all patients with VTE at unusual sites, older than 70 years old, with neoplasia, liver or renal chronic disease and antiphospholipid syndrome. Predictors for recurrence were evaluated by Cox model. The probability of recurrent VTE was estimated by the method of Kaplan-Meier. The cumulative probability of recurrent VTE was 19.1% in 5 years and 30.0% in 10 years. Male sex [relative risk (RR) 1.7, 95% confidence interval (CI) 1.0-2.8], spontaneous first VTE (RR 2.9, 95% CI 1.7-5.0) and FII G20210A mutation (RR 4.2, 95% CI 1.9-9.4) were independent risk factors for recurrent VTE. The fibrinogen, coagulation factors VIII, IX, X and XI were measured in 200 patients and were not associated to thrombotic recurrence risk. This study indicates that the incidence of recurrent VTE is high in Hispanics and depends on clinical and laboratory findings. In this population, FII G20210A mutation may represent a specific risk factor for recurrence. The inclusion of different ethnic populations in epidemiological studies of VTE as well as new approaches to the management of anticoagulation therapy in Hispanics is warranted. Blood Coagul Fibrinolysis 21: 660-665 (c) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.217660665Hematology and Hemotherapy Center at State University of Campina

    Performance of a point-of-care device in determining prothrombin time in supra-therapeutic INRs

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Introduction Point-of-care (POC) devices have been widely adopted for monitoring prothrombin time (PT) (INR) following the demonstration of their accuracy compared to standard INR determination. However, guidelines suggest confirmation of POC results when INRs increase above therapeutic range, due to concerns regarding possible inferior performance of POC devices in high INR levels. Unfortunately, patients with supra-therapeutic INRs are underrepresented in studies that validated these devices. Methods We performed a prospective evaluation of the performance of a POC device in monitoring oral anticoagulation in patients with INR values above 3.5 in a University outpatient anticoagulation clinic. During a 6-month period, 2322 INR determinations were performed with a POC device, and results above 3.5 were immediately repeated on an automated coagulometer. Results Dual INR determinations by two methods were obtained in 160 visits, with a mean INR from the POC device of 4.52 +/- 0.96. Both classical statistics and clinical concordance analysis yielded satisfactory results when the two methods were compared. Conclusion Our results demonstrate that POC devices present good correlation with standard laboratory methods for PT determination in supra-therapeutic INRs and that differences in clinical management do not support the need for systematic confirmation of these results in nonbleeding patients.352211216Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Reduced thrombin formation and excessive fibrinolysis are associated with bleeding complications in patients with dengue fever: a case-control study comparing dengue fever patients with and without bleeding manifestations

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Background: Dengue cases have been classified according to disease severity into dengue fever (DF) and dengue hemorrhagic fever (DHF). Although DF is considered a non-severe manifestation of dengue, it has been recently demonstrated that DF represents a heterogeneous group of patients with varied clinical complications and grades of severity. Particularly, bleeding complications, commonly associated to DHF, can be detected in half of the patients with DF. Although a frequent complication, the causes of bleedings in DF have not been fully addressed. Thus, the aim of this study was to perform a comprehensive evaluation of possible pathophysiological mechanisms that could contribute to the bleeding tendency observed in patients with DF. Methods: This is a case-control study that enrolled adults with DF without bleeding and adults with DF and bleeding complications during the defervescence period. Healthy controls were also included. Peripheral blood counts, inflammatory, fibrinolysis and endothelial cell activation markers, and thrombin generation were evaluated in patients and controls. Results: We included 33 adults with DF without complications, 26 adults with DF and bleeding and 67 healthy controls. Bleeding episodes were mild in 15 (57.6%) and moderate in 11 (42.4%) patients, 8 (30.7%) patients had bleedings in multiple sites. Patients with DF and bleedings had lower platelet counts than DF without bleeding (median = 19,500 vs. 203,500/mm3, P < 0,0001). Levels of TNF-alpha, thrombomodulin and VWF were significantly increased in the two dengue groups than in healthy controls, but similar between patients with and without bleedings. Plasma levels of tPA and D-dimer were significantly increased in patients with bleedings (median tPA levels were 4.5, 5.2, 11.7 ng/ml, P < 0.0001 and median D-dimer levels were 515.5, 1028 and 1927 ng/ml, P < 0.0001). The thrombin generation test showed that patients with bleeding complications had reduced thrombin formation (total thrombin generated were 3753.4 in controls, 3367.5 in non-bleeding and 2274.5nM in bleeding patients, P < 0.002). Conclusions: DF can manifest with spontaneous bleedings, which are associated with specific coagulation and fibrinolysis profiles that are not significantly present in DF without this complication. Particularly, thrombocytopenia, excessive fibrinolysis and reduced thrombin formation may contribute to the bleeding manifestations in DF.13Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2008/11518-2

