Posts tagged medicine
Articles and news from the latest research reports.
Microrobots armed with new force-sensing system to probe cells
Inexpensive microrobots capable of probing and manipulating individual cells and tissue for biological research and medical applications are closer to reality with the design of a system that senses the minute forces exerted by a robot’s tiny probe.
Microrobots small enough to interact with cells already exist. However, there is no easy, inexpensive way to measure the small forces applied to cells by the robots. Measuring these microforces is essential to precisely control the bots and to use them to study cells.
"What is needed is a useful tool biologists can use every day and at low cost," said David Cappelleri, an assistant professor of mechanical engineering at Purdue University.
Now researchers have designed and built a “vision-based micro force sensor end-effector,” which is attached to the microrobots like a tiny proboscis. A camera is used to measure the probe’s displacement while it pushes against cells, allowing a simple calculation that reveals the force applied.
The approach could make it possible to easily measure the “micronewtons” of force applied at the cellular level. Such a tool is needed to better study cells and to understand how they interact with microforces. The forces can be used to transform cells into specific cell lines, including stem cells for research and medical applications. The measurement of microforces also can be used to study how cells respond to certain medications and to diagnose disease.
"You want a device that is low-cost, that can measure micronewton-level forces and that can be easily integrated into standard experimental test beds," Cappelleri said.
Microrobots used in research are controlled with magnetic fields to guide them into position.
"But this is the first one with a truly functional end effector to measure microforces," he said.
Current methods for measuring the forces applied by microrobots are impractical and expensive, requiring an atomic force microscope or cumbersome sensors with complex designs that are difficult to manufacture. The new system records the probe’s displacement with a camera as it pushes against a cell or tissue. Researchers already know the stiffness of the probe. When combined with displacement, a simple calculation reveals the force applied.
Findings were detailed in a research paper presented during the International Conference on Intelligent Robots and Systems in September. The paper was authored by postdoctoral research associate Wuming Jing and Cappelleri.
The new system combined with the microrobot is about 700 microns square, and the researchers are working to create versions about 500 microns square. To put this scale into perspective, the mini-machine is about one-half the size of the “E” in “One Cent” on a U.S. penny.
"We are currently working on scaling it down," he said.
Future research also may focus on automating the microrobots.
New front in war on Alzheimer’s, other protein-folding diseases
A surprise discovery that overturns decades of thinking about how the body fixes proteins that come unraveled greatly expands opportunities for therapies to prevent diseases such as Alzheimer’s and Parkinson’s, which have been linked to the accumulation of improperly folded proteins in the brain.
“This finding provides a whole other outlook on protein-folding diseases; a new way to go after them,” said Andrew Dillin, the Thomas and Stacey Siebel Distinguished Chair of Stem Cell Research in the Department of Molecular and Cell Biology and Howard Hughes Medical Institute investigator at the University of California, Berkeley.
Dillin, UC Berkeley postdoctoral fellows Nathan A. Baird and Peter M. Douglas and their colleagues at the University of Michigan, The Scripps Research Institute and Genentech Inc., will publish their results in the Oct. 17 issue of the journal Science.
Cells put a lot of effort into preventing proteins – which are like a string of beads arranged in a precise three-dimensional shape – from unraveling, since a protein’s activity as an enzyme or structural component depends on being properly shaped and folded. There are at least 350 separate molecular chaperones constantly patrolling the cell to refold misfolded proteins. Heat is one of the major threats to proteins, as can be demonstrated when frying an egg – the clear white albumen turns opaque as the proteins unfold and then tangle like spaghetti.
Heat shock
For 35 years, researchers have worked under the assumption that when cells undergo heat shock, as with a fever, they produce a protein that triggers a cascade of events that field even more chaperones to refold unraveling proteins that could kill the cell. The protein, HSF-1 (heat shock factor-1), does this by binding to promoters upstream of the 350-plus chaperone genes, upping the genes’ activity and launching the army of chaperones, which originally were called “heat shock proteins.”
