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Biomedical subjects

J J Hoskinson

Publications and source records attributed to J J Hoskinson.

At least 19 recordsLinked to original sources
PubMed2001

Diagnostic imaging of lameness in small animals.

The demand for advanced diagnostic imaging procedures such as nuclear scintigraphy, ultrasonography, computed tomography, and magnetic resonance imaging has increased dramatically over the past 10 years. Veterinarians, seeking to improve their diagnostic capabilities and clients willing to pursue "best medicine" have driven this demand, resulting in installation of advanced imaging facilities at most academic and private referral practices. Knowledge of potential benefits of various modalities will allow the veterinarian to optimize his or her use of diagnostic imaging in his or her own practice or in a referral practice.

Animals↗
PubMed2000

Effects of external thermal manipulation on laminar temperature and perfusion scintigraphy of the equine digit.

AIMS: To assess the effects of external thermal manipulation on the soft-tissue and vascular perfusion of the equine digit using nuclear scintigraphy and documented tissue temperatures. METHODS: Six horses were used in a randomised crossover design. Each horse was treated with external heat (47 degrees C) or external cold (4 degrees C) applied to a digit for 30 minutes. The opposite front foot was untreated and used for control measurements. Nuclear scintigraphy was performed before, during, and after therapy to assess vascular and soft-tissue perfusion to the digit in response to therapy. Dorsal hoof wall laminar-tissue temperatures were recorded before, during, and after therapy using a thermistor. RESULTS: Treatment with topical cold therapy significantly decreased soft-tissue perfusion of the digit to 80.5% of the pre-cooled values. Conversely, the application of external heat significantly increased soft-tissue perfusion of the digit 25.1% above the pre-heated values. Vascular perfusion showed similar, but not statistically significant trends. External cold application to the digit caused a significant mean decrease in laminar-tissue temperatures of 11.6 degrees C during therapy, while external heat application to the digit caused a significant mean increase in laminar-tissue temperatures of 3.9 degrees C. CONCLUSION: The external application of heat and cold to the normal equine foot could effectively alter soft-tissue perfusion and laminar-tissue temperatures within 30 minutes of treatment. The application of hot water and ice water to the digit was a safe, well-tolerated, and economical therapy. CLINICAL RELEVANCE: Cooling the foot could decrease enzymatic reactions associated with laminitis, and warming could increase local perfusion when desired.

Journal Article↗
PubMed1999

Pulmonary distribution of aerosolized technetium Tc 99m pentetate after administration of a single dose of aerosolized albuterol sulfate in horses with recurrent airway obstruction.

OBJECTIVE: To determine whether pulmonary distribution of aerosolized technetium Tc 99m pentetate is improved after inhalation of a single dose of albuterol sulfate in horses susceptible to recurrent airway obstruction (heaves). ANIMALS: 6 horses with heaves and 4 horses with normal respiratory tract function. PROCEDURE: Images were obtained during ventilation of horses at baseline (maximal change in pleural pressure during tidal breathing [deltaPpImax] >15 cm H2O) and after aerosolized albuterol sulfate (360 microg) administration, with a 24-hour washout period between experiments. The deltaPpImax was determined prior to the baseline scan, prior to albuterol sulfate administration, and 5 minutes after albuterol sulfate administration. Images were assessed by visual inspection (semi-quantitative scoring system) and histogram analysis. RESULTS: Images obtained from horses with heaves had nonuniform pulmonary distribution of radionuclide characterized by poor penetration in peripheral lung fields and excess deposition in large airways. Histogram analysis of images of the caudal portions of the lungs revealed nonuniform radionuclide deposition in horses with heaves and uniform radionuclide deposition in control horses. CONCLUSION: Administration of a single dose of aerosolized albuterol sulfate improved pulmonary distribution of aerosolized radiolabeled pentetate suspension in horses with heaves but did not alter pulmonary distribution in clinically normal horses. CLINICAL RELEVANCE: Precedent bronchodilator administration may improve pulmonary distribution of aerosolized, surface-active anti-inflammatory preparations.

