sexta-feira, 28 de novembro de 2014

'Trigger' for stress processes discovered in brain

 


At the Center for Brain Research at the MedUni Vienna an important factor for stress has been identified in collaboration with the Karolinska Institutet in Stockholm (Sweden). This is the protein secretagogin that plays an important role in the release of the stress hormone CRH and which only then enables stress processes in the brain to be transmitted to the pituitary gland and then onwards to the organs. A current study on this molecular switch has now been published in the EMBO Journal.

"If, however, the presence of secretagogin, a calcium-binding protein, is suppressed, then CRH (= Corticotropin Releasing Hormone) might not be released in the hypothalamus of the brain thus preventing the triggering of hormonal responses to stress in the body," explains Tibor Harkany of the Department of Molecular Neurosciences at the MedUni Vienna.

The hypothalamus requires the assistance of CRH to stimulate the production and release of the hormone ACTH from cells in the pituitary gland into the blood stream. Thus, ACTH reaches the adrenal cortex and once there stimulates the production and release of further hormones including, cortisol, a vital stress hormone. Upon stress, the hypothalamus responds by releasing CRH and thus produces the critical signal orchestrating also ACTH and cortisol secretion. However, if this cycle is interrupted, it is not possible for acute, and even chronic, stress to arise.

Another interesting fact: secretagogin was discovered at the MedUni Vienna 15 years ago by Ludwig Wagner at the University Department of Internal Medicine III in connection with research on the pancreas.

Therapeutic approach for stress

"Now we have a better understanding of how stress is generated," says Tomas Hökfelt of the Karolinska Institutet and guest professor at the MedUni Vienna. This could result in a further development where secretagogin is deployed as a tool to treat stress, perhaps in people suffering from mental illness such as depression, burn out or posttraumatic stress disorder, but also in cases of chronic stress brought on by pain. If a rapid recovery phase follows a period of stress, body and mind are restored to "normal working," which is associated with a suppression of the release of circulating stress hormones.

In contrast, the consequences of chronic stress are manifold and can, for example, lead to an increased tendency to suffer from infections but also to high blood pressure, diabetes and an increased risk of cardio-vascular disease right through to chronic headaches, tinnitus or osteoporosis.

Illnesses resulting from stress steadily increase in frequency and place a burden on the health care system. The European Agency for Safety and Health at Work has therefore dedicated 2014 to the subject of stress. According to the Austrian employees' organisation, international studies show that in Europe over 50 percent of sick leave is attributable to a form of stress. In a recent analysis by the Austrian Economic Research Institute, IWS, a figure of seven billion Euros a year was placed on the economic damage due to mental illness in Austria


Story Source:

The above story is based on materials provided by Medical University of Vienna. Note: Materials may be edited for content and length.


Journal Reference:

  1. R. Romanov, A. Alpar, M.D. Zhang, A. Zeisel, A. Calas, M. Landry, M. Fuszard, S. Shirran, R.Schnell, A. Dobolyi, M. Olah, L. Spence, J. Mulder, H. Martens, M. Palkovits, M. Uhlen, H. Sitte, C. Botting, L. Wagner, S. Linnarsson, T. Hökfelt, T. Harkany. A secretagogin locus of the mammalian hypothalamus controls stress hormone release. EMBO Journal, October 2014 DOI: 10.15252/ embj.201488977

 

New research supporting stroke rehabilitation

 

November 27, 2014

Frontiers

New research could help improve stroke patients' rehabilitation, experts say. The research may provide useful applications for the care of stroke patients who have restricted use of their upper limbs. If stroke patients practice the techniques recommended by the study, it could potentially help maintain activity in movement-related brain areas, especially when used alongside more traditional physiotherapy techniques where the same movements are also practiced physically.


Using world-leading research methods, the team of Dr David Wright and Prof Paul Holmes, working with Dr Jacqueline Williams from the Victoria University in Melbourne, studied activity in an area of the brain responsible for controlling movements when healthy participants observed a video showing simple hand movements and simultaneously imagined that they were performing the observed movement.

Using transcranial magnetic stimulation -- a technique where a coil placed over the scalp delivers a stimulation to the brain, activates neurons in the underlying area, and causes a muscular contraction in the participant's hand -- the researchers found that combining imagery (imagining the feelings associated with performing the movement) with observation (watching the movement) created the strongest activity in the brain.

