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Characterization Of Metronidazole- And Vancomycin-Resistant Clinical Isolates Of Clostridium Difficile, Chioma Odo

Dissertations and Theses (Open Access)

Characterization of Metronidazole- and Vancomycin-Resistant Clinical Isolates of Clostridium difficile

Chioma Odo, MS.

Supervisory Professor: Charles Darkoh, Ph.D.

ABSTRACT

The incidence of C. difficile infections (CDI) has been increasing at an alarming rate. This was precipitated by the emergence of strains with increased virulence, disease severity, and high recurrence rates. These strains also exhibit high propensity for resistance to antibiotics such as fluoroquinolones and beta lactams, which has made the treatment of CDI very challenging. Currently, metronidazole and vancomycin are the most commonly used drugs for the treatment of primary CDI. Metronidazole is used for the treatment of mild to …

Tumor Immunotherapy: Mechanisms Of Acquired Resistance And Characterization Of Immune Related To Xicities, Ashvin Jaiswal

Dissertations and Theses (Open Access)

Tumor immunotherapy has shown very promising clinical benefit across an array of cancers; however, two major challenges remain unresolved in the field. First, many patients do not respond to therapy at all or relapse after a period of remission. Second, there are often dose-limiting immune related adverse effects associated with immunomodulation.

In order to understand the mechanisms employed by tumors to evade immunotherapeutic responses, we established a murine model of melanoma designed to elucidate the molecular mechanisms underlying immunotherapy resistance. Through multiple in vivo passages, we selected a B16 melanoma tumor line that evolved complete resistance to combination blockade of …

Vitamin E Status Is Inversely Associated With Risk Of Incident Tuberculosis Disease Among Household Contacts, Omowunmi Aibana, Molly F Franke, Chuan-Chin Huang, Jerome T Galea, Roger Calderon, Zibiao Zhang, Mercedes C Becerra, Emily R Smith, Carmen Contreras, Rosa Yataco, Leonid Lecca, Megan B Murray

Faculty, Staff and Student Publications

BACKGROUND: Few studies have previously assessed how pre-existing vitamin E status is associated with risk of tuberculosis (TB) disease progression.

OBJECTIVE: We evaluated the association between baseline plasma concentrations of 3 vitamin E isomers (α-tocopherol, γ-tocopherol, and δ-tocopherol) and TB disease risk.

METHODS: We conducted a case-control study nested within a longitudinal cohort of household contacts (HHCs) of pulmonary TB cases in Lima, Peru. We defined cases as HHCs who developed active TB disease ≥15 d after the diagnosis of the index patient, and we matched each case to 4 control cases who did not develop active TB based on …

A License To Kill: Understanding Natural Killer Cell Licensing To Fight Cancer, Jolie Schafer

Dissertations and Theses (Open Access)

Natural killer (NK) cell education is an essential developmental process for NK cell effector function, that renders some NK cells “licensed” and others “unlicensed” (with heightened or lowered effector function potential, respectively) against tumor and targets lacking self-molecules. However, the underlying mechanisms responsible for the heightened effector responses of licensed cells remain unknown. Using NK cells derived from humans and expanded ex vivo we performed high-throughput protein expression analysis, and identified multiple proteins that are differentially regulated in licensed and unlicensed human NK cells before and after inhibition by killer-cell immunoglobulin-like receptors (KIRs) and activation by the NKp46 natural cytotoxicity …

Mechanism Of Candida Albicans Biofilm And Virulence Inhibition By A Bacterial Secreted Factor, Carrie Graham

Dissertations and Theses (Open Access)

The human microbiome is a diverse polymicrobial population comprised of both fungi and bacteria. Perturbations of the normal microbiome can have a profound impact on health, including the development of infections. Exploitation of these polymicrobial interactions has the potential to provide novel treatment and prevention strategies for infectious diseases. Enterococcus faecalis, a Gram-positive bacterium, and Candida albicans, a polymorphic fungus, occupy overlapping niches as ubiquitous constituents of the gastrointestinal and oral microbiome. Both species are also amongst the most important and problematic, opportunistic nosocomial pathogens and are often co-isolated during infection. Surprisingly, these two species antagonize each other’s …

Memory Potential, Molecular Characterization, And Translational Applications Of The Novel Theo/Tceo T Cell Phenotype, Todd Bartkowiak, Todd Bartkowiak

Dissertations and Theses (Open Access)

