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Articles 6841 - 6870 of 8413

Full-Text Articles in Microbiology

Human Immunodeficiency Virus-1 Productively Infects Mature Terminally Differentiated Eosinophils In Hiv/Aids Patients, Jude N. Atem Jan 2008

Human Immunodeficiency Virus-1 Productively Infects Mature Terminally Differentiated Eosinophils In Hiv/Aids Patients, Jude N. Atem

Browse all Theses and Dissertations

Eosinophils express membrane CD4 protein and can bind HIV-1 glycoprotein (gp) 120. Therefore, eosinophils could serve as host cells for HIV-1 infection in vivo, especially in the late phase of the infection. In culture, HIV-1 infects eosinophil precursors and primary eosinophils. Additionally HIV-1 proviral DNA sequences have been detected in the eosinophils of some HIV-1 positive patients. Since elevated levels of eosinophils occur during HIV-1 infection and parasitic infections, it implies that co-infection of parasites and HIV-1 could cause a much greater increase in the level of potential HIV-1 susceptible eosinophils. Therefore HIV-1 infection of eosinophils could partly explain the …


The Role Of Phospholipase D (Pld) And Grb2 In Chemotaxis, Katie J. Knapek Jan 2008

The Role Of Phospholipase D (Pld) And Grb2 In Chemotaxis, Katie J. Knapek

Browse all Theses and Dissertations

Phospholipase D (PLD) is an enzyme that hydrolyzes phosphatidylcholine yielding choline and phosphatidic acid. PLD is activated by mitogens (lead to cell division) and motogens (leading to cell migration). PLD is known to contribute to cellular proliferation and deregulated expression of PLD has been implicated in several human cancers. PLD has been found to play a role in leukocyte chemotaxis and adhesion as studied through the formation of chemokine gradients. We have established a model of cell migration comprising three cell lines: macrophages RAW 264.7 and LR-5 (for innate defense), and fibroblast COS-7 cells (for wound healing). COS-7 cells respond …


Evolutionary And Structural Analyses Of Alpha-Papillomavirus Capsid Proteins Yields Novel Insights Into L2 Structure And Interaction With L1, John Lowe, Debasis Panda, Suzanne Rose, Ty Jensen, Willie Hughes, For Yue Tso, Peter C. Angeletti Jan 2008

Evolutionary And Structural Analyses Of Alpha-Papillomavirus Capsid Proteins Yields Novel Insights Into L2 Structure And Interaction With L1, John Lowe, Debasis Panda, Suzanne Rose, Ty Jensen, Willie Hughes, For Yue Tso, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Background: PVs (PV) are small, non-enveloped, double-stranded DNA viruses that have been identified as the primary etiological agent for cervical cancer and their potential for malignant transformation in mucosal tissue has a large impact on public health. The PV family Papillomaviridae is organized into multiple genus based on sequential parsimony, host range, tissue tropism, and histology. We focused this analysis on the late gene products, major (L1) and minor (L2) capsid proteins from the family Papillomaviridae genus Alpha-papillomavirus. Alpha-PVs preferentially infect oral and anogenital mucosa of humans and primates with varied risk of oncogenic transformation. Development of evolutionary associations between …


Early Childhood Infection By Human Herpesvirus 8 In Zambia And The Role Of Human Immunodeficiency Virus Type 1 Coinfection In A Highly Endemic Area, Veenu Minhas, Kay L. Crabtree, Ann Chao, Tendai J. M'Sola, Chipepo Kankasa, Marc Bulterys, Charles D. Mitchell, Charles Wood Jan 2008

Early Childhood Infection By Human Herpesvirus 8 In Zambia And The Role Of Human Immunodeficiency Virus Type 1 Coinfection In A Highly Endemic Area, Veenu Minhas, Kay L. Crabtree, Ann Chao, Tendai J. M'Sola, Chipepo Kankasa, Marc Bulterys, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma occurs at high incidence among Zambian adults and children, but there is a paucity of data on human herpesvirus 8 (HHV-8) incidence and routes of infection, especially in children. Between 1998 and 2004, the authors conducted a prospective study of viral transmission in a cohort of 684 children in Lusaka, Zambia, to estimate the annual incidence of HHV-8 from birth through 48 months of age. Maternal and pediatric human immunodeficiency virus type 1 (HIV-1) infection status was also determined. The results, based on 1,532 child-years of follow-up, showed that HHV-8 seroconversion occurs early in life. The incidence rate …


