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Chao W.,Massachusetts Eye and Ear Infirmary | Kolski-Andreaco A.,JoVE Content Production
Journal of Visualized Experiments | Year: 2016

Here's a look at what's coming up in the March 2016 issue of JoVE: The Journal of Visualized Experiments. In JoVE Biology, RNA interference (RNAi) is a natural mechanism of gene silencing that occurs via double-stranded RNA (dsRNA), which targets homologous DNA for degradation. This phenomenon allows researchers to selectively silence genes in many eukaryotes-making RNAi an extremely valuable tool for uncovering gene function. However, in the mosquito Anopheles gambiae, a major vector for malaria, RNAi has limited ability to target genes during developmental stages. This month, Regna et al. present an RNAi protocol using direct injection during pupal development. After the pupae complete development, their adult phenotypes confirm the gene knockdown. This method expands the arsenal of genomic tools for vector insect research. In JoVE Developmental Biology, induced pluripotent stem cells (iPSCs) have been generated from many cell types, and are valuable models for human development and disease. iPSCs are also valued for their potential applications in regenerative medicine. This month, Ulm et al. demonstrate methods for sampling nasal epithelial mucosa from children, then culturing the samples to obtain nasal epithelial cells (NECs), which are reprogrammed into iPSCs. NECs are of particular interest because they're the primary cells infected with respiratory viruses, and are readily accessible during clinical visits. Therefore, this protocol facilitates patient-specific research in airway epithelial biology. In JoVE Environment, filters are important tools in atmospheric aerosols research. These sampled filters collect ambient particles, such as endotoxins and biological aerosols, for analysis. In this issue, Lang-Yona et al. use air-sampled filters for two complementary analyses of atmospheric biological particles: endotoxin and DNA. Specifically, they study endotoxin components of gram-negative bacterial cell walls, known collectively as lipopolysaccharide (LPS). In parallel, they perform a genomic evaluation of the sample's bacterial content. This method can produce highly accurate and reliable analyses for biological aerosol research. In JoVE Medicine, researchers are finding new ways to treat wounds with a patient's own tissues, This month, Purpura et al. describe a new method of creating autologous micrografts. When cultured on collagen sponges, these micro-grafts become bio-complexes ready to use in the treatment of skin lesions. These biocomplexes were applied in a patient, who showed good healing after 30 days. This new regenerative approach shows promise as an efficient, one-step treatment of acute and chronic lesions. You've just had a sneak peek of the March 2016 issue of JoVE. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments. © 2016 Journal of Visualized Experiments. Source


Chao W.,Massachusetts Eye and Ear Infirmary | Kolski-Andreaco A.,JoVE Content Production
Journal of Visualized Experiments | Year: 2016

Here’s a look at what’s coming up in the February 2016 issue of JoVE: The Journal of Visualized Experiments. In JoVE Developmental Biology, the transparent, rapidly developing zebrafish embryo is ideal for visualizing developmental processes. When cells of interest are labeled with fluorescent photoconvertible proteins, they allow precise tracking of defined structures-highlighting specific cells while leaving other transgenic cells in the dark. Beretta et al. have established the photoswitchable monomeric orange (PSmOrange) system for zebrafish. This protein’s orange-to-red spectrum allows it to visible in existing transgenic lines expressing green fluorescent protein (GFP). Microinjection of nuclear-targeted PSmOrange mRNA labels all cell nuclei with orange/red fluorescence, and targeted photoconversion switches its emission spectrum to far red. The quantum efficiency and stability of PSmOrange makes it a superb cell-tracking tool for living zebrafish during embryonic development and disease. In JoVE Chemistry, few materials have found as many uses in so many diverse fields as gold nanoparticles. Their applications range from biological sensors to radio frequency-based cancer treatments. Gold nanoparticles are valued for their unique structural, optical and electronic properties. These special attributes caught the interest of Oliver Smithies, who won the Nobel Prize in Physiology or Medicine in 2007. This month, he and his colleagues describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles, and present models that can predict particle size with great accuracy. In JoVE Engineering, we look at the principles of positron emission tomography (PET), a non-invasive technique for imaging the body's inner tissues and organs. Montaño-Zetina and Villalobos-Mora present a guide for constructing a simple, homemade PET system for fully characterizing its basic working principles. This prototype demonstrates the primary functions of PET, and serves as an elegant model for teaching its principles to the academic public. In JoVE Medicine, it is well established that the bone marrow microenvironment provides a haven for hematopoietic diseases. This month, Slone et al. use cell types from the bone marrow niche in an in vitro co-culture model. This supports the generation of a subpopulation of chemoresistant tumor cells. These calls can be used to investigate the underlying pathways of tumor development and to test novel therapeutic strategies. You’ve just had a sneak peek of the February 2016 issue of JoVE. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments. © 2016 Journal of Visualized Experiments. Source


