Mammalian Health Research Articles

Phosphatidylethanolamine Metabolism in Health and Disease.

Phosphatidylethanolamine (PE) is the second most abundant glycerophospholipid in eukaryotic cells. The existence of four only partially redundant biochemical pathways that produce PE, highlights the importance of this essential phospholipid. The CDP-ethanolamine and phosphatidylserine decarboxylase pathways occur in different subcellular compartments and are the main sources of PE in cells. Mammalian development fails upon ablation of either pathway. Once made, PE has diverse cellular functions that include serving as a precursor for phosphatidylcholine and a substrate for important posttranslational modifications, influencing membrane topology, and promoting cell and organelle membrane fusion, oxidative phosphorylation, mitochondrial biogenesis, and autophagy. The importance of PE metabolism in mammalian health has recently emerged following its association with Alzheimer's disease, Parkinson's disease, nonalcoholic liver disease, and the virulence of certain pathogenic organisms.

Direct renal effects of a fructose-enriched diet: interaction with high salt intake.

Consumption of fructose has increased during the last 50 years. Excessive fructose consumption has a detrimental effect on mammalian health but the mechanisms remain unclear. In humans, a direct relationship exists between dietary intake of added sugars and increased risk for cardiovascular disease mortality (52). While the causes for this are unclear, we recently showed that fructose provided in the drinking water induces a salt-dependent increase in blood pressure in Sprague-Dawley rats in a matter of days (6). However, little is known about the effects of fructose in renal salt handling and whether combined intake of high fructose and salt can lead to salt-sensitive hypertension before the development of metabolic abnormalities. The long-term (more than 4 wk) adverse effects of fructose intake on renal function are not just due to fructose but are also secondary to alterations in metabolism which may have an impact on renal function. This minireview focuses on the acute effect of fructose intake and its effect on salt regulation, as they affect blood pressure.

Naphthenic Acid Mixtures from Oil Sands Process-Affected Water Enhance Differentiation of Mouse Embryonic Stem Cells and Affect Development of the Heart.

Extraction of petrochemicals from the surface mining of oil sand deposits results in generation of large volumes of oil sands process-affected water (OSPW). Naphthenic acids (NA) are generally considered to be among the most toxic components of OSPW. Previous studies have shown that NAs are toxic to aquatic organisms, however knowledge of their effects on mammalian health and development is limited. In the present study, we evaluated the developmental effects of an NA extract prepared from fresh OSPW on differentiating mouse embryonic stem cells (ESC). We found that treatment of differentiating cells with the NA extract at noncytotoxic concentrations alters expression of various lineage specification markers and development of the heart. Notably, expression of cardiac specific markers such as Nkx2.5, Gata4, and Mef2c were significantly up-regulated. Moreover, exposure to the NA extract enhanced differentiation of embryoid bodies and resulted in the early appearance of spontaneously beating clusters. Interestingly, exposure of undifferentiated mouse ESCs to the NA extract did not change the expression level of pluripotency markers (i.e., Oct4, Nanog, and Sox2). Altogether, these data identify some of the molecular pathways affected by components within this NA extract during differentiation of mammalian cells.

Macronutrients and caloric intake in health and longevity.

Both lifespan and healthspan are influenced by nutrition, with nutritional interventions proving to be robust across a wide range of species. However, the relationship between nutrition, health and aging is still not fully understood. Caloric restriction is the most studied dietary intervention known to extend life in many organisms, but recently the balance of macronutrients has been shown to play a critical role. In this review, we discuss the current understanding regarding the impact of calories and macronutrient balance in mammalian health and longevity, and highlight the key nutrient-sensing pathways that mediate the effects of nutrition on health and ageing.

Vascular endothelial growth factors: multitasking functionality in metabolism, health and disease.

