A guide to mycetisms: A toxicological and preventive overview.

Fungi are often considered a delicacy and are primarily cultivated and harvested, although numerous species are responsible for intoxication due to toxin content. Foodborne diseases are a significant public health concern, causing approximately 420 000 deaths and 600 million morbidities yearly, of which mushroom poisoning is one of the leading causes. Epidemiological data on non-cultivated mushroom poisoning in individual countries are often unrepresentative, as intoxication rarely requires emergency intervention. On the other hand, the lack of specialist knowledge among medical personnel about the toxicological manifestations of mushroom consumption may result in ineffective therapeutic interventions. This work aims to provide an easy-to-consult and wide-ranging tool useful for better understanding the variability of mushroom intoxications, the associated symptoms, and the main treatments for the most severe cases, given the absence of a complete species mapping tool toxic. Moreover, we establish an effective collection network that describes the incidence of mushroom poisonings by reporting the species and associated toxicological manifestations for each case. In conclusion, we highlight the need to establish appropriate primary prevention interventions, such as training the affected population and increasing consultancy relationships between mycological experts and specialised healthcare personnel.

We propose a review of the literature that describes the main syndromes resulting from the consumption of toxic fungal species, reporting symptoms and clinical manifestations, latency times and, where possible, diagnostic tools for recognising the species involved and interventions to be carried out.

UVB-Aged Microplastics and Cellular Damage: An in Vitro Study.

Plastics are synthetic organic compounds whose widespread use generates enormous waste. Different processes, such as mechanical abrasion, microbiological activity, and UVB irradiation, can fragment the plastic material and generate microplastics (MPs). MPs are ubiquitous, and various organisms, including humans, can ingest or inhale them, with potential adverse health effects. The differences between UV-aged and virgin particles were studied to evaluate the genotoxic damage and oxidative stress induced by polystyrene MPs with 1 and 5 µm sizes on the monocyte-like cell line (THP-1). Fourier transform infrared spectroscopy and Ζ-potential measurements were used to characterise MP particles after UVB exposure. Cells exposed to MPs show a widespread change in the cellular environment with the generation of reactive oxidative species (ROS), as indicated by the increased malondialdehyde level. The occurrence of genotoxic damage is correlated to the smaller size and ageing state of the MPs. The biochemical and genomic alterations observed in this in vitro study suggest that MPs, ubiquitous pollutants, following natural degradation and oxidation processes can cause various adverse effects on the health of the exposed population, making it necessary to carry out further studies to better define the real risk.

Growth and decline of the COVID-19 epidemic wave in Italy from March to June 2020.

March 21, 2020 was the ridgeline between the growth of the coronavirus disease 2019 (COVID-19) epidemic wave in Italy and the start of its decline. We analyzed the epidemic patterns from March 1 to June 30. There was a progressive drop of cases from March (104,710) to April (94,888), May (25,705) and June (8110). Likewise, after a slight increase of deaths in April (14,804) compared to March (12,396), a considerable decline occurred in May (5170) and June (1464). Doubling times of cumulative cases grew from 2 to 6 days until March 20 to 2 weeks up to April 5, and thereafter no further doubling occurred until June 30. There was a striking North-South gradient of both cases and deaths. At the end of June, the nine Northern Italian regions or provinces, five central regions, and seven southern regions had contributed to the 81.1%, 12.4%, and 6.5% of the 240,578 national cases, respectively. Lombardy, the most populous region, was by far the most heavily affected one, accounting for the 39.0% of the national cases occurring over the analyzed 4-month period. However, in relative terms, it was preceded by Aosta Valley, the least populous region, less than 1% of the population of both regions having been affected by cases of COVID-19. The curves showing the ratio of daily cumulative cases and deaths to those of the previous day tended to flatten with time by approaching the zero growth but without reaching it, which documents a persisting circulation of severe acute respiratory syndrome coronavirus 2 in the Italian territory.

Rationale for the use of N-acetylcysteine in both prevention and adjuvant therapy of COVID-19.

