Search Results
Results 251 - 300 of 1260
< 1 2 3 4 5 6 7 8 9 10 11 >
Johnsson Kai - - 2009
Autofluorescent proteins have become indispensable in our quest to visualize molecular events in living cells. Further progress in the visualization and quantification of all biochemical activities of the cell will require the introduction of additional and complementary methods for sensing and probing biomolecules. Here I highlight some of the areas ...
Chan James W - - 2009
Laser tweezers Raman spectroscopy (LTRS) was used to characterize the effect of different chemical fixation procedures on the Raman spectra of normal and leukemia cells. Individual unfixed, paraformaldehyde-fixed, and methanol-fixed normal and transformed lymphocytes from three different cell lines were analyzed with LTRS. When compared to the spectra of unfixed ...
Chen Xu-Wei - - 2009
Live HeLa cells immobilized on Sephadex G-50 beads were used as a medium for the preconcentration and speciation of inorganic arsenic. The sorption of arsenic species by live HeLa cells involves both surface uptake and bioaccumulation within the cells. At pH 3.0, the cells accumulate arsenate with high specificity over ...
Jha Sandeep Kumar - - 2009
The lyophilized biomass of bacterium Brevibacterium ammoniagenes was immobilized in polystyrene sulphonate-polyaniline (PSS-PANI) conducting polymer on a Pt twin wire electrode by potentiostatic electropolymerization. The bacterial cells retained their viability as well as urease activity under entrapped state, as confirmed with bacterial live-dead fluorescent assay and enzymatic assays. The entrapped ...
Velásquez Lina - - 2009
The tolerance to As, Hg, Co, Fe and Cr was determined in different Colombian Bacillus sphaericus native strains, as well as the biosorption and bioaccumulation in living biomass. In addition, biosorption of Cr in dead cells was also determined. Living cells of the two most tolerant strains had the capacity ...
Pan Wenliang - - 2009
Two-photon excitation (TPE) fluorescence lifetime imaging microscopy (FLIM) and emission spectral imaging (ESI) are powerful tools for fluorescence resonance energy transfer (FRET) measurement. In this study, we use these two techniques to analyze caspase-3 activation inside single living cells during anticancer drug-induced human lung adenocarcinoma (ASTC-a-1) cell death. TPE-ESI of ...
Hodneland Erlend - - 2009
This work presents a unified framework for whole cell segmentation of surface stained living cells from 3-D data sets of fluorescent images. Every step of the process is described, image acquisition, prefiltering, ridge enhancement, cell segmentation, and a segmentation evaluation. The segmentation results from two different automated approaches for segmentation ...
Hoppe Adam D AD Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD 57007-0896, USA. - - 2009
Advances in microscopy and fluorescent probes provide new insight into the nanometer-scale biochemistry governing the interactions between eukaryotic cells and pathogens. When combined with mathematical modelling, these new technologies hold the promise of qualitative, quantitative and predictive descriptions of these pathways. Using the light microscope to study the spatial and ...
Schmitz Michael H A - - 2009
Fluorescence live microscopy is a powerful technique to study complex cellular dynamics such as cell division. The availability of fluorescent markers based on GFP fusion proteins for virtually any cellular structure allows efficient visualization of specific processes, and the combination of different fluorophores can be used to study their coordination. ...
Müller Werner E G - - 2009
Lake Baikal is rich in endemic sponge species, among them the arborescently growing species Lubomirskia baicalensis. During winter when the lake is covered by ice, this species reproduces sexually, reflecting a high metabolic activity. Throughout the year, L. baicalensis lives in association with dinoflagellates, which - according to the data ...
Asakawa Haruhiko - - 2009
The fission yeast Schizosaccharomyces pombe has provided a useful experimental system to study nuclear structures during meiosis. Unlike many higher animals in which meiosis takes place only in specialized tissues deep inside their bodies, S. pombe is a unicellular eukaryote and its meiosis can be induced simply by depleting nitrogen ...
Martínez-Osorio Hernán - - 2009
PURPOSE: To characterize conjunctival cells obtained by brush cytology (BC) and establish short-term cultures. METHODS: Human tarsal and bulbar conjunctival cells were obtained by BC and transported in 3 different media: serum-free medium (DK-SFM) with low [Ca(2+)], 10% fetal bovine serum (FBS) supplemented medium (FBSm10), and 20% FBS-supplemented medium (FBSm20). ...
