Author: Théophile Niyitegeka

{Study finds that anger, guilt can inspire positive health habits}

Feeling down is a common side effect of being diagnosed with cancer. Anxiety, guilt, and distress often come hand-in-hand with diagnosis and treatment.

But a recent study by researchers from Concordia and the University of Toronto shows that these seemingly negative emotions can actually be good for patients.

Andrée Castonguay, the study’s lead author and a postdoctoral researcher in Concordia’s Faculty of Arts and Science, says feelings of anger or guilt can inspire people to set new goals and engage in more moderate-to-vigorous exercise.

“That helps counteract the boost in the stress hormone cortisol, which those emotions also cause, and which can negatively disrupt the way the body functions,” she adds.

The research, published in the journal Health Psychology, looked at recently diagnosed and treated breast cancer patients.

For the study, Castonguay and her co-authors, Concordia psychology professor Carsten Wrosch and University of Toronto kinesiology professor Catherine Sabiston, had 145 breast cancer survivors fill out a questionnaire to assess their emotions, capacity to engage in new goals and level of physical activity.

The researchers also analyzed cortisol levels using saliva samples provided five times over the course of a year by the participants.

The team then conducted detailed analyses using a modelling technique that helped them predict the relationship between the women’s negative feelings, commitment to new goals, physical activity and cortisol levels over time.

They found that participants’ capacity for setting new goals, like starting to go for brisk walks, facilitated the beneficial effect of negative emotions on physical activity and prevented the adverse effects of increased cortisol, which can result in a host of health problems, including a weakened immune system.

“Our results underscore the complexity of the link between emotions and health,” explains Wrosch, who is also a member of the Centre for Research in Human Development.

“Although negative emotions have a bad reputation and have been linked to disease, they are also ‘designed’ to produce adaptive behaviours.”

In particular, he adds, emotions like guilt or anxiety may motivate people to change their health-compromising behaviours and engage in more exercise. “This may be particularly important among certain cancer survivors, since inactivity, weight problems or obesity can be common risk factors.”

Castonguay says that, although recent guidelines encourage breast cancer survivors to engage in healthy lifestyle behaviours, few survivors actually engage in the recommended levels.

“This includes 150 minutes of moderate-to-vigorous physical activity per week to reduce the risk of developing further health problems related to immune function, weight management and quality of life.”

Based on their findings, the researchers conclude that certain negative emotions can play an important role in directing adaptive health behaviours among some cancer survivors and can contribute to long-term benefits on their physical health.

“The capacity to commit to and engage in new goals is an important resource for helping survivors meet activity recommendations and minimize the negative impact of bad moods on their biological functioning,” Castonguay says.

She hopes that the study will encourage clinicians to identify cancer survivors who have difficulty selecting and commiting to new goals, and to work with them to help them follow through.

Source:Science Daily

{Living in a stimulating environment has a wide range of health benefits in humans and has even been shown to fight cancer in mice, but the underlying mechanisms have been unclear. A study published April 25 in Cell Reports reveals that cognitive stimulation, social interactions, and physical activity increase lifespan in mice with colon cancer by triggering the body’s wound repair response.}

“The bottom line is that there are many benefits with minimal risks to reducing stress through mind-body interventions,” says senior author Melinda Angus-Hill of the Huntsman Cancer Institute at the University of Utah. “However, more research is essential to define whether mind-body interventions drive a wound repair response in colon tumorigenesis in humans.”

Mind-body medicine focuses on reducing the physiological manifestations of stress and anxiety by improving social and cognitive stimulation, as well as physical activity. A growing body of evidence suggests that mind-body medicine can significantly improve overall health. For example, epidemiological studies have found that depression, stress, and social isolation increase the risk of cancer progression. However, the molecular and cellular mechanisms underlying these effects have not been clear.

To address this question, Angus-Hill and her team exposed mice with colon cancer to environmental enrichment by housing them in cages filled with many other mice, along with running wheels, tunnels, huts, igloos, and nesting materials. The researchers found that exposure to stimulating surroundings increased the lifespan of male and female mice with colon tumors (55 days and 82 days, respectively) but most likely through different mechanisms. Environmental enrichment reduced tumor size in females but decreased blood levels of inflammatory molecules in males.

A reduction in inflammation is a key step in the wound repair process, and it has long been recognized that tumors resemble wounds that do not heal. So the researchers suspected that environmental enrichment might also trigger other steps of the wound repair process, thereby improving the survival of male mice with colon cancer. Consistent with this idea, they found that environmental enrichment activated nuclear hormone receptor signaling pathways involved in wound repair and improved tumor vasculature in male mice with colon cancer.

Blood vessels in the tumor microenvironment are often nonfunctional, preventing cancer drugs from reaching their target. Therefore, these findings suggest that environmental enrichment could improve the delivery of chemotherapeutic or immunotherapeutic agents to the colon tumor. “Our findings support additional studies into the future application of mind-body intervention in combination with conventional therapy for patients with colorectal cancer,” Angus-Hill said.

Moreover, environmental enrichment stimulated immune cells called plasma cells to produce an antibody called Immunoglobulin A (IgA), which attached to the surface of pericytes located on the outside of blood vessels. The activated, IgA-bound pericytes then migrated to and replaced glandular structures at the periphery of tumors, thereby sealing the wound in a process similar to scarring. Ultimately, the wound repair process restored the integrity of the colon barrier, defended against pathogens, and improved the composition of gut microbes, thereby reducing inflammation.

“Our study demonstrates a positive role of environmental enrichment-induced IgA secreting plasma cells and raises the possibility of harnessing their potential for therapeutic purposes in colon cancer, particularly in people who practice stress reduction techniques and who are physically active,” Angus-Hill says.

