Category Archives: Faculty

Video

Surprise party for world-renowned anatomist Dr. Howie Evans’ 90th

Happy 90th Birthday to Dr. Howie Evans, anatomist extraordinaire and beloved professor of countless Cornell veterinarians! Dr. Evans continues coming to work even today, updating his seminal text on dog anatomy and collecting goodies for volunteer visits to local schoolchildren.

He continually inspires people of all ages with show-and-tell wonders from across the animal kingdom. We held a surprise birthday party for Howie, shown in this video. You can post your own birthday wishes on the video on our Facebook Page.

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http://www.vet.cornell.edu/news/EvansBirthday.cfm

Surprise packages sent by cancer cells can turn normal cells cancerous

Surprise packages sent by cancer cells can turn normal cells cancerous, but Cornell scientists have found a way to keep their cargo from ever leaving port. Published in Oncogene in January 2012, their study demonstrates the parcels’ cancer-causing powers, describes how they are made, and reveals a way to jam production. Treatments that follow suit could slow tumor growth and metastasis, the spread of cancer to new parts of the body.

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A cancer cell (bottom right) producing and shedding microvesicles, which travel between cells and attach to a normal cell (upper left) to unload cancerous cargo

Remote recruiting through inter-cellular mail lets cancer cells grow their ranks without having to move. While most cells communicate through a standard postal system of growth factors and hormones, cancer cells and stem cells use bulkier parcels called microvesicles. These big packages are stuffed with unconventional cargo that boosts the survival and growth rates of recipient cells and can dramatically alter their behavior and surrounding environment. The cargo of microvesicles includes unique sets of proteins that often reflect their cell of origin and are capable of completely changing a cell’s form and function.

“Stem cells make microvesicles containing one set of proteins that can help heal damaged tissue, while cancer cells make malignant microvesicles called oncosomes that contain another set of proteins which facilitate the growth and spread of tumors,” said Dr. Richard Cerione, professor at the College of Veterinary Medicine and co-author.

Dr. Marc Antonyak and graduate student Bo Li, co-authors and researchers in Cerione’s lab, examined cells in culture to observe the effects of oncosomes on normal cells. They focused on fibroblasts, a normal cell type that is often found associated with human tumors and helps to facilitate tumor growth.
“We incubated healthy fibroblasts together with aggressive breast cancer cells,” said Antonyak. “Although we’d disabled the cancer cells from forming tumors on their own, they kept pumping out oncosomes. The fibroblasts that were bathed in these oncosomes began turning cancer-like, living longer, growing faster, and forming tumors.”

Using a variety of techniques to parse out participating proteins, including immunoblot analysis, immunofluorecence, and electron microscopy imaging, Antonyak identified each link in this pathway and traced it back to the first: a protein called RhoA that acts like a lever initiating microvesicle production. Cancer cells crank production into overdrive, said Antonyak, but jamming the lever could stop the whole assembly line.

“Even if we immobilize cancer cells, as long as they can make these microvesicles they can continue spreading vital components for the development of cancer,” said Cerione. “It’s clear that microvesicles can change the behavior of cells and play an important part in cancer progression. Treatments targeting the microvesicle production pathway we’ve outlined could have a real impact on slowing cancer progression.”

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http://vet.cornell.edu/news/CancerCargo.cfm

 

Ticks untold

Prime suspects in mystery fevers may hold new tick-borne diseases
Suddenly your horse is sick and you don’t know why. She breathes normally but her temperature is rising, her eyes grow yellow with jaundice, she seems depressed, and barely eats. The fever is clear but the cause is not; even the most experienced experts can offer no concrete answers. Eventually the fever fades, but is that the end of whatever caused it or is the source still lurking somewhere inside?

Horse owners across the states are facing this distressing scenario. At the Cornell University Animal Health Diagnostic Center (AHDC), Dr. Linda Mittel fields a growing number of calls about these mysterious fevers of unknown origins (FUOs). Many come from the Northeast, Mid-Atlantic, and Great Lakes areas: the nation’s topmost hotbeds of human tick-borne disease. This pattern led Mittel to suspect that the culprits of the fever caper could be ticks and the difficult-to-diagnose diseases they carry.

“Tick-borne diseases are some of the fastest growing emerging diseases in the United States right now,” said Mittel. “As ticks continue expanding their numbers and geographic range these diseases may affect new areas. We get calls about fevers at broodmare operations, showbarns, and farms where race horses rest or layup, even in areas where they didn’t know they had ticks. But horses moving between states can move ticks with them, and the effects of this movement are starting to show.”

