ABSTRACT
We hypothesised that exposure to workplace aerosols may lead to lung function impairment among cement production workers.Our study included 4966 workers in 24 cement production plants. Based on 6111 thoracic aerosol samples and information from questionnaires we estimated arithmetic mean exposure levels by plant and job type. Dynamic lung volumes were assessed by repeated spirometry testing during a mean follow-up time of 3.5â years (range 0.7-4.6â years). The outcomes considered were yearly change of dynamic lung volumes divided by the standing height squared or percentage of predicted values. Statistical modelling was performed using mixed model regression. Individual exposure was classified into quintile levels limited at 0.09, 0.89, 1.56, 2.25, 3.36, and 14.6â mg·m(-3), using the lowest quintile as the reference. Employees that worked in administration were included as a second comparison group.Exposure was associated with a reduction in forced expiratory volume in 1â s (FEV1), forced expiratory volume in 6â s and forced vital capacity. For FEV1 % predicted a yearly excess decline of 0.84 percentage points was found in the highest exposure quintile compared with the lowest.Exposure at the higher levels found in this study may lead to a decline in dynamic lung volumes. Exposure reduction is therefore warranted.
Subject(s)
Construction Materials , Dust , Lung Diseases/etiology , Lung/physiopathology , Occupational Diseases/diagnosis , Occupational Diseases/etiology , Adult , Aerosols , Female , Forced Expiratory Volume , Humans , Inhalation Exposure , Longitudinal Studies , Lung Diseases/physiopathology , Male , Middle Aged , Models, Statistical , Occupational Exposure , Regression Analysis , Spirometry , Surveys and Questionnaires , Vital CapacityABSTRACT
Trypoxylon is a genus of solitary crabronid wasps whose population genetics is poorly known. The purpose of the present study was to investigate the genetic variation and differentiation among five populations of Trypoxylon albitarse, a species widely distributed throughout the Neotropics, with records from Panama to northern Argentina. Eight species-specific microsatellite loci were used for genotyping 96 adult wasps (one female per nest) sampled at five sites in Brazil. The analysis of allelic richness and private alleles indicated high genetic diversity in the populations sampled. Pairwise comparisons using the Fst and Dest indices revealed significant differentiation for all, but one pair of populations. Fst, Dest, AMOVA and assignment test values pointed to inter-population differentiation. Additionally, the analysis of population structure using Bayesian and PCA methods characterized two alternative genetic groups. The Mantel test indicated no correlation between genetic and geographic distances. Despite evidence of considerable dispersal capacity for T. albitarse, the data indicate low to moderate population structuring in this species.
ABSTRACT
OBJECTIVES: to assess air pollution spatial and temporal variability in the urban area nearby the Ciampino International Airport (Rome) and to investigate the airport-related emissions contribute. DESIGN AND SETTING: the study domain was a 64 km2 area around the airport. Two fifteen-day monitoring campaigns (late spring, winter) were carried out. Results were evaluated using several runs outputs of an airport-related sources Lagrangian particle model and a photochemical model (the Flexible Air quality Regional Model, FARM). MAIN OUTCOME MEASURES: both standard and high time resolution air pollutant concentrations measurements: CO, NO, NO2, C6H6, mass and number concentration of several PM fractions. 46 fixed points (spread over the study area) of NO2 and volatile organic compounds concentrations (fifteen days averages); deterministic models outputs. RESULTS: standard time resolution measurements, as well as model outputs, showed the airport contribution to air pollution levels being little compared to the main source in the area (i.e. vehicular traffic). However, using high time resolution measurements, peaks of particles associated with aircraft takeoff (total number concentration and soot mass concentration), and landing (coarse mass concentration) were observed, when the site measurement was downwind to the runway. CONCLUSIONS: the frequently observed transient spikes associated with aircraft movements could lead to a not negligible contribute to ultrafine, soot and coarse particles exposure of people living around the airport. Such contribute and its spatial and temporal variability should be investigated when assessing the airports air quality impact.
