Microgravity Modifies the Phenotype of Fibroblast and Promotes Remodeling of the Fibroblast-Keratinocyte Interaction in a 3D Co-Culture Model.

Microgravity impairs tissue organization and critical pathways involved in the cell-microenvironment interplay, where fibroblasts have a critical role. We exposed dermal fibroblasts to simulated microgravity by means of a Random Positioning Machine (RPM), a device that reproduces conditions of weightlessness. Molecular and structural changes were analyzed and compared to control samples growing in a normal gravity field. Simulated microgravity impairs fibroblast conversion into myofibroblast and inhibits their migratory properties. Consequently, the normal interplay between fibroblasts and keratinocytes were remarkably altered in 3D co-culture experiments, giving rise to several ultra-structural abnormalities. Such phenotypic changes are associated with down-regulation of α-SMA that translocate in the nucleoplasm, altogether with the concomitant modification of the actin-vinculin apparatus. Noticeably, the stress associated with weightlessness induced oxidative damage, which seemed to concur with such modifications. These findings disclose new opportunities to establish antioxidant strategies that counteract the microgravity-induced disruptive effects on fibroblasts and tissue organization.

Could combustion-generated nanoparticles induce cytotoxicity also at the extremely low doses typical of indoor environments?

SUMMARY: The presence of nanoparticles in the environment is mainly attributed to outdoor sources but sub-10 nm particles may also form indoor as effect of domestic activities such as cooking, heating, air freshening. Today, due to the COVID-19 pandemic, people are staying home for longer periods of times, thus being exposed to a poor indoor air quality. Due to elevated numerical concentration and large surface area, the health effect of sub-10 nm particles can go beyond what expected from their low mass concentration in the atmosphere. The objective of this study is to find, based on analysis of recent in vitro studies, a dose-effect correlation based on particle size/surface more than on particle mass. Such a correlation cold be useful to assess the health effects of people exposed to very low mass doses of nanoparticles either indoor or outdoor.

Work-related upper limb disorders and risk assessment among automobile manufacturing workers: A retrospective cohort analysis.

OBJECTIVE: To estimate the three-year cumulative risk of work-related upper limb disorders (WRULDs) in a cohort of automotive industry workers and to provide a first test of the ability of the European Assembly Worksheet (EAWS) methodology to predict WRULDs. METHODS: 292 workers were investigated by reviewing workers' medical records during the period from 2012-2015 to determine their exposure to biomechanical overload according to EAWS risk scores (0-25, low risk, Green zone; 26-50, medium risk, Yellow zone; >50, High risk; Red zone). RESULTS: The risks were 0.83%, 5.71%, and 11.88% for the Control (unexposed), Green and Yellow Groups, respectively. Only the comparison between the Yellow/Control Groups was significant (p = 0.0014). In total, we observed 17 cases of musculoskeletal disorders (MSDs) (14 symptomatic and 3 cases detected by physical examination). CONCLUSIONS: The EAWS is a useful tool for the preliminary risk assessments of biomechanical overload among automotive industry workers. The finding of mainly non-specific disorders highly suggests that health surveillance should aim to identify not only full-blown diseases but also symptomatic cases.

In vitro intestinal epithelium responses to titanium dioxide nanoparticles.