Modified Kigali Combined Staging Predicts Risk Of Mortality In Hiv-Infected Adults In Lusaka, Zambia, Philip J. Peters, Isaac Zulu, Nzali G. Kancheya, Shabir Lakhi, Elwyn Chomba, Cheswa Vwalika, Dhong-Jin Kim, Ilene Brill, Jareen Meinzen-Derr, Amanda Tichacek, Susan A. Allen Jan 2008

Modified Kigali Combined Staging Predicts Risk Of Mortality In Hiv-Infected Adults In Lusaka, Zambia, Philip J. Peters, Isaac Zulu, Nzali G. Kancheya, Shabir Lakhi, Elwyn Chomba, Cheswa Vwalika, Dhong-Jin Kim, Ilene Brill, Jareen Meinzen-Derr, Amanda Tichacek, Susan A. Allen

Nebraska Center for Virology: Faculty Publications

We assessed the utility of the modified Kigali combined (MKC) staging system for predicting survival in HIV-infected Zambian adults in a prospective, longitudinal, open cohort. From 1995 to 2004, HIV-discordant couples (one HIV-infected partner and one HIV-negative partner) were recruited from couples’ voluntary counseling and testing centers in Lusaka, Zambia and followed at 3-month intervals. MKC stage, which incorporates clinical stage with erythrocyte sedimentation rate (ESR), hematocrit, and body mass index (BMI), was determined at enrollment. Kaplan–Meier survival and Cox proportional hazard methods were used to calculate median survival and relative hazards. We enrolled 1479 HIV-discordant couples with a combined …


Development Of An Immunofluorescence Assay Using Recombinant Proteins Expressed In Insect Cells To Screen And Confirm Presence Of Human Herpesvirus 8-Specific Antibodies, Veenu Minhas, Lynsey N. Crosby, Kay L. Crabtree, Saul Phiri, Tendai J. M'Soka, Chipepo Kankasa, William J. Harrington, Charles D. Mitchell, Charles Wood Jan 2008

Development Of An Immunofluorescence Assay Using Recombinant Proteins Expressed In Insect Cells To Screen And Confirm Presence Of Human Herpesvirus 8-Specific Antibodies, Veenu Minhas, Lynsey N. Crosby, Kay L. Crabtree, Saul Phiri, Tendai J. M'Soka, Chipepo Kankasa, William J. Harrington, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human herpesvirus 8 (HHV-8), or Kaposi’s sarcoma (KS)-associated herpesvirus, has been linked to all forms of KS. The results of most current serological assays for the detection of HHV-8-specific antibodies have low levels of concordance among themselves. To establish a sensitive and specific testing strategy that can be used to screen for HHV-8-specific antibodies, three HHV-8 proteins, ORF65, ORF73, and K8.1A, were expressed by using baculoviral vectors in insect cells and incorporated into a monoclonal antibodyenhanced immunofluorescence assay (mIFA) termed the Sf9 three-antigen mIFA. The results obtained by this mIFA were compared to those obtained by a standard mIFA with …


Small-Molecule Cd4 Mimics Interact With A Highly Conserved Pocket On Hiv-1 Gp120, Navid Madani, Arne Schön, Amy M. Princiotto, Judith M. Lalonde, Joel R. Cpurter, Takahiro Soeta, Danny Ng, Liping Wang, Evan T. Brower, Shi-Hua Xiang, Young Do Kwon, Chih-Chin Huang, Richard Wyatt, Peter D. Kwong, Ernesto Freire, Amos B. Smith Iii, Joseph Sodroski Jan 2008

Small-Molecule Cd4 Mimics Interact With A Highly Conserved Pocket On Hiv-1 Gp120, Navid Madani, Arne Schön, Amy M. Princiotto, Judith M. Lalonde, Joel R. Cpurter, Takahiro Soeta, Danny Ng, Liping Wang, Evan T. Brower, Shi-Hua Xiang, Young Do Kwon, Chih-Chin Huang, Richard Wyatt, Peter D. Kwong, Ernesto Freire, Amos B. Smith Iii, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus (HIV-1) interaction with the primary receptor, CD4, induces conformational changes in the viral envelope glycoproteins that allow binding to the CCR5 second receptor and virus entry into the host cell. The small molecule NBD-556 mimics CD4 by binding the gp120 exterior envelope glycoprotein, moderately inhibiting virus entry into CD4-expressing target cells, and enhancing CCR5 binding and virus entry into CCR5-expressing cells lacking CD4. Studies of NBD-556 analogues and gp120 mutants suggest that: 1) NBD-556 binds within the Phe 43 cavity, a highly conserved, functionally important pocket formed as gp120 assumes the CD4- bound conformation; 2) the NBD-556 …


