Digital Commons Network^™

Efficacy Of Oral Administration Of Sodium Iodide To Prevent Bovine Respiratory Disease Complex, B. M. Shoemake, B. L. Vander Ley, B. W. Newcomer, M. C. Heller

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: The prevention of bovine respiratory disease complex (BRD) in beef cattle is important to maintaining health and productivity of calves in feeding operations.

Objective: Determine whether BRD bacterial and viral pathogens are susceptible to the lactoperoxidase/hydrogen peroxide/ iodide (LPO/H₂O₂/I^-) system in vitro and to determine whether the oral administration of sodium iodide (NaI) could achieve sufficient concentrations of iodine (I) in the respiratory secretions of weaned beef calves to inactivate these pathogens in vivo.

Animals: Sixteen weaned, apparently healthy, commercial beef calves from the University of Missouri, College of Veterinary Medicine teaching herd. …

Technology Development For Detection Of Circulating Disease Biomarkers From Liquid Biopsies Using Multifunctional Nanomaterials, Mustafa Balcioglu

Legacy Theses & Dissertations (2009 - 2024)

Despite the advance health care, devastating health conditions such as cancer and infectious diseases that affect populations worldwide are too often not diagnosed until morbid symptoms become apparent in the late phase. Obtaining an early and accurate diagnosis that reveal a hidden lethal threat before the disease becomes complicated may dramatically reduce the severity of its impact on the patient’s life and increase the probability of survival. For example, in the case of ovarian cancer, which is the fifth most common malignancy and the fifth leading cause of cancer mortality in women in the US, the 5-year relative survival is …

Cyclic Adenosine Monophosphate Signaling In Mycobacterium Tuberculosis : New Insights Into A Universal Second Messenger, Richard Mcpherson Johnson

Legacy Theses & Dissertations (2009 - 2024)

Despite being the focus of intense research for many years Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), remains the deadliest bacterial pathogen plaguing mankind today. Humans are the sole host and reservoir for Mtb, and Mtb has coevolved closely with its human host for thousands of years. Mtb currently infects over two billion people worldwide and over 1.5 million people die from TB each year, arguably making Mtb the most successful bacterial pathogen on the planet.

The Dissemination, Regulatory Role, And Evolution Of Mycobacterial Inteins, Danielle Skye Kelley

Legacy Theses & Dissertations (2009 - 2024)

Inteins are intervening protein elements, capable of coordinating escape from a host protein through a self-catalyzed mechanism, called protein splicing. This results in free intein and a mature host protein product. Inteins are also mobile elements and many contain homing endonucleases that enable the targeting to ectopic sites and invasion of novel niches. Inteins have been found across all three domains of life and are often present in replication, recombination, and repair proteins. However, it is unclear if the observed distribution is simply a factor of endonuclease preference or if inteins have been selectively maintained due to an adaptation that …

Complete Genome Sequence Of Moraxella Bovis Strain Epp-63 (300), An Etiologic Agent Of Infectious Bovine Keratoconjunctivitis, John Dustin Loy, Aaron M. Dickey, Michael L. Clawson

School of Veterinary and Biomedical Sciences: Faculty Publications

We report here the complete closed genome sequence of Moraxella bovis strain Epp-63 (300) (Epp63). This strain was isolated from an infectious bovine keratoconjunctivitis (IBK) case in 1963. Since then, Epp63 has been used extensively for IBK research. Consequently, the genome sequence of Epp63 should help elucidate IBK host-pathogen interactions.

Integrated Immunoassays On Paper/Polymer Hybrid Microfluidic Devices For Low-Cost Detection Of Disease Biomarkers, Sanjay Sharma Timilsina

Open Access Theses & Dissertations

Infectious diseases and cancers have been the major cause of global death and disability causing a significant impact on global health and economies. Enzyme-linked immunosorbent assay (ELISA) is one of the most widely used laboratory diagnostic methods for infectious diseases and cancer. ELISA detects proteins based on their binding to immobilized antibodies or antigen. Even though most ELISAs performed today in 96-well plates are well suited for high throughput assays, performing ELISA in low-resource settings is limited by several factors, such as long incubation time, large volumes of precious reagents, and well-equipped laboratories. Herein, we have developed multiple simple, miniaturized …

