<h2 class="jove_title"><a href="https://www.jove.com/video/3709">Hybridization in situ of salivary glands, ovaries and embryos of vector mosquitoes</a></h2>
Jennifer Juhn1, Anthony A. James2, 1 1Department of Molecular Biology and Biochemistry, University of California, Irvine , 2Department of Microbiology and Molecular Genetics, University of California, Irvine 
Temporal and spatial gene expression analyses have a crucial role in functional genomics. Whole-mount hybridization in situ is useful for determining the localization of transcripts within tissues and subcellular compartments. Here we outline a hybridization in situ protocol with modifications for specific target tissues in mosquitoes.
<h2 class="jove_title"><a href="https://www.jove.com/video/3763">Studying Mitotic Checkpoint by Illustrating Dynamic Kinetochore Protein Behavior and Chromosome Motion in Living Drosophila Syncytial Embryos</a></h2>
Maureen Sinclair1, Jun-Yong Huang2, 1 1Institute for Cell and Molecular Biosciences, University of Newcastle, United Kingdom, 2Institute for Cell and Molecular Biosciences, University of Newcastle
The kinetochore is where the SAC initiates its signal monitoring the mitotic segregation of the sister chromatids. A method is described to visualize the recruitment and turnover of one of the kinetochore proteins and its coordination with the chromosome motion in Drosophila embryos using a Leica laser scanning confocal system.
<h2 class="jove_title"><a href="https://www.jove.com/video/3765">A simplified technique for In situ excision of cornea and evisceration of retinal tissue from human ocular globe</a></h2>
Mohit Parekh1, Stefano Ferrari1, Enzo Di Iorio1, Vanessa Barbaro1, Davide Camposampiero1, Marianthi Karali2, Diego Ponzin1, Gianni Salvalaio3, 1 1Fondazione Banca Degli Occhi del Veneto O.N.L.U.S. , 2Telethon Institute for Genetics &#38; Medicine (T.I.G.E.M.), 3Fondazione Banca Degli Occhi del Veneto, O.N.L.U.S.
The paper describes a simplified technique to excise corneal and to eviscerate retinal tissues from the ocular globe of human cadaveric donors. The technique described here will help to excise good quality tissues to be used for transplantation, surgical or research purposes without damaging other tissues of the ocular globe.
<h2 class="jove_title"><a href="https://www.jove.com/video/3813">Efficient differentiation of mouse embryonic stem cells into motor neurons</a></h2>
Chia-Yen Wu1, Dosh Whye2, 1, Robert W. Mason1, Wenlan Wang1 1Nemours Biomedical Research, Alfred I. duPont Hospital for Children, 2Department of Pediatrics, Columbia University Medical Center
We developed a new protocol to improve efficiency of in vitro differentiation of mouse embryonic stem cells into motor neurons. The differentiated ES cells acquired motor neurons features as evidenced by expression of neuronal and motor neuron markers using immunohistochemical techniques.
<h2 class="jove_title"><a href="https://www.jove.com/video/3847">Corneal Donor Tissue Preparation for Endothelial Keratoplasty</a></h2>
Maria A. Woodward1, Michael Titus2, Kyle Mavin2, Roni M. Shtein1 1Department of Ophthalmology, University of Michigan , 2MidWest Eye Banks
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.
<h2 class="jove_title"><a href="https://www.jove.com/video/3958">Endothelialized microfluidics for studying microvascular interactions in hematologic diseases</a></h2>
David R. Myers1, 2, 3, 4,*, Yumiko Sakurai1, 2, 3, 4,*, Reginald Tran1, 2, 3, 4, Byungwook Ahn1, 2, 3, 4, Elaissa Trybus Hardy1, 2, 3, 4, Robert Mannino1, 2, 3, 4, Ashley Kita1, 2, 3, 4, Michelle Tsai1, 2, 3, 4, Wilbur A. Lam1, 2, 3, 4 1Department of Pediatrics, Emory University School of Medicine, 2Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 3Aflac Cancer Center and Blood Disorders Service of Children&#39;s Healthcare of Atlanta , 4Winship Cancer Institute of Emory University * These authors contributed equally
A method to culture an endothelial cell monolayer throughout the entire inner 3D surface of a microfluidic device with microvascular-sized channels (&lt;30 &mu;m) is described. This in vitro microvasculature model enables the study of biophysical interactions between blood cells, endothelial cells, and soluble factors in hematologic diseases.
<h2 class="jove_title"><a href="https://www.jove.com/video/3993">Recording Human Electrocorticographic (ECoG) Signals for Neuroscientific Research and Real-time Functional Cortical Mapping</a></h2>
N. Jeremy Hill1, Disha Gupta2, 1, Peter Brunner2, 1, Aysegul Gunduz2, 1, Matthew A. Adamo3, Anthony Ritaccio2, Gerwin Schalk1, 2, 4, 5, 6, 7 1Wadsworth Center, New York State Department of Health, 2Department of Neurology, Albany Medical College, 3Department of Neurosurgery, Albany Medical College, 4Department of Neurosurgery, Washington University, 5Department of Biomed. Eng., Rensselaer Polytechnic Institute, 6Department of Biomed. Sci., STATE UNIVERSITY OF NEW YORK AT ALBANY, 7Department of Elec. and Comp. Eng., University of Texas at El Paso 
We present a method for collecting electrocorticographic signals for research purposes from humans who are undergoing invasive epilepsy monitoring. We show how to use the BCI2000 software platform for data collection, signal processing and stimulus presentation. Specifically, we demonstrate SIGFRIED, a BCI2000-based tool for real-time functional brain mapping.

