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Biomedical subjects

E Clonfero

Publications and source records attributed to E Clonfero.

At least 37 records · Page 2Linked to original sources
PubMed1992

Detection of benzo[a]pyrene-diol-epoxide-DNA adducts in white blood cells of psoriatic patients treated with coal tar.

An enzyme-linked immunosorbent assay (ELISA) was used to detect BPDE-DNA adducts in white blood cells of 23 psoriatic patients undergoing clinical coal tar therapy. Ten of these patients were reanalyzed 2-5 months after the end of the coal tar treatments. The results show that the mean adduct level during the treatment period was 0.26 +/- 0.16 fmole BPDE/micrograms DNA (7.7 +/- 4.9 adducts/10(8) nucleotides), while 2-5 months later the mean adduct level had decreased significantly (P less than 0.005) to 0.11 +/- 0.08 fmole BPDE/micrograms DNA (3.3 +/- 2.4 adducts/10(8) nucleotides). No relationship could be ascertained between the level of exposure and the amount of BPDE-DNA adducts. In addition, no difference in the level of DNA adducts was found between smoking and non-smoking patients.

Adult↗
PubMed1992

Mutagens in urban air particulate.

Extracts of airborne particulate matter were demonstrated to be mutagenic in the Salmonella/microsome test. Urban airborne particulate was collected with high-volume samplers in an Italian town mainly polluted by traffic exhaust fumes. After being weighted for determination of total dust, the particulate was extracted with CH2Cl2/methanol and assayed by Salmonella/microsome assay on strains TA98, TA100 and TA98NR. All samples were mutagenic on strain TA98, with a mutagenic potency of 50 +/- 14 (-S9), 128 +/- 63 (+S9) and 104 +/- 51 (-S9), 211 +/- 97 (+S9) revertants/mg of particulate for summer (n = 23) and winter (n = 22) determinations, respectively. The mutagenic activity on strain TA98NR was about one-half that on strain TA98, indicating a large contribution of nitroaromatic mutagenic compounds. Mutagens from airborne particulate were less active on strain TA100. The summer and winter mean values of urban total dust were 0.15 +/- 0.07 and 0.35 +/- 0.18 mg/m3 respectively, and the mutagenicity of urban air on strain TA98 was 8 +/- 5 (-S9), 22 +/- 17 (+S9) and 30 +/- 11 (-S9), 61 +/- 21 (+S9) revertants/m3 in the two seasons, respectively. In winter, besides an increase in urban air mutagenicity, there also was a change in direct particulate activity per milligram, which was double that of summer.

Air Pollutants↗
PubMed1991

The mutagenic activity and polycyclic aromatic hydrocarbon content of mineral oils.

Naphthenic distillates (raw or acid-treated) and motor and emulsifiable aluminium rolling oils were tested for mutagenicity in the Salmonella/microsome assay using the TA98 and TA100 strains. The polycyclic aromatic hydrocarbon (PAH) content of oil samples was also determined in parallel. In the presence of metabolic activation, both untreated and acid-treated naphthenic distillates were found to be mutagenic on a modified Ames test. One untreated sample showed the highest value of mutagenic potency (50 net revertants/mg oil for strain TA98). The PAH content of naphthenic distillates was about 10% (w/w) and was slightly reduced by sulfuric acid/earth treatment (1%). Non-mutagenic paraffin- and solvent-extracted crankcase oils became active, both with and without enzyme activation, after long use as gasoline engine lubricants, whereby their PAH content doubled (from 1.5% to 3%, w/w). A refined emulsifiable mineral oil also became directly mutagenic in both Salmonella strains after prolonged use in an aluminium hot-rolling mill. As the PAH levels found in used rolling oils was very low, we cannot explain their mutagenic activity. Mutagenicity was greatly reduced following careful cleaning of the oil bath and of the entire rolling machine. The present data reveal both the potential risk of occupational exposure to unrefined or mildly treated oils and the formation of mutagens in highly refined oils if the latter are used at high temperatures. The formation of mutagens in oils used in the metal-working industry can be prevented by careful industrial hygiene measures.

Humans↗
PubMed1990

Biological monitoring of human exposure to coal tar. Urinary mutagenicity assays and analytical determination of polycyclic aromatic hydrocarbon metabolites in urine.

