Effect of electrical stimulation of red nucleus on acupuncture analgesia

The function of red nucleus (RN) was important in motor control. This work was to study whether the RN influenced the effect of EA and the somatosensory afferent system. C-responses of spinal dorsal horn neurons (SDHN) were recorded as nociceptive responses. Electrical stimulation of RN could intensify the inhibitory effect of EA and inhibit nociptive response of SDHN. Naloxone (NX) could completely block that inhibition of RN. The result inferred that the RN can modulate both of somatomotion and somatosense. The endogenous opiate system is involved in the somatosensory modulation of RN.     

Effect of extradural analgesia on the paradoxical arousal response of the electroencephalogram

Nineteen patients with Duchenne's muscular dystrophy underwent segmental spinal instrumentation and posterior fusion between 1989 and 1994. The indication for surgery was loss of the ability to walk and development of scoliosis with sitting discomfort. Preoperative assessment included evaluation of pulmonary function. Average age at operation was 12.5 years. Instrumentation and fusion extended from upper thoracic levels to L-5 or the sacrum. A Hartshill rectangle was used in all cases, with banked allograft bone. Severe intraoperative blood loss was avoided by use of hypotensive anaesthesia. Peroperatively, systolic blood pressure was maintained between 75 and 85 mm Hg. Average blood loss was 1,246 ml (range, 400-3,100) or 30% of estimated total blood volume. Average transfusion requirements were 3 units of packed cells. Postoperative analgesia was provided by infusion via an epidural catheter. There were no postoperative wound or chest infections. Three patients required catheterisation for urinary retention. Postoperatively patients were fitted with a Neofract jacket to allow early mobilisation and discharge. Mean postoperative length of stay was 16 days. Posterior spinal fusion by using the Hartshill rectangle provided good correction and fixation. Hypotensive anaesthesia permitted surgery to be performed rapidly in a relatively dry field and avoided the complications of severe intraoperative blood loss and massive transfusion.     

Diazepam modulation of stress-induced analgesia depends on the type of analgesia.

Factors that determine the impact of diazepam on the hypoalgesia produced by electric shocks were investigated. Tailshocks (1, 5, & 20) were followed by an initial hypoalgesia, lasting 2–4 min, that was unaffected by prior administration of diazepam. This hypoalgesic reaction was followed by a second hypoalgesia if subjects were allowed to remain in the shock environment during testing, and this reaction was reduced or eliminated by prior diazepam. If subjects were removed from the shock situation, this second reaction did not occur. In contrast, 80 shocks were followed by a single hypoalgesia that was sensitive to blockade by diazepam throughout its entire course and was not affected by removing subjects from the shock environment. These results have implications for the perceptual–defensive–recuperative, working memory, and unconditioned response (UCR)-learned helplessness interpretations of shock-produced analgesia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of hypnotic analgesia on verbal report and cardiovascular responses to ischemic pain.

A slowly mounting form of ischemic pain produced substantial increases in systolic blood pressure (SBP), heart rate (HR), and pain state (PS) in 8 highly susceptible hypnotic Ss on an unhypnotized control day, when ischemia was extended to a median duration of 19 min. On a 2nd day, after hypnotically suggested analgesia, a repetition of the ischemic stimulus produced significantly lower SBP, HR, and PS at a median 19 min., and in 6 Ss, PS reports of 0 and neglibible changes in SBP and HR, even though ischemia was extended to a median duration of 30.2 min. It is concluded that: (a) hypnotic analgesia is effective, in selected Ss, in reducing reported pain of ischemia; (b) reductions in SBP and HR accompany the reduction in reported pain, thus validating the subjective reports; and (c) evidence answers possible criticisms of a design calling for repeated measures on the same Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of epidural vs parenteral opioid analgesia on the progress of labor: a meta-analysis