COVID-19 may cause pneumonia, acute respiratory distress syndrome, cardiovascular alterations, and multiple organ failure, which have been ascribed to a cytokine storm, a systemic inflammatory response, and an attack by the immune system. Moreover, an oxidative stress imbalance has been demonstrated to occur in COVID-19 patients. N- Acetyl-L-cysteine (NAC) is a precursor of reduced glutathione (GSH). Due to its tolerability, this pleiotropic drug has been proposed not only as a mucolytic agent, but also as a preventive/therapeutic agent in a variety of disorders involving GSH depletion and oxidative stress. At very high doses, NAC is also used as an antidote against paracetamol intoxication. Thiols block the angiotensin-converting enzyme 2 thereby hampering penetration of SARS-CoV-2 into cells. Based on a broad range of antioxidant and anti-inflammatory mechanisms, which are herein reviewed, the oral administration of NAC is likely to attenuate the risk of developing COVID-19, as it was previously demonstrated for influenza and influenza-like illnesses. Moreover, high-dose intravenous NAC may be expected to play an adjuvant role in the treatment of severe COVID-19 cases and in the control of its lethal complications, also including pulmonary and cardiovascular adverse events.

Micronuclei in Fish Erythrocytes as Genotoxic Biomarkers of Water Pollution: An Overview.

Freshwater and marine water bodies receive chemical contaminants from industrial, agricultural, urban, and domestic wastes. Eco-genotoxicity assays are useful tools to assess the cumulative genotoxicity of these pollutants. Fish are suitable indicators for biomonitoring of mutagenic and carcinogenic pollution.In this review, we present a complete overview of the studies performed so far using the micronucleus test in peripheral erythrocytes of fish exposed to polluted water. We have listed all the species of fish used and the geographical distribution of the investigations. We have analyzed and discussed all technical aspects of using this test in fish, as well as the advantages and disadvantages of the different experimental protocols. We have reported the results of all studies. This assay has become, for years, one of the simplest, fastest, and most cost-effective for assessing genotoxic risk in aquatic environments. However, there are still several factors influencing the variability of the results. Therefore, we have given indications and suggestions to achieve a standardization of experimental procedures and ensure uniformity of future investigations.

Modulation of smoke-induced DNA and microRNA alterations in mouse lung by licofelone, a triple COX-1, COX-2 and 5-LOX inhibitor.

Chronic inflammation plays a crucial role in the carcinogenesis process and, in particular, in smoking-related carcinogenesis. Therefore, anti-inflammatory agents provide an interesting perspective in the prevention of smoking-associated cancers. Among nonsteroidal anti-inflammatory drugs (NSAIDs), licofelone is a triple inhibitor of both cyclooxygenases (COX-1 and COX-2) and of 5-lipooxygenase (5-LOX) that has shown some encouraging results in cancer prevention models. We previously showed that the dietary administration of licofelone, starting after weanling, to Swiss H mice exposed for 4 months to mainstream cigarette smoke since birth attenuated preneoplastic lesions of inflammatory nature in both lung and urinary tract, and had some effects on the yield of lung tumors at 7.5 months of age. The present study aimed at evaluating the early modulation by licofelone of pulmonary DNA and RNA alterations either in smoke-free or smoke-exposed H mice after 10 weeks of exposure. Licofelone protected the mice from the smoke-induced loss of body weight and significantly attenuated smoke-induced nucleotide alterations by decreasing the levels of bulky DNA adducts and 8-hydroxy-2'-deoxyguanosine in mouse lung. Moreover, the drug counteracted dysregulation by smoke of several pulmonary microRNAs involved in stress response, inflammation, apoptosis, and oncogene suppression. However, even in smoke-free mice administration of the drug had significant effects on a broad panel of microRNAs and, as assessed in a subset of mice used in a parallel cancer chemoprevention study, licofelone even enhanced the smoke-induced systemic genotoxic damage after 4 months of exposure. Therefore, caution should be paid when administering licofelone to smokers for long periods.

Epidemiological trends of COVID-19 epidemic in Italy over March 2020: From 1000 to 100 000 cases.