Vascular endothelial growth factors (VEGFs) bind to VEGF receptor tyrosine kinases (VEGFRs). The VEGF and VEGFR gene products regulate diverse regulatory pathways in mammalian development, health and disease. The interaction between a particular VEGF and its cognate VEGFR activates multiple signal transduction pathways which regulate different cellular responses including metabolism, gene expression, proliferation, migration, and survival. The family of VEGF isoforms regulate vascular physiology and promote tissue homeostasis. VEGF dysfunction is implicated in major chronic disease states including atherosclerosis, diabetes, and cancer. More recent studies implicate a strong link between response to VEGF and regulation of vascular metabolism. Understanding how this family of multitasking cytokines regulates cell and animal function has implications for treating many different diseases.

Roles of mutagenic translesion synthesis in mammalian genome stability, health and disease.

Most spontaneous and DNA damage-induced nucleotide substitutions in eukaryotes depend on translesion synthesis polymerases Rev1 and Pol ζ, the latter consisting of the catalytic subunit Rev3 and the accessory protein Rev7. Here we review the regulation, and the biochemical and cellular functions, of Rev1/Pol ζ-dependent translesion synthesis. These are correlated with phenotypes of mouse models with defects in Rev1, Rev3 or Rev7. The data indicate that Rev1/Pol ζ-mediated translesion synthesis is important for adaptive immunity while playing paradoxical roles in oncogenesis. On the other hand, by enabling the replication of endogenously damaged templates, Rev1/Pol ζ -dependent translesion synthesis protects stem cells, thereby preventing features of ageing. In conclusion, Rev1/Pol ζ-dependent translesion synthesis at DNA helix-distorting nucleotide lesions orchestrates pleiotropic responses that determine organismal fitness and disease.

Modeling the study of DNA damage responses in mice.

Damaged DNA has a profound impact on mammalian health and overall survival. In addition to being the source of mutations that initiate cancer, the accumulation of toxic amounts of DNA damage can cause severe developmental diseases and accelerate aging. Therefore, understanding how cells respond to DNA damage has become one of the most intense areas of biomedical research in the recent years. However, whereas most mechanistic studies derive from in vitro or in cellulo work, the impact of a given mutation on a living organism is largely unpredictable. For instance, why BRCA1 mutations preferentially lead to breast cancer whereas mutations compromising mismatch repair drive colon cancer is still not understood. In this context, evaluating the specific physiological impact of mutations that compromise genome integrity has become crucial for a better dimensioning of our knowledge. We here describe the various technologies that can be used for modeling mutations in mice and provide a review of the genes and pathways that have been modeled so far in the context of DNA damage responses.

Endoplasmic reticulum stress signaling in mammalian oocytes and embryos: life in balance.

Mammalian oocytes and embryos are exquisitely sensitive to a wide range of insults related to physical stress, chemical exposure, and exposures to adverse maternal nutrition or health status. Although cells manifest specific responses to various stressors, many of these stressors intersect at the endoplasmic reticulum (ER), where disruptions in protein folding and production of reactive oxygen species initiate downstream signaling events. These signals modulate mRNA translation and gene transcription, leading to recovery, activation of autophagy, or with severe and prolonged stress, apoptosis. ER stress signaling has recently come to the fore as a major contributor to embryo demise. Accordingly, agents that modulate or inhibit ER stress signaling have yielded beneficial effects on embryo survival and long-term developmental potential. We review here the mechanisms of ER stress signaling, their connections to mammalian oocytes and embryos, and the promising indications that interventions in this pathway may provide new opportunities for improving mammalian reproduction and health.

Singlet-oxygen-derived products from linoleate activate Nrf2 signaling in skin cells