The Human Immunodeficiency Virus Type 1 Envelope Confers Higher Rates Of Replicative Fitness To Perinatally Transmitted Viruses Than To Nontransmitted Viruses, Xiaohong Kong, John T. West, Hong Zhang, Danielle M. Shea, Tendai J. M’Soka, Charles Wood Jan 2008

The Human Immunodeficiency Virus Type 1 Envelope Confers Higher Rates Of Replicative Fitness To Perinatally Transmitted Viruses Than To Nontransmitted Viruses, Xiaohong Kong, John T. West, Hong Zhang, Danielle M. Shea, Tendai J. M’Soka, Charles Wood

Nebraska Center for Virology: Faculty Publications

Selection of a minor viral genotype during perinatal transmission of human Immunodeficiency virus type 1

(HIV-1) has been observed, but there is a lack of information on the correlation of the restrictive transmission

with biological properties of the virus, such as replicative fitness. Recombinant viruses expressing the enhanced

green fluorescent protein or the Discosoma sp. red fluorescent (DsRed2) protein carrying the V1 to V5

regions of env from seven mother-infant pairs (MIPs) infected by subtype C HIV-1 were constructed, and

competition assays were carried out to compare the fitness between the transmitted and nontransmitted

viruses. Flow cytometry was used to …


Varying Efficiency Of Long-Term Replication Of Papillomaviruses In Saccharomyces Cerevisiae, Adam J. Rogers, Malte Loggen, Karen Lee, Peter C. Angeletti Jan 2008

Varying Efficiency Of Long-Term Replication Of Papillomaviruses In Saccharomyces Cerevisiae, Adam J. Rogers, Malte Loggen, Karen Lee, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Human papillomaviruses (HPVs) replicate in mitotically active basal keratinocytes. Two virally encoded proteins, E1, a helicase, and E2, a transcription factor, are important players in replication and maintenance of HPV episomes. We previously showed that HPV16 could replicate stably in Saccharomyces cerevisiae [Angeletti, P.C., Kim, K., Fernandes, F.J., and Lambert, P.F. (2002)] and we identified cis-elements that mediate replication and maintenance [J. Virol. 76(7), 3350-3358.; Kim, K., Angeletti, P.C., Hassebroek, E.C., and Lambert, P.F. (2005)]. Here, we demonstrate that although multiple HPV genomes replicate stably in yeast, they do so with differing long-term efficiency; HPV6-Ura3 is replicated at the …


Effects Of Shielding Adenoviral Vectors With Polyethylene Glycol On Vector-Specific And Vaccine-Mediated Immune Responses, Eric A. Weaver, Michael A. Barry Jan 2008

Effects Of Shielding Adenoviral Vectors With Polyethylene Glycol On Vector-Specific And Vaccine-Mediated Immune Responses, Eric A. Weaver, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Many individuals have been previously exposed to human adenovirus serotype 5 (Ad5). This prior immunity has long been known to hinder its use for gene therapy and as a gene-based vaccine. Given these immunogenicity problems, we have tested whether polyethylene glycol (PEG) can blunt immune effects against Ad5 during systemic and mucosal vaccination. Ad5 vectors were covalently modified with 5-, 20-, and 35-kDa linear PEG polymers and evaluated for their ability to produce immune responses against transgene antigen prod- ucts and the vector itself. We show that shielding Ad5 with different-sized PEGs generally reduces transduction and primary antibody responses by …


Physical And In Silico Approaches Identify Dna-Pk In A Tax Dna-Damage Response Interactome, Emad Ramadan, Michael Ward, Xin Guo, Sarah S. Durkin, Adam Sawyer, Marcelo Vilela, Christopher Osgood, Alex Pothen, Oliver J. Semmes Jan 2008

Physical And In Silico Approaches Identify Dna-Pk In A Tax Dna-Damage Response Interactome, Emad Ramadan, Michael Ward, Xin Guo, Sarah S. Durkin, Adam Sawyer, Marcelo Vilela, Christopher Osgood, Alex Pothen, Oliver J. Semmes

