Oxidative stress and DNA damage in agricultural workers after exposure to pesticides.

BACKGROUND: Recent epidemiological studies on workers describe that exposure to pesticides can induce oxidative stress by increased production of free radicals that can accumulate in the cell and damage biological macromolecules, for example, RNA, DNA, DNA repair proteins and other proteins and/or modify antioxidant defense mechanisms, as well as detoxification and scavenger enzymes. This study aimed to assess oxidative stress and DNA damage among workers exposed to pesticides. METHODS: For this purpose, 52 pesticide exposed workers and 52 organic farmers were enrolled. They were assessed: the pesticide exposure, thiobarbituric acid reactive substances (TBARS), total glutathione (TG), oxidized glutathione levels (GSSG), and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), levels. RESULTS: Correlation between pesticide exposure was positively associated with high TBARS and 8-oxodG levels (p <  0.001). A negative association was founded with TG and GSSG and pesticide exposure. CONCLUSIONS: The present investigation results seem to indicate a mild augment in oxidative stress associated with pesticide exposure, followed by an adaptive response to increase the antioxidant defenses to prevent sustained oxidative adverse effects stress.

Defense and protection mechanisms in lung exposed to asbestiform fiber: the role of macrophage migration inhibitory factor and heme oxygenase-1.

Fluoro-edenite (FE), an asbestiform fiber, is responsible for many respiratory pathologies: chronic obstructive diseases, pleural plaques, fibrosis, and malignant mesothelioma. Macrophage migration inhibitory factor (MIF) is one of the first cytokines produced in response to lung tissue damage. Heme oxygenase-1 (HO-1) is a protein with protective effects against oxidative stress. It is up regulated by several stimuli including pro-inflammatory cytokines and factors that promote oxidative stress. In this research, the in vivo model of sheep lungs naturally exposed to FE was studied in order to shed light on the pathophysiological events sustaining exposure to fibers, by determining immunohistochemical lung expression of MIF and HO-1. Protein levels expression of HO-1 and MIF were also evaluated in human primary lung fibroblasts after exposure to FE fibers in vitro. In exposed sheep lungs, MIF and HO-1 immunoexpression were spread involving the intraparenchymal stroma around bronchioles, interstitium between alveoli, alveolar epithelium and macrophages. High MIF immunoexpression prevails in macrophages. Similar results were obtained in vitro, but significantly higher values were only detected for HO-1 at concentrations of 50 and 100 µg/mL of FE fibers. MIF and HO-1 expressions seem to play a role in lung self-protection against uncontrolled chronic inflammation, thus counteracting the strong link with cancer development, induced by exposure to FE. Further studies will be conducted in order to add more information about the role of MIF and HO-1 in the toxicity FE-induced.

MMP-7 and MMP-9 are overexpressed in the synovial tissue from severe temporomandibular joint dysfunction.

Matrix metalloproteinases (MMPs) are tissue-enzymes that play a key role during the remodeling process, such as in inflammatory diseases. MMP-7 and MMP-9 have been shown to be implicated in extracellular matrix homeostasis and in joint disc remodeling. The objective of this study was to determine the relation of MMP-7 and MMP-9 expression with severe temporomandibular joint dysfunction, in particular with anterior disk displacement without reduction (ADDwoR), using an immunohistochemical approach. Therefore, twenty human temporomandibular synovia in the test group and ten in the control group were collected. The results showed there was a statistically significant difference (P<0.001) for morphometric and densitometric analysis of both detected MMPs in control and test groups. In conclusion, MMP-7 and MMP-9 were overexpressed in the synovial tissue of patients with ADDwoR.

An In vivo Immunohistochemical Study on MacroH2A.1 in Lung and Lymph-Node Tissues Exposed to an Asbestiform Fiber.

