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Articles 1 - 21 of 21

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Nutritional And Hormonal Modulation Of Diabetes-Perturbed Folate, Homocysteine, And Methyl Group Metabolism, Kristin M. Nieman Jan 2008

Nutritional And Hormonal Modulation Of Diabetes-Perturbed Folate, Homocysteine, And Methyl Group Metabolism, Kristin M. Nieman

Retrospective Theses and Dissertations

Folate, homocysteine, and methyl group metabolism mutually function to provide methyl groups for numerous biosynthetic- and modification-type reactions necessary for optimal health. Methyl groups from these pathways are utilized in the production of important compounds such as nucleic acids, protein, and phospholipids. Thus it is vital to understand the factors that both disrupt and maintain their delicate balance to prevent disease. Disruption of these metabolic pathways is associated with several pathologies including carcinogenesis, birth defects, and vascular disease. Moreover, the disruption of these metabolic pathways may be a link between chronic disease and complications of that disease. Both nutritional and ...


Herpes Virus Icp47 And Us11 Suppression Of Ctl Activity Adapted For Use In Gene Therapy , Thomas Joseph Radosevich Jan 2003

Herpes Virus Icp47 And Us11 Suppression Of Ctl Activity Adapted For Use In Gene Therapy , Thomas Joseph Radosevich

Retrospective Theses and Dissertations

A major stumbling block encountered in gene therapy clinical trials has been the rapid destruction of the therapeutic product by the host's immune response. The goal of this work is to diminish the host Cytotoxic T Lymphocyte (CTL) response to gene therapy transgenes and transduced cells by incorporating immunosuppression genes into gene therapy vectors. The processing and presentation of antigens through the class I Major Histocompatibility Complex (class I MHC) pathway is known to be an early response to viral infection. Disruption of the class I MHC pathway results in a decrease of the CD8+ CTL response and prolongs ...


Mechanisms Of Somatostatin-Induced Paradoxical Increase In Insulin Secretion In The Presence Of Arginine Vasopressin In Clonal [Beta]-Cell Hit-T15 , Henrique Cheng Jan 2002

Mechanisms Of Somatostatin-Induced Paradoxical Increase In Insulin Secretion In The Presence Of Arginine Vasopressin In Clonal [Beta]-Cell Hit-T15 , Henrique Cheng

Retrospective Theses and Dissertations

We investigated the mechanism underlying somatostatin-induced increase in [Ca2+]i leading to insulin release in the presence of arginine vasopressin (AVP) in clonal beta-cell HIT-T15. Somatostatin increased [Ca2+]i and insulin release in a biphasic pattern, characterized by a sharp and transient increase followed by a rapid decline to the sub-basal level. Pretreatment with pertussis toxin, which inactivates Gi/Go, abolished the effects of somatostatin. U-73122, an inhibitor of phospholipase C, antagonized somatostatin-induced increase in [Ca2+] i. In Ca2+-free environment, somatostatin still increased [Ca2+]i, whereas depletion of intracellular Ca 2+ stores with thapsigargin, a microsomal Ca2+ ATPase inhibitor ...


Phospholipase C Of Clostridium Hemolyticum: Gene Characterization And Proof Of Its Role As A Protective Immunogen In Guinea Pigs , Paul Joseph Hauer Jan 2001

Phospholipase C Of Clostridium Hemolyticum: Gene Characterization And Proof Of Its Role As A Protective Immunogen In Guinea Pigs , Paul Joseph Hauer

Retrospective Theses and Dissertations

The phospholipase C (PLPC) gene from Clostridium hemolyticum was cloned using the polymerase chain reaction. An open reading frame which encodes a 399-amino acid protein, containing a 27-amino acid signal sequence, was identified. The molecular weight of the active protein was 42,869 daltons. A 16-amino acid N-terminal sequence determined by Edman degradation exactly matched the putative amino acid sequence of the gene product. Comparison of the nucleotide and amino acid sequences with Genebank databases demonstrated that the beta toxin of C. hemolyticum exhibits high homology with other bacterial PLPCs. The N-terminal portion of the beta toxin contains the zinc-binding ...


