Biomedical subjects

Thomas Lundeberg

Publications and source records attributed to Thomas Lundeberg.

52 records · Page 3Linked to original sources

PubMed2003

Perceptual matching for assessment of itch; reliability and responsiveness analyzed by a rank-invariant statistical method.

The aim of this study was to evaluate the reliability and responsiveness of a new device-perceptual matching by Matcher (Cefar Medical AB, Lund, Sweden)-in the assessment of the progress of experimentally induced itch as well as determine the reliability of the method in patients with skin disease and itch. The perceptual matching unit electrically stimulates the skin of the fingers in the left hand. When the amplitude of the sensation corresponded to that of the experienced itch, the subject was instructed to halt the stimulation and a value was automatically saved in the electronic device. A total of 36 healthy subjects and nine patients participated in the study. The healthy subjects were asked to rate the level of itch every 30 s during the first 5 min and thereafter every minute. The reliability was determined in a test-retest procedure of the time points 5, 10, and 15 min after induction of itching. To test the stability of the method, the first sensation of pain in healthy subjects without itch was determined every 10th minute during 60 min. In patients, the test-retest procedure was repeated within 5 min. Perceptual matching was found to be a reliable method of itch assessment, with no evidence for random individual disagreement between the assessments. The augmented rank order coefficient ra was excellent: 1.00 at 5 min; 0.99 at 10 min; and 1.00 at 15 min. There was a clear indication of responsiveness for detecting changes in itch over time, p<or=0.05. The perceptual matcher device can detect immediate changes in perceived itch and is also sensitive to gradual decreases after the induction of itch. The first sensation of pain in healthy subjects without itch was unaffected when assessed every 10th minute during 60 min. In patients, no evidence for random disagreement or systematic disagreement by group between repeated assessments was detected. The augmented rank order coefficient was high (0.98). In conclusion, Matcher measures itch intensity via perceptual matching with a high reliability and excellent responsiveness. The method is stable and can be recommended as an assessment tool for itch intensity both in experimental conditions as well as in patients with skin disease and itch.

Adult↗

PubMed2003

Electro-acupuncture as a peroperative analgesic method and its effects on implantation rate and neuropeptide Y concentrations in follicular fluid.

BACKGROUND: In a previous study on the effect of electro-acupuncture (EA) in combination with a paracervical block (PCB) as an analgesic method during oocyte aspiration in IVF treatment, EA appeared to increase the pregnancy rate. This study was designed to test the hypothesis that EA as an analgesic during oocyte aspiration would result in: (i) a better IVF pregnancy rate than with alfentanil; (ii) peroperative analgesia that was as good as that produced by alfentanil; (iii) less postoperative abdominal pain, nausea and stress; and (iv) a reduction in the use of additional analgesics. Neuropeptide Y (NPY) concentrations in follicular fluid (FF) were analysed when possible. METHODS AND RESULTS: In this prospective, randomized, multicentre clinical trial, 286 women undergoing oocyte aspiration were randomly allocated to the EA group (EA plus a PCB) or to the alfentanil group (alfentanil plus a PCB). No significant differences were found between the EA and alfentanil groups in any of the IVF variables. NPY concentrations in FF were significantly higher in the EA group compared with the alfentanil group. No correlation between pregnancy rate and NPY concentrations was found in either analgesic group. Both EA plus a PCB and alfentanil plus a PCB induced adequate peroperative analgesia during oocyte aspiration evaluated using the visual analogue scale. After 2 h, the EA group reported significantly less abdominal pain, other pain, nausea and stress than the alfentanil group. In addition, the EA group received significantly lower amounts of additional alfentanil than the alfentanil group. CONCLUSION: EA does not improve pregnancy rate in the present clinical situation. The observation that NPY concentrations in FF were higher in the EA group may be important for human ovarian steroidogenesis. The analgesic effects produced by EA are as good as those produced by conventional analgesics, and the use of opiate analgesics with EA is lower than when conventional analgesics alone are used.

Acupuncture Analgesia↗

PubMed2003

Pain in a Swedish spinal cord injury population.

