1,083 research outputs found

    Cloning of mouse integrin alphaV cDNA and role of the alphaV-related matrix receptors in metanephric development.

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    Metanephrogenesis has been a long-standing model to study cell-matrix interactions. A number of adhesion molecules, including matrix receptors (i.e., integrins), are believed to be involved in such interactions. The integrins contain alpha and beta s ubunits and are present in various tissues in different heterodimeric forms. In this study, one of the members of the integrin superfamily, alphaV, was characterized, and its relevance in murine nephrogenesis was investigated. Mouse embryonic renal cDNA libraries were prepared and screened for alphaV, and multiple clones were isolated and sequenced. The deduced amino acid sequence of the alpha-v cDNA clones and hydropathic analysis revealed that it has a typical signal sequence and extracellular, transmembrane, and cytoplasmic domains, with multiple Ca2+ binding sites. No A(U)nA mRNA instability motifs were present. Conformational analysis revealed no rigid long-range-ordered structure in murine alphaV. The alphaV was expressed in the embryonic kidney at day 13 of the gestation, with a transcript size of approximately 7 kb. Its expression increased progressively during the later gestational stages and in the neonatal period. It was distributed in the epithelial elements of developing nephrons and was absent in the uninduced mesenchyme. In mature metanephroi, the expression was relatively high in the glomeruli and blood vessels, as compared to the tubules. Various heterodimeric associations of alphaV, i.e., with beta1, beta3, beta5, and beta6, were observed in metanephric tissues. Inclusion of alphaV-antisense-oligodeoxynucleotide or -antibody in metanephric culture induced dysmorphogenesis of the kidney with reduced population of the nephrons, disorganization of the ureteric bud branches, and reduction of mRNA and protein expressions of alphaV. The expressions of integrin beta3, beta5, and beta6 were unaltered. These findings suggest that the integrin alphaV is developmentally regulated, has a distinct spatio-temporal expression, and is relevant in the mammalian organogenesis

    A microfluidic electroosmotic mixer and the effect of potential and frequency on its mixing efficiency

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    This paper presents the design and numerical simulation of a T-shape microfluidic electroosmotic micromixer. It is equipped with six microelectrodes that are embedded in the side surfaces of the microchannel. The electrode array consists of two sets of three 20 &Acirc;&iquest;m and 60 &Acirc;&iquest;m microelectrodes arranged in the form of two opposing triangles. Numerical analysis of electric potential and frequency effects on mixing efficiency of the micromixer is carried out by means of two sets of simulations. First, the electric potential is kept at 2 V while the frequency is varied within 10-50 Hz. The highest achieved mixing efficiency is 96% at 22 Hz. Next, the frequency is kept at 30 Hz whilst the electric potential is varied within 1-5 V. The best achieved mixing efficiency is 97% at 3 V.<br /

    Confined Charged Particles in C-periodic Volumes

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    Charged particles in an Abelian Coulomb phase are non-local infraparticles that are surrounded by a cloud of soft photons which extends to infinity. Gauss' law prevents the existence of charged particles in a periodic volume. In a CC-periodic volume, which is periodic up to charge conjugation, on the other hand, charged particles can exist. This includes vortices in the 33-d XY-model, magnetic monopoles in 44-d U(1)\mathrm{U}(1) gauge theory, as well as protons and other charged particles in QCD coupled to QED. In four dimensions non-Abelian charges are confined. Hence, in an infinite volume non-Abelian infraparticles cost an infinite amount of energy. However, in a CC-periodic volume non-Abelian infraparticles (whose energy increases linearly with the box size) can indeed exist. Investigating these states holds the promise of deepening our understanding of confinement.Comment: Proceedings for the 39th International Symposium on Lattice Field Theory, LATTICE202

    A new type of lattice gauge theory through self-adjoint extensions

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    A generalization of Wilsonian lattice gauge theory may be obtained by considering the possible self-adjoint extensions of the electric field operator in the Hamiltonian formalism. In the special case of 3D U(1) gauge theory these are parametrised by a phase θ, and the ordinary Wilson theory is recovered for θ=0. We consider the case θ=π, which, upon dualization, turns into a theory of staggered integer and half-integer height variables. We investigate order parameters for the breaking of the relevant symmetries, and thus study the phase diagram of the theory, which shows evidence of a broken ℤ2 symmetry in the continuum limit, in contrast to the ordinary theory

    Chimeric aptamers in cancer cell-targeted drug delivery

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    Aptamers are single-stranded structured oligonucleotides (DNA or RNA) that can bind to a wide range of targets ("apatopes") with high affinity and specificity. These nucleic acid ligands, generated from pools of random-sequence by an in vitro selection process referred to as systematic evolution of ligands by exponential enrichment (SELEX), have now been identified as excellent tools for chemical biology, therapeutic delivery, diagnosis, research, and monitoring therapy in real-time imaging. Today, aptamers represent an interesting class of modern Pharmaceuticals which with their low immunogenic potential mimic extend many of the properties of monoclonal antibodies in diagnostics, research, and therapeutics. More recently, chimeric aptamer approach employing many different possible types of chimerization strategies has generated more stable and efficient chimeric aptamers with aptamer-aptamer, aptamer-nonaptamer biomacromolecules (siRNAs, proteins) and aptamer-nanoparticle chimeras. These chimeric aptamers when conjugated with various biomacromolecules like locked nucleic acid (LNA) to potentiate their stability, biodistribution, and targeting efficiency, have facilitated the accurate targeting in preclinical trials. We developed LNA-aptamer (anti-nucleolin and EpCAM) complexes which were loaded in iron-saturated bovine lactofeerin (Fe-blf)-coated dopamine modified surface of superparamagnetic iron oxide (Fe3O4) nanoparticles (SPIONs). This complex was used to deliver the specific aptamers in tumor cells in a co-culture model of normal and cancer cells. This review focuses on the chimeric aptamers, currently in development that are likely to find future practical applications in concert with other therapeutic molecules and modalities

    Mapping genomic and transcriptomic alterations spatially in epithelial cells adjacent to human breast carcinoma.

