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  Partner: UNT Libraries
 Resource Type: Thesis or Dissertation
 Degree Discipline: Biology
Maturation of Endothermic Capacity within the Avian Developmental Spectrum: A Characterization of Thermoregulatory Metamorphosis

Maturation of Endothermic Capacity within the Avian Developmental Spectrum: A Characterization of Thermoregulatory Metamorphosis

Date: August 2016
Creator: Sirsat, Sarah Goy
Description: An avian embryo is ectothermic, with body temperature determined by environmental temperature. Upon hatching, the neonate begins a conversion so that endothermic capacity becomes feasible and body temperature becomes independent of environment. Whole animal metabolic rate and ventilation response, cardiovascular development, and maturation of muscle mitochondrial flux were the focus of this dissertation because of the direct role in shivering thermogenesis. Precocial ducks and altricial Double-crested Cormorants exhibit increasing hematocrit and disproportionate increases in fractional heart mass resulting in greater oxygen delivery capacity and increased capacity of muscles to utilize oxygen compared with ectothermic American Alligator and Common Snapping turtles. By selecting for faster growth and higher meat yield in the domestic chicken, differences in whole-animal, tissue, cellular, and regulatory responses are evident between broiler and layer type birds. In the altricial red-winged blackbird, despite appearance of a whole animal endothermic response sometime after 7 dph, capacity of skeletal muscles involved in shivering thermogenesis peaks prior to that time. Thus, full development of endothermy is delayed in this species, allowing the altricial nestling to allocate energy towards growth rather than metabolic maintenance. Hypothyroidism in neonate red-winged blackbirds results in delayed maturation of the cardiovascular system and mitochondrial oxidative capacity of ...
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Respiratory Responses in the Freshwater Snail (Pomacea Bridgesii) are Differently Affected by Temperature , Body Mass,and Oxygen Avalability

Respiratory Responses in the Freshwater Snail (Pomacea Bridgesii) are Differently Affected by Temperature , Body Mass,and Oxygen Avalability

Date: August 2016
Creator: Frifer, Wenasa Salem
Description: Pomacea bridgesii is a snail species native to tropical and sub-tropical regions, where it usually faces variability in water, temperature and oxygen level. This study of the effect of temperature on mass-specific oxygen consumption (ṀO2) and its relation to body weight shows that the ṀO2 of juvenile snails in normoxia (18-21 kPa) acclimated at temperature of 25°C ranged from 5 to 58 µMol O2/g/h, with a mean of 41.4 ± 18.3 µMol O2/g/h (n=7). Adult snails in normoxia at 25°C show less variation, ranging from 13 to 23 µMol O2/g/h , with a mean of 24.4± 6.1 µMol O2/g/h (n=12). The Q10 value for juvenile snails was higher in the interval 25-30°C (Q 10=5.74) than in the interval 20-25°C (Q10= 0.286). In adult snails, Q10 was higher in the interval 20-25°C (Q10=3.19). ṀO2 of P. bridgesii in relation to body weight showed a negative linear correlation between metabolic rate and body weight with b values between 0.23 and 0.76. Also, both juvenile and adult snails exhibited weak O2 regulation. In general, the different respiratory characteristics between juvenile and adult snails might be related to the differences of individual life history, which caused them to perform differently in face of temperatures ...
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Glucose and Altered Ceramide Biosynthesis Impact the Transcriptome and the Lipidome of Caenorhabditis elegans

Glucose and Altered Ceramide Biosynthesis Impact the Transcriptome and the Lipidome of Caenorhabditis elegans

Date: August 2016
Creator: Ladage, Mary Lee
Description: The worldwide rise of diabetes and obesity has spurred research investigating the molecular mechanisms that mediate the deleterious effects associated with these diseases. Individuals with diabetes and/or obesity are at increased risk from a variety of health consequences, including heart attack, stroke and peripheral vascular disease; all of these complications have oxygen deprivation as the central component of their pathology. The nematode Caenorhabditis elegans has been established as a model system for understanding the genetic and molecular regulation of oxygen deprivation response, and in recent years methods have been developed to study the effects of excess glucose and altered lipid homeostasis. Using C. elegans, I investigated transcriptomic profiles of wild-type and hyl-2(tm2031) ( a ceramide biosynthesis mutant) animals fed a standard or a glucose supplemented diet. I then completed a pilot RNAi screen of differentially regulated genes and found that genes involved in the endobiotic detoxification pathway (ugt-63 and cyp-25A1) modulate anoxia response. I then used a lipidomic approach to determine whether glucose feeding or mutations in the ceramide biosynthesis pathway or the insulin-like signaling pathway impact lipid profiles. I found that gluocose alters the lipid profile of daf-2(e1370) (an insulin-like receptor mutant) animals. These studies indicate that a transcriptomic ...
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The Effect of Post-exercise Ethanol Consumption on the Acute Hormonal Response to Heavy Resistance Exercise in Women

