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Biomedical subjects

A Ekblom

Publications and source records attributed to A Ekblom.

At least 37 records · Page 2Linked to original sources
PubMed1995

Systemic adenosine attenuates touch evoked allodynia induced by mustard oil in humans.

The effect of adenosine on tactile allodynia (secondary hyperalgesia) was studied in 6 healthy volunteers, using a double-blind, placebo controlled, cross-over design. Tactile allodynia was induced by topical application of mustard oil on the skin of the volar aspect of the forearm. Adenosine (50 micrograms kg-1 min-1) or saline was given intravenously for 20 min before the mustard oil application and continued for another 50 min. The tactile allodynic areas for brush and von Frey filament stimulation were both significantly reduced by approximately 50% during adenosine infusion, compared with placebo. The threshold for eliciting allodynia with von Frey filaments was not influenced by adenosine. The study shows that adenosine can reduce the area of mustard oil induced tactile allodynia.

Adenosine↗
PubMed1995

Peroperative adenosine infusion reduces the requirements for isoflurane and postoperative analgesics.

The aims of this study were to investigate the influence of adenosine infusion, firstly, on postoperative analgesic requirements, and secondly, on peroperative isoflurane requirements. Seventy-five women, aged 18-70 yrs, ASA grades I and II, scheduled for breast surgery, were randomly assigned to peroperatively receive a double-blind intravenous infusion of either adenosine, 80 micrograms.kg-1.min-1, or placebo, during surgery under isoflurane/N2O/O2 anesthesia. The peroperative isoflurane requirements were significantly reduced at 30 and 90 min of surgery during adenosine treatment. The number of patients reporting pain when regaining consciousness after surgery was reduced by 57% in the adenosine group, 8/31 vs 19/32 (P < 0.02). Further, the postoperative 24-h opioid requirements were reduced by 27% in the adenosine group (P < 0.03). In conclusion, we found that a peroperative infusion of a small dose of adenosine during breast surgery, reduces the peroperative anesthetic requirements, and the demand for post-operative analgesics.

Adenosine↗
PubMed1995

Adenosine increases the cutaneous heat pain threshold in healthy volunteers.

Adenosine is an endogenously produced substance which in animal experiments exerts anti-nociceptive effects. In humans, algesic effects have been presented following exogenous adenosine administration. A recent study on anaesthetized patients, however, suggested an anti-nociceptive effect during i.v. adenosine. We have studied the pain-reducing effect in healthy volunteers using adenosine 50-80 micrograms.kg-1.min-1 (n = 10), morphine 0.1 mg.kg-1 (n = 5), adenosine 50 micrograms.kg-1.min-1 + morphine 0.1 mg.kg-1 (n = 6), and ketamine 0.1 mg.kg-1 (n = 5); all drugs given i.v., single-blind. Quantitative sensory tests (QST) revealed a significantly increased cutaneous heat pain threshold following adenosine. No effect was seen following ketamine or morphine. Suprathreshold heat pain perception was unchanged in all subjects. Furthermore, warm and cold perception thresholds were not influenced significantly by any drug. Adenosine, morphine and ketamine produced well-known side-effects but of a mild intensity not necessitating any treatment. The present results show that i.v. adenosine can provide a modest but selective increase of cutaneous heat pain thresholds, suggesting a pain-reducing capacity of adenosine in humans.

Adenosine↗
PubMed1994

Effects of electro-acupuncture and physical exercise on regional concentrations of neuropeptides in rat brain.

The effects of single or repeated treatments with manual acupuncture (ACU), electro-acupuncture (ELACU) or physical exercise on neuropeptide Y (NPY), neurokinin A (NKA), substance P (SP), galanin (GAL) and vasoactive intestinal peptide (VIP)-like immunoreactivity (-LI) in different regions of the rat brain were studied. Initially the effect of microwave irradiation (MWI) was compared to decapitation on the recovery of neuropeptides, and significantly higher concentrations of SP-LI, NKA-LI and NPY-LI were found in the hippocampus, occipital cortex, pituitary and striatum following MWI. Repeated ELACU treatments significantly increased SP-LI, NKA-LI and NPY-LI in the hippocampus and NPY-LI in the occipital cortex. No changes were found in animals receiving ACU or performing physical exercise.

