OREGON STATE UNIVERSITY

scientific research and advances

The golden drool: Study finds treasure trove of info in saliva of foraging bears

CORVALLIS, Ore. – The rivers and streams of Alaska are littered in the summer and fall with carcasses of tens of thousands of salmon that not only provide a smorgasbord for hungry brown bears but are also the newest database in the arsenal of wildlife biologists.

A new study, published this week in the journal PLOS ONE, documents the ability of researchers to gather DNA from residual saliva on partially consumed salmon to the point that they can even identify individual bears from the genetic samples. The discovery should provide a significant boost to research on the population and health of brown bears, which can grow to a size of 1,500 pounds. 

“In the past, population estimates have been largely based on visual observations and on the analysis of fecal samples,” said Taal Levi, an assistant professor of fisheries and wildlife at Oregon State University and co-author on the study. “We found that using bear saliva is not only easier and cheaper as a research tool, it is more effective.”

In their study, the researchers examined 156 partially consumed salmon carcasses of lakeshore-spawning sockeye salmon in the Chilkoot watershed and stream-spawning chum salmon at Herman Creek in the Klehini watershed – both near Haines, Alaska. They also swabbed a total of 272 brown bear “scats,” or fecal samples, from those same locations. 

They found that the saliva collected from the salmon carcasses delivered a higher rate of genotyping success, allowing the researchers to identify individual bears more accurately and quickly than the fecal samples, and required significantly less labor.

“Bears love salmon because they are such a rich food source, and fortunately for us, the way they consume them lends itself to genetic monitoring,” said the study’s lead author, Rachel Wheat, who conducted the research as part of her doctoral dissertation at the University of California, Santa Cruz. 

“When salmon are plentiful, bears rarely eat the entire fish. In some cases, they only eat the brain, and we’ve found that swabbing along the edges of the braincase gives us the best results for extracting DNA,” Wheat said. “We also had success with swabbing inside distinct bite holes, and in the muscle tissue where the bears have stripped the skin off the salmon.”

The researchers were able to get brown bear genotypes for 55 percent of all the salmon carcasses sampled for saliva, compared to 34 percent for the scat samples. 

From a purely cost-savings perspective, the saliva sampling proved cheaper. It costs the researchers roughly $370 per bear to genetically identify individual animals using scat samples; the cost with saliva samples dropped to $118.

“This advance will help allow us to more effectively – and more economically – study one of the largest bears on the planet,” Wheat said. 

Levi agreed and also noted that the method does not have to be restricted to bear research. It could be adapted to other species, as well.

 “Many predators leave saliva on food remains,” he said. “We feel this type of saliva sampling could become an important tool for wildlife population monitoring.”

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Taal Levi, 541-737-4067, taal.levi@oregonstate.edu; Rachel Wheat, 719-439-3397, r.e.wheat@gmail.com

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Bear with salmon (Photo by Jennifer Allen)

Bear with salmon

Chum salmon (Photo by Rachel Wheat)

Chum salmon

Kelp forests globally resilient, but may need local solutions to environmental threats

CORVALLIS, Ore. – The first global assessment of marine kelp ecosystems shows that these critically-important habitats have exhibited a surprising resilience to environmental impacts over the past 50 years, but they have a wide variability in long-term responses that will call for regional management efforts to help protect their health in the future.

The findings were published today in Proceedings of the National Academy of Sciences.

Scientists noted that kelp forests have a remarkable ability to recover quickly from extreme damage, but they can still be overwhelmed in some instances by the combination of global and local pressures.

This points to the need for regional management efforts that carefully consider local conditions when trying to offset human-caused impacts from climate change, overfishing and direct harvests, researchers said.

Kelp forests, the largest species of algae in shallow, coastal waters almost everywhere except the tropics, are a globally important foundation species that occupy almost half of the world’s marine ecoregions. Often harvested directly, they help support commercial fisheries, nutrient cycling, shoreline protection, and are valued in the range of billions of dollars annually.

The new research was conducted by an international team of 37 scientists who analyzed changes in kelp abundance in 34 regions of the planet that had been monitored over the past 50 years.