Injecting animals with HSF-1 has been shown not only to increase their tolerance of heat stress, but to increase lifespan.
Because an accumulation of misfolded proteins has been implicated in aging and in neurodegenerative diseases such as Alzheimer’s, Parkinson’s and Huntington’s diseases, scientists have sought ways to artificially boost HSF-1 in order to reduce the protein plaques and tangles that eventually kill brain cells. To date, such boosters have extended lifespan in lab animals, including mice, but greatly increased the incidence of cancer.
Dillin’s team found in experiments on the nematode worm C. elegans that HSF-1 does a whole lot more than trigger release of chaperones. An equal if not more important function is to stabilize the cell’s cytoskeleton, which is the highway that transports essential supplies – healing chaperones included – around the cell.
“We are suggesting that, rather than making more of HSF-1 to prevent diseases like Huntington’s, we should be looking for ways to make the actin cytoskeleton better,” Dillin said. Such tactics might avoid the carcinogenic side effects of upping HSF-1.
Dillin is codirector of the Paul F. Glenn Center for Aging Research, a new collaboration between UC Berkeley and UC San Francisco supported by the Glenn Foundation for Medical Research. Center investigators will study the many ways that proteins malfunction within cells, ideally paving the way for novel treatments for neurodegenerative diseases.
A cell at war
Dillin compares a cell experiencing heat shock to a country under attack. In a war, an aggressor first cuts off all communications, such as roads, train and bridges, which prevents the doctors from treating the wounded. Similarly, heat shock disrupts the cytoskeletal highway, preventing the chaperone “doctors” from reaching the patients, the misfolded proteins.
“We think HSF-1 not only makes more chaperones, more doctors, but also insures that the roadways stay intact to keep everything functional and make sure the chaperones can get to the sick and wounded warriors,” he said.
The researchers found specifically that HSF-1 up-regulates another gene, pat-10, that produces a protein that stabilizes actin, the building blocks of the cytoskeleton.
By boosting pat-10 activity, they were able to cure worms that had been altered to express the Huntington’s disease gene, and also extend the lifespan of normal worms.
Dillin suspects that HSF-1’s main function is, in fact, to protect the actin cytoskeleton. He and his team mutated HSF-1 so that it no longer boosted chaperones, demonstrating, he said, that “you can survive heat shock with the normal level of heat shock proteins, as long as you make your cytoskeleton work better.”
He noted that the team’s results – that boosting chaperones is not essential to surviving heat stress – were so contradictory to current thinking that “I made my post-docs’ lives hell for three years” insisting on more experiments to rule out errors. Yet, when Dillin presented the results recently to members of the protein-folding community, he said the first reaction of many was, “That makes perfect sense.”
Set of molecules found to link insulin resistance in the brain to diabetes
A key mechanism behind diabetes may start in the brain, with early signs of the disease detectable through rising levels of molecules not previously linked to insulin signaling, according to a study led by researchers at the Icahn School of Medicine at Mount Sinai published today in the journal Cell Metabolism.
(Image: Shutterstock)
The Nobel Assembly at Karolinska Institutet has decided to award the 2014 Nobel Prize in Physiology or Medicine with one half to John O´Keefe and the other half jointly to May-Britt Moser and Edvard I. Moser for their discoveries of cells that constitute a positioning system in the brain.
How do we know where we are? How can we find the way from one place to another? And how can we store this information in such a way that we can immediately find the way the next time we trace the same path? This year´s Nobel Laureates have discovered a positioning system, an “inner GPS” in the brain that makes it possible to orient ourselves in space, demonstrating a cellular basis for higher cognitive function.
In 1971, John O´Keefe discovered the first component of this positioning system. He found that a type of nerve cell in an area of the brain called the hippocampus that was always activated when a rat was at a certain place in a room. Other nerve cells were activated when the rat was at other places. O´Keefe concluded that these “place cells” formed a map of the room.
