New Treatments for Baldness? Scientists Find Stem Cells That Tell Hair It's Time to Grow

Researchers have discovered the source of signals that trigger hair growth, an insight that may lead to new treatments for baldness. (Credit: © Tasosk / Fotolia)

ScienceDaily — Yale researchers have discovered the source of signals that trigger hair growth, an insight that may lead to new treatments for baldness.

The researchers identified stem cells within the skin's fatty layer and showed that molecular signals from these cells were necessary to spur hair growth in mice, according to research published in the Sept. 2 issue of the journal Cell.

"If we can get these fat cells in the skin to talk to the dormant stem cells at the base of hair follicles, we might be able to get hair to grow again," said Valerie Horsley, assistant professor of molecular, cellular and developmental biology and senior author of the paper.

Men with male pattern baldness still have stem cells in follicle roots but these stem cells lose the ability to jump-start hair regeneration. Scientists have known that these follicle stem cells need signals from within the skin to grow hair, but the source of those signals has been unclear.

Horsley's team observed that when hair dies, the layer of fat in the scalp that comprises most of the skin's thickness shrinks. When hair growth begins, the fat layer expands in a process called adipogenesis. Researchers found that a type of stem cell involved in creation of new fat cells -- adipose precursor cells -- was required for hair regeneration in mice. They also found these cells produce molecules called PDGF (platelet derived growth factors), which are necessary to produce hair growth.

Horsley's lab is trying to identify other signals produced by adipose precursor stem cells that may play a role in regulating hair growth. She also wants to know whether these same signals are required for human hair growth. Other authors from Yale are lead author Eric Festa, Jackie Fretz, Ryan Berry, Barbara Schmidt, Matthew Rodeheffer and Mark Horowitz.

The work was funded by the National Institutes of Health and the Connecticut Stem Cell Research Program

Testing the water for bioenergy crops

Posted by Biomechanism

“Water significant limiting factor in growing crops like switchgrass.”

Energy researchers and environmental advocates are excited about the prospect of gaining more efficient large-scale biofuel production by using large grasses like miscanthus or switchgrass rather than corn.

They have investigated yields, land use, economics and more, but one key factor of agriculture has been overlooked: water.

Caption: Bioenergy crops such as switchgrass and miscanthus respond differently to rain, dew and sun Credit: Praveen Kumar

“While we are looking for solutions for energy through bioenergy crops, dependence on water gets ignored, and water can be a significant limiting factor,” said Praveen Kumar, an environmental engineer and atmospheric scientist at the University of Illinois at Urbana-Champaign.

“There are many countries around the world that are looking into biofuel energy, but if they are adopting these [large grasses] into their regular policy, they need to take into account the considerations for the associated demand for water.”

Kumar led a study, the results of which are published this week in the journal Proceedings of the National Academy of Sciences, detailing links between the hydrologic cycle and large-scale land conversion, both now and as growing conditions change in the future.

“To meet the growing energy needs of humanity-at-large in a sustainable manner, it’s important to understand the implications of switching to alternate energy options such as bioenergy,” said Anjuli Bamzai, program director in the National Science Foundation’s Division of Atmospheric and Geospace Sciences, which funded the research.

Miscanthus and switchgrass have a very different above-ground foliage structure from corn–more surface area and much denser growth.

This is good for maximizing the amount of biomass that an acre of land can produce, Kumar said, but it also increases water use.

Miscanthus and switchgrass intercept light and rain differently from corn and lose more water through transpiration, causing them to pull more water from the soil.

The result of large-scale adoption would be a reduction in soil moisture and runoff, but an increase in atmospheric humidity.

“All these together account for changes in hydrology, just from land-use change,” said Kumar. “Then, if you impose further–higher carbon dioxide in the atmosphere, higher temperatures and changes in rainfall patterns–they add more modulation to the water-use pattern.”

Kumar used a sophisticated model he and colleagues developed to study crops’ fine sensitivities to temperature and carbon dioxide changes in the atmosphere. The model incorporates the acclimation response of plants to changing climate.

Using the predictive model, the researchers found that net water use will increase further as a result of rising temperatures and carbon dioxide

Higher levels of carbon dioxide alone make the plants more water-efficient, since their pores are open less time to absorb carbon dioxide.

However, rising temperatures counteract this effect, as the plants will transpire more while their pores are open, losing more water than they save.

This additional water loss compounds the increase in water usage from land conversion.

In the U.S. Midwest, rainfall should remain sufficient to meet water demand, according to Kumar.

