In biomedical research, researchers frequently use statistical procedures such as the t-test, standard analysis of variance (ANOVA), or the repeated measures ANOVA to compare means between the groups of interest. There are frequently some misuses in applying these procedures since the conditions of the experiments or statistical assumptions necessary to apply these procedures are not fully taken into consideration. In this paper, we demonstrate the correct use of repeated measures ANOVA to prevent or minimize ethical or scientific problems due to its misuse. We also describe the appropriate use of multiple comparison tests for follow-up analysis in repeated measures ANOVA. Finally, we demonstrate the use of repeated measures ANOVA by using real data and the statistical software package SPSS (SPSS Inc., USA).
*Analysis of Variance ; Chemistry, Clinical ; *Models, Statistical ; Multivariate Analysis ; Reproducibility of Results

PURPOSE: Bax promotes apoptosis and is up-regulated by p53, which is not required for androgen ablation-induced apoptosis of the prostatic cells. We investigated the change of lax during the involution of the rat prostate following castration. MATERIALS AND METHOD: Adult male rats were castrated and the ventral prostatic glands were removed daily for a week following castration. Western blot and immunohistochemical analysis of lax protein were performed using anti-bax rabbit polyclonal IgG. RESULTS: The prostatic weight decreased and the apoptotic cells began to appear 2 days following castration. Western blot analysis showed that lax was absent in the control prostate but began to increase 4 days following castration. Immunohistochemical analysis showed that bars was confined to the cells which had morphological characteristics of the late stage of programmed cell death. CONCLUSIONS: Present results suggest that bars might be involved in the late stage of castration-induced apoptosis of the rat prostatic cells.
Adult ; Animals ; Apoptosis ; Blotting, Western ; Castration* ; Cell Death ; Humans ; Immunoglobulin G ; Male ; Prostate* ; Rats*

Purpose: We evaluated the variables that may predict the final Gleason score of a radical prostatectomy in the patients showing more than two different Gleason scores in their positive core biopsy specimens. Materials and Methods: We reviewed the pathological data of patients diagnosed with prostate cancer using extended (12 site or more) needle biopsies who underwent a radical retropubic prostatectomy. A total of 73 patients showed more than two different Gleason scores in their biopsy specimen. The following parameters were assessed: highest Gleason score in the biopsy specimen, the Gleason score of the highest tumor percentage in the core and the highest tumor ratio score (Gleason score of highest total tumor length of same Gleason score/total core length of same Gleason score). Concordance of the Gleason scores between the biopsy specimen and prostatectomy was also examined. Results: The highest tumor ratio score showed the highest (64.4%) concordance rate. The concordance rates of the Gleason scores of the highest tumor percentage in the core and the largest linear cancer length were 59 and 58%, respectively. The concordance rate of the highest Gleason score in the biopsy specimens was only 47%. When stratified by grade: well differentiated (Gleason score=6), moderate (7) and poorly differentiated (8-10), the grade concordance rate of the highest tumor ratio score was 73%. The grade concordance rates of the highest and largest linear cancer length Gleason scores were 64.4 and 64.3%, respectively. Conclusions: If a biopsy specimen shows more than two different Gleason scores in positive cores, the highest tumor ratio score may be the most useful variable for predicting the final Gleason score from radical prostatectomy specimens.
Biopsy* ; Biopsy, Needle ; Humans ; Neoplasm Grading* ; Prostatectomy* ; Prostatic Neoplasms

PURPOSE: We evaluated the effect of the serum prostate specific antigen (PSA) levels in the range 4.1 to 10.0ng/ml on the pathologic characteristics after a radical prostatectomy. MATERIALS AND METHODS: Between July 1997 and June 2004, 117 men (64 years: 44-75) with an intermittent PSA level underwent radical retropubic prostatectomy. The patients were divided into 6 groups according to the PSA level (4.1-5.0, 5.0-6.1, 6.1-7.0. 7.1-8.0, 8.1-9.0 and 9.1-10.0ng/ml), and compared the age, prostate volume, Gleason score of biopsy specimen and pathologic stage, grade and margin status of prostatectomy specimen between the 6 groups. RESULTS: The mean age, prostate volume and Gleason score of the biopsy were not significantly different between the 6 groups. The pathologic stage and margin status also were not significantly different between the 6 groups. The mean Gleason score was higher in the high PSA group, but this was not statistically significant. When divided into two groups (group with PSA 4.1-7.0 and 7.1-10.0ng/ml), the pathologic stage and margin status were no different. However, the mean Gleason score and the rate of high grade (Gleason score 8-10) prostate cancer were higher in the high PSA group. The mean high grade prostate cancer rates were 22 and 7% in the PSA 7.1-10.0 and 4.1-7.0ng/ml groups, respectively (p=0.019). CONCLUSIONS: A PSA level above 7.0ng/ml in the intermediate group influenced the pathologic grade of the radical prostatectomy. This result suggests that prostate cancer with a PSA level higher than 7.0ng/ml may have a more aggressive feature.
Biopsy ; Humans ; Male ; Neoplasm Grading ; Prostate ; Prostate-Specific Antigen ; Prostatectomy* ; Prostatic Neoplasms

Purpose: We evaluated the improvement in the rate of prostate cancer detection with the use of an extensive 12-site biopsy protocol in patients with only an elevated level of serum prostate-specific antigen (PSA). Materials and Methods: A total of 109 men with elevated PSA levels between 3 and 20ng/ml, but with no abnormal finding on digital rectal and transrectal ultrasound examinations, received transrectal ultrasound- guided prostate biopsies, which were performed at 12 sites, including the routine sextant and 6 far lateral regions (lateral apex, mid-lobe and base). The improvement in the detection rate was assessed according to the PSA level and prostate volume. Results: The mean age and PSA level of the patients were 63.5 8.6 years and 7.0 3.7ng/ml, respectively. Twenty-eight (25.7%) out of 109 men were diagnosed with prostate cancer. A traditional sextant biopsy detected 19 (67.9%) of the 28 prostate cancer patients, while 9 (32.1%) cancers were detected in the lateral region only. Overall, this extensive protocol resulted in a significant improvement, 8.3% (17.4 to 25.7%), in the detection rate (p=0.032). The improvement in men with a PSA of 10 ng/ml or less was 8.1% (14.0% to 22.1%, p=0.007) and in those with a PSA greater than 10 ng/ml the improvement was 8.7% (30.4% to 39.1%, p=0.162). The improvement in men with a prostate volume of 50cc or less was 8.0% (22.3% to 30.3%, p=0.083) and in those with a prostate volume greater than 50cc this was 9.1% (6.1% to 15.2%, p=0.043). Conclusions: The twelve-site biopsy protocol is a more efficient method in men with a PSA and prostate volume of 10ng/ml or less and greater than 50cc, respectively, compared to the sextant protocol.
Biopsy* ; Humans ; Male ; Prostate ; Prostate-Specific Antigen* ; Prostatic Neoplasms ; Ultrasonography