Researchers at the University of Arizona are developing a non-invasive brain-scanning technology that could produce images far superior to those obtained with the most commonly used systems – electroencephalography and functional magnetic resonance imaging.
The technique, which incorporates sound waves to measure electrical activity in neural tissue, could improve diagnosis and treatment of many disorders, including epilepsy, Parkinson’s disease and traumatic brain injury.
Russell Witte, a UA associate professor of medical imaging, biomedical engineering and optical sciences, is principal investigator of the research project.
‘We know very little about how neurons act collectively to guide our thoughts, emotions and behaviours – or cause seizures or mood swings,’ Witte said.
‘Functional magnetic resonance imaging and electroencephalography have provided some clues. But both fMRI and EEG share a major limitation: They produce images with poor resolution,’ he said. ‘We think our new technology could overcome that limitation.’
Researchers have long known of the acoustoelectric effect, in which ultrasound energy alters a material’s physical properties like electrical conductivity.
Witte is one of the first researchers to apply the phenomenon to biomedical imaging.
He has developed a non-invasive imaging technique for detecting irregular heartbeats and is working with Tech Launch Arizona, the UA office that commercializes inventions stemming from University research, to create a startup for acoustoelectric cardiac imaging.
With the new study, Witte takes his research into new terrain: the brain.
The research team will develop and test the non-invasive technology, called acoustoelectric brain imaging, or ABI, on mammalian brains for the first time.
ABI involves applying ultrasound waves externally to the brain, where they interact with electrical currents to produce a ‘signature’ wave that is picked up by an electrode attached outside the head. ABI can better localize the source of electrical activity than EEG, because it overcomes the problem of interference from the skull, and it works much faster than fMRI, which measures metabolic activity.
‘Sensory input, thoughts and behaviours are happening so fast,’ said Cowen, a neuroscientist.
‘With speech or motor activity, many actions require split-second decisions – actually, on the scale of tens of milliseconds,’ Cowen said. ‘If a brain-imaging technology is working only in seconds – fMRI, for example, can measure brain activity once every two seconds – it may be missing some of the most important details.’
Cowen added: ‘This is a very interesting adventure we’re undertaking, because nobody knows what ABI will actually measure. Will it measure the activity of tens of thousands, or hundreds of thousands, of neurons? Will it detect the activity at a specific frequency, or at a range of frequencies?’
ABI also could provide a clearer picture of activity in structures deep in the brain, such as the amygdala and hippocampus.

University of Arizona http://tinyurl.com/zw5f6he

The hormone oestrogen helps protect memory and promote a healthy brain, but this effect wanes as women age, and even estrogen replacement therapy stops working in humans after age 65. Now researchers at University of Florida Health have used gene therapy in a rat model to show that the expression of a particular receptor can reinstate lost memory function.
The scientists included Thomas C. Foster, Ph.D., a professor of neuroscience and the Evelyn F. McKnight chair for research on cognitive aging, and Linda A. Bean, Ph.D.
‘There is a window of time, starting around menopause, when initiation of hormone replacement therapy with estrogen protects the brain against injury and Alzheimer’s disease. However, this window seems to end around age 65,’ Foster said. ‘We wanted to find out what is regulating this window.’
The researchers used gene therapy to overexpress two different estrogen receptors found in the hippocampus, a part of the brain essential to memory regulation. They found that an abundance of one of these receptors, called alpha, reinstated memory in aging rats when paired with estrogen.
Estrogen helps to do this by increasing the brain’s ‘plasticity,’ which is the ability to form and maintain connections between brain cells as things are learned. As plasticity declines, so do the number of connections in the brain, and certain types of memories begin to fade. Without the protective effect of estrogen, women may lose brain plasticity and start forgetting things more often. The loss of estrogen’s protective effects may explain why women are more likely than men to develop dysfunctional memory problems such as Alzheimer’s disease.
The researchers looked at the effects on memory in six groups, which received gene therapy for expression of the alpha receptor, the beta receptor or a control gene. The three different gene therapy groups then received estrogen or a placebo for the next several weeks, until memory testing and examination of brain plasticity. The project involved 72 animals. Only the group with gene therapy for the alpha receptor plus estrogen showed any beneficial effects on memory and increased brain plasticity markers.
‘In the short term, this finding helps us understand how estrogen rescues memory and keeps the brain young and plastic,’ Foster said. ‘In the long term, this finding may eventually allow us to bypass estrogen and target the receptor or brain plasticity mechanisms directly.’

University of Florida Health http://tinyurl.com/qbkrmz9

The human body is controlled by electrical impulses in, for example, the brain, the heart and nervous system. These electrical signals create tiny magnetic fields, which doctors could use to diagnose various diseases, for example diseases of the brain or heart problems in young foetuses. Researchers from the Niels Bohr Institute have now succeeded in developing a method for extremely precise measurements of such ultra-small magnetic fields with an optical magnetic field sensor.

Small magnetic fields from the human body can usually only be picked up by very sensitive superconducting magnetic field sensors that have to be cooled by liquid helium to near absolute zero (which is minus 273 degrees Celsius). But now researchers from the Niels Bohr Institute at the University of Copenhagen have developed a much cheaper and more practical optical magnetic field sensor that even works at room temperature or at body temperature.

‘The optical magnetic field sensor is based on a gas of caesium atoms in a small glass container. Each caesium atom is equivalent to a small bar magnet, which is affected by external magnetic fields. The atoms and thus the magnetic field are picked up using laser light. The method is based on quantum optics and atomic physics and can be used to measure extremely small magnetic fields,’ explains Kasper Jensen, assistant professor in the Center for Quantum Optics, Quantop at the Niels Bohr Institute at the University of Copenhagen.

