Germany - Smokers may have more sleep problems: Study

Smokers may get fewer hours of sleep and have less restful slumber than non-smokers, according to a German study that looked at more than two thousand people.

Researchers whose work appeared in the journal Addiction Biology found that of nearly 1,100 smokers surveyed, 17 per cent got fewer than six hours of sleep each night and 28 per cent reported "disturbed" sleep quality.

That compared with rates of seven per cent and 19 per cent respectively among more than 1,200 non-smokers who were also surveyed, said lead researcher Stefan Cohrs, of Charite Berlin medical school in Germany.

"This study demonstrates for the first time an elevated prevalence of sleep disturbance in smokers compared with non-smokers in a population without lifetime history of psychiatric disorders even after controlling for potentially relevant risk factors," Cohrs and his colleagues wrote.

The findings cannot prove that smoking directly impairs sleep, since smokers may have other habits that could affect their shut-eye such as staying up late to watch TV or getting little exercise, Cohrs told Reuters Health in an email.

But there is also reason to believe the stimulating effects of nicotine may be to blame.

"If you smoke and you do suffer from sleep problems, it is another good reason to quit smoking," Cohrs said.

Poor sleep quality may not only make your waking hours tougher. Some studies have also linked habitually poor sleep to health problems like obesity, diabetes and heart disease.

The study included 1,071 smokers and 1,243 non-smokers who were free of mental health disorders, since those conditions may make a person both more likely to smoke and more vulnerable to sleep problems.

The researchers used a questionnaire that gauges sleep quality. Overall, more than one-quarter of smokers had a score than landed them in the category of "disturbed" sleep, meaning they had a high probability of insomnia.

Many things can affect sleep quality, and Cohrs's team was able to account for factors such as age, weight, and alcohol abuse. Yet smoking was still linked to poorer sleep quality.

It's still possible there are other things about smokers that impair their sleep, but Cohrs said he thinks the most likely culprit is nicotine - and the prospect of better sleep could provide smokers with an additional reason to quit.

Reuters

Germany - Dioxin found in eggs on another German farm

HAMBURG - The poisonous chemical dioxin had been found above permitted levels in eggs from a German farm following discoveries at six other farms in the country in April and May, officials said on Wednesday.

The poultry farm is in the Emsland area in the north German state of Lower Saxony, the state agriculture ministry said.

The farm with its 12,000 chickens has been quarantined and its eggs recalled from sale, it said. The dioxin was discovered by the farm's own safety checks.

The ministry said there was no acute danger to public health because dioxin is dangerous only if consumed over long periods.

Small doses are not harmful.

The previous dioxin discoveries were in eggs at farms in Lower Saxony and the neighbouring state of North Rhine Westphalia.

In January 2011, an European Union-wide health alert was sparked when German officials said animal feed tainted with dioxin had been fed to hens and pigs, contaminating eggs, poultry meat and pork at affected farms.

Germany then introduced a series of measures including restrictions on animal feed ingredients and increased inspections of farms and feed.

Reuters

Germany - Google goes cancer: Researchers use search engine algorithm to find cancer biomarkers

The strategy used by Google to decide which pages are relevant for a search query can also be used to determine which proteins in a patient's cancer are relevant for the disease progression.

Researchers from Dresden University of Technology, Germany, have used a modified version of Google's PageRank algorithm to rank about 20,000 proteins by their genetic relevance to the progression of pancreatic cancer. In their study, published in PLoS Computational Biology, they found seven proteins that can help to assess how aggressive a patient's tumor is and guide the clinician to decide if that patient should receive chemotherapy or not.

The researcher's own version of the Google algorithm has been used in this study to find new cancer biomarkers, which are molecules produced bycancer cells. Biomarkers can help to detect cancer earlier in body fluids or directly in the cancer tissue obtained in an operation or biopsy. Finding these biomarkers is often difficult and time consuming. Another problem is that markers found in different studies for the same types of cancer almost never overlap.

This problem has been circumvented using the Google strategy, which takes into account the content of a web page and also how these pages are connected via hyperlinks. With this strategy as the model, the authors made use of the fact that proteins in a cell are connected through a network of physical and regulatory interactions; the 'protein Facebook' so to speak.

"Once we added the network information in our analysis, our biomarkers became more reproducible," said Christof Winter, the paper's first author. Using this network information and the Google Algorithm, a significant overlap was found with an earlier study from the University of North Carolina. There, a connection was made with a protein which can assess aggressiveness in pancreatic cancer.

Although the new biomarkers seem to mark an improvement over currently used diagnostic tools, they are far from perfect and still need to be validated in a larger follow-up study before they can be used in clinical practice. It remains an open problem to turn these insights into novel drugs which slow down cancer progression. A first step in this direction is the group's cooperation with the Dresden-based biotech company RESprotect, who are running a clinical trial on a pancreas cancer drug.

