Background
Chemokines play a critical role in orchestrating the distribution and trafficking of neutrophils in homeostasis and disease.
Results
The CXCR4/CXCL12 chemokine axis has been identified as ...a central regulator of these processes.
Conclusion
In this review, we focus on the role of CXCR4/CXCL12 chemokine axis in regulating neutrophil release from the bone marrow and the trafficking of senescent neutrophils back to the bone marrow for clearance under homeostasis and disease. We also discuss the role of CXCR4 in fine‐tuning neutrophil responses in the context of inflammation.
Translation of evidence-based interventions into hospital systems can provide immediate and substantial benefits to patient care and outcomes, but successful implementation is often not achieved. ...Existing literature describes a range of barriers and facilitators to the implementation process. This systematic review identifies and explores relationships between these barriers and facilitators to highlight key domains that need to be addressed by researchers and clinicians seeking to implement hospital-based, patient-focused interventions.
We searched MEDLINE, PsychInfo, Embase, Web of Science, and CINAHL using search terms focused specifically on barriers and facilitators to the implementation of patient-focused interventions in hospital settings. To be eligible, papers needed to have collected formal data (qualitative or quantitative) that specifically assessed the implementation process, as experienced by the staff involved.
Of 4239 papers initially retrieved, 43 papers met inclusion criteria. Staff-identified barriers and facilitators to implementation were grouped into three main domains: system, staff, and intervention. Bi-directional associations were evident between these domains, with the strongest links evident between staff and intervention.
Researchers and health professionals engaged in designing patient-focused interventions need to consider barriers and facilitators across all three identified domains to increase the likelihood of implementation success. The interrelationships between domains are also crucial, as resources in one area can be leveraged to address barriers in others. These findings emphasize the importance of careful intervention design and pre-implementation planning in response to the specific system and staff context in order to increase likelihood of effective and sustainable implementation.
This review was registered on the PROSPERO database: CRD42017057554 in February 2017.
Neutrophils, an essential component of the innate immune system, are produced at a rate 10(11) cells/day and are consequently the most abundant leukocyte in the blood. These granulocytes have a ...relatively short half-life (6-8 h) in the blood, and as a result of the cytotoxic nature of their contents, it is critical that there are mechanisms in place for the efficient clearance of these effete cells from the circulation. Although macrophages of the reticuloendothelial system are positioned ideally to recognize and phagocytose apoptotic neutrophils in the circulation, this review challenges the current dogma that neutrophils are cleared primarily in the liver and spleen, presenting the evidence that the bone marrow is also an important site of neutrophil clearance under homeostatic conditions. Furthermore, a role for the CXCL12/CXCR4 chemokine axis in the trafficking of senescent neutrophils back to the bone marrow for clearance is described.
ABSTRACT Two entwined problems have remained unresolved since pulsars were discovered nearly 50 yr ago: the orientation of their polarized emission relative to the emitting magnetic field and the ...direction of putative supernova "kicks" relative to their rotation axes. The rotational orientation of most pulsars can be inferred only from the ("fiducial") polarization angle of their radiation, when their beam points directly at the Earth and the emitting polar fluxtube field is to the rotation axis. Earlier studies have been unrevealing owing to the admixture of different types of radiation (core and conal, two polarization modes), producing both or alignments. In this paper we analyze some 50 pulsars having three characteristics: core radiation beams, reliable absolute polarimetry, and accurate proper motions (PMs). The "fiducial" polarization angle of the core emission, we then find, is usually oriented to the PM direction on the sky. The primary core emission is polarized to the projected magnetic field in Vela and other pulsars where X-ray imaging reveals the orientation. This shows that the PMs usually lie to the rotation axes on the sky. Two key physical consequences then follow: first, to the extent that supernova "kicks" are responsible for pulsar PMs, they are mostly to the rotation axis; and, second, most pulsar radiation is heavily processed by the magnetospheric plasma such that the lowest altitude "parent" core emission is polarized to the emitting field, propagating as the extraordinary (X) mode.
The bone marrow is the site of neutrophil production, a process that is regulated by the cytokine granulocyte colony-stimulating factor (G-CSF). Mature neutrophils are continually released into the ...circulation, with an estimated 10 ¹¹ neutrophils exiting the bone marrow daily under basal conditions. These leucocytes have a short half-life in the blood of ~6·5 hr, and are subsequently destroyed in the spleen, liver and indeed the bone marrow itself. Additionally, mature neutrophils are retained in the bone marrow by the stromal cell-derived factor (SDF-1α)/chemokine (C-X-C motif) receptor 4 (CXCR4) chemokine axis and form the bone marrow reserve. Following infection or inflammatory insult, neutrophil release from the bone marrow reserve is substantially elevated and this process is mediated by the co-ordinated actions of cytokines and chemokines. In this review we discuss the factors and molecular mechanisms regulating the neutrophil mobilization and consider the mechanisms and functional significance of neutrophil clearance via the bone marrow.
