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71.
Kazumasa Shindo MD Shin-ichi Tsunoda MD Zenji Shiozawa MD 《Clinical autonomic research》1994,4(6):299-302
Microneurography was performed in a 39-year-old woman with demyelination of the pontine white matter associated with muscle spasms in the lower extremities. Single bursts on the microneurogram were observed immediately after cessation of the spasm with no systemic changes in the blood pressure or heart rate. Voluntary tonic flexion of the lower extremities induced similar bursts with small amplitudes. These reflex bursts possessed a characteristic of muscle sympathetic nerve activity, because the latency between the peak of each burst and the prior R-wave on the electrocardiograph was constant. The occurrence of these bursts suggests that a segmental compensatory mechanism in the spinal cord may stabilize the muscle blood flow influenced by muscle contraction. 相似文献
72.
Rupture of an intra-aortic balloon counterpulsator (IABCP) demands immediate removal. We report a case of thrombus formation within a Datascope IABCP secondary to IABCP rupture, necessitating surgical exploration for removal. There is a disturbing pattern of balloon ruptures with this type of IABCP. 相似文献
73.
There are relatively few papers which prove that one nerve anastomotic agent for the facial nerve is superior to any other. Previous experiments on the division and anastomosis of the facial nerve have failed to consider the indeterminate variables involved, i.e. operator variability, controls and the reaction of the materials on normal nerve tissue. In this experiment, a variety of anastomotic agents were tested to see if the anastomotic agents themselves affected the extra-temporal facial nerve function. The absorbable suture, non-absorbable suture, glue and tube wrap used had no effect on normal nerve tissue or on the anastomosis of the sectioned facial nerve of the rat compared with simple laying together of the divided ends of the divided nerve. 相似文献
74.
Vagus Nerve Stimulation Induces a Sustained Anticonvulsant Effect 总被引:17,自引:11,他引:6
Summary: Purpose: Stimulation of the vagus nerve can effectively abort several types of experimentally induced seizures in animals when administered near the time of seizure onset. Indirect evidence from human trials and animal studies suggests that the anticonvulsant effects of vagus nerve stimulation (VNS) extend beyond the duration of stimulation. We used the pentylenetetrazol model to determine whether VNS exerts a persistent anticonvulsant effect.
Methods: VNS (1 mA, 30 Hz, 500 μs pulse width) was administered continuously for 0, 1, or 60 min, or intermittently (30 s on, 5 min off) for 60 min, to awake and freely moving animals. After the end of stimulation, pentylenetetrazol (50 mg/kg i.p.) was administered to induce seizures. Time-course studies were also performed, consisting of 60 min of VNS followed by pentylenetetrazol injection after 0, 3-, 5-, and 10-min intervals.
Results: The greatest anticonvulsant effect occurred after 60 min of continuous VNS, which prevented convulsions in four of 12 rats and reduced significantly seizure duration, the total number of seizures, and number of tonic seizures. Intermittent VNS was less effective than continuous stimulation for 60 min, but more effective than that for 1 min. The anticonvulsant effect declined in a time-dependent fashion after discontinuation of VNS, with return to nonstimulated control values by 10 min.
Conclusions: The results of this study verify a persistent VNS-induced anticonvulsant effect and indicate that its efficacy is dependent on the cumulative stimulus duration. 相似文献
Methods: VNS (1 mA, 30 Hz, 500 μs pulse width) was administered continuously for 0, 1, or 60 min, or intermittently (30 s on, 5 min off) for 60 min, to awake and freely moving animals. After the end of stimulation, pentylenetetrazol (50 mg/kg i.p.) was administered to induce seizures. Time-course studies were also performed, consisting of 60 min of VNS followed by pentylenetetrazol injection after 0, 3-, 5-, and 10-min intervals.
