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Biochemistry, Biophysics, and Structural Biology

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Articles 1291 - 1320 of 1441

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Spontaneous Idiopathic Arteritis Of The Testicular Artery In Raccoons (Procyon Lotor), A. N. Hamir, M. V. Palmer, H. Li, J. Stasko, D. G. Rogers Jan 2009

Spontaneous Idiopathic Arteritis Of The Testicular Artery In Raccoons (Procyon Lotor), A. N. Hamir, M. V. Palmer, H. Li, J. Stasko, D. G. Rogers

School of Veterinary and Biomedical Sciences: Faculty Publications

The testes and the spermatic cord of raccoons (Procyon lotor, kits to adult breeders; n = 48) were examined. Segmental arteritis confined to the extratesticular portions of the testicular artery was present in raccoons of all ages. The arterial changes were seen in laboratory-confined experimental and control animals as well as in wild-caught raccoons. The lesions consisted of proliferative endarteritis with presence of inflammatory cells within the intima, media, and the adventitial regions of most affected vessels. Some aspects of the proliferative arterial lesions were reminiscent of systemic necrotizing vasculitis (polyarteritis nodosa), an immunologically mediated condition of animals and humans. …


Lipid Uptake And Metabolism In The Parasitic Protozoan Giardia Lamblia., Mayte Yichoy Jan 2009

Lipid Uptake And Metabolism In The Parasitic Protozoan Giardia Lamblia., Mayte Yichoy

Open Access Theses & Dissertations

Giardia lamblia is a protozoan parasite that causes various intestinal syndromes, and it is a common cause of water-borne illness worldwide, both in developed and developing countries. Giardia attaches to the mucosal epithelia of the duodenum below the bile duct, where it is exposed to bile salts and dietary lipids. G. lamblia is unable to synthesize lipids de novo and must therefore scavenge necessary lipids from its extracellular environment and remodel them as needed. However, the current lipidomic analysis (presented in this Dissertation) has revealed that while the Giardia lipidome is rich in phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylglycerol (PG), …


Hmgb1 Mediates Endogenous Tlr2 Activation And Brain Tumor Regression, James Curtin, Naiyou Liu, Marianela Candolfi, Weidong Xiong, Hikmat Assi, Kader Yagiz, Matthew Edwards, Kathrin Michelsen, Kurt Kroeger, Chunyan Liu, Akm Ghulam Muhammad, Mary Clark, Moshe Arditi, Begonya Comin-Anduix, Antoni Ribas, Pedro Lowenstein, Maria Castro Jan 2009

Hmgb1 Mediates Endogenous Tlr2 Activation And Brain Tumor Regression, James Curtin, Naiyou Liu, Marianela Candolfi, Weidong Xiong, Hikmat Assi, Kader Yagiz, Matthew Edwards, Kathrin Michelsen, Kurt Kroeger, Chunyan Liu, Akm Ghulam Muhammad, Mary Clark, Moshe Arditi, Begonya Comin-Anduix, Antoni Ribas, Pedro Lowenstein, Maria Castro

Articles

BACKGROUND: Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor that carries a 5-y survival rate of 5%. Attempts at eliciting a clinically relevant anti-GBM immune response in brain tumor patients have met with limited success, which is due to brain immune privilege, tumor immune evasion, and a paucity of dendritic cells (DCs) within the central nervous system. Herein we uncovered a novel pathway for the activation of an effective anti-GBM immune response mediated by high-mobility-group box 1 (HMGB1), an alarmin protein released from dying tumor cells, which acts as an endogenous ligand for Toll-like receptor 2 (TLR2) signaling …


Characterization Of The Ompl1 Gene Of Pathogenic Leptospira Species In China And Cross-Immunogenicity Of The Ompl1 Protein, Haiyan Dong, Ye Hu, Feng Xue, Dexter Sun, David M. Ojcius, Yafei Mao, Jie Yan Dec 2008

Characterization Of The Ompl1 Gene Of Pathogenic Leptospira Species In China And Cross-Immunogenicity Of The Ompl1 Protein, Haiyan Dong, Ye Hu, Feng Xue, Dexter Sun, David M. Ojcius, Yafei Mao, Jie Yan

All Dugoni School of Dentistry Faculty Articles

Background: The usefulness of available vaccine and serological tests for leptospirosis is limited by the low cross-reactivity of antigens from numerous serovars of pathogenic Leptospira spp. Identification of genus-specific protein antigens (GP-Ag) of Leptospira would be important for development of universal vaccines and serodiagnostic methods. OmpL1, a transmembrane porin of pathogenic leptospires, was identified as a possible GP-Ag, but its sequence diversity and immune cross-reactivity among different serovars of pathogenic leptospires remains largely unknown.