TU Dresden is a leading German university, whose Center for Regenerative Therapies was awarded excellence status in the national excellence initiative. The work was a cooperation between the bioinformatics group of Prof. Dr. Michael Schroeder and the medical groups of Dr. Christian Pilarsky and Prof. Robert Grützmann.

More information: Winter C, Kristiansen G, Kersting S, Roy J, Aust D, et al. (2012) Google Goes Cancer: Improving Outcome Prediction for Cancer Patients by Network-Based Ranking of Marker Genes. PLoS Comput Biol 8(5): e1002511. doi:10.1371/journal.pcbi.1002511

Journal reference: PLoS Computational Biology   

Provided by Public Library of Science

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Germany - Scientists aim to kill lung tumors

This image shows the formation of PDE4 in oxygen-deficient lung tumor cells. Lung cells produce PDE4 (stained green: left) even if their oxygen content is normal. More PDE4 is produced (right) if they are oxygen-deficient (hypoxia). The cell nuclei are stained blue. Credit: MPI for Heart and Lung Research

Lung cancer is the leading cause of cancer death throughout the world. Standard treatment methods do not usually result in long-term recovery. In addition to the proliferation of the tumour cells, the growth of blood vessels controls tumors development. The blood vessel growth is controlled by several signalling molecules.

Scientists from the Max Planck Institute for Heart and Lung Research in Bad Nauheim and Justus Liebig University Giessen have discovered a molecule that plays a key role in this process. They succeeded in reducing tumour growth in their experiments by blocking the phosphodiesterase PDE4.

Lung cancer mainly affects smokers; however the disease can also be caused by contact with carcinogenic substances like asbestos. Chemotherapy or radiotherapy often prove insufficient in treating the disease. Hence, scientists are engaged in an intensive search for ways of halting the growth of lung tumours. The blood vessels that supply the tumour with nutrients offer a potential point of attack.

New blood vessels form to ensure an adequate supply of nutrients to the growing tumour. The growing tissue is immediately penetrated by blood vessels. The growth of the blood vessels is regulated by the tumour cells using a complex signal cascade, which is triggered initially by a low oxygen content (hypoxia) in the tumour tissue.

"This state, which is known as hypoxia prompts the activation of around 100 genes in the tumour cells," explains Rajkumar Savai, research group leader at the Max Planck institute. "In addition to the growth of blood vessels, hypoxia also stimulates the proliferation of lung cancer cells." Three molecules play a particularly important role in this process. The activation of the genes at the beginning of the cascade is triggered by the transcription factor HIF and a messenger molecule, cAMP, is involved again at the end of the cascade. The researchers examined the third molecule that acts as a link between these two molecules in detail.

The molecule in question is a phosphodiesterase, PDE4. The scientists from Bad Nauheim and Giessen were able to demonstrate in their study that various sections of PDE4 have binding sites for HIF.

The researchers then tested the influence of a PDE4 blockade on the cells from ten different cell lines, which are characteristic of around 80 percent of lung cancers, in the laboratory. The rate of cell division in the cells treated with a PDE4 inhibitor was significantly lower and the HIF level also declined as a result.

The effect in the tumour bearing mice was particularly obvious. To observe this, the Max Planck researchers implanted a human tumour cell line under the skin of nude mice and treated the animals with the phosphodiesterase 4 inhibitor.

Tumour growth in these animals declined by around 50 percent. "Our microscopic analysis revealed that the blood vessel growth in the tumours of the mice that had been treated with the inhibitor was significantly reduced. We also observed indicators of decelerated cell division in the tumour cells. Overall, the tumour growth was strongly curbed."

Werner Seeger, Director of the MPI and Medical Director of the JLU University Hospital Giessen, reports:

"We were able to show that PDE4 plays an important regulation function in cell division in lung tumours and in the development of blood vessels in cancer. Therefore, we hope that we have found a starting point for the development of a treatment here."

In the view of tumour specialist Friedrich Grimminger, Chairman of the Department of Medical Oncology in Giessen, it may be possible in future to combine the inhibition of PDE4 with traditional radiotherapy or chemotherapy.

In this way, the effect of the traditional treatment measures could be reinforced and patient prognoses may improve as a result. However, further laboratory studies are required before clinical tests can be carried out.

More information: Oncogene (2012). doi:10.1038/onc.2012.136

Provided by Max Planck Society (news : web)

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Germany - Precise molecular surgery in the plant genome

Thale cress blossom: Common thale cress (Arabidopsis thaliana) is used as a model plant in many biotechnology experiments. Credit: Photo: H. Puchta/ KIT

Crop plants have always been adapted to the needs of man by breeding for them to carry more fruit, survive droughts, or resist pests. Green biotechnology now adds new tools to the classical breeding methods for a more rapid and efficient improvement of plant properties.