“Kelp forests are cold-water, fast-growing species that can apparently withstand many types of environmental disturbances,” said Mark Novak, an assistant professor of integrative biology in the College of Science at Oregon State University, co-author of the study, and an organizer of the international group at the National Center for Ecological Analysis and Synthesis that conducted this research.

“The really surprising thing in this study was how much region-to-region variation we found, which is quite different from many other ecosystems. Thus, despite global threats like climate change and ocean acidification, the battle to protect our kelp forests of the future may best be fought locally – in the U.S., by states, counties, even individual cities and towns.”

These forests can grow fast, tall, and are highly resilient – but also are often on the coastal front line in exposure to pollution, sedimentation, invasive species, fishing, recreation and harvesting. Even though “they have some of the fastest growth rates of any primary producer on the planet,” the researchers wrote, there are limits to what they can take.

In their study the scientists concluded that of the kelp ecosystems that have been studied, 38 percent are in decline; 27 percent are increasing; and 35 percent show no detectable change. On a global scale, they are declining at 1.8 percent per year.

Where kelp resilience is eroding and leading to declines in abundance, impacts to ecosystem health and services can be far-reaching, the researchers wrote in their report.

This research was supported by the National Science Foundation, the University of California/Santa Barbara, and the state of California.

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Mark Novak, 541-737-3610

mark.novak@oregonstate.edu

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Kelp Forest
Kelp forests

New ‘optofluidic’ technology taps power of diatoms to improve sensor performance

CORVALLIS, Ore. – Researchers at Oregon State University have combined one of nature’s tiny miracles, the diatom, with a version of inkjet printing and optical sensing to create an exceptional sensing device that may be up to 10 million times more sensitive than some other commonly used approaches.

A patent has been approved on the new “optofluidic” technology, and the findings published in the journal Nanoscale.

When implemented in working devices, this approach might improve biomedical sensing of cancer biomarkers; be used for extraordinarily precise forensics work; save the lives of military personnel in combat situations; detect illegal drugs; or help tell whether organic food is really pesticide free or not.

The enormous sensitivity and low cost of the technology may have endless applications, researchers say, ranging from health monitoring to environmental protection, biological experiments and other uses.

“Some existing sensors can detect compounds at levels of one part per billion, which sounds pretty good, but for many purposes that’s not good enough,” said Alan Wang, an OSU assistant professor of electrical engineering in the OSU College of Engineering, and corresponding author on the study.

“With this approach, we can detect some types of compounds at less than one part per trillion, about the level of a single molecule in a small sample. That’s really difficult. Aside from its sensitivity, the technology can also work with ultra-small samples, is fast, and should be very inexpensive to use.”

This system combines advanced optics with a fluidic system to identify compounds. With most conventional systems of this type, fluids must flow over a surface, and this limits the transport of specific molecules you might want to identify, Wang said.

The diatoms in this new technology, however, act as natural “photonic crystals.” They harness the forces of convection against diffusion to help accelerate and concentrate molecules in a space where photons from optical sensors can get trapped, interact with and identify the compound through optical signatures.

“A diatom is a natural, living type of phytoplankton that creates very precise, tiny structures,” Wang said. “When liquids are deposited on it with carefully controlled inkjet devices, the droplets evaporate quickly, but, in the process, carry the molecules of interest to the diatom surface. This is the key to increasing the sensitivity of the photonic measurements.”

The sensor technology, researchers say, can quickly and accurately identify what compounds are present, and approximately how much.

In one demonstration in this research, the scientists tried to identify trinitrotoluene, or TNT, one of the common ingredients in explosive devices – including the hidden mines that have caused numerous injuries and deaths in battle situations. TNT is a chemical with very low volatility, meaning it has limited evaporation, and comparatively few molecules escape that could allow detection. In a hidden bomb, it’s hard to find.

This new technology was one million more times sensitive at identifying TNT than other common approaches, Wang said. A monitor based on this approach, that could be fast and accurate in military situations, may one day help save lives, he said.

Collaborators on the research were from Washington State University, and the research was supported by the National Institutes of Health and the U.S. Department of Defense.

Commercial applications of the technology are already being explored, OSU officials said.

