Vinculin controls talin engagement with the actomyosin machinery

The link between extracellular-matrix-bound integrins and intracellular F-actin is essential for cell spreading and migration. Here, we demonstrate how the actin-binding proteins talin and vinculin cooperate to provide this link. By expressing structure-based talin mutants in talin null cells, we show that while the C-terminal actin-binding site (ABS3) in talin is required for adhesion complex assembly, the central ABS2 is essential for focal adhesion (FA) maturation. Thus, although ABS2 mutants support cell spreading, the cells lack FAs, fail to polarize and exert reduced force on the surrounding matrix. ABS2 is inhibited by the preceding mechanosensitive vinculin-binding R3 domain, and deletion of R2R3 or expression of constitutively active vinculin generates stable force-independent FAs, although cell polarity is compromised. Our data suggest a model whereby force acting on integrin-talin complexes via ABS3 promotes R3 unfolding and vinculin binding, activating ABS2 and locking talin into an actin-binding configuration that stabilizes FAs

A Clinical Feasibility Study of the Forensic Psychiatry and Violence Oxford (FoVOx) Tool

Background: Risk assessment informs decisions around admission to and discharge from secure psychiatric hospital and contributes to treatment and supervision. There are advantages to using brief, scalable, free online tools with similar accuracy to instruments currently used. We undertook a study of one such risk assessment, the Forensic Psychiatry and Violence Oxford (FoVOx) tool, examining its acceptability, feasibility, and practicality. Methods: We completed the FoVOx tool on all discharges from six secure psychiatric hospitals in one region in England over two years. We interviewed 11 senior forensic psychiatrists regarding each discharge using a standardized questionnaire. Their patient’s FoVOx score was compared to clinical risk assessment, and the senior clinicians were asked if they considered FoVOx scores accurate and useful. A modified thematic analysis was conducted, and clinicians were surveyed about current risk assessment practice on discharge. Results: Of 90 consecutive discharges, 84 were included in the final analysis. The median FoVOx probability score was 11% risk of violent recidivism in two years after discharge. We estimated that 12 (14%) individuals reoffended since discharge; all were in the medium or high risk FoVOx categories. Clinical assessment of risk agreed with the FoVOx categories in around half the cases. Clinicians were more likely to provide lower risk categories compared with FoVOx ones. FoVOx was considered to be an accurate representation of risk in 67% of cases; clinicians revised their view on some patient’s risk assessment after being informed of their FoVOx scores. Completing FoVOx was reported to be helpful in the majority of cases. Reasons included improved communication with other agencies, reassurance to clinical teams, and identifying additional factors not fully considered. 10 of the 11 respondents reported that FoVOx was practical, and seven of 11 reported that they would use it in the future, highlighting its brevity and speed of use compared to existing risk assessment tools. Conclusions: Senior clinicians in this regional forensic psychiatric service found the FoVOx risk assessment tool feasible, practical, and easy to use. Its use addressed a lack of consistency around risk assessment at the point of discharge and, if used routinely, could assist in clinical decision-making.</br

Reliability and validity of the FORUM-P and FORUM-C: two novel instruments for outcome measurement in forensic mental health

We conducted a series of tests on the FORensic oUtcome Measure (FORUM), a novel tool for measuring outcomes in forensic mental health services, which consists of complementary patient-reported (FORUM-P) and clinician-reported instruments (FORUM-C). Inpatients and outpatients at a UK forensic psychiatric regional service completed the FORUM-P and members of their clinical teams completed the FORUM-C. Patients and clinicians also provided qualitative feedback on the instruments. We assessed test-retest and inter-rater reliability in standard ways. Sixty-two patients participated with a mean age of 41.0 years (standard deviation 11.3). Thirty-five clinicians provided information about these patients. For internal consistency, Cronbach’s alpha for FORUM-P was 0.87 (95% confidence interval 0.80–0.93) and for FORUM-C was 0.93 (95% confidence interval 0.91–0.96). For test-retest reliability, weighted kappa for FORUM-P was 0.44 (95% confidence interval 0.24–0.63) and for FORUM-C was 0.78 (95% confidence interval 0.73–0.85). For inter-rater reliability, Spearman correlation coefficient for overall FORUM-C score between the first rating by clinician 1 and clinician 2 was 0.47 (95% confidence interval 0.18–0.69). For comprehensiveness, comprehensibility, and relevance FORUM-P and FORUM-C were both rated as good. FORUM-P and FORUM-C provide a novel, robust set of complementary instruments with promising psychometric properties for monitoring outcomes in forensic mental health

Intraoperative transfusion practices in Europe

BACKGROUND: Transfusion of allogeneic blood influences outcome after surgery. Despite widespread availability of transfusion guidelines, transfusion practices might vary among physicians, departments, hospitals and countries. Our aim was to determine the amount of packed red blood cells (pRBC) and blood products transfused intraoperatively, and to describe factors determining transfusion throughout Europe. METHODS: We did a prospective observational cohort study enrolling 5803 patients in 126 European centres that received at least one pRBC unit intraoperatively, during a continuous three month period in 2013. RESULTS: The overall intraoperative transfusion rate was 1.8%; 59% of transfusions were at least partially initiated as a result of a physiological transfusion trigger- mostly because of hypotension (55.4%) and/or tachycardia (30.7%). Haemoglobin (Hb)- based transfusion trigger alone initiated only 8.5% of transfusions. The Hb concentration [mean (sd)] just before transfusion was 8.1 (1.7) g dl(-1) and increased to 9.8 (1.8) g dl(-1) after transfusion. The mean number of intraoperatively transfused pRBC units was 2.5 (2.7) units (median 2). CONCLUSION: Although European Society of Anaesthesiology transfusion guidelines are moderately implemented in Europe with respect to Hb threshold for transfusion (7-9 g dl(-1)), there is still an urgent need for further educational efforts that focus on the number of pRBC units to be transfused at this threshold. CLINICAL TRIAL REGISTRATION: NCT 01604083

Talin Dependent Mechanosensitivity of Cell Focal Adhesions

A fundamental question in mechanobiology is how mechanical stimuli are sensed by mechanosensing proteins and converted into signals that direct cells to adapt to the external environment. A key function of cell adhesion to the extracellular matrix (ECM) is to transduce mechanical forces between cells and their extracellular environment. Talin, a cytoplasmic adapter essential for integrin-mediated adhesion to the ECM, links the actin cytoskeleton to integrin at the plasma membrane. Here, we review recent progress in the understanding of talin-dependent mechanosensing revealed by stretching single talin molecules. Rapid progress in single-molecule force manipulation technologies has made it possible to directly study the impact of mechanical force on talin’s conformations and its interactions with other signaling proteins. We also provide our views on how findings from such studies may bring new insights into understanding the principles of mechanobiology on a broader scale, and how such fundamental knowledge may be harnessed for mechanopharmacology