Berkeley biologists have a new tool to track and videotape cells moving about inside living tissue.
Called two-photon laser-scanning microscopy, it has revealed, for example, the dramatic difference between the random
wanderings of immature T cells and the goal-oriented, beeline movement of activated T cells.
"This is the first time anybody has quantitated four-dimensional data - spatial and time data - to get a picture of
long-range cell migrations through tissue," said immunologist Ellen Robey, professor of immunology at the University of
California, Berkeley. "The ability to directly visualize cells in living tissues has changed the way immunologists think
about how cells explore their environment, how they signal to each other, and how they migrate."
Robey and post-doctoral colleague Colleen Witt are among a handful of researchers using two-photon imaging to obtain
real-time images of cells throughout the top half-millimeter of a living organ, not just on the surface of tissue or within a
slice.
"In our earlier studies (published in Science) we could see cells getting together, presumably signaling one another. In our
current work, we observe cells that we believe have already gotten a signal beelining away," Robey said of her studies in the
thymus, the immune system gland that weans baby T cells into activated helper, or CD4, cells and killer, or CD8, cells primed
for combat with viral invaders. "We were surprised by how rapidly and directly the cells move to their final destination."
The technique could allow researchers in many fields of biology to track migrating cells, which biologists have discovered
are common in many types of tissue, ranging from nerves to lymph nodes. To date, such long-range migrations have been
inferred from observations of chemically fixed tissue at different stages of development.
"Two-photon imaging is going to change literally forever the way that we do biological science," said Witt, a developmental
immunologist. "In the past, we'd take organs out, smush them up and basically do biochemistry in test tubes, or watch their
behavior in a single layer of cells. It's an imaging revolution to be able to go into the native environment while keeping
the intact organ alive and make movies of migrating cells."
With two-photon imaging, Witt and Robey identified thymus cells they dubbed beeliners moving nearly two centimeters - almost
an inch - per hour, which is fast in the realm of cell movement. They think that these are cells that have received a signal
committing them to be either a helper T cell - which aids other immune cells in fighting infections - or a killer T cell that
seeks and destroys cells infected with virus.
On the other hand, uncommitted or immature T cells, what they call meanderers, wander slowly and apparently randomly around
the outer layer, or cortex, of the thymus, perhaps in search of that life-altering signal.
Robey hopes to use two-photon imaging to investigate the signals responsible for changing these meanderers into purposeful
beeliners that immediately leave the cortex for the interior medulla of the thymus.
"We're now at the point with this technology that we can begin to look at the movement of signaling molecules within the
cells," she said.
Robey, with another colleague, Philippe Bousso, last year published a review in the journal Immunity describing the
contributions two-photo imaging has made to the field. Robey and Witt publish their current study in the May 3 issue of the
Public Library Of Science-Biology.
Two-photon imaging is a variation on the standard technique of labeling cells with fluorescent dye and then hitting them with
a laser that makes the dye glow and the cells light up. A certain energy or color of laser light is needed to make the dye,
in this case green fluorescent protein, glow. But high-frequency, short-wavelength visible light, like green, doesn't
penetrate tissue as deeply as longer, redder wavelengths.
The idea behind two-photon imaging is that if you hit a dye molecule in a short period of time with two photons of light,
each photon half the energy needed to excite it, the dye can absorb them together and then fluoresce. The less energetic,
long-wavelength photons will go deeper into the tissue, cause less damage and scatter less, Robey said, essentially
illuminating slices through the tissue that can be sharply imaged and stacked to produce a 3-D image of the cells in real
time. The system they use employs an infrared laser emitting short intense pulses of 920 nanometer-wavelength light.
In the thymus, it's possible to view cells 400 microns inside the cortex, which is about 4/10 of a millimeter or more than a
hundredth of an inch deep. In the current study, Witt limited her viewing to about 200 microns, though she says in some
tissues less dense than the thymus, light could penetrate nearly a millimeter - deep enough to probe cell activity in most
tissues.
Witt pointed out that obtaining a movie of cell movement is just the beginning. The human eye and brain can't pick out
patterns of movement easily, so statistical techniques are needed to identify cells with different patterns of movement.
