Life Sciences Commons^™

Dna Repair Deficiency In Huntington's Disease Fibroblasts And Induced Pluripotent Stem Cells, Peter Anthony Mollica

Biological Sciences Theses & Dissertations

Mutant huntingtin protein (mhtt)– the protein responsible for cellular dysfunction in Huntington’s disease (HD) –is a product of an expanded trinucleotide repeat (TNR) cytosine-adenine-guanine (CAG) sequence in exon 1 of the huntingtin (HTT) gene. The pathology of HD has been extensively researched; however, the mechanism by which the disease-causing TNR expansions occur in somatic cells remains elusive. Interestingly, HD has often been referred to a ‘DNA repair disease’, even though DNA repair dysfunction in situ has not been identified. We hypothesized that presence of the mhtt protein affects the expression of DNA repair genes used to address DNA repair, ultimately …

The Effects Of Propofol, Sodium Pentobarbital, And Ketamine Hydrochloride On In Vitro Mouse Embryonic Development, Tyler C. Balak

Theses and Dissertations in Biomedical Sciences

Every year more than 75,000 pregnant women are exposed to teratogenic medications or general anesthesia during non-obstetric surgery in the US,1-4 and embryonic effects of general anesthesia are of particular interest in laboratory research and veterinary medicine. The mouse system is used to screen potential toxic effects of anesthetics used in egg retrieval for in vitro fertilization (IVF), or those of pharmacologic agents which may come in contact with the egg or early embryo. Mouse preimplantation 2-cell embryos were exposed in vitro to incremental concentrations of common general anesthetics within and exceeding the normal clinical dosage range for mice (propofol …

Plasma Activated Air Mediates Gene Transfer, Chelsea M. Edelblute

Biological Sciences Theses & Dissertations

Cold plasma is produced when strong applied electric fields accelerate free electrons, which dissociate, excite, or ionize gaseous molecules [1]. The deposition of ions from the plasma source is dependent on power generation, input gas composition, and gas flow rate. In the presence of reactive species, the membrane of eukaryotic cells is compromised allowing for otherwise impermeant molecules, such as DNA, to enter the inner-cell milieu [2].

The efficacy of a novel cold plasma reactor based on shielded sliding discharge for the delivery of plasmid DNA was assessed. The device is entirely non-contact, wherein the plasma never directly touches the …

Picosecond To Terahertz Perturbation Of Interfacial Water And Electropermeabilization Of Biological Membranes, P. Thomas Vernier, Zachary A. Levine, Ming-Chak Ho, Shu Xiao, Iurii Semenov, Andrei G. Pakhomov

Bioelectrics Publications

Non-thermal probing and stimulation with subnanosecond electric pulses and terahertz electromagnetic radiation may lead to new, minimally invasive diagnostic and therapeutic procedures and to methods for remote monitoring and analysis of biological systems, including plants, animals, and humans. To effectively engineer these still-emerging tools, we need an understanding of the biophysical mechanisms underlying the responses that have been reported to these novel stimuli. We show here that subnanosecond (≤500 ps) electric pulses induce action potentials in neurons and cause calcium transients in neuroblastoma-glioma hybrid cells, and we report complementary molecular dynamics simulations of phospholipid bilayers in electric fields in which …

Dose-Dependent Atp Depletion And Cancer Cell Death Following Calcium Electroporation, Relative Effect Of Calcium Concentration And Electric Field Strength, Emilie Louise Hansen, Esin Bengisu Sozer, Stefania Romeo, Stine Krog Frandsen, P. Thomas Vernier, Julie Gehl

Bioelectrics Publications

Background: Electroporation, a method for increasing the permeability of membranes to ions and small molecules, is used in the clinic with chemotherapeutic drugs for cancer treatment (electrochemotherapy). Electroporation with calcium causes ATP (adenosine triphosphate) depletion and cancer cell death and could be a novel cancer treatment. This study aims at understanding the relationship between applied electric field, calcium concentration, ATP depletion and efficacy. Methods: In three human cell lines — H69 (small-cell lung cancer), SW780 (bladder cancer), and U937 (leukaemia), viability was determined after treatment with 1, 3, or 5 mM calcium and eight 99 μs pulses with 0.8, 1.0, …

Effects Of Nanosecond Pulse Electric Fields On Cellular Elasticity, Diganta Dutta, Anthony Asmar, Michael W. Stacey

