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Query: UMLS:C0030193 (pain)
 261,466 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We previously reported that morphine fails to produce analgesic tolerance when administered in the presence of formalin-induced pain, which may be related to activity of the hypothalamic-pituitary-adrenal axis. In the present study, we examined whether suppression of corticosterone secretion during pain prevents the blockade of tolerance to morphine analgesia. Male Long-Evans rats were injected with morphine (20 mg/kg) or saline for 4 consecutive days in the presence or absence of formalin-induced pain. To suppress corticosterone activity, some animals were injected daily with the corticosterone synthesis inhibitor, metyrapone (100 mg/kg), 24 h and 30 min before formalin injections. The analgesic effect of a test dose of morphine (10 mg/kg) was then measured in the tail-flick test 24 h after tolerance induction (i.e. day 5). The presence of pain during tolerance induction prevented the development of analgesic tolerance. Furthermore, inhibition of corticosterone synthesis by metyrapone prevented the blockade of tolerance by pain. These results suggest that the blockade of tolerance to morphine analgesia by formalin-induced pain depends on stress-induced corticosterone increases.
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PMID:The role of corticosterone in the blockade of tolerance to morphine analgesia by formalin-induced pain in the rat. 931 Feb 99

The Evans tenodesis is an operative treatment for chronic ankle instability with good short-term results. The disadvantage of impaired hind foot kinematics and restricted motion has been described, and only few reports of long-term results can be found. No techniques have been used to assess the outcome objectively. We wanted to determine whether a modified Evans procedure led to a satisfactory clinical and functional outcome. Nineteen patients were available at a 10-year follow-up. The clinical examination included a detailed questionnaire and stress radiographs. Foot function was evaluated with plantar pressure distribution measurements during walking and peroneal reaction time measurements elicited on a rapidly tilting platform (recorded with surface electromyography). High subjective patient satisfaction was contrasted with a high rate of residual instability, pain, and swelling. The radiographs showed an increased number of exostoses. The gait analysis revealed reduced peak pressures under the lateral heel and increased values under the longitudinal arch. The reaction times of the peroneal muscles were shorter on the operated side (significant: peroneus longus). The persistent clinical problems as well as the functional changes indicate that the disturbed ankle joint kinematics permanently alter foot function and may subsequently support the development of arthrosis. Therefore, the Evans procedure should only be applied if anatomical reconstruction of the lateral ankle ligaments is not feasible.
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PMID:Functional evaluation of the 10-year outcome after modified Evans repair for chronic ankle instability. 942 77

Second part of this paper deals with developing of the etiopathological concepts on algodystrophy. Variety of terms have been used to describe the syndrome during over hundred years. The name "reflex sympathetic dystrophy" introduced by J.A. Evans in 1946 is commonly used in English and American literature. French rheumatologists proposed the term "algodystrophy" in 1960; this seemed very satisfactory, because did not imply involvement of any particular tissue, localization or etiology but reflected the combination of pain and dystrophic changes. Current taxonomic concepts were also presented e.g. "complex regional pain syndrome". A discrepancies on the incidence rates of the condition were mentioned and their causes suggested. Current diagnostic criteria of the syndrome were presented. The contribution of Polish authors was reminded. In spite of considerable progress in understanding of the syndrome, its many aspects remain controversial or obscure.
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PMID:[A historical review of algodystrophy: part II]. 947 12