More than three decades later, in 2005, May-Britt and Edvard Moser discovered another key component of the brain’s positioning system. They identified another type of nerve cell, which they called “grid cells”, that generate a coordinate system and allow for precise positioning and pathfinding. Their subsequent research showed how place and grid cells make it possible to determine position and to navigate.
The discoveries of John O´Keefe, May-Britt Moser and Edvard Moser have solved a problem that has occupied philosophers and scientists for centuries – how does the brain create a map of the space surrounding us and how can we navigate our way through a complex environment?
How do we experience our environment?
The sense of place and the ability to navigate are fundamental to our existence. The sense of place gives a perception of position in the environment. During navigation, it is interlinked with a sense of distance that is based on motion and knowledge of previous positions.
Questions about place and navigation have engaged philosophers and scientists for a long time. More than 200 years ago, the German philosopher Immanuel Kant argued that some mental abilities exist as a priori knowledge, independent of experience. He considered the concept of space as an inbuilt principle of the mind, one through which the world is and must be perceived. With the advent of behavioural psychology in the mid-20th century, these questions could be addressed experimentally. When Edward Tolman examined rats moving through labyrinths, he found that they could learn how to navigate, and proposed that a “cognitive map” formed in the brain allowed them to find their way. But questions still lingered - how would such a map be represented in the brain?
John O´Keefe and the place in space
John O´Keefe was fascinated by the problem of how the brain controls behaviour and decided, in the late 1960s, to attack this question with neurophysiological methods. When recording signals from individual nerve cells in a part of the brain called the hippocampus, in rats moving freely in a room, O’Keefe discovered that certain nerve cells were activated when the animal assumed a particular place in the environment (Figure 1). He could demonstrate that these “place cells” were not merely registering visual input, but were building up an inner map of the environment. O’Keefe concluded that the hippocampus generates numerous maps, represented by the collective activity of place cells that are activated in different environments. Therefore, the memory of an environment can be stored as a specific combination of place cell activities in the hippocampus.
May-Britt and Edvard Moser find the coordinates
May-Britt and Edvard Moser were mapping the connections to the hippocampus in rats moving in a room when they discovered an astonishing pattern of activity in a nearby part of the brain called the entorhinal cortex. Here, certain cells were activated when the rat passed multiple locations arranged in a hexagonal grid (Figure 2). Each of these cells was activated in a unique spatial pattern and collectively these “grid cells” constitute a coordinate system that allows for spatial navigation. Together with other cells of the entorhinal cortex that recognize the direction of the head and the border of the room, they form circuits with the place cells in the hippocampus. This circuitry constitutes a comprehensive positioning system, an inner GPS, in the brain (Figure 3).
A place for maps in the human brain
Recent investigations with brain imaging techniques, as well as studies of patients undergoing neurosurgery, have provided evidence that place and grid cells exist also in humans. In patients with Alzheimer´s disease, the hippocampus and entorhinal cortex are frequently affected at an early stage, and these individuals often lose their way and cannot recognize the environment. Knowledge about the brain´s positioning system may, therefore, help us understand the mechanism underpinning the devastating spatial memory loss that affects people with this disease.
The discovery of the brain’s positioning system represents a paradigm shift in our understanding of how ensembles of specialized cells work together to execute higher cognitive functions. It has opened new avenues for understanding other cognitive processes, such as memory, thinking and planning.
(Source: nobelprize.org)
Applying Proteomics to Parkinson’s
Scientists studying two genes that are mutated in an early-onset form of Parkinson’s disease have deciphered how normal versions of these genes collaborate to help rid cells of damaged mitochondria. Mitochondria are the cell’s primary energy source, and maintaining their health is critical for cellular function. Mitochondrial dysfunction may underlie multiple neurodegenerative diseases, including Parkinson’s.
(Image caption: PARKIN (green) is localized on damaged mitochondria. Image: Harper Lab)
In their analysis published in Molecular Cell, Harvard Medical School researchers used powerful quantitative mass spectrometry and live-cell imaging approaches to elucidate a multistep mechanism by which the two proteins mutated in Parkinson’s disease—PINK1 and PARKIN—mark mitochondria as damaged by attaching chains of a small protein called ubiquitin. This work paves the way for a deeper understanding of what molecular steps are defective when these proteins are mutated in patients with Parkinson’s disease.
