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The aim of this study was to determine the variability in total testosterone (TT) levels in healthy, non-obese ageing men with symptoms of androgen deficiency. Men aged ≥55 years were recruited from the community. Morning TT levels were measured on four occasions in a 12-month period. In all, 96 men aged 62.7 ± 6.8 years were studied. Geometric mean values (95% confidence interval) of TT levels for the cohort at each time point were 14.5 (13.4-15.7), 14.6 (13.5-15.8), 15.5 (14.4-16.8) and 15.0 (13.9-16.2) nmol/L. The maximum intra-individual difference in TT between the four samples was 4.1 nmol/L (interquartile range: 2.9-6.4). Using the average of two baseline TT values reduces the maximum difference to 2.3 nmol/L (1.0-3.8). Only 1 of 25 men with a documented TT <10 nmol/L at baseline had TT levels <10 nmol/L at all subsequent time points. A single TT level is a reliable predictor of repeat measures taken within a 12-month period for a cohort of healthy ageing men with symptoms of androgen deficiency. However, given that the diagnostic criteria for androgen deficiency are, in part, predicated upon serum TT, there is sufficient intra-subject variability to warrant repeat sampling to confirm an initial low TT level. Using an average of two baseline TT values reduces this variability., (© 2010 The Authors. International Journal of Andrology © 2011 European Academy of Andrology.)

The relative distribution of sensitizer drugs in the prostate and its contiguous organs is of importance in the treatment of localized prostatic cancer with photodynamic therapy. Using the primate model, whose prostate is both morphologically and physiologically homologous with its human counterpart, the distribution of hematoporphyrin derivative (HpD) amongst organs of urological interest was determined. Hematoporphyrin derivative levels were comparatively low in both caudal and cranial prostatic lobes (0.93-1.77 micrograms/g) and were similar to those in rectum, urethra and the skin. The reticuloendothelial organs, liver, spleen and also the kidney accumulated the highest quantities of porphyrin (4.76-9.8 micrograms/g, liver > spleen > kidney). Despite a high avidity of prostatic tissue for zinc, a zinc-metalloporphyrin (Zn-HpD) did not concentrate selectively in the prostate. The results are of clinical value in view of the homology between the primate and the human.

3-aminotriazole (3AT) is known to reduce catalase levels in ocular tissues when given intravenously or orally. Rabbits were given either 4 ml/kg of a 3M solution of 3AT intravenously or a 2% solution as drinking fluid. Intravenous 3AT administration was followed at 4 hrs by an intracameral injection of hydrogen peroxide (H2O2) to give an aqueous humor concentration of 3.2 mM in young (4-6 weeks of age) and a 3.3 mM in adult (6 months of age) rabbits. Tissues were taken for microscopy at either 6 or 24 hours after intracameral H2O2. Neither oral nor intravenous 3AT alone in adult rabbits, or intravenous 3AT in young rabbits, had any effect on either iris, ciliary process, or corneal endothelial morphology. After oral 3AT in adult rabbits, H2O2 caused highly edematous ciliary processes with dilated vessels; corneal endothelial cells were swollen. Previous studies in adult and young rabbits have shown that intracameral H2O2 alone caused few morphological changes in young, but marked changes in the adult that correlated with the 35 to 50% lower catalase levels found in iris and corneal endothelium, respectively, in adult ocular tissues. Young rabbits pre-treated with intravenous 3AT, when examined at 6 and 24 hours after intracameral H2O2, showed swollen ciliary processes, vessel dilation, alteration of the pigment epithelium and corneal endothelial damage. In non 3AT-treated young rabbits, H2O2 caused only minor morphological changes. In adult animals at 6 and 24 hours after intracameral H2O2 the ciliary processes were edematous in the absence of 3AT; after intravenous 3AT and intracameral H2O2 the changes were even more marked, with very severe swelling of ciliary processes and corneal endothelial damage. It is apparent that the decrease in catalase caused by 3AT allows H2O2 to induce damage even in young animals where it usually does not induce morphological changes. In adult animals, the effects of H2O2 are enhanced in the presence of 3AT.

Although decline in sexual function is a common reason for ageing men to seek advice regarding testosterone therapy, placebo-controlled trial data have been unable to show a consistent, beneficial role for testosterone. The objective of this study was to determine the effect of testosterone therapy on sexual function in non-obese ageing men with symptoms of androgen deficiency and low–normal serum testosterone levels. A total of 60 men aged 55 years or older in good general health with total testosterone (TT) levels <15 nM, and with symptoms suggestive of androgen deficiency, were randomized in a double-blinded protocol to transdermal testosterone patches or placebo for 12 months. Sexual function was assessed using the International Index of Erectile Function at weeks 0, 26 and 52. In men receiving testosterone TT levels increased by 30% (P=0.01) and luteinizing hormone decreased by 50% (P<0.001). Relative to placebo, testosterone therapy improved sexual desire (P=0.04); however other parameters of sexual function including erectile function were unaffected by the treatment. Ageing men in good general health and with symptoms of androgen deficiency and low–normal serum testosterone levels receiving 12 months of transdermal testosterone therapy experienced, relative to placebo, improved sexual desire but no effect on other parameters of sexual function.International Journal of Impotence Research (2008) 20, 396–401; doi:10.1038/ijir.2008.22; published online 5 June 2008 [ABSTRACT FROM AUTHOR]