Articles: injury.
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Clinical biomechanics · Jan 1997
Precision measurement of disc height, vertebral height and sagittal plane displacement from lateral radiographic views of the lumbar spine.
OBJECTIVE.: To compile a database of disc height, vertebral height and sagittal plane displacement from lateral radiographic views of the lumbar spine, valid for male and female subjects in the age range 16-57 years. The protocols used to measure these parameters compensate for distortion in central projection, off-centre position, axial rotation and lateral tilt of the spine as well as for variation in radiographic magnification and stature. STUDY DESIGN.: The study comprised designing and testing of measurement protocols, together with subsequent data collection from archive radiographs. ⋯ On average, height of lumbar vertebrae is larger in females than in males; height of lumbar discs is larger in males than in females and shows a minute dependence on age in males; in both genders, sagittal plane displacement increases, but only by a small amount, with age. CONCLUSIONS.: The new measurement protocols for disc height, vertebral height and sagittal plane displacement, together with the database of normative age-related values, permit quantitative assessment of the prevalence of pathological morphological changes in the human lumbar spine. The new method and the database will serve to explore the effect of potentially detrimental influences such as high spinal loading and to provide quantitative documentation of existing injury to vertebrae and discs in individual cases.
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The dramatic decline in mortality related to cardiac surgery has resulted in over 330,000 surgeries involving cardiopulmonary bypass (CPB) being performed yearly in the United States. Although few patients die as a result of cardiac surgery, over two thirds of the patients demonstrate evidence of acute neuropsychological dysfunction postoperatively. The potential mechanisms contributing to post-CPB neuropsychological deficits are many, but two major inter-related etiologic factors, hypo-perfusion and emboli, are suggested as the probable culprits. ⋯ Conversely, if hypoperfusion is the cause of the injury, then decreasing brain blood flow to minimize embolic delivery would increase the likelihood of perfusion injury. By monitoring the carotid arteries of patients undergoing coronary artery bypass graft surgery, we have determined the frequency and quantity of embolic signals that occur during CPB. Although we have not been able to determine the nature of the embolus, gaseous or solid, we have demonstrated a relationship between the overall embolic load and the probability of having NP dysfunction. (ECHOCARDIOGRAPHY, Volume 13, September 1996)
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Restor Neurol Neuros · Jan 1994
Continuous low amplitude direct current stimulation of the crushed peripheral nerve accelerates the early recovery of choline acetyltransferase but not of acetylcholinesterase activity in fast and slow muscles.
We investigated if continuous 1 µA direct current stimulation of the injured nerve, with the cathode electrode at the distal end of the nerve crush injury (cathode stimulation), accelerated the recovery of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity in transiently denervated extensor digitorum longus (EDL) and soleus (SOL) rat muscles. ChAT is a specific marker of cholinergic nerve terminals and may reflect axon ingrowth, and AChE reflects the re-establishment of neuromuscular junctions and recovery of muscle activity. Compared to sham operated animals, the cathode (CA) stimulated rats had a statistically significant larger ChAT activity in the EDL and SOL muscles on days 12 and 14 after nerve crush (P < 0.01, n = 6). ⋯ It is more likely that the higher ChAT activity observed after cathode stimulation indicates a higher ChAT content in regenerating motor nerve endings, rather than a greater number of motor axons entering the muscles. It seems possible that cathode stimulation increased ChAT axonal transport, causing the early increase of ChAT content in the nerve endings. This raises the possibility that the axon transport and subsequent secretion of a trophic factor(s) from the nerve to the reinnervated muscle are enhanced as well, thus shortening the overall time of muscle force recovery in the absence of an appreciable acceleration of recovery of the neuromuscular transmission.
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J Neurosurg Anesthesiol · Dec 1991
A comparison of the cerebral and hemodynamic effects of mannitol and hypertonic saline in a rabbit model of acute cryogenic brain injury.
There has recently been an increased interest in the use of hypertonic saline solutions in the fluid resuscitation of trauma victims and patients with uncontrollable intracranial hypertension. In this study, the cerebral and hemodynamic effects of 3.2% hypertonic saline solution were compared with those of an equiosmolar (20%) mannitol solution or 0.9% saline in a rabbit model of acute cryogenic brain injury. Forty-five minutes following the creation of a left hemispheric cryogenic brain lesion, equal volumes (10 ml/kg) of hypertonic saline, 0.9% saline, or mannitol were infused over a 5-min period. ⋯ However, there appeared to be no significant differences in ICP between animals receiving mannitol or hypertonic saline at any time point following infusion of solutions. We conclude that following acute cryogenic brain injury, infusions of equal volumes of equiosmolar solutions of hypertonic saline or mannitol will transiently reduce ICP as compared to equal volumes of normal saline. However, hypertonic saline is not superior to mannitol in its ability to reduce ICP in this model of intracranial hypertension.