The Effect of Post-exercise Ethanol Consumption on the Acute Hormonal Response to Heavy Resistance Exercise in Women

Date: December 2015
Creator: Budnar, Jr., Ronald G.
Description: The purpose of this study was to examine the hormonal response to acute ethanol ingestion following a bout of heavy resistance exercise in women. Eight resistance trained women completed two identical acute heavy resistance exercise tasks (AHRET). From 10-20 minutes post-AHRET, participants consumed either a grain ethanol or a placebo beverage. Blood was collected before (PRE) and immediately after the AHRET (IP) and then every 20 minutes for five hours. Blood collected after beverage ingestion was pooled into 3 batches (phases: 20-40 minutes, 60-120 minutes, and 140-300 minutes post-exercise) and analyzed for serum total testosterone (TT), free testosterone (FT), insulin-like growth factor-I (IGF-I), human growth hormone (GH), cortisol (COR), and estradiol (E2) concentrations. Circulating concentrations of TT were significantly greater at P20-40 than at PRE, P60-120, and P140-300. Circulating concentrations of FT were significantly greater at P20-40 than at all other times. Circulating concentrations of GH were significantly greater at IP than at PRE, P60-120, and P140-300. Circulating concentrations of COR were significantly greater at P20-40 than at all other times. Additionally, COR concentrations at P140-300 were significantly lower than at all other times. Circulating concentrations of IGF-1 were significantly greater at P20-40 than at P60-120 and P140-300. Circulating concentrations ...
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A High-fat Meal Alters Post-prandial Mrna Expression of Sirt1, Sirt4, and Sirt6

A High-fat Meal Alters Post-prandial Mrna Expression of Sirt1, Sirt4, and Sirt6

Date: December 2015
Creator: Best Sampson, Jill Nicole
Description: Sirtuins (SIRT) regulate the transcription of various genes involved in the development of diet-induced obesity and chronic disease; however, it is unknown how they change acutely following a high-fat meal. The purpose of this study was to determine the effect of a high-fat meal (65% kcals/d; 85% fat recommendation), on SIRT1-7 mRNA expression in blood leukocytes at 1, 3, and 5-h post-prandial. Men and women (N=24) reported to the lab following an overnight fast (>12H). Total RNA was isolated and reverse transcribed prior to using a Taqman qPCR technique with 18S rRNA as a normalizer to determine SIRT1-7 mRNA expression. An additional aliquot of serum was used to measure triglycerides. Data was analyzed using a RM ANOVA with P<0.05. Triglycerides (P<0.001; 124%) peaked at 3-h. SIRT 1 (P=0.004; 70%), and SIRT 6 (P=0.017; 53%) decreased expression at 3-h. SIRT4 (P=0.024) peaked at 5H relative to baseline (70%) and 3-h (68%). To our knowledge, this is the first study to report that consumption of a high-fat meal transiently alters SIRT mRNA expression consistent in a pattern that mirrors changes in serum triglycerides. Decrease in expression of SIRT1 and SIRT6 combined with an increased SIRT4 would be consistent with an increase in ...
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Phenotypic Morphological Plasticity Induced by Environmental Salt Stress in the Brine Shrimp, Artemia Franciscana

Phenotypic Morphological Plasticity Induced by Environmental Salt Stress in the Brine Shrimp, Artemia Franciscana

Date: December 2015
Creator: Jones, Shaun Gray
Description: Phenotypic plasticity is the ability of an organism to express different phenotypes in response to biotic or abiotic environmental cues. The ability of an organism to make changes during development to adjust to changes in its environment is a key to survival. Sexually reproducing organisms that have short life cycles and that are easy to raise in the laboratory are more conducive for developmental phenotypic plasticity. Considerable research has already been carried out on the brine shrimp, Artemia franciscana, regarding its morphology due to changing salinities. There is, however, little research considering subsequent generations and how there morphology might be affected by parental experiences. This study has examined: 1) the morphological effects of different rearing regimes of different salinity levels, and 2) the epigenetic transgenerational transfer of these morphological traits in A. franciscana. Measurements included rate of growth (as measured by instar), body size, body length, and other morphological traits. A gradual increase to more hyperosmotic conditions during development produced brine shrimp that were larger in size and also more developmentally advanced. Salinity stress experienced by adults had increased the growth rate in the F1 offspring of A. franciscana. Collectively, these data indicate that Artemia franciscana is a tractable model ...
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The Role of Cysteinyl Leukotriene Receptor 2 in Thrombocyte Aggregation

