Purpose. Prostate cancer that recurs during androgen deprivation therapy is referred to as androgen-independent. High levels of expression of androgen receptor and androgen receptor-regulated genes in recurrent prostate cancer suggest a role for androgen receptor and its ligands in prostate cancer recurrence.Experimental Design. Recurrent prostate cancer specimens from 22 men whose prostate cancer recurred locally during androgen deprivation therapy and benign prostate specimens from 48 men who had received no prior treatment were studied. Androgen receptor expression was measured using monoclonal antibody and automated digital video image analysis. Tissue androgens were measured using radioimmunoassay.Results. Epithelial nuclei androgen receptor immunostaining in recurrent prostate cancer (mean optical density, 0.284 ؎ SD 0.115 and percentage positive nuclei, 83.7 ؎ 11.6) was similar to benign prostate (mean optical density, 0.315 ؎ 0.044 and percentage positive nuclei, 77.3 ؎ 13.0). Tissue levels of testosterone were similar in recurrent prostate cancer (2.78 ؎ 2.34 pmol/g tissue) and benign prostate (3.26 ؎ 2.66 pmol/g tissue). Tissue levels of dihydrotestosterone, dehydroepiandrosterone, and androstenedione were lower (Wilcoxon, P ‫؍‬ 0.0000068, 0.00093, and 0.0089, respectively) in recurrent prostate cancer than in benign prostate, and mean dihydrotestosterone levels, although reduced, remained 1.45 nM. Androgen receptor activation in recurrent prostate cancer was suggested by the androgenregulated gene product, prostate-specific antigen, at 8.80 ؎ 10.80 nmol/g tissue.Conclusions. Testosterone and dihydrotestosterone occur in recurrent prostate cancer tissue at levels sufficient to activate androgen receptor. Novel therapies for recurrent prostate cancer should target androgen receptor directly and prevent the formation of androgens within prostate cancer tissue.

Heart rate variability (HRV) analysis is commonly used as a quantitative marker depicting the activity of autonomous nervous system (ANS) that may be related to mental stress. For mobile applications, short term ECG measurement may be used for HRV analysis since the conventional five minute long recordings might be inadequately long. Short term analysis of HRV features has been investigated mostly in ECG data from normal and cardiac patients. Thus, short term HRV features may not have any relevance on the assessment of acute mental stress. In this study, we obtained ultra short term HRV features from 24 subjects during baseline stage and Stroop color word test. We validated these HRV features by showing significant differences in HRV features existed between the two stages. Our results indicated that ultra short term analysis of heart rate and RR intervals within 10 s, RMSSD and PNN50 within 30 s, HF within 40 s, LF/HF, normalized LF, and normalized HF within 50 s could be reliably performed for monitoring mental stress in mobile settings.

AR protein expression was 22% higher in the benign prostate and 81% higher in the CaP of black African compared with white men. CaP may occur at a younger age and progress more rapidly in black than in white men due to racial differences in androgenic stimulation of the prostate.

AR amplification in recurrent prostate cancer results in higher levels of AR protein expression but does not affect survival.

Androgen receptor expression was analyzed in the CWR22 human prostate cancer xenograft model to better understand its role in prostate cancer recurrence after castration. In androgen-dependent tumors, 98.5% of tumor cell nuclei expressed androgen receptor with a mean optical density of 0.26 +/- 0.01. On day 2 after castration androgen deprivation decreased immunostained cells to 2% that stained weakly (mean optical density, 0.16 +/- 0.08). Cellular proliferation measured using Ki-67 revealed <1% immunostained cells on day 6. Androgen receptor immunostained cells increased to 63% on day 6 and 84% on day 32 although immunostaining remained weak. Cellular proliferation was undetectable beyond day 6 after castration until multiple foci of 5 to 20 proliferating cells became apparent on day 120. These foci expressed increased levels of prostate-specific antigen, an androgen receptor-regulated gene product. In tumors recurrent 150 days after castration androgen receptor-immunostaining intensity was similar to CWR22 tumors from intact mice although the percentage of cells immunostained was more variable. The appearance of proliferating tumor cells that expressed androgen receptor and prostate-specific antigen 120 days after castration suggests that these cells represent the origin of recurrent tumors.