Tuesday, November 6, 2018

Early diagnosis of Alzheimer's disease using artificial intelligence

According to a study published in the journal of radiology, research shows that artificial intelligence (AI) technology predict the development of Alzheimer's disease early.

Early diagnosis of Alzheimer's is important as treatments and interventions are more effective early in the course of the disease. However, early diagnosis has proven to be challenging. Research has linked the disease process to changes in metabolism, as shown by glucose uptake in certain regions of the brain, but these changes can be difficult to recognize.

Credit: Radiological Society of North America
"Differences in the pattern of glucose uptake in the brain are very subtle and diffuse," said study co-author Jae Ho Sohn, M.D., from the Radiology & Biomedical Imaging Department at the University of California in San Francisco (UCSF). "People are good at finding specific biomarkers of disease, but metabolic changes represent a more global and subtle process."

The researchers trained the deep learning algorithm on a special imaging technology known as 18-F-fluorodeoxyglucose positron emission tomography (FDG-PET). In an FDG-PET scan, FDG, a radioactive glucose compound, is injected into the blood. PET scans can then measure the uptake of FDG in brain cells, an indicator of metabolic activity.

The researchers had access to data from the Alzheimer's Disease Neuroimaging Initiative (ADNI), a major multi-site study focused on clinical trials to improve the prevention and treatment of this disease. The ADNI dataset included more than 2,100 FDG-PET brain images from 1,002 patients. Researchers trained the deep learning algorithm on 90 percent of the dataset and then tested it on the remaining 10 percent of the dataset. Through deep learning, the algorithm was able to teach itself metabolic patterns that corresponded to Alzheimer's disease.

Finally, the researchers tested the algorithm on an independent set of 40 imaging exams from 40 patients that it had never studied. The algorithm achieved 100 percent sensitivity at detecting the disease an average of more than six years prior to the final diagnosis.

"We were very pleased with the algorithm's performance," Dr. Sohn said. "It was able to predict every single case that advanced to Alzheimer's disease."

Although he cautioned that their independent test set was small and needs further validation with a larger multi-institutional prospective study, Dr. Sohn said that the algorithm could be a useful tool to complement the work of radiologists especially in conjunction with other biochemical and imaging tests--in providing an opportunity for early therapeutic intervention.

Future research directions include training the deep learning algorithm to look for patterns associated with the accumulation of beta-amyloid and tau proteins, abnormal protein clumps and tangles in the brain that are markers specific to Alzheimer's disease, according to UCSF's Youngho Seo, Ph.D., who served as one of the faculty advisors of the study.

Citation: Yiming Ding, Jae Ho Sohn, Michael G. Kawczynski, Hari Trivedi, Roy Harnish, Nathaniel W. Jenkins, Dmytro Lituiev, Timothy P. Copeland, Mariam S. Aboian, Carina Mari Aparici, Spencer C. Behr, Robert R. Flavell, Shih-Ying Huang, Kelly A. Zalocusky, Lorenzo Nardo, Youngho Seo, Randall A. Hawkins, Miguel Hernandez Pampaloni, Dexter Hadley, and Benjamin L. Franc. "A Deep Learning Model to Predict a Diagnosis of Alzheimer Disease by Using 18F-FDG PET of the Brain." Radiology, 2018, 180958.
doi:10.1148/radiol.2018180958.



Monday, November 5, 2018

Keep up with your weight loss goals with daily weighing

According to research presented in the American Heart Association's 2018 scientific meeting, daily weighing may help with weight loss goals. People who don't weigh themselves at all or rarely were less likely to lose weight than those who weighed themselves often,

Researchers examined the self-weighing patterns of 1,042 adults (78 percent male, 90 percent white, average age 47) and whether there were differences in weight change by these self-weighing patterns over 12 months. They analyzed remotely transmitted self-weighing data from Health eHeart, an ongoing prospective e-cohort study. The participants weighed themselves at home as they normally would, without interventions, guidance or weight-loss incentives from researchers.

Researchers identified several categories of self-weighing adults, from those that weighed themselves daily or almost daily to adults who never used at-home scales.

They found that people who never weighed themselves or only weighed once a week did not lose weight in the following year. Those that weighed themselves six to seven times a week had a significant weight loss (1.7 percent) in 12 months.