CONTEXT: Epidural labor analgesia, if selected by the patient, is associated with high cesarean delivery rates. Results of randomized trials comparing rates of cesarean delivery using epidural anesthesia vs parenteral opioids are inconsistent. OBJECTIVE: To review the effects of epidural vs parenteral opioid analgesia on cesarean delivery rates. DATA SOURCES: Studies were identified by searching MEDLINE from January 1966 through January 1998, the Cochrane Database of Perinatal Trials, and relevant nonindexed journals and abstracts. STUDY SELECTION: We included all studies that randomized patients to epidural vs parenteral opioid labor analgesia. DATA EXTRACTION: Two authors independently extracted data from 10 trials enrolling 2369 patients. Odds ratios (ORs) for categorical data, weighted mean differences (WMDs) for continuous data, and 95% confidence intervals (CIs) were calculated using a random-effects model. DATA SYNTHESIS: The risk of cesarean delivery did not differ between patients receiving epidural (8.2%) vs parenteral opioid (5.6%) analgesia (OR, 1.5; 95% CI, 0.81-2.76). Epidural patients had longer first (WMD, 42 minutes; 95% CI, 17-68 minutes) and second (WMD, 14 minutes; 95% CI, 5-23 minutes) labor stages. While epidural patients were more likely to have instrumented delivery (OR, 2.19; 95% CI, 1.32-7.78), they were no more likely to have instrumented delivery for dystocia (OR, 0.68; 95% CI, 0.31-1.49). After epidural analgesia, neonates were less likely to have low 5-minute Apgar scores (OR, 0.38; 95% CI, 0.18-0.81) or to need naloxone (OR, 0.24; 95% CI, 0.07-0.77). Women receiving epidural analgesia had lower pain scores during the first (WMD, -40 mm on a 100-mm scale; 95% CI, -42 to -38 mm) and second (WMD, -29 mm; 95% CI, -38 to -21 mm) stages of labor. The odds of dissatisfaction were lower with epidural analgesia (OR, 0.25; 95% CI, 0.20-0.32). CONCLUSIONS: Epidural labor analgesia is not associated with increased rates of instrumented vaginal delivery for dystocia or cesarean delivery. Patients receiving epidural analgesia have longer labors. Patient satisfaction and neonatal outcome are better after epidural than parenteral opioid analgesia.     

Effect of perinatal malnutrition on the inactive behavior induced by long-term shock and conditioned analgesia

Inactive behavior in response to long-term inescapable foot shock (IS) and conditioned analgesia were evaluated in adult rats perinatally undernourished. During the IS session, control rats exhibited first a period of vigorous activity and then inactive behavior, during which they accepted the shock more passively. Moreover, when these same animals were subsequently placed in the environment associated with shock application, they showed an increase in the paw lick latency. Conversely, in malnourished rats, this IS schedule induced lower behavioral inactivity and rats failed to develop conditioned analgesia. When undernourished rats were injected with morphine (MOR) before IS exposure, it was observed that both phenomena--inactivity during shock and analgesia conditioned by submission to the shock context--were normalized. A possible alteration in the activation of an opiate process implicated in the stress response in early undernourished rats is suggested.     

Effect of partial reinforcement on tolerance to morphine-induced analgesia and weight loss in the rat.

Groups of 60 male Sprague-Dawley rats were presented a distinctive set of environmental cues on several occasions. For 1 group, morphine (40 mg/kg) was injected each time the cues were presented (morphine/continuous reinforcement). For a 2nd group, morphine was injected only following 1 of 4 cue presentations (morphine/partial reinforcement). Two additional groups were injected with only saline, one on the continuous reinforcement schedule and the other on the partial reinforcement schedule. Results demonstrate less tolerance to morphine in the partially reinforced morphine-injected Ss than in continuously reinforced morphine-injected Ss. Unlike other demonstrations of a tolerance-retarding effect of partial reinforcement, findings did not result from nonassociative factors related to differential novelty, stress, or practice. Clinical implications for the tolerance-retarding effect of partial reinforcement are discussed. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

机上冷却烧结机对机尾除尘系统的影响

通过对包钢炼铁厂二烧车间工艺改造后的生产实践和测试数据作分析讨论,说明机上冷却工艺有利于除尘系统的正常工作,有利于简化除尘设备改善环境;是烧结行业保护环境的发展方向.     

Effect of an antiandrogen on the lymphoid system

A side-effect of the administration of cyproterone acetate, an antiandrogenic steroid, to newborn, juvenile or adult male mice (in doses comparable to those used clinically) was found in a marked reduction of the white pulp of the spleen and reduced weight or even absence of the thymus.     

The effects of belief on acupuncture analgesia.

24 undergraduates who had indicated either a high or low level of belief in acupuncture-induced analgesia received either acupuncture or a pseudo-acupuncture treatment prior to a 60-sec cold-pressor test. Ss also completed the State scale of the State-Trait Anxiety Inventory at the beginning of the experiment and provided ratings of pain intensity during the cold-pressor test. Ss who held positive beliefs about the effectiveness of acupuncture and who received actual acupuncture treatment reported lower pain than did Ss with negative beliefs and those who received pseudo-acupuncture. Anxiety ratings did not differ between groups. The ratings of belief in acupuncture shown by the 2 groups tended to converge after treatment. Results suggest that differences in the analgesic effects of acupuncture are influenced by expectancy effects and the degree to which expectations are confirmed during the treatment procedure. (French abstract) (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Environmentally induced analgesia: Age-related decline in a neurally mediated, nonopioid system.

