PREdiction and Diagnosis using Imaging and Clinical biomarkers Trial in Traumatic Brain Injury (PREDICT-TBI) study protocol: an observational, prospective, multicentre cohort study for the prediction of outcome in moderate-to-severe TBI

INTRODUCTION

Traumatic brain injury (TBI) is a heterogeneous condition with a broad spectrum of injury severity, pathophysiological processes and variable outcomes. For moderate-to-severe TBI survivors, recovery is often protracted and outcomes can range from total dependence to full recovery. Despite advances in medical treatment options, prognosis remains largely unchanged. The objective of this study is to develop a machine learning predictive model for neurological outcomes at 6 months in patients with a moderate-to-severe TBI, incorporating longitudinal clinical, multimodal neuroimaging and blood biomarker predictor variables.

METHODS AND ANALYSIS

A prospective, observational, cohort study will enrol 300 patients with moderate-to-severe TBI from seven Australian hospitals over 3 years. Candidate predictors including demographic and general health variables, and longitudinal clinical, neuroimaging (CT and MRI), blood biomarker and patient-reported outcome measures will be collected at multiple time points within the acute phase of injury. The predictor variables will populate novel machine learning models to predict the Glasgow Outcome Scale Extended 6 months after injury. The study will also expand on current prognostic models by including novel blood biomarkers (circulating cell-free DNA), and the results of quantitative neuroimaging such as Quantitative Susceptibility Mapping and Dynamic Contrast Enhanced MRI as predictor variables.

ETHICS AND DISSEMINATION

Ethical approval has been obtained by the Royal Brisbane and Women's Hospital Human Research Ethics Committee, Queensland. Participants or their substitute decision-maker/s will receive oral and written information about the study before providing written informed consent. Study findings will be disseminated by peer-review publications and presented at national and international conferences and clinical networks.

TRIAL REGISTRATION NUMBER

ACTRN12620001360909.

Large multinational evaluation of time to reintervention in patients undergoing bioprosthetic valve implantation during open heart surgery

Introduction

Bioprosthetic valves are increasingly utilized during open heart surgery in favor of mechanical valves. These tissue valves are prone for structural valve degeneration and failure, especially in young patients. Transcatheter aortic valve implantation (TAVI) is an appealing approach in these patients.

Purpose

To describe independent correlates for early need for reintervention.

Method

We used a large multicenter registry of patients (>45 years of age) with failed bioprosthetic surgical valves undergoing TAVI valve-in-valve (VinV) in either aortic or the mitral positions. Early reintervention was (<5 years between open-heart surgery and VinV). Multi-variable properties that were included: patient gender, age at open-heart surgery, valve size, baseline renal failure, position of valve implantation, and bioprosthetic valve label size.

Results

A total of 3,324 patients were included in the study (age at the time of open heart surgery 68.9+7.9 years). Median time to TAVI was 9 years (IQR 6–13 years). A total of 632 (19%) patients experienced early valve degeneration with median time to TAVI of only 3 years [IQR 1–5]. Patients with early degeneration were older than those without early degeneration (mean age at surgery was 72.8±9 years vs. 68.9±8 years; p<0.001). in addition, significant linear relation between older patient age and early valve degeneration (p for trend <0.001). Re-intervention in the mitral position was more common in the group of patients with early degeneration (24.4% vs 18.2% without early degeneration; p<0.001) Patient age and mitral valve position were independently associated with increased rate of early degeneration (OR 1.09 [1.08–1.11], p<0.001; OR 1.62 [1.31–2.01]; p<0.001 respectively).

Conclusions

In this large multicenter analysis of patients undergoing TAVR for failed bioprosthetic valves we identified old patient age and mitral valve (vs. aortic) as independent correlates for early intervention. A discrepancy with known association of young age and rapid bioprosthetic valve degeneration is to be determined.

Funding Acknowledgement

Type of funding sources: None.

Autologous skin-derived neural precursor cell therapy reverses canine Alzheimer dementia-like syndrome in a proof of concept veterinary trial

BACKGROUND

Older companion dogs naturally develop a dementia-like syndrome with biological, clinical and therapeutic similarities to Alzheimer disease (AD). Given there has been no new safe, clinically effective and widely accessible treatment for AD for almost 20 years, an all-new cell therapeutic approach was trialled in canine veterinary patients, and further modelled in aged rats for more detailed neurobiological analysis.