As an immunologist, Robey focuses on the lives of T cells produced in the thymus and distributed via the bloodstream to the
lymph nodes, whence they move into the body's tissues. Her first use of two-photon imaging three years ago surprised her and
many immunologists because it showed that thymocytes or immature T cells were highly mobile, traveling thousands of microns
in an hour as they explore the thymus.
The new experiments, conducted primarily by Witt, suggest that this exploration probably is a search for a signal that will
decide the cell's fate. In their experiments on one lobe of the mouse thymus, in fact, Witt and her colleagues saw cells,
possibly those that have made a decision on their fate, halt their wanderings and make a beeline out of the cortex to the
medulla, something immature T cells can't do.
The scenario they've reconstructed from the video and mathematical analysis starts with immature T cells moving out of the
center of the thymus, the medulla, to the very outside edge of the cortex, where they proliferate and fill up the cortex. At
this point, Witt said, they undergo the first of two tests to see if their surface receptors (called T cell receptors) work
properly.
Once they pass that test, they start wandering around in the cortex looking for the second test, which is to bind precisely
to a protein called the major histocompatibility complex (MHC). These cells, the researchers think, are the meanderers. Only
about one percent of thymocytes pass both tests, but Witt and Robey think that those that do are the ones they see beelining
out of the cortex into the medulla to begin their two-week education to distinguish "self" from "non-self" invader.
"To pass into the medulla they have to pass a screening test called positive selection," Witt said. "Once they do, the cells
move very directly at a very fast speed inward toward the medulla, adopting a polarized shape characteristic of migrating
cells."
While Witt and Robey continue their two-photon imaging studies of thymus cells and lymph cells, Witt is trying to encourage
the technology's use in biology generally.
"Immunology is just one example of a subdiscipline of biology that stands to benefit enormously from our new ability to see
in four-dimensions - in 3-D in real time. It opens an entirely different universe to us," Witt said.
Coauthors with Witt and Robey are Arup Chakraborty, UC Berkeley professor of chemistry; Subhadip Raychaudhuri, formerly of UC
Berkeley's chemistry department but now with the Department of Biomedical Engineering at UC Davis; and Brian Schaefer of the
Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Md.
The work was supported by grants from the National Institutes of Health.
Contact: Robert Sanders
rsandersberkeley
510-643-6998
University of California - Berkeley
berkeley
четверг, 26 мая 2011 г.
Nobel Prizes Won By Two More American Cancer Society Researchers
Two of the three scientists receiving the 2007 Nobel Prize for Physiology or Medicine received funding from the American Cancer Society early in their careers, bringing to 42 the number of Nobel Laureates among the Society's funded researchers.
Former grantees Mario R. Capecchi, Ph.D. of the University of Utah and Oliver Smithies, Ph.D., of the University of North Carolina are co-winners along with Sir Martin J. Evans of Cardiff University in Wales of the 2007 Nobel Prize in Physiology or Medicine for their groundbreaking discoveries that led to a technology known as gene targeting. Their work enabled scientists to develop targeted "gene knockout" mouse models that allows the study of specific genes involved in cancer, as well as in other diseases.
Like many Society-funded researchers, Drs. Capecchi and Smithies received American Cancer Society grants early in their careers, when funding is particularly hard to get. Dr. Capecchi received a four-year Faculty Research Award (FRA) from the American Cancer Society beginning July 1, 1974. Dr. Smithies received funds for an American Cancer Society Project Grant from July 1, 1974 -- December 31, 1976.
"Throughout its more than 60-year history, the American Cancer Society's research department has recognized the importance of funding promising grants by scientists whose careers are in their infancy," said John R. Seffrin, Ph.D., national chief executive officer of the American Cancer Society. "In just the past four years, seven Society-funded researchers have won the Nobel Prize, a remarkable achievement that is unmatched in the non-profit sector. We congratulate these researchers for receiving this proud honor, which stands as strong evidence of the strength of the Society's peer-review process and the credibility of its research grant program."
The American Cancer Society is dedicated to eliminating cancer as a major health problem by saving lives, diminishing suffering and preventing cancer through research, education, advocacy and service. Founded in 1913 and with national headquarters in Atlanta, the Society has 13 regional Divisions and local offices in 3,400 communities, involving millions of volunteers across the United States. For more information visit cancer/.
