Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 47
Filter
1.
Burns ; 49(7): 1541-1556, 2023 11.
Article in English | MEDLINE | ID: mdl-36914442

ABSTRACT

PURPOSE: To clarify and elaborate on the choices that were made in the development of the Patient Scale of the Patient and Observer Scar Assessment Scale 3.0 (POSAS 3.0), based upon the rich information obtained from patients during focus groups and pilot tests. METHODS: The discussions described in this paper are a reflection of the focus group study and pilot tests that were conducted in order to develop the Patient Scale of the POSAS3.0. The focus groups took place in the Netherlands and Australia and included 45 participants. Pilot tests were performed with 15 participants in Australia, the Netherlands, and the United Kingdom. RESULTS: We discussed the selection, wording and merging of 17 included items. Additionally, the reason for exclusion of 23 characteristics are given. CONCLUSION: Based upon the unique and rich material of patient input obtained, two versions of the Patient Scale of the POSAS3.0 were developed: the Generic version, and the Linear scar version. The discussions and decisions taken during the development are informative for a good understanding of the POSAS 3.0 and are indispensable as a background for future translations and cross-cultural adaptations.


Subject(s)
Burns , Cicatrix , Humans , Cicatrix/pathology , Burns/complications , Netherlands , Patients , Australia
2.
Qual Life Res ; 32(2): 583-592, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36355319

ABSTRACT

PURPOSE: The Patient and Observer Scar Assessment Scale (POSAS) is widely used for measurements of scar quality. This encompasses visual, tactile and sensory characteristics of the scar. The Patient Scale of previous POSAS versions was lacking input from patients. Therefore, the aim of this study was to develop the POSAS3.0, Patient Scale with involvement of adults patients with all scar types, complying with the highest clinimetric standards. METHODS: From February 2018 to April 2019, a series of six focus group interviews were performed in the Netherlands and Australia to identify scar quality characteristics that adults with scars consider to be important. All focus groups were transcribed, anonymized and analysed using a thematic analysis. Relevant characteristics were formulated into items, resulting in a Dutch and English version of the Patient Scale. These drafts were pilot tested in Australia, the Netherlands and the United Kingdom, and refined accordingly. RESULTS: A total of 21 relevant scar quality characteristics were identified during the focus groups. Two distinct versions of the POSAS3.0, Patient Scale were developed. The Generic version contains 16 items and can be used for all scar types, except linear scars. The Linear Scar version of the Patient Scale contains the same 16 items, with an extra item referring to the widening of scar margins. All included items are rated on a verbal rating scale with five response options. CONCLUSION: Two versions of the POSAS3.0 Patient Scale were developed. Further field tests are being performed to establish the measurement properties and scoring algorithm of the scales.


Subject(s)
Cicatrix , Quality of Life , Adult , Humans , Quality of Life/psychology , Reference Standards , Qualitative Research , Focus Groups
3.
Nanoscale Adv ; 3(21): 6213-6222, 2021 Oct 27.
Article in English | MEDLINE | ID: mdl-36133951

ABSTRACT

In nanomedicine, treatments based on physical mechanisms are more and more investigated and are promising alternatives for challenging tumor therapy. One of these approaches, called magneto-mechanical treatment, consists in triggering cell death via the vibration of anisotropic magnetic particles, under a low frequency magnetic field. In this work, we introduce a new type of easily accessible magnetic microparticles (MMPs) and study the influence of their surface functionalization on their ability to induce such an effect, and its mechanism. We prepared anisotropic magnetite microparticles by liquid-phase ball milling of a magnetite powder. These particles are completely different from the often-used SPIONs: they are micron-size, ferromagnetic, with a closed-flux magnetic structure reminiscent of that of vortex particles. The magnetic particles were covered with a silica shell, and grafted with PEGylated ligands with various physicochemical properties. We investigated both bare and coated particles' in vitro cytotoxicity, and compared their efficiency to induce U87-MG human glioblastoma cell apoptosis under a low frequency rotating magnetic field (RMF). Our results indicated that (1) the magneto-mechanical treatment with bare MMPs induces a rapid decrease in cell viability whereas the effect is slower with PEGylated particles; (2) the number of apoptotic cells after magneto-mechanical treatment is higher with PEGylated particles; (3) a lower frequency of RMF (down to 2 Hz) favors the apoptosis. These results highlight a difference in the cell death mechanism according to the properties of particles used - the rapid cell death observed with the bare MMPs indicates a death pathway via necrosis, while PEGylated particles seem to favor apoptosis.

