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Biomedical subjects

E Davoli

Publications and source records attributed to E Davoli.

At least 19 recordsLinked to original sources
PubMed2003

Characterisation of odorants emissions from landfills by SPME and GC/MS.

Odorous compounds from a landfill have been characterised by gas-chromatography-mass-spectrometry, identifying about 100 volatile organic compounds. Air samples from different landfill sites and from the environment have been analysed after a solid-phase microextraction on a three-phase fiber, DVB/Carboxen/PDMS, which allowed a preconcentration and the chromatographic data obtained from the most significant emission sources have been submitted to chemometric analysis in order to better establish specific markers of olfactory pollution. For example limonene was a typical tracer of fresh wastes, while p-cymene was characteristic of leachate and biogas. By the developed analytical procedure it has been evaluated the efficiency of a scrubber plant utilised in the landfill in order to remove malodour compounds. The average removal efficiency was not very high (about 23.5%) due to scarce ability in removing low polarity compounds. Furthermore, it has been demonstrated the suitability of a microgas chromatograph for the continuous on-site monitoring of air pollution in order to rapidly individuate emission sources of olfactive nuisances.

Air Pollutants↗
PubMed1998

Rapid solid-phase extraction method for automated gas chromatographic-mass spectrometric determination of nicotine in plasma.

The aim of this study was to develop a simple, rapid and sensitive assay of nicotine in plasma for automated gas chromatographic-mass spectrometric analysis. Biological samples were extracted using pre-packed Extrelut-1 columns with 5 ml of ethyl acetate. Quantitative analysis was done using deuterium-labelled nicotine as internal standard. The limit of quantitation was 0.5 ng in 1-ml plasma samples. Precision was ranging from 13.3% to 1.64% (R.S.D.) depending on the concentration, while the deviation was 4.16%. This method has been used for determination of nicotine bioavailability from new, low-dosage, nicotine chewing gum strips.

Adult↗
PubMed1998

Industrial pollutants in ground waters from northern Milan.

Ground water samples from an industrialised area near Milan were analysed by gas chromatography-mass spectrometry (GC-MS) to identify the main pollutants and to quantify two classes of chemicals: polychloro-1,3-butadienes (PCBD) and some aromatic amines. The water contained several halogenated aromatic and aliphatic compounds and heavy contamination due to PCBD, probably arising from contaminated land where a disused chemical plant is located. All the samples contained low levels of aromatic amines indicating a diffuse contamination probably arising from different sources.

Amines↗
PubMed1996

On-line monitoring of benzene air concentrations while driving in traffic by means of isotopic dilution gas chromatography/mass spectrometry.

There is no shortage of information about the average benzene concentrations in urban air, but there is very little about microenvironmental exposure, such as in-vehicle concentrations while driving in various traffic conditions, while refuelling, or while in a parking garage. The main reason for this lack of data is that no analytical instrumentation has been available to measure on-line trace amounts of benzene in such situations. We have recently proposed a highly accurate, high-speed cryofocusing gas chromatography/mass spectrometry (GC/MS) system for monitoring benzene concentrations in air. Accuracy of the analytical data is achieved by enrichment of the air sample before trapping, with a stable isotope permeation tube system. The same principles have been applied to a new instrument, specifically designed for operation on an electric vehicle (Ducato Elettra, Fiat). The zero emission vehicle and the fully transportable, battery-operated GC/MS system provide a unique possibility of monitoring benzene exposure in real everyday situations such as while driving, refuelling, or repairing a car. All power consumptions have been reduced so as to achieve a battery-operated GC/MS system. Liquid nitrogen cryofocusing has been replaced by a packed, inductively heated, graphitized charcoal microtrap. The instrument has been mounted on shock absorbers and installed in the van. The whole system has been tested in both fixed and mobile conditions. The maximum monitoring period without external power supply is 6 h. The full analytical cycle is 4 min, allowing close to real-time monitoring, and the minimum detectable level is 1 microgram/m3 for benzene. In-vehicle monitoring showed that, when recirculation was off and ventilation on, i.e., air from outside the vehicle was blown inside, concentrations varied widely in different driving conditions: moving from a parking lot into normal traffic on an urban traffic condition roadway yielded an increase in benzene concentration from 17 to 62.3 micrograms/m3 even if the actual distance was small. A larger increase was observed when a car was left with the engine running at a distance 2 m from the zero emission vehicle: We measured an increment of benzene concentrations from 15.2 to 174.4 micrograms/m3 with a car equipped with a catalytic converter, and from 19.1 to 386.3 micrograms/m3 with a car without such a converter.