Administration, Inhalation↗
PubMed1999

Scintigraphic evaluation of dogs with acute synovitis after treatment with glucosamine hydrochloride and chondroitin sulfate.

OBJECTIVE: To evaluate the effects of orally administered glucosamine hydrochloride (GlAm)-chondroitin sulfate (CS) and GlAm-CS-S-adenosyl-L-methionine (SAMe) on chemically induced synovitis in the radiocarpal joint of dogs. ANIMALS: 32 adult mixed-breed dogs. PROCEDURE: For 21 days, all dogs received a sham capsule (3 groups) or GlAm-CS (prior treatment group) in a double-blinded study. Unilateral carpal synovitis was induced by injecting the right radiocarpal joint with chymopapain and the left radiocarpal joint (control joint) with saline (0.9% NaCl) solution. Joints were injected on alternate days for 3 injections. After induction of synovitis, 2 groups receiving sham treatment were given GlAm-CS or GlAm-CS-SAMe. Another group continued to receive sham capsules (control group). Joint inflammation was quantified, using nuclear scintigraphy, before injection of joints and days 13, 20, 27, 34, 41, and 48 after injection. Lameness evaluations were performed daily. RESULTS: Dogs given GlAm-CS before induction of synovitis had significantly less scintigraphic activity in the soft-tissue phase 48 days after joint injection, significantly less uptake in the bone phase 41 and 48 days after joint injection, and significantly lower lameness scores on days 12 to 19, 23, and 24 after injection, compared with other groups. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of results of this study suggest that prior treatment with GlAm-CS for 21 days had a protective effect against chemically induced synovitis and associated bone remodeling. Prior treatment with GlAm-CS also reduced lameness in dogs with induced synovitis.

Administration, Oral↗
PubMed1998

Scintigraphic assessment of gastric emptying of canned and dry diets in healthy cats.

OBJECTIVE: To characterize factors that affect solid-phase gastric emptying in healthy cats by use of nuclear scintigraphy and to assess differences in emptying patterns of dry and canned diets. ANIMALS: 20 healthy cats. PROCEDURE: 2 groups of 10 cats each were fed dry or canned diet for at least 2 weeks before scintigraphy was done. Diets were labeled with 99mTc-disofenin. After ingestion of labeled meals, scintigraphic images were obtained at 0, 15, 30, 45, and 60 minutes, then every 30 minutes to 6 hours. Gastric emptying scans were obtained 3 times for each cat for each diet, in a complete crossover design. The T90, T50, and T20 (times when 90, 50, and 20% of initial meal activity remained in the stomach, respectively) were derived from gastric emptying curves fit to nonlinear models. A mixed models approach was used for data analysis. RESULTS: Gastric emptying was well described by a nonlinear model. Meal size, water intake, and diet type significantly (P < 0.05) effected gastric emptying. The T90, T50, and T20 increased with meal size, regardless of diet type or water intake. Gastric emptying of a dry diet meal took significantly (P < 0.05) longer than that of an isocaloric meal of canned diet, except when meal size was small. Differences in gastric emptying of dry and canned diets varied with the phase (T90 vs T50 vs T20) of emptying. CONCLUSION: Water intake, meal size, and diet type significantly influence gastric emptying in healthy cats, and these factors must be considered in analysis of gastric emptying data.

Animal Feed↗
PubMed1998

Effect of percutaneous endoscopic gastrostomy on gastric emptying in clinically normal cats.

