Application of Natural and Modified Biomacromolecules in Miniaturised Separative Analytical Techniques

In pharmaceutical R & D, drug stereochemistry, and consequently the rotation of enantiomers, is very important. Because they act as chiral selectors in vivo, biomacromolecules have been extensively used as chiral selectors for the liquid chromatographic (LC) resolution of enantiomers and more latterly have also been employed in the newer separative technique, capillary electrophoresis (CE). However, at the outset of this research programme, this had generally been restricted to common easily accessible biomacromolecules such as plasma-binding proteins. It was clear that it be would be useful therefore to adapt LC and CE in such a way as would allow the use of a much wider range of biomacromolecules. Accordingly the general aim of this study was to develop LC and CE protocols involving biomacromolecules that would give rise to minimum consumption of the biomacromolecule. To study biomacromolecules in free solution CE, a number of experimental variables had to be established for both optimum chiral discrimination and for investigating biomacromolecule-ligand interactions. The typical and widely used biomacromolecule for chiral discrimination, bovine serum albumin (BSA) was used to study the variables of pH from pH 5.4 to 8.4, concentration of BSA form 0 to 60 M and concentration of organic modifiers in the range 0 – 20 % v/v for chiral selectivity. This involved an investigation into some unusual artefacts such as ghost peaks and stepped baselines, but ultimately the outcome was a successful free solution CE protocol suitable for the rapid evaluation of chiral discrimination of other biomacromolecules. The conditions were: run buffer (30 M protein, 67 mM phosphate (pH 7.4) – methanol (97.5 : 2.5, v/v)), capillary CElect p150, 40 cm (35 cm to detector) x 50 m i.d., temperature of ambient or 25 C and an applied voltage of 10 kV. The ability of other biomacromolecules, such as human serum albumin (HSA), lactoferrin and protamine, to resolve enantiomers was studied using this protocol including looking at the effect of the addition of modifiers to the buffer such as metal ions like manganese and zinc, competing ligands, e.g. warfarin and ibuprofen, and -cyclodextrin. As well as using CE, miniaturisation of LC was also studied in view of the success of biomacromolecule-affinity chiral LC. Two different, but similar, microbore LC protocols were employed, i.e. using the protein in free solution or as a pseudo stationary phase. For the former, a Lichrosorb DIOL stationary phase, based on hydroxyl groups immobilised on silica, was chosen in order to minimise the adsorption of protein to the stationary phase. Using this protocol it was demonstrated that free solution microbore LC could be easily be carried out, therefore used to evaluate chiral discrimination and that the use of the system to study in vivo interactions was feasible. The creation of a biomacromolecule pseudo stationary phase, as opposed to conventional chiral stationary phases where the protein is permanently bonded to the stationary phases, involves the biomacromolecule being adsorbed within the pores of the stationary phase. In this way the overall biomacromolecule structure should not be grossly distorted. Three stationary phases were evaluated, viz wide-pore Nucleosil silica, Nucleosil C8 and Lichrosorb DIOL, for optimum biomacromolecule loading and minimal biomacromolecule leakage when mobile phase was pumped through the column. The Nucleosil silica with adsorbed BSA proved the most successful, e.g. of 3.6 and 4.0 for tryptophan and kynurenine respectively, and robust of the stationary phases with respect to demonstrating the chiral discrimination potential for this system. All the miniaturised systems evaluated were successful, to a greater or lesser degree, for the demonstration of chiral selectivity of biomacromolecules. While CE was better for minimisation of the consumption of the biomacromolecule, it was also important that the biomacromolecule LC systems could be operated in reduced dimensions since these systems have perhaps greater potential for exhibiting enantioselectivity and are more appropriate for the ever increasing need for the study of the interaction of ligands with the biomacromolecule in its ‘natural’ form. With the knowledge gained from this research programme it will now be possible to more easily carry out such studies with much smaller amounts of biomacromolecule, and, accordingly be able to work with biomacromolecules which hitherto it has not been possible to study because of limited availability. While some of the protocols have now been superseded by recent developments the system developed still has potential. The use of such small scale systems offers the potential to study chiral selectivity and drug-biomacromolecule binding of rare or expensive biomacromolecules

