In vitro amplification and detection of variant Creutzfeldt-Jakob disease PrPSc

Variant Creutzfeldt-Jakob disease (vCJD) poses a serious risk of secondary transmission and the need to detect infectivity in asymptomatic individuals is therefore of major importance. Following infection, it is assumed that minute amounts of disease-associated prion protein (PrP(Sc)) replicate by conversion of the host cellular prion protein (PrP(C)). Therefore, methods of rapidly reproducing this conversion process in vitro would be valuable tools in the development of such tests. We show that one such technique, protein misfolding cyclic amplification (PMCA), can amplify vCJD PrP(Sc) from human brain tissue, and that the degree of amplification is dependent upon the substrate PRNP codon 129 polymorphism. Both human platelets and transgenic mouse brain are shown to be suitable alternative substrate sources, and amplified PrP(Sc) can be detected using a conformation-dependent immunoassay (CDI), allowing the detection of putative proteinase K sensitive forms of PrP(Sc).     

Memory loss in old rats is associated with brain mitochondrial decay and RNA/DNA oxidation: partial reversal by feeding acetyl-L-carnitine and/or R-alpha -lipoic acid

Accumulation of oxidative damage to mitochondria, protein, and nucleic acid in the brain may lead to neuronal and cognitive dysfunction. The effects on cognitive function, brain mitochondrial structure, and biomarkers of oxidative damage were studied after feeding old rats two mitochondrial metabolites, acetyl-l-carnitine (ALCAR) [0.5% or 0.2% (wt/vol) in drinking water], and/or R-alpha-lipoic acid (LA) [0.2% or 0.1% (wt/wt) in diet]. Spatial memory was assessed by using the Morris water maze; temporal memory was tested by using the peak procedure (a time-discrimination procedure). Dietary supplementation with ALCAR and/or LA improved memory, the combination being the most effective for two different tests of spatial memory (P < 0.05; P < 0.01) and for temporal memory (P < 0.05). Immunohistochemical analysis showed that oxidative damage to nucleic acids (8-hydroxyguanosine and 8-hydroxy-2'-deoxyguanosine) increased with age in the hippocampus, a region important for memory. Oxidative damage to nucleic acids occurred predominantly in RNA. Dietary administration of ALCAR and/or LA significantly reduced the extent of oxidized RNA, the combination being the most effective. Electron microscopic studies in the hippocampus showed that ALCAR and/or LA reversed age-associated mitochondrial structural decay. These results suggest that feeding ALCAR and LA to old rats improves performance on memory tasks by lowering oxidative damage and improving mitochondrial function.     

Determination of anti-inflammatory activities of standardised preparations of plant- and mushroom-based foods

Purpose

Chronic inflammatory processes contribute to the pathogenesis of many age-related diseases. In search of anti-inflammatory foods, we have systematically screened a variety of common dietary plants and mushrooms for their anti-inflammatory activity.

Methods

A selection of 115 samples was prepared by a generic food-compatible processing method involving heating. These products were tested for their anti-inflammatory activity in murine N11 microglia and RAW 264.7 macrophages, using nitric oxide (NO) and tumour necrosis factor-α (TNF-α) as pro-inflammatory readouts.

Results

Ten food samples including lime zest, English breakfast tea, honey-brown mushroom, button mushroom, oyster mushroom, cinnamon and cloves inhibited NO production in N11 microglia, with IC₅₀ values below 0.5 mg/ml. The most active samples were onion, oregano and red sweet potato, exhibiting IC₅₀ values below 0.1 mg/ml. When these ten food preparations were retested in RAW 264.7 macrophages, they all inhibited NO production similar to the results obtained in N11 microglia. In addition, English breakfast tea leaves, oyster mushroom, onion, cinnamon and button mushroom preparations suppressed TNF-α production, exhibiting IC₅₀ values below 0.5 mg/ml in RAW 264.7 macrophages.

Conclusion

In summary, anti-inflammatory activity in these food samples survived ‘cooking’. Provided that individual bioavailability allows active compounds to reach therapeutic levels in target tissues, these foods may be useful in limiting inflammation in a variety of age-related inflammatory diseases. Furthermore, these foods could be a source for the discovery of novel anti-inflammatory drugs.     

Systematic analysis of funding awarded for norovirus research to institutions in the United Kingdom, 1997–2010

Objectives

Norovirus infections pose great economic and disease burden to health systems around the world. This study quantifies the investments in norovirus research awarded to UK institutions over a 14-year time period.

Design

A systematic analysis of public and philanthropic infectious disease research investments awarded to UK institutions between 1997 and 2010.

Participants

None

Setting

UK institutions carrying out infectious disease research.

Main outcome measures

Total funding for infectious disease research, total funding for norovirus research, position of norovirus research along the R&D value chain.

Results

The total dataset consisted of 6165 studies with sum funding of £2.6 billion. Twelve norovirus studies were identified with a total funding of £5.1 million, 0.2% of the total dataset. Of these, eight were categorized as pre-clinical, three as intervention studies and one as implementation research. Median funding was £200,620.

Conclusions

Research funding for norovirus infections in the UK appears to be unacceptably low, given the burden of disease and disability produced by these infections. There is a clear need for new research initiatives along the R&D value chain: from pre-clinical through to implementation research, including trials to assess cost-effectiveness of infection control policies as well as clinical, public health and environmental interventions in hospitals, congregate settings and in the community.