Investigation of the pathogenesis of Saimiriine herpesvirus 1 in Balb/c mice

Scope and Method of Study: The purpose of this study was to investigate the pathogenesis of Saimiriine herpesvirus 1 (SaHV-1) infection by characterizing the clinical disease and gross and microscopic lesions in experimentally infected mice. To aid in the identification of anatomic sites of viral replication and to trace viral spread in experimentally infected mice, a green fluorescent protein (GFP)-expressing recombinant strain of SaHV-1 was constructed and used in subsequent inoculation studies. Mice were inoculated intramuscularly or epidermally with ten-fold dilutions of virus and sacrificed at 14 or 21 days in endpoint studies or on sequential days in temporal studies. Serum was tested by ELISA and tissues were examined microscopically with routine stains, immunohistochemistry, and confocal microscopy.Findings and Conclusions: SaHV-1 inoculation of Balb/c mice, either intramuscularly or epidermally, resulted in active infection as indicated by seroconversion, clinical disease, and gross and microscopic lesions. Mice inoculated intramuscularly initially developed skin lesions in the region of inoculation with subsequent development of paresis or paralysis of the inoculated hindlimb in animals receiving higher doses of virus. Lesions in these mice were restricted to the skin and thoracolumbar spinal cord and consisted of necrotizing dermatitis and segmental myelitis with neuronal necrosis. Mice inoculated with SaHV-1 via epidermal scarification developed a more rapidly progressive, severe disease that began in the inoculated epidermis and spread to involve thoracolumbar spinal cord, regional autonomic ganglia, and lower urinary tract. All mice receiving an infective dose of virus by this route developed ultimately fatal disease. GFP expression, indicating viral replication, corresponded with microscopic lesions and was present in keratinocytes of the epidermis, neurons of the dorsal root ganglia, spinal cord, sympathetic ganglia, and colonic myenteric plexus as well as epithelium of the lower urinary tract. SaHV-1 exhibited neurovirulence in Balb/c mice that varied significantly with the route of inoculation

A low-cost needle-based single-fiber reflectance spectroscopy method to probe scattering changes associated with mineralization in intervertebral discs in chondrodystrophoid canine species - A pilot study

Background and objectives: Intervertebral disc herniation is a common disease in chondrodystrophic dogs, and a similar neurologic condition also occurs in humans. Percutaneous laser disc ablation (PLDA) is a minimally invasive procedure used increasingly for prevention of disc herniation. PLDA is performed on thoracolumbar discs to which the same laser energy is applied regardless of their mineral content. Knowledge of individual disc mineral composition would allow laser energy dosage adjustments and more accurate treatment of degenerative discs. Usually, PLDA is guided by radiography/ fluoroscopy, which has a limited sensitivity of approximately 60 % for identification of mineralized discs. An imaging or sensing technology that provides a more accurate pre-operative in-situ assessment of the disc mineralization, and potentially rapid post-operative feedback, could optimize the outcome of the PLDA procedure. A sensing technology of needle-probing single-fiber reflectance (SFR) spectroscopy is therefore proposed that is considered to be compatible with PLDA work flow. The objective of this study was to demon strate the feasibility of this technology in assessing the increased light scattering associated with mineralization in intervertebral discs in chondrodystrophoid canine species. Materials and methods: A pilot study was performed on a total of 21 intervertebral discs from two cadaveric dogs ("Dog A" and "Dog B"). The discs were imaged by computed tomography (CT), radiography, and SFR spectroscopy, before histopathologic examination. SFR spectroscopy in the visible/near-infrared band was performed on the nucleus pulposus of the intervertebral disc through a 20-gauge spinal needle placed percutaneously for PLDA. A normalization method was applied to the raw remission spectra to extract a dimension-less and wavelength-dependent intensity profile in the 500 - 950 nm spectral range. Results: In total, six discs were determined to be degenerative on histopathology, five discs of "Dog A" and one disc of "Dog B". CT diagnosed all six degenerated discs, whereas radiography missed two of the five degenerated discs of " Dog A ". The wavelength-dependent mean scattering intensity profiles of the six degenerated discs were noticeably higher than the mean scattering intensity profiles of the 15 " normal " or insignificantly mineralized discs over the entire spectral range. The mean scattering intensities, averaged over each of the entire profiles, were 2.79 ± 0.58 (mean ± SD) for the six degenerated discs and 1.48 ± 0.37 for the 15 " normal " or insignificantly mineralized discs. A two-sample t -test showed p < 0.001 for the difference of the averaged scattering intensity between these both groups of discs. Conclusions: SFR spectroscopy measurements indicate that the increase of light scattering intensity across the entire 500 - 950 nm spectral range is associated with the mineralization in canine intervertebral discs. However, the scattering characteristics of the nucleus pulposus measured in this study may not necessarily represent the optical properties of the nucleus pulposus at the laser wavelength used for PLDA (2100 nm). More studies on cadaveric and eventually in-vivo samples are necessary before the clinical feasibility can be proved.Electrical and Computer EngineeringVeterinary Clinical Science

