Phase 3 clinical trial investigating the effect of selenium supplementation in men at high-risk for prostate cancer.

PURPOSE: This study was conducted to investigate the effect of Se supplementation on prostate cancer incidence in men at high risk for prostate cancer. METHODS: A Phase 3 randomized, double-blind, placebo-controlled clinical trial was conducted in 699 men at high risk for prostate cancer (prostate specific antigen (PSA) >4 ng/ml and/or suspicious digital rectal examination and/or PSA velocity >0.75 ng/ml/year), but with a negative prostate biopsy. Participants were randomized to receive daily oral placebo (N = 232), 200 µg selenium (N = 234), or 400 µg selenium (N = 233) as selenized yeast. They were followed every 6 months for up to 5 years. The time to diagnosis of prostate cancer was compared between treatment groups using the Cox proportional hazards model. RESULT: Compared to placebo, the hazard ratios [95% confidence intervals] for risk of developing prostate cancer in the selenium 200 µg/day or the selenium 400 µg/day group were 0.94 [0.52, 1.7] and 0.90 [0.48, 1.7], respectively. PSA velocity in the selenium arms was not significantly different from that observed in the placebo group (P = 0.18 and P = 0.17, respectively). CONCLUSION: Selenium supplementation appeared to have no effect on the incidence of prostate cancer in men at high risk. In conjunction with results of other studies, these data indicate that selenium supplementation may not have a role in prostate cancer chemoprevention.

Aspiration and sclerotherapy of hydroceles and spermatoceles/epididymal cysts with 100% alcohol.

OBJECTIVE: To evaluate the efficacy of aspiration and sclerotherapy with 100% alcohol for the primary treatment of benign scrotal cysts. METHODS: From March 2014 to March 2018, 114 patients were identified who underwent their first aspiration and sclerotherapy procedure (80 hydroceles and 34 spermatoceles/epididymal cysts). The procedure was carried out in the outpatient clinic with local anaesthesia. A 16-gauge IV catheter is used to puncture the sac under aseptic conditions. The volume of alcohol instilled was 10% of the aspirated volume (maximum of 50 mL). Patients were then observed in the waiting room and completed a questionnaire. Urology clinic follow up was scheduled at 6 weeks. RESULTS: At follow up, 54 patients (67.5%) with hydroceles and 25 patients (73.5%) with spermatoceles/epididymal cysts had resolution after a single procedure. A second procedure was offered if fluid collection persisted, of which 71% of patients with hydroceles and 100% of patients with spermatoceles/epididymal cysts had a successful outcome. At a median of 31 months post-initial procedure, the overall success rate, after at most two procedures, was 80% for hydroceles and 85% for spermatoceles/epididymal cysts. The complication rate was low (6%). Almost all patients were happy to undergo the procedure again, if needed. Persistence following aspiration and sclerotherapy were more likely to occur in younger patients (45.4 versus 61.2 years, P = 0.001). Persistence was not related to the volume of fluid aspirated. CONCLUSION: Aspiration and sclerotherapy with alcohol is a reliable, safe and effective technique for treatment of benign scrotal cysts.

Use of Surface Photovoltage Spectroscopy to Measure Built-in Voltage, Space Charge Layer Width, and Effective Band Gap in CdSe Quantum Dot Films.

Surface photovoltage spectroscopy (SPS) was used to study the photochemistry of mercaptoethanol-ligated CdSe quantum dot (2.0-4.2 nm diameter) films on indium doped tin oxide (ITO) in the absence of an external bias or electrolyte. The n-type films generate negative voltages under super band gap illumination (0.1-0.5 mW cm(-2)) by majority carrier injection into the ITO substrate. The photovoltage onset energies track the optical band gaps of the samples and are assigned as effective band gaps of the films. The photovoltage values (-125 to -750 mV) vary with quantum dot sizes and are modulated by the built-in potential of the CdSe-ITO Schottky type contacts. Deviations from the ideal Schottky model are attributed to Fermi level pinning in states approximately 1.1 V negative of the ITO conduction band edge. Positive photovoltage signals of +80 to +125 mV in films of >4.0 nm nanocrystals and in thin (70 nm) nanocrystal films are attributed to electron-hole (polaron) pairs that are polarized by a space charge layer at the CdSe-ITO boundary. The space charge layer is 70-150 nm wide, based on thickness-dependent photovoltage measurements. The ability of SPS to directly measure built-in voltages, space charge layer thickness, sub-band gap states, and effective band gaps in drop-cast quantum dot films aids the understanding of photochemical charge transport in quantum dot solar cells.

Quantum confinement controls photocatalysis: a free energy analysis for photocatalytic proton reduction at CdSe nanocrystals.

The ability to adjust the mechanical, optical, magnetic, electric, and chemical properties of materials via the quantum confinement effect is well-understood. Here, we provide the first quantitative analysis of quantum-size-controlled photocatalytic H2 evolution at the semiconductor-solution interface. Specifically, it is found that the hydrogen evolution rate from illuminated suspended CdSe quantum dots in aqueous sodium sulfite solution depends on nanocrystal size. Photoelectrochemical measurements on CdSe nanocrystal films reveal that the observed reactivity is controlled by the free energy change of the system, as determined by the proton reduction potential and the quasi-Fermi energy of the dots. The corresponding free energy change can be fitted to the photocatalytic activity using a modified Butler-Volmer equation for reaction kinetics. These findings establish a quantitative experimental basis for quantum-confinement-controlled proton reduction with semiconductor nanocrystals. Electrochemical data further indicate that proton reduction occurs at cadmium sites on the dots, and that charge separation in these nanocrystals is controlled by surface effects, not by space charge layers.

A randomized pilot trial of dietary modification for the chemoprevention of noninvasive bladder cancer: the dietary intervention in bladder cancer study.

Epidemiological data suggest robust associations of high vegetable intake with decreased risks of bladder cancer incidence and mortality, but translational prevention studies have yet to be conducted. We designed and tested a novel intervention to increase vegetable intake in patients with noninvasive bladder cancer. We randomized 48 patients aged 50 to 80 years with biopsy-proven noninvasive (Ta, T1, or carcinoma in situ) urothelial cell carcinoma to telephone- and Skype-based dietary counseling or a control condition that provided print materials only. The intervention behavioral goals promoted seven daily vegetable servings, with at least two of these as cruciferous vegetables. Outcome variables were self-reported diet and plasma carotenoid and 24-hour urinary isothiocyanate (ITC) concentrations. We used two-sample t tests to assess between-group differences at 6-month follow-up. After 6 months, intervention patients had higher daily intakes of vegetable juice (P = 0.02), total vegetables (P = 0.02), and cruciferous vegetables (P = 0.07); lower daily intakes of energy (P = 0.007), fat (P = 0.002) and energy from fat (P = 0.06); and higher plasma α-carotene concentrations (P = 0.03). Self-reported cruciferous vegetable intake correlated with urinary ITC concentrations at baseline (P < 0.001) and at 6 months (P = 0.03). Although urinary ITC concentrations increased in the intervention group and decreased in the control group, these changes did not attain between-group significance (P = 0.32). In patients with noninvasive bladder cancer, our novel intervention induced diet changes associated with protective effects against bladder cancer. These data show the feasibility of implementing therapeutic dietary modifications to prevent recurrent and progressive bladder cancer.

Quantum confinement controlled photocatalytic water splitting by suspended CdSe nanocrystals.

The photocatalytic hydrogen production of CdSe nanocrystals (1.75-4.81 nm) in the presence of aqueous sodium sulphite depends exponentially on the bandgap of the particles, confirming that the material's activity is controlled by the degree of quantum confinement.