The coronavirus disease 2019 epidemic started in Italy by the end of January 2020 and, after 1 month, it affected 1049 persons. Based on the Italian Ministry of Health data, we reconstructed the daily course of virus-positive cases and deaths over March 2020 for the whole of Italy, 19 regions and 2 provinces. From 29 February to 31 March, there was a 100.9-fold increase in the cumulative number of cases and a 428.6-fold increase in the number of deaths in Italy. When plotted on a semilogarithmic scale, the curves tended to diverge from linearity with 23%, 16%, and 7% average daily increases during the three decades of March. Similarly, the number of deaths decreased from an average daily growth of 19% over the second decade to 10% over the third decade. The correlation coefficients relating the days to cases or deaths over each one of the three decades approached unity. As inferred from the equations of the regression lines relative to the three decades, the doubling times of cases were 3.4, 5.1, and 9.6 days, respectively. The doubling times of deaths over the second and third decades were 4.9 and 7.0 days, respectively. There was a broad geographic variability, with a striking gradient from the North, where 40.8% of cases and 57.9% of deaths occurred in Lombardy, to the South. On the whole, over March there was a trend to epidemic growth decline but the time for the end of the epidemic will depend on a variety of factors and, at present, it is unpredictable.

Carcinogenic response and other histopathological alterations in mice exposed to cigarette smoke for varying time periods after birth.

In spite of the outstanding role of tobacco smoking in human carcinogenesis, it is difficult to reproduce its effects in experimental animals. Based on the knowledge that a variety of mechanisms account for a higher susceptibility to carcinogens early in life, we have developed a murine model in which mainstream cigarette smoke becomes convincingly carcinogenic. The standard model involves exposure to smoke for 4 months, starting after birth, followed by an additional 3-4 months in filtered air. We evaluated herein the time- and dose-dependent response, at 7.5 months of life, of Swiss H mice that had been exposed to smoke for either 1, 2 or 4 months after birth. A one-month exposure, corresponding to a period of intense alveolarization, was sufficient to induce most inflammatory, degenerative and preneoplastic pulmonary lesions, including emphysema and alveolar epithelial hyperplasia, blood vessel proliferation and hemangiomas, reflecting an early proangiogenic role of smoking, and microadenomas bearing ki-67-positive proliferating cells as well as urinary bladder epithelial hyperplasia. Two months of exposure were needed to induce pulmonary adenomas and urinary bladder papillomas in males only, which highlights a protective role of estrogens in urinary bladder carcinogenesis. Four months, which in humans would correspond to the postnatal period, puberty, adolescence and early adulthood, were needed to induce other lesions, including tubular epithelial hyperplasia of kidney, bronchial epithelial hyperplasia and especially pulmonary malignant tumors. These findings highlight the concept that preneoplastic and neoplastic lesions occurring in adulthood can be induced by exposure to smoke early in life.

Aspirin abrogates impairment of mammary gland differentiation induced by early in life second-hand smoke in mice.

Epidemiological studies show that there is limited evidence that tobacco smoking causes breast cancer in humans. In rodents, many tobacco smoke chemicals cause mammary gland tumors. This study evaluated the mammary gland differentiation in mice exposed to environmental cigarette smoke (ECS), using 3R4F Kentucky reference cigarettes, starting after birth and continuing daily for 10 weeks (total particulate exposure 95 mg/m3; CO 610 ppm). We also analyzed the effects of oral administration of non-steroidal anti-inflammatory drugs (NSAIDs), aspirin (1600 mg/kg) or naproxen (320 mg/kg), on mammary gland differentiation, either in unexposed or ECS-exposed mice. The ECS exposure caused delay of mammary glands development. We speculate that this delay may result from aryl hydrocarbon receptor (AHR) signaling activation, which has an antiestrogenic effect and crosstalk to the estrogen metabolism pathway. Similarly, naproxen impaired gland differentiation in unexposed and ECS-exposed mice, while aspirin hindered its development only in unexposed mice. The lack of differentiation induced by the NSAIDs could be explained by their antiestrogenic effect through inhibition of aldo-keto reductases. In ECS-exposed animals, aspirin induced intense lobular formation, which could indicate that aspirin is counteracting the AHR signaling induced by ECS. Based on the differentiation induced by aspirin in ECS-exposed animals, we postulate that these mice would be less susceptible to mammary carcinogenesis. Our results suggest that exposure to smoke at an early age impairs the development of the mammary gland, thus resulting in a longer period of susceptibility and increased risk of breast cancer. However, addition of aspirin can abrogate this effect.