5.
Sci Total Environ ; 630: 609-617, 2018 Jul 15.
Article in English | MEDLINE | ID: mdl-29494970

ABSTRACT

Nanoparticles (NPs) and in particular TiO2-NPs are increasingly included in commercial goods leading to their accumulation in sewage sludge which is spread on agricultural soils as fertilizers in many countries. Crop plants are thus a very likely point of entry for NPs in the food chain up to humans. So far, soil influence on NP fate has been under-investigated. In this article, we studied the partitioning of TiO2-NPs between soil and soil leachate, their uptake and biotransformation in wheat seedlings and their impact on plant development after exposure on 4 different types of soil with different characteristics: soil texture (from sandy to clayey), soil pH, cationic exchange capacity, organic matter content. Results suggest that a NP contamination occurring on agricultural soils will mainly lead to NP accumulation in soil (increase of Ti concentration up to 302% in sand) but to low to negligible transfer to soil leachate and plant shoot. In our experimental conditions, no sign of acute phytotoxicity has been detected (growth, biomass, chlorophyll content). Clay content above 6% together with organic matter content above 1.5% lead to translocation factor from soil to plant leaves below 2.5% (i.e. below 13mgTi·kg-1 dry leaves). Taken together, our results suggest low risk of crop contamination in an agro-ecosystem.


Subject(s)
Agriculture , Ecosystem , Environmental Monitoring , Nanoparticles/analysis , Soil Pollutants/analysis , Titanium/analysis , Soil/chemistry
6.
Burns ; 43(7): 1516-1523, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28536040

ABSTRACT

BACKGROUND: Objective measurement tools may be of great value to provide early and reliable burn wound assessment. Thermal imaging is an easy, accessible and objective technique, which measures skin temperature as an indicator of tissue perfusion. These thermal images might be helpful in the assessment of burn wounds. However, before implementation of a novel measurement tool into clinical practice is considered, it is appropriate to test its clinimetric properties (i.e. reliability and validity). The objective of this study was to assess the reliability and validity of the recently introduced FLIR ONE thermal imager. MATERIAL AND METHODS: Two observers obtained thermal images of burn wounds in adult patients at day 1-3, 4-7 and 8-10 after burn. Subsequently, temperature differences between the burn wound and healthy skin (ΔT) were calculated on an iPad mini containing the FLIR Tools app. To assess reliability, ΔT values of both observers were compared by calculating the intraclass correlation coefficient (ICC) and measurement error parameters. To assess validity, the ΔT values of the first observer were compared to the registered healing time of the burn wounds, which was specified into three categories: (I) ≤14 days, (II) 15-21 days and (III) >21 days. The ability of the FLIR ONE to discriminate between healing ≤21 days and >21 days was evaluated by means of a receiver operating characteristic curve and an optimal ΔT cut-off value. RESULTS: Reliability: ICCs were 0.99 for each time point, indicating excellent reliability up to 10 days after burn. The standard error of measurement varied between 0.17-0.22°C. VALIDITY: the area under the curve was calculated at 0.69 (95% CI 0.54-0.84). A cut-off value of -1.15°C shows a moderate discrimination between burn wound healing ≤21 days and >21 days (46% sensitivity; 82% specificity). CONCLUSION: Our results show that the FLIR ONE thermal imager is highly reliable, but the moderate validity calls for additional research. However, the FLIR ONE is pre-eminently feasible, allowing easy and fast measurements in clinical burn practice.