OBJECTIVE: To assess the effect of percutaneous endoscopic gastrostomy (PEG) tube placement on gastric emptying in clinically normal cats. ANIMALS: 8 healthy adult 3- to 5-year-old cats. PROCEDURE: Cats were accommodated to the diet for 2 weeks prior to scintigraphy. Caloric needs were divided into 3 feedings/d. Food was withheld for 24 hours after tube placement, then was fed as a third of the caloric needs on day 1, two-thirds on day 2, and full caloric requirements thereafter. Gastric emptying was measured via nuclear scintigraphy. Labeled meals contained 111 MBq (3 mCi) of 99mTc-labeled disofenin. Sixty-second ventral scintigraphic images were acquired immediately, every 20 minutes for the first hour, then every 30 minutes for 4 hours after feeding. Each cat was evaluated 3 times prior to PEG tube placement. Cats were anesthetized, and 16-F mushroom-tipped Pezzar gastrostomy tubes were placed, using a video endoscope. Scintigraphy was repeated on days 1, 4, 7, 11, 14, and 21 after PEG tube placement. RESULTS: Gastric emptying was faster with a PEG tube in place. Percentage of retained gastric activity was significantly lower after PEG for 150, 180, 210, and 240 minutes versus time before PEG tube placement. CONCLUSION: Placement of a PEG tube does not delay gastric emptying in clinically normal cats. CLINICAL RELEVANCE: Gastric retention of food, vomiting, and aspiration pneumonia after PEG tube placement may not be related to delayed gastric emptying.

Animals↗
PubMed1997

Advanced diagnostic imaging modalities available at the referral center.

While many equine diagnostic imaging procedures can be done in field, some procedures require specialized facilities, equipment or expertise which are generally only available in referral or specialty practices. As client awareness of the availability and advantages of these diagnostic procedures increases, veterinarians are faced with the increasing opportunity to utilize these services to provide optimal patient care. A working knowledge of the value and limitations of these methods is required to help guide veterinarians and clients in the selection of additional, and sometimes costly, diagnostic tests.

Animals↗
PubMed1997

Improved osseointeraction of calcium phosphate-coated external fixation pins. Studies in calves.

We investigated osseointeraction of solution-precipitated calcium phosphate (SPCP)-coated transfixation pins used in external skeletal fixation of a calf stable fracture model. One group (SPCP) received centrally-threaded transfixation pins which had SPCP coating; the other group (control) received identical, but not coated, pins. Radiographs were obtained 1 and 40 days after surgery and examined for evidence of osteolysis. Bone phase 99mTc-MDP studies were performed 6 and 28 days after surgery. Calves were killed 40 days after surgery and mechanical tests performed. Dual-energy x-ray absorptiometry (DEXA) and histomorphometric analyses were done. A smaller proportion of SPCP pins (5/24) had evidence of discharge during the study compared with control pins (21/24). A smaller proportion of SPCP pins (4%) had radiographic evidence of osteolysis compared with control pins (42%). Uptake of 99mTc-MDP was similar for SPCP and control calves. Uptake was significantly greater in bone segments showing radiographic evidence of osteolysis than in bone segments not having osteolysis. Yield stress (MPa) for axial displacement was similar in the treatment groups. Bone mineral density was less in SPCP pins. Affinity index and interface histologic score were greater and osteoclastic index less in SPCP calves. Coating of transfixation pins with solution-precipitated calcium phosphate improved the osseointeraction of pin and bone during this 40-day study.

Absorptiometry, Photon↗
PubMed1997

Characterization of anatomic communications among the antebrachiocarpal, middle carpal, and carpometacarpal joints in cattle, using intra-articular latex, positive-contrast arthrography, and fluoroscopy.

OBJECTIVE: To evaluate the frequency and sites of communication among the antebrachiocarpal, middle carpal, and carpometacarpal joints in cattle. ANIMALS: 137 limbs were obtained from 72 fresh bovine cadavers submitted for necropsy because of problems unrelated to the carpus. PROCEDURE: 1 of the 3 injection sites was randomly assigned to both carpi of each ox, and a mixture of latex and barium sulfate was injected into the joint. Communication between 2 or more joints was determined by the presence of latex and contrast material in a joint adjacent to the injected joint by examination of frozen sections, positive-contrast arthrography, and fluoroscopy. RESULTS: Communication existed among the 3 joints in 18 specimens (13.1%). The middle carpal joint and the carpometacarpal joint always communicated. The antebrachiocarpal joint communicated with the middle carpal joint between the ulnar and intermediate carpal bones. The middle carpal and carpometacarpal joints always communicated between the fourth and fused second and third carpal bones. In a few specimens, additional sites of communication were identified at the palmar aspect of the fourth carpal bone and the fused second and third carpal bones. CONCLUSIONS AND CLINICAL RELEVANCE: Individual anatomic variation of the carpus in cattle should be considered when diagnostic or treatment protocols are established.

