High-mobility group box 1, an endogenous ligand of toll-like receptors 2 and 4, induces astroglial inflammation via nuclear factor kappa B pathway

Background: Neuroinflammation has a definitive role in neurodegenerative diseases, such as Parkinson’s and Alzheimer’s disease. In addition to its pathoge- nic ligands, toll-like receptors (TLRs) can be activated by damaged endogenous molecules that induce inflammatory signalling pathways such as high-mobility group box 1 protein (HMGB1).  Materials and methods: Using an ex-vivo rat optic nerve (RON) model, we sought to determine the effects of lipopolysaccharides (LPS; TLR4 agonist), zymosan (TLR2 agonist) or HMGB1 — with or without TLR2/4 antagonists, on the expression of glial fibrillary acidic protein (GFAP) and nuclear factor kappa B (NF-ҡβ) for signalling pathway and astrocyte reactivity, using double immunohistochemistry; as well as on the modulation of the neurotoxicity. HMGB1-treated RON had significantly higher expression and co-localisation of GFAP and NF-ҡβ as compared to the un- treated control, which was a similar result to those treated with LPS and zymosan.  Results: Moreover, the HMGB1-induced inflammation was blocked by TLR2/4 antagonists (p = 0.05). However, the HMGB1-induced cell death was unblocked by TLR antagonists. Overall, HMGB1 endogenously mediates the signalling me- chanisms of neuroinflammation through TLR2/4.  Conclusions: Whereas, the neuronal death mechanism resulting from HMGB1 could be caused by a different signalling pathway. Gaining an understanding of these mechanisms may help researchers discover new therapeutic targets for neurodegenerative diseases.

Monocyte Subpopulations from Pre-Eclamptic Patients Are Abnormally Skewed and Exhibit Exaggerated Responses to Toll-Like Receptor Ligands

The leading cause of pregnancy-associated mortality and morbidity is pre-eclampsia (PE). Although information regarding the etiology of this disease is scant, its pathophysiology is characterized by abnormal placentation, endothelial dysfunction as well as an exaggerated inflammatory response. Clinical evidence also indicates that the abundance of many immune cells at the feto-maternal interface and in the circulation of PE patients is abnormal, when compared with normal pregnant (NP) controls. In addition, the phenotype and function of some of these cells is altered. To further characterize the systemic effects of PE on circulating cells, we analyzed monocytic subpopulations in NP and PE patients by flow cytometry. We found that non-classical CD14lowCD16+ monocytes are significantly increased in women with PE and they display irregular expression of several chemokine receptors and antigen presentation molecules. The most striking phenotypic difference among the cell surface molecules was the marked upregulation of TLR4 expression, where both CD14highCD16+ and CD14lowCD16+ monocytes demonstrated higher levels than their NP counterparts. Stimulation of PE monocytes with TLR ligands resulted in profound secretion of various cytokines in comparison with NP controls. These data suggest that PE monocytes are hyper-responsive to TLR ligands and this may contribute to exacerbation of the disease

A systematic review of the psychometric properties of self-report research utilization measures used in healthcare

<p>Abstract</p> <p>Background</p> <p>In healthcare, a gap exists between what is known from research and what is practiced. Understanding this gap depends upon our ability to robustly measure research utilization.</p> <p>Objectives</p> <p>The objectives of this systematic review were: to identify self-report measures of research utilization used in healthcare, and to assess the psychometric properties (acceptability, reliability, and validity) of these measures.</p> <p>Methods</p> <p>We conducted a systematic review of literature reporting use or development of self-report research utilization measures. Our search included: multiple databases, ancestry searches, and a hand search. Acceptability was assessed by examining time to complete the measure and missing data rates. Our approach to reliability and validity assessment followed that outlined in the <it>Standards for Educational and Psychological Testing</it>.</p> <p>Results</p> <p>Of 42,770 titles screened, 97 original studies (108 articles) were included in this review. The 97 studies reported on the use or development of 60 unique self-report research utilization measures. Seven of the measures were assessed in more than one study. Study samples consisted of healthcare providers (92 studies) and healthcare decision makers (5 studies). No studies reported data on acceptability of the measures. Reliability was reported in 32 (33%) of the studies, representing 13 of the 60 measures. Internal consistency (Cronbach's Alpha) reliability was reported in 31 studies; values exceeded 0.70 in 29 studies. Test-retest reliability was reported in 3 studies with Pearson's <it>r </it>coefficients > 0.80. No validity information was reported for 12 of the 60 measures. The remaining 48 measures were classified into a three-level validity hierarchy according to the number of validity sources reported in 50% or more of the studies using the measure. Level one measures (n = 6) reported evidence from any three (out of four possible) <it>Standards </it>validity sources (which, in the case of single item measures, was all applicable validity sources). Level two measures (n = 16) had evidence from any two validity sources, and level three measures (n = 26) from only one validity source.</p> <p>Conclusions</p> <p>This review reveals significant underdevelopment in the measurement of research utilization. Substantial methodological advances with respect to construct clarity, use of research utilization and related theory, use of measurement theory, and psychometric assessment are required. Also needed are improved reporting practices and the adoption of a more contemporary view of validity (<it>i.e.</it>, the <it>Standards</it>) in future research utilization measurement studies.</p

