To understand and measure the dynamics of the blood flowing in the heart, has been a subject of interest for centuries. Today we know that abnormal blood flow can be markers for developed or developing heart disease.

Given that cardiovascular related diseases are the most probable cause of death globally, according to WHO, we believe that more information regarding blood behaviour can help the doctors make better diagnosis at an earlier stage. But how can you measure these properties inside the heart, behind the ribs, under the skin, without moving the patients from their bed?

At CIUS (Center for Innovative Ultrasound Solutions) resources are put into finding and developing new ultrasound methods achieving this from different angles. Estimating velocities with ultrasound is usually based on the Doppler effect.

A well-known phenomenon caused by the Doppler effect is the change of the observed frequency – the sound pitch – when an ambulance is passing you with sirens. Due to the velocity of the ambulance we get a frequency change of the sound waves, but we also get an additional frequency change depending on where we are in relation to the ambulance.

The first effect can be used to calculate the speed of the ambulance; however, the latter makes this more challenging. In more technical terms; using Doppler we only measure one of the three velocity components of a moving object, that is the component in the direction of the sound waves.

Photos: The first picture shows a rig used for validating our method.  An artificial ventricle (second picture) – imaged alone on the ultrasound scanner – was made with a circulation system to simulate blood flowing in a heart chamber.

In my Ph.D. project, we want to overcome the current limitations of the Doppler measurements and estimate the true three-dimensional velocity components in a three-dimensional volume, i.e. the adult heart’s left ventricle. As blood motion is a 3D phenomenon, our hypothesis is that such a method can gain additional information compared to current available methods and ease that task of understanding flow behaviour and to distinguish normal from abnormal blood flow.

When looking at an ultrasound image of the heart, blood appears invisible (dark) compared to the surrounding heart walls (bright). An analogy to this can be a fly-fisher trying to see salmon in a river in bright daylight. The water surface reflects so much of the light that what is beneath the surface is obscured. The fisher would put on sunglasses with a polaroid filter to look beneath the water surface. Our equivalent to polaroid glasses are called clutter-filters, which exploits that signal from blood have different frequency components than it’s surroundings, making it possible to filter out the strong signal from the stationary objects(tissue).

When our ultrasound signal is filtered, we are left with signal coming from the blood alone, and we can perform blood velocity estimation. The raw ultrasound data are acquired at the scanner at the rate of ~20 GB/s(!) and can produce thousands of volume frames per second. With such a high frame rate the blood will just slightly move between each frame. This small motion is tracked by our developed tracking algorithm which estimates one corresponding velocity estimate in every 3D pixel (voxel) of an acquired volume. We acquire these frames through the cardiac cycle, process the data, and then do measurements and visualize the velocity field of the blood. We typically acquire one set of images to see anatomy (black and white background), called bmode, and one for the blood flow estimation, visualized as orange particles in the last figure.

First image: Example of ultrasound images of a child’s heart before clutter filtering.
Second image: Same data at same rate as to the left, however, with applied clutter filter. Now the blood can be seen moving in the heart’s ventricles. This child’s heart has a congenital heart disease with a shunt between the two ventricles.

The above describes the principles in the technology used in my research, the real world is, however, more problematic and challenging. A fundamental challenge when imaging the heart is to transmit and receive sound waves through the chest. As the high frequency sound waves we use don’t penetrate the chest ribs, we must use an ultrasound probe with a very small aperture which limits the resolution – same as with cameras where larger apertures and full frame sensors have sharper images than a phone camera.

Clutter-filtering is not as ideal as described, as the heart is also moving, making it sometimes difficult to distinguish the signal from blood and tissue. The processing we do is also very computationally demanding, and takes around 1 hour for each dataset. In other words, the method is not currently running in real-time, which is one of ultrasounds strength, but with the help of time, technology will catch on making also this possible.

All-in-all we have promising and uplifting results and we can say that we are the first in the world to demonstrate 3D blood flow in the hearts whole left ventricle, but we also face challenges and will need feasibility studies to find out how this can be used on patients.

3D visualization of blood flowing through a cardiac cycle in a healthy volunteer. The black and white slices, are called bmode and shows anatomy, while the blood’s movement is visualized as synthetic particles in orange.

Recently we had our half-yearly conference, where academics, industry and user partners come together to talk about the latest developments, challenges and ultrasound solutions across sectors and professions.

The first international speaker, Professor Jan D’Hooge, K.U. Leuven, Belgium, talked about the advantages of speckle tracking in his presentation “Speckle tracking echocardiography: the present and the future”. Speckle tracking echocardiography (STE) is used to provide quantitative and qualitative information on deformation and the motion of cardiac muscles. However, as a relatively new technique, there are some questions about how reliable the data is – are changes over time due to an actual change in the heart muscle (i.e. potential damage), or due to different doctors making the recordings? And can one compare images from two different brands of ultrasound machines (inter-vendor reliability)? Professor D’Hooge has been part of a Task Force aiming to provide quality assurance on inter-vendor reliability (which found that 10% difference is acceptable). Professor D’Hooge also believes machine learning will make diagnostics easier by automated image interpretation.

