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Biliary and Urologic Stone Fragmentation
Initial work successfully demonstrated that the holmium laser is useful and a practical alternative to the pulsed dye laser as a tool in laser lithotripsy of gallstones. Current work involves formulation of a physical model of the fragmentation process. Its been discovered that the fragmentation of gall stones is a multi-step process and that absorption of laser light by both the cholesterol in the gallstone and by the water in the aqueous environment is required in order to effectively fragment the stone. The holmium laser lithotripsy technique has the potential to also be used for clinical applications in treatment of urologic calculi in both humans and animals.
Sponsors: Presbyterian Health Foundation, Founders of Doctors Hospital, Kirkpatrick Foundation, and Oklahoma Center for Laser Development and Applications
PIs: Kenneth E. Bartels and Steven A. Schafer
Holmium Laser Ablation of Thoracolumbar Discs in Chondrodystrophoid and Nonchondrodystrophoid Dogs
Intervertebral disc disease is a common neurologic problem seen in certain breeds of dogs, as well as humans. Using the dog as a model, we have developed an alternative to surgical treatment of degenerative intervertebral discs. By percutaneously placing optical fibers into the centers of each disc to be treated and then irradiating the disc with light from the holmium laser, we can ablate the nucleus pulposus of the disc without damaging surrounding structures such as the spinal cord. Preclinical and clinical investigations have taken place, and the results revealed no harmful side effects for up to 2 years. Continued monitoring and histopathological evaluation of the model will be used to determine the long-term effects of laser treatment and how it can potentially effect the treatment of the condition in the human.
Sponsors: Presbyterian Health Foundation, MicroFab, Inc., National Institutes of Health, Founders of Doctors Hospital, and Oklahoma Center for Laser Development and Applications
PIs: Kenneth E. Bartels, D. Thomas Dickey, George Henry, Eric L. Stair, Steven A. Schafer, and Robert E. Nordquist
Medical Applications of Diode Lasers
Compact, inexpensive semiconductor diode lasers hold tremendous potential for therapeutic and diagnostic applications. In collaboration with Phillips Laboratory (U.S. Air Force), Diomedics, Inc., and McDonnell Douglas Corp., we have developed prototypes and applications of this laser in both veterinary and human medicine. Included in this project are investigations involving tissue sterilization/disinfection, visual laser ablation of the prostate gland, intervertebral disc ablation, selective photothermolysis for treatment of breast cancer, and tissue fusion.
Sponsors: Presbyterian Health Foundation, Founders of Doctors Hospital, Surgimedics, Inc., and U.S. Air Force
PIs: Kenneth E. Bartels, D. Thomas Dickey, Eric L. Stair, George Henry, Steven A. Schafer, Randy Willis, Robert Nordquist, and Don H. Hults
Development of a Directional Multiplex Coupler for Laser Hyperthermia
A "fiber multiplexer" has been developed capable of withstanding high power laser energy using a single fiber "coupled" to a multiple array of optical fibers (three to six) for the simultaneous delivery of low power laser energy for application of interstitial hyperthermia to multiple locations. This fiber multiplexer configuration also has potential use for the dispersion of laser energy during photodynamic therapy. The device consists of a single 600 to 1000 u optical fiber (2 meters in length) that is connected through the coupler to four to six optical delivery fibers (200 to 600 u diameter; 2 meters in length), which are placed directly into tissue. The fiber tips of this multifiber array can be cleaved, sculpted to conical or spherical configurations, or "frosted" for more diffuse dispersion of energy.
Sponsors: Oklahoma Center for Laser Development and Applications, and Surgimedics, Inc.
PIs: Kenneth E. Bartels, Mark Mellow, Robert Nordquist, Steven Schafer, and Raymond Zanoni
Photodynamic Therapy (PDT)
Since the acquisition of a KTP "driven" dye laser through the McCasland Foundation, initial protocols for experimental and clinical use of a new photosensitizer, pyropheophorbide-a-hexyl ether (HPPH #23), have been accepted by the FDA. In collaboration with the University of Missouri, the Beckman Laser Institute, the University of California at Davis, and the Roswell Park Cancer Institute in Buffalo, New York, treatment of oral squamous cell carcinoma and hemangiopericytoma in the dog and the cat will be initiated. This study has important ramifications in the future of similar PDT therapy regimes in humans through dosage, illumination, and toxicologic parameters.