METHODS

A Phase 1/2A veterinary trial was conducted in N = 6 older companion dogs with definitive diagnosis of Canine Cognitive Dysfunction (CCD). Treatment comprised direct microinjection of 250,000 autologous skin-derived neuroprecursors (SKNs) into the bilateral hippocampus using MRI-guided stereotaxis. Safety was assessed clinically and efficacy using the validated Canine Cognitive Dysfunction Rating Scale (CCDR) at baseline and 3-month post treatment. Intention to treat analysis imputed a single patient that had a surgical adverse event requiring euthanasia. Three dog brains were donated following natural death and histology carried out to quantify Alzheimer pathology as well as immature neurons and synapses; these were compared to a brain bank (N = 12) of untreated aged dogs with and without CCD. Further, an age-related memory dysfunction rat model (N = 16) was used to more closely evaluate intrahippocampal engraftment of canine SKN cells, focusing on mnemonic and synaptic effects as well as donor cell survival, neurodifferentation and electrophysiologic circuit integration in a live hippocampal slice preparation.

RESULTS

Four out-of-five dogs improved on the primary clinical CCDR endpoint, three fell below diagnostic threshold, and remarkably, two underwent full syndromal reversal lasting up to 2 years. At post mortem, synaptic density in the hippocampus specifically was nine standard deviations above non-treated dogs, and intensity of new neurons also several fold higher. There was no impact on AD pathology or long-term safety signals. Modelling in aged rats replicated the main canine trial findings: hippocampally-dependent place memory deficits were reversed and synaptic depletion rescued. In addition, this model confirmed donor cell survival and migration throughout the hippocampus, neuronal differentiation in situ, and physiologically-correct integration into pyramidal layer circuits.

CONCLUSIONS

With further development, SKN cell therapy may have potential for treating carefully chosen AD patients based on neurosynaptic restoration in the hippocampus.

Prognostic value of early leukocyte fluctuations for recovery from traumatic spinal cord injury

BACKGROUND

Acute traumatic spinal cord injury (SCI) induces a systemic immune response involving circulating white blood cells (WBCs). How this response is influenced by overall trauma severity, the neurological level of injury and/or correlates with patient outcomes is poorly understood. The objective of this study was to identify relationships between early changes in circulating WBCs, injury characteristics and long-term patient outcomes in individuals with traumatic SCI.

METHODS

We retrospectively analysed data from 161 SCI patients admitted to Brisbane's Princess Alexandra Hospital (exploration cohort). Logistic regression models in conjunction with receiver operating characteristic (ROC) analyses were used to assess the strength of specific links between the WBC response, respiratory infection incidence and neurological outcomes (American Spinal Injury Association Impairment Scale (AIS) grade conversion). An independent validation cohort from the Trauma Hospital Berlin, Germany (n = 49) was then probed to assess the robustness of effects and disentangle centre effects.

RESULTS

We find that the extent of acute neutrophilia in human SCI patients is positively correlated with New Injury Severity Scores but inversely with the neurological outcome (AIS grade). Multivariate analysis demonstrated that acute SCI-induced neutrophilia is an independent predictor of AIS grade conversion failure, with an odds ratio (OR) of 4.16 and ROC area under curve (AUC) of 0.82 (P < 0.0001). SCI-induced lymphopenia was separately identified as an independent predictor of better recovery (OR = 24.15; ROC AUC = 0.85, P < 0.0001). Acute neutrophilia and increased neutrophil-lymphocyte ratios were otherwise significantly associated with respiratory infection presentation in both patient cohorts.

CONCLUSIONS

Our findings demonstrate the prognostic value of modelling early circulating neutrophil and lymphocyte counts with patient characteristics for predicting the longer term recovery after SCI.

Complement receptor C3aR1 controls neutrophil mobilization following spinal cord injury through physiological antagonism of CXCR2

Traumatic spinal cord injury (SCI) triggers an acute-phase response that leads to systemic inflammation and rapid mobilization of bone marrow (BM) neutrophils into the blood. These mobilized neutrophils then accumulate in visceral organs and the injured spinal cord where they cause inflammatory tissue damage. The receptor for complement activation product 3a, C3aR1, has been implicated in negatively regulating the BM neutrophil response to tissue injury. However, the mechanism via which C3aR1 controls BM neutrophil mobilization, and also its influence over SCI outcomes, are unknown. Here, we show that the C3a/C3aR1 axis exerts neuroprotection in SCI by acting as a physiological antagonist against neutrophil chemotactic signals. We show that C3aR1 engages phosphatase and tensin homolog (PTEN), a negative regulator of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, to restrain C-X-C chemokine receptor type 2-driven BM neutrophil mobilization following trauma. These findings are of direct clinical significance as lower circulating neutrophil numbers at presentation were identified as a marker for improved recovery in human SCI. Our work thus identifies C3aR1 and its downstream intermediary, PTEN, as therapeutic targets to broadly inhibit neutrophil mobilization/recruitment following tissue injury and reduce inflammatory pathology.

