A systematic review and meta-analysis of the incidence of post-thrombotic syndrome, recurrent thromboembolism, and bleeding after upper extremity vein thrombosis.

BACKGROUND: Data on complications after upper extremity vein thrombosis (UEVT) are limited and heterogeneous. METHODS: The aim of the present study was to evaluate the pooled proportions of venous thromboembolism (VTE) recurrence, bleeding, and post-thrombotic syndrome (PTS) in patients with UEVT. A systematic literature review was conducted of PubMed, Embase, and the Cochrane Library databases from January 2000 to April 2023 in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. All studies included patients with UEVT and were published in English. Meta-analyses of VTE recurrence, bleeding, and of PTS after UEVT were performed to compute pooled estimates and associated 95% confidence intervals (CIs). Subgroup analyses of cancer-associated UEVT and catheter-associated venous thrombosis were conducted. Patients with Paget-Schroetter syndrome or effort thrombosis were excluded. RESULTS: A total of 55 studies with 15,694 patients were included. The pooled proportions for VTE recurrence, major bleeding, and PTS were 4.8% (95% CI, 3.8%-6.2%), 3.0% (95% CI, 2.2%-4.0%), and 23.8% (95% CI, 17.0%-32.3%), respectively. The pooled proportion of VTE recurrence was 2.7% (95% CI, 1.6%-4.6%) for patients treated with direct oral anticoagulants (DOACs), 1.7% (95% CI, 0.8%-3.7%) for patients treated with low-molecular-weight heparin (LMWH), and 4.4% (95% CI, 1.5%-11.8%) for vitamin K antagonists (VKAs; P = .36). The pooled proportion was 6.3% (95% CI, 4.3%-9.1%) for cancer patients compared with 3.1% (95% CI, 2.1%-4.6%) for patients without cancer (P = .01). The pooled proportion of major bleeding for patients treated with DOACs, LMWH, and VKAs, was 2.1% (95% CI, 0.9%-5.1%), 3.2% (95% CI, 1.4%-7.2%), and 3.4% (95% CI, 1.4%-8.4%), respectively (P = .72). The pooled proportion of PTS for patients treated with DOACs, LMWH, and VKAs was 11.8% (95% CI, 6.5%-20.6%), 27.9% (95% CI, 20.9%-36.2%), and 24.5% (95% CI, 17.6%-33.1%), respectively (P = .02). CONCLUSIONS: The results from this study suggest that UEVT is associated with significant rates of PTS and VTE recurrence. Treatment with DOACs might be associated with lower PTS rates than treatment with other anticoagulants.

Long-term transformation and fate of manufactured ag nanoparticles in a simulated large scale freshwater emergent wetland.

Transformations and long-term fate of engineered nanomaterials must be measured in realistic complex natural systems to accurately assess the risks that they may pose. Here, we determine the long-term behavior of poly(vinylpyrrolidone)-coated silver nanoparticles (AgNPs) in freshwater mesocosms simulating an emergent wetland environment. AgNPs were either applied to the water column or to the terrestrial soils. The distribution of silver among water, solids, and biota, and Ag speciation in soils and sediment was determined 18 months after dosing. Most (70 wt %) of the added Ag resided in the soils and sediments, and largely remained in the compartment in which they were dosed. However, some movement between soil and sediment was observed. Movement of AgNPs from terrestrial soils to sediments was more facile than from sediments to soils, suggesting that erosion and runoff is a potential pathway for AgNPs to enter waterways. The AgNPs in terrestrial soils were transformed to Ag(2)S (~52%), whereas AgNPs in the subaquatic sediment were present as Ag(2)S (55%) and Ag-sulfhydryl compounds (27%). Despite significant sulfidation of the AgNPs, a fraction of the added Ag resided in the terrestrial plant biomass (~3 wt % for the terrestrially dosed mesocosm), and relatively high body burdens of Ag (0.5-3.3 µg Ag/g wet weight) were found in mosquito fish and chironomids in both mesocosms. Thus, Ag from the NPs remained bioavailable even after partial sulfidation and when water column total Ag concentrations are low (<0.002 mg/L).

