Marburg virus (MARV) infection is a lethal hemorrhagic fever for which no licensed vaccines or therapeutics are available. Development of appropriate medical countermeasures requires a thorough ...understanding of the interaction between the host and the pathogen and the resulting disease course. In this study, 15 rhesus macaques were sequentially sacrificed following aerosol exposure to the MARV variant Angola, with longitudinal changes in physiology, immunology, and histopathology used to assess disease progression. Immunohistochemical evidence of infection and resulting histopathological changes were identified as early as day 3 postexposure (p.e.). The appearance of fever in infected animals coincided with the detection of serum viremia and plasma viral genomes on day 4 p.e. High (>10(7) PFU/ml) viral loads were detected in all major organs (lung, liver, spleen, kidney, brain, etc.) beginning day 6 p.e. Clinical pathology findings included coagulopathy, leukocytosis, and profound liver destruction as indicated by elevated liver transaminases, azotemia, and hypoalbuminemia. Altered cytokine expression in response to infection included early increases in Th2 cytokines such as interleukin 10 (IL-10) and IL-5 and late-stage increases in Th1 cytokines such as IL-2, IL-15, and granulocyte-macrophage colony-stimulating factor (GM-CSF). This study provides a longitudinal examination of clinical disease of aerosol MARV Angola infection in the rhesus macaque model.
In this study, we carefully analyzed the timeline of Marburg virus infection in nonhuman primates in order to provide a well-characterized model of disease progression following aerosol exposure.
One application of nanocopper is as a wood‐preserving pesticide in pressure‐treated lumber. Recent research has shown that pressure‐treated lumber amended with micronized copper azole (MCA), which ...contains nanosized copper, releases copper under estuarine and marine conditions. The form of copper released (i.e., ionic, nanocopper 1–100 nm in size) is not fully understood but will affect the bioavailability and toxicity of the metal. In the present study, multiple lines of evidence, including size fractionation, ion‐selective electrode electrochemistry, comparative toxicity, and copper speciation were used to determine the form of copper released from lumber blocks and sawdust. The results of all lines of evidence supported the hypothesis that ionic copper was released from MCA lumber and sawdust, with little evidence that nanocopper was released. For example, copper concentrations in size fractionations of lumber block aqueous leachates including unfiltered, 0.1 μm, and 3 kDa were not significantly different, suggesting that the form of copper released was in the size range operationally defined as dissolved. These results correlated with the ion‐selective electrode data which detects only ionic copper. In addition, comparative toxicity testing resulted in a narrow range of median lethal concentrations (221–257 μg/L) for MCA lumber blocks and CuSO4. We conclude that ionic copper was released from the nanocopper pressure‐treated lumber under estuarine and marine conditions. Environ Toxicol Chem 2018;37:1969–1979. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Amyotrophic Lateral Sclerosis is characterized by a focal onset of symptoms followed by a progressive spread of pathology that has been likened to transmission of infectious prions. Cell-to-cell ...transmission of SOD1 protein aggregates is dependent on fluid-phase endocytosis pathways, although the precise molecular mechanisms remain to be elucidated.
We demonstrate in this paper that SOD1 aggregates interact with the cell surface triggering activation of Rac1 and subsequent membrane ruffling permitting aggregate uptake via stimulated macropinocytosis. In addition, other protein aggregates, including those associated with neurodegenerative diseases (TDP-43, Httex146Q, α-synuclein) also trigger membrane ruffling to gain entry into the cell. Aggregates are able to rupture unstructured macropinosomes to enter the cytosol allowing propagation of aggregation to proceed.
Thus, we conclude that in addition to basic proteostasis mechanisms, pathways involved in the activation of macropinocytosis are key determinants in the spread of pathology in these misfolding diseases.
Choroidal neovascularization (CNV) is the leading cause of blindness in age-related macular degeneration (AMD). Several lines of evidence implicate increased levels of vascular endothelial growth ...factor (VEGF) in retinal pigment epithelium (RPE) from patients with AMD. Current approaches to attenuate VEGF or its receptors, including the use of small interfering (si)RNA, show significant promise, but still have limited efficacy and require repeat administrations, using procedures associated with multiple complications. The goal of this study was to develop an approach for long-term endogenous expression of short hairpin (sh)RNA that would significantly attenuate VEGF and hence act as a potential therapy for AMD.