The Role of Cysteinyl Leukotriene Receptor 2 in Thrombocyte Aggregation

Date: December 2015
Creator: Reyna, Julianna
Description: Cysteinyl leukotriene receptor 2, a G-protein coupled receptor known to be expressed and functional on human platelets. However, it seems that upon ligand activation the cysteinyl leukotriene receptor 2 activates a variety of signaling pathways in multiple cell types among different species. Previously, a former laboratory member Vrinda Kulkarni found cysteinyl leukotriene receptor 2 to be expressed on the surface of adult zebrafish thrombocytes. In this work I studied the characteristics of aggregation in adult zebrafish thrombocytes with the knockdown of cysteinyl leukotriene receptor 2. I used a newly developed knockdown method to study the function of cysteinyl leukotriene receptor 2. Knockdown of the cysteinyl leukotriene was confirmed using RT-PCR results showed p=.001, reduced sell surface level of expression of the cysteinyl leukotriene receptor 2 results showed that p=.002. I found that the knockdown of cysteinyl leukotriene receptor 2 results in prothrombotic thrombocytes by using flow cytometry p=.0001.
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Environmental Modulation of the Onset of Air-breathing of the Siamese Fighting Fish and the Blue Gourami

Environmental Modulation of the Onset of Air-breathing of the Siamese Fighting Fish and the Blue Gourami

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Date: December 2015
Creator: Mendez Sanchez, Jose Fernando
Description: This study determined the effect of hypoxia on air-breathing onset and physiological and morphological characters in larvae of the air breathing fishes Trichopodus trichopterus and Betta splendens. Larvae were exposed intermittently (12/12 h daily) to 20, 17, and 14 kPa of PO2 from 1 to 40 days post-fertilization. Survival, onset of air breathing, wet body mass, O2, Pcrit were measured every 5 dpf. Hypoxia advanced by 4 days, and delayed by 9 days, the onset of air breathing in Betta and Trichopodus, respectively. Hypoxia increased larval body length, wet mass, and labyrinth organ respiratory surface of Betta, but did not affect these factors in Trichopodus. Hypoxic exposure increased O2 by 50-100% at each day throughout larval development in Betta, but had no effect on larval Trichopodus. Hypoxia decreased Pcrit in Betta by 37%, but increased Pcrit in Trichopodus by 70%. Larval Betta reared in hypoxia showed a modified heart rate:opercular rate ratio (3:1 to 2:1), but these changes did not occur in Trichopodus. Compared to Betta, the blood of Trichopodus had a higher P50 and much smaller Bohr and Root effects. These interspecific differences are likely due to ecophysiological differences: Betta is a non- obligatory air-breather after 36 dpf with ...
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Characterizing the Molecular Changes of Austrofundulus Limnaeus As It Develops Towards and Enters Diapause Ii

Characterizing the Molecular Changes of Austrofundulus Limnaeus As It Develops Towards and Enters Diapause Ii

Date: December 2015
Creator: Toni, Lee S.
Description: Austrofundulus limnaeus is a species of annual killifish which inhabits ephemeral ponds in South America. The species is able to survive seasonally desiccating ponds due to their ability to produce robust embryos. The embryos of this species are capable of entering a developmental arrest, termed diapause II, which precedes the onset of drought. While in this arrested state embryos exhibit the greatest tolerance to anoxia of any characterized vertebrate at 25ºC. Furthermore, when raised at 30ºC, embryos escape the entrance to diapause II and go on to develop directly. Currently, little is known about the molecular mechanisms which induce and maintain this developmentally arrested state. In this study I have developed methods to analyze changes in histone modifications in the context of diapause II. Histone modifications were chosen due to their extreme conservation and well characterized role as modulators of gene expression in other systems. Results utilizing adapted immunobased assays show significant changes in the global amount of H3S10P, H3K27me and H3K4me, as the embryos progress from early embryogenesis through the exit of diapause. Additionally, it is revealed that there exists a degree of phenotypic plasticity with regards to the entrance into diapause II which is modulated by the environment ...
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Impact of a Genetically Engineered Probiotic Therapy and Igf-1 Genomics in the Pahenu2 Mouse Model of Pku

