Labslink Research News

great tool to find conference and courses

Sat, 28 Apr 2012 02:36:59 PDT

Hey guys

Some people working at the NKI (Netherlands Cancer Institute) have setup a
search engine for scientific meetings. check the description and the website
as well, if interested...
This website, called biomeeter (www.biomeeter.com) is really well done as it
gives a nice overview of the upcoming meetings organized, and the search can
be done by field or keyword, or even by location (as it's always possible to
combine business with pleasure ;-)).
Another great characteristic of Biomeeter is that you can add yourself
meetings to the website and share the info. And last but not least: you can
get informed with an email alert about upcoming meetings in your field.
So, check it out and if you like it, spread the word in your lab and
institute!

Fly eye paves the way for manufacturing biomimetic surfaces

Wed, 28 Jul 2010 04:16:29 PDT

Rows of tiny raised blowfly corneas may be the key to easy manufacturing of biomimetic surfaces, surfaces that mimic the properties of biological tissues, according to a team of Penn State researchers. "Bioreplication began about 2001 or 2002," said Akhlesh Lakhtakia, Godfrey Binder Professor of Engineering Science and Mechanics. "All the techniques currently available are not conducive to mass replications. In many cases you can make as many replicas as you want, but you need an insect for each replication. This is not good for industrial purposes." Lakhtakia, working with Drew Patrick Pulsifer, graduate student in engineering science and mechanics; Carlo G. Pantano, distinguished professor of materials science and engineering and director of Penn State's Materials Research Institute; and Raúl José Martín-Palma, professor of applied physics, Universidad Autónomia de Madrid, Spain, developed a method to create macroscale molds or dies that retain nanoscale features. "We needed an object large enough to manipulate that still had nanoscale features," said Lakhtakia. The researchers chose blowfly eyes because they have potential application in the manufacture of solar cells. Blowflies have compound eyes that are roughly hemispherical; but within that half sphere, the surface is covered by macroscale hexagonal eyes with nanoscale features. "These eyes are perfect for making solar cells because they would collect more sunlight from a larger area rather than just light that falls directly on a flat surface," said Lakhtakia. However, in order to work in a manufactured product, the surface needs to retain the overall design in sufficient detail. The researchers fixed the fly corneas on a glass substrate and filled the back of the corneas with polydimethylsiloxane, a silicone-based organic polymer, so that the metal covering they apply would not seep behind the eyes. They then deposited nickel on the surface using a modified form of the conformal-evaporated-film-by-rotation technique. In this technique, the researchers thermally evaporate the material that forms the coating in a vacuum chamber. The object receiving the coating is fixed to a holder and rotated about once every two seconds. The researchers used arrays of nine blowfly eyes coated with 250 nanometers of nickel. This initial template was then electroformed -- a method of electroplating -- to deposit nickel on the back to create a master template half a millimeter thick. The thickness of the master template can be thicker. "Polymer replicas produced . . . by casting did faithfully reproduce features of a few micrometers and larger in dimensions," the researchers reported in the online edition of Bioinspiration & Biomimetics. The master template can be used either as a die to stamp the pattern or as a mold. The intention is to use the master die/mold to produce not only daughter dies/molds, but to tile the templates so that they can imprint large areas. The researchers will probably expand their template to include 30 blowfly corneas. "One of the nice things about a conformal coating like this is, it becomes nanograined," said Lakhtakia. "The surface of the die becomes very smooth so the polymer will probably not stick." Many biological surfaces exist that could create manufacture surfaces for a variety of applications. The researchers are currently looking at butterfly wings to understand how the surfaces create colors without pigment. "Interestingly, the emerald ash borer, an insect that has recently become a problem in Pennsylvania, mates by color," said Lakhtakia. "Would lures made from templates of the ash borer skin attract males?"

Researchers discover how key enzyme repairs sun-damaged DNA

Mon, 26 Jul 2010 06:50:14 PDT

Researchers have long known that humans lack a key enzyme -- one possessed by most of the animal kingdom and even plants -- that reverses severe sun damage. For the first time, researchers have witnessed how this enzyme works at the atomic level to repair sun-damaged DNA. The discovery holds promise for future sunburn remedies and skin cancer prevention. In the early online edition of the journal Nature, Ohio State University physicist and chemist Dongping Zhong and his colleagues describe how they were able to observe the enzyme, called photolyase, inject a single electron and proton into an injured strand of DNA. The two subatomic particles healed the damage in a few billionths of a second. "It sounds simple, but those two atomic particles actually initiated a very complex series of chemical reactions," said Zhong, the Robert Smith Associate Professor of Physics, and associate professor in the departments of chemistry and biochemistry at Ohio State. "It all happened very fast, and the timing had to be just right." Exactly how photolyases repair the damage has remained a mystery until now. "People have been working on this for years, but now that we've seen it, I don't think anyone could have guessed exactly what was happening," Zhong said. He and his colleagues synthesized DNA in the lab and exposed it to ultraviolet light, producing damage similar to that of sunburn, then added photolyase enzymes. Using ultrafast light pulses, they took a series of "snapshots" to reveal how the enzyme repaired the DNA at the atomic level. Ultraviolet (UV) light damages skin by causing chemical bonds to form in the wrong places along the DNA molecules in our cells. This study has revealed that photolyase breaks up those errant bonds in just the right spots to cause the atoms in the DNA to move back into their original positions. The bonds are then arranged in such a way that the electron and proton are automatically ejected out of the DNA helix and back into the photolyase, presumably so it could start the cycle over again and go on to heal other sites. All plants and most animals have photolyase to repair severe sun damage. Everything from trees to bacteria to insects enjoys this extra protection. Only mammals lack the enzyme. Humans do possess some enzymes that can undo damage with less efficiency. But we become sunburned when our DNA is too damaged for those enzymes to repair, and our skin cells die. Scientists have linked chronic sun damage to DNA mutations that lead to diseases such as skin cancer. Now that researchers know the mechanism by which photolyase works, they might use that information to design drugs or lotions that heal sun damage, Zhong said. Normal sunscreen lotions convert UV light to heat, or reflect it away from our skin. A sunscreen containing photolyase could potentially heal some of the damage from UV rays that get through. Perhaps ironically, photolyase captures light of a different wavelength -- visible light, in the form of photons -- to obtain enough energy to launch the healing electron and proton into the DNA that has been damaged by UV light. Researchers knew that visible light played a role in the process -- hence the term "photo" in the enzyme's name -- but nobody knew exactly how, until now.

