Researchers develop laser technology to fight cancer

Researchers have developed a technology that goes on a “seek and destroy” mission for cancerous tumors. They have harnessed the power of lasers to find, map and non-invasively destruct cancerous tumors.

Christian Parigger, associate professor of physics, and Jacqueline Johnson, associate professor of mechanical, aerospace, and biomedical engineering, along with Robert Splinter of Splinter Consultants, have developed the invention. The technology uses a femtosecond laser, which means it pulses at speeds of one-quadrillionth of a second. The high speed enables the laser to focus in on a specific region to find and acutely map a tumor.

“Using ultra-short light pulses gives us the ability to focus in a well confined region and the ability for intense radiation,” said Parigger.

“This allows us to come in and leave a specific area quickly so we can diagnose and attack tumorous cells fast.” Once the cancerous area is precisely targeted, only the intensity of the laser radiation needs to be turned up in order to irradiate, or burn off, the tumor.

This method has the potential to be more exact than current methods and to be done as an outpatient procedure replacing intensive surgery.

“Because the femtosecond laser radiation can be precisely focused both spatially and temporally, one can avoid heating up too many other things that you do not want heated,” said Parigger. “Using longer laser-light pulses is similar to leaving a light bulb on, which gets warm and can damage healthy tissue.”

The technology can be especially helpful to brain cancer oncology victims. The imaging mechanism can non-invasively permeate thin layers of bone, such as the skull, and can help define a targeted treatment strategy for persistent cancer. The method also overcomes limitations posed by current treatments in which radiation may damage portions of healthy brain tissue.

It also may overcome limitations of photodynamic therapy that has restricted acceptance and surgery that may not be an option if not all carcinogenic tissue can be removed.

“If you have a cancerous area such as in the brain, the notion is if you see something and take care of it, it won't spread,” said Parigger. “This treatment overcomes difficulties in treating brain cancer and tumors. And it has the promise of application to other areas, as well.”

The researchers are working to bring their technology to market with the University of Tennessee Research Foundation, a non profit corporation responsible for commercializing the university's technologies and supporting UT research.

- MNT

Restitution vs apology in forgiveness

People are more likely to show forgiving behaviour if they receive restitution, but they are more prone to report they have forgiven if they get an apology, according to new research.

The study underscores the importance of both restitution and apology and of using multiple measures for forgiveness, including behaviour, said Jo-Ann Tsang, an associate professor of psychology and neuroscience.

“One of the main reasons for using behavioural measures in addition to self-reporting by individuals is that they can make themselves look better by only self-reporting, although they don't necessarily intend to lie,” she said. “And it may be that ‘I forgive you’ is a more conscious feeling if they receive an apology.”

In the study, 136 undergraduate psychology students were stationed in individual cubicles and told that raffle tickets for a $50 gift card would be given out in three rounds, with 10 tickets per round to be divided between a participant and a unknown “partner.” They also were told they might receive a note from the partner.

In the first round, participants were given only two of the 10 tickets split between them and their partners; in the second, they got nine. Some were told the distributions were made by the partner; others were told it was by chance.

Some participants received an apology note from their partners on the second round, saying, “Sorry about that first round. I got carried away, and I feel really bad that I did that.” Some participants also received raffle tickets back from their partners in the second round, a form of restitution.

In the last round, the participants were given the chance to be in charge of distributions themselves. Researchers examined the links between apology, restitution, empathy and forgiveness, measuring forgiveness in two ways: Through behaviour (how many raffle tickets participants gave to their partners on the third round); and self-reporting on a questionnaire, with participants telling how highly they rated their motivation to forgive.

Researchers wrote that “making amends can facilitative forgiveness, but not all amends can fully compensate for offenses.” Apology may be needed to repair damage fully, but it may be a “silent forgiveness,” while restitution without apology may lead to a “hollow forgiveness” in which the offenders are treated better but not necessarily forgiven.

“The results suggest that if transgressors seek both psychological and interpersonal forgiveness from their victims, they must pair their apologies with restitution,” they wrote.

“Apparently, actions and words speak loudest in concert.”