Mosig Axel - - 2009
BACKGROUND: With the increasing availability of live cell imaging technology, tracking cells and other moving objects in live cell videos has become a major challenge for bioimage informatics. An inherent problem for most cell tracking algorithms is over- or under-segmentation of cells - many algorithms tend to recognize one cell ...
Happel Patrick - - 2009
Scanning ion conductance microscopy (SICM) is a suitable tool for imaging surfaces of living cells in a contact-free manner. We have shown previously that SICM in backstep mode allows one to trace the outlines of entire cell somata and to detect changes in cellular shape and volume. Here we report ...
Wirtz Denis - - 2009
A multitude of cellular and subcellular processes depend critically on the mechanical deformability of the cytoplasm. We have recently introduced the method of particle-tracking microrheology, which measures the viscoelastic properties of the cytoplasm locally and with high spatiotemporal resolution. Here we establish the basic principles of particle-tracking microrheology, describing the ...
Nikolaev Viacheslav O - - 2009
Recent developments of biophysical and electrophysiological techniques have enabled researchers to monitor levels of free intracellular cGMP in real-time and in intact living cells. These techniques are based on the use of cGMP sensors, which respond to cGMP with changes in transmembrane ion current or changes in fluorescence. Here, we ...
Fitzpatrick James A J - - 2009
We demonstrate the effectiveness of a genetically encoded Malachite Green (MG) binding fluorogen activating protein (FAP) for live cell stimulated emission depletion nanoscopy (STED). Both extracellular and intracellular FAPs were tested in living cells using fluorogens with either membrane expressed FAP or as an intracellular FAP-actin fusion. Structures with FWHM ...
Miyanaga Yukihiro - - 2009
In this chapter, we describe methods to monitor signaling events at the single-molecule level on the membrane of living cells by using total internal reflection fluorescence microscopy (TIRFM). The techniques provide a powerful tool for elucidating the stochastic properties of signaling molecules involved in chemotaxis of the cellular slime mold ...
Cerchia Laura - - 2009
Many signalling proteins involved in diverse functions such as cell growth and differentiation can act as oncogenes and cause cellular transformation. These molecules represent attractive targets for cancer diagnosis or therapy and therefore are subject to intensive investigation. Aptamers are small, highly structured nucleic acid molecules, isolated from combinatorial libraries ...
Pereira António J - - 2009
Progress from our present understanding of the mechanisms behind mitosis has been compromised by the fact that model systems that were ideal for molecular and genetic studies (such as yeasts, C. elegans, or Drosophila) were not suitable for intracellular micromanipulation. Unfortunately, those systems that were appropriate for micromanipulation (such as ...
Aoki Kazuhiro - - 2009
Small GTPases act as molecular switches that regulate a variety of cellular functions, such as proliferation, cell movement and vesicle trafficking. Genetically encoded biosensors based on the principle of fluorescence resonance energy transfer (FRET) can visualize a spatio-temporal activity of small GTPases in living cells, thereby helping us to understand ...
Cafferty Patrick - - 2009
Glial cells of both vertebrate and invertebrate organisms must migrate to final target regions in order to ensheath and support associated neurons. While recent progress has been made to describe the live migration of glial cells in the developing pupal wing (1), studies of Drosophila glial cell migration have typically ...
Peterson Alexander W - - 2009
A critical challenge in cell biology is quantifying the interactions of cells with their extracellular matrix (ECM) environment and the active remodeling by cells of their ECM. Fluorescence microscopy is a commonly employed technique for examining cell-matrix interactions. A label-free imaging method would provide an alternative that would eliminate the ...
Kurakin Alexei - - 2009
The present work is intended to demonstrate that most of the paradoxes, controversies, and contradictions accumulated in molecular and cell biology over many years of research can be readily resolved if the cell and living systems in general are re-interpreted within an alternative paradigm of biological organization that is based ...
Yang Lingzhi - - 2009
Cryopreserved cells stored in dry ice or liquid nitrogen is the classical method for transporting cells between research laboratories in different cities around the world in order to maintain cell viability. An alternative method is to ship the live cells in flasks filled with cell culture medium. Both methods have ...
Lee Luke P LP Department of Bioengineering, University of California, Berkeley, CA 94720, USA. - - 2009
This paper presents satellite nanoscopes and biological application specific integrated circuits (BioASICs). Satellite nanoscope is developed for spectroscopic imaging of living cells, molecular optogenetics (i.e. the remote control of gene regulation and protein expression), and therapeutic applications. Fundamental understanding of living cells via satellite nanoscopes will provide insights of molecular ...
