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2006

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Articles 181 - 210 of 536

Full-Text Articles in Biology

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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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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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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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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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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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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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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Moments Of Truth In Genetic Medicine, Michael Dietrich May 2006

Moments Of Truth In Genetic Medicine, Michael Dietrich

Dartmouth Scholarship

Review of Moments of Truth in Genetic Medicine by Susan Lindee, 2005.

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Rapid Assimilation Of Yolk Enhances Growth And Development Of Lizard Embryos From A Cold Environment, Melissa Ann Blake May 2006

Rapid Assimilation Of Yolk Enhances Growth And Development Of Lizard Embryos From A Cold Environment, Melissa Ann Blake

All-Inclusive List of Electronic Theses and Dissertations

Selection for rapid growth in cold environments results in a geographic pattern known as countergradient variation. The eastern fence lizard, Sceloporus undulatus, exhibits countergradient variation in growth rate across latitudinal clines. In a common-garden experiment, S. undulatus embryos from cold environments grew more efficiently than embryos warm environments, even when the energetic contents of eggs were equalized. To examine the physiological mechanisms of higher growth efficiency, I measured the energetics of embryos during the first 49 days of incubation. Specifically, I recorded body mass, residual yolk, total respiration, and developmental stage for embyos from two populations (Virginia and South Carolina). …

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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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Tumor Suppressor Activity Of Odc Antizyme In Mek-Driven Skin Tumorigenesis, David J. Feith, Sofia Origanti, Paula L. Shoop, Suzanne Sass-Kuhn, Lisa M. Shantz May 2006

Tumor Suppressor Activity Of Odc Antizyme In Mek-Driven Skin Tumorigenesis, David J. Feith, Sofia Origanti, Paula L. Shoop, Suzanne Sass-Kuhn, Lisa M. Shantz

Biological Sciences Faculty Research and Publications

To test the hypothesis that suppression of ornithine decarboxylase (ODC) activity blocks the promotion of target cells in the outer root sheath of the hair follicle initiated by Raf/MEK/ERK activation, we crossed mice overexpressing an activated MEK mutant in the skin (K14-MEK mice) with two transgenic lines overexpressing antizyme (AZ), which binds to ODC and targets it for degradation. K14-MEK mice develop spontaneous skin tumors without initiation or promotion. These mice on the ICR background were crossed with K5-AZ and K6-AZ mice on both the carcinogenesis-resistant C57BL/6 background and the sensitive DBA/2 background. Expression of AZ driven by either the …

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Somatostatin Regulates The Extracellular Regulated Kinase Cascade Of Human Rheumatoid Arthritis Synoviocytes, Frances Mae West May 2006

Somatostatin Regulates The Extracellular Regulated Kinase Cascade Of Human Rheumatoid Arthritis Synoviocytes, Frances Mae West

Seton Hall University Dissertations and Theses (ETDs)

Somatostatin (SRIF, somatotropin release inhibitory factor) is a ubiquitously expressed neuropeptide, interacting with cells via five SRIF receptor subtypes (sst.-sst.), belonging to the guanine nucleotide binding protein-coupled receptor (GPCR) superfamily. SRIF receptors have been well documented for their ability to inhibit cell proliferation and secretion in a variety of animal tissues. Over the past l S years, pre-clinical and clinical studies implicate that SRIF and SRIF analog therapy improve symptoms in patients suffering from rheumatoid arthritis (RA). In this study, we investigate SRIF's effects on intracellular signaling in the synovium, the cellular layer that lines synovial joints, using in vitro …

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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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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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Dolomedes Scriptus (Water Spider): Male Response To Females’ Putative Pheromones On Perches., Katherine Hunt Apr 2006

Dolomedes Scriptus (Water Spider): Male Response To Females’ Putative Pheromones On Perches., Katherine Hunt

Undergraduate Theses and Capstone Projects

Sexual signals are commonly used among animals to enhance reproductive success. Chemical signals such as pheromones are commonly used to attract mates. Little is known, though, about how these signals are received or interpreted by the target. I studied the water spider, Dolomedes scriptus in the pisaurid family. Most Dolomedes species only make webs as a nursery for their young. However, females often create silk drag lines, potentially serving for species recognition. In some Dolomedes species, females who are previously mated are known to cannibalize most approaching males. Males might avoid cannibalism by avoiding mated females, particularly if they can …