Researchers identify a fundamental process in lysosomal function and protein degradation

Wed, 16 Jun 2010 03:24:49 PDT

Proteins are the building blocks and machines of life. Tens of thousands of them are present in each cell, where they perform essential tasks for the organism. Once they have fulfilled their function, they must be degraded to avoid causing damage. One way in which proteins can be degraded is via the digestion processes inside tiny cellular organelles, the lysosomes. The transport of the proteins destined for degradation to these cellular “trash bins” is partly carried out by endosomes, which deliver proteins from the cell surface to the cell interior. The functionality of both endosomes and lysosomes depends on the ion concentration within their membrane-enclosed interior. In particular, an important role is ascribed to a high concentration of hydrogen ions, i.e. an acidic pH, inside those organelles. The two studies by Dr. Stefanie Weinert, Dr. Gaia Novarino and Professor Thomas Jentsch focus on two ion transport proteins, the chloride transporters ClC-5 and ClC-7. These are located in the membrane of endosomes and/or lysosomes and exchange negatively charged chloride ions for positively charged hydrogen ions (protons). ClC-5 is located in the membrane of endosomes in renal cells. If ClC-5 is defective or lacking altogether, proteins can hardly be absorbed from the urine any longer. In a cascade of indirect mechanisms, this leads to the development of kidney stones in Dent’s disease.......> Full story

MIT chemists design new way to fluorescently label proteins

Wed, 02 Jun 2010 03:23:59 PDT

Since the 1990s, a green fluorescent protein known simply as GFP has revolutionized cell biology. Originally found in a Pacific Northwest jellyfish, GFP allows scientists to visualize proteins inside of cells and track them as they go about their business. Two years ago, biologists who discovered and developed the protein as a laboratory tool won a Nobel Prize for their work.

However, using GFP as a fluorescent probe has one major drawback — the protein is so bulky that it can interfere with the proteins it’s labeling, preventing them from doing their normal tasks or reaching their intended destinations.

“For a long time, people have been trying to find better ways to label proteins,” says Katharine White, an MIT graduate student in the lab of Alice Ting, associate professor of chemistry.

Ting, White and their colleagues have now come up with a new way to overcome the disadvantages of GFP, by tagging proteins with a much smaller probe. Their probe allows proteins to carry out their normal functions, offering scientists the chance to glimpse never-before-seen activity.......> Full story

Detailed metabolic profile gives 'chemical snapshot' of the effects of exercise

Thu, 27 May 2010 03:41:12 PDT

Using a system that analyzes blood samples with unprecedented detail, a team led by Massachusetts General Hospital (MGH) researchers has developed the first "chemical snapshot" of the metabolic effects of exercise. Their findings, reported in the May 26 issue of Science Translational Medicine, may improve understanding of the physiologic effects of exercise and lead to new treatments for cardiovascular disease and diabetes. "We found new metabolic signatures that clearly distinguish more-fit from less-fit individuals during exercise," says Gregory Lewis, MD, of the MGH Heart Center, the paper's lead author. "These results have implications for the development of optimal training programs and improved assessment of cardiovascular fitness, as well as for the development of nutritional supplements to enhance exercise performance." The beneficial health effects of exercise – including reducing the risk of heart disease, stroke and type 2 diabetes – are well known, but the biological mechanisms underlying those effects are unclear. Previous investigations of exercise-induced changes in metabolites – biological molecules produced in often-minute quantities – have focused on the few molecules measured by most hospital laboratories. Using a new mass-spectrometry-based system that profiles more than 200 metabolites at a time – developed in collaboration with colleagues from the Broad Institute of Harvard and MIT, led by Clary Clish, PhD – the MGH-based team analyzed blood samples taken from healthy participants before, immediately following, and one hour after exercise stress tests that were approximately 10 minutes long. Exercise-associated changes were seen in more than 20 metabolites, reflecting processing of sugars, fats and amino acids as fuels as well as the body's utilization of ATP, the primary source of cellular energy. Several changes involved metabolic pathways not previously associated with exercise, including increases in niacinamide, a vitamin derivative known to enhance insulin release. Another experiment that analyzed samples taken from different vascular locations indicated that most metabolite changes were generated in the exercising muscles, although some appeared to arise throughout the body. In both experiments, several metabolite changes persisted 60 minutes after exercise had ceased. In an experiment designed to assess the effects of prolonged exercise, pre- and post-race samples were taken from 25 runners who completed the 2006 Boston Marathon. Extensive changes in several metabolites – some different from those produced by brief exercise – were seen in the post-race samples. Indicators of increased metabolism of fats, glucose and other carbohydrates rose in response to both brief and prolonged exercise, but in marathoners amino acid levels also fell significantly, reflecting their use of amino acids as fuel to maintain adequate glucose levels during extended exercise. The researchers also analyzed how these metabolite changes related to participants' level of fitness – determined by peak oxygen uptake in the short-term experiments and by finishing times for the marathon runners. In both groups they found that several changes, including those reflecting increased fat metabolism, were more pronounced in participants who were more fit. Pursuing the hypothesis that metabolites which increase in response to exercise act on pathways involved in cellular respiration and glucose utilization, the investigators applied different combinations of metabolites to cultured muscle cells. They found that a combination of five molecules increased expression of nur77, a gene recently shown to regulate glucose levels and lipid metabolism, making it a possible treatment target for the combination of cardiovascular risk factors known as metabolic syndrome. The association of nur77 levels with exercise was supported by an experiment that found gene expression increased fivefold in the muscles of mice that had exercised for 30 minutes. "Our results have implications for development of both diagnostic testing to track and improve exercise performance and for interventions to reduce the effects of diabetes or heart disease by improving a patient's metabolic 'fingerprint'," explains Robert Gerszten, MD, director of Clinical and Translational Research at the MGH Heart Center, the study's senior author. "Improving the health of people with cardiovascular disease is our number one goal, but defining which metabolites become deficient and need to be replenished during exercise could also lead to the next generation of sports drinks that can help healthy individuals achieve their best exercise performance."