- psychone.net

Ginseng-fortified milk developed to improve cognitive function

American ginseng is reported to have neurocognitive effects, and research has shown benefits in aging, central nervous system disorders, and neurodegenerative diseases. The challenges of incorporating ginseng into food are twofold: it has a bitter taste, and food processing can eliminate its healthful benefits.

Reporting in the August issue of the Journal of Dairy Science, a group of scientists has formulated low-lactose functional milk that maintained beneficial levels of American ginseng after processing. An exploratory study found the product was readily accepted by a niche group of consumers.

“Our goal was to develop low-lactose milk that could be consumed by the elderly to improve cognitive function,” reports lead investigator S. Fiszman, “Consumers who were interested in the health benefits of ginseng rated our product quite highly.”

Because older people frequently have trouble digesting milk products, the researchers developed a low-lactose formula. American ginseng was added, and then the milk was sterilised by ultra-high temperature processing (UHT), which prolongs shelf life. Analysis found that sufficient levels of ginseng remained in the milk after treatment to improve cognitive function as reported in the literature. To reduce the bitter taste of ginseng, the investigators developed samples with vanilla extract and sucralose, a zero-calorie artificial sweetener. In a preliminary study, 10 tasters with a good ability to discriminate between flavors compared low lactose UHT milk without any additives (the control) to low lactose milk with ginseng extract, vanilla aroma, and sucralose added before UHT treatment.

They developed a list of 10 attributes that described the sample: colour, sweet odour, milk flavor, vanilla flavour, metallic/root flavour, sweetness, bitterness, aftertaste, astringency, and viscosity. They then rated the intensity of each attribute for five samples; the control; the control with ginseng extract, vanilla aroma, and sucralose added; the control with ginseng extract added; the control with vanilla and ginseng extract; and the low lactose milk with ginseng extract; vanilla aroma; and sucralose added before UHT treatment. In a second study, 100 participants were asked, on a scale of one to five, how willing they would be to consume a “highly digestible semi-skimmed milk,” and a “highly digestible semi-skimmed milk enriched with ginseng extract that would improve cognitive function.”

Then, they tasted and rated, on a scale of one to nine, the overall acceptability of the control milk and the low lactose milk with ginseng extract, vanilla aroma, and sucralose added before UHT treatment. Both the presence of ginseng and the thermal treatment affected some sensory properties of the milk. The addition of ginseng significantly increased the perceived light brown colour in the flavoured and unflavoured samples, and was highest in the reduced-lactose milk with ingredients added before the UHT treatment.

The sweet odour was more intense in flavoured samples, but decreased slightly in the samples of milk with ingredients added before UHT treatment. Bitterness was clearly perceived in the samples containing ginseng additives, but was lower in flavoured samples, indicating that the vanilla aroma and sucralose masked, to some extent, the bitter taste caused by ginseng extract.

Consumer responses varied greatly, depending on interest in the product. 78 p.c. indicated that they would be likely to consume the highly digestible milk, and after tasting the product, 87 p.c. of them indicated they would buy the sample. 47 p.c. indicated they were not interested in milk enriched with ginseng, and after tasting, they gave it a low acceptability rating.

However, for the 32 p.c. of consumers who did express an interest in the product, 75 p.c. declared they would buy it. “Drinking 150 to 300 mL of this ginseng-enriched milk would provide the amount indicated to be effective for improving cognitive functions. Combined with the low levels of lactose, this makes the drink an appropriate functional beverage for the elderly,” says Dr. Fiszman. “Among consumers more likely to consume ginseng products, the newly developed milk was well accepted. The addition of more congruent flavours such as chocolate, citrus, or coffee, could be more effective in masking non-milk-related sensory attributes, Other alternatives could be investigated.”

Commenting on the studies, Susan Duncan, professor, Department of Food Science Technology, Virginia Tech, noted, “With the combination of intrinsic health benefits in milk and these additional ingredients, milk becomes an easy way to deliver valuable functional ingredients and the functional benefits of milk components. Diversifying the product line for milk and dairy products has a number of benefits, including market and consumer visibility and perception.