Biological Sciences Faculty Publications

Background: We have initiated an effort to exhaustively map interactions between HTLV-1 Tax and host cellular proteins. The resulting Tax interactome will have significant utility toward defining new and understanding known activities of this important viral protein. In addition, the completion of a full Tax interactome will also help shed light upon the functional consequences of these myriad Tax activities. The physical mapping process involved the affinity isolation of Tax complexes followed by sequence identification using tandem mass spectrometry. To date we have mapped 250 cellular components within this interactome. Here we present our approach to prioritizing these interactions via …


The Development Of A "Genetic Eyewitness" Profiling System For Low Template Forensic Specimens: Identification Of Novel Protein, Rna, And Dna Biomarkers, Erin Hanson Jan 2008

The Development Of A "Genetic Eyewitness" Profiling System For Low Template Forensic Specimens: Identification Of Novel Protein, Rna, And Dna Biomarkers, Erin Hanson

Electronic Theses and Dissertations

In many criminal investigations, valuable information regarding the physical appearance of suspected perpetrators or the time and order of events that transpired are provided by eyewitness accounts. However, the information obtained from eyewitnesses is often constrained by human recollection or subjective accounts and provides a biased description of the perpetrator's appearance or an inaccurate time line of events. Additionally, in numerous situations eyewitness accounts may not be available. An increasing reliance therefore is placed on the biological evidence recovered during criminal investigations to act as a silent witness, providing unbiased and scientific information that may aid in the resolution of …


The Endocytic Protein Numb Regulates App Metabolism And Notch Signaling: Implications For Alzheimer's Disease, George Kyriazis Jan 2008

The Endocytic Protein Numb Regulates App Metabolism And Notch Signaling: Implications For Alzheimer's Disease, George Kyriazis

Electronic Theses and Dissertations

Increased production of amyloid beta (A-beta) peptide, via altered proteolytic cleavage of amyloid protein precursor (APP), and abnormalities in neuronal calcium homeostasis play central roles in the pathogenesis of Alzheimer's disease (AD). Notch1, a membrane receptor that controls cell fate decisions during development of the nervous system, has been linked to AD because it is a substrate for the gamma-secretase protein complex in which mutations cause early-onset inherited AD. Numb is an evolutionarily conserved endocytic adapter involved in the internalization of transmembrane receptors. Mammals produce four Numb isoforms that differ in two functional domains, a phosphotyrosine-binding domain (PTB) and a …


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 …


Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs Jan 2008

Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs

OES Faculty Publications

As the international shipping fleet travels the oceans, it carries with it hidden cargoes of microbes. Fred C. Dobbs explores the hazards posed and what can be done to counteract them.


Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins Jan 2008

Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins

OES Faculty Publications

We examined the physiological responses of steady-state iron (Fe)-replete and Fe-limited cultures of the biogeochemically critical marine unicellular diazotrophic cyanobacterium Crocosphaera at glacial (19 Pa; 190 ppm), current (39 Pa; 380 ppm), and projected year 2100 (76 Pa; 750 ppm) CO2 levels. Rates of N2 and CO2 fixation and growth increased in step with increasing partial pressure of CO2 (pCO2), but only under Fe- replete conditions. N2) and carbon fixation rates at 75 Pa CO2 were 1.4-1.8-fold and 1.2-2.0-fold higher, respectively, relative to those at present day and glacial pCO2 …


Subcellular Localization Of Human T-Cell Leukemia Virus Type 1 Tax Oncoprotein, Kimberly Anne Fryrear Jan 2008

Subcellular Localization Of Human T-Cell Leukemia Virus Type 1 Tax Oncoprotein, Kimberly Anne Fryrear

Theses and Dissertations in Biomedical Sciences

Human T-cell Leukemia Virus Type 1 (HTLV-1) is a transforming retrovirus that gives rise to Adult T-cell Leukemia (ATL) and a variety of other subneoplastic conditions such as HTLV-Associated Myelopathy/Tropical Spastic Paraperesis (HAM/TSP). In ATL, the transformation and immortalization of T-lymphocytes has been attributed to the expression and activity of a single HTLV-1 viral protein, namely the trans-activating protein Tax. Although the exact mechanism of Tax-mediated transformation is uncertain, current studies support a model in which Tax induces genomic instability in the host cell through interference with DNA repair mechanisms, dysregulation of cell cycle progression, transcriptional activation of cellular …


