Impact of Flexible Circuit Bonding and System Integration on Energy Resolution of Cross-Strip CZT Detectors

Cadmium zinc telluride (CZT) detectors enable high spatial resolution and high detection efficiency and are utilized for many gamma-ray and X-ray spectroscopy applications. In this article, we describe a stable bonding process and report on the characterization of cross-strip CZT detectors before and after bonding to flexible circuit. The bonding process utilizes gold stud bonding and polymer epoxy technique to bond the flexible circuits to two CZT crystals and form a detector module in an anode-cathode-cathode-anode (ACCA) configuration. The readout electronics is optimized in terms of shaper setting and steering electrode voltage. The average full-width half maximum (FWHM) energy resolution at 662 keV of 110 CZT crystals tested individually was 3.5% ± 0.59% and 4.75% ± 0.48% prebonded and post-bonded, respectively. No depth correction was performed in this study. The average FWHM energy resolution at 662 keV of the scaled-up system with 80 CZT crystals was 4.40% ± 0.53%, indicating the scaled-up readout electronics and stacking of the modules does not deteriorate performance. The proper shielding and grounding of the scaled-up system slightly improved the system-wide performance. The FWHM energy resolution at 511 keV of the scaled-up system was 5.85% ± 0.73%.

Controlling Intramolecular Interactions in the Design of Selective, High-Affinity Ligands for the CREBBP Bromodomain

CREBBP (CBP/KAT3A) and its paralogue EP300 (KAT3B) are lysine acetyltransferases (KATs) that are essential for human development. They each comprise 10 domains through which they interact with >400 proteins, making them important transcriptional co-activators and key nodes in the human protein–protein interactome. The bromodomains of CREBBP and EP300 enable the binding of acetylated lysine residues from histones and a number of other important proteins, including p53, p73, E2F, and GATA1. Here, we report a work to develop a high-affinity, small-molecule ligand for the CREBBP and EP300 bromodomains [(−)-OXFBD05] that shows >100-fold selectivity over a representative member of the BET bromodomains, BRD4(1). Cellular studies using this ligand demonstrate that the inhibition of the CREBBP/EP300 bromodomain in HCT116 colon cancer cells results in lowered levels of c-Myc and a reduction in H3K18 and H3K27 acetylation. In hypoxia (<0.1% O₂), the inhibition of the CREBBP/EP300 bromodomain results in the enhanced stabilization of HIF-1α.

Cross-Contamination on Atypical Surfaces and Venues in Food Service Environments

ABSTRACT

Cross-contamination of raw food to other surfaces, hands, and foods is a serious issue in food service. With individuals eating more meals away from home, contracting a foodborne illness from a food service establishment is an increasing concern. However, most studies have concentrated on hands or food contact surfaces and neglected atypical and unusual surfaces (surfaces that are not typically identified as a source of cross-contamination) and venues. This review was conducted to identify atypically cross-contaminated surfaces and atypical venues where cross-contamination could occur that have not been examined thoroughly in the literature. Most surfaces that could be at risk for cross-contamination are frequently touched, are rarely cleaned and sanitized, and can support the persistence and/or growth of foodborne pathogens. These surfaces include menus, spice and condiment containers, aprons and coveralls, mobile devices and tablets, and money. Venues that are explored, such as temporary events, mobile vendors, and markets, are usually limited in space or infrastructure, have low compliance with proper hand washing, and provide the opportunity for raw and ready-to-eat foods to come into contact with one another. These factors create an environment in which cross-contamination can occur and potentially impact food safety. A more comprehensive cleaning and sanitizing regime encompassing these surfaces and venues could help mitigate cross-contamination. This review highlights key surfaces and venues that have the potential to be cross-contaminated and have been underestimated or not fully investigated. These knowledge gaps indicate where further work is needed to fully understand the role of these surfaces and venues in cross-contamination and how it can be prevented.

HIGHLIGHTS

Dynamic individual vital sign trajectory early warning score (DyniEWS) versus snapshot national early warning score (NEWS) for predicting postoperative deterioration

Aims

International early warning scores (EWS) including the additive National Early Warning Score (NEWS) and logistic EWS currently utilise physiological snapshots to predict clinical deterioration. We hypothesised that a dynamic score including vital sign trajectory would improve discriminatory power.

Methods

Multicentre retrospective analysis of electronic health record data from postoperative patients admitted to cardiac surgical wards in four UK hospitals. Least absolute shrinkage and selection operator-type regression (LASSO) was used to develop a dynamic model (DyniEWS) to predict a composite adverse event of cardiac arrest, unplanned intensive care re-admission or in-hospital death within 24 h.

