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1.
J Clin Microbiol ; 54(3): 576-84, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26677254

ABSTRACT

Despite the current reliance on blood cultures (BCs), the diagnosis of bloodstream infections (BSIs) can be sped up using new technologies performed directly on positive BC bottles. Two methods (the MALDI BioTyper system and FilmArray blood culture identification [BCID] panel) are potentially applicable. In this study, we performed a large-scale clinical evaluation (1,585 microorganisms from 1,394 BSI episodes) on the combined use of the MALDI BioTyper and FilmArray BCID panel compared to a reference (culture-based) method. As a result, the causative organisms of 97.7% (1,362/1,394) of the BSIs were correctly identified by our MALDI BioTyper and FilmArray BCID-based algorithm. Specifically, 65 (5.3%) out of 1,223 monomicrobial BCs that provided incorrect or invalid identifications with the MALDI BioTyper were accurately detected by the FilmArray BCID panel; additionally, 153 (89.5%) out of 171 polymicrobial BCs achieved complete identification with the FilmArray BCID panel. Conversely, full use of the MALDI BioTyper would have resulted in the identification of only 1 causative organism in 97/171 (56.7%) of the polymicrobial cultures. By applying our diagnostic algorithm, the median time to identification was shortened (19.5 h versus 41.7 h with the reference method; P < 0.001), and the minimized use of the FilmArray BCID panel led to a significant cost savings. Twenty-six out of 31 microorganisms that could not be identified were species/genera not designed to be detected with the FilmArray BCID panel, indicating that subculture was not dispensable for a few of our BSI episodes. In summary, the fast and effective testing of BC bottles is realistically adoptable in the clinical microbiology laboratory workflow, although the usefulness of this testing for the management of BSIs remains to be established.


Subject(s)
Blood/microbiology , Microbiological Techniques/methods , Molecular Diagnostic Techniques/methods , Polymerase Chain Reaction/methods , Sepsis/diagnosis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Algorithms , Humans , Microbiological Techniques/economics , Molecular Diagnostic Techniques/economics , Prospective Studies , Sensitivity and Specificity , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/economics , Time Factors
2.
Oncogene ; 34(40): 5175-86, 2015 Oct 01.
Article in English | MEDLINE | ID: mdl-25619830

ABSTRACT

There is increasing evidence that mast cells (MCs) and their mediators are involved in the remodeling of the tumor microenvironment and promote tumor growth, angiogenesis and metastasis. We have found that an increased density of MCs in thyroid cancer (TC) correlates with enhanced invasiveness. However, the MC-derived factors responsible for this activity and the mechanisms by which they enhance TC invasiveness remain unidentified. Here, we report that MCs, when activated by TC cells, produce soluble factors that induce epithelial-to-mesenchymal transition (EMT) and stemness features of TC cells. We identified CXCL8/interleukin (IL)-8 as the main mediator contained in activated MC conditioned media (CM) capable of inducing both EMT and stemness of TC cells. Mechanistically, MC CM or exogenous IL-8 stimulated Akt phosphorylation and Slug expression in TC cells. The inhibition of the Akt pathway or depletion of the Slug transcription factor by RNA interference, reverted EMT and stemness responses. TC cells stably transfected with exogenous IL-8 underwent EMT, displayed increased stemness and enhanced tumorigenicity with respect to control cells. The analysis of TC surgical specimens by immunohistochemical analysis demonstrated a positive correlation between MC density (Tryptase(+) cells) and stemness features (OCT4 staining). Taken together, our data identify an MC-dependent IL-8-Akt-Slug pathway that sustains EMT/stemness of TC cells. The blockade of this circuit might be exploited for the therapy of advanced TC.


