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Creating Mechanistic Ion Channel Models Using Genetic Algorithms, Jonathan Neal Hurst May 2006

Creating Mechanistic Ion Channel Models Using Genetic Algorithms, Jonathan Neal Hurst

Biology

Modeling ion channel function is often problematic, especially for channels that have not been physically characterized, because transitions between many conformational states cannot be directly observed. Myriad voltage clamp protocols have been developed to study these transitions, but model parameterization remains difficult because either all transitions must be culled from one protocol, or the data from multiple protocols must be non-redundantly combined. One solution to this problem is to use a genetic algorithm to create models that fit all desired voltage clamp data. This method has the distinct advantage of producing accurate ion channel models without manipulating the voltage clamp …

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Somato-Dendritic Morphology Predicts Physiology For Neurons That Contribute To Several Kinds Of Limb Movements, Ari Berkowitz, Gina L.C. Yosten, R. Mark Ballard May 2006

Somato-Dendritic Morphology Predicts Physiology For Neurons That Contribute To Several Kinds Of Limb Movements, Ari Berkowitz, Gina L.C. Yosten, R. Mark Ballard

Biological Sciences Faculty Research & Creative Works

It has been difficult to predict the behavioral roles of vertebrate CNS neurons based solely on their morphologies, especially for the neurons that control limb movements in adults. We examined the morphologies of spinal interneurons involved in limb movement control, using intracellular recording followed by Neurobiotin injection in the in vivo adult turtle spinal cord preparation. We report here the first description of a class of spinal interneurons whose somato-dendritic morphologies predict their robust activity during multiple forms of ipsilateral and contralateral fictive hindlimb scratching and fictive hindlimb withdrawal. These "transverse interneurons" or T cells have mediolaterally elongated soma and …

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Host-Parasite Relatedness In Wood Ducks: Patterns Of Kinship And Parasite Success, Charlotte Nielsen, Brad Semel, Paul Sherman, David Westneat, Patricia Parker May 2006

Host-Parasite Relatedness In Wood Ducks: Patterns Of Kinship And Parasite Success, Charlotte Nielsen, Brad Semel, Paul Sherman, David Westneat, Patricia Parker

Biology Department Faculty Works

We investigated the role of kinship in intraspecific nest parasitism of wood ducks (Aix sponsa). Among waterfowl, female philopatry creates the potential for female relatives to nest in proximity. Costs of intraspecific nest parasitism to host females may be reduced if parasites lay eggs with kin. However, previous observations of marked wood ducks indicated that females avoided parasitizing clutch mates or the female that incubated them. To further examine the role of kinship, we determined the genotypes of 27 host-parasite pairs at five microsatellite loci. Average relatedness between hosts and all females laying parasitic eggs was only 0.04 ± 0.03. …

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Unexpected Diversity And Complexity Of The Guerrero Negro Hypersaline Microbial Mat, Ruth E. Ley, J. Kirk Harris, Joshua Wilcox, John R. Spear, Scott R. Miller, Brad M. Bebout, Julia A. Maresca, Donald A. Bryant, Mithcell L. Sogin, Norman R. Pace May 2006

Unexpected Diversity And Complexity Of The Guerrero Negro Hypersaline Microbial Mat, Ruth E. Ley, J. Kirk Harris, Joshua Wilcox, John R. Spear, Scott R. Miller, Brad M. Bebout, Julia A. Maresca, Donald A. Bryant, Mithcell L. Sogin, Norman R. Pace

Biological Sciences Faculty Publications

We applied nucleic acid-based molecular methods, combined with estimates of biomass (ATP), pigments, and microelectrode measurements of chemical gradients, to map microbial diversity vertically on a millimeter scale in a hypersaline microbial mat from Guerrero Negro, Baja California Sur, Mexico. To identify the constituents of the mat, small-subunit rRNA genes were amplified by PCR from community genomic DNA extracted from layers, cloned, and sequenced. Bacteria dominated the mat and displayed unexpected and unprecedented diversity. The majority (1,336) of the 1,586 bacterial 16S rRNA sequences generated were unique, representing 752 species (>= 97% rRNA sequence identity) in 42 of the …