Results

A total of 13,319 postoperative adult cardiac patients contributed 442,461 observations of which 4234 (0.96%) adverse events in 24 h were recorded. The new dynamic model (AUC = 0.80 [95% CI 0.78−0.83], AUPRC = 0.12 [0.10−0.14]) outperforms both an updated snapshot logistic model (AUC = 0.76 [0.73−0.79], AUPRC = 0.08 [0.60−0.10]) and the additive National Early Warning Score (AUC = 0.73 [0.70−0.76], AUPRC = 0.05 [0.02−0.08]). Controlling for the false alarm rates to be at current levels using NEWS cut-offs of 5 and 7, DyniEWS delivers a 7% improvement in balanced accuracy and increased sensitivities from 41% to 54% at NEWS 5 and 18% to –30% at NEWS 7.

Conclusions

Using an advanced statistical approach, we created a model that can detect dynamic changes in risk of unplanned readmission to intensive care, cardiac arrest or in-hospital mortality and can be used in real time to risk-prioritise clinical workload.

Heterozygous CAPN3 missense variants causing autosomal-dominant calpainopathy in seven unrelated families

AIMS

Recessive variants in CAPN3 gene are the cause of the commonest form of autosomal recessive limb girdle muscle dystrophy. However, two distinct in-frame deletions in CAPN3 (NM_000070.3:c.643_663del21 and c.598_621del15) and more recently, Gly445Arg and Arg572Pro substitutions have been linked to autosomal dominant (AD) forms of calpainopathy. We report 21 affected individuals from seven unrelated families presenting with an autosomal dominant form of muscular dystrophy associated with five different heterozygous missense variants in CAPN.

METHODS

We have used massively parallel gene sequencing (MPS) to determine the genetic basis of a dominant form of limb girdle muscular dystrophy in affected individuals from seven unrelated families.

RESULTS

The c.700G> A, [p.(Gly234Arg)], c.1327T> C [p.(Ser443Pro], c.1333G> A [p.(Gly445Arg)], c.1661A> C [p.(Tyr554Ser)] and c.1706T> C [p.(Phe569Ser)] CAPN3 variants were identified. Affected individuals presented in young adulthood with progressive proximal and axial weakness, waddling walking and scapular winging or with isolated hyperCKaemia. Muscle imaging showed fatty replacement of paraspinal muscles, variable degrees of involvement of the gluteal muscles, and the posterior compartment of the thigh and minor changes at the mid-leg level. Muscle biopsies revealed mild myopathic changes. Western blot analysis revealed a clear reduction in calpain 3 in skeletal muscle relative to controls. Protein modelling of these variants on the predicted structure of calpain 3 revealed that all variants are located in proximity to the calmodulin-binding site and are predicted to interfere with proteolytic activation.

CONCLUSIONS

We expand the genotypic spectrum of CAPN3-associated muscular dystrophy due to autosomal dominant missense variants.

Hemostasis Checklist Reduces Bleeding and Blood Product Consumption After Cardiac Surgery

BACKGROUND

Considerable mediastinal bleeding is a recognized complication after cardiac surgery and may require reexploration and blood product transfusion, both of which are associated with inferior clinical outcomes with greater morbidity and mortality. The aim of this study was to develop a hemostasis checklist, with the intention of reducing mediastinal bleeding after cardiac surgery.

METHODS

A hemostasis checklist was developed with multidisciplinary collaboration. It contains 2 components: a series of surgical sites and factors affecting coagulation status. The checklist is performed at a time-out before sternal wire insertion. Analysis compared outcomes for patients undergoing cardiac surgery in the 1 year before and 2 years after implementation.

RESULTS

A total of 5542 patients underwent surgery during the study. After we implemented the checklist, there was a significant reduction in the reexploration rate (3.5% versus 1.9%; P < .001) and the proportion of patients bleeding greater than 1 L in 12 hours (6.1% versus 2.8%; P < .001). There was a major reduction in consumption of blood products, saving $430,513. There was progressive improvement in the second year after implementation. Checklist implementation was also associated with reduced intensive care unit and hospital length of stay, adding to the financial benefit.

CONCLUSIONS

Implementation of a simple and quickly performed hemostasis checklist has had a sustained impact over the 2 years after implementation, reducing the incidence of noteworthy mediastinal bleeding and reexploration, which has resulted in a major reduction in blood product consumption. Together, these have resulted in an associated reduction in intensive care unit and hospital length of stay, and a considerable financial savings. This highlights that perioperative bleeding is a preventable complication.

Reduced re-exploration and blood product transfusion after the introduction of the Papworth haemostasis checklist†

OBJECTIVES

Between 2% and 8% of patients return to the theatre for mediastinal bleeding following cardiac surgery. In the majority of patients, a surgical source of bleeding is identified. Both mediastinal bleeding and re-exploration are associated with increased morbidity and mortality and the use of blood products. The aim of this study was to develop a 'haemostasis checklist' with the intention of reducing mediastinal bleeding and re-exploration following cardiac surgery.

