A real-time computational model for estimating kinematics of ankle ligaments

Background: An accurate assessment of ankle ligament kinematics is crucial in understanding the injury mechanisms and can help to improve the treatment of an injured ankle, especially when used in conjunction with robot-assisted therapy. A number of computational models have been developed and validated for assessing the kinematics of ankle ligaments. However, few of them can do real-time assessment to allow for an input into robotic rehabilitation programs. Method: An ankle computational model was proposed and validated to quantify the kinematics of ankle ligaments as the foot moves in real-time. This model consists of three bone segments with three rotational degrees of freedom (DOFs) and 12 ankle ligaments. This model uses inputs for three position variables that can be measured from sensors in many ankle robotic devices that detect postures within the foot–ankle environment and outputs the kinematics of ankle ligaments. Validation of this model in terms of ligament length and strain was conducted by comparing it with published data on cadaver anatomy and magnetic resonance imaging. Results: The model based on ligament lengths and strains is in concurrence with those from the published studies but is sensitive to ligament attachment positions. Conclusions: This ankle computational model has the potential to be used in robot-assisted therapy for real-time assessment of ligament kinematics. The results provide information regarding the quantification of kinematics associated with ankle ligaments related to the disability level and can be used for optimizing the robotic training trajectory.     

Updating age-specific contact structures to match evolving demography in a dynamic mathematical model of tuberculosis vaccination

We investigated the effects of updating age-specific social contact matrices to match evolving demography on vaccine impact estimates. We used a dynamic transmission model of tuberculosis in India as a case study. We modelled four incremental methods to update contact matrices over time, where each method incorporated its predecessor: fixed contact matrix (M0), preserved contact reciprocity (M1), preserved contact assortativity (M2), and preserved average contacts per individual (M3). We updated the contact matrices of a deterministic compartmental model of tuberculosis transmission, calibrated to epidemiologic data between 2000 and 2019 derived from India. We additionally calibrated the M0, M2, and M3 models to the 2050 TB incidence rate projected by the calibrated M1 model. We stratified age into three groups, children (<15y), adults (≥15y, <65y), and the elderly (≥65y), using World Population Prospects demographic data, between which we applied POLYMOD-derived social contact matrices. We simulated an M72-AS01_E-like tuberculosis vaccine delivered from 2027 and estimated the per cent TB incidence rate reduction (IRR) in 2050 under each update method. We found that vaccine impact estimates in all age groups remained relatively stable between the M0–M3 models, irrespective of vaccine-targeting by age group. The maximum difference in impact, observed following adult-targeted vaccination, was 7% in the elderly, in whom we observed IRRs of 19% (uncertainty range 13–32), 20% (UR 13–31), 22% (UR 14–37), and 26% (UR 18–38) following M0, M1, M2 and M3 updates, respectively. We found that model-based TB vaccine impact estimates were relatively insensitive to demography-matched contact matrix updates in an India-like demographic and epidemiologic scenario. Current model-based TB vaccine impact estimates may be reasonably robust to the lack of contact matrix updates, but further research is needed to confirm and generalise this finding.     

A proposal for a goodness-of-fit test to the Arnason-Schwarz multisite capture-recapture model

In an analysis of capture-recapture data, the identification of a model that fits is a critical step. For the multisite (also called multistate) models used to analyze data gathered at several sites, no reliable test for assessing fit is currently available. We propose a test for the JMV model, a simple generalization of the Arnason-Schwarz (AS) model, in the form of interpretable contingency tables. For the AS model, we suggest complementing the test for the JMV model with a likelihood ratio test of AS vs. JMV. The examination of an example leads us to propose further a partitioning that emphasizes the role of the memory model of Brownie et al. (1993 Biometrics 49, 1173-1187) as a biologically more plausible alternative to the AS model.     

A realist process evaluation within the Facilitating Implementation of Research Evidence (FIRE) cluster randomised controlled international trial: an exemplar

Background

Facilitation is a promising implementation intervention, which requires theory-informed evaluation. This paper presents an exemplar of a multi-country realist process evaluation that was embedded in the first international randomised controlled trial evaluating two types of facilitation for implementing urinary continence care recommendations. We aimed to uncover what worked (and did not work), for whom, how, why and in what circumstances during the process of implementing the facilitation interventions in practice.

Methods

This realist process evaluation included theory formulation, theory testing and refining. Data were collected in 24 care home sites across four European countries. Data were collected over four time points using multiple qualitative methods: observation (372 h), interviews with staff (n?=?357), residents (n?=?152), next of kin (n?=?109) and other stakeholders (n?=?128), supplemented by facilitator activity logs. A combined inductive and deductive data analysis process focused on realist theory refinement and testing.