Genetic and treatment-related risk factors associated with external apical root resorption (EARR) concurrent with orthodontia

OBJECTIVE

As genetic variation accounts for two-thirds of the variation in external apical root resorption (EARR) concurrent with orthodontic treatment, we analyzed the association of selected genetic and treatment-related factors with EARR concurrent with orthodontic treatment.

SETTING AND SAMPLE POPULATION

This case-control study of 134 unrelated, orthodontically treated Caucasian individuals was conducted in part at an Indiana Private Practice, Indiana University and the University of Kentucky.

METHODS

Utilizing a research data bank containing information from ~1450 orthodontically treated patients, pre- and post-treatment radiographs from 460 individuals were evaluated for EARR of the four permanent maxillary incisors. Sixty-seven unrelated Caucasians with moderate to severe EARR were identified and were age-/sex-matched with orthodontically treated Caucasian controls yielding 38 females and 29 males per group. Factors tested for an association with EARR included the following: 1) treatment duration, 2) extraction of maxillary premolars, 3) numerous cephalometric measurements, and 4) DNA polymorphisms within/near candidate genes in a pathway previously implicated in EARR such as the purinergic-receptor-P2X, ligand-gated ion channel 7 (P2RX7; rs208294, rs1718119, and rs2230912), caspase-1 (CASP1; rs530537, rs580253, and rs554344), interleukin-1 beta (IL1B; rs1143634), interleukin-1 alpha (IL1A; rs1800587), and interleukin-1 receptor antagonist (IL1RA; rs419598) genes. Stepwise logistic regression was utilized to identify the factors significantly associated (significance taken at or less than the layered Bonferroni correction alpha) with the occurrence of EARR.

RESULTS

A long length of treatment and the presence of specific genotypes for P2RX7 SNP rs208294 were significantly associated with EARR.

CONCLUSION

EARR occurrence was associated with both genetic and treatment-related variables, which together explained 25% of the total variation associated with EARR in the sample tested.

Knee arthroscopy routines and practice

PURPOSE

Knee arthroscopy is one of most commonly performed day-case orthopaedic procedures, thus consuming huge medical resources. The aim of the present questionnaire survey was to study knee arthroscopy routines and practice.

METHODS

An electronic web-based survey including questions around pre-, per- and postoperative routines for elective knee arthroscopy was send to all orthopaedic units associated to the Swedish Arthroscopic Society (n = 60).

RESULTS

Responses covering 37 centres out of 60 (response rate 62%) were returned. Preoperative radiograph routines varied considerable between centres; conventional radiograph varied between 5 and 100% and preoperative MRI between 5 and 80% of patients. General anaesthesia was the preferred intra-operative technique used in all centres (median 79% of patients), local anaesthesia with or without light sedation was used in all 28 out of the 37 centres responding (median 10% of cases) and spinal anaesthesia was used in 15 centres (median 5% of cases). Intra-articular local anaesthesia was provided in all but one of centres. Perioperative administration of oral NSAIDs was common (31 out 37), 6 centres (all teaching hospitals) did not routinely give pre- or postoperative NSAID. Analgesic prescription was provided on a regular base in 18 (49%) of centres; an NSAID being the most commonly prescribed. All but one centre provided written information and instruction at discharge. Referral to physiotherapy, prescribed sick leave and scheduled follow-up in the outpatient clinic diverged considerably.

CONCLUSION

Routines and practice associated to elective knee arthroscopy differed; however, no clear differences in practice were seen between teaching centres, general or local hospitals apart from a lower usage of NSAID for perioperative analgesia. There is an obvious room for further standardisation in the routine handling of patients undergoing elective arthroscopy of the knee.

Phase III, randomized, double-blind study of elesclomol and paclitaxel versus paclitaxel alone in stage IV metastatic melanoma (MM)