Fibrinogen, an endogenous ligand of Toll-like receptor 4, activates monocytes in pre-eclamptic patients

Pre-eclampsia (PE) remains the leading cause of pregnancy-associated mortality and morbidity, urging the need for a better understanding of its aetiology and pathophysiological progression. A key characteristic of PE is a systemic, exaggerated, inflammatory condition involving abnormal cytokine levels in serum, altered immune cell phenotype and Th1/Th2-type immunological imbalance. However, it is unknown how this heightened inflammatory condition manifests. We previously reported increased expression of the lipopolysaccharide receptor, Toll-like receptor 4 (TLR4), on monocytes from PE patients compared with normotensive, pregnant patients (NP). This upregulation of TLR4 on PE monocytes was accompanied by a hyper-responsiveness to bacterial TLR4 ligands. To determine whether non-microbial, endogenous TLR4 ligands also activate monocytes from PE patients, we investigated the expression of host-derived TLR4 ligands and the response of monocytes to these endogenous ligands. Plasma levels of fibrinogen – but not fibronectin or heparan sulphate – were higher in PE patients than in NP. Exposure to fibrinogen was associated with significantly increased production of inflammatory cytokines by monocytes from PE patients. Interestingly, this effect was not observed with NP monocytes. Our findings suggest that the fibrinogen-TLR4 axis might play an important role in the atypical activation of monocytes observed in PE patients that may contribute to the exaggerated inflammatory condition

Perception and Experiences of Infection Control Practices among Professional Nurses in Secondary Health Facilities in South-South Nigeria: A Qualitative Approach

Infection control practice is a fundamental operational guiding principle in the delivery of modern health care. However, there is minimal qualitative investigation into professional nurses’ perception of infection control practices and how the experiences affect compliance with recommended infection control procedures. The purpose of this study was to examine and describe professional nurses’ impressions and experiences about infection control practices. A descriptive qualitative research design was used as the research framework. In-depth Interviews (IDI) and Focus Group Discussions (FGDs) were completed with a sample of 54 nurses. The findings highlight the importance of both individual and organisational factors in determining Nurses’ compliance with recommended workplace safety practices. Four major themes emerged from the data, namely knowledge, infection surveillance, safety practices, and workplace policy. The findings indicate individual and organisational factors associated with compliance which are useful in developing strategies to facilitate long-term compliance with infection control practices among nurses

Monocytes from PE patients exhibit an amplified response to TLR ligands.

<p>Monocytes from non-pregnant (Non-P), normal pregnant (NP), and pre-eclampsia (PE) patients were isolated, seeded onto tissue culture plates, then treated with 100 ng/mL LPS or 5 µg/mL peptidoglycan (PDG) for 24 hours. Conditioned medium was collected after this time and analyzed by cytometric bead array to measure cytokine levels. <b><i>left panels:</i></b> Basal levels of cytokine production by monocytes. <b><i>right panels</i></b><i>:</i> Graphic representation of the response of monocytes to LPS and PDG. Fold change was calculated by dividing MFI values over untreated control MFI values and illustrated as mean ± SEM. Comparisons were made between NP and PE fold changes. Statistical significance was determined by Mann-Whitney <i>U</i> test (n≥5). ^†<i>p</i><0.05, ^††<i>p</i><0.01 as compared with NP.</p

NP and PE monocytes display marked phenotypic differences.

<p>PBMCs from non-pregnant (Non-P), normal pregnant (NP), and pre-eclampsia (PE) patients were stained with anti-CD14-AlexaFluor700, anti-CD16-eFluor450, anti-CCR2-PE, anti-CCR5-FITC, anti-HLA-DR-PerCP-Cy5.5, anti-TIE2-APC, anti-TLR2-FITC, and anti-TLR4-PE antibodies then analyzed by flow cytometry. Gates were placed around monocytes on FSC/SSC plots and the percentage of positive cells was calculated based off isotype controls. Values are illustrated as mean ± SEM. Statistical significance was determined by Mann-Whitney <i>U</i> test (n = 5−16). n.s. =  not significant, **<i>p</i><0.01, ***<i>p</i><0.001 as compared with Non-P; ^†<i>p</i><0.05, ^††<i>p</i><0.01, ^†††<i>p</i><0.001 as compared with NP.</p

Patient characteristics.

<p>Patient characteristics.</p

Expression of phenotypic markers on monocyte subpopulations.

<p>PBMCs from non-pregnant (Non-P), normal pregnant (NP), and pre-eclampsia (PE) patients were stained with anti-CD14-AlexaFluor700, anti-CD16-eFluor450, anti-CCR2-PE, anti-CCR5-FITC, anti-HLA-DR-PerCP-Cy5.5, anti-TIE2-APC, anti-TLR2-FITC, and anti-TLR4-PE antibodies then analyzed by flow cytometry. Gates were placed around CD14/CD16 monocyte subpopulations and median fluorescence intensity (MFI) was calculated based off isotype controls. Values are illustrated as mean ± SEM. Statistical significance was determine by Mann-Whitney <i>U</i> test (n = 7−17). *<i>p</i><0.05, **<i>p</i><0.01 as compared with Non-P; ^†<i>p</i><0.05, ^††<i>p</i><0.01 as compared with NP.</p