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Alan Wang, 541-737-4247

wang@eecs.oregonstate.edu


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Optofluidic sensor
Optofluidic sensor

Discovery of new bacteria complicates problem with salmon poisoning in dogs

CORVALLIS, Ore. – Researchers at Oregon State University have identified for the first time another bacterium that can cause symptoms similar to “salmon poisoning” in dogs - and may complicate the efforts of Pacific Northwest pet owners to keep their dogs protected and healthy.

The Pacific Northwest, from northern California to central Washington, is the only region of the world in which dogs face this potentially deadly health threat. It’s caused by a complicated life cycle that includes a common freshwater snail that harbors a fluke worm, and the fluke, in turn, carries the bacterium Neorickettsia helminthoeca. The bacterium is the actual cause of salmon poisoning.

The underlying problem is not new. Dogs that died after eating uncooked, infected salmon were first noted in the Astoria Journal in 1814, not long after Lewis and Clark visited the region.

The conventional wisdom, however, has been that dogs are usually immune to salmon poisoning after they have once been infected, treated with antibiotics and recovered – giving pet owners at least some assurance that it’s a problem they no longer need be concerned about.

The new discovery makes it clear the issue is not that simple.

In the infectious process that leads to salmon poisoning, the fluke is released from snails, which then infect salmon and other freshwater fishes. The life cycle is completed when a mammal eats an infected fish – in this case, dogs get sick from eating raw or undercooked salmon. The possible occurrence of “salmon poisoning” is actually dictated by the geographic distribution of the snail.

Another bacterium called “SF agent,” however, has been found for the first time in a salmonid fish anywhere in the world, researchers report in a recent study in Veterinary Parasitology. The fluke host for this bacterium is Stellanchasmus falcatus.

“SF agent can infect dogs that eat salmon or trout, and it can cause a mild fever in dogs and other symptoms that can resemble salmon poisoning,” said Michael Kent, a professor of microbiology in the OSU College of Science and College of Veterinary Medicine, and co-author of the study. “It can also be treated with antibiotics, but may not offer immunity to dogs that could be later exposed to the actual salmon poisoning bacterium. A pet owner might believe their dog is protected, when it isn’t.”

The larval stages of the worm that carries Neorickettsia helminthoeca were first associated with the disease in 1911, and in 1950 the actual bacterium was confirmed as the cause of salmon poisoning. It’s in the same bacterial family as SF agent – meaning pet owners must now understand their dogs may face two related Neorickettsia pathogens – but one causes only a mild illness, while the other can be deadly.

Veterinary doctors, Kent said, routinely have treated animals based on their [mlk1] clinical signs, because the eggs of the fluke may be hard to find in dog feces, and the bacterium is difficult to culture from dog blood. Left untreated, dogs with salmon poisoning can die in a week to 10 days, often from severe hemorrhaging and internal ruptures. The ultimate fatality rate can approach 90 percent of untreated cases.

The bottom line, he said, is that pet owners should not make any assumptions about whether or not their dogs may have immunity to salmon poisoning. Kent said he has received several reports from local veterinarians documenting dogs contracting salmon poisoning more than once.

With the new awareness that different bacteria can cause similar initial symptoms, pet owners should know that dogs displaying such symptoms may or may not have a serious health problem.

The fluke worm, but not the bacterium, can also infect humans.  Humans do not contract salmon poisoning, but may develop a relatively mild gastrointestinal illness. Either freezing or cooking infected fish will kill the worms.

This research was supported by the National Institutes of Health and done in collaboration with researchers from the University of North Dakota, Georgia Southern University, and the Woodburn Veterinary Clinic in Woodburn, Ore.


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Michael Kent, 541-737-8652

michael.kent@oregonstate.edu

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Salmon poisoning of dogs
Dogs at play

Mental health spending nets return by reducing jail population

CORVALLIS, Ore. – Each dollar a state spends on mental health care cuts roughly 25 cents off its jail expenditures by reducing its inmate population, a new study shows.

The findings, published in the journal Social Science & Medicine, suggest that 35 of the 44 states analyzed could reduce jail populations by spending more on public inpatient mental health care while maintaining their current level of community mental health care. The U.S. average cost for housing a jail inmate is $60 a day.