Subject(s)
Burns/diagnostic imaging , Skin/diagnostic imaging , Thermography/instrumentation , Adolescent , Adult , Aged , Aged, 80 and over , Burns/diagnosis , Computers, Handheld , Female , Humans , Male , Middle Aged , Prognosis , Reproducibility of Results , Temperature , Time Factors , Wound Healing , Young Adult
7.
Mutagenesis ; 32(1): 161-172, 2017 01.
Article in English | MEDLINE | ID: mdl-27803034

ABSTRACT

For some decades production of titanium dioxide nanoparticle (TiO2-NP) has been increasing at a considerable rate; concerns as to the toxicity of these particles upon inhalation have been raised. Indeed, TiO2-NPs have been shown to induce significant genotoxicity and to adversely affect both major DNA repair mechanisms: base excision repair (BER) and nucleotide excision repair (NER). The aims of the present study were to (i) compare the genotoxicity of TiO2-NPs and their impact on DNA repair processes on A549 alveolar carcinoma and BEAS-2B normal bronchial lung cell lines and (ii) delve deeper into the mechanisms leading to these effects. To achieve these goals, TiO2-NPs effects on cytotoxicity, genotoxicity, DNA repair activity and DNA repair gene expression were investigated in both cell lines upon exposure to 1-100 µg/mL of anatase/rutile, 21 nm TiO2-NPs. Our results show that TiO2-NPs induce comparable cytotoxic and genotoxic responses in BEAS-2B and A549 cells. Functional response to DNA damage is observed in both cell lines and consists of an overall downregulation in DNA repair processes. When evaluating the relative importance of the two DNA repair pathways, we observed a lower impact on BER compared with NER activities, suggesting that repair of oxidatively generated DNA damage is still triggered in these cells. This response becomes measureable at 4 h of exposure in BEAS-2B but only after 48 h of exposure in A549 cells. The delayed response in A549 cells is due to an initial overall and intense downregulation of the genes encoding DNA repair proteins. This overall downregulation correlates with increased methylation of DNA repair gene promoters and downregulation of NRF2 and BRCA1, which may thus be considered as upstream regulators. These results strengthen the evidence that TiO2-NP induces indirect genotoxicity in lung cells, via modulation of DNA repair processes, and shed some light on the mechanisms behind this effect.


Subject(s)
DNA Methylation , DNA Repair Enzymes/drug effects , DNA Repair/drug effects , Metal Nanoparticles/toxicity , Titanium/toxicity , A549 Cells , Cell Line , DNA/drug effects , DNA/metabolism , DNA Damage , DNA Repair/genetics , DNA Repair Enzymes/genetics , Down-Regulation , Humans , Lung/drug effects , Lung/metabolism , Metal Nanoparticles/chemistry , Mutagenicity Tests , Oxidative Stress , Promoter Regions, Genetic
8.
Nanoscale ; 8(38): 17012-17021, 2016 Sep 29.
Article in English | MEDLINE | ID: mdl-27722394

ABSTRACT

Silver nanoparticles (AgNPs) can enter eukaryotic cells and exert toxic effects, most probably as a consequence of the release of Ag+ ions. Due to the elusive nature of Ag+ ionic species, quantitative information concerning AgNP intracellular dissolution is missing. By using a synchrotron nanoprobe, silver is visualized and quantified in hepatocytes (HepG2) exposed to AgNPs; the synergistic use of electron microscopy allows for the discrimination between nanoparticular and ionic forms of silver within a single cell. AgNPs are located in endocytosis vesicles, while the visualized Ag+ ions diffuse in the cell. The averaged NP dissolution rates, measured by X-ray absorption spectroscopy, highlight the faster dissolution of citrate-coated AgNPs with respect to the less toxic PVP-coated AgNPs; these results are confirmed at the single-cell level. The released Ag+ ions recombine with thiol-bearing biomolecules: the Ag-S distances measured in cellulo, and the quantitative evaluation of gene expression, provide independent evidence of the involvement of glutathione and metallothioneins in Ag+ binding. The combined use of cutting-edge imaging techniques, atomic spectroscopy and molecular biology brings insight into the fate of AgNPs in hepatocytes, and more generally into the physicochemical transformations of metallic nanoparticles in biological environments and the resulting disruption of metal homeostasis.


