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Biomedical subjects

I Pavan

Publications and source records attributed to I Pavan.

At least 19 recordsLinked to original sources
PubMed1997

Urinary excretion of ethylenethiourea in five volunteers on a controlled diet (multicentric study).

Urinary excretion of ethylenethiourea (ETU) was monitored for 8 days in a group of five male non-smoker volunteers on a diet, the items of which were assayed for ETU and carbon sulphide. Urinary excretion of ETU reflected the consumption of wine, fruit and vegetables. Urinary ETU concentrations ranged from 0.6 to 6.7 micrograms/g creatinine. ETU concentrations in the food eaten by the volunteers were generally below the detection limit whereas in wine 8.8 micrograms/l ETU was detected. Evolution of carbon sulphide by food samples ranged from 0.03 to 0.17 mg/kg. Mean (+/- S.D.) daily intake of ETU in wine was 3.5 +/- 0.2% of the acceptable daily intake (ADI): 0.070 +/- 0.004 micrograms/kg body wt. During the 8 days of the study, an average of 48.3% of the ETU ingested in wine was excreted unmodified by the kidneys. Twenty-four hour urinary excretion of ETU was significantly correlated with daily intake of ETU (r = 0.768) and CS2 evolved by the daily food items (r = 0.414).

Adult↗
PubMed1996

Reference values of urinary ethylenethiourea in four regions of Italy (multicentric study).

The results of a study in which urinary ethylenethiourea (ETU) was assayed in the general population (167 subjects) of four Regions of Italy (Veneto, Lombardy, Piedmont and Trentino Alto Adige) are reported. The results are compared with those in a population of 97 subjects from Rovescala, a hillside wine-producing town a few kilometers from Pavia, where ethylenebisdithiocarbamates are sprayed by helicopter. It was found that an average of 24% of the populations of the four regions, taken together, had urinary ETU levels above detection limits (1.0 microgram 1(-1)) as compared to 37% of the population of Rovescala. The ranges of concentration were 0.8-8.3 micrograms 1(-1) for the four regions and 0.9-61.4 micrograms 1(-1) for Rovescala. Statistically significant variables for urinary ETU levels were smoking and wine drinking.

Adolescent↗
PubMed1993

Determination of anabolic steroid 19-nor-testosterone in bovine serum by GC-SIM-MS.

Anabolic steroids extracted from bovine serum by means of organic solvents or solid-phase extraction techniques with C18 cartridges are not suitable for quantitative analysis by gas chromatography-mass spectrometry (GC-MS); therefore, they were extracted from serum by Extrelut columns (Merck; Germany), eluted with diethyl ether, and purified by a solid-phase extraction technique using amino (NH2) columns. The resulting clean extract was treated with heptafluorobutyric anhydride (HFBA); this formed a derivative suitable for GC-MS analysis. Using selected ion monitoring (SIM), quantities as small as 40 pg/mL can be detected.

Animals↗
PubMed1992

A new case of occupational asthma from reactive dyes with severe anaphylactic response to the specific challenge.

A case of occupational asthma in a wool and cotton dyer handling reactive dyes is described. The patient was skin positive, but asymptomatic to house dust mites. A bromoacrilamidic dye (Lanasol Yellow 4G) has been identified through chamber inhalation challenge as being responsible for the sensitization. A very short (4-minute) exposure produced a severe immediate obstructive ventilatory defect followed by arterial hypotension and urticaria. Bronchial hyperresponsiveness as tested through metacholine challenge was absent both in basal conditions and after the dye challenge. Both prick and patch test for the dye were positive in the absence of any sign of contact dermatitis.

Adult↗
PubMed1992

Monitoring propofol serum levels by rapid and sensitive reversed-phase high-performance liquid chromatography during prolonged sedation in ICU patients.

