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Results 451 - 500 of 1261
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Chen Xing - - 2007
Technologies for introducing molecules into living cells are vital for probing the physical properties and biochemical interactions that govern the cell's behavior. Here, we report the development of a nanoscale cell injection system (termed the nanoinjector) that uses carbon nanotubes to deliver cargo into cells. A single multiwalled carbon nanotube ...
Yeo Yoon - - 2007
Conventional treatment options for myocardial infarction are limited by the inability of mature myocardium to regenerate after injury. Although functional improvements after injection of cells and growth factors have been demonstrated, the clinical utility of this procedure has been hampered by poor cell localization, low survival, and rapid clearance of ...
Nizard Philippe - - 2007
Clusterin is a usually secreted glycoprotein with chaperone properties. Recently, it has been suggested that clusterin isoforms reside in the nuclear and cytosolic compartments of human cell types, where they can influence various cellular programs including DNA repair, transcription and apoptosis. Several mechanisms have been proposed to explain this atypical ...
Odenwälder Patrick K - - 2007
Electrohydrodynamic jetting (EHDJ) which is also known as electrosprays (ES) has recently been elucidated as a unique electrified biotechnique for the safe handling and deployment of living organisms. This high intensity electric field driven jetting methodology is now referred to as "bioelectrosprays" (BES). Previously these charged jets have only been ...
alexandra
Bacteriastrum hyalinum cells with spiralling instead of straight setae (chain of cells in girdle view. This image is part of the collection of Dr Gerhard Drebes
Machado, M. D.
In this work, the suitability of live and inactivated cells of a brewing yeast strain of Saccharomyces cerevisiae NCYC1364 in the removal of Cu2+, Ni2+ and Zn2+ from solution was compared. Kinetics studies showed that 30 minutes of the contact of live or dead cells with all the metals were ...
Hirano Makito - - 2007
Early-onset ataxia with ocular motor apraxia and hypoalbuminemia (EAOH)/ataxia with oculomotor apraxia type 1 (AOA1) is caused by mutations in the gene encoding aprataxin (APTX). Although several in vitro findings proposed that impaired enzymatic activities of APTX are responsible for EAOH/AOA1, potential instability of mutant proteins has also been suggested ...
Cirillo Nicola - - 2007
Pemphigus vulgaris (PV) blistering occurs as a result of the disruption of intercellular contacts among keratinocytes, or acantholysis. The hallmark of PV acantholysis in vitro is considered to be the retraction of keratin intermediate filaments (KIF) onto the nucleus, which parallels with loss of cell-cell adhesion and rounding up of ...
Xie Jingwei - - 2007
Entrapment of living cells in microbeads is to protect the encapsulated cells from the host's immune system, which can be used as drug delivery vehicles, immunotherapies and engineered tissues. The main objective of the present study was to investigate the droplet formation and to better develop mono-dispersed microencapsulation of living ...
Ying Liming L Biological Nanoscience Section, National Heart and Lung Institute, Imperial College London, London, UK SW7 2AZ. - - 2007
Cellular heterogeneity and stochastic fluctuation play key roles in biological processes. Single molecule approaches have the key advantage of avoiding ensemble averaging, allowing the observation of transient intermediates and heterogeneity (both static and dynamic). Thus they have revolutionised the way many biological questions are addressed. The challenge ahead is to ...
Wang Min - - 2007
It is expected that intracellular redox activity may closely related to catabolic states of living cells, based on which a mediated electrochemical method has been proposed to measure the ethanol tolerance of the yeast Saccharomyces cerevisiae AS 3800. The couple menadione/ferricyanide was employed as a carrier mediator system, sensing intracellular ...
Tang Hong-Wu - - 2007
We report on the capabilities of near-infrared surface-enhanced Raman scattering (SERS) using gold nanoparticles to obtain detailed chemical information with high spatial resolution from within single cancer cells, living or fixed. Colloidal gold particles, 60 nm in size, were introduced into live human osteosarcoma cells by endocytosis by adding them ...