Subject(s)
Hepatocytes/metabolism , Metal Nanoparticles , Silver/analysis , Citrates , Hep G2 Cells , Humans , Ions
9.
Nanoscale ; 7(16): 7323-30, 2015 Apr 28.
Article in English | MEDLINE | ID: mdl-25824974

ABSTRACT

Silver nanoparticle (AgNP) toxicity is related to their dissolution in biological environments and to the binding of the released Ag(+) ions in cellulo; the chemical environment of recombined Ag(+) ions is responsible for their toxicological outcome, moreover it is indicative of the cellular response to AgNP exposure, and can therefore shed light on the mechanisms governing AgNP toxicity. This study probes the chemistry of Ag species in primary murine macrophages exposed to AgNPs by making use of X-ray Absorption Fine Structure spectroscopy under cryogenic conditions: the linear combination analysis of the near-edge region of the spectra provides the fraction of Ag(+) ions released from the AgNPs under a given exposure condition and highlights their complexation with thiolate groups; the ab initio modelling of the extended spectra allows measuring the Ag-S bond length in cellulo. Dissolution rates depend on the exposure scenario, chronicity leading to higher Ag(+) release than acute exposure; Ag-S bond lengths are 2.41 ± 0.03 Å and 2.38 ± 0.01 Å in acute and chronic exposure respectively, compatible with digonal AgS2 coordination. Glutathione is identified as the most likely putative ligand for Ag(+). The proposed method offers a scope for the investigation of metallic nanoparticle dissolution and recombination in cellular models.


Subject(s)
Metal Nanoparticles/chemistry , Silver Compounds/chemistry , Silver/chemistry , Animals , Cell Survival/drug effects , Cells, Cultured , Glutathione/chemistry , Macrophages/cytology , Macrophages/drug effects , Macrophages/metabolism , Metal Nanoparticles/toxicity , Mice , Microscopy, Electron, Transmission , X-Ray Absorption Spectroscopy
10.
Nanoscale ; 7(16): 7352-60, 2015 Apr 28.
Article in English | MEDLINE | ID: mdl-25825056

ABSTRACT

TiO2 microparticles are widely used in food products, where they are added as a white food colouring agent. This food additive contains a significant amount of nanoscale particles; still the impact of TiO2 nanoparticles (TiO2-NPs) on gut cells is poorly documented. Our study aimed at evaluating the impact of rutile and anatase TiO2-NPs on the main functions of enterocytes, i.e. nutrient absorption driven by solute-liquid carriers (SLC transporters) and protection against other xenobiotics driven by efflux pumps from the ATP-binding cassette (ABC) family. We show that acute exposure of Caco-2 cells to both anatase (12 nm) and rutile (20 nm) TiO2-NPs induce early upregulation of a battery of efflux pumps and nutrient transporters. In addition they cause overproduction of reactive oxygen species and misbalance redox repair systems, without inducing cell mortality or DNA damage. Taken together, these data suggest that TiO2-NPs may increase the functionality of gut epithelial cells, particularly their property to form a protective barrier against exogenous toxicants and to absorb nutrients.


Subject(s)
Metal Nanoparticles/chemistry , Titanium/chemistry , Caco-2 Cells , Cell Survival/drug effects , Epithelial Cells/cytology , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Glucose Transporter Type 1/metabolism , Glucose Transporter Type 4/metabolism , Humans , Intestines/cytology , Metal Nanoparticles/toxicity , Reactive Oxygen Species/metabolism
11.
Mucosal Immunol ; 8(1): 127-40, 2015 Jan.
Article in English | MEDLINE | ID: mdl-24985081

ABSTRACT

Massive loss of lamina propria CD4(+) T cells, changes in the lymphatic architecture, and altered intestinal epithelial barrier leading to microbial translocation are the common features of HIV-1 infection and are not fully restored under combined antiretroviral therapy (cART). To better understand determinants of gut mucosal restoration, we have performed phenotypic and gene expression analyses of the gut from HIV-infected patients, naive or treated with cART initiated either at the early phase of the primary infection or later during the chronic phase. We found a depletion of T helper type 22 (Th22) and interleukin-17-producing cells in naive patients. These populations, except Th22 cells, were not restored under cART. Regulatory T cells/Th17 ratio was significantly increased in HIV-infected patients and was inversely correlated to the restoration of CD4(+) T cells but not to gut HIV DNA levels. Gene profile analysis of gut mucosal distinguished two groups of patients, which fitted with the timing of cART initiation. In their majority early, but not later treated patients, exhibited conserved intestinal lymphoid structure, epithelial barrier integrity and dendritic cell maturation pathways. Our data demonstrate that early initiation of cART helps to preserve and/or restore lymphoid gut mucosal homeostasis and provide a rationale for initiating cART during the acute phase of HIV infection.