Results: PCR analysis demonstrated that the ompL1 gene existed in all 15 official Chinese standard strains as well as 163 clinical strains of pathogenic leptospires isolated …


Intraretinal Signaling By Ganglion Cell Photoreceptors To Dopaminergic Amacrine Neurons, Dao-Qi Zhang, Kwoon Y. Wong, Patricia J. Sollars, David M. Berson, Gary E. Pickard, Douglas G. Mcmahon Sep 2008

Intraretinal Signaling By Ganglion Cell Photoreceptors To Dopaminergic Amacrine Neurons, Dao-Qi Zhang, Kwoon Y. Wong, Patricia J. Sollars, David M. Berson, Gary E. Pickard, Douglas G. Mcmahon

School of Veterinary and Biomedical Sciences: Faculty Publications

Retinal dopaminergic amacrine neurons (DA neurons) play a central role in reconfiguring retinal function according to prevailing illumination conditions, yet the mechanisms by which light regulates their activity are poorly understood. We investigated the means by which sustained light responses are evoked in DA neurons. Sustained light responses were driven by cationic currents and persisted in vitro and in vivo in the presence of L-AP4, a blocker of retinal ON-bipolar cells. Several characteristics of these L-AP4-resistant light responses suggested that they were driven by melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs), including long latencies, marked poststimulus persistence, and a peak …


Regulation Of The Bioavailability Of Thioredoxin In The Lens By A Specific Thioredoxin-Binding Protein (Tbp-2), Namal P.M. Liyanage, M. Rohan Fernando, Marjorie F. Lou Aug 2008

Regulation Of The Bioavailability Of Thioredoxin In The Lens By A Specific Thioredoxin-Binding Protein (Tbp-2), Namal P.M. Liyanage, M. Rohan Fernando, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Thioredoxin (TRx) is known to control redox homeostasis in cells. In recent years, a specific TRx binding protein called thioredoxin binding protein-2 (TBP-2) was found in other cell types and it appeared to negatively regulate TRx bioavailability and thereby control TRx biological function. In view of the sensitivity of lens transparency to redox status, proper regulation of TRx bioavailability is of the utmost importance. This study was conducted to examine the presence and function of TBP-2 in human lens epithelial cells (HLE B3). We cloned human lens TBP-2 from a human cDNA library (GenBank accession number AY 594328) and showed …


The Response Of Hn4 Cells To Porphyromonas Gingivalis Dna, Cheyanne Warren Jun 2008

The Response Of Hn4 Cells To Porphyromonas Gingivalis Dna, Cheyanne Warren

Theses and Dissertations

Periodontal disease is one of the most common human diseases. Bacteria trigger the onset and progression of the disease and among them Porphyromonas gingivalis has been demonstrated to be a major etiologic agent. Although the interaction of the bacterium with the host is of major importance for the understanding of the disease mechanisms, both the host as well as the pathogen components involved in the interaction remain poorly understood. One of the bacterial components capable of eliciting a host response is unmethylated CpG DNA motifs found in bacteria. Thus, the first aim was to determine the response of oral epithelial …


Critical Involvement Of The Atm-Dependent Dna Damage Response In The Apoptotic Demise Of Hiv-1-Elicited Syncytia, Jean-Luc Perfettini, Roberta Nardacci, Mehdi Bourouba, Frederic Subra, Laurent Gros, Claire Séror, Gwenola Manic, Filippo Rosselli, Alessandra Amendola, Peggy Masdehors, Luciana Chessa, Giuseppe Novelli, David M. Ojcius, Jan Konrad Siwicki, Magdalena Chechlinska, Christian Auclair, Jose R. Regueiro, Hughes De Thé, Marie-Lise Gougeon, Mauro Piacentini, Guido Kroemer Jun 2008