Animals↗
PubMed1997

Evaluation of solid-phase labels for gastric emptying studies in cats.

UNLABELLED: Development of appropriate radiolabeled diets for solid-phase gastric emptying studies in experimental animals is important for testing the effects of disease, drugs, surgical procedures and stress. This study evaluates the in vitro and in vivo stability of various radiolabels in commercially available dry, extruded and canned cat foods. METHODS: Dry, extruded cat food was labeled with 99mTc-pertechnetate, 99mTc-sulfur colloid or 99mTc-disofenin. Canned cat food was labeled with 99mTc-Dowex resin beads, 99mTc-pertechnetate, 99mTc-sulfur colloid or 99mTc-disofenin. A sample of each labeled diet and 99mTc-sulfur colloid-labeled egg was digested in water, gastric juice, intestinal juice or gastric juice followed by intestinal juice. The samples were centrifuged and the activity in the samples counted before and after removal of the supernatant. Based on in vitro results, three labeled diets were fed to 10-12 cats for in vivo testing. RESULTS: 99mTc-Dowex beads had the best labeling efficiency in vitro, but were not stable in vivo, resulting in unacceptable levels of circulating 99mTc. Technetium-99m-disofenin labeling resulted in in vitro percent solid-phase retention of 92.5% and 89.5% in water and gastric juice, respectively, for dry food and 86% and 94.9% in water and gastric juice, respectively, for canned food. CONCLUSION: Technetium-99m-disofenin is a suitable label for solidphase gastric emptying studies using commercially available cat foods.

Administration, Oral↗
PubMed1997

Characterization of anatomic communications of the fetlock in cattle, using intra-articular latex injection and positive-contrast arthrography.

OBJECTIVE: To evaluate the frequency and sites of communication between the lateral and medial synovial sacs of the metatarsophalangeal or metacarpophalangeal joints in cattle. ANIMALS: 188 limbs were obtained from 55 fresh bovine cadavers submitted for necropsy because of problems unrelated to the fetlocks. PROCEDURE: In each ox, lateral or medial synovial sacs of each fetlock were randomly assigned. Joints were injected with a mixture of latex and barium sulfate. Communication between 2 joints was determined by presence of latex and contrast material in a joint adjacent to the injected joint by examining frozen sections and use of positive-contrast arthrography. RESULTS: Communication between the 2 synovial sacs existed in 186 of 188 (98.9%) specimens. The communication site between lateral and medial synovial sacs was located at the level of the proximal sesamoid bones, between the distal aspect of the interdigital band of the axial branch of the interosseus muscle and the metacarpal or metatarsal bone. CONCLUSIONS AND CLINICAL RELEVANCE: Although communication between the lateral and medial synovial sacs did not exist in 2 specimens, the fetlock in cattle can be treated as 1 compartment.

Animals↗
PubMed1996

Use of Doppler ultrasonography and positive-contrast corpus cavernosography to evaluate a persistent penile hematoma in a bull.

A 32-month-old Angus bull was evaluated because of a 2-month history of a slowly progressive swelling located cranial to the base of the scrotum. The mass was 8 x 8 x 6 cm, and was causing phimosis. The mass was determined to be a penile hematoma on the basis of results of ultrasonography and exploratory surgery. Surgical evacuation was not performed initially because the deep fascia of the penis was intact and the hematoma was small; however, the hematoma enlarged slowly during the ensuring 2 months, despite sexual rest and isolation from other livestock. Doppler ultrasonography and positive-contrast corpus cavernosography were performed, and the hematoma was seen as a space-occupying mass within the corpus cavernosum penis; vascular anomalies were not found. The penile hematoma was surgically excised, and the bull was isolated for 60 days. At follow-up, the owner indicated that the bull had returned to pasture-breeding soundness and was still being used 2 years after surgery. The small penile hematoma in this bull was unusual in that it did not respond to medical treatment. Surgical treatment was apparently curative, even though surgery was not performed until 4 months after the hematoma was first detected.