Subject(s)
Air Pollutants/analysis , Air Pollution/analysis , Airports , Rome , Urban HealthABSTRACT
In recent years, the increased use of rhodium (Rh) as an active catalyst material in modern three-way automobile catalytic converters has led to a parallel rise in environmental levels of this metal. In spite of this, the literature contains few studies of the effects of Rh on human health. The aim of this study is to assess the effects of Rh on the renal function of female Wistar rats. Our findings show that sub-acute exposure to six increasing concentrations, ranging from 0.001 to 1 mg L(-1), of Rh (III) chloride hydrate in drinking water does not induce alterations in urinary albumin levels, while, at concentrations from 0.1 to 1 mg L(-1), a significant rise in urinary levels of Retinol Binding Protein is evident and an increasing trend in urinary ß2-microglobulin, which becomes significant at 1 mg L(-1), is observed. These results therefore demonstrate a nephrotoxic action of Rh at tubular level in a wide range of doses. Interestingly, because of the recent increase in environmental Rh levels, these findings may have relevant implications both for occupationally exposed subjects and for the general population, especially children.
Subject(s)
Drinking Water/analysis , Kidney/physiology , Rhodium/metabolism , Water Pollutants, Chemical/metabolism , Animals , Child , Female , Humans , Kidney/drug effects , Male , Rats , Rats, Wistar , Rhodium/analysis , Rhodium/toxicity , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/toxicityABSTRACT
In recent years, nanoparticles have been increasingly used in several industrial, consumer and medical applications because of their unique physico-chemical properties. However, in vitro and in vivo studies have demonstrated that these properties are also closely associated with detrimental health effects. There is a serious lack of information on the potential nanoparticle hazard to human health, particularly on their possible toxic effects on the endocrine system. This topic is of primary importance since the disruption of endocrine functions is associated with severe adverse effects on human health. Consequently, in order to gather information on the hazardous effects of nanoparticles on endocrine organs, we reviewed the data available in the literature regarding the endocrine effects of in vitro and in vivo exposure to different types of nanoparticles. Our aim was to understand the potential endocrine disrupting risks posed by nanoparticles, to assess their underlying mechanisms of action and identify areas in which further investigation is needed in order to obtain a deeper understanding of the role of nanoparticles as endocrine disruptors. Current data support the notion that different types of nanoparticles are capable of altering the normal and physiological activity of the endocrine system. However, a critical evaluation of these findings suggests the need to interpret these results with caution since information on potential endocrine interactions and the toxicity of nanoparticles is quite limited.
Subject(s)
Endocrine Disruptors/toxicity , Endocrine System/drug effects , Endocrine System/physiology , Nanoparticles/toxicity , Animals , Female , Humans , Mice , Neurosecretory Systems/drug effects , Pregnancy , Prenatal Exposure Delayed Effects , Rats , Reproduction/drug effects , Thyroid Gland/drug effectsABSTRACT
BACKGROUND: Single wall carbon nanotubes (SWCNTs) are considered promising nanoparticles for industrial and biomedical applications; however their potential toxicity in several biological systems, including the feto-placental unit, has been demonstrated. Functionalization of SWCNTs with polyethylene glycol chains (PEG-SWCNTs) dramatically reduces their toxicity, and for this reason PEG-SWCNTs are candidates for biomedical applications. However, no data are available on their safety for the developing embryo, in spite of the clinical and social relevance of this topic. The purpose of this study is therefore to investigate the safety of PEG-SWCNTs for their use as biomedical carriers in pregnancy. METHODS: For toxicological studies, amino-functionalized PEG-SWCNT were intravenously injected in CD1 pregnant mice at different doses (range 0.1-30 µg/mouse), in single or multiple administrations. For biodistribution studies, fluorescently labeled PEG-SWCNTs were obtained by acylation of terminal PEG amino groups with near infrared emitting fluorochromes (PEG-SWCNT-750) and injected at the dosage of 10 µg/mouse, at either day 5.5 (when the placenta is still developing) or day 14.5 of gestation (when the maturation of the placenta is complete). RESULTS: We found no adverse effects both on embryos and dams up to the dose of 10 µg/mouse. At the dose of 30 µg/mouse, occasional teratogenic effects, associated with placental damage, were detected both when administered as a single bolus (1 out of 10 dams; 1 malformed embryo) or as multiple doses (2 out of 10 dams; 5 malformed embryos). The difference in the prevalence of dams with malformed embryos between the 30 µg exposed group and controls approached the statistical significance (p = 0.06). Hepatic damage in dams was seen only in the multiple exposure group (4 out of 10; p = 0.04 when compared with the single exposure group or controls). PEG-SWCNT-750 reached the conceptus when administered early in pregnancy. At later stages, PEG-SWCNT-750 were detected in the placenta and the yolk sac, but not in the embryo. CONCLUSIONS: PEG-SWCNTs may cause occasional teratogenic effects in mice beyond a threshold dose. Such effect might depend on their ability to reach the feto-placenta unit. Although not automatically transferable to humans, these data should be considered if exposing women during pregnancy.
