Cognitive impairment resulting from the radiotherapeutic management of brain tumors represents a clinically intractable condition that adversely impacts quality of life. The capability to critically evaluate potential interventions for ameliorating radiation-induced cognitive decrements ultimately depends on the capability to undertake rigorous quantitative assessments of cognition.
Examining the Characteristics of Episodic Memory using Event-related Potentials in Patients with Alzheimer's Disease
The methodology for collecting high-density event-related potential data while patients with Alzheimer's disease perform a recognition memory task is reviewed. This protocol will include subject preparation, quality assurance, data acquisition, and data analysis.
The fabrication of microfluidic channels and their implementation in experiments for studying the chemotactic foraging behaviour of marine microbes within a patchy nutrient seascape and the swimming behaviour of bacteria within shear flow are described.
1Fischell Department of Bioengineering, University of Maryland, 2Institute for Bioscience and Biotechnology Research, University of Maryland, 3Department of Materials Science and Engineering, University of Maryland
This article describes a biofabrication approach: deposition of stimuli-responsive polysaccharides in the presence of biased electrodes to create biocompatible films which can be functionalized with cells or proteins. We demonstrate a bench-top strategy for the generation of the films as well as their basic uses for creating interactive biofunctionalized surfaces for lab-on-a-chip applications.
Split-Ubiquitin Based Membrane Yeast Two-Hybrid (MYTH) System: A Powerful Tool For Identifying Protein-Protein Interactions
1Department of Biochemistry, University of Toronto, 2Department of Molecular Genetics, University of Toronto, 3Terrence Donnelly Centre for Cellular and Biomolecular Research (CCBR), University of Toronto
MYTH allows the sensitive detection of transient and stable interactions between proteins that are expressed in the model organism Saccharomyces cerevisiae. It has been successfully applied to study exogenous and yeast integral membrane proteins in order to identify their interacting partners in a high throughput manner.
Here are some highlights from the October 2011 Issue of Journal of Visualized Experiments (JoVE).
In this article we describe the use of magnetic tweezers to study the effect of force on enzymatic proteolysis at the single molecule level in a highly parallelizable manner.
In this protocol, a novel application of scent discrimination is described. The Dig task is a reasonably inexpensive task that can be used to assess frontally-mediated cognition following brain damage.
1Department of Bioengineering, University of California, Berkeley, 2Department of Bioengineering, University of California, Berkeley; Division of Occupational Medicine, University of California, San Francisco
A new in vitro system for simultaneously loading four tendons in culture is described.
Right Ventricular Systolic Pressure Measurements in Combination with Harvest of Lung and Immune Tissue Samples in Mice
1Department of Environmental Medicine, New York University School of Medicine, Tuxedo, 2Division of Allergy, Pulmonary, & Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, 3Division of Pulmonary Medicine, New York University School of Medicine
A specific and rapid protocol to simultaneously investigate right heart function, lung inflammation, and the immune response is described as a learning tool. Video and figures describe physiology and microdissection techniques in an organized team-approach that is adaptable to be used for small to large sized studies.
Immunohistochemical Staining of B7-H1 (PD-L1) on Paraffin-embedded Slides of Pancreatic Adenocarcinoma Tissue
1The Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, 2Department of Oncology, The Johns Hopkins University School of Medicine, 3Department of Dermatology, The Johns Hopkins University School of Medicine, 4Department of Surgery, Johns Hopkins University School of Medicine, 5The Sol Goldman Pancreatic Cancer Center, The Johns Hopkins University School of Medicine, 6Yale Cancer Center, Yale School of Medicine, 7The Skip Viragh Center for Pancreatic Cancer, The Johns Hopkins University School of Medicine, 8Department of Pathology, The Johns Hopkins University School of Medicine
B7-H1 (PD-L1) and its binding to PD-1 provide a major tumor-induced immunosuppressive signal in the tumor’s microenvironment. An immunohistochemical staining technique to characterize the expression and localization of B7-H1 in pancreatic adenocarcinoma is described here.
We demonstrate fabrication of a simple microfluidic device that can be integrated with standard electrophysiology setups to expose microscale surfaces of a brain slice in a well controlled manner to different neurotransmitters.
Femoral Arterial and Venous Catheterization for Blood Sampling, Drug Administration and Conscious Blood Pressure and Heart Rate Measurements
Chronic catheterization of blood vessels in the rat is often required for administration of substances, obtain blood sample over a period of time or for direct conscious blood pressure measurements. Femoral arterial catheterization of the rat and corresponding measurements of blood pressure in the conscious animal will be demonstrated.
This protocol describes how to generate carbon fiber electrodes. The electrodes are subsequently used to detect catecholamine release from vesicles with carbon fiber amperometry.