Linoleates are required for normal mammalian health and development, but they are also prone to oxidation, resulting in biologically active metabolites such as hydroxyoctadecadienoic acids (HODEs). To investigate the biological activity of 9-EZ-HODE, 10-EZ-HODE, 12-ZE-HODE, and 13-ZE-HODE, the metabolites of singlet-oxygen-derived products from linoleates, we assessed adaptive cytoprotection in HaCaT skin cells. Treating HaCaT cells with sublethal concentrations of 10-EZ-HODE and 12-ZE-HODE, which are singlet-oxygen-mediated specific oxidation metabolites of linoleates, but not 9-EZ-HODE and 13-ZE-HODE, caused resistance to hydrogen peroxide-induced oxidative damage. Microarray analysis of HaCaT cells revealed that 10-EZ-HODE and 12-ZE-HODE induced cellular antioxidant genes that are responsive to nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), such as heme oxygenase-1 and glutathione synthesis enzymes. Although 10-EZ-HODE and 12-ZE-HODE did not induce Nrf2 mRNA, treatment with these metabolites increased the intranuclear expression of Nrf2. These results suggest that 10-EZ-HODE and 12-ZE-HODE initiate adaptive responses that reduce the damage caused by oxidative stress.

76 EX VIVO MODEL TO STUDY THE EFFECT OF ACUTE EXPOSURE TO DI-(2-ETHYLHEXYL) PHTHALATE ON BOVINE OOCYTE MATURATION AND DEVELOPMENTAL COMPETENCE

Di-(2-ethylhexyl) phthalate (DEHP) and its metabolites are environmental toxicants that potentially affect mammalian health. However, their effects on ovarian function, and in particular oocyte developmental competence, are less known. We established a model of acute exposure to DEHP to examine its immediate and long-term effects on follicles and oocyte competence. Lactating Holstein cows were synchronized and gavaged with DEHP (OXPLAST®O, ZAK, Kędzierzyn-Koźle, Poland; 100 mg kg–1 per day, n = 4) or water (n = 5) for 3 days. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed high DEHP metabolite levels in both the urine and plasma during DEHP exposure (acute phase), followed by relatively low levels through the subsequent 34 days (chronic phase). In the chronic phase, cows were synchronized with prostaglandin (PG)2α-gonadotropin-releasing hormone (GnRH) (day 0) and ovaries were monitored by ultrasonography (Aloka SSD-900, 7.5 MHz; Aloka, Tokyo, Japan) through an entire oestrous cycle. On Day 18 of the cycle, cows were administered with PG2α and within 30 h, follicular fluid (FF) was aspirated from the preovulatory follicle by ultrasonic scanner connected to a vaginal sector transducer (7.5-MHz, PieMedical, Maastricht, the Netherlands). For each group, the FF were pooled and analysed for DEHP metabolites (MEHP, MEHOH, MEHHP) by LC-MS/MS. These FF further served as maturation medium for in vitro embryo production. For all cows, FF aspirated before DEHP administration did not contain any of the examined metabolites. However, during the chronic phase, the level of MEHP (but not MEHOH, MEHHP) was higher (22.31 v. 0.00 nM) in the FF aspirated from treated cows (FF-DEHP, n = 4) relative to controls (FF-control, n = 5). To examine the effect of MEHP on oocyte maturation and developmental competence, cumulus-oocyte complexes aspirated from abattoir ovaries (n = 250 × 5 replicates) were matured (22 h, 38.5°C, 5% CO2) in FF-control or FF-DEHP, then in vitro fertilized (18 h, 38.5°C, 5% CO2) and cultured for 8 days in KSOM (38.5°C, 5% CO2, 5% O2). The proportion of oocytes with expanded cumulus cells (84.5 v. 81.2%) and distribution of oocyte within cortical granule types (I–III) did not differ between groups at the end of maturation. The proportion of oocytes with metaphase II plate and first polar body (i.e. nuclear-matured) was lower in the DEHP-treated group relative to the control (34.7 v. 64.3%, n = 100/group; P < 0.0001). Moreover, a decreased proportion of 2- to 4-cell-stage embryos (53.12 v. 67.61%; P < 0.04) and 7-day blastocysts (4.2 v. 12%; P < 0.08) was noted for the FF-DEHP group. In summary, the findings reveal long-lasting effects of DEHP exposure, expressed by MEHP incorporation into the FF, suggesting potential deleterious effects on developmental competence of the follicle-enclosed oocyte.

Stem cell health and tissue regeneration in microgravity.