Impact of a Genetically Engineered Probiotic Therapy and Igf-1 Genomics in the Pahenu2 Mouse Model of Pku

Date: December 2015
Creator: Durrer, Katherine Elaine
Description: Absence of functional phenylalanine hydroxylase results in phenylketonuria (PKU). Viable treatments remain few, expensive and secondary conditions such as osteopenia occur in most PKU patients. Objective 1: Given the recently described roles of gut microbes to aid host digestion, an orally administered genetically engineered probiotic as the delivery vehicle for enzyme replacement therapy was created. The engineered probiotic, pHENOMMenal, produced phenylalanine ammonia lyase with significant production of trans-cinnamate (phenylalanine cleavage product) in vitro and resulted in a reduction of 515 μM in blood phenylalanine when fed to PKU animals for 14 days (from 2307µM ± 264µM to 1792µM ± 261µM, n = 6, P < 0.05). The control probiotic produced no change in blood phenylalanine. Thus, pHENOMMenal treatment in PKU mice demonstrated engineered microbes could compensate for a metabolic deficiency of the host. Objective 2: Evaluate the PAHenu2 mouse model of PKU for a genetic discrepancy causing ocular enlargement and delayed development observed only after the PAHenu2 mutation was crossed to the C57BL/6J mouse. When compared to healthy littermates, ELISA indicated a consistent but insignificant decrease in plasma IGF-1 and an increase in ocular IGF-1 in PKU animals. SNP screening demonstrated a differential inheritance of IGF-1 alleles in healthy and ...
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Thresholds and Legacy Effects of Tropical Floodplain Fish Assemblages in Response to Flood Attributes

Thresholds and Legacy Effects of Tropical Floodplain Fish Assemblages in Response to Flood Attributes

Date: December 2015
Creator: Hoeinghaus, Ana Paula Ferrari
Description: Natural flow regimes are critical for sustaining biodiversity and river integrity. Floods and droughts form an important component of river systems and control population sizes and species diversity across space and time. Modification of flow regimes, including disruption of the timing, magnitude and duration of flooding, is a global problem, and many new impoundments are planned for large river-floodplain ecosystems in the tropics. Flow modifications may cause dramatic non-linear responses in population sizes and have lasting effects through time, but such topics are poorly investigated over multi-year scales, especially in highly diverse tropical ecosystems. Using a long-term dataset from the Upper Paraná River floodplain, Brazil, I tested for threshold and legacy effects of fish assemblages to flood attributes, such as timing, magnitude, duration, rate of change and variation. Specifically, I hypothesized that long duration, high magnitude floods would elicit threshold responses in long-distance migratory fish species and these responses result in significant legacy effects detectable over multiple years. Consistent positive threshold responses to increasing flood duration and magnitude were detected for many species and not significantly correlated with reproductive guilds. Legacy effects were prevalent (i.e. identified for more than 90% of species) and including flood attributes from previous years increased ...
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Glucose Induces Sensitivity to Oxygen Deprivation and Alters Gene Expression in Caenorhabditis Elegans

Glucose Induces Sensitivity to Oxygen Deprivation and Alters Gene Expression in Caenorhabditis Elegans

Date: August 2015
Creator: Garcia, Anastacia M.
Description: An organisms’ diet represents an exogenous influence that often yields colossal effects on long-term health and disease risk. The overconsumption of dietary sugars for example, has contributed to significant increases in obesity and type-2 diabetes; health issues that are costly both economically and in terms of human life. Individuals who are obese or are type-2 diabetic often have compromised oxygen delivery and an increased vulnerability to oxygen-deprivation related complications, such as ischemic strokes, peripheral arterial disease and myocardial infarction. Thus, it is of interest to identify the molecular changes glucose supplementation or hyperglycemia can induce, which ultimately compromise oxygen deprivation responses. By utilizing the Caenorhabditis elegans genetic model system, which is anoxia tolerant, I determined that a glucose-supplemented diet negatively impacts responses to anoxia and that the insulin-like signaling pathway, through fatty acid and ceramide biosynthesis and antioxidant activity, modulates anoxia survival. Additionally, a glucose-supplemented diet induces lipid accumulation. Use of RNA-sequencing analysis to compare gene expression responses in animals fed either a standard or glucose-supplemented diet revealed that glucose impacts the expression of genes involved with multiple cellular processes including lipid and carbohydrate metabolism, stress responses, cell division, and extracellular functions. Several of the genes we identified are homologous ...
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Effect of Acute Alcohol Ingestion on Resistance Exercise Induced Mtorc1 Signaling in Human Muscle