Results: The greatest anticonvulsant effect occurred after 60 min of continuous VNS, which prevented convulsions in four of 12 rats and reduced significantly seizure duration, the total number of seizures, and number of tonic seizures. Intermittent VNS was less effective than continuous stimulation for 60 min, but more effective than that for 1 min. The anticonvulsant effect declined in a time-dependent fashion after discontinuation of VNS, with return to nonstimulated control values by 10 min.
Conclusions: The results of this study verify a persistent VNS-induced anticonvulsant effect and indicate that its efficacy is dependent on the cumulative stimulus duration. 相似文献
75.
Jin Jiabu Wang Yunxiang Qin Chaoji Department of Physiology Fourth Military Medical College Xi''''an 《中国人民解放军军医大学学报》1987,(3)
The effects of vagal and sympathetic nerves on the transmembranepotentials of cardiac cells of toad were observed by means of microelectrodetechnique.The vagal nerve was stimulated there would be an increase in restingpotential and acceleration in repolarization of action potential(AP).However,ifatropine was used before stimulation the above-mentioned phenomena woulddisappear.When the sympathetic nerve was stimulated the AP amplitudeincreased,but resting potential(RP)remained the same.The increase of APresulted from the increases of overshoot.When the sympathetic nerve wasstimulated although the heart rate increased and the duration of AP wasshortened,the plateau phase of AP was prolonged.These results suggest that theeffects of vagal and sympathetic nerves on the transmembrane potential of cardiacventricular cells are coordinated and the normal characteritics of transmembranepotential are maintained by both the vagal and sympathetic nerves. 相似文献
76.
Skin infection in a man immunosuppressed by corticosteroid treatment was found to be due to Pseudallescheria boydii. Although treatment is often unsatisfactory, infection in this patient responded well to oral ketoconazole and topical miconazole. 相似文献
77.
78.
Joseph R. Holtman Jr. Nancy C. Anastasi Wesley P. Norman Kenneth L. Dretchen 《Brain research》1986,362(2)
The effect of electrical and chemical (l-glutamate) stimulation of the raphe obscurus on phrenic nerve activity was examined in the cat. Phrenic nerve activity was recorded from a C5 nerve root in anesthetized, paralyzed and artificially ventilated cats. Neural discharge was quantitated by integrating the phrenic nerve activity. The respiratory frequency was determined from the integrated nerve signal. Focal electrical stimulation (18–144 μA; 5–40 Hz; 100 μs pulse duration) resulted in significant (P < 0.05) increases in both integrated phrenic nerve (IPN) amplitude and respiratory frequency. These changes were dependent upon current intensity and frequency of stimulation. The largest increases in IPN amplitude and respiratory frequency were47 ± 17%and146 ± 8%, respectively. To insure that the changes in integrated phrenic nerve activity (IPNA) were the result of stimulation of cell bodies and not axons of passage,l-glutamate (100, 200 nmol) was microinjected (100 nl) into the raphe obscurus. Significant (P < 0.05) dose-related changes occurred in integrated phrenic nerve amplitude with an increase of44 ± 13% at 100 nmol and80 ± 13% at 200 nmoll-glutamate. No significant increase in respiratory frequency was observed withl-glutamate microinjection. The results suggest that the raphe obscurus may be involved in respiratory control. 相似文献
79.
During the early stages of nerve implantation, we followed the dynamic properties of the lateral gastrocnemius muscle of the rat, reinnervated with an acutely or chronically severed peroneal nerve. The aim of this study was to ascertain whether (1) the better functional recovery of a muscle reinnervated by a chronically severed foreign nerve is present from the onset of reinnervation, and (2) whether such functional improvement is due to the conditioning lesion effect. Our results indicate that better functional recovery is already apparent one week after nerve implantation, and it is due to the conditioning lesion effect, since tenotomy prevents such improvement. The tenotomy effect underlines the fact that some environmental factors concerning the target tissue, and not only the predegenerated nerve, are involved in the conditioning effect. © 1995 Wiley-Liss, Inc. 相似文献
80.