The researchers at the Niels Bohr Institute have been developing the sensitive magnetic field sensor for several years in the Quantum research group laboratories.

The magnetic field sensor itself consists of a glass container, which has a channel that is approximately 1cm long and 1 mm wide. At the bottom of the glass container is caesium metal. Caesium evaporates into gas at room temperature and the gas atoms rise up into the small channel in the sensor head. Each caesium atom rotates around itself and the axis is like a tiny bar magnet. Now the sensor is held close to a nerve, which emits an electrical nerve pulse. The electrical pulse has a magnetic field that causes a change in the tilt of the axes of the caesium atoms and by sending a laser beam through the gas, you can read the ultra-small magnetic fields of the nerve signals.

The laboratory tests, which were carried out in collaboration with researchers from the Faculty of Health and Medical Sciences, have shown that you can use the magnetic field sensor to detect the magnetic fields from the electrical impulses from the nervous system. The tests were done on the sciatic nerve from a frog, which in many ways resemble the nerves in the human body. For practical reasons, the nerve was removed from the frog before the tests, but it is also possible to pick up electrical impulses from live frogs or from humans.

The advantage of the optical sensor is precisely that the magnetic fields and electrical impulses can be safely and easily picked up at a distance of a few millimetres or centimetres – without the sensor actually coming into contact with the body.

‘We expect that the sensor will be used for special medical examinations, where it is important for the sensor not to be directly in contact with the body, for example, for diagnosing heart problems in tiny foetuses. Here the magnetic field sensor is placed on the mother’s abdomen and you can easily and safely detect the heartbeat of the foetus and you will be able to diagnose any heart problems at an early stage so that the foetus can get the right treatment quickly,’ explains Eugene Polzik, professor and head of Quantop at the Niels Bohr Institute.

University of Copenhagen Niels Bohr Institute news.ku.dk/all_news/2016/07/optical-magnetic-field-sensor-can-detect-signals-from-the-nervous-system/

Twice as many patients with non-serious injuries, such as fractures or neck strain, are undergoing CT scans in emergency departments at California hospitals, according to a UCSF-led study, which tracked the use of the imaging from 2005 to 2013.
While CT scans enable clinicians to swiftly pinpoint life-threatening conditions, exposure to its ionizing radiation is associated with an increased risk of cancer. According to a 2009 report by the FDA, a single CT scan may be associated with a fatal cancer in one in 2,000 patients.
In the study, researchers at UCSF and Stanford studied more than 8 million adult patient visits at 348 state hospitals, using data from the California Office of Statewide Health Planning and Development. These patients had been discharged after being seen in emergency departments for injuries such as minor falls or low-impact vehicle accidents. The study found that 3.51 percent of patients underwent at least one CT scan in 2005, versus 7.17 percent in 2013.
‘The reasons for this increase are multifactorial,’ said senior author Renee Hsia, MD, professor of emergency medicine and health policy at UCSF. ‘They range from defensive medicine practices, the superior diagnostic accuracy of CT scans compared with X-rays, to their increased availability and convenience in emergency departments, and the demand to expedite discharge of patients.’
The authors noted that CTs were more likely to be ordered in hospitals that were designated high-level trauma centres. Some 39 percent of those in the study were ordered at level I and II trauma centres, compared with 3 percent at low-level centres.
‘This may reflect an underlying work culture largely centred around the management of severely injured patients, guided by standard trauma CT protocols, and also the fact that level I and II trauma centres see sicker patients,’ the authors wrote in their paper.
Also disproportionately visible were patients between the ages of 18 and 24, ‘those at greatest risk for radiation,’ wrote the authors, as well as those over 45. ‘With the aging of the U.S. population, physicians may be influenced toward greater advanced imaging even in the case of low-mechanism injuries, given the atypical presentations and more serious pathology that older adults may have,’ said Hsia.
The authors reported an upswing in the use of CTs from 2005 to 2009, followed by a gradual decline to 2011 – reflecting awareness of overuse – which was preceded by a resurgence from 2011 to 2013 that almost reached the zenith of 2009.
‘The message for both patients and physicians is that there are long-term risks associated with radiation exposure and there may be situations where imaging is not definitively warranted or beneficial,’ said Hsia.

University of California – San Francisco http://tinyurl.com/hp4525h

UHCW pathologist David Snead and scientists in Coventry are now using technology that could revolutionize how some cancers are diagnosed.
A high-tech computer system is able to read samples of human tissue and aid pathologists in the identification of minute changes in cells that can indicate cancer is present. More than 10,000 slides were examined in the first phase of the study which shows that pathologists are as good at accurately diagnosing cancer on a computer as they are with a microscope.
The ground breaking technology has the power to help pathologists grade some types of tumours, including lung, prostate and bladder tumours with precision. In prostate cancer, for example, this could make the difference between someone being offered surgery rather than drug based treatments.
The computer system known as The Omnyx Precision Solution, can help pathologists to see the small differences in cells in the same way that they have currently been using a microscope, allowing them to make sound decisions on many aspects of cancer diagnosis.
The Omnyx system digitizes slides which are traditionally placed on a microscope so that pathologists can look at them on a computer. Once on the computer, the UHCW scientists have written programmes which will separate normal from abnormal samples.
David Snead said: ‘I am delighted that University Hospital, Coventry has led this ground breaking study. This provides even greater evidence that digital pathology really works, and works well. The introduction of digital pathology has fantastic potential benefits for patients. We can expect to be able to read samples more quickly than before, and the big advantage is that we can use the computer to easily manipulate an image or its data. For some patients, this additional information may change how their disease is managed.’

University Hospitals Coventry http://tinyurl.com/gw4c993