Objective—To investigate the biomechanical behavior
of the lumbosacral disk under compressive load in
dogs, using pressure profilometry, and to investigate
the relationship between pressure profile features
and background and disease variables.
Sample Population—23 lumbosacral disks and adjacent
vertebrae harvested from medium and large
Procedure—A 1.3-mm unidirectional needle-mounted
pressure transducer was inserted into the disk in a
ventral-to-dorsal manner while the disk was loaded in
compression by a materials testing machine.
Withdrawal of the transducer resulted in a pressure
profile for cranial and lateral stress. Pressure profiles
were analyzed, and relationships to age and gross evidence
of degeneration were investigated.
Results—There was a moderate positive correlation
between age and degree of nuclear degeneration
(rs = 0.420, P = 0.046), but no relationship between
age and mean nuclear pressure was detected. Mean
nuclear pressure correlated negatively with severity of
degenerative changes in the nucleus pulposus.
Receiver operator characteristic curves to evaluate
mean nuclear pressure as a diagnostic test for nuclear
degeneration revealed a sensitivity and specificity of
82 and 83%, respectively. In addition, age was moderately
correlated with the magnitude of stress peaks
(rs = –0.571, P = 0.004). Stress peaks were not related
to the severity of nuclear degeneration.
Conclusions and Clinical Relevance—Determination
of the mean nuclear pressure by disk profilometry
provides information on the severity of lumbosacral
disk degeneration with a high degree of sensitivity
and specificity. The magnitude of single stress
peaks within the dorsal annulus fibrosus is correlated
with age and may not necessarily reflect advancing
degeneration. (Am J Vet Res 2001;62:1734–1739)
Objective—To evaluate whether administering a tart cherry juice blend (TCJB) prior to exercise would reduce skeletal and cardiac muscle damage by decreasing the inflammatory and oxidative stress response to exercise in horses.
Procedures—Horses were randomly allocated into 2 groups in a crossover study with a 2-week washout period and orally administered either TCJB or a placebo solution (1.42 L, twice daily) in a double-masked protocol for 2 weeks prior to a stepwise incremental exercise protocol. Horses were tested for serum activities of creatine kinase and aspartate aminotransferase (AST) and concentrations of cardiac troponin I (cTnI), thiobarbituric acid reactive substances (TBARS; an indicator of oxidative stress), and serum amyloid A (SAA; an indicator of inflammation). To ensure that treatment would not result in positive results of an equine drug-screening protocol, serum samples obtained from each horse prior to and after 2 weeks of administration of TCJB or the placebo solution were tested.
Results—All horses had negative results of drug screening at both sample times. The exercise protocol resulted in a significant increase in TBARS concentration, SAA concentration, and serum AST activity in all horses. Administration of TCJB or placebo solution was not associated with an effect on malondialdehyde or SAA concentrations. However, administration of TCJB was associated with less serum activity of AST, compared with administration of placebo solution.
Conclusions and Clinical Relevance—Administration of TCJB may diminish muscle damage induced by exercise.