Chao W.,Massachusetts Eye and Ear Infirmary | Kolski-Andreaco A.,JoVE Content Production
Journal of Visualized Experiments | Year: 2015

Here's a look at what's coming up in the December 2015 issue of JoVE: The Journal of Visualized Experiments. In JoVE Immunology & Infection, we know that the peak of flu season is on its way-and because pigs are important hosts for the influenza A virus, it is critical to monitor virus evolution in swine populations to get a snapshot of current circulating strains. Nasal swabs are a gold-standard technique for taking diagnostic samples from live pigs, but it requires restraining the pigs. Nolting et al. present an alternative sampling method using nasal wipes, which involves rubbing a piece of fabric across the snout of the pig with minimal to no restraint of the animal. The nasal wipe procedure is simple to perform, and virus detection and isolation rates are adequate to make it a viable and low-stress sampling method for flu in pigs. In JoVE Chemistry, DNA nanorobots are hollow hexagonal nanodevices that open in response to specific stimuli to present the cargo sequestered inside. This month, Amir et al. describe a nanorobot fabrication protocol that uses the DNA origami technique. This involves mixing short single-stranded DNA staples with long, circular, single-stranded DNA scaffolds. In a standard thermocycler, the staples anneal to the scaffolds, thus driving the folding of the nanorobot. After the folding reaction is complete, agarose gel electrophoresis (AGE) is used to visualize and estimate the purity of the DNA nanorobots. Finally, nanorobot fabrication is verified by transmission electron microscopy (TEM). This procedure allows for the construction of complex 2D/3D nano-architecture. In JoVE Environment, crude oil is one of the most valuable natural resources because it is the raw material for many fuels and chemical products. Accurate analysis of crude oil, especially the content of highly toxic hydrogen sulfide (H2S), is essential for developing and implementing safety measures in the event of a release or spill. Heshka and Hager present a multidimensional gas chromatography method for analyzing dissolved hydrogen sulfide in crude oil samples. As far as we know, this is the only method that can accurately measure dissolved hydrogen sulfide in heavy crudes, without the use of sub-ambient cooling. In JoVE Behavior, Frisbee et al. present one of the most useful models for studying the pathophysiology of depression in rodents. This protocol uses a variety of mild stressors, and after a period of exposure to unpredictable chronic mild stress, rodents develop behaviours and cardiovascular alterations that are comparable to the symptoms of clinical depression. This approach allows for detailed studies of the pathological mechanisms of chronic stress, and can be used to test new therapies and interventions for chronic stress-induced depression. You've just had a sneak peek of the December 2015 issue of JoVE. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments © 2015 Journal of Visualized Experiments. Source


Chao W.,Massachusetts Eye and Ear Infirmary | Kolski-Andreaco A.,JoVE Content Production
Journal of Visualized Experiments | Year: 2015