Acupuncture Therapy↗
PubMed1994

The effect of a single intraperitoneal dose of hrIL-1 alpha on substance P-, neurokinin A-, calcitonin gene-related peptide- and neuropeptide Y-like immunoreactivity in cerebrospinal fluid, plasma and knee joint synovial fluid in the rat.

Substance P (SP)-, neurokinin A (NKA)-, calcitonin gene-related peptide (CGRP)- and neuropeptide Y (NPY)-like immunoreactivity (-LI) was studied in rats' cerebrospinal fluid (CSF), plasma and synovial fluid (SF) from both knee joints at 2 and 24 h following an intraperitoneal administration of 0.05 ml human recombinant interleukin-1 alpha (i.p. hrIL-1 alpha) or saline. Increased or decreased levels of SP-, NKA and CGRP-LI were detected in CSF and plasma, whereas NPY-LI was unaffected. In SF only CGRP-LI increased bilaterally. There was a correlation in CGRP-LI content between plasma and CSF following i.p. hrIL-1 alpha but not between plasma and SF or CSF and SF. It can be concluded that (1) i.p. hrIL-1 alpha activates somatosensory afferents thereby increasing SP- and CGRP-LI content in CSF and plasma and NKA-LI in CSF; 2) i.p. hrIL-1 alpha induces a bilateral increase of CGRP-LI in SF which is not mediated through systemic circulation and is possibly a part of the general host defensive reaction.

Animals↗
PubMed1994

Substance P-, neurokinin A-, calcitonin gene-related peptide- and neuropeptide Y-like immunoreactivity (-LI) in rat knee joint synovial fluid during acute monoarthritis is not correlated with concentrations of neuropeptide-LI in cerebrospinal fluid and plasma.

In a recent study we have shown a bilateral release of substance P (SP)-, neurokinin A (NKA)-, calcitonin gene-related peptide (CGRP)- and neuropeptide Y (NPY)-like immunoreactivity (-LI) in rat synovial fluid during acute monoarthritis. In order to elucidate the mechanisms underlying these phenomena, we examined the correlation between neuropeptide-LI in rat cerebrospinal fluid (CSF) and synovial fluid and between plasma and synovial fluid following the intra-articular injection of equal volumes (0.05 ml) of either Freund's adjuvans, carrageenan 2%, substance P 10(-5) M or human recombinant interleukin-1 alpha. Control rats were given saline intra-articularly. CSF, plasma and synovial fluid from the knee joints were obtained at 2, 6 and 24 h after injection and were analysed by specific radioimmunoassays. The intra-articular injection of pro-inflammatory substances induced changes in neuropeptide-LI in synovial fluid, CSF and plasma. However, there was no correlation between neuropeptide-LI in synovial fluid and plasma or between synovial fluid and CSF. The results of the present study does not support the hypothesis that the bilateral changes in neuropeptide-LI in synovial fluid were due to a release of neuropeptides from the inflamed joint into the systemic circulation. However, in carrageenan induced inflammation there was a tendency towards a correlation in SP-LI between CSF and synovial fluid suggesting that central neurogenic mechanisms should be studied in order to explain the bilateral changes seen.

Acute Disease↗
PubMed1994

The influence of adenosine, ketamine, and morphine on experimentally induced ischemic pain in healthy volunteers.