OBJECTIVE: To describe pain and associated variables in a prevalence group of persons with a sustained spinal cord injury (SCI) in the Swedish capital and its surroundings. SETTING: Spinalis SCI Unit (outpatient clinic), Stockholm, Sweden. DESIGN: Assessment over a 12-month period in a yearly health control. SUBJECTS: Four hundred and fifty-six SCI patients. RESULTS: Two hundred and ninety-one out of 456 SCI patients (63.7%) suffered from pain, and in 45.7% of these it was classified as being neurogenic. Aching pain was the most used descriptor (38.5%). The onset of pain was commonly within three months (73.5%). In 70.4% of patients pain occurred below the level of the lesion. Most patients identified pain as coming from one (55.0%) or two (28.2%) body regions. Rating of the general pain intensity on a visual analogue scale (VAS) was 46 out of 100 and rating of the worst pain intensity was 78 out of 100. Ninety-four out of 276 patients (32.3%) considered that their quality of life was significantly affected by pain. CONCLUSION: Pain was most common in patients with incomplete lesions (ASIA impairment grade D) and there was a correlation between pain and higher mean age at injury and between pain and female gender.

Adolescent↗

PubMed2002

Social stress blocks energy conservation in rats exposed to an oxytocin-injected cage mate.

We previously found stress-reduction in rats exposed to an oxytocin-injected cage-mate. Olfactory impairment and oxytocin antagonist treatment blocked the effect. Here, we investigated effects of social stress on the exposure-induced response and exposure on amygdaloid oxytocin concentrations. CT concentrations in exposed olfactorily impaired, CT antagonist-treated and saline-injected unexposed rats were reduced, compared to the significantly higher level in untreated and exposed saline-injected rats. Saline injections and group mixing enhanced heat dissipation. Exposure abolished the injection-induced, but not mixing-induced stress response, most likely via a social stress induced effect on the oxytocin-injected rat. The difference in exposure responsivity may relate to recognition, stress type and intensity affecting different stress-response systems. The mechanism could reinforce social attachment.

Amygdala↗

PubMed2002

Energy conservation in stressed rats exposed to an oxytocin-injected cage mate.

In previous studies we found indications of stress reduction in saline-injected rats when exposed to an oxytocin (OT)-injected cage mate. Olfactory impairment and OT antagonist treatment abolished the effects. This suggested an olfactorily mediated oxytocinergic stress-inhibitory mechanism. To test this hypothesis bodyweight, tail skin temperatures, food-intake and plasma ACTH and corticosterone concentrations were analysed. Suppressed weight loss and decreased stress-hormone release was found in saline-injected rats exposed to an OT-injected cage mate, but not in OT antagonist-injected rats, supporting the hypothesis. Our results suggest that OT in a stressed animal can inhibit the olfactory stress cues emitted, and that the olfactory cues from the stressed animal can influence an OT in pathway in the odour recipient animals to reduce stress effects.

Adrenocorticotropic Hormone↗

PubMed2002

Blockade effect of mu and kappa opioid antagonists on the anti-nociception induced by intra-periaqueductal grey injection of oxytocin in rats.

Intra-periaqueductal grey (PAG) injection of 1 nmol of oxytocin induced significant increases in hindpaw withdrawal latency (HWL) to thermal and mechanical stimulation in rats. The anti-nociceptive effect of oxytocin was attenuated significantly by subsequent intra-PAG injection of the mu opioid antagonist beta-funaltrexamine (beta-FNA) and the kappa opioid antagonist nor-binaltorphimine (nor-BNI), but not by the delta antagonist naltrindole. The results demonstrated that mu and kappa opioid receptors, not delta receptors, were involved in the oxytocin-induced anti-nociception in PAG of rats.

Analgesics↗

PubMed2002

Alteration in endogenous opioid systems due to chronic inflammatory pain conditions.

