How zinc starves lethal bacteria to stop infection

Contact: Dr Christopher McDevitt christopher.mcdevitt@adelaide.edu.au 61-449-823-946 University of Adelaide

Australian researchers have found that zinc can ‘starve’ one of the world’s most deadly bacteria by preventing its uptake of an essential metal.

The finding, by infectious disease researchers at the University of Adelaide and The University of Queensland, opens the way for further work to design antibacterial agents in the fight against Streptococcus pneumoniae.

Streptococcus pneumoniae is responsible for more than one million deaths a year, killing children, the elderly and other vulnerable people by causing pneumonia, meningitis, and other serious infectious diseases.

Published today in the journal Nature Chemical Biology, the researchers describe how zinc “jams shut” a protein transporter in the bacteria so that it cannot take up manganese, an essential metal that Streptococcus pneumoniae needs to be able to invade and cause disease in humans.

“It’s long been known that zinc plays an important role in the body’s ability to protect against bacterial infection, but this is the first time anyone has been able to show how zinc actually blocks an essential pathway causing the bacteria to starve,” says project leader Dr Christopher McDevitt, Research Fellow in the University of Adelaide’s Research Centre for Infectious Diseases.

“This work spans fields from chemistry and biochemistry to microbiology and immunology to see, at an atomic level of detail, how this transport protein is responsible for keeping the bacteria alive by scavenging one essential metal (manganese), but at the same time also makes the bacteria vulnerable to being killed by another metal (zinc),” says Professor Bostjan Kobe, Professor of Structural Biology at The University of Queensland.

The study reveals that the bacterial transporter (PsaBCA) uses a ‘spring-hammer’ mechanism to bind the metals. The difference in size between the two metals, manganese and zinc, causes the transporter to bind them in different ways. The smaller size of zinc means that when it binds to the transporter, the mechanism closes too tightly around the zinc, causing an essential spring in the protein to unwind too far, jamming it shut and blocking the transporter from being able to take up manganese.

“Without manganese, these bacteria can easily be cleared by the immune system,” says Dr McDevitt. “For the first time, we understand how these types of transporters function. With this new information we can start to design the next generation of antibacterial agents to target and block these essential transporters.”

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The research has been funded by the Australian Research Council and the National Health and Medical Research Council.

Media Contact:

Dr Christopher McDevitt Research Fellow Research Centre for Infectious Diseases School of Molecular and Biomedical Science The University of Adelaide Mobile: +61 449 823 946 christopher.mcdevitt@adelaide.edu.au

Professor Bostjan Kobe Professor of Structural Biology Australian Infectious Diseases Research Centre School of Chemistry & Molecular Biosciences The University of Queensland Phone : +61 7 3365 2132 b.kobe@uq.edu.au

Robyn Mills Media Officer The University of Adelaide Phone: +61 8 8313 6341 Mobile: +61 410 689 084 robyn.mills@

Top US climate scientists support development of safe nuclear power

Open letter to environmentalists and world leaders says wind and solar power are not enough to diminish carbon emissions

  •  Associated Press in Pittsburgh
  • theguardian.com,   Sunday 3 November 2013 11.03 EST
Nuclear power plant Gosgen Switzerland

Nuclear power is ‘very divisive’ among environmentalists but scientists argue it’s necessary. Photograph: WoodyStock / Alamy/Alamy

Some of the world’s top climate scientists say wind and solar energy won’t be enough to head off extreme global warming, and they’re asking environmentalists to support the development of safer nuclear power as one way to cut fossil fuel pollution.

Four scientists who have played a key role in alerting the public to the dangers of climate change sent letters Sunday to leading environmental groups and politicians around the world. The letter, an advance copy of which was given to the Associated Press, urges a crucial discussion on the role of nuclear power in fighting climate change.

The letter signers are James Hansen, a former top NASA scientist; Ken Caldeira, of the Carnegie Institution; Kerry Emanuel, of the Massachusetts Institute of Technology; and Tom Wigley, of the University of Adelaide in Australia.

Environmentalists agree that global warming is a threat to ecosystems and humans, but many oppose nuclear power and believe that new forms of renewable energy will be able to power the world within the next few decades. That isn’t realistic, the letter said.

“Those energy sources cannot scale up fast enough” to deliver the amount of cheap and reliable power the world needs, and “with the planet warming and carbon dioxide emissions rising faster than ever, we cannot afford to turn away from any technology” that has the potential to reduce greenhouse gases.

Hansen began publishing research on the threat of global warming more than 30 years ago, and his testimony before Congress in 1988 helped launch a mainstream discussion. Last February he was arrested in front of the White House at a climate protest that included the head of the Sierra Club and other activists.

