Canine distemper virus persistence in demyelinating encephalitis by swift intracellular cell-to-cell spread in astrocytes is controlled by the viral attachment protein

The mechanism of viral persistence, the driving force behind the chronic progression of inflammatory demyelination in canine distemper virus (CDV) infection, is associated with non-cytolytic viral cell-to-cell spread. Here, we studied the molecular mechanisms of viral spread of a recombinant fluorescent protein-expressing virulent CDV in primary canine astrocyte cultures. Time-lapse video microscopy documented that CDV spread was very efficient using cell processes contacting remote target cells. Strikingly, CDV transmission to remote cells could occur in less than 6 h, suggesting that a complete viral cycle with production of extracellular free particles was not essential in enabling CDV to spread in glial cells. Titration experiments and electron microscopy confirmed a very low CDV particle production despite higher titers of membrane-associated viruses. Interestingly, confocal laser microscopy and lentivirus transduction indicated expression and functionality of the viral fusion machinery, consisting of the viral fusion (F) and attachment (H) glycoproteins, at the cell surface. Importantly, using a single-cycle infectious recombinant H-knockout, H-complemented virus, we demonstrated that H, and thus potentially the viral fusion complex, was necessary to enable CDV spread. Furthermore, since we could not detect CD150/SLAM expression in brain cells, the presence of a yet non-identified glial receptor for CDV was suggested. Altogether, our findings indicate that persistence in CDV infection results from intracellular cell-to-cell transmission requiring the CDV-H protein. Viral transfer, happening selectively at the tip of astrocytic processes, may help the virus to cover long distances in the astroglial network, “outrunning” the host’s immune response in demyelinating plaques, thus continuously eliciting new lesions

Guiding principles for the development and application of solid-phase phosphorus adsorbents for freshwater ecosystems

While a diverse array of phosphorus (P)-adsorbent materials is currently available for application to freshwater aquatic systems, selection of the most appropriate P-adsorbents remains problematic. In particular, there has to be a close correspondence between attributes of the P-adsorbent, its field performance, and the management goals for treatment. These management goals may vary from a rapid reduction in dissolved P to address seasonal enrichments from internal loading, targeting external fluxes due to anthropogenic sources, or long term inactivation of internal P inventories contained within bottom sediments. It also remains a challenge to develop new methods and materials that are ecologically benign and cost-effective. We draw on evidence in the literature and the authors’ personal experiences in the field, to summarise the attributes of a range of P-adsorbent materials. We offer 'guiding principles' to support practical use of existing materials and outline key development needs for new materials

Voxel-based statistical analysis of thalamic glucose metabolism in traumatic brain injury: relationship with consciousness and cognition