Caltech-led team first to directly measure body temperatures of extinct vertebrates

Tue, 25 May 2010 03:54:46 PDT

Was Tyrannosaurus rex cold-blooded? Did birds regulate their body temperatures before or after they began to grow feathers? Why would evolution favor warm-bloodedness when it has such a high energy cost? Questions like these—about when, why, and how vertebrates stopped relying on external factors to regulate their body temperatures and began heating themselves internally—have long intrigued scientists. Now, a team led by researchers at the California Institute of Technology (Caltech) has taken a critical step toward providing some answers. Reporting online this week in the early edition of the Proceedings of the National Academy of Sciences (PNAS), they describe the first method for the direct measurement of the body temperatures of large extinct vertebrates—through the analysis of rare isotopes in the animals' bones, teeth, and eggshells. "This is not quite like going back in time and sticking a thermometer up a creature's back end," says John Eiler, Robert P. Sharp Professor of Geology and professor of geochemistry at Caltech. "But it's close." Studying the mechanisms of and changes in temperature regulation in long-extinct animals requires knowing what their body temperatures were in the first place. But the only way scientists have had to study temperature regulation in such creatures was to make inferences based on what is known about their anatomy, diet, or behavior. Until now. The technique the team has developed to measure body temperature in extinct vertebrates looks at the concentrations of two rare isotopes—carbon-13 and oxygen-18. "These heavy isotopes like to bond, or clump together, and this clumping effect is dependent on temperature," says Caltech postdoctoral scholar Robert Eagle, the paper's first author. "At very hot temperatures, you get a more random distribution of these isotopes, less clumping. At low temperatures, you find more clumping." In living creatures, this clumping can be seen in the crystalline lattice that makes up bioapatite—the mineral from which bone, tooth enamel, eggshells, and other hard body parts are formed. "When the mineral precipitates out of the blood—when you create bone or tooth enamel—the isotopic composition is frozen in place and can be preserved for millions of years," he adds. In addition, work in Eiler's lab has "defined the relationship between clumping and temperature," says Eagle, "allowing measurements of isotopes in the lab to be converted into body temperature." The method is accurate to within one or two degrees of difference. "A big part of this paper is an exploration of what sorts of materials preserve temperature information, and where," notes Eiler. To do this, the team looked at bioapatite from animals whose form of body-temperature regulation is already known. "We know, for instance, that mammals are warm-blooded; all the bioapatite in their bodies was formed at or near 37 degrees centigrade," says Eagle. After showing proof of concept in living animals, the team looked at those no longer roaming the earth. For instance, the team was able to analyze mammoth teeth, finding body temperatures of between 37 and 38 degrees—exactly as expected. Going back even further in time, they looked at 12-million-year-old fossils from a relative of the rhinoceros, as well as from a cold-blooded member of the alligator family tree. "We found we could measure the expected body temperature of the rhino-like mammal, and could see a temperature difference between that and the alligator relative, of about 6 degrees centigrade," Eagle says. There are, however, limitations to this sort of temperature sleuthing. For one, the information that the technique provides is only a snapshot of a particular time and place, Eiler says, and not a lifelong record. "When we look at tooth enamel, for instance, what we get is a record of the head temperature of the animal when the tooth grew," he notes. "If you want to know what his big-toe temperature was two years later, too bad." And, of course, the technique relies on the quality of the fossils available for testing. While teeth tend to withstand the rigors of burial and time, eggshells are "fragile and prone to recrystallization during burial," says Eiler. Finding good specimens can be difficult. But the rewards are worth the effort. "The main reason to do this sort of work is because gigantic land animals are intrinsically fascinating," Eiler says. "We want to look at where warm-bloodedness emerged, and where it didn't emerge. And this technique will help us to reconstruct food webs. In the distant past, dinosaurs and other large animals were the crown of the food web; we'll be able to figure out how they went about their business." Now that they've pinned down an accurate paleothermometer, the research team has gone further back in time, and has begun looking at the body temperatures of vertebrates about whom less is known. "Before mammals and birds," says Eagle, "we have no good idea what physiology these ancient creatures had." First up? Dinosaurs, of course. "We're looking at eggshells and teeth to see whether the most conspicuous dinosaur species were warm- or cold-blooded," says Eiler. In addition, he says, the researchers would like to apply their approach to better understand some key evolutionary transitions. "Take birds, for instance," Eiler says. "Were they warm-blooded before or after they started to fly? Before or after they developed feathers? We want to take small birds and track their body temperature through time to see what we can learn." Finally, they hope to get a peek at the paleoclimate, through the body-temperature data derived from ancient cold-blooded animals. "With this method, we can track changes in body temperature as a proxy for changes in air or water temperature."

Systems biology helps to understand hematopoiesis

Sat, 22 May 2010 06:13:24 PDT

Our body reacts to blood loss by stimulating the production of red blood cells (erythrocytes). The cells of the hematopoietic (blood-forming) system in the bone marrow do so upon receipt of a signal by a hormone called erythropoietin, or Epo for short. This hormone is produced mainly by the kidney that increases the Epo level by up to a thousand-fold as a response to falling oxygen saturation of the blood. The hematopoietic cells receive the Epo signal through Epo receptors on their surface. How do the blood progenitor cells that carry only few receptor molecules manage to react adequately to a high rise in the Epo level and to always provide the required amount of red blood cells? "If too much of the hormone floods too few receptor molecules, we would expect the saturation point to be reached soon. This would mean that the hematopoietic cell can no longer respond to a further increase in the hormone level," says Dr. Ursula Klingmüller of DKFZ.......> Full story

How microtubules let go of their attachments during cell division

Fri, 14 May 2010 04:15:15 PDT

Whitehead Institute researchers have determined a key part of how cells regulate the chromosome/microtubule interface, which is central to proper chromosomal distribution during cell division. "This is the surveillance machinery that makes sure that the chromosomes are divided correctly between cells," says Whitehead Member Iain Cheeseman. The findings are published in this week's issue of Molecular Cell. During cell division, the cell's DNA is consolidated into X-shaped chromosome pairs that align along the middle of the cell. Where the arms of the X cross, each chromosome has two kinetochores--protein complexes that facilitate microtubule attachment to the chromosome. As cell division progresses, these microtubules pull the right or left half of each chromosome towards the spindle poles to separate them to opposite ends of the cell. Problems can frequently arise during this process. As a microtubule extends from a spindle pole, it may attach incorrectly to a kinetochore. When this happens, the cell needs a way to detect the mistake, detach the problematic microtubule, and reattach it correctly. If the issue is not addressed and cell division proceeds, the chromosomes typically fail to divide evenly, resulting in cells with the wrong number of chromosomes. This aberrant distribution of chromosomes can lead to cancer or premature cell death........> Full story

