Improvement in Functional Outcome from 6 to 12 Months After Moderate and Severe Traumatic Brain Injury Is Frequent, But May Not Be Detected With the Glasgow Outcome Scale Extended.

The aims of this study were (1) to report outcome and change in outcome in patients with moderate and severe traumatic brain injury (mo/sTBI) between 6 and 12 months post-injury as measured by the Glasgow Outcome Scale Extended (GOSE), (2) to explore if demographic/injury-related variables can predict improvement in GOSE score, and (3) to investigate rate of improvement in Disability Rating Scale (DRS) score, in patients with a stable GOSE. All surviving patients ≥16 years of age who were admitted with mo/sTBI (Glasgow Coma Scale [GCS] score ≤13) to the regional trauma center in Central Norway between 2004 and 2019 were prospectively included (n = 439 out of 503 eligible). GOSE and DRS were used to assess outcome. Twelve-months post-injury, 13% with moTBI had severe disability (GOSE 2-4) versus 27% in sTBI, 26% had moderate disability (GOSE 5-6) versus 41% in sTBI and 62% had good recovery (GOSE 7-8) versus 31% in sTBI. From 6 to 12 months post-injury, 27% with moTBI and 32% with sTBI had an improvement, whereas 6% with moTBI and 6% with sTBI had a deterioration in GOSE score. Younger age and higher GCS score were associated with improved GOSE score. Improvement was least frequent for patients with a GOSE score of 3 at 6 months. In patients with a stable GOSE score of 3, an improvement in DRS score was observed in 22 (46%) patients. In conclusion, two thirds and one third of patients with mo/sTBI, respectively, had a good recovery. Importantly, change, mostly improvement, in GOSE score between 6 and 12 months was frequent and argues against the use of 6 months outcome as a time end-point in research. The GOSE does, however, not seem to be sensitive to actual change in function in the lower categories and a combination of outcome measures may be needed to describe the consequences after TBI.

Use of Support Vector Machines Approach via ComBat Harmonized Diffusion Tensor Imaging for the Diagnosis and Prognosis of Mild Traumatic Brain Injury: A CENTER-TBI Study.

The prediction of functional outcome after mild traumatic brain injury (mTBI) is challenging. Conventional magnetic resonance imaging (MRI) does not do a good job of explaining the variance in outcome, as many patients with incomplete recovery will have normal-appearing clinical neuroimaging. More advanced quantitative techniques such as diffusion MRI (dMRI), can detect microstructural changes not otherwise visible, and so may offer a way to improve outcome prediction. In this study, we explore the potential of linear support vector classifiers (linearSVCs) to identify dMRI biomarkers that can predict recovery after mTBI. Simultaneously, the harmonization of fractional anisotropy (FA) and mean diffusivity (MD) via ComBat was evaluated and compared for the classification performances of the linearSVCs. We included dMRI scans of 179 mTBI patients and 85 controls from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI), a multi-center prospective cohort study, up to 21 days post-injury. Patients were dichotomized according to their Extended Glasgow Outcome Scale (GOSE) scores at 6 months into complete (n = 92; GOSE = 8) and incomplete (n = 87; GOSE <8) recovery. FA and MD maps were registered to a common space and harmonized via the ComBat algorithm. LinearSVCs were applied to distinguish: (1) mTBI patients from controls and (2) mTBI patients with complete from those with incomplete recovery. The linearSVCs were trained on (1) age and sex only, (2) non-harmonized, (3) two-category-harmonized ComBat, and (4) three-category-harmonized ComBat FA and MD images combined with age and sex. White matter FA and MD voxels and regions of interest (ROIs) within the John Hopkins University (JHU) atlas were examined. Recursive feature elimination was used to identify the 10% most discriminative voxels or the 10 most discriminative ROIs for each implementation. mTBI patients displayed significantly higher MD and lower FA values than controls for the discriminative voxels and ROIs. For the analysis between mTBI patients and controls, the three-category-harmonized ComBat FA and MD voxel-wise linearSVC provided significantly higher classification scores (81.4% accuracy, 93.3% sensitivity, 80.3% F1-score, and 0.88 area under the curve [AUC], p < 0.05) compared with the classification based on age and sex only and the ROI approaches (accuracies: 59.8% and 64.8%, respectively). Similar to the analysis between mTBI patients and controls, the three-category-harmonized ComBat FA and MD maps voxelwise approach yields statistically significant prediction scores between mTBI patients with complete and those with incomplete recovery (71.8% specificity, 66.2% F1-score and 0.71 AUC, p < 0.05), which provided a modest increase in the classification score (accuracy: 66.4%) compared with the classification based on age and sex only and ROI-wise approaches (accuracy: 61.4% and 64.7%, respectively). This study showed that ComBat harmonized FA and MD may provide additional information for diagnosis and prognosis of mTBI in a multi-modal machine learning approach. These findings demonstrate that dMRI may assist in the early detection of patients at risk of incomplete recovery from mTBI.