METHODS

The Papworth haemostasis checklist was developed with a multidisciplinary collaboration. It consists of 2 components: surgical sites and coagulation status. The checklist is completed at a 'time-out' prior to sternal wire insertion. The analysis compared the outcomes of patients undergoing cardiac surgery in the 1 year before and after implementation. A propensity analysis assessed the impact of re-exploration on outcomes.

RESULTS

Three thousand eight hundred and eleven patients underwent cardiac surgery during the study period. Re-exploration for bleeding was associated with inferior outcomes. Following checklist implementation, there was a significant reduction in the re-exploration rate (3.47% vs 2.08%, P = 0.01) and proportion of patients bleeding >1 l in 12 h (6.1% vs 3.49%, P < 0.001). There was a significant reduction in consumption of blood products saving £102 165 ($134 198). The checklist implementation was associated with reduced intensive care unit length of stay and hospital length of stay, adding to the financial benefit.

CONCLUSIONS

The haemostasis checklist represents a simple intervention which is quick and easy to use but has had a substantial impact on clinical outcomes. We have observed a significant reduction in the mediastinal blood loss, return-to-theatre rate and consumption of blood products, which is associated with a significant clinical and financial benefit.

Selective Fragments for the CREBBP Bromodomain Identified from an Encoded Self-assembly Chemical Library

DNA-encoded chemical libraries (DECLs) are collections of chemical moieties individually coupled to distinctive DNA barcodes. Compounds can be displayed either at the end of a single DNA strand (i. e., single-pharmacophore libraries) or at the extremities of two complementary DNA strands (i. e., dual-pharmacophore libraries). In this work, we describe the use of a dual-pharmacophore encoded self-assembly chemical (ESAC) library for the affinity maturation of a known 4,5-dihydrobenzodiazepinone ring (THBD) acetyl-lysine (KAc) mimic for the cyclic-AMP response element binding protein (CREB) binding protein (CREBBP or CBP) bromodomain. The new pair of fragments discovered from library selection showed a sub-micromolar affinity for the CREBBP bromodomain in fluorescence polarization and ELISA assays, and selectivity against BRD4(1).

Chronic lung disease in adult recurrent tuberculosis survivors in Zimbabwe: a cohort study

OBJECTIVE

To examine the prevalence and magnitude of chronic lung disease (CLD) and its association with empiric anti-tuberculosis treatment (due to lack of bacteriologic confirmation) among recurrent tuberculosis (TB) survivors in a human immunodeficiency virus (HIV) prevalent setting.

METHODS

Prospective cohort study of retreatment TB survivors in Harare, Zimbabwe. At median follow-up of 2 years post-treatment initiation, we characterized mortality, respiratory impairment, and mental health.

RESULTS

Among 175 retreatment TB survivors, 65% of whom were HIV-positive and 21% had been empirically treated, multiparameter CLD was noted at follow-up among 14% of patients (95%CI 9.0-19.7), with a six-fold increase in age-adjusted death in the first year following treatment completion. Empirically treated TB (relative risk [RR] 3.4, 95%CI 1.4-8.3) was associated with CLD, as was the number of previous anti-tuberculosis treatment courses in dose-dependent fashion (three vs. one, RR 6.2, 95%CI 1.7-22.1). Among retreatment TB survivors, 33% (95%CI 26.0-40.1) had persistent respiratory symptoms (Chronic Obstructive Pulmonary Disease Assessment Test score 10); 26% (95%CI 19.8-33.0) significant deficits in exercise capacity (median incremental shuttle walk test distance, 550 m; Q₁-Q₃ 440-730 m); 83% (95%CI 75.7-89.7) residual radiographic abnormalities on chest X-ray; 12% (95%CI 6.6-16.1%) moderate-to-severe obstruction on spirometry; and 13% (95%CI 7.6-17.5%) major depression.

CONCLUSIONS

Despite successful treatment, retreatment TB survivors retain a substantial risk of morbidity and mortality.

A change in perspective to see the bigger picture. A thematic analysis of Audit and Quality Improvement submissions to the last seven UK based SAM Conferences

AIMS

To create a profile of Society for Acute Medicine (SAM) Audit and Quality Improvement (A&QI) accepted abstracts from the last seven UK based conferences.

METHODOLOGY

The profile elements for 380 SAM A&QI abstracts accepted for poster presentation were compiled from their respective conference programme booklets. Abstracts were classified into 30 categories based on key themes. Further sub-categorisation of abstracts was based on secondary detail of the submissions. Data was analysed with Pareto charts.

FINDINGS

The majority of submissions were covered by a small representation of themes, with 30% of category themes covering 80% of A&QI abstracts. There is a repetitive trend of theme categories across all the conferences.

