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At least 19 recordsLinked to original sources

PubMed1992

Effects of distraction on physiologic integrity of the spinal cord, spinal cord blood flow, and clinical status.

The authors determined the effects of distraction of the spine on physiologic integrity of the spinal cord using neurogenic motor evoked potentials (NMEPs), somatosensory evoked potentials (SEPs), spinal cord blood flow measurements, and clinical status in nine hogs. Spinal cord blood flow was measured after each level of distraction using the hydrogen washout technique. The results indicated that blood flow of at least 65% of baseline was required to maintain physiologic integrity of the spinal cord, and that a decrease of blood flow to 12% of baseline was associated with paraplegia. Neurogenic motor evoked potentials always correlated with the animal's postsurgical clinical status, whereas the SEP was falsely negative in one animal.

Animals↗

PubMed1977

The mechanism of spinal cord cavitation following spinal cord transection. Part 3: Delayed grafting with and without spinal cord retransection.

Cavitation adjacent to transection of spinal cords can be successfully eliminated by a second operation 1 week after the initial spinal cord transection. The second operation consists of removal of the necrotic spinal cord tissue, thus producing a gap. Segments of autogenous sciatic nerve are inserted into the gap between the spinal cord stumps. If the spinal cord is injured by retransection at the second operation, cavitation again occurs in the spinal cord stumps resulting in separation of the nerve grafts from the spinal cord. The results of the present experiments support the concept that lysosomal spinal cord autotomy, which causes spinal cord cavitation, is a self-limiting process and that once the spinal cord has completed the autotomy, the process will not occur again unless the spinal cord is agiain traumatized.

Animals↗

PubMed1975

[Morphologic and cytophotometric indices of the state of the neurons of the spinal cord and spinal cord ganglia following exposure to gravitational stress].

The work presents data on the state of the neurons of the spinal ganglia and the spinal cord of the lumbosacral part in 96 cats subjected to single stresses (10g) and repeated ones (6g). The material was stained with thionin after Nissl. RNA was detected after Einarson. Photometry of the sections was made in MUP.5. Morphological changes were shown to be more pronounced in sensory cells. The method of cytophotometry established the increase by 25% amount of RNA in their cytoplasm after single stresses. Repeated stresses resulted in depletion of RNA. The amount of RNA returned to the initial level within 2 days after single stresses and within 3 days after repeated rotations. The shifts were much less pronounced in motoneurons.

Animals↗

PubMed1979

Local tetanus in rats; concentration of amino acids as studied in spinal cord segments, spinal roots, and dorsal root ganglia.

1. The effect of tetanus toxin injected into one gastrocnemius muscle on the steady state concentration of several amino acids was investigated in spinal cord half segments, spinal roots and dorsal root ganglia of rats. Care was taken to ensure a symmetrical afferent input to the spinal cord and to localize the segment with the highest concentration of tetanus toxin. 2. In the spinal cord segments containing the highest concentration of tetanus toxin the steady state concentration of glycine was higher on the side of the tetanus than on the contralateral control side. Results obtained after intravenous injection of 14C-glycine do not indicate that the higher concentration of glycine on the side of the tetanus was due to a higher uptake of glycine. 3. The results obtained in the spinal cord contradict previous findings of other authors but lend support to the prevailing concept about the action of tetanus toxin in local and general tetanus.

Amino Acids↗

PubMed1976

Homovanillic acid transport by the spinal cord.

Spinal subarachnoid perfusions of rhesus monkeys were performed to study spinal transport of homovanillic acid in control and probenecid-treated animals. Homovanillic acid enters capillaries within spinal tissue throughout the spinal cord. The mean capillary exchange half-time for homovanillic acid was 19.2+/-2.8 minutes; probenecid did not affect this value significantly. Despite its polar nature, homovanillic acid crosses cell boundaries easily and equilibrates in a distribution volume (55 percent) approaching the total water space. The spinal cord clears homovanillic acid from 21+/-4 mul per minute of cerebrospinal fluid. The rate of clearance after probenecid administration was not significantly different. The apparent diffusion coefficient in tissue of homovanillic acid approximated the diffusion coefficient in water (8.0 X 10(-6) cm2 per second). The data show that homovanillic acid is transported by capillaries throughout spinal tissue by a mechanism largely insensitive to inhibition by probenecid. Lumbar cerebrospinal fluid concentrations of homovanillic acid even after probenecid administration therefore reflect only part of the total dopamine metabolism.