A quick and sensitive reversed-phase high-performance liquid chromatography (HPLC) method has been developed in order to determine the concentration of Propofol (2,6 diisopropylphenol) in human serum. Propofol can be isolated from serum by adding 0.5 mL precipitating solution. This consists of an acetonitrile and perchloric acid (67:33, v/v) mixture, which also contains dibutylphthalate (2 mg/100 mL) as internal standard. The sample is then mixed for 1 min on a vortex-mixer. The endogenous serum substances precipitated by acetonitrile and perchloric acid are further separated by centrifugation. The supernatant is directly injected into the HPLC system. A 250- x 4.6-mm column, packed with 10-microns Spherisorb reversed-phase octadecylsilane particles (C18), is used for chromatographic separation. The mobile phase consists of an acetonitrile-water mixture (67:33 ratio) with 0.4 mL acetic acid (pH 4). Propofol is monitored by a UV-visible detector at 270 nm and 0.1-0.002 absorbance units full scale (AUFS). The detection limit of Propofol (in human serum) is 0.1 mg/L for a 20-microL injection volume. The time of the assay is less than 20 min, including sample preparation.

Acetonitriles↗
PubMed1991

Clinical, histological, and chemical characterization of ectopic calcification in dialyzed and non-dialyzed patients.

In a review of 11 cases of ectopic calcification (5 of which in dialyzed patients and one in a paraplegic), the authors attempt to characterize this disorder in all its various forms using histological, clinical, and chemical methods. In dialyzed patients, two contributing factors were identified: hyperphosphatemia (plus hypercalcemia) and secondary hyperparathyroidism. In hyperphosphatemic patients the calcifications are multiple, paraarticular, labile, and have a fluid-viscous consistency. In secondary hyperparathyroidism, in addition to the above metastatic calcification there is dystrophic calcification typically localized in the anterior muscles of the hip and thigh. The ectopic calcification of the non-dialyzed patients is true ossification. The precise moment of the onset of the lesion is not always discernable, but its evolution points to primary or secondary local irritation as the trigger. Ossification is the predominant phenomenon in the paraplegic as well, while the triggering mechanism is still unknown.

Adult↗
PubMed1990

Primary oxalosis mimicking hyperparathyroidism diagnosed after long-term hemodialysis.

Primary oxalosis is a rare inborn error of oxalate metabolism. Most cases are discovered in children, but occasionally symptoms begin later in life. Since early deaths in the past were from renal failure, prolonged survival obtained with chronic dialysis allows oxalosis to develop. This paper presents a 38-year-old man with an atypical history of type-I primary hyperoxaluria, not diagnosed until after 5 years of dialysis. Bone biopsy was performed because the biochemical and radiologic features did not seem consistent with a putative diagnosis of secondary hyperparathyroidism. This case emphasizes the clinical heterogeneity of this disorder, and the need for its considerations in the spectrum of dialysis-related bone diseases. It also stresses that bone oxalosis may mimic hyperparathyroidism, especially radiologically. Differential diagnosis is therefore mandatory.

Adult↗
PubMed1989

Heracleum mantegazzianum growth phases and furocoumarin content.

The observation of photocontact dermatitis from Heracleum mantegazzianum Sommier et Levier in 2 gardeners at work prompted the analysis of furocoumarin content of stem, leaves and fruits of the plant during a period of 1 year. Their concentration was found to be maximal in fruit, intermediate in leaf, and minimal in stem. Psoralen was the most prevalent substance in the leaf and bergapten in the fruit. In the stem, in contrast, individual furocoumarins were found in lower but variable concentrations. 3 furocoumarin seasonal peaks were observed in the leaf: the maximal peak occurred in June, the intermediate in August, the minimal in November. This trend corresponds to 3 biological phases of the weed.

5-Methoxypsoralen↗
PubMed1987

Excretion kinetics of the rubber anti-oxidant N-isopropyl-N'-phenyl-p-phenylendiamine (IPPD).

Sixteen rubber vulcanizers using IPPD as anti-oxidant were monitored for the presence of the parent compound in the urine during two consecutive working weeks using HPLC for analysis. At least two components in the excretion kinetics could be demonstrated: a fast one, as end-shift urinary concentrations significantly exceeded before-shift ones, and a less rapid one, as before-shift values at the end of the week significantly differed from those determined at the beginning. A skin absorption experiment was also performed. It demonstrated three components in the excretion kinetics, with apparent half-times of approximately 3, 7 and 24 h. Excretion ceased 7 d after skin exposure.

Adult↗
PubMed1978

[Control of occupational exposure to benzene in a chemical plant].

