Cell and Developmental Biology Commons^™

Machine Learning As A Tool For Early Detection: A Focus On Late-Stage Colorectal Cancer Across Socioeconomic Spectrums, Hadiza Galadima, Rexford Anson-Dwamena, Ashley Johnson, Ghalib Bello, Georges Adunlin, James Blando

Community & Environmental Health Faculty Publications

Purpose: To assess the efficacy of various machine learning (ML) algorithms in predicting late-stage colorectal cancer (CRC) diagnoses against the backdrop of socio-economic and regional healthcare disparities. Methods: An innovative theoretical framework was developed to integrate individual- and census tract-level social determinants of health (SDOH) with sociodemographic factors. A comparative analysis of the ML models was conducted using key performance metrics such as AUC-ROC to evaluate their predictive accuracy. Spatio-temporal analysis was used to identify disparities in late-stage CRC diagnosis probabilities. Results: Gradient boosting emerged as the superior model, with the top predictors for late-stage CRC diagnosis being anatomic site, …

Synergistic Effects Of Nanosecond Pulsed Plasma And Electric Field On Inactivation Of Pancreatic Cancer Cells In Vitro, Edwin A. Oshin, Zobia Minhas, Ruben M. L. Colunga Biancatelli, John D. Catravas, Richard Heller, Siqi Guo, Chunqi Jiang

Bioelectrics Publications

Nanosecond pulsed atmospheric pressure plasma jets (ns-APPJs) produce reactive plasma species, including charged particles and reactive oxygen and nitrogen species (RONS), which can induce oxidative stress in biological cells. Nanosecond pulsed electric field (nsPEF) has also been found to cause permeabilization of cell membranes and induce apoptosis or cell death. Combining the treatment of ns-APPJ and nsPEF may enhance the effectiveness of cancer cell inactivation with only moderate doses of both treatments. Employing ns-APPJ powered by 9 kV, 200 ns pulses at 2 kHz and 60-nsPEF of 50 kV/cm at 1 Hz, the synergistic effects on pancreatic cancer cells (Pan02) …

Gene Expression Under Combined Hypoxia And Acidosis In Chondrosarcoma, Michael Stacey, Kostika Vangjeli, Christopher Osgood

Bioelectrics Publications

Chondrosarcomas are the second most common cause of bone cancer and are removed surgically with wide margins. On recurrence, they are resistant to chemo and radiation therapy and new treatment options are critically required. This tumor type produces hyaline cartilage, a cartilage normally formed under hypoxic and acidic environment due to lack of vasculature in cartilage. Paradoxically, chondrosarcomas arise in the well vascularized, oxygen rich environment of the bone. Hypoxia and acidosis are two stressors where the cellular effects are typically reported separately even though cells experience combined effects of hypoxia and acidosis. Given the mechanistic links between hypoxia and …

Identification Of Proteins Involved In Cell Membrane Permeabilization By Nanosecond Electric Pulses (Nsep), Giedre Silkuniene, Uma Mangalanathan, Alessandra Rossi, Peter A. Mollica, Andrei G. Pakhomov, Olga N. Pakhomova

Bioelectrics Publications

The study was aimed at identifying endogenous proteins which assist or impede the permeabilized state in the cell membrane disrupted by nsEP (20 or 40 pulses, 300 ns width, 7 kV/cm). We employed a LentiArray CRISPR library to generate knockouts (KOs) of 316 genes encoding for membrane proteins in U937 human monocytes stably expressing Cas9 nuclease. The extent of membrane permeabilization by nsEP was measured by the uptake of Yo-Pro-1 (YP) dye and compared to sham-exposed KOs and control cells transduced with a non-targeting (scrambled) gRNA. Only two KOs, for SCNN1A and CLCA1 genes, showed a statistically significant reduction in …

Combined 3d Bioprinting And Tissue-Specific Ecm System Reveals The Influence Of Brain Matrix On Stem Cell Differentiation, Martina Zamponi, Peter A. Mollica, Yara Khodour, Julie S. Bjerring, Robert D. Bruno, Patrick C. Sachs