Speed-of-sound is another ultrasound technique exploiting the acoustic impedance of various tissue – i.e. the speed at which the ultrasound waves are reflected. Dr. Michael Jaeger from the Institute of Applied Physics at the University of Bern, Switzerland, presented his work on computed ultrasound tomography in echo mode (CUTE) in the presentation “Pulse-echo sonographic imaging of speed-of-sound in handheld diagnostic ultrasound”. One of the advantages is that speed-of-sound ultrasound can for example detect liver tissue changes that today’s clinical ultrasound cannot detect. However, there are still challenges with clutter; real-life gives less accurate readings than simulations, and reconstruction in regions of missing data (finding an optimum interpolation strategy).

As a Centre for Research-based Innovation (SFI), CIUS includes partners from the ultrasound industry and end-users. Dagfinn Sætres, General Manager at GE Vingmed Ultrasound, presented the lastest developments on the cSound beamforming platform, which boasts more opportunities for further development by engineers, reduced need for contrast agents, clearer borders colour flow imaging.

Andrew Healey, Chief Scientific Officer at Phoenix Solutions, talked about Phoenix’ Acoustic Cluster Therapy (ACT), which uses microbubbles and nanoparticles do deliver chemotherapy directly to the tumour and releasing it using ultrasound. You can read more about this in the blog post: Microbubbles and focused ultrasound cure tumours in mice.

The final partner presentation was by Halfwave Director of R&D, Petter Norli, who presented the company’s acoustic resonance technology (ART) focusing on monitoring and inspection of land and subsea pipelines and structures, looking for cracks and faults using ultrasound technology.

Furthermore, academic partner University College of Southeast Norway (HSN) represented by Professor Lars Hoff gave an overview over the facilities and capabilities of their laboratories in Horten. NTNU Professor Hefeng Dong gave a talk on Passive Acoustics for Seabed Characterization, and Roy Edgar Hansen from the University of Oslo and the Norwegian Defence Research Establishment (FFI) gave an overview over Seabed Imaging with Synthetic Aperture Sonar.

The seminar also included a speed update session with the following topics:

• Characterising piezoelectric material parameters through a 3D FEM and simulated annealing algorithm, PhD student Marcus Wild, HSN
• Numerical optimisation method of ultrasound transducers, PhD student Kenneth Kirkeng Andersen, HSN
• CustusX – a research platform for ultrasound and image guided treatment, senior researchers Tormod Selbekk and Jon Eiesland, SINTEF
• Nanoparticle-stabilised microbubbles for ultrasound-mediated drug delivery, PhD student Sofie Snipstad, NTNU
• Adaptive clutter filtering in coronary arteries, PhD student Cristiana Golfetto, NTNU
• Model-based regularisation of blood flow measurements, PhD student Thomas Grønli, NTNU
• Prestations of X-FAB, Business Line Manager ing. Ulrich Bretthauer, X-FAB
• Glimoa imaging with PET MRI and its use in ultrasound navigated surgery, Anna Karlberg, PhD student and PET physicists, St. Olavs Hospital

Finally, CIUS’ new Industry Liaison Officer, Svein-Erik Måsøy was presented to the audience. Måsøy will be the contact point between CIUS and its industrial partners.

Blogger: Catharina de Lange Davies, professor Department of Physics, NTNU

A prerequisite for successful chemotherapy is that the drugs reach its target, and that damage to healthy tissue is limited. However, when drugs are injected into the blood, less than 1% of the drugs accumulate in tumours. Microbubbles combined with focused ultrasound shows great promise in enhancing delivery of nanoparticles and drugs thereby improving cancer therapy. Focused ultrasound and nanoparticles can also be used to temporarily open the blood-brain barrier thereby allowing nanoparticles and drugs to enter into brain tissue, which enables treatment of brain disorders. At the Department of Physics, NTNU, we are using two types of new microbubbles to improve the delivery of nanoparticles and drugs in combination with focused ultrasound.

Fig 1: Microbubbles (right) stabilised by nanoparticles (left). The nanoparticles form a shell at the microbubble surface.

SINTEF Materials and Chemistry has developed a new drug delivery system consisting of nanoparticles forming a shell around microbubbles (Fig 1). These nanoparticle-microbubbles have been fluorescently -labelled and injected into the blood in mice with prostate cancer tumours and breast cancer. When combined with optimised ultrasound (1 MHz, MI=0.5, 1000 cycles), the uptake of nanoparticle/dye increased 2.5 times compared to untreated mice.