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What Use Is Half A Wing In The Ecology And Evolution Of Birds?, Kenneth P. Dial, Ross J. Randall, Terry R. Dial May 2006

What Use Is Half A Wing In The Ecology And Evolution Of Birds?, Kenneth P. Dial, Ross J. Randall, Terry R. Dial

Biological Sciences Faculty Publications

The use of incipient wings during ontogeny in living birds reveals not only the function of these developing forelimbs in growing birds’ survival but also the possible employment of protowings during transitional stages in the evolution of flight. When startled, juvenile galliform birds attempt aerial flight even though their wings are not fully developed. They also flap their incipient wings when they run up precipitous inclines, a behavior we have described as wing-assisted incline running (WAIR), and when they launch from elevated structures. The functional benefit of beating these protowings has only recently been evaluated. We report the first ontogenetic …

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Analysis Of Distal-Less Gene Expression In Ciona Intestinalis, Michelle Cangiano May 2006

Analysis Of Distal-Less Gene Expression In Ciona Intestinalis, Michelle Cangiano

Senior Honors Projects

Several homeobox-containing genes related to Distal-less (Dlx/Dll) have been isolated from a wide variety of organisms and have been shown to function as developmental regulators. In Drosophila only one Distal-less gene has been identified so far, and in vertebrates many components of the Distal-less family have been characterized. This suggests that, during the evolution of the Chordate phylum, the Dlx genes arose from an ancestral Distal-less gene via gene duplication. Three Dll homeoboxes have been isolated from the protochordate Ciona intestinalis and their clustered arrangement has been described. Since Ciona is regarded as one of the most primitive extant chordates, …

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On The Geomorphology, Hydrology, And Biogeochemistry Of Stream-Lake Interactions In The Sawtooth Mountains, Idaho, Usa, Christopher D. Arp May 2006

On The Geomorphology, Hydrology, And Biogeochemistry Of Stream-Lake Interactions In The Sawtooth Mountains, Idaho, Usa, Christopher D. Arp

Biology

This dissertation focuses on the geomorphology, hydrology, and biogeochemistry of streams and lakes as coupled, interacting ecosystems in the Sawtooth Mountains, Idaho, USA. The study design used intensive field studies of several ecosystems nested within a broader comparative study of many ecosystems. Stream geomorphology was affected by lakes due to the glacial legacy of lakes and subsequent modification of water and sediment flux. Hydrologically, streams below lakes had more frequent and longer duration floods, and lakes were shown to attenuate summer floods, but not spring snowmelt floods. Biogeochemically, nutrient uptake among streams showed high phosphate and low nitrate uptake downstream …

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Evolutionary Consequences Of An Introduced Predator: Adaptive Change In Daphnia Melanica In Response To Exotic Salmonids In The Sierra Nevada, Debra L. Fisk May 2006

Evolutionary Consequences Of An Introduced Predator: Adaptive Change In Daphnia Melanica In Response To Exotic Salmonids In The Sierra Nevada, Debra L. Fisk

Biology

The introduction of exotic species into a novel habitat, like all drastic environmental alterations, can lead to rapid evolution of both native and exotic species. Few studies have focused on the rapid adaptive evolution of native species to the introduction of a foreign species. Therefore, I wanted to determine if the introduction of exotic size-selective predators (salmonids) to alpine lakes in the Sierra Nevada, CA, has led to an adaptive response in the native prey species, Daphnia melanica. I conducted two common garden experiments with D. melanica from multiple populations, and collected data for morphological and life-history traits. With …

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Mycobacterium-Plant Interactions In Bioremediation Of Polycyclic Aromatic Hydrocarbon Compounds, Robert D. Child May 2006

Mycobacterium-Plant Interactions In Bioremediation Of Polycyclic Aromatic Hydrocarbon Compounds, Robert D. Child