Unique close-up of the dynamics of photosynthesis

Tue, 11 May 2010 04:02:21 PDT

Researchers at the University of Gothenburg, Sweden, have managed, with the help of an advanced X-ray flash, to photograph the movement of atoms during photosynthesis – an achievement that has been recognised by the journal Science. The European Synchrotron Radiation Facility in Grenoble is home to one of the world's most advanced particle accelerators, whose pulsing X-ray beams are used by researchers to photograph and study life's tiniest components: atoms, molecules and proteins. Using the special X-ray camera, researchers can depict the position of atoms in a molecule and obtain a three-dimensional image of something that is smaller than a billionth of a metre. Researchers at the Department of Chemistry at the University of Gothenburg and at Chalmers University of Technology have now used this advanced technology to photograph the dynamics of life's most fundamental system: photosynthesis. The focus of the study was a protein which is central to the conversion of light to chemical energy during photosynthesis, and which process the Gothenburg researchers have been the first to (successfully photograph) (capture?). The X-ray image shows how the protein temporarily stores the light energy immediately before a chemical bond forms – a movement that takes place on a scale of less than a nanometre. The photograph is not only a fascinating snapshot of the very core of life, but could also be used in the solar panels of the future, where researchers hope to be able to imitate the sophisticated energy conversion of photosynthesis.

New technique permits development of enzyme tool kit

Tue, 11 May 2010 04:00:06 PDT

An Arizona State University graduate student, Jinglin Fu, in collaboration with Biodesign Institute researchers Neal Woodbury and Stephen Albert Johnston, has pioneered a technique that improves on scientists’ ability to harness and modulate enzyme activity.

The new approach, reported in the Journal of the American Chemical Society (published online on Apr. 21st, 2010) , could have wide applicability for designing a range of industrial catalysts, health care diagnostics and therapies centered on understanding the control of enzymatic activity.

Enzymes, key catalysts that speed up the reactions inside every cell, are critical for life. As Neal Woodbury, chief scientist the Biodesign Institute at Arizona State University notes, “all the processes that happen inside of your body, essentially without exception, are run by enzymes.” Enzymes are also a prized tool in biomedical research, aiding the development of diagnostic tests and therapeutics for a range of human diseases.

But studying the role of enzymes can be tricky. One approach has been to use a specialized platform known as a microarray—where glass slides are deposited with 10,000 protein fragments, called peptides, that are screened for their ability to react with specific enzymes and alter their activity. “On the microarray, you can screen thousands of molecules at the same time,” Fu says, allowing the simultaneous monitoring of the peptide-enzyme binding and the change in enzyme activity at each spot on the array.......> Full story

Study paves way for new biofuels models, technologies

Tue, 11 May 2010 03:25:08 PDT

Biofuels hold promise as environmentally friendly sources of renewable energy, but which ones should industry and policy leaders focus their efforts on developing? A new study involving researchers from North Carolina State University offers detailed insights into how biofuel chemicals react when burned. Their data and new computer models pave the way for development of new biofuels and technologies to maximize energy efficiency while minimizing environmental and human health risks. “Biofuels are a sensible choice as a renewable energy source, but of course there are complications,” says Dr. Phillip Westmoreland, a co-author of the study, professor of chemical and biomolecular engineering and director of the Institute for Computational Science and Engineering at NC State. “All of the biofuels have pros and cons, and you can’t manage or plan for use and risks unless you understand them enough.” The new paper helps define these risks by finding the network of chemical steps that take place when biofuels are burned. An invited overview for Angewandte Chemie, one of the world’s premier chemistry journals, the paper draws on landmark research conducted by Westmoreland and his co-authors from research institutions in the United States, Germany and China. “By studying individual chemicals that make up biofuels, we were able to explain what emissions result from burning real biofuels,” Westmoreland says. “We can measure the individual intermediates and chemical reactions, helping us craft models that reveal what chemicals are emitted, and in what amounts, by various biofuels. These models can be used to design new engines, new fuels and new policies that foster environmentally sustainable and efficient energy solutions. “This is important for regulation, where policy makers are weighing the environmental and health costs versus the energy benefits of different biofuels, but it is also essential to decision makers in the business community. Industry does not want to invest in developing biofuels and related technologies that can’t pass policy muster, and this research will help them make educated investment decisions.” The paper draws on information the researchers have collected about the chemicals produced when biofuels are burned, and how those chemicals change during the combustion process. These insights stem from the use of a novel experimental apparatus the researchers built at Lawrence Berkeley National Laboratory and a second system in Hefei, China – which provide unprecedented detail as to exactly what is happening at a molecular level when biofuels are burned. The paper, “Biofuel combustion chemistry: from ethanol to biodiesel,” is the featured cover article in the May 3 issue of Angewandte Chemie. The paper was co-authored by researchers from NC State, Bielefeld University in Germany, Cornell University, Sandia National Laboratories, the University of Science and Technology of China and Lawrence Livermore National Laboratory. The research was funded by the U.S. Department of Energy, the U.S. Army Research Office, and Deutsche Forschungsgemeinschaft, among others. NC State’s Department of Chemical and Biomolecular Engineering is part of the university’s College of Engineering.

Peptides may hold 'missing link' to life

Fri, 07 May 2010 04:33:40 PDT

Emory scientists have discovered that simple peptides can organize into bi-layer membranes. The finding suggests a “missing link” between the pre-biotic Earth’s chemical inventory and the organizational scaffolding essential to life. “We’ve shown that peptides can form the kind of membranes needed to create long-range order,” says chemistry graduate student Seth Childers, lead author of the paper recently published by the German Chemical Society’s Angewandte Chemie. “What’s also interesting is that these peptide membranes may have the potential to function in a complex way, like a protein.”

Chemistry graduate student Yan Liang captured images of the peptides as they aggregated into molten globular structures, and self-assembled into bi-layer membranes. The results of that experiment were recently published by the Journal of the American Chemical Society.

