338 research outputs found

    New first trimester crown-rump length's equations optimized by structured data collection from a French general population

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    --- Objectives --- Prior to foetal karyotyping, the likelihood of Down's syndrome is often determined combining maternal age, serum free beta-HCG, PAPP-A levels and embryonic measurements of crown-rump length and nuchal translucency for gestational ages between 11 and 13 weeks. It appeared important to get a precise knowledge of these scan parameters' normal values during the first trimester. This paper focused on crown-rump length. --- METHODS --- 402 pregnancies from in-vitro fertilization allowing a precise estimation of foetal ages (FA) were used to determine the best model that describes crown-rump length (CRL) as a function of FA. Scan measures by a single operator from 3846 spontaneous pregnancies representative of the general population from Northern France were used to build a mathematical model linking FA and CRL in a context as close as possible to normal scan screening used in Down's syndrome likelihood determination. We modeled both CRL as a function of FA and FA as a function of CRL. For this, we used a clear methodology and performed regressions with heteroskedastic corrections and robust regressions. The results were compared by cross-validation to retain the equations with the best predictive power. We also studied the errors between observed and predicted values. --- Results --- Data from 513 spontaneous pregnancies allowed to model CRL as a function of age of foetal age. The best model was a polynomial of degree 2. Datation with our equation that models spontaneous pregnancies from a general population was in quite agreement with objective datations obtained from 402 IVF pregnancies and thus support the validity of our model. The most precise measure of CRL was when the SD was minimal (1.83mm), for a CRL of 23.6 mm where our model predicted a 49.4 days of foetal age. Our study allowed to model the SD from 30 to 90 days of foetal age and offers the opportunity of using Zscores in the future to detect growth abnormalities. --- Conclusion --- With powerful statistical tools we report a good modeling of the first trimester embryonic growth in the general population allowing a better knowledge of the date of fertilization useful in the ultrasound screening of Down's syndrome. The optimal period to measure CRL and predict foetal age was 49.4 days (9 weeks of gestational age). Our results open the way to the detection of foetal growth abnormalities using CRL Zscores throughout the first trimester

    Cross-linked amylose bio-plastic: A transgenic-based compostable plastic alternative

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    Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO), an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi© plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material

    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

    Naturally Occurring Lipid A Mutants in Neisseria meningitidis from Patients with Invasive Meningococcal Disease Are Associated with Reduced Coagulopathy

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    Neisseria meningitidis is a major cause of bacterial meningitis and sepsis worldwide. Lipopolysaccharide (LPS), a major component of the Gram-negative bacterial outer membrane, is sensed by mammalian cells through Toll-like receptor 4 (TLR4), resulting in activation of proinflammatory cytokine pathways. TLR4 recognizes the lipid A moiety of the LPS molecule, and the chemical composition of the lipid A determines how well it is recognized by TLR4. N. meningitidis has been reported to produce lipid A with six acyl chains, the optimal number for TLR4 recognition. Indeed, meningococcal sepsis is generally seen as the prototypical endotoxin-mediated disease. In the present study, we screened meningococcal disease isolates from 464 patients for their ability to induce cytokine production in vitro. We found that around 9% of them were dramatically less potent than wild-type strains. Analysis of the lipid A of several of the low-activity strains by mass spectrometry revealed they were penta-acylated, suggesting a mutation in the lpxL1 or lpxL2 genes required for addition of secondary acyl chains. Sequencing of these genes showed that all the low activity strains had mutations that inactivated the lpxL1 gene. In order to see whether lpxL1 mutants might give a different clinical picture, we investigated the clinical correlate of these mutations in a prospective nationwide observational cohort study of adults with meningococcal meningitis. Patients infected with an lpxL1 mutant presented significantly less frequently with rash and had higher thrombocyte counts, consistent with reduced cytokine induction and less activation of tissue-factor mediated coagulopathy. In conclusion, here we report for the first time that a surprisingly large fraction of meningococcal clinical isolates have LPS with underacylated lipid A due to mutations in the lpxL1 gene. The resulting low-activity LPS may have an important role in virulence by aiding the bacteria to evade the innate immune system. Our results provide the first example of a specific mutation in N. meningitidis that can be correlated with the clinical course of meningococcal disease

    Procalcitonin-guided antibiotic use versus a standard approach for acute respiratory tract infections in primary care: study protocol for a randomised controlled trial and baseline characteristics of participating general practitioners [ISRCTN73182671]

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    BACKGROUND: Acute respiratory tract infections (ARTI) are among the most frequent reasons for consultations in primary care. Although predominantly viral in origin, ARTI often lead to the prescription of antibiotics for ambulatory patients, mainly because it is difficult to distinguish between viral and bacterial infections. Unnecessary antibiotic use, however, is associated with increased drug expenditure, side effects and antibiotic resistance. A novel approach is to guide antibiotic therapy by procalcitonin (ProCT), since serum levels of ProCT are elevated in bacterial infections but remain lower in viral infections and inflammatory diseases. The aim of this trial is to compare a ProCT-guided antibiotic therapy with a standard approach based on evidence-based guidelines for patients with ARTI in primary care. METHODS/DESIGN: This is a randomised controlled trial in primary care with an open intervention. Adult patients judged by their general practitioner (GP) to need antibiotics for ARTI are randomised in equal numbers either to standard antibiotic therapy or to ProCT-guided antibiotic therapy. Patients are followed-up after 1 week by their GP and after 2 and 4 weeks by phone interviews carried out by medical students blinded to the goal of the trial. Exclusion criteria for patients are antibiotic use in the previous 28 days, psychiatric disorders or inability to give written informed consent, not being fluent in German, severe immunosuppression, intravenous drug use, cystic fibrosis, active tuberculosis, or need for immediate hospitalisation. The primary endpoint is days with restrictions from ARTI within 14 days after randomisation. Secondary outcomes are antibiotic use in terms of antibiotic prescription rate and duration of antibiotic treatment in days, days off work and days with side-effects from medication within 14 days, and relapse rate from the infection within 28 days after randomisation. DISCUSSION: We aim to include 600 patients from 50 general practices in the Northwest of Switzerland. Data from the registry of the Swiss Medical Association suggests that our recruited GPs are representative of all eligible GPs with respect to age, proportion of female physicians, specialisation, years of postgraduate training and years in private practice
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