64 resultados para Nano Technology
Resumo:
Focal therapy in prostate cancer aims to treat only the part of the gland harboring clinically significant disease while preserving the rest of the tissue. This approach may substantially reduce treatment-related toxicity without compromising disease control outcomes. Short- to medium-term functional and oncological results in prospective interventional studies are promising, but comparative effectiveness research against standard of care is required to incorporate focal therapy among standard options. In this review, we discuss the actual stage of assessment and results of sources of energy commonly used to deliver focal therapy. We also provide our viewpoint on how the field will evolve in the near future.
Resumo:
BACKGROUND/AIMS: The present report examines a new pig model for progressive induction of high-grade stenosis, for the study of chronic myocardial ischemia and the dynamics of collateral vessel growth. METHODS: Thirty-nine Landrace pigs were instrumented with a novel experimental stent (GVD stent) in the left anterior descending coronary artery. Eight animals underwent transthoracic echocardiography at rest and under low-dose dobutamine. Seven animals were examined by nuclear PET and SPECT analysis. Epi-, mid- and endocardial fibrosis and the numbers of arterial vessels were examined by histology. RESULTS: Functional analysis showed a significant decrease in global left ventricular ejection fraction (24.5 +/- 1.6%) 3 weeks after implantation. There was a trend to increased left ventricular ejection fraction after low-dose dobutamine stress (36.0 +/- 6.6%) and a significant improvement of the impaired regional anterior wall motion. PET and SPECT imaging documented chronic hibernation. Myocardial fibrosis increased significantly in the ischemic area with a gradient from epi- to endocardial. The number of arterial vessels in the ischemic area increased and coronary angiography showed abundant collateral vessels of Rentrop class 1. CONCLUSION: The presented experimental model mimics the clinical situation of chronic myocardial ischemia secondary to 1-vessel coronary disease.
Resumo:
Abstract In this thesis we present the design of a systematic integrated computer-based approach for detecting potential disruptions from an industry perspective. Following the design science paradigm, we iteratively develop several multi-actor multi-criteria artifacts dedicated to environment scanning. The contributions of this thesis are both theoretical and practical. We demonstrate the successful use of multi-criteria decision-making methods for technology foresight. Furthermore, we illustrate the design of our artifacts using build and-evaluate loops supported with a field study of the Swiss mobile payment industry. To increase the relevance of this study, we systematically interview key Swiss experts for each design iteration. As a result, our research provides a realistic picture of the current situation in the Swiss mobile payment market and reveals previously undiscovered weak signals for future trends. Finally, we suggest a generic design process for environment scanning.
Resumo:
This review covers the latest developments of long synthetic peptide technology for the rapid identification and development of malaria vaccine candidates and immunological modulators. A brief description of the two most common solid-phase synthetic procedures, together with the latest advances in optimisation of peptide chain assembly and analytical instrumentation, is given, with special attention to non-specialists. Several examples of vaccine candidates developed in the authors' or their collaborators' laboratories are also provided.
Resumo:
Context: Ovarian tumors (OT) typing is a competency expected from pathologists, with significant clinical implications. OT however come in numerous different types, some rather rare, with the consequence of few opportunities for practice in some departments. Aim: Our aim was to design a tool for pathologists to train in less common OT typing. Method and Results: Representative slides of 20 less common OT were scanned (Nano Zoomer Digital Hamamatsu®) and the diagnostic algorithm proposed by Young and Scully applied to each case (Young RH and Scully RE, Seminars in Diagnostic Pathology 2001, 18: 161-235) to include: recognition of morphological pattern(s); shortlisting of differential diagnosis; proposition of relevant immunohistochemical markers. The next steps of this project will be: evaluation of the tool in several post-graduate training centers in Europe and Québec; improvement of its design based on evaluation results; diffusion to a larger public. Discussion: In clinical medicine, solving many cases is recognized as of utmost importance for a novice to become an expert. This project relies on the virtual slides technology to provide pathologists with a learning tool aimed at increasing their skills in OT typing. After due evaluation, this model might be extended to other uncommon tumors.
Resumo:
Optimal vaccine strategies must be identified for improving T-cell vaccination against infectious and malignant diseases. MelQbG10 is a virus-like nano-particle loaded with A-type CpG-oligonucleotides (CpG-ODN) and coupled to peptide(16-35) derived from Melan-A/MART-1. In this phase IIa clinical study, four groups of stage III-IV melanoma patients were vaccinated with MelQbG10, given (i) with IFA (Montanide) s.c.; (ii) with IFA s.c. and topical Imiquimod; (iii) i.d. with topical Imiquimod; or (iv) as intralymph node injection. In total, 16/21 (76%) patients generated ex vivo detectable Melan-A/MART-1-specific T-cell responses. T-cell frequencies were significantly higher when IFA was used as adjuvant, resulting in detectable T-cell responses in all (11/11) patients, with predominant generation of effector-memory-phenotype cells. In turn, Imiquimod induced higher proportions of central-memory-phenotype cells and increased percentages of CD127(+) (IL-7R) T cells. Direct injection of MelQbG10 into lymph nodes resulted in lower T-cell frequencies, associated with lower proportions of memory and effector-phenotype T cells. Swelling of vaccine site draining lymph nodes, and increased glucose uptake at PET/CT was observed in 13/15 (87%) of evaluable patients, reflecting vaccine triggered immune reactions in lymph nodes. We conclude that the simultaneous use of both Imiquimod and CpG-ODN induced combined memory and effector CD8(+) T-cell responses.
