Against All Odds, British Government Policies and Civil Defense during the Blitz

During World War I, technological advances in air power expanded the field of battle beyond the front lines and British civilians previously insulated from the realities of war experienced a new threat from the air. This experience highlighted the impact of modern warfare on citizens and the need for greater home defense measures. Bombing attacks in Europe, Asia, and Africa during the 1930s further demonstrated this type of conflict, making British civil defense more critical. After nine months between September 7, 1940 and May 10, 1941, over 40,000 civilians perished from the bombs dropped by the German air force on Britain’s largest industrial cities. Much of the scholarship written post World War II attaches government failures to these deaths. Using government documents, newspapers, photos, opinion polls, books, and articles, this thesis will examine civilian aerial warfare philosophies established after World War I and the resulting casualty projections prior to the Blitz. It will also describe several programs implemented by the British government as well as its communication tactics to increase public awareness and preparation in the event of an attack. Furthermore, it will evaluate how civil defense strategies adapted in response to the bombings. By comparing the number of actual deaths to pre-Blitz projections and statistics from other bombing attacks, this thesis will demonstrate that the government’s civil defense efforts successfully saved countless lives

Systematic comparison of nonviral gene delivery strategies for efficient co-expression of two transgenes in human mesenchymal stem cells

Background Human mesenchymal stem cells (hMSCs) are being researched for cell-based therapies due to a host of unique properties, however, genetic modification of hMSCs, accomplished through nonviral gene delivery, could greatly advance their therapeutic potential. Furthermore, expression of multiple transgenes in hMSCs could greatly advance their clinical significance for treatment of multifaceted diseases, as individual transgenes could be expressed that target separate pathogenic drivers of complex diseases. Expressing multiple transgenes can be accomplished by delivering multiple DNA vectors encoding for each transgene, or by delivering a single poly-cistronic vector that encodes for each transgene and accomplishes expression through either use of multiple promoters, an internal ribosome entry site (IRES), or a 2A peptide sequence. These different transgene expression strategies have been used to express multiple transgenes in various mammalian cells, however, they have not been fully evaluated in difficult-to-transfect primary cells, like hMSCs. This study systematically compared four transgene expression and delivery strategies for expression of two reporter transgenes in four donors of hMSCs from two tissue sources using lipid- and polymer-mediate transfection, as follows: (i) delivery of separate DNA vectors in separate nanoparticles; (ii) delivery of separate DNA vectors combined in the same nanoparticle; (iii) delivery of a bi-cistronic DNA vector with an IRES sequence via nanoparticles; and (iv) delivery of a bi-cistronic DNA vector with a dual 2A peptide sequence via nanoparticles. Results Our results indicate that expression of two transgenes in hMSCs, independent of expression or delivery strategy, is inefficient compared to expressing a single transgene. However, delivery of separate DNA vectors complexed in the same nanoparticle, or delivery of a bi-cistronic DNA vector with a dual 2A peptide sequence, significantly increased the number of hMSCs expressing both transgenes compared to other conditions tested. Conclusion Separate DNA vectors delivered in the same nanoparticle and bi-cistronic DNA vectors with dual 2A peptide sequences are highly efficient at simultaneously expressing two transgenes in multiple donors of hMSCs from different tissue sources. The data presented in this work can guide the development of hMSC transfection systems for delivery of multiple transgenes, with the goal of producing clinically relevant, genetically modified hMSCs

Glucocorticoid Priming of Nonviral Gene Delivery to hMSCs Increases Transfection by Reducing Induced Stresses