The mutagenicity of urine extracts from anode plant workers exposed to coal tar pitch volatiles and non-smoking psoriatic patients treated with coal tar applications and UV light (Goeckermann regimen), was determined by the plate incorporation assay and the fluctuation test employing Salmonella typhimurium strain TA98 in the presence of rat liver post-mitochondrial fractions and deconjugating enzymes. The levels of total polycyclic aromatic hydrocarbons (PAHs) and of a marker metabolite of pyrene (1-hydroxypyrene) were determined in the urine of the same subjects. Both the occupational and in particular the therapeutic exposure to coal tar resulted in clear increases in urinary levels of PAH metabolites as compared to unexposed subjects. The level of 1-hydroxypyrene in the urine samples was comparable to or even greater than the corresponding level of total PAHs, indicating a poor recovery of PAH metabolites for this method. Following treatment with coal tar, most of the psoriatic patients excreted clearly increased levels of mutagens in their urine, while non-smoking anode plant workers showed no increase in urinary mutagenicity. The minimum levels of PAH metabolites corresponding to a significant increase in urinary mutagenicity varied from sample to sample, presumably depending on interfering factors present in different amounts in the extracts. Nonetheless the urine samples which were clearly mutagenic presented elevated levels of PAH metabolites, suggesting that the mutagenicity assays lack sufficient sensitivity to allow their application in the biological monitoring of most occupational exposures to coal tar.

Coal Tar↗
PubMed1989

Biological monitoring of human exposure to coal tar. Urinary excretion of total polycyclic aromatic hydrocarbons, 1-hydroxypyrene and mutagens in psoriatic patients.

Three methods for the biological monitoring of human exposure to coal tar were compared. Levels of 1-hydroxypyrene(1-OH PYR), polycyclic aromatic hydrocarbons (PAH) and mutagens (Ames plate incorporation assay using Salmonella typhimurium strain TA98 in the presence of S9 and beta-glucuronidase) were determined in urinary samples from psoriatic patients undergoing topical treatment with mineral coal tar. A single sample of urine with a high content of PAH was diluted with urine of nonexposed, non-smoking subjects in order to obtain nine samples with a decreasing content of PAh metabolites. Mutagenicity of the extracts was detectable down to the dilution corresponding to a content in 1-OH PYR of about 50 micrograms/g creatinine and total PAH of 7 micrograms/g creatinine. In a second phase the three indicators of exposure to PAH were compared in 16 urinary samples from four psoriatic patients. The total PAH levels determined by the acidic deconjugation/reduction method were confirmed to be nearly always lower than the corresponding levels of 1-OH PYR alone. Most of the extracts were mutagenic, however, some of the samples with a high content in PAh metabolites were not mutagenic. In all the urinary samples analyzed the excretion of 1-OH PYR was markedly greater than in control subjects. 1-OH PYR and urinary mutagenicity levels were well correlated. The present data suggest that both the determination of mutagenicity and 1-OH PYR in urine may be used to monitor occupational exposure to PAH, the latter method being cheaper and of greater specificity and sensitivity.

Coal Tar↗
PubMed1989

Release of mutagens from finished leather.

Extracts of a leather widely used in the furniture and dress-making industries were tested for their mutagenic activity in the Salmonella/microsome assay. Extracts obtained after vigorous treatment of leather samples in a Soxhlet apparatus with toluene or ethanol were mutagenic in strain TA98 of S. typhimurium in the absence of S9 mix. The analysis of extracts of leather at various intermediate stages of processing showed that the mutagenic activity appeared after the coloration process. The responsible compound was identified to be an azo dye (Color Index: Acid Brown 83) whose mutagenic potency was about 4 revertants/micrograms.

Azo Compounds↗
PubMed1989

Induction of SOS response in Escherichia coli strain PQ37 by 16 chemical compounds and human urine extracts.

The SOS Chromotest on Escherichia coli strain PQ37 was used to detect DNA damage induced by 16 chemical compounds and urine samples from smokers and a non-smoking psoriatic patient treated with mineral coal tar. The results confirmed the strong SOS inducing activity of 2-aminoanthracene and benzo[a]pyrene with metabolic activation and N-methyl-N'-nitro-N-nitrosoguanidine, mitomycin C and 4-nitroquinoline-N-oxide without metabolic activation. A weaker response in the absence of microsomal enzymes was observed with hydroxyurea (only at high doses) and the soluble Cr(VI) compounds potassium chromate and potassium dichromate. No effect was observed with ampicillin, cadmium chloride, cyclophosphamide, griseofulvin, the insoluble Cr(VI) compound lead chromate, the soluble Cr(III) compounds chromium nitrate, chromium chloride, chromium potassium sulphate, and the chelating agent sodium nitrilotriacetate. Among the Cr(III) compounds only chromium acetate produced a low but significant increase of SOS inducing activity. Solubilization by nitrilotriacetate of genotoxic Cr(VI) from insoluble lead chromate was observed, whereas no interaction occurred between nitrilotriacetate and the soluble Cr(VI) and Cr(III) compounds. Using urinary XAD-2 extracts, we found the SOS Chromotest poorly sensitive to the mutagens present in urine from tobacco smokers which, on the other hand, were detected by the gene mutation assay in Salmonella typhimurium (Ames test). A urine sample obtained from a psoriatic patient, therapeutically treated with mineral coal tar, had a significant SOS inducing activity with and even without metabolic activation, whereas in the Ames test it was active only in the presence of metabolic activation.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1987