In JoVE Environment, we've had a pretty warm summer in the northern hemisphere, so we can't help but think about all the greenhouse gases in our atmosphere that keep our planet nice and warm. These days, livestock are a major source of greenhouse gas emissions, especially methane. Livestock contribute anywhere from 7 to 18% of global emissions-depending on who you ask. Naturally, climate scientists are interested in controlling enteric methane from livestock. This requires accurate and precise measurement techniques, so Hristov et al. present a method using the Automated Head-Chamber System (AHCS), which monitors methane (CH4) and carbon dioxide (CO2) mass fluxes from the breath of ruminant animals (e.g., cattle). This system produces repeatable and accurate emission results, and can help efforts to curb greenhouse gas emissions. In JoVE Environment, we're also concerned about herbicide resistance in weeds, which poses a serious threat to food and fiber production. Plants can gain resistance to herbicides through genetic mutations or through enhanced activity of enzymes that metabolize and detoxify chemicals. In order to determine rates of herbicide metabolism in certain weeds, Ma et al. developed an excised leaf assay, which allows them to take experiments from the greenhouse into the lab so they can perform radiolabeled herbicide experiments more efficiently. As more and more plants become resistant to herbicides, this method will be useful for investigating the metabolic basis of herbicide resistance. In JoVE Bioengineering, one of the ultimate goals of tissue engineering is to regenerate large bone defects using synthetic scaffolds or templates. Most available scaffolds don't allow appreciable cell infiltration or distribution to achieve significant bone regeneration, so Oh et al. have developed a highly porous bone-like template with micro-channels and nanopores. Cells can be seeded into the biogenic templates through capillary action, and grow to confluence within days. This concept can help advance the repair of large bone defects. In JoVE Behavior, the human neuromuscular junction can be studied using a variety of noninvasive techniques, including electromyography (EMG), 3D motion capture, and transcranial magnetic stimulation. This month, Talkington et al. add the unique aspect of virtual reality to this test battery, and describe a customizable circuit that synchronizes data sampled from all of these techniques. You've just had a sneak peek of the September 2015 issue of JoVE. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments. © 2015 Journal of Visualized Experiments. Source


Chao W.,Massachusetts Eye and Ear Infirmary | Kolski-Andreaco A.,JoVE Content Production
Journal of Visualized Experiments | Year: 2015

Here's a look at what's coming up in the May 2015 issue of JoVE: The Journal of Visualized Experiments. In JoVE Environment, it's the middle of spring in the earth's Northern Hemisphere, so seeds are sprouting and buds are blooming. But for actively growing plants, especially those with no freezing tolerance, a cold snap can be deadly. A hard frost can dramatically alter natural ecosystems and devastate agriculture. Even more concerning, erratic weather patterns related to climate change can cause cold-susceptible plants to bud and bloom too early, then fall victim to a subsequent freeze. To protect plants from freezing, we need a better understanding of the freezing process. Wisniewski et al. describe a protocol to visualize this process using high-resolution infrared thermography (HRIT). Using this technology, scientists can determine how ice forms and propagates, and test various compounds that might alter the freezing process or increase freezing tolerance. In JoVE Chemistry, the principles of self-assembly have been used to engineer a variety of complex structures from biological and non-biological building blocks. This month, Wei et al. present detailed protocols for the self-assembly of single-stranded DNA tiles into complex 2D shapes with the tiles acting as molecular pixels on molecular canvases. These are visualized by atomic force microscopy. The modular nature of this approach allows it to be scalable, and the tiles can self-assemble into tubes and rectangles of varying sizes. This technique is also highly versatile-enabling the construction virtually any 2D shape. In JoVE Clinical & Translational Medicine, ischemic stroke happens when a blockage in an artery restricts blood flow to the brain, depriving it of oxygen and nutrients. When the blood returns, reperfusion can cause further damage by disrupting the blood-brain barrier and triggering inflammation and oxidative stress. There are many in vivo models of ischemia-reperfusion injury, and while all disease models have drawbacks, in vivo models tend to be technically challenging, with limited applicability for mechanistic studies. To help overcome some of these limitations, Alluri et al. present an in vitro model of ischemia-reperfusion, which can be used to study the molecular mechanisms of blood-brain barrier dysfunction and signs of oxidative stress. In JoVE Behavior, Fagot et al. study social cognition in monkeys. In this protocol, monkeys living in social groups have free access to multiple test units. When a monkey enters a testing chamber, and reaches through the hand port, a computer recognizes the monkey through its radio frequency ID (RFID) chip and starts the experiment A touch screen displays the stimulus and a food dispenser delivers the reward. Over several years, this procedure has been shown enhance motivation in the subjects and favor complex learning-particularly the social aspects. You've just had a sneak peek of the May 2015 issue of JoVE. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments. © 2015 Journal of Visualized Experiments. Source

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