These encouraging results have been followed up with a small pilot (proof of principle) study where the drug cabazitaxel was incorporated into the nanoparticle. Nanoparticle-microbubble and ultrasound were given twice with one week in between each treatment. The growth of breast cancer tumours was reduced considerably and disappeared, i.e. all tumours went into complete remission. We cured all the mice! We have also shown that these nanoparticle-microbubbles and focused ultrasound temporarily and safely open the blood-brain barrier.

Fig 2: Ultrasound applied to tumors after injecting clusters of microbubbles/microdroplets causes giant oscillating bubbles.

Our other microbubble is developed by one of CIUS’ industry partners, Phoenix Solutions AS. The concept called Acoustic Cluster Therapy (ACT) is based on clusters of microbubbles and microdroplets. After injection, focused ultrasound (using the handheld ultrasound apparatus VScan at 2 MHz, MI=0.4 for 45 sec) is applied to the tumour/disease area whereby the microbubbles transfer energy to the microdroplets, which change from liquid to gas form (Fig 2).

Growing in size to 25 µm, these large bubbles temporarily lodge and block the blood flow at the capillary blood vessel level for up to 10 min. Further exposure to focused ultrasound (500 kHz, 8 cycle every 1 msec for 5 min at MI=0.2) causes these large bubbles to oscillate and increases the ‘leakage’ of drugs or nanoparticles from the blood vessels to the diseased area Fig 2 (4,5). A major advantage for these microbubbles is their large size ensuring close contact between the microbubble and blood vessel wall, and enhancing the mechanical effect on the vessel wall 1000 times compared to regular microbubbles. We have demonstrated that the ACT concept successfully enhances the delivery of macromolecules to prostate tumours growing in mice, by 2-3 times.

Next, we showed that combining ACT with co-injection of the drugs paclitaxel and Abraxane®, induces a very strong increase in the therapeutic efficacy of human prostate tumours in mice. After injecting Abraxane® at a dose used in the clinic combined with ACT, all of the treated mice were alive 120 days after the study started, and 67% were in stable, complete remission. Furthermore, we have shown that ACT can open the blood-brain barrier safely, allowing macromolecules to enter into the brain tissue.

These encouraging preclinical results will now been taken to the clinic. ACT will go into clinical trial in 2018, and at St. Olavs Hospital we will start a clinical study of patients with inoperable pancreatic cancer. The patients will receive standard chemotherapy, diagnostic microbubbles and focused ultrasound using new 3D ultrasound probes with two frequencies. Hopefully, these clinical trials will lead to new clinical practice and improved cancer therapy.

The projects are supported by Helse Midt-Norge and the Research Council of Norway.

Further reading:

• Mørch Y, et al, Nanoparticle-stabilized microbubbles for multimodal imaging and drug delivery. Contrast media & Molecular imaging, 10, 356-366, 2015.
• Eggen S, et al, Ultrasound-enhanced drug delivery in prostate cancer xenografts by nanoparticles stabilizing microbubbles. J Controlled Release, 187, 39-49, 2014.
• Åslund AKO, et al, Nanoparticle delivery to the brain–By focused ultrasound and self-assembled nanoparticle-stabilized microbubbles. J. Control Release, 220, 287-294, 2015.
• Sontum, PC, et al, Acoustic Cluster Therapy (ACT)–A novel concept for ultrasound mediated, targeted drug delivery. Int J Pharm, 495 1019-1027, 2015.
• Healey AJ, et al, Acoustic Cluster Therapy: In Vitro and Ex Vivo Measurement of Activated Bubble Size Distribution and Temporal Dynamics. J, Ultrasound Med Biol, 42, 1145-1166, 2016.
• van Wamel A, et al, Acoustic Cluster Therapy (ACT) – pre-clinical proof of principle for local drug delivery and enhanced uptake. J. Control Release, 224, 158-164, 2016.
• van Wamel A, et al, Acoustic Cluster Therapy (ACT) enhances the therapeutic efficacy of paclitaxel and Abraxane® for treatment of human prostate adenocarcinoma in mice. J Controlled Release, 236:15-21, 2016.
• Åslund AKO, et al, Efficient Enhancement of Blood-Brain Barrier Permeability Using Acoustic Cluster Therapy (ACT). Theranostics 7, 23-30. 2017.

Blogger: Ingrid Eftedal, Principal investigator
Barophysiology research group, Department of circulation and medical imaging

White blood cells are essential components of the immune system. Without these cells we would not stay healthy for long on a planet where infections thrive. But what are these cells up to when we’re not sick? They are present. And they are active, at all times.

Lean back and breathe in. Hold your breath. It can’t get much easier; what could there possibly here for a scientist to study? Well, there is something.

