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Biomedical subjects

R Pasquini

Publications and source records attributed to R Pasquini.

At least 73 records · Page 4Linked to original sources

Disseminated Fusarium sp. infection affecting the brain of a child after bone marrow transplantation.

A case of Fusarium sp. infection of the brain in a 6-year-old child who underwent allogeneic BMT is reported. As far as the authors know, this is the first report of Fusarium sp. encephalitis in a BMT patient. Fusarium sp. infection is a rare but emerging fungal pathogen after BMT and, because of several similarities, it is often mistaken for other mold infections, such as Aspergillus sp. The importance of early identification of this fungus as a cause of disseminated fungal infection in BMT patients, and some new modalities of Fusarium sp disseminated infection treatment are discussed here.

Bone Marrow Transplantation↗

Cytogenetic biomonitoring of pesticide-exposed farmers in central Italy.

The frequency of sister chromatid exchanges (SCE) and micronuclei in peripheral blood lymphocytes was evaluated in 48 agricultural workers and 50 control subjects living in central Italy. No difference in SCE frequency was found between the control and the exposed populations with respect to age, smoking habits, and duration of exposure, although smokers, both farmers and controls, had a higher SCE frequency than nonsmokers. However, the comparison of proliferative rate index values found in the two groups revealed a significant decrease in the activation capability of lymphocytes in the pesticide-exposed workers, probably related to the toxic properties of chemicals to which the farmers were exposed. On the contrary, the analysis of micronuclei frequency indicated that there were differences between the exposed and control subjects with respect to smoking habits, age, and duration of exposure. Our results indicate that, in the study population occupationally exposed to a complex mixture, including insecticides, fungicides, and herbicides, there is clear, although slight, evidence of clastogenic activity in peripheral blood lymphocytes but no corresponding effects on SCE induction. Moreover, our data show clear evidence of cell proliferation delay relatable to chemical compounds used in agriculture.

Adult↗

Bone marrow transplantation for Fanconi anemia.

Fanconi anemia is a genetic disorder associated with diverse congenital abnormalities, progressive bone marrow failure, and increased risk of leukemia and other cancers. Affected persons often die before 30 years of age. Bone marrow transplantation is an effective treatment, but there are few data regarding factors associated with transplant outcome. We analyzed outcomes of HLA-identical sibling (N = 151) or alternative related or unrelated donor (N = 48) bone marrow transplants for Fanconi anemia performed between 1978 and 1994 and reported to the International Bone Marrow Transplant Registry. Fanconi anemia was documented by cytogenetic studies in all cases. Patient, disease, and treatment factors associated with survival were determined using Cox proportional hazards regression. Two-year probabilities (95% confidence interval) of survival were 66% (58% to 73%) after HLA-identical siblings transplants and 29% (18% to 43%) after alternative donor transplants. Younger patient age (P .0001), higher pretransplant platelet counts (P = .04), use of antithymocyte globulin (P = .005), and use of low-dose (15 to 25 mg/kg) cyclophosphamide plus limited field irradiation (P = .009) for pretransplant conditioning and cyclosporine for graft-versus-host disease prophylaxis (P = .002) were associated with increased survival. Bone marrow transplants are effective therapy for Fanconi anemia. The adverse impact of increasing age and lower pretransplant platelet count on transplant outcome favors earlier intervention, especially when there is an HLA-identical sibling donor.

Adolescent↗

Periodontal files--a comparative study.

Periodontal files are used by many dentists for instrumentation of root surfaces as a part of periodontal treatment. The purposes of this study were: 1) to examine, evaluate, and compare several periodontal files in 3 different conditions: new, used, and used/sharpened and 2) to evaluate the efficacy of 5 sharpening devices. The main characteristics observed included: the number, shape, and interval of blades; the active, rake, and lip angles; changes induced by wear; the influence of sharpening; and the type of metal surfaces comprising the blades. There was a wide range of active angles on each individual file, from a high of 75 degrees to a low of 51 degrees. The range of active angles for all blades on all new files was even greater, from a high of 87 degrees to a low of 30 degrees. Wear, observed on some but not all blades, was not extensive and appeared either as abrasion or, occasionally, as fracture of the blade edge. Sharpness scores (5 = sharpest and 1 = dullest) for new file blades were also extremely variable and spanned the full range of values, with a majority of blades scoring 3.5 and below. Attempts to sharpen files with several devices produced inconsistent results. All 5 sharpening devices had significant shortcomings. It was concluded that the extreme ranges both in active angles and in sharpness scores probably have a significant influence on effectiveness of root instrumentation.