Reduction of hexavalent chromium by fasted and fed human gastric fluid. I. Chemical reduction and mitigation of mutagenicity.

Evaluation of the reducing capacity of human gastric fluid from healthy individuals, under fasted and fed conditions, is critical for assessing the cancer hazard posed by ingested hexavalent chromium [Cr(VI)] and for developing quantitative physiologically-based pharmacokinetic models used in risk assessment. In the present study, the patterns of Cr(VI) reduction were evaluated in 16 paired pre- and post-meal gastric fluid samples collected from 8 healthy volunteers. Human gastric fluid was effective both in reducing Cr(VI), as measured by using the s-diphenylcarbazide colorimetric method, and in attenuating mutagenicity in the Ames test. The mean (±SE) Cr(VI)-reducing ability of post-meal samples (20.4±2.6µgCr(VI)/mL gastric fluid) was significantly higher than that of pre-meal samples (10.2±2.3µgCr(VI)/mL gastric fluid). When using the mutagenicity assay, the decrease of mutagenicity produced by pre-meal and post-meal samples corresponded to reduction of 13.3±1.9 and 25.6±2.8µgCr(VI)/mL gastric fluid, respectively. These data are comparable to parallel results conducted by using speciated isotope dilution mass spectrometry. Cr(VI) reduction was rapid, with >70% of total reduction occurring within 1min and 98% of reduction is achieved within 30min with post-meal gastric fluid at pH2.0. pH dependence was observed with decreasing Cr(VI) reducing capacity at higher pH. Attenuation of the mutagenic response is consistent with the lack of DNA damage observed in the gastrointestinal tract of rodents following administration of ≤180ppm Cr(VI) for up to 90days in drinking water. Quantifying Cr(VI) reduction kinetics in the human gastrointestinal tract is necessary for assessing the potential hazards posed by Cr(VI) in drinking water.

Selective inhibition by aspirin and naproxen of mainstream cigarette smoke-induced genotoxicity and lung tumors in female mice.

The role of nonsteroidal anti-inflammatory drugs (NSAIDs) in smoke-related lung carcinogenesis is still controversial. We have developed and validated a murine model for evaluating the tumorigenicity of mainstream cigarette smoke (MCS) and its modulation by chemopreventive agents. In the present study, the protective effects of the nonselective cyclooxygenase inhibitors aspirin and naproxen were investigated by using a total of 277 Swiss H neonatal mice of both genders. Groups of mice were exposed whole-body to MCS during the first 4 months of life, followed by an additional 3.5 months in filtered air in order to allow a better growth of tumors. Aspirin (1600 mg/kg diet) and naproxen (320 mg/kg diet) were given after weanling until the end of the experiment. After 4 months of exposure, MCS significantly enhanced the frequency of micronucleated normochromatic erythrocytes in the peripheral blood of mice, and naproxen prevented such systemic genotoxic damage in female mice. After 7.5 months, exposure of mice to MCS resulted in the formation of lung tumors, both benign and malignant, and in several other histopathological lesions detectable both in the respiratory tract and in the urinary tract. Aspirin and, even more sharply, naproxen significantly inhibited the formation of lung tumors in MCS-exposed mice, but this protective effect selectively occurred in female mice only. These results lend support to the views that estrogens are involved in smoke-related pulmonary carcinogenesis and that NSAIDs have antiestrogenic properties. The two NSAIDs proved to be safe and efficacious in the experimental model used.

Modulation by aspirin and naproxen of nucleotide alterations and tumors in the lung of mice exposed to environmental cigarette smoke since birth.

