OREGON STATE UNIVERSITY

college of veterinary medicine

Immune system uses gut bacteria to control glucose metabolism

CORVALLIS, Ore. – Researchers at Oregon State University and other institutions have discovered an important link between the immune system, gut bacteria and glucose metabolism – a “cross-talk” and interaction that can lead to type 2 diabetes and metabolic syndrome when not functioning correctly.

The findings, published today in Nature Communications, are one example of how different mammalian systems can affect each other in ways not previously understood.

A better understanding of these systems, researchers say, may lead to new probiotic approaches to diabetes and other diseases.

The research also shows the general importance of proper bacterial functions in the gut and the role of one bacteria in particular – Akkermansia muciniphila -  in helping to regulate glucose metabolism.

This bacteria’s function is so important, scientists say, that it has been conserved through millions of years of evolution to perform a similar function in both mice and humans.

“We’re discovering that in biology there are multiple connections and communications, what we call cross-talk, that are very important in ways we’re just beginning to understand,” said Dr. Natalia Shulzhenko, an assistant professor in the OSU College of Veterinary Medicine, and one of the corresponding authors on this study.

“It’s being made clear by a number of studies that our immune system, in particular, is closely linked to other metabolic functions in ways we never realized. This is still unconventional thinking, and it’s being described as a new field called immunometabolism. Through the process of evolution, mammals, including humans, have developed functional systems that communicate with each other, and microbes are an essential part of that process.”

It had been previously observed that an immune mediator - one type of interferon, or signaling protein called IFN-y – can affect the proper function of glucose metabolism. IFN-y helps fight several pathogens and infections, but a decrease in its levels can lead to improvement in glucose metabolism. However, this actual process has not been understood.

“Before this, no one had a clue exactly how IFN-y affected glucose tolerance,” said Andrey Morgun, an assistant professor in the OSU College of Pharmacy and also a corresponding author on the study. “The involvement of microbes had not really been considered. But with the help of a statistical model and an approach we call a transkingdom network, we were able to pinpoint some likely bacterial candidates.”

The bacteria A. muciniphila, was found to play a critical role in this communication process – in their study, the scientists called it a “missing link.” Research showed that mice specially bred with reduced levels of IFN-y had higher levels of A. muciniphila, and significantly improved glucose tolerance. When IFN-y levels increased, A. muciniphila levels declined, and glucose tolerance was reduced.

Similar observations were also made in humans. It’s been observed, for instance, that athletes who are extremely fit have high levels of the gut bacteria A. muciniphila, which is a mucus-degrading bacteria. The research makes clear that two systems once believed to be functionally separate – immunity and glucose metabolism – are, in fact, closely linked, and the bridge can be provided by gut bacteria.

There’s probably more than one bacteria involved in this process of communication and metabolic control, researchers said. The gut harbors literally thousands of microbes that appear to function almost as a metabolically active organ, emphasizing the critical importance of gut bacterial health.

Bacteria-mediated communication, of course, is just one part of complex human systems – issues such as proper diet, exercise, and appropriate weight control are all still important, the researchers said.

This research was supported by the National Institutes of Health. Other collaborating researchers were from the University of Sao Paulo in Brazil, University of North Carolina, National Institute of Allergy and Infectious Diseases, and Duke University Medical Center. Co-first authors were Renee Greer of the OSU College of Veterinary Medicine and Xiaoxi Dong of the OSU College of Pharmacy.

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Dr. Natalia Shulzhenko, 541-737-1051

natalia.shulzhenko@oregonstate.edu

OSU trustees approve expanding veterinary teaching hospital, renovating Magruder Hall

BEND, Ore. – The Oregon State University Board of Trustees Friday approved the renovation of Magruder Hall to allow OSU’s College of Veterinary Medicine to increase its enrollment and expand the college’s small animal veterinary teaching hospital.

The trustees’ meetings were held on the new OSU-Cascades campus, which opened in September as the state’s first new public university in 50 years.

The $10 million project to expand Magruder Hall will be added to Oregon State’s overall $258 million 2015-17 capital plan.

