PET

Use of PET can reduce, may eliminate more strenuous drug development trials with animals

A number of articles explore the use of positron emission tomography (PET) and small animal imaging--nonsurgical techniques that open the door to understanding and treating human diseases--in the April issue of the Society of Nuclear Medicine's Journal of Nuclear Medicine. A major benefit of small animal imaging "is the ability to carry out many studies at various time points with the same...

PET/MRI scans may help unravel mechanisms of prenatal drug damage

Scientists have demonstrated a new way to assess the potentially damaging effects of prenatal drug exposure--a technique that could also be used to monitor a fetus's response to therapeutic drugs--using sophisticated, noninvasive medical imaging tools. Scientists at the U.S. Department of Energy's Brookhaven National Laboratory, whose findings are reported in the February issue of the Society of...

Solutions that reduce death of marine life reeled in by International Smart Gear Competition

As the world prepared to observe Earth Day, World Wildlife Fund and its partners in the International Smart Gear Competition announced three new winning solutions to prevent the accidental maiming and killing of marine mammals, juvenile fish, and sea turtles that become ensnared by fishing nets and longlines--a problem known as bycatch--while also improving the efficiency of commercial fishing.</...

PET/CT can identify new cancer lesions at early stage, allowing for prompt treatment

A team of researchers at Johns Hopkins Medical Institutions in Baltimore, Md., reports that whole-body positron emission tomography/computed tomography (PET/CT) scans may help physicians identify new, unexpected malignant cancerous tumors in patients, according to an article in the May issue of the Society of Nuclear Medicine's Journal of Nuclear Medicine. "PET/CT can help find additional...

Rhesus monkeys can assess the visual perspective of others when competing for food

Researchers Jonathan Flombaum and Dr. Laurie Santos, both from Yale University, have found that rhesus monkeys consider whether a competitor can or cannot see them when trying to steal food. Working with semi-free-ranging rhesus monkeys on the island of Cayo Santiago in Puerto Rico, Flombaum and Santos set up a food competition game: Lone monkeys were approached by two human "competitors....

Revueltosaurus skeleton unearthed at Petrified Forest upsets dinosaur tale

The fossilized skeleton of a small crocodile relative excavated last year at Petrified Forest National Park in Arizona throws a wrench into theories of how and where the dinosaurs arose more than 210 million years ago at the end of the Triassic Period. The animal, one of many creatures from the Late Triassic known only from their teeth, was thought to be an ancestor of the plant-eating or...

Neandertal femur suggests competition with hyenas and a shift in landscape use

Analysis of approximately 41,000-year-old human remains found in France suggests that Neandertals may have become regionally mobile earlier than scientists once thought. Cédric Beauval and colleagues from Université Bordeaux 1 in France, Max Planck Institute in Germany, and Washington University in St. Louis, conclude that the human femur fragment found in 2002 in the cave of the Rochers-...

Bacteria use host's immune response to their competitive advantage

Millions of bacteria live within the recesses of our noses and upper respiratory tracts, waiting for a chance to infiltrate and infect. But long before these bacteria break through our immune defenses, they must first compete against other bacterial species to colonize the mucus-lined surfaces of our noses. Competition between two common nose bacteria involves some interesting trickery, ac...

Virtual animal shelters ?How the Internet is transforming the experience of pet adoptions

Across the United States, independent pet rescue organizations are growing in number, working to place abandoned animals in loving new homes. Although the majority of these organizations operate out of clusters of private foster homes, they're successfully winning high visibility for placing their pooches. In a presentation at the 100th annual meeting of the American Sociological Associati...

PET imaging reveals the immune system at work

For clinicians, the ability to look routinely inside the body and see -- at the level of the cell -- how it confronts disease is a distant dream. But in a series of experiments with genetically engineered mice, a team of researchers from the Howard Hughes Medical Institute (HHMI) at the University of California Los Angeles has taken a key step toward realizing that vision by demonstrating the abi...

Common practices at petting zoos put visitors at risk

While petting zoos pose a risk for gastrointestinal illness, most visitors aren't aware that simple prevention measures could prevent infection. In addition, some engage in behaviors that might increase their risk of infection according to several studies being presented this week at the International Conference on Emerging Infectious Diseases. Researchers from the CDC today release the r...

Study: Competition for sex is a 'jungle out there'

Mother Nature could use a few more good pollinators, especially in species-rich biodiversity hotspots, according to a new study in the Proceedings of the National Academy of Science (PNAS). Jana Vamosi, Ph.D, postdoctoral associate at the University of Calgary and Tiffany Knight, Ph.D., assistant professor of biology in Arts & Sciences at Washington University in St. Louis, and their c...