- esciencenews

How the brain focuses on what's most useful

Ever wondered how the human brain, which is constantly bombarded with millions of pieces of visual information, can filter out what's unimportant and focus on what's most useful?

The process is known as selective attention and scientists have long debated how it works. But now, researchers at Wake Forest Baptist Medical Centre have discovered an important clue. Evidence from an animal study, shows that the prefrontal cortex is involved in a previously unknown way.

Two types of attention are utilised in the selective attention process - bottom up and top down. Bottom-up attention is automatically guided to images that stand out from a background by virtue of colour, shape or motion, such as a billboard on a highway. Top-down attention occurs when one's focus is consciously shifted to look for a known target in a visual scene, as when searching for a relative in a crowd.

Traditionally, scientists have believed that separate areas of the brain controlled these two processes, with bottom-up attention occurring in the posterior parietal cortex and top-down attention occurring in the prefrontal cortex.

“Our findings provide insights on the neural mechanisms behind the guidance of attention,” said Christos Constantinidis, associate professor of neurobiology and anatomy at Wake Forest Baptist and senior author of the study. “This has implications for conditions such as attention deficit hyperactivity disorder (ADHD), which affects millions of people worldwide. People with ADHD have difficulty filtering information and focusing attention. Our findings suggest that both the ability to focus attention intentionally and shifting attention to eye-catching but sometimes unimportant stimuli depend on the prefrontal cortex.”

In the Wake Forest Baptist study, two monkeys were trained to detect images on a computer screen while activity in both areas of the brain was recorded. The visual display was designed to let one image “pop out” due to its colour difference from the background, such as a red circle surrounded by green. To trigger bottom-up attention, neither the identity nor the location of the pop-out image could be predicted before it appeared.

The monkeys indicated that they detected the pop-out image by pushing a lever.

The neural activity associated with identifying the pop-out images occurred in the prefrontal cortex at the same time as in the posterior parietal cortex.

This unexpected finding indicates early involvement of the prefrontal cortex in bottom-up attention, in addition to its known role in top-down attention, and provides new insights into the neural mechanisms of attention.“We hope that our findings will guide future work targeting attention deficits,” Constantinidis said.

- MNT

Fear and anxiety alter choices

Anxiety disorders affect approximately 40 million US adults each year, and although they are treatable, they often cause significant distress.

The excessive fear and dread that accompanies anxiety disorders clearly influences the everyday decision-making processes of anxious individuals. Despite its importance, “there is surprisingly little research on how anxiety disorders influence decisions,” said neuroscientist Dr. Elizabeth Phelps, who co-authored this new review with Dr. Catherine Hartley, both of New York University.

Their review highlights that science is “starting to gain some traction by combining emerging decision science with the study of anxiety.

The overlap in the neural systems underlying anxiety and decision-making provides some insight into how fear and anxiety alters choices,” explained Dr. Phelps. Dr. Hartley added, “Historically, research has focused on the influence of anxiety on how we attend to and interpret events. These same processes should shape how anxious individuals make decisions.”Their review explores the role of anxiety in decision-making using a neuroeconomic approach. Neuroeconomics is an interdisciplinary field that combines tools from the fields of economics, neuroscience, and psychology to study the brain's decision-making processes.

The authors discuss the overlap between the neural systems mediating fear and anxiety and those implicated in studies of economic decision-making.Neuroeconomics research has revealed that circuits involving the amygdala, insular cortex, and prefrontal cortex are involved in tasks with uncertainty or loss.

The amygdala is a key brain region that helps regulate fear and anxiety, while the prefrontal cortex is critically involved in the control of fear.The authors also review a set of decision-making biases exhibited by anxious individuals and propose that the neural circuitry supporting fear learning and regulation may mediate anxiety's influence upon their choices.

“Hartley and Phelps provide an elegant example of how reward-related decision making may be affected by other neural circuitries, in this case the emotional processing system,” commented neuroeconomics experts Drs. Carla Sharp and P. Read Montague. “This is without a doubt part of the future of the application of neuroeconomics to psychiatric disorder, as no example of psychiatric disorder can be reduced simply to reward-related decision making.

- MNT