Tymchenko N - - 2007
In this work, we present a ridged, microfabricated, force sensor that can be used to investigate mechanical interactions between cells exhibiting contact guidance and the underlying cell culture substrate, and a proof-of-function evaluation of the force sensor performance. The substrates contain arrays of vertical pillars between solid ridges that were ...
McNamee Cathy E - - 2007
We investigated the effect of the number of oxyethylene groups (polymer molecular weight) and the interchain binding and/or entanglements of methoxy-terminated-poly(ethylene glycol) (m-PEG) brushes on their ability to adsorb to living malignant melanoma B16F10 cells. We used the atomic force microscope colloid probe method to determine the adhering ability of ...
Benson Micah J MJ Department of Microbiology and Immunology, Dartmouth Medical School, Lebanon, NH 03756, - - 2007
Three possible effector fates await the naïve follicular B cell following antigen stimulation in thymus-dependent reactions. Short-lived plasma cells produce an initial burst of germline-encoded protective antibodies, and long-lived plasma cells and memory B cells arise from the germinal center and function to enhance and sustain the humoral immune response. ...
Niles Andrew L - - 2007
A method to simultaneously determine the relative numbers of live and dead cells in culture by introducing a combination of two fluorogenic substrates or a fluorogenic and a luminogenic protease substrate into the sample is described. The method is based on detection of differential ubiquitous proteolytic activities associated with intact ...
Selenko Philipp - - 2007
In-cell NMR spectroscopy has gained recent popularity since it provides means to analyze the conformational and functional properties of proteins inside living cells and at atomic resolution. High-resolution in-cell NMR spectroscopy was originally established in bacterial cells and based on a rationale that relies on protein over-expression and sample analysis ...
Guigas Gernot - - 2007
We have used fluorescence correlation spectroscopy to determine the anomalous diffusion properties of fluorescently tagged gold beads in the cytoplasm and the nucleus of living cells. From the extracted mean-square displacement v(tau) approximately tau(alpha), we have determined the complex shear modulus G(omega) approximately omega(alpha) for both compartments. Without treatment, all ...
Lapotko Dmitri O DO Laser Cytotechnology Lab, AV Luikov Heat and Mass Transfer Institute, 15 P Brovka Street, Minsk 220072, Belarus. - - 2007
Clusters of nanoparticles may significantly improve the sensitivity of diagnostics and the safety and efficacy of therapeutic nanotechnologies in medicine. We report methods for the formation of nanoparticle clusters and for monitoring their accumulation in cancer cells. The accumulation of gold nanoparticles in tumor cells was studied using flow cytometry, ...
Jobsis Paul D - - 2007
The use of acetoxymethyl (AM) groups to deliver and trap exogenous optical probes inside cells is an established tool in cell biology/physiology, however, these probes have not been used extensively in vivo. In this study, the use of the acetoxymethyl delivery system for optical probes was evaluated, in vivo. Initial ...
Zhu Li - - 2007
Akt is one of the critical mediators in cellular signaling, and overactivation of Akt related pathway frequently occurs in hepatocellular carcinoma (HCC). In this study, we presented that Akt was upregulated in HCC cell lines, and its active phosphorylated form was mainly located in the nucleus. Employing the laser confocal ...
Hanne Halliger
Two cells of the diatom Porosira glacialis, note: size differences between cells in the same live sample. The sample was taken on 01.04.07.
Küttel Claudia - - 2007
Impedance spectroscopy is a powerful tool for label-free analysis and characterisation of living cells. In this work, we achieved the detection of Babesia bovis infected red blood cells using impedance spectroscopy on a microfabricated flow cytometer. The cellular modifications caused by the intracellular parasite result in a shift in impedance ...
Feng Xiaojun - - 2007
This study explores the feasibility of using a bullfrog fibroblast cell line (FT cells) expressing G protein coupled receptors (GPCRs) as the basis for a living cell-based biosensor. We have fabricated gold microelectrode arrays on a silicon dioxide substrate that supports long term, robust growth of the cells at room ...