Sporadic Appearance Of Paralytic Spongiform Neurodegeneration In A Colony Of Inbred Mice Is Associated With Cns Retrovirus Expression, Magdalene Durbak

Williams Honors College, Honors Research Projects

Abstract

Exogenous and endogenous retroviruses (RV) have been known to induce vacuolar central nervous system neuropathology. Two mice which were juvenile inbred Rocky Mountain White (IRW), showed signs of spontaneous degenerate motor neuron disease. Signs included wasting, unkempt fur, adduction reflex upon tail elevation, kyphosis, and stilted gait by postnatal day 18 (P18). Brains and spinal cords were examined with H&E staining and stained with a broadly reactive retrovirus antibody. When compared to brains of mice with normal vacuolar pathology as well as mice infected with prototypic non-neurovirulent RV, Fr57E and prototypic neurovirulent RV FrCasE, the subject showed less severity …

Optimisation Of Ion Exchange Chromatography Purification Protocols For A Staphylococcal Peptidoglycan Degrading Hydrolase Enzyme, Fiona Maher

Theses

Bacteriophage (phage) are the most abundant biological entities on earth and were first discovered by d’Herelle in 1917. They are found wherever their hosts live and, like all viruses they do not have the ability to make their own protein. Therefore, in order to reproduce, phage must invade and infect bacterial cells. This project focused on the optimisation of Ion Exchange Chromatography purification protocols for a staphylococcal peptidoglycan degrading hydrolase enzyme (CHAPk). The project objective was to obtain the greatest yield of enzyme from the growth of the E.coU XL 1-Blue expression system into which the vector pQE60 was previously …

Development Of Septic Polysynovitis And Uveitis In Foals Experimentally Infected With Rhodococcus Equi, Laura Huber, Steeve Giguère, Londa J. Berghaus, Amanda Hanafi, Sarah Vitosh-Sillman, Sarah L. Czerwinski

School of Veterinary and Biomedical Sciences: Faculty Publications

Rhodococcus equi is one of the most important causes of disease in foals. Infection is typically characterized by pyogranulomatous pneumonia although extrapulmonary infections occur occasionally. Uveitis and polysynovitis have been reported in foals naturally infected with R. equi and are thought to be the result of an immune-mediated process. However, the pathogenesis of these conditions is poorly understood. The objectives of this study were to document the occurrence of uveitis and polysynovitis after experimental infection with R. equi and to determine if these disorders are the direct result of infection at these sites. Foals between 3 and 4 weeks of …

Alkaline Stabilization Of Manure Slurry Inactivates Porcine Epidemic Diarrhea Virus, Erin E. Stevens, Daniel N. Miller, Bethany A. Brittenham, Sarah J. Vitosh-Sillman, Bruce W. Brodersen, Virginia L. Jin, John D. Loy, Amy M. Schmidt

School of Veterinary and Biomedical Sciences: Faculty Publications

Hydrated lime manure treatment was evaluated to determine porcine epidemic diarrhea virus (PEDV) susceptibility to alkaline stabilization. At pH 10, PEDV decreased (quantitative polymerase chain reaction) and lost infectivity (swine bioassay). Although ammonium decreased above pH 9 (up to 25%), alkaline stabilization managed to control potential infection from manure sources.

Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry Identification Of Moraxella Bovoculi And Moraxella Bovis Isolates From Cattle, Kara Robbins, Aaron M. Dickey, Michael L. Clawson, John Dustin Loy

School of Veterinary and Biomedical Sciences: Faculty Publications

Infectious bovine keratoconjunctivitis (IBK) is an economically significant disease caused by Moraxella bovis. Moraxella bovoculi, although not reported to cause IBK, has been isolated from the eyes of cattle diagnosed with IBK. Identification of M. bovis and M. bovoculi can be performed using biochemical or DNA-based approaches, both of which may be time consuming and inconsistent between laboratories. We conducted a comparative evaluation of M. bovoculi and M. bovis identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with a database provided by Bruker Daltonics (termed the BDAL database), the BDAL database supplemented with spectra generated in …