Medical Diagnostics & Translational Sciences Faculty Publications

We have previously shown that human and murine breast extracellular matrix (ECM) can significantly impact cellular behavior, including stem cell fate determination. It has been established that tissue-specific extracellular matrix from the central nervous system has the capacity to support neuronal survival. However, the characterization of its influence on stem cell differentiation and its adaptation to robust 3D culture models is underdeveloped. To address these issues, we combined our 3D bioprinter with hydrogels containing porcine brain extracellular matrix (BMX) to test the influence of the extracellular matrix on stem cell differentiation. Our 3D bioprinting system generated reproducible 3D neural structures …

A Single-Cell Atlas Of Bovine Skeletal Muscle Reveals Mechanisms Regulating Intramuscular Adipogenesis And Fibrogenesis, Leshan Wang, Peidong Gao, Chaoyag Li, Qianglin Liu, Zeyang Yao, Yuxia Li, Xujia Zhang, Jiangwen Sun, Constantine Simintiras, Matthew Welborn, Kenneth Mcmillin, Stephanie Oprescu, Shihuan Kuang, Xing Fu

Computer Science Faculty Publications

Background: Intramuscular fat (IMF) and intramuscular connective tissue (IMC) are often seen in human myopathies and are central to beef quality. The mechanisms regulating their accumulation remain poorly understood. Here, we explored the possibility of using beef cattle as a novel model for mechanistic studies of intramuscular adipogenesis and fibrogenesis.

Methods: Skeletal muscle single-cell RNAseq was performed on three cattle breeds, including Wagyu (high IMF), Brahman (abundant IMC but scarce IMF), and Wagyu/Brahman cross. Sophisticated bioinformatics analyses, including clustering analysis, gene set enrichment analyses, gene regulatory network construction, RNA velocity, pseudotime analysis, and cell-cell communication analysis, were performed to elucidate …

Enhancing The Conformational Stability Of The Cl-Par-4 Tumor Suppressor Via Site-Directed Mutagenesis, Samjhana Pandey, Krishna K. Raut, Andrea M. Clark, Antoine Baudin, Lamya Djemri, David S. Libich, Komala Ponniah, Steven M. Pascal

Chemistry & Biochemistry Faculty Publications

Intrinsically disordered proteins play important roles in cell signaling, and dysregulation of these proteins is associated with several diseases. Prostate apoptosis response-4 (Par-4), an approximately 40 kilodalton proapoptotic tumor suppressor, is a predominantly intrinsically disordered protein whose downregulation has been observed in various cancers. The caspase-cleaved fragment of Par-4 (cl-Par-4) is active and plays a role in tumor suppression by inhibiting cell survival pathways. Here, we employed site-directed mutagenesis to create a cl-Par-4 point mutant (D313K). The expressed and purified D313K protein was characterized using biophysical techniques, and the results were compared to that of the wild-type (WT). We have …

Electroporation And Cell Killing By Milli- To Nanosecond Pulses And Avoiding Neuromuscular Stimulation In Cancer Ablation, Emily Gudvangen, Vitalii Kim, Vitalij Novickij, Federico Battista, Andrei G. Pakhomov

Bioelectrics Publications

Ablation therapies aim at eradication of tumors with minimal impact on surrounding healthy tissues. Conventional pulsed electric field (PEF) treatments cause pain and muscle contractions far beyond the ablation area. The ongoing quest is to identify PEF parameters efficient at ablation but not at stimulation. We measured electroporation and cell killing thresholds for 150 ns–1 ms PEF, uni- and bipolar, delivered in 10- to 300-pulse trains at up to 1 MHz rates. Monolayers of murine colon carcinoma cells exposed to PEF were stained with YO-PRO-1 dye to detect electroporation. In 2–4 h, dead cells were labeled with propidium. Electroporation and …

Assessment Of Combined Modality Therapy For Non-Small-Cell Lung Carcinoma: A Simulation Study Concerning Concurrent Chemo-Brachytherapy, Hadi Rezaei, Hesameddin Mostaghimi, Ali Reza Mehdizadeh