Backman Vadim V Northwestern University, Evanston, IL 60208, USA. - - 2009
Understanding cell functioning at the nanoscale has been hampered in part by the diffraction limited resolution of optical microscopy. We developed partial wave spectroscopic (PWS) microscopy that is capable of quantifying statistical properties of cell structure at the nanoscale. Our animal and human studies demonstrated that alterations in the nanoscale ...
Yarmush Martin L ML Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital, Harvard Medical School, Massachusetts 02139, USA. - - 2009
Living cells are remarkably complex. To unravel this complexity, living-cell assays have been developed that allow delivery of experimental stimuli and measurement of the resulting cellular responses. High-throughput adaptations of these assays, known as living-cell microarrays, which are based on microtiter plates, high-density spotting, microfabrication, and microfluidics technologies, are being ...
Lu Nan N Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, - - 2009
Apoptosis is a genetically controlled process of cell suicide that plays an important role in animal development and in maintaining homeostasis. The nematode Caenorhabditis elegans has proven to be an excellent model organism for studying the mechanisms controlling apoptosis and the subsequent clearance of apoptotic cells, aided with cell-biological and ...
Daum John R JR Oklahoma Medical Research Foundation, Oklahoma City, OK, - - 2009
Here, we describe methods to prepare a mammalian expression plasmid encoding EGFP fused to the amino-terminus of human DNA topoisomerase IIalpha (Topo IIalpha) for use in studying the dynamics of Topo IIalpha in living cells. In previous studies, this plasmid was transfected into LLC-Pk cells, a porcine epithelial cell line ...
Kim I I Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, USA. - - 2009
Experiments using live dissociated carotid body (CB) cells for patch clamping, [Ca(++)](i) or other measurements require positive identification of the cell being recorded. At present, cell morphology is usually employed, but several cell types within the carotid body evidence similar morphologic characteristics. Therefore, we sought to develop a method utilizing ...
Wu Dong-Mei - - 2009
A novel experimental method was developed to study the origin of the voltammetric response of human prostate cancer (PC-3) cell suspension as a model in consideration of the biological characters of living cells. The presence of guanine and xanthine in the cell eluent secreted by the living cells was verified ...
Cheng Wen-Yao - - 2009
Live-cell imaging chambers are used in a wide range of cell biology research. Recently, chambers capable of taking high-resolution and time-lapse images of live cells have been developed and become commercially available. However, because most of these chambers are designed to maintain a thermally stable environment for the cells under ...
Aida, Masato
Beard worms (Siboglinidae, Polychaeta), which lack a mouth and a digestive tract, harbor thioautotrophic or methanotrophic bacteria in special cells called bacteriocytes. These endosymbionts have been considered to be trapped at a specific larval stage from the environment. Although many species of beard worms have been discovered in various abyssal ...
Scaffidi Jonathan P JP Department of Biomedical Engineering, Duke University, 136 Hudson Hall, P. O. Box 90281, Durham, NC 27708, - - 2009
In this paper, we describe the development and application of a pH-sensitive plasmonics-active fiber-optic nanoprobe suitable for intracellular bioanalysis in single living human cells using surface-enhanced Raman scattering (SERS) detection. The effectiveness and usefulness of SERS-based fiber-optic nanoprobes are illustrated by measurements of intracellular pH in HMEC-15/hTERT immortalized "normal" human ...
Moya Andrés - - 2009
Recent technical and conceptual advances in the biological sciences opened the possibility of the construction of newly designed cells. In this paper we review the state of the art of cell engineering in the context of genome research, paying particular attention to what we can learn on naturally reduced genomes ...
Draux Florence - - 2009
Raman microspectroscopy allows probing subcellular compartments and provides a unique spectral fingerprint indicative of endogenous molecular composition. Although several spectroscopic cell studies have been reported on fixed samples, only few attempts concern single growing cells. Here, we have tested different optical substrates that would best preserve cell integrity and allow ...
Hirano Yu - - 2008
Antifreeze proteins (AFPs) can protect cells from hypothermic damage; however, their mechanism of action remains unclear. Scanning electrochemical microscopy (SECM) can evaluate the size and activities of cells, although long-term continuous monitoring has been unsuccessful. We constructed a novel, fully automated, time-lapse SECM system and investigated the cell preservation effect ...
