Smart working and tele-conferences during the lockdown caused by COVID-19 bring new editorial guidelines.

At the time of writing, the COVID-19 pandemic is assuming a distinct shape as do healthcare systems around the world. Some countries resisted to the tsunami and are now re-opening their industrial and commercial activities while re-organizing to face a possible new wave. Others are still struggling not to be overwhelmed by the most significant public health challenge of the last century. In Italy, after a strict lockdown, almost all activities are re-opening, trying to navigate between Scylla (epidemics and its economic consequences) and Cariddi (economic recession and its adverse health effects) bearing in mind that there is collinearity between the circulation of money and spreading of the virus and that there is a serious risk of a vicious spiral which could affect the society. The prolonged lockdown deemed to prevent the spreading of the virus also reduced the circulation of money, and hence tax revenues, thus it will ultimately result in fewer finances available for social security and Public Health (3). The main political issue will then be the definition of a right point of equilibrium between risks and benefits, between action and precaution. As scientists, we are called to distinguish between what we know and what is unknown, between data and opinions, between facts and beliefs. [...].

Occupational Medicine in the time of COVID-19.

Editorial.

Subchronic exposure to titanium dioxide nanoparticles modifies cardiac structure and performance in spontaneously hypertensive rats.

BACKGROUND: Non-communicable diseases, intended as the results of a combination of inherited, environmental and biological factors, kill 40 million people each year, equivalent to roughly 70% of all premature deaths globally. The possibility that manufactured nanoparticles (NPs) may affect cardiac performance, has led to recognize NPs-exposure not only as a major Public Health concern, but also as an occupational hazard. In volunteers, NPs-exposure is problematic to quantify. We recently found that inhaled titanium dioxide NPs, one of the most produced engineered nanomaterials, acutely increased cardiac excitability and promoted arrhythmogenesis in normotensive rats by a direct interaction with cardiac cells. We hypothesized that such scenario can be exacerbated by latent cardiovascular disorders such as hypertension. RESULTS: We monitored cardiac electromechanical performance in spontaneously hypertensive rats (SHRs) exposed to titanium dioxide NPs for 6 weeks using a combination of cardiac functional measurements associated with toxicological, immunological, physical and genetic assays. Longitudinal radio-telemetry ECG recordings and multiple-lead epicardial potential mapping revealed that atrial activation times significantly increased as well as proneness to arrhythmia. At the third week of nanoparticles administration, the lung and cardiac tissue encountered a maladaptive irreversible structural remodelling starting with increased pro-inflammatory cytokines levels and lipid peroxidation, resulting in upregulation of the main pro-fibrotic cardiac genes. At the end of the exposure, the majority of spontaneous arrhythmic events terminated, while cardiac hemodynamic deteriorated and a significant accumulation of fibrotic tissue occurred as compared to control untreated SHRs. Titanium dioxide nanoparticles were quantified in the heart tissue although without definite accumulation as revealed by particle-induced X-ray emission and ultrastructural analysis. CONCLUSIONS: The co-morbidity of hypertension and inhaled nanoparticles induces irreversible hemodynamic impairment associated with cardiac structural damage potentially leading to heart failure. The time-dependence of exposure indicates a non-return point that needs to be taken into account in hypertensive subjects daily exposed to nanoparticles.

Non-invasive techniques to assess restrictive lung disease in workers exposed to free crystalline silica.

OBJECTIVES: To compare the reliability of spirometry and body plethysmography in detecting restrictive lung disease in clay excavation workers exposed to free crystalline silica (FCS). The exhaled breath condensate (EBC) biomarkers of oxidative stress were also assessed in order to evaluate early lung damage. METHODS: The study involved 62 workers (58 males and 4 females) at a company that extracts and processes clay. RESULTS: Body plethysmography (total lung capacity below the lower normal limit) and spirometry respectively indicated restrictive pattern prevalence rates of 22.6% and 1.6%. EBC 4-hydroxynonenale levels were not sufficiently sensitive to highlight a restrictive deficit, but did distinguish low and high rates of occupational exposure. There was no correlation between plethysmography values and the intensity or duration of exposure. CONCLUSIONS: Only one out of 14 cases of restrictive deficit diagnosed on the basis of body plethysmography values was also identified by means of spirometry. This finding supports the need to use body plethysmography in the health surveillance of clay workers exposed to FCS.

Methy-sens Comet assay and DNMTs transcriptional analysis as a combined approach in epigenotoxicology.

Epigenotoxicology needs simple and fast tools to assess xenobiotic epigenetic load. This work proposes a comet assay modification designed to detect global methylation changes (Methy-sens Comet) through enzymatic digestion with two restriction enzymes (HpaII, MspI). In the methylation-sensitive protocol tested for repeatability on A549 cells, nickel chloride induced hypermethylation and decitabine-induced hypomethylation. A concomitant assessment of DNA methyltransferases (DNMTs) genes transcriptional levels has been performed, to implement a multifunctional approach to epigenotoxicology. Methy-sens Comet showed a general good repeatability and sensitivity to methylation changes while DNMTs transcriptional levels granted additional proof of xenobiotic-induced impairment of methylome maintenance.

Quantification of 3-MCPD and its mercapturic metabolite in human urine: validation of an LC-MS-MS method and its application in the general population.

A new method for the simultaneous quantitative determination in human urine of 3-monochloropropane-1,2-diol (3-MCPD), a toxic food contaminant, and its metabolite, 2,3-dihydroxypropyl mercapturic acid (DHPMA), was developed and validated. After urine dilution, the analytes were separated on an Atlantis®dC18 column and quantified by liquid chromatography-tandem mass spectrometry using isotopically labelled internal standards. The limits of quantification (S/N = 10) were 1.90 and 2.21 µg/L for 3-MCPD and DHPMA, respectively. Intra- and inter-day precision were lower than 6 % for each compound. Matrix effects were evaluated. Due to the high sensitivity and good accuracy of the method, 3-MCPD and DHPMA were found in 67 and 100 % of urine samples of healthy subjects, respectively.

