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This page shows you the most recent publications within this specialty of the MedWorm directory. This is page number 32.

Transplantation of Human Embryonic Stem Cells and Derivatives to the Chick Embryo
Traditional methods of studying the differentiation of human embryonic stem cells (hESCs) include generation of embryoid bodies, induced differentiation in vitro, and transplantation to immune-deficient mice. The chick embryo is a well-studied and accessible experimental system that has been used for many years as a xenograft host for mammalian cells. Several years ago, we performed experiments transplanting colonies of hESC into organogenesis-stage chick embryos to establish a novel system for studying the developmental programs and decisions of pluripotent human cells. Fluorescent hESC were used, in order to permit ident...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

Human Embryo Culture and Assessment for the Derivation of Embryonic Stem Cells (ESC)
The culture and critical assessment of early human embryos during the first week of human development are reviewed for the derivation of ESC. Both normal and abnormal features are assessed by phase contrast microscopy of whole embryos and in serial sections of fixed material by light and electron microscopy (TEM). Normal embryos follow a time table of development and have equal blastomeres with minimal fragmentation and nuclear defects. Abnormal embryos show more fragmentation and nuclear aberrations such as micronucleation and multinucleation, reflected by aneuploidy, polyploidy, and mosaicism. The selection of normal emb...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

Differentiation of Neural Precursors and Dopaminergic Neurons from Human Embryonic Stem Cells
We describe here a reproducible, chemically defined protocol that allows directed differentiation of hESCs to nearly pure neuroectodermal cells and neurons. First, hESC colonies are detached from mouse fibroblast feeder layers and form aggregates to initiate the differentiation procedure. Second, after 4 days of suspension culture, the ESC growth medium is replaced with neural induction medium to guide neuroectodermal specification. Third, the differentiating hESC aggregates are attached onto the culture surface at day 6–7, where columnar neural epithelial cells appear and organize into rosettes. Fourth, the neural r...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

Vascular Differentiation of Human Embryonic Stem Cells in Bioactive Hydrogel-Based Scaffolds
The vascularization of tissue constructs remains a major challenge in regenerative medicine, as the diffusional supply of oxygen can support only 100–200 μm thick layers of viable tissue. The formation of a mature and functional vascular network requires communication between endothelial cells (ECs) and smooth muscle cells (SMCs). Potential sources of these cells that involve noninvasive methodologies are required for numerous applications including tissue-engineered vascular grafts, myocardial ischemia, wound healing, plastic surgery, and general tissue-engineering applications. Human embryonic stem cells (h...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

In Vitro Derivation of Chondrogenic Cells from Human Embryonic Stem Cells
Human embryonic stem cells (hESCs) have the ability to self-renew and differentiate into any cell lineage of the three germ layers, therefore holding great promise for regenerative medicine applications. However, directing lineage-restricted differentiation of hESCs and obtaining a homogenous differentiated cell population is still a challenge. We previously described a micromass culture system as a model system to study chondrogenic commitment of the hESCs. Using this system, various growth factors including BMP2 and TGFβ1 direct chondrogenic differentiation and modulate cartilage-specific matrix gene expression in a...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

Embryonic Stem Cells as a Model for Studying Melanocyte Development
Melanocytes are neural crest-derived pigment-producing cells that reside in the inner ear, in the uveal tract, in hair follicles, and in the skin. The main function of melanocytes is to provide pigmentation through melanin production and secretion to the immediate surrounding area. Although much is known about mature melanocyte function and regulation, particularly in the skin, little is known with regard to the signals and gene expression patterns that ensue upon melanocyte development and differentiation from embryonic precursors. The ability to examine these patterns in an in vitro specified setting through the use of e...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

Generation of Neural Crest Cells and Peripheral Sensory Neurons from Human Embryonic Stem Cells
Peripheral somatic sensory neurons (PSNs) are responsible for the critical function of transmitting multiple modalities of information from the outside world, including heat, touch, and pain, as well as the position of muscles required for coordinated voluntary movement to the central nervous system. Many peripheral neuropathies exist, including hereditary neurodegeneration in Familial Dysautonomia, infections of PSNs by viruses such as Varicella zoster and damage to PSNs and/or their process resulting from other disease conditions such as diabetes. Understanding of the etiology of these diseases and development of treatme...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