Biology

Five mycobacterium isolates that degrade polycyclic aromatic hydrocarbons colonize the surface of barley roots from a seed inoculum. Colonization was maintained in the presence of an aggressive root-colonizing pseudomonad. All five of the mycobacterium strains utilized components in root washes for growth but they differed in their potential for biofilm formation. Components in the barley root washes did not impede the mineralization of pyrene. An inexpensive, portable, flexible microcosm chamber system was constructed and implemented in pyrene mineralization experiments. The system facilitated control of sterile conditions, air flow-through, and collection of volatilized radiolabeled compounds. Mineralization rates of pyrene were higher …

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A Survey Of The Bees Of Grand Staircase-Escalante National Monument, Southern Utah: Incidence, Abundance, And Community Dynamics, Olivia Messinger May 2006

A Survey Of The Bees Of Grand Staircase-Escalante National Monument, Southern Utah: Incidence, Abundance, And Community Dynamics, Olivia Messinger

Biology

A survey of the bees of Grand Staircase-Escalante National Monument, southern Utah, was conducted over a period of four years. Six hundred and fifty-six species were discovered within the monument, including numerous range extensions, several new species, and three genera new to the state of Utah. This is the richest bee landscape studied to date; reasons for the high diversity include the large elevation gradient, the richness of flowering plants, many of which are limited in distribution and require specific pollinators, and the many small local populations of species. To test the significance of these features on patterns of bee …

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Anurans Of The Solomon Islands, Gerald W. Scoville May 2006

Anurans Of The Solomon Islands, Gerald W. Scoville

Biology

Studies of Northern Melanesia have contributed prominently to our understanding of evolution, but knowledge of the distribution, abundance, and diversification of amphibians of the region remains poor. In 2004, I accompanied members of the American Museum of Natural History to the New Georgia group, Western Province of the Solomon Islands, to conduct an investigation of the anurans of the area. Data consist of descriptions of morphology, behavioral traits, ecological settings, and relative abundance and diversity, as well as a review of historical information. Platymantines of the Solomon Archipelago are exceedingly distinctive, and are likely the product of an autochthonous radiation.

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Population Genetics, Systematics, Biogeography, And Evolution Of The Southeastern Central Texas Eurycea Clade Blepsimolge (Plethodontidae), Nathan Francis Bendik May 2006

Population Genetics, Systematics, Biogeography, And Evolution Of The Southeastern Central Texas Eurycea Clade Blepsimolge (Plethodontidae), Nathan Francis Bendik

Biology Theses - Archive

The central Texas Eurycea are a diverse group of perennibranchiate salamanders which inhabit the Edwards Plateau. Although several studies have addressed the systematics and taxonomy of this group, little is known about species boundaries within the southeastern Blepsimolge. Here I assess genetic variation and phylogenetic relationships both within and among species of the southeastern Blepsimolge. Using mitochondrial DNA sequences of the control region, I examined the population structure and genetic variation of Eurycea nana as well as the evolution of the control region within Eurycea and other salamanders. No population structure was found among the three E. nana localities sampled …

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Proximate And Ultimate Mechanisms Associated With Female Secondary Coloration In The Mexican Boulder Spiny Lizard, (Sceloporus Pyrocephalus), Rebecca Marie Calisi May 2006

Proximate And Ultimate Mechanisms Associated With Female Secondary Coloration In The Mexican Boulder Spiny Lizard, (Sceloporus Pyrocephalus), Rebecca Marie Calisi

Biology Theses - Archive

Secondary sexual coloration is thought to be the result of runaway selection for signals that honestly communicate relative fitness. Much theoretical work suggests sexual selection has driven conspicuous secondary traits in males while natural selection has driven inconspicuous traits in females; however, in some species, bright female secondary coloration does exist. I used the Mexican boulder spiny lizard (Sceloporus pyrocephalus) as a model to examine secondary coloration in females. Adult females of S. pyrocephalus have conspicuously colored gular regions, ranging from red, orange, to yellow, while adult males weakly express color in the gular region. Both sexes have dark stripes …