Sponsors: Presbyterian Health Foundation, Founders of Doctors Hospital, Kirkpatrick Foundation, and McCasland Foundation
PIs: Kenneth E. Bartels, John Hoover, Steven Schafer, John Houck, Stanley Mills, Robert Nordquist, and Wei Chin
Use of Low Power Laser Radiation for Biostimulation
Recent delivery of a low power diode laser from the LaserMedic Company of Stafford, Texas, has resulted in submission of an objective protocol for evaluation of the ability of this low energy laser power to stimulate healing. Dr. Larry Stein of the OSU Veterinary Medicine Anatomy Department has established cell cultures of ovine fibroblasts and hopes to measure any "upgrade" in metabolism at the cellular level. Additionally, Dr. Steven Schafer of the Oklahoma Center for Laser Development and Applications hopes to objectively evaluate the laser output of this device, which will include both power and wavelength parameters.
Sponsor: Oklahoma Center for Laser Development and Applications
PIs: Larry Stein, Kenneth E. Bartels, and Steven Schafer
Veterinary Clinical Applications of Lasers in Medicine and Surgery
Clinical initiatives involving both small and large animal medicine have been explored extensively. Many types of tumors have been excised and ablated using laser energy with excellent long term results. In addition, use of laser energy transmitted via optical fibers passing through endoscopes has resulted in new and extremely novel techniques for treatment of equine laryngeal problems (entrapment of the epiglottis, ethmoid hematomas in the equine mares), equine endometrial cysts, and sarcoids. A multitude of small animal problems including nasal and oral squamous cell carcinoma, elongated soft palate, and "lick granulomas" have been treated with objective protocols and excellent results. A project evaluating the strength of healing tissue after laser incision is currently underway.
Sponsors: Presbyterian Health Foundation, Founders of Doctors Hospital, and Kirkpatrick Foundation
PIs: Kenneth E. Bartels, D. Thomas Dickey, Eric L. Stair, Robert Bahr, George Henry, Charles MacAllister, and Steven Slusher
Long-Term Effects of Holmium:YAG Laser Radiation on Cartilage Metabolism, Healing, and Biochemical Properties of Repaired Tissue and Subchondral Bone Healing in a Weight Bearing Chronic Lesion Model
Recent research studies utilizing Ho:YAG laser energies have shown promising results in providing an appropriate stimulus for cartilage repair processes with chondral proliferation and reduction of tissue reaction. Objectives of this research study are to (1) histologically compare perilesional cartilage, lesional repair tissue, and subchondral bone healing in control and treated groups following treatment of chronic full-thickness cartilage lesions and perilesional cartilage with a selected level of Ho:YAG laser energy and six months of continuous active weight bearing; and (2) to perform biochemical evaluation of lesional reparative tissue and perilesional cartilage, examining for upregulation of repair tissue following exposure to laser energy. This study will determine if the integrity and biochemical properties of repaired tissue can be improved by treatment with selected levels of laser energy and if cartilage metabolism can be upregulated and reparative tissue stimulated.
Sponsors: Lanny Johnson, M.D., Research Fund, Doris Stein Foundation, Beckman Laser Institute, and Coherent Medical Corporation
PIs: Michael Collier, Greg Pullin, Lanny Johnson, and Larry DeBault
Legg Perthes Disease
This study utilized the equine humoral epiphysis as a surgical model. A large defect was created in the equine proximal humoral epiphysis and received an autogenous bone graft into the iatrogenically created surgical lesion to simulate the clinical presentation of Legg Perthes disease. Radionuclear imaging and histology, including appropriately placed bone markers, were used to quanitate the reparative process in this pilot model. Successful completion will lead to development of a larger, long-term project to document the effectiveness of this newly designed surgical technique.
Sponsor: Lanny Johnson, M.D., Research Fund
PIs: Michael Collier, Greg Pullin, Lanny Johnson, and Larry DeBault
In vivo Study of Uptake and Distribution of Intramuscular Tritium-Labeled PSGAG (Adequan¨) in Articular Cartilage and the Effects on Physically Induced Arthritis and Synovitis in the Horse
Degenerative joint disease is a common cause of joint pain and impaired function, including lameness, in the horse. Destruction of articular cartilage is the primary injury in degenerative joint disease and frequently develops during race training and/or racing in thoroughbred and quarterhorse athletes. Degenerative changes within the joints of racing athletes are usually manifested as decreased performance and significant economic loss to the horse owner and racing industry. Articular cartilage damage in degenerative joint disease may be caused by acute or chronic injury or may develop secondarily to disease such as infectious arthritis. The study will determine the distribution of PSGAG, evaluate cartilage healing following surgical insult and treatment, and examine the influence of PSGAG on healing.