“In order to form nuclei, which become the templates for growth, the peptides first repel water,” says Liang, who is now an Emory post-doctoral fellow in neuroscience. “Once the peptides form the template, we can now see how they assemble from the outer edges."........> Full story

Biologists discover an extra layer of protection for bacterial spores

Fri, 07 May 2010 04:15:31 PDT

Bacterial spores, the most resistant organisms on earth, carry an extra coating of protection previously undetected, a team of microbiologists reports in the latest issue of the journal Current Biology. Their findings offer additional insight into why spores of the bacteria that cause botulism, tetanus, and anthrax survive methods to eradicate them. The study was conducted by researchers at New York University's Center for Genomics and Systems Biology, Loyola (Ill.) University's Medical Center, and Princeton University's Department of Molecular Biology. The researchers studied the spores of a non-pathogenic bacterium, Bacillus subtilis, which is commonly found in soil. Although non-pathogenic, B. subtilis spores exhibit many of the same structural features of the spore-forming pathogens. In this study, the scientists examined the proteins that comprise spores' protective layers. Previous research has shown that 70 different proteins make up these layers. Less understood is how these proteins interact to form the spores' protective coats. To do this, the researchers examined coat formation of both normal and mutant spores. In the latter case, they removed genes for selected coat proteins, allowing them to determine which proteins were necessary in—and extraneous to—the formation of the spores' coats. To observe proteins' behavior in living cells, the researchers fused the genes encoding the spores' coat proteins to a marker, a Green Fluorescent Protein (GFP). This procedure allowed them to monitor how the proteins localized to form spores' protective coats. A combination of fluorescence microscopy experiments and high-resolution image analysis enabled the researchers to overcome a theoretical limitation of light microscopy, pinpoint the location of the spores' coat proteins with a high degree of precision, and build a map of the spore coat. These experiments suggested the existence of a new outermost layer of the spore coat. They were then able to confirm the existence of this new layer using electron microscopy. The researchers named this coat layer, located on the spores' outer surface, the "spore crust." While it has not yet been confirmed, it is possible that the spore crust is a common feature of all spore-forming bacteria, such as the botulism, tetanus, and anthrax pathogens.

UCLA researchers show how world's smallest 'coffee ring' may help biosensors detect disease

Thu, 06 May 2010 03:54:06 PDT

The field of biosensing has recently found an unlikely partner in the quest for increased sensitivity: coffee rings. The next time you spill your coffee on a table, look at the spot left after the liquid has evaporated, and you'll notice it has a darker ring around its perimeter that contains a much higher concentration of particles than the center. Because this "coffee ring" phenomenon occurs with many liquids after they have evaporated, scientists have suggested that such rings can be used for examining blood or other fluids for disease markers by using biosensing devices. But a better understanding of how these rings behave at the micro- and nano-scale would probably be needed for practical bionsensors. "Understanding micro- and nano-particle transportation within evaporating liquid droplets has great potential for several technological applications, including nanostructure self-assembly, lithography patterning, particle coating, and biomolecule concentration and separation," said Chih-Ming Ho, the Ben Rich–Lockheed Martin Professor at the UCLA Henry Samueli School of Engineering and Applied Science and director of the UCLA Center for Cell Control. "However, before we can engineer biosensing devices to do these applications, we need to know the definitive limits of this phenomenon. So our research turned to physical chemistry to find the lowest limits of coffee-ring formation." A research group led by Ho, a member of the National Academy of Engineering, has now found the definitive microscopic minimal threshold of coffee-ring formation, which can be used to set standards for biosensor devices for multiple disease detection, as well as other uses. The research appears in the current issue of the Journal of Physical Chemistry B and is available online. "If we consider human blood, or saliva, it has a lot of micro- and nano-scale molecules or particles that carry important health information," said Tak-Sing Wong, one of the researchers and a postdoctoral scholar in UCLA Engineering's department of mechanical and aerospace engineering. "If you put this blood or saliva on a surface, and then it dries, these particles will be collected in a very small region in the ring. By doing so, we can quantify these biomarkers by various sensing techniques, even if they are very small and in a small amount in the droplets." As water evaporates from a droplet, particles that are suspended inside the liquid move to the droplet's edges. Once all the water has evaporated, the particles are concentrated in a ring around the stain that is left behind. However, if a droplet is small enough, the water will evaporate faster than the particles move. Rather than a ring, there will be a relatively uniform concentration in the stain, as the particles have not had enough time to move to the edges while still in the liquid. "It is the competition between the timescale of the evaporation of the droplet and the timescale of the movement of the particles that dictates coffee-ring formation," said Xiaoying Shen, the paper's lead author and a senior microelectronics major at Peking University in China, who worked on these experiments while at the UCLA Cross Disciplinary Scholars in Science and Technology (CSST) program last summer. To determine the smallest droplet size that would still show a coffee ring after evaporation, the research team manufactured a special surface coated in a checkerboard pattern that featured alternating hydrophilic, or water-loving, material and hydrophobic, or water-repelling, material. The group then placed latex particles, ranging in size from 100 nanometers to 20 nanometers, in water. The particles were similar in size to disease-marker proteins that biosensors would look for. The group washed the new surface with the particle-infused water. The remaining water lined up as droplets on the hydrophilic spots, much like checkers on a checkerboard. The group repeated the experiments with smaller grid patterns until the coffee-ring phenomenon was no longer evident. For the 100-nanometer sized particles, this occurred at a droplet diameter of approximately 10 micrometers, or about 10 times smaller than the width of a human hair. At this point, the water evaporated before the particles had enough time to move to the perimeter. "Knowing the minimum size of this so-called coffee ring will guide us in making the smallest biosensors possible," Wong said. "This means that we can pack thousands, even millions, of small micro-biosensors onto a lab-on-a-chip, allowing one to perform a large number of medical diagnostics on a single chip. This may also open the doors to potentially detecting multiple diseases in one sitting." "There's another important advantage — this whole process is very natural, it's just evaporation," Wong added. "We don't need to use additional devices, such as an electrical power source or other sophisticated instruments to move the particles. Evaporation provides a very simple way of concentrating particles and has potential in medical diagnosis. For example, researchers at Vanderbilt University were recently awarded a Gates Foundation Research Fund for proposing the use of the coffee-ring phenomenon for malaria detection in developing countries." The researchers are currently optimizing the ring formation parameters and will then explore the application of this approach toward biosensing technologies that are being developed in Ho's laboratory.

