Mammary gland development of blueberry-fed lab animals studied

U.S. Department of Agriculture (USDA)-funded studies of mammary gland development in laboratory rats fed blueberries or other foods of interest may aid breast cancer research.

In an early study that has paved the way to follow-up experiments, Rosalia C. M. Simmen of the Arkansas Children's Nutrition Center (ACNC) in Little Rock, Ark., has determined that several indicators of rat mammary gland health were improved in the offspring (pups) of mothers (dams) that had been fed 5 percent blueberry powder in their rations during pregnancy and during the weeks that they nursed their pups.

The powder comprised 5 percent of the total weight of the feed, according to Simmen, a senior investigator at the center and a professor at the University of Arkansas for Medical Sciences in Little Rock.

The ACNC is a partnership between the USDA's Agricultural Research Service (ARS), Arkansas Children's Hospital in Little Rock, and the university.

The effects noted in the blueberry study have not been shown in humans and have not yet been traced to a particular blueberry compound, Simmen noted.

Her team evaluated several structural indicators of normal mammary gland development in the lab animals, including branching of the gland. There was significantly more branching in the offspring of the group that consumed the diet containing 5 percent blueberry powder than in offspring of dams fed rations containing 2.5 percent or 10 percent blueberry powder, Simmen reported.

Branching occurs when cells specialize or differentiate. Differentiation is generally preferable to rapid proliferation of undifferentiated cells, which can be a risk factor for breast cancer.

In their analysis of several biochemical indicators, the team found, for instance, that the level of the tumor-suppressing protein PTEN (phosphatase and tensin homolog deleted in chromosome 10) was significantly higher in mammary tissues of offspring of dams on the 5 percent regimen. That's a plus, because PTEN is thought to help protect against cancer.

Lab animal studies of blueberries' potential role in preventing breast cancer date to 2006. But Simmen's investigation, published in Nutrition Research in 2009, provided the first evidence from a lab animal study of the early influence that the mother's blueberry consumption can have on normal, healthy development of the mammary gland in her offspring.

More information: Read more about these experiments in the May/June 2011 issue of Agricultural Research magazine: http://www.ars.usd … ruit0511.htm

Provided by United States Department of Agriculture

Lasers used to form 3-D crystals made of nanoparticles

ScienceDaily (June 3, 2011) — University of Michigan physicists used the electric fields generated by intersecting laser beams to trap and manipulate thousands of microscopic plastic spheres, thereby creating 3-D arrays of optically induced crystals.

The technique could someday be used to analyze the structure of materials of biological interest, including bacteria, viruses and proteins, said U-M physicist Georg Raithel.

Raithel is co-author of a research paper on the topic published online May 31 in the journal Physical Review E. The other author is U-M research fellow Betty Slama-Eliau.

The standard method used to characterize biological molecules like proteins involves crystallizing them, then analyzing their structure by bombarding the crystals with X-rays, a technique called X-ray crystallography. But the method cannot be used on many of the proteins of highest interest -- such as cell-membrane proteins -- because there's no way to crystallize those molecules.

"So we came up with this idea that one could use, instead of a conventional crystal, an optically induced crystal in order to get the crystallization of a sample that could be suitable for structural analysis," said Raithel, professor of physics and associate chair of the department.

To move toward that goal, Raithel and his colleagues are developing the laser technique using microscopically small plastic spheres instead of the molecules. Other researchers have created 3-D optically induced crystals, but Raithel said the crystals his team created are denser than those previously achieved.

The process involves shining laser beams through two opposed microscope lenses, one directly beneath the other. Two infrared laser beams are directed through each lens, and they meet at a common focal point on a microscope slide that holds thousands of plastic nanoparticles suspended in a drop of water.

The intersecting laser beams create electric fields that vary in strength in a regular pattern that forms a 3-D grid called an optical lattice. The nanoparticles get sucked into regions of high electric-field strength, and thousands of them align to form optically induced crystals. The crystals are spherical in shape and about 5 microns in diameter. A micron is one millionth of a meter.

