siRNA Targeting of Thymidylate Synthase, Thymidine Kinase 1 and Thymidine Kinase 2 as an Anticancer Therapy: A Combinatorial RNAi Approach

Thymidylate synthase (TS) is the only de novo source of thymidylate (dTMP) for DNA synthesis and repair. Drugs targeting TS protein are a mainstay in cancer treatment but off-target effects and toxicity limit their use. Cytosolic thymidine kinase (TK1) and mitochondrial thymidine kinase (TK2) contribute to an alternative dTMP-producing pathway, by salvaging thymidine from the tumour milieu, and may modulate resistance to TS-targeting drugs. We have previously shown that TS antisense molecules (oligodeoxynucleotides, ODNs, and small interfering siRNA, siRNA) sensitize tumour cells, both in vitro and in vivo, to TS targeting drugs. As both TS and TKs contribute to cellular dTMP, we hypothesized that TKs mediate resistance to the capacity of TS siRNA to sensitize tumour cells to TS-targeting drugs. Downregulation of TKs with siRNA enhanced the capacity of TS siRNA to sensitize tumour cells to traditional TS protein-targeting drugs (5FUdR and pemetrexed). Combined downregulation of these enzymes is an attractive strategy to enhance TS-targeted anticancer therapy. TK2 can phosphorylate both thymidine and deoxycytidine to generate dTMP and dCMP, precursors for dTTP and dCTP, respectively. dCTP negatively regulates deoxycytidine kinase (dCK), another enzyme that phosphorylates deoxycytidine as well as the anticancer drug gemcitabine. Antisense knockdown of TK2 could reduce TK2-produced dCMP, thus decreasing dCTP levels and inhibition of dCK, and lead to increased dCK activity, gemcitabine activation, and anticancer effectiveness. Given the substrate promiscuity of TK2, we hypothesized that: (1) TK2 can mediate human tumour cell resistance to gemcitabine, (2) antisense downregulation of TK2 can overcome that resistance, and (3) TK2 siRNA-induced drug sensitization results in mitochondrial damage. siRNA downregulation of TK2 expression sensitized MCF7 and HeLa cells to gemcitabine, but did not sensitize A549 cells (low TK2 expresser). Treatment with TK2 siRNA and gemcitabine: 1) decreased mitochondrial redox status, 2) decreased mitochondrial DNA (mtDNA:nDNA ratio), and 3) decreased mitochondrial activity. This is the first demonstration of a direct role for TK2 in gemcitabine resistance, or any independent role in cancer drug resistance, and further distinguishes TK2 from other dTMP-producing enzymes

A mixed methods study on choice of media influence on construction industry communication

This study focuses on the use of different communication media for solving problems in the construction industry. The focus of this research is on design-problems containing spatial information and are informally reported between site supervision and design professionals. Due to the fragmented nature of the construction industry, miscommunication is a well-known and common problem. Yet, this fragmented nature is necessary in order to build a complex product involving many different types of professionals. To better understand the issue, this study uses previous literature, such as those published on media richness theory, problem-solving strategy, and construction specific communications, in a three-phased sequential mixed-methods approach. The phases included an online survey with industry professionals (phase 1), interviews with industry professionals (phase 2), and a quasi-experiment (phase 3). Quantitative and qualitative data were analyzed depending on the phase. Results indicate that construction industry communication relies strongly on face-to-face interaction, and telephone and email communications. The need for a `paper trail\u27 is an important factor driving communication patterns. Finally, phase 3 suggested that communication media that allow for immediate feedback and visual cues are more helpful in solving design-problems containing spatial information. Based on these results, guidelines for effective use of different types of media in the construction industry were then developed as a final product of this study. These guidelines seek to improve awareness about the importance of effective communication in the construction industry

"Reporting of Two or More Races in the 1999 American Community Survey"

This paper investigates the causes of western Germany's remarkably poor performance since 1992. The paper challenges the view that the poor record of the nineties, particularly the marked deterioration in public finances since unification, might be largely attributable to unification. Instead, the analysis highlights the role of ill-timed and overly ambitious fiscal consolidation in conjunction with tight monetary policies of an exceptional length and degree. The issue of fiscal sustainability and Germany's fiscal and monetary policies are assessed both in the light of economic theory and in comparison to the best practices of other more successful countries. The analysis concludes that Germany's dismal record of the nineties must not be seen as a direct and apparently inevitable result of unification. Rather, the record arose as a perfectly unnecessary consequence of unsound macro demand policies conducted under the Bundesbank's dictate in response to it, policies that caused the severe and protracted de-stabilization of western Germany in the first place.

Reporting of Two or More Races In the 1999 American Community Survey

This study presents data on race, collected at selected sites throughout the country for the 1999 American Community Survey (ACS). In particular, the distribution of the population by race and Hispanic or Latino origin is examined, as are the reporting of multiple races, number of races, and major race combinations and the extent to which the race and Hispanic/Latino questions were not answered. Although the ACS sites were not intended to be a nationally representative sample, the study's results provide important insights into what might be learned from Census 2000.