Sister chromatid exchanges and DNA repair capability in sanitary workers exposed to ethylene oxide: evaluation of the dose-effect relationship.

Determination of ethylene oxide (EtO) in the working environment and induction of sister chromatid exchanges (SCE) and unscheduled DNA synthesis (UDS) in peripheral lymphocytes of 10 exposed sanitary workers and 10 control subjects matched for sex, age, and smoking habits are reported. The relationship between the external dose of EtO and the frequency of SCE was determined in the above group and in a group of 41 sanitary workers previously studied. The 10 newly examined workers were exposed to EtO concentrations (1.84 ppm as time-weighted average) intermediate between the high (10.7 ppm) and low (0.35 ppm) levels of exposure of the two previously examined groups (19 and 22 workers, respectively). A statistically significant (p less than 0.002) increase of SCE frequency was observed between the present control and exposed groups. The inducibility of unscheduled DNA synthesis by gamma rays was lower in the lymphocytes of the exposed workers than in controls, but the difference was not statistically significant. A significant relationship between the frequency of SCE and the level of EtO exposure for the three exposed groups was demonstrated by two different statistical methods. It is suggested that the present Italian threshold limit value for EtO (3 ppm) may not protect the exposed workers against possible genotoxic effects and that even a chronic exposure to 1 ppm may not be devoid of genotoxic risk.

Chromosome Aberrations↗
PubMed1987

Mutagenic activity of carbon black dyes used in the leather industry.

Seven carbon black pastes used as commercial leather dyes were tested for their mutagenicity in the Salmonella/microsome test (TA98 and TA100 strains). All the samples assayed either directly or after extraction with a 30-min sonication in benzene were devoid of mutagenicity both in the presence and absence of a metabolic activation preparation. After a 48-h extraction with boiling toluene in a Soxhlet apparatus, four samples were mutagenic in TA98 strain in the presence of S9 mix. The activity ranged from 1.3 to 9.6 induced revertants/mg equivalent of extract. A weak direct mutagenic activity in strain TA98 was shown by one extract. Polycyclic aromatic hydrocarbons (PAH) were determined in the toluene extracts by high resolution gas chromatography/mass spectrometry. The presence of PAH could explain the mutagenicity of only one sample (8.79 micrograms of total PAH/100 mg equivalents of extract), while low or undetectable levels of PAH were found in the other mutagenic extracts. The mutagenic activity was evident only after a vigorous extraction process, thus a low bioavailability of the mutagens present in these compounds is suggested.

Benzene↗
PubMed1986

Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of humans exposed to therapeutical coal tar.

The urinary mutagenicity and the excretion of polycyclic aromatic hydrocarbons (PAH) in three non-smoking male patients, treated for psoriasis with cutaneous applications of crude coal tar, were analysed. Mutagenicity of the urinary extracts was measured by the plate incorporation assay using Salmonella typhimurium strains TA 98 and TA 100 in the presence of liver S9 fraction from Aroclor-induced rats with or without beta-glucuronidase. After concentration, hydrolysis and reduction of the urine sample, PAH levels were measured by high resolution gas chromatography/mass spectrometry. Following cutaneous treatment with coal tar, the urine of all three subjects showed noticeable levels of PAH and/or metabolites and marked mutagenicity both on strain TA 98 and TA 100 in the presence of S9 fraction. The addition of beta-glucuronidase increased the mutagenicity of the urinary extracts, the maximum values being attained on strain TA 100 in the presence of both microsomal fraction and deconjugating enzymes. The mutagenicity of urinary extracts from subjects treated therapeutically with crude coal tar was correlated (r = 0.788, P less than 0.01) with the total PAH levels in their urine. The PAH excreted in urine were mainly low molecular weight compounds, while benzo[a]anthracene was present in scarce amounts and the excretion of benzo[a]pyrene did not increase following the cutaneous exposure to the crude coal tar.

