A prospective, active haemovigilance study with combined cohort analysis of 19,175 transfusions of platelet components prepared with amotosalen-UVA photochemical treatment

BACKGROUND AND OBJECTIVES

A photochemical treatment process (PCT) utilizing amotosalen and UVA light (INTERCEPT(™) Blood System) has been developed for inactivation of viruses, bacteria, parasites and leucocytes that can contaminate blood components intended for transfusion. The objective of this study was to further characterize the safety profile of INTERCEPT-treated platelet components (PCT-PLT) administered across a broad patient population.

MATERIALS AND METHODS

This open-label, observational haemovigilance programme of PCT-PLT transfusions was conducted in 21 centres in 11 countries. All transfusions were monitored for adverse events within 24 h post-transfusion and for serious adverse events (SAEs) up to 7 days post-transfusion. All adverse events were assessed for severity (Grade 0-4), and causal relationship to PCT-PLT transfusion.

RESULTS

Over the course of 7 years in the study centres, 4067 patients received 19,175 PCT-PLT transfusions. Adverse events were infrequent, and most were of Grade 1 severity. On a per-transfusion basis, 123 (0.6%) were classified an acute transfusion reaction (ATR) defined as an adverse event related to the transfusion. Among these ATRs, the most common were chills (77, 0.4%) and urticaria (41, 0.2%). Fourteen SAEs were reported, of which 2 were attributed to platelet transfusion (<0.1%). No case of transfusion-related acute lung injury, transfusion-associated graft-versus-host disease, transfusion-transmitted infection or death was attributed to the transfusion of PCT-PLT.

CONCLUSION

This longitudinal haemovigilance safety programme to monitor PCT-PLT transfusions demonstrated a low rate of ATRs, and a safety profile consistent with that previously reported for conventional platelet components.

A progressive assessment strategy improves student learning and perceived course quality in undergraduate physiology

In 2010, second-year physiology (n = 165) had a traditional single 3-h end-of-semester exam. To provide diagnostic feedback earlier, for students enrolled in 2011 (n = 128), we incorporated an in-class exam at 3 wk in addition to the final exam. Based on initial analysis and positive student comments, for the 2012 cohort (n = 148), we expanded this to incorporate four 1-h in-class exams every 3 wk plus a short final integrative exam. Average scores from exams and questionnaires (student evaluations of learning and teaching, 10 questions) were compared among 2010, 2011, and 2012 cohorts. We also compared scores in the practical component of the course, which had a constant format for all cohorts. Data are given as means ± SD; statistical analyses were done with unpaired two-way Students t-tests. From 2010 to 2012, there was a significant improvement in total exam scores (59.7 ± 15.8 vs. 68.6 ± 14.2, P < 0.001) but no significant change in total practical scores (72.3 ± 9.0 vs. 74.4 ± 10.2, P = 0.05), indicating that the rise in exam score was not due to higher academic abilities of the 2012 cohort. Overall mean student evaluation of learning and teaching responses (4.9 ± 0.4 vs. 5.3 ± 0.3, P = 0.015) and overall percent broad agreement (66.0 ± 8.0 vs. 79.2 ± 7.5, P = 0.003) indicated a significant improvement in student satisfaction. In conclusion, both learning outcome and perceived course quality were enhanced by the increased frequency of examinations, possibly by promoting consistent student study habits.

A dual two dimensional electronic portal imaging device transit dosimetry model based on an empirical quadratic formalism

OBJECTIVE

This study describes a two dimensional electronic portal imaging device (EPID) transit dosimetry model that can predict either: (1) in-phantom exit dose, or (2) EPID transit dose, for treatment verification.

METHODS

The model was based on a quadratic equation that relates the reduction in intensity to the equivalent path length (EPL) of the attenuator. In this study, two sets of quadratic equation coefficients were derived from calibration dose planes measured with EPID and ionization chamber in water under reference conditions. With two sets of coefficients, EPL can be calculated from either EPID or treatment planning system (TPS) dose planes. Consequently, either the in-phantom exit dose or the EPID transit dose can be predicted from the EPL. The model was tested with two open, five wedge and seven sliding window prostate and head and neck intensity-modulated radiation therapy (IMRT) fields on phantoms. Results were analysed using absolute gamma analysis (3%/3 mm).

RESULTS

The open fields gamma pass rates were >96.8% for all comparisons. For wedge and IMRT fields, comparisons between predicted and TPS-computed in-phantom exit dose resulted in mean gamma pass rate of 97.4% (range, 92.3-100%). As for the comparisons between predicted and measured EPID transit dose, the mean gamma pass rate was 97.5% (range, 92.6-100%).

CONCLUSION

An EPID transit dosimetry model that can predict in-phantom exit dose and EPID transit dose was described and proven to be valid.

ADVANCES IN KNOWLEDGE

The described model is practical, generic and flexible to encourage widespread implementation of EPID dosimetry for the improvement of patients' safety in radiotherapy.