Effect of Acute Alcohol Ingestion on Resistance Exercise Induced Mtorc1 Signaling in Human Muscle

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Date: August 2015
Creator: Anthony A. Duplanty
Description: The purpose of this project was to further elucidate the effects post-exercise alcohol ingestion. This project had many novel aspects including using a resistance exercise (RE) only exercise design and the inclusion of women. To our knowledge, we are the first to investigate the effect of post-RE alcohol ingestion in women. In the first chapter of this project, information on the prevalence of alcohol use and the importance of skeletal muscle as a dynamic and metabolic tissue was provided. In chapter two, the effects of post-RE alcohol ingestion in men and women are detailed. The major findings of this study was that although RE elicited similar mTORC1 signaling both in men and in women, alcohol ingestion appeared to only attenuate RE-induced phosphorylation of the mTORC1 signaling pathway in men. The third chapter focused on examining the effects of post-RE alcohol ingestion on acute testosterone bioavailability. The primary findings of this study was that alcohol substantially elevated serum total and free testosterone concentrations during recovery from a bout of resistance exercise. The fourth chapter detailed factors that contribute to bone density in men. The major findings of this study was that young adult male long-distance runners who participated in resistance training ...
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Cytotoxicity and Functional Toxicity of Mefloquine and Search for Protective Compounds

Cytotoxicity and Functional Toxicity of Mefloquine and Search for Protective Compounds

Date: May 2015
Creator: Holmes, Katelyn
Description: Mefloquine hydrochloride is an antimalarial agent that has been used for the past 40 years. Numerous reports of neurological side effects have recently led the FDA to issue a strong warning regarding long-term neurological effects. This warning lead to the U.S. Army’s Special Forces and other components to discontinue its use in July of 2013. Despite reported adverse side effects, mefloquine remains in circulation and is recommended to travelers going to specific Asian countries. Mefloquine has been used as a treatment for those already infected with the malaria parasite (blood concentrations ranging from 2.1 to 23 µM), and as prophylaxis (blood concentrations averaging 3.8 µM) (Dow 2003). The purpose of this study was to quantify Mefloquine’s toxicity using spontaneously active nerve cell networks growing on microelectrode arrays in vitro and to identify compounds that alleviate or reduce toxic effects. The current literature on mefloquine toxicity is lacking electrophysiological data. These data will contribute to research on the mechanism of adverse side effects associated with mefloquine use. Sequential titration experiments were performed by adding increasing concentrations of mefloquine solution to cultured neurons. Network responses were quantified and reversibility was examined. In each network, activity decreases were normalized as a percent of ...
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Understanding Microbial Biodegradation of Environmental Contaminants

Understanding Microbial Biodegradation of Environmental Contaminants

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Date: May 2015
Creator: Vilo Muñoz, Claudia Andrea
Description: The accumulation of industrial contaminants in the natural environments have rapidly become a serious threat for human and animal life. Fortunately, there are microorganisms capable of degrading or transforming environmental contaminants. The present dissertation work aimed to understand the genomic basis of microbial degradation and resistance. The focus was the genomic study of the following bacteria: a) Pseudomonas fluorescens NCIMB 11764, a unique bacterium with specific enzymes that allow cyanide adaptation features. Potential cyanide degradation mechanisms found in this strain included nit1C cluster, and CNO complex. Potential cyanide tolerance genes found included cyanide insensitive oxidases, nitric oxide producing gene, and iron metabolism genes. b) Cupriavidus sp. strain SK-3 and strain SK-4. The genome of both bacteria presented the bph operon for polychlorinated biphenyl (PCB) degradation, but we found differences in the sequences of the genes. Those differences might indicate their preferences for different PCB substrates. c) Arsenic resistant bacterial communities observed in the Atacama Desert. Specific bacteria were found to thrive depending on the arsenic concentration. Examples were Bacteroidetes and Spirochaetes phyla whose proportions increased in the river with high arsenic concentrations. Also, DNA repair and replication metabolic functions seem to be necessary for resistance to arsenic contaminated environments. Our ...
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The Effect of Curcumin Supplementation on Physical and Biological Indices of Delayed Onset Muscle Soreness and Inflammation Following Muscle Injury