Circadian Behavioral Responses To Light And Optic Chiasm-Evoked Glutamatergic Epscs In The Suprachiasmatic Nucleus Of Iprgc Conditional Vglut2 Knock-Out Mice, Michael G. Moldavan, Patricia J. Sollars, Michael R. Lasarev, Charles N. Allen, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

Intrinsically photosensitive retinal ganglion cells (ipRGCs) innervate the hypothalamic suprachiasmatic nucleus (SCN), a circadian oscillator that functions as a biological clock. ipRGCs use vesicular glutamate transporter 2 (vGlut2) to package glutamate into synaptic vesicles and light-evoked resetting of the SCN circadian clock is widely attributed to ipRGC glutamatergic neurotransmission. Pituitary adenylate cyclase-activating polypeptide (PACAP) is also packaged into vesicles in ipRGCs and PACAP may be coreleased with glutamate in the SCN. vGlut2 has been conditionally deleted in ipRGCs in mice [conditional knock-outs (cKOs)] and their aberrant photoentrainment and residual attenuated light responses have been ascribed to ipRGC PACAP release. However, …

Development Of A Multiplex Real-Time Pcr Assay Using Two Thermocycling Platforms For Detection Of Major Bacterial Pathogens Associated With Bovine Respiratory Disease Complex From Clinical Samples, John Dustin Loy, Laura Leger, Aspen M. Workman, Michael L. Clawson, Ece Bulut, Bing Wang

School of Veterinary and Biomedical Sciences: Faculty Publications

Bovine respiratory disease complex (BRDC) is one of the most significant diseases of cattle. Bacterial pathogens involved in BRDC include Mannheimia haemolytica, Mycoplasma bovis, Histophilus somni, and Pasteurella multocida. We developed and evaluated a multiplexed real-time hydrolysis probe (rtPCR) assay using block-based Peltier and rotary-based thermocycling on lung tissue, nasal swabs, and deep nasopharyngeal swabs. The rtPCR results were compared to culture or a gel-based M. bovis PCR using statistical analysis to determine optimum quantification cycle (Cq) cutoffs to maximize agreement. The limits of detection were 1.2–12 CFU/reaction for each pathogen. M. haemolytica was the most prevalent organism detected …

Coordinated Regulation Of Transcription By Ccpa And The Staphylococcus Aureus Twocomponent System Hptrs, Joseph M. Reed, Sean Olson, Danielle F. Brees, Caitlin E. Griffin, Ryan A. Grove, Paul J. Davis, Stephen D. Kachman, Jiri Adamec, Greg A. Somerville

School of Veterinary and Biomedical Sciences: Faculty Publications

The success of Staphylococcus aureus as a pathogen is due in part to its ability to adapt to changing environmental conditions using signal transduction pathways, such as metaboliteresponsive regulators and two-component systems. S. aureus has a two-component system encoded by the gene pair sav0224 (hptS) and sav0223 (hptR) that regulate the hexose phosphate transport (uhpT) system in response to extracellular glucose-6-phosphate. Glycolytic intermediates such as glucose-6-phosphate are important carbon sources that also modulate the activity of the global metabolite-responsive transcriptional regulator CcpA. Because uhpT has a putative CcpA binding site in its promoter and …

Novel Docosahexaenoic Acid Ester Of Phloridzin Inhibits Proliferation And Triggers Apoptosis In An In Vitro Model Of Skin Cancer, Theodora Mantso, Dimitrios T. Trafalis, Sotiris Botaitis, Rodrigo Franco, Aglaia Pappa, H. P. Vasantha Rupasinghe, Mihalis I. Panayiotidis

School of Veterinary and Biomedical Sciences: Faculty Publications

Skin cancer is among the most common cancer types accompanied by rapidly increasing incidence rates, thus making the development of more efficient therapeutic approaches a necessity. Recent studies have revealed the potential role of decosahexaenoic acid ester of phloridzin (PZDHA) in suppressing proliferation of liver, breast, and blood cancer cell lines. In the present study, we investigated the cytotoxic potential of PZDHA in an in vitro model of skin cancer consisting of melanoma (A375), epidermoid carcinoma (A431), and non-tumorigenic (HaCaT) cell lines. Decosahexaenoic acid ester of phloridzin led to increased cytotoxicity in all cell lines as revealed by cell viability …

