The selection of a hydrophobic 7-phenylbutyl-7-deazaadenine-modified DNA aptamer with high binding affinity for the Heat Shock Protein 70.

Nucleic acids aptamers often fail to efficiently target some proteins because of the hydrophilic character of the natural nucleotides. Here we present hydrophobic 7-phenylbutyl-7-deaadenine-modified DNA aptamers against the Heat Shock Protein 70 that were selected via PEX and magnetic bead-based SELEX. After 9 rounds of selection, the pool was sequenced and a number of candidates were identified. Following initial screening, two modified aptamers were chemically synthesised in-house and their binding affinity analysed by two methods, bio-layer interferometry and fluorescent-plate-based binding assay. The binding affinities of the modified aptamers were compared with that of their natural counterparts. The resulting modified aptamers bound with higher affinity (low nanomolar range) to the Hsp70 than their natural sequence (>5 µM) and hence have potential for applications and further development towards Hsp70 diagnostics or even therapeutics.

Bacterial Cellulose Spheres that Encapsulate Solid Materials.

Bacterial cellulose (BC) spheres have been increasingly researched since the popularization of BC as a novel material. This protocol presents an affordable and simple method for BC sphere production. In addition to producing these spheres, an encapsulation method for solid particles has also been identified. To produce BC spheres, water, black tea, sugar, vinegar, and bacterial culture are combined in a baffled flask and the contents are agitated. After determining the proper culture conditions for BC sphere formation, their ability to encapsulate solid particles was tested using biochar, polymer beads, and mine waste. Spheres were characterized using ImageJ software and thermal gravimetric analysis (TGA). Results indicate that spheres with 7.5 mm diameters can be made in 7 days. Adding various particles increases the average size range of the BC capsules. The spheres encapsulated 10 - 20% of their dry mass. This method shows low-cost sphere production and encapsulation that is possible with easily obtainable materials. BC spheres may be used in the future as a contaminant removal aid, controlled release fertilizer coating, or soil amendment.

Mycotoxin contamination of sorghum and its contribution to human dietary exposure in four sub-Saharan countries.

This research aimed at evaluating the safety, and the type, level and prevalence of mycotoxins in grain sorghum of four sub-Saharan African (SSA) countries (Burkina Faso, Ethiopia, Mali and Sudan). A multi-analyte LC-MS/MS method for quantification of 23 mycotoxins (nivalenol, deoxynivalenol, fusarenon X, neosolaniol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, diacetoxyscirpenol, roquefortine C, HT-2 toxin, alternariol, T-2 toxin, FB1, FB2, FB3, zearalenone, aflatoxin G1, aflatoxin G2, aflatoxin B1, aflatoxin B2, sterigmatocystin, OTA, altenuene, alternariol monomethylether) was applied to different sorghum matrices. Of the 1533 analysed samples, 33% were contaminated with at least one of the following mycotoxins: aflatoxins, fumonisins, sterigmatocystin, Alternaria toxins, OTA and zearalenone. Country of origin, colour, source and collection period of sorghum samples significantly influenced the type, level and prevalence of mycotoxins. Sterigmatocystin (15%), fumonisins (17%) and aflatoxins (13%) were the most prevalent. FB1 (274 ± 585 µg/kg) had the highest mean concentration followed by FB2 (214 ± 308 µg/kg) while diacetoxyscirpenol (8.12 ± 19.2 µg/kg) and HT-2 (11.9 ± 0.00 µg/kg) had the lowest concentrations. Neosolaniol, fusarenon-X, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, T-2 toxin, nivalenol and roquefortine C were not detected in any of the samples. Sudan had the lowest prevalence and mean concentration of all mycotoxins. Pink sorghum had the highest concentrations of fumonisins and aflatoxins. Mycotoxins from Aspergillus spp. and Alternaria spp. are the mycotoxins of concern in SSA grain sorghum with regard to prevalence, concentration and possible health risk from exposure. Based on the performed risk characterisation, daily consumption of sorghum containing aflatoxins, alternariol, alternariol monomethyl ether, sterigmatocystin and OTA could result in exceeding the established health-based guidance values for these toxins.

The development of a real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay using TaqMan technology for the pan detection of bluetongue virus (BTV).