Human mesenchymal stem cells (hMSCs) are under study for cell and gene therapeutics because of their immunomodulatory and regenerative properties. Safe and efficient gene delivery could increase hMSC clinical potential by enabling expression of transgenes for control over factor production, behavior, and differentiation. Viral delivery is efficient but suffers from safety issues, while nonviral methods are safe but highly inefficient, especially in hMSCs. We previously demonstrated that priming cells with glucocorticoids (Gcs) before delivery of DNA complexes significantly increases hMSC transfection, which correlates with a rescue of transfection-induced metabolic and protein synthesis decline, and apoptosis. In this work, we show that transgene expression enhancement is mediated by transcriptional activation of endogenous hMSC genes by the cytosolic glucocorticoid receptor (cGR) and that transfection enhancement can be potentiated with a GR transcription-activation synergist. We demonstrate that the Gc-activated cGR modulates endogenous hMSC gene expression to ameliorate transfection-induced endoplasmic reticulum (ER) and oxidative stresses, apoptosis, and inflammatory responses to prevent hMSC metabolic and protein synthesis decline, resulting in enhanced transgene expression after nonviral gene delivery to hMSCs. These results provide insights important for rational design of more efficient nonviral gene delivery and priming techniques that could be utilized for clinical hMSC applications

Thermodynamic and kinetic consistency of calculated binary nucleation rates

To establish the accuracy and applicability of analytical expressions for the steady state rate of binary nucleation, we numerically solved the birth-death equations for the vapor-to-liquid transition. These calculations were performed using rate coefficients that are consistent with the principle of detailed balance and a new self-consistent form of the equilibrium distribution function for binary cluster concentrations. We found that the customary saddle point and growth path approximations are almost always valid and can fail only if the nucleating solution phase is significantly nonideal. For example, problems can arise when the vapor composition puts the system on the verge of partial liquid phase miscibility. When this occurs for comparable monomer impingement rates, nucleation still occurs through the saddle point, but the usual quadratic expansion for the cluster free energy is inadequate. When the two impingement rates differ significantly, however, the major particle flux may bypass the saddle point and cross a low ridge on the free energy surface. The dependence of the saddle point location on the gas phase composition is also important in initiating or terminating ridge crossing nucleation

On the Origin of Logarithmic-Normal Distributions: An Analytical Derivation, and its Application to Nucleation and Growth Processes

The logarithmic-normal (lognormal) distribution is one of the most frequently observed distributions in nature and describes a large number of physical, biological and even sociological phenomena. The origin of this distribution is therefore of broad interest but a general derivation from basic principles is still lacking. Using random nucleation and growth to describe crystallization processes we derive the time development of grain size distributions. Our derivation provides, for the first time, an analytical expression of the size distribution in the form of a lognormal type distribution. We apply our results to the grain size distribution of solid phase crystallized Si-films.Comment: four pages, one figur

Free polyethylenimine enhances substrate-mediated gene delivery on titanium substrates modified with RGD-functionalized poly(acrylic acid) brushes

Substrate mediated gene delivery (SMD) is a method of immobilizing DNA complexes to a substrate via covalent attachment or nonspecific adsorption, which allows for increased transgene expression with less DNA compared to traditional bolus delivery. It may also increase cells receptivity to transfection via cell-material interactions. Substrate modifications with poly(acrylic) acid (PAA) brushes may improve SMD by enhancing substrate interactions with DNA complexes via tailored surface chemistry and increasing cellular adhesion via moieties covalently bound to the brushes. Previously, we described a simple method to graft PAA brushes to Ti and further demonstrated conjugation of cell adhesion peptides (i.e., RGD) to the PAA brushes to improve biocompatibility. The objective of this work was to investigate the ability of Ti substrates modified with PAA-RGD brushes (PAA-RGD) to immobilize complexes composed of branched polyethyleneimine and DNA plasmids (bPEI-DNA) and support SMD in NIH/3T3 fibroblasts. Transfection in NIH/3T3 cells cultured on bPEI-DNA complexes immobilized onto PAA-RGD substrates was measured and compared to transfection in cells cultured on control surfaces with immobilized complexes including Flat Ti, PAA brushes modified with a control peptide (RGE), and unmodified PAA. Transfection was two-fold higher in cells cultured on PAA-RGD compared to those cultured on all control substrates. While DNA immobilization measured with radiolabeled DNA indicated that all substrates (PAA-RGD, unmodified PAA, Flat Ti) contained nearly equivalent amounts of loaded DNA, ellipsometric measurements showed that more total mass (i.e., DNA and bPEI, both complexed and free) was immobilized to PAA and PAA-RGD compared to Flat Ti. The increase in adsorbed mass may be attributed to free bPEI, which has been shown to improve transfection. Further transfection investigations showed that removing free bPEI from the immobilized complexes decreased SMD transfection and negated any differences in transfection success between cells cultured on PAA-RGD and on control substrates, suggesting that free bPEI may be beneficial for SMD in cells cultured on bPEI-DNA complexes immobilized on PAA-RGD grafted to Ti. This work demonstrates that substrate modification with PAA-RGD is a feasible method to enhance SMD outcomes on Ti and may be used for future applications such as tissue engineering, gene therapy, and diagnostics. © 2019 Mantz, Rosenthal, Farris, Kozisek, Bittrich, Nazari, Schubert, Schubert, Stamm, Uhlmann and Pannier

