Biomedical subjects

Jan Persson

Publications and source records attributed to Jan Persson.

7 recordsLinked to original sources

PubMed2005

The effects of racemic ketamine on painful stimulation of skin and viscera in human subjects.

Evidence suggests that NMDA receptors may have a differential role in the modulation of visceral and somatic pain. Specifically, animal data indicate an analgesic role of NMDA-R antagonists in acute visceral but not acute somatic pain. In humans analgesic effects are documented in acute somatic pain, while the role of NMDA-R antagonists in acute visceral pain is still questionable. We, therefore, conducted a study in humans comparing the analgesic effects of ketamine in an experimental model of visceral and cutaneous pain. In a double-blind, randomized, cross-over study, 11 healthy volunteers (3M, 8F) participated in two experimental sessions in which they evaluated perceptions induced by balloon distention of the distal esophagus and contact heat on the upper chest during continuous computer-controlled i.v. infusion of either ketamine (60 and 120 ng/mL) or saline. Two stimulus intensities producing non-painful and painful sensation were used for each stimulus modality. Subjects reported maximum pain intensity and unpleasantness on visual analog scales (VAS). For noxious visceral stimulation, low dose ketamine produced significant attenuation of both pain intensity and unpleasantness. In contrast, for noxious cutaneous stimulation, ketamine reduced pain unpleasantness, but not perceived intensity. In addition, ketamine did not alter the perception of innocuous stimuli in either modality. Our results confirm the analgesic effects of low-dose ketamine, with minimal side effects, on acute visceral pain and indicate a similar but smaller effect on acute cutaneous pain. A decrease in the unpleasantness but not in the intensity of cutaneous pain may reflect the differential effect of NMDA-R antagonists for the two pain states observed in animal models.

Adolescent↗

PubMed2003

Balancing societal costs and users' quality of life--priority setting of interventions for the hard-of-hearing.

In this paper, the need for priority setting in rehabilitation, especially in audiology, and various approaches to providing information for priority setting are discussed. A set of outcome measures is proposed, and their applicability to vertical and horizontal prioritization are considered. Two types of measures are proposed: individual problems assessment, and utility analysis. Results from a European multicentre study and a Swedish study illustrate the performance of the measures in the areas of mobility, hearing, and speech communication. For rehabilitation in the hard-of-hearing, the two types of measures provide different kinds of information, illustrated by the results of simultaneous use of the instruments.

Activities of Daily Living↗

PubMed2002

Risk factors for rejection of synthetic suburethral slings for stress urinary incontinence: a case-control study.

OBJECTIVE: To identify variables associated with rejection of synthetic, suburethral slings used for female stress urinary incontinence. METHODS: Between 1991 and 1998, gynecologists at our department performed 428 operations for stress urinary incontinence by inserting expanded polytetrafluoroethylene or polyethylene suburethral slings. After suitable exclusions, 386 women followed for at least 24 months after surgery remained for analysis. Of the 386 women, 47 (12.2%) had graft rejection or symptoms associated with rejection within 24 months after surgery, which led to later removal. We compared cases and controls using logistic regression analyses with forward selection to identify independent risk factors and risk markers for rejection. RESULTS: The rejection rate declined sharply during the years 1993-1994 after introduction of routines that included preoperative prophylactic antibiotics active against anaerobes and repeated preoperative treatment of the vagina with chlorhexidine acetate. After adjusting for potentially confounding variables, surgery after 1993, the gynecologist performing the procedure, and adequate antibiotic prophylaxis remained significantly associated with a lower rejection rate. There was no significant association between rejection and sling material, age at surgery, year of surgery (in one year steps), or concomitant prolapse surgery. CONCLUSION: Rejection of suburethral slings might be associated with bacterial contamination of the graft, and the rate was decreased with prophylactic antibiotics a repeated and vaginal disinfection.

Adult↗

PubMed2002

Does sodium fluoride in bone cement affect implant fixation. Part II: evaluation of the effect of sodium fluoride additions to acrylic bone cement and the fixation of titanium implants in ovariectomized rabbits.

Bone integration of threaded implants made of cured polymethylmethacrylate containing sodium fluoride or commercially pure (c.p.) titanium were studied in normal and estrogen deficient New Zealand white rabbits. Nine had been ovariectomized through laparoscopy and nine served as controls. Four weeks after the ovariectomy two threaded implants made of cured bone cement with or without sodium fluoride addition were inserted in each tibia. One threaded commercially pure titanium implant was inserted in each patello-femoral joint flush to the cartilage. Six weeks after implant insertion measurement of the peak removal torque necessary to loosen the implants and light microscopical histomorphometrical investigations of tissue integration were performed. In the ovariectomized rabbits addition of sodium fluoride to the cement resulted in increased area of bone in the threads (p=0.04), but no corresponding effect could be noted in the controls. The removal torque was lower in the ovariectomized rabbits compared to the non-ovariectomized when comparing implant with sodium fluoride addition (p=0.02). The bone tissue response and the removal torque of the titanium implants were not influenced by ovariectomy in these rabbits.