T cells comprise a substantial arm of the immune system and are exquisitely adapted to combat pathogens and tumors. The inflammatory environment largely dictates the nature of T cell response. A hallmark of T cell-mediated immunity is formation of immunological memory; the ability to respond more potently to re-encounter with pathogens. The immune system is also capable of recognizing tumors as foreign, much like viral or bacterial pathogens. Tumors have evolved, though, to generate an immunosuppressive environment to avoid destruction. The field of immunotherapy seeks to overcome immune suppression, in part by targeting T cell co-receptors on the cell surface …

Dynamic Assessment Of Nk Cell Interactions With Pediatric Tumor Cells To Predict Response To Immunotherapy, Arianexys Aquino Lopez

Dissertations and Theses (Open Access)

Due to Natural Killer (NK) cells’ capacity to target tumor cells without prior sensitization, adoptive NK cell therapy represents a promising immunotherapy approach for pediatric cancer patients. Our laboratory has developed an NK cell expansion protocol that generates large quantities of NK cells for therapeutic infusion. Given that NK cells are heterogeneous, with variable receptor expression and potential to target tumor cells, the purpose of my study was to determine whether subpopulations of NK cells with enhanced anti-tumor potential could be identified for increased potency of the NK cell infusion product. In addition, we previously showed that our expanded NK …

Membrane Bound Il21 Promotes Natural Killer Cell Expansion Through Mir 124-3p Mediated Regulation, Anitha Somanchi

Dissertations and Theses (Open Access)

Natural Killer (NK) cells are cells of the innate immune system that act as first line of defense against viral infections and participate in tumor immune surveillance. NK cells do not cause graft versus host disease (GvHD), or require prior antigen exposure to exert anti-tumor activity, hence are an attractive choice for immunotherapy applications. Owing to small numbers of NK cells in peripheral blood (1-32%, with a 6% median), ex vivo expansion of NK cells is critical for NK cell adoptive immunotherapy, various expansion platforms have been explored over the decades. We developed a robust platform for ex vivo expansion …

Impact Of Vitamin A And Carotenoids On The Risk Of Tuberculosis Progression, Omowunmi Aibana, Molly F Franke, Chuan-Chin Huang, Jerome T Galea, Roger Calderon, Zibiao Zhang, Mercedes C Becerra, Emily R Smith, Alayne G Ronnenberg, Carmen Contreras, Rosa Yataco, Leonid Lecca, Megan B Murray

Faculty, Staff and Student Publications

BACKGROUND: Low and deficient levels of vitamin A are common in low- and middle-income countries where tuberculosis burden is high. We assessed the impact of baseline levels of vitamin A and carotenoids on tuberculosis disease risk.

METHODS: We conducted a case-control study nested within a longitudinal cohort of household contacts (HHCs) of pulmonary tuberculosis case patients in Lima, Peru. We defined case patients as human immunodeficiency virus (HIV)-negative HHCs with blood samples in whom tuberculosis disease developed ≥15 days after enrollment of the index patient. For each case patient, we randomly selected 4 controls from among contacts in whom tuberculosis …

Study Of Regulated Cell Death In Two Systems: Pd-1 In Natural Killer Cells And Rip3 In Neurons, Yu Huang

Dissertations and Theses (Open Access)

Cell death is not only an essential phenomenon in normal development and homeostasis, but also crucial in various pathologies. It is now clear that many types of cell death can be regulated by pharmacological or genetic interventions. These were largely achieved by identifying the molecular mechanisms underlying the regulated cell death (RCD). While in the immune system, RCD needs to be facilitated to help the clearance of pathogens and tumors, in healthy cells, especially the terminally differentiated neurons in the nervous system, it is more desirable to protect cells from dying due to stress under pathological conditions. Thus, understating the …

“It Takes A (Healthy) Village To Raise A Child:” A Case For Integrating Public Health And Social Work Research To Eliminate Health Disparities, Heather H. Goltz

Journal of Family Strengths

Issue Editor, Heather H. Goltz, introduces Volume 17, Issue 1 of the Journal of Family Strengths.