Human Embryonic Stem Cell Differentiation on Periodontal Ligament Fibroblasts
Human embryonic stem cells' (hESCs) unlimited proliferative potential and differentiation capability to all somatic cell types made them potential cell source in different cell-based tissue engineering strategies as well as various experimental applications in fields such as developmental biology, pharmacokinetics, toxicology, and genetics. Periodontal tissue engineering aims to improve the outcome of regenerative therapies which have variable success rates when contemporary techniques are used. Cell-based therapies may offer potential advantage in overcoming the inherent limitations associated with guided tissue-regenerat...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

hESC Engineering by Integrase-Mediated Chromosomal Targeting
Bacteriophage recombinases can target specific loci in human embryonic stem cells (hESCs) at high efficiency allowing for long-term expression of transgenes. In this chapter, we describe a retargeting system where phiC31 integrase is used to deliver a chromosomal target for a second integrase, R4. The engineered hESC line can be adapted for complex element assembly using Multisite Gateway technology. Retargeted clones show sustained expression and appropriate regulation of the transgenes over long-term culture and upon differentiation. The system described here represents a method to rapidly assemble complex plasmid-based ...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

Study of Gap Junctions in Human Embryonic Stem Cells
Gap junctional intercellular communication (GJIC) has been described in different cell types including stem cells and has been involved in different biological events. GJIC is required for mouse embryonic stem cell maintenance and proliferation, and various studies suggest that functional GJIC is a common characteristic of human embryonic stem cells (hESC) maintained in different culture conditions. This chapter introduces methods to study gap junctions in hESC, from expression of gap junction proteins to functional study of GJIC in hESC proliferation, apoptosis, colony growth, and pluripotency.
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

Immunoflourescence and mRNA Analysis of Human Embryonic Stem Cells (hESCs) Grown Under Feeder-Free Conditions
This chapter describes the procedures in order to do immunofluorescence (IF) microscopy and quantitative PCR (qPCR) analysis of human embryonic stem cells (hESCs) grown specifically under feeder-free conditions. A detailed protocol outlining the steps from initially growing the cells, passaging onto 16-well glass chambers, and continuing with the general IF and qPCR steps will be provided. The techniques will be illustrated with new results on cellular localization of transcriptional factors and components of the Hedgehog, Wnt, and PDGF signaling pathways to primary cilia in stem cell maintenance and differentiation. Furth...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

A Two- and Three-Dimensional Approach for Visualizing Human Embryonic Stem Cell Differentiation
We describe a technique allowing paraffin embedding an entire hESC colony (e.g., ˜ 150 µm thick) and prepare 2-µm thick serial sections. Different staining procedures applied to individual sections produce a 2D survey of the developing hESC colony. Furthermore, a new and useful visualization of this 2D-expression pattern can be created by developing a 3D-model of the culture, based on serial paraffin sections. Individual sections are stained using individual markers. Using 3D image processing software such as Mimics or 3D-Doctor, the actual 3D-rendering of an entire colony can be accomplished. An extended...
Source: Springer protocols feed by Cell Biology - October 12, 2009 Category: Cytology Source Type: news

AUA MA 2009 - Diagnostic accuracy of urinary cytology for upper-tract urothelial carcinoma ...
This study assessed the diagnostic accuracy of urine cytology alone in the management of upper...
Source: UroToday - October 12, 2009 Category: Urology & Nephrology Tags: Browse Categories - Bladder Cancer Source Type: news

Mechanism That Helps Bacteria Avoid Destruction In Cells Identified
Infectious diseases currently cause about one-third of all human deaths worldwide, more than all forms of cancer combined. Advances in cell biology and microbial genetics have greatly enhanced understanding of the cause and mechanisms of infectious diseases. Researchers have now found a way in which intracellular pathogens exploit the biological attributes of their hosts in order to escape destruction.
Source: ScienceDaily Headlines - October 12, 2009 Category: Science Source Type: news

Biopsy and LLETZ increase after effects after colposcopy
Women who have cervical punch biopsies and large loop excision of the transformation zone during colposcopy for low-grade cytology experience a high rate of after-effects, conclude investigators.
Source: MedWire News - Ob/Gyn - October 11, 2009 Category: OBGYN Source Type: news