Pas de conflits d&#39;intérêt déclarés.

june 2012: this month in jove

Back in 1905, in what is now the Czech Republic, Eduard Zirm performed the first corneal transplantation surgery (keratoplasty), which restored vision to a patient blinded by corneal injury. Today, eye banks all over the world prepare, store, and distribute donated corneas to hospitals so that thousands of sight-saving keratoplasties can be performed every year. In June 2012, JoVE has its eye on two research groups, one from Italy and the other from Michigan, who demonstrate two distinct methods for corneal graft preparation prior to transplantation.
Our authors from Italy show us their technique for excising the cornea from the ocular globe, which involves first dunking it in a series of sterilizing solutions preparing it for sterile handling, creating an incision on the scleral surface, and ultimately separating the corneal-scleral rim away from the globe. Once the cornea is removed, the endothelial cell density and viability is checked and it is prepared for long-term storage, during which time the media is periodically tested in high-throughput fashion with other grafts deposited at the eye bank.
In corneal transplantation surgeries, full-thickness grafts are used in a procedure called penetrating keratoplasty; however, JoVE learns that in some diseased corneas, only the endothelial layer is affected. Our authors from the University of Michigan &amp; Midwest Eye Bank demonstrate further processing of donor corneas with Descemet's stripping automated endothelial keratoplasty (DSAEK), a procedure that involves grafting only the corneal endothelial layer. This relatively recent procedure is made possible via the use of a microkeratome, a device that can precisely cut through the cornea so that the endothelial layer can be separated for transplantation. The uniformity and quality of the donor tissue is verified using slit lamp and specular microscopy, and the graft is stored for corneal transplantation surgery.
Together, two groups of authors, from different continents, have documented the steps for removing the entire cornea from the eye and isolating the posterior layer for endothelial keratoplasty - a process that decreases the risk of infection or graft rejection and improves a patient's ability to see.
In JoVE Neuroscience, a multidisciplinary team of clinicians and scientists introduce new research applications of the electrocorticography (ECoG). The ECoG is an invasive procedure that uses strip and grid electrodes placed directly on the brain to localize seizure foci in epilepsy patients. This procedure can also be used to map cortical regions that need to be spared during resective surgery. Cortical mapping is accomplished by monitoring whether stimulation of a given electrode results in the disruption of movement or speech. Patients are typically subjected to intracranial monitoring to locate seizure foci for about a week, and this duration provides a unique window of opportunity for researchers to study the human brain in action with the ECoG, which has better signal-to-noise properties and less susceptibility to recording artifacts than the noninvasive electroencephalography (EEG).
After determining baseline activity at rest, our authors record brain activity in the high gamma frequency range, during simple cognitive, or motor tasks. Then, these investigators demonstrate how to use the SIGFRIED software system to perform rapid, real-time functional mapping based on ECoG signals, which are further analyzed to provide information regarding the brain regions associated with particular tasks.
In Bioengineering, JoVE encounters a team of scientists who show that the microvasculature can be approximately recreated on a chip. This "chip" is actually a device with microfluidic channels that are coated with endothelial cells. SU-8 photolithography is used to etch the channel pattern onto a silicon wafer, which acts as a mold for PDMS. Once the device has been fabricated, it is seeded with endothelial cells, which are cultured in the channels. Thanks to the transparency of PDMS, the cells can be imaged via microscopy. This in vitro model of the microvasculature provides a controlled microenvironment that can be used to study normal hemodynamic processes as well as in hematologic disease.
This short summary is a mere glimpse at some of JoVE's content for the month of June. Further investigation might lead one to methods for in situ hybridization of adult mosquito tissue and embryo, visualizing mitosis in drosophila, and differentiating embryonic stems cells into motor neurons. Stay tuned.

Watch this Scientific Journal Video about June 2012: This Month in JoVE at JoVE.com

June 2012: This Month in JoVE

Juin 2012: Ce mois-ci dans JoVE

Back in 1905, in what is now the Czech Republic, Eduard Zirm performed the first corneal transplantation surgery (keratoplasty), which restored vision to ...