Characterization Of Intracellular Survival Of Mycobacterium Avium Subspecies Paratuberculosis In J774 Murine Macrophages , Jesse Michael Hostetter Jan 2000

Characterization Of Intracellular Survival Of Mycobacterium Avium Subspecies Paratuberculosis In J774 Murine Macrophages , Jesse Michael Hostetter

Retrospective Theses and Dissertations

Mycobacterium avium subspecies paratuberculosis (M. a. ptb) is the causative agent of Johne's disease, a progressive diarrheal disease of wild and domestic ruminants. Like other pathogenic species of mycobacteria, M. a. ptb is an intracellular pathogen of monocytes and monocyte-derived macrophages. In this dissertation we tested the hypothesis that M. a. ptb survives within macrophages by inhibition of acidification and maturation of the phagosomal compartment in which it resides;Chapter 1 consists of a general introduction and a literature review of recent reports concerning normal phagosomal maturation and maturation of the mycobacterial phagosome. Chapter 2 characterizes acidification of the ...


Primary Photoprocesses Of Light-Activated Antiviral And Antitumor Agents, Hypericin And Hypocrellin , Alexandre V. Smirnov Jan 1999

Primary Photoprocesses Of Light-Activated Antiviral And Antitumor Agents, Hypericin And Hypocrellin , Alexandre V. Smirnov

Retrospective Theses and Dissertations

The dissertation focuses on the ultrafast primary photoprocesses of the title anti-viral and anti-cancer agents, whose activity depends on light which is also accompanied by photoacidification in vesicles and living cells;By complementing the techniques of time-resolved absorption spectroscopy with those of fluorescence upconversion and applying them to hypericin, hypocrellin A and B, and their methylated analogs that are unable to execute proton transfer, it was demonstrated that intramolecular excited-state hydrogen atom transfer is a dominant primary nonradiative process;For hypocrellin A in viscous solvents such as octanol and ethylene glycol, an absorption transient of ∼10-ps duration, similar to the ...


The Effects Of Methylamine Osmolytes On The Cytoskeleton Microtubule Assembly , Huang-Chun Tseng Jan 1999

The Effects Of Methylamine Osmolytes On The Cytoskeleton Microtubule Assembly , Huang-Chun Tseng

Retrospective Theses and Dissertations

Methylamine osmolytes are enriched in urea-rich cells. It is unclear, however, whether methylamines can promote microtubule assembly either in vitro or in cells. The osmolyte trimethylamine N-oxide (TMAO) at 200 mM increases the extent and the rate of formation of polymerized microtubule complex caused by microtubule-associated protein tau in vitro. Furthermore, TMAO counteracts the inhibition on the assembly caused by urea. Besides TMAO, betaine, another methylamine osmolyte, was found to have the same effects on MT as TMAO;Phosphorylation can affect the function of tau. Cyclic-AMP-dependent protein kinase (PKA)-phosphorylated tau does not promote tubulin assembly as judged by spectrophotometric ...


Evaluation Of Mycobacterial Esat-6 As A Type-I Immune Enhancing Adjuvant , Sreekumar Ambalakkat Menon Jan 1999

Evaluation Of Mycobacterial Esat-6 As A Type-I Immune Enhancing Adjuvant , Sreekumar Ambalakkat Menon

Retrospective Theses and Dissertations

The need for improved adjuvants has continued in spite of new vaccination strategies using recombinant proteins and genetic (DNA vectored) vaccines. The Mycobacterium tuberculosis protein ESAT-6 has been shown in mice to be involved in the recall of long-lived immunity and protection in mice against tuberculosis. Thus, this protein could potentially act as a molecular adjuvant enhancing antigen-specific Type I immune responses. This study examined the hypothesis that Es could enhance Type I responses against a second antigen in mice when presented as a fusion with that antigen. This was tested using ESAT-6 fusions with two Mycoplasma hyopneumoniae surface antigens ...


