Chemometric modelling to relate antioxidants, neutral lipid fatty acids and flavour components in chicken breast

Relationships among quality factors in retailed free-range, corn-fed, organic, and conventional chicken breasts (9) were modeled using chemometric approaches. Use of principal component analysis (PCA) to neutral lipid composition data explained the majority (93%) of variability (variance) in fatty acid contents in 2 significant multivariate factors. PCA explained 88 and 75% variance in 3 factors for, respectively, flame ionization detection (FID) and nitrogen phosphorus (NPD) components in chromatographic flavor data from cooked chicken after simultaneous distillation extraction. Relationships to tissue antioxidant contents were modeled. Partial least square regression (PLS2), interrelating total data matrices, provided no useful models. By using single antioxidants as Y variables in PLS (1), good models (r2 values > 0.9) were obtained for alpha-tocopherol, glutathione, catalase, glutathione peroxidase, and reductase and FID flavor components and among the variables total mono and polyunsaturated fatty acids and subsets of FID, and saturated fatty acid and NPD components. Alpha-tocopherol had a modest (r2 = 0.63) relationship with neutral lipid n-3 fatty acid content. Such factors thus relate to flavor development and quality in chicken breast meat

The lipid peroxidation product 4-hydroxy-2-nonenal:advances in chemistry and analysis

4-Hydroxy-2-nonenal (HNE) is one of the most studied products of phospholipid peroxidation, owing to its reactivity and cytotoxicity. It can be formed by several radical-dependent oxidative routes involving the formation of hydroperoxides, alkoxyl radicals, epoxides, and fatty acyl cross-linking reactions. Cleavage of the oxidized fatty acyl chain results in formation of HNE from the methyl end, and 9-oxo-nonanoic acid from the carboxylate or esterified end of the chain, although many other products are also possible. HNE can be metabolized in tissues by a variety of pathways, leading to detoxification and excretion. HNE-adducts to proteins have been detected in inflammatory situations such as atherosclerotic lesions using polyclonal and monoclonal antibodies, which have also been applied in ELISAs and western blotting. However, in order to identify the proteins modified and the exact sites and nature of the modifications, mass spectrometry approaches are required. Combinations of enrichment strategies with targetted mass spectrometry routines such as neutral loss scanning are now facilitating detection of HNE-modified proteins in complex biological samples. This is important for characterizing the interactions of HNE with redox sensitive cell signalling proteins and understanding how it may modulate their activities either physiologically or in disease

Researches in pyrimidine chemistry: Some potential purine and folic acid antagonists

The use of purine and folic acid antagonists in Cancer chemotherapy is reviewed and discussed and the syntheses of some potential purine and folic acid antagonists are recorded. Synthetic methods for the preparation of the pyrimido-(4:5.b)-pyrazine (pteridine) ring system are reviewed with particular reference to the unambiguous synthesis of substituted pteridines. The preparation of 7-amino-6-arylpteridines and 7-hydroxy-6-aryIpteridines by the condensation of 4-amino-5-nitrosopyrinddines with arylacetonitriles and arylacetyl chlorides respectively is reported; thus, providing a new and unambiguous method for the synthesis of these compounds. Pteridines with an amino group in the pyrazine portion of the nucleus have not previously been described. The structure of these compounds is confirmed by their physical and chemical properties. Some of the 7-amino-6-arylpteridine8 have been shown to be antagonists of folic acid when tested microbiologically but none of the compounds tested had any chemotherapeutic effect on the Walker Rat Carcinoma. 2:4:7-Triamino-6-pheryIpteridine is of interest, however, in that it causes hypertrophy of the kidney. The second part of the thesis is concerned with the preparation and reactions of quaternary salts from 2-chloro-5~nitropyrimidines. It is shown that 2:4-dichloro-5-nitropyrimdines react with 2-aminopyridines to yield quaternary salts involving the 2-chloro-qroup of the pyrimidine ring and the cyclic nitrogen atom of the 2-amincpyridine moiety; the 4-chloro group reacts normally with the amino group of 2-aminopyridine. The formation of this type of quaternary salt is a novel reaction in the pyrimidine series and indicates a difference in reactivity between 2- and 4-chloro groups in 2:4-dichloro 5-nitropyrimidaines. Several 2-chloro-5-nitropyrimidines have been shown to form quaternary salts of the above type with 2-aminopyridine and pyridine, but with isoquinoline a different reaction occurs to give 1:2 disubstituted 1:2-dihydro-isoquinolines. The reaction of the quaternary salts formed in the above reaction with ammonia, amines, alcohols and phenols is described and in this way new 2-amino, 2-substituted-amino, alkoxyl and aryloxy-4-(2'-pyridyl)amino-5-nitro pyrimidines have been prepared. The reaction of these quaternary salts with amines and hydroxy compounds is discussed with a view to elucidating the reaction mechanism. By reduction of the 5-nitro group of these derived pyrimidines several substituted 5-aminopyrimidines have been prepared and converted to the corresponding pyrimidotriazoles and dihydropteridines. The former, which are potential purine antagonists, have been tested for chemotherapeutic action on the Walker Rat Carcinoma but are inactive.<p