Subject(s)
Epithelial-Mesenchymal Transition/physiology , Mast Cells/metabolism , Signal Transduction/physiology , Thyroid Neoplasms/pathology , Animals , Cell Line , Female , Heterografts , Humans , Immunoblotting , Immunohistochemistry , Interleukin-8/metabolism , Mice , Mice, Nude , Neoplastic Stem Cells/cytology , Proto-Oncogene Proteins c-akt/metabolism , Real-Time Polymerase Chain Reaction , Snail Family Transcription Factors , Tissue Array Analysis , Transcription Factors/metabolism , Transfection
3.
Oncogene ; 34(29): 3826-38, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25263443

ABSTRACT

N-formyl peptide receptors (FPR1, FPR2 and FPR3) are involved in innate immunity, inflammation and cancer. FPR expression, initially described in immune cells, was later observed in non-hematopoietic cell populations and tissues. Several studies suggested a role for FPRs in the progression of various tumor histotypes, including gastric cancer (GC), for which a positive association with a specific FPR1 polymorphism has recently been described. We previously showed that FPRs are expressed on gastric epithelium and are required for wound repair and restitution of barrier integrity. Here we assess the role of FPRs in GC. We characterized the functions of FPRs in GC epithelial cells (MKN28, AGS and MKN45) cultured in vitro by assessing migration, proliferation, resistance to apoptosis and activation of the epithelial-to-mesenchymal transition. Activation of each FPR induced the epithelial-to-mesenchymal transition, proliferation, resistance to apoptosis and migration of GC cells in culture. Blocking compounds or RNA interference of each FPR reverted these effects. We also defined the in vivo tumorigenic potential of GC epithelial cells silenced for FPRs by xenograft experiments in immunocompromised mice. Interestingly, FPR1 silencing in GC cells (shFPR1) significantly enhanced xenograft growth with respect to shCTR, shFPR2 and shFPR3 xenografts, because of augmented vessel density and cell proliferation. Accordingly, HIF-1α and VEGF mRNA levels were higher in shFPR1 xenografts than in controls. Moreover, the in vitro production of proangiogenic factors in response to FPR2/3 agonists (WKYMVm, LL-37, uPA, uPAR84-95, AnxA1) or to other proinflammatory mediators (IL-1α) was higher in shFPR1 GC cells than in shCTR, shFPR2 and shFPR3 cells, suggesting that FPR1 functions as an inhibitor of CG angiogenesis. Thus, we propose that FPR1 stimulation may represent a novel therapeutic approach to counteract tumor angiogenesis.


Subject(s)
Neovascularization, Pathologic/genetics , Receptors, Formyl Peptide/genetics , Stomach Neoplasms/genetics , Tumor Suppressor Proteins/genetics , Animals , Apoptosis/genetics , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/genetics , Cells, Cultured , Epithelial-Mesenchymal Transition/genetics , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Immunohistochemistry , Mice, Inbred C57BL , Mice, Nude , Mice, SCID , N-Formylmethionine Leucyl-Phenylalanine/pharmacology , Neovascularization, Pathologic/metabolism , Oligopeptides/pharmacology , RNA Interference , Receptors, Formyl Peptide/agonists , Receptors, Formyl Peptide/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Stomach Neoplasms/blood supply , Stomach Neoplasms/metabolism , Tumor Suppressor Proteins/metabolism , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolism , Xenograft Model Antitumor Assays/methods
4.
Med Lav ; 102(2): 201-7, 2011.
Article in Italian | MEDLINE | ID: mdl-21485057

ABSTRACT

BACKGROUND: A growing number of reports pinpoint the high prevalence of mood disorders in OSAS patients. The aim of the study was to verify the presence of depressive mood disorders and their relationship with OSAS in a population of public transport drivers. METHODS: 164 city bus drivers underwent an anthropometric and biochemical assessment, administration of ESS and Zung Scale questionnaires and cardio-respiratory polysomnography (PSG). The data were compared with a matched control group of 171 subjects. RESULTS: The two groups of subjects differed as regards BMI (p < 0.001), neck circumference (p < 0.001), fasting plasma glucose (p < 0.001), basal insulin (p < 0.001) and HOMA index (p < 0.001), degree of daytime sleepiness (p < 0.001) and Zung scale score (p < 0.001). PSG revealed significant differences in AHI (p < 0001), ODI (p < 0001), in the absolute and mean values of the nadir of the ODI (for both p < 0001), in total sleep time with O2 saturation level values < 90% (p < 0.001) and < 80% (p < 0.001). Pearson's correlation analysis showed a linear relationship between AHI and Zung scale (r = 0.75, p = 0.000) and between ODI and ESS (r = 0.59, p = 0.000). CONCLUSIONS: The role of sleep-related breathing disorders in mood modulation is well known from the literature. Our results highlight the relationship between OSAS and mood lowering in urban bus drivers, suggesting the need for a multidisciplinary approach to assess the health of this occupational group, including assessment of any sleep disorders, with particular reference to those of a respiratory nature.