Study finds 60 new genes controlled by DNA snippet

Researchers worldwide are seeking to define ancient sections of our genetic code that may soon be as important to medical science as genes. A new wave of research is concerned with, not how genes work, but how small regulatory DNA sequences tell genes where, when and to what degree to "turn on." As part of this effort, researchers at the University of Rochester Medical Center scanned through the...

UCSD researchers develop 'smart petri dish'

Researchers at the University of California, San Diego have developed what they call a "Smart Petri Dish" that could be used to rapidly screen new drugs for toxic interactions or identify cells in the early stages of cancer circulating through a patient's blood. Their invention, described in the June 20 issue of Langmuir, a physical chemistry journal published by the American Chemical Soci...

Leptin found to control appetite and limb development in frogs

Leptin, the hormone secreted by fat cells that plays an important role in food intake, has been described for the first time in a cold-blooded vertebrate, the South African clawed frog Xenopus. As it does in humans and other mammals, leptin acts on the frog brain to suppress appetite. But the hormone also seems to play a role in the complex signaling that turns a finned tadpole into a fou...

Winning by a neck -- Giraffes avoid competing with shorter browsers

The giraffe's elongated neck has long been used in textbooks as an illustration of evolution by natural selection, but this common example has received very little experimental attention. In the January issue of the American Naturalist, researchers at the Mammal Research Institute in the Department of Zoology and Entomology at the University of Pretoria tested whether foraging competition with sh...

HIV exploits competition among T-cells

A new HIV study shows how competition among the human immune system's T cells allows the virus to escape destruction and eventually develop into full-blown AIDS. The study, which employs a computer model of simultaneous virus and immune system evolution, also suggests a new strategy for vaccinating against the virus ?a strategy that the computer simulations suggest may prevent the final onset of...

For Pacific white shrimp, gender matters when competing for food

Waimanalo, HI ?December 12, 2006 -- A new study in Journal of the World Aquaculture Society suggests that, while larger shrimp consistently win over smaller shrimp of the same gender when competing for food, male shrimp will almost always beat female shrimp ?even though adult males of the species are typically much smaller than the adult females of the same age. "Both size and gender are i...

PET imaging shows young smokers quick benefit of quitting

The early stages of coronary artery disease in young smokers can be reversed quickly if they choose to put out their cigarettes for good, according to a positron emission tomography (PET) imaging study in the December Journal of Nuclear Medicine. "I believe this is the first PET study that shows abnormal coronary function is reversible after only one month of smoking cessation," said Naga...

Low levels of neurotransmitter serotonin may perpetuate child abuse across generations

Infant abuse may be perpetuated between generations by changes in the brain induced by early experience, research shows at the University of Chicago shows. A research team found that when baby rhesus monkeys endured high rates of maternal rejection and mild abuse in their first month of life, their brains often produced less serotonin, a chemical that transmits impulses in the brain. Low...

Microbes compete with animals for food by making it stink

Microbes may compete with large animal scavengers by producing repugnant chemicals that deter higher species from consuming valuable food resources -- such as decaying meat, seeds and fruit, a new study suggests. Ecologists have long recognized microbes as decomposers and pathogens in ecological communities. But their role as classic consumers who produce chemicals to compete with larger...

Birth rate, competition are major players in hominid extinctions

Modern human mothers are probably happy that they typically have one, maybe two babies at a time, but for early hominids, low birth numbers combined with competition often spelled extinction. "The lineages of primates have some traits that make it hard for them to respond to rapid perturbations in the environment," says Dr. Nina G. Jablonski, professor of anthropology and department head a...

Scientists find method to pick noncompetitive animals, improve production

A new statistical method of determining genetic traits that influence social interactions among animals may provide for more productive livestock. Scientists from Purdue University, the Netherlands and England designed mathematical equations based on traits to choose animals that are more congenial in groups, said William Muir, a Purdue Department of Animal Sciences geneticist. The new me...

How appetite-stimulating brain cells work overtime during fasting

During periods of fasting, brain cells responsible for stimulating the appetite make sure that you stay hungry. Now, a new study of mice reported in the January issue of the journal Cell Metabolism, published by Cell Press, reveals the complex series of molecular events that keep those neurons active. The researchers revealed a link between active thyroid hormone in the brain and increase...

Red flag for repetitive stress injuries identified for first time in humans

For the first time in humans, scientists have found early indicators of inflammation ?potential warning signs ?in work-related injuries caused by repetitive motion. The new study from Temple University senior researchers Ann Barr and Mary...

Male owls pitch their hoots to advertise body weight to competitors

Why do male owls hoot? Researchers from the Centre d'Études Biologiques de Chizé (France) and the University of Sussex (UK) have studied the vocal communication of male European Scops owls, one of the smallest living species of nocturnal raptors. The study, published in the April issue of the American Naturalist, was conducted between June 2003 and June 2005 on the isle of Oléron, off the west co...