Based on these findings, Angus-Hill and her team are now planning on initiating clinical trials to study the effects of mind-body therapy in patients with colon cancer. They would also like to examine how environmental enrichment improves the survival of female mice with colon cancer and what explains the different effects between the sexes. Another important goal will be to pinpoint the molecular mechanisms that are essential for the beneficial effects of wound repair following environmental enrichment. “This could aid in developing pharmacological strategies that mimic mind-body medicine,” Angus-Hill says. “The availability of a pharmacological treatment to effortlessly reduce stress would be invaluable for cancer and disease prevention and treatment.”

Source:Science Daily

{In animal studies, researchers design fluid-filled environment to bridge critical time from mother’s womb to outside world}

A unique womb-like environment designed by pediatric researchers could transform care for extremely premature babies, by mimicking the prenatal fluid-filled environment to give the tiniest newborns a precious few weeks to develop their lungs and other organs.

“Our system could prevent the severe morbidity suffered by extremely premature infants by potentially offering a medical technology that does not currently exist,” said study leader Alan W. Flake, MD, a fetal surgeon and director of the Center for Fetal Research in the Center for Fetal Diagnosis and Treatment at Children’s Hospital of Philadelphia (CHOP).

Flake and colleagues report on preclinical studies of their extra-uterine support device in Nature Communications. They tested and monitored effects on fetal lambs, in which prenatal lung development is very similar to that occurring in humans.

The innovative system uses a unique fluid-filled container attached to custom-designed machines that provide physiologic support. The fetal lambs grow in a temperature-controlled, near-sterile environment, breathing amniotic fluid as they normally do in the womb, their hearts pumping blood through their umbilical cord into a gas exchange machine outside the bag. Electronic monitors measure vital signs, blood flow and other crucial functions.

Of the one in ten U.S. births that are premature (younger than 37 weeks gestational age), about 30,000 per year are critically preterm — younger than 26 weeks. Extreme prematurity is the nation’s leading cause of infant mortality and morbidity, accounting for one-third of all infant deaths and one-half of all cases of cerebral palsy attributed to prematurity.

Neonatal care practices have improved overall survival of premature infants and have pushed the limits of viability to 22 to 23 weeks of gestation. At that age an infant weighs below 600 grams — little more than a pound — and has a 30 to 50 percent chance of survival. But this survival comes at a high price in quality of life, with a 90 percent risk of morbidity, from chronic lung disease or other complications of organ immaturity. Survivors face lifelong disability.

“These infants have an urgent need for a bridge between the mother’s womb and the outside world,” said Flake. “If we can develop an extra-uterine system to support growth and organ maturation for only a few weeks, we can dramatically improve outcomes for extremely premature babies.” The goal is to support infants from 23 weeks to 28 weeks gestational age; at 28 weeks they cross the threshold away from the most severe outcomes.

In the current study, the researchers describe the evolution of their system over three years, through a series of four prototypes, beginning with a glass incubator tank, and progressing to the current device. The eight preterm lambs tested in the most recent prototype were physiologically equivalent to a 23- or 24-week-gestation human infant.

The current system mimics life in the uterus as closely as possible, building on knowledge from previous neonatal research. There is no external pump to drive circulation, because even gentle artificial pressure can fatally overload an underdeveloped heart, and there is no ventilator, because the immature lungs are not yet ready to do their work of breathing in atmospheric oxygen. Instead, the baby’s heart pumps blood via the umbilical cord into the system’s low-resistance external oxygenator that substitutes for the mother’s placenta in exchanging oxygen and carbon dioxide.

In addition, amniotic fluid, produced in the laboratory, flows into and out of the bag. “Fetal lungs are designed to function in fluid, and we simulate that environment here, allowing the lungs and other organs to develop, while supplying nutrients and growth factors,” said fetal physiologist Marcus G. Davey, PhD, who designed and redesigned the system’s inflow and outflow apparatus.

The sealed, sterile environment inside the system is insulated from variations in temperature, pressure and light, and particularly from hazardous infections.

Previous researchers have investigated versions of an artificial placenta in animal models, but pumpless systems have achieved a maximum duration of 60 hours, and the animals have sustained brain damage. The new system, in contrast, has operated up to 670 hours (28 days) with some animals, which remained healthy. The lambs showed normal breathing and swallowing, opened their eyes, grew wool, became more active, and had normal growth, neurological function and organ maturation.

The program team brings together a broad range of experts at CHOP, including neonatologists, fetal medicine specialists, respiratory therapists, perfusionists and others. The initial impetus for the program came from CHOP research fellow Emily Partridge, MD, PhD, who experienced the challenges of caring for critically premature infants. “Those infants really struck a chord with me,” she said. She researched existing scientific literature, and five years ago proposed to Flake the pilot project that became the current device.

The researchers will continue to evaluate and refine the system, and will need to downsize it for human infants, who are one-third the size of the infant lambs used in the current study.

If their animal results translate into clinical care, Flake envisions that a decade from now, extremely premature infants would continue to develop in chambers filled with amniotic fluid, rather than lying in incubators, attached to ventilators. Added to the desired health benefits, there could be a large economic impact as well, reducing the estimated $43 billion annual medical costs of prematurity in the U.S.

Flake stresses that the team does not aim to extend viability to an earlier period than the current mark of 23 weeks. Before that point, limitations of physical size and physiologic functioning would impose unacceptably high risks. However, he added, “This system is potentially far superior to what hospitals can currently do for a 23-week-old baby born at the cusp of viability. This could establish a new standard of care for this subset of extremely premature infants.”

Source:Science Daily