This paper describes a protocol for whole body hyperthermia in mice that can stimulate fever like conditions up to 12-24 hr.
The dissection and growth of cells from an individual brain area facilitates investigation of cellular and physiological parameters. We describe a method for primary cell culturing that produces neuron-enriched cultures in a serum-free environment.
Analyzing the Function of Small GTPases by Microinjection of Plasmids into Polarized Epithelial Cells
This article details the procedures involved in overexpression and analysis of small GTPases in polarized epithelial cells using microinjection technique.
Single port laparoscopic surgery is changing the standard of care in surgical care like nothing since the laparoscopic technique was introduced 20 years ago. We present out technique of single port donor nephrectomy using the Gelpoint device. We have successfully performed this surgery in 100 patients.
Silk films are a novel class of biomaterials readily customizable for an array of biomedical applications. The presented silk film culture system is highly adaptable to a variety of in vitro analyses. This system represents a biomaterial design platform offering in vitro optimization before direct translation to in vivo models.
Endothelial corneal transplantation is a surgical technique for treatment of posterior corneal diseases. Mechanical microkeratome dissection to prepare tissue results in thinner, more symmetric grafts with less endothelial cell loss and improved outcomes. Dissections can be performed at the eye bank prior to corneal transplantation surgery.
Slice shear force is a reference method for beef texture analysis. Using an angle adjustable cutting box could increase its accuracy for research purposes. The results from different locations within the longissimus muscle show a high correlation with Warner-Bratzler shear force methodology and high potential adaptability for different muscles.
This article demonstrates the dissection and incubation of rabbit retina and particle-mediated gene transfer of plasmids encoding GFP or a variety of subcellular markers into retinal ganglion cells.
The cDNA microarray PtGen2 was developed for gene expression studies in loblolly pine, P. taeda, and other conifer species. Here, we show pre- and post-hybridization handling and washing techniques that can be used with this array to yield better consistency, reduced artifacts, and lower backgrounds.
This article describes various procedures for screening rats and mice to detect endo- or ectoparasitism. Several diagnostic assays will be demonstrated, both those suitable for use on live animals and those used after euthanasia of the animal. Photographs to aid in identification of rat and mouse parasites will be included.
1Neuroscience, Physiology and Pharmacology, University College London, 2Department of Clinical Neurophysiology, Great Ormond Street Hospital, 3Elizabeth Garrett Anderson Obstetric Hospital, University College Hospital, 4Nuffield Department of Anaesthetics, University of Oxford
The assessment and treatment of pain in infants is difficult because infants cannot verbally report their experience. In this video we describe quantitative electrophysiological methods and analysis techniques that can be used to measure the response to noxious events from the infant nervous system.
Here we describe the technique of preparing and maintaining compartmented chambers for culturing sensory neurons of the dorsal root ganglia.
Brain banking and systematic sampling of biological material provides the basis for unbiased stereology and maximizes the potential data obtained from each specimen.
The analytical ultracentrifuge (AUC) sample cell holds sample and reference buffer and during experiments and is exposed to high vacuum and rotor speeds up to 60,000 rpm. This video will demonstrate the rigorous attention to detail necessary for assembly, loading and alignment of this very important component of an AUC experiment.
Early embryonic lung organ culture is a very useful system to study epithelial-mesenchymal interactions. Both epithelial and mesenchymal morphogenesis proceeds under specific conditions that can be readily manipulated in this system.
The zebrafish kidney is home to both renal and hematopoietic adult stem/progenitor cells, and represents an outstanding opportunity to study these cell types and their progeny in a vertebrate model organism. Here, we demonstrate a detailed dissection procedure that enables the researcher to identify and surgically remove the adult zebrafish kidney, which can be used for applications such as cell isolation, transplantation, and expression studies of kidney and/or blood cell populations.
We describe the isolation of neonatal cardiomyocytes and the preparation of the cells for encapsulation in fibrin hydrogel constructs for tissue engineering. We describe methods for analyzing the tissue engineered myocardium after the culture period including active force generated upon electrical stimulation and cell viability and immunohistological staining.
In this protocol we combine RNAi-mediated gene silencing with an in vivo diuresis assay to study the effects knockdown of genes of interest has on mosquito fluid excretion.
A variety of growth factors and proteins interact to induce cells to take on different cell fates during development. Here we demonstrate the use of an in ovo preparation to address possible interactions between different proteins in development by placing beads on E2.5 chick embryos.
Allogeneic skin transplantation is a standard model to assay host T cell responses to MHC-disparate donor antigens. This video-article provides a visual tutorial of each step involved in performing a BALB/c-->C57BL/6 skin transplant.
We show a simple and rapid method to load pre-defined numbers of cells into microfabricated wells and maintain them for embryoid body development.