Subject(s)
Mood Disorders/diagnosis , Mood Disorders/epidemiology , Sleep Apnea, Obstructive/diagnosis , Sleep Apnea, Obstructive/epidemiology , Transportation , Algorithms , Case-Control Studies , Cities , Depressive Disorder/diagnosis , Depressive Disorder/epidemiology , Female , Humans , Italy/epidemiology , Male , Middle Aged , Mood Disorders/etiology , Motor Vehicles , Polysomnography , Prevalence , Risk Assessment , Risk Factors , Sleep Apnea, Obstructive/complications , Surveys and Questionnaires , Workforce
5.
Oncogene ; 29(47): 6203-15, 2010 Nov 25.
Article in English | MEDLINE | ID: mdl-20729915

ABSTRACT

In different human carcinoma types, mast cell infiltrate increases with respect to normal tissue and mast cell density correlates with a bad prognosis. To assess the role of mast cells in human thyroid cancer, we compared the density of tryptase-positive mast cells in 96 papillary thyroid carcinomas (PTCs) versus normal thyroid tissue from 14 healthy individuals. Mast cell density was higher in 95% of PTCs (n=91) than in control tissue. Mast cell infiltrate correlated with extrathyroidal extension (P=0.0005) of PTCs. We show that thyroid cancer cell-line-derived soluble factors induce mast cell activation and chemoattraction in vitro. Different mast cell lines (HMC-1 and LAD2) and primary human lung mast cells induced thyroid cancer cell invasive ability, survival and DNA synthesis in vitro. The latter effect was mainly mediated by three mast-cell-derived mediators: histamine, and chemokines CXCL1/GROα and CXCL10/IP10. We show that xenografts of thyroid carcinoma cells (8505-C) could recruit mast cells injected into the tail vein of mice. Co-injection of human mast cells accelerated the growth of thyroid cancer cell (8505-C) xenografts in athymic mice. This effect was mediated by increased tumor vascularization and proliferation, and was reverted by treating mice with sodium cromoglycate (Cromolyn), a specific mast cell inhibitor. In conclusion, our study data suggest that mast cells are recruited into thyroid carcinomas and promote proliferation, survival and invasive ability of cancer cells, thereby contributing to thyroid carcinoma growth and invasiveness.


Subject(s)
Mast Cells/physiology , Thyroid Neoplasms/pathology , Animals , Cell Count , Cell Line, Tumor , Cell Proliferation , Cell Survival , Cell Transformation, Neoplastic , Humans , Male , Mast Cells/immunology , Mice , Mice, Inbred BALB C , Neoplasm Invasiveness , Neoplasm Transplantation , Prognosis , Thyroid Neoplasms/blood supply , Thyroid Neoplasms/metabolism , Vascular Endothelial Growth Factor A/metabolism
6.
G Ital Med Lav Ergon ; 29(3 Suppl): 703-5, 2007.
Article in Italian | MEDLINE | ID: mdl-18409914

ABSTRACT

MMPI-2 test is widely used in psychodiagnostic evaluation as well as in the evaluation of psychic pathologies related to psychosocial adversative events in working activities. A more efficacious use of MMPI-2 test in the working context can be achieved by the individuation of indexes able to facilitate the evaluation of mobbing syndrome. This work is based on the analysis of 150 cases (39.7% women and 60.7% men, 30 to 60 years of age), evaluated through an accurate examination of working history and a series of clinic conversations, followed by psychodiagnostic evaluation. The average of T-scores on the clinical scale, the content scale, the PK addition scale and the validation scale were calculated from tests. Pathologic high T-scores on the scales Hs, D. Hy e Pa were found in subjects having positive mobbing anamnesis. These results strongly indicate the presence of clinical specificities in workers exposed to working harassments, and that these specificities can be efficaciously evidenced by the MMPI-2 test.