Air Pollutants↗
PubMed1996

Validity of self-reported smoking habits in pregnancy: a saliva cotinine analysis.

BACKGROUND: We examined the validity of self-reported cigarette smoking during the third trimester of pregnancy using saliva cotinine as a marker. METHODS: Eligible for the study were 109 pregnant women attending the outpatient Prenatal Service of the Luigi Mangiagalli Clinic (the largest maternity clinic in Milan) for routine prenatal visits during the third trimester of pregnancy on twenty days in 1994. Women self-reporting current smoking or quitting smoking in pregnancy were asked to provide a saliva sample. Cotinine concentration was analyzed and classified as follows: cotinine not detectable, not probable nicotine use or passive exposure; cotinine <10 ng/ml, not probable nicotine use/probable passive exposure; cotinine, > or = 10 ng/m, probable occasional or regular nicotine use. RESULTS: A total of 57 (52.3%) women were non-smokers at conception and were excluded from any subsequent analysis. Of the remaining 52 women, 25 self-reported quitting smoking in pregnancy and 27 were current smokers. Saliva cotinine levels were below 10 in 20 of the 25 subjects reporting quitting smoking in pregnancy. The five cases with cotinine > or = 10 reported a husband smoking more than 10 cigarettes per day. Among the 26 current smokers, seven had a cotinine level <10 ng/ml (four reported smoking fewer then five cigarettes per day and two reported smoking five or more per day); in 20 cases the cotinine value was > or = 10 ng/ml. CONCLUSIONS: These findings provide evidence of a satisfactory validity of self-reported smoking habits in pregnancy.

Adolescent↗
PubMed1993

Purification and analysis of drug residues in urine samples by on-line immunoaffinity chromatography/high-performance liquid chromatography/continuous-flow fast atom bombardment mass spectrometry.

An automatic system for the on-line extraction and analysis of diethylstilbestrol in the urine of rats and calves is described. Extraction was done by injecting samples directly into an immunoaffinity column containing antidiethylstilbestrol antibodies bound to a Sepharose matrix, and analysis was done by on-line high-performance liquid chromatography with ultraviolet and continuous-flow fast atom bombardment mass spectrometry detectors. The system, consisting of one injector, two switching valves, and three pumps, was operated under computer control and allowed to perform a complete analysis of a sample in 28 min. An accurate quantitation by isotope dilution was also possible, by the use of deuterated diethylstilbestrol as internal standard. The sensitivity of the method, using selected-ion monitoring of the molecular ion of diethylstilbestrol, was 2 ng/mL, injecting 1 mL of urine sample. Results obtained from analyzing the urine of rats and calves treated with diethylstilbestrol are presented.

Animals↗
PubMed1993

Mass spectrometric identification and analysis of some aphidicolin metabolites in cancer patients.

We used gas chromatography/mass spectrometry to identify and quantitate some aphidicolin metabolites in plasma and urine of patients receiving aphidicolin-17-glycinate. The major metabolite found in plasma was 3-ketoaphidicolin, present at about one thent the concentrations of aphidicolin. 3-Ketoaphidicolin undergoes dehydroxymethylation to give 18-nor-3-ketoaphidicolin. This metabolite was also found in plasma and its concentration reached a maximum of 1% of aphidicolin. Small amounts of aphidicolin and 3-ketoaphidicolin were found free in urine but almost all of the drug was conjugated to glucuronic acid, as shown by mass spectrometric analysis of urine extracts and by enzymatic digestion with beta-glucoronidase followed by gas chromatographic/mass spectrometric analysis.

Animals↗
PubMed1993

An evaluation of fetal glucogenesis in intrauterine growth-retarded pregnancies.

The presence of fetal glucogenesis was evaluated in nine patients with pregnancies complicated by intrauterine growth retardation (IUGR) at the time of fetal blood sampling (FBS) between 29 and 35 weeks of pregnancy. Eight were singleton pregnancies and one was a twin pregnancy in which blood samples were obtained from both twins. A maternal primed-constant infusion of D(U-13C]glucose was performed, and the presence of fetal glucogenesis was assessed by a comparison of steady-state maternal and fetal glucose enrichments. No significant difference was present between maternal and fetal molar percent excess ([MPE] P = .97), and the mean fetal to maternal (F/M) MPE ratio (0.99 +/- 0.01) was not significantly different from 1 (P = .76). F/M MPE ratio was independent of the time of FBS and umbilical venous glucose and lactate concentrations. Thus fetal glucogenesis is not demonstrable in a group of fairly severe growth-retarded fetuses after an overnight fast with this relatively noninvasive approach.