The Effect of Curcumin Supplementation on Physical and Biological Indices of Delayed Onset Muscle Soreness and Inflammation Following Muscle Injury

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Date: May 2015
Creator: Venable, Adam Steven
Description: In this project, the effects of dietary polyphenols on exercise-induced muscle damage and vascular health are examined. Dietary polyphenols exert well-known anti-inflammatory effects; however, how these effects are realized with respect to vascular health and EIMD is relatively unknown. I begin by reviewing the available literature surrounding the impact of three dietary polyphenols (curcumin, catechins, and quercetin) on inflammation associated with EIMD. It is well established that their primary means of anti-inflammation is through alterations of NF-κB and AP-1 transcription activities. Given this, their inclusion into training strategies seems reasonable. Consistent evidence is presented making a case for the anti-inflammatory effects of dietary polyphenols following EIMD. I follow this review up by completing an in-depth study on the consumption of curcumin prior to EIMD. I found curcumin (1000 mg/day) can reduce subjective soreness and decrease inflammation compared to placebo controls. To further understand the effects of dietary polyphenols on health, I investigate the effects of a four-week supplementation period of cocoa (catechins) on vascular. I concluded that atherogenic risk in obese women is reduced after consumption of cocoa. In addition to these experimental projects, I developed two novel methods that can be used to investigate vascular health (EMP concentration) and ...
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Characteristics of Primary Cilia and Centrosomes in Neuronal and Glial Lineages of the Adult Brain

Characteristics of Primary Cilia and Centrosomes in Neuronal and Glial Lineages of the Adult Brain

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Date: May 2015
Creator: Bhattarai, Samip Ram
Description: Primary cilia are sensory organelles that are important for initiating cell division in the brain, especially through sonic hedgehog (Shh) signaling. Several lines of evidence suggest that the mitogenic effect of Shh requires primary cilia. Proliferation initiated by Shh signaling plays key roles in brain development, in neurogenesis in the adult hippocampus, and in the generation of glial cells in response to cortical injury. In spite of the likely involvement of cilia in these events, little is known about their characteristics. Centrosomes, which are associated with primary cilia, also have multiple influences on the cell cycle, and they are important in assembling microtubules for the maintenance of the cell’s cytoskeleton and cilia. The cilia of terminally differentiated neurons have been previously examined with respect to length, incidence, and receptors present. However, almost nothing is known about primary cilia in stem cells, progenitors, or differentiated glial cells. Moreover, it is not known how the properties of cilia and centrosomes may vary with cell cycle or proliferative potential, in brain or other tissues. This dissertation focuses first on neurogenesis in the hippocampal subgranular zone (SGZ). The SGZ is one of the few brain regions in mammals that gives rise to a substantial ...
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Improving Processing Efficiency for Forensic DNA Samples

Improving Processing Efficiency for Forensic DNA Samples

Date: May 2015
Creator: Connon, Catherine Cupples
Description: The goal of this project was to reduce processing time for forensic DNA testing without incurring significant added costs and/or the need for new instrumentation, while still generating high quality profiles. This was accomplished by: 1) extraction normalization using the ChargeSwitch® Forensic DNA Purification Kit such that a small range of DNA concentrations was consistently obtained, eliminating the need for sample quantification and dilution; 2) developing fast PCR protocols for STR primer sets using shorter amplification methods, low volume reactions and non-fast thermal cyclers; and 3) developing a quicker 3130xl Genetic Analyzer detection method using an alternative polymer/array length combination. Extraction normalization was achieved through a reduction in bead quantity, thereby forcing an increase in bead binding efficiency. Four products (AmpliTaq Gold® Fast PCR Master Mix, KAPA2G™ Fast Multiplex PCR Kit, SpeedSTAR™ HS DNA Polymerase and Type-it Microsatellite PCR Kit) were evaluated for low volume (3μl) fast PCR on a 384-well Veriti® thermal cycler with the Identifiler primer set. KAPA2G™ was selected for 3μl fast PCR protocols using PowerPlex 16 HS and Identifiler Plus primer sets (42-51min), as well as 5μl and 6μl Identifiler fast reactions on a 9700 thermal cycler (51-60min). Alternative detection (POP-6™/22cm) achieved 24-28min run times, but ...
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Neurotoxicity of the Industrial Solvent 4-Methylcyclohexanemethanol: Involvement of the GABA Receptor