Several shRNAs expressed from recombinant adenovirus were developed. These shRNAs were expressed in human RPE cells in the presence of adenovirus vectors overexpressing VEGF, and the amount of VEGF attenuation was evaluated. Adenovirus vectors expressing VEGF were subsequently injected into the subretinal space of mice, and induction of CNV was measured in the presence of adenovirus vectors expressing shRNA targeting VEGF.
Potent shRNA sequences were identified that were able to silence VEGF in human RPE cells. When expressed from adenovirus backbones, these shRNA constructs silenced VEGF by 94% at a 1:5 molar ratio (VEGF to shRNA) and 64% at a 1:0.05 molar ratio. Adenovirus vectors expressing high levels of VEGF could induce CNV in mice within 5 days. Co-injection of VEGF-expressing viruses into mice with shRNA targeting VEGF led to a substantial (84%) reduction in CNV.
shRNA targeting VEGF from adenovirus vectors allows potent attenuation of VEGF and prevents CNV. This approach shows promise as a therapy for AMD.
New joint replacement prostheses are being continually introduced into the market. The underlying purpose of the introduction of new devices is to improve patient outcomes. This study was undertaken ...to determine how many new prostheses were associated with improved patient outcomes.
Data were obtained from a comprehensive national database. Outcome analysis was performed on all new hip and knee prostheses introduced into the market between January 1, 2003, and December 31, 2007, and used on at least 100 occasions. The findings were compared with the combined results of the three best performing established hip and knee prostheses with a minimum duration of follow-up of five years. The principal outcome measures were the rate of revision per observed component years and the time to first revision, with use of Kaplan-Meier estimates of implant survivorship.
Most prostheses introduced into the market during the study period were used on fewer than 100 occasions. Analysis of those that had been used in a sufficient number of procedures showed that 27% (nine of thirty-three) of the hip replacements and 29% (eight of twenty-eight) of the knee replacements had a significantly higher rate of revision than the established prostheses. None of the newer prostheses had a lower rate of revision than the established prostheses.
This study indicates that there was no benefit to the introduction of new prostheses into this national market during the five-year study period. Importantly, 30% of the new prostheses were associated with a significantly worse outcome compared with the prostheses with a minimal duration of follow-up of five years.
Apoptosis is a fundamental process required for normal development of the nervous system and is triggered during neurodegenerative disease. To dissect the molecular events leading to neuronal cell ...death, we have developed a cell-free model of neuronal apoptosis. The model faithfully reproduces key elements of apoptosis, including chromatin condensation, DNA fragmentation, caspase activation/processing, and selective substrate cleavage. We report that cell-free apoptosis is activated in premitochondrial, mitochondrial, and postmitochondrial phases by tamoxifen, mastoparan, and cytochrome c, respectively, allowing a functional ordering of these proapoptotic modulators. Furthermore, this is the first report of mitochondrial-mediated activation of cell-free apoptosis in a cell extract. Although Bcl-2 blocks activation at the premitochondrial and mitochondrial levels, it does not affect the postmitochondrial level. The cell-free system described here provides a valuable tool to elucidate the molecular events leading to neuronal cell death.
Copper is a well-known toxic metal to marine organisms. In this investigation, we measured and compared the acute toxicity of several forms of copper (including nanocopper) amended into a marine ...sediment with mysids and amphipods. For all the forms of copper tested, toxicity, measured as the LC50, ranged from 708 to > 2400 mg Cu/kg (dry sediment) for mysids and 258 to 1070 mg Cu/kg (dry sediment) for amphipods.
Abstract Policymakers and accrediting bodies have recognized the importance of integrating public health, population health, and prevention into graduate medical education programs. The high ...prevalence of chronic illness, coupled with the impact of behavioral and societal determinants of health, necessitate an urgent call for family medicine residencies to prepare future leaders to meet these challenges. The University of Massachusetts Worcester Family Medicine Residency recently developed an integrated curriculum that strives to develop a culture of incorporating fundamental public health principles into everyday practice. This public health curriculum was designed to integrate new topics within the current residency structure through longitudinal and concentrated experiences. This strategy has substantially improved public health and prevention education without substantial impact on the already strained residency curricular structure. This paper describes the integration of public health and prevention education into a family medicine residency to help residents acquire the fundamental skills necessary to improve a population's health.
PDF