Electrical & Computer Engineering Faculty Publications

Although surgery is the treatment of choice for early-stage non-small-cell lung carcinoma, almost two-thirds of patients do not have acceptable pulmonary function for extensive surgeries. The alternative approach for this large group of patients is sublobar resection along with low-dose-rate (LDR) brachytherapy (BT). However, patients with resected lungs have a high risk of recurrence and are often treated with platinum-based (Pt-based) chemotherapy (CT). In this study, we aimed to evaluate the absorbed doses of lung and other thoracic organs, considering concurrent chemo-BT with LDR sources in two modalities: conventional vs. unconventional Pt-based CT. We used the MCNPX code for simulations …

Alkaline Plasma-Activated Water (Paw) As An Innovative Therapeutic Avenue For Cancer Treatment, Bolun Pang, Zhijie Liu, Sitao Wang, Yuting Gao, Miao Qi, Dehui Xu, Renwu Zhou, Dingxin Liu, Michael G. Kong

Bioelectrics Publications

Plasma-activated water (PAW) is considered to be an effective anticancer agent due to the diverse aqueous reactive oxygen and nitrogen species (RONS: ROS and RNS), but the drawback of low dose and short duration of RONS in acidified PAW limits their clinical application. Herein, this Letter presents an innovative therapeutic avenue for cancer treatment with highly-effective alkaline PAW prepared by air surface plasma. This anticancer alkaline formulation is comprised of a rich mixture of highly chemical RONS and exhibited a prolonged half-life compared to acidified PAW. The H₂O₂, NO₂-, and ONOO^-/O_{2 …}

Connexin Hemichannel Activation By S-Nitrosoglutathione Synergizes Strongly With Photodynamic Therapy Potentiating Anti-Tumor Bystander Killing, Chiara Nardin, Chiara Peres, Sabrina Putti, Tiziana Orsini, Claudia Colussi, Flavia Mazzarda, Marcello Raspa, Ferdinando Scavizzi, Anna Maria Salvatore, Francesco Chiani, Abraham Tettey-Matey, Yuanyuan Kuang, Guang Yang, Mauricio A. Retamal, Fabio Mammano

Bioelectrics Publications

In this study, we used B16-F10 cells grown in the dorsal skinfold chamber (DSC) preparation that allowed us to gain optical access to the processes triggered by photodynamic therapy (PDT). Partial irradiation of a photosensitized melanoma triggered cell death in non-irradiated tumor cells. Multiphoton intravital microscopy with genetically encoded fluorescence indicators revealed that bystander cell death was mediated by paracrine signaling due to adenosine triphosphate (ATP) release from connexin (Cx) hemichannels (HCs). Intercellular calcium (Ca²⁺) waves propagated from irradiated to bystander cells promoting intracellular Ca²⁺ transfer from the endoplasmic reticulum (ER) to mitochondria and rapid activation of …

Effect Of He Plasma Jet Versus Surface Plasma On The Metabolites Of Acute Myeloid Leukemia Cells, Dehui Xu, Ning Ning, Yujing Xu, Wenjie Xia, Hai-Lan Chen, Michael G. Kong

Bioelectrics Publications

Cold atmospheric plasma, including plasma jet and surface plasma, can promote the apoptosis of cancer cells without causing significant damage to surrounding normal cells, which was hopeful to be applied to the clinical cancer therapy. However, experimental plasma devices used directly to clinical experiments has challenges in technology and methods, especially the difference in killing tumor cells efficiency of these two common plasma sources. Therefore, it is great necessity to explore the differences in treating tumors between different plasma sources. This paper achieved good killing efficiency by using two kinds of cold atmospheric plasma generating devices, namely plasma jet and …