Diffusion Tensor and Kurtosis Imaging Findings the First Year following Mild Traumatic Brain Injury.

Despite enormous research interest in diffusion tensor imaging and diffusion kurtosis imaging (DTI; DKI) following mild traumatic brain injury (MTBI), it remains unknown how diffusion in white matter evolves post-injury and relates to acute MTBI characteristics. This prospective cohort study aimed to characterize diffusion changes in white matter the first year after MTBI. Patients with MTBI (n = 193) and matched controls (n = 83) underwent 3T magnetic resonance imaging (MRI) within 72 h and 3- and 12-months post-injury. Diffusion data were analyzed in three steps: 1) voxel-wise comparisons between the MTBI and control group were performed with tract-based spatial statistics at each time-point; 2) clusters of significant voxels identified in step 1 above were evaluated longitudinally with mixed-effect models; 3) the MTBI group was divided into: (A) complicated (with macrostructural findings on MRI) and uncomplicated MTBI; (B) long (1-24 h) and short (< 1 h) post-traumatic amnesia (PTA); and (C) other and no other concurrent injuries to investigate if findings in step 1 were driven mainly by aberrant diffusion in patients with a more severe injury. At 72 h, voxel-wise comparisons revealed significantly lower fractional anisotropy (FA) in one tract and significantly lower mean kurtosis (Kmean) in 11 tracts in the MTBI compared with control group. At 3 months, the MTBI group had significantly higher mean diffusivity in eight tracts compared with controls. At 12 months, FA was significantly lower in four tracts and Kmean in 10 tracts in patients with MTBI compared with controls. There was considerable overlap in affected tracts across time, including the corpus callosum, corona radiata, internal and external capsule, and cerebellar peduncles. Longitudinal analyses revealed that the diffusion metrics remained relatively stable throughout the first year after MTBI. The significant group*time interactions identified were driven by changes in the control rather than the MTBI group. Further, differences identified in step 1 did not result from greater diffusion abnormalities in patients with complicated MTBI, long PTA, or other concurrent injuries, as standardized mean differences in diffusion metrics between the groups were small (0.07 ± 0.11) and non-significant. However, follow-up voxel-wise analyses revealed that other concurrent injuries had effects on diffusion metrics, but predominantly in other metrics and at other time-points than the effects observed in the MTBI versus control group analysis. In conclusion, patients with MTBI differed from controls in white matter integrity already 72 h after injury. Diffusion metrics remained relatively stable throughout the first year after MTBI and were not driven by deviating diffusion in patients with a more severe MTBI.

Preliminary Findings on Cognitive Dysfunction in University-Educated Patients After Mild COVID-19 Disease.

