Can We Sort Cancer Cells with Sound Waves?

What You Need to Know: Researchers from MIT, Pennsylvania State University, and Carnegie Mellon University have devised a new way to separate cells by exposing them to sound waves as they flow through a tiny channel. Their device, about the size of a dime, could be used to detect the extremely rare tumor cells that circulate in cancer patients’ blood, helping doctors predict whether a tumor is going to spread. Separating cells with sound offers a gentler alternative to existing cell-sorting technologies, which require tagging the cells with chemicals or exposing them to stronger mechanical forces that may damage them.

“Acoustic pressure is very mild and much smaller in terms of forces and disturbance to the cell. This is a most gentle way to separate cells, and there’s no artificial labeling necessary,” says Ming Dao, a principal research scientist in MIT’s Department of Materials Science and Engineering and one of the senior authors of the paper, which appears this week in the Proceedings of the National Academy of Sciences.’

How They Do It: To sort cells using sound waves, scientists have previously built microfluidic devices with two acoustic transducers, which produce sound waves on either side of a microchannel. When the two waves meet, they combine to form a standing wave (a wave that remains in constant position). This wave produces a pressure node, or line of low pressure, running parallel to the direction of cell flow. Cells that encounter this node are pushed to the side of the channel; the distance of cell movement depends on their size and other properties such as compressibility.

However, these existing devices are inefficient: Because there is only one pressure node, cells can be pushed aside only short distances.
The new device overcomes that obstacle by tilting the sound waves so they run across the microchannel at an angle — meaning that each cell encounters several pressure nodes as it flows through the channel. Each time it encounters a node, the pressure guides the cell a little further off center, making it easier to capture cells of different sizes by the time they reach the end of the channel.

This simple modification dramatically boosts the efficiency of such devices, says Taher Saif, a professor of mechanical science and engineering at the University of Illinois at Urbana-Champaign. “That is just enough to make cells of different sizes and properties separate from each other without causing any damage or harm to them,” says Saif, who was not involved in this work.

My Take: Circulating tumor cells in clinical settings are very rare: A 1-milliliter sample of blood may contain only a few tumor cells. If we can detect these rare circulating tumor cells, we may be able to study their biology and determine whether the patient is at a high risk for the cancer taking hold in organs such as the liver, lungs, bones, or brain. While not ready for clinical use, this method is a move in the direction of better detecting circulating tumor cells in the body. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Fight Prostate Cancer with a Tomato-Rich Diet

What You Need to Know: New research suggests that men who eat over 10 portions a week of tomatoes have an 18 percent lower risk of developing prostate cancer. Prostate cancer is the second most common cancer in men worldwide. Rates are higher in developed countries, which some experts believe is linked to a Westernised diet and lifestyle.

The Evidence:  To assess if following diet and lifestyle recommendations reduces risk of prostate cancer, researchers at the Universities of Bristol, Cambridge and Oxford (England) looked at the diets and lifestyles of 1,806 men aged between 50 and 69 with prostate cancer and compared them with 12,005 cancer-free men. The study is the first study of its kind to develop a prostate cancer ‘dietary index’ which consists of dietary components — selenium, calcium and foods rich in lycopene — that have been linked to prostate cancer.

Men who had optimal intake of these three dietary components had a lower risk of prostate cancer. Tomatoes and its products — such as tomato juice and baked beans — were shown to be most beneficial, with an 18 per cent reduction in risk found in men eating over 10 portions a week.

My Take: The reduction in risk may be due to lycopene, an antioxidant that makes tomatoes and watermelon red in color. Lycopenes may help fight off toxins that can cause damage to your DNA (genes). Tomatoes may reduce the risk of prostate cancer among men, and should be considered as a part of a diet containing a wide variety of fruits, vegetables, and fiber. And don’t forget the physical activity and maintenance of a good weight (e.g. body mass index 20-25). I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: V. Er, J. Athene Lane, R. M. Martin, P. Emmett, R. Gilbert, K. N. L. Avery, E. Walsh, J. L. Donovan, D. E. Neal, F. C. Hamdy, M. Jeffreys. Adherence to dietary and lifestyle recommendations and prostate cancer risk in the Prostate Testing for Cancer and Treatment (ProtecT) trial. Cancer Epidemiology Biomarkers & Prevention, 2014; DOI: 10.1158/1055-9965.EPI-14-0322

 

 

Exercise Lowers Chances of Getting Breast Cancer

What You Need to Know: Postmenopausal women who in the past 4 years who have undertaken regular physical activity (equivalent to at least 4 hours walking per week) had a lower risk for invasive breast cancer.

The Study: Fournier and colleagues analyzed data from biennial questionnaires completed by 59,308 postmenopausal women who were enrolled in E3N, the French component of the European Prospective Investigation Into Cancer and Nutrition (EPIC) study. The mean duration of follow-up was 8.5 years, during which time 2,155 women were found to have a first primary invasive breast cancer.

Results: Postmenopausal women who in the previous 4 years had undertaken 12 or more MET-h (metabolic equivalent task-hours; roughly equivalent to at least 4 hours walking per week) had a 10% decreased risk of invasive breast cancer compared with women who were less active. 

My Take: It is not necessary to engage in vigorous or very frequent exercise; even walking 30 minutes per day seems beneficial. Keep moving, as you may reduce your own risk of cancer, diabetes, high blood pressure, heart attack, stroke, or even dementia! I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: Cancer Epidemiology, Biomarkers & Prevention 2014; doi:10.1158/1055-9965.EPI-14-0150.

 

Low Vitamin D Tied to Alzheimer’s Risk

What You Need to Know: Researchers have found that low vitamin D is associated with an increased risk for Alzheimer’s disease, and other forms of dementia. We do not yet know if low vitamin D is a cause of the disorders, however.

The Study: Scientists measured blood levels of vitamin D in 1,658 men and women, average age 73, without dementia at the start of the study. Over an average follow-up of more than five years, 171 developed dementia. Researchers controlled for age, education, sex,body mass index, smoking, alcohol use, diabetes, and hypertension.

Compared with those with vitamin D levels of 50 or more:

  • those with vitamin D levels of 25 to 50 had a 1.53x increased risk for all-cause dementia and a 69 percent increased risk for Alzheimer’s disease;
  • those with vitamin D levels of 25 or less are more than twice as likely to have Alzheimer’s or another form of dementia.

My Take: There is not consensus regarding what constitutes an ideal vitamin D level. The US National Institutes of Health considers levels below 50 as inadequate. Unfortunately, studies like the one I am presenting are only observational (but suggestive). I do not have a strong view about ideal vitamin D levels, and think that a one size fits all definition is a bit silly (your D levels will vary by age, skin color, where you live, whether you work inside or outside, etc.). I personally take 2,000 IU of vitamin D3 daily, as I have not seem harm from such intake, and I live in a place that does not have a lot of sun much of the year (although summer is absolutely glorious in Seattle). I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: Thomas J. Littlejohns, William E. Henley, Iain A. Lang, Cedric Annweiler, Olivier Beauchet, Paulo H.m. Chaves, Linda Fried, Bryan R. Kestenbaum, Lewis H. Kuller, Kenneth M. Langa, Oscar L. Lopez, Katarina Kos, Maya Soni, and David J. Llewellyn. Vitamin D and the risk of dementia and Alzheimer disease. Neurology, August 2014 DOI: 10.1212/WNL.0000000000000755