Exposure to microgravity causes significant mechanical unloading of mammalian tissues, resulting in rapid alterations of their physiology, which poses a significant risk for long-duration manned spaceflight. The immediate degenerative effects of spaceflight we understand best are those studied during short-term low-Earth-orbit experiments, and include rapid microgravity-adaptive bone and muscle loss, loss of cardiovascular capacity, defects in wound and bone fracture healing, and impaired immune function. Over the long-term, exposure to microgravity may cause severe deficits in mammalian stem cell-based tissue regenerative health, including, osteogenesis, hematopoiesis, and lymphopoeisis, as well as cause significant stem cell-based tissue degeneration in amphibian tail and lens regeneration. To address the needs for stem cell and other cell science research on the International Space Station (ISS), NASA has developed the new Bioculture System that will allow investigators to initiate and conduct on-orbit experiments that astronauts will be able to monitor and interact with during the course of cell cultures. This cell culture capability combined with advanced technologies for molecular biology and on-orbit measurement of gene expression (WetLab2) and other tools that are now coming online bring the ISS National Laboratory a step closer to becoming a fully functional space laboratory for advancing space biological sciences.

Altered dietary methionine differentially impacts glutathione and methionine metabolism in long-living growth hormone-deficient Ames dwarf and wild-type mice.

BackgroundExtending mammalian health span and life span has been achieved under a variety of dietary restriction protocols. Reducing the intake of a specific amino acid has also been shown to extend health and longevity. We recently reported that methionine (MET) restriction is not effective in life span extension in growth hormone (GH) signaling mutants. To better understand the apparent necessity of GH in the ‘sensing’ of altered dietary MET, the current study was designed to evaluate MET and glutathione (GSH) metabolism (as well as other pathways) in long-living GH-deficient Ames dwarf and wild-type mice following 8 weeks of restricted (0.16%), low (0.43%), or enriched (1.3%) dietary MET consumption. Metabolite expression was examined in liver tissue, while gene and protein expression were evaluated in liver, kidney, and muscle tissues.ResultsBody weight was maintained in dwarf mice on the MET diets, while wild-type mice on higher levels of MET gained weight. Liver MET levels were similar in Ames mice, while several MET pathway enzymes were elevated regardless of dietary MET intake. Transsulfuration enzymes were also elevated in Ames mice but differences in cysteine levels were not different between genotypes. Dwarf mice maintained higher levels of GSH on MET restriction compared to wild-type mice, while genotype and diet effects were also detected in thioredoxin and glutaredoxin. MET restriction increased transmethylation in both genotypes as indicated by increased S-adenosylmethionine (SAM), betaine, and dimethylglycine. Diet did not impact levels of glycolytic components, but dwarf mice exhibited higher levels of key members of this pathway. Coenzyme A and measures of fatty acid oxidation were elevated in dwarf mice and unaffected by diet.ConclusionsThis component analysis between Ames and wild-type mice suggests that the life span differences observed may result from the atypical MET metabolism and downstream effects on multiple systems. The overall lack of responsiveness to the different diets is well reflected across many metabolic pathways in dwarf mice indicating the importance of GH signaling in the ability to discriminate dietary amino acid levels.Electronic supplementary materialThe online version of this article (doi:10.1186/2046-2395-3-10) contains supplementary material, which is available to authorized users.

