711 research outputs found

    Replacement therapy for bleeding episodes in factor VII deficiency: A prospective evaluation

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    Patients with inherited factor VII (FVII) deficiency display different clinical phenotypes requiring ad hoc management. This study evaluated treatments for spontaneous and traumatic bleeding using data from the Seven Treatment Evaluation Registry (STER). One-hundred one bleeds were analysed in 75 patients (41 females; FVII coagulant activity <1-20%). Bleeds were grouped as haemarthroses (n=30), muscle/subcutaneous haematomas (n=16), epistaxis (n=12), gum bleeding (n=13), menorrhagia (n=16), central nervous system (CNS; n=9), gastrointestinal (GI; n=2) and other (n=3). Of 93 evaluable episodes, 76 were treated with recombinant, activated FVII (rFVIIa), eight with fresh frozen plasma (FFP), seven with plasma-derived FVII (pdFVII) and two with prothrombin-complex concentrates. One-day replacement therapy resulted in very favourable outcomes in haemarthroses, and was successful in muscle/subcutaneous haematomas, epistaxis and gum bleeding. For menorrhagia, single- or multiple-dose schedules led to favourable outcomes. No thrombosis occurred; two inhibitors were detected in two repeatedly treated patients (one post-rFVIIa, one post-pdFVII). In FVII deficiency, most bleeds were successfully treated with single 'intermediate' doses (median 60 µg/kg) of rFVIIa. For the most severe bleeds (CNS, GI) short- or long-term prophylaxis may be optimalPatients with inherited factor VII (FVII) deficiency display different clinical phenotypes requiring ad hoc management. This study evaluated treatments for spontaneous and traumatic bleeding using data from the Seven Treatment Evaluation Registry (STER). One-hundred one bleeds were analysed in 75 patients (41 females; FVII coagulant activity <1-20%). Bleeds were grouped as haemarthroses (n=30), muscle/subcutaneous haematomas (n=16), epistaxis (n=12), gum bleeding (n=13), menorrhagia (n=16), central nervous system (CNS; n=9), gastrointestinal (GI; n=2) and other (n=3). Of 93 evaluable episodes, 76 were treated with recombinant, activated FVII (rFVIIa), eight with fresh frozen plasma (FFP), seven with plasma-derived FVII (pdFVII) and two with prothrombin-complex concentrates. One-day replacement therapy resulted in very favourable outcomes in haemarthroses, and was successful in muscle/subcutaneous haematomas, epistaxis and gum bleeding. For menorrhagia, single- or multiple-dose schedules led to favourable outcomes. No thrombosis occurred; two inhibitors were detected in two repeatedly treated patients (one postrFVIIa, one post-pdFVII). In FVII deficiency, most bleeds were successfully treated with single 'intermediate' doses (median 60 μg/kg) of rFVIIa. For the most severe bleeds (CNS, GI) short- or long-term prophylaxis may be optimal. © Schattauer 2013

    Caspase-8 binding to cardiolipin in giant unilamellar vesicles provides a functional docking platform for bid

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    Caspase-8 is involved in death receptor-mediated apoptosis in type II cells, the proapoptotic programme of which is triggered by truncated Bid. Indeed, caspase-8 and Bid are the known intermediates of this signalling pathway. Cardiolipin has been shown to provide an anchor and an essential activating platform for caspase-8 at the mitochondrial membrane surface. Destabilisation of this platform alters receptor-mediated apoptosis in diseases such as Barth Syndrome, which is characterised by the presence of immature cardiolipin which does not allow caspase-8 binding. We used a simplified in vitro system that mimics contact sites and/or cardiolipin-enriched microdomains at the outer mitochondrial surface in which the platform consisting of caspase-8, Bid and cardiolipin was reconstituted in giant unilamellar vesicles. We analysed these vesicles by flow cytometry and confirm previous results that demonstrate the requirement for intact mature cardiolipin for caspase-8 activation and Bid binding and cleavage. We also used confocal microscopy to visualise the rupture of the vesicles and their revesiculation at smaller sizes due to alteration of the curvature following caspase-8 and Bid binding. Biophysical approaches, including Laurdan fluorescence and rupture/tension measurements, were used to determine the ability of these three components (cardiolipin, caspase-8 and Bid) to fulfil the minimal requirements for the formation and function of the platform at the mitochondrial membrane. Our results shed light on the active functional role of cardiolipin, bridging the gap between death receptors and mitochondria