Titanium dioxide (TiO2) is enclosed in many consumer products including pharmaceuticals, cosmetics, and foods. TiO2 (E171) is daily ingested as mixed nano- and submicron-sized particles since it is approved as a white colorant in Europe in a wide variety of food products, Noteworthy, the relevant risk assessment has never been satisfactorily concluded and growing alarms for human hazards deriving from TiO2 exposure are incrementally reported. The objective of the present study was to establish conceivable mechanisms by which nano-sized TiO2 particles affect physiological function of the intestinal epithelium layer. The well-established Caco-2 cell line differentiated for 21 days on permeable supports was used as a predictive model of the human intestinal mucosa to identify the biological response triggered by TiO2 particles. Exposure to 42 µg/mL TiO2 nanoparticles disrupted the tight junctions-permeability barrier with a prompt effect detectable after 4 h incubation time and wide effects on barrier integrity at 24 h. Transport and ultrastructural localization of TiO2 nanoparticles were determined by ICP-OES, TEM and ESI/EELS analysis, respectively. Nano-sized particles were efficiently internalized and preferentially entrapped by Caco-2 monolayers. Storage of TiO2 nanoparticles inside the cells affected enterocytes viability and triggered the production of pro-inflammatory cytokines, including TNF-α and IL-8. Taken together these data indicate that nano-sized TiO2 particles exert detrimental effects on the intestinal epithelium layer.

The unrecognized occupational relevance of the interaction between engineered nanomaterials and the gastro-intestinal tract: a consensus paper from a multidisciplinary working group.

BACKGROUND: There is a fundamental gap of knowledge on the health effects caused by the interaction of engineered nanomaterials (ENM) with the gastro-intestinal tract (GIT). This is partly due to the incomplete knowledge of the complex physical and chemical transformations that ENM undergo in the GIT, and partly to the widespread belief that GIT health effects of ENM are much less relevant than pulmonary effects. However, recent experimental findings, considering the role of new players in gut physiology (e.g. the microbiota), shed light on several outcomes of the interaction ENM/GIT. Along with this new information, there is growing direct and indirect evidence that not only ingested ENM, but also inhaled ENM may impact on the GIT. This fact, which may have relevant implications in occupational setting, has never been taken into consideration. This review paper summarizes the opinions and findings of a multidisciplinary team of experts, focusing on two main aspects of the issue: 1) ENM interactions within the GIT and their possible consequences, and 2) relevance of gastro-intestinal effects of inhaled ENMs. Under point 1, we analyzed how luminal gut-constituents, including mucus, may influence the adherence of ENM to cell surfaces in a size-dependent manner, and how intestinal permeability may be affected by different physico-chemical characteristics of ENM. Cytotoxic, oxidative, genotoxic and inflammatory effects on different GIT cells, as well as effects on microbiota, are also discussed. Concerning point 2, recent studies highlight the relevance of gastro-intestinal handling of inhaled ENM, showing significant excretion with feces of inhaled ENM and supporting the hypothesis that GIT should be considered an important target of extrapulmonary effects of inhaled ENM. CONCLUSIONS: In spite of recent insights on the relevance of the GIT as a target for toxic effects of nanoparticles, there is still a major gap in knowledge regarding the impact of the direct versus indirect oral exposure. This fact probably applies also to larger particles and dictates careful consideration in workers, who carry the highest risk of exposure to particulate matter.

Exposure to sub-10nm particles emitted from a biodiesel-fueled diesel engine: In vitro toxicity and inflammatory potential.

OBJECTIVES: The inflammatory effects of organic sub-10nm particles generated and emitted from a diesel engine fueled with a biodiesel and a commercial diesel oil are analyzed in this paper. Diesel combustion is the major sources of ultrafine particles (UFP) in the environment, particularly in urbanized areas. In the last years, there is an increasing use of biomass-derived fuels because they are a renewable source of energy that may mitigate climate change through the reduction of net CO2 with respect to conventional fossil fuels. Although there is a general agreement on biofuels ability to reduce conventional pollutants, new and potentially harmful pollutants can be formed during biofuel combustion. In particular, the emission of sub-10nm particles is strongly increased with respect to that of larger soot particles. METHODS: Organic sub-10nm particles are separated from larger sizes particulate matter by collection in water suspension for toxicological and inflammatory tests. After exposure to sub-10nm particles, the effects on proliferation, apoptosis and secretion of cytokines, chemokines and growth factors networks production is analyzed in immortalized non-tumorigenic human dermal keratinocyte cell line (HaCaT) and human alveolar epithelial-like cells (A549). RESULTS AND CONCLUSION: Nanoparticles exert different cytotoxic effects in the two cell lines, suggesting that the dermal way of exposure is more sensitive than the inhalant way. These differences are most evident in the secretion of pro-inflammatory, angiogenic and proliferative cytokines and chemokines whose expression is more finely modulated in HaCaT cells compared to A-549 cells. Considering the size of these particles, it is important to promote the culture of prevention also for the dermal way in particularly exposed workers.

