Scientists at National Institute of Standards and Technology (NIST) are using nanopores (membrane gates less than 2 nanometers wide) to identify the type of molecules that are passing through the openings. The method measures the electrical change of the ionic fluid that is pumped through the nanopores along with the molecules in question. Because each molecule reduces the amount of the ionic fluid passing through based on its size and shape, the electrical measurements reveal which molecule is traversing the gate. Once developed, nanopore based technology may allow for all kinds of new diagnostic devices that can identify pathogens, proteins, and other reagents.
Nanopores are not new themselves; for more than a decade, scientists have sought to use a nanopore-based electrical detector to characterize single-stranded DNA for genetic sequencing applications. More recently, NIST scientists turned their attention to using nanopores to identify, quantify and characterize each of the more than 20,000 proteins the body produces—a capability that would provide a snapshot of a patient’s overall health at a given moment. But while nanopores permit molecules to enter into them one at a time, determining what specific individual molecule has just passed through has not been easy.
To address this problem, members of the NIST team that previously developed a method to distinguish both the size and concentration of each type of molecule the nanopore admits have now answered the question of just how these single molecules interact with the nanopore. Their new theoretical model describes the physics and chemistry of how the nanopore, in effect, parses a molecule, an understanding that will advance the use of nanopores in the medical field.
Press release: NIST Team Advances in Translating Language of Nanopores …
Abstract in PNAS: Theory for polymer analysis using nanopore-based single-molecule mass spectrometry
Imagine having a metal detector handy when you, as an emergency physician, have an unconscious patient come in and you need to know whether he has an implant. Well, you can sort of do it now with the Metal Detector app for Android phones that have magnetometers (ex: HTC T-Mobile G1). It won’t do quite yet, as the magnetometer that’s typically used as a compass isn’t strong enough to detect keys more than an a couple inches away. But as a preview, we can imagine having one of these apps handy on a future, more magnetically endowed, smart phone.
A collaboration between German, Swiss, and Japanese scientists has developed a method of using genetically encoded voltage-gated calcium channels to visualize live activity of neurons within the brains of mice. The scientists accomplished this by introducing a virus carrying a gene that coded for a fluorescent protein, which in turn was activated and visible during electrical brain activity.
From a Max Planck Society press release:
Neurons communicate with one another via so-called action potentials. During an action potential, voltage-gated calcium channels are opened resulting in rapid calcium ion influx. Because of this tight coupling, fluorescent calcium indicator proteins can visualize action potentials. These proteins have two fluorescent subunits, one of which radiates yellow light and the other blue. When the proteins bind calcium, the proportion of yellow to blue light changes. Colour variation from blue light towards yellow thus reports different calcium levels – which is why the protein has been dubbed a "cameleon".
With the cameleon protein YC3.60, a fairly new variant, the scientists succeeded in recording the reaction of nerve cells to sensory stimuli in the intact brain of mice: every time the whiskers were deflected by a puff of air, there was a change of colour in the cameleon proteins in the nerve cells of the sensory areas of the cortex. It could therefore be deduced that the affected cells had reacted to the stimulus with action potentials.
Cameleon proteins could therefore revolutionize the study of electrical activity in the brain. To date, the only way scientists could do this is by inserting electrodes into the nerve tissue or the cells. This electrode technique is blind to cell identity and it damages the tissue. By contrast, the cameleon protein’s colour changes can be observed in a much less invasive procedure using glass fibres as light conductors or with the help of modern fluorescence microscopes – known as two-photon laser-scanning microscopes. Moreover, cameleon proteins can be formed by cells themselves provided a corresponding section of DNA has been inserted into the genome in advance. In the experiments conducted by the scientists, viruses served as the vehicle for smuggling the genetic information for the cameleon proteins into the nerve cells.
In two earlier studies, an international team of scientists headed by Mazahir Hasan were the first to demonstrate that similar genetic probes can successfully detect natural sensation (such as smell and touch) in the mammalian brain in the form of unique activity patterns (Hasan et al., 2004) and, more importantly, with single-cell, single-action-potential resolution (Wallace et al., 2008). In the current study, they have reached yet another major milestone as they demonstrate that the cameleon YC3.60 can be used to record activity from a large number of nerve cells during behaviour in freely moving mice. Additionally, it is well suited for recording activity from the same nerve cells in the same animals over a long time period and should help scientists to understand how network activity patterns form to code for different experiences and animal behaviour.
Press release: Blinking neurons give thoughts away…
Abstract in Frontiers in Neural Circuits: Optical recording of neuronal activity with a genetically-encoded calcium indicator in anesthetized and freely moving mice
The world’s first remote robotic heart rhythm treatment procedure was conducted at the University Hospitals of Leicester. It was performed using the Catheter Robotics Remote Catheter Manipulation System. A 70 year old man with atrial fibrillation had a catheter ablation controlled by a robotic arm, while the cardiologist – sitting in a separate room – used remote control to steer the catheter endovascularly into the heart to correct faulty tissue fibers. Although it was controlled from an adjacent room in this case, the fully remote-controlled robot could be controlled from anywhere in the world. The procedure was successfully completed in one hour and the patient is supposedly doing well.
Technology demo video and links below the fold:
News story @ UK Daily Mail: British man has world’s first heart operation using remote control-operated robotic arm…
Scientists at National Institute of Standards and Technology (NIST) are using nanopores (membrane gates less than 2 nanometers wide) to identify the type of molecules that are passing through the openings. The method measures the electrical change of the ionic fluid that is pumped through the nanopores along with the molecules in question. Because each molecule reduces the amount of the ionic fluid passing through based on its size and shape, the electrical measurements reveal which molecule is traversing the gate. Once developed, nanopore based technology may allow for all kinds of new diagnostic devices that can identify pathogens, proteins, and other reagents. 
