The risk of recurrent venous thromboembolism in heterozygous carriers of factor V Leiden and a first spontaneous venous thromboembolism

BACKGROUND: Factor V (FV) Leiden is a risk factor for venous thrombosis (VT). Data on its influence on the risk of recurrent venous thromboembolism (VTE) are controversial owing to different study designs and patient cohorts. METHODS: We reevaluated the risk of recurrence among heterozygous carriers and noncarriers of FV Leiden with a first spontaneous proximal VT of the leg and/or pulmonary embolism. Patients with secondary VTE, homozygous FV Leiden, natural inhibitor deficiencies, lupus anticoagulant, cancer, or long-term anticoagulation were excluded. The study end point was objectively documented, symptomatic, recurrent VTE. RESULTS: After discontinuation of oral anticoagulant therapy for a first VTE, we prospectively observed 287 patients, 83 (29%) of whom were heterozygous for FV Leiden. Recurrent VTE was seen in 17 (20%) of 83 patients with and 44 (21.6%) of 204 without FV Leiden. The probability of recurrence among heterozygotes was 12% (95% confidence interval [CI], 8%-16%), 27% (95% CI, 21%-33%), and 27% (95% CI, 21%-33%) after 2, 4, and 6 years, respectively, and was not higher than that among patients without the mutation (16%, 23%, and 34%, respectively). The relative risk of recurrence in heterozygotes was 0.9 (95% CI, 0.5-1.6; P =.60) after adjustment for confounding variables. The risk of recurrence among patients with and without FV Leiden was not different when sex distribution or duration of anticoagulation therapy was taken into account. CONCLUSIONS: The risk of recurrence is similar among carriers and noncarriers of FV Leiden. Heterozygous patients should receive secondary thromboprophylaxis for a similar length of time as patients without FV Leiden.     

MiR-21-5p and miR-126a-3p levels in plasma and circulating angiogenic cells: relationship with type 2 diabetes complications

Innovative biomarkers are required to manage type 2 diabetic patients (T2DM). We focused our study on miR-126-3p and miR-21-5p levels, as biomarkers of endothelial function and inflammation. MiRNAs levels were measured in plasma from 107 healthy subjects (CTR) and 193 diabetic patients (T2DM), 76 without (T2DM NC) and 117 with (T2DM C) complications.When diabetic complication were analysed as a whole, miR-126-3p and miR-21-5p levels declined significantly from CTR to T2DM NC and T2DM C patients. When miRNAs levels were related to specific complications, significantly higher miR-21-5p levels (0.46 ± 0.44 vs. 0.26±0.33, p < 0.001) and significant lower miR-126-3p levels (0.21±0.21 vs. 0.28±0.22, p = 0.032) were found in T2DM with previous major cardiovascular events (MACE) vs. all the others T2DM patients.To confirm these results we focused on circulating angiogenic cells (CACs) from a subgroup of 10 CTR, 15 T2DM NC and 15 T2DM patients with MACE. CACs from T2DM patients expressed higher miR-21-5p and lower miR-126-3p levels than CACs from CTR. Furthermore, CACs from T2DM + MACE showed the highest levels of miR-21-5p.Circulating miR-21-5p and miR-126-3p emerge as dynamic biomarkers of systemic inflammatory/angiogenic status. Their expression levels in CACs from T2DM with MACE suggest a shift from a proangiogenic to a proinflammatory profile.     

Antioxidant treatment attenuates hyperglycemia-induced cardiomyocyte death in rats

Diabetes and oxidative stress concur to cardiac myocyte death in various experimental settings. We assessed whether N-acetyl-L-cysteine (NAC), an antioxidant and glutathione precursor, has a protective role in a rat model of streptozotocin (STZ)-induced diabetes and in isolated myocytes exposed to high glucose (HG). Diabetic rats were treated with NAC (0.5 g/kg per day) or vehicle for 3 months. At sacrifice left ventricle (LV) myocyte number and size, collagen deposition and reactive oxygen species (ROS) were measured by quantitative histological methods. Diabetes reduced LV myocyte number by 29% and increased myocyte volume by 20% compared to non-diabetic controls. NAC protected from myocyte loss (+25% vs. untreated diabetics, P < 0.05) and reduced reactive hypertrophy (-16% vs. untreated diabetics, P < 0.05). Perivascular fibrosis was high in diabetic rats (+88% vs. control, P < 0.001) but prevented by NAC. ROS production and fraction of ROS-positive cardiomyocyte nuclei were drastically raised in diabetic rats (2.4- and 5.1-fold vs. control, P < 0.001) and normalized by NAC. In separate experiments, isolated adult rat ventricular myocytes were incubated in a medium containing high concentrations of glucose (HG, 25 mM) +/- 0.01 mM NAC; myocyte survival (Trypan blue exclusion and apoptosis by TUNEL) and glutathione content were evaluated. The number of dead and apoptotic myocytes increased five and 6.7-fold in HG and glutathione decreased by 48% (P < 0.05). NAC normalized cell death and apoptosis and prevented glutathione loss. NAC effectively protects from hyperglycemia-induced myocyte cell death and compensatory hypertrophy through direct scavenging of ROS and replenishment of the intracellular glutathione content.     