Whole Genome Sequencing Of Moraxella Bovoculi Reveals High Genetic Diversity And Evidence For Interspecies Recombination At Multiple Loci, Aaron M. Dickey, Gennie Schuller, John D. Loy, Michael L. Clawson

School of Veterinary and Biomedical Sciences: Faculty Publications

Moraxella bovoculi is frequently cultured from the ocular secretions and conjunctiva of cattle with Infectious Bovine Keratoconjunctivitis (IBK). Previous work has shown that single nucleotide polymorphism (SNP) diversity in this species is quite high with 81,284 SNPs identified in eight genomes representing two distinct genotypes isolated from IBK affected eyes (genotype 1) and the nasopharynx of cattle without clinical IBK signs (genotype 2), respectively. The goals of this study were to identify SNPs from a collection of geographically diverse and epidemiologically unlinked M. bovoculi strains from the eyes of IBK positive cattle (n = 183) and another from the eyes …

Differential Modulation Of Human Gabac‑Ρ1 Receptor By Sulfur‑Containing Compounds Structurally Related To Taurine, Lenin David Ochoa‑De La Paz, Martin González‑Andrade, Herminia Pasantes‑Morales, Rodrigo Franco, Rubén Zamora‑Alvarado, Edgar Zenteno, Hugo Quiroz‑Mercado, Roberto Gonzales‑Salinas, Rosario Gulias‑Cañizo

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: The amino acid taurine (2-Aminoethanesulfonic acid) modulates inhibitory neurotransmitter receptors. This study aimed to determine if the dual action of taurine on GABAC- ρ1R relates to its structure. To address this, we tested the ability of the structurally related compounds homotaurine, hypotaurine, and isethionic acid to modulate GABAC- ρ1R.

Results: In Xenopus laevis oocytes, hypotaurine and homotaurine partially activate heterologously expressed GABAC- ρ1R, showing an increment in its deactivation time with no changes in channel permeability, whereas isethionic acid showed no effect. Competitive assays suggest that hypotaurine and homotaurine compete for the GABA-binding site. In addition, their effects were …

Using Art And Story To Explore How Primary School Students In Rural Tanzania Understand Planetary Health: A Qualitative Analysis, Elizabeth Vanwormer, Jesca Mlawa, Elizabeth Komba, Christopher Gustafson, Hilda Mrema, Jenny M. Dauer

School of Veterinary and Biomedical Sciences: Faculty Publications

Background The global planetary health community increasingly recognises the need to prepare students to investigate and address connections between environmental change and human health. As we strive to support education on planetary health themes for students of all ages, understanding students’ concepts of linkages between the health of people and animals, and their shared environments might advance educational approaches. Children living in villages bordering Ruaha National Park in Iringa Region, Tanzania, have direct experience of these connections as they share a water-stressed but biodiverse environment with domestic animals and wildlife. Livelihoods in these villages depend predominantly on crop and livestock …

Tellurite Resistance In Shiga Toxin-Producing Escherichia Coli , Gentry L. Lewis, Quentin R. Jorgensen, John Dustin Loy, Rodney A. Moxley

School of Veterinary and Biomedical Sciences: Faculty Publications

Potassium tellurite ( K₂TeO₃) is an effective selective agent for O157:H7 Shiga toxin-producing Escherichia coli (STEC), whereas tellurite resistance in non-O157 STEC is variable with information on O45 minimal. High-level K₂TeO₃ resistance in STEC is attributable to the ter gene cluster with terD an indicator of the cluster’s presence. Polymerase chain reactions for terD and K₂TeO₃ minimum inhibitory concentration (MIC) determinations in broth cultures were conducted on 70 STEC and 40 non-STEC control organisms. Sixty-six STEC strains (94.3%) were terD+ compared to 28 control organisms (70.0%; P < 0.001). The prevalence of terD in …

Epitope Mapping Of Serca2a Identifies An Antigenic Determinant That Induces Mainly Atrial Myocarditis In A/J Mice, Bharathi Krishnan, Chandirasegara Massilamany, Rakesh H. Basavalingappa, Arunakumar Gangaplara, Rajkumar Rajasekaran, Muhammad Z. Afzal, Vahid Khalilzad-Sharghi, You Zhou, Jean-Jack Riethoven, Shyam S. Nandi, Paras K. Mishra, Raymond A. Sobel, Jennifer L. Strande, David Steffen, Jay Reddy