The Effects Of Neutrophil-Mediated Damage In Acute Mannheimia (Pasteurella) Haemolytica Pneumonia , Zaher Ahmad Khalil Radi Jan 1999

The Effects Of Neutrophil-Mediated Damage In Acute Mannheimia (Pasteurella) Haemolytica Pneumonia , Zaher Ahmad Khalil Radi

Retrospective Theses and Dissertations

ICAM-1 expression in cattle with Bovine Leukocyte Adhesion Deficiency (BLAD) vs. cattle without BLAD in Mannheimia haemolytica (MH) pneumonia at 2 or 4 hours PI was assessed using in situ hybridization. There was a significant increase in ICAM-1 in bronchiolar and alveolar epithelium and endothelium of arteries and veins in both BLAD and non-BLAD MH-inoculated cattle compared to controls. Highest intensity of ICAM-1 was present in bronchioles while bronchi had the lowest. Most alveolar macrophages and neutrophils in infected lungs expressed ICAM-1. ICAM-1 expression was generally increased in infected BLAD cattle at 2 hours PI compared to non-BLAD but not ...


Biochemical Characterization Of Tractin And Leechcam, Two Ig-Superfamily Members Involved In Regulation Of Axonal Outgrowth Of Leech Neurons , Chunfa Jie Jan 1999

Biochemical Characterization Of Tractin And Leechcam, Two Ig-Superfamily Members Involved In Regulation Of Axonal Outgrowth Of Leech Neurons , Chunfa Jie

Retrospective Theses and Dissertations

Tractin and LeechCAM are two recently identified members of the Ig-superfamily. Tractin has a highly unusual domain organization: 6 Ig-like domains, 4 FNIII-like domains, an acidic domain, 12 repeats of a novel proline- and glycine- rich motif with sequence similarity to collagen, a transmembrane domain, and an intracellular tail with an ankyrin and a PDZ-domain binding motif. Our data show that Tractin is proteolytically processed into four fragments at two cleavage sites: one located in the third FNIII domain, and the other one located just proximal to the transmembrane domain. The most NH2-terminal fragment is shown to be glycosylated with ...


Analysis Of Viral Proteins Of Porcine Reproductive And Respiratory Syndrome Virus In Host Protection And Early Virus-Cell Interactions , Yanjin Zhang Jan 1998

Analysis Of Viral Proteins Of Porcine Reproductive And Respiratory Syndrome Virus In Host Protection And Early Virus-Cell Interactions , Yanjin Zhang

Retrospective Theses and Dissertations

The viral proteins of porcine reproductive and respiratory syndrome virus (PRRSV) were expressed in a baculovirus expression system. They were evaluated for protection of pigs against the respiratory disease and for function in virus-cell interactions. The open reading frames 2 to 6 products were confirmed to be membrane associated proteins as they were detected on the surface of viable insect cells by an immunofluorescence assay. Immunization of pigs with vaccines comprised of a combination of GP2, GP3 and GP4 or a combination of GP5, M and N proteins induced partial protection, but immunization with combination of GP5 and M proteins ...


Pou Domain Genes And The Immunoglobulin Octamer Motif In Chickens , Lynn Marie Heltemes Jan 1997

Pou Domain Genes And The Immunoglobulin Octamer Motif In Chickens , Lynn Marie Heltemes

Retrospective Theses and Dissertations

This research was undertaken to test the hypothesis that multiple POU genes exist and that POU proteins are involved in transcriptional regulation in the chicken. The POU protein Oct-2 has been hypothesized to partially regulate immunoglobulin gene expression through its interaction with the octamer motif found in the promoter of immunoglobulin genes. Transcriptional regulation of immunoglobulin genes provides a model for tissue-specific gene expression in the immune system. In searching for a chicken Oct-2 homologue, two partial chicken POU domain genes were identified. A cDNA clone encoding the POU domain of Brn-3a was isolated and showed near identity to the ...


