Decreased elastin gene expression in noncompliant human bladder tissue: a competitive reverse transcriptase-polymerase chain reaction analysis

PURPOSE

In low capacity noncompliant fibrotic bladders, as seen in patients with myelomeningocele, elevated storage pressures ultimately can lead to renal damage. Earlier studies have described an increased deposition of extracellular matrix protein, especially type III collagen, in the detrusor muscle. We analyzed elastin gene expression and quantified elastin gene alteration in the obstructed bladder, correlating urodynamically measured compliance with elastin messenger ribonucleic acid (mRNA) concentration.

MATERIALS AND METHODS

Using a reverse transcriptase-polymerase chain reaction quantitative technique elastin mRNA can be reliably measured in 5 to 8 mg. samples of bladder tissue. We compared tissue samples from patients with urodynamically demonstrated noncompliant bladders (less than 10 cc/cm. water) to a control group with normal bladder compliance (greater than 20 cc/cm. water). Tissue samples were homogenized and sonicated, and complementary deoxyribonucleic acid (cDNA) was synthetized from mRNA using reverse transcriptase. Wild type and mutant elastin cDNA were synthetized, and target elastin cDNA with unknown concentration was competitively co-amplified with known serial dilutions of the mutant template (competitive polymerase chain reaction). Computerized densitometry allowing cDNA concentration measurement was performed and competitive reverse transcriptase-polymerase chain reaction was repeated at least twice for every sample.

RESULTS

Elastin mRNA concentration ranged from 27.6 to 63.2 attomole per mg. in noncompliant bladders compared to 62 to 190 attomole per mg. in controls. The variation within the same sample was less than 10%. There was a statistically significant difference between mean plus or minus standard deviation elastin cDNA concentration in noncompliant bladders (37.48 attomole per mg. +/- 12.06) and controls (119.63+/-41.01 attomole per mg.).

CONCLUSIONS

A significant decrease in elastin mRNA matches the decreased deposition of elastic fibers noted in previous immunohistochemical studies. Our data suggest that this decrease is mainly due to a transcriptional down regulation of the elastin gene in noncompliant bladders.

Tolerability of high energy transurethral microwave thermotherapy with topical urethral anesthesia: results of a prospective, randomized, single-blinded clinical trial

PURPOSE

We determine the tolerability of high energy transurethral microwave thermotherapy with topical urethral anesthesia alone without supplementary systemic sedoanalgesia.

MATERIALS AND METHODS

A total of 45 patients with symptomatic benign prostatic hyperplasia were randomized to high energy transurethral microwave thermotherapy using either topical urethral anesthesia alone (topical anesthesia group) or topical anesthesia with adjunctive intravenous sedoanalgesia (sedoanalgesia group). Pain was evaluated sequentially by means of a 0 to 10 visual analog scale score. Posttreatment followup included determinations of International Prostate Symptom Score, peak flow rate, post-void residual urine, and quality of life score at 6 and 12 weeks.

RESULTS

Upon commencement of microwave treatment mean visual analog scale score was 1.3 (95% confidence interval [CI], 1.0 to 1.7) in the sedoanalgesia group and 1.4 (95% CI, 1.0 to 1.9) in the topical anesthesia group. During therapy visual analog scale score increased to a peak at 30 minutes of 2.0 (95% CI, 1.6 to 2.4) and 2.2 (95% CI, 1.7 to 2.6) in the sedoanalgesia and topical anesthesia groups, respectively. Thereafter, visual analog scale score continuously declined, falling to 0.1 (95% CI, 0.0 to 0.2) and 0.2 (95% CI, 0.0 to 0.3) in the 2 respective groups by 1 hour following conclusion of the treatment period. There was no statistically significant difference between the groups in the treatment profile of visual analog scale scores (p = 0.701). Significant posttreatment improvements were demonstrated in International Prostate Symptom Score, peak flow rate, post-void residual urine and quality of life scores but there were no significant differences between the groups in the magnitude of improvement in these outcome measures.

CONCLUSIONS

High energy transurethral microwave thermotherapy is well tolerated by patients under topical anesthesia alone and, therefore, can be administered in the outpatient setting without potent medications that necessitate intensive patient monitoring, pose risks for side effects and add to treatment costs.

Prostate specific antigen density of the transition zone for early detection of prostate cancer

PURPOSE

We compare the ability of several prostate specific antigen (PSA) parameters, including PSA density of the whole prostate and of the transition zone, percent free PSA and PSA velocity, to enhance the specificity for prostate cancer detection and to reduce unnecessary biopsies in men with serum PSA levels of 4 to 10.0 ng./ml.

MATERIALS AND METHODS

This prospective study included 559 consecutive men referred for early prostate detection or lower urinary tract symptoms who had a serum PSA of 4.0 to 10.0 ng./ml. All men underwent prostatic ultrasonography and sextant biopsy with 2 additional transition zone biopsies. Specific biopsies of abnormal findings on digital rectal examination were also performed. In all cases if first biopsies were negative an additional set of biopsies was performed within 6 weeks. The ability of PSA density, PSA transition zone, PSA velocity and percent free PSA to improve the power of PSA in the detection of prostate cancer was evaluated with univariate and multivariate analyses as well as receiver operating characteristics (ROC) curves.