Source: David Sampson
American Cancer Society
Former grantees Mario R. Capecchi, Ph.D. of the University of Utah and Oliver Smithies, Ph.D., of the University of North Carolina are co-winners along with Sir Martin J. Evans of Cardiff University in Wales of the 2007 Nobel Prize in Physiology or Medicine for their groundbreaking discoveries that led to a technology known as gene targeting. Their work enabled scientists to develop targeted "gene knockout" mouse models that allows the study of specific genes involved in cancer, as well as in other diseases.
Like many Society-funded researchers, Drs. Capecchi and Smithies received American Cancer Society grants early in their careers, when funding is particularly hard to get. Dr. Capecchi received a four-year Faculty Research Award (FRA) from the American Cancer Society beginning July 1, 1974. Dr. Smithies received funds for an American Cancer Society Project Grant from July 1, 1974 -- December 31, 1976.
"Throughout its more than 60-year history, the American Cancer Society's research department has recognized the importance of funding promising grants by scientists whose careers are in their infancy," said John R. Seffrin, Ph.D., national chief executive officer of the American Cancer Society. "In just the past four years, seven Society-funded researchers have won the Nobel Prize, a remarkable achievement that is unmatched in the non-profit sector. We congratulate these researchers for receiving this proud honor, which stands as strong evidence of the strength of the Society's peer-review process and the credibility of its research grant program."
The American Cancer Society is dedicated to eliminating cancer as a major health problem by saving lives, diminishing suffering and preventing cancer through research, education, advocacy and service. Founded in 1913 and with national headquarters in Atlanta, the Society has 13 regional Divisions and local offices in 3,400 communities, involving millions of volunteers across the United States. For more information visit cancer/.
Source: David Sampson
American Cancer Society
Normal Adult Blood Can Generate Pluripotent Stem Cells, Study Reports
In findings likely to make it easier and faster for stem cell biologists to generate patient-specific embryonic-like stem cells, researchers at Children's Hospital Boston have reprogrammed adult blood cells into induced pluripotent stem (iPS) cells.
This advance will further enable scientists to model a patient's disease in a laboratory dish and potentially create healthy cells and tissues that match that patient immunologically. Instead of an invasive skin biopsy, the study shows that the cells can be obtained from the patient during a routine blood draw.
"A simple blood sample by venipuncture can provide adequate cells for reprogramming," said senior author George Daley, MD, Ph.D., a Howard Hughes Medical Institute investigator in Children's Stem Cell Program.
Last year, Daley's team first reported the generation of iPS cells from human blood, but the blood donors in that study had been specially treated with cytokines to mobilize more progenitor cells from the bone marrow. Such treatment often causes side effects, such as flu-like symptoms. "That brings us back to this work," said Yuin-Han "Jon" Loh, Ph.D., lead author and a postdoctoral fellow in the Daley lab. "We asked ourselves if we could reprogram blood cells from a normal donor."
The results, using cells from four healthy, untreated donors, are published in the July 2 Cell Stem Cell. In the same issue, two other research groups, including another Boston area lab, report similar findings.
"The generation of iPS cells from a small amount of peripheral blood collected from non-pretreated donors is an important step," wrote Shinya Yamanaka in an accompanying commentary. "It is reasonable to predict that the field may see a dramatic shift from using skin fibroblasts to peripheral blood as a source of iPS cells in the very near future." (Yamanaka's lab, in Japan, created the first human iPS cells in 2007.)
Embryonic-like iPS cells derived from patients can provide new insights into how diseases develop and what scientists can do to prevent or treat the diseases. Also, any tissue derived from iPS cells would be an immunological match, allowing for rejection-proof cell transplantation. Such advances are likely about 10 to 15 years away, estimates Daley, also a professor of biological chemistry and molecular pharmacology at Harvard Medical School.
iPS cells now mostly come from skin cells (fibroblasts) in a cumbersome process. In contrast, "we can culture iPS cells from blood in two days as opposed to three weeks with skin fibroblasts," Loh said. The process is about ten-fold less efficient, requiring about 1,000 adult blood cells for every one reprogrammed iPS cell, but a small blood draw provides more than enough extra starting cells, Loh says.
