EBNA2 Binds to Genomic Intervals Associated with Multiple Sclerosis and Overlaps with Vitamin D Receptor Occupancy

Epstein-Barr virus (EBV) is a non-heritable factor that associates with multiple sclerosis (MS). However its causal relationship with the disease is still unclear. The virus establishes a complex co-existence with the host that includes regulatory influences on gene expression. Hence, if EBV contributes to the pathogenesis of MS it may do so by interacting with disease predisposing genes. To verify this hypothesis we evaluated EBV nuclear antigen 2 (EBNA2, a protein that recent works by our and other groups have implicated in disease development) binding inside MS associated genomic intervals. We found that EBNA2 binding occurs within MS susceptibility sites more than expected by chance (factor of observed vs expected overlap [O/E] = 5.392-fold, p < 2.0e-05). This remains significant after controlling for multiple genomic confounders. We then asked whether this observation is significant per se or should also be viewed in the context of other disease relevant gene-environment interactions, such as those attributable to vitamin D. We therefore verified the overlap between EBNA2 genomic occupancy and vitamin D receptor (VDR) binding sites. EBNA2 shows a striking overlap with VDR binding sites (O/E = 96.16-fold, p < 2.0e-05), even after controlling for the chromatin accessibility state of shared regions (p <0.001). Furthermore, MS susceptibility regions are preferentially targeted by both EBNA2 and VDR than by EBNA2 alone (enrichment difference = 1.722-fold, p = 0.0267). Taken together, these findings demonstrate that EBV participates in the gene-environment interactions that predispose to MS.     

Cost Evaluation of Reproductive and Primary Health Care Mobile Service Delivery for Women in Two Rural Districts in South Africa

Background

Cervical cancer screening is a critical health service that is often unavailable to women in under-resourced settings. In order to expand access to this and other reproductive and primary health care services, a South African non-governmental organization established a van-based mobile clinic in two rural districts in South Africa. To inform policy and budgeting, we conducted a cost evaluation of this service delivery model.

Methods

The evaluation was retrospective (October 2012–September 2013 for one district and April–September 2013 for the second district) and conducted from a provider cost perspective. Services evaluated included cervical cancer screening, HIV counselling and testing, syndromic management of sexually transmitted infections (STIs), breast exams, provision of condoms, contraceptives, and general health education. Fixed costs, including vehicle purchase and conversion, equipment, operating costs and mobile clinic staffing, were collected from program records and public sector pricing information. The number of women accessing different services was multiplied by ingredients-based variable costs, reflecting the consumables required. All costs are reported in 2013 USD.

Results

Fixed costs accounted for most of the total annual costs of the mobile clinics (85% and 94% for the two districts); the largest contributor to annual fixed costs was staff salaries. Average costs per patient were driven by the total number of patients seen, at $46.09 and $76.03 for the two districts. Variable costs for Pap smears were higher than for other services provided, and some services, such as breast exams and STI and tuberculosis symptoms screening, had no marginal cost.

Conclusions

Staffing costs are the largest component of providing mobile health services to rural communities. Yet, in remote areas where patient volumes do not exceed nursing staff capacity, incorporating multiple services within a cervical cancer screening program is an approach to potentially expand access to health care without added costs.     

Oseltamivir Prophylaxis Reduces Inflammation and Facilitates Establishment of Cross-Strain Protective T Cell Memory to Influenza Viruses