Caldeira was a contributor to reports from the Intergovernmental Panel on Climate Change, Emanuel is known for his research on possible links between climate change and hurricanes, and Wigley has also been doing climate research for more than three decades.

Emanuel said the signers aren’t opposed to renewable energy sources but want environmentalists to understand that “realistically, they cannot on their own solve the world’s energy problems.”

The vast majority of climate scientists say they’re now virtually certain that pollution from fossil fuels has increased global temperatures over the last 60 years. They say emissions need to be sharply reduced to prevent more extreme damage in the future.

In 2011 worldwide carbon dioxide emissions jumped 3%, because of a large increase by China, the world’s most carbon polluting country. The US is second in carbon emissions.

Hansen, who’s now at Columbia University, said it’s not enough for environmentalists to simply oppose fossil fuels and promote renewable energy.

“They’re cheating themselves if they keep believing this fiction that all we need” is renewable energy such as wind and solar, Hansen told the AP.

The joint letter says, “the time has come for those who take the threat of global warming seriously to embrace the development and deployment of safer nuclear power systems” as part of efforts to build a new global energy supply.

Stephen Ansolabehere, a Harvard professor who studies energy issues, said nuclear power is “very divisive” within the environmental movement. But he added that the letter could help educate the public about the difficult choices that climate change presents.

One major environmental advocacy organization, the Natural Resources Defense Council, warned that “nuclear power is no panacea for our climate woes.”

Risk of catastrophe is only one drawback of nuclear power, NRDC President Frances Beinecke said in a statement. Waste storage and security of nuclear material are also important issues, he said.

“The better path is to clean up our power plants and invest in efficiency and renewable energy.”

The scientists acknowledge that there are risks to using nuclear power, but say those are far smaller than the risk posed by extreme climate change.

“We understand that today’s nuclear plants are far from perfect.”

http://www.theguardian.com/environment/2013/nov/03/climate-scientists-support-nuclear-power

Eating junk food while pregnant may make your child a junk food addict

Contact: Cody Mooneyhan cmooneyhan@faseb.org 301-634-7104 Federation of American Societies for Experimental Biology

New research in The FASEB Journal shows that eating a junk food diet during pregnancy changes the development of the opioid signaling pathway in the baby’s brain, resulting in decreased sensitivity

Bethesda, MD—Here’s another reason why a healthy diet during pregnancy is critical to the future health of your children: New research published in the March 2013 issue of The FASEB Journal, suggests that pregnant mothers who consume junk food actually cause changes in the development of the opioid signaling pathway in the brains of their unborn children. This change results in the babies being less sensitive to opioids, which are released upon consumption of foods that are high in fat and sugar. In turn, these children, born with a higher “tolerance” to junk food need to eat more of it to achieve a “feel good” response.

“The results of this research will ultimately allow us to better inform pregnant women about the lasting effect their diet has on the development of their child’s lifelong good preferences and risk of metabolic disease,” said Beverly Muhlhausler, Ph.D., a researcher involved in the work from the FOODplus Research Centre at the School of Agriculture Food and Wine at The University of Adelaide in Adelaide, Australia.  “Hopefully, this will encourage mothers to make healthier diet choices which will lead to healthier children.”

To make this discovery, Muhlausler and colleagues studied the pups of two groups of rats, one of which had been fed a normal rat food and the other which had been fed a range of human “junk foods” during pregnancy and lactation. After weaning, the pups were given daily injections of an opioid receptor blocker, which blocks opioid signaling. Blocking opioid signaling lowers the intake of fat and sugar by preventing the release of dopamine. Results showed that the opioid receptor blocker was less effective at reducing fat and sugar intake in the pups of the junk food fed mothers, suggesting that the opioid signaling pathway in these offspring is less sensitive than for pups whose mothers are eating a standard rat feed.

“This study shows that addiction to junk food is true addiction.” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. “Junk food engages the same body chemistry as opium, morphine or heroin. Sad to say, junk food during pregnancy turns the kids into junk food junkies.”

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Receive monthly highlights from The FASEB Journal by e-mail. Sign up at http://www.faseb.org/fjupdate.aspx. The FASEB Journal is published by the Federation of the American Societies for Experimental Biology (FASEB). It is among the most cited biology journals worldwide according to the Institute for Scientific Information and has been recognized by the Special Libraries Association as one of the top 100 most influential biomedical journals of the past century. FASEB is composed of 26 societies with more than 100,000 members, making it the largest coalition of biomedical research associations in the United States. Its mission is to advance health and welfare by promoting progress and education in biological and biomedical sciences through service to its member societies and through collaborative advocacy.