Objective: To study the relationship between thalamic glucose metabolism and neurological outcome after severe traumatic brain injury (TBI). Methods: Forty-nine patients with severe and closed TBI and 10 healthy control subjects with 18F-FDG PET were studied. Patients were divided into three groups: MCS&VS group (n ¼ 17), patients in a vegetative or a minimally conscious state; In-PTA group (n ¼ 12), patients in a state of post-traumatic amnesia (PTA); and Out-PTA group (n ¼ 20), patients who had emerged from PTA. SPM5 software implemented in MATLAB 7 was used to determine the quantitative differences between patients and controls. FDG-PET images were spatially normalized and an automated thalamic ROI mask was generated. Group differences were analysed with two sample voxel-wise t-tests. Results: Thalamic hypometabolism was the most prominent in patients with low consciousness (MCS&VS group) and the thalamic hypometabolism in the In-PTA group was more prominent than that in the Out-PTA group. Healthy control subjects showed the greatest thalamic metabolism. These differences in metabolism were more pronounced in the internal regions of the thalamus. Conclusions: The results confirm the vulnerability of the thalamus to suffer the effect of the dynamic forces generated during a TBI. Patients with thalamic hypometabolism could represent a sub-set of subjects that are highly vulnerable to neurological disability after TBI.Lull Noguera, N.; Noé, E.; Lull Noguera, JJ.; Garcia Panach, J.; Chirivella, J.; Ferri, J.; López-Aznar, D.... (2010). Voxel-based statistical analysis of thalamic glucose metabolism in traumatic brain injury: relationship with consciousness and cognition. Brain Injury. 24(9):1098-1107. doi:10.3109/02699052.2010.494592S10981107249Gallagher, C. N., Hutchinson, P. J., & Pickard, J. D. (2007). Neuroimaging in trauma. Current Opinion in Neurology, 20(4), 403-409. doi:10.1097/wco.0b013e32821b987bWoischneck, D., Klein, S., Rei�berg, S., D�hring, W., Peters, B., & Firsching, R. (2001). Classification of Severe Head Injury Based on Magnetic Resonance Imaging. Acta Neurochirurgica, 143(3), 263-271. doi:10.1007/s007010170106Grados, M. A. (2001). Depth of lesion model in children and adolescents with moderate to severe traumatic brain injury: use of SPGR MRI to predict severity and outcome. Journal of Neurology, Neurosurgery & Psychiatry, 70(3), 350-358. doi:10.1136/jnnp.70.3.350Meythaler, J. M., Peduzzi, J. D., Eleftheriou, E., & Novack, T. A. (2001). Current concepts: Diffuse axonal injury–associated traumatic brain injury. Archives of Physical Medicine and Rehabilitation, 82(10), 1461-1471. doi:10.1053/apmr.2001.25137Scheid, R., Walther, K., Guthke, T., Preul, C., & von Cramon, D. Y. (2006). Cognitive Sequelae of Diffuse Axonal Injury. Archives of Neurology, 63(3), 418. doi:10.1001/archneur.63.3.418Brandstack, N., Kurki, T., Tenovuo, O., & Isoniemi, H. (2006). MR imaging of head trauma: Visibility of contusions and other intraparenchymal injuries in early and late stage. Brain Injury, 20(4), 409-416. doi:10.1080/02699050500487951Xu, J., Rasmussen, I.-A., Lagopoulos, J., & Håberg, A. (2007). Diffuse Axonal Injury in Severe Traumatic Brain Injury Visualized Using High-Resolution Diffusion Tensor Imaging. Journal of Neurotrauma, 24(5), 753-765. doi:10.1089/neu.2006.0208Levine, B., Fujiwara, E., O’connor, C., Richard, N., Kovacevic, N., Mandic, M., … Black, S. E. (2006). In Vivo Characterization of Traumatic Brain Injury Neuropathology with Structural and Functional Neuroimaging. Journal of Neurotrauma, 23(10), 1396-1411. doi:10.1089/neu.2006.23.1396Metting, Z., Rödiger, L. A., De Keyser, J., & van der Naalt, J. (2007). Structural and functional neuroimaging in mild-to-moderate head injury. The Lancet Neurology, 6(8), 699-710. doi:10.1016/s1474-4422(07)70191-6Nakayama, N. (2006). Relationship between regional cerebral metabolism and consciousness disturbance in traumatic diffuse brain injury without large focal lesions: an FDG-PET study with statistical parametric mapping analysis. Journal of Neurology, Neurosurgery & Psychiatry, 77(7), 856-862. doi:10.1136/jnnp.2005.080523Nakayama, N. (2006). Evidence for white matter disruption in traumatic brain injury without macroscopic lesions. Journal of Neurology, Neurosurgery & Psychiatry, 77(7), 850-855. doi:10.1136/jnnp.2005.077875O’Leary, D. D. M., Schlaggar, B. L., & Tuttle, R. (1994). Specification of Neocortical Areas and Thalamocortical Connections. Annual Review of Neuroscience, 17(1), 419-439. doi:10.1146/annurev.ne.17.030194.002223Mitelman, S. A., Byne, W., Kemether, E. M., Newmark, R. E., Hazlett, E. A., Haznedar, M. M., & Buchsbaum, M. S. (2006). Metabolic thalamocortical correlations during a verbal learning task and their comparison with correlations among regional volumes. Brain Research, 1114(1), 125-137. doi:10.1016/j.brainres.2006.07.043Laureys, S., Faymonville, M., Luxen, A., Lamy, M., Franck, G., & Maquet, P. (2000). Restoration of thalamocortical connectivity after recovery from persistent vegetative state. The Lancet, 355(9217), 1790-1791. doi:10.1016/s0140-6736(00)02271-6Laureys, S., Goldman, S., Phillips, C., Van Bogaert, P., Aerts, J., Luxen, A., … Maquet, P. (1999). Impaired Effective Cortical Connectivity in Vegetative State: Preliminary Investigation Using PET. NeuroImage, 9(4), 377-382. doi:10.1006/nimg.1998.0414Laureys, S., Owen, A. M., & Schiff, N. D. (2004). Brain function in coma, vegetative state, and related disorders. The Lancet Neurology, 3(9), 537-546. doi:10.1016/s1474-4422(04)00852-xGuye, M., Bartolomei, F., & Ranjeva, J.-P. (2008). Imaging structural and functional connectivity: towards a unified definition of human brain organization? Current Opinion in Neurology, 24(4), 393-403. doi:10.1097/wco.0b013e3283065cfbPrice, C. J., & Friston, K. J. (2002). Functional Imaging Studies of Neuropsychological Patients: Applications and Limitations. Neurocase, 8(5), 345-354. doi:10.1076/neur.8.4.345.16186Kim, J., Avants, B., Patel, S., Whyte, J., Coslett, B. H., Pluta, J., … Gee, J. C. (2008). Structural consequences of diffuse traumatic brain injury: A large deformation tensor-based morphometry study. NeuroImage, 39(3), 1014-1026. doi:10.1016/j.neuroimage.2007.10.005Maxwell, W. L., MacKinnon, M. A., Smith, D. H., McIntosh, T. K., & Graham, D. I. (2006). Thalamic Nuclei After Human Blunt Head Injury. Journal of Neuropathology & Experimental Neurology, 65(5), 478-488. doi:10.1097/01.jnen.0000229241.28619.75SIDAROS, A., SKIMMINGE, A., LIPTROT, M., SIDAROS, K., ENGBERG, A., HERNING, M., … ROSTRUP, E. (2009). Long-term global and regional brain volume changes following severe traumatic brain injury: A longitudinal study with clinical correlates. NeuroImage, 44(1), 1-8. doi:10.1016/j.neuroimage.2008.08.030Ashburner, J., & Friston, K. J. (2000). Voxel-Based Morphometry—The Methods. NeuroImage, 11(6), 805-821. doi:10.1006/nimg.2000.0582Good, C. D., Johnsrude, I. S., Ashburner, J., Henson, R. N. A., Friston, K. J., & Frackowiak, R. S. J. (2001). A Voxel-Based Morphometric Study of Ageing in 465 Normal Adult Human Brains. NeuroImage, 14(1), 21-36. doi:10.1006/nimg.2001.0786Giacino, J. T., Ashwal, S., Childs, N., Cranford, R., Jennett, B., Katz, D. I., … Zasler, N. D. (2002). The minimally conscious state: Definition and diagnostic criteria. Neurology, 58(3), 349-353. doi:10.1212/wnl.58.3.349Gispert, J. ., Pascau, J., Reig, S., Martínez-Lázaro, R., Molina, V., García-Barreno, P., & Desco, M. (2003). Influence of the normalization template on the outcome of statistical parametric mapping of PET scans. NeuroImage, 19(3), 601-612. doi:10.1016/s1053-8119(03)00072-7Ashburner, J., & Friston, K. J. (1999). Nonlinear spatial normalization using basis functions. Human Brain Mapping, 7(4), 