Yourek Gregory G Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois, - - 2007
Mesenchymal stem cells (MSCs) are progenitors for tissues such as bone and cartilage. In this report, the actin cytoskeleton and nanomechanobiology of human mesenchymal stem cells (hMSCs) were studied using fluorescence microscopy and atomic force microscopy (AFM). Human MSCs were differentiated into chondrocytes and osteoblasts as per previous approaches. Cytochalasin ...
Ramadass Radhan - - 2007
Time- and space-correlated single photon counting method has been used to demonstrate the interactions of cation channel "transient receptor potential vanilloid 4" (TRPV4) and microfilaments. Living cells co-expressing TRPV4-CFP and actin-YFP, when excited for the donor molecules (CFP) exhibited an emission peak at 527 nm and decrease of the lifetime ...
Lai Samuel K - - 2007
The efficacy of many therapeutic molecules could be greatly enhanced by polymer-based nanoparticle systems capable of delivering them to the direct vicinity of the cell nucleus. However, degradation of the particles and encapsulated drugs within the enzyme-rich and low-pH environments of the endo/lysosomal pathway of cells has dramatically limited the ...
Wakabayashi Yoshiyuki - - 2007
Understanding how epithelial cells generate and maintain polarity and function requires live cell imaging. In order for cells to become fully polarized, it is necessary to grow them on a permeable membrane filter; however, the translucent filter obstructs the microscope light path required for quantitative live cell imaging. Alternatively, the ...
Zhang Xiaoli - - 2007
An electrochemical method for quantitative determination of enzyme activity in single cells was developed by scanning a microelectrode (ME) over a nitrocellulose film-covered microreactor with micropores by means of a scanning electrochemical microscope (SECM). Peroxidase (PO) in neutrophils was chosen as the model system. The microreactor consisted of a microwell ...
Johnsson Nils - - 2007
The visualization of biologically relevant molecules and activities inside living cells continues to transform cell biology into a truly quantitative science. However, despite the spectacular achievements in some areas of cell biology, the majority of cellular processes still operate invisibly, not illuminated by even our brightest laser beams. Further progress ...
Hoebe R A - - 2007
Fluorescence microscopy of living cells enables visualization of the dynamics and interactions of intracellular molecules. However, fluorescence live-cell imaging is limited by photobleaching and phototoxicity induced by the excitation light. Here we describe controlled light-exposure microscopy (CLEM), a simple imaging approach that reduces photobleaching and phototoxicity two- to tenfold, depending ...
Salazar Georgina To'a - - 2007
The selection and collection of single cells from within a heterogeneous population is required to produce genetically engineered cell lines, to develop new stem cell lines, and for single-cell studies. We describe a new platform for the positive selection of single live mammalian cells while the cells remain adherent to ...
Martin Robert M - - 2007
In the recent molecular and cell biological research, there is an increasing need for labeling of subcellular structures in living cells. Here, we present the use of a fluorescently labeled cell penetrating peptide for fast labeling of nucleoli in living cells of different species and origin. We show that the ...
Greulich Karl Otto - - 2007
This contribution bridges the gap from early European contributions via laser micromanipulation to recent work on the use of laser microbeams and optical tweezers in studies of basic aspects of heart infarction. Laser transfection, particularly of plant cells and their chloroplasts, and laser microdissection of chromosomes with subsequent generation of ...
Colombelli Julien - - 2007
Dynamic microscopy of living cells and organisms alone does not reveal the high level of complexity of cellular and subcellular organization. All observable processes rely on the activity of biochemical and biophysical processes and many occur at a physiological equilibrium. Experimentally, it is not trivial to apply a perturbation that ...
Levi Valeria - - 2007
In the last years, significant advances in microscopy techniques and the introduction of a novel technology to label living cells with genetically encoded fluorescent proteins revolutionized the field of Cell Biology. Our understanding on cell dynamics built from snapshots on fixed specimens has evolved thanks to our actual capability to ...
Allen Lee-Ann H - - 2007
Neutrophils are short-lived granulocytes essential for innate host defense. We describe here methods for analysis of resting and activated cells using immunofluorescence and confocal microscopy. Procedures for stimulation of adherent and suspended cells are provided along with protocols for particle opsonization and synchronized phagocytosis. Most importantly, we describe in detail ...