Two experiments examined the function of an endogenous system of pain inhibition during aging. In Exp I, 80 male Sprague-Dawley rats (aged 3, 14, and 24 mo) were exposed to 90 sec of hindpaw shock. To investigate the pharmacology and anatomy involved in the production of hindpaw shock-induced analgesia, the effects of naltrexone (7 mg/kg), scopolamine (5 mg/kg), and adrenalectomy were examined. Results show that there was an age-related reduction in the degree of analgesia produced by hindpaw shock. Naltrexone and adrenalectomy did not alter the analgesia elicited by hindpaw shock. Scopolamine reduced the analgesia produced by hindpaw shock, and the effectiveness of scopolamine blockage declined with age. Exp II, with 18 3-mo-old and 13 23-mo-old male Sprague-Dawley rats, demonstrated that the effect of scopolamine was specific to the analgesia induced by hindpaw shock because scopolamine was ineffective in modifying the analgesia produced by a different stressor (cold water). It is suggested that the decline in hindpaw shock-induced analgesia is the result of an alteration in the function of the cholinergic system. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of patient-assisted epidural analgesia with continuous-infusion epidural analgesia for postoperative patients

Number of electroconvulsive therapy (ECT) treatments administered and severity of psychopathology confound the interpretation of clinical studies that address the relationship between the rate of administration of ECT and cognitive morbidity occasioned by the treatment. A preclinical study was therefore conducted to address the issue. Three groups (n = 8/group) of adult male Sprague-Dawley rats received six electroconvulsive shocks (ECS) in daily ECS, 3 ECS/week, and 2 ECS/week schedules; a fourth group (control; n = 8) received only sham ECS. From days 2 to 7 after the conclusion of the ECS/sham ECS course, the rats were monitored for learning on the Hebb-Williams complex maze. The control, 2 ECS/week, and 3 ECS/week groups showed significant learning by days 3, 5, and 7, respectively, while the daily ECS group showed no significant learning during the assessment period. This indicates that even when the cumulative effect of ECS on learning is controlled for, more frequent ECS is associated with slower learning. Extrapolating to clinical settings, it is suggested that wider spacing of ECT may lessen ECT-induced cognitive morbidity.     

Influence of naloxone on shock-induced freezing and analgesia.

Six experiments, with 196 male Holtzman rats, examined whether mild shock activates an opiate analgesia. Exps I–III explored whether naloxone potentiates shock-induced freezing by blocking an opiate analgesia. In Exp I, Ss treated with naloxone (3 or 50 mg/kg, sc) froze more following mild shock. Exp II revealed that both dose levels of the drug increase pain reactivity. Results of Exp III suggest that a naloxone-induced increase in pain reactivity accounts for the drug's effect on freezing. Exps IV–VI investigated the nature of the analgesia induced by mild shock. In Exp IV, mild shock induced a profound analgesia as measured by the tail-flick test. In Exp V, mild shock elicited a transient naloxone-insensitive analgesia that rapidly dissipated to reveal an analgesia that was reversed by a high dose of naloxone. This suggests that mild shock activates both the nonopiate and the opiate form of analgesia. Exp V also showed that a low dose of naloxone potentiated shock-induced analgesia. Exp VI revealed that this potentiated analgesia was attenuated by a high dose of naloxone. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of age and long-term stress experience on adaptation to stress analgesia in mature rats: Role of opioids.

Evaluated the effects of aging and previous long-term stress on development of tolerance to stress-induced analgesia, using 60 male Sprague-Dawley rats in 5 experiments. Ss were exposed to intermittent cold water swims (ICWS) in 2°C water (18 10-sec exposures, 3/min) on 15 consecutive days. Analgesia was measured by the tail-flick test prior to and 30 min after ICWS. In young Ss (4 mo), tolerance developed faster and asymptotic tolerance was acquired sooner and was more complete than in older Ss (15-16 mo). Previous long-term exposure (but not the age at which it occurred) accelerated the development and acquisition of asymptotic tolerance to reexposure. Naltrexone (10 mg/kg, intraperitoneally) partially and completely reversed tolerance to ICWS analgesia in 4-, 9-, and 10-mo-old Ss, respectively, suggesting that the opioids are involved in ICWS-analgesia tolerance in both young and old mature Ss. In young Ss, a 2nd mechanism, naltrexone-insensitive, may be responsible for at least some of the differences in ICWS tolerance found between young and old mature adult Ss. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)