Imagine an egg crate containing hundreds of eggs. The cardboard structure of the crate is the optical lattice, and each of the eggs represents one of the nanoparticles. Stack several crates on top of each other and you get a 3-D crystal structure.

"The crate is the equivalent of the optical lattice that the laser beams make," Raithel said. "The structure of the crystal is determined by the egg carton, not by the eggs."

The optical crystals dissipate as soon as the laser is switched off.

The research was funded by the National Science Foundation.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Michigan.

Journal Reference:

B. Slama-Eliau, G. Raithel. Three-dimensional arrays of submicron particles generated by a four-beam optical lattice. Physical Review E, 2011; 83 (5) DOI: 10.1103/PhysRevE.83.051406

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Researchers discover biochemical weakness of malaria parasite -- vaccine to be developed

Every year, 10,000 pregnant women and up to 200,000 newborn babies are killed by the malaria parasite. Doctors all around the globe have for years been looking in vain for a medical protection, and now researchers from the University of Copenhagen have found the biochemically weakness of the lethal malaria parasite, and will now start developing a vaccine to combat pregnancy related malaria.

The malaria parasite travels via the spit of an infected mosquito to the liver of the new host, where it spreads to the red blood corpuscles and starts to reproduce itself.

"Pregnant women and children below the age of five years are particularly vulnerable to malaria because of the parasite's survival mechanisms. The parasite has a protein hook designed to attach it to the placenta and this leads to amnesia of the mother who in worst case can die or deliver prematurely. This increases the maternal mortality - and infant mortality," explains Associate Professor Ali Salanti from the University of Copenhagen's Centre for Medical Parasitology who manages the project.

The body's immune system normally attacks any foreign body but since our spleen constantly filters our blood and removes ruined or deform blood cells, the body's natural defense does not need to check the blood. And the malaria parasite exploits this fact.

An infected red blood corpuscle is more stiff than in its normal state and this would usually trigger the spleen to destroy the cell and parasite, but the malaria parasite has an advanced arsenal of protein hooks. With these hooks the parasite attaches itself to the inner side of the blood vessel and even if our immune system succeeds in defeating one hook, the parasite has 60 different hooks, which again differ from one malaria parasite to another.

Researchers have for years been looking for a vaccine which can attack the malaria parasite's specific placenta hook. This is tricky not least due to the fact that the parasite's hooks are long proteins which are difficult to produce artificially in the lab when developing of a vaccine.

After intensive research efforts, the researchers have now succeeded in identifying a fragment of the placenta hook (VAR2CSA) which not only is crucial for the parasite's ability to attach itself to the placenta, but also is possible to produce artificially for a vaccine.

"A vaccine must stimulate the immune system to quickly attack something foreign in the body. Therefore, it was a matter of finding the part of the placenta hook, which the parasite cannot manage without and which we could target a vaccine against," says Associate Professor Ali Salanti.

With a grant of 15 million DKK (approximately 3 million USD) from the Danish National Advanced Technology Foundation and close corporation with two Danish biotech companies, the researchers can now start developing the vaccine and take it through the first trials to test its safety.

Ali Salanti and his colleagues will collaborate with the biotech companies ExpreS2ion Biotechnologies and CMC Biologics A/S to develop a method for mass production of the vaccine.

Once this has fallen into place, the researchers can start up the clinical trials on animals and human beings. If the trials are successful the parasistologists from the University of Copenhagen and their partners will make a significant contribution in reaching the UN's Millennium Development goal number 4 and 5. These two goals encourage every country in the world to work on lowering global child mortality with two thirds and maternal mortality with three quarters.