Chemoprevention provides an important strategy for cancer control in passive smokers. Due to the crucial role played by smoke-related chronic inflammation in lung carcinogenesis, of special interest are extensively used pharmacological agents, such as nonsteroidal anti-inflammatory drugs (NSAIDs). We evaluated the ability of aspirin and naproxen, inhibitors of both cyclooxygenase-1 and cyclooxygenase -2, to modulate environmental cigarette smoke (ECS)-induced lung carcinogenesis in A/J mice of both genders. Based on a subchronic toxicity study in 180 postweaning mice, we used 1600 mg/kg diet aspirin and 320 mg/kg diet naproxen. In the tumor chemoprevention study, using 320 mice, exposure to ECS started soon after birth and administration of NSAIDs started after weaning. At 10 weeks of life, the NSAIDs did not affect the presence of occult blood in feces. As assessed in a subset of 40 mice, bulky DNA adducts and 8-hydroxy-2'-deoxyguanosine levels were considerably increased in ECS-exposed mice and, irrespective of gender, both NSAIDs remarkably inhibited these nucleotide alterations. After exposure for 4 months followed by 5 months in filtered air, ECS induced a significant increase in the yield of surface lung tumors, the 43.7% of which were adenomas and the 56.3% were adenocarcinomas. Oct-4 (octamer-binding transcription factor 4), a marker of cell stemness, was detected in some adenocarcinoma cells. The NAIDs attenuated the yield of lung tumors, but prevention of ECS-induced lung adenomas was statistically significant only in female mice treated with aspirin, which supports a role for estrogens in ECS-related lung carcinogenesis and highlights the antiestrogenic properties of NSAIDs.

Assay of lapatinib in murine models of cigarette smoke carcinogenesis.

Lapatinib, a dual tyrosine kinase inhibitor targeting the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER-2), is prescribed for the treatment of patients with metastatic breast cancer overexpressing HER-2. Involvement of this drug in pulmonary carcinogenesis has been poorly investigated. We used murine models suitable to evaluate cigarette smoke-related molecular and histopathological alterations. A total of 481 Swiss H mice were used. The mice were exposed to mainstream cigarette smoke (MCS) during the first four months of life. After 10 weeks, MCS caused an elevation of bulky DNA adducts, oxidative DNA damage and an extensive downregulation of microRNAs in lung. After four months, an increase in micronucleus frequency was observed in peripheral blood erythrocytes. After 7.5 months, histopathological alterations were detected in the lung, also including benign tumors and malignant tumors, and in the urinary tract. A subchronic toxicity study assessed the non-toxic doses of lapatinib, administered daily with the diet after weaning. After 10 weeks, lapatinib significantly attenuated the MCS-related nucleotide changes and upregulated several low-intensity microRNAs in lung. The drug poorly affected the MCS systemic genotoxicity and had modest protective effects on MCS-induced preneoplastic lesions in lung and kidney, when administered under conditions that temporarily mimicked interventions either in current smokers or ex-smokers. On the other hand, it caused some toxicity to the liver. Thus, on the whole, lapatinib appears to have a low impact in the smoke-related lung carcinogenesis models used, especially in terms of tumorigenic response.

Rationale and approaches to the prevention of smoking-related diseases: overview of recent studies on chemoprevention of smoking-induced tumors in rodent models.

Tobacco smoke plays a dominant role in the epidemiology of lung cancer, cancer at other sites, and a variety of other chronic diseases. It is the leading cause of death in developed countries, and the global burden of cancer is escalating in less developed regions. For a rational implementation of strategies exploitable for the prevention smoking-related diseases, it is crucial to elucidate both the mechanisms of action of cigarette smoke and the protective mechanisms of the host organism. The imperative primary prevention goal is to avoid any type of exposure to smoke. Epidemiological studies have shown that a decrease in the consumption of cigarettes can be successful in attenuating the epidemic of lung cancer in several countries. Chemoprevention by means of dietary and/or pharmacological agents provides a complementary strategy aimed at decreasing the risk of developing smoking-associated diseases in addicted current smokers, who are unable to quit smoking, and especially in involuntary smokers and ex-smokers. The availability of new animal models that are suitable to detect the carcinogenicity of cigarette smoke and to assess the underlying molecular mechanisms provides new tools for evaluating both safety and efficacy of putative chemopreventive agents.

The Spread of Mycobacterium chimaera from Heater-Cooler Units and Infection Risk in Heart Surgery: Lessons from the Global Outbreak?

