169,507 research outputs found
Piano di risanamento e tutela dalle esposizioni ai campi elettromagnetici del Comune di Aprilia
No full textIl Piano di risanamento e tutela dalle esposizioni ai campi elettromagnetici del Comune di Aprilia, è stato redatto nel 2002 su incarico del comune di Aprilia. Si compone di una relazione di piano, di alcuni studi di settore (Percezione sociale del problema "elettrosmog"; Misurazioni sul campo dei valori di c.e.m; Esperienze di reti di monitoraggio esposizione c.e.m.; Programmi di sviluppo degli enti gestori di telefonia mobile; Regolamenti comunali in materia di tutela alla esposizione ai c.e.m.; Quadro normativo di riferimento), di tavole di indagine e di progetto, di un Regolamento comunale per la verifica di compatibilità territoriale dei sistemi radio elettrici ad elevata frequenza (100 Khz - 300 GHz)
Preemptive port site local anesthesia in gynecologic laparoscopy: a randomized, controlled trial
No full textSTUDY OBJECTIVE: To assess the impact of preemptive infiltration of port site with local anesthetic on postlaparoscopy pain.DESIGN: Randomized, double-blind, controlled trial (Canadian Task Force classification I).
SETTING: Two university hospitals.
PATIENTS: A total of 170 women scheduled for gynecologic laparoscopic procedures were randomly assigned to pre-incisional infiltration with ropivacaine (n = 86) or with saline solution (n = 84).
INTERVENTIONS: Infiltration with either local anesthetic or placebo was accomplished in each port site before skin incision. All patients underwent standard anesthesia induction and maintenance.
MEASUREMENTS AND MAIN RESULTS: Postoperative pain was evaluated with a visual analogue scale and patient interview at 1, 3, and 24 hours after surgery. No difference was found between groups in pain levels, pain location, or in the site of superficial pain at any of the postoperative time periods. The proportion of women requiring analgesia before discharge was similar in the local anesthetic group and in the saline group (22/86 [25.6%] vs 19/84 [22.6%], p = .72). The analgesic consumption in the first 24 hours after surgery and the time to first analgesic request did not differ significantly between the two groups.
CONCLUSION: Preemptive infiltration of trocar sites with ropivacaine is not effective in postoperative pain relief
Evaluation of Some Experimental Parameters in the Determination the Ratios of Cortisol to Cortisone and their Tetrahydrometabolites in Urine
No full textIntroduction of a perfusion on-line cleanup for the elimination of proteic matter buildup onto the HPLC column
Cortisol (F) plays an important role in human physiology and is a marker for the diagnosis of many pathological states. It is secreted by the adrenal glands, while cortisone is produced by 11β-hydroxysteroid dehydrogenase (11β-HSD) isoenzymes, which interconvert cortisol to hormonally inactive cortisone. Cortisol concentrations in the body are controlled by the relative activity of 11β-HSD type 1, which is responsible for the reversible conversion of cortisone to cortisol, and 11β-HSD type 2 that catalyzes the irreversible conversion of cortisol to cortisone. A correct balance between the type 1 and 2 enzymatic activities maintains the physiological level of cortisol. The ratio of either cortisol to cortisone (F/E) or that of some metabolites allows an evaluation of the activity of 11β-HSD.
Sample preparation: centrifugation at 5000 rpm, enzyme hydrolysis by β-Glucuronidase/Arylsulfatase in acetate buffer 0.5 M (pH 5.1) containing IS, 1:20 (v/v) dilution with water. On-line cleanup: SPE by perfusion column Applied Biosystems POROS R1/20 2.1 x 30 mm. HPLC separation: the column (Phenomenex Luna C8 2 mm x 50 mm, 3 μm particle size), kept at 50 °C, is eluted at 250 μl/min by a two solvents gradient, where solvent A is water/methanol (50/50, v/v) with 0.1% formic acid, and solvent B is methanol/acetonitrile (50/50, v/v), containing 0.1% formic acid too. MS-MS detection: MRM, performed on an Applied Biosystems API 4000 triple quadrupole mass spectrometer, equipped with a turbo ionspray source.
