Electronic tongue for microcystin screening in waters.

The potentiometric E-tongue system was employed for water toxicity estimation in terms of cyanobacterial microcystin toxins (MCs) detection. The data obtained from E-tongue were correlated to the MCs content detected by the standard chromatographic technique UHPLC-DAD (Ultra High Performance Liquid Chromatography with Diode Array Detector), as far as by the colorimetric enzymatic approach. The prediction of MCs released by toxic Microcystis aeruginosa strains was possible with Root Mean Squared Error of Validation (RMSEV) lower or very close to 1µg/L, the provisional guideline value of WHO for MCs content in potable waters. The application of E-tongue system opens up a new perspective offset for fast and inexpensive analysis in the field of environmental monitoring, offering also the possibility to distinguish toxin producing and non-toxic M. aeruginosa strains present in potable water.

Synthesis and characterization of a propazine imprinted polymer for the extraction of triazines herbicides.

A MIP (molecularly imprinted polymer) was synthesized and evaluated for its use as sorbent for solid phase extraction (MISPE) of common used triazines (atrazine and terbuthylazine) and their widespread metabolites (desethyl-atrazine and desethyl-terbuthylazine) in water samples. MIP was produced by bulk polymerisation using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linker, propazine as template and toluene as porogen solvent. Different washing methods of the synthesized polymer were evaluated. Soxhlet extraction provided the best results with a residual concentration of propazine, ranging from 0.78 to 2.86 mug for 1 g of polymer. Capacity factor was calculated using a 5 cm HPLC column filled with MIP and NIP (Not Imprinted Polymer): data extrapolation indicated a log Kw of 4.3 for MIP and a log Kw of 3.5 for NIP. Also frontal analyses confirmed a different behaviour of the two polymers. By comparing the recovery efficiency of MIP with that of traditional LiChrolut EN cartridge in the extraction of a River Po water sample, the results confirmed the reliability of this new technique for the analysis of herbicide compounds.

A multi-biosensor based on immobilized Photosystem II on screen-printed electrodes for the detection of herbicides in river water.

A multi-biosensor for detection of herbicides and pollutants was constructed using various photosynthetic preparations as biosensing elements. The photosynthetic thylakoid from Spinacia oleracea L., Senecio vulgaris and its mutant resistant to atrazine were immobilized with (BSA-GA) on the surface of screen-printed sensors composed of a graphite-working electrode and Ag/AgCl reference electrode deposited on a polymeric substrate. The biosensor was composed of four flow cells with independent illumination of 650 nm to activate electron transfer in Photosystem II. The principle of the detection was based on the fact that herbicides selectively block electron transport activity in a concentration-dependent manner and that the four PSII biomediators show differential recognition activity toward herbicides. Changes of the activity were registered amperometrically as rate of photoreduction of the artificial electron acceptor DQ. The setup resulted in a reusable herbicide multibiosensor with a good stability (half-life of 16.7 h for spinach thylakoids) and limit of detection of about 10(-8) M for herbicides recovered in spring in river.

Degradation and leaching of the herbicides metolachlor and diuron: a case study in an area of Northern Italy.

In this work the degradation of the herbicides metolachlor, diuron, monuron and of the metabolites 2-ethyl-6-methylaniline (EMA), and 3,4-dichloroaniline (DCA) was assessed in laboratory experiments on microbiologically active and sterilized soils. Their leaching potentials were calculated, using Gustafson's equation, by determining their mobility (as Koc) and persistence (expressed as DT50). Lysimeter experiments were also conducted to assess the actual leaching of the studied herbicides in a cereal crop tillage area vulnerable to groundwater contamination. The data obtained from the field were compared to the laboratory results. Moreover, some compounds of particular concern were searched for in the groundwater located near the experimental area in order to evaluate actual contamination and to test the reliability of the leaching potential. The GUS index, computed on data from microbiologically active soil, shows monuron as a leacher compound, EMA and DCA as non-leachers, metolachlor and diuron as transient ones. The presence of metolachlor in the groundwater monitored, even at concentrations up to 0.1 mug/l, confirms the possibility that transient compounds can be leached if microbial activity has not completely occurred in active surface soil.

Studies on mobility and degradation pathways of terbuthylazine using lysimeters on a field scale.

Terbuthylazine [N2-tert-butyl-6-chloro-N4-ethyl-1,3,5-triazine-2,4-diamine] degradation pathways in agricultural soils were evaluated by following the appearance and mobility of its main transformation products: dealkylated and hydroxylated derivatives. Three experimental degradation studies in open field were performed in different hydraulic conditions: constant hydraulic head on topsoil, achieved to simulate the highest-risk situation for the aquifer, intermittent artificial precipitation to simulate a medium-risk situation; and natural precipitation to reproduce the lowest-risk condition. Concentrations of terbuthylazine transformation products derived from dealkylation and hydroxylation reactions were measured in leachates and soil samples collected during the three experiments. Desethylterbuthylazine (DET) and deethylterbuthylazine-2-hydroxide [DETH; 4-amino-6-terbutylamino-(1,3,5)-triazine-2-OH] were found to be the highest-leaching compounds and therefore can be considered as potential pollutants for aquifer contamination.