Mycobacterium chimaera (MC), a member of the Mycobacterium avium complex, can cause infections in patients after open-heart surgery due to contaminated heater-cooler units (HCUs). The transmission route of HCU-related MC infection is non-inhalational, and infection can occur in patients without previously known immune deficiency. Patients may develop endocarditis of the prosthetic valve, infection of the vascular graft, and/or manifestations of disseminated mycobacterial infection (splenomegaly, arthritis, hepatitis, nephritis, myocarditis, etc.). MC infections have serious outcomes (30-50% recurrence rate, 20-67% mortality rate). In 2015, an international outbreak of M. chimaera infections among patients undergoing cardiothoracic surgeries was associated with exposure to contaminated LivaNova 3T HCUs (formerly Stöckert 3T heater-cooler system, London, United Kingdom). In response to the global outbreak, many international agencies have issued directives and recommendations in order to reduce the risk of MC infection in cardiac surgery. Whole-genome sequencing (WGS) technology can be used to describe the global spread and dynamics of MC infections, to characterize local outbreaks, and also to identify sources of infection in hospital settings. In order to minimize the risk of contamination of HCUs and reduce the risk of patient infection, it is imperative that healthcare facilities establish a program of regular cleaning and disinfection maintenance procedures as well as monitoring of the water used and the air in the operating room, in accordance with the manufacturer's procedure.

MicroRaman spectroscopy detects the presence of microplastics in human urine and kidney tissue.

There is a growing concern within the medical community about the potential burden of microplastics on human organs and tissues. In this study, we investigated by microRaman spectroscopy the presence of microplastics in human kidneys and urine. Moreover, an open-access software was developed and validated for the project, which enabled the comparison between the investigated spectra and a self-created spectral database, thus enhancing the ability to characterize polymers and pigments in biological matrices. Healthy portions of ten kidneys obtained from nephrectomies, as well as ten urine samples from healthy donors were analyzed: 26 particles in both kidney and urine samples were identified, with sizes ranging from 3 to 13 µm in urine and from 1 to 29 µm in kidneys. The most frequently determined polymers are polyethylene and polystyrene, while the most common pigments are hematite and Cu-phthalocyanine. This preclinical study proves the presence of microplastics in renal tissues and confirms their presence in urine, providing the first evidence of kidney microplastics deposition in humans.

DNA damage in exfoliated cells and histopathological alterations in the urinary tract of mice exposed to cigarette smoke and treated with chemopreventive agents.

Cigarette smoke (CS) is convincingly carcinogenic in mice when exposure starts at birth. We investigated the induction and modulation of alterations in the kidney and urinary bladder of CS-exposed mice. A total of 484 strain H Swiss mice were either sham-exposed or exposed since birth to mainstream CS (MCS) for 4 months. Dietary agents, including myo-inositol, suberoylanilide hydroxamic acid, bexarotene, pioglitazone and a combination of bexarotene and pioglitazone, were administered after weaning. Comet analyses showed that, after 2 and 4 months, MCS causes DNA damage in exfoliated urothelial cells, which can be prevented by myo-inositol and the peroxisome proliferator-activated receptor-γ ligand pioglitazone. After 7 months, the 17.6% of MCS-exposed male mice exhibited lesions of the urinary tract versus the 6.1% of sham-exposed mice, which emphasizes the role of sex hormones in urinary tract carcinogenesis. Myo-inositol and the RXR-specific retinoid bexarotene did not affect these alterations. The histone deacetylase inhibitor suberoylanilide hydroxamic acid (Vorinostat) increased the incidence of kidney epithelium hyperplasia. Pioglitazone significantly enhanced the incidence of kidney lesions as compared with mice exposed to MCS only, indicating possible adverse effects of this antidiabetic drug, which were lost upon combination with bexarotene according to a combined chemoprevention strategy. RXR is a heterodymeric partner for peroxisome proliferator-activated receptor-γ, thereby modulating the expression of multiple target genes. In conclusion, there is contrast between the ability of pioglitazone to inhibit DNA damage in exfoliated cells and the alterations induced in the urinary tract of MCS-exposed mice, suggesting the occurrence of non-genotoxic mechanisms for this drug.

Relationships between pulmonary micro-RNA and proteome profiles, systemic cytogenetic damage and lung tumors in cigarette smoke-exposed mice treated with chemopreventive agents.