Caltech-led team uncovers new functions of mitochondrial fusion

Fri, 16 Apr 2010 03:54:48 PDT

A typical human cell contains hundreds of mitochondria—energy-producing organelles—that continually fuse and divide. Relatively little is known, however, about why mitochondria undergo this behavior. In a paper published in the April 16 issue of the journal Cell, a team of researchers—led by scientists at the California Institute of Technology (Caltech)—have taken steps toward a fuller understanding of this process by revealing just what happens to the organelle, its DNA (mtDNA), and its energy-producing ability when mitochondrial fusion fails. In the process, the researchers show that fusion (the merging of two mitochondria) is "highly protective, allowing the mitochondria to tolerate very high loads of mitochondrial DNA mutations," says David Chan, associate professor of biology at Caltech and a Howard Hughes Medical Institute (HHMI) investigator. These findings, Chan adds, help to shed light on the pathogenesis behind human mitochondrial encephalomyopathies—a class of neuromuscular diseases caused by mutations in mtDNA. In these diseases, muscle weakness occurs due to the loss of energy production by mitochondria........> Full story

The skinny on brown fat

Wed, 07 Apr 2010 04:05:37 PDT

Last year, researchers made a game-changing realization: brown fat, the energy-burning stuff that keeps babies warm, isn't just for the youngest among us. Adults have it, too (if they are lucky, anyway), and it is beginning to look like the heat-generating tissue might hold considerable metabolic importance for familiar and irritating trends, like our tendency to put on extra weight as we age. If we can find a way to hold onto, make more, or activate brown fat, it might be one way to help keep us slim, according to scientists who have written a series of minireviews appearing in a special April issue of Cell Metabolism, a Cell Press journal. "It's a new metabolic world; we can now ask questions we wouldn't have considered even one year ago," says Jan Nedergaard of Stockholm University, who authored one of the five reviews. Brown fat was once the preoccupation of a few researchers studying rodents and newborn mammals. "At times, their work was deemed more an exercise in scientific curiosity than an issue relevant to human health," write Cell Metabolism editors Nikla Emambokus and Charlotte Wang in an editorial. That all changed when three papers in the New England Journal of Medicine showed that adults have brown fat cells in their necks, where, as Sven Enerbäck of Göteborg University explains, it has the unique ability to safely dissipate chemical energy in the form of heat. When we spend a lot of time in the cold, the amount of brown fat we have goes up.......> Full story

These researchers really can read your mind

Fri, 12 Mar 2010 04:15:01 PDT

New evidence suggests that researchers can tell which memory of a past event a person is recalling from the pattern of their brain activity alone. The results, reported online on March 11th in Current Biology, a Cell Press publication, follow an earlier discovery by the same University College London team that they could tell where a person was standing within a virtual reality room in precisely the same way. The researchers say the new results move this line of research along because our episodic memories—those recollections of the everyday events that make up the autobiography of our lives—are expected to be more complex, and thus more difficult to crack, than your basic spatial memory would be........> Full story

Researchers Explain How Trauma Leads to Inflammatory Response

Thu, 04 Mar 2010 03:58:17 PDT

Inflammation is at the root of most serious complications occurring after both infection and injury. But while the molecular course of events that leads from microbial infections to the inflammatory condition called sepsis is fairly well understood, it is far less clear how and why physical injury can result in a similarly dangerous inflammatory response. Now a study led by investigators at Beth Israel Deaconess Medical Center (BIDMC) suggests that mitochondria – the body's cellular "power plants" -- are released into the bloodstream following physical injury. And because mitochondria closely resemble the bacteria from which they originated, they appear to elicit a sepsis-like immune response, changing from a vital source of cellular injury to a dangerous "enemy within."......> Full story

Antifreeze proteins can stop ice melt, new study finds

Tue, 02 Mar 2010 03:40:44 PDT

The same antifreeze proteins that keep organisms from freezing in cold environments also can prevent ice from melting at warmer temperatures, according to a new Ohio University and Queen's University study published today in the Early Edition of the journal Proceedings of the National Academy of Sciences. Antifreeze proteins are found in insects, fish, bacteria and other organisms that need to survive in cold temperatures. These proteins protect the organisms by arresting the growth of ice crystals in their bodies. The new study not only has implications for understanding this process in nature, but also for understanding the superheating of crystals in technologies that use superconductor materials and nanoparticles.......> Full story

A new spin on energy independence

Thu, 18 Feb 2010 03:59:47 PDT

In a world addicted to oil, the notion of a pill that could shift countries' dependence on oil to another form of energy seems far-fetched - and it is. But a similar idea, rooted in the biology of the human body, has gained traction in recent years. The goal: to find a drug that can coax cells to change the way they use their energy resources. In a paper appearing in the February 14 advance online issue of the journal Nature Biotechnology, a team of scientists reports the discovery of a well-known compound that seems to do just that. Their findings could someday spur new ways of preventing or treating a variety of illnesses, including stroke, heart attack and maybe even cancer.......> Full story

Minimal Changes Alter An Enzyme Dramatically

Wed, 20 Jan 2010 03:47:53 PDT

A new study by a research team at Uppsala University shows how new functions can develop in an enzyme. This can explain, for example, how resistance to toxins can occur so simply. The findings are now being published in the Journal of Biological Chemistry. Every biological being needs a large number of enzymes for the many functions of cells. In the spirit of Darwin, enzymes in an organism can change over time to meet new needs. This is done by alterations in the enzymes' building blocks that are caused by mutations in the DNA.......> Full story

Body's own veins are superior material for aortic grafts

Mon, 04 Jan 2010 03:53:50 PDT

A vascular surgical technique pioneered at UT Southwestern Medical Center and designed to replace infected aortic grafts with the body’s own veins has proved more durable and less prone to new infection than similar procedures using synthetic and cadaver grafts. Aortic graft infections are one of the most serious complications in patients undergoing aortic grafting procedures for peripheral arterial disease (PAD) and aortic aneurysms. PAD reduces blood circulation in the pelvis and lower extremities.......> Full story

Bioengineered Materials Promote The Growth Of Functional Vasculature, New Study Shows

Tue, 22 Dec 2009 04:02:45 PDT

Regenerative medicine therapies often require the growth of functional, stable blood vessels at the site of an injury. Using synthetic polymers called hydrogels, researchers at the Georgia Institute of Technology have been able to induce significant vasculature growth in areas of damaged tissue. "This study shows that bio-artificial materials are suitable for promoting vasculature growth and remodeling," said lead author on the study Andrés García, professor and Woodruff Faculty Fellow in Georgia Tech's Woodruff School of Mechanical Engineering and the Petit Institute for Bioengineering and Bioscience......> Full story