Objective: To investigate cognitive functioning in patients with higher education having post COVID-19 condition. Design: Prospective cohort study. Setting: Outpatient rehabilitation clinic. Participants: Patients (N=38; mean age, 48.5y; 71% women) at the Cognitive Post COVID-19 Clinic at Danderyd University Hospital in Stockholm, Sweden, who sought health care because of self-experienced cognitive problems. All had at least 4 years of university education and an initially mild infection (ie, most were not hospital admitted, none were admitted to intensive care). Interventions: Not applicable. Main Outcome Measures: Cognitive test performance assessed with a comprehensive neuropsychological test battery including Information, Matrix Reasoning, Coding, and Digit Span from Wechsler's Adult Intelligence Scale-IV, Buschke Selective Reminding Test, Rey Complex Figure Test, Ruff 2&7, Color-Word Interference Test, Verbal Fluency, and Trail Making Test. The mean time between the infection and the assessment was 18 months. Results: Cognitive deficits were evident on tests of verbal learning and memory (Buschke Selective Reminding Test) and selective attention (Ruff 2&7). Approximately 50% of the participants had scores lower than 1 SD below the mean in the norm group on the measures of verbal learning and memory. When estimated premorbid cognitive functioning was accounted for, deficits were suggested in most cognitive domains. Conclusions: Post COVID-19 condition seems to be associated with cognitive deficits, even in patients with high education and an initially mild infection.

Trajectories of Persistent Postconcussion Symptoms and Factors Associated With Symptom Reporting After Mild Traumatic Brain Injury.

OBJECTIVE: To examine the trajectories of persistent postconcussion symptoms (PPCS) after mild traumatic brain injury (MTBI) and to investigate which injury-related and personal factors are associated with symptom reporting. DESIGN: Prospective longitudinal cohort study. Follow-up at 3 and 12 months postinjury. SETTING: A level 1 trauma center and an emergency outpatient clinic. PARTICIPANTS: Patients with MTBI (n=358), trauma controls (n=75), and community controls (n=78). MAIN OUTCOME MEASURES: Symptoms were assessed with the British Columbia Postconcussion Symptom Inventory (BC-PSI). Participants were categorized as having moderate to severe PPCS (msPPCS) when reporting ≥3 moderate/severe symptoms or a BC-PSI total score of ≥13. BC-PSI total scores were compared between the groups and were further used to create cutoffs for reliable change by identifying uncommon and very uncommon change in symptoms in the community control group. Associations between symptom reporting and 25 injury-related and personal factors were examined. RESULTS: The MTBI group had a similar prevalence of msPPCS at 3 and 12 months (21%) and reported more symptoms than the control groups. Analyses of individual trajectories, however, revealed considerable change in both msPPCS and BC-PSI total scores in the MTBI group, where both worsening and improvement was common. Intracranial lesions on computed tomography were associated with a greater likelihood of improving from 3 to 12 months. Those with msPPCS at both assessments were more likely to be women and to have these personal preinjury factors: reduced employment, pain, poor sleep, low resilience, high neuroticism and pessimism, and a psychiatric history. CONCLUSIONS: Group analyses suggest a stable prevalence of msPPCS the first year postinjury. However, there was considerable intraindividual change. Several personal factors were associated with maintaining symptoms throughout the first year.

Poor sleep quality is associated with greater negative consequences for cognitive control function and psychological health after mild traumatic brain injury than after orthopedic injury.

OBJECTIVE: To test the hypothesis that poor sleep quality has a stronger negative effect on cognitive control function and psychological health after mild traumatic brain injury (mTBI) than after orthopedic injury. METHOD: Patients with mTBI (n = 197) and trauma controls with orthopedic injuries (n = 82) were included in this prospective longitudinal study. The participants (age 16-60) completed three computerized neurocognitive tests assessing response speed and accuracy at 2 weeks and 3 months after injury, as well as questionnaires and interviews assessing sleep quality and psychological distress at 2 weeks, 3 months, and 12 months after injury. Separate Linear Mixed Models (LMMs) for each of the outcome measures (response speed, response accuracy, psychological distress) were performed. RESULTS: We observed a significant interaction effect between poor sleep quality and group (mTBI vs. trauma controls) in the response speed (p = .028) and psychological distress (p = .001) models, driven by a greater negative impact of poor sleep quality on response speed and psychological distress in the mTBI group. We found no such interaction effect for response accuracy (p = .825), and poor sleep quality was associated with worse accuracy to a similar extent for both groups. CONCLUSIONS: Our findings show that poor sleep quality has a more negative impact on cognitive control function and psychological outcome in patients with mTBI, compared to trauma controls. This indicates an increased vulnerability to poor sleep quality in patients who have suffered an mTBI. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

KD determination from time-resolved experiments on live cells with LigandTracer and reconciliation with end-point flow cytometry measurements.

