MedWorm provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest medical blog items that have been tagged with 'fluorescence'. Sat, 03 Sep 2011 02:36:18 +0100 http://www.medworm.com/index.php?rid=5050575&cid=t_100917_87_f&fid=39187&url=http%3A%2F%2Fgetbetterhealth.com%2Fnew-contrast-agent-provides-better-in-vivo-imaging-of-bacteria%2F2011.07.22 A new contrast agent based on maltodextrin has been developed at Georgia Tech that can provide in vivo imaging of bacteria with a sensitivity two orders of magnitude greater than previously achieved. Unlike most previous methods, the new probes are able to enter bacterial cells by pretending to be food, while avoiding being ingested by the mammalian cells. From Georgia Tech: Maltodextrin-based imaging probes consist of a fluorescent dye linked to maltohexaose, which is a major source of glucose for bacteria. The probes deliver the contrast agent into bacteria through the organism’s maltodextrin transporter, which only exists in bacterial cells and not mammalian cells. In experiments using a rat model, the researchers found that (more…) *This blog post was originally publi... Better Health blogs http://www.medworm.com/rss/comments.php?id=5050575 Fri, 22 Jul 2011 12:00:13 +0100 5050575 http://www.medworm.com/index.php?rid=4482875&cid=t_100917_122_f&fid=35068&url=http%3A%2F%2Fbrainwindows.wordpress.com%2F2011%2F02%2F16%2Frapid-warping-of-two-photon-illumination-wavefronts%2F A short paper in Optics Express looks interesting.  In A high speed wavefront determination method based on spatial frequency modulations for focusing light through random scattering media, Meng Cui presents a method for rapidly determining the optimal wavefront to ‘cancel out’ the scattering when 785nm light passes through turbid media.  In his example, a glass diffuser was used, but the clear goal for this work is to replace the glass with a brain. To understand why this is so important for in vivo two-photon imaging, let’s review how 2-p imaging works. Light from a laser is focused to a point and swept across the field in a raster. The resulting fluorescence is of a different wavelength and can thus be filtered out from the excitation light. For each voxel, all the ... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=4482875 Wed, 16 Feb 2011 13:51:15 +0100 4482875 http://www.medworm.com/index.php?rid=4151976&cid=t_100917_113_f&fid=39278&url=http%3A%2F%2Fblogsite.mdbuyline.com%2F%3Fp%3D86 How do you visualize a tumor the size of a pinhead or a critical structure without radiation or patient contact?  Easy, in theory; you make it glow.  Near-infrared (NIR) fluorescence first appeared in the laboratory, but it has now become an effective, real-time intraoperative instrument.  Dr. John Frangioni, MD, PhD, associate professor of medicine and radiology at Harvard Medical School in Boston, MA, is a leading scientist whose lab is focused on developing NIR technology.  He explained the technology’s applications and stated, “Near-infrared technology is a platform that can be used with any type of surgery and is limited only by the contrast agents used.  In the morning, it could be used for cardiac surgery; in the afternoon, cancer surgery.”  NIR fluorescence consists of ... MD Buyline blogs http://www.medworm.com/rss/comments.php?id=4151976 Wed, 10 Nov 2010 14:27:50 +0100 4151976 http://www.medworm.com/index.php?rid=3973009&cid=t_100917_122_f&fid=35068&url=http%3A%2F%2Fbrainwindows.wordpress.com%2F2010%2F09%2F15%2Fupdate-diadem-final-results%2F The DIADEM automated neuronal reconstruction contest has finished.  Accurate, fast, and high-resolution automated neuron reconstruction is of vital importance to cracking the mystery of how neural circuits perform. Even with perfect knowledge of the firing patterns of every cell in a circuit, our understanding of how these patterns are produced and how the information is processed would be quite limited.  True understanding requires knowledge of the precise wiring diagram.  