Biomedical subjects
Pekka Hellström
Publications and source records attributed to Pekka Hellström.
Mechanisms of pain in chronic pelvic pain syndrome: influence of prostatic inflammation.
Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), is of considerable interest in clinical urology. During the past decade, several new approaches have been made to discover its aetiology and pathophysiological mechanisms and to develop treatment modalities. The aetiology of CPPS has remained unresolved. Bacterial, chemical, urodynamic and immunological aetiologies have been suggested, but none of these has been conclusively proven. The histopathological changes in CP and CPPS are relatively well known, but the pathophysiological changes that lead to chronic inflammation and prolonged symptoms are still poorly understood. This review proposes an additional approach to the pathophysiology of CPPS. The concept of prostate tissue pressure is introduced as an objectively measurable parameter in evaluating the inflammatory process in CPPS. Chronic pain due to neurogenic inflammation and altered mast cell function is also discussed.
Effect of diagnostic hydrodistension and four intravesical hyaluronic acid instillations on bladder ICAM-1 intensity and association of ICAM-1 intensity with clinical response in patients with interstitial cystitis.
OBJECTIVES: To study the clinical effect of diagnostic overdistension plus hyaluronic acid (HA) instillations in interstitial cystitis and the association of the clinical response with the intensity of intercellular adhesion molecule (ICAM)-1 expression. HA is an important component in the urothelium. It inhibits adherence of immune complexes to polymorphonuclear cells, leukocyte migration, and aggregation. HA binds to lymphocytes and endothelial cells expressing ICAM-1. METHODS: Eleven patients with interstitial cystitis who fulfilled the diagnostic criteria of the National Institutes of Health were selected for the trial. The bladder was distended for 1 minute with a pressure of 80 cm H2O and biopsies were taken from the petechial areas. The patients were treated with four weekly intravesical HA instillations (40 mg/50 mL NaCl solution). Biopsies were repeated 2 weeks after the instillations. The ICAM-1 intensity was blindly determined in the lymphocytes and endothelial cells of the vessels from the histologic biopsies. A semiquantitative scoring index was used to measure the inflammatory effect of ICAM-1 receptors. RESULTS: In the long-term responders (2 women and 1 man) and short-term responders (5 women), the pretreatment ICAM-1 index was 3.7 (range 3 to 4); it was 1.8 (range 1.5 to 2) in the nonresponders. Two weeks after the final instillation, the index was 3.5 (range 3 to 4) in the long-term responders and 3.4 (range 3 to 4) in the short-term responders; in the nonresponders, it had increased to 2.8 (range 2.5 to 3.5). CONCLUSIONS: Increased ICAM-1 intensity was found in patients with interstitial cystitis; it was higher in those who responded to overdistension plus HA instillations. By blocking the ICAM-1 receptors, HA presumably alleviates the inflammatory processes, but repeated instillations are needed to maintain the response.
Factors explaining recurrence in patients undergoing chemoimmunotherapy regimens for frequently recurring superficial bladder carcinoma.
OBJECTIVES: To study the factors determining new recurrences in patients with frequently recurring superficial bladder tumors. METHODS: Of all 205 eligible patients, each received 5 weekly intravesical instillations of mitomycin C (MMC), with the first instillation given perioperatively. This was followed, according to randomization, by BCG instillations alone or by alternating instillations of interferon-alpha and BCG monthly for up to 1 year. Impact of 12 variables on time to first recurrence was retrospectively studied with the Cox multiple hazards regression and Kaplan-Meier analysis. RESULTS: Type of regimen was the most significant factor determining new recurrences, with preceding recurrence rate being the most important prognostic factor. Timing of the first MMC was the third significant predictor in the main multivariate analysis, with more than a two-fold relative risk for a new recurrence if the first MMC instillation was given later than on day 0. CONCLUSION: Preceding recurrence rate, most accurately reflects, in patients with frequently recurring tumors, the inherent risk for new recurrences. This risk can be considerably reduced by use of an effective chemoimmunotherapy regimen, and in addition, by inclusion of an early perioperative chemotherapy instillation in such a regimen.
The chronic prostatitis-chronic pelvic pain syndrome can be characterized by prostatic tissue pressure measurements.
PURPOSE: We performed a prospective study to confirm early results implying that intraprostatic tissue pressure is elevated in men with the chronic prostatitis-chronic pelvic pain syndrome. We planned to determine further whether this technique would detect a significant difference in inflammatory and noninflammatory categories IIIA and IIIB. MATERIALS AND METHODS: A total of 48 patients with the chronic prostatitis-chronic pelvic pain syndrome, including 18 with inflammatory category IIIA and 30 with noninflammatory category IIIB disease, and 12 asymptomatic controls completed a Finnish version of the National Institutes of Health-Chronic Prostatitis Symptom Index. In addition, culture and microscopy of lower urinary tract segmented specimens, serum prostate specific antigen determination, transrectal ultrasound, uroflowmetry and ultrasound post-void residual urine measurement were done. All patients and controls also underwent independent intraprostatic right and left lobe tissue pressure measurement using a standard intracompartmental tissue pressure monitor system. Pressure was measured via an intraprostatic needle placed percutaneously in the perineum at baseline, and 10, 60 and 120 seconds after standard saline injection. RESULTS: All patients with the chronic prostatitis-chronic pelvic pain syndrome had significantly higher pressure at all measurement points compared with controls (p <0.001). Mean intraprostatic tissue pressure was significantly higher (p <0.01) in category IIIA with greater than 10 leukocytes per high power field in prostate specific specimens compared with category IIIB with less than 10. CONCLUSIONS: Our study supports the suggestion that patients with the chronic prostatitis-chronic pelvic pain syndrome have significantly higher prostate tissue pressure than controls. Findings also validated the previous clinical assumption that there is a rationale for differentiating chronic prostatitis-chronic pelvic pain syndrome cases into inflammatory and noninflammatory categories.