Two distinct populations of aged, Long-Evans rats can be identified on the basis of performance in the Morris water maze task. Aged (24 month) unimpaired rats perform similarly to young (six month) animals. Aged, impaired rats display latencies to find the submerged platform greater than two standard deviations from the mean of the young animals. A hallmark of efficient cognitive processing is the ability to cope with environmental change. Consequently, the present studies were conducted to assess if aged, impaired animals display differential reactivity to repeated exposure to novel stimuli. Reactivity was assessed by examining the degree of (i) consumption of a novel gustatory/olfactory stimulus (sweetened milk), (ii) pain inhibition induced by exposure to a novel hot-plate (48.5 degrees C) apparatus and (iii) exploratory behaviour in an elevated plus maze and a novel open field. Aged, impaired rats exhibited lower milk consumption on day one and protracted reactivity (lower consumption over days two to eight) in comparison to aged, unimpaired and young animals. Aged, impaired rats were more reactive to novelty on the hot plate test (as indicated by longer paw lick latencies); this novelty-induced pain inhibition did not habituate in aged, impaired rats following repeated plate exposures. The degree of exploratory behaviour in both the plus maze and the open field was reduced in aged, impaired rats. This effect was not entirely a consequence of deficient affective mechanisms, as measures of anxiety (e.g., time in open arms, time in inner squares) were not different among aged impaired, aged unimpaired and young animals. These results are the first to demonstrate that behavioural deficits observed in aged, impaired animals extend beyond the impairments observed in the water maze. This behavioural profile is attributed, in part, to heightened anxiety. In addition, the impairments observed in aged, impaired animals may also reflect a reduced sensitivity to the positive incentive properties of novel stimuli.
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PMID:Reactivity to novelty in cognitively-impaired and cognitively-unimpaired aged rats and young rats. 948 51

The effect of topical colchicine treatment of the sciatic nerve on sciatic and saphenous nociceptive thresholds and neurogenic extra-vasation was investigated in normal and neuropathic rats. After a pilot investigation using several different concentrations of colchicine it was determined that treating the sciatic nerve with 5 mM colchicine did not usually affect the heat nociceptive threshold over the sciatic innervated plantar surface of the hindpaw. Mechanical nociception and motor function were also unchanged. Electrical stimulation of the sciatic nerve after intravenous injection of Evans blue dye causes extravasation of the dye in the cutaneous distribution of the nerve. The area and quantity of sciatic extravasation were measured 3 weeks after treating the sciatic nerve with colchicine. This treatment results in a marked loss of neurogenic extravasation, but there were no changes in the sciatic and saphenous mediated heat and mechanical nociceptive thresholds. The area of saphenous nociceptive innervation was mapped using pinch responses and saphenous neurogenic extravasation acutely after sciatic section. There was no change in the cutaneous distribution of saphenous nociceptive fibers when measured 3 weeks after the sciatic colchicine treatment. Some rats had their sciatic nerves transected immediately after colchicine treatment (5 and 50 mM) and the saphenous nociceptive thresholds and autotomy scores were followed postoperatively. Colchicine pretreatment of the sciatic nerve has no effect on the development of hyperalgesia or autotomy. Colchicine blocks axonal transport in peripheral nerve, including the orthograde transport of tachykinins, which probably explains its ability to induce prolonged reductions in sciatic neurogenic extravasation at concentrations that spare C-fiber nociceptor function. Sciatic nerve colchicine treatment does not trigger nociceptive fiber collateral sprouting from the adjacent saphenous nerve, nor does it influence the development of hyperalgesia and autotomy behavior after sciatic transection.
Pain 1998 Jan
PMID:Colchicine treatment of the sciatic nerve reduces neurogenic extravasation, but does not affect nociceptive thresholds or collateral sprouting in neuropathic or normal rats. 951 55