Critical Involvement Of The Atm-Dependent Dna Damage Response In The Apoptotic Demise Of Hiv-1-Elicited Syncytia, Jean-Luc Perfettini, Roberta Nardacci, Mehdi Bourouba, Frederic Subra, Laurent Gros, Claire Séror, Gwenola Manic, Filippo Rosselli, Alessandra Amendola, Peggy Masdehors, Luciana Chessa, Giuseppe Novelli, David M. Ojcius, Jan Konrad Siwicki, Magdalena Chechlinska, Christian Auclair, Jose R. Regueiro, Hughes De Thé, Marie-Lise Gougeon, Mauro Piacentini, Guido Kroemer

All Dugoni School of Dentistry Faculty Articles

DNA damage can activate the oncosuppressor protein ataxia telangiectasia mutated (ATM), which phosphorylates the histone H2AX within characteristic DNA damage foci. Here, we show that ATM undergoes an activating phosphorylation in syncytia elicited by the envelope glycoprotein complex (Env) of human immunodeficiency virus-1 (HIV-1) in vitro. This was accompanied by aggregation of ATM in discrete nuclear foci that also contained phospho-histone H2AX. DNA damage foci containing phosphorylated ATM and H2AX were detectable in syncytia present in the brain or lymph nodes from patients with HIV-1 infection, as well as in a fraction of blood leukocytes, correlating with viral status. Knockdown …


Expression Analysis Of Plant Defense Responses During The Establishment Of Biotrophy And Role Of Abiotic Stress In The Infection Of Dyer’S Woad (Isatis Tinctoria) By Puccinia Thlaspeos, Elizabeth Thomas May 2008

Expression Analysis Of Plant Defense Responses During The Establishment Of Biotrophy And Role Of Abiotic Stress In The Infection Of Dyer’S Woad (Isatis Tinctoria) By Puccinia Thlaspeos, Elizabeth Thomas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The kinetics and amplitude of the salicylic acid-responsive pathogenesis-related (PR) genes and the cytochrome P450 gene ItCYP79B2 in the compatible interaction between Puccinia thlaspeos and dyer’s woad (Isatis tinctoria) during the first 72 hours of inoculation were examined. Immediately following penetration of the host by the rust pathogen, there was a modest up-regulation of PR genes but a significant down-regulation of ItCYP79B2 expression. During haustoria formation, a significant pathogen-mediated suppression of PR genes was observed with a corresponding up-regulation of ItCYP79B2. This potentially facilitates haustoria formation by P. thlaspeos. After haustoria formation, a more …


Susceptibility Of Chlamydia Trachomatis To The Excipient Hydroxy-Ethylcellulose: Ph And Concentration Dependence Of Antimicrobial Activity, Ali A. Abdul-Sater, David M. Ojcius, M. P. Meyer Apr 2008

Susceptibility Of Chlamydia Trachomatis To The Excipient Hydroxy-Ethylcellulose: Ph And Concentration Dependence Of Antimicrobial Activity, Ali A. Abdul-Sater, David M. Ojcius, M. P. Meyer

All Dugoni School of Dentistry Faculty Articles

Hydroxyethyl cellulose (HEC) is used as a neutral excipient in microbicides used against sexually transmitted pathogens. However, HEC inhibits the infection of cervical epithelial cells by Chlamydia trachomatis at pH 5 in a concentration-dependent manner. At pH 7, infection is inversely dependent on the concentration of HEC, possibly due to pH-dependent calcium sequestration.


Drug Resistance In Malaria: A Peruvian Research Experience, Ryan Haley Apr 2008

Drug Resistance In Malaria: A Peruvian Research Experience, Ryan Haley

Inquiry Journal 2008

No abstract provided.