Evolution has shaped us for the environment we live in, and our environment is never completely static. The immune system is involved in rapid biological adjustments that protect us from harm caused by environmental perturbations. Some perturbations are of a cyclic nature, like those that are linked to the earth’s rotation around the sun and its own axis. In an elegant study published in the journal Nature in 2015, English and German scientists identified variations in the immune system that are perfectly aligned with the seasons. Actually, our bodies appear to lie slightly ahead of the seasonal changes: we appear to have a biological memory that fine-tunes the immune system just before the seasons change. Since many common infectious diseases appear in a seasonal pattern, this is an amazing adaptation for life on planet earth. If we speed the cycle up a bit, related effects have been observed over the 24 hrs cycle.

So the immune system shows cyclic variation.

What happens if we speed it up to the cycle of our breath?

Most of the time, we breathe without thinking about it. Our cells need oxygen for energy production, and once we have filled our lungs with air, it is the circulatory system – i.e. the heart, blood vessels and blood – that distributes oxygen to the cells in all parts of our body. We can all voluntarily hold our breath for a while, but some people do this better than the rest. Freedivers dive while holding their breath; the best of them can hold their breath for over 10 minutes.

Eleven-time free-diving world champion Goran Colak during a bout of static apnea; timed breath-holding while immersed in water .We have used blood samples from elite free-diving athletes to examine how white blood cells of the immune system responds to acute reduction in blood oxygen levels. The photo is used with Goran Colak’s permission.

In order to understand how white blood cells respond to an altered breathing pattern, we studied some of the world’s best free-diving athletes. We used a simple design: blood samples were drawn from contestants at an international free-diving competition before start, and then again one and three hours after completion of a series of dives where the athletes either lay face down in water or swam close to the surface for as long as they could.

Then the samples were transported to the NTNU Genomic Core Facility where total gene expression in the athletes’ white blood cells was measured by a method called full genome microarray analysis. The analysis results were striking: the activity of more than 5000 genes changed in response to the simple effort of breath-holding. This is almost ¼ of all genes found in human cells. With this amount of data we could dig deeper into cellular biology and calculate which specific types of white blood cells that reacted to breath-holding, and also see finer details in the biological processes going on within the cells.

The figure shows a selection of white blood cell types in samples taken from athlete free-divers. Blue boxes are cell amounts prior to diving, whereas the red and green boxes show the same cells one and three hours after diving. The main changes identified were a marked increase in the amount of neutrophil granulocytes, whereas two types of lymphocytes; CD8-postivie cells and natural killer (NK) cells, decreased. Calculations of relative amounts of specific white blood cell types were done by mathematical deconvolution of global blood gene expression data.

The most striking finding we did was a marked increase of the white blood cell type neutrophil granulocytes. These blood cells are programmed for rapid response when the body perceives attacks from intruders; the neutrophils are capable of killing invading cells simply by eating them. But they also have another interesting trait that emerges when oxygen levels drop: neutrophil granulocytes are evolutionary old-timers that stem from an era when the atmosphere contained less oxygen than now, and their modern offspring still prefer environments where the oxygen levels are low. White blood cell types that use more oxygen – like lymphocytes – were less active in blood drawn after the athletes held their breath. What we observed are likely to be traces of evolutionary history still embedded in our immune system, visible when oxygen levels change. The study was published in November 2016 in the journal Physiological Genomics.

This study was done on healthy athletes.

Can it be relevant for understanding of human diseases?

Healthy people normally don’t have to worry about oxygen, but for common diseases like chronic obstructive lung disease (COPD) and sleep apnea, the body’s oxygen supply is limited. These diseases are associated with persistent inflammatory conditions, and increased risk of infections; both indicative of an impaired immune system. If we can use data from healthy individuals to distinguish secondary effects of low oxygen levels from the primary pathology of the disease, this may in turn be helpful for prevention and treatment strategies.

– And breathe out.

Bloggers:
Marianne Bjordal Havnes, Post Doc
Andreas Møllerløkken, Researcher,
The Barophysiology group at the Department of circulation and medical imaging

Researchers are trying to find out why U-2 pilots operating in high altitude have  central nervous system changes in a NATO-led project involving researchers from the Barophysiology group at NTNU, researchers from the U.S. Air Force in Texas and from the Institute of Aviation Medicine in Oslo.

You have probably been in a passenger jet, and as you get ready for take-off, you register the cabin attendants going through the safety instructions, mentioning something about loss of cabin pressure and oxygen masks, but you don’t worry about it. 15 minutes later the captain announces that the airplane has reached its cruising altitude of 38,000 feet. At this altitude the barometric pressure is only 1/5 of sea level pressure.

Inside the aircraft the pressurisation system ensures that the cabin altitude according to international regulations will never exceed 8000 feet = ¾ of sea level pressure. So while you are travelling, you are actually performing a little mountain-excursion to the same altitude as Norway’s highest mountain, Galdhøpiggen.

