An update on pathobiologic roles of anti-glycan antibodies in Guillain-Barré syndrome.

Anti-glycan antibodies directed against gangliosides are now considered the major immune effectors that induce damage to intact nerve fibers in some variants of the monophasic neuropathic disorders that comprise Guillain-Barré syndrome. Recent experimental studies elucidating the complexity of anti-glycan antibody-mediated pathobiologic effects on intact and injured nerves undergoing repair are discussed.

Neuronal and axonal degeneration in experimental spinal cord injury: in vivo proton magnetic resonance spectroscopy and histology.

Longitudinal in vivo proton magnetic resonance spectroscopy (1H-MRS) and immunohistochemistry were performed to investigate the tissue degeneration in traumatically injured rat spinal cord rostral and caudal to the lesion epicenter. On 1H-MRS significant decreases in N-acetyl aspartate (NAA) and total creatine (Cr) levels in the rostral, epicenter, and caudal segments were observed by 14 days, and levels remained depressed up to 56 days post-injury (PI). In contrast, the total choline (Cho) levels increased significantly in all three segments by 14 days PI, but recovered in the epicenter and caudal, but not the rostral region, at 56 days PI. Immunohistochemistry demonstrated neuronal cell death in the gray matter, and reactive astrocytes and axonal degeneration in the dorsal, lateral, and ventral white-matter columns. These results suggest delayed tissue degeneration in regions both rostrally and caudally from the epicenter in the injured spinal cord tissue. A rostral-caudal asymmetry in tissue recovery was seen both on MRI-observed hyperintense lesion volume and the Cho, but not NAA and Cr, levels at 56 days PI. These studies suggest that dynamic metabolic changes take place in regions away from the epicenter in injured spinal cord.

Reduced vascular endothelial growth factor expression in contusive spinal cord injury.

Vascular endothelial growth factor (VEGF) is being investigated as a potential interventional therapy for spinal cord injury (SCI). In the current study, we examined SCI-induced changes in VEGF protein levels using Western blot analysis around the epicenter of injury. Our results indicate a significant decrease in the levels of VEGF(165) and other VEGF isoforms at the lesion epicenter 1 day after injury, which was maintained up to 1 month after injury. We also examined if robust VEGF(165) decrease in injured spinal cords affects neuronal survival, given that a number of reported studies show neuroprotective effect of this VEGF isoform. However, exogenously administered VEGF(165) at the time of injury did not affect the number of sparred neurons. In contrast, exogenous administration of VEGF antibody that inhibits actions of not only VEGF(165) but also of several other VEGF isoforms, significantly decreased number of sparred neurons after SCI. Together these results indicate a general reduction of VEGF isoforms following SCI and that isoforms other than VEGF(165) (e.g., VEGF(121) and/or VEGF(189)) provide neuroprotection, suggesting that VEGF(165) isoform is likely involved in other pathophysiological process after SCI.

Minimizing radiation injury and neoplastic effects during pediatric fluoroscopy: what should we know?

Radiation-induced injuries from fluoroscopic procedures in pediatric patients have occurred, and young patients are at greatest risk of many radiation-induced neoplasms. Some fluoroscopists have been injured from their use of fluoroscopy, and they are known to be at risk of radiation-induced neoplasm when radiation is not well-controlled. This article reviews the circumstances that lead to radiation injury and delineates some procedural methods to avoid injury and limit radiation exposure to both the patient and the fluoroscopist.

Traumatic brain injury stimulates hippocampal catechol-O-methyl transferase expression in microglia.

Outcome following traumatic brain injury (TBI) is in large part determined by the combined action of multiple processes. In order to better understand the response of the central nervous system to injury, we utilized an antibody array to simultaneously screen 507 proteins for altered expression in the injured hippocampus, a structure critical for memory formation. Array analysis indicated 41 candidate proteins have altered expression levels 24h after TBI. Of particular interest was catechol-O-methyl transferase (COMT), an enzyme involved in metabolizing catecholamines released following neuronal activity. Altered catecholamine signaling has been observed after brain injury, and may contribute to the cognitive dysfunctions and behavioral deficits often experienced after TBI. Our data shows that COMT expression in the injured ipsilateral hippocampus was elevated for at least 14 d after controlled cortical impact injury. We found strong co-localization of COMT immunoreactivity with the microglia marker Iba1 near the injury site. Since dopamine transporter expression has been reported to be down-regulated after brain injury, COMT-mediated catecholamine metabolism may play a more prominent role in terminating catecholamine signaling in injured areas.