Environmental and occupational exposure to bisphenol A and endometriosis: urinary and peritoneal fluid concentration levels.

OBJECTIVES: The study aimed to give a first data set of bisphenol A (BPA) levels in the peritoneal fluid of patients suffering from endometriosis and to investigate the relationship between BPA exposure and endometriosis. METHODS: A questionnaire investigating the occupational context, life environment, and habits was administered to 68 patients suffering from endometriosis and 60 endometriosis-free subjects (control group). Urine and peritoneal fluids samples were collected and analysed by GC/MSMS for BPA dosage. RESULTS: Some of the investigated environmental/lifestyle risk factors (closeness to industries/activities at risk) were associated with an increase in endometriosis; smoking resulted as protective factor; others (use of food plastic boxes) did not seem to influence the onset of pathology. The association between the occupational exposure summarising all examined risk factors (working activity, personal protective equipment, seniority) and endometriosis was statistically significant (χ 2 = 5.252, p = 0.02). Contrasting results were obtained when specific activities were examined. Detectable urinary BPA levels were found in all analysed samples (patients: 1.17-12.68 pg/µl; mean ± SD, 5.31 ± 3.36 pg/µl; control group: 1.28-2.35 pg/µl; mean ± SD, 1.64 ± 0.49 pg/µl; median; 1.46 pg/µl), with a statistically significant difference between patients and controls, showing an association between BPA exposure and endometriosis. Only a few subjects from the control group supplied peritoneal fluid; hence, no comparison test with patients (range 0.39-1.46 pg/µl; mean ± SD, 0.67 ± 0.30 pg/µl; median, 0.58 pg/µl) was carried out. CONCLUSIONS: Results highlight the potential association between BPA exposure and endometriosis, as well as the current lack of knowledge regarding occupational exposure to BPA and the need of epidemiological studies focused on single activities/occupations, such as housewives, cleaners, students.

Risk agents related to work and amyotrophic lateral sclerosis: An occupational medicine focus.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive muscular paralysis reflecting degeneration of motor neurons. In recent years, in addition to several studies about genetic mechanisms leading to motor neurons damage, various epigenetic theories have been developed, involving the study of the patients' work and lifestyle. The work aims at focusing the role of occupational exposure related to ALS by literature data analysis. Articles, selected on the basis of keywords, year of publication and topics, are related to occupational exposure, suggesting an impact on ALS onset. The literature review shows that there are still a lot of biases in the studies design, which actually do not allow to draw unequivocal conclusions.

[Professional divers: analysis of critical issues and proposal of a health protocol for work fitness]. / Il lavoratore subacqueo: analisi delle criticità e proposto di un protocollo sanitario per l'idoneità al lavoro.

INTRODUCTION: From many years now, thanks to the development of modern diving techniques, there has been a rapid spread of diving activities everywhere. In fact, divers are ever more numerous both among the Armed Forces and civilians who dive for work, like fishing, biological research and archeology. AIM: The aim of the study was to propose a health protocol for work fitness of professional divers keeping in mind the peculiar work activity, existing Italian legislation that is almost out of date and the technical and scientific evolution in this occupational field. METHOD: We performed an analysis of the most frequently occurring diseases among professional divers and of the clinical investigation and imaging techniques used for work fitness assessment of professional divers. RESULTS: From analysis of the health protocol recommended by D.M. 13 January 1979 (Ministerial Decree), that is most used by occupational health physician, several critical issues emerged. Very often the clinical investigation and imaging techniques still used are almost obsolete, ignoring the execution of simple and inexpensive investigations that are more useful for work fitness assessment. CONCLUSIONS: Considering the out-dated legislation concerning diving disciplines, it is necessary to draw up a common health protocol that takes into account clinical and scientific knowledge and skills acquired in this area. This protocol's aim is to propose a useful tool for occupational health physicians who work in this sector.