Subject(s)
Anti-Retroviral Agents/therapeutic use , Dendritic Cells/drug effects , HIV Infections/drug therapy , HIV-1/drug effects , Intestines/drug effects , T-Lymphocytes, Regulatory/drug effects , Th17 Cells/drug effects , Cell Differentiation/drug effects , Cells, Cultured , DNA, Viral/blood , Dendritic Cells/immunology , Dendritic Cells/virology , Disease Progression , Drug Therapy, Combination , Female , Gene Expression Profiling , HIV Infections/immunology , HIV-1/physiology , Humans , Immunity, Mucosal/drug effects , Interleukins/metabolism , Intestines/immunology , Intestines/virology , Male , Middle Aged , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/virology , Th17 Cells/immunology , Th17 Cells/virology , Treatment Outcome , Interleukin-22
12.
Child Care Health Dev ; 40(6): 825-32, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24028505

ABSTRACT

CONTEXT: In 2003, Quebec's Ministry of Health and Social Services (MSSS) and the Ministry of Education, Recreation and Sports (MELS) concluded the Agreement for the complementarity of services between the health and social services network and the education network. The objectives of the current investigation were to evaluate the implementation of this Agreement and its impact upon renewal of practices and services, and to investigate the consequences for children with special needs and their families. The specific focus of this article is to describe parents' perspectives regarding the impact of this Agreement upon them and their children. METHODS: Interviews were conducted with 56 parents of children with disabilities, social maladjustment or learning difficulties across the province of Quebec. Data were analysed using content analysis. RESULTS: Most parents were not directly aware of any contact between school staff and health or social professionals, although discussions might have been held without their knowledge. The intervention plans seemed to be the main vehicle through which some parents perceived collaboration to be occurring. For parents, the impact upon actual practices or collaborative work is either minimal or non-existent. CONCLUSION: School inclusion of children with special needs is a challenge for all societies. The Agreement illustrates the Quebec government's intent to promote an alliance between two complex networks and has the potential to greatly benefit children and their families. However, more concrete action is required in order to realize specific changes regarding work cohesion and service organization for these groups.


Subject(s)
Child Health Services , Disabled Children/psychology , Learning Disabilities/psychology , Parents , Social Isolation/psychology , Social Support , Access to Information , Adolescent , Adult , Attitude of Health Personnel , Child , Child Health Services/organization & administration , Child, Preschool , Cooperative Behavior , Delivery of Health Care , Disabled Children/statistics & numerical data , Education, Special , Female , Health Services Accessibility/organization & administration , Humans , Learning Disabilities/epidemiology , Male , Parents/education , Parents/psychology , Patient Care Team/organization & administration , Patient Satisfaction , Professional-Family Relations , Quebec/epidemiology , Schools/organization & administration , Social Work/organization & administration , Surveys and Questionnaires
13.
J Biomed Nanotechnol ; 7(1): 22-3, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21485783

ABSTRACT

Titania nanoparticles are produced by tons, and included in commercial products, raising concerns about their potential impact on human health. This study relates their cytotoxic and genotoxic impact on a cell line representative of human lung, namely A549 alveolar epithelial cells.