Adenosine, intrathecally administered, produces antinociception in experimental studies on animals. The effect of intravenous (i.v.) adenosine on experimentally induced pain in humans has not been studied. The present single-blind, randomized, placebo-controlled study was conducted in nine healthy volunteers. The pain-reducing effects of adenosine (70 micrograms.kg-1.min-1 i.v.), morphine (0.1 mg/kg i.v.), ketamine (0.1 mg/kg i.v.), adenosine + morphine, and adenosine + ketamine were compared to each other and to placebo in random order. Ischemic pain was induced by the submaximum effort tourniquet technique. Pain was assessed using the visual analog scale (VAS, 0-100 mm). The sums of pain scores (SPS) were compared and found significantly 30%-40% lower for adenosine as well as for the other compounds and combinations (P < 0.03), compared to placebo. The number of subjects who reached VAS 100 within 30 min was significantly lower (P < 0.03) when receiving adenosine + morphine (0/9) and adenosine + ketamine (2/9) than when receiving placebo (7/9). This may indicate an additive effect on pain reduction when adenosine is given in combination with morphine or ketamine. In conclusion, the results indicate that i.v. adenosine, as well as morphine and ketamine, can reduce experimentally induced ischemic muscle pain in healthy volunteers.

Adenosine↗
PubMed1993

Bilateral changes of substance P-, neurokinin A-, calcitonin gene-related peptide- and neuropeptide Y-like immunoreactivity in rat knee joint synovial fluid during acute monoarthritis.

It has been hypothesized that the nervous system contributes to the symmetrical response in rheumatoid arthritis. In order to elucidate this, the bilateral concentrations of substance P-like immunoreactivity (SP-LI), neurokinin A-LI (NKA-LI), calcitonin gene-related peptide-LI (CGRP-LI) and neuropeptide Y-LI (NPY-LI) in rat synovial fluid during acute monoarthritis were studied. Equal volumes (0.05 ml) of either Freund adjuvants, carrageenan 2%, substance P 10(-5) M or human recombinant interleukin-1 alpha were injected into the right and saline into the left knee joint. Control rats were given saline bilaterally. Perfusates were obtained from both knees simultaneously at 2, 6 and 24 h after injection and were analysed by specific radioimmunoassays. Increase of SP-, NKA-, CGRP- and NPY-LI in synovial fluid occurred in both knees after injections with the pro-inflammatory substances into the right joints as compared to controls, except for unchanged SP-LI in the right knee joint after 24 h following hrIL-1 alpha injection. There was, however, generally no significant difference in the peptide contents between the right knee (injected with pro-inflammatory substance) as compared to the left knee (given saline) at 2, 6 or 24 h after injection except at three occasions. The results show that experimentally induced monoarthritis induces bilateral changes in synovial fluid peptide content.

Acute Disease↗
PubMed1993

Is intra-articular pethidine an alternative to local anaesthetics in arthroscopy? A double-blind study comparing prilocaine with pethidine.

We investigated the per- and postoperative pain-reducing effect of pethidine given intra-articularly (i. art.). Thirty patients subjected to knee joint arthroscopy, diagnostic and surgical procedures, were randomly assigned to one of three groups. Group A consisted of ten patients who received 250 mg prilocaine + 200 micrograms adrenaline (i. art.) in a volume of 50 ml, group B of ten patients who received 200 mg pethidine (i. art.) in 50 ml saline, and group C of ten patients who received 200 mg pethidine + 200 micrograms adrenaline (i. art.) in 50 ml saline. During arthroscopy the patients reported on pain intensity and discomfort using visual analogue scales. Ratings were low and did not differ significantly between the three groups. Two of three patients in each group requested additional analgesics or sedatives due to pain and discomfort, but again with no difference between the three groups. Postoperatively all patients rated their pain intensity at rest and during movement (at 0, 1, 2, 3, 4, 5, 6, 12 and 24 h). The patients receiving pethidine (group B) reported significantly less pain at rest and movement than group A patients, in general at 1-4 h postoperatively. A significant difference was detected between groups B and C at 4 h postoperatively. Calculating the total sum of pain scores, patients receiving pethidine (group B) reported significantly less pain both at rest and during movement than those receiving prilocaine (group A). Furthermore, patients in group B used significantly less analgesics than those in group A. Adrenaline did not potentiate the effect of pethidine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Influence of calcitonin gene-related peptide on histamine- and substance P-induced itch, flare and weal in humans.