Characteristics And Dyes Biodegradation Potential Of Crude Lignolytic Enzymes From White-Rot Fungus Crepidotus Variabilis Isolated In Coastal Tanzania, G. Y. S. Gys Mtui Dec 2007

Characteristics And Dyes Biodegradation Potential Of Crude Lignolytic Enzymes From White-Rot Fungus Crepidotus Variabilis Isolated In Coastal Tanzania, G. Y. S. Gys Mtui

Tanzania Journal of Science

Lignocellulosic enzymes from Crepidotus variabilis collected from mangrove forests of coastal Tanzania were investigated by using standard methods, and their ability to degrade aromatic compounds were elucidated. The fungal crude enzyme filtrates had maximum laccase (Lac), lignin peroxidase (LiP) and manganese peroxidase (MnP) activities of 70 U/mL, 16 U/mL and 8, U/mL respectively. The crude enzyme extracts were able to oxidize rhemazol brilliant blue-R (RBB-R) dye, phenol, "-naphthol and pyrogallol. Also, they could remove up to 58% and 92% color from raw textile effluent and aromatic dyes, respectively, after 14 days of incubation at 30ºC and pH 4.5. Desalted and …


Sara Of Staphylococcus Aureus Binds To The Sara Promoter To Regulate Gene Expression, Ambrose L. Cheung, Koren Nishina, Adhar C. Manna Dec 2007

Sara Of Staphylococcus Aureus Binds To The Sara Promoter To Regulate Gene Expression, Ambrose L. Cheung, Koren Nishina, Adhar C. Manna

Dartmouth Scholarship

The 375-bp sarA open reading frame is driven by three promoters, P1, P3, and P2. Using gel shift and DNase I footprinting assays, we found that SarA binds to two 26-bp sequences and one 31-bp sequence within the P1 and P3 promoters, respectively. Together with the results of transcription analyses, our data indicate that SarA binds to its own promoter to down-regulate sarA expression.


Oral Immunization Of Rhesus Macaques With Adenoviral Hiv Vaccines Using Enteric-Coated Capsules, George T. Mercier, Pramod N. Nehete, Marco F. Passeri, Bharti N. Nehete, Eric A. Weaver, Nancy Smyth Templeton, Kimberly Schluns, Stephanie S. Buchl, K. Buchl, Michael A. Barry Dec 2007

Oral Immunization Of Rhesus Macaques With Adenoviral Hiv Vaccines Using Enteric-Coated Capsules, George T. Mercier, Pramod N. Nehete, Marco F. Passeri, Bharti N. Nehete, Eric A. Weaver, Nancy Smyth Templeton, Kimberly Schluns, Stephanie S. Buchl, K. Buchl, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Targeted delivery of vaccine candidates to the gastrointestinal (GI) tract holds potential for mucosal immunization, particularly against mucosal pathogens like the human immunodeficiency virus (HIV). Among the different strategies for achieving targeted release in the GI tract, namely the small intestine, pH sensitive enteric coating polymers have been shown to protect solid oral dosage forms from the harsh digestive environment of the stomach and dissolve relatively rapidly in the small intestine by taking advantage of the luminal pH gradient. We developed an enteric polymethacrylate formulation for coating hydroxy-propyl-methyl-cellulose (HPMC) capsules containing lyophilized Adenoviral type 5 (Ad5) vectors expressing HIV-1 gag …


Direct Inhibition Of Cdk9 Blocks Hiv-1 Replication Without Preventing T Cell Activation In Primary Human Peripheral Blood Lymphocytes, Dominic Salerno, Muneer G Hasham, Renee Marshall Demarest, Judit Garriga, Alexander Y Tsygankov, Xavier Graña Dec 2007

Direct Inhibition Of Cdk9 Blocks Hiv-1 Replication Without Preventing T Cell Activation In Primary Human Peripheral Blood Lymphocytes, Dominic Salerno, Muneer G Hasham, Renee Marshall Demarest, Judit Garriga, Alexander Y Tsygankov, Xavier Graña