Using electrodes on the participant's hand, the researchers found that muscle contractions in response to the cortical stimulation were larger when participants were concurrently imagining themselves moving their muscle whilst watching a video of a hand moving on screen, compared to when they used the imagery or observation techniques alone. or engaged in various control conditions.

This research, which is published in the open-access journal Frontiers in Human Neuroscience, may provide useful applications for the care of stroke patients who have restricted use of their upper limbs. If stroke patients practice the recommended techniques, it could potentially help maintain activity in movement-related brain areas, especially when used alongside more traditional physiotherapy techniques where the same movements are also practiced physically.

Dr Wright said: "The idea is that because imagery and observation techniques share some characteristics with physical movement in terms of activating similar areas of the brain, if someone can't perform the movements themselves physically, it might be possible to keep those areas of the brain active through imagery and observation techniques. This might help contribute to the recovery of motor function."

Currently, imagery and, less frequently, observation are used separately alongside physical therapy during the rehabilitation of stroke patients, but Prof Holmes suggested that combining the two techniques may support re-learning of movement patterns for some patients.

He said: "After a stroke, parts of the brain die and will not recover. To compensate, other parts of brain can alter their function to take control of the lost behaviour -- a form of brain plasticity. We think that combining imagery and observation, in addition to physical therapy, may allow the brain to speed up this plastic change as well as benefitting more psychological aspects of recovery such as movement confidence." He continued, "the research team's work in this area has the potential to make a real impact on the way physiotherapists, occupational therapists and nurses work with the stroke community"

"These changes may happen without the intervention -- it is certainly not a miracle cure -- but the combined imagery and action observation approach should speed up the process of relearning movements that have been lost."

The research was funded by Manchester Metropolitan University's Knowledge Exchange Innovation Fund and a Research Accelerator Grant awarded to Dr Wright (an early career researcher in the Motor Cognition Research section of the Centre of Health, Exercise and Active Living).

Future research by the Group will seek to establish optimal methods for delivering these psychological interventions for stroke rehabilitation by investigating the effects of different types of instruction given to participants and different video presentation methods on activity in the brain during combined imagery and observation. The team also expect to release a stroke rehabilitation App in early 2015.


Story Source:

The above story is based on materials provided by Frontiers. Note: Materials may be edited for content and length.


Journal Reference:

  1. David J. Wright, Jacqueline Williams, Paul S. Holmes. Combined action observation and imagery facilitates corticospinal excitability. Frontiers in Human Neuroscience, 2014; 8 DOI: 10.3389/fnhum.2014.00951

 

Mindfulness treatment as effective as CBT for depression, anxiety

 


Group mindfulness treatment is as effective as individual cognitive behavioral therapy (CBT) in patients with depression and anxiety, according to a new study from Lund University in Sweden and Region Skåne. This is the first randomized study to compare group mindfulness treatment and individual cognitive behavioral therapy in patients with depression and anxiety in primary health care.

The researchers, led by Professor Jan Sundquist, ran the study at 16 primary health care centres in Skåne, a county in southern Sweden. They trained two mindfulness instructors, from different occupational groups, at each primary health care centre during a 6-day training course.

In spring 2012, patients with depression, anxiety or reactions to severe stress were randomized to either structured group mindfulness treatment with approximately 10 patients per group, or regular treatment (mainly individual CBT). Patients also received a private training programme and were asked to record their exercises in a diary. The treatment lasted 8 weeks. General practitioner and mindfulness instructor Ola Schenström designed the mindfulness training programme and model for training instructors.

A total of 215 patients were included in the study. Before and after treatment, the patients in the mindfulness and regular treatment groups answered questionnaires that estimated the severity of their depression and anxiety. Self-reported symptoms of depression and anxiety decreased in both groups during the 8-week treatment period. There was no statistical difference between the two treatments.

"The study's results indicate that group mindfulness treatment, conducted by certified instructors in primary health care, is as effective a treatment method as individual CBT for treating depression and anxiety," says Jan Sundquist. "This means that group mindfulness treatment should be considered as an alternative to individual psychotherapy, especially at primary health care centres that can't offer everyone individual therapy."