Recent data have shown both synergistic and inhibitory effects between calcitonin gene-related peptide (CGRP) and substance P (SP) on inflammation and flare responses. The modulatory effects of CGRP on the itch, flare and weal responses following intracutaneous injections of SP and histamine were studied in 10 healthy volunteers. The only change in itch responsiveness observed was a significant prolongation of itch latency following SP when preceded 10 min earlier by a CGRP injection. No influence on flare and weal was observed.

Adult↗
PubMed1992

Does a regional nerve block change cutaneous perception thresholds outside the anaesthetic area? Implications for the interpretation of diagnostic blocks.

The present study was performed on pain-free subjects and patients to analyse if local anaesthetics (LA) normally used for nerve blocks in the orofacial region resulted in generalised changes in cutaneous somatosensory perception thresholds outside the territory of the primarily blocked nerve. Five subjects received an intra-oral nerve block and 5 patients received epidural anaesthesia, serving as a reference group considering the larger amounts of LA used in this latter type of anaesthesia. No differences (after vs. prior to LA) were detected regarding thresholds to tactile, cold, warmth or heat pain stimuli in skin areas outside the regions directly blocked. This was also true for the difference limens between warm-cold thresholds. Our data do not indicate any generalised influence on tactile, thermal and pain perception thresholds in pain-free subjects.

Adult↗
PubMed1991

Increased postoperative pain and consumption of analgesics following acupuncture.

Acupuncture was given to patients before (preoperative-acupuncture group, PRE-ACU, n = 25) or after (postoperative-acupuncture group, POST-ACU, n = 25) operative removal of impacted mandibular third molars. Sixty patients did not receive acupuncture and participated as a control group (CG). All patients completed a questionnaire in order to characterize state tension and stress, degrees of neuroticism, extroversion, depression and psychosomatic disorders. We also recorded intraoperative discomfort and pain intensity, postoperative pain intensity and consumption of analgesics for 72 h. The PRE-ACU was significantly more tense following surgery and found the operative procedure more unpleasant than the other two groups. The PRE-ACU further rated intraoperative pain intensity higher than the CG and experienced higher pain intensity immediately postoperatively compared with POST-ACU and CG. Of the PRE-ACU patients 15/24 needed additional local anesthesia intraoperatively while none in the POST-ACU or CG requested extra lidocaine. Postoperatively patients in both PRE- and POST-ACU reported a higher total sum of pain scores (pain intensity) and the PRE-ACU consumed more analgesics compared with the CG. A significantly larger number of patients suffering from "dry socket" (a complication during wound healing) was found in both PRE- and POST-ACU compared with the CG. No correlation was found between assessed personality characteristics and reported postoperative pain/consumption of analgesics in any group and could thus not explain the observed differences between the groups. The reason for our unexpected "negative" findings is unclear but some hypothetical explanations are discussed.

Acupuncture Therapy↗
PubMed1991

Concentrations of neuropeptides substance P, neurokinin A, calcitonin gene-related peptide, neuropeptide Y and vasoactive intestinal polypeptide in synovial fluid of the human temporomandibular joint. A correlation with symptoms, signs and arthroscopic findings.

Arthroscopy was performed on 18 patients (19 joints) with temporomandibular joint arthropathy. Arthroscopic investigation revealed that 12 patients had disk derangement, including 3 patients with rheumatoid arthritis. Six patients had osteoarthrosis, including one patient with rheumatoid arthritis. Synovial fluid content of substance P-like immunoreactivity (SP-LI), neurokinin A (NKA-LI), calcitonin gene-related peptide (CGRP-LI), neuropeptide Y (NPY-LI) and vasoactive intestinal polypeptide (VIP-LI) were analysed using radioimmunoassay technique. All peptides analysed were found, although in various concentrations, in the different joints. There were no significant differences in concentrations of the peptides in the synovial fluid between patients in the various groups. No significant correlation was found between clinical symptoms and signs, arthroscopic findings, or use of analgesic/anti-inflammatory medication versus concentrations of peptides in the synovial fluid. In comparison with earlier findings in the knee joint significantly higher concentrations of SP-LI, CGRP-LI and NPY-LI were found in the TMJ.

