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- Author or Editor: Murray K. Clayton x
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Abstract
Objective—To evaluate whether body size and anatomic site influence the quantity of bone microdamage in dogs without osteosarcoma (OS).
Sample Population—Pairs of radii were collected from 10 small dogs (< 15 kg) and 10 large dogs (> 25 kg).
Procedure—Specimens were stained in basic fuchsin for bone microdamage. Transverse sections were cut from each proximal and distal radial metaphysis at 15 and 85% of bone length. The following variables were determined for each region: mean microcrack length (CrLe, µm), microcrack density (CrDn, microcracks/mm2), microcrack surface density (CrSDn, µm/mm2), and estimated activation frequency (Acf, microcracks/mm2/y).
Results—Metaphyseal region did not significantly influence CrDn, CrLe, and CrSDn. The CrDn and CrSDn were influenced by body size, with microdamage being increased in large dogs, compared with small dogs. However, mean CrLe was not significantly influenced by body size. Acf significantly decreased with age and was significantly decreased in large dogs and in the distal radial metaphysis, compared with small dogs and the proximal radial metaphysis, respectively.
Conclusion and Clinical Relevance—Our data did not reveal an increase in microdamage or remodeling at the OS predilection site (ie, the distal metaphysis of the radius), suggesting that induction of microdamage and an associated increase in bone remodeling are unlikely to be an important risk factor for induction of OS. (Am J Vet Res 2002;63:896–899)
Summary
Bradycardia was documented in 12 cattle from which food had been withheld for 48 hours in preparation for general anesthesia and an elective surgical procedure. The heart rates decreased by a mean of 14 beats/min, and 4 cows had sinus arrhythmia. To evaluate this finding, the heart rates of 21 clinically normal cattle were evaluated before and after food was withheld for 48 hours. Bradycardia developed in all of the clinically normal cattle, with the mean decrease in heart rate being 23 beats/min. Five of the clinically normal cows developed sinus arrhythmia. It was concluded that bradycardia and sinus arrhythmia in cattle are associated with deprivation of food.
Abstract
Objective
To measure and compare values of interleukin 6 (IL-6), tumor necrosis factor (TNF), and nitric oxide (NO) metabolites in synovial fluid from canine joints with osteoarthritis (OA) secondary to naturally acquired cranial cruciate ligament (CCL) rupture and experimental CCL transection.
Animals
57 dogs (clinical group) with OA secondary to CCL rupture; 5 dogs (experimental group) with OA secondary to CCL transection; 19 control dogs with normal joints.
Procedure
Joints were radiographed and graded for severity of OA. Synovial fluid was collected from dogs: at surgery from the clinical group, at 90 days after surgery from the experimental group, and at necropsy from the control group. Activities of IL-6 and TNF, as well as concentration of the NO metabolites (NO2 −/NO3 −) were measured, and results were reported as mean ± SEM.
Results
IL-6 activity in dogs of the clinical (290 ± 40 U/ml) and experimental (494 ± 165 U/ml) groups was greater than that in control dogs (6 ± 1.6 U/ml; P < 0.05). The TNF values in dogs of the clinical (3.0 ± 0.5 pg/ml) and experimental (2.0 ± 0.9 pg/ml) groups were lower than those in control dogs (8.6 ± 2.3 pg/ml; P < 0.05). The IL-6 values were negatively associated with radiographic score of OA and were positively associated with age (R 2 = 26.5%, P < 0.05).
Conclusion
Dogs with OA secondary to naturally acquired CCL rupture and experimental CCL transection had significantly different alterations in synovial fluid IL-6 and TNF values. The decrease in IL-6 activity with advancing OA was independent of the increase in IL-6 activity with aging.
Clinical Relevance
IL-6 and TNF may be involved in pathogenesis of OA secondary to naturally acquired and experimentally induced CCL rupture. (Am J Vet Res 1997;58:1027–1032)