Provided by University of Copenhagen

Compaction bands in sandstone are permeable: Findings could aid hydraulic fracturing, other fluid extraction techniques

When geologists survey an area of land for the potential that gas or petroleum deposits could exist there, they must take into account the composition of rocks that lie below the surface. Take, for instance, sandstone -- a sedimentary rock composed mostly of weakly cemented quartz grains. Previous research had suggested that compaction bands -- highly compressed, narrow, flat layers within the sandstone -- are much less permeable than the host rock and might act as barriers to the flow of oil or gas.

Now, researchers led by José Andrade, associate professor of civil and mechanical engineering at the California Institute of Technology (Caltech), have analyzed X-ray images of Aztec sandstone and revealed that compaction bands are actually more permeable than earlier models indicated. While they do appear to be less permeable than the surrounding host rock, they do not appear to block the flow of fluids. Their findings were reported in the May 17 issue of Geophysical Research Letters.

The study includes the first observations and calculations that show fluids have the ability to flow in sandstone that has compaction bands. Prior to this study, there had been inferences of how permeable these formations were, but those inferences were made from 2D images. This paper provides the first permeability calculations based on actual rock samples taken directly from the field in the Valley of Fire, Nevada. From the data they collected, the researchers concluded that these formations are not as impermeable as previously believed, and that therefore their ability to trap fluids -- like oil, gas, and CO2 -- should be measured based on 3D images taken from the field.

"These results are very important for the development of new technologies such as CO2 sequestration -- removing CO2 from the atmosphere and depositing it in an underground reservoir -- and hydraulic fracturing of rocks for natural gas extraction," says Andrade. "The quantitative connection between the microstructure of the rock and the rock's macroscopic properties, such as hydraulic conductivity, is crucial, as physical processes are controlled by pore-scale features in porous materials. This work is at the forefront of making this quantitative connection."

The research team connected the rocks' 3D micromechanical features -- such as grain size distribution, which was obtained using microcomputed tomography images of the rocks to build a 3D model -- with quantitative macroscopic flow properties in rocks from the field, which they measured on many different scales. Those measurements were the first ever to look at the three-dimensional ability of compaction bands to transmit fluid. The researchers say the combination of these advanced imaging technologies and multiscale computational models will lead to unprecedentedly accurate measurements of crucial physical properties, such as permeability, in rocks and similar materials.

Andrade says the team wants to expand these findings and techniques. "An immediate idea involves the coupling of solid deformation and chemistry," he says. "Accounting for the effect of pressures and their potential to exacerbate chemical reactions between fluids and the solid matrix in porous materials, such as compaction bands, remains a fundamental problem with multiple applications ranging from hydraulic fracturing for geothermal energy and natural gas extraction, to applications in biological tissue for modeling important processes such as osteoporosis. For instance, chemical reactions take place as part of the process utilized in fracturing rocks to enhance the extraction of natural gas."

Other coauthors of the paper, "Connecting microstructural attributes and permeability from 3D tomographic images of in situ shear-enhanced compaction bands using multiscale computations," are WaiChing Sun, visiting scholar at Caltech; John Rudnicki, professor of civil and environmental engineering at Northwestern University; and Peter Eichhubl, research scientist in the Bureau of Economic Geology at the University of Texas at Austin.

The work was partially funded by the Geoscience Research Program of the U.S. Department of Energy.

Story Source:

The above story is reprinted (with editorial adaptations) from materials provided by California Institute of Technology. The original article was written by Katie Neith.

Journal Reference:

WaiChing Sun, José E. Andrade, John W. Rudnicki, Peter Eichhubl. Connecting microstructural attributes and permeability from 3D tomographic images of in situ shear-enhanced compaction bands using multiscale computations. Geophysical Research Letters, 2011; 38 (10) DOI: 10.1029/2011GL047683

Stamping out low cost nanodevices

A simple technique for stamping patterns invisible to the human eye onto a special class of nanomaterials provides a new, cost-effective way to produce novel devices in areas ranging from drug delivery to solar cells.

