45 research outputs found

    Abnormal mitotic spindle assembly and cytokinesis induced by D-Limonene in cultured mammalian cells

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    d-Limonene is found widely in citrus and many other plant species; it is a major constituent of many essential oils and is used as a solvent for commercial purposes. With the discovery of its chemotherapeutic properties against cancer, it is important to investigate the biological effects of the exposure to d-Limonene and elucidate its, as yet unknown, mechanism of action. We reported here that d-Limonene is toxic in V79 Chinese hamster cells in a dose-dependent manner. Moreover, to determine the cellular target of d-Limonene, we performed morphological observations and immunocytochemical analysis and we showed that this drug has a direct effect on dividing cells preventing assembly of mitotic spindle microtubules. This affects both chromosome segregation and cytokinesis, resulting in aneuploidy that in turn can lead to cell death or genomic instability

    Genomic instability induced by a-pinene in Chinese hamster cell line

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    Here, we report the effects of exposure of mammalian cells to a-pinene, a bicyclic monoterpene used in insecticides, solvents and perfums. Morphological analysis, performed in V79-Cl3 cells exposed for 1 h to increasing concentrations (25 up to 50 mM) of a-pinene, indicated a statistically significant increase in micronucleated and multinucleated cell frequencies; apoptotic cells were seen at 40 and 50 mM. This monoterpene caused genomic instability by interfering with mitotic process; in fact, 50% of cells (versus 19% of control cells) showed irregular mitosis with multipolar or incorrectly localised spindles. Cytogenetic analysis demonstrated high-frequency hypodiploid metaphases as well as endoreduplicated cells and chromosome breaks. Clastogenic damage was prevalent over aneuploidogenic damage as demonstred by the higher proportion of kinetochore-negative micronuclei. Alkaline comet confirmed that monoterpene exposure caused DNA lesions in a concentration-dependent manner. This damage probably arose by increased reactive oxygen species (ROS) production. In order to assess the generation of ROS, the cells were incubated with CM-H2DCFDA and then analysed by flow cytometry. Results demonstrated an increase in fluorescence intensity after a-pinene treatment indicating increased oxidative stress. On the whole, these findings strongly suggest that a-pinene is able to compromise genome stability preferentially through mitotic alterations and to damage DNA through ROS production

    Role and importance of polymorphisms with respect to DNA methylation for the expression of CYP2E1 enzyme

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    Different individuals possess slightly different genetic information and show genetically-determined differences in several enzyme activities due to genetic variability. Following an integrated approach,we studied the polymorphisms andmethylation of sites contained in the 5′ flanking region of themetabolizing enzyme CYP2E1 in correlation to its expression in both tumor and non-neoplastic liver cell lines, since to date little is known about the influence of these (epi)genetic elements in basal conditions and under induction by the specific inductor and a demethylating agent. In treated cells, reduced DNA methylation, assessed both at genomic and gene level, was not consistently associatedwith the increase of enzyme expression. Interestingly, the Rsa/Pst haplotype differentially influenced CYP2E1 enzyme expression. In addition, regarding the Variable Number of Tandem Repeats polymorphism, cells with A4/A4 genotype showed a greater expression inhibition (ranging from 20% to 30%) compared with others carrying the A2/A2 one, while those cells bringing A2/A3 genotype showed an increase of expression (of 25%, about). Finally, we demonstrated for the first time that the A2 and A3 CYP2E1 alleles play a more important role in the expression of the enzyme, compared with other (epi)genetic factors, since they are binding sites for trans-acting proteins

    Long-Lasting Genomic Instability Following Arsenite Exposure inMammalian Cells: The Role of Reactive Oxygen Species

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    Previously, we reported that the progeny of mammalian cells, which has been exposed to sodium arsenite for two cell cycles, exhibited chromosomal instability and concurrent DNA hypomethylation, when they were subsequently investigated after two months of subculturing (about 120 cell generations) in arsenite-free medium. In this work, we continued our investigations of the long-lasting arsenite-induced genomic instability by analyzing additional endpoints at several time points during the cell expanded growth. In addition to the progressive increase of aneuploid cells, we also noted micronucleated and multinucleated cells that continued to accumulate up to the 50th cell generation, as well as dicentric chromosomes and/or telomeric associations and other complex chromosome rearrangements that began to appear much later, at the 90th cell generation following arsenite exposure. The increasing genomic instability was further characterized by an increased frequency of spontaneous mutations. Furthermore, the long-lasting genomic instability was related to elevated levels of reactive oxygen species (ROS), which at the 50th cell generation appeared higher than in stable parental cells. To gain additional insight into the continuing genomic instability, we examined several individual clones isolated at different time points from the growing cell population. Chromosomally and morphologically unstable cell clones, the number of which increased with the expanded growth,were also present at early phases of growth without arsenite. All genomically unstable clones exhibited higher ROS levels than untreated cells suggesting that oxidative stress is an important factor for the progression of genomic instability induced by arsenite

    Cytochrome P450 2E1 variable number tandem repeat polymorphisms and health risks: A genotype-phenotype study in cancers associated with drinking and/or smoking