Neurotoxicity of the Industrial Solvent 4-Methylcyclohexanemethanol: Involvement of the GABA Receptor

Date: May 2015
Creator: Gibson, Jason
Description: A recent chemical spill of 4-Methylcyclohexanemethanol (4-MCHM) in West Virginia left 300,000 people without water. Officials claimed that this compound is not lethally toxic, but potentially harmful if swallowed or inhaled, and can cause eye and skin irritation. Sittig's Handbook of Toxic and Hazardous Chemical Carcinogens reports high exposures from skin contact or inhalation may cause damage to the heart, liver, kidneys, and lungs, and may result in death. However, no quantitative data seem to exist and no references can be found on neurotoxicity. We have investigated the neurotoxicity of 4-MCHM using mammalian nerve cell networks grown on microelectrode arrays. Network spontaneous activity from multiple units (range 48 – 120 per network) were used as the primary readout. Individual units were followed based on spike waveforms digitized at 40 kHz (Plexon MNAP system). Dose response curves show the effective inhibitory concentration at 50 percent decrease (EC50) to average 27.4 microM SD±6.17. However, in the presence of 40 microM bicuculline, a competitive GABAA antagonist, the EC50 shifts to 70.63uM SD ±4.3; implying that early, low concentration exposures to 4-MCHM involve GABA activation. Initial activity loss occurs without active unit loss (defined as 10 or more template threshold crossing per min), indicating ...
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Women Have Higher Skin Temperature on the Back during Treadmill Exercise in a Hot, Humid Environment

Women Have Higher Skin Temperature on the Back during Treadmill Exercise in a Hot, Humid Environment

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Date: August 2014
Creator: Venable, Adam Steven
Description: A common measurement of body temperature during exercise in a hot, humid environment is mean skin temperature collected from 3-12 sites on the body. However, such an approach fails to demonstrate localized differences in skin temperature that are likely to exist as a function of gender. The purpose of this study was to examine potential differences in skin temperature between men and women at 17 different locations on the body. Young women (21 ± 1 y; n = 11) and men (23 ± 3; n = 10) were recruited to complete a 60-min walk/jog interval protocol in a hot (34 ± 1 °C), humid (64 ± 8%) environment while skin temperature was measured. Data was analyzed using a repeated-measures ANOVA (p < 0.05) and location of interaction effects determined using a Fisher’s least squares difference test. We observed a higher change (p < 0.05) from baseline skin temperatures (ΔTsk) for women in three locations: left upper back (women: avg. ΔTsk = 4.12 ± 0.20 °C; men: avg. ΔTsk = 2.70 ± 0.10 °C), right upper back (women: avg. ΔTsk = 4.19 ± 0.07 °C; men: avg. ΔTsk = 2.92 ± 0.05 °C), and right mid-back (women: avg. ΔTsk = 4.62 ...
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The Impact of Developmental Stress on Cardiovascular Physiology of Two Archosaur Species: American Alligator (Alligator mississippiensis) and Domestic Chicken (Gallus gallus)

The Impact of Developmental Stress on Cardiovascular Physiology of Two Archosaur Species: American Alligator (Alligator mississippiensis) and Domestic Chicken (Gallus gallus)

Date: December 2014
Creator: Tate, Kevin B.
Description: Crocodilians and birds comprise sister taxa of archosaurs, the development of these vertebrates occurs within an egg case that leaves developing embryos susceptible to fluctuations in the nesting environment. Studies suggest that sub-optimal conditions alter morphological growth and cardiovascular physiology. Regulation of the cardiovascular system is immature in the subjects studied, and embryos may rely on humoral rather than neural control of the cardiovascular system. The primary focus of this dissertation was to assess regulatory mechanisms responsible for maintenance of arterial pressure and heart rate. Dehydration stress had marked effects on embryo growth, and altered baseline cardiovascular parameters, while leaving the response to humoral regulator, angiotensin II (Ang II), unaffected. However, dehydrated alligator embryos developed cholinergic tone on heart rate. Hypoxic incubated chicken embryos were reduced in embryo mass, and altered response to humoral regulatory components Ang I and adenosine in addition identifying a novel regulatory component of the cardiovascular response to acute hypoxia. Collectively, these studies add to the existing knowledge of cardiovascular physiology in embryonic archosaurs and suggest that some components of cardiovascular regulation are plastic following developmental stress.
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Monitoring Monocyte Oxldl Phagocytosis As a Cardiovascular Disease Risk Factor Following a High-fat Meal

