Cedars-Sinai neuroscience investigators have found that Alzheimer’s disease affects the retina – the back of the eye – similarly to the way it affects the brain. The study also revealed that an investigational, non-invasive eye scan could detect the key signs of Alzheimer’s disease years before patients experience symptoms.
Using a high-definition eye scan developed especially for the study, researchers detected the crucial warning signs of Alzheimer’s disease: amyloid-beta deposits, a buildup of toxic proteins. The findings represent a major advancement toward identifying people at high risk for the debilitating condition years sooner.
The study comes amid a sharp rise in the number of people affected by the disease. Today, more than 5 million Americans have Alzheimer’s disease. That number is expected to triple by 2050, according to the Alzheimer’s Association.
“The findings suggest that the retina may serve as a reliable source for Alzheimer’s disease diagnosis,” said the study’s senior lead author, Maya Koronyo-Hamaoui, PhD, a principal investigator and associate professor in the departments of Neurosurgery and Biomedical Sciences at Cedars-Sinai.
“One of the major advantages of analysing the retina is the repeatability, which allows us to monitor patients and potentially the progression of their disease.”
Yosef Koronyo, MSc, a research associate in the Department of Neurosurgery and first author on the study, said another key finding from the new study was the discovery of amyloid plaques in previously overlooked peripheral regions of the retina. He noted that the plaque amount in the retina correlated with plaque amount in specific areas of the brain.
“Now we know exactly where to look to find the signs of Alzheimer’s disease as early as possible,” said Koronyo.
Keith L. Black, MD, chair of Cedars-Sinai’s Department of Neurosurgery and director of the Maxine Dunitz Neurosurgical Institute, who co-led the study, said the findings offer hope for early detection when intervention could be most effective.
“Our hope is that eventually the investigational eye scan will be used as a screening device to detect the disease early enough to intervene and change the course of the disorder with medications and lifestyle changes,” said Black.

newswise
www.newswise.com/articles/noninvasive-eye-scan-could-detect-key-signs-of-alzheimer-s-disease-years-before-patients-show-symptoms
 

A team of engineering and medical researchers has found a way to use ultrasound to monitor fluid levels in the lung, offering a non-invasive way to track progress in treating pulmonary edema – fluid in the lungs – which often occurs in patients with congestive heart failure. The approach, which has been demonstrated in rats, also holds promise for diagnosing scarring, or fibrosis, in the lung.
“Historically, it has been difficult to use ultrasound to collect quantitative information on the lung, because ultrasound waves don’t travel through air– and the lung is full of air,” says Marie Muller, an assistant professor of mechanical engineering at North Carolina State University and co-author of a paper on the work. “However, we’ve been able to use the reflective nature of air pockets in the lung to calculate the amount of fluid in the lung.”
When ultrasound waves travel through the body, most of each wave’s energy passes through the tissue. But some of that energy is reflected as an echo. By monitoring these echoes, an ultrasound scanner is able to create an image of the tissue that the waves passed through. All of this happens in microseconds.
But when ultrasound waves hit air, all of the energy is reflected – which is why ultrasound images of the lung tend to look like a big, grey blob, with little useful information for healthcare providers. And while there are some techniques that allow users to determine if a patient has pulmonary edema, those techniques still can’t tell how much fluid there is.
This is where Muller’s team comes in.
When ultrasound waves hit air pockets in the lung, or alveoli, they scatter. Those scattered waves hit other air pockets, scattering them further. This process of bouncing around means that it takes an ultrasound’s echo much longer to bounce back to the ultrasound machine – though it’s still measured in microseconds. And that is why the lung looks like a grey blob to the ultrasound scanner.
But no two ultrasound waves take the same path – they may bounce in different directions as they travel through the lung. So their echoes take different amounts of time to return to the scanner. By looking at all of the echoes, and how those echoes change over time, Muller and her collaborators were able to calculate the extent to which the space between the air pockets was filled with fluid.
To test their approach, the researchers conducted two sets of experiments using rats and rat lung tissue.
In the first set of experiments, researchers used rat lung tissue that had been injected with saline solution to mimic fluid-filled lung tissue. The new approach allowed researchers to quantify the amount of fluid in the lung to within one milliliter.
In the second set of experiments, researchers found significant differences between fluid-filled and healthy lungs in rats. Specifically, the researchers were calculating the mean distance between two “scattering events” – or how far an ultrasound wave travelled between two air pockets.
For fluid-filled lungs, the mean distance was 1,040 micrometers, whereas the mean distance in healthy lungs was only 332 micrometers.
“This is important, because one could potentially track this mean distance value as a way of determining how well pulmonary edema treatment is working,” Muller says.
The technique makes use of conventional ultrasound scanning equipment, though the algorithm used by the researchers would need to be incorporated into the ultrasound software.

