Membrane fluidity, capping of cell-surface antigens and immune response in mouse leukaemia cells.

Transplantation of primary GRSL cells in the ascitic form led to a decrease in membrane microviscosity as measured by the fluorescence polarization technique. The transplanted GRSL ascitic cells showed a markedly lower ability to form caps with respect to both virus-related (MLr, GIX) and normal (H-2.7(G), H-2.8(K) and TL1.2) cell-surface antigens and their appropriate antisera in the indirect membrane immunofluorescence tests, than did primary GRSL cells, transplanted GRSL cells growing in solid form, and thymocytes, which all exhibited significantly higher membrane microviscosities. Transplantation of primary GRSL cells into syngeneic mice pre-irradiated with 400 rad did not lead to a fall in membrane microviscosity. It is suggested that the host immune response in intact mice leads to a selective survival of ascitic tumour cells with low membrane microviscosity

Irrigant flow in the root canal during ultrasonic activation:A numerical fluid-structure interaction model and its validation

Aim: The aim of the study was (a) to develop a three-dimensional numerical model combining the oscillation of a tapered ultrasonic file and the induced irrigant flow along with their two-way interaction in the confinement of a root canal. (b) To validate this model through comparison with experiments and theoretical (analytical) solutions of the flow. Methodology: Two partial numerical models, one for the oscillation of the ultrasonic file and another one for the irrigant flow inside the root canal around the file, were created and coupled in order to take into account the two-way coupled fluid–structure interaction. Simulations were carried out for ultrasonic K-files and for smooth wires driven at four different amplitudes in air or inside an irrigant-filled straight root canal. The oscillation pattern of the K-files was determined experimentally by Scanning Laser Vibrometry, and the flow pattern inside an artificial root canal was analysed using high-speed imaging together with Particle Image Velocimetry. Analytical solutions were obtained from an earlier study. Numerical, experimental and analytical results were compared to assess the validity of the model. Results: The comparison of the oscillation amplitude and node location of the ultrasonic files and of the irrigant flow field showed a close agreement between the simulations, experiments and theoretical solutions. Conclusions: The model is able to predict reliably the file oscillation and irrigant flow inside root canals during ultrasonic activation under similar conditions

A stepwise transformation:description and outcome of perioperative procedures in patients receiving a total knee arthroplasty

Aims To investigate the impact of consecutive perioperative care transitions on in-hospital recovery of patients who had primary total knee arthroplasty (TKA) over an 11-year period. Methods This observational cohort study used electronic health record data from all patients undergoing preoperative screening for primary TKA at a northern netherlands hospital between 2009 and 2020. In this timeframe, three perioperative care transitions were divided into four periods: Baseline care (Joint Care, n = 171; May 2009 to August 2010), Function-tailored (n = 404; September 2010 to October 2013), Fast-track (n = 721; november 2013 to May 2018), and Prehabilitation (n = 601; June 2018 to December 2020). In-hospital recovery was measured using inpatient recovery of activities (IROA), length of stay (LOS), and discharge to preoperative living situation (PLS). Multivariable regression models were used to analyze the impact of each perioperative care transition on in-hospital recovery. Results The four periods analyzed involved 1,853 patients (65.9% female (1,221/1,853); mean age 70.1 years (SD 9.0)). IROA improved significantly with each transition: Function-tailored (0.9 days; p &lt; 0.001 (95% confidence interval (CI) -0.32 to -0.15)), Fast-track (0.6 days; p &lt; 0.001 (95% CI -0.25 to -0.16)), and Prehabilitation (0.4 days; p &lt; 0.001 (95% CI -0.18 to -0.10)). LOS decreased significantly in Function-tailored (1.1 days; p = 0.001 (95% CI -0.30 to -0.06)), Fast-track (0.6 days; p &lt; 0.001 (95% CI -0.21 to -0.05)), and Prehabilitation (0.6 days; p &lt; 0.001 (95%CI -0.27 to -0.11)). Discharge to PLS increased in Function-tailored (77%), Fast-track (91.6%), and Prehabilitation (92.6%). Post-hoc analysis indicated a significant increase after the transition to the Fast-track period (p &lt; 0.001 (95% CI 3.19 to 8.00)). Conclusion This study highlights the positive impact of different perioperative care procedures on in-hospital recovery of patients undergoing primary TKA. Assessing functional recovery, LOS, and discharge towards PLS consistently, provides hospitals with valuable insights into postoperative recovery. This can potentially aid planning and identifying areas for targeted improvements to optimize patient outcomes.</p

A stepwise transformation:description and outcome of perioperative procedures in patients receiving a total knee arthroplasty