Now imagine that you are flying twice as high as your airliner. At an altitude of 70,000+ feet the barometric pressure is 1/25th of an atmosphere. You can see the curvature of the earth and the blackness of space above. This is where the U-2 pilots are working. If you lose the cabin pressure in this environment, an oxygen mask will be of no help. You need to wear a space suit that will instantly inflate to a pressure of 0.3 bar (corresponding to 30,000 feet) and supply you with a breathing gas of 100% oxygen.

The U-2 planes have been operating since the 50s and are still in active duty. In fact, U-2 pilots have actually been flying more the last 10 years as other high-altitude reconnaissance airplanes have retired. This has resulted in an increased number of neurologic decompression sickness episodes.

A US Air Force research team has published findings of what are called white matter hyperintensities in the brain on magnetic resonance imaging (MRI) of U-2 pilots (McGuire et al., 2013) . Recently they have discovered similar findings in U.S. Air Force altitude chamber instructors (McGuire et al., 2014). This group works inside hypobaric chambers, training aircrew including U-2 pilots, in the effect of loss of cabin pressure and lack of oxygen. The altitude exposure in hypobaric chamber training is usually much shorter and less severe than in U-2 operations. None of the other U.S. Air Force control groups they have tested so far, including Air Force doctors, have had similar changes.

The U.S. Air Force research team visited the Institute for Aviation Medicine, Oslo, Norway, and wanted to meet Norwegian research groups that might contribute to understanding the pathophysiology behind the findings. Members of the NTNU Barophysiology group were invited based on their merits for a long time commitment to research on man in extreme environments.

Most of the work of the NTNU Barophysiology group has been related to the activity of diving and the adverse effects of working under water. Presently, the research is funded by the Norwegian Research Council through the Petromaks programme.

From left: Berit Holte Munkeby, MD, PhD, Norwegian Armed Forces, Dr Paul Sherman, USAF, Andreas Møllerløkken, PhD NTNU, Marianne Bjordal Havnes, PhD, NTNU, Dr Stephen McGuire USAF.

One of the technologies we are using in assessing possible stress after a dive is ultrasound detection of gas bubbles found in blood veins. These bubbles will form in nearly all diving activity, and it is recognised that the risk of decompression sickness increases with increasing amounts of bubbles.

Our way of observing vascular gas bubbles after diving has become a recognised method for evaluating procedures.  It has also been shown both in animals and humans that the bubbles themselves influence the endothelium lining all blood vessels. When going to high altitudes, the pressure changes are opposite of diving. But there are many similarities as well, and the formation of bubbles is thought to be involved in the formation of the white matter hyperintensities.

After the meeting in Oslo, the researchers from NTNU did some preliminary investigations, and were invited to Lackland Air Force Base in Texas where the main investigation is taking place. The results from the tests at NTNU have already been presented at a NATO high altitude exposure meeting this summer in Paris, and has gained a lot of attention within NATO. Together with the Institute of Aviation Medicine in Oslo, the researchers from the Department of circulation and medical imaging are eager to continue the investigations.

Blogger: Fatima Zohra Kiboub
Industrial PhD Candidate, Lead QHSE Engineer, Technip

The working environment, health and safety of an offshore diver has significantly improved since the 1990s and saturation diving is today among the safest offshore occupations.

Crucial to our gas and oil industry, the offshore divers perform their work on the ocean floor of the Norwegian continental shelf. Not unlike the astronauts, these divers – the aquanauts – encounter environments that challenge the body’s capacity for adaptations. We look at how their bodies respond and what makes them fit and healthy.

Saturation diving is a very challenging job and the divers have to be extremely fit and healthy. The divers live at an elevated atmospheric pressure inside a pressure chamber, which is equal to the pressure at the water depth they will work at. They breathe a mixture of helium and oxygen called Heliox, which makes their voices sound like Mickey Mouse!

When working at depths of 50-180 metres, it is dark and the seawater is very cold – around 4-8°C. The divers are therefore dressed in neoprene wet suits where heated seawater is pumped through to keep them warm. It is like floating in a heated spa pool. They wear a helmet, wellington boots and rubber gloves, which could be mistaken for dishwashing gloves.

Many research projects have been conducted with recreational divers and also offshore air divers, but there are not many research projects on offshore saturation diving – and even less research done with real-life saturation divers in their own working environment.

New science indicates that the high-pressure working environment makes the body initiate an inflammatory reaction, with possible release of stress biomarkers into the blood stream. This is of course closely linked to the function of the vascular system. This gave us the idea to not only study the effects of diving on the vascular system and how the body adapts to such conditions; but also how to improve the long-term health monitoring.