Adult↗
PubMed1993

Impact of conceptus mass on glucose disposal rate in pregnant women.

The impact of an increasing fetal and placental mass on maternal glucose disposal rate (GDR) was studied in 17 pregnant women. Eleven pregnancies were singleton pregnancies, five were twin and one was a triplet pregnancy. Both the maternal fasting glucose concentration [Glc] and the total fetal and placental weight (W) were significantly correlated with an increased maternal GDR. Glucose concentration and conceptus weight were interdependent. The multiple linear regression of glucose disposal rate on glucose concentration and total weight is given by GDR = -1.573 + 0.176W + 0.932[Glc] +/- 0.24, r2 = 0.52, P < 0.01. These data are utilized to estimate the glucose utilization rate of the human conceptus at a fasting glucose concentration of 3.9 mM with a range of 10-15 mg.kg-1.min-1. Maternal GDR increases with increasing glucose concentration at a rate similar to that reported for newborn infants, consistent with a high glucose utilization by the uterus.

Adult↗
PubMed1993

[The role of echography in assessing abdominal trauma: the experience of 1750 cases].

The authors report their experience of 1750 ultrasonic examinations of the abdomen performed in emergency, showing the value and usefulness of echo-scans in the evaluation of abdominal traumas. Easy and quick to perform, it permits an accurate diagnosis with a low ratio of error. Particularly, ultrasonography gives the chance to operate in emergency patients with steady haemodynamic conditions and to follow up those with partial parenchymal lesions, monitoring the clinical status in order to properly choose between conservative treatment and delayed surgery.

Abdomen↗
PubMed1992

Activity of aphidicolin glycinate alone or in combination with cisplatin in a murine ovarian tumor resistant to cisplatin.

Aphidicolin, a reversible inhibitor of DNA polymerase alpha and delta, has recently been reported to reverse the resistance to cisplatin (DDP) of an ovarian cancer cell line. We investigated the pharmacokinetics of aphidicolin in mice and examined its activity either alone or in combination with DDP in the DDP-sensitive M5076 (M5) murine reticular cell sarcoma as well as in a DDP-resistant subline (M5/DDP). The drug was cleared from plasma very rapidly (clearance, 41.6 ml min-1 kg-1), showing a half-life of 15 min. Aphidicolin concentrations in the tumor were approximately 50% of those found in plasma at steady state. Using several dose schedules and continuous infusions we failed to detect significant antitumor activity for aphidicolin glycinate. Potentiation of the activity of DDP by aphidicolin glycinate was moderate in mice bearing M5 tumor as well as in those bearing M5/DDP tumor. These data do not support the possible clinical use of aphidicolin in combination with DDP. However, further studies should be carried out in different tumor models before this possibility is conclusively ruled out.

Animals↗
PubMed1991

Phase I and clinical pharmacological evaluation of aphidicolin glycinate.

The toxicity profile and the pharmacokinetics of aphidicolin glycinate, a water-soluble analogue of aphidicolin, have been evaluated in two consecutive phase I clinical studies. In the first study, aphidicolin glycinate was given by 1-hour infusion for 5 consecutive days, every 3 weeks (daily x 5 study); in the second study, which was planned on the basis of the pharmacokinetic information obtained in the previous study, the drug was given by 24-hour continuous infusion. Treatment was repeated every 3 weeks. In the daily x 5 study, the daily dose was escalated from 12 mg/m2 to the maximum tolerated dose of 2250 mg/m2. Local toxicity was dose limiting. Elimination half-life was 2 +/- 0.2 hours (mean +/- SE) with aphidicolin being undetectable 6-8 hours after the end of the infusion. In the 24-hour continuous-infusion study, the dose was escalated from 435 mg/m2 to the maximum tolerated dose of 4500 mg/m2. Local toxicity was dose limiting, while other toxic effects were absent. The experimentally determined concentrations at the steady state were in agreement with those predicted on the basis of the available pharmacokinetic data. The targeted concentration at the steady state of 3 micrograms/mL was achieved at doses greater than or equal to 3000 mg/m2. Twenty-four-hour continuous infusion is the recommended schedule for clinical evaluations of aphidicolin glycinate as the synchronizing agent or in combination with cisplatin.