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Closing The Loop: Controlling Type 1 Diabetes Mellitus, Megan Chynoweth May 2006

Closing The Loop: Controlling Type 1 Diabetes Mellitus, Megan Chynoweth

Whittier Scholars Program

Diabetes mellitus is an ever increasing pandemic. Type 1 diabetes mellitus (T1DM), although not the most prevalent form of diabetes mellitus, has had an “average annual increase of 3.09%, meaning the incidence of T1DM would increase 40% from 1998 to 2010”. T1DM leads to many complications: adverse side effects such as retinopathy, neuropathy, and nephropathy. These comorbidities are costing the United States billions of healthcare dollars per year. Delaying complications result in cost savings and improved quality of life, which can be obtained by tightly controlling blood sugars. However, strict control is difficult to attain. Optimal glucose levels may be …

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Biolojam – The Educational Comic, Stacey Barrie May 2006

Biolojam – The Educational Comic, Stacey Barrie

Senior Honors Projects

BioloJam is a biology comic aimed towards 7th and 8th grade students. The goal of the project was to create an educational resource that students would find entertaining and enlightening. The project is available on the web and is free to use for educational purposes by teachers, students, and parents. There are two comics: the larger, more complicated “Cell Breakout” and the smaller, more conversational “Giraffic Park.” In Cell Breakout, the three heroes are trapped inside a video game in a plant cell, and learn all about cell functions as they try to escape. In Giraffic Park, the trio are …

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Induction Of Experimental Autoimmune Thyroiditis (Eat) In Sprague-Dawley Rats And Measurements Of Severity Of Eat Using Scanning Electron Microscopy, Claudio Miguel Fernandez May 2006

Induction Of Experimental Autoimmune Thyroiditis (Eat) In Sprague-Dawley Rats And Measurements Of Severity Of Eat Using Scanning Electron Microscopy, Claudio Miguel Fernandez

Theses, Dissertations and Culminating Projects

As early as the 1950’s it was shown that animals as mice, rats, guinea pigs, and monkeys that received one injection of xenogeneic thyroglobulin emulsified in Complete Freund’s Adjuvant (CFA) developed Experimental Autoimmune Thyroiditis (EAT) (Voller et al., 1980). The damage reported was destruction of the thyroid follicles, and infiltration of the thyroid by macrophages, neutrophils, and lymphocytes. An injection of Bordetella pertussis proved to enhance the incidence and severity of EAT in animal models. Bordetella pertussis is no longer manufactured in large quantities, and it is extremely difficult to purchase. Therefore, a different procedure had to be developed that …

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Gene Deletion In Yeast That Affects Mitochondrial Dna Stability, Function And Maintenance, Rachel Charron May 2006

Gene Deletion In Yeast That Affects Mitochondrial Dna Stability, Function And Maintenance, Rachel Charron

Renée Crown University Honors Thesis Projects - All

The study of genomic analysis of deletion mutants in Saccharomyces cerevisiae associated with mitochondrial genome stability has produced both genetic and biochemical findings to be applied to the study of many mitochondrial genetic disorders in humans. Saccharomyces cerevisiae has approximately 6,200 ORFs in its genome. Of the 6,200 ORFs, 4,878 are non-essential. The EuroScarf deletion project removed all the non-essential ORFs, of the 4,878 viable haploid strains of Saccharomyces cerevisiae, and replaced them with the G418 resistance cassette. A subset of 700 deletion mutants that were previously identified as important for mitochondrial function and biogenesis was compiled from the …

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Preparation And Purification Of Enlarged Multinucleated U937 Human Leukemia Cells And Their Susceptibility To Physical Damage By Ultrasound, Kathryn Gold May 2006

Preparation And Purification Of Enlarged Multinucleated U937 Human Leukemia Cells And Their Susceptibility To Physical Damage By Ultrasound, Kathryn Gold