MicroRNA and mRNA expression profiling in rat acute respiratory distress syndrome

Background: Acute respiratory distress syndrome (ARDS) is characterized by pulmonary epithelial injury and extensive inflammation of the pulmonary parenchyma. Systematic analyses of microRNA (miRNA) and mRNA expression profiling in ARDS provide insights into understanding of molecular mechanisms of the pathogenesis of ARDS. The objective of this study was to identify miRNA and mRNA interactions in a rat model of ARDS by combining miRNA and mRNA microarray analyses.Methods: Rat model of ARDS was induced by saline lavage and mechanical ventilation. The expression profiles of both mRNAs and miRNAs in rat ARDS model were performed by microarray analyses. Microarray data were further verified by quantitative RT-PCR. Functional annotation on dys-regulated mRNAs and miRNAs was carried out by bioinformatics analysis.Results: The expression of 27 miRNAs and 37 mRNAs were found to be significantly changed. The selected miRNAs and genes were further verified by quantitative real-time PCR. The down-regulated miRNAs included miR-24, miR-26a, miR-126, and Let-7a, b, c, f. The up-regulated miRNAs were composed of miR-344, miR-346, miR-99a, miR-127, miR-128b, miR-135b, and miR-30a/b. Gene ontology and functional annotation analyses indicated that up-regulated mRNAs, such as Apc, Timp1, and Sod2, were involved in the regulation of apoptosis. Bioinformatics analysis showed the inverse correlation of altered miRNAs with the expression of their predicted target mRNAs. While Sod2 was inversely correlated with Let-7a, b, c, f., Ebf1 and Apc were inversely correlated with miR-24 and miR-26a, respectively. miR-26a, miR-346, miR-135b, miR-30a/b, miR-344, and miR-18a targeted multiple altered mRNAs. Gabrb1, Sod2, Eif2ak1, Fbln5, and Tspan8 were targeted by multiple altered miRNAs.Conclusion: The expressions of miRNAs and mRNAs were altered in a rat model of ARDS. The identified miRNA-mRNA pairs may play critical roles in the pathogenesis of ARDS.Peer reviewedPathobiologyOklahoma Center for Respiratory and Infectious DiseasesPhysiological Science

Ecosystem dynamics and management after forest die-off : A global synthesis with conceptual state-and-transition models

Broad-scale forest die-off associated with drought and heat has now been reported from every forested continent, posing a global-scale challenge to forest management. Climate-driven die-off is frequently compounded with other drivers of tree mortality, such as altered land use, wildfire, and invasive species, making forest management increasingly complex. Facing similar challenges, rangeland managers have widely adopted the approach of developing conceptual models that identify key ecosystem states and major types of transitions between those states, known as “state-and-transition models” (S&T models). Using expert opinion and available research, the development of such conceptual S&T models has proven useful in anticipating ecosystem changes and identifying management actions to undertake or to avoid. In cases where detailed data are available, S&T models can be developed into probabilistic predictions, but even where data are insufficient to predict transition probabilities, conceptual S&T models can provide valuable insights for managing a given ecosystem and for comparing and contrasting different ecosystem dynamics. We assembled a synthesis of 14 forest die-off case studies from around the globe, each with sufficient information to infer impacts on forest dynamics and to inform management options following a forest die-off event. For each, we developed a conceptual S&T model to identify alternative ecosystem states, pathways of ecosystem change, and points where management interventions have been, or may be, successful in arresting or reversing undesirable changes. We found that our diverse set of mortality case studies fit into three broad classes of ecosystem trajectories: (1) single-state transition shifts, (2) ecological cascading responses and feedbacks, and (3) complex dynamics where multiple interactions, mortality drivers, and impacts create a range of possible state transition responses. We integrate monitoring and management goals in a framework aimed to facilitate development of conceptual S&T models for other forest die-off events. Our results highlight that although forest die-off events across the globe encompass many different underlying drivers and pathways of ecosystem change, there are commonalities in opportunities for successful management intervention.Peer reviewe