Health Impacts of Climate Change in the Solomon Islands: An Assessment and Adaptation Action Plan

The Pacific island countries are particularly vulnerable to the environmental changes wrought by global climate change such as sea level rise, more frequent and intense extreme weather events and increasing temperatures. The potential biophysical changes likely to affect these countries have been identified and it is important that consideration be given to the implications of these changes on the health of their citizens.The potential health impacts of climatic changes on the population of the Solomon Islands were assessed through the use of a Health Impact Assessment framework. The process used a collaborative and consultative approach with local experts to identify the impacts to health that could arise from local environmental changes, considered the risks associated with these and proposed appropriate potential adaptive responses. Participants included knowledgeable representatives from the biophysical, socio-economic, infrastructure, environmental diseases and food sectors.The risk assessments considered both the likelihood and consequences of the health impacts occurring using a qualitative process. To mitigate the adverse effects of the health impacts, an extensive range of potential adaptation strategies were developed. The overall process provided an approach that could be used for further assessments as well as an extensive range of responses which could be used by sectors and to assist future decision making associated with the Solomon Islands’ responses to climate change

Health Consequence Scales for Use in Health Impact Assessments of Climate Change

While health impact assessment (HIA) has typically been applied to projects, plans or policies, it has significant potential with regard to strategic considerations of major health issues facing society such as climate change. Given the complexity of climate change, assessing health impacts presents new challenges that may require different approaches compared to traditional applications of HIA. This research focuses on the development of health consequence scales suited to assessing and comparing health effects associated with climate change and applied within a HIA framework. This assists in setting priorities for adaptation plans to minimize the public health impacts of climate change. The scales presented in this paper were initially developed for a HIA of climate change in Perth in 2050, but they can be applied across spatial and temporal scales. The design is based on a health effects pyramid with health measures expressed in orders of magnitude and linked to baseline population and health data. The health consequence measures are combined with a measure of likelihood to determine the level of risk associated with each health potential health impact. In addition, a simple visual framework that can be used to collate, compare and communicate the level of health risks associated with climate change has been developed

Lipoproteins as targets and markers of lipoxidation

Lipoproteins are essential systemic lipid transport particles, composed of apolipoproteins embedded in a phospholipid and cholesterol monolayer surrounding a cargo of diverse lipid species. Many of the lipids present are susceptible to oxidative damage by lipid peroxidation, giving rise to the formation of reactive lipid peroxidation products (rLPPs). In view of the close proximity of the protein and lipid moieties within lipoproteins, the probability of adduct formation between rLPPs and amino acid residues of the proteins, a process called lipoxidation, is high. There has been interest for many years in the biological effects of such modifications, but the field has been limited to some extent by the availability of methods to determine the sites and exact nature of such modification. More recently, the availability of a wide range of antibodies to lipoxidation products, as well as advances in analytical techniques such as liquid chromatography tandem mass spectrometry (LC-MSMS), have increased our knowledge substantially. While most work has focused on LDL, oxidation of which has long been associated with pro-inflammatory responses and atherosclerosis, some studies on HDL, VLDL and Lipoprotein(a) have also been reported. As the broader topic of LDL oxidation has been reviewed previously, this review focuses on lipoxidative modifications of lipoproteins, from the historical background through to recent advances in the field. We consider the main methods of analysis for detecting rLPP adducts on apolipoproteins, including their advantages and disadvantages, as well as the biological effects of lipoxidized lipoproteins and their potential roles in diseases

Oxidiative lipidomics coming of age:advances in analysis of oxidized phospholipids in physiology and pathology