School of Veterinary and Biomedical Sciences: Faculty Publications

Sarcoplasmic/endoplasmic reticulum Ca²⁺ adenosine triphosphatase (SERCA)2a, a critical regulator of calcium homeostasis, is known to be decreased in heart failure. Patients with myocarditis or dilated cardiomyopathy develop autoantibodies to SERCA2a suggesting that they may have pathogenetic significance. In this report, we describe epitope mapping analysis of SERCA2a in A/J mice that leads us to make five observations: 1) SERCA2a contains multiple T cell epitopes that induce varying degrees of myocarditis. One epitope, SERCA2a 971–990, induces widespread atrial inflammation without affecting noncardiac tissues; the cardiac abnormalities could be noninvasively captured by echocardiography, electrocardiography, and magnetic resonance microscopy imaging. 2) SERCA2a …

Evaluation Of Ispe For Inhibitor Design In The Non-Mevalonate Pathway, Kataryzna Barbara Hoerchler

Graduate Research Theses & Dissertations

There is an urgent need to discover new antibiotics to combat the emergence of drug resistant Novel antibiotics that target unique pathways different from existing therapies are promising targets. The non-mevalonate pathway (MEP), which was discovered in the 1990’s, is essential for most bacteria, plants and apicomplexan parasites. Inhibition of the non-mevalonate is an attractive pharmaceutical target, since it is not present in mammals. Many compounds have surfaced as potential inhibitors, but none have made it to market. This thesis investigates the fourth step in the MEP pathway involving the enzyme 4-diphosphocytidyl-2-C-methyl-D-erythritol kinase (IspE) from Escherichia coli (Ec), Burkholderia thailandensis …

Protein Engineering In The Study Of Protein Labeling And Degradation, Xinyi Zhang

Theses and Dissertations--Chemistry

Proteins are large macromolecules that play important roles in nature. With the development of modern molecular biology techniques, protein engineering has emerged as a useful tool and found many applications in areas ranging from food industry, environmental protection, to medical and life science. Biomimetic membrane incorporates biological elements, such as proteins, to form membranes that mimic the high specificity and conductance of natural biological membranes. For any application involving the usage of proteins, the first barrier is always the production of proteins with sufficient stability, and the incorporation of proteins into the artificial matrix. This thesis contains two major parts, …

Peptide-Drug Conjugate For Her2-Targeted Drug Delivery, Yan Wang

University of the Pacific Theses and Dissertations

Recent strategies for anticancer drug design have been focused on utilizing antibody as a drug or targeted moiety for targeted drug delivery. Antibody−drug conjugates (ADCs) have become a promising new class of targeted therapeutic agents for treatment of cancer. ADCs are designed to preferentially direct a cytotoxic drug to a cell-surface antigen recognized by an antibody. However, there are some challenges in developing ADCs, such as limited solid tumor penetration, high manufacturing costs and antibody-drug stoichiometry. Smaller molecules such as peptides have been shown to specifically bind to cancer related targets. These peptides can be used to form peptide-drug conjugates …

Environmental And Genetic Factors Affecting Antibiotic Resistance Of Extended Spectrum Î?-Lactamase Bacteria From The Rio Grande River In El Paso, Tx And Cd. Juarez, Mexico, Maria D. Fuentes

Open Access Theses & Dissertations

Background: The Rio Grande River provides a major source of potable and agricultural water for the population of the Texas/Mexico border region. Cattle farming and ranching are the most prevalent activities, which may contribute to the microbial burden of pharmaceuticals into our state's water resources. Antibiotics, presumably released into the environment by discharges originating from waste-water treatment plants, septic disposal systems, animal feeding operations and urban runoff have a definite impact on the ecosystem and may contribute to an increase in antibiotic resistance. We hypothesized that waters of the Rio Grande River contained Multi Drug Resistant Organisms (MDRO) and mobile …

