In Vivo Analysis of the Role of O-Glycosylations of Von Willebrand Factor

The objective of this project was to study the function of O-glycosylations in von Willebrand factor (VWF) life cycle. In total, 14 different murine Vwf cDNAs mutated on one or several O-glycosylations sites were generated: 9 individual mutants, 2 doublets, 2 clusters and 1 mutant with all 9 murine glycosylation sites mutated (Del-O-Gly). We expressed each mutated cDNA in VWF deficient-mice by hydrodynamic injection. An immunosorbent assay with Peanut Agglutinin (PNA) was used to verify the O-glycosylation status. Wild-type (WT) VWF expressed by hepatocytes after hydrodynamic injection was able to bind PNA with slightly higher affinity than endothelial-derived VWF. In contrast, the Del-O-Gly VWF mutant did not bind PNA, demonstrating removal of O-linked glycans. All mutants displayed a normal multimeric pattern. Two mutants, Del-O-Gly and T1255A/T1256A, led to expression levels 50% lower than those induced by WT VWF and their half-life in vivo was significantly reduced. When testing the capacity of each mutant to correct the bleeding time of VWF-deficient mice, we found that S1486A, T1255A, T1256A and the doublet T1255A/T1256A were unable to do so. In conclusion we have shown that O-glycosylations are dispensable for normal VWF multimerization and biosynthesis. It also appears that some O-glycosylation sites, particularly the T1255 and T1256 residues, are involved in the maintenance of VWF plasma levels and are essential for normal haemostasis. As for the S1486 residue, it seems to be important for platelet binding as demonstrated in vitro using perfusion experiments

Anaesthesia and airway management in mucopolysaccharidosis

Abstract This paper provides a detailed overview and dis-cussion of anaesthesia in patients with mucopolysacchari-dosis (MPS), the evaluation of risk factors in these patients and their anaesthetic management, including emergency airway issues. MPS represents a group of rare lysosomal storage disorders associated with an array of clinical mani-festations. The high prevalence of airway obstruction and restrictive pulmonary disease in combination with cardio-vascular manifestations poses a high anaesthetic risk to these patients. Typical anaesthetic problems include airway obstruction after induction or extubation, intubation diffi-culties or failure [can’t intubate, can’t ventilate (CICV)], possible emergency tracheostomy and cardiovascular and cervical spine issues. Because of the high anaesthetic risk, the benefits of a procedure in patients with MPS shoul

Molecular characterization of glucose-6-phosphate dehydrogenase deficient variants in Baghdad city - Iraq

Background: Although G6PD deficiency is the most common genetically determined blood disorder among Iraqis, its molecular basis has only recently been studied among the Kurds in North Iraq, while studies focusing on Arabs in other parts of Iraq are still absent. Methods: A total of 1810 apparently healthy adult male blood donors were randomly recruited from the national blood transfusion center in Baghdad. They were classified into G6PD deficient and non-deficient individuals based on the results of methemoglobin reduction test (MHRT), with confirmation of deficiency by subsequent enzyme assays. DNA from deficient individuals was studied using a polymerase chain reaction-Restriction fragment length polymorphism (PCR-RFLP) for four deficient molecular variants, namely G6PD Mediterranean (563 C®T), Chatham (1003 G®A), A- (202 G®A) and Aures (143 T®C). A subset of those with the Mediterranean variant, were further investigated for the 1311 (C®T) silent mutation. Results: G6PD deficiency was detected in 109 of the 1810 screened male individuals (6.0%). Among 101 G6PD deficient males molecularly studied, the Mediterranean mutation was detected in 75 cases (74.3%), G6PD Chatham in 5 cases (5.0%), G6PD A- in two cases (2.0%), and G6PD Aures in none. The 1311 silent mutation was detected in 48 out of the 51 G6PD deficient males with the Mediterranean variant studied (94.1%). Conclusions: Three polymorphic variants namely: the Mediterranean, Chatham and A-, constituted more than 80% of G6PD deficient variants among males in Baghdad. Iraq. This observation is to some extent comparable to othe