Jangho Yoon and Jeff Luck, professors in the College of Public Health and Human Sciences at Oregon State University, looked at data from 44 states plus the District of Columbia over a nine-year period, examining the relationships among government spending on community mental health care, spending on inpatient mental health care and jail population.

Community care, which traces its roots to President Kennedy’s signing of the 1963 Community Mental Health Act, evolved as an alternative to institutionalization. It involves a mix of public and private organizations that work with patients as they continue to live in their home city or town. Inpatient care, meanwhile, refers to facilities such as state mental hospitals.

People with mental illness make up a significant portion of jail populations, and many of those inmates could be safely supervised and more effectively treated somewhere other than jail. Effects of the treatment could include being less likely to behave in a way that results in being jailed.

While emphasizing their work does not support cutting spending for community mental health services, the researchers note that from a strict intersystem return on investment perspective, inpatient spending has a greater effect on lowering jail spending.

“Everyone has a right to treatment in the most safe and humane environment possible,” Yoon said. “Our findings show that if per-capita public inpatient mental health spending is increased by 10 percent, the jail population shrinks by 1.5 percent. The positive spill-over effect of increased inpatient spending is greater at lower levels of community spending, which shows the principle of diminishing marginal return applies here.”

Likewise, Yoon noted, the positive spill-over effect of community spending is greater at lower levels of inpatient spending, “although a change in per-capita community mental health expenditure on average does not have a statistically significant effect on jail population size.

“An increase in public inpatient spending would decrease jail populations in the 35 states that spend less than $134 per capita on community mental health care, and the District of Columbia, which also spends less than $134 per capita,” Yoon said.

Below that $134-per-capita level, he added, “the associated benefit-cost ratio is 26 cents, which indicates a positive intersystem return on investment of 26 percent. Every dollar spent annually on inpatient mental health by a state would yield a positive spillover benefit of a quarter dollar for the jail system by reducing the number of inmates.”

The research showed that spending on community mental health care loses its ability to reduce jail populations once spending levels rise to greater than $16 per capita. Forty-two of the 44 states analyzed, as well as the District of Columbia, are below that threshold; thus, those states’ jail populations would likely decline with an increase in community mental health spending while maintaining the current level of inpatient funding.

“Although there is significant cross-state variation, the ROI overall is much greater for inpatient spending,” Yoon said. “Our results suggest that states whose policy aim is to reduce jail populations direct increased spending toward inpatient mental health rather than outpatient-based community mental health.”

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Steve Lundeberg, 541-737-4039

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Mental health spending

Glucose-monitoring contact lens would feature transparent sensor

CORVALLIS, Ore. – Type 1 diabetes patients may one day be able to monitor their blood glucose levels and even control their insulin infusions via a transparent sensor on a contact lens, a new Oregon State University study suggests.

The sensor uses a nanostructured transistor – specifically an amorphous indium gallium oxide field effect transistor, or IGZO FET – that can detect subtle glucose changes in physiological buffer solutions, such as the tear fluid in eyes.

Type 1 diabetes, formerly known as juvenile diabetes, can lead to serious health complications unless glucose levels are carefully controlled. Problems can include retinopathy, blindness, neuropathy, kidney and cardiac disease.

Researchers in the OSU College of Engineering say sensors they fabricated using the IGZO FET will be able to transmit real-time glucose information to a wearable pump that delivers the hormones needed to regulate blood sugar: insulin and glucagon.

The sensor and pump would, in effect, act as an artificial pancreas.

“We have fully transparent sensors that are working,” said Greg Herman, an OSU professor of chemical engineering and corresponding author on this study. “What we want to do next is fully develop the communication aspect, and we want to use the entire contact lens as real estate for sensing and communications electronics.

“We can integrate an array of sensors into the lens and also test for other things: stress hormones, uric acid, pressure sensing for glaucoma, and things like that. We can monitor many compounds in tears – and since the sensor is transparent, it doesn’t obstruct vision; more real estate is available for sensing on the contact lens.”