Scientifically, one important piece of evidence from the study showed that some of the iPS cells carried telltale genetic rearrangements of receptors of mature T cells. "This indicates that reprogramming does not simply select for pre-existing stem cells in the culture," Daley said.
The team started with blood from four healthy donors including one sample drawn from a colleague in the lab and three samples provided by co-authors at iPierian, a biotechnology company in South San Francisco. In their research, Loh and his colleagues had to develop new ways to grow the cells in suspension, rather than in a lab dish. They also had to develop a new technique to infect the cells with the viruses that carry the four genetic reprogramming factors into the adult cells.
"Importantly, peripheral blood cells can be isolated with minimal risk to the donor and can be obtained in sufficient numbers to enable reprogramming without the need for prolonged expansion in culture," the authors write in their paper. "Reprogramming from blood cells thus represents a fast, safe, and efficient way of generating patient-specific iPSCs."
Funding: National Institutes of Health; Howard Hughes Medical Institute; Systems-based Consortium for Organ Design & Engineering; Agency of Science, Technology, and Research and the Institute of Medical Biology, Singapore.
Children's Hospital Boston is home to the world's largest research enterprise based at a pediatric medical center, where its discoveries have benefited both children and adults since 1869. More than 1,100 scientists, including nine members of the National Academy of Sciences, 12 members of the Institute of Medicine and 13 members of the Howard Hughes Medical Institute comprise Children's research community. Founded as a 20-bed hospital for children, Children's Hospital Boston today is a 396-bed comprehensive center for pediatric and adolescent health care grounded in the values of excellence in patient care and sensitivity to the complex needs and diversity of children and families. Children's also is the primary pediatric teaching affiliate of Harvard Medical School.
Source: Children's Hospital Boston
This advance will further enable scientists to model a patient's disease in a laboratory dish and potentially create healthy cells and tissues that match that patient immunologically. Instead of an invasive skin biopsy, the study shows that the cells can be obtained from the patient during a routine blood draw.
"A simple blood sample by venipuncture can provide adequate cells for reprogramming," said senior author George Daley, MD, Ph.D., a Howard Hughes Medical Institute investigator in Children's Stem Cell Program.
Last year, Daley's team first reported the generation of iPS cells from human blood, but the blood donors in that study had been specially treated with cytokines to mobilize more progenitor cells from the bone marrow. Such treatment often causes side effects, such as flu-like symptoms. "That brings us back to this work," said Yuin-Han "Jon" Loh, Ph.D., lead author and a postdoctoral fellow in the Daley lab. "We asked ourselves if we could reprogram blood cells from a normal donor."
The results, using cells from four healthy, untreated donors, are published in the July 2 Cell Stem Cell. In the same issue, two other research groups, including another Boston area lab, report similar findings.
"The generation of iPS cells from a small amount of peripheral blood collected from non-pretreated donors is an important step," wrote Shinya Yamanaka in an accompanying commentary. "It is reasonable to predict that the field may see a dramatic shift from using skin fibroblasts to peripheral blood as a source of iPS cells in the very near future." (Yamanaka's lab, in Japan, created the first human iPS cells in 2007.)
Embryonic-like iPS cells derived from patients can provide new insights into how diseases develop and what scientists can do to prevent or treat the diseases. Also, any tissue derived from iPS cells would be an immunological match, allowing for rejection-proof cell transplantation. Such advances are likely about 10 to 15 years away, estimates Daley, also a professor of biological chemistry and molecular pharmacology at Harvard Medical School.
iPS cells now mostly come from skin cells (fibroblasts) in a cumbersome process. In contrast, "we can culture iPS cells from blood in two days as opposed to three weeks with skin fibroblasts," Loh said. The process is about ten-fold less efficient, requiring about 1,000 adult blood cells for every one reprogrammed iPS cell, but a small blood draw provides more than enough extra starting cells, Loh says.
Scientifically, one important piece of evidence from the study showed that some of the iPS cells carried telltale genetic rearrangements of receptors of mature T cells. "This indicates that reprogramming does not simply select for pre-existing stem cells in the culture," Daley said.