Subject(s)
Nanotubes, Carbon/toxicity , Polyethylene Glycols/pharmacokinetics , Polyethylene Glycols/toxicity , Abnormalities, Drug-Induced/etiology , Animals , Embryo, Mammalian/abnormalities , Embryo, Mammalian/drug effects , Embryo, Mammalian/metabolism , Female , Gestational Age , Injections, Intravenous , Luminescent Measurements , Maternal Exposure/adverse effects , Mice , Optical Imaging , Placenta/drug effects , Placenta/metabolism , Pregnancy , Risk Assessment , Tissue Distribution , Whole Body ImagingABSTRACT
OBJECTIVE: To investigate the emission sources of fine and ultrafine particles (UFPs) during brazing, welding, and grinding in a mechanical engineering factory and to characterize UFP exposure by measuring size distributions, number, and surface area concentrations. METHODS: Samplings lasted 4 hours and were conducted during 5 days using the Grimm 1.109 portable aerosol spectrometer, the Grimm portable NanoCheck™ 1.320, the electrical low pressure impactor, and the nanoparticle aerosol monitor AeroTrak™ 9000. RESULTS: Higher concentrations of fine particles were observed in welding and grinding activities. The highest values of UFP number and alveolar surface area concentrations were detected in the welding booth. CONCLUSIONS: Potential emission sources of fine particles and UFPs can be identified by the multifaceted approach outlined in this study. This sampling strategy provides important data on key UFP metrics.
Subject(s)
Air Pollutants, Occupational/analysis , Inhalation Exposure , Occupational Exposure/analysis , Particle Size , Welding , Environmental Monitoring/instrumentation , Environmental Monitoring/methods , Humans , Italy , Sampling StudiesABSTRACT
Iridium tissue distribution and excretion in female Wistar rats following oral exposure to iridium (III) chloride hydrate in drinking water (from 1 to 1000 ng/ml) in a sub-chronic oral study were determined. Samples of urine, feces, blood and organs (kidneys, liver, lung, spleen and brain) were collected at the end of exposure. The most prominent fractions of iridium were retained in kidney and spleen; smaller amounts were found in lungs, liver and brain. Iridium brain levels were lower than those observed in other tissues but this finding can support the hypothesis of iridium capability to cross the blood brain barrier. The iridium kidney levels rose significantly with the administered dose. At the highest dose, important amounts of the metal were found in serum, urine and feces. Iridium was predominantly excreted via feces with a significant linear correlation with the ingested dose, which is likely due to low intestinal absorption of the metal. However, at the higher doses iridium was also eliminated through urine. These findings may be useful to help in the understanding of the adverse health effects, particularly on the immune system, of iridium dispersed in the environment as well as in identifying appropriate biological indices of iridium exposure.
ABSTRACT
Quantitative changes in different cytokines were determined in serum of female Wistar rats exposed to Rhodium (III) chloride hydrate to evaluate its early effects on the immune system. Findings revealed an inhibitory effect of Rh salt since each cytokine, with the exceptions of IL-1α and IL-2 levels observed at the highest doses of exposure, was reduced compared to the controls and interestingly, the lowest doses induced the greatest inhibition. This generalized decrease of cytokine levels was not related to a specific cytokine pathway, and may suggest an anti-inflammatory role of Rh salt.