RESULTS

Of 559 patients 342 had histologically confirmed benign prostatic hyperplasia and 217 had prostate cancer. Mean serum PSA, PSA velocity, PSA density and PSA transition zone were statistically higher (p <0.018, p <0.037, p <0.0001 and p <0.0001, respectively) and percent free PSA was statistically lower (p <0.0001) in patients with prostate cancer than in those with benign disease. Multivariate analysis and ROC curves showed that PSA transition zone and percent free PSA were the most powerful and highly significant predictors of prostate cancer. Areas under the ROC curve for PSA transition zone and percent free PSA were 0.827 and 0.778, respectively (p=0.01 McNemar test). Combination of free-to-total PSA with PSA transition zone significantly increased the area under the ROC curve compared to PSA transition zone alone (p=0.020). With a 95% sensitivity for prostate cancer detection a PSA transition zone cutoff of 0.25 ng./ml./cc would result in the lowest number of unnecessary biopsies (47% PSA transition zone specificity) compared to all other PSA parameters. However, total prostate volume (greater than 30 cc in 422 men or less than 30 cc in 137) was an important factor in predicting the statistical performance of PSA transition zone. In fact, PSA transition zone did not outperform free percent PSA in sensitivity and specificity when the entire prostate gland volume was less than 30 cc (p=0.094 McNemar test).

CONCLUSIONS

PSA density of the transition zone enhances the specificity of serum PSA for prostate cancer detection in referred patients with a serum PSA of 4.0 to 10.0 ng./ml. compared to other PSA parameters currently available. While PSA transition zone was more effective in prostates greater than 30 cc and percent free PSA was more effective in prostates less than 30 cc, the combination of percent free PSA with PSA transition zone further increased prostate cancer prediction.

Transperineal radiofrequency interstitial tumor ablation (RITA) of the prostate

The purpose of this study was to investigate the safety and feasibility of radiofrequency interstitial tumor ablation (RITA) in localized prostate cancer (PCa) and to assess the predictability of the lesions obtained. In 10 patients with localized PCa (mean age 70.4 years), a total of 21 marker lesions were induced under general (n = 3), spinal (n = 4), or local anesthesia only (n = 3). Radiofrequency energy was delivered transperineally under transrectal ultrasound (TRUS) guidance. Radical prostatectomy was performed in all patients 1-7 days after RITA. The findings of intraoperative TRUS and histologic examination of the specimen were correlated. Lesions 2 x 2 x 2 cm were targeted. Postoperatively, patients were catheterized for an average of 1.8 days (range 1-3). Average lesion diameters defined by coagulative necrosis at histologic examination were 2.20 +/- 0.23 x 2.10 +/- 0.31 x 2.38 +/- 0.14 cm (average volume 5.86 +/- 1.63 cm3). Lesions were well defined and did not extend beyond the prostatic capsule. No complications (e.g., rectal wall injury) were noted. RITA-induced lesions were safe, feasible, technically simple, and resulted in lesions well predictable in size and location. On histologic examination, well-defined areas of coagulative necrosis were documented. No damage to the periprostatic tissue was noted. The procedure can be performed with spinal or local anesthesia only.

Transperineal radiofrequency interstitial tumor ablation of the prostate: correlation of magnetic resonance imaging with histopathologic examination

OBJECTIVES

Radiofrequency (RF) energy has recently been employed to destroy human tissue in vivo. The purpose of this study was to investigate the safety of this approach in localized carcinoma of the prostate (CaP) and specifically, the predictability of lesions obtained with radiofrequency interstitial tumor ablation (RITA).

METHODS

Using RITA, a total of 21 lesions were induced in 10 patients with localized CaP (mean age 70.4 years). RF was delivered transperineally under transrectal ultrasound (TRUS) guidance. All patients underwent endorectal magnetic resonance imaging (MRI) before and after treatment. Radical prostatectomy was performed in all patients 1 to 7 days after RITA. Three of the patients were treated with local anesthesia only. The predictability of the thermal lesion was assessed by correlating the findings of intraoperative TRUS, pre- and post-RITA endorectal MRI, and the histologic examination of the specimen.

RESULTS

Postoperatively, patients were catheterized for an average of 1.8 days (1 to 3 days). Lesions of 2 x 2 x 2 cm were targeted. Average lesion diameters obtained on MRI were 2.08 +/- 0.23 x 2.09 +/- 0.36 x 2.28 +/- 0.21 cm. Average lesion diameters defined by coagulative necrosis at histologic examination were 2.20 +/- 0.23 x 2.10 +/- 0.31 x 2.38 +/- 0.14 cm. There were no statistically significant differences (P = 0.377) between average lesion volume on MRI (5.37 +/- 1.83 cm3) and average lesion volume at histology (5.86 +/- 1.63 cm3). No complications or adverse events were noted.

CONCLUSIONS

In this Phase I study, RITA was shown to be safe and feasible, and to result in lesions that were predictable in size and location. MRI accurately visualized and verified the area of coagulative necrosis as documented at histology. The procedure is technically simple and can even be performed under local anesthesia.