Tick Extracellular Vesicles Enable Arthropod Feeding And Promote Distinct Outcomes Of Bacterial Infection, Adela S. Oliva Chávez, Xiaowei Wang, Liron Marnin, Nathan K. Archer, Holly L. Hammond, Erin E. Mcclure Carroll, Dana K. Shaw, Brenden G. Tully, Amanda D. Buskirk, Shelby L. Ford, L. Rainer Butler, Preeti Shahi, Kateryna Morozova, Cristina C. Clement, Lauren Lawres, Anya J. O'Neal, Choukri Ben Mamoun, Kathleen L. Mason, Brandi E. Hobbs, Glen A. Scoles, Eileen M. Barry, Daniel E. Sonenshine, Utpal Pal, Jesus G. Valenzuela, Marcelo B. Sztein, Marcela F. Pasetti, Michael L. Levin, Michail Kotsyfakis, Steven M. Jay, Jason F. Huntley, Lloyd S. Miller, Laura Santambrogio, Joao H.F. Pedra

Biological Sciences Faculty Publications

Extracellular vesicles are thought to facilitate pathogen transmission from arthropods to humans and other animals. Here, we reveal that pathogen spreading from arthropods to the mammalian host is multifaceted. Extracellular vesicles from Ixodes scapularis enable tick feeding and promote infection of the mildly virulent rickettsial agent Anaplasma phagocytophilum through the SNARE proteins Vamp33 and Synaptobrevin 2 and dendritic epidermal T cells. However, extracellular vesicles from the tick Dermacentor andersoni mitigate microbial spreading caused by the lethal pathogen Francisella tularensis. Collectively, we establish that tick extracellular vesicles foster distinct outcomes of bacterial infection and assist in vector feeding by acting …

Self And Microbiota-Derived Epitopes Induce Cd4⁺ T Cell Anergy And Conversion Into Cd4⁺Foxp3⁺ Regulatory Cells, Michal P. Kuczma, Edyta A. Szurek, Anna Cebula, Vu L. Ngo, Maciej Pietrzak, Piotr Kraj, Timothy L. Denning, Leszek Ignatowicz

Biological Sciences Faculty Publications

The physiological role of T cell anergy induction as a key mechanism supporting self-tolerance remains undefined, and natural antigens that induce anergy are largely unknown. In this report, we used TCR sequencing to show that the recruitment of CD4⁺CD44⁺Foxp3⁻CD73⁺FR4⁺ anergic (Tan) cells expands the CD4⁺Foxp3⁺ (Tregs) repertoire. Next, we report that blockade in peripherally-induced Tregs (pTregs) formation due to mutation in CNS1 region of Foxp3 or chronic exposure to a selecting self-peptide result in an accumulation of Tan cells. Finally, we show that microbial antigens from Akkermansia muciniphila …

Stobe Photography Mapping Of Cell Membrane Potential With Nanosecond Resolution, Allen S. Kiester, Bennett L. Ibey, Zachary N. Coker, Andrei G. Pakhomov, Joel N. Bixler

Bioelectrics Publications

The ability to directly observe membrane potential charging dynamics across a full microscopic field of view is vital for understanding interactions between a biological system and a given electrical stimulus. Accurate empirical knowledge of cell membrane electrodynamics will enable validation of fundamental hypotheses posited by the single shell model, which includes the degree of voltage change across a membrane and cellular sensitivity to external electric field non-uniformity and directionality. To this end, we have developed a high-speed strobe microscopy system with a time resolution of ~ 6 ns that allows us to acquire time-sequential data for temporally repeatable events (non-injurious …

Nanopulse Stimulation (Nps) Induces Tumor Ablation And Immunity In Orthotopic 4t1 Mouse Breast Cancer: A Review, Stephen J. Beebe, Brittany P. Lassiter, Siqi Guo

Bioelectrics Publications

Nanopulse Stimulation (NPS) eliminates mouse and rat tumor types in several different animal models. NPS induces protective, vaccine-like effects after ablation of orthotopic rat N1-S1 hepatocellular carcinoma. Here we review some general concepts of NPS in the context of studies with mouse metastatic 4T1 mammary cancer showing that the postablation, vaccine-like effect is initiated by dynamic, multilayered immune mechanisms. NPS eliminates primary 4T1 tumors by inducing immunogenic, caspase-independent programmed cell death (PCD). With lower electric fields, like those peripheral to the primary treatment zone, NPS can activate dendritic cells (DCs). The activation of DCs by dead/dying cells leads to increases …