Plans include a 6,000-square-foot expansion to double the size of the College of Veterinary Medicine’s small animal teaching hospital that presently serves nearly 40 cases per day and has from 45 to 70 people working in it. Over the past four years, the hospital’s case load has increased 15 percent annually. Renovation of Magruder Hall and the expansion of the hospital will enable the college to grow its enrollment by 16 veterinary medicine students.

“This project will directly improve the educational experience of veterinary students by providing improved instructional space, including laboratories for learning, such as anatomy and surgery skills,” said Sue Tornquist, dean of OSU’s College of Veterinary Medicine. “With this project, graduating veterinarians will have training in new and advanced treatment procedures, such as radiation oncology.”

Tornquist said the college will use philanthropic gifts, college funds and tuition revenues from the projected additional student enrollment to pay for the project.

In other business:

 

  • The board approved its annual performance review of OSU President Ed Ray for the past fiscal year;
  • Established guidelines for future presidential searches and selection processes;
  • Adopted a board calendar to guide the work of the board over the next year;
  • Adopted amendments to the university’s investment policy. The amendments enable the university’s vice president for finance and administration to provide quarterly reports regarding the investment of university assets to the board’s Finance and Administration Committee instead of the full board;
  • Approved the termination of a Master of Agriculture program. This master’s program is experiencing low student participation with currently only five students enrolled. The College of Agricultural Sciences plans to develop a new degree program that addresses current and future agricultural issues.

 

Board Chair Pat Reser said that Ray’s performance assessment included input from university, community, Oregon and national higher education constituents. She said Ray is considered a trusted, energetic and strategic leader. “We compliment President Ray on the progress the university has made over the past year and support his focused and continued outstanding leadership of Oregon State University,” Reser said.

The board deferred until its January 2017 meeting consideration of a change in the university’s in the Public University Fund that would have divested university funds from current fossil fuel-related securities and would restrict future investments in fossil fuel-related securities. Oregon State and five other Oregon public universities make up the Public University Fund, which is managed by the Oregon Treasurer’s office. Presently, approximately 1.7 percent of that fund is invested in fossil fuel-related securities.

In deferring action until January, trustees directed university administrators to develop a draft framework that the board could utilize in evaluating decisions about divestiture or other future financial matters.

During the meeting, trustees heard reports from President Ray; officers of the OSU Faculty Senate, the Associated Students of Oregon State University and the Associated Students of Cascades Campus; the chair of the state’s Higher Education Coordinating Commission; and the OSU Foundation regarding the foundation’s strategic plan.

During public comment provided the board, a graduate student in Oregon State’s College of Education, asked trustees to reverse the university’s decision to build OSU’s marine studies building on the Hatfield Marine Sciences Center campus.

On Wednesday, trustees held a public session retreat to learn more about the university’s student success initiative; the cost structure of the university; and future revenue and cost management opportunities.

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Fat, sugar cause bacterial changes that may relate to loss of cognitive function

CORVALLIS, Ore. – A study at Oregon State University indicates that both a high-fat and a high-sugar diet, compared to a normal diet, cause changes in gut bacteria that appear related to a significant loss of “cognitive flexibility,” or the power to adapt and adjust to changing situations.

This effect was most serious on the high-sugar diet, which also showed an impairment of early learning for both long-term and short-term memory.

The findings are consistent with some other studies about the impact of fat and sugar on cognitive function and behavior, and suggest that some of these problems may be linked to alteration of the microbiome – a complex mixture in the digestive system of about 100 trillion microorganisms.

The research was done with laboratory mice that consumed different diets and then faced a variety of tests, such as water maze testing, to monitor changes in their mental and physical function, and associated impacts on various types of bacteria. The findings were published in the journal Neuroscience, in work supported by the Microbiology Foundation and the National Science Foundation.

“It’s increasingly clear that our gut bacteria, or microbiota, can communicate with the human brain,” said Kathy Magnusson, a professor in the OSU College of Veterinary Medicine and principal investigator with the Linus Pauling Institute.