This prize is a good first step towards bringing awareness of this tricky problem to the world’s best computer scientists. $75,000 in prize money was to go to the group that was able to produce high-quality reconstructions of neuronal structures at least 20x faster than by-hand reconstructions.  In the finals... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=3973009 Wed, 15 Sep 2010 19:23:46 +0100 3973009 http://www.medworm.com/index.php?rid=3848953&cid=t_100917_122_f&fid=35068&url=http%3A%2F%2Fbrainwindows.wordpress.com%2F2010%2F08%2F09%2Fcameleon-nanos-high-affinity-gecis%2F Takeharu Nagai’s lab has published in Nature Methods, Spontaneous network activity visualized by ultrasensitive Ca2+ indicators, yellow Cameleon-Nano, demonstrating a new set of calcium indicators based on yellow cameleon. Back when he was still Take-san, Take’s ability to churn out and manually screen hundreds of cameleon variants was impressive and inspiring. With high-throughput GECI pipelines now ramping up at Janelia, the idea of laboriously screening 200 variations on a theme (be it cameleons or GluSnFRs), seems a bit archaic. However, this paper is a good example of the progress that can still be made by understanding the needed sensor parameters and fiddling with the primary amino acid structure in a relatively low-throughput way. Take-sensei’s results are another... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=3848953 Tue, 10 Aug 2010 03:52:04 +0100 3848953 http://www.medworm.com/index.php?rid=3362486&cid=t_100917_122_f&fid=35068&url=http%3A%2F%2Fwww.molecularbrain.com%2Fcontent%2Fdownload%2Fsupplementary%2F1756-6606-3-5-s3.mov Atsushi Miyawaki’s lab has developed a series of neat tools for visualizing cell cycle progress. For zebrafish, the zFucci system consists of two fluorescent proteins, mKO2 and mAG, that are fused to Cdt1 and geminin genes.  Cell cycle- regulated proteolysis of these fusion proteins causes each cell to display orange fluorescence in G1 phase nuclei and green fluorescence in both the nucleus and cytoplasm of S/G2/M phase cells. Video of cell cycle transitions in culture. Click for the video. The last time I saw Atsushi give a talk, he showed an incredible time lapse video from the zebrafish cleavage stage that I haven’t been able to find online.  However, here is a video from later in development of the zebrafish that is still pretty remarkable. Development of a zebrafish visu... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=3362486 Sat, 13 Mar 2010 16:08:39 +0100 3362486 http://www.medworm.com/index.php?rid=2984880&cid=t_100917_113_f&fid=34831&url=http%3A%2F%2Ffeedproxy.google.com%2F%7Er%2FDocinthemachine%2F%7E5%2FGVbZRtnVvWE%2Fditmnov2009ott.mp3 I have been getting great feedback on my DITM medical technology podcast which starts the podcast series I’ll be doing regularly.  Several people wrote to ask if I could post a version with just the interview since they loved it so much and wanted to share that segment.  The original podcast starts with FDA approvals then has an interview with Sony Exec Bob Ott on the future of video technology in entertainment and medicine that we did a the NAB broadcast meeting in Vegas. Here’s an edit version with just the interview enjoy and share with your friends!   addthis_url = 'http%3A%2F%2Fdocinthemachine.com%2F2009%2F11%2F12%2Fsonypodcast%2F'; addthis_title = 'DITM+Podcast+on+Future+of+Video+for+Entertainment+%26%23038%3B+Medicine+With+Sony+Exec'; addthis_pub = ''; (Source... docinthemachine blogs http://www.medworm.com/rss/comments.php?id=2984880 Thu, 12 Nov 2009 04:15:36 +0100 2984880 http://www.medworm.com/index.php?rid=2977425&cid=t_100917_122_f&fid=35068&url=http%3A%2F%2Fbrainwindows.wordpress.com%2F2009%2F11%2F09%2Fthree-cheers-for-gcamp%2F Three papers are out online in Nature Methods that show big improvements in calcium imaging with genetically encoded sensors.  They are are based on the fluorescence intensity indicator, GCaMP.   GCaMP, first developed by Junichi Nakai, consists of a GFP that has been circularly permuted so that the N and C termini are fused and new termini are made in the middle of the protein.  