254-266. doi:10.1002/(sici)1097-0193(1999)7:43.0.co;2-gTzourio-Mazoyer, N., Landeau, B., Papathanassiou, D., Crivello, F., Etard, O., Delcroix, N., … Joliot, M. (2002). Automated Anatomical Labeling of Activations in SPM Using a Macroscopic Anatomical Parcellation of the MNI MRI Single-Subject Brain. NeuroImage, 15(1), 273-289. doi:10.1006/nimg.2001.0978Genovese, C. R., Lazar, N. A., & Nichols, T. (2002). Thresholding of Statistical Maps in Functional Neuroimaging Using the False Discovery Rate. NeuroImage, 15(4), 870-878. doi:10.1006/nimg.2001.1037LAUREYS, S., LEMAIRE, C., MAQUET, P., PHILLIPS, C., & FRANCK, G. (1999). Cerebral metabolism during vegetative state and after recovery to consciousness. Journal of Neurology, Neurosurgery & Psychiatry, 67(1), 121-122. doi:10.1136/jnnp.67.1.121Tommasino, C., Grana, C., Lucignani, G., Torri, G., & Fazio, F. (1995). Regional Cerebral Metabolism of Glucose in Comatose and Vegetative State Patients. Journal of Neurosurgical Anesthesiology, 7(2), 109-116. doi:10.1097/00008506-199504000-00006ANDERSON, C. V., WOOD, D.-M. G., BIGLER, E. D., & BLATTER, D. D. (1996). Lesion Volume, Injury Severity, and Thalamic Integrity following Head Injury. Journal of Neurotrauma, 13(2), 59-65. doi:10.1089/neu.1996.13.59Ge, Y., Patel, M. B., Chen, Q., Grossman, E. J., Zhang, K., Miles, L., … Grossman, R. I. (2009). Assessment of thalamic perfusion in patients with mild traumatic brain injury by true FISP arterial spin labelling MR imaging at 3T. Brain Injury, 23(7-8), 666-674. doi:10.1080/02699050903014899Uzan, M. (2003). Thalamic proton magnetic resonance spectroscopy in vegetative state induced by traumatic brain injury. Journal of Neurology, Neurosurgery & Psychiatry, 74(1), 33-38. doi:10.1136/jnnp.74.1.33OMMAYA, A. K., & GENNARELLI, T. A. (1974). CEREBRAL CONCUSSION AND TRAUMATIC UNCONSCIOUSNESS. Brain, 97(1), 633-654. doi:10.1093/brain/97.1.633Giacino, J., & Whyte, J. (2005). The Vegetative and Minimally Conscious States. Journal of Head Trauma Rehabilitation, 20(1), 30-50. doi:10.1097/00001199-200501000-00005Zeman, A. (2001). Consciousness. Brain, 124(7), 1263-1289. doi:10.1093/brain/124.7.1263Kinney, H. C., Korein, J., Panigrahy, A., Dikkes, P., & Goode, R. (1994). Neuropathological Findings in the Brain of Karen Ann Quinlan -- The Role of the Thalamus in the Persistent Vegetative State. New England Journal of Medicine, 330(21), 1469-1475. doi:10.1056/nejm199405263302101Saeeduddin Ahmed, Rex Bierley, Java. (2000). Post-traumatic amnesia after closed head injury: a review of the literature and some suggestions for further research. Brain Injury, 14(9), 765-780. doi:10.1080/026990500421886Wilson, J. T., Hadley, D. M., Wiedmann, K. D., & Teasdale, G. M. (1995). Neuropsychological consequences of two patterns of brain damage shown by MRI in survivors of severe head injury. Journal of Neurology, Neurosurgery & Psychiatry, 59(3), 328-331. doi:10.1136/jnnp.59.3.328Wilson, J. T., Teasdale, G. M., Hadley, D. M., Wiedmann, K. D., & Lang, D. (1994). Post-traumatic amnesia: still a valuable yardstick. Journal of Neurology, Neurosurgery & Psychiatry, 57(2), 198-201. doi:10.1136/jnnp.57.2.198Fearing, M. A., Bigler, E. D., Wilde, E. A., Johnson, J. L., Hunter, J. V., Xiaoqi Li, … Levin, H. S. (2008). Morphometric MRI Findings in the Thalamus and Brainstem in Children After Moderate to Severe Traumatic Brain Injury. Journal of Child Neurology, 23(7), 729-737. doi:10.1177/0883073808314159Little, D. M., Kraus, M. F., Joseph, J., Geary, E. K., Susmaras, T., Zhou, X. J., … Gorelick, P. B. (2010). Thalamic integrity underlies executive dysfunction in traumatic brain injury. Neurology, 74(7), 558-564. doi:10.1212/wnl.0b013e3181cff5d