The influence of chronic arthritic pain on two endogenous opioid peptides, dynorphin B and [Met5]enkephalin-Arg6-Phe7, and multiple opioid receptors in discrete brain, lumbar spinal cord and pituitary pools was investigated. Using radioimmunoassay and receptor binding assay, we examined the changes in regional opioid peptide levels and opioid receptor activity due to chronic inflammation in adjuvant arthritic rats. At 4 weeks post-inoculation, increased levels of immunoreactive dynorphin B and [Met5]enkephalin-Arg6-Phe7 were measured in tissues of arthritic rats compared with controls. No significant changes in mu-, delta- or kappa-opioid receptors were seen after chronic inflammation. Taken together, these results indicate that in chronic arthritis, opioid receptor changes do not follow the peptide alterations of pro-dynorphin and pro-enkephalin systems. Thus, dynamic modification and modulation of nociceptive information takes place during chronic inflammation. This supports the key role of the central nervous system in chronic inflammatory pain conditions.

Animals↗

PubMed2002

Role of calcitonin gene-related peptide and its antagonist on the evoked discharge frequency of wide dynamic range neurons in the dorsal horn of the spinal cord in rats.

The present study was performed to explore the effect of calcitonin gene-related peptide (CGRP) and its antagonist CGRP8-37 on the evoked discharge frequency of wide dynamic range (WDR) neurons in the dorsal horn of the spinal cord in rats. Recording was performed with a multibarrelled glass micropipette and the chemicals were delivered by iontophoresis. The discharge of WDR neurons was evoked by transdermic electrical stimulation applied on the ipsilateral hindpaw. (1) Iontophoretic application of CGRP at an ejection current of 100 nA increased the discharge frequency of WDR neurons significantly. (2) Iontophoretic application of CGRP8-37 at an ejection current of 80 or 160 nA induced significant decreases in the discharge frequency of WDR neurons, but not at 40 nA. (3) Iontophoretic application of CGRP8-37 not only antagonized the CGRP-induced increase in the evoked discharge frequency of WDR neurons but also induced a significant decrease in the evoked discharge frequency of WDR neurons compared to basal levels. The results indicate that CGRP and its receptors play a facilitary role on the transmission and/or modulation of nociceptive information in the dorsal horn of the spinal cord in rats.

Animals↗

PubMed2002

NGF modulates CGRP synthesis in human B-lymphocytes: a possible anti-inflammatory action of NGF?

We investigated whether the sensory neuropeptide, calcitonin gene-related peptide (CGRP), could be synthesised by human lymphocytes. Our results indicate that in activated B-cells, there is a strong expression of CGRP gene transcripts, which is almost absent in resting cells. Since B-cells autocrinally produce NGF, the neutralisation of endogenous NGF by anti-NGF antibodies resulted in a marked reduction in CGRP expression in both resting and activated B-cells. Thus, NGF appears to directly affect the synthesis of CGRP in B-cells as in sensory neurons. By regulating CGRP synthesis in lymphocytes and neuronal cells, NGF can influence the intensity and duration of the immune response.

Anti-Inflammatory Agents↗

PubMed2002

Sensory stimulation (TENS): effects of parameter manipulation on mechanical pain thresholds in healthy human subjects.

Transcutaneous electrical nerve stimulation (TENS) is a popular form of electrostimulation. Despite an extensive research base, there remains no consensus regarding the parameter selection required to achieve maximal hypoalgesic effects. The aim of this double blind, sham-controlled study was to investigate the relative hypoalgesic effects of different TENS parameters (frequency, intensity and stimulation site) upon experimentally induced mechanical pain. Two hundred and forty participants were recruited in order to provide statistical analysis with 80% power at alpha = 0.05. Subjects were randomised to one of the six TENS groups, a control, and a sham TENS group (n = 30, 15 males, 15 females, per group). TENS groups differed in their combinations of stimulation; frequency (4 or 110 Hz), intensity ('to tolerance' or 'strong but comfortable') and stimulation site (segmental--over the distribution of the radial nerve or, extrasegmental--over acupuncture point 'gall bladder 34', or a combination of both segmental and extrasegmental). Pulse duration was fixed at 200 micros. Stimulation was delivered for 30 min and subjects were then monitored for a further 30 min. Mechanical pain threshold (MPT) was measured using a pressure algometer and taken from the first dorsal interosseous muscle of the dominant hand, ipsilateral to the stimulation site. MPT measures were taken, at baseline, and at 10-min intervals for 60 min. Difference scores were analysed using repeated measures and one-way ANOVA and relevant post hoc tests. Low frequency, high intensity, extrasegmental stimulation produced a rapid onset hypoalgesic effect, which increased during the stimulation period (P < 0.0005 control and sham) and was sustained for 30 min post-stimulation (P < 0.0005(control), P = 0.024(sham)). Whilst high frequency, 'strong but comfortable' intensity, segmental stimulation produced comparable hypoalgesic levels during stimulation, this effect was not sustained post-stimulation. Stimulation at a combination of the two sites did not produce any greater hypoalgesic effects. These results may have implications for the clinical use of sensory stimulation.