Details: Jessica R. Gugusheff, Zhi Yi Ong, and Beverly S. Muhlhausler. A maternal “junk-food” diet reduces sensitivity to the opioid antagonist naloxone in offspring postweaning.  FASEB J March 2013 27:1275-1284, doi:10.1096/fj.12-217653  ;  http://www.fasebj.org/content/27/3/1275.abstract

 

Extending Einstein’s Theory Beyond Light Speed

Researchers have extended Einstein’s theory of special relativity to work beyond the speed of light. (Credit: © vlights / Fotolia)

ScienceDaily (Oct. 10, 2012) — University of Adelaide applied mathematicians have extended Einstein’s theory of special relativity to work beyond the speed of light.

Einstein’s theory holds that nothing could move faster than the speed of light, but Professor Jim Hill and Dr Barry Cox in the University’s School of Mathematical Sciences have developed new formulas that allow for travel beyond this limit.

Einstein’s Theory of Special Relativity was published in 1905 and explains how motion and speed is always relative to the observer’s frame of reference. The theory connects measurements of the same physical incident viewed from these different points in a way that depends on the relative velocity of the two observers.

“Since the introduction of special relativity there has been much speculation as to whether or not it might be possible to travel faster than the speed of light, noting that there is no substantial evidence to suggest that this is presently feasible with any existing transportation mechanisms,” said Professor Hill.

“About this time last year, experiments at CERN, the European centre for particle physics in Switzerland, suggested that perhaps neutrinos could be accelerated just a very small amount faster than the speed of light; at this point we started to think about how to deal with the issues from both a mathematical and physical perspective.

“Questions have since been raised over the experimental results but we were already well on our way to successfully formulating a theory of special relativity, applicable to relative velocities in excess of the speed of light.

“Our approach is a natural and logical extension of the Einstein Theory of Special Relativity, and produces anticipated formulae without the need for imaginary numbers or complicated physics.”

The research has been published in the Proceedings of the Royal Society A in a paper, ‘Einstein’s special relativity beyond the speed of light’. Their formulas extend special relativity to a situation where the relative velocity can be infinite, and can be used to describe motion at speeds faster than light.

“We are mathematicians, not physicists, so we’ve approached this problem from a theoretical mathematical perspective,” said Dr Cox. “Should it, however, be proven that motion faster than light is possible, then that would be game changing.

“Our paper doesn’t try and explain how this could be achieved, just how equations of motion might operate in such regimes.”

http://www.sciencedaily.com/releases/2012/10/121010092742.htm

 

Zinc supplements during pregnancy may counteract damage from early alcohol exposure

2009 study posted for filing

Contact: Peter Coyle, Ph.D.
61-8-8222-3028
peter.coyle@imvs.sa.gov.au
Hanson Institute

Alcoholism Clinical and Experimental Research

Animal research has shown that binge drinking – even just once – during early pregnancy can cause numerous problems for the fetus, including early postnatal death. Fetal zinc deficiency may explain some of the birth defects and neurodevelopmental abnormalities associated with alcohol exposure. New rodent findings are the first to show that dietary zinc supplements throughout pregnancy can reduce some alcohol-related birth defects.

Results will be published in the April issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.

“Alcohol’s damage to the fetus depends not only on the amount and duration of alcohol exposure, but also on the timing of the exposure relative to the development stage of the cells and tissues involved,” said Peter Coyle, associate professor at the Hanson Institute in Adelaide, and corresponding author for the study. “Earlier work had shown that prenatal alcohol, as well as other toxins, can result in fetal zinc deficiency and teratogenicity by inducing the zinc-binding protein, metallothionein, in the mother’s liver. Since then, our group has confirmed the importance of metallothionein in alcohol-mediated birth defects.”

Coyle and his colleagues injected pregnant mice with either saline or a 25-percent solution of alcohol on gestational day (GD) eight; all mice received either a regular or zinc-supplemented diet from GD zero to 18. On GD 18, fetuses from all four groups – saline, saline plus zinc, alcohol, alcohol plus zinc – were assessed for external birth abnormalities. In addition, from birth to day 60, researchers examined the growth of survivors from all four groups.

“There were three key findings,” said Coyle. “One, fetal abnormalities caused by acute alcohol exposure in early pregnancy can be prevented by dietary zinc supplementation. Two, dietary zinc supplementation throughout pregnancy can protect against post-natal death caused by acute alcohol exposure in early pregnancy. Three, dietary zinc supplementation increases the mother’s blood zinc to overwhelm the transient drop in zinc caused by alcohol, which we believe prevents the fetal zinc deficiency and subsequent fetal damage.”

