37 resultados para Sequential fusion
Resumo:
The most common form of neutrophil death, under both physiological and inflammatory conditions, is apoptosis. In this study, we report a novel form of programmed necrotic cell death, associated with cytoplasmic organelle fusion events, that occurs in neutrophils exposed to GM-CSF and other inflammatory cytokines upon ligation of CD44. Strikingly, this type of neutrophil death requires PI3K activation, a signaling event usually involved in cellular survival pathways. In the death pathway reported in this study, PI3K is required for the generation of reactive oxygen species, which somehow trigger the generation of large cytoplasmic vacuoles, generated by the fusion of CD44-containing endosomes with autophagosomes and secondary, but not primary, granules. Neutrophils demonstrating vacuolization undergo rapid cell death that depends on receptor-interacting protein 1 kinase activity and papain family protease(s), but not caspases, that are most likely activated and released, respectively, during or as a consequence of organelle fusion. Vacuolized neutrophils are present in infectious and autoimmune diseases under in vivo conditions. Moreover, isolated neutrophils from such patients are highly sensitive toward CD44-mediated PI3K activation, reactive oxygen species production, and cell death, suggesting that the newly described autophagy-related form of programmed neutrophil necrosis plays an important role in inflammatory responses.
Resumo:
Microsurgical suturing is the standard for cerebral bypass surgery, a technique where temporary occlusion is usually necessary. Non-occlusive techniques such as excimer laser-assisted non-occlusive anastomosis (ELANA) have certainly widened the spectrum of treatment of complex cerebrovascular situations, such as giant cerebral aneurysms, that were otherwise non-treatable. Nevertheless, the reduction of surgical risks while widening the spectrum of indications, such as a prophylactic cerebral bypass, is still a main aim, that we would like to pursue with our sutureless tissue fusion research. The primary concern in sutureless tissue fusion- and especially in tissue fusion of cerebral vessels- is the lack of reproducibility, often caused by variations in the thermal damage of the vessel. This has prevented this novel fusion technique from being applicable in daily surgical use. In this overview, we present three ways to further improve the laser tissue soldering technique.In the first section entitled "Laser Tissue Soldering Using a Biodegradable Polymer," a porous polymer scaffold doped with albumin (BSA) and indocyanine green (ICG) is presented, leading to strong and reproducible tensile strengths in tissue soldering. Histologies and future developments are discussed.In the section "Numerical Simulation for Improvement of Laser Tissue Soldering," a powerful theoretical simulation model is used to calculate temperature distribution during soldering. The goal of this research is to have a tool in hand that allows us to determine laser irradiation parameters that guarantee strong vessel fusion without thermally damaging the inner structures such as the intima and endothelium.In a third section, "Nanoparticles in Laser Tissue Soldering," we demonstrate that nanoparticles can be used to produce a stable and well-defined spatial absorption profile in the scaffold, which is an important step towards increasing the reproducibility. The risks of implanting nanoparticles into a biodegradable scaffold are discussed.Step by step, these developments in sutureless tissue fusion have improved the tensile strength and the reproducibility, and are constantly evolving towards a clinically applicable anastomosis technique.
Resumo:
Posterior lumbar fusion is a frequently performed procedure in spinal surgery. High percentages of good and excellent results are indicated by physicians. On the other hand patient-based outcomes are reported. Little is known about the correlations of these two assessment types. We aimed at their comparison. The analysis included 1013 patients with degenerative spinal disease or spondylolisthesis from an international spine registry, treated with posterior lumbar fusion. All patients were pre/postop assessed by physician-based McNab criteria (‘excellent’, ‘good’, ‘fair’, ‘poor’). Of these patients, 210 (mean age 61 years; 57% females) were in addition assessed by patient-based Oswestry Disability Index (ODI). The remaining 803 patients (mean age 59 years; 56% females) were assessed by patient-based Core Outcome Measure Index (COMI), including Visual Analogue Scale (VAS) for back and leg pain as well as verbal self-rating (‘helped a lot’, ‘helped’, ‘helped only little’, ‘didn’t help’, ‘made things worse’). McNab criteria were compared to the Minimal Clinically Important Difference (MCID) in ODI (12.8), in VAS back (1.2) and leg pain (1.6). We investigated the correlations between McNab criteria and these patient-based outcomes. In the ‘excellent’ group as rated by physicians, the proposed MCID was reached in 83% of patients for ODI, in 69% for VAS back and in 83% for VAS leg pain. All patients said the treatment had ‘helped’ or ‘helped a lot’. In the ‘good’ group 56% (ODI), 66% (back pain) and 86% (leg pain) reached the MCID. 96% of patients perceived the treatment as positive. In the ‘fair’ group 37% (ODI), 55% (back pain) and 63% (leg pain) reached the MCID. 49% had positive treatment considerations. The ‘poor’ group revealed 30% (ODI), 35% (back pain) and 44% (leg pain) of patients with reached MCID. Only 15% rated the treatment as positive. The Spearman correlation coefficients between McNab criteria on the one hand and ODI, back and leg pain as well as patients’ verbal self-rating on the other hand were 0.57, 0.37, 0.36 and 0.46 respectively. The comparison of physician and patient-based outcomes showed the highest correlations between McNab criteria and ODI, somewhat weaker correlations with patients’ self-rating and the weakest correlations with back and leg pain. Based on these findings, physicians’ evaluation of patient outcomes can be considered a valuable part of patient assessment, corresponding very well with patients’ perceptions of success or failure of spinal surgery.