Story Source:

The above story is based on materials provided by Lund University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jan Sundquist, Åsa Lilja, Karolina Palmér, Ashfaque A. Memon, Xiao Wang, Leena Maria Johansson And Kristina Sundquist. Mindfulness group therapy in primary care patients with depression, anxiety and stress and adjustment disorders: randomised controlled trial. The British Journal of Psychiatry, November 2014 DOI: 10.1192/bjp.bp.114.150243

 

Soon we could make all sorts of things from sawdust

 

Sawdust can be converted into a fuel additive – among other things – using a new chemical ...

Sawdust can be converted into a fuel additive – among other things – using a new chemical process (Photo: Rasbak)

 

This is science at its best: When I was growing up, the only practical use for sawdust was to soak up vomit, but thanks to scientists at a Belgian university who developed a new chemical process, that same sawdust could soon be used in gasoline and other products normally derived from petroleum.

Researchers at KU Leuven university’s Centre for Surface Chemistry and Catalysis have been able to take the cellulose in sawdust and convert it into hydrocarbon chains. These can be used as an additive in gasoline or as building blocks to create plastics, rubber, nylon, insulation foams and other materials normally made from ethylene, propylene and benzene.

"This is a new type of bio-refining, and we currently have a patent pending for it," says Dr. Bert Lagrain, co-author of a paper on the team's findings. "We have also built a chemical reactor in our lab: we feed sawdust collected from a sawmill into the reactor and add a catalyst – a substance that sets off and speeds the chemical reaction. With the right temperature and pressure, it takes about half a day to convert the cellulose in the wood shavings into saturated hydrocarbon chains, or alkanes."

The resulting product does not come out as fully-distilled gasoline – this requires one final step – but the researchers say their biomass-based product can be used as a green additive that replaces a "portion of traditionally-refined gasoline."

The researchers are also excited about the potential of cellulose to replace other products currently derived from petroleum, and its general abundance and accessibility. "Cellulose is available everywhere; it is essentially plant waste, meaning it does not compete with food crops in the way that first generation energy crops – crops grown for bioethanol, for example – do," says KU Leuven's Prof. Bert Sels.

The team's paper was recently published in the journal Energy & Environmental Science.

Source: KU Leuven

 

Can China Cut Coal?

 

By David Biello | November 25, 2014

The views expressed are those of the author and are not necessarily those of Scientific American.

 


On a visit to China a few years back, I asked a local official about pollution controls after enjoying my first sour, gritty taste of the country’s air. China’s new coal-fired power plants and other industrial boilers often came equipped with expensive scrubbers to clean acid rain and smog-forming sulfur dioxide out of the hot mix of gases that went up and out the smokestack. But the scrubbers required energy to run, this official noted, and therefore were shut off except on days when dignitaries (or foreign journalists) visited.

china-coal-power

An old coal-fired power plant on the banks of the Yangtze River. © David Biello

According to Hu Tao, an ecologist and environmental economist who directs the China program at the World Wildlife Fund, not much has changed. On his recent visit to a coal-fired power plant, the scrubber was turned off for “inspection,” he explained at a talk at the Woodrow Wilson Center’s China Environment Forum on November 24. How often were such machines inspected, Tao inquired? Well, if no one from the government was visiting, the plant manager told him, the machine is turned off every day.

china-coal-fired-power-plant-control-room

The control room of a typical modern coal-fired power plant in China. © David Biello

That is the current context for China’s recent decree that the country will never consume more than 4.2 billion metric tons of coal per year, the action following a historic agreement with the U.S. to begin to combat climate change. Already, caps on the amount of coal a given locality can burn seem to have dropped coal’s share of total energy in China for the first time in the 21st century, though overall it has tripled since 2000. “The vast majority of China’s CO2 emissions are a result of coal combustion,” said Jake Schmidt, director of the Natural Resources Defense Council’s international program at the CEF event.

If the central government’s cap is achieved, then China’s carbon dioxide emissions would never top 12 billion metric tons per year or so—up from roughly 10 billion metric tons per year as of now. Already, China’s coal burning alone accounts for 20 percent of the entire world’s CO2 pollution.

china-coal-consumption-eia

Courtesy of U.S. Energy Information Administration

For comparison, the U.S. emits slightly more than 5 billion metric tons of CO2 per year these days. And if the recent pledges hold firm, the American and Chinese lifestyles would converge at a pollution level of roughly 10 metric tons per person by 2030.