Animals↗

PubMed1992

[Extensive bifocal location of ependymoma of the spinal cord].

Spinal cord ependymomas belong to rare tumours of the central nervous system. Their malignancy is usually low although anaplastic forms are known also to occur. Surgical treatment is the method of choice supplemented often with radiotherapy. An exceptionally rare form of ependymoma with two foci of origin in the spinal cord is reported. The large extent of the tumour caused that laminectomy at 15 levels was necessary. The mechanism of ependymoma development at two levels is discussed.

Adult↗

PubMed1979

Arteriovenous malformations of the spinal cord.

Spinal AVM's are not rare, and are diagnosed today with increasing frequency by utilization of moedern neuroradiological techniques. Their relationship to the spinal medulla is related to vascular embryological anatomy, and the only effective treatment is directed at obliteration of the fistula. Males are affected more frequently in the middle years of life. Symptoms may mimic spinal cord tumors and demyelinating disorders. The pathogenesis of symptoms, classification, and methods of diagnosis are reviewed, and the various methods of treatment discussed.

Arteriovenous Malformations↗

PubMedDate not supplied

[Effect of spinal cord and spinal injuries on the phagocytic activity of neutrophils].

Study of neutrophil phagocytic activity in injuries to the spinal cord and spine and in damage to the spine without involvement of the spinal cord showed that injuries to the spinal cord have no specific effect on this activity. True, the phagocytic reaction is inhibited in the first 2-3 weeks after the trauma both in patients with injury to the spinal cord and spine and in those with injury only to the spine. In later periods after the trauma, however, with the neurological status remaining the same, the values of the phagocytic reaction do not differ from those in healthy persons. The level at which the spinal cord is injured hardly affects the activity of phagocytosis. The examination was conducted in 117 patients with spinal fractures 94 of whom had also sustained injury to the spinal cord.

Acute Disease↗

PubMed1977

The mechanism of spinal cord cavitation following spinal cord transection.

Transection of a spinal cord is followed by massive accumulation of lysosomes and release of lysosomal hydrolases within both the rostral and the caudal spinal cord stumps. The lysosomal activity begins at 3 hours after cord transection, maintains its peak for 3 to 7 days, and declines at 14 days after transection. The process if associated with autolysis of the cord stumps and subsequent cavitation. Lysosomal accumulation is greatly diminished, and, paradoxically, superior wound healting is the result at the stumps of a 5-mm segment of isolated spinal cord produced by double cord transection.

Acid Phosphatase↗

PubMed1976

3-Methoxy-4-hydroxyphenylethyleneglycol (mhpg) transport from the spinal cord during spinal subarachnoid perfusion.

Spinal subarachnoid perfusions of rhesus monkeys were performed to study the transport of 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) by the spinal cord. The perfusate contained [3H]MHPG and a reference extracellular space marker ([14C]sucrose of [14C]ethylenediaminetetraacetic acid-calcium complex). The mean (+/- S.D.) clearance of MHPG by the monkey spinal cord was 33 (+/- 4) mul/min. Analysis of serial sections of spinal tissue after each perfusion facilitated determination of several basic parameters of MHPG transport. MHPG has a spinal tissue distribution space of 70-80%. MHPG enters capillaries within spinal tissue throughout the entire spinal cord. The mean capillary exchange half-time was 8.2 min +/- 1.9 min. MHPG crosses cell membranes easily and diffuses through cells rapidly. The apparent tissue diffusion coefficient approximated the diffusion coefficient in water (8.5 x 10(-6) sq.cm/sec). The data suggests that CSF levels of MHPG are an uncertain indicator of norepinephrine metabolism and that lumbar CSF levels of MHPG reflect in large part spinal cord rather than brain metabolism.