However, areas that rely on irrigation could find they have less water to meet higher demands, which could increase the net cost of large-scale land conversion and put pressure on already stressed water resources.

“If we’re going to solve energy problems through bioenergy crops, there are collateral issues that need to be considered,” Kumar said.

“Water is a significant issue. It’s already a scarce resource across the globe, and the need for it is only going to increase. The cost of that should be factored in to the decision making.”

___________________

Graduate student Phong V.V. Le and former postdoctoral researcher Darren Drewry, who is now at the Max Planck Institute in Germany, are co-authors of the paper.

The Vietnam Education Foundation also supported the research.

Kenya: Women at the Wheel

Parents’ stress leaves lasting marks on children’s genes: researchers say

Posted by Biomechanism

Researchers at the University of British Columbia and the Child & Family Research Institute have shown that parental stress during their children’s early years can leave an imprint on their sons’ or daughters’ genes – an imprint that lasts into adolescence and may affect how these genes are expressed later in life.

The study, published online today in the journal Child Development, focused on epigenetics – the expression of genes as opposed to the underlying sequence of DNA.  A central component of epigenetics is methylation, in which a chemical group attaches to parts of the DNA – a  process that acts like a dimmer on gene function in response to social and physical environments.

Michael S. Kobor, a UBC associate professor of medical genetics, measured methylation patterns in cheek cell DNA collected recently by University of Wisconsin researchers from more than 100 adolescents. These patterns were compared to data obtained by the University of Wisconsin in 1990 and 1991, when these same children were infants and toddlers, and their parents were asked to report on their stress levels – including depression, family-expressed anger, parenting stress and financial stress.

Comparing DNA methylation to stress, Kobor’s team found that higher stress levels reported by mothers during their child’s first year correlated with methylation levels on 139 DNA sites in adolescents. They also discovered 31 sites that correlated with fathers’ higher reported stress during their child’s pre-school years (three-and-a-half to four-and-a-half years old).

“To our knowledge, this is the first demonstration, using carefully collected longitudinal data, that parental adversity during a child’s first years leads to discernible changes in his or her ‘epigenome,’ measurable more than a decade later,” says Kobor, a scientist at the Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute (CFRI), and a Mowafaghian Scholar at the Human Early Learning Partnership (HELP). “This literally illustrates a mechanism by which experiences ‘get under the skin’ to stay with us for a long time.”

The team also found that fathers’ stress level is more strongly associated with DNA methylation in daughters, while mothers’ stress level has an effect with both boys and girls. This reinforces other research showing that the absence of fathers or their lack of participation in parenting is associated with an earlier onset of puberty and difficult temperamental traits in girls, but not in boys.

In general, none of the genes whose methylation level correlated with stress were among those best known to play a role in controlling a person’s behaviour or reaction to environmental stress. But they did find some genes that had a consistent change in methylation levels at more than one site on the DNA, including one involved in the production of insulin, the hormone that regulates blood sugar levels, and three other genes possibly involved in brain development.

“What is particularly intriguing is that a mother’s higher stress levels during infancy, but not during the preschool years, leads to epigenetic changes,” says co-author Clyde Hertzman, a professor in UBC’s School of Population and Public Health and director of HELP. “And the opposite is true for fathers – it’s their higher stress during a child’s preschool years, but not during their infancy, that counts.”

“These results confirm what early childhood experts have long known – those first few years are a crucial period that sets the stage for much of what happens to the individual later in life,” said co-author Thomas Boyce, a professor at UBC’s Human Early Learning Partnership and a scientist at CFRI. “It helps explain why a child’s socioeconomic status is the single most powerful predictor of childhood health and that individual’s lifelong health.”

______________________

The UBC team’s collaborators at the University of Wisconsin were Marilyn J. Essex, a professor of psychiatry, and Jeffrey Armstrong, a psychiatry researcher. UBC research assistants Lucia Lam and Sarah Neumann performed the work in Michael Kobor’s lab. The research was supported by the U.S. National Institute of Mental Health, the Canadian Institute for Advanced Research and the Djavad Mowafaghian Foundation.

Microscope on the go: Cheap, portable, dual-mode microscope uses holograms, not lenses

Posted by Biomechanism 

“Device described in Biomedical Optics Express could be used for field diagnostics in developing countries, testing of water quality, food contamination.”

