Biochemical aspects of chronic hyperoxia in mammals

The primary objective of the work described in this thesis was to investigate some of the effects of chronic oxygen toxicity in mammals. This thesis describes in vivo changes in certain metabolites and enzymes following the exposure of mice and rats to increased concentrations of oxygen at atmospheric pressure. The introductory section reviews the historical background to oxygen toxicity, delineates its two forms and describes their aetiology. The physical and chemical properties of oxygen which contribute to its unusual reactivity are discussed, together with the reactive species of oxygen which may be responsible for its toxicity. To complete the introduction, the known effects of oxygen on metabolism are reviewed. In order to pursue these studies it was necessary to design an apparatus capable of providing a controlled high oxygen atmosphere. Its construction and operation is described. Results obtained indicated that the levels of the protective enzymes superoxide dismutase and catalase varied in lung, liver and brain of mice following exposure to increased oxygen levels. Overall protein levels were also found to vary, so an experiment involving a polyacrylamide gel separation was performed to reveal any qualitative differences. Another experiment monitored the changes in free amino acids in brain, liver, lung and muscle. A few possible deviations from normal were detected but these changes were not consistent between the tissues studied. Results are presented of the changes in some gross physical parameters and the effect of 3 prostaglandin inhibitors on these in vivo changes. Other experiments revealed the changes in haematocrit, in retinol and in haemoglobin levels. For comparative purposes some of the above measurements were also applied to samples of body fluids from men suffering a mild experimental oxygen toxicity. The relevance of these results to the toxic effects of oxygen in mammals is discussed

What is a sustainable healthy diet? A discussion paper

The food system today is destroying the environment upon which future food production depends. While the food system generates enough food energy for our population of over 7 billion it does not deliver adequate and affordable nutrition for all. About half the global population is inadequately or inappropriately nourished. Without action, these problems are set to become acute. As our global population grows, urbanises and becomes wealthier, it is demanding more resource intensive, energy rich foods. What, and how much we eat directly affects what, and how much is produced. We therefore need to consume more „sustainable diets‟ – diets that have lower environmental impacts, and are healthier. But what does such a diet look like? Can health, environmental sustainability, and all the other goals we have for our food system really be reconciled, or will there be trade offs

Variation in structure and properties of poly(glycerol adipate) via control of chain branching during enzymatic synthesis

Poly (glycerol adipate) (PGA) can be produced from divinyl adipate and unprotected glycerol by an enzymatic route to generate a polymer with relatively low molar mass (12 kDa). PGA bears a pendant hydroxyl group which imparts a hydrophilic character to this water insoluble polymer. We have examined the effect of synthesis temperature on polymer characteristics through various techniques including FT-IR, 1H and 13C NMR, surface and thermal analysis, both to expand the data already present in the literature about this material and to understand better its properties for potential pharmaceutical applications. The use of a lipase (Novozym 435) as a catalyst suppresses cross-linking at the pendant glyceryl hydroxyl through steric hindrance at the active site, thus producing polymers with low degrees of branching (5–30%), and removes the need for any pre- or post-polymerization protection/deprotection reactions. Careful temperature control during synthesis can give polymers with reproducible molecular weights and reduced amounts of polymer branching compared to synthesis at higher temperatures. Due to the ability of the synthetic route to produce a range of structures, PGA generated by enzymatic routes may emerge as a useful biodegradable polymer platform to engineer solid dispersions or nanoparticles for healthcare applications

Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study

A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4

A century of trends in adult human height

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5-22.7) and 16.5 cm (13.3-19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8-144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities 1,2 . This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity 3�6 . Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55 of the global rise in mean BMI from 1985 to 2017�and more than 80 in some low- and middle-income regions�was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing�and in some countries reversal�of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories. © 2019, The Author(s)

Method for attaching polyethylene glycol to macromolecules

A process for attaching a polyethylene glycol compound to a macromolecule to prepare a conjugate or adduct between the polyethylene glycol compound and the macromolecule is described. The process comprises the steps of (1) preparing an activated PEG or an activated PEG derivative by incorporating an acrylic ester, an acrylic thioester or an acrylamido group into the PEG or PEG derivative; (2) reacting the activated PEG or PEG derivative with a macromolecular material comprising one or more sulphydryl groups, primary amino groups and/or secondary amino groups and (3) recovering the conjugate of the PEG or PEG derivative and the macromolecular material

Cationic polymer-nucleic acid complexes and methods of making them

A nucleic acid complex for delivering a nucleic acid or a derivative thereof to a cell comprises the components: A. a nucleic acid or a derivative thereof; B. a cationic polymer; and C. a preformed polyethylene glycol-cationic polymer copolymer. The complex has a conformation in which the nucleic acid or derivative thereof is condensed and wherein component C is bound to component A such that the poylethylene glycol groups of component C are located at the surface of the complex. The complexes which are stable to aggregation are useful for the delivery of nucleic acids or derivatives thereof to cells in biological systems