Showing posts with label IGF. Show all posts
Showing posts with label IGF. Show all posts

Monday, October 22, 2012

Prepare for Takeoff: Orsini and Grenager Summary of Laminitis Research at California "Equine Limb" Conference


 in Monterey, California on November 2 and 3, 2012.


When the "Equine Limb" conference opens in Monterey, California next weekend, attendees who are interested in learning about the latest equine laminitis research won't have to wonder, "What page are we on?"

Jim Orsini, conference co-director
with Rustin Moore
It's very easy to dive right into the deep end when it comes to covering laminitis research and treatment, and the conference is carefully planned to simulate a 747 jetliner taking off from a busy international airport: it seems physically impossible for it to become airborne, but it does it by acceleration and lift computed at exactly the right equation. Gravity is defied.

Planning a laminitis conference is very similar. And Dr. Jim Orsini of Penn Vet's New Bolton Center and equine practitioner Nora Grenager are the masters of the craft.

These two standard-bearers of the The Laminitis Conference organizing committee are planning a takeoff that would look familiar to air traffic controllers in their towers. They will review recent research thoroughly but quickly. You should buckle your seat because the conference will reach cruising altitude before you know it!

The review of laminitis research begins at the Monterey event's partner conference, the 2011 International Conference on Laminitis and Diseases of the Foot held in West Palm Beach, Florida, last November; the scientific program there centered on the pathophysiology of laminitis. While the California event has expanded to cover a broader spectrum, its heart is still beating with the mission of solving the laminitis puzzle.

Some highlights that Orsini and Grenager will touch on:

Nora Grenager will review laminitis
research from the Florida conference
as a preface to the California event.
First, the difference between sepsis and systemic inflammatory response syndrome (SIRS), two terms often used interchangeably in laminitis lectures. But when you hear the word sepsis, does it suggest something like a "septic joint", an overwhelming bacterial infection? How does sepsis factor into laminitis? Semantics? Maybe, but it is critical to understanding the new research.

The 2004 Presidential election may have come down to "Florida, Florida, Florida," but the laminitis conference attendees left chanting, "Inflammation, inflammation, inflammation".

But what about the endocrinopathic form of laminitis? Equine metabolic syndrome and Cushing's disease (PPID) research is burgeoning, along with the role of hyperinsulemia (HI). Insulin levels are being re-evaluated as sirens to all sorts of equine health conditions, large and small.  How exactly does hyperinsulemia cause a horse to develop laminitis?

For that answer, researchers looked directly at how insulin functions (or doesn't) in the foot. The role of insulin-like growth factor (IGF) is a critical area of research, since it is possible that insulin is working through a different mechanism in the equine foot's vasculature than it does in the rest of the body.

Can you hear a second chant rising in the background? "IGF, IGF, IGF!"

Laminitis related to hyperinsulemia is the slow, insidious form of the disease, and the one most commonly seen in our horses. The obesity that accompanies it is reversible, and the predisposition of some breeds to hyperinsulemia mean that it is becoming clearer that early identification and therapy for horses at risk must be a priority in the field.

In their abstract, the authors wrote, "Even in horses with no history of lameness, there is a pattern of abnormal hoof growth that is related to HI: abnormal growth rings in the external hoof wall, separation of the wall at the white line, and seedy toe, often with small areas of hemorrhage within the abnormal white line area. This damage is cumulative and at some point culminates in acute laminitis if not properly addressed with diet, exercise, and medication where necessary to normalize blood insulin concentrations."

Support limb laminitis will also be reviewed, and new information on the distinct form of the disease known as "traumatic laminitis", which researchers at Dr. Chris Pollitt's Australian Equine Laminitis Research Unit have outlined. Researcher Brian Hampson PhD discovered that wild horses on arid terrain suffer concussive and/or compressive laminar pathology. Is this laminitis, per se? Much more research on traumatic laminitis needs to be done, but you'll hear about the first phases of this exciting concept.

"Feral horses have little option but to keep moving and either adapt or make do the best they can if they are to survive. In a domesticated horse, comparable changes typically are accompanied by chronic lameness or stiffness, and are incompatible with optimal performance."

That statement in itself is food for thought. While Hampson and Pollitt have cast some doubt on the suitability of the wild horse foot as the ideal equine digit, it seems that there may be deep and profound lessons that can be learned from our domestic horses' wild brethren.

And that, in itself, is just one of the vistas you'll be able to see from the thought clouds of this world-class conference. Distal limb lameness and imaging have been added to the program this year, as the conference's horizons expand over the curvature of the distal limb planet.

If you haven't already reserved your spot at the conference, please do it now. Much more information and a full speaker program is online at www.laminitisconference.com.


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Disclosure of Material Connection: I have not received any direct compensation for writing this post. I have no material connection to the brands, products, or services that I have mentioned, other than Hoofcare Publishing. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: Guides Concerning the Use of Endorsements and Testimonials in Advertising.

Friday, July 01, 2011

Laminitis Research: Australian Breakthrough on Insulin Function in Equine Foot

(Text published as provided)

Researchers funded by the US-based Animal Health Foundation announced June 15, 2011, that they have made a major breakthrough in understanding how the insulin form of laminitis occurs.

Drs. Melody de Laat and Chris Pollitt of the Australian Equine Laminitis Research Unit at the University of Queensland have discovered that receptors designed to receive insulin-like growth factor 1 (IGF-1) may be binding to insulin instead if horses have high levels of insulin.

This groundbreaking discovery may enable scientists to develop strategies to try to block IGF-1 receptors from receiving insulin and prevent the disease from occurring.

The receptor also has been shown to be responsible for the metastatis of malignant tumors in humans, and drugs currently are being developed to block the receptor. These drugs may be of use in trying to treat horses that are prone to laminitis from developing high levels of insulin.

Insulin is important in regulating the blood glucose within animals, but horses that have Equine Metabolic Syndrome and Cushing’s disease often have very high levels of insulin.

Pollitt and his team, funded by AHF since 1995, previously showed that high insulin is one of the major pathways that causes laminitis, but, to this point, they had not understood how.

The equine foot is very dependent on glucose for metabolism, but it is not dependent on insulin to deliver that glucose. Horses have a large number of IGF-1 receptors in their feet, but no insulin receptors. Pollitt’s team now theorizes that these IGF-1 receptors are being stimulated by insulin that mimics insulin-like growth factor 1 and is binding to these receptors.

When this happens, the laminar epitheleal cells start to proliferate. Normally these cells in the middle of the foot don’t multiply. The cells are made at the coronary band and migrate all the way down to the sole without multiplying.

This type of proliferation causes the laminae to stretch and lengthen and the weight of the horse to ruin the bond between the external hoof wall and the bone. The bone changes position, and laminitis occurs.

“We’re starting to understand the pathway of how insulin really causes laminitis,” said Dr. Don Walsh, president of the Animal Health Foundation.

Journey from coffin bone to periople in a colorful detailed super-microscopic image! Click to order!

 © Fran Jurga and Hoofcare Publishing; Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. Please, no use without permission. You only need to ask. This blog may be read online at the blog page, checked via RSS feed, or received via a digest-type email (requires signup in box at top right of blog page). To subscribe to Hoofcare and Lameness (the journal), please visit the main site, www.hoofcare.com, where many educational products and media related to equine lameness and hoof science can be found. Questions or problems with this blog? Send email to blog@hoofcare.com.  
 
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Disclosure of Material Connection: I have not received any direct compensation for writing this post. I have no material connection to the brands, products, or services that I have mentioned, other than Hoofcare Publishing. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: Guides Concerning the Use of Endorsements and Testimonials in Advertising.