122 research outputs found

    Presence of Borrelia burgdorferi sensu lato antibodies in the serum of patients with abdominal aortic aneurysms

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    Infectious agents are likely to play a role in the pathogenesis of chronic inflammatory diseases, including abdominal aortic aneurysms (AAAs). The goal of this study was to determine if Borrelia burgdorferi sensu lato (sl), a microorganism responsible for Lyme disease, is involved in the etiology of AAAs. The presence of serum antibodies against B. burgdorferi sl was measured with enzyme-linked immunosorbent assay (ELISA) and confirmed by Western blotting in 96 AAA and 108 peripheral artery disease (PAD) patients. Polymerase chain reaction (PCR) was used for the detection of Borrelia-specific DNA in the aneurysm wall. Among AAA patients 34% and among PAD patients 16% were seropositive for B. burgdorferi sl antibodies (Fisher’s exact test, p = 0.003; odds ratio [OR] 2.79; 95% confidence interval [CI] 1.37–5.85). In the German general population, 3–17% are seropositive for Borrelia antibodies. No Borrelia DNA was detected in the aneurysm wall. Our findings suggest a relationship between AAAs and B. burgdorferi sl. We hypothesize that the underlying mechanism for B. burgdorferi sl in AAA formation is similar to that by the spirochete Treponema pallidum; alternatively, AAAs could develop due to induced autoimmunity via molecular mimicry due to similarities between some of the B. burgdorferi sl proteins and aortic proteins

    Steering cell migration by alternating blebs and actin-rich protrusions

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    Background High directional persistence is often assumed to enhance the efficiency of chemotactic migration. Yet, cells in vivo usually display meandering trajectories with relatively low directional persistence, and the control and function of directional persistence during cell migration in three-dimensional environments are poorly understood. Results Here, we use mesendoderm progenitors migrating during zebrafish gastrulation as a model system to investigate the control of directional persistence during migration in vivo. We show that progenitor cells alternate persistent run phases with tumble phases that result in cell reorientation. Runs are characterized by the formation of directed actin-rich protrusions and tumbles by enhanced blebbing. Increasing the proportion of actin-rich protrusions or blebs leads to longer or shorter run phases, respectively. Importantly, both reducing and increasing run phases result in larger spatial dispersion of the cells, indicative of reduced migration precision. A physical model quantitatively recapitulating the migratory behavior of mesendoderm progenitors indicates that the ratio of tumbling to run times, and thus the specific degree of directional persistence of migration, are critical for optimizing migration precision. Conclusions Together, our experiments and model provide mechanistic insight into the control of migration directionality for cells moving in three-dimensional environments that combine different protrusion types, whereby the proportion of blebs to actin-rich protrusions determines the directional persistence and precision of movement by regulating the ratio of tumbling to run times

    Endocytic reawakening of motility in jammed epithelia

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    Dynamics of epithelial monolayers has recently been interpreted in terms of a jamming or rigidity transition. How cells control such phase transitions is, however, unknown. Here we show that RAB5A, a key endocytic protein, is sufficient to induce large-scale, coordinated motility over tens of cells, and ballistic motion in otherwise kinetically arrested monolayers. This is linked to increased traction forces and to the extension of cell protrusions, which align with local velocity. Molecularly, impairing endocytosis, macropinocytosis or increasing fluid efflux abrogates RAB5A-induced collective motility. A simple model based on mechanical junctional tension and an active cell reorientation mechanism for the velocity of self-propelled cells identifies regimes of monolayer dynamics that explain endocytic reawakening of locomotion in terms of a combination of large-scale directed migration and local unjamming. These changes in multicellular dynamics enable collectives to migrate under physical constraints and may be exploited by tumours for interstitial dissemination

    Diversified actin protrusions promote environmental exploration but are dispensable for locomotion of leukocytes

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    Most migrating cells extrude their front by the force of actin polymerization. Polymerization requires an initial nucleation step, which is mediated by factors establishing either parallel filaments in the case of filopodia or branched filaments that form the branched lamellipodial network. Branches are considered essential for regular cell motility and are initiated by the Arp2/3 complex, which in turn is activated by nucleation-promoting factors of the WASP and WAVE families. Here we employed rapid amoeboid crawling leukocytes and found that deletion of the WAVE complex eliminated actin branching and thus lamellipodia formation. The cells were left with parallel filaments at the leading edge, which translated, depending on the differentiation status of the cell, into a unipolar pointed cell shape or cells with multiple filopodia. Remarkably, unipolar cells migrated with increased speed and enormous directional persistence, while they were unable to turn towards chemotactic gradients. Cells with multiple filopodia retained chemotactic activity but their migration was progressively impaired with increasing geometrical complexity of the extracellular environment. These findings establish that diversified leading edge protrusions serve as explorative structures while they slow down actual locomotion