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    Almost all genomic studies of breast cancer have focused on well-established tumours because it is technically challenging to study the earliest mutational events occurring in human breast epithelial cells. To address this we created a unique dataset of epithelial samples ductoscopically obtained from ducts leading to breast carcinomas and matched samples from ducts on the opposite side of the nipple. Here, we demonstrate that perturbations in mRNA abundance, with increasing proximity to tumour, cannot be explained by copy number aberrations. Rather, we find a possibility of field cancerization surrounding the primary tumour by constructing a classifier that evaluates where epithelial samples were obtained relative to a tumour (cross-validated micro-averaged AUC = 0.74). We implement a spectral co-clustering algorithm to define biclusters. Relating to over-represented bicluster pathways, we further validate two genes with tissue microarrays and in vitro experiments. We highlight evidence suggesting that bicluster perturbation occurs early in tumour development

    Variability Across Implanting Centers in Short and Long-Term Mortality and Adverse Events in Patients on HeartMate 3 Support: A Momentum 3 Secondary Analysis

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    Purpose: We aimed to characterize center-specific variability in HeartMate 3 (HM3) patient survival within the MOMENTUM 3 studies and to examine the correlation between implanting center survival and major adverse events (AEs). Methods: Center HM3 implant volume during the MOMENTUM 3 pivotal (n=515) and continued access protocol (n=1685) trials were tallied. Centers implanting ≤16 HM3 patients (25th percentile) were excluded. De-identified center variability in mortality was assessed at 90 days and 2 years using direct adjusted survival while accounting for key baseline risk factors. The 90-day frequency and 2-year rates of stroke, bleeding, and infection were compared across centers and correlations between survival and event rate variability were assessed. Results: Among 48 centers, 1957 HM3 patients were included in this analysis with site implants ranging between 17 to 103 patients. Patient cohorts differed across the sites by age (average 52-68 years), sex (60-95% male), destination therapy intent (25-100%), and %INTERMACS profile 1-2 (2-81%). At 90 days, center adjusted median mortality was 6.5%, nadiring at ≤3.2% (25th percentile) and peaking at ≥10.5% (75th percentile). Median 2-year center adjusted mortality was 18.6%, nadiring at ≤14.0% and peaking at ≥25.2% (figure A). AEs were also highly variable across centers; centers with low mortality tended to have lower AE rates at 2 years (figure B). Conclusion: Patient characteristics and outcomes were highly variable across MOMENTUM 3 centers despite trial preoperative inclusion/exclusion criteria. Many centers had exemplary risk-adjusted HM3 patient outcomes. Studies are needed to improve our understanding of top performing centers’ best practices as they relate to HM3 care in the pre, interoperative, and chronic support stages in an effort to further improve HM3 LVAD-associated clinical outcomes

    Concomitant Valvular Procedures During LVAD Implantation and Outcomes: An Analysis of the MOMENTUM 3 Trial Portfolio

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    Purpose: Correction of valvular pathology is often undertaken in patients undergoing LVAD implantation but impact on outcomes is uncertain. We compared clinical outcomes with HeartMate 3 (HM3) LVAD implantation in those with concurrent valve procedures (VP) to those with an isolated LVAD implant within the MOMENTUM3 trial portfolio, including the Pivotal Trial (n=515, NCT02224755) and Continued Access Protocol/ CAP (n=1685, NCT02892955). Methods: The study included 2200 HM3 implanted patients. Among 820 concurrent procedures (including VP, CABG, RVAD, LAA closure), 466 (21.8%) were VPs (HM3+VP), including 81 aortic, 61 mitral, 163 tricuspid, and 85 patients with multiple VPs. Short and Long-term outcomes including peri-operative complications and healthcare resource use, major adverse events and survival were analyzed. Results: Patients undergoing HM3+VP were older (63[54-70] vs. 62[52-68] yrs), with a sicker INTERMACS profile (1-2:41% vs.31%) and higher central venous pressure (11[8-16] vs. 9[6-14] mmHg) compared to HM3 alone (all p\u3c0.05). The cardiopulmonary bypass time (124[97-158] vs.76[59-96] mins); ICU (8.5 [5-16] vs. 7 [5-13]) and hospital length of stay (20 [15-30] vs. 18 [14-24] days) were longer in HM3+VP (all p\u3c0.0001). A significantly higher incidence of stroke (4.9% vs. 2.4%), bleeding (33.9% vs. 23.8%) and right heart failure (41.5% vs. 29.6%) was noted in HM3+VP for 0-30 days post-implant (all p\u3c0.01), but 30-day survival was similar between groups (96.7% vs. 96.1%). There was no difference in 2-year survival in HM3+VP vs HM3 alone patients (HR[95%CI]:0.93 [0.71-1.21];p=0.60). Analysis of individual VPs showed no significant differences in survival compared to HM3 alone (Figure). Conclusion: Concurrent VPs are commonly performed during LVAD implantation, are associated with increased morbidity during the index hospitalization, but short and long-term survival are not impacted adversely when compared with those that undergo an isolated LVAD procedure
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