Assessing the correlation between molecular endpoints and cancer induction or prevention aims at validating the use of intermediate biomarkers. We previously developed murine models that are suitable to detect both the carcinogenicity of mainstream cigarette smoke (MCS) and the induction of molecular alterations. In this study, we used 931 Swiss mice in two parallel experiments and in a preliminary toxicity study. The chemopreventive agents included vorinostat, myo-inositol, bexarotene, pioglitazone and a combination of bexarotene and pioglitazone. Pulmonary micro-RNAs and proteins were evaluated by microarray analyses at 10 weeks of age in male and female mice, either unexposed or exposed to MCS since birth, and either untreated or receiving each one of the five chemopreventive regimens with the diet after weaning. At 4 months of age, the frequency of micronucleated normochromatic erythrocytes was evaluated. At 7 months, the lungs were subjected to standard histopathological analysis. The results showed that exposure to MCS significantly downregulated the expression of 79 of 694 lung micro-RNAs (11.4%) and upregulated 66 of 1164 proteins (5.7%). Administration of chemopreventive agents modulated the baseline micro-RNA and proteome profiles and reversed several MCS-induced alterations, with some intergender differences. The stronger protective effects were produced by the combination of bexarotene and pioglitazone, which also inhibited the MCS-induced clastogenic damage and the yield of malignant tumors. Pioglitazone alone increased the yield of lung adenomas. Thus, micro-RNAs, proteins, cytogenetic damage and lung tumors were closely related. The molecular biomarkers contributed to evaluate both protective and adverse effects of chemopreventive agents and highlighted the mechanisms involved.

Genotoxic damage in the oral mucosa cells of subjects carrying restorative dental fillings.

A large proportion of the population carries restorative dental fillings containing either classic Hg-based amalgams and/or the more frequently used methacrylates. Both Hg- and resin-based materials have been shown to be released into the buccal cavity and to be spread systemically. In addition, they induce toxic and genotoxic alterations in experimental test systems. Using the comet assay, we previously demonstrated that circulating lymphocytes of subjects with dental fillings have an increased DNA damage. Here, we analyzed the oral mucosa cells of 63 young subjects of both genders, by using both the comet assay and the micronucleus (MN) test and by monitoring cell death markers. The results obtained show that both amalgams and resin-based composite fillings can induce genotoxic damage in human oral mucosa cells, as convincingly and dose-dependently inferred from the results of the MN test and, more marginally, from comet assay data. Lifestyle variables, also including alcohol intake and smoking habits, did not affect the genotoxic response and did not act as confounding factors. Thus, we provide unequivocal evidence for the genotoxicity of both amalgams and resin-based dental fillings in humans not only by testing circulating lymphocytes but also by analyzing oral mucosa cells. These findings are of particular relevance due to the circumstance that subjects with restorative materials are exposed continuously and for long periods of time.

Oxidative stress in the lung of mice exposed to cigarette smoke either early in life or in adulthood.

Birth and early life stages are critical periods characterized by severe alterations of the redox balance and by "physiological" genomic changes in lung cells, which may be responsible for cancer and other diseases in adulthood. Oxidative stress is a major mechanism accounting for the carcinogenicity of cigarette smoke (CS), which becomes more potently carcinogenic in mice when exposure starts at birth and continues early in life. We compared herewith a variety of end-points related to oxidative stress, mitochondrial alterations, and cell turnover in the lung of Swiss H mice, either sham-exposed or CS-exposed for 4 weeks, starting either at birth or at 4 months of age. The results showed that the physiological levels of certain end-points are affected by age. In fact, the baseline proportion of hypodiploid cells and the mitochondrial potential and mass were higher in adults, whereas 8-hydroxy-2'-deoxyguanosine (8-oxo-dGuo) levels, the proportion of necrotic cells, and the extent of autophagy were higher early in life. Adult mice were more responsive to CS by increasing the proportion of necrotic cells and of cells in S/G2 phase, whereas young mice maintained a high extent of autophagy, exhibited a greater increase of lipid peroxidation products and 8-oxo-dGuo levels, and had a higher frequency of micronucleated cells. In addition, exposure to CS affected the mitochondrial potential/mass, especially in young mice. In conclusion, these data provide evidence that oxidative stress and the resulting DNA damage provide a major contribution to the high susceptibility of mice to CS early in life.