The story of a unique molecule in hemophilia A: recombinant single-chain factor VIII

ABSTRACTFor patients with hemophilia A, replacement of deficient factor VIII (FVIII) using plasma-derived or recombinant FVIII (rFVIII) products to restore hemostatic control can reduce bleeding complications and preserve musculoskeletal function. Despite the clinical availability of several of these products, challenges remain in the treatment of hemophilia A, the most notable of which are the risk of inhibitor development and the limited half-life of existing FVIII concentrates, which can make prophylaxis burdensome for patients. The use of recombinant protein technology may lead to novel FVIII products with improved properties. This article describes the story of a unique recombinant FVIII protein, rVIII-SingleChain, which is currently in development. In contrast to native FVIII and other commercially available rFVIII preparations, rVIII-SingleChain uses a strong, covalent bond to connect the light and heavy chains, thereby creating a stable, single-chain rFVIII. It has enhanced intrinsic stability, better integrity after reconstitution, and a higher binding affinity to von Willebrand factor. The physicochemical profile of rVIII-SingleChain and preclinical data on its activity and phamacokinetics strengthened the rationale for its clinical investigation. Available data from the AFFINITY clinical trial program are promising; indicating that it has good hemostatic efficacy when used on demand, for prophylaxis, and in the surgical setting, and is also very well tolerated. A pediatric study and an extension study are ongoing as part of the AFFINITY program

Utilization rates of hip arthroplasty in OECD countries

SummaryBackgroundHip arthroplasty and revision surgery is growing exponentially in OECD countries, but rates vary between countries.MethodsWe extracted economic data and utilization rates data about hip arthroplasty done in OECD countries between 1990 and 2011. Absolute number of implantations and compound annual growth rates were computed per 100,000 population and for patients aged 65 years old and over and for patients aged 64 years and younger.ResultsIn the majority of OECD countries, there has been a significant increase in the utilization of total hip arthroplasty in the last 10 years, but rates vary to a great extent: In the United States, Switzerland, and Germany the utilization rate exceeds 200/100,000 population whereas in Spain and Mexico rates are 102 and 8, respectively. There is a strong correlation between gross domestic product (GDP) and health care expenditures per capita with utilization rate. Utilization rates in all age groups have continued to rise up to present day. A seven fold higher growth rate was seen in patients aged 64 years and younger as compared to older patients.ConclusionWe observed a 38-fold variation in the utilization of hip arthroplasty among OECD countries, correlating with GDP and health care expenditures. Over recent years, there has been an increase in the utilization rate in most countries. This was particularly evident in the younger patients. Due to increasing life expectancy and the disproportionally high use of arthroplasty in younger patients we expect an exponential increase of revision rate in the future

Prospects for measuring the 229Th isomer energy using a metallic magnetic microcalorimeter

The Thorium-229 isotope features a nuclear isomer state with an extremely low energy. The currently most accepted energy value, 7.8 +- 0.5 eV, was obtained from an indirect measurement using a NASA x-ray microcalorimeter with an instrumental resolution 26 eV. We study, how state-of-the-art magnetic metallic microcalorimeters with an energy resolution down to a few eV can be used to measure the isomer energy. In particular, resolving the 29.18 keV doublet in the \gamma-spectrum following the \alpha-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters, and increase the energy accuracy. We study the possibility of resolving the 29.18 keV line as a doublet and the dependence of the attainable precision of the energy measurement on the signal and background count rates and the instrumental resolution.Comment: 32 pages, 8 figures, eq. (3) correcte

