Zinc Concentration Dynamics Indicate Neurological Impairment Odds after Traumatic Spinal Cord Injury

Traumatic Spinal Cord Injury (TSCI) is debilitating and often results in a loss of motor and sensory function caused by an interwoven set of pathological processes. Oxidative stress and inflammatory processes are amongst the critical factors in the secondary injury phase after TSCI. The essential trace element Zinc (Zn) plays a crucial role during this phase as part of the antioxidant defense system. The study aims to determine dynamic patterns in serum Zn concentration in patients with TSCI and test for a correlation with neurological impairment. A total of 42 patients with TSCI were enrolled in this clinical observational study. Serum samples were collected at five different points in time after injury (at admission, and after 4 h, 9 h, 12 h, 24 h, and 3 d). The analysis of the serum Zn concentrations was conducted by total reflection X-ray fluorescence (TXRF). The patients were divided into two groups-a study group S (n = 33) with neurological impairment, including patients with remission (G1, n = 18) and no remission (G0, n = 15) according to a positive AIS (American Spinal Injury Association (ASIA) Impairment Scale) conversion within 3 months after the trauma; and a control group C (n = 9), consisting of subjects with vertebral fractures without neurological impairment. The patient data and serum concentrations were examined and compared by non-parametric test methods to the neurological outcome. The median Zn concentrations in group S dropped within the first 9 h after injury (964 µg/L at admission versus 570 µg/L at 9 h, p < 0.001). This decline was stronger than in control subjects (median of 751 µg/L versus 729 µg/L, p = 0.023). A binary logistic regression analysis including the difference in serum Zn concentration from admission to 9 h after injury yielded an area under the curve (AUC) of 82.2% (CI: 64.0-100.0%) with respect to persistent neurological impairment. Early Zn concentration dynamics differed in relation to the outcome and may constitute a helpful diagnostic indicator for patients with spinal cord trauma. The fast changes in serum Zn concentrations allow an assessment of neurological impairment risk on the first day after trauma. This finding supports strategies for improving patient care by avoiding strong deficits via adjuvant nutritive measures, e.g., in unresponsive patients after trauma

Quality Criteria for the Analysis of Microplastic in Biota Samples : A Critical Review

Data on ingestion of microplastics by marine biota are quintessential for monitoring and risk assessment of microplastics in the environment. Current studies, however, portray a wide spread in results on the occurrence of microplastic ingestion, highlighting a lack of comparability of results, which might be attributed to a lack of standardization of methods. We critically review and evaluate recent microplastic ingestion studies in aquatic biota, propose a quality assessment method for such studies, and apply the assessment method to the reviewed studies. The quality assessment method uses ten criteria: sampling method and strategy, sample size, sample processing and storage, laboratory preparation, clean air conditions, negative controls, positive controls, target component, sample (pre)treatment, and polymer identification. The results of this quality assessment show a dire need for stricter quality assurance in microplastic ingestion studies. On average, studies score 8.0 out of 20 points for “completeness of information” and 0 for “reliability”. Alongside the assessment method, a standardized protocol for detecting microplastic in biota samples incorporating these criteria is provided

Quantifying ecological risks of aquatic micro- and nanoplastic

Diverse effects of nano- and microplastic (NMP) have been demonstrated in the laboratory. We provide a broad review of current knowledge on occurrence, measurement, modeling approaches, fate, exposure, effects, and effect thresholds as regard to microplastics in the aquatic environment. Using thisinformation, we perform a ‘proof of concept’ risk assessment for NMP, accounting for the diversity of the material. New data is included showing how bioturbation affects exposure, and exposure is evaluated based on literature data and model analyses. We review exposure and effect data and provide aworst case risk characterization, by comparing HC5 effect thresholds from ‘all inclusive’ Species Sensitivity Distributions (SSDs) with the highest environmental concentrations reported. HC5 values show wide confidence intervals yet suggest that sensitive aquatic organisms in near-shore surface waters might be at risk

Modeling the fate and transport of plastic debris in freshwaters : Review and Guidance