Design of next-generation therapeutics comes with new challenges and emulates technology and methods to meet them. Characterizing the binding of either natural ligands or therapeutic proteins to cell-surface receptors, for which relevant recombinant versions may not exist, represents one of these challenges. Here we report the characterization of the interaction of five different antibody therapeutics (Trastuzumab, Rituximab, Panitumumab, Pertuzumab, and Cetuximab) with their cognate target receptors using LigandTracer. The method offers the advantage of being performed on live cells, alleviating the need for a recombinant source of the receptor. Furthermore, time-resolved measurements, in addition to allowing the determination of the affinity of the studied drug to its target, give access to the binding kinetics thereby providing a full characterization of the system. In this study, we also compared time-resolved LigandTracer data with end-point KD determination from flow cytometry experiments and hypothesize that discrepancies between these two approaches, when they exist, generally come from flow cytometry titration curves being acquired prior to full equilibration of the system. Our data, however, show that knowledge of the kinetics of the interaction allows to reconcile the data obtained by flow cytometry and LigandTracer and demonstrate the complementarity of these two methods.

Acute Diffusion Tensor and Kurtosis Imaging and Outcome following Mild Traumatic Brain Injury.

In this prospective cohort study, we investigated associations between acute diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) metrics and persistent post-concussion symptoms (PPCS) 3 months after mild traumatic brain injury (mTBI). Adult patients with mTBI (n = 176) and community controls (n = 78) underwent 3 Tesla magnetic resonance imaging (MRI) within 72 h post-injury, estimation of cognitive reserve at 2 weeks, and PPCS assessment at 3 months. Eight DTI and DKI metrics were examined with Tract-Based Spatial Statistics. Analyses were performed in the total sample in uncomplicated mTBI only (i.e., without lesions on clinical MRI), and with cognitive reserve both controlled for and not. Patients with PPCS (n = 35) had lower fractional anisotropy (in 2.7% of all voxels) and kurtosis fractional anisotropy (in 6.9% of all voxels), and higher radial diffusivity (in 0.3% of all voxels), than patients without PPCS (n = 141). In uncomplicated mTBI, only fractional anisotropy was significantly lower in patients with PPCS. Compared with controls, patients with PPCS had widespread deviations in all diffusion metrics. When including cognitive reserve as a covariate, no significant differences in diffusion metrics between patients with and without PPCS were present, but patients with PPCS still had significantly higher mean, radial, and axial diffusivity than controls. In conclusion, patients who developed PPCS had poorer white matter microstructural integrity acutely after the injury, compared with patients who recovered and healthy controls. Differences became less pronounced when cognitive reserve was controlled for, suggesting that pre-existing individual differences in axonal integrity accounted for some of the observed differences.

Examining the Subacute Effects of Mild Traumatic Brain Injury Using a Traditional and Computerized Neuropsychological Test Battery.

This study investigates subacute cognitive effects of mild traumatic brain injury (MTBI) in the Trondheim Mild TBI Study, as measured, in part, by the neuropsychological test battery of the Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) program, including computerized tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) and traditional paper-and-pencil tests. We investigated whether cognitive function was associated with injury severity: intracranial traumatic lesions on neuroimaging, witnessed loss of consciousness (LOC), or post-traumatic amnesia (PTA) >1 h. Further, we explored which of the tests in the CENTER-TBI battery might be associated with the largest subacute effects of MTBI (i.e., at 2 weeks post-injury). We recruited 177 patients with MTBI (16-59 years of age) from a regional trauma center and an outpatient clinic,79 trauma control participants, and 81 community control participants. The MTBI group differed from community controls only on one traditional test of processing speed (coding; p = 0.009, Cliff's delta [Δ] = 0.20). Patients with intracranial abnormalities performed worse than those without on a traditional test (phonemic verbal fluency; p = 0.043, Δ = 0.27), and patients with LOC performed differently on the Attention Switching Task from the CANTAB (p = 0.020, Δ = -0.20). Patients with PTA >1 h performed worse than those with <1 h on 10 measures, from traditional tests and the CANTAB (Δ = 0.33-0.20), likely attributable, at least in part, to pre-existing differences in intellectual functioning between groups. In general, those with MTBI had good neuropsychological outcome 2 weeks after injury and no particular CENTER-TBI computerized or traditional tests seemed to be more sensitive to subtle cognitive deficits.