The team started with blood from four healthy donors including one sample drawn from a colleague in the lab and three samples provided by co-authors at iPierian, a biotechnology company in South San Francisco. In their research, Loh and his colleagues had to develop new ways to grow the cells in suspension, rather than in a lab dish. They also had to develop a new technique to infect the cells with the viruses that carry the four genetic reprogramming factors into the adult cells.
"Importantly, peripheral blood cells can be isolated with minimal risk to the donor and can be obtained in sufficient numbers to enable reprogramming without the need for prolonged expansion in culture," the authors write in their paper. "Reprogramming from blood cells thus represents a fast, safe, and efficient way of generating patient-specific iPSCs."
Funding: National Institutes of Health; Howard Hughes Medical Institute; Systems-based Consortium for Organ Design & Engineering; Agency of Science, Technology, and Research and the Institute of Medical Biology, Singapore.
Children's Hospital Boston is home to the world's largest research enterprise based at a pediatric medical center, where its discoveries have benefited both children and adults since 1869. More than 1,100 scientists, including nine members of the National Academy of Sciences, 12 members of the Institute of Medicine and 13 members of the Howard Hughes Medical Institute comprise Children's research community. Founded as a 20-bed hospital for children, Children's Hospital Boston today is a 396-bed comprehensive center for pediatric and adolescent health care grounded in the values of excellence in patient care and sensitivity to the complex needs and diversity of children and families. Children's also is the primary pediatric teaching affiliate of Harvard Medical School.
Source: Children's Hospital Boston
Critical Superparamagnetic/single-domain Grain-sizes In Interacting Magnetite Particles: Implications For Magnetosomes
Magnetotactic bacteria contain chains of magnetically interacting crystals (magnetosome crystals), which they use for navigation (magnetotaxis).
To improve navigation the magnetosome crystals (usually made of iron oxide) should be magnetically stable. Very small particles become magnetically unstable due to thermal excitation. Previous calculations for the stability threshold size not did include the contribution of magnetic interactions.
The inclusion of which, is found to decrease the threshold size, thereby increasing the range of stable magnetic behaviour. We argue that chains of interacting magnetosome crystals found in magnetotactic bacteria have utilized magnetic interactions to improve navigation.
Journal of the Royal Society Interface
Journal of the Royal Society Interface is the Society's cross-disciplinary publication promoting research at the interface between the physical and life sciences. It offers rapidity, visibility and high-quality peer review and is ranked fifth in JCR's multidisciplinary category. The journal also incorporates Interface Focus, a peer-reviewed, themed supplement, each issue of which concentrates on a specific cross-disciplinary subject.
Journal of the Royal Society Interface
To improve navigation the magnetosome crystals (usually made of iron oxide) should be magnetically stable. Very small particles become magnetically unstable due to thermal excitation. Previous calculations for the stability threshold size not did include the contribution of magnetic interactions.
The inclusion of which, is found to decrease the threshold size, thereby increasing the range of stable magnetic behaviour. We argue that chains of interacting magnetosome crystals found in magnetotactic bacteria have utilized magnetic interactions to improve navigation.
Journal of the Royal Society Interface
Journal of the Royal Society Interface is the Society's cross-disciplinary publication promoting research at the interface between the physical and life sciences. It offers rapidity, visibility and high-quality peer review and is ranked fifth in JCR's multidisciplinary category. The journal also incorporates Interface Focus, a peer-reviewed, themed supplement, each issue of which concentrates on a specific cross-disciplinary subject.
Journal of the Royal Society Interface
$1.2 Million Grant For Groundbreaking Approach To Brain Research Received By UT's Valentin Dragoi
An innovative approach to brain research developed by a scientist at The University of Texas Medical School at Houston has been selected for funding by a National Institutes of Health (NIH) initiative designed to support high-impact, medical investigations.
Valentin Dragoi, Ph.D., assistant professor of neurobiology and anatomy at the UT Medical School at Houston, has been awarded a four-year, $1.2 million grant through the initiative called Exceptional, Unconventional Research Enabling Knowledge Acceleration (EUREKA). The project is titled "Real-time population coding underlying behavioral decisions."