Recording Multicellular Behavior in Myxococcus xanthus Biofilms using Time-lapse Microcinematography
To study Myxococcus xanthus swarm behavior, we have designed a time-lapse microcinematography protocol that can be modified for different assays. It employs standard growth conditions adapted for microscopy, and yields reproducible results by the use of inexpensive, reusable silicone gaskets. We have used this method to quantify multicellular chemotaxis.
A precise murine model for acute kidney injury (AKI) due to ischemia is an important tool to investigate acute kidney injury and possibly find therapeutic tools to treat renal injury. The hanging weight system offers a tool for immediate and reliable renal artery occlusion and reperfusion without causing renal congestion.
The methodology for fabricating synthetic vocal fold models is described. The models are life-sized and mimic the multi-layer structure of the human vocal folds. Results show the models to self-oscillate at pressures comparable to lung pressure and demonstrate flow-induced vibratory responses that are similar to those of human vocal folds.
This report provides a visual depiction of parallel-plate flow chamber analysis for studying leukocyte endothelial interactions under physiologic shear stress. This method is particularly useful for investigating the role of endothelial (E)-selectin and leukocyte E-selectin ligands that trigger leukocyte rolling on endothelial cell surfaces.
Key to understanding the morphogenetic processes that shape the early embryo is the ability to image cells at high resolution. We describe here a technique for labeling single cells or small clusters of cells in whole zebrafish embryos with membrane-targeted Green Fluorescent Protein.
Antigens Protected Functional Red Blood Cells By The Membrane Grafting Of Compact Hyperbranched Polyglycerols
1Centre for Blood Research, University of British Columbia, 2Department of Pathology and Laboratory Medicine, University of British Columbia, 3Canadian Blood Services, University of British Columbia, 4Department of Chemistry, Life Sciences Centre, University of British Columbia
The cell membrane modification of red blood cells (RBCs) with hyperbranched polyglycerol (HPG) is presented. Modified RBCs were characterized by aqueous two phase partitioning, osmotic fragility and complement mediated lysis. The camouflage of surface proteins and antigens was evaluated using the flow cytometry and Micro Typing System (MTS) blood phenotyping cards.
Collection, Isolation and Enrichment of Naturally Occurring Magnetotactic Bacteria from the Environment
We demonstrate a method to collect magnetotactic bacteria (MTB) that can be applied to natural waters. MTB can be isolated and enriched from sediment samples using a relatively simple setup that takes advantage of the bacteria's natural magnetism. Isolated MTB can then be examined in detail using both light and electron microscopy.
This video shows the process of whole-cell voltage clamp recordings in the retinal slice of the aquatic tiger salamander. We demonstrate the preparation of the slice as well as how to perform patch clamp recordings during visual stimulation of the retina.
The cellular heterogeneity of brain tissue poses a significant limitation for the study of epigenetic markings in chromatin because most assays lack single cell resolution. Neurons typically are intermingled with glia and other non-neuronal cells. We provide a protocol to extract and collect neuronal nuclei from human brain.
Traumatic injury to the spinal cord disrupts communication with the brain. To restore lost connectivity we utilize a peripheral nerve graft to provide a substratum for regenerating fibers in combination with neurotrophic factors and matrix-modulating enzymes to remove inhibitory molecules to promote long distance growth.
Pseudofracture, a reproducible murine model of sterile musculoskeletal trauma, allows for evaluation of late term post-traumatic immune responses. This article describes the procedural execution of the model step by step, including the potential for experimental model combinations to permit study of multiple trauma.
Mice and rats, due to their innate cautiousness, are initially slow in consuming a novel food, particularly in a novel place. This hyponeophagia can readily be measured in the laboratory, even though laboratory animals are much less anxious than their wild counterparts
1Department of Neurology, McKnight Brain Institute, University of Florida, 2Department of Entomology and Nematology, University of Florida, 3Genetics Institute, Department of Molecular Genetics and Microbiology, University of Florida, 4McKnight Brain Institute, Department of Neuroscience, Genetics Institute, Center for Translational Research on Neurodegenerative Diseases, and Center for Movement Disorders and Neurorestoration, University of Florida
We describe here the procedures for the extraction and purification of mRNA and metabolites from Drosophila heads. We are applying these techniques to better understand the cellular perturbations underlying neuronal degeneration. These methodologies can be easily scaled and adapted for other "omic" projects.
1Department of Biomedical Engineering, University of California, Irvine (UCI), 2Stem Cell Research Center, University of California, Irvine (UCI), 3Institute for Brain Aging and Dementia, University of California, Irvine (UCI)
In this video we demonstrate how to use the neuron microfluidic device without plasma bonding.