Previous studies have shown that intraspinal injection of quisqualic acid (QUIS) produces excitotoxic injury with pathological characteristics similar to those associated with ischemic and traumatic spinal cord injury (SCI). Significant changes in the functional properties of sensory neurons adjacent to the site of injury have also been observed in this model. Additionally, following QUIS injections, mechanical and cold allodynia, combined with excessive grooming behavior have been shown to be the behavioral correlates of these pathological and physiological changes. These behaviors are believed to be related to the clinical conditions of spontaneous and evoked pain following SCI. Given the therapeutic properties of adrenal chromaffin cell transplantation in conditions of neuropathic and cancer pain, it is proposed that the neuroactive substances released from chromaffin cells can alter or prevent the onset and progression of QUIS-induced behavioral changes. The effects of adrenal transplants were evaluated in 14 male Long-Evans rats that received intraspinal injections of QUIS. Pain behaviors, including the progression of excessive grooming behavior (n=8) and hypersensitivity to mechanical and thermal stimuli (n=6) were evaluated following transplantation. A 53% increase in mechanical thresholds was observed following adrenal transplants along with a 70% reduction in the area of skin targeted for excessive grooming. These behaviors were not affected in 11 animals receiving transplants of skeletal muscle. The effects of adrenal transplants on cold allodynia consisted of a stabilization of response latencies in contrast to the continued decrease in latencies, i.e., increased sensitivity, following transplants of skeletal muscle. The results are consistent with previous studies showing the therapeutic efficacy of adrenal chromaffin cell transplants in neuropathic pain, and support the use of this treatment strategy for the alleviation of chronic pain following spinal cord injury.
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PMID:Effects of adrenal medullary transplants on pain-related behaviors following excitotoxic spinal cord injury. 966 85

The effects of exercise on morphine-induced analgesia were examined in male and female Long-Evans rats. In Experiment 1, 10 male rats were housed in standard laboratory cages, and 10 in activity wheels for 20 days prior to nociceptive testing. Pain thresholds were assessed using a tail-flick (TF) procedure. Morphine sulfate was administered using a cumulative dosing procedure (2.5, 5.0, 7.5, 10.0, 12.5, and 15.0 mg/kg). TF latencies were measured immediately prior to and 30 min following each injection. In Experiment 2, morphine-induced analgesia was examined in females in an identical manner to that of Experiment 1. Additionally, to determine if the attenuation of morphine-induced analgesia was permanent or reversible, after the initial test nociceptive test, previously active female rats were placed in standard cages, and previously inactive females placed in running wheels for 17 days prior to a second nociceptive test. Baseline TF latencies were significantly shorter in active male rats than in inactive animals. Additionally, both active male and female rats displayed decreased morphine-induced analgesia relative to inactive controls. Moreover, females that had been inactive and then were permitted to run showed a suppression in morphine-induced analgesia relative to presently inactive rats, and to their own nociceptive responses when sedentary. In contrast, morphine-induced analgesia in initially active females who were housed in standard cages during part 2 of Experiment 2 was enhanced relative to their first nociceptive test and to presently active rats. Experiment 3 examined the effects of short-term (24 h) running on antinociception. Baseline TF latencies were shorter in active rats than inactive rats. However, no differences in morphine-induced analgesia were observed as a function of short-term exposure to exercise. Experiment 4 investigated whether differences in body weight contributed to the differences in morphine-induced analgesia between chronically active and inactive animals. %MPEs did not vary among male rats maintained at 100, 85, or 77% of their free-feeding body weight. These results indicate that chronic activity can decrease morphine's analgesic properties. These effects may be due to crosstolerance between endogenous opioid peptides released during exercise and exogenous opioids.
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PMID:Chronic running-wheel activity decreases sensitivity to morphine-induced analgesia in male and female rats. 971 3

Evans blue accumulated in parotid glands of conscious rats in response to feeding (over 60 min), in the absence of atropine and adrenoceptor antagonists and in their presence, and after pretreatment with the sensory neurotoxin capsaicin. Stimulation of the auriculo-temporal nerve (40 Hz, 10 or 20 min), without and with the blockers, caused Evans blue to accumulate. A periglandular oedema also contained the dye. Administration (i.v.) of neurokinin A accumulated Evans blue, while substance P, vasoactive intestinal peptide (VIP), pituitary adenylate cyclase-activating peptide (PACAP), calcitonin gene-related peptide (CGRP) and pilocarpine lacked effect. Pilocarpine enhanced the action of neurokinin A and, furthermore, substance P combined with either VIP, PACAP or CGRP resulted in accumulation of Evans blue. In the sublingual + submandibular glands, Evans blue increased in response to neurokinin A and pilocarpine; furthermore, substance P and VIP, and substance P and CGRP, interacted positively. Bradykinin lacked effect in the glands. Comparisons were made with the urinary bladder. Accumulation of Evans blue reflects plasma protein extravasation. In salivary glands, the phenomenon occurred during feeding and was independent on intact sensory innervation; instead, the parasympathetic innervation containing the neuropeptides was in focus. In the clinic, the present findings may have implications for the aetiology of gland swelling and pain.
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PMID:Vascular protein leakage in the rat parotid gland elicited by reflex stimulation, parasympathetic nerve stimulation and administration of neuropeptides. 980 4