Emergency stabilization of the pelvic ring: Clinical comparison between three different techniques

Background: Emergency devices for pelvic ring stabilization include circumferential sheets, pelvic binders, and c-clamps. Our knowledge of the outcome of these techniques is currently based on limited information. Methods: Using the dataset of the German Pelvic Trauma Registry, demographic and injury-associated characteristics as well as the outcome of pelvic fracture patients after sheet, binder, and c-clamp treatment was compared. Outcome parameters included transfusion requirement of packed red blood cells, length of hospital stay, mortality, and incidence of lethal pelvic bleeding. Results: Two hundred seven of 6137 (3.4%) patients documented in the German Pelvic Trauma Registry between April 30th 2004 and January 19th 2012 were treated by sheets, binders, or c-clamps. In most cases, c-clamps (69%) were used, followed by sheets (16%), and binders (15%). The median age was significantly lower in patients treated with binders than in patients treated with sheets or c-clamps (26 vs. 47 vs. 42 years, p = 0.01). Sheet wrapping was associated with a significantly higher incidence of lethal pelvic bleeding compared to binder or c-clamp stabilization (23% vs. 4% vs. 8%). No significant differences between the study groups were found in sex, fracture type, blood haemoglobin concentration, arterial blood pressure, Injury Severity Score, the incidence of additional pelvic packing and arterial embolization, need of red blood cell transfusion, length of hospitalisation, and mortality. Conclusions: The data suggest that emergency stabilization of the pelvic ring by binders and c-clamps is associated with a lower incidence of lethal pelvic bleeding compared to sheet wrapping.

Intra- and postoperative complications of navigated and conventional techniques in percutaneous iliosacral screw fixation after pelvic fractures: Results from the German Pelvic Trauma Registry

Background: Percutaneous iliosacral screw placement following pelvic trauma is a very demanding technique involving a high rate of screw malpositions possibly associated with the risk of neurological damage or inadequate stability. In the conventional technique, the screw’s correct entry point and the small target corridor for the iliosacral screw may be difficult to visualise using an image intensifier. 2D and 3D navigation techniques may therefore be helpful tools. The aim of this multicentre study was to evaluate the intra- and postoperative complications after percutaneous screw implantation by classifying the fractures using data from a prospective pelvic trauma registry. The a priori hypothesis was that the navigation techniques have lower rates of intraoperative and postoperative complications. Methods: This study is based on data from the prospective pelvic trauma registry introduced by the German Society of Traumatology and the German Section of the AO/ASIF International in 1991. The registry provides data on all patients with pelvic fractures treated between July 2008 and June 2011 at any one of the 23 Level I trauma centres contributing to the registry. Results: A total of 2615 patients were identified. Out of these a further analysis was performed in 597 patients suffering injuries of the SI joint (187 � with surgical interventions) and 597 patients with sacral fractures (334 � with surgical interventions). The rate of intraoperative complications was not significantly different, with 10/114 patients undergoing navigated techniques (8.8%) and 14/239 patients in the conventional group (5.9%) for percutaneous screw implantation (p = 0.4242). Postoperative complications were analysed in 30/114 patients in the navigated group (26.3%) and in 70/239 patients (29.3%) in the conventional group (p = 0.6542). Patients who underwent no surgery had with 66/197 cases (33.5%) a relatively high rate of complications during their hospital stay. The rate of surgically-treated fractures was higher in the group with more unstable Type-C fractures, but the fracture classification had no significant influence on the rate of complications. Discussion: In this prospective multicentre study, the 2D/3D navigation techniques revealed similar results for the rate of intraoperative and postoperative complications compared to the conventional technique. The rate of neurological complications was significantly higher in the navigated group.