    Impact of a tailored program on the implementation of evidence-based recommendations for multimorbid patients with polypharmacy in primary care practices — results of a cluster-randomized controlled trial

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    Background: Multimorbid patients receiving polypharmacy represent a growing population at high risk for negative health outcomes. Tailoring is an approach of systematic intervention development taking account of previously identified determinants of practice. The aim of this study was to assess the effect of a tailored program to improve the implementation of three important processes of care for this patient group: (a) structured medication counseling including brown bag reviews, (b) the use of medication lists, and (c) structured medication reviews to reduce potentially inappropriate medication. Methods: We conducted a cluster-randomized controlled trial with a follow-up time of 9 months. Participants were general practitioners (GPs) organized in quality circles and participating in a GP-centered care contract of a German health insurance. Patients aged >50 years, suffering from at least 3 chronic diseases, receiving more than 4 drugs, and being at high risk for medication-related events according to the assessment of the treating GP were enrolled. The tailored program consisted of a workshop for GPs and health care assistants, educational materials and reminders for patients, and the elaboration of implementation action plans. The primary outcome was the change in the degree of implementation between baseline and follow-up, measured by a summary score of 10 indicators. The indicators were based on structured surveys with patients and GPs. Results: We analyzed the data of 21 GPs (10 - intervention group, 11 - control group) and 273 patients (130 - intervention group, 143 - control group). The increase in the degree of implementation was 4.2 percentage points (95% confidence interval: −0.3, 8.6) higher in the intervention group compared to the control group (p = 0.1). Two of the 10 indicators were significantly improved in the intervention group: medication counseling (p = 0.017) and brown bag review (p = 0.012). Secondary outcomes showed an effect on patients’ self-reported use of medication lists when buying drugs in the pharmacy (p = 0.03). Conclusions: The tailored program may improve implementation of medication counseling and brown bag review whereas the use of medication lists and medication reviews did not improve. No effect of the tailored program on the combined primary outcome could be substantiated. Due to limitations of the study, results have to be interpreted carefully. The factors facilitating and hindering successful implementation will be examined in a comprehensive process evaluation. Trial registration number ISRCTN34664024, assigned 14/08/201

    Adenovirus-mediated and targeted expression of the sodium-iodide symporter permits in vivo radioiodide imaging and therapy of pancreatic tumors

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    Pancreatic cancer is the fourth leading cause of cancer death in the United States. It is highly aggressive with no uniformly effective chemotherapy available for metastatic disease. The sodium–iodide symporter (NIS) is a transmembrane protein responsible for uptake of iodide into cells. The presence of NIS in thyroid cells permits diagnostic imaging and therapy of thyroid tumors, using radioiodide. Previous studies from this laboratory reported mucin-1 (MUC1)-driven expression of NIS in cancer cells. MUC1 overexpression has also been reported in 90% of pancreatic tumors. In this study Ad5/MUC1/NIS was used to infect pancreatic cancer cells both in vitro and in vivo, to investigate the potential for radioiodide imaging and ablation of this disease. In vitro studies revealed a 43-fold increase in iodide uptake in NIS-transduced cells compared with controls. In vivo imaging revealed effective iodide uptake and retention at the site of NIS-transduced tumors, with optimal uptake (13% of injected dose) observed 5 hr after iodide administration. Intravenous delivery was performed to investigate potential hepatotoxicity of the construct in the event of virus leakage. Intravenous injection of Ad5/CMV/NIS resulted in robust iodide uptake throughout mouse liver, whereas no uptake was detected in the liver of animals given Ad5/MUC1/NIS intravenously. Administration of therapeutic doses of 131I resulted in significant regression of NIS-transduced tumors, with a mean 50% reduction in volume within 10 weeks of therapy (p < 0.0001). The ability to target NIS expression to pancreatic cancer, which has such limited treatment options, may be highly beneficial and warrants further investigation.Funding for this work was received from the Prospect Creek Foundation, a Mayo Foundation Prostate Cancer SPORE grant (CA91956), the Mayo Breast Cancer Program, and the Molecular Medicine Program of the Mayo Clinic College of Medicine.peer-reviewe

    Optimale Therapie der verschlussbedrohten AV-Fistel

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