Crispr/Cas9-Induced Genetic Disruption And Characterization Of Udp-Galactopyranose Mutase In Trypanosoma Cruzi, Claudia Manriquez

Open Access Theses & Dissertations

The protozoan parasite, Trypanosoma cruzi, is the causative agent of Chagas disease (ChD), or American trypanosomiasis, which affects 6-8 million people in Latin America. It is estimated that 2-3 million people will develop severe lifelong cardiac and/or digestive disorders. ChD has become a life threat not only to endemic regions but most recently also to nonendemic regions, including the United States, owing to extensive worldwide migration in recent years. The lack of a vaccine and the limited efficacy of the two drug treatments available make it urgent to develop novel therapies to treat such a threatening disease. UDP-Galactopyranose mutase (UGM) …

Development Of Simple Devices For Point-Of-Care Screening Of Bacterial Infection And Inflammatory Markers, Julaluk Noiphung

Chulalongkorn University Theses and Dissertations (Chula ETD)

A paper-based analytical devices (PADs) provides a great benefit in medical diagnostics, especially in the developing world. The first part of this dissertation describes the effect of sample viscosity on PADs for the measurement of pH and nitrite concentration in human saliva. Preliminary study found that viscosity had a significant effect on the calibration curve of nitrite and a consistent curve could be generated after added washing buffer. Nitrite measurement in artificial saliva with viscosity 1.87-5.10 mPa-s was tested on the proposed device and also showed a good correlation with the standard spectrophotometry method (p=0.8484, paired sample t-test, n=20). Moreover, …

Functional Characterization Of White Spot Syndrome Virus-Responsive Mir-750 In Black Tiger Shrimp Penaeus Monodon, Nichaphat Kanoksinwuttipong

Chulalongkorn University Theses and Dissertations (Chula ETD)

In the RNA interference (RNAi) process, small RNAs called microRNAs (miRNAs) modulate gene expression post-transcriptionally by acting as guides to direct Argonaute (Ago)-containing RNA-induced silencing complexes (RISCs) to targeted mRNAs. The Penaeus monodon miR-750 was previously reported as the highly upregulated miRNA during white spot syndrome virus (WSSV) infection. In this study, the computational program and 2D gel electrophoresis technique were used to identify miR-750 target genes. Bioinformatic analysis suggested that the predicted target mRNAs of miR-750 were ubiquitin-conjugating enzyme E2 Q1 gene (UbcQ1), Actin1 (Act1) and Sarcoplasmic calcium-binding protein (Scp). Furthermore, the alteration of protein expression in the stomach …

Identification And Functional Characterization Of Genes And Micrornas From Penaeus Vannamei In Response To Pathogens And Heat Stress, Pakpoom Boonchuen

Chulalongkorn University Theses and Dissertations (Chula ETD)

In the present day, high-throughput (HT) sequencing techniques provide in-depth data on how the transcripts are expressed and regulated and in this case shed light on how innate immunity responds to different stimuli. Acute Hepatopancreatic Necrosis Disease (AHPND) caused by Vibrio parahaemolyticusproducing Pir toxin (VPAHPND) is a current severe bacterial disease in shrimp. Suppression subtractive hybridization (SSH) was used to identify differentially expressed genes (DEGs) in hepatopancreas and hemocyte of VPAHPND-challengedPenaeus vannamei. The hemocyaninand Vago5 were found as up-regulated genes in hepatopancreas and hemocyte of VPAHPND-infectedP. vannamei, respectively. Their functions in shrimp immunity against VPAHPNDinfection were then characterized. The native …

Functional Characterization Of Inhibitor Of Kappa B Kinase In Black Tiger Shrimp Penaeus Monodon Antiviral Signaling Pathway, Zittipong Nhnhkorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

The IKK-NF-κB signaling cascade is one of the crucial responsive mechanisms in inflammatory and immune responses. The key kinase proteins called inhibitor of kappa B kinases (IKKs) serve as the core elements involved in cascade activation. Here, the complete open reading frames of IKK homologs including PmIKKβ, PmIKKε1 and PmIKKε2, from the black tiger shrimp Penaeus monodon were identified and characterized for their functions in shrimp antiviral responses. The PmIKK transcripts were widely expressed in various examined tissues and the PmIKKε protein was detected in all three types of shrimp hemocytes. Only the PmIKKε1 and PmIKKε2 were responsive to white …