Working conditions and mental health: Results from the CARESUN study.

The authors conducted a work-related stress surveillance study in 2013 on 6,558 public-sector employees in Italy, examining how they perceived their jobs, via the Job Content Questionnaire, and their mental health status, via the General Health Questionnaire 12 (GHQ-12). Of the 2,094 employees completing the questionnaires, 60% were male, 52% had a medium-level education, and 76% had a medium-level job. Three hundred and eighty-five employees (18%) had a GHQ-12 score >3 and were classified as GHQ-12 cases: these were more often female (54%), medium-to-highly educated (54%), and had more often reported health problems over the previous year (51%). Thus, GHQ-12 cases represented a significant percentage of the examined population, indicating that work-related stress surveillance programs are needed for the planning of psychosocial interventions aimed at the reintegration of individuals with mental health problems.

Immunotoxicological impact of occupational and environmental nanoparticles exposure: The influence of physical, chemical, and combined characteristics of the particles.

While nanotechnology is growing exponentially, the knowledge of the impact of nanoparticles (NPs) on public health and the environment is limited so far. Current nanomaterial research is focused on the applications of nanotechnology, whereas there is little information on exposure assessment and risk characterization associated with NPs. Therefore, it is essential that the factors influencing NPs associated hazards be studied. This review seeks to survey and evaluate the current literature in order to better understand the impact of both airborne and engineered NPs exposure, the mechanisms at the cellular level, and the factors influencing their immunotoxicity. In fact, NPs do have immunotoxicological significance, as immune cells in the bloodstream and tissues do act to eliminate or interact with NPs.Proper characterization of the NPs as well as understanding the processes occurring on the NPs surface when in contact with biological systems is crucial to predict or exclude toxicological effects.

"Are we forgetting the smallest, sub 10 nm combustion generated particles?".

Although mass emissions of combustion-generated particulate matter have been substantially reduced by new combustion technology, there is still a great concern about the emissions of huge numbers of sub-10 nm particles with insignificant mass. These particles have up to orders of magnitude higher surface area to mass ratios compared to larger particles, have surfaces covered with adsorbed volatile and semi-volatile organic species or even are constituted by such species. Currently there is only very little information available on exposure and related health effects specific for smaller particles and first evidences for long-term health effects has only been recently published. However, the fact that these nanoparticles are not easily measured at the exhausts and in the atmosphere and that their biological activity is obscure does not mean that we can overlook them. There is an urgent need to develop i) reliable methods to measure sub-10 nm particles at the exhaust and in the atmosphere and ii) a robust correlation between the chemical structure of the molecules making up combustion-generated nanoparticles and health burden of new combustion technologies. Our attention has to turn to this new class of combustion-generated nanoparticles, which might be the future major constituents of air pollution.

[Amyotrophic lateral sclerosis and exposure to metals and other occupational/environmental hazardous materials: state of the art]. / Sclerosi laterale amiotrofica ed esposizione a metalli ed altri agenti di rischio di natura occupazionale/ambientale: stato dell'arte.

In recent years, scientific literature has been giving more and more importance to the study of the occupational/environmental exposure to risk agents related to the onset of Amyotrophic Lateral Sclerosis (ALS), a neurodegenerative disease characterized by progressive muscular paralysis reflecting degeneration of motor neurons in the primary motor cortex. Aim of this work is to verify the state of art about the eventual role of occupational/environmental exposure to risk agents. Selected articles, on the basis of keywords, year of publication and topics, are related to occupational and environmental exposure to xenobiotics, and, in particular, to the exposure to heavy metals that could lead to neuronal damage mechanisms involved in ALS onset. The review shows that although the scientific production has increased the interest in the evaluation of extra-genetic causes of ALS onset, there are still few studies concerning the careful study of the work activities of the individual patient, and the inferences that can be drawn to date about the possible connection between occupational exposure to risk factors and the onset of ALS are still lacking.

