Pharmacology, Toxicology and Environmental Health Commons^™

Patholigical And Prognostic Role Of Mdig In Pancreatic Cancer, Srinivas Ashok Kumar

Wayne State University Theses

Pancreatic cancer is a highly aggressive malignant disease having very limited therapeutic options that ultimately results in its poor prognosis. It is still elusive on the etiology and tumorigenic mechanisms of pancreatic cancer. In the present report, we provide evidence showing involvement of the mineral dust-induced gene (mdig) in the pathogenesis and prognosis of the pancreatic cancer. Using immunohistochemistry approach on human pancreatic cancer tissue microarray, we found differential expression of mdig in pancreatic adenocarcinoma and normal pancreas. Based on the staining intensities of mdig in these tissue samples, we found that 12% of the cancer tissues were strongly positive …

The Role Of Line-1 Transposable Element In Methamphetamine Neurotoxicity In The Neurogenic Zones, Dongyue Yu

Wayne State University Theses

Methamphetamine (METH) is a widely abused psychostimulant, which can cause neurotoxicity in the striatum and hippocampus. Several epigenetic changes were identified after binge METH exposure, including histone modification, DNA methylation, and changes in miRNA levels. We have shown that binge METH increases expression and activity of Long INterspersed Element (LINE-1), a transposable element, in doublecortin-positive neurons within rat neurogenic zones [1]. The goal of the present study was to identify which type(s) of cells show increases in LINE-1 following binge METH exposure, and determine whether binge METH-induced increases in LINE-1 are associated with cell death. To achieve this goal, male …

An Evaluation Of Endocrine Disrupting Effects Of Emerging Contaminants Using Daphnia Pulex And Danio Rerio, Lakshmi Neha Reddy Alla

Wayne State University Theses

The limit of the availability of water is based on two factors, scarcity and quality. Conserving and protecting our water resources one of the most critical issues facing humanity as we struggle to deal with contaminated lakes and rivers and climate change. The main aim of this study is to examine toxicity of known water contaminants on aquatic model organisms and be able to develop methodology that will enable the characterization of endocrine disrupting potential of water samples with unknown contaminants. Both the category of water contaminants known as pharmaceuticals, personal care products that are known as PPCPs and other …

Metformin, Glucotoxicity And Islet Dysfunction, Sartaj S. Baidwan

Wayne State University Theses

METFROMIN, GLUCOTOXICITY AND ISLET DYSFUNCTION

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SARTAJ BAIDWAN

MAY 2017

Advisor: Dr. Anjaneyulu Kowluru

Major: Pharmaceutical Sciences

Degree: Master of Science

Glucotoxicity is the leading cause for β-cell dysfunction [e.g., defective glucose-stimulated insulin secretion] in Type 2 Diabetes [T2DM]. Recent studies from our lab have shown sustained Rac1 activation leading to the activation of downstream signaling steps including stress kinase [p53, p38MAPK] activation and mitochondrial dysregulation [caspase-3 activation] in pancreatic islet beta-cells exposed to glucotoxic [HG] conditions [20 mM; 24 hrs]. Metformin [MF] is an oral anti-diabetic drug that is being widely prescribed to T2DM. MF works by suppressing hepatic …

Endocrine-Disrupting Properties Of Pharmaceuticals And Personal Care Products (Ppcps): An Evaluation Using Aquatic Model Organisms, Manahil Monshi

Wayne State University Theses

Thousands of chemicals have introduced into the environment as a result of human activity since the industrial revolution, and the U.S. Government Accountability Office has estimated that as many as 1,500 new chemical entities are synthesized each year ("Key Issues: Toxic Chemicals - High Risk Issue," 2017). Many of these chemicals are now found in surface water and ground water and can have detrimental effects on environmental health and on human health. This anthropogenic contamination has resulted in the labeling of the diverse array of chemicals found in water, which are not routinely monitored or regulated, as contaminants of emerging …

Protein Phosphatase 2a Function And Regulation In Insulin Resistant Human Skeletal Muscle Cells, Shukurat Sulaiman