Acute kidney injury after thoracic surgery: a proposal for a multicentre evaluation (MERITS)

OBJECTIVES

Because the mortality rate is very low in thoracic surgery, its use as a quality discriminator is limited. Acute kidney injury (AKI) is a candidate measure because it is associated with increased rates of morbidity and mortality and is partly preventable. The incidence of AKI after thoracic surgery is not well documented. We conducted an audit to determine the incidence and outcomes of AKI. This audit became a pilot project, and the results indicate the feasibility of a larger study.

METHODS

Retrospective data on renal function post-thoracic surgery were collected at a tertiary cardiothoracic unit over 12 months. Renal impairment was classified according to the Kidney Disease Improving Global Outcomes criteria.

RESULTS

Of 568 patients (mean = 59  ±  SD 18; 38% women), AKI was diagnosed in 86 (15.1%) within 72 h post-thoracic surgery based on the Kidney Disease Improving Global Outcomes staging system (stage 1, n = 55; stage 2, n = 25; stage 3, n = 6). Significant differences were found in postoperative length of stay (3 vs 5 days; P < 0.001) of patients with and without AKI. There was a significant difference between the age groups of patients with and without AKI (P < 0.05) in the open surgical group but not in the group having video-assisted thoracoscopic surgery (VATS). There was no significant difference in the mortality rates between patients with and without AKI.

CONCLUSIONS

The incidence of AKI after thoracic surgery was 15.1%. AKI was associated with longer hospital stays and was more likely in ≥60-year-old patients after open surgery than after VATS. Reducing AKI could improve patient outcomes. We propose that AKI may be a useful quality measure in thoracic surgery. We are developing a multicentre audit based on this approach.

Logistic early warning scores to predict death, cardiac arrest or unplanned intensive care unit re-admission after cardiac surgery

NHS England recently mandated that the National Early Warning Score of vital signs be used in all acute hospital trusts in the UK despite limited validation in the postoperative setting. We undertook a multicentre UK study of 13,631 patients discharged from intensive care after risk‐stratified cardiac surgery in four centres, all of which used VitalPAC^TM to electronically collect postoperative National Early Warning Score vital signs. We analysed 540,127 sets of vital signs to generate a logistic score, the discrimination of which we compared with the national additive score for the composite outcome of: in‐hospital death; cardiac arrest; or unplanned intensive care admission. There were 578 patients (4.2%) with an outcome that followed 4300 sets of observations (0.8%) in the preceding 24 h: 499 out of 578 (86%) patients had unplanned re‐admissions to intensive care. Discrimination by the logistic score was significantly better than the additive score. Respective areas (95%CI) under the receiver‐operating characteristic curve with 24‐h and 6‐h vital signs were: 0.779 (0.771–0.786) vs. 0.754 (0.746–0.761), p < 0.001; and 0.841 (0.829–0.853) vs. 0.813 (0.800–0.825), p < 0.001, respectively. Our proposed logistic Early Warning Score was better than the current National Early Warning Score at discriminating patients who had an event after cardiac surgery from those who did not.

Covalent Chemical Cochaperones of the p300/CBP GACKIX Domain

The GACKIX activator binding domain has been a compelling target for small-molecule probe discovery because of the central role of activator-GACKIX complexes in diseases ranging from leukemia to memory disorders. Additionally, GACKIX is an ideal model to dissect the context-dependent function of activator-coactivator complexes. However, the dynamic and transient protein-protein interactions (PPIs) formed by GACKIX are difficult targets for small molecules. An additional complication is that activator-binding motifs, such as GACKIX, are found in multiple coactivators, making specificity difficult to attain. In this study, we demonstrate that the strategy of tethering can be used to rapidly discover highly specific covalent modulators of the dynamic PPIs between activators and coactivators. These serve as both ortho- and allosteric modulators, enabling the tunable assembly or disassembly of the activator-coactivator complexes formed between the KIX domain and its cognate activator binding partners MLL and CREB. The molecules maintain their function and selectivity, even in human cell lysates and in bacterial cells, and thus, will ultimately be highly useful probes for cellular studies.

BET bromodomain ligands: Probing the WPF shelf to improve BRD4 bromodomain affinity and metabolic stability

Ligands for the bromodomain and extra-terminal domain (BET) family of bromodomains have shown promise as useful therapeutic agents for treating a range of cancers and inflammation. Here we report that our previously developed 3,5-dimethylisoxazole-based BET bromodomain ligand (OXFBD02) inhibits interactions of BRD4(1) with the RelA subunit of NF-κB, in addition to histone H4. This ligand shows a promising profile in a screen of the NCI-60 panel but was rapidly metabolised (t½ = 39.8 min). Structure-guided optimisation of compound properties led to the development of the 3-pyridyl-derived OXFBD04. Molecular dynamics simulations assisted our understanding of the role played by an internal hydrogen bond in altering the affinity of this series of molecules for BRD4(1). OXFBD04 shows improved BRD4(1) affinity (IC50 = 166 nM), optimised physicochemical properties (LE = 0.43; LLE = 5.74; SFI = 5.96), and greater metabolic stability (t½ = 388 min).