Enhanced Electric Pulse Technology For The Ablation Of Pancreatic Cancer, Siqi Guo, Niculina I. Burcus, Chelsea M. Edelblute, James Hornef, Chunqi Jiang, Karl Schoenbach, Richard Heller, Stephen J. Beebe

Bioelectrics Publications

Electric pulse based technology has been developed and studied as a non-thermal ablation method for local control of pancreatic cancer. Irreversible electroporation (IRE) has shown a significant survival benefit for local advanced pancreatic cancer in clinical trials. However, incomplete ablation with local recurrence and major complications limit the potential of this new technology. We have developed an integrated moderate heating electric pulse delivery system which consists of controllable tumor heating, multi-parameter monitoring and electric pulse delivery. The impedance of tumor is greatly decreased after moderate heating at 42°C for 1–2 min, which does not cause any cell death. Moderate heating …

Non-Canonicaly Recruited Tcrαβcd8Αα Iels Recognize Microbial Antigens, Lukasz Wojciech, Edyta Szurek, Michal Kuczma, Anna Cebula, Wessam R. Elhefnawy, Maciej Pietrzak, Grzegorz Rempala, Leszek Ignatowicz

Computer Science Faculty Publications

In the gut, various subsets of intraepithelial T cells (IELs) respond to self or non-self-antigens derived from the body, diet, commensal and pathogenic microbiota. Dominant subset of IELs in the small intestine are TCRαβCD8αα⁺ cells, which are derived from immature thymocytes that express self-reactive TCRs. Although most of TCRαβCD8αα⁺ IELs are thymus-derived, their repertoire adapts to microbial flora. Here, using high throughput TCR sequencing we examined how clonal diversity of TCRαβCD8αα⁺ IELs changes upon exposure to commensal-derived antigens. We found that fraction of CD8αα⁺ IELs and CD4⁺ T cells express identical …

Pkc-Dependent Phosphorylation Of Enos At T495 Regulates Enos Coupling And Endothelial Barrier Function In Response To G(+) -Toxins, Feng Chen, Sanjiv Kumar, Yanfang Yu, Saurabh Aggarwal, Christine Gross, Yusi Wang, Trinad Chakraborty, Alexander D. Verin, John D. Catravas, Rudolf Lucas, Stephen M. Black, David J. R. Fulton

Bioelectrics Publications

Gram positive (G(+)) infections make up similar to 50% of all acute lung injury cases which are characterized by extensive permeability edema secondary to disruption of endothelial cell (EC) barrier integrity. A primary cause of increased permeability are cholesterol-dependent cytolysins (CDCs) of G(+)-bacteria, such as pneumolysin (PLY) and listeriolysin-O (LLO) which create plasma membrane pores, promoting Ca2+-influx and activation of PKC alpha. In human lung microvascular endothelial cells (HLMVEC), pretreatment with the nitric oxide synthase (NOS) inhibitor, ETU reduced the ability of LLO to increase microvascular cell permeability suggesting an endothelial nitric oxide synthase (eNOS)-dependent mechanism. LLO stimulated superoxide production …

Mouse Oocyte Maturation And Embryo Development After Exposure To Vemurafenib (Plx4032), An Anti-Melanoma B-Raf V600e Inhibitor, Bo Liu

Theses and Dissertations in Biomedical Sciences

Vemurafenib is a selective B-Raf^V600E inhibitor in melanoma targeted therapy which also inhibits the wild type B- and C-Raf. In oocyte maturation, the C-Raf/MAPK pathway acts as an important self-enhancing and promoting system, w hereas in embryo development, the C-Raf/M APK pathway participates in pre- and post- implantation embryo proliferation and differentiation.