Ozone Exposure In A Mouse Model Induces Airway Hyperreactivity That Requires The Presence Of Natural Killer T Cells And Il-17, Paul B. Savage, Muriel Pichavant, Sho Goya, Everett H. Meyer, Richard A. Johnston, Hye Y. Kim, Ponpan Matangkasombut, Ming Zhu, Yoichiro Iwakura, Rosemarie H. Dekruyff, Stephanie A. Shore, Dale T. Umetsu Feb 2008

Ozone Exposure In A Mouse Model Induces Airway Hyperreactivity That Requires The Presence Of Natural Killer T Cells And Il-17, Paul B. Savage, Muriel Pichavant, Sho Goya, Everett H. Meyer, Richard A. Johnston, Hye Y. Kim, Ponpan Matangkasombut, Ming Zhu, Yoichiro Iwakura, Rosemarie H. Dekruyff, Stephanie A. Shore, Dale T. Umetsu

Faculty Publications

Exposure to ozone, which is a major component of air pollution, induces a form of asthma that occurs in the absence of adaptive immunity. Although ozone-induced asthma is characterized by airway neutrophilia, and not eosinophilia, it is nevertheless associated with airway hyperreactivity (AHR), which is a cardinal feature of asthma. Because AHR induced by allergens requires the presence of natural killer T (NKT) cells, we asked whether ozone-induced AHR had similar requirements. We found that repeated exposure of wild-type (WT) mice to ozone induced severe AHR associated with an increase in airway NKT cells, neutrophils, and macrophages. Surprisingly, NKT cell-deficient …


Molecular Characterization Of Trypanosoma Cruzi And Shed Vesicle Components Involved In Host Immunomodulation And Cell Invasion, Ernesto Satoshi Nakayasu Jan 2008

Molecular Characterization Of Trypanosoma Cruzi And Shed Vesicle Components Involved In Host Immunomodulation And Cell Invasion, Ernesto Satoshi Nakayasu

Open Access Theses & Dissertations

Chagas disease caused by Trypanosoma cruzi is a devastating infectious disease with millions of cases in Latin America, and recently became a public health concern in United States and Europe. Although many efforts have been made for the development of an effective immunotherapy, currently there is no human vaccine for Chagas disease. Thus, the treatment is based only on two drugs that have limited efficacy and in some cases present severe side effects. One restriction for the rational approach to develop new therapies against this disease is the limited information about the proteins, glycolipids and protein posttranslational modifications expressed by …


Giardia Lamblia: Genomic And Molecular Analyses Of Flippase, Diana Leticia Villazana-Kretzer Jan 2008

Giardia Lamblia: Genomic And Molecular Analyses Of Flippase, Diana Leticia Villazana-Kretzer

Open Access Theses & Dissertations

Giardia lamblia, is an intestinal protozoan parasite responsible as a major cause of water-borne intestinal infection in humans (giardiasis). It has been proposed earlier that Giardia has limited lipid synThesis ability and therefore relies on preformed lipid molecules from outside sources. It has also been proposed that lipids are taken up through passive and active transport, and giardial flippasse play a significant role in this process. This study describes the identification and characterization of a putative homologue of flippase gene from Giardia. Flippase is an enzyme that functions as a trans-bilayer transport system facilitating the flip flop diffusion of phospholipids …


Light-Evoked Calcium Responses Of Isolated Melanopsin- Expressing Retinal Ganglion Cells, Andrew T. E. Hartwick, Jayne R. Bramley, Jianing Yu, Kelly T. Stevens, Charles N. Allen, William H. Baldridge, Patricia J. Sollars, Gary E. Pickard Dec 2007

Light-Evoked Calcium Responses Of Isolated Melanopsin- Expressing Retinal Ganglion Cells, Andrew T. E. Hartwick, Jayne R. Bramley, Jianing Yu, Kelly T. Stevens, Charles N. Allen, William H. Baldridge, Patricia J. Sollars, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

A small number (<2%) of mammalian retinal ganglion cells express the photopigment melanopsin and are intrinsically photosensitive (ipRGCs). Light depolarizes ipRGCs and increases intracellular calcium levels ( [Ca2+]i ) but the signaling cascades underlying these responses have yet to be elucidated. To facilitate physiological studies on these rare photoreceptors, highly enriched ipRGC cultures from neonatal rats were generated using anti-melanopsin-mediated plate adhesion (immunopanning). This novel approach enabled experiments on isolated ipRGCs, eliminating the potential confounding influence of rod/cone-driven input. Light induced a rise in [Ca2+]i (monitored using fura-2 imaging) in the immunopanned ipRGCs and the source of this Ca2+ signal was investigated. The Ca2+ responses were inhibited by 2-aminoethoxydiphenyl borate, SKF-96365 (1–2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl)propoxy]ethyl-1H-imidazole), flufenamic acid, …