Compact and portable methods for identification of explosives are increasingly needed for both civilian and military applications. A portable optoelectronic nose for the gas-phase identification of ...explosive materials is described that uses a highly cross-reactive colorimetric sensor array and a handheld scanner. The array probes a wide range of chemical reactivities using 40 chemically responsive colorimetric indicators, including pH sensors, metal-dye salts, redox-sensitive chromogenic compounds, solvatochromic dyes, and other chromogenic indicators. Sixteen separate analytes including common explosives, homemade explosives, and characteristic explosive components were differentiated into fourteen separate classes with a classification error rate of <1%. Portable colorimetric array sensing could represent an important, complementary part of the toolbox used in practical applications of explosives detection and identification.
Abstract Background The applications for rapid prototyping have expanded dramatically over the last 20 y. In recent years, additive manufacturing has been intensely investigated for surgical ...implants, tissue scaffolds, and organs. There is, however, scant literature to date that has investigated the viability of three-dimensional (3D) printing of surgical instruments. Materials and methods Using a fused deposition modeling printer, an Army/Navy surgical retractor was replicated from polylactic acid (PLA) filament. The retractor was sterilized using standard Food and Drug Administration approved glutaraldehyde protocols, tested for bacteria by polymerase chain reaction, and stressed until fracture to determine if the printed instrument could tolerate force beyond the demands of an operating room (OR). Results Printing required roughly 90 min. The instrument tolerated 13.6 kg of tangential force before failure, both before and after exposure to the sterilant. Freshly extruded PLA from the printer was sterile and produced no polymerase chain reaction product. Each instrument weighed 16 g and required only $0.46 of PLA. Conclusions Our estimates place the cost per unit of a 3D-printed retractor to be roughly 1/10th the cost of a stainless steel instrument. The PLA Army/Navy retractor is strong enough for the demands of the OR. Freshly extruded PLA in a clean environment, such as an OR, would produce a sterile ready-to-use instrument. Because of the unprecedented accessibility of 3D printing technology world wide and the cost efficiency of these instruments, there are far reaching implications for surgery in some underserved and less developed parts of the world.
Smoking cessation reduces the risk of death, improves recovery, and reduces the risk of hospital readmission. Evidence and policy support hospital admission as an ideal time to deliver ...smoking‐cessation interventions. However, this is not well implemented in practice. In this systematic review, the authors summarize the literature on smoking‐cessation implementation strategies and evaluate their success to guide the implementation of best‐practice smoking interventions into hospital settings. The CINAHL Complete, Embase, MEDLINE Complete, and PsycInfo databases were searched using terms associated with the following topics: smoking cessation, hospitals, and implementation. In total, 14,287 original records were identified and screened, resulting in 63 eligible articles from 56 studies. Data were extracted on the study characteristics, implementation strategies, and implementation outcomes. Implementation outcomes were guided by Proctor and colleagues' framework and included acceptability, adoption, appropriateness, cost, feasibility, fidelity, penetration, and sustainability. The findings demonstrate that studies predominantly focused on the training of staff to achieve implementation. Brief implementation approaches using a small number of implementation strategies were less successful and poorly sustained compared with well resourced and multicomponent approaches. Although brief implementation approaches may be viewed as advantageous because they are less resource‐intensive, their capacity to change practice in a sustained way lacks evidence. Attempts to change clinician behavior or introduce new models of care are challenging in a short time frame, and implementation efforts should be designed for long‐term success. There is a need to embrace strategic, well planned implementation approaches to embed smoking‐cessation interventions into hospitals and to reap and sustain the benefits for people who smoke.
Neutrophils are the most abundant circulating leukocyte and play a fundamental role in the innate immune response. Patients with neutropenia, leukocyte adhesion deficiency syndrome or chronic ...granulomatous disease are particularly prone to bacterial and fungal infection. However, the highly destructive capacity of these cells also increases the potential for neutrophil damage to healthy tissues, as seen in a number of inflammatory diseases such as rheumatoid arthritis and chronic obstructive pulmonary disease. The homeostatic control of circulating neutrophil levels is thus critical, as an imbalance can result in overwhelming infection or inappropriate inflammatory states. Neutrophil homeostasis is maintained by a fine balance between granulopoiesis in the bone marrow, retention in and release from the bone marrow and clearance and destruction. This review discusses the molecular mechanisms regulating neutrophil mobilization from the bone marrow, with emphasis on the antagonistic roles of the CXCR4 (C-X-C motif receptor 4)/CXCL12 (C-X-C motif ligand 12) and CXCR2/ELR+ (Glu-Leu-Arg) CXC chemokine signaling axes in the bone marrow. A role for the CXCL12/CXCR4 chemokine axis in the trafficking of senescent neutrophils back to the bone marrow for clearance, along with the role of bone marrow macrophages and the molecules that mediate neutrophil clearance by bone marrow macrophages, is also discussed.
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