The FET’s closely packed, hexagonal, nanostructured network resulted from complimentary patterning techniques that have the potential for low-cost fabrication. Those techniques include colloidal nanolithography and electrohydrodynamic printing, or e-jet, which is somewhat like an inkjet printer that creates much finer drop sizes and works with biological materials instead of ink.

The findings by postdoctoral scholar Xiaosong Du, visiting scholar Yajuan Li and,Herman were recently published online in the journal Nanoscale. The Juvenile Diabetes Research Foundation provided primary funding for the research.

Google has been working on a glucose-monitoring contact lens but its version is not fully transparent.

“It’s an amperometric sensor and you can see the chips -- that means it has to be off to the side of the contact lens,” Herman said. “Another issue is the signal is dependent on the size of the sensor and you can only make it so small or you won’t be able to get a usable signal. With an FET sensor, you can actually make it smaller and enhance the output signal by doing this.”

This research builds on earlier work by Herman and other OSU engineers that developed a glucose sensor that could be wrapped around a catheter, such as one used to administer insulin from a pump.

“A lot of type 1 diabetics don’t wear a pump,” Herman said. “Many are still managing with blood droplets on glucose strips, then using self-injection. Even with the contact lens, someone could still manage their diabetes with self-injection. The sensor could communicate with your phone to warn you if your glucose was high or low.”

The transparent FET sensors, Herman said, might ultimately be used for cancer detection, by sensing characteristic biomarkers of cancer risk. Their high sensitivity could also measure things such as pulse rate, oxygen levels, and other aspects of health monitoring that require precise control.

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Steve Lundeberg, 541-737-4039

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3D AFM

Transistor's nanostructure

Impulsive personality linked to greater risk for early onset of meth use

CORVALLIS, Ore. – Methamphetamine users who described themselves as impulsive were more likely to have started taking the drug at an earlier age, a study of more than 150 users showed.

Both attentional and motor impulsivity were linked to early meth use, even when accounting for total years of use. On average, people who use methamphetamine start at about age 22.

“It’s really unclear if impulsivity is a contributor or a consequence of early methamphetamine use; I think it’s both,” said Anita Cservenka, an assistant professor in the School of Psychological Science at Oregon State University and co-author of the recent study in the journal Addictive Behaviors.

“Impulsivity is highly related to the number of years of using methamphetamine, specifically in men. Our findings suggest that impulsivity likely both contributes to using this substance and increases as a result of using it.”

The National Institute on Drug Abuse funded the study, and Lara A. Ray of UCLA was the corresponding author. The researchers looked at 157 meth users’ scores on the Barratt Impulsiveness Scale, a widely used self-reporting measure of impulsive personality traits.

Those in the study sample were between 18 and 50 years old, reported using meth in the last 30 days, and reported not using any other substances other than alcohol, tobacco or marijuana. The subjects were free of major mental or physical health problems and were not seeking treatment for their meth use.

The Barratt Impulsiveness Scale is broken into multiple types of impulsivity, some of which include attentional and motor impulsivity. Attentional impulsiveness has been defined as an inability to focus attention or concentrate. Motor impulsiveness refers to a tendency to act on whims.

About 1 percent of 12th-graders report having used meth at least once, and more than 6 percent of people 26 and older have used meth in their lifetime.

“One possibility is that meth users are self-medicating,” Cservenka said. “If they have difficulty paying attention, they may try to use meth to perhaps improve their attentional ability, as amphetamines are clinically prescribed for this purpose.”

Illicitly manufactured and distributed, methamphetamine is a toxic, strong, highly addictive central nervous system stimulant. Using it can cause disturbed sleep patterns, hyperactivity, nausea, delusions, aggressiveness, irritability, confusion, anxiety and hallucinations.

“Methamphetamine use is such a big burden on the individual and also at the societal level,” Cservenka said. “We pay a lot for users’ health care because meth use impairs both psychosocial function and physical health. These results suggest that if we find individuals during adolescence who show elevated symptoms of impulsivity or a lack of inhibitory control, they may be individuals we want to target for early intervention.

Cservenka says longitudinal studies – tracking subjects over time – are needed to better determine if impulsivity is a trigger for early meth use.