Urine cytology
— Overview covers definition, results of this urinary tract and bladder cancer test. Sponsored by:Chemotherapy.com - http://www.chemotherapy.com
Source: MayoClinic.com Full Feed - October 10, 2009 Category: Consumer Health News Source Type: news

Vitamin D prevents breast cancer
This study suggests women sunbathe with breast tissue exposed to the sun to enhance local vitamin D production. The provision of 400 IU of vitamin D per day has been found to reduce the risk of pancreatic cancer by 43%. - You Don't Have to be Afraid of Cancer Anymore by Bill SardiTaken together, these facts suggest that vitamin D and its derivatives may play a role in regulating the expression of genes and protein products that prevent and inhibit breast cancer. The cancer-stopping power of vitamin D has been documented in osteosarcoma (bone cancer), melanoma, colon cancer, and breast cancer. These cancer cells contain vit...
Source: NaturalNews.com - October 9, 2009 Category: Consumer Health Advice Source Type: news

Researchers identify mechanism that helps bacteria avoid destruction in cells
(Thomas Jefferson University) Infectious diseases currently cause about one-third of all human deaths worldwide, more than all forms of cancer combined. Advances in cell biology and microbial genetics have greatly enhanced understanding of the cause and mechanisms of infectious diseases. Researchers from Thomas Jefferson University, the Pasteur Institute in Paris, and Yale University reported in PLoS ONE, a way in which intracellular pathogens exploit the biological attributes of their hosts in order to escape destruction.
Source: EurekAlert! - Medicine and Health - October 9, 2009 Category: Global & Universal Source Type: news

Review of Murine Dendritic Cells: Types, Location, and Development
Dendritic cells (DCs) are key coordinators of the immune response, governing the choice between tolerance and immunity. DCs are professional antigen-presenting cells capable of presenting antigen on MHC molecules and priming CD4 and CD8 T-cell responses. They form a heterogeneous group of cells based on phenotype, location, and function. In this review, murine DCs will be discussed regarding their function with special emphasis on their tissue distribution. Recent findings on DC homeostasis during cancer progression will be presented. Finally, the developmental pathways leading to DC differentiation from their precursors will be summarized.
Source: Springer protocols feed by Cell Biology - October 8, 2009 Category: Cytology Source Type: news

Review of Human DC Subtypes
Dendritic cells (DC) are critical to the induction and regulation of the innate and adaptive immune responses. They have been implicated in the pathogenesis of many autoimmune and chronic inflammatory diseases as well as contributing to the development of tumours by their lack of appropriate function. As such, understanding human DC biology provides the insight needed to develop applications for their use in the treatment of diseases. Currently, studies on mouse DC outnumber those on human cells; however, the comparison between mouse and human models has been somewhat misleading due to the basic biological and practical di...
Source: Springer protocols feed by Cell Biology - October 8, 2009 Category: Cytology Source Type: news

Liver cells grown from patients' skin cells
(Medical College of Wisconsin) Scientists at the Medical College of Wisconsin in Milwaukee have successfully produced liver cells from patients' skin cells opening the possibility of treating a wide range of diseases that affect liver function. The study was led by Stephen A. Duncan, D. Phil., Marcus Professor in Human and Molecular Genetics, and professor of cell biology, neurobiology and anatomy, , along with postdoctoral fellow Karim Si-Tayeb, Ph.D., and graduate student Ms. Fallon Noto.
Source: EurekAlert! - Biology - October 8, 2009 Category: Biology Source Type: news

NHLBI supports consortium exploring stem-cell-based tools and treatments
(Massachusetts General Hospital) Two teams led by Massachusetts General Hospital researchers, also members of the Harvard Stem Cell Institute, are among 18 groups receiving National Heart Lung and Blood Institute grants for the development of stem-cell based tools and treatments to understand and treat cardiovascular and blood disorders. The Progenitor Cell Biology Consortium will consist of nine research hubs, each involving multidiscplinary teams from two academic medical centers.
Source: EurekAlert! - Medicine and Health - October 8, 2009 Category: Global & Universal Source Type: news