Regulation Of Brucella Abortus Catalase As A Defensive Mechanism Against Oxidative Stress , Jeonga Kim Jan 1997

Regulation Of Brucella Abortus Catalase As A Defensive Mechanism Against Oxidative Stress , Jeonga Kim

Retrospective Theses and Dissertations

Free radicals in the nature are harmful to organisms because they cause damage to tissues, cell membranes, proteins, and DNA. The animal immune system (cell mediated immune response) uses oxygen molecules to kill foreign organisms. B. abortus causes a cattle disease called brucellosis. The mechanism for bacteria to survive and adapt in the face of oxidative attack is thought to be important for understanding pathogenesis. This dissertation presents the response of B. abortus to oxidative stress and the regulation of catalase as a defensive mechanism;Different protein expression patterns were observed during oxidative stress by conducting 2-D protein gel analysis ...


Identification Of Mouse Sip24/24p3 As A New Acute Phase Protein And Study Of Its Expression , Quansheng Liu Jan 1996

Identification Of Mouse Sip24/24p3 As A New Acute Phase Protein And Study Of Its Expression , Quansheng Liu

Retrospective Theses and Dissertations

Mouse SIP24 was originally discovered as a 24 k Da inducible protein secreted from quiescent Balb/c 3T3 fibroblast cells. Based on the analysis of peptide sequencing results and Western blot studies, SIP24 was identified as identical to the mouse protein encoded by 24P3 and is thus referred to as SIP24/24P3 in this thesis. SIP24/24P3 is a member of the lipocalin protein family, and its human homolog NGAL (neutrophil gelatinase associated lipocalin) has been reported to bind the chemotactic factor, fMLP (N-formylmethionyl-leucyl-phenylalanine);Studies were carried out to test the hypothesis that SIP24/24P3 is an acute phase protein ...


Cloning Of Bovine Intercellular Adhesion Molecules And Characterization Of Expression Of Neutrophil Adhesion Molecules In Periparturient Cows And Calves , Eunkyung Lee Jan 1996

Cloning Of Bovine Intercellular Adhesion Molecules And Characterization Of Expression Of Neutrophil Adhesion Molecules In Periparturient Cows And Calves , Eunkyung Lee

Retrospective Theses and Dissertations

The interactions of circulating leukocytes with the endothelium represent a key point in the effector functions of the immune system by regulating the specificity and strength of cell-cell interactions. The recruitment of neutrophils to sites of inflammation is initiated by chemoattractants. The initial contact of neutrophils on vascular endothelial cells is a rolling interaction mediated by members of the selectin family. These include E-selectin and P-selectin on the surface of activated endothelial cells, and L-selectin on neutrophils. The subsequent activation of leukocyte [beta]2 integrins, which bind to the glycoprotein intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, is essential for ...


Expression And Characterization Of Bovine Rotavirus Proteins In The Baculovirus System , Young Soo Lyoo Jan 1995

Expression And Characterization Of Bovine Rotavirus Proteins In The Baculovirus System , Young Soo Lyoo

Retrospective Theses and Dissertations

Recombinant proteins of bovine rotavirus VP2, VP4, VP6 and VP7 were expressed in insect cells using baculovirus expression vectors. Expressed recombinant proteins were similar to those of rotavirus. Recombinant viral antigens expressed in insect cells reacted with polyclonal antiserum to the VMRI strain of BRV by an indirect immunofluorescence test. Expressed recombinant proteins were characterized by radioimmunoprecipitation and their molecular mass was found to be similar to that of in wild type rotavirus. These four recombinant proteins were antigenic in guinea pigs and induced antibodies to the corresponding rotavirus proteins as detected by indirect immunofluorescence test. Recombinant viruses Bac.pVL ...