“The PINK1-PARKIN pathway has been studied for many years, yet its mechanisms weren’t clearly defined,” said Wade Harper, Bert and Natalie Vallee Professor of Molecular Pathology in the Department of Cell Biology at HMS and senior author of the paper. “Combining imaging and advanced mass spectrometry approaches has allowed us for the first time to determine with molecular precision the biochemical output of the PINK1-PARKIN pathway in living cells.”
One hypothesis about the origin of Parkinson’s disease suggests that neurons place high energy demands on their mitochondria. When mitochondria become damaged and their energy production falls, they must be cleared away; if not, cell death results when the damaged mitochondria create harmful chemicals called reactive oxygen species.
People who have certain early-onset mutations in PINK1 or PARKIN genes may live normal lives until they enter their 30s when movement disorders begin to appear, reflecting the loss of neurons that make the neurotransmitter dopamine. These neurons seem to be the cells that are the most sensitive to an inability to remove damaged mitochondria.
Only in the last few years have scientists understood that the enzymes PARKIN and PINK1 work together to remove damaged mitochondria. The PINK1 kinase, an enzyme that transfers phosphate to other proteins, is activated specifically on damaged mitochondria where it then functions to promote accumulation of PARKIN on the mitochondrial surface. Once there, PARKIN—a ubiquitin ligase— marks numerous proteins on the surface of the mitochondria with chains of ubiquitin, which in turn target the damaged mitochondria for removal from the cell.
In their new work, Harper’s team identifies a multistep “feed-forward” mechanism that involves intertwined ubiquitylation and phosphorylation in a sequence of reactions that successively build on one another. To the authors’ knowledge, this is the first report of a feed-forward mechanism of this type.
The team, led by postdoctoral fellow Alban Ordureau, found that PINK1 actually has two functions in a multistep pathway. First, PINK1 phosphorylates PARKIN, greatly stimulating its ability to attach ubiquitin to mitochondrial substrates. Second, PINK1 phosphorylates ubiquitin chains that PARKIN has just built. Unexpectedly, these phosphorylated ubiquitin chains then bind tightly to activated PARKIN, thereby facilitating its retention on the mitochondrial surface and furthering ubiquitin chain assembly through a feed-forward mechanism. Eventually these chains become so dense that the damaged mitochondria are marked for degradation.
“Our finding that PARKIN binds phosphorylated-ubiquitin chains as its mechanism of retention on damaged mitochondria was completely unexpected,” Harper said. “Ubiquitin has been studied for almost 40 years, but only recently has regulation of ubiquitin by phosphorylation emerged as a major focus for the field.”
Methods employed in this study have their origins in prior work of Steven Gygi, HMS professor of cell biology and a co-author of the paper, who developed ways to quantify ubiquitin chains more than a decade ago. Harper says there is “enormous potential in the application of these approaches to understand how defects in the ubiquitin system lead to disease.”
The team also included Brenda Schulman, a Howard Hughes Medical Institute investigator, the co-director of the Cancer Genetics, Biochemistry and Cell Biology Program at St. Jude Children’s Research Hospital and a leading expert on ubiquitin biochemistry.
“This is a very intricate pathway,” Ordureau said. “We were surprised by our findings at every step.”
(Source: hms.harvard.edu)
Researchers Identify New Pathway Linking the Brain to High Blood Pressure
New research by scientists at the University of Maryland School of Medicine (UM SOM) and the Ottawa Heart Institute has uncovered a new pathway by which the brain uses an unusual steroid to control blood pressure. The study, which also suggests new approaches for treating high blood pressure and heart failure, appears today in the journal Public Library of Science (PLOS) One.
“This research gives us an entirely new way of understanding how the brain and the cardiovascular system work together,” said Dr. John Hamlyn, professor of physiology at the University of Maryland School of Medicine, one of the principal authors. “It opens a new and exciting way for us to work on innovative treatment approaches that could one day help patients.”