His approach to studying the brain could further the understanding of dissociative disorders that affect about one in 20 Americans.
Dragoi focuses on a region of the brain known as the cerebral cortex, which is a slender carpet of nerve cells or neurons that covers the cerebrum and plays a major role in sight, hearing and motor skills.
The brain is amazingly difficult to interpret because of the high degree of interconnectivity among brain networks, Dragoi said. For instance, sensory inputs are successfully processed by neuronal networks in different cortical areas. Each cortical area consists of multiple layers that contain characteristic patterns of connections with other cortical regions.
Whereas previous research has focused on individual neurons, Dragoi proposes to study the signals of populations of neurons in different regions of the cerebral cortex including visual cortex and high-level cortical areas. Tests will be conducted in an animal model.
"Examining how populations of neurons in multiple cortical areas interact to produce behavior may significantly increase our understanding of how neuronal networks operate in both normal and dysfunctional states," he said.
Dragoi said, "We made tremendous progress in understanding the language of individual neurons. Yet, how populations of cells communicate among each other to control behavior is virtually unknown. The new challenge in neuroscience is to decipher the language of populations of brain cells."
During the experiments, large populations of neurons will be recorded simultaneously using multiple, high-density electrode arrays in three key cortical areas involved in perceptual decisions, Dragoi said. "The experiments that we will perform have the potential to provide key insight into the dynamic transformations of the population code during a behavioral task," he said.
"Although the idea that behavior emerges from interactions among neuronal networks is not new, it has never been tested empirically under the framework of population coding," he said.
"The EUREKA award to Valentin Dragoi will be a major boost to his research on understanding the operation of normal and dysfunctional brain cortical neuronal networks and their impact on the decision-making processes of the brain. We can look forward to many significant scientific breakthroughs from this outstanding young scientist," said John H. Byrne, Ph.D., June and Virgil Waggoner Chair and chairman of the Department of Neurobiology and Anatomy at the UT Medical School at Houston
"It is a great honor for him, the department and the University of Texas Health Science Center at Houston. The fact that only a few grants were awarded within the entire National Institutes of Health is an indicator of the competitiveness of our neuroscience research program at the national level," Byrne said.
To receive a EUREKA grant, a research proposal must be linked to the mission of one of the NIH institutes. Dragoi's research is connected to the National Institute of Mental Health.
Valentin Dragoi received his doctorate at Duke University and completed a postdoctoral fellowship at the Massachusetts Institute of Technology. He is a recipient of numerous awards including the James S. McDonnell Award, the Pew Scholar Award and the Merck Award.
Source:
Robert Cahill
University of Texas Health Science Center at Houston
Valentin Dragoi, Ph.D., assistant professor of neurobiology and anatomy at the UT Medical School at Houston, has been awarded a four-year, $1.2 million grant through the initiative called Exceptional, Unconventional Research Enabling Knowledge Acceleration (EUREKA). The project is titled "Real-time population coding underlying behavioral decisions."
His approach to studying the brain could further the understanding of dissociative disorders that affect about one in 20 Americans.
Dragoi focuses on a region of the brain known as the cerebral cortex, which is a slender carpet of nerve cells or neurons that covers the cerebrum and plays a major role in sight, hearing and motor skills.
The brain is amazingly difficult to interpret because of the high degree of interconnectivity among brain networks, Dragoi said. For instance, sensory inputs are successfully processed by neuronal networks in different cortical areas. Each cortical area consists of multiple layers that contain characteristic patterns of connections with other cortical regions.
Whereas previous research has focused on individual neurons, Dragoi proposes to study the signals of populations of neurons in different regions of the cerebral cortex including visual cortex and high-level cortical areas. Tests will be conducted in an animal model.
"Examining how populations of neurons in multiple cortical areas interact to produce behavior may significantly increase our understanding of how neuronal networks operate in both normal and dysfunctional states," he said.
Dragoi said, "We made tremendous progress in understanding the language of individual neurons. Yet, how populations of cells communicate among each other to control behavior is virtually unknown. The new challenge in neuroscience is to decipher the language of populations of brain cells."
