<a href="https://www.jove.com/video/50175">Minimal Erythema Dose (MED) Testing</a>
Carolyn J. Heckman1, Rachel Chandler2, Jacqueline D. Kloss3, Amy Benson2, Deborah Rooney2, Teja Munshi1, Susan D. Darlow1, Clifford Perlis4, Sharon L. Manne5, David W. Oslin2
1Cancer Prevention and Control Program, Fox Chase Cancer Center, 2Department of Psychiatry, University of Pennsylvania, 3Department of Psychology, Drexel University, 4Department of Medicine, Fox Chase Cancer Canter, 5Cancer Prevention and Control Program, The Cancer Institute of New Jersey
This article describes how to conduct minimal erythema dose (MED) testing in order to determine the lowest dose of ultraviolet radiation that will cause erythema (burning) when administered to an individual.
<a href="https://www.jove.com/video/50344">Measuring Intracellular Ca2+ Changes in Human Sperm Using Four Techniques: Conventional Fluorometry, Stopped Flow Fluorometry, Flow Cytometry and Single Cell Imaging</a>
Esperanza Mata-Mart&iacute;nez1, Omar Jos&eacute;1, Paulina Torres-Rodr&iacute;guez1, Alejandra Sol&iacute;s-L&oacute;pez1, Ana A. S&aacute;nchez-Tusie1, Yoloxochitl S&aacute;nchez-Guevara1, Marcela B. Trevi&ntilde;o2, Claudia L. Trevi&ntilde;o1
1Departamento de Gen&eacute;tica del Desarrollo y Fisiolog&iacute;a Molecular, Instituto de Biotecnolog&iacute;a-Universidad Nacional Aut&oacute;noma de M&eacute;xico, 2Math and Sciences Department, Edison State College
Intracellular Ca2+ dynamics are very important in sperm physiology and Ca2+-sensitive fluorescent dyes constitute a versatile tool to study them. Population experiments (fluorometry and stopped flow fluorometry) and single cell experiments (flow cytometry and single cell imaging) are used to track spatio-temporal [Ca2+] changes in human sperm cells.
<a href="https://www.jove.com/video/50492">Air Filter Devices Including Nonwoven Meshes of Electrospun Recombinant Spider Silk Proteins</a>
Gregor Lang, Stephan Jokisch, Thomas Scheibel
Biomaterials Research Group, University of Bayreuth
Spider silk fibers display extraordinary mechanical properties. Engineered Araneus diadematus Fibroin 4 (eADF4) can be processed into nonwoven meshes using electrospinning. Here, the eADF4 nonwoven meshes are used to improve the performance of air filtering devices.
<a href="https://www.jove.com/video/4439">Ex vivo Live Imaging of Single Cell Divisions in Mouse Neuroepithelium</a>
Karolina Piotrowska-Nitsche1,2, Tamara Caspary1
1<a href="/institutions/NA-north-america/US-united-states/GA-georgia/24832-emory-university">Department of Human Genetics, Emory University School of Medicine</a>, 2Department of Experimental Embryology, IGAB Polish Academy of Sciences
Here we develop the tools necessary for ex vivo live imaging to trace single cell divisions in the mouse E8.5 neuroepithelium
<a href="https://www.jove.com/video/50047">Quantitative Analysis of Autophagy using Advanced 3D Fluorescence Microscopy</a>
Chun A. Changou1, Deanna L. Wolfson2, Balpreet Singh Ahluwalia3, Richard J. Bold4, Hsing-Jien Kung5, Frank Y.S. Chuang6
1Department of Biochemistry and Molecular Medicine, NSF Center for Biophotonics Science &amp; Technology, 2NSF Center for Biophotonics Science &amp; Technology, University of California, Davis, 3NSF Center for Biophotonics Science &amp; Technology, University of Troms&oslash;, 4Department of Surgery, University of California, Davis, 5Department of Biological Chemistry, University of California, Davis, 6Department of Biochemistry and Molecular Medicine, University of California, Davis
Autophagy is a ubiquitous process that enables cells to degrade and recycle proteins and organelles. We apply advanced fluorescence microscopy to visualize and quantify the small, but essential, physical changes associated with the induction of autophagy, including the formation and distribution of autophagosomes and lysosomes, and their fusion into autolysosomes.