Renée Crown University Honors Thesis Projects - All

Multinucleation occurs in neoplastic cells that have been treated with cytochalasin B, a fungal toxin that disrupts actin microfilament structures. When the actin cytoskeleton is disrupted, contractile ring formation and cytokinesis are inhibited. In normal cells cytochalasin B prevents the cells from entering the cell cycle. However in neoplastic cells, since cytokinesis no longer occurs, the dividing cell becomes enlarged and heavily multinucleated. We propose that enlarged leukemia cells may be more sensitive to ultrasound treatment because of their increased size and weakened cytoskeletal structure. To determine the differential chemical and physical response of enlarged, multinucleated cells in comparison with …

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A Framework For Understanding Ecological Traps And An Evaluation Of Existing Evidence, Bruce A. Robertson, Richard L. Hutto May 2006

A Framework For Understanding Ecological Traps And An Evaluation Of Existing Evidence, Bruce A. Robertson, Richard L. Hutto

Biological Sciences Faculty Publications

When an animal settles preferentially in a habitat within which it does poorly relative to other available habitats, it is said to have been caught in an “ecological trap.” Although the theoretical possibility that animals may be so trapped is widely recognized, the absence of a clear mechanistic understanding of what constitutes a trap means that much of the literature cited as support for the idea may be weak, at best. Here, we develop a conceptual model to explain how an ecological trap might work, outline the specific criteria that are necessary for demonstrating the existence of an ecological trap, …

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Invasive Plant Suppresses The Growth Of Native Tree Seedlings By Disrupting Belowground Mutualisms, Kristina A. Stinson, Stuart A. Campbell, Jeff R. Powell, Benjamin E. Wolfe, Ragan M. Callaway, Giles C. Thelen, Steven G. Hallett, Daniel Prati, John N. Klironomos May 2006

Invasive Plant Suppresses The Growth Of Native Tree Seedlings By Disrupting Belowground Mutualisms, Kristina A. Stinson, Stuart A. Campbell, Jeff R. Powell, Benjamin E. Wolfe, Ragan M. Callaway, Giles C. Thelen, Steven G. Hallett, Daniel Prati, John N. Klironomos

Biological Sciences Faculty Publications

The impact of exotic species on native organisms is widely acknowledged, but poorly understood. Very few studies have empirically investigated how invading plants may alter delicate ecological interactions among resident species in the invaded range. We present novel evidence that antifungal phytochemistry of the invasive plant, Alliaria petiolata, a European invader of North American forests, suppresses native plant growth by disrupting mutualistic associations between native canopy tree seedlings and belowground arbuscular mycorrhizal fungi. Our results elucidate an indirect mechanism by which invasive plants can impact native flora, and may help explain how this plant successfully invades relatively undisturbed forest habitat.

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Hiring Criteria In Biology Departments Of Academic Institutions, Christine M. Fleet, Meredith F.N. Rosser, Rebecca A. Zufall, Marney C. Pratt, Tracy S. Feldman, Paula P. Lemons May 2006

Hiring Criteria In Biology Departments Of Academic Institutions, Christine M. Fleet, Meredith F.N. Rosser, Rebecca A. Zufall, Marney C. Pratt, Tracy S. Feldman, Paula P. Lemons

Biological Sciences: Faculty Publications

We surveyed faculty in the biology departments of US institutions of higher education to compare the experience and training valued by faculty at hiring institutions with the experience and training most graduate students receive. Our data show that associate, baccalaureate, and master's institutions value teaching experience and skills more highly than research skills. In contrast, doctoral institutions place a higher value on the ability to publish research and obtain outside funding. These findings provide quantitative and qualitative insight into discrepancies between the values of those who train graduate students in biology and the expectations of the institutions likely to hire …

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Site Directed Gene Disruption Of Rpfa In Xylella Fastidiosa : Non-Biofilm Producing Mutants As An Approach To Eradication Of Pierce's Disease In Grapevine, Janice Diane Thomas May 2006