Subject(s)
Rhodium/toxicity , Animals , Cytokines/metabolism , Female , Rats , Rats, Wistar , Toxicity Tests, SubacuteABSTRACT
Environmental concentration of the platinum group elements is increased in the last years due to their use in automobile catalytic converters. Limited data are available on the effects of such elements at a cellular level and on their toxicity, especially for rhodium and iridium which have been more recently introduced in use. The toxic effects of rhodium and iridium salts were analyzed on a normal diploid rat fibroblast cell line in vitro. Both salts halted cell growth in a dose- and time-dependent fashion by inhibiting cell cycle progression, inducing apoptosis and modulating the expression of cell cycle regulatory proteins. In fact, they both caused an accumulation of cells in the G2/M phase of the cell cycle and affected the expression levels of pRb, cyclins D1 and E, p21(Waf1) and p27(Kip1). DNA strand breaks, as assessed by comet test, and an increase in the intracellular levels of reactive oxygen species also occurred in exposed cell cultures. These findings suggest a potential toxicity of both iridium and rhodium salts and emphasize the need for further studies to understand their effects at a cellular level to enable a better assessment of their toxic effects and to identify ways for their modulation and/or prevention.
Subject(s)
Cell Proliferation/drug effects , DNA Damage , Fibroblasts/drug effects , Iridium/toxicity , Rhodium/toxicity , Animals , Apoptosis/drug effects , Cell Cycle/drug effects , Cell Cycle Proteins/metabolism , Cell Line , Cell Survival/drug effects , Comet Assay , Fibroblasts/metabolism , RatsABSTRACT
The head bobber transgenic mouse line, produced by pronuclear integration, exhibits repetitive head tilting, circling behavior, and severe hearing loss. Transmitted as an autosomal recessive trait, the homozygote has vestibular and cochlea inner ear defects. The space between the semicircular canals is enclosed within the otic capsule creating a vacuous chamber with remnants of the semicircular canals, associated cristae, and vestibular organs. A poorly developed stria vascularis and endolymphatic duct is likely the cause for Reissner's membrane to collapse post-natally onto the organ of Corti in the cochlea. Molecular analyses identified a single integration of ~3 tandemly repeated copies of the transgene, a short duplicated segment of chromosome X and a 648 kb deletion of chromosome 7(F3). The three known genes (Gpr26, Cpxm2, and Chst15) in the deleted region are conserved in mammals and expressed in the wild-type inner ear during vestibular and cochlea development but are absent in homozygous mutant ears. We propose that genes critical for inner ear patterning and differentiation are lost at the head bobber locus and are candidate genes for human deafness and vestibular disorders.
Subject(s)
Deafness/genetics , Ear, Inner/abnormalities , Hyperkinesis/genetics , Mutagenesis, Insertional , Animals , Base Sequence , Body Patterning , Female , Male , Mice , Mice, Transgenic , Molecular Sequence DataABSTRACT
The Italian Decree on Health and Safety at Work (81/08) prescribes mandatory drug tests for jobs which pose safety hazards to others. Workplace drug testing is performed in accordance with the Provision of the Government-Regions Conference, 2008. The aim of our survey was to examine the prevalence of drug use and the main drug findings in a sample of Italian workers performing hazardous jobs. From September 2009 to February 2011, 551 urine samples were collected in 42 Italian companies. Sample collection was carried out at the workplace by qualified laboratory personnel sent from the Institute of Occupational Medicine of the Catholic University (UCSC) of Rome. The workers to be tested were informed the day before, as the law requires. The samples were checked for adulteration, coded, and sent immediately to the laboratory of the UCSC Forensic Toxicology Analytical Unit. The screening test was an immunoassay. The positive samples proceeded to the confirmatory analysis with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The urine samples were analyzed for cannabis, opiates, amphetamines, methamphetamines, cocaine, methadone, and MDMA. Out of 16 samples .9% screened positive; only 4 of them (0.7%) were confirmed with the LC-MS/MS. Confirmed results included cocaine (2 samples), cannabis (1 sample), both cocaine and cannabis (1 sample). The prevalence of positive samples was lower than expected. Such finding cannot be explained by a low reliability of the testing procedure but could be due to test scheduling. More positive cases might be found performing short-notice random testing.