More than the ions: the effects of silver nanoparticles on Lolium multiflorum.

Silver nanoparticles (AgNPs) are increasingly used as antimicrobial additives in consumer products and may have adverse impacts on organisms when they inadvertently enter ecosystems. This study investigated the uptake and toxicity of AgNPs to the common grass, Lolium multiflorum. We found that root and shoot Ag content increased with increasing AgNP exposures. AgNPs inhibited seedling growth. While exposed to 40 mg L(-1) GA-coated AgNPs, seedlings failed to develop root hairs, had highly vacuolated and collapsed cortical cells and broken epidermis and rootcap. In contrast, seedlings exposed to identical concentrations of AgNO(3) or supernatants of ultracentrifuged AgNP solutions showed no such abnormalities. AgNP toxicity was influenced by total NP surface area with smaller AgNPs (6 nm) more strongly affecting growth than did similar concentrations of larger (25 nm) NPs for a given mass. Cysteine (which binds Ag(+)) mitigated the effects of AgNO(3) but did not reduce the toxicity of AgNP treatments. X-ray spectro-microscopy documented silver speciation within exposed roots and suggested that silver is oxidized within plant tissues. Collectively, this study suggests that growth inhibition and cell damage can be directly attributed either to the nanoparticles themselves or to the ability of AgNPs to deliver dissolved Ag to critical biotic receptors.

Heparin modifies the immunogenicity of positively charged proteins.

The immune response in heparin-induced thrombocytopenia is initiated by and directed to large multimolecular complexes of platelet factor 4 (PF4) and heparin (H). We have previously shown that PF4:H multimolecular complexes assemble through electrostatic interactions and, once formed, are highly immunogenic in vivo. Based on these observations, we hypothesized that other positively charged proteins would exhibit similar biologic interactions with H. To test this hypothesis, we selected 2 unrelated positively charged proteins, protamine (PRT) and lysozyme, and studied H-dependent interactions using in vitro and in vivo techniques. Our studies indicate that PRT/H and lysozyme/H, like PF4/H, show H-dependent binding over a range of H concentrations and that formation of complexes occurs at distinct stoichiometric ratios. We show that protein/H complexes are capable of eliciting high-titer antigen-specific antibodies in a murine immunization model and that PRT/H antibodies occur in patients undergoing cardiopulmonary bypass surgery. Finally, our studies indicate that protein/H complexes, but not uncomplexed protein, directly activate dendritic cells in vitro leading to interleukin-12 release. Taken together, these studies indicate that H significantly alters the biophysical and biologic properties of positively charged compounds through formation of multimolecular complexes that lead to dendritic cell activation and trigger immune responses in vivo.

Comparative toxicity of C60 aggregates toward mammalian cells: role of tetrahydrofuran (THF) decomposition.

C60 fullerene is a promising material because of its unique physiochemical properties. However, previous studies have reported that colloidal aggregates of C60 (nC60) produce toxicity in fish and human cell cultures. The preparation method of nC60 raises questions as to whether the observed effects stem from fullerenes or from the organic solvents used during the preparation of the suspensions. In this paper, we set out to elucidate the mechanism by which tetrahydrofuran (THF) treatment to enhance the preparation of nC60 leads to cytotoxicity in a mouse macrophage cell line. Our results demonstrate that THF/nC60 but not fullerol or aqueous nC60 generates cellular toxicity through a pathway that involves increased intracellular flux and mitochondrial perturbation in RAW 264.7 cells. Interestingly, the supernatant of the THF/n60 suspension rather than the colloidal fullerene aggregates mimics the cytotoxic effects due to the presence of gamma-butyrolactone and formic acid. Thus, the role of nC60 in the cellular responses is likely not due to the direct effect of the nC60 material surface on the cells but is related to the conversion of THF into a toxic byproduct during preparation of the suspension.