North Carolina State Universityhttp://tinyurl.com/ycktwghh 

One downside to medical sensors that test human sweat: You have to sweat. Sweating from exertion or a stifling room temperature can be impractical for some patients and unsafe for others. And unless they are on the second leg of the Tour de France, it’s unlikely patients will want to sweat all day for the benefit of a sensor reading.
But researchers at the University of Cincinnati have come up with a novel way to stimulate sweat glands on a small, isolated patch of skin so subjects can stay cool and comfortable and go about their daily routine without spending hours on a treadmill.
UC professor Jason Heikenfeld and UC graduate Zachary Sonner came up with a device the size of a Band-Aid that uses a chemical stimulant to produce sweat, even when the patient is relaxed and cool. The sensors also can predict how much patients sweat, an important factor in understanding the hormones or chemicals the biosensors measure.
"Doctors would love to know if chemical concentrations are increasing or decreasing over time," Heikenfeld said. "What was your baseline before you got sick? Then by measuring the change in concentrations, we know even more about how sick you are or how quickly you are getting better."
Blood analysis is considered the gold standard for biometric analysis. But biometric testing with blood is invasive and often requires the use of a lab. It is far more difficult for doctors to perform continuous monitoring of blood over hours or days.
Sweat provides a non-invasive alternative, with chemical markers that are more useful in monitoring health than saliva or tears, Heikenfeld said.
“People for a long time ignored sweat because, although it can be a higher-quality fluid for biomarkers, you can’t rely on having access to it,” Heikenfeld said. “Our goal was to achieve methods to stimulate sweat whenever needed — or for days.”
Scientists say sweat provides much of the same useful information about patients as blood. The problem has always been getting the same consistent sample as is possible with a standard blood draw, he said.
For the study, the researchers applied sensors and a gel containing carbachol, a chemical used in eyedrops, to their subject’s forearm for 2.5 minutes.
They used three methods to obtain sensor data: the gel and sensors alone and in combination with memory foam padding (to provide better contact between the sensor and the skin) and iontophoresis, an electrical current at 0.2 milliamps that drives a tiny amount of carbachol into the upper layer of the skin and locally stimulates sweat glands but causes no physical sensation or discomfort.
Then they recorded data obtained from the subject’s sweat for 30 minutes using sensors that measured concentrations of sweat electrolytes. Carbachol was effective at inducing sweating under the sensor for as long as five hours. Heikenfeld said a subsequent study successful generated sensor results for several days using this process to stimulate sweat.
They used a pH-sensitive dye to observe the results. The orange dye turned blue when it reacted with sweat. This demonstrated that the sweat glands were stimulated evenly across the sensor area.
“This work represents a significant leap forward in sweat-sensing technology,” the study concluded.

University of Cincinnati
magazine.uc.edu/editors_picks/recent_features/Sweat.html

A multidisciplinary group that includes the University of Illinois at Urbana-Champaign and the University of Washington at Tacoma has developed a novel platform to diagnose infectious disease at the point-of-care, using a smartphone as the detection instrument in conjunction with a test kit in the format of a credit card. The group is led by Illinois Electrical and Computer Engineering  Professor Brian T. Cunningham; Illinois Bioengineering Professor Rashid Bashir; and, University of Washington at Tacoma Professor David L. Hirschberg, who is affiliated with Sciences and Mathematics, division of the School of Interdisciplinary Arts and Sciences.
Findings have demonstrated detection of four horse respiratory diseases, and in Biomedical Microdevices, where the system was used to detect and quantify the presence of Zika, Dengue, and Chikungunya virus in a droplet of whole blood. Project collaborators include Dr. David Nash, a private practice equine expert and veterinarian in Kentucky, and Dr. Ian Brooks, a computer scientist at the National Center for Supercomputing Applications.
The low-cost, portable, smartphone-integrated system provides a promising solution to address the challenges of infectious disease diagnostics, especially in resource-limited settings or in situations where a result is needed immediately. The diagnostic tool’s integration with mobile communications technology allows personalized patient care and facilitates information management for both healthcare providers and epidemiological surveillance efforts. Importantly, the system achieves detection limits comparable to those obtained by laboratory-based methods and instruments, in about 30 minutes.
A useful capability for human point-of-care (POC) diagnosis or for a mobile veterinary laboratory, is to simultaneously test for the presence of more than one pathogen with a single test protocol, which lowers cost, saves time and effort, and allows for a panel of pathogens, which may cause similar symptoms, to be identified.
Infectious diseases remain the world’s top contributors to human death and disability, and with recent outbreaks of Zika virus infections, there is a keen need for simple, sensitive, and easily translatable point-of-care tests. Zika virus appeared in the international spotlight in late 2015 as evidence emerged of a possible link between an epidemic affecting Brazil and increased rates of microcephaly in newborns. Zika has become a widespread global problem—the World Health Organization (WHO) documented last year that since June 2016, 60 nations and territories report ongoing mosquito-borne transmission. Additionally, since Zika virus infection shares symptoms with other diseases such as Dengue and Chikungunya, quick, accurate diagnosis is required to differentiate these infections and to determine the need for aggressive treatment or quarantine.
The technology is intended to enable clinicians to rapidly diagnose disease in their office or in the field, resulting in earlier, more informed patient management decisions, while markedly improving the control of disease outbreaks. An important prerequisite for the widespread adoption of point-of-care tests at the patient’s side is the availability of detection instruments that are inexpensive, portable, and able to share data wirelessly over the Internet.
The system uses a commercial smartphone to acquire and interpret real-time images of an enzymatic amplification reaction that takes place in a silicon microfluidic chip that generates green fluorescence and displays a visual read-out of the test. The system is composed of an unmodified smartphone and a portable 3D–printed cradle that supports the optical and electrical components, and interfaces with the rear-facing camera of the smartphone.
The software application operating on the smartphone gathers information about the tests conducted on the microfluidic card, patient-specific information, and the results from the assays, that are then communicated to a cloud storage database.
Dr. Nash observes that, “This project is a game changer. This is the future of medicine—empowered front-line healthcare professionals. We can’t stop viruses and bacteria, but we can diagnose more quickly. We were able to demonstrate the clear benefit to humankind, as well as to animals, during the proposal phase of the project, and our results have proved our premise.

University of Illinois
mntl.illinois.edu/news/article/23759