Contamination with plastic debris has been recognized as one of today’s major environmental quality problems. Because most of the sources are land based, concerns are increasingly focused on the freshwater and terrestrial environment. Fate and transport models for plastic debris can complement information from measurements and will play an important role in the prospective risk assessment of plastic debris. We review the present knowledge with respect to fate and transport modeling of plastic debris in freshwater catchment areas, focusing especially on nano- and microplastics. Starting with a brief overview of theory and models for nonplastic particles, we discuss plastic-specific properties, processes, and existing mass-balance-, multimedia-, and spatiotemporally explicit fate models. We find that generally many theoretical and conceptual approaches from models developed earlier for other types of (low density) particles apply also to plastic debris. A unique feature of plastic debris, however, is its combination of high persistence, low density, and extremely wide size distribution, ranging from the nanometer to the >cm scale. This causes the system behavior of plastic debris to show a far wider variety than most other materials or chemicals. We provide recommendations for further development of these models and implications and guidance for how fate and transport models can be used in a framework for the tiered risk assessment of plastic debris

Nanoplastic Affects Growth of <i>S. obliquus</i> and Reproduction of <i>D. magna</i>

The amount of nano- and microplastic in the aquatic environment rises due to the industrial production of plastic and the degradation of plastic into smaller particles. Concerns have been raised about their incorporation into food webs. Little is known about the fate and effects of nanoplastic, especially for the freshwater environment. In this study, effects of nano-polystyrene (nano-PS) on the growth and photosynthesis of the green alga <i>Scenedesmus obliquus</i> and the growth, mortality, neonate production, and malformations of the zooplankter <i>Daphnia magna</i> were assessed. Nano-PS reduced population growth and reduced chlorophyll concentrations in the algae. Exposed <i>Daphnia</i> showed a reduced body size and severe alterations in reproduction. Numbers and body size of neonates were lower, while the number of neonate malformations among neonates rose to 68% of the individuals. These effects of nano-PS were observed between 0.22 and 103 mg nano-PS/L. Malformations occurred from 30 mg of nano-PS/L onward. Such plastic concentrations are much higher than presently reported for marine waters as well as freshwater, but may eventually occur in sediment pore waters. As far as we know, these results are the first to show that direct life history shifts in algae and <i>Daphnia</i> populations may occur as a result of exposure to nanoplastic

Correction to Plastic As a Carrier of POPs to Aquatic Organisms: A Model Analysis

Correction to Plastic As a Carrier of POPs to Aquatic Organisms: A Model Analysi

Plastic as a Carrier of POPs to Aquatic Organisms: A Model Analysis

It has been hypothesized that persistent organic pollutants (POPs) in microplastic may pose a risk to aquatic organisms. Here we develop and analyze a conceptual model that simulates the effects of plastic on bioaccumulation of POPs. The model accounts for dilution of exposure concentration by sorption of POPs to plastic (POP “dilution”), increased bioaccumulation by ingestion of plastic-containing POPs (“carrier”), and decreased bioaccumulation by ingestion of clean plastic (“cleaning”). The model is parametrized for the lugworm <i>Arenicola marina</i> and evaluated against recently published bioaccumulation data for this species from laboratory bioassays with polystyrene microplastic. Further scenarios include polyethylene microplastic, nanosized plastic, and open marine systems. Model analysis shows that plastic with low affinity for POPs such as polystyrene will have a marginal decreasing effect on bioaccumulation, governed by dilution. For stronger sorbents such as polyethylene, the dilution, carrier, and cleaning mechanism are more substantial. In closed laboratory bioassay systems, dilution and cleaning dominate, leading to decreased bioaccumulation. Also in open marine systems a decrease is predicted due to a cleaning mechanism that counteracts biomagnification. However, the differences are considered too small to be relevant from a risk assessment perspective

Accelerated cognitive ageing in epilepsy : a neuropsychological evaluation of cognitive deterioration