Subject(s)
MMPI , Occupational Diseases/diagnosis , Social Behavior , Stress Disorders, Post-Traumatic/diagnosis , Adult , Female , Humans , Male , Middle Aged
7.
G Ital Med Lav Ergon ; 29(3 Suppl): 836-8, 2007.
Article in Italian | MEDLINE | ID: mdl-18409989

ABSTRACT

Obstructive Sleep Apnea Syndrome (OSAS) is a very common disease in work age. Aim of study is to assess the impact of OSAS in a workers population. 138 workers (M 117, F 21), age 35-65 (mean 52.66 +/- 3.042) consecutively referred to Respiratory Hospital Monaldi and to Occupational Health Medicine Department of Second University of Naples performed an anthropometric evaluation of BMI, neck and an overnight polisomnography with Embletta X10 (Flaga Medical Devices; Reykjavik, Iceland). Workers' population was divided into three groups according to the impact of daytime sleepiness on work efficiency. Occupational Health Medicine needs to evaluate the high prevalence of obesity and metabolic syndrome (OSAS, diabetes, insulin-resistance) in work age population.


Subject(s)
Occupational Health , Sleep Apnea, Obstructive , Work , Adult , Aged , Female , Humans , Male , Middle Aged , Sleep Apnea, Obstructive/physiopathology
8.
G Ital Med Lav Ergon ; 28(2): 216-7, 2006.
Article in Italian | MEDLINE | ID: mdl-16805474

ABSTRACT

According to Italian laws (legge 125/01, art. 15, comma 1) about safety on workplaces, it's forbidden alcohol drinking and taking for health workers (art. 8, comma 6, legge 5/06/2003 number 131) (e.g. anaesthesiology, surgery, radiology, nursing etc.). National alcoholism risk prevention program to assess number for year of accidents in health workplaces, is actually in progress leaded by Health Minister and Regional administration (e.g. Tuscany). Particularly, prevention program acts consist in comprehensive informations for health workers and their co- workers, about prevention and identification of alcoholism- related risks. To assess the size of alcohol problems in health workplaces, Occupational Health Medicine Institute of Second University of Naples is going to enrol 500 subjects (200 nursing students, 200 Specialist Registrars of different areas, 100 Consultants). Actually our population consists in 160 Specialist Registrars of different medical subjects (surgery, clinical and laboratory). To verify the importance of alcoholism risk perception, a not validated questionnaire was administrated. This original assessing instrument consists in 23 items with closed answers about demographic information, university, career, lifestyle, knowledge about rules taking alcoholic drinks. Results show a dangerous lack of information about alcohol health effects, even in Medical Specialist Registrars.


Subject(s)
Alcoholism/prevention & control , Health Personnel , Humans , Population Surveillance , Risk Factors , Surveys and Questionnaires
9.
G Ital Med Lav Ergon ; 27(2): 184-98, 2005.
Article in Italian | MEDLINE | ID: mdl-16124529

ABSTRACT

To have the right value of the possible causes responsible of muscles-skeleton disorders, and to have a right therapeutic measures, the Authors have get ready an holistic method, that value not only the damage's point, but also research in the others body-districts, named Peripheral Receptors, the causes responsible of pathologic manifestation. The methods is used on 61 VDU and it consists in: clinical rachis exam (like EPM methods), postural, odontological, oculistic, podiatric and psychologic visits. The study have permitted to underlines muscles-skeletons disorders precociously, not only in symptomatic subjects, but also in those asymptomatic, so it is an important prevention's instrument, diagnostic framing and medico-legal of studied pathologies.