No conflicts of interest declared.

may 2013: this month in jove

Here's a look at what's coming up in the <a href="http://www.jove.com/archive/75">May 2013 issue</a> of JoVE - The Journal of Visualized Experiments.
What came first: the chicken or the egg? This fundamental question lacks a vital component of reproduction: the sperm. Before anything can happen, a sperm cell must swim to the egg and fuse with it. These events are largely dependent on signal transduction pathways mediated by calcium ions (Ca2+). Therefore, to study sperm function, it is useful to measure changes in Ca2+ concentration in spermatozoa. This can be facilitated by calcium-sensitive fluorescent dyes, which <a href="http://www.jove.com/video/50344">Mata-Mart&iacute;nez et al.</a> use in four fluorometric techniques to monitor Ca2+ dynamics in human sperm: conventional fluorometry, stopped flow fluorometry, flow cytometry, and single cell imaging.
Moving along to another part of the male reproductive tract, we feature an article concerning prostate cancer, one of the leading causes of cancer deaths in men in the United States. In human prostate cancer cells, an enzyme called arginine deiminase (ADI) was recently demonstrated to induce autophagy, a mechanism of cell death in which a cell essentially eats its own components. To further study this mechanism, <a href="http://www.jove.com/video/50047">Changou et al.</a> developed an imaging-based approach using quantitative 3D fluorescence microscopy, allowing them to precisely track morphological changes as cells undergo autophagy. This technique will help researchers study potential therapeutics for prostate cancer.
In <a href="http://www.jove.com/bioengineering">JoVE Bioengineering</a>, past articles have presented methods for isolating silk-producing glands from spiders, producing recombinant spider silk proteins in bacteria, and spinning purified proteins into fibers for potential biomedical applications (<a href="http://www.jove.com/video/2382">Jeffrey et al., 2011</a>; <a href="http://www.jove.com/video/4191">Hsia et al., 2012</a>). This month, <a href="http://www.jove.com/video/50492">Lang et al.</a> present a new application for spider silk: making air filter devices with a nonwoven mesh of electrospun recombinant spider silk proteins. If commercial filters are coated with a layer of spider silk, their filtering efficiency may be improved. The authors demonstrate how to electrospin the fibers, treat the nonwoven silk meshes, and analyze the meshes using scanning election microscopy (SEM). Finally, the authors demonstrate air permeability and filter efficiency.
In <a href="http://www.jove.com/ctm">JoVE Clinical &amp; Translational Medicine</a>, <a href="http://www.jove.com/video/50175">Heckman et al.</a> demonstrate a method for determining the lowest dose of ultraviolet light that will cause erythema (sunburn) in an individual. UV light is often used to treat various skin conditions, such as psoriasis, acne, and eczema; because not all people are equally sensitive to UV light, this method can help determine the appropriate dose to administer. A Daavlin patch is used to control both the area and duration of UV exposure on the skin. The next day, changes in skin color are assessed to determine the lowest UV dose required to cause erythema.
In <a href="http://www.jove.com/neuro">JoVE Neuroscience</a>, <a href="http://www.jove.com/video/4439">Piotrowska-Nitsche and Caspary</a> demonstrate how to culture slices of embryonic mouse neuroepithelium and perform live imaging of various fluorescent markers. This method allows researchers to monitor cell behavior, such as single cell divisions, in situ and in real time.
You've just had a preview of some of JoVE's highlights for the month of May. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments.

Watch this Scientific Journal Video about May 2013: This Month in JoVE at JoVE.com

May 2013: This Month in JoVE

Here are some highlights from the May 2013 Issue of Journal of Visualized Experiments (JoVE).

Here's a look at what's coming up in the May 2013 issue of JoVE - The Journal of Visualized Experiments.
What came first: the chicken or the egg? This ...