Personal Factors Associated With Postconcussion Symptoms 3 Months After Mild Traumatic Brain Injury.

OBJECTIVE: To describe personal factors in patients with mild traumatic brain injury (MTBI) and 2 control groups and to explore how such factors were associated with postconcussion symptoms (PCSs). DESIGN: Prospective cohort study. SETTING: Level 1 trauma center and outpatient clinic. PARTICIPANTS: Participants (N=541) included patients with MTBI (n=378), trauma controls (n=82), and community controls (n=81). MAIN OUTCOME MEASURES: Data on preinjury health and work status, personality, resilience, attention deficit/hyperactivity, and substance use. Computed tomography (CT) findings and posttraumatic amnesia were recorded. Symptoms were assessed at 3 months with the British Columbia Postconcussion Symptom Inventory and labeled as PCS+ if ≥3 symptoms were reported or the total score was ≥13. Predictive models were fitted with penalized logistic regression using the least absolute shrinkage and selection operator (lasso) in the MTBI group, and model fit was assessed with optimism-corrected area under the curve (AUC) of the receiver operating characteristic curve. RESULTS: There were few differences in personal factors between the MTBI group and the 2 control groups without MTBI. Rates of PCS+ were 20.8% for the MTBI group, 8.0% for trauma controls, and 1.3% for community controls. In the MTBI group, there were differences between the PCS+ and PCS- group on most personal factors and injury-related variables in univariable comparisons. In the lasso models, the optimism-corrected AUC for the full model was 0.79, 0.73 for the model only including personal factors, and 0.63 for the model only including injury variables. Working less than full time before injury, having preinjury pain and poor sleep quality, and being female were among the selected predictors, but also resilience and some personality traits contributed in the model. Intracranial abnormalities on CT were also a risk factor for PCS. CONCLUSIONS: Personal factors convey important prognostic information in patients with MTBI. A vulnerable work status and preinjury health problems might indicate a need for follow-up and targeted interventions.

Examining Test-Retest Reliability and Reliable Change for Cognition Endpoints for the CENTER-TBI Neuropsychological Test Battery.

Objective: Seven candidate cognition composite scores have been developed and evaluated as part of a research program designed to validate a cognition endpoint for traumatic brain injury (TBI) research and clinical trials, but these composites have yet to be examined longitudinally. This study examined test-retest reliability and methods for determining reliable change for these seven candidate composite scores, using the neuropsychological test battery from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI). Methods: Participants (18-59 years-old) with mild TBI (n = 124), orthopedic trauma without head injury (n = 67), and healthy community controls (n = 63) from the Trondheim MTBI follow-up study completed the CENTER-TBI neuropsychological test battery at 2 weeks and 3 months after injury. The battery included both traditional paper-and-pencil tests and computerized tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Seven composite scores were calculated for the paper-and-pencil tests, the CANTAB tests, and all tests combined (i.e., 21 composites in total on each assessment): the overall test battery mean (OTBM); global deficit score (GDS); neuropsychological deficit score-weighted (NDS-W); low score composite (LSC); and the number of scores ≤5th percentile, ≤16th percentile, or <50th percentile. The OTBM was calculated by averaging T scores for all tests. The other composite scores were deficit-based scores, assigning different weights to low scores. Results: All composites revealed better cognitive performance at the 3-month assessment compared to the 2-week assessment and the magnitude of improvement was similar across groups. Differences, in terms of effect sizes, were largest on the OTBMs. In the combined composites, the test-retest correlation was highest for the OTBM (Spearman's rho = 0.87, in the community control group) and lowest for the number of scores ≤5th percentile (rho = 0.41). Conclusion: The high test-retest reliability of the OTBM appears to favor its use in TBI research; however, future studies are needed to examine these candidate composite scores in participants with more severe TBIs and cognitive deficits and the association of the composites with functional outcomes.