Subject(s)
Musculoskeletal Diseases , Occupational Diseases , Adult , Age Factors , Electrocardiography , Electromyography , Ergonomics , Eye Diseases/diagnosis , Eye Diseases/prevention & control , Female , Follow-Up Studies , Holistic Health , Humans , Male , Mental Disorders/diagnosis , Mental Disorders/prevention & control , Middle Aged , Musculoskeletal Diseases/diagnosis , Musculoskeletal Diseases/prevention & control , Occupational Diseases/diagnosis , Occupational Diseases/prevention & control , Occupations , Podiatry , Posture , Research , Sex Factors , Spine/physiology , Time Factors , Tooth Diseases/diagnosis , Tooth Diseases/prevention & control
10.
G Ital Med Lav Ergon ; 27(2): 199-201, 2005.
Article in Italian | MEDLINE | ID: mdl-16124530

ABSTRACT

The whole of trading enterprises with many average/big saling-centres forms what is today commonly known as Large Organized Distribution (LOD). The main risks regarding the people working in the LOD are: MM, repetitive motion of upper limbs, fixed postures, unfavourable microclimatic conditions and, moreover, the probability of labour accidents. In order to analyse the risks due to MM and false postures, we have used the ergonomic software "Classic Jack" distributed by EAI-UGS, which has been very helpful to find out the most dangerous labour operations (e.g. charging and discharging of goods, fragmentation and reassembling of manufactures, goods-shelving, branding and labelling). We have, then, suggested a programme of health surveillance that includes a medical examination, eventual x-ray exams, specialized examination and a posturologic visit. This posturologic visit has got an olistic diagnostics approach, whose research after the causes that could be responsible for the checked diseases concerns not only the damaged area, but also other parts of the body (ocular system, auditive system, podalic system, masticatory apparatus).


Subject(s)
Commerce , Occupational Health , Accidents, Occupational , Humans , Microclimate , Posture , Research , Risk Factors , Spirometry
11.
G Ital Med Lav Ergon ; 27(1): 124-8, 2005.
Article in Italian | MEDLINE | ID: mdl-15915686

ABSTRACT

In this work the Authors propose a methodology based on the use of an ergonomic software in alternative to the traditional methods to evaluate muscular-skeletal diseases caused by incongruous postures or conditions of mechanical overload. This methodology allows to simulate, in a virtual environment, both a workplace and a digital human model whose behaviours are similar, from a kinematical and a dynamical point of view, to that ones of a real person. Through the simulation in a virtual environment of an operation of Manual Material Handling (MMH) in a pharmaceutics industry, the Authors have evaluated, in real time, the strengths and the reaction-moments in the axial, sagittal and lateral plane on the L4 and L5 lumbar vertebras and on the shoulder of the workers. In the work the single movements carried out by the operator are analysed using manikins of different percentiles. The results are compared with the ones coming from the use of the traditional methods to evaluate muscular skeletal disease.


Subject(s)
Lifting , Models, Theoretical , Musculoskeletal Diseases/etiology , Occupational Diseases/etiology , Humans , Risk Factors
12.
Int Arch Occup Environ Health ; 78(4): 337-41, 2005 May.
Article in English | MEDLINE | ID: mdl-15750820

ABSTRACT

Recent studies suggest that professional exposure to Extremely Low Frequency-Electro Magnetic Field (ELF-EMF) can increase the risk of sudden cardiac death. Aim of our work was to find predictive parameters of arrhythmic risk in a population of 28 railways drivers exposed to ELF-EMF. Our findings were that the exposure did not reduce HRV and did not increase the risk of arrhythmias.


Subject(s)
Arrhythmias, Cardiac/etiology , Electromagnetic Fields/adverse effects , Railroads , Humans , Italy , Occupational Exposure , Risk Assessment , Risk Factors
13.
G Ital Med Lav Ergon ; 26(4): 401-15, 2004.
Article in Italian | MEDLINE | ID: mdl-15584451

ABSTRACT

This paper examines the problem of assessing thermal conditions in moderate working environments. Following a brief reminder of the fundamental principles of thermal comfort (in terms of balance equation, measurement techniques and indices of global and local thermal discomfort), the question of subjective assessment is discussed. Finally, a method of evaluation of thermal comfort is proposed.


