658 research outputs found
An update on the efficacy and safety of novel anticoagulants for cancer associated thrombosis
No full textIntroduction: Cancer-associated thrombosis (CAT) refers to the most common thromboembolic complication of cancer which is venous thromboembolism (VTE). CAT primary prophylaxis, treatment, and secondary prevention are challenging for the complexity of cancer patients, who exhibit hypercoagulability with concomitant-heightened bleeding risk. Areas covered: In this review, the author examines the role of low molecular weight heparins (LMWH), which have been the standard of care for CAT treatment for many years. Direct oral anticoagulants (DOACS) have practical advantages over subcutaneous LMWH, especially for long-term therapy. The author then discusses the results of two RCTs which separately compared the direct oral factor Xa inhibitors, apixaban or rivaroxaban, with placebo for CAT prophylaxis in ambulatory high-risk cancer patients and found that DOACS reduced VTE but increased bleeding. Finally, the author discusses four RCTS separately comparing an oral direct factor Xa inhibitor (edoxaban, rivaroxaban, or apixaban) with LMWH for CAT treatment. DOACS showed non-inferior efficacy, although rivaroxaban and edoxaban showed higher bleeding rates, especially in gastrointestinal cancers. Expert opinion: DOACS have a convenient route of administration and do not require laboratory monitoring, although choice of anticoagulants for CAT depends on factors such as tumor type, bleeding risk, concomitant drugs, and comorbidities
Heparin-induced thrombocy-topenia and COVID-19
No full textHeparin-induced thrombocytopenia (HIT) has not been included as a possible cause of thrombocytopenia in Coronavirus Disease 2019 (COVID-19) patients. We report a case of HIT in a patient with COVID-19 treated with heparin. A 78-year-old man was admitted to our hospital for acute respiratory failure and acute renal failure due to SARS-CoV-2 infection; in intensive care unit, one 5000IU heparin dose (day 0, platelet count 305000/μL). On day 2, haemoglobin started to decrease and heparin was stopped. On day 10, platelet count was 153000/μL and 5000IU calcium heparin subcutaneously twice daily was started. The platelet further decreased, reaching 49000/μL on day 17, and the patient was investigated for suspected HIT: an IgG specific chemiluminescence test for heparin-PF4 antibodies was positive and a femoral DVT was found at ultrasound. Argatroban was started, platelet count increased without any bleeding and thrombosis complication. Our experience shows that HIT may develop in heparin treated COVID-19 patients and should be included among the possible cause of thrombocytopenia in such patients. © the Author(s), 2021
Multi-goal optimization of a carry-mould
No full textA common engineering task is the optimization of components that are part of multi-body assemblies, in which it is difficult to extrapolate and define the boundary conditions to be applied for the component optimization. This work presents a procedure for multi-goal optimization of components that are integrated in multipart engineering systems. The efficiency of the procedure is illustrated by means of a test case, a carry-mould that is part of a multi-component blowing machinery. Target goals of the optimization process were the minimization of moment of inertia and of global mass and the maximum allowable displacement in a number of control points
Thrombophilia in young women candidate to the pill: Reasons for and against screening
No full textScreening for thrombophilia in women candidate to the pill is still a matter of debate. Oral contraceptives may trigger venous thromboembolic events in carriers of common inherited thrombophilic defects. General screening is not cost-effective from an epidemiological point of view if the objective is to prevent death due to venous thromboembolism during oral contraception (OC). However, clinicians deal with single patients and personal and/ or family history for venous thromboembolism have limited value for identifying those women at risk of VTE complications during OC. A pharmacogenetics approach in prescribing OC on the basis of each woman's genetic make-up could increase drug safety. A proper evaluation of the cost-effectiveness, the medical, psychosocial and legal consequences is needed before general screening with genetic testing for inherited thrombophilia can be recommended before OC. Copyright © 2002 S. Karger AG. Basel
Morphological indexes and structural parameters in trabecular bone micro-models
No full textIt is well known that the mechanical behaviour of cancellous bone depends not only on its mineral content but also on the trabecular architecture, which appears to be the main responsible for trabecular bone anisotropy. In literature, the fourth order tensors that describe the elastic properties of the material (very demanding from the computational point of view) have been related to the anisotropy MIL second order fabric tensors (easily obtainable) [1-6]. Unfortunately, the formulations developed so far between volume fraction, fabric and elastic properties are bone specific and the coefficients found for one bone are not directly applicable to other bones. This is not unexpected since the normalized MIL eigenvalues Hi show a poor correlation to the stiffness components, as shown for example in Figure 1 (a), where healthy bone structures from different species are considered. However, if the normalized values of stiffness Ei are used instead of the apparent elastic moduli E_sim, correlation increases dramatically even for very different bones, like pig and rat in this case, Figure 1 (b).