Scanning for Transcription Factor Binding by a Variant EMSA
We describe here our use and refinement of a variant EMSA that can employ multiple and relatively long (up to 1000 bp) probes of promoter sequence in one binding reaction for interaction with nuclear proteins in general and individual transcription factors in particular. We provide labeling and electrophoresis methods suitable for such probes and also highlight the mobility shift differences one can expect with the variant probe method.
Source: Springer protocols feed by Cell Biology - October 6, 2009 Category: Cytology Source Type: news

RNA Interference in Keratinocytes and an Organotypic Model of Human Epidermis
Gene silencing approaches afford investigators the ability to gain important insight into the normal functional requirements of specific epidermal proteins and promise to yield a powerful therapeutic means to dampen the level of proteins that are mutated or frequently overexpressed in skin disease. The efficient and tractable delivery of siRNAs into epidermal keratinocytes is seminal to this process. Here, we describe techniques for transient and long-term silencing of a representative gene product, namely desmoglein 1, in primary human epidermal keratinocytes maintained as submerged cultures or three-dimensional organotyp...
Source: Springer protocols feed by Cell Biology - October 6, 2009 Category: Cytology Source Type: news

3 Americans Share Nobel for Medicine
Three scientists solved a longstanding puzzle of cell biology with deep relevance to cancer and aging.
Source: NYT > Health - October 6, 2009 Category: Consumer Health News Authors: By NICHOLAS WADE Tags: Genetics and Heredity Nobel Prizes Science and Technology Medicine and Health Awards, Decorations and Honors Blackburn, Elizabeth H Source Type: news

BLyS Ligands and Receptors
series: Contemporary Immunology The BLyS/BAFF family of cytokines and receptors has captured and held the attention of B cell biologists during the last decade. Discovery of the two ligands and three receptors comprising this family has yielded a watershed of insights; fostering fresh paradigms in our views about the differentiation, selection, and homeostatic control of virtually all B cell subsets. Moreover, ...
Source: Springer Biomedical Sciences titles - October 5, 2009 Category: Biomedical Science Tags: Immunology Source Type: news

Key to a long life found (again)
The Daily Express claims that a “wonder pill can lengthen your life by 25 years” and that researchers have found the key to the “elixir of life”. Although the article contains bold claims and a picture of a woman taking a pill, no such pill exists. The research behind this story investigated how a naturally occurring compound called spermidine affected the age-related processes and longevity of yeast, flies, worms, human blood cells and mice. The laboratory-based study found that spermidine protected cells from certain processes related to ageing and cell damage, increasing the lifespan of the flies, blood cel...
Source: NHS News Feed - October 5, 2009 Category: Consumer Health News Source Type: news

Would-be neurosurgeon gets look at brain research
A suburban Detroit high school student has a head start in her quest to be a brain surgeon, with help from a cell biologist at Wayne State University's medical school. Since March, Gayathri (guy-AHTH'-ree) Kollipara has been shadowing assistant...
Source: OrlandoSentinel: Medical Research - October 3, 2009 Category: American Health Source Type: news

ASCB Wins NIH 'Stimulus Grant' To Build Virtual Library Of Cell Images For Researchers And Public
A $2.5 million "stimulus grant" announced yesterday by the National Institutes of Health (NIH) will enable the American Society for Cell Biology (ASCB) to build an unprecedented, online image library of the cell that will be readily accessible to researchers, educators, students, and the public, according to ASCB Executive Director Joan Goldberg.
Source: Health News from Medical News Today - October 3, 2009 Category: Consumer Health News Tags: IT / Internet / E-mail Source Type: news

