Electron microscopy of the Macaca mulatta brain after repeated applications of electric current.
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To determine whether electrical stimulation of the periaqueductal gray region decreases anesthetic requirement, the authors studied the effect of such stimulation on the MAC of halothane and 60% nitrous oxide in 33 patients. These patients, who were undergoing implantation of a radio-frequency-coupled receiver and connection of that receiver to electrodes previously implanted in the periaqueductal gray area, were assigned randomly to receive (n = 16) or not receive (n = 17) electrical stimulation 1 h before surgery. The mean value (+/- SEM) for the minimum alveolar concentration of halothane combined with 60% nitrous oxide was significantly less (P less than 0.001) for patients who were stimulated preoperatively (0.15 +/- 0.05%) than for those who were not (0.51 +/- 0.02%). The authors conclude that stimulation of the periaqueductal gray region decreases anesthetic requirements and believe that at least three mechanisms are possible: a nonspecific narcotic-like effect, a specific effect on a pain pathway, or an effect on specific neural pathways that affect anesthetic requirements secondary to changes in regional concentrations of neurotransmitters.
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Ten subjects who had suffered from sleep onset insomnia for a minimun of 2 years participated in a double blind study of the effects of electrosleep on this disorder. This paper reports a 2-year follow-up of these subjects. Of the five subjects who received 24 live treatments, four appeared to be able to fall asleep with little difficulty and to awake feeling moderately to very well rested. Only one appeared to have relapsed during the 2-year-no-treatment period. Of those receiving sham treatment four were having quite a bit of difficulty falling asleep but three of the five awoke feeling moderately well rested. Although the number of subjects is small, the trends appear consistent with the interpretation that sleep habits were improved for most of the real treatment subjects and for few of those receiving sham treatment.
The effects of cerebral electric therapy (electrosleep) and placebo on self-ratings of anxiety, depression, and hostility were compared. No difference in the amount of improvement shown by the two groups appeared on any of the five measures employed, although a major placebo effect was evident on all of the criteria. The results argue against the use of electrosleep as a treatment for these symptoms except when it may be employed for its placebo value.
To clarify the diverse published results of cranial electrostimulation (CES) efficacy, we conducted an extensive literature review that identified 18 of the most carefully conducted randomized controlled trials of CES versus sham treatment. For the 14 trials that had sufficient data, we used the techniques of meta-analysis to pool the published results of treating each of four conditions: anxiety (eight trials), brain dysfunction (two trials), headache (two trials), and insomnia (two trials). Because studies utilized different outcome measures, we used an effect size method to normalize measures which we then pooled across studies within each condition. The meta-analysis of anxiety showed CES to be significantly more effective than sham treatment (p < .05). Pooling did not affect results that were individually positive (headache and pain under anesthesia) or negative (brain dysfunction and insomnia). Most studies failed to report all data necessary for meta-analysis. Moreover, in all but two trials, the therapist was not blinded and knew which patients were receiving CES or sham treatment. We strongly recommend that future trials of CES report complete data and incorporate therapist blinding to avoid possible bias.
We report a survey investigation on the perceived value of behavioral assessment and the use of nonpharmacologic treatment of insomnia by 159 physicians in private practice in Davidson County, Tennessee. They generally attributed limited value to behavioral assessment, and reported infrequent use of nonpharmacologic treatment. However, the more patients the physicians saw with insomnia as the chief symptom, the more they tended to value behavioral assessment and other diagnostic procedures. Endorsement of behavioral assessment and all other diagnostic practices was in turn related to the use of behavioral treatment techniques. We suggest that a lack of awareness of the value of alternative assessment and treatment strategies may account for physicians' limited use of nonpharmacologic approaches to this common yet frequently serious medical problem.
Chronic monopolar electrodes were implanted in the region of the midbrain central gray in eight rats. In three rats, continuous 60 cycle-per-second sine-wave stimulation resulted in an electrical analgesia defined by the elimination of responses to aversive stimulation while general motor responsiveness was retained. Exploratory laparotomy was carried out in these animals during continuous brain stimulation without the use of chemical anesthetics. Following surgery, brain stimulation was terminated, and responses to aversive stimuli returned. Electrodes effective in inducing electrical analgesia at the lowest currents were located at the dorsolateral perimeter of the midbrain central gray. It was concluded that focal brain stimulation in this region can induce analgesia in the absence of diffusely applied "whole brain" stimulation.
Beta-Endorphin-like immunoreactivity in cerebrospinal fluid was assayed in 11 patients receiving electrical stimulation of the brain for chronic pain. Immunoreactivity increased dramatically after contrast ventriculography prior to stimulation. No further elevations were observed after stimulation. The magnitude and time course of elevations were identical after placement of electrodes either in the thalamus or in the periventricular gray matter. These results suggest that previous findings of stimulation-induced elevation of beta-endorphin-like immunoreactivity in cerebrospinal fluid are attributable to an artifact of contrast ventriculography.