Improved Injection Technique of Ethanol for Morton's Neuroma

Background:Morton's neuroma is a common cause of forefoot pain. Various conservative methods (injections of various pharmacologic agents) have been published with an outcome of 6%-75% success rate (free of pain in daily life) per injection. The aim of the present study was to assess the outcome of an improved localization technique, a higher dosage, and a higher percentage of ethanol.Methods:Using fluoroscopic and electroneurographic guidance, 2.5 mL of 70% ethanol were injected into 33 feet with a magnetic resonance imaging (MRI)-verified neuroma. We evaluated patients at up to 5-year follow-up.Results:A "success rate" of more than 82% per single injection (defined as free of pain in daily life) was achieved and no recurrence was seen over 5 years. All scores (visual analog scale; Short Form-36 subscales, American Orthopaedic Foot & Ankle Society ankle-hindfoot score) showed significant improvement (P < .0001). Mean 1.2 injections were necessary. No significant side effects were seen. However, some mild pain persisted in some patients who participated in sports.Conclusion:The injection of 2.5 mL of 70% ethanol under fluoroscopic and electroneurographic guidance was a safe method for the treatment of MRI-verified Morton's neuromas. Combining the effect of a higher percentage of alcohol and a higher dosage and an improved localization technique resulted in a high rate of patients without pain

MEMOSys: Bioinformatics platform for genome-scale metabolic models

<p>Abstract</p> <p>Background</p> <p>Recent advances in genomic sequencing have enabled the use of genome sequencing in standard biological and biotechnological research projects. The challenge is how to integrate the large amount of data in order to gain novel biological insights. One way to leverage sequence data is to use genome-scale metabolic models. We have therefore designed and implemented a bioinformatics platform which supports the development of such metabolic models.</p> <p>Results</p> <p>MEMOSys (MEtabolic MOdel research and development System) is a versatile platform for the management, storage, and development of genome-scale metabolic models. It supports the development of new models by providing a built-in version control system which offers access to the complete developmental history. Moreover, the integrated web board, the authorization system, and the definition of user roles allow collaborations across departments and institutions. Research on existing models is facilitated by a search system, references to external databases, and a feature-rich comparison mechanism. MEMOSys provides customizable data exchange mechanisms using the SBML format to enable analysis in external tools. The web application is based on the Java EE framework and offers an intuitive user interface. It currently contains six annotated microbial metabolic models.</p> <p>Conclusions</p> <p>We have developed a web-based system designed to provide researchers a novel application facilitating the management and development of metabolic models. The system is freely available at <url>http://www.icbi.at/MEMOSys</url>.</p

Thromboembolic events, bleeding, and drug discontinuation in patients with atrial fibrillation on anticoagulation: a prospective hospital-based registry

Abstract Background The clinical practice of stroke prevention in atrial fibrillation (AF) with direct oral anticoagulants (DOACS) differs from anticoagulation in randomized trial patients. We investigated the risk of thromboembolism, bleeding, and drug discontinuation in a hospital-based real-world setting. Methods All-comer patients with non-valvular AF were recruited into a registry at an academic tertiary care center. After informed consent, patients underwent a personal structured interview including medical history, past and current anticoagulation, and returned for follow-up after 6–12 months. Results The registry comprised 282 patients (42% women, median age 71 years) with a median CHA2DS2-Vasc-Score of 4 (25. to 75. percentile 2.5–5), who were prospectively followed 285 days in median. At inclusion, 118 patients took vitamin-K-antagonists, 33 dabigatran, 87 rivaroxaban, 30 apixaban, 5 low-molecular-weight heparin, and 9 were on no anticoagulant. Occurrence of stroke (rate 2.8/100 patient-years), was associated with prior stroke (hazard ratio [HR] 18.5, 95% confidence interval 2.16–159), increased HbA1c (HR per 1% increase 1.71, 1.20–2.45) and borderline significantly associated with vascular disease (HR 8.33, 0.97–71.3). Further we observed a high rate of major bleeding (2.8/100 patient-years), clinically relevant non-major bleeding (4.1/100 patient-years), and venous thromboembolism (2.8/100 patient-years). Anticoagulation was discontinued by 80 patients (36.9/100 patient-years), and diabetes (HR 2.31, 1.32–4.02), history of bleeding (HR 2.51, 1.44–4.37) and elevated leucocyte count (HR per 1G/l increase 1.02, 1.00–1.05) were associated with increased risk of discontinuation. Conclusions In this hospital-based registry, patients with atrial fibrillation had an increased risk of thromboembolic events despite anticoagulation. The low drug persistence may be attributable to distinct comorbid conditions and bleeding complications