Animals↗

PubMed1992

Spinal commissural neurons mediating vestibular input to neck motoneurons in the cat upper cervical spinal cord.

Spinal commissural neurons (CNs) activated di- or trisynaptically by stimulation of ipsilateral vestibular afferents were stained with intraaxonal injection of horseradish peroxidase in the cat upper cervical spinal cord. Stem axons of CNs in lamina VIII or VII, after crossing the midline, had ascending and/or descending main branches that gave off multiple axon collaterals to laminae IX and VIII over a few cervical segments. Terminal boutons appeared to make contact with proximal dendrites and somata of retrogradely-labelled neck motoneurons. Therefore, these CNs were regarded as mediating vestibular afferent input to contralateral neck motoneurons trisynaptically at the shortest.

Animals↗

PubMed1977

The mechanism of spinal cord cavitation follwing spinal cord transection. Part 2. Electron microscopic observations.

The authors report their findings by electron microscopy after microsurgical subpial spinal cord transection in dogs. After cord transection, conspicuous myelin microcysts are formed in a background of otherwise intact cord tisue at a distance of 1 to 2 mm from the cut end of the cord, both proximal and distal to the transection, Seen through the electron microscope, the microcysts iss a myelin sac distended by fluid under pressure, containing a swollen axon filled with excessive axoplasmic organelles; that is, a terminal club. Later the microcysts and terminal clubs rupture. The large spaces within the microcysts are opened to heretofore small extracellular spaces and the spinal cord tissues are destroyed. Thus, microcysts are precursors of large cavitites seen at the ends of transcreted cord stumps. The formation of microcysts and their subsequent rupture, which leads to cord cavitation, is interpreted as an inherent response of cord tissue to injury, and the result of an abortive attempt at cord regeneration.

Animals↗

PubMed1992

Spinal cord tissue pressure during spinal cord distraction in dogs.

Spinal column distraction is a known cause of spinal cord injury. Laplace's law predicts that cord interstitial pressure will elevate during spinal cord distraction. To determine the significance of the Laplace predictions a series of in vitro and in vivo experiments examining spinal cord distraction were performed. In vitro experiments were carried out on 10 dog spinal cords in a specially designed distraction apparatus. These experiments verified the Laplace's law demonstrating a close correlation (R(avg) = 0.99) between the tension applied to the cord, and cord interstitial pressure. Cord interstitial pressure strain (elongation) curves show that initial elongation is accompanied by negligible elevations of cord interstitial pressure; the final 20% elongation being responsible for 80% of the elevation in cord interstitial pressure. In vivo experiments were carried out on five beta-blocked dogs. Significant elevations in cord interstitial pressure were obtained during stepwise spinal column distraction. Spinal cord blood flow and somatosensory evoked potentials were well maintained during distraction until cord interstitial pressure reached 47 mm Hg. At this point a simultaneous fall in spinal cord blood flow and somatosensory evoked potentials was noted. Release of the distracting force resulted in return of spinal cord blood flow, somatosensory evoked potentials, and cord interstitial pressure to baseline. The authors conclude that significant elevations in cord interstitial pressure occur with spinal cord distraction and that these cord interstitial pressure elevations are associated with a reversible ischemic response in the cord.

Animals↗

PubMed1976

Further characterization of the anti-encephalitogenic protein (SCP): isolation from bovine spinal cord and spinal roots.

The three molecular forms of the anti-encephalitogenic protein, beta-SCP, gamma-SCP, and SCP-peptide were isolated in higher yield by a shortened procedure, which involved 1) extraction of bovine spinal cord (BSC) or bovine spinal roots (BSR) with 0.05 M sodium acetate buffer, pH 4.5, 2) batch absorption on CM-52 cellulose, 3) stepwise elution with sodium acetate buffers, pH 5.8, containing increasing concentrations of sodium chloride and finally, 4) removal of trace contaminants by gel-exclusion chromatography on Sephadex G-50 superfine. The m.w. of the purified proteins determined by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis was 13,200 daltons. The same value for the molecular sizes was obtained by gel-exclusion chromatography by using 0.1% SDS in 0.05M sodium chloride as eluant. In the absence of SDS the molecular sizes estimated by gel exclusion chromatography ranged from 14,000 to 18,500. The amino acid compositions of the beta-SCP and gamma-SCP from BSC and BSR were similar except that beta-SCP from BSR lacked half-cystine whereas gamma-SCP from BSR contained three times as much half-cystine as the SCP forms prepared from BSC. All forms of SCP showed reactions of identity when compared by immunodiffusion analyses with a rabbit anti-bovine SCP serum; none formed precipitin lines with a rabbit anti-bovine myelin basic protein (MyBP) serum.