Resumo:
We present a viscometric affinity biosensor that can potentially allow continuous multi-analyte monitoring in biological fluids like blood or plasma. The sensing principle is based on the detection of viscosity changes of a polymeric solution which has a selective affinity for the analyte of interest. The chemico-mechanical sensor incorporates an actuating piezoelectric diaphragm, a sensing piezoelectric diaphragm and a flow-resisting microchannel for viscosity detection. A free-standing Anodic Alumina Oxide (AAO) porous nano-membrane is used as selective interface. A glucose-sensitive sensor was fabricated and extensively assessed in buffer solution. The sensor reversibility, stability and sensitivity were excellent during at least 65 hours. Results showed also a good degree of stability for a long term measurement (25 days). The sensor behaviour was furthermore tested in fetal bovine serum (FBS). The obtained results for glucose sensing are very promising, indicating that the developed sensor is a candidate for continuous monitoring in biological fluids. Sensitive solutions for ionized calcium and pH are currently under development and should allow multi-analyte sensing in the near future.
Resumo:
The antibody display technology (ADT) such as phage display (PD) has substantially improved the production of monoclonal antibodies (mAbs) and Ab fragments through bypassing several limitations associated with the traditional approach of hybridoma technology. In the current study, we capitalized on the PD technology to produce high affinity single chain variable fragment (scFv) against tumor necrosis factor-alpha (TNF- α), which is a potent pro-inflammatory cytokine and plays important role in various inflammatory diseases and malignancies. To pursue production of scFv antibody fragments against human TNF- α, we performed five rounds of biopanning using stepwise decreased amount of TNF-α (1 to 0.1 μ g), a semi-synthetic phage antibody library (Tomlinson I + J) and TG1 cells. Antibody clones were isolated and selected through enzyme-linked immunosorbent assay (ELISA) screening. The selected scFv antibody fragments were further characterized by means of ELISA, PCR, restriction fragment length polymorphism (RFLP) and Western blot analyses as well as fluorescence microscopy and flow cytometry. Based upon binding affinity to TNF-α , 15 clones were selected out of 50 positive clones enriched from PD in vitro selection. The selected scFvs displayed high specificity and binding affinity with Kd values at nm range to human TNF-α . The immunofluorescence analysis revealed significant binding of the selected scFv antibody fragments to the Raji B lymphoblasts. The effectiveness of the selected scFv fragments was further validated by flow cytometry analysis in the lipopolysaccharide (LPS) treated mouse fibroblast L929 cells. Based upon these findings, we propose the selected fully human anti-TNF-α scFv antibody fragments as potential immunotherapy agents that may be translated into preclinical/clinical applications.
Resumo:
Proteins can switch between different conformations in response to stimuli, such as pH or temperature variations, or to the binding of ligands. Such plasticity and its kinetics can have a crucial functional role, and their characterization has taken center stage in protein research. As an example, Topoisomerases are particularly interesting enzymes capable of managing tangled and supercoiled double-stranded DNA, thus facilitating many physiological processes. In this work, we describe the use of a cantilever-based nanomotion sensor to characterize the dynamics of human topoisomerase II (Topo II) enzymes and their response to different kinds of ligands, such as ATP, which enhance the conformational dynamics. The sensitivity and time resolution of this sensor allow determining quantitatively the correlation between the ATP concentration and the rate of Topo II conformational changes. Furthermore, we show how to rationalize the experimental results in a comprehensive model that takes into account both the physics of the cantilever and the dynamics of the ATPase cycle of the enzyme, shedding light on the kinetics of the process. Finally, we study the effect of aclarubicin, an anticancer drug, demonstrating that it affects directly the Topo II molecule inhibiting its conformational changes. These results pave the way to a new way of studying the intrinsic dynamics of proteins and of protein complexes allowing new applications ranging from fundamental proteomics to drug discovery and development and possibly to clinical practice.
Resumo:
In the Arabidopsis thaliana genome, over 1000 putative genes encoding small, presumably secreted, signalling peptides can be recognized. However, a major obstacle in identifying the function of genes encoding small signalling peptides is the limited number of available loss-of-function mutants. To overcome this, a promising new tool, antagonistic peptide technology, was recently developed. Here, this antagonistic peptide technology was tested on selected CLE peptides and the related IDA peptide and its usefulness in the context of studies of peptide function discussed. Based on the analyses, it was concluded that the antagonistic peptide approach is not the ultimate means to overcome redundancy or lack of loss-of-function lines. However, information collected using antagonistic peptide approaches (in the broad sense) can be very useful, but these approaches do not work in all cases and require a deep insight on the interaction between the ligand and its receptor to be successful. This, as well as peptide ligand structure considerations, should be taken into account before ordering a wide range of synthetic peptide variants and/or generating transgenic plants.