The main target of this work is the optimization of a previously presented method for the determination of tetrahydrocortisol (THF), allo-tetrahydrocortisol (A-THF) and tetrahydrocortisone (THE) and their ratio (THF +A-THF)/THE. In this respect we introduced the parent compounds E and F in order to get the F/E ratio as well. Moreover we checked the influence of some potentially critical parameters, such as the use of water or urine for the calibration standards, the response factor of THF and A-THF and the on-line SPE conditions. Our findings demonstrate that calibration standars can be prepared in water, as the influence of the matrix on the ratio is negligible and it is possible to use either THF or A-THF as a standard for the calibration of both. The final method was tested with some batches of samples, and it demonstrated its reliability and ruggedness. On the contrary of what observed in our previous reports, HPLC performances remain stable for hundreds of injections, without any degradation of the HPLC column, very likely due to some proteic matter buildup
direct determination of the ratio of tetrahydrocortisol+allo-tetrahydrocortisol to hydrocortisone in urine by lc-ms-ms
No full textThe 11β-hydroxysteroid dehydrogenase (11β-HSD) is responsible for the interconversion of both the hormonally inactive cortisone and the active cortisol. This enzyme activity, which has implications in the pathogenesis of numerous diseases, is reflected in the ratio of tetrahydrometabolites of cortisol (allo-tetrahydrocortisol and tetrahydrocortisol) to those of cortisone (tetrahydrocortisone). Several methods have been proposed in the literature to determine such a ratio in urine. Most of them require tedious and extensive extraction and derivatization steps and make use of gas-chromatographic techniques, including gas chromatography coupled to mass spectrometry (GC–MS). We present here an alternative approach for the direct determination of such a ratio in urine by using liquid chromatography–electrospray ionization–tandem mass spectrometry (LC–ESI–MS–MS), based on a minimal sample treatment. Actually, the limit of detections (LODs) for pure standards in water permitted a simple dilution of the urine samples prior to the analysis, hence, an accurate optimization of the high performance liquid chromatography (HPLC) separation was needed in order to get rid of the severe influence of the urine matrix on the ionization efficiency. Besides, the nature of some interfering species was deeply investigated, as well as the suitability of some commercial deuterated steroids as internal standards. All these led to the final method, which was based on a HPLC separation on a C8 column and a ternary gradient water/methanol/acetonitrile. In parallel, an appropriate sample preparation was set up, which consisted of an enzymatic hydrolysis of the conjugated species and a followed 1:20 dilution. Preliminary measurements on real urine samples were performed as well
Evaluation of a Custom Built Atmospheric Pressure PhotoIonization (APPI) Source
No full textApplication of a novel ionization technique, APPI, to the analysis of complex matrices.
An APPI source has been built in collaboration with the mass spectrometry facility of the University of Groningen (NL), coordinated by Dr. Andries P. Bruins. Such a source has been adapted to be used on a PE Sciex API III plus triple quadrupole mass spectrometer. The main target of this research was the evaluation of the performance of the source, the study of the influence of some mechanical solutions, and an investigation on the fields of applications, also in term of comparison with Ionspray (ISI) and Atmospheric Pressure Chemical Ionization (APCI).
Most of the experiments were performed by Flow Injection Analysis (FIA), taking advantage of tandem mass spectrometry in Selected Reaction Monitoring (SRM) mode. We used fairly standard conditions for ISI and APCI, both in positive and negative ion mode, depending on the analyte examined. The APPI conditions were tuned starting from the APCI conditions. Toluene was used as a dopant for APPI experiments, flowing at 30 .micro.l/min, with a mobile phase flow rate of 200 .micro.l/min.
We started the comparison of the different ionization techniques taking into consideration some classes of food components that, in principle, could be considered amenable to APPI. In particular we tested the methods on some phenolic antioxidants present in wine (catechin, quercetin and resveratrol), on one present in olive oil (oleuropein), on .alpha.-, .gamma.- and .delta.-tocopherols, on some components present in essential oils from citrus fruits (coumarins, psoralenes and polymethoxyflavons). Furthermore, we studied the application to some different classes of compounds, and among them polychlorobiphenyls in some matrices
Identification of 9(E),11(E)-18 : 2 fatty acid methyl ester at trace level in thermal stressed olive oils by GC coupled to acetonitrile CI-MS and CI-MS/MS, a possible marker for adulteration by addition of deodorized olive oil RID F-5802-2010
No full textThe olive oil market is suffering from sophisticated illegal treatments. One common adulteration process consists of the addition to virgin olive oil of lower quality oils, such as “lampante” oil, an inexpensive oil and with some organoleptic defects, which is then submitted to thermal deodorization under vacuum processes for removal of the undesired flavor components. Such a blending may not have a huge influence on the chemical composition and may not significantly affect the parameters usually checked as quality indicators, although the organoleptic properties may change. As a consequence, a major effort is being devoted to find reliable markers able to unmask such adulterations. We report here the complete characterization of a compound, detected at trace levels exclusively in thermal stressed oils, which could be a candidate marker for adulteration. The investigation, carried out by GC-MS and GC-MS/MS, provided its complete structure, including the stereochemistry, shown to be a 9(E),11(E)-18:2 fatty acid methyl ester. Experimental data also confirmed the influence of both temperature and heating time on formation and concentration of this compound
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