Long-term injury induced plasticity in {\it Aplysia\/} neurons: Behavioral, electrophysiological, and morphological studies

Nerve injury is known to produce a variety of electrophysiological and morphological neuronal alterations (reviewed by Titmus and Faber, 1990; Bulloch and Ridgeway, 1989; Walters, 1994). Determining if these alterations are adaptive and how they are activated and maintained could provide important insight into basic cellular mechanisms of injury-induced plasticity. Furthermore, characterization of injury-induced plasticity provides a useful assay system for the identification of possible induction signals underlying these neuronal changes. Understanding fundamental mechanisms and underlying induction signals of injury-induced neuronal plasticity could facilitate development of treatment strategies for neural injury and neuropathic pain in humans.^ This dissertation characterizes long-lasting, injury-induced neuronal alterations using the nervous system of Aplysia californica as a model. These changes are examined at the behavioral, electrophysiological, and morphological levels. Injury-induced changes in the electrophysiological properties of neurons were found that increased the signaling effectiveness of the injured neurons. This increase in signalling effectiveness could act to compensate for partial destruction of the injured neuron's peripheral processes. Recovery of a defensive behavioral response which serves to protect the animal from further injury was found within 2 weeks of injury. For the behavioral recovery to occur, new neural pathways must have been formed between the denervated area and the CNS. This was found to be mediated at least in part by new axonal growth which extended from the injured cell back along the original pathway (i.e. into the injured nerve). In addition, injury produced central axonal sprouting into different nerves that do not usually contain the injured neuron's axons. This could be important for (i) finding alternative pathways to the periphery when the original pathways are impassable and (ii) the formation of additional synaptic connections with post-synaptic targets which would further enhance the signalling effectiveness of the injured cell. ^

Traumatic brain injury (TBI) produces cytoskeletal protein derangements within cortical neurons that can be attenuated by protease inhibition

TBI produces a consistent and extensive loss of neurofilament 68 (NF68) and neurofilament 200 (NF200), key intermediate cytoskeletal proteins found in neurons including axons and dendrites, in cortical samples from injured brain. The presence of low molecular weight NF68 breakdown products (BDPs) strongly suggest that calpain proteolysis at least in part contributes to neurofilament (NF) protein loss following injury. Furthermore, one and two-dimensional gel electrophoresis analyses of NF BDPs obtained from in situ and in vitro tissue also implicated the involvement of calpain 2 mediated proteolysis of neurofilaments following TBI. Immunohistochemical examination of derangements in cytoskeletal proteins following traumatic brain injury in rats indicated that preferential dendritic rather than axonal damage occurs within three hours post-TBI. Although proteolysis of cytoskeletal proteins occurred concurrently with early morphological alterations, evidence of proteolysis preceded the full expression of evolutionary histopathological changes. Furthermore, cytoskeletal immunofluorescence alterations were not restricted to the site of impact. Confocal microscopic investigations of NF68 and NF200 immunofluorescence within injured cortical neurons revealed alterations in neurofilament assembly in the absence of NF derangements detectable at the light microscopic level ($<$15 minutes post-TBI). Collectively immunohistochemistry studies suggest that derangements to neuronal processes are biochemical and evolutionary in nature, and not due solely to mechanical shearing. Importantly, a systemically administered calpain inhibitor (calpain inhibitor 2) significantly reduced NF200, NF68, and spectrin protein loss as well as providing marked preservation of NF proteins in neuronal somata, dendrites, and axons at 24 hours post-TBI. ^

Infection Prevention in the Emergency Department.

Infection prevention remains a major challenge in emergency care. Acutely ill and injured patients seeking evaluation and treatment in the emergency department (ED) not only have the potential to spread communicable infectious diseases to health care personnel and other patients, but are vulnerable to acquiring new infections associated with the care they receive. This article will evaluate these risks and review the existing literature for infection prevention practices in the ED, ranging from hand hygiene, standard and transmission-based precautions, health care personnel vaccination, and environmental controls to strategies for preventing health care-associated infections. We will conclude by examining what can be done to optimize infection prevention in the ED and identify gaps in knowledge where further research is needed. Successful implementation of evidence-based practices coupled with innovation of novel approaches and technologies tailored specifically to the complex and dynamic environment of the ED are the keys to raising the standard for infection prevention and patient safety in emergency care.