Monitoring Monocyte Oxldl Phagocytosis As a Cardiovascular Disease Risk Factor Following a High-fat Meal

Date: December 2014
Creator: Henning, Andrea L.
Description: Macrophage-derived foam cells play a predominant role in the deposition of arterial plaques during the early stages of atherosclerosis. The deposition of arterial plaques is known to be effected by several factors, including a person’s dietary habits. The consumption of a high-fat (>60% of calories from fat) meal is known to elevate serum LDL and triglycerides, which have been previously implicated in the formation pf foam cells. One limitation of current research models is that it is not possible to directly measure foam cells in vivo. Thus, the purpose of the present study was to validate the use of blood derived monocytes as a proxy measure of foam cells. In order to complete this objective, we evaluated monocyte oxLDL phagocytosis capacity following consumption of a high-fat meal. Eight men and women participated in the present study and venous blood samples were collected prior to the meal, 1-h, 3-h, and 5-h post-meal. Monocytes (CD14+/16- and CD14+/16+) were evaluated for adhesion molecule expression (CD11a, CD11b, and CD18), scavenger R (CD36) expression, and oxLDL phagocytosis using an image-based flow cytometry method developed in our laboratory for this purpose. Data was statistically analyzed for significance using a single-factor ANOVA with repeated measures and a ...
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In Vitro Investigations of Antibiotic Influences on Nerve Cell Network Responses to Pharmacological Agents

In Vitro Investigations of Antibiotic Influences on Nerve Cell Network Responses to Pharmacological Agents

Date: December 2014
Creator: Sawant, Meera
Description: Neuronal networks, derived from mouse embryonic frontal cortex (FC) tissue grown on microelectrode arrays, were used to investigate effects of gentamicin pretreatment on pharmacological response to the L-type calcium channel blocker, verapamil. Gentamicin is a broad spectrum antibiotic used to control bacterial contamination in cell culture. The addition of gentamicin directly to medium affects the pharmacological and morphological properties of the cells in culture. A reproducible dose response curve to verapamil from untreated cultures was established and the mean EC50 was calculated to be 1.5 ± 0.5 μM (n=10). 40 μM bicuculline was added to some cell cultures to stabilize activity and verapamil dose response curves were performed in presence of bicuculline, EC50 1.4 ± 0.1 μM (n=9). Statistical analysis showed no significant difference in verapamil EC50s values obtained in presence of bicuculline and hence the data was combined and a standard verapamil EC50 was calculated as 1.4 ± 0.13 μM (n=19). This EC50 was then used to compare verapamil EC50s obtained from neuronal cell cultures with chronic and acute exposures to gentamicin. FC cultures (21- 38 days old) were found to be stable in presence of 2300 μM gentamicin. The recommended concentration of gentamicin for contamination control is 5uL ...
Contributing Partner: UNT Libraries
Measuring Biomarkers From Dried Blood Spots Utilizing Bead-based Multiplex Technology

Measuring Biomarkers From Dried Blood Spots Utilizing Bead-based Multiplex Technology

Date: December 2014
Creator: Prado, Eric A.
Description: Dried blood spots is an alternative method to collect blood samples from research subjects. However, little is known about how hemoglobin and hematocrit affect bead-based multiplex assay performance. The purpose of this study was to determine how bead-based multiplex assays perform when analyzing dried blood spot samples. A series of four experiments outline the study each with a specific purpose. A total of 167 subject samples were collected and 92 different biomarkers were measured. Median fluorescence intensity results show a positive correlation between filtered and non-filtered samples. Utilizing a smaller quantity of sample results in a positive correlation to a larger sample. Removal of hemoglobin from the dried blood spot sample does not increase detection or concentration of biomarkers. Of the 92 different biomarkers measured 56 were detectable in 100-75% of the attempted samples. We conclude that blood biomarkers can be detected using bead-based multiplex assays. In addition, it is possible to utilize a smaller quantity of sample while avoiding the use of the entire sample, and maintaining a correlation to the total sample. While our method of hemoglobin was efficient it also removed the biomarkers we wished to analyze. Thus, an alternative method is necessary to determine if removing ...
Contributing Partner: UNT Libraries
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