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Turkey hens were stunned by inducing anoxia with either argon (with approximately 2 per cent residual oxygen) or 30 per cent carbon dioxide in argon with 2 per cent residual oxygen, and the carcases were bled either immediately or five or 10 minutes after they had been stunned. A control group of turkeys was stunned electrically (250 mA for about four seconds) and had their necks cut immediately after stunning. The amount of blood lost was measured and expressed as a percentage of liveweight. The results showed that the necks of gas-stunned turkeys can be cut up to 10 minutes after they have been stunned without reducing the total blood loss significantly.
Pigs from four farms (two producing 'easy' and two 'difficult to handle' pigs) were slaughtered at two abattoirs, each with two slaughter handling systems, so that 25 pigs of each behavioural type were slaughtered by all four handling systems on each day; there were 16 replicates (3200 pigs) in total. The pigs at abattoir X were electrically stunned, either in a floor pen holding five pigs or in a race-restrainer. At abattoir Y the pigs were stunned either in a floor pen holding five pigs or in a dip-lift carbon dioxide stunner. The following measurements were made: hot carcase weight and backfat thickness at P2, degree of rigor mortis 35 minutes post mortem, skin blemish, pH and muscle reflectance in the m longissimus dorsi at 60 minutes and 18 hours post mortem, and pH and muscle reflectance in the m adductor at 18 hours post mortem. At abattoir X, the pigs slaughtered in the race-restrainer had heavier carcases (74.0 kg vs 73.0 kg, P < 0.05), developed rigor mortis more rapidly (8.1 mm vs 7.3 mm, P < 0.01), had more skin blemish (2.8 vs 2.7, P < 0.01), paler m longissimus dorsi muscles after one hour (15.7 vs 13.9, P < 0.01) and 18 hours (27.8 vs 26.6, P < 0.05), and paler m adductor muscles (24.5 vs 22.7, P < 0.001) after 18 hours. At abattoir Y, the pigs handled through the floor pen system had more skin blemish (2.7 vs 2.6, P < 0.05) and a tendency to develop rigor mortis more quickly (6.11 vs 5.32, P = 0.089).(ABSTRACT TRUNCATED AT 250 WORDS)
The effects of the current and its waveform on the prevalence of broken bones and breast meat haemorrhages in electrically stunned broiler chickens were examined at two poultry processing plants. Increasing the current over the range from 68 to 115 mA per bird had very little effect on the carcase quality, but increased the incidence of broken furculum and coracoid bones in birds stunned with a sinusoidal alternating current (AC). Clipping a sinusoidal AC with a thyristor had a pronounced effect on the carcase quality, and resulted in more broken bones and breast meat haemorrhages.
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The effect of electro-acupuncture in the treatment of naloxone precipitated morphine withdrawal in mice was studied. Thirty minutes of acupuncture was enough to suppress withdrawal behaviors by more than 60%. Concomitant to the decrease of withdrawal behavior, there was a significant increase of brain beta-endorphin level in the acupunctured animals. Plasma beta-endorphin level of the treated and untreated group was not significantly different.
Six ear acupuncture points, one non-acupuncture ear point, and the body locus Ho-Ku (LI-4) were electrically stimulated in order to compare the effects of stimulation on the body's pain threshold at selected loci on various points on the body by measurement with a radiation heat-type Pain Meter on 5 subjects. The ear points, with the exception of the non-acupuncture ear point, were found to be effective even in peripheral body regions in varying degrees. Ear stimulation did not increase the threshold as rapidly as Ho-Ku. In all cases where the pain threshold was raised, the effect persisted after electrical stimulation had stopped.
Role of the subsequently excited receptors elicited by tetanic muscular contraction in electro-acupuncture analgesia was examined. Conditioning stimulation of the nerve (CPN) as well as electro-acupuncture induced a significant delay of the tail flick latencies of the rat with weak intensity of stimulus (1.0-1.5 x DFT), and this effect was abolished after section of the nerve at a point distal to the stimulating electrode. Electrophysiological data indicate that a small amplitude of the A large fiber group's potential was recorded with the intensity range of 1.0-1.5 x DFT. These facts suggest that the analgesic effect induced by weak stimulation is not the result of direct excitation of afferent fibers but the result of subsequent activation of receptors provoked by tetanic muscular contraction. The possible receptors are proposed and their participation in acupuncture analgesia also discussed. CPn = the common peroneal nerve; DFT = dorsal flexion threshold (1.0 x DFT = 1.15 x Ta).