Site Directed Gene Disruption Of Rpfa In Xylella Fastidiosa : Non-Biofilm Producing Mutants As An Approach To Eradication Of Pierce's Disease In Grapevine, Janice Diane Thomas

Theses, Dissertations and Culminating Projects

Xylella fastidious a, a gram-negative, rod shaped bacterium, causes disease in many economically important plants including citrus, coffee, and grapevine. Xylella fastidiosa is xylem limited and is dependent on insect vectors for transmission. Pierce’s Disease of Vitis vinifere grape, transmitted by an insect vector, poses a serious threat to California vineyards today. The glassy-winged sharp-shooter, Homalodisca coagulata, has caused millions of dollars of damage to the California wine industry in just a few years. There is evidence that Xylella fastidiosa may share the molecular mechanisms through which the bacterium establishes infection with a closely related species, Xanthomonas campestris. A cluster …

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Ret Dependent Changes In Gene Expression, Christian Anne Burr May 2006

Ret Dependent Changes In Gene Expression, Christian Anne Burr

Theses, Dissertations and Culminating Projects

RET is a mammalian receptor tyrosine kinase required for proper kidney and neuronal development. RET is expressed as three splice variants named RET9, RET43 and RET51 based on the splice variations at the 3’ end of the gene. All three splice variants of RET are activated by a complex of proteins including a ligand (GFL) and a co-receptor (GFR[alpha]l-4). Although there has been a great deal of work looking at the early stages of RET activation, less is known about the long-term effects, including transcriptional changes that occur in response to RET activation. In this study, transcriptional changes following RET …

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Mechanisms Underlying The Sperm Quality Advantage In Sperm Competition And Cryptic Female Choice In Drosophila Melanogaster, James Pattarini, William T. Starmer, Adam Bjork, Scott Pitnick May 2006

Mechanisms Underlying The Sperm Quality Advantage In Sperm Competition And Cryptic Female Choice In Drosophila Melanogaster, James Pattarini, William T. Starmer, Adam Bjork, Scott Pitnick

Renée Crown University Honors Thesis Projects - All

Contrary to early predictions of sperm competition theory, postcopulatory sexual selection favoring increased investment per sperm (e.g., sperm size, sperm quality) has been demonstrated in numerous organisms. Recent findings reveal that sperm production strategies are highly variable, with males of some species producing relatively few, giant sperm. We empirically demonstrate for Drosophila melanogaster that both sperm quality and sperm quantity independently contribute to competitive male fertilization success. The interaction between sperm quality and quantity suggests an internal positive reinforcement on selection for sperm quality, with selection predicted to intensify as investment per sperm increases and the number of sperm competing …

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Ventilator Induced Lung Injury, John A. Johnson Jr. May 2006

Ventilator Induced Lung Injury, John A. Johnson Jr.

Renée Crown University Honors Thesis Projects - All

Severe physical-trauma can lead to the development of acute respiratory distress syndrome (ARDS). Currently, the only known treatment for ARDS is mechanical ventilation. However, if mechanical ventilation is applied inappropriately further injury and malfunction of the lungs may occur, and thus, causing a ventilator induced lung injury (VILI). VILI has several manifestations including volutrauma, atelectrauma, and biotrauma. These mechanisms often exacerbate one another adding further insult to the injury. The goal of this current study is to establish a stable control pig model of ARDS as a comparison for ventilatory strategies that will act in a more protective manner than …

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Population Trends Of Wintering Bald Eagles (Haliaeetus Leucocephalus) At The Lake Mead National Recreation Area, Nevada, Deanna Morrell May 2006

Population Trends Of Wintering Bald Eagles (Haliaeetus Leucocephalus) At The Lake Mead National Recreation Area, Nevada, Deanna Morrell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to look at population trends of wintering bald eagles (Haliaeetus leucocephalus) at the Lake Mead National Recreation Area, Nevada from 1991 to 2006. Bald eagles were counted on January 5, 2006 along the entire shoreline of Lake Mead and Lake Mohave. This study focused on two questions: (1) how has the population changed over time? (2) How has the proportion of juvenile eagles to adult eagles changed over time? Question one was supported with the number of bald eagles significantly increasing (r=0.76, p=0.002). Question two was supported as the proportion of juveniles to adults …