Hleb Ekaterina Y - - 2008
AIMS: We propose and have experimentally studied a new method with improved sensitivity and specificity of imaging of living cells. METHOD: Intracellular photothermal bubbles generated around gold nanoparticles (NPs) and their clusters were proposed as optical scattering probes for the amplification of scattered light. RESULTS: Microbubbles generated around gold spheres ...
Mizuno Hajime - - 2008
The molecular content from the cytoplasm of a live, single mammalian cell and its organelle were trapped with a nano-electrospray ionization (ESI) tip acting as a micropipette under a video microscope, and hundreds of small molecular peaks were detected by direct nano-ESI mass spectrometry (MS). Granule- or cytoplasm-specific peaks in ...
Gantenbein-Ritter Benjamin - - 2008
Several different assays are commonly used to evaluate survival of cells inside tissues or three-dimensional carriers, but their accuracy and reliability have not been evaluated. Here, we compare three methods for cell viability (CV) determination: (i) lactate dehydrogenase (LDH) staining on cryosections, (ii) calcein AM/ethidium homodimer-1 (CaAM/EthH) staining, and (iii) ...
Gratzl Miklós - - 2008
Direct delivery of molecules into the cytosol of live cells is required in many areas of biology and clinical research. Molecules of interest include indicator dyes, biomolecules, and pharmacological agents. In this work we describe continuous delivery of molecules into single cells using a diffusional microburet, DMB. The DMB is ...
Ter-Avetisyan Gohar - - 2009
Arginine-rich peptides are a subclass of cell-penetrating peptides that are taken up by living cells and can be detected freely diffusing inside the cytoplasm and nucleoplasm. This phenomenon has been attributed to either an endocytic mode of uptake and a subsequent release from vesicles or to direct membrane penetration (transduction). ...
Gorelik Julia J National Heart and Lung Institute, Imperial College London, London, United Kingdom. - - 2008
The most valuable property of stem cells (SCs) is their potential to differentiate into many or all cell types of the body. So far, monitoring SC differentiation has only been possible after cells were fixed or destroyed during sample preparation. It is, however, important to develop nondestructive methods of monitoring ...
Cohen A A - - 2008
Why do seemingly identical cells respond differently to a drug? To address this, we studied the dynamics and variability of the protein response of human cancer cells to a chemotherapy drug, camptothecin. We present a dynamic-proteomics approach that measures the levels and locations of nearly 1000 different endogenously tagged proteins ...
Snook Richard D - - 2009
In this review the recent emergence of Raman tweezers as an analytical technique for single eukaryotic cell analysis is described. The Raman tweezer technique combines Raman spectroscopy as a diagnostic tool with optical tweezers by which means single cells can be trapped and manipulated in a laser beam using a ...
Terrovitis John - - 2008
OBJECTIVES: We examined the sodium-iodide symporter (NIS), which promotes in vivo cellular uptake of technetium 99m ((99m)Tc) or iodine 124 ((124)I), as a reporter gene for cell tracking by single-photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging. BACKGROUND: Stem cells offer the promise of cardiac repair. Stem ...
Kim Jin Seob JS Department of Mechanical Engineering, the Johns Hopkins University, Baltimore, MD 21218, - - 2009
Mechanical properties of the living cell are important in cell movement, cell division, cancer development and cell signaling. There is considerable interest in measuring local mechanical properties of living materials and the living cytoskeleton using micromechanical techniques. However, living materials are constantly undergoing internal dynamics such as growth and remodeling. ...
Hirano Yu - - 2008
Antifreeze proteins (AFPs) can protect cells from hypothermic damage; however, their mechanism of action remains unclear. Scanning electrochemical microscopy (SECM) can evaluate the size and activities of cells, although long-term continuous monitoring has been unsuccessful. We constructed a novel, fully automated, time-lapse SECM system and investigated the cell preservation effect ...
Chen Ying Y Department of Electrical, Computer, and System Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, - - 2009
This paper presents automated methods to quantify dynamic phenomena such as cell-cell interactions and cell migration patterns from time-lapse series of multi-channel three-dimensional image stacks of living specimens. Various 5-dimensional (x, y, z, t, lambda) images containing dendritic cells (DC), and T-cells or thymocytes in the developing mouse thymic cortex ...
< 1 2 3 4 5 6 7 8 9 10 11 >