Nanopatterning of Recombinant Proteins and Viruses Using Block Copolymer Templates

The study of interfaces is important in understanding biological interactions, including cellular signaling and virus infection. This thesis is an original effort to examine the interaction between a block copolymer and both a protein and a virus. Block copolymers intrinsically form nanometer-scale structures over large areas without expensive processing, making them ideal for the synthesis of the nanopatterned surfaces used in this study. The geometry of these nanostructures can be easily tuned for different applications by altering the block ratio and composition of the block copolymer. Block copolymers can be used for controlled uptake of metal ions, where one block selectively binds metal ions while the other does not. 5-norbornene-2,3-dicarboxylic acid is synthesized through ringopening metathesis polymerization. It formed spherical domains with spheres approximately 30 nm in diameter, and these spheres were then subsequently loaded with nickel ion. This norbornene block copolymer was tested for its ability to bind histidine-tagged green fluorescent protein (hisGFP), and it was found that the nickel-loaded copolymer was able to retain hisGFP through chelation between the histidine tag and the metal-containing portions of the copolymer surface. Poly(styrene-b-4-vinylpyridine) (PS/P4VP) was also loaded with nickel, forming a cylindrical microstructure. The binding of Tobacco mosaic virus and Tobacco necrosis virus was tested through Tween 20 detergent washes. Electron microscopy allowed for observation of both block copolymer nanostructures and virus particles. Results showed that Tween washes could not remove bound Tobacco mosaic virus from the surface of PS/P4VP. It was also seen that The size and tunability of block copolymers and the lack of processing needed to attain different structures makes them attractive for many applications, including microfluidic devices, surfaces to influence cellular signaling and growth, and as a nanopatterning surface for organized adhesion

Spina bifida—ultrasonographic diagnosis in first and second trimesters

Accurate and timely prenatal diagnosis of spina bifida (SB) is a major challenge of actual antenatal care. The diagnosis of spina bifida may be only suspected during I trimester because the detection rate of intracranial traslucency is 50%; the final diagnosis is made in the II trimester by direct visualization of defect of spine or the presence of myelomeningocele or the visualization of indirect signs. When a spine defect is detected it is necessary a neurosurgical counseling with the patient .The degree of handicap and the survival rate depend on the level of injury, the size of the defect, and the presence of associated anomalies. In tertiary fetal medicine centers, two-dimensional (2D) and three-dimensional (3D) ultrasound allows an accurate determination of the location, type, extention of the defect. Maternal—fetal surgery for myelomeningocele repair must be offered to carefully selected patients even if there are significant maternal implications and complication

Reporting of two or more races in the 1999 American community survey

This paper investigates the causes of western Germany's remarkably poor performance since 1992. The paper challenges the view that the poor record of the nineties, particularly the marked deterioration in public finances since unification, might be largely attributable to unification. Instead, the analysis highlights the role of ill-timed and overly ambitious fiscal consolidation in conjunction with tight monetary policies of an exceptional length and degree. The issue of fiscal sustainability and Germany's fiscal and monetary policies are assessed both in the light of economic theory and in comparison to the best practices of other more successful countries. The analysis concludes that Germany's dismal record of the nineties must not be seen as a direct and apparently inevitable result of unification. Rather, the record arose as a perfectly unnecessary consequence of unsound macro demand policies conducted under the Bundesbank's dictate in response to it, policies that caused the severe and protracted de-stabilization of western Germany in the first place

A multifunctional phosphite-containing electrolyte for 5 V-class LiNi 0.5Mn1.5O4 cathodes with superior electrochemical performance

We report a highly promising organophosphorus compound with an organic substituent, tris(trimethylsilyl)phosphite (TMSP), to improve the electrochemical performance of 5 V-class LiNi0.5Mn 1.5O4 cathode materials. Our investigation reveals that TMSP alleviates the decomposition of LiPF6 by hydrolysis, effectively eliminates HF promoting Mn/Ni dissolution from the cathode, and forms a protective layer on the cathode surface against severe electrolyte decomposition at high voltages. Remarkable improvements in the cycling stability and rate capability of high voltage cathodes were achieved in the TMSP-containing electrolyte. After 100 cycles at 60 ??C, the discharge capacity retention was 73% in the baseline electrolyte, whereas the TMSP-added electrolyte maintained 90% of its initial discharge capacity. In addition, the LiNi 0.5Mn1.5O4 cathode with TMSP delivers a superior discharge capacity of 105 mA h g-1 at a high rate of 3 C and an excellent capacity retention of 81% with a high coulombic efficiency of over 99.6% is exhibited for a graphite/LiNi0.5Mn1.5O 4 full cell after 100 cycles at 30 ??C.close8