    Microparticles in deep venous thrombosis, antiphospholipid syndrome and Factor V Leiden

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    Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Microparticles (MPs) are blebs released from cellular surfaces during activation/apoptosis. They are procoagulant, pro-inflammatory and could contribute to pathogenesis of deep venous thrombosis (DVT). This study compared the number, cellular origin and procoagulant activity of MPs on DVT patients in different clinical situations: at diagnosis (n = 9, 5F/4M; mean age = 41.11), 1-3 years after warfarin withdrawal (n = 10, 7F/3M; mean age = 32.90), associated to antiphospholipid syndrome (APS; n = 11, 9F/2M; mean age = 33.82), or asymptomatic carriers of Factor V Leiden (FVL; n = 7, 7F/0M; mean age = 34.00) vs healthy controls (CTR). The quantification and characterization were performed by flow cytometry using CD235, CD61, CD45, CD31, CD14, CD45, anti-TF and Annexin V. The plasmatic procoagulant activity was investigated by prothrombin fragment 1 + 2 (F1 + 2) determination. The MPs procoagulant activity was analyzed by D-dimer (DD2) and Thrombin Generation Test (TGT) on a healthy pool of plasmas adjusted or not by their number (10,000 MPs). The MPs percentages were not different between the groups, but absolute number was increased in patients 1-3 years after warfarin withdrawal vs CTR (P = 0.02). There was no difference of the MPs cellular origin comparing patients to controls. TGT using 10,000 MPs was lower on these patients (P = 0.01). APS patients showed a reduction of plasmatic procoagulant activity (P = 0.004), but they were under warfarin therapy. DD2 in the presence of MPs, independently of its number, was higher in patients with DVT at diagnosis (P<0.0001). MPs of patients with spontaneous DVT at diagnosis can promote coagulation activation demonstrated by increased DD2. Even the increased MPs from patients 1-3 years after thrombotic episode generated lower amount of thrombin, they can have a protective effect by activation of Protein C anticoagulant pathway.206367375Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    A novel association of acquired ADAMTS13 inhibitor and acute dengue virus infection

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)BACKGROUND: Dengue is a mosquito-borne viral disease with an increasing incidence worldwide. Thrombocytopenia is a common finding in dengue virus (DV) infection; however, the underlying mechanisms remain unknown. CASE REPORT: Here we provide the first evidence of a case of antibody formation against ADAMTS13 (ADAMTS13 inhibitor) in the course of a severe acute DV infection resulting in thrombotic microangiopathy (TMA). The patient presented with classical dengue symptoms (positive epidemiology, high fever, myalgia, predominantly in the lower limbs and lumbar region for 1 week) and, after 11 days of initial symptoms, developed TMA. Clinical and laboratorial investigation of dengue and TMA was performed. RESULTS: The patient presented with ADAMTS13 inhibitor (IgG) during the acute phase of the disease, without anti-platelet antibodies detectable. Dengue infection had laboratorial confirmation. There were excellent clinical and laboratory responses to 11 serial plasma exchanges. Anti-ADAMTS13 inhibitor disappeared after remission of TMA and dengue resolution. No recurrence of TMA symptoms was observed after 2-year follow-up. CONCLUSIONS: Although the real incidence of dengue-related TMA is unknown, this case provides the basis for future epidemiologic studies on acquired ADAMTS13 deficiency in DV infection. The prompt clinical recognition of this complication and early installment of specific therapy with plasma exchange are likely to improve the outcome of severe cases of dengue.501208212Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)National Institutes of Health [HL-079027]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [FAPESP 2004/03605-1]National Institutes of Health [HL-079027
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