Starting from these considerations [6], a new approach resulted in a simple general relationship, linking volume fraction and MIL fabric tensor to the trabecular structure stiffness components. The results presented here show that the model can predict approximately 99% of the variation of the numerically computed elastic moduli for the same, healthy, pooled data set (Figure 2) and can be employed also to assess tissue degeneration due to osteoporosis or microgravity (Figure 3).
Figure 1: Pooled data set from different healthy bone structures (pig and rat) - (a) Computed elastic moduli (MPa) vs. MIL normalized eigenvalues - (b) Normalized elastic moduli vs. MIL normalized eigenvalues
Figure 2: Pooled data set from healthy bone structures - Predicted vs. computed elastic moduli (MPa)
Figure 3: Degenerated bone structures - Predicted vs. computed elastic moduli (MPa)
[1] Cowin S.C., "The relationship between the elasticity tensor and the fabric tensor", Mech. Mat., 1985, 4, 137–147.
[2] Van Rietbergen B. et al., "Relationships between bone morphology and bone elastic properties can be accurately quantified using high-resolution computer reconstructions", J. Orth. Res., 1998, 16, 23–28.
[3] Kabel J. et al, "Constitutive relationships of fabric, density, and elastic properties in cancellous bone architecture", Bone, 1999, 25, 481–486.
[4] Homminga J. et al, "The dependence of the elastic properties of osteoporotic cancellous bone on volume fraction and fabric", J. Biomech., 2003, 36, 1461–1467.
[5] Zysset P.K., "A review of morphology–elasticity relationships in human trabecular bone: theories and experiments", J. Biomech., 2003, 36, 1469–1485.
[6] Van Ruijven L.J. et al, "Prediction of mechanical properties of the cancellous bone of the mandibular condyle", J. Dent. Res., 2003, 82(10), 819–823.
[7] Cosmi F., "Morphology-based prediction of elastic properties of trabecular bone samples", Acta Bioeng. Biomech., 11(1), 2009, 3-
"Early thrombus removal" in iliac-femoral deep vein thrombosis for prevention of post-thrombotic syndrome
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The direct oral anticoagulants may also be effective against the risk of post-thrombotic syndrome
No full textThe post-thrombotic syndrome (PTS) is a long-term complication of deep vein thrombosis (DVT) of the lower limbs occurring in 40–50% of patients (1). Impaired thrombus resolution with persistent obstruction is involved in the pathogenesis of PTS, similarly to chronic thromboembolic pulmonary hypertension (CTEPH), which however develops only in a small minority of subjects after pulmonary embolism (PE)(2). Both PTS and CTEPH are associated with substantial morbidity and high healthcare expenses (2). PTS epidemiology reflects that of venous thromboembolism (VTE), which is estimated to affect 104–183 subjects per 100,000 person-years among Caucasians (3, 4), encompassing PE and DVT, with an incidence ranging from 29 to 78 and 45 to 117, per 100,000 person-years, respectively (5, 6). PTS can occur in severe forms in 10% and with the development of leg ulcers in 1–3% of patients (1). Leg ulcers ..
Andexanet alfa to reverse the anticoagulant activity of factor Xa inhibitors: a review of design, development and potential place in therap
No full textDirect oral anticoagulants are associated with rates of major bleeding which are not negligible, albeit lower than those associated with vitamin K antagonists. No specific reversal agent for factor Xa (FXa) direct inhibitors is currently available for clinical use. A modified activated human FXa decoy protein, andexanet alfa, is being developed that binds FXa direct inhibitors in their active site, thus reversing their anticoagulant effect. The purpose of this article is to review the design, development and clinical trials of andexanet alfa. Andexanet alfa was shown to reverse FXa inhibitors anticoagulant activity both in thrombosis animal models, healthy volunteers and patients with acute major bleeding. Andexanet alfa has been studied in double-blind, placebo-controlled phase II and III studies. A preliminary report of the phase III study showed that an effective hemostasis was obtained after andexanet alfa infusion in the majority of the patients with acute major bleeding associated with FXa inhibitors. Additional studies are ongoing and andexanet alfa is expected to be launched in the market in the near future
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