Berns Michael W - - 2007
This chapter briefly review the four major methods of optical trapping: (1) directly on to single cells or groups of cells, (2) directly on to organelles and structures inside of the cell, (3) on to a bead as a "handle" to apply force, and (4) on to a bead that ...
Desai Ravi - - 2007
In this video, we will present our approach to measure cellular traction forces using a microfabricated array of posts. Traction forces are generated through myosin-actin interactions and play an important role in our physiology. During development, they enable cells to move from one location to the next in order to ...
Radmacher Manfred - - 2007
The mechanical properties of cells are important for many cellular processes like cell migration, cell protrusion, cell division, and cell morphology. Depending on cell type, the mechanical properties of cells are determined mainly by the cell wall or the interior cytoskeleton. In eukaryotic cells, the stiffness is mainly determined by ...
Schulte Albert - - 2007
Needle-type voltammetric ultramicroelectrodes show exceptional sensitivity for the detection of redox-active substances, rapid response times, and total tip diameters in the lower micrometer range. These characteristics make them ideal for analyzing the chemical environment and the activity of isolated living cells, which in their various forms are the microscopic building ...
Hoffman Robert M - - 2007
Dual-color fluorescent cells, with one color in the nucleus and the other in the cytoplasm, enable real-time nuclear-cytoplasmic dynamics to be visualized in living cells in vivo as well as in vitro. To obtain the dual-color cells, red fluorescent protein (RFP) is expressed in the cytoplasm of cancer cells, and ...
Hill Andrew A - - 2007
BACKGROUND: High content screening (HCS) is a powerful method for the exploration of cellular signalling and morphology that is rapidly being adopted in cancer research. HCS uses automated microscopy to collect images of cultured cells. The images are subjected to segmentation algorithms to identify cellular structures and quantitate their morphology, ...
Ansari Aseem Z - - 2007
As cellular machines and processes that regulate the flow of genomic information have come into sharper focus, a new level of chemical control has become possible. The scope of such chemical intervention extends from the mechanistic dissection of biochemical processes in living cells to the targeted control of gene networks ...
Chen Qian - - 2007
Image processing techniques are bringing new insights to biomedical research. The automatic recognition and classification of biomedical objects can enhance work efficiency while identifying new inter-relationships among biological features. In this work, a simple rule-based decision tree classifier is developed to classify typical features of mixed cell types investigated by ...
Chown Matthew G - - 2007
The structure, physiology, and fate of living cells are all highly sensitive to mechanical forces in the cellular microenvironment, including stresses and strains that originate from encounters with the extracellular matrix (ECM), blood and other flowing materials, and neighbouring cells. This relationship between context and physiology bears tremendous implications for ...
Stone John W JW Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, - - 2007
In biological tissue, complex mechanisms of cellular response are closely linked to the mechanical environment that cells experience. The key to understanding these mechanisms may lie in measurement of local mechanical fields near living cells and between cells. We have developed a novel optical measurement technique which combines the light ...
Panorchan Porntula - - 2007
We describe a new method to measure the local and global micromechanical properties of the cytoplasm of single living cells in their physiological milieu and subjected to external stimuli. By tracking spontaneous, Brownian movements of individual nanoparticles of diameter>or=100 nm distributed within the cell with high spatial and temporal resolutions, ...
Lele Tanmay P - - 2007
Analysis of how cells sense and respond to mechanical stress has been limited by the availability of techniques that can apply controlled mechanical forces to living cells while simultaneously measuring changes in cell and molecular distortion, as well as alterations of intracellular biochemistry. We have confronted this challenge by developing ...
Ares Isabel R - - 2007
BACKGROUND: Pectenotoxins are a group of natural products from marine origin that can accumulate in shellfish and intoxicate humans. Recently, novel homologues such as pectenotoxin-11 (PTX-11) and pectenotoxin-2 seco acid (PTX-2SA) have been identified. Their toxic potential towards experimental animals has been evaluated however their interaction with cellular systems is ...
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