Bluetongue virus (BTV) is an infectious, non-contagious viral disease of domestic and wild ruminants that is transmitted by adult females of certain Culicoides species. Since 2006, several serotypes including BTV-1, 2, 4, 6, 8, 9 and 16, have spread from the Mediterranean basin into Northern Europe for the first time. BTV-8 in particular, caused a major epidemic in northern Europe. As a result, it is evident that most European countries are at risk of BTV infection. The objective of this study was to develop and validate a real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) assay based on TaqMan technology for the detection of representative strains of all BTV serotypes. Primers and probes were based on genome segment 10 of the virus, the NS3 gene. The assay was tested for sensitivity, and specificity. The analytical sensitivity of the rRT-PCR assay was 200 copies of RNA per reaction. The assay did not amplify the closely related orbivirus epizootic hemorrhagic disease virus (EHDV) but successfully detected all BTV reference strains including clinical samples from animals experimentally infected with BTV-8. This real time RT-PCR assay offers a sensitive, specific and rapid alternative assay for the pan detection of BTV that could be used as part of a panel of diagnostic assays for the detection of all serotypes of BTV.

The development of an accelerated reverse-transcription loop mediated isothermal amplification for the serotype specific detection of bluetongue virus 8 in clinical samples.

In 2006 bluetongue virus serotype 8 (BTV 8) was identified for the first time in the Netherlands causing a major epidemic in sheep and cattle that quickly spread to neighbouring Belgium, Germany and beyond to France and the UK. This resulted in severe animal health and welfare problems as well as substantial economic losses to the agrifood industries of these countries. Given that the early diagnosis of BTV infection 'in-the-field' is extremely useful to its subsequent management and control, this study was established to design a novel, sensitive and rapid nucleic acid diagnostic test for the serotype-specific detection of BTV 8, which could be used without the use of advanced laboratory support and equipment. Primers for the detection of BTV 8 were based on genome segment 2 of the virus, the VP2 gene. The assay was assessed using a full panel of BTV reference strains and clinical samples. Positive amplification was observed using a fluorescent detection reagent. The sensitivity of the RT-LAMP assay was 102 copies of RNA. The assay did not amplify the closely related orbivirus EHDV. This novel RT-LAMP offers a sensitive, specific and rapid method of detecting BTV 8. The approach is inexpensive and easy to use and could potentially be used in a 'pen-side' setting 'in the field' or by smaller less well-equipped laboratories in developing countries.

Integrated approaches to address the social determinants of health for reducing health inequity.

The social and physical environments have long since been recognized as important determinants of health. People in urban settings are exposed to a variety of health hazards that are interconnected with their health effects. The Millennium Development Goals (MDGs) have underlined the multidimensional nature of poverty and the connections between health and social conditions and present an opportunity to move beyond narrow sectoral interventions and to develop comprehensive social responses and participatory processes that address the root causes of health inequity. Considering the complexity and magnitude of health, poverty, and environmental issues in cities, it is clear that improvements in health and health equity demand not only changes in the physical and social environment of cities, but also an integrated approach that takes into account the wider socioeconomic and contextual factors affecting health. Integrated or multilevel approaches should address not only the immediate, but also the underlying and particularly the fundamental causes at societal level of related health issues. The political and legal organization of the policy-making process has been identified as a major determinant of urban and global health, as a result of the role it plays in creating possibilities for participation, empowerment, and its influence on the content of public policies and the distribution of scarce resources. This paper argues that it is essential to adopt a long-term multisectoral approach to address the social determinants of health in urban settings. For comprehensive approaches to address the social determinants of health effectively and at multiple levels, they need explicitly to tackle issues of participation, governance, and the politics of power, decision making, and empowerment.

What is known about the safety of multivitamin-multimineral supplements for the generally healthy population? Theoretical basis for harm.

Assessment of the safety of nutrients presents a challenge different from that posed by the assessment of other chemicals in food such as additives or contaminants. Because nutrients are essential, a dose-response relation exists at both ends of the intake range, separated by a safe range of intake that reflects normal homeostatic processes. The safe intake may not be the same for all population groups and life stages. The size of the safe intake range for each nutrient will vary and in a few cases may be very small. Certain nutrients such as vitamin A and manganese have known and potentially serious adverse effects at high intakes, whereas others such as iron or vitamin C may have more minor adverse effects that are readily reversible and may only be associated with supplement intake. The risk of harm occurring from taking dietary supplements will depend on the safe intake range of the nutrient concerned, the susceptibility of the individual, and the likely intake of the same nutrient from other supplements or the rest of the diet. In many cases, the available database for the safety of nutrients is very limited because the studies, where available, were not designed to assess adverse effects but may have detected problems when they occurred. Further information on the safety of nutrients could be obtained through careful experimental design.