Effects of an In-Frame Deletion of the 6k Gene Locus from the Genome of Ross River Virus.

UNLABELLED: The alphaviral6kgene region encodes the two structural proteins 6K protein and, due to a ribosomal frameshift event, the transframe protein (TF). Here, we characterized the role of the6kproteins in the arthritogenic alphavirus Ross River virus (RRV) in infected cells and in mice, using a novel6kin-frame deletion mutant. Comprehensive microscopic analysis revealed that the6kproteins were predominantly localized at the endoplasmic reticulum of RRV-infected cells. RRV virions that lack the6kproteins 6K and TF [RRV-(Δ6K)] were more vulnerable to changes in pH, and the corresponding virus had increased sensitivity to a higher temperature. While the6kdeletion did not reduce RRV particle production in BHK-21 cells, it affected virion release from the host cell. Subsequentin vivostudies demonstrated that RRV-(Δ6K) caused a milder disease than wild-type virus, with viral titers being reduced in infected mice. Immunization of mice with RRV-(Δ6K) resulted in a reduced viral load and accelerated viral elimination upon secondary infection with wild-type RRV or another alphavirus, chikungunya virus (CHIKV). Our results show that the6kproteins may contribute to alphaviral disease manifestations and suggest that manipulation of the6kgene may be a potential strategy to facilitate viral vaccine development. IMPORTANCE: Arthritogenic alphaviruses, such as chikungunya virus (CHIKV) and Ross River virus (RRV), cause epidemics of debilitating rheumatic disease in areas where they are endemic and can emerge in new regions worldwide. RRV is of considerable medical significance in Australia, where it is the leading cause of arboviral disease. The mechanisms by which alphaviruses persist and cause disease in the host are ill defined. This paper describes the phenotypic properties of an RRV6kdeletion mutant. The absence of the6kgene reduced virion release from infected cells and also reduced the severity of disease and viral titers in infected mice. Immunization with the mutant virus protected mice against viremia not only upon exposure to RRV but also upon challenge with CHIKV. These findings could lead to the development of safer and more immunogenic alphavirus vectors for vaccine delivery.

Power of Peer-Assisted Learning: An Interdisciplinary Mobility Laboratory Experience.

BACKGROUND: The benefits of early patient mobility in the hospital environment has been well established. This article highlights an interactive peer-assisted learning (PAL) mobility laboratory. Physical therapy (PT) students taught patient mobility skills to nursing students, with the goal of enhancing mobility knowledge and improved understanding of the two disciplines' roles and responsibilities. METHOD: The students were divided into 10 groups, with six nursing and three PT students in each group; each group rotated through the 10 mobility stations every 20 minutes. After completing all stations, the nursing students reviewed a case scenario requiring application of the recently learned knowledge and skills. RESULTS: Analysis revealed that the nursing students demonstrated significant improvement in overall knowledge of safe patient mobility, as well as improved confidence in the instruction of safe patient mobility. CONCLUSION: Both groups reported that the PAL strategy was successful in achieving the intended goals of improved interprofessional understanding.

Role of envelope N-linked glycosylation in Ross River virus virulence and transmission.

With an expanding geographical range and no specific treatments, human arthritogenic alphaviral disease poses a significant problem worldwide. Previous in vitro work with Ross River virus (RRV) demonstrated that alphaviral N-linked glycosylation contributes to type I IFN (IFN-αß) induction in myeloid dendritic cells. This study further evaluated the role of alphaviral N-linked glycans in vivo, assessing the effect of glycosylation on pathogenesis in a mouse model of RRV-induced disease and on viral infection and dissemination in a common mosquito vector, Aedes vigilax. A viral mutant lacking the E1-141 glycosylation site was attenuated for virus-induced disease, with reduced myositis and higher levels of IFN-γ induction at peak disease contributing to improved viral clearance, suggesting that glycosylation of the E1 glycoprotein plays a major role in the pathogenesis of RRV. Interestingly, RRV lacking E2-200 glycan had significantly reduced replication in the mosquito vector A. vigilax, whereas loss of either of the E1 or E2-262 glycans had little effect on the competence of the mosquito vector. Overall, these results indicate that glycosylation of the E1 and E2 glycoproteins of RRV provides important determinants of viral virulence and immunopathology in the mammalian host and replication in the mosquito vector.

Dual proinflammatory and antiviral properties of pulmonary eosinophils in respiratory syncytial virus vaccine-enhanced disease.