Coyle added that the rodents’ GD eight is the equivalent of weeks three to eight during a human pregnancy. “This encompasses a period when the mother is often unaware of her pregnancy and may not have changed her drinking habits,” he said. “Moreover, up to 60 percent of pregnancies are unplanned. This latter point is of concern when noting that binge drinking is common in the community and more likely to occur in the first trimester than later.”

Importantly, Coyle emphasized, his team is not suggesting that it is safe to drink while taking zinc during pregnancy.

“We have not determined whether zinc protects against all of the possible negative outcomes from alcohol exposure in pregnancy,” he said. “Nor would we recommend that makers of alcoholic beverages include zinc in their product so that women can drink while pregnant. Indeed, we take the conservative stand of a ‘no alcohol policy’ during pregnancy. What our studies do indicate is that dietary zinc supplementation could be as important as folic acid and applied as a simple prophylactic treatment in the human setting to prevent the effects of a range of insults in pregnancy.”

While zinc supplementation is relatively common, and zinc tablets can easily be found in herbal shops, Coyle cautioned that zinc can also affect the absorption of other trace elements and cause anemia if taken in excess. “So one must be wary of taking zinc supplements without professional oversight, and this is particularly so in pregnancy,” he said.

“Furthermore,” he added, “although dietary zinc supplementation has been used in human pregnancy, we do not have any information regarding the dose that would be required to protect against damage from alcohol nor even the dosage that could be harmful to fetal development. Indeed, we have not tested our hypothesis in humans and so it would be unwise to extrapolate any of our findings to humans. We would predict that zinc supplementation would only be effective around the time of alcohol intake to prevent fetal zinc deficiency. Taking zinc supplements a day after alcohol consumption would probably be too late to prevent fetal damage. Obviously more research is needed.”

 

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Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. Co-authors of the ACER paper, “Dietary Zinc Supplementation throughout Pregnancy Protects against Fetal Dysmorphology and Improves Postnatal Survival after Prenatal Ethanol Exposure in Mice,” were: Brooke L. Summers of the Hanson Institute/Institute of Medical and Veterinary Science, and of the Discipline of Physiology in the School of Molecular and Biomedical Science at the University of Adelaide; and Allan M. Rofe of the Hanson Institute/Institute of Medical and Veterinary Science. The study was funded by the Channel Seven Children’s Research Foundation of South Australia, Inc.

Processed food diet in early childhood may lower subsequent IQ

Contact: Emma Dickinson edickinson@bmjgroup.com 44-207-383-6529 BMJ-British Medical Journal

Are dietary patterns in childhood associated with IQ at 8 years of age? A population-based cohort study

A diet, high in fats, sugars, and processed foods in early childhood may lower IQ, while a diet packed full of vitamins and nutrients may do the opposite, suggests research published online in the Journal of Epidemiology and Community Health.

The authors base their findings on participants in the Avon Longitudinal Study of Parents and Children (ALSPAC), which is tracking the long term health and wellbeing of around 14,000 children born in 1991 and 1992.

Parents completed questionnaires, detailing the types and frequency of the food and drink their children consumed when they were 3, 4, 7 and 8.5 years old.

Three dietary patterns were identified: “processed” high in fats and sugar intake; “traditional” high in meat and vegetable intake; and “health conscious” high in salad, fruit and vegetables, rice and pasta. Scores were calculated for each pattern for each child.

IQ was measured using a validated test (the Wechsler Intelligence Scale for Children) when they were 8.5 years old. In all, complete data were available for just under 4,000 children.

The results showed that after taking account of potentially influential factors, a predominantly processed food diet at the age of 3 was associated with a lower IQ at the age of 8.5, irrespective of whether the diet improved after that age. Every 1 point increase in dietary pattern score was associated with a 1.67 fall in IQ.

On the other hand, a healthy diet was associated with a higher IQ at the age of 8.5, with every 1 point increase in dietary pattern linked to a 1.2 increase in IQ. Dietary patterns between the ages of 4 and 7 had no impact on IQ.

The authors say that these findings, although modest, are in line with previous ALSPAC research showing an association between early childhood diet and later behaviour and school performance.

“This suggests that any cognitive/behavioural effects relating to eating habits in early childhood may well persist into later childhood, despite any subsequent changes (including improvements) to dietary intake,” they say.

The brain grows at its fastest rate during the first three years of life, say the authors, by way of a possible explanation for the findings, adding that other research has indicated that head growth at this time is linked to intellectual ability.

“It is possible that good nutrition during this period may encourage optimal brain growth,” they suggest, advocating further research to determine the extent of the effect early diet has on intelligence.

* Repsoted at Request