Wayne State University Theses

Protein Phosphatase 2A (PP2A), a major serine/threonine phosphatase involved in insulin signaling pathway, plays a critical role in the development of insulin resistance and type 2 diabetes (T2D), which is characterized with hyperinsulinemic hyperglycemic condition. Moreover, majority of the glucose disposal takes place in the skeletal muscle which is also the main tissue responsible for insulin resistance. The catalytic subunit of PP2A (PP2Ac) can interact with multiple regulatory subunits and other regulatory proteins as well as substrates. These interactions are important for maintain normal PP2A function and subsequent cell signaling. We hypothesized that hyperinsulinemic hyperglycemic condition and insulin stimulation would …

Redox Responsive Cerium Oxide Nanoparticles And Cd44 Targeted Nanomicelles For Selective Cancer Therapy, Zhaoxian Wang

Wayne State University Theses

Redox-responsive cerium oxide nanoparticles (CNPs) can play a versatile role in cancer therapy due to their ability to induce oxidative stress under proper pH conditions. Hyaluronic acid micelles with a high affinity to CD44 receptor which achieved more cytotoxicity towards cancer cells. The polymer-coated CNPs and HA-SMA-TPGS-CDF nanomicelles were developed for cancer therapy. The results showed that the toxicity of CNPs in tumor cells was mediated by the pro-oxidant property of CNPs under relative low pH conditions (pH~6.5) of the tumor microenvironment whereas CNPs play a (cytoprotective) anti-oxidant role, scavenging reactive oxygen species and reducing oxidative stress under normal pH …

Design And Synthesis Of Enzalutamide-Isothiocyanate Hybrid Drug As Anti-Prostate Cancer Agent, Siyu Ou

Wayne State University Theses

Isothiocyanate (ITC), such as sulforaphane (SFN), is an active metabolite of dietary glucosinolate from cruciferous vegetables. SFN-rich extracts have been recently tested in recurrent prostate cancer (PCa) patients and notably prolonged PSA doubling time without Grade 3 adverse events. One of the anti-PCa mechanisms of SFN is to inhibit HDAC6, which further triggering androgen receptor (AR) degradation. We have incorporated ITC to the chemical scaffold of enzalutamide (Enz) to create Enz-ITC hybrid molecules with an intention to intracellularly deliver ITC to AR-Hsp90-HDAC6 complex and therefore improving anti-PCa efficacy of both parental drugs. Two Enz-ITCs and one Enz-ITC N-acetyl cysteine (NAC) …

Targeted Delivery Of Nrf2 Sirna Using Modular Polymeric Micellar Nanodelivery System For Efficient Target Gene Knockdown In Hepatocellular Carcinoma, Shaimaa Mohamed Ibrahim Yousef

Wayne State University Theses

Tumor selective drug delivery as well as chemotherapy associated multi drug resistance (MDR) pose tremendous hurdles for effective cancer therapy. In this regard, designing multifunctional nanocarriers loaded with drug/gene payloads and engineered with tumor targeting ligands can serve as a modular platform for targeted drug/gene delivery. In this study we undertook the synthesis of a self-assembling block copolymer constructed using poly(styrene-co-maleic anhydride, partial iso-octyl ester) (SMAPIE) and branched polyethylenimine (PEI) as building blocks and evaluated its micelle forming ability, siRNA complexation and siRNA delivery potentials. In addition, we engineered galactosamine decorated nanomicelles using modular “click” chemistry based approaches for evaluating …

Dendrimer-Coated Iron Oxide Theranostic Nanoparticles For Cancer Imaging And Therapy, Duy Khanh Luong

Wayne State University Theses

The bleak prognosis for patients diagnosed with metastatic cancer along with the low therapeutic efficacy and the recurrence of cancer in conventional chemotherapy are prompting clinical medicine to adopt a new strategy to detect cancer in early stage and to deliver the anticancer drugs specifically to tumor site to enhance therapeutic efficiency and minimize side effects. The aim of this study is to design a theranostic nanocarrier consisting of iron oxide nanoparticles (SPIONs) for magnetic resonance imaging (MRI) and Polyamidoamine dendrimers conjugated with folic acid (FA-PAMAM) for active targeted delivery of a highly potent but extremely lipophilic anticancer compound 3,4-difluorobenzylidene …

Development Of A Dreissena Bioassay To Assess The Toxicity Of Contaminants Across Two Life-History Stages, Caroline Joyce Addis