Enhancement Of Efficacy Of Prrsv Vaccines By Altering The Glycosylation Pattern Of Viral Glycoproteins, Asit K. Pattnaik Oct 2007

Enhancement Of Efficacy Of Prrsv Vaccines By Altering The Glycosylation Pattern Of Viral Glycoproteins, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

PRRSV, the causative agent of PRRS is of major economic significance to the pork industry in the USA and around the world. Current commercial vaccine does not provide adequate protection against PRRSV outbreaks. Therefore, there is an urgent need for development of more efficacious vaccine to combat PRRS. Our previous studies have suggested that (i) induction of neutralizing antibody response is an important correlate of evaluating the efficacy of a vaccine; (ii) neutralizing antibodies can be enhanced by hypoglycosylation of the major surface glycoprotein (GP5). While it is known that GP5 plays a prominent role in neutralizing antibody induction, it …


Low Molecular Weight Protein Tyrosine Phosphatase (Lmw-Ptp) And Its Possible Physiological Functions Of Redox Signaling In The Eye Lens, Kuiyi Xing, Ashraf Raza, Stefan Lofgren, M. Rohan Fernando, Ye-Shih Ho, Marjorie F. Lou Aug 2007

Low Molecular Weight Protein Tyrosine Phosphatase (Lmw-Ptp) And Its Possible Physiological Functions Of Redox Signaling In The Eye Lens, Kuiyi Xing, Ashraf Raza, Stefan Lofgren, M. Rohan Fernando, Ye-Shih Ho, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Low molecular weight protein tyrosine phosphatase (LMW-PTP) was cloned from human lens epithelial B3 cells (HLE B3) and the recombinant enzyme was purified to homogeneity. The pure enzyme reacted positively with anti-LMW-PTP antibody, displayed tyrosine-specific phosphatase activity and was extremely sensitive to H2O2. The inactivated LMW-PTP could be regenerated by thioltransferase (TTase)/GSH system as demonstrated by both activity assay and by mass spectrometry (MS). The MS study also showed that an intramolecular disulfide bond was formed between C13 and C18 at the active site, and was reduced by the TTase/GSH system. The putative role of LMW-PTP in regulating platelet derived …


Crystal Structure Of Formate Dehydrogenase H: Catalysis Involving Mo, Molybdopterin, Selenocysteine, And An Fe4S4 Cluster, Jeffrey C. Boyington, Vadim Gladyshev, Sergei V. Khangulov, Thressa C. Stadtman, Peter D. Sun May 2007

Crystal Structure Of Formate Dehydrogenase H: Catalysis Involving Mo, Molybdopterin, Selenocysteine, And An Fe4S4 Cluster, Jeffrey C. Boyington, Vadim Gladyshev, Sergei V. Khangulov, Thressa C. Stadtman, Peter D. Sun

Vadim Gladyshev Publications

Formate dehydrogenase H from Escherichia coli contains selenocysteine (SeCys), molybdenum, two molybdopterin guanine dinucleotide (MGD) cofactors, and an Fe4S4 cluster at the active site and catalyzes the two-electron oxidation of formate to carbon dioxide. The crystal structures of the oxidized [Mo( VI), Fe4S4(ox)] form of formate dehydrogenase H (with and without bound inhibitor) and the reduced [Mo(IV ), Fe4S4(red)] form have been determined, revealing a four-domain ab structure with the molybdenum directly coordinated to selenium and both MGD cofactors. These structures suggest a reaction mechanism that directly involves SeCys …


Examination Of Microsporidia Spore Adherence And Host Cell Infection In Vitro., Timothy Robert Southern May 2007

Examination Of Microsporidia Spore Adherence And Host Cell Infection In Vitro., Timothy Robert Southern

Electronic Theses and Dissertations

Microsporidia are obligate intracellular pathogens that cause severe disease in immunocompromised humans. While albendazole is the treatment of choice, no therapy exists that effectively treats all forms or causes of human microsporidiosis. Recent studies show that the microsporidian Encephalitozoon intestinalis binds glycosaminoglycans (GAGs) associated with the host cell surface, and that the divalent cations manganese (Mn2+) and magnesium (Mg2+) augment spore adherence to host cells by activating a constituent on the spore surface. These studies also illustrate a direct relationship between spore adherence and host cell infection; inhibition of spore adherence leads to reduced host cell …