Effect of acute load of grapefruit juice on urinary excretion of citrate and urinary risk factors for renal stone formation.

The effect of citrus fruit juice ingestion on the risk of calcium oxalate stone formation is still debated. The present study was undertaken to investigate changes in urinary stone risk factors after administration of a soft drink containing grapefruit juice. Seven healthy subjects, with no history of kidney stones, were submitted to an acute oral load (20 ml/kg body weight over 60 min) of a soft drink containing grapefruit juice diluted (10%) in mineral water. After a 7-day wash-out period, each subject underwent an oral load with mineral water alone under the same conditions. Urine specimens were collected before (for 120 min) and after each oral fluid load (for 180 min). Urinary flow was significantly increased after both grapefruit juice (46+/-26 vs 186+/-109 ml/h, p = 0.01) and mineral water (42+/-16 vs 230+/-72 ml/h, p=0.001) compared to baseline. Compared to mineral water, grapefruit juice significantly (p=0.021) increased urinary excretion of citrate (25.8+/-9.3 vs 18.7+/-6.2 mg/h), calcium (6.7+/-4.3 vs 3.3+/-2.3 mg/h, p=0.015) and magnesium (2.9+/-1.5 vs 1.0+/-0.7 mg/h, p=0.003). Citrus fruit juices could represent a natural alternative to potassium citrate in the management of nephrolithiasis, because they could be better tolerated and cost-effective than pharmacological calcium treatment. However, in order to obtain a beneficial effect in the prevention of calcium renal stones a reduced sugar content is desirable to avoid the increase of urinary calcium due to the effect of sugar supplementation.

[Erectile disfunction after non nerve-sparing radical pelvic surgery]. / Disfunzione erettiva da chirurgia pelvica demolitiva non nerve-sparing.

BACKGROUND: The patients who undergo radical pelvic surgery often found that sexual function is impaired. In this research hypothesis, we evaluated the efficacy of alternative therapy to conventional PGE 1 injections, such as the association of Sildenafil and L-Arginine. This association in based on the principle that L-Arginine, the precursor of nitric oxide, improves the effect of Sildenafil, which is effective in the presence of nitric oxide. METHODS: The experimental plan was to make a comparative study of 2 random groups of patients selected from those undergoing radical cystectomies and prostatectomies over the past three years. 116 patients were illegible (64 prostatectomies and 52 cystectomies). The fìrst random group was treated with Sildenafil alone and the second with Sildenafil and L-Arginine. The efficacy of treatment was evaluated by the Buckling test (pressure threshold of cavernous flexation at penile axial rigidity) once-after ambulatorial administration and then by telephonic interview (subjective evaluation) after home administration. RESULTS: The starter dose was 50 mg and was inefficient in both groups (Buckling test between 0 and 250). 100-mg doses gave significant results (Buckling test > 500) in both groups, especially the second. Cardiopathic patients, diabetics and patients with retinal disorders were excluded from the study. The mean age of patients was 65 years. CONCLUSIONS: The resumption of relatively satisfactory sexual activity was demonstrated using non-invasive pharmacological treatment.

[Erectile dysfunction after non-nerve sparing radical pelvic surgery. Therapeutical experience with sildenafil and L-arginine evaluated by Buckling test]. / Disfunzione erettiva da chirurgia pelvica demolitiva non nerve-sparing. Esperienza terapeutica con sildenafil e L-Aginina valutata con Buckling test.

BACKGROUND: Patients undergoing radical pelvic floor surgery are often find that sexual function is impaired. In this research hypothesis, we evaluated the efficacy of alternative therapy to conventional PGE 1 injections, such as the association of Sildenafil and L-Arginine. This association is based on the principle that L-Arginine, the precursor of nitric oxide, improves the effect of Sildenafil, which is effective in the presence of nitric oxide. METHODS: The experimental plan was to make a comparative study between 2 random groups of patients selected from those undergoing radical cystectomies and prostatectomies over the past three years. 116 patients were eligible (64 prostatectomies and 52 cystectomies). The first random group was treated with Sildenafil alone and the second with Sildenafil and L-Arginine. The efficacy of treatment was evaluated using the Buckling test (pressure threshold of cavernous flexation at penile axial rigidity) once after ambulatorial administration and then by telephone interview (subjective evaluation) after administration at domicile. RESULTS: The starter dose was 50 mg and was inefficient in both groups (Buckling test between 0 and 250). 100-mg doses gave significant results (Buckling test >500) in both groups, especially the second. Cardiopathic patients, diabetics and patients with retinal disorders or who were unmotivated were excluded from the study. The mean age of patients was 65. CONCLUSIONS: The resumption of relatively satisfactory sexual activity was demonstrated using non-invasive pharmacological treatment.

Contact laser treatment for benign prostatic hypertrophy.