Wayne State University Theses

Dreissenid mussels (Dreissena polymorpha and D. bugensis) have rapidly become widespread and ubiquitous in North America since their introduction into the Great Lakes in the 1980s. The resulting environmental and economic impacts of their invasion have been extensive, negatively affecting biodiversity and costing millions of dollars in control efforts and damage to power generation and water treatment facilities. Although dreissenids are often associated with negative impacts, they may present a practical tool for toxicology studies. The typically sessile behavior of the benthic adults coupled with the planktonic nature of the veligers allow for a more complete evaluation of water quality …

Impact Of Cefazolin Co-Administration With Vancomycin To Reduce Development Of Vancomycin Intermediate Staphylococcus Aureus, Nivedita Birbahadur Singh

Wayne State University Theses

IMPACT OF CEFAZOLIN CO-ADMINISTRATION WITH VANCOMYCIN TO REDUCE DEVELOPMENT OF VANCOMYCIN INTERMEDIATE STAPHYLOCOCCUS AUREUS

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NIVEDITA B SINGH

August 2106

Advisor: Dr. Michael J. Rybak

Major: Pharmaceutical sciences

Degree: Masters of Science

Objective: Development of resistance in S. aureus has been a big concern in the treatment of infections caused by the organism. The line of therapy used today has a disadvantage of slowly developing cross-resistance for antibiotics such as DAP secondary to prior VAN exposure. Therefore, alternative therapy is needed to prevent the emergence of VAN resistance and cross-resistance to other antibiotics. The primary aim of this experiment is …

The Role Of E3 Ligase Parkin In Trafficking Of Monoamine Storage Vesicles In Rat Model Of Methamphetamine Neurotoxicity, Heli Dineshchandra Chauhan

Wayne State University Theses

Methamphetamine (METH), a psychostimulant, is a widely used drug of abuse. METH is toxic to dopaminergic (DAergic) and serotonergic (5-HT) nerve terminals in the striatum when administered at high doses. METH releases Dopamine (DA) from vesicular monoamine transporter 2 (VMAT2) containing synaptic vesicles and induces oxidative stress by auto-oxidation of DA. The VMAT2 plays a neurprotective role by sequestering cytoplasmic DA into vesicles for storage and protection from auto-oxidation. It has previously been shown that METH toxicity is associated with impaired VMAT2 trafficking and oxidative damage to the E3 ligase parkin. CDCrel1, a protein found to inhibit exocytosis, is regulated …

Novel Protein Phosphatase 2a Complexes In Skeletal Muscle From Obese Insulin Resistant Human Participants, Divyasri Damacharla

Wayne State University Theses

Type 2 Diabetes is a metabolic disorder associated with insulin resistance and consequent high blood glucose levels. Maximum glucose disposal takes place in skeletal muscle and studying skeletal muscle insulin resistance is crucial. Protein Phosphatase 2A (PP2A) is one of the major serine/threonine phosphatases belonging to PhosphoProteinPhosphatase (PPP) family. It constitutes about 80% of all serine/threonine phosphatases. It is regulated by numerous regulatory subunits as well as other substrate molecules and post translational modifications. This alters their localization, activity and also its target molecules. Many evidences show the effect of insulin on PP2Ac and its abnormal regulation in conditions of …

Contaminants Of Emerging Concern: Effects Of Known Neuroactive Agents, Antibiotics, And Chemically Uncharacterized Photodegredates On Behavior And Physiology Of Daphnia Pulex, Vibhuti Matta

Wayne State University Theses

Emerging contaminants such as pharmaceuticals and personal care products (PPCPs), herbicides, pesticides, plasticizers, fire retardants, polycyclic aromatic hydrocarbons (PAHs), and other organic waste are increasingly being detected in surface water and ground water. These contaminants can enter into the environment through wastewater treatment plant effluent and agriculture runoff. Many of these emerging contaminants tend to be biologically active at very low concentrations, typically occur in water as part of complex mixtures, and may impact biota at concentrations not detected using traditional toxicity tests (e.g. LC 50 tests).

This study focuses on utilizing novel Daphnid optical bioassays to examine the toxicity …

Protein Ubiquitination In Primary Human Skeletal Muscle Cells Under Hyperinsulinemic Hyperglycemic Conditions, Majed Abdullah Alharbi

Wayne State University Theses

Ubiquitin proteasome system is a relatively newly discovered pathway for protein degradation. Many studies have successfully pointed out the critical functions that UPS plays in regulating many physiological processes. On the other hand, recent studies suggested that abnormal UPS activities might be involved in the pathophysiology of several disorders including type 2 diabetes. However, the specific changes in UPS during the development of insulin resistance and consequently T2D are still unclear.