For decades, researchers have known that the brain controls the diameter of the peripheral arteries via the nervous system. Electrical impulses from the brain travel to the arteries via a network of nerves known as the sympathetic nervous system. This system is essential for daily life, but is often chronically overactive in high blood pressure and heart failure. In fact, many drugs that help with hypertension and heart failure work by decreasing both acute and chronic activity in the sympathetic nervous system. However, these drugs often have serious side effects, such as fatigue, dizziness and erectile dysfunction. “These drawbacks have led to the search for novel ways to inhibit the sympathetic nervous system while causing fewer problems for hypertension and heart failure patients,” says Dr. Frans Leenen, director of hypertension at the Ottawa Heart Institute, and a principal author of the study.
Working with an animal model of hypertension, Dr. Hamlyn and Dr. Mordecai Blaustein, professor of physiology and medicine at the UM SOM, and their research partner, Dr. Leenen, found a new link between the brain and increased blood pressure, namely, a little-known steroid called ouabain (pronounced WAH-bane). Ouabain was discovered in human blood more than 20 years ago by Dr. Hamlyn and Dr. Blaustein, along with scientists at the Upjohn Company. The new study is the first to identify the particular pathway that connects the brain to ouabain’s effects on proteins that regulate arterial calcium and contraction. Through this mechanism, ouabain makes arteries more sensitive to sympathetic stimulation, and as a result the enhanced artery constriction promotes chronic hypertension.
“Now that we understand the role of ouabain, we can begin working on how to modify this new pathway to help people with cardiovascular problems,” said Dr. Blaustein. “The potential for this is big.” Dr. Blaustein, who has been doing research on the substance since 1977, said medications that block ouabain’s effects might improve the lives of people with hypertension and heart failure.
The researchers, who include Vera Golovina, Ph.D., an adjunct associate professor of physiology at UM SOM, and Bing Huang, M.D, Ph.D., a research associate at the Ottawa Heart Institute, also found significant new evidence that ouabain is manufactured by mammals, a question that had not been previously answered.
“This discovery underscores the crucial importance of basic research here at the School of Medicine,” said Dean E. Albert Reece, MD, PhD, MBA, as well as vice president of medical affairs, the University of Maryland and the John Z. and Akiko Bowers Distinguished Professor. “These scientists have spent years unraveling the many potential roles of ouabain and how it works, and now we are beginning to see the fruits of their labor.”
Scientists aim to give botox a safer facelift
New insights into botulinum neurotoxins and their interactions with cells are moving scientists ever closer to safer forms of Botox and a better understanding of the dangerous disease known as botulism. By comparing all known structures of botulinum neurotoxins, researchers writing in the Cell Press journal Trends in Biochemical Sciences on October 1st suggest new ways to improve the safety and efficacy of Botox injections.
"If we know from high-resolution structures how botulinum neurotoxins interact with their receptors, we can design inhibitors or specific antibodies directed at the binding interface to prevent the interaction," said Richard Kammerer of the Paul Scherrer Insititute in Switzerland. "Furthermore, it may be possible to engineer safer toxins for medical and cosmetic applications."
In addition to its popular cosmetic use, the neurotoxin is used for the treatment of muscle conditions related to cerebral palsy, multiple sclerosis, stroke, Parkinson’s disease, and more.
The bacterium known as Clostridium botulinum, classically found as a contaminant in home-canned food, produces the neurotoxins, which pass the intestine and enter the bloodstream when ingested, Kammerer explained. When the neurotoxins reach neurons, they bind to receptors at the cell surface. Through a series of events, a portion of the toxin is released inside the cell. Once inside, that light-chain portion acts as a protease to specifically cleave a protein important for the release of acetylcholine, a neurotransmitter important for signaling from nerve to muscle. The result is paralysis, which can be fatal if the muscles required for breathing are affected.