The technique was developed by Vanderbilt University engineers and described in the cover article of the May issue of the journal Nano Letters.

The new method works with materials that are riddled with tiny voids that give them unique optical, electrical, chemical and mechanical properties. Imagine a stiff, sponge-like material filled with holes that are too small to see without a special microscope.

For a number of years, scientists have been investigating the use of these materials -- called porous nanomaterials -- for a wide range of applications including drug delivery, chemical and biological sensors, solar cells and battery electrodes. There are nanoporous forms of gold, silicon, alumina, and titanium oxide, among others.

Simple stamping

A major obstacle to using the materials has been the complexity and expense of the processing required to make them into devices.

Now, Associate Professor of Electrical Engineering Sharon M. Weiss and her colleagues have developed a rapid, low-cost imprinting process that can stamp out a variety of nanodevices from these intriguing materials.

"It's amazing how easy it is. We made our first imprint using a regular tabletop vise," Weiss said. "And the resolution is surprisingly good."

The traditional strategies used for making devices out of nanoporous materials are based on the process used to make computer chips. This must be done in a special clean room and involves painting the surface with a special material called a resist, exposing it to ultraviolet light or scanning the surface with an electron beam to create the desired pattern and then applying a series of chemical treatments to either engrave the surface or lay down new material. The more complicated the pattern, the longer it takes to make.

About two years ago, Weiss got the idea of creating pre-mastered stamps using the complex process and then using the stamps to create the devices. Weiss calls the new approach direct imprinting of porous substrates (DIPS). DIPS can create a device in less than a minute, regardless of its complexity. So far, her group reports that it has used master stamps more than 20 times without any signs of deterioration.

Process can produce nanoscale patterns

The smallest pattern that Weiss and her colleagues have made to date has features of only a few tens of nanometers, which is about the size of a single fatty acid molecule. They have also succeeded in imprinting the smallest pattern yet reported in nanoporous gold, one with 70-nanometer features.

The first device the group made is a "diffraction-based" biosensor that can be configured to identify a variety of different organic molecules, including DNA, proteins and viruses. The device consists of a grating made from porous silicon treated so that a target molecule will stick to it. The sensor is exposed to a liquid that may contain the target molecule and then is rinsed off. If the target was present, then some of the molecules stick in the grating and alter the pattern of reflected light produced when the grating is illuminated with a laser.

According to the researchers' analysis, when such a biosensor is made from nanoporous silicon it is more sensitive than those made from ordinary silicon.

The Weiss group collaborated with colleagues in Chemical and Biomolecular Engineering to use the new technique to make nano-patterned chemical sensors that are ten times more sensitive than another type of commercial chemical sensor called Klarite that is the basis of a multimillion-dollar market.

The researchers have also demonstrated that they can use the stamps to make precisely shaped microparticles by a process called "over-stamping" that essentially cuts through the nanoporous layer to free the particles from the substrate. One possible application for microparticles made this way from nanoporous silicon are as anodes in lithium-ion batteries, which could significantly increase their capacity without adding a lot of weight.

Vanderbilt University has applied for a patent on the DIPS method.

Vanderbilt graduate student Judson D. Ryckman, Marco Liscidini, University of Pavia and John E. Sipe, University of Toronto, contributed to the research, which was supported by grants from the U.S. Army Research Office, INNESCO project, The National Sciences and Engineering Research Council of Canada and a Graduate Research Fellowship from the National Science Foundation.

Story Source:

The above story is reprinted (with editorial adaptations ) from materials provided by Vanderbilt University. The original article was written by David Salisbury.

Journal Reference:

Judson D. Ryckman, Marco Liscidini, J. E. Sipe, S. M. Weiss. Direct Imprinting of Porous Substrates: A Rapid and Low-Cost Approach for Patterning Porous Nanomaterials. Nano Letters, 2011; 11 (5): 1857 DOI: 10.1021/nl1028073