Rowan-Virtua School of Osteopathic Medicine Departmental Research

HIV-1 transcription is essential for the virus replication cycle. HIV-1 Tat is a viral transactivator that strongly stimulates the processivity of RNA polymerase II (RNAPII) via recruitment of the cyclin T1/CDK9 positive transcription elongation factor, which phosphorylates the C-terminal domain (CTD) of RNAPII. Consistently, HIV-1 replication in transformed cells is very sensitive to direct CDK9 inhibition. Thus, CDK9 could be a potential target for anti-HIV-1 therapy. A clearer understanding of the requirements for CDK9 activity in primary human T cells is needed to assess whether the CDK9-dependent step in HIV-1 transcription can be targeted clinically. We have investigated the effects …


The Isolation And Characterization Of The Microbial Flora In The Alimentary Canal Of Gromphadorhina Portentosa Based On Rdna Sequences., Amy Renee Robertson Dec 2007

The Isolation And Characterization Of The Microbial Flora In The Alimentary Canal Of Gromphadorhina Portentosa Based On Rdna Sequences., Amy Renee Robertson

Electronic Theses and Dissertations

Multicellular organisms are not single individuals but carry a complex natural microflora with them. This complex's diversity and function can be considered a distinct ecosystem. Traditional methods of isolation and identification miss >90% of the actual diversity. This study uses the gut microflora of the Madagascar hissing roach, Gromphadorhina portentosa, as a model to examine this ecosystem. Isolated cultured bacteria were used to establish methods for identifying members of the microflora based on ribosomal RNA sequences. Universal primers for Eubacterial, Archaeal, and Eukaryotic 16s/18s rRNA were then used for PCR amplification of total DNA isolated from gut contents. Sequences …


N-Glycan Modification In Aspergillus Species, Elke Kainz, Andreas Gallmetzer, Christian Hatzl, Juergen H. Nett, Huijuan Li, Thorsten Schinko, Robert Pachlinger, Harald Berger, Yazmid Reyes-Dominguez, Andreas Bernreiter, Tillmann Gerngross, Stefan Wildt, Joseph Strauss Dec 2007

N-Glycan Modification In Aspergillus Species, Elke Kainz, Andreas Gallmetzer, Christian Hatzl, Juergen H. Nett, Huijuan Li, Thorsten Schinko, Robert Pachlinger, Harald Berger, Yazmid Reyes-Dominguez, Andreas Bernreiter, Tillmann Gerngross, Stefan Wildt, Joseph Strauss

Dartmouth Scholarship

The production by filamentous fungi of therapeutic glycoproteins intended for use in mammals is held back by the inherent difference in protein N-glycosylation and by the inability of the fungal cell to modify proteins with mammalian glycosylation structures. Here, we report protein N-glycan engineering in two Aspergillus species. We functionally expressed in the fungal hosts heterologous chimeric fusion proteins containing different localization peptides and catalytic domains. . This strategy allowed the isolation of a strain with a functional -1,2-mannosidase producing increased amounts of N-glycans of the Man 5 GlcNAc 2 type. This strain was further engineered by the introduction of …


Fungal Conversion And Supercritical Carbon Dioxide Processing For Value-Added Canola Oil, Meidui Dong Dec 2007

Fungal Conversion And Supercritical Carbon Dioxide Processing For Value-Added Canola Oil, Meidui Dong

All Dissertations

There is a growing awareness of health benefits of polyunsaturated fatty acids (PUFAs) e.g. arachidonic acid (ARA, C20:4n6) and eicosapentaenoic acid (EPA, C20:5n3). In general, plant seed oil and animal fat do not contains long-chain PUFAs with more than eighteen carbons. This study investigated the feasibility for addition of ARA and EPA to canola oil through the fermentation of fungi, Mortierella alpina, using canola flake, cake or meal as substrates. Supercritical CO2 extraction was also investigated for lipid extraction. In addition, a supercritical CO2 explosion process was characterized and applied to enhance oil extraction using supercritical CO2 and to potentially …


The Effect Of Febrile Temperature On Plasmodium Falciparum, Heidi Sue Porter Dec 2007

The Effect Of Febrile Temperature On Plasmodium Falciparum, Heidi Sue Porter

Theses and Dissertations

Previously it has been shown that cultures of Plasmodium falciparum died following exposure to a febrile temperature of 40°C, as demonstrated by a decrease in parasitemia of the following generation. In the current study, the effect of 40°C treatment on culture media, erythrocytes, and parasite glucose consumption, were ruled out as possible influences on parasite death, demonstrating that 40°C impacted the parasites directly. Metabolic profiling of DNA synthesis, protein synthesis, and glucose utilization during exposure to 40°C clearly indicated that febrile temperatures had direct effect on major metabolic pathways and parasite development, beginning 20-24 hr after erythrocyte invasion. The ring …