Developing Cognition Endpoints for the CENTER-TBI Neuropsychological Test Battery.

Background: Measuring cognitive functioning is common in traumatic brain injury (TBI) research, but no universally accepted method for combining several neuropsychological test scores into composite, or summary, scores exists. This study examined several possible composite scores for the test battery used in the large-scale study Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI). Methods: Participants with mild traumatic brain injury (MTBI; n = 140), orthopedic trauma (n = 72), and healthy community controls (n = 70) from the Trondheim MTBI follow-up study completed the CENTER-TBI test battery at 2 weeks after injury, which includes both traditional paper-and-pencil tests and tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Seven composite scores were calculated for the paper and pencil tests, the CANTAB tests, and all tests combined (i.e., 21 composites): the overall test battery mean (OTBM); global deficit score (GDS); neuropsychological deficit score-weighted (NDS-W); low score composite (LSC); and the number of scores ≤5th percentile, ≤16th percentile, or <50th percentile. Results: The OTBM and the number of scores <50th percentile composites had distributional characteristics approaching a normal distribution. The other composites were in general highly skewed and zero-inflated. When the MTBI group, the trauma control group, and the community control group were compared, effect sizes were negligible to small for all composites. Subgroups with vs. without loss of consciousness at the time of injury did not differ on the composite scores and neither did subgroups with complicated vs. uncomplicated MTBIs. Intercorrelations were high within the paper-and-pencil composites, the CANTAB composites, and the combined composites and lower between the paper-and-pencil composites and the CANTAB composites. Conclusion: None of the composites revealed significant differences between participants with MTBI and the two control groups. Some of the composite scores were highly correlated and may be redundant. Additional research on patients with moderate to severe TBIs is needed to determine which scores are most appropriate for TBI clinical trials.

Change in self-reported cognitive symptoms after mild traumatic brain injury is associated with changes in emotional and somatic symptoms and not changes in cognitive performance.

OBJECTIVE: To investigate (a) whether self-reported cognitive symptoms after mild traumatic brain injury (MTBI) are associated with cognitive test performances, and (b) whether improvement in self-reported symptoms from 2 weeks to 3 months after MTBI is associated with improvement in cognitive test performances. METHOD: Patients with MTBI (n = 135), aged 16-59, who initially presented to the emergency department, completed the Rivermead Post Concussion Symptoms Questionnaire (RPQ), the Brief Symptom Inventory 18, and cognitive tests (i.e., Controlled Oral Word Association, Coding, Rey Auditory Verbal Learning, and Trail Making test) at 2 weeks and 3 months after MTBI. Using Spearman's rank correlations (ρ), associations were examined between self-report measures and cognitive test performances at each time point and between change scores (i.e., 3-month score minus 2-week score) on each outcome. RESULTS: At 3 months, 27% reported cognitive symptoms to some extent. At both assessments, greater severity of RPQ cognitive symptoms was very weakly associated with worse cognitive test performances (2-week ρ range = -0.19 to -0.01; 3-month ρ range = -0.20 to -0.10). RPQ cognitive symptoms were, however, strongly related to greater somatic and emotional symptoms. Change in self-reported cognitive symptoms from 2 weeks to 3 months was not associated with change in cognitive test performance. In contrast, change in self-reported cognitive symptoms was strongly associated with change in emotional (ρ = 0.58) and somatic symptoms (ρ = 0.57). CONCLUSIONS: These findings indicate that improvements in subjective cognitive symptoms after MTBI co-occur with improvements on other subjective metrics, but are not related to improvements in objectively measured cognitive functioning. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

A combinatorial study of experimental analysis and mathematical modeling: How do chitosan nanoparticles deliver therapeutics into cells?