    Conformational changes and protein stability of the pro-apoptotic protein Bax

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    Pro-apoptotic Bax is a soluble and monomeric protein under normal physiological conditions. Upon its activation substantial structural rearrangements occur: The protein inserts into the mitochondrial outer membrane and forms higher molecular weight oligomers. Subsequently, the cells can undergo apoptosis. In our studies, we focused on the structural rearrangements of Bax during oligomerization and on the protein stability. Both protein conformations exhibit high stability against thermal denaturation, chemically induced unfolding and proteolytic processing. The oligomeric protein is stable up to 90 °C as well as in solutions of 8 M urea or 6 M guanidinium hydrochloride. Helix 9 appears accessible in the monomer but hidden in the oligomer assessed by proteolysis. Tryptophan fluorescence indicates that the environment of the C-terminal protein half becomes more apolar upon oligomerization, whereas the loop region between helices 1 and 2 gets solvent exposed

    Innate control of actin nucleation determines two distinct migration behaviours in dendritic cells

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    Dendritic cell (DC) migration in peripheral tissues serves two main functions: antigen sampling by immature DCs, and chemokine-guided migration towards lymphatic vessels (LVs) on maturation. These migratory events determine the efficiency of the adaptive immune response. Their regulation by the core cell locomotion machinery has not been determined. Here, we show that the migration of immature DCs depends on two main actin pools: a RhoA mDial-dependent actin pool located at their rear, which facilitates forward locomotion; and a Cdc42 Arp2/3-dependent actin pool present at their front, which limits migration but promotes antigen capture. Following TLR4 MyD88-induced maturation, Arp2/3-dependent actin enrichment at the cell front is markedly reduced. Consequently, mature DCs switch to a faster and more persistent mDial-dependent locomotion mode that facilitates chemotactic migration to LVs and lymph nodes. Thus, the differential use of actin-nucleating machineries optimizes the migration of immature and mature DCs according to their specific function

    µ-Calpain Conversion of Antiapoptotic Bfl-1 (BCL2A1) into a Prodeath Factor Reveals Two Distinct alpha-Helices Inducing Mitochondria-Mediated Apoptosis

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    Anti-apoptotic Bfl-1 and pro-apoptotic Bax, two members of the Bcl-2 family sharing a similar structural fold, are classically viewed as antagonist regulators of apoptosis. However, both proteins were reported to be death inducers following cleavage by the cysteine protease µ-calpain. Here we demonstrate that calpain-mediated cleavage of full-length Bfl-1 induces the release of C-terminal membrane active α-helices that are responsible for its conversion into a pro-apoptotic factor. A careful comparison of the different membrane-active regions present in the Bfl-1 truncated fragments with homologous domains of Bax show that helix α5, but not α6, of Bfl-1 induces cell death and cytochrome c release from purified mitochondria through a Bax/Bak-dependent mechanism. In contrast, both helices α5 and α6 of Bax permeabilize mitochondria regardless of the presence of Bax or Bak. Moreover, we provide evidence that the α9 helix of Bfl-1 promotes cytochrome c release and apoptosis through a unique membrane-destabilizing action whereas Bax-α9 does not display such activities. Hence, despite a common 3D-structure, C-terminal toxic domains present on Bfl-1 and Bax function in a dissimilar manner to permeabilize mitochondria and induce apoptosis. These findings provide insights for designing therapeutic approaches that could exploit the cleavage of endogenous Bcl-2 family proteins or the use of Bfl-1/Bax-derived peptides to promote tumor cell clearance

    Force variability during isometric wrist flexion in highly skilled and sedentary individuals