Resumo:
Aggregation of the high-affinity IgE receptor (FcεRI) with the low-affinity IgG receptor (FcγRIIb) on basophils or mast cells has been shown to inhibit allergen-induced cell degranulation. Molecules cross-linking these two receptors might therefore be of interest for the treatment of allergic disorders. Here, we demonstrate the generation of a novel bispecific fusion protein efficiently aggregating FcεRI-bound IgE with FcγRIIb on the surface of basophils to prevent pro-inflammatory mediator release.
Resumo:
Biolimus-eluting stents (BESs) with a biodegradable polymer in abluminal coating achieve more complete coverage at 9 months compared with sirolimus-eluting stents (SESs) with a durable polymer, as assessed by optical coherence tomography (OCT). Whether this advantage persists or augments after complete resorption of the polymer (>12 months) is unknown.
Resumo:
The vascular tissue reaction to acute incomplete stent apposition (ISA) is not well known. The aim of this study was to characterize the vascular response to acute ISA in vivo and to look for predictors of incomplete healing.
Resumo:
Four-corner fusion is a proven treatment option for degenerative arthritis of the wrist (SLAC/SNAC); however, in some cases, non-union occurs. The purpose of this study was to evaluate the clinical outcome of rearthrodesis in cases of non-union following four-corner fusion. Furthermore, the goal was to identify the cause of non-union and the location of pseudarthrosis within the fusion.
Resumo:
Based on the structural similarity of viral fusion proteins within the family Paramyxoviridae, we tested recently described and newly synthesized acetanilide derivatives for their capacity to inhibit measles virus (MV)-, canine distemper virus (CDV)- and Nipah virus (NiV)-induced membrane fusion. We found that N-(3-cyanophenyl)-2-phenylacetamide (compound 1) has a high capacity to inhibit MV- and CDV-induced (IC(50) muM), but not NiV-induced, membrane fusion. This compound is of outstanding interest because it can be easily synthesized and its cytotoxicity is low [50 % cytotoxic concentration (CC(50)) >/= 300 muM], leading to a CC(50)/IC(50) ratio of approximately 100. In addition, primary human peripheral blood lymphocytes and primary dog brain cell cultures (DBC) also tolerate high concentrations of compound 1. Infection of human PBMC with recombinant wild-type MV is inhibited by an IC(50) of approximately 20 muM. The cell-to-cell spread of recombinant wild-type CDV in persistently infected DBC can be nearly completely inhibited by compound 1 at 50 muM, indicating that the virus spread between brain cells is dependent on the activity of the viral fusion protein. Our findings demonstrate that this compound is a most applicable inhibitor of morbillivirus-induced membrane fusion in tissue culture experiments including highly sensitive primary cells.
Resumo:
To demonstrate the feasibility and potential usefulness of an offline fusion of matched optical coherence tomography (OCT) and intravascular ultrasound (IVUS)/virtual histology (IVUS-VH) images.
Resumo:
Early warning of future hypoglycemic and hyperglycemic events can improve the safety of type 1 diabetes mellitus (T1DM) patients. The aim of this study is to design and evaluate a hypoglycemia/hyperglycemia early warning system (EWS) for T1DM patients under sensor-augmented pump (SAP) therapy.