Immunoadjuvanticity Of Chlorophyll, Jocelyn Helen Parks Ramos May 2007

Immunoadjuvanticity Of Chlorophyll, Jocelyn Helen Parks Ramos

All-Inclusive List of Electronic Theses and Dissertations

Background: Vaccines are formulations containing antigenic determinants (from non-self organic matters) and immuno-enhancers called adjuvants. Together, they evoke protective immune responses in hosts. Adjuvants are substances that further vaccines' capability to induce a robust immune response. Common side effects with conventional adjuvants used in most vaccines are toxicity, inflammation and granulomas. In this study we investigated the pigment chlorophyll (Chl) for immunoadjuvanticity. The selection of chlorophyll is based on the fact that it is a component in foods such as spinach, and that it contains an isoprenoid structure that is a feature of many conventional adjuvants, Pristane and Squalene. Chl …


Hiv/Aids In Pakistan: The Battle Begins, Mohammad A. Rai, Haider J. Warraich, Syed H. Ali, Vivek R. Nerurkar Mar 2007

Hiv/Aids In Pakistan: The Battle Begins, Mohammad A. Rai, Haider J. Warraich, Syed H. Ali, Vivek R. Nerurkar

Department of Biological & Biomedical Sciences

Pakistan, the second most populous Muslim nation in the world, has started to finally experience and confront the HIV/AIDS epidemic. The country had been relatively safe from any indigenous HIV cases for around two decades, with most of the infections being attributable to deported HIV positive migrants from the Gulf States. However, the virus finally seems to have found a home-base, as evidenced by the recent HIV outbreaks among the injection drug user community. Extremely high-risk behavior has also been documented among Hijras (sex workers) and long-distance truck drivers. The weak government response coupled with the extremely distressing social demographics …


Atp Activates A Reactive Oxygen Species-Dependent Oxidative Stress Response And Secretion Of Pro-Inflammatory Cytokines In Macrophages, Christiane M. Cruz, Alessandra Rinna, Henry Jay Forman, Ana L. M. Ventura, Pedro M. Persechini, David M. Ojcius Feb 2007

Atp Activates A Reactive Oxygen Species-Dependent Oxidative Stress Response And Secretion Of Pro-Inflammatory Cytokines In Macrophages, Christiane M. Cruz, Alessandra Rinna, Henry Jay Forman, Ana L. M. Ventura, Pedro M. Persechini, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Secretion of the proinflammatory cytokines, interleukin (IL)-1β and IL-18, usually requires two signals. The first, due to microbial products such as lipopolysaccharide, initiates transcription of the cytokine genes and accumulation of the precursor proteins. Cleavage and secretion of the cytokines is mediated by caspase-1, in association with an inflammasome containing Nalp3, which can be activated by binding of extracellular ATP to purinergic receptors. We show that treatment of macrophages with ATP results in production of reactive oxygen species (ROS), which stimulate the phosphatidylinositol 3-kinase (PI3K) pathway and subsequent Akt and ERK1/2 activation. ROS exerts its effect through glutathionylation of PTEN …


Mutations In Transmembrane Domains 1, 4 And 9 Of The Plasmodium Falciparum Chloroquine Resistance Transporter Alter Susceptibility To Chloroquine, Quinine And Quinidine, Roland A. Cooper, Kristan D. Lane, Bingbing Deng, Jianbing Mu, Jigar J. Patel, Thomas E. Wellems, Xinzhuan Su, Michael T. Ferdig Jan 2007

Mutations In Transmembrane Domains 1, 4 And 9 Of The Plasmodium Falciparum Chloroquine Resistance Transporter Alter Susceptibility To Chloroquine, Quinine And Quinidine, Roland A. Cooper, Kristan D. Lane, Bingbing Deng, Jianbing Mu, Jigar J. Patel, Thomas E. Wellems, Xinzhuan Su, Michael T. Ferdig