“Bacteria can release compounds that act as neurotransmitters, stimulate sensory nerves or the immune system, and affect a wide range of biological functions,” she said. “We’re not sure just what messages are being sent, but we are tracking down the pathways and the effects.”

Mice have proven to be a particularly good model for studies relevant to humans, Magnusson said, on such topics as aging, spatial memory, obesity and other issues.

In this research, after just four weeks on a high-fat or a high-sugar diet, the performance of mice on various tests of mental and physical function began to drop, compared to animals on a normal diet. One of the most pronounced changes was in what researchers call cognitive flexibility.

“The impairment of cognitive flexibility in this study was pretty strong,” Magnusson said. “Think about driving home on a route that’s very familiar to you, something you’re used to doing. Then one day that road is closed and you suddenly have to find a new way home.”

A person with high levels of cognitive flexibility would immediately adapt to the change, determine the next best route home, and remember to use the same route the following morning, all with little problem. With impaired flexibility, it might be a long, slow, and stressful way home.

This study was done with young animals, Magnusson said, which ordinarily would have a healthier biological system that’s better able to resist pathological influences from their microbiota. The findings might be even more pronounced with older animals or humans with compromised intestinal systems, she said.

What’s often referred to as the “Western diet,” or foods that are high in fat, sugars and simple carbohydrates, has been linked to a range of chronic illnesses in the United States, including the obesity epidemic and an increased incidence of Alzheimer’s disease.

“We’ve known for a while that too much fat and sugar are not good for you,” Magnusson said. “This work suggests that fat and sugar are altering your healthy bacterial systems, and that’s one of the reasons those foods aren’t good for you. It’s not just the food that could be influencing your brain, but an interaction between the food and microbial changes.”

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Kathy Magnusson, 541-737-6923

More horses found with Equine Herpes Virus, including most serious form

CORVALLIS, Ore. – Three more cases have been found in Oregon of horses infected with Equine Herpes Virus 1, or EHV-1, and one animal has the most serious “neurotropic” form of the virus that is far more likely to cause serious, sometimes permanent neurological damage.

An initial case of EHV-1 reported last week, and also being treated in isolation at OSU, only had the more common wild strain of the virus. That horse did show neurologic symptoms, although animals with that strain of EHV-1 more often have a disease that causes respiratory infection or abortion in pregnant mares.

Two more cases have been identified of horses with the wild strain, that are not showing signs of neurologic disease, and they are being treated at their home stables in Polk County. Both forms of EHV-1 are highly contagious to horses, but not transmissible to people.

However, a fourth case has been confirmed with the neurotropic form of EHV-1, veterinary experts say, which increases the seriousness of the current outbreak, and makes it increasingly important that horse owners in Oregon practice strong biosecurity management of their animals.

“About 80 percent of the horses who develop neurologic problems from EHV-1 have the neurotropic form of the virus,” said John Schlipf, a large animal internal medicine specialist with the OSU College of Veterinary Medicine. “It’s a significantly more serious concern. The disease can be fatal, or it can cause lasting neurologic damage that leaves the animal with a permanently reduced level of function.”

The most recent case was brought to OSU’s Lois Bates Acheson Veterinary Teaching Hospital from the Salem area. Both cases are being treated in isolation, and all OSU veterinary teaching hospital facilities are open for business as usual.

The initial case last week was in a horse housed in Marion County that had recently attended events at the Linn County Fairgrounds in Albany on April 16-19. Prior to the development of clinical signs in the initial case and institution of the quarantine, horses housed with the initial case had attended an event at the Oregon Horse Center in Eugene on April 25-26. The newest case was not at the Linn County event, Schlipf said, but had been in contact with other horses that attended.

Since there’s a 10-14 day incubation period for this virus, Schlipf said, it is possible that more horses will be found to be infected. Owners of horses that may be at risk are encouraged to monitor their animals closely for a fever and any signs of respiratory or neurologic disease. More information about the virus and biosecurity recommendations is available online at http://bit.ly/1GNttiS

Early clinical signs of the neurologic form of EHV-1 often begin with the hind limbs and include:

  • Uncoordinated, stumbling movements;
  • An unusual gait;
  • A weak tail tone;
  • Difficulty urinating, and dribbling of urine;
  • Nasal discharge, frequently accompanied by a fever.