A new measure for in vivo thrombin activity in comparison with in vitro thrombin generation potential in patients with hyper- and hypocoagulability

The thrombin generation potential is an in vitro measure for the capacity of an individual to generate thrombin and recognized as a reflection of a hypo- or hypercoagulable status. Measurement of the in vivo thrombin activity, however, may be of clinical significance. We evaluated a new assay for in vivo thrombin activity and compared it to the in vitro thrombin generation potential in patients with hemophilia A (N = 15), oral anticoagulation for atrial fibrillation (AF) (N = 20), subjects with active cancer (N = 21), and healthy volunteers (N = 10). Thrombin activity was measured with a commercially available oligonucleotide enzyme capture assay in argatroban-stabilized plasma samples. Thrombin generation potential was determined with a commercially available assay in citrated plasma. Thrombin activity was detected in 17 (30.4 %) patients (mean 0.30 mU/ml [SD 0.80]), and in 39 patients (69.6 %) no thrombin activity was present. In cancer patients, thrombin activity was detected in 11 patients (52 %) (range 0.14-5.00 mU/ml) and was particularly increased in 3 patients with vessel-invasive tumors (1.2, 1.5, and 5.0 mU/ml). In AF patients, thrombin activity was only measureable in two patients (10 %) (recent hematoma [0.4 mU/ml] and recent ischemic stroke [1.5 mU/ml]). Thrombin activity was detected in four patients (27 %) with hemophilia (range 0.29-1.75 mU/ml), all of whom had received a factor VIII infusion on the same day. Thrombin activity did not correlate with any of the parameters of the thrombin generation potential. Only patients in acute procoagulatory states or after clotting factor replacement had elevated in vivo thrombin activity, which was, however, unrelated to the in vitro thrombin generation potential

QPCR: Application for real-time PCR data management and analysis

BACKGROUND: Since its introduction quantitative real-time polymerase chain reaction (qPCR) has become the standard method for quantification of gene expression. Its high sensitivity, large dynamic range, and accuracy led to the development of numerous applications with an increasing number of samples to be analyzed. Data analysis consists of a number of steps, which have to be carried out in several different applications. Currently, no single tool is available which incorporates storage, management, and multiple methods covering the complete analysis pipeline. RESULTS: QPCR is a versatile web-based Java application that allows to store, manage, and analyze data from relative quantification qPCR experiments. It comprises a parser to import generated data from qPCR instruments and includes a variety of analysis methods to calculate cycle-threshold and amplification efficiency values. The analysis pipeline includes technical and biological replicate handling, incorporation of sample or gene specific efficiency, normalization using single or multiple reference genes, inter-run calibration, and fold change calculation. Moreover, the application supports assessment of error propagation throughout all analysis steps and allows conducting statistical tests on biological replicates. Results can be visualized in customizable charts and exported for further investigation. CONCLUSION: We have developed a web-based system designed to enhance and facilitate the analysis of qPCR experiments. It covers the complete analysis workflow combining parsing, analysis, and generation of charts into one single application. The system is freely available a

Cryogenic micro-calorimeters for mass spectrometric identification of neutral molecules and molecular fragments

We have systematically investigated the energy resolution of a magnetic micro-calorimeter (MMC) for atomic and molecular projectiles at impact energies ranging from $E\approx13$ to 150 keV. For atoms we obtained absolute energy resolutions down to $\Delta E \approx 120$ eV and relative energy resolutions down to $\Delta E/E\approx10^{-3}$. We also studied in detail the MMC energy-response function to molecular projectiles of up to mass 56 u. We have demonstrated the capability of identifying neutral fragmentation products of these molecules by calorimetric mass spectrometry. We have modeled the MMC energy-response function for molecular projectiles and conclude that backscattering is the dominant source of the energy spread at the impact energies investigated. We have successfully demonstrated the use of a detector absorber coating to suppress such spreads. We briefly outline the use of MMC detectors in experiments on gas-phase collision reactions with neutral products. Our findings are of general interest for mass spectrometric techniques, particularly for those desiring to make neutral-particle mass measurements