Functional outcomes and return-to-sports rate after modified Brostrom repair for lateral ankle instability with absorbable sutures and immediate postoperative weightbearing

Category:

Sports

Introduction/Purpose:

The ankle is commonly injured in sporting activities occurring in up to 1 in 10,000 people a day. About 80% of ankle sprains recover with nonoperative management, with the remaining 20% of patients developing symptomatic instability requiring surgery. There are various surgical options being used, including anatomic repair (Brostrom technique and modifications), anatomic recon- struction with autograft or allograft, and nonanatomic reconstructions such as the Watson-Jones, Evans, and Chrisman-Snook procedures. The outcome of the direct anatomic repair is likely dependent on tissue quality, ability to tension the ligaments, and the security of the fixation. Secure fixation is critical to enable an early rehabilitation without compromising clinical outcome. We hypothesized that using absorbable suture for anatomic reconstruction is not only cost effective but also allows early rehabilitation with immediate postoperative weightbearing with good functional outcomes.

Methods:

The study included 71 patients presenting with chronic lateral ankle instability (who failed non-operative management) who underwent modified Brostrom repair by a single surgeon between Jan 2012 and Feb 2014.The anterior talofibular ligament and calcaneo- fibular ligament were anatomically repaired , and the repair was augmented with inferior extensor retinaculum proximal advancement, both with 1 vicryl suture. Full weight bearing in normal shoe was allowed from the day of surgery. Physiotherapy commenced prior to discharge from day surgery with gentle active range of motion, calf strength, and static peroneii exercises. From 3 to 4 weeks proprioceptive, theraband, and dynamic peroneal exercises were started. No boots, braces, or casts were used at any stage in the post-operative period. Patients were assessed preoperatively and at a minimum 2-year follow-up using the Foot and Ankle Outcome Score (FAOS). Complication, failure (recurrent instability), and return-to-sport rates were also recorded.

Results:

There were 41 were males and 30 females with mean age at surgery of 27 years (range 16 - 47 years), mean duration of symptoms of 2 years (range, 6 months to 8 years)and a mean follow-up duration of 34 months (range 24- 49 months). Significant improvement was seen in the FAOS from preoperatively to postoperatively (from 37 to 79): the pain subscale , the symptom subscale, the function subscale, the function in sports and recreation subscale, and the foot and ankle–related quality of life subscale improved from 38 to 79, 42 to 81, 43 to 82 , 31 to 79 and 32 to 77 respectively. All these findings were statistically significant. The failure rate was 4%, with 3 patients reporting instability after subsequent traumatic re-rupture. Two case of temporary neuropraxia of the superficial peroneal nerve was observed. Fifty four out of 71 patients were involved in sports prior to injury and forty seven (87%) returned to sport after reconstruction.

Conclusion:

This study demonstrates that lateral ligament reconstruction using absorbable sutures is an effective procedure for the treatment of chronic lateral ankle instability and allows immediate weight bearing. This allows a cost-effective approach to management with minimal impact on a patient’s activities of daily living in the post-operative period. The procedure also has high return-to-sport rate.

What are the critical steps in processing blood cultures? A prospective audit evaluating current practice of reporting blood cultures in a centralised laboratory serving secondary care hospitals

AIMS

To assess current procedures of processing positive blood cultures against national standards with an aim to evaluate its clinical impact and to determine the utility of currently available rapid identification and susceptibility tests in processing of blood cultures.

METHODS

Blood cultures from three secondary care hospitals, processed at a centralised laboratory, were prospectively audited. Data regarding processing times, communication with prescribers, changes to patient management and mortality within 30 days of a significant blood culture were collected in a preplanned pro forma for a 4-week period.

RESULTS

Of 2206 blood cultures, 211 positive blood cultures flagged positive. Sixty-nine (3.1%) of all cultures were considered to be contaminated. Fifty per cent of blood cultures that flagged positive had a Gram stain reported within 2 hours. Two (0.99%) patients with a significant bacteraemia had escalation of antimicrobial treatment at the point of reporting the Gram stain that was subsequently deemed necessary once sensitivity results were known. Most common intervention was de-escalation of therapy for Gram-positive organisms at the point of availability of pathogen identification (25.6% in Gram positive vs 10% in Gram negative; p=0.012). For Gram-negative organisms, the most common intervention was de-escalation of therapy at the point of availability of sensitivity results (43% in Gram negatives vs 17.9% in Gram positive; p=0.0097). Overall mortality within 30 days of a positive blood culture was 10.9% (23/211). Antibiotic resistance may have contributed to mortality in four of these patients (three Gram negative and one Gram positive).

