The Incidence of Arterial Stent Fractures with Exclusion of Coronary, Aortic, and Non-arterial Settings

Background: This study aimed to review the literature regarding fracture of arterial stents, especially its relation to location of placement, clinical relevance, and type of stents. Material and methods: We searched published articles in PubMed up to February 2008 by using the terms: stent fracture or stent breakage. Results: Thirty-one articles met our inclusion and exclusion criteria. Most of the studies reported fractures in stents placed in the superficial femoral artery or popliteal arteries. The cumulative incidence of stent fractures ranged from 2% to 65%, i.e. 0.6 to 60 per 1000 person-months. Stent fractures occur more frequently in the superficial femoral artery and are common when multiple stents are deployed and overlap. Stent fractures are associated with a higher risk of in-stent restenosis and re-occlusion. Conclusion: The incidence of stent fracture, its location of placement, and type of stent used were diverse across studies. Stent fracture may cause clinical deterioration especially in the femoropopliteal segment, and it should be detected before clinical manifestation appears. Further studies with larger study population involving new type of stents for a longer follow up period are warranted.Peer reviewe

Aeolian dust supply from the Yellow River floodplain to the Pleistocene loess deposits of the Mangshan Plateau, central China : Evidence from zircon U-Pb age spectra

The thick loess-palaeosol sequences in the Mangshan Loess Plateau (MLP; central China) along the south bank of the lower reach of the Yellow River provide high-resolution records of Quaternary climate change. In addition, substantial increases in grain-size and accumulation rate have been inferred in the upper part of the loess sequence, above palaeosol layer S2. This study investigates the sources of the long-term dust supply to the MLP and explores the mechanism behind the sudden increase in sediment delivery and coarsening of the loess deposits since S2 (similar to 240 ka) by using end member modelling of the loess grain-size dataset and single-grain zircon U-Pb dating. Our results indicate that the lower Yellow River floodplain, directly north of the MLP, served as a major dust supply for the plateau at least since the deposition of loess unit L9 and indirectly suggest that the integration of the Yellow River and the disappearance of the Sanmen palaeolake took place before L9 (similar to 900 ka). The sudden change in sedi-mentology of the Mangshan sequence above palaeosol unit S2 may result from an increased fluvial sediment flux being transported to the lower reaches of the Yellow River because of tectonic movements (initiated) in the Weihe Basin around 240 ka. Furthermore, sediment coarsening can be explained by the gradual southward migration of the lower Yellow River floodplain towards the MLP since the deposition of palaeosol S2. The migration is evidenced by the formation of an impressive scarp, and is likely caused by tectonic tilting of the floodplain area. (C) 2018 Elsevier Ltd. All rights reserved.Peer reviewe

HIV Evolution in Early Infection: Selection Pressures, Patterns of Insertion and Deletion, and the Impact of APOBEC

The pattern of viral diversification in newly infected individuals provides information about the host environment and immune responses typically experienced by the newly transmitted virus. For example, sites that tend to evolve rapidly across multiple early-infection patients could be involved in enabling escape from common early immune responses, could represent adaptation for rapid growth in a newly infected host, or could represent reversion from less fit forms of the virus that were selected for immune escape in previous hosts. Here we investigated the diversification of HIV-1 env coding sequences in 81 very early B subtype infections previously shown to have resulted from transmission or expansion of single viruses (n = 78) or two closely related viruses (n = 3). In these cases, the sequence of the infecting virus can be estimated accurately, enabling inference of both the direction of substitutions as well as distinction between insertion and deletion events. By integrating information across multiple acutely infected hosts, we find evidence of adaptive evolution of HIV-1 env and identify a subset of codon sites that diversified more rapidly than can be explained by a model of neutral evolution. Of 24 such rapidly diversifying sites, 14 were either i) clustered and embedded in CTL epitopes that were verified experimentally or predicted based on the individual's HLA or ii) in a nucleotide context indicative of APOBEC-mediated G-to-A substitutions, despite having excluded heavily hypermutated sequences prior to the analysis. In several cases, a rapidly evolving site was embedded both in an APOBEC motif and in a CTL epitope, suggesting that APOBEC may facilitate early immune escape. Ten rapidly diversifying sites could not be explained by CTL escape or APOBEC hypermutation, including the most frequently mutated site, in the fusion peptide of gp41. We also examined the distribution, extent, and sequence context of insertions and deletions, and we provide evidence that the length variation seen in hypervariable loop regions of the envelope glycoprotein is a consequence of selection and not of mutational hotspots. Our results provide a detailed view of the process of diversification of HIV-1 following transmission, highlighting the role of CTL escape and hypermutation in shaping viral evolution during the establishment of new infections