Amino Acids↗

PubMedDate not supplied

[Selective cooling of the spinal cord and spinal nerve roots in patients with spastic and pain syndromes].

Selective cooling of the spinal cord and its roots was applied in 26 patients with a high degree of muscle spasticity of various genesis and in 12 of those with various pain syndromes. Hypothermia was conducted by the open and closed (puncture) methods. The subarachnoid space was cooled to 11--7.5 degrees C. Spasticity diminished to grade I--II in 15 patients and to grade III in 9; in 2 patients it did not change. In 3 of 12 patients the sensation of phantom and pain were completely relieved, marked improvement occurred in 6 patients, while in 3 patients the effect proved short-lived or doubtful.

Evoked Potentials↗

PubMed1992

Ketamine abolishes the tonic phase of the seizures evoked by sudden cooling of toad isolated spinal cords.

Spinal seizures evoked by sudden cooling (SSSC) were used to investigate the anticonvulsant activity of ketamine (KET) injected either intralymphatically (i.l., 5-40 mg/kg) or intrathecally (i.t., 0.5-1.0 mumol/20 microliters) using isolated spinal cord-hindleg preparation. KET inhibited the tonic phase and prolonged the clonic phase in a dose-dependent manner. The cionic phase was depressed or totally blocked at KET doses of 80-160 mg/kg, i.l. or 2 mumol/20 microliters, i.t. This depression was not prevented by i.t. administration of concanavalin A. The latency of onset of seizures was also increased by KET. KET abolishes the tonic-extensor phase of SSSC in which activation of N-methyl-D-aspartate-receptors may play a role.

Animals↗

PubMed1977

Effects of Ro 4-1284 on electrically-induced spinal cord seizures and on spinal cord norepinephrine and 5-hydroxytryptamine levels.

The time course effects of the benzoquinolizine Ro 4-1284 on spinal cord norepinephrine (NE) and 5-hydroxytryptamine (5-HT) levels were compared to the effects of this same drug on electrically-induced spinal cord seizures. The data show that a significant decrease in spinal cord NE levels and a facilitating effect on spinal cord seizures are apparent 15 minutes after Ro 4-1284 (10 mg/kg s.c.) and that both of these effects persist for at least 24 hours. Forty-eight hours after injection, the effects of Ro 4-1284 on seizure and on NE levels are completely dissipated. A significant decrease in 5-HT levels is not apparent until 1 hour after Ro 4-1284. These data suggest that noradrenergic neurons of the spinal cord act as attenuators of seizure activity. The possibility that spinal cord 5-HT also subserves a seizure attenuating function is not precluded.

2H-Benzo(a)quinolizin-2-ol, 2-Ethyl-1,3,4,6,7,11b-↗

PubMed1977

[Changes in the blood vessels of the spinal cord and spinal ganglia following chronic stimulation of the lumbar regions of the sympathetic trunks and gangliosympathectomy].

Morphological studies in 40 rabbits demonstrated that chronic irritation of the lumbar sympathetic trunks resulted in more pronounced architectonic changes, in vessel walls and in neurons of the lumbar sympathetic ganglia in 15 days than did the bilateral lumbar gangliosympathectomy at the same time. In both series of experiments more prominent changes were noticed in the spinal ganglia than in the spinal cord, that could be explained by different degree of lesions in the nerves supplying them and by organic specification of their angioarchitectonics. The data obtained made it possible to include novocain block (anesthesia) into complex therapy to manage spinal apoplexy in clinic.

Animals↗