Subject(s)
Occupational Health , Temperature , Air Conditioning , Body Temperature , Body Temperature Regulation , Heating , Humans , Models, Theoretical , Surveys and Questionnaires , Thermosensing
14.
G Ital Med Lav Ergon ; 26(4): 416-28, 2004.
Article in Italian | MEDLINE | ID: mdl-15584452

ABSTRACT

This paper presents indications for investigations and health surveillance in indoor environments. The study of the indoor air quality consists of the following phases: acquisition of the necessary information about the indoor environment; sampling strategy and techniques; qualitative and quantitative analysis of contaminants such as particulate, CO2 and CO, NOx, volatile organic compounds, biological agents. The proposed health surveillance is articulated on four lines: periodical health surveillance, when already performed for other risks (e.g. VDT); specific clinical examinations in occasion of particular events; use of a questionnaire for the evaluation of comfort of the workers; health promotion. A team approach, with cooperation between technical and medical experts, is recommended both for periodical risk assessment and when it is necessary to solve specific indoor problems.


Subject(s)
Air Pollution, Indoor/prevention & control , Occupational Health , Air Pollutants/analysis , Air Pollutants, Occupational/analysis , Air Pollution, Indoor/analysis , Humans , Mineral Fibers/analysis , Risk Assessment , Surveys and Questionnaires , Tobacco Smoke Pollution
15.
Bull Cancer ; 80(1): 62-8; discussion 68-9, 1993 Jan.
Article in English | MEDLINE | ID: mdl-8204920

ABSTRACT

The effects various drugs exert on antioxidant enzyme and glyoxalase activity in rat livers were studied. All drugs tested provoked a marked reduction in glutathione peroxidase and a small drop in both glyoxalase I and II activity. It is hypothesized that the substances tested support tumour development by neutralizing organic peroxides, thereby favouring the oxidation of carcinogens and, as a consequence, the formation of metabolites that trigger neoplastic transformation. The reduction in glyoxalase activity is probably attributable to the enhanced cell proliferation induced by the treatment.


Subject(s)
Lactoylglutathione Lyase/metabolism , Liver/enzymology , Neoplasms, Experimental/chemically induced , Thiolester Hydrolases/metabolism , Animals , DDT/pharmacology , Depression, Chemical , Estradiol/pharmacology , Female , Neoplasms, Experimental/enzymology , Oxidoreductases/antagonists & inhibitors , Phenobarbital/pharmacology , Rats , Rats, Wistar , Tetradecanoylphorbol Acetate/pharmacology
16.
Int J Cancer ; 43(6): 1145-8, 1989 Jun 15.
Article in English | MEDLINE | ID: mdl-2732003

ABSTRACT

Variations in catalase, glutathione peroxidase (GP) and adenylate cyclase (AC) activity in murine erythroleukemic (MEL) cells were studied during multiplication and dimethylsulfoxide (DMSO)-induced differentiation. The results demonstrated that, although DMSO favors the incorporation of 3H-thymidine into DNA of treated cells, it slows down cell multiplication. Increased incorporation was also observed in superoxide dismutase (SOD)-treated cells. DMSO also determined an early and significant drop in AC activity and a late fall in catalase activity, whereas there was no significant variation in GP activity in parallel with the decreased cell multiplication that accompanied cell differentiation. We hypothesize that DMSO and SOD favor 3H-thymidine incorporation by neutralizing the reactive forms of oxygen and that the reduction in catalase and AC activity is closely related to the mitotic activity of MEL cells.


Subject(s)
Dimethyl Sulfoxide/pharmacology , Leukemia, Erythroblastic, Acute/enzymology , Adenylyl Cyclases/metabolism , Animals , Catalase/metabolism , Cell Count/drug effects , Cell Division/drug effects , Cell Line , Friend murine leukemia virus , Glutathione Peroxidase/metabolism , Mice , Superoxide Dismutase/pharmacology , Thymidine/metabolism , Tritium , Tumor Cells, Cultured
17.
Cell Mol Biol ; 35(5): 487-94, 1989.
Article in English | MEDLINE | ID: mdl-2611835

ABSTRACT

The effects of catalase treatment were studied in two in vitro passaged ascites tumour lines (ATP C+ and EAT) and in three in vitro established human myeloid leukemia cell lines (HL-60; KG-1; KG-1a) characterized by the arrest of cells at different stages of maturation. The results demonstrate that catalase treatment favoured proliferation in the in vitro passaged ascites tumour cells, but not in the in vitro established leukemia lines. Enzyme assays on five in vitro cell lines revealed that catalase was only present in HL-60. Although glutathione peroxidase activity was initially found in all five cell lines, it disappeared from two ascites tumour cells when they were transferred in culture. It is hypothesized that catalase treatment favours ascites tumour cell proliferation because it replaces glutathione peroxidase in eliminating H2O2.