Significance: Oxidized phospholipids are now well-recognized as markers of biological oxidative stress and bioactive molecules with both pro-inflammatory and anti-inflammatory effects. While analytical methods continue to be developed for studies of generic lipid oxidation, mass spectrometry (MS) has underpinned the advances in knowledge of specific oxidized phospholipids by allowing their identification and characterization, and is responsible for the expansion of oxidative lipidomics. Recent Advances: Studies of oxidized phospholipids in biological samples, both from animal models and clinical samples, have been facilitated by the recent improvements in MS, especially targeted routines that depend on the fragmentation pattern of the parent molecular ion and improved resolution and mass accuracy. MS can be used to identify selectively individual compounds or groups of compounds with common features, which greatly improves the sensitivity and specificity of detection. Application of these methods have enabled important advances in understanding the mechanisms of inflammatory diseases such as atherosclerosis, steatohepatitis, leprosy and cystic fibrosis, and offer potential for developing biomarkers of molecular aspects of the diseases. Critical Issues and Future Directions: The future in this field will depend on development of improved MS technologies, such as ion mobility, novel enrichment methods and databases and software for data analysis, owing to the very large amount of data generated in these experiments. Imaging of oxidized phospholipids in tissue MS is an additional exciting direction emerging that can be expected to advance understanding of physiology and disease

The Role of Stakeholders in HIA: A Landfill Site and Housing Development in Mundijong, Western Australia

The use of Health Impact Assessment (HIA) as a tool to identify and manage issues relating to health has not been widely adopted in Western Australia. Health Impact Assessment methodology was applied to two concurrent developments in the Shire of Serpentine Jarrahdale, Western Australia. Potential health impacts of the expansionof a sanitary landfill adjacent to a proposed housing development were identified following a literature review and stakeholder interviews. Recommendations to assess the risk to the community in the housing estate through quantitative analysis, and risk management strategies were provided to the Shire. The ability of an existing stakeholder group for the landfill, the South Cardup Landfill Stakeholder Consultative Group, to resolve concerns of the community relating to environmental and social issues were also evaluated. Recommendations to improve collaborative decision making were provided to the Stakeholder Group using the Framework for Democratic Science. The outcomes of the HIA informed the Shire of potential health impacts to assist decision making during the development application process and the design of a local District Structure Plan

Effects of ⁶⁰Co irradiation on Amblyomma hebraeum Koch, 1844 (Acarina : Ixodidae)

The effects of ⁶⁰Co irradiation on Amblyomma hebraeum Koch, 1844 were studied by mating normal females to males irradiated to attain dosages of 0, 2, 4, 6 and 8 kilorad. The males of all 5 groups were observed mating 7 days after being placed on the host. The higher the irradiation dosage received by the males, progressively longer were the feeding periods of the females mated with them and fewer completed their engorgement. Furthermore, the mass of the females when engorged was lower, fewer laid eggs and the number of eggs they laid decreased progressively. None of the egg batches produced by females mated with irradiated males hatched. No chromosomal abnormalities or discrepancies in spermiophore formation were found in the 2 and 4 kilorad group males, while no micro- or macroscopical growth of the 6 and 8 kilorad group male testes took place, although accessory gland development appeared normal. A. hebraeum males have a chromosome complement of 10 bivalents and a univalent sex chromosome.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Chemistry and analysis of HNE and other prominent carbonyl-containing lipid oxidation compounds

The process of lipid oxidation generates a diverse array of small aldehydes and carbonyl-containing compounds, which may occur in free form or esterified within phospholipids and cholesterol esters. These aldehydes mostly result from fragmentation of fatty acyl chains following radical oxidation, and the products can be subdivided into alkanals, alkenals (usually α,β-unsaturated), γ-substituted alkenals and bis-aldehydes. Isolevuglandins are non-fragmented di-carbonyl compounds derived from H2-isoprostanes, and oxidation of the ω−3-fatty acid docosahexenoic acid yield analogous 22 carbon neuroketals. Non-radical oxidation by hypochlorous acid can generate α-chlorofatty aldehydes from plasmenyl phospholipids. Most of these compounds are reactive and have generally been considered as toxic products of a deleterious process. The reactivity is especially high for the α,β-unsaturated alkenals, such as acrolein and crotonaldehyde, and for γ-substituted alkenals, of which 4-hydroxy-2-nonenal and 4-oxo-2-nonenal are best known. Nevertheless, in recent years several previously neglected aldehydes have been investigated and also found to have significant reactivity and biological effects; notable examples are 4-hydroxy-2-hexenal and 4-hydroxy-dodecadienal. This has led to substantial interest in the biological effects of all of these lipid oxidation products and their roles in disease, including proposals that HNE is a second messenger or signalling molecule. However, it is becoming clear that many of the effects elicited by these compounds relate to their propensity for forming adducts with nucleophilic groups on proteins, DNA and specific phospholipids. This emphasizes the need for good analytical methods, not just for free lipid oxidation products but also for the resulting adducts with biomolecules. The most informative methods are those utilizing HPLC separations and mass spectrometry, although analysis of the wide variety of possible adducts is very challenging. Nevertheless, evidence for the occurrence of lipid-derived aldehyde adducts in biological and clinical samples is building, and offers an exciting area of future research