Neutralization of cholera toxin by rat bile secretory IgA antibodies.

IgA-antibody (AB) activities have been elicited in rat bile against several antigens such as bacteria, erythrocytes, tumour cells, haptens and proteins (Lemaître-Coelho, Jackson & Vaerman, 1978; Hall et al., 1979; Montgomery, Lemaître-Coelho & Vaerman, 1980; Peppard et al., 1982). However, their biological significance, except for plasma clearance of immune complexes (Peppard et al., 1982) and bacterial agglutination, remains conjectural, despite their possible major contribution to rat intestinal immunity. The importance of local intestinal immunity in protection against cholera is today widely admitted (Jertborn, Svennerholm & Holmgren, 1984). Intraintestinally given cholera toxin (CT) is a potent immunogen in rats whose intestinal mucosa then harbours numerous anti-CT IgA plasma cells (Pierce, 1978). Since bile IgA in rats is largely, but not entirely, derived from intestinal synthesis (Vaerman, Lemaître-Coelho & Jackson, 1978; Manning et al., 1984), rats intestinally immunized with CT could display high levels of anti-CT IgA AB in their bile, and these AB might neutralize CT in the biologically relevant intestinal loop assay (Lange & Holmgren, 1978)

Chemotactic properties of rat immunoglobulins and immune complexes.

The effect of rat immunoglobulins and immune complexes on the locomotor function of rat polymorphonuclear leukocytes (PMN) was investigated in vitro. Rat immunoglobulin G1 (IgG1), IgG2a, IgG2b, and IgA monoclonal antibodies specific for the dinitrophenyl hapten were used. Both monomeric and polymeric IgA showed chemotactic activity in a dose-dependent manner. IgG1 and IgG2b also induced a dose-dependent locomotor response of PMN, but the nature of the induced migration was chemokinetic (enhancing random migration). IgG2a was chemotactic and induced maximal migration at a relatively low concentration. IgG1- and IgG2b-immune complexes induced stronger migration than antibody alone; however, IgA- and IgG2a-immune complexes did not. IgA was shown to modify the chemotactic movement of PMN induced by N-formylmethionyl-leucyl-phenylalanine (FMLP). In the presence of both IgA and FMLP in the lower chamber, the migration towards suboptimal concentrations of FMLP was enhanced. By contrast, IgA in the upper chamber decreased migration towards the optimal or higher concentrations of FMLP. These findings suggest that IgA may work synergistically with luminal chemoattractants to mobilize PMN to the locus of infection on the mucosal surface. In addition, the intense activity of IgG2a alone and IgG1- or IgG2b-immune complexes in inducing PMN migration may play an important role in inflammatory processes. The data indicate that immunoglobulins have a direct effect on PMN mobility

'Do (not) go to vote!' media provocation explained

This article conceptualizes media provocation, a common but understudied practice of mediatized protest and resistance, marketing or (self-)promotion and awareness raising. It is defined as a mediated act that questions or contravenes norms, values, laws, rules and symbolic power, thereby intentionally running counter to the normal horizon of expectations in a certain situation or context. As such, media provocation can have a major impact on public debate, politics and the course of events. In this article, the key elements of media provocation are initially examined and subsequently illustrated by drawing on a case study on Stijn Meuris, a Belgian rock artist and television personality. In 2010, he announced his refusal to vote in the next elections, although it is mandatory in Belgium for all adults to vote. The findings of this case study demonstrate the contingency of the component ‘intentionality’ in the definition of media provocation