Trans-disciplinary research approaches: integration of fluid mechanics with cell biology

At the level of the individual molecule, outstanding discoveries leading the the 2012 Nobel Prize in Chemistry clarified G-protein coupled receptors (GPCRs) crystallographic structures and functions. Nevertheless, a large number of such receptors cooperate to ultimately determine the cell response. Henceforth, understanding their group effects becomes crucial to predict the activity of the GPCRs populating the various cell aggregates

High-intensity, unilateral resistance training of a non-paretic muscle group increases active range of motion in a severely paretic upper extremity muscle group after stroke

Limited rehabilitation strategies are available for movement restoration when paresis is too severe following stroke. Previous research has shown that high-intensity resistance training of one muscle group enhances strength of the homologous, contralateral muscle group in neurologically-intact adults. How this cross education phenomenon might be exploited to moderate severe weakness in an upper extremity muscle group after stroke is not well understood. The primary aim of this study was to examine adaptations in force-generating capacity of severely paretic wrist extensors resulting from high-intensity, dynamic contractions of the non-paretic wrist extensors. A secondary, exploratory aim was to probe neural adaptations in a subset of participants from each sample using a single-pulse, transcranial magnetic stimulation protocol. Separate samples of neurologically-intact controls (n=7) and individuals > 4 months post stroke (n=6) underwent 16 sessions of training. Following training, one-repetition maximum of the untrained wrist extensors in the control group and active range of motion of the untrained, paretic wrist extensors in the stroke group were significantly increased. No changes in corticospinal excitability, intracortical inhibition or interhemispheric inhibition were observed in control participants. Both stroke participants who underwent TMS testing, however, exhibited increased voluntary muscle activation following the intervention. In addition, motor-evoked potentials that were unobtainable prior to the intervention were readily elicited afterwards in a stroke participant. Results of this study demonstrate that high-intensity resistance training of a non-paretic upper extremity muscle group can enhance voluntary muscle activation and force-generating capacity of a severely paretic muscle group after stroke. There is also preliminary evidence that corticospinal adaptations may accompany these gains

P2Y12 Receptor Blockade Augments Glycoprotein IIb‐IIIa Antagonist Inhibition of Platelet Activation, Aggregation, and Procoagulant Activity

Background: New antiplatelet agents that provide greater, more consistent inhibition of the platelet ADP receptor P2Y12 may be used in combination with glycoprotein (GP) IIb‐IIIa antagonists, but their combined effect on platelet function and procoagulant activity is not well studied. Therefore, the objective of this study was to evaluate the independent and complementary effects of P2Y12 and GPIIb‐IIIa inhibition on platelet function and procoagulant activity. Methods and Results: Healthy donor blood was treated with the active metabolite of prasugrel (R‐138727 5 μmol/L), GPIIb‐IIIa antagonists (abciximab 3 μg/mL or eptifibatide 0.9 μg/mL), and combinations thereof, exposed to physiologically relevant agonists (collagen and ADP) and then evaluated for markers of platelet activation and procoagulant activity. Significant interactions between R‐138727 and GPIIb‐IIIa antagonists were observed. R‐138727 and the GPIIb‐IIIa antagonists had additive inhibitory effects on collagen‐stimulated platelet aggregation and on the collagen plus ADP–stimulated level of activated platelet surface GPIIb‐IIIa. R‐138727 and abciximab each inhibited collagen plus ADP–stimulated platelet phosphatidylserine expression and prothrombin cleavage, and the combination produced greater inhibition than achieved with abciximab alone. In contrast, eptifibatide did not inhibit, but instead enhanced, collagen plus ADP–stimulated prothrombin cleavage. Addition of R‐138727 reduced prothrombin cleavage in eptifibatide‐treated samples, suggesting a novel mechanism for potential benefit from combined prasugrel and eptifibatide treatment. Conclusions: The complementary effects of abciximab and R‐138727 on platelet activation, aggregation, and procoagulant activity suggest their combined use may, to a greater degree than with either agent alone, reduce thrombus formation in vivo

Formative Evaluation of a Hepatitis C Virus Computer Assisted Instruction Tool or Communities of African Descent

Hepatitis C Virus (HCV) has become increasingly prevalent within traditionally undeserved communities. The paper describes the formative evaluation of a HCV Computer Assisted Instruction (CAI) tool. Specific aims are to describe the feasibility of a CAI tool with a high-risk population, and the use of Nigrescence Theory to develop targeted messages. Three participants, recruited at an all-male substance abuse halfway house, reviewed the CAI in a mini-focus group. A Health History/HCV Knowledge Questionnaire, The Cross Racial Identity Scale and a focus group question route were used to collect qualitative and quantitative data. The analysis plan utilized descriptive statistics, content analysis and profile analysis. Results suggested that the CAI was acceptable to this segment of the population, and Nigrescence Theory provided a context for targeting messages to differing segments of the target group. Recommendations are offered to health promotion programs targeting people of African descent