Bioelectrics Publications

We investigated the effects of a single 60 nanosecond pulsed electric field (nsPEF) of low (15 kV/cm) and high (60 kV/cm) field strengths on cellular morphology and membrane elasticity in Jurkat cells using fluorescent microscopy and atomic force microscopy (AFM). We performed force displacement measurements on cells using AFM and calculated the Young's modulus for membrane elasticity. Differential effects were observed depending upon pulsing conditions. We found that a single nsPEF of low field strength did not induce any apparent cytoskeletal breakdown and had minor morphological changes. Interestingly, force measurements and calculation of Young's modulus showed a significant decrease in …

Mechanisms Of Nanosecond Pulsed Electric Field (Nspef)-Induced Cell Death In Cells And Tumors, Stephen J. Beebe

Bioelectrics Publications

The evolution of pulse power technology from high power physics to biology and medicine places nanosecond pulsed electric fields (nsPEFs) in positions for in vitro and in vivo applications as non-ligand agonists that not only bypass plasma membrane receptors for induction of intracellular signaling pathways, but also bypass intracellular oncogenic impasses to induce cell death by regulated mechanisms. Based on work reviewed here, a likely scenario for cell and tumor demise includes nsPEF-induced permeabilization of the plasma membrane, Ca2+ influx, dissipation of the mitochondrial membrane potential, which is likely due to events beyond permeabilization of the inner mitochondrial membrane, cytochrome …

Altered Connexin 43 Expression Underlies Age-Dependent Decrease Of Regulatory T Cell Suppressor Function In Nonobese Diabetic Mice, Michel Kuczma, Cong-Yi Wang, Leszek Ignatowicz, Robert Gourdi, Piotr Kraj

Biological Sciences Faculty Publications

Type 1 diabetes is one of the most extensively studied autoimmune diseases, but the cellular and molecular mechanisms leading to T cell–mediated destruction of insulin-producing β cells are still not well understood. In this study, we show that regulatory T cells (T_regs) in NOD mice undergo age-dependent loss of suppressor functions exacerbated by the decreased ability of activated effector T cells to upregulate Foxp3 and generate T_regs in the peripheral organs. This age-dependent loss is associated with reduced intercellular communication mediated by gap junctions, which is caused by impaired upregulation and decreased expression of connexin 43. Regulatory …

Presence And Localization Of Pro-And Mature Forms Of Biglycan And Decorin In Human Costal Cartilage Derived From Chest Wall Deformities, Anthony Asmar, A. Werner, R. E. Kelly Jr., A. Fecteau, Michael W. Stacey

Bioelectrics Publications

Costal cartilage is a type of hyaline cartilage that forms rod-like structures that connect the ribs to the sternum. The most common chest wall deformities, pectus excavatum and pectus carinatum involved efective costal cartilage resulting in sternal displacement. Costal cartilage is not widely studied leaving little insight into possible factors involved in the pathogenesis of these pectus deformities. This study focused on the presence and distribution of two important regulators of collagen fibrillogenesis and organization, biglycan and decorin. Immunohistochemical analysis of transverse cross sections of normal and deformed costal cartilage revealed that biglycan and decorin mainly localized in the territorial …

Introduction To Fifth Special Issue On Electroporation-Based Technologies And Treatments, Damijan Miklavčič, Lluis M. Mir, P. Thomas Vernier

Bioelectrics Publications

This special issue of the Journal of Membrane Biology contains reports on recent developments in the field of electroporation by participants in the International Workshop and Postgraduate Course on Electroporation-Based Technologies and Treatments held in November 2014 in Ljubljana. This was the eighth session of what is now an annual event, first organized in 2003.

Numerical Geometry Of Map And Model Assessment, Willy Wriggers, Jing He

Mechanical & Aerospace Engineering Faculty Publications

We are describing best practices and assessment strategies for the atomic interpretation of cryo-electron microscopy (cryo-EM) maps. Multiscale numerical geometry strategies in the Situs package and in secondary structure detection software are currently evolving due to the recent increases in cryo-EM resolution. Criteria that aim to predict the accuracy of fitted atomic models at low (worse than 8 angstrom) and medium (4-8 angstrom) resolutions remain challenging. However, a high level of confidence in atomic models can be achieved by combining such criteria. The observed errors are due to map-model discrepancies and due to the effect of imperfect global docking strategies. …