F2-Isoprostanes: Sensitive Biomarkers of Oxidative Stress In Vitro and In Vivo: A Gas Chromatography-Mass Spectrometric Approach
A gas chromatography-mass spectrometric method was developed that allowed the accurate, highly sensitive and specific quantification of F2-isoprostanes (F2-IsoPs) in different tissues and body fluids. Measurement of F2-IsoPs in isolated rat brain mitochondria, HaCaT keratinocytes, human plasma, and microdialysates of human skin has established the occurrence of oxidative stress in a variety of model systems and disease states. F2-IsoPs correlated with other markers of lipid peroxidation (e.g., TBARS, HETEs) in experimental models of oxidative stress. F2-IsoPs were elevated about 100-fold after iron/ascorbate-induced oxidat...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Quantification of Lysophosphatidylcholine Species by High-Throughput Electrospray Ionization Tandem Mass Spectrometry (ESI-MS/MS)
Lysophosphatidylcholine (LPC) is a bioactive lipid implicated to play a functional role in various diseases including atherosclerosis, diabetes, cancer, and inflammation. Conventional methods are of limited value for a systematic evaluation of LPC species concentrations due to complicated, time-consuming procedures. Here we describe a methodology based on electrospray ionization tandem mass spectrometry (ESI-MS/MS) applicable for high-throughput LPC species quantification. This assay provides accuracy and precision sufficient for the analysis of large clinical studies as well as basic biochemical studies in a broad range o...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Volatile Oxylipins and Related Compounds Formed Under Stress in Plants
Plants form volatile oxylipins and related compounds under stress. Some of them are important flavor chemicals and give big impact on the flavor quality of food made from plant materials. They are also involved in defense responses of plants against pathogens and herbivores. Furthermore, in some instances, they cause harmful effects on plants themselves. Because of these significances of volatile oxylipins and related compounds, demands to perform comprehensive analyses of these compounds are increasing. In this chapter, we describe the simple but efficient procedures to reveal profiles of volatile oxylipins and related co...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Use of Lipidomics for Analyzing Glycerolipid and Cholesteryl Ester Oxidation by Gas Chromatography, HPLC, and On-line MS
Various analytical techniques have been adopted for the isolation and identification of the oxolipids and for determining their functionality. Gas chromatography in combination with mass spectrometry (MS) has been specifically utilized in analysis of isoprostanes and other low molecular weight oxolipids, although it requires derivatization of the solutes. In contrast, liquid chromatography (LC) in combination with on-line MS has proven to be well suited for analysis of intact oxolipids without (or minimal) derivatization. LC-MS has also been helpful for the identification of lipidomic changes resulting from covalent bindin...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Lipid Raft-Redox Signaling Platforms in Plasma Membrane
Membrane lipid rafts (LRs) have been demonstrated to be importantly involved in transmembrane signaling in a variety of mammalian cells. Many receptors can be aggregated within the LR clusters to form signaling platforms. Currently, LRs were reported to be clustered to aggregate, recruit, and assemble NADPH oxidase subunits and related proteins in various cells in response to various stimuli, forming redox signaling platforms. These LR signaling platforms may play important roles in the regulation of cellular activity and cell function, and also in the development of cell dysfunction or injury associated with various patho...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Mass Spectrometry Analysis of Polyisoprenoids Alcohols and Carotenoids via ESI(Li+)-MS/MS
Direct analysis of polyisoprenoid alcohols by electrospray ionization mass spectrometry (ESI-MS) often produces poor results requiring off-line time- and sample-consuming derivatization techniques. In this chapter, we describe a simple ESI-MS approach for the direct analysis of polyisoprenoid alcohols from biological samples. Lithium iodide is used to promote cationization by intense formation of [M+Li]+ adducts. Detection of polyisoprenoids with mass determination can thus be performed with high sensitivity (LOD near 100 pM), whereas characteristic collision-induced dissociations observed for both dolichols and polyprenol...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Detection of a Lipid-Lysine Adduct Family with an Amide Bond as the Linkage: Novel Markers for Lipid-Derived Protein Modifications
An amide-type adduct, hexanoyl-lysine (HEL) is generated from the reaction between n-6 fatty acid (FA)-derived lipid peroxide and lysine. Immunochemical and chemical methods can be used to detect the formation of HEL. For example, an ELISA kit using the monoclonal antibody to HEL is now commercially available. We recently identified propanoyl-lysine (propionyl-lysine, PRL) from the reaction of an n-3 FA and a lysine residue. The antibody to PRL has been prepared and characterized. Using these monoclonal antibodies, the localization of adducts in tissues has been confirmed. Moreover, both amide-type adducts, HEL and PRL, ca...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Mass-Spectrometric Characterization of Phospholipids and Their Hydroperoxide Derivatives In Vivo: Effects of Total Body Irradiation
We describe application of this methodology in assessments of phospholipid hydroperoxides using as an example their characterization and quantitative determinations in different tissues of mice exposed to total body irradiation (TBI, 10 and 15 Gy). Using ESI-MS, we identified individual molecular species – with particular emphasis on polyunsaturated molecules as preferred peroxidation substrates – in major classes of phospholipids: cardiolipin (CL), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), and phosphatidylinositol (PI) isolated from mouse brain, lung, muscles, small inte...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Assessing the Neuroprotective Effect of Antioxidative Food Factors by Application of Lipid-Derived Dopamine Modification Adducts
Advances in understanding the neurodegenerative pathologies are creating new opportunities for the development of neuroprotective therapies, such as antioxidant food factors, lifestyle modification, and drugs. However, the biomarker by which to determine the effect of the agent on neurodegeneration is limited. We here address hexanoyl dopamine (HED), one of novel dopamine adducts derived from brain polyunsaturated acid, referring to its in vitro formation, potent toxicity to SH-SY5Y cells, and application to assess the neuroprotective effect of antioxidative food factors. Dopamine is a neurotransmitter and its deficiency i...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Comprehensive mRNA Profiling of Lipid-Related Genes in Microglia and Macrophages Using Taqman Arrays