Consequences of ongoing retrotransposition in mammalian genomes

Consequences of ongoing retrotransposition in mammalian genomes Patrick H Maxwell Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA Abstract: Retrotransposons can have significant influences on gene expression and genome stability through their ability to integrate reverse-transcript copies of their sequences at new genomic locations by retrotransposition. These elements have been long known to retrotranspose in mammalian germ cells to give rise to inherited insertion alleles, but more recent work has also shown that retrotransposition can occur in mammalian somatic cells, particularly in brain tissue and tumors. Retrotransposition makes appreciable contributions to spontaneous disease-causing alleles in humans and a more significant contribution to spontaneous mutations in mice. Genome-wide studies have found high levels of polymorphic retrotransposon insertions in human populations that are consistent with ongoing retrotransposition. Many insertions do not disrupt exons, but insertions into introns or flanking genes can alter gene expression patterns, generate truncated or antisense gene transcripts, alter splicing patterns, or result in premature polyadenylation of gene transcripts. Furthermore, the very high genomic copy numbers of these elements can lead to nonallelic homologous recombination events that produce gene deletions/duplications and genome rearrangements, and can also lead to evolution of particular insertions or types of elements to have cellular functions through exaptation. Mobility of these elements occurs despite multiple epigenetic mechanisms to restrict their expression. While the potential for retrotransposons to significantly influence mammalian health and cellular functions is clear, substantial research efforts will be needed to fully elucidate the actual contributions of natural levels of mobility of endogenous elements to the health and development of humans and other mammals. Keywords: retrotransposon, human, mouse, mutations, epigenetics, exaptation

Role of β-hydroxybutyrate, its polymer poly-β-hydroxybutyrate and inorganic polyphosphate in mammalian health and disease.

We provide a comprehensive review of the role of β-hydroxybutyrate (β-OHB), its linear polymer poly-β-hydroxybutyrate (PHB), and inorganic polyphosphate (polyP) in mammalian health and disease. β-OHB is a metabolic intermediate that constitutes 70% of ketone bodies produced during ketosis. Although ketosis has been generally considered as an unfavorable pathological state (e.g., diabetic ketoacidosis in type-1 diabetes mellitus), it has been suggested that induction of mild hyperketonemia may have certain therapeutic benefits. β-OHB is synthesized in the liver from acetyl-CoA by β-OHB dehydrogenase and can be used as alternative energy source. Elevated levels of PHB are associated with pathological states. In humans, short-chain, complexed PHB (cPHB) is found in a wide variety of tissues and in atherosclerotic plaques. Plasma cPHB concentrations correlate strongly with atherogenic lipid profiles, and PHB tissue levels are elevated in type-1 diabetic animals. However, little is known about mechanisms of PHB action especially in the heart. In contrast to β-OHB, PHB is a water-insoluble, amphiphilic polymer that has high intrinsic viscosity and salt-solvating properties. cPHB can form non-specific ion channels in planar lipid bilayers and liposomes. PHB can form complexes with polyP and Ca2+ which increases membrane permeability. The biological roles played by polyP, a ubiquitous phosphate polymer with ATP-like bonds, have been most extensively studied in prokaryotes, however polyP has recently been linked to a variety of functions in mammalian cells, including blood coagulation, regulation of enzyme activity in cancer cells, cell proliferation, apoptosis and mitochondrial ion transport and energy metabolism. Recent evidence suggests that polyP is a potent activator of the mitochondrial permeability transition pore in cardiomyocytes and may represent a hitherto unrecognized key structural and functional component of the mitochondrial membrane system.

Galactose-Alpha-1,3-Galactose, Mammalian Meat and Anaphylaxis: A World-Wide Phenomenon?

