Working length determination in general dental practice: a randomised controlled trial.

OBJECTIVE: To evaluate the ability of apex locators as a tool in determining working length in comparison to traditional working length radiographs in general dental practice. DESIGN: Randomised controlled clinical trial. SETTING: General dental practices in the North West of England.Subjects Adults requiring root canal treatment of at least one tooth with minimal or moderate difficulty. INTERVENTION: Root canal treatment was carried out with the working length determined by apex locator in the treatment group (AL), and periapical radiograph in the control group (PA). OUTCOME MEASURE: The acceptability of the master cone gutta percha measured from a radiograph before obturation was used as the primary outcome. RESULTS: Twenty-one of 23 fillings in the AL group were judged as acceptable, compared to 17 of 23 fillings in the PA group. This difference was not statistically significant. CONCLUSION: In general dental practice, no significant difference was found in working length determined using apex locator combined with a master cone GP radiograph or using the conventional method. There is a need for larger trials to investigate these methods further.

Metallothionein expression in prostatic carcinoma: correlation with Gleason grade, pathologic stage, DNA content and serum level of prostate-specific antigen.

OBJECTIVE: To determine the expression of metallothionein (MT) in prostatic carcinoma by immunohistochemical staining. Several lines of evidence have indicated that MT may play a role in carcinogenesis and in drug resistance of tumours. DESIGN: Retrospective pathologic study. INTERVENTIONS: Formalin-fixed, paraffin-embedded archival tissues from 39 radical prostatectomies were analysed. All tumour foci were stained by ABC technique using a primary polyclonal rabbit antibody against rat liver MT. The staining intensity for MT was graded on a scale of 0 to 2+, and the histologic grading was done by the scheme of Gleason. OUTCOME MEASURES: Correlation of MT expression with Gleason grade, preoperative serum prostate-specific antigen (PSA) levels, pathologic stage and DNA content, including S-phase fraction (SPF) and proliferative index (PI). RESULTS: Most of the epithelium of normal prostate tissue had patchy, intense MT staining. All the grade II tumours foci showed intense (2+) staining for MT, while all grade IV and V foci were persistently negative. The grade III tumours foci were heterogeneous. The MT-positive foci showed both nuclear and cytoplasmic staining of variable extent. There were 9, 15, 13 and 2 tumours with pathologic stage B, C1, C2 and D1, respectively. The serum PSA levels ranged from 1 to 16 ng/mL. No apparent correlation existed between the MT staining pattern and the pathologic stage or preoperative PSA level. Thirty-four of the tumours were diploid and 5 were tetraploid. There were significantly higher SPF and PI mean values in the MT-stained tumour cells (p < 0.05), suggesting that MT preferentially stains an epithelial subpopulation, possibly the proliferating cell compartment. CONCLUSION: The positive correlation of MT expression with Gleason grade in prostatic adenocarcinoma suggests a possible role for MT in oncogenesis in prostate cancer.

DNA cytometric proliferative index predicting organ confinement in clinical stage-B prostate cancer.

PURPOSE: To assess nuclear activity by DNA flow cytometry (FCM), Gleason score and serum prostate-specific antigen (PSA) levels in predicting extracapsular tumour involvement in patients with prostate cancer. DESIGN: Retrospective pathologic study. PATIENTS: Forty patients with clinical stage-B prostate cancer who underwent radical prostatectomy. INTERVENTIONS: The relationship between the pathologic state and each of the proliferative index (PI). Gleason score and PSA level was analysed retrospectively with the use of archival specimens. Preoperative serum PSA levels, were measured by the Hybritech assay. Gleason score was determined by 2 of the authors. Tumours were classified as stage B (confined to prostate), C1 (focal capsular penetration) or C2 (involvement of seminal vesicles or capsular perforation). FCM PI measurements were performed on deparaffinized tumour specimens. RESULTS: All 40 specimens were diploid. There were 9 pathologic stage-B, 16 stage-C1 and 15 stage-C2 tumours. The serum PSA level was 20 ng/mL or less for all patients except 2, for whom the levels were 27.8 ng/mL and 45.9 ng/mL, respectively. A Gleason score lower than 7 had a 76.0% sensitivity and 53.5% specificity in predicting organ confinement. In contrast, a PI of 21 or lower had a 84.0% sensitivity and a 73.0% specificity in predicting organ confinement, with a positive predictive value of 84.0%. Of the 17 tumours with both "favourable" features (Gleason score lower than 7 and PI of 21 or lower), only 1 (5.9%) had extracapsular involvement (stage C2). Of the 6 tumours with both "unfavourable" features (Gleason score higher than 7 and PI of 21 or higher) 5 of 6 were stage C2 and 1 was stage C1. CONCLUSION: The single most consistent predictor of organ confinement was PI alone.

Receiver operating characteristic (ROC) curve analysis of transrectal ultrasonographic prostate cancer detection.

PURPOSE: To provide an overview of receiver operating characteristics (ROC) curve theory and create an ROC curve describing transrectal ultrasound (TRUS) detection of prostate cancer (PCa). METHODS: One hundred thirty-two patients with either an abnormal digital rectal exam (DRE) or a prostate-specific antigen (PSA) above 4 ng/ml or both underwent TRUS and biopsy of the peripheral zone (PZ) of each quadrant. ROC software was used to create an ROC curve. RESULTS: One hundred seventy-nine of 528 quadrants (34%) harbored PCa. The performance of TRUS in detection of PCa as defined by the area below the ROC is 0,809. CONCLUSIONS: Future investigators are encouraged to employ ROC analysis of TRUS to permit more meaningful comparisons of performance.