Use of the holmium yttrium aluminum garnet laser for percutaneous thoracolumbar intervertebral disk ablation in dogs.

OBJECTIVE-To evaluate a laser ablation-technique for treatment of thoracolumbar intervertebral disk disease in dogs. DESIGN-Prospective case series. ANIMALS-33 dogs with signs of recurrent back pain associated with intervertebral disk disease after the initial episode had been managed conservatively for a minimum of 2 weeks. PROCEDURE-Spinal needles were placed percutaneously through the annulus fibroses to permit delivery of an optical fiber into the nucleus pulposes of thoracolumbar intervertebral disks T10-11 through L3-4. Fluoroscopy was used to guide needle placement. Holmium yttrium aluminum garnet laser energy then was used to ablate the contents of each selected intervertebral disk. Intervals from time of treatment to time of assessment ranged from 3 to 114 weeks. RESULTS-All dogs recovered without complication. Results of follow-up radiography and histologic evaluation indicated that percutaneous holmium yttrium aluminum garnet laser ablation reduces the volume of nucleus pulposus in treated disks. CLINICAL IMPLICATIONS-Used as a clinical treatment and prophylactically, this minimally invasive procedure should prevent further extrusion of partially herniated disks and should reduce the chances of subsequent herniation of disks at other treatment sites.

Advertising wearout in the Transport Accident Commission road safety campaigns.

This paper uses a varying coefficient regression model to investigate whether there is any significant advertising wearout in the Transport Accident Commission (TAC) road safety campaigns on Victorian television. The results suggest that there is some evidence that the effectiveness of the campaigns may be declining with increased exposure.

Canine hip dysplasia: clinical signs and physical diagnosis.

Clinical signs of hip dysplasia include lameness, gait abnormalities, reluctance to exercise, and pelvic limb muscle atrophy with compensatory shoulder muscle hypertrophy. Because these clinical signs are not pathognomonic for CHD, a thorough orthopedic and neurologic examination is recommended for all patients with suspected CHD. Specific maneuvers, including the Barlow, Ortolani, and Barden's signs are useful to characterize the degree of coxofemoral laxity, both as screening tools in young puppies and as diagnostic aids in clinically lame dogs. None of the signs are definitive diagnostic tests for CHD, but they should be performed as sequential maneuvers in the veterinarian's workup for suspected CHD. Pelvic radiography is mandatory to definitively diagnose CHD but should not be the first step in the workup, because other diagnoses may be missed or concurrent conditions may coexist with dysplasia.

Radiographic and histologic effects of chondroitinase ABC on normal canine lumbar intervertebral disc.

Twelve dogs were divided into two equal groups and given lumbar intradiscal injections of 10, 50, or 100 U/ml of chondroitinase ABC reconstituted in sodium acetate buffer. Radiographs of the lumbar spine were made before and after surgery in both groups. Additional films were made at 5 days after surgery in Group I and at 7, 14, and 21 days after surgery in Group II. All spaces injected with 50 or 100 U/ml chondroitinase ABC demonstrated significant radiographic narrowing in both groups compared with uninjected control and buffer injected discs (P less than 0.001). Discs injected with 10 U/ml of chondroitinase ABC showed increased narrowing over time from 7 to 21 days (P less than 0.05). A zone of safranin O depletion was present in the ventral anulus fibrosus adjacent to the nucleus pulposus in all treated discs, indicating proteoglycan loss. All histologic effects of chondroitinase ABC were confined to intervertebral disc tissues. Chondroitinase ABC appears to be effective for chemonucleolysis in dogs.

Isolation of Fasciola hepatica metacercariae by density gradients.

Fasciola hepatica metacercariae were purified in high yield, removing contaminating cyst walls and plant material by step gradients consisting of 10 ml of 60% Percoll (density = 1.08 g ml-1) and 10 ml of 50% Metrizamide (density = 1.25 g ml-1). Greater than 90% of the metacercariae applied to the density gradients were recovered. These isolated metacercariae had an in vitro excystment rate of greater than 80%, which was the same excystment rate as metacercariae not subjected to density gradient centrifugation.