CD8⁺ T cells directed against conserved viral regions elicit broad immunity against distinct influenza viruses, promote rapid virus elimination and enhanced host recovery. The influenza neuraminidase inhibitor, oseltamivir, is prescribed for therapy and prophylaxis, although it remains unclear how the drug impacts disease severity and establishment of effector and memory CD8⁺ T cell immunity. We dissected the effects of oseltamivir on viral replication, inflammation, acute CD8⁺ T cell responses and the establishment of immunological CD8⁺ T cell memory. In mice, ferrets and humans, the effect of osteltamivir on viral titre was relatively modest. However, prophylactic oseltamivir treatment in mice markedly reduced morbidity, innate responses, inflammation and, ultimately, the magnitude of effector CD8⁺ T cell responses. Importantly, functional memory CD8⁺ T cells established during the drug-reduced effector phase were capable of mounting robust recall responses. Moreover, influenza-specific memory CD4⁺ T cells could be also recalled after the secondary challenge, while the antibody levels were unaffected. This provides evidence that long-term memory T cells can be generated during an oseltamivir-interrupted infection. The anti-inflammatory effect of oseltamivir was verified in H1N1-infected patients. Thus, in the case of an unpredicted influenza pandemic, while prophylactic oseltamivir treatment can reduce disease severity, the capacity to generate memory CD8⁺ T cells specific for the newly emerged virus is uncompromised. This could prove especially important for any new influenza pandemic which often occurs in separate waves.     

Staphylococcus aureus-derived staphopain B, a potent cysteine protease activator of plasma chemerin

Chemerin is an attractant for cells that express the serpentine receptor CMKLR1, which include immature plasmacytoid dendritic cells (pDC) and macrophages. Chemerin circulates in the blood where it exhibits low biological activity, but upon proteolytic cleavage of its C terminus, it is converted to a potent chemoattractant. Enzymes that contribute to this conversion include host serine proteases of the coagulation, fibrinolytic, and inflammatory cascades, and it has been postulated that recruitment of pDC and macrophages by chemerin may serve to balance local tissue immune and inflammatory responses. In this work, we describe a potent, pathogen-derived proteolytic activity capable of chemerin activation. This activity is mediated by staphopain B (SspB), a cysteine protease secreted by Staphylococcus aureus. Chemerin activation is triggered by growth medium of clinical isolates of SspB-positive S. aureus, but not by that of a SspB(null) mutant. C-terminal processing by SspB generates a chemerin isoform identical with the active endogenous attractant isolated from human ascites fluid. Interestingly, SspB is a potent trigger of chemerin even in the presence of plasma inhibitors. SspB may help direct the recruitment of specialized host cells, including immunoregulatory pDC and/or macrophages, contributing to the ability of S. aureus to elicit and maintain a chronic inflammatory state.     

Fruit type,life form and origin determine the success of woody plant invaders in an urban landscape

The spread of alien plant species is a critical ecological event worldwide, but the forces that control this spread are not well documented. Alien plant species are well known to disrupt ecological services of native ecosystems, change the composition of native habitats, and often lead to the extirpation of native flora and fauna. Here, we report on life history patterns of plant species with rapidly spreading and declining ranges in North America’s major urban region. We tested for differences in life history traits between the 466 native and alien woody flora of the New York metropolitan area. We also examined the relationship between life history traits and change in distribution in the New York metropolitan area between 1900 and 2000. Native and alien species of the New York metropolitan area differ with respect to pollination vector and breeding system. However, pollination vector and breeding system are not associated with success, defined here as increasing range spread in the urban environment; instead, fruit type (dispersal), life form and origin are important determinants of success. Alien species that are deciduous trees, shrubs or vines with fleshy fruit are the most successful in increasing their distribution in this urban landscape. Newly introduced species with these characteristics are expected to have a better chance at establishing in similar urban landscapes and should be targets for intensive management. The ability to predict which alien species will become invasive is also a valuable tool for the prevention of invasions by newly introduced plant species.     

Exploiting differences in caspase-2 and -3 S₂ subsites for selectivity: structure-based design, solid-phase synthesis and in vitro activity of novel substrate-based caspase-2 inhibitors