Pregnancy and helminth infections

It has been proposed that helminth infection may be particularly detrimental during pregnancy, through adverse effects on maternal anaemia and on birth outcomes, and that anthelminthic treatment during pregnancy will therefore be particularly beneficial. However, the few treatment trials that have been conducted have given, but little support to this notion and further trials in settings of nutritional stress are needed. It has also been proposed that prenatal exposure to helminth infection has an important effect on the development of the foetal immune response. There is evidence that this may impact, long-term, upon responses to helminth and nonhelminth antigens, and to allergens. Exposure to helminths in utero may also have nonspecific effects that may modify the offspring's susceptibility to diseases mediated by inflammation, including metabolic disorders. The mechanisms of such effects are not known, but they deserve to be explored as current epidemiological findings suggest the possibility of primary prevention for inflammatory conditions such as allergy, through intervention during pregnancy.

An inverse problem approach to recovery of in vivo nanoparticle concentrations from thermal image monitoring of MR-guided laser induced thermal therapy

Quantification of local variations in the optical properties of tumor tissue introduced by the presence of gold-silica nanoparticles (NP) presents significant opportunities in monitoring and control of NP-mediated laser induced thermal therapy (LITT) procedures. Finite element methods of inverse parameter recovery constrained by a Pennes bioheat transfer model were applied to estimate the optical parameters. Magnetic resonance temperature imaging (MRTI) acquired during a NP-mediated LITT of a canine transmissible venereal tumor in brain was used in the presented statistical inverse problem formulation. The maximum likelihood (ML) value of the optical parameters illustrated a marked change in the periphery of the tumor corresponding with the expected location of NP and area of selective heating observed on MRTI. Parameter recovery information became increasingly difficult to infer in distal regions of tissue where photon fluence had been significantly attenuated. Finite element temperature predictions using the ML parameter values obtained from the solution of the inverse problem are able to reproduce the NP selective heating within 5 °C of measured MRTI estimations along selected temperature profiles. Results indicate the ML solution found is able to sufficiently reproduce the selectivity of the NP mediated laser induced heating and therefore the ML solution is likely to return useful optical parameters within the region of significant laser fluence.

The ABCs of cancer stem cell drug resistance

Chemotherapy is generally effective as a non-targeted therapy in killing the majority of cells in a tumor; however, a small population of residual cells that are intrinsically resistant to such agents persist after chemotherapy, ultimately resulting in patient relapse. There is evidence that these cells within resistant tumors are cancer stem cells. A common mechanism of multidrug resistance used by residual tumor cells involves the expression of the ATP-binding cassette (ABC) transporters. Understanding the anticancer drug transport properties of these transporters, as well as their physiological functions, in addition to improved efforts to discover and characterize selective inhibitors, will lead to more effective therapeutics for oncology.

Diagnostic accuracy of a new instrument for detecting cognitive dysfunction in an emergent psychiatric population: the Brief Cognitive Screen

OBJECTIVES

In certain clinical contexts, the sensitivity of the Mini-Mental State Examination (MMSE) is limited. The authors developed a new cognitive screening instrument, the Brief Cognitive Screen (BCS), with the aim of improving diagnostic accuracy for cognitive dysfunction in the psychiatric emergency department (ED) in a quick and convenient format.

METHODS

The BCS, consisting of the Oral Trail Making Test (OTMT), animal fluency, the Clock Drawing Test (CDT), and the MMSE, was administered to 32 patients presenting with emergent psychiatric conditions. Comprehensive neuropsychological evaluation served as the criterion standard for determining cognitive dysfunction. Diagnostic accuracy of the MMSE was determined using the traditional clinical cutoff and receiver operating characteristic (ROC) curve analyses. Diagnostic accuracy of individual BCS components and BCS Summary Scores was determined by ROC analyses.

RESULTS

At the traditional clinical cutoff, MMSE sensitivity (46.4%) and total diagnostic accuracy (53.1%) were inadequate. Under ROC analyses, the diagnostic accuracy of the full BCS Summary Score (area under the curve [AUC]=0.857) was comparable to the MMSE (AUC=0.828). However, a reduced BCS Summary Score consisting of OTMT Part B (OTMT-B), animal fluency, and the CDT yielded classification accuracy (AUC=0.946) that was superior to the MMSE.

CONCLUSIONS

Preliminary findings suggest the BCS is an effective, convenient alternative cognitive screening instrument for use in emergent psychiatric populations.

Computational modeling and real-time control of patient-specific laser treatment of cancer

An adaptive feedback control system is presented which employs a computational model of bioheat transfer in living tissue to guide, in real-time, laser treatments of prostate cancer monitored by magnetic resonance thermal imaging. The system is built on what can be referred to as cyberinfrastructure-a complex structure of high-speed network, large-scale parallel computing devices, laser optics, imaging, visualizations, inverse-analysis algorithms, mesh generation, and control systems that guide laser therapy to optimally control the ablation of cancerous tissue. The computational system has been successfully tested on in vivo, canine prostate. Over the course of an 18 min laser-induced thermal therapy performed at M.D. Anderson Cancer Center (MDACC) in Houston, Texas, the computational models were calibrated to intra-operative real-time thermal imaging treatment data and the calibrated models controlled the bioheat transfer to within 5 degrees C of the predetermined treatment plan. The computational arena is in Austin, Texas and managed at the Institute for Computational Engineering and Sciences (ICES). The system is designed to control the bioheat transfer remotely while simultaneously providing real-time remote visualization of the on-going treatment. Post-operative histology of the canine prostate reveal that the damage region was within the targeted 1.2 cm diameter treatment objective.