Biological Sciences Faculty Publications

Mutations in the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT) can result in verapamil-reversible CQ resistance and altered susceptibility to other antimalarials. PfCRT contains 10 membrane-spanning domains and is found in the digestive vacuole (DV) membrane of intraerythrocytic parasites. The mechanism by which PfCRT mediates CQ resistance is unclear although it is associated with decreased accumulation of drug within the DV. On the permissive background of the P. falciparum 106/1(K76) parasite line, we used single-step drug selection to generate isogenic clones containing unique pfcrt point mutations that resulted in amino acid changes in PfCRT transmembrane domains 1 (C72R, K76N, K76I …


Pldb, A Putative Phospholipase D Homologue, Mediates Quorum Sensing In Dictyostelium Discoideum Development, Yi Chen Jan 2007

Pldb, A Putative Phospholipase D Homologue, Mediates Quorum Sensing In Dictyostelium Discoideum Development, Yi Chen

Dissertations, Theses, and Capstone Projects

Quorum sensing, the ability to measure the local cell density, is required for animal cells to achieve proper cell growth, differentiation and development. However, because of the genetic intractability of mammalian cells, we study quorum sensing in the genetically pliable unicellular eukaryote Dictyostelium discoideum. D. discoideum cells live as individual cells under vegetative conditions. Starvation sets off development to a multicellular organism. But cells won't develop unless enough cells are under starvation conditions. Approximately 105 cells are needed to form a fruiting body, the final stage of the development. When starved, cells are able to calculate the concentration …


Differential Engagement Of Tim-1 During Activation Can Positively Or Negatively Costimulate T Cell Expansion And Effector Function, Vijay K. Kuchroo, Sheng Xiao, Nader Najafian, Jay Reddy, Monica Albin, Chen Zhu, Eric Jensen, Jaimie Imitola, Thomas Korn, Ana C. Anderson, Zheng Zhang, Cristina Gutierrez, Thomas Moll, Raymond A. Sobel, Dale T. Umetsu, Hideo Yagita, Hisaya Akiba, Terry Strom, Mohamed H. Sayegh, Rosemarie H. Dekruyff, Samia J. Khoury Jan 2007

Differential Engagement Of Tim-1 During Activation Can Positively Or Negatively Costimulate T Cell Expansion And Effector Function, Vijay K. Kuchroo, Sheng Xiao, Nader Najafian, Jay Reddy, Monica Albin, Chen Zhu, Eric Jensen, Jaimie Imitola, Thomas Korn, Ana C. Anderson, Zheng Zhang, Cristina Gutierrez, Thomas Moll, Raymond A. Sobel, Dale T. Umetsu, Hideo Yagita, Hisaya Akiba, Terry Strom, Mohamed H. Sayegh, Rosemarie H. Dekruyff, Samia J. Khoury

School of Veterinary and Biomedical Sciences: Faculty Publications

It has been suggested that T cell immunoglobulin mucin (Tim)-1 expressed on T cells serves to positively costimulate T cell responses. However, crosslinking of Tim-1 by its ligand Tim-4 resulted in either activation or inhibition of T cell responses, thus raising the issue of whether Tim-1 can have a dual function as a costimulator. To resolve this issue, we tested a series of monoclonal antibodies specifi c for Tim-1 and identifi ed two antibodies that showed opposite functional effects. One anti–Tim-1 antibody increased the frequency of antigen-specifi c T cells, the production of the proinfl ammatory cytokines IFN-γ and IL-17, …


Parasites, Proteomics And Performance: Effects Of Gregarine Gut Parasites On Dragonfly Flight Muscle Composition And Function, Rudolf J. Schilder, James H. Marden Jan 2007

Parasites, Proteomics And Performance: Effects Of Gregarine Gut Parasites On Dragonfly Flight Muscle Composition And Function, Rudolf J. Schilder, James H. Marden

School of Biological Sciences: Faculty Publications

In previous work, we found that dragonflies infected with gregarine gut parasites have reduced muscle power output, loss of lipid oxidation in their flight muscles, and a suite of symptoms similar to mammalian metabolic syndrome. Here, we test the hypothesis that changes in muscle protein composition underlie the observed changes in contractile performance. We found that gregarine infection was associated with a 10-fold average reduction in abundance of a ~155·kDa fragment of muscle myosin heavy chain (MHC; ~206·kDa intact size). Insect MHC gene sequences contain evolutionarily conserved amino acid motifs predicted for calpain cleavage, and we found that calpain digestion …


