Pathophysiology of Arbroviral Encephalitides in Laboratory Rodents

Western equine encephalitis virus (WEEV) is an arboviral pathogen naturally found in North America. The primary disease phenotype associated with WEEV infection in susceptible hosts is a relatively long prodromal period followed by viral encephalitis. By contrast, in the current work, experimental inoculation of WEEV into the peritoneum of Syrian golden hamsters produced rapid death within approximately 96 h. It was determined that direct virus killing of lymphoid cells leads to death in WEEV-infected Syrian golden hamsters, and that inflammatory cytokines have the potential to enhance virus-induced lymphoid cell destruction. It was further concluded that WEEV retains its ability to cause encephalitis in Syrian golden hamsters, if hamsters survive the early stages of virus infection or if virus is introduced directly into the CNS. Death in WEEV-infected hamsters is associated with lymphonecrotic lesions in the absence of pathological lesions in the central nervous system (CNS). Few clinical parameters were altered by WEEV infection, with the exception of circulating lymphocyte numbers. Circulating lymphocyte numbers decreased dramatically during WEEV infection, and lymphopenia was identified as a consistent indicator of eventual death. Virus infection also increased serum concentrations of the cytokines interferon and tumor necrosis factor-alpha (TNF-alpha). Hamster peritoneal macrophages exposed to WEEV expressed TNF-alpha in a dose-responsive manner. Macrophage expression of TNF-alpha could be significantly inhibited by treatment of cells with anti-inflammatory agents flunixin meglumine (FM) or dexamethasone (Dex). Anti-inflammatory treatment also protected macrophages from cytotoxicity associated with exposure to WEEV. Treatment of WEEV-infected hamsters with either FM or Dex significantly improved survival compared to placebo-treated controls. WEEV induced cytotoxicity in hamster splenocytes exposed to WEEV in a virus dose-responsive manner. Supernatant from WEEV-exposed macrophages significantly enhanced WEEV killing of splenocytes. Hamsters that survived the early stages of WEEV infection occasionally developed signs of neurological disease and died approximately 6 to 9 d after virus inoculation. These animals had histopathological lesions in the CNS consistent with alphavirus-induced encephalitis. Inoculation of WEEV directly into the CNS caused apparent encephalitic disease. Death following CNS inoculation of WEEV was rapid and concurrent with histopathological lesions in the CNS similar to lesions seen in encephalitic hamsters following peripheral inoculation

Distances to Populous Clusters in the LMC via the K-Band Luminosity of the Red Clump

We present results from a study of the distances and distribution of a sample of intermediate-age clusters in the Large Magellanic Cloud. Using deep near-infrared photometry obtained with ISPI on the CTIO 4m, we have measured the apparent K-band magnitude of the core helium burning red clump stars in 17 LMC clusters. We combine cluster ages and metallicities with the work of Grocholski & Sarajedini to predict each cluster's absolute K-band red clump magnitude, and thereby calculate absolute cluster distances. An analysis of these data shows that the cluster distribution is in good agreement with the thick, inclined disk geometry of the LMC, as defined by its field stars. We also find that the old globular clusters follow the same distribution, suggesting that the LMC's disk formed at about the same time as the globular clusters, ~ 13 Gyr ago. Finally, we have used our cluster distances in conjunction with the disk geometry to calculate the distance to the LMC center, for which we find (m-M)o = 18.40 +/- 0.04_{ran} +/- 0.08_{sys}, or Do = 47.9 +/- 0.9 +/- 1.8 kpc.Comment: 31 pages including 5 figures and 7 tables. Accepted for publication in the August 2007 issue of A

Evolution of eukaryotic transcription : insights from the genome of Giardia lamblia