Transurethral resection of the prostate (TURP) is still the standard treatment of benign prostatic hypertrophy (BPH) but the surgical lasers recently introduced seem to offer the patient a very low perioperative complication rate, a short learning curve, the reduced operating time and the health care system a very low cost/benefit ratio. We report our personal experience with contact vaporizing laser ablation of the prostate (CLAP) paying attention to efficacy, safety and costs. Between December 94 and March 97, 67 pts (mean age 62.8 +/- 9 years) underwent CLAP for BPH (mean prostate volume 40.4 +/- 17.1 cc). Five pts presented coagulation disorders, five were renal transplant recipients and one had chronic renal failure requiring peritoneal dialysis. All patients were preoperatively submitted to digital rectal examination, transrectal prostatic ultrasound, dosage of serum PSA, determination of the International Prostatic Symptom Score (IPSS), the post voiding residual urine and maximum flow rate. All these exams were repeated at 1, 3, 6, 12 and 24 months after CLAP. The bladder pressure at maximum flow (Pdet-Qmax) was preoperatively determined in 23 patients and repeated at the six months follow up. For CLAP we used an SLT neodynium-YAG laser or diode laser with maximum potency 60 W. For statistical analysis we used Student's t-test for paired data. The mean operating time was 47.9 +/- 12.5 min (range 18-75 min) and the laser energy averaged 17.707 +/- 11.239 J (range 3000-58,000 J). The mean catheter time after CLAP was 2.5 days and the mean hospital stay was 4.8 days. No intraoperative complications occurred. Two patients 48/72 h after surgery presented macrohematuria requiring laser revision, three patients presented an acute urinary retention post catheter removal and one patient had acute prostatis. At the follow up, the IPSS score, Q max, Pdet-Qmax and PVU showed a significant statistical difference respect to baseline values. The prostate volume at the 180-day follow up was not significantly different from baseline values (42.1 +/- 16.8 cc vs 40.4 +/- 17.1 cc). Contact laser ablation of the prostate has been demonstrated to be efficacious and comparable to TURP in relieving BPH obstruction however the higher costs exceeding the TURP ones by 13%, the longer operative times and the lower durability of laser disobstruction impede to replace TURP with the CLAP.

Arterial embolization in the treatment of post-traumatic priapism.

Priapism is a prolonged penile erection not associated with sexual arousal. Two types of priapism have been described: the more common one is the "veno-occlusive" priapism and can be frequently observed as the consequence of an intracavernosal injection of vaso-active drugs for the treatment of erectile dysfunction. The less common type of priapism is known as "high flow" priapism and usually follows perineal or direct penile trauma. The clinical presentation in case of high flow priapism is quite typical: hystory of recent penile or perineal trauma followed, by the onset of a painless, incomplete and constant erection of the penis. A color-flow Doppler sonogram should be performed as first diagnostic step: this examination allows to identify the presence of patent cavernous arteries and prominent venous drainage with focal area of high flow turbulence along the pathway of one or both the cavernous arteries. An arterial blood sample taken from the corpora will confirm the diagnosis. At first, conservative therapeutical attempts can be suggested, with mechanical external compression of the perineum, the use of ice packs, corporeal aspiration and irrigation with saline. Besides, intracorporeal administration of alpha-agonists and methylene blue should be performed. Unfortunately, these conservative measures often result unsuccessful, and more invasive approaches must be considered. The radiological superselective transcatheter embolization of the proximal artery supplying arterial-lacunar fistula should be the present treatment of choice in these cases of high-flow priapism refractory to conservative and medical treatments. The first successful management of high flow priapism by selective arterial embolization was reported by Wear and coworkers in 1977. Autologous clots and gelatine sponge have been extensively used and become very popular as the embolic agent. More recently, platinum microcoils have been proposed with the aim to achieve more precise and selective embolization. In our single-case-experience on the treatment of high flow priapism by arterial embolization, we used the recently introduced tungsten microcoils. At the time of the follow-up, 2 months later, patient reported satisfactory intercourse with an approximately 75% of penile rigidity. By comparison with microsurgical ligature of the damaged vessel, selective embolization is, at least theoretically, a less invasive procedure, particularly with reference to the trauma caused to the erectile tissue. High-flow priapism is a fairly rare urological pathology which does not require immediate and emergency treatment (as is the case, instead, with venous-occlusive priapism), since the risk of post-ischaemic fibrosis is excluded thanks to the fact that oxygen is supplied to the cavernous tissue. Once the diagnosis has been established with certainty, therefore, the specialist has the necessary time at disposal to arrange for the most appropriate therapeutic steps. When, as is frequently the case, conservative measures prove ineffective, the current treatment of choice for cases of fistula of the cavernous artery would appear to be superselective embolization of the artery, provided same can be performed at specialized centres and by experienced personnel.

The glutaraldehyde-treated porcine aortic valve. A study of the leaflets' mechanical properties.

The modifications of mechanical properties produced in valvular tissue by glutaraldehyde fixation were studied. Porcine aortic leaflets, fresh and fixed with glutaraldehyde in a stressed state, were tested with a mechanical device. The results we obtained show that the fixed leaflets have a failure load higher than fresh ones and an increased elastic recovery. The time of preservation (up to one year) does not affect the mechanical properties of fixed samples. The temperature of shrinkage was also studied, and we found that fixed leaflets show no shrinkage at all.