COLLAGENASE CHEMONUCLEOLYSIS—A LONG TERM RADIOGRAPHIC STUDY IN NORMAL DOGS

Five clinically normal five year old dogs were used in this study. From a randomised table inter ver tebral discs were each injected with either collagenase or calcium chloride diluent. The surgically exposed cervical discs were injected with 50 units whereas thoracic and lumbar discs were injected under fluoroscopic guidance with 100 units of the enzyme. Postinjection radiographs revealed significant (p ≤ .05) disc space narrowing in enzyme injected discs. The cervical discs had the highest frequency of radiographic narrowing (87%) followed by the thoracic (70%) and lumbar (53%) discs. Spondylosis deformans developed at the sites of cervical enzyme injections. None of the dogs had neurologic abnormalities one year postinjection.     

Parosteal osteosarcoma of the mandible in a dog

A mandibular parosteal osteosarcoma was diagnosed in a 7-year-old Collie with prolapse of the third eyelid. Diagnosis was made by histologic evaluation of a mass removed by surgical excision. The dog was euthanatized because of local recurrence of the tumor, with metastasis to the lungs. Parosteal osteosarcomas are rarely reported in dogs and usually involve long bones in human beings.     

Black polyethylene mulch improves growth of plantation-grown loblolly pine and yellow-poplar

The effects of mulching with perforated black plastic, in combination with fertilization and induced mycorrhizal symbioses, on the growth of loblolly pine (Pinus taeda L.) and yellow-poplar (Liriodendron tulipifera L.) were studied in a plantation under intensive, short rotation management. Mulching effects on soil temperature were also examined in order to assess the potential influence of this treatment on temperature-dependent processes in soils affecting tree growth. Mulching significantly increased height and stem diameter growth of both species, attributable largely to improved water relations resulting from diminished soil surface evaporation and elimination of transpirational losses from competing vegetation. Mulching effects on soil temperature were insufficient to contribute substantially to the growth response exhibited by mulched trees. Multiple applications of urea-N promoted enhanced growth in both loblolly pine and yellow-poplar, an effect accentuated by mulching, but the field performance of trees inoculated in the nursery with selected mycorrhizal fungi was poor relative to that of the other treatments investigated.     

A technique for repair of femoral capital epiphyseal fractures in the dog

A new method for repair of femoral capital epiphyseal fractures in the immature dog is described. The technique employs two small AO/ASIF cortical screws inserted in lag fashion from the articular surface into the femoral neck. The screw heads are countersunk, so as not to project from the articular cartilage of the femoral epiphyseal fragment, While this is an early report it is hoped that it will prompt the use of the technique by others so that its long term assessment may be more rapidly determined than by one clinic working alone.     

Clinical evaluation of the effects of immobilization followed by remobilization and exercise on the metacarpophalangeal joint in horses

OBJECTIVES: To evaluate clinical effects of immobilization followed by remobilization and exercise on the metacarpophalangeal joint (MPJ) in horses. ANIMALS: 5 healthy horses. PROCEDURE: After lameness, radiographic, and force plate examinations to determine musculoskeletal health, 1 forelimb of each horse was immobilized in a fiberglass cast for 7 weeks, followed by cast removal and increasing amounts of exercise, beginning with hand-walking and ending with treadmill exercise. Lameness examination, arthrocentesis of both MPJ, single-emulsion radiographic examination, nuclear scintigraphic examination, ground-reaction force-plate analysis, and computed tomographic examination were done at various times during the study. RESULTS: All horses were lame in the immobilized MPJ after cast removal; lameness improved slightly with exercise. Force plate analysis revealed a significant difference in peak forces between immobilized and contralateral limbs 2 weeks after cast removal. Range of motion of the immobilized MPJ was significantly decreased, and joint circumference was significantly increased, compared with baseline values, during the exercise period. Osteopenia was subjectively detected in the immobilized limbs. Significant increase in the uptake of radionucleotide within bones of the immobilized MPJ after cast removal and at the end of the study were detected. Loss of mineral opacity, increased vascular channels in the subchondral bone, and thickening within the soft tissues of the immobilized MPJ were detected. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that 8 weeks of enforced exercise after 7 weeks of joint immobilization did not restore joint function or values for various joint measurements determined prior to immobilization.     

Influence of submergence and subsequent drainage on the partitioning and lability of added selenium fertilizers in a sulphur‐containing Fluvisol

We used an isotope dilution method to examine the time‐dependent changes in the partitioning and lability of selenium (Se) in a Sri Lankan rice soil after adding fertilizer with selenite (Se(IV)) and selenate (Se(VI)) (1 mg kg^?1) and incubation under anaerobic (submerged) (30 days) and subsequent aerobic (drained) conditions (7 days) in controlled reaction vessels mimicking rice paddy water management practices. The K_d (the ratio of sorbed ion to that in solution) values for Se(IV) were significantly (P≤ 0.001) larger than those for Se(VI) in all treatments and at all sampling times. The K_d values for Se(IV) and Se(VI) decreased significantly (P≤ 0.001) with time during the anaerobic and subsequent aerobic phases. Applied Se(IV) fertilizer was rapidly removed into non‐labile pools during the anaerobic phase (day 0 = 60% labile and day 14 = no labile Se), with no significant increase in the labile pool following short‐term aeration. The results suggest that the rapid decrease in Se(IV) lability may be caused by the strong non‐reversible (at least for 7 days) sorption of Se (IV). In contrast, applied Se(VI) fertilizer was 90% labile at 0 day and decreased during the anaerobic phase to 30% after 30 days. There was no significant change in the lability of Se(VI) following the short‐term aerobic phase following anaerobic conditions. These results indicate that Se(IV) would not be an effective pre‐planting fertilizer for rice production. Selenate is likely to be more effective, but losses to non‐labile forms during the submerged phase of rice production may mean that efficiency of pre‐planting Se(VI) fertilizer is also compromised.