Author Posting. © Cold Spring Harbor Laboratory Press, 2004. This article is posted here by permission of Cold Spring Harbor Laboratory Press for personal use, not for redistribution. The definitive version was published in Genome Research 14 (2004): 1537-1547, doi:10.1101/gr.2256604.The Giardia lamblia genome sequencing project affords us a unique opportunity to conduct comparative analyses of core cellular systems between early and late-diverging eukaryotes on a genome-wide scale. We report a survey to identify canonical transcription components in Giardia, focusing on RNA polymerase (RNAP) subunits and transcription-initiation factors. Our survey revealed that Giardia contains homologs to 21 of the 28 polypeptides comprising eukaryal RNAPI, RNAPII, and RNAPIII; six of the seven RNAP subunits without giardial homologs are polymerase specific. Components of only four of the 12 general transcription initiation factors have giardial homologs. Surprisingly, giardial TATA-binding protein (TBP) is highly divergent with respect to archaeal and higher eukaryotic TBPs, and a giardial homolog of transcription factor IIB was not identified. We conclude that Giardia represents a transition during the evolution of eukaryal transcription systems, exhibiting a relatively complete set of RNAP subunits and a rudimentary basal initiation apparatus for each transcription system. Most class-specific RNAP subunits and basal initiation factors appear to have evolved after the divergence of Giardia from the main eukaryotic line of descent. Consequently, Giardia is predicted to be unique in many aspects of transcription initiation with respect to paradigms derived from studies in crown eukaryotes.This work was supported in part by NIH grant AI43273 to M.L.S., by NIH grant AI51089 to A.G.M, and DOE grant DE-FG02-01ER63201 to G.J.O. Additional support was provided by the G. Unger Vetlesen Foundation and LI-COR Biotechnology

Channel catfish use higher coordination to capture prey than to swallow

When animals move they must coordinate motion among multiple parts of the musculoskeletal system. Different behaviours exhibit different patterns of coordination, however, it remains unclear what general principles determine the coordination pattern for a particular behaviour. One hypothesis is that speed determines coordination patterns as a result of differences in voluntary versus involuntary control. An alternative hypothesis is that the nature of the behavioural task determines patterns of coordination. Suction-feeding fishes have highly kinetic skulls and must coordinate the motions of over a dozen skeletal elements to draw fluid and prey into the mouth. We used a dataset of intracranial motions at five cranial joints in channel catfish (Ictalurus punctatus), collected using X-ray reconstruction of moving morphology, to test whether speed or task best explained patterns of coordination. We found that motions were significantly more coordinated (by 20–29%) during prey capture than during prey transport, supporting the hypothesis that the nature of the task determines coordination patterns. We found no significant difference in coordination between low- and high-speed motions. We speculate that capture is more coordinated to create a single fluid flow into the mouth while transport is less coordinated so that the cranial elements can independently generate multiple flows to reposition prey. Our results demonstrate the benefits of both higher and lower coordination in animal behaviours and the potential of motion analysis to elucidate motor tasks

Optimization of Ectopic Gene Expression in Skeletal Muscle Through DNA Transfer by Electroporation.

Background Electroporation (EP) is a widely used non-viral gene transfer method. We have attempted to develop an exact protocol to maximize DNA expression while minimizing tissue damage following EP of skeletal muscle in vivo. Specifically, we investigated the effects of varying injection techniques, electrode surface geometry, and plasmid mediums. Results We found that as the amount of damage increased in skeletal muscle in response to EP, the level of β-galactosidase (β-gal) expression drastically decreased and that there was no evidence of β-gal expression in damaged fibers. Two specific types of electrodes yielded the greatest amount of expression. We also discovered that DNA uptake in skeletal muscle following intra-arterial injection of DNA was significantly enhanced by EP. Finally, we found that DMSO and LipoFECTAMINE™, common enhancers of DNA electroporation in vitro, had no positive effect on DNA electroporationin vivo. Conclusions When injecting DNA intramuscularly, a flat plate electrode without any plasmid enhancers is the best method to achieve high levels of gene expression

Humanized Monoclonal Antibody against West Nile Virus Envelope Protein Administered after Neuronal Infection Protects against Lethal Encephalitis in Hamsters