Fused to one terminus is calmodulin and the other is a peptide, M13, that calmodulin (CaM) binds to in the presence of calcium. The name is supposed to look like GFP with a CaM inserted into it, G-CaM-P.  Normally the GFP is dim, as there is a hole from the outside of its barrel into the chromophore.  Upon binding calcium, this hole is plugged and fluorescence increases. The first paper, A genetically encod... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=2977425 Mon, 09 Nov 2009 23:54:11 +0100 2977425 http://www.medworm.com/index.php?rid=2857491&cid=t_100917_122_f&fid=35068&url=http%3A%2F%2Fbrainwindows.wordpress.com%2F2009%2F10%2F02%2Fautomated-roi-analysis-for-calcium-imaging%2F One of the most time consuming and frustrating tasks associated with fluorescence imaging in the brain is picking out your regions of interest.  Which pixels do you include in as part of the cell and which are part of the surrounding neuropil?  Often, the answer is not obvious, and even with painstaking selections you can make errors.  Eran Mukamel et. al, from Mark Schnitzer’s lab just published this Neurotechnique Automated Analysis of Cellular Signals from Large-Scale Calcium Imaging Data that aims to simplify and improve the results of ROI selection.  The authors used a multistage approach to identify and quantify the calcium-dependent fluorescence changes of imaged neurons. First, they used principal component analysis to identify the components of the image that were likel... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=2857491 Fri, 02 Oct 2009 23:04:54 +0100 2857491 http://www.medworm.com/index.php?rid=2725213&cid=t_100917_136_f&fid=37846&url=http%3A%2F%2Fhealthinfoispower.wordpress.com%2F2009%2F08%2F21%2Fua-research-team-designing-holographic-imaging-system-for-ovarian-cancer%2F University of Arizona researchers Jennifer Barton and Ray Kostuk have received a five-year, $2.4 million grant from the National Institutes of Health to build the instrument that they hope will one day be used to monitor women at high risk for ovarian cancer. Two University of Arizona [UA] researchers have formed a research team to [...] (Source: Libby's H*O*P*E*) Libby's H*O*P*E* blogs http://www.medworm.com/rss/comments.php?id=2725213 Sat, 22 Aug 2009 02:26:23 +0100 2725213 http://www.medworm.com/index.php?rid=2212648&cid=t_100917_136_f&fid=37846&url=http%3A%2F%2Fhealthinfoispower.wordpress.com%2F2009%2F02%2F24%2Feuropean-researchers-find-estrogen-receptor-gene-amplification-occurs-rarely-in-ovarian-cancer%2F “… ESR1 [gene] amplification is an uncommon mechanism for estrogen receptor overexpression in ovarian cancer occurring in about 2.1% of the total number of ovarian cancers. In general, this frequency parallels the fraction of ovarian cancers reported to show complete response to antiestrogenic [anti-hormonal] therapies. Given the strong predictive power of ESR1 [gene] amplification for [...] (Source: Libby's H*O*P*E*) Libby's H*O*P*E* blogs http://www.medworm.com/rss/comments.php?id=2212648 Tue, 24 Feb 2009 23:03:08 +0100 2212648 http://www.medworm.com/index.php?rid=1964123&cid=t_100917_122_f&fid=35068&url=http%3A%2F%2Fbrainwindows.wordpress.com%2F2008%2F11%2F15%2Fraw-data-vesicular-release-from-astrocytes%2F When I was working on my Ph.D. thesis, I was trying to find some biological question to definitively answer with GluSnFR, my glutamate sensitive fluorescent reporter. One possibility was the study of glutamate release from astrocytes.  Around that time, 2003/2004, there was increasing evidence that glutamate was not just scavenged by astrocytes, but was also released from astrocytic vesicles. It released in response to calcium elevations within the cell.  Existing methods for measuring this release were somewhat crude, so it seemed a great test system for GluSnFR.   Unfortunately, since there seemed to be no specialized areas on the astrocyte where the vesicles fused, and the release rate was relatively slow, we were unable to detect glutamate release with GluSnFR. I thought this might ... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=1964123 Sat, 15 Nov 2008 23:21:38 +0100 1964123 http://www.medworm.com/index.php?rid=1596486&cid=t_100917_122_f&fid=35068&url=http%3A%2F%2Fbrainwindows.wordpress.com%2F2008%2F07%2F08%2Fvoltage-sensitive-imaging-powering-up%2F I’m starting to come around on voltage imaging. I haven’t been a fan of it for a number of reasons. The response sizes suck.  Classic dyes and genetically encoded systems get a few percent fluorescence change at best.  The response speeds suck. Measuring continuous current injections from -100mV to +150mV is not very interesting.  Action potentials are interesting.  But they are fast. Toxicity. The dyes kill neurons, or strongly perturb their electrical properties. OK, voltage-sensitive imaging isn’t totally useless, for example see Carl Petersen’s recent paper on Spatiotemporal Dynamics of Cortical Sensorimotor Integration in Behaving Mice (2007). But if the above problems could be solved, then voltage sensitive imaging would be a strong competitor to calciu... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=1596486 Tue, 08 Jul 2008 22:29:44 +0100 1596486 http://www.medworm.com/index.php?rid=845697&cid=t_100917_113_f&fid=34831&url=http%3A%2F%2Ffeeds.feedburner.com%2F%7Er%2FDocinthemachine%2F%7E3%2F152839406%2F I previously wrote about the upcoming National Geographic Special Inside the Living Body and my work featured in the special. I was delighted when the producers of 20/20 called to request an interview with me on my research featured on the show and my vision of the future technological transformation of medicine. Bob Brown was interested in coming to interview me. They have already posted a description of the upcoming interviewand a summary of the show. They call it an “Unprecedented Journey Inside the Living Body- ‘We’re Seeing Things That We Had Never Seen Before,’ Says Scientist (that’s me). On their website they write: Recent technological advances have allowed for such dramatic and amazing views of the inside of our bodies that watching the footage can fe... docinthemachine blogs http://www.medworm.com/rss/comments.php?id=845697 Thu, 06 Sep 2007 06:45:16 +0100 845697 http://www.medworm.com/index.php?rid=485103&cid=t_100917_113_f&fid=34831&url=http%3A%2F%2Fdocinthemachine.com%2F2007%2F03%2F21%2Fglomosk%2F The BBC is reoprting that a new geneticaly medified mosquito has been created that is relatively reistant to malaria.  The study publsihed in PNAS reports The approach exploits the fact that the health of infected mosquitoes is itself compromised by the parasite they spread. Insects that cannot be invaded by the parasite are therefore likely to be fitter and out-compete their disease-carrying counterparts. BBC says; The organism is passed to humans through the bite of the Anopheles mosquito. Each year it makes 300 million people ill and causes a million deaths worldwide.   Some 90% of cases are in sub-Saharan Africa, where a child dies of malaria every 30 seconds. Before you spill all of your quinine out, the malaria variation tested was a rdent one and the researchers predict tit will ... docinthemachine blogs http://www.medworm.com/rss/comments.php?id=485103 Wed, 21 Mar 2007 04:36:40 +0100 485103 http://www.medworm.com/index.php?rid=471285&cid=t_100917_113_f&fid=34831&url=http%3A%2F%2Fdocinthemachine.com%2F2007%2F03%2F13%2Fgr325-3%2F Grand Rounds 3.25 is up over at Scienceroll.  A gret blog I have mentioned before it is run by Bertalan Meskó, a Hungarian Medical Student wit a passion for genetics.  Definitely worth checking out there are about 60 posts but excellently organized in categories to make the reading clear and quick.  A nice variety. I am honored that he chose two submissions from docinthemachine (one I submitted and one submitted by somemone else!).  There are links to my posts on : docinthemachine’s first podcast on the coming technological revolution in surgery (in a new web 2.0 section of grand rounds )and also on new regulations to spread information and increase post marketing surveillance of drugs from the FDA (Source: docinthemachine) docinthemachine blogs http://www.medworm.com/rss/comments.php?id=471285 Tue, 13 Mar 2007 12:53:59 +0100 471285