Intra-arterial injection of neural stem cells using a microneedle technique does not cause microembolic strokes

Intra-arterial (IA) injection represents an experimental avenue for minimally invasive delivery of stem cells to the injured brain. It has however been reported that IA injection of stem cells carries the risk of reduction in cerebral blood flow (CBF) and microstrokes. Here we evaluate the safety of IA neural progenitor cell (NPC) delivery to the brain. Cerebral blood flow of rats was monitored during IA injection of single cell suspensions of NPCs after stroke. Animals received 1 × 10(6) NPCs either injected via a microneedle (microneedle group) into the patent common carotid artery (CCA) or via a catheter into the proximally ligated CCA (catheter group). Controls included saline-only injections and cell injections into non-stroked sham animals. Cerebral blood flow in the microneedle group remained at baseline, whereas in the catheter group a persistent (15 minutes) decrease to 78% of baseline occurred (P<0.001). In non-stroked controls, NPCs injected via the catheter method resulted in higher levels of Iba-1-positive inflammatory cells (P=0.003), higher numbers of degenerating neurons as seen in Fluoro-Jade C staining (P<0.0001) and ischemic changes on diffusion weighted imaging. With an appropriate technique, reduction in CBF and microstrokes do not occur with IA transplantation of NPCs.

Brain CYP1A in seabream, Sparus aurata exposed to benzo(a)pyrene

This study compares basal and induced expression of cytochrome P4501A-CYP1A in the brain of gilthead seabream, Sparus aurata. Larval or adult seabream were exposed to benzo(a)pyrene -B(a)P- and the CYP1A response was assessed by analyzing CYP1A mRNA (RT-PCR), CYP1A protein (expression levels: ELISA, western blotting; cellular localization: immunohistochemistry), and CYP1A catalytic activity (7-ethoxyresorufin-O-deethylase-EROD). In the brain of adult S. aurata, CYP1A immunostaining was generally detected in the vasculature. It was present in the neuronal fibers and glial cells of the olfactory bulbs and the ventral telencephalon. ELISA and RT-PCR analyses confirmed CYP1A expression in the brains of non-exposed seabream. B(a)P exposure led to increased CYP1A staining mainly in neuronal fibers and glial cells of the olfactory bulbs, but also in the vascular endothelia. EROD activity, however, could not be detected in the brain of adult seabream, neither in control nor in exposed fish. In the developing brain of S. aurata larvae, immunohistochemical staining detected CYP1A protein exclusively in endothelia of the olfactory placode and in retina. Staining intensity of CYP1A slightly increases with larval development, especially in vascular brain endothelia. Exposing the larvae to 0.3 or 0.5 microg B(a)P/L from hatching until 15 days post hatching (dph) did not result in enhanced CYP1A immunostaining in the brain. In samples of whole seabream larvae, both from controls and BaP treatments, neither CYP1A mRNA, protein nor catalytic activity were detectable. The results demonstrate that CYP1A is expressed already and inducible in the larval brain, but that the regional and cellular expression differs partly between larval and adult brain. This may have implications for the toxicity of CYP1A-inducing xenobiotics on early and mature life stages of seabream.

Predictors of depressed mood 12 months after injury. Contribution of self-efficacy and social support

Abstract Purpose: There is evidence that depressed mood and perception of pain are related in patients with chronic illness. However, how individual resources such as self-efficacy and social support play a role in this association remains unclear. The aim of this study was to investigate the influence of both variables as either moderator or mediator. Method: In a longitudinal study, 274 injured workers (M = 43.24 years) were investigated. Data were collected on sociodemographics, depressed mood, pain, social support, and self-efficacy at three months post-injury, and depressed mood one year post-injury. Results: Hierarchical multiple linear regression analyses revealed that pain (β = 0.14; p < 0.01) and social support (β = -0.18; p < 0.001) were significant predictors of depressed mood. Self-efficacy moderated the relationship of pain (β = -0.12; p < 0.05) and depressed mood after one year. Lower self-efficacy in combination with pain had a stronger impact than higher self-efficacy and pain on depressed mood. Social support did not moderate the association. Conclusions: Self-efficacy for managing pain is important in the development of depressed mood. According to the results of this study, we suggest that the detection of low social support and low self-efficacy might be important in long-term rehabilitation process. Implications for Rehabilitation Risk for depressed mood one year after an accident is high: One in five workers report depressed mood. Protective factors for depressed mood in injured workers needs to be considered in the rehabilitation. Focusing on resources like social support and self-efficacy could be protective against depressed mood. The early detection of low social support and low self-efficacy might be important in long-term rehabilitation processes

A new sensitive method for the quantification of glyoxal and methylglyoxal in snow and ice by stir bar sorptive extraction and liquid desorption-HPLC-ESI-MS

