Estimate of Opportunistic Prostate Specific Antigen Testing in the Finnish Randomized Study of Screening for Prostate Cancer.

PURPOSE: Screening for prostate cancer remains controversial, although ERSPC (European Randomized Study of Screening for Prostate Cancer) showed a 21% relative reduction in prostate cancer mortality. The Finnish Randomized Study of Screening for Prostate Cancer, which is the largest component of ERSPC, demonstrated a statistically nonsignificant 16% mortality benefit in a separate analysis. The purpose of this study was to estimate the degree of contamination in the control arm of the Finnish trial. MATERIALS AND METHODS: Altogether 48,295 and 31,872 men were randomized to the control and screening arms, respectively. The screening period was 1996 to 2007. The extent of prostate specific antigen testing was analyzed retrospectively using laboratory databases. The incidence of T1c prostate cancer (impalpable prostate cancer detected by elevated prostate specific antigen) was determined from the national Finnish Cancer Registry. RESULTS: Approximately 1.4% of men had undergone prostate specific antigen testing 1 to 3 years before randomization. By the first 4, 8 and 12 years of followup 18.1%, 47.7% and 62.7% of men in the control arm had undergone prostate specific antigen testing at least once and in the screening arm the proportions were 69.8%, 81.1% and 85.2%, respectively. The cumulative incidence of T1c prostate cancer was 6.1% in the screening arm and 4.5% in the control arm (RR 1.21, 95% CI 1.13-1.30). CONCLUSIONS: A large proportion of men in the control arm had undergone a prostate specific antigen test during the 15-year followup. Contamination is likely to dilute differences in prostate cancer mortality between the arms in the Finnish screening trial.

Simultaneous removal of Ni(II), As(III), and Sb(III) from spiked mine effluent with metakaolin and blast-furnace-slag geopolymers.

The mining industry is a major contributor of various toxic metals and metalloids to the aquatic environment. Efficient and economical water treatment methods are therefore of paramount importance. The application of natural or low-cost sorbents has attracted a great deal of interest due to the simplicity of its process and its potential effectiveness. Geopolymers represent an emerging group of sorbents. In this study, blast-furnace-slag and metakaolin geopolymers and their raw materials were tested for simultaneous removal of Ni(II), As(III) and Sb(III) from spiked mine effluent. Blast-furnace-slag geopolymer proved to be the most efficient of the studied materials: the experimental maximum sorption capacities for Ni, As and, Sb were 3.74 mg/g, 0.52 mg/g, and 0.34 mg/g, respectively. Although the capacities were relatively low due to the difficult water matrix, 90-100% removal of Ni, As, and Sb was achieved when the dose of sorbent was increased appropriately. Removal kinetics fitted well with the pseudo-second-order model. Our results indicate that geopolymer technology could offer a simple and effective way to turn blast-furnace slag to an effective sorbent with a specific utilization prospect in the mining industry.

The association between antihypertensive drug use and incidence of prostate cancer in Finland: a population-based case-control study.

Some studies have suggested that use of antihypertensive drugs could decrease prostate cancer risk. We evaluated this association at the population level. All prostate cancer cases in Finland during 1995-2002 and matched controls (24,657 case-control pairs) were identified from the Finnish Cancer Registry and the Population Register Center, respectively. Detailed information on antihypertensive drug purchases was obtained from a national prescription database. Data were analyzed using multivariable-adjusted conditional logistic regression model. Ever use of antihypertensive drugs was associated with marginally elevated overall prostate cancer risk (OR 1.16; 95% CI, 1.12-1.21). Risk of advanced prostate cancer did not differ from the nonusers (OR 1.08, 95% CI 0.98-1.18). The risk increase was observed constantly in all classes of antihypertensive drugs. Our large population-based study generally does not support decreased risk of prostate cancer among antihypertensive drug users. Conversely, an increased overall prostate cancer risk was observed. The association being similar for all drug groups suggests that it is probably caused by a systematic difference between medication users and nonusers, such as differing PSA testing activity.

Removal of ammonium from municipal wastewater with powdered and granulated metakaolin geopolymer.

Ammonium [Formula: see text] removal from municipal wastewater poses challenges with the commonly used biological processes. Especially at low wastewater temperatures, the process is frequently ineffective and difficult to control. One alternative is to use ion-exchange. In the present study, a novel [Formula: see text] ion-exchanger, metakaolin geopolymer (MK-GP), was prepared, characterised, and tested. Batch experiments with powdered MK-GP indicated that the maximum exchange capacities were 31.79, 28.77, and 17.75 mg/g in synthetic, screened, and pre-sedimented municipal wastewater, respectively, according to the Sips isotherm (R2 ≥ 0.91). Kinetics followed the pseudo-second-order rate equation in all cases (kp2 = 0.04-0.24 g mg-1 min-1, R2 ≥ 0.97) and the equilibrium was reached within 30-90 min. Granulated MK-GP proved to be suitable for a continuous column mode use. Granules were high-strength, porous at the surface and could be regenerated multiple times with NaCl/NaOH. A bench-scale pilot test further confirmed the feasibility of granulated MK-GP in practical conditions at a municipal wastewater treatment plant: consistently <4 mg/L [Formula: see text] could be reached even though wastewater had low temperature (approx. 10°C). The results indicate that powdered or granulated MK-GP might have practical potential for removal and possible recovery of [Formula: see text] from municipal wastewaters. The simple and low-energy preparation method for MK-GP further increases the significance of the results.

Sulphate removal over barium-modified blast-furnace-slag geopolymer.

Blast-furnace slag and metakaolin were geopolymerised, modified with barium or treated with a combination of these methods in order to obtain an efficient SO4(2-) sorbent for mine water treatment. Of prepared materials, barium-modified blast-furnace slag geopolymer (Ba-BFS-GP) exhibited the highest SO4(2-) maximum sorption capacity (up to 119mgg(-1)) and it compared also favourably to materials reported in the literature. Therefore, Ba-BFS-GP was selected for further studies and the factors affecting to the sorption efficiency were assessed. Several isotherms were applied to describe the experimental results of Ba-BFS-GP and the Sips model showed the best fit. Kinetic studies showed that the sorption process follows the pseudo-second-order kinetics. In the dynamic removal experiments with columns, total SO4(2-) removal was observed initially when treating mine effluent. The novel modification method of geopolymer material proved to be technically suitable in achieving extremely low concentrations of SO4(2-) (<2mgL(-1)) in mine effluents.