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    Cytochrome P450 2E1 (CYP2E1) is one of the main enzymes involved in the oxidation of ethanol and in the transformation of a number of potentially dangerous compounds. It has various polymorphic sites, one of which is a variable number tandem repeat (VNTR) polymorphism previously described in the 5'-flanking region. The aim of this study was to investigate the genotype-phenotype association between CYP2E1 VNTR polymorphisms and risky health habits in healthy subjects and to analyze the associations between these polymorphisms with drinking- and/or smoking-related cancers. We analyzed 166 healthy subjects by genotyping for the CYP2E1 VNTR polymorphism associated with drinking and/or smoking habits by the more sensitive restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) method, using the NlaIV restriction enzyme. Sixty cases of pancreatic adenocarcinoma (PA) and 66 with hepatocellular carcinoma (HCC), were also genotyped. Statistical analysis was carried out to investigate the genotype-phenotype associations and to compare certain genotypes and cancer. We found 7 genotypes both in the healthy subjects and patients. The A1/A1 genotype was observed to be mainly associated with non-drinkers and -smokers (87.5 and 75.0%, respectively); moreover it was never found in the PA or HCC patients. Conversely, a weak association between A2/A3 with smokers (45.8%) and A4/A4 with drinkers (53.9%) was detected. In addition, the A4/A4 genotype was found to be significantly associated to PA [odds ratio (OR)=3.25; 95% confidence interval (CI) 1.21-7.50]. Our data demonstrate that certain CYP2E1 VNTR genotypes are associated with drinking and/or smoking habits; consequently, they may contribute either to the decreased or increased risk of developing drinking- and/or smoking-related cancers. In particular, we hypothesize that the A1/A1 VNTR genotype may have a protective role against drinking- and/or smoking-related cancers, and that A4/A4 may be a high-risk genotype during the early stages of cancer

    Genotoxicity of citrus wastewater in prokaryotic and eukaryotic cells and efficiency of heterogeneous photocatalysis by TiO2

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    The presence of (±)a-pinene, (+)b-pinene, (+)3-carene, and R-(+)limonene terpenes in wastewater of a citrus transformation factory was detected and analyzed, in a previous study, by using Solid Phase Microextraction (SPME) followed by GC analyses. Purpose of that research was to compare the genotoxic responses of mixtures of terpenes with the genotoxicity of the individual compounds, and the biological effects of actual wastewater. Genotoxicity was evaluated in the Salmonella reversion assay (Ames test) and in V79 cells by Comet assay. Ames tests indicated that the four single terpenes did not induce an increase of revertants frequency. On the contrary, the mixtures of terpenes caused, in the presence of metabolic activation, a highly significant increase of the revertants in TA100 strain in comparison to the control. The Comet assay showed a significant increase in DNA damage in V79 cells treated for 1 h with single or mixed terpenes. Moreover, the actual wastewater was found highly genotoxic in bacterial and mammalian cells. Photocatalytic tests completely photodegraded the pollutants present in aqueous wastewater and the initial high genotoxicity of samples of wastewater collected during the photocatalytic run, was completely lose in 3 h of irradiation

    ALLELIC VARIANTS OF CYP2E1 GENE IN HEPATOCARCINOMA PATIENTS AND IN HEPATIC TUMOR CELL LINES

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    Background and Aims: Hepatic enzyme CYP2E1 is involved in the metabolism of a number of exogenous and endogenous substances (i.e. ethanol, drugs and chemical carcinogens). Being polymorphic, CYP2E1 gene can give different xeno-metabolic capabilities in a population and it is well known that inadequate or no enzymatic deactivation of xenobiotics could induce an increased susceptibility to disease and cancer. In particular, one of the 5 -flanking region polymorphisms, able to differentiate CYP2E1 gene transcriptional activity, is caused by the appearance/disappearance of RsaI and PstI restriction sites, which generates two different alleles, namely *C1(Rsa+/Pst−) and *C2(Rsa−/Pst+) respectively, reported to be in complete linkage disequilibrium. Methods: To confirm the existence of a correlation between some particular CYP2E1 genotypes/haplotypes and hepatocarcinoma, we determined CYP2E1 PstI/RsaI genotypes/haplotypes by RFLP-PCR in a cohort of central western Sicily hepatocarcinoma patients and in a population of healthy students from the same geographic area. Results: In hepatocarcinoma patients, modal genotype association was Rsa++/Pst−−, corresponding to CYP2E1 *C1/*C1 haplotype, whereas the Rsa+−/Pst−+ association, equivalent to CYP2E1 *C1/*C2 haplotype, resulted to have the lowest frequency both in patients and in controls. Moreover, both in patients and in controls, noncanonical genotype associations were frequent and arose from a no-linkage disequilibrium between the two polymorphic sites. Other authors reported this finding as a rare occurrence. Thus, from analysis of only one restriction site, Rsa++ genotype was approximately 1.5-fold more frequent in patients than in controls, and the non-canonical Rsa+− genotype was found relatively frequent in patients. Moreover, HuH7 and HA22T transformed hepatocarcinoma cell lines also showed the Rsa+− genotype. Conclusions: These results suggest that the presence in CYP2E1 genotype of at least one allele with an Rsa I restriction site is correlated with hepatocarcinoma. As this site is known a consensus sequence for some specific CYP gene transcription factors, like HNF-1, it may be supposed that a single nucleotide polymorphism can alter the possibility of HNF-1 to bind CYP2E1 promoter. This could determine a marked change in the transcriptional activity of the gene, incompetence in xenobiotic metabolism or in toxic substance deactivation and an increased susceptibility to neoplastic diseases, such as hepatocarcinoma

    A worldwide survey on incidence, management and prognosis of oesophageal fistula formation following atrial fibrillation catheter ablation: The POTTER-AF study.

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    AIMS Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management and outcome are sparse. METHODS AND RESULTS This international multicenter registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553,729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed at 214 centers in 35 countries. In 78 centers 138 patients (0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (p<0.0001)) were diagnosed with an oesophageal fistula. Periprocedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0-60) days and 21 (15, 29.5; range: 2-63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0-42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8%, and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) (odds ratio 7.463 (2.414, 23.072) p<0.001). CONCLUSIONS Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high

    Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both

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    Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81&nbsp;years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16-2.61) and patients with dementia (HR 1.75, 95% CI 1.06-2.90) had a higher risk of death at one year. The Kaplan-Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
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