Several polycations such as polylysine polymers are efficient transfection agents due to their capacity to bind DNA at physiological pH. By linking a ligand for a cell surface receptor to the ...polycation domain, a selective delivery of polyanionic compounds such as oligodeoxynucleotides (ODNs) without cell membrane-disruption can be achieved. Therefore, we aimed to develop this strategy to improve the uptake of oligomers in cancer cells. In particular, cationic polymers polylysine were covalently linked to a molecule of Folic Acid (FA) to deliver complexed ODNs in human melanoma (M-14) cells which express FA receptors. Since in these cells c-myc oncogene seems to play a crucial role in tumor growth, we used a c-myc antisense ODNs (15mer base antisense c-myc ODNs phosphorothioate) to inhibit its expression. The cellular uptake of the complexed ODNs was improved compared to the cellular uptake of free ODNs with a significant decrease in the intracellular c-myc protein level, resulting in a reduction of the growth rate and colony-forming capacity of the cells. No such effect was observed when ODNs in scrambled sequences were administered under the same experimental conditions. The efficacy of the uptake of the complex is receptor-related since a Transferrin-polylysine carrier produced no significant biological effects (in melanoma cells the Fe uptake is mediated by an oxidoreductase present in the cell membrane and not by Transferrin receptor pathway). Our results demonstrate that: a) By choosing the appropriate ligand for the membrane receptor present on the target cells, selective targeting of ODNs can be achieved. b) The uptake of the ODNs can be improved by receptor-mediated endocytosis. c) In a model system the complexed ODNs are capable of impairing gene product synthesis and function.
ADAMTS-4 (aggrecanase-1) is a metalloprotease that plays a role in aggrecan degradation in the cartilage extracellular matrix. In order to understand the regulation of ADAMTS-4 gene expression we ...have cloned and characterized a functional 4.5
kb human ADAMTS-4 promoter. Sequence analysis of the promoter revealed the presence of putative binding sites for nuclear factor of activated T cells (NFAT) and Runx family of transcription factors that are known to regulate chondrocyte maturation and differentiation. Using promoter–reporter assays and mRNA analysis we have analyzed the role of chondrocyte-expressed transcription factors NFATp and Runx2 and have shown that ADAMTS-4 is a potential downstream target of these two factors. Our results suggest that inhibition of the expression/function of NFATp and/or Runx2 may enable us to modulate aggrecan degradation in normal physiology and/or in degenerative joint diseases. The ADAMTS-4 promoter would serve as a valuable mechanistic tool to better understand the regulation of ADAMTS-4 expression by signaling pathways that modulate cartilage matrix breakdown.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A
bstract
The production of beauty and charm quarks in
ep
interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared 5
< Q
2
<
1000 GeV
2
using an integrated ...luminosity of 354 pb
−1
. The beauty and charm content in events with at least one jet have been extracted using the invariant mass of charged tracks associated with secondary vertices and the decay-length significance of these vertices. Differential cross sections as a function of
Q
2
, Bjorken
x
, jet trans- verse energy and pseudorapidity were measured and compared with next-to-leading-order QCD calculations. The beauty and charm contributions to the proton structure functions were extracted from the double-differential cross section as a function of
x
and
Q
2
. The running beauty-quark mass,
m
b
at the scale
m
b
, was determined from a QCD fit at next-to-leading order to HERA data for the first time and found to be
m
b
(
m
b
) = 4.07 ± 0.14 (fit)
− 0.07
+ 0.01
(mod.)
− 0.00
+ 0.05
(param.)
− 0.05
+ 0.08
(theo.) GeV.