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8.2K Aufrufe.  Massachusetts Eye and Ear. Hier sind einige Highlights aus dem Mai 2013 Ausgabe des Journal of Visualized Experiments (JoVE).

Serie: May 2013: This Month in JoVE

December 2011: This Month in JoVE

The Journal of Visualized Experiments (JoVE) closes 2011 with a December issue that begins by honoring World's AIDS Day with an article that deals with visualizing the structure of HIV envelope glycoproteins, which are a critical component of the viral infection pathway.
One key method for determining virion envelope structure is cryo-electron tomography. Prior to using this technique, soluble virus must be vitrified on a gold grid - a process that involves adding gold to a viral suspension, transferring that suspension to the grid, and plunging the grid into liquid ethane. The virus particles, present in a thin film of liquid atop the grid, are frozen at a rate greater than 100,000 K per second. Following vitrification, collected samples are loaded into the electron microscope and precisely defined regions on the grid are hit with a focused electron beam, while the grid is tilted. The tilt series that results from these imaging sessions is comprised of hundreds of individual images, which must be aligned and averaged to resolve individual envelope proteins. This computationally intense process often requires computer clusters, capable of remote-access parallel processing, like NIH's Biowulf.
Once completed, 3D models can not only provide insight into the structure of envelope glycoproteins themselves, but can also reveal the manner in which they interact other proteins, like the neutralizing antibody B12, which is information that can greatly influence vaccine design.
This article, from the laboratory of Dr. Sriram Subramaniam involves contributions from twenty authors, including not only graduates students and postdocs, but also middle and highschool students, showing that you are never too young to make an impact in the fight against a disease that has infected over 60 million people, worldwide.
In Clinical and Translational Medicine, JoVE presents an article from the University College London and the University of Oxford that investigates the physiological correlates of nociception, or pain sensation, in infants. Typically, infants respond to noxious stimuli by crying and changing their facial expressions - reactions considered to be autonomic and reliant on subcortical regions of the brain.
In order to understand the involvement of the cerebral cortex and spinal cord in infant nociception our authors first prepare infants for EEG and EMG recordings. They also set up physiological monitoring and video recording, so that the infant's facial expressions can be linked to physiological data. Following assessment of infant responses to neutral tactile stimuli, the baby is subjected to heel lancing - a clinical procedure used to obtain blood samples from infants. After data processing, electrical potentials can be compared between noxious and non-noxious stimuli in these infants, which will hopefully lead to meaningful conclusions, regarding how nociceptive information is interpreted by newborns.
JoVE's Bioengineering section takes a more clinical focus in December with an article from the University of Wisconsin, Madison, which involves the fabrication of a compartmentalized microfluidic device for studying cancer stem cell migration. Following device design, master molds are created by photolithography for the application of poly dimethyl siloxane (PDMS)- an organosilicon compound that is transparent and biologically inert - making it suitable for microfluidics applications with live cells. Specifically, our authors load tumor stem cells derived from multiform glioblastoma, a highly malignant brain cancer, into the compartmentalized devices and then place them in a specialized imaging system that acquires data over a few days. 
Time lapse video from these authors show that cancer stem cells are able to regulate their morphology in the size-constrained microfluidic channels much like they would in the interstitial space, and fluidic isolation made possible by chambers like these facilitates drug screening for potential therapeutics that can affect cancer stem cell migration.
Late on in the month, JoVE travels to France, where investigators from the Institute Pasteur and the Centre National de la Recherche Scientifique, illustrate a method for inducing expression of channel-rhodopsin, a light-activated ion channel, into the olfactory bulb of mice, as well as subsequent neuronal stimulation using a miniature light emitting diode (LED).
Our authors give detailed step-by-step instructions for preparing injection needles, and for precise injection of virus into the rostral migratory stream, a site of migration for adult born neuroblasts. Furthermore, they show how miniature LED stimulation devices are fabricated, calibrated, and implanted atop a cranial window prepared over the bulb. In particular, our authors are interested in the way that adult born neurons integrate into existing olfactory neuronal circuits, and they show that LED stimulation in awake behaving animals, can lead to activation of virally-tranduced neuroblasts in the olfactory bulb, which have migrated from the rostral migratory stream.
These video-articles comprise JoVE's highlights for the month of December. Other noteworthy upcoming articles illustrate methods for patterning conductive inks into microelectrodes, measuring cytosolic calcium in contractile lymphatics, and imaging neuronal responses to pheromones in the vomeronasal organ.