Adult↗
PubMed1991

Concentration of substance P, neurokinin A, calcitonin gene-related peptide, neuropeptide Y and vasoactive intestinal polypeptide in synovial fluid from knee joints in patients suffering from rheumatoid arthritis.

We have studied the presence of five neuropeptides in knee joint synovial fluid from either patients suffering from rheumatoid arthritis and pain (n = 18) or being subjected to arthroscopy due to meniscal/cruciate ligament injuries (n = 13). Radioimmunoassay technique was used for peptide analysis using antisera SP2 against substance P (SP), K12 against neurokinin A (NKA), CGRPR8 against calcitonin gene-related peptide (CGRP), NPY1 against neuropeptide Y (NPY) and VIP2 against vasoactive intestinal polypeptide (VIP). No SP could be detected, and lower levels of NKA was found in arthritic joints vs controls. CGRP and NPY was found in higher concentrations in arthritic patients vs controls. VIP was found sporadically in both arthritis and control patients. Our data show some quantitative differences between patients suffering rheumatoid arthritis and pain, and patients with non-inflamed joints without pain; indicating an involvement of peptidergic fibers in arthritis in humans.

Adult↗
PubMed1991

Perception of histamine-induced itch elicited in three different skin regions.

In order to investigate whether any regional difference in itch perception exists in experimentally induced pruritus, various concentrations of histamine (1, 3.3, 10, 33 and 100 micrograms/ml) were injected intradermally in three different skin regions in 15 healthy subjects. The regions were 1) the volar aspect of the forearm, 2) the lateral aspect of the upper arm and 3) the upper back at scapular level. Itch perception (itch latency, itch duration, maximal itch intensity, 'total itch index') and flare reactions were studied. A significant dose-response relationship was shown in each of the three regions for all itch variables, except itch latency, and for the flare reactions. However, no significant regional difference in itch perception was observed. The flare reaction showed a regional variation, with significantly smaller flares on the forearm than in the other two regions.

Adolescent↗
PubMed1989

Immunoreactive tachykinins, calcitonin gene-related peptide and neuropeptide Y in human synovial fluid from inflamed knee joints.

We have analysed the concentrations of substance P (SP), neurokinin A (NKA), calcitonin gene-related peptide (CGRP) and neuropeptide Y (NPY) in the synovial fluid from 5 patients suffering from arthritis with inflamed knee joints as well as from 5 healthy control subjects with an earlier traumatic meniscal or cruciate ligament injury. Competitive radioimmunoassay was done using antisera SP2 (SP), K12 (NKA), R8 (CGRP), and NPY1 (NPY). No SP-like immunoreactivity (-LI) was detected in any patient. NKA-LI was found in all control patients but in none of the arthritis patients. CGRP-LI was seen in all arthritis patients as well as in 3/5 control patients, a non-significant difference. NPY-LI was found in a significantly higher concentration in the arthritis group vs the control patients. The results support an involvement of neuropeptides in human joint inflammation.

Adult↗
PubMed1989

Pain development and consumption of analgesics after oral surgery in relation to personality characteristics.

In the present study a survey has been performed of the pain development and analgesic intake in 100 patients following elective oral surgery of impacted third molars in relation to preoperative assessment of personality characteristics. Our results show that no sex differences existed preoperatively concerning personality characteristics, concerning postoperative pain development or analgesic consumption. Fourteen patients reported no pain at all and 40 patients did not use any analgesics in the postoperative period. We also found a good correlation between total sum of pain scores and analgesic intake. Patients undergoing surgery in the morning reported a lower total sum of pain scores, reported pain at fewer occasions and tended to require less analgesics than patients being subjected to surgery in the afternoon. The patients who reported a total sum of pain scores in the upper percentile during the postoperative period rated their general health worse, as rated on the General Health (GH) questionnaire, and used more analgesics than did patients in the lower percentile. Also, patients not using any analgesics reported less symptoms of distress according to the GH scale as compared to patients using analgesics. In general, however, less than 10% of the variance in postoperative pain and consumption of analgesics could be explained by the preoperative factors studied.

Adolescent↗