Identification And Characterization Of A Chicken Major Histocompatibility Complex Class Ii[Beta] Gene Promoter , Yunfei Chen Jan 1995

Identification And Characterization Of A Chicken Major Histocompatibility Complex Class Ii[Beta] Gene Promoter , Yunfei Chen

Retrospective Theses and Dissertations

The major histocompatibility complex (MHC) contains a variety of genes. Among them, the class II genes encode proteins involved in antigen presentation to helper T cells, a key step in initiating immune responses. The regulation of class II gene expression has been extensively studied in mammals. Such studies have been lacking in the avian species, despite the well-established association of the avian MHC with disease resistance and production traits. The objective of this study was to functionally analyze a putative chicken MHC class II gene promoter;Using the chloramphenicol acetyltransferase (CAT) reporter system, a functional chicken MHC class II[beta ...


Toxicity, Metabolism And Applied Uses Of 3,4-Didehydroretinol , Pamela Kay Duitsman Jan 1995

Toxicity, Metabolism And Applied Uses Of 3,4-Didehydroretinol , Pamela Kay Duitsman

Retrospective Theses and Dissertations

The comparative potencies of the all-trans isomers of 3,4-didehydroretinyl acetate (A2), retinyl acetate (A1), and retinoic acid (RA) to induce terata, embryolethality, and behavioral disruptions in offspring of timed-pregnant Sprague-Dawley rats was evaluated. Single equimolar doses (1-352 [mu]mol/kg BW) of the retinoids were given orally in corn oil on day 8.5 of gestation. All retinoids tested were teratogenic and embryolethal at dose ranges of 35-352 [mu]mol/kg BW. Embryolethality also occurred with both A2 and RA at 11 [mu]mol/kg BW. Biochemical profiles of both maternal and fetal tissue indicated that increased teratogenicity and ...


Characterization And Immunogenicity Of The Heat Shock Protein, Hsp60 Of Brucella Abortus , Dennis Gor Jan 1994

Characterization And Immunogenicity Of The Heat Shock Protein, Hsp60 Of Brucella Abortus , Dennis Gor

Retrospective Theses and Dissertations

Brucella abortus is the causative agent of bovine brucellosis, a disease that causes spontaneous abortion in cows. The most effective form of protection against this pathogen is immunization; however, Brucella abortus strain 19 (the standard vaccine against Brucella abortus) is not completely protective. The vaccination of laboratory mice with the heat shock protein, hsp60 derived from Brucella abortus, using live attenuated recombinant Salmonella typhimurium expressing this protein (hsp60) as a delivery system, and the characterization of the immune response to Brucella abortus hsp60 over a 12 week time course following vaccination is described;Infection of BALB/c strain of laboratory ...


Characterization Of The 31-Kda Antigen Gene Of Haemophilus Somnus And Its Product , Jonghwa Won Jan 1993

Characterization Of The 31-Kda Antigen Gene Of Haemophilus Somnus And Its Product , Jonghwa Won

Retrospective Theses and Dissertations

Consistent immunoreactivities of the 31-, 40- and 78-kDa proteins of Haemophilus somnus were observed in immunoblots with bovine antisera to H. somnus. A genomic library of H. somnus 8025 DNA was constructed in plasmid pUC19 and 45 recombinants expressed immunoreactive proteins in Western blots using bovine antiserum. Ten of the recombinants expressing a 31-kDa protein caused lysis of bovine erythrocytes. Restriction endonuclease mapping indicated that the hemolytic recombinants shared an approximately 1.7-kb BglII fragment. Southern blot analysis using the BglII fragment as a probe revealed homology among the recombinants and the presence of an identically sized BglII fragment in ...


Analysis And Characterization Of The Major Histocompatibility Complex Of Domestic Animals , Yuanxin Xu Jan 1990

Analysis And Characterization Of The Major Histocompatibility Complex Of Domestic Animals , Yuanxin Xu

Retrospective Theses and Dissertations

The major histocompatibility complex (MHC) is a family of genes coding for molecules which play important roles in the immune response as well as many other cellular processes of a vertebrate organism. The understanding of the immune system of some of the domestic animals will have both practical value and theoretical significance. The purpose of this work was to study the MHC of the chicken (B) and the swine (SLA). First, in order to study the MHC class II gene structure of the chicken, a genomic library was constructed from an inbred chicken line G-B2 (MHC haplotype B[superscript]6 ...