AIMS: The aim of this study was to investigate MacroH2A.1 immunoexpression in tissues of sheep exposed to FE. BACKGROUND: The correlation between asbestiform fibers, lung cancer, pleural mesothelioma, and other lung diseases is already well established as the pathophisiological pathophysiological respiratory mechanisms involved by inhalation of Fluoro-edenite (FE). The latter is represented by cell proliferation and inducing the release of growth factors, cytokines, and reactive oxygen and nitrite species, with DNA damage that causes chronic inflammation and carcinogenesis. MacroH2A.1, and histone variant, seems to play a role in sensing the metabolic state of the cell and linking it with chromatin. Physiologically, MacroH2A.1 is expressed at low levels in stem cells and it became upregulated during differentiation, preventing reprogramming of induced pluripotent stem cells and after nuclear transfer. In particular, MacroH2A.1 has been shown to explicate a potent antitumor mechanism in vivo as it results upregulated in senescent cells determining a permanent growth-arrest. OBJECTIVE: Evaluate the possible role of the histone variant in the organism in response to deep insight understanding the mechanisms of toxicity and the cellular response to FE. METHODS: Lung and lymph nodes of exposed sheep were selected. Samples were processed for histological and immunihistochemical immunohistochemical evaluations. Densitometric, morphometric, and statistical analysis analyses were conducted. RESULTS: Tissue sections of FE exposed sheep demonstrated overexpression of MacroH2A.1 vs unexposed samples. The data suggest an involvement of these this molecule in the cellular response triggered by FE directed exposure. CONCLUSION: In this contest, MacroH2A.1 overexpression supports its function as an epigenetic stabilizer that helps to establish and maintain differentiated states.

Immunohistochemical expression and localization of MMP-9, MMP-13, E-Cadherin and Ki-67 in road pavers' skin chronically exposed to bitumen products.

To investigate the matrix metalloproteinase (MMP)-9, (MMP)-13, E-Cadherin and Ki-67 expressions in road pavers' skin chronically exposed to bitumen products in order to contribute to a better understanding of the earlier tissue alteration. Skin punch biopsies from 16 daily exposed workers and a control group were studied by immunohistochemistry. Morphometric and densitometric analyses were also conducted. Morphological specimen evaluation of skin of road pavers showed epidermal thinning, flattening and loss of intercellular junction with a decreased expression of E-cadherin confined to the basal skin layer, together with MMP-9 and MMP-13 overexpressions in all epidermis layers, vascular structures and adnexa. No immunohistochemical alteration was reported for Ki-67 vs normal skin. Results from this study show that overexpression of MMP-9 and MMP-13 may represent an early response of the first human barrier to exposure to bitumen products. Regulation of MMPs could be one of the strategies to prevent primary skin disease.

Decomposing Human Blood: Canine Detection Odor Signature and Volatile Organic Compounds.

The admissibility of human "odor mortis" discrimination in courts depends on the lack of comprehension of volatile organic compounds (VOCs) during the human decay process and of the lack in standardized procedures in training cadaver dogs. Blood was collected from four young people who died from traffic accidents and analyzed using HS-SPME/GC-MS at different decompositional stages. Two dogs, professionally trained, were tested to exactly locate blood samples, for each time point of the experiment. We found a long list of VOCs which varied from fresh to decomposed blood samples, showing differences in specific compounds. Dog performance showed a positive predictive value between 98.96% and 100% for DOG A, and between 99.47% and 100% for DOG B. Our findings demonstrated that decomposing human blood is a good source of VOCs and a good target for canine training.

Abnormal Plasma Cell Disorders in Refinery Waste Workers.

A monoclonal gammopathy of undetermined significance (MGUS) may develop into a multiple myeloma or a correlated lymphoproliferative malignancy with a progress rate of 1% per year. The immune status, occupational-environmental risk factors, and hereditary factors may influence the risk of developing MGUS. We investigated the prevalence of MGUS in 77 refinery waste workers. They were all males, averagely aged 36, with a mean working history of 18.5 years and working in the dump for about 4.2 years. After analyzing the results of standard serum electrophoresis migrations, 16% of cases (n = 12) showed levels beyond the normal ranges. In all 12 samples we observed an increase of gamma component: 67%, IgG; 17%, IgM; 8%, IgA; 8%, oligoclonal. Workers were exposed to hazardous refinery waste. After the biological monitoring of urine samples for metals and t,t-muconic acid, no extra-range values were observed. The multivariate analysis shows, however, that cigarette smoking and residence near industrial sites are significantly (p < 0.001) associated with a high risk of MGUS development; while no association was found with occupational exposure. Additional attention might be paid in particular to these conditions in epidemiological studies and further larger, prospective, population-based researches appear warranted to evaluate the strength of any positive association.