“Because this was a cross-sectional study, we can’t say that impulsivity led to meth use,” she said. “We can only suggest that perhaps impulsivity might be a trait that individuals should pay attention to in at-risk youth, especially when it comes to late adolescence or young adulthood, when most meth use is initiated.

“We can only see the complete picture if we track adolescents at an early age and then follow them into young adulthood to understand what risk factors contribute to starting using a substance like meth. Impulsivity may be one of them, but there are likely a number of other risk factors.

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Steve Lundeberg, 541-737-4039

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anita cservenka

Anita Cservenka

Excess wildfire, cheatgrass affecting sage-grouse; targeted actions needed

BEND, Ore. – Larger, more frequent wildfires across the Great Basin have contributed significantly to a decline in greater sage-grouse, according to a new study that also indicates that if this trend continues unabated, it could reduce the population of this indicator species to 43 percent of its present numbers.

The culprit, researchers say, is the influx of exotic annual grasses such as cheatgrass that establish after wildfire removes the native plant community, including sagebrush, the plant upon which sage-grouse are dependent for survival.

Results of the study are being published this week in the journal Proceedings of the National Academy of Sciences.

The Great Basin of North America is a vast landscape that is larger than 75 percent of the countries worldwide. It is comprised primarily of a “sagebrush sea” that is threatened by this cycle of wildfire and cheatgrass, according to Christian Hagen, a senior research associate at Oregon State University and a co-author on the study.

“Our modeling indicates that there are long-lasting effects from wildfire that negate increases in sage-grouse population growth that typically occur after years of higher precipitation,” said Hagen, a researcher in OSU’s Department of Fisheries and Wildlife. “So even when we have a good precipitation year in the Great Basin, the sage-grouse don’t recover as they once did because the habitat to support them has been lost to cheatgrass.”

The study area encompassed the hydrographic and vegetation boundaries of the Great Basin and included parts of six western states: Nevada (43 percent of the area), Utah (17 percent), Idaho (16 percent), Oregon (14 percent), California (10 percent) and Wyoming (less than 1 percent).

“Wildfire is increasing in the region because the invading cheatgrass is much more prone to burn and re-establishes orders of magnitude quicker than the native sagebrush,” Hagen said. “That isn’t necessarily news – Aldo Leopold recognized that more than a half-century ago. But the impact on an indicator species like the sage-grouse had not been so clearly documented.”

Sagebrush has slow growth rates and does not re-sprout after wildfires; it must re-establish from the seed bank. This delay in succession opens the door for cheatgrass to establish. The researchers say that understanding “R&R” – resilience to wildfire and resistance to cheatgrass – is key to focusing the right land management practices in the right places.

Cheatgrass hails from warmer regions of Eurasia and generally does not persist in relatively cold and moist climates. Colder, moist soils tend to be the most productive ecological sites in the Great Basin, and these sites promote the growth of perennial bunch grasses, native forbs and shrubs – plants that tend to be more resilient to fire, and resistant to invasive grasses.

These also are some of the most productive sites for the sage-grouse. The sage-grouse is a large gallinaceous, or ground-feeding, bird that can be an indicator for ecological health in sagebrush ecosystems because it requires distinct ecological states to meet its diverse life-history needs. Thus, the population dynamics of the species are considered an ideal metric for assessing disturbances to sagebrush disturbance.

The sage-grouse has been considered several times for protection under the Endangered Species Act, the most recent of which triggered massive changes to land management policy on millions of acres of public land.

The cycle of habitat decline is linked to the introduction of cheatgrass to the ecosystem, the researchers say. Land management practices led to a burning regime as often as every 2-3 years, which allowed fast-growing cheatgrass to establish at the expense of slow-growing sagebrush.

“If you can imagine an area the size of a football field infested with cheatgrass, but surrounded by native vegetation,” Hagen said. “If a lightning strike sets the cheatgrass on fire, it likely will consume some of the native vegetation and the burned area doubles or triples, and by next year the cheatgrass infestation has spread.

“It’s a classic positive feedback loop that promotes cheatgrass and becomes a negative situation for native plants – and ultimately, for sage-grouse.”