Quantitative real-time reverse-transcription (RT)-PCR is a precise and sensitive method to measure mRNA levels over a broad dynamic range. This chapter describes the quantitative transcript analysis of 41 selected lipid-related transcripts in macrophages and microglia using a novel “Lipidomic” Taqman Array. The Taqman Array results show that (1) stimulation with the liver-X-receptor and retinoid-X-receptor ligands T0901317 and 9-cis retinoic acid induces several genes of lipid metabolism, (2) lipopolysaccharide (LPS) and interferon-g (Ifn-g) strongly repress lipid-related genes, and (3) coincubation with docosa...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Monitoring Sterol Uptake, Acetylation, and Export in Yeast
Sterols are essential lipid components of eukaryotic membranes. They are synthesized in the endoplasmatic reticulum (ER) from where they are efficiently transported to the plasma membrane, which harbors ~90% of the free sterol pool of the cell. The molecular mechanisms that govern this lipid transport, however, are not well characterized and are challenging to analyze. Saccharomyces cerevisiae offers the opportunity to circumvent some of the technical limitations associated with studying this forward transport of sterols from the ER to the plasma membrane, because the organism can also take up sterols from the environment,...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Imaging Lipid Membrane Domains with Lipid-Specific Probes
Imaging membrane lipid domains to characterize their organization and function has been hindered by the lack of reliable lipid-specific probes. In this paper, we provide detailed methods to investigate, mainly by confocal microscopy, the distribution and dynamics of two components of the “lipid rafts,” sphingomyelin (SM) and cholesterol, using two specific lipid probes that have been extensively studied in the laboratory: lysenin, a SM-binding toxin and the fluorescent esters of poly(ethylene glycol) cholesteryl ether (PEG-Chol) that label cholesterol-rich domains. The production of nontoxic forms of lysenin as...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Methods to Monitor Fatty Acid Transport Proceeding Through Vectorial Acylation
The process of fatty acid transport across the plasma membrane occurs by several mechanisms that involve distinct membrane-bound and membrane-associated proteins and enzymes. Among these are the fatty acid transport proteins (FATP) and long-chain acyl CoA synthetases (Acsl). Previous studies in yeast and adipocytes have shown FATP and Acsl form a physical complex at the plasma membrane and are required for fatty acid transport, which proceeds through a coupled process-linking transport with metabolic activation termed vectorial acylation. At present, six isoforms of FATP and five isoforms of ACSL have been identified in mi...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Activity-Based Profiling of Lipases in Living Cells
The ultimate goal of proteomics is to characterize the function of all proteins in parallel and in the most physiologically relevant settings possible. A step toward this goal has been the introduction of activity-based proteomics. The simultaneous detection of individual protein activities can be facilitated directly in the proteome using specific activity-based probes consisting of a recognition site targeting a certain enzyme species, a properly positioned reactive site which forms a covalent bond with the target and a reporter tag for visualization and/or purification of the covalently bound target. As properties like ...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Histochemistry and Lipid Profiling Combine for Insights into Aging and Age-Related Maculopathy
Aging is the major risk factor for age-related maculopathy (ARM), the biggest cause of vision loss among the elderly in industrialized societies, and a major change in the affected tissues is the age-related accumulation of neutral lipid in Bruch’s membrane (BrM) of the eye throughout adulthood. Here we show that esterified cholesterol (EC) is the major neutral lipid species in this tissue, which has implications for potential sources of this material. The combination of filipin histochemistry and comprehensive lipid profiling made possible this insight on a complex tissue.
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Instrument-Independent Software Tools for the Analysis of MS–MS and LC–MS Lipidomics Data
Mass spectrometry (MS), particularly electrospray-MS, is the key tool in modern lipidomics. However, as even a modest scale experiment produces a great amount of data, data processing often becomes limiting. Notably, the software provided with MS instruments are not well suited for quantitative analysis of lipidomes because of the great variety of species present and complexities in response calibration. Here we describe the use of two recently introduced software tools: lipid mass spectrum analysis (LIMSA) and spectrum extraction from chromatographic data (SECD), which significantly increase the speed and reliability of m...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Computer-Assisted Interpretation of Triacylglycerols Mass Spectra
Triacylglycerols (TGs) are principal components of vegetable oils and animal fats. Natural TGs form extremely complex mixtures composed of tens or hundreds of molecular species. HPLC/MS suits well for their analyses, but manual data processing is laborious and time-consuming. Specialized software algorithms are needed to accelerate the interpretation process. Here we present software named TriglyAPCI for interpreting APCI, APPI, or ESI MS/MS spectra of TGs. The chapter shows how to build and use the software, what are its advantages and limitations. The algorithm uses diacylglycerol fragments and molecular adducts for dete...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Visualization of Complex Processes in Lipid Systems Using Computer Simulations and Molecular Graphics
Computer simulation has become an increasingly popular tool in the study of lipid membranes, complementing experimental techniques by providing information on structure and dynamics at high spatial and temporal resolution. Molecular visualization is the most powerful way to represent the results of molecular simulations, and can be used to illustrate complex transformations of lipid aggregates more easily and more effectively than written text. In this chapter, we review some basic aspects of simulation methodologies commonly employed in the study of lipid membranes and we describe a few examples of complex phenomena that ...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