Animals↗
PubMed1996

Characterization of anatomic communications between the femoropatellar joint and lateral and medial femorotibial joints in cattle, using intra-articular latex, positive contrast arthrography, and fluoroscopy.

OBJECTIVE: To evaluate the frequency of communication between the lateral and medial femorotibial joints and the femoropatellar joint in cattle. DESIGN: 1 of 3 injection sites was randomly assigned to each ox. ANIMALS: 102 limbs were obtained from 55 fresh bovine cadavers presented for necropsy with problems unrelated to the stifle. PROCEDURE: The joints were injected with a mixture of latex and barium sulfate. Communication between 2 or more joints was determined by the presence of latex and contrast material in a joint adjacent to the injected joint by examining frozen sections and positive-contrast arthrography. RESULTS: Communication between the 3 joints was present in 58 (56.9%) limbs. The femoropatellar and the medial femorotibial joints always communicated. Thirteen of 38 (34.2%) specimens injected in the lateral femorotibial joint did not communicate with the 2 other joints. The femoropatellar joint communicated with the lateral and medial femorotibial joints on the distal abaxial aspect of the trochlear ridge. CONCLUSION: Individual anatomic variation of the stifle in cattle should be considered when diagnostic or treatment protocols are established. CLINICAL RELEVANCE: The lateral femorotibial joint should be treated separately because it does not consistently communicate with the femoropatellar or medial femorotibial joint.

Animals↗
PubMed1994

Acute effects of perineural administration of sodium hyaluronate on palmar digital neurectomy sites in horses.

Biaxial palmar digital neurectomy of all limbs was performed on 6 mixed-breed castrated adult male horses, using a standard guillotine method. Using a Teflon catheter, 20 mg (2 ml) of sodium hyaluronate (group 1), 2 ml of phosphate-buffered saline solution (group 2), or catheter placement with no infusion (group 3) was applied to 4 (group 1) or 2 (groups 2 and 3) of 8 incisions/horse. Treatments were administered after closure of the neurectomy incision, and the catheter was removed. Horses were evaluated daily for 1 week, then weekly over a 9-week period for evidence of lameness, swelling, and ultrasonographic changes. On week 9, horses were euthanatized and neurectomy sites were removed en bloc for histologic evaluation of axonal regrowth, inflammation, and fibrosis. Neither lameness nor sign of painful neuroma was observed clinically in any of the horses. Neurectomy eliminated cutaneous heel sensation in all limbs for the duration of the study. Swelling was evident at all neurectomy sites. There were no significant differences between treatment sites for measurement of pastern circumference or ultrasonographic evaluation of incisional swelling. Foci of ultrasonographic hyperechogenicity increased over time, but there was no significant difference in hyperechogenicity between treatment groups. Histologic evidence of neuroma formation was observed at all sites. Morphometric assessment of neuroma cross-sectional areas revealed no significant difference between the groups, as did subjective histologic assessment of neuroma density and fibrous tissue content.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1994

Development of an experimental model of hypothyroidism in cockatiels (Nymphicus hollandicus).

Hypothyroidism is a possible predisposing factor in a number of disorders of companion psittacine birds. We developed and validated a thyroid-stimulating hormone (TSH) response testing protocol for cockatiels (Nymphicus hollandicus), using 0.1 IU of TSH/bird given IM, with blood sample collection at 0 and 6 hours after TSH, and a commercial radioimmunoassay for thyroxine (T4). This protocol was used to document a seasonal sex difference in stimulated T4 values--females responded with higher T4 values than those in males in summer--and a stress-induced depression of baseline T4 values was detected in a group of cockatiels with normal TSH response. An experimental model for mature-onset hypothyroidism in cockatiels was created by radiothyroidectomizing cockatiels with 3.7 MBq (100 microCi) of 131I/bird given IV. Induction of the hypothyroid state was confirmed by baseline T4 concentration, TSH response test results, thyroid pertechnetate scintigraphy, and gross and microscopic examinations. Classical signs of hypothyroidism (eg, hypercholesterolemia, obesity, poor feathering) were lacking or mild at 48 days after thyroid ablation.

Animals↗