Chitosan nanosystems have been widely explored to deliver therapeutic into cells. The cationic nature of the polymer facilitates its entry into the cell via the negatively charged lipid bilayer. Though the interaction is feasible for successful payload delivery, very little is known about the mechanistic aspects and kinetics of interaction of chitosan nanoparticles (Chnps) with the cellular bilayer membrane. Moreover, the precise mechanism of delivery of therapeutic agents by the Chnps is unknown. The polymerbilayer membrane is anticipated to play a crucial role in deciding its ultimate intracellular fate, while delivering its therapeutic payload. Here, we have made an attempt to understand the interaction of Chnps with the cellular membrane for delivering payload, through experimental analysis and predictive mathematical modeling. We observed that the positively charged, mucoadhesive Chnps lack specificity towards a particular cell type, but are rather successful in the intracellular delivery of nucleic acids.

Cognitive Reserve Moderates Cognitive Outcome After Mild Traumatic Brain Injury.

OBJECTIVE: To investigate whether cognitive reserve moderates differences in cognitive functioning between patients with mild traumatic brain injury (MTBI) and controls without MTBI and to examine whether patients with postconcussion syndrome have lower cognitive functioning than patients without postconcussion syndrome at 2 weeks and 3 months after injury. DESIGN: Trondheim MTBI follow-up study is a longitudinal controlled cohort study with cognitive assessments 2 weeks and 3 months after injury. SETTING: Recruitment at a level 1 trauma center and at a general practitioner-run, outpatient clinic. PARTICIPANTS: Patients with MTBI (n=160) according to the World Health Organization criteria, trauma controls (n=71), and community controls (n=79) (N=310). MAIN OUTCOME MEASURES: A cognitive composite score was used as outcome measure. The Vocabulary subtest was used as a proxy of cognitive reserve. Postconcussion syndrome diagnosis was assessed at 3 months with the British Columbia Postconcussion Symptom Inventory. RESULTS: Linear mixed models demonstrated that the effect of vocabulary scores on the cognitive composite scores was larger in patients with MTBI than in community controls at 2 weeks and at 3 months after injury (P=.001). Thus, group differences in the cognitive composite score varied as a function of vocabulary scores, with the biggest differences seen among participants with lower vocabulary scores. There were no significant differences in the cognitive composite score between patients with (n=29) and without (n=131) postconcussion syndrome at 2 weeks or 3 months after injury. CONCLUSION: Cognitive reserve, but not postconcussion syndrome, was associated with cognitive outcome after MTBI. This supports the cognitive reserve hypothesis in the MTBI context and suggests that persons with low cognitive reserve are more vulnerable to reduced cognitive functioning if they sustain an MTBI.

Protective nature of low molecular weight chitosan in a chitosan-Amphotericin B nanocomplex - A physicochemical study.

Chitosan, a biopolymer of immense potential, has been well-explored over the past decade in the biomedical field. Despite its numerous biological properties like anti-microbial, anti-inflammatory, anti-diabetic etc., limited studies have been conducted on its ability to protect therapeutic molecules in nano-formulations. Amphotericin B (AMP) is one such therapeutic molecule which requires protection as it possesses inherent limitations of poor water-solubility, susceptibility to oxidation- and/or light-induced degradation etc. Although AMP formulations have been quite successful in treating chronic fungal infections, their high cost, prolonged nature of therapy and instability over longer durations has necessitated the development of alternative carriers. In the present study, a stable nanoparticulate formulation was successfully prepared using low molecular weight chitosan and the anti-fungal agent AMP and this was found to offer protection to the labile AMP. The developed nanocomplexes could prevent degradation of AMP up to six months, in solution form, unlike the native drug which degraded in <24 h. Antifungal studies of the developed nanocomplexes revealed a surface charge-dependent antifungal activity. Furthermore, the nanocomplexes did not affect the viability of mammalian cells and showed excellent intracellular uptake and retention, and hence suggested potential of the nanocomplexes in alleviating systemic fungal infections.

The value of incorporating personally relevant stimuli into consciousness assessment with the Coma Recovery Scale - Revised: A pilot study.