Adult↗
PubMed1991

Migration of vinyl chloride into PVC-bottled drinking-water assessed by gas chromatography-mass spectrometry.

The migration of vinyl chloride (VC) into drinking-water bottled in polyvinyl chloride (PVC) was studied in relation to storage time, using a gas chromatographic-mass spectrometric method. Trideuterated vinyl chloride was used as internal standard. VC concentrations in the water rose progressively in direct (linear) relation to the time after bottling (about 1 ng/litre/day). The time of storage of PVC-packaged foodstuffs may affect the daily oral intake of this monomer, which in some cases may exceed 100 ng/person/day.

Drinking↗
PubMed1991

[Cancer of the breast and the receptor status].

Correlation between survival and hormonal receptor status in patients with breast cancer is still controversial. The results of a study carried out, from 1973 to 1988, on 55 patients (average age 56.7) affected with breast cancer and submitted to radical (Halsted) mastectomy, are reported. Estradiol receptors (ER) and progesterone receptors (PR) were determined using the dextran-coated charcoal (DCC) method and the enzymatic immuno assay (EIA). The threshold value for defining the ER positivity was 10 f/mole/mg of cytosol protein and 50 f/mole/mg for PR positivity. Forty-one patients resulted as ER+, 31 were also PR+. Moreover, 41 patients were treated with tamoxifen (10 mg x 2 die per os). In a 15-year follow-up, no significant difference in survival rate between patients with receptor-positive tumors or treated with tamoxifen and patients with receptor-negative tumors was recorded.

Adult↗
PubMed1990

Drug interaction between cyclosporin A and nizatidine in Sprague-Dawley rats.

The H2-receptor antagonists seem to be effective in prevention and treatment of stress ulcer in transplant recipients. In a previous study on rats, an increase was observed in cyclosporinaemia and hepatotoxicity after administration of cimetidine or ranitidine in association with cyclosporin A (CyA). On the contrary, famotidine does not influence the blood CyA levels. The aim of the study was to detect the possible synergistic nephro- and hepatotoxicity of nizatidine administered in association with CyA, assaying the serum creatinine, the ALT and AST levels, and histological features of thirty young male Sprague-Dawley rats, divided into 6 groups of five animals each. After 10 days, all the rats were sacrificed, their blood was collected to assay serum creatinine, ALT, AST and serum CyA levels: kidneys and livers were processed for light microscopy. The results obtained demonstrated that, while the level of creatinine was normal in each group, the average level of transaminase and the serum levels of CyA were significantly higher in the animals receiving the association of CyA and nizatidine. Furthermore, this group demonstrated a mild infiltrate of the liver characterized in some cases with eosinophilic polymorphonuclear cells. In light of the results obtained, it is probable that the increase of cyclosporinaemia is the consequence of an enhanced hepatotoxicity due to administration of CyA in association with nizatidine.

Animals↗
PubMed1986

Serum methanol concentrations in rats and in men after a single dose of aspartame.

Serum methanol concentrations were measured in rats and in humans given oral aspartame. The dose given to rats was the FDA's projected 99th percentile daily intake for humans, assuming aspartame were to replace all sucrose sweeteners in the diet (34 mg/kg). Four male adult volunteers each received 500 mg, equivalent to 6-8.7 mg/kg, which is approximately the FDA's estimate of mean daily human consumption. Both treatments caused a rise in serum methanol. In rats the mean peak value was 3.1 mg/litre 1 hr after administration; serum methanol returned to endogenous values 4 hr after treatment. In the men, the mean rise over endogenous values was 1.06 mg/litre after 45 min. Two hours after treatment, serum methanol had returned to basal levels. The temporary serum methanol increase showed peak values within the range of individual basal levels.

Adult↗
PubMed1986

Trace analysis of methanol in rat serum by headspace high resolution gas chromatography/selected ion monitoring.

A high resolution headspace gas chromatography/selected ion monitoring analytical method has been developed for the quantitation of methanol in body fluids. The addition of tetradeuterated methanol as internal standard gives this method high accuracy and reproducibility. The high sensitivity of the mass spectrometer permits analysis of methanol in aqueous solutions at concentrations down to 0.012 mg/l. The analytical procedure described was used to measure serum methanol in rats given 5 mg/kg of this alcohol orally. The method proved suitable for analysis of endogenous levels of methanol and of variations close to endogenous levels.

Animals↗