Sub-Typing Of Prrsv Isolates By Means Of Measurement Of Cross-Neutralization Reactions, Fernando A. Osorio Nov 2006

Sub-Typing Of Prrsv Isolates By Means Of Measurement Of Cross-Neutralization Reactions, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

The degree of similitude or closeness between two different isolates or strains of PRRSV is very important for deciding which strains should be used for immunization, by either vaccinating with commercial vaccines or attempting to stabilize a herd with planned wt PRRSV infection. As previously known for certain important viral diseases, such as in Foot and Mouth Disease, the reciprocal (cross-) neutralization titers between two strains may be of utmost importance to establish the degree of similarity or difference between these. There is currently a void of methods that would allow distinguishing or grouping strains of PRRSV in a manner …


Characterization Of Host Cell Death Induced By Chlamydia Trachomatis, Songmin Ying, Silke F. Fischer, Matthew A. Pettengill, Debye Conte, Stefan A. Paschen, David M. Ojcius, Georg Hacker Nov 2006

Characterization Of Host Cell Death Induced By Chlamydia Trachomatis, Songmin Ying, Silke F. Fischer, Matthew A. Pettengill, Debye Conte, Stefan A. Paschen, David M. Ojcius, Georg Hacker

All Dugoni School of Dentistry Faculty Articles

Chlamydia are obligate intracellular bacteria that modulate apoptosis of the host cell. Strikingly, chlamydial infection has been reported both to inhibit and to induce apoptosis. Although the ability to inhibit apoptosis has been corroborated by the identification of cellular targets, confirmation of cell death induction has been complicated by a mixture of apoptotic features and atypical cell death during infection, as well as by differences in the experimental techniques used to measure cell death. Here we use a panel of well-established approaches in the study of apoptosis to define the form of cell death induced by Chlamydia trachomatis infection. Infected …


Microfabrication And Evaluation Of Planar Thin-Film Microfluidic Devices, Bridget Ann Peeni Oct 2006

Microfabrication And Evaluation Of Planar Thin-Film Microfluidic Devices, Bridget Ann Peeni

Theses and Dissertations

Over the past 15 years, research in the field of microfluidics has rapidly gained popularity. By seeking to miniaturize and automate separation-based analysis, microfluidic research seeks to improve current methods through decreased cost, analysis time, and sources of contamination. My work has focused on developing a novel fabrication method, based on standard microfabrication techniques, to create thin-film microfluidic devices. This microfabrication format makes it possible to generate devices that provide high efficiencies, enable mass fabrication, and provide a platform capable of integrating the microfluidic and electronic components necessary for a micro-total analysis system (μ-TAS). Device fabrication combines the processes of …


In Vivo Mature Immunological Synapses Forming Smacs Mediate Clearance Of Virally Infected Astrocytes From The Brain, Carlos Barcia, Clare Thomas, James Curtin, Gwendalyn King, Kolja Wawrowsky, Marianela Candolfi, Weidong Xiong, Chunyan Liu, Kurt Kroeger, Olivier Boyer, Jerzy Kupiec-Weglinski, David Klatzmann, Maria Castro, Pedro Lowenstein Sep 2006

In Vivo Mature Immunological Synapses Forming Smacs Mediate Clearance Of Virally Infected Astrocytes From The Brain, Carlos Barcia, Clare Thomas, James Curtin, Gwendalyn King, Kolja Wawrowsky, Marianela Candolfi, Weidong Xiong, Chunyan Liu, Kurt Kroeger, Olivier Boyer, Jerzy Kupiec-Weglinski, David Klatzmann, Maria Castro, Pedro Lowenstein

Articles

The microanatomy of immune clearance of infected brain cells remains poorly understood. Immunological synapses are essential anatomical structures that channel information exchanges between T cell–antigen-presenting cells (APC) during the priming and effector phases of T cells' function, and during natural killer–target cell interactions. The hallmark of immunological synapses established by T cells is the formation of the supramolecular activation clusters (SMACs), in which adhesion molecules such as leukocyte function-associated antigen 1 segregate to the peripheral domain of the immunological synapse (p-SMAC), which surrounds the T cell receptor–rich or central SMAC (c-SMAC). The inability so far to detect SMAC formation in …