Humans infected with West Nile virus (WNV) may clinically present with symptoms that are suggestive of neurological infection. Nearly all treatments of WNV disease have been effective in animal models only if administered before or soon after viral challenge. Here, we evaluated whether a potent neutralizing anti-WNV humanized monoclonal antibody (MAb), hE16, could improve the course of disease in a hamster model when administered after the virus had infected neurons in the brain. Five days after viral injection, WNV was detected in the brains of hamsters by cytopathic assay, quantitative reverse-transcription polymerase chain reaction, and immunohistochemical staining of WNV envelope in neurons. Notably, 80%–90% of the hamsters treated 5 days after viral injection by intraperitoneal injection with hE16 survived the disease, compared with 37% of the placebo-treated hamsters (P \u3c= .001). The hamsters that received hE16 directly in the brain also exhibited markedly improved survival rates, compared with those in the placebo-treated hamsters. In prospective experiments, hamsters with high levels of infectious WNV in their cerebrospinal fluid were also protected by hE16 when administered 5 days after viral injection. These experiments suggest that humanized MAbs with potent neutralizing activity are a possible treatment for human patients after WNV has infected neurons in the central nervous system

Functional Genomics and Immunologic Tools: The Impact of Viral and Host Genetic Variations on the Outcome of Zika Virus Infection

Zika virus (ZIKV) causes no-to-mild symptoms or severe neurological disorders. To investigate the importance of viral and host genetic variations in determining ZIKV infection outcomes, we created three full-length infectious cDNA clones as bacterial artificial chromosomes for each of three spatiotemporally distinct and genetically divergent ZIKVs: MR-766 (Uganda, 1947), P6-740 (Malaysia, 1966), and PRVABC-59 (Puerto Rico, 2015). Using the three molecularly cloned ZIKVs, together with 13 ZIKV region-specific polyclonal antibodies covering nearly the entire viral protein-coding region, we made three conceptual advances: (i) We created a comprehensive genome-wide portrait of ZIKV gene products and their related species, with several previously undescribed gene products identified in the case of all three molecularly cloned ZIKVs. (ii) We found that ZIKV has a broad cell tropism in vitro, being capable of establishing productive infection in 16 of 17 animal cell lines from 12 different species, although its growth kinetics varied depending on both the specific virus strain and host cell line. More importantly, we identified one ZIKV-non-susceptible bovine cell line that has a block in viral entry but fully supports the subsequent post-entry steps. (iii) We showed that in mice, the three molecularly cloned ZIKVs differ in their neuropathogenicity, depending on the particular combination of viral and host genetic backgrounds, as well as in the presence or absence of type I/II interferon signaling. Overall, our findings demonstrate the impact of viral and host genetic variations on the replication kinetics and neuropathogenicity of ZIKV and provide multiple avenues for developing and testing medical countermeasures against ZIKV

Solar thermoelectricity Via Advanced Latent Heat Storage

An aspect of the present disclosure is a system that includes a thermal valve having a first position and a second position, a heat transfer fluid, and an energy converter where, when in the first position, the thermal valve prevents the transfer of heat from the heat transfer fluid to the energy converter, and when in the second position, the thermal valve allows the transfer of heat from the heat transfer fluid to the energy converter, such that at least a portion of the heat transferred is converted to electricity by the energy converter

The influence of oblique-angle forced exercise in surgically destabilized stifle joints is synergistic with bone, but antagonistic with cartilage in an ovine model of osteoarthritis

Large animal models of osteoarthritis are a necessary testing ground for FDA approval of human medicine applications. Sheep models have advantages over other available large animals, but development and progression of osteoarthritis in sheep is exceedingly slow, which handicaps progress in development of potential treatments. We combined oblique angle forced exercise to increase stress on the stifle, with surgical destabilization to hasten the development of osteoarthritis in ewes. Methods for early detection of clinical signs included radiography, urine, and serum biomarker assays and gait analysis and ex vivo we used microcomputed tomography and macroscopic joint analysis. Our model was able to produce clinically detectable signs of osteoarthritis in a relatively short period (14 weeks). Changes in bone were highly correlated between microcomputed tomography and radiographic analysis and changes in cartilage correlated well between urinary glycosaminoglycan levels and serum aggrecanase analyses. Exercise improved the negative effects of destabilization in bone but exacerbated the negative effects of destabilization in cartilage. These observations suggest that we may need to consider treatments for bone and cartilage separately. These results represent an improved large animal model of osteoarthritis with rapid onset of disease and superior detection of bone and soft tissue changes