Several caspases have been implicated in the pathogenesis of Huntington's disease (HD); however, existing caspase inhibitors lack the selectivity required to investigate the specific involvement of individual caspases in the neuronal cell death associated with HD. In order to explore the potential role played by caspase-2, the potent but non-selective canonical Ac-VDVAD-CHO caspase-2 inhibitor 1 was rationally modified at the P(2) residue in an attempt to decrease its activity against caspase-3. With the aid of structural information on the caspase-2, and -3 active sites and molecular modeling, a 3-(S)-substituted-l-proline along with four additional scaffold variants were selected as P(2) elements for their predicted ability to clash sterically with a residue of the caspase-3 S(2) pocket. These elements were then incorporated by solid-phase synthesis into pentapeptide aldehydes 33a-v. Proline-based compound 33h bearing a bulky 3-(S)-substituent displayed advantageous characteristics in biochemical and cellular assays with 20- to 60-fold increased selectivity for caspase-2 and ～200-fold decreased caspase-3 potency compared to the reference inhibitor 1. Further optimization of this prototype compound may lead to the discovery of valuable pharmacological tools for the study of caspase-2 mediated cell death, particularly as it relates to HD.     

Sero-prevalence and incidence of A/H1N1 2009 influenza infection in Scotland in winter 2009-2010

Background

Sero-prevalence is a valuable indicator of prevalence and incidence of A/H1N1 2009 infection. However, raw sero-prevalence data must be corrected for background levels of cross-reactivity (i.e. imperfect test specificity) and the effects of immunisation programmes.

Methods and Findings

We obtained serum samples from a representative sample of 1563 adults resident in Scotland between late October 2009 and April 2010. Based on a microneutralisation assay, we estimate that 44% (95% confidence intervals (CIs): 40–47%) of the adult population of Scotland were sero-positive for A/H1N1 2009 influenza by 1 March 2010. Correcting for background cross-reactivity and for recorded vaccination rates by time and age group, we estimated that 34% (27–42%) were naturally infected with A/H1N1 2009 by 1 March 2010. The central estimate increases to >40% if we allow for imperfect test sensitivity. Over half of these infections are estimated to have occurred during the study period and the incidence of infection in late October 2009 was estimated at 4.3 new infections per 1000 people per day (1.2 to 7.2), falling close to zero by April 2010. The central estimate increases to over 5.0 per 1000 if we allow for imperfect test specificity. The rate of infection was higher for younger adults than older adults. Raw sero-prevalences were significantly higher in more deprived areas (likelihood ratio trend statistic = 4.92,1 df, P = 0.03) but there was no evidence of any difference in vaccination rates.

Conclusions

We estimate that almost half the adult population of Scotland were sero-positive for A/H1N1 2009 influenza by early 2010 and that the majority of these individuals (except in the oldest age classes) sero-converted as a result of natural infection with A/H1N1 2009. Public health planning should consider the possibility of higher rates of infection with A/H1N1 2009 influenza in more deprived areas.     

Candida albicans biofilm formation on soft denture liners and efficacy of cleaning protocols

doi: 10.1111/j.1741‐2358.2011.00485.x
Candida albicans biofilm formation on soft denture liners and efficacy of cleaning protocols Objective: The aim of this study was to investigate Candida albicans biofilm formation on denture liners and to analyse the efficacy of cleaning protocols. Material and methods: Specimens were prepared from four silicone‐based soft denture liners. After artificial ageing and surface free energy determination, specimens were incubated with saliva (2 h) and Candida albicans ATCC 10231 for either short‐ (2.5 h) or long‐term (24 h) biofilm formation. Adherent cells were determined either after incubation of specimens with Candida albicans or after treatment with different denture cleaning protocols. Statistical analysis was performed using one‐way anova and the Games–Howell test (α = 0.05). Results: For both short‐ and long‐term biofilm formation, similar amounts of Candida albicans cells were found on the surface of the different liners (p = 0.295 and 0.178, respectively). For both short‐ and long‐term biofilm formation, the highest cleaning efficacy was observed for sodium hypochlorite (NaOCl; p < 0.01). The efficacy of the chemical denture cleaner in removing long‐term Candida albicans biofilms was significantly lower than the efficacy of removal by brushing (p < 0.001). Conclusion: Different silicone‐based soft denture liners yield similar Candida albicans biofilm formation on their surface. The highest efficacy for the removal of Candida albicans biofilms was identified for NaOCl. Chemical denture cleaners appear to have rather low efficacy to remove mature Candida albicans biofilms.