OBJECTIVE: To explore whether the use of personally relevant stimuli, for some tasks in the Coma Recovery Scale - Revised (CRS-R), generates more responses in patients with prolonged disorders of consciousness compared with neutral stimuli. DESIGN: Multiple single-case design. SUBJECTS: Three patients with prolonged disorders of consciousness recruited from an inpatient department at a regional brain injury rehabilitation clinic in Stockholm, Sweden. METHODS: Patients were repeatedly assessed with the CRS-R. Randomization tests (bootstrapping) were used to compare the number of responses generated by personally relevant and neutral stimuli on 5 items in the CRS-R. RESULTS: Compared with neutral stimuli, photographs of relatives generated significantly more visual fixations. A mirror generated visual pursuit to a significantly greater extent than other self-relevant stimuli. On other items, no significant differences between neutral and personally relevant stimuli were seen. CONCLUSION: Personally relevant visual stimuli may minimize the risk of missing visual fixation, compared with the neutral stimuli used in the current gold standard behavioural assessment measure (CRS-R). However, due to the single-subject design this conclusion is tentative and more research is needed.

A real-time in vitro assay as a potential predictor of in vivo tumor imaging properties.

INTRODUCTION: Selective tumor targeting strategies based on cell surface molecules enable new personalized diagnosis and treatments, potentially lowering adverse effects and increasing efficacy. Radio-immunotargeting generally relies on a molecule binding to a cancer-specific target. It is therefore important to understand the properties of molecular interactions in their working environment and how to translate these properties measured in vitro into the in vivo molecular imaging situation. METHODS: Time resolved interaction analysis in vitro was compared with a corresponding in vivo xenograft mouse model. The antibody fragment AbD15179 was labeled with (125)I or (111)In, and analyzed on cell lines with differing CD44v6 expression in vitro, and in a dual tumor xenograft model derived from the same cell lines. In vitro LigandTracer measurements were analyzed with TraceDrawer and Interaction Map. Conjugate sensitivity, kinetics, and signal-to-background ratios were assessed for both tumor cells in vitro and xenograft tumors in vivo. RESULTS: In vitro results revealed a general biphasic appearance of a high- and a low-affinity interaction event. The (111)In-labeled fragment displayed the largest proportion of the high-affinity interaction with increased sensitivity and retention compared to (125)I-Fab. In vivo results were in agreement with in vitro data, with increased retention, higher sensitivity and better contrast for the (111)In-labeled fragment compared to (125)I. CONCLUSIONS: Time resolved binding characteristics measured in vitro largely matched the in vivo performance for the conjugates, which is promising for future studies. In vitro time-resolved LigandTracer assays are efficient, rapid, and in this study shown to be able to predict in vivo outcomes. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: Further studies are needed to confirm these findings, but the method is promising considering the ethical need to reduce the use of laboratory animals, as well as reducing costs for the development of tumor targeting compounds in the future.

Conjugation effects on antibody-drug conjugates: evaluation of interaction kinetics in real time on living cells.

Antibody-drug conjugates (ADC) have shown promising effects in cancer therapy by combining the target specificity of an antibody with the toxicity of a chemotherapeutic drug. As the number of therapeutic antibodies is significantly larger than those used as ADCs, there is unused potential for more effective therapies. However, the conjugation of an additional molecule to an antibody may affect the interaction with its target, altering association rate, dissociation rate, or both. Any changes of the binding kinetics can have subsequent effects on the efficacy of the ADCs, thus the kinetics are important to monitor during ADC development and production. This paper describes a method for the analysis of conjugation effects on antibody binding to its antigen, using the instrument LigandTracer and a fluorescent monovalent anti-IgG binder denoted FIBA, which did not affect the interaction. All measurements were done in real time using living cells which naturally expressed the antigens. With this method the binding profiles of different conjugations of the therapeutic anti-EGFR antibody cetuximab and the anti-CD44v6 antibody fragment AbD15171 were evaluated and compared. Even comparatively small modifications of cetuximab altered the interaction with the epidermal growth factor receptor (EGFR). In contrast, no impact on the AbD15171-CD44v6 interaction was observed upon conjugation. This illustrates the importance to study the binding profile for each ADC combination, as it is difficult to draw any general conclusion about conjugation effects. The modification of interaction kinetics through conjugation opens up new possibilities when optimizing an antibody or an ADC, since the conjugations can be used to create a binding profile more apt for a specific clinical need.