Subject(s)
Lung Neoplasms/physiopathology , Metal Nanoparticles/toxicity , Mutagenicity Tests/methods , Toxicity Tests, Acute/methods , Cell Line, Tumor , Cell Survival/drug effects , Cytotoxins/toxicity , Dose-Response Relationship, Drug , Humans , Mutagens/toxicity , Titanium/toxicity
14.
Br Poult Sci ; 52(6): 792-9, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22221246

ABSTRACT

1.The objectives were to quantify the presence of neurogenic inflammation in 4 regions of the upper digestive tract of anaesthetised ducks (post-pharynx, pseudo-crop, transition between the pseudo-crop and the proventriculus, and proventriculus) after application of HCl stimulation of up to 4 M in the pseudo-crop. 2.The second objective was to quantify the presence of neurogenic inflammation in the same digestive tract regions as mentioned above during 4 feeding periods of foie gras production (rearing, preparation to force-feeding, and second and last meals of the force-feeding period). 3. Extravasation increased above a HCl stimulation threshold of 2 M. Furthermore, more extravasation was observed in the proventriculus compared to the other regions (P < 0·001). 4.Highest extravasation responses were observed in the proventriculus and the pseudo-crop at the end of the preparation period, and in the proventriculus after the second forced meal, compared with the rearing period (P < 0·01), with a return to rearing level at the end of force-feeding. 5.Such a kinetic could be indicative of a relative mildness of the irritant components associated with this feeding practice.


Subject(s)
Ducks/immunology , Enteral Nutrition/adverse effects , Hydrochloric Acid/pharmacology , Neurogenic Inflammation/veterinary , Proventriculus/immunology , Animal Welfare , Animals , Male , Random Allocation
15.
Toxicol Lett ; 198(3): 324-30, 2010 Oct 20.
Article in English | MEDLINE | ID: mdl-20655996

ABSTRACT

Silicon carbide (SiC) is considered a highly biocompatible material, consequently SiC nanoparticles (NPs) have been proposed for potential applications in diverse areas of technology. Since no toxicological data are available for these NPs, the aim of this study was to draw their global toxicological profile on A549 lung epithelial cells, using a battery of classical in vitro assays. Five SiC-NPs, with varying diameters and Si/C ratios were used, and we show that these SiC-NPs are internalized in cells where they cause a significant, though limited, cytotoxic effect. Cell redox status is deeply disturbed: SiC-NP exposure cause reactive oxygen species production, glutathione depletion and inactivation of some antioxidant enzymes: glutathione reductase, superoxide dismutase, but not catalase. Finally, the alkaline comet assay shows that SiC-NPs are genotoxic. Taken together, these data prove that SiC-NPs biocompatibility should be revisited.


Subject(s)
Carbon Compounds, Inorganic/toxicity , Lung/drug effects , Nanoparticles/toxicity , Oxidative Stress , Silicon Compounds/toxicity , Catalase/analysis , Catalase/metabolism , Cell Line, Tumor , Comet Assay , DNA Damage/drug effects , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Formazans/chemistry , Glutathione/analysis , Glutathione/metabolism , Glutathione Reductase/analysis , Glutathione Reductase/metabolism , Humans , Lung/cytology , Lung/metabolism , Microscopy, Electron, Transmission , Mutagenicity Tests , Nanoparticles/ultrastructure , Reactive Oxygen Species/analysis , Reactive Oxygen Species/metabolism , Statistics, Nonparametric , Superoxide Dismutase/analysis , Superoxide Dismutase/metabolism , Tetrazolium Salts/chemistry
16.
Toxicology ; 253(1-3): 137-46, 2008 Nov 20.
Article in English | MEDLINE | ID: mdl-18835419

ABSTRACT

If released in the environment, nanomaterials might be inhaled by populations and cause damage to the deepest regions of the respiratory tract, i.e., the alveolar compartment. To model this situation, we studied the response of A549 human pneumocytes after exposure to aluminium oxide or titanium oxide nanoparticles, and to multi-walled carbon nanotubes. The influence of size, crystalline structure and chemical composition was investigated. After a detailed identification of nanomaterial physico-chemical characteristics, cells were exposed in vitro and viability and intracellular accumulation were assessed. In our conditions, carbon nanotubes were more toxic than metal oxide nanoparticles. Our results confirmed that both nanotubes and nanoparticles are able to rapidly enter into cells, and distribute in the cytoplasm and intracellular vesicles. Among nanoparticles, we demonstrate significant difference in biological response as a function of size, crystalline phase and chemical composition. Their toxicity was globally lower than nanotubes toxicity. Among nanotubes, the length did not influence cytotoxicity, neither the presence of metal catalyst impurities.