Aims To investigate the impact of consecutive perioperative care transitions on in-hospital recovery of patients who had primary total knee arthroplasty (TKA) over an 11-year period. Methods This observational cohort study used electronic health record data from all patients undergoing preoperative screening for primary TKA at a northern netherlands hospital between 2009 and 2020. In this timeframe, three perioperative care transitions were divided into four periods: Baseline care (Joint Care, n = 171; May 2009 to August 2010), Function-tailored (n = 404; September 2010 to October 2013), Fast-track (n = 721; november 2013 to May 2018), and Prehabilitation (n = 601; June 2018 to December 2020). In-hospital recovery was measured using inpatient recovery of activities (IROA), length of stay (LOS), and discharge to preoperative living situation (PLS). Multivariable regression models were used to analyze the impact of each perioperative care transition on in-hospital recovery. Results The four periods analyzed involved 1,853 patients (65.9% female (1,221/1,853); mean age 70.1 years (SD 9.0)). IROA improved significantly with each transition: Function-tailored (0.9 days; p &lt; 0.001 (95% confidence interval (CI) -0.32 to -0.15)), Fast-track (0.6 days; p &lt; 0.001 (95% CI -0.25 to -0.16)), and Prehabilitation (0.4 days; p &lt; 0.001 (95% CI -0.18 to -0.10)). LOS decreased significantly in Function-tailored (1.1 days; p = 0.001 (95% CI -0.30 to -0.06)), Fast-track (0.6 days; p &lt; 0.001 (95% CI -0.21 to -0.05)), and Prehabilitation (0.6 days; p &lt; 0.001 (95%CI -0.27 to -0.11)). Discharge to PLS increased in Function-tailored (77%), Fast-track (91.6%), and Prehabilitation (92.6%). Post-hoc analysis indicated a significant increase after the transition to the Fast-track period (p &lt; 0.001 (95% CI 3.19 to 8.00)). Conclusion This study highlights the positive impact of different perioperative care procedures on in-hospital recovery of patients undergoing primary TKA. Assessing functional recovery, LOS, and discharge towards PLS consistently, provides hospitals with valuable insights into postoperative recovery. This can potentially aid planning and identifying areas for targeted improvements to optimize patient outcomes.</p

The effect of feedback during training sessions on learning pattern-recognition based prosthesis control

Human-machine interfaces have not yet advanced to enable intuitive control of multiple degrees of freedom as offered by modern myoelectric prosthetic hands. Pattern Recognition (PR) control has been proposed to make human-machine interfaces in myoelectric prosthetic hands more intuitive, but it requires the user to generate high-quality, i.e., consistent and separable, electromyogram (EMG) patterns. To generate such patterns, user training is required and has shown promising results. However, how different levels of feedback affect effectivity in training differently, has not been established yet. Furthermore, a correlation between qualities of the EMG patterns (the focus of training) and user performance has not been shown yet. In this study, 37 able-bodied participants (mean age 21 years, 19 males) were recruited and trained PR control over five days. Three levels of feedback were tested for their effectiveness: no external feedback, visual feedback and visual feedback with coaching. Training resulted in improved performance from pre-to post-test with no interaction effect of feedback. Feedback did however affect the quality of the EMG patterns where people who did not receive external feedback generated higher amplitude patterns. A weak correlation was found between a principal component, composed of EMG amplitude and pattern variability, and performance. Our results show that training is highly effective in improving PR control regardless of feedback and that none of the quality metrics correlate with performance. We discuss how different levels of feedback can be leveraged to improve PR control training

Serious gaming to generate separated and consistent EMG patterns in pattern-recognition prosthesis control

Pattern-Recognition (PR) control of upper-limb prosthetics has shown inconsistent results outside lab settings, which might be due to the inadequacy of users’ electromyogram (EMG) patterns. To improve the separability and consistency of their EMG, users can receive training. Conventional training uses an internal focus of attention as prosthesis users focus on the muscle contractions of their (phantom) hand together with explicit learning processes facilitated by a coach guiding the user. In this study we investigated if an alternative training paradigm using an external focus of attention exploiting implicit learning processes based on serious gaming without a coach could lead to more separable and consistent EMG. Able-bodied participants (N = 25; mean age 22 years, 13 females) were recruited and followed conventional or game training for five days. In conventional training, participants performed the Motion Test thrice daily and received coaching on how to adapt their muscle contractions. In game training, participants controlled an avatar using a direct mapping from electrode to avatar direction. The participants utilized implicit learning processes, by exploring which muscle contractions made the avatar go in which directions. Performance in both groups was evaluated by using the Motion Test in a pre/post-test design. Training resulted in improved performance, with no differences between training paradigms. Participants who followed game training showed 51% more separated EMG patterns. EMG pattern consistency did not change over training. It was concluded that serious game training using an external focus of attention and implicit learning can be considered as a viable alternative to conventional training.</p

White Blood Cell Count Mediates the Association Between Periodontal Inflammation and Cognitive Performance Measured by Digit Symbol Substitution Test Among Older U.S. Adults