Caption: In reflection mode, the holographic microscope can create images of dense, opaque materials, such as water filters. (a-b) Laser light from a laser diode (“LD” in the diagrams) is projected through a pin hole (“PH”) and then split into two beams by a beam cube (labeled “BC”). One beam of light hits the sample; the other does not. The beams are then reunited to form an interference pattern, which is recorded on a CMOS image sensor. (c) This photograph shows the microscope in reflection mode, with its cover removed. (The inset shows what the microscope looks like with its cover on.) The device weighs about 200 grams and is 15 cm long, 5.5 cm high, and 5 cm wide. Credit: Ozcan BioPhotonics Group at UCLA/Biomedical Optics Express.

To serve remote areas of the world, doctors, nurses and field workers need equipment that is portable, versatile, and relatively inexpensive. Now researchers at the University of California at Los Angeles (UCLA) have built a compact, light-weight, dual-mode microscope that uses holograms instead of lenses. The team describes the new device in a paper published today in the Optical Society’s (OSA) open-access journal Biomedical Optics Express.

Their prototype weighs about as much as a medium-sized banana and fits in the palm of a hand. And, since it relies in part on mass-produced consumer electronics, all the materials to make it add up to between $50 and $100 USD.

It also has a two-in-one feature: a transmission mode that can be used to probe relatively large volumes of blood or water, and a reflection mode that can image denser, opaque samples. The spatial resolution for both modes is less than two micrometers—comparable to that achieved by bulkier microscopes with low- to medium-power lenses.

“This is the first demonstration of essentially a hand-held version of a microscope that can do dual-mode imaging within a very compact and cost-effective form,” says Aydogan Ozcan, an associate professor of electrical engineering and bioengineering at UCLA and senior author of the paper.

With just a small amount of training, doctors could use devices like these to improve health care in remote areas of the world with little access to diagnostic equipment, Ozcan says. The handheld microscope could help ensure water quality, test patients’ blood for harmful bacteria, and even be used for semen-quality monitoring on animal farms.

It could also prove useful in health crises such as the recent outbreak of E. coli in Europe.

“It’s a very challenging task to detect E. coli in low concentrations in water and food,” Ozcan says. “This microscope could be part of a solution for field investigation of water, or food, or maybe pathogens in blood.”

Part of the device’s success is the weight it shed when researchers got rid of the bulkier, heavier, more expensive pieces that most microscopes rely on for collecting and focusing light: the lenses. Instead of lenses, this microscope uses holograms.

Holograms are formed when light bouncing off (or passing through) a three-dimensional object is made to interfere with a “reference beam,” or light that has not hit the object. Consider this analogy: drop a stone into a still pond and the ripples will move outward in a circle. Drop two stones and the circular ripples will interfere with each other, making a new pattern of crests and troughs. A person (or computer) analyzing the interference pattern created by those two stones could trace the source back to the stones and recreate what had happened to make the waves.

Caption: These pictures compare a piece of skin tissue imaged with the holographic microscope to the same piece of tissue imaged with a conventional microscope. The top two images (a-b) show the raw, unprocessed hologram -- the light interference pattern -- that is collected by the microscope’s sensor in reflection mode; the second image (b) is a zoomed-in version of the first (a). A computer-reconstructed image of this skin tissue is at the bottom left (c). The bottom right (d) shows a picture of the same specimen taken with a conventional, objective-lens microscope, for comparison. Credit: Ozcan BioPhotonics Group at UCLA/Biomedical Optics Express.

The UCLA team’s device uses a similar principle to recreate images from interfering light waves.

An inexpensive light source is divided into two beams —one that interacts with microscopic cells or particles in the sample, and the other that does not. The beams then pass to an adjacent sensor chip, where their interference pattern is recorded.

Software then analyzes that pattern and recreates the path taken by the light that passed through or bounced off of the objects being imaged.

Each component of the device is fairly inexpensive, Ozcan says. The laser light could come from a $5 laser pointer. The sensor chip that collects that light is the same as the ones in the backs of iPhones and Blackberrys and costs less than $15 per chip. And the whole image-collecting system runs on two AA batteries.

Where the researchers have reduced weight and expense in doing away with lenses, they have added the power of the cloud. The microscope captures raw data; but a computer is required to reconstruct the images. Workers in the field could use their laptops to process the information or send it over the Internet or mobile phone networks to a remote server. Mobile phones could also have sufficient processing power to do the analysis on the spot.

Essentially, Ozcan says, “we are replacing an expensive and bulky, heavy component with computer codes.”

The next steps for Ozcan’s team include commercializing the device. Ozcan says he has founded a company that is developing this technology, trying to make a version of the microscopes that can be manufactured and sold to healthcare workers and hobbyists.

“Global health is a big field that requires better diagnostic tools, because resource-poor countries don’t have the infrastructure for conducting essentially accurate diagnostic tests,” Ozcan says. “There are so many problems that innovative solutions [like this microscope] would impact.”