Dental Instruments↗

[Not Available].

The quality of drinking water is known to have positive or negative influences on human health. At present, in the industrialized countries microbiological contaminants in public water supplies are under control, due to the widespread introduction of effective disinfection and potabilization systems. However, of special interest are other public health problems linked with the presence of many water components or contaminants. Since the beginning of this century, fluoride showed to have beneficial effects on dental caries and the practice of adding fluoride to drinking water has been widely followed in many countries for reduction of dental caries. More recently, a large body of scientific information indicates that various characteristics related to water hardness are correlated with incidence of cardiovascular disease. Moreover, the discovery of the presence in drinking water of inorganic and organic contaminants with mutagenic/carcinogenic properties gives rise to public health concern.

Beverages↗

Studies on hepatic xenobiotic-metabolizing enzymes in rats treated with insecticide deltamethrin.

The effects of the synthetic dibromo-pyrethroid insecticide deltamethrin on some hepatic phase I and II enzyme activities were studied in rat liver. The animals were treated with daily doses of 5 and 10 mg/kg of both pure insecticide or its commercial formulation (Decis), administered i.p. in corn oil for 7 days. The following enzyme activities were studied: NADPH-cytochrome-P450 reductase, aryl-hydrocarbon hydroxylase, aminopyrine N-demethylase, glutamyl cysteine synthetase, glutathione S-transferase, glutathione peroxidase, peroxisomal acyl-CoA oxidase, catalase, and urate oxidase. Both deltamethrin and its commercial formulation were effective in modifying the activities of several of these hepatic xenobiotic-metabolizing enzymes. However, some differences in enzyme modifications were found between treatment with pure or commercial deltamethrin, the latter being more active. This effect could be ascribed to additives, solvents, and chemical intermediates present in the Decis formulation. These results suggest that exposure to this deltamethrin commercial formulation could be more dangerous than exposure to deltamethrin alone, both in terms of its hepatotoxicity and/or alterations in the hepatic biotransformation of other occupational/environmental xenobiotics.

Aminopyrine N-Demethylase↗

Studies of migration of potentially genotoxic compounds into water stored in pet bottles.

Coloured polyethylene terephthalate (PET) bottles for carbonated beverages were studied for potential migration of genotoxic compounds. A combined approach, using physicochemical methods and a bacterial short-term mutagenicity test (Ames test) was followed. Standard EEC and US FDA tests for total migration of non-volatile migrant compounds into distilled water were performed, together with modified tests, where freeze-drying instead of evaporation of water was used, in order to measure both volatile and non-volatile chemicals. Gas chromatography-mass spectrometry (GC-MS) analysis was performed on these residues. PET bottles filled with naturally carbonated mineral water were also used for long-term total organic carbon (TOC) and mutagenicity migration studies (up to 6 months' storage). Total migration results for PET bottles were within the EEC and US FDA limits. The use of freeze-drying for the elimination of water enabled much higher total migration data (higher than the limits) to be revealed. Some potentially genotoxic compounds (acetaldehyde, dimethyl terephthalate, terephthalic acid) were identified in these migrant compounds by GC-MS analysis. The tests for TOC migration gave a maximum value after 2 wk storage and the mutagenicity tests on non-volatile migrant compounds gave always negative results.

Carbon↗

In vivo studies on enzymatic induction activity of Linuron.