Engineered metal based nanoparticles and innate immunity.

Almost all people in developed countries are exposed to metal nanoparticles (MeNPs) that are used in a large number of applications including medical (for diagnostic and therapeutic purposes). Once inside the body, absorbed by inhalation, contact, ingestion and injection, MeNPs can translocate to tissues and, as any foreign substance, are likely to encounter the innate immunity system that represent a non-specific first line of defense against potential threats to the host. In this review, we will discuss the possible effects of MeNPs on various components of the innate immunity (both specific cells and barriers). Most important is that there are no reports of immune diseases induced by MeNPs exposure: we are operating in a safe area. However, in vitro assays show that MeNPs have some effects on innate immunity, the main being toxicity (both cyto- and genotoxicity) and interference with the activity of various cells through modification of membrane receptors, gene expression and cytokine production. Such effects can have both negative and positive relevant impacts on humans. On the one hand, people exposed to high levels of MeNPs, as workers of industries producing or applying MeNPs, should be monitored for possible health effects. On the other hand, understanding the modality of the effects on immune responses is essential to develop medical applications for MeNPs. Indeed, those MeNPs that are able to stimulate immune cells could be used to develop of new vaccines, promote immunity against tumors and suppress autoimmunity.

Blood lead, manganese, and aluminum levels in a regional Italian cohort of ALS patients: does aluminum have an influence?

OBJECTIVES: To study aluminum (Al), manganese (Mn), and lead (Pb) influence on amyotrophic lateral sclerosis (ALS) development. METHODS: A total of 34 patients (10% of the regional ALS population) and 25 controls of an Italian region were enrolled. Metal concentrations were determined by atomic absorption spectroscopy. RESULTS: Serum Al concentrations in patients and controls were similar and lower than those provided by the Italian Society of Reference Values. No differences were observed in serum Mn concentrations, while, as expected, blood Pb levels were significantly higher in patients with ALS than those in controls. CONCLUSIONS: Results confirmed the association between high Pb blood levels and ALS; on the contrary, Al and Mn did not differ significantly in patients and controls, suggesting that Mn and especially Al may play a less important role in the ALS pathogenesis.

[Using the Mini-Mental State Examination (MMSE) for preliminary assessment of cognitive impairment in subjects exposed to air pollution with particulate matter]. / Utilizzo del Mini-Mental State Examination (MMSE) per la valutazione preliminare del deterioramento cognitivo in soggetti esposti a particolato atmosferico.

Epidemiologic and clinical studies have linked elevated concentrations of particulate matter to adverse health effects. In particular, has been demonstrated an association between UFPs exposure and occurrence of acute respiratory infections, lung cancer, chronic chronic obstructive pulmonary diseases and cardiovascular diseases. Recently, the exposure to particulate air pollution has been linked to cognitive decline. In this work, we used the Mini-Mental State Examination (MMSE) in a preliminary assessment of cognitive function in individuals who have lived and carried out work in heavily urbanized areas, where ambient levels of particulate air pollution were frequently above the standard of the law. The results showed the presence of mild-moderate cognitive impairment in 39.4% of the subjects examined compared to the control group.

Apoptotic and proinflammatory effect of combustion-generated organic nanoparticles in endothelial cells.