Subject(s)
Illicit Drugs/urine , Substance Abuse Detection/methods , Workplace , Adolescent , Adult , Aged , Chromatography, Liquid/methods , Female , Forensic Toxicology/methods , Humans , Immunoassay/methods , Italy , Male , Middle Aged , Substance Abuse Detection/legislation & jurisprudence , Tandem Mass Spectrometry/methods , Workplace/legislation & jurisprudence , Young AdultABSTRACT
Despite the widespread use of iridium (Ir) in catalytic converters for improved capacity for reducing carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NO(x)) emissions, there is a lack of studies that have assessed possible toxicological hazards of exposure to Ir. The present investigation indicates that female Wistar rats exposed to Ir in the drinking water for 90 days displayed renal toxicity based on the elevated urinary retinol binding protein (RBP) and albumin. The RBP was more sensitive to albumin, showing significant increases at 0.01 mg/L.
Subject(s)
Iridium/toxicity , Kidney Diseases/chemically induced , Kidney/physiopathology , Albuminuria/chemically induced , Animals , Drinking Water , Environmental Pollutants/toxicity , Female , Iridium/urine , Rats , Rats, Wistar , Retinol-Binding Proteins/urine , Toxicity Tests, Subchronic , beta 2-Microglobulin/urineABSTRACT
BACKGROUND: To evaluate whether occupational stress factors (high demands, low control, low social support, strain, and iso-strain) are associated with skin disorders in hospital workers and whether psychological problems, such as anxiety and depression, act as potential mechanisms through which occupational stress factors are associated with skin disorders. METHODS: 1,744 hospital workers were invited to answer a questionnaire concerning the occurrence of skin disorders and psychosocial factors at work. The abbreviated Italian version of the Demand/Control model (Karasek) was used to assess perceived work strain, while the Goldberg scales were used to assess anxiety and depression. Analyses were adjusted for age, gender, occupation, latex glove use and history of atopy. RESULTS: Of the participants, 25% reported hand dermatitis in the previous 12 months and 35% had been affected by skin disorders in other parts of the body. High job demands (OR = 1.09 CI95% 1.05-1.14), low social support (OR = 0.90, CI95% 0.87-0.93), high strain (OR = 1.54 CI95% 1.20-1.98) and high iso-strain (1.66 CI95% 1.27-2.19) were all associated with a higher prevalence of reported hand skin disorders. Both depression (OR = 2.50 CI95% 1.99-3.14) and anxiety (OR = 2.29 CI95% 1.81-2.89) were associated with higher risk of hand skin disorders. The same pattern was observed for dermatological complaints in other parts of the body. Only a slight reduction in the association between occupational stress variables and skin disorders was observed after including depression and anxiety in the model. CONCLUSIONS: Job stress plays a significant role in triggering skin disorders among hospital workers and psychological problems do not appear to be the mechanism behind this association. Occupational health education and training should focus on reducing job demands and occupational stress in order to prevent skin problems among hospital workers.
Subject(s)
Personnel, Hospital , Skin Diseases/etiology , Stress, Psychological/complications , Adult , Cross-Sectional Studies , Female , Humans , Italy/epidemiology , Male , Middle Aged , Occupational Exposure/adverse effects , Skin Diseases/epidemiology , Social SupportABSTRACT
Several in vitro and in vivo studies suggest local and systemic effects following exposure to carbon nanotubes. No data are available, however, on their possible embryotoxicity in mammals. In this study, we tested the effect of pristine and oxidized single-wall carbon nanotubes (SWCNTs) on the development of the mouse embryo. To this end, SWCNTs (from 10 ng to 30 µg/mouse) were administered to female mice soon after implantation (postcoital day 5.5); 10 days later, animals were sacrificed, and uteri, placentas, and fetuses examined. A high percentage of early miscarriages and fetal malformations was observed in females exposed to oxidized SWCNTs, while lower percentages were found in animals exposed to the pristine material. The lowest effective dose was 100 ng/mouse. Extensive vascular lesions and increased production of reactive oxygen species (ROS) were detected in placentas of malformed but not of normally developed fetuses. Increased ROS levels were likewise detected in malformed fetuses. No increased ROS production or evident morphological alterations were observed in maternal tissues. No fetal and placental abnormalities were ever observed in control animals. In parallel, SWCNT embryotoxicity was evaluated using the embryonic stem cell test (EST), a validated in vitro assay developed for predicting embryotoxicity of soluble chemical compounds, but never applied in full to nanoparticles. The EST predicted the in vivo data, identifying oxidized SWCNTs as the more toxic compound.
