Phytoassessment of acid mine drainage: Lemna gibba bioassay and diatom community structure.

An integrated multilevel phytoassessment of an acid mine drainage (AMD, pH range 3.3-6.8) in southern Portugal was performed. A 7-day phytotoxicity bioassay with the duckweed Lemna gibba (chlorosis, necrosis, growth) was carried out, both in the laboratory and in situ, combined with an analysis of the resident epilithic diatom community. The toxicity test was performed with water from the AMD gradient, an unpolluted river control and acidified control water, in order to discriminate potential pH-effects from combined pH- and metal-effects. Diatom communities discriminated well among the sites (alkalophilic species versus halobiontic, acidobiontic and acidophilic species), showing inter-site differences to be larger than intra-site seasonal variations. In L. gibba exposed to AMD, necrosis and growth inhibition were higher in situ compared to the laboratory experiments. L. gibba was more sensitive to AMD than to acidified water. Already after 4 days, growth rate inhibition in L. gibba proved to be a reliable indicator of AMD-stress. Ecotoxicological thresholds obtained with L. gibba corresponded with those obtained previously with animals of intermediate tolerance to AMD. The results were summarised in a multimetric index.

Morbidity and discomfort of ten-core biopsy of the prostate evaluated by questionnaire.

Transition zone biopsies have been found to increase the detection rates of cancer of the prostate in patients with negative digital rectal examination. There are however no data available whether the higher biopsy rate is associated with greater morbidity. The present study was therefore designed to evaluate the complication rate of extended sextant biopsy. In this prospective study, 162 consecutive patients who presented for prostatic evaluation were included. After starting prophylactic antibiotic treatment 48 h prior to the procedure, transrectal ultrasound-guided core biopsies were obtained from each lobe: three each from the peripheral zone (apex, mid-zone and base) and two from the transition zone of each prostatic lobe. In all patients a questionnaire was obtained 10-12 days after the procedure. Major complications occurred in 3 patients. In 2 of the 3 cases major macroscopic hematuria was treated by an indwelling catheter for 1 or 2 days and 1 patient developed fever >38.5 degrees C for 1 day. Minor macroscopic hematuria was present in 68.5% of the patients. In 17.9% of these cases, the hematuria lasted for more than 3 days. Hematospermia was observed in 19.8% and minor rectal bleeding occurred in 4.9%. Ten-core biopsies did not lead to an increase in adverse effects or complications when compared to the results of sextant biopsies reported in the literature.