Objective: Shed light on cognitive deterioration in Accelerated Cognitive Ageing (ACA) in epilepsy from a neuropsychological point of view in order to improve clinical diagnostics. Methods: We compared the IQ-profile including GAI, OPIE IV-premorbid IQ and deterioration-scores of 21 epilepsy patients with ACA with 21 matched epilepsy patients without ACA (Epilepsy Controls) and 16 age- and education-matched Healthy Controls. Memory was also evaluated. Results: Premorbid IQs were equal in all groups. Deterioration was apparent in the ACA-group in the WAIS-IV FSIQ and PRI, whereas no deterioration was found in the two control groups. PSI was impaired in both epilepsy groups, though with more impairment seen in the ACA-group. The VCI remained unimpaired. The FSIQ-GAI discrepancy was equal in both patient groups and significantly larger than in the Healthy Controls. WMS-IV memory indices were of average level in all groups. Memory impairment in ACA was not statistically different from the Epilepsy Controls. 85.7% of ACA-patients could be correctly classified through factors DET_FSIQ and PSI. Conclusions: Cognitive deterioration in ACA is characterized by an average drop of 19 IQ-points in FSIQ and PRI. Verbal abilities remain unimpaired. Impairments in fluid functions compromise cognitive abilities in epilepsy, but only partially contribute to cognitive deterioration in ACA. PSI proved to have some diagnostic value in differentiating epilepsy patients from healthy controls, but fails to differentiate between ACA and Epilepsy Controls. A comparison made between OPIE-IV equations and obtained IQs leads to a significant better detection of cognitive deterioration in epilepsy than the use of GAI-FSIQ discrepancies alone

Neu\u3csup\u3e3\u3c/sup\u3eCA-RT:a framework for real-time fMRI analysis

\u3cp\u3eReal-time functional magnetic resonance imaging (rtfMRI) allows visualisation of ongoing brain activity of the subject in the scanner. Denoising algorithms aim to rid acquired data of confounding effects, enhancing the blood oxygenation level-dependent (BOLD) signal. Further image processing and analysis methods, like general linear models (GLM) or multivariate analysis, then present application-specific information to the researcher. These processes are typically applied to regions of interest but, increasingly, rtfMRI techniques extract and classify whole brain functional networks and dynamics as correlates for brain states or behaviour, particularly in neuropsychiatric and neurocognitive disorders. We present Neu\u3csup\u3e3\u3c/sup\u3eCA-RT: a Matlab-based rtfMRI analysis framework aiming to advance scientific knowledge on real-time cognitive brain activity and to promote its translation into clinical practice. Design considerations are listed based on reviewing existing rtfMRI approaches. The toolbox integrates established SPM preprocessing routines, real-time GLM mapping of fMRI data to a basis set of spatial brain networks, correlation of activity with 50 behavioural profiles from the BrainMap database, and an intuitive user interface. The toolbox is demonstrated in a task-based experiment where a subject executes visual, auditory and motor tasks inside a scanner. In three out of four experiments, resulting behavioural profiles agreed with the expected brain state.\u3c/p\u3

Indirect frontocingulate structural connectivity predicts clinical response to accelerated rTMS in major depressive disorder

Background: Repetitive transcranial magnetic stimulation (rTMS) is an established treatment for major depressive disorder (MDD), but its clinical efficacy remains rather modest. One reason for this could be that the propagation of rTMS effects via structural connections from the stimulated area to deeper brain structures (such as the cingulate cortices) is suboptimal. Methods: We investigated whether structural connectivity - derived from diffusion MRI data - could serve as a biomarker to predict treatment response. We hypothesized that stronger structural connections between the patient-specific stimulation position in the left dorsolateral prefrontal cortex (dlPFC) and the cingulate cortices would predict better clinical outcomes. We applied accelerated intermittent theta burst stimulation (aiTBS) to the left dlPFC in 40 patients with MDD. We correlated baseline structural connectivity, quantified using various metrics (fractional anisotropy, mean diffusivity, tract density, tract volume and number of tracts), with changes in depression severity scores after aiTBS. Results: Exploratory results (p < 0.05) showed that structural connectivity between the patient-specific stimulation site and the caudal and posterior parts of the cingulate cortex had predictive potential for clinical response to aiTBS. Limitations: We used the diffusion tensor to perform tractography. A main limitation was that multiple fibre directions within voxels could not be resolved, which might have led to missing connections in some patients. Conclusion: Stronger structural frontocingular connections may be of essence to optimally benefit from left dlPFC rTMS treatment in MDD. Even though the results are promising, further investigation with larger numbers of patients, more advanced tractography algorithms and classic daily rTMS treatment paradigms is warranted