Neurochemical Changes in the Mouse Hippocampus Underlying the Antidepressant Effect of Genetic Deletion of P2X7 Receptors.

Recent investigations have revealed that the genetic deletion of P2X7 receptors (P2rx7) results in an antidepressant phenotype in mice. However, the link between the deficiency of P2rx7 and changes in behavior has not yet been explored. In the present study, we studied the effect of genetic deletion of P2rx7 on neurochemical changes in the hippocampus that might underlie the antidepressant phenotype. P2X7 receptor deficient mice (P2rx7-/-) displayed decreased immobility in the tail suspension test (TST) and an attenuated anhedonia response in the sucrose preference test (SPT) following bacterial endotoxin (LPS) challenge. The attenuated anhedonia was reproduced through systemic treatments with P2rx7 antagonists. The activation of P2rx7 resulted in the concentration-dependent release of [3H]glutamate in P2rx7+/+ but not P2rx7-/- mice, and the NR2B subunit mRNA and protein was upregulated in the hippocampus of P2rx7-/- mice. The brain-derived neurotrophic factor (BDNF) expression was higher in saline but not LPS-treated P2rx7-/- mice; the P2rx7 antagonist Brilliant blue G elevated and the P2rx7 agonist benzoylbenzoyl ATP (BzATP) reduced BDNF level. This effect was dependent on the activation of NMDA and non-NMDA receptors but not on Group I metabotropic glutamate receptors (mGluR1,5). An increased 5-bromo-2-deoxyuridine (BrdU) incorporation was also observed in the dentate gyrus derived from P2rx7-/- mice. Basal level of 5-HT was increased, whereas the 5HIAA/5-HT ratio was lower in the hippocampus of P2rx7-/- mice, which accompanied the increased uptake of [3H]5-HT and an elevated number of [3H]citalopram binding sites. The LPS-induced elevation of 5-HT level was absent in P2rx7-/- mice. In conclusion there are several potential mechanisms for the antidepressant phenotype of P2rx7-/- mice, such as the absence of P2rx7-mediated glutamate release, elevated basal BDNF production, enhanced neurogenesis and increased 5-HT bioavailability in the hippocampus

Association Study between BDNF Gene Polymorphisms and Autism by Three-Dimensional Gel-Based Microarray

Single nucleotide polymorphisms (SNPs) are important markers which can be used in association studies searching for susceptible genes of complex diseases. High-throughput methods are needed for SNP genotyping in a large number of samples. In this study, we applied polyacrylamide gel-based microarray combined with dual-color hybridization for association study of four BDNF polymorphisms with autism. All the SNPs in both patients and controls could be analyzed quickly and correctly. Among four SNPs, only C270T polymorphism showed significant differences in the frequency of the allele (χ2 = 7.809, p = 0.005) and genotype (χ2 = 7.800, p = 0.020). In the haplotype association analysis, there was significant difference in global haplotype distribution between the groups (χ2 = 28.19, p = 3.44e-005). We suggest that BDNF has a possible role in the pathogenesis of autism. The study also show that the polyacrylamide gel-based microarray combined with dual-color hybridization is a rapid, simple and high-throughput method for SNPs genotyping, and can be used for association study of susceptible gene with disorders in large samples