The Oregon Department of Agriculture recommends that horses that attended the Albany or Eugene events avoid contact with other horses and have their temperatures monitored twice daily. Temperatures over 101.5 degrees may indicate illness.

Horses with these signs should be isolated from other animals, and owners should contact their veterinarians immediately. EHV-1 can also affect alpacas and llamas, Schlipf said.

“We must reiterate the need for horse owners to practice biosecurity,” Schlipf said. “People handling horses should wash their hands and clothing to reduce spread of a virus. Animals should not share tack, and horses that have traveled or mingled with other animals should be segregated.

“All of these steps can help, and are especially important right now. It may be a while yet before we are out of the woods with this outbreak.”

 

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John Schlipf, 541-737-6962

Faster method to spay cats found to be safe, effective

PORTLAND, Ore. – A new type of procedure to spay female cats has been shown to be safe, effective, and saves a little bit of time – which can be important in some high-volume programs such as those operated by animal shelters.

A study on the procedure has been published in the Journal of Feline Medicine and Surgery, by Kirk Miller, a clinical instructor with the College of Veterinary Medicine at Oregon State University, and practicing veterinarian with the Oregon Humane Society in Portland.

It found that a procedure called a “pedicle tie” is effective at stopping blood flow through two vessels that that go to a cat’s ovary, a preliminary step to removing the ovary and uterus. It’s essentially tying the vessels in a knot – and works just as well, and is about 30 percent faster, than a procedure used for decades that required multiple ligatures to accomplish the same purpose.

There had been no prior study on this approach, and some concern it might cause additional bleeding. But in a survey of 2,136 kittens and adult cats that were neutered using the new technique, it was found to safe with no significant increase in hemorrhagic complications, and slightly reduced the time the animal needed to be under anesthesia.

And, for an average procedure, it saves a couple of minutes out of an overall operation that can take from six to 20 minutes, depending on the skill and experience of the practitioner.

“Saving two minutes may not sound like much, but when you do thousands of these procedures every year, like we do, it can add up in savings of both time and money,” Miller said. “Over the course of a year this may free up about two weeks of time for both the surgeon and anesthetist. That increased efficiency means we can serve more animals, provide the care they need and make them eligible to find new homes.”

The procedure can be taught fairly easily and expertise in it gained within a week or two, Miller said. With its safety and efficacy now verified, it’s anticipated that the procedure may soon be used much more broadly, he said.

Aggressive spay and neuter programs are needed to help address broader concerns about unwanted and homeless companion animals. The American Society for Prevention to Cruelty to Animals estimates there may be as many as 70 million stray cats in the United States. Neutering of dogs and cats helps to address this critical problem, while improving both their behavior and their health.

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Unwanted impact of antibiotics broader, more complex than previously known

CORVALLIS, Ore. – Researchers at Oregon State University have discovered that antibiotics have an impact on the microorganisms that live in an animal’s gut that’s more broad and complex than previously known.

The findings help to better explain some of the damage these medications can do, and set the stage for new ways to study and offset those impacts.

The work was published online in the journal Gut, in research supported by Oregon State University, the Medical Research Foundation of Oregon and the National Institutes of Health.

Researchers have known for some time that antibiotics can have unwanted side effects, especially in disrupting the natural and beneficial microbiota of the gastrointestinal system. But the new study helps explain in much more detail why that is happening, and also suggests that powerful, long-term antibiotic use can have even more far-reaching effects.

Scientists now suspect that antibiotic use, and especially overuse, can have unwanted effects on everything from the immune system to glucose metabolism, food absorption, obesity, stress and behavior.

The issues are rising in importance, since 40 percent of all adults and 70 percent of all children take one or more antibiotics every year, not to mention their use in billions of food animals. Although when used properly antibiotics can help treat life-threatening bacterial infections, more than 10 percent of people who receive the medications can suffer from adverse side effects.

