(Press-News.org) A study published today in the journal Science shows how our bodies try to minimise potential 'collateral damage' caused by our immune system when fighting infection. The research may also provide new clues to why cigarette smoke is a significant risk factor for developing diseases of the lung such as chronic bronchitis and emphysema.
When bacteria or viruses enter the body, our immune system fights back to neutralise any danger. One of the key 'soldiers' working for the immune system is a particular type of cell known as a neutrophil, which releases toxic enzymes to kill the invading organism. But these enzymes can cause collateral damage to surrounding tissue, and so the neutrophils need to act swiftly and leave the site of infection as quickly as possible.
"Neutrophils are powerful at fighting infection, but if left unchecked, they can cause damage to our own bodies," explains Dr Robert Snelgrove, a Sir Henry Wellcome Postdoctoral Fellow at Imperial College London, who carried out the study together with colleagues from the University of Alabama at Birmingham, USA. "We know that their persistence contributes to the development and severity of many chronic lung diseases such as chronic obstructive pulmonary disease and cystic fibrosis."
The enzymes released by neutrophils can cause particular damage in the lung, where they can attack the collagen which makes up the lung's architecture, selectively cutting out a molecular fragment known as PGP. This fragment in turn recruits more neutrophils, potentially leading to a vicious circle of damage.
However, in research published today and part-funded by the Wellcome Trust, Dr Snelgrove and colleagues show how another enzyme released by the lungs – LTA4H – degrades PGP, breaking the cycle and preventing damage.
In a second experiment, the researchers also showed that chemicals found in cigarette smoke can have a negative effect on this process, modifying PGP in a way that increases its ability to recruit more neutrophils and protecting it from degradation, and inhibiting the performance of LTA4H.
Patients with diseases such as chronic bronchitis and emphysema, which are collectively known as chronic obstructive pulmonary disease (COPD), tend to have persistent neutrophils in the lungs
"We have known for some time now that there is a link between smoking and COPD," says Dr Snelgrove. "Here we have shown that cigarette smoke can severely limit the effectiveness of an enzyme which contributes to the clearance of these rogue immune cells. This may be a contributing factor to damage to the lungs which affects a person's ability to breathe easily."
There are an estimated three million people in the UK living with diseases such as chronic bronchitis and emphysema, which are collectively known as chronic obstructive pulmonary disease (COPD). This condition is caused by damage to the lungs, most commonly as a result of smoking, and leads to an inability to breathe properly.
The researchers believe that the research may have implications for the development of new drugs aimed at treating acute and inflammatory diseases. As well as working to reduce inflammation, LTA4H more commonly works to promote inflammation. However, drugs aimed at inhibiting the pro-inflammatory activity of LTA4H could have repercussions for preventing degradation of PGP, causing potential lung damage, they caution.
INFORMATION: END
New models, reinforced by in vivo experimentation, show why 5-10% of bone fractures don't heal properly, and how these cases may be treated to restart the healing process. Results of the model, published September 2 in the open-access journal PLoS Computational Biology, may benefit the ageing population in which the occurrence of bone fractures is expected to rise substantially in the near future.
In 5 to 10% of bone fracture cases, the healing process does not succeed in repairing the bone, which leads to the formation of delayed unions or even non-unions - fractures ...
GAINESVILLE, Fla. --- Ants are not out of their weight class when defending trees from the appetite of nature's heavyweight, the African elephant, a new University of Florida study finds.
Columns of angered ants will crawl up into elephant trunks to repel the ravenous beasts from devouring tree cover throughout drought-plagued East African savannas, playing a potentially important role in regulating carbon sequestration in these ecosystems, said Todd Palmer, a UF biology professor and co-author of a paper being published this week in the journal Current Biology.
"It ...
DURHAM, N.C. – Millions of patients with advanced disease in palliative care settings receive oxygen therapy to help them breathe more easily. But a new study from Duke University Medical Center says roughly half of them don't benefit from the intervention, and among those who do benefit, it doesn't make a bit of difference whether they get pure oxygen or just plain old room air – both offer equal benefit.
"Offering oxygen when patients begin experiencing shortness of breath has become standard care in many places, but the practice is not based on rigorous scientific ...
Lupus Research Institute-funded researcher Betty Tsao, PhD, at the University of California Los Angeles has discovered that humans—males in particular—with a variant form of the immune receptor gene "Toll Like Receptor 7 (TLR7)" are at increased risk of developing the autoimmune disease systemic lupus erythematosus (lupus). This breakthrough finding offers renewed hope for developing more targeted treatments.
The powerful finding recently published in the Proceedings of the National Academy of Sciences (PNAS) represents additional strong evidence from human cells—as opposed ...
VIDEO:
Dr. Gail Smith, a veterinary orthopedic surgeon, discusses the PennHIP method for diagnosing a dog's susceptibility to osteoarthritis.
Click here for more information.
PHILADELPHIA –- A study comparing a University of Pennsylvania method for evaluating a dog's susceptibility to hip dysplasia to the traditional American method has shown that 80 percent of dogs judged to be normal by the traditional method are actually at risk for developing osteoarthritis and hip dysplasia, ...
Virtual characters can behave according to actions carried out unconsciously by humans. Researchers at the University of Barcelona have created a system which measures human physiological parameters, such as respiration or heart rate, and introduces them into computer designed characters in real time.
"The ultimate aim is to develop a method which allows humans to unconsciously relate with some parts of the virtual environment more intensely than with others, and that they are encouraged only by their own physiological responses to the virtual reality shown", Christoph ...
Cluster has spent a decade revealing previously hidden interactions between the Sun and Earth. Its studies have uncovered secrets of aurora, solar storms, and given us insight into fundamental processes that occur across the Universe. And there is more work to do.
The aurora, those dancing lights in the polar skies, are but the visible manifestation of an invisible battle taking place above our heads. Supersonic particles from the Sun collide with our planet's magnetic field every day. Most are deflected away but some are trapped by Earth's magnetism and accelerated to ...
CAMBRIDGE, Mass., Sept. 2, 2010 -- Engineers at Harvard University have created a millionth-scale automobile differential to govern the flight of minuscule aerial robots that could someday be used to probe environmental hazards, forest fires, and other places too perilous for people.
Their new approach is the first to passively balance the aerodynamic forces encountered by these miniature flying devices, letting their wings flap asymmetrically in response to gusts of wind, wing damage, and other real-world impediments.
"The drivetrain for an aerial microrobot shares ...
The Department of Computer Science and Technology, Peking University, Beijing, China, has shown that a novel dynamic memory mapping (DMM) model brings about additional flexibility to virtual resource management, leading to the feature-adjustable design of a virtual machine monitor (VMM). The study is reported in Issue 53 (June, 2010) of SCIENCE CHINA Information Sciences because of its significant research value.
Memory is one of the most frequently accessed components in virtual machine (VM) systems. Because a VM's memory requirement varies according to the running applications, ...
The Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, and China Research have collaborated to reveal the heat treatment effects on the superconducting properties of Ag-doped Sr0.6K0.4Fe2As2 compounds. Because of its significant research value, the study is reported in issue 7 of SCIENCE CHINA Physics, Mechanics & Astronomy.
Previously, our group studied the effect of adding Ag to polycrystalline Sr0.6K0.4Fe2As2 and found that the critical current density Jc and the irreversibility field increase markedly. ...