LBA9012

Background: Elesclomol is an investigational first-in-class oxidative stress inducer that increases oxidative stress in cancer cells leading to mitochondria-induced apoptosis. Methods: Patients (pts) with Stage IV MM, no prior chemotherapy, LDH μ 2× ULN were randomized (1:1) to either 213 mg/m2 elesclomol in combination with 80 mg/m2 paclitaxel (ELPAC) or 80 mg/m2 paclitaxel alone (P); both were given weekly ×3 followed by 1 week rest until disease progression. Pts were stratified by prior non-cytotoxic treatment, M1 grade, and LDH. The primary endpoint was PFS with >90% power to detect a 2-month improvement. The primary PFS analysis was planned once all pts had been enrolled and at least 164 PFS events had occurred. Results: 651 pts were enrolled between September 2007 and February 2009. Prognostic factors were generally well balanced. PFS analysis was based on investigator assessment of 411 pts (219 events). Median PFS was 3.5 m (95% CI 2.7–3.7) in ELPAC and 1.9 m (95% CI 1.9–3.3) in P [HR 0.88; 95% CI 0.67–1.16, p=0.3695]. The median number of cycles was 3 in ELPAC and 2 in P. Safety analysis showed increased signals on ELPAC including increased ≥Gr 3 AEs (N=405, 32.8% vs. 23.5%), increased AEs leading to death (N=405, 3.5% vs <1%) and increased overall deaths (N=651, 80 vs 53; 80% censored). Most common AEs in ELPAC were fatigue (32.8%), alopecia (31.3%) and nausea (27.9%). Conclusions: There was an improvement in PFS in the ELPAC arm, but it did not achieve statistical significance. In February 2009, the study was halted based on the recommendation of the DMC to unblind the study after the DMC observed increased deaths on the ELPAC arm. The DMC could not determine whether the observed increased deaths were treatment related or not. Of note, in this analysis there were no specific target organ toxicities attributable to ELPAC that could explain the imbalance of deaths. OS data continues to be collected to determine if the observed imbalance in OS persists as the data mature.

[Table: see text]

Phase III, randomized, double-blind study of elesclomol and paclitaxel versus paclitaxel alone in stage IV metastatic melanoma (MM)

LBA9012

The full, final text of this abstract will be available in Part II of the 2009 ASCO Annual Meeting Proceedings, distributed onsite at the Meeting on May 30, 2009, and as a supplement to the June 20, 2009, issue of the Journal of Clinical Oncology.

[Table: see text]

Models of the pulsatile hydrodynamics of cerebrospinal fluid flow in the normal and abnormal intracranial system

Images obtained from magnetic resonance imaging have helped to ascertain that both the cerebrospinal fluid (CSF) and brain move in a pulsatile manner within the cranium. However, these images are not able to reveal any quantitative information on the physiological forces that are associated with pulsatile motion. Understanding both the pressure and velocity flow field of CSF in the ventricles is important to help understand the mechanics of hydrocephalus. Four separate fluid structure interaction models of the ventricular system in the sagittal plane were created for this purpose. The first model was of a normal brain. The second and third models were pathological brain models with aqueductal stenosis at various locations along the fluid pathway. The fourth model was of a hydrocephalic brain. Results revealed the hydrodynamics of CSF pulsatile flow in the ventricles of these models. Most importantly, it has also revealed the different changes in CSF pulsatile hydrodynamics caused by the various locations of fluid flow obstructions.

Subgroup analysis of efficacy and safety analysis of a randomized, double-blinded controlled phase II study of STA-4783 in combination with paclitaxel in patients with metastatic melanoma

8528

Background: STA-4783 (S), an inducer of heat shock protein 70 (hsp70) is a bis-thiobenzoylhydrazide compound. S leads to up-regulation of hsp70 in tumor cell lines. Xenograft models of solid tumors showed synergistic anti-tumor activity in combination with paclitaxel (P). The combination P + S, in phase I and II studies, showed dose-related hsp70 induction (evidence of biological activity) and tolerability. Methods: Eligibility was based on a diagnosis of metastatic cutaneous melanoma, ECOG <=2, and prior treatment with 1 or no chemotherapy regimens. A total of 81 patients (pts) were randomized 2:1 (P 80 mg/m2 + S 213 mg/m2:P 80 mg/m2) 3 weeks out of 4 at 21 US clinical sites. The primary endpoint was progression free survival (PFS); secondary endpoints were response rate (RR), and adverse events (AEs). Results: Based on intent-to-treat analysis, the median PFS was 3.68 months (m) for P + S vs. 1.84 m in the P only arm (p=.035). RR was 15.1% in the P + S arm and 3.6% in the P arm. Subgroup analysis showed chemo- naive pts (n=23) with P + S showed a median PFS of 8.28 m vs. 2.40 in the P arm (n=9). For pts with 1 prior chemotherapy, (n=29), PFS on P + S was 3.12 m vs. 1.77 m on P (n=19). Of 19 pts who crossed over at progression, data are available for 14. PFS ranged from 0.72 to 5.5 m. Three of the 14 evaluable pts treated with P alone had rapid progression (0.95, 1.6, and 1.7 m) then significant inversion of the time to progression with the addition of S to P (2.3, 5.5, and 4.2 m) suggesting study drug effect. Scans were done at identical intervals (8 weeks). The proportion of pts with AEs of grade 3 or higher was 54% (n=52) in the P + S group and 57% in the P group (n=28); pts on P received a median of 2 cycles, while pts in the P + S group received a median of 4. Adverse events leading to discontinuation were low in both groups: 10% for the P + S, and 14% for P. Conclusions: The addition of S to P showed an increase in PFS vs. P alone particularly in chemo-naïve pts. A few pts failing single agent P appeared to benefit from P + S. Despite the additional treatment duration in the P + S group the drugs were well- tolerated, and showed mainly P related adverse events. A phase III study is planned to confirm a role for P + S in metastatic melanoma.