Here are some highlights from the December 2011 Issue of Journal of Visualized Experiments (JoVE).

The Journal of Visualized Experiments (JoVE) closes 2011 with a December issue that begins by honoring World's AIDS Day with an article that deals with ...

Research

JoVE Journal

Biology

October 2012: This Month in JoVE

Here are some highlights from the October 2012 issue of Journal of Visualized Experiments (JoVE). Gr&oslash;nlund et al. demonstrate how to isolate and analyze specific cell types in plant leaves expressing green fluorescent protein (GFP) using fluorescence-activated cell sorting (FACS). This method overcomes the interfering fluorescence of the chlorophyll found in leaves, and distinguishes GFP-expressing protoplasts from non-GFP protoplasts. In JoVE Neuroscience, Babona-Pilipos et al. demonstrate how to construct a chamber for measuring galvanotaxis, or cell migration within an electric field. Through time-lapse imaging and image analysis, the authors can study the migratory behavior of neural precursor cells in an electric field, which may lead to the use of electrical stimulation to direct neural precursors to sites of injury or disease. Articles involving microfluidic platforms have a significant publication history in JoVE. Harris et al. have released three articles, which involve a microfluidic device for separating axons from neuronal cell bodies. This month in JoVE Neuroscience, Higashimori et al. use this microfluidic platform to investigate the interactions between neuronal axons and glial cells, which are critical for the physiological function of the nervous system. In JoVE Bioengineering, two research groups demonstrate the novel bioadhesive properties of chitosan-a polymer derived from chitin, which is found in fungal cell walls or in the exoskeletons of crustaceans and insects. Chitosan is used in many industrial and agricultural applications, and bioengineers are also finding uses for it in surgical applications. Foster et al. have developed a laser-activated surgical film called Surgilux, which combines chitosan with indocyanine green ICG), a photosensitive dye. This surgical film binds strongly to tissue, such as muscle, after laser irradiation. Lauto et al. developed a surgical film that combines chitosan with the photoactive dye, rose Bengal. This novel film also binds strongly to tissues, such as intestine, after it is irradiated. These adhesive films are biocompatible and may potentially be used in various surgical procedures in place of sutures. In JoVE Clinical and Translational Medicine, Fiema et al. demonstrate a high-throughput technique for validating biomarkers in graft vs. host disease, a common and life-threatening complication of cell or tissue transplantation. The authors use commercially available ELISAs to analyze multiple proteins in sequential fashion. In JoVE Immunology and Infection, Keyel et al. demonstrate how to measure the real-time kinetics of immune cell responses to bacterial toxins using high-speed live cell microscopy. This method can be used to show how immune cells respond to bacterial toxins. Combined with high-speed 3D confocal microscopy, this technique can also visualize the cellular repair response. In JoVE Applied Physics, Borisenko et al. determine the electronic structure of complex materials using angle-resolved photoemission spectroscopy in a synchotron radiation facility. By combining recent advances in synchotron radiation, surface science, and cryogenics, this method can gain a precise picture of the energy and momentum of electrons inside a solid, and address key questions in the field of condensed matter physics. This preview summarizes just a few of the notable video-articles available in the October 2012 issue of JoVE. For additional videos, please visit <a href="http://www.jove.com">www.jove.com</a>.

Here are some highlights from the October 2012 Issue of Journal of Visualized Experiments (JoVE).

Here are some highlights from the October 2012 issue of Journal of Visualized Experiments (JoVE).  Gr&oslash;nlund et al. demonstrate how to isolate and ...