“Just in the past decade a whole new universe has opened up about the far-reaching effects of antibiotic use, and now we’re exploring it,” said Andrey Morgun, an assistant professor in the OSU College of Pharmacy. “The study of microbiota is just exploding. Nothing we find would surprise me at this point.”

This research used a “cocktail” of four antibiotics frequently given to laboratory animals, and studied the impacts.

“Prior to this most people thought antibiotics only depleted microbiota and diminished several important immune functions that take place in the gut,” Morgun said. “Actually that’s only about one-third of the picture. They also kill intestinal epithelium. Destruction of the intestinal epithelium is important because this is the site of nutrient absorption, part of our immune system and it has other biological functions that play a role in human health.”

The research also found that antibiotics and antibiotic-resistant microbes caused significant changes in mitochondrial function, which in turn can lead to more epithelial cell death. That antibiotics have special impacts on the mitochondria of cells is both important and interesting, said Morgun, who was a co-leader of this study with Dr. Natalia Shulzhenko, a researcher in the OSU College of Veterinary Medicine who has an M.D. from Kharkiv Medical University.

Mitochondria plays a major role in cell signaling, growth and energy production, and for good health they need to function properly.

But the relationship of antibiotics to mitochondria may go back a long way. In evolution, mitochondria descended from bacteria, which were some of the earliest life forms, and different bacteria competed with each other for survival. That an antibiotic would still selectively attack the portion of a cell that most closely resembles bacteria may be a throwback to that ingrained sense of competition and the very evolution of life.

Morgun and Schulzhenko’s research group also found that one of the genes affected by antibiotic treatment is critical to the communication between the host and microbe.

“When the host microbe communication system gets out of balance it can lead to a chain of seemingly unrelated problems,” Morgun said.

Digestive dysfunction is near the top of the list, with antibiotic use linked to such issues as diarrhea and ulcerative colitis. But new research is also finding links to obesity, food absorption, depression, immune function, sepsis, allergies and asthma.

This research also developed a new bioinformatics approach named “transkingdom network interrogation” to studying microbiota, which could help further speed the study of any alterations of host microbiota interactions and antibiotic impact. This could aid the search for new probiotics to help offset antibiotic effects, and conceivably lead to systems that would diagnose a person’s microbiome, identify deficiencies and then address them in a precise and individual way. 

Healthy microbiota may also be another way to address growing problems with antibiotic resistance, Morgun said. Instead of trying to kill the “bad” bacteria causing an illness, a healthy and functioning microbiota may be able to outcompete the unwanted microbes and improve immune function.

Collaborators on this research were from the OSU College of Pharmacy; OSU College of Veterinary Medicine; OSU College of Science; the National Cancer Institute; University of British Columbia; University of Maryland School of Medicine; and the National Institutes of Health.

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Andrey Morgun, 541-737-8047

Deworming programs in animal, human populations may have unwanted impacts

CORVALLIS, Ore. – A study of the effects of worming medications on infectious disease in wildlife herds showed an unexpected and alarming result – although it helped reduce individual deaths from a bovine tuberculosis infection, it hugely increased the potential for spread of the disease to other animals.

The findings, from one of the first field studies ever done on this issue, will be published Friday in the journal Science.

They were contrary to expectations based on laboratory studies, and suggest the possibility that broad use of medical treatments such as this can backfire. They may actually increase the problem with diseases they were meant to reduce.

Both in animals and possibly human disease, treatments that aid an individual could come at the expense of a wider spread of disease in the larger community, the research suggested.

“This study indicates that we need to better understand how some medical treatments affect other health issues, in particular infectious disease,” said Anna Jolles, an epidemiologist at Oregon State University and co-author of the study, along with Vanessa Ezenwa at the University of Georgia.

The research, supported by the National Science Foundation, was done with more than 200 animals in two herds of free-ranging African buffalo in Kruger National Park in South Africa. Half were given deworming medication and the others not.

It was known that infection with parasitic helminth worms can decrease the effective immune response against some infectious diseases, in this case bovine tuberculosis, which is common among these animals. Scientists expected the worming medications to save lives while reducing the risk of infection and disease progression.