Improving Nk Cell Therapy For Osteosarcoma, Jennifer Foltz

Dissertations and Theses (Open Access)

Osteosarcoma (OS) is the most common primary bone tumor. Despite new treatment options, 5-year survival for metastatic OS has remained at only 30% for the last 30 years. Adoptive transfer of Natural Killer (NK) cells holds promise for a new, non-toxic therapy for OS. NK cells are part of the innate immune system and readily kill metastatic and chemotherapy-resistant OS in vitro and in murine models. However, there is little data regarding their efficacy in animal models with an intact immune system. In addition, the OS tumor microenvironment is highly suppressive, producing TGFβ which impedes NK cell killing of solid …

Reducing Antibiotic Use In Pediatric Upper Respiratory Infection: A Multifaceted Parent-Clinician Approach, Sydnee H. Lucas Dnp, Aprn, Sydney Thompson Dnp, Arnp, Fnp-Bc

Journal of Nursing & Interprofessional Leadership in Quality & Safety

The goal of this QI initiative was to decrease inappropriate antibiotic for the treatment of pediatric upper respiratory infection (URI) in the retail clinic setting. The approach included the use of a protocol to treat viral upper respiratory illness, a visual aid decision-making tool for guideline adherence, prescription pad for nonprescription remedies, and shared decision-making techniques for providers to involve patients and parents in management plans regarding nonprescription remedies, supportive treatment, and signs and symptoms that would warrant a return visit. An improvement trend during the first 3 months of the initiative showed a shift in antibiotic avoidance from a …

A Novel Bioinformatic Approach To Understanding Addiction, Latifa F. Jackson

Journal of Family Strengths

Finding the genetic markers that influence complex, multigenic substance addiction phenotypes has been an area of significant medical study. Understanding complex disease traits like addiction has been hampered by the lack of functional insights into novel variants to the human genome. We hypothesized that gene location plays a role in functional genomic neighborhoods.

To test whether there is a relationship between opiate, dopamine, and GABA disease and population allele frequencies, we used genes obtained from addiction literature curated by the National Center for Biotechnology Information (NCBI). These addiction and metabolism focused search terms generated opiate, dopamine, and GABA addiction results …

Illness Severity Among Non-English, Non-Spanish Speaking Patients In A Public Emergency Department, Malford T. Pillow M.D., M.Ed., Thomas Ence M.D., Tyler Dirvonas M.D., William F. Peacock M.D., Dick Kuo M.D.

Journal of Family Strengths

Background: Patients with limited English proficiency (LEP) have poor health outcomes compared to English proficient patients. Most studies on language proficiency and health disparities focus on Spanish.

Objective: This study examines whether non-Spanish speaking LEP patients experience greater disparities than Spanish speaking LEP patients by comparing disease acuity and language proficiency in an emergency department.

Design: This is a retrospective case-control study from November 2010 to February 2012 comparing differences between non-English non-Spanish (NENS) speaking patients to English speaking patients with differences between Spanish speaking and English speaking patients.

Main outcomes: Primary endpoints include the emergency severity index …

Tumor-Cell Derived Inhibin, Beta A Is Essential For Adrenergic Effects On Fibroblast Activation, Archana Sidalaghatta Nagaraja

Dissertations and Theses (Open Access)

Objectives: Catecholamine-mediated effects driven by elevated adrenergic signaling are known to increase tumor growth and metastasis by direct effects on tumor cells. However, knowledge of effects of adrenergic signaling on other cells such as cancer-associated fibroblasts (CAFs) within the tumor microenvironment is limited. We hypothesize that adrenergic signaling and norepinephrine can accelerate the induction of CAF-phenotype to promote inflammation and metastasis.

Methods: Ingenuity Pathway Analysis and NetWalker were used to assess gene expression data from patients with known CESD (Center for Epidemiological Studies-Depression)-score alongside microdissected CAFs from primary ovarian cancer. Tumor samples from mice exposed to daily restraint-stress or non-stressed …

Developing Novel Approaches To Improve Response To T Cell Based Cancer Immunotherapy, Rina M. Mbofung

Dissertations and Theses (Open Access)

Recently, T cell based immunotherapies have moved to the forefront of cancer immunotherapy with the success of Adoptive T cell therapy (ACT) and Immune checkpoint blockade.ACT, where patients are treated with tumour infiltrating T cells (TILs), conferred a clinical response rate of ~50%. Treatment with anti-CTLA4 and anti –PD1 therapy, conferred response rates of up to 50%, greatly improving the overall survival of patients with advanced melanoma amongst other cancer types. Despite the encouraging outcomes, there are relatively low response rates coupled with the delay of weeks to months before tumour shrinkage can be appreciated. Thus, understanding what tumour intrinsic …

Statistical Methods For Assessing Structural Change In Human & Microbial Genomes, Xuan Zhu

Dissertations and Theses (Open Access)