Subject(s)
Catalase/pharmacology , Cell Division/physiology , Glutathione Peroxidase/metabolism , Tumor Cells, Cultured/cytology , Catalase/metabolism , Cell Differentiation , Humans , Thymidine , Tritium , Tumor Cells, Cultured/enzymology
18.
Bull Cancer ; 76(1): 43-50, 1989.
Article in English | MEDLINE | ID: mdl-2713514

ABSTRACT

Chick embryo hepatocytes were cultured in the presence of benzo(a)pyrene in order to study the effects of this carcinogen on catalase, glutathione peroxidase and superoxide dismutase activity. The results demonstrate that benzo(a)pyrene is incapable of modifying the activity of these enzymes, even though it is taken up by cultured cells to form benzo(a)pyrene-DNA adducts. The effect of culturing, however, caused a marked reduction in the activity of these enzymes. The significance of these activity variations in benzo(a)pyrene in vitro carcinogenesis is discussed.


Subject(s)
Benzo(a)pyrene/metabolism , Catalase/metabolism , Glutathione Peroxidase/metabolism , Liver/metabolism , Superoxide Dismutase/metabolism , Animals , Cells, Cultured , Chick Embryo , Liver/cytology , Liver/enzymology
19.
Int J Cancer ; 42(5): 803-6, 1988 Nov 15.
Article in English | MEDLINE | ID: mdl-3182110

ABSTRACT

An investigation was carried out to establish whether the reduction in catalase, glutathione peroxidase and superoxide dismutase activity, normally observed in liver tumours, is an early event and therefore of pathogenetic importance, or whether it is a late occurrence. Experiments performed on dimethylnitrosamine-treated hepatectomized and non-hepatectomized rats show that the decrease in activity of these enzymes is entirely due to hepatectomy, since the tumour-inducing doses of dimethylnitrosamine failed to provoke variations in the activity of these enzymes, in either normal or regenerating liver.


Subject(s)
Antioxidants/metabolism , Dimethylnitrosamine , Liver Neoplasms/chemically induced , Animals , Catalase/metabolism , DNA Damage , Glutathione Peroxidase/metabolism , Liver Neoplasms/enzymology , Liver Neoplasms/genetics , Male , Rats , Rats, Inbred Strains , Superoxide Dismutase/metabolism
20.
Cancer Lett ; 41(2): 235-42, 1988 Aug 15.
Article in English | MEDLINE | ID: mdl-3401847

ABSTRACT

The effects of treatment with reduced glutathione, cysteine and ascorbic acid on chick embryo fibroblasts and hepatocytes cultured in vitro in the presence of [G-3H]benzo[a]pyrene ([3H]BP) were studied in an attempt to evaluate the capacity of these antioxidants to interfere with the binding of the carcinogen to DNA in these two cell populations. The results revealed that in the absence of treatment with antioxidants, the carcinogen bound to the DNA of the hepatocytes less than it did to that of the fibroblasts, despite the fact that the two cell populations manifest more or less the same uptake of [G-3H]benzo[a]pyrene from the medium. Moreover the hepatocytes, unlike the fibroblasts, seemed to reap little advantage from the known capacity of the antioxidants to interfere with the binding of the carcinogen to DNA.


Subject(s)
Antioxidants/pharmacology , Benzo(a)pyrene/metabolism , DNA/metabolism , Liver/metabolism , Animals , Ascorbic Acid/pharmacology , Cells, Cultured , Chick Embryo , Cysteine/pharmacology , DNA/drug effects , Fibroblasts/metabolism , Glutathione/analogs & derivatives , Glutathione/pharmacology , Glutathione Disulfide , Kinetics , Tritium
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