Research project yields better understanding of the defective protein that causes cystic fibrosis

Fri, 18 Dec 2009 04:20:08 PDT

A team of researchers studying the protein that, when defective or absent, causes cystic fibrosis (CF) has made an important discovery about how that protein is normally controlled and under what circumstances it might go awry."Understanding the regulation of salt transport in normal cells is critical for the development of new therapies for diseases, like CF, that disrupt salt movements across cell borders......> Full story

MDC researchers identify a scaffold regulating protein disposal

Sat, 12 Dec 2009 04:26:38 PDT

How does a cell manage to identify and degrade the diverse types of defective proteins and thus protect the body against serious diseases? The researchers Sabine C. Horn, Professor Thomas Sommer, Professor Udo Heinemann and Dr. Ernst Jarosch of the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch, Germany, have now found a crucial piece in this puzzle. In an enzyme complex that plays a critical role in the quality control of proteins, they discovered a scaffold regulating the identification.......> Full story

Early Protein Processes Crucial To Formation And Layering Of Myelin Membrane

Wed, 25 Nov 2009 04:14:11 PDT

New findings from an international team of researchers probing the nerve-insulating myelin sheath were bolstered by the work of Boston College biologists, who used x-rays to uncover how mutations affect the structure of myelin, a focal point of research in multiple sclerosis and other neurological disorders......> Full story

Computational Microscope Peers Into The Working Ribosome

Tue, 24 Nov 2009 06:46:22 PDT

Two new studies reveal in unprecedented detail how the ribosome interacts with other molecules to assemble new proteins and guide them toward their destination in biological cells. The studies used molecular dynamics flexible fitting (MDFF) to examine the interaction of the ribosome with two prominent molecular partners......> Full story

'Slimming Gene' Discovered That Regulates Body Fat

Sun, 22 Nov 2009 04:03:17 PDT

Scientists at the University of Bonn have discovered a previously unknown fruit fly gene that controls the metabolism of fat. Larvae in which this gene is defective lose their entire fat reserves. Therefore the researchers called the gene 'schlank' (German for 'slim'). Mammals carry a group of genes that are structurally very similar to 'schlank'. They possibly take on a similar function in the energy metabolism. The scientists therefore have hopes in new medicines with which obesity could be fought......> Full story

Flax and yellow flowers can produce bioethanol

Sat, 21 Nov 2009 04:06:01 PDT

Surplus biomass from the production of flax shives, and generated from Brassica carinata, a yellow-flowered plant related to those which engulf fields in spring, can be used to produce bioethanol. This has been suggested by two studies carried out by Spanish and Dutch researchers and published in the journal Renewable and Sustainable Energy Reviews......> Full story

Vibrations Key To Efficiency Of Green Fluorescent Protein

Thu, 12 Nov 2009 06:00:57 PDT

University of California, Berkeley, chemists have discovered the secret to the success of a jellyfish protein whose green glow has made it the darling of biologists and the subject of the 2008 Nobel Prize in Physiology or Medicine. The researchers' study of green fluorescent protein (GFP) and the structural changes it undergoes when it fluoresces is the cover story of the Nov. 12 issue of the journal Nature.......> full story

Wet ethanol production process yields more ethanol and more co-products

Tue, 10 Nov 2009 06:04:30 PDT

Using a wet ethanol production method that begins by soaking corn kernels rather than grinding them, results in more gallons of ethanol and more usable co-products, giving ethanol producers a bigger bang for their buck – by about 20 percent. "The conventional ethanol production method has fewer steps, but other than distillers dried grains with soluble, it doesn't have any other co-products," said University of Illinois Agricultural Engineer Esha Khullar. "Whereas in both wet and dry fractionation processes......> full story

New Technique For Specifying Location Of Sugars On Proteins Paves Way For Medical Discoveries

Sat, 07 Nov 2009 06:25:09 PDT

Researchers have previously been able to analyse which sugar structures are to be found on certain proteins, but not exactly where on the protein they are positioned. This is now possible thanks to a new technique developed at the Sahlgrenska Academy at the University of Gothenburg, Sweden. The technique entails preparing samples in a new way and is a development of applied mass spectrometry. Presented in the latest issue of renowned journal Nature Methods, the technique will enable medical researchers to study the mechanisms behind diseases in more detail and, with luck, find new ways of treating them......> full story

Standards for a New Genomic Era

Sat, 24 Oct 2009 05:50:36 PDT

A team of geneticists at Los Alamos National Laboratory, together with a consortium of international researchers, has recently proposed a set of standards designed to elucidate the quality of publicly available genetic sequencing information. The new standards could eventually allow genetic researchers to develop vaccines more efficiently or help public health or security personnel more quickly respond to potential public-health emergencies......> full story

Think What You Eat: Studies Point To Cellular Factors Linking Diet And Behavior

Thu, 22 Oct 2009 06:07:51 PDT

New research released today is affirming a long-held maxim: you are what you eat — and, more to the point, what you eat has a profound influence on the brain. The findings offer insight into the neurobiological factors behind the obesity epidemic in the United States and other developed countries. The findings exposed changes in brain chemistry due to diet and weight gain, and were reported at Neuroscience 2009, the Society for Neuroscience's annual meeting and the world's largest source of emerging news about brain science and health......> full story

Penn Team Uses Self-Assembly to Make Tiny Particles With Patches of Charge

Thu, 22 Oct 2009 06:01:16 PDT

Physicists, chemists and engineers at the University of Pennsylvania have demonstrated a novel method for the controlled formation of patchy particles, using charged, self-assembling molecules that may one day serve as drug-delivery vehicles to combat disease and perhaps be used in small batteries that store and release charge.Researchers demonstrated that the positive electrical charges of calcium ions — just like the calcium in teeth and bone — can form bridges between negatively charged polymers that would normally repel each other......> full story

'Spaghetti' Scaffolding Could Help Grow Skin In Labs

Mon, 19 Oct 2009 05:49:02 PDT

Scientists are developing new scaffolding technology which could be used to grow tissues such as skin, nerves and cartilage using 3D spaghetti-like structures. Their research is highlighted in the latest issue of Business, the quarterly highlights magazine of the Biotechnology and Biological Sciences Research Council (BBSRC). The new structures are being developed by scientists from the University of Bristol, using proteins from alpha helices......> full story