UPS is composed of two major steps, a reversible ubiquitin conjugation to the targeted substrate followed by proteasomal degradation of the ubiquitinated proteins. In this study, we examined the …

A Retrospective Cohort Study Of High Prevalence Of St131 Among Extended Spectrum Β-Lactamase Producing E. Coli Among Inpatients In The Metropolitan Detroit Area, Pansy Awasthy

Wayne State University Theses

ABSTRACT

HIGH PREVALENCE OF ST131 AMONG EXTENDED SPECTRUM Β-LACTAMASE PRODUCING E. COLI AMONG INPATIENTS IN THE METROPOLITAN DETROIT AREA

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PANSY AWSTHY

2015

Advisor: Dr. Emily T. Martin

Major: Pharmaceutical Sciences

Degree: Master of Science

Objectives: E.coli ST131 multi-locus sequence type (MLST) has been associated with extended spectrum β-lactamase (ESBL) production, conferring antimicrobial resistance, with increased virulence and with healthcare-associated infection. The high prevalence of multidrug antimicrobial resistance in ESBL-producing ST131 E.coli infections creates unique challenges in the studying patient outcomes and analysis are required to study ST131 E.coli amongst a large population of ESBL-producers. Our objective was to determine …

Combination Of Photodynamic Therapy With Fenretinide And C6-Pyridinium Ceramide Enhances Killing Of Scc17b Human Head And Neck Squamous Cell Carcinoma Cells Via The De Novo Sphingolipid Biosynthesis And Mitochondrial Apoptosis, Nithin Bhargava Boppana

Wayne State University Theses

The ceramide generated via the de novo sphingolipid biosynthesis has been shown to regulate apoptosis and cell death. The de novo sphingolipid biosynthesis includes ceramide synthase (CERS)-dependent acylation of dihydrosphingosine, giving rise to dihydroceramide, which is then converted to ceramide by a desaturase-dependent reaction. The mitochondrial pathway of apoptosis, characterized by induction of Bax associated with mitochondria and cytochrome c release/redistribution. Bcl2, an anti-apoptotic protein blocks apoptosis by inhibiting Bax. Elucidating the role of de novo sphingolipid biosynthesis and mitochondrial apoptosis in PDT, PDT+4HPR and PDT+LCL29 could help in improving the effectiveness on these anti-cancer treatments. The objective of this …

Effect Of Metformin On Global Phosphorylation Profiles Of Primary Skeletal Muscle Cells Derived From Overweight/Obese Insulin Resistant Human Participants, Nishit Shah

Wayne State University Theses

Metformin is a drug from the biguanide class and it has been in use for the treatment of type 2 diabetes for a long time, and it can improve insulin sensitivity in skeletal muscle. However, the mechanism for metformin’s action is unclear. Phosphatases and kinases, and their subunits are the proteins required for dephosphorylation and phosphorylation of proteins in cells during various signaling pathways. Phosphorylation studies of proteins from primary cell culture derived from skeletal muscle tissue from obese/overweight insulin resistant participants will help to understand the regulation of phosphorylation in phosphatases and kinases by metformin.

In the current research, …

Exploring Novel Daptomycin Combinations With Β-Lactam Against Susceptible & Non-Susceptible Enterococcus Species, Animesh Raut

Wayne State University Theses

EXPLORING DAPTOMYCIN COMBINATION WITH β-LACTAM SYNERGY AGAINST SUSCEPTIBLE AND NON-SUSCEPTIBLE ENTEROCOCCI SPECIES

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ANIMESH RAUT

August 2015

Advisor: Dr. Michael J. Rybak

Major: Pharmaceutical sciences

Degree: Master of Science

Objective: Enterococcus faecalis and Enterococcus faecium are generally resistant to daptomycin and β-lactam antibiotics. However, documented in vitro data suggests synergy between several β-lactam antibiotics and daptomycin against resistant organisms. Primary goal of the study was to check various combinations of β-lactam antibiotics with daptomycin (DAP) and assess the potential of synergy and conclude which could be the superior combination. Study also evaluated potential of β-lactam antibiotics to enhance activity of …

Species - Dependent Cardiac And Motor Responses To Cholinergic Stimulation In Daphnia Pulex And Daphnia Magna, Bryan James Hannan