The key to reversing this decline, the researchers say, may be to further enhance fire prevention and suppression effectiveness in targeted areas of intact sagebrush that have the highest densities of breeding sage-grouse. The study shows that 90 percent of sage-grouse are concentrated on less than 10 percent of the Great Basin.

“Our study illustrates a path toward stabilizing sage-grouse populations through highly focused wildfire management,” Hagen said. “New federal wildland fire policies and priorities in sagebrush steppe, combined with improved collaboration with rural communities through rangeland fire protection associations, greatly increases the odds of curbing population declines due to fire.”

The study was led by Peter S. Coates of the U.S. Geological Survey.

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Christian Hagen, 541-410-0238, Christian.hagen@oregonstate.edu

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This photo of a greater sage-grouse is available at: https://flic.kr/p/Nw6T9S

(Photo by Nick Myatt, ODFW)

Boosting levels of known antioxidant may help resist age-related decline

CORVALLIS, Ore. – Researchers at Oregon State University have found that a specific detoxification compound, glutathione, helps resist the toxic stresses of everyday life – but its levels decline with age and this sets the stage for a wide range of age-related health problems.

A new study, published in the journal Redox Biology, also highlighted a compound – N-acetyl-cysteine, or NAC – that is already used in high doses in medical detoxification emergencies. But the researchers said that at much lower levels NAC might help maintain glutathione levels and prevent the routine metabolic declines associated with aging.

In that context, the research not only offers some profound insights into why the health of animals declines with age, but specifically points to a compound that might help prevent some of the toxic processes involved.

Decline of these detoxification pathways, scientists say, are causally linked to cardiovascular disease, diabetes and cancer, some of the primary causes of death in the developed world.

“We’ve known for some time of the importance of glutathione as a strong antioxidant,” said Tory Hagen, lead author on the research and the Helen P. Rumbel Professor for Health Aging Research in the Linus Pauling Institute at OSU.

“What this study pointed out was the way that cells from younger animals are far more resistant to stress than those from older animals,” said Hagen, also a professor of biochemistry in the OSU College of Science. “In young animal cells, stress doesn’t cause such a rapid loss of glutathione. The cells from older animals, on the other hand, were quickly depleted of glutathione and died twice as fast when subjected to stress.

“But pretreatment with NAC increased glutathione levels in the older cells and largely helped offset that level of cell death.”

Glutathione, Hagen said, is such an important antioxidant that its existence appears to date back as far as oxygen-dependent, or aerobic life itself – about 1.5 billion years. It’s a principal compound to detoxify environmental stresses, air pollutants, heavy metals, pharmaceuticals and many other toxic insults.

In this study, scientists tried to identify the resistance to toxins of young cells, compared to those of older cells. They used a toxic compound called menadione to stress the cells, and in the face of that stress the younger cells lost significantly less of their glutathione than older cells did. The glutathione levels of young rat cells never decreased to less than 35 percent of its initial level, whereas in older rat cells glutathione levels plummeted to 10 percent of their original level.

NAC, the researchers said, is known to boost the metabolic function of glutathione and increase its rate of synthesis. It’s already used in emergency medicine to help patients in a toxic crisis, such as ingestion of poisonous levels of heavy metals. It’s believed to be a very safe compound to use even at extremely high levels – and the scientists are hypothesizing that it might have significant value at much lower doses to maintain glutathione levels and improve health.

“I’m optimistic there could be a role for this compound in preventing the increased toxicity we face with aging, as our abilities to deal with toxins decline,” Hagen said. “We might be able to improve the metabolic resilience that we’re naturally losing with age.”

Also of interest, Hagen said, is the wide range of apparent detoxification potential offered by glutathione. Higher levels of it – boosted by NAC – might help reduce the toxicity of some prescription drugs, cancer chemotherapies, and treat other health issues.

“Using NAC as a prophylactic, instead of an intervention, may allow glutathione levels to be maintained for detoxification in older adults,” the researchers wrote in their conclusion.

This research was supported by the National Institutes of Health, the National Science Foundation and the Medical Research Foundation of Oregon.