Subject(s)
Embryonic Development/drug effects , Nanotechnology/methods , Nanotubes, Carbon/chemistry , Animals , Embryonic Stem Cells/cytology , Female , Immunohistochemistry/methods , Mice , Microscopy, Electron, Transmission/methods , NIH 3T3 Cells , Nanomedicine/methods , Nanoparticles/chemistry , Oxidative Stress , Oxygen/chemistry , Reactive Oxygen Species , Time FactorsABSTRACT
Physical and moral violence against the workers of a local public health unit is perspectively studied in the period 2005-2011. Data were collected during periodic medical surveillance of all workers exposed to risk and with more than one year of seniority. The prevalence of the phenomenon is constant in the period under review. On average, each year a worker in ten is physically assaulted, and one in five is subjected to verbal abuse. The professional groups most exposed to violence are nurses (OR 2.67 IC95% 1.63-4.39) and doctors (OR 2.44 IC95% 1.34-4.46). The areas at greatest risk are the psychiatric care (OR 25.7, IC95% 11.1-59.6) and emergency and first aid (OR 8.8, CI95% 3.8-20.5). The workplace violence against health workers requires urgent preventive interventions.
Subject(s)
Health Personnel , Occupational Exposure , Population Surveillance , Violence/statistics & numerical data , Female , Humans , Male , Time Factors , WorkplaceABSTRACT
BACKGROUND: Previous benefit-risk perception studies and social experiences have clearly demonstrated that any emerging technology platform that ignores benefit-risk perception by citizens might jeopardize its public acceptability and further development. The aim of this survey was to investigate the Italian judgment on nanotechnology and which demographic and heuristic variables were most influential in shaping public perceptions of the benefits and risks of nanotechnology. METHODS: In this regard, we investigated the role of four demographic (age, gender, education, and religion) and one heuristic (knowledge) predisposing factors. RESULTS: The present study shows that gender, education, and knowledge (but not age and religion) influenced the Italian perception of how nanotechnology will (positively or negatively) affect some areas of everyday life in the next twenty years. Furthermore, the picture that emerged from our study is that Italian citizens, despite minimal familiarity with nanotechnology, showed optimism towards nanotechnology applications, especially those related to health and medicine (nanomedicine). The high regard for nanomedicine was tied to the perception of risks associated with environmental and societal implications (division among social classes and increased public expenses) rather than health issues. However, more highly educated people showed greater concern for health issues but this did not decrease their strong belief about the benefits that nanotechnology would bring to medical fields. CONCLUSION: The results reported here suggest that public optimism towards nanomedicine appears to justify increased scientific effort and funding for medical applications of nanotechnology. It also obligates toxicologists, politicians, journalists, entrepreneurs, and policymakers to establish a more responsible dialog with citizens regarding the nature and implications of this emerging technology platform.
Subject(s)
Nanomedicine , Public Opinion , Adult , Educational Status , Female , Humans , Italy , Male , Perception , Risk Assessment , Surveys and QuestionnairesABSTRACT
Nanotechnology-introduced materials have promising applications as nanocarriers for drugs, peptides, proteins and nucleic acids. Several studies showed that the geometry (shape and size) and chemical properties of nanoparticles affect the kinetics and pathways of cellular uptake and their intracellular trafficking and signaling. Accurate physico-chemical characterization of nanoparticles customarily precedes their use in cell biology and in vivo experiments. However, a fact that is easily overlooked is that nanomaterials decorated with organic matter or resuspended in aqueous buffers can be theoretically contaminated by fungal and bacterial microorganisms. While investigating the effects of extensively characterized PEGylated carbon nanotubes (PNTs) on T lymphocyte activation, we demonstrated bacterial contamination of PNTs, which correlated with low reproducibility and artifacts in cell signaling assays. Contamination and artifacts were easily eliminated by preparing the materials in sterile conditions. We propose that simple sterile preparation procedures should be adopted and sterility evaluation of nanoparticles should be customarily performed, prior to assessing nanoparticle intracellular internalization, trafficking and their effects on cells and entire organisms.