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Paper: “Field-portable reflection and transmission microscopy based on lensless holography,” M. Lee, O. Yaglidere, A. Ozcan, Biomedical Optics Express, Volume 2, Issue 9, p. 2721-2730.http://www.opticsinfobase.org/boe/abstract.cfm?uri=boe-2-9-2721

Grants for expeditions, fieldwork and independent travellers

Supporting outstanding research Fieldwork and expeditions have always been core to the Society's grants programme. Every year we support between 40 and 50 teams of students and researchers get into the field with a Geographical Fieldwork Grant, the Society's longest running grant scheme. Our independent travel grants support challenging and inspiring geographical journeys and expeditions. There are opportunities to challenge yourself physically and mentally through a Neville Shulman Challenge Award, and to make a radio documentary about an inspiring journey with a Journey of a Lifetime Award. Application deadlines are in September each year. Listen to RGS-IBG independent travel grant recipients talk about their research, illustrated with images from their fieldwork.    The Heart of Borneo Project: Murung Raya Expedition 2010/11, Neville Shulman Challenge Award recipient 2010

Earth could spread life across the Milky Way

 Space & Earth / Space Exploration 

Panspermia Illustration Courtesy of Wikipedia

Most of us are familiar with the concept of panspermia – where living organisms can be “seeded” from comet or asteroid impacts – but where does the life-giving content come from? According to a research group led by Mauricio Reyes-Ruiz from the National Autonomous University of Mexico, it just might come from Earth.

Inspired by the discovery of Moon and Mars rocks found on Earth from meteor strikes, the team began computer modeling of what might happen if pieces of Earth were transported across the Solar System via a collision scenario. The simulation involved 10,000 Earth particles moving over a period of 30,000 years. The amount of matter is tiny compared to the bulk our planet and it’s a blink of the eye in cosmic time, but scientists theorize that extreme lifeforms might be able to exist that long in space.

“The collision probability is greater than previously reported,” said Reyes-Ruiz. “It has been suggested that the ejection to interplanetary space of terrestrial crustal material, accelerated in a large impact, may result in the interchange of biological material between Earth and other Solar System bodies”

Could pieces of Earth really reach other planets? According to older theories, chances were good that some might reach the Moon or Venus, but gravity from the Sun and Earth makes reaching Mars improbable. However, the new simulations show a Mars impact – and even Jupiter – to be probable with the right ejection speeds. By involving slightly more particles at five times the rate of motion, the new results show the particles could even go beyond the Solar System. Oddly enough, the faster they moved, the lesser their chances of encountering the Moon and Venus became. Of the 10,242 tested, 691 particles ‘escaped’ out of the Solar System entirely, and six landed on Jupiter itself. Is this a Neil Young vision of flying Mother Nature’s silver seed to a new home?

Chris Shepherd of the Institute of Physics in London, who was not involved in the study, might agree with this conclusion. “This is an intriguing piece of work. The team have mapped out a really interesting scenario,” he said. One possible collision zone is Europa, the moon of Jupiter, and while the team did not simulate the number of particles that would specifically land there, many astronomers believe that it contains a large ocean, and could therefore support life.”

More information: Original Story Source: Cosmos Magazine News Release. For Further Study: Dynamics of escaping Earth ejecta and their collision probability with different Solar System bodies arXiv:1108.3375v1 [astro-ph.EP]

Source: Universe Today

"Earth could spread life across the Milky Way." September 2nd, 2011. http://www.physorg.com/news/2011-09-earth-life-milky.html

Posted by
Robert Karl Stonjek

Study suggests sexual orientation unconsciously affects our impressions of others

 Psychology & Psychiatry 

(Medical Xpress) -- Studies by psychologists at the University of Toronto reveal that when it comes to white men, being straight may make you more likable but in the case of black men, gays have a likeability edge.

In one study, 22 women and nine men viewed 104 photos of straight and gay black and white males and rated their likeability on a scale of one (not likable) to seven (extremely likable). Participants were not informed that some of the men pictured were gay. While overall, white straight men were rated as more likable than white gay men, black men were rated in the opposite manner: gay blacks were more likable than straight black men.

"We observed that people judge others based on sexual orientation even if they are not consciously aware of whether someone is gay or straight," said doctoral student Jessica Remedios, lead author. "By understanding how sexual orientation affects the rapid evaluations we form about others, we can learn more about predicting and minimizing the negative consequences of homophobia."