They found that deworming treatments did improve the survival of animals infected with bovine tuberculosis – in fact, dewormed animals with tuberculosis survived just as well as TB-free animals. However, deworming did not reduce the risk of new infections, and there was a dramatic eight-fold increase in the number of buffalos that an infected animal could potentially infect – a reference to the “R-nought,” or reproductive multiplier that epidemiologists use to predict the potential for spread of infection in a community.

A buffalo with bovine tuberculosis but no worm treatments has, on average, the potential to infect about one other buffalo. This study found that after worm treatment, a buffalo with this disease had the theoretical potential to infect nine other buffalos. This difference was based on the finding that dewormed buffalo with TB can survive for years, whereas the life expectancy of untreated TB-infected buffalo was much shorter.

These issues are of significant concern not just for animal, but also human health, researchers say.

Helminth worm infections are among the most ubiquitous parasites on Earth, infecting 1 billion people and causing significant losses among both livestock and wildlife. Other studies have linked co-infection with these worms to increased risk of death from both tuberculosis and HIV/AIDS in human patients, largely due to their ability to reduce and otherwise skew the natural immune response to both viral and bacterial infection.

This is a larger problem in the developing world, and some major deworming programs in human populations are already in place due to the range of health concerns posed by the parasites. It’s believed that mass deworming programs may reduce overall deaths from some of the major killers in such areas, such as malaria, tuberculosis and HIV infection.

“These results are pretty alarming,” said Jolles, who is a researcher in both the OSU College of Science and College of Veterinary Medicine.

“We expected deworming effects to be all positive, both for individual buffalo, and in terms of reducing disease spread,” Jolles said. “But what we found is positive effects for individual animals, but potentially much faster disease spread at the population level.”

From these results in buffalo, Jolles said, one should not to jump to conclusions about changing deworming treatments in people. But they do raise questions about large, broad-based public deworming programs.

“We must pay attention to health problems that may increase as a result of the program, as well as problems that we are solving,” she said.

The findings also raise questions about aspects of animal agriculture, Jolles said, especially in developing countries. It may be important to match deworming programs with vaccines for infectious disease and other treatments to ensure that the overall health of the herd is protected.

The potential to actually increase spread of a disease following a health treatment such as deworming may vary widely, Jolles said, with different animal species and different infectious diseases.

More studies are urgently needed to address the primary question raised by this research, the scientists said. On a community level, will large-scale deworming treatments alleviate, or will they exacerbate the health impacts of other, sometimes deadly infections?

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Anna Jolles, 541-737-4719

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African buffalo

African buffalo

“Glowing” new nanotechnology guides cancer surgery, also kills remaining malignant cells

CORVALLIS, Ore. – Researchers at Oregon State University have developed a new way to selectively  insert compounds into cancer cells - a system that will help surgeons identify malignant tissues and then, in combination with phototherapy, kill any remaining cancer cells after a tumor is removed.

It’s about as simple as, “If it glows, cut it out.” And if a few malignant cells remain, they’ll soon die.

The findings, published in the journal Nanoscale, have shown remarkable success in laboratory animals. The concept should allow more accurate surgical removal of solid tumors at the same time it eradicates any remaining cancer cells. In laboratory tests, it completely prevented cancer recurrence after phototherapy.

Technology such as this, scientists said, may have a promising future in the identification and surgical removal of malignant tumors, as well as using near-infrared light therapies that can kill remaining cancer cells, both by mild heating of them and generating reactive oxygen species that can also kill them.

“This is kind of a double attack that could significantly improve the success of cancer surgeries,” said Oleh Taratula, an assistant professor in the OSU College of Pharmacy.

“With this approach, cancerous cells and tumors will literally glow and fluoresce when exposed to near-infrared light, giving the surgeon a precise guide about what to remove,” Taratula said. “That same light will activate compounds in the cancer cells that will kill any malignant cells that remain. It’s an exciting new approach to help surgery succeed.”

The work is based on the use of a known compound called naphthalocyanine, which has some unusual properties when exposed to near-infrared light. It can make a cell glow as a guide to surgeons; heat the cell to kill it; and produce reactive oxygen species that can also kill it. And by adjusting the intensity of the light, the action of the compound can be controlled and optimized to kill just the tumor and cancer cells. This research was done with ovarian cancer cells.