Prevention Of Staphylococcus Epidermidis Biofilm Formation Using A Low-Temperature Processed Silver-Doped Phenyltriethoxysilane Sol–Gel Coating, Niall Stobie, Brendan Duffy, Declan Mccormack, John Colreavy, Martha Hidalgo, Patrick Mchale, Steven Hinder Dec 2007

Prevention Of Staphylococcus Epidermidis Biofilm Formation Using A Low-Temperature Processed Silver-Doped Phenyltriethoxysilane Sol–Gel Coating, Niall Stobie, Brendan Duffy, Declan Mccormack, John Colreavy, Martha Hidalgo, Patrick Mchale, Steven Hinder

Articles

Sol–gel coatings which elute bioactive silver ions are presented as a potential solution to the problem of biofilm formation on indwelling surfaces. There is evidence that high-temperature processing of such materials can lead to diffusion of silver away from the coating surface, reducing the amount of available silver. In this study, we report the biofilm inhibition of a Staphylococcus epidermidis biofilm using a low-temperature processed silver-doped phenyltriethoxysilane sol–gel coating. The incorporation of a silver salt into a sol–gel matrix resulted in an initial high release of silver in de-ionised water and physiological buffered saline (PBS), followed by a lower sustained …


Jhe In Gryllus Assimilis: Cloning, Sequence-Activity Associations And Phylogeny, E. J. Crone, Anthony J. Zera, A. Anand, J. G. Oakeshott, T. D. Sutherland, R. J. Russell, Lawrence G. Harshman, Federico G. Hoffmann, C. Claudianos Dec 2007

Jhe In Gryllus Assimilis: Cloning, Sequence-Activity Associations And Phylogeny, E. J. Crone, Anthony J. Zera, A. Anand, J. G. Oakeshott, T. D. Sutherland, R. J. Russell, Lawrence G. Harshman, Federico G. Hoffmann, C. Claudianos

Anthony Zera Publications

The 458 amino acid sequence of a mature JHE protein from the cricket Gryllus assimilis was identified after isolating the partial cDNA sequence encoding this protein from a fat body and midgut cDNA library. This hemimetabolan JHE sequence shows over 40% amino acid similarity to the known JHE sequences of several holometabolous insects. It also includes previously determined peptide sequences for G. assimilis JHE as well as two other motifs associated with JHE enzymes in holometabolous insects. The predicted molecular weight of the protein agrees with that of the JHE previously purified from G. assimilis. Partial genomic sequence encoding …


Genome-Wide Transcriptional Profiling Of The Cyclic Amp-Dependent Signaling Pathway During Morphogenic Transitions Of Candida Albicans, Yong-Sun Bahn, Matthew Molenda, Janet F. Staab, Courtney A. Lyman, Laura J. Gordon, Paula Sundstrom Dec 2007

Genome-Wide Transcriptional Profiling Of The Cyclic Amp-Dependent Signaling Pathway During Morphogenic Transitions Of Candida Albicans, Yong-Sun Bahn, Matthew Molenda, Janet F. Staab, Courtney A. Lyman, Laura J. Gordon, Paula Sundstrom

Dartmouth Scholarship

Candida albicans is an opportunistic human fungal pathogen that causes systemic candidiasis as well as superficial mucosal candidiasis. In response to the host environment, C. albicans transitions between yeast and hyphal forms. In particular, hyphal growth is important in facilitating adhesion and invasion of host tissues, concomitant with the expression of various hypha-specific virulence factors. In previous work, we showed that the cyclic AMP (cAMP) signaling pathway plays a crucial role in morphogenic transitions and virulence of C. albicans by studying genes encoding adenylate cyclase-associated protein (CAP1) and high-affinity phosphodiesterase (PDE2) (Y. S. Bahn, J. Staab, and P. Sundstrom, Mol. …


Glucose-6-Phosphate Dehydrogenase (G6pd) Screening In Pakistani Neonates: To Be Or Not To Be, Bushra Moiz Dec 2007

Glucose-6-Phosphate Dehydrogenase (G6pd) Screening In Pakistani Neonates: To Be Or Not To Be, Bushra Moiz

Department of Pathology and Laboratory Medicine

No abstract provided.