การพัฒนาแบบจำลองเซลล์ลำไส้ของมนุษย์บนกระดาษที่มีการดัดแปรพื้นผิวและต้นแบบไบโอเซนเซอร์ไร้สายสำหรับตรวจวัดการเจริญของจุลชีพก่อโรค, ปัณณวิชญ์ ถิรบวรกิจพิธาน

Chulalongkorn University Theses and Dissertations (Chula ETD)

วิทยานิพนธ์นี้เป็นการนำเสนองานวิจัย การพัฒนาวิธีการใหม่เพื่อควบคุมและเฝ้าระวังโรคติดเชื้อ โดยประกอบด้วยเนื้อหาสำคัญสองส่วน ได้แก่ (i) การพัฒนาแบบจำลองเซลล์ลำไส้ของมนุษย์ที่เพาะเลี้ยงบนกระดาษที่มีการดัดแปรพื้นผิว เพื่อใช้ประโยชน์ในการศึกษากลไกการบุกรุกของเชื้อจุลชีพก่อโรคในระบบทางเดินอาหาร และ (ii) การพัฒนาต้นแบบไบโอเซนเซอร์แบบไร้สายเพื่อการตรวจติดตามการเจริญของเชื้อจุลชีพก่อโรค โดยในส่วนแรก เซลล์ลำไส้ของมนุษย์ HT-29 จำนวน 200,000 เซลล์ ถูกเพาะเลี้ยงในบริเวณชอบน้ำของกระดาษกรอง Whatman No.1 โดยกระดาษถูกดัดแปรพื้นผิวด้วยสารแมทริกซ์นอกเซลล์ (Extracellular matrix: ECM) ชนิดต่าง ๆ ได้แก่ Matrigel, Collagen-1 และ Laminin พื้นที่เพาะเลี้ยงเซลล์มีขนาด 12.56 ตารางมิลลิเมตร ภายใต้สภาวะที่เหมาะสม เซลล์ HT-29 ที่ถูกเพาะเลี้ยงบนกระดาษ มีชีวิตรอดได้ถึง 28 วัน และแสดงลักษณะของเซลล์ที่เจริญเต็มที่ โดยมีการแสดงออกของวิลไล (villi) ที่ผิวเซลล์ด้านบน (apical) และมีการแสดงออกของโปรตีน ZO-1 ซึ่งแสดงถึงเซลล์มีการสร้างไทต์จังก์ชันเกิดขึ้น จากการใช้สารเชื่อมพันธะสำหรับเชื่อมพันธะ ECM แต่ละชนิด พบว่าเมื่อใช้สารเจนิพินในการเชื่อมพันธะ เซลล์มีชีวิตรอดทั้งหมด (100 -112.8%) ในขณะที่มีเพียง 1.1 - 67.3 % ของเซลล์รอดชีวิต หากใช้สารกลูตารัลดีไฮด์ในการเชื่อมพันธะ แต่การใช้สารเชื่อมพันธะทั้งสองชนิด ทำให้เซลล์ไม่สามารถแบ่งตัวมีรูปร่างแบบสามมิติได้ เมื่อสังเกตด้วย SEM เซลล์มีลักษณะแบน การดัดแปรพื้นผิวกระดาษด้วยสาร ECM ชนิด Matrigel ส่งผลให้เซลล์มีชีวิตรอดมากที่สุดและสาร ECM ชนิด Laminin ทำให้เซลล์เกิดการแปรสภาพ (cell differentiation) ได้ดีที่สุด งานวิจัยส่วนที่ 2 เป็นการพัฒนาไบโอเซนเซอร์ไร้สายสำหรับติดตามการเจริญของเชื้อจุลชีพก่อโรค ได้แก่ เชื้อ Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus gordonii และ Candida albicans พบว่าเชื้อดังกล่าวสามารถสร้างไบโอฟิล์มบนผิวของขั้วไฟฟ้าคาร์บอนอสัณฐาน (glassy carbon electrode) และสามารถให้ค่าศักย์ไฟฟ้าที่เป็นลบได้ …