The effect of the ureic herbicide Linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea] on the levels of some hepatic xenobiotic metabolizing enzymes was studied in rats. The cytochrome P450-dependent monooxigenase activities of aryl hydrocarbon hydroxylase (AHH) and of aminopyrine N-demethylase (APD) were measured in rat livers after a 14-d treatment by gavage with Linuron. AHH was employed as a marker of the catalytic activity of P450IA1 and APD as a marker of the catalytic activity of P450IIB1/2. Furthermore, the enzymatic activities of the cytosolic via glutathione detoxifying enzymes glutathione peroxidase and glutathione S-transferase were assessed. Three doses of Linuron (both as pure compound and as commercial preparation) were tested. The doses tested were 150, 300, and 450 mg/kg body weight for the pure compound and 315.8, 631.6, and 947.4 mg/kg for the commercial preparation. Differences were found in the relative liver weight only in rats treated with the commercial formulation. The aryl hydrocarbon hydroxylase activity was increased with all the tested doses of pure and commercial Linuron. A reduction in the aminopyrine N-demethylase activity was noted for the highest dose of pure Linuron, whereas an increment in this activity was observed for all the doses of the commercial preparation tested. The activity of glutathione peroxidase was not affected by treatment with the pure product; however, an increment in activity was observed at all the tested doses of the commercial preparation. The glutathione S-transferase activity was reduced in both cases.

Aminopyrine N-Demethylase↗

Genotoxicity analysis of N,N-dimethylaniline and N,N-dimethyl-p-toluidine.

N,N-Dimethylaniline (DMA, CAS No. 121-69-7) and N,N-dimethyl-p-toluidine (DMPT, CAS No. 99-97-8) belong to the N-dialkylaminoaromatics, a chemical class structurally alerting to DNA reactivity. Their applications may be industrial (dye and pesticide intermediates, polymerizing agents) and surgical (polymerization accelerators for the manufacture of bone cements and prosthetic devices), thus implying heterogeneous types of human exposure. Findings of carcinogenicity in rodents and some nonexhaustive genotoxicity data are available for DMA, but to our knowledge no information is available on DMPT concerning either carcinogenicity or any kind of genetic toxicity. To investigate their mechanism of action and mutagenic/carcinogenic potential, DMA and DMPT were analyzed for complementary genotoxicity endpoints, namely, gene mutation in Salmonella (Ames test), structural and numerical chromosome aberrations in hamster V79 cells (micronucleus test, matched with an immunofluorescent staining for kinetochore proteins), and in vivo DNA damage in mouse and rat liver (alkaline DNA elution test). The results essentially indicate that both chemicals are chromosome damaging agents. Indeed, at the maximum nontoxic doses, they proved nonmutagenic in Salmonella (although their toxicity did not allow concentrations > 70 micrograms/plate to be tested) and weakly positive in inducing DNA damage (increases in DNA elution rates at most approximately 2.4 times control value). Conversely, they proved clearly positive in inducing numerical chromosome alterations, with dose-dependent increases up to more than five times the control value for DMPT. At the highest dose tested, both chemicals also showed a significant clastogenic effect.

Aneuploidy↗

Monitoring nitrite, N-nitrosodiethanolamine, and mutagenicity in cutting fluids used in the metal industry.

We carried out an integrated environmental/biological monitoring program to evaluate cancer hazards among metal industry workers exposed to cutting fluids. Several cutting fluids were sampled according to response to a semiquantitative nitrite rapid test in metal factories in central Italy. The nitrite-positive samples were analyzed for nitrite and nitrosodiethanolamine (NDELA) content and mutagenic activity. The nitrite-negative samples were analyzed only for mutagenicity. Of the total samples, 20.6% were nitrite positive, and all contained NDELA. However, nitrite content was not quantitatively predictive of the NDELA content, which varied enormously among samples (0.3-1900 mg/kg). Nitrite-negative samples were always nonmutagenic. Mutagenicity was found in half the NDELA-containing samples but was not related to nitrite or NDELA content. Nitrite screening of cutting fluids in the field is an interesting method for identifying samples that potentially contain NDELA and other unknown mutagens and, when performed with short-term mutagenicity tests, nitrite screening seems to be a valid tool by which industrial managers and health officers could minimize the health hazards associated with occupational exposure to cutting fluids.