Air pollution exposure in industrialized cities is associated with an increased risk of morbidity and mortality attributed to cardiovascular diseases. Combustion exhausts emitted from motor vehicles and industries represent a major source of nanoparticles in the atmosphere. Flame-generated organic carbon nanoparticles (OC NPs) provide interesting model nanoparticles that simulate fresh combustion emissions near roadways or combustion sources. These model nanoparticles can be produced by controlling flame operating conditions and used to test possible toxicological mechanisms responsible for the observed health effects. OC NPs were used to investigate their possible effect on endothelial cells (EC) growth and production of proinflammatory lipid mediators. Results indicated a dose and time-dependent reduction in cell viability following incubation of EC with OC NPs for 24 and 48h. Fluorescence-activated cell sorting revealed that EC treated with OC NPs showed a cell proliferation index significantly lower than that of control cells and an increased apoptotic cell death. The annexin assay confirmed the increased apoptotic cell death. Moreover, OC NPs also induced a time-dependent increase of proinflammatory lysophospholipid production. These results, establishing that OC NPs induce EC proinflammatory lysophosholipid production and apoptotic cell death, provide the first evidence of the detrimental effect of OC NPs on EC.

Epirubicin permeation of personal protective equipment can induce apoptosis in keratinocytes.

The present study investigated the epirubicin (EPI) permeability of various commercially available glove types, as well as toxicity mechanisms and effects on human keratinocyte cell line (HaCaT). Permeability experiments were carried out on various commercially available gloves, differing as regards material and thickness. Permeability was evaluated after different "contact times" and the influence of EPI solution's pH (acid and neutral) on permeability was also examined. Toxicity of EPI toward skin was tested by evaluating the effects of the drug on cell growth and apoptosis, by using an in vitro model based on cultured immortalized human keratinocytes. No permeation was detected in the case of EPI neutral solutions; in contrast, acid solutions were found to penetrate low thickness nitrile gloves. Obtained results also showed the induction of apoptosis in epithelial cells through the activation of intrinsic pathway p53-independent occurring even when cells are exposed at low drug concentration. EPI solution's pH influences the glove's permeability; once penetrated, EPI at concentrations lower than those able to penetrate the nitrile glove during the 8-h work-shift can cause apoptosis in epithelial cells. The findings reported here highly support the choice of either natural rubbers gloves or high thickness nitrile ones for preventing the occupational exposure to EPI.

Functional changes in human peripheral neutrophils in workers with different exposure to noxious agents.

Peripheral neutrophils (PMN) are a useful model to study cell activation and to evaluate the multiple stressors' interference with signalling pathways. This study aimed to evaluate the effects of different exposure to noxious agents on PMN activity by chemiluminescence assays. Two groups of office workers were recruited: peripheral whole blood cells and isolated PMNs were analyzed, performing intra- and extra-cellular chemiluminescence evaluation to study compartmental release of radical species. The exposed group shows a higher emission in resting whole blood chemiluminescence than in controls; the intracellular chemiluminescence emission in urban employees was increased, whereas the extracellular was not affected. After stimulation, the extracellular chemiluminescence was decreased in urban employees, whereas the intracellular emission did not show differences. We hypothesize that once stimulated, exposed subjects' PMNs respond to stimuli less than unexposed: PMNs could be considered indicators of chronic exposure to noxious agents.

Interaction between combustion-generated organic nanoparticles and biological systems: in vitro study of cell toxicity and apoptosis in human keratinocytes.

The purpose of this work was to evaluate the effect of flame-generated nucleation mode particles with an organic carbon structure on growth and apoptosis in immortalized human keratinocytes. In this study, cells were stimulated with nanoparticles collected from flames that produce only nucleation mode particles operating with a fuel:air mixture typical of low-emission combustion systems. Cytotoxicity as a function of particle concentration was monitored by fluorescence-activated cell sorting (FACS) analysis, and apoptosis was observed by FACS using DNA fragmentation and hypodiploidism and confirmed by annexin assay. A dose-dependent reduction in cell viability by apoptosis in incubation periods of 48 and 72 hours was observed with a statistically significant increase in apoptosis over controls for a dose larger than 7 µg/mL (1.4 µg/cm²). The results presented here may be relevant for understanding the association between exposure to traffic-generated particulate pollution and enhanced skin aging reported in epidemiology studies.