Kammerer and his colleagues offer a comprehensive review of high-resolution structures of botulinum neurotoxins and their complexes with cell-surface receptors, many of which have become available only recently. While many questions remain, the new picture of BoNT/A and its interactions offers considerable hope for less-risky clinical use of Botox in the future.
"The wide range of BoNT/A dosage used in medical or cosmetic applications bears the substantial risk of accidental BoNT/A overdosage," the researchers write. "The BoNT/A-SV2C complex crystal structure provides a strong platform for the rational design of BoNT/A variants with attenuated SV2C binding properties. Such variants are promising candidate proteins for safer applications of the toxin."
(Source: eurekalert.org)
Medical discovery first step on path to new painkillers
A major medical discovery by scientists at The University of Nottingham could lead to the development of an entirely new type of painkiller.
A drug resulting from the research, published in the journal Neurobiology of Disease, would offer new hope to sufferers of chronic pain conditions such as traumatic nerve injury, for which few effective painkillers are currently available.
The work, led by Dr Lucy Donaldson in the University’s School of Life Sciences, in collaboration with David Bates, Professor of Oncology in the University’sCancer Biology Unit, focuses on a signal protein called vascular endothelial growth factor (VEGF).
VEGF controls the re-growth of blood vessels in tissues which have been damaged by injury. It is a widely targeted compound for cancer, eye disease and other illnesses in which abnormal blood vessel growth occurs.
Drugs are used to inhibit the VEGF in cancer, which can otherwise lead to the formation of new blood vessels that provide oxygen and nutrients to tumours.
Professor Bates and colleagues had previously discovered in 2002 that VEGF comes in two forms and acts like a switch — one which turns on the growth of blood vessels and another that blocks growth.
Pain prevention
However, this latest research has shown for the first time that these two forms of VEGF not only act on blood vessels but also differently affect the sensory nerves that control pain.
The academics discovered that the VEGF that promotes blood vessel growth causes pain, while the other, which inhibits blood vessel growth, prevents pain.
The study has centred on understanding how these two types of VEGF work and why the body makes one form rather than the other.
The academics have been able to switch from the pain stimulating form to the pain inhibiting VEGF in animal models in the laboratory and are now investigating compounds to replicate this in humans. It is thought these compounds could form the basis for new drugs to be tested in humans in clinical trials.
A safer approach for diagnostic medical imaging
Medical imaging is at the forefront of diagnostics today, with imaging techniques like MRI (magnetic resonance imaging), CT (computerized tomography), scanning, and NMR (nuclear magnetic resonance) increasing steeply over the last two decades. However, persisting problems of image resolution and quality still limit these techniques because of the nature of living tissue. A solution is hyperpolarization, which involves injecting the patient with substances that can increase imaging quality by following the distribution and fate of specific molecules in the body but that can be harmful or potentially toxic to the patient. A team of scientists from EPFL, CNRS, ENS and CPE Lyon and ETH Zürich has developed a new generation of hyperpolarization agents that can be used to dramatically enhance the signal intensity of imaged body tissues without presenting any danger to the patient. Their work is published in PNAS.
The team of scientists coordinated by Lyndon Emsley – who is currently Professor at EPFL and ENS Lyon – has developed a new generation of hyperpolarizing agents that are both effective and safe for the patient. The substances, called HYPSOs, were developed by the teams of Christophe Copéret at ETH Zurich and Chloé Thieuleux at CPE-Lyon. The HYPSOs come in the form of a fine, white, porous powder that contains the “tracking” molecules to be hyperpolarized. The HYPSO powder is made up of mesoporous silica (silicon dioxide), which is the major component of sand and is commonly used in nanotechnology.
The silica powder used for the HYPSOs consists of particles, containing pore channels. It has been designed in such a way that the surface of each pore channel can be evenly covered with molecules known as ‘organic radicals’. The radicals are homogeneously distributed, and are able to induce polarization around them. “Controlling the radical distribution was a ‘tour de force’ never achieved in the past, which made the HYPSO materials ideal for this application,” says Christophe Copéret. The pore channels are then filled with a solution of the “tracking” molecules to be hyperpolarized, which act as markers for the imaging – e.g. pyruvate, which is important in the production of energy in cells.