UNLABELLED: Human respiratory syncytial virus (RSV) is a major cause of morbidity and severe lower respiratory tract disease in the elderly and very young, with some infants developing bronchiolitis, recurrent wheezing, and asthma following infection. Previous studies in humans and animal models have shown that vaccination with formalin-inactivated RSV (FI-RSV) leads to prominent airway eosinophilic inflammation following RSV challenge; however, the roles of pulmonary eosinophilia in the antiviral response and in disease pathogenesis are inadequately understood. In vivo studies in mice with eotaxin and/or interleukin 5 (IL-5) deficiency showed that FI-RSV vaccination did not lead to enhanced pulmonary disease, where following challenge there were reduced pulmonary eosinophilia, inflammation, Th2-type cytokine responses, and altered chemokine (TARC and CCL17) responses. In contrast to wild-type mice, RSV was recovered at high titers from the lungs of eotaxin- and/or IL-5-deficient mice. Adoptive transfer of eosinophils to FI-RSV-immunized eotaxin- and IL-5-deficient (double-deficient) mice challenged with RSV was associated with potent viral clearance that was mediated at least partly through nitric oxide. These studies show that pulmonary eosinophilia has dual outcomes: one linked to RSV-induced airway inflammation and pulmonary pathology and one with innate features that contribute to a reduction in the viral load. IMPORTANCE: This study is critical to understanding the mechanisms attributable to RSV vaccine-enhanced disease. This study addresses the hypothesis that IL-5 and eotaxin are critical in pulmonary eosinophil response related to FI-RSV vaccine-enhanced disease. The findings suggest that in addition to mediating tissue pathology, eosinophils within a Th2 environment also have antiviral activity.

Use of benzodiazepines as anxiolytics in neonates: are we there yet?

Few controlled trials exist to demonstrate the efficacy and the risks of pharmacologic agents used in treating pediatric, and more specifically neonatal patients. It is not different for the central nervous system altering class of drugs, benzodiazepines (BZDs). Little information is known about the long-term effects of BZDs use in neonates as anxiolytics and sedatives causing trepidation with their use in the clinical setting. Insufficient data related to the use of BZDs result in a lack of clear recommendations to guide caregivers at the bedside on the safest administration patterns to avoid long-term adverse effects. However, caring for ill neonates, in particular surgical patients and infants requiring prolonged hospitalizations, necessitates the use of these agents. A literature search within the electronic database, PubMed, of English language, full-text articles published between 2007 and 2012 was undertaken to determine the state of the science regarding the use of BZDs in neonates. These medications cause unwanted effects in neonates with immature hepatic function (primary site of metabolism) and during a developmental period of tremendous neuroplasticity. It benefits caregivers to recognize the need for improved monitoring of stress experienced by infants in the NICU and understand the impact of prolonged agitation and subacute pain on infant development.

Dengue virus therapeutic intervention strategies based on viral, vector and host factors involved in disease pathogenesis.

Dengue virus (DV) is the most widespread arbovirus, being endemic in over 100 countries, and is estimated to cause 50 million infections annually. Viral factors, such as the genetic composition of the virus strain can play a role in determining the virus virulence and subsequent clinical disease severity. Virus vector competence plays an integral role in virus transmission and is a critical factor in determining the severity and impact of DV outbreaks. Host genetic variations in immune-related genes, including the human leukocyte antigen, have also been shown to correlate with clinical disease and thus may play a role in regulating disease severity. The host's immune system, however, appears to be the primary factor in DV pathogenesis with the delicate interplay of innate and acquired immunity playing a crucial role. Although current research of DV pathogenesis has been limited by the lack of an appropriate animal model, the development of DV therapeutics has been a primary focus of research groups around the world. In the past decade advances in both the development of vaccines and anti-virals have increased in dramatically. This review summarises the current understanding of viral, vector and host factors which contribute to dengue virus pathogenesis and how this knowledge is critically important in the development of pharmaceutical interventions.

The relationships among stress, coping, social support, and weight class in premenopausal African American women at risk for coronary heart disease.

The purpose of this study was to determine the nature of the relationships among stress, coping, social support, and weight class in premenopausal African American women as risk factors for coronary heart disease. Overweight and obesity are significant problems for African American women who are at an increased risk of weight-related diseases, such as diabetes, hypertension, cardiovascular disease, and cancer. Of these women, those who are premenopausal have a significantly higher coronary heart disease mortality rate than their white counterparts. There are gaps in current knowledge concerning the role that stress and other psychosocial factors play in weight control of premenopausal African American women. Data were obtained from 178 women with eligible data sets from a larger study of 236 subjects (Genetic Predictors of Coronary Heart Disease in Premenopausal African American Women). The measures for stress, coping, and social support included the Perceived Stress Scale, the Norbeck Social Support Questionnaire, and the Jalowiec Coping Scale. The weight class of the women was determined as: normal weight-body mass index (BMI) of 18.5-24.9 kg/m, overweight-BMI of 25-29.9 kg/m, or obese-BMI > or = 30 kg/m. Statistical analysis conducted included Spearman's rho, Chi-square, and regression analysis. Confrontive coping was shown to be used more often to a "high" degree in normal-weight African American women than in overweight and obese African American women (chi = 24.024; P = .0001). Confrontive coping was the only independent predictor of weight class in a regression model that included perceived stress, life events, social support, and optimistic, self-reliant, and evasive coping strategies. Therefore, African American women who use confrontive coping to a high degree were more likely to confront problems, such as weight control issues, than those who use this coping strategy to a low or medium degree.