A Multilaboratory Comparison of Calibration Accuracy and the Performance of External References in Analytical Ultracentrifugation

Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies

A multilaboratory comparison of calibration accuracy and the performance of external references in analytical ultracentrifugation.

Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies

Minimally Invasive Diagnosis of Secondary Intracranial Lymphoma

Diffuse large B cell lymphomas (DLBCL) are an aggressive group of non-Hodgkin lymphoid malignancies which have diverse presentation and can have high mortality. Central nervous system relapse is rare but has poor survival. We present the diagnosis of primary mandibular DLBCL and a unique minimally invasive diagnosis of secondary intracranial recurrence. This case highlights the manifold radiological contributions to the diagnosis and management of lymphoma

Determining the feasibility and acceptability of a mobile health application to remotely monitor the symptoms of people with mesothelioma at home

Introduction: people with MPM have a high symptom burden, often experiencing several concurrent symptoms, including breathlessness, anxiety, fatigue, weakness, pain, anorexia, sweating, weight loss and depression. Transitions in services from in-patient to local settings compounds this situation, as people with MPM have to manage their symptoms at home, often in the absence of clinicians. Advances in technologies such as mobile phones provide a means to remotely monitor the symptoms of people with MPM at home, support self-management and alert clinicians where appropriate. Studies of remote symptom monitoring in cancer have reported significant improvements in symptom management, quality of life and survival. To date, no studies have explored the use of remote symptom monitoring in people with MPM.Methods: this study tested a novel, remote symptom monitoring system for people with MPM and explored its feasibility and acceptability. A total of 17 patients were recruited from 4 UK sites. Patients used the system for 2–3 months. Each day they completed a symptom questionnaire on the mobile phone and sent this information to the study server where an algorithm assessed reports and where appropriate triggered alerts to clinicians. Patients also received self-care advice relating to their symptoms. On receipt of an alert, clinicians logged on to a secure web page, viewed the reports and contacted the patient. Alert response data and patient reported outcome measures were analysed. Interviews were conducted with people with MPM, carers and clinicians to determine the feasibility and acceptability of the system in practice.Results: demonstrate that people with MPM, carers and clinicians perceived the remote monitoring of symptoms to be feasible and acceptable. Suggestions were made to enhance future functionality of the system.Conclusion: findings support conduct of further studies evaluating the effectiveness of remote symptom monitoring in people with MPM and its impact on outcomes including survival.Disclosure: all authors have declared no conflicts of interest