Application of natural and modified biomacromolecules in miniaturised separative analytical techniques

In pharmaceutical R & D, drug stereochemistry, and consequently the rotation of enantiomers, is very important. Because they act as chiral selectors in vivo, biomacromolecules have been extensively used as chiral selectors for the liquid chromatographic (LC) resolution of enantiomers and more latterly have also been employed in the newer separative technique, capillary electrophoresis (CE). However, at the outset of this research programme, this had generally been restricted to common easily accessible biomacromolecules such as plasma-binding proteins. It was clear that it be would be useful therefore to adapt LC and CE in such a way as would allow the use of a much wider range of biomacromolecules. Accordingly the general aim of this study was to develop LC and CE protocols involving biomacromolecules that would give rise to minimum consumption of the biomacromolecule. To study biomacromolecules in free solution CE, a number of experimental variables had to be established for both optimum chiral discrimination and for investigating biomacromolecule-ligand interactions. The typical and widely used biomacromolecule for chiral discrimination, bovine serum albumin (BSA) was used to study the variables of pH from pH 5.4 to 8.4, concentration of BSA form 0 to 60 mM and concentration of organic modifiers in the range 0 – 20 % v/v for chiral selectivity. This involved an investigation into some unusual artefacts such as ghost peaks and stepped baselines, but ultimately the outcome was a successful free solution CE protocol suitable for the rapid evaluation of chiral discrimination of other biomacromolecules. The conditions were: run buffer (30 mM protein, 67 mM phosphate (pH 7.4) – methanol (97.5 : 2.5, v/v)), capillary CElect p150, 40 cm (35 cm to detector) x 50 mm i.d., temperature of ambient or 25 °C and an applied voltage of 10 kV. The ability of other biomacromolecules, such as human serum albumin (HSA), lactoferrin and protamine, to resolve enantiomers was studied using this protocol including looking at the effect of the addition of modifiers to the buffer such as metal ions like manganese and zinc, competing ligands, e.g. warfarin and ibuprofen, and b-cyclodextrin. As well as using CE, miniaturisation of LC was also studied in view of the success of biomacromolecule-affinity chiral LC. Two different, but similar, microbore LC protocols were employed, i.e. using the protein in free solution or as a pseudo stationary phase. For the former, a Lichrosorb DIOL stationary phase, based on hydroxyl groups immobilised on silica, was chosen in order to minimise the adsorption of protein to the stationary phase. Using this protocol it was demonstrated that free solution microbore LC could be easily be carried out, therefore used to evaluate chiral discrimination and that the use of the system to study in vivo interactions was feasible. The creation of a biomacromolecule pseudo stationary phase, as opposed to conventional chiral stationary phases where the protein is permanently bonded to the stationary phases, involves the biomacromolecule being adsorbed within the pores of the stationary phase. In this way the overall biomacromolecule structure should not be grossly distorted. Three stationary phases were evaluated, viz wide-pore Nucleosil silica, Nucleosil C8 and Lichrosorb DIOL, for optimum biomacromolecule loading and minimal biomacromolecule leakage when mobile phase was pumped through the column. The Nucleosil silica with adsorbed BSA proved the most successful, e.g. a of 3.6 and 4.0 for tryptophan and kynurenine respectively, and robust of the stationary phases with respect to demonstrating the chiral discrimination potential for this system. All the miniaturised systems evaluated were successful, to a greater or lesser degree, for the demonstration of chiral selectivity of biomacromolecules. While CE was better for minimisation of the consumption of the biomacromolecule, it was also important that the biomacromolecule LC systems could be operated in reduced dimensions since these systems have perhaps greater potential for exhibiting enantioselectivity and are more appropriate for the ever increasing need for the study of the interaction of ligands with the biomacromolecule in its ‘natural’ form. With the knowledge gained from this research programme it will now be possible to more easily carry out such studies with much smaller amounts of biomacromolecule, and, accordingly be able to work with biomacromolecules which hitherto it has not been possible to study because of limited availability. While some of the protocols have now been superseded by recent developments the system developed still has potential. The use of such small scale systems offers the potential to study chiral selectivity and drug-biomacromolecule binding of rare or expensive biomacromolecules.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