CONCLUSION

Gram stain result had the least impact on antibiotic treatment interventions (escalation or de-escalation). Tests that improve identification time for Gram-positive pathogens and sensitivity time for Gram-negative pathogens had the greatest impact in making significant changes to antimicrobial treatment.

Hookworm-related cutaneous larva migrans acquired in the UK

Hookworm-related cutaneous larva migrans (HrCLM) is a skin disease caused by infection with the larvae of animal hookworms. With conditions for infection more favourable in tropical climates, HrCLM in the UK is classically diagnosed in the returning traveller. We present two cases of clinically diagnosed UK-acquired HrCLM from a district general hospital in the south of England. A 68-year-old woman presented with a pruritic serpiginous tract on the right hand. She was a keen gardener and had been handling compost. A 50-year-old man, a long distance runner, presented with a similar lesion on the dorsum of his foot. Both patients were treated with a single dose of albendazole. These cases may represent an emerging infection in the UK. In the absence of a suggestive travel history, early recognition followed by efficient access to therapy is vital for treating HrCLM transmitted in the UK.

Does kV-MV dual-energy computed tomography have an advantage in determining proton stopping power ratios in patients?

Conventional kilovoltage (kV) x-ray-based dual-energy CT (DECT) imaging using two different x-ray energy spectra is sensitive to image noise and beam hardening effects. The purpose of this study was to evaluate the theoretical advantage of the DECT method for determining proton stopping power ratios (SPRs) using a combination of kV and megavoltage (MV) x-ray energies. We investigated three representative x-ray energy pairs: 100 and 140 kVp comprised the kV-kV pair, 100 kVp and 1 MV comprised the kV-MV pair, and two 1 MV x-ray beams-one with and one without external filtration-comprised the MV-MV pair. The SPRs of 34 human tissues were determined using the DECT method with these three x-ray energy pairs. Small perturbations were introduced into the CT numbers and x-ray spectra used for the DECT calculation to simulate the effects of random noise and beam hardening. An error propagation analysis was performed on the DECT calculation algorithm to investigate the propagation of CT number uncertainty to final SPR estimation and to suggest the best x-ray energy combination. We found that the DECT method using each of the three beam pairs achieved similar accuracy in determining the SPRs of human tissues in ideal conditions. However, when CT number uncertainties and artifacts such as imaging noise and beam hardening effects were considered, the kV-MV DECT improved the accuracy of SPR estimation substantially over the kV-kV or MV-MV DECT methods. Furthermore, our error propagation analysis showed that the combination of 100 kVp and 1 MV beams was close to the optimal selection when using the DECT method to determine SPRs. Overall, the kV-MV combination makes the DECT method more robust in resolving the effective atomic numbers for biological tissues than the traditional kV-kV DECT method.

Arthroscopic treatment of osteochondral lesions of the ankle with matrix-associated chondrocyte implantation: early clinical and magnetic resonance imaging results

BACKGROUND

Conventional autologous chondrocyte transplantation in the ankle often requires tibial or fibular osteotomies with potential morbidity for the patient. Advances in biotechnology and surgical techniques have resulted in the development of matrix-associated chondrocyte implantation (MACI). As the chondrocyte-loaded scaffold can be applied arthroscopically, this procedure is especially useful for the treatment of osteochondral defects in the ankle.

HYPOTHESIS

Arthroscopic MACI is a safe procedure in the ankle with good clinical and magnetic resonance imaging results.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The authors reviewed all patients (n = 18) who had arthroscopic MACI for osteochondral lesions of the ankle (n = 19) between February 2006 and May 2008 clinically and with magnetic resonance imaging. The pain and disability module of the Foot Function Index (FFI), the American Orthopaedic Foot & Ankle Society (AOFAS) clinical rating system, the Core Scale of the Foot and Ankle Module of the American Academy of Orthopaedic Surgeons (AAOS) Lower Limb Outcomes Assessment Instruments, and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score were used. The clinical results up to 3 years after MACI (mean follow-up, 24.5 months) were compared with preoperative data for 14 cases and the magnetic resonance imaging data for all 19.

RESULTS

A significant improvement (50.3% ± 13.2%) in all clinical scores was noted (FFI pain before MACI: 5.5 ± 2.0, after MACI: 2.8 ± 2.2; FFI disability before MACI: 5.0 ± 2.3, after MACI: 2.6 ± 2.2; AOFAS before MACI: 58.6 ± 16.1, after MACI: 80.4 ± 14.1; AAOS standardized mean before MACI: 59.9 ± 16.0, after MACI: 83.5 ± 13.2; AAOS normative score before MACI: 23.0 ± 13.0, after MACI: 42.2 ± 10.7). According to the AOFAS Hindfoot score, 64% were rated as excellent and good, whereas 36% were rated fair and poor. The results correlated with the age of the patient and the duration of symptoms, but not with the size of the lesion. Sixteen patients (89%) reported regular sports activities before the onset of symptoms; 13 of them (81%) returned to sports after the MACI, 56% (n = 9) to the same level. The mean MOCART score was 62.4 ± 15.8 points. In general, there was no relation between MOCART score and clinical outcome, although the filling of the defect showed some correlation with the AAOS score.