Later on detection of several cases of acute myelotoxic intoxications the use of benzene as a solvent has been banned in Italy since 1963 (Law n. 245). Its consumption has therefore been confined to synthesys processes in petrolchemical industry. The hazards arising from the operations performed in an open air chemical plant which produces alkylbenzene were monitored by the AA. The synthesis occurs in a closed system which provides opportunities for benzene exposure during filling, control and maintenance operations. Nine environmental samples out of 10 showed benzene concentrations above 10 ppm with peaks up to 110 ppm. Long term air sampling showed values ranging from 12 to 75 ppm. Urinary phenol elimination has been measured showing values above 50 mg/1 for approximately 20% of workmen. The difficulties pertaining to an adequate control of benzene exposure in chemical plants are discussed. Being skin contact a mode of entry of apreciable concern, the AA. stress out that priority in exposure monitoring should be given to biological tests such as urinary phenol level and benzene concentration in expired air measurements.

Air Pollutants↗
PubMedDate not supplied

Reference values of urinary 3,5,6-trichloro-2-pyridinol in the Italian population--validation of analytical method and preliminary results (multicentric study).

The interlaboratory validation of analytical procedures for the assay of urinary 3,5,6-trichloro-2-pyridinol (TCP) in the general Italian population is reported. The determinations were performed by high-resolution gas chromatography (HRGS) with electron capture detection and HRGS with mass spectrometry (MS) in 2 laboratories. The urine samples were from 42 participants from 3 regions of Italy. The results were evaluated by interlaboratory quality control. Urinary TCP concentrations were above the detection limit (1.2 micrograms/L) in 88% of the population, with a mean detectable concentration [GM (GSD)] of 2.8 (1.9) micrograms/g creatinine (creat). (GM, geometric mean; GSD, geometric standard deviation.) The Mann-Whitney U test showed that wine consumption was a statistically significant variable (p < 0.05) for urinary concentrations of TCP. Analysis of variance of the logarithm of urinary TCP versus wine consumption and diet showed a statistically significant fit. The model used explained 30% of the total variance: wine consumption and diet accounted for 37 and 17% respectively of the explained variance.

Adult↗
PubMedDate not supplied

[Polychlorobiphenyls: reference values].

The purpose of this work is to compare the PCB values in blood, serum and adipose tissue of non-exposed people over the last twenty years of scientific literature in order to establish whether the determination of single congeners is better then the evaluation of the total PCB amount moreover an analytical strategy useful to define a reference value for non-exposed Italian population has been evaluated. In the literature very variable results were found for the determination of total PCBs in blood, in serum or adipose tissue. We suggest to determine only the amount of the most toxic congeners of PCBs (28, 52, 77, 101, 118, 126, 138, 153, 169, 180) by using the HRGC/ECD as analytical technique.

Humans↗
PubMedDate not supplied

[Aromatic amines with certain, probable, or possible carcinogenic action: reference values].

The aim of this work is to determine the amount of some aromatic amines in urine of non-exposed people in order to define a reference value. The literature examination has showed that only a small numbers of aromatic amines are usually determined in urine namely: aniline, benzidine, 2-naphtilamine, o-toluidine, 3,3'-dichlorobenzidine, 4-chloro-o-toluidine and 4-chlorobenzidine. On the basis of our experience the analytical method proposed by Lichtenstein is appropriate for obtaining reliable analytical results.

Amines↗
PubMedDate not supplied

[Various air pollutants in Torino].

The trend of concentrations of some pollutants (total particulate, polycyclic aromatic hydrocarbons (PAH), benzo(a)pyrene (BaP), chromium, nickel, lead, vanadium) in the urban air of Turin for the years 1986-87-88 was studied. The air was sampled daily by glass fiber's filters; a ponderal determination of total particulate was made; PAH was dosed by gas-chromatography and by mass spectrometry, metals was determined by atomic absorption spectrometry. These are the values of the three years mean concentration: total particulate 156.3 micrograms/mc, PAH 27.2 ng/mc, B(a)P 2.16 ng/mc, Cr 28.6 ng/mc, Ni 40.5 ng/mc, Pb 1.37 micrograms/mc, V 55.2 ng/mc. Finally, we try to calculate the conjectural carcinogenic effect of the B(a)P for the residents of Turin.

Air Pollutants↗