Genetic sequencing has been recognized as an effective approach to accurately address biological problems, such as clinical detection of disease, mutation discovery, and targeting specific biomarkers associated with complex diseases. Compared with conventional Sanger sequencing, next-generation sequencing costs much less due to massively parallel high-throughput sequencing. However, due to large numbers of short read sequences, the accuracy of high-throughput sequencing data remains a challenge in that the data obtained from next-generation sequencing often has higher error rates, which may impact downstream genomic analysis. Even if the downstream genomic analysis performs well, the quality of the result will still be impacted …

Peptide Vaccine Formulation Controls The Duration Of Antigen Presentation And Magnitude Of Tumor‐Specific Cd8+ T Cell Response, Hiep Khong

Dissertations and Theses (Open Access)

Despite remarkable progresses in vaccinology, therapeutic cancer vaccines have not achieved their full potential. We previously showed that the duration of antigen presentation critically affected the quantity and quality of T cell response and subsequent anti‐tumor efficacy. Here we describe L‐tyrosine amino acid‐based microparticles as a novel peptide vaccine adjuvant for the induction of tumor‐specific T cells. L‐tyrosine microparticles did not induce inflammasome activation, but instead extended antigen presentation time. The consequent prolongation in antigen presentation translated into prolonged T cell proliferation and superior numbers and anti‐tumor function of vaccination‐induced CD8+ T cells. Indeed, prolonging antigen presentation by repeated injection …

Stromal Fibroblasts Restrain The Rate Of Colon Cancer Progression And Metastasis By Suppressing Regulatory T Cells And Colon Cancer Stem Cells, Changsoo Kwak

Dissertations and Theses (Open Access)

The initiation, progression, and metastasis of tumors involve not only cancer cells, but also the tumor microenvironment, which consists of immune or inflammatory cells, fibroblasts, endothelial cells, and extracellular matrix components (ECM). Fibroblasts are ubiquitous stromal cells that can influence other neighboring cell types through the secretion of chemokines, cytokines, ECM, ECM remodeling enzymes, and other metabolites. Myofibroblasts are a distinct subtype of fibroblasts characterized by expression α-smooth muscle actin (αSMA). These cells are a dominant component of the microenvironment, and a FSP1 and FAP could be a different clone of fibroblasts. Myofibroblasts also have been known to contribute to …

Characterization Of The Role Of The Pkm101-Encoded T4ss Outer Membrane Core Complex In Substrate Transfer, Pilus Biogenesis, And Recipient Cell Contact, Jay E. Gordon

Dissertations and Theses (Open Access)

The bacterial type IV secretion systems (T4SS) encoded on the Escherichia coli pKM101 and R388 conjugative plasmids and the Agrobacterium tumefaciens virB operon are composed of 12 subunits arranged in an architecturally similar fashion. Structural studies of the T4SS from R388 (Trw_R388) highlighted the presence of a distinct outer membrane core complex (OMCC) and inner membrane complex (IMC) joined together by a central stalk. This thesis is focused on the development of the pKM101 model system and the role of an OMCC cap region formed by alpha helical antenna projections (AP) found in VirB10 and TraF_pKM101. …

Ms171: Interview With Margaret Carter Mcneese, Margaret Carter Mcneese M.D., Houston Academy Of Medicine-Texas Medical Center Library

Texas Medical Center - Women's History Project

An oral history interview with Margaret Carter McNeese about her career in the Department of Pediatrics at the Univeristy of Texas Health Science Center at Houston Medical School.

Dr. McNeese’s undergraduate years were spent at Mary Baldwin College in Staunton, Virginia. She went to medical school at The University of Texas Medical Branch at Galveston, where she began her career as a physician and pediatrician. She has been a recipient of many awards, among them the UT Health Science Center at Houston’s President’s Award for Mentoring Women; the Catholic Charity Guild Award for service at the San Jose Clinic, the …

Ms171: Interview With Millicent Goldschmidt, Millicent Goldscmidt Ph.D., Houston Academy Of Medicine-Texas Medical Center Library

Texas Medical Center - Women's History Project

An oral history interview with Millicent Goldschmidt about her career at University of Texas Health Science Center at Houston (UTHealth) where she has held faculty positions in the Department of Diagnostic and Biomedical Sciences at UTHealth School of Dentistry, UTHealth Medical School, and the Graduate School of Biomedical Sciences.

Millicent Edna Goldschmidt, Ph.D., came to the Texas Medical Center after an educational journey that included parental objections and a husband’s ethical concerns about research.