However, naphthalocyanine isn’t water soluble and also tends to clump up, or aggregate, inside the body, in the process losing its ability to makes cells glow and generate reactive oxygen species. This also makes it difficult or impossible to find its way through the circulatory system and take up residence only in cancer cells.

OSU experts overcame these problems by use of a special water-soluble polymer, called a dendrimer, which allows the napthalocyanine to hide within a molecule that will attach specifically to cancer cells, and not healthy tissue. The dendrimer, an extremely tiny nanoparticle, takes advantage of certain physical characteristics that blood vessels leading to cancer cells have, but healthy ones do not. It will slip easily into a tumor but largely spare any healthy tissue.

Once in place, and exposed to the type of light needed, the cancer cells then will glow – creating a biological road map for a surgeon to follow in identifying what tissues to remove and what to leave. At the same time, a few minutes of this light exposure activate the naphthalocyanine to kill any remaining cells.

This one-two punch of surgery and a nontoxic, combinatorial phototherapy holds significant promise, Taratula said. It’s quite different from existing chemotherapies and radiotherapies.

“For many cancers, surgery is a first choice of treatment,” Taratula said. “In coming years we may have a tool to make that surgery more precise, effective and thorough than it’s been before.”

Before attempting human clinical tests, OSU researchers hope to perfect the process and then collaborate with Shay Bracha, an assistant professor in the OSU College of Veterinary Medicine, to test it on live dogs that have malignant tumors. The technique has already been shown successful in laboratory mice. Worth noting, the researchers said, is that even as phototherapy was destroying their malignant tumors, the mice showed no apparent side effects and the animals lost no weight.  

Systems with technology similar to this are also being tested by other researchers, but some of them require several imaging and therapeutic agents, repeated irradiation and two lasers. This increases cost, may lessen effectiveness and increase risk of side effects, OSU researchers said in their report.

This research was supported by the OSU College of Pharmacy, the Medical Research Foundation of Oregon and the PhRMA Foundation.

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Oleh Taratula, 541-737-5785

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Phototherapy system
Phototherapy system

Biomarker could provide early warning of kidney disease in cats

CORVALLIS, Ore. – Researchers from Oregon State University and other institutions have developed a new biomarker called “SDMA” that can provide earlier identification of chronic kidney disease in cats, which is one of the leading causes of their death.

A new test based on this biomarker, when commercialized, should help pet owners and their veterinarians watch for this problem through periodic checkups, and treat it with diet or other therapies to help add months or years to their pet’s life.

Special diets have been shown to slow the progression of this disease once it’s identified.

The findings were made in a controlled study of 32 healthy, but older cats, and have been published in The Veterinary Journal by researchers from OSU and IDEXX Laboratories. They demonstrated the efficacy of a biomarker that could form the basis for a new diagnostic test.

“Chronic kidney disease is common in geriatric cats and often causes their death,” said Jean Hall, a small animal medical expert and professor in the OSU College of Veterinary Medicine. “Damage from it is irreversible, but this is an important advance, in that we should be able to identify the problem earlier and use special diets to slow the disease.”

Many of these same health issues also relate to older dogs, and in continued research scientists believe they may make similar findings.

Renal decline is normal in most cats, experts say, as they reach 12-18 years of age, and along with issues such as cancer and gastrointestinal disease is one of the more common causes of death. But studies have shown that the problem can also be managed with special foods that reduce protein and phosphorus, while adding fish oil, antioxidants, L-carnitine and medium-chain triglycerides.

This biomarker was able to identify the onset of kidney disease in cats on average 17 months earlier than any existing approach, and in at least one case four years earlier. With special diets and care, some cats have lived several years after the disease was diagnosed.

The only existing test for the disease, which has been used for decades, is a blood test that checks creatinine levels, a marker of the breakdown of muscle protein. However, cats lose lean body mass as they age, so creatinine levels may be normal.  SDMA is not influenced by lean body mass and thus more accurately diagnoses the loss of kidney function, even if lean body mass has decreased.