Innate immunity and remodelling

A wide variety of cardiac disease states can induce remodelling and lead to the functional consequence of heart failure. These complex disease states involve a plethora of parallel signal transduction events, which may be associated with tissue injury or tissue repair. Innate immunity is activated in hearts injured in different ways, evident as cytokine release from the heart, activation of toll-like receptors involved in recognizing danger, and activation of the transcription factor nuclear factor kappa B. Nuclear factor kappa B regulates gene programmes involved in inflammation as well as the resolution of inflammation. The impact of this is an enigma; while cytokines, toll-like receptors, and nuclear factor kappa B appear to elicit myocardial protection in studies of preconditioning, the literature strongly indicates a detrimental role for activation of innate immunity in studies of acute ischaemia–reperfusion injury. The impact of activation of cardiac innate immunity on the long-term outcome in in vivo models of hypertrophy and remodelling is less clear, with conflicting results as to whether it is beneficial or detrimental. More research using genetically engineered mice as tools, different models of evoking remodelling, and long-term follow-up is required for us to conclude whether activation of the innate immune system is good, bad, or unimportant in chronic injury models

A Review on the Mechanical Modeling of Composite Manufacturing Processes

© 2016, The Author(s). The increased usage of fiber reinforced polymer composites in load bearing applications requires a detailed understanding of the process induced residual stresses and their effect on the shape distortions. This is utmost necessary in order to have more reliable composite manufacturing since the residual stresses alter the internal stress level of the composite part during the service life and the residual shape distortions may lead to not meeting the desired geometrical tolerances. The occurrence of residual stresses during the manufacturing process inherently contains diverse interactions between the involved physical phenomena mainly related to material flow, heat transfer and polymerization or crystallization. Development of numerical process models is required for virtual design and optimization of the composite manufacturing process which avoids the expensive trial-and-error based approaches. The process models as well as applications focusing on the prediction of residual stresses and shape distortions taking place in composite manufacturing are discussed in this study. The applications on both thermoset and thermoplastic based composites are reviewed in detail

Direct oral anticoagulants for extended thromboprophylaxis in medically ill patients: meta-analysis and risk/benefit assessment

Majed S Al Yami,1,2 Sawsan Kurdi,2,3 Ivo Abraham2,4,5 1Department of Pharmacy Practice, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia; 2Center for Health Outcomes and PharmacoEconomic Research, University of Arizona, Tucson, AZ, USA; 3Department of Pharmacy Practice, University of Dammam, Dammam, Saudi Arabia; 4Department of Pharmacy Practice and Science, College of Pharmacy, University of Arizona, Tucson, AZ, USA; 5Department of Family and Community Medicine, College of Medicine, University of Arizona, Tucson, AZ, USA Background: Standard-duration (7–10 days) thromboprophylaxis with low molecular weight heparin, low dose unfractionated heparin, or fondaparinux in hospitalized medically ill patients is associated with ~50% reduction in venous thromboembolism (VTE) risk. However, these patients remain at high risk for VTE post-discharge. The direct oral anticoagulants (DOACs) apixaban, rivaroxaban and betrixaban have been evaluated for extended-duration (30–42 days) thromboprophylaxis in this population. Methods: We review the efficacy and safety results from the 3 pivotal trials of extended-duration DOAC thromboprophylaxis in medically ill patients. We performed a meta-analysis of these pivotal trials focusing on 6 VTE (efficacy) and three bleeding outcomes (safety). These results were integrated into a quantitative risk/benefit assessment. Results: The trials evaluating extended-duration DOAC thromboprophylaxis in medically ill patients failed to establish clear efficacy and/or safety signals for each agent. Our meta-analysis shows that, as a class, DOACs have selective and partial extended-duration prophylactic activity in preventing VTE events. However, this is associated with a marked increase in the risk of various bleeding events. The risk/benefit analyses fail to show a consistent net clinical benefit of extended-duration DOAC prophylaxis in medically ill patients. Conclusion: At this time, the evidence of safe and effective extended-duration thromboprophylaxis with DOACs in this population is inconclusive. Keywords: venous thromboembolism, direct oral anticoagulants, enoxaparin, thromboprophylaxis, medically ill patient