Once in Houston, her professional journey took her to almost every institution in the Texas Medical Center – from Baylor College of Medicine to The University …

Risk Factors For Poor Multidrug-Resistant Tuberculosis Treatment Outcomes In Kyiv Oblast, Ukraine, Omowunmi Aibana, Mariya Bachmaha, Viatcheslav Krasiuk, Natasha Rybak, Timothy P Flanigan, Vasyl Petrenko, Megan B Murray

Faculty, Staff and Student Publications

BACKGROUND: Ukraine is among ten countries with the highest burden of multidrug- resistant TB (MDR-TB) worldwide. Treatment success rates for MDR-TB in Ukraine remain below global success rates as reported by the World Health Organization. Few studies have evaluated predictors of poor MDR-TB outcomes in Ukraine.

METHODS: We conducted a retrospective analysis of patients initiated on MDR-TB treatment in the Kyiv Oblast of Ukraine between January 01, 2012 and March 31st, 2015. We defined good treatment outcomes as cure or completion and categorized poor outcomes among those who died, failed treatment or defaulted. We used logistic regression analyses to identify …

Clinical Risk Factors For Infective Endocarditis In Staphylococcus Aureus Bacteremia, Vincent Bryan D Salvador, Bikash Chapagain, Astha Joshi, Debra J Brennessel

The Texas Heart Institute Journal

Crucial to the management of staphylococcal bacteremia is an accurate evaluation of associated endocarditis, which has both therapeutic and prognostic implications. Because the clinical presentation of endocarditis can be nonspecific, the judicious use of echocardiography is important in distinguishing patients at high risk of developing endocarditis. In the presence of high-risk clinical features, an early transesophageal echocardiogram is warranted without prior transthoracic echocardiography.

The purpose of this study was to investigate the clinical risk factors for staphylococcal infective endocarditis that might warrant earlier transesophageal echocardiography and to describe the incidence of endocarditis in cases of methicillin-resistant and methicillin-sensitive Staphylococcus aureus …

Annual Report 2016-2017, Houston Academy Of Medicine - Texas Medical Center Library

Annual Reports: 1943 - Present

This file contains the Annual Report for the library from 2016-2017.

Patient Predictors Of Poor Drug Sensitive Tuberculosis Treatment Outcomes In Kyiv Oblast, Ukraine, Omowunmi Aibana, Andrej Slavuckij, Mariya Bachmaha, Viatcheslav Krasiuk, Natasha Rybak, Timothy P Flanigan, Vasyl Petrenko, Megan B Murray

Faculty, Staff and Student Publications

Background: Ukraine has high rates of poor treatment outcomes among drug sensitive tuberculosis (DSTB) patients, while global treatment success rates for DSTB remain high.

We evaluated baseline patient factors as predictors of poor DSTB treatment outcomes.

Methods: We conducted a retrospective analysis of new drug sensitive pulmonary TB patients treated in Kyiv Oblast, Ukraine between November 2012 and October 2014. We defined good treatment outcomes as cure or completion and poor outcomes as death, default (lost to follow up) or treatment failure. We performed logistic regression analyses, using routine program data, to identify baseline patient factors associated with poor outcomes. …

A Rare Case Of Erythema Elevatum Diutinum Presenting As Diffuse Neuropathy, G H. Nguyen, E L. Guo, D Norris

Faculty, Staff and Students Publications

No abstract provided.

Influence Of Maternal Breast Milk Ingestion On Acquisition Of The Intestinal Microbiome In Preterm Infants, Katherine E Gregory, Buck S Samuel, Pearl Houghteling, Guru Shan, Frederick M Ausubel, Ruslan I Sadreyev, W Allan Walker

Faculty, Staff and Students Publications

BACKGROUND: The initial acquisition and early development of the intestinal microbiome during infancy are important to human health across the lifespan. Mode of birth, antibiotic administration, environment of care, and nutrition have all been shown to play a role in the assembly of the intestinal microbiome during early life. For preterm infants, who are disproportionately at risk of inflammatory intestinal disease (i.e., necrotizing enterocolitis), a unique set of clinical factors influence the establishment of the microbiome. The purpose of this study was to establish the influence of nutritional exposures on the intestinal microbiome in a cohort of preterm infants early …

Consensus Paper: Cerebellar Development, K Leto, M Arancillo, Ebe Becker, A Chiang, Et Al.

Faculty, Staff and Students Publications

The development of the mammalian cerebellum is orchestrated by both cell-autonomous programs and inductive environmental influences. Here, we describe the main processes of cerebellar ontogenesis, highlighting the neurogenic strategies used by developing progenitors, the genetic programs involved in cell fate specification, the progressive changes of structural organization, and some of the better-known abnormalities associated with developmental disorders of the cerebellum.