The main part of my PhD project is to see if the intake of antioxidants in the form of vitamin C and E will reduce the stress biomarkers found in the blood of saturation divers. The participating offshore divers will be given vitamins every day whilst living in the pressure chamber and blood samples will be taken before entering and upon leaving the chamber. The results will be compared with a control group not taking vitamins.

After obtaining the approval of my employer, Technip – which performs subsea construction work for the oil & gas industry; and after securing funding from the Norwegian Research Council and the necessary ethical authorisation to perform research on humans, I could start my PhD research at the Medical Faculty at NTNU doing data- and samples collection during the 2015 offshore season.

Here you can see my manager Morten in the improvised ultrasound testing room and Andreas in the back making sure that the FMD protocol was followed properly.

Before going offshore, one of my PhD supervisors, Andreas Møllerløkken, provided training on how to use an ultrasound machine to run a test called Flow Mediated Dilation (FMD). This test measurers how much a large artery of the arm can expand after the blood flow has been reduced for 5 minutes using an inflated blood pressure cuff. FMD is a much used indicator of vascular health. We used my office colleagues as guinea pigs in order to practice before going offshore.

We also obtained the centrifuges and cooling transportation boxes required for our mission, and on 2nd June, it was time for the fun part of the project to begin!

My main supervisor, Ingrid Eftedal, and I took all the equipment to the hospital on board the Skandi Arctic Dive Support Vessel. We received a warm welcome by all the crew, and by the end of the first day, we had already tested two divers.

The divers had joined the vessel by 6th June. They all went through the medical pre-dive check and some were also due to have their annual direct oxygen uptake (VO2max) test.

Initially, eight divers agreed to participate in the project, and we took their blood samples and ran FMD tests. It was a great relief to actually get started.

As the blood samples also will be used in two other research projects run by the barophysiology group at NTNU, we are taking four test tubes of blood from the divers and 3 from the non-divers to study different paramenters. This has earnt me the nichname ‘The Vampire’, although it is the nurse taking the actual samples!

We centrifuge the tubes with blood and anticoagulant to separate the plasma into tubes for freezing and later analysis at the NTNU laboratory.

We also measure percentage of red blood cells onboard, and record the results in our log sheet.

In addition to ‘normal’ health check such as taking the blood pressure, we ran FMD test using an ultrasound machine in combination with an electro cardiogram (ECG). This test shows how much the brachial artery in the arm can expand after 5 minutes of pressure in the forearm. It is a good indicator of artery elasticity reflecting vascular health.

The divers who were due to take their annual VO2max test, measuring the maximum oxygen uptake in the blood, were running on the onboard treadmill placed within the vessel’s hospital.

I have to say it is not easy to work when the ‘ground’ is moving in all directions all the time, but when the sea calmed down enough, it was safe for the divers to run on the treadmill. All our non-divers also passed the test with extremely good results – it is amasing how fit these guys are despite varying lifestyles and age groups!

In fact there is a bit of jovial competition around the VO2max tests. And the vessel has several provisions for staying active with half a basketball pitch, golf course simulator, boxing gym, table-tennis room and a darts board in addition to the two gyms.

On 9th June there was a crew change, another four of the divers agreed to participate in the project. As one of my biggest concerns has been to get enough divers to participate and to be able to do the tests as planned, I was very pleased about this.

By the 14th June, the campaign was completed and we headed back to Stavanger. Here I did a full handover to the new nurse, who would perform the tests on the batch of divers coming out of decompression on the 15th. The day after, a new team of divers arrived, and most of them agreed to participate thanks to the efforts of our crewing office in Aberdeen.

The diving chambers control room onboard the Skandi is there to keep the divers safe inside the pressurised chambers until they are decompressed back to surface pressure again – a process that can take 2-10 days depending on the depth the divers have been working at

In July I will sign on again, and if all goes well, I will be done with all the sampling and diver testing by mid-July, just in time to spend Ramadhan in Stavanger. In the autumn I will analyse the blood samples and test results, and hopefuly we will be able to share some early results with the Skandi Arctic crew presenting the results to those that partcipated or otherwise have shown an interest in our work.

Working offshore has its challenges including seasickness and a working environment in constant motion. Although phone signals were patchy I managed to get in touch with my family in Algeria and tell them their Saharan girl was having a blast in the middle of the North Sea!

Fatima Zohra Kiboub is a Lead QHSE Engineer at Technip and is doing an industrial PhD with the barophysiology group at the Deparment of circulation and medical imaging (ISB) at NTNU.

Want to know more about life onboard the Skandi Arctic? Check out this video.

When bacteria infect the host an explosive immune response is initiated. Normally, this response is local and short-lived and results in elimination of the pathogen and healing of the injury. In other cases, the bacteria may enter the blood stream and cause a life-threatening situation called septic shock. Our immune system uses Toll-like receptors to detect and eliminate microbes. One of these receptors is TLR4 that recognizes Gram-negative bacteria. TLR4 is found in an immune cell called macrophage.