Mutation of NIMA-related kinase 1 (NEK1) leads to chromosome instability

<p>Abstract</p> <p>Background</p> <p>NEK1, the first mammalian ortholog of the fungal protein kinase never-in-mitosis A (NIMA), is involved early in the DNA damage sensing/repair pathway. A defect in DNA repair in NEK1-deficient cells is suggested by persistence of DNA double strand breaks after low dose ionizing radiation (IR). NEK1-deficient cells also fail to activate the checkpoint kinases CHK1 and CHK2, and fail to arrest properly at G1/S or G2/M-phase checkpoints after DNA damage.</p> <p>Results</p> <p>We show here that NEK1-deficient cells suffer major errors in mitotic chromosome segregation and cytokinesis, and become aneuploid. These NEK1-deficient cells transform, acquire the ability to grow in anchorage-independent conditions, and form tumors when injected into syngeneic mice. Genomic instability is also manifest in <it>NEK1 </it>+/- mice, which late in life develop lymphomas with a much higher incidence than wild type littermates.</p> <p>Conclusion</p> <p>NEK1 is required for the maintenance of genome stability by acting at multiple junctures, including control of chromosome stability.</p

pH-Sensing G Protein-Coupled Receptor OGR1 (GPR68) Expression and Activation Increases in Intestinal Inflammation and Fibrosis

Local extracellular acidification occurs at sites of inflammation. Proton-sensing ovarian cancer G-protein-coupled receptor 1 (OGR1, also known as GPR68) responds to decreases in extracellular pH. Our previous studies show a role for OGR1 in the pathogenesis of mucosal inflammation, suggesting a link between tissue pH and immune responses. Additionally, pH-dependent signalling is associated with the progression of intestinal fibrosis. In this study, we aimed to investigate OGR1 expression and OGR1-mediated signalling in patients with inflammatory bowel disease (IBD). Our results show that OGR1 expression significantly increased in patients with IBD compared to non-IBD patients, as demonstrated by qPCR and immunohistochemistry (IHC). Paired samples from non-inflamed and inflamed intestinal areas of IBD patients showed stronger OGR1 IHC staining in inflamed mucosal segments compared to non-inflamed mucosa. IHC of human surgical samples revealed OGR1 expression in macrophages, granulocytes, endothelial cells, and fibroblasts. OGR1-dependent inositol phosphate (IP) production was significantly increased in CD14+ monocytes from IBD patients compared to healthy subjects. Primary human and murine fibroblasts exhibited OGR1-dependent IP formation, RhoA activation, F-actin, and stress fibre formation upon an acidic pH shift. OGR1 expression and signalling increases with IBD disease activity, suggesting an active role of OGR1 in the pathogenesis of IBD. Keywords: OGR1 (GPR68) expression and function; fibroblasts; fibrosis; inflammatory bowel disease; pH-sensing GPCR

Glucocorticoid-induced leucine zipper modulates macrophage polarization and apoptotic cell clearance.

Macrophages are professional phagocytes that display remarkable plasticity, with a range of phenotypes that can be broadly characterized by the M1/M2 dichotomy. Glucocorticoid (GC)-induced leucine zipper (GILZ) is a protein known to mediate anti-inflammatory and some pro-resolving actions, including as neutrophil apoptosis. However, the role of GILZ in key macrophage function is not well understood. Here, we investigated the role of GILZ on macrophage reprogramming and efferocytosis. Using murine bone-marrow-derived macrophages (BMDMs), we found that GILZ was expressed in naive BMDMs and exhibited increased expression in M2-like macrophages (IL4-differentiated). M1-like macrophages (IFN/LPS-differentiated) from GILZ-/- mice showed higher expression of the M1 markers CD86, MHC class II, iNOS, IL-6 and TNF-α, associated with increased levels of phosphorylated STAT1 and lower IL-10 levels, compared to M1-differentiated cells from WT mice. There were no changes in the M2 markers CD206 and arginase-1 in macrophages from GILZ-/- mice differentiated with IL-4, compared to cells from WT animals. Treatment of M1-like macrophages with TAT-GILZ, a cell-permeable GILZ fusion protein, decreased the levels of CD86 and MHC class II in M1-like macrophages without modifying CD206 levels in M2-like macrophages. In line with the in vitro data, increased numbers of M1-like macrophages were found into the pleural cavity of GILZ-/- mice after LPS-injection, compared to WT mice. Moreover, efferocytosis was defective in the context of GILZ deficiency, both in vitro and in vivo. Conversely, treatment of LPS-injected mice with TAT-GILZ promoted inflammation resolution, associated with lower numbers of M1-like macrophages and increased efferocytosis. Collectively, these data indicate that GILZ is a regulator of important macrophage functions, contributing to macrophage reprogramming and efferocytosis, both key steps for the resolution of inflammation