Subject(s)
Cytoplasm/drug effects , Lung/drug effects , Metal Nanoparticles/toxicity , Nanotubes, Carbon/toxicity , Respiratory Mucosa/drug effects , Aluminum Oxide/toxicity , Apoptosis/drug effects , Cell Line, Tumor , Cytoplasm/ultrastructure , Epithelial Cells/chemistry , Epithelial Cells/drug effects , Epithelial Cells/ultrastructure , Humans , Lung/chemistry , Lung/ultrastructure , Metal Nanoparticles/analysis , Metal Nanoparticles/chemistry , Microscopy, Electron, Transmission , Nanotubes, Carbon/analysis , Nanotubes, Carbon/chemistry , Respiratory Mucosa/chemistry , Respiratory Mucosa/cytology , Respiratory Mucosa/ultrastructure , Titanium/toxicity
17.
Toxicology ; 252(1-3): 26-32, 2008 Oct 30.
Article in English | MEDLINE | ID: mdl-18708117

ABSTRACT

Uranium (U) and lead (Pb) are accumulated and fixed for long periods in bone, impairing remodeling processes. Their toxicity to osteoblasts, the cells responsible for bone formation, is poorly documented. It has been previously shown that cytotoxicity and phenotypic effects of both metals on osteoblasts are highly influenced by metal speciation. Differences in sensitivity between cell types have been underlined as well. In this paper, cellular accumulation of U and Pb in cultured and primary osteoblastic cells was assessed by trace element analysis. Distribution of different species at the cell scale was investigated by electron microscopy. Internalization of both metals was shown to be correlated to cytotoxicity and population growth recovery after exposure. For each metal, the amount of metal uptake leading to 50% cell death was shown to be speciation-dependent. Scanning and transmission electron microscopy showed the formation of precipitates with phosphate in lysosomes for both metals, whose role in toxicity or cell defence remains to be clarified. Although a clear link was established between cytotoxicity and accumulation, differences in sensitivity observed in terms of speciation could not be fully explained and other studies seem necessary.


Subject(s)
Lead/chemistry , Lead/metabolism , Osteoblasts/metabolism , Uranium/chemistry , Uranium/metabolism , Animals , Bone Neoplasms/metabolism , Bone Neoplasms/ultrastructure , Cell Line, Tumor , Computer Simulation , Dose-Response Relationship, Drug , Humans , Mass Spectrometry , Microscopy, Electron, Scanning Transmission , Osteoblasts/ultrastructure , Osteosarcoma/metabolism , Osteosarcoma/ultrastructure , Rats
18.
Toxicology ; 250(1): 62-9, 2008 Aug 19.
Article in English | MEDLINE | ID: mdl-18606205

ABSTRACT

Bone is one of the main retention organs for uranium (U) and lead (Pb). The clinical effects of U or Pb poisoning are well known: acute and chronic intoxications impair bone formation. However, only few studies dealt with the cellular and molecular mechanisms of their toxicity. The purpose of this study was to investigate acute cytotoxicity of U and Pb and their phenotypic effects on rat and human osteoblasts, the cells responsible for bone formation. The most likely species of the toxicants in contact with cells after blood contamination were selected for cell exposure. Results showed that the cytotoxic effect of U and Pb is highly dependent on their speciation. Thus, Pb was cytotoxic when left free in the exposure medium or when complexed with carbonate, cysteine or citrate, but not when complexed with albumin or phosphate, under an insoluble form. U was cytotoxic whatever its speciation, but differences in sensitivity were observed as a function of speciation. Population growth recovery could be obtained after exposure to low doses of U or Pb, except for some U-carbonate complexes which had irreversible effects whatever the dose. The activation of two markers of bone formation and mineralization, osteocalcin and bone sialoprotein (BSP), was observed after exposure to non-toxic doses or non-toxic species of U or Pb while their inhibition was observed after toxic exposure to both metals. This work provides new elements to better understand the complex mechanisms of U and Pb toxicity to osteoblasts. Our results also illustrate the importance of a strictly controlled speciation of the metals in toxicological studies.