Being Moved by the Self and Others: Influence of Empathy on Self-Motion Perception

BACKGROUND: The observation of conspecifics influences our bodily perceptions and actions: Contagious yawning, contagious itching, or empathy for pain, are all examples of mechanisms based on resonance between our own body and others. While there is evidence for the involvement of the mirror neuron system in the processing of motor, auditory and tactile information, it has not yet been associated with the perception of self-motion. METHODOLOGY/PRINCIPAL FINDINGS: We investigated whether viewing our own body, the body of another, and an object in motion influences self-motion perception. We found a visual-vestibular congruency effect for self-motion perception when observing self and object motion, and a reduction in this effect when observing someone else's body motion. The congruency effect was correlated with empathy scores, revealing the importance of empathy in mirroring mechanisms. CONCLUSIONS/SIGNIFICANCE: The data show that vestibular perception is modulated by agent-specific mirroring mechanisms. The observation of conspecifics in motion is an essential component of social life, and self-motion perception is crucial for the distinction between the self and the other. Finally, our results hint at the presence of a "vestibular mirror neuron system".

Neuroprotective effect of cathodal transcranial direct current stimulation in a rat stroke model

Experimental focal brain ischemia generates in the penumbra recurrent depolarizations which spread across the injured cortex inducing infarct growth. Transcranial direct current stimulation can induce a lasting, polarity-specific, modulation of cortical excitability. To verify whether cathodal transcranial direct current stimulation could reduce the infarct size and the number of depolarizations, focal ischemia was induced in the rat by the 3 vessels occlusion technique. In the first experiment 12 ischemic rats received cathodal stimulation (alternating 15min on and 15min off) starting 45min after middle cerebral artery occlusion and lasting 4h. In the second experiment 12 ischemic rats received cathodal transcranial direct current stimulation with the same protocol but starting soon after middle cerebral artery occlusion and lasting 6h. In both experiments controls were 12 ischemic rats not receiving stimulation. Cathodal stimulation reduced the infarct volume in the first experiment by 20% (p=0.002) and in the second by 30% (p=0.003). The area of cerebral infarction was smaller in animals receiving cathodal stimulation in both experiments (p=0.005). Cathodal stimulation reduced the number of depolarizations (p=0.023) and infarct volume correlated with the number of depolarizations (p=0.048). Our findings indicate that cathodal transcranial direct current stimulation exert a neuroprotective effect in the acute phase of stroke possibly decreasing the number of spreading depolarizations. These findings may have translational relevance and open a new avenue in neuroprotection of stroke in humans.

A Comparison of Complications in 400 Patients After Native Nail Versus Silicone Nail Splints for Fingernail Splinting After Injuries

BACKGROUND The fingertip is the most commonly injured part of the hand and is an important aesthetic part of the hand. METHODS In this retrospective study we analyzed data from 700 patients operated on between 1997 and 2008 for complications after nail splinting with native nail or silicone nail. Inclusion criteria were patients living in Bern/Berner Land, complete documentation, same surgical team, standard antibiotics, acute trauma, no nail bed transplantation, and no systemic diseases. Groups were analyzed for differences in age, gender, cause and extension of trauma, bony injury and extent, infection, infectious agent, and nail deformities. Statistical analysis was done using the χ (2) test, Fisher's exact test, and Pearson correlation coefficients. RESULTS A total of 401 patients, with a median age of 39.5 years, were included. There were more men with injured nails. Two hundred forty native nails and 161 silicone splints were used. There were 344 compression injuries, 44 amputations, and 13 avulsion injuries. Forty-three patients had an infection, with gram-positive bacteria (Staphylococcus aureus) causing most infections. A total of 157 nail dystrophies were observed, split nails most often. The native nail splint group showed significantly (p < 0.015) fewer nail deformities than the silicone nail splint group; otherwise, there were no statistical differences. However, there were twice as many infections in the silicone nail group. CONCLUSION It seems to be advantageous to use the native nail for splinting after trauma, when possible. In case of a destroyed and unusable nail plate, a nail substitute has to be used.