2012: A Year In Review

Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).
At the start of 2012, JoVE reached a major milestone by publishing our 1500th article. In this publication, in JoVE Bioengineering, Yu et al. described a method for analyzing the free radical composition of cigarette smoke. This method simulated cigarette puffing with a single-port smoking device, and combined it with electron spin resonance (ESR) spectroscopy to measure the degree to which antioxidant compounds can scavenge free radicals in cigarette smoke. A possible outcome of this research is the creation of less harmful cigarettes.
JoVE Bioengineering also contained the most-viewed article of 2012. Owczarczak et al. described a method for hacking a standard inkjet printer, loading ink cartridges with a cell-suspension "bioink," and printing lines of live cells onto glass slides. The thermal inkjet printing process creates temporary pores in the cell membrane, visualized by the incorporation of fluorescently labeled actin monomers. This concept, called "bioprinting," has many potential applications in cell and tissue engineering.
Also in 2012, JoVE Bioengineering featured a protocol by Hsia et al. for isolating and purifying spider silk protein, spinning it into fibers, and assessing the fiber strength. This protocol for laboratory-scale production of spider silk, which is stronger than tensile steel, can potentially be extended to large-scale manufacturing.
In JoVE Clinical and Translational Medicine, we featured a number of articles related to stroke, one of which. In one article, M&ouml;bius-Winkler et al. demonstrated placement of the WATCHMAN left atrial appendage occlusion device from Boston Scientific. This device is designed to prevent strokes by trapping clots within the left atrial appendage of the heart before they exit. Our authors demonstrated how to insert the guide wire through the femoral artery into the heart, advance the device into the left atrium, and deploy the device in the left atrial appendage.
Another article focused on stroke, Hamel et al. described the use of a driving simulator to study how patients compensate for visual field defects following stroke. By analyzing the compensatory gaze behavior of patients as they navigated through virtual driving courses with varying degrees of complexity, our authors see great potential for the use of driving simulators in stroke rehabilitation.
In JoVE Immunology and Infection, we published an article by Keyel et al. describing the real-time kinetics of immune cell responses to bacterial toxins using live cell microscopy. Combined with high-speed 3D confocal microscopy, this technique can also visualize the cellular repair response.
Also in JoVE Immunology and Infection, we featured an article by Yap et al. describing methods for diagnosing helminth infections in children. Helminths are parasitic worms that can infect the intestinal tract of humans and animals, and may be distinguished based on their morphology. The same article demonstrated how to measure the impact of helminth infections on physical fitness in children, which is a measure of overall health.
In JoVE Neuroscience, we featured a method by Hoffmann et al., who used tiny headphones to alter the auditory feedback in songbirds, and analyzed the computational and neurophysiological basis of vocal learning in birds when they adjust their singing in response to altered acoustic signals.
Also in JoVE Neuroscience, we moved from birds to bees with a method that assesses associative and non-associative tactile learning in honeybees. This method, by Mujagi&#263; et al., allowed bees to scan different metal surfaces with their antennae, then conditioned them to expect sugar water when their antennae touched particular surfaces, and analyzed the corresponding changes in antennal movement.
In 2012, we launched a brand-new section: JoVE Applied Physics, which features articles on subjects ranging from plasma physics to material science. The Applied Physics section also contained JoVE's 2000th video article, filmed in a synchrotron radiation facility, where Borisenko et al. showed how to determine the electronic structure of complex materials using angle-resolved photoemission spectroscopy.
In the JoVE General section, we published an article by Artioli et al. demonstrating the use of a portable gas analyzer to measure oxygen consumption during complex exercise - such as judo. By analyzing oxygen consumption and collecting blood for measuring plasma lactate concentration, this method can determine the relative contributions of different energy systems to specific aspects of complex exercise.
Finally, JoVE followed Dolhi et al. to a permanently ice-covered saline lake in Antarctica. There, scientists drilled through the ice to study single-celled microorganisms called protists that live in the harsh conditions of Antarctica.
This Year in Review was just a brief glimpse of a few of over 600 video articles that JoVE offered in 2012. Browse the JoVE archives to see thousands of other videos, and stay tuned for what's coming up this year in JoVE: The Journal of Visualized Experiments.

Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).

 
 
Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).
At the start of 2012, JoVE ...