Describes student-led research projects conducted at the University of Florida's General Clinical Research Center. First-year medical and M.D.-Ph.D. students collaborate on a hypothesis-driven ...experiment involving students as volunteer subjects and investigators. Feedback indicates students find the program useful and that it encourages pursuit of medical research careers. (EV)
A simultaneous fit of parton distribution functions (PDFs) and electroweak parameters to HERA data on deep inelastic scattering is presented. The input data are the neutral current and charged ...current inclusive cross sections which were previously used in the QCD analysis leading to the HERAPDF2.0 PDFs. In addition, the polarization of the electron beam was taken into account for the ZEUS data recorded between 2004 and 2007. Results on the vector and axial-vector couplings of the Z boson to u- and d-type quarks, on the value of the electroweak mixing angle and the mass of the W boson are presented. The values obtained for the electroweak parameters are in agreement with Standard Model predictions.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The performance of heterojunction organic solar cells is critically dependent on the morphology of the donor and acceptor components in the active film. We report results of photovoltaic devices ...consisting of bilayers and bulk heterojunctions using poly(3-hexylthiophene) (P3HT) and Buckminsterfullerene C60. White light power efficiencies of eta2.2% (bulk heterojunction) and 2.6% (bilayer) were measured after a thermal annealing step on completed devices. Optical and structural investigations on non-annealed bilayer thin films indicated a distinct porosity of the spin-coated polymer, which allows C60 to penetrate the P3HT layer and to touch the anode. This resulted for these bilayer solar cells in the experimental observation that electrons were collected predominantly at the cathode after photo-excitation of P3HT, but predominantly at the anode after C60 excitation. A morphological model to explain the ambipolar charge collection phenomenon is proposed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We evaluated a method for autonomous, user-independent automated border delineation (ABD) developed by Geiser and Wilson, by comparing the accuracy of ABD relative to manual border tracing.
Short ...axis echocardiographic images of 84 patients from 3 clinical sites were analyzed using ABD and by manual tracing performed by two observers at each site and two observers at a core laboratory. The centerline method was used to measure the distance between each pair of computer-generated and hand-traced borders. Cardiac parameters were also measured from all sets of borders: LV area, fractional area change, antero-posterior diameter, wall motion, and wall thickening.
The distance between computer-generated and hand-traced borders was slightly but significantly greater than human interobserver variability between the clinical sites and the core laboratory (0.34+/-0.25 (N = 328) vs. 0.26+/-0.16 (N = 320) cm for the endocardium at end diastole, p = 0.0001). Measurements of LV area and fractional area change were similar by ABD and manual tracing. Other cardiac parameters showed greater deviation between ABD and manually traced borders than between human observers.
Autonomous ABD provides accurate measurements of LV area and area-derived indices. However measurements dependent on border point location deviate more by ABD.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Radiofrequency ablation (RFA) of left‐sided accessory pathways can be achieved using catheters introduced by a retrograde or transseptal approach. Transesophageal echocardiography (TEE) has ...previously been demonstrated to be safe and efficacious in guiding transseptal puncture in patients during mitral valvuloplasty (MV). This study was undertaken to assess the feasibility, safety, and clinical utility of TEE during transsepta! puncture and RFA of left‐sided accessory pathways. Methods: TEE was performed during transseptal puncture in 30 patients (41 ± 12 years, 19 females), 15 patients during attempted RFA of a left‐sided accessory pathway and 15 patients during attempted balloon MV. Results: There was no difference in age, sex distribution, or procedural complications when MV patients were compared to RFA patients. At baseline, left atrial dimension was increased and congestive heart failure was more common when MV patients were compared to RFA patients (P < 0.05) Adequate baseline two‐dimensional and Doppler TEE images were obtained in all patients. One patient sustained mild esophageal bleeding during the TEE, Positioning of the transseptal catheter in the fossa ovalis was facilitated and confirmed by TEE in 29 of 30 cases. One case of cardiac perforation occurred and was associated with inadequate TEE localization of the fossa ovalis. Thrombus was detected on the transseptal catheter by TEE in two cases prior to systemic heparinization. In both cases, thrombus was removed without embolic event. Conclusions: TEE safely guides transseptal puncture in patients undergoing RFA of left‐sided accessory pathways. TEE markers of the fossa ovalis facilitate puncture and may reduce the risk of cardiac perforation particularly in patients with a normal size left atrium. TEE may be especially valuable for identifying thrombus during transseptal puncture.
Diminished cellular responsiveness to transforming growth factor-beta (TGF-beta) is frequently correlated with decreased transcription of the type II receptor for TGF-beta (TGF-beta RII). We have ...cloned and characterized the human TGF-beta RII promoter and, using S1 nuclease mapping and 5' rapid amplification of cDNA ends polymerase chain reaction, have identified five alternative transcription start sites within the region -33 to +57. DNA transfection experiments and electrophoretic mobility shift assays have revealed the existence of five distinct regulatory regions including two positive regulatory elements and two negative regulatory elements in addition to the core promoter region. The first positive regulatory element (-219 to -172) interacts with two distinct nuclear protein complexes, at least one of which appears to be a previously unidentified transcription factor. The second positive regulatory element (+1 to +35) also interacts with two separate protein complexes, both of which appear to be novel transcription factors. Deletion of either positive regulatory element markedly decreased expression of the target gene, suggesting that both positive regulatory elements are necessary for basal expression levels of TGF-beta RII.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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