Citation: Daily weighing may be key to losing weight
American Heart Association Meeting  Poster Presentation Sa2394 – Session: NR.APS.01
Yaguang Zheng, Ph.D., M.S.N., R.N., University of Pittsburgh School of Nursing, Pittsburgh, PA

Tuesday, October 30, 2018

Quantum dot technology to advance molecular cell imaging

Researchers from the University of Illinois at Urbana-Champaign bioengineering team and Mayo Clinic have engineered a new type of molecular probe that can measure and count RNA in cells and tissue without organic dyes. The probe is based on the conventional fluorescence in situ hybridization (FISH) technique, but it relies on compact quantum dots to illuminate molecules and diseased cells rather than fluorescent dyes. This research is published in Nature Communications.

Quantum dots illuminate the locations of individual mRNA as red dots in the cytoplasm of a single HeLa cell. The blue region is the nucleus.  Credit: University of Illinois at Urbana-Champaign Department of Bioengineering
Over the last 50 years, fluorescence in situ hybridization technique has evolved into a multi-billion-dollar industry because it effectively images and counts DNA and RNA in single cells. However, fluorescence in situ hybridization technique has its limitations due to the delicate nature of the dyes. For example, the dyes rapidly deteriorate and are not very good at imaging in three dimensions. In addition, conventional fluorescence in situ hybridization technique can only read out a couple of RNA or DNA sequences at a time. Using quantum dots, however, can illuminate the locations of individual mRNA as red dots in the cytoplasm of a single HeLa cell.

The team created unique quantum dots that are made of a zinc, selenium, cadmium, and mercury alloy and are coated with polymers. "The core of the dot dictates the wavelength of emission, and the shell dictates how much light will be given off," said Smith, who is also affiliated with the Micro + Nanotechnology Lab, Carle Illinois College of Medicine, and Department of Materials Science and Engineering at the University of Illinois.

These dots can emit color independent of the size of the particle, which is not the case for conventional quantum dots. The dots are also small enough (7 nanometers) to fit on a probe that can maneuver between proteins and DNA in a cell, making them more comparable in size to the dyes used in conventional FISH probes.

In experiments with HeLa cells and prostate cancer cells, the researchers found that dye-based FISH cell counts declined rapidly in minutes. The quantum dot-based FISH method provided long-term luminescence to allow counting of RNA for more than 10 minutes, making it possible to acquire 3D cell imaging.

Citation: Liu, Yang, Phuong Le, Sung Jun Lim, Liang Ma, Suresh Sarkar, Zhiyuan Han, Stephen J. Murphy, Farhad Kosari, George Vasmatzis, John C. Cheville, and Andrew M. Smith. "Enhanced mRNA FISH with Compact Quantum Dots." Nature Communications 9, no. 1 (2018). doi:10.1038/s41467-018-06740-x.

Monday, October 29, 2018

New vaccine shown promise in preventing secondary strokes after an ischemic stroke

New research published in journal Hypertension shows that vaccine called S100A9 may be able to replace oral blood thinners to reduce the risk of secondary strokes in patients with recent ischemic stroke.

Japanese researchers successfully tested an experimental vaccine in mice and found that it provided protection against blood clots for more than two months without increasing the risk of bleeding or causing an autoimmune response.

The vaccine, S100A9, inhibits blood clot formation and, during the study, protected the arteries of treated mice from forming new clots for more than two months, and additionally, worked as well as the oral blood thinner clopidogrel in a major artery, according to Hironori Nakagami, M.D., Ph.D., study co-author and professor at Osaka University, in Japan.

"Many stroke patients don't take their blood thinning drugs as prescribed, which makes it more likely they will have another stroke. This vaccine might one day help solve this issue since it would only need to be injected periodically," Nakagami said.

Citation: Tomohiro Kawano, M.D.; Munehisa Shimamura, M.D., Ph.D.; Tatsuya Iso, M.D., Ph.D.; Hiroshi Koriyama, M.D., Ph.D.; Shuko Takeda; Tsutomu Sasaki, M.D., Ph.D.; Manabu Sakaguchi, M.D., Ph.D.; Ryuichi Morishita, M.D., Ph.D.; and Hideki Mochizuki, M.D., Ph.D.
https://doi.org/10.1161/STROKEAHA.118.022837



Friday, October 26, 2018

Late night snack with cottage cheese has no major adverse metabolic effects

Associate Professor of Nutrition, Food and Exercise Sciences Michael Ormsbee and former Florida state university graduate student Samantha Leyh found that consuming 30 grams of protein about 30 minutes before bed appears to have a positive effect on muscle quality, metabolism, and overall health. They compared protein from whole food (cottage cheese) versus liquid protein shake and placebo. In their results they showed no difference between whole food and liquid protein shake in terms of appetite and metabolic changes. Research suggests that no adverse impact of pre-sleep protein on metabolic activity. Research findings are published in the British Journal of Nutrition.