CONCLUSION

Arthroscopic MACI is a safe procedure for the treatment of osteochondral lesions in the ankle with overall good clinical and magnetic resonance imaging results.

Arthroscopic treatment of osteochondral lesions of the ankle with matrix-associated chondrocyte implantation: early clinical and magnetic resonance imaging results

BACKGROUND

Conventional autologous chondrocyte transplantation in the ankle often requires tibial or fibular osteotomies with potential morbidity for the patient. Advances in biotechnology and surgical techniques have resulted in the development of matrix-associated chondrocyte implantation (MACI). As the chondrocyte-loaded scaffold can be applied arthroscopically, this procedure is especially useful for the treatment of osteochondral defects in the ankle.

HYPOTHESIS

Arthroscopic MACI is a safe procedure in the ankle with good clinical and magnetic resonance imaging results.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The authors reviewed all patients (n = 18) who had arthroscopic MACI for osteochondral lesions of the ankle (n = 19) between February 2006 and May 2008 clinically and with magnetic resonance imaging. The pain and disability module of the Foot Function Index (FFI), the American Orthopaedic Foot & Ankle Society (AOFAS) clinical rating system, the Core Scale of the Foot and Ankle Module of the American Academy of Orthopaedic Surgeons (AAOS) Lower Limb Outcomes Assessment Instruments, and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score were used. The clinical results up to 3 years after MACI (mean follow-up, 24.5 months) were compared with preoperative data for 14 cases and the magnetic resonance imaging data for all 19.

RESULTS

A significant improvement (50.3% ± 13.2%) in all clinical scores was noted (FFI pain before MACI: 5.5 ± 2.0, after MACI: 2.8 ± 2.2; FFI disability before MACI: 5.0 ± 2.3, after MACI: 2.6 ± 2.2; AOFAS before MACI: 58.6 ± 16.1, after MACI: 80.4 ± 14.1; AAOS standardized mean before MACI: 59.9 ± 16.0, after MACI: 83.5 ± 13.2; AAOS normative score before MACI: 23.0 ± 13.0, after MACI: 42.2 ± 10.7). According to the AOFAS Hindfoot score, 64% were rated as excellent and good, whereas 36% were rated fair and poor. The results correlated with the age of the patient and the duration of symptoms, but not with the size of the lesion. Sixteen patients (89%) reported regular sports activities before the onset of symptoms; 13 of them (81%) returned to sports after the MACI, 56% (n = 9) to the same level. The mean MOCART score was 62.4 ± 15.8 points. In general, there was no relation between MOCART score and clinical outcome, although the filling of the defect showed some correlation with the AAOS score.

CONCLUSION

Arthroscopic MACI is a safe procedure for the treatment of osteochondral lesions in the ankle with overall good clinical and magnetic resonance imaging results.

Review of the safety and efficacy of long-term NSAID use in the treatment of canine osteoarthritis

The published, peer-reviewed literature was systematically searched for information on the safety and efficacy of long-term (defined as 28 days or more of continuous therapy) NSAID use in the treatment of canine osteoarthritis. Online databases were reviewed in June 2008 and papers were selected based on their relevance. Fifteen papers were identified and evaluated. Six of seven papers indicated a benefit of long-term treatment over short-term treatment in terms of the reduction of clinical signs or lameness; one study showed no benefit. Fourteen papers evaluated safety with calculated experimental (adverse) event rates (EER) between 0 and 0.31, but there was no correlation between study length and EER (rs=-0.109, P=0.793). The balance of evidence for the efficacy of NSAIDs supports longer-term use of these agents for increased clinical effect. There is no indication in the literature that such an approach is associated with a reduction in safety, although robust data on the safety of long-term NSAID use are lacking in large numbers of dogs.

Pituitary apoplexy: retrospective review of 30 patients—is surgical intervention always necessary?