An adapted mindfulness-based stress reduction program for elders in a continuing care retirement community: quantitative and qualitative results from a pilot randomized controlled trial.

The purpose of this study was to test the feasibility and effectiveness of an adapted 8-week Mindfulness-Based Stress Reduction (MBSR) program for elders in a continuing care community. This mixed-methods study used both quantitative and qualitative measures. A randomized waitlist control design was used for the quantitative aspect of the study. Thirty-nine elderly were randomized to MBSR (n = 20) or a waitlist control group (n = 19), mean age was 82 years. Both groups completed pre-post measures of health-related quality of life, acceptance and psychological flexibility, facets of mindfulness, self-compassion, and psychological distress. A subset of MBSR participants completed qualitative interviews. MBSR participants showed significantly greater improvement in acceptance and psychological flexibility and in role limitations due to physical health. In the qualitative interviews, MBSR participants reported increased awareness, less judgment, and greater self-compassion. Study results demonstrate the feasibility and potential effectiveness of an adapted MBSR program in promoting mind-body health for elders

A conserved amino acid residue critical for product and substrate specificity in plant triterpene synthases

Triterpenes are structurally complex plant natural products with numerous medicinal applications. They are synthesized through an origami-like process that involves cyclization of the linear 30 carbon precursor 2,3-oxidosqualene into different triterpene scaffolds. Here, through a forward genetic screen in planta, we identify a conserved amino acid residue that determines product specificity in triterpene synthases from diverse plant species. Mutation of this residue results in a major change in triterpene cyclization, with production of tetracyclic rather than pentacyclic products. The mutated enzymes also use the more highly oxygenated substrate dioxidosqualene in preference to 2,3-oxidosqualene when expressed in yeast. Our discoveries provide new insights into triterpene cyclization, revealing hidden functional diversity within triterpene synthases. They further open up opportunities to engineer novel oxygenated triterpene scaffolds by manipulating the precursor supply

Middleborns disadvantaged? testing birth-order effects on fitness in pre-industrial finns

Parental investment is a limited resource for which offspring compete in order to increase their own survival and reproductive success. However, parents might be selected to influence the outcome of sibling competition through differential investment. While evidence for this is widespread in egg-laying species, whether or not this may also be the case in viviparous species is more difficult to determine. We use pre-industrial Finns as our model system and an equal investment model as our null hypothesis, which predicts that (all else being equal) middleborns should be disadvantaged through competition. We found no overall evidence to suggest that middleborns in a family are disadvantaged in terms of their survival, age at first reproduction or lifetime reproductive success. However, when considering birth-order only among same-sexed siblings, first-, middle-and lastborn sons significantly differed in the number of offspring they were able to rear to adulthood, although there was no similar effect among females. Middleborn sons appeared to produce significantly less offspring than first-or lastborn sons, but they did not significantly differ from lastborn sons in the number of offspring reared to adulthood. Our results thus show that taking sex differences into account is important when modelling birth-order effects. We found clear evidence of firstborn sons being advantaged over other sons in the family, and over firstborn daughters. Therefore, our results suggest that parents invest differentially in their offspring in order to both preferentially favour particular offspring or reduce offspring inequalities arising from sibling competition

Age-related patterns of vigorous-intensity physical activity in youth:the International Children’s Accelerometry Database