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    The association of expertness in specific motor activities with a higher ability to sustain a constant application of force, regardless of muscle length, has been hypothesized. Ten highly skilled (HS group) young tennis and handball athletes and 10 sedentary (S group) individuals performed maximal and submaximal (5, 10, 20, 50, and 75% of the MVC) isometric wrist flexions on an isokinetic dynamometer (Kin-Com, Chattanooga). The wrist joint was fixed at five different angles (230, 210, 180, 150, and 1300). For each position the percentages of the maximal isometric force were calculated and participants were asked to maintain the respective force level for 5 s. Electromyographic (EMG) activation of the Flexor Carpi Ulnaris and Extensor Digitorum muscles was recorded using bipolar surface electrodes. No significant differences were observed in maximal isometric strength between HS and S groups. Participants of HS group showed significantly (P < 0.05) smaller force coefficient of variability (CV) and SD values at all submaximal levels of MVC at all wrist angles. The CV and SD values remained unaltered regardless of wrist angle. No difference in normalized agonist and antagonist EMG activity was observed between the two groups. It is concluded that long-term practice could be associated with decreased isometric force variability independently from muscular length and coactivation of the antagonist muscles

    The impact of obesity on time spent with the provider and number of medications managed during office-based physician visits using a cross-sectional, national health survey

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    <p>Abstract</p> <p>Background</p> <p>Obesity is associated with morbidity, mortality, and increased health care costs. Few studies have examined the impact of obesity on outpatient office visits. The purpose of this study was to determine if outpatient visits by obese persons required more time with the provider and more prescription medication management compared to visits made by non-obese persons.</p> <p>Methods</p> <p>Obesity status was determined for 9,280 patient visits made by persons aged 18 years or older in the 2006 National Ambulatory Medical Care Survey. Multivariate analyses compared obese and non-obese visits, stratified by sex, for duration of the visit and the number of medications mentioned at the visit.</p> <p>Results</p> <p>Average duration of visit was higher among visits with patients determined to be obese. However, these differences were not considered significant after statistical testing. Visits made by obese female patients were significantly more likely to involve more than two prescription medications (OR 1.26, 95% CI 1.05 - 1.51) and visits made by obese male patients were significantly more likely to involve more than two prescription medications (OR 1.46, 95% CI 1.16 - 1.83) as compared to visits made by non-obese patients.</p> <p>Conclusion</p> <p>Time spent with the provider was found to be greater among visits with obese patients, but not significantly different from visits with non-obese patients. The number of medications for each visit was found to be significantly greater for visits where the patient was considered to be obese. Increased time for the visit and increased numbers of medication for each visit translate into increased costs. These findings document the impact of obesity on our health care system and have great implications on medical care cost and planning.</p

    Effect of having private health insurance on the use of health care services: the case of Spain

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    Background: Several stakeholders have undertaken initiatives to propose solutions towards a more sustainable health system and Spain, as an example of a European country affected by austerity measures, is looking for ways to cut healthcare budgets. Methods: The aim of this paper is to study the effect of private health insurance on health care utilization using the latest micro-data from the European Community Household Panel (ECHP), the Spanish National Health Survey (SNHS) and the European Union Statistics on Income and Living Conditions (EU-SILC). We use matching techniques based on propensity score methods: single match, four matches, bias-adjustment and allowing for heteroskedasticity. Results: The results demonstrate that people with a private health insurance, use the public health system less than individuals without double health insurance coverage. Conclusions: Our conclusions are useful when policy makers design public-private partnership policie

    Controlling the Outcome of the Toll-Like Receptor Signaling Pathways

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    The Toll-Like Receptors (TLRs) are proteins involved in the immune system that increase cytokine levels when triggered. While cytokines coordinate the response to infection, they appear to be detrimental to the host when reaching too high levels. Several studies have shown that the deletion of specific TLRs was beneficial for the host, as cytokine levels were decreased consequently. It is not clear, however, how targeting other components of the TLR pathways can improve the responses to infections. We applied the concept of Minimal Cut Sets (MCS) to the ihsTLR v1.0 model of the TLR pathways to determine sets of reactions whose knockouts disrupt these pathways. We decomposed the TLR network into 34 modules and determined signatures for each MCS, i.e. the list of targeted modules. We uncovered 2,669 MCS organized in 68 signatures. Very few MCS targeted directly the TLRs, indicating that they may not be efficient targets for controlling these pathways. We mapped the species of the TLR network to genes in human and mouse, and determined more than 10,000 Essential Gene Sets (EGS). Each EGS provides genes whose deletion suppresses the network's outputs
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