225 research outputs found
MicroRNAs of Gallid and Meleagrid herpesviruses show generally conserved genomic locations and are virus-specific
AbstractMany herpesviruses, including Marek's disease viruses (MDV1 and MDV2), encode microRNAs. In this study, we report microRNAs of two related herpesviruses, infectious laryngotracheitis virus (ILTV) and herpesvirus of turkeys (HVT), as well as additional MDV2 microRNAs. The genome locations, but not microRNA sequences, are conserved among all four of these avian herpesviruses. Most are clustered in the repeats flanking the unique long region (I/TRL), except in ILTV which lacks these repeats. Two abundant ILTV microRNAs are antisense to the immediate early gene ICP4. A homologue of host microRNA, gga-miR-221, was found among the HVT microRNAs. Additionally, a cluster of HVT microRNAs was found in a region containing two locally duplicated segments, resulting in paralogous HVT microRNAs with 96β100% identity. The prevalence of microRNAs in the genomic repeat regions as well as in local repeats suggests the importance of genetic plasticity in herpesviruses for microRNA evolution and preservation of function
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Applications of RESRAD family of computer codes to sites contaminated with radioactive residues.
The RESIL4D family of computer codes was developed to provide a scientifically defensible answer to the question ''How clean is clean?'' and to provide useful tools for evaluating human health risk at sites contaminated with radioactive residues. The RESRAD codes include (1) RESRAD for soil contaminated with radionuclides; (2) RESRAD-BUILD for buildings contaminated with radionuclides; (3) RESRAD-CHEM for soil contaminated with hazardous chemicals; (4) RESRAD-BASELINE for baseline risk assessment with measured media concentrations of both radionuclides and chemicals; (5) RESRAD-ECORISK for ecological risk assessment; (6) RESRAD-RECYCLE for recycle and reuse of radiologically contaminated metals and equipment; and (7) RESRAD-OFFSITE for off-site receptor radiological dose assessment. Four of these seven codes (RESRAD, RESRAD-BUILD, RESRAD-RECYCLE, and RESRAD-OFFSITE) also have uncertainty analysis capabilities that allow the user to input distributions of parameters. RESRAD has been widely used in the United States and abroad and approved by many federal and state agencies. Experience has shown that the RESRAD codes are useful tools for evaluating sites contaminated with radioactive residues. The use of RESRAD codes has resulted in significant savings in cleanup cost. Analysis of 19 site-specific uranium guidelines is discussed in the paper
Of Mice and Monkeys: Can Animal Models Be Utilized to Study Neurological Consequences of Pediatric HIV-1 Infection?
Pediatric human immunodeficiency virus (HIV-1) infection remains a global health crisis. Children are much more susceptible to HIV-1 neurological impairments than adults, which can be exacerbated by coinfections. Neurological characteristics of pediatric HIV-1 infection suggest dysfunction in the frontal cortex as well as the hippocampus; limited MRI data indicate global cerebral atrophy, and pathological data suggest accelerated neuronal apoptosis in the cortex. An obstacle to pediatric HIV-1 research is a human representative model system. Host-species specificity of HIV-1 limits the ability to model neurological consequences of pediatric HIV-1 infection in animals. Several models have been proposed including neonatal intracranial injections of HIV-1 viral proteins in rats and perinatal simian immunodeficiency virus (SIV) infection of infant macaques. Nonhuman primate models recapitulate the complexity of pediatric HIV-1, neuropathogenesis while rodent models are able to elucidate the role specific viral proteins exert on neurodevelopment. Nonhuman primate models show similar behavioral and neuropathological characteristics to pediatric HIV-1 infection and offer a stage to investigate early viral mechanisms, latency reservoirs, and therapeutic interventions. Here we review the relative strengths and limitations of pediatric HIV-1 model systems
Estimating risk of c. difficile transmission from pcr positive but cytotoxin negative cases
Abstract Background: The use of molecular methods to diagnose Clostridium difficile infection (CDI) has improved diagnostic yield compared to conventional methods. However, PCR testing can detect colonization and has introduced several practical challenges pertaining to need for treatment and isolation of cases
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User's manual for RESRAD version 6.
This manual provides information on the design and application of the RESidual RADioactivity (RESRAD) code. It describes the basic models and parameters used in the RESRAD code to calculate doses and risks from residual radioactive materials and the procedures for applying these models to calculate operational guidelines for soil contamination. RESRAD has undergone many improvements to make it more realistic in terms of the models used in the code and the parameters used as defaults. Version 6 contains a total of 145 radionuclides (92 principal and 53 associated radionuclides), and the cutoff half-life for associated radionuclides has been reduced to 1 month. Other major improvements to the RESRAD code include its ability to run uncertainty analyses, additional options for graphical and text output, a better dose conversion factor editor, updated databases, a better groundwater transport model for long decay chains, an external ground radiation pathway model, an inhalation area factor model, time-integration of dose and risk, and a better graphical user interface. In addition, RESRAD has been benchmarked against other codes in the environmental assessment and site cleanup arena, and RESRAD models have been verified and validated
Cathepsin-B and cathepsin-L expression levels do not correlate with sensitivity of tumour cells to TNF-Ξ±-mediated apoptosis
Contextualising social capital in online brand communities
Online brand communities (OBC) are growing in number and becoming an increasingly important interface where marketers can effectively facilitate the relationship between their brand and consumers. A qualitative study using a four-month netnography over three OBCs followed by focus groups with OBC members explored the dynamics of social capital in these communities. Findings indicate that social capital is an important driver in the success of OBCs, and all the elements of social capital including a shared language, shared vision, social trust and reciprocity are evident. Moreover, results from this study indicate that these elements are crucial in developing the network ties that are integral to building loyalty and brand equity
Participation of intracellular cysteine proteinases, in particular cathepsin B, in degradation of collagen in periosteal tissue explants
The involvement of cysteine proteinases in the degradation of soft connective tissue collagen was studied in cultured periosteal explants. Using cysteine proteinase inhibitors that were active intracellularly or extracellularly (Ep453 and Ep475, respectively), it was shown that over-all collagen degradation, as measured by the release of hydroxyproline, decreased significantly on inhibition of the intracellular pool of cysteine proteinases by Ep453. This inhibitor also induced an accumulation of intracellular fibrillar collagen in fibroblasts, indicating a decreased degradation of phagocytosed collagen. The extracellular inhibitor, Ep475, had minor or no effects. Histochemical analysis using a substrate for the cysteine proteinases cathepsins B and L revealed a high level of enzyme activity, which was completely blocked in explants preincubated with a selective intracellular inhibitor of cathepsin B, Ca074-Me. Moreover, the cathepsin B inhibitor strongly affected collagen degradation, decreasing the release of hydroxyproline and increasing the accumulation of phagocytosed collagen. These effects were comparable or slightly stronger than those found with the general intracellular inhibitor (Ep453). Taken together, these data strongly suggest that intracellular cysteine proteinases, in particular cathepsin B, play an important role in the digestion of soft connective tissue collage
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