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Tory Hagen, 541-737-5083

tory.hagen@oregonstate.edu

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Glutathione
Structure of glutathione

System changes improve prenatal care for Oregon Medicaid beneficiaries

CORVALLIS, Ore. – Oregon’s 2012 shift to an incentivized, accountable-care system for Medicaid beneficiaries led to positive changes for expectant mothers and their babies, research at Oregon State University shows.

The research found Oregon’s implementation of “coordinated care organizations” resulted in more expectant moms starting prenatal care on time. It also showed a small narrowing of the gap in prenatal care quality between Medicaid beneficiaries and those with private insurance.

Late-starting or inadequate prenatal care is connected to a number of adverse outcomes, including low birth weight, preterm birth, stillbirth and infant death.

“Improving women’s access to adequate prenatal care — typically defined as initiating prenatal care within the first trimester of pregnancy and adhering to recommended prenatal care visits — can facilitate the identification and subsequent management of high-risk pregnancies,” said Ifeoma Muoto, who was a doctoral student working with Associate Professor Jeff Luck in OSU’s College of Public Health and Human Sciences at the time of the study.

Muoto, now an administrative fellow at Kaiser Permanente Southern California, looked at more than a half-million pregnancies in a six-year period in Oregon and Washington, including 2013, the first year for Oregon’s 16 coordinated care organizations, or CCOs. Washington served as the control group.

The study’s objective was to assess the impact of the CCOs on the quality of prenatal care among Oregon Medicaid beneficiaries. The results were recently published in the journal Health Affairs.

The study also showed a narrowing, albeit a small one, of the gap in prenatal care quality between Medicaid beneficiaries and those with private insurance.

“Prenatal care was one of the performance measures for the new CCOs and you can’t disentangle the measures from the CCO startup, but it’s promising that just in the first year there were significant improvements,” Luck said.

Luck is a member of the Oregon Health Authority’s Metrics and Scoring Committee, which is charged with determining whether CCOs are “effectively and adequately improving care, making quality care accessible, eliminating health disparities, and controlling costs.”

The committee picked which types of care would be incentivized – meaning which types of care would serve as benchmarks that CCOs could meet to earn more funding. Other types of care that are incentivized include chronic diseases, substance abuse and mental health.

“We hypothesized that the CCOs would have the benefit for prenatal care that they did,” Luck said. “This is early evidence that some of the care delivery improvements we hoped for really are occurring.”

The federal Office of Disease Prevention and Health Promotion’s HealthyPeople 2020 initiative includes increasing the percentage of women who initiate prenatal care in the first trimester of pregnancy from 70.8 percent to 77.9 percent.

In Oregon, the rate of pregnant Medicaid beneficiaries starting care in the first trimester climbed from 73.1 percent in the pre-CCO period to 77.3 percent in the first year of the CCOs. In Washington, the rate for women on Medicaid rose from 71.7 to 73.6 percent, a smaller percentage increase than Oregon’s. Although women covered by private insurance in Oregon had higher levels of timely prenatal care initiation and prenatal care adequacy, the rates among that group were stable during the time period studied.

For prenatal care adequacy – initiating care in the first trimester and having at least nine doctor visits during a pregnancy – there was an increase from 65.9 to 70.5 percent for Medicaid-covered women in Oregon. That increase, though, was not statistically significant relative to the increase observed among Medicaid-covered women in Washington, where the improvement was 58.5 to 62.2 percent.

Luck noted the results indicated care adequacy was “going in the right direction but wasn’t yet statistically significant.”

“It’s possible when we have more years of data we’ll be able to make a more precise estimate,” he said. “We also have a parallel project funded by the Centers for Disease Control using a larger pool of data from Oregon – not only birth certificates but Medicaid claims data, claims data from the Oregon Health Plan, which is Oregon’s Medicaid program, and hospital discharge data.”

Luck noted the research is particularly important given the percentage of births to Medicaid beneficiaries. Medicaid births made up roughly 45 percent of total U.S. births even prior to an expansion of the Medicaid program that began in January 2014.

Media Contact: 

Steve Lundeberg, 541-737-4039

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Prenatal care

Expectant mother