Subject(s)
Drug Carriers , Drug Contamination , Nanoconjugates/microbiology , Nanotubes, Carbon/microbiology , Artifacts , Endocytosis/drug effects , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Humans , Interleukin-2/genetics , Interleukin-2/metabolism , Jurkat Cells , Microscopy, Atomic Force , Microscopy, Confocal , Nanoconjugates/chemistry , Nanotubes, Carbon/chemistry , Particle Size , Polyethylene Glycols , Reproducibility of Results , T-Lymphocytes/drug effects , T-Lymphocytes/metabolism , Toll-Like Receptors/metabolismABSTRACT
Cement is widely used for construction and several reports have suggested a potential toxicity of cement dusts although it has never been definitively assessed. To determine the cytotoxic and bioactive effects of cement dusts, cultures of normal rat fibroblasts were exposed to different types of cements and cell growth parameters, apoptosis and the occurrence of DNA damage (both in terms of DNA breaks and oxidative damage) were analyzed. Cells were exposed to cement extracts or cultured in direct contact with cement dusts and the results obtained were compared to cells cultured in fresh medium. A dose-dependent decrease in viable cells was observed with all tested cements. Different results were obtained in the cell-cement direct contact tests compared to the indirect contact tests performed using extracts. Inhibition of cell growth was associated in most cases with an accumulation of cells in the S-phase of the cell-cycle and the appearance of an apoptotic peak. DNA strand breaks, assessed by comet test, and increase in the levels of 8-OHdG, an important marker of DNA oxidative damage, always occurred by incubating cells in the presence of cement extracts or dusts. However, after removal of cement, a rapid damage repair was generally observed with an almost complete recovery within 12 hours. In conclusion, all cements analyzed in this study displayed a limited toxicity in vitro without significant differences amongst them. Overall, the results obtained indicate that cements should be treated as hazardous materials but they do not allow to make accurate predictions regarding the in vivo effects. Further studies are warranted to reach a better understanding of the potential toxic effects of cements, to identify the responsible mechanisms and to evaluate the possibility of modulating and/ or preventing them.
Subject(s)
Construction Materials/toxicity , DNA Damage/drug effects , Dust , Toxicity Tests/methods , Animals , Cell Cycle/drug effects , Cell Line, Transformed , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Environmental Exposure , Fibroblasts , Inhibitory Concentration 50 , Oxidative Stress/drug effects , RatsABSTRACT
OBJECTIVE: The purpose of this study is to assess the risk of medical malpractice litigation for Italian radiologists, compared with the corresponding data in the literature. MATERIALS AND METHODS: The insurance claims of Italian radiologists over the 1993-2006 period were anonymously assessed and classified according to the cause of the claim. RESULTS: A total of 1,424 claims were filed during the examined period, with most claims being filed at a considerable time interval after the event (up to 10 years). The resulting incidence may be estimated as 44.2 cases per 1,000, meaning that 44% of Italian radiologists have received, or will receive, summons regarding their professional activity during the past 10 years. CONCLUSION: The risk of medical malpractice litigation for Italian radiologists is by now comparable to that for American radiologists. Comparison with previous data concerning the same study population shows that the diagnostic errors category has surpassed all other error categories (nondiagnostic errors) and that, within the diagnostic errors category, claims for allegedly missed cancer have surpassed claims for allegedly missed bone abnormalities. Among missed diagnosis claims, the maximum increase concerned mammograms. Strict adherence to radiologic standards and radiotherapy protocols may be a means of reducing the risk of legal action and obviating litigation.