[Table: see text]

The placebo effect in irritable bowel syndrome trials: a meta-analysis

BACKGROUND

Despite the apparent high placebo response rate in randomized placebo-controlled trials (RCT) of patients with irritable bowel syndrome (IBS), little is known about the variability and predictors of this response.

OBJECTIVES

To describe the magnitude of response in placebo arms of IBS clinical trials and to identify which factors predict the variability of the placebo response.

METHODS

We performed a meta-analysis of published, English language, RCT with 20 or more IBS patients who were treated for at least 2 weeks. This analysis is limited to studies that assessed global response (improvement in overall symptoms). The variables considered as potential placebo modifiers were study design, study duration, use of a run-in phase, Jadad score, entry criteria, number of office visits, number of office visits/study duration, use of diagnostic testing, gender, age and type of medication studied.

FINDINGS

Forty-five placebo-controlled RCTs met the inclusion criteria. The placebo response ranged from 16.0 to 71.4% with a population-weighted average of 40.2%, 95% CI (35.9-44.4). Significant associations with lower placebo response rates were fulfillment of the Rome criteria for study entry (P=0.049) and an increased number of office visits (P=0.026).

CONCLUSIONS

Placebo effects in IBS clinical trials measuring a global outcome are highly variable. Entry criteria and number of office visits are significant predictors of the placebo response. More stringent entry criteria and an increased number of office visits appear to independently decrease the placebo response.

The placebo effect in irritable bowel syndrome trials: a meta-analysis

BACKGROUND

Despite the apparent high placebo response rate in randomized placebo-controlled trials (RCT) of patients with irritable bowel syndrome (IBS), little is known about the variability and predictors of this response.

OBJECTIVES

To describe the magnitude of response in placebo arms of IBS clinical trials and to identify which factors predict the variability of the placebo response.

METHODS

We performed a meta-analysis of published, English language, RCT with 20 or more IBS patients who were treated for at least 2 weeks. This analysis is limited to studies that assessed global response (improvement in overall symptoms). The variables considered as potential placebo modifiers were study design, study duration, use of a run-in phase, Jadad score, entry criteria, number of office visits, number of office visits/study duration, use of diagnostic testing, gender, age and type of medication studied.

FINDINGS

Forty-five placebo-controlled RCTs met the inclusion criteria. The placebo response ranged from 16.0 to 71.4% with a population-weighted average of 40.2%, 95% CI (35.9-44.4). Significant associations with lower placebo response rates were fulfillment of the Rome criteria for study entry (P=0.049) and an increased number of office visits (P=0.026).

CONCLUSIONS

Placebo effects in IBS clinical trials measuring a global outcome are highly variable. Entry criteria and number of office visits are significant predictors of the placebo response. More stringent entry criteria and an increased number of office visits appear to independently decrease the placebo response.

Frequency tuning of input-output relation in a rat cortical neuron in-vitro

The input-output relation of a single neuron stands at the basis of every biologically oriented description of the brain. This report shows that the input-output relation of cultured cortical neurons is non-linearly tuned by the input frequency. Increasing the rate of stimulation results in the appearance of ordered temporal firing patterns, which are qualitatively different for different input frequencies. The experimental results of this study lead to the conclusion that frequency tuning of neuronal input-output relation arises from activity-dependent rates at the molecular level underlying the mechanism of excitability itself.

Aural-pharyngeal polyps associated with Cryptosporidium infection in three iguanas (Iguana iguana)

Cryptosporidium spp. infection was associated with aural-pharyngeal polyps in three iguanas (Iguana iguana). All iguanas were presented for masses protruding from the ear canal, and the disease was characterized by a chronic clinical course. The masses consisted of nests of cystic glands surrounded by abundant fibrous connective tissue and lined by hyperplastic cuboidal to pseudostratified columnar epithelium that was moderately to heavily colonized by cryptosporidial organisms. Electron microscopy revealed that the majority of organisms were trophozoites.