Subject(s)
Lead/toxicity , Osteoblasts/drug effects , Osteogenesis/drug effects , Phenotype , Uranium Compounds/toxicity , Animals , Calcification, Physiologic/drug effects , Cell Line , Cell Line, Tumor , Humans , Lead/chemistry , Osteoblasts/metabolism , Osteocalcin/drug effects , Osteocalcin/metabolism , Rats , Sialoglycoproteins/drug effects , Sialoglycoproteins/metabolism , Uranium Compounds/chemistry
19.
Biochimie ; 88(11): 1605-18, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16996675

ABSTRACT

In case of accidental release of radionuclides into the environment, actinides represent a severe health risk to human beings following internal contamination (inhalation, ingestion or wound). For a better understanding of the actinide behaviour in man (in term of metabolism, retention, excretion) and in specific biological systems (organs, cells or biochemical pathways), it is of prime importance to have a good knowledge of the relevant actinide solution chemistry and biochemistry, in particular of the thermodynamic constants needed for computing actinide speciation. To a large extent, speciation governs bioavailability and toxicity of elements and has a significant impact on the mechanisms by which toxics accumulate in cell compartments and organs and by which elements are transferred and transported from cell to cell. From another viewpoint, speciation is the prerequisite for the design and success of potential decorporation therapies. The purpose of this review is to present the state of the art of actinide knowledge within biological media. It is also to discuss how actinide speciation can be determined or predicted and to highlight the areas where information is lacking with the aim to encourage new research efforts.


Subject(s)
Actinoid Series Elements/classification , Actinoid Series Elements/analysis , Actinoid Series Elements/pharmacology , Actinoid Series Elements/toxicity , Environmental Pollution , Humans , Radioisotopes/toxicity , Thermodynamics
20.
J Viral Hepat ; 13(9): 633-42, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16907851

ABSTRACT

Alcohol consumption has a major impact on the natural history of chronic hepatitis C virus (HCV) infection, although the underlying mechanisms are still debated. We designed a clinical study to evaluate the impact of alcohol abuse on both viral load and expression of low-density lipoprotein receptor (LDLR) and CD81 expression. Thirty-eight consecutive HCV-infected patients were enrolled. Group 1 (n = 18), < or =10 g alcohol/day, group 2 (n = 8), < or =30 g alcohol/day, group 3 (n = 12), >or =30 g alcohol/day. Receptors expression was measured by flow cytometry analysis in peripheral blood mononuclear cells (PBMC) and by specific real-time retrotranscription polymerase chain reaction (RT-PCR) in the liver. Serum viral load was evaluated by quantification of both HCV genomic RNA and total core antigen. The hepatic viral load was assessed by real-time RT-PCR. Serum HCV-RNA and total core antigen were significantly correlated, and were higher, albeit not significantly, in group 3 than in group 1. Alcohol consumption had no effect on expression of HCV putative receptors in PBMC, except for CD81, which was upregulated on monocytes in group 2. In the liver, viral load and levels of LDLR transcripts were significantly higher in group 3 than in group 1. Remarkably, a significant positive correlation was found between LDLR transcripts and HCV-RNA (r2 = 0.83, P < 10(-3)). Finally, in vitro experiments suggested that the effect of ethanol on LDLR expression was indirectly mediated by both tumour necrosis factor-alpha and interleukin-1beta. In conclusion, this study is the first to support a role for LDLR in the natural infection by HCV in man.


Subject(s)
Alcohol Drinking , Hepacivirus/physiology , Hepatitis C, Chronic/metabolism , Hepatitis C, Chronic/virology , Liver/virology , RNA, Viral/analysis , Receptors, LDL/genetics , Adult , Antigens, CD/biosynthesis , Antigens, CD/genetics , Flow Cytometry , Gene Expression Profiling , Hepacivirus/genetics , Hepacivirus/isolation & purification , Hepatitis C, Chronic/genetics , Humans , Leukocytes, Mononuclear/chemistry , Liver/metabolism , Male , Middle Aged , RNA, Viral/blood , Receptors, LDL/biosynthesis , Receptors, Virus/genetics , Receptors, Virus/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Statistics as Topic , Tetraspanin 28 , Transcription, Genetic , Viral Load
SELECTION OF CITATIONS
SEARCH DETAIL
...