April 8, 2013
(Editor's Note: Thomas Scott on National Public Radio (NPR))
“Dengue takes an enormous toll on human health worldwide, with as many as 4 billion people at risk,” said Scott, professor of entomology at UC Davis and chair of the mosquito-borne disease modelling group in the Research and Policy for Infectious Disease Dynamics (RAPIDD) program of the Science and Technology Directory, Department of Homeland Security, Fogarty International Center, National Institutes of Health.
“The results of our study and infrastructure that created the dengue maps fill a critical gap in the battle against dengue,” said Scott, a worldwide expert on the epidemiology and prevention of dengue who maintains field research programs in Iquitos, Peru, and Khamphaeng Phet, Thailand. “Prior to this, without rigorously derived dengue estimates that can be continuously updated, it was not possible to know with confidence where and when to direct interventions for greatest potential impact or to objectively assess the effectiveness of regional and global control efforts. That kind of knowledge was among the most important missing information for developing enhanced dengue prevention programs.”
“Although we knew that dengue is a growing problem, our results more precisely identify trends in different regions of the world, identify regions that merit greater attention, estimate the number of clinically apparent versus inapparent infections,” Scott said, “and we hope will the basis for increased discussion and research on the best ways to reverse this expanding public health threat.”
WHO earlier reported that some 500,000 people with severe dengue are hospitalized each year, and less than 2.5 percent of those affected die if they receive properly clinical management.
“There are currently no licensed vaccines or specific therapeutics, and substantial vector control efforts have not stopped its rapid emergence and global spread,” the researchers wrote.
Dengue has now begun to appear along the southern border of the United States, including Texas. Florida has also reported cases of dengue.
The researchers assembled known records of dengue occurrence worldwide and used a formal modelling framework to map the global distribution of dengue risk. They then paired the resulting risk map with detailed longitudinal information from dengue cohort studies and population surfaces to infer the public health burden of dengue in 2010.
Professor Simon Hay of the University of Oxford led the research, as part of the International Research Consortium on Dengue Risk Assessment, Management and Surveillance.
Of the 96 million clinically apparent dengue infections, Asia bears 70 percent of the burden, the research paper revealed. India alone accounts for around one-third of all infections. In a press release issued today by Nature: “The results indicate that with 16 million infections, Africa’s burden is almost equivalent to that of the Americas and is significantly larger than previously appreciated. The authors suggest that the hidden African dengue burden could be a result of the disease being masked by symptomatically similar illnesses, under-reporting and highly variable treatment-seeking behaviour.”
The International Research Consortium on Dengue Risk Assessment, Management and Surveillance is a multinational team of researchers funded by the European Commission to develop new and innovative tools to be applied to the control of dengue in a global context.
The study also received funding from the Wellcome Trust; Li Ka Shing Foundation; and the Science and Technology Directory, Department of Homeland Security, and Fogarty International Center, National Institutes of Health.
The publication of the findings coincides with the first regional meeting of the World Health Summit in Singapore, where health care policy makers, experts, and practitioners are meeting to exchange ideas and find solutions for today’s health challenges in Asia.
(Editor's Note: Thomas Scott is featured today (April 8) on NPR, and also will be interviewed today by Brazilian BANDNEWS FM, and in the United States by REDE, and CNN.)
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
April 10, 2013
His seminar is from 12:05 to 1 p.m. Professor Greg Lanzaro of the UC Davis School of Veterinary Medicine will introduce him. Plans are to video the seminar for later posting on UCTV.
"Anopheles gambiae is the most important malaria vector in the world,” he says. “Remarkable adaptive flexibility has enabled this mosquito to track humans across the diverse ecoclimates of sub-Saharan Africa where it thrives in both highly mesic and xeric conditions. These rapid, recent ecological adaptations have driven incipient speciation into two ecotypes, which differentially exploit permanent and temporary larval habitats. Within each nascent species, abundant chromosomal inversion polymorphisms facilitate adaptation to local conditions along latitudinal environmental gradients."