BACKGROUND: Systemic effects of periodontal infection may increase the risk of central neuroinflammation, aggravating impaired cognition. This study aims to examine whether systemic inflammatory factors mediate the possible association between periodontal inflammation and cognitive function. METHODS: We conducted a cross-sectional analysis of 766 participants aged > 60 years and who had complete periodontal and cognitive examinations in the NHANES 2001-2002. We used multivariable linear regression to investigate the overall association between periodontal health and cognitive function as measured by the digit symbol substitution test (DSST). Bleeding on probing (BOP) and periodontal inflamed surface area (PISA) were used to assess the periodontal inflammatory activity and burden, respectively. Mediation analyses were used to test the indirect effects of the BOP/PISA on DSST via C-reactive protein, white blood cell (WBC) count, and fibrinogen. RESULTS: Participants with superior periodontal health obtained higher DSST scores than those with poorer periodontal health, adjusting for demographic factors and chronic conditions. Concerning the inflammatory activity, WBC count acted as a full mediator in the association between BOP and DSST (β = -0.091; 95% CI = -0.174 to -0.008) and mediated 27.5% of the total association. Regarding the inflammatory burden, WBC count acted as a partial mediator in the association between PISA and DSST (β = -0.059; 95% CI = -0.087 to -0.031) and mediated 20.3% of the total association. CONCLUSION: Our study indicated the potential role of systemic inflammatory factors as a mediator of associations between periodontal inflammation and cognitive function in the U.S. geriatric population

Should Hands Be Restricted When Measuring Able-Bodied Participants To Evaluate Machine Learning Controlled Prosthetic Hands?

OBJECTIVE: When evaluating methods for machine-learning controlled prosthetic hands, able-bodied participants are often recruited, for practical reasons, instead of participants with upper limb absence (ULA). However, able-bodied participants have been shown to often perform myoelectric control tasks better than participants with ULA. It has been suggested that this performance difference can be reduced by restricting the wrist and hand movements of able-bodied participants. However, the effect of such restrictions on the consistency and separability of the electromyogram's (EMG) features remains unknown. The present work investigates whether the EMG separability and consistency between unaffected and affected arms differ and whether they change after restricting the unaffected limb in persons with ULA. METHODS: Both arms of participants with unilateral ULA were compared in two conditions: with the unaffected hand and wrist restricted or not. Furthermore, it was tested if the effect of arm and restriction is influenced by arm posture (arm down, arm in front, or arm up). RESULTS: Fourteen participants (two women, age=53.4±4.05) with acquired transradial limb loss were recruited. We found that the unaffected limb generated more separated EMG than the affected limb. Furthermore, restricting the unaffected hand and wrist lowered the separability of the EMG when the arm was held down. CONCLUSION: Limb restriction is a viable method to make the EMG of able-bodied participants more similar to that of participants with ULA. SIGNIFICANCE: Future research that evaluates methods for machine learning controlled hands in able-bodied participants should restrict the participants' hand and wrist

Decision-making experiences of patients and partners opting for active surveillance in esophageal cancer treatment

Objectives: This study explored the decision-making experiences of patients and their partners or primary caregiver who opted for experimental active surveillance (instead of standard surgery) for the treatment of esophageal cancer. Methods: Seventeen couples participated. Semi-structured interviews were conducted on couples’ joint experiences as well as their individual experiences. Preferred and perceived role in the treatment decision-making process was assessed using the adjusted version of the Control Preferences Scale, and perceived influence on the treatment decision was measured using a visual analog scale. Results: Couples reflected on the decision-making process as a positive collaboration, where patients retain their autonomy by making the final decision, and partners offer emotional support. Couples reported about an overwhelming amount and sometimes conflicting information about treatments among different hospitals and healthcare providers. Conclusions: Patients often involve their partner in decision-making, which they report to have enhanced their ability to cope with the disease. The amount and sometimes conflicting information during the decision-making process provide opportunities for improvement. Practice implications: Couples can benefit from an overview of what they can expect during treatment course. If active surveillance becomes an established treatment option in the future, provision of such overviews and consistent information should become more streamlined.</p

Decision-making experiences of patients and partners opting for active surveillance in esophageal cancer treatment

Objectives: This study explored the decision-making experiences of patients and their partners or primary caregiver who opted for experimental active surveillance (instead of standard surgery) for the treatment of esophageal cancer. Methods: Seventeen couples participated. Semi-structured interviews were conducted on couples’ joint experiences as well as their individual experiences. Preferred and perceived role in the treatment decision-making process was assessed using the adjusted version of the Control Preferences Scale, and perceived influence on the treatment decision was measured using a visual analog scale. Results: Couples reflected on the decision-making process as a positive collaboration, where patients retain their autonomy by making the final decision, and partners offer emotional support. Couples reported about an overwhelming amount and sometimes conflicting information about treatments among different hospitals and healthcare providers. Conclusions: Patients often involve their partner in decision-making, which they report to have enhanced their ability to cope with the disease. The amount and sometimes conflicting information during the decision-making process provide opportunities for improvement. Practice implications: Couples can benefit from an overview of what they can expect during treatment course. If active surveillance becomes an established treatment option in the future, provision of such overviews and consistent information should become more streamlined.</p