During the experiments, large populations of neurons will be recorded simultaneously using multiple, high-density electrode arrays in three key cortical areas involved in perceptual decisions, Dragoi said. "The experiments that we will perform have the potential to provide key insight into the dynamic transformations of the population code during a behavioral task," he said.
"Although the idea that behavior emerges from interactions among neuronal networks is not new, it has never been tested empirically under the framework of population coding," he said.
"The EUREKA award to Valentin Dragoi will be a major boost to his research on understanding the operation of normal and dysfunctional brain cortical neuronal networks and their impact on the decision-making processes of the brain. We can look forward to many significant scientific breakthroughs from this outstanding young scientist," said John H. Byrne, Ph.D., June and Virgil Waggoner Chair and chairman of the Department of Neurobiology and Anatomy at the UT Medical School at Houston
"It is a great honor for him, the department and the University of Texas Health Science Center at Houston. The fact that only a few grants were awarded within the entire National Institutes of Health is an indicator of the competitiveness of our neuroscience research program at the national level," Byrne said.
To receive a EUREKA grant, a research proposal must be linked to the mission of one of the NIH institutes. Dragoi's research is connected to the National Institute of Mental Health.
Valentin Dragoi received his doctorate at Duke University and completed a postdoctoral fellowship at the Massachusetts Institute of Technology. He is a recipient of numerous awards including the James S. McDonnell Award, the Pew Scholar Award and the Merck Award.
Source:
Robert Cahill
University of Texas Health Science Center at Houston
Lyme Disease-Causing Microbes Seen Moving In Ticks
Lyme disease is caused by the microbe Borrelia burgdorferi, which is transmitted to humans from feeding ticks. Justin Radolf and colleagues, at the University of Connecticut Health Center, Farmington, have now visualized the microbe moving through the feeding tick and determined that it has a biphasic mode of dissemination. These data provide new insight into the transmission process, detailed understanding of which is essential if new methods of preventing human infection with the Lyme disease-causing microbe are to be developed.
In this study, the midguts and salivary glands of ticks before, during, and after feeding were isolated, and the live Borrelia burgdorferi microbes imaged in real time. In the first phase of dissemination, replicating microbes formed networks of nonmotile organisms that moved by adhering to the cells lining the tick midgut. In the second phase of dissemination, the microbes became motile invasive organisms that ultimately entered the salivary glands. These data challenge the conventional viewpoint that Lyme disease-causing microbes are always motile within ticks and that this drives their dissemination.
TITLE: Live imaging reveals a biphasic mode of dissemination of Borrelia burgdorferi within ticks
Author: Justin D. Radolf
View this article at: jci/articles/view/39401?key=HnLk45JRxih3aqbS4YCQ
Source: Karen Honey
Journal of Clinical Investigation
In this study, the midguts and salivary glands of ticks before, during, and after feeding were isolated, and the live Borrelia burgdorferi microbes imaged in real time. In the first phase of dissemination, replicating microbes formed networks of nonmotile organisms that moved by adhering to the cells lining the tick midgut. In the second phase of dissemination, the microbes became motile invasive organisms that ultimately entered the salivary glands. These data challenge the conventional viewpoint that Lyme disease-causing microbes are always motile within ticks and that this drives their dissemination.
TITLE: Live imaging reveals a biphasic mode of dissemination of Borrelia burgdorferi within ticks
Author: Justin D. Radolf
View this article at: jci/articles/view/39401?key=HnLk45JRxih3aqbS4YCQ
Source: Karen Honey
Journal of Clinical Investigation
$100,000 Grand Challenges Explorations Grant Received By Monell Center
The Monell Center has announced that it has received a US$100,000 Grand Challenges Explorations grant from the Bill & Melinda Gates Foundation. The grant will support an innovative global health research project conducted by Paul A. S. Breslin, PhD, titled "Taste-Guided Behavior on Mosquitoes Helps Eradicate Malaria."
Dr. Breslin's project is one of 81 grants announced by the Gates Foundation in the second funding round of Grand Challenges Explorations, an initiative to help scientists around the world explore bold and largely unproven ways to improve health in developing countries. The grants were provided to scientists in 17 countries on six continents.