“To elucidate the genetic basis of ecological adaptation in Anopheles gambiae, we performed a series of genome-wide divergence scans, which revealed candidate regions subject to recent natural selection. Dissection of one of these genomic regions established a link between naturally occurring allelic variation and an adaptive phenotype. In the context of evolutionary genomics, these studies shed light on the maintenance of inversion polymorphisms and also provide insight into the genomic architecture of reproductive isolation. From a public health standpoint, this work demonstrates how divergent ecological selection can impact the vectorial capacity of Anopheles gambiae -- with consequences for malaria epidemiology and control.”
White began working on mosquitoes when he was an undergraduate at Oberlin College in Ohio. “At the time, West Nile virus (WNV) was sweeping through the midwest and during the summers I participated in a project to identify the Culex vectors of WNV and to determine environmental factors affecting their abundance,” he said. “After leaving Oberlin, I spent the next seven years in Nora Besansky's lab at Notre Dame where I focused on the population genomics of the African malaria mosquito Anopheles gambiae."
White joined the UC Riverside Department of Entomology faculty in 2011. His research focuses on quantitative and functional genomics of Anopheline malaria vectors.
More information is on his website at http://www.mosquitogenomics.org.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
(Editor's Note: News embargo lifted at 12 noon, April 1, Pacific Daylight Time. The research paper was posted on the PNAS website April 3.)
April 1, 2013
In groundbreaking research, the team of 16 scientists led by Dr. Guodong Zhang of the Bruce Hammock laboratory, Department of Entomology and the UC Davis Comprehensive Cancer Center, discovered cytochrome P450 epoxygenase metabolites of omega-3 fatty acid DHA or epoxy docosapentaenoic acids (EDPs) block blood supply to the tumor and thus inhibit tumor growth and metastasis.
The natural EDPs were further stabilized by a drug called a soluble epoxide hydrolase inhibitor which is already under development to control pain and hypertension. The research was published April 3 in the Proceedings of the National Academy of Sciences (PNAS).
“Many human studies have shown that omega-3 fatty acids reduce the risks of cancers, but the mechanism is poorly understood,” said Zhang, a postdoctoral researcher. “Our study provides a novel mechanism by which these omega-3 lipids inhibit cancer.”
“We demonstrated that EDPs have very potent anti-cancer and anti-metastatic effects,” Zhang said. “Current anti-cancer drugs that block angiogenesis (the formation of new blood vessels to fuel tumor progression) can cause serious side effects such as hypertension. By blocking angiogenesis by a new mechanism and by widening blood vessels, EDPs could block tumor growth with reduced side effects in cancer patients.”
Co-author Hammock, a distinguished professor of entomology with a joint appointment at the UC Davis Comprehensive Cancer Center, said the research shows lots of promise. “Basically what Dr. Zhang and his collaborators found is that the epoxides of the omega 3 fatty acid DHA are strongly anti-angiogenic and block tumor growth and metastasis. He used the soluble epoxide hydrolase inhibitors to stabilize these epoxides in mice. In contrast, the epoxides of the omega 6 fatty acid ARA (arachidonate) are mildly angiogenic and encourage tumor and wound healing.”
“Thus the effects of the soluble epoxide hydrolase inhibitors have opposite effects depending on whether the background lipid mediators are omega 3 or omega 6,” Hammock said. “Assuming that humans are mice (the study involved mice), the prediction is that with some cancer drugs--particularly the ones like sorafenib and regorafenib that are potent epoxide hydrolase inhibitors as well as anti-angiogenic agents--these could be more effective with a high omega 3 and low omega 6 background.”
Said co-author and chemist Sung Hee Hwang: “This is exciting work as a chemist to be involved in; not only was there a strong team of chemists, biochemists and analytical chemists working with Guodong, but we got the chance to collaborate with the bioengineers from the Katherine Ferrara laboratory who did the imaging as well as with some top cancer researchers from UC Davis and Harvard.”
“This is an exciting step towards our full appreciation of the impact of bioactive products from the DHA metabolome,” said Charles Serhan of Harvard Medical School, an expert on omega-3 autacoids and inflammation who is the Simon Gelman Professor of Anesthesia, Periopterative and Pain Medicine, Harvard Medical School. “This (UC Davis) contribution places metabolic conversion of omega-3 DHA to epoxy DHA products pivotal in vascular mechanisms key in cancer and vascular biology. It will be exciting to watch these important findings translated to humans for new evidence based treatments for angiogenesis, tumor growth and cancer metastasis.”