Research

JoVE Journal

Biology

Vidéo: June 2012: This Month in JoVE

August 2012: This Month in JoVE

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and mirrors to refract and direct light to optical sensors. The August 2012 issue of JoVE (Journal of Visualized Experiments) is marked by the third publication from the Ozcan Lab (University of California, Los Angeles) on their lens free lens-free "on-chip" microscopy platform, which they have pioneered.
Back in 2009, the Ozcan lab published their first article, which demonstrated the use of a lens-free imaging platform that could image cells within whole blood. This imaging technique involves placing a sample directly on an optoelectric sensor array, like the CCD or CMOS chips found in the standard camcorder. Then, LED illumination from above the sample casts shadows on the chip, which are recorded as digital holograms that can be subjected to image processing. Not only does this lensless imaging system allow for an extremely large field of view (FOV of 0.6-8 cm2), the lack of bulky optical components makes it excellent for microfluidic applications. The Ozcan group demonstrates this in their follow-up 2011 JoVE article, in which fluorescently labeled white blood cells are imaged within a microfluidic chip.
This August in JoVE, the Ozcan group demonstrates further advancements to their lens-free microscopy platform by applying it to tomographic imaging of the nematode, C. elegans. By changing the angle of illumination, using a motorized rotation stage, the Ozcan group shows how multiple holographic slices may be generated for a sample-which, following processing, can be combined into tomograms. The Ozcan group confirms that their 3D reconstruction of the worm is successful by citing that the pharyngeal tube, a 5-micron-thick structure, is only visible in a single slice and in a 3D reconstructed cross section.
The compact and inexpensive nature of the lens-free imaging systems - designed and assembled by the Ozcan group - make them well suited for point-of-care diagnostic applications, or even cell phone based microscopy that can be performed in the field.
At the Ernest Gallo Clinic and Research Center at University of California, San Francisco JoVE learns how to visualize morphological changes in single cells using three-dimensional fluorescence microscopy and computer analysis. In this procedure, cells are given agonist, antagonist plus agonist, or no treatment, and prepared for immunofluorescence microscopy. Three-dimensional images are acquired with the help of a two-photon laser system, and the fluorescence data are processed on the computer using Imaris and Matlab.
To demonstrate the power of this technique, our authors quantify single-cell phenotypic changes in transfected HEK293 cells. Three-dimensional morphometric analysis shows dramatic changes in cells treated with agonist. These changes are not always apparent when using conventional 2D analysis. This technique allows morphological changes in single cells to be quantified and characterized in response to pharmacologic stimuli, offering a powerful new assessment tool to the arsenal of drug discovery research.
This month, in JoVE Applied Physics, we travel to South Carolina to visit the School of Materials Science and Engineering at Clemson University. Here, researchers show us how to construct lithium batteries for laboratory research.
The basic components of a lithium coin cell are the working electrode, the lithium electrolyte, and a lithium foil counter electrode. The different components of the coin cell are carefully assembled and sealed with a crimping machine. The finished coin cell can then be characterized in a battery tester. Using their homemade coin cells, our researchers can experiment with using different materials to make the cathodes of lithium coin cells.
This month in JoVE Immunology and Infection, we head to Basel, Switzerland to witness two techniques for diagnosing helminth infections. We also see how investigators perform the shuttle run test in children, in order to assess the effects of these infections on physical fitness.
Helminths are parasitic worms that can live inside humans and animals. Many species infect the intestinal tract, and may be transmitted through soil. Our authors demonstrate the Kato-Katz technique, which is used for diagnosing several common soil-transmitted helminths. They also demonstrate the Baermann technique, which uses light to stimulate the migration of certain types of phototactic helminths out of sample preparations. The various types of helminth species can subsequently be determined based on morphology.
Our authors then demonstrate how to set up and perform a 20-meter shuttle run test for children, and to measure the impact of helminth infections on physical fitness. This method can help determine the true burden of soil-transmitted helminth infections on overall health.
This brief summary highlights but a few notable video-articles that will be released in August. We'll also feature articles that demonstrate how to express genes in the midbrain of the chick embryo, study neutrophil transmigration in parallel flow chambers lined with endothelial cells, and precisely measure proteolytic degradation of the extracellular matrix.

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and mirrors to refract and direct light to optical sensors. The August 2012 issue of JoVE (Journal of Visualized Experiments) is marked by the third publication from the Ozcan Lab (University of California, Los Angeles) on their lens-free "on-chip" microscopy platform, which they have pioneered.

Août 2012: Ce mois-ci dans JoVE

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and ...

Recherche

Biologie

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).

2012: Une année en revue

 
 
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 ...

Juin 2012: Ce mois-ci dans JoVE

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Août 2012: Ce mois-ci dans JoVE

2012: Une année en revue