More than 50 surgical procedures have been described for treatment of chronic lateral ankle instability. Anatomic repairs have come into favor in the recent literature based on short-term studies, which have used objective measures for outcome. A long-term (range, 7-20 years; average, 12.6) patient-oriented outcome analysis was performed on 20 patients that underwent a modified Evans procedure for chronic lateral ankle instability by the senior author over a 13-year period. There was a 91% follow-up on all located patients (20 of 22). All patients had mechanical and functional instability, and all had failed conservative therapy. A questionnaire, based on the outcomes questionnaire developed by the American Academy of Orthopaedic Surgeons was used to determine functional stability. The patient's ability to perform recreational or competitive sporting activities at specific time intervals were also assessed (preinjury, 1 year postoperatively, present time). Overall result was considered satisfactory if five criteria were met: patents (a) were happy with the outcome of surgery, (b) were able to perform desired level of activities, (c) had functional stability, (d) were pain free performing desired level activities, (e) would undergo procedure again. The entire cohort demonstrated satisfactory results in 19 (95%) of 20 respondents at 1 year and 17 (85%) at present time. Grouping patients into competitive (12 cases) and recreational (eight cases) athletes demonstrated six of 12, and seven of eight reached their preinjury level (p = 0.074). In this study, we showed that surgical reconstruction using a modified Evans procedure is a reliable and effective treatment for chronic lateral instability. This procedure has proved to stand the test of time, as demonstrated by a patient-oriented outcome analysis. The elite athlete may be better served by a procedure using the principles of anatomic rather than augmented repair; however, the long-term data to our knowledge has yet to be published.
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PMID:Long-term patient-oriented outcome study of a modified Evans procedure. 982 Nov 36

Between the years 1991 and 1996, 13 patients with stage 2 or 3 tibialis posterior dysfunction were evaluated following surgical reconstruction. Those patients with posterior tibial tendon tendinitis with a progressive flatfoot were categorized as having a stage 2 deformity according to Mueller's developmental stages of tibialis posterior dysfunction. Those patients with increasing severity of symptoms including a forefoot abductus component were classified as stage 3. There were five patients in stage 2, ranging in age from 53 to 80 years old; and there were eight patients in stage 3, ranging in age from 41 to 73 years old. Standard conservative care was utilized prior to surgical intervention in all cases. Follow-up was 12 months to 63 months. Patients in stage 2 underwent a Cobb reconstruction utilizing a split tibialis anterior tenodesis, and patients in stage 3 underwent an Evans lateral column-lengthening procedure combined with a Cobb procedure. Utilizing retrospective radiographic evaluation and patient interviews, results indicated that patients in stage 2 had a better patient satisfaction than those patients in stage 3. Although both patient groups had a 6-point average decrease in pain according to the 0- to 10-point visual analog pain scale, 50% of the patients undergoing a Cobb-Evans procedure felt that the procedure did not meet their expectations. Only one out of the five Cobb procedure patients felt that the procedure did not meet his expectations. The results of this limited study of patients with stage 3 tibialis posterior dysfunction suggest that although the lateral column lengthening with tendon augmentation renders good radiographic correction, many patients develop protracted lateral column pain and felt that surgery did not meet their expectations. Additional calcaneal osteotomies and arthrodesing procedures of the hindfoot may render a more satisfactory outcome.
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PMID:Outcomes for surgical correction for stages 2 and 3 tibialis posterior dysfunction. 987 41


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