Wayne State University Theses

The role of acetylcholine (ACh) in regulating the activity of the heart and `feeding current' driven by the beating thoracic appendages of Daphnia pulex and Daphnia magna was evaluated using acetylcholinesterase inhibitors (AChE-I) and muscarinic receptor agonists. Single animals, tethered to a stainless steel pin, were tested in a watertight aquatic chamber that allowed free movement of appendages and swimming antennae. Heart contraction rate and the rate of thoracic appendage beating were quantified optically by measuring fluctuating changes in light-intensity caused by movement. Physostigmine, neostigmine, oxotremorine, pilocarpine as well as nicotine were used to study ACh and AChE. Atropine was …

Development And Evaluation Of Plga-S-S-Peg Micelles Coencapsulating Curcumin Difluorinated And Paclitaxel For Synergistic Therapeutic Efficacy, Lakshmi Deepika Cheemalakonda

Wayne State University Theses

ABSTRACT

DEVELOPMENT AND EVALUATION OF PLGA-S-S-PEG MICELLES COENCAPSULATING CURCUMIN DIFLUORINATED AND PACLITAXEL FOR SYNERGISTIC THERAPEUTIC EFFICACY

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LAKSHMI DEEPIKA CHEEMALAKONDA

August 2014

Advisor: Dr. Joshua Reineke Major: Pharmaceutical Sciences Degree: Master of Science

Solid tumors like pancreatic tumor has unique property of forming a dense desmoplastic layer around the tumor cells making it difficult for the drug to transport across this layer. Multi drug resistance is also one of the major limitation of chemotherapy. Therefore the aim of this project was to make PLGA-SS-PEG micelles encapsulating CDF and paclitaxel for synergistic cancer therapy. CDF was found to have 16-fold better …

Site-Directed Mutagenesis Of Conserved Amino Acids Residues In N5-Carboxyaminoimidazole Ribonucleotide Mutase: Converting N5-Cair Mutase Into Aminoimidazole Ribonnucleotide Carboxylase & Developing A High-Throughput Screening Assay For The Discovery Of N5-Carboxyaminoimidazole Ribonucleotide Mutase, Zhiwen Shi

Wayne State University Theses

The de novo purine biosynthesis pathway plays a critical role in providing new purines to the cell. Previous studies have shown differences between the human and bacterial pathways which suggests that pathway may be a potential target for antibiotic drug discovery. Three critical enzymes are involved in the pathway divergence. In the bacterial pathway, N5-CAIR synthetase (PurK) first converts AIR to N5-CAIR, which is then transformed into CAIR catalyzed by the enzyme N5-CAIR mutase (Class I PurE). In the human pathway, AIR carboxylase (Class II PurE) catalyzes the direct conversion of AIR to CAIR. Class I and Class II PurEs …

Functional Studies Of 5-Carboxyaminoimidazole Ribonucleotide Synthetase And Mutase From Thermotoga Maritima, Mingyang Zhao

Wayne State University Theses

De novo purine biosynthesis is divergent depending upon the organism. In bacteria, yeasts and plants, 5-aminoimidazole ribonucleotide (AIR) is converted to 4-carboxyaminoimidazole ribonucleotide (CAIR) by N5-carboxyaminoimidazole ribonucleotide (N5-CAIR) synthetase (PurK) and N5-CAIR mutase (Class I PurE). In animals, AIR is converted into CAIR by AIR carboxylase (Class II PurE). The distinction makes PurK and Class I PurE good targets in design of antimicrobial drugs. N5-CAIR is chemically unstable with t1/2 of about 0.9 minutes at pH 7.8 and 37 °C. If the production of N5-CAIR is not regulated relative to its conversion to CAIR, ATP utilization can rapidly become non-stoichiometric. …

Proteomic Discovery Of Protein Phosphatase 1 Catalytic Subunit Protein Interaction Partners In Human Skeletal Muscle, Zhao Yang

Wayne State University Theses

Protein Phosphatase 1 (PP1), a member of Serine/ Threonine Phosphatase family, targets its dephosphorylation activity on serine and threonine residues. As the catalytic subunit of PP1, PP1c can achieve its substrate specificity only by binding with PP1 regulatory subunits. Previous researches have shown that PP1c can involve in multiple functional regulation by associating with various interaction partners. Since serine/ threonine phosphorylation on the Insulin receptor substrate-1 (IRS1) may direct inactivation and degradation of IRS1, this phosphorylation activity is believed to be a source of Insulin Resistance. PP1 is hypothesized to dephosphorylate serine/ threonine site on IRS1, which may rescue the …