Long-distance photogrammetric trait estimation in free-ranging animals: A new approach

The acquisition of accurate information on the size of traits in animals is fundamental for the study of animal ecology and evolution and their management. We demonstrate how morphological traits of free-ranging animals can reliably be estimated on very large observation distances of several hundred meters by the use of ordinary digital photographic equipment and simple photogrammetric software. In our study, we estimated the length of horn annuli in free-ranging male Alpine ibex (Capra ibex) by taking already measured horn annuli of conspecifics on the same photographs as scaling units. Comparisons with hand-measured horn annuli lengths and repeatability analyses revealed a high accuracy of the photogrammetric estimates. If length estimations of specific horn annuli are based on multiple photographs measurement errors of <5.5 mm can be expected. In the current study the application of the described photogrammetric procedure increased the sample size of animals with known horn annuli length by an additional 104%. The presented photogrammetric procedure is of broad applicability and represents an easy, robust and cost-efficient method for the measuring of individuals in populations where animals are hard to capture or to approach.

Radialer externer Fixateur zur geschlossenen Behandlung problematischer suprakondylärer Humerusfrakturen Typ III und IV bei Kindern und Jugendlichen

Operationsziel Geschlossene, anatomische Reposition und sichere Fixation von problematischen suprakondylären Typ-III- und Typ-IV-Humerusfrakturen, die mit den herkömmlichen Operationsmethoden nur schwierig geschlossen zu behandeln sind. Indikationen Gemäß der AO-Kinderklassifikation der suprakondylären Humerusfrakturen vom Typ III und IV: Frakturen, welche nicht geschlossen mittels üblicher Repositionsmethoden reponierbar sind sowie Frakturen, die nicht mittels der üblichen, gekreuzten perkutanen Kirschner-Draht-Technik zu fixieren sind. Bei schweren Schwellungszuständen, offener Fraktur oder initial neurologischen und/oder vaskulären Problemen („pulseless pink hand“) sowie bei mehrfachverletzten Kindern, welche eine optimale Rehabilitation benötigen und die Extremität gipsfrei sein sollte. Bei Kindern mit Komorbiditäten (z. B. Anfälle, Spastizität), die eine bessere Stabilität benötigen. Kontraindikationen Prinzipiell keine Kontraindikationen Operationstechnik Im nichtreponierten Zustand unter Durchleuchtungskontrolle Einbringen einer einzelnen Schanz-Schraube in den lateralen (radialen) Aspekt des distalen Fragments, welches sich in der streng seitlichen Röntgenprojektion als „Sand-Uhr“- bzw. Kreisform des Capitulum humeri darstellt. Je nach Größe dieses distalen Fragments kann die Schanz-Schraube rein epiphysär oder metaphysär liegen. Danach in absolut streng seitlicher Projektion des distalen Humerus im Bereich des meta-diaphysären Übergangs Einbohren einer 2. Schanz-Schraube unabhängig von der Ersten, die möglichst rechtwinklig zur Längsachse des Humerus in der a.-p.-Ebene zu liegen kommen sollte, um spätere Manipulationen mittels „Joy-Stick“-Technik zu erleichtern. Sind die beiden Schanz-Schrauben mehr oder weniger in beiden Ebenen parallel, so ist die Fraktur praktisch anatomisch reponiert. Nach erreichter Reposition Feinjustierung aller Achskomponenten. Sicherung der Flexion/Extension mittels einem von radial, distal eingebrachten sog. Anti-Rotations-Kirschner-Drahts, der die Stabilität signifikant erhöht und eine Drehung des distalen Fragments um die einzelne Schanz-Schraube verhindert. Postoperative Behandlung Keine zusätzliche Gipsruhigstellung notwendig. Es sollte eine funktionelle Nachbehandlung erfolgen. Ergebnisse Gemäß unserer Langzeitstudien bewegen die meisten Kinder bereits zum Zeitpunkt der ambulanten Pin-Entfernung in der Frakturambulanz ihren Ellbogen weitgehend normal. Bei einer Follow-up-Zeit über 40 Monate hatten 30/31 Kindern eine seitengleiche Achse und Beweglichkeit.