Results

The content and approach of the two facilitation programmes prompted variable opportunities to align and realign support with the needs and expectations of facilitators and homes. This influenced their level of confidence in fulfilling the facilitator role and ability to deliver the intervention as planned. The success of intervention implementation was largely dependent on whether sites prioritised their involvement in both the study and the facilitation programme. In contexts where the study was prioritised (including release of resources) and where managers and staff support was sustained, this prompted collective engagement (as an attitude and action). Internal facilitators’ (IF) personal characteristics and abilities, including personal and formal authority, in combination with a supportive environment prompted by managers triggered the potential for learning over time. Learning over time resulted in a sense of confidence and personal growth, and enactment of the facilitation role, which resulted in practice changes.

Conclusion

The scale and multi-country nature of this study provided a novel context to conduct one of the few trial embedded realist-informed process evaluations. In addition to providing an explanatory account of implementation processes, a conceptual platform for future facilitation research is presented. Finally, a realist-informed process evaluation framework is outlined, which could inform future research of this nature.

Trial registration

Current controlled trials ISRCTN11598502.

     

Tumor destruction using electrochemotherapy followed by CpG oligodeoxynucleotide injection induces distant tumor responses

PURPOSE: Electrochemotherapy (ECT) is an effective local therapy of human cutaneous cancers but has no effect on distant untreated tumors. We addressed whether tumor-associated antigens released after ECT could induce an efficient systemic immunity when associated with an appropriate immunoadjuvant. METHODS AND RESULTS: We first studied the nature of the cellular recruitment and the expression of various toll-like receptors (TLRs) in tumors treated by ECT. We found that ECT induced a massive recruitment of CD11c and CD11b positive cells in the tumors and a strong increase of TLR9 expression. We then tested antitumor effects of the combination: ECT followed by TLR-9 ligands, CpG oligodeoxynucleotides (CpG ODN), in three murine tumor models. We found that this combination triggered both potent local synergistic antitumor effects, on the ipsi-lateral ECT-treated tumor, and more interestingly, a systemic antitumor response on the contra-lateral untreated tumor, in the three models. The systemic protection was T-cell dependent as it was not observed in nude littermates. The combination induced tumor-specific T cell effectors in the tumor-draining lymph nodes and in the spleen which secreted significantly more gamma-interferon upon activation than with ECT or CpG ODN alone. CONCLUSIONS: Our data show that ECT and CpG ODN synergize and induce a significant increase of the local effect and a systemic T-dependent antitumor response. Such combination constitutes a potential innovative vaccination strategy using in situ tumor-associated antigens that could eventually be translated into the clinic.     

Revisiting the structure/function relationships of H/ACA(-like) RNAs: a unified model for Euryarchaea and Crenarchaea

A structural and functional classification of H/ACA and H/ACA-like motifs is obtained from the analysis of the H/ACA guide RNAs which have been identified previously in the genomes of Euryarchaea (Pyrococcus) and Crenarchaea (Pyrobaculum). A unified structure/function model is proposed based on the common structural determinants shared by H/ACA and H/ACA-like motifs in both Euryarchaea and Crenarchaea. Using a computational approach, structural and energetic rules for the guide:target RNA-RNA interactions are derived from structural and functional data on the H/ACA RNP particles. H/ACA(-like) motifs found in Pyrococcus are evaluated through the classification and their biological relevance is discussed. Extra-ribosomal targets found in both Pyrococcus and Pyrobaculum might support the hypothesis of a gene regulation mediated by H/ACA(-like) guide RNAs in archaea.     

Phosphotyrosine phosphatase and tyrosine kinase inhibition modulate airway pressure-induced lung injury

We determinedwhether drugs which modulate the state of protein tyrosinephosphorylation could alter the threshold for high airwaypressure-induced microvascular injury in isolated perfused rat lungs.Lungs were ventilated for successive 30-min periods with peak inflationpressures (PIP) of 7, 20, 30, and 35 cmH₂O followed by measurement ofthe capillary filtration coefficient (K_fc), asensitive index of hydraulic conductance. In untreated control lungs,K_fc increased by1.3- and 3.3-fold relative to baseline (7 cmH₂O PIP) after ventilation with30 and 35 cmH₂O PIP. However, inlungs treated with 100 µM phenylarsine oxide (a phosphotyrosinephosphatase inhibitor),K_fc increased by4.7- and 16.4-fold relative to baseline at these PIP values. In lungs treated with 50 µM genistein (a tyrosine kinase inhibitor),K_fc increasedsignificantly only at 35 cmH₂OPIP, and the three groups were significantly different from each other.Thus phosphotyrosine phosphatase inhibition increased thesusceptibility of rat lungs to high-PIP injury, and tyrosine kinaseinhibition attenuated the injury relative to the high-PIP control lungs.