Differences in the gland compartment volumes of prostate tissue having distinct diffusivities, rather than changes in the conventionally cited "cellularity" metrics, are likely to be the major contributor to clinically observed variations of ADC in prostate tissue.

No abstract

Mortality from prostate cancer is associated with progression of tumors to androgen-independent growth and metastasis. Eicosanoid products of both the cyclooxygenase (COX) and lipoxygenase (LOX) pathways are important mediators of the proliferation of prostate cancer cells in culture and regulate tumor vascularization and metastasis in animal models. Pharmacologic agents that block either COX or LOX products effectively reduce the size of prostate cancer xenografts. Phospholipase A 2 (PLA 2 ) enzymes regulate the provision of arachidonic acid to both COX-and LOX-derived eicosanoids, and a secreted form of the enzyme (sPLA 2 -IIA) is elevated in prostate cancer tissues. Here, we show by immunohistochemistry, in patients receiving androgen ablation therapy, that sPLA 2 -IIA remains elevated in remaining cancer cells relative to benign glands after treatment. Furthermore, sPLA 2 -IIA expression seen in benign glands is substantially decreased after androgen depletion, whereas cytosolic PLA 2 -␣ (cPLA 2 -␣) levels are unchanged. sPLA 2 -IIA mRNA expression is detectable and inducible by androgen (0.01-10 nmol

No abstract

No abstract

The considerable experience of the University of Miami in treating TCC is reviewed in the first article in this section. The authors found that the incidence of upper tract tumour after radical cystectomy for TCC is low, but that patients with prostatic urethral involvement at cystectomy have a greater risk of developing upper tract tumours. A questionnaire‐based study in the UK attempted to assess how upper tract surveillance is carried out by British urologists in patients with urinary tract TCC. They found a wide variation in practice, which presumably is similar to that also found in other parts of the world. They recommend a follow‐up strategy and suggest that this surveillance should continue for at least 15 years. There is an evaluation of the long‐term results of salvage cystectomy after interstitial radiotherapy and external beam radiotherapy for TCC reported from Amsterdam. They found that salvage cystectomy gives acceptable morbidity and for any type of urinary diversion. OBJECTIVE To review the incidence, pattern and outcome of upper tract transitional cell carcinoma (TCC) after radical cystectomy for carcinoma of the bladder, and identify risk factors for its development. PATIENTS AND METHODS The records of 235 consecutive patients who had a radical cystectomy and urinary diversion for TCC at the authors’ institution by one surgeon between January 1992 and August 2003 were retrospectively reviewed. RESULTS Five (2%) of 235 patients developed an upper tract urothelial tumour. The mean follow‐up for all patients was 42 months, and was 52.2 months for those with an upper tract tumour. Four of the five patients presented with haematuria and one was diagnosed on routine follow‐up intravenous urography. The mean time to the diagnosis of an upper tract tumour was 39.6 months. Of the potential risk factors, only the presence of TCC of the prostatic urethra had a statistically significant association with eventual upper tract tumour (P < 0.01). At the last follow‐up, four patients died from urothelial cancer and one was disease‐free. CONCLUSIONS The incidence of upper tract tumour after cystectomy for TCC is low; most patients present with symptoms (haematuria) and have advanced disease at diagnosis. Patients with prostatic urethral involvement at cystectomy are at greater risk of developing upper tract tumour.

AIC-based model ranking is consistent with an independent prediction accuracy test. Biexponential and kurtosis models consistently perform better than stretched and monoexponential models. The biexponential model has increasing superiority over all three other models as maximum b-value increases above ∼2000 s/mm(2).

Diffusion tensor microimaging was used to investigate the water diffusion properties of formalin‐fixed prostate tissue at spatial resolution approaching the cellular scale. Diffusion tensor microimaging was performed at 16.4 T with 40 μm isotropic voxels. Diffusion tensor microimaging clearly demonstrated distinct microscopic diffusion environments and tissue architecture consistent with that seen on light microscopy of the same tissue. The most restricted diffusion environment is the secretory epithelial cell layer (voxel bulk mean diffusivity, D = 0.4 ± 0.1 × 10−3 mm2/sec). Diffusion in the fibromuscular stromal matrix is relatively less restricted (D = 0.7 ± 0.1 × 10−3 mm2/sec). In tumor tissue (Gleason pattern 4+4) distinct glandular and ductal structures are absent in the diffusion‐weighted images and diffusivity is low (D = 0.5 ± 0.1 × 10−3 mm2/sec). Distinct stromal and epithelial diffusion compartments are the most likely origin of biexponential diffusion decay observed in vivo. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.