Diethylnitrosamine↗

[The growth of the low-birth-weight neonate: assessment at 3 years].

Follow-up studies of low-birth-weight (LBW) neonates have shown a high incidence of growth failure in the first years of life. We evaluated the growth attainment (weight, length and head circumference) in 182 LBW neonates discharged from our Intensive Care Unit between 1982-84 and included in a 3 years follow-up program. The aim of the study is to analyze the correlation between gestational age (GA) and subsequent growth failure. Neonates included in the study were divided in 4 groups (G) according to GA: I G < or = 30 weeks GA; II G = 31-33 weeks GA; III G = 34-36 weeks GA; IV G > or = 37 weeks of gestational age. Growth was evaluated at 40 weeks GA on the basis of Lubchenco and Battaglia centiles, and thereafter at 12, 24 and 36 months according to Scalamandrè greeds. Subnormal weight (< 10 degrees centile) was still evident at 3 years of age in 16.7% of the most premature babies (group I), in 6.2% of babies born between 31 and 33 weeks GA (group II), in 7.1% of babies in group III and in 16.6% of LBW babies born at term of gestation (group IV). Length measurements were satisfactory in PT babies as none of them showed a length < 10 degrees centile by 24 months of age. On the contrary, in the term LBW neonates group 15.6% of babies still showed subnormal length at 3 years of age. Head circumference remained < 10 degrees centile in 16.6% in the I group, in 6.2% in the II group, 21% in the III group and 30% in the IV group.(ABSTRACT TRUNCATED AT 250 WORDS)

Anthropometry↗

Genotoxicity of N-acryloyl-N'-phenylpiperazine, a redox activator for acrylic resin polymerization.

N-Acryloyl-N'-phenylpiperazine is a promoter of redox reactions synthesized recently, and proposed as an activator for the polymerization of acrylic resins for biomedical use. The chemical was analyzed for different genotoxicity endpoints, to obtain both information on its possible mutagenic/carcinogenic potential and a model analysis of a tertiary arylamine, which belongs to a class of chemicals commonly used as polymerization accelerators in the biomaterial field. The genotoxicity endpoints considered were: gene mutation in the Salmonella test; structural and numerical chromosome alterations in Chinese hamster V79 cells, evaluated by the micronucleus test together with an immunofluorescent staining specific for kinetochore proteins; in vitro and in vivo DNA damage, evaluated in V79 cells and in mouse liver by the alkaline DNA elution technique. On the whole, the results indicate that N-acryloyl-N'-phenylpiperazine is to be regarded not so much as a DNA-damaging agent, but as a genomic mutagen. Indeed, it was not mutagenic in Salmonella (though its toxicity did not allow testing concentrations over 70 micrograms/plate), and it was weakly positive in inducing chromosomal fragmentation in vitro (one positive, not dose-related, result out of five different doses tested) and in vivo DNA damage (increases in DNA elution rate never doubling control values). The chemical was, however, clearly positive (with dose-dependent effects up to about 25 times the control value) in causing numerical chromosome alterations, at the maximal non-toxic doses.

Acrylic Resins↗

In vitro genotoxicity of dimethyl terephthalate.

Dimethyl terephthalate (DMTP), the para configuration of dimethyl phthalate, is one of the basic monomers used in the synthesis of polyethylene terephthalate (PET) plastics. Human exposure to DMTP may primarily occur during the manufacture of PET fibers and films. The mutagenic potential of dimethyl terephthalate was evaluated using a battery of in vitro short-term tests: the Ames test; DNA single-strand break assays in CO60 cells and in primary rat hepatocytes; UDS in HeLa cells; chromosome aberration and micronucleus assays in human peripheral blood lymphocytes; selective DNA amplification in CO60 and in Syrian hamster embryo cells. The results of this battery of in vitro assays clearly show that DMTP is nongenotoxic. By contrast, other authors have found DMTP to be an in vivo clastogenic compound and suggested that the mechanisms involved in these in vivo effects seem to have nothing in common with genotoxicity and are still unknown.