In this study, the development of a new sensitive method for the analysis of alpha-dicarbonyls glyoxal (G) and methylglyoxal (MG) in environmental ice and snow is presented. Stir bar sorptive extraction with in situ derivatization and liquid desorption (SBSE-LD) was used for sample extraction, enrichment, and derivatization. Measurements were carried out using high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). As part of the method development, SBSE-LD parameters such as extraction time, derivatization reagent, desorption time and solvent, and the effect of NaCl addition on the SBSE efficiency as well as measurement parameters of HPLC-ESI-MS/MS were evaluated. Calibration was performed in the range of 1–60 ng/mL using spiked ultrapure water samples, thus incorporating the complete SBSE and derivatization process. 4-Fluorobenzaldehyde was applied as internal standard. Inter-batch precision was <12 % RSD. Recoveries were determined by means of spiked snow samples and were 78.9 ± 5.6 % for G and 82.7 ± 7.5 % for MG, respectively. Instrumental detection limits of 0.242 and 0.213 ng/mL for G and MG were achieved using the multiple reaction monitoring mode. Relative detection limits referred to a sample volume of 15 mL were 0.016 ng/mL for G and 0.014 ng/mL for MG. The optimized method was applied for the analysis of snow samples from Mount Hohenpeissenberg (close to the Meteorological Observatory Hohenpeissenberg, Germany) and samples from an ice core from Upper Grenzgletscher (Monte Rosa massif, Switzerland). Resulting concentrations were 0.085–16.3 ng/mL for G and 0.126–3.6 ng/mL for MG. Concentrations of G and MG in snow were 1–2 orders of magnitude higher than in ice core samples. The described method represents a simple, green, and sensitive analytical approach to measure G and MG in aqueous environmental samples.

Use of contrast-enhanced fluid-attenuated inversion recovery sequence to detect brain lesions in dogs and cats.

BACKGROUND The diagnostic value of a contrast-enhanced T2-weighted FLAIR sequence (ceFLAIR) in brain imaging is unclear. HYPOTHESIS/OBJECTIVES That the number of brain lesions detected with ceFLAIR would be no greater than the sum of lesions detected with nFLAIR and ceT1W sequence. ANIMALS One hundred and twenty-nine animals (108 dogs and 21 cats) undergoing magnetic resonance imaging (MRI) of the head between July 2010 and October 2011 were included in the study. METHODS A transverse ceFLAIR was added to a standard brain MRI protocol. Presence and number of lesions were determined based on all available MRI sequences by 3 examiners in consensus and lesion visibility was evaluated for nFLAIR, ceFLAIR, and ceT1W sequences. RESULTS Eighty-three lesions (58 intra-axial and 25 extra-axial) were identified in 51 patients. Five lesions were detected with nFLAIR alone, 2 with ceT1W alone, and 1 with ceFLAIR alone. Significantly higher numbers of lesions were detected using ceFLAIR than nFLAIR (76 versus 67 lesions; P = 0.04), in particular for lesions also detected with ceT1W images (53 versus 40; P =.01). There was no significant difference between the number of lesions detected with combined nFLAIR and ceT1W sequences compared to those detected with ceFLAIR (82 versus 76; P =.25). CONCLUSION AND CLINICAL IMPORTANCE Use of ceFLAIR as a complementary sequence to nFLAIR and ceT1W sequences did not improve the detection of brain lesions and cannot be recommended as part of a routine brain MRI protocol in dogs and cats with suspected brain lesions.

Unified detection and tracking of instruments during retinal microsurgery

Methods for tracking an object have generally fallen into two groups: tracking by detection and tracking through local optimization. The advantage of detection-based tracking is its ability to deal with target appearance and disappearance, but it does not naturally take advantage of target motion continuity during detection. The advantage of local optimization is efficiency and accuracy, but it requires additional algorithms to initialize tracking when the target is lost. To bridge these two approaches, we propose a framework for unified detection and tracking as a time-series Bayesian estimation problem. The basis of our approach is to treat both detection and tracking as a sequential entropy minimization problem, where the goal is to determine the parameters describing a target in each frame. To do this we integrate the Active Testing (AT) paradigm with Bayesian filtering, and this results in a framework capable of both detecting and tracking robustly in situations where the target object enters and leaves the field of view regularly. We demonstrate our approach on a retinal tool tracking problem and show through extensive experiments that our method provides an efficient and robust tracking solution.

Childhood cancer and residential exposure to highways: a nationwide cohort study.

Children living near highways are exposed to higher concentrations of traffic-related carcinogenic pollutants. Several studies reported an increased risk of childhood cancer associated with traffic exposure, but the published evidence is inconclusive. We investigated whether cancer risk is associated with proximity of residence to highways in a nation-wide cohort study including all children aged <16 years from Swiss national censuses in 1990 and 2000. Cancer incidence was investigated in time to event analyses (1990-2008) using Cox proportional hazards models and incidence density analyses (1985-2008) using Poisson regression. Adjustments were made for socio-economic factors, ionising background radiation and electromagnetic fields. In time to event analysis based on 532 cases the adjusted hazard ratio for leukaemia comparing children living <100 m from a highway with unexposed children (≥500 m) was 1.43 (95 % CI 0.79, 2.61). Results were similar in incidence density analysis including 1367 leukaemia cases (incidence rate ratio (IRR) 1.57; 95 % CI 1.09, 2.25). Associations were similar for acute lymphoblastic leukaemia (IRR 1.64; 95 % CI 1.10, 2.43) and stronger for leukaemia in children aged <5 years (IRR 1.92; 95 % CI 1.22, 3.04). Little evidence of association was found for other tumours. Our study suggests that young children living close to highways are at increased risk of developing leukaemia.