Using novel instruments and methods developed by Sami Jannin at EPFL, the HYPSO sample is hyperpolarized with microwaves in a magnetic field at a very low temperature. The magnetic moments of the atoms are forced to align through a process called “dynamic nuclear polarization”, which transfers the spin energy of the free radicals’ electrons to the markers’ nuclei. The electronic spin magnetism of the hyperpolarizing agent acts on the marker molecule, aligning, or “polarizing”, the nuclei of its atoms.
Hot water is then used to melt and flush the substrate out of the powder. Because of the equipment and conditions needed, the process generally takes place in a room adjacent to the imaging facility. The substrate is then ready to be injected through a long tube into the patient inside the medical imaging device. The entire process only lasts about ten seconds.
Two scans are performed, one with and one without the hyperpolarized agent. When the two images are compared, it is possible to observe the distribution of the hyperpolarized marker in the patient’s body, which, depending on the medical context, can be indicative of disease. For example, accumulation of pyruvate in the prostate could be an early indication of prostate cancer.
The researchers have tested the efficiency of the HYPSOs method on several imaging markers, including pyruvate, acetate, fumarate, pure water, and a simple peptide. Because the HYPSOs is physically retained during dissolution, the technique yields pure solutions of hyperpolarized markers, free of any contaminant. The protocol is therefore simpler and potentially safer for the patient, while its dramatic efficiency on signal quality forecasts the use of this new generation of hyperpolarized agents with a broad range of molecules. As Sami Jannin points out: “We have now received queries of scientists from abroad who are eager to boost their research with this new technology. Amongst other plans, we are very excited about testing these materials in vivo”.
(Source: actu.epfl.ch)
Device lets docs stay ‘tuned in’ to brain bloodflow
For Dr. John Murkin, the medical device business is all about “making a better mouse trap.”
The Schulich School of Medicine & Dentistry professor is part of a team of Western and Lawson Health Research Institute (LHRI) researchers studying a new technology that may change the way patients undergoing cardiac surgery are monitored and managed in the hospital.
The device, known as CerOx, non-invasively monitors cerebral blood flow and helps physicians and nurses assess brain perfusion in real time. Murkin, who has been involved in the machine’s development, said this information could be used to support critical treatment decisions made to protect the patient from potential complications.
“We use near-infrared light routinely in all hospitals to measure oxygen saturation in the brain. That’s been out for 30 years,” Murkin said. “This new device is not just measuring oxygen saturation; it’s also measuring blood flow to the brain, in real time, and non-invasively.
“If a patient has a brain injury, the more you know about the brain, the better you are at being tuned into their needs.”
In cardiac surgery, cerebral monitoring significantly reduces complications, including permanent stroke.
An anesthetist at London Health Sciences Centre and a researcher at LHRI, Murkin has studied cognitive and neurological outcomes in cardiac surgery for more than three decades. He said there has been an unmet clinical need for a noninvasive tool that provides accurate, real-time measurements of cerebral blood flow in these highly vulnerable patients.
Currently, 11 different studies have evaluated CerOx in different applications.
“We’ve seen the potential of the machine and we’re convinced it works,” he added. “If you don’t know what’s going on in the brain, you can’t help. But, when you start to monitor this, and you see changes in blood flow, in oxygen saturation and its because of the blood pressure or hemoglobin, or whatever it is, if you pick things up early enough, you can hopefully avoid any possible complications.
“If you can monitor in real time, you can act in real time.”
The device is expected to be used primarly by physicians in neuro-critical care areas.
“While the device can alert you to potential problems, the next part is what are you going to do about it? You still need to act,” he said. “We want to start looking at what are some of the therapeutic interventions we can use to improve outcomes.”
CerOx was developed by U.S.- and Israel-based Ornim Medical, of which Murkin is a member of their scientific advisory board.