Mittel and colleagues at the AHDC are embarking on a project to find just what diseases ticks in hotbed zones are carrying and whether they are behind the wash of mystery fevers in horses. The study will use samples from horses suffering FUOs to look for bacterial infections known to be transmitted by ticks (Anaplasma, Babesia, Borrelia, Ehrlichia, and Rickettsia) as well as other bacteria known to cause non-respiratory infection in horses (Leptospira, Bartonella, and Neorickettsia.)

These agents are considered emerging infectious diseases in humans, and this will be the first study determining their presence in horses with FUOs. The study will also sample ticks found on or near horses in designated areas to find which pathogens they carry and to potentially discover previously undocumented tick-borne pathogens.

Many tick-borne diseases are sensitive to specific drugs; others are not sensitive to antibiotics at all. Knowing which diseases are at the root of FUOs will help veterinarians treat them effectively. It will also help owners understand how the causes of fevers might impact affected horses’ futures in racing, performance, or showmanship.

“I’m quite excited to start solving the mysteries of these fevers and to possibly uncover new previously unrecognized diseases – in horses and people,” said Mittel. “If these agents are in the horses, humans may also have them without realizing– people who work with these horses might be particularly at risk. Knowing what we’re dealing with here will hopefully solve the mystery of FUOs and help equine and human medicine recognize and address the growing onslaught of tick-borne disease.”

This research is funded by the Harry M. Zweig Memorial Fund for Equine Research.

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Dr. Cynthia Leifer honored with 2012 Pfizer Animal Health Award

LeiferDr. Cynthia Leifer, assistant professor of immunology at Cornell University’s College of Veterinary Medicine, has been selected to receive the Pfizer Animal Health Award for Veterinary Research Excellence. The award fosters innovative research by recognizing outstanding research and productivity from a faculty member early in his or her career. Nominees are selected for innovative research relevant to animal health that is likely to make national impact.

Leifer’s research sheds light on the currently cloudy causes of autoimmune disease by uncovering inner workings of the innate immune system. Afflicting one in five Americans, autoimmune diseases include a wide array of disorders from rheumatoid arthritis to the skin disease Lupus to irritable bowel syndrome.

“The immune system fights to protect us against invading microorganisms,” said Leifer. “But it must also recognize what to attack and keep its aggressive responses under control to prevent damaging our own bodies.”

When recognition and regulation fail, the immune system can attack the body and lead to autoimmune disorders. Leifer explores how immune cell receptors affect the way these cells recognize and respond to whatever they encounter, whether it’s a microbial invader or a piece of the self.

“Most innate immune receptors identify microbes by detecting unique structures found only on microbes,” said Leifer. “But some work by detecting structures present in both microbes and the self, such as DNA.”

Focusing her research on one such receptor, Toll-like receptor 9 (TLR9), Leifer recently discovered how TLR9 makes the kind of recognition mistakes that lead to autoimmune attacks, opening the door to new possible autoimmune disease therapies.

“Identifying immune-cell regulation systems may reveal therapeutic targets for managing TLR9 function, leading to new treatments for autoimmune diseases,” said Leifer.

Leifer will present her research at a special seminar to be held in September 2012. At a ceremony that follows she will receive an award of $1,000 and an engraved plaque.

“This is a great honor for Dr. Leifer at this stage of her career,” said Dr. Avery August, chair of the department of microbiology and immunology. “Her cutting-edge work on how the immune system senses pathogens is being recognized, and she will join a distinguished list of Cornell faculty who have received this award. We congratulate her on this great accomplishment.”

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College of Veterinary Medicine News
http://www.vet.cornell.edu/news/LeiferPfizer.cfm

 

Classroom innovation prepares students for clinics and professional life

Whatever their background, most new veterinary students share one desire: to work with animals as soon as possible. Continuous modifications and improvements to the curriculum—in response to input from faculty, students, alumni, and employers— have resulted in a history of  classroom adaptations in Cornell’s veterinary curriculum that continually bring students closer to the action sooner.

“We want to give students the tools they’ll need as veterinarians as early as possible so they can refine them over the time they’re with us,” said McDaniel. “Last Fall we introduced a new set of labs in which first-years perform basic procedures on all major species. After spending mornings learning anatomy while dissecting cadavers in Block I they look at the same structures in live animals in the afternoon. It gives these young people a wonderful sense of accomplishment and they can practice these skills during their summer experiences.”

Teaching skills to students sooner, the Clinical Procedures module now precedes the Public Health module, helping students gain comfort with one of medicine’s most infamously difficult endeavors: surgery.

“Surgical skills are hard for students; there’s a steep learning curve for handling instruments,” said McDaniel. “Past students got their first surgery experience in their third year. Now incoming first-years learn correct instrument handling from real surgeons and more advanced techniques and suture patterns in the spring.”