Coal Tar↗
PubMed1985

Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of workers exposed to coal tar pitch volatiles in an anode plant.

The mutagenicity of urinary extracts and the excretion of PAH from workers occupationally exposed to coal tar pitch volatiles in an anode plant were analyzed. Mutagenicity of the urinary extracts was measured by means of the plate test using S. typhimurium strain TA 98. After concentration, hydrolysis and reduction of the urine samples, PAH levels were measured by high resolution gas chromatography/mass spectrometry. No significant difference was found in the mutagenicity of the urinary extracts of non-smokers occupationally exposed to PAH as compared with the controls. Low PAH concentrations were found in the urine of the exposed subjects, which lends further support to the negative results obtained with the Ames' test. The increase of urinary PAH excretion, in relation to occupational exposure, was mainly due to the less mutagenic, low molecular weight compounds.

Air Pollutants, Occupational↗
PubMed1978

[Risk of absorption of fluoride in electrode arc welding].

The AA. in order to investigate the risk of fluoride absorption examined two factories in which arc-welding electrodes were used. They measured: a) fluoride content in two most used electrodes; b) airborne fluoride concentrations and dustness in the presumed respiratory area of welders with or without fume and dust capture devices; d) airborne fluoride concentrations and dustness three meters away from the welding place during unprotected work with basic electrodes; e) concentrations of fluoride in urine during a workweek in welders (n = 63) and in a control group (n. = 25). The AA. conclude that, in spite of the high teoretical risk of breathing fluoride, the intake of this compound is very low if welders are protected by easy devices.

Air Pollutants↗
PubMed1978

[Industrial hygiene and improvement of the work environment].

The AA. report a series of practical experiments in the following industries: textiles, ceramics, graphics and heavy industry, in order to demonstrate the necessity and utility of industrial hygiene in which an occupational hazard is not simply identified, but rather an improvement of the work environment is undertaken and the results of such a programme are again controlled and evaluated. The data presented lend themselves to a discussion of a preventive nature since, from a comparison of the data before and after modification, the efficacy of the modification itself is evaluated. The efficacy may vary from simple maintenance of equipment to environmental purification procedures and necessity of applying corrective modifications directly by the raw materials.

Air Pollutants, Occupational↗
PubMedDate not supplied

Polyaromatic hydrocarbons administered in humans by dermal route increase total IgE.

Inhalation of polyaromatic hydrocarbons (PAHs) extracted from diesel exhaust particles (DEP) enhances local (nasal) production of IgE in humans. The aim of the present research is to investigate whether in humans dermal exposure to PAHs which are not extracted from DEPs increases serum IgE, and whether host factors modify the immunologic effect. In thirty-two patients with acute psoriatic lesions, a cream containing 3% of coal tar (which holds a variety of PAHs) was applied to the skin for 24 hours. Serum IgE were measured before (IgE0) and four (IgE4) and eight (IgE8) days after application. Replicated means were compared by analysis of variance for repeated measures and by the Newman-Keuls' test. IgE0, IgE4 and IgE8 were 151.19, 159.69 (a 6% excess) and 170.90 kU/L (a 13% excess) respectively; pairwise comparison showed IgE8 was significantly higher than IgE0 (p<0.05). At multiple linear regression analysis, the percentage increase in serum IgE across observation days was the dependent variable against age, sex, cigarettes/day, urinary 1-pyrenol, atopy, skin area treated, and grams of cream. Of the independent variables, only age had a significant (p<0.028) influence: the younger the age, the higher the IgE response to PAHs. We conclude that whatever the source and the route of entry (skin or respiratory tract), PAHs increase total serum IgE, mainly in younger age groups.

Administration, Cutaneous↗
PubMedDate not supplied

[Effect of atmospheric pollution on respiratory function in children from Venice (author's transl)].

The respiratory function has been compared in two standard school populations. A sample, of 700 children from the industrial quarters of Venice (highly polluted) and 350 children from the Historic Center (not polluted), has been subjected to a respiratory questionnaire, clinical investigation and plethysmographic functional testing with measurement of airways resistance by the panting method. The changes in the airways resistance were related to the residing area and to the bronchitic episodes in the past, while the family's socio-economic situation and the living area did not play any role.

Air Pollution↗