New tools for the investigations of Neuro-AIDS at a molecular level: The potential role of data-mining

Cognitive impairment represents the most significant and devastating neurological complication associated with HIV infection. Despite recent advances in our knowledge of the clinical features, pathogenesis, and molecular aspects of HIV-related dementia, current diagnostic strategies are associated with significant limitations. It has been suggested that the use of some biomarkers may assist researchers and clinicians in predicting the onset of the disease process and in evaluating the effects of new therapies. However, the large number of chemicals and metabolic pathways involved in the pathogenesis of neurodegeneration, warrants the development of novel approaches to integrate this huge amount of data. The contribution of theoretical disciplines, such as bioinformatics and data-mining, may be useful for testing new hypotheses in diagnosis and patient-centered treatment interventions.     

Hospital Door Handle Design and Their Contamination with Bacteria: A Real Life Observational Study. Are We Pulling against Closed Doors?

Objective

To determine whether microbial contamination of door handles in two busy intensive care units and one high dependency unit was related to their design, location, and usage.

Design

Observational study of the number of viable bacteria on existing door handles of different design at defined entry/exit points with simultaneous data collection of who used these doors and how often.

Setting

Two busy specialised intensive care units and one high dependency unit in a tertiary referral NHS neurological hospital.

Main outcome measures

Surface bacterial density on door handles with reference to design, location, and intensity of use.

Results

We found a significant correlation between the frequency of movements through a door and the degree to which it was contaminated (p = <0.01). We further found that the door''s location, design and mode of use all influenced contamination. When compared to push plate designs, pull handles revealed on average a five fold higher level of contamination; lever handles, however, displayed the highest levels of bacterial contamination when adjusted for frequency of use. We also observed differences in contamination levels at doors between clinical areas, particularly between the operating theatres and one of the ICUs.

Conclusions

Door handles in busy, “real life” high acuity clinical environments were variably contaminated with bacteria, and the number of bacteria found related to design, location, mode and frequency of operation. Largely ignored issues of handle and environmental design can support or undermine strategies designed to limit avoidable pathogen transmission, especially in locations designed to define “thresholds” and impose physical barriers to pathogen transmission between clinical areas. Developing a multidisciplinary approach beyond traditional boundaries for purposes of infection control may release hitherto unappreciated options and beneficial outcomes for the control of at least some hospital acquired infections.     

Interplay between Sumoylation and Phosphorylation for Protection against α-Synuclein Inclusions

Parkinson disease is associated with the progressive loss of dopaminergic neurons from the substantia nigra. The pathological hallmark of the disease is the accumulation of intracytoplasmic inclusions known as Lewy bodies that consist mainly of post-translationally modified forms of α-synuclein. Whereas phosphorylation is one of the major modifications of α-synuclein in Lewy bodies, sumoylation has recently been described. The interplay between α-synuclein phosphorylation and sumoylation is poorly understood. Here, we examined the interplay between these modifications as well as their impact on cell growth and inclusion formation in yeast. We found that α-synuclein is sumoylated in vivo at the same sites in yeast as in human cells. Impaired sumoylation resulted in reduced yeast growth combined with an increased number of cells with inclusions, suggesting that this modification plays a protective role. In addition, inhibition of sumoylation prevented autophagy-mediated aggregate clearance. A defect in α-synuclein sumoylation could be suppressed by serine 129 phosphorylation by the human G protein-coupled receptor kinase 5 (GRK5) in yeast. Phosphorylation reduced foci formation, alleviated yeast growth inhibition, and partially rescued autophagic α-synuclein degradation along with the promotion of proteasomal degradation, resulting in aggregate clearance in the absence of a small ubiquitin-like modifier. These findings suggest a complex interplay between sumoylation and phosphorylation in α-synuclein aggregate clearance, which may open new horizons for the development of therapeutic strategies for Parkinson disease.     

Aggregate Clearance of α-Synuclein in Saccharomyces cerevisiae Depends More on Autophagosome and Vacuole Function Than on the Proteasome

Parkinson disease is the second most common neurodegenerative disease. The molecular hallmark is the accumulation of proteinaceous inclusions termed Lewy bodies containing misfolded and aggregated α-synuclein. The molecular mechanism of clearance of α-synuclein aggregates was addressed using the bakers' yeast Saccharomyces cerevisiae as the model. Overexpression of wild type α-synuclein or the genetic variant A53T integrated into one genomic locus resulted in a gene copy-dependent manner in cytoplasmic proteinaceous inclusions reminiscent of the pathogenesis of the disease. In contrast, overexpression of the genetic variant A30P resulted only in transient aggregation, whereas the designer mutant A30P/A36P/A76P neither caused aggregation nor impaired yeast growth. The α-synuclein accumulation can be cleared after promoter shut-off by a combination of autophagy and vacuolar protein degradation. Whereas the proteasomal inhibitor MG-132 did not significantly inhibit aggregate clearance, treatment with phenylmethylsulfonyl fluoride, an inhibitor of vacuolar proteases, resulted in significant reduction in clearance. Consistently, a cim3-1 yeast mutant restricted in the 19 S proteasome regulatory subunit was unaffected in clearance, whereas an Δatg1 yeast mutant deficient in autophagy showed a delayed aggregate clearance response. A cim3-1Δatg1 double mutant was still able to clear aggregates, suggesting additional cellular mechanisms for α-synuclein clearance. Our data provide insight into the mechanisms yeast cells use for clearing different species of α-synuclein and demonstrate a higher contribution of the autophagy/vacuole than the proteasome system. This contributes to the understanding of how cells can cope with toxic and/or aggregated proteins and may ultimately enable the development of novel strategies for therapeutic intervention.     

Disseminating the best available evidence: New challenges in public reporting of health care

As a direct benefit of the Health Care Reform Act (2010), concerted effort has been deployed to define and characterize the process by which the best available evidence for diagnosis or treatment intervention prognosis can be obtained. The science of research synthesis in health care has established the systematic research protocol by which randomized clinical trials and other clinical studies must be reviewed and compared for the level and quality of the evidence presented, as well as the consensus of the best available evidence synthesized and shared. This process of systematic review yields a reliable and valid approach in comparing different interventions and strategies to prevent, diagnose, treat and monitor health conditions in terms of efficacy, and or of effectiveness. The resulting bioinformation outcome of comparative effectiveness and efficacy research review of the available clinical data is expressed as a consensus of the best available evidence, which finds its way in evidence-based clinical practice guidelines, standards of care and eventually, in policies: hence, the acronym CEERAP (comparative effectiveness and efficacy review and policy). The methodological and the procedural criteria that determine and regulate the public reporting dissemination of this sort of bioinformation, and the extent of benefit to the patient's health literacy, which have remained a bit more elusive to this date, are investigated and discussed in this paper.     

Benzenesulphonamide inhibitors of the cytolytic protein perforin

The pore-forming protein perforin is a key component of mammalian cell-mediated immunity and essential to the pathway that allows elimination of virus-infected and transformed cells. Perforin activity has also been implicated in certain auto-immune conditions and therapy-induced conditions such as allograft rejection and graft versus host disease. An inhibitor of perforin activity could be used as a highly specific immunosuppressive treatment for these conditions, with reduced side-effects compared to currently accepted therapies. Previously identified first-in-class inhibitors based on a 2-thioxoimidazolidin-4-one core show suboptimal physicochemical properties and toxicity toward the natural killer (NK) cells that secrete perforin in vivo. The current benzenesulphonamide-based series delivers a non-toxic bioisosteric replacement possessing improved solubility.