In response to student suggestions in course evaluations instructors introduced discussion sections to the Ethics and Animal Care module.  Small groups of students discuss ethically charged scenarios and share perspectives. The module’s latter portion now includes new lectures and discussions on animal nutrition.

The Community Practice Service (CPS) began offering underclassmen new opportunities to observe appointments run by fourth-year students and to practice communicating with clients by conducting brief patient-history interviews on camera. Peers and faculty use the recording to offer students constructive feedback on communication skills. Meanwhile, third-year students in the Communication Skills module must navigate new simulated client interactions involving actors playing clients with varied temperaments.

These classroom innovations aim to build solid foundations of competence and confidence they will need in their next stage of training and professional life.

“We meet students when they first walk in the door and begin equipping them with skills they’ll need in the clinics and beyond,” said Dr. Carolyn McDaniels, veterinary curriculum instructor and current director of Course VII. “This kind of course never existed when I was in school.”

Course VII, or “Block VII”, revolutionized veterinary learning at Cornell nearly twenty years ago. A foundation course, its six sequential sections span students’ first 2.5 years. Former course director Dr. John Ludders, professor emeritus of anesthesiology, has seen it through its multifaceted evolution.

“Back when we were designing the ‘new curriculum’ we realized students would miss basics such as examination skills, ethics, and public health,” recalled Ludders.  “So Dr. John Saidla designed a course called ‘Block VII’ to fill curricular gaps. The students really appreciated the course. When he left around 1999 several clinical faculty stepped up to help lead and refine the course.

“Students seemed inadequately prepared for clinic rotations. They could not perform some basic tests or properly restrain patients, and had problems understanding basic public health issues. So we revised Block VII to strengthen physical examination skills, teaching students to milk dairy cattle, perform diagnostic procedures in cadavers, complete governmental health certificates for patients, and use basic clinical equipment.”

Course VII became a catch-all repository for essential material not covered in the other six blocks. Last year, with the help of several faculty and former course directors, Dr. McDaniel led the course through its most recent innovations.

“In teaching I often ask myself and my students what makes someone a great veterinarian,” said Dr. McDaniel. “There has to be a knowledge base, but they also most have technical hand skills and the ability to communicate effectively. The first six blocks in the curriculum build the knowledge base. We cover the rest. That’s two thirds of a veterinarian’s most important learning.  I love watching students become veterinarians over the three years we see them in this course.”

‘Scopes Magazine
October 2011

Reining in Roaring


Earlier detection and new treatments for horse racing’s number-one performance problem


It’s a big day at the track. Years of training and thousands of dollars are at
stake. The gates open and your horse lunges forward. But his breath comes
in gasps. It looks as if he’s wearing a heavy mask that is blocking his access to
air. Worn nerves signal sluggishly to weakened muscles that barely respond
enough to open his airway. He slows and falls to the back of the pack.

This career-limiting problem affects nearly 8 percent of race horses and a higher percentage of sport horses. Oficially called “recurrent laryngeal neuropathy,” the common equine disease is better known as “roaring” for the strained sounds affected horses make when they try to run. It shares similarities with human vocal cord paralysis, a neurological condition
causing difi culty breathing and loss of speech and requiring tracheostomy and intensive surgery. Roaring starts early and
unseen, slowly wearing down the nerves that stimulate the muscle responsible for opening the larynx.

“Upper airway problems cause poor performance in many race horses,” said Dr. Jonathan Cheetham, an equine surgeon and sports medicine practitioner at Cornell’s Equine Hospital. “Symptoms often show in a horse’s second to fourth year, when a trainer has already invested thousands in its athletic career. The standard treatment, surgery called a laryngeal tie-back together with a ‘lazer hobday’ procedure to remove the vocal cords, returns 65-70 percent of treated horses to racing. But that’s after six weeks of recovery and another six weeks to regain fitness. It takes a toll on the horses, their trainers, and the racing economy.”

Taking roaring by the reigns, Dr. Cheetham and the Equine Performance Clinic team are helping to change how veterinarians look at and treat the disease. The team running the Clinic’s indoor treadmill offers good client service while researching new methods to diagnose disease earlier and improve treatments.

According to Cheetham, the horse is a useful preclinical model of human airway disease. Much of what he is learning and working out at Cornell could help restore function in human patients with laryngeal disease. The Equine Performance Clinic pioneered techniques using a trans-esophageal ultrasound to evaluate airway muscles in horses.  Developed at Cornell with support from the Harry M. Zweig Memorial Fund, these techniques could give human doctors a new view of deteriorating laryngeal muscles and let them follow progress after treatment.