Mammalian meat allergy following tick bites is known to occur in Australia, North America, Europe, Asia, Africa and Central America. Over the last decade, the condition has become increasingly prevalent in tick-endemic areas of Australia and the USA. In mammalian meat-allergic individuals, gelatine allergy and/or cow’s milk allergy may co-exist. Awareness of tick-induced allergies in health professionals and the general community is key to both a timely diagnosis and the prevention of mammalian meat allergy. Treatment of mammalian meat allergy is limited currently to avoidance of all mammalian meat, whilst gelatine allergy similarly mandates avoidance of mammalian-derived gelatine, especially intravenously administered gelatine-containing solutions. Adults with anaphylaxis to mammalian meat should have a convalescent tryptase estimation and investigations for mastocytosis should then be undertaken if the tryptase is significantly elevated. Before initiating treatment with certain therapeutic agents (e.g. cetuximab, gelatine-containing substances, bovine artificial blood), a careful assessment of the risk of anaphylaxis, including serological analysis for galactose-alpha-1,3-galactose-specific immunoglobulin E, should be undertaken in any individual who works, lives, volunteers or participates in leisure activities in a tick-endemic area, particularly where a history is obtained of a tick bite prior, or of mammalian meat or gelatine allergy. Strategies aimed at the prevention of tick bites are paramount for primary prevention and amelioration of mammalian meat allergy. Key points 1. Mammalian meat allergies are characterised by delayed anaphylaxis, urticaria and angioedema, occurring 2–10 h after the ingestion of mammalian meat and are commonly preceded by a tick bite. 2. Mammalian meat allergy may be confirmed by galactose-alpha-1,3-galactose and mammalian meat-specific immunoglobulin E estimations, cetuximab skin testing or skin prick testing with fresh, raw, organic meat extracts. 3. Confirmation of gelatine allergy requires intradermal testing if skin prick testing is negative and gelatine-specific immunoglobulin E is not detected. 4. Dietary exclusion of mammalian meat, mammalian gelatine and cow’s milk products, as indicated by the individual clinical sensitivity profile, is the mainstay of treatment in allergy to galactose-alpha-1,3-galactose. 5. Mammalian meat-allergic patients should be aware of the risk of allergic reaction to cetuximab, gelatine and mammalian meat-containing therapeutic agents and health supplements and to check the ingredients carefully. 6. Search for co-existing mastocytosis when tryptase levels are elevated in convalescence. 7. Prevention of tick bites appears to limit the duration of the condition in some individuals and is essential to the primary prevention of mammalian meat allergy.

A novel method for detecting dietary (and other) toxicities: quantifying the adverse effects of added sugar consumption (814.8)

The ultimate function of an organism’s physiology is the performance of complex behaviors that facilitate reproduction. Here we use Organismal Performance Assays (OPAs) to quantify declines in Darwinian fitness of house mice due to experimental exposures. OPAs are sensitive phenotyping approaches that use semi‐natural conditions to challenge the physiology of differentially treated animals in direct competition with each other. Using OPAs we demonstrated that consumption of human‐relevant levels of added sugar (25% kcal) decreases reproduction of male mice by 25% while doubling the mortality rate of females relative to starch‐fed controls. Furthermore, we showed that many clinical measures associated with proximate effects of added sugar consumption were not predictive of organismal‐level effects. We expand upon these studies by using OPAs to test for differential health consequences of the two most common forms of added sugar. We report that females fed a diet containing an equal ratio of fructose and glucose monosaccharides (modeling high fructose corn syrup; HFCS) experienced a mortality rate 1.9 times higher and produced 26% fewer offspring than those fed sucrose (fructose‐glucose disaccharide). This experiment provides evidence that fructose and glucose monosaccharides (HFCS) are more deleterious to mammalian health than isocaloric sucrose.Grant Funding Source: Supported by NIH and NSF

Humpback Whale Populations Share a Core Skin Bacterial Community: Towards a Health Index for Marine Mammals?

Microbes are now well regarded for their important role in mammalian health. The microbiology of skin – a unique interface between the host and environment - is a major research focus in human health and skin disorders, but is less explored in other mammals. Here, we report on a cross-population study of the skin-associated bacterial community of humpback whales (Megaptera novaeangliae), and examine the potential for a core bacterial community and its variability with host (endogenous) or geographic/environmental (exogenous) specific factors. Skin biopsies or freshly sloughed skin from 56 individuals were sampled from populations in the North Atlantic, North Pacific and South Pacific oceans and bacteria were characterized using 454 pyrosequencing of SSU rRNA genes. Phylogenetic and statistical analyses revealed the ubiquity and abundance of bacteria belonging to the Flavobacteria genus Tenacibaculum and the Gammaproteobacteria genus Psychrobacter across the whale populations. Scanning electron microscopy of skin indicated that microbial cells colonize the skin surface. Despite the ubiquity of Tenacibaculum and Psychrobater spp., the relative composition of the skin-bacterial community differed significantly by geographic area as well as metabolic state of the animals (feeding versus starving during migration and breeding), suggesting that both exogenous and endogenous factors may play a role in influencing the skin-bacteria. Further, characteristics of the skin bacterial community from these free-swimming individuals were assembled and compared to two entangled and three dead individuals, revealing a decrease in the central or core bacterial community members (Tenacibaculum and Psychrobater spp.), as well as the emergence of potential pathogens in the latter cases. This is the first discovery of a cross-population, shared skin bacterial community. This research suggests that the skin bacteria may be connected to humpback health and immunity and could possibly serve as a useful index for health and skin disorder monitoring of threatened and endangered marine mammals.