Bioinformatics Strategies for the Analysis of Lipids
Owing to their importance in cellular physiology and pathology as well as to recent technological advances, the study of lipids has reemerged as a major research target. However, the structural diversity of lipids presents a number of analytical and informatics challenges. The field of lipidomics is a new postgenome discipline that aims to develop comprehensive methods for lipid analysis, necessitating concomitant developments in bioinformatics. The evolving research paradigm requires that new bioinformatics approaches accommodate genomic as well as high-level perspectives, integrating genome, protein, chemical and network...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

The Effect of Lipid Adjustment on the Analysis of Environmental Contaminants and the Outcome of Human Health Risks
Past literature on exposure to lipophilic agents such as organochlorines (OCs) is conflicting, posing challenges for the interpretation of their potential human health risks. Since blood is often used as a proxy for adipose tissue, it is necessary to model serum lipids when assessing health risks of OCs. Using a simulation study, we evaluated four statistical models (unadjusted, standardized, adjusted, and two-stage) for the analysis of polychlorinated biphenyls (PCBs) exposure, serum lipids, and health outcome risk. Eight candidate true causal scenarios, depicted by directed acyclic graphs, were used to illustrate the ram...
Source: Springer protocols feed by Cell Biology - October 1, 2009 Category: Cytology Source Type: news

ASCB wins NIH 'stimulus grant' to build virtual library of cell images for researchers and public
(American Society for Cell Biology) A $2.5 million "stimulus grant" announced yesterday by the National Institutes of Health will enable the American Society for Cell Biology to build an unprecedented, online image library of the cell that will be readily accessible to researchers, educators, students, and the public, according to ASCB Executive Director Joan Goldberg.
Source: EurekAlert! - Medicine and Health - October 1, 2009 Category: Global & Universal Source Type: news