Comparative Study Of The Prevalence Of Psk41 In Heterogenous Vancomycin-Intermediate Staphylococcus Aureus Isolates Against Non- Heterogenous Vancomycin-Intermediate Staphylococcus Aureus Isolates And The Prevalence By Patient Severity, Poorva Mukund Divekar

Wayne State University Theses

COMPARATIVE STUDY OF THE PREVALENCE OF PSK41 IN HETEROGENOUS VANCOMYCIN-INTERMEDIATE STAPHYLOCOCCUS AUREUS ISOLATES AGAINST NON- HETEROGENOUS VANCOMYCIN-INTERMEDIATE STAPHYLOCOCCUS AUREUS ISOLATES AND THE PREVALENCE BY PATIENT SEVERITY

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POORVA DIVEKAR

December 2014

Advisor: Dr. Emily T. Martin

Major: Pharmaceutical Sciences

Degree: Master of Science

Earlier studies have reported that pSK41 plays an important role in the transfer of vancomycin resistance from Vancomycin-resistant Enterococci (VRE) to S. aureus. This transfer leads to the development of Vancomycin-resistant S. aureus (VRSA). Thirteen VRSA cases have been reported in the United States since 2002. To determine and compare the prevalence of pSK41 in hVISA isolates …

Synthesis And Characterization Of Brain Penetrant Prodrug Of Neuroprotective D264: Potential Disease Modifying Treatment Agent For Parkinson's Disease, Fahd Shamoon Dholkawala

Wayne State University Theses

Parkinson's disease (PD) is a complex neurodegenerative disorder with progressive loss of dopamanergic neurons in the substantia nigra region of the brain and accumulation of intracytoplasmic inclusions called `Lewy bodies'. PD is characterized by tremors, rigidity, slowness of movement, bradykinesia and postural imbalances. Although the etiology of PD is not well understood, it is well established that oxidative stress, mitochondrial dysfunction, alpha-synuclein aggregation play a central role in the pathogenesis of PD. Current treatment methods are based on symptomatic relief without addressing the underlying pathophysiological factors responsible for the disease. It is important to develop therapies which can address these …

Oligospermines For Non-Viral Sirna Delivery, Maha Elsayed

Wayne State University Theses

In this thesis, delivery systems for siRNA delivery are introduced with special attention to non-viral vectors. Many successful vectors used in vivo were reviewed. Our work focused on the effect of different architectures of oligospermine polmers on their suitability for siRNA delivery in lung cancer cells. Different archituctures showed different polyplex structures and variable transfection efficiencies. Moreover, we presented a review on nanoimprint lithography techniques with an outlook on possible biological applications in the field of gene and drug delivery.

The Effect Of Alpha-Cyclodextrin On Acute Blood Lipid And Glycemic Responses To A Fat Containg Meal, Evan Neil Fletcher

Wayne State University Theses

Obesity and hyperlipidemia have become major concerns in the United States over the past 30 years. Alpha-Cyclodextrin (á-CD), a naturally occurring soluble dietary fiber, has been shown to reduce dietary fat absorption and improve blood lipid levels in an animal model (mouse and rat) and in human studies. In the current double blind study, 34 healthy male and female participants were recruited to test if á-CD had any acute effect on blood lipid and glycemic responses to a fat containing meal. The participants received the á-CD on one occasion and a placebo the other to determine if there was any …

Novel Inhibitors Of The Bacterial De Novo Purine Biosynthesis Enzymes, N5-Carboxyaminoimidazole Ribonucleotide Synthetase And Mutase, Maria V. Fawaz

Wayne State University Theses

Antibiotic resistance has seen a significant increase during the past decade. The increasing frequency of the drug-resistant bacterial infections has amplified the need for novel antimicrobial agents. De novo purine biosynthesis is one area that has great potential for antibacterial drug development because this pathway is different in microorganisms versus humans. The difference in the pathway is centered on the synthesis and utilization of the purine intermediate N⁵-carboxy-5-aminoimidazole ribonucleotide (N⁵-CAIR). Previous studies have shown that N⁵-CAIR is a key intermediate in purine biosynthesis in bacteria, yeast and fungi, but not in humans. N^{5 …}