Methods have been developed that permit repetitive radiographic measurement of the lumbar intervertebral disc space in a rostral-caudal direction (width) in the anesthetized laboratory rabbit. Using isolated control discs and injured discs in which narrowing has been induced for chronic and acute periods, the widths of the lumbar intervertebral disc spaces determined ratio-graphically correlate with widths determined histologically (p less than 0.000, r = 0.75). Both an increase (widening) and a decrease (narrowing) in disc width were observed using radiography after different experimental treatments. Anesthesia and lower-body paralysis (an experimentally induced inability to bear weight on and to perceive a pinch stimulus in hind limbs) caused widening of the discs: anesthesia causing a general widening throughout the lumbar spine and lower-body paralysis causing a specific widening low in the lumbar spine. Both disc injection and piercing the disc with needles to recover nucleus pulposus material caused narrowing of the discs. Acridine-orange injection induced a narrowing accompanied by osteophytosis. Experimentally induced narrowing at L4-5 (the result of injury to the disc) resulted in narrowing also at L2-3. These findings are consistent with the hypothesis that in vivo disc-width size in the young rabbit depends on both the quantity of nucleus pulposus material and the force-generating activities of the adjacent spinal muscles, and that disc injury at one level stimulates narrowing at other levels.
Angiographic evaluation of impotent men revealed a frequent association between penile arterial disease and veno-occlusive insufficiency of the corpora cavernosa. In order to evaluate a possible cause-and-effect relationship, we investigated the competence of the cavernosal veno-occlusive mechanism in a canine model at various intervals after onset of cavernosal ischemia. In most dogs, the veno-occlusive mechanism could no longer be activated by papaverine after about 30 minutes of ischemia. If ischemia was relieved shortly thereafter, veno-occlusive competence returned after a further delay of one or two hours. The evidence suggests that veno-occlusive failure is not simply a hemodynamic consequence of loss of arterial inflow, but instead secondary to some ischemic injury. We conclude that arterial insufficiency may be one of the causes of cavernosal veno-occlusive insufficiency in humans.
The aim of this study was to determine the occurrence of EGUS and to quantify serum gastrin levels in jumping horses during competition season and interseason period. Forty jumping horses, competing at high level were randomly allocated into two groups, the Training Group: twenty jumping horses undergoing intense training and participating in competitions, and the Rest Group: twenty jumping horses in the interseason (resting period). The gastroscopic examinations and blood samples of the horses in the training group were performed 1-2 days following the competition while in the horses of the rest group, following 4 weeks of rest. The serum gastrin levels were measured at two different times: pre-feeding and two hours after feeding the horses (postprandial) by ELISA kit. Gastric lesion score data were compared by the Mann-Whitney U test (α= 0.05) and the mean gastrin values were compared between the groups and between the two moments by the paired tet tests, respectively (α= 0, 05). Squamous gastric ulcers were detected in 42.5% of all jumping horses examined independent of the period, competition season or interseason. Serum gastrin levels were significantly higher in the Training Group with no difference between pre-feeding and postprandial values.
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