Patient-physician interaction in general practice and health inequalities in a multidisciplinary study: design, methods and feasibility in the French INTERMEDE study

<p>Abstract</p> <p>Background</p> <p>The way in which patients and their doctors interact is a potentially important factor in optimal communication during consultations as well as treatment, compliance and follow-up care. The aim of this multidisciplinary study is to use both qualitative and quantitative methods to explore the 'black box' that is the interaction between the two parties during a general practice consultation, and to identify factors therein that may contribute to producing health inequalities. This paper outlines the original multidisciplinary methodology used, and the feasibility of this type of study.</p> <p>Methods and design</p> <p>The study design combines methodologies on two separate samples in two phases. Firstly, a qualitative phase collected ethnographical and sociological data during consultation, followed by in-depth interviews with both patients and doctors independently. Secondly, a quantitative phase on a different sample of patients and physicians collected data via several questionnaires given to patients and doctors consisting of specific 'mirrored' questions asked post-consultation, as well as collecting information on patient and physician characteristics.</p> <p>Discussion</p> <p>The design and methodology used in this study were both successfully implemented, and readily accepted by doctors and patients alike. This type of multidisciplinary study shows great potential in providing further knowledge into the role of patient/physician interaction and its influence on maintaining or producing health inequalities. The next challenge in this study will be implementing the multidisciplinary approach during the data analysis.</p

Cross-Sectional Study of Sleep Quantity and Quality and Amnestic and Non-Amnestic Cognitive Function in an Ageing Population: The English Longitudinal Study of Ageing (ELSA)

Background The aim was to investigate the association between sleep disturbances and cognitive function in younger and older individuals from an ageing population. Methods 3,968 male and 4,821 female white participants, aged 50 years and over, from the English Longitudinal Study of Ageing (ELSA) were studied. Information on sleep quality and quantity as well as both amnestic (memory, ACF) and non-amnestic (non-memory, nACF) function was available at Wave 4 (2008). Analysis of covariance was used to evaluate the relationship between sleep and cognitive function. Results After adjustment for multiple confounders in the younger group (50–64 years) duration of sleep explained 15.2% of the variance in ACF (p = 0.003) and 20.6% of nACF (p = 0.010). In the older group (65+ years) the estimates were 21.3% (p<0.001) and 25.6% (p<0.001), respectively. For sleep quality, there was a statistically significant association between sleep quality and both ACF (p<0.001) and nACF (p<0.001) in the older age group, but not in the younger age group (p = 0.586 and p = 0.373, respectively; interaction between age and sleep quality in the study sample including both age groups: p<0.001 for ACF and p = 0.018 for nACF). Sleep quality explained between 15.1% and 25.5% of the variance in cognition. The interaction with age was independent of duration of sleep. At any level of sleep duration there was a steeper association between sleep quality and ACF in the older than the younger group. Conclusions The associations between sleep disturbances and cognitive function vary between younger and older adults. Prospective studies will determine the temporal relationships between sleep disturbances and changes in cognition in different age groups

Biological marks of early-life socioeconomic experience is detected in the adult inflammatory transcriptome.

Consistent evidence is accumulating to link lower socioeconomic position (SEP) and poorer health, and the inflammatory system stands out as a potential pathway through which socioeconomic environment is biologically embedded. Using bloodderived genome-wide transcriptional profiles from 268 Italian participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, we evaluated the association between early life, young and later adulthood SEP and the expression of 845 genes involved in human inflammatory responses. These were examined individually and jointly using several inflammatory scores. Our results consistently show that participants whose father had a manual (as compared to nonmanual) occupation exhibit, later in life, a higher inflammatory score, hence indicating an overall increased level of expression for the selected inflammatory-related genes. Adopting a life course approach, these associations remained statistically significant upon adjustment for later-in-life socioeconomic experiences. Sensitivity analyses indicated that our findings were not affected by the way the inflammatory score was calculated, and were replicated in an independent study. Our study provides additional evidence that childhood SEP is associated with a sustainable upregulation of the inflammatory transcriptome, independently of subsequent socioeconomic experiences. Our results support the hypothesis that early social inequalities impacts adult physiology