In a second study, 36 women and 14 men were divided into groups to view the same 104 photos. One group was instructed to approach whites and avoid blacks by pulling a joystick toward them when a white face appears and pushing the joystick away when a black face appears; the other group was instructed vice versa, to approach blacks and avoid whites.

Among participants approaching whites, the responses were faster for the straight men than for the gay. Among participants approaching blacks, however, responses were faster for gay than straight men. "Given that faster approach responses indicate greater positivity toward stimuli, the second study is consistent with the liking expressed in the first study," says Remedios.

"These findings suggest that sexual orientation, despite lacking explicit perceptual markers, infiltrates the automatic impression that is formed. Further, our judgment of gay men depends on whether they are white or black."

The paper "Impressions at the intersection of ambiguous and obvious social categories: Does gay + black = likable" was written with U of T associate professors Alison Chasteen, Nicholas Rule and Jason Plaks and published in the Journal of Experimental Psychology on June 12.

Provided by University of Toronto

"Study suggests sexual orientation unconsciously affects our impressions of others." September 2nd, 2011. http://medicalxpress.com/news/2011-09-sexual-unconsciously-affects.html

Posted by
Robert Karl Stonjek

Mind-Altering Bugs

 

Gut feeling. A steady diet of Lactobacillus rhamnosus (above) appears to reduce anxiety in mice.

Credit: Simko/Visuals Unlimited

Hundreds of species of bacteria call the human gut their home. This gut "microbiome" influences our physiology and health in ways that scientists are only beginning to understand. Now, a new study suggests that gut bacteria can even mess with the mind, altering brain chemistry and changing mood and behavior.

In recent years, researchers have become increasingly interested in how gut bacteria might influence the brain and behavior, says John Cryan, a neuroscientist at University College Cork in Ireland. So far, most of the work has focused on how pathogenic bugs influence the brain by releasing toxins or stimulating the immune system, Cryan says. One recent study suggested that even benign bacteria can alter the brain and behavior, but until now there has been very little work in this area, Cryan says.

To further investigate the mind-altering potential of benign bacteria, Cryan and colleagues at McMaster University in Canada fed mice a broth containing a benign bacterium, Lactobacillus rhamnosus. The scientists chose this particular bug partly because they had a handy supply and also because related Lactobacillus bacteria are a major ingredient of probiotic supplements and very little is known about their potential side effects, Cryan says.

In this case, the side effects appeared to be beneficial. Mice whose diets were supplemented with L. rhamnosus for 6 weeks exhibited fewer signs of stress and anxiety in standard lab tests, Cryan and colleagues report online today in the Proceedings of the National Academy of Sciences. For example, the rodents spent more time exploring narrow elevated walkways and wide-open spaces, which are scary to rodents, and they exhibited a smaller spike in stress hormone levels when the researchers put them in water. "This was really exciting because it tells us the animals are more chilled out and don't mount the same stress response," Cryan says.

In the brains of the treated mice, the researchers found changes in the activity of genes that encode portions of the receptor for the neurotransmiter GABA. GABA typically dampens neural activity, and many drugs for treating anxiety disorders target its receptors. The pattern of changes in the GABA receptors was complicated—more GABA receptors containing a certain component in some brain regions, for example, and fewer receptors with that component in other regions—but Cryan says they're consistent with an overall effect of reducing anxiety. None of these effects occurred in mice that ate a broth with no added bacteria.

The changes in GABA receptors and the antianxiety effects of L. rhamnosus disappeared when the researchers cut the vagus nerve before feeding the bacteria to mice. This nerve is a major conduit of sensory information from the gut to the brain, and this experiment shows it must be intact for L. rhamnosus to have an effect on the brain. The details of how the bacteria influence the brain through the vagus nerve still need to be elucidated, Cryan says. "That's what we have to figure out next."

"This is pioneering work," says Mark Lyte, a microbial endocrinologist at the Texas Tech University Health Sciences Center in Abilene. "It's really showing that you can alter emotional states by regulating the microbiome."

The findings "open up very exciting speculation" about using probiotics to treat mood disorders in people, says Emeran Mayer, a gastroenterologist at the University of California, Los Angeles. But Mayer says he's skeptical that the findings will translate easily from mice to people. "Personally, I think human emotional behavior is much more complex, so I don't think you'll ever find these kinds of dramatic responses." Lyte urges caution as well. "ItMAY, in really big capitals, prove to be an adjunct to therapy, but there are a number of steps that need to be done."

Source: Science
http://news.sciencemag.org/sciencenow/2011/08/mind-altering-bugs.html?ref=em&elq=d72499ffb6644da8a762e0462147c121

Posted by
Robert Karl Stonjek