Abstract Physical activity declines during youth but most evidence reports on combined moderate and vigorous-intensity physical activity. We investigated how vigorous-intensity activity varies with age. Cross-sectional data from 24,025 participants (5.0–18.0 y; from 20 studies in 10 countries obtained 2008–2010) providing ≥ 1 day accelerometer data (International Children's Accelerometry Database (ICAD)). Linear regression was used to investigate age-related patterns in vigorous-intensity activity; models included age (exposure), adjustments for monitor wear-time and study. Moderate-intensity activity was examined for comparison. Interactions were used to investigate whether the age/vigorous-activity association differed by sex, weight status, ethnicity, maternal education and region. A 6.9% (95% CI 6.2, 7.5) relative reduction in mean vigorous-intensity activity with every year of age was observed; for moderate activity the relative reduction was 6.0% (5.6%, 6.4%). The age-related decrease in vigorous-intensity activity remained after adjustment for moderate activity. A larger age-related decrease in vigorous activity was observed for girls (− 10.7%) versus boys (− 2.9%), non-white (− 12.9% to − 9.4%) versus white individuals (− 6.1%), lowest maternal education (high school (− 2.0%)) versus college/university (ns) and for overweight/obese (− 6.1%) versus healthy-weight participants (− 8.1%). In addition to larger annual decreases in vigorous-intensity activity, overweight/obese individuals, girls and North Americans had comparatively lower average vigorous-intensity activity at 5.0–5.9 y. Age-related declines in vigorous-intensity activity during youth appear relatively greater than those of moderate activity. However, due to a higher baseline, absolute moderate-intensity activity decreases more than vigorous. Overweight/obese individuals, girls, and North Americans appear especially in need of vigorous-intensity activity promotion due to low levels at 5.0–5.9 y and larger negative annual differences

Influence of Guideline Operationalization on Youth Activity Prevalence in the International Children's Accelerometry Database

Introduction The United Kingdom and World Health Organization recently changed their youth physical activity (PA) guidelines from 60 min of moderate- to vigorous-intensity PA (MVPA) every day, to an average of 60 min of MVPA per day, over a week. The changes are based on expert opinion due to insufficient evidence comparing health outcomes associated with different guideline definitions. This study used the International Children’s Accelerometry Database to compare approaches to calculating youth PA compliance and associations with health indicators. Methods Cross-sectional accelerometer data (n = 21,612, 5–18 yr) were used to examine compliance with four guideline definitions: daily method (DM; ≥60 min MVPA every day), average method (AM; average of ≥60 min MVPA per day), AM5 (AM compliance and ≥5 min of vigorous PA [VPA] on ≥3 d), and AM15 (AM compliance and ≥15 min VPA on ≥3 d). Associations between compliance and health indicators were examined for all definitions. Results Compliance varied from 5.3% (DM) to 29.9% (AM). Associations between compliance and health indicators were similar for AM, AM5, and AM15. For example, compliance with AM, AM5, and AM15 was associated with a lower BMI z-score (statistics are coefficient [95% CI]): AM (−0.28 [−0.33 to −0.23]), AM5 (−0.28 [−0.33 to −0.23], and AM15 (−0.30 [−0.35 to −0.25]). Associations between compliance and health indicators for DM were similar/weaker, possibly reflecting fewer DM-compliant participants with health data and lower variability in exposure/outcome data. Conclusions Youth completing 60 min of MVPA every day do not experience superior health benefits to youth completing an average of 60 min of MVPA per day. Guidelines should encourage youth to achieve an average of 60 min of MVPA per day. Different guideline definitions affect inactivity prevalence estimates; this must be considered when analyzing data and comparing studies.publishedVersionPaid open acces

Alternative splicing of TIA-1 in human colon cancer regulates VEGF isoform expression, angiogenesis, tumour growth and bevacizumab resistance