A Micro-Computed Tomography Comparison of the Porosity in Additively Fabricated CuCr1 Alloy Parts Using Virgin and Surface-Modified Powders

Recently, the use of novel CuCr1 surface-modified powder for reliable laser powder-bed fusion (LPBF) manufacturing has been proposed, enabling a broader LPBF processing window and longer powder storage life. Nevertheless, virgin CuCr1 powder is also LPBF processable, on the condition that a high-energy density is employed. In this work, we compare two dense specimens produced from virgin and surface-modified CuCr1 powder. Furthermore, a third sample fabricated from surface-modified powder is characterized to understand an abnormal porosity content initially detected through Archimedes testing. Utilizing high-resolution micro-CT scans, the nature of the defects present in the different samples is revealed. Pores are analyzed in terms of size, morphology and spatial distribution. The micro-CT data reveal that the virgin CuCr1 dense specimen displays keyhole pores plus pit cavities spanning multiple layer thicknesses. On the other hand, the sample fabricated with the surface-modified CuCr1 powder mainly contains small and spherical equi-distributed metallurgical defects. Finally, the CT analysis of the third specimen reveals the presence of a W contamination, favoring lack-of-fusion pores between subsequent LPBF layers. The LPBF melting mode (keyhole or conductive), the properties of the material, and the potential presence of contaminants are connected to the different porosity types and discussed.     

Additive Manufacturing of β-NiAl by Means of Laser Metal Deposition of Pre-Alloyed and Elemental Powders

The additive manufacturing (AM) technique, laser metal deposition (LMD), combines the advantages of near net shape manufacturing, tailored thermal process conditions and in situ alloy modification. This makes LMD a promising approach for the processing of advanced materials, such as intermetallics. Additionally, LMD allows the composition of a powder blend to be modified in situ. Hence, alloying and material build-up can be achieved simultaneously. Within this contribution, AM processing of the promising high-temperature material β-NiAl, by means of LMD, with elemental powder blends, as well as with pre-alloyed powders, was presented. The investigations showed that by applying a preheating temperature of 1100 °C, β-NiAl could be processed without cracking. Additionally, by using pre-alloyed, as well as elemental powders, a single phase β-NiAl microstructure can be achieved in multi-layer build-ups. Major differences between the approaches were found within substrate near regions. For in situ alloying of Ni and Al, these regions are characterized by an inhomogeneous elemental distribution in a layerwise manner. However, due to the remelting of preceding layers during deposition, a homogenization can be observed, leading to a single-phase structure. This shows the potential of high temperature preheating and in situ alloying to push the development of new high temperature materials for AM.     

Human periodontal ligament fibroblasts stimulated by nanocrystalline hydroxyapatite paste or enamel matrix derivative. An in vitro assessment of PDL attachment, migration, and proliferation

We determined the effects of soluble or coated nanocrystalline hydroxyapatite paste (nano-HA) and enamel matrix derivative (EMD) on proliferation, adhesion, and migration of periodontal ligament fibroblasts (PDLs). Cultured PDLs were stimulated with nano-HA paste or EMD in a soluble form or were coated to the surface of cell culture dishes. Proliferation of PDLs on coated nano-HA and EMD was quantified by various methods including bromodeoxyuridine (BrdU) incorporation and Western blot. Cell migration was investigated in a modified Boyden chamber. The surface integrin profile of PDLs was determined using an integrin-specific ELISA, and integrin-specific signaling was measured by immunoblotting of phosphorylated focal adhesion kinase (FAK). Coated nano-HA stimulated PDL proliferation to a larger extent as compared with coated EMD. PDL migration towards a nano-HA or EMD gradient was more efficiently mediated by soluble EMD as compared with nano-HA but vice versa, adhesion of PDLs to compound-coated dishes was more effectively mediated by nano-HA as compared with EMD. Mechanistically, majorly integrin ??5??1-mediated adhesion of PDL and both coated compounds mediated a significant increase in FAK activation though to a different extent. Current findings offer two different modes of action for EMD and nano-HA paste. EMD efficiently acts as a chemoattractant in its soluble form, while nano-HA paste effectively serves as a synthetic extracellular matrix component in its coated form. Our findings suggest that EMD and nano-HA paste display different molecular characteristics and apply alternative routes to mediate their beneficial effects on periodontal tissues.     

Prophylaxis in children with hemophilia: evidence-based achievements, old and new challenges

Recurrent joint bleeding leading to progressive musculoskeletal damage (hemophilic arthropathy), in spite of on-demand replacement with deficient factor concentrates, is the clinical hallmark of severe hemophilia A and B (i.e., the congenital deficiencies of coagulation factors VIII and IX with circulating levels <1 IU/dL). Fifty years of clinical experience, which began in Northern Europe and then initiated in other European countries and in North America, up to the recent randomized clinical trials, have provided definitive evidence that preventing bleeding from an early age through long-term regular prophylactic concentrate infusions limits the adverse clinical consequences of arthropathy and its complications in the quality of life of hemophilic children. Primary prophylaxis started after the first joint bleed and/or before the age of 2 is now the evidence-based, first-choice treatment in severe hemophilia. Interestingly, recent data also suggest a role for early prophylaxis in preventing inhibitor development, the most serious complication of hemophilia therapy. Secondary prophylaxis is aimed to avoid (or delay) the progression of arthropathy. The earlier the treatment is started, the better the outcomes in joint status and quality of life. Although prophylaxis has radically transformed the natural history of severe hemophilia, relevant barriers to its implementation and diffusion remain. Beyond the obvious economic constraints and problems with venous access and long-term adherence, uncertainties regarding the optimal prophylaxis regimen require further evaluation in prospective studies to optimize approaches based on definite outcome measures and cost-effectiveness/cost-utility analyses. Scientific evidence, current clinical strategies, and open issues of prophylaxis in children with hemophilia will be addressed in this review.