A biotechnological technique developed by KIT botanists to more precisely and reliably install or modify genetic information in the plant genome is now presented by the expert journal PNAS.

The new method is based on the natural repair mechanism of plants. So-called homologous recombination repairs the genome when the genome strands in the cell break. "Using an appropriate enzyme, i.e. molecular scissors, we first make a cut at the right point in the genome and then supply the necessary patch to repair this cut," says Friedrich Fauser from Karlsruhe Institute of Technology, who is the first author of the PNAS publication. "A part of this patch is the new gene piece we want to install. The rest is done by the repair service of the cell."

Due to this trick, the method that is referred to as "in planta gene targeting" (IPGT) is highly reliable and the new genetic information is incorporated in the genome precisely at the point desired. In principle, IPGT may be applied to every plant. "This is a big advantage compared to conventional methods that work for certain plants only and produce a lot of rejects," explains Professor Holger Puchta, who holds the Chair for Molecular Biology and Biochemistry of Plants at Karlsruhe Institute of Technology. "Thanks to appropriate molecular scissors and patches and the natural repair mechanism of the cell, IPGT is about 100 times more efficient than techniques used so far."

With their experiments on the model plant of thale cress (Arabidopsis thaliana), the researchers of KIT, in cooperation with the company SunGene GmbH, a subsidiary of BASF Plant Science having its office at Gatersleben, have now succeeded in furnishing evidence of the fact that IPGT works in plants. "The next step towards broader application in biotechnolgoy will be the transfer of the principle to other plants and the development of appropriate scissors and patches," says Puchta. In this way, the favorable properties of wild species can be transferred rapidly to crop plants. The long-term objective is the optimum use of natural resources for the production of food and vegetable raw materials.

More information: PNAS: http://www.pnas.org/

Provided by Helmholtz Association of German Research Centres (news :web)

http://phys.org

Germany - Uric acid levels predict death in acute coronary syndrome

Elevated uric acid levels are predictive of one-year mortality in patients with acute coronary syndrome, according to a study published in the May 1 issue of The American Journal of Cardiology.

Gjin Ndrepepa, M.D., of the Deutsches Herzzentrum in Munich, Germany, and colleagues conducted a study involving 5,124 patients with acute coronary syndrome who underwent percutaneous coronary intervention (PCI) to evaluate whether uric acid levels have any prognostic value in this patient population.

Of the participants, 1,629 had acute ST-segment elevation myocardial infarction (STEMI), 1,332 had acute non-STEMI, and 2,163 had unstable angina. Participants were classified into four uric acid quartiles: quartile 1 (1.3 to <5.3 mg/dL), quartile 2 (5.3 to <6.3 mg/dL), quartile 3 (6.3 to <7.5 mg/dL), and quartile 4 (7.5 to 18.4 mg/dL). One-year mortality was the primary end point.

During follow-up, the researchers identified 450 deaths: 80 deaths in quartile 1, 77 in quartile 2, 72 in quartile 3, and 221 in quartile 4 (unadjusted hazard ratio, 3.05 for fourth versus first quartile uric acid).

The association between uric acid and mortality persisted after adjustment, with every 1-mg/dL increase in the uric acid level correlating with a 12 percent increase in the adjusted risk for one-year mortality.

"Elevated levels of uric acid are an independent predictor of one-year mortality across the whole spectrum of patients with acute coronary syndromes treated with percutaneous coronary intervention," the authors write.

More information: The American journal of cardiology, 1 May 2012, v. 109, 9 , pp. 1260-1265. DOI: 10.1016/j.amjcard.2011.12.018)

Copyright © 2012 HealthDay. All rights reserved.

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Germany - Brain scans reveal differences in regret as people age

New research using brains scans shows that many elderly people have over time either learned to not stew over things they regret or to not regret them at all.

Those that don’t learn such skills tend to become depressed, say researchers from University Medical Center in Germany, who have been conducting research into regret and aging using brain scans. The team, led by Stefanie Brassen has published the results of their efforts in the journal Science.

In their report, the team finds that young people and depressed older adults tend to rue decisions they’ve made and to fixate on them. In contrast, mentally healthy older adults tend to call it all water under the bridge and move on.

To find out such things, the team recruited sixty volunteers, 20 healthy young people, 20 mentally healthy elderly people and 20 elderly people who suffer from depression, to help them carry out an experiment.

They asked each volunteer to play a video game of chance that involved several covered containers. Under each was either a gold ingot or a demon that would steal all the money they’d earned thus far. As each container was opened, the player got to keep the gold if it was underneath.

As play progressed the odds of finding a demon increased, upping the anxiety. Also, to see what was going on in the brain, players played the game while being scanned inside of an MRI machine.