Sponsor: Luitpold Pharmaceuticals
PIs: Michael Collier and Larry DeBault
Effects of Autogenous Chondral Graft in Glycolic/Lactic Acid Copolymer Base and Blood Clot Adherence on Equine Articular Cartilage Defects
This study was designed to determine the effects of autogenous chondral graft in glycolic/lactic acid copolymer base and blood clot adherence on equine articular cartilage defects. Recent studies revealed that laser energy stimulated chondral proliferation in cartilage repair in vitro and in vivo. Defined energy levels consistently upregulated synthesis of cartilage proteoglycan, collagen, non-collagen protein, and DNA in the absence of histologic or biochemical evidence of enhanced matrix catabolism. Other studies have shown that blood clot adherence at the surgical site is equally imperative to initiate fibrocartilaginous and/or hyaline-like cartilage repair. We evaluated blood clot adherence in conjunction with autogenous chondral graft tissue in a glycolic/lactic acid copolymer base applied at the surgical site.
Sponsor: Lanny Johnson, M.D., Research Fund
PIs: Michael Collier, Lanny Johnson, and Larry deBault
Use of Force Sensing Array Technology in the Development of a New Equine Saddle Pad: Static and Dynamic Evaluations and Technical Considerations
Scientific approaches to the classical art of saddle-pad fitting with the horse have become available during the past few years. Force Sensing Array (FSA) technology has offered clinicians in the medical profession innovative systems for rehabilitation applications. With proven usefulness in the medical sector, the application of FSA technology in pressure mapping of the equine back and saddle has potential clinical and research applications in veterinary medicine.
The objective in this study was to apply FSA technology in evaluation of an equine athletic saddle pad and pad liners and to document any observed/potential areas of error within the system that would affect objectivity in data collection/interpretation. All dynamic scans demonstrated a repeatable pattern of pressure distribution that were associated with gait, load distribution, and horse limb placement. The in-motion scans gave the best overall evaluation of effectiveness of the pad liners studied.
This study did not define "normal" static or dynamic saddle-pad-horse pressure gradients or patterns. Potential exists for animal and operator induced error when using this technology. The pressure distribution pattern is the most valuable data to be gained from FSAs and should be the primary use of the device. Precise scientific methodology must be used in these type of studies.
Sponsor: Professional's Choice Sports Medicine, Inc.
PIs: Michael Collier, Greg Pullin, Chris Durham, and Jason Boelte
LACS Procedure Using the Ho:YAG Laser in a Canine Model: Intra-articular Pressure and Histological Observations
Recently, a new surgical procedure has been developed for the treatment of glenohumeral instability (GHI) called Laser-Assisted-Capsular-Shift (LACS). LACS procedures are performed via arthroscopic visualization using Ho:YAG laser energy application to GHI joint capsular and ligamentous tissues. Laser energy is applied until gross contraction or "shrinkage" of the capsular tissue is observed. A previous clinical retrospective study in humans included 41 procedures reporting 93% excellent/good results at six months follow-up (Thabit).
Controversy exists regarding the safety and efficacy of LACS. To date, no long-term in vivo animal model studies have been undertaken to evaluate morphologic or biochemical alterations to glenohumeral capsular tissues following exposure to Ho:YAG laser energy. Our hypothesis was that Ho:YAG laser energy capsuloplasty of the greyhound GHI joint would have an effect on intra-articular pressure (IAP) and volume and would show histologic evidence of capsular tissue shrinkage and laser-induced temperature denaturation and reannealment of collagen without undesirable tissue reaction.
The objectives were to study the effects of Ho:YAG laser energy on the structural state of the canine GHI joint capsular tissue using gross, histological, and static and dynamic IAP analysis. Additionally, this study was undertaken to determine if this procedure could be an in vivo animal model for the study of LACS in humans.
Sponsor: Lanny Johnson, M.D., Research Fund
PIs: Michael Collier, Greg Pullin, Lanny Johnson, and Larry DeBault
Technical Considerations For Acquisition, Analysis, and Archiving Static and Dynamic Intra-Articular Pressure Measurements for Laser Surgery Studies
Accurate measurement of intra-articular pressure (IAP) in static and dynamic studies is important in the evaluation of compartmentation of fluid within the joint and in the evaluation of other physiologic mechanisms affected by changes in intra-articular (i.a.) fluid pressure. Previous studies have evaluated various pressure measurement techniques in the evaluation of intracompartmental and IAP. These measurement systems rely on hydrostatic pressure transmission along a fluid column and have been shown to exhibit variability in pressure artifact and maintaining calibration. Additionally, these systems have a slow frequency response, which is undesirable in dynamic studies.