Cardiologist Jonathan Lindner of the Oregon Health & Science University lauded the research.
“The study by Zhang and colleagues has uncovered a previously unrecognized anti-cancer effect of omega-3 fatty acids which are an important lipid component of diets that have been developed to prevent heart disease and cancer,” Lindner said. “The authors have demonstrated that metabolites of these lipids can act to suppress the growth of new blood vessels that are necessary to feed tumor growth. By shutting off the tumor’s blood supply, these compounds can act to dramatically slow tumor growth and prevent metastasis. The results from this suggest that new drug strategies for fighting cancer could emerge from knowledge of how the body uses nutrition to promote health.”
“Now UC Davis researchers report that the epoxides of docosahexaenoic acid do exactly the opposite by inhibiting angiogenesis, and thus decrease tumor growth and metastasis,” Fleming said. “Thus, it may now be possible to potentate the beneficial effects of sEH inhibition by supplementing therapy with dietary omega-3 fatty acids.”
Lois Smith, professor of ophthalmology at the Harvard Medical School and Boston Children’s Hospital, commented: “Fish oil (enriched in ω3 polyunsaturated fatty acids; ω3-PUFAs) has been shown to reduce the occurrence of diseases associated with abnormal vessel development such as age-related macular degeneration and retinopathy of prematurity. In this study, Zhang et al. demonstrate that epoxydocosapentaenoic acids (EDPs), the metabolites of ω3-PUFA by cytochrome P450 enzymes inhibits vessel development in tumors and suppresses tumor growth and metastasis by reducing VEGF-C production. This discovery provides a novel mechanism of ω3-PUFAs action on vessels and tumors and may lead to new therapies.”
Zhang, who focuses his research on lipid mediators on angiogenesis, tumor growth and metastasis, received his doctorate in food science from the University of Wisconsin-Madison.
Cancer, characterized by uncontrolled growth and spread of abnormal cells, can be caused by external factors such as tobacco, infectious organisms, chemicals and radiation, and by internal factors such as inherited mutations, hormones, immune conditions and mutations that occur from metabolism, according to the National Cancer Institute. Death occurs when the cancer is not controlled. Some 1.6 million new cases of cancer are expected to be diagnosed this year. Cancer, the second most common cause of death in the United States, is exceeded only by heart disease.
Other co-authors of the paper in addition to Hammock were Jun Yang, Jun-Yan Liu, King Sing Stephen Lee, Arzu Ulu, and Sung Hee Hwang, all of the UC Davis Department of Entomology and UC Davis Comprehensive Cancer Center; Lisa Mahakian, Xiaowen Hu, Katherine Ferrara, Sarah Tam, and Elizabeth Ingham, UC Davis Department of Biomedical Engineering; Hiromi Wettersten of the UC Davis Division of Nephrology, Department of Internal Medicine; Robert Weiss, Comprehensive Cancer Center, Division of Nephrology and U.S. Department of Veterans’ Affairs Medical Center, Sacramento; and Dipak Panigrahy and Mark Kieran of the Vascular Biology Program, Children’s Hospital, Harvard Medical School.
The research project received funding support from the National Institute on Environmental Health Sciences Superfund (Bruce Hammock); UC Davis Research Investments in the Sciences and Engineering (RISE) Program (Katherine Ferrara); NIH research grant (Dipak Panigrahy); Stop and Shop Pediatric Brain Tumor Fund and the C. J. Buckley Pediatric Brain Tumor Fund (Mark Kieran); and the Medical Service of the U.S. Department of Veterans’ Affairs (Robert Weiss). Hammock is a George and Judy Marcus Senior Fellow of the American Asthma Society.