Journal Article↗

PubMed2002

Cost-analyzes based on a prospective, randomized study comparing laparoscopic colposuspension with a tension-free vaginal tape procedure.

BACKGROUND: The aim of this study was to compare laparoscopic colposuspension with tension-free vaginal tape (TVT) in terms of costs to the county. METHODS: In a prospective, randomized study, we approached 270 consecutive women presenting for evaluation of stress urinary incontinence symptoms at one university hospital. Preoperatively, and at 1-year follow-up, the women underwent urodynamic evaluation, an ultra-short pad-test and completed a lower urinary tract symptoms questionnaire. We randomized 79 consenting, eligible women to either procedure; a 1-year follow-up examination was performed on 68/71 (96%) women that were available. The procedures were performed as described previously. Main outcome measures were all relevant costs for goods and services associated with the procedures. RESULTS: The baseline characteristics of the two groups were similar. The TVT procedure was performed significantly faster than the laparoscopic colposuspension, i.e. 44.9 +/- 14.2 min compared with 60.5 +/- 13.4 min (p < 0.0001). Even so, procedural costs were significantly lower for laparoscopic colposuspension than for TVT (euro 1273.4 compared with euro 1342.8 p < 0.001). At the 1-year follow-up visit, three women operated on with TVT and one operated on with laparoscopic colposuspension required re-operation for continuous stress urinary incontinence. One women operated on with TVT had her sling cut for bladder-emptying problems. Total costs, including re-operations were euro 1462.6 for a TVT procedure andeuro; 1314.5 for a laparoscopic colposuspension. CONCLUSION: In our hands, the laparoscopic colposuspension was less expensive to the county than the TVT procedure.

Adult↗

PubMed2002

Cannabis for chronic pain: case series and implications for clinicians.

BACKGROUND: Chronic pain is one of the most common reasons for therapeutic cannabis use. OBJECTIVES: To describe therapeutic cannabis use among patients with chronic pain. METHODS: Patients with chronic pain who voluntarily indicated that they used cannabis therapeutically completed a questionnaire about the type of cannabis used, the mode of administration, the amount used and the frequency of use, and their perception of the effectiveness of cannabis on a set of pain-associated symptoms and side effects. The study was approved by the McGill University Health Centre Research Ethics Board. RESULTS: Fifteen patients (10 male) were interviewed (median age 49.5 years, range 24 to 68 years). All patients smoked herbal cannabis for therapeutic reasons (median duration of use six years, range two weeks to 37 years). Seven patients only smoked at night-time (median dose eight puffs, range two to eight puffs), and eight patients used cannabis mainly during the day (median dose three puffs, range two to eight puffs); the median frequency of use was four times per day (range one to 16 times per day). Twelve patients reported improvement in pain and mood, while 11 reported improvement in sleep. Eight patients reported a 'high'; six denied a 'high'. Tolerance to cannabis was not reported. CONCLUSIONS: The results of this self-selected case series must be interpreted with caution. Small doses of smoked cannabis may improve pain, mood and sleep in some patients with chronic pain. Clinical trials are warranted to test these effects. Further prospective studies should examine the patterns and prevalence of cannabis use among chronic pain populations.

Adult↗

PubMed1995

Beneficial effects of ketamine in a chronic pain state with allodynia, possibly due to central sensitization.

Allodynia is a well-known component of neuropathic pain resulting from injury to the nervous system. Clinical pain states with allodynia in connection with longstanding superficial wounds have, however, not been reported in the literature. In this case a chronic pain state developed in a previously healthy 17-year-old girl in and around a persistently suppurating appendectomy wound. There was no spontaneous pain but pronounced allodynia in the wound and in the surrounding skin. Quantitative thermal tests showed abnormal thresholds for several sensory modalities confirming abnormal processing of sensory input from the involved area. The pattern of sensory abnormalities evaluated with thermal testing changed transiently and the allodynia diminished during a phentolamine block. Since the pain responded poorly to opioids and ketamine has been reported to reduce allodynia, it was administered in a sub-dissociative bolus dose during wound dressing. The wound was essentially unchanged after treatment for 3 months but the allodynia and sensory aberrations had decreased significantly. We interpret these results as a de-sensitizing effect in the long term of repeated NMDA-receptor blockade by ketamine in a chronic pain state, with indications of central sensitization, partially maintained by sympathetic activity.

Adolescent↗