Adult↗

Urine mutagenicity and biochemical parameters as markers of exposure to petroleum pitch using a rat model.

A petroleum pitch sample collected in a carbon electrode factory was studied using a series of in vivo assays for genotoxicity and enzymatic induction capability. Rats were treated with the petroleum derivative in three doses: 100, 50, and 10 mg/kg body weight. The treatment produced a rapid excretion of mutagenic substances in the urines of the first 24 hr only in rats treated with high doses (100 and 50 mg/kg). No faecal mutagenic activity was observed. Analyses of urinary thioethers showed that urinary metabolites derived from the compounds present in the pitch-sample at the lowest dose-administered (10 mg/kg) were eliminated primarily as cysteine conjugates. The pitch sample was found to be a good inducer of pulmonary and hepatic aryl hydrocarbon hydroxylase, especially after a 50 mg/kg dose. Urinary D-glucaric acid content was always statistically increased in treated animals compared with controls, confirming the enzymatic induction activity. Hepatic glutathione-S-transferase activity increased following treatment with 50 and 10 mg/kg doses.

Animals↗

Leaching of mutagens into mineral water from polyethyleneterephthalate bottles.

Polyethyleneterephthalate (PET) was tested as a source of mutagen contamination from bottles used for beverage packaging. PET bottles were filled with mineral water and stored in daylight and in the dark for different periods of time. The water samples were concentrated and the concentrates (non-volatile compounds) tested for mutagenicity with the Ames test (static tests). Total organic carbon (TOC) leaching was determined concurrently. Leaching of mutagens was also studied using dynamic tests; shaking distilled water in PET bottles. New methods were also used to test the leaching potential of both volatile and non-volatile compounds: directly testing the mutagenicity in unconcentrated water stored in PET bottles and growing Salmonella strains directly in the plastic bottles. The results were positive only for the static test, which identified leaching of mutagens after 1 month of storage in PET bottles. This activity was higher after storage in daylight.

Food Contamination↗

Thioethers, mutagens, and D-glucaric acid in urine of operating room personnel exposed to anesthetics.

Mutagenic hazards related to occupational exposure to nitrous oxide and enflurane was studied in the personnel of five operating rooms using a coupled environmental and biological monitoring approach. The environmental monitoring revealed air concentrations of the two anesthetics exceedings the TLVs by 10-15-fold. These values were correlated individually with the concentrations of the two anesthetics in the expired air of the exposed subjects. The biological monitoring was carried out by determining two parameters associated with mutagen exposure (urinary mutagenicity and thioethers) and a parameter associated with the enzymatic induction (D-glucaric acid) in the urine of exposed and unexposed subjects (N = 64 and N = 37, respectively). The results showed no difference in the two groups for urine mutagenicity and D-glucaric acid, but urine thioethers were significantly increased among highly exposed subjects.

Adult↗

Urinary excretion of mutagens, thioethers and D-glucaric acid in workers exposed to bitumen fumes.

The authors carried out biological monitoring of the mutagenic/carcinogenic hazards associated with exposure to bitumen fumes during paving operations, analysing some biological parameters in the urine of a group of exposed workers. The urine samples were studied for mutagenicity by the Ames test and for thioethers concentration. D-Glucaric acid urine excretion was also determined to investigate the enzymatic induction potential of bitumens. Even though, in a previous environmental monitoring phase, a low content of mutagenic/carcinogenic compounds was found in bitumen and air samples, urinary mutagenicity data of exposed workers were statistically higher than those of a group of unexposed subjects. The urinary mutagenicity increased further if exposure to bitumens was associated with cigarette smoking. Thioethers were higher only in subjects exposed simultaneously to bitumens and cigarettes. D-Glucaric acid excretion did not increase significantly. The authors think that this type of coupled environmental and biological monitoring is a valid tool for a better evaluation of the mutagenic/carcinogenic exposure to bitumens or similar complex mixtures.

Air Pollutants, Occupational↗