Comparison of separation techniques for the elucidation of IgG N-glycans pooled from healthy mammalian species

The IgG N-glycome provides sufficient complexity and information content to serve as an excellent source for biomarker discovery in mammalian health. Since oligosaccharides play a significant role in many biological processes it is very important to understand their structure. The glycosylation is cell type specific as well as highly variable depending on the species producing the IgG. We evaluated the variation of N-linked glycosylation of human, bovine, ovine, equine, canine and feline IgG using three orthogonal glycan separation techniques: hydrophilic interaction liquid chromatography (HILIC)–UPLC, reversed phase (RP)–UPLC and capillary electrophoresis with laser induced fluorescence detection (CE-LIF). The separation of the glycans by these high resolution methods yielded different profiles due to diverse chemistries. However, the % abundance of structures obtained by CE-LIF and HILIC–UPLC were similar, whereas the analysis by RP-UPLC was difficult to compare as the structures were separated by classes of glycans (highly mannosylated, fucosylated, bisected, fucosylated and bisected) resulting in the co-elution of many structures. The IgGs from various species were selected due to the complexity and variation in their N-glycan composition thereby highlighting the complementarity of these separation techniques.

IMPACT OF SELENIUM FERTILIZATION ON GLUCOSINOLATE CONCENTRATION IN ARABIDOPSIS THALIANA AND RAPID CYCLING BRASSICA OLERACEA

Brassica vegetables are a significant source of glucosinolates (GSs), which are sulfur (S)-containing phytonutrients exhibiting, upon hydrolysis by endogenous myrosinase, antioxidant and anti-carcinogenic activity. Selenium (Se) is an essential micronutrient in mammalian health exhibiting antioxidant activity by inhibiting experimental carcinogenesis in animal models and reducing cancer incidence in human clinical trials. Selenium is readily accumulated in both Brassica species and Arabidopsis thaliana, a model species with similar S-metabolism. The research objectives for this project were to: 1) compare the impact of Se fertilization on GS concentrations between Arabidopsis thaliana and rapid cycling Brassica oleracea; and 2) determine the level of Se fertilization needed to optimize plant tissue Se concentration to maximize potential human health benefits. Both S and Se concentrations increased in A. thaliana and B. oleracea tissues in response to increasing Se treatments. Concentrations of glucoiberin, glucoraphanin, aliphatic, and total GS differed significantly between A. thaliana and B. oleracea. Data demonstrates that anti-carcinogenic GSs can be modified through changes in Se treatment concentrations, yet high levels of anti-carcinogenic GSs can be maintained while increasing Se concentration to 0.8 mg Se L-1. Thus, it is feasible to increase Se to beneficial dietary levels without compromising GS concentrations.

Trends in the Field of Mammalian Social Behavior and Health Over the Last 20 Years

In any scientific field there are thematic changes over time as new technologies and methods of investigation are developed and accumulated knowledge drives new research directions. The current study examines how themes in the investigation of social behavior and health have changed over the last 20 years. Literature searches were performed to identify articles published between 1993-2012 that investigate the intersection between social behavior and health in mammals. Results identify the top journals that publish articles in this field and describe trends in how sub-divisions in social behavior (e.g. aggression or dominance) and health (e.g. immunity or brain chemicals) have changed over the last 20 years. Our results suggest a dramatic increase in publications on the intersection between social behavior and health over this time span. Major categories of study include relationships between general social behavior or social stress and health outcomes relating to stress responses, endocrinology, and the brain.