'Spaghetti' scaffolding could help grow skin in labs

Sun, 18 Oct 2009 06:30:17 PDT

Caltech Researchers Reveal Unexpected Sources of Nitrogen Fixation

Sun, 18 Oct 2009 06:12:22 PDT

Researchers at the California Institute of Technology (Caltech) have identified an unexpected metabolic ability within a symbiotic community of microorganisms that may help solve a lingering mystery about the world's nitrogen-cycling budget. A paper about their work appears in the October 16 issue of the journal Science. The element nitrogen is a critical part of amino acids, the building blocks of proteins, and therefore essential to all life. Although nitrogen is plentiful on Earth—it comprises 78 percent of the atmosphere, by volume—the element is usually found strongly bonded to itself, in the form of the diatomic gas N₂. To be biologically useful......> full story

Loss of Tumor-Suppressor and DNA-Maintenance Proteins Causes Tissue Demise, Penn Study Finds

Sat, 17 Oct 2009 05:47:52 PDT

A study published in the October issue of Nature Genetics demonstrates that loss of the tumor-suppressor protein p53, coupled with elimination of the DNA-maintenance protein ATR, severely disrupts tissue maintenance in mice. As a result, tissues deteriorate rapidly, which is generally fatal in these animals. In addition, the study provides supportive evidence for the use of inhibitors of ATR in cancer therapy. Related Image......> full story

Scientists visualize assembly line gears in ribosomes, cell's protein factory

Fri, 16 Oct 2009 06:25:38 PDT

Even as research on the ribosome, one of the cell's most basic machines, is recognized with a Nobel Prize, scientists continue to achieve new insights on the way ribosomes work. Ribosomes are factories inside cells where messages coming from genes are decoded and new proteins pieced together on an assembly line. For the first time, scientists have a detailed picture of the ribosome trapped together with elongation factor G (EF-G), one of the enzymes that nudges the assembly line to move forward.......> full story

Measure Total Antioxidant Status with Randox

Fri, 16 Oct 2009 05:42:14 PDT

Randox provide a total antioxidant status (TAS) kit to complement the wide range of antioxidant products thus enabling a complete profile of patient antioxidant status. The Randox kit is currently the only commercially available kit for TAS. Antioxidants help defend the body against free radicals – highly reactive molecules that have been implicated in the development of over 100 diseases affecting all major organs in the body. Many diseases have been associated with low antioxidant levels.......> full story

Cell Death Occurs In Same Way In Plants And Animals

Thu, 15 Oct 2009 06:16:26 PDT

Research has previously assumed that animals and plants developed different genetic programs for cell death. Now an international collaboration of research teams, including one at the Swedish University of Agricultural Sciences, has shown that parts of the genetic programs that determine programmed cell death in plants and animals are actually evolutionarily related and moreover function in a similar way......> full story

Nanometric Butterfly Wings Created

Mon, 12 Oct 2009 06:00:06 PDT

A team of researchers from the State University of Pennsylvania (USA) and the Universidad Autónoma de Madrid (UAM) has developed a technique to replicate biological structures, such as butterfly wings, on a nano scale. The resulting biomaterial could be used to make optically active structures, such as optical diffusers for solar panels.Insects' colours and their iridescence (the ability to change colours depending on the angle) or their ability to appear metallic are determined by tiny nano-sized photonic structures (1 nanometre = 10^-9 m) which can be found in their cuticle. Scientists have focused on these biostructures to develop devices with light emitting properties that they have just presented in the journal Bioinspiration & Biomimetics......> full story

Prion Study Reveals First Direct Information About the Protein’s Molecular Structure

Thu, 08 Oct 2009 05:58:38 PDT

A collaboration between scientists at Vanderbilt University and the University of California, San Francisco has led to the first direct information about the molecular structure of prions. In addition, the study has revealed surprisingly large structural differences between natural prions and the closest synthetic analogs that scientists have created in the lab........> full story

Is 'Stem Cell' Concept Holding Back Biology?

Sat, 03 Oct 2009 06:14:15 PDT

Before it was learned that matter burns by taking up oxygen, most chemists sought to explain combustion as the release of a mysterious substance, which they named "phlogiston". Phlogiston theory was a conceptual breakthrough that helped chemists conduct experiments and share ideas. Only when it came to pinning down the distinctive physical properties of phlogiston did it become clear that no such thing exists......> full story

Light, Photosynthesis Help Bacteria Invade Fresh Produce

Wed, 30 Sep 2009 06:10:45 PDT

Exposure to light and possibly photosynthesis itself could be helping disease-causing bacteria to be internalized by lettuce leaves, making them impervious to washing, according to research published in the October issue of the journal Applied and Environmental Microbiology......> full story

How Mitochondrial Gene Defects Impair Respiration, Other Major Life Functions

Fri, 25 Sep 2009 06:01:50 PDT

Researchers are delving into abnormal gene function in mitochondria, structures within cells that power our lives. Mitochondria are the place where energy is generated from the most basic molecules of food. Because this function is essential to life, defects in mitochondria may affect a wide range of organ systems in humans and animals.......> full story

How proteins talk to each other

Tue, 22 Sep 2009 06:33:56 PDT

Investigators at Burnham Institute for Medical Research (Burnham) have identified novel cleavage sites for the enzyme caspase-3 (an enzyme that proteolytically cleaves target proteins). Using an advanced proteomic technique called N-terminomics, Guy Salvesen, Ph.D., professor and director of the Apoptosis and Cell Death Research program of Burnham’s NCI-designated Cancer Center, and colleagues determined the cleavage sites on target proteins and found, contrary to previous understanding, that caspase-3 targets α-helices as well as unstructured loops. In addition, researchers found that caspase-3 and the substrates it binds to co-evolved. The paper......> full story

Researcher Discover Way to Make More Efficient Microbial Fuel Cells

Mon, 07 Sep 2009 05:46:29 PDT

Bacteria that generate significant amounts of electricity could be used in microbial fuel cells to provide power in remote environments or to convert waste to electricity. Professor Derek Lovley from the University of Massachusetts, USA isolated bacteria with large numbers of tiny projections called pili which were more efficient at transferring electrons to generate power in fuel cells than bacteria with a smooth surface......> full story