It is still not known in detail how TLR4  mounts an effective immune response against bacteria. CEMIR researchers have previously shown that the localization of TLR4 in cells plays an essential role for the type of immune response that is initiated in the macrophage.

The study also delineates and visualizes the mobility and transport mechanisms of the signaling complex to compartments inside immune cells where production of signaling molecules occurs. The recent data  published in Traffic journal provide us with new fundamental understanding of the mechanisms behind bacteria-induced inflammation downstream of TLR4 and may point to new drug targets for more effective treatment of Gram-negative sepsis.

Answer from: Ioanna Sandvig,
Research scientist at Department of Neuroscience, NTNU and Visiting research scientist, John Van Geest Centre for Brain Repair, University of Cambridge, UK

Stroke is caused either when a clot blocks a blood vessel and interrupts blood supply to the brain, or when a blood vessel breaks and bleeds into the brain. Both causes result in massive loss of neurons and also other cells in the brain. In fact, about 2 million neurons are lost for every minute that passes after the onset of stroke. As a result, many neuronal connections in a number of different brain locations are permanently lost. This is the reason why stroke patients often have severe, long-term motor and cognitive deficits.

Once neurons die, they cannot grow again. However, neuronal death can be prevented by early clinical intervention aimed at restoring blood supply to the brain. This may be done by surgically removing the blood clot or by administering drugs that dislodge it. Unfortunately, the time window for this type of intervention is very narrow, which effectively excludes a large number of patients from such treatments.

Since our ability to prevent the loss of large numbers of neurons is limited, an alternative option is to replace the lost neurons by transplanting new. Cell replacement therapy, especially with the use of stem cells, which can give rise to neurons, but also other cell types important for brain function, is a highly promising approach in the treatment of stroke and other central nervous system lesions. However, although results from pre-clinical and clinical cell replacement studies are promising, we should not underestimate the complexity of stroke injury and, not least, the complexity of the brain itself. In other words, even if the transplanted cells survive in the brain after stroke, their function and ability to restore lost function is relatively limited.

This is the reason why we are combining stem cell transplantation with other approaches for tissue engineering. Tissue engineering is the smart integration of stem cell technologies with other multi-, and cross-disciplinary technologies aimed at creating a host microenvironment that may mimic healthy, functional tissue. Such approaches do not claim to be replacing part of the brain, however, if successful, they can be expected to have an impact in the quality of life of stroke patients.

During treatment of childhood blood cancer, great variations in side-effects are seen – both in terms of prevalence and seriousness. Some children get more serious side-effects than others. Potentially, the diversity in the toxicity burden for individual patients could reflect the normal genetic variation between patients.

A bone marrow smear at high magnification taken at diagnosis. Most of the blue cells are leukaemic cells. Normal red blood cells are also seen. (Photo: Bendik Lund)

In parallel with the biotechnological development over the last 10-15 years, we have gained extensive knowledge about the normal sequence variation in DNA, which differs from person to person. This sequence variation might explain some of the differences between people, for example height, hair colour, risk of diseases and the body’s reactions to medicines (pharmacogenetics).

There are many types of DNA-variations and one of the most common ones is single nucleotide polymorphism (SNP), where one letter in our genetic code has been replaced by another letter. DNA consists of long chains of base pairs (letters, totalling around 3 billion) and a SNP occurs approximately for every 300th base pair.

We wanted to study what role the natural genetic variation plays in the development of side effects in children treated for leukaemia (cancer of the blood). The most common form of blood cancer in children is acute lymphoblastic leukaemia, and 30-40 children are diagnosed in Norway every year with this type of leukaemia. The treatment consists of chemotherapy given over a period of 2.5 years, and the survival rate today is around 85%. The treatment causes many side effects including reduced immune function and infections. In some cases, the treatment can lead to so serious side effects that the patient dies from the toxicity.

Knowledge about pharmacogenetic variation is already used in the standard treatment for acute lymphoblastic leukaemia when using the chemotherapy 6-mercaptopurine. This drug is dosed based on the patient’s SNP variants for the enzyme that metabolises 6-mercaptopurine (TPMT-genetic variants).

We have collaborated with a research group at the laboratory in Copenhagen (Bonkolab, Rigshospitalet) and, based on existing literature, around 2300 candidate genes that could be significant for children with acute lymphoblastic leukaemia have been identified. Furthermore, the group has made a cost-efficient analysis method where 34,000 genetic variants (SNPs) per patient within these genes (extended candidate gene model) are analysed. Samples from several patients can also be analysed in the same sample tube (multiplexing).