The researchers looked specifically at the brain region known as the ventral striatum, which is known to respond to rewards. In analyzing the players, the researchers found that young people and older depressed adults tended to show more activity than did the brains of older more complacent older people.

By watching carefully, they could also measure the impact on players when they felt they opted out too early, or when they kept on playing but eventually lost all they’d won to the demon.

This time, the younger players and those that were older but depressed showed less activity in the ventral striatum, indicating sadness or depression, meaning they were upset about how things had come out.

The older, healthier players on the other hand showed little to no change, indicating they weren’t nearly as worried or upset about how things had played out.

The team also found by looking at the anterior cingulate cortex, that older healthy adults did actually feel some remorse at some points in the game, but suppressed it.

The researchers repeated the whole exercise with another group of volunteers, only instead of testing them with an MRI machine, they tested their heart rates and skin for electrical response (indicating degree of sweating) during play.

This time too they found that the older healthier players were more relaxed regardless of outcome, while the young people and older depressed people tended to sweat it out both while playing and then when reacting to the results of their own decision making.

And finally, to put it all together, the team interviewed the volunteers asking them if they had a lot of regrets and how strong those feelings were if they hand them. Not surprisingly, the volunteers answers tended to mirror the results of the earlier experiments.

These results, the researchers say, show that as people grow older, those that do so in a healthy manner learn to not dwell on past mistakes or to suppress negative feelings about them, while those that don’t tend to become depressed.

More information: Science DOI: 10.1126/science.1217516

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Germany - Skin and Umbilical Cord Cells Turned Directly Into Nerve Cells

Until recently, the production of pluripotent "multipurpose" stem cells from skin cells was considered to be the ultimate new development. In the meantime, it has become possible to directly convert cells of the body into one another -- without the time-consuming detour via a pluripotent intermediate stage.

However, this method has so far been rather inefficient. Scientists from the Bonn Institute of Reconstructive Neurobiology (Director: Prof. Dr. Oliver Brüstle) have now developed the method to the point that it can be used for biomedical applications.

The scientists are presenting their results in the journal Nature Methods.

There was much excitement surrounding cell reprogramming with the breakthrough of Shinya Yamanaka. In 2006, the Japanese scientist was able to reprogram skin cells for the first time with the aid of a few control factors into so-called induced pluripotent stem cells (iPS cells) -- "multipurpose" cells from which all body cells can in principle be produced. In 2010,

Marius Wernig, a former postdoctoral researcher with Prof. Brüstle and meanwhile the director of the institute at Stanford University in California, developed the idea further: Using only three so-called transcription factors, his team was able to perform direct transformation of skin cells into so-called induced neurons (iN). However, the method has so far been rather inefficient: Only a small percentage of the skin cells were converted into the desired nerve cells.

Researchers are increasing yields during transformation of cells

For the scientists at the LIFE & BRAIN Center at the University of Bonn, that was not enough. They are interested in the biomedical utilization of artificially produced human nerve cells for disease research, cell replacement, and the development of active substances. One concept seemed likely: Why not use low-molecular active substances -- so-called small molecules -- to optimize the process? Julia Ladewig, post-doctoral researcher and lead author of the study, began using such active substances to influence several signaling pathways important for cell development.

By blocking the so-called SMAD signaling pathway and inhibiting glycogen synthase kinase 3 beta (GSK3ß), they increased the transformational efficiency by several times -- and were thus able to even simplify the means of extraction. Using only two instead of previously three transcription factors and three active substances, the Bonn researchers were able to convert a majority of the skin cells into neurons. In the end, their cell cultures contained up to more than 80% human neurons. And since the cells divide even further during the conversion process, the actual efficiency is even higher.

Two nerve cells are produced from one skin cell

"We can obtain up to more than 200,000 nerve cells converted in this way from 100,000 skin cells," says Julia Ladewig. In order to find the right combination of active substances, the Bonn scientists are focusing on signaling pathways which are especially important for cell specialization.

"The SMAD signaling pathway and also GSK3ß were suspected of inhibiting the conversion of connective tissue cells and pluripotent stem cells into neural cells. The obvious step was to block both of them using corresponding active substances," says Philipp Koch, team leader and senior author responsible for the study, together with Prof. Brüstle.

The results were intriguing: "We were able to demonstrate how the genes typical for skin fibroblast were gradually down-regulated and nerve-cell-specific genes were activated during the cell transformation. In addition, the nerve cells thus obtained were functionally active, which also makes them interesting as a source for cell replacement," says Ladewig.

Scientists are now transferring the method to other types of cells

The Bonn scientists have already transferred the method to other types of cells such as, for example, umbilical cord cells. Brüstle clearly foresees the next steps: "First of all, we want to use nerve cells obtained in this way for disease and active substance research. The long-term goal will be to convert cells directly in the body into nerve cells."

ScienceDaily