To receive funding, Breslin showed in a two-page application how his idea falls outside current scientific paradigms and might lead to significant advances in global health. The initiative is highly competitive, receiving more than 3,000 proposals in this round.
Breslin's grant focuses on the sense of taste in mosquitoes, with the overall goal of identifying new strategies to reduce transmission of malaria. Taste provides information that regulates whether a substance will be ingested as food or rejected. As such, the final decision of whether or not a mosquito will initiate a meal of human blood depends on how human skin tastes to the mosquito. Currently, little is known about the taste world of mosquitoes. Dr. Breslin proposes that a deeper understanding of mosquito taste will reveal novel approaches to the design of strategies to reduce mosquito-mediated disease transmission. As a first step, the studies funded by the Grand Challenges Explorations grant will assess taste responses of mosquitoes to a range of human skin compounds.
Paul Breslin is a sensory psychobiologist and geneticist at the Monell Chemical Senses Center in Philadelphia. The Grand Challenges Explorations mosquito project is an extension of his longstanding interests in taste and feeding. Breslin's Drosophila Chemosensory Laboratory at Monell uses the fruit fly as a model to understand the relationships between genetics, chemosensation, and feeding. Parallel studies in Breslin's lab address the genetics of taste, smell, and chemical irritation in humans.
"By deterring mosquito tasting on human skin, we can help to stop the transmission of devastating diseases such as malaria," said Breslin. "The Grand Challenges Explorations grant will enable us to find out what it is about humans that mosquitoes find tasty. With that critical piece of information, we can then develop inhibitors to those substances. Once humans no longer taste good to mosquitoes, they will no longer use us as food."
"The winners of these grants are doing truly exciting and innovative work," said Dr. Tachi Yamada, president of the Gates Foundation's Global Health Program. "I'm optimistic that some of these exploratory projects will lead to life-saving breakthroughs for people in the world's poorest countries."
Source:
Leslie Stein
Monell Chemical Senses Center
Dr. Breslin's project is one of 81 grants announced by the Gates Foundation in the second funding round of Grand Challenges Explorations, an initiative to help scientists around the world explore bold and largely unproven ways to improve health in developing countries. The grants were provided to scientists in 17 countries on six continents.
To receive funding, Breslin showed in a two-page application how his idea falls outside current scientific paradigms and might lead to significant advances in global health. The initiative is highly competitive, receiving more than 3,000 proposals in this round.
Breslin's grant focuses on the sense of taste in mosquitoes, with the overall goal of identifying new strategies to reduce transmission of malaria. Taste provides information that regulates whether a substance will be ingested as food or rejected. As such, the final decision of whether or not a mosquito will initiate a meal of human blood depends on how human skin tastes to the mosquito. Currently, little is known about the taste world of mosquitoes. Dr. Breslin proposes that a deeper understanding of mosquito taste will reveal novel approaches to the design of strategies to reduce mosquito-mediated disease transmission. As a first step, the studies funded by the Grand Challenges Explorations grant will assess taste responses of mosquitoes to a range of human skin compounds.
Paul Breslin is a sensory psychobiologist and geneticist at the Monell Chemical Senses Center in Philadelphia. The Grand Challenges Explorations mosquito project is an extension of his longstanding interests in taste and feeding. Breslin's Drosophila Chemosensory Laboratory at Monell uses the fruit fly as a model to understand the relationships between genetics, chemosensation, and feeding. Parallel studies in Breslin's lab address the genetics of taste, smell, and chemical irritation in humans.
"By deterring mosquito tasting on human skin, we can help to stop the transmission of devastating diseases such as malaria," said Breslin. "The Grand Challenges Explorations grant will enable us to find out what it is about humans that mosquitoes find tasty. With that critical piece of information, we can then develop inhibitors to those substances. Once humans no longer taste good to mosquitoes, they will no longer use us as food."
"The winners of these grants are doing truly exciting and innovative work," said Dr. Tachi Yamada, president of the Gates Foundation's Global Health Program. "I'm optimistic that some of these exploratory projects will lead to life-saving breakthroughs for people in the world's poorest countries."
Source:
Leslie Stein
Monell Chemical Senses Center
Подписаться на:
Сообщения (Atom)