This is a tall order. To achieve such a halt in coal consumption, China will have to build as much wind, solar, nuclear and hydropower in the next 10 years as it has built coal-fired power plants in the last 10 years—as much as 1000 gigawatts worth of alternatives to coal, also including natural gas, whether pipelined from Russia or fracked out of the country’s own shale deposits. And even if that dream is realized, an International Energy Agency analysis suggests such a build out, though possible, is not sufficient to slow rising coal consumption unless China’s economic or electricity use growth also slow significantly. To truly get China’s CO2 pollution problem under control will require yet more technology, such as CO2 capture and storage, to clean up the emissions from existing coal-fired power plants.

The question is: once that technology is installed, will it be turned on?

wind-turbine-innards

Several pivots to which wind turbine blades attach, awaiting assembly at a factory in China. © David Biello

Coal is cheap and getting cheaper in China. In fact, though the country may require more and more coal imports to satisfy its voracious demand, the cost of coal is cheaper now than in 2000, according to an analysis by WWF’s Hu. As a result, the owners of coal-fired power plants can still make money burning the polluting rock to generate electricity—and even more money if they keep pollution controls in the off position. Local governments have few reasons to complain (unless the provincial or central government steps in) given the resulting economic growth, increasing number of jobs and tax revenue. As a result, China’s carbon intensity—the amount of CO2 produced per unit of economic output—has stopped declining in recent years, thanks mostly perhaps to the unprecedented boom in burning coal to make cement and steel to build China’s burgeoning cities and infrastructure. “For the companies, one side is low coal price and the other side is coal cap regulations. Which one should they follow?” Tao asked, noting that a carbon tax could solve this conundrum decisively. “One says use more and one says use less.”

chongqing-smog

A smoggy view of Chongqing, an inland mega-city and one of the "furnaces" of China. © David Biello

The real crisis in China is not invisible CO2 but the more visible kind of air pollution, which, in addition to killing people prematurely, is obscuring entire cities. The joke the last time I visited China was that the smog shielded the country from U.S. spy satellites but the truth is that cities like Beijing, Jinan, and Shenyang suffer from soot and smog in the air at levels at an air quality index level above 200 on some days. The central government considers anything below 100 to be a “blue sky day” though the World Health Organization recommends the AQI should never go above 20 (the U.S. and Europe also fail to meet that standard). “If you live in Beijing, it doesn’t matter if you are poor or rich, you cannot avoid air pollution,” Schmidt noted.

As a result, air pollution has become a central focus of the central government—and the country’s prime minister Li Keqiang went so far as to declare a war on it. “Air pollution has become one of the most important issues facing China today, both for social stability and also international reputation,” said Barbara Finamore, NRDC’s Asia director and Beijing resident, in a conference call with reporters on November 6. “Efforts to drive air pollution down are having very beneficial impacts on coal use.”

WWF’s Hu suggests the best way to reduce coal use even further is to make sure the price goes up by imposing the equivalent of a carbon tax—and the central government is considering a countrywide price on CO2 as part of a national cap and trade market in greenhouse gas pollution in coming years. Such a program might also give the central government a better chance of seeing what’s actually happening with coal use and pollution control at the local level. “If we don’t reduce coal consumption, we have no way to reduce PM 2.5,” or particular matter of 2.5 microns smaller, more commonly known as soot, added Yang Fuqiang, NRDC’s senior advisor on energy, environment and climate change in Beijing, at the CEF event.

beijing-smokestack

A smokestack pokes up above the buildings in Beijing on a blue-sky day. © David Biello

But battling soot does not necessarily mean curbing CO2 pollution as well. One solution for air quality in a city like Beijing is to move factories and other coal-fired industry out of the city or to turn coal to gas or liquids before burning it, which reduces the soot choking lungs but results in even more CO2 pollution than just burning the coal directly. “There is a real potential for shifting coal use in China from most polluted regions inland, which is why a national cap on coal consumption that’s mandatory is so important,” Finamore said.

At the same time, regions in the west of China may now rush to build coal-fired power plants and industry before any national efforts take effect. “We give a warning to the western regions, you have to set up coal right now,” Yang said. “In the future, it is too late.”

In short, how China actually grows its energy system in the next decade or so will determine whether or not the world has any real hope to combat climate change. If the Chinese dream does include a good environment, as China’s President Xi Jinping has said in the past, then a transformation even more remarkable than the one the country has undergone in the last 25 years will be required. And that means turning the pollution controls on for good.

Snap 2014-11-19 at 02.15.11