© 2014 The Authors. The angiogenic capability of colorectal carcinomas (CRC), and their susceptibility to anti-angiogenic therapy, is determined by expression of vascular endothelial growth factor (VEGF) isoforms. The intracellular protein T-cell Intracellular Antigen (TIA-1) alters post-transcriptional RNA processing and binds VEGF-A mRNA. We therefore tested the hypothesis that TIA-1 could regulate VEGF-A isoform expression in colorectal cancers. TIA-1 and VEGF-A isoform expression was measured in colorectal cancers and cell lines. We discovered that an endogenous splice variant of TIA-1 encoding a truncated protein, short TIA-1 (sTIA-1) was expressed in CRC tissues and invasive K-Ras mutant colon cancer cells and tissues but not in adenoma cell lines. sTIA-1 was more highly expressed in CRC than in normal tissues and increased with tumour stage. Knockdown of sTIA-1 or over-expression of full length TIA-1 (flTIA-1) induced expression of the anti-angiogenic VEGF isoform VEGF-A 165 b. Whereas flTIA-1 selectively bound VEGF-A 165 mRNA and increased translation of VEGF-A 165 b, sTIA-1 prevented this binding. In nude mice, xenografted colon cancer cells over-expressing flTIA-1 formed smaller, less vascular tumours than those expressing sTIA-1, but flTIA-1 expression inhibited the effect of anti-VEGF antibodies. These results indicate that alternative splicing of an RNA binding protein can regulate isoform specific expression of VEGF providing an added layer of complexity to the angiogenic profile of colorectal cancer and their resistance to anti-angiogenic therapy

WARNING: Physics Envy May Be Hazardous To Your Wealth!

The quantitative aspirations of economists and financial analysts have for many years been based on the belief that it should be possible to build models of economic systems - and financial markets in particular - that are as predictive as those in physics. While this perspective has led to a number of important breakthroughs in economics, "physics envy" has also created a false sense of mathematical precision in some cases. We speculate on the origins of physics envy, and then describe an alternate perspective of economic behavior based on a new taxonomy of uncertainty. We illustrate the relevance of this taxonomy with two concrete examples: the classical harmonic oscillator with some new twists that make physics look more like economics, and a quantitative equity market-neutral strategy. We conclude by offering a new interpretation of tail events, proposing an "uncertainty checklist" with which our taxonomy can be implemented, and considering the role that quants played in the current financial crisis.Comment: v3 adds 2 reference

Harmonising data on the correlates of physical activity and sedentary behaviour in young people: Methods and lessons learnt from the international Children's Accelerometry database (ICAD).

BACKGROUND: Large, heterogeneous datasets are required to enhance understanding of the multi-level influences on children's physical activity and sedentary behaviour. One route to achieving this is through the pooling and co-analysis of data from multiple studies. Where this approach is used, transparency of the methodology for data collation and harmonisation is essential to enable appropriate analysis and interpretation of the derived data. In this paper, we describe the acquisition, management and harmonisation of non-accelerometer data in a project to expand the International Children's Accelerometry Database (ICAD). METHOD: Following a consultation process, ICAD partners were requested to share accelerometer data and information on selected behavioural, social, environmental and health-related constructs. All data were collated into a single repository for cataloguing and harmonisation. Harmonised variables were derived iteratively, with input from the ICAD investigators and a panel of invited experts. Extensive documentation, describing the source data and harmonisation procedure, was prepared and made available through the ICAD website. RESULTS: Work to expand ICAD has increased the number of studies with longitudinal accelerometer data, and expanded the breadth of behavioural, social and environmental characteristics that can be used as exposure variables. A set of core harmonised variables, including parent education, ethnicity, school travel mode/duration and car ownership, were derived for use by the research community. Guidance documents and facilities to enable the creation of new harmonised variables were also devised and made available to ICAD users. An expanded ICAD database was made available in May 2017. CONCLUSION: The project to expand ICAD further demonstrates the feasibility of pooling data on physical activity, sedentary behaviour and potential determinants from multiple studies. Key to this process is the rigorous conduct and reporting of retrospective data harmonisation, which is essential to the appropriate analysis and interpretation of derived data. These documents, made available through the ICAD website, may also serve as a guide to others undertaking similar projects