The team is developing a novel treatment for roaring using a laryngeal pacemaker to electronically stimulate the muscle and maintain its function: another technology applicable to humans with vocal paralysis.

Cheetham has spent the past year developing new ways of detecting neurological disease earlier, thanks to a grant from the Grayson Jockey-Club Foundation.

“Motor nerves need insulation from myelin sheathes to carry signals quickly,” said Dr. Cheetham. “Laryngeal neuropathy works by breaking down myelin in the two major meter-long nerves controlling the horse’s airway muscles, slowing their conduction velocity and cutting off the muscles from adequate stimulation. If we can use nerve conduction velocity to detect early myelin breakdown we may be able to catch the disease before the muscle starts shrinking.”

Placing tiny needles into the nerves, Dr. Cheetham measured conduction speeds across their length to see how speeds vary across the nerves. Next he will validate a technique that does not use needles and look at how nerve conduction velocity at the weanling stage affects performance of 2-year-old horses with the hope of confirming it as a viable diagnostic and predictive tool. Validating such a test would expand the window of detection and open doors to earlier prevention and treatments, and aid understanding of the disease mechanisms that produce ‘roaring’ in horses.

“We have also been developing ways of enhancing nerve grafting using tissue engineering techniques,” said Dr. Cheetham. “If we can pick up problems early, we might be able to treat without invasive surgery or a permanent implant. It could be safer, cheaper, and faster, and may improve the success of recovery from airway diseases in both horses and humans.”

Discuss this work with Dr. Cheetham on Facebook
https://www.facebook.com/CornellEquine
Visit the Equine Performance Center website
http://www.vet.cornell.edu/labs/eptc/intro.htm

‘Scopes Magazine
October 2011

Taking a bite out of dental disease

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A conversation with Dr. Santiago Peralta, veterinary dentist, oral surgeon, and
new Lecturer in the Department of Clinical Sciences’ Section of Dentistry.

What path led you to your new position?

I grew up and studied in Colombia, South America, and graduated with a veterinary degree from La Salle University in 1999. In Botoga I worked in private practice for seven years and became interested in dentistry and oral surgery. As my interest grew, I decided to pursue further study in this specialty and completed a 3-year residency in veterinary dentistry at UC Davis between 2006-2009. Returning home, I resumed private practice until coming to Cornell in Summer 2011.

What will you offer as part of the dentistry service?

We offer state of the art dental and oral care for animal patients. Our service deals with small and large animals, and my focus will be small animals, mostly dogs and cats. I also have experience with exotic pets such as rabbits, chinchillas, and guinea pigs, as well as zoo animals including tigers, hyenas, orangutans, and more.

Our most common dental treatments deal with periodontal disease (gum disease), the most prevalent disease of animals.  Other advanced dental procedures we offer include endodontics (root canals) to fractured teeth, orthodontics to correct bite abnormalities, oral surgery following facial trauma or to remove tumors.

What innovations do you bring to CUHA?

I’ve helped move our service from hand instrumentation techniques to more precise rotary root canal instrumentation techniques that provide more reliable results, higher success rates, and lower anesthesia times. These newer techniques come together with safer and more effective materials that allow success rates of therapy similar to that seen in humans.

Do you have research plans?

My main research interest involves tooth resorption, a common cat and dog disease in which the teeth degrade and disappear. Nobody has figured out why, and that is a question I’d like to pursue. I am also interested in research concerning oral tumors and oral radiology.

What do you like about your job so far?

I like the academic culture, and the opportunity to provide real clinical instruction. Interacting with students and other specialists offers a stimulating educational environment where everyone has something to learn. The opportunity to help out the community, clients, and local veterinarians is very rewarding.

Why is dentistry important and how can owners help?

Dental disease can lead not only to oral discomfort and pain, but can dramatically affect the general health of an animal. It can cause inflammation and infection that can spread to other organs or turn the blood toxic through permanent bacterial infection. Pets may stop eating, bleed from the mouth, and show discomfort.

Animals are very stoic in nature; they are good at hiding pain. Owners underestimate dental disease and often don’t realize their pets are suffering from it until it’s too late. Owners can help by bringing pets in for yearly routine oral exams, yearly or biyearly professional dental treatment. Toothbrushing is the only way to prevent periodontal disease. Just like in humans, it should be done every day.

Oral hygiene is very important for pets, and the magnitude of disease is difficult to appreciate until after treatment. The improvement in a pet’s demeanor following treatment can be amazing to see.

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http://www.vet.cornell.edu/news/santiago.cfm