The test tube to the left contains a blood sample from a healthy person. The test tube to the right contains a blood sample form a child with leukaemia. “Leukaemia” means “white blood”, and one can clearly see why when looking at the white layer of cells in the test tube to the right. (Photo: Bendik Lund)

We used this method in a study where we included 69 Danish children with leukaemia and compared the gene variant pattern with clinical data for infections that occurred during the first 50 days of treatment. We identified a SNP profile which with great accuracy can predict the risk for infections in this early phase of the treatment, where many infections are life-threatening.

If these findings are confirmed in similar studies, we may in the future be able to quickly determine whether a patient has an increased risk for serious infections by taking a simple blood test. If the patient is at high risk for serious infections, the treatment could be adapted accordingly for example giving prophylactic antibiotics, or by reducing the intensity of the chemotherapy. Hopefully this will lead to less side effects and higher survival rates.

Further reading:

• Host genome variations and risk of infections during induction treatment for childhood acute lymphoblastic leukaemia
• Risk factors for treatment related mortality in childhood acute lymphoblastic leukaemia

 

The Research Council of Norway has recently awarded grants under the funding scheme Independent Basic Research Projects – Medicine, Health Sciences and Biology (FRIMEDBIO). There is tough competition for this funding nationally, and only the best projects get through. The Faculty of Medicine, NTNU, has been awarded funding for three talented young researchers, three research projects and two post docs. You can read about all these projects on the blog over the coming weeks. Sjoerd Hak received FRIMEDBIO-funding for his post doc project: “Multimodal in vivo study of nanoparticle decomposition and targeting dynamics”

In the field of nanomedicine, the use of drug loaded nanoparticles to deliver drugs to tumours is now well established (see Figure 1).

Tumour bloodvessels are very leaky as compared to healthy vasculature. When drug loaded nanoparticles are injected into the bloodstream, they can leak from the leaky tumour bloodvessels into the tumour tissue; whereas leakage from the blood vessels in healthy tissue is limited.

Exciting developments in nanotechnology have allowed for the production of a wide variety of advanced nanoparticles.

As compared to conventional therapy without nanoparticles, this results in a larger part of the injected drugs ending up in the tumour and a reduction in side effects (Figure 1B).

Figure 1. A: General design of a nanoparticle loaded with drug. The core/shell/surface coating can be composed of a variety of different materials, which has resulted in an enormous diversity in the design, and hence properties, of different nanoparticles. B: When a drug loaded nanoparticle is injected into the blood, it can leak into the tumour tissue due to the leaky tumour blood vessels. C: General design of a targeted nanoparticle loaded with drug. D: Nanoparticles can be specifically targeted to the cells making up the tumour vasculature. When these are injected into the blood, they accumulate in the tumour vasculature. The targeting and subsequent disrupting of tumour blood vessels is a promising therapeutic strategy. E: Nanoparticles can also be specifically targeted to cancer cells. When these targeted nanoparticles are injected into the blood, they accumulate in the tumour and bind to tumour cells, increasing the amount of drug delivered to individual cancer cells.

Although this has improved therapy for a group of cancer patients, the full potential of nanoparticles in cancer therapy remains to be explored. Exciting developments in nanotechnology have allowed for the production of a wide variety of advanced nanoparticles.

One highly interesting development is the synthesis of so-called targeted nanoparticles: Nanoparticles equipped with molecules on their surface making them specifically recognise and accumulate in tumour tissue (Figure 1C). This is a very promising approach to deliver drugs specifically to tumours and to spare healthy tissue (Figure 1 D-E).

For the development and successful application of such targeted nanoparticles, detailed studies to learn about and understand the in vivo behaviour of these novel targeted nanoparticles are essential.

For example, it is not well known how fast targeted nanoparticles accumulate in tumour tissue after injection. Moreover, it is now becoming clear that certain nanoparticles readily disintegrate upon injection into the blood, resulting in drug release in the blood. As such, the drug may be released before the tumour is reached. Hence, knowledge of nanoparticle degradation and tumour targeting rates and dynamics are crucial for successful development and application of targeted nanoparticles. However, these dynamics remain largely unstudied, which may be compounded by the fact that suitable experimental in vivo tools to do so are lacking

Ultimately, we anticipate to fine-tune our nanoparticle design and increase their value in the battle against­­­ cancer.

Over the last four years, during my recently completed PhD project, we have established the synthesis of innovative nanoparticles of which such dynamics can be quantitatively monitored. Furthermore, combining in vivo microscopy and magnetic resonance imaging, we have developed a unique experimental set-up which is highly suitable to study in vivo nanoparticle dynamics.

Over the next years, this novel experimental approach will be exploited to study degradation and targeting dynamics of our nanoparticles at an unprecedented level of detail. Importantly, this will provide general knowledge applicable to a variety of targeted therapies. Ultimately, we anticipate to fine-tune our nanoparticle design and increase their value in the battle against­­­ cancer.