Study participants active young women in their early 20s ate samples of cottage cheese 30 to 60 minutes before bedtime. Researchers specifically wanted to see if this food may have an impact on the metabolic rate and muscle recovery.

"Until now, we presumed that whole foods would act similarly to the data on supplemental protein, but we had no real evidence," Ormsbee said. "This is important because it adds to the body of literature that indicates that whole foods work just as well as protein supplementation, and it gives people options for presleep nutrition that go beyond powders and shaker bottles."

Leyh, who is now a research dietitian with the Air Force, said the results serve as a foundation for future research on precise metabolic responses to whole food consumption.

Ormsbee said that his research team will start examining more presleep food options and longer-term studies to learn more about the optimal food choices that can aid individuals in recovery from exercise, repair and regeneration of muscle and overall health.

Citation:Leyh, Samantha M., Brandon D. Willingham, Daniel A. Baur, Lynn B. Panton, and Michael J. Ormsbee. "Pre-sleep Protein in Casein Supplement or Whole-food Form Has No Impact on Resting Energy Expenditure or Hunger in Women." British Journal of Nutrition120, no. 9 (2018): 988-94. doi:10.1017/s0007114518002416.

Tuesday, March 27, 2018

Preventing Alzheimer's dementia with Ibuprofen

Researchers suggest that daily intake of nonsteroidal anti-inflammatory drugs like over the counter ibuprofen could prevent the onset of Alzheimer's disease. This research is led by Dr. Patrick McGeer and is published in the Journal of Alzheimer's Disease.

Alzheimer's dementia affects those diagnosed and their family along with a significant financial burden on the society. It is estimated around 47 million people worldwide are affected by this and is the fifth leading cause of death in those aged 65 and above. The Alzheimer's Association estimates that there are more than 5 million cases in the United States alone. The annual cost United States in 2017 is estimated to be around $259 billion and the projected for the costs go to 1.1 trillion by 2050.

According to the latest publication by Dr. Patrick McGeer diagnosis of people at risk of Alzheimer's disease is possible with positron-electron microscopy for AD senile plaques, blood or saliva analysis for the elevation of the amyloid-β protein fragment terminating at position 42, and cerebrospinal fluid analysis showing a decrease in the content of this protein. The publication also suggests prevention strategies like self-treatment by consumption of non-steroidal anti-inflammatory drugs, adhering to a Mediterranean diet, and consuming antioxidants such as quercitin which is contained in coffee.

Reference: Mcgeer, Patrick L., and Edith Mcgeer. "Conquering Alzheimer’s Disease by Self Treatment." Journal of Alzheimers Disease, 2018, 1-3. doi:10.3233/jad-179913.

Adapted from press release by IOS press.

Saturday, March 24, 2018

Improvements in optical mammography to advance breast cancer diagnostics

Researchers from Politecnico di Milano, Italy report improvements in the design of optical mammography used in diagnosis and monitoring of breast cancer.  They report increase sensitivity by a thousandfold.This research is presented at Biomedical Optics meeting 2018.

Schematic diagram of new and improved optical mammography device.
Credit: Edoardo Ferocino
Optical mammography uses infrared light and is used in conjunction with x-rays. It is optimal in cases needing repeated imaging to prevent high amounts of radiation associated with the regular procedure. Optical mammography can be used to measure blood volume, oxygenation, lipid, water and collagen content for a suspicious area identified through standard X-ray imaging. However, there are limitations to using optical mammography, which includes poor spatial resolution.

New improvements include using eight channel silicon photomultipliers (SiPMs) and multichannel time-to-digital converter instead of two photomultiplier tubes (PMTs) in existing optical mammography instruments. These changes eliminate the pre-scan step that was required to avoid damage to the photomultiplier tubes. In addition to increased sensitivity, the new instrument is both more robust and cheaper.

The investigators in Milan are working with a larger consortium on a project known as SOLUS, "Smart Optical and Ultrasound Diagnostics of Breast Cancer." This project is funded by the European Union through the Horizon 2020 Research and Innovation Program and aims to combine optical imaging methods with ultrasound to improve specificity in the diagnosis of breast cancer.

Adapted from press release by the Optical Society.

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