The early symptoms of this disease are fairly non-specific, such as loss of appetite, weight loss, or vomiting.

The cats in this research were housed at the Science and Technology Center of Hill’s Pet Nutrition Inc.  The company provided data and samples for analysis in order to better understand the dietary needs of cats with early renal disease, and initiated the study to investigate how best to lengthen and enrich the lives of cats with the condition.

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Jean Hall, 541-737-6537

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Aging cat

Virulent bacteria affecting oysters found to be a case of mistaken identity

CORVALLIS, Ore. -  The bacteria that helped cause the near-ruin of two large oyster hatcheries in the Pacific Northwest have been mistakenly identified for years, researchers say in a recent report.

In addition, the study shows that the bacteria now believed to have participated in that problem are even more widespread and deadly than the previous suspect.

Although the hatchery industry has largely recovered, primarily by better control of ocean water acidity that was also part of the problem, the bacterial pathogens remain a significant concern for wild oysters along the coast, researchers said.

For many years, it had been believed that the primary bacteria causing oyster larval death in the Pacific Northwest was Vibrio tubiashii. Now, scientists say that most, or possibly all of the bacterial problem was caused by a different pathogen, Vibrio coralliilyticus, a close cousin that’s now known to be even more virulent to Pacific oysters.

The findings were published in Applied and Environmental Microbiology, by researchers from the College of Veterinary Medicine at Oregon State University, the U.S. Department of Agriculture, and Rutgers University. The research was supported by the USDA.

“These bacteria are very similar, they’re close cousins,” said Claudia Häse, an OSU associate professor and expert in microbial pathogenesis. “V. coralliilyticus was believed to primarily infect warm water corals and contributes to coral bleaching around the world. It shares some gene sequences with V. tubiashii, but when we finally were able to compare the entire genomes, it became apparent that most of what we’re dealing with in the Pacific Northwest is V. coralliilyticus.”

Scientists now say that V. coralliilyticus is not only far more widespread than previously believed, but that it can infect a variety of fish, shellfish and oysters, including rainbow trout and larval brine shrimp. And it appears to be the primary offender in bacterial attacks on Pacific Northwest oyster larvae.

OSU experts have developed a rapid diagnostic assay for this bacteria that is nearing commercialization, and it may help assess problems both in oyster and coral health, Häse said.

“Although we’ve largely addressed the problems the hatcheries face, these bacteria continue to pose threats to wild oysters,” Häse said. “And corals are still declining in many places, the Great Barrier Reef in Australia is dying at an alarming rate. Better diagnostics might help in all of these situations.”

In what’s now understood to be a problem with multiple causes, these pathogenic bacteria were involved in major crashes of oyster hatcheries, causing shortages in seed oysters for commercial producers. Dramatic losses were suffered in a Netarts Bay, Oregon, hatchery in 2005, and Washington hatcheries were also hard hit. Bacterial infection, water acidity, oxygen depletion and rising seawater temperatures are all believed to have been part of the problem.

By better monitoring and control of water acidity, which was one serious concern, hatcheries have been able to regain most of their productive capabilities. Wild oysters, however, continue to face the multiple pressures from rising acidity, pathogenic bacteria and other forces that have led to serious hatchery mortality.

Those problems have not been made any easier by the lack of funding for identification and studies of the bacteria that researchers now know to be causing infection.

In laboratory tests, strains of V. tubiashii did not show significant pathogenicity to Pacific oysters. V. coralliilyticus, by contrast, is highly infectious to both Pacific and Eastern oyster larvae, and perhaps other shellfish species.

“The Vibrio genus and many bacteria associated with it are a huge problem in fish and shellfish aquaculture, and we should be studying them more aggressively,” Häse said. “V. coralliilyticus, in particular, has a very powerful toxin delivery system, and vibrios are some of the smartest of all bacteria. They can smell, sense things and swim toward a host.”

It’s believed that increasing environmental stresses may make oysters and other marine life more vulnerable to these types of bacterial infection, researchers say.

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Claudia Häse, 541-737-7001

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