Link to PNAS Paper
National Institute of Environmental Health Science (NIEHS) website
Contact:
Guodong Zhang at gdzhang@ucdavis.edu
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
(From UC Davis News Service and Department of Entomology)
April 1, 2013
He is one of four young UC Davis faculty members selected for the award. Others are Ken Loh, assistant professor in the Department of Civil and Environmental Engineering, who received $400,000; Stephen O'Driscoll, assistant professor in the Department of Electrical and Computer Engineering, who received $400,000; and Ilias Tagkopoulos, assistant professor in the Department of Computer Science and the UC Davis Genome Center, who received $600,000. Together they received $2 million.
The NSF fund projects aimed at developing new nanomaterials, smaller medical implants, "biological circuits" and a better understanding of timing in ecosystems.
Yang is studying the importance of timing in interactions between plants, animals and their environment, specifically studying the monarch butterfly and milkweed. Species interactions change with the seasons and with different life stages, and climate change may disrupt these interactions, for example, if caterpillars emerge before food sources are available. His $600,000 award will support work that will provide new knowledge about how natural communities respond to such changes.
Yang was also recently selected as a UC Davis Hellman Fellow and will be honored at a luncheon in May of 2014. He received a $10,000 award to support his research activities investigating the timing of milkweed (Asclepias spp.) and monarch (Danaus plexippus) interactions in western North America due to climate change. His research addresses two main questions: “How has the relative timing of species interactions changed in the recent past?” and “What are the fitness consequences of phenological shifts?”
Yang's research interests include community ecology, species interactions, temporal variation, extreme events in nature, and the integration of ontogeny and phenology.
Yang earned his bachelor's degree (ecology and evolution) from Cornell University in 1999 and his doctorate from UC Davis in 2006, studying with entomology professor and ecologist Rick Karban. Yang conducted postdoctoral research at UC Santa Barbara before returning to UC Davis as a faculty member in 2009. While at UC Santa Barbara, he served as a UC President’s Postdoctoral Fellow in the Department of Ecology, Evolution and Marine Biology.
NSF's Faculty Early Career Development Program supports junior faculty who perform outstanding research, are excellent educators, and who integrate education and research in their work. The awards, known as CAREER awards, typically support both a five-year research program and a program of outreach and education in local schools and colleges.
Including these latest awards, current UC Davis faculty members have held a total of 63 NSF CAREER awards.
See UC Davis News Release by Andy Fell
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
April 3, 2013
Katharina Ullmann of the Neal Williams lab is the host. The seminar is scheduled to be recorded for later viewing on UCTV.
“Increasing demands for food, and now fuel, have put pressure on our agricultural lands,” Gratton says. “Land use and land cover are continuing to change the way we manage our lands with significant biological and ecosystem-level consequences.”
“The ‘simplification’ of the agricultural landscape, that is the removal of natural and semi-natural areas in the landscape and the increase in monocultures of annual crops, is typically associated with a decrease in species richness and increases in crop pest abundance,” he said. “ These effects go beyond mere aesthetics. The consequences of landscape simplification are felt by growers who apply more pesticides in landscapes dominated by annual cropland. The question then, is can we balance our needs for agricultural production (both food and fuel) in a way that supports other ecosystem services on which we as humans depend?”
“I argue that understanding the relationships between landscape structure and the tradeoffs between ecosystem services will be a key a designing ‘custom’ multifunctional landscapes.”
Gratton joined the University of Wisconsin faculty in 2003. His research group works broadly in the field of landscape ecology in both agricultural and natural systems. In Wisconsin agriculture, he has been interested in understanding how beneficial insects, such as pollinators and lady beetles, utilize the landscape and carry out important functions such as pollination of crops and suppression of insect pests.
His work in agroecology has included studying insect landscape ecology and conservation in potatoes, rotational grazing, grasslands, soybeans, cranberries, apples.
Gratton has worked with growers to understand how to best manage non-crop “natural” areas in the landscape in order to enhance and conserve beneficial insects. He is also an active member of the Great Lakes Bioenergy Research Center as part of the team looking at developing sustainable bioenergy crops. He teaches courses in Insect Biological Control, Multivariate Analysis and Coastal Field Ecology.
He received his bachelor of science degree in biology from the University of Illinois in 1991 and his doctorate in entomology from UC Berkeley in 1997.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894