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Simple Methods For Estimating Outflow Salinity From Inflow And Reservoir Storage, Koji Inosako, Fasong Yuan, S. Miyamoto Apr 2006

Simple Methods For Estimating Outflow Salinity From Inflow And Reservoir Storage, Koji Inosako, Fasong Yuan, S. Miyamoto

Biological, Geological, and Environmental Faculty Publications

Reservoir storage reduces fluctuation in streamflow salinity, as inflow blends with stored water. This process is directly relevant to reservoir management, yet the methods for predicting outflow salinity from inflow and storage data are not adequately addressed. This study examined three simple methods for estimating outflow salinity on a monthly time step. The first method applies when inflow approximately equals outflow. The second method is applicable to changing reservoir storage. The third method utilizes a two-layer model in which evaporative concentration is assumed to occur in the top layer. The third method requires the full account of the water balance, …

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A Subset Of Mer1p-Dependent Introns Requires Bud13p For Splicing Activation And Nuclear Retention, Marc Spingola, Frederick Scherrer Apr 2006

A Subset Of Mer1p-Dependent Introns Requires Bud13p For Splicing Activation And Nuclear Retention, Marc Spingola, Frederick Scherrer

Biology Department Faculty Works

In the yeast Saccharomyces cerevisiae, Mer1p is expressed only during meiosis, and its expression is linked to the splicing of at least three mRNAs: MER2, MER3, and AMA1. Previous evidence suggests that Mer1p activates splicing by directly recruiting snRNPs or stabilizing intermediate splicing complexes formed on pre-mRNA that contains an intronic Mer1p enhancer element. However, some splicing factors, especially accessory/non-snRNP factors, have critical roles in retaining unspliced pre-mRNAs in the nucleus. We tested if Mer1p may indirectly regulate splicing by preventing the export of pre-mRNAs to the cytoplasm and also demonstrated that a second subunit of the Retention and Splicing …

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2nd Annual Undergraduate Research Conference Abstract Book, University Of Missouri--Rolla Apr 2006

2nd Annual Undergraduate Research Conference Abstract Book, University Of Missouri--Rolla

Undergraduate Research Conference at Missouri S&T

No abstract provided.

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A Determination Of Phylogeny And Hybridization History Within Clematis L. (Ranunculaceae) Using Actin And Nitrate Reductase Intron Sequences, Kimberly Fearn Do Apr 2006

A Determination Of Phylogeny And Hybridization History Within Clematis L. (Ranunculaceae) Using Actin And Nitrate Reductase Intron Sequences, Kimberly Fearn Do

USF Tampa Graduate Theses and Dissertations

The phylogeny of Clematis, section Viorna, was characterized in this study using molecular data. Two nuclear introns were sequenced for a variety of taxa: actin and nitrate reductase. Actin intron sequence data yielded very little phylogenetic information. Some basal clades were resolved, but there were very few well supported relationships between species of the Viorna section in both the neighbor joining and maximum parsimony analyses. Nitrate reductase intron sequence data was slightly more variable. The number of well supported relationships in both the neighbor joining and maximum parsimony analyses for nitrate reductase was greater, but still not sufficient …

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Mechanism Of Enhanced Activity Of Liposome-Entrapped Aminoglycosides Against Resistant Strains Of Pseudomonas Aeruginosa, Clement Mugabe, Majed Halwani, Ali Azghani, Robert M. Lafrenie, Abdelwahab Omri Apr 2006

Mechanism Of Enhanced Activity Of Liposome-Entrapped Aminoglycosides Against Resistant Strains Of Pseudomonas Aeruginosa, Clement Mugabe, Majed Halwani, Ali Azghani, Robert M. Lafrenie, Abdelwahab Omri

Biology Faculty Publications and Presentations

Pseudomonas aeruginosa is inherently resistant to most conventional antibiotics. The mechanism of resistance of this bacterium is mainly associated with the low permeability of its outer membrane to these agents. We sought to assess the bactericidal efficacy of liposome-entrapped aminoglycosides against resistant clinical strains of P. aeruginosa and to define the mechanism of liposome-bacterium interactions. Aminoglycosides were incorporated into liposomes, and the bactericidal efficacies of both free and liposomal drugs were evaluated. To define the mechanism of liposome-bacterium interactions, transmission electron microscopy (TEM), flow cytometry, lipid mixing assay, and immunocytochemistry were employed. Encapsulation of aminoglycosides into liposomes significantly increased their …

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