Asbestos and smoking as risk factors for idiopathic retroperitoneal fibrosis: a case-control study.

BACKGROUND: Idiopathic retroperitoneal fibrosis (RPF) is a rare disease. Asbestos exposure has been proposed as a risk factor for idiopathic RPF. OBJECTIVE: To investigate the role of asbestos and other occupational agents (such as silica, metals, and organic solvents), as well as environmental agents (such as smoking), and their interactions as potential risk factors for idiopathic RPF. DESIGN: Case-control study. SETTING: National referral hospital for idiopathic RPF. PATIENTS: 90 patients with idiopathic RPF and 270 control participants matched for age, sex, and region of residency. MEASUREMENTS: Occupational history was obtained using structured questionnaires administered by blinded specialists in occupational medicine. Exposure to nonoccupational agents and presence of diseases that were potentially predisposing to idiopathic RPF were assessed through patient interviews and examination of medical records. RESULTS: A history of asbestos exposure was associated with idiopathic RPF (odds ratio [OR], 4.22 [95% CI, 2.14 to 8.33]). Both current smoking (OR, 3.21 [CI, 1.46 to 7.07]) and former smoking (OR, 2.93 [CI, 1.39 to 6.14]) were more prevalent among patients than among those who never smoked. A multiplicative effect was found between tobacco smoke and both occupational asbestos exposure (OR, 12.04 [CI, 4.32 to 38.28]) and extraoccupational asbestos exposure (OR, 8.42 [CI, 2.77 to 30.58]). LIMITATION: Retrospective, questionnaire-based assessment of occupational exposure. CONCLUSION: Exposure to asbestos and tobacco smoke resulted in strong risk factors for idiopathic RPF. Coexposure to asbestos and smoke had a multiplicative effect on risk compared with single exposure. PRIMARY FUNDING SOURCE: None.

Titanium dioxide nanoparticles promote arrhythmias via a direct interaction with rat cardiac tissue.

BACKGROUND: In light of recent developments in nanotechnologies, interest is growing to better comprehend the interaction of nanoparticles with body tissues, in particular within the cardiovascular system. Attention has recently focused on the link between environmental pollution and cardiovascular diseases. Nanoparticles <50 nm in size are known to pass the alveolar-pulmonary barrier, enter into bloodstream and induce inflammation, but the direct pathogenic mechanisms still need to be evaluated. We thus focused our attention on titanium dioxide (TiO2) nanoparticles, the most diffuse nanomaterial in polluted environments and one generally considered inert for the human body. METHODS: We conducted functional studies on isolated adult rat cardiomyocytes exposed acutely in vitro to TiO2 and on healthy rats administered a single dose of 2 mg/Kg TiO2 NPs via the trachea. Transmission electron microscopy was used to verify the actual presence of TiO2 nanoparticles within cardiac tissue, toxicological assays were used to assess lipid peroxidation and DNA tissue damage, and an in silico method was used to model the effect on action potential. RESULTS: Ventricular myocytes exposed in vitro to TiO2 had significantly reduced action potential duration, impairment of sarcomere shortening and decreased stability of resting membrane potential. In vivo, a single intra-tracheal administration of saline solution containing TiO2 nanoparticles increased cardiac conduction velocity and tissue excitability, resulting in an enhanced propensity for inducible arrhythmias. Computational modeling of ventricular action potential indicated that a membrane leakage could account for the nanoparticle-induced effects measured on real cardiomyocytes. CONCLUSIONS: Acute exposure to TiO2 nanoparticles acutely alters cardiac excitability and increases the likelihood of arrhythmic events.

Plasma and EBC microRNAs as early biomarkers of non-small-cell lung cancer.

Lung cancer is a major cause of death in Western countries. Current screening methods are invasive and still lead to a high percentage of false positives. There is, therefore, a need to find biomarkers that increase the probability of detecting lung cancer early. MicroRNAs (miRNAs) are stable molecules in blood plasma and exhaled breath condensate (EBC). We quantified miRNA-21 and miRNA-486 expression from plasma and EBC samples from patients with a diagnosis of non-small-cell lung cancer (NSCLC) and controls. miRNA-21 was significantly higher in plasma and in EBC of the NSCLC patients and miRNA-486 was significantly lower. This difference indicates a significantly improved diagnostic value, and suggests that these miRNAs could be clinically used as a first-line screening test in high-risk subjects.

[Biomarkers of effect and susceptibility to low doses of benzene]. / Indicatori di effetto e di suscettibilità alle basse dosi di benzene.

Current occupational exposure levels to benzene are reduced by three orders of magnitudo (from ppm to ppb) as compared to the past. As benzene toxicity is related to its biotransformation and bioactivation pathways seem to be more active at lower exposure levels, observed effects could be higher than expected. Although the genetic polymorphisms of relevant and functional metabolic enzymes are implied in the modulation of either the risk of adverse effects [myeloperoxidase and NAD(P)H:quinone oxidoreductase] or of the biomarkers of internal dose (glutathione S-transferases M1-1, T1-1, A1-1), they are not appliable as biomarkers of susceptibility. Among biomarkers of early effect, only the longitudinal monitoring of blood cell count seems suitable to be applied in health surveillance protocols, whereas the use of biomarkers of genotoxic effect at current exposure levels is at the present not supported by literature data.