Acupuncture↗

PubMed2002

Repeated massage-like stimulation induces long-term effects on nociception: contribution of oxytocinergic mechanisms.

Massage-like stroking induces acute antinociceptive effects that can be reversed by an oxytocin antagonist, indicating activation of oxytocin on endogenous pain controlling systems. We now demonstrate an increase in hindpaw withdrawal latencies (HWLs), in response to thermal and mechanical stimuli, which was present after six treatments of massage-like stroking every other day and which continued to increase through the remaining seven treatments. Repeated massage-like stroking also resulted in increased oxytocin-like immunoreactivity (oxytocin-LI) levels in plasma and periaquaductal grey matter (PAG). Furthermore, increases in HWLs were also present after injections of oxytocin into the PAG (0.1, 0.5 and 1.0 nmol). Intra-PAG oxytocin injection of 1 nmol followed by 1 or 20 nmol of naloxone attenuated the increments in HWL. Also, there was a dose-dependent attenuation of the oxytocin-induced antinociceptive effects following intra-PAG injection of the mu-opioid antagonist beta-funaltrexamine (beta-FNA) and the kappa-opioid antagonist nor-binaltorphimine (nor-BNI) but not the delta-antagonist naltrindole. The long-term antinociceptive effects of massage-like stroking may be attributed, at least partly, to the oxytocinergic system and its interaction with the opioid system, especially the mu- and the kappa-receptors in the PAG.

Afferent Pathways↗

PubMed2002

Sensory stimulation (acupuncture) for the treatment of idiopathic anterior knee pain.

A randomized controlled study was conducted to evaluate the effect of acupuncture treatment in idiopathic anterior knee pain, a pain syndrome without known aetiology. Fifty-eight patients, clinically and radiologically examined, were randomly assigned to either deep or minimal superficial acupuncture treatment. The patients were treated twice weekly for a total of 15 treatments. The main outcome measurements were one leg vertical jump, functional score, daily VAS recording and skin temperature. Fifty-seven patients completed the study. Pain measurements on VAS decreased significantly within both groups; in the deep acupuncture group from 25 before treatments to 10 afterwards, and in the superficial (placebo) acupuncture group from 30 to 10. There was no significant difference between the groups. The improvement on the VAS recordings remained significant even after 3 and 6 months. Even though the pain decreased after sensory stimulation, neither the ability to jump on one leg, the functional score nor the skin temperature changed. This study shows that patients with idiopathic anterior knee pain benefit from both electroacupuncture treatment and subcutaneous needling. The pain-relieving effect remains for at least 6 months. Central pain inhibition, caused by either afferent stimulation or by non-specific therapeutic (placebo) effects, is a plausible explanation behind the treatment effects.

Acupuncture Analgesia↗

PubMed2002

Alternative treatments in reproductive medicine: much ado about nothing. Acupuncture-a method of treatment in reproductive medicine: lack of evidence of an effect does not equal evidence of the lack of an effect.

The increasing popularity of alternative treatments-methods of treatment that are not generally established in Western medicine-demands a serious debate about scientific documentation, efficacy and safety. It has been argued that there is no alternative medicine. There is only scientifically proven, evidence-based medicine supported by solid data, and we agree. Different methods of treatment, referred to as alternative treatments, are used by millions of patients every day which generates billions of dollars in health care expenditure each year. Therefore, it is important that physicians become more knowledgeable about different methods of treatment and increase their understanding of the possible benefits and limitations of each therapy. This article is intended to illustrate acupuncture in reproductive medicine today, as an example of a method of treatment that has become more established in Western medicine over the last decade. Discussed are the scientific documentation and aspects of acupuncture research, the physiological basis for the use of acupuncture, and evidence for the use of acupuncture in reproductive medicine. We are well aware that there are few well-designed papers on the effectiveness of different treatments in this field. However, we need to adhere to these principles, as we hope, do the readers of the present debate article.