The objective of this article is to review clinical outcomes in patients presenting with pituitary apoplexy and compare the results of conservative and surgical management. It took the form of a retrospective review of 30 patients (23M, 7F; age range: 17-86 years) with pituitary apoplexy diagnosed between 1988 and 2004. Presenting features included headache in 27 patients, 'collapse' in three and vomiting in 14. Complete blindness occurred in four patients, monocular blindness in two, decreased visual acuity in 12, visual field loss in 10 and ophthalmoplegia in 15. Only five had no initial visual deficit. CT was the initial mode of imaging in 22 patients: three such scans were initially reported as 'normal' and a further 10 as pituitary tumour only, with no haemorrhage. Ten patients proceeded to early pituitary surgery and 20 were managed conservatively. There was one death 24 days after admission in a patient with multiple co-morbidities. Of the six patients with blindness, three (two conservatively treated) regained partial vision. Of the remaining 19 patients with visual deficits, 10 (two surgically treated) recovered fully and eight (four surgically treated) partly so. At latest follow-up the following pituitary hormone deficiencies were identified: ACTH 19; TSH 20; testosterone 18; ADH (diabetes insipidus) eight. Later recurrence of a pituitary adenoma was observed in seven cases (including six of the 10 surgically treated patients). There was no evidence that those patients managed surgically had a better outcome. Early neurosurgical intervention may not be required in most patients presenting with pituitary apoplexy.

Intrathecal chemotherapy delivered by a lumbar-thecal catheter in metastatic medulloblastoma: a case illustration

BACKGROUND

Medulloblastoma is the most common malignant brain tumour in children. Despite recent advances, the prognosis in high risk patients remains poor. Further improvement in survival is dependent upon the development of strategies to attack the tumour more effectively, but with less toxicity. Intrathecal chemotherapy, is an ideal but currently underused method of directly targeting residual tumour within the area of resection and the leptomeningeal disease commonly associated with this tumour.

METHOD

We describe the case of a 12 yr old child with metastatic medulloblastoma, who received intrathecal topotecan via a spinal catheter.

CONCLUSION

This method represents a simple, safe and effective method of delivering an even and widespread distribution of drug within the cerebrospinal fluid (CSF) of the neuroaxis. With new agents being identified and others in the early stages of development, intrathecal chemotherapy may emerge as an important therapeutic option to consider when faced with such challenging cases.

Tositumomab and Iodine I 131 Tositumomab for Recurrent Indolent and Transformed B-Cell Non-Hodgkin’s Lymphoma

Purpose

An open-label phase II study was conducted at two centers to establish the efficacy and safety of tositumomab and iodine I 131 tositumomab at first or second recurrence of indolent or transformed indolent B-cell lymphoma.

Patients and Methods

A single dosimetric dose was followed at 7 to 14 days by the patient-specific administered radioactivity required to deliver a total body dose of 0.75 Gy (reduced to 0.65 Gy for patients with platelets counts of 100 to 149 × 109/L). Forty of 41 patients received both infusions.

Results

Thirty-one of 41 patients (76%) responded, with 20 patients (49%) achieving either a complete (CR) or unconfirmed complete remission [CR(u)] and 11 patients (27%) achieving a partial remission. Response rates were similar in both indolent (76%) and transformed disease (71%). The overall median duration of remission was 1.3 years. The median duration of remission has not yet been reached for those patients who achieved a CR or CR(u). Eleven patients continue in CR or CR(u) between 2.6+ and 5.2+ years after therapy. Therapy was well tolerated; hematologic toxicity was the principal adverse event. Grade 3 or 4 anemia, neutropenia, and thrombocytopenia were observed in 5%, 45%, and 32% of patients, respectively. Secondary myelodysplasia has occurred in one patient. Four patients developed human antimouse antibodies after therapy. Five of 38 assessable patients have developed an elevated thyroid-stimulating hormone; treatment with thyroxine has been initiated in one patient.

Conclusion

High overall and CR rates were observed after a single dose of tositumomab and iodine I 131 tositumomab in this patient group. Toxicity was modest and easily managed.

Asking questions can help: development and preliminary evaluation of a question prompt list for palliative care patients

Question prompt lists (QPLs) have been shown to be an inexpensive and effective communication tool for patients in oncology consultations. We aimed to develop and pilot a QPL for palliative care (PC) patients. In order to identify suitable questions for inclusion in the QPL, we conducted focus groups and individual interviews with 19 patients, 24 carers and 22 PC health professionals. A further 21 health professionals reviewed the draft document. The draft QPL was piloted in 23 patients. In total, 112 questions were identified and grouped into eight categories. All participants felt that the QPL, in booklet form, could be a useful tool. Out of 23 patients in the pilot study, 22 agreed that the QPL was helpful, contained useful questions, was easy to understand and would be useful in the future. State anxiety (STAI) decreased after receiving the booklet and seeing the doctor in 16 out of 19 patients (overall anxiety decreased by a median of 8, IQR 1-13). Participants in the pilot study endorsed the inclusion of end-of-life issues in the QPL, despite some reservations expressed about this by health professionals in the individual interviews. We have identified a specific QPL that might facilitate useful dialogue between PC patients and their doctor. The QPL has strong support from patients, their carers and relevant health professionals.