The Camino¨ catheter has been shown to allow accurate, high frequency response recording of IAP during CPM. However, additional design and instrumentation development are required to ensure a closed system during catheter insertion for accurate initial recording of subatmospheric pressures within some synovial joints and in digital data acquisiton and analysis of IAP obtained during CPM studies. Our hypothesis was that an instrumentation system consisting of a pressure transducer-tipped catheter system, graphical digital programming system, digital image capturing system, and specially designed computer would allow highly accurate scientific data acquisition and analysis for a wide variety of P/V, i.a. compliance, and i.a. surgical laser studies. The objectives were to collect and analyze data from static and dynamic CPM measurements of i.a. pressures in horses and dogs for repeatability and accuracy in data acquisition and management that could be used as baseline data in laser surgery P/V studies in those animal models and humans.
Sponsor: Equine Sports Medicine Chair Endowment Fund
PIs: Michael Collier, Gregg Pullin, Lanny Johnson, A.J. Pedowitz, Chris Durham, and Jason Boelte
Dynamic Normal Intra-Articular Pressures and Compliance During CPM in Equine Joints
Data acquisition from research and clinical cases during CPM after distension using various dynamic intra-articular surgical infusion systems is being collected to establish normals as the basis for joint pressure/volume and compliance studies. Additionally, flow dynamics of these various i.a. infusion systems is being studied during use in arthoscopic surgical procedures.
Sponsors: Equine Surgery/Sports Medicine Fund and Dyonics, Inc.
PIs: Michael Collier, Greg Pullin, Lanny Johnson, A.J. Pedowitz, Jason Boelte, and Chris Durham
Monitoring of Cardiac and Pulmonary Funtions in Veterinary Patients
The principle investigator for the study was funded in 1994 by Cardionics, Inc. to develop the recording and reproducing of normal and pathologic cardiac and respiratory ausculted sounds of domestic animals. This project is continuing in 1995. Previously recorded sounds and new recordings of clinical cases from dogs, cats, horses, and cattle with confirmed cardiac and respiratory diseases are digitalized for display (phonocardiogram or respiratory sounds with or without electrocardiogram), storage and retrieval, and replay. Digitalized sounds can be analyzed and correlated with disease conditions and pressure changes. This data is being developed for use in both teaching and clinical units. The first Cardionics, Inc. prototype veterinary unit was supplied to the University of Florida, Veterinary Medical Teaching Hospital, Gainesville, Florida, in the spring of 1995. A second unit was supplied to Iowa State University, Veterinary Medicine Teaching Hospital, Ames, Iowa, in the summer of 1995.
Sponsor: Cardionics, Inc.
PI: John P. Hoover
Efficacy Of Acupuncture Therapy For Navicular Syndrome
A double-blind controlled study of the efficacy of acupuncture therapy for navicular syndrome is being conducted. Documentation includes videotaped alterations in degree of lameness. Radiographic findings will also be evaluated for change.
Sponsor: The Grady Young Memorial Fund
PI: Hank Jann
Pathologic and Genetic Characterization of a Newly Recognized Developmental Neurologic Disorder of Gelbvieh Cattle
A mature Gelbvieh has been identified that has sired several calves that developed an idiopathic neurologic disorder during the first year of life. Semen will be collected and frozen from this bull in order to preserve the genetic material for future investigation. An adult cow that has produced sequentially affected offspring will be superovulated and inseminated with the collected semen. Embryos from this mating will subsequently be used to characterize the genetic determination of this disorder. Further investigation into the molecular genetics of the animals in question may be possible from the semen, ovaries, and frozen embryos.
Sponsor: Veterinary Medicine Research
PIs: Robert N. Streeter, Roger J. Panciera, and John Kirkpatrick
Investigation of Orbifloxacin in the Treatment of Experimental Canine Cystitis
One objective of this research is to investigate the feasibility of inducing cystitis with salicylic acid, ethanol, and dual bacterial infections with Proteus mirabilis and Pseudomonas aeruginosa. The second objective is to evaluate the efficacy of orbifloxacin in the treatment of cystitis as induced above.
Sponsor: Shering Plough Animal Health
PIs: Grant Turnwald, Mary Bowles, Ronald Welsh, and R. Jay Hoffman
T. Katz (Schering-Plough)
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