Acupuncture↗

PubMed2002

A new highly reliable instrument for the assessment of pre- and postoperative gynecological pain.

UNLABELLED: In this study, we evaluated the reliability of a newly developed method for pain assessment, which is based on perceptual matching by Pain Matcher, Cefar Medical AB, Lund, Sweden, during minor gynecological surgery. In addition, the responsiveness to two different anesthetic methods-electro-acupuncture or a fast-acting opiate, alfentanil, both in combination with a paracervical block-was estimated by using Pain Matcher and visual analog scale (VAS) assessments before and 2 h after surgery. Two hundred-twenty-three women (aged 22-38 yr) participated. The results show that Pain Matcher is a reliable method for pain assessments, with lack of random individual disagreement and with no statistical evidence of systematic disagreement in position or in concentration. The augmented rank-order coefficient (r(a)) values were excellent (0.95-1.00). When scales were used to detect true changes over time, there was no clear indication of responsiveness, mostly because of statistically significant random individual changes. However, the individual changes were much smaller for magnitude matching than for VAS. In conclusion, we would recommend the use of perceptual matching by Pain Matcher for pain assessment, because in this study it was a reliable and powerful in test-retest situations and had smaller individual changes than VAS after intervention. The Pain Matcher procedure was well accepted by the patients, and the results suggest that it may be useful when evaluating acute pre- and postoperative pain. IMPLICATIONS: We evaluated a new instrument for pain assessment. Our results show that this method is highly reliable, is well tolerated by the patients, is reported to be easy to use, and may be useful when evaluating acute pre- and postoperative pain.

Acupuncture Analgesia↗

PubMed1995

Systemic adenosine infusion: a new treatment modality to alleviate neuropathic pain.

Adenosine, an endogenous antinociceptive compound acting in the central nervous system, was infused intravenously (50-70 micrograms/kg/min) to 2 patients with peripheral neuropathic pain. In 1 subject, spontaneous pain was alleviated, and tactile allodynia was essentially relieved during 40 min of infusion. Allodynia to warmth and touch were abolished in the other subject. In addition, hyperalgesia to pinprick was markedly attenuated as was pressure-induced allodynia. The reported effects lasted for hours after termination of the infusion. Our preliminary encouraging data call for further controlled studies of the potentially relieving effect of adenosine in painful neuropathic conditions.

Adenosine↗

PubMedDate not supplied

Evaluation of variations in sensory and pain threshold assessments by electrocutaneous stimulation.

Assessed sensory and pain thresholds can change consequently to disturbances associated with ongoing pain. Such assessments could be an additional method in the daily clinical evaluation of perceived pain. To study the test-retest variability within-day and between-day of such procedures a newly developed instrument producing electrocutaneous stimulation, PainMatcher (PM), was used to assess the electrical sensory thresholds (EST) and pain thresholds (EPT) in healthy volunteers and in patients with pain. The produced data were considered ordinal and analyzed with rank-invariant statistics with properties of analyzing systematic disagreement, bias, and individual variations. The percentage agreements within +/- 1PM value for EST were in the two groups of healthy volunteers and patients in pain 94% and 92%, and for EPT assessments 49% and 78%, respectively. The variability in the EST assessments is possibly explained by a slight bias while the individual variations were negligible between the two occasions. The assessed EPT were unbiased in both groups while individual variations were significant among the healthy volunteers but negligible among the patients in pain. The EST was found to be increased in pain patients compared to healthy volunteers, p < 0.03, and the EPT decreased in pain patients compared to healthy volunteers, p < 0.001. The results in this study indicate stable and reliable assessments of EST and EPT except for a possible bias. The threshold assessment procedure followed in this study may be a valuable tool in the clinical evaluation of sensory and pain assessments in pain patients.

Case-Control Studies↗