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Historical Biogeography Of North American Nightsnakes And Their Relationships Among The Dipsadines: Evidence For Vicariance Associated With Miocene Formations Of Northwestern Mexico, Daniel G. Mulcahy May 2006

Historical Biogeography Of North American Nightsnakes And Their Relationships Among The Dipsadines: Evidence For Vicariance Associated With Miocene Formations Of Northwestern Mexico, Daniel G. Mulcahy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I used a hierarchical approach to study historical biogeography in a group of colubrid snakes found in western North America. I combined small regions of mtDNA sequence data from a large number of individuals, with complete mt-genomic data. First, I investigated the relationships among leptodeirines—a presumed subgroup of dipsadines, including nightsnakes (Pseudoleptodeira, Eridiphas, and Hypsiglena)—using ~1.5 kb of data (cob and nad4). The relationships differed among parsimony, likelihood, and Bayesian analyses. All analyses supported the monophyly of the nightsnakes; however, none supported the monophyly of the leptodeirines. Instead, these data supported a new hypothesis …

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Modulation Of Fast And Slow Inactivation In Two Cardiac Nav Channel Isoforms By Sdz 211-939, Tyce Jeffrey Kearl May 2006

Modulation Of Fast And Slow Inactivation In Two Cardiac Nav Channel Isoforms By Sdz 211-939, Tyce Jeffrey Kearl

Undergraduate Honors Capstone Projects

Here we report a hitherto unknown effect of a synthetic inactivation inhibitor on inactivation in cardiac sodium channels (Nav1.5) from two different species: human and bovine. SDZ 211-93 9 stabilized the slow inactivated-state in both channels as seen by an increased steady-state probability of slow inactivation. SDZ also destabilized the fast-inactivated state and increased the amplitude of persistent currents. SDZ modulated conductance parameters, open-state fast inactivation time constants, and activation kinetics of hNav1.5, but not bNav1.5. These findings will aid future studies designed to elucidate the binding site and molecular mechanisms of inactivation inhibitors …

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Emerging Physiological Significance Of R-Type Calcium Currents, Paul Jensen May 2006

Emerging Physiological Significance Of R-Type Calcium Currents, Paul Jensen

Undergraduate Honors Capstone Projects

R-type channels are voltage dependent calcium channel subtypes. To date, the only variant of the R-type calcium channel that has been isolated and cloned is the Cav2.3 variant, encoded by the gene Cchral (Yamazaki et al., 1998). The channel was named "R-type" because it was initially characterized by its resistance to nifedipine (a blocker of L-type calcium channels), Ω-conotoxin GVIA (an N-type calcium channel blocker) and Ω -Aga IVA (a blocker of P/Q-type calcium channels) (Hille 2001). The Cav2.3 calcium channel is selectively inhibited by the peptide SNX-482, which was isolated from venom of the African …

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Regulation Of Cardiac Fibroblast Metalloprotease Secretion, Glen De Guzman May 2006

Regulation Of Cardiac Fibroblast Metalloprotease Secretion, Glen De Guzman

Undergraduate Honors Capstone Projects

Matrix metalloproteases (MMPs) are proteolytic enzymes secreted by cardiac fibroblasts. Altered expression of MMPs plays an important role in congestive heart failure and other cardiovascular diseases1,2. Emerging evidence has led us to consider the role of phosphatidylinositol 4-kinase (PtdIns 4-kinase) in regulating MMP secretion in cardiac fibroblast cells3-7. PtdIns 4-kinase is a lipid kinase involved in various cellular processes including protein secretion. This project was designed to test the hypothesis that PtdIns 4-kinase controls MMP secretion. Techniques such as cardiac cell culture, transfection, and in-gel zymography were used for this experiment. Results demonstrated that PtdIns 4-kinase …

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