The hypothesis: Vemurafenib has detrimental effects on oocyte maturation and/or embryo development. Mouse oocytes and one cell (1C) mouse embryos were tested by ex vivo culturing with Vemurafenib in serial dilution. Oocytes were evaluated by cell cycle morphology, spindle formation and chromosomal alignment by im munofluorescence (IF) …

Follicle-Stimulating Hormone Promotes Rank Expression On Human Monocytes, Joseph G. Cannon, Barbara Kraj, Gloria Sloan

Medical Diagnostics & Translational Sciences Faculty Publications

Elevated serum concentrations of follicle-stimulating hormone (FSH) are associated with diminished bone density in women, beginning years before menopause and the decline in estradiol. We hypothesized that FSH promotes development of myeloid cells toward the bone-resorbing osteoclast phenotype. This was tested by isolating peripheral blood mononuclear cells from nine healthy adults, incubating them in the presence of FSH at three different concentrations spanning the physiological range, and then measuring the expression of receptor activator for NF-κB (RANK, a surface marker for osteoclasts) on CD14+ cells by flow cytometry. In the absence of FSH, 3.3±0.5% of the cells expressed high levels …

The Study Of Nitric Oxide Synthase Expression, Function, And Regulation In The Renal Vasculature During Postnatal Renal Development, Brian Blake Ratliff

Theses and Dissertations in Biomedical Sciences

The newborn kidney is vulnerable to vasomotor acute renal failure (ARF) from adverse perinatal events or complications of prematurity. Nitric oxide (NO) vasodilation is vitally protective in this type of ARF, but its relationship with other vasoactive factors, such as angiotensin II (AII) has not been examined. In the immature kidney, nitric oxide synthase (NOS) isoforms, specifically eNOS and nNOS, are developmentally regulated, but their specific role and regulation are unknown.

The enhanced vasodilatory role of NO in the immature kidney was hypothesized to be attributed to regulatory, expressional, and functional differences in eNOS and nNOS isoforms from the adult. …

The Ultrastructure Of The Olfactory System In Two Species Of Short-Tailed Shrews, Blarina Brevicauda And Blarina Carolinensis, Lisa Johnson Byrum

Theses and Dissertations in Biomedical Sciences

Several studies of the fine structure of the olfactory system of rodents have been conducted, but very little research has been done on members of the Insectivora. The olfactory systems of the northern short-tailed shrew, Blarina brevicauda, and the southern short-tailed shrew, Blarina carolinensis, were examined by light and electron microscopy. These shrews were live trapped in the vicinity of Norfolk, Virginia throughout all months of the year. Olfactory tissues were processed following standard transmission and scanning electron microscopy protocols. The olfactory system structures investigated included the olfactory epitheliumlmucosa (OEM), main olfactory bulb (MOB), accessory olfactory bulb (AOB), …

An Ultrastructural Survey Of The Nuchal Glands Of Rhabdophis Tigrinus (Serpentes: Colubridae), Kathleen A. Roberts

Biological Sciences Theses & Dissertations

Rhabdophis tigrinus, an Asian natricine snake, possesses a series of integumentary glands located in the nuchal skin. Previous studies indicated that the nuchal glands are of mesodermal origin, contain cardiac steroids analogous to bufotoxins found in the parotoid glands of toads, which are included in the snake's diet. The nuchal glands are defensive in function. Preliminary histological studies revealed differences in quality of the gland tissue compared to previous studies, and difference in fixation techniques were suspected. Seven specimens of R. tigrinus were fixed by perfusion using a conservative fixation process standard for electron microscopy. The nuchal gland series …

Insulinlike Growth Factor 1- And 2-Augmented Collagen Gel Repair Of Facial Osseous Defects, James S. Toung, Roy C. Ogle, Raymond F. Morgan, William H. Lindsey

Medical Diagnostics & Translational Sciences Faculty Publications

BACKGROUND: Defects of the facial bone structure are common problems for the facial plastic surgeon. Native type 1 collagen gels (T1CGs) have been shown to mediate repair of facial critical-size defects in rat models.

OBJECTIVE: To evaluate the efficacy of T1CG augmented with insulinlike growth factor (IGF) 1, IGF-2, and a combination of IGF-1 and IGF-2 on the repair of facial critical-size defects in a rodent model.

METHODS: Twenty-four retired male breeder Sprague-Dawley rats were divided into 4 groups of 6 animals. Facial critical-size defects were created by removing the nasalis bones with a bone-cutting drill. Defects were treated with …

Efficacy Of AllowashTm Solution In Solubilization Of Bone Marrow, Alyce Marie Linthurst

Biological Sciences Theses & Dissertations

LifeNet currently cleans allograft bone utilizing Allowash^TM Technology, which encompasses the use of a closed continuous circulation chamber to remove bone marrow by flushing it with Allowash^TM Solution for a prescribed time and temperature after which, it is rinsed with various solutions to remove residual detergent that could be toxic to the recipient. A portion of this process employs Allowash^TM Solution to improve the solubilization and removal of protein and cellular elements in the red bone marrow. This study examines the effectiveness of Allowash^TM Solution in comparison to its component detergents Nonidet P40, Nonoxynol 9 and …

Pressure-Induced Intracellular Signaling In Isolated Arteries, Victor A. Miriel

Theses and Dissertations in Biomedical Sciences

The ability of cells to respond to mechanical stimuli has been studied through a variety of techniques in numerous cell types. The cells of the vascular wall have adapted to specific mechanical stresses through the activation of intracellular signaling pathways which result in cell-specific responses such as hypertrophy, hyperplasia, proliferation, and migration. Vascular smooth muscle of the arteries have been shown to be sensitive to mechanical stimuli such as stretch, and pressure.

This study attempts to add to the current knowledge of mechanotransduction by utilizing the isolated artery preparation. This preparation allows for the study of vascular smooth muscle signal …

The Role Of Glycoconjugates In Mediating Human Fertilization And Induction Of Fetomaternal Tolerance, Manish S. Patankar

Theses and Dissertations in Biomedical Sciences

Using the hemizona assay (HZA), a in vitro sperm-egg binding assay, we show that specific glycoconjugates known to inhibit immune cell interactions mediated by the selectins, potently block human sperm-egg binding. The selectin ligand sialyl Lewis^x inhibits sperm binding in the HZA by 60% at a concentration of 1 mg/ml. Our data indicates that glycodelin-A, a endometrial glycoprotein known to block sperm-egg binding in the HZA at low concentrations expresses unusual fucosylated lacdiNAc type glycans. The fucosylated lacdiNAc type sugars have been previously shown to be 15-20 fold more potent ligands of E-selectin. Glycodelin-S a seminal plasma glycoform of …

A Kinetic Investigation Of The Mechanism Of Muscle Contraction With A Series Of Nucleotides, Wei Jiang

Theses and Dissertations in Biomedical Sciences

Muscle contraction is thought to be accomplished by sliding of myosin filaments along actin filaments. Although actomyosin naturally uses ATP as an energy source, it can also use other nucleoside triphosphates (NTP) as substrates. In this work, the dependence of rate and equilibrium constants of the various steps in the muscle contraction mechanism upon nucleotide structure was investigated to unravel the dependence of the mechanical properties of the muscle upon changes in different biochemical steps of the mechanism.

The experiments measuring the dissociation of actomyosin by NTP (or mant-NTP) shows that both the rate constant of actomyosin-S1 dissociation and second …

Cellular Mechanisms Underlying Myogenic Reactivity In Isolated Arterioles, Hui Zou

Theses and Dissertations in Biomedical Sciences

The myogenic reactivity provides one of the principal mechanisms for blood flow autoregulation. The aims of the performed studies described in this dissertation were to test the role of [Ca²⁺]_i and MLC phosphorylation in arteriolar myogenic reactivity and further examine the source(s) of activator Ca²⁺ required to initiate and maintain myogenic vasoconstriction. In addition, the possible